Annual chest radiographs do not reduce lung cancer deaths

 The latest issue of the Journal of American Medical Association contains a detailed study which demonstrated that  annual screening with chest radiograph did not reduce lung cancer mortality compared with usual care.
You can access the paper at
http://jama.ama-assn.org/content/306/17/1865.abstract?etoc

It will be very useful to read the editorial on the topic in the same issue of the journal. It can be accessed at:

http://jama.ama-assn.org/content/306/17/1916.full

Any  medical x-ray procedure which does not benefit the patient must be considered as unwanted

CT radiation dose report released by American Association of Physicists in Medicine

The importance of reducing hte dose to patients from CT scans has attracted the attention of specialists for thje past few years. The present report is the result of such effort by American Association of Physicists in Medicine.

K.S.Parthasarathy




Public release date: 15-Feb-2008
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Contact: Jason Socrates Bardi
jbardi@aip.org
301-209-3091
American Institute of Physics
CT radiation dose report released by American Association of Physicists in Medicine
Promotes best image quality with least radiation dose

College Park, MD (February 15, 2008) -- Aiming to promote the best medical imaging practices nationwide and help ensure the health and safety of the millions of people who undergo computed tomography (CT) scans each year in the United States, the American Association of Physicists in Medicine (AAPM) has issued a CT radiation dose management report this month recommending standardized ways of reporting doses and educating users on the latest dose reduction technology.

AAPM is the premiere professional association of medical physicists and includes both scientists and board-certified health professionals who care for patients.

Targeted at radiologists, medical physicists, and other medical professionals, the report outlines the best ways to measure, manage, and prescribe radiation dosages. It also gives an overview of ways that doctors can optimize modern CT scanners to get the most bang for the buck -- reducing to a bare minimum the amount of radiation to which patients are exposed while still allowing them to benefit from the technique's life-saving ability to image inside the human body.

"The medical applications of CT have grown tremendously in the last decade as the technology had become more and more sophisticated," says Mayo Clinic Medical Physicist Cynthia McCollough, who was chair of the AAPM Task Group that authored the report. "In the era of increasingly personalized medicine, the report provides a roadmap for doctors and medical physicists to tailor the CT radiation dosages to individuals."

The report was generated by a committee of medical physicists with special expertise in CT technology and its clinical uses. It can be downloaded from the AAPM website (see: http://www.aapm.org/pubs/reports/RPT_96.pdf).

CT SCANS AND RADIATION

The benefits of CT scans are enormous, and the technology has revolutionized medicine in the last generation because it can provide cross-sectional snapshots deep inside someone's body with unprecedented clarity. These images help doctors diagnose unseen illnesses and injuries, and they guide treatment for millions of people a year in the United States.

In the last few years, reports in the medical literature and in the popular press have challenged public perceptions of CT scans by raising questions of risk related to the fact that CT scanners use X rays, which in high doses can damage the DNA inside cells.

However, says McCollough, the benefits of receiving a medically justified CT scan far outweighs the risk associated with the low levels of radiation used. To put this into perspective, the U.S. Food and Drug Administration (FDA) considers the risk of absorbed X rays from CT scans to be very small (see: http://www.fda.gov/cdrh/ct/risks.html).

Even so, the FDA recommends avoiding unnecessary exposure to radiation during medical procedures, especially for children. The FDA published a public health notice in 2001, calling for pediatric CT scans to be tailored to the specific needs and smaller sizes of children and only administered when appropriate (see http://www.fda.gov/cdrh/safety/110201-ct.html).

While they are not regulatory bodies, the AAPM and allied organizations like the American College of Radiology (ACR) play important roles in helping to achieve the FDA’s goal of keeping the radiation dose as low as reasonably achievable, consistent with the medical need, by making recommendations and providing accreditation of CT scan facilities. This is essential because while the FDA is responsible for regulating CT scanning equipment, it does not actually regulate the CT scans themselves. Oversight of the use of X-ray technology in the United States is regulated by individual states' laws.

