Prediction of pathologic complete response on MRI in patients with breast cancer receiving neoadjuvant chemotherapy according to molecular subtypes.

OBJECTIVES: This study aimed to investigate the predictability of breast MRI for pathologic complete response (pCR) by molecular subtype in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) and investigate the MRI findings that can mimic residual malignancy. METHODS: A total of 506 patients with breast cancer who underwent MRI after NAC and underwent surgery between January and December 2018 were included. Two breast radiologists dichotomized the post-NAC MRI findings as radiologic complete response (rCR) and no-rCR. The diagnostic performance of MRI predicting pCR was evaluated. pCR was determined based on the final pathology reports. Tumors were divided according to hormone receptor (HR) and human epidermal growth factor receptor (HER) 2. Residual lesions on post-NAC MRI were divided into overt and subtle which classified as nodularity or delayed enhancement. Pearson's χ2 and Wilcoxon rank-sum tests were used for MRI findings causing false-negative pCR. RESULTS: The overall pCR rate was 30.04%. The overall accuracy for predicting pCR using MRI was 76.68%. The accuracy was significantly different by subtypes (p < 0.001), as follows in descending order: HR - /HER2 - (85.63%), HR + /HER2 - (82.84%), HR + /HER2 + (69.37%), and HR - /HER2 + (62.38%). MRI in the HR - /HER2 + type showed the highest false-negative rate (18.81%) for predicting pCR. The subtle residual enhancement observed only in the delayed phase was associated with false-negative findings (76.2%, p = 0.016). CONCLUSIONS: The diagnostic accuracy of MRI for predicting pCR differed by molecular subtypes. When the residual enhancement on MRI after NAC is subtle and seen only in the delayed phase, overinterpretation of residual tumors should be performed with caution. KEY POINTS: • In patients with breast cancer after completion of neoadjuvant chemotherapy, the diagnostic accuracy of MRI for predicting pathologic complete response (pCR) differed according to molecular subtype. • When residual enhancement on MRI is subtle and seen only in the delayed phase, this finding could be associated with false-negative pCR results.

Approach to Bethesda system category III thyroid nodules according to US-risk stratification.

This study evaluated how to manage Bethesda category III (Bethesda III) (atypia of undetermined significance/follicular lesion of undetermined significance [AUS/FLUS]) thyroid nodules according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) to reduce unnecessary surgeries. A total of 161 thyroid nodules diagnosed as Bethesda III underwent surgery from 2016 to 2019. Ultrasonography-guided fine-needle aspiration (US-FNA) or core needle biopsy (CNB) was used for repeat examination. K-TIRADS category was assigned to the thyroid nodules. The proportion of malignancy in Bethesda III nodules confirmed by surgery were significantly increased in proportion relative to K-TIRADS with 60.0% low suspicion, 88.2% intermediate suspicion, and 100% high suspicion nodules (p < 0.001). The proportion of malignancy in AUS and FLUS were significantly different (94.2% vs. 40.0% p = 0.003). The proportion of malignancy in AUS increased with K-TIRADS categories, but there was no difference in FLUS. All K-TIRADS high suspicion nodules were AUS as papillary carcinomas (99%), while 80% of FLUS nodules and 50% of follicular carcinomas showed K-TIRADS low suspicion. In 116 nodules with repeat FNA or CNB after initial Bethesda III results, the conclusive result rate was significantly increased in proportion to K-TIRADS with 58.3% low suspicion, 83.3% intermediate suspicion, and 88.8% high suspicion nodules (p = 0.015). K-TIRADS low suspicion nodules of Bethesda III nodules should be managed after risk-benefit consideration rather than immediate surgery or repeat examination. K-TIRADS for Bethesda III nodules can predict papillary carcinoma well, but not follicular carcinoma.

Breast Cancer Screening with Abbreviated Breast MRI: 3-year Outcome Analysis.

