• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.85-93
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• 2012

Purpose: It is essential to minimize the respiratory-induced motion of involved organs in the Tomotherapy for tumor located in the chest and abdominal region. However, the application of breathing control system to Tomotherapy is limited. This study was aimed to investigate the possible application of the ABCHES system and its efficacy as a means of breathing control in the tomotherapy treatment. Materials and Methods: Five subjects who were treated with a Hi-Art Tomotherapy system for lung, liver, gallbladder and pancreatic tumors. All patients undertook trained on two breathing methodes using an ABCHES, free breathing methode and shallow breathing methode. When the patients could carry out the breathing control, 4D-CT scan was a total of 10 4D tomographic images were acquired. A radiologist resident manually drew the tumor region, including surrounding nomal organs, on each of CT images at the inhalation phase, the exhalation phase and the 40% phase (mid-inhalation) and average CT image. Those CT images were then exported to the Tomotherapy planning station. Data exported from the Tomotherapy planning station was analyzed to quantify characteristics of dose-volume histograms and motion of tumors. Organ motions under free breathing and shallow breathing were examined six directions, respectively. Radiation exposure to the surrounding organs were also measured and compared. Results: Organ motion is in the six directions with more than a 5 mm displacement. A total of 12 Organ motions occurred during free breathing while organ motions decreased to 2 times during shallow breathing under the use of Abches. Based on the quantitative analysis of the dose-volume histograms shallow breathing showed lower resulting values, compared to free breathing, in every measure. That is, treatment volume, the dose of radiation to the tumor and two surrounding normal organs (mean doses), the volume of healthy tissue exposed to radiation were lower at the shallow breathing state. Conclusion: This study proposes that the use of ABCHES is effective for the Tomotherapy treatment as it makes shortness of breathing easy for patients. Respiratory-induced tumor motion is minimized, and radiation exposure to surrounding normal tissues is also reduced as a result.

• The Journal of Korean Society for Radiation Therapy
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• v.20 no.1
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• pp.37-43
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• 2008

Purpose: To evaluate dosimetry results of three different techniques for whole breast irradiation after conservative surgery of large pendulous breast patient. Materials and Methods: Planning computed tomography (CT) scans for three techniques were performed on a GE Hi-speed advantage CT scanner in the supine (SP), supine with breast supporting Device (SD) and prone position on a custom prone mattress (PP). Computed tomography images were acquired at 5 mm thickness. The clinical target volumes (CTV), ipsilateral lung and heart were delineated to evaluate the dose statistic, and all techniques were planned with the tangential photon beams (Pinnacle$^3$, Philips Medical System, USA). The prescribed dose was 50 Gy delivered in 25 fractions. To evaluate the dose coverage for CTV, we analysed percent volume of CTV receiving minimum of 95%, 100%, 105%, and 110% of prescription dose ($V_{95}$, $V_{100}$, $V_{105}$, and $V_{110}$) and minimal dose covering 95% ($D_{95}$) of CTV. The dosimetric comparison for heart and ipsilateral lung was analysed using the minimal dose covering 5% of each organs ($D_5$) and the volume that received >18 Gy for the heart and >20 Gy for the ipsilateral lung. Results: Target volume coverage ($V_{95}$ and $V_{100}$) was not significantly different for all technique. The V105 was lower for PP (1.2% vs. 4.4% for SP, 11.1% for SD). Minimal dose covering 95% ($D_{95}$) of target was 47.5 Gy, 47.7 Gy and 48 Gy for SP, SD and PP. The volume of ipsilateral lung received >20 Gy was 21.7%, 11.6% and 4.9% for SP, SD and PP. The volume of heart received >18 Gy was 17.0%, 16.1% and 9.8% for SP, SD and PP. Conclusion: Prone positioning of patient for large pendulous breast irradiation enables improving dose uniformity with minimal heart and lung doses.

