Intraprostatic Cancer Recurrence following Radical Radiotherapy on Transperineal Template Mapping Biopsy: Implications for Focal Ablative Salvage Therapy

Abstract

Purpose: Men in whom external beam radiotherapy fails are usually placed on delayed hormone therapy. Some of these men have localized recurrence that might be suitable for further local therapy. We describe patterns of recurrence and suitability for focal ablative therapy in those undergoing transperineal template prostate mapping biopsies.

Materials and methods: The study included 145 consecutive patients (December 2007 to May 2014) referred with suspicion of recurrence due to rising prostate specific antigen after external beam radiotherapy or brachytherapy who underwent transperineal template prostate mapping biopsies. Suitability for focal ablative therapy required the cancer to be unifocal or unilateral, or bilateral/multifocal with 1 dominant index lesion and secondary lesions with Gleason score 3+3=6 with no more than 3 mm cancer core involvement.

Results: Mean patient age was 70.7 (SD 5.8) years. Median prostate specific antigen at time of transperineal template prostate mapping biopsy was 4.5 ng/ml (IQR 2.5-7.7). Overall 75.9% (110) were suitable for a form of focal salvage treatment, 40.7% (59) were suitable for quadrant ablation, 14.5% (21) hemiablation, 14.5% (21) bilateral focal ablation and 6.2% (9) for index lesion ablation.

Conclusions: Three-quarters of patients who have localized radiorecurrent prostate cancer may be suitable for focal ablative therapy to the prostate based on transperineal template prostate mapping biopsies.

Keywords: biopsy; prostatic neoplasms; radiotherapy; salvage therapy.