Radiation exposure from computed tomography (CT) and other medical sources has drawn considerable media attention in recent years. Stories warning of the dangers often focus on the lifetime risk estimates of radiation-induced cancer from repeat examinations. This approach has limitations, said Pari V. Pandharipande, M.D., M.P.H., abdominal and genitourinary imaging specialist at Massachusetts General Hospital and Harvard Medical School in Boston, especially in regard to clinical decision making.
Physicians often order imaging exams to diagnose, treat or monitor life-threatening conditions. The immediate or near-term risk of death from the condition should be taken into account when weighing the benefits of an exam against a potential future risk of radiation-induced cancer from imaging.
"This must be considered when physicians make imaging decisions for their patients, because the timing of risks changes their relevance," Dr. Pandharipande said. "Risks incurred later in life are not the same as those faced in the present. If you had to choose between the chance of incurring a serious risk now or later in life, most people would choose the latter."
Dr. Pandharipande and colleagues recently used CT radiation dose data and mathematical models to better understand the risk-benefit dynamic of medical radiation. They projected outcomes for testicular cancer patients who undergo CT surveillance in the decade after orchiectomy, or removal of the testicle.
"Testicular cancer affects younger men, and patients treated for early-stage cancer receive several CT scans during surveillance," Dr. Pandharipande said. "These patients do very well, but they have a greater risk of radiation-induced cancer later in life."
Based on the results of their analysis, the researchers projected that 33-year-old men with early-stage cancer who undergo CT surveillance incur a slightly higher lifetime mortality risk from testicular cancer compared with potential radiation-induced cancers. Because the testicular cancer risk was more immediate, life expectancy loss attributable to testicular cancer was more than three times greater than life expectancy loss attributable to radiation-induced cancers.
The trends were consistent across all the scenarios studied, and put forth a useful concept to help physicians with decision making.
"Radiation-induced cancer risks, often discussed at the population level, can be challenging to conceptualize and apply to imaging decisions that have to be made at the patient level," Dr. Pandharipande said. "We as physicians can benefit from dedicated educational efforts to improve decision making and better convey the risks to patients."
Although the study focused on testicular cancer patients, concepts pertaining to the timing of radiation-induced cancer risk translate to other scenarios where CT is needed to avert a more immediate health risk, Dr. Pandharipande noted.
"Patients with Testicular Cancer Undergoing CT Surveillance Demonstrate a Pitfall of Radiation-induced Cancer Risk Estimates: The Timing Paradox." Collaborating with Dr. Pandharipande were Jonathan D. Eisenberg, B.A., Richard J. Lee, M.D., Ph.D., Michael E. Gilmore, M.B.A., Ekin A. Turan, B.S., Sarabjeet Singh, M.D., Mannudeep K. Kalra, M.D., Bob Liu, Ph.D., Chung Yin Kong, Ph.D., and G. Scott Gazelle, M.D., M.P.H.
Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc.
RSNA is an association of more than 50,000 radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation.
The Society is based in Oak Brook, Ill.
For patient-friendly information on CT, visit RadiologyInfo.org.
Linda Brooks | EurekAlert!
Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University
The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy