99mTc-pertechnetate thyroid scintigraphy in patients predisposed to thyroid neoplasms by prior radiotherapy to the head and neck.

Histories, physical examinations and 99mTc-pertechnetate imaging were used to evaluate 1,452 persons who had had x-ray therapy to the neck region for benign conditions 18 to 35 years previously. Thyroid abnormalities were found in 301 patients (21%) and thyroid malignancy was found in 29% of 193 patients with abnormal studies who were explored surgically. Thyroid imaging detected 96% of these abnormalities, 40% of which would not have been unequivocally established by physical examination alone. Nuclear imaging could not distinguish benign from malignant lesions.