Outcomes Associated with Three Treatment Schedules of High-Dose-Rate Brachytherapy Monotherapy for Favorable-Risk Prostate Cancer
Menée sur 494 patients atteints d'un cancer de la prostate de stade T2b ou inférieur (durée globale médiane de suivi : 4 ans), cette étude évalue la toxicité de trois protocoles de curiethérapie à haut débit de dose en traitement unique
Purpose : We report outcomes associated with 3 high-dose-rate (HDR) brachytherapy regimens used as monotherapy for favorable-risk prostate cancer. Materials and Methods : 494 patients with stage ≤T2b, Gleason ≤7, and PSA ≤15 ng/mL underwent HDR brachytherapy as monotherapy. 319 received 38Gy/4 fractions, 79 received 24Gy/2 fractions, and 96 received 27Gy/2 fractions. Acute and chronic genitourinary (GU) and gastrointestinal (GI) toxicities were defined as side effects occurring ≤6 and >6 months post-RT, respectively, and graded according to CTCAEv3.0. Time to toxicity was calculated from the date of RT completion. Variables were analyzed using
χ2. P-values <0.05 were considered significant. Results
:
Median overall follow-up was 4 years (5.5/3.5/2.5 years for 38Gy/24Gy/27Gy, p<0.001). Acute and chronic grade
≥2 GU and GI toxicity profiles were similar among groups. Acceptable rates of grade 2 GU toxicities were seen with overall acute/chronic frequency/urgency, dysuria, retention, incontinence, and hematuria rates of 14%/20%, 6%/7%, 7%/4%, 1.5%/2%, and 1.5%/7%, respectively. Minimal grade 3 and no grade 4/5 toxicities were seen. Grade 1/2/3 chronic urethral stricture rates were 0.3%/2%/1%. All GI toxicities were similar between groups, with overall rates of acute/chronic grade 2 diarrhea, rectal pain/tenesmus, rectal bleeding, and proctitis of 1%/1%, <1%/0.5%, 0%/2%, and <1%/1%, respectively. No grade 3/4/5 toxicities were seen. All comparisons were similar for hormone-naïve patients. Median time to maximal GU/GI toxicity was similar between groups, ranging from 1-1.6/0.9-1.2 years, respectively. There were no differences in clinical outcomes between the 3 groups at 5 years. Conclusions : The acute and chronic toxicity profiles associated with these 3 HDR brachytherapy schedules were similar and well-tolerated. Acceptable grade 2, minimal grade 3, and no grade 4/5 toxicities were seen. This, combined with the fact that clinical outcomes were similar, leads to the conclusion that all 3 regimens may be acceptable options for the management of low-intermediate risk prostate cancer.
http://www.redjournal.org/article/S0360-3016%2815%2926576-5/abstract