• Journal of the Korean Physical Society
• /
• v.73 no.10
• /
• pp.1577-1583
• /
• 2018

Tumor-treating fields therapy involves placing pads onto the patient's skin to create a low- intensity (1 - 3 V/cm), intermediate frequency (100 - 300 kHz), alternating electric field to treat cancerous tumors. This new treatment modality has been approved by the Food and Drug Administration in the USA to treat patients with both newly diagnosed and recurrent glioblastoma. To deliver the prescribed electric field intensity to the tumor while minimizing exposure of organs at risk, we developed an optimization method for the electric field distribution in the body and compared the electric field distribution in the body before and after application of this optimization algorithm. To determine the electric field distribution in the body before optimization, we applied the same electric potential to all pairs of electric pads located on opposite sides of models. We subsequently adjusted the intensity of the electric field to each pair of pads to optimize the electric field distribution in the body, resulting in the prescribed electric field intensity to the tumor while minimizing electric fields at organs at risk. A comparison of the electric field distribution within the body before and after optimization showed that application of the optimization algorithm delivered a therapeutically effective electric field to the tumor while minimizing the average and the maximum field strength applied to organs at risk. Use of this optimization algorithm when planning tumor-treating fields therapy should maintain or increase the intensity of the electric field applied to the tumor while minimizing the intensity of the electric field applied to organs at risk. This would enhance the effectiveness of tumor-treating fields therapy while reducing dangerous side effects.

• Journal of radiological science and technology
• /
• v.30 no.4
• /
• pp.435-442
• /
• 2007

The number of thyroid diseases treated with radioiodine(I-131) is increasing steadily. The sharp increase in patients who require high dose radioiodine therapy greatly increased the need for new therapy rooms. Accordingly, interest in radiation exposure is rising as well, and is a major psychological stress factor for the patient and those who come in close contact with the patient. This study aimed to minimize the radiation exposure on discharge. Based on various previous reports, the decision for discharge should be individualized depending on many factors related to the patient's living or working environment. Educating patients repeatedly on the importance of sufficient oral hydration, while the adequate amount was relative to the patient's individual condition, greatly lowered the detected radiation measurement within the same admission period. In some cases, the period of admission could be abbreviated.

• Journal of the Korean Society of Radiology
• /
• v.16 no.4
• /
• pp.471-476
• /
• 2022

The purpose of this study was to study the probability of cancer occurrence due to photoneutron dose exposure of the colon and thyroid gland, which are normal organs, in 3D CRT, IMRT 5 portals, and IMRT 9 portals, which are radiotherapy methods for prostate cancer. The total prescribed dose for prostate cancer was 6600 cGy, 220 cGy per dose, and 30 divided irradiations were applied for the total number of times. After setting up the Rando phantom on the treatment table (couch) of the medical linear accelerator used in the experiment, an optically stimulated luminescence albedo neutron dosimeter was placed on the corresponding area of the large intestine and thyroid gland of the phantom for measurement. During 3D CRT of prostate cancer, the probability of secondary cancer due to photoneutron dose to the colon and thyroid gland, which are normal organs, was 1.8 per 10,000 people. And IMRT 5 portals were 8.7 per 10,000 people, which was about 5 times larger than 3D CRT. IMRT 9 portals derived the result that there is a probability that 1.2 people per 1,000 people will develop cancer. Based on this study, the risk of secondary radiation exposure due to the dose of photoneutrons generated during radiation therapy is studied, and it is thought that it will be used as useful data for radiation protection in relation to the stochastic effect of radiation in the future.

• Proceedings of the KACD Conference
• /
• 2002.11a
• /
• pp.720-720
• /
• 2002

A number of investigations have shown that the presence of bacteria is prerequisite for developing pulpal and/or periradicular pathosis. Depending on the stage of pulpal pathosis, various species of bacteria can be cultured from infected root canals. Kakehashi et al. showed that exposure of pulpal tissue in germ-free rats was characterized by minimal inflammation and dentinal bridging while exposure of pulpal tissue in conventional rats with normal oral flora was characterized by pulpal necrosis, chronic inflammation, and periapical lesions. Currently used methods of cleaning and shaping, especially rotary instrumentation techniques, produce a smear layer that covers root canal walls and the openings to the dentinal tubules. The smear layer contains inorganic and organic substances that include fragments of odontoblastic processes, microorganisms, their by products and necrotic materials. Because of its potential contamination and adverse effect on the outcome of root canal therapy, it seems reasonable to suggest removal of the smear layer for disinfection of the entire root canal system. Presence of this smear layer prevents penetration of intracanal medications into the irregularities of the root canal system and the dentinal tubules and also prevents complete adaptation of obturation materials to the prepared root canal surfaces. Removal of the smear layer by an intracanal irrigant and placement of an antibacterial agent in direct contact with the content of dentinal tubules should allow disinfection of this complex system and better outcome for the root canal therapy. A new solution, which was a mixture of a tetracycline, an acid, and a detergent(MTAD), was developed in the Department of Endodontics, Dental School. Lorna Linda University, USA. It has been demonstrated that MTAD was an effective solution for the removal of the smear layer and does not significantly change the structure of the dentinal tubules when used as a final irrigant in conjunction with 1 % NaOCl as a root canal irrigant. Studies are in progress to compare the anti- microbial properties of this newly developed solution with those of sodium hypochlorite and EDTA that are currently used to irrigate the root canals and remove the smear layer from the surfaces of instrumented root canals.canals.

