Co-authorship patterns and networks of Korean radiation oncologists

Choi, Jin-Hyun,Kang, Jin-Oh,Park, Seo-Hyun,Kim, Sang-Ki The Korean Society for Radiation Oncology 2011 대한방사선종양학회지 Vol.29 No.3

Purpose: This research aimed to analyze the patterns of co-authorship network among the Korean radiation oncologists and to identify attributing factors for the formation of networks. Materials and Methods: A total of 1,447 articles including contents of ‘Radiation Oncology' and 'Therapeutic Radiology' were searched from the KoreaMed database. The co-authorship was assorted by the author's full name, affiliation and specialties. UCINET 6.0 was used to fi gure out the author's network centrality and the cluster analysis, and KeyPlayer 1.44 program was used to get a result of key player index. Sociogram was analyzed with the Netdraw 2.090. The statistical comparison was performed by a t-test and ANOVA using SPSS 16.0 with p-value < 0.05 as the significant value. Results: The number of articles written by a radiation oncologist as the first author was 1,025 out of 1,447. The pattern of coauthorship was classified into five groups. For articles of which the first author was a radiation oncologist, the number of singleauthor articles (type-A) was 81; single-institution articles (type-B) was 687; and multiple-author articles (type-C) was 257. For the articles which radiation oncologists participated in as a co-author, the number of single-institution articles (type-D) was 280 while multiple-institution articles (type-E) were 142. There were 8,895 authors from 1,366 co-authored articles, thus the average number of authors per article was 6.51. It was 5.73 for type-B, 6.44 for type-C, 7.90 for type-D, and 7.67 for type-E (p = 0.000) in the average number of authors per article. The number of authors for articles from the hospitals published more than 100 articles was 7.23 while form others was 5.94 (p = 0.005). Its number was 5.94 and 7.16 for the articles published before and after 2001 (p = 0.000). The articles written by a radiation oncologist as the first author had 5.92 authors while others for 7.82 (p = 0.025). Its number was 5.57 and 7.71 for the Journal of the Korean Society for Therapeutic Radiology and Oncology and others (p = 0.000), respectively. Among the analysis, a significant difference in the average number of author per article was indicated. The out-degree centrality of network among authors was 4.26% (2.03-7.09%) while in-degree centrality was 1.31% (0.53-2.84%). The three significant nodes were classified and listed as following: Choi, Eun Kyung for 1991-1995, Kim, Dae Young for 1998-2001, Park, Won and Lee, Sang Wook for 2003-2010. Choi, Eun Kyung and Kim, Dae Young appeared in two cases, and ranked as the highest degree in centrality. In the key player analysis, Choi, Eun Kyung and Lee, Sang Wook appeared in two cases, and ranked as the highest. From the cluster analysis, Sungkyunkwan University, Seoul National University and Yonsei University revealed as the three large clusters when Ulsan University, Chonnam National University, and Korea Institute of Radiological & Medical Science as the medium clusters. Conclusion: The Korean radiation oncologist's society shows a closed network with numerous relationships among the particular clusters, and the result indicates it is different from other institutions in the pattern of co-authorship formation of the major hospitals.

Development of new on-line statistical program for the Korean Society for Radiation Oncology

Song, Si Yeol,Ahn, Seung Do,Chung, Weon Kuu,Shin, Kyung Hwan,Choi, Eun Kyung,Cho, Kwan Ho The Korean Society for Radiation Oncology 2015 대한방사선종양학회지 Vol.33 No.2

