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On-levothyroxine measurement of thyroglobulin is not a reliable test for the follow-up of patients at high risk for remnant/recurrent differentiated thyroid carcinoma
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Abstract
Material and methods: We retrospectively analysed the medical records of 26 high-risk DTC patients and compared the on-treatment and off-treatment Tg levels of these patients. All patients were anti-Tg negative. Using off-treatment measurement of Tg as the gold standard, the results of on-treatment measurement of Tg in the diagnosis of remnant/recurrent disease were analysed for sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV).
Results: The median serum Tg level under thyroid hormone suppressive therapy (on-treatment Tg) was 16.5 ng/ml and after withdrawal of thyroid hormone suppressive therapy (off-treatment Tg) was 95.0 ng/ml (P value = 0.001). In 6 patients (23%) the on-treatment Tg level missed the recurrence of the disease. Regarding the off-treatment Tg as the gold standard, the sensitivity, specificity, PPV and NPV of the on-treatment Tg measurement were 72.7%, 100%, 100%, and 40% respectively.
Conclusion: Normal serum Tg level without TSH-stimulation (on-treatment) is not diagnostically reliable in the follow-up of DTC patients with a high probability of residual/recurrent or metastatic disease.
Abstract
Material and methods: We retrospectively analysed the medical records of 26 high-risk DTC patients and compared the on-treatment and off-treatment Tg levels of these patients. All patients were anti-Tg negative. Using off-treatment measurement of Tg as the gold standard, the results of on-treatment measurement of Tg in the diagnosis of remnant/recurrent disease were analysed for sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV).
Results: The median serum Tg level under thyroid hormone suppressive therapy (on-treatment Tg) was 16.5 ng/ml and after withdrawal of thyroid hormone suppressive therapy (off-treatment Tg) was 95.0 ng/ml (P value = 0.001). In 6 patients (23%) the on-treatment Tg level missed the recurrence of the disease. Regarding the off-treatment Tg as the gold standard, the sensitivity, specificity, PPV and NPV of the on-treatment Tg measurement were 72.7%, 100%, 100%, and 40% respectively.
Conclusion: Normal serum Tg level without TSH-stimulation (on-treatment) is not diagnostically reliable in the follow-up of DTC patients with a high probability of residual/recurrent or metastatic disease.
Keywords
thyroid cancer; serum thyroglobulin; levothyroxine; recurrence
About this articleTitle
On-levothyroxine measurement of thyroglobulin is not a reliable test for the follow-up of patients at high risk for remnant/recurrent differentiated thyroid carcinoma
Journal
Issue
Article type
Original paper
Pages
100-104
Published online
2007-03-13
Page views
554
Article views/downloads
1060
Bibliographic record
Endokrynol Pol 2007;58(2):100-104.
Keywords
thyroid cancer
serum thyroglobulin
levothyroxine
recurrence
Authors
Ali Gholamrezanezhad
Mohsen Saghari
Sahar Mirpour
Davood Beiki
Ali Tarbiat
Shabnam Javan
Javaher Abdollahzadeh
