Significant reduction in dental cone beam computed tomography (CBCT) eye dose through the use of leaded glasses R. Prins, MS, PhD, a,b L. T. Dauer, PhD, a D. C. Colosi, DDS, PhD, c B. Quinn, MS, a N. J. Kleiman, PhD, b G. C. Bohle, DDS, d B. Holohan, a A. Al-Najjar, DMD, e T. Fernandez, MS, f M. Bonvento, MS, f R. D. Faber, DDS, MS, e H. Ching, MS, a and A.D. Goren, DMD, c New York and Stony Brook, New York MEMORIAL SLOAN-KETTERING CANCER CENTER, COLUMBIA UNIVERSITY AND STATE UNIVERSITY OF NEW YORK Objective. In light of the increased recognition of the potential for lens opacification after low-dose radiation exposures, we investigated the effect of leaded eyeglasses worn during dental cone-beam computerized tomography (CBCT) procedures on the radiation absorbed dose to the eye and suggest simple methods to reduce risk of radiation cataract development. Study design. Dose measurements were conducted with the use of 3 anthropomorphic phantoms: male (Alderson radiation therapy phantom), female (CIRS), and juvenile male (CIRS). All exposures were performed on the same dental CBCT machine (Imtec, Ardmore, OK) using 2 different scanning techniques but with identical machine parameters (120 kVp, 3.8 mA, 7.8 s). Scans were performed with and without leaded glasses and repeated 3 times. All measurements were recorded using calibrated thermoluminescent dosimeters and optical luminescent dosimetry. Results. Leaded glasses worn by adult and pediatric patients during CBCT scans may reduce radiation dose to the lens of the eye by as much as 67% (from 0.135  0.004 mGy to 0.044  0.002 mGy in pediatric patients). Conclusions. Leaded glasses do not appear to have a deleterious effect on the image quality in the area of clinical significance for dental imaging. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:502-507) Cone-beam computerized tomography (CBCT) is be- coming a widely used imaging tool in many dental facilities. 1-3 CBCT units offer excellent bone image resolution and are lighter in weight, less expensive, and designed to have a smaller operating “footprint” than multidetector CT (MDCT) machines. CBCT scanners offer 3-dimensional (3D) diagnostic information with better spatial resolution and less distortion than pan- oramic radiography machines. More importantly, from the point of view of patient safety, CBCT differs from MDCT in the shape of the x-ray beam and number of rotations and typically results in lower radiation expo- sures. 4 CBCT uses a cone-shaped x-ray beam rather than the typical fan-shaped x-ray beam used in MDCT. The CBCT’s detector rotates, along with the x-ray source, once around a patient’s head, and a computer algorithm converts the series of 2-dimensional basic images into a 3D reconstruction. Depending on ma- chine type and manufacturer, typical scanning times range from 10 to 40 seconds. CBCT units are primarily designed to demonstrate osseous structures as opposed to soft tissue anatomy. They are commonly used to image dental impactions, maxillofacial skeletal and dental discrepancies, assess- ment of facial trauma, and tumors. 5 Dental CBCT units are also increasingly used in treatment planning for dental implants, and orthognathic and general maxillo- facial surgery. Although there are no current standard- izations for CBCT dosimetry, and there is no consensus among dental and medical physics health professionals regarding patient- or organ-specific radiation doses in dental CBCT imaging procedures, 6 there is a European project (www.sedentexct.eu) in place seeking to ad- dress this issue. Additionally, effective doses can vary by orders of magnitude when different machine mod- els, systems, and manufacturers are compared. 7 It is important to justify all uses of ionizing radiation in health care and, when appropriate, maintain image quality while reducing radiation doses as low as rea- a Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York. b Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York. c Department of General Dentistry (Radiology), School of Dental Medicine, State University of New York, Stony Brook. d Department of Oral Surgery, Memorial Sloan-Kettering Cancer Center. e Department of Orthodontics and Pediatric Dentistry, School of Den- tal Medicine, State University of New York, Stony Brook. f Department of Radiology, Stony Brook University Hospital, State University of New York, Stony Brook. Received for publication Jan 18, 2011; returned for revision Mar 23, 2011; accepted for publication Apr 14, 2011. 1079-2104/$ - see front matter © 2011 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2011.04.041 502