The ACR plays an important role in guaranteeing the quality and safety of CT scanning through its voluntary accreditation program. To achieve ACR accreditation, CT facilities must demonstrate both clinical and technical competency, as well as meet requirements for staff training and quality assurance. Only sites with sufficient image quality and appropriate radiation doses can receive ACR accreditation. While the program is voluntary, many insurers require that facilities be accredited in order to qualify for reimbursement.

Similarly, the AAPM contributes to the safety and quality of CT imaging by providing reports like the one just published, which gives the most current standards for CT dose measurement techniques and discusses how facilities can reduce radiation dosages by using new technical features that automatically adjust the radiation exposure according to each patient's size.

The information contained in this report is crucial, says McCollough, because it can help medical practitioners take full advantage of sophisticated CT technology. "Essentially, all modern CT systems can be equipped with automatic exposure control systems. These tools help to ensure that no patient receives more radiation dose than they need. We believe that this report equips users to properly describe and manage CT dose levels."

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ABOUT AAPM

The AAPM is a scientific, educational, and professional nonprofit organization whose mission is to advance the application physics to the diagnosis and treatment of human disease. The Association encourages innovative research and development, helps disseminate scientific and technical information, fosters the education and professional development of medical physicists, and promotes the highest quality medical services for patients. In 2008, AAPM will celebrate its 50th year of serving patients, physicians, and physicists. Please visit the Association Web site at http://www.aapm.org/.

ABOUT AIP

Headquartered in College Park, Md., the American Institute of Physics is a not-for-profit membership corporation chartered in New York State in 1931 for the purpose of promoting the advancement and diffusion of the knowledge of physics and its application to human welfare.

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Skin injuries to patients can be avoided when radiation dose is monitored

Radiation dose due to interventional radiology procedures has attracted the attention of specialists for the past several years. Special dedicated radiation protection appreciation programmes will be useful to make specialists aware of the need to reduce radiation doses.

K.S.Parthasarathy



Public release date: 20-Nov-2007
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Contact: Necoya Tyson
necoya@arrs.org
703-858-4304
American Roentgen Ray Society
Skin injuries to patients can be avoided when radiation dose is monitored

Maximum radiation skin dose during coronary angioplasty can be accurately determined by monitoring the total entrance skin radiation dose as the patient is being examined and dividing that number in half according to a recent study conducted by researchers at Tohoku University in Sendai, Japan. By knowing the maximum radiation skin dose, radiologists can avoid skin injury to the patient, the researchers said.

Angioplasty, is a procedure that helps treat narrowed coronary arteries. “Many patients benefit greatly from procedures such as angioplasty, however, a major disadvantage associated with these procedures is patient radiation exposure,” said Koichi Chida, PhD, lead author of the study. “In most cardiac interventional procedures, real-time monitoring of maximum skin dose is not possible,” however monitoring total entrance skin radiation dose is, Dr. Chida said. The study was conducted to determine if total entrance skin dose could help determine maximum radiation dose to the skin.

The study evaluated 194 angioplasty procedures. The researchers investigated the relation between maximum skin dose and total entrance skin dose and found that the maximum skin dose constituted between 48%-52% of the total entrance skin dose during angioplasty. There were significant correlations between maximum skin dose and total entrance skin dose during angioplasty, Dr. Chida said. .

“This study is an important addition to interventionalists’ knowledge and understanding about how to evaluate radiation exposure to their patients,” he said.

###

The full results of this study appear in a recent issue of the American Journal of Roentgenology, published by the American Roentgen Ray Society.

Minimum standards for CT colonoscopy

The American Gastroenterological Association (AGA), an Association in USA with 16,000 members has prescribed minimum standards for physicians carrying out CT colonoscopy. Specialists do not endorse CT colonoscopy to screen asymptomatic patients; it will be useful for those patients unwilling to undergo other screening tests. Let us hope that professional associations in India may arrive at similar standards for prescribing the competence of physicians carrying out this test.

K.S.Parthasarathy



Public release date: 7-Sep-2007
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Contact: Aimee Frank
media@gastro.org
301-941-2620
American Gastroenterological Association
Gastroenterology sets standards for CT colonography

Recognizing that CT colonography will play a role in screening for colorectal cancer (CRC), and the critical need to increase overall CRC screening rates, the American Gastroenterological Association (AGA) Institute issued minimum standards for gastroenterologist performance of the test. To ensure competence, a minimum of 75 endoscopically confirmed cases should be interpreted by the physician.

Despite the fact that CT colonography has not yet been endorsed as a primary screening test in asymptomatic, normal risk adults, many patients have shown interest in this test. The indications for CT colonography are controversial, with many payers recommending that this test only be indicated for patients who have had a failed optical colonoscopy or who have a mass obstructing the colon where examination of the entire colon is required prior to surgical resection. Nonetheless, CT colonography may be considered for patients unwilling to undergo other colorectal screening tests, note the authors of the standards paper, which is published in Gastroenterology, the official journal of the AGA Institute.

“Because of our specialized training, gastroenterologists are experts in CRC screening and colorectal disease. It follows that if patients want a ‘virtual colonoscopy’ it may be highly appropriate to see a qualified gastroenterologist for the test,” notes Don Rockey, MD, AGAF, chair of the AGA Institute Task Force on CT Colonography. “As CT colonography technology is evolving, it is important to check that your physician has been properly trained to ensure that the test is performed and interpreted accurately.”

After formal training, during which at least 75 tests should be interpreted, the AGA Institute Task Force on CT Colonography, which authored the standards paper, recommends that gastroenterologists should participate in a mentored CT colonography preceptorship with the candidate physically present and involved in the interpretation of at least 25-50 additional cases. In addition, it is expected that those performing CT colonography will undertake ongoing training and self assessment including attending formal continuing medical education-accredited courses in CT colonography.

The AGA Institute Task Force on CT Colonography offers the following recommendations. The full recommendations are available in the September issue of Gastroenterology.

Patient Care

* Any polyp > 6 mm in size (i.e., widest diameter) should be reported and the patient referred for consideration of endoscopic polypectomy.

* Patients with three or more polyps of any size in the setting of high diagnostic confidence should be referred for consideration of endoscopic polypectomy.

* The appropriate clinical management of patients with one to two lesions no greater than 5 mm in diameter is unknown. In the absence of data, the follow-up interval recommended for these patients should be based on individual characteristics of the patient and procedure.

Quality Control and Safety

* Practices offering CT colonography should establish a technical quality control program.

* Endoscopic results in patients referred from CT colonography to endoscopy, including true positive and false negative rates, should be tracked.

Regulatory Issues

* Split interpretations of CT colonography are feasible.

* Gastroenterologists and radiologists performing split interpretations should dictate and sign separate procedure reports that clearly state the specific services they performed related to CT colonography.

Exam and Equipment Specifications

* CT colonography should be performed using multidetector CT protocols with high spatial resolution.

* Computer workstations for dedicated CT colonography interpretation should permit 2D and 3D correlation and visualization of the colonic lumen.

* CT colonography images should be archived for later comparison.

* Primary 2D or primary 3D review of the endoluminal surface of the colon and rectum is required.

Guidelines from multiple agencies and professional societies, including the AGA Institute, underscore the importance of colorectal cancer screening for all individuals 50 years of age and older (younger for certain groups known to be at higher risk). The U.S. Preventive Services Task Force, the U.S. Multi-Specialty Task Force, and others have published recommendations for screening for colorectal cancer, the second-leading cause of cancer deaths in the United States. Currently, recommended screening tests include colonoscopy, flexible sigmoidoscopy, barium enema, and fecal occult blood tests.

The AGA Institute formed the CT Colonography Task Force to develop minimum training standards for gastroenterologists in order to provide guidance, and to ensure minimum training competencies are upheld for the performance of the exam. The AGA Institute continues to monitor CT colonography along with other potential colorectal cancer screening tests, and will continue to develop guidance tools and reports as appropriate. The AGA Institute will host a course on CT colonography for gastroenterologists on March 7-8, 2008, in Washington, DC. Additional information will be available this fall.

