• Progress in Medical Physics
• /
• v.2 no.2
• /
• pp.109-120
• /
• 1991

Total body irradiation is operated to irradicate malignant cells of bone marrow of patients to be treated with bone marrow transplantation. Field size of a linear accelerator or cobalt teletherapy unit with normal geometry for routine technique is too small to cover whole body of a patient. So, any special method to cover patient whole body must be developed. Because such environments as room conditions and machine design are not universal, some characteristic method of TBI for each hospital could be developed. At Seoul National University Hospital, at present, only a cobalt unit is available for TBI because source head of the unit could be tilted. When the head is tilted outward by 90$^{\circ}$, beam direction is horizontal and perpendicular to opposite wall. Then, the distance from cobalt source to the wall was 319 cm. Provided that the distance from the wall to midsagittal plane of a patient is 40cm, nominal field size at the plane(SCD 279cm) is 122cm$\times$122cm but field size by measurement of exposure profile was 130cm$\times$129cm and vertical profile was not symmetric. That field size is large enough to cover total body of a patient when he rests on a couch in a squatting posture. Assuming that average lateral width of patients is 30cm, percent depth dose for SSD 264cm and nominal field size 115.5cm$\times$115.5cm was measured with a plane-parallel chamber in a polystyrene phantom and was linear over depth range 10～20cm. An anthropomorphic phantom of size 25cm wide and 30cm deep. Depth of dose maximum, surface dose and depth of 50% dose were 0.3cm, 82% and 16.9cm, respectively. A dose profile on beam axis for two opposing beams was uniform within 10% for mid-depth dose. Tissue phantom ratio with reference depth 15cm for maximum field size at SCD 279cm was measured in a small polystyrene phantom and was linear over depth range 10～20cm. An anthropomorphic phantom with TLD chips inserted in holes on the largest coronal plane was bilaterally irradiated by 15 minute in each direction by cobalt beam aixs in line with the cross line of the coronal plane and contact surface of sections No. 27 and 28. When doses were normalized with dose at mid-depth on beam axis, doses in head/neck, abdomen and lower lung region were close to reference dose within $\pm$ 10% but doses in upper lung, shoulder and pelvis region were lower than 10% from reference dose. Particulaly, doses in shoulder region were lower than 30%. On this result, the conclusion such that under a geometric condition for TBI with cobalt beam as SNUH radiotherapy departement, compensators for head/neck and lung shielding are not required but boost irradiation to shoulder is required could be induced.

