Outcomes of High-Dose Rate (HDR) Brachytherapy in Intermediate- to High-Risk Prostate Cancer Patients with Prior Transurethral Resection of the Prostate (TURP)

Abstract

The purpose of this study was to evaluate the effect of prior TURP on genitourinary toxicity, sexual function, and biochemical-failure free survival (bFFS) in patients receiving HDR brachytherapy at a large volume academic center. Data was prospectively collected for patients undergoing HDR brachytherapy from August 2010 to December 2016. Patients were classified according to NCCN risk criteria. Patients with favorable intermediate-risk disease underwent HDR monotherapy alone and patients with unfavorable intermediate- to high- risk disease underwent a combination of IMRT and HDR brachytherapy boost. Implants were performed under ultrasound-guidance with CT based planning. Goal dosimetric constraints included V100 Prostate >95% and D1cc Urethra <105%. Univariate log rank test was used for treatment categorization to compare biochemical-failure free survival (bFFS). 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. 248 patients underwent HDR brachytherapy and were included in the analysis. 31 patients had prior TURP. The median follow-up was 47 months (range 3 – 83 months) and the median age was 71 (range 57 – 83). A total of 146 and 102 patients were intermediate- and high-risk, respectively, of which and 12 and 19 patients with TURP were intermediate- and high-risk, respectively. Median time from TURP to HDR was 18 months (range 3 – 146). 14 (45%) and 7(23%) patients with a history of TURP experienced Gr 1 and 2 GU toxicity. There were no patients that experienced Gr ≥3 GU toxicity. Patient reported GU and sexual function quality of life outcomes were not found to be statistically significant between prior TURP and non-TURP patients. One patient with a prior TURP experienced a biochemical recurrence. No significant difference was observed in biochemical-failure free survival between patients who did and did not receive a prior TURP (96±4% vs. 86±4%, respectively; p = 0.36). HDR brachytherapy is a safe and effective treatment for patients diagnosed with prostate cancer who received prior TURP.