1. To be aware of the complications of chemotherapy and radiotherapy on the CNS. 2. To be able to recognise the specific imaging features of these complications. 3. To understand the optimal use of imaging techniques for evaluating these complications. Patients being treated for malignancy are vulnerable to a unique set of complications that are often urgent and are first identified or clarified on radiologic imaging studies. As advances in cancer therapy have resulted in an improved prognosis for the patient, an awareness of the consequences of treatment becomes increasingly important. All cancer treatment modalities are associated with a spectrum of toxic effects that may involve all organ systems. This session will discuss and illustrate the complications of a range of cancer treatments and their effects on the lung, abdomen, pelvis and CNS. The panel will discuss common complications that develop after the completion of cancer treatment and emphasise the importance of radiologists' awareness of these complications. This will permit more effective patient surveillance, which may afford patients the opportunity for earlier intervention and an improved quality of life. In patients undergoing therapy for malignant disease with new pulmonary abnormalities, differentiation between pulmonary manifestations of malignancy, i.e. progressive disease and non-neoplastic changes associated with the therapy may be challenging. The consequences, however, are usually very important as therapy-associated abnormalities may be treated with discontinuation of the therapy whereas progressive malignancy often requires more intense therapy. The knowledge of typical imaging findings of therapy-induced changes as well as strategies to further clarify this dilemma are, therefore, of utmost importance. This presentation will demonstrate the chest radiographic and CT-findings of common therapy-associated pulmonary abnormalities including opportunistic infection with uncommon organisms due to immunosuppression, radiation pneumonitis, pulmonary toxicity due the chemotherapy, graft versus host disease in bone marrow transplant recipients, rejection in pulmonary transplantation and vascular disorders. Learning Objectives: 1. To be familiar with pulmonary complications that may arise in patients being treated for malignancy. 2. To be aware of the possible infectious aetiologies. 3. To learn the appearances of typical and atypical infections, including fungal infection.