67Ga scintigraphy for the evaluation of recurrences and residual masses in patients with lymphoma.

67Ga scintigraphy has proven to be of value in the evaluation of patients with lymphoma, especially in their management after treatment. In this study, computed tomography (CT) and 67Ga scans were compared in 53 patients with lymphoma who had previously been treated. Twenty-eight were patients in continuous clinical remission in whom recurrence was suspected. The remaining 25 patients were studied between 1 and 3 months post-treatment to assess a residual mass. The sensitivity for the detection of lymphoma recurrence was 88% for 67Ga, with two false-negative results, and 59% for CT, with seven false-negative results. In the diagnosis of recurrence, the specificity of 67Ga was 100% and that of CT 72%, with three false-positive results. Therapeutic response was assessed in 25 patients and the ability to predict response to treatment resulted in a specificity of 86% for 67Ga and 81% for CT. Treatment failed in four patients, as detected by 67Ga scan, whereas CT did not detect any of these. In the remaining 21 patients who showed good response to treatment, there were three false-positive results for 67Ga and four for CT. 67Ga scintigraphy can detect relapse more accurately and much earlier than CT, as well as diagnose complete remission after treatment. Therefore, 67Ga scintigraphy should be used routinely in monitoring response to treatment in lymphoma.