Clinical study of stereotactic gamma-ray body radiation therapy for patients with stage I/II nonsmall cell lung cancer

Objective: To further evaluate the value of the stereotactic gamma-ray body radiation therapy (γ-SBRT) for patients with stage I/II non-small cell lung cancer (NSCLC) basing on the preliminary studies. Methods: Twenty-nine eligible patients with stage I/II NSCLC who is unable or unwilling to receive surgery underwent treatment prospectively with γ-SBRT (OUR-QGD). Patients were fixed by vacuum bag. Each patient underwent slow CT simulation at 5 s/slide with thickness of 5 mm and interval of 5 mm to take into consideration tumor motion. A total dose of 50 Gy was delivered at 5 Gy/fraction to 50% isodose line covering 100% of the PTV, with 60 Gy at 6 Gy/fraction to 60% isodose line covering 90% of the CTV, 70 Gy at 7 Gy/fraction to 70% isodose line covering 80% of the GTV, and 10 times finished in 2 weeks, 5 fractions per week. Results: The follow-up rate was 97%. The 6 month local tumor response rate was 93%, with CR 86%, and PR 7%. The 1-, 2-year local control rates were both 93%. The 1-, 2-year overall survival rates for the whole group, stage I and stage II were 97% and 89%, 100% and 92%, 67% and 67%, respectively. The 1-, 2-year progression-free survival were 90% and 86%, respectively. 34% of the patients had acute radiation toxicities (grade 1, 2 and 3 in 6, 2 and 2 patients, respectively), and 38% late radiation toxicities (grade 1 and 2 in 10 and 1, patients). Conclusions: γ-SBRT is a safe and effective treatment regimen, resulted in promising local control and survival with minor toxicity. (authors)