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Abstract A 2 mm resection margin is considered adequate for ductal carcinoma in situ (DCIS). We assessed the effectiveness of a tailored radiation dose for margins

Purpose: Positive margins after breast-conserving surgery are associated with poor oncological outcomes and warrant additional surgery. This study aimed to evaluate the effectiveness of high-dose radiation therapy for positive margins by comparing local recurrence between patients with positive and negative margins. Methods: We retrospectively evaluated 550 patients treated with adjuvant radiation therapy after breast-conserving surgery for invasive breast cancer between 2013 and 2019. The total equivalent dose in 2 Gy fractions (EQD2) to the tumor bed ranged from 65.81 to 66.25 Gy for positive margins and 59.31–61.81 Gy for negative margins. The differences in local recurrence between the positive and negative margin groups were analyzed. Results: After a median follow-up of 58 months, the crude local recurrence rate was 7.3% in the positive margin group (n = 55) and 2.4% in the negative margin group (n = 495). Positive margins were associated with higher local recurrence without statistical significance in the entire cohort (p = 0.062). Among patients aged

PurposeThe incidence of early tumor detection is increasing due to popularization of breast cancer screening and the development of imaging techniques. Thus, suitable preoperative localization is required for proper diagnosis and treatment of non-palpable breast lesions. The purpose of this study was to evaluate the efficacy and safety of indocyanine green (ICG)-hyaluronic acid (HA) mixture for lesion localization compared to activated charcoal.MethodsThis was a multicenter, randomized, open-label, parallel phase 3 clinical trial performed at four centers in Korea. Female patients scheduled for surgery to remove non-palpable breast lesions were enrolled. One hundred and nine patients were randomly assigned to a control group (activated charcoal: 0.3. – 1 mL) or a study group (ICG-HA mixture, 0.2 mL) for the localization of a breast lesion. The primary endpoint was the accuracy of resection. Secondary endpoints included the technical success rate, histopathological accuracy, skin pigmentation rate, and adverse event rate.ResultsA total of 104 patients were eligible for per-protocol analysis (control group, n = 51; study group, n = 53). The accuracy of resection in the study group was not inferior to that of the control group (90.57% vs. 98.04%, 95% confidence interval (CI): -2.31 – 18.91, p = 0.21). There was no statistically significant difference in technical success rate between the two groups (marking on breast skin: p = 0.11, marking on the excised specimen: p = 0.12). However, there were statistically significant differences in histopathological accuracy (0.26 ± 0.13 vs. 0.33 ± 0.17, p = 0.01) and skin pigmentation rate (0.00% vs. 30.77%, p< 0.01). Adverse events were not reported in either group.ConclusionsWhen localization was performed using ICG-HA, the accuracy of resection was not inferior to that of activated charcoal. However, skin pigmentation rate was significantly lower. In conclusion, ICG-HA is effective and safe for localizing of non-palpable breast lesions.

Abstract Background Increasing rates of breast cancer screening have been associated with an increasing frequency of non-palpable breast lesions detection. Preoperative breast lesion localization is essential for optimizing excision accuracy. This study aimed to evaluate the efficacy and safety of indocyanine green (ICG) hyaluronic acid injection as a novel mixture for localization. Methods We performed a prospective clinical trial with female patients who underwent surgery for non-palpable breast lesions. All patients were sequentially assigned to the control group (localization with activated charcoal), Test Group 1 (ICG-hyaluronic acid mixture 0.1 mL), or Test Group 2 (ICG-hyaluronic acid mixture 0.2 mL) by 1:1:1 ratio. Results A total of 44 patients were eligible for this study (Control Group = 14, Test Group 1 = 15, Test Group 2 = 15 patients). Fibroadenoma (n = 17, 38.6%) accounted for the largest proportion of diagnoses, and five patients (11.4%) were diagnosed with malignancies. There were no statistically significant differences in baseline characteristics among the three groups. The marking rate was over 86% in all groups, with no significant intergroup differences. Skin pigmentation was only observed in the control group. The mean accuracy of resection (the greatest diameter of the excised specimen divided by the greatest diameter of the preoperative lesion as observed using ultrasonography, with values closer to 1 reflecting a higher accuracy) was 3.7 in the control group, 2.2 in Test Group 1, and 2.1 in Test Group 2 (p = 0.037 between Controls and Test Group 1, p = 0.744 between Test Group 1 and Test Group 2, and p = 0.026 between Controls and Test Group 2). Conclusion ICG-hyaluronic acid injection is a novel method that was shown to accurately localize non-palpable breast lesions and was associated with no skin pigmentation. Further research is required to apply this method to malignant breast lesions. Trial registration “A Multicenter Open-label, Parallel, Phase 2 Clinical Trial to Evaluate the Efficacy and Safety of LuminoMark™ Inj. (Conc. for Fluorescence) Localization in Patients with Non-palpable Breast Lesions” was prospectively registered as a trial (ClinicalTrials. gov Identifier: NCT03743259, date of registration: May 29, 2018, https://clinicaltrials.gov/ct2/show/NCT03743259 )

The purpose of this study was to examine whether or not “Scaffolded Think-Group-Share” learning can have a positive effect on student satisfaction and learning achievement in English classes of an Indonesian elementary school. To achieve this purpose, thisstudy compared the findings from the two dependent variables (i.e., student satisfaction and English learning achievement) in “Scaffolded Think-Group-Share” learning with those in “Group Investigation” and “Learning Together” learning, which are other types of cooperative learning methods. According to the findings, there were statistically significant differences in student satisfaction and English learning achievement between the Scaffolded Think-Group-Share group, the Group Investigation group, and the Learning Together group. This study implies that “Scaffolded Think-Group-Share” learning has the potential to enhance student satisfaction and comprehension in English as a foreign language (EFL) classes.

Korea has used three different teacher evaluation systems since the 1960s: teacher performance rating, teacher performance-based pay and teacher evaluation for professional development. A number of studies have focused on an analysis of each evaluation system in terms of its advent, development, advantages and disadvantages, but these studies have been critically limited in that they have focused only on the partial integration of the three current teacher evaluation systems, without addressing the problems embedded in each of them. The present study provides a systematic analysis of the three current Korean teacher evaluation systems based on a sound analytical framework and proposes appropriate directions for designing an effective and efficient system. It is found that the three systems share commonalities in terms of stakeholders, evaluators, scope, criteria and methods, further supporting the rationale for developing a single comprehensive teacher evaluation system in Korea. Finally, several steps to establish a comprehensive teacher evaluation system based on the analysis results are suggested.

Background/Aim: The aim of this study was to establish a patient-derived orthotopic xenograft (PDOX) mouse model of liver metastasis of triple-negative breast cancer (TNBC) and examine the efficacy of oral recombinant methioninase (o-rMETase) on the liver metastasis. Materials and Methods: TNBC from a patient was implanted in the left hepatic lobe of nude mice to simulate liver metastasis in a PDOX model. Ten days later, all mice underwent laparotomy to measure tumor size and were randomized to three groups: control; o-rMETase 100 U once daily (qd); and o-rMETase 200 U qd. After 9 days of treatment, all mice were sacrificed. Results: At the end of the treatment period for the liver metastasis, the size of liver metastases was 372.6 mm3 in the control group; 160.0 mm3 in the o-rMETase 100 U group; and 245.3 mm3 in the orMETase 200 U group. All mice had ascites and 12 out of 14 mice in all groups had mesenteric lymph-node metastasis, as re-metastasis. The mean body-condition score was 1.5 in the control group; 2.4 in the o-rMETase 100 U group; and 2.6 in the o-rMETase 200 U group (control group vs. o-rMETase 200 U group, p<0.05). Conclusion: The TNBC liver metastasis was highly aggressive resulting in re-metastasis and ascites. o-rMETase tended to inhibit the liver metastasis and significantly improved the mouse bodycondition score. This new PDOX model of TNBC liver metastasis will be useful for identifying effective agents for this recalcitrant disease. [ABSTRACT FROM AUTHOR]

Background/Aim: The aim of the study was to use a triple-negative breast cancer (TNBC) patient-derived orthotopic xenograft (PDOX) model to examine the efficacy of oral recombinant methioninase (o-rMETase) against this recalcitrant disease. Materials and Methods: The TNBC tumor from a patient was implanted in the right 4th inguinal mammary fat pad of nude mice. Two weeks later, the mice underwent tumorectomy with grossly-negative surgical margins. Two days after tumorectomy the mice were divided in two groups: one control and one treated with o-rMETase. Results: Tumors recurred in all mice. On day 11, the mean recurrent tumor volumes were 936.7 mm³ in the control group and 450.9 mm³ in the orMETase group (p<0.05). On day 15, the mean recurrent tumor volumes were 3392.5 mm³ in the control group and 1603.5 mm³ in the o-rMETase group. The mean recurrent tumor weights were 2.1 g in the control group and 1.1 g in the o-rMETase group on day 15. Conclusion: o-rMETase is an effective adjuvant treatment for aggressive TNBC. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine whether or not "Scaffolded Think-Group-Share" learning can have a positive effect on student satisfaction and learning achievement in English classes of an Indonesian elementary school. To achieve this purpose, this study compared the findings from the two dependent variables (i.e., student satisfaction and English learning achievement) in "Scaffolded Think-Group-Share" learning with those in "Group Investigation" and "Learning Together" learning, which are other types of cooperative learning methods. According to the findings, there were statistically significant differences in student satisfaction and English learning achievement between the Scaffolded Think-Group-Share group, the Group Investigation group, and the Learning Together group. This study implies that "Scaffolded Think-Group-Share" learning has the potential to enhance student satisfaction and comprehension in English as a foreign language (EFL) classes. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the rate, patterns, and risk factors associated with tumor recurrence in patients with T1N0 gastric cancer. Materials and Methods: The medical records of 8,753 patients with pathological T1N0M0 gastric cancer who underwent gastrectomy between 1994 and 2014 at Sungkyunkwan University School of Medicine were examined. Results: Among the 8,753 patients, 95 patients (1.1%) experienced tumor recurrence; this included 31 remnant, 27 hematogenous, 9 lymph nodal, 5 peritoneal, and 23 multiple-site recurrences. When patients were divided into two groups according to the presence of tumor recurrence, the following characteristics were higher in the recurrence group than in the non-recurrence group: older age (≥65 years), male gender, undifferentiated histology, submucosal invasion, and venous invasion. In multivariate analysis, older age, male gender, tumor depth (sm2 and sm3 invasion), and venous invasion were independent risk factors for tumor recurrence. The recurrence rates were 0.7% in patients with less than two risk factors, 1.7% in those with two risk factors, 3.0% in those with three risk factors, and 6.3% in those with four risk factors (P<0.001). Conclusions: Although tumor recurrence is rare in pT1N0M0 gastric cancer, some patients with certain risk factors demonstrate an increased rate of tumor recurrence. Careful follow-up is required for patients with three or four risk factors. [ABSTRACT FROM AUTHOR]

The number of adult learners who participate in online learning has rapidly grown in the last two decades due to online learning's many advantages. In spite of the growth, the high dropout rate in online learning has been of concern to many higher education institutions and organizations. The purpose of this study was to determine whether persistent learners and dropouts are different in individual characteristics (i.e., age, gender, and educational level), external factors (i.e., family and organizational supports), and internal factors (i.e., satisfaction and relevance as sub-dimensions of motivation). Quantitative data were collected from 147 learners who had dropped out of or finished one of the online courses offered from a large Midwestern university. Dropouts and persistent learners showed statistical differences in perceptions of family and organizational support, and satisfaction and relevance. It was also shown that the theoretical framework, which includes family support, organizational support, satisfaction, and relevance in addition to individual characteristics, is able to predict learners' decision to drop out or persist. Organizational support and relevance were shown to be particularly predictive. The results imply that lower dropout rates can be achieved if online program developers or instructors find ways to enhance the relevance of the course. It also implies that adult learners need to be supported by their organizations in order for them to finish online courses that they register for. [ABSTRACT FROM AUTHOR]

The article focuses on the proposal of a new integrated model of technology transfer that includes the components for enhancing the technology transfer in Seoul, Korea. Technology transfer can be successful by integrating the three main aspects of technology which are cultural, organizational, and technical. However, the invisible aspects of technology like knowledge, skills, and organization are more vital than the physical aspect. Moreover, the willingness of the recipient and donor is necessary to be able to assimilate, adopt and generate the new technology.

The article presents a case study which explores the difficulties faced by a novice online instructor. The study delineates the first online teaching experience of an instructor at a big university in the Midwestern U.S. The study finds that online teaching generated some challenges for the instructor which cause her to consider online teaching burdensome. The instructor faced difficulties in communicating with and interacting with students. She had to form new teaching materials to facilitate the interaction and participation of students.

The purpose of this study was to investigate the potential of a constructivist approach to context-based video instruction for enhancing learning. To achieve this purpose, the authors examined whether video-based instruction that was developed using constructivist theory can affect student learning (i.e., comprehension and retention) and motivation (i.e., attention, relevance, confidence, and satisfaction) by comparing learners' perceptions of both video-based instruction and traditional text-based instruction in an online context-based lesson. There was a significant difference in learners' motivation in terms of attention between the video-based instruction and traditional text-based instruction. In addition, the learners reported that the video-based instruction was more memorable than the traditional text-based instruction. This study implies that context-based videos in online courses have the potential to enhance learners' retention and motivation. [ABSTRACT FROM AUTHOR]

The ranked discrepancy model (RDM) is a relatively novel needs assessment approach and is optimized for addressing ordinal and non-normally distributed data. This study aimed to explore the viability of the RDM by comparing the results obtained from it with those obtained using two other long-standing needs assessment models, and to prioritize the learning needs of secondary school career guidance teachers in South Korea using the RDM as an initial effort to improve the pre-service and in-service educational programs of teachers. Data were collected from 75 career guidance teachers by using a survey questionnaire. The results from the RDM, the weighted total index (WTI) approach, and the Borich model demonstrated a great deal of consistency in terms of the rankings of career guidance teachers’ learning needs. This implies that the RDM is a useful quantitative method for needs assessment in cases involving ordinal items, cross-sectional data, or non-normally distributed data. This study also revealed that “providing and utilizing occupational information” is the biggest shortfall among the job tasks required of secondary school career guidance teachers, compared to its importance. Uncertainty about the future might make it more difficult for career guidance teachers to provide students with the appropriate occupational guidance.