| 1. |
- Abel, Edvard, 1970, et al.
(författare)
-
Fatigue in Patients With Head and Neck Cancer Treated With Radiation Therapy: A Prospective Study of Patient-Reported Outcomes and Their Association With Radiation Dose to the Cerebellum
- 2022
-
Ingår i: Advances in Radiation Oncology. - : Elsevier BV. - 2452-1094. ; 7:5
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Although fatigue is a known side effect in patients with head and neck cancer (HNC) receiving radiation therapy, knowledge regarding long-term fatigue and dose-response relationships to organs at risk is scarce. The aim of this prospective study was to analyze patient-reported fatigue in patients with HNC receiving radiation therapy and to explore any possible association with organ-at-risk doses. Methods and Materials: Patients with HNC referred for curative radiation therapy were eligible for inclusion in the study. To assess patient-reported fatigue, quality of life questionnaires (European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-FA12) were distributed before treatment and 1, 3, 6, 12, 24, and 60 months after the start of treatment. Mean dose (Dmean) and near maximum dose (D2%) of the cerebellum and brain stem were evaluated in relation to baseline-adjusted fatigue scores at 3 months. Results: One hundred twenty-six patients treated with intensity modulated radiation therapy between 2008 and 2010 were available for final analysis. Female sex and age <60 years were associated with higher fatigue at baseline, whereas patients also treated with chemotherapy had reduced physical and emotional fatigue at 6 months. Physical fatigue (QLQ-FA12 scale) increased from baseline up to 3 months (29 vs 59; P < .0001) but showed no difference compared with baseline from 1 to 5 years. Emotional fatigue was significantly lower at 5 years compared with baseline (14 vs 28; P < .0001). Patients with cerebellum Dmean > 3.5 Gy had higher mean physical fatigue scores at 3 months (38 vs 27; P = .036). Conclusions: Although there is a significant increase in fatigue scores for patients with HNC up to 1 year after radiation therapy, this study showed a return to baseline levels at 5 years. A possible association was found between physical fatigue and a higher mean dose to the cerebellum.
|
|
| 2. |
|
|
| 3. |
- Jernås, Margareta, 1961, et al.
(författare)
-
MS risk genes are transcriptionally regulated in CSF leukocytes at relapse
- 2013
-
Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 19:4, s. 403-410
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Infiltrating T-helper cells, cytotoxic T-cells, B-cells and monocytes are thought to mediate the damage to myelin, oligodendrocytes and axons in multiple sclerosis (MS), which results in progressive disability. OBJECTIVE: The objective of this paper is to explore gene expression profiles of leukocytes in the cerebrospinal fluid (CSF) compartment of MS patients during relapse. METHODS: Global gene expression was analyzed by DNA microarray analysis of cells in CSF from MS patients and controls, and verifications were performed with real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). RESULTS: Fifty percent of the recently described risk genes for MS and 28% of non-risk genes were differently expressed in MS patients compared to controls (χ(2)-test, p=7.7 × 10(-5)). Genes involved in T- and NK-cell processes were up-regulated, and genes involved in processes targeting innate immunity or B-cells were down-regulated in MS. Increased expression of EDN1 and CXCL11 and decreased expression of HMOX1 was verified with real-time PCR and increased expression of CXCL13 was verified with ELISA in CSF. CONCLUSION: DNA microarray analysis is useful in identifying differently expressed genes in CSF leukocytes, which may be important in MS in vivo. Our findings suggest that many of the risk genes for MS are differently expressed in the disease-mediating leukocytes that penetrate the blood-brain barrier.
|
|
| 4. |
|
|
| 5. |
- Mårild, Karl, 1982, et al.
(författare)
-
Histologic activity in inflammatory bowel disease and risk of serious infections : A nationwide study
- 2024
-
Ingår i: Clinical Gastroenterology and Hepatology. - : Elsevier. - 1542-3565 .- 1542-7714. ; 22:4, s. 831-846
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Individuals with inflammatory bowel disease (IBD) are at increased risk of serious infections, but whether this risk varies by histological disease activity is unclear.METHODS: A national population-based study of 55,626 individuals diagnosed with IBD in 1990-2016 with longitudinal data on ileo-colorectal biopsies followed through 2016. Serious infections were defined as having an inpatient infectious disease diagnosis in the Swedish National Patient Register. We used Cox regression to estimate hazard ratios (HRs) for serious infections in the 12 months following documentation of histologic inflammation (vs. histological remission), adjusting for social and demographic factors, chronic comorbidities, prior IBD-related surgery and hospitalization. We also adjusted for IBD-related medications in sensitivity analyses.RESULTS: With histological inflammation vs. remission, there was 4.62 (95%CI=4.46-4.78) and 2.53 (95%CI=2.36-2.70) serious infections per 100 person-years of follow-up, respectively (adjusted [a]HR=1.59; 95%CI=1.48-1.72). Histological inflammation (vs. remission) were associated with an increased risk of serious infections in ulcerative colitis (UC, aHR=1.68; 95%CI=1.51-1.87) and Crohn's disease (CD, aHR=1.59; 95%CI=1.40-1.80). The aHRs of sepsis and opportunistic infections were 1.66 (95%CI=1.28-2.15) and 1.71 (95%CI=1.22-2.41), respectively. Overall, results were consistent across age groups, sex and education level and remained largely unchanged after adjustment for IBD-related medications (aHR=1.47; 95%CI=1.34-1.61).CONCLUSION: Histological inflammation of IBD was an independent risk factor of serious infections, including sepsis, suggesting that achieving histological remission may reduce infections in IBD.
|
|
| 6. |
- Olsson, Bob, 1969, et al.
(författare)
-
CSF and blood biomarkers for the diagnosis of Alzheimer's disease: a systematic review and meta-analysis.
- 2016
-
Ingår i: The Lancet. Neurology. - 1474-4465. ; 15:7, s. 673-684
-
Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease biomarkers are important for early diagnosis in routine clinical practice and research. Three core CSF biomarkers for the diagnosis of Alzheimer's disease (Aβ42, T-tau, and P-tau) have been assessed in numerous studies, and several other Alzheimer's disease markers are emerging in the literature. However, there have been no comprehensive meta-analyses of their diagnostic performance. We systematically reviewed the literature for 15 biomarkers in both CSF and blood to assess which of these were most altered in Alzheimer's disease.
|
|
| 7. |
- Olsson, Caroline, 1970, et al.
(författare)
-
Initial experience with introducing national guidelines for CT- and MRI-based delineation of organs at risk in radiotherapy
- 2019
-
Ingår i: Physics and Imaging in Radiation Oncology. - : Elsevier. - 2405-6316. ; 11, s. 88-91
-
Tidskriftsartikel (refereegranskat)abstract
- A fundamental problem in radiotherapy is the variation of organ at risk (OAR) volumes. Here we present our initial experience in engaging a large Radiation Oncology (RO) community to agree on national guidelines for OAR delineations. Our project builds on associated standardization initiatives and invites professionals from all radiotherapy departments nationwide. Presently, one guideline (rectum) has successfully been agreed on by a majority vote. Reaching out to all relevant parties in a timely manner and motivating funding agencies to support the work represented early challenges. Population-based data and a scalable methodological approach are major strengths of the proposed strategy.
|
|
| 8. |
|
|
| 9. |
- Shungin, Dmitry, et al.
(författare)
-
New genetic loci link adipose and insulin biology to body fat distribution.
- 2015
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 187-378
-
Tidskriftsartikel (refereegranskat)abstract
- Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.
|
|
| 10. |
- Alevronta, Eleftheria, et al.
(författare)
-
Dose-response relationships for an atomized symptom of fecal incontinence after gynecological radiotherapy.
- 2013
-
Ingår i: Acta oncologica (Stockholm, Sweden). - : Taylor & Francis. - 1651-226X .- 0284-186X. ; 52:4, s. 719-26
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose. The aim of this study was to investigate what bowel organ and delivered dose levels are most relevant for the development of 'emptying of all stools into clothing without forewarning' so that the related dose-responses could be derived as an aid in avoiding this distressing symptom in the future. Material and methods. Of the 77 gynecological cancer survivors treated with radiotherapy (RT) for gynecological cancer, 13 developed the symptom. The survivors were treated between 1991 and 2003. The anal-sphincter region, the rectum, the sigmoid and the small intestines were all delineated and the dose-volume histograms were exported for each patient. The dose-volume parameters were estimated fitting the data to the Relative Seriality (RS), the Lyman and the generalized Equivalent Uniform Dose (gEUD) model. Results. The dose-response parameters for all three models and four organs at risk (OARs) were estimated. The data from the sigmoid fits the studied models best: D50 was 58.8 and 59.5 Gy (RS, Lyman), γ50 was 1.60 and 1.57 (RS, Lyman), s was 0.32, n was 0.13 and a was 7.7 (RS, Lyman, gEUD). The estimated volume parameters indicate that the investigated OARs behave serially for this endpoint. Our results for the three models studied indicate that they have the same predictive power (similar LL values) for the symptom as a function of the dose for all investigated OARs. Conclusions. In our study, the anal-sphincter region and sigmoid fit our data best, but all OARs were found to have steep dose-responses for 'emptying of all stools into clothing without forewarning' and thus, the outcome can be predicted with an NTCP model. In addition, the dose to the four studied OARs may be considered when minimizing the risk of the symptom.
|
|
| 11. |
|
|
| 12. |
- Alsadius, David, 1975, et al.
(författare)
-
Partnership status affects the association between gastrointestinal symptoms and quality of life after radiation therapy for prostate cancer.
- 2014
-
Ingår i: Acta oncologica (Stockholm, Sweden). - 1651-226X. ; 53:3, s. 378-384
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose. To study if partnership modifies the effect of gastrointestinal symptoms on quality of life after radiation therapy for prostate cancer. Material and methods. Using a study-specific questionnaire we conducted a cross-sectional follow-up of the occurrence gastrointestinal symptoms and quality of life after radiation therapy for prostate cancer. We obtained information from 874 prostate cancer survivors treated with radiation therapy at the Sahlgrenska University Hospital, Sweden between 1994 and 2006. In this paper we describe how partnership status affects the association between gastrointestinal symptoms and quality of life. Results. We found that unpartnered men with gastrointestinal symptoms reported a lower quality of life than unpartnered men without such symptoms. Unpartnered men with symptoms had an excess risk of low quality of life compared with unpartnered men without symptoms for those experiencing altered composition of stools, prevalence ratio 3.8 (95% CI 1.1-13.1), leakage, 3.6 (1.3-10.1), sensory bowel symptoms, 4.5 (1.6-12.8), and for urgency, 4.2 (1.2-15.1). We also found that unpartnered men with symptoms had an excess risk of low quality of life compared with partnered men with symptoms for those experiencing altered composition of stools, prevalence ratio 2.9 (95% CI 1.4-5.8), leakage 2.8 (1.2-6.4), sensory bowel symptoms 3.4 (1.5-7.4), urgency 2.6 (1.2-5.8), and for any gastrointestinal symptom 2.5 (1.3-4.9). Conclusion. Unpartnered men may represent a group that is specifically vulnerable to the distressful effects of gastrointestinal symptoms after radiation therapy for prostate cancer.
|
|
| 13. |
- Alsadius, David, 1975, et al.
(författare)
-
Patient-reported gastrointestinal symptoms among long-term survivors after radiation therapy for prostate cancer.
- 2014
-
Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 1879-0887. ; 112:2, s. 237-243
-
Tidskriftsartikel (refereegranskat)abstract
- With modern radiotherapy technology we have the means to substantially reduce late gastrointestinal toxicities after radiation therapy for prostate cancer. However, there is still a lack of knowledge regarding the spectrum of patient-reported gastrointestinal symptoms after such treatment.
|
|
| 14. |
- Alsadius, David, 1975, et al.
(författare)
-
Perception of body odor-an overlooked consequence of long-term gastrointestinal and urinary symptoms after radiation therapy for prostate cancer.
- 2013
-
Ingår i: Journal of cancer survivorship : research and practice. - : Springer Science and Business Media LLC. - 1932-2267. ; 7:4, s. 652-658
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose This study was conducted to investigate the association of long-term gastrointestinal and urinary symptoms with perceived fecal or urine body odor after radiation therapy for prostate cancer and its effect on survivors’ quality of life. Methods We used a study-specific questionnaire to measure the occurrence of long-term gastrointestinal and urinary symptoms, the perception of fecal or urine body odor, and quality of life (QoL) 2 to 14 years after radiation therapy for prostate cancer. The questionnaire was sent to 895 eligible survivors who assessed symptom occurrence and QoL in the previous 6 months. Results We received a filled-in questionnaire from 874 (89 %) men. For the long-term gastrointestinal symptoms, 11/13 were associated with the perception of fecal body odor. For the long-term urinary symptoms, 11/11 were associated with the perception of urine body odor. Men who perceived fecal or urine body odor had a lower quality of life, a lower physical health, and more frequent feelings of depression compared with those who did perceive such body odor. Conclusion Long-term gastrointestinal and urinary symptoms after prostate irradiation are associated with the perception of fecal or urine body odor leading to a reduced quality of life. Implications for cancer survivors Disabling body odor after pelvic irradiation needs to be acknowledged in the clinic. Interventions to prevent long-term symptoms may serve the benefit of avoiding fecal or urine body odor after radiation therapy for prostate cancer.
|
|
| 15. |
- Beasley, W., et al.
(författare)
-
Image-based Data Mining to Probe Dosimetric Correlates of Radiation-induced Trismus
- 2018
-
Ingår i: International Journal of Radiation Oncology Biology Physics. - : Elsevier BV. - 0360-3016. ; 102:4, s. 1330-1338
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To identify imaged regions in which dose is associated with radiation-induced trismus after head and neck cancer radiation therapy (HNRT) using a novel image-based data mining (IBDM) framework. Methods and Materials: A cohort of 86 HNRT patients were analyzed for region identification. Trismus was characterized as a continuous variable by the maximum incisor-to-incisor opening distance (MID) at 6 months after radiation therapy. Patient anatomies and dose distributions were spatially normalized to a common frame of reference using deformable image registration. IBDM was used to identify clusters of voxels associated with MID (P <= .05 based on permutation testing). The result was externally tested on a cohort of 35 patients with head and neck cancer. Internally, we also performed a dose-volume histogram-based analysis by comparing the magnitude of the correlation between MID and the mean dose for the IBDM-identified cluster in comparison with 5 delineated masticatory structures. Results: A single cluster was identified with the IBDM approach (P < .01), partially overlapping with the ipsilateral masseter. The dose-volume histogram-based analysis confirmed that the IBDM cluster had the strongest association with MID, followed by the ipsilateral masseter and the ipsilateral medial pterygoid (Spearman's rank correlation coefficients: R-s = -0.36, -0.35, -0.32; P = .001, .001, .002, respectively). External validation confirmed an association between mean dose to the IBDM cluster and MID (R-s = -0.45; P = .007). Conclusions: IBDM bypasses the common assumption that dose patterns within structures are unimportant. Our novel IBDM approach for continuous outcome variables successfully identified a cluster of voxels that are highly associated with trismus, overlapping partially with the ipsilateral masseter. Tests on an external validation cohort showed an even stronger correlation with trismus. These results support use of the region in HNRT treatment planning to potentially reduce trismus. (C) 2018 Elsevier Inc. All rights reserved.
|
|
| 16. |
- Chorell, Elin, 1981-, et al.
