Late urinary toxicity after prostate intensity-modulated radiation therapy for patients with history of invasive...

The aim of this study was to evaluate late genitourinary (GU) toxicities on receiving intensity-modulated radiation therapy (IMRT) in patients with prostate cancer (PCa) who had a history of invasive interventions for the prostate or bladder.

Among patients who received IMRT for PCa at our institution between August 2000 and December 2022, clinical outcomes among those with a history of invasive interventions for the prostate or bladder were retrospectively analyzed. Cumulative incidence rates of late ≥ grade 2 and ≥ grade 3 GU and gastrointestinal toxicities, and rates of overall survival (OS) and biochemical failure-free survival (BFFS) were evaluated.

A total of 32 consecutive patients were analyzed, among whom 28 received conventional fractionated IMRT with a median dose of 74 Gy in 37 fractions, and 4 underwent moderately hypo-fractionated IMRT with a median dose of 54 Gy in 15 fractions. The median follow-up period was 77.3 months after IMRT. Cumulative incidence rates of ≥ grade 2 and ≥ grade 3 GU toxicities were 20.7 and 4.3% at 5 years, and 26.4 and 4.3% at 8 years, respectively. More than 10 years after IMRT, 18.8% of patients developed ≥ grade 2 GU toxicities. OS and BFFS rates were 89.5 and 76.0% at 5 years, and 89.5 and 60.7% at 8 years, respectively.

Prostate IMRT for patients with a history of invasive interventions for the prostate or bladder was considered a safe and feasible treatment option, although the incidence of late GU toxicities was relatively high. Long-term follow-up with close attention to the detection of GU toxicities is recommended for such a population. Clinical outcomes of IMRT in 32 patients with prostate cancer and a history of invasive interventions for the prostate or bladder were retrospectively analyzed. Although the incidence of late genitourinary toxicities was relatively high, prostate IMRT was considered a safe and feasible treatment option for such a population.