PURPOSE: An investigation has been carried out on the factors which affect the response reading of thermoluminescent dosimeters (TLD-100) loaded with thin material in high energy photon. The aim of the study was to assess the energy response of TLD-100 to the therapeutic ranges of photon beam. MATERIALS AND METHODS: In this technique, TLD-100 (abbreviated as TLD) chips and three different thin material (Tin, Gold, and Tissue equivalent plastic plate) which mounted on the TLD chip were used in the clinical photon beam. The thickness of each metal plates was 0.1 mm and TE plastic plate was 1 mm thick. These compared with the photon energy dependence of the sensitivities of TLD (normal chip), TLD loaded with Tin or Gold plate, for the photon energy range 6 MV to 15 MV, which was of interest in radiotherapy. RESULTS: The enhancement of surface dose in the TLD with metal plate was clearly detected. The TLD chips with a Gold plate was found to larger response by a factor of 1.83 in 10 MV photon beam with respect to normal chip. The sensitivity of TLD loaded with Tin was less than that for normal TLD and TLD loaded with Gold. The relative sensitivity of TLD loaded with metal has little energy dependence. CONCLUSION: The good stability and linearity with respect to monitor units of TLD loaded with metal were demonstrated by relative measurements in high energy photon (6~15 MV) beams. The TLD laminated with metals embedded system in solid water phantom is a suitable detector for relative dose measurements in a small beam size and surface dose.
Metals ; Plastics ; Radiotherapy ; Tin ; Water

Adult ; Carcinoma, Renal Cell ; complications ; pathology ; Castleman Disease ; complications ; pathology ; Humans ; Kidney Neoplasms ; complications ; pathology ; Male ; Sentinel Lymph Node Biopsy

PURPOSE: LiF TLD has a problem to be used in vivo dosimetry because of the toxic property of LiF. The aim of this study is to develop new dosimeter with LiF TLD to be used in vivo dosimetry. MATERIALS AND METHODS: We designed and manufactured the teflon box(here after TLD holder) to put TLD in. The external size of TLD holder is 4x4x1 mm3. To estimate the effect of TLD holder on TLD response for radiation, the linearity of TLD response to nominal dose were measured for TLD in TLD holder. Measurement were performed in the 10 MV x-ray beam with LiF TLD using a solid water phantom at SSD of 100 cm. Percent Depth Dose (PDD) and Tissue-Maximum Ratio (TMR) with varying phantom thickness on TLD were measured to find the effect of TLD holder on the dose coefficient used for dose calculation in radiation therapy. RESULTS: The linearity of response of TLD in TLD holder to the nominal dose was improved than TLD only used as dosimeter. And in various measurement conditions, it makes a marginnal difference between TLD in TLD holder and TLD only in their responses. CONCLUSION: It was proven that the TLD in TLD holder as a new dosimetry could be used in vivo dosimetry.
Polytetrafluoroethylene ; Silver Sulfadiazine ; Water

Introduction: Metabolic syndrome is associated with low-grade, chronic inflammation. Our study aimed to evaluate the effects of tocotrienols supplementation on cytokines and lipid profile in adults with metabolic syndrome. Method: In a 16-week randomised, double-blind, placebo-controlled trial, 70 adults with metabolic syndrome aged 20-60 years were randomly assigned to a mixed tocotrienols group (n=35) that received 400mg/day of mixed tocotrienols or a placebo group (n=35) that received capsules containing soy bean oil. At baseline, week 8 and week 16, anthropometric, body composition and blood pressure measurements were conducted. At baseline and week 16 only, serum levels of total cholesterol (TC) and high density lipoprotein (HDL)-cholesterol, plasma levels of fasting plasma glucose (FPG), interleukin-6 (IL-6), tumouxr necrosis factor- a (TNF-a), leptin, adiponectin and high sensitivity C-reactive protein were also determined. Changes in dietary intake and physical activity level between baseline, week 8 and week 16 were also assessed. Results:In the tocotrienols group, significant reductions from baseline were found in diastolic blood pressure (p=0.001), TC (p=0.008), LDL-cholesterol (p=0.022), HDL-cholesterol (p<0.001), IL-6 (p=0.024) and TNF-a (p=0.013) at week sixteen. However, the changes in the tocotrienols group were not significantly different from those of the placebo group. Conclusion: The 16-week mixed tocotrienols supplementation exerted potential beneficial effects on cytokines and lipid profile in adults with metabolic syndrome. The results might have been confounded by the physiological effects produced by the soy bean oil in the placebo capsule.

