Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer.
OBJECTIVE
The 'standard' postoperative follow-up of patients with differentiated thyroid cancer (DTC) has been based upon serum thyroglobulin (Tg) measurement and (131)I whole body scan ((131)I-WBS) after thyroid hormone (T(4)) treatment withdrawal. However, (131)I-WBS sensitivity has been reported to be low. Thyroid hormone withdrawal, often associated with hypothyroidism-related side effects, may now be replaced by recombinant human thyroid stimulating hormone (rhTSH). The aim of our study was to evaluate the diagnostic accuracy of (131)I-WBS and serum Tg measurement obtained after rhTSH stimulation and of neck ultrasonography in the first follow-up of DTC patients.


METHODS
Ninety-nine consecutive patients previously treated with total thyroidectomy and (131)I ablation, with no uptake outside the thyroid bed on the post-ablative (131)I-WBS (low-risk patients) were enrolled.


METHODS
Measurement of serum Tg and (131)I-WBS after rhTSH stimulation, and ultrasound examination (US) of the neck.


RESULTS
rhTSH-stimulated Tg was <or=1 ng/ml in 78 patients (Tg-) and >1 ng/ml (Tg+) in 21 patients, including 6 patients with Tg levels >5 ng/ml. (131)I-WBS was negative for persistent or recurrent disease in all patients (i.e. sensitivity = 0%). US identified lymph-node metastases (confirmed at surgery) in 4/6 (67%) patients with stimulated Tg levels >5 ng/ml, in 2/15 (13%) with Tg >1<5 ng/ml, and in 2/78 (3%) who were Tg-negative.


CONCLUSIONS
(i) diagnostic (131)I-WBS performed after rhTSH stimulation is useless in the first follow-up of DTC patients; (ii) US may identify lymph node metastases even in patients with low or undetectable serum Tg levels.
Torlontano
Massimo
M
Unit of Endocrinology, Scientific Institute 'Casa Sollievo della Sofferenza', 71013 San Giovanni Rotondo, Foggia, Italy.
Crocetti
Umberto
U
D'Aloiso
Leonardo
L
Bonfitto
Nazario
N
Di Giorgio
Anna
A
Modoni
Sergio
S
Valle
Guido
G
Frusciante
Vincenzo
V
Bisceglia
Michele
M
Filetti
Sebastiano
S
Schlumberger
Martin
M
Trischitta
Vincenzo
V
D000328:Adult; D000368:Aged; D018265:Carcinoma, Papillary, Follicular / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D011994:Recombinant Proteins / Q000627:therapeutic use; D012307:Risk Factors; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D013972:Thyrotropin / Q000627:therapeutic use*; D014463:Ultrasonography
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D013972:Thyrotropin; D013954:Thyroglobulin