• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.633-640
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• 2023

With the recent development of static and dynamic modulated brachytherapy methods in brachytherapy, which use radiation shielding to modulate the dose distribution to deliver the dose, the amount of parameters and data required for dose calculation in inverse treatment planning and treatment plan optimization algorithms suitable for new directional beam intensity modulated brachytherapy is increasing. Although intensity-modulated brachytherapy enables accurate dose delivery of radiation, the increased amount of parameters and data increases the elapsed time required for dose calculation. In this study, a GPU-based CUDA-accelerated dose calculation algorithm was constructed to reduce the increase in dose calculation elapsed time. The acceleration of the calculation process was achieved by parallelizing the calculation of the system matrix of the volume of interest and the dose calculation. The developed algorithms were all performed in the same computing environment with an Intel (3.7 GHz, 6-core) CPU and a single NVIDIA GTX 1080ti graphics card, and the dose calculation time was evaluated by measuring only the dose calculation time, excluding the additional time required for loading data from disk and preprocessing operations. The results showed that the accelerated algorithm reduced the dose calculation time by about 30 times compared to the CPU-only calculation. The accelerated dose calculation algorithm can be expected to speed up treatment planning when new treatment plans need to be created to account for daily variations in applicator movement, such as in adaptive radiotherapy, or when dose calculation needs to account for changing parameters, such as in dynamically modulated brachytherapy.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.177-182
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• 2014

Purpose : The goal of this study was to compare and analysis the dose distribution and treatment time between Tomotherapy planning with fixed jaw(FJ) and dynamic jaw(DJ). Materials and Methods : Seven patients were selected in the study including five common clinical cases(brain, head and neck(HN), lung, prostate, spine). 1) Helical Tomotherapy plans with FJ and DJ were generated with the same planning parameters such as Modulation factor, Pitch and Field width. 2) Tomo_edge plans with a larger field width were generated to compare to conventional HT delivery with fixed jaw. Dosimetric evaluation indices for target coverage are Dmin, Conformity index(CI) and for whole body including target are $V_{10%}$, $V_{25%}$, $V_{50%}$, $V_{75%}$ using Dose-volume histogram(DVH). Also, Treatment time and Cumulative MU were used for clinical review on Tomo_edge. Results : In case of using the same field width of Tomotherapy planning with FJ and DJ, the averaged variations were $V_{10%}$: -11.91%, $V_{25%}$: -7.6%, $V_{50%}$ :-4.75%, $V_{75%}$: -1.04%. Tomo_edge with a larger field width provides the averaged variations for target coverage: Dmin: -0.72%, CI: -1.25% and also shows the tendency of a sharp $V_{x%}$ decline in low dose area. The clinical improvements in the larger field width with DJ were observed in the treatment time, ranging from -51.21% to -15.11, and the Cumulative MU decrease, ranging from -57.74% to -15.31%. Conclusion : Target coverage achieved by FJ and DJ with the same field width has little differences. But integral doses on whole body efficiently decreased. Compared to the conventional HT delivery, Tomo_edge with a larger field width presents a little worse target coverage. However, it provides faster treatment delivery and improved cranial-caudal target dose conformity. Therefore, Tomo_edge mode is efficient in improving the treatment time and integral dose while maintaining comparable plan quality in clinic.

• Progress in Medical Physics
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• v.26 no.4
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• pp.280-285
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• 2015

In radiation therapy fields, a brachytherapy is a treatment that kills lesion of cells by inserting a radioisotope that keeps emitting radiation into the body. We currently verify the consistency of radiation treatment plan and dose distribution through film/screen system (F/S system), provide therapy after checking dose. When we check dose distribution, F/S systems have radiation signal distortion because there is low resolution by penumbra depending on the condition of film developed. In this study, We fabricated a $HgI_2$ Semiconductor radiation sensor for base study in order that we verify the real dose distribution weather it's same as plans or not in brachytherapy. Also, we attempt to evaluate the feasibility of QA system by utilizing and evaluating the sensor to brachytherapy source. As shown in the result of detected signal with various source-to-detector distance (SDD), we quantitatively verified the real range of treatment which is also equivalent to treatment plans because only the low signal estimated as scatters was measured beyond the range of treatment. And the result of experiment that we access reproducibility on the same condition of ${\gamma}$-ray, we have made sure that the CV (coefficient of variation) is within 1.5 percent so we consider that the $HgI_2$ sensor is available at QA of brachytherapy based on the result.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.125-134
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• 2014

This study is to provide basic information regarding photoneutron doses in terms of radiation treatment techniques and the number of portals in intensity-modulated radiation therapy (IMRT) by measuring the photoneutron doses. Subjects of experiment were 10 patients who were diagnosed with prostate cancer and have received radiation treatment for 5 months from September 2013 to January 2014 in the department of radiation oncology in S hospital located in Seoul. Thus, radiation treatment plans were created for 3-Dimensional Conformal Radiotherapy (3D-CRT), Volumetric-Modulated Arc Radiotherapy (VMAT), IMRT 5, 7, and 9 portals. The average difference of photoneutron dose was compared through descriptive statistics and variance analysis, and analyzed influence factors through correlation analysis and regression analysis. In summarized results, 3D-CRT showed the lowest average photoneutron dose, while IMRT caused the highest dose with statistically significance (p <.01). The photoneutron dose by number of portals of IMRT was $4.37{\pm}1.08mSv$ in average and statistically showed very significant difference among the number of portals (p <.01). Number of portals and photoneutron dose are shown that the correlation coefficient is 0.570, highly statistically significant positive correlation (p <.01). As a result of the linear regression analysis of number of portals and photoneutron dose, it showed that photoneutron dose significantly increased by 0.373 times in average as the number of portals increased by 1 stage. In conclusion, this study can be expected to be used as a quantitative basic data to select an appropriate IMRT plans regarding photoneutron dose in radiation treatment for prostate cancer.

• The Journal of Korean Society for Radiation Therapy
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• v.32
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• pp.17-29
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• 2020

Purpose: The purpose of this work was to investigate the dosimetric impact of mixed energy partial arc technique on prostate cancer VMAT. Materials and Methods: This study involved prostate only patients planned with 70Gy in 30 fractions to the planning target volume (PTV). Femoral heads, Bladder and Rectum were considered as oragan at risk (OARs). For this study, mixed energy partial arcs (MEPA) were generated with gantry angle set to 180°~230°, 310°~50° for 6MV arc and 130°~50°, 310°~230° for 15MV arc. Each arc set the avoidance sector which is gantry angle 230°~310°, 50°~130° at first arc and 50°~310° at second arc. After that, two plans were summed and were analyzed the dosimetry parameter of each structure such as Maximum dose, Mean dose, D2%, Homogeneity index (HI) and Conformity Index (CI) for PTV and Maximum dose, Mean dose, V70Gy, V50Gy, V30Gy, and V20Gy for OARs and Monitor Unit (MU) with 6MV 1 ARC, 6MV, 10MV, 15MV 2 ARC plan. Results: In MEPA, the maximum dose, mean dose and D2% were lower than 6MV 1 ARC plan(p<0.0005). However, the average difference of maximum dose was 0.24%, 0.39%, 0.60% (p<0.450, 0.321, 0.139) higher than 6MV, 10MV, 15MV 2 ARC plan, respectively and D2% was 0.42%, 0.49%, 0.59% (p<0.073, 0.087, 0.033) higher than compared plans. The average difference of mean dose was 0.09% lower than 10MV 2 ARC plan, but it is 0.27%, 0.12% (p<0.184, 0.521) higher than 6MV 2 ARC, 15MV 2 ARC plan, respectively. HI was 0.064±0.006 which is the lowest value (p<0.005, 0.357, 0.273, 0.801) among the all plans. For CI, there was no significant differences which were 1.12±0.038 in MEPA, 1.12±0.036, 1.11±0.024, 1.11±0.030, 1.12±0.027 in 6MV 1 ARC, 6MV, 10MV, 15MV 2 ARC, respectively. MEPA produced significantly lower rectum dose. Especially, V70Gy, V50Gy, V30Gy, V20Gy were 3.40, 16.79, 37.86, 48.09 that were lower than other plans. For bladder dose, V30Gy, V20Gy were lower than other plans. However, the mean dose of both femoral head were 9.69±2.93, 9.88±2.5 which were 2.8Gy~3.28Gy higher than other plans. The mean MU of MEPA were 19.53% lower than 6MV 1 ARC, 5.7% lower than 10MV 2 ARC respectively. Conclusion: This study for prostate radiotherapy demonstrated that a choice of MEPA VMAT has the potential to minimize doses to OARs and improve homogeneity to PTV at the expense of a moderate increase in maximum and mean dose to the femoral heads.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.137-147
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• 2012

