The significance of clinic-diagnostic factors in the course of estimation of side exposure of differentiated thyroid cancer patients after radioiodine therapy
Authors:   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Khvostunov I.K. , Krylov V.V. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Rodichev A.A. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Shepel N.N. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Korovchuk O.N. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Kochetova T.Yu. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Pyatenko V.S. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC),   N.M. Emanuel Institute of Biochemical Physics of RAS, Khvostunova T.I. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC), Zhironkina A.S. ,   A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation (A. Tsyb MRRC)
Published: June 2021

The radioiodine therapy is the most well-known branch of radionuclide therapy. The therapy composed of thyroidectomy and iodine-131 radiopharmaceutical is the “gold standard” for treat-ment of differentiated thyroid cancer patients (DTC). Given metastases in lymph nodes such therapy is absolutely exclusive treatment mode. At the same time, despite the targeted effect of radioiodine on pathological foci a side internal exposure of healthy organs and tissues is noted in the course of radioiodine therapy. Therefore, a reliable assessment of the side exposure is nec-essary taking into account the individual characteristics of patients considering that the side dose varies significantly from patient to patient. For this reason, the identification of significance of personal clinic-diagnostic factors determined the side whole body exposure is the vital and im-portant task. In this aspect, the cytogenetic examination of DTC patients by means of the analysis of chromosomal aberrations in peripheral blood lymphocytes is the goal of essential importance. The certain types of chromosomal aberrations are specific radiation markers that unequivocally indicate radiation exposure. Using the frequency of radiation markers the side absorbed dose can be reliably estimated. In the present work, the statistical analysis of the significance of vari-ous clinic-diagnostic factors in relation to the induction of radiation markers in the blood lympho-cytes was performed. For that end the results of the cytogenetic examination of the group com-prised of 38 DTC patients have been used. The examined patients underwent a course of radio-iodine therapy in the department of radionuclide therapy of the A.F. Tsyb MRRC, Obninsk. The slide preparation and cytogenetic analysis were carried out in the laboratory of radiation cytoge-netic of the same Center. The performed analysis of the correlation matrix with respect to the dependence of the increased frequency of stable and unstable markers resulted from a one-time course of radioiodine therapy showed no meaningfulness at the level R>0.3 for all the studied factors. For the absolute value of the frequency of radiation markers, both before and after radioiodine therapy, the meaningful relationship was found at the level R>0.7 for unsta-ble and at the level R>0.8 for stable markers with a total administered activity of radioiodine dur-ing all the previous courses of radioiodine therapy.