Size matters: a comparison of T1 and T2 peripheral non-small-cell lung cancers treated with stereotactic body radiation therapy (SBRT).
OBJECTIVE
The purpose of this study was to compare the outcomes and local control rates of patients with peripheral T1 and T2 non-small-cell lung cancer treated with stereotactic body radiation therapy.


METHODS
The records of 40 consecutive patients treated with 3- or 5-fraction lung stereotactic body radiation therapy for peripheral, clinical stage I non-small-cell lung cancer were reviewed. Stereotactic body radiation therapy was delivered at a median dose of 60 Gy. Doses to organs at risk were limited based on the Radiation Therapy Oncology Group 0236 treatment protocol. Patients were staged clinically. Median follow was 12.5 months.


RESULTS
Twenty-seven (67%) patients and 13 (33%) patients had T1 and T2 tumors, respectively. Thirty-seven (94%) patients were medically inoperable. Nine (23%) patients had chest wall pain after stereotactic body radiation therapy. Symptomatic pneumonitis developed in 4 (10%) patients. Increasing tumor size correlated with worse local control and overall survival. The median recurrence-free survival for T1 and T2 tumors was 30.6 months (95% confidence interval [CI], 26.9-34.2) and 20.5 months (95% CI, 14.3-26.5), respectively (P = .038). Local control at 2 years was 90% and 70% in T1 and T2 tumors, respectively (P = .03). The median survival for T1 and T2 tumors was 20 months (95% CI, 20.1-31.6) and 16.7 months (95% CI, 10.8-21.2), respectively (P = .073).


CONCLUSIONS
Stereotactic body radiation therapy for T2 non-small-cell lung cancer has a higher local recurrence rate and trended toward a worse survival than did T1 lesions. Tumor size is an important predictor of response to stereotactic body radiation therapy and should be considered in treatment planning.
Dunlap
Neal E
NE
Department of Radiation Oncology, University of Virginia, Charlottesville, VA 22908, USA.
Larner
James M
JM
Read
Paul W
PW
Kozower
Benjamin D
BD
Lau
Christine L
CL
Sheng
Ke
K
Jones
David R
DR
D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D016634:Radiosurgery / Q000009:adverse effects; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014768:Virginia