Malignant metastasis to the lung is common. It may present as a solitary enlarging nodule, as multiple nodules ranging enormously in size and number, and/or with diffuse lymphatic involvement. Diagnosis can usually be secured by percutaneous CT-guided biopsy and most suspicious lesions will be PET positive. Resection remains the treatment of choice, and good prognostic factors include the time from treatment of the primary tumour to the development of lung metastases, the fewer the number, the absence of extrapulmonary metastases, and the longer the tumour doubling time. The most favourable group are younger patients with a good performance status, with sarcomas who present with lesions a year or more after successful treatment of the primary disease. Factors including older age, male sex, and more lung metastases predict poorer survival after resection of any initial pulmonary metastases.
201T1 to 67Ga uptake ratio as an indicator for predicting tumour doubling time in human pulmonary neoplasms