Long-term Outcomes of Radiation Therapy for Prostate Cancer in Elderly Patients Aged ≥75 Years

Background/Aim: This study aimed to evaluate the treatment outcomes of radiation therapy (RT) for localized prostate cancer in elderly patients aged >= 75 years. Patients and Methods: We retrospectively investigated data of patients aged >= 75 years with prostate cancer who underwent intensity -modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) with doses of 70-78 Gy in 35-39 fractions between September 2008 and June 2016. Overall survival (OS), recurrence-free (RF) rates, and occurrence rates of toxicities were calculated. Results: Eighty-eight patients were enrolled in the study. Nineteen patients died, and nine patients reported PSA failure within the follow-up period. The median follow-up time was 83.5 months. The median age was 77 years. In the cohort, 6 were low-risk, 36 were intermediate -risk, and 46 were high-risk patients. The 5-/7-year OS and RF rates were 87.9%/80.2% and 93.5%/89.1%, respectively. By risk, the 5-/7-year RF rates were 100%/80% in the low-, 100%/100% in the intermediate-, and 87.6%/82.7% in the high-risk groups, respectively. The cumulative incidence rates of Grade >= 3 genitourinary and gastrointestinal toxicities were 1.3% and 3.5% at 5 years and 3.3% and 3.5% at 7 years, respectively. Conclusion: IMRT and VMAT are effective treatment options for elderly patients with prostate cancer and in a good general condition.