• The Journal of Korean Society for Radiation Therapy
• /
• v.21 no.1
• /
• pp.1-7
• /
• 2009

Purpose: The purpose is to evaluate the accuracy of correcting the targeting error through the Target Location System (TLS) for the location change error of the reference point which arises from the movement or motion of patient during the treatment using the CyberKnife. Materials and Methods: In this test, Gafchromic MD-55 film was inserted into the head and neck phantom to analyze the accuracy of the targeting, and then the 6 MV X-ray of CyberKnife (CyberKnife Robotic Radiosurgery System G4, Accuray, US) was irradiated. End to End (E2E) program was used to analyze the accuracy of targeting, which is provided by Accuray Corporation. To compute the error of the targeting, the test was carried out with the films that were irradiated 12 times by maintaining the distance within the rage of $0{\pm}0.2\;mm$ toward x, y, z from the reference point and maintaining the angle within the rage of $0{\pm}0.2^{\circ}$ toward roll, pitch, yaw, and then with the films which were irradiated 6 times by applying intentional movement. And the correlation in the average value of the reference film and the test film were analyzed through independent samples t-test. In addition, the consistency of dose distribution through gamma-index method (dose difference: 3%) was quantified, compared, and analyzed by varying the distance to agreement (DTA) to 1 mm, 1.5 mm, 2 mm, respectively. Results: E2E test result indicated that the average error of the reference film was 0.405 mm and the standard deviation was 0.069 mm. The average error of the test film was 0.413 mm with the standard deviation of 0.121 mm. The result of independent sampling t-test for both averages showed that the significant probability was P=0.836 (confidence level: 95%). Besides, by comparing the consistency of dose distribution of DTA through 1 mm, 1.5 mm, 2 mm, it was found that the average dose distribution of axial film was 95.04%, 97.56%, 98.13%, respectively in 3,314 locations of the reference film, consistent with the average dose distribution of sagittal film that was 95.47%, 97.68%, 98.47%, respectively. By comparing with the test film, it was found that the average dose distribution of axial film was 96.38%, 97.57%, 98.04%, respectively, at 3,323 locations, consistent with the average dose distribution of sagittal film which was 95.50%, 97.87%, 98.36%, respectively. Conclusion: Robotic CyberKnife traces and complements in real time the error in the location change of the reference point caused by the motion or movement of patient during the treatment and provides the accuracy with the consistency of over 95% dose distribution and the targeting error below 1 mm.

• The Journal of Korean Society for Radiation Therapy
• /
• v.26 no.1
• /
• pp.11-19
• /
• 2014

Purpose : To derive the most appropriate factors by considering the effects of the major factors when applied to the optimization algorithm, thereby aiding the effective designing of a ideal treatment plan. Materials and Methods : The eclipse treatment planning system(Eclipse 10.0, Varian, USA) was used in this study. The PBC (Pencil Beam Convolution) algorithm was used for dose calculation, and the DVO (Dose Volume Optimizer 10.0.28) Optimization algorithm was used for intensity modulated radiation therapy. The experimental group consists of patients receiving intensity modulated radiation therapy for the head and neck cancer and dose prescription to two planned target volume was 2.2 Gy and 2.0 Gy simultaneously. Treatment plan was done with inverse dose calculation methods utilizing 6 MV beam and 7 fields. The optimal algorithm parameter of the established plan was selected based on volume dose-priority(Constrain), dose fluence smooth value and the impact of the treatment plan was analyzed according to the variation of each factors. Volume dose-priority determines the reference conditions and the optimization process was carried out under the condition using same ratio, but different absolute values. We evaluated the surrounding normal organs of treatment volume according to the changing conditions of the absolute values of the volume dose-priority. Dose fluence smooth value was applied by simply changing the reference conditions (absolute value) and by changing the related volume dose-priority. The treatment plan was evaluated using Conformal Index, Paddick's Conformal Index, Homogeneity Index and the average dose of each organs. Results : When the volume dose-priority values were directly proportioned by changing the absolute values, the CI values were found to be different. However PCI was $1.299{\pm}0.006$ and HI was $1.095{\pm}0.004$ while D5%/D95% was $1.090{\pm}1.011$. The impact on the prescribed dose were similar. The average dose of parotid gland decreased to 67.4, 50.3, 51.2, 47.1 Gy when the absolute values of the volume dose-priority increased by 40,60,70,90. When the dose smooth strength from each treatment plan was increased, PCI value increased to $1.338{\pm}0.006$. Conclusion : The optimization algorithm was more influenced by the ratio of each condition than the absolute value of volume dose-priority. If the same ratio was maintained, similar treatment plan was established even if the absolute values were different. Volume dose-priority of the treatment volume should be more than 50% of the normal organ volume dose-priority in order to achieve a successful treatment plan. Dose fluence smooth value should increase or decrease proportional to the volume dose-priority. Volume dose-priority is not enough to satisfy the conditions when the absolute value are applied solely.

