• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.129-138
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• 2018

Purpose : An aim of this study was to compare the effect of multi leaf collimator(MLC) types for high dimension radiotherapy in treatment sites used clinically. Material and Method : 70 patients with lung cancer, spine cancer, prostate cancer, whole pelvis, head and neck, breast cancer were included in this study. High definition(HD) MLC of TrueBeam STx (Varian Medical system, Palo Alto, CA) and millenium(M) MLC of VitalBeam (Varian Medical system, Palo Alto, CA) were used. Radiotherapy plans were performed for each patient under same treatment goals with Eclipse (Version 13.7, Varian Palo Alto USA, CA). To compare the indicators of the radiotherapy plans, planning target volume(PTV) coverage, conformity index(CI), homogeneity index(HI), and clinical indicators for each treatment sites in normal tissues were evaluated. To evaluate low dose distribution, $V_{30%}$ values were compared according to MLC types. Additionally, length and volume of targets for each treatment sites were investigated. Result : In stereotatictic body radiotherapy(SBRT) plan for lung, the average value of PTV coverage was reduced by 0.52 % with HD MLC. With SBRT plan using HD MLC for spine, the average value of PTV coverage decreased by 0.63 % and maximum dose decreased by 1.13 %. In the test of CI and HI, the values in SBRT plan with HD MLC for spine were 1.144, 1.079 and the values using M MLC were 1.160, 1.092 in SBRT plan for lung, The dose evaluation of critical organ was reduced by 1.48 % in the ipsilateral lung mean dose with HD MLC. In prostate cancer volumetric modulated arc therapy(VMAT) with HD MLC, the mean dose and the $V_{30}$ of bladder and the mean dose and the $V_{25}$ of rectum were reduced by 0.53 %, 1.42 %, 0.97 %, and 0.69 %, respectively (p<0.05). The average value of heart mean dose was reduced by 0.83 % in breast cancer VMAT with M MLC. Other assessment indices for treatment sites showed no significant difference between treatment plans with two types of MLC. Conclusion : Using HD MLC had a positive impact on the PTV coverage and normal tissue sparing in usually short or small targets such as lung and spine SBRT and prostate VMAT. But, there was no significant difference in targets with long and large such as lung, head and neck, and whole pelvis for VMAT.

• Progress in Medical Physics
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• v.27 no.2
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• pp.93-97
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• 2016

In this study, we evaluate the effect of respiration on the dose distribution in patient target volume (PTV) during intensity-modulated radiation therapy (IMRT) and research methods to reduce this impact. The dose distributions, homogeneity index (HI), coverage index (CVI), and conformity index of the PTV, which is calculated from the dose-volume histogram (DVH), are compared between the maximum intensity projection (MIP) image-based plan and other images at respiration phases of 30%, 60% and 90%. In addition, the reducing effect of complication caused by patient respiration is estimated in the case of a bolus and the expended PTV on the skin. The HI is increased by approximately twice, and the CVI is relatively decreased without the bolus at other respiration phases. With the bolus and expended PTV, the change in the dose distribution of the PTV is relatively small with patient respiration. Therefore, the usage of the bolus and expended PTV can be considered as one of the methods to improve the accuracy of IMRT in the treatment of breast cancer patients with respiratory motion.

• Progress in Medical Physics
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• v.13 no.4
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• pp.202-208
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• 2002

