Status of NCRP Scientific Committee 1‐23 Commentary on Guidance on Radiation Dose Limits for the Lens of the Eye

Abstract

Previous National Council on Radiation Protection and Measurements (NCRP) publications have addressed the issues of risk and dose limitation in radiation protection and included guidance on specific organs and the lens of the eye (NCRP 1987, 1989, 1993a, 1993b, 1995a, 1995b, 2000b, 2001b, 2010a, 2010b, 2013). NCRP decided to prepare an updated commentary intended to enhance the previous recommendations provided in these earlier reports. NCRP Scientific Committee 1-23 (SC 1-23) (NCRP 2015) is charged with preparing a commentary that will evaluate recent studies on the radiation dose response for the development of cataracts, and also consider the type and severity of the cataracts as well as the dose rate; provide guidance on whether existing dose limits to the lens of the eye should be changed in the United States; and suggest research needs regarding radiation effects on and dose limits to the lens of the eye. A status of the ongoing work of SC 1-23 was presented at the NCRP 2015 Annual Meeting, “Changing Regulations and Radiation Guidance: What Dose the Future Hold?” The following represents a synopsis of a few main points in the current draft commentary. It is likely that several changes will be forthcoming as SC 1-23 responds to subject matter expert review and develops a final document, expected later in 2015.

Biological basis of radiation protection needs rejuvenation

“…The new NCRP report asks for additional research and longer follow-up of those exposed to radiation. (Dauer et al 2016;NCRP 2016). This development is emphasizing the need for more research to set improved dose limits for the public.…”

Radiobiology in Cardiovascular Imaging

“…Although this recommended lens-of-eye dose limit has not yet been implemented in the United States, the Electric Power Research Institute (EPRI) recently reviewed the available epidemiologic literature (47) and the National Council on Radiation Protection and Measurement (NCRP) is preparing an updated commentary addressing the issues of risk and dose limitation in radiation protection and including guidance on the lens of the eye (48). At the same time, various shielding strategies have been investigated to evaluate their impact in reducing the eye dose in fluoroscopy (48–53). For example, using an anthropomorphic phantom and a miniature solid-state dosimeter positioned at the phantom’s eye, Thornton et al (51) evaluated the impact of common shielding strategies, used alone and in combination, on the scattered dose to the fluoroscopy operator’s eye.…”

NCRP Program Area Committee 1

“…In discussion, PAC 1 considered the recommended dose-limit changes particularly noting that while cataracts seem to be benign because surgery can easily repair the problem, for those doing close work, the surgery is often not optimal and sometimes surgery is not successful. Papers summarizing this work have recently been published (Dauer et al 2016, 2017). …”