Impact factors for the outcome of the first 131I radiotherapy in patients with papillary thyroid carcinoma after total thyroidectomy

Prognostic Analysis of 131I Efficacy After Papillary Thyroid Carcinoma Surgery Based on CT Radiomics

OBJECTIVE

To develop and validate a radiomics-clinical combined model combining preoperative computed tomography (CT) and clinical data from patients with papillary thyroid carcinoma (PTC) to predict the efficacy of initial postoperative 131I treatment.

METHODS

A total of 181 patients with PTC who received total thyroidectomy and initial 131I treatment were divided into training and testing sets (7:3 ratio). Univariate analysis and multivariate logistic regression were used to screen clinical factors affecting the therapeutic response to 131I treatment and construct a clinical model. Radiomics features extracted from preoperative CT images of PTCs were dimensionally reduced through recursive feature elimination and least absolute shrinkage and selection operator. Logistic regression was used to establish a radiomics model, and a radiomics-clinical combined model was developed by integrating the clinical model. The area under the curve (AUC), sensitivity, and specificity were used to evaluate the prediction performance of each model.

RESULTS

Multivariate analysis revealed that pre-131I treatment serum thyroglobulin was an independent clinical risk factor affecting the efficacy of initial 131I treatment (P = .002), and the AUC, sensitivity, and specificity for predicting the efficacy of initial 131I treatment were 0.895, 0.899, and 0.816, respectively. After dimensionality reduction, 14 key CT radiomics features of PTCs were included. The established radiomics model predicted the efficacy of 131I treatment in the training and testing sets with AUCs of 0.825 and 0.809, sensitivities of 0.828 and 0.636, and specificities of 0.745 and 0.944, respectively. The combined model improved the AUC, sensitivity, and specificity in both sets.

CONCLUSION

The preoperative CT-based radiomics model can effectively predict the efficacy of initial postoperative 131I treatment in patients with intermediate- or high-risk PTC, and the radiomics-clinical combined model exhibits better predictive performance.

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.

Combined clinical variable and radiomics of post-treatment total body scan for prediction of successful I-131 ablation in low-risk papillary thyroid carcinoma patients

To explore the feasibility of combined radiomics of post-treatment I-131 total body scan (TBS) and clinical parameter to predict successful ablation in low-risk papillary thyroid carcinoma (PTC) patients. Data of low-risk PTC patients who underwent total/near total thyroidectomy and I-131 ablation 30 mCi between April 2015 and July 2021 were retrospectively reviewed. The clinical factors studied included age, sex, and pre-ablative serum thyroglobulin (Tg). Radiomic features were extracted via PyRadiomics, and radiomic feature selection was performed. The predictive performance for successful ablation of the clinical parameter, radiomic, and combined models (radiomics combined with clinical parameter) was calculated using the area under the receiver operating characteristic curve (AUC). One hundred and thirty patients were included. Successful ablation was achieved in 77 patients (59.2%). The mean pre-ablative Tg in the unsuccessful group (15.50 ± 18.04 ng/ml) was statistically significantly higher than those in the successful ablation group (7.12 ± 7.15 ng/ml). The clinical parameter, radiomic, and combined models produced AUCs of 0.66, 0.77, and 0.87 in the training sets, and 0.65, 0.69, and 0.78 in the validation sets, respectively. The combined model produced a significantly higher AUC than that of the clinical parameter (p < 0.05). Radiomic analysis of the post-treatment TBS combined with pre-ablative serum Tg showed a significant improvement in the predictive performance of successful ablation in low-risk PTC patients compared to the use of clinical parameter alone.Thai Clinical Trials Registry TCTR identification number is TCTR20230816004 ( https://www.thaiclinicaltrials.org/show/TCTR20230816004 ).

Sufficiency of a Single Negative Thyroglobulin Standard for Judging the Success of Ablation in Low- and Intermediate-risk Differentiated Thyroid Cancer: A Retrospective Study

BACKGROUND

We investigated how reduced successful ablation criteria may be used to evaluate radioiodine remnant ablation in patients with low- and intermediate-differentiated thyroid carcinoma (DTC).

METHODS

Overall, 254 low- and intermediate-risk patients with DTC were categorized into three groups (positive, weak, positive, and negative) on the basis of a visual study of thyroid imaging performed before postoperative iodine treatment. Semi-quantitative analysis parameters were incorporated into the positive Tc-99m pertechnetate scanning to further examine the clinical use of thyroid imaging. We investigated the value of successful judgment criteria and the influencing factors of radioiodine ablation. At the same time, the predictive value of thyroglobulin (Tg) for radioiodine treatment and the overall clinical efficacy were assessed.