• Journal of Korean Medical classics
• /
• v.12 no.1
• /
• pp.226-254
• /
• 1999

For the first time, the theory of ChonKwanChuk(寸關尺) and the examination method of KyungJung(輕重法) of KiGu(氣口) were formed in "NanKyung(難經)". After that, the vicera assignment theory at left and right hands(左右守藏府記屬理論) was established in "MaekKyung(脈經)" After Reserching the theoretical relevance of the two books, theories between the doctors who understood the examination method of ChukBu(尺部診法) of "Somun MaekYoJungMiRon(素問 脈要精微論)" as the examination method of KyungJung(輕重法) and the doctors who understood that method as the method of ChonKwanChuk(寸關尺) were compared and researched. The results were as follows : 1. The posit ion of ChonKwanChuk(寸關尺) of the examination method of ChonKwanChuk(寸關尺法) is explained at 2nd Nan(二難) of "NanKyung" as follows. Chuk(尺) is the position which is 1Chon(1寸, unit) distant from Kwan(關) to the direction of ChukTaek acupuncture point(尺澤穴) and Chon(寸) is the position which is 9Pun(9分, unit) distant from Kwan(關) to the direction of EoJe acupuncture point(魚際穴). And the six vessels(六經) were assined to ChonKwanChuk(寸關尺) on the basis of OHangJaMoSnagSaeng(五行子母相生) at 18th Nan(18難) of NanKyung. After that Yang Hyun-Jo(楊玄操) at Dang Dynasty, Jung Deok-Yong(丁德用), Woo Seo(廬庶) at Song dynasty explaind the examination method of ChonKwanChuk(寸關尺法) of NanKyung as the method of ChonKwanChuk of two hands(兩手寸關尺法) from the viewpoint of "MaekKyung(脈經)". 2. From the viewpoint of MaeKyung, the vicera assignment of the two hand ChonKwanChuk method is as follows. At Chuk of left hand, the Heart and Small intestine are assigned. At Kwan of left hand, the Liver and Gall Bladder are assigned. At Chuk of left hand, the Kidney and Bladder are assigned. At Chuk of right hand, the Lung and Large in testine are assigned. At Kwan of right hand, the Spleen and Stomach are assigned. At Chuk of Right hand, the Vital Gate(命門) and Bladder are assigned. 3. For the first time, HwalSu(滑壽) at Won dynasty said that the paragraph "尺內兩傍${\cdots}{\cdots}$" of "Somun MaekYoJungMiRon" is the first of the examination method of KiGu(氣口診脈法). After that Ma Shi(馬蒔), Jang Gae-Bin(張介賓) of Myung Dynasty, Jang Ji-Chong(張志聰), Seo Dae-Chun(徐大椿) of Chung Dynasty who were influenced by him explained that paragraph as the method of KiGuChonKwanChuk(氣口寸關尺法). 4. Lee Kyu-Jun(李圭晙) explained the paragraph "尺內兩傍${\cdots}{\cdots}$" of "Somun MaekYoJungMiRon" as the method of KyungJung(輕重法) and explained Chok(尺) as the paragraph 'Chuk is low position of Kigu, and it means the depth(氣口之下位也, 言其深也)' and explained that 'the Left and the Right is layers(左右者層數). And he revised that the Jang(臟) must be examined at the inner part and the Bu(府) must be examined at the outer part. By this, he settled the theoratical basis of the method of KyungJung(輕重法). 5. The doctors who used the examination method of ChonKwanChok(寸關尺診法) settled their logical justification of the two hand examination method of ChonKwanChuk(兩手寸關尺診法) by connecting with "Somon MaekYoJungMi-Ron" from the viewpoint of 2nd Nan(難) and 18th Nan(難) of NanKyung and MaekKyung. On the contrary, the doctors who used the examination method of KyungJung(輕重診法) settled their logical justification of the examination method of KyungJung(輕重診法) by connecting with "Somun MaekYoJungMiRon" from the viewpoint of 4th Nan(四難) and 5th Nan(五難).

• Journal of radiological science and technology
• /
• v.39 no.2
• /
• pp.171-176
• /
• 2016

The quality assurance (QA) is very important for diagnostic field and radiation therapy field to evaluate the characteristic of devices. The purpose of this study was to compare different NPS methodologies results which are measuring NPS with regard to horizontal and vertical directions by using megavoltage X-ray energies. The NPS evaluation methods were applied to the International Electro-technical Commission standard (IEC 62220-1). The electronic portal imaging devices (EPID) devices such as Siemens BEAMVIEW$^{PLUS}$, Elekta iViewGT and Varian Clinac$^R$ iX aS1000 were used. NPS data were expressed by corresponding each frequency about average of noise value corresponding the each frequency, and NPS were evaluated quantitatively by totaling up the noise values of average frequency which are on horizontal and vertical directions. In NPS results for Elekta iViewGT, NPS of horizontal and vertical by using 4 methods were indicated the difference of 3~5% between horizontal and vertical direction. In the results of Siemens BEAMVIEW$^{PLUS}$ and Varian Clinac$^R$ iX aS1000, the NPS of horizontal and vertical direction were indicated the difference of 15% when averaging the whole values. This study were evaluated the NPS of each devices by totaling up the noise values of average frequency which are on horizontal and vertical directions suggesting the quantitative evaluation method using the data.