(författare)
-
Plasma metabolomic response to postmenopausal weight loss induced by different diets
- 2016
-
Ingår i: Metabolomics. - : Springer Science and Business Media LLC. - 1573-3882 .- 1573-3890. ; 12:5
-
Tidskriftsartikel (refereegranskat)abstract
- Background Menopause is associated with increased abdominal fat and increased risk of developing diabetes and cardiovascular disease. Objectives The present study evaluated the plasma metabolic response in relation to insulin sensitivity after weight loss via diet intervention. Methods This work includes two studies; i) Ten women on a 5 weeks Paleolithic-type diet (PD, 30 energy percent (E%) protein, 40 E% fat, 30 E% carbohydrates), ii) 55 women on 6 months of either PD or Nordic Nutrition Recommendations diet (NNR, 15 E% protein, 30 E% fat, and 55 E% carbohydrates). Plasma metabolic profiles were acquired at baseline and post diet using gas chromatography time-of-flight/mass spectrometry and investigated in relation to insulin sensitivity using multivariate bioinformatics. Results Both the PD and NNR diet resulted in significant weight loss, reduced waist circumference, improved serum lipid profiles, and improved insulin sensitivity. We detected a baseline metabolic profile that correlated significantly with insulin sensitivity, and of which components increased significantly in the PD group compared to NNR. Specifically, a significant increase in myo-inositol (MI), a second messenger of insulin action, and beta-hydroxybutyric acid (beta-HB)increased while dihomogamma-linoleic acid (DGLA) decreased in PD compared to NNR, which correlated with improved insulin sensitivity. We also detected a significant decrease in tyrosine and tryptophan, potential markers of insulin resistance when elevated in the circulation, with the PD but not the NNR. Conclusions Using metabolomics, we detected changes in the plasma metabolite profiles associated with weight loss in postmenopausal women by different diets. The metabolic profiles following 6 months of PD were linked to beneficial effects on insulin sensitivity compared to NNR.
|
|
| 17. |
- Gurjar, Mrugaja, 1997, et al.
(författare)
-
Automated data extraction tool (DET) for external applications in radiotherapy.
- 2023
-
Ingår i: Technical innovations & patient support in radiation oncology. - : Elsevier BV. - 2405-6324. ; 25
-
Tidskriftsartikel (refereegranskat)abstract
- Oncological Information Systems (OIS) manage information in radiotherapy (RT) departments. Due to database structure limitations, stored information can rarely be directly used except for vendor-specific purposes. Our aim is to enable the use of such data in various external applications by creating a tool for automatic data extraction, cleaning and formatting.We used OIS data from a nine-linac RT department in Sweden (70weeks, 2015-16). Extracted data included patients' referrals and appointments with details for RT sub-tasks. The data extraction tool to prepare the data for external use was built in C# programming language. It used excel-automation queries to remove unassigned/duplicated values, substitute missing data and perform application-specific calculations. Descriptive statistics were used to verify the output with the manually prepared dataset from the corresponding time period.From the initial raw data, 2030 (51%)/907 (23%) patients had known curative and palliative treatment intent for 84 different cancer diagnoses. After removal of incomplete entries, 373 (10%) patients had unknown treatment intents which were substituted based on the known curative/palliative ratio. Automatically- and manuallyprepared datasets differed<1% for Mould, Treatment planning, Quality assurance and±5% for Fractions and Magnetic resonance imaging with overestimations in 80/140 (57%) entries by the tool.We successfully implemented a software tool to prepare ready-to-use OIS datasets for external applications. Our evaluations showed overall results close to the manually-prepared dataset. The time taken to prepare the dataset using our automated strategy can reduce the time for manual preparation from weeks to seconds.
|
|
| 18. |
- Hedström, Anna, 1983, et al.
(författare)
-
Identifying organs at risk for radiation-induced late dysphagia in head and neck cancer patients.
- 2019
-
Ingår i: Clinical and translational radiation oncology. - : Elsevier BV. - 2405-6308. ; 19, s. 87-95
-
Tidskriftsartikel (refereegranskat)abstract
- Dysphagia is a common, severe and dose-limiting toxicity after oncological treatment of head and neck cancer (HNC). This study aims to investigate relationships between radiation doses to structures involved in normal swallowing and patient-reported as well as clinically measured swallowing function in HNC patients after curative (chemo-) radiation therapy (RT) with focus on late effects.Patients (n=90) with HNC curatively treated with RT±chemotherapy in 2007-2015 were assessed for dysphagia post-treatment by telephone interview and videofluoroscopy (VFS). A study-specific symptom score was used to determine patient-reported dysphagia. The Penetration-Aspiration Scale (PAS) was applied to determine swallowing function by VFS (PAS≥4/≥6=moderate/severe dysphagia). Thirteen anatomical structures involved in normal swallowing were individually delineated on the patients' original planning CT scans and associated dose-volume histograms (DVHs) retrieved. Relationships between structure doses and late toxicity were investigated through univariable and multivariable logistic regression analysis (UVA/MVA) accounting for effects by relevant clinical factors.Median assessment time was 7months post-RT (range: 5-34months). Mean dose to the contralateral parotid gland and supraglottic larynx as well as maximum dose to the contralateral anterior digastric muscle predicted patient-reported dysphagia (AUC=0.64-0.67). Mean dose to the pharyngeal constrictor muscle, the larynx, the supraglottic larynx and the epiglottis, as well as maximum dose to the contralateral submandibular gland predicted moderate and severe dysphagia by VFS (AUC=0.71-0.80).The patients in this cohort were consecutively identified pre-treatment, and were structurally approached and assessed for dysphagia after treatment at a specific time point. In addition to established dysphagia organs-at-risk (OARs), our data suggest that epiglottic and submandibular gland doses are important for swallowing function post-RT. Keeping DVH thresholds below V60=60% and V60=17%, respectively, may increase chances to reduce occurrence of severe late dysphagia. The results need to be externally validated in future studies.
|
|
| 19. |
- Hedström, Johanna, et al.
(författare)
-
Correlations Between Patient-Reported Dysphagia Screening and Penetration-Aspiration Scores in Head and Neck Cancer Patients Post-oncological Treatment.
