• Radiation Oncology Journal
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• 제32권1호
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• pp.23-30
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• 2014

Purpose: The goal of this study is to determine whether the magnitude of overlap between planning target volume (PTV) and rectum ($Rectum_{overlap}$) or PTV and bladder ($Bladder_{overlap}$) in prostate cancer volumetric-modulated arc therapy (VMAT) is predictive of the dose-volume relationships achieved after optimization, and to identify predictive equations and cutoff values using these overlap volumes beyond which the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) dose-volume constraints are unlikely to be met. Materials and Methods: Fifty-seven patients with prostate cancer underwent VMAT planning using identical optimization conditions and normalization. The PTV (for the 50.4 Gy primary plan and 30.6 Gy boost plan) included 5 to 10 mm margins around the prostate and seminal vesicles. Pearson correlations, linear regression analyses, and receiver operating characteristic (ROC) curves were used to correlate the percentage overlap with dose-volume parameters. Results: The percentage $Rectum_{overlap}$ and $Bladder_{overlap}$ correlated with sparing of that organ but minimally impacted other dose-volume parameters, predicted the primary plan rectum $V_{45}$ and bladder $V_{50}$ with $R^2$ = 0.78 and $R^2$ = 0.83, respectively, and predicted the boost plan rectum $V_{30}$ and bladder $V_{30}$ with $R^2$ = 0.53 and $R^2$ = 0.81, respectively. The optimal cutoff value of boost $Rectum_{overlap}$ to predict rectum $V_{75}$ >15% was 3.5% (sensitivity 100%, specificity 94%, p < 0.01), and the optimal cutoff value of boost $Bladder_{overlap}$ to predict bladder $V_{80}$ >10% was 5.0% (sensitivity 83%, specificity 100%, p < 0.01). Conclusion: The degree of overlap between PTV and bladder or rectum can be used to accurately guide physicians on the use of interventions to limit the extent of the overlap region prior to optimization.

• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.370-374
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• 2005

Objective: We investigated the morphologic changes within 24 hours after a single ${\gamma}$-irradiation in the rat brain. Methods: Forty Sprague-Dawley rats were used. After a burr hole trephination on right parietal area, cerebral hemisphere was irradiated with 2Gy and 5Gy using iridium-192($^{192}Ir$), respectively. The effect was assessed at 4, 8, 12 and 24 hours after irradiation. The histological changes were scored following the detection of edema or disarray severity. TUNEL-positive cells exhibiting apoptotic morphology were counted in irradiated region. Results: Cortical edema and disarray were initially showed at 4 or 8 hour and almost all defined at 24 hour after irradiation. And the injury was wedge shape. TUNEL-positive cells were minimal at 8 hour after irradiation as the number of positive cells were $2.6{\pm}5.27$(n=5) after 2Gy, and $0.8{\pm}0.84$(n=5) after 5Gy. But, the number of apoptotic cells were increased markedly to $60{\pm}6.24$ at 12 hour after 2Gy and to $104{\pm}19.7$ at 24 hour after 5Gy. Conclusion: There were prominent morphologic changes immediately after ${\gamma}$-irradiation. And, apoptosis was increased according to the time period. These findings implicate that brain irradiation induces rapid apoptotic change, which may play an important role in the pathogenesis of radiation-induced pathologic conditions.

• Journal of Trauma and Injury
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• 제36권3호
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• pp.265-268
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• 2023

Ankle fractures with syndesmotic injuries often require fixation, where metal screw fixation is a popular method. However, as the patient begins weight-bearing, most syndesmotic screws tend to loosen or break, and removal of such screws has been challenging for the surgeons, as the available techniques require predrilling or trephination and are associated with risks of bone damage. This study presents a case with technical tip for the removal of broken tricortical-fixed non-cannulated syndesmotic screws. It implements the generation of a small cortical window in the medial distal tibia and the use of pliers to engage the screw tip and remove through the medial side. The technique presented in the current study overcomes these limitations and facilitates minimal bone damage and reduced exposure to radiation.

• Journal of Korean Neurosurgical Society
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• 제64권6호
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• pp.983-994
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• 2021

Objective : The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). Methods : We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1-3 and 3-5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. Results : After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0-17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150-0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5-11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. Conclusion : The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

• 대한방사선치료학회지
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• 제34권
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• pp.43-50
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• 2022

