PEI therapy for thyroid lesions.

PEI therapy has been applied clinically as a new treatment strategy for cystic lesions and autonomous functioning nodules of the thyroid. Some additional indications currently under consideration include cold benign tumors and inoperable advanced cancer of the thyroid, and postoperative recurrence ofGraves' disease. At our institution, we have treated 2323 patients with thyroid disease by PEI therapy from 1999 to 2001. PEI is usually administered under ultrasound guidance in cases of cystic lesions, and under color-Doppler guidance in cases of solid lesions of the thyroid, with the goal of attenuating tumor blood flow. In consequence, of the total 2323 cases who received PEI therapy at our hospital, 1989 (85.6%) were classified as showing an effective response (ER) or partial response (PR). There were no major complications, such as recurrent laryngeal nerve palsy, uncontrollable pain, bleeding, or thyrotoxicosis. Our results also emphasize the importance of the use of color-Doppler guidance for control of the injection volume of ethanol to the minimum required for completely attenuating the tumor vascularity.