CT scans are a vital diagnostic tool, enabling doctors to detect a wide range of conditions from tumors to kidney stones. However, a recent study published in JAMA Internal Medicine suggests that the ionizing radiation emitted during these scans may be contributing to the U.S. cancer burden. The study estimates that roughly 5% of all cancers diagnosed in the U.S. in a single year could be linked to CT scans. This article will delve into the findings of the study, explore the potential risks associated with CT scans, and provide guidance on how to minimize your exposure.
With the use of CT scans having surged by 35% since 2007, understanding the balance between the benefits and risks is crucial. We’ll examine the perspectives of experts, including radiologist Dr. Rebecca Smith-Bindman from the University of California, San Francisco, and Dr. Dana Smetherman, CEO of the American College of Radiologists. By the end of this article, you’ll be equipped with the knowledge to make informed decisions about your healthcare and discuss potential concerns with your doctor.
Understanding CT Scans and Radiation Exposure
Computed Tomography (CT) scans use X-rays to create detailed cross-sectional images of the body. While traditional X-rays provide a single view, CT scans offer a series of images that can be compiled to create a 3D representation. This allows doctors to visualize internal organs, bones, and tissues with greater clarity.
The primary concern with CT scans is the use of ionizing radiation. Ionizing radiation has enough energy to remove electrons from atoms, which can damage DNA and potentially lead to cancer. The amount of radiation emitted during a CT scan varies depending on the body part being scanned and the specific machine used. However, even a single CT scan exposes a patient to significantly more radiation than a standard X-ray.
According to Dr. Smith-Bindman, “Medical imaging has potential benefits, it has potential harms as well, and it’s really important to balance them.” This highlights the need for both healthcare providers and patients to carefully consider the necessity of each CT scan.
The Link Between CT Scans and Cancer Risk
The study in JAMA Internal Medicine projected that approximately 103,000 cancer diagnoses, or 5% of all cancers, could result from the 93 million CT scans performed in the U.S. in 2023 alone. This projection is based on statistical modeling and data from hospitals across 20 U.S. states. While there are no published studies directly linking CT scans to cancer, the statistical correlation raises concerns.
It’s important to note that the risk of developing cancer from a CT scan is relatively small. However, the risk increases with the number of scans a person receives over their lifetime. Children are also more vulnerable to the effects of radiation because their cells are dividing more rapidly.
Dr. Dana Smetherman from the American College of Radiologists emphasizes the importance of informed discussions: “As radiologists, we always want patients to be informed and feel comfortable asking the questions, ‘tell me more about this test, what’s involved, what’s it going to show you?’”
The Problem of Low-Value, Potentially Unnecessary Imaging
One of the key findings of the study is the growth in “low-value, potentially unnecessary imaging.” This refers to CT scans that may not provide significant diagnostic value or could be replaced by alternative imaging techniques that do not involve radiation, such as ultrasounds or MRIs. Factors contributing to unnecessary imaging include defensive medicine, patient demand, and a lack of awareness among healthcare providers about radiation risks.
Dr. Smith-Bindman points out that the amount of radiation a scan emits can vary widely depending on the operator and the facility: “The dose at one scanning facility can be eightfold higher than at another.” This suggests that optimizing the dose used in each scan is crucial to reducing risk.
Efforts to reduce unnecessary CT scans, such as the American Board of Internal Medicine Foundation’s Choosing Wisely initiative, have had limited success. This underscores the need for more effective strategies to promote responsible imaging practices.
How to Reduce Radiation Exposure from CT Scans
While you cannot undo past radiation exposure, there are several steps you can take to minimize future risk:
- Discuss the necessity of the scan with your doctor: Ask about the reasons for the scan and whether alternative imaging techniques are available.
- Inquire about the radiation dose: Ask your doctor or the radiologist how much radiation the scan will emit and whether they can use a low-dose technique.
- Keep a record of your scans: Maintain a list of all the CT scans you have received, including the date and the body part scanned. This information can help your doctor assess your cumulative radiation exposure.
- Consider getting a second opinion: If you are unsure about the need for a CT scan, seek a second opinion from another healthcare provider.
The University of California, San Francisco, hosts a website called Image Wisely. The website shows, a brain scan, can emit as little radiation as 200 dental X-rays or as much as 1,600. The radiation dose from an abdominal scan for a suspected kidney stone can be as low as 100 dental X-rays or as high as 8,000. Kidney stones also sometimes can be diagnosed with ultrasound, which does not emit radiation, the website notes.
Optimizing CT Scan Doses and Improving Practices
One of the most effective ways to reduce radiation exposure is to optimize the dose used in each CT scan. This involves adjusting the machine settings to use the lowest possible radiation dose that still provides a clear and accurate image. According to Dr. Smith-Bindman, “We can absolutely try to reduce all those excessive doses. We need buy-in from physicians and hospitals.”
Efforts are underway to establish quality measures for CT scanning and to promote the use of low-dose techniques. Under a mandate released in January, hospitals and imaging facilities share information about how much radiation their scanners emit. Based upon the information, Smith-Bindman and her colleagues are developing a quality measure for CT scanning.
Patients also have a role to play in promoting safer CT scanning practices. By asking their doctors to use low-dose techniques, they can help drive demand for more responsible imaging.
Exploring Alternative Imaging Techniques
In some cases, alternative imaging techniques that do not involve radiation may be appropriate. Ultrasounds and MRIs (magnetic resonance imaging) are two common alternatives. Ultrasounds use sound waves to create images, while MRIs use magnetic fields and radio waves. Neither technique involves ionizing radiation.
Ultrasounds are often used to image soft tissues and organs, such as the liver, kidneys, and gallbladder. They are also commonly used during pregnancy to monitor fetal development. MRIs are particularly useful for imaging the brain, spinal cord, and joints.
However, it is important to note that ultrasounds and MRIs are not always suitable replacements for CT scans. CT scans are generally faster and more widely available. They are also better at imaging bones and detecting certain types of abnormalities.
Making Informed Decisions About CT Scans
CT scans are a valuable diagnostic tool that can help doctors detect and diagnose a wide range of medical conditions. However, it is important to be aware of the potential risks associated with ionizing radiation. By understanding the benefits and risks of CT scans, discussing your concerns with your doctor, and taking steps to minimize your exposure, you can make informed decisions about your healthcare.
The key takeaways from this article are:
- CT scans use ionizing radiation, which can increase cancer risk.
- The risk is relatively small but increases with the number of scans.
- Unnecessary imaging is a growing problem.
- You can reduce your radiation exposure by discussing the need for the scan with your doctor and asking about low-dose techniques.
Ultimately, the decision of whether or not to undergo a CT scan should be made in consultation with your doctor. Together, you can weigh the potential benefits and risks and determine the best course of action for your individual situation.
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