| 1. |
- Ek, Hanna, et al.
(författare)
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Transitioning from conventional photon therapy to proton therapy for primary brain tumors
- 2023
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Ingår i: Acta oncologica (Stockholm, Sweden). - 1651-226X. ; 62:4, s. 391-399
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Proton radiation therapy (PT) has become a treatment option alongside photon therapy (XRT) for lower-grade gliomas (LGG). In this single-institution retrospective study, we investigate the patient characteristics and treatment outcomes, including pseudo-progression (PsP), for LGG patients selected for PT. Method: Adult patients with grade 2–3 glioma consecutively treated with radiotherapy (RT) from May 2012 to December 2019 were retrospectively included in this cohort study. Tumor characteristics and treatment data were collected. The groups treated with PT and XRT were compared regarding treatment characteristics, side effects, occurrence of PsP, and survival outcomes. PsP was defined as new or growing lesions followed by either decrease or stabilization during a 12 month-period with no treatment. Results: Out of 143 patients meeting the inclusion criteria, 44 were treated with PT, 98 with XRT and one with mixed PT + XRT. The patients receiving PT were younger, had a lower tumor grade, more oligodendrogliomas and received a lower mean brain and brainstem dose. PsP was observed in 21 out of 126 patients, with no difference between XRT and PT (p =.38). The rate of fatigue in immediate connection to RT (zero to three months after) was higher for XRT than for PT (p =.016). The PT patients had a significantly better PFS and OS than the XRT patients (p =.025 and.035), but in multivariate analysis radiation modality was non-significant. Higher average dose to both brain and brainstem was associated with inferior PFS and OS (p <.001). Median follow-up time were 69 months and 26 months for XRT and PT patients, respectively. Conclusion: Contrary to previous studies, there was no difference in risk of PsP for XRT and PT. PT was associated with lower rates of fatigue <3 months after RT. The superior survival outcomes for PT indicates that the patients with the best prognosis were referred to PT.
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| 2. |
- Munck af Rosenschöld, Per, et al.
(författare)
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Impact of [18F]-fluoro-ethyl-tyrosine PET imaging on target definition for radiation therapy of high-grade glioma.
- 2015
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Ingår i: Neuro-Oncology. - : Oxford University Press (OUP). - 1523-5866 .- 1522-8517. ; 17:5, s. 757-763
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Tidskriftsartikel (refereegranskat)abstract
- We sought to assess the impact of amino-acid (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade glioma versus the current standard using MRI alone. Specifically, we investigated the influence of tumor grade, MR-defined tumor volume, and the extent of surgical resection on PET positivity.
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| 3. |
- Askaner, Krister, et al.
(författare)
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Differentiation of Brain Metastases due to Primary Malignancy and Glioblastomas using Dynamic Susceptibility Contrast-Enhanced MR at 3T
- 2017
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Konferensbidrag (refereegranskat)abstract
- Purpose:To find out differences in cerebral blood volume (CBV) maps derived from dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSCE-MRI) in glioblastomas and cerebral metastases. The main purpose was to compare CBV maps between metastases with different primary malignancies. Furthermore the metastasis group was compared with the glioblastoma group.Method:Conventional imaging and DSCE-MRI using 3T MRI system was performed in 114 patients, 38 glioblastomas and 76 metastases, 32 lung, 12 breast, 12 melanoma, 10 gastrointestinal (GI), and 10 other. CBV values were measured in the solid tumor area, peritumoral edema, area adjacent to peritumoral edema, and in normal apparent white matter in contralateral semioval center. The four subgroups of metastases were compared with one-way ANOVA to determine differences in CBV of significance. CBV values in glioblastomas and metastases were then statistically compared using paired t-test. Receiver -operating characteristic analysis was used to determine optimal cut-off values when parameters showed statistical differences.Results:There were no significantly differences in CBV between the four subgroups of metastases. CBV in the peritumoral edema significantly differentiated metastases from glioblastomas, p=0.0001. CBV cutoff value of 2.3 yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 87, 87, 71, and 91% respectively. Conclusions:Differentiation of glioblastomas and metastases is possible using DSCE-MRI. No statistically significant differences regarding CBV between metastases from lung, breast, melanoma, and GI were detected.