Purpose: To develop new on-line statistical program for the Korean Society for Radiation Oncology (KOSRO) to collect and extract medical data in radiation oncology more efficiently. Materials and Methods: The statistical program is a web-based program. The directory was placed in a sub-folder of the homepage of KOSRO and its web address is http://www.kosro.or.kr/asda. The operating systems server is Linux and the webserver is the Apache HTTP server. For database (DB) server, MySQL is adopted and dedicated scripting language is the PHP. Each ID and password are controlled independently and all screen pages for data input or analysis are made to be friendly to users. Scroll-down menu is actively used for the convenience of user and the consistence of data analysis. Results: Year of data is one of top categories and main topics include human resource, equipment, clinical statistics, specialized treatment and research achievement. Each topic or category has several subcategorized topics. Real-time on-line report of analysis is produced immediately after entering each data and the administrator is able to monitor status of data input of each hospital. Backup of data as spread sheets can be accessed by the administrator and be used for academic works by any members of the KOSRO. Conclusion: The new on-line statistical program was developed to collect data from nationwide departments of radiation oncology. Intuitive screen and consistent input structure are expected to promote entering data of member hospitals and annual statistics should be a cornerstone of advance in radiation oncology.

Treatment of Ednometrial Carcinoma Stage II

Han I.,Kanellitsas C.,Kumar N.,Amendola B.,Morley G. The Korean Society for Radiation Oncology 1984 Radiation Oncology Journal Vol.2 No.2

Between January 1971 and December 1580 fifteen patients diagnosed of adenocarcinoma of the endometrium, stage II seen and treated at the University of Michigan Hospitals. are reviewed. Ten patients were treated with radiation therapy alone. five received hysterectomy after radiation. The five year survival of the patients receiving radiation and surgery was $100\%$ although one of them died after 62 month aster treatment. Of those receiving radiotherapy alone two died at i and 24months after therapy. All of the patients died of distant metastasis. Radiation cystitis was observed among surgically treated patients. while proctitis was observed in 3 cases receiving radiation alone. Though the number of cases reported is small due to rarity of the disease. it appears that radiation alone could provide reasonable tumor control. Also it appears that preoperative irradiation might lead to a longer survival. One patient who survived 62 months had para-aortic node involvement.

Radiation-induced brain injury: retrospective analysis of twelve pathologically proven cases

Lee, Dong-Soo,Yu, Mi-Na,Jang, Hong-Seok,Kim, Yeon-Sil,Choi, Byung-Ock,Kang, Young-Nam,Lee, Youn-Soo,Kim, Dong-Chul,Hong, Yong-Kil,Jeun, Sin-Soo,Yoon, Sei-Chul The Korean Society for Radiation Oncology 2011 대한방사선종양학회지 Vol.29 No.3

Purpose: This study was designed to determine the influencing factors and clinical course of pathologically proven cases of radiation-induced brain injury (RIBI). Materials and Methods: The pathologic records of twelve patients were reviewed; these patients underwent surgery following radiotherapy due to disease progression found by follow-up imaging. However, they were finally diagnosed with RIBI. All patients had been treated with 3-dimensional conventional fractionated radiotherapy and/or radiosurgery for primary or metastatic brain tumors with or without chemotherapy. The histological distribution was as follows: two falx meningioma, six glioblastoma multiform (GBM), two anaplastic oligodendroglioma, one low grade oligodendroglioma, and one small cell lung cancer with brain metastasis. Results: Radiation necrosis was noted in eight patients and the remaining four were diagnosed with radiation change. Gender (p = 0.061) and biologically equivalent dose $(BED)_3$ (p = 0.084) were the only marginally influencing factors of radiation necrosis. Median time to RIBI was 7.3 months (range, 0.5 to 61 months). Three prolonged survivors with GBM were observed. In the subgroup analysis of high grade gliomas, RIBI that developed <6 months after radiotherapy was associated with inferior overall survival rates compared to cases of RIBI that occurred ${\geq}6$ months (p = 0.085). Conclusion: Our study demonstrated that RIBI could occur in early periods after conventional fractionated brain radiotherapy within normal tolerable dose ranges. Studies with a larger number of patients are required to identify the strong influencing factors for RIBI development.

