PURPOSE: We compared outcomes in intermediate-risk prostate cancer patients treated with dose-escalated adaptive image-guided radiation therapy (IGRT) or dose-escalated high-dose-rate brachytherapy boost (HDR-B).
METHODS AND MATERIALS: Patients with intermediate-risk prostate cancer by National Comprehensive Cancer Network criteria were treated with either CT-based off-line adaptive IGRT (n = 734) or HDR-B (n = 282). IGRT was delivered with 3D-conformal or intensity-modulated radiation therapy with a median dose of 77.4 Gy. For HDR-B, the whole pelvis received a median 46 Gy, and the prostate 2 implants of 9.5 Gy (n = 71), 10.5 Gy (n = 155), or 11.5 Gy (n = 56).
RESULTS: Median followup was 3.7 years for IGRT and 8.0 years for HDR-B (p < 0.001). Eight-year biochemical control was 86% for IGRT and 91% for HDR-B (p = 0.22), disease-free survival 67% for IGRT and 79% for HDR-B (p = 0.006), and overall survival 75% for IGRT and 86% for HDR-B (p = 0.009). Cause-specific survival (8-year, 100% vs. 99%), freedom from distant metastases (98% vs. 97%), and freedom from local recurrence (98% vs. 98%) did not differ (p > 0.50 each). A worse prognosis group was defined by percent positive prostate biopsy cores >50%, perineural invasion, or stage T2b-c, encompassing 260 (35%) IGRT and 171 (61%) HDR-B patients. These patients evidenced a 5-year biochemical control of 96% for HDR-B and 87% for IGRT (p = 0.002).
CONCLUSIONS: Dose-escalated IGRT and HDR-B both yield excellent clinical outcomes for patients with intermediate-risk prostate cancer. Improved biochemical control with HDR-B for patients with worse pretreatment characteristics suggests that a subgroup of intermediate-risk prostate cancer patients may benefit from dual-modality treatment.
Written by:
Marina O, Gustafson GS, Kestin LL, Brabbins DS, Chen PY, Ye H, Martinez AA, Ghilezan MI, Wallace M, Krauss DJ. Are you the author?
Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
Reference: Brachytherapy. 2013 Jul 18. pii: S1538-4721(13)00280-8.
doi: 10.1016/j.brachy.2013.05.004
PubMed Abstract
PMID: 23871661
UroToday.com Prostate Cancer Section
