Five-year outcomes after iodine-125 seed brachytherapy for low-risk prostate cancer at three cancer centres in the UK

Abstract

Objective: To report the outcomes of >1000 men with low-risk prostate cancer treated with low-dose-rate (LDR) brachytherapy at three large UK cancer centres.

Patients and methods: A total of 1038 patients with low-risk prostate cancer (prostate-specific antigen [PSA] ≤10 ng/mL, Gleason score 6, ≤T2b disease) were treated with LDR iodine 125 (I-125) brachytherapy between 2002 and 2007. Patients were treated at three UK centres. PSA and clinical follow-up was performed at each centre. Biochemical recurrence-free survival was reported for the cohort.

Results: The median (range) PSA follow-up for the whole group was 5 years (4 months to 9 years). A total of 79 patients had biochemical failure, defined by a rise in PSA level: 16 patients fulfilled the ASTRO definition of biochemical failure, 25 patients fulfilled the Phoenix definition and 38 patients fulfilled both definitions. The 5-year biochemical relapse-free survival (bRFS) rate was 94.1% by the ASTRO definition and 94.2% by the Phoenix definition. The absence of neoadjuvant hormone therapy was predictive of inferior biochemical control as defined by the Phoenix definition (P = 0.033).

Conclusions: Our prospective multicentre series showed excellent bRFS with LDR I-125 brachytherapy for patients with low-risk prostate cancer. Further work is necessary to define the role of neoadjuvant androgen deprivation therapy in combination with brachytherapy.

Keywords: brachytherapy; low-risk; outcomes; prostate.