Program Information

Scattered Radiation Dose-Rate Distribution Around An Interventional C-Arm Fluoroscope and Variation with Exposure Parameters

C Guo

C Guo*, Z Xiong , S Vijayan , S Rudin , D Bednarek , University at Buffalo, Buffalo, NY

Presentations

SU-E-702-3 (Sunday, July 30, 2017) 1:00 PM - 1:55 PM Room: 702

Purpose: The purpose of this work is to investigate a method to track dose-rate to staff locations in an interventional procedure room by evaluating the variation with the exposure parameters of the scattered radiation dose-rate distribution around a C-Arm fluoroscopic system.

Methods: EGSnrc Monte Carlo (MC) software was used to model the x-ray beam of a Toshiba Infinix fluoroscopy machine and to generate the 3D scattered radiation distribution from a patient phantom. For this study, a 32 cm PMMA body phantom was modeled and each MC simulation used 2 x 109 photons. A library of 3D distributions of dose rate is being developed and we are investigating how the distributions vary with parameters such as the field size and shape, kVp, beam filter, C-arm angulation, and patient size and shape.

Results: The results show that the room scattering distribution changes with collimator settings at distances less than 2 meters, but the distribution shape remains essentially constant at larger distances when scaled. With the same collimator setting, the variation of distribution with kVp is mainly dependent on primary beam intensity changes. The scatter intensity changes proportionally with factors such as pulse rate, mA and pulse width but maintains the same shape of isodose lines.

Conclusion: The intensity and distribution of scattered radiation can vary considerably with changes in exposure parameters. Knowing the scatter distribution and how it changes can provide guidance to staff on where to stand in the room and how to reduce their exposure during fluoroscopically-guided procedures.

Funding Support, Disclosures, and Conflict of Interest: This research was supported in part by NIH Grant R01EB002873 and Toshiba Medical Systems Corp.


Contact Email: