Response to thoracic radiotherapy in patients with small cell carcinoma of the lung after failure of combination chemotherapy.

Chest radiotherapy was given to 23 patients with small cell carcinoma of the lung after development of progressive intrathoracic tumor on chemotherapeutic regimens. Treatment schedules were variable, with a median dose of 3,200 rad (32 Gy) in 10 fractions. Objective tumor regression within the radiation portal was observed in 12 patients (52%). Only 3/12 responders did not develop clinically detectable local tumor recurrence before death. Actuarial median time to local tumor progression was 2.5 months in responding and 3.5 months in nonresponding patients. Relapse of intrathoracic small cell carcinoma despite combination chemotherapy was not effectively treated by chest irradiation in the doses utilized. If sustained local palliation is required in this population, higher doses of radiation should be considered.