Background: and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. Methods: Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. Results: Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). Conclusions The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Purpose: The purpose of this study was to compare the clinical characteristics and outcomes of hormone receptor-positive (HR+) human epidermal growth factor 2-negative (HER2–) breast cancer among elderly patients (over 65 years old) and younger patients. Methods: This was a retrospective cohort study of 328 patients who were treated for breast cancer at Pusan National University Yangsan Hospital between January 2009 and December 2014. Tumor characteristics, surgical methods, and survival outcomes were compared between the two age groups (<65 and ≥65 years old). Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were also constructed according to the age groups. Results: Among the 328 patients with HR+ HER2– breast cancer, 184 (56.1%) were <65 years old and 144 (43.9%) were ≥65 years old. Breast cancer stages were similar between the two age groups, but the older patients were treated less often with chemotherapy (81% vs. 66%, P=0.002). During the follow-up period, 17 deaths and 36 cases of recurrence or metastasis were reported. There was no difference in DFS between the two groups (P=0.840); however, the OS of the older age group was significantly lower than that of the younger age group (P=0.015). Conclusion This study suggested that HR+ HER2– breast cancer patients belonging to the two age groups had no significant difference in DFS. However, older age is an independent factor affecting OS rate. Therefore, even if patients are old, but their physical condition is satisfactory, standard and active treatment may be necessary, similar to that given to younger patients.

Purpose: The purpose of this study was to compare the clinical characteristics and outcomes of hormone receptor-positive (HR+) human epidermal growth factor 2-negative (HER2–) breast cancer among elderly patients (over 65 years old) and younger patients. Methods: This was a retrospective cohort study of 328 patients who were treated for breast cancer at Pusan National University Yangsan Hospital between January 2009 and December 2014. Tumor characteristics, surgical methods, and survival outcomes were compared between the two age groups (<65 and ≥65 years old). Kaplan-Meier curves for disease-free survival (DFS) and overall survival (OS) were also constructed according to the age groups. Results: Among the 328 patients with HR+ HER2– breast cancer, 184 (56.1%) were <65 years old and 144 (43.9%) were ≥65 years old. Breast cancer stages were similar between the two age groups, but the older patients were treated less often with chemotherapy (81% vs. 66%, P=0.002). During the follow-up period, 17 deaths and 36 cases of recurrence or metastasis were reported. There was no difference in DFS between the two groups (P=0.840); however, the OS of the older age group was significantly lower than that of the younger age group (P=0.015). Conclusion This study suggested that HR+ HER2– breast cancer patients belonging to the two age groups had no significant difference in DFS. However, older age is an independent factor affecting OS rate. Therefore, even if patients are old, but their physical condition is satisfactory, standard and active treatment may be necessary, similar to that given to younger patients.

Background: and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. Methods: Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. Results: Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). Conclusions The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Purpose: Breast conserving surgery (BCS) is generally not considered for breast cancer because of concerns about the poor prognosis of triple negative breast cancer (TNBC). We assessed the outcomes of BCS and mastectomy for patients with stage II-IIIA TNBC. Methods: The data of 172 breast cancer patients diagnosed with stage II-IIIA TNBC who underwent treatment at Pusan National University Hospital and Pusan National University Yangsan Hospital from 2010 to 2014 were retrospectively analyzed. The patients were divided into the following two groups: patients who underwent BCS (n=101) and those who underwent mastectomy (n=71). The Cox regression model was used to examine the outcomes of both treatments. The median follow-up period was 71 months in the BCS group, and 67 months in the mastectomy group. Results: The median age of the 172 patients was 51 years (range, 22-82 years). In the BCS group, radiation therapy and chemotherapy (p<0.001 and p=0.007, respectively) were performed more frequently. The BCS group had more patients with a high Ki-67 index (p=0.006), while the mastectomy group included more patients with a higher pathologic T (pT) stage (p=0.005). The 5-year loco-regional recurrence-free, disease-free, and overall survival rates of the BCS group versus the mastectomy group were 93.8% versus 95.3%, 89.8% versus 90.7%, and 90.8% versus 86.3%, respectively, but the differences were not statistically significant. Lymphovascular invasion was a risk factor for disease-free survival and advanced stage was an important risk factor for overall survival. Conclusion In stage II-IIIA TNBC, BCS was not inferior to mastectomy in locoregional recurrence rates, disease-free survival rates, or overall survival rates.

Purpose: There are many studies on sentinel lymph node (SLN) biopsy in thyroid carcinoma but SLN biopsy (SLNB) in papillary thyroid carcinoma (PTC) remains open to debate. Therefore in this retrospective study, the usefulness of SLNB in thyroid carcinoma patients who had micro-PTC without cervical lymphadenopathy was assessed. Methods: SLNB was performed in 114 patients who were diagnosed with micro-PTC in a single lobe without palpable or ultrasound-detected lymph node at the tertiary center between January 2012 and December 2013. After SLNB, all patients underwent total thyroidectomy and central neck dissection or thyroid lobectomy and central neck dissection of the single side. Results: SLNs were identified in 112 of 114 patients with 41 positive SLNs and 71 negative SLNs on intraoperative frozen sections. However, eight negative patients were found to be positive in the final pathology. Sentinel node identification rate and false negative value of SLNB were 98.2% and 11.3%, respectively. In the univariate analysis, higher lymph node metastasis was detected in men than in women. Higher detection number of SLN showed higher probability of lymph node metastasis. Conclusion SLNB may be helpful in papillary thyroid cancer, especially in male patients. Also, it is useful for the staging of nodal status and clearance of persistent disease.

