[Importance of timing for radiation therapy in limited-stage small cell lung cancer]

We defined one group of patients who underwent radiotherapy within 75 days from the beginning of treatment as the early RT group, whereas another group of patients who underwent radiotherapy at least 75 days after the beginning of treatment was defined as the late RT group. The response rate (CR + PR) of the early RT group was 92.1% while that of the late RT group was 72.3%. The response rate for radiation therapy thus was significantly better in the early RT group. The 2 and 5-year actuarial survival rates of the early RT group were 22.1% and 9.2%, while those of the late RT group were 19.1% and 8.5%. Then respective median survival times (MST) were 14 months and 13 months. There was no significant difference in survival rates between the two groups. As much as the quality of life is concerned, early RT group would show here better results.