- 2018
-
Ingår i: Dysphagia. - : Springer Science and Business Media LLC. - 1432-0460 .- 0179-051X. ; 33:2, s. 206-215
-
Tidskriftsartikel (refereegranskat)abstract
- Dysphagia is a common and severe toxicity after oncological treatment of head and neck cancer (HNC). The study aim was to investigate relationships between patient-reported dysphagia and clinically measured swallowing function in HNC after modern curative radiotherapy with or without chemotherapy to identify possible alarm symptoms for clinically manifest dysphagia. Patients with tumors of the tonsil, base of tongue, hypopharynx, and larynx treated in 2007-2015 were assessed for dysphagia post-treatment by telephone interview and videofluoroscopy (VFS). A study-specific categorized symptom score was used to determine patient-reported dysphagia (DESdC=presence of Drinking, Eating, Swallowing difficulties, and Coughing when eating/drinking (any combination); scores between 0 and 4 with 0=no symptom); the penetration-aspiration scale (PAS) to determine swallowing function by VFS. Swallowing difficulties were defined as DESdC≥1 and PAS≥2. Relationships between clinically relevant cut-offs for DESdC and PAS were determined by Pearson's correlation coefficient (Pr). Swallowing difficulties according to DESdC were reported by 89% of the patients and according to PAS by 60% at a median of 7months post-treatment. Averaged correlations between DESdC score 1/2/3/4 and PAS were 0.16/0.10/0.27/0.18. Almost one in two patients with DESdC score ≥3 had severe swallowing difficulties according to PAS. Correlations between individual DESdC:s were highest for swallowing and eating (Pr=0.53) and lowest for swallowing and coughing (Pr=0.11). Our data suggest that if a patient reports having swallowing difficulties, it is likely that he or she also has eating difficulties but not necessarily coughing problems when eating/drinking. However, if all these three symptoms are reported, it is likely that the patient will present with moderate or severe impaired swallowing function according to PAS and thus should be referred for further evaluation and treatment.
|
|
| 20. |
- Hedström, Johanna, et al.
(författare)
-
Quality of care in dysphagia patients: adaptation and validation of the Swedish SWAL-CARE questionnaire
- 2020
-
Ingår i: Health and Quality of Life Outcomes. - : Springer Science and Business Media LLC. - 1477-7525. ; 18:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background The aim of this study was to adapt the instrument and evaluate the psychometric properties of the Swedish version of the Swallowing Quality of Care questionnaire (S-SWAL-CARE) in patients with oropharyngeal dysphagia. Methods Translation and adaptation of the original SWAL-CARE into Swedish was performed according to established international guidelines. Field testing was performed using 100 patients with oropharyngeal dysphagia due to multiple reasons such as head and neck cancer and neurologic/neuromuscular disease, who had undergone swallowing evaluation within 6 months prior to the study. The patients answered the S-SWAL-CARE, the Quality from the Patient's Perspective (QPP) and the Swallowing Quality of Life (SWAL-QOL). Test-retest was performed in 20% of the participants. The reliability and validity of the S-SWAL-CARE were assessed by Pearson correlation coefficient and Cronbach's alpha as well as convergent and discriminative validity, respectively. Results The field testing of the S-SWAL-CARE resulted in sufficient reliability, with Cronbach's alpha values exceeding 0.90 for all domains. All items correlated strongly to their own domain, with weaker correlations to the other domains, indicating proper scale structure. Results also indicate sufficient convergent and discriminant validity when tested for association to the QPP domains and the SWAL-QOL Total score. The test-retest reliability of the S-SWAL-CARE demonstrated sufficient intraclass correlation coefficient (ICC) for the General advice domain (0.73) and Clinical advice domain (0.82). The ICC for the Patient satisfaction domain was lower (0.44). Conclusion The S-SWAL-CARE can be considered a reliable and valid tool to assess the dysphagia-related quality of care in a mixed Swedish dysphagia patient population.
|
|
| 21. |
- Holmström, Paul, et al.
(författare)
-
Insights Gained From a Re-analysis of Five Improvement Cases in Healthcare Integrating System Dynamics Into Action Research
- 2022
-
Ingår i: International Journal of Health Policy and Management. - 2322-5939. ; 11:11, s. 2707-2718
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Healthcare is complex with multi-professional staff and a variety of patient care pathways. Time pressure and minimal margins for errors, as well as tension between hierarchical power and the power of the professions, make it challenging to implement new policies or procedures. This paper explores five improvement cases in healthcare integrating system dynamics (SD) into action research (AR), aiming to identify methodological aspects of how this integration supported multi-professional groups to discover workable solutions to work-related challenges. Methods: This re-analysis was conducted by a multi-disciplinary research group using an iterative abductive approach applying qualitative analysis to structure and understand the empirical material. Frameworks for consultancy assignments/client projects were used to identify case project stages (workflow steps) and socio-analytical questions were used to bridge between the AR and SD perspectives. Results: All studied cases began with an extensive AR-inspired inventory of problems/objectives and ended with an SD- facilitated experimental phase where mutually agreed solutions were tested in silico. Time was primarily divided between facilitated group discussions during meetings and modelling work between meetings. Work principles ensured that the voice of each participant was heard, inspired engagement, interaction, and exploratory mutual learning activities. There was an overall pattern of two major divergent and convergent phases, as each group moved towards a mutually developed point of reference for their problem/objective and solution, a case-specific multi-professional knowledge repository. Conclusion: By integrating SD into AR, more favourable outcomes for the client organization may be achieved than when applying either approach in isolation. We found that SD provided a platform that facilitated experiential learning in the AR process. The identified results were calibrated to local needs and circumstances, and compared to traditional top-down implementation for change processes, improved the likelihood of sustained actualisation.
|
|
| 22. |
- Holmström, Paul, et al.
(författare)
-
Insights gained from a systematic reanalysis of a successful model-facilitated change process in health care
- 2021
-
Ingår i: Systems Research and Behavioral Science. - : Wiley. - 1092-7026 .- 1099-1743. ; 38:2, s. 204-214
-
Tidskriftsartikel (refereegranskat)abstract
- © 2020 The Authors. Systems Research and Behavioral Science published by International Federation for Systems Research and John Wiley & Sons Ltd Health care is a complex system with multiprofessional staff and multiple patient care pathways. Time pressure and minimal margins for error make it challenging to implement new policies or procedures, no matter how desirable. Changes in health care also requires the participation of the staff. System dynamics (SD) simulations can lead to shared systems understanding and allows for the development and testing of new scenarios in silico before implementing solutions. However, research shows that the actual implementation rate of simulations is low. This paper presents a reanalysis of a successful change project in health care combining SD principles with basic action research (AR) premises. The analysis was done by a multidisciplinary research group using qualitative methodology and identifies that a fruitful combination of AR inquiry and SD modelling potentially can improve implementation rates.
|
|
| 23. |
- Larsson, Torbjörn, et al.