목 적: 총 두피 방사선치료 시 정상 뇌 조직을 최대한 보호할 수 있도록 접선조사를 극대화하는 치료계획 및 장비를 선정하고자 하였다. 대상 및 방법: 인체 모형에 총 두피를 구획하여 치료 부위를 설정하고, 나선형 토모테라피(Helical TomoTherapy, HT) 계획, Complete Block을 이용한 나선형 토모테라피(Helical TomoTherapy with Complete Block, HTCB) 계획 그리고 체적조절호형방사선치료(Volumetric Modulated Arc Therapy, VMAT) 계획을 수립하였다. 모든 치료계획은 처방 선량(40 Gy)의 95%가 들어가는 치료계획 용적이 체적의 95% 이상이 될 수 있도록, Dmax가 처방 선량의 110%를 넘지 않게 하였다. 치료계획은 뇌를 포함한 손상 위험 장기의 선량 비교를 실시하였으며 뇌 선량의 경우 Emami 등의 연구 결과의 정상조직 평가기준 체적을 참고하여 뇌 조직의 선량을 평가하였다. 결 과: HT, HTCB, VMAT 각각 뇌 조직 선량 D_33%는 21.68 Gy, 13.75 Gy, 20.89 Gy, D_67%는 7.06 Gy, 3.21 Gy, 7.84 Gy, D100%는 3.14 Gy, 1.75 Gy, 3.84 Gy, D_mean은 16.64 Gy, 11.78 Gy, 16.64 Gy로 HTCB plan에서 전반적으로 선량이 낮았으며, 저선량은 5 Gy를 기준으로 체적을 구하였을 때 V_5Gy는 각각 87%, 49%, 96%로 나타났다. 이외의 시신경을 제외한 나머지(뇌줄기, 해마, 양측 안구)의 최대선량은 HTCB에서 가장 낮았다. 결 론: 토모테라피에서 Complete Block을 적용하였을 때 전체 뇌 조직의 선량 감소와 더불어 뇌에 포함된 양쪽 해마 등의 손상 위험 장기의 선량을 가장 최소화해 방사선 유도 뇌 손상의 발생과 그로 인한 신경인지 기능 감소 등에 대한 부작용의 확률을 줄일 수 있는 치료계획임을 확인하였다. 향후에는 총 두피 조사 이외에도 다양한 부위에 치료되는 고리 형태의 표적(Ring Target)에 대한 추가적인 연구를 진행하여 접선 조사에 대한 이점을 확립하게 된다면 치료계획 시 접선조사 극대화를 위해 Complete Block을 사용한 토모테라피를 적용함으로써 선량적으로 유용한 결과를 얻을 수 있을 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8483-8488
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• 2014

Background: Breast cancer is the most common cancer and the second most common cause of cancer-induced mortalities in Iranian women, following gastric carcinoma. The survival of these patients depends on several factors, which are very important to identify in order to understand the natural history of the disease. Materials and Methods: In this retrospective study, 313 consecutive women with pathologically-proven diagnosis of breast cancer who had been treated during a seven-year period (January 2006 until March 2014) at Towhid hospital, Sanandaj city, Kurdistan province of Iran, were recruited. The Kaplan-Meier method was used for data analysis, and finally those factors that showed significant association on univariate analysis were entered in a Cox regression model. Results: the mean age of patients was $46.10{\pm}10.81$ years. Based on Kaplan-Meier method median of survival time was 81 months and 5 year survival rate was $75%{\pm}0.43$. Tumor metastasis (HR=9.06, p=0.0001), relapse (HR=3.20, p=0.001), clinical stage of cancer (HR=2.30, p=0.03) and place of metastasis (p=0.0001) had significant associations with the survival rate variation. Patients with tumor metastasis had the lowest five-year survival rate (37%)and among them patients who had brain metastasis were in the worst condition (5 year survival rate= $11%{\pm}0.10$). Conclusions: Our findings support the observation that those women with higher stages of breast malignancies (especially with metastatic cancer) have less chance of surviving the disease. Furthermore, screening programs and early detection of breast cancer may help to increase the survival of those women who are at risk of breast cancer.

• 한국환경과학회지
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• 제15권12호
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• pp.1093-1101
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• 2006

In the present study we studied the growth, photosynthetic traits and protective mechanisms against oxidative stress in the primary loaves of cucumber (Cucumis sativus L.) seedlings with or without UV-B treatment. Cucumber seedings were irradiated with UV-B for 10 days in environment-controlled growth chambers. The primary leaves irradiated with UV-B showed reduction in leaf length and decreased biomass production. The reduced biomass production seemed to be due to a negative effect of UV-B radiation on the photosynthetic process. Changes in chemical properties of leaf, such as chi a/b ratio affected photosynthesis. UV-B significantly affected chl b content compared with chi a in the light harvesting complex resulting reduced photosynthetic activity Fv/Fm decreased with an UV-B stress, suggesting that the photosynthetic apparatus, and particularly, PS II was damaged under UV-B stress. Malondialdehyde(MDA) concentration which represents the state of membrane lipid peroxidation Increased significantly under UV-B stress confirming an oxidative stress. UV-B exposure with SA solution(0.1-1.0 mM) can partially ameliorated some of the detrimental effects of UV-B stress. Leaf injuries including loss of chlorophyll and decreased ratio of Fv/Fm were reduced with combined application of UV-B and SA. ABA and JA showed similar mode of action in physiological effects on photosynthetic activities though the levels were lower than those from SA treated plants. Chloroplast ultrastructure was also affected by UV-B exposure. The thickness of leaf tissue components decreased and the number of grana and thylakoids was reduced in chloroplast applied UV-B or SA alone. At combined stress granal and stromal thylakoids were less affected. The leaves under combined stress acquired a significant tolerance to oxidative stress. From these results, it can be suggested that SA may have involved a protective role against UV-B induced oxidative damage.

