TY - JOUR A1 - Tamihardja, Jörg A1 - Razinskas, Gary A1 - Exner, Florian A1 - Richter, Anne A1 - Kessler, Patrick A1 - Weick, Stefan A1 - Kraft, Johannes A1 - Mantel, Frederick A1 - Flentje, Michael A1 - Polat, Bülent T1 - Comparison of treatment plans for hypofractionated high-dose prostate cancer radiotherapy using the Varian Halcyon and the Elekta Synergy platforms JF - Journal of Applied Clinical Medical Physics N2 - Purpose To compare radiotherapy plans between an O-ring and a conventional C-arm linac for hypofractionated high-dose prostate radiotherapy in terms of plan quality, dose distribution, and quality assurance in a multi-vendor environment. Methods Twenty prostate cancer treatment plans were irradiated on the O-ring Varian Halcyon linac and were re-optimized for the C-arm Elekta Synergy Agility linac. Dose-volume histogram metrics for target coverage and organ at risk dose, quality assurance, and monitor units were retrospectively compared. Patient-specific quality assurance with ion chamber measurements, gamma index analysis, and portal dosimetry was performed using the Varian Portal Dosimetry system and the ArcCHECK® phantom (Sun Nuclear Corporation). Prostate-only radiotherapy was delivered with simultaneous integrated boost (SIB) volumetric modulated arc therapy (VMAT) in 20 fractions of 2.5/3.0 Gy each. Results For both linacs, target coverage was excellent and plan quality comparable. Homogeneity in PTVBoost was high for Synergy as well as Halcyon with a mean homogeneity index of 0.07 ± 0.01 and 0.05 ± 0.01, respectively. Mean dose for the organs at risk rectum and bladder differed not significantly between the linacs but were higher for the femoral heads and penile bulb for Halcyon. Quality assurance showed no significant differences in terms of ArcCHECK gamma pass rates. Median pass rate for 3%/2 mm was 99.3% (96.7 to 99.8%) for Synergy and 99.8% (95.6 to 100%) for Halcyon. Agreement between calculated and measured dose was high with a median deviation of −0.6% (−1.7 to 0.8%) for Synergy and 0.2% (−0.6 to 2.3%) for Halcyon. Monitor units were higher for the Halcyon by approximately 20% (p < 0.001). Conclusion Hypofractionated high-dose prostate cancer SIB VMAT on the Halcyon system is feasible with comparable plan quality in reference to a standard C-arm Elekta Synergy linac. KW - acute toxicity KW - dose evaluation KW - Halcyon KW - hypofractionation KW - prostate cancer KW - Synergy Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260722 VL - 22 IS - 9 ER - TY - JOUR A1 - Mantel, Frederick A1 - Müller, Elena A1 - Kleine, Philip A1 - Zimmermann, Marcus A1 - Exner, Florian A1 - Richter, Anne A1 - Weick, Stefan A1 - Ströhle, Serge A1 - Polat, Bülent A1 - Höcht, Stefan A1 - Flentje, Michael T1 - Chemoradiotherapy by intensity-modulated radiation therapy with simultaneous integrated boost in locally advanced or oligometastatic non-small-cell lung cancer-a two center experience JF - Strahlentherapie und Onkologie N2 - Purpose Integrating moderate hypofractionation to the macroscopic tumor with elective nodal irradiation while sparing the organs at risk (OAR) in chemoradiotherapy of locally advanced non-small-cell lung cancer. Methods From 2010-2018, treatment, patient and tumor characteristics of 138 patients from two radiation therapy centers were assessed. Chemoradiotherapy by intensity-modulated radiation therapy (IMRT) with a simultaneous integrated boost (SIB) to the primary tumor and macroscopic lymph node metastases was used. Results A total of 124 (90%) patients received concurrent chemotherapy. 106 (76%) patients had UICC (Union for International Cancer Control) stage ≥IIIB and 21 (15%) patients had an oligometastatic disease (UICC stage IV). Median SIB and elective total dose was 61.6 and 50.4 Gy in 28 fractions, respectively. Furthermore, 64 patients (46%) had an additional sequential boost to the primary tumor after the SIB-IMRT main series: median 6.6 Gy in median 3 fractions. The median cumulative mean lung dose was 15.6 Gy (range 6.2-29.5 Gy). Median follow-up and radiological follow-up for all patients was 18.0 months (range 0.6-86.9) and 16.0 months (range 0.2-86.9), respectively. Actuarial local control rates at 1, 2 and 3 years were 80.4, 68.4 and 57.8%. Median overall survival and progression-free survival was 30.0 months (95% confidence interval [CI] 23.5-36.4) and 12.1 months (95% CI 8.2-16.0), respectively. Treatment-related toxicity was moderate. Radiation-induced pneumonitis grade 2 and grade 3 occurred in 13 (9.8%) and 3 (2.3%) patients. Conclusions Chemoradiotherapy using SIB-IMRT showed promising local tumor control rates and acceptable toxicity in patients with locally advanced and in part oligometastatic lung cancer. The SIB concept, resulting in a relatively low mean lung dose, was associated with low numbers of clinically relevant pneumonitis. The overall survival appears promising in the presence of a majority of patients with UICC stage ≥IIIB disease. KW - local control KW - image-guided radiation therapy KW - thoracic cancer KW - hypofractionation KW - multimodal therapy Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264821 SN - 1439-099X VL - 197 IS - 5 ER -