• 대한핵의학회:학술대회논문집
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• 2002.05a
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• pp.17-24
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• 2002

Recurrence of colorectal cancer after apparently curative resection remains common, with reported relapse rates of up to 40%. Because complete resection of solitary metastases or local recurrence may improve long-term survival, surgical management of such cases has become increasingly aggressive but has led to only modest survival benefit. The limitations of current approaches based on structural imaging are well documented, with over half of the patients who are thought suitable for curative surgery being found to have unresectable disease at operation. Therefore, better preoperative assessment is crucial. The increasing use of FDG-PET as an oncologic staging investigation has significantly improved the assessment of patients with suspected colorectal cancer recurrence. Several studios show that substantial and largely appropriate changes in patient management occur, often soaring patients the significant morbidity and mortality associated with aggressive but futile therapies while also saving scarce community resources. Nevertheless, the clinical relevance of these findings has still been questioned. The utility of PET in routine clinical practice will likely depend on its ability to provide incremental information compared with CT in selected patients rather than to serve as a replacement for CT. In conclusion, in patients with suspected recurrent or metastatic colorectal carcinoma, FDG-PET should be performed (1) when there is rising carcinoembryonic antigen levels in the absence of a known source, (2) to increase the specificity of structural imaging when there is an equivocal lesion, and (3) as a screening method for the entire body in the preoperative staging before curative resection of recurrent disease.

• Korean Journal of Digital Imaging in Medicine
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• v.17 no.1
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• pp.19-31
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• 2015

최근 우리나라의 암 발생률은 꾸준히 증가추세에 있고 그 중에서도 전립선암은 갑상선암을 제외했을 때 남성에서 가장 높은 증가 추세를 보이고 있는 암이다. 전립선암은 그 동안 선진국에서 주로 발병하는 것으로 알려진 암 종이지만 서구화된 식습관과 생활 행태 변화로 인하여 국내에서도 발생률이 증가하는 것으로 추정하고 있다. 따라서 국내 환경에 맞는 내장 지방 분포와 같은 정확한 비만도 측정을 통해 우리나라에서 증가율 1위를 보이고 있는 전립선암 발생의 원인 관계를 찾고자 한다. 본 연구는 환자와 정상군 비교를 하는 환자-대조군 연구이고 본 연구를 위하여 임상시험 윤리위원회 (IRB) 승인을 받았다 (NCC2014-0124). 환자군은 2014년 8월 1일부터 2015년 1월 6일 까지 국립암센터를 방문하여 전립선암을 진단받고 수술과 항암치료 그리고 방사선 치료를 시작하지 않은 초진을 대상으로 하였고, 정상군은 2009년 11월부터 2014년 9월 30일까지 공단검진을 목적으로 국립암센터를 방문한 정상인을 대상으로 하였다. 전립선암 연구는 환자 총 52명에 평균 66세 (51 - 82세)이고 정상군은 총 50명에 평균 64세 (59 - 75세) 이다. 모든 연구 대상자들의 생활 요인 평가를 위하여 암 가족력, 흡연, 음주 상태, 운동, 등을 추가적으로 설문 조사하였다. MRI 영상의 배꼽 주위에서의 내장 지방과 피하지방을 전용 분석 컴퓨터를 활용하여 측정 하였다. 복부비만율은 환자군과 정상군에서뿐만 아니라 (p = 0.03), 전립선암 악성도와 (Gleasonscore; p = 0.001)도 통계적 차이를 나타냈다. 하지만 BMI 결과와는 전립선암 발생과 악성도에서 무관함을 보인 것에 반해 허리둘레는 전립선암의 발생에 영향을 미치는 결과를 나타났다. 한편 전립선암의 또 다른 악성도 지표인 PSA는 비만 측정치와의 상관성이 Gleason score와 보다 대체적으로 낮게 나타났다. 학력, 운동량, 흡연, 음주 상태와 같은 생활 특성에 따른 전립선암 발생의 영향 관계는 뚜렷하지 않았다. 결론적으로 본 연구를 통해서 전립선암의 발생 위험도와 악성도 지표로 복부 비만도가 유용함을 나타냈고 간단한 신체 계측 지표 활용으로는 BMI보다 허리둘레 측정치가 더 암 발생의 연관성이 높음을 보였다.

