Dose levels in medical staff at hemodynamics services in Minas Gerais State, Brazil - preliminary results

Abstract

Medical staff during interventional radiology could be exposed to radiation conditions that may cause very high dose levels depending on the X-ray machine operational conditions. The dose levels received by medical staff during interventional radiology are very high depending on the operational conditions and the patient trunk thickness. Dose levels could reach a factor of 30 for fluoroscopy or cine modes. The ALARA principle, which emphasizes the adoption of techniques and procedures to keep dose levels as low as reasonably achievable, should be followed to minimize the risk of radiation exposure to medical professionals. Dose reduction could be achieved by persuading the medical staff to wear protection devices (lead apron, thyroid protector, eyeglasses and gloves). Additionally, medical staff should also be persuaded that they should not be submitted to very high doses, above the acceptable limits for occupational workers. Dose levels at hemodynamics services in Minas Gerais State, Brazil, were analyzed. Due to the equipment characteristics or the exam type and conditions X-ray machines were used with 70-120 kV, 2.5-699mA and 80-2880 s. Annual individual doses were estimated based on measured doses during a specific exam taking into account the workload. Maximum doses varied from 0.05 to 0.70 mSv per exam. The results projected for one work-year period show that all annual individual doses would be higher than the annual dose limit of 20 mSv/y with only a few values lower than 50 mSv/y. Dose levels measured at medical staff positions during hemodynamic exams showed that if the protective devices are not used professionals could be exposed to dose values higher than annual dose limits.