TSH ≥30 mU/L may not be necessary for successful 131I remnant ablation in patients with differentiated thyroid cancer

• Published in: European thyroid journal Vol. 12; no. 4; pp. 1 - 11
• Main Authors: Ju, Nianting, Hou, Liying, Song, Hongjun, Qiu, Zhongling, Wang, Yang, Sun, Zhenkui, Luo, Quanyong, Shen, Chentian
• Format: Journal Article
• Language: English
• Published: England Bioscientifica Ltd 01.08.2023; Bioscientifica
• Subjects: Adenocarcinoma - surgery; Apolipoproteins; Cholesterol; differentiated thyroid cancer; Humans; Iodine Radioisotopes; radioiodine therapy; Retrospective Studies; thyroglobulin; Thyroid Neoplasms; thyroid remnant ablation; thyroid-stimulating hormone; Thyroidectomy; Thyrotropin; thyroid-stimulating hormone; thyroid remnant ablation; radioiodine therapy; thyroglobulin; differentiated thyroid cancer
• ISSN: 2235-0802; 2235-0640; 2235-0802
• DOI: 10.1530/ETJ-22-0219

Purpose To determine whether thyroid-stimulating hormone level ≥ 30 mU/L is necessary for radioiodine (131I) remnant ablation (RRA) in patients with differentiated thyroid cancer (DTC), as well as its influencing factors and predictors. Methods A total of 487 DTC patients were retrospectively enrolled in this study. They were divided into two groups (TSH < 30 and ≥ 30 mU/L) and further divided into eight subgroups (0–<30, 30–<40, 40–<50, 50–<60, 60–<70, 70–<80, 80–<90, and 90–<100 mU/L). The simultaneous serum lipid level, successful rate of RRA and its influencing factors in different groups were analyzed. The receiver operating characteristic curves derived from pre-ablative thyroglobulin (pre-Tg) and pre-Tg/TSH ratio were compared for RRA success prediction performance. Results There was no statistical difference in success rates of RRA between the two groups (P = 0.247) and eight subgroups (P = 0.685). Levels of total cholesterol (P < 0.001), triglyceride (P = 0.006), high-density lipoprotein cholesterol (P = 0.024), low-density lipoprotein cholesterol (P = 0.001), apolipoprotein B (P < 0.001), and apolipoprotein E (P = 0.002) were significantly higher while apoA/apoB ratio (P = 0.024) was significantly lower at TSH ≥ 30 mU/L group. Pre-Tg level, gender, and N stage were influencing factors for RRA. The area under the curve of pre-Tg level and pre-Tg/TSH ratio was 0.7611 (P < 0.0001) and 0.7340 (P < 0.0001) for all enrolled patients and 0.7310 (P = 0.0145) and 0.6524 (P = 0.1068) for TSH < 30 mU/L, respectively. Conclusion TSH ≥ 30 mU/L may not be necessary for the success of RRA. Patients with higher serum TSH levels prior to RRA will suffer from severer hyperlipidemia. Pre-Tg level could be used as a predictor for the success of RRA, especially when TSH < 30 mU/L.