Efficacy and Affecting Factors of 131I Thyroid Remnant Ablation After Surgical Treatment of Differentiated Thyroid Carcinoma

Clinicopathological features affecting the efficacy in 131I ablation therapy of papillary thyroid carcinoma with lymph node metastasis

Background

Lymph node metastasis is the major cause of increased recurrence and death in patients with papillary thyroid carcinoma (PTC). We evaluate the clinicopathologic factors affecting excellent response (ER) in patients with PTC with lymph node metastasis following operation and 131I ablation therapy.

Methods

A total of 423 patients with PTC with lymph node metastasis who underwent thyroidectomy and postoperative 131I ablation therapy were enrolled. The relationship between clinicopathological factors affecting ER achievement was analyzed.

Results

Multivariate analysis showed that the foci diameter (≤1 cm), unifocal, combination with Hashimoto's thyroiditis (HT), lymph node metastases rate (LR) (≤40%), no postoperative lymph node metastasis, low preablative stimulated thyroglobulin (ps-Tg) level (≤3.87 ng/mL), and the time of 131I ablation therapy (one time) were positively correlated with the ER achievement [odds ratio (OR): 1.744, 3.114, 3.920, 4.018, 2.074, 9.767, and 49.491, respectively; all p < 0.05]. The receiver operating characteristic (ROC) curves showed that the cutoff values of ps-Tg and LR were 4.625 ng/mL and 50.50%, respectively. The AUC of ROC of ps-Tg and LR for predicting ER achievement was 0.821 and 0.746, respectively. The Tg and the cumulative risk of non-ER elevated with the increase of LR, especially for the high-level ps-Tg (>4.625 ng/mL) group.

Conclusion

The foci diameter and number, combination with HT, LR, and ps-Tg level are independent factors for ER. Ps-Tg level and LR are valid predictive factors for the efficacy of 131I therapy in patients with PTC. The predictive value of the cumulative risk of non-ER can be improved by the combination of ps-Tg and LR.

A novel nomogram integrated with preablation stimulated thyroglobulin and thyroglobulin/thyroid-stimulating hormone ratio to predict the therapeutic response of intermediate‑ and high‑risk differentiated thyroid cancer patients: a bi-center retrospective study

PURPOSE

To investigate the factors influencing the outcome of radioactive iodine (RAI) treatment in intermediate- to high-risk patients with differentiated thyroid carcinoma (DTC).

METHODS

We enrolled 553 DTC patients who underwent total thyroidectomy and categorized them into two groups according to their response to RAI therapy: excellent response (ER) and non-ER groups. Clinical and pathological characteristics of the patients were collected and retrospectively analyzed using univariate and multivariate binary logistic regression. Receiver operating characteristic (ROC) curves and diagnostic cutoff values were analyzed to assess the predictive value of important quantitative influences on 131I treatment outcomes. A new nomogram model was developed based on the above independent risk factors. R software was used to develop nomograms with all the independent prognostic factors included.

RESULTS

The multivariate analysis showed that lymph node metastasis (LNM), stimulated thyroglobulin (sTg), thyroglobulin antibodies (TgAb), and sTg/thyroid-stimulating hormone (TSH) were significantly associated with non-ER of DTC patients. In the training set, the consistency index (C-index) of the new column line graph was 0.868 (95% CI 0.865-0.871).

CONCLUSION

We proposed a new nomogram to predict non-ER for DTC with excellent discrimination and calibration.

Development of a predictive nomogram for intermediate-risk differentiated thyroid cancer patients after fixed 3.7GBq (100mCi) radioiodine remnant ablation

Objectives

The objective of this study was to develop a predictive nomogram for intermediate-risk differentiated thyroid cancer (DTC) patients after fixed 3.7GBq (100mCi) radioiodine remnant ablation (RRA).

Methods

Data from 265 patients who underwent total thyroidectomy with central lymph node dissection (CND) and received RRA treatment at a single institution between January 2018 and March 2023 were analyzed. Patients with certain exclusion criteria were excluded. Univariate and multivariate logistic regression analyses were performed to identify risk factors for a non-excellent response (non-ER) to RRA. A nomogram was developed based on the risk factors, and its performance was validated using the Bootstrap method with 1,000 resamplings. A web-based dynamic calculator was developed for convenient application of the nomogram.

Results

The study included 265 patients with intermediate-risk DTC. Significant differences were found between the ER group and the non-ER group in terms of CLNM>5, Hashimoto's thyroiditis, sTg level, TgAb level (P < 0.05). CLNM>5 and sTg level were identified as independent risk factors for non-ER in multivariate analysis. The nomogram showed high accuracy, with an area under the curve (AUC) of 0.833 (95% CI = 0.770-0.895). The nomogram's predicted probabilities aligned closely with actual clinical outcomes.

Conclusions

This study developed a predictive nomogram for intermediate-risk DTC patients after fixed 3.7GBq (100mCi) RRA. The nomogram incorporates CLNM>5 and sTg levels as risk factors for a non-ER response to RRA. The nomogram and web-based calculator can assist in treatment decision-making and improve the precision of prognosis information. Further research and validation are needed.

Male Sex Is Not a Risk Factor for Prognosis in Postoperative Thyroid Cancer Patients: A Propensity Score Matching Study

PURPOSE

To study whether male sex is a risk factor for prognosis in patients with differentiated thyroid cancer after 131I treatment using the propensity score matching (PSM) method.

METHODS

From April 2016 to October 2021, 1948 postoperative differentiated thyroid cancer patients aged 43 (interquartile range: 34, 54) years who received 131I treatment were retrospectively enrolled and divided into male (n = 645) and female groups (n = 1303). The PSM method was adopted to process all data to reduce the influence of data bias and confounding variables. The Mann-Whitney U test and χ2 test were used for data analysis. Multivariate logistic regression was used to analyze the risk factors affecting prognosis, and the receiver operating characteristic curve was used to analyze the relationship between stimulated thyroglobulin (sTg) level, 131I dose, and poor prognosis.

RESULTS

Before PSM, the proportion of male patients with poor prognosis was significantly higher than that of female patients. After PSM, there was no difference in the proportion of poor prognosis between male and female groups. Multivariate logistic regression analysis showed that male sex; high T stage, N1b stage, and M1 stage; high sTg level; and high 131I dose were risk factors for poor prognosis before PSM. After PSM, high T stage, M1 stage, high sTg level, and 131I dose were still risk factors but male sex was no longer a risk factor for poor prognosis.

CONCLUSIONS

After the reduction of selection bias by PSM, male sex was no longer a risk factor for prognosis after 131I treatment of differentiated thyroid cancer. In addition, high T stage (T3 + T4 stage), M1 stage, sTg ≥10.15 ng/mL, and 131I dose ≥260 mCi were risk factors for poor prognosis.

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

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.

Comparing the efficacy of thyroglobulin and thyroglobulin/ thyroid-stimulating hormone ratio models in predicting a successful response to radioactive iodine therapy

BACKGROUND

The thyroglobulin (Tg)/ thyroid-stimulating hormone (TSH) ratio has manifested to be a reliable marker for predicting prognosis in patients with differentiated thyroid carcinoma (DTC). The objective of this study was to compare the efficacy of Tg and Tg/TSH ratio models in predicting a successful response to radioactive iodine therapy.

METHODS

One thousand six hundred forty-two DTC patients receiving ¹³¹I radiotherapy were finally enrolled in this retrospective study. The patients were divided into a training set (n = 973) and a validation set (n = 669) by the patient consultation time (July 2019). A receiver-operating characteristic curve was constructed for Tg and the Tg/TSH ratio to establish their cutoffs. Then, the variables were screened by univariate logistic regression and incorporated into logistic prediction models by stepwise regression, where Tg/TSH was excluded from model 1 and Tg was excluded from model 2.

RESULTS

In 1642 enrolled DTC patients, the first ¹³¹I radiotherapy had an excellent response in 855 patients. The cut-offs for Tg level and Tg/TSH ratio were 3.40 ng/ mL [area under the curve (AUC): 0.789] and 36.03 ng/mIU (AUC: 0.788), respectively. In addition, the AUC of the model including Tg was higher than that of the model including Tg/TSH in both the training set (0.837 vs 0.833) and the testing set (0.854 vs 0.836).

CONCLUSIONS

Both Tg and Tg/TSH ratios could be considered predictors of the effects of the first ¹³¹I ablative therapy. However, the prediction model including Tg performed better than the model including Tg/TSH.

