Clinical role of Tc-99m-MIBI scintigraphy in non-Hodgkin's lymphoma

This study was designed to investigate the relationship between Tc-99m-hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy and outcome of treatment in patients with non-Hodgkin's lymphoma (NHL). Forty-five patients with NHL were studied with Tc-99m-MIBI before any treatment. Images of the lesions were obtained at 20 min and 2 h after radionuclide administration. Visual semi-quantitative interpretation was performed for Tc-99m-MIBI (grade 0-4) scintigraphy. Patients underwent 3-5 cycles of CHOP chemotherapy with/without involved field radiotherapy for large tumors. Their responses to treatment were evaluated at the end of chemotherapy and during the follow-up period. Forty of 45 patients (89%) showed abnormal uptake of Tc-99m-MIBI. There was no correlation between intensity of MIBI accumulation and response to chemotherapy. However, patients with negative or decreased MIBI activity 2 h after radionuclide administration showed worse response to chemotherapy compared to those with continued MIBI activity. MIBI activity could not predict the development of relapse in the follow-up study. In this study, the number of patients was small and we could not reach definite conclusions. However, we think that MIBI scintigraphy is not valuable for predicting the chemotherapy outcome in patients with NHL.