In recent years various international organisations including IAEA, ICRP, and EURATOM consider interventional radiology procedures to be special practice, involving high doses of radiation with considerable potential risk associated with these procedures. The objective of this study is to assess dose to patients undergoing interventional procedures in five diagnostic facilities, leading to the establishment and utilization of Diagnostic Reference Levels in interventional procedures in Ghana.

A sample of 748 procedures performed in five hospitals in Ghana were collected. Hospitals were asked to complete a questionnaire giving information on procedure, equipment, and protocol, experience of operator graded in number of procedures performed, and complexity level of each procedure. The procedures type included percutaneous nephrostomy, Intraforaminal infiltration, catheter embolization, percutaneous liver drainage, intracranial circulation, intraoperative angiography, biopsy, abdominal aorta endoprosthesis, splenic angiography, biliary stenting. For each procedure, fluoroscopy time, incident air-kerma at the Interventional Reference Point (IRP), number of images (frame), kerma-area product (KAP) Fluoro and Total kerma-area product, together with total irradiation time were collected. The upper quartile of the median distribution for number of images, fluoroscopy time, total KAP, and KAP Fluoro were used as measure of DRL.

The study results shows that the proposed DRL dose metric ranged from a minimum of 1.8 Gy.cm and 5.51 Gy.cm for Percutaneous Liver Drainage to a maximum of 86.98 and 118.80 for Abdominal Aorta Endoprosthesis in terms of KAP Fluoro and Total KAP respectively. The study also observed that the abdominal aorta endoprosthesis procedures took a longer time with significant number of images to performed relative to other cases. Time for abdominal aorta endoprosthesis procedure could be as much as three-fold comparable to the period needed for Intraforaminal infiltration, with more images acquired in the same procedures. The effect of this longer length of time and more image acquired resulted in higher patients’ radiation dose, in terms of KAP Fluoro and total KAP, as applied to abdominal aorta endoprosthesis than any other procedures. The DRLs were found to be strongly influenced by clinical circumstances like complexity of the procedure, the length of time, training and experience of the operator. Furthermore, it was also observed that, the quality of the images for each procedure had direct positive correlation with estimated patient dose values.

The preliminary results of this study propose local DRLs for the selected procedures, setting a good basis for establishment of a national DRL for interventional procedures in Ghana. The proposed DRL values are comparable to international published data from Spain, US and Switzerland.