CT screening of thyroid nodules is a highly sensitive test for early diagnosis of MTC, but confirmatory stimulation testing is necessary in most cases to identify true positive increases.

Persistent or recurrent disease is rare in low risk patients with papillary thyroid cancer, and follow-up of these patients is a matter of debate. Neck ultrasonography (US), serum thyroglobulin (Tg), and whole body scan (WBS) after T(4) withdrawal were performed in 456 patients, followed up to 5 yr. At the end of the first year, 335 patients were Tg negative, and 121 were Tg positive; 65 of 96 patients with Tg levels between 1 and 10 ng/ml became spontaneously Tg negative after 2 yr. During follow-up, WBS discovered node metastases in 13 subjects, and US discovered node metastases in 38 subjects (31 Tg positive and 7 Tg negative). WBS did not add any information, because all WBS-positive patients were also US and Tg positive. Fifty percent of metastases were less than 1 cm and not palpable. Finally, the negative predictive value of both negative Tg and US at first follow-up was 98.8%. We suggest a first follow-up based upon US assessment and stimulated (after T(4) withdrawal or recombinant human TSH) serum Tg determination; subsequently, 1) US should not be mandatory at each examination in initially Tg- and US-negative subjects, but is strongly suggested in all other cases; 2) Tg determination should be repeated 1 yr later, after exogenous or endogenous TSH stimulation only in initially Tg-positive patients without any other evidence of residual disease; and 3) Tg measurement during therapy should be sufficient in all other cases.

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. Design: 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 # 1 ng/ml in 78 patients (Tg2 ) 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.

Accurate risk stratification can allow safe follow-up of most PTMC patients with a less intensive, more cost-effective protocol. Cervical ultrasonography is the mainstay of this protocol, and negative findings at the first postoperative examination are highly predictive of positive outcomes.