The aim of the follow-up in differentiated thyroid cancer (DTC) is the early detection and treatment of persistent/recurrent disease. The large majority of local/distant recurrences are detected in the first 5 years of follow-up but in some cases even after 20 years after the intial treatment. This consists in total/near total thyroidectomy followed, when appropiate, by post-surgical thyroid radioiodine remnant ablation (RRA). This treatment was originally performed in hypothyroidism. After the the approval from FDA (Food and Drug Administration) and EMA (European Medicines Agency) of recombinant human TSH (rhTSH) for human use and its introduction in the clinical practice for the follow-up of DTC two large multicenter clinical trials (ESTIMABL and HILO) clearly demonstrated that RRA can be achived with the same efficacy in low and intermediate risk DTC patients with high (100 mCi) or low (30 mCi) radioiodine activity with the use of rhTSH avoiding thyroid hormone withdrawal. After 6-12 months from the initial treatment the patients should be followed with neck ultrasound (US), recombinant human TSH (rhTSH) stimulation test for serum thyroglobulin (Tg) measurement and in case of detectable anti-Tg antibodies (TgAb), a diagnostic whole body scan (WBS) can be performed. The patients are considered free of disease when serum Tg levels after rhTSH are less than 1 ng/ml, neck US is negative and TgAb undetectable or detectable but stable/decreasing during follow-up. In this setting and in the presence of a negative post-therapy WBS obtained at the time of thyroid remnant ablation, the patients free of disease have a very low risk (<1%) of recurrence at 10 years. More recently a new assay for the measurement of serum thyroglobulin with a functional sensitivity below 0.1 ng/ml was developed. For some authors this new method could avoid the need of performing rhTSH stimulation test in case of undetectable ultrsensitive basal Tg values (<0.1 ng/ml). However the high sensitivity of this test is at expenses of a very low specificity, infact, while patients with negative neck US and basal serum Tg <0.1 ng/ml may be considered free of disease, in the presence of a basal serum Tg between 0.1 and 1 ng/ml the test could not discriminate between the patients with presence or absence of the disease. In these cases rhTSH stimulation is still informative and could discriminate the patients with real disease in which stimlated serum Tg is more than 1 ng/ml.
New insights in the management of differentiated thyroid cancer.
ELISEI, ROSSELLA;VIOLA, DAVID
2013-01-01
Abstract
The aim of the follow-up in differentiated thyroid cancer (DTC) is the early detection and treatment of persistent/recurrent disease. The large majority of local/distant recurrences are detected in the first 5 years of follow-up but in some cases even after 20 years after the intial treatment. This consists in total/near total thyroidectomy followed, when appropiate, by post-surgical thyroid radioiodine remnant ablation (RRA). This treatment was originally performed in hypothyroidism. After the the approval from FDA (Food and Drug Administration) and EMA (European Medicines Agency) of recombinant human TSH (rhTSH) for human use and its introduction in the clinical practice for the follow-up of DTC two large multicenter clinical trials (ESTIMABL and HILO) clearly demonstrated that RRA can be achived with the same efficacy in low and intermediate risk DTC patients with high (100 mCi) or low (30 mCi) radioiodine activity with the use of rhTSH avoiding thyroid hormone withdrawal. After 6-12 months from the initial treatment the patients should be followed with neck ultrasound (US), recombinant human TSH (rhTSH) stimulation test for serum thyroglobulin (Tg) measurement and in case of detectable anti-Tg antibodies (TgAb), a diagnostic whole body scan (WBS) can be performed. The patients are considered free of disease when serum Tg levels after rhTSH are less than 1 ng/ml, neck US is negative and TgAb undetectable or detectable but stable/decreasing during follow-up. In this setting and in the presence of a negative post-therapy WBS obtained at the time of thyroid remnant ablation, the patients free of disease have a very low risk (<1%) of recurrence at 10 years. More recently a new assay for the measurement of serum thyroglobulin with a functional sensitivity below 0.1 ng/ml was developed. For some authors this new method could avoid the need of performing rhTSH stimulation test in case of undetectable ultrsensitive basal Tg values (<0.1 ng/ml). However the high sensitivity of this test is at expenses of a very low specificity, infact, while patients with negative neck US and basal serum Tg <0.1 ng/ml may be considered free of disease, in the presence of a basal serum Tg between 0.1 and 1 ng/ml the test could not discriminate between the patients with presence or absence of the disease. In these cases rhTSH stimulation is still informative and could discriminate the patients with real disease in which stimlated serum Tg is more than 1 ng/ml.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
