Evaluation of RI scintiscanning to parotid gland tumors

We retrospectively evaluated preoperative radioisotope (RI) scintiscans in 275 patients (283 glands) with parotid tumors who undergoing surgery between 1987 and 2000. Technetium-99m-pertechnetate (Tc) scintigraphy was conducted on 201 glands. Oncocytoma and Warthin's tumor showed a high positive rate. In evaluating Warthin's tumor with Tc scintigraphy, sensitivity was 75% and specificity 88%; above the age of 40 years, specificity exceeded 90%. Gallium-67-citrate (Ga) scintigraphy was conducted on 207 glands. Malignant parotid tumors showed high positivity (85%), but the specificity of positive findings was quite low (38%) because 44% of benign pleomorphic adenoma, which occupied major material, showed Ga-positive findings. Ga-negative findings indicated high probability (95%) of benign tumors. Thus, Tc scintigraphy is effective in diagnosing Warthin's tumor, while Ga scintigraphy is effective in diagnosing benign tumors.