[Can benign and malignant thyroid nodules be differentiated with thallium 201?].

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