Biochemical disease-free survival rates following definitive low-dose-rate prostate brachytherapy with dose escalation to biologic target volumes identified with SPECT/CT capromab pendetide

PURPOSE: To report biochemical disease-free survival (bDFS) after conformal brachytherapy with dose escalation to biological target volumes (BTVs) identified by Capromab Pendetide with single photon emission computed tomography and computed tomography image fusion (SPECT/CT). METHODS AND MATERIALS: Two hundred thirty-nine (T1c-T3b NxM0) consecutive patients were evaluated by SPECT/CT before treatment. Intraprostatic SPECT/CT BTVs were identified and targeted for 150% dose escalation during brachytherapy seed implant (SI). Patients received either SI alone (n = 150) or external beam radiation therapy (EBRT) plus SI boost (EBRT + SI) (n = 89), with (n = 50) and without (n = 189) neoadjuvant hormone ablation therapy. Risk factors (RF) (prostate-specific antigen [PSA] > 10 ng/mL, Stage >= T2b, and Gleason grade >= 7) defined risk group (RG) categories [none, 1, and >= 2 RF define low, intermediate, and high RG] for bDFS calculations using four failure criteria: American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition, PSA > 1.0 ng/mL (PSA > 1), PSA > 0.5 ng/mL after nadir (PSA > 0.5), and PSA nadir + 2 ng/mL rise in PSA clinical nadir (CN + 2). Median followup was 47.2 months (range, 24.8-96.1). RESULTS: Seven-year actuarial bDFS rates were 88.0%, 82.1%, 80.4%, and 79.9% using the ASTRO, PSA > 1, PSA > 0.5, and CN + 2 failure criteria, respectively. ASTRO-defined bDFS rates were 96.0%, 87.0%, and 72.5% for low, intermediate, and high RG's. CONCLUSION: The data presented here demonstrate the feasibility of performing SPECT/CT BTV dose escalation in a mature series. (c) 2007 American Brachytherapy Society. All rights reserved.