Surgeon radiation dose during complex endovascular procedures.

BACKGROUND

Surgeon radiation dose during complex fluoroscopically guided interventions (FGIs) has not been well studied. We sought to characterize radiation exposure to surgeons during FGIs based on procedure type, operator position, level of operator training, upper vs lower body exposure, and addition of protective shielding.

METHODS

Optically stimulable, luminescent nanoDot (Landauer, Inc, Glenwood, Ill) detectors were used to measure radiation dose prospectively to surgeons during FGIs. The nanoDot dosimeters were placed outside the lead apron of the primary and assistant operators at the left upper chest and left lower pelvis positions. For each case, the procedure type, the reference air kerma, the kerma-area product, the relative position of the operator, the level of training of the fellow, and the presence or absence of external additional shielding devices were recorded. Three positions were assigned on the right-hand side of the patient in decreasing relative proximity to the flat panel detector (A, B, and C, respectively). Position A (main operator) was closest to the flat panel detector. Position D was on the left side of the patient at the brachial access site. The nanoDots were read using a microSTARii medical dosimetry system (Landauer, Inc) after every procedure. The nanoDot dosimetry system was calibrated for scattered radiation in an endovascular suite with a National Institute of Standards and Technology traceable solid-state radiation detector (Piranha T20; RTI Electronics, Fairfield, NJ). Comparative statistical analysis of nanoDot dose levels between categories was performed by analysis of variance with Tukey pairwise comparisons. Bonferroni correction was used for multiple comparisons.

RESULTS

There were 415 nanoDot measurements with the following case distribution: 16 thoracic endovascular aortic repairs/endovascular aneurysm repairs, 18 fenestrated endovascular aneurysm repairs (FEVARs), 13 embolizations, 41 lower extremity interventions, 10 fistulograms, 13 visceral interventions, and 3 cerebrovascular procedures. The mean operator effective dose for FEVARs was higher than for other case types (P < .03), 20 μSv at position A and 9 μSv at position B. For all case types, position A (9.0 μSv) and position D (20 μSv) received statistically higher effective doses than position B (4 μSv) or position C (0.4 μSv) (P < .001). However, the mean operator effective dose for position D was not statistically different from that for position A. The addition of the lead skirt significantly decreased the lower body dose (33 ± 3.4 μSv to 6.3 ± 3.3 μSv) but not the upper body dose (6.5 ± 3.3 μSv to 5.7 ± 2.2 μSv). Neither ceiling-mounted shielding nor level of fellow training affected operator dose.

CONCLUSIONS

Surgeon radiation dose during FGIs depends on case type, operator position, and table skirt use but not on the level of fellow training. On the basis of these data, the primary operator could perform approximately 12 FEVARs/wk and have an annual dose <10 mSv, which would not exceed lifetime occupational dose limits during a 35-year career. With practical case loads, operator doses are relatively low and unlikely to exceed occupational limits.