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| 4. |
- Durmo, Faris, et al.
(författare)
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Brain Tumor Characterization Using Multibiometric Evaluation of MRI
- 2018
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Ingår i: Tomography : a journal for imaging research. - : MDPI AG. - 2379-1381. ; 4:1, s. 14-25
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to evaluate volume, diffusion, and perfusion metrics for better presurgical differentiation between high-grade gliomas (HGG), low-grade gliomas (LGG), and metastases (MET). For this retrospective study, 43 patients with histologically verified intracranial HGG (n = 18), LGG (n = 10), and MET (n = 15) were chosen. Preoperative magnetic resonance data included pre- and post-gadolinium contrast-enhanced T1-weighted fluid-attenuated inversion recover, cerebral blood flow (CBF), cerebral blood volume (CBV), fractional anisotropy, and apparent diffusion coefficient maps used for quantification of magnetic resonance biometrics by manual delineation of regions of interest. A binary logistic regression model was applied for multiparametric analysis and receiver operating characteristic (ROC) analysis. Statistically significant differences were found for normalized-ADC-tumor (nADC-T), normalized-CBF-tumor (nCBF-T), normalized-CBV-tumor (nCBV-T), and normalized-CBF-edema (nCBF-E) between LGG and HGG, and when these metrics were combined, HGG could be distinguished from LGG with a sensitivity and specificity of 100%. The only metric to distinguish HGG from MET was the normalized-ADC-E with a sensitivity of 68.8% and a specificity of 80%. LGG can be distinguished from MET by combining edema volume (Vol-E), Vol-E/tumor volume (Vol-T), nADC-T, nCBF-T, nCBV-T, and nADC-E with a sensitivity of 93.3% and a specificity of 100%. The present study confirms the usability of a multibiometric approach including volume, perfusion, and diffusion metrics in differentially diagnosing brain tumors in preoperative patients and adds to the growing body of evidence in the clinical field in need of validation and standardization.
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| 5. |
- Edvardsson, Anneli, et al.
(författare)
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Comparative treatment planning study for mediastinal Hodgkin’s lymphoma : impact on normal tissue dose using deep inspiration breath hold proton and photon therapy
- 2019
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Ingår i: Acta Oncologica. - 0284-186X. ; 58:1, s. 95-104
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Tidskriftsartikel (refereegranskat)abstract
- Background: Late effects induced by radiotherapy (RT) are of great concern for mediastinal Hodgkin’s lymphoma (HL) patients and it is therefore important to reduce normal tissue dose. The aim of this study was to investigate the impact on the normal tissue dose and target coverage, using various combinations of intensity modulated proton therapy (IMPT), volumetric modulated arc therapy (VMAT) and 3-dimensional conformal RT (3D-CRT), planned in both deep inspiration breath hold (DIBH) and free breathing (FB). Material and methods: Eighteen patients were enrolled in this study and planned with involved site RT. Two computed tomography images were acquired for each patient, one during DIBH and one during FB. Six treatment plans were created for each patient; 3D-CRT in FB, 3D-CRT in DIBH, VMAT in FB, VMAT in DIBH, IMPT in FB and IMPT in DIBH. Dosimetric impact on the heart, left anterior descending (LAD) coronary artery, lungs, female breasts, target coverage, and also conformity index and integral dose (ID), was compared between the different treatment techniques. Results: The use of DIBH significantly reduced the lung dose for all three treatment techniques, however, no significant difference in the dose to the female breasts was observed. Regarding the heart and LAD doses, large individual variations were observed. For VMAT, the mean heart and LAD doses were significantly reduced using DIBH, but no significant difference was observed for 3D-CRT and IMPT. Both IMPT and VMAT resulted in improved target coverage and more conform dose distributions compared to 3D-CRT. IMPT generally showed the lowest organs at risk (OAR) doses and significantly reduced the ID compared to both 3D-CRT and VMAT. Conclusions: The majority of patients benefited from treatment in DIBH, however, the impact on the normal tissue dose was highly individual and therefore comparative treatment planning is encouraged. The lowest OAR doses were generally observed for IMPT in combination with DIBH.