Background Data are limited regarding the performance of abbreviated screening breast MRI during consecutive years and the characteristics of breast cancers missed and detected with it. Purpose To assess the longitudinal diagnostic performance of abbreviated screening MRI and to determine whether the screening outcomes of abbreviated MRI differed between yearly time periods for 3 consecutive years. Materials and Methods This retrospective study included 1975 consecutive women who underwent abbreviated screening MRI between September 2015 and August 2018. Breast Imaging Reporting and Data System (BI-RADS) categories 3-5 defined positive results, and BI-RADS categories 1-2 defined negative results. Cancer detection rate (CDR), sensitivity, specificity, positive predictive value (PPV), abnormal interpretation rate (AIR), and interval cancer rate were assessed annually. Yearly performance measures were compared with the Fisher exact test by using the permutation method. Clinical-pathologic and imaging characteristics of the missed and detected cancers were compared by using the Fisher exact test and the Wilcoxon rank sum test. Results A total of 1975 women (median age, 49 years; interquartile range, 44-56 years) underwent 3037 abbreviated MRI examinations over 3 years. CDR (year 1 to year 3, 6.9-10.7 per 1000 examinations), positive predictive value for recall (9.7% [six of 62] to 15.6% [12 of 77]), positive predictive value for biopsy (31.6% [six of 19] to 63.2% [12 of 19]), sensitivity (75.0% [six of eight] to 80.0% [12 of 15]), and specificity (93.5% [807 of 863] to 94.1% [1041 of 1106]) were highest in year 3, and AIR (7.1% [62 of 871] to 6.9% [77 of 1121]) was lowest in year 3. However, all outcome measures did not differ statistically between years 1, 2, and 3 (all P > .05). The interval cancer rate was 0.66 per 1000 examinations (two of 3037). Thirty-eight breast cancers were identified in 36 women; 29 were detected with abbreviated MRI, but nine were missed. Of these, seven were detected with other imaging modalities after negative results at the last screening MRI examination, and two were interval cancers. All missed cancers were node-negative early-stage invasive cancers and were smaller (median size, 0.8 cm vs 1.2 cm; P = .01) than detected cancers. Conclusion Screening outcome measures of abbreviated MRI were sustained without significant differences between 3 consecutive years. All cancers missed at abbreviated MRI were node-negative invasive cancers and tended to be smaller than detected cancers. © RSNA, 2021 See also the editorial by Lee in this issue. Online supplemental material is available for this article.

Non-mass lesions detected by breast US: stratification of cancer risk for clinical management.

OBJECTIVE: To develop a classification system using imaging features to interpret breast non-mass lesions (NMLs) detected on US and to stratify their cancer risk. METHODS: This retrospective study included 715 patients with 715 breast NMLs detected on breast US from 2012 to 2016. Each patient underwent mammography at the time of diagnosis. Radiologists assessed US and mammographic features and final BI-RADS categories. Multivariable logistic regression was used to find imaging features associated with malignancy in a development dataset (n = 460). A system to classify BI-RADS categories (3 to 5) was developed based on the odds ratios (ORs) of imaging features significantly associated with malignancy and validated in a distinct validation dataset (n = 255). RESULTS: Among 715 NMLs, 385 (53.8%) were benign and 330 (46.2%) were malignant. In the development dataset, the following B-mode US features were associated with malignancy (all p < 0.001): segmental distribution (OR = 3.03; 95% confidence interval [CI], 1.50-6.15), associated calcifications (OR = 4.26; 95% CI, 1.62-11.18), abnormal ductal change (OR = 4.91; 95% CI, 2.07-11.68), and posterior shadowing (OR = 20.20; 95% CI, 6.46-63.23). The following mammographic features were also associated with malignancy (all p < 0.001): calcifications (OR = 7.98; 95% CI, 3.06-20.81) and focal asymmetry (OR = 4.75; 95% CI, 1.90-11.88). In the validation dataset, our classification system using US and mammography showed a higher area under the curve (0.951-0.956) compared to when it was not applied (0.908-0911) to predict malignancy with BI-RADS categories (p < 0.05). CONCLUSION: Our classification system which incorporates US and mammographic features of breast NMLs can help interpret and manage all NMLs detected on breast US by stratifying cancer risk according to BI-RADS categories. KEY POINTS: • When diagnosing breast NMLs detected on US, suspicious US features are segmental distribution, associated abnormal ductal change, calcifications, and posterior shadowing within or around the NML on B-mode US, while a probably benign US feature is the presence of multiple small cysts. • Corresponding suspicious mammographic features of breast NMLs detected on US are associated calcifications and focal asymmetry. • Our classification system which incorporates US features with and without mammography can potentially be used to interpret and manage any NMLs detected on breast US in clinical practice.

Ultrasonographic characteristics of medullary thyroid carcinoma according to nodule size: application of the Korean Thyroid Imaging Reporting and Data System and American Thyroid Association guidelines.

