| 1. |
- Rutegård, Miriam, et al.
(författare)
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PET/MRI and PET/CT hybrid imaging of rectal cancer - description and initial observations from the RECTOPET (REctal Cancer trial on PET/MRI/CT) study
- 2019
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Ingår i: Cancer Imaging. - : BMC. - 1740-5025 .- 1470-7330. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe role of hybrid imaging using F-18-fluoro-2-deoxy-D-glucose positron-emission tomography (FDG-PET), computed tomography (CT) and magnetic resonance imaging (MRI) to improve preoperative evaluation of rectal cancer is largely unknown. To investigate this, the RECTOPET (REctal Cancer Trial on PET/MRI/CT) study has been launched with the aim to assess staging and restaging of primary rectal cancer. This report presents the study workflow and the initial experiences of the impact of PET/CT on staging and management of the first patients included in the RECTOPET study.MethodsThis prospective cohort study, initiated in September 2016, is actively recruiting patients from Region Vasterbotten in Sweden. This pilot study includes patients recruited and followed up until December 2017. All patients had a biopsy-verified rectal adenocarcinoma and underwent a minimum of one preoperative FDG-PET/CT and FDG-PET/MRI examination. These patients were referred to the colorectal cancer multidisciplinary team meeting at Umea University Hospital. All available data were evaluated when making management recommendations. The clinical course was noted and changes consequent to PET imaging were described; surgical specimens underwent dedicated MRI for anatomical matching between imaging and histopathology.ResultsTwenty-four patients have so far been included in the study. Four patients were deemed unresectable, while 19 patients underwent or were scheduled for surgery; one patient was enrolled in a watch-and-wait programme after restaging. Consequent to taking part in the study, two patients were upstaged to M1 disease: one patient was diagnosed with a solitary hepatic metastasis detected using PET/CT and underwent metastasectomy prior to rectal cancer surgery, while one patient with a small, but metabolically active, lung nodulus experienced no change of management. PET/MRI did not contribute to any recorded change in patient management.ConclusionsThe RECTOPET study investigating the role of PET/CT and PET/MRI for preoperative staging of primary rectal cancer patients will provide novel data that clarify the value of adding hybrid to conventional imaging, and the role of PET/CT versus PET/MRI.Trial registrationNCT03846882.
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| 2. |
- Rutegård, Miriam, et al.
(författare)
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Rectal cancer : a methodological approach to matching PET/MRI to histopathology
- 2020
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Ingår i: Cancer Imaging. - : BioMed Central (BMC). - 1740-5025 .- 1470-7330. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To enable the evaluation of locoregional disease in the on-going RECTOPET (REctal Cancer Trial on PET/MRI/CT) study; a methodology to match mesorectal imaging findings to histopathology is presented, along with initial observations.Methods: FDG-PET/MRI examinations were performed in twenty-four consecutively included patients with rectal adenocarcinoma. In nine patients, of whom five received neoadjuvant treatment, a postoperative MRI of the surgical specimen was performed. The pathological cut-out was performed according to clinical routine with the addition of photo documentation of each slice of the surgical specimen, meticulously marking the location, size, and type of pathology of each mesorectal finding. This allowed matching individual nodal structures from preoperative MRI, via the specimen MRI, to histopathology.Results: Preoperative MRI identified 197 mesorectal nodal structures, of which 92 (47%) could be anatomically matched to histopathology. Of the matched nodal structures identified in both MRI and histopathology, 25% were found to be malignant. These malignant structures consisted of lymph nodes (43%), tumour deposits (48%), and extramural venous invasion (9%). One hundred eleven nodal structures (55%) could not be matched anatomically. Of these, 97 (87%) were benign lymph nodes, and 14 (13%) were malignant nodal structures. Five were malignant lymph nodes, and nine were tumour deposits, all of which had a short axis diameter < 5 mm.Conclusions: We designed a method able to anatomically match and study the characteristics of individual mesorectal nodal structures, enabling further research on the impact of each imaging modality. Initial observations suggest that small malignant nodal structures assessed as lymph nodes in MRI often comprise other forms of mesorectal tumour spread.Trial registration: Clinical Trials Identifier: NCT03846882.
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| 3. |
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| 4. |
- Back, Erik, et al.
(författare)
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Mucosal blood flow in the remaining rectal stump is more affected by total than partial mesorectal excision in patients undergoing anterior resection : a key to understanding differing rates of anastomotic leakage?
- 2021
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Ingår i: Langenbeck's archives of surgery (Print). - : Springer. - 1435-2443 .- 1435-2451. ; 406:6, s. 1971-1977
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Anterior resection is the procedure of choice for tumours in the mid and upper rectum. Depending on tumour height, a total mesorectal excision (TME) or partial mesorectal excision (PME) can be performed. Low anastomoses in particular have a high risk of developing anastomotic leakage, which might be explained by blood perfusion compromise. A pilot study indicated a worse blood flow in TME patients in an open setting. The aim of this study was to further evaluate perianastomotic blood perfusion changes in relation to TME and PME in a predominantly laparoscopic context.METHOD: In this prospective cohort study, laser Doppler flowmetry was used to evaluate the perianastomotic colonic and rectal perfusion before and after surgery. The two surgical techniques were compared in terms of mean differences of perfusion units using a repeated measures ANOVA design, which also enabled interaction analyses between type of mesorectal excision and location of measurement. Anastomotic leakage until 90 days after surgery was reported for descriptive purposes.RESULTS: Some 28 patients were available for analysis: 17 TME and 11 PME patients. TME patients had a reduced blood perfusion postoperatively compared to PME patients in the aboral posterior area (mean difference: -57 vs 18 perfusion units; p = 0.010). An interaction between mesorectal excision type and anterior/posterior location was detected at the aboral level (p = 0.007). Two patients developed a minor leakage, diagnosed after discharge.CONCLUSION: Patients operated on using TME have a decreased blood flow in the aboral posterior quadrant of the rectum postoperatively compared to patients operated on using PME. This might explain differing rates of anastomotic leakage.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02401100.
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| 5. |
- Back, Erik, et al.
(författare)
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Permanent stoma rates after anterior resection for rectal cancer : risk prediction scoring using preoperative variables
- 2021
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Ingår i: British Journal of Surgery. - : Oxford University Press. - 0007-1323 .- 1365-2168. ; 108:11, s. 1388-1395
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A permanent stoma after anterior resection for rectal cancer is common. Preoperative counselling could be improved by providing individualized accurate prediction modelling.METHODS: Patients who underwent anterior resection between 2007 and 2015 were identified from the Swedish Colorectal Cancer Registry. National Patient Registry data were added to determine presence of a stoma 2 years after surgery. A training set based on the years 2007-2013 was employed in an ensemble of prediction models. Judged by the area under the receiving operating characteristic curve (AUROC), data from the years 2014-2015 were used to evaluate the predictive ability of all models. The best performing model was subsequently implemented in typical clinical scenarios and in an online calculator to predict the permanent stoma risk.RESULTS: Patients in the training set (n = 3512) and the test set (n = 1136) had similar permanent stoma rates (13.6 and 15.2 per cent). The logistic regression model with a forward/backward procedure was the most parsimonious among several similarly performing models (AUROC 0.67, 95 per cent c.i. 0.63 to 0.72). Key predictors included co-morbidity, local tumour category, presence of metastasis, neoadjuvant therapy, defunctioning stoma use, tumour height, and hospital volume; the interaction between age and metastasis was also predictive.CONCLUSION: Using routinely available preoperative data, the stoma outcome at 2 years after anterior resection for rectal cancer can be predicted fairly accurately.
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| 6. |
- Bostrom, Petrus, et al.
(författare)
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Arterial ligation in anterior resection for rectal cancer : A validation study of the Swedish Colorectal Cancer Registry
- 2014
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Ingår i: Acta Oncologica. - : Informa Healthcare. - 0284-186X .- 1651-226X. ; 53:7, s. 892-897
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Tidskriftsartikel (refereegranskat)abstract
- Background: The level of arterial ligation has been a variable of the Swedish Colorectal Cancer Registry since 2007. The aim of this study is to evaluate the accuracy of this registry variable in relation to anterior resection for rectal cancer.Methods: The operative charts of all cardiovascularly compromised patients who underwent anterior resection during the period 2007-2010 in Sweden were retrieved and compared to the registry. We selected the study population to reflect the common assumption that these patients would be more sensitive to a compromised visceral blood flow. Levels of vascular ligation were defined, both oncologically and functionally, and their sensitivity, specificity, positive and negative predictive values, level of agreement and Cohen's kappa were calculated.Results: Some 744 (94.5%) patients were eligible for analysis. Functional high tie level showed a sensitivity of 80.2% and a specificity of 90.1%. Positive and negative predictive values were 87.7 and 83.8%, respectively. Level of agreement was 85.5% and Cohen's kappa 0.70. The corresponding calculations for oncologic tie level yielded similar results.Conclusion: The suboptimal validity of the Swedish Colorectal Cancer Registry regarding the level of vascular ligation might be problematic. For analyses with rare positive outcomes, such bowel ischaemia, or with minor expected differences in outcomes, it would be beneficial to collect data directly from the operative charts of the medical records in order to increase the chance of identifying clinically relevant differences.
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| 7. |
- Boström, Petrus, et al.
(författare)
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Oncological Impact of High Vascular Tie After Surgery for Rectal Cancer : A Nationwide Cohort Study
- 2021
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Ingår i: Annals of Surgery. - : Wolters Kluwer. - 0003-4932 .- 1528-1140. ; 274:3, s. e236-e244
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The purpose of this study was to investigate the impact of tie level on oncological outcomes in rectal cancer surgery.Summary background data: Theoretically, a high tie of the inferior mesenteric artery could facilitate removal of apical node metastases and improve tumor staging accuracy. However, no appropriately sized randomized controlled trial exists and results from observational studies are not consistent.Methods: All stage I–III rectal cancer patients who underwent abdominal surgery with curative intention in 2007 to 2014 were identified and followed, using the Swedish Colorectal Cancer Registry. Primary outcome was cancer-specific survival, whereas overall and relative survival, locoregional and distant recurrence, and lymph node harvest were secondary outcomes, with high tie as exposure. We used propensity score matching to emulate a randomized controlled trial, and then performed Cox regression analyses to estimate hazard ratios (HRs) with confidence intervals (CIs).Results: Some 8287 patients remained for analysis, of which 37% had high tie surgery. After propensity score matching, the 5-year cancer-specific survival rate was overall 86% and we found no association between the level of tie and cancer-specific (HR 0.92, 95% CI 0.79–1.07) or overall (HR 0.98, 95% CI 0.89–1.08) survival, nor to locoregional (HR 0.85, 95% CI 0.59–1.23) or distant (HR 1.01, 95% CI 0.88–1.15) recurrence, nor to relative survival (HR 1.05, 95% CI 0.85–1.28). Stratification and sensitivity analyses were similarly insignificant, after adjustment for confounding. Total lymph node harvest was, however, increased after high tie surgery (P < 0.01), but no differences were seen regarding positive nodes (P = 0.72).Conclusion: In this nationwide cohort study, the level of tie did not influence any patient-oriented oncological outcome, neither overall nor in node-positive patients. This would allow the patient's anatomical configuration and the surgeon's preferences to determine the level of tie.
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| 8. |
- Boström, Petrus, et al.
(författare)
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Population‐based cohort study of the impact on postoperative mortality of anastomotic leakage after anterior resection for rectal cancer
- 2019
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Ingår i: BJS Open. - : John Wiley & Sons. - 2474-9842. ; 3:1, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- Background: Anastomotic leakage following anterior resection for rectal cancer may result in death. The aim of this study was to yield an updated, population‐based estimate of postoperative mortality and evaluate possible interacting factors.Methods: This was a retrospective national cohort study of patients who underwent anterior resection between 2007 and 2016. Data were retrieved from a prospectively developed database. Anastomotic leakage constituted exposure, whereas outcome was defined as death within 90 days of surgery. Logistic regression analyses, using directed acyclic graphs to evaluate possible confounders, were performed, including interaction analyses.Results: Of 6948 patients, 693 (10·0 per cent) experienced anastomotic leakage and 294 (4·2 per cent) underwent reintervention due to leakage. The mortality rate was 1·5 per cent in patients without leakage and 3·9 per cent in those with leakage. In multivariable analysis, leakage was associated with increased mortality only when a reintervention was performed (odds ratio (OR) 5·57, 95 per cent c.i. 3·29 to 9·44). Leaks not necessitating reintervention did not result in increased mortality (OR 0·70, 0·25 to 1·96). There was evidence of interaction between leakage and age on a multiplicative scale (P = 0·007), leading to a substantial mortality increase in elderly patients with leakage.Conclusion: Anastomotic leakage, in particular severe leakage, led to a significant increase in 90‐day mortality, with a more pronounced risk of death in the elderly.
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| 9. |
- Boström, Petrus, 1981-
(författare)
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Rectal cancer : the influence of surgical technique on morbidity, mortality and survival
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Surgery is still the most common treatment for rectal cancer, being the most effective and cost-efficient modality. However, it is not without risk, nor without controversies. This dissertation is an evaluation of the pros and cons of high versus low ligation, whether anastomotic leakage is still prevalent after surgery and associated with increased mortality, and if the risk of leakage could be predicted by early postoperative pain.Study I relied upon case records and registry data to evaluate the causal effect of high ligation on the risk of anastomotic leakage after anterior resection in 722 patients with increased cardiovascular risk. When controlling for confounders, no association was found overall. However, an increased risk for leakage after high ligation was noted for the few patients who suffered from both manifest cardiovascular disease and ASA III–IV (OR 3.66, 95% CI 1.04–12.85) and when performed in a low volume hospital (OR 3.89, 95% 1.58– 9.59). Study II estimated the risk of anastomotic leakage and death after anterior resection today. Among the 6,948 patients, 10.0% suffered from leakage, in whom mortality was 3.9% versus 1.5% for patients without a leak. However, this increased mortality was driven entirely by patients in need of reintervention, who exhibited a 7.5% 90-day mortality, resulting in a significantly increased risk (OR 5.57, 95% CI 3.29–9.44), when controlling for confounders, while conservatively treated leakage was not associated with mortality. Age acted as an effect modifier, as postoperative mortality after leakage was increased in the elderly.Study III returned to high versus low ligation as exposure, to evaluate the long-term oncological benefits of either ligation level, with cancer-specific survival as primary outcome. The final cohort of 8,287 patients who underwent abdominal surgery for rectal cancer, with curative intent, was followed for a minimum of 3.5 years. After propensity score matching, no significant differences were found between high and low ligation for any survival or recurrence analysis, nor in the unmatched cohort, when controlling for confounders. A statistically significant difference was found for lymph node harvest, which was slightly greater in high ligation (17.7 vs 16.7 lymph nodes). Finally, study IV estimated the independent predictive ability of postoperative pain, measured on the numerical rating scale (NRS), on the risk for anastomotic leakage after colorectal cancer surgery. It seems as if increased early pain is an independent predictor for leakage (OR 1.73, 95% CI 1.22– 2.46 for NRS 4–10), with increasing risk of leakage with increasing pain (OR 2.42 for NRS 8–10). In addition, increased pain was more strongly associated with more severe leakage.In summary, the level of ligation seems to be of importance only in a select group of high-risk patients, but offers no obvious oncological advantages. The high incidence and serious sequelae of anastomotic leakage makes it one of the most important clinical challenges in colorectal surgery, with especially detrimental effects in the elderly. A better understanding of the causal pathways behind leakage, and the overall harm and benefit of ligation level and diverting stomas, might allow a better selection of treatment for future patients.
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