Control of completeness of thyroidectomy in patients with differentiated thyroid cancer by intraoperative radionavigation, influence on the tactics of subsequent radiotherapy

Purpose: to evaluate the potential of intraoperative radionavigation with 123I followed by radionuclide therapy with low activities in patients with differentiated thyroid cancer. Material and methods: the retrospective study of 150 cases (129 females, 21 males, age 20-60) of differentiated thyroid carcinoma treated with radical surgery and radioiodine therapy was conducted. In the main group radioiodine navigation control of the completeness of the surgery was performed. All patients were examined: laboratory examination (TSH, TG, AT-TG), ultrasound, scintigraphy with 99mTC-pertechnetate and post-therapeutic full-body scintigraphy with 131I sodium iodide, stimulation test in combination with scanning in the whole body with 123I 9 -12 months after radiation treatment. Results: a statistically significant difference between the selected groups in the level of TSH in the fourth week of induction of hypothyroidism was found (67.9 ± 28.5 mIU / l and 82.7 ± 29.7 mIU / l) (p = 0,014). There were also differences in TG levels before the radiofrequency ablation (4,9±5,6 and 1,1±3,3 ng / ml) ( р = 0,00007). This can be considered as a criterion for identifying 4 patients in whom radionuclide treatment can be abandoned when performing radio navigation in the absence of other risks of disease progression. The advantage of using a radioiodine navigation to control the completeness of thyroidectomy has been confirmed. Conclusion: thyroidectomy with intraoperative radioiodine navigation allows, in some cases, to abandon radioiodine therapy in favor of dynamic observation. It is possible to significantly (in 1.5 times) reduce the therapeutic activity of 131I without prejudice to the effectiveness of treatment and to avoid the second course of radionuclide therapy. The duration of induction of hypothyroidism before radioiodine therapy can be reduced to three weeks, provided that the level of TSH is monitored from the 14th day of suppression of hormone suppressant therapy