• Radiation Oncology Journal
• /
• v.23 no.2
• /
• pp.123-130
• /
• 2005

Purpose: We wanted to improve the setup reproducibility of breast cancer patients when utilizing a commercially available breast board for radiation therapy. The breast board was modified by using a new head rest and 2 types of board fixation devices. Materials and Methods: A conventional head/neck rest was modified to be positioned in various slots of the breast board, and it was fabricated 1 cm thinner to provide more comfort to a patient when the patient's neck was rotated. This rest improves the uncertainty of the daily setup. Also, the sagging problems at the left and right sides became negligible with the two types of board fixation devices: (1) the stair type, and (2) the arm type. The first device consists of an upper/lower holder with 4 stair-types of grooves and 4 rectangular Inserts. In order to cover the whole range of vertical setup of the breast board, 4 rectangular inserts were needed, and each covered 10 steps. The arm-type fixation device was also fabricated and attached to the breast board, It had two aluminum bars that were fixed by utilizing a lock-type of screw. These devises were evaluated with two volunteers in order to prove the effectiveness of the improved setup accuracy. Results; The developed cranio-caudal fixation device demonstrated that it could reduce the cranio-caudal error by nearly $55\%$ compared to the old device. As for left-and-right inclination, the stair-type and arm-type fixation devices can reduce the relative inclination by nearly $80\%$ and $90\%$, respectively, compared to the breast board without the fixation device. Conclusion: It was verified that the developed devices were effective for positioning the patients and for avoiding inclination of the breast board.

• Journal of Oral Medicine and Pain
• /
• v.19 no.2
• /
• pp.81-97
• /
• 1994

두개하악장애는 환자의 신체적 소인, 관련조직의 구조적 변화, 정신적 스트레스 등의 복합적 요인에 의 발생하는 다인성 질환으로 최근 대두되는 원인중의 하나가 신체, 특히 두경부의 자세이상이다. 비정상적인 두경부자세는 하악의 위치변화를 수반하여 종종 두개하악장애를 야기시키게 되나 이를 설명할 수 있는 과학적 증거는 아직 부족한 실정이다. 저자는 두경부 자세가 교합장치물에 의해 변화되는지를 저작근의 근전도학적 측면에서 규명하고자 21세에서 26세의 치과대학생으로 치아상실 및 교합간섭이 없고 두 개하악장애의 증후 및 경부운동제한을 가지지 않은 정상인 20명을 대상으로 각도계를 사용하여 시상면상에서 인위적으로 유도한 세 가지의 두경부자세변화 (0$^{\circ}$, 30$^{\circ}$ 굴절, 45$^{\circ}$ 신전)에 따른 교합안정장치의 장착(1시 간) 전후 및 안정위와 근접촉위(초기치아접촉위)에서의 두경부 근육(측두근, 교근, 악이복근)의 근전도를 Bioelectric Microprocessor EM2ⓡ를 사용하여 측정한 후 통계학적으로 비교, 분석, 평가하여 다음과 같은 결과를 얻었다. 1. 교합안정장치 장착전 하악 안정위 및 근접촉위에서 두부의 30$^{\circ}$굴절은 악이복근의 근활성도를, 45$^{\circ}$신전은 교근 및 악이복근의 근활성도를 증가시켰다.(p<0.05) 2. 교합안정장치 장착후 하악 안정위에서 두부의 30$^{\circ}$굴절은 악이복근의 근활성도를, 45$^{\circ}$신전은 교근 및 악이복근의 근활성도를 증가시켰으며, 하악 근접촉위에서 두부의 45$^{\circ}$신전은 악이복근의 근활성도를 증가시켰다(p<0.05). 3. 교합안정장치 장착 전후 및 두부의 30$^{\circ}$굴절, 45$^{\circ}$신전에 따른 측두군 및 교근의 하악 근접촉위에서의 근활성도가 안정위에서의 근활성도에 비해 유의한 증가를 나타냈다(p<0.05).

