title: Stereotactic ablative radiation therapy for centrally located early stage or isolated parenchymal recurrences of non-small cell lung cancer: how to fly in a "no fly zone".
abstract: OBJECTIVE
  We extended our previous experience with stereotactic ablative radiation therapy (SABR; 50 Gy in 4 fractions) for centrally located non-small cell lung cancer (NSCLC); explored the use of 70 Gy in 10 fractions for cases in which dose-volume constraints could not be met with the previous regimen; and suggested modified dose-volume constraints.
  
  
  METHODS
  Four-dimensional computed tomography (4DCT)-based volumetric image-guided SABR was used for 100 patients with biopsy-proven, central T1-T2N0M0 (n=81) or isolated parenchymal recurrence of NSCLC (n=19). All disease was staged with positron emission tomography/CT; all tumors were within 2 cm of the bronchial tree, trachea, major vessels, esophagus, heart, pericardium, brachial plexus, or vertebral body. Endpoints were toxicity, overall survival (OS), local and regional control, and distant metastasis.
  
  
  RESULTS
  At a median follow-up time of 30.6 months, median OS time was 55.6 months, and the 3-year OS rate was 70.5%. Three-year cumulative actuarial local, regional, and distant control rates were 96.5%, 87.9%, and 77.2%, respectively. The most common toxicities were chest-wall pain (18% grade 1, 13% grade 2) and radiation pneumonitis (11% grade 2 and 1% grade 3). No patient experienced grade 4 or 5 toxicity. Among the 82 patients receiving 50 Gy in 4 fractions, multivariate analyses showed mean total lung dose >6 Gy, V20 >12%, or ipsilateral lung V30 >15% to independently predict radiation pneumonitis; and 3 of 9 patients with brachial plexus Dmax >35 Gy experienced brachial neuropathy versus none of 73 patients with brachial Dmax <35 Gy (P=.001). Other toxicities were analyzed and new dose-volume constraints are proposed.
  
  
  CONCLUSIONS
  SABR for centrally located lesions produces clinical outcomes similar to those for peripheral lesions when normal tissue constraints are respected.
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Electronic address: jychang@mdanderson.org.
authors.forename: Joe Y
authors.initials: JY
authors.lastname: Chang
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Qiao-Qiao
authors.initials: QQ
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Qing-Yong
authors.initials: QY
authors.lastname: Xu
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Allen
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Neal
authors.initials: N
authors.lastname: Rebueno
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gomez
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Peter
authors.initials: P
authors.lastname: Balter
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Komaki
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Reza
authors.initials: R
authors.lastname: Mehran
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Swisher
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Jack A
authors.initials: JA
authors.lastname: Roth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D056973:Four-Dimensional Computed Tomography; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000601:surgery; D011446:Prospective Studies; D017564:Radiation Pneumonitis / Q000209:etiology; D016634:Radiosurgery / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012042:Registries; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome