A comparison of high-dose continuous and split-course irradiation in non-oat-cell carcinoma of the lung

From 1969 through 1979, 171 patients with localized but inoperable or unresectable non-oat-cell carcinoma (NOCC) of the lung completed high-dose definitive irradiation. One hundred fifteen received continuous course irradiation to 6000-6500 rad at 180-200 rad/day. Fifty-six received split-course irradiation to 5500 rad at 250-300 rad/day, which included a 2-week break. The two groups were similar with respect to all measured variables. There were no differences in the response rates, failure patterns, survival, or complication rates between the two regimens. The 5-year survival was 6%, with 25.8% dying with infield failure alone and 54.7% with metastases. The incidence of complications was 8.2%, predominantly acute radiation pneumonitis. A review of the most comparable literature reveals no significant improvement in the cure rate of definitively irradiated NOCC with increasing tumor dose, split-course irradiation, or other modifications of radiotherapeutic technique over the past 25 years. The problems of frequent local recurrences and distant metastases, and the poor response of NOCC to presently available systemic therapy, requires that more effective and broadly applicable local and systemic therapies be developed before substantial improvements in the cure rate of NOCC can be expected.