BACKGROUND: Few studies have categorized ultrasound (US) findings of various sized medullary thyroid carcinomas (MTCs) according to updated guidelines. PURPOSE: To evaluate and compare the differences in US findings of MTC according to nodule size, using the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and American Thyroid Association (ATA) guidelines. MATERIAL AND METHODS: The study included 119 patients with 129 MTC nodules, which were surgically confirmed at our institution between March 1999 and September 2017. Nodules were divided into large (≥1.0 cm) and small (<1.0 cm) groups. US images were analyzed according to the K-TIRADS and ATA guidelines. The differences in US characteristics between small and large nodules were compared using Fisher's exact or Chi-square tests. RESULTS: Of 129 MTC nodules, 84 (65.1%) were large nodules and 45 (34.9%) were small nodules. According to the nodule size, small MTC nodules were classified more commonly as high suspicion by K-TIRADS and ATA (95.6% and 93.3%, respectively) (P < 0.001), but presented neither cystic change, isoechogenicity, nor low suspicion category by K-TIRADS and ATA. In contrast, large MTC nodules showed more frequently cystic change (15.5%), isoechogenicity (16.7%), smooth margins (50%), or low or intermediate suspicion US features by K-TIRADS and ATA (59.6% and 36.0%, respectively) (all P values < 0.001). CONCLUSION: Most small MTC nodules are classified as high suspicion on US, whereas large MTC nodules are diagnosed more frequently as low or intermediate suspicion by K-TIRADS and ATA.

Ultrasound-guided fine-needle aspiration or core needle biopsy for diagnosing follicular thyroid carcinoma?

OBJECTIVE: We evaluated the preoperative diagnostic values of ultrasound (US), fine-needle aspiration (FNA) and core needle biopsy (CNB) leading to surgery in patients with FTC. METHODS: From October 1994 to July 2016, 298 patients with FTC who had preoperative US images and underwent US-guided FNA or CNB and surgery were included in this study. We evaluated the results of preoperative FNA or CNB based on the Bethesda system and the US findings according to the Korean thyroid imaging reporting and data system (K-TIRADS). RESULTS: Predominant US features of FTC showed solid, hypo- or iso-echogenicity, oval smooth margin and halo with no calcification. Based on K-TIRADS, 140 (47.0%) patients with FTC were categorized as low suspicion, 133 (44.63%) as intermediate suspicion and 25 (8.4%) as high suspicion at US. Considering only FNA cytology (n = 230), 6.9% were revealed as Bethesda class I, 16.1% as class II, 37.0% as class III, 29.1% as class IV and 10.9% as class V. Considering the 68 cases with CNB results, 2.9% were revealed as class I, 4.4% as class II, 20.6% as class III and 72.1% as class IV. Despite multiple FNAs, 16.7% of the 84 patients with FTC still obtained Bethesda class I or class II. CNB results in patients with FTC had a significantly higher rate of Bethesda class IV compared to the FNA results (P < .001). FTCs with distant metastasis exhibited a significantly higher rate of Bethesda classes IV and V compared to those without distant metastasis (P = .004). CONCLUSION: Surgery for FTC is deferred only with preoperative US and FNA. CNB in patients with FTC can lead to surgery better than FNA. Therefore, if the US feature is characteristic and a serially growing large nodule is suspected, the first attempt of CNB may be helpful in selecting a surgical candidate.

Long-term Surveillance of Ductal Carcinoma in Situ Detected with Screening Mammography versus US: Factors Associated with Second Breast Cancer.

Background The relationship between method of breast cancer screening (mammography or US) and survival outcome in patients with screening-detected ductal carcinoma in situ (DCIS) has not been determined. Purpose To investigate whether different methods of breast cancer screening are associated with different survival outcomes in patients with screening-detected DCIS and to evaluate clinical-pathologic and imaging factors associated with second breast cancer. Materials and Methods We retrospectively identified women who underwent surgery to treat DCIS initially detected with screening mammography or US between July 2004 and December 2011 in a single institution. Overall survival (OS) and disease-free survival (DFS) were assessed. Factors associated with second breast cancer (invasive carcinoma or DCIS) were found with multivariable Cox proportional hazards regression analysis. Subgroups were analyzed according to screening method. Results A total of 814 women (median age, 47 years; age range, 25-81 years) were included; 627 underwent treatment for screening mammography-detected DCIS (mammography-detected group), and 187 underwent treatment for screening US-detected DCIS (US-detected group). During follow-up (median, 7 years; interquartile range, 5-8 years), 26 ipsilateral and 26 contralateral second breast cancers (6.4%, 52 of 814) were found, with 44 in the mammography-detected group and eight in the US-detected group. The overall 5-year OS and DFS rates were 100% and 95.3%, respectively. DFS rates did not differ according to screening method (P = .21, 5-year DFS rates were 94.9% in the mammography-detected group and 96.5% in the US-detected group). In the mammography-detected group, higher nuclear grade (intermediate grade: hazard ratio [HR], 5.7; 95% confidence interval [CI]: 1.3, 24.3; P = 0.02) (high grade: HR, 8.0; 95% CI: 1.9, 34.2; P = .01) and dense breast (HR, 3.5; 95% CI: 1.1, 11.4; P = 0.04) were associated with second breast cancer. In the US-detected group, human epidermal growth factor receptor 2 positivity was associated with second breast cancer (HR, 9.2; 95% CI: 2.2, 38.5; P = .002). Conclusion Disease-free survival of patients who underwent treatment for screening-detected ductal carcinoma in situ (DCIS) did not differ according to screening detection method. In patients with screening mammography-detected DCIS, higher nuclear grade and dense breast were associated with second breast cancer, and in patients with screening US-detected DCIS, human epidermal growth factor 2 positivity was associated with second breast cancer. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Fowler in this issue.

Comparison of synthetic and digital mammography with digital breast tomosynthesis or alone for the detection and classification of microcalcifications.

OBJECTIVE: To compare the performance of synthetic mammography (SM) and digital mammography (DM) with digital breast tomosynthesis (DBT) or alone for the evaluation of microcalcifications. METHODS: This retrospective study includes 198 mammography cases, all with DM, SM, and DBT images, from January to October 2013. Three radiologists interpreted images and recorded the presence of microcalcifications and their conspicuity scores and final BI-RADS categories (1, 2, 3, 4a, 4b, 4c, 5). Readers' area under the ROC curves (AUCs) were analyzed for SM plus DBT vs. DM plus DBT and SM alone vs. DM alone using the BI-RADS categories for the overall group and dense breast subgroup. RESULTS: Conspicuity scores of detected microcalcifications were neither significantly different between SM and DM with DBT nor alone (p>0.05). In predicting malignancy of detected microcalcifications, no significant difference was found between readers' AUCs for SM and DM with DBT or alone in the overall group or dense breast subgroup (p>0.05). CONCLUSIONS: Diagnostic performances of SM and DM for the evaluation of microcalcifications are not significantly different, whether performed with DBT or alone. KEY POINTS: • In DBT-imaging, SM and DM show comparable performances when evaluating microcalcifications. • For BI-RADS classification of microcalcifications, SM and DM show similar AUCs. • DBT with SM may be sufficient for diagnosing microcalcifications, without DM.

The combination of FDG PET and dynamic contrast-enhanced MRI improves the prediction of disease-free survival in patients with advanced breast cancer after the first cycle of neoadjuvant chemotherapy.

PURPOSE: The aim of this study was to investigate the potential of FDG PET/CT and MRI in predicting disease-free survival (DFS) after neoadjuvant chemotherapy (NAC) and surgery in patients with advanced breast cancer. METHODS: The analysis included 54 women with advanced breast cancer. All patients received three cycles of NAC, underwent curative surgery, and then received three cycles of additional chemotherapy. Before and after the first cycle of NAC, all patients underwent sequential PET/CT and MRI. All patients were analysed using a diverse range of parameters. including maximal standardized uptake value (SUV), percent change in SUV (ΔSUV), initial slope of the enhancement curve (MRslope), apparent diffusion coefficient (ADC), tumour size, change in MRslope (ΔMRslope), change in ADC (ΔADC), change in tumour size (Δsize) and other clinicopathological parameters]. The relationships between covariates and DFS after surgery were analysed using the Kaplan-Meier method and the multivariate Cox proportional hazards model. Time-dependent receiver operating characteristic curves were used to determine the optimal cut-off values of imaging parameters for DFS. RESULTS: Of the 54 patients, 13 (24 %) experienced recurrence at a median follow-up of 38 months (range 25 - 45 months). Univariate and multivariate analyses showed that a lesser decline in SUV, a lesser decline in MRslope, a lesser increase in ADC, and ER negativity were significantly associated with a poorer DFS (P = 0.0006, ΔSUV threshold -41 %; P = 0.0016, ΔMRslope threshold -6 %; P = 0.011, ΔADC threshold 11 %; and P = 0.0086, ER status, respectively). Patients with a combination of ΔSUV >-41 % and ΔMRslope >-6 % showed a significantly higher recurrence rate (77.8 %) than the remaining of patients (13.3 %, P < 0.0001). CONCLUSION: Functional parameters of both FDG PET and MRI after the first cycle of NAC are useful for predicting DFS in patients with advanced breast cancer. This approach could lead to an improvement in patient care because ineffective NAC agents could be avoided and more aggressive therapy could be used in high-risk patients.

What is the difference between the tall cell variant and the classic type of papillary thyroid carcinoma on ultrasonography?

PURPOSE: The prevalence of the tall cell variant of papillary thyroid carcinoma (TCVPTC), which has a poor prognosis, has increased as its definition has been modified. We sought to investigate whether TCVPTC is different from the classic type on ultrasonography (US). METHODS: This study included 46 consecutive TCVPTC patients and 92 classic papillary thyroid carcinoma (PTC) patients who were confirmed surgically at the authors' institution. The US findings and pathologic reports of these patients were retrospectively reviewed. US features based on the Korean Thyroid Imaging Reporting and Data System, preoperative US suspicion for lymph node metastasis, and the presence of capsular location were evaluated. RESULTS: Univariable and multivariable analyses identified that TCVPTC showed more frequent irregular tumor margin (odds ratio [OR], 6.62; 95% confidence interval [CI], 1.46 to 30.09; P=0.014) and capsular location (OR, 4.63; 95% CI, 1.49 to 14.41; P=0.008) than classic PTC. Capsular location was an independent predictor of TCVPTC for tumors less than or equal to 1.5 cm in size (OR, 4.23; 95% CI, 1.12 to 15.92; P=0.033). Irregular margin was an independent predictor of TCVPTC for tumors larger than 1.5 cm (OR, 10.46; 95% CI, 1.16 to 94.48; P=0.037). Extrathyroidal extension was not significantly different between the two groups. CONCLUSION: The two key features of TCVPTC on US are frequent capsular location for tumors less than or equal to 1.5 cm in size and the higher likelihood of an irregular margin for tumors larger than 1.5 cm.

Comparison of the background echotexture between automated breast ultrasound and handheld breast ultrasound.

This study aimed to compare the background echotexture (BE) between automated breast ultrasound (ABUS) and handheld breast ultrasound (HHUS) and evaluate the correlation of BE with mammographic (MG) density and background parenchymal enhancement (BPE) on magnetic resonance imaging (MRI). A total of 212 women with newly diagnosed breast cancer who had undergone preoperative ABUS, HHUS, MG, and MRI were included. Two breast radiologists blinded to the menopausal status analyzed the BE of the contralateral breasts of the patients with breast cancer in consensus. The MG density and BPE of breast MRI on the radiologic reports were compared with the BE in the ultrasound. We used the cumulative link mixed model to compare the BE and Spearman rank correlation to evaluate the association between BE with MG density and BPE. BE was more heterogeneous in ABUS than in HHUS (P < .001) and in the premenopausal group than in the postmenopausal group (P < .001). The heterogeneity of BE in the premenopausal group was higher with ABUS than with HHUS (P = .013). BE and MG density showed a moderate correlation in the postmenopausal group, but a weak correlation in the premenopausal group. BE and BPE showed moderate correlations only in the premenopausal group. ABUS showed a more heterogeneous BE, especially in the premenopausal group. Therefore, more attention is required to interpret ABUS screening in premenopausal women.

Atypical Ductal Hyperplasia: Risk Factors for Predicting Pathologic Upgrade on Excisional Biopsy.

Purpose: To determine the incidence of atypical ductal hyperplasia (ADH) in needle biopsy and the upgrade rate to carcinoma, and to evaluate difference in findings between the upgrade and non-upgrade groups. Materials and Methods: Among 9660 needle biopsies performed over 48 months, we reviewed the radiologic and histopathologic findings of ADH and compared the differences in imaging findings (mammography and breast US) and biopsy methods between the upgrade and non-upgrade groups. Results: The incidence of ADH was 1.7% (169/9660). Of 112 resected cases and 30 cases followed-up for over 2 years, 35 were upgraded to carcinoma (24.6%, 35/142). The upgrade rates were significantly different according to biopsy methods: US-guided core needle biopsy (US-CNB) (40.7%, 22/54) vs. stereotactic-vacuum-assisted biopsy (S-VAB) (16.0%, 12/75) vs. US-guided VAB (US-VAB) (7.7%, 1/13) (p = 0.002). Multivariable analysis showed that only US-CNB (odds ratio = 5.19, 95% confidence interval: 2.16-13.95, p < 0.001) was an independent predictor for pathologic upgrade. There was no upgrade when a sonographic mass was biopsied by US-VAB (n = 7). Conclusion: The incidence of ADH was relatively low (1.7%) and the upgrade rate was 24.6%. Surgical excision should be considered because of the considerable upgrade rate, except in the case of US-VAB.

Reproducibility of Automated Breast Ultrasonography and Handheld Ultrasonography for Breast Lesion Size Measurement.

ABSTRACT: The purpose of our study was to evaluate the reproducibility of size measurement of breast lesions using automated breast ultrasonography (ABUS) compared with that with handheld ultrasonography (HHUS). Three breast radiologists performed HHUS and measured the lesions size in 2 different phantoms: lesions with various shape, size, and same stiffness (phantom 1) and lesions with same shape, size, and various stiffness (phantom 2). After 1 month, the same radiologists measured the lesion size of the same breast phantoms in the images obtained using ABUS. We evaluated interobserver variability between 3 radiologists in ABUS and HHUS, and intraobserver variability of radiologists between ABUS and HHUS. Intraclass correlation coefficient (ICC) was used in statistical analysis. The measured size of lesions on HHUS was slightly larger than that on ABUS in both phantom 1 and 2, although not statistically significant (P = 0.314, P = 0.858). There were no significant differences in size measurements between the radiologists' measurements and the reference size in phantom 2 (P = 0.862). The ICCs for the interobserver agreement between the 3 radiologists were 0.98 to 0.99 on ABUS and 0.99 to 1.00 on HHUS, respectively. The ICCs for the intraobserver agreement between ABUS and HHUS were 0.97 to 0.97 in phantom 1 and 0.98 to 0.99 in phantom 2. In conclusion, ABUS showed excellent interobserver and intraobserver agreement with HHUS in measuring size of the lesions, regardless of shape, size, and stiffness. Therefore, ABUS mixed with HHUS can be used reliably in following up breast lesions size.

Ductal carcinoma in situ: a risk prediction model for the underestimation of invasive breast cancer.

Patients with a biopsy diagnosis of ductal carcinoma in situ (DCIS) may be diagnosed with invasive breast cancer after excision. We evaluated the preoperative clinical and imaging predictors of DCIS that were associated with an upgrade to invasive carcinoma on final pathology and also compared the diagnostic performance of various statistical models. We reviewed the medical records; including mammography, ultrasound (US), and magnetic resonance imaging (MRI) findings; of 644 patients who were preoperatively diagnosed with DCIS and who underwent surgery between January 2012 and September 2018. Logistic regression and three machine learning methods were applied to predict DCIS underestimation. Among 644 DCIS biopsies, 161 (25%) underestimated invasive breast cancers. In multivariable analysis, suspicious axillary lymph nodes (LNs) on US (odds ratio [OR], 12.16; 95% confidence interval [CI], 4.94-29.95; P < 0.001) and high nuclear grade (OR, 1.90; 95% CI, 1.24-2.91; P = 0.003) were associated with underestimation. Cases with biopsy performed using vacuum-assisted biopsy (VAB) (OR, 0.42; 95% CI, 0.27-0.65; P < 0.001) and lesion size <2 cm on mammography (OR, 0.45; 95% CI, 0.22-0.90; P = 0.021) and MRI (OR, 0.29; 95% CI, 0.09-0.94; P = 0.037) were less likely to be upgraded. No significant differences in performance were observed between logistic regression and machine learning models. Our results suggest that biopsy device, high nuclear grade, presence of suspicious axillary LN on US, and lesion size on mammography or MRI were independent predictors of DCIS underestimation.

Impact of Skeletal Muscle Loss and Visceral Obesity Measured Using Serial CT on the Prognosis of Operable Breast Cancers in Asian Patients.

OBJECTIVE: This study aimed to investigate the impact of baseline values and temporal changes in body composition parameters, including skeletal muscle index (SMI) and visceral adipose tissue area (VAT), measured using serial computed tomography (CT) imaging on the prognosis of operable breast cancers in Asian patients. MATERIALS AND METHODS: This study retrospectively included 627 Asian female (mean age ± standard deviation [SD], 53.6 ± 8.3 years) who underwent surgery for stage I-III breast cancer between January 2011 and September 2012. Body composition parameters, including SMI and VAT, were semi-automatically calculated on baseline abdominal CT at the time of diagnosis and follow-up CT for post-treatment surveillance. Serial changes in SMI and VAT were calculated as the delta values. Multivariable Cox regression analysis was used to evaluate the association of baseline and delta SMI and VAT values with disease-free survival. RESULTS: Among 627 patients, 56 patients (9.2%) had breast cancer recurrence after a median of 40.5 months. The mean value ± SD of the baseline SMI and baseline VAT were 43.7 ± 5.8 cm²/m² and 72.0 ± 46.0 cm², respectively. The mean value of the delta SMI was -0.9 cm²/m² and the delta VAT was 0.5 cm². The baseline SMI and VAT were not significantly associated with disease-free survival (adjusted hazard ratio [HR], 0.983; 95% confidence interval [CI], 0.937-1.031; p = 0.475 and adjusted HR, 1.001; 95% CI, 0.995-1.006; p = 0.751, respectively). The delta SMI and VAT were also not significantly associated with disease-free survival (adjusted HR, 0.894; 95% CI, 0.766-1.043; p = 0.155 and adjusted HR, 1.001; 95% CI, 0.989-1.014; p = 0.848, respectively). CONCLUSION: Our study revealed that baseline and early temporal changes in SMI and VAT were not independent prognostic factors regarding disease-free survival in Asian patients undergoing surgery for breast cancer.

Inoperable symptomatic recurrent thyroid cancers: preliminary result of radiofrequency ablation.

PURPOSE: To determine the role of radiofrequency ablation (RFA) in patients with inoperable symptomatic recurrent thyroid cancers. MATERIALS AND METHODS: Eleven patients with 16 symptomatic recurrent thyroid cancers but ineligible for surgery were prospectively enrolled and underwent ultrasound-guided RFA with local anesthesia in 16 sessions. The mean tumor volume and diameter were 9 ml (range 0.1-34 ml) and 2.9 cm (range 0.7-4.8 cm), respectively. Patients had dysphagia, hoarseness, dyspnea, or a protruding mass due to recurrent tumors. Tumor volume was calculated from follow-up ultrasound, and symptoms were assessed after RFA. RESULTS: Of 16 sessions, tumor ablation was complete in 6, incomplete in 9, and failed in 1. Incomplete or failed ablation was due to intolerable pain, severe calcified lesion, or tumor encasement of major vessels. Of 15 treated lesions, 13 decreased in volume. Regrowth of treated tumors was observed in 2 lesions. The mean volume reduction was 50.9% (range -9.4 to 96.8%). There were gains for symptom relief for 7 patients (63.6%) with protruding masses (n = 6) and discomfort due to tracheal compression (n = 1). The mean follow-up was 6 months (1-14 months). There were no major complications except a patient with skin burn. CONCLUSION: RFA is feasible and safe, and can improve symptoms in the short term.

Magnetic Resonance Imaging-Guided Breast Biopsy in Korea: A 10-Year Follow-Up Experience.

PURPOSE: To evaluate the accuracy of magnetic resonance imaging (MRI)-guided breast biopsy. METHODS: We retrospectively reviewed the clinical data of 111 consecutive patients referred for MRI-guided breast biopsy after mammography and breast ultrasound between May 2009 and April 2019. After excluding 37 patients without follow-up images (> 2 years), 74 patients (74 lesions) were finally included. We reviewed the histologic results of MRI-guided biopsy and subsequent surgery, post-biopsy management, and breast cancer development during follow-up. We investigated the false-negative rate, ductal carcinoma in situ (DCIS) underestimation, atypical ductal hyperplasia (ADH) underestimation rate, and technical failure rate of MRI-guided biopsy. RESULTS: Among 74 scheduled MRI-guided biopsies, six were canceled because biopsy was deemed unnecessary, while three failed due to technical difficulties (technical failure rate: 3/68, 4.4%). MRI-guided biopsy was performed in 65 patients, of which 18 patients were diagnosed with malignant lesions, 46 with benign lesions, and one with ADH bordering on DCIS. Subsequent surgery (n = 27) showed DCIS underestimation in three cases (3/7, 43%), ADH underestimation in two cases (1/2, 50%), as well as seven concordant benign and 11 concordant malignant lesions. The overall false-negative rate was 4.3% (2/46). Thirty-eight out of 48 benign lesions were followed-up (median period, 5.8 years; interquartile range, 4.1 years) without subsequent surgery. Thirty-seven concordant benign lesions were stable (n = 27) or disappeared (n = 10); however, the size of one discordant benign lesion increased on follow-up MRI and it was diagnosed as DCIS after 1 year. CONCLUSION: MRI-guided biopsy is an accurate method for exclusion of malignancy with a very low false-negative rate.

