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ISSUES IN DIAGNOSTICS
Radiation doses used in radiation therapy are much higher than doses used in diagnostic radiography; but because radiation poses a stochastic as well as a dose-dependent risk of harm, diagnostic imaging is nevertheless receiving increasing scrutiny as a source of avoidable and therefore unjustified patient irradiation. CT procedures, in particular, can involve radiation doses 100 times those of simple chest radiographs.8
The Food and Drug Administration (FDA) called for hospitals to review safety and calibration protocols for CT scans in 2009 following the discovery that more than 200 patients at a California hospital with suspected stroke were exposed to CT radiation overdoses up to 800% of the intended dose.8 More than 80 of those patients experienced radiation skin burns, hair loss, and increased risk of cataract.8 Human error and failure to implement quality assurance protocols were at fault; however, the FDA announced new regulations in 2010 and 2011 for manufacturers, importers, and hospitals to reduce medical irradiation from CT and nuclear medicine examinations with the goal of eliminating unnecessary scans and ensuring optimization of justified diagnostic imaging.12,13
An estimated 3.6 billion diagnostic radiology procedures are undertaken worldwide every year, and 500 million are conducted in the United States.5 Most diagnostic imaging is medically justified, with overriding benefits for patients. However, up to 37% of abdominal CT scans and 77% of lumbar spine CT scans prescribed at some European facilities for patients younger than 35 years were found to be medically unjustified.14
Medically unnecessary CT scans are prescribed for up to 20 million American adults and 1 million children each year.7 A 2007 analysis concluded that up to 2% of cancers diagnosed in the United States may be attributable to CT examinations.7 The justification of any radiological imaging must always be scrutinized, particularly in pediatric cancer patients, for whom any radiation poses a larger lifetime risk for secondary cancer than for older cancer patients. The availability and sufficiency of alternative imaging modalities that do not involve ionizing radiation, such as magnetic resonance imaging (MRI), should always be considered.5,8 Despite numerous calls for electronic medical records (EMRs) to include cumulative radiation dose information, only a handful of US hospitals and medical groups have adopted such systems to date.8 ONA
Bryant Furlow is a medical writer based in Albuquerque, New Mexico.
REFERENCES
1. Lie JA, Kjaerheim K, Tynes T. Ionizing radiation exposure and cancer risk among Norwegian nurses. Eur J Cancer Prev. 2008;17(4):369-375.
2. Doody MM, Freedman DM, Alexander BH, et al. Breast cancer incidence in U.S. radiologic technologists. Cancer. 2006;106(12):2707-2715.
3. Bogdanich W. At V.A. hospital, a rogue cancer unit. The New York Times. June 20, 2009. http://www.nytimes.com/2009/06/21/health/21radiation.html?pagewanted=all. Accessed November 23, 2011.
4. Furlow B. Radiotherapy errors spark investigations and reform. Lancet Oncol. 2009;10(1):11-12.
5. Chhem RK, Meghzifene A, Czarwinski R, et al. Towards better and safer use of radiation in medicine. Lancet. 2010;375(9723):1328-1329.
6. Lau LS. Leadership and management in quality radiology. Biomed Imaging Interv J. 2007;3(3):e21. www.biij.org/2007/3/e21/e21.pdf. Accessed November 23, 2011.
7. Brenner DJ, Hall EJ. Computed tomography —an increasing source of radiation exposure. N Engl J Med. 2007;357(22):2277-2284.
8. Furlow B. Radiation dose in computed tomography. Radiol Technol. 2010;81(5):437-450.
9. Moran JM, Dempsey M, Eisbruch A, et al. Safety considerations for IMRT: executive summary. Pract Radiat Oncol. 2011;1(3):190-195. www.practicalradonc.org/article/S1879-8500(11)00162-7/fulltext. Accessed November 23, 2011.
10. Boadu M, Rehani MM. Unintended exposure in radiotherapy: identification of prominent causes. Radiother Oncol. 2009;93:609-617.
11. Furlow B. When is IMRT the right treatment for prostate cancer? Oncology Nurse Advisor. 2011;2(2):29-30.
12. US Food and Drug Administration. Initiative to reduce unnecessary radiation exposure from medical imaging. February 2010. www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM200087.pdf. Accessed November 23, 2011.
13. Letter to industry about import entry review process (September 6, 2011). US Food and Drug Administration Web site. www.fda.gov/MedicalDevices/ResourcesforYou/Industry/ucm271180.htm. Accessed November 23, 2011.
14. Oikarinen H, Meriläinen S, Pääkkö E, et al. Unjustified CT examinations in young patients. Eur Radiol. 2009;19(5):1161-1165.