새로운 전중추신경 방사선 조사법 ; 방사선속의 발산에 의한 선량의 불균일성을 극복하기 위한 치료 방법

장혜숙,Chang, Hye-Sook The Korean Society for Radiation Oncology 1991 Radiation Oncology Journal Vol.9 No.2

전중추신경 방사선 조사는 수아세포종, 중추신경정상피종, 중추신경임파종, 중추신경백혈병 환자 치료에 시행한다. 뇌부위에는 양면 조사야를 통하고 척추 신경부위는 후면 단일 조사야를 통해 방사선 조사한다. 이때 조사야가 인접한 부위에서 발생하는 방사선조사야의 중첩에 의한 선량의 불균일성은 큰 문제로, 특히 척추신경의 극히 한정된 방사선 인내능력으로 인해 심각한 부작용을 병발할 수 있다. 이 문제를 해결하기위한 많은 연구가 보고되고 있으나 그들이 보고한 방법에 의해서도 불균일성은 최고 $60\%\sim70\%$로 부터 최소 $15\%\sim20\%$에 이른다. 저자는 split beam (central axis beam)과 collimator rotation technique을 이용하거나 collimator/couch rotation technique을 이용하여 3조사야가 접하는 부위의 방사선량의 불균일성을 해결하고자 시도하였다. 저자의 방법으로 시행할 때 3조사야가 접하는 부위에서의 불균일성은 $5\%$정도로 감소시킬 수 있었다. 본 논문에서 저자의 방법의 장단점을 기술하였다. To irradiate the entire neuroaxis, bilateral parallel opposed brain fields and direct posterior spinal field have been utilized and radiation dose at the junction between abutting fields has been extensilvely studied. And several workable methods were reported to achieve uniform dose at a desired depth at the juction between abutting fields whose central axis are coplanar. But the dose distribhution at the juction of orthogonal fields has been a persistent problem in radiation oncology. Author describes a new method to solve the junction problem between abutting fields whose central axis are orthogonal. Author utilized split beam/comllimator rotation or collimator/couch rotation to avoid hot or cold spots that may arise from beam divergence. Author achieved accurate and homogeneous dose distribution by mathching the $50\%$ isodose line at the junction between orthogonal central axis beam fields.

CT-based quantitative evaluation of radiation-induced lung fibrosis: a study of interobserver and intraobserver variations

Heo, Jaesung,Cho, Oyeon,Noh, O Kyu,O, Young-Taek,Chun, Mison,Kim, Mi-Hwa,Park, Hae-Jin The Korean Society for Radiation Oncology 2014 대한방사선종양학회지 Vol.32 No.1

Purpose: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intra-class correlation coefficient (ICC). Results: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.

The safety and efficacy of EGF-based cream for the prevention of radiotherapy-induced skin injury: results from a multicenter observational study

Kang, Hyun-Cheol,Ahn, Seung-Do,Choi, Doo-Ho,Kang, Min Kyu,Chung, Woong-Ki,Wu, Hong-Gyun The Korean Society for Radiation Oncology 2014 대한방사선종양학회지 Vol.32 No.3

Purpose: This study was designed to evaluate the efficacy and safety of topically applied recombinant human epidermal growth factor (rhEGF) for the prevention of radiation-induced dermatitis in cancer patients. Materials and Methods: From December 2010 to April 2012, a total of 1,172 cancer patients who received radiotherapy (RT) of more than 50 Gy were prospectively enrolled and treated with EGF-based cream. An acute skin reaction classified according to the Radiation Therapy Oncology Group 6-point rating scale was the primary end point and we also assessed the occurrence of edema, dry skin, or pruritus. Results: The percentage of radiation dermatitis with maximum grade 0 and grade 1 was 19% and 58% at the time of 50 Gy, and it became 29% and 47% after completion of planned RT. This increment was observed only in breast cancer patients (from 18%/62% to 32%/49%). Adverse events related to the EGF-based cream developed in 49 patients (4%) with mild erythema the most common. Skin toxicity grade >2 was observed in 5% of the patients. Edema, dry skin, and pruritus grade ${\geq}3$ developed in 9%, 9%, and 1% of the patients, respectively. Conclusion: Prophylactic use of an EGF-based cream is effective in preventing radiation dermatitis with tolerable toxicity. Further studies comparing EGF cream with other topical agents may be necessary.

