Imaging in lung cancer: recent advances in PET-CT and screening
- Correspondence to David R Baldwin, Consultant Respiratory Physician, Department of Respiratory Medicine, David Evans Research Centre, City Hospital Campus, Nottingham University Hospitals, Nottingham NG5 1PB, UK;
Lung cancer is probably the most intensely imaging dependent sub-specialty within respiratory medicine. Historically chest physicians have had close involvement with imaging. The development of mass miniature chest radiographs is attributed to Manuel Dias de Abreu, a Brazillian pulmonologist1 and in conjunction with providing a tuberculosis service, chest physicians have reported mass miniature chest radiographs, independent of radiologists. Although the latter is now neither appropriate or indeed the case, in lung cancer, chest physicians along with other clinicians within the cancer multidisciplinary team (MDT) rely heavily on imaging and, aided by the accessibility of images afforded by the Picture Archiving and Communication System (PACS) are becoming increasingly expert. Furthermore, chest physicians are using imaging more for their own diagnostic and therapeutic procedures; in particular transthoracic and endobronchial ultrasound. It is axiomatic therefore that a radiologist who is firmly committed to the cancer MDT makes an enormous contribution to an effective care pathway. Thus any new development in imaging will have a considerable impact on lung cancer clinicians' clinical practice whether they deal principally with diagnosis and staging (chest physicians and radiologists) or treatment (oncologists and thoracic surgeons).
Over the last 10 years there have been important developments in the lung cancer care pathway from early diagnosis through diagnosis and staging and to treatment, many of these driven by improved imaging. It is necessary to have a clear idea about the performance of an imaging test (or any test) to understand how a result should influence management. A self-evident point about imaging tests is that because they do not sample tissue, they tend to yield a greater number of false positive and false negative results and therefore have a lower specificity and negative predictive value compared with minimally invasive tests. Indeed, as imaging tests improve their sensitivity the place of tests …