Development of a look-up table of Dose Conversion Coefficient for Interventional Radiology and Cardiology

SCK•CEN Mentor

Lombardo Pasquale, plombard@sckcen.be, +32 (0)14 33 28 54

Expert group

Research in Dosimetric Applications

SCK•CEN Co-mentor

Abdelrahman Mahmoud , mabdelra@sckcen.be , +32 (0)14 33 27 53

Introduction

Interventional radiologists receive the highest doses among the medical staff. In the future, it is foreseen that these will further increase because of the increasing number of clinical tasks and procedures performed through interventional radiology [1]. In routing monitoring, the doses to the whole body are measured using a single physical dosimeter place on the chest of the doctor. However, with a single measurement the doses received by other body parts cannot be estimated, despite the fact that the tissues such as the hand skin, the eye lens and the even the brain are often exposed to the highest doses. Ideally, in order to monitor the doses to all these body parts, several dosimeters should be worn. However, wearing multiple dosemeters and especially finger dosemeters can be very unpractical for the doctor, and it could hinder the surgery. Furthermore, the sensitivity of the dosemeters is very dependent on the angular and energy distribution of the radiation field, which negatively affects the accuracy of the dose estimation.

On the other hand, thanks to the evolution of hardware and software, computational methods can be used to answer for resolving these limitations of dosimetry. With this project, we want to provide more accurate dose estimation by using a purely computational approach based on computer vision and Monte Carlo simulations.

Objective

The aim of this project is to create a look-up table of conversion coefficients for complex irradiation directions. The conversion coefficients will be used to develop a dosimetric system for replacing dosemeters with a purely computational methodology. This system requires proper dose conversion factors, flexible computational phantoms representing the workers anatomy and spatial radiation field, including energy and angular distribution to be available. The spatial radiation field are obtained from the information on the tube angulation, operator position and beam collimation as well as area monitors in the surroundings. The real movement of the operators are monitored in real‑time using motion tracking cameras based on the Time-of-Flight (TOF) principle, and flexible computational phantoms representing the workers anatomy. The phantom will be positioned using the tracking information from the TOF camera. Finally, all this input data should be converted to Monte-Carlo input by means of an in-house conversion program, allowing to calculate the doses to the staff.

The proposed internship is dealing with the part of calculating the proper dose conversion factors. ICRP dose conversion factors reports cover simple exposure situations and approximations are often used for complex exposure situations like in the interventional radiology in which the radiation beam is not a mono-energetic parallel and the geometry is not the idealized standard exposure geometries beam of ionizing radiation and . By avoiding using approximations and using particular dose conversion factors for each complex exposure situation will result in a more accurate estimation of the workers’ dose [3].

[1] International Commission on Radiological Protection. Avoidance of radiation injuries from medical interventional procedures. ICRP Publication 85. Annals of the ICRP 30(2) 2000

[2] Donadille L, Carinou E, Ginjaume M, Jankowski J, Rimpler A, Sans Merce M, et al. An overview of the use of extremity dosemeters in some European countries for medical applications. Rad Prot Dosim 2008;131:62–6

[3] International Commission on Radiological Protection, ICRP Publication 119 , Compendium of Dose Coefficients based on ICRP Publication 60, Ann. ICRP 41(Suppl.), 2012.

The minimum diploma level of the candidate needs to be

Academic bachelor

The candidate needs to have a background in

Mathematics , Informatics , Physics