Place de la radiothérapie dans la prise en charge des carcinomes bronchiques à petites cellules localisés

Small cell lung carcinomas are aggressive on account of their high and early risk of dissemination. They represent less than 20% of all lung cancers and only a third of these present with limited stage disease at diagnosis. Currently, treatment is based on synchronous thoracic irradiation and chemotherapy combining platinum salts and etoposide with or without other drugs. Because of the high risk of brain metastases, prophylactic cranial irradiation (PCI) is indicated in patients with a complete response and should be part of the standard management of these patients on the basis of a meta-analysis showing a 5% increase in survival at three years. In limited stage disease 5 year survival rates can reach 25% but the majority of patients will relapse. This progress is the consequence of a better combination of thoracic and cerebral irradiation and polychemotherapy. Even in extensive disease PCI reduces the risk of brain metastases and significantly improves overall survival. Many issues are subject to further clinical research concerning modalities of combination radio-chemotherapy, radiotherapy target volumes, optimum dosage, and the use of drugs in association with irradiation.