The purpose of this study is to evaluate the monitor unit obtained from various methods for the treatment of superficial cancers using electron beams. Thirty-three breast cancer patients who were treated in our institution with 6, 9, and 12 MeV electron beams, were selected for this study. For each patient, irregularly shaped treatment blocks were drawn on simulation film and constructed. Using the irregular blocks, monitor units to deliver 100 cGy to the dose maximum (dmax) were calculated from measurement and three-dimensional radiation treatment planning (3D RTP) system (PINNACLE 6.0, ADAC Laboratories, Milpitas CA) Measurements were made in solid water phantom with plane parallel (PP) chamber (Roos, OTW Germany) at 100 cm source-to surface distances. CT data was used to investigate the effect of heterogeneity. Monitor units were calculated by overriding CT values with 1 g/㎤ and in the presence of heterogeneity. The monitor unit values obtained by the above methods were compared. The dose, obtained from measurement in solid water phantom was higher than that of RTP values for irregularly shaped blocks. The maximum differences between monitor unit calculated in flat water phantom at gantry zero position were 4% for 6 MeV and 2% for 9 and 12 MeV electrons. When CT data was used at a various gantry angle the agreement between the TPS data with and without density correction was within 3% for all energies. These results indicate that there are no significant difference in terms of monitor unit when density is corrected for the treatment of breast cancer patients with electrons.

• Journal of Korean Neurosurgical Society
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• v.46 no.6
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• pp.538-544
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• 2009

Objective : Primary treatment of spinal metastasis has been external beam radiotherapy. Recent advance of technology enables radiosurgery to be extended to extracranial lesions. The purpose of this study was to determine the clinical effectiveness and safety of stereotactic radiosurgery using Cyberknife in spinal metastasis. Methods : From June, 2002 to December, 2007, 129 patients with 167 spinal metastases were treated with Cyberknife. Most of the patients (94%) presented with pain and nine patients suffered from motor deficits. Twelve patients were asymptomatic. Fifty-three patients (32%) had previous radiation therapy. Using Cyberknife, 16-39 Gy in 1-5 fractions were delivered to spinal metastatic lesions. Radiation dose was not different regarding the tumor pathology or tumor volume. Results : After six months follow-up, patient evaluation was possible in 108 lesions. Among them, significant pain relief was seen in 98 lesions (91%). Radiological data were obtained in 83 lesions. The mass size was decreased or stable in 75 lesions and increased in eight lesions. Radiological control failure cases were hepatocellular carcinoma (5 cases), lung cancer (1 case), breast cancer (1 case) and renal cell carcinoma (1 case). Treatment-related radiation injury was not detected. Conclusion : Cyberknife radiosurgery is clinically effective and safe for spinal metastases. It is true even in previously irradiated patients. Compared to conventional radiation therapy, Cyberknife shows higher pain control rate and its treatment process is more convenient for patients. Thus, it can be regarded as a primary treatment modality for spinal metastases.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9199-9202
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• 2014

Background: Kurdish women with breast cancer have more unfavorable prognostic factors than their Turkish and Arab counterparts. However, the effects of these factors on breast cancer survival among these ethnic groups remain unclear. We therefore investigated the impact of ethnicity on survival in breast cancer patients in Turkey. Materials and Methods: Ethnicity, age, stage at diagnosis, tumor characteristics, treatments given (surgery, chemotherapy, radiotherapy and hormone therapy), and survival times were recorded. Kaplan-Meier analysis was used to estimate the overall survival times and survival plots. Log-rank test was used to compare the survival curves.Results: Of the 723 breast cancer patients included in the study, 496 (68.7%) were Turkish, 189 (26.2%) were Kurdish, 37 (5.1%) were Arabic and 1 was Armenian. Kurdish women with breast cancer had larger tumor sizes and higher rates of hormone receptor negative tumors than Turkish and Arab patients. Mean follow-up time was 118.4 [95% Confidence Interval (CI): 95.4-141.3] months, and it was 129.9 (95% CI: 93.7-166.2), 124.2 (95% CI: 108.4-140.1) and 103.1 (95% CI: 85.9-120.4) months for Turkish, Arabic and Kurdish patients, respectively. Conclusions: Kurdish ethnicity is associated with higher rates of hormone receptor negative and triple-negative tumors and with worse survival. Clinical and epidemiological research is warranted to elucidate reasons underlying overall survival, variations in tumor biology, differences in treatment responsiveness, and effects of social factors among ethnic groups in Turkey.

• Archives of Plastic Surgery
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• v.42 no.5
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• pp.601-607
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• 2015

Background Autologous or implant-based breast reconstruction after nipple-sparing mastectomy is increasingly preferred worldwide as a breast cancer treatment option. However, postoperative nipple-areola complex (NAC) necrosis is the most significant complication of nipple-sparing mastectomy. The purpose of our study was to identify the risk factors for NAC necrosis, and to describe the use of our skin-banking technique as a solution. Methods We reviewed cases of immediate autologous breast reconstruction after nipple-sparing mastectomy at our institution between June 2005 and January 2014. The patients' data were reviewed and the risk of NAC necrosis was analyzed based on correlations between patient variables and NAC necrosis. Moreover, data pertaining to five high-risk patients who underwent the donor skin-banking procedure were included in the analysis. Results Eighty-five patients underwent immediate autologous breast reconstruction after nipple-sparing mastectomy during the study period. Partial or total NAC necrosis occurred in 36 patients (43.4%). Univariate analysis and binary regression modeling found that body mass index, smoking history, radiation therapy, and mastectomy volume were significantly associated with NAC necrosis. Of the 36 cases of NAC necrosis, 31 were resolved with dressing changes, debridement, or skin grafting. The other five high-risk patients underwent our prophylactic skin-banking technique during breast reconstruction surgery. Conclusions NAC necrosis is common in patients with multiple risk factors. The use of the skin-banking technique in immediate autologous breast reconstruction is an attractive option for high-risk patients. Banked skin can be used in such cases without requiring additional donor tissue, with good results in terms of aesthetic and reconstructive outcomes.

• Radiation Oncology Journal
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• v.23 no.3
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• pp.169-175
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• 2005

Purpose: Although computed tomography (CT) simulators are commonly used in radiation therapy department, many Institution still use conventional CT for treatments. In this study the setup errors that occur during simulation, CT scan (diagnostic CT scanner), and treatment were evaluated for the twenty one breast cancer patients. Materials and Methods: Errors were determined by calculating the differences in isocenter location, SSD, CLD, and locations of surgical clips implanted during surgery. The anatomic structures on simulation film and DRR image were compared to determine the movement of isocenter between simulation and CT scan. The isocetner point determined from the radio-opaque wires placed on patient's surface during CT scan was moved to new position if there was anatomic mismatch between the two images Results: In 7/21 patients, anatomic structures on DRR Image were different from the simulation Image thus new isocenter points were placed for treatment planning. The standard deviations of the diagnostic CT setup errors relative to the simulator setup in lateral, longitudinal, and anterior-posterior directions were 2.3, 1.6, and 1.6 mm, respectively. The average variation and standard deviation of SSD from AP field were 1.9 mm and 2.3 mm and from tangential fields were 2.8 mm and 3.7 mm. The variation of the CLD for the 21 patients ranged from 0 to 6 mm between simulation and DRR and 0 to 5 mm between simulation and treatment. The group systematic errors analyzed based on clip locations were 1.7 mm in lateral direction, 2.1 mm in AP direction, and 1.7 mm in SI direction. Conclusion: These results represent that there was no significant differences when SSD, CLD, clips' locations and isocenter locations were considered. Therefore, it is concluded that when a diagnostic CT scanner is used to acquire an image, the set-up variation is acceptable compared to using CT simulator for the treatment of breast cancer. However, the patient has to be positioned with care during CT scan in order to reduce the setup error between simulation and CT scan.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.279-286
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• 2014

