SURVEILLANCE POSTOPERATOIRE DES EPITHELIOMAS THYROIDIENS DIFFERENCIES. APPORT DU DOSAGE ULTRA-SENSIBLE DE LA TSH

Ultra-sensitive TSH assays were performed, using Behring's kit (sensitivity: 0.03 μU/ml), in 183 patients operated upon for differentiated thyroid carcinoma and followed up while under treatment with L-thyroxine. Clinically, all patients were euthyroid. TSH was undetectable in 38 patients and within normal limits in 93. A negative correlation was found between the logarithm of thyroxine plasma levels and that of TSH levels, but there were many discrepancies (normal thyroxine level with undetectable TSH, high thyroxine level with normal TSH level). This study shows that the ultra-sensitive TSH assay provides accurate information on the inhibition of TSH secretion. Clinical evaluation and plasma thyroxine assays are needed to make sure that the patient is in an euthyroid state.