Patient-Reported Outcomes With Stereotactic Intensity Modulated Radiotherapy After Radical Prostatectomy: A...

Area of Science:

• Oncology
• Radiation Oncology
• Urology

Background:

• Postoperative radiotherapy is underutilized in men with biochemical recurrence or adverse pathological features after radical prostatectomy (RP).
• Stereotactic body radiotherapy (SBRT) offers potential radiobiological advantages and may improve utilization for post-RP treatment.

Purpose of the Study:

• To evaluate physician-reported late toxic effects following SBRT for men after RP.
• To assess 2-year patient-reported outcomes (PROs) after SBRT in the post-RP setting.

Main Methods:

• A phase 2, single-arm trial involving 100 men with post-RP prostate-specific antigen > 0.03 ng/mL or adverse pathologic features.
• SBRT was delivered at 30-34 Gy in 5 fractions to the prostate bed; nodal irradiation and hormonal therapy were optional.
• Late toxic effects were graded using CTCAE v4.03; PROs were measured using the Expanded Prostate Cancer Index-26 and compared to a conventionally fractionated radiotherapy (CFRT) cohort.

Main Results:

• The cumulative incidence of late grade 2/3 genitourinary toxic effects was 25%/4%, and gastrointestinal toxic effects was 3%/3%.
• At 2 years, 38.9% of patients had significant decrements in urinary incontinence PROs, 17.9% in urinary irritation, and 34.1% in bowel function.
• Compared to CFRT, SBRT showed no statistically significant difference in the odds of experiencing decrements >2-fold the MCID for urinary incontinence (aOR 1.55), urinary irritation (aOR 0.94), or bowel function (aOR 1.03).

Conclusions:

• Post-RP SBRT was well-tolerated in this nonrandomized trial.
• Patient-reported urinary and bowel function outcomes at 2 years were not measurably different compared to CFRT.
• Randomized trials and longer follow-up are necessary to fully define the toxic effects and efficacy of post-RP SBRT.