Positron emission tomography and gallium metabolic imaging in lymphoma.

Metabolic imaging allows the recognition of active tumor mass because of its fixed tracer. For patients with Hodgkin's disease and non-Hodgkin lymphoma, (67)gallium and (18)fluorodeoxyglucose (FDG) have been employed. This review describes the role of (67)gallium scintigraphy (Ga-scan) and positron emission tomography (PET) in the staging and follow-up of patients with lymphoma. These tools do not appear to be more powerful than conventional imaging for initial staging and treatment choice. Ga-scan is only valid for thoracic examination. PET imaging following treatment resolves the problem of persisting images on CT scan; nearly all patients with FDG uptake have an early relapse. Whether this examination will allow for intensified treatment and possible cure of more patients is yet to be demonstrated.