Guidelines for Complications of Cancer Treatment Vol VIII Part B

PneumonitisThe clinical syndrome of pneumonitis usually occurs l-3months after completion of radiation or drug therapy.Symptomatic pneumonitis occurs in approximately 5- 15% ofpatients irradiated for mediastinal lymphoma, lung, or breastcancer.Clinical features: Clinical features depend on the degree ofpulmonary involvement. There may be lowgrade fever,nonspecific respiratory symptoms such as congestion, cough,and fullness in the chest. Severe cases could manifest withdyspnea, pleuritic chest pain, cough or blood stained sputum.Generally after the transient acute phase, there is theintermediate phase which can progress to the eventual fibroticphase.Diagnostic modalities: The chest x-ray (CXR) may reveal adiffuse infiltrate corresponding to the radiation field. Thisappears as a result of an acute exudative edema that is initiallyfaint and may become prominent later. Computed tomographyscans are more sensitive and detect abnormalities in > 50% ofpatients. Ventilation/perfusion scans are very frequentlyabnormal following thoracic irradiation. Perfusion defects areseen more commonly than ventilation defects andapproximately correspond to the irradiated volume. Usingplanar images, perfusion and ventilation abnormalities are seenin 53-95% and 35-45% of irradiated patients, respectively.Pulmonary FibrosisIn contrast to the acute reaction, chronic effects of cytotoxictherapy are observed from months to years following treatment.Pulmonary fibrosis develops insidiously in the previouslyirradiated field, and stabilizes after 1 or 2 years.316