Early detection of lymphoma recurrence with gallium-67 scintigraphy

Early detection of tumor relapse in lymphoma patients is often a difficult diagnostic problem. CT, which detects a mass, often cannot differentiate between fibrosis or relapsed tumor. For this reason, we have studied the value of 67Ga scintigraphy in the diagnosis of tumor recurrence. The sensitivity of 67Ga scintigraphy in the detection of lymphoma recurrence was studied at an average interval of 8.7 mo following treatment in 32 patients who developed recurrent lymphoma. Its specificity was studied in 36 patients with no recurrence who were in continuous clinical remission. At the time of appearance of relapse, the sensitivity of whole-body 67Ga imaging was 95% and the specificity 89%. In 12 events of recurrence in 10 patients, 67Ga scintigraphy was abnormal at sites that later proved to be regions of relapse. In these patients, scintigraphy demonstrated recurrence an average of 6.8 mo before the appearance of clinical symptoms, findings on clinical examination or abnormality on CT or chest x-rays. Gallium-67 scintigraphy, which permits screening of the whole body for recurrence in a single study, was of particular value in evaluating lymphoma recurrence, since 27% of the recurrences were located exclusively in sites different from the original sites of disease. Gallium-67 scintigraphy appears to be a sensitive and specific test for restaging patients with lymphoma recurrence.