Effect of Calcifications on Shear-Wave Elastography in Evaluating Breast Lesions.

This study aimed to investigate the effect of calcifications on shear-wave elastography in evaluating breast lesions. We retrospectively reviewed ultrasound images of 673 breast lesions and compared the elasticity between lesions with and without calcifications in three subgroups: benign lesions, in situ carcinomas and invasive carcinomas. Breast lesions were confirmed histologically (n = 401) or by follow-up images for more than 2 y (n = 272). Calcifications were present in 25.3% (170/673) of the lesions. The Emean values with and without calcifications, respectively, were as follows: 62.8 and 29.8 kPa in benign lesions (p = 0.000), 114.6 and 52.8 kPa in in situ carcinomas (p = 0.037) and 171.9 and 146.4 kPa in invasive carcinomas (p = 0.018). The presence of calcifications significantly increased the Emean of breast lesions. Shear-wave elastography should be carefully interpreted in benign lesions with calcifications and in situ carcinomas without calcifications.

Differentiation of nonneoplastic and neoplastic gallbladder polyps 1 cm or bigger with multi-detector row computed tomography.

OBJECTIVE: To evaluate useful computed tomographic features to differentiate nonneoplastic and neoplastic gallbladder polyps 1 cm or bigger. METHODS: Thirty-one patients with 32 nonneoplastic polyps and 67 patients with 73 neoplastic polyps 1 cm or bigger underwent unenhanced and dual-phase (arterial and portal venous phases) multi-detector row computed tomography. Gallbladder polyps were diagnosed by cholecystectomy. Computed tomographic features including size (1.5 cm), surface (smooth or irregular), shape (pedunculated or sessile), accompanying wall thickening, basal indentation, perception on unenhanced images, and enhancement pattern between 2 groups were compared using univariate and multivariate analyses. RESULTS: On univariate analysis, age 55 years or older (P = 0.0019), size bigger than 1.5 cm (P < 0.0001), irregular surface (P = 0.0033), sessile shape (P = 0.0016), accompanying wall thickening (P = 0.0056), basal indentation (P = 0.0236), and perception on unenhanced images (P < 0.0001) were significantly more frequent in neoplastic polyps as compared with nonneoplastic polyps. On multivariate analysis, size bigger than 1.5 cm (P = 0.0260), sessile shape (P = 0.0397), and perception on unenhanced images (P < 0.0001) were statistically significant. CONCLUSIONS: Size bigger than 1.5 cm, sessile shape, and perception on unenhanced images are the main factors that differentiate neoplastic from nonneoplastic gallbladder polyps 1 cm or bigger.

Feasibility of Adjustable Electrodes for Radiofrequency Ablation of Benign Thyroid Nodules.

OBJECTIVE: The purpose of this study was to evaluate a novel radiofrequency ablation (RFA) application utilizing an adjustable electrode for treatment of benign thyroid nodules. MATERIALS AND METHODS: From April 2011 to December 2018, 21 patients underwent RFA treatment on 21 thyroid nodules, utilizing an 18-gauge internally cooled electrode equipped with a size adjustable active tip. The peripheral nodule portions were ablated with the moving-shot technique and a shorter active tip, and the nodule centers were ablated with the fixed technique and a longer active tip. We assessed parameters including characteristics of the treated nodules, use of variablesized active tips, volume reduction rate, therapeutic success rate, and post-procedural complications. The therapeutic success rate was defined as a > 50% volume reduction of the initial nodule volume at the 6- or 12-month follow-up. RESULTS: The treated thyroid nodules were large enough to cause symptoms (mean volume, 29.6 mL). Two types of active tips per session were used for all nodules. The mean volume reduction rate at the last follow-up was 68.3 ± 4.4% and our therapeutic success rate was 90.5%. Both symptoms and cosmetic scores decreased significantly. Minor complications in three patients were recorded during and after the procedure. CONCLUSION: This initial study demonstrated that an adjustable electrode for RFA of benign thyroid nodules effectively and safely resulted in volume reduction.