Seokhwan Ko

Mr. Seokhwan Ko

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 January 2024 in Life
Verified
Journal Article
Open access
PDF file
SKSijin Kim
Sijin Kim
KHKazi Rakib Hasan
Kazi Rakib Hasan
YAYu Ando
Yu Ando
SKSeokhwan Ko
Seokhwan Ko
DLDonghyeon Lee
Donghyeon Lee
JCJunghwan Cho
Junghwan Cho
Tumor microenvironment (TME) plays a pivotal role in immuno-oncology, which investigates the intricate interactions between tumors and the human immune system. Specifically, tumor-infiltrating lymphocytes (TILs) are crucial biomarkers for evaluating the prognosis of breast cancer patients and have the potential to refine immunotherapy precision and accurately identify tumor cells in specific cancer types. In this study, we conducted tissue segmentation and lymphocyte detection tasks to predict TIL scores by employing self-supervised learning (SSL) model-based approaches capable of addressing limited labeling data issues. Our experiments showed a 1.9% improvement in tissue segmentation and a 2% improvement in lymphocyte detection over the ImageNet pre-training model. Using these SSL-based models, we achieved a TIL score of 0.718 with a 4.4% improvement. In particular, when trained with only 10% of the entire dataset, the SwAV pre-trained model exhibited a superior performance over other models. Our work highlights improved tissue segmentation and lymphocyte detection using the SSL model with less labeled data for TIL score prediction.

4 June 2024 in Bioengineering
Verified
Journal Article
Open access
PDF file
YAYu Ando
Yu Ando
JCJunghwan Cho
Junghwan Cho
NPNora Jee-Young Park
Nora Jee-Young Park
SKSeokhwan Ko
Seokhwan Ko
HHHyung-Soo Han
Hyung-Soo Han
Screening is critical for prevention and early detection of cervical cancer but it is time-consuming and laborious. Supervised deep convolutional neural networks have been developed to automate pap smear screening and the results are promising. However, the interest in using only normal samples to train deep neural networks has increased owing to the class imbalance problems and high-labeling costs that are both prevalent in healthcare. In this study, we introduce a method to learn explainable deep cervical cell representations for pap smear cytology images based on one-class classification using variational autoencoders. Findings demonstrate that a score can be calculated for cell abnormality without training models with abnormal samples, and we localize abnormality to interpret our results with a novel metric based on absolute difference in cross-entropy in agglomerative clustering. The best model that discriminates squamous cell carcinoma (SCC) from normals gives 0.908±0.003 area under operating characteristic curve (AUC) and one that discriminates high-grade epithelial lesion (HSIL) 0.920±0.002 AUC. Compared to other clustering methods, our method enhances the V-measure and yields higher homogeneity scores, which more effectively isolate different abnormality regions, aiding in the interpretation of our results. Evaluation using an external dataset shows that our model can discriminate abnormality without the need for additional training of deep models.

9 March 2023 in Medicina
Verified
Journal Article
Open access
PDF file
JKJinhee Kim
Jinhee Kim
SKSeokhwan Ko
Seokhwan Ko
MKMoonsik Kim
Moonsik Kim
NPNora Jee-Young Park
Nora Jee-Young Park
HHHyung-Soo Han
Hyung-Soo Han
JPJi Young Park
Ji Young Park
Background and objectives: Telomerase reverse transcriptase (TERT) promoter mutation, found in a subset of patients with thyroid cancer, is strongly associated with aggressive biologic behavior. Predicting TERT promoter mutation is thus necessary for the prognostic stratification of thyroid cancer patients. Materials and Methods: In this study, we evaluate TERT promoter mutation status in thyroid cancer through the deep learning approach using histologic images. Our analysis included 13 consecutive surgically resected thyroid cancers with TERT promoter mutations (either C228T or C250T) and 12 randomly selected surgically resected thyroid cancers with a wild-type TERT promoter. Our deep learning model was created using a two-step cascade approach. First, tumor areas were identified using convolutional neural networks (CNNs), and then TERT promoter mutations within tumor areas were predicted using the CNN–recurrent neural network (CRNN) model. Results: Using the hue–saturation–value (HSV)-strong color transformation scheme, the overall experiment results show 99.9% sensitivity and 60% specificity (improvements of approximately 25% and 37%, respectively, compared to image normalization as a baseline model) in predicting TERT mutations. Conclusions: Highly sensitive screening for TERT promoter mutations is possible using histologic image analysis based on deep learning. This approach will help improve the classification of thyroid cancer patients according to the biologic behavior of tumors.

21 May 2025 in Computers in Biology and Medicine
Verified
Journal Article
Closed access
SKSeokhwan Ko
Seokhwan Ko
YAYu Ando
Yu Ando
MKMoonsik Kim
Moonsik Kim
NPNora Jee-Young Park
Nora Jee-Young Park
HHHyung-Soo Han
Hyung-Soo Han
JCJunghwan Cho
Junghwan Cho

28 November 2024 in Life
Verified
Journal Article
Open access
PDF file
JCJae Woo Chun
Jae Woo Chun
YAYu Ando
Yu Ando
SKSeokhwan Ko
Seokhwan Ko
GCGun Oh Chong
Gun Oh Chong
JPJi Young Park
Ji Young Park
JCJunghwan Cho
Junghwan Cho
Cervical cancer is a significant health challenge, yet it can be effectively prevented through early detection. Cytology-based screening is critical for identifying cancerous and precancerous lesions; however, the process is labor-intensive and reliant on trained experts to scan through hundreds of thousands of mostly normal cells. To address these challenges, we propose a novel distribution-augmented approach using contrastive self-supervised learning for detecting abnormal squamous cervical cells from cytological images. Our method utilizes color augmentations to enhance the model’s ability to differentiate between normal and high-grade precancerous cells; specifically, high-grade squamous intraepithelial lesions (HSILs) and atypical squamous cells–cannot exclude HSIL (ASC-H). Our model was trained exclusively on normal cervical cell images and achieved high diagnostic accuracy, demonstrating robustness against color distribution shifts. We employed kernel density estimation (KDE) to assess cell type distributions, further facilitating the identification of abnormalities. Our results indicate that our approach improves screening accuracy and reduces the workload for cytopathologists, contributing to more efficient cervical cancer screening programs.