Permanent 125I prostate brachytherapy outcome in patients younger than 60

Abstract

14553 Background: Permanent 125I prostate brachytherapy (PB) has been shown to be an effective form of treatment for men with clinically localized prostate cancer. However, the efficacy of PB in younger men is not well established, and many urologists and oncologists have been reluctant to recommend PB to younger men, since most reported PB outcome has been based on men implanted in their late 60s and 70s. Methods: Between 1/1/98 and 6/30/01, 100 consecutive men aged 49–59 (median 56) underwent PB. All had either low- or intermediate-risk disease. PB was performed without combined external beam irradiation or post-PB androgen deprivation. The prescribed radiation dose=144–145Gy, the median implant activity=38mCi, median prostate volume=36 ml. Mean day-30 post-PB CT-based implant dosimetry values were V100=94%; V150=60%; D90=160 Gy. The primary endpoint for this analysis was the 5-year biochemical no evidence of disease rate (bNED) defined by the ASTRO consensus definition. Secondary endpoints were disease-specific survival (DSS); freedom from salvage therapy (FSRx), and overall survival (OS). Median PSA followup was 59 months (maximum 93 months). Actuarial results were calculated using the Kaplan-Meier method. Results: The 5-year bNED rate was 92%. 8 patients developed biochemical failure, and 6 went on to salvage treatment with hormonal therapy. There were 2 biopsy-proven local recurrences: one in a patient with previously diagnosed bony metastases, and one with isolated seminal vesicle recurrence (prostate biopsies negative). 3 other patients with biochemical failure had negative re-biopsies at 24, 64, and 66 months post-PB. No patient received local salvage therapy. One patient died from a second malignancy (colon CA diagnosed after PB). The 5-year DSS rate = 100%; FSRx = 93%, and OS = 99%. There were 2 Grade 3 GU complications (urethral strictures) (2%) and one Grade 4 GU complication (TURP) (1%). There were no Grade 3 or 4 GI complications. Conclusions: PB is an effective treatment modality for men younger than 60, with 5 year results comparable to those reported with prostatectomy and external beam irradiation. Given that most men who fail PB do so within 5 years of the implant, there appears to be no compelling scientific reason to advise against PB in men younger than 60 solely based on their age. No significant financial relationships to disclose.