• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.69-76
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• 2014

Purpose : To evaluate the changes of the motion of abdominal cavity between interfraction and intrafraction by using abdominal compression for reducing abdominal motion. Materials and Methods : 60 MVCT images were obtained before and after tomotherapy from 10 prostate cancer patients over the whole radiotherapy period. Shift values ( X -lateral Y -longitudinal Z -vertical and Roll ) were measured and from it, the correlation of between interfraction set up change and intrafraction target motion was analyzed when applying abdominal compression. Results : The motion changes of interfraction were X-average $0.65{\pm}2.32mm$, Y-average $1.41{\pm}4.83mm$, Z-average $0.73{\pm}0.52mm$ and Roll-average $0.96{\pm}0.21mm$. The motion changes of intrafraction were X-average $0.15{\pm}0.44mm$, Y-average $0.13{\pm}0.44mm$, Z-average $0.24{\pm}0.64mm$ and Roll-average $0.1{\pm}0.9mm$. The average PTV maximum dose difference was minimum for 10% phase and maximum for 70% phase. The average Spain cord maximum dose difference was minimum for 0% phase and maximum for 50% phase. The average difference of $V_{20}$, $V_{10}$, $V_5$ of Lung show bo certain trend. Conclusion : Abdominal compression can minimize the motion of internal organs and patients. So it is considered to be able to get more ideal dose volume without damage of normal structures from generating margin in small in producing PTV.

• Journal of the Korean Magnetics Society
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• v.26 no.3
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• pp.99-104
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• 2016

For patients receiving chemotherapy and radiation therapy treatment progresses as vomiting, nausea, weight of the patient because of a loss of appetite it is reduced. The patient's weight and the distance from the skin and the treatment site is expected to be closer, thereby reducing the change in the skin because of this dose. This study tests using a loose see the difference between the volume change appears as the weight of the patient using the same phantom and the phantom body of the patient. To using the same as the position EBT film is attached to the skin of the treatment site and was adjusted to the thickness of the Bolus. And using a computerized treatment planning only tomotherapy equipment was passed under the conditions according to the thickness of the radiation dose. To baseline for accurate reproduction position using the MVCT was applied to treated with verification. By passing a total of three dose reduced the error, it was a measure of the film by using a dedicated scanner, EBT VIDAR scanner. Got an increase in the skin dose is displayed each time the thickness of the bolus reduced, in a bolus was completely removed with the highest value. If the changes appeared dose was greater weight loss patients to chemotherapy and therefore bolus thickness variation considering the weight loss of the patient when applying the tomotherapy of nasopharynx cancer was found that the increase in skin dose be increased. This large patient before treatment due to weight loss over the image verification is considered to be established should consider how to re-create your mask and treatment plan for fixing it.

• Progress in Medical Physics
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• v.27 no.4
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• pp.250-257
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• 2016

The purpose of this study was to compare the patient setup errors of two different immobilization devices (Feet Fix: FF and Leg Fix: LF) for pelvic region radiotherapy in Tomotherapy. Thirty six-patients previously treated with IMRT technique were selected, and divided into two groups based on applied immobilization devices (FF versus LF). We performed a retrospective clinical analysis including the mean, systematic, random variation, 3D-error, and calculated the planning target volume (PTV) margin. In addition, a rotational error (angles, $^{\circ}$) for each patient was analyzed using the automatic image registration. The 3D-errors for the FF and the LF groups were 3.70 mm and 4.26 mm, respectively; the LF group value was 15.1% higher than in the FF group. The treatment margin in the ML, SI, and AP directions were 5.23 mm (6.08 mm), 4.64 mm (6.29 mm), 5.83 mm (8.69 mm) in the FF group (and the LF group), respectively, that the FF group was lower than in the LF group. The percentage in treatment fractions for the FF group (ant the LF group) in greater than 5 mm at ML, SI, and AP direction was 1.7% (3.6%), 3.3% (10.7%), and 5.0% (16.1%), respectively. Two different immobilization devices were affected the patient setup errors due to different fixed location in low extremity. The radiotherapy for the pelvic region by Tomotherapy should be considering variation for the rotational angles including Yaw and Pitch direction that incorrect setup error during the treatment. In addition the choice of an appropriate immobilization device is important because an unalterable rotation angle affects the setup error.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.1
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• pp.11-18
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• 2010

Purpose: In every time radiation therapy set up errors occur because internal anatomical organs move due to breathing and change of patient's position. These errors may affect the change of dose distribution between target area and normal structure. This study investigates the usefulness of body-fix in clinical treatment. Materials and Methods: Among 55~60 aged male patients who has hepatocellular carcinoma in area of liver's couinaud classification, we chose 10 patients and divided two groups by using body-fix or not. When applying body-fix, we maintained a vacuum of 80 mbar pressure by using vacuum pump (Medical intelligence, Germany). Patients had free breathing with supine position. After working to fuse and consist MV-CT (megavoltage computed tomography) with KV-CT (kilovoltage computed tomography) obtained by 5 times treatments, we compared and analyzed set up errors occurred to (Right to Left, RL) of X axis, (Anterioposterio, AP) of Z axis, (Cranicoudal, CC) of Y axis. Results: Average Set up errors through image fusion showed that group A moved $0.3{\pm}1.1\;mm$ (Cranicoudal, CC), $-1.1{\pm}0.7\;mm$ (Right to Left, RL), $-0.2{\pm}0.7\;mm$ (Anterioposterio, AP) and group B moved $0.62{\pm}1.94\;mm$ (Cranicoudal, CC), $-3.62{\pm}1.5\;mm$ (Right to Left, RL), $-0.22{\pm}1.2\;mm$ (Anterioposterio, AP). Deviations of X, Y and Z axis directions by applying body-fix indicated that maximum X axis was 5.5 mm, Y axis was 19.8 mm and Z axis was 3.2 mm. In relation to analysis of error directions, consistency doesn't exist for every patient but by using body-fix showed that the result of stable aspect in spite of changes of everyday's patient position and breathing. Conclusion: Using body-fix for liver cancer patient is considered effectively for tomotherapy. Because deviations between group A and B exist but they were stable and regular.

• Journal of the Korean Society of Radiology
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• v.6 no.5
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• pp.365-371
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• 2012

The radiation therapy treatment technique is developed from 3D-CRT, IMRT to Tomotherapy. and these three technique was most widely using methods. We find out a comparison normal tissue doses and tumor dose of 3D-CRT, IMRT(Linac Based), and Tomotherapy on Head and Neck Cancer. We achieved radiological image used the Human model phantom (Anthropomorphic Phantom) and it was taken CT simulation (Slice Thickness : 3mm) and GTV was nasopharngeal region and PTV(including set-up margin) was GTV plus 2mm area. and transfer those images to the radiation planning system (3D-CRT - ADAC-Pinnacle3, Tomotherapy - Tomotherapy Hi-Art System). The prescription dose was 7020 cGy and measuring PTV's dose and nomal tissue (parotid gland, oral cavity, spinal cord). The PTV's doses was Tomotherapy, Linac Based - IMRT, 3D-CRT was 6923 cGy, 6901 cGy and 6718 cGy its dose value was meet TCP because its value was up to the 95% based on 7020 cGy, Nomal tissue (parotid gland, oral cavity, spinal cord) was 1966 cGy(Tomotherapy), 2405 cGy(IMRT), 2468 cGy(3D-CRT)[parotid gland], 2991 cGy(Tomotherapy), 3062 cGy(IMRT), 3684 cGy (3D-CRT)[oral cavity], 1768 cGy(Tomotherapy), 2151 cGy(IMRT), 4031 cGy(3D-CRT)[spinal cord] its value did not exceeded NTCP. All the treatment techniques are equated with tumor and nomal tissue doses. The 3D-CRT was worse than other techniques on dose distribution, but it is reasonable in terms of TCP and NTCP baseline Tomotherapy, IMRT -dose distribution was relatively superior- was hard to therapy to claustrophobic patients and patients with respiratory failure. Particularly, in case on Tomotherapy, it take MVCT before treatment so dose measurement will be unnecessary radiation exposure to patients. Conclusion, Tomotherapy was the best treatment technique and 2nd was IMRT, and 3rd 3D-CRT. But applicable differently depending on the the patient's condition even though dose not matter.

• The Journal of Korean Society for Radiation Therapy
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• v.20 no.2
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• pp.83-89
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• 2008

Purpose: The checking method of target and normal structure are used by MVCBCT, KVCBCT, CT On-rail System, Ultrasound in H&N cancer patient. In case of MVCT, the utilization of bone structure is valuable to check around tissue. But the utilization of soft tissue is not enough. The point of this paper is dose variation in movable parotid and changeable volume of H&N cancer patient of CT On-rail System. Materials and Methods: The object of H&N cancer patient is 5 in this hospital. The selected patient are scanned ARTISTE CT Vision (CT On-ral System) a triweekly. After CT scanning, tranfered coordinates are obtained by movable of parotid gland comparison with planning image. Checking for the changeable volume of parotid gland. A Obtained CT image are tranfered to the RTP System. So dose variation are checked by following changed volume. Results: The changes of target coordinate by the parotid gland movement are X: -0.4~0.4 cm, Y: -0.4~0.3 cm, Z: -0.3~0.3 cm. the volume of GTV is decreased to about 7.11%/week and then both parotid gland volume are shrinked about 4.81%/week (Lt), 2.91%/week (Rt). At the same time, each parotid gland are diminished in radiation dose as 3.66%/week (Lt), 2.01%/week. Conclusion: Images from CT on the rail System which are able to aquire the better quality images of soft tissue in Target area than MVCBCT. After replanning and dose redistribution by required images, It could gain not only the correction of the patient set-tup errors but exact dose distribution. Accordingly, the delivery of compensated dose, It makes that we could do Adaptive Targeting Radiotherapy and need Real Time Adaptive Targeting Radiotherapy by reduce beam delivary time.