Intensity-modulated radiotherapy for stage I glottic cancer: a short-term outcomes compared with three-dimensional conformal radiotherapy

Cho, Ick Joon,Chung, Woong-Ki,Lee, Joon Kyoo,Lee, Min-Cheol,Paek, Jayeong,Kim, Yong-Hyub,Jeong, Jae-Uk,Yoon, Mee Sun,Song, Ju-Young,Nam, Taek-Keun,Ahn, Sung-Ja,Lee, Dong Hoon,Yoon, Tae Mi,Lim, Sang-Ch The Korean Society for Radiation Oncology 2019 Radiation Oncology Journal Vol.37 No.4

Purpose: To investigate the differences in treatment outcomes between two radiation techniques, intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT). Materials and Methods: We retrospectively analyzed 160 (IMRT = 23, 3DCRT = 137) patients with stage I glottic cancer treated from January 2005 through December 2016. The IMRT was performed with TomoTherapy (16 patients), volumetric-modulated arc therapy (6 patients), and step-and-shoot technique (1 patient), respectively. The 3DCRT was performed with bilateral parallel opposing fields. The median follow-up duration was 30 months (range, 31 to 42 months) in the IMRT group and 65 months (range, 20 to 143 months) in the 3DCRT group. Results: The 5-year overall survival and 3-year local control rates of the 160 patients were 95.7% and 91.4%, respectively. There was no significant difference in 3-year local control rates between the IMRT and 3DCRT groups (94.4% vs. 91.0%; p = 0.587). Thirteen of 137 patients in the 3DCRT group had recurrences. In the IMRT group, one patient had a recurrence at the true vocal cord. Patients treated with IMRT had less grade 2 skin reaction than the 3DCRT group, but this had no statistical significance (4.3% vs. 21.2%; p = 0.080). Conclusion: IMRT had comparable outcomes with 3DCRT, and a trend of less acute skin reaction in stage I glottic cancer patients.

Analyzing the effect of liver-tumor motion on the dosimetric error in intensity-modulated radiation therapy using the Halcyon linear accelerator

Cho Shinhaeng,Cho Ick Joon,Kim Yong Hyub,Jeong Jea-Uk,Yoon Mee Sun,Nam Taek Keun,Ahn Sung Ja,Song Ju-Young 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.81 No.2

The Halcyon, closed-bore and O-ring type linear accelerator, is unable to use the specialized device which can reduce respiratory tumor-motion efect such as a gating system, and the internal target volume (ITV)-based IMRT method should be applied to the treatment of moving tumor target. In this study, the tumor-motion efect on the dosimetric accuracy of the ITV-based IMRT using the Halcyon. ITV-based volumetric modulated arc therapy (VMAT) plans using the Halcyon were prepared for ten cases of liver cancer while changing the number of arcs (1-arc, 3-arc, and 5-arc) in the plan. Delivery quality assurance (DQA) plans were created using the Delta4 Phantom+diode array to verify the dosimetric accuracy of the VMAT plans. DQA measurements were performed in both the static and the Hexa-Motion mode using the Delta4 HexaMotion system to evaluate the motion efect on the dosimetric accuracy. In the static mode, the average gamma pass rate (GPR) value was 99.98% for the 3%/3 mm criterion and 99.02% for the 2%/2 mm criterion, which can verify the sufcient dosimetric accuracy of the VMAT plans in this study. The average GPR values calculated with a 3%/3 mm criterion in the Hexa-Motion mode were 68.25%, 69.17%, and 75.52% for the 1-arc, 3-arc, and 5-arc VMAT plans, respectively. When the 2%/2 mm criterion was used, the average GPR values in the Hexa-Motion mode were 50.76%, 50.33%, and 56.21% for the 1-arc, 3-arc, and 5-arc VMAT plans. These signifcantly lower GPR values show that the dosimetric accuracy in the Halcyon is more afected by tumor motion compared to the conventional linear accelerator. This study verifes that it is advantageous to use a large number of arcs in the ITV-based VMAT plan implemented using the Halcyon to reduce dosimetric error due to tumor motion

