Context
Patients with early stage but medically inoperable lung cancer patients have a poor rate of primary tumor control (30-40%) and a high rate of mortality (3-year survival 20-35%) with current management.
Objective
To evaluate the toxicity and efficacy of stereotactic body radiation therapy in a high risk population of patients with early stage but medically inoperable lung cancer.
Design, Setting, and Patients
Phase 2 North American multicenter study of patients with biopsy-proven peripheral T1-T2, N0, M0 non-small cell tumors less than 5 cm in diameter and medical conditions precluding surgical treatment. The prescription dose was 18 Gy per fraction times 3 fractions (54 Gy total) delivered in 1½-2 weeks. The study opened May 26, 2004, and closed October 13, 2006; data were analyzed through August 31, 2009.
Main Outcome Measures
The primary endpoint was primary tumor control with overall survival, disease free survival, adverse events, involved lobe, regional, and disseminated recurrence as secondary endpoints.
Results
A total of 59 patients accrued, of which 55 were evaluable (44 T1 and 11 T2 tumors) with a median follow-up of 34.4 months (range, 4.8 to 49.9 months). Only 1 patient had a primary tumor failure; the estimated 3-year primary tumor control rate was 97.6% (95% confidence interval [CI], 84.3%, 99.7%). Three patients had recurrence within the involved lobe; the 3-year primary tumor and involved lobe (local) control rate was 90.6% (95% CI, 76.0%, 96.5%). Two patients experienced regional failure; the local-regional control rate was 87.2% (95%CI, 71.0%, 94.7%). Eleven patients experienced disseminated recurrence; the 3-year rate of disseminated failure was 22.1% (95% CI, 12.3%, 37.8%). The rates of disease-free and overall survival at 3 years were 48.3% (95% CI, 34.4%, 60.8%) and 55.8% (95% CI, 41.6%, 67.9%), respectively. The median overall survival was 48.1 months (95% CI, 29.6% to not reached). Protocol specified treatment-related grade 3 adverse events were reported in 7 patients (12.7%; 95% CI, 9.6%, 15.8%); grade 4 events were reported in 2 patients (3.6%; 95%CI, 2.7%, 4.5%). No grade 5 adverse events were reported.
Conclusion
Patients with inoperable non-small cell lung cancer who received stereotactic body radiation therapy had a survival rate of 55.8% at 3 years, high rates of local tumor control, and moderate treatment-related morbidity.