No abstract

Background: The risks of ionizing radiation to patients and physicians from radiographic procedures are a significant concern. Radiation is essential for the performance of cardiac catheterization and angioplasty but exposure should be minimized. Because it cannot be sensed and the effects may be delayed, radiation exposure must be measured and critically reviewed. Methods: The procedure volume, personal radiation exposure of interventional cardiologists at Stony Brook University Hospital was reviewed for 10 months from 1-10/11. The sensitivity of 3 measures of patient exposure: total dose (Kerma area product = P ka ), fluoroscopy time and skin dose were compared and the deep dose exposure of physicians was correlated with the number of incidents exceeding lab benchmarks for patient reportable excess radiation exposure. Results: During the monitored period a total of 1,978 cardiac catheterizations and 1,324 angioplasties [PCI] (>90% ad hoc) were performed by 14 interventional cardiologists. PCI volume averaged 94.6±54.6/ physician (range 28-180) and 40% of total lab volume (with ad hoc conversion rates from diagnostic catheterization ranging from 24% [72/303] -54% [180/332]). The average total deep dose/ physician was 787.5±710.6 mRem (high of 2,840). There were 187 incidents of total dose exceeding our benchmark of >20,000 microGray m 2 (14.1% [187/1,324] of PCI; 41 cases were > 30,000 and the highest procedural dose was 52,562). Excess fluoroscopy time (>60 minutes) was present in 5% (9/187) and excess skin dose (>5,000 milliGray) in 24% (12/51) of reportable cases of excessive total dose. Total and PCI volumes had Pearson correlation coefficients of 0.61 and 0.71 respectively with deep dose and 0.54 and 0.64 with patient total dose. Physician deep dose exposure had the best correlate (0.89) with reportable cases of patient exposure. Lifetime physician deep dose reflected case volume and years of practice, but exposure also varied markedly by physician, with average annual accumulations (mean 1,120.6 mRem/yr) ranging from 67 mRem/yr to 4,451.1 mRem/yr (the latter expected to limit the physician's cath lab career to an additional 6 years at the current rate of accumulation based on maximal allowable lifetime dose). Conclusions: The high variability in operator exposure suggests significant variations in technique which should be further explored. Of the routine measures of exposure, the total dose is the most sensitive indicator of patient exposure. Operator and patient exposures are highly correlated. The high number cases exceeding benchmarks provide an opportunity for further drill down and procedural changes to optimize the risk/benefit ratio for both patients and operators.