• Journal of radiological science and technology
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• v.34 no.1
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• pp.51-58
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• 2011

The aim of the study is to analyze the dose delivery error depending on the depth variation according to target positions and arc trajectories by comparing the simulated treatment planning with the actual dose delivery in conformal arc therapy. We simulated the conformal arc treatment planning with the three target positions (center, 2.5 cm, and 5 cm in the phantom). For the experiments, IMRT body phantom (I’mRT Phantom, Wellhofer Dosimetry, Germany) was used for treatment planning with CT (Computed Tomography, Light speed 16, GE, USA). The simulated treatment plans were established by three different target positions using treatment planning system (Eclipse, ver. 6.5, VMS, Palo Alto, USA). The radiochromic film (Gafchromic EBT2, ISP, Wayne, USA) and dose analysis software (OmniPro-IMRT, ver. 1.4, Wellhofer Dosimetry, Germany) were used for the measurement of the planned arc delivery using 6 MV photon beam from linear accelerator (CL21EX, VMS, Palo Alto, USA). Gamma index (DD: 3%, DTA: 2 mm) histogram and dose profile were evaluated for a quantitative analysis. The dose distributions surrounded by targets were also compared with each plans and measurements by conformity index (CI), and homogeneity index (HI). The area covered by 100% isodose line was compared to the whole target area. The results for the 5 cm-shifted target plan show that 23.8%, 35.6%, and 37% for multiple conformal arc therapy (MCAT), single conformal arc therapy (SCAT), and multiple static beam therapy, respectively. In the 2.5 cm-shifted target plan, it was shown that 61%, 21.5%, and 14.2%, while in case of center-located target, 70.5%, 14.1%, and 36.3% for MCAT, SCAT, and multiple static beam therapy, respectively. The values were resulted by most superior in the MCAT, except the case of the 5 cm-shifted target. In the analysis of gamma index histogram, it was resulted of 37.1, 27.3, 29.2 in the SCAT, while 9.2, 8.4, 10.3 in the MCAT, for the target positions of center, shifted 2.5 cm and 5 cm, respectively. The fail proportions of the SCAT were 2.8 to 4 times as compared to those of the MCAT. In conclusion, dose delivery error could be occurred depending on the target positions and arc trajectories. Hence, if the target were located in the biased position, the accurate dose delivery could be performed through the optimization of depth according to arc trajectory.

• Radiation Oncology Journal
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• v.26 no.2
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• pp.83-90
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• 2008

Purpose: For the first time, a nationwide survey of the Patterns of Care Study(PCS) for the various radiotherapy treatments of esophageal cancer was carried out in South Korea. In order to observe the different parameters, as well as offer a solid cooperative system, we compared the Korean results with those observed in the United States(US) and Japan. Materials and Methods: Two hundreds forty-six esophageal cancer patients from 21 institutions were enrolled in the South Korean study. The patients received radiation theraphy(RT) from 1998 to 1999. In order to compare these results with those from the United States, a published study by Suntharalingam, which included 414 patients[treated by Radiotherapy(RT)] from 59 institutions between 1996 and 1999 was chosen. In order to compare the South Korean with the Japanese data, we choose two different studies. The results published by Gomi were selected as the surgery group, in which 220 esophageal cancer patients were analyzed from 76 facilities. The patients underwent surgery and received RT with or without chemotherapy between 1998 and 2001. The non-surgery group originated from a study by Murakami, in which 385 patients were treated either by RT alone or RT with chemotherapy, but no surgery, between 1999 and 2001. Results: The median age of enrolled patients was highest in the Japanese non-surgery group(71 years old). The gender ratio was approximately 9:1(male:female) in both the Korean and Japanese studies, whereas females made up 23.1% of the study population in the US study. Adenocarcinoma outnumbered squamous cell carcinoma in the US study, whereas squamous cell carcinoma was more prevalent both the Korean and Japanese studies(Korea 96.3%, Japan 98%). An esophagogram, endoscopy, and chest CT scan were the main modalities of diagnostic evaluation used in all three countries. The US and Japan used the abdominal CT scan more frequently than the abdominal ultrasonography. Radiotherapy alone treatment was most rarely used in the US study(9.5%), compared to the Korean(23.2%) and Japanese(39%) studies. The combination of the three modalities(Surgery+RT+Chemotherapy) was performed least often in Korea(11.8%) compared to the Japanese(49.5%) and US(32.8%) studies. Chemotherapy(89%) and chemotherapy with concurrent chemoradiotherapy(97%) was most frequently used in the US study. Fluorouracil(5-FU) and Cisplatin were the most preferred drug treatments used in all three countries. The median radiation dose was 50.4 Gy in the US study, as compared to 55.8 Gy in the Korean study regardless of whether an operation was performed. However, in Japan, different median doses were delivered for the surgery(48 Gy) and non-surgery groups(60 Gy). Conclusion: Although some aspects of the evaluation of esophageal cancer and its various treatment modalities were heterogeneous among the three countries surveyed, we found no remarkable differences in the RT dose or technique, which includes the number of portals and energy beams.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.763-773
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• 1996

