Interventional radiology

Full text: Interventional radiology (IR) refers to a group of procedures that use fluoroscopy, computed tomography, ultrasound and MRI guidance to allow minimally invasive treatment. There has been a rapid increase in the use of IR over the last twenty years, due to the improvement on the materials necessary for the procedures, and to the availability of the modern diagnostic units. In addition, IR reduces the need for many traditional interventions, particularly surgery, therefore reducing the overall discomfort and risks for the patient compared to the traditional systems. Although the justification for most interventional radiology procedures is clear in terms of the stochastic risk to the patient, there are certain procedures, however, which are medically indicated but may involve a risk of radiation-induced injury of the patient. These injuries have occurred from the more complex procedures that involve long fluoroscopy times and high levels of absorbed dose to the skin, resulting in deterministic effects ranging from temporary epilation of the head, to more serious skin injuries sometimes requiring a graft. Over the last decade, the use of interventional radiology has seen skin doses as high as 1Gy up to 10Gy being reported. In fluoroscopic procedures, patient dose is affected by a large variety of factors including fluoroscopy time, number of images, field size, small focus-skin distances, projection angle, magnification, patient size and operator experience to name just a few. Protocols for patient dosimetry have generally recommended dose-area product (DAP) monitoring of procedures involving fluoroscopy, however more recently it has been recommended that methods should be developed for estimating skin dose. Typical dose values, problems associated with literature comparison and ways to ensure that IR procedures are performed optimally will be discussed. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine