• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6811-6817
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• 2014

Background: Breast cancer risk prediction models are widely used in clinical practice. They should be useful in identifying high risk women for screening in limited-resource countries. However, previous models showed poor performance in derived and validated settings. Therefore, we aimed to develop and validate a breast cancer risk prediction model for Thai women. Materials and Methods: This cross-sectional study consisted of derived and validation phases. Data collected at Ramathibodi and other two hospitals were used for deriving and externally validating models, respectively. Multiple logistic regression was applied to construct the model. Calibration and discrimination performances were assessed using the observed/expected ratio and concordance statistic (C-statistic), respectively. A bootstrap with 200 repetitions was applied for internal validation. Results: Age, menopausal status, body mass index, and use of oral contraceptives were significantly associated with breast cancer and were included in the model. Observed/expected ratio and C-statistic were 1.00 (95% CI: 0.82, 1.21) and 0.651 (95% CI: 0.595, 0.707), respectively. Internal validation showed good performance with a bias of 0.010 (95% CI: 0.002, 0.018) and C-statistic of 0.646(95% CI: 0.642, 0.650). The observed/expected ratio and C-statistic from external validation were 0.97 (95% CI: 0.68, 1.35) and 0.609 (95% CI: 0.511, 0.706), respectively. Risk scores were created and was stratified as low (0-0.86), low-intermediate (0.87-1.14), intermediate-high (1.15-1.52), and high-risk (1.53-3.40) groups. Conclusions: A Thai breast cancer risk prediction model was created with good calibration and fair discrimination performance. Risk stratification should aid to prioritize high risk women to receive an organized breast cancer screening program in Thailand and other limited-resource countries.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4929-4932
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• 2014

Objective: To compare the mammogarphic appearance between breast cancer patients aged <40 and ${\geq}40$ years. Methods: Needle localization and biopsy of suspicious mammographic lesions identified 1,959 breast carcinomas in a single institution from Jun 2012 to Apr 2013. According to the age, we divided patients into two groups: <40 and ${\geq}40$ years old, and analyzed mammographic appearance separately. Results: Young patients had 44.2% foci with calcification, but old patients only had 39.4% (P<0.001). In younger group, the ratios of cases according to mass density were 41.8% or higher, 58.2% equivalent and lower. In older group, the ratios were 55.5 % and 44.5%, respectively. There were statistical differences between high density and others (P<0.05). The ratios of cases according to mass margin were 13.9% circumscribed and microlobulated, 86.1% indistinct and spiculated in the younger group, as compared to 6.5% and 93.5%, respectively, in the older group (P<0.05). Conclusions: Mammographic findings differ between young and old patients with breast cancer, for example regarding mass density, mass margin and microcalcification ratios.

• Journal of Biomedical Engineering Research
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• v.38 no.3
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• pp.116-122
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• 2017

Physical breast phantoms would be useful for the development of a dedicated breast computed tomography (BCT) system and its optimization. While the conventional breast phantoms are available in compressed forms, which are appropriate for the mammography and digital tomosynthesis, however, the BCT requires phantoms in uncompressed forms. Although simple cylindrical plastic phantoms can be used for the development of the BCT system, they will not replace the roles of uncompressed phantoms describing breast anatomies for a better study of the BCT. In this study, we have designed a numerical voxel breast phantom accounting for the random nature of breast anatomies and applied it to the 3D printer to fabricate the uncompressed anthropomorphic breast phantom. The numerical voxel phantom mainly consists of the external skin and internal anatomies, including the ductal networks, the glandular tissues, the Cooper's ligaments, and the adipose tissues. The voxel phantom is then converted into a surface data in the STL file format by using the marching cube algorithm. Using the STL file, we obtain the skin and the glandular tissue from the 3D printer, and then assemble them. The uncompressed breast phantom is completed by filling the remaining space with oil, which mimics the adipose tissues. Since the breast phantom developed in this study is completely software-generated, we can create readily anthropomorphic phantoms accounting for diverse human breast anatomies.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.2059-2065
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• 2013

This goal of this research was to evaluate the cost-effectiveness of the National Cancer Screening Program (NCSP) for breast cancer in the Republic of Korea from a government expenditure perspective. In 2002-2003 (baseline), a total of 8,724,860 women aged 40 years or over were invited to attend breast cancer screening by the NCSP. Those who attended were identified using the NCSP database, and women were divided into two groups, women who attended screening at baseline (screened group) and those who did not (non-screened group). Breast cancer diagnosis in both groups at baseline, and during 5-year follow-up was identified using the Korean Central Cancer Registry. The effectiveness of the NCSP for breast cancer was estimated by comparing 5-year survival and life years saved (LYS) between the screened and the unscreened groups, measured using mortality data from the Korean National Health Insurance Corporation and the National Health Statistical Office. Direct screening costs, indirect screening costs, and productivity costs were considered in different combinations in the model. When all three of these costs were considered together, the incremental cost to save one life year of a breast cancer patient was 42,305,000 Korean Won (KW) (1 USD=1,088 KW) for the screened group compared to the non-screened group. In sensitivity analyses, reducing the false-positive rate of the screening program by half was the most cost-effective (incremental cost-effectiveness ratio, ICER=30,110,852 KW/LYS) strategy. When the upper age limit for screening was set at 70 years, it became more cost-effective (ICER=39,641,823 KW/LYS) than when no upper age limit was set. The NCSP for breast cancer in Korea seems to be accepted as cost-effective as ICER estimates were around the Gross Domestic Product. However, cost-effectiveness could be further improved by increasing the sensitivity of breast cancer screening and by setting appropriate age limits.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9101-9105
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• 2014

Background: The purpose of this study was to compare the accuracy and effectiveness of automated breast volume scanning (ABVS) and hand-held ultrasound (HHUS) in the detection of breast cancer in a large population group with a long-term follow-up, and to investigate whether different ultrasound systems may influence the estimation of cancer detection. Materials and Methods: Institutional review board approval was obtained for this retrospective study, and informed consent was waived. From September 2010 to August 2011, a total of 1,866 ABVS and 3,700 HHUS participants, who underwent these procedures at our institute, were included in this study. Cancers occurring during the study and subsequent follow-up were evaluated. The reference standard was a combination of histology and follow-up imaging (${\geq}12months$). The recall rate, cancer detection yield, diagnostic accuracy, sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were calculated with exact 95% confidence intervals. Results: The recall rate was 2.57 per 1,000 (48/1,866) for ABVS and 3.57 per 1,000 (132/3,700) for HHUS, with a significant difference (p=0.048). The cancer detection yield was 3.8 per 1,000 for ABVS and 2.7 per 1,000 for HHUS. The diagnostic accuracy was 97.7% for ABVS and 96.5% for HHUS with statistical significance (p=0.018). The specificity of ABVS and HHUS were 97.8%, 96.7%, respectively (p=0.022). Conclusions: ABVS shows a comparable diagnostic performance to HHUS. ABVS is an effective supplemental tool for mammography in breast cancer detection in a large population.

• Investigative Magnetic Resonance Imaging
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• v.21 no.4
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• pp.233-241
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• 2017

Purpose: To report on the current practices in breast magnetic resonance imaging (MRI) in Korea. Materials and Methods: We invited the 68 members of the Korean Society of Breast Imaging who were working in hospitals with available breast MRI to participate in a survey on how they performed and interpreted breast MRI. We asked one member from each hospital to respond to the survey. A total of 22 surveys from 22 hospitals were analyzed. Results: Out of 22 hospitals, 13 (59.1%) performed at least 300 breast MRI examinations per year, and 5 out of 22 (22.7%) performed > 1200 per year. Out of 31 machines, 14 (45.2%) machines were 1.5-T scanners and 17 (54.8%) were 3.0-T scanners. All hospitals did contrast-enhanced breast MRI. Full-time breast radiologists supervised the performance and interpreted breast MRI in 19 of 22 (86.4%) of hospitals. All hospitals used BI-RADS for MRI interpretation. For computer-aided detection (CAD), 13 (59.1%) hospitals sometimes or always use it and 9 (40.9%) hospitals did not use CAD. Two (9.1%) and twelve (54.5%) hospitals never and rarely interpreted breast MRI without correlating the mammography or ultrasound, respectively. The majority of respondents rarely (13/21, 61.9%) or never (5/21, 23.8%) interpreted breast MRI performed at an outside facility. Of the hospitals performing contrast-enhanced examinations, 15 of 22 (68.2%) did not perform MRI-guided interventional procedures. Conclusion: Breast MRI is extensively performed in Korea. The indication and practical patterns are diverse. The information from this survey would provide the basis for the development of Korean breast MRI practice guidelines.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6285-6288
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• 2015

Background: Breast cancer is commonly diagnosed at late stages in countries with limited resources. In Morocco, breast cancer is ranked the first female cancer (36.1%) and screening methods could reduce the proportion presenting with a late diagnosis. Morocco is currently adopting a breast cancer screening program based on clinical examination at primary health facilities, diagnosis at secondary level and treatment at tertiary level. So far, there is no systematic information on the performance of the screening program for breast cancer in Morocco. The aim of this study was to analyze early performance indicators. Materials and Methods: A retrospective evaluative study conducted in Temara city. The target population was the entire female population aged between 45-70 years. The study was based on process and performance indicators collected at the individual level from the various health structures in Tamara between 2009 and 2011. Results: A total of 2,350 women participated in the screening program; the participation rate was 35.7%. Of these, 76.8% (1,806) were married and 5.2% (106) of this group had a family history of breast cancer. Of the women who attended screening, 9.3% (190) were found to have an abnormal physical examination findings. A total of 260 (12.7%) were referred for a specialist consultation. The positive predictive value of clinical breast examination versus mammography was 23.0%. Forty four (35.5%) of the lesions found on the mammograms were classified as BI-RADs 3; 4 or 5 category. Cancer was found in 4 (1.95%) of the total number of screened women and benign cases represented 0.58%. Conclusions: These first results of the programme are very encouraging, but there is a need to closely monitor performance and to improve programme procedures with the aim of increasing both the participation rate and the proportion of women eligible to attend screening.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.4
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• pp.7-14
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• 2012

A image quality is limited by a sample-and-hold circuit of the X-ray CMOS image sensor even though simple mos switch or bootstrapped clock circuit are used to get high quality sampled signal. Because distortion of sampled signal is produced by the charge injection from sample-and-hold circuit even using bootstrapped. This paper presents the 3D micro-inductor design methode in the CMOS process. Using this methode, it is possible to increase the ENOB (effective number of bit) through the use of micro-inductor which is calculated and designed in standard CMOS process in this paper. The ENOB is improved 0.7 bit from 17.64 bit to 18.34 bit without any circuit just by optimized inductor value resulting in verified simulation result. Because of this feature, micro-inductor methode suggested in this paper is able to adapt a mamography that is needed high resolution so that it help to decrease patients dose amount.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.179-184
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• 2010

A hard X-ray microscope system for obtaining images of nano-spatial resolution has been widely studied and requires monochromatic X-ray. A multilayer mirror of 84% reflectivity was designed to acquire tungsten characteristic X-ray of 8.4 keV from the white beam generated from an X-ray tube, and the C/W multilayer mirror of $50{\times}50\;mm$ size and 5.65 nm d-spacing was fabricated by the ion-beam sputtering system. The C/W multilayer had a uniformity of 99.5%, and the structure of the multilayer mirror was verified by a TEM image. The obtainable x-ray reflectivity for the C/W multilayer mirror at 8.4 keV was estimated from measuring the X-ray reflectivity using the copper characteristic X-ray of 8.05 keV. Monochromatic X-ray of 8.4 keV was generated by combining a X-ray tube, and the reflectivity and monochromaticity were 77.1% and 0.21 keV, respectively. Monochromatic X-ray generated from the combination of an X-ray tube and an C/W multilayer mirror has enough potential to use X-ray source for hard X-ray microscope system of laboratory size. If the C/W multilayer mirror of d-spacing of a few nanometers can be fabricated, monochromatic X-ray corresponded to 17.5 keV, molybdenum characteristic X-ray, can be obtained and applied to mammography in the medical application.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2165-2168
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• 2014

Background: Today, survival rate of patients with chronic renal failure/hemodialysis has increased so that chronic illnesses are more likely to occur. Cancer is the main cause of morbidity and mortality in such patients. Aim: In this study, physician attitudes were examined about cancer screening in patients with renal failure. Materials and Methods: This study was done by face to face questionnaire in the $27^{th}$ National Nephrology Congress to determine if the physicians dealing with chronic renal failure, hemodialysis or renal transplanted patients, recommend cancer screening or not and the methods of screening for cervix, prostate, breast and colon cancer. Results: One hundred and fifty six physicians were included in the survey. A total of 105 (67%) participants were male and the age of responders was $48{\pm}9$ years. About 29% were specialists in nephrology, 28% internal medicine, and 5% were other areas of expertise. Some 48% of participants were hemodialysis certified general practitioners. Patients were grouped as compensated chronic renal failure, hemodialysis or renal transplanted. Of the 156 responders, 128 (82%) physicians recommended breast cancer screening and the most recommended subgroup was hemodialysis patients (15%). The most preferred methods of screening were combinations of mammography, self breast examination and physicianbreast examination. 112 (72%) physicians recommended cervix cancer screening, and the most preferred method of screening was pap-smear. Colon cancer screening was recommended by 102 (65%) physicians and prostate screening by 109 (70%) physicians. The most preferred methods of screening were fecal occult blood test and PSA plus rectal digital test, respectively. Conclusions: It is not obvious whether cancer screening in renal failure patients is different from the rest of society. There is a variety of screening methods. An answer can be found to these questions as a result of studies by a common follow-up protocol and cooperation of nephrologists and oncologists.