Safety and Efficacy of Salvage High-Dose Rate Brachytherapy for Prostate-Bed Recurrences Following Radical Prostatectomy and External Beam Radiotherapy

This retrospective study aims to evaluate the efficacy and safety of salvage HDR brachytherapy in second local recurrences of prostate cancer after applying radical prostatectomy (RP) and post-operative external beam radiotherapy (EBRT). Fifteen patients with locally recurrent prostate cancer after RP and EBRT were salvaged with HDR brachytherapy. Patients had no nodal or distant metastasis evidence on imaging findings, including whole body bone scan, CT scan, and MRI or PSMA PET scan. HDR brachytherapy was applied with 36 Gy in four fractions, in two implantations with 1 week apart. We followed the patients for a control visit every 3 months for 2 years, and every 6 months thereafter. Fifteen patients with the mean age of 64 years (ranged 51–79) underwent salvage HDR brachytherapy. The mean baseline level of PSA was calculated 2.26 ng/ml (ranged from 0.21 to 9, SD = 2.33), which has been significantly decreased in all patients. Hence, two of our patients experienced a biochemical failure during the follow-up period. Our results showed that 86.6% (n = 13) of patients had never experienced a significant increment in PSA level after a median follow-up of 48 months (ranging from 12 to 132 months). Besides, salvage HDR brachytherapy did not induce any significant side effects such as acute or late rectal complications, despite causing urinary complication. HDR brachytherapy could be considered as a treatment in well-selected patients with the second recurrence in their prostatic bed after the former EBRT allowing for dose escalating to the second nodular recurrence.