title: Image-guided stereotactic body radiation therapy for localized prostate cancer.
abstract: OBJECTIVE
  We report the results of a retrospective study of stereotactic body radiation therapy (SBRT) using CyberKnife for localized prostate cancer. The study focused on the safety and feasibility of this treatment modality.
  
  
  METHODS
  Between October 2002 and December 2007, 44 patients suffering from localized adenocarcinoma of the prostate were treated with SBRT using CyberKnife at the Korea Cancer Center Hospital. The patients were divided into 3 groups: a low-risk group (5 patients), an intermediate-risk group (10 patients), and a high-risk group (29 patients). Five patients received 32 Gy in 4 fractions, 28 patients received 34 Gy in 4 fractions, and 11 patients received 36 Gy in 4 fractions.
  
  
  RESULTS
  The median age of the patients was 69 years (range, 53-79 years) and the median duration of follow-up 40 months (range, 12-78 months). There were 6 acute and 3 late grade 2 urinary toxicities, and 4 acute and 5 late grade 2 rectal toxicities, but there were no grade 3 or higher treatment-related toxicities. The 5-year cause-specific survival rate and progression-free survival rate were both 100%. At last follow-up, the biochemical failure-free rate of the low-risk, intermediate-risk and high-risk patients was 100%, 100% and 90.8%, respectively.
  
  
  CONCLUSIONS
  SBRT using CyberKnife for localized prostate cancer is safe and well tolerated. We obtained promising results with 34 Gy in a 4-fraction regimen especially for the high-risk patients.
authors.affiliation: Department of Radiation Oncology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
authors.forename: Jin-Kyu
authors.initials: JK
authors.lastname: Kang
authors.forename: Chul Koo
authors.initials: CK
authors.lastname: Cho
authors.forename: Chul Won
authors.initials: CW
authors.lastname: Choi
authors.forename: Seongyul
authors.initials: S
authors.lastname: Yoo
authors.forename: Mi-Sook
authors.initials: MS
authors.lastname: Kim
authors.forename: Kwangmo
authors.initials: K
authors.lastname: Yang
authors.forename: Hyungjun
authors.initials: H
authors.lastname: Yoo
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Seo
authors.forename: Dong Han
authors.initials: DH
authors.lastname: Lee
authors.forename: Moonki
authors.initials: M
authors.lastname: Jo
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000276:immunology / Q000473:pathology / Q000532:radiotherapy*; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen