Whole-gland salvage treatment for recurrent prostate cancer after initial definitive radiotherapy: A case series of 125I brachytherapy and robot-assisted radical prostatectomy

Purpose
To analyze outcomes following whole-gland salvage treatments applied to patients with pathology-proven, locally recurrent prostate cancer following primary definitive radiotherapy.

Material and methods
Eighteen consecutive patients who received whole-gland salvage treatments at our institution were retrospectively reviewed. All patients underwent transperineal template-guided mapping biopsy (TTMB) using the standard iodine-125 (125I) brachytherapy (BT) setup. Twelve patients received 125I BT, and six patients underwent robot-assisted laparoscopic prostatectomy (RARP). Prostate-specific antigen (PSA) failure was determined using the Phoenix definition (nadir + 2 ng/ml) following BT and a PSA level of > 0.2 ng/ml following RARP. Toxicities were graded according to CTCAE version 4.0.

Results
The median follow-up times were 71 and 11 months for the BT and RARP groups, respectively. In the BT group, the median dose to 90% of the prostate was 131 Gy. The median time to biochemical failure was 47 months, and the biochemical relapse-free survival (BRFS) rates were 56% (95% confidence interval [CI]: 33-94%) and 46% (95% CI: 25-88%) at 3 years and 5 years, respectively. Four patients (33%) developed grade 2 genitourinary (GU) toxicity, and two (17%) developed grade 3 GU toxicity. No patients developed grade ≥ 2 gastrointestinal (GI) toxicity. In the RARP group, three out of six patients (50%) had PSA failure, and four patients (67%) developed grade 2 GU toxicity. No patients developed grade 3 GU toxicity or grade ≥ 2 GI toxicity. On pre-salvage magnetic resonance imaging (MRI), no patients were suspected of having T3 or higher stage lesions. However, three patients (50%) had pT3a and two patients (33%) had pT3b (i.e., seminal vesicle invasion) stage lesions.

Conclusions
Whole-gland salvage BT is an effective treatment with an acceptable toxicity profile. The pathology findings from RARP imply that there is a room for improvement in diagnoses made by MRI in the pre-salvage setting.