Effect of correction methods of radiochromic EBT2 films on the accuracy of IMRT QA.

Radiochromic films are dosimeters with more favorable characteristics than other two-dimensional (2D) radiation detectors. Transmission film scanners using a linear charge-coupled device (CCD) array have a drawback of variation in response along the detector array, which may result in a nonuniform transmission of signal over the scanned image. This study uses 2D gamma index analysis to compare two methods for correcting the nonuniform response of EBT2: the first method was based on the new red:blue method proposed by the manufacturer (to compensate for small nonuniformities in the film coating) and the second method, proposed by Menegotti et al. (2008), was based on dose-dependent matrix correction factors. The gamma index analysis shows that both the methods are comparably accurate for all the criteria values used for evaluation (1 mm/1%, 2 mm/2%, 3 mm/3%). Centers around the world use both the methods to correct EBT2 local heterogeneities, but it is important to note that the former method has several advantages such as less time consumption and easy implementation.

How are we protecting ourselves from radiation exposure? A nationwide survey.

PURPOSE: We performed a nationwide survey of Brazilian urologists to study behaviors toward radiation exposure and the use of protective and monitoring equipment. METHODS: A 13-question e-mail questionnaire was sent to 4,526 Brazilian urologists; the questions addressed demographic characteristics, radiation exposure, and the utilization of shielding devices and dosimeters. The reasons why these devices were not used were also investigated. RESULTS: A total of 332 completed questionnaires were analyzed (7.3 %); the median age of the respondents was 43.3 ± 10.8 years. Lead aprons and thyroid protection are utilized in every procedure by 84.4 and 53.89 % of respondents, respectively. Protective eyeglasses are never used by 72.12 % of the respondents. Older urologists were more likely not to use adequate protection. Of the urologists who responded, 76.42 % never use dosimeters. CONCLUSION: This study shows an unsatisfactory utilization of radiation-shielding devices and dosimeters, revealing a low compliance to the as low as reasonably achievable principle among Brazilian urologists.

Methodology for characterizing seeds under development for brachytherapy by means of radiochromic and photographic films.

The development of new medical devices possess a number of challenges, including designing, constructing, and assaying prototypes. In the case of new brachytherapy seeds, this is also true. In this paper, a methodology for rapid dosimetric characterization of (125)I brachytherapy seeds during the early stages of their development is introduced. The characterization methodology is based on the joint use of radiochromic and personal monitoring photographic films in order to determine the planar anisotropy due to the radiation field produced by the seed under development, by means of isodose curves. To evaluate and validate the process, isodose curves were obtained with both types of films after irradiation with a commercial (125)I brachytherapy seed.

Cardiac catheterization laboratory survey: 1990. Society for Cardiac Angiography and Interventions, Laboratory Performance Standards Committee.

A survey of 117 member cardiac catheterization laboratories was undertaken by the Society for Cardiac Angiography and Interventions. The survey included numbers and types of procedures, both diagnostic and interventional, in adult as well as pediatric age groups. Radiation safety, various laboratory policies, frequency of short stay, and outpatient procedures were tabulated. Report generation, training programs, administrative organization, and laboratory equipment were all included. The results were compared with a 1978 survey. Areas of concern in terms of safety of the patient and possible underutilization of laboratories were identified.