(författare)
-
Convergent Lagrangian heuristics for nonlinear minimum cost network flows
- 2008
-
Ingår i: European Journal of Operational Research. - : Elsevier BV. - 0377-2217 .- 1872-6860. ; 189:2, s. 324-346
-
Tidskriftsartikel (refereegranskat)abstract
- We consider the separable nonlinear and strictly convex single-commodity network flow problem (SSCNFP). We develop a computational scheme for generating a primal feasible solution from any Lagrangian dual vector, this is referred to as "early primal recovery". It is motivated by the desire to obtain a primal feasible vector before convergence of a Lagrangian scheme, such a vector is not available from a Lagrangian dual vector unless it is optimal. The scheme is constructed such that if we apply it from a sequence of Lagrangian dual vectors that converge to an optimal one, then the resulting primal (feasible) vectors converge to the unique optimal primal flow vector. It is therefore also a convergent Lagrangian heuristic, akin to those primarily devised within the field of combinatorial optimization but with the contrasting and striking advantage that it is guaranteed to yield a primal optimal solution in the limit. Thereby we also gain access to a new stopping criterion for any Lagrangian dual algorithm for the problem, which is of interest in particular if the SSCNFP arises as a subproblem in a more complex model. We construct instances of convergent Lagrangian heuristics that are based on graph searches within the residual graph, and therefore are efficiently implementable, in particular we consider two shortest path based heuristics that are based on the optimality conditions of the original problem. Numerical experiments report on the relative efficiency and accuracy of the various schemes. © 2007 Elsevier B.V. All rights reserved.
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Lindberg, Jesper, 1983, et al.
(författare)
-
A national perspective about the current work situation at modern radiotherapy departments
- 2020
-
Ingår i: Clinical and Translational Radiation Oncology. - : Elsevier BV. - 2405-6308. ; 24, s. 127-134
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The radiotherapy (RT) community faces great challenges to meet the growing cancer incidence, especially regarding workload and recruitment of personnel. Workflow-related issues affect involved professions differently since they have specific expertise and various roles in the workflow. To obtain an objective understanding of the current working situation and identify workflow bottle necks in RT, we conducted a national survey on this topic in 2018. Materials and Methods: All 17 (photon-based) RT departments in Sweden were invited to participate in the study, which targeted both managers and employees in RT. Descriptive statistics were calculated for each profession and for small, medium and large departments (2/3–4/≥5 linacs). Results: Altogether, 364 filled-in questionnaires were returned (32/332 managers/employees; 94% response rate). Managers reported a general need for more staff (all professions). Small departments reported no problems with waiting times (0/3); whereas 2/3 of medium and large departments did (medium: 5/8, large: 2/3). All professions had a positive attitude towards working in RT (mean = 86%, 0/100%=negative/positive attitude). Organizational issues were ranked highest among reoccurring events that were most frustrating/had most negative effect on the work environment. The most severe workflow-related problems were reported to originate at contouring. Conclusion: Future efforts to improve the modern RT workflow need to focus on how to make positive mechanisms at small departments useful in larger settings. Our data also reveal that strong leadership and improved routines at contouring are warranted by all RT professions to reduce frustration related to organizational issues and to increase work effectivity.
|
|
| 27. |
- Lindberg, Jesper, 1983, et al.
(författare)
-
An analytical approach to aggregate patient inflows to a simulation model over the radiotherapy process.
- 2021
-
Ingår i: BMC health services research. - : Springer Science and Business Media LLC. - 1472-6963. ; 21
-
Tidskriftsartikel (refereegranskat)abstract
- In meeting input data requirements for a system dynamics (SD) model simulating theradiotherapy (RT) process, the number of patient care pathways (RT workflows) needs to be kept low to simplify the model without affecting the overall performance. A large RT department can have more than 100 workflows, which results in a complex model structure if each is to be handled separately. Here we investigated effects on model performance by reducing the number of workflows for a model of the preparatory steps of the RT process.We created a SD model sub-structure capturing the preparatory RT process. Real data for patients treated in 2015-2016 at a modern RT department in Sweden were used. RT workflow similarity was quantified by averaged pairwise utilization rate differences (%) and the size of corresponding correlation coefficients (r). Grouping of RT workflows was determined using two accepted strategies (80/20 Pareto rule; merging all data into one group) and a customized algorithm with r≥0.75:0.05:0.95 as criteria for group inclusion by two strategies (A1 and A2). Number of waiting patients for each grouping strategy were compared to the reference of all workflows handled separately.There were 128 RT workflows for 3209 patients during the studied period. The 80/20 Pareto rule resulted in 14/8/21 groups for curative/palliative/disregarding treatment intent. Correspondingly, A1 and A2 resulted in 7-40/≤4-36/7-82 groups depending on r cutoff. Results for the Pareto rule and A2 at r≥85 were comparable to the reference.The performance of a simulation model over the RT process will depend on the grouping strategy of patient input data. Either the Pareto rule or the grouping of patients by resource use can be expected to better reflect overall departmental effects to various changes than when merging all data into one group. Our proposed approach to identify groups based on similarity in resource use can potentially be used in any setting with variable incoming flows of objects which go through a multi-step process comparable to RT where the aim is to reduce the complexity of associated model structures without compromising with overall performance.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
|
|
| 31. |
- Lindberg, Jesper, 1983, et al.
(författare)
-
Linear accelerator utilization: Concept and tool to aid the scheduling of patients for radiotherapy.
- 2021
-
Ingår i: Technical innovations & patient support in radiation oncology. - : Elsevier BV. - 2405-6324. ; 20, s. 10-16
-
Tidskriftsartikel (refereegranskat)abstract
- Resources in radiotherapy (RT) need to be used effectively to meet the current clinical demand. The aim of this data-driven study is to identify temporal trends in the scheduling of patients for RT and to develop a tool for a visual overview of future scheduling levels.Scheduling data at an eight-linac modern RT department in Sweden were collected twice daily for planned and observed linac use in 2018-2020. Information was retrieved each day for the present (Day 0) and the forthcoming 100 weekdays with total linac utilization rates (LURs) calculated for two activity categories: treatment and non-treatment. An in-house tool based on the LUR concept, database queries from the oncology information system (OIS)/automatic calculations was developed and evaluated by RT managers and scheduling staff (n=10).Overall median LURs were 87%/89% (planned/observed; p<0.01) with more frequent and larger daily increase for non-treatment activities compared with treatment activities. LUR increased with shorter planning horizons and reached 100% for fully-operating linacs ≈3 weeks before Day 0. The tool was reported by 88% to ease the work and to contribute towards an even scheduling of patients (responses: 8/10).Alterations from a planned RT schedule occurs frequently. Having a tool that helps to reduce the abundance of booking information into clinically relevant overviews promise to increase the understanding of present and future scheduling levels. Our proposed concept and tool suggest that this is a feasible approach to schedule patients for RT more evenly.
|
|
| 32. |
- Lindberg, Jesper, 1983, et al.
(författare)
-
Resource planning principles for the radiotherapy process using simulations applied to a longer vacation period use case.
- 2021
-
Ingår i: Technical innovations & patient support in radiation oncology. - : Elsevier BV. - 2405-6324. ; 20, s. 17-22
-
Tidskriftsartikel (refereegranskat)abstract
- Radiotherapy (RT) resources need to be used wisely to balance workload and patient throughput. There are no known strategies on how to plan resource use around longer vacation periods to avoid patient waiting times. We created a simulation model over the RT workflow to evaluate different scenarios for this purpose.The simulation model mimics a large modern RT department in Sweden. It was based on real data on patient referral patterns and resource use extracted from clinical systems (3666 treatment courses). Workshops with managers and staff were held to investigate nine different scenarios for the summer vacation period including one scenario to validate the model. Different capacity reductions, vacation period lengths and timing of the vacation periods between the preparatory part of the RT workflow and the treatment part were evaluated.For an eight-week period, resource utilization was predicted to be high both before and after the vacation period regardless of timing. However, more patients would be waiting with completed preparations with simultaneous vacation periods than when the preparatory part started one-two weeks prior to the treatment part. With shorter vacation periods, treatment would require overtime during the vacation period with higher levels of patients waiting compared to an eight-week scenario.Our proposed strategy aided managers to identify a preferred scenario for the summer vacation period with the preparatory part starting one-two weeks prior to the treatment part for an eight-week vacation period. This can help other RT departments to plan for similar situations.
|
|
| 33. |
|
|
| 34. |
- Ludvigsson, Jonas F., 1969-, et al.
