Efficiance of radioiodine remnant ablation in cases of locally differentiated thyroid cancer

Abstract

On the territory of Russia has increased the of thyroid cancer after Chernobyl NPP incidence at 1986, and currently accounts for up to 14,000 newly identified cases. Postoperative radioiodine (RAI) remnant ablation is the second stage of combine treatment of differentiated thyroid cancer, except for the prevalence of pT1N0M0, with minimal level of TG and AT-TG, according to international guidelines. In the past 20 years a significant number of published practice guidelines for the treatment of this disease. However, the discussion is the amount of medication for administration activity (GBq) 131I, is required for successful ablation of thyroid remnants. The study analyzed 353 clinical cases after radical surgical treatment for DTC. In our study, the effectiveness of radioiodablation was compared with certain indicators of specific therapeutic activity 131I (MBq/kg), in groups of patients with different levels of TSH stimulation (less than 30 mME/ml, and more than 30 mME/ml). We evaluated the absorbed dose in the thyroid remnant in patients with residual thyroid tissue volume determined by US when administering 131I empirical therapeutic activity. The control of the WBS with 131I was carried out in 6 months. The average eղciency RAI was 85.5 %, there were no significant differences in the TSH stimulation groups of more than 30 mME/ml and 4-30 mME/ml (p > 0.05). If the thyroid remnant is not detected by US, the effective range of 131I specific therapeutic activity is 30-40 MBq/ kg against a background of TTG stimulation greater than 4 ՏME/ml and strict adherence to a 14-day low iodine diet. Direct radiometry followed by neck scintigraphy (1200 kBq 131I) and calculation of therapeutic activity is recommended when determining thyroid remnant by US to plan for TAD = 300 Gy and reduce the risk of radiation sialoadenitis. At the time of RAI, 3.9 % of patients had previously undetectable X-rays lung metastases with stimulated TG levels greater than 124 ng/mL after surgical treatment with SPECT/CT.