Enhancement of in vivo Radiosensitization by Combination with Pentoxifylline and Nicotinamide

이인태,조문준,Lee Intae,Cho Moon-June The Korean Society for Radiation Oncology 1991 Radiation Oncology Journal Vol.9 No.2

Pentoxifylline (PENTO)는 적혈구의 유동성을 증가시켜 모세혈관의 적혈구 흐름을 증가시킨다. 또한 적혈구내 2,3-DPG를 증가시켜서 산소 친화력을 감소시켜 산소의 해리를 촉진시킨다. Nicotinamide (NA)는 종양내 혈류를 일시적으로 증가시켜서 종양내 급성 저산소 세포의 수를 감소시킨다. PENTO와 NA의 병용이 저산소 세포의 산소화에 의해서 방사선 감수성을 증가시킬 수 있는지를 확인하기 위하여 FSaII생쥐의 섬유육종을 이용하여 실험을 시행하였다. 방사선에 의한 성장 장애가 유의하게 증가하였으며, 증가율은 2.5~2.8이었다. $TCD_{50}$가 대조 종양군에서는 57Gy였으나 PENTO+NA투여 종양군에서는 32Gy로 1.8배의 $TCD_{50}$의 감소를 보였다. 정상피부의 방사선 감수성에는 영향이 없었다. PENTO+NA의 방사선 감수성의 증가를 규명하기 위하여 종양내 혈류의 변화, 종양내 산소농도를 laser Doppler flowmetry와 산소 미소전극 방법으로 측정하였다. PENTO+NA투여후 10분 경과하여 혈류가 유의하게 증가하였으며 종양내 산소 분압도 8 mmHg에서 19 mmHg로 유의하게 증가함을 관찰하였다. 따라서 PEHTO또는 NA단독보다 PENTO+NA병통이 더욱 효과적이라 사료되며 생체내 종양의 방사선 감수성의 증가는 종양내 산소의 증가로 생각되며 더욱 방사선 감수성을 증가시키기 위하여 여러 농도의 PENTO의 단독 또는 NA와의 병용등에 대한 지속적인 연구가 필요하다. Pentoxifylline (PENTO) has been known to improve RBC fluidity, and thus improve the flux of RBC through narrow capillaries. Additionally, PENTO also decreases the $O_2$ affinity of hemoglobin by increasing 2,3-DPG levels, thereby increasing the $O_2$ release from RBC. Nicotinamide (NA) has been reported to decrease the number of acutely hypoxic cells in tumors by temporarily increasing tumor blood flow. Therefore, the purpose of this study was to examine whether the combination of PENTO and NA (PENTO+NA) would reduce the radioresistance of the Fsall murine fibrosarcoma by oxygenating the hypoxic cells. We obsewed a significantly enhanced radiation-induced growth delay of the FSaII tumors by PENTO+NA. Thus the enhancement ratio was between 2.5 and 2.8 in growth delay assay. The $TCD_{50}$ of control tumors was about 57 Gy, but that of PENTO+NA treated tumors was about 32Gy. Thus $TCD_{50}$ was modified by a factor of 1.8. We also observed that PENTO+NA exerted no effect on the radiation-induced skin damage after the legs without bearing tumors were exposed to X-irradiation. In order to clarify radiosensitizing effects of PENTO+ NA, changes in tumor blood flow and intratumor pOf were measured using laser Doppler flowmetry and $O_2$ microelectrode methods. The tumor blood flow significantly increased at 10 min. after injection of PENTO+ NA. Furthermore, we also found that PENTO+ NA significantly increased intratumor $pO_2$ from 8 to 19 mmHg. We concluded that PENTO+MA was far more effective than NA alone or PENTO alone. The increase in the response of tumors in vivo to X-irradiation appeared to be due mainly to an increase in the tumor oxygenation. Further studies using various concentrations of PENTO alone and in combination with NA to obtain better sequencing and maximal radiosensitization are warranted.