Background : Behçet's syndrome is a chronic multisystemic disease affecting many organs such as skin, mucosa, eye, joint, central nervous system and blood vessels. Lung involvement occurs in 5% of Behçet's syndrome and is thought to be due to the pulmonary vasculitis leading to thromboembolism, aneurysm and arteriobronchial fistula. Pulmonary vasculitis in Behçet's syndrome is a unique clinical feature, differing from other vasculitis affecting the lung and is one of the major causes of death. Therefore, we examined the incidence, the clinical features, the radioloic findings and the clinical courses of the lung involvement in Behçet's syndrome. Methods: We retrospectively reviewed the medical records and radiologic studies of 10 cases of the lung involvement in Behçet's syndrome diagnosed at Yongdong Severance Hospital and Severance Hospital from 1986 to 1995. We analysed the clinical features, the radiological findings, the treatment modalities and the clinical courses. Results: 1) The incidence of the lung involvement in Behçet's syndrome was 2%(10/487). The male to female ratio was 8 : 2 and the mean age was 34 years. The presenting symptom was hemoptysis in 5 of 10 cases, and massive hemoptysis was noted in 2 cases. Other pulmonary symptoms were cough(6/10), dyspnea(4/10), and chest pain(2/10). Other manifestations were oral ulcers(10/10), genital ulcers(9/10), skin lesions(7/10), and eye lesions(6/10). 2) The laboratory findings were nonspecific. The posteroanterior views of chest radiographies showed multiple infiltrates(6/10), nodular or mass-like opacities(4/10), or normal findings(2/10). The chest CT scans showed multifocal consolidations(6/8), and aneurysms of the pulmonary aneries(4/8). The pulmonary angiographies were performed in 3 cases, and showed pulmonary artery aneurysms in 2 cases. The ventilation-perfusion scans in 2 cases of normal chest x-ray showed multiple mismatched findings. 3) The patients were treated with combination therapy consisting of corticosteroids, cyclophosphamide, and colchicine or anticoagulant agents. Surgical resection was performed in one case with a huge aneurysm. 4) We have followed up nine of ten cases. Three cases are well-being with medical therapy, two cases are severely disabled now and four cases died due to massive hemoptysis, massive pulmonary embolism, or sepsis. Conclusion : Pulmonary vasculitis is a main feature of the lung involvement of Behçet's syndrome, causing hemorrhage, aneurysmal formation, and/or thromboemboism. The lung involvement of Behçet's syndrome is uncommon but is one of the most serious prognostic factors of the disease. Therefore, an aggressive diagnostic work-up for early detection and proper treatment are recommended to improve the clinical course and the survival.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.231-237
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• 2010

Purpose: We investigated the effect of location changes in the inferior border of the belly board (BB) aperture by adding a bladder compression device (BCD). Materials and Methods: We respectively reviewed data from 10 rectal cancer patients with a median age 64 years (range, 45~75) and who underwent computed tomography (CT) simulation with the use of BB to receive pelvic radiotherapy between May and September 2010. A CT simulation was again performed with the addition of BCD since small bowel (SB) within the irradiated volume limited boost irradiation of 5.4 Gy using the cone down technique after 45 Gy. The addition of BCD made the inferior border of BB move from symphysis pubis to the lumbosacral junction (LSJ). Results: Following the addition of BCD, the irradiated volumes of SB and the abdominopelvic cavity (APC) significantly decreased ($174.3{\pm}89.5mL$ vs. $373.3{\pm}145.0mL$, p=0.001, $1282.6{\pm}218.7mL$ vs. $1,571.9{\pm}158mL$, p<0.001, respectively). Bladder volume within the treated volume increased with BCD ($222.9{\pm}117.9mL$ vs. $153.7{\pm}95.5mL$, p<0.001). The ratio of irradiated bladder volume to APC volume with BCD ($33.5{\pm}14.7%$) increased considerably compared to patients without a BCD ($27.5{\pm}13.1%$) (p<0.001), and the ratio of irradiated SB to APC volume decreased significantly with BCD ($13.9{\pm}7.6%$ vs. $24.2{\pm}10.2%$, p<0.001). The ratios of the irradiated SB volume and irradiated bladder volume to APC volume negatively correlated (p=0.001). Conclusion: This study demonstrated that the addition of BCD, which made the inferior border of BB move up to the LSJ, increased the ratio of the bladder to APC volume and as a result, decreased the irradiated volume of SB.

• Progress in Medical Physics
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• v.25 no.3
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• pp.176-184
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• 2014

In this study, we compared dose distributions from simultaneously integrated boost (SIB) method versus the RTOG 0631 protocol for spine radiosurgery. Spine radiosurgery plans were performed in five patients with localized spinal metastases from hepatocellular carcinoma. The computed tomography (CT) and T1- and T2-weighted magnetic resonance imaging (MRI) were fused for delineating of GTV and spinal cord. In SIB plan, the clinical target volume (CTV1) was included the whole compartments of the involved spine, while RTOG 0631 protocol defines the CTV2 as the involved vertebral body and both left and right pedicles. The CTV2 includes transverse process and posterior element according to the extent of GTV. The doses were prescribed 18 Gy to GTV and 10 Gy to CTV1 in SIB plan, while the prescription of RTOG 0631 protocol was applied 18 Gy to CTV2. The results of dose-volume histogram (DVH) showed that there were competitive in target coverage, while the doses of spinal cord and other normal organs were lower in SIB method than in RTOG 0631 protocol. The 85% irradiated volume of VB in RTOG 0631 protocol was similar to that in the SIB plan. However, the dose to normal organs in RTOG 0631 had a tendency to higher than that in SIB plan. The SIB plan might be an alternative method in case of predictive serious complications of surrounded normal organs. In conclusion, although both approaches of SIB or RTOG 0631 showed competitive planning results, tumor control probability (TCP) and normal tissue complication probability (NTCP) through diverse clinical researches should be analyzed in the future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.4
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• pp.204-212
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• 2005

