CHICAGO—Brachytherapy is a potentially effective salvage option for men with locally recurrent disease following external beam radiation therapy for prostate cancer, according to researchers.
“If you have had external beam radiotherapy and failed, there is hope,” said lead investigator Jamie Cesaretti, MD, a radiation oncologist and brachytherapist at Riverside Cancer Center in Jacksonville, Fla. “The key is to act early.”
He and his collaborators demonstrated good long-term results and minimal toxicity in androgen-sensitive patients, men with a re-biopsy Gleason score of 7 or less, and those with pre-salvage PSA levels of 7 ng/mL or less.
The researchers, who reported their findings here at the American Society of Therapeutic Radiation and Oncology’s 51st Annual Meeting, studied 60 men who underwent salvage brachytherapy with Pd-103 seeds after failing external radiation treatment with intensity-modulated radiation therapy, 3D conformal radiation therapy, or image-guided radiation therapy.
All had biopsy-proven disease and negative findings on CT and bone scans. At the time of salvage therapy, 11 men had androgen-independent localized disease.
All 60 men were treated with a real-time intraoperative dosimetry technique using a prescription dose of 100 Gy to the prostate. In addition, 98% of the patients received hormone therapy for a median of six months. The researchers followed patients for clinical and biochemical recurrence. In addition, serial PSA levels were obtained and treatment-related toxicities were recorded according to the Radiation Therapy Oncology Group late toxicity scale.
The median follow-up from the time of implant was 46 months (range 12-130 months). Overall, 54% of men were free from biochemical relapse at five years and 44% of men were free from biochemical relapse at seven years.
At seven years, 89% of men with a Gleason score of 7 or less at re-biopsy, pre-salvage PSA levels of 7 or less, or hormone-sensitive disease were free from biochemical relapse. The proportion was only 33% for men with a Gleason score greater than 7, a PSA level above 7, or androgen-independent disease.
The researchers observed no major adverse effects of treatment. The main problems were frequent urination and burning with urination that lasted for a few months, the investigators noted. Five patients required transurethral resection of the prostate.