Radiation Exposure of Surgical Team During Endourological Procedures: International Atomic Energy Agency-South-Eastern European Group for Urolithiasis Research Study

Introduction: Fluoroscopy-guided endourology procedures require proper radiation protection to minimize radiation risk. This multicenter study aimed at investigating radiation protection practice and related radiation exposure of operating team members. Materials and Methods: Six endourology centers from the South-Eastern European Group for Urolithiasis Research answered questionnaires and collected data of 315 procedures performed within a 3-months period, with simultaneous measurement of dose to staff and dose area product (DAP) to patient. A pair of calibrated personal dosimeters, one for body and one for eye-lens dose, was worn by all key staff members. Dosimeters were centrally calibrated, measured, and analyzed. Results: The annual workload ranged from 173 to 865 procedures per center. Practice of personal dose monitoring and use of radiation protection shielding was found to be inconsistent. Lead aprons and thyroid collars were used by all, whereas protective eyewear was used in only half of centers. Due to the regular use of protective aprons, the whole-body dose of all 44 monitored staff members was safely below the regulatory dose limits. Eye-lens dose of 17 (14 urologists and 3 assisting staff) was above the dosimeter detection level, and dose per procedure varied from <10 to 63 μSv. The highest annual eye-lens dose of 13.5 mSv was found for the surgeon in the busiest department by using an over-the-couch X-ray tube without a ceiling suspended screen. Working closer to patient body with no protection resulted in a six-time higher eye-lens dose per DAP for a surgeon compared with others in the same center. Lower eye-dose per procedure was associated with lower DAP to patient and with the use of an under-the-couch tube, lower fluoroscopy pulse rate, collimation, fluoroscopy time, and acquired images. Conclusions: The study results call for the need to establish standard protocols about use of fluoroscopy during endourology procedures and to increase radiation protection knowledge and awareness of surgical staff.

Evaluation of Methods of Displaying the Real-Time Scattered Radiation Distribution during Fluoroscopically-Guided Interventions for Staff Dose Reduction

2D and 3D scatter dose display options are evaluated for usefulness and ease of interpretation for real-time feedback to staff to facilitate changes in individual positioning for dose reduction purposes, as well as improving staff consciousness of radiation presence. Room-sized scatter dose 3D matrices are obtained utilizing Monte Carlo simulations in EGSnrc. These distributions are superimposed on either a ceiling-view 2D graphic of the patient and table for reference or a 3D augmented reality (AR) display featuring a real-time video feed of the interventional room. A slice of the scatter dose matrix, at a selectable distance above the floor, is color-coded and superimposed on the computer graphic or AR display. The 3D display obtains depth information from a ceiling mounted Microsoft Kinect camera, which is equipped with a 1080p visual camera, as well as an IR emitter/receiver to generate a depth map of the interventional suite and persons within it. The 3D depth information allows parts of objects above the 2D dose map to pass through the map without being colorized by it so the height perspective of the dose map can be maintained. The 2D and 3D displays incorporate network information from the imaging system to scale the scatter dose with exposure factors and adjust rotation of the distribution to match the gantry. Demonstration images were displayed to neurosurgery interventional staff and survey responses were collected. Results from the survey indicated that scatter distribution displays would be desirable and helpful in managing staff dose.