Role of 18F-FDG PET-CT in Monitoring the Cyclophosphamide Induced Pulmonary Toxicity in Patients with Breast Cancer — 2 Case Reports

Drug induced pulmonary toxicity is not uncommon with the use of various chemotherapeutic agents. Cyclophosphamide is a widely used chemotherapeutic drug in the treatment of breast cancer. Although rare, lung toxicity has been reported with cyclophosphamide use. Detection of bleomycin induced pulmonary toxicity and pattern of 18F-fluorodeoxyglucose (18F-FDG) uptake in lungs on fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) has been elicited in literature in relation to lymphoma. However, limited data is available regarding the role of 18F-FDG PET-CT in monitoring drug induced pulmonary toxicity in breast cancer. We here present two cases of cyclophosphamide induced drug toxicity. Interim 18F-FDG PET-CT demonstrated diffusely increased tracer uptake in bilateral lung fields in both these patients. Subsequently there was resolution of lung uptake on 18F-FDG PET-CT scan post completion of chemotherapy. These patients did not develop significant respiratory symptoms during chemotherapy treatment and in follow up