The purpose of this study is to provide basic data of comparing BMD(bone mineral density) value of preoperative breast cancer patient and postoperative breast cancer patient due to bone loss with radiation/chemical therapy. The participants consisted of 254 breast cancer patients with BMD after having surgery and treatment from March 2007 to September 2013. Except for 84 patients with menopause or hysterectomy and we have analysed 171 patients. The BMD value(lumbar spine and femur) of before and after treatment from PACS by dure-energy X-ray absorptiometry was analyzed. First, we found variation of entire BMD and BMD according to treatment type, and analyzed detailed correlation by using marital status, number of children, presence of feeding, age of menarche, breast cancer therapy types as variable. Data was analyzed by using SPSS for Windows Program(version 18.0). BMD was decreased 7.1% in lumbar spine, 3.1% in femur respectively(p<.01). Also there is relatively high decrement($0.067g/cm^2$) in group who had just chemotherapy in femur(p<.05). There is decrement depend on marital status, number of children, presence of feeding, age of menarche, breast cancer therapy types but there was no statistical significance. The results show that BMD was decreased after treatment in premenopausal breast cancer patient, patient who had relatively high decrement need to be included high-risk group. As a result, aggressive prevention policy would be necessary.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.265-276
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• 2000

Purpose : Between January 1983 and December 1988, 218 female Patients with known breast cancer and positive axillary nodes were treated with adjuvant radiotherapy and chemotherapy following radical mastectomy. Treatment results were retrospectively analysed at the Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University of College of Medicine. Materials and Methods : The patients were classified into 3 groups; group I included II patients treated with adjuvant chemotherapy alone; in group 2, 52 patients treated with radiotherapy alone; and in group 3, n patients treated with combined chemo-radiotherapy. The mean age was 44 years and ranged from 27 to 70. The median follow-up time was 51 months. Results :Seven-year relapse free and overall survival rates were 56$\%$ and 67$\%$; in group 1, 50$\%$ and 56$\%$ in group 2, 51$\%$ and 65$\%$ and in group 3, 62$\%$ and 75$\%$ respectively. This difference was not statistically significant(p<0.05). The loco-regional failure rates were 13$\%$ and distant failure rates were 33$\%$. There was less risk of loco-regional failure in group 2 and 3 which included radiotherapy (p<0.05). But there was no significantly difference in the rates of distant failure( p>0.05). By univariate analysis, the only significant prognostic factor affecting relapse-free survival was the percentage of positive axillary nodes; and the overall survival significantly correlated with the primary tumor site, the number or percentage of positive axillary nodes, and stage. But in multivariate analysis, the only significant prognostic factor was treatment modality. By univariate analysis of prognostic factors affecting the rates of overall failure and distant failure, the significant prognostic factors was the percentage of positive axillary nodes; and the risk of the loco-regional failure significantly correlated with the treatment modality. Conclusion :In conclusion, these results suggest a potential for decreasing the risk of loco-regional failure with the addition of postoperative radiotherapy to chemotherapy in the premenopausal patients, and in the patients with number or percentage of positive nodes more than 4 or 1/3. The results of this study suggest that the combined chemo-radiotherapy as adjuvant treatment following radical mastectomy was the most effective modaliw in groups of 2$\~$5 cm sized tumor, stage IIB, and in patients with more than 4 or 1/3 of number or percentage of positive nodes.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.471-474
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• 2015

Background: Male and female breast cancers were investigated for variation in the clinicopathologic characteristics and expression of steroid hormone receptors in the northeast of Iran. Materials and Methods: Tumor specimens of 17 males and 338 females with breast cancer were collected at the hospitals of Mashhad University of Medical Sciences. Immunohistochemical expression of hormone receptors and clinicopathologic features of breast cancer were compared between two groups. Results: The mean age in men was 15 years higher than women (p=0.000). Males and females were mainly in stage II and III respectively (p=0.007). Although more than 60% of male and female patients were grade II, the respective figures for grade I and III were 25% and 12.5% in men but 7.1% and 27.2% in women respectively (p=0.025). ER was significantly more positive in men against women; 82.3% versus 53.4% (p=0.016). The related measures for PR was 58.8% and 50.3%, respectively (p=0.424). Males also showed significantly more ER expression than postmenopausal females; 82.3% versus 48.9% (p=0.010). Conclusions: Breast cancer in males and females contrasted in age at diagnosis, histological type, stage, grade and ER expression which emphasize they are separate diseases with different behaviors.