• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.115-122
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• 2015

Purpose : The aim of this study, evaluate the accuracy of HeaxPOD evo RT system using the non-coplanar beam. Materials and Methods : 13 treatment plans are used which applied non-coplanar beams and 10 treatment plans which coplanar beams are used. the correction value what adjust to 6D couch is determined by each patient's setup errors only rotation direction. The study executed followings. first, Applying the correction value, measure the point dose and calculate the ${\gamma}$-index(${\gamma}=3%$ / 3 mm, ${\gamma}=2%$ / 2 mm). second, acquire data as previous methods without correction by HexaPOD. Results : For comparing the two results, we find out the more precise applying HexaPOD by point dose 0.2% in coplanar and non-coplanar. in the case of ${\gamma}$-index<1(${\gamma}=3%$ / 3 mm), more precise 2.2% in coplanar and 7% in Non-coplanar. Particularly, ${\gamma}$-index<1(2% / 2 mm) show the difference 9.2% in coplanar and 15.1% non-coplanar between apply HexaPOD and dose not apply HexaPOD. Conclusion : Using the HexaPOD is more precise than without HexaPOD. It suggests that HexaPOD evo RT system is very useful for precise and high dose delivery.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.107-113
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• 2015

Purpose : The measurement of skin dose is very important that treatment of breast cancer. On account of the cold or hot dose as compared with prescription dose, it is necessary to analyse the skin dose occurring during the various plan of the breast cancer treatment. At our hospital, we want to apply various analyses using a diversity of dosimeters to the breast cancer treatment. Subjectss and Methods : In the study, the anthropomorphic phantom is used to find out the dose difference of the skin(draining site), scar and others occurring from the tangential treatment plan of breast cancer. We took computed tomography scan of the anthropomorphic phantom and made plans for the treatment planing using open and wedge, Field-in-Field, Dose fluence. Using these, we made a comparative analysis of the dose date points by using the Eclipse. For the dose comparison, we place the anthropomorphic phantom in the treatment room and compared the measurement results by using the TLD and MOSFET on the dose data points. Results : On the central point of treatment planing basis, the upward and downward skin dose measured by the MOSFET was the highest when the fluence was used. The skin dose of inner and outer was distinguished from the figure(5.7% ~ 10.3%) when the measurements were fulfilled by using TLD and MOSFET. The other side of breast dose was the lowest in the open beam, on the other hand, is highest in the Dose fluence plan. In the different kinds of treatment, the dose deviation of inner and outer was the highest, and so this was the same with the TLD and MOSFET measurement case. The outer deviation was highest in the TLD, and the Inner'was highest in the MOSFET. Conclusion : Skin dose in relation to the treatment plan was the highest in the planing using the fluence technique in general and it was supposed that the high dose had been caused by the movement of the MLC. There's some differences among the all the treatment planning, but the sites such as IM node occurring the lack of dose, scar, drain site are needed pay close attention. Using the treatment planning of dose fluence is good to compensate the lack of dose, but It increases the dose of the selective range rather than the overall dose. Therefore, choosing the radiotherapy technique is desirable in the lights of the age and performance of the patient.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.105-111
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• 2005

Purpose : Daily Q.A is the important step which must be preceded in a radiation treatment. Specially, radiation output measurement and laser alignment, SSD indicator related to a patient set-up recurrence must be confirmed for a reasonable radiation treatment. Daily Q.A proceeds correctness and a prompt way, and needs an objective measurement basis. Manufacture of the device which can facilitate confirmation of output measurement and appliances check at one time was requested. Materials and Methods : Produced the phantom formal daily check device which can confirm a lot of appliances check (output measurement and laser alignment. field size, SSD indicator) with one time of set up at a time, and measurement observed a linear accelerator (4 machine) for four months and evaluated efficiency. Results : We were able to confirm an laser alignment, field size, SSD indicator check at the same time, and out put measurement was possible with the same set up, so daily Q.A time was reduced, and we were able to confirm an objective basis about each item measurement. As a result of having measured for four months, output measurement within ${\pm}2%$, and measured laser alignment, field size, SSD indicator in range within ${\pm}1mm$. Conclusion : We can enforce output measurement and appliances check conveniently, and time was reduced and was able to raise efficiency of business. We were able to bring a cost reduction by substitution expensive commercialized equipment. Further It is necessary to makes a product as strong and slight materials, and improve convenience of use.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.73-78
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• 2015

Purpose : Under the assumption of change to the amplitude based sorting, the study will use four dimensional computed tomography imaging (4DCT) arrayed using the phase based sorting to analyze the respiratory phase difference. Materials and Methods : The study analyzed the 4DCT (4-dimensional computed tomography) images of 10 liver cancer patients that were treated with respiratory gated radiotherapy from 2015 February to March. Using RPM respiratory gating (RPM 1.7.5, Varian, USA) equipment, imaging according to respiratory cycle of phase based sorting was acquired and using a treatment planning system (Pinnacle 9.2, Philips, USA) the acquired imaging according to respiratory cycle was used to measure the abdominal movement value by respiratory cycle. The measuring point was the point where the center point of the Marker Block and the body surface met in the 50% phase image and here the coordinate values Lateral, Vertical, Longitudinal (X, Y, Z) were set as reference points, and on the X, Z plane identical to the reference point, using the identical method the Y axis coordinate value of each 0%, 30%, 40%, 50%, 60%, 80% phase images were acquired to quantitatively measure the variation of distance to the Y axis. The abdominal movement value according to respiration was applied to the theoretical model that the value decreases linearly from maximum inhalation to maximum exhalation to divide the variation of my value to predict as amplitude value by respiratory cycle and conversely the variation in amplitude was recalculated with the phase variation deviation value to analyze. Results : The deviation value between expected value and actual location was the largest in the 30% phase with 0.24 cm, and standard deviation was also the largest in 30% phase with 0.13 cm. The effective value of the deviation value derived from the average of the deviation squared value of each patient appeared as minimum 0.7 cm, maximum 0.18 cm, average 0.12 cm, and standard deviation 0.4 cm. Also by dividing the actual movement distance value with the peak expiration value then converting it into %Phase, the deviation value with actual phase 16.5% in 30% phase, 10.0% and 40% phase, 10.0% and 60% phase, 15.4% and 80% phase, and overall average about 13%, and arraying based on amplitude, phase shift occurred and further it was from peak expiration the chance of deviation occurrence was increasingly measured. Conclusion : Based on the results of the study there were differences between value acquired based on theoretical model and actual value. Therefore in respiratory gated radiotherapy using external surrogates, there needs to be establishment of respiration gated radiation system that avoids the combination of two Sorting methods considering that there will be occurrence of treatment and corresponding clinical differences due to the phase difference that occur due to the Amplitude based Phase Sorting.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.13-22
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• 2015

Purpose : We investigated the safety of Intrabeam$^{TM}$ system, X-ray unit for Intraoperative Radiotheray (IORT) by measuring surface dose using Optically Stimulated Luminescent Dosimeter(OSLD). Materials and Methods : 30 patients were selected, who were in breast cancer patients and had an operation of breast conserving surgery (BCS). At the inner surface of tumor bed, 20 Gy were described, and 5 Gy at 1cm depth from the inner surface. Along the size of tumor bed which could be decided after resection of tumor, the size of applicator were determined. Usual treatment time were from 18 to 40 minutes. For the measurement of surface doses, OSLD were placed at superior(U1,2), inferior(D1,2), lateral(L1,2) and medial(M1,2) directions from the center of applicator. Each direction, two OSLD were placed at 0.5 cm and 1.5 cm from the center. Mean, maximum, and minimum doses were analyzed to be compared. Results : Mean values were U1 $2.23{\pm}0.80Gy$, U2 $1.54{\pm}0.53Gy$, D1 $1.73{\pm}0.63Gy$, D2 $1.25{\pm}0.45Gy$, L1 $1.95{\pm}0.82Gy$, L2 $1.38{\pm}0.42Gy$, M1 $2.03{\pm}0.70Gy$, and M2 $1.51{\pm}0.58Gy$. Maximum values were 4.34 Gy at U1, and Minimum values were 0.45 Gy at M2. 13.3 % of patient (4pts out of 30) were reported that surface dose were over 4 Gy. Conclusion : The fact that skin dose of all patients were less than 5 Gy based on OSLD measurement showed the safety of Intrabeam$^{TM}$ system. In the relatively small breast volume, the tendency that surface dose was increased had been shown, which was analyzed by the data of patients who irradiated over 4Gy at skin surface. Therefore, for appropriate indication for IORT, it is suggested that breast volume as well as the size and position of tumor should be carfully considered.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.2
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• pp.13-24
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• 2019

Purpose: CT scan range is insufficient for various reasons in head and neck Tomotherapy^®. To solve that problem, Re-CT simulation is good because CT scan range affects accurate dose calculations, but there are problems such as increased exposure dose, inconvenience, and a change in treatment schedule. We would like to evaluate the minimum CT scan range required by changing the plan setup parameter of the existing CT scan range. Materials and methods: CT Simulator(Discovery CT590 RT, GE, USA) and In House Head & Neck Phantom are used, CT image was acquired by increasing the image range from 0.25cm to 3.0cm at the end of the target. The target and normal organs were registered in the Head & Neck Phantom and the treatment plan was designed using ACCURAY Precision^®. Prescription doses are Daily 2.2Gy, 27 Fxs, Total Dose 59.4Gy. Target is designed to 95%~107% of prescription dose and normal organ dose is designed according to SMC Protocol. Under the same treatment plan conditions, Treatment plans were designed by using five methods(Fixed-1cm, Fixed-2.5cm, Fixed-5cm, Dynamic-2.5cm Dynamic-5cm) and two pitches(0.43, 0.287). The accuracy of dose delivery for each treatment plan was analyzed by using EBT3 film and RIT(Complete Version 6.7, RIT, USA). Results: The accurate treatment plan that satisfying the prescribed dose of Target and the tolerance dose in normal organs(SMC Protocol) require scan range of at least 0.25cm for Fixed-1cm, 0.75cm for Fixed-2.5cm, 1cm for Dynamic-2.5cm, and 1.75cm for Fixed-5cm and Dynamic-5cm. As a result of AnalysisAnalysis by RIT. The accuracy of dose delivery was less than 3% error in the treatment plan that satisfied the SMC Protocol. Conclusion: In case of insufficient CT scan range in head and neck Tomotherapy^®, It was possible to make an accurate treatment plan by adjusting the FW among the setup parameter. If the parameter recommended by this author is applied according to CT scan range and is decide whether to re-CT or not, the efficiency of the task and the exposure dose of the patient are reduced.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.27-34
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• 2003

Purpose : To evaluate the efficacy of radiotherapy, and the factors affecting survival in patients of extrahepatic bile duct cancer, by analyzing the results of postoperative radiotherapy Materials and Methods : Between October 1991 and July 2001, 21 patients with extrahepatic bile duct cancer, who received radiotherapy after a radical resection, were retrospectively reviewed. The patients' ages ranged from 39 to 75 years, with a median of 61 years, and a male to female ratio of 16 to 5. The numbers of patients with proximal and distal bile duct cancer were 14 and 7, respectively. From the postoperative pathological examination, 19 of the patients were found to have microscopic residues, and 7 to be lymph node positive. Patients with AJCC stages I, II and III were 10, 10 and 1, respectively. The total radiation dose administered was 4,500$\~$6,300 cGy, with a median dose of 5,040 cGy. The follow up period was 20$\~$81 months, with a median of 57.5 months. Results : The overall and disease free survival rates at 3 and 5 years were 41.0 and 29.3$\%$, and 41.6 and 29.7$\%$, respectively. The influences of age, sex, tumor location, differentiation, microscopic residue, neural invasion, 7 and N stage, the stage itself, the dose of radiation and chemotherapy, on survival were evaluated. The T stage and the stage itself were found to be significant from a univariate analysis (p<0.05), but the degree of significance was limited by the small number of patients. A recurrence occurred in 12 patients (57.1$\%$), 5 in locoregional sites, 4 in distant sites and 3 in a combination of locoregional and distant sites, and the sites of distant metastasis were the liver, 6, and the bone, 1 Grade 2 or 3 acute leucopenias occurred in 2 patients and grade 2 chronic peptic ulcers occurred in 4, who were all recovered by conservative management. Conclusion : Postoperative radiotherapy is feasigbls in extrah데atic bile duct cancer, with tolerable toxicity, but prospective studies, with a large patient enrollment, are needed for the evaluation of the effects of postoperative radiotherapy and the related prognostic factors.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.94-99
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• 2003