Purpose: Analyze the Effectiveness of Radiation Treatment Planning by dose calculation and optimization algorithm, apply consideration of actual treatment planning, and then suggest the best way to treatment planning protocol. Materials and Methods: The treatment planning system use Eclipse 10.0. (Varian, USA). PBC (Pencil Beam Convolution) and AAA (Anisotropic Analytical Algorithm) Apply to Dose calculation, DVO (Dose Volume Optimizer 10.0.28) used for optimized algorithm of Intensity Modulated Radiation Therapy (IMRT), PRO II (Progressive Resolution Optimizer V 8.9.17) and PRO III (Progressive Resolution Optimizer V 10.0.28) used for optimized algorithm of VAMT. A phantom for experiment virtually created at treatment planning system, $30{\times}30{\times}30$ cm sized, homogeneous density (HU: 0) and heterogeneous density that inserted air assumed material (HU: -1,000). Apply to clinical treatment planning on the basis of general treatment planning feature analyzed with Phantom planning. Results: In homogeneous density phantom, PBC and AAA show 65.2% PDD (6 MV, 10 cm) both, In heterogeneous density phantom, also show similar PDD value before meet with low density material, but they show different dose curve in air territory, PDD 10 cm showed 75%, 73% each after penetrate phantom. 3D treatment plan in same MU, AAA treatment planning shows low dose at Lung included area. 2D POP treatment plan with 15 MV of cervical vertebral region include trachea and lung area, Conformity Index (ICRU 62) is 0.95 in PBC calculation and 0.93 in AAA. DVO DVH and Dose calculation DVH are showed equal value in IMRT treatment plan. But AAA calculation shows lack of dose compared with DVO result which is satisfactory condition. Optimizing VMAT treatment plans using PRO II obtained results were satisfactory, but lower density area showed lack of dose in dose calculations. PRO III, but optimizing the dose calculation results were similar with optimized the same conditions once more. Conclusion: In this study, do not judge the rightness of the dose calculation algorithm. However, analyzing the characteristics of the dose distribution represented by each algorithm, especially, a method for the optimal treatment plan can be presented when make a treatment plan. by considering optimized algorithm factors of the IMRT or VMAT that needs to optimization make a treatment plan.

• Journal of radiological science and technology
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• v.36 no.3
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• pp.237-244
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• 2013

The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OED(Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ~ 2.02 Gy, 0.36 ~ 5.01 Gy, 0.25 ~ 2.49 Gy, 0.14 ~ 6.92 Gy, 0.03 ~ 2.02 Gy, 0.01 ~ 1.06 Gy, 0.25 ~ 6.08 Gy, 0.08 ~ 0.59 Gy, 0.01 ~ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

• Journal of radiological science and technology
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• v.27 no.3
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• pp.59-69
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• 2004

