Less is more: level IB-sparing radiation therapy in nasopharyngeal cancer

Dongryul Oh(Dongryul Oh) 대한방사선종양학회 2023 Radiation Oncology Journal Vol.41 No.1

Insufficiency fracture after radiation therapy

Oh, Dongryul,Huh, Seung Jae The Korean Society for Radiation Oncology 2014 Radiation Oncology Journal Vol.32 No.4

Insufficiency fracture occurs when normal or physiological stress applied to weakened bone with demineralization and decreased elastic resistance. Recently, many studies reported the development of IF after radiation therapy (RT) in gynecological cancer, prostate cancer, anal cancer and rectal cancer. The RT-induced insufficiency fracture is a common complication during the follow-up using modern imaging studies. The clinical suspicion and knowledge the characteristic imaging patterns of insufficiency fracture is essential to differentiate it from metastatic bone lesions, because it sometimes cause severe pain, and it may be confused with bone metastasis.

Sorafenib-triggered radiation recall dermatitis with a disseminated exanthematous reaction

Dongryul Oh,Hee Chul Park,Ho Yeong Lim,Byung Chul Yoo 대한방사선종양학회 2013 Radiation Oncology Journal Vol.31 No.3

Sorafenib is a multi-targeted kinase inhibitor, which is the current standard treatment for advanced hepatocellular carcinoma (HCC). Only one case of radiation recall dermatitis (RRD) associated with sorafenib has been reported so far. Our patient with recurrent HCC was treated with palliative radiotherapy (RT) for the chest wall mass. Sorafenib at 400 mg twice daily was begun on the day following RT. On the 14th day post-RT, an erythematous patch was observed on right chest wall which matched area previously irradiated. It was consistent with RRD. Ten days later, a disseminated exanthematous rash and severe pruritus occurred. Sorafenib was stopped and an oral antihistamine was prescribed to relieve symptoms. At the 1-week follow-up after the cessation of sorafenib, all symptoms were resolved. Physicians should be alert to this recall phenomenon as it can occur both in the skin and elsewhere and the occurrence of RRD may be unpredictable.

Insufficiency fracture after radiation therapy

Dongryul Oh,MD,Seung Jae Huh,MD,PhD 대한방사선종양학회 2014 Radiation Oncology Journal Vol.32 No.4

Insufficiency fracture occurs when normal or physiological stress applied to weakened bone with demineralization and decreased elastic resistance. Recently, many studies reported the development of IF after radiation therapy (RT) in gynecological cancer, prostate cancer, anal cancer and rectal cancer. The RT-induced insufficiency fracture is a common complication during the follow-up using modern imaging studies. The clinical suspicion and knowledge the characteristic imaging patterns of insufficiency fracture is essential to differentiate it from metastatic bone lesions, because it sometimes cause severe pain, and it may be confused with bone metastasis.

Sorafenib-triggered radiation recall dermatitis with a disseminated exanthematous reaction

Oh, Dongryul,Park, Hee Chul,Lim, Ho Yeong,Yoo, Byung Chul The Korean Society for Radiation Oncology 2013 Radiation Oncology Journal Vol.31 No.3

Sorafenib is a multi-targeted kinase inhibitor, which is the current standard treatment for advanced hepatocellular carcinoma (HCC). Only one case of radiation recall dermatitis (RRD) associated with sorafenib has been reported so far. Our patient with recurrent HCC was treated with palliative radiotherapy (RT) for the chest wall mass. Sorafenib at 400 mg twice daily was begun on the day following RT. On the 14th day post-RT, an erythematous patch was observed on right chest wall which matched area previously irradiated. It was consistent with RRD. Ten days later, a disseminated exanthematous rash and severe pruritus occurred. Sorafenib was stopped and an oral antihistamine was prescribed to relieve symptoms. At the 1-week follow-up after the cessation of sorafenib, all symptoms were resolved. Physicians should be alert to this recall phenomenon as it can occur both in the skin and elsewhere and the occurrence of RRD may be unpredictable.