###

About the AGA Institute

The American Gastroenterological Association (AGA) is dedicated to the mission of advancing the science and practice of gastroenterology. Founded in 1897, the AGA is one of the oldest medical-specialty societies in the United States. Comprised of two non-profit organizations—the AGA and the AGA Institute—our more than 16,000 members include physicians and scientists who research, diagnose and treat disorders of the gastrointestinal tract and liver. The AGA, a 501(c6) organization, administers all membership and public policy activities, while the AGA Institute, a 501(c3) organization, runs the organization’s practice, research and educational programs. On a monthly basis, the AGA Institute publishes two highly respected journals, Gastroenterology and Clinical Gastroenterology and Hepatology. The organization's annual meeting is Digestive Disease Week®, which is held each May and is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. For more information, please visit www.gastro.org.

About Gastroenterology

Gastroenterology, the official journal of the AGA Institute, is the most prominent scientific journal in the specialty and is in the top one percent of indexed medical journals internationally. The journal publishes clinical and basic science studies of all aspects of the digestive system, including the liver and pancreas, as well as nutrition. The journal is abstracted and indexed in Biological Abstracts, CABS, Chemical Abstracts, Current Contents, Excerpta Medica, Index Medicus, Nutrition Abstracts and Science Citation Index. For more information, visit www.gastrojournal.org.

New CR technology boosts resolution, bags R&D award

Improvements in computed technology continue to attract attention.The new development is a new type of storage phosphor material based on a translucent glass-ceramic imaging plate.One of the attractions of the technology is that the image receptor can be substituted at existing equipment without changing the associated x-ray equipment.

K.S.Parthasarathy



Siemens

New CR technology boosts resolution, bags R&D award
9/3/2007
http://www.auntminnie.com/print/print.asp?sec=sup&sub=xra&pag=dis&ItemId=77337&printpage=true


By: Brian Casey

U.S. researchers have developed a new type of computed radiography (CR) technology that they believe could yield much higher resolution than existing CR systems. One prominent scientific magazine thought enough of their research to name it one of the top 100 scientific innovations for 2007.

Computed radiography has made impressive gains in achieving commercial acceptance in the last 25 years, but the fundamental technology behind CR remains the same -- photons produced by an x-ray generator are sent through a patient and captured on a storage phosphor plate that's coated with a powder that typically consists of barium fluorobromide doped with europium. The imaging plate is then taken to a laser scanner, where electrons stored in the plates are converted into light, then read out and converted into digital images.

But some industry observers believe that CR has reached a plateau in terms of improving on this basic design, and as a result its image quality has been surpassed by digital radiography (DR) units based on flat-panel technology, according to a research group that includes scientists from Argonne National Laboratory in Argonne, IL, and the State University of New York (SUNY) at Stony Brook. To improve on CR, the group developed a new type of storage phosphor material based on a translucent glass-ceramic imaging plate.

The SUNY/Argonne technology could offer much higher resolution than current CR systems, and could be used to retrofit existing x-ray rooms in the same way as CR, without requiring a new x-ray generator and other equipment, according to Anthony Lubinsky, who represented SUNY on the research team. Lubinsky is a former employee at Eastman Kodak Health Group (now Carestream Health of Rochester, NY), and has been working on CR technology for the past 20 years.

"It would be as easy to make the switch (to digital) for your x-ray room as it is with CR in the ordinary practice," Lubinsky said. "What's inside the cassette is different and what's inside the scanner box is also different, but to the user it works the same way."

See-through CR?

The heart of the new technology is a CR design developed at SUNY and Argonne National Laboratory that the group calls transparent storage phosphor (TSP). TSP is based on a photostimulable material that employs fluorozirconate rather than barium fluorobromide. Rather than coat an imaging plate with the fluorozirconate, the material is used in combination with europium-doped barium nanocrystals to create a composite glass imaging plate.
Experimental setup of x-ray imaging system for testing fluorochlorozirconate glass-ceramic imaging plates.

