Background: The incidence of malignant melanoma is rising; it now has an incidence of ten per 100 000 per annum in the UK. The development of metastases is unpredictable, but prognosis is linked directly to the initial stage at diagnosis. Positron emission tomography (PET) can allow the detection of malignant cells at a relatively early stage.
Methods: A review of the literature was undertaken by searching the Medline database for the period 1980-2000 without any language restrictions.
Results: The overall sensitivity and specificity of PET are 74-100 and 67-100 per cent respectively. PET has a reduced sensitivity and specificity for thinner lesions (less than 1 x 5 mm). Comparison with computed tomography and magnetic resonance imaging has shown a higher sensitivity and specificity for PET in all regions of the body except the thorax.
Conclusion: Currently the accepted indication for PET is recurrent melanoma when surgical intervention is being considered. However, other potential indications include the detection of occult or distant metastasis at initial presentation and the clarification of abnormal radiological findings at follow-up. The routine use of PET for American Joint Commission on Cancer stage I or II disease is of uncertain benefit and is not indicated at present.