Dosimetric analysis on the effect of tumor motion in IMRT for liver cancer: comparison of TomoTherapy and VMAT using the Delta4 Hexa-Motion system

Cho Shinhaeng,Cho Ick Joon,Kim Yong Hyub,Jeong Jae-Uk,Yoon Mee Sun,Ahn Sung-Ja,Nam Taek-Keun,Song Ju-Young 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.5

The internal target volume (ITV)-based IMRT method can be used to reduce the effect of respiratory tumor motion. In this study, the effect of tumor motion on the dosimetric accuracy during ITV-based IMRT was investigated. ITV-based IMRT plans for a total of ten cases of liver cancer were prepared in TomoTherapy (Tomo) and volumetric modulated arc therapy (VMAT). Delivery quality assurance (DQA) plans were created using Delta4 phantom for the verification of dosimetric accuracy of the established Tomo and VMAT plans. DQA measurements were performed in both the static mode and the Hexa-Motion mode by using the Delta4 Hexa-Motion system in Tomo and VMAT. In the static mode, the average gamma passing rate (GPR) using a 3% dose difference/3 mm distance-to-agreement criteria was 99.61% in Tomo and 99.35% in VMAT, which confirmed sufficient dosimetric accuracy in both IMRT methods. For the Hexa-Motion measurement, the average GRP result of 90.93% in Tomo was higher than the result of 82.58% obtained in VMAT. In addition, the difference in the GPR results between the static and the Hexa-motion modes in Tomo was 8.68%, which is approximately 8% less than the 16.77% difference in VMAT. This study verifies that the dosimetric error of ITV-based IMRT due to the tumor motion was larger in VMAT than in Tomo. Also, Tomo can be considered to be more suitable than the conventional LINAC-based VMAT method in terms of the dosimetric accuracy of ITV-based IMRT for the treatment of a moving tumor.

PIVKA-II as a surrogate marker for prognosis in patients with localized hepatocellular carcinoma receiving stereotactic body radiotherapy

Ick Joon Cho,Jae-Uk Jeong,Taek-Keun Nam,Young-Eun Joo,Sung-Bum Cho,Yong-Hyub Kim,Ju-Young Song,Mee Sun Yoon,Sung-Ja Ahn,Woong-Ki Chung 대한방사선종양학회 2022 Radiation Oncology Journal Vol.40 No.1

Purpose: This study aimed to determine the correlation between protein induced by vitamin K absence or antagonist-II (PIVKA-II) and stereotactic body radiotherapy (SBRT) in patients with hepatocellular carcinoma (HCC). Materials and Methods: Sixty-one patients received SBRT between 2015 and 2020 with a median dose of 48 Gy (range, 39 to 60 Gy) with a median of 4 fractions. Changes in tumor markers before and after SBRT were analyzed. Results: The median follow-up period was 31 months (range, 12 to 64 months). The estimated 2-year in-field failure-free survival, progression-free survival (PFS), and overall survival rates were 82.0%, 39.3%, and 96.7%, respectively. Patients with decreased PIVKA-II levels through SBRT had significantly few in-field failures (p = 0.005). Patients with PIVKA-II levels of ≤25 mAU/mL after SBRT had significantly long PFS (p = 0.004). Conclusion: PIVKA-II could be a useful surrogate marker for response or survival outcomes in patients with localized HCC receiving SBRT.

Intensity-modulated radiotherapy for stage I glottic cancer: a short-term outcomes compared with three-dimensional conformal radiotherapy

Ick Joon Cho,Woong-Ki Chung,Joon Kyoo Lee,Min-Cheol Lee,Jayeong Paek,Yong-Hyub Kim,Jae-Uk Jeong,Mee Sun Yoon,Ju-Young Song,Taek-Keun Nam,Sung-Ja Ahn,Dong Hoon Lee,Tae Mi Yoon,Sang-Chul Lim 대한방사선종양학회 2019 Radiation Oncology Journal Vol.37 No.4