OBJECTIVE: To compare the image quality of low-dose (LD) computed tomography (CT) obtained using a deep learning-based denoising algorithm (DLA) with LD CT images reconstructed with a filtered back projection (FBP) and advanced modeled iterative reconstruction (ADMIRE).MATERIALS AND METHODS: One hundred routine-dose (RD) abdominal CT studies reconstructed using FBP were used to train the DLA. Simulated CT images were made at dose levels of 13%, 25%, and 50% of the RD (DLA-1, -2, and -3) and reconstructed using FBP. We trained DLAs using the simulated CT images as input data and the RD CT images as ground truth. To test the DLA, the American College of Radiology CT phantom was used together with 18 patients who underwent abdominal LD CT. LD CT images of the phantom and patients were processed using FBP, ADMIRE, and DLAs (LD-FBP, LD-ADMIRE, and LD-DLA images, respectively). To compare the image quality, we measured the noise power spectrum and modulation transfer function (MTF) of phantom images. For patient data, we measured the mean image noise and performed qualitative image analysis. We evaluated the presence of additional artifacts in the LD-DLA images.RESULTS: LD-DLAs achieved lower noise levels than LD-FBP and LD-ADMIRE for both phantom and patient data (all p < 0.001). LD-DLAs trained with a lower radiation dose showed less image noise. However, the MTFs of the LD-DLAs were lower than those of LD-ADMIRE and LD-FBP (all p < 0.001) and decreased with decreasing training image dose. In the qualitative image analysis, the overall image quality of LD-DLAs was best for DLA-3 (50% simulated radiation dose) and not significantly different from LD-ADMIRE. There were no additional artifacts in LD-DLA images.CONCLUSION: DLAs achieved less noise than FBP and ADMIRE in LD CT images, but did not maintain spatial resolution. The DLA trained with 50% simulated radiation dose showed the best overall image quality.
Artifacts ; Humans ; Noise ; Tomography, X-Ray Computed

Background/Aims: Enzymatic analysis of aspartate/alanine aminotransferase (AST/ALT) does not exactly represent the progression of liver fibrosis or inflammation. Immunoassay for AST (cytoplasmic [c] AST/mitochondrial [m] AST) and ALT (ALT1/ALT2) has been suggested as one alternatives for enzymatic analysis. The objective of this study was to evaluate the efficacy of immunoassay in predicting liver fibrosis and inflammation. Methods: A total of 219 patients with chronic hepatitis B (CHB) who underwent hepatic venous pressure gradient (HVPG) and liver biopsy before antiviral therapy were recruited. Serum samples were prepared from blood during HVPG. Results of biochemical parameters including enzymatic AST/ALT and immunological assays of cAST, mAST, ALT1, and ALT2 through sandwich enzyme-linked immunosorbent assay (ELISA) immunoassay with fluorescence labeled monoclonal antibodies were compared with the results of METAVIR stage of live fibrosis and the Knodell grade of inflammation. Results: METAVIR fibrosis stages were as follows: F0, six (3%); F1, 52 (24%); F2, 88 (40%); F3, 45 (20%); and F4, 28 patients (13%). Mean levels of AST and ALT were 121 ± 157 and 210 ± 279 IU/L, respectively. Mean HVPG score of all patients was 4.7 ± 2.5 mmHg. According to the stage of liver fibrosis, HVPG score (p < 0.001, r = 0.439) and ALT1 level (p < 0.001, r = 0.283) were significantly increased in all samples from patients with CHB. ALT (p < 0.001, r = 0.310), ALT1 (p < 0.001, r = 0.369), and AST (p < 0.001, r = 0.374) levels were positively correlated with Knodell grade of inflammation. Conclusions ALT1 measurement by utilizing sandwich ELISA immunoassay can be useful method for predicting inf lammation grade and fibrosis stage in patients with CHB.

Differentiated thyroid cancer (DTC) originating from thyroid tissue is affected by thyrotropin (TSH). TSH suppression therapy is usually recommended after thyroidectomy in cases of DTC. A 57-year-old woman who harbored a very huge recurred lymph node underwent TSH suppression therapy because of the risk of surgical complications. After TSH suppression, the huge neck lymph node exhibited a response and decreased in size. She had been followed up for 144 months. TSH suppression therapy could be considered as an alternative treatment option in a recurred DTC patient with a high perioperative risk.

Differentiated thyroid cancer (DTC) originating from thyroid tissue is affected by thyrotropin (TSH). TSH suppression therapy is usually recommended after thyroidectomy in cases of DTC. A 57-year-old woman who harbored a very huge recurred lymph node underwent TSH suppression therapy because of the risk of surgical complications. After TSH suppression, the huge neck lymph node exhibited a response and decreased in size. She had been followed up for 144 months. TSH suppression therapy could be considered as an alternative treatment option in a recurred DTC patient with a high perioperative risk.