• Journal of Radiation Protection and Research
• /
• v.6 no.1
• /
• pp.34-40
• /
• 1981

The logical development of an optimum structural shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV. are presented. We obtained following results by comparison in between the precalculating values and actual survey after complete installation of radiogenerating units. 1. The calculating formula for the protective barrier written in NCRP report #34(1970) was the most ideal and economic calculating methods for the construction of barrier and to determine thickness for the meeting requirements of the number of patients of 80-100 in daily treatment. 2. The precalculating values of protective barrier are 5 times more protective than that of actual measurement. It is depending on radiation workload and utilization the datas most sequrely. 3. The dose rate during exposure are 2-10 mR/hr at out of the door and the controll room. 4. The foul smelling and ozone gas production from long exposure of cancer patients cannot be eliminated when the room is ill ventilated.

• Journal of Ginseng Research
• /
• v.34 no.2
• /
• pp.132-137
• /
• 2010

Lead (Pb) is a metal that is generally considered to be toxic to the cardiovascular system. Pb-exposed animals display the evidence of increased oxidative stress and hypertension. The current study was designed to examine whether Korean red ginseng (KRG) has protective effects against Pb-induced hypertension and oxidative stress in Pb-exposed rats. Male Sprague-Dawley rats were randomly assigned to Pb exposure or control groups. KRG was administered in drinking water at a concentration of 100 mg/kg/day; the control group received plain drinking water. Animals in the Pb-exposed groups were provided with drinking water containing 100 ppm Pb acetate for 12 weeks. Blood pressure, plasma glutathione, blood Pb concentration, and hematologic data, such as red blood cell quantity, were determined. Pb poisoning was assessed by measuring the blood Pb concentration. Pb exposure (100 ppm) for 12 weeks resulted in a marked rise in systolic blood pressure and blood Pb concentration, as well as a significant reduction in plasma glutathione levels and red blood cell quantity. Other measurements, such as heart rate, body weight, and white blood cell quantity, were unchanged. Treatment with KRG significantly lowered blood pressure, raised plasma glutathione and increased red blood cell numbers in Pb-exposed animals; it also had no effect on heart rate, body weight, or white blood cell quantity. However, the elevated blood Pb concentration was not reduced by treatment with KRG (100 mg/kg). Taken together, these data indicate that treatment with KRG in Pb-exposed animals can reduce oxidative stress and lower blood pressure, suggesting that KRG might be protective against Pb-exposed hypertension and oxidative stress.

• 한국HCI학회:학술대회논문집
• /
• 2006.02b
• /
• pp.639-645
• /
• 2006

During abstinence from alcohol, craving is elicited by the cues and contexts previously associated with alcohol, and contributes to relapse. To prevent the craving and relapse experienced by alcoholics, cue-exposure therapy (CET) has been used to extinguish the association between alcohol and alcohol-related cues and contexts. This study applied CET, using a virtual reality (VR) system, to eight members of an Alcoholics Anonymous group, in eight sessions. Cues and contexts most likely to elicit an urge to drink were selected through a preliminary survey in order to compose VR-CET scenarios: a glass, bottle, food, and a bar were judged to be the most tempting for people in alcohol dependence and abstinence. By these cues and contexts, a Japanese style pub and a western bar were composed. Each session was administered for 30 minutes by a psychiatrist and included an introduction, immersion, VR navigation, interviews about feelings, and self-report questionnaires about cravings. The eight sessions consisted of initial and closing sessions, and six cue- and context-focused sessions. As a result, a reduction in cue-elicited craving after VR-CET was reported. A mean score of 15.75 (SD = 10.91) on the Alcohol Urge Questionnaire in the first session decreased to 11.57 (SD = 6.88) in the final session.

• Archives of Plastic Surgery
• /
• v.41 no.5
• /
• pp.571-575
• /
• 2014

Background Disulfiram implantation is a widely used treatment alternative for alcohol abuse, yet reports on the surgical aspect of disulfiram implantation with respect to patient and drug-related treatment efficacy and wound complications are very limited. We present our clinical experiences with disulfiram implantation and discuss the surgical outcomes obtained with different anatomical planes for implantation. Methods Medical records of all patients referred to our clinic from the psychiatry department between 2007 and 2013 for disulfiram implantation were retrospectively analyzed. Implantation was carried out using 10 sterile Disulfiram tablets (WZF Polfa S.A.), each tablet containing 100 mg of disulfiram. The procedure was carried out by implanting the tablets randomly in either a subcutaneous or an intramuscular plane. The location and the plane of implantation and the complications were recorded for each patient and compared to determine the differences in the outcomes. Results A total of 32 implantation procedures were evaluated for this study. Twenty-five implants were placed in the intramuscular plane (78.2%), while seven implants were placed subcutaneously (21.8%). Exposure was encountered in three of the seven subcutaneous implants (42.9%), while no exposure was seen with the intramuscular implants. Incomplete absorption of the tablets was encountered in one patient with a previous subcutaneous implant who presented 1 year later for re-implantation as part of the continuation of therapy. Conclusions To overcome the issue of treatment continuation in the case of disulfiram therapy, which may be ceased due to frequently encountered wound complications, we believe that implantation in the subscapular intramuscular plane allows both uneventful healing and an out-of-reach implant location.

• Archives of Plastic Surgery
• /
• v.38 no.4
• /
• pp.508-511
• /
• 2011

Purpose: Blue toe syndrome consists of blue or purplish toes in the absence of a history of obvious trauma, serious cold exposure, or disorders producing generalized cyanosis. It is a life-threatening and still underrecognized disease. It can be commonly occurred by vascular surgery, invasive cutaneous procedures or anticoagulant therapy. Our case is presented of blue toe syndrome related to atheromatous embolization that was presumably triggered by angio CT. Methods: A 69-year-old man presented with the suddenly developed pain, cyanosis and livedo reticularis of the toes in right foot. Dorsalis pedis pulses were palpable. He had been performed a diagnostic angio CT 1 month earlier. Angio CT revealed diffuse aortic atheromatous plaque in lower abdominal aorta and both common iliac artery. One month after angio CT, he visited our clinic. There was no visible distal first dorsal metatarsal artery and digital artery of right first toe in lower extremity arteriography. A diagnosis was established of blue toe syndrome. Because his symptom was aggravated, we performed the exploration of the right foot. After exposure of first dorsal metatarsal artery, microsurgical atheroembolectomy was done. Results: There were no postoperative complications. After three months the patient had no clinically demonstrable problems. Conclusion: Patient with blue toe syndrome is at high risk of limb loss and mortality despite treatment. Blue toe syndrome produces painful, cyanosed toes with preserved pedal pulses. It needs to be aware of blue toe syndrome. Careful history should reveal the diagnosis. Treatment is controversial, however, most believe that anticoagulation therapy should be avoided.

• Journal of Radiation Protection and Research
• /
• v.45 no.4
• /
• pp.171-177
• /
• 2020

Background: This study aims to determine the effective atomic number (Zeff) from dual-energy image sets obtained using a conventional computed tomography (CT) simulator. The estimated Zeff can be used for deriving the stopping power and material decomposition of CT images, thereby improving dose calculations in radiation therapy. Materials and Methods: An electron-density phantom was scanned using Philips Brilliance CT Big Bore at 80 and 140 kVp. The estimated Zeff values were compared with those obtained using the calibration phantom by applying the Rutherford, Schneider, and Joshi methods. The fitting parameters were optimized using the nonlinear least squares regression algorithm. The fitting curve and mass attenuation data were obtained from the National Institute of Standards and Technology. The fitting parameters obtained from stopping power and material decomposition of CT images, were validated by estimating the residual errors between the reference and calculated Zeff values. Next, the calculation accuracy of Zeff was evaluated by comparing the calculated values with the reference Zeff values of insert plugs. The exposure levels of patients under additional CT scanning at 80, 120, and 140 kVp were evaluated by measuring the weighted CT dose index (CTDIw). Results and Discussion: The residual errors of the fitting parameters were lower than 2%. The best and worst Zeff values were obtained using the Schneider and Joshi methods, respectively. The maximum differences between the reference and calculated values were 11.3% (for lung during inhalation), 4.7% (for adipose tissue), and 9.8% (for lung during inhalation) when applying the Rutherford, Schneider, and Joshi methods, respectively. Under dual-energy scanning (80 and 140 kVp), the patient exposure level was approximately twice that in general single-energy scanning (120 kVp). Conclusion: Zeff was calculated from two image sets scanned by conventional single-energy CT simulator. The results obtained using three different methods were compared. The Zeff calculation based on single-energy exhibited appropriate feasibility.