Unprotected Operator Eye Lens Doses in Oncologic Interventional Radiology Are Clinically Significant: Estimation from Patient Kerma-area-product Data

PURPOSE: To correlate operator lens dose to patient-delivered kerma-area-product (P-KA) to evaluate the usefulness of P-KA as a surrogate for operator eye dose if collar monitor readings are unavailable or deemed unreliable, and to evaluate if unprotected lens dose is clinically significant. MATERIALS AND METHODS: A retrospective review of peak skin doses for consecutive interventional radiology procedures performed during 2006 that had P-KA estimates recorded was performed. Unshielded operator lens dose equivalents (LDE) were obtained from dosimetry monitors worn outside the collar shield of operating interventional radiologists. Operator LDE were correlated with patient P-KA. RESULTS: Average LDE for 2006 was 35.7 mSv +/- 32.7 (range 5.2-89.9 mSv). Patient-delivered P-KA correlated directly with LDE, where 1 Gy cm(2) to the patient resulted in an average of 4.2 mu Sv to the unprotected eyes of the primary operator (r(2) = 0.7). CONCLUSIONS: P-KA may be useful as a surrogate measure of operator LDE if collar monitor readings are unavailable or deemed unreliable. For this study, the dose-effect threshold for cataract formation could be surpassed for some physicians within 11 years if lens dose-mitigating strategies are not routinely employed.