ABSTRACT
Radioiodine (131I) therapy for differentiated thyroid cancer (DTC) involves exposure of the whole body, including the heart, to ionizing radiation. This exposure to the subsequent risk of heart disease is uncertain, especially in patients with DTC associated with type 2 diabetes mellitus (DTC/+T2DM). The current study aimed to assess the relationship between left ventricular ejection fraction (LVEF), high cumulative 131I dose, and peripheral blood parameters in patients with DTC/−T2DM and DTC/+T2DM. The study enrolled 72 female patients with DTC/−T2DM and 24 with DTC/+T2DM who received cumulative 131I doses above 150 mCi (5.55 GBq). LVEF was lower in patients with concomitant T2DM than those without (p < 0.001). The cumulative 131I dosage was inversely correlated with LVEF only in DTC/−T2DM patients (r = −0.57, p < 0.001). In the DTC/+T2DM group, LVEF was negatively associated with absolute platelet count (r = −0.67, p < 0.001) and platelet-to-lymphocyte ratio (r = −0.76, p < 0.001). Our results demonstrate that exposure to high cumulative 131I doses has different cardiovascular effects in DTC/−T2DM and DTC/+T2DM.
ABSTRACT
Publications investigating the effect of radioactive iodine (131I) therapy on the circulating peripheral blood cells in patients with differentiated thyroid cancer (DTC) are limited to blood samples collected more than 92 h after 131I. Studies conducted on blood samples collected up to 92 h are rare due to the radioactive contamination risk. This research aimed to assess the relationship between the prescribed 131I activity, human whole blood activity, and peripheral blood cells at many time points (6, 22, 46, 69, and 92 h after 131I). The study enrolled 50 female patients with DTC who received a 131I median activity of 90.54 mCi (3.35 GBq). The neutrophil-to-lymphocyte ratio (NLR) was measured as an inflammatory marker. 131I uptake in the residual thyroid tissue peaked after 46 h. Blood activity decreased in the first 46 h and increased 69 h after the 131I intake. Blood activity was associated with the absolute lymphocyte count and the NLR at 69 h (r = −0.49 and r = 0.52, p < 0.001). Our results demonstrate that the time interval between 46 and 69 h should be associated with the release of hematological inflammatory mediators, such as neutrophils and lymphocytes, to eradicate tumor cells in response to 131I therapy.
ABSTRACT
Autoimmune thyroiditis (AIT) may impair radioiodine (131I) uptake in papillary thyroid cancer (PTC). Finding the mechanisms that govern immune cells during 131I therapy of PTC with concomitant AIT (PTC + AIT) could provide a rationale. Our study aimed to evaluate the effects of 131I on anti-thyroglobulin antibodies (TgAb), matrix metalloproteinase-9 (MMP-9) and its tissue inhibitor TIMP-1 and tumor necrosis factor-α (TNF-α) and its receptors TNFR1 and TNFR2, in PTC and PTC + AIT patients. Peripheral blood was collected from 56 female patients with PTC and 32 with PTC + AIT before and 4 days after 131I (3.7 GBq). The serum levels of TgAb, MMP-9, TIMP-1, TNF-α, TNFR1 and TNFR2 were measured by ELISA. The mean radioactivity of blood samples collected after 131I intake was higher in the PTC + AIT group than in PTC (p < 0.001). In the PTC + AIT group, TNF-α/TNFR1 and TNF-α/TNFR2 ratios decreased by 0.38-fold and 0.32-fold after 131I and were positively correlated with the MMP-9/TIMP-1 ratio (r = 0.48, p = 0.005, and r = 0.46, p = 0.007). In the PTC group, TNF-α/TNFR1 and TNF-α/TNFR2 ratios increased by 3.17-fold and 3.33-fold and were negatively correlated with the MMP-9/TIMP-1 ratio (r = -0.62, p < 0.001 and r = -0.58, p < 0.001). Our results demonstrate that TNF-α may exert different antitumor effects in response to 131I therapy depending on the patient's immune profile.
