Definitive radiation therapy for medically inoperable patients with stage I and II non-small cell lung cancer

The treatment results of 84 patients with clinical stage I and II non-small cell lung cancer (NSCLC) treated with definitive radiation therapy (RT) alone at Gunma University Hospital from 1976 through 1989 were retrospectively analyzed. All patients were treated with 10 MV X-rays using anteroposterior parallel opposed fields. The total dose ranged from 60 to 80 Gy, except for one patient given 90 Gy with once-daily standard fractionation. The 2-and 5-year survival rates were 74% and 31% for 28 patients with stage I disease, compared with 40% and 19% for 56 patients with stage II, respectively (P < 0.05). Fifty-three patients with tumors less than 5 cm in diameter had an in-field progression rate of 14% at 2 years, in comparison with 38% of 31 patients with tumors greater than 5 cm (P < 0.05). The difference of survival rates for these two groups was statistically significant (P < 0.005). Ten patients given a total dose of 80 Gy or over had only 17% local progression at the time of last follow-up, however, they had not been alive beyond 3 years because they developed pulmonary insufficiency due to severe stenosis of the proximal bronchus. A multivariate analysis indicated primary tumor size as the only significant prognostic factor for survival. In conclusion, the tumor size was the most important factor not only for local control but also for distant failure. It was also suggested that the optimal radiation dose for medically inoperable stage I-II NSCLC ranged from 60 to 70 Gy with once-daily standard fractionation. Radiat Oncol Invest 1996;4:165–170.