Comparison of technetium-99m methoxyisobutylisonitrile and gallium-67 citrate scanning in the assessment of lymphomas

The aim of this study was to compare the value of scintigraphy using technetium-99m methoxy-isobutylisonitrile (MIBI) with that of scintigraphy using gallium-67 citrate in the assessment of Hodgkin's disease and non-Hodgkin's lymphoma and to relate these results with those of CT scan and MRI. Fifty-eight patients were included either for a follow-up examination or for monitoring of their treatment. Twenty-three residual masses were studied. A whole-body scan was performed, followed by single-photon emission computed tomography (SPET) 20 min after injection of 740 MBq of99mTc-MIBI and 72 h after injection of 185 MBq of67Ga citrate. The overall sensitivity of99mTc-MIBI and67Ga citrate was 71% and 68%, respectively, and the overall specificity was 76% and 44%, respectively. For residual masses, the sensitivity was 44% with both tracers and the specificity was 80% with99mTc-MIBI and 53% with67Ga citrate. The positive predictive values were 85% and 68% and the negative predictive values were 59% and 44%, respectively. The signal-to-background ratio was 1.5 for99mTc-MIBI and 2 for67Ga citrate. At present,99mTc-MIBI cannot replace67Ga citrate in the assessment of lymphomas.