1.Higher Microbial Abundance and Diversity in Bronchus-Associated Lymphoid Tissue Lymphomas Than in Non-cancerous Lung Tissues
Jung Heon KIM ; Jae Sik KIM ; Noorie CHOI ; Jiwon KOH ; Yoon Kyung JEON ; Ji Hyun CHANG ; Eung Soo HWANG ; Il Han KIM
Cancer Research and Treatment 2025;57(2):580-589
Purpose:
It is well known that the majority of the extranodal marginal zone lymphomas of mucosa-associated lymphoid tissues (MALT lymphomas) are associated with microbiota, e.g., gastric MALT lymphoma with Helicobacter pylori. In general, they are very sensitive to low-dose radiotherapy and chemotherapeutic agents. The microbiota profile is not clearly elucidated in bronchus-associated lymphoid tissue (BALT) lymphoma, a rare type of MALT lymphoma in the lung. Thus, this study aimed to clarify the intratumor microbiome in BALT lymphoma using the third-generation next-generation sequencing (NGS) method.
Materials and Methods:
DNAs were extracted from 12 formalin-fixed paraffin-embedded (FFPE) tumor tissues obtained from BALT lymphoma patients diagnosed between 1990 and 2016. 16S rRNA gene was amplified by polymerase chain reaction. Amplicons were sequenced using a Nanopore platform. Next-generation sequencing analysis was performed to assess microbial profiles. For comparison, FFPE specimens from nine non-cancerous lung tissues were also analyzed.
Results:
Specific bacterial families including Burkholderiaceae, Bacillaceae, and Microbacteriaceae were associated with BALT lymphoma by a linear discriminant analysis effect size approach. Although the number of specimens was limited, BALT lymphomas exhibited significantly higher microbial abundance and diversity with distinct microbial composition patterns and correlation networks than non-cancerous lung tissues.
Conclusion
This study provides the first insight into intratumor microbiome in BALT lymphoma using the third-generation NGS method. A distinct microbial composition suggests the presence of a unique tumor microenvironment of BALT lymphoma.
2.Role of HIF-1α in the Responses of Tumors to Radiotherapy and Chemotherapy
Chang W SONG ; Hyunkyung KIM ; Mi-Sook KIM ; Heon J PARK ; Sun-Ha PAEK ; Stephanie TEREZAKIS ; L Chinsoo CHO
Cancer Research and Treatment 2025;57(1):1-10
Tumor microenvironment is intrinsically hypoxic with abundant hypoxia-inducible factors-1α (HIF-1α), a primary regulator of the cellular response to hypoxia and various stresses imposed on the tumor cells. HIF-1α increases radioresistance and chemoresistance by reducing DNA damage, increasing repair of DNA damage, enhancing glycolysis that increases antioxidant capacity of tumors cells, and promoting angiogenesis. In addition, HIF-1α markedly enhances drug efflux, leading to multidrug resistance. Radiotherapy and certain chemotherapy drugs evoke profound anti-tumor immunity by inducing immunologic cell death that release tumor-associated antigens together with numerous pro-immunological factors, leading to priming of cytotoxic CD8+ T cells and enhancing the cytotoxicity of macrophages and natural killer cells. Radiotherapy and chemotherapy of tumors significantly increase HIF-1α activity in tumor cells. Unfortunately, HIF-1α effectively promotes various immune suppressive pathways including secretion of immune suppressive cytokines, activation of myeloid-derived suppressor cells, activation of regulatory T cells, inhibition of T cells priming and activity, and upregulation of immune checkpoints. Consequently, the anti-tumor immunity elevated by radiotherapy and chemotherapy is counterbalanced or masked by the potent immune suppression promoted by HIF-1α. Effective inhibition of HIF-1α may significantly increase the efficacy of radiotherapy and chemotherapy by increasing radiosensitivity and chemosensitivity of tumor cells and also by upregulating anti-tumor immunity.
3.Higher Microbial Abundance and Diversity in Bronchus-Associated Lymphoid Tissue Lymphomas Than in Non-cancerous Lung Tissues
Jung Heon KIM ; Jae Sik KIM ; Noorie CHOI ; Jiwon KOH ; Yoon Kyung JEON ; Ji Hyun CHANG ; Eung Soo HWANG ; Il Han KIM
Cancer Research and Treatment 2025;57(2):580-589
Purpose:
It is well known that the majority of the extranodal marginal zone lymphomas of mucosa-associated lymphoid tissues (MALT lymphomas) are associated with microbiota, e.g., gastric MALT lymphoma with Helicobacter pylori. In general, they are very sensitive to low-dose radiotherapy and chemotherapeutic agents. The microbiota profile is not clearly elucidated in bronchus-associated lymphoid tissue (BALT) lymphoma, a rare type of MALT lymphoma in the lung. Thus, this study aimed to clarify the intratumor microbiome in BALT lymphoma using the third-generation next-generation sequencing (NGS) method.
Materials and Methods:
DNAs were extracted from 12 formalin-fixed paraffin-embedded (FFPE) tumor tissues obtained from BALT lymphoma patients diagnosed between 1990 and 2016. 16S rRNA gene was amplified by polymerase chain reaction. Amplicons were sequenced using a Nanopore platform. Next-generation sequencing analysis was performed to assess microbial profiles. For comparison, FFPE specimens from nine non-cancerous lung tissues were also analyzed.
Results:
Specific bacterial families including Burkholderiaceae, Bacillaceae, and Microbacteriaceae were associated with BALT lymphoma by a linear discriminant analysis effect size approach. Although the number of specimens was limited, BALT lymphomas exhibited significantly higher microbial abundance and diversity with distinct microbial composition patterns and correlation networks than non-cancerous lung tissues.
Conclusion
This study provides the first insight into intratumor microbiome in BALT lymphoma using the third-generation NGS method. A distinct microbial composition suggests the presence of a unique tumor microenvironment of BALT lymphoma.
4.Role of HIF-1α in the Responses of Tumors to Radiotherapy and Chemotherapy
Chang W SONG ; Hyunkyung KIM ; Mi-Sook KIM ; Heon J PARK ; Sun-Ha PAEK ; Stephanie TEREZAKIS ; L Chinsoo CHO
Cancer Research and Treatment 2025;57(1):1-10
Tumor microenvironment is intrinsically hypoxic with abundant hypoxia-inducible factors-1α (HIF-1α), a primary regulator of the cellular response to hypoxia and various stresses imposed on the tumor cells. HIF-1α increases radioresistance and chemoresistance by reducing DNA damage, increasing repair of DNA damage, enhancing glycolysis that increases antioxidant capacity of tumors cells, and promoting angiogenesis. In addition, HIF-1α markedly enhances drug efflux, leading to multidrug resistance. Radiotherapy and certain chemotherapy drugs evoke profound anti-tumor immunity by inducing immunologic cell death that release tumor-associated antigens together with numerous pro-immunological factors, leading to priming of cytotoxic CD8+ T cells and enhancing the cytotoxicity of macrophages and natural killer cells. Radiotherapy and chemotherapy of tumors significantly increase HIF-1α activity in tumor cells. Unfortunately, HIF-1α effectively promotes various immune suppressive pathways including secretion of immune suppressive cytokines, activation of myeloid-derived suppressor cells, activation of regulatory T cells, inhibition of T cells priming and activity, and upregulation of immune checkpoints. Consequently, the anti-tumor immunity elevated by radiotherapy and chemotherapy is counterbalanced or masked by the potent immune suppression promoted by HIF-1α. Effective inhibition of HIF-1α may significantly increase the efficacy of radiotherapy and chemotherapy by increasing radiosensitivity and chemosensitivity of tumor cells and also by upregulating anti-tumor immunity.
5.Higher Microbial Abundance and Diversity in Bronchus-Associated Lymphoid Tissue Lymphomas Than in Non-cancerous Lung Tissues
Jung Heon KIM ; Jae Sik KIM ; Noorie CHOI ; Jiwon KOH ; Yoon Kyung JEON ; Ji Hyun CHANG ; Eung Soo HWANG ; Il Han KIM
Cancer Research and Treatment 2025;57(2):580-589
Purpose:
It is well known that the majority of the extranodal marginal zone lymphomas of mucosa-associated lymphoid tissues (MALT lymphomas) are associated with microbiota, e.g., gastric MALT lymphoma with Helicobacter pylori. In general, they are very sensitive to low-dose radiotherapy and chemotherapeutic agents. The microbiota profile is not clearly elucidated in bronchus-associated lymphoid tissue (BALT) lymphoma, a rare type of MALT lymphoma in the lung. Thus, this study aimed to clarify the intratumor microbiome in BALT lymphoma using the third-generation next-generation sequencing (NGS) method.
Materials and Methods:
DNAs were extracted from 12 formalin-fixed paraffin-embedded (FFPE) tumor tissues obtained from BALT lymphoma patients diagnosed between 1990 and 2016. 16S rRNA gene was amplified by polymerase chain reaction. Amplicons were sequenced using a Nanopore platform. Next-generation sequencing analysis was performed to assess microbial profiles. For comparison, FFPE specimens from nine non-cancerous lung tissues were also analyzed.
Results:
Specific bacterial families including Burkholderiaceae, Bacillaceae, and Microbacteriaceae were associated with BALT lymphoma by a linear discriminant analysis effect size approach. Although the number of specimens was limited, BALT lymphomas exhibited significantly higher microbial abundance and diversity with distinct microbial composition patterns and correlation networks than non-cancerous lung tissues.
Conclusion
This study provides the first insight into intratumor microbiome in BALT lymphoma using the third-generation NGS method. A distinct microbial composition suggests the presence of a unique tumor microenvironment of BALT lymphoma.
6.Role of HIF-1α in the Responses of Tumors to Radiotherapy and Chemotherapy
Chang W SONG ; Hyunkyung KIM ; Mi-Sook KIM ; Heon J PARK ; Sun-Ha PAEK ; Stephanie TEREZAKIS ; L Chinsoo CHO
Cancer Research and Treatment 2025;57(1):1-10
Tumor microenvironment is intrinsically hypoxic with abundant hypoxia-inducible factors-1α (HIF-1α), a primary regulator of the cellular response to hypoxia and various stresses imposed on the tumor cells. HIF-1α increases radioresistance and chemoresistance by reducing DNA damage, increasing repair of DNA damage, enhancing glycolysis that increases antioxidant capacity of tumors cells, and promoting angiogenesis. In addition, HIF-1α markedly enhances drug efflux, leading to multidrug resistance. Radiotherapy and certain chemotherapy drugs evoke profound anti-tumor immunity by inducing immunologic cell death that release tumor-associated antigens together with numerous pro-immunological factors, leading to priming of cytotoxic CD8+ T cells and enhancing the cytotoxicity of macrophages and natural killer cells. Radiotherapy and chemotherapy of tumors significantly increase HIF-1α activity in tumor cells. Unfortunately, HIF-1α effectively promotes various immune suppressive pathways including secretion of immune suppressive cytokines, activation of myeloid-derived suppressor cells, activation of regulatory T cells, inhibition of T cells priming and activity, and upregulation of immune checkpoints. Consequently, the anti-tumor immunity elevated by radiotherapy and chemotherapy is counterbalanced or masked by the potent immune suppression promoted by HIF-1α. Effective inhibition of HIF-1α may significantly increase the efficacy of radiotherapy and chemotherapy by increasing radiosensitivity and chemosensitivity of tumor cells and also by upregulating anti-tumor immunity.
7.Dental Age Estimation in Children Using Convolution Neural Network Algorithm: A Pilot Study
Byung-Yoon ROH ; Hyun-Jeong PARK ; Kyung-Ryoul KIM ; In-Soo SEO ; Yeon-Ho OH ; Ju-Heon LEE ; Chang-Un CHOI ; Yo-Seob SEO ; Ji-Won RYU ; Jong-Mo AHN
Journal of Oral Medicine and Pain 2024;49(4):118-123
Purpose:
Recently, deep learning techniques have been introduced for age estimation, with automated methods based on radiographic analysis demonstrating high accuracy. In this study, we applied convolutional neural network (CNN) techniques to the lower dentition area on orthopantomograms (OPGs) of children to develop an automated age estimation model and evaluate its accuracy for use in forensic dentistry.
Methods:
In this study, OPGs of 2,856 subjects aged 3-14 years were analyzed. The You Only Look Once (YOLO) V8 object detection technique was applied to extract the mandibular dentition area on OPGs, designating it as the region of interest (ROI). First, 200 radiographs were randomly selected, and were used to train a model for extracting the ROI. The trained model was then applied to the entire dataset. For the CNN image classification task, 80% of OPGs were allocated to the training set, while the remaining 20% were used as the test set. A transfer learning approach was employed using the ResNet50 and VGG19 backbone models, with an ensemble technique combining these models to improve performance. The mean absolute error (MAE) on the test set was used as the validation metric, and the model with the lowest MAE was selected.
Results:
In this study, the age estimation model developed using mandibular dentition region from OPGs achieved MAE and root mean squared error (RMSE) values of 0.501 and 0.742, respectively, on the test set, and MAE and RMSE values of 0.273 and 0.354, respectively, on the training set.
Conclusions
The automated age estimation model developed in this study demonstrated accuracy comparable to that of previous research and shows potential for applications in forensic investigations. Increasing the sample size and incorporating diverse deep learning techniques are expected to further enhance the accuracy of future age estimation models.
8.Spinal Schwannoma Classification Based on the Presumed Origin With Preoperative Magnetic Resonance Images
Tae-Shin KIM ; Jae Hee KUH ; Junhoe KIM ; Woon Tak YUH ; Junghoon HAN ; Chang-Hyun LEE ; Chi Heon KIM ; Chun Kee CHUNG
Neurospine 2024;21(3):890-902
Objective:
Classification guides the surgical approach and predicts prognosis. However, existing classifications of spinal schwannomas often result in a high ‘unclassified’ rate. Here, we aim to develop a new comprehensive classification for spinal schwannomas based on their presumed origin. We compared the new classification with the existing classifications regarding the rate of ‘unclassified’. Finally, we assessed the surgical strategies, outcomes, and complications according to each type of the new classification.
Methods:
A new classification with 9 types was created by analyzing the anatomy of spinal nerves and the origin of significant tumor portions and cystic components in preoperative magnetic resonance images. A total of 482 patients with spinal schwannomas were analyzed to compare our new classification with the existing classifications. We defined ‘unclassified’ as the inability to classify a patient with spinal schwannoma using the classification criteria. Surgical approaches and outcomes were also aligned with our new classification.
Results:
Our classification uniquely reported no ‘unclassified’ cases, indicating full applicability. Also, the classification has demonstrated usefulness in predicting the surgical outcome with the approach planned. Gross total removal rates reached 88.0% overall, with type 1 and type 2 tumors at 95.3% and 96.0% respectively. The approach varied with tumor type, with laminectomy predominantly used for types 1, 2, and 9, and facetectomy with posterior fixation used for type 3 tumors.
Conclusion
The new classification for spinal schwannomas based on presumed origin is applicable to all spinal schwannomas. It could help plan a surgical approach and predict its outcome, compared with existing classifications.
9.Clinical Applications of Thermoplastic Sheets as Patient-Specific Gonadal Shields During Computed Tomography Simulation
Jin JEGAL ; Hyojun PARK ; Seonghee KANG ; Chang Heon CHOI ; Jung-in KIM
Progress in Medical Physics 2024;35(4):172-177
Purpose:
Conventional gonadal shields are manufactured in standardized sizes and shapes and do not conform to individual testicular contours, causing discomfort. We developed a novel patientspecific gonadal shield using thermoplastic sheets and tested its feasibility through dosimetric evaluations.
Methods:
During the computed tomography simulation, custom lead shields were fabricated using thermoplastic sheets that were molded to the testicular shape of the patient. The shielding efficacy was evaluated using optically stimulated luminescent dosimeters (OSLDs) for point dose measurements.
Results:
The thermoplastic sheet was molded to fit closely to the skin with a minimal air gap of approximately 8.4 cm³, providing comfort to the patient during treatment. The patient-specific shield effectively reduced the surface dose from 28 cGy to less than 15 cGy. By combining the OSLDs located in the same row and calculating the mean dose value, a shielding effect was achieved with a maximum dose reduction of 56.1%.
Conclusions
Customized gonadal shields were successfully created using thermoplastic sheets to minimize patient discomfort during application. However, further improvements in lead shield fabrication are needed to ensure full conformity.
10.Evaluation of the Dosimeter Volume Effect on Small-Field Dosimetry Using the Elekta Harmony Pro Linear Accelerator
Hyojun PARK ; Jin JEGAL ; Yoonsuk HUH ; Inbum LEE ; Sung Hyun LEE ; Chang Heon CHOI ; Jung-In KIM ; Seonghee KANG
Progress in Medical Physics 2024;35(4):89-97
Purpose:
This study investigated the dose perturbation according to the size of the sensitive volume in the dosimeter in small-field dosimetry.
Methods:
The dose profiles with different field sizes were measured using three different dosimeters: the CC13, Razor ion chamber, and Edge solid-state detector. Both the open and wedged beams with different field sizes were employed in the measurement. The profiles were measured in a water phantom at maximum dose depths of 5, 10, and 20 cm. The penumbra and width of the open-beam profiles were compared according to the types of the dosimeters and beam. The dose fall-off between the peak and 20% dose was evaluated for the wedged beam profiles.
Results:
In the open-beam measurement, the fall-off of the profile was steeper with the Edge detector, which has the smallest sensitive volume. Meanwhile, the dose in the out-of-field region was the smallest with the Edge detector. The widths of the penumbra were 6.10, 4.47, and 4.03 mm for the profile of the 3×3 cm 2 field measured by the CC13 chamber, Razor chamber, and Edge detector, respectively. The width of the profile was not changed even if different dosimeters were used in the measurement. The wedged beam profiles showed more clear peaks at the field edge when a smaller dosimeter was used.
Conclusions
The results demonstrate the necessity of dosimeters with a small sensitive volume for measuring a small-field beam or a steep dose gradient.

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