Salvage brachytherapy for local recurrence after radical prostatectomy and subsequent external beam radiotherapy

To evaluate the technical feasibility, safety, and efficacy of seed implantation for local recurrence after radical prostatectomy and external beam radiotherapy.

Between October 1999 and March 2002, 10 patients with targeted, histologically proven local relapse after surgery and subsequent external beam radiotherapy (only in 8 patients), underwent permanent brachytherapy with palladium-103 and iodine-125 after complete restaging. In all patients, an intraoperative morphovolumetric ultrasound study of the target was performed, with a planning target volume ranging from 5 to 26.7 cm(3). The preimplant prostate-specific antigen values ranged from 1.1 to 6.31 ng/mL.

Postplan dosimetry was performed to determine the percentage of the target volume that received a dose equal to, or greater than, the prescribed dose (range 84.5% to 95.9%) and the dose that was delivered to the 90% of the target volume (range 85.08% to 129.43%). The urinary scores, measured using the International Prostate Symptom Score, had normalized at 3 months. Only 1 patient had worsened incontinence during the first 2 months, with subsequent restoration of the previous situation. The other patients did not have any changes in their previous clinical condition. One patient experienced occasional gross hematuria that had been present after external beam radiotherapy. No rectal complications were reported. After a median follow-up of 20.6 months, 7 patients showed a decreasing or stable prostate-specific antigen level.

This preliminary experience has demonstrated that seed implantation of a neoplastic local recurrence is technically feasible and safe and allows for accurate dosimetry when the area to be treated can be defined by ultrasonography. Longer follow-up, accurate patient selection, and larger series of patients could help to better define the oncologic outcome.