• Progress in Medical Physics
• /
• v.15 no.1
• /
• pp.30-38
• /
• 2004

Purpose: To develop a whole body frame for the purpose of reducing patient motion and minimizing setup error for extra-cranial stereotactic radiotherapy, and to evaluate the repositioning setup error of a patient in the frame. Materials and Methods: The developed whole body frame is composed of a base plate, immobilizer, vacuum cushion, ruler and belts. The dimension of the base plate is 130 cm in length, 50 cm in width and 1 cm in thickness. The material used in the base plate of the frame was bakelite and the immobilizer was made of acetal. In addition, Radiopaque angio-catheter wires were engraved on the base plate for a coordinate system to determine the target localization. The measurement for radiation transmission and target localization is peformed in order to test the utilization of the frame. Also, a Matlab program analyzed the patients setup error by using the patient's setup images obtained from a CCTV camera and digital record recorder (DVR). Results: A frame that is useful for CT simulation and radiation treatment was fabricated. The frame structure was designed to minimize collisions from the changes in the rotation angle of the gantry and to maximize the transmission rate of the Incident radiation at the lateral or posterior oblique direction. The lightening belts may be used for the further reduction of the patient motion, and the belts can be adjusted so that they are not in the way of beam direction. The radiation transmission rates of this frame were measured as 95% and 96% at 10 and 21 MV, respectively. The position of a test target on the skin of a volunteer is accurately determined by CT simulation using the coordinate system in the frame. The estimated setup errors by Matlab program are shown 3.69$\pm$1.60, 2.14$\pm$0.78 mm at the lateral and central chest, and 7.11 $\pm$2.10, 6.54$\pm$2.22 mm at lateral and central abdomen, respectively. The setup error due to the lateral motion of breast is shown as 6.33$\pm$ 1.55 mm. Conclusion: The development and test of a whole body frame has proven very useful and practical in the radiosurgery for extra-cranial cancers. It may be used in determining target localization, and it can be used as a patient immobilization tool. More experimental data should be obtained in order to improve and confirm the results of the patient setup error.

• Progress in Medical Physics
• /
• v.10 no.1
• /
• pp.1-7
• /
• 1999

In this study, the dose distributions of a $^{32}$ p uniform cylindrical volume source and a surface source, a pure $\beta$emitter, were calculated in order to obtain information relevant to the utilization of a balloon catheter and a radioactive stent. The dose distributions of $^{32}$ p were calculated by means of the EGS4 code system. The sources are considered to be distributed uniformly in the volume and on the surface in the form of a cylinder with a radius of 1.5 mm and length of 20 mm. The energy of $\beta$particles emitted is chosen at random in the $\beta$ energy spectrum evaluated by the solution of the Dirac equation for the Coulomb potential. Liquid water is used to simulate the particle transport in the human body. The dose rates in a target at a 0.5mm radial distance from the surface of cylindrical volume and surface source are 12.133 cGy/s per GBq (0.449 cGy/s per mCi, uncertainty: 1.51%) and 24.732 cGy/s per GBq (0.915 cGy/s per mCi, uncertainty: 1.01%), respectively. The dose rates in the two sources decrease with distance in both radial and axial direction. On the basis of the above results, the determined initial activities were 29.69 mCi and 1.2278 $\mu$Ci for the balloon catheter and the radioactive stent using $^{32}$ P isotope, respectively. The total absorbed dose for optimal therapeutic regimen is considered to be 20 Gy and the treatment time in the case of the balloon catheter is less than 3 min. Absorbed doses in targets placed in a radial direction for the two sources were also calculated when it expressed initial activity in a 1 mCi/ml volume activity density for the cylindrical volume source and a 0.1 mCi/cm$^2$ area activity density for the surface source. The absorbed dose distribution around the $^{32}$ P cylindrical source with different size can be easily calculated using our results when the volume activity density and area activity density for the source are known.

• Progress in Medical Physics
• /
• v.22 no.1
• /
• pp.35-41
• /
• 2011

For overall system test, hidden-target test have been used using film which leads to inherent analysis error. The purpose of our study is to quantify this error and to propose gel dosimeter based verification technique for 3-dimensional target point error. The phantom was made for simulation of human head and this has ability to equip 10 gel-dosimeter. $BANGkit^{TM}$ which we are able to manufacture whenever it is needed as well as to easily change the container with different shapes was used as a gel dosimeter. The 10 targets were divided into two groups based on shapes of areas with a planned 50% isodose line. All treatment and analysis was performed three times using Novalis and $BrainSCAN^{TM}$. The target point error is $0.77{\pm}0.15mm$ for 10 targets and directional target point error in each direction is $0.54{\pm}0.23mm$, $0.37{\pm}0.08mm$, $0.33{\pm}0.10mm$ in AP (anterior-posterior), LAT (lateral), and VERT (vertical) direction, respectively. The result of less than 1 mm shows that the treatment was performed through each precise step in treatment procedure. In conclusion, the 3-dimensional target point verification technique can be one of the techniques for overall system test.