By studying on the characteristics of cancer patients who receive radiotherapy and the attitudes of medical social workers, this thesis aims to suggest of requirements for medical social work intervention. The study was conducted using SPSS 10.0 for Windows to analyze data taken from a survey involving 90 cancer patients receiving radiotherapy in 4 general hospitals in Daejeon city. The data were collected form Oct. 1st to 15th, 2003, and its analyses used averages, correlation, and regression. The results were summarized as follows ; 1. The average family income in 67.8% of the cases was less than 2,000,000 won, which is a lower income bracket. In the disease characteristics, fatigue ware the highest (2.78) in the side effects of radiotherapy, which most patients were receiving alongside other forms of treatment. 2. It was shown that cancer patients receiving radiotherapy receive a high level of psychological and social support from doctors and other medical staffs, and that they also received a high average (4.38) of individual care and encouragement from family members. 3. In the psychosocial status, the need for financial assistance in the form of a national aid program or an expansion of medical insurance was great, especially in the need for house keeping service and night nurses. The need for psychosocial counselling rose following rises in treatment side effects and depression. Information for cancer patients was especially needed in the areas of treatment plans, treatment costs, and side effects of radiotherapy. The need for information rose in accordance with an elongation of hospital treatment and an escalation of care from family members.

• The Journal of Korean Society for School & Community Health Education
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• v.2 no.1
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• pp.41-52
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• 2001

The purpose of this research is to plan the activation of university health business through the appraisal of the function and role of university health centers. To be more specific: Firstly, analyze the facility, personnel, health service of the health centers, Secondly, appraise the role and function of the health centers, and Thirdly, consider the activation plans of health centers. The research method taken was the study of surveys conducted and written research materials on 5 women's universities in Seoul. These materials where descriptively analyzed by converting the surveys, facility and usage of health center and current personnel status in to percentage. The major results of the research are as follows: Unlike as stated in each university's additional clause on the number of personnel were working. This lack of specialized personnel resulted into lack of specialized and various services. Medicine for external application were stocked well whereas only simple medicine for internal application were on shelf and were issued only with a doctor's prescription. Universities with a full-time doctor had various available equipments. One university conducting dental treatment was equipped with indirect chest camera, dental X-ray, unit, chair(dental treatment chair) and even supersonic, electrocardiogram were available. In the case of D women's university, the number of beds compared to the number of students was lower than that of the other 3 universities, to the total size of the university was smaller than that of the other 3 universities. Among health prevention and care matters, health consultation was the only matter practised by all universities. Uniquely, there was one university that hosted epidemic prevention business. There are various tests given by each university, with each showing many differences, but some universities did not even conduct these tests. Vaccinations were usually being conducted through commission. All universities provided basic treatment, therefore matters concerning treatment at health centers were being conducted well. Concerning the management of equipment and documents, all the matters were being conducted except one university where instead of a student medical record, they were using a daily record. Because these were women's universities, most of the educations were on women's health. The subjects of these educations included: sex, contraception, prevention and control of tuberculosis, obesity, mouth hygiene, alcohol, geriatric disease, mental health and first-aid. The rate of health center usage is growing. Being women's universities, the service and treatment practised were mostly concerning sex education.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.399-408
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• 1998

Purpose : This study was designed to demonstrate the potential therapeutic advantage of 3-dimensional (3-D) treatment planning over the conventional 2-dimensional (2-D) approach in patients with carcinoma of the nasopharynx. Materials and Methods : The two techniques were compared both qualitatively and quantitatively for the boost portion of the treatment (19.8 Gy of a total 70.2 Gy treatment schedule) in patient with T4. The comparisons between 2-D and 3-D plans were made using dose statistics, dose-volume histogram, tumor control probabilities, and normal tissue complication probabilities. Results : The 3-D treatment planning improved the dose homogeneity in the planning target volume. In addition, it caused the mean dose of the planning target volume to increase by 15.2$\%$ over 2-D planning. The mean dose to normal structures such as the temporal lobe, brain stem, parotid gland, and temporomandibular joint was reduced with the 3-D plan. The probability of tumor control was increased by 6$\%$ with 3-D treatment planning compared to the 2-D planning, while the probability of normal tissue complication was reduced. Conclusion : This study demonstrated the potential advantage of increasing the tumor control by using 3-D planning. but prospective studies are required to define the true clinical benefit.