PURPOSE: The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. MATERIALS AND METHODS: Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-S (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study. Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instruments, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. RESULTS: With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surface doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p< 0.01). CONCLUSION: The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer's machines.
Radiation Dosage ; Radiography ; Seoul

The aims of this study are (1) to determine the scattered radiation dose levels in routine fluoroscopy procedures and (2) to compare them with the equivalent chest x-rays and also (3) to monitor common techniques and radiation safety measures taken by the medical officers. The study covered a sample of 105 fluoroscopic procedures performed by 18 medical officers. Each officer wore a personal pocket dosimeter inside the lead gown during each procedure. A digital dosimeter was placed near the detector of the fluoroscopy unit while a survey meter was positioned at the control panel area to record the dose levels. There were 14 types of examination included in this study. The total number of images captured was found to be the highest in barium swallow examination with 115 images, almost five times higher compared to the common practices. The longest screening time was observed in barium enema examination which is 9.15 seconds. The median of the scattered dose level was the highest in barium meal examination (165.50 μSv) which is equivalent to 8.28 times of average dose impart by chest x-ray examinations. The number of images and the length of screening time depend on the competency levels of the medical officers. They capture as many images as possible to avoid missing any abnormalities, therefore it will always be better if the fluoroscopist is consulted during each case. They should also consistently practice essential protection by minimizing exposure time, maximizing distance from the source tube and utilizing the radiation shielding.
Fluoroscopy ; Radiation Dosage

PURPOSE: To investigate the presence of adaptive response by low dose radiation in murine tumors in relation to radiation induced apoptosis as well as related mechanism. MATERIALS AND METHODS: Syngeneic murine tumors, OCa-I and HCa-I, were given 0.05 Gy pretreatment followed by therapeutic dose of 25 Gy radiation. Induction of apoptosis was analyzed for each treatment group. Regulating molecules of apoptosis, p53, Bcl-2, Bax, Bcl-X, were also analyzed by Western blotting. RESULTS: In 0.05 Gy pretreatment group of OCa-I, 25 Gy-induced apoptosis per 1000 cells was 229, which was estimated at 30% lower level than the expected (p<0.05). In contrast, this reduction in radiation induced apoptosis was not seen in HCa-I. In the expression of apoptosis regulating molecules, p53 increased in both tumors in response to radiation. Bcl-2 and Bax did not show significant change in both tumors however, the expression of Bcl-2 surpassed that of Bax in 0.05 Gy pretreatment group of OCa-I. Bcl-X was not expressed in OCa-I. In HCa-I, Bcl-X showed increased expression even with 0.05 Gy. CONCLUSION: Adaptive response by low dose radiation is shown in one murine tumor, OCa-I, in relation to radiation induced apoptosis. Apoptosis regulating molecules including Bcl-2/Bax and Bcl-X, appear to related. This study shows an evidence that adaptive response is present, but not a generalized phenomenon in vivo.
Apoptosis* ; Blotting, Western ; Radiation Dosage

Performing external beam radiotherapy alone without chemotherapy or brachytherapy for locally advanced cervical cancer with multiple lymph node metastases is challenging. The purpose of this case report is to present the efficacy of high‑dose adaptive extended‑field intensity‑modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) in treating locally advanced cervical cancer with multiple lymph node metastases. A 67‑year‑old woman with locally advanced squamous cell carcinoma of the uterine cervix was treated by external beam radiotherapy alone due to the refusal of chemotherapy and intracavitary brachytherapy. In order to maximize the efficacy of treatment, extended‑field radiotherapy that includes the paraaortic lymph nodes as well as an adaptive IMRT‑SIB plan, was applied. The treatment was successful, resulting in complete tumor disappearance without severe adverse events. In conclusion, high‑dose adaptive IMRT‑SIB may be an alternative treatment option for locally advanced cervical cancer with multiple lymph node metastases.
Radiation Dosage ; Uterine Cervical Neoplasms

