• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.83-85
• /
• 2002

Yonsei Cancer Center introduced an IMRT System at the beginning of February, 2002. The system consists of CORVUS(NOMOS) inverse planning machine, LANTIS(SIEMENS), PRIMEVIEW and PRIMART Linac(SIEMENS). The optimization of CORVUS planning system with PRIMART is an important work to get an efficient treatment plan. So, we studied two Finite Size Pencil Beams, 1.0 x 1.0 cm$^2$ and 0.5 x 1.0 cm$^2$, and four leaf transmission sets, 5%, 10%, 20%, 33%. We compared the dose distribution of target volume and delivery efficiency of the plan results.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.177-179
• /
• 2002

We have developed a scheduling system for heavy ion radiotherapy considering the condition of three treatment rooms and treatment planning for each patient. This system consists of a database (patient information, treatment method and machine schedule), a schedule for radiotherapy and WEB server. All operation of this system, such as data input, to change and to view the schedule, are performed by using a WEB browser. In order to protect personal information for the patients, access privilege to each information are limited by according to the occupational category. This system is connected with a hospital central information management system (AMIDAS) and an irradiation-managing computer for the heavy ion radiotherapy. A basic information for the patient is got from AMIDAS and the daily schedule sends to the treatment control computer at each treatment room through the irradiation-managing computer every morning. The daily, weekly, monthly schedules in the treatment room and the treatment condition of each patient are shared on the WEB browser with the all participants of the heavy ion therapy. This system could be useful to save a time to generate a treatment schedule and to inform us the most up-to-date treatment schedule and the related information at the same time.

• Journal of Korean Neurosurgical Society
• /
• 제53권2호
• /
• pp.102-107
• /
• 2013

Objective : The Leksell Gamma Knife$^{(R)}$ (LGK) is based on a single-fraction high dose treatment strategy. Therefore, independent verification of the Leksell GammaPlan$^{(R)}$ (LGP) is important for ensuring patient safety and minimizing the risk of treatment errors. Although several verification techniques have been previously developed and reported, no method has ever been tested statistically on multiple LGK target treatments. The purpose of this study was to perform and to evaluate the accuracy of a verification method (modified variable ellipsoid modeling technique, MVEMT) for multiple target treatments. Methods : A total of 500 locations in 10 consecutive patients with multiple brain tumor targets were included in this study. We compared the data from an LGP planning system and MVEMT in terms of dose at random points, maximal dose points, and target volumes. All data was analyzed by t-test and the Bland-Altman plot, which are statistical methods used to compare two different measurement techniques. Results : No statistical difference in dose at the 500 random points was observed between LGP and MVEMT. Differences in maximal dose ranged from -2.4% to 6.1%. An average distance of 1.6 mm between the maximal dose points was observed when comparing the two methods. Conclusion : Statistical analyses demonstrated that MVEMT was in excellent agreement with LGP when planning for radiosurgery involving multiple target treatments. MVEMT is a useful, independent tool for planning multiple target treatment that provides statistically identical data to that produced by LGP. Findings from the present study indicate that MVEMT can be used as a reference dose verification system for multiple tumors.

• 산업경영시스템학회지
• /
• 제42권2호
• /
• pp.9-17
• /
• 2019

In order to deal with high uncertainty and variability in emergency medical centers, many researchers have developed various models for their operational planning and scheduling. However, most of the models just provide static plans without any risk measures as their results, and thus the users often lose the opportunity to analyze how much risk the patients have, whether the plan is still implementable or how the plan should be changed when an unexpected event happens. In this study, we construct a simulation model combined with a risk-based planning and scheduling module designed by Simio LLC. In addition to static schedules, it provides possibility of treatment delay for each patient as a risk measure, and updates the schedule to avoid the risk when it is needed. By using the simulation model, the users can experiment various scenarios in operations quickly, and also can make a decision not based on their past experience or intuition but based on scientific estimation of risks even in urgent situations. An example of such an operational decision making process is demonstrated for a real mid-size emergency medical center located in Seoul, Republic of Korea. The model is designed for temporal short-term planning especially, but it can be expanded for long-term planning also with some appropriate adjustments.

• Radiation Oncology Journal
• /
• 제7권1호
• /
• pp.101-112
• /
• 1989

The treatment planning and dosimetry of small fields for stereotactic radiosurgery with 10 MV x-ray isocentrically mounted linear accelerator is presented. Special consideration in this study was given to the variation of absorbed dose with field size, the central axis percent depth doses and the combined moving beam dose distribution. The collimator scatter correction factors of small fields $(1\times1\~3\times3cm^2)$ were measured with ion chamber at a target chamber distance of 300cm where the projected fields were larger than the polystyrene buildup caps and it was calibrated with the tissue equivalent solid state detectors of small size (TLD, PLD, ESR and semiconductors). The central axis percent depth doses for $1\timesl\;and\;3\times3cm^2$ fields could be derived with the same acuracy by interpolating between measured values for larger fields and calculated zero area data, and it was also calibrated with semiconductor detectors. The agreement between experimental and calculated data was found to be under $2\%$ within the fields. The three dimensional dose planning of stereotactic focusing irradiation on small size tumor regions was performed with dose planning computer system (Therac 2300) and was verified with film dosimetry. The more the number of strips and the wider the angle of arc rotation, the larger were the dose delivered on tumor and the less the dose to surrounding the normal tissues. The circular cone, we designed, improves the alignment, minimizes the penumbra of the beam and formats ball shape of treatment area without stellate patterns. These dosimetric techniques can provide adequate physics background for stereotactic radiosurgery with small radiation fields and 10MV x-ray beam.

• Journal of Magnetics
• /
• 제21권3호
• /
• pp.425-430
• /
• 2016

The aim of this study was to measure the setup variation for X (lateral), Y (longitude), and Z (vertical) by taking magnetic megavoltage computed tomography (MVCT) before treating the brain, oropharynx, lung, and prostate patients on helical tomotherapy. In this study, 30 patients were chosen for each of the treatment areas, and their skin was labeled with a mark on a treatment planning reference point when taking CT. We preceded MVCT prior to tomotherapy and then conducted an auto registration based on the bony landmarks; image registration was used for automatically matching the patient's setup. Lastly, we confirmed and evaluated the translation coordinates of the images for 30 patients. The following shows the comparison result of the setup errors of each part: X (lateral) showed the highest setup errors with $3.44{\pm}2.05$ from Lung; Y (longitude) showed the highest setup errors showing $3.40{\pm}2.87mm$ from Prostate; and Z (vertical) showed the highest setup errors showing $6.62{\pm}4.38mm$ from Lung. This result verifies that the setup error can be prevented by taking MVCT before the treatment, and Planning Target Volume (PTV) margins can be reduced by referring to the resulting value of each treatment part. Ultimately, the dosage of the normal organs can be decreased as well as any side effects.

• 대한치과의사협회지
• /
• 제25권9호통권220호
• /
• pp.847-854
• /
• 1987

Genioplasty may considerably change a person's face which needs surgical correction of deformed chin. Comprehensive treatment planning is therefore decisive for the treatment to be successful. A three-dimensional analysis of chin relative to cranial base, upper and lower jaws using the frontal and lateral facial photographs and cephalographs permits classification of the defective chin position and provides a basis for operation planning and deciding upon the operation method. A chin miniplate system has been developed for intraoperative registration securing the sagittal, vertical and horizontal position of the osteotomized chin and ould reduce the relapse rate.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.302-304
• /
• 2002

In linac-based stereotactic radiosurgery, assuring the quality of the planning and delivery of external photon beam requires accurate evaluation of beam parameters, usually including output factors, tissue-phantom ratio and off-axis ratios, and measurement of actual dose distributions from simulated treatment. We're going to test the use of calibrated radio chromic film (Gafchromic film; type MD-55, Nuclear associate) using a Lumiscan 75 digitizer to measure absolute dose and relative dose distributions for linac-based radiosurgery unit Relative dose distribution of a human-style spherical acryl phantom were measured using radiochromic film and calculated by treatment planning system. The absolute dose at the sphere center was measured by radiochromic film and micro chamber (Exradin A-14, 0.009cc). What we want to demonstrate in this work, the 'well selected' radiochromic films when external photon beam are used in linac-based stereotactic radiosurgery are very accurate detector for dosimetry.

• 대한방사선치료학회지
• /
• 제22권1호
• /
• pp.41-46
• /
• 2010

목 적: 유방암의 접선조사 시 쐐기필터를 이용한 Conventional RT 기법과 정적다엽조리개를 이용한 FiF-IMRT 기법을 이용하여 전산화 치료계획 시 발생하는 선량분포의 차이를 환자의 유방 크기와 형태에 따라 분류하여 비교 분석하고자 한다. 대상 및 방법: 유방암 환자 30명을 대상으로 Eclipse treatment planning system ($Varian^{TM}$, USA, V8.0)을 사용하여 전산화 치료 계획을 시행하여 유방의 크기와 형태에 따라 분류하고, Dose Volume Histogram (DVH)을 이용하여 Conformity Index (CI)와 Homogeneity Index (HI)를 비교 분석하였다. 결 과: CI값은 ${\pm}1.2%$의 차이를 나타냈으며 FiF-IMRT의 경우 Conventional RT보다 HI값이 평균 1.67% 낮은 값으로 유방의 크기와 형태에 따른 분류값과 ${\Delta}HI$ (%)값의 상관관계를 알아본 결과 단면길이와 부피에서 높은 상관관계를 보였으며 통계적으로 유의(P<0.01)하였다. 결 론: 유방의 단면 길이와 부피가 증가할수록 Conventional RT의 경우보다 FiF-IMRT로 전산화 치료계획 시 유방 내의 선량 균등성이 향상되었으며 유방의 크기에 따라 그 효과가 다르므로 유방의 크기에 따른 적절한 치료계획이 필요할 것으로 생각된다.

• 구강회복응용과학지
• /
• 제23권2호
• /
• pp.139-144
• /
• 2007

Prosthodontic treatment planning for various edentulous arches is not an easy issue for dentists. Especially, in case of removable partial denture, we must have a knowledge of overall treatment procedures, and a careful approach is needed. Recently, interest of dental implant and case reports are increasing, the decrease of the removable partial denture is true, but dental implantation takes longer treatment period and it is more expensive. Also, there are still some limitations like lack of available alveolar bone, patient's general condition, and chronic periodontitis. Therefore, sometimes implantation is impossible. Finally, implantation cannot be adapted to every single patient. Currently, the clasp type removable partial dentures are used routinely, giving patients many unesthetic and functional difficulties. With better laboratory technique, removable partial denture with attachment and removable partial denture in rigid type increase patient's happiness level much more than predicted. The case presented in this article, clinically demonstrate the efficiency of using a telescopic system to improve esthetic and functional recovery for patients who lose multiple teeth.