TY - JOUR AB - The aim of the present study was to examine the effect of the photon beam energy on the volumetric modulated arc therapy (VMAT) plan quality for prostate cancer and on the risk of secondary carcinogenesis. Separate VMAT plans with 6‑MV and 10‑MV photons were created for 11 low‑risk patients with prostate cancer. The prescribed tumor dose was 70 Gy delivered in 28 fractions. The normal tissue integral dose and parameters associated with planning target volume and organs at risk were determined by the treatment planning data. A non‑linear mechanistic model considering the effects of tumor dose fractionation and cell proliferation was employed for estimating the patient‑specific lifetime attributable risk (LAR) for bladder and rectal cancer induction. Data from differential dose‑volume histograms were used for these risk assessments. The mean values of the planning parameters from 6‑MV treatment plans differed by 0.2‑3.4% from those associated with irradiation using 10‑MV photons. The LAR range for developing secondary bladder malignancies varied between 0.041 and 0.129% by the patient under investigation and the beam energy used. The corresponding range for the appearance of rectal malignant diseases was 0.047‑0.153%. The mean percentage difference between the bladder cancer risks from VMAT with 6‑MV and 10‑MV photons was 2.6±2.3%. The corresponding difference for secondary rectal malignancies was 0.7±0.6%. Therefore, VMAT for prostate cancer with both 6‑MV and 10‑MV photons leads to clinically equivalent treatment plans and to similar secondary bladder and rectal cancer risks. AD - Department of Medical Physics, Faculty of Medicine, University of Crete, 71003 Iraklion, Greece Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Greece AU - Mazonakis,Michalis AU - Kachris,Stefanos AU - Damilakis,John DA - 2021/05/01 DO - 10.3892/mco.2021.2251 IS - 5 JO - Mol Clin Oncol KW - prostate cancer volumetric modulated arc therapy beam energy treatment planning secondary carcinogenesis PY - 2021 SN - 2049-9450 2049-9469 SP - 89 ST - VMAT for prostate cancer with 6‑MV and 10‑MV photons: Impact of beam energy on treatment plan quality and model‑based secondary cancer risk estimates T2 - Molecular and Clinical Oncology TI - VMAT for prostate cancer with 6‑MV and 10‑MV photons: Impact of beam energy on treatment plan quality and model‑based secondary cancer risk estimates UR - https://doi.org/10.3892/mco.2021.2251 VL - 14 ER -