• Journal of Yeungnam Medical Science
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• 제6권2호
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• pp.103-111
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• 1989

방사선 조사후 방광의 손상에 관한 실험에서 다음과 같은 결과를 얻었다. 1. 손상군, 회복군 모두에서 암수가 비슷한 변화를 보여 방사선에 의한 손상에서 암수의 차이는 없었다. 2. 점막의 변화는 40GY 조사군에서 50GY군 보다 빨리 회복됨이 관찰되었고 14주에서 대부분 소실되었다. 3. 혈관의 변화는 40GY, 50GY 모두에서 혈관확장증, 초자질화, 내피하층과 중간층의 섬유화 등이 관찰되었으며 혈관주변의 섬유화는 15주까지 관찰되었다. 결체조직과 균육층의 변화는 40GY, 50GY 모두에서 조사후 15주까지 지속됨을 볼 수 있었다. 마우스의 평균수명(460일-1000일)에 비해 본 연구의 추적 기간이 105일로서 충분히 길다고는 할 수 없으나 상기 여러 결과로 미루어 후기 반응의 감소 및 예방을 위해 세심한 조사 계획이 있어야 함을 시사하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제12권1호
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• pp.3-16
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• 1989

In order to investigate the in vivo effect of $^{60}Co$ radiation on rabbit liver, the uptake ratio and regional excretory value in hepatocytes and Kupffer cells were estimated during acute and chronic hepatic injuries. The left lobe of liver was irradiated at 15 Gy or 30 Gy with a single dose and subsequent changes were analysed with a seial nuclear medicine imaging by using $^{99m}Tc-phytate,\;^{99m}Tc-DISIDA\;and\;^{99m}Tc-HSA$ and resulting data were computerized. The degree of hepatic damage, duration of the injury, and recovery pattern after the irradation were in agreement with the findings of other investigations. However, out values were more quantitative evacuation than those of other publications. Recovery of decreased uptake of $^{99m}Tc-phytate$ was delayed approximately $2{\sim}3$ days later than that of $^{99m}Tc-DISIDA$. In acute radiation induced injury, the results demonstrated that the recovery of Kupffer cells was delayed more than that of hepatocytes. This discrepancy was considered due to the differences in repair activities between these cell types. The decreased of regional excretory value in irradiated area was found to be dose-dependent but had no corelation with regional uptakes of DISIDA and phytate. The decreased of regional excretory value observed in non-irradiated region suggested that irradiated liver might induce an indirect effect.

• 대한정형외과 초음파학회지
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• 제7권1호
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• pp.49-66
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• 2014

지금까지 경추부 중재술은 방사선 투시하에 하는 것이 표준화된 방법이었다. 그러나 방사선을 피폭해야 하는 문제가 있으며, 실시간으로 조영제를 이용하여 투시하거나 컴퓨터단층촬영 유도하 시술로써 안전하게 시행하려는 노력에도 불구하고, 특히 경추간공 차단술에서, 예기치 않은 주사제의 동맥내 주입이 발생하여 심각한 합병증인 척수 손상, 소뇌 및 뇌간 경색 등의 증례들이 방사선 투시하 시술에서 보고되는 것이 사실이다. 최근에는 그 대안으로서 경추부 초음파 유도하 중재술이 시행되고 있는데, 초음파는 주요 신경 및 혈관 구조물들의 위치를 관찰하면서 목표 부위 주위로 주사제가 퍼져나가는 양상을 파악할 수 있다는 장점이 있기 때문이다. 또한 초음파는 방사선이 없고 간편하며 주사하는 동안 실시간으로 계속 영상을 제공함으로써 시술의 정확도를 높일 수 있는 술기이다. 결국 초음파 유도하 시술은 주요 신경과 혈관의 위치를 확인하면서 그에 대한 손상 혹은 주사를 피할 수 있기 때문에 이러한 구조물들의 손상 위험이 높은 경추부에서 안전하게 시행할 수 있다는 중요한 장점이 있는 술기이다. 그리하여 저자는 실시간 초음파 유도하라는 술기가 경추부 중재술에서 얼마나 유용한가에 대해 분석하여 기술하였다.