Purpose: To investigate the differences in treatment outcomes between two radiation techniques, intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT). Materials and Methods: We retrospectively analyzed 160 (IMRT = 23, 3DCRT = 137) patients with stage I glottic cancer treated from January 2005 through December 2016. The IMRT was performed with TomoTherapy (16 patients), volumetric-modulated arc therapy (6 patients), and step-and-shoot technique (1 patient), respectively. The 3DCRT was performed with bilateral parallel opposing fields. The median follow-up duration was 30 months (range, 31 to 42 months) in the IMRT group and 65 months (range, 20 to 143 months) in the 3DCRT group. Results: The 5-year overall survival and 3-year local control rates of the 160 patients were 95.7% and 91.4%, respectively. There was no significant difference in 3-year local control rates between the IMRT and 3DCRT groups (94.4% vs. 91.0%; p = 0.587). Thirteen of 137 patients in the 3DCRT group had recurrences. In the IMRT group, one patient had a recurrence at the true vocal cord. Patients treated with IMRT had less grade 2 skin reaction than the 3DCRT group, but this had no statistical significance (4.3% vs. 21.2%; p = 0.080). Conclusion: IMRT had comparable outcomes with 3DCRT, and a trend of less acute skin reaction in stage I glottic cancer patients

산학정의 중편에 나타난 조선시대 영부족술에 대한 고찰

조진협,남영만,Cho, Jin Hyub,Nam, Young Man 영남수학회 2013 East Asian mathematical journal Vol.29 No.2

In this paper, we investigate the contents of Rule of Excess and Deficit in the second volume of San Hak Jeong Ui (Arithmetic Definition) compiled by Nam Byong Kil and corrcted by Lee Sang Hyok in the Choson Dynasty period.(Emperor Ko Jong, 1867).

산학정의 하편에 나타난 조선시대 다원술에 대하여

조진협,남영만,Cho, Jin-Hyub,Nam, Young-Man 영남수학회 2011 East Asian mathematical journal Vol.27 No.4

In this paper, we investigate the contents of Da-won-sul in the third volume of San Hak Jeong Ui (Arithmetic Definition) compiled by Nam Byong Kil and corrcted by Lee Sang Hyok in the Choson Dynasty period (Emperor Ko Jong 4, 1867).

Prognostic significance of lymphovascular invasion in patients with prostate cancer treated with postoperative radiotherapy

Jeong, Jae-Uk,Nam, Taek-Keun,Song, Ju-Young,Yoon, Mee Sun,Ahn, Sung-Ja,Chung, Woong-Ki,Cho, Ick Joon,Kim, Yong-Hyub,Cho, Shin Haeng,Jung, Seung Il,Kwon, Dong Deuk The Korean Society for Radiation Oncology 2019 Radiation Oncology Journal Vol.37 No.3

Purpose: To determine prognostic significance of lymphovascular invasion (LVI) in prostate cancer patients who underwent adjuvant or salvage postoperative radiotherapy (PORT) after radical prostatectomy (RP) Materials and Methods: A total of 168 patients with prostate cancer received PORT after RP, with a follow-up of ≥12 months. Biochemical failure after PORT was defined as prostate-specific antigen (PSA) ≥0.2 ng/mL after PORT or initiation of androgen deprivation therapy (ADT) for increasing PSA levels regardless of the value. We analyzed the clinical outcomes including survivals, failure patterns, and prognostic factors affecting the outcomes. Results: In total, 120 patients (71.4%) received salvage PORT after PSA levels were >0.2 ng/mL or owing to clinical failure. The 5-year biochemical failure-free survival (BCFFS), clinical failure-free survival (CFFS), distant metastasis-free survival (DMFS), overall survival, and cause-specific survival rates were 78.3%, 94.3%, 95.0%, 95.8%, and 97.3%, respectively, during a follow-up range of 12-157 months (median: 64 months) after PORT. On multivariate analysis, PSA level of ≤1.0 ng/mL at the time of receiving PORT predicted favorable BCFFS, CFFS, and DMFS. LVI predicted worse CFFS (p = 0.004) and DMFS (p = 0.015). Concurrent and/or adjuvant ADT resulted in favorable prognosis for BCFFS (p < 0.001) and CFFS (p = 0.017). Conclusion: For patients with adverse pathologic findings, PORT should be initiated as early as possible after continence recovery after RP. Even after administering PORT, LVI was an unfavorable predictive factor, and further intensive adjuvant therapy should be considered for these patients.