(författare)
-
Swedish Inflammatory Bowel Disease Register (SWIBREG) : a nationwide quality register
- 2019
-
Ingår i: Scandinavian Journal of Gastroenterology. - : Taylor & Francis. - 0036-5521 .- 1502-7708. ; 54:9, s. 1089-1101
-
Forskningsöversikt (refereegranskat)abstract
- Background: Inflammatory bowel disease (IBD) is a chronic, inflammatory relapsing disease with increasing incidence. IBD research and long-term follow-up of patients have, however, been hampered by lack of detailed data on disease phenotype, patient-reported outcome measures, Physician Global Assessment, disease activity, and hospital-administered drugs.Aim: To review the Swedish IBD quality register (SWIBREG).Methods: Review of SWIBREG including questionnaire data from users and patients.Results: SWIBREG was launched in 2005, and as of April 2019, contains 46,400 patients with IBD (Crohn's disease: n = 15,705, ulcerative colitis: n = 21,540, IBD unclassified and other colitis (including e.g., microscopic colitis): n = 9155). Of these IBD patients, 7778 had been diagnosed in childhood (16.8%). Earlier research has shown that combining SWIBREG and the Swedish National Patient Register (NPR) yields a positive predictive value of 100% (95%CI = 95-100%) for having a diagnosis of IBD. Moreover, out of all patients in the NPR with a diagnosis of IBD plus either IBD-related surgery or immunomodulatory/biological treatment during the past 18 months, SWIBREG covers 59.0%. SWIBREG records not only information on conventional therapies but also on biological treatment, surgery, smoking, disease activity, patient-reported outcome measures (PROMs), and patient-experienced measures (PREMs). Data are presented through a graphical decision support system.Conclusion: SWIBREG benefits patients with IBD, and offers an ideal opportunity for healthcare personnel and researchers to examine disease phenotype and activity, PROMs/PREMs, and hospital-administered drugs in patients with IBD.
|
|
| 35. |
- Nyholm, Tufve, et al.
(författare)
-
A national approach for automated collection of standardized and population-based radiation therapy data in Sweden
- 2016
-
Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 119:2, s. 344-350
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To develop an infrastructure for structured and automated collection of interoperable radiation therapy (RT) data into a national clinical quality registry. Materials and methods: The present study was initiated in 2012 with the participation of seven of the 15 hospital departments delivering RT in Sweden. A national RT nomenclature and a database for structured unified storage of RT data at each site (Medical Information Quality Archive, MIQA) have been developed. Aggregated data from the MIQA databases are sent to a national RT registry located on the same IT platform (INCA) as the national clinical cancer registries. Results: The suggested naming convention has to date been integrated into the clinical workflow at 12 of 15 sites, and MIQA is installed at six of these. Involvement of the remaining 3/15 RT departments is ongoing, and they are expected to be part of the infrastructure by 2016. RT data collection from ARIA (R), Mosaiq (R), Eclipse (TM), and Oncentra (R) is supported. Manual curation of RT-structure information is needed for approximately 10% of target volumes, but rarely for normal tissue structures, demonstrating a good compliance to the RT nomenclature. Aggregated dose/volume descriptors are calculated based on the information in MIQA and sent to INCA using a dedicated service (MIQA2INCA). Correct linkage of data for each patient to the clinical cancer registries on the INCA platform is assured by the unique Swedish personal identity number. Conclusions: An infrastructure for structured and automated prospective collection of syntactically inter operable RT data into a national clinical quality registry for RT data is under implementation. Future developments include adapting MIQA to other treatment modalities (e.g. proton therapy and brachytherapy) and finding strategies to harmonize structure delineations. How the RT registry should comply with domain-specific ontologies such as the Radiation Oncology Ontology (ROO) is under discussion.
|
|
| 36. |
- Oh, J. H., et al.
(författare)
-
A Factor Analysis Approach for Clustering Patient Reported Outcomes
- 2016
-
Ingår i: Methods of Information in Medicine. - : Georg Thieme Verlag KG. - 0026-1270 .- 2511-705X. ; 55:5, s. 431-439
-
Tidskriftsartikel (refereegranskat)abstract
- Background: In the field of radiation oncology, the use of extensive patient reported outcomes is increasingly common to measure adverse side effects after radiotherapy in cancer patients. Factor analysis has the potential to identify an optimal number of latent factors (i.e., symptom groups). However, the ultimate goal of treatment response modeling is to understand the relationship between treatment variables such as radiation dose and symptom groups resulting from FA. Hence, it is crucial to identify clinically more relevant symptom groups and improved response variables from those symptom groups for a quantitative analysis. Objectives: The goal of this study is to design a computational method for finding clinically relevant symptom groups from PROs and to test associations between symptom groups and radiation dose. Methods: We propose a novel approach where exploratory factor analysis is followed by confirmatory factor analysis to determine the relevant number of symptom groups. We also propose to use a combination of symptoms in a symptom group identified as a new response variable in linear regression analysis to investigate the relationship between the symptom group and dose-volume variables. Results: We analyzed patient-reported gastrointestinal symptom profiles from 3 datasets in prostate cancer patients treated with radiotherapy. The final structural model of each dataset was validated using the other two datasets and compared to four other existing FA methods. Our systematic EFA-CFA approach provided clinically more relevant solutions than other methods, resulting in new clinically relevant outcome variables that enabled a quantitative analysis. As a result, statistically significant correlations were found between some dose volume variables to relevant anatomic structures and symptom groups identified by FA. Conclusions: Our proposed method can aid in the process of understanding PROs and provide a basis for improving our understanding of radiation-induced side effects.
|
|
| 37. |
- Olsson, Caroline, 1970, et al.
