title: Stereotactic body radiation therapy for the treatment of early-stage minimally invasive adenocarcinoma or adenocarcnioma in situ (formerly bronchioloalveolar carcinoma): a patterns of failure analysis.
abstract: BACKGROUND
  Ongoing prospective trials exploring stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) often exclude minimally invasive adenocarcinoma or adenocarcnioma in situ, formerly bronchioloalveolar carcinoma (BAC), due to concerns for accurate target delineation on CT. We performed a patterns of failure analysis to compare outcomes between BAC and other NSCLC subtypes.
  
  
  METHODS
  One hundred twenty patients with early stage NSCLC were treated with SBRT from 2004-2009. Pathologic confirmation of NSCLC was obtained in 97 patients. Radiotherapy was delivered according to RTOG guidelines. The log-rank test was used to compare outcomes between BAC and other NSCLC.
  
  
  RESULTS
  Median follow-up was 29 months. The median SBRT dose was 5400 cGy. Thirteen patients had radiographically diagnosed BAC and five patients had biopsy confirmed BAC, of which two had both. The three-year local control was 100% for biopsy-proven or radiographically diagnosed BAC (n = 18) and 86% for all other NSCLC subtypes (n = 102) (p = 0.13). Likewise, no significant difference was detected between BAC and other NSCLC for 3-year regional failure (12% vs. 20%, p = 0.45), progression-free survival (57.6% vs. 53.5%, p = 0.84) or overall survival (35% vs. 47%, p = 0.66). There was a trend towards lower three-year rates of freedom from distant failure in patients with any diagnosis of BAC compared to those without (26% vs. 38%, p = 0.053).
  
  
  CONCLUSIONS
  Compared to other NSCLC subtypes, BAC appears to have similar patterns of failure and survival after treatment with SBRT, however there may be an increased risk of distant metastases with BAC. RTOG guideline-based target delineation provides encouraging local control rates for patients with BAC.
authors.affiliation: Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University in St, Louis, 4921 Parkview Place, Campus Box 8224, St, Louis, MO 63110, USA. crobinson@radonc.wustl.edu
authors.forename: Shahed N
authors.initials: SN
authors.lastname: Badiyan
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bierhals
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Olsen
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Creach
authors.forename: Adam A
authors.initials: AA
authors.lastname: Garsa
authors.forename: Todd
authors.initials: T
authors.lastname: Dewees
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Bradley
authors.forename: Clifford G
authors.initials: CG
authors.lastname: Robinson
mesh_terms: D000230:Adenocarcinoma / Q000532:radiotherapy*; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D003198:Computer Simulation; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016634:Radiosurgery / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome