A NEW APPROACH TO THE DEFINITION OF LATENT METASTASIS OF
DIFFERENTIATED THYROID CANCER
Pyatnitsky I.A.1,2, Pyatnitsky A.M.3, Belyaev A.S.1, Volik D.N.1, Donskoy M.A.1
1 – Moscow International Oncological Center, European Medical Center.
2 - S.S. Yudin City Clinical Hospital Oncological Center No. 1 Moscow Department of Health.
3 –N.I. Pirogov Russian National Research Medical University Ministry of Health of the Russian Federation. Moscow, Russia.
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Purpose. To establish the role and relationship of scintigraphy with Tc99m-Pertechnetate with the threshold value of endogenously stimulated thyroglobulin in determining the spread of DTC before radioiodine therapy.
Materials and methods. In 294 patients with differentiated thyroid cancer who received the first course of radioiodine therapy, the dependence between the level of endogenously stimulated thyroglobulin and the presence of the spread of the tumor process was analyzed using mathematical statistics. Before radiotherapy, all patients included in the study had no thyroid residue on whole-body scintigraphy with Ts99m-Pertechnetate. The prevalence of the process was judged by ultrasound, X-ray and radionuclide examination data before radiotherapy and during 6 months of catamnestic observation.
Results. In 260 cases, progression or recurrence of thyroid cancer was not detected. Widespread thyroid cancer was detected in 34 patients: in 27 cases metastases to regional lymph nodes, in 7 patients a combination of regional and distant metastasis. When determining cancer markers of thyroid cancer in 142 patients, there was no significant expression of AT-TG (the level of AT-TG did not exceed the sensitivity limit of the method at 4.1 IU/ml), in 129 patients the range of AT-TG was 4.11-159 IU/ml, the level of AT-TG over 160 IU/ml was recorded in 23 cases.
Discussion. Due to the fact that the accuracy of thyroglobulin determination decreases with an increase in the AT-TG titer, the value of AT-TG equal to 160 IU/ml was chosen as the threshold value separating the high titer of antibodies from the low ones, and 8 ng/ml as the discriminating threshold for thyroglobulin.
Conclusion. It was found that for AT-TG <160 IU/ml, the thyroglobulin threshold value of 8 ng/ml effectively discriminates against the causes of absence and existence metastases with a specificity of 0.98 (95% percentage acceptable interval (0.95; 0.99)) and sensitivity=1.0 (95% acceptable interval (0.86; 1.00).
Keywords: radioiodine therapy, thyroglobulin, antibodies to thyroglobulin, thyroid cancer, scintigraphy, technetium.
Corresponding author: Pyatnitsky I.A., e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript
For citation: Pyatnitsky I.A., Pyatnitsky A.M., Belyaev A.S., Volik D.N., Donskoy M.A. A new approach to the definition of latent metastasis of differentiated thyroid cancer. REJR 2024; 14(4):31-40. DOI: 10.21569/2222-7415-2024-14-4-31-40.
Received: 30.09.24 Accepted: 20.11.24