CHARLOTTETOWN, Canada—Brachytherapy alone produces satisfactory biochemical control in men with clinically localized, intermediate-risk prostate cancer (PCa), a new study confirmed.
At the 65th annual meeting of the Canadian Urological Association, Darrel Drachenberg, MD, and his colleagues presented data showing that only one biochemical failure occurred in a series of 95 patients with biopsy-proven intermediate-risk PCa treated with brachytherapy. The cohort experienced 18 cases of urinary retention, two cases of urinary incontinence, four cases of erectile dysfunction, and one of rectal morbidity.
“There is an acceptable rate of treatment-related morbidity,” said Dr. Drachenberg, Assistant Professor of Urology at the University of Manitoba in Winnipeg. “Thus brachytherapy monotherapy seems to be a viable treatment modality without supplemental EBRT [external beam radiation therapy], and it is an alternative option to surgery or EBRT.”
His team is conducting ongoing follow-up to determine the long-term response to brachytherapy alone.
Only seven of the 95 patients had received androgen ablation to reduce prostate volume to less than 50 cc and none received supplemental EBRT. The brachytherapy dose was 145 Gy using iodine-125. The treatment margin was 3-5 mm outside of the capsule. Patients were followed up every three to four months with at least three post-operative PSA values and a symptom review at each follow-up visit. The mean follow-up time was 13.8 months. The patients’ median age was 68 years and 44 of them had a PSA level of 10 or higher but less than 20 ng/mL. Two had a Gleason score of 5, 21 had a Gleason score of 6, and the remainder had a Gleason score of 7.
Among the 57 patients with at least three consecutive PSA follow-ups, one patient experienced biochemical failure based on Phoenix criteria (nadir plus 2 ng/mL) and two experienced failure according to ASTRO criteria (three consecutive PSA rises above nadir). The PSA nadir of the 57 patients ranged from 0.01-2.86 ng/mL and their time to nadir ranged from 2-57 months.