• Progress in Medical Physics
• /
• v.21 no.2
• /
• pp.174-182
• /
• 2010

In this study, we evaluated feasibility of applying MTV (Metabolic Target Volume) to respiratory gated radiotherapy for more accurate treatment using various SUV (Standard Uptake Value) from PET images. We compared VOI (Volume of Interest) images from 50%, 30% and 5% SUV (standard uptake volume) from PET scan of an artificial target with GTV (Gross Tumor Volume) images defined by percentage of respiratory phase from 4D-CT scan for respiratory gated radiotherapy. It is found that the difference of VOI of 30% SUV is reduced noticeably comparing with that of 50% SUV in longitudinal direction with respect to total GTV of 4D-CT image. Difference of VOI of 30% SUV from 4D-PET image defined by respiratory phase from 25% inhalation to 25% exhalation, and GTV from 4D-CT with the same phase is shown below 0.6 cm in maximum. Thus, it is better to use 4D-PET images than conventional PET images for applying MTV to gated RT. From the result that VOI of 5% SUV from 4D-PET agrees well with reference image of 4D-CT in all direction, and the recommendation from department of nuclear medicine that 30% SUV be advised for defining tumor range, it is found that using less than 30%SUV will be more accurate and practical to apply MTV for respiratory gated radiotherapy.

• The Journal of Korean Society for Radiation Therapy
• /
• v.35
• /
• pp.7-13
• /
• 2023

Purpose: In this study, we evaluated the effect of using a customized bolus on dose delivery in the treatment plan when cervical cancer protruded out of the body along with the uterus and evaluated reproducibility in patient set-up. Materials & Methods: The treatment plan used the Eclipse Treatment Planning System (Version 15.5.0, Varian, USA) and the treatment machine was VitalBeam (Varian Medical Systems, USA). The radiotherapy technique used 6 MV energy in the AP/PA direction with 3D-CRT. The prescribed dose is 1.8 Gy/fx and the total dose is 50.4 Gy/28 fx. Semiflex TM31010 (PTW, Germany) was used as the ion chamber, and the dose distribution was analyzed and evaluated by comparing the planned and measured dose according to each position movement and the tumor center dose. The first measurement was performed at the center by applying a customized bolus to the phantom, and the measurement was performed while moving in the range of -2 cm to +2 cm in the X, Y, and Z directions from the center assuming a positional error. It was measured at intervals of 0.5 cm, the Y-axis direction was measured up to ±3 cm, and the situation in which Bolus was set-up incorrectly was also measured. The measured doses were compared based on doses corrected to CT Hounsfield Unit (HU) 240 of silicon instead of the phantom's air cavity. Result: The treatment dose distribution was uniform when the customized bolus was used, and there was no significant difference between the prescribed dose and the actual measured value even when positional errors occurred. It was confirmed that the existing sheet-type bolus is difficult to compensate for irregularly shaped tumors protruding outside the body, but customized Bolus is found to be useful in delivering treatment doses uniformly.

• Journal of Korean Physical Therapy Science
• /
• v.5 no.3
• /
• pp.659-674
• /
• 1998

This Study was to investigate elaborated research themes and direction through specifying the problems of clinical practice education and looking for the direction of improvement. It was in the basis of the viewpoint of the educators that professors and therapists who were the subjects of this study. Perform this study, the 15 colleges' professors and the 55 hospitals' therapists was made up questionnaire, and the data was analysing by Chi-square test and percentage. The results were as follow : ${\cdot}$ In a personal history among the general qualities, professors have little clinical practice history(l-5 years, 53.3%), and therapists have little lecture career(1-5 years, 43.6%, have no 49.0%), ${\cdot}$ The 78.6% subjects were unsatisfied of clinical practice systems. ${\cdot}$ The correlation between clinical history, school career and lecture career and the satisfaction level of clinical practice systems has no(P<.005), ${\cdot}$ The subjects were agreed to that clinical practice curriculum should be changed(67.1%), reinforced(82.9%), and specified(90.0%). ${\cdot}$ The clinical practice credits are 11 points averagely. ${\cdot}$ In the clinical practice curriculum, it made no difference in the practicum of diseases, modality, and the therapeutic techniques between professors and therapists. ${\cdot}$ The 100% professors said that the practicum of the patients' assessment is necessary, and the 63.6% therapists were training for that. ${\cdot}$ The 66.7% professors said that the practicum of the clinical psychology is necessary, and only the 20.0% therapists were training for that. ${\cdot}$ The 93.3% professors said that the practicum of the patients' management is necessary, and the 50.9% therapists were training for that. ${\cdot}$ The 66.7% professors said that the practicum of the medical ethics is necessary, and the 34.5% therapists were training for that. ${\cdot}$ The 46.7% professors said that the practicum of the hospital administration is necessary, but the 54.5% therapists have not training. ${\cdot}$ The 33.3% professors said that the practicum of the pharmacology is necessary, but the 81.8% therapists have not training. ${\cdot}$ The 86.7% professors said that the practicum of the patient's education is necessary, and the 43.6% therapists have training. ${\cdot}$ The 66.7% professors said that the practicum of the prosthesis and brace is necessary, but the 14.5% therapists have not training. ${\cdot}$ The 60.0% professors said that the practicum of the exercise prescription is necessary, but the 25.5% therapists have not training. ${\cdot}$ The 53.5% professors said that the practicum of the emergency treatment is necessary, but the 52.7% therapists have not training. ${\cdot}$ Drawing up the plan about the curriculum of clinical practice, the professors (46.7%) were agreed to national master plan framing by an expert advisor, but the therapists (58.2%) said that the plan that make the most of hospitals' characteristics should be specified. ${\cdot}$ It was found that a clinical special therapists(54.5%) was good as a person in charge of clinical practice education, in that each therapist's own good time (34.5%) was. ${\cdot}$ It made use of the form framing by college(40.0%) as the clinical practice textbook, the form framing by hospital (42.9%) and each therapist(22.9%) as the plan, and the form framing by college (74.3%) as the measurement. ${\cdot}$ The most difficult point in clinical practice education was the lacks of the theory-praciticum linkage(78.2%). ${\cdot}$ It was found that the period of clinical practice was in the second semester-third grade (40.0%) and the desirable period was in the first semester-third grade(50.0%). ${\cdot}$ Professors (53.3%) were agreed that the desirable clinical practice duration was from four months to six months(60.0%), and the therapists (60.0%) were agreed that from one month to three months. ${\cdot}$ This study presented the lacks of rearing the experts, the lacks of cultural education, and the lacks of the theory-clinical practice linkage. There were need to develop the systematic programs, clinical practice textbooks, the measurements and the special hospital for clinical practice. And it was need to reduce the gab between of the hospitals for clinical practice, to cut down the costs. and to improve the labour conditions of leaders. In view of this findings, it takes notice of that both professor and therapist were dissatisfied at the present clinical practice systems. These results point out the problems of clinical practice systems, and do not make expect to us the successive and positive clinical practice. The general, specific and intensive plan about the problems and the direction of improvement that establishing the level of hospital for clinical practice and physiotherapy can be elaborated.

• Journal of radiological science and technology
• /
• v.40 no.4
• /
• pp.549-556
• /
• 2017

This study compared the spatial scattered dose distribution according to whether the recently developed radiation shielding is used or not in order to understand the spatial scattered dose distribution of C-arm. The horizontal side distribution increased by $30^{\circ}$ in the interval of the radius 50 cm on the height of 95 cm based on the head of the patient, and it was measured by increasing $30^{\circ}$ with the interval of 50 cm in the vertical side of each horizontal side. In the same method, the radiation shielding was installed and measured. The result of measurement shows that the horizontal side of 50 cm distance was $0^{\circ}$, $90^{\circ}$ and $180^{\circ}$, was $1.77{\pm}0.12$, $1.90{\pm}0.13$, $2.12{\pm}0.14$, and $2.69{\pm}0.15mSv/h$ in the $270^{\circ}$ direction, and was $1.59{\pm}0.12$, $0.99{\pm}0.09$, $1.47{\pm}0.11$, and $1.37{\pm}0.11mSv/h$ after the use of the radiation shielding. In addition, the vertical distribution in horizontal direction $90^{\circ}$ with 50 cm distance was $30^{\circ}$, $60^{\circ}$, $120^{\circ}$, was $3.85{\pm}0.18$, $9.15{\pm}0.28$, $10.82{\pm}0.31$, and $5.40{\pm}0.22mSv/h$ in $150^{\circ}$, and was $2.03{\pm}0.13$, $4.32{\pm}0.19$, $2.76{\pm}0.16$, and $1.92{\pm}0.13mSv/h\;mR/h$ after the use of the radiation shielding. Both direction showed decrease according to the use of the radiation shielding. Therefore, radiation related workers who work in operating rooms should recognize the spatial scattered dose distribution exactly and need to try to prevent the risk of radiation exposure with proper protective measures.