The SUNY/Argonne design results in a detector material that's translucent, rather than the opaque powder screen used today with CR. As a result, a point of light entering the imaging plate doesn't scatter as much as it does with conventional imaging plates, resulting in a higher modulation transfer function (MTF). That means that a manufacturer developing a CR system based on the SUNY/Argonne technology could make the imaging plate much thicker than one based on barium fluorobromide or some other type of powder, with correspondingly higher spatial resolution.

How much higher? The group has fashioned imaging plates with a resolution of 17 microns, compared with 70 microns for amorphous selenium-based DR and 100-200 microns for conventional CR, according to Jacqueline A. Johnson of Argonne National Laboratory. The group points out that the 17-micron specification was achieved in a test environment and with a radiation dose that's much higher than would be used clinically.
Phantom image collected with tabletop CR system. Parallel vertical lines represent gold bars at spatial frequencies of 19 line pairs (left) and 20 line pairs (right) per mm. All images courtesy of Argonne National Laboratory.

One of the most obvious applications for the SUNY/Argonne technology in the clinical realm would be mammography, in which CR units based on conventional technology are entering clinical use in the U.S. after the Food and Drug Administration's 2006 approval of the first CR mammography unit, from Fujifilm Medical Systems USA of Stamford, CT. Argonne's technology could give mammographers an even finer level of detail than conventional CR.

But the Argonne team believes that its technology could have a wide range of applications in medical imaging. "If it works for mammography, I would hope the resolution would be helpful in the extremities as well," Lubinsky said.

However, you won't see the SUNY/Argonne technology in a commercially available CR system anytime soon. At present, the group has built a tabletop system and collected phantom images, and their next step is to develop a working prototype. The research team estimates that it could be more than five years before the technology hits clinical users, due to the vagaries of technology development and the need to move such a system through the FDA approval process.

If the technology does make it into the commercial marketplace, it wouldn't be totally plug-and-play with existing CR systems. Although the technology could be used with existing x-ray generators and gantries, the TSP plates would require specially adapted scanners for reading the plates, according to Lubinsky.

But the SUNY/Argonne's team work was promising enough to catch the attention of R&D Magazine, which named the research one of the top 100 scientific innovations of 2007, based on the group's March 2007 paper in the Journal of the American Chemical Society (Vol. 90:3, pp. 693-698). The award will be announced in the magazine's September issue.

The development of a translucent CR imaging plate is not a new idea: "It's something that people have thought of as a great idea if you could do it," Lubinsky said. But the SUNY/Argonne group's major achievement has been in developing both a translucent imaging plate and the concept of a laser scanner to read out the images.

"The trick is to get the (TSP and readout technologies) working together so well," he said.

By Brian Casey
AuntMinnie.com staff writer
September 3, 2007

Related Reading

PACS data-mining technique tackles CR dose creep, July 30, 2007

DICOM-compliant displays aid CR/DR exposure control, July 17, 2007

CR/DR image quality: Issues and concerns, April 12, 2007

Strategies for reducing 'dose creep' in digital x-ray, April 11, 2007

Study suggests ways to cut CR radiation, March 5, 2007

Copyright © 2007 AuntMinnie.com

Ways to cut radiation dose in computed tomography

Any one who is involved in radiological protection cannot ignore the development which involves reduction in radiation doses in computed tomography (CT).CT examinations are exposing patients to doses in the range in which the survivors of atomic bombings suffered excess cancers.

K.S.Parthasarathy

Siemens

Study suggests ways to cut CR radiation
3/5/2007
http://www.auntminnie.com/print/print.asp?sec=sup&sub=xra&pag=dis&ItemId=74868&printpage=true

By: Leanne McKnoulty

A new study by Australian researchers has found that the radiation dose delivered in computed radiography (CR) examinations could be cut in half by adjusting the manufacturers recommended range (MRR) for exposure indices (EIs) by as little as 10%.

The arrival of CR has given radiographers (radiologic technologists) the ability to use a greater range of radiation exposures to produce diagnostic images, the article states. Because, unlike film-screen radiography, higher-than-appropriate exposures in CR result in better-quality images due to increased signal-to-noise ratio, and "radiographers develop a tendency to use higher than necessary exposure factors to improve image quality and avoid repeat radiographs."

