• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7371-7375
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• 2014

Background: Concurrent chemo-radiotherapy is the recommended standard treatment modality for patients with locally advanced lung cancer. The purpose of three-dimensional conformal radiotherapy (3DCRT) is to minimize normal tissue damage while a high dose can be delivered to the tumor. The most common dose limiting side effect of thoracic RT is radiation pneumonia (RP). In this study we evaluated the relationship between dose-volume histogram parameters and radiation pneumonitis. This study targeted prediction of the possible development of RP and evaluation of the relationship between dose-volume histogram (DVH) parameters and RP in patients undergoing 3DCRT. Materials and Methods: DVHs of 41 lung cancer patients treated with 3DCRT were evaluated with respect to the development of grade ${\geq}2$ RP by excluding gross tumor volume (GTV) and planned target volume (PTV) from total (TL) and ipsilateral (IPSI) lung volume. Results: Were admitted statistically significant for p<0.05. Conclusions: The cut-off values for V5, V13, V20, V30, V45 and the mean dose of TL-GTV; and V13, V20,V30 and the mean dose of TL-PTV were statistically significant for the development of Grade ${\geq}2$ RP. No statistically significant results related to the development of Grade ${\geq}2$ RP were observed for the ipsilateral lung and the evaluation of PTV volume. A controlled and careful evaluation of the dose-volume histograms is important to assess Grade ${\geq}2$ RP development of the lung cancer patients treated with concurrent chemo-radiotherapy. In the light of the obtained data it can be said that RP development may be avoided by the proper analysis of the dose volume histograms and the application of optimal treatment plans.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3619-3623
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• 2014

Background: The aim of the study was to evaluate the vaginal dose and toxicity in patients of cervical cancer treated with image guided brachytherapy at our institute. Materials and Methods: Thirty-five patients treated with image based brachytherapy for cervical cancer were included. Vaginal contouring was done on MRI at brachytherapy and with CT scans of subsequent brachytherapy fractions. Dose volume parameters (DVH) were reported in accordance with the GEC-ESTRO guidelines. These were correlated with vaginal toxicity (assessed by CTCAE version 3) and quality of sexual life assessed at one year of completion of treatment. Results: Vaginal shortness was observed in 22 out of 30 (62.8%) patients, Nine (25.7%) had vaginal dryness and in 10 (28.5%) patients, there was contact bleeding. No association could be demonstrated between the dose volume parameters and vaginal toxicity in the present study. Conclusions: The lack of association between dose volume parameters of vagina with vaginal morbidity may be due to uncertainties involved in the delineation of vaginal wall and dosimetry. Future research is required to accurately define vaginal dose distribution to study its correlation with vaginal morbidity. Vaginal morbidity needs to be documented in order to improve the sexual outcome in these patients.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4727-4732
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• 2014

Background: Breast cancers are becoming more frequently diagnosed at early stages with improved long term outcomes. Late normal tissue complications induced by radiotherapy must be avoided with new breast radiotherapy techniques being developed. The aim of the study was to compare dosimetric parameters of planning target volume (PTV) and organs at risk between conformal (CRT) and intensity-modulated radiation therapy (IMRT) after breast-conserving surgery. Materials and Methods: A total of 20 patients with early stage left breast cancer received adjuvant radiotherapy after conservative surgery, 10 by 3D-CRT and 10 by IMRT, with a dose of 50 Gy in 25 sessions. Plans were compared according to dose-volume histogram analyses in terms of PTV homogeneity and conformity indices as well as organs at risk dose and volume parameters. Results: The HI and CI of PTV showed no difference between 3D-CRT and IMRT, V95 gave 9.8% coverage for 3D-CRT versus 99% for IMRT, V107 volumes were recorded 11% and 1.3%, respectively. Tangential beam IMRT increased volume of ipsilateral lung V5 average of 90%, ipsilateral V20 lung volume was 13%, 19% with IMRT and 3D-CRT respectively. Patients treated with IMRT, heart volume encompassed by 60% isodose (30 Gy) reduced by average 42% (4% versus 7% with 3D-CRT), mean heart dose by average 35% (495cGy versus 1400 cGy with 3D-CRT). In IMRT minimal heart dose average is 356 cGy versus 90cGy in 3D-CRT. Conclusions: IMRT reduces irradiated volumes of heart and ipsilateral lung in high-dose areas but increases irradiated volumes in low-dose areas in breast cancer patients treated on the left side.

• 대한방사선기술학회지:방사선기술과학
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• 제46권3호
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• pp.239-246
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• 2023

In this study, we assessed the effect of reduction of tumor volume in the head and neck cancer by using RANDO phantom in Static Intensity-Modulated Radiation Therapy (S-IMRT) and Volumetric-Modulated Arc Therapy (VMAT) planning. RANDO phantom's body and protruding volumes were delineated by using Contour menu of Eclipse™ (Varian Medical System, Inc., Version 15.6, USA) treatment planning system. Inner margins of 2 mm to 10 mm from protruding volumes of the reference were applied to generate the parameters of reduced volume. In addition, target volume and Organ at Risk (OAR) volumes were delineated. S-IMRT plan and VMAT plan were designed in reference. These plans were assigned in the reduced volumes and dose was calculated in reduced volumes using preset Monitor unit (MU). Dose Volume Histogram (DVH) was generated to evaluate treatment planning. Conformity Index (CI) and R² in reference S-IMRT were 0.983 and 0.015, respectively. There was no significant relationship between CI and the reduced volume. Homogeneity Index (HI) and R² were 0.092 and 0.960, respectively. The HI increased when volume reduced. In reference VMAT, CI and R² were 0.992 and 0.259, respectively. There was no relationship between the volume reduction and CI. On the other hand, HI and R² were 0.078 and 0.895, respectively. The value of HI increased when the volume reduced. There was significant difference (p<0.05) between parameters (D_mean and D_max) of normal organs of S-IMRT and VMAT except brain stem. Volume reduction affected the CI, HI and OAR dose. In the future, additional studies are necessary to incorporate the reduction of the volume in the clinical setting.

• Journal of Korean Neurosurgical Society
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• 제47권2호
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• pp.128-133
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• 2010

Objective : The secondary verification of Leksell Gamma Knife treatment planning system (LGP) (which is the primary verification system) is extremely important in order to minimize the risk of treatment errors. Although prior methods have been developed to verify maximum dose and treatment time, none have studied maximum dose coordinates and treatment volume. Methods : We simulated the skull shape as an ellipsoid with its center at the junction between the mammillary bodies and the brain stem. The radiation depths of the beamlets emitted from 201 collimators were calculated based on the relationship between this ellipsoid and a single beamlet expressed as a straight line. A computer program was coded to execute the algorithm. A database system was adopted to log the doses for $31{\times}31{\times}31$ or 29,791 matrix points allowing for future queries to be made of the matrix of interest. Results : When we compared the parameters in seven patients, all parameters showed good correlation. The number of matrix points with a dose higher than 30% of the maximal dose was within ${\pm}\;2%$ of LGP. The 50% dose volume, which is generally the target volume, differs maximally by 4.2%. The difference of the maximal dose ranges from 0.7% to 7%. Conclusion : Based on the results, the variable ellipsoid modeling technique or variable ellipsoid modeling technique (VEMT) can be a useful and independent tool to verify the important parameters of LGP and make up for LGP.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.385.2-385.2
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• 2002

Cornus officinalis has been used as protective drug for liver and kidney function. In order to evaluate the effect on renal function of Corni Fructus. We measured urine volume, chemical parameters(urea nitrogen. creatinine, uric acid). electrolytes($Na^{+}$, $K^{+}$, $Cl^{-}$) in serum and urine. Furosemide showed significant urine volume. serum and urine parameters, but Corni Fructus showed normal level parameters by dose increasing in rats.

• Radiation Oncology Journal
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• 제27권4호
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• pp.240-248
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• 2009

목 적: 방사선치료 관련 연구를 수행함에 있어서 선량 체적 히스토그램(dose volume histogram, DVH)을 분석하는 것이 필수적이나 상용 방사선치료계획시스템에서 수행할 수 없다. 본 연구는 이러한 선량 체적 히스토그램의 정보를 쉽게 분석할 수 있도록 소프트웨어를 제작하였다. 대상 및 방법: 방사선치료계획 시스템에서 치료계획 후에 환자의 DVH 데이터를 텍스트로 저장하여 이를 이용해서 DVH 상에서의 필요한 특정 값들(Vx, Dx)을 지정하여 획득할 수 있도록 하였고, Niemierko의 generalized equivalent uniform dose (EUD), Lyman-Kutcher-Burman 모델을 이용한 normal tissue complication probability (NTCP) 및 방사선치료의 2차 암유발 위험도 인자인 organ equivalent dose (OED)를 계산하는 프로그램을 개발하였다. 결 과: 환자의 데이터를 가지고 실제 방사선치료계획 시스템 상에서의 Vx, Dx와 NTCP 비교를 통해 개발된 프로그램의 계산 알고리즘을 검증하였고 0.1% 내의 오차를 보였으며 EUD 및 OED도 성공적으로 계산되었다. 결 론: 선량 체적 히스토그램을 분석하는 프로그램을 개발하였으며 다양한 방사선치료 관련 연구에 활용할 수 있을 것으로 예상된다.

• Radiation Oncology Journal
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• 제36권3호
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• pp.227-234
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• 2018

Purpose: We compared how doses delivered via two-dimensional (2D) intracavitary brachytherapy (ICBT) and three-dimensional (3D) ICBT varied anatomically. Materials and Methods: A total of 50 patients who received 30 Gy of 3D ICBT after external radiotherapy (RT) were enrolled. We compared the doses of the actual 3D and 2D ICBT plans among patients grouped according to six anatomical variations: differences in a small-bowel V_2Gy, small bowel circumference, the direction of bladder distension, bladder volume, sigmoid V_3.5Gy, and sigmoid circumference. Seven dose parameters were measured in line with the EMBRACE recommendations. Results: In terms of bladder volume, the bladder and small-bowel D_2cc values were lower in the 150-250 mL bladder volume subgroup; and the rectum, sigmoid, and bladder D_2mL values were all lower in the >250 mL subgroup, for 3D vs. 2D ICBT. In the sigmoid V_3.5Gy >2 _mL subgroup, the sigmoid and bladder D_2mL values were significantly lower for 3D than 2D ICBT. The bladder D_2mL value was also significantly lower for 3D ICBT, as reflected by the sigmoid circumference. In patients with a small bowel V_2.0Gy >10 mL or small bowel circumference >15%, most dose parameters were significantly lower for 3D than 2D ICBT. The bladder distension direction did not significantly affect the doses. Conclusion: Compared to 2D ICBT, a greater bladder volume can reduce the internal 3D ICBT organ dose without affecting the target dose.

• Radiation Oncology Journal
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• 제31권4호
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• pp.234-238
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• 2013

Purpose: Esophageal tolerance is needed to guide the safe administration of stereotactic radiosurgery (SRS). We evaluated comprehensive dose-volume parameters of acute esophageal toxicity in patients with spinal metastasis treated with SRS. Materials and Methods: From May 2008 to May 2011, 30 cases in 27 patients with spinal metastasis received single fraction SRS to targets neighboring esophagus. Endpoints evaluated include length (mm), volume (mL), maximal dose (Gy), and series of dose-volume thresholds from the dose-volume histogram (volume of the organ treated beyond a threshold dose). Results: The median time from the start of irradiation to development of esophageal toxicity was 2 weeks (range, 1 to 12 weeks). Six events of grade 1 esophageal toxicity occurred. No grade 2 or higher events were observed. $V_{15}$ of external surface of esophagus was found to predict acute esophageal toxicity revealed by multivariate analysis (odds radio = 1.272, p = 0.047). Conclusion: In patients with spinal metastasis who received SRS for palliation of symptoms, the threshold dose-volume parameter associated with acute esophageal toxicity was found to be $V_{15}$ of external surface of esophagus. Restrict $V_{15}$ to external surface of esophagus as low as possible might be safe and feasible in radiosurgery.

• Radiation Oncology Journal
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• 제38권1호
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• pp.60-67
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• 2020

Purpose: We performed three-dimensional (3D) dose reconstruction-based pretreatment verification to evaluate gamma analysis acceptance criteria in volumetric modulated arc therapy (VMAT) for prostate cancer. Materials and Methods: Pretreatment verification for 28 VMAT plans for prostate cancer was performed using the COMPASS system with a dolphin detector. The 3D reconstructed dose distribution of the treatment planning system calculation (TC) was compared with that of COMPASS independent calculation (CC) and COMPASS reconstruction from the dolphin detector measurement (CR). Gamma results (gamma failure rate and average gamma value [GFR and γAvg]) and dose-volume histogram (DVH) deviations, 98%, 2% and mean dose-volume difference (DD_98%, DD_2% and DD_mean), were evaluated. Gamma analyses were performed with two acceptance criteria, 2%/2 mm and 3%/3 mm. Results: The GFR in 2%/2 mm criteria were less than 8%, and those in 3%/3 mm criteria were less than 1% for all structures in comparisons between TC, CC, and CR. In the comparison between TC and CR, GFR and γAvg in 2%/2 mm criteria were significantly higher than those in 3%/3 mm criteria. The DVH deviations were within 2%, except for DD_mean (%) for rectum and bladder. Conclusions: The 3%/3 mm criteria were not strict enough to identify any discrepancies between planned and measured doses, and DVH deviations were less than 2% in most parameters. Therefore, gamma criteria of 2%/2 mm and DVH related parameters could be a useful tool for pretreatment verification for VMAT in prostate cancer.