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.6 no.1
• /
• pp.10-14
• /
• 2013

Pilomatricoma is a benign skin tumor that develops from hair matrix cells. It most commonly occurs in the head and neck, followed by the upper extremities. Accuracy of preoperative diagnosis was low in previous studies and excisional biopsy was even performed frequently without imaging studies. We report a case of pilomatricoma of the shoulder that was easily diagnosed by ultrasound including color Doppler, which is a more useful imaging modality than computed tomography or magnetic resonance imaging scans not only because of its cost effectiveness but also because of the precise information obtained from mass contents.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.31 no.1
• /
• pp.26-35
• /
• 2022

Patients who miss teeth partially or fully show many changes which make them lose function and esthetics.From the esthetic point of view, loosing teeth makes lower face unharmonized. There are various changes of lower and whole face according as how much change oral cavity is. Restoring the multiple teeth missing properly can make patient's face harmonized. Especially full mouth implant restorations can cause drastic occlusal change affecting masticatory muscles. Because all the muscles are connected closely, the masticatory muscles which is part of lower facial muscles can cause whole muscle change. In full mouth implant restoration case, I will show the whole face muscle change harmonized by meticulous occlusal treatment process. Full mouth restorations installed in right way show whole face muscle changes extending to head and neck muscles.

• Progress in Medical Physics
• /
• v.20 no.4
• /
• pp.244-252
• /
• 2009

The purpose of this study is to compensate for susceptibility and a ferromagnetic body artifact using CFA and TGV on MR Imaging. A total of 30 patients (15 men and 15 women, mean age: 45 years) were performed on head and neck diseases. MR Unit used a 1.5T superconducting magnet (GE medical system, High Density). This study have investigated by changing with CFA and TGV (70, 90, 110, 130, 150) searching for compensation values about susceptibility and a ferromagnetic body artifact in 60 kg standards of body weight (p<0.05). As a quality results, Image qualities were obtained at different score from CFA and TGV (70, 90, 110, 130, $150=3.23{\pm}0.35$, $4.31{\pm}0.02$ $4.23{\pm}0.21$, $5.12{\pm}0.25$, $7.13{\pm}0.72$, $8.31{\pm}0.01$, $5.21{\pm}0.15$, $6.14{\pm}0.08$, $5.23{\pm}0.72$, $5.91{\pm}0.06$, p<0.05). Absolute CNRs (TG, CNRpre, CNRpost) were acquired with (70:$-1.44{\pm}0.11$, $-2.7{\pm}0.04$, 90:$-2.18{\pm}0.42$, $-4.41{\pm}0.43$, 110:$-2.89{\pm}0.43$, $-5.23{\pm}0.02$, 130:$-2.34{\pm}0.05$, $-5.26{\pm}0.01$, 150: $-2.09{\pm}0.08$, $-3.87{\pm}0.12$, p<0.05). In conclusions, this study could be compensated for metal and flow artifacts surrounding the tissues having artifact by changing CFA and TGV.

• Radiation Oncology Journal
• /
• v.5 no.2
• /
• pp.97-104
• /
• 1987

From January 1970 through December 1984, 15 patients with sinonasal Non-Hodgkin's lymphoma combined to the head and neck were treated by external irradiation.13 patients were stage It and 2 were stage IIE by Ann Arbor Classification. However, when using TNM system, 7 were locally advanced T3, T4 lesions. All patients had follow up from 3.7 to 16 years with the median follow-up of 8.5 years. The overall actuarial 5-year survival rates were $25\%,\;28\%$ for IE and $0\%$ for IIE. Total tumor dose varied from 40 to 68 Gy. $100\%$ complete response with a total tumor dose of more than 55 Gy and $73\%$ complete response with less than 55Gy. When the disease was staged using the TNM (AJC) system, the five-year disease free survival for T1 and T2 patients was $50\%$ as compared with $14\%$ for T3 and T4. Failure rate by stage was $33\%(2/6)$ for T1 and T2, $86\%(6/7)$ for T3 and T4, and $100\%$(2/2) for IIE. The results suggest that 1. Higher CR could be obtained with a total tuner dose of more than 55 Gy. 2. Use of TNM staging system is as important as Ann arbor in management of sinonasal NHL. 3. The addition of combination chemotherapy should be considered for T3, T4 and IIE the sinonasal Non-Hodgkin's lymphoma although the disease is limited to head and neck.

• Korean Journal of Head & Neck Oncology
• /
• v.14 no.2
• /
• pp.182-190
• /
• 1998

Background: Most of the cancers of maxillary sinus are the squamous variety, but various histopathologic types of malignant tumor can occur in the maxillary sinus. These non-squamous cell tumors have quite different patterns of clinical behavior compared with squamous variety, such as invasive characters, route of metastasis, treatment modality, and so on. Objectives: The authors intend to establish the clinical characteristics and treatment modalities of non-squamous cell tumors of the maxillary sinus. Material and Methods: We experienced 16 cases of non-squamous cell tumors arisen from the maxillary sinus during the 10-year period from 1987 to 1996. We analyzed their clinical features, therapeutic modalities and results with review of literatures. Results: According to AJCC TNM system, 13 patients presented with $T_{1-2}$, 3 with $T_{3-}4$, Two patients were treated with surgery after radiotherapy, 3 patients with surgery after chemotherapy and radiotherapy, 4 patients with chemotherapy and radiotherpy, 5 patients with chemotherapy and radiotherapy after surgery. Conclusion: In cases of adenoid cystic carcinoma, adenocarcinoma and sarcoma, we believe that the best form of therapy is wide surgical excision. If there is microscopic evidence of disease at or close to the resection margin, postoperative radiation was used to achieve better local control. In cases of undifferentiated carcinoma, preoperative chemotherapy and radiation therapy showed improved outcomes.

• Korean Journal of Head & Neck Oncology
• /
• v.14 no.2
• /
• pp.244-252
• /
• 1998

The thyroid nodules are the most common endocrine disease requiring surgical management. We perfomed a clinical study of 298 cases with thyroid nodules, who were admitted to and operated at the Department of Surgery, College of Medicine, Gyeong sang National University from January 1987 to April 1997 and the results were summarized as follows: 1) Patients were composed of 214 cases(71.8%) of benign nodule and 84 cases(28.2%) of malignant nodule. Benign and malignant nodules were prevalent in fifth decade. 2) The sex distribution showed a preponderance of females with ratio of 5.88:1 in benign nodule and 11:1 in malignant nodule. 3) The nodules were located in the right lobe(134 cases, 44.9%), the left lobe(121 cases, 40.6%), both lobes(34 cases, 11.4%), and isthmus(8 cases, 2.7%). The possibility of malignancy was higher in the solid rather than cystic lesions. 4) Radioactive iodine scintiscans were perfomed in 273 cases and revealed cold nodules in 237 cases(86.8%), 58 of these cases(24.4%) were malignant. 5) According to the histopathologic classification, benign nodules included follicular adenomas 136 cases(63.5%), adenomatous goiters 67 cases(31.3%), Hurthle cell adenomas 4 cases(1.9%), cysts 3 cases(1.4%) and thyroiditis 4 cases(1.4%). In malignant nodules, papillary carcinomas 72 cases(85.7%), follicular carcinoma 8 cases(9.5%), undifferentiated carcinoma 2 cases(2.4%), medullary carcinoma 1 case(1.2%) and malignant lymphoma 1 case(1.2%). 6) The most commonly performed operative procedure was a lobectomy with isthmusectomy(85.5%) for bengn nodules and a total thyroidectomy(51.2%) for malignant nodules. 7) The rate of complications was higher in the cases with malignant nodules(20.2%) than in the benign cases(0.5%). The recurrence rate was 8.3%(7 cases).