A docking intraoperative electron beam applicator system, which is easily docking in the collimator for a linear accelerator after setting a sterilized transparent cone on the tumor bearing area in the operation room, has been designed to optimize dose distribution and to improve the efficiency of radiation treatment method with linear accelerator. This applicator system consisted of collimator holder with shielded metals and docking cone with transparent acrylic cylinder. A number of technical innovations have been used in the design of this system, this docking cone gives a improving latral dose coverage at therapeutic volume. The position of 90% isodose curve under surface of 8 cm diameter cone was extended 4~7 mm at 12 MeV electron and the isodose measurements beneath the cone wall showed hot spots as great as 106% for acrylic cone. The leakage radiation dose to tissues outside the cone wall was reduced as 3~5% of output dose. A comprehensive set of dosimetric characteristics of the intraoperative radiation therapy applicator system is presented.
Metals ; Particle Accelerators

Increasing frequency of skin cancer, mycosis fungoides, Kaposi's sarcoma etc, it need to treatment dose planning for total skin electron beam (TSEB) therapy. Appropriate treatment planning for TSEB therapy is needed to give homogeneous dose distribution throughout the entire skin surface. The energy of 6 MeV electron from the 18 MeV medical linear accelerator was adapted for superficial total skin electron beam therapy. The energy of the electron beam was reduced to 4.2 MeV by a 0.5cm x90cm x180cm acryl screen placed in a feet front of the patient. Six dual field beam was adapted for total skin irradiation to encompass the entire body surface from head to toe simultaneously. The patients were treated behind the acryl screen plate acted as a beam scatterer and contained a parallel-plate shallow ion chamber for dosimetry and beam monitoring. During treatment, the patient was placed in six different positions due to be homogeneous dose distribution for whole skin around the body. One treatment session delivered 400 cGy to the entire skin surface and patients were treated twice a week for eight consecutive weeks, which is equivalent to TDF value 57. Instrumentation and techniques developed in determining the depth dose, dose distribution and bremsstrahlung dose are discussed.
Foot ; Head ; Humans ; Mycosis Fungoides ; Particle Accelerators ; Sarcoma, Kaposi ; Skin Neoplasms* ; Skin* ; Toes

From May 1979 through December 1981 a total of 524 patients with carcinoma of the uterine cervix were treated by radiation therapy with curative intent. Among the 524 patients, 356 were treated with a high-dose-rate (HDR), remote-controlled, afterloading intracavitary irradiation (ICR) system using a cobalt source (Ralstron), and 168 patients received a low-dose-rate (LER) ICR using a radium source. External beam irradiation with a total dose of 40-50 gy to the whole pelvis followed by intracavitary irradiation with a total dose or 30-39 gy in 10-13 fractions to point A was the treatment protocol ICR was given three times a week with a dose of 3 gy per fraction. Five-year actuarial survival rates in the HER-ICR group were 77.6% in stage IB (N=20), 68.2% in stage II (N=182), and 50.9% in stage III (N=148). In LDR-ICR group, 5-year survival rates were 87.5% in stage IB (N=22), 66.3% in stage II (N=91), and 55.4% in stage III (N-52). Survival rates showed a statistically significant difference by stage, but there was no significant difference between the two ICR groups. Late bowel complications after radiotherapy were noted in 3.7% of the HDR-ICR group and 8.4% of the LDR-ICR group. There was no severe complication requiring surgical management. The incidence of bladder complications was 1.4% in the HDR-ICR group and 2.4% in the LDR-ICR group. The application of HDR-ICR was technically simple and easily performed on an outpatient basis without anesthesia, and the patients tolerated it very well. Radiation exposure to personnel was virtually nil in contrast to that of LDR-ICR. Within a given period of time, more patients can be treated with HDR-ICR because of the short treatment time. Therefore, the HDR-ICR system is highly recommended for a cancer center, particularly one with a large number of patients to be treated. In order to tachieve an improved outcome, however, the optimum dose-fractionation schedule of HDR-ICRand optimum combination of intracavitary irradiation with external beam irradiation should be determined through an extensive protocol study with different treatment regimens.
Anesthesia ; Appointments and Schedules ; Cervix Uteri* ; Clinical Protocols ; Cobalt ; Female ; Humans ; Incidence ; Outpatients ; Pelvis ; Radiotherapy ; Radium ; Survival Rate ; Urinary Bladder

A noncontact, noninvasive, electrical permittivity imaging technique is proposed for monitoring loosening of osseointegrated prostheses and bone fracture. The proposed method utilizes electrical capacitance tomography (ECT), which employs a set of noncontact electrodes, arranged in a circular fashion around the imaging area, for electrical excitations and measurements. An inverse reconstruction algorithm was developed and implemented to reconstruct the electrical permittivity distribution of the interrogated region from boundary capacitance measurements. In this study, osseointegrated prosthesis phantoms were prepared using plastic rods and Sawbone femur specimens, which were subjected to prosthesis loosening and fracture monitoring tests. The results demonstrated that the spatial location and extent of prosthesis loosening and bone fracture could be estimated from the ECT reconstructed permittivity maps. The resolution of the reconstructed images was further enhanced by a limited region tomography algorithm, and its accuracy in terms of identifying the severity, location, and shape of bone fracture was also investigated and compared with conventional full region tomography.
Electric Capacitance* ; Electrodes ; Femur ; Fractures, Bone ; Methods ; Plastics ; Prostheses and Implants* ; Prosthesis Failure*

INTRODUCTIONNorovirus gastrointestinal disease (GID) outbreaks occur frequently in closed settings, with high attack rates. On October 16, 2008, a norovirus GID outbreak occurred at a Singapore military camp. This study describes the epidemiological investigations conducted to determine the cause of outbreak and the efficacy of the public health measures implemented.

METHODSEpidemiologic investigations included a case-control study of exposure to different food items and an environmental exposure survey. Stool samplings of patients and food handlers for common pathogens, and microbiologic testing of food and water samples were performed. Inspection of dining facilities and health screening of all food-handlers were also conducted.

RESULTSA total of 156 GID cases were reported on October 15-31, 2008. 24 (15.4%) personnel were positive for norovirus. The predominant symptoms were diarrhoea (76.3%) and abdominal pain (69.2%). There was no clinical correlation between any food item and the affected personnel. Testing of food and water samples, dining facility inspections and health screening of food handlers showed satisfactory results. The environmental exposure survey indicated possible transmission due to environmental contamination by vomitus in common areas. Comprehensive environmental decontamination was performed with hypochlorite solution, and personal hygiene measures were enforced. The outbreak lasted 17 days, with a decline in cases post intervention.

CONCLUSIONTimely notification and prompt response can curtail disease transmission. Swift implementation of public health measures, such as emphasis on personal hygiene, isolation of affected cases and comprehensive disinfection of the environment, effectively stopped norovirus transmission and may be adapted for future GID outbreaks.

Acute Disease ; Adolescent ; Caliciviridae Infections ; diagnosis ; epidemiology ; Case-Control Studies ; Communicable Disease Control ; methods ; Diarrhea ; virology ; Disease Outbreaks ; statistics & numerical data ; Feces ; virology ; Food Handling ; Gastroenteritis ; epidemiology ; virology ; Humans ; Male ; Military Facilities ; Norovirus ; isolation & purification ; Singapore ; epidemiology ; Water Microbiology ; Young Adult

From March 1970 to December 1984, 21 patients treated initially with curative surgery for adenocarcinoma of the colon, referred to the Department of Radiation Oncology, College of Medicine, Yonsei University, were analyzed retrospectively. Thirteen of 21 patients who were considered to be ah high risk group (i.e, mainly stage B2 or above), received adjuvant postoperative radiation therapy. However, 2 of 13 patients did not complete their courses of radiotherapy as planned because of poor tolerance to radiotherapy or patient's refusal and were excluded from this study. Remaining 8 of 21 patients who did not received postoperative radiotherapy, presented with recurrence at the time of referral and treated with palliative radiotherapy. In 11 patients with postoperative radiotherapy, overall local failure rate was 9% (1/11) and the 5 year acturial survival rate was 55%. Local failure rates by stage were 0(0/4), 14%(1/7) for stage B2+B3, C1+C2+C3 respectively and 0(0/2), 17%(1/6), 0(0/3) for stage C1, B2+C2, B3+C3 respectively.
Adenocarcinoma* ; Colon* ; Disulfiram ; Humans ; Radiation Oncology ; Radiotherapy ; Recurrence ; Referral and Consultation ; Retrospective Studies ; Survival Rate