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 Gycm² could be used in the authors' clinic to identify follow-up requirements.

Abbreviations: ACR, American College of Radiology, FDA, Food and Drug Administration, P_KA, kerma area product, PSD, peak skin dose