• Radiation Oncology Journal
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• v.34 no.1
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• pp.64-75
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• 2016

Purpose: In order to evaluate the relationship between the dose to the liver parenchyma and focal liver reaction (FLR) after stereotactic ablative body radiotherapy (SABR), we suggest a novel method using a three-dimensional dose distribution and change in signal intensity of gadoxetate disodium-gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) hepatobiliary phase images. Materials and Methods: In our method, change of the signal intensity between the pretreatment and follow-up hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was calculated and then threshold dose (TD) for developing FLR was obtained from correlation of dose with the change of the signal intensity. For validation of the method, TDs for six patients, who had been treated for liver cancer with SABR with 45-60 Gy in 3 fractions, were calculated using the method, and we evaluated concordance between volume enclosed by isodose of TD by the method and volume identified as FLR by a physician. Results: The dose to normal liver was correlated with change in signal intensity between pretreatment and follow-up MRI with a median $R^2$ of 0.935 (range, 0.748 to 0.985). The median TD by the method was 23.5 Gy (range, 18.3 to 39.4 Gy). The median value of concordance was 84.5% (range, 44.7% to 95.9%). Conclusion: Our method is capable of providing a quantitative evaluation of the relationship between dose and intensity changes on follow-up MRI, as well as determining individual TD for developing FLR. We expect our method to provide better information about the individual relationship between dose and FLR in radiotherapy for liver cancer.

• Journal of Gastric Cancer
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• v.19 no.2
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• pp.225-233
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• 2019

Purpose: Gastric adenocarcinoma of the fundic gland type (chief cell predominant type) (GA-FG-CCP) was first reported as a rare adenocarcinoma found in the normal fundic mucosa. Recent studies have proposed the possibility that GA-FG-CCPs were also generated in the atrophic mucosa after Helicobacter pylori (HP) eradication therapy. However, little is known on the endoscopic findings of GA-FG-CCP generated in the atrophic mucosa due to its extreme rarity. Materials and Methods: A total of 8 patients who underwent endoscopic submucosal resection and were diagnosed with GA-FG-CCP generated in the HP-uninfected mucosa (4 cases, HP-uninfected group) or HP-eradicated atrophic mucosa (4 cases, HP-eradicated group) were retrospectively analyzed, and their endoscopic findings, including magnifying endoscopy with narrow band imaging (M-NBI), and pathological features were compared. Results: While GA-FG-CCPs in the 2 groups displayed similar macroscopic appearance, M-NBI demonstrated that characteristic microvessels (tapered microvessels like withered branches) were specifically identified in the HP-eradicated group. Pathological investigation revealed that a decreasing number of fundic glands and thinned foveolar epithelium covering tumor ducts were thought to lower the thickness of the covering layer over tumor ducts in the HP-eradicated group. Moreover, dilation of vessels just under the surface of the lesions contributed to the visualization of microvessels by M-NBI. Conclusions: The change in background mucosa due to HP infection influenced the thickness of the covering layer over the tumor ducts and M-NBI finding of GA-FG-CCP.

• Current Optics and Photonics
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• v.3 no.3
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• pp.256-262
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• 2019