The standard of YY/T 0481-2004 Medical diagnostic X-ray equipment-Radiation conditions for use in the determination and characteristics has been revised and replaced in 2012. This paper first introduces the key technical problems to be solved in establishing standard radiation quality and radiation conditions by comparing the main changes of the two versions standards, including the expression of radiation quality and radiation conditions, the measurement of X-ray tube voltage, and the measuring of the practical peak voltage. Then it introduces a procedure for establishing standard radiation quality and radiation conditions.
Radiation Dosage ; Radiography ; Reference Standards

OBJECTIVES: This study was aimed to investigate the methods to reduce operator's radiation dose when taking intraoral radiographs with portable dental X-ray machines. MATERIALS AND METHODS: Two kinds of portable dental X-ray machines (DX3000, Dexcowin and Rextar, Posdion) were used. Operator's radiation dose was measured with an 1,800 cc ionization chamber (RadCal Corp.) at the hand level of X-ray tubehead and at the operator's chest and waist levels with and without the backscatter shield. The operator's radiation dose at the hand level was measured with and without lead gloves and with long and short cones. RESULTS: The backscatter shield reduced operator's radiation dose at the hand level of X-ray tubehead to 23 - 32%, the lead gloves to 26 - 31%, and long cone to 48 - 52%. And the backscatter shield reduced operator's radiation dose at the operator's chest and waist levels to 0.1 - 37%. CONCLUSIONS: When portable dental X-ray systems are used, it is recommended to select X-ray machine attached with a backscatter shield and a long cone and to wear the lead gloves.
Hand ; Radiation Dosage ; Radiation Protection ; Radiography, Dental, Digital ; Thorax

Objective To design a novel automatic dispensing and injecting system of positron radiopharmaceuticals,for precise dose dispensing,simplified operation,and reduction of occupational radiation exposure. Methods The automatic dispensing and injecting system was fabricated with tungsten alloy as the shielding material.The performance and radiation protection of the device were assessed. Results The total time of injection using the automatic dispensing and injecting system was about 60 s.The ratio of successful injection in stability test was 100%.The deviation of the dispensing dose with the system was ≤3%.With the tungsten alloy shield(40 mmPb of the cabinet,60 mmPb of the countertop,15 mmPb of the protective shield,and 50 mmPb of the inbuilt jar for radiopharmaceuticals),the average dose rate at 30 cm from the device was 1.44 μSv/h,and the radiation dose at the operator's extremity was reduced by 99%. Conclusions This automatic dispensing and injecting system of positron radiopharmaceuticals is easy to operate with precise dispensing dose.It is safe and meets the requirements of radiation protection.
Electrons ; Occupational Exposure/analysis* ; Radiation Dosage ; Radiation Protection ; Radiopharmaceuticals

No abstract available.
Humans ; Radiation Injuries/etiology ; Radiation, Ionizing ; Radiotherapy Dosage ; *Societies, Scientific

In order to compare the radiation immunity test level of ISO 14708 series standards and the domestic and international environmental radiation standards and then to ascertain whether the radiated immunity test level has reached the limit of the radiation strength in the relevant radiation environmental standards, this paper calculated the radiation field intensity and power density according to the radiated immunity test of ISO 14708 standards, and compared with the limit of ICNIRP 1998 and GB 8702-2014.
Electromagnetic Fields ; Electromagnetic Radiation ; Immunity ; Prostheses and Implants ; Radiation Dosage

In order to overcome the shortcomings of traditional X-ray inspection taking passive protection mode, this paper combines the automatic control technology, puts forward a kind of active protection X-ray equipment. The device of automatic detection of patients receiving X-ray irradiation part, intelligent adjustment in patients and shooting device between automatic tracking radiation protection device height. The device has the advantages of automatic adjustment, anti-radiation device, reduce the height of non-irradiated area X-ray radiation and improve the work efficiency. Testing by the professional organization, the device can decrease more than 90% of X-ray dose for patients with non-irradiated area.
Humans ; Radiation Dosage ; Radiation Protection ; instrumentation ; methods ; X-Rays