DLP/ED conversion coefficients are provided for lower extremities and allow estimation of ED for commonly used clinical musculoskeletal CT and CT angiographic protocols.

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Although computed tomography (CT) scan radiation dose has drawn much attention, radiation dose from nuclear medicine procedures should not be overlooked. An estimated 19.7 million nuclear medicine procedures are done annually in the United States, with patient radiation dose comparable to that from CT scans. Nuclear medicine departments should implement Image Gently SM and Image Wisely SM recommendations to reduce nuclear medicine patient radiation dose. Pediatric administered radiopharmaceutical doses should be compared with the North American Consensus Guidelines for Administered Radiopharmaceutical Activities in Children and Adolescents, and adult doses should be compared with national and international standards. In a 2011 patient quality and safety initiative at Gundersen Lutheran Health System, 24 pediatric protocols and 52 adult protocols were compared with standards. Doses not comparable to the recommended values were adjusted accordingly and the resultant image quality evaluated. Additional steps to reduce patient radiation dose include decision support to reduce inappropriate ordering, technique optimization for the CT portion of single-photon emission computed tomography/computed tomography and positron emission tomography/computed tomography scans, use of vendor's dose reduction camera and software technology, use of shorter lived radiopharmaceuticals, and "right sizing" patient doses by weight.

Radioactive seed localization procedures, using 125I seeds of typical activity 3.7 MBq and higher, are performed to localize nonpalpable lesions in the breast for surgical excision and pathology analysis. This study evaluated the use and dosimetry of 125I seeds of activity <3.7 MBq in radioactive seed localization procedures through retrospective health record review, Monte Carlo simulation, and experimental detection. An average seed strength at the time of specimen excision of 2.48 ± 0.629 MBq was used in 295 radioactive seed localization procedures at Gundersen Health System in La Crosse, Wisconsin, US. The average explanted seed activity served as a basis for Monte Carlo simulation of an 125I IsoAid Advantage seed embedded in soft tissue, which scored the dose deposited to soft tissue. Tabulated values of the dose to postsurgical residual tissue as a function of explanted tumor radius were shown and compared with previously published results. Use of seeds of activity from 1.44 to 3.7 MBq at the time of excision did not adversely affect seed detection and excision. The absorbed dose to residual tissue calculated using Monte Carlo was an average of 1.4 times larger than previously published results when scaled to identical seed strengths. This study demonstrates that seeds of activity <3.7 MBq can be used for radioactive seed localization procedures with no loss in efficacy and a benefit of reduced radiation dose to patients. This is important because the estimated radiation dose to residual tissue is approximately 1.4 times higher than previously indicated.