Gallium-67 citrate imaging in lymphoma

Gallium imaging in lymphoma fulfils an important clinical role. The determination of the nature of a residual mass post therapy has prognostic implications for the patient and often changes treatment plans. It has been estimated that approximately 68 per cent of lymphoma patients have a residual mass after treatment but of those only 18 per cent relapse. Morphological imaging techniques such as Xray computed tomography (CT) is unable to determine whether a residual mass after treatment represents tumour or fibrotic and necrotic tissue. Gallium, being a viability agent, is able to accurately identify the amount of viable tumour cells in a mass after treatment allowing assessment of residual masses with increased confidence. This case study presents a 61 year-old lady with a history of high-grade non Hodgkin's lymphoma originating in the thyroid. Gallium imaging was undertaken immediately post surgery, three months after initial therapy and again after a resurgence in symptoms. On all three occasions the Gallium scan showed more extensive disease than that identified on CT. The most recent Gallium scan incorporated CT co registration allowing a concomitant interpretation of anatomy and physiology to be undertaken. In this patient Gallium imaging accurately differentiated active disease from post therapy changes effecting a change in disease status allowing appropriate therapy to be undertaken. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc