High-Dose Rate (HDR) Brachytherapy is a Safe and Effective Treatment for Prostate Cancer Patients With Prior Transurethral Resection of the Prostate (TURP)

Abstract

To evaluate the clinical and patient-reported outcomes and toxicities in prostate cancer patients undergoing HDR brachytherapy after TURP.Data was prospectively collected for patients undergoing HDR brachytherapy from October 1991 to March 2016. Patients were classified according to NCCN risk criteria. Implants were performed under ultrasound-guidance with CT based planning. Goal dosimetric constraints included V100 Prostate > 95%, D1cc Urethra < 105%, D1cc Bladder < 75%, and D1cc Rectum < 75%. Multivariate cox analysis (MVA) was performed and adjusted for age, T stage, Gleason score, initial PSA, and androgen deprivation therapy (ADT) use. Sexual health inventory for men (SHIM) score, International Prostate Symptom Score (IPSS), and CTCAE v5.0 graded toxicity were recorded.2266 patients underwent HDR brachytherapy. 228 underwent a prior TURP. The median follow-up was 61.1 months (range 3 - 257.4 mos). The median time from TURP to HDR was 52.5 months (range 0.17 - 392 mos). A total of 641, 431, 617, and 577 patients were low-, favorable intermediate-, unfavorable intermediate-, and high-risk, respectively, of which 41, 49, 53, and 85 patients with TURP were low-, favorable intermediate-, unfavorable intermediate-, and high-risk, respectively. Patients with a prior history of TURP were more advanced in age and had a higher incidence of high-risk disease (P < 0.001). Of the patients with history of prior TURP, 49 (22%) and 54 (24%) patients experienced Gr 1 and 2 GU toxicity. 8 patients (3.5%) experienced grade 3 GU toxicity with a median time to occurrence of 16 mo (0.2 - 57.7 mo), and 3 of the Grade 3 toxicities resolved. No grade ≥4 GU toxicity and significant differences in toxicity were observed between the cohorts (P = 0.108). Patient-reported SHIM scores were found to not be statistically significant between prior TURP and non-TURP patients, with average decreases in SHIM no greater than 5 points at all time points in the TURP cohort. No significant differences were observed in biochemical free survival, distant metastases free survival, and prostate cancer specific survival at 4 and 8 years between patients who did and did not receive a prior TURP (8-yr BCFS 84.7% (95% CI: 78.2%-91.8%) vs. 89.1% (95% CI: 87.3-91.0%), respectively; P = 0.16). The TURP cohort was found to have lower overall survival (8-yr OS 72.0% (95% CI 64.8%-79.9%) vs. 81.9% (95% CI: 80.0% - 84.1%) respectively; P = 0.041), and may be attributed to the older age of the TURP cohort (P < 0.001).HDR brachytherapy is a safe and effective treatment modality with low toxicity for prostate cancer patients after a prior TURP.