(författare)
-
A Systematic Post-QUANTEC Review of Tolerance Doses for Late Toxicity After Prostate Cancer Radiation Therapy
- 2018
-
Ingår i: International Journal of Radiation Oncology Biology Physics. - : Elsevier BV. - 0360-3016. ; 102:5, s. 1514-1532
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aims of this study were to systematically review tolerance doses for late distinct gastrointestinal (GI), genitourinary (GU), and sexual dysfunction (SD) symptoms after external beam radiation therapy (EBRT) alone and treatments involving brachytherapy (BT) for prostate cancer after Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) and ultimately to perform quantitative syntheses of identified dose/volume tolerances represented by dose-volume histogram (DVH) thresholds, that is, statistically significant (P ≤.05) cutoff points between symptomatic and asymptomatic patients in a certain study. Methods and Materials: PubMed was scrutinized for full-text articles in English after QUANTEC (January 1, 2010). The inclusion criteria were randomized controlled trials, case-control studies, or cohort studies with tolerance doses for late distinct symptoms ≥3 months after primary radiation therapy for prostate cancer (N > 30). All DVH thresholds were converted into equivalent doses in 2-Gy fractions (EQD2α/β) and were fitted with a linear or linear-quadratic function (goodness of fit, R2). The review was registered on PROSPERO (CRD42016042464). Results: From 33 identified studies, which included 36 to 746 patients per symptom domain, the majority of dose/volume tolerances were derived for GI toxicity after EBRT alone (GI, 97 thresholds; GU, 8 thresholds; SD, 1 threshold). For 5 symptoms (defecation urgency, diarrhea, fecal incontinence, proctitis, and rectal bleeding), relationships between dose/volume tolerances across studies (R2 = 0.93 [0.82-1.00]), and across symptoms, leading to a curve for overall GI toxicity (R2 = 0.98), could be determined. For these symptoms, mainly rectal thresholds were found throughout low and high doses (10 Gy ≤ equivalent dose in 2-Gy fractions using α/β = 3Gy (EQD23) ≤ 50 Gy and 55 Gy ≤ EQD23 ≤ 78 Gy, respectively). For BT with or without EBRT, dose/volume tolerances were also mainly identified for GI toxicity (GI, 14 thresholds; GU, 4 thresholds; SD, 2 thresholds) with the largest number of DVH thresholds concerning rectal bleeding (5 thresholds). Conclusions: Updated dose/volume tolerances after QUANTEC were found for 17 GI, GU, or SD symptoms. A DVH curve described the relationship between dose/volume tolerances across 5 GI symptoms after EBRT alone. Restricting treatments for EBRT alone using the lower boundaries of this curve is likely to limit overall GI toxicity, but this should be explored prospectively. Dose/volume tolerances for GU and SD toxicity after EBRT alone and after BT with or without EBRT were scarce and support further research including data-sharing initiatives to untangle the dose/volume relationships for these symptoms. © 2018 Elsevier Inc.
|
|
| 38. |
- Olsson, Caroline, 1970, et al.
(författare)
-
Autosegmentation based on different-sized training datasets of consistently-curated volumes and impact on rectal contours in prostate cancer radiation therapy
- 2022
-
Ingår i: Physics and imaging in radiation oncology (PIRO). - : Elsevier BV. - 2405-6316. ; 22, s. 67-72
-
Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Autosegmentation techniques are emerging as time-saving means for radiation therapy (RT) contouring, but the understanding of their performance on different datasets is limited. The aim of this study was to determine agreement between rectal volumes by an existing autosegmentation algorithm and manually-delineated rectal volumes in prostate cancer RT. We also investigated contour quality by differentsized training datasets and consistently-curated volumes for retrained versions of this same algorithm. Materials and methods: Single-institutional data from 624 prostate cancer patients treated to 50-70 Gy were used. Manually-delineated clinical rectal volumes (clinical) and consistently-curated volumes recontoured to one anatomical guideline (reference) were compared to autocontoured volumes by a commercial autosegmentation tool based on deep-learning (v1; n = 891, multiple-institutional data) and retrained versions using subsets of the curated volumes (v32/64/128/256; n = 32/64/128/256). Evaluations included dose-volume histogram metrics, Dice similarity coefficients, and Hausdorff distances; differences between groups were quantified using parametric or non-parametric hypothesis testing. Results: Volumes by v1-256 (76-78 cm(3)) were larger than reference (75 cm(3)) and clinical (76 cm(3)). Mean doses by v1-256 (24.2-25.2 Gy) were closer to reference (24.2 Gy) than to clinical (23.8 Gy). Maximum doses were similar for all volumes (65.7-66.0 Gy). Dice for v1-256 and reference (0.87-0.89) were higher than for v1-256 and clinical (0.86-0.87) with corresponding Hausdorff comparisons including reference smaller than comparisons including clinical (5-6 mm vs. 7-8 mm). Conclusion: Using small single-institutional RT datasets with consistently-defined rectal volumes when training autosegmentation algorithms created contours of similar quality as the same algorithm trained on large multiinstitutional datasets.
|
|
| 39. |
|
|
| 40. |
- Olsson, Caroline, 1970, et al.
(författare)
-
Influence of image slice thickness on rectal dose-response relationships following radiotherapy of prostate cancer.
- 2014
-
Ingår i: Physics in medicine and biology. - : IOP Publishing. - 1361-6560 .- 0031-9155. ; 59:14, s. 3749-3759
-
Tidskriftsartikel (refereegranskat)abstract
- When pooling retrospective data from different cohorts, slice thicknesses of acquired computed tomography (CT) images used for treatment planning may vary between cohorts. It is, however, not known if varying slice thickness influences derived dose-response relationships. We investigated this for rectal bleeding using dose-volume histograms (DVHs) of the rectum and rectal wall for dose distributions superimposed on images with varying CT slice thicknesses. We used dose and endpoint data from two prostate cancer cohorts treated with three-dimensional conformal radiotherapy to either 74 Gy (N = 159) or 78 Gy (N = 159) at 2 Gy per fraction. The rectum was defined as the whole organ with content, and the morbidity cut-off was Grade ≥2 late rectal bleeding. Rectal walls were defined as 3mm inner margins added to the rectum. DVHs for simulated slice thicknesses from 3 to 13mm were compared to DVHs for the originally acquired slice thicknesses at 3 and 5mm. Volumes, mean, and maximum doses were assessed from the DVHs, and generalized equivalent uniform dose (gEUD) values were calculated. For each organ and each of the simulated slice thicknesses, we performed predictive modeling of late rectal bleeding using the Lyman-Kutcher-Burman (LKB) model. For the most coarse slice thickness, rectal volumes increased (≤18%), whereas maximum and mean doses decreased (≤0.8 and ≤4.2Gy, respectively). For all a values, the gEUD for the simulated DVHs were ≤1.9Gy different than the gEUD for the original DVHs. The best-fitting LKB model parameter values with 95% CIs were consistent between all DVHs. In conclusion, we found that the investigated slice thickness variations had minimal impact on rectal dose-response estimations. From the perspective of predictive modeling, our results suggest that variations within 10mm in slice thickness between cohorts are unlikely to be a limiting factor when pooling multi-institutional rectal dose data that include slice thickness variations within this range.
|
|
| 41. |
- Olsson, Caroline, 1970, et al.
(författare)
-
Patient-reported genitourinary toxicity for long-term prostate cancer survivors treated with radiation therapy.
- 2013
-
Ingår i: British journal of cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 108:10, s. 1964-70
-
Tidskriftsartikel (refereegranskat)abstract
- Background:The objective of this study is to provide comprehensive overviews of patient-reported urinary symptoms for long-term prostate cancer survivors treated with radiation therapy and for untreated, healthy men.Methods:We performed a population-based cross-sectional study using a study-specific postal questionnaire assessing symptoms among 1007 men consecutively treated at the Sahlgrenska University Hospital, Göteborg, Sweden from 1993-2006 (primary or salvage external beam radiation therapy (EBRT) or EBRT and high-dose rate brachytherapy). We also randomly recruited 350 non-pelvic-irradiated matched control men from the Swedish Total Population Register. Symptom prevalence and prevalence ratios were computed.Results:Survey participation rate was 89% (874/985) for eligible survivors and 73% (243/332) for eligible controls. Median time from treatment to follow-up was 5 years (range, 1-14 years). Among the 21 investigated symptoms reflecting obstruction, frequency, urgency, pain and incontinence, we found significantly higher prevalence compared with controls for 9 symptoms in the EBRT group, 10 in the EBRT+brachytherapy group and 5 in the salvage EBRT group. The prevalence for a majority of the symptoms was stable over time.Conclusion:The presented toxicity profiles provide a thorough understanding of patient-reported urinary symptoms that can assist in developing personalised therapy for prostate cancer.
