WASHINGTON, D.C.—Use of a pelvic lead shield draped on a patient and a nonlead cap worn by an operator during coronary angiography reduced physician radiation exposure by more than 75 percent in a study presented Sept. 14 at the Transcatheter Cardiovascular Therapeutics scientific session.
Reports of head and neck tumors occurring in interventional cardiologists prompted researchers at McMaster University in Hamilton, Ontario, to design and conduct the RADIATION PROTECT study, Ashraf Alazzoni, MD, explained. Of particular concern for operators was the disproportional incidence of brain tumors on the left side, which is exposed to radiation during interventions,
“There is still uncertainty if the radiation dose we receive as operators causes tumors but we agree we should all work at minimizing radiation exposure as much as possible,” Alazzoni said.
The McMaster team took a two-pronged approach to attempt to lower operator dose. First, they customized a commercially available lead drape to be placed over a patient with access at the pelvic area for femoral or radial procedures. The drape, in theory, would protect the operator from scattering. Second, they added a lightweight, nonlead surgical cap to protect the head.
The prospective trial randomized 113 patients undergoing coronary angiographies to receive the lead drape and 115 patients to serve as controls to assess the efficacy of the approach. The outcomes were operator dose, measured by a dosimeter worn on the operators left chest, and the difference between the cap’s measured external and internal dose during procedures.
They found that the mean operator dose was 6.39 mSv/Gy in the drape group vs. 23.6 mSv/Gy in the control group, for a reduction of 75 percent. With cap, the mean dose was 2.99 mSv/Gy inside vs. 10.75 mSv/Gy, for a reduction of 80 percent.
One patient said the drape was uncomfortable, Alazzoni said, and that patient was small. One a scale of 1 to 10, with 10 being most comfortable, operators gave the cap a score of 9.
Panelists pointed out that the drape may increase radiation dose in patients, especially during lengthy cases. Alazzoni acknowledged that they did not measure patient dose directly but that air karma was measured between the two groups and was similar.
He added that patient exposure is infrequent while operators face potential exposure routinely in their work. “These are protective, simple measures we can all use and can be easily incorporated into medical practice,” he said.