Objective:To investigate the effect of 131I therapy on the clinical outcome of patients with differentiated thyroid cancer (DTC) who were evaluated as indeterminate response (IDR) after surgery and before 131I therapy. Methods:A total of 281 DTC patients (89 males, 192 females, age (38.4±10.2)years ) assessed as IDR before 131I therapy and after total or near-total thyroidectomy in the Department of Nuclear Medicine of Peking Union Medical College Hospital from April 2009 to March 2022 were retrospectively analyzed. Patients were divided into 131I therapy group ( 131I group) and just thyroid stimulating hormone (TSH) suppressive therapy group (TSH group) according to whether receiving 131I therapy, and the efficacies of two groups at the end of follow-up were compared. Subgroup analysis was conducted in different risk stratifications (low-risk, moderate-risk and high-risk), positive thyroglobulin antibody (TgAb) group (TgAb≥115 kU/L) and negative TgAb group (TgAb<115 kU/L). For patients with positive TgAb, the duration and rate for TgAb declining to negative level under the 2 regimens were compared. Independent-sample t test, Mann-Whitney U test, χ2 test and Fisher exact test were performed to compare the differences between groups. Results:Median follow-up time was 39(6-146) months. There was no statistical difference between patients in 131I group and TSH group in baseline characteristics, and the efficacies at the end of follow-up was similar between the 2 groups ( χ2=6.50, P=0.075). For low-, moderate- and high-risk stratification, there were also no statistical differences of response to 2 regimens ( P=0.221; χ2=4.21, P=0.223; χ2=3.01, P=0.274). Similar results were showed for patients with positive and negative TgAb ( n=50, n=231; χ2=4.02, P=0.242; χ2=3.14, P=0.341). For patients with positive TgAb, the duration and rate for TgAb declining to negative level were not statistically different either between 2 regimens (71.0%(22/31) vs 14/19, χ2=0.04, P=0.836; 7.0(5.0, 9.3) vs 7.0(5.0, 7.3) months, z=-0.89, P=0.375). Conclusion:For DTC patients assessed as IDR after surgery, 131I therapy may not provide more benefit than follow-up with TSH suppressive therapy.

【Objective】 To evaluate which factors may affect magnetic resonance imaging (MRI) performance in the detection of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC). 【Methods】 This retrospective study involved 89 patients diagnosed with invasive breast carcinoma who received NAC at The Second Affiliated Hospital of Xi’an Jiaotong University from July 2019 to December 2021. Breast MRI was performed before and after NAC. Based on the pathological results obtained surgery after the completion NAC and using Miller-Payne classification as the evaluation standard, the patients were divided into two subgroups: pCR and non-pathological complete response (npCR). Chi-square test was used to compare the MRI characteristics of pre-NAC lesions between the two groups. ROC curve analysis was made to analyze the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of MRI after NAC; the diagnostic performance of MRI in predicting pCR in different tumor subtypes was analyzed. We made univariate and multivariate analyses of factors affecting radiographic complete response (rCR) and pCR concordance. 【Results】 MRI analysis after NAC showed rCR in 20 cases (22.5%) and pCR in 28 cases (31.5%). Considering rCR as a "positive" result of MRI analysis, MRI assessment was accurate in 79 cases, including 19 true positive cases and 60 true negative cases. MRI assessment was inaccurate in 10 cases, including 9 false negative cases and 1 false positive case. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MRI assessment of pCR were 67.86%, 98.36%, 88.76%, 95.00%, and 86.96%. MRI had the lowest diagnostic efficiency in evaluating pCR of ERBB2+ breast cancer after NAC. Single factor analysis showed that estrogen receptor (ER), clinical stage, background parenchymal enhancement, and maximum tumor diameter all affected the consistency of rCR and pCR (P<0.05). Multivariate Logistic regression analysis showed that the independent influencing factor affecting the consistency of rCR and pCR was clinical stage. 【Conclusion】 MRI demonstrated good accuracy in predicting pCR after NAC in the breast cancer patients examined. Pre-treatment MRI characteristics and tumor subtypes may be related to the diagnostic accuracy of post-NAC MRI in breast cancer patients.