Systemic review of the patterns of failure following stereotactic body radiation therapy in early-stage non-small-cell lung cancer: clinical implications.
OBJECTIVE
To analyze the patterns of failure, the toxicity profile, and the factors influencing efficacy of stereotactic body radiation (SBRT) for early-stage non-small-cell lung cancer (NSCLC).


METHODS
A search was based on PubMed electronic databases. All searches were conducted in May, 2009.


RESULTS
The local control ranged from 80% to 100% in most studies with adequate isocentric or peripheral biologically effective dose (BED). Recurrences were associated with increased tumor size. The main pattern of failure after SBRT was distant metastasis. Grades 3-5 toxicity occurred mostly in centrally located tumors, and adjuvant chemotherapy may further decrease all recurrences; possibly translating to a survival benefit in large or centrally located tumors where high BED cannot be safely reached.


CONCLUSIONS
SBRT is an excellent treatment option for early-stage, and mostly medically inoperable, NSCLC. BED at both the isocenter and the tumor periphery is very important for optimal tumor control; higher doses are required for large (T2) lesions; SBRT for centrally located tumors can be feasible with a much less aggressive dose regimen than 60-66Gy/3 fractions and adjacent critical structures excluded from the target volume; chemotherapy may optimize the clinical outcome in large or centrally located lesions.
Chi
Alexander
A
Department of Radiation Oncology, University of Arizona, 1501 N Campbell Ave., Tucson, AZ 85724, USA. achiaz2010@gmail.com
Liao
Zhongxing
Z
Nguyen
Nam P
NP
Xu
Jiahong
J
Stea
Baldassarre
B
Komaki
Ritsuko
R
D006801:Humans; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000601:surgery; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016634:Radiosurgery; D017211:Treatment Failure