Extensive tumor resection accompanied by radiotherapy and chemotherapy is the standard of care for malignant gliomas. However, there is a significant obstacle to the complete resection of the tumor due to the difficulty of distinguishing tumor and normal brain tissue with a conventional surgical microscope. Recently, multiple studies have shown the possibility of fluorescence-guided surgery in malignant gliomas. The most used fluorescence dyes for brain tumor surgery are 5-aminolevulinic acid (5-ALA) and indocyanine green (ICG). In this paper, a new fluorescence guided operation system, which can detect both 5-ALA and ICG fluorescent images simultaneously, is presented. This operation system consists of light emitting diodes (LEDs) which emits 410 nm and 740 nm wavelengths. We have performed experiments on rats in order to verify the operation of the newly developed operation system. Oral administration and imaging were performed to observe the fluorescence of 5-ALA and ICG fluorescence in rats. When LEDs at wavelengths of 410 nm and 740 nm were irradiated on rats, 628 nm wavelength with a violet fluorescence color and 825 nm wavelength with a red fluorescence color were expressed in 5-ALA and ICG fluorescent material, respectively, thus we were able to distinguish the tumor tissues easily. Previously, due to the poor resolution of the conventional surgical microscope and the fact that the color of the vein is similar to that of the tumor, the tumor resection margin was not easy to observe, thus increasing the likelihood for cancer recurrence. However, when the tumor is observed through the fluorescence guided operation system, it is possible to easily distinguish the color with the naked eye and it can be completely removed. Therefore, it is expected that surgical removal of cancerous tumors will be possible and surgical applications and surgical microscopes for cancer tumor removal surgery will be promising in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.474-476
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• 2021

Glioblastoma is the most common brain malignancies arising from glial cells. Early diagnosis and treatment plan establishment are important, and cancer is diagnosed mainly through T1CE imaging through injection of a contrast agent. However, the risk of injection of gadolinium-based contrast agents is increasing recently. Region segmentation that marks cancer regions in medical images plays a key role in CAD systems, and deep neural network models for synthesizing new images are also being studied. In this study, we propose a model that simultaneously learns the generation of T1CE images and segmentation of cancer regions. The performance of the proposed model is evaluated using similarity measurements including mean square error and peak signal-to-noise ratio, and shows average result values of 21 and 39 dB.

• Journal of the Korean Society of Radiology
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• v.85 no.3
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• pp.637-642
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• 2024

Rectal syphilis is a rare form of syphilis presentation and its symptoms, endoscopic and radiologic findings are nonspecific. Rectal syphilis typically presents with features such as concentric rectal wall thickening, mucosal hyperemia, perirectal fat stranding, and lymphadenopathy. Rectal cancer exhibits asymmetric wall thickening and lymph node necrosis, aiding in the differentiation between these two diseases. However, due to the considerable overlap in their respective manifestations, distinguishing between rectal syphilis and rectal cancer is extremely challenging without considering the patient's medical history. Rectal syphilis often leads to unnecessary tests or delayed treatment, as it can be mistaken for other benign diseases such as inflammatory bowel diseases in addition to rectal cancer. In this case report, we aim to provide a detailed report on the endoscopic, imaging, and pathological findings based on our experience with a case of suspected rectal malignancy that turned out to be rectal syphilis.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.99-108
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• 2021

Purpose: The goal of this study is to evaluate usefulness of noninvasive method instead of previous inserting Fiducial Marker Method when performing Stereotactic Partial Breast Irradiation in CyberKnife. Material and methods: For consistency of Imaging Center, we evaluated both oblique images at angle 45 and 315 acquired from 2D Simulator and CyberKnife quantitatively through dice similarity coefficient. Also, location reproducibility of Surface Fiducial Marker was analyzed from 2D Simulator, treatment plans and CyberKinfe images by using 8 Fiducial Markers made of gold attached to ATOM Phantom based on our institution's protocols. Results: The results of the estimated consistency were 0.87 and 0.9 at the oblique angle 45 and 315, respectively. For location consistency of Surface Fiducial Markers, values of horizontal vertical direction of left breast were Superior/Inferior 0.3 mm, Left/Right -0.3 mm, Anterior/Posterior 0.4 mm, and the values of rotational direction were Roll 0.3 °, Pitch 0.2 °, Yaw 0.4 °. The values of horizontal vertical direction of right breast were Superior/Inferior -0.1 mm, Left/Right -0.1 mm, Anterior/Posterior -0.1 mm, and the values of rotational direction were Roll 0.2°, Pitch 0.1°, Yaw 0.1°. Conclusions: We expect that the protocols used by Surface Fiducial Markers when performing Stereotactic Partial Breast Irradiation in CyberKnife will provide protection from pain and cut expenses for treatment and reduce treatment errors and make treatment more accurate by suggesting treatment protocols based on high consistency of Imaging Center and reproducibility of Fiducial Markers.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2627-2630
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• 2013