두경부암의 양성자치료 : 현재의 임상 적용 및 발전 방향

오동렬(Dongryul Oh) 대한두경부종양학회 2021 대한두경부 종양학회지 Vol.37 No.1

Intensity-modulated radiation therapy (IMRT) using X-rays is a standard technique implemented for treating head and n eck cancer (HNC). Compared to 3D conformal RT, IMRT can significantly reduce the radiation dose to surrounding normal tissues by using a highly conformal dose to the tumor. Proton therapy is a type of RT that uses positively charged particles named protons. Proton therapy has a unique energy deposit (i.e., Bragg peak) and greater biological effectiveness than that of therapy using X-rays. These inherent properties of proton therapy make the technique advantageous for HNC treatment. Recently, advanced techniques such as intensity-modulated proton therapy have further decreased the dose to normal organs with a higher conformal dose to the tumor. The usage of proton therapy for HNC is becoming widespread as the number of operational proton therapy centers has increased worldwide. This paper aims to present the current clinical evidence of proton therapy utility to HNC clinicians through a literature review. It also discusses the challenges associated with proton therapy and prospective development of the technique.

EEG를 이용한 긴장 · 이완지표에 관한 연구

오동률(Dongryul Oh),홍광석(Kwangsuk Hong) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.2

본 연구의 목적은 피험자에게 긴장을 사진으로 유발했을 때와 피험자 본인이 자각(自覺)하여 유발했을 때의 뇌파를 측정하여 어떤 것이 더 사람의 뇌파 변화에 영향을 끼치는지 비교하고 이를 수치화할 수 있는 지표를 제안하고자 함이다. 뇌파의 δ,θ, α, SMR-β, MID-β, HIGH-β, γ대역의 파워 값을 구하고 안정된 상태를 나타내는 α파와 긴장 상태를 나타내는 HIGH-β의 비율로 긴장·이완도를 수치화한 기존 이완지표인 HIGHβ(power비율) 를 이용해 긴장이 사진에 의해 유발되었을 때와 자각에 의해 유발 되었을 때 값을 수치화하여 비교한 결과, 사진을 이용하여 시각적으로 자극을 유발했을 때가 이완지표 수치가 낮은 것으로 확인되었다. 또한 피험자의 정신적 자각에 의해 유발된 이완상태를 기존 이완지표보다 잘 나타낼 수 있는 새로운 이완지표를 뇌파 대역별 상관관계를 바탕으로 제안하였고 실험을 통해 기존 이완지표와 새로운 이완지표를 비교하였다. The objective of this study is to present a relaxation indicator so that which factor affects change of human brain wave could be compared and digitized by measuring brain wave at the time when stressed and excited emotion is induced to test subject through a photo and such emotion is perceived by the test subject. As a result of comparing digitized power value at the time when stressed and excited emotion is induced to test subject through a photo and such emotion is perceived by the test subject by using α/high-β(power ratio) that is existing relaxation indicator after obtaining power value of δ, θ, α, SMR-β, MID-β, γ band of brain wave, it was confirmed that value of relaxation indicator when visual stimulation was induced by using a photo was low. In addition, a new relaxation indicator that may represent relaxation state of a emotion being induced by mental perception of the test subject better than existing relaxation indicator was suggested based on correlation by each brain wave band and through an experiment, existing relaxation indicator and a new relaxation indicator were compared.

Comparison of radiotherapy techniques in patients with thymic epithelial tumor who underwent postoperative radiotherapy

Hyunseok Lee(Hyunseok Lee),Dongryul Oh(Dongryul Oh),Yong Chan Ahn(Yong Chan Ahn),Hongryull Pyo(Hongryull Pyo),Kyungmi Yang(Kyungmi Yang),Jae Myoung Noh(Jae Myoung Noh) 대한방사선종양학회 2024 Radiation Oncology Journal Vol.42 No.1

