When is PET not useful in the assessment of lymphoma?

Excerpt

Cure rates of greater than 80% are achieved overall in patients with Hodgkin's disease, with greater than 90% cure in favourable disease and 65% cure in less favourable disease. Therapy is tailored according to the category, with more favourable categories having shorter course chemotherapy with local radiotherapy [1]. The challenges are to improve the prognosis of the less favourable disease and at the same time to minimise the long-term side-effects of treatment in all groups. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) may assist in meeting these challenges by improving staging of disease, differentiating the 'scars' of treatment from active tumour and providing an early indication of treatment response or failure. In particular, PET could be used to plan the extent of radiotherapy necessary and might help to rationalise treatment in the less favourable groups by diverting to transplant early those patients who are chemo-resistant. The body of evidence that PET is of value in many circumstances in lymphoma management is increasing. Are there occasions, however, when PET is not likely to be of use? …