To safeguard against overexposure, CR manufacturers each set their own exposure indicators -- numerical parameters that are estimates of radiation exposure on imaging plates. The feature is called EI on systems manufactured by Eastman Kodak Health Group of Rochester, NY, and sensitivity value (S) on units made by Fujifilm Medical Systems of Tokyo.

Dr. Helen Warren-Forward and colleagues at the University of Newcastle set out to explore whether radiographers were in fact producing images using EIs within the MRR. They also sought to investigate any evidence of "exposure creep," and the relationship between EIs and radiation dose using fixed and varying tube potential, in the hope that this knowledge would ensure the use of techniques that minimize radiation dose. The study was published in the British Journal of Radiology (January 2007, Vol. 80:949, pp. 26-31).

The researchers retrospectively assessed CR data for posteroanterior (PA) chest and lateral (LAT) lumbar spine imaging, from two hospitals, denoted as hospital A and hospital B, using the CR-800 and CR-850 systems (Eastman Kodak), during an 18-month period from January 2004.

The researchers selected PA chest data because, in Australian hospitals, this is the most frequently performed examination. LAT lumbar spine data were selected because the researchers felt this represented a high entrance surface dose examination. Also, these two examinations provided a contrast in exposure factors, body part, and positioning technique, they stated.

Although manufacturers of CR equipment recommend certain "exposure indicators," the researchers highlighted that higher tube potentials and lower mAs reduce patient radiation dose compared with lower tube potentials and higher mAs. "Therefore, it cannot be assumed that there is a good correlation between exposure index and patient doses," they wrote.

Using a lung/chest phantom (model CNR/R5330, Oxford Scientific, Silverwater, Australia), the researchers showed that for a fixed tube potential (125 kVp), without any change in other parameters, EI correlates with entrance-surface dose (ESD) -- there is a log relationship in dose and EI in CR. So, a small increase in EI results in a large increase in ESD. Additionally, the researchers investigated the relationship among a varied tube potential, EI, and patient dose. They found that an increasing tube potential and a decreasing mAs for a constant EI (1500) resulted in decreasing ESD.

"The results from this current study strongly suggest that EI should not be used as an indication of ESD when comparing examinations conducted between different radiographers and institutions using different tube potentials," they wrote.

The authors caution that, particularly for chest imaging, a number of factors can affect patient dose, in particular tube potential. Therefore, EI should only be used to indicate ESD for examinations within a specific department performed by the same radiographers. They found no significant variation in EIs when they compared CR imaging during normal operational hours with after-hours services.

EIs lower than the MRR, 1700-1900 for Kodak CR systems, were successfully used for 30% of LAT lumbar spine examinations at hospital B and 38% of PA chest examinations at hospital A. "This implies that the MRR may be set too high and can be reduced to values less than 1700," they wrote.

More than two-thirds of PA chest examinations performed at hospital B, but less than one-third at hospital A, were produced with EIs within the MRR. Almost half of LAT lumbar spine examinations performed at hospital B were produced with EIs within the MRR, but almost half at hospital A were above the MRR.

Using the lung/chest phantom to produce suitable diagnostic images, EIs were 1550. The researchers suggest that since a reduction in EI by 300 results in half the patient dose, reducing MRR values from 1770-1900 to 1530-1700 (a 10% reduction) would result in significant dose savings (50%).

Exposure creep was described by the researchers as a tendency by radiographers to set higher exposures than necessary, knowing that images could be manipulated with postprocessing techniques, to achieve a suitable diagnostic image.

Results demonstrated exposure creep at hospital A, where exposure indices for LAT lumbar spine CR increased 7.1% during the 18-month period. Hospital A also showed a larger range of EIs, probably due to a higher number of patients and staff, resulting in greater variation in radiographic technique, which impacts the EI levels used to produce images, the authors suggested.

