[Predictive factors for acute radiation pneumonitis]

Thoracic irradiation is a major weapon in the treatment of nonmetastatic primary lung cancer, in particular in patients presenting a locally advanced disease of the mediastinium. Acute radiation pneumonitis (ARP) is one of the main limiting toxicities. The purpose of this work is to sum up the current state of knowledge of the factors of risk of developing ARP. The incidence after conventional irradiation, in patients with non small cell lung cancer (NSCLC) is about 7 to 10% in the moderate although symptomatic forms of ARP and about 1 to 3% in the severe forms. The factors related to the patient, the tumour or treatments prior to the irradiation do not determine any specific risk of ARP besides an age of over 65 years that remains debatable. The validated predictive factors of ARP are mainly related to the irradiation factors (healthy lung volumes irradiated, average dose of irradiation, etc.). Nevertheless, in spite of the adjustment of these parameters, the individual susceptibility to the toxicity of thoracic radiotherapy remains significant, directing current research to the biological markers intrinsic to the patient. In particular, the involvement of early variations of certain cytokines (IL-6, IL-10, TGF-ss) in the occurrence of ARP during irradiation has been suggested and studies are under way to confirm their involvement and determine their role.