Background: Ovarian cancer continues to pose a major challenge to physicians and radiologists. It is the third most common gynecologic malignancy and estimated to be fifth leading cancer cause of death in women, constituting 23% of all gynecological malignancies. Multi-detector computed tomography (MDCT) appears to offer an excellent modality in diagnosing ovarian cancer based on combination of its availability, meticulous technique, efficacy and familiarity of radiologists and physicians. The aim of this study was to compute sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of 64-slice MDCT in classifying ovarian masses; 95% confidence intervals were reported. Materials and Methods: We prospectively designed a cross-sectional analytical study to collect data from July 2010 to August 2011 from a tertiary care hospital in Karachi, Pakistan. A sample of 105 women aged between 15-80 years referred for 64-MDCT of abdomen and pelvis with clinical suspicion of malignant ovarian cancer, irrespective of stage of disease, were enrolled by non-probability purposive sampling. All patients who were already known cases of histologically proven ovarian carcinoma and having some contraindication to radiation or iodinated contrast media were excluded. Results: Our prospective study reports sensitivity, specificity; positive and negative predictive values with 95%CI and accuracy were computed. Kappa was calculated to report agreement among the two radiologists. For reader A, MDCT was found to have 92% (0.83, 0.97) sensitivity and 86.7% (0.68, 0.96) specificity, while PPV and NPV were 94.5% (0.86, 0.98) and 86.7% (0.63, 0.92), respectively. Accuracy reported by reader A was 90.5%. For reader B, sensitivity, specificity, PPV and NPV were 94.6% (0.86, 0.98) 90% (0.72, 0.97) 96% (0.88, 0.99) and 87.1% (0.69, 0.95) respectively. Accuracy computed by reader B was 93.3%. Excellent agreement was found between the two radiologists with a significant kappa value of 0.887. Conclusion: Based on our study results, we conclude MDCT is a reliable imaging modality in diagnosis of ovarian masses accurately with insignificant interobserver variability.

• Investigative Magnetic Resonance Imaging
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• v.23 no.1
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• pp.46-54
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• 2019

Purpose: The aim of this study was to evaluate the diagnostic performance of a computer-aided detection (CAD) system used with automated breast ultrasonography (ABUS) for suspicious lesions detected on breast MRI, and CAD-false lesions. Materials and Methods: We included a total of 40 patients diagnosed with breast cancer who underwent ABUS (ACUSON S2000) to evaluate multiple suspicious lesions found on MRI. We used CAD ($QVCAD^{TM}$) in all the ABUS examinations. We evaluated the diagnostic accuracy of CAD and analyzed the characteristics of CAD-detected lesions and the factors underlying false-positive and false-negative cases. We also analyzed false-positive lesions with CAD on ABUS. Results: Of a total of 122 suspicious lesions detected on MRI in 40 patients, we excluded 51 daughter nodules near the main breast cancer within the same quadrant and included 71 lesions. We also analyzed 23 false-positive lesions using CAD with ABUS. The sensitivity, specificity, positive predictive value, and negative predictive value of CAD (for 94 lesions) with ABUS were 75.5%, 44.4%, 59.7%, and 62.5%, respectively. CAD facilitated the detection of 81.4% (35/43) of the invasive ductal cancer and 84.9% (28/33) of the invasive ductal cancer that showed a mass (excluding non-mass). CAD also revealed 90.3% (28/31) of the invasive ductal cancers measuring larger than 1 cm (excluding non-mass and those less than 1 cm). The mean sizes of the true-positive versus false-negative mass lesions were $2.08{\pm}0.85cm$ versus $1.6{\pm}1.28cm$ (P < 0.05). False-positive lesions included sclerosing adenosis and usual ductal hyperplasia. In a total of 23 false cases of CAD, the most common (18/23) cause was marginal or subareolar shadowing, followed by three simple cysts, a hematoma, and a skin wart. Conclusion: CAD with ABUS showed promising sensitivity for the detection of invasive ductal cancer showing masses larger than 1 cm on MRI.