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| 6. |
- Gunnlaugsson, Adalsteinn, et al.
(författare)
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Target definition in radiotherapy of prostate cancer using magnetic resonance imaging only workflow
- 2019
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Ingår i: Physics and imaging in radiation oncology. - : Elsevier BV. - 2405-6316. ; 9, s. 89-91
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Tidskriftsartikel (refereegranskat)abstract
- In magnetic resonance (MR) only radiotherapy, the target delineation needs to be performed without computed tomography (CT). We investigated in thirteenpatients with prostate cancer, how the clinical target volume (CTV) was affected, when the target delineation procedure was changed from using both CT and MRimages to using MR images only. The mean volume of the CTVCT/MR was 61.0 cm3 as compared to 49.9 cm3 from MR-only based target delineation, corresponding toan average decrease of 18%. Our results show that CTVMR-only was consistently smaller than CTVCT/MR, which has to be taken into consideration before clinicalcommissioning of MR-only radiotherapy.
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| 7. |
- Haraldsson, André, et al.
(författare)
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A Helical tomotherapy as a robust low-dose treatment alternative for total skin irradiation
- 2019
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Ingår i: Journal of Applied Clinical Medical Physics. - : Wiley. - 1526-9914. ; 20:5, s. 44-54
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Tidskriftsartikel (refereegranskat)abstract
- Mycosis fungoides is a disease with manifestation of the skin that has traditionally been treated with electron therapy. In this paper, we present a method of treating the entire skin with megavoltage photons using helical tomotherapy (HT), verified through a phantom study and clinical dosimetric data from our first two treated patients. A whole body phantom was fitted with a wetsuit as bolus, and scanned with computer tomography. We accounted for variations in daily setup using virtual bolus in the treatment plan optimization. Positioning robustness was tested by moving the phantom, and recalculating the dose at different positions. Patient treatments were verified with in vivo film dosimetry and dose reconstruction from daily imaging. Reconstruction of the actual delivered dose to the patients showed similar target dose as the robustness test of the phantom shifted 10 mm in all directions, indicating an appropriate approximation of the anticipated setup variation. In vivo film measurements agreed well with the calculated dose confirming the choice of both virtual and physical bolus parameters. Despite the complexity of the treatment, HT was shown to be a robust and feasible technique for total skin irradiation. We believe that this technique can provide a viable option for Tomotherapy centers without electron beam capability.
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| 8. |
- Haraldsson, André, et al.
(författare)
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Implementing safe and robust Total Marrow Irradiation using Helical Tomotherapy – A practical guide
- 2019
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Ingår i: Physica Medica. - : Elsevier BV. - 1120-1797. ; 60, s. 162-167
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Tidskriftsartikel (refereegranskat)abstract
- Total Marrow Irradiation (TMI) with Helical Tomotherapy is a radiotherapy treatment technique that targets bone marrow and sanctuary sites prior to stem cell or bone marrow transplantation (SCT/BMT). TMI is a complex procedure that involves several critical steps that all need to be carefully addressed for a successful implementation, such as dose homogeneity in field junctions, choice of target margins, integrity of treatment and back-up planning. In this work we present our solution for a robust and reproducible workflow throughout the treatment chain and data for twenty-three patients treated to date. Material & Methods: Patients were immobilized in a whole body vacuum cushion and thermoplastic mask. CT-scanning and treatment were performed in two parts with field matching at the upper thigh. Target consisted of marrow containing bone and sanctuary sites. Lungs, kidneys, bowel, heart and liver were defined as organs at risk (OAR). A fast surface scanning system was used to position parts of the body not covered by the imaging system (MVCT) as well as to reduce treatment time. Results: All patients completed their treatment and could proceed with SCT/BMT. Doses to OARs were significantly reduced and target dose homogeneity was improved compared to TBI. Robustness tests performed on field matching and patient positioning support that the field junction technique is adequate. Replacing MVCT with optical surface scanning reduced the treatment time by 25 min per fraction. Conclusion: The methodology presented here has shown to provide a safe, robust and reproducible treatment for Total Marrow Irradiation using Tomotherapy.