Clinical Efficacy of Levothyroxine Sodium plus I 131 in the Treatment of Patients with Thyroidectomy and Its Effect on the Levels of Thyroglobulin and Thyrotropin

Objective

This study was to evaluate the clinical efficacy of levothyroxine sodium tablets combined with I 131 in the treatment of patients after thyroidectomy and the effect on thyroglobulin (Tg) and thyroid stimulating hormone (TSH) levels.

Methods

80 patients with differentiated thyroid cancer who required thyroidectomy after surgery between July 2019 and January 2021 were recruited for prospective study, 40 patients in the control group received levothyroxine sodium tablets, and 40 patients in the experimental group received levothyroxine sodium treatment plus I 131 treatment. Treatment effect, serum Tg and TSH levels, and relapse were measured.

Results

The removal rate of residual thyroid tissue in the experimental group (87.50%) was significantly higher than that in the control group (57.50%) (P < 0.05). Levothyroxine sodium tablets plus I 131 was associated with a significantly higher efficacy versus levothyroxine sodium tablets (P < 0.05). There were no significant differences in the serum Tg levels between the two groups before treatment (P > 0.05). After treatment, the serum Tg levels in both groups were significantly decreased, and levothyroxine sodium tablets plus I 131 resulted in a significantly lower Tg level versus levothyroxine sodium tablets (P < 0.05). Before treatment, the two groups showed similar TSH levels (P > 0.05). After treatment, patients receiving levothyroxine sodium tablets plus I 131 had a significantly greater increase in the TSH levels versus levothyroxine sodium tablets (P < 0.05). The recurrence rate of the experimental group was lower than that of the control group (P < 0.05).

Conclusion

Levothyroxine sodium tablets plus I 131 for post-operative patients with differentiated thyroid cancer enhance the removal rate of residual thyroid tissue, effectively reduce serum Tg level, and increase TSH level, with significant therapeutic effects, low recurrence rates, and a high safety profile.

Combination of Stimulated Thyroglobulin and Antithyroglobulin Antibody Predicts the Efficacy and Prognosis of 131I Therapy in Patients With Differentiated Thyroid Cancer Following Total Thyroidectomy: A Retrospective Study

BACKGROUND AND PURPOSE

This study aimed to analyze the diagnostic ability of the combination of stimulated thyroglobulin (sTg) and antithyroglobulin antibody (TgAb) in predicting the efficacy and prognosis of radioactive iodine (¹³¹I) therapy (RAIT) in patients with differentiated thyroid carcinomas (DTCs) after total thyroidectomy (TT).

METHODS

This retrospective study comprised 409 DTC patients who underwent ¹³¹I treatment following TT in the First Affiliated Hospital of Zhengzhou University from January 2019 to August 2020, and they were followed up to November 2021. Patients were divided into the successful ablation and the unsuccessful ablation group based on the classification of the efficacy of RAIT in the 2015 American Thyroid Association guidelines. The clinical characteristics and the efficacy of the initial RAIT were evaluated. The cutoffs of preablation sTg, sTg/thyroid-stimulating hormone (TSH) ratio, and sTg×TgAb product were calculated to predict the efficacy of RAIT. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors for unsuccessful ablation. Kaplan-Meier curves were used to estimate the prognostic value of sTg×TgAb product affecting progression-free survival (PFS).

RESULTS

The cohort consisted of 222 cases in the successful ablation group and 187 cases in the unsuccessful ablation group. Between the two groups, preablation sTg, sTg/TSH ratio, and sTg×TgAb product were significantly higher in the unsuccessful ablation group. The area under the curve (AUC) of the sTg×TgAb product was the highest among the above three factors. The cutoffs for the worse therapeutic effect of the initial RAIT in sTg, sTg/TSH ratio, and sTg×TgAb were >2.99 ng/ml, >0.029 mg/IU, and >34.18, respectively. STg >2.99 ng/ml and sTg×TgAb product >34.18 were independent risk factors for unsuccessful ablation. Patients with sTg×TgAb product >34.18 had shorter PFS than that of patients with sTg×TgAb product ≤34.18. In separate analyses of TgAb-negative and TgAb-positive subgroups, higher sTg×TgAb was both associated with a lower success rate of RAIT and a shorter PFS.

CONCLUSION

STg×TgAb product predicted the efficacy and prognosis of ¹³¹I therapy for both TgAb-negative and TgAb-positive DTC patients before the initial ¹³¹I treatment following TT. Thus, it can be used as a clinical reference indicator for the surveillance of DTC patients.