The study findings highlight the need for regular staff training on the appropriate use of CR systems and departmental quality assurance programs to ensure staff adopt the ALARA principle, to keep patient doses "as low as reasonably achievable," the researchers stated. They suggested that CR manufacturers should review the acceptable range of EIs recommended.

"The results showed that an EI of 2000 produced at 125 kVp can deliver the same patient dose as an EI of 1700 produced at 70 kVp, where the EI difference of 300 represents a doubling of dose to the detector," they wrote. "EI cannot always be used as an indicator of changes to patient dose, but that a number of other factors (predominately tube potential) need to be considered."

By Leanne McNoulty
AuntMinnie.com contributing writer
March 5, 2007

Related Reading

Korean rads find no edge for high-res CR in chest exams, January 22, 2007

Study: DR delivers lower radiation dose, November 7, 2006

U.S. hospitals find ways to take the digital x-ray plunge, October 12, 2006

AuntMinnie's IMV MarketStat #44: Percentage of U.S. hospitals with DR or CR technology, October 9, 2006

Digital radiography slowly, but surely, makes its mark, July 25, 2006

Copyright © 2007 AuntMinnie.com

Informational hand out on computed tomography to parents

Since computed tomogaphy exposes patients to significant radiation doses, physicians must use them after due consideration.They must carry out CT tests only if they are clinically indicated.Children are more sensitive to radiation so use of CT for pediatric examination must receive more attention.

Dr.K.S.Parthasarathy



Contact: Necoya Lightsey
necoya@arrs.org
703-858-4304
American Roentgen Ray Society
Informational handout key to giving parents a better understanding of CT radiation risks

Simply giving parents informational handouts can improve their understanding of the potential increased risk of cancer related to pediatric CT, according to a recent study conducted by researchers from The Children’s Hospital in Denver, CO and Yale University School of Medicine in New Haven, CT.

“Like many radiology departments around the country, we are concerned about the increasing radiation exposure to children caused by increased usage of CT. When we looked into it, our emergency physicians told us that parents' expectations may play a role,” said David B. Larson, MD, lead author of the study. “The emergency room clinicians tell us anecdotally that a number of parents expect that their child will undergo CT even before the child is seen by a physician. Parents rarely seem to understand the associated risks, so we thought it might be helpful to our emergency room colleagues to provide a handout to parents to explain, in basic terms, the risks associated with CT,” said Dr. Larson.

The study consisted of 100 parents of children undergoing non-emergent CT studies who were surveyed before and after reading an informational handout that described radiation risks. Of the 100 parents surveyed, 66% believed that CT uses radiation; 99% afterwards. 13% of those surveyed before reading the handout believed CT increases the lifetime risk of cancer, versus 86% surveyed afterward.

According to the study, after reading the handout, parents became less willing to have their child undergo a CT examination if their doctor believed that either CT or observation would be equally effective. Their willingness to have their child undergo CT recommended by their doctor did not significantly change. No parent refused or requested to defer CT after reading the handout.

“While most parents knew that CT uses radiation, we were surprised to find that most parents did not realize that this radiation exposure is associated with an increased risk of cancer,” said Dr. Larson.

“While we were working on the handout, we found it extremely difficult to find meaningful estimates of exposure, dose, and risk for various types of procedures--even in the radiology literature. It is then not surprising that not only do parents underestimate the risk, but so do clinicians and radiologists,” he said. “When addressing the question of ‘how much does a CT increase the risk of cancer"” rather than providing a meaningful basis of comparison, most publications give one of two responses; either ‘the risk is slight’ or ‘it depends.’ While both may be accurate, neither are very helpful,” he said.

“Even though risk estimates are fraught with uncertainty, a reasonable quantitative estimate is an improvement upon ‘slight’,” said Dr. Larson. “If radiologists expect clinicians to have these discussions with their patients, then we need to do a better job discussing this subject amongst ourselves and with clinicians. We believe such information should be straightforward, accurate, and widely available,” he said.
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The full results of this study appear in the August issue of the American Journal of Roentgenology, published by the American Roentgen Ray Society.

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