Late Urinary Toxicity After Extreme or Moderate Hypofractionated Prostate Radiation Therapy in Patients With Prior Transurethral Resection of Prostate.

PURPOSE: To study the late urinary toxicity in patients with prostate cancer with prior transurethral resection of prostate (TURP) and treated with hypofractionated prostate radiation therapy. METHODS AND MATERIALS: Patients diagnosed with prostate cancer, with a prior TURP, and treated with moderate or extreme hypofractionated intensity-modulated radiation therapy (moderate hypofractionated radiation therapy [MHRT], stereotactic body radiation therapy [SBRT]), were included in this study. Severity and duration of urinary symptoms observed during serial follow-up after at least 3 months from radiation therapy were graded per National Cancer Institute Common Terminology Criteria for Adverse Events v5.0 using information from a prospectively maintained institutional database. Impact of hypofractionation and other potential contributory factors on cumulative grade 2+ late urinary toxicity was analyzed with univariable and multivariable binary logistic regression. RESULTS: A total of 203 eligible patients were included (MHRT = 114, 64-68 Gy/25#; SBRT = 89, 35-37.5 Gy/5#). Median time from TURP to radiation therapy was 10 months (IQR, 7-16 months), similar for MHRT and SBRT. Overall, mean cavity volume was 1.17 cc (IQR, 0.5-1.35 cc), whereas in MHRT and SBRT groups it was 1.03 cc (IQR, 0.4-1.15 cc) and 1.27 cc (IQR, 0.5-1.4 cc), respectively. At a median follow-up of 37 months, cumulative grade 3 and grade 2 late urinary toxicity was 8.4% (n = 17) and 23.2% (n = 47), respectively. Grade 3 symptoms were observed at median 29 months (IQR, 19-62 months) after radiation therapy completion, lasting for a median duration of 8 months (IQR, 2-14 months). Hematuria (6.4%) and urinary obstruction (3.4%) were the chief grade 3 symptoms. Multivariable analysis for age, diabetes, pelvic radiation therapy, fraction size, prostate volume, TURP to radiation therapy duration, and TURP cavity volume showed no significant association with late grade 2+ urinary toxicity. CONCLUSIONS: In this large cohort of patients with prior TURP and treated with hypofractionated prostate radiation therapy, incidence of severe late urinary adverse effects was <10%, mainly hematuria or urinary obstruction. Most of these were temporary, and no significant contributory factors were identified for late urinary morbidity after TURP and radiation therapy.

Acute and Late Adverse Effects of Prostate-Only or Pelvic Stereotactic Radiation Therapy in Prostate Cancer: A Comparative Study.

PURPOSE: To compare the urinary and gastrointestinal adverse effects with or without the inclusion of pelvic nodal regions in patients treated with extreme hypofractionated stereotactic radiation therapy (SBRT) for prostate cancer. METHODS AND MATERIALS: Patients treated with definitive SBRT for nonmetastatic adenocarcinoma prostate were identified from prospectively maintained institutional database, and details of radiation therapy volume, dose, acute, and late adverse effects were analyzed. Symptoms of acute (within 90 days of completing SBRT) and late gastrointestinal and urinary toxic effects were graded using Common Terminology Criteria for Adverse Effects version 5.0. Each symptom was scored according to the worst reported grading during treatment and the follow-up period. Cumulative rates of adverse effects between prostate-only SBRT (PO-SBRT) and whole pelvic SBRT (WP-SBRT) were compared using the χ2 test. Univariable and multivariable analysis was performed for possible factors affecting acute gastrointestinal and late urinary toxic effects. RESULTS: A total of 220 patients were analyzed (PO-SBRT = 118, WP-SBRT = 102), with a median follow-up of 28 months (interquartile range, 14-40). Most patients had locally advanced disease (PO-SBRT 60% high risk and 40% intermediate risk, WP-SBRT 79% node positive, and 21% high risk). The median SBRT dose was 36.25Gy (interquartile range, 35-36.25) to the prostate (2-Gy equivalent, EQD2 = 90.6Gy, a/b = 1.5Gy) and simultaneous integrated 25Gy to the pelvis (EQD2 = 46.3Gy) in 5 fractions on alternate days. No grade 3 to 4 acute adverse effects were observed except 1 grade 3 urinary obstruction (PO-SBRT). WP-SBRT was associated with a significantly higher rate of acute grade 2 gastrointestinal toxic effects (29.4% vs 14.7%, P = .008) and late grade 2 urinary adverse effects (45.6% vs 25.0%, P = .003). Both groups had low incidence of late grade 3 adverse effects (urinary 2.5%, gastrointestinal 1%). CONCLUSIONS: WP-SBRT was associated with significantly higher acute gastrointestinal and late urinary adverse effects compared with PO-SBRT, although overall incidence of severe adverse effects was low.