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
- Olsson, Caroline, 1970
(författare)
-
Predicting Normal Tissue Complications after External Beam Radiation Therapy
- 2010
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Although modern external beam radiation (EBRT) therapy has the ability to conform the dose tightly around the volume to be treated, unwanted irradiation to surrounding normal tissue is still a problem. The probability of a side effect arising in normal tissue after EBRT is commonly modelled by an s-shaped dose-volume response curve where dose or volume are plotted against response (i.e. the frequency with which the side effect occurs). The models are based on sigmoid mathematical functions and are fitted to input data representing the outcome (absence or presence of the studied symptom associated with the side effect) and the dose distribution for potentially injured organs using statistical methods. The purpose of this thesis is to give an overview of the current forms of outcome and dose data, how they are generated and used to model side effects today, some of their limitations, and potential future directions. The results are based on concepts from the literature as well as from the three appended papers. The first two present questionnaire-collected outcome data and 2D dose-volume histogram data of the pubic bone for 650 long-term gynecological cancer survivors treated with pelvic radiation therapy between 1991 and 2003 where one in every ten women reported pubic bone pain. The mean dose to the pubic bone proved critical for pain occurrence and the risk to experience pubic bone pain two or more years after pelvic radiation therapy is expected to be 5 % for a mean absorbed dose of 25 Gy. The third paper presents dose differences between non-corrected and fractionation-corrected combined doses in sequential two-phase treatments using 16 combined dose distributions over a model organ at risk (OAR) “irradiated” with a conventional fractionation schedule (2 Gy per fraction; 46 Gy + 22 Gy). Dose differences up to 6 Gy (50 % of a reference total dose
|
|
| 45. |
- Olsson, Caroline, 1970
(författare)
-
Radiation Oncology Data and Modelling Side Effects after Radiation Therapy
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Although modern radiation therapy techniques have the ability to conform the dose distribution of ionizing radiation tightly around the volume to be treated, unwanted irradiation to surrounding organs remains a problem. The probability of a side effect arising in the normal tissue of a patient after radiation therapy can be modelled by sigmoid mathematical functions known as normal tissue complication probability (NTCP) models. Using statistical methods, these are fitted to input data representing the absence or presence of a studied symptom associated with the side effect in question and the dose distribution for potentially injured organs. NTCP models are increasingly being used in the clinic both for treatment evaluation and to guide optimization algorithms for inverse treatment planning although their predictions are associated with uncertainties to varying degrees. The purpose of this thesis is to investigate how different means to represent dose and ways to grade side effects contribute to uncertainties in radiation therapy side effect modelling. Using concepts from the literature and results from two recent Swedish studies including data on parotid gland complications in head and neck cancer patients and pubic bone pain in gynaecological cancer patients, respectively, current generations and representations of dose and side effect data and how these are used in modelling side effects are surveyed. Using similarities and differences in the data by the literature and these two studies, it is concluded that dose data for modelling purposes today is described by dose-volume histograms but can be made more detailed using a three-dimensional format like the structure-specific dose matrix as introduced in this thesis with additional information on dose representation. Side effect data are described by different scales to grade the same or similar symptoms, but also need to include information on factors which may influence modelling results such as effect-modifying factors as well as baseline symptom frequencies in non-irradiated individuals. Altogether, 15 items that capture the essential information needed for radiation therapy side effect modelling are identified, and the outlook for data integration and interoperability in radiation oncology would be improved by using these to form a semantic basis for this domain.
|
|
| 46. |
|
|
| 47. |
- Olsson, Caroline, 1970, et al.
(författare)
-
Standardizing radiation oncology data for future modelling of side effects after radiation therapy
- 2011
-
Ingår i: 1st International Workshop on Managing Interoperability and compleXity in Health Systems, MIXHS'11, Collocated with the 20th ACM International Conference on Information and Knowledge Management, CIKM 2011 Glasgow 28 October 2011 through 28 October 2011. - New York, NY, USA : ACM. - 9781450309547 ; oct 28, s. 67-70
-
Konferensbidrag (refereegranskat)abstract
- Wider acceptance of data standards in radiation oncology would facilitate pooling of data from different studies. In turn, this would help clinicians and medical physicists to better understand the relationships between radiation treatments and consequent late developing side effects, and to design treatment plans that improve patients' quality of life. In this paper, we describe challenges of collecting and integrating radiation oncology data from medical records and treatment planning systems for the purpose of modelling side effects after radiation therapy. © 2011 ACM.
|
|
| 48. |
- Pettersson, Niclas, 1974, et al.
(författare)
-
A method to estimate composite doses for organs at risk in prostate cancer patients treated with EBRT in combination with HDR BT.
- 2014
-
Ingår i: Acta oncologica (Stockholm, Sweden). - 1651-226X. ; 53:6, s. 815-821
-
Tidskriftsartikel (refereegranskat)abstract
- Background. When evaluating late toxicity after combined external beam radiation therapy (EBRT) and high-dose rate brachytherapy (HDR BT) prostate cancer treatments, it is important that the composite dose distribution is taken into account. This can be challenging if organ-at-risk (OAR) dose data are incomplete, i.e. due to a limited ultrasound imaging field-of-view in the HDR BT procedure. This work proposes a method that provides estimates of composite OAR doses for such situations. Material and methods. Original EBRT, simulated HDR BT, and composite dose-volume histograms (DVHs) for 10 pelvic OARs in 30 prostate cancer cases were used for method implementation and evaluation (EBRT: 25 × 2.0 Gy + BT: 2 × 10.0 Gy). The proposed method used information from the EBRT DVH to estimate OAR BT doses (with or without fractionation correction). Coefficients of determination (R(2)) were calculated for linear relationships between several EBRT DVH parameters and a BT DVH parameter of interest. The largest R(2) value decided the relationship that best predicted the BT DVH parameter. The composite dose value was then calculated by adding the EBRT DVH and the estimated BT DVH parameter values and was compared to the reference composite value (in 1200 OAR/patient/parameter cases). Results. The linear relationships had an average R(2) of 0.68 (range 0.42-0.88). Only one ninth of the 1200 estimated composite DVH values differed more than 2 Gy from their reference values. Conclusion. Given a successful implementation, the proposed method only requires original or simulated BT plan data for a subset of patients to estimate composite doses for large study populations in a time-efficient manner. This can assist in evaluating radiation-induced late toxicity in multimodality treatments with limited OAR dose data.
|
|
| 49. |
|
|
| 50. |
- Thor, Maria, et al.
(författare)
-
Radiation Dose to the Penile Structures and Patient-Reported Sexual Dysfunction in Long-Term Prostate Cancer Survivors.
- 2015
-
Ingår i: The journal of sexual medicine. - : Oxford University Press (OUP). - 1743-6109 .- 1743-6095. ; 12:12, s. 2388-2397
-
Tidskriftsartikel (refereegranskat)abstract
- The involvement of various penile structures in radiotherapy (RT)-induced sexual dysfunction among prostate cancer survivors remains unclear and domains beyond erectile dysfunction such as orgasm, and pain have typically not been considered. The purpose of this study was to investigate sexual dysfunction post-RT for localized prostate cancer and to examine whether radiation dose to different penile structures can explain these symptoms.
|
|