Purpose : To explore a 3D conformal radiotherapy technique for a posterior fossa boost, and the potential advantages of a prone position for such radiotherapy. Materials and Methods :A CT simulator and 3D conformal radiotherapy Planning system was used for the posterior fossa boost treatment on a 13-year-old medulloblastoma patient. He was placed In the prone position and Immobilized with an aquaplast mask and immobilization mold. CT scans were obtained of the brain from the top of the skull to the lower neck, with IV contrast enhancement. The target volume and normal structures were delineated on each slice, with treatment planning peformed using non-coplanar conformal beams. Results : The CT scans, and treatment In the prone position, were peformed successfully. In the prone position, the definition of the target volume was made easier due to the well enhanced tentorium, In audition, the posterior fossa was located anteriorly, and with the greater choice of beam arrangements, more accurate treatment planning was possible as the primary beams were not obstructed by the treatment table. Conclusion : .A posterior fossa boost, in the prone position, Is feasible in cooperating patients, but further evaluation is needed to define the optimal and most comfortable treatment positions.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.205-218
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• 2008

Interaction between pain and sleep has long been proved through many researches, and various studies are being conducted to identify its mechanism. However, these studies have targeted on patients with systemic disease, such as rheumatic disease and fibromyalgia. There are few researches on patients with orofacial pain including temporomandibular disorder(TMD). In this study, we studied interaction between pain aspect and sleep quality in 229 patients with TMD, who visited the TMJ and Orofacial pain clinic. Pittsburgh Sleep Quality Index(PSQI), Epworth sleepiness scale(ESS) questionnaire were surveyed and sleep-screening device was operated. PSQI showed that sleep quality in TMD patients with pain was poorer than that in TMD patients without pain. The ratio of poor sleeper was higher in TMD patients with pain. Especially, TMD patients with chronic pain showed obviously poorer sleep quality than TMD patients with acute pain. The result of ESS showed that patients with painful TMD showed more daytime sleepiness than painless TMD patients. The ratio of TMD patients with chronic pain who had daytime sleepiness was higher than TMD patients with acute pain, and the amount of daytime sleepiness was higher in the group of chronic pain. In TMD patients with chronic pain, only the poor sleeper(PSQI>5) presented mean ESS>10(diagnostic criteria of daytime sleepiness). There was no correlation between pain intensity and sleep quality or daytime sleepiness. The result of ApnealinkTM for screening of sleep related breathing disorder showed that only 1 patient presented AHI>5 among 19 participants. TMD patients with chronic pain presented poor sleep quality and excessive daytime sleepiness similar to other chronic pain patients. Evaluation of sleep state by questionnaire might be useful for diagnosis and management of TMD, because sleep disturbance decreases pain threshold and pain disturbs sleep. In addition, sleep-screening device would be useful for screening sleep related breathing disorder in dental clinic.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.195-204
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• 2008

Osteoarthritis is caused by joint degeneration, a process that includes progressive loss of articular cartilage accompanied by attempted repair of articular cartilage, remodeling and sclerosis of subchondral bone, and osteophyte formation. The most common causative factor that either causes or contributes to osteoarthritis is overloading of the articular structures of the joint. The diagnosis of temporomandibular joint(TMJ) osteoarthritis is based on the patient's history and clinical findings such as limited mandibular opening, crepitation and tenderness to palpation on TMJ. The diagnosis is usually confirmed by TMJ radiographs, which will reveal evidence of structural changes in the subarticular bone of the condyle or fossa. Plain radiography techniques such as panoramic, transcranial, transpharyngeal views can be used in most dental offices for evaluation of the TMJs. However, plain radiographs are often limited due to overlapping and distortion of anatomical structures. The aim of this study was to compare the clinical examination and panoramic view with computed tomography for diagnosis of temporomandibular degenerative joint disease, and to compare the findings of condylar bony changes through panoramic radiography with that of computed tomography, hence, to confirm the limitations of clinical and panoramic radiography, and the validity of the computed tomography for diagnosis of temporomandibular degenerative joint disease. The pathophysiology of the TMJ osteoarthritis remains poorly understood, and current treatments are based more on speculation than science, and symptomatic treatments often fail to provide satisfactory pain relief. For diagnosis of TMJ osteoarthritis, clinical examination and radiographic examination for confirmation of the bony changes are essential, and computed tomography are clearly superior to plain radiographs for their limitations.