title: Comparison of dose-escalated, image-guided radiotherapy vs. dose-escalated, high-dose-rate brachytherapy boost in a modern cohort of intermediate-risk prostate cancer patients.
abstract: OBJECTIVE
  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
  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.
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Marina
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Gustafson
authors.affiliation: Michigan HealthCare Professionals/21st Century Oncology, Farmington Hills, MI.
authors.forename: Larry L
authors.initials: LL
authors.lastname: Kestin
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
authors.forename: Donald S
authors.initials: DS
authors.lastname: Brabbins
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
authors.forename: Peter Y
authors.initials: PY
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
authors.forename: Hong
authors.initials: H
authors.lastname: Ye
authors.affiliation: Michigan HealthCare Professionals/21st Century Oncology, Farmington Hills, MI.
authors.forename: Alvaro A
authors.initials: AA
authors.lastname: Martinez
authors.affiliation: Michigan HealthCare Professionals/21st Century Oncology, Farmington Hills, MI.
authors.forename: Michel I
authors.initials: MI
authors.lastname: Ghilezan
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI.
authors.forename: Michelle
authors.initials: M
authors.lastname: Wallace
authors.affiliation: Department of Radiation Oncology, Beaumont Health System, Royal Oak, MI. Electronic address: dkrauss@beaumont.edu.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Krauss
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D061089:Radiotherapy, Image-Guided / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods
keywords: Comparative outcomes; High-dose-rate brachytherapy; IMRT; Image-guided radiation therapy; Prostate cancer