Five‑fraction stereotactic body radiotherapy for prostate cancer in octogenarians and nonagenarians: A single‑institution retrospective cohort study

The incidence of prostate adenocarcinoma (PCa) increases with age.Stereotactic body radiotherapy (SBRT) is a curative option; however, the evidence in elderly patients remains limited.This single-institution retrospective cohort study included consecutive patients aged ≥80 years with localized PCa treated with definitive SBRT between May 2016 and June 2023.SBRT was delivered in five fractions with a total dose of 36.25-45.00Gy.A total of 118 patients with a median age of 82 years (range, 80-93 years) were included.Risk stratification identified three low-risk, 15 favorable intermediate-risk, 32 unfavorable intermediate-risk, 48 high-risk and 20 very high-risk patients.With a median follow-up of 47.7 months, there were seven deaths from any cause and nine biochemical recurrences, with no PCa-related deaths observed.The 3-and 5-year overall survival rates were 99.1 and 94.2%, respectively, whereas the 3-and 5-year biochemical progression-free survival rates were 94.5 and 83.2%, respectively.No acute genitourinary or gastrointestinal toxicities of grade 3 or higher were observed.Late grade 3 genitourinary and gastrointestinal toxicities were each observed in three patients, with no grade higher than 3 events.Definitive prostate SBRT achieved favorable survival outcomes with acceptable toxicity in carefully selected octogenarians and nonagenarians, supporting its feasibility as a curative-intent treatment option in this elderly population.