ABSTRACT
OBJECTIVE: To develop and validate a radiomics-clinical combined model combining preoperative 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 sTg was an independent clinical risk factor affecting the efficacy of initial 131I treatment (P = 0.002), 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.
ABSTRACT
OBJECTIVE: To investigate the relationship of BRAF mutation with the outcome of the first postoperative 131I treatment and malignant biological characteristics in papillary thyroid carcinoma (PTC). METHODS: Thirty-three patients with PTC who underwent their first 131I treatment after total thyroidectomy were enrolled in this study. BRAF mutation in postoperative tumor tissue and circulating tumor DNA (ctDNA) in peripheral blood at the time of 131I treatment were detected. According to the status of BRAF mutation, all patients were divided into 2 groups in each category of tumor tissues and ctDNA, respectively: 1) BRAF mutation, 2) BRAF wild-type. The Fisher's exact test was performed to analyze the relationship of BRAF mutation in either tumor tissue or ctDNA with the outcome of the first 131I treatment and malignant characteristics of PTC. RESULTS: BRAF mutation was detected in tumor tissues in 25 patients (25/33,75.8%), and all the patients had single mutation site. In ctDNA, BRAF mutation was detected in 5 patients (5/33, 15.2%), and all the patients had single mutation site. In both tumor tissues and ctDNA, BRAF mutation showed no relationship with the outcome of first 131I treatment and the malignant biological characteristics (P>0.05). CONCLUSION: The value of BRAF mutation alone might be limited in predicting therapeutic outcome of the first 131I treatment in PTC. No definitive relevance was found between BRAF mutation and malignant biological features in PTC.
ABSTRACT
OBJECTIVE: To investigate the impact factors of the outcome of the first 131I treatment in patients with papillary thyroid carcinoma (PTC) after total thyroidectomy. METHODS: Three hundred and fifty-three patients [256 females, 97 males, average age (43.58 ± 12.33 years)] with PTC after total thyroidectomy who underwent 131I treatment from July 2014 to August 2017 were retrospectively analyzed. Curative efficacy of 131I treatment was assessed 6 months afterward. Therapeutic outcome was determined according to thyrotropin (TSH)-stimulated thyroglobulin (sTg) level, 131I diagnostic whole-body scan (Dx-WBS) after 131I treatment and other imaging modalities. Twelve possible factors affecting the therapeutic outcome of 131I treatment including patients' gender, age, interval between surgery and 131I treatment, primary tumor size and extrathyroidal extension (ETE), number and range of primary tumor lesions, result of 99mTcO4- thyroid scan, number of metastatic lymph nodes (LN), pre-treatment laboratory measurements [TSH, sTg and Tg antibody (TgAb)], therapeutic dose of 131I and result of 131I post-treatment whole-body scan (Rx-WBS) were analyzed using univariate and multivariate logistic regression. The receiver operator characteristic (ROC) curve and diagnostic cutoff value were analyzed to evaluate the predictive value of the significant quantitative impact factors for the outcome of 131I treatment. RESULTS: The curative rate of the first 131I treatment in patients with PTC after total thyroidectomy was 62.32% (220/353). Univariate analysis indicated that gender, age, number and range of primary tumor lesions, number of metastatic LN, pre-treatment sTg and TgAb, therapeutic dose of 131I and result of 131I Rx-WBS (all P < 0.05) were significant factors affecting the outcome of 131I treatment. Multivariate analysis revealed that the numbers of metastatic LN (regression coefficient = 1.170) and sTg (regression coefficient = 0.280) were significant impact factors (all P < 0.001). The regression equation was: Logit P = - 3.997 + 1.170 × number of metastatic LN + 0.280 × sTg (χ2 = 210.68, P < 0.001). Taking sTg as a predictive factor for the outcome of the first 131I treatment, the area under the curve (AUC) of ROC for sTg was 0.917 (95% CI 0.890-0.944). The cutoff value of sTg was 2.69 ng/mL with a sensitivity of 92.48% (123/133) and specificity of 74.09% (163/220). CONCLUSION: Patients with PTC after total thyroidectomy with low pre-treatment sTg level and few lymph node metastases are more likely to be cured by the first 131I treatment.
