RESULTS OF SELECTIVE VENOUS CATHETERIZATI ON (SVC) IN OCCULT MEDULLARY-THYROID CARCINOMA

Background: Medullary thyroid carcinoma (MTC) can - even in recurrent cases - only be treated surgically. Therefore, preoperative localizati on of the tumor is essential. Methods: From April 1986 through April 1 997, 137 patients with MTC were operated on at our clinic. In 22 patie nts with recurrent tumor which had not been radiologically localized, 28 selective venous catheterizations (SVC) with determination of calci tonin levels were carried out. Results:In 23 examinations a suspected tumor could be identified (nine cervical unilateral, seven mediastinal , four cervical unilateral and mediastinal, one cervical bilateral and mediastinal, one liver, one cervical unilateral and liver). In 18 cas es surgery was performed for recurrence (nine cervical revisions, one mediastinal dissection, six cervicomediastinal dissections, two laparo tomies). In 15 of 18 cases, tumor tissue was found in the previously s uspected area. In ten cases serum calcitonin levels dropped postoperat ively by 6%-75%. A normalization of the hormone level was achieved onl y once by yet another operation. During further follow-up, five of the reoperated patients died from their disease. The other 17 patients ar e being followed up, whereby calcitonin levels are elevated but there is no clinical or radiological evidence of tumor. Conclusions: Althoug h in the patient cohort presented a normalization of serum calcitonin could be achieved only once, the authors consider SVC useful because i t is the only means of localization of tumor tissue in cases of negati ve radiologic studies and therefore allows a planned approach to the o peration procedure in these cases.