CAN BENIGN AND MALIGNANT THYROID-NODULES BE DIFFERENTIATED WITH THALLIUM-201

The merits of Thallium 201 radionuclide scanning of the thyroid mentio ned as soon as 1976 by PALERMO have been confirmed in the 16 last stud ies published in the international literature. Over 1601 examinations, authors showed that any cold nodule (Tc 99 m or I 123) which preferen tially fixes Thallium 201 as compared to surround thyroid tissue must be operated since some of them are thyroid cancer carriers, some other s are carriers of a traditional follicular adenoma or Hurthle-cell ade noma, or a follicular adenoma associated with varied cell atypisms whi ch make difficult the diagnosis between benign and malignant nodules. The analysis of the results published show a 91.3 % sensitivity of thi s diagnosis test, all analysis methods being considered. In case of ne gative test, it allows eliminating the cancer risk by more than 97 % ( negative predictive value). Such an examination - as opposed to a cyto logy test on the isolated nodule only - is valid for any type of nodul e, being isolated, multiple or a multinodular goitre where the degener ation risk is close to, or even higher than, that of isolated nodules (4, 22).