[Nuclear medicine procedures in lung cancer imaging]

Lung cancer is nowadays one of the most common malignancies and the leading cause of cancer mortality worldwide. Its early diagnosis and treatment is therefore the target of extensive research. Although radiologic imaging methods, especially CT, are the most widely used, they have well known constraints, including solitary pulmonary nodule characterisation, mediastinal lymph node staging, characterisation of the remaining tissue after chemo- or radiotherapy and early diagnosis of relapse. The main reason for these drawbacks is that radiologic methods primarily rely upon morphologic and anatomic criteria, which usually have little relevance to the biological status of a pulmonary lesion. The radiopharmaceuticals used in nuclear medicine, exploit special pathophysiologic localization mechanisms and provide unique functional information for their target tissues. Thus, many of the above mentioned problems can be elucidated. This is obvious in the published figures of sensitivity and specificity of the radionuclidic methods, which are often superior to those of CT [Table 1: see text]. In this article the main nuclear medicine procedures in the field of lung cancer imaging are reviewed. Emphasis is given in newer developments such as (99m)Tc-sestamibi, labeled somatostatin analogues and positron emission tomography with (18)F-FDG. We especially describe the "weaknesses" of the anatomic-radiologic imaging modalities and how the attending physicians, i.e. the pneumonologists, oncologists and thoracic surgeons can overcome them, by using the functional imaging methods of nuclear medicine.