Permanent brachytherapy as salvage treatment for recurrent prostate cancer

To determine the prostate-specific antigen (PSA)-based freedom from second failure, survival, and morbidity of permanent brachytherapy as salvage treatment for men for whom primary external beam irradiation of prostate cancer failed.

A retrospective review was performed on 17 consecutive men seen and treated with permanent brachytherapy for recurrent adenocarcinoma of the prostate from February 1989 to May 1994. Patients had been treated with a median of 63.3 Gy and presented with progressive local disease 23 to 146 months later (median 54). After a staging evaluation documenting no distant disease, all received permanent implantation of iodine-125 for 120 Gy (15 patients) or palladium-103 for 90 Gy (2 patients) using a transperineal ultrasound-guided technique. All doses were calculated before TG-43. Progression after brachytherapy was defined according to the ASTRO Consensus Conference definition. All results are reported as Kaplan-Meier actuarial 5-year results.

The 5-year actuarial freedom from second relapse was 53%. Both PSA and Gleason score appear to be prognostic factors, although both failed to reach statistical significance. Patients with a PSA 10 ng/mL or less at the time of salvage therapy had a freedom from second relapse rate of 67% compared with 25% for men with a PSA greater than 10 ng/mL (P = 0. 15). Those with low-grade tumor at the time of salvage therapy had an 83% freedom from second relapse rate compared with 30% for those with high-grade cancer (P = 0. 12). With 93% alive at 5 years, no significant difference was seen in survival on the basis of these prognostic groups. Acute and transient toxicity were readily managed and indistinguishable from that reported for previously unirradiated patients. Long-term complications were limited to a 24% risk of incontinence at 5 years.

Ultrasound-guided transperineal brachytherapy is an effective second-line therapy for patients for whom external beam irradiation has failed. Early intervention may be valuable when the PSA is less than 10 ng/mL. The risk of incontinence is significant, and patients must be individually counseled.