Mechanisms of radiation-induced normal tissue toxicity and implications for future clinical trials

Kim, Jae Ho,Jenrow, Kenneth A.,Brown, Stephen L. The Korean Society for Radiation Oncology 2014 대한방사선종양학회지 Vol.32 No.3

To summarize current knowledge regarding mechanisms of radiation-induced normal tissue injury and medical countermeasures available to reduce its severity. Advances in radiation delivery using megavoltage and intensity-modulated radiation therapy have permitted delivery of higher doses of radiation to well-defined tumor target tissues. Injury to critical normal tissues and organs, however, poses substantial risks in the curative treatment of cancers, especially when radiation is administered in combination with chemotherapy. The principal pathogenesis is initiated by depletion of tissue stem cells and progenitor cells and damage to vascular endothelial microvessels. Emerging concepts of radiation-induced normal tissue toxicity suggest that the recovery and repopulation of stromal stem cells remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after radiation exposure. Better understanding the mechanisms mediating interactions among excessive generation of reactive oxygen species, production of pro-inflammatory cytokines and activated macrophages, and role of bone marrow-derived progenitor and stem cells may provide novel insight on the pathogenesis of radiation-induced injury of tissues. Further understanding the molecular signaling pathways of cytokines and chemokines would reveal novel targets for protecting or mitigating radiation injury of tissues and organs.

Effect of lonizing Radiation on the Host Resistance Against Listeria Monocytogenes Infection and the Cytokine Production in Mice

오윤경,장미영,강인철,오종석,이현철,Oh, Yoon-Kyeong,Chang, Mee-Young,Kang, In-Chol,Oh, Jong-Suk,Lee, Hyun-Chul The Korean Society for Radiation Oncology 1997 대한방사선종양학회지 Vol.15 No.3

Purpose : To evaluate the qualitative immunologic changes by ionizing radiation. we studied the altered capacities of the macrophages and lymphocytes to produce cytokines in conjunction with resistance to Listeria monocytegenes (LM) infection in mice Materials and Methods : BALB/c mice and Listeria monocytogenes were used. The mice were infected intraperitoneally with $10^5LM$ at 1 day after irradiation (300cGy) and sacrificed at 1, 3, 5 days after infection, and then the numbers of viable LM per spleen in the irradiated and control group were counted. Tumor necrosis factor-alpha ($TNF-\alpha$), interferon-gamma ($IFN-\gamma$). interleukin-2 (IL-2), and nitric oxide (NO) were assessed after irradiation. Results : Under gamma-ray irradiation with a dose range of 100-850cGy, the number of total splenocytes decreased markedly in a dose-dependent manner, while peritoneal macrophages did so slightly Cultured peritoneal macrophages produced more $TNF-\alpha$ in the presence of lipopolysaccharide (LPS) during the 24 hours after in vitro irradiation, but their capacity of $TNF-\alpha$ Production showed a decreased tendency at 5 days after in vivo total body irradiation. With 100cGy and 300cGy irradiation, cultured peritoneal macrophages produced more NO in the presence of LPS during the 24 hours after in vitro irradiation than without irradiation. Activated splenocytes from irradiated mice (300cGy) exhibited a decreased capacity to Produce IL-2 and $IFN-\gamma$ with Concavalin-A stimulation at 3 days after irradiation. When BALB/c mice were irradiated to the total body with a dose of 300cGy, they showed enhanced resistance during early innate phase, but a significant inhibition of resistance to LM was found in the late innate and acquired T-cell dependent phases. Conclusion : These results su99es1 that increased early innate and decreased late innate and acquired immunity to LM infection by ionizing radiation (300cGy) may be related to the biphasic altered capacity of the macrophages to produce $TNF-\alpha$ and the decreased capacities of the lymphocytes to produce IL-2 and $IFN-\gamma$ in addition to a marked decrease in the total number of cells.