A systematic review of conversion factors between kerma-area product and effective/organ dose for cardiac interventional fluoroscopy procedures performed in adult and paediatric patients

Abstract

The aim of this systematic review is to undertake a critical appraisal of the evidence in the published literature concerning the conversion factors between kerma-area product (P_KA) and effective/organ dose (DC_{ED_PKA}, DC_{HT_PKA}) for cardiac interventional fluoroscopy procedures performed in adults and paediatric patients and to propose reference conversion factors to help standardize dose calculations. A search strategy utilizing MeSH headings in three databases identified 59 (adult) and 37 (paediatric) papers deemed eligible for the review. Exclusion criteria were adopted to select data only from publications which established DC_{ED_PKA}in patients using the ICRP 103 tissue weighting factors. A time restriction from January 2007 was introduced in the search to capture the evolving trends of utilization of fluoroscopy-guided intervention technologies only in recent years. The suggested DC_{ED_PKA}and DC_{HT_PKA}were synthesized by calculating the weighted averages of the values reported by the authors with weights corresponding to the study sample size. Eighteen studies for both adult (9) and paediatric (9) patients matching the search terms fulfilled the inclusion criteria. The suggested value for DC_{ED_PKA}in adult patients amounts to 0.24 mSv Gy^-1cm^-2. The suggested values for DC_{HT_PKA}ranged from a minimum of 0.15 mSv Gy^-1cm^-2for the female breast to a maximum of 0.97 mSv Gy^-1cm^-2for the lungs. The suggested values for DC_{ED_PKA}in paediatric patients ranged from 3.45 mSv Gy^-1cm^-2for the new-born to 0.49 mSv Gy^-1cm^-2in the 15 years age class. The suggested values for DC_{HT_PKA}ranged from a minimum of 0.33 mSv Gy^-1cm^-2for bone marrow in the 15 years age class to a maximum of 11.49 mSv Gy^-1cm^-2for the heart in the new-born. To conclude, values of DC_{ED_PKA}/DC_{HT_PKA}were provided for calculating effective/organ doses in cardiac interventional procedures. They can be useful for standardizing dose calculations, hence for comparison of the radiation detriment from different imaging procedures and in the framework of epidemiologic studies.

Keywords: conversion factors; effective dose; interventional cardiology; kerma-area product; organ dose.