title: Stereotactic body radiation therapy versus intensity-modulated radiation therapy for prostate cancer: comparison of toxicity.
abstract: OBJECTIVE
  Stereotactic body radiation therapy (SBRT) is a technically demanding prostate cancer treatment that may be less expensive than intensity-modulated radiation therapy (IMRT). Because SBRT may deliver a greater biologic dose of radiation than IMRT, toxicity could be increased. Studies comparing treatment cost to the Medicare program and toxicity are needed.
  
  
  METHODS
  We performed a retrospective study by using a national sample of Medicare beneficiaries age ≥ 66 years who received SBRT or IMRT as primary treatment for prostate cancer from 2008 to 2011. Each SBRT patient was matched to two IMRT patients with similar follow-up (6, 12, or 24 months). We calculated the cost of radiation therapy treatment to the Medicare program and toxicity as measured by Medicare claims; we used a random effects model to compare genitourinary (GU), GI, and other toxicity between matched patients.
  
  
  RESULTS
  The study sample consisted of 1,335 SBRT patients matched to 2,670 IMRT patients. The mean treatment cost was $13,645 for SBRT versus $21,023 for IMRT. In the 6 months after treatment initiation, 15.6% of SBRT versus 12.6% of IMRT patients experienced GU toxicity (odds ratio [OR], 1.29; 95% CI, 1.05 to 1.53; P = .009). At 24 months after treatment initiation, 43.9% of SBRT versus 36.3% of IMRT patients had GU toxicity (OR, 1.38; 95% CI, 1.12 to 1.63; P = .001). The increase in GU toxicity was due to claims indicative of urethritis, urinary incontinence, and/or obstruction.
  
  
  CONCLUSIONS
  Although SBRT was associated with lower treatment costs, there appears to be a greater rate of GU toxicity for patients undergoing SBRT compared with IMRT, and prospective correlation with randomized trials is needed.
authors.affiliation: James B. Yu, Laura D. Cramer, Jeph Herrin, Pamela R. Soulos, and Cary P. Gross, Yale School of Medicine; James B. Yu and Cary P. Gross, Yale Cancer Center, New Haven, CT; Jeph Herrin, Health Research and Educational Trust, Chicago, IL; and Arnold L. Potosky, Georgetown University School of Medicine, Washington, DC.
authors.forename: James B
authors.initials: JB
authors.lastname: Yu
authors.forename: Laura D
authors.initials: LD
authors.lastname: Cramer
authors.forename: Jeph
authors.initials: J
authors.lastname: Herrin
authors.forename: Pamela R
authors.initials: PR
authors.lastname: Soulos
authors.forename: Arnold L
authors.initials: AL
authors.lastname: Potosky
authors.forename: Cary P
authors.initials: CP
authors.lastname: Gross
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D006278:Medicare; D011471:Prostatic Neoplasms / Q000191:economics / Q000532:radiotherapy* / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects / Q000191:economics / Q000379:methods; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000191:economics / Q000379:methods; D012189:Retrospective Studies; D014481:United States