Recognition has emerged that nutrient inputs from the submarine discharge of fresh, brackish, and marine groundwaters into the coastal ocean are comparable to the inputs via river discharge. The coastal areas of the Korea peninsula and adjacent seas exhibit particular importance in the role of submarine groundwater discharge (SGD), in terms of the magnitude of SGD and associated continental material fluxes. For example, in the southern sea of Korea, SGD transports excess nutrients into the coastal regions and thus appears to influence ecosystem changes such as the outbreak of red tides. Around volcanic island, Jeju, which is composed of high permeability rocks, the amount of SGD is higher by orders of magnitude relative to the eastern coast of North America where extensive SGD studies have been conducted. In particular, nutrient discharge through SGD exerts a significant control on coastal ecosystem changes and results in benthic eutrophication in semi-enclosed Bang-du bay, Jeju. In the entire area of the Yellow Sea, tile submarine discharge of brackish groundwater and associated nutrients are found to rival the river discharges into the Yellow Sea, including those through Yangtze River, Han River, etc. In the eastern coast of the Korea peninsula, SGD is significantly higher during summer than winter due to high hydraulic gradients and due to wide distribution of high permeability sandy zones, faults, and fractures. On the other hand, in the estuarine water, downstream construction of the dam in the Nakdong River, SGD was highest when the river discharge was lowest (but water level of the dam was highest). This suggests that even though there is no visible freshwater discharge into this estuary, the discharge of chemical species is significant through SGD. On the basis of the results obtained from the coastal areas of the Korea peninsula, SGD is considered to be an important pathway of continental contaminants influencing tidal-flat ecosystems, red tides, and coral ecology. Thus, future costal management should pay great attention to the impact of SGD on coastal pollution and eutrophication.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.63-75
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• 2012

This paper gives some basic requirements and preferences of various geological environmental conditions for the final deep geological repository of spent nuclear fuel (SNF). This study also indicates how the requirements and preferences are to be considered prior to the selection of sites for a site investigation as well as the final disposal in Korea. The results of the study are based on the knowledge and experience from the IAEA and NEA/OECD as well as the advanced countries in SNF disposal project. This study discusses and suggests preliminary guideline of the disposal requirements including geological, mechanical, thermal, hydrogeological, chemical and transport properties of host rock with long term geological stabilities which influence the functions of a multi-barrier disposal system. To apply and determine whether requirements and preferences for a given parameter are satisfied at different stages during a site selection and suitability assessment of a final disposal site, the quantitative criteria in each area should be formulated with credibility through relevant research and development efforts for the deep geological environment during the site screening and selection processes as well as specific studies such as productions of safety cases and validation studies using a generic underground research laboratory (URL) in Korea.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.1
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• pp.31-37
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• 2012

Purpose: This study evaluated the usefulness of Helmet bolus device using Bolx-II, paraffin wax, solid thermoplastic material in total scalp irradiation. Materials and Methods: Using Rando phantom, we applied Bolx-II (Action Products, USA), paraffin wax (Densply, USA), solid thermoplastic material (Med-Tec, USA) on the whole scalp to make helmet bolus device. Computed tomography (GE, Ultra Light Speed16) images were acquired at 5 mm thickness. Then, we set up the optimum treatment plan and analyzed the variation in density of each bolus (Philips, Pinnacle). To evaluate the dose distribution, Dose-homogeneity index (DHI, $D_{90}/D_{10}$) and Conformity index (CI, $V_{95}/TV$) of Clinical Target Volume (CTV) using Dose-Volume Histogram (DVH) and $V_{20}$, $V_{30}$ of normal brain tissues. we assessed the efficiency of production process by measuring total time taken to produce. Thermoluminescent dosimeters (TLD) were used to verify the accuracy. Results: Density variation value of Bolx-II, paraffin wax, solid thermoplastic material turned out to be $0.952{\pm}0.13g/cm^3$, $0.842{\pm}0.17g/cm^3$, $0.908{\pm}0.24g/cm^3$, respectively. The DHI and CI of each helmet bolus device which used Bolx-II, paraffin wax, solid thermoplastic material were 0.89, 0.85, 0.77 and 0.86, 0.78, 0.74, respectively. The result of Bolx-II was the best. $V_{20}$ and $V_{30}$ of brain tissues were 11.50%, 10.80%, 10.07% and 7.62%, 7.40%, 7.31%, respectively. It took 30, 120, 90 minutes to produce. The measured TLD results were within ${\pm}7%$ of the planned values. Conclusion: The application of helmet bolus which used Bolx-II during total scalp irradiation not only improves homogeneity and conformity of Clinical Target Volume but also takes short time and the production method is simple. Thus, the helmet bolus which used Bolx-II is considered to be useful for the clinical trials.