Estimating radiation doses to the skin from interventional radiology procedures for a patient population with cancer.

Purpose: To estimate the peak radiation skin doses for interventional radiology cases performed at a cancer center, identify procedure types likely to result in skin doses exceeding the American College of Radiology's 3 Gy follow-up level, and determine a kerma area product (P(KA)) for use in monitoring.

Materials And Methods: A single-center retrospective study was performed to estimate doses from consecutive procedures performed during 2006. Of 6,598 procedures, 3,925 (60%) had P(KA) recorded and were included. Forty-three procedure types are represented.

Results: The median estimated peak skin dose was 39 mGy (third quartile, 205 mGy). In 2.6% of the cases, the estimated skin dose exceeded 3 Gy. No procedures resulted in skin doses greater than 15 Gy, and 94% of the cases resulted in skin doses less than 1 Gy. Procedure types with instances of skin doses greater than 1 Gy included hepatic, portal, and other arterial embolizations; diagnostic arteriography; biliary drainages; stent placements and catheter exchanges; nephrostomy/nephroureterostomy; urinary catheter exchanges; inferior vena cava filters; foreign body retrieval; abscess drainage; catheter exchange; and fistulography. Hepatic embolizations, nonhepatic arterial embolizations, and biliary drain/stent procedures were most likely to result in skin doses greater than 1 Gy. Significant variations in skin dose were noted within the same procedure type. No patients were noted to have developed any sequelae from radiation.

Conclusions: It is unlikely that typical cases in an oncologic interventional radiology practice would exceed the Joint Commission's "reviewable sentinel event" skin dose level of 15 Gy. A P(KA) trigger of 300 Gy cm(2) could be used in the authors' clinic to identify follow-up requirements.