• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.45-52
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• 2015

Purpose : The dose distribution of organ at risk (OAR) and normal tissue is affected by treatment technique in postoperative radiation therapy for prostate cancer. The aim of this study was to compare dose distribution characteristic and to evaluate treatment efficiency by devising VMAT plans according to applying differed number of arc and IMRT plan for postoperative patient of prostate cancer radiation therapy using a rectal balloon. Materials and Methods : Ten patients who received postoperative prostate radiation therapy in our hospital were compared. CT images of patients who inserted rectal balloon were acquired with 3 mm thickness and 10 MV energy of HD120MLC equipped Truebeam STx (Varian, Palo Alto, USA) was applied by using Eclipse (Version 11.0, Varian, Palo Alto, USA). 1 Arc, 2 Arc VMAT plans and 7-field IMRT plan were devised for each patient and same values were applied for dose volume constraint and plan normalization. To evaluate these plans, PTV coverage, conformity index (CI) and homogeneity index (HI) were compared and $R_{50%}$ was calculated to assess low dose spillage as per treatment plan. $D_{25%}$ of rectum and bladder Dmean were compared on OAR. And to evaluate the treatment efficiency, total monitor units(MU) and delivery time were considered. Each assessed result was analyzed by average value of 10 patients. Additionally, portal dosimetry was carried out for accuracy verification of beam delivery. Results : There was no significant difference on PTV coverage and HI among 3 plans. Especially CI and $R_{50%}$ on 7F-IMRT were the highest as 1.230, 3.991 respectively(p=0.00). Rectum $D_{25%}$ was similar between 1A-VMAT and 2A-VMAT. But approximately 7% higher value was observed on 7F-IMRT compare to the others(p=0.02) and bladder Dmean were similar among the all plan(P>0.05). Total MU were 494.7, 479.7, 757.9 respectively(P=0.00) for 1A-VMAT, 2A-VMAT, 7F-IMRT and at the most on 7F-IMRT. The delivery time were 65.2sec, 133.1sec, 145.5sec respectively(p=0.00). The obvious shortest time was observed on 1A-VMAT. All plans indicated over 99.5%(p=0.00) of gamma pass rate (2 mm, 2%) in portal dosimetry quality assurance. Conclusion : As a result of study, postoperative prostate cancer radiation therapy for patient using a rectal balloon, there was no significant difference of PTV coverage but 1A-VMAT and 2A-VMAT were more efficient for dose reduction of normal tissue and OARs. Between VMAT plans. $R_{50%}$ and MU were little lower in 2A-VMAT but 1A-VMAT has the shortest delivery time. So it is regarded to be an effective plan and it can reduce intra-fractional motion of patient also.

• Progress in Medical Physics
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• v.25 no.2
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• pp.100-109
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• 2014

In stereotactic body radiotherapy (SBRT), the accurate location of treatment sites should be guaranteed from the respiratory motions of patients. Lots of studies on this topic have been conducted. In this letter, a new verification method simulating the real respiratory motion of heterogenous treatment regions was proposed to investigate the accuracy of lung SBRT for Volumetric Modulated Arc Therapy. Based on the CT images of lung cancer patients, lung phantoms were fabricated to equip in $QUASAR^{TM}$ respiratory moving phantom using 3D printer. The phantom was bisected in order to measure 2D dose distributions by the insertion of EBT3 film. To ensure the dose calculation accuracy in heterogeneous condition, The homogeneous plastic phantom were also utilized. Two dose algorithms; Analytical Anisotropic Algorithm (AAA) and AcurosXB (AXB) were applied in plan dose calculation processes. In order to evaluate the accuracy of treatments under respiratory motion, we analyzed the gamma index between the plan dose and film dose measured under various moving conditions; static and moving target with or without gating. The CT number of GTV region was 78 HU for real patient and 92 HU for the homemade lung phantom. The gamma pass rates with 3%/3 mm criteria between the plan dose calculated by AAA algorithm and the film doses measured in heterogeneous lung phantom under gated and no gated beam delivery with respiratory motion were 88% and 78%. In static case, 95% of gamma pass rate was presented. In the all cases of homogeneous phantom, the gamma pass rates were more than 99%. Applied AcurosXB algorithm, for heterogeneous phantom, more than 98% and for homogeneous phantom, more than 99% of gamma pass rates were achieved. Since the respiratory amplitude was relatively small and the breath pattern had the longer exhale phase than inhale, the gamma pass rates in 3%/3 mm criteria didn't make any significant difference for various motion conditions. In this study, the new phantom model of 4D dose distribution verification using patient-specific lung phantoms moving in real breathing patterns was successfully implemented. It was also evaluated that the model provides the capability to verify dose distributions delivered in the more realistic condition and also the accuracy of dose calculation.

• Progress in Medical Physics
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• v.21 no.3
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• pp.253-260
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• 2010

Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each $^{192}Ir$ source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was $2{\times}2{\times}2\;mm^3$. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.

• Progress in Medical Physics
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• v.25 no.4
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• pp.233-241
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• 2014

The aim of this study is to develop a new software tool for 3D dose verification using $PRESAGE^{REU}$ Gel dosimeter. The tool included following functions: importing 3D doses from treatment planning systems (TPS), importing 3D optical density (OD), converting ODs to doses, 3D registration between two volumetric data by translational and rotational transformations, and evaluation with 3D gamma index. To acquire correlation between ODs and doses, CT images of a $PRESAGE^{REU}$ Gel with cylindrical shape was acquired, and a volumetric modulated arc therapy (VMAT) plan was designed to give radiation doses from 1 Gy to 6 Gy to six disk-shaped virtual targets along z-axis. After the VMAT plan was delivered to the targets, 3D OD data were reconstructed from 512 projection data from $Vista^{TM}$ optical CT scanner (Modus Medical Devices Inc, Canada) per every 2 hours after irradiation. A curve for converting ODs to doses was derived by comparing TPS dose profile to OD profile along z-axis, and the 3D OD data were converted to the absorbed doses using the curve. Supra-linearity was observed between doses and ODs, and the ODs were decayed about 60% per 24 hours depending on their magnitudes. Measured doses from the $PRESAGE^{REU}$ Gel were well agreed with the TPS doses at central region, but large under-doses were observed at peripheral region at the cylindrical geometry. Gamma passing rate for 3D doses was 70.36% under the gamma criteria of 3% of dose difference and 3 mm of distance to agreement. The low passing rate was resulted from the mismatching of the refractive index between the PRESAGE gel and oil bath in the optical CT scanner. In conclusion, the developed software was useful for 3D dose verification from PRESAGE gel dosimetry, but further improvement of the Gel dosimetry system were required.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.577-582
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• 2021

This study was conducted to find ways to restore the domestic medical tourism industry, which was seriously hit by a sharp drop in foreign patients after the COVID-19 Pandemic. Kendall's W verification was used by asking expert panel for keyword advice by ranking. The conclusion of the study is that institutions attracting foreign patients need an opportunity to turn the crisis situation into an opportunity by expanding treatment for severe foreign patients. In addition, it is possible to gain familiarity and trust in hospitals in situations where it is difficult to visit overseas through virtual and augmented reality, and to prevent the risk of infection and protect patients in the untact era. In addition, the blockchain can maintain patient information supplementation, share it safely, minimize customer inconvenience by using payment means using virtual currency, and finally, smart healthcare can manage and provide information to patients regardless of location.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.75-81
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• 2019

Purpose: Helmet type bolus for 3D printer is being manufactured because of the disadvantages of Bolus materials when photon beam is used for the treatment of scalp malignancy. However, PLA, which is a used material, has a higher density than a tissue equivalent material and inconveniences occur when the patient wears PLA. In this study, we try to treat malignant scalp tumors by using M3 wax helmet with 3D printer. Methods and materials: For the modeling of the helmet type M3 wax, the head phantom was photographed by CT, which was acquired with a DICOM file. The part for helmet on the scalp was made with Helmet contour. The M3 Wax helmet was made by dissolving paraffin wax, mixing magnesium oxide and calcium carbonate, solidifying it in a PLA 3D helmet, and then eliminated PLA 3D Helmet of the surface. The treatment plan was based on Intensity-Modulated Radiation Therapy (IMRT) of 10 Portals, and the therapeutic dose was 200 cGy, using Analytical Anisotropic Algorithm (AAA) of Eclipse. Then, the dose was verified by using EBT3 film and Mosfet (Metal Oxide Semiconductor Field Effect Transistor: USA), and the IMRT plan was measured 3 times in 3 parts by reproducing the phantom of the head human model under the same condition with the CT simulation room. Results: The Hounsfield unit (HU) of the bolus measured by CT was $52{\pm}37.1$. The dose of TPS was 186.6 cGy, 193.2 cGy and 190.6 cGy at the M3 Wax bolus measurement points of A, B and C, and the dose measured three times at Mostet was $179.66{\pm}2.62cGy$, $184.33{\pm}1.24cGy$ and $195.33{\pm}1.69cGy$. And the error rates were -3.71 %, -4.59 %, and 2.48 %. The dose measured with EBT3 film was $182.00{\pm}1.63cGy$, $193.66{\pm}2.05cGy$ and $196{\pm}2.16cGy$. The error rates were -2.46 %, 0.23 % and 2.83 %. Conclusions: The thickness of the M3 wax bolus was 2 cm, which could help the treatment plan to be established by easily lowering the dose of the brain part. The maximum error rate of the scalp surface dose was measured within 5 % and generally within 3 %, even in the A, B, C measurements of dosimeters of EBT3 film and Mosfet in the treatment dose verification. The making period of M3 wax bolus is shorter, cheaper than that of 3D printer, can be reused and is very useful for the treatment of scalp malignancies as human tissue equivalent material. Therefore, we think that the use of casting type M3 wax bolus, which will complement the making period and cost of high capacity Bolus and Compensator in 3D printer, will increase later.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.2
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• pp.111-125
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• 2020

In the rapidly changing era of the Fourth Industrial Revolution, the business environment surrounding venture companies is also changing rapidly. In recent years, the government has reorganized the venture verification system, including expanding the types and scope of venture companies. This study analyzes the current status of venture preferential system from the perspective of technology-based start-up companies and in addition, this paper proposes a plan for improving the legal system. For analysis, The relevant provisions were confirmed through a search using "venture" as a keyword in the National Legal Information Center and the Korean Court of General Law. Then, meaningful texts were extracted along with relevant data to secure basic data and analyzed by benefits, by means and by content. As a result of the study, Venture preferential treatment system is focused on 'reduction of burden' by the means of benefits, and on 'financial' and 'production' by benefits. In conclusion, four suggestions for improvement are presented. First, efforts are needed to increase the practical applicability of venture-related clauses. Second, the venture preferential treatment system is mainly focused on mitigating the burden, so efforts are needed to find a balance. Third, the venture preferential treatment system is mainly focused on the 'non-research' field, so the benefits of the 'research' field should be expanded. Finally, efforts to discover and overcome blind spots in the venture preferential system should be supported.

• Korean Journal of Clinical Pharmacy
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• v.22 no.3
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• pp.239-250
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• 2012

In recent years, national health insurance(NHI) coverage had been expanded gradually for cancer as a severe disease requiring high level of medical expenditure, to reduce patient's financial burden. But, subjective burdens level for out-of-pocket(OOP) money expense are still considerable owing to high medical cost and decent numbers of services not covered by benefit plan. This study aimed to investigate OOP medical expenditures and identify factors influencing subjective financial burden in cancer patients. A 28-items questionnaire for self-reporting by responders was designed to satisfy study goal and finalized following by one pilot study and experts' verification process. Subjects were enrolled during July to October 2010 through regular meetings organized by five patient or patient-advocacy groups had acknowledged the study purpose. Subjects who aged 20 or more, have histories of cancer diagnosis and anticancer drug use, and voluntarily agreed to participate in this study were recruited. Total 107 subjects included in the analysis have cancer lesions in breast, colon, kidney, liver or stomach at the stages from I to IV. Approximately 73% of them has passed less than 5 years since cancer diagnosis. For the OOP medical expenditure regarding cancer, less 6 million won was in 31%, 6-15 million won in 35% and more than 15 million won in 28% of responders, and more than half responders(58%) felt financial burden subjectively. 63% of responders had subscribed commercial insurances, resulting in money receipts of more than 10 million won since cancer diagnoses in 76% of responders. Logistic regression results showed significant differences in subjective OOP financial burden level depending on gender, household income level, benefit type, commercial insurance money receipt degree, year cancer diagnosed, cancer lesion, therapy type, duration of anticancer drug use, drug listing in national formulary, total OOP medical expenditure and total OOP anticancer drug expense. They had mixed feelings both wishes to expand NHI coverage to reduce financial burden(70%) and no willingness to increase premium(59%). This result suggested that NHI might direct future strategies to reduce absolute total OOP medical cost and expand benefit plan coverage in higher burden groups in particular.

• The Journal of Korean Academic Society of Nursing Education
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• v.4 no.1
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• pp.66-80
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• 1998

With the opening of healthcare market, the health care environment in Korea is anticipating a drastic change. In this Internationally open market environment, it is necessary to introduce a systematic health care plan and DRG system which offer qualitative medical services as well as reduced cost. Purpose of this study is to develop and test the critical pathway for Cesarean section patient in the way to be possible the integrated inpatient management. It was adopted the process of six phases to develop the critical pathway as the theoretical framework implemented by Johns Hopkins Hospital, Maryland, U.S.A. In the first phase, make a selection of diagnosis/procedures to develop. In the second phase, organize a development team consisted of eight expertises working in maternity nursing area. In the third phase, analyze the overall medical service offered to patient through review medical records and decided the service content and the implementation period for the Cesarean section patient. In the forth phase, make out a preliminary critical pathway after verification of expert group on content validity. In the fifth phase, validity operate to ten Cesarean section patients to test implementation in practice by using the preliminary critical pathway, In the sixth phase, defined the final critical pathway. The result of this study was as follows. 1. There were classified 8 categories as monitoring/assesment, treatment, medication, activity, diet, test, consult, education/discharge plan for vertical axis and showed hospital stayed from admission to discharge for horizontal axis of critical pathway through analysis 68 Cesarean section patients medical records. 2. After critical review 68 medical records to make out a preliminary critical pathway, hospital stays for horizontal axis were showed 6 days, mean hospital stays were 7.5 days, 2.1 days were to be taken operation after admission and 4.2 days were stayed until discharge after operation. 3. After making out a questionare in 90 items of a medical service content of eight categories and verifying the content validity of expertises, the 85 items of the preliminary critical pathway were selected by expertises agreement over 88% and modified or deleted 5 items showing agreement below 75%. 4. After verifying a validity to 10 patients for 4 weeks, hospital stays were 5.9 days. There were deleted 1 item and modified or supplemented the 9 items of the 10 items.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.313-321
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• 2015

To minimize CT examination for Hip FAI diagnosis and operation plan. also, whether the MRI 3D images can replace Hip Clock face image was evaluated when performing Hip FAI MRI by using additional 3D image. This study analyzed Hip MRI and 3D Hip CT images of 31 patients in this hospital. For the purpose of evaluating the images, one orthopedic surgeon and one radiology specialist reconstructed Clock face, at MR and CT modality, by superior 12 o'clock, labrum front 3 o'clock, and the other side 9 o'clock, centering on Hip joint articular transverse ligament 6 o'clock. Afterwards, by the Likert Scale 5 point scale (independent t-test p<0.005), this study evaluated the check-up of A. retinacular vessel, B. head neck junction at 11 o'clock, A. Epiphyseal line, B. Cam lesion at 12 o'clock, and Cam lesion, Posterior Cam lesion at 1,2,3 and 4 o'clock. As for the verification of reliability among observers, this study verified coincidence by Cohen's weighted Kappa verification. As a result of Likert scale for the purpose of qualitative evaluation about the image, 11 o'clock A. retinacular vessel MR average was $3.69{\pm}1.0$ and CT average was $2.8{\pm}0.78$. B. head neck juncton didn't have a difference between two observers (p <0.416). 12 o'clock A. Epiphyseal line MR average was $3.54{\pm}1.00$ and CT average was $4.5{\pm}0.62$(p<0.000). B. Cam lesion didn't have a difference between two observers (p <0.532). 1,2,3,4 Cam lesion and Posterior Cam lesion were not statistically significant (p <0.656, p <0.658). As a result of weighted Kappa verification, 11 o'clock A.retinacular vessel CT K value was 0.663 and the lowest conformity. As a result of coincidence evaluation on respective item, a very high result was drawn, and two observers showed high reliability.