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| 9. |
- Haraldsson, André, et al.
(författare)
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Organ sparing total marrow irradiation compared to total body irradiation prior to allogeneic stem cell transplantation
- 2021
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 107:4, s. 393-407
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Total body irradiation (TBI) is commonly used prior to hematopoietic stem cell transplantation (HSCT) in myeloablative conditioning regimens. However, TBI may be replaced by total marrow irradiation (TMI) at centres with access to Helical TomoTherapy, a modality that has the advantage of delivering intensity-modulated radiotherapy to long targets such as the entire bone marrow compartment. Toxicity after organ sparing TMI prior to HSCT has not previously been reported compared to TBI or with regard to engraftment data. Methods: We conducted a prospective observational study on 37 patients that received organ sparing TMI prior to HSCT and compared this cohort to retrospective data on 33 patients that received TBI prior to HSCT. Results: The 1-year graft-versus-host disease-free, relapse-free survival (GRFS) was 67.5% for all patients treated with TMI and 80.5% for patients with matched unrelated donor and treated with TMI, which was a significant difference from historical data on TBI patients with a hazard ratio of 0.45 (P =.03) and 0.24 (P <.01). Engraftment with a platelet count over 20 [K/µL] and 50 [K/µL] was significantly shorter for the TMI group, and neutrophil recovery was satisfactory in both treatment cohorts. There was generally a low occurrence of other treatment-related toxicities. Conclusions: Despite small cohorts, some significant differences were found; TMI as part of the myeloablative conditioning yields a high 1-year GRFS, fast and robust engraftment, and low occurrence of acute toxicity.
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| 10. |
- Haraldsson, André, et al.
(författare)
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Surface-guided tomotherapy improves positioning and reduces treatment time : A retrospective analysis of 16 835 treatment fractions
- 2020
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Ingår i: Journal of Applied Clinical Medical Physics. - : Wiley. - 1526-9914. ; 21:8, s. 139-148
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: In this study, we have quantified the setup deviation and time gain when using fast surface scanning for daily setup/positioning with weekly megavoltage computed tomography (MVCT) and compared it to daily MVCT. Methods: A total of 16 835 treatment fractions were analyzed, treated, and positioned using our TomoTherapy HD (Accuray Inc., Madison, USA) installed with a Sentinel optical surface scanning system (C-RAD Positioning AB, Uppsala, Sweden). Patients were positioned using in-room lasers, surface scanning and MVCT for the first three fractions. For the remaining fractions, in-room laser was used for setup followed by daily surface scanning with MVCT once weekly. The three-dimensional (3D) setup correction for surface scanning was evaluated from the registration between MVCT and the planning CT. The setup correction vector for the in-room lasers was assessed from the surface scanning and the MVCT to planning CT registration. The imaging time was evaluated as the time from imaging start to beam-on. Results: We analyzed 894 TomoTherapy treatment plans from 2012 to 2018. Of all the treatment fractions performed with surface scanning, 90 % of the residual errors were within 2.3 mm for CNS (N = 284), 2.9 mm for H&N (N = 254), 8.7 mm for thorax (N = 144) and 10.9 for abdomen (N = 134) patients. The difference in residual error between surface scanning and positioning with in-room lasers was significant (P < 0.005) for all sites. The imaging time was assessed as total imaging time per treatment plan, modality, and treatment site and found that surface scanning significantly reduced patient on-couch time compared to MVCT for all treatment sites (P < 0.005). Conclusions: The results indicate that daily surface scanning with weekly MVCT can be used with the current target margins for H&N, CNS, and thorax, with reduced imaging time.
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