An enhanced treatment effect can be expected from a higher serum thyroglobulin level after radioactive iodine therapy
- 39 Downloads
The aim of this study was to investigate if increased serum thyroglobulin (Tg) levels after radioactive iodine (RAI) showed more therapeutic effects in patients with differentiated thyroid cancer (DTC).
Data of 65 patients with DTC who underwent RAI from June 2014 to September 2016 were reviewed. Serum thyroglobulin was measured immediately before (Tg1) and 48 h (Tg2) after RAI under TSH stimulation. Differences and ratios between serum Tg measurements (DeltaTg = Tg2 − Tg1 and RatioTg = Tg2/Tg1) were calculated. The treatment response of distant metastasis was assessed using the RECIST criteria.
There was no difference in the median values of Tg1 and Tg2 (2.6 [range, 0.7–1957.5] ng/mL vs. 7.4 [range, 0.7–5276.0] ng/mL, p = 0.240) in all patients (73 scans, 65 patients). In subgroup analysis, Tg levels increased slightly in patients with distant metastasis (8 scans, 7 patients) (Tg1 vs. Tg2; 48.9 [range, 2.4–1957.5] ng/mL vs. 63.2 [range, 4.4–5276.0] ng/mL, p = 0.408). Among patients with distant metastasis, one patient with a partial response to treatment had a more than 4000fold increase in Tg levels and one patient with stable disease showed a 20fold increase in Tg levels. In contrast, five patients with disease progression showed only two to eightfold increase or more than 100fold decrease in Tg levels at 48 h after RAI. However, there was a significant increase in serum Tg levels in patients without distant metastasis (65 scans, 58 patients) after RAI (Tg1 vs. Tg2; 2.0 [range, 0.7–141.9] ng/mL vs. 6.8 [range, 0.7–577.7] ng/mL, p = 0.026).
A higher elevation of Tg levels after RAI may be associated with a better treatment outcome in DTC patients with distant metastasis. An increase in Tg levels after RAI may reflect the destruction of cancer and thyroid cells.
KeywordsDTC Metastasis Serum thyroglobulin Neck-to-skull ratio Treatment response
- 3.Webb RC, Howard RS, Stojadinovic A, Gaitonde DY, Wallace MK, Ahmed J, et al. The utility of serum thyroglobulin measurement at the time of remnant ablation for predicting disease-free status in patients with differentiated thyroid cancer: a meta-analysis involving 3947 patients. J Clin Endocrinol Metab. 2012;97(8):2754–63.CrossRefGoogle Scholar
- 4.Toubeau M, Touzery C, Arveux P, Chaplain G, Vaillant G, Berriolo A, et al. Predictive value for disease progression of serum thyroglobulin levels measured in the postoperative period and after (131) I ablation therapy in patients with differentiated thyroid cancer. J Nucl Med. 2004;45(6):988–94.PubMedGoogle Scholar
- 6.Bernier MO, Morel O, Rodien P, Muratet JP, Giraud P, Rohmer V, et al. Prognostic value of an increase in the serum thyroglobulin level at the time of the first ablative radioiodine treatment in patients with differentiated thyroid cancer. Eur J Nucl Med Mol Imaging. 2005;32(12):1418–21.CrossRefGoogle Scholar
- 12.Choi JH, Moon H, Park J, Chang K, Byun BH, Lim I, et al. Long-term outcomes of differentiated thyroid cancer with bone metastasis and the prognostic factors. J Nucl Med. 2015;56(supplement 3):1224.Google Scholar
- 13.Choi JH, Moon H, Park J, Chang K, Byun BH, Lim I, et al. Long-term outcomes of differentiated thyroid cancer with only lung metastasis and the prognostic factors. J Nucl Med. 2015;56(supplement 3):1260.Google Scholar
- 22.Lang BHH, Woo YC, Chiu KWH. The percentage of serum thyroglobulin rise in the first-week did not predict the eventual success of high-intensity focussed ablation (HIFU) for benign thyroid nodules. Int J Hyperth. 2017;33(8):882–7.Google Scholar