The dose-volume histogram-based evaluation of predictors for gross hematuria after postprostatectomy radiotherapy.

[BACKGROUND] Gross hematuria following postprostatectomy radiotherapy (PPRT) is common and usually self-limited but could require hospitalization with surgical intervention in severe cases. In the present study, we have evaluated the prevalence and predictors associated with gross hematuria after PPRT.

[MATERIALS AND METHODS] From November 2003 to December 2017, 433 patients underwent radiotherapy after radical prostatectomy for prostate cancer. The Kaplan-Meier survival analysis was utilized to estimate the incidence of gross hematuria following PPRT, and the multivariable Cox regression analysis was performed to assess significant risk factors.

[RESULTS] In our cohort, a total of 124 patients (28.6%) experienced gross hematuria after PPRT within a median follow-up time of 104 months. Among them, 20 patients (16.1%) required transurethral fulguration. The estimated 10-year gross hematuria-free survival rate was 67.7%. The multivariable Cox regression analysis demonstrated that treatment history of anticoagulant/antiplatelet agent [hazard ratio (HR): 1.76, = 0.019), an absolute bladder V40 Gy ≥median (HR: 1.63, = 0.047), and a relative bladder V65 Gy ≥median (HR: 1.82, = 0.019) were associated with gross hematuria following PPRT.

[CONCLUSION] Our results suggest that gross hematuria after PPRT occurs frequently, especially among patients on anticoagulant/antiplatelet therapy and those with an absolute bladder V40 Gy ≥median and relative bladder V65 Gy ≥median during PPRT. Although most cases of gross hematuria were self-resolved, up to 16.1% required invasive surgical intervention. Limiting PPRT dose exposure to the bladder may also reduce the incidence of gross hematuria.