• Progress in Medical Physics
• /
• v.31 no.4
• /
• pp.153-162
• /
• 2020

Purpose: We aim to evaluate the accuracy and effectiveness of an automatically converted radiation therapy plan between Radixact machines by comparing the original plan with the transferred plan. Methods: The study involved a total of 20 patients for each randomly selected treatment site who received radiation treatment with Radixact. We set up the cheese phantom (Gammex RMI, Middleton, WI, USA) with an Exradin A1SL ion chamber (Standard Imaging, Madison, WI, USA) and GAFCHROMIC EBT3 film (International Specialty Products, Wayne, NJ, USA) inserted. We used three methods to evaluate an automatically converted radiation therapy plan using the features of the Plan transfer. First, we evaluated and compared Planning target volume (PTV) coverage (homogeneity index, HI; conformity index, CI) and organs at risk (OAR) dose statistics. Second, we compared the absolute dose using an ion chamber. Lastly, we analyzed gamma passing rates using film. Results: Our results showed that the difference in PTV coverage was 1.72% in HI and 0.17% in CI, and majority of the difference in OAR was within 1% across all sites. The difference (%) in absolute dose values was averaging 0.74%. In addition, the gamma passing rate was 99.64% for 3%/3 mm and 97.08% for 2%/2 mm. Conclusions: The Plan transfer function can be reliably used in appropriate situations.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.252-254
• /
• 2002

A new protocol for dosimetry in external beam radiotherapy is published by the Japan Society of Medical Physics (JSMP) in 2002. The protocol deals with proton and heavy ion beams as well as photon and electron beams, in accordance with IAEA Technical Report Series No. 398. To establish inter-institutional uniformity in proton beam dosimetry, an intercomparison program was carried out with the new protocol. The absorbed doses are measured with different cylindrical ionization chambers in a water phantom at a position of 30-mm residual range for a proton beam, that had range of 155 mm and a spread out Bragg peak (SOBP) of 60-mm width. As a result, the intercomparison showed that the use of the new protocol would improve the +/- 1.0 % (one standard deviation) and 2.7 % (maximum discrepancy) differences in absorbed doses stated by the participating institutions to +/- 0.3% and 0.9 %, respectively. The new protocol will be adopted by all of the participants.

• The Journal of Korean Physical Therapy
• /
• v.15 no.2
• /
• pp.131-145
• /
• 2003

The purpose of this study was to evaluate effects of artificial balenotherapy on the with degenerative osteoarthritis were selected as the subject do this study among the patients with degenerative osteoarthritis having pains in their knees by the criteria of America Rheumatoid Association. And the randomly selected ten patients out of the twenty were classified as an artificial balenotherapy group and the other the Patients were in a control group. Ten individuals with degenerative osteoarthritis patients in the artificial balenotherapy group Participated in artificial balenotherapy Program four weeks from March 1st, 2003 to March 31st, 2003 in Daegu 00 hospital. Ten individuals with degenerative osteoarthritis in the control group did not receive Artificial Balenotherapy. The conclusions were as follows: 1. After 4 weeks of therapy, the score of WBC(p < 0.01), RBC(p < 0.01), HTC(p < 0.01) in the artificial blalenotherapy group were significantly decreased, compared with their scores in pre-intervention. 2.In the balenotherapy group, significantly increase $Na^{+}$ ion(P < 0.05), decrease K ion(p < 0.01), unchanged Cl ion scores were found, compared with their scores in pro-intervention. 3. The result of the substudy about the effects of artificial balenotherapy on the substances that have relations with the function of liver were following that artificial balenotherapy group, increased total bilirubin(P < 0.01), unchanged total Protein, Albumin, total cholesterol, GOT, GPT, ALP were found, compared with their score in pre-intervention. 4. The result of the substudy about the effects of artificial balenotherapy on the substances that have relations with the function of kidney were following that in the artificial balenotherapy group, reduced BUN(P < 0.05), and increased creatine were found. 5. The result of the substudy about effects of artificial balenotherapy on the knee pain visual analog score, knee's functional score, ADL score were following that in the artificial balenotherapy group, decreased VAS score(P < 0.05), increased ADL score(p < 0.01), unchanged knee's functional score were founf, compared with their scores of the pre-intervention. In conclusion, the result of this study suggest that artificial balenotherapy improved ADL score and reduced knee pain visual analog score of the patients with degenerative osteoarthritis. The result proposed that appropriate use of artificial balenotherapy improves the degenerative osteoarthritis

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.222-224
• /
• 2002

In proton and heavy ion radiotherapy, compensators are required to modify the energy of heavy ion, to compensate the local difference of tumor depth. Conventional compensators have to be created, exchanged, and stored for each patient and for each irradiation directions. A Cylinder Type Liquid Variable Compensator is and is under development. Hexagonal cylinders will be arranged in honeycomb structure. In which air and fluid are divided by hexagonal pistons. The position of each piston will be changed in each cylinder for adjusting the thickness of fluid for variable compensator. The location of each hexagonal piston is determined by each controlling cylinder connected to the hexagonal cylinder by inlet pipes of fluid. Each controlling cylinder includes controlling a piston, which is moved mechanically. Each controlling cylinder is to be moved by a motor driven by a computer.

• The Journal of Korean Society for Radiation Therapy
• /
• v.18 no.1
• /
• pp.1-5
• /
• 2006

Purpose: IMRT quality assurance(Q.A) is consist of the absolute dosimetry using ionization chamber and relative dosimetry using the film. We have in general used 0.015 cc ionization chamber, because small size and measure the point dose. But this ionization chamber is too small to give an accurate measurement value. In this study, we have examined the degree of calculated to measured dose difference in intensity modulated radiotherapy(IMRT) based on the observed/expected ratio using various kinds of ion chambers, which were used for absolute dosimetry. Materials and Methods: we peformed the 6 cases of IMRT sliding-window method for head and neck cases. Radiation was delivered by using a Clinac 21EX unit(Varian, USA) generating a 6 MV x-ray beam, which is equipped with an integrated multileaf collimator. The dose rate for IMRT treatment is set to 300 MU/min. The ion chamber was located 5cm below the surface of phantom giving 100cm as a source-axis distance(SAD). The various types of ion chambers were used including 0.015cc(pin point type 31014, PTW. Germany), 0.125 cc(micro type 31002, PTW, Germany) and 0.6 cc(famer type 30002, PTW, Germany). The measurement point was carefully chosen to be located at low-gradient area. Results: The experimental results show that the average differences between plan value and measured value are ${\pm}0.91%$ for 0.015 cc pin point chamber, ${\pm}0.52%$ for 0.125 cc micro type chamber and ${\pm}0.76%$ for farmer type 0.6cc chamber. The 0.125 cc micro type chamber is appropriate size for dose measure in IMRT. Conclusion: IMRT Q.A is the important procedure. Based on the various types of ion chamber measurements, we have demonstrated that the dose discrepancy between calculated dose distribution and measured dose distribution for IMRT plans is dependent on the size of ion chambers. The reason is small size ionization chamber have the high signal-to-noise ratio and big size ionization chamber is not located accurate measurement point. Therefore our results suggest the 0.125 cc farmer type chamber is appropriate size for dose measure in IMRT.

• Radiation Oncology Journal
• /
• v.29 no.3
• /
• pp.135-146
• /
• 2011

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfi ll the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest.

• International Journal of Advanced Culture Technology
• /
• v.4 no.4
• /
• pp.45-50
• /
• 2016

This is a humanistic study to trace phenomena logically the comprehensive therapeutic mechanism of the human body which is coded by the smart emotion of the rated signal conveyed by the Rated Sijo. The Gestalt, which is structured in the form of therapeutic metastasis conveyed by sentences, is intended to embody the principle of human response. So, this researcher explored the metastatic structure toward Gestalt of original human being through the passage of foreground and background by ergonomic and chemical structure. In the meantime, this researcher focused on revealing the structure of the field of existence by the symbol system in which the therapeutic mechanism of the human body is embodied. As a result, the basic framework of Gestalt literary therapy, which contributes to the improvement of the Quality of Life metaphorized as a mechanism of the symbol system by the metastasis of literary therapy or the electrical operation of the human body. As a result, the human body as a conductor through literature has turned out to be an original Gestalt structure pursued by literature. In addition, it was analyzed that the human body would accept signals such as emotions and Rated Emotions planted in the sentence, and synapse them into the human physiological psycho analytical symbol system. Therefore, it has been confirmed possibility that human existent environment and trauma are separated from the whole universe can push fully implement therapeutic techniques toward totalization by a combination of literary devices, especially appropriate electric signal combination of the Rated Sijo.

• Progress in Medical Physics
• /
• v.33 no.4
• /
• pp.53-62
• /
• 2022

In this study, we have investigated the shielding evaluation methodology for facilities using kV energy generators. We have collected and analysis of safety evaluation criteria and methodology for overseas facilities using radiation generators. And we investigated the current status of shielding evaluation of domestic industrial radiation generators. According to the statistical data from the Radiation Safety Information System, as of 2022, a total of 7,679 organizations are using radiation generating devices. Among them, 6,299 facilities use these devices for industrial purposes, which accounts for a considerable portion of radiation. The organizations that use these devices evaluate whether the exposure dose for workers and frequent visitors is suitable as per the limit regulated by the Nuclear Safety Act. Moreover, during this process, the safety shields are evaluated at the facilities that use the radiation generating devices. However, the facilities that use radiating devices having energy less than or equal to 6 MV for industrial purposes are still mostly evaluated and analyzed according to the National Council on Radiation Protection and Measurements 49 (NCRP 49) report published in 1976. We have investigated the technical standards of safety management, including the maximum permissible dose and parameters assessment criteria for facilities using radiation generating devices, based on the NCRP 49 and the American National Standards Institute/Health Physics Society N.43.3 reports, which are the representative reports related to radiation shielding management cases overseas.

• Nuclear Engineering and Technology
• /
• v.55 no.10
• /
• pp.3854-3859
• /
• 2023

Background: This study aims to develop an evaluator that can quickly and accurately evaluate the shielding of low-energy industrial radiation generators. Methods: We used PyQt to develop a graphical user interface (GUI)-based program and employed the calculation methodology reported in the National Council on Radiation Protection and Measurements (NCRP)-49 for shielding calculations. We gathered the necessary factors for shielding evaluation using two libraries designed for Python, pandas and NumPy, and processed them into a database. We verified the effectiveness of the proposed program by comparing the results with those from safety reports of six domestic facilities. Results: After verifying the effectiveness of the program using the NCRP-49 example, we obtained an average error rate of 1.73%. When comparing the facility safety report and results obtained using the program, we found that the error rate was between 1.09% and 6.51%. However, facilities that did not use a defined shielding methodology were underestimated by 31.82% compared with the program (the final barrier thickness satisfied the shielding standard). Conclusion: The developed program provides a fast and accurate shielding evaluation that can assist personnel that work in radiation generator facilities and government officials in reviewing safety.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.94-96
• /
• 2002

In order to achieve the radiotherapy more precisely using highly energetic heavy charged particles, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. We can directly obtain the 2-D distribution of the electron density in a sample from a heavy ion CT image. For this purpose, we have developed a heavy ion CT system using a broad beam. The performance, especially the position resolution, of this system is estimated in this work. All experiments were carried out using the heavy ion beam from the HIMAC. We have obtained the projection data of polyethylene samples with various sizes using He 150 MeV/u, C 290 MeV/u and Ne 400 MeV/u beams. The used targets are the cylinders of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. The dependence of the spatial resolution on the target size and the kinds of beams will be discussed.