| 1. |
- Bosco, Cecilia, et al.
(författare)
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Prostate Cancer Radiation Therapy and Risk of Thromboembolic Events
- 2017
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : ELSEVIER SCIENCE INC. - 0360-3016 .- 1879-355X. ; 97:5, s. 1026-1031
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the risk of thromboembolic disease (TED) after radiation therapy (RT) with curative intent for prostate cancer (PCa).Patients and Methods: We identified all men who received RT as curative treatment (n=9410) and grouped according to external beam RT (EBRT) or brachytherapy (BT). By comparing with an age-and county-matched comparison cohort of PCa-free men (n = 46,826), we investigated risk of TED after RT using Cox proportional hazard regression models. The model was adjusted for tumor characteristics, demographics, comorbidities, PCa treatments, and known risk factors of TED, such as recent surgery and disease progression.Results: Between 2006 and 2013, 6232 men with PCa received EBRT, and 3178 underwent BT. A statistically significant association was found between EBRT and BT and risk of pulmonary embolism in the crude analysis. However, upon adjusting for known TED risk factors these associations disappeared. No significant associations were found between BT or EBRT and deep venous thrombosis.Conclusion: Curative RT for prostate cancer using contemporary methodologies was not associated with an increased risk of TED.
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| 2. |
- Persson, Emilia, et al.
(författare)
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MR-OPERA : A Multicenter/Multivendor Validation of Magnetic Resonance Imaging-Only Prostate Treatment Planning Using Synthetic Computed Tomography Images
- 2017
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : ELSEVIER SCIENCE INC. - 0360-3016 .- 1879-355X. ; 99:3, s. 692-700
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To validate the dosimetric accuracy and clinical robustness of a commercially available software for magnetic resonance (MR) to synthetic computed tomography (sCT) conversion, in an MR imaginge-only workflow for 170 prostate cancer patients.Methods and Materials: The 4 participating centers had MriPlanner (Spectronic Medical), an atlas-based sCT generation software, installed as a cloud-based service. A T2-weighted MR sequence, covering the body contour, was added to the clinical protocol. The MR images were sent from the MR scanner workstation to theMriPlanner platform. The sCT was automatically returned to the treatment planning system. Four MR scanners and 2 magnetic field strengths were included in the study. For each patient, a CT-treatment plan was created and approved according to clinical practice. The sCT was rigidly registered to the CT, and the clinical treatment plan was recalculated on the sCT. The dose distributions from the CT plan and the sCT plan were compared according to a set of dose-volume histogram parameters and gamma evaluation. Treatment techniques included volumetric modulated arc therapy, intensity modulated radiation therapy, and conventional treatment using 2 treatment planning systems and different dose calculation algorithms.Results: The overall (multicenter/multivendor) mean dose differences between sCT and CT dose distributions were below 0.3% for all evaluated organs and targets. Gamma evaluation showed a mean pass rate of 99.12% (0.63%, 1 SD) in the complete body volume and 99.97% (0.13%, 1 SD) in the planning target volume using a 2%/ 2-mm global gamma criteria.Conclusions: Results of the study show that the sCT conversion method can be used clinically, with minimal differences between sCT and CT dose distributions for target and relevant organs at risk. The small differences seen are consistent between centers, indicating that an MR imagingeonly workflow using MriPlanner is robust for a variety of field strengths, vendors, and treatment techniques.
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| 3. |
- Rasmusson, Elisabeth, et al.
(författare)
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Erectile Dysfunction and Absorbed Dose to Penile Base Structures in a Randomized Trial Comparing Ultrahypofractionated and Conventionally Fractionated Radiation Therapy for Prostate Cancer
- 2020
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier. - 0360-3016 .- 1879-355X. ; 107:1, s. 143-151
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To study the relationships between absorbed dose to penile base structures and erectile dysfunction (ED) in patients treated with ultrahypofractionated (UHF) radiation therapy (RT) or conventionally fractionated (CF) RT for prostate cancer.Methods and Materials: This dose-response study comprises 673 patients (57%) of the 1180 per-protocol patients included in the HYPO-RT-PC trial (median follow-up 5, years), where patients were randomized to CF (39 × 2.0 Gy, 8 weeks) or UHF (7 × 6.1 Gy, 2.5 weeks). No androgen deprivation therapy was allowed. Only patients with erectile function sufficient for intercourse at baseline and complete RT data were included in this study. Erectile function was assessed by physician at regular follow-ups. The main endpoint was severe ED (EDs). The penile bulb (PB) and crus were retrospectively delineated on the treatment planning computed tomography scans. Dose-volume descriptors were derived from EQD2 converted dose matrices (α/β = 3 Gy). Univariable and multivariable Cox proportional hazard regression and logistic regression were used to find predictors for EDS.Results: No significant difference in EDs was found between CF and UHF. During the follow-up period, EDs occurred in 27% of the patients in both treatment groups. Average (median) PB mean dose, Dmean, was 24.5 (20.2) in CF and 18.7 (13.1) Gy3 in UHF. Age was the only significant predictor for EDs in Cox analyses. All dose-volume variables contributed significantly in univariable logistic regression at 2-year follow-up. Age and near maximum dose (D2%) were significant predictors for EDs in multivariable logistic regression analyses at both 1 and 2 years.Conclusions: The frequency of EDS was similar in the CF and UHF treatment groups. Age at radiation therapy was the strongest predictor for EDs, followed by dose to PB, and was most evident for younger patients. We propose D2 % <50 Gy3 and Dmean <20 Gy3 to the PB as the primary objectives to be applied in the treatment planning process.
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