Prognostic significance of lymphovascular invasion in patients with prostate cancer treated with postoperative radiotherapy

Jae-Uk Jeong,Taek-Keun Nam,Ju-Young Song,Mee Sun Yoon,Sung-Ja Ahn,Woong-Ki Chung,Ick Joon Cho,Yong-Hyub Kim,Shin Haeng Cho,Seung Il Jung,Dong Deuk Kwon 대한방사선종양학회 2019 Radiation Oncology Journal Vol.37 No.3

Purpose: To determine prognostic significance of lymphovascular invasion (LVI) in prostate cancer patients who underwent adjuvant or salvage postoperative radiotherapy (PORT) after radical prostatectomy (RP) Materials and Methods: A total of 168 patients with prostate cancer received PORT after RP, with a follow-up of ≥12 months. Biochemical failure after PORT was defined as prostate-specific antigen (PSA) ≥0.2 ng/mL after PORT or initiation of androgen deprivation therapy (ADT) for increasing PSA levels regardless of the value. We analyzed the clinical outcomes including survivals, failure patterns, and prognostic factors affecting the outcomes. Results: In total, 120 patients (71.4%) received salvage PORT after PSA levels were >0.2 ng/mL or owing to clinical failure. The 5-year biochemical failure-free survival (BCFFS), clinical failure-free survival (CFFS), distant metastasis-free survival (DMFS), overall survival, and cause-specific survival rates were 78.3%, 94.3%, 95.0%, 95.8%, and 97.3%, respectively, during a follow-up range of 12–157 months (median: 64 months) after PORT. On multivariate analysis, PSA level of ≤1.0 ng/mL at the time of receiving PORT predicted favorable BCFFS, CFFS, and DMFS. LVI predicted worse CFFS (p = 0.004) and DMFS (p = 0.015). Concurrent and/or adjuvant ADT resulted in favorable prognosis for BCFFS (p < 0.001) and CFFS (p = 0.017). Conclusion: For patients with adverse pathologic findings, PORT should be initiated as early as possible after continence recovery after RP. Even after administering PORT, LVI was an unfavorable predictive factor, and further intensive adjuvanttherapy should be considered for these patients.

추진제 탱크 가압 시스템의 최적 구성

정영석(Young-Suk Jung),조남경(Nam-Kyung Cho),오승협(Seung-Hyub Oh) 한국항공우주연구원 2010 항공우주기술 Vol.9 No.1

발사체 추진기관은 추진제 탱크, 가압시스템, 추진제 충전/배출 시스템, 밸브 구동 시스템, 퍼지 시스템 등으로 구성되어 있다. 이 중에서 가압시스템은 온보드 실시간 제어 시스템을 포함하는 유일한 시스템으로 가장 중요한 서브시스템이다. 그러므로 추진제의 탑재량 선정 및 추진제 공급 시스템 개념설계 단계에서 가장 먼저 고려되어야 한다. 본 논문에서는 여러 타 발사체의 가압시스템에 대해 자료 조사를 수행하였고 국산화시 개발 가능한 구성을 정리하였으며, 최종적으로 시스템 중량 비교, 운용/안전/신뢰성/확장성 등을 비교 검토하여 최적 구성을 선정하였다. Propulsion system of launch vehicle is composed with subsystems as propellant tank, pressurization system, propellant fill/drain system, valve operating system, purge system and so on. Among others, pressurization system is the most important subsystem, because of the real-time control part for pressure control of propellant tank. Therefore, it is the subsystem that must be primarily considered on conceptual design process. In this paper, the data of the previously developed pressurization systems were collected and the optimum configuration was selected by analysis of advantage and disadvantage of the systems.