Impact of Protocol Change in the Cardiac Cath Lab
L Page*, G Tomakin, A Jones, MD Anderson Cancer Center, Houston, TXPO-BPC-Exhibit Hall-10 Saturday Room: Exhibit Hall
Purpose: To quantify the impact on dose to patients and personnel in the cardiac cath lab as a result of increasing the dose per frame for cine acquisition from 0.17 to 0.24 microGy/frame at the request of a physician.
Methods: Reports containing the dose area product (DAP) and reference air kerma (Ka,r) for patients who underwent left heart catheterization (LHC, n = 184) and right and left heart catheterization (RLHC, n = 100) procedures on a biplane Siemens Artis Zee were collected. Dose metrics from procedures performed before and after the protocol change were compared. Occupational dose reports were also analyzed.
Results: After the protocol change, the DAP and Ka,r increased by 3% and 4%, respectively, for LHC. These changes were not significant (P = 0.881, 0.851). The DAP and Ka,r for RLHC increased significantly by 59% and 64% (P < 0.001 for both). These increases were greater than expected based on the change made to the protocol. A review of fluoroscopy time (FT) data revealed that FT for LHC was the same before and after the change, while FT for RLHC increased significantly (35%, P = 0.008). Occupational dose data were of limited utility because of inconsistent use of radiation badges.
Conclusions: Patient dose metrics increased for RLHC procedures but did not increase for LHC procedures after increasing the dose per frame for cine. The constancy of LHC dose metrics may have resulted from a reduction in the number of cine runs acquired owing to improved image quality after the change. The increase in FT for RLHC indicated that another factor was affecting dose metrics, perhaps related to the skill of physicians or the complexity of cases, this is under investigation. It was not possible to assess the impact on occupational dose owing to inconsistent use of radiation badges.