RESULTS

A total of 250 (98.43%) patients were identified as having functional thyroid tissue residue on the Rx-whole-body scan, and 137 (53.94%) patients had positive Tc-99m pertechnetate scans using semi-quantitative analysis. The single Tg standard could not substitute the double standard (χ2c=22.042, p<0.001) for patients with residual thyroid weight by a semiquantitative analysis. However, the semi-quantitative analysis revealed no association between 99mTcO4-thyroid scan and ablation treatment using semi-quantitative analysis; only preablation sTg levels were related with success in the multivariate logistic regression analysis, with a cut-off value of 2.88 ng/mL. The pre-ablation stimulated Tg level was also the primary factor of satisfactory response following follow-up with an optimal cut-off of 6.506 ng/mL.

CONCLUSION

Even in low- and intermediate-risk patients with DTC, a single negative Tg standard also requires receiving some restrictions in the evaluation of ablation success and is inadequate. Conventional 99mTcO4 thyroid imaging combined with a quantitative analysis program can improve the clinical practice of single negative Tg standard.

Papillary thyroid carcinoma with desmoid-type fibromatosis: the clinicopathological features with characteristic imaging and molecular correlation requiring comprehensive treatment

The pathogenesis and treatment of papillary thyroid cancer with desmoid-type fibromatosis (PTC-DTF), a rare subtype of papillary thyroid carcinoma characterized by a mixed epithelial-mesenchymal structure, are still ill-defined. Previous reports on PTC-DTF have had limited follow-up and recurrence has been rarely reported. To better understand this condition, we conducted a thorough analysis of five cases of PTC-DTF from our institute, including clinical and pathological examinations, imaging, immunohistochemistry, and molecular analysis. We also reviewed relevant literature. The mean age of the patients was 51.8 years, with three women and two men included in the group. Ultrasound often showed a hypoechogenic and well-defined nodule in the thyroid gland, except for one individual who had distant lung metastases detected by PET-CT. The nodules ranged in width from 0.5 to 5.0 cm and were excised in each case. Following surgery, ¹³¹I therapy was used in two cases. The overall number of PTC-DTF cases has risen from the previously reported 55 to 60, with females being the most commonly affected and ranging in age from 19 to 82. Most masses underwent a thyroidectomy, and approximately half of the patients had lymph node metastases. Histologically, PTC-DTFs were composed of a predominant stromal component (65% - 90%) and an intervening epithelial component. These spindle cells were arranged in parallel with abundant cytoplasm and vacuole-like nucleus but there wasn't evident atypia. The carcinoma cells were positively stained for CK and TTF-1 by immunohistochemistry, whereas mesenchymal cells were positive for SMA and displayed nuclear immunoreactivity for β-catenin. BRAF, NRAS, and CTNNB1 mutations were identified in the epithelial and mesenchymal components through molecular testing, respectively. Perhaps because the mesenchyme harbors aberrant nuclear β-catenin expression, PTC-DTF is more aggressive and prone to invasion and distant recurrence, as shown by our case 2, which is the first case to be reported thus far. PTC-DTF is typically treated with surgery, but clinicians may occasionally consider more holistic treatment plans that involve radioactive iodine and endocrine therapy.

Analysis of factors influencing the clinical outcome after surgery and 131I therapy in patients with moderate-risk thyroid papillary carcinoma

PURPOSE

Generally, the prognosis for papillary thyroid cancer (PTC) is favorable. However, the moderate risk involved warrants further evaluation. Hence, we investigated the clinical outcomes in patients with moderate-risk PTC following surgery and the first ¹³¹I therapy, as well as the relevant factors that influence the therapeutic efficacy.

METHODS

Retrospective analyses of 175 patients with medium-risk PTC who visited the Second Affiliated Hospital of Chongqing Medical University from September 2017 to April 2019 were conducted. In according with the 2015 American Thyroid Association (ATA) guideline treatment response evaluation system, the patients were categorized into the following groups: excellent response (ER), indeterminate response (IDR), biochemical incomplete response (BIR), and structurally incomplete response (SIR), of which IDR, BIR, and SIR were collectively referred to as the NER group. To compare the general clinical features between the 2 groups of patients, 2 independent samples t-tests, χ² test, and Mann-Whitney U-test were performed, followed by multivariate logistic regression analyses. With reference to the receiver operating characteristic (ROC) curve, the predicted value of ps-Tg to ER was evaluated, and the best cut-off value was determined. The subgroups with BRAF^V600E test results were analyzed by χ2 test only.

RESULTS

The treatment responses of 123 patients were ER, while those of 52 patients were NER. The differences in the maximum tumor diameter (U = 2495.50), the amount of metastatic lymph nodes (U = 2313.50), the size of metastatic lymph node (U = 2113.50), the metastatic lymph node ratio (U = 2111.50), metastatic lymph node location (χ² = 9.20), and ps-Tg level (U = 1011.00) were statistically significant. Multivariate regression analysis revealed that ps-Tg (OR = 1.209, 95% CI: 1.120-1.305) was an independent variable affecting ER. The cut-off value of ps-Tg for predicting ER was 6.915 ug/L, while its sensitivity and specificity were 69.2% and 89.4%, respectively.

CONCLUSIONS

Patients with smaller tumor size, fewer lymph nodes, lower metastatic lymph node ratio, metastatic lymph nodes in the central region, smaller lymph node size, and ps-Tg <6.915 ug/L demonstrated better therapeutic effects after the initial treatment.

The Role of Thyroglobulin in Preoperative and Postoperative Evaluation of Patients With Differentiated Thyroid Cancer

Thyroglobulin (Tg) is secreted by thyroid follicular cells and stored in the thyroid follicular lumen as a component of thyroid hormone. It is known that both benign and well-differentiated malignant thyroid tissue can secrete Tg. In recent years, growing lines of evidence have shown that Tg plays an important role in the diagnosis and metastasis of preoperative differentiated thyroid carcinoma (DTC). The levels of Tg, whether in the serum or in a fine-needle aspiration washout fluid, are usually viewed as an excellent indicator in the monitoring of postoperative DTC, including the guidance and evaluation of radioactive iodine ablation. Nevertheless, some factors limit the application of Tg, such as the method used to measure Tg and the presence of Tg antibodies. This review aimed to summarize the role of Tg in the preoperative and postoperative evaluation of patients with DTC, and the factors influencing Tg. This review could provide a reference for a more accurate application of Tg in patients with DTC.

Global Hotspots and Prospects of I-131 Therapy in Thyroid Carcinoma via Bibliometric Analysis

Background

Hundreds of studies have reported the application of iodine-131 (I-131) in thyroid carcinoma (THCA) in past years. However, the status of research in the field and other related topics have not been investigated. This study aimed to identify the cooperation of authors, countries, and institutions, as well as explore the hot topics and prospects regarding I-131 therapy in THCA based on previous studies.

Methods

Publications from 2010 to 2020 were retrieved from Web of Science Core Collection according to research strategy. Bibliometric analyses were performed using VOSviewer 1.6.15 and CiteSpace 5.7.3 to evaluate and visualize the cooperation network, hot topic, and research frontier.

Results

The number of publications showed a trend of fluctuation between 2010 and 2020. We identified 1387 publications related to I-131 therapy in THCA, which were published by 1628 institutions from 82 countries. The largest proportion of publications were emanated from the USA, and the majority of papers were published by Thyroid. Shanghai Jiao Tong University of China contributed the most papers. Although many authors participated in the research of this field, high-yield authors were few. Co-occurrence analysis classified keywords into five clusters, including assessment, efficacy measurement, monitoring, hormone regulation, and guidelines of I-131 therapy. The terms “bone marrow dosimetry and time” were among the latest hotspots. The research frontier topic in I-131 therapy focused on the “P53 and anti-Müllerian hormone”.

Conclusion

The attention to I-131 therapy in THCA should be increased considerably. It was necessary to construct active co-operations between authors, countries, and institutions to promote the development of this field. Recent researches referred to the timing and dose assessment of I-131 therapy in THCA. Future studies likely focused on targeted therapy and adverse effects evaluation were worthy of research as well.

Unexpected radioactive iodine accumulation on whole-body scan after I-131 ablation therapy for differentiated thyroid cancer

We retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation.

Deltex3 inhibits Epithelial Mesenchymal Transition in Papillary Thyroid Carcinoma via promoting ubiquitination of XRCC5 to regulate the AKT signal pathway

Background: Papillary thyroid carcinoma (PTC) is one of the most common endocrine malignant tumors. Poor prognoses such as high recurrence rate always appear in PTC patients with cervical lymph node metastasis. The process of ubiquitination plays important roles in PTC. As ubiquitin E3 ligases, Deltex (DTX) family proteins were reported to associate with multiple cancers. However, functions and mechanisms of DTX3 in PTC are currently unknown.

Methods: In this study, DTX3 expressions were examined in 114 PTC and paired paracancerous normal tissues through quantitative real-time polymerase chain reaction and western blot. The clinical significances of DTX3 expressions in PTC patients were also investigated. After stable transfection with either short hairpin RNA to knock down DTX3 expression or full-length complementary DNA to upregulate DTX3 expression, changes of malignant phenotypes in two PTC cell lines K1 and TPC-1 were observed using cell viability, flow cytometry, wound healing and transwell assays. Afterwards, altered expressions of epithelial-mesenchymal transition (EMT) and AKT signal pathway related proteins were measured by western blot. Immunoprecipitation and mass spectrometry (IP-MS), immunofluorescence and Co-IP were utilized to identify the possible DTX3 interacting proteins.

Results: Both mRNA and protein expressions of DTX3 were lower in PTC tissues and correlated with the presence of cervical lymph node metastasis (P<0.05). DTX3 overexpression inhibited migration and invasion of PTC cells, decreased Vimentin and phosphorylated AKT expressions, but promoted E-cadherin expression (P<0.05). Moreover, knockdown of DTX3 led to opposite changes (P<0.05). Total 46 probable DTX3 interacting proteins were identified by IP-MS. Among them, X-ray repair cross-complementing protein 5 (XRCC5) and NADH: Ubiquinone Oxidoreductase Complex Assembly Factor 5 (NDUFAF5) were verified to be associated with DTX3. Moreover, DTX3 was proved to be co-localized with XRCC5 in nucleus and promote ubiquitination of XRCC5.

Conclusions: DTX3 suppresses EMT by partially facilitating ubiquitination of XRCC5 to inhibit AKT signal pathway in PTC.

Postoperative thyroid remnants for differentiated thyroid cancer may not affect the outcome of high-dose radioiodine therapy

OBJECTIVES

This study aims to provide a way to estimate the volume of the thyroid remnant and determine its relationship with the outcome of radioiodine (RAI) therapy in depth.

MATERIALS AND METHODS

A retrospective analysis was performed on patients who underwent initial RAI therapy between January 2010 and January 2016. The patients were divided into five groups based on the thyroid remnant estimated by post-therapy whole-body scan(post-Rx WBS), thyroid scintigraphy and ultrasonography. The relationship between the volume of thyroid remnant and the outcome of RAI therapy were evaluated by univariate analysis and multivariate analysis.

RESULTS

Of 703 patients, the majority could be found different size of thyroid remnants using the three imaging methods, and only few patients(2.1%) could reach no thyroid remnant. There was no association between the volume of thyroid remnant and the outcome of RAI therapy in univariate analysis (χ₂ = 1.633, P = 0.652) and multivariate analysis (P > 0.05). In the subgroup of patients with high-risk factors, there was still no significant difference (intermediate risk subgroup: P = 0.338 vs high risk subgroup: P = 0.263).

CONCLUSION

Different sizes of thyroid remnants were left after surgery. However, in high radioiodine activity, the volume of thyroid remnants may not affect the outcome of RAI therapy even in patients with some high-risk factors, so the high radioiodine activities may resolve the the problem caused by thyroid remnants in some cases.

Low-dose radioiodine therapy for patients with intermediate- to high-risk differentiated thyroid cancer

OBJECTIVE

The efficacy of low-dose radioiodine therapy (RIT) for intermediate-risk or high-risk differentiated thyroid cancer (DTC) patients is controversial. Because of the country's shortage of medical facilities for RIT, 1110-MBq RIT for higher risk DTC patients has been performed on an outpatient basis since 2010 in Japan. Herein, we addressed this issue and attempted to determine prognostic factors for the prediction of RIT outcomes.

METHODS

We retrospectively analyzed the cases of 119 patients with papillary thyroid cancer who underwent their first RIT with 1110 MBq radioactive iodine (RAI) following a total thyroidectomy, including 65 (54.6%) intermediate-risk and 54 (45.4%) high-risk patients (according to Japan's 2018 clinical practical guidelines for thyroid tumors). Successful ablation was defined when a negative I-131 whole-body scan and thyroglobulin (Tg) < 2 ng/mL were obtained at a diagnostic scan performed 148-560 days (median 261 days) after the first RIT.

RESULTS

The overall ablation success rate was 23.4%. Although the ablation success rates of each pretreatment protocol [recombinant human thyroid stimulating hormone and thyroid hormone withdrawal (THW)] did not differ significantly, THW tended to result in a higher success rate than rhTSH. The Tg level at RIT was the only independent powerful predictive factor for successful ablation. The best cut-off value of Tg for predicting unsuccessful ablation was 9 ng/mL.

CONCLUSIONS

The ablation success rate was much lower than those of earlier studies; the most plausible reason would be that higher risk DTC patients were included in this study. The low-dose RIT routinely performed in Japan might be inadequate for the achievement of successful ablation. At least for patients with Tg > 9 ng/mL at the first RIT, a higher dose of RAI is recommended.