ACCUMULATION OF TC-99M-GLUTATHIONE IN HEAD AND NECK TUMORS

Glutathione labelled with Tc-99m was used to study blood clearance and normal distribution in 3 healthy volunteers and in 10 patients with b iopsy-proven tumors in the head and neck region. Static scintigrams we re obtained at 1, 3, 6, and 24 h. ROls over tumors and normal soft tis sues were compared to obtain T/N ratios. In normal subjects blood clea rance reached a plateau at 6 h; no radioactivity accumulation in the h ead and neck region was observed. Only the cardiac blood pool, the liv er, the kidneys and the urinary bladder were evident. Excretion was vi a the kidneys. Malignant tumors and metastases were well visualized in 7 patients (true-positive), starting at 1 h. The mean T/N ratio was 2 .69 +/- 0.77. The best images were obtained at 3-6 h. 1 false-positive (granulamatous reaction), 1 false-negative (malignant epithelial tumo r in the radix of tongue) and 1 true-negative (angiofibroma) results w ere obtained. Tc-99m-GSH is a potential radiopharmaceutical for the sc intigraphic visualization of head and neck tumors. Further clinical st udies are warranted to show its sensitivity and accuracy.