CONTEMPORARY RADIATION DOSES IN INTERVENTIONAL CARDIOLOGY: A NATIONWIDE STUDY OF PATIENT SKIN DOSES IN FINLAND

Establishment of institutional diagnostic reference level for coronary angiography procedures in Sri Lanka

Amongst many interventional procedures performed in a cardiac catheterisation laboratory, the coronary angiography (CAG) is the most frequently performed cardiac interventional procedure. A diagnostic reference level (DRL) is an effective tool to optimise the radiation exposure to patients and staff whilst maintaining the adequate diagnostic image quality. The aim of the study was to establish institutional DRLs for the CAG procedures performed at a selected private hospital in Colombo, Sri Lanka. A total of 325 CAG procedures were selected for this study from two C-arm machines. The institutional DRLs of cumulative dose length product (DAP) and fluoroscopic time for the CAG procedure were calculated. The established institutional DRL for accumulated DAP and fluoroscopic time are 10 610 mGycm2 and 2.31 min, respectively. As this study conducted at only one institute we recommend to develop national DRLs for mostly performing interventional procedures in Sri Lanka by considering all influencing factors to optimise the patient dose.

Validation of the MC-GPU Monte Carlo code against the PENELOPE/penEasy code system and benchmarking against experimental conditions for typical radiation qualities and setups in interventional radiology and cardiology

INTRODUCTION

Interventional procedures are associated with potentially high radiation doses to the skin. The 2013/59/EURATOM Directive establishes that the equipment used for interventional radiology must have a device or a feature informing the practitioner of relevant parameters for assessing patient dose at the end of the procedure. Monte Carlo codes of radiation transport are considered to be one of the most reliable tools available to assess doses. However, they are usually too time consuming for use in clinical practice. This work presents the validation of the fast Monte Carlo code MC-GPU for application in interventional radiology.

METHODOLOGIES

MC-GPU calculations were compared against the well-validated Monte Carlo simulation code PENELOPE/penEasy by simulating the organ dose distribution in a voxelized anthropomorphic phantom. In a second phase, the code was compared against thermoluminescent measurements performed on slab phantoms, both in a calibration laboratory and at a hospital.

RESULTS

The results obtained from the two simulation codes show very good agreement, differences in the output were within 1%, whereas the calculation time on the MC-GPU was 2500 times shorter. Comparison with measurements is of the order of 10%, within the associated uncertainty.

CONCLUSIONS

It has been verified that MC-GPU provides good estimates of the dose when compared to PENELOPE program. It is also shown that it presents very good performance when assessing organ doses in very short times, less than one minute, in real clinical set-ups. Future steps would be to simulate complex procedures with several projections.