Purpose: This retrospective study aimed to compare clinical outcomes and dosimetric parameters between radiation therapy (RT) techniques in patients with thymic epithelial tumor (TET). Materials and Methods: From January 2016 to December 2020, 101 patients with TET received adjuvant RT (median, 52.8 Gy; range, 48.4 to 66.0). Three different RT techniques were compared: three-dimensional conformal RT (3D-CRT; n = 59, 58.4%), intensity-modulated RT (IMRT; n = 23, 22.8%), and proton beam therapy (PBT; n = 19, 18.8%). Results: The median age of the patients and the follow-up period were 55 years (range, 28 to 79) and 43.4 months (range, 7.7 to 77.2). Patients in the PBT group were of the youngest age (mean age, 45.4 years), while those in IMRT group had the largest clinical target volume (mean volume, 149.6 mL). Patients in the PBT group had a lower mean lung dose (4.4 Gy vs. 7.6 Gy vs. 10.9 Gy, respectively; p < 0.001), lower mean heart dose (5.4 Gy vs. 10.0 Gy vs. 13.1 Gy, respectively; p = 0.003), and lower mean esophageal dose than patients in the 3D-CRT and IMRT groups (6.3 Gy vs. 9.8 Gy vs. 13.5 Gy, respectively; p = 0.011). Twenty patients (19.8%) showed disease recurrence, and seven patients (6.9%) died. The differences in the survival rates between RT groups were not statistically significant. Conclusion: In patients with TET who underwent adjuvant RT, PBT resulted in a lower dose of exposure to adjacent organs at risk. Survival outcomes for patients in PBT group were not significantly different from those in other groups.

Liquid biopsy using cfDNA to predict radiation therapy response in solid tumors

Won Kyung Cho(Won Kyung Cho),Junnam Lee(Junnam Lee),Sung-Min Youn(Sung-Min Youn),Dongryul Oh(Dongryul Oh),Do Hoon Lim(Do Hoon Lim),Han Gyul Yoon(Han Gyul Yoon),Eun-Hae Cho(Eun-Hae Cho),Jae Myoung Noh( 대한방사선종양학회 2023 Radiation Oncology Journal Vol.41 No.1

Purpose: This study explored the potential feasibility of cell-free DNA (cfDNA) in monitoring treatment response through the measurement of chromosomal instabilities using I-scores in the context of radiation therapy (RT) for other solid tumors. Materials and Methods: This study enrolled 23 patients treated with RT for lung, esophageal, and head and neck cancer. Serial cfDNA monitoring was performed before RT, 1 week after RT, and 1 month after RT. Low-depth whole-genome sequencing was done using Nano kit and NextSeq 500 (Illumina Inc.). To measure the extent of genome-wide copy number instability, I-score was calculated. Results: Pretreatment I-score was elevated to more than 5.09 in 17 patients (73.9%). There was a significant positive correlation between the gross tumor volume and the baseline I-score (Spearman rho = 0.419, p = 0.047). The median I-scores at baseline, post-RT 1 week (P1W), and post-RT 1 month (P1M) were 5.27, 5.13, and 4.79, respectively. The I-score at P1M was significantly lower than that at baseline (p = 0.002), while the difference between baseline and P1W was not significant (p = 0.244). Conclusion: We have shown the feasibility of cfDNA I-score to detect minimal residual disease after RT in patients with lung cancer, esophageal cancer, and head and neck cancer. Additional studies are ongoing to optimize the measurement and analysis of I-scores to predict the radiation response in cancer patients.

유틸리티 차량을 위한 연료전지 하이브리드 시스템 운전특성

이동율(Dongryul Lee),오성진(Sung-Jin Oh),정재화(Jaehwa Jeong),배중면(Joongmyeon Bae),이영기(Young-ki Lee) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Fel cell vehicles(FCV) will be one of alternative no-emission transportations. Batteries are usually hybridized with fuel cell to decrease electrical loads of fuel cell and take charge of randomly transient power. A DC/DC converter, 2㎾ PEMFC. and 24V batteries are included in 4㎾ FCV. Converter controls the power distribution ratio by mode change current defined in this study. The required power is divided by two control strategy modes. When the required power is lower than 2㎾e, fuel cell generates a proper power in power distribution mode 1. When the required power is higher than 2㎾e, batteries assist the insufficient fuel cell power in power distribution mode 2. This paper suggests some design issues for the stable operation of FCV.