For decades, shielding patients with lead aprons during X-rays and diagnostic imaging exams was considered a cornerstone of radiation safety. Today, however, radiation safety experts are calling for a shift in both practice and perception—one grounded in modern evidence rather than historical convention.
One of the leading voices in this shift is Brad Lofton, CEO of Colorado Associates in Medical Physics (CAMP) and chair of the American Association of Physicists in Medicine’s (AAPM) CARES Committee (Communicating Advances in Radiation Education for Shielding). Formed in 2019, CARES was established to align clinical practice with current scientific understanding of radiation exposure and to address persistent misunderstandings surrounding patient shielding.
In this interview, Lofton discusses the origins of CARES, the science driving its recommendations, and why reframing radiation protection matters for both clinicians and patients.
Why the CARES Committee Was Formed
The CARES Committee emerged in response to long-standing clinical habits that no longer reflected contemporary imaging technology or evidence. The effort was spearheaded by Rebecca Milman, PhD, a medical physicist at the University of Colorado, whose leadership and early advocacy were central to CARES’ formation. Her work focused on clarifying modern shielding guidance and improving how changes in best practice are communicated to clinicians, educators, and regulators. Lofton and others later joined in supporting and helping extend that work through broader professional engagement.
“A lot of these initiatives that were originally designed for radiation protection were actually alarming people unnecessarily,” Lofton said. “That was a key motivator behind CARES.”
Early CARES efforts focused on reevaluating the routine use of gonadal and abdominal shielding during radiographic exams. Decades ago, shielding made sense in an era of higher radiation doses and less sophisticated imaging systems. Today, however, most radiation scatter originates inside the body, meaning external lead aprons often provide little or no protective benefit. In some cases, shielding can actively undermine safety.
“When a shield is placed improperly, especially in CT or fluoroscopy, it can trigger the machine to increase the dose in order to maintain image quality,” Lofton explained. “You’re actually increasing exposure to the patient and to the staff in the room.”
From Evidence to Practice: CARES’ Early Work
Since its formation, CARES has focused on translating evidence into practical, defensible guidance. The committee clarified modern shielding recommendations by aligning with NCRP and ACR statements explaining why routine patient gonadal and fetal shielding is no longer recommended.
CARES also developed public- and professional-facing educational resources, including FAQs, sample dialogues, infographics, and slide decks designed to help clinicians, staff, and patients understand these changes clearly and consistently.
In addition, CARES has supported national practice change by partnering with and aligning alongside professional societies, educators, and regulators to harmonize policy language and training. This approach allows facilities to safely discontinue outdated shielding practices while maintaining regulatory compliance.
A Clarifying Moment in the Field
As CARES educators conducted site visits and educational sessions in community hospitals and imaging departments, they began to observe a subtle but important pattern among front-line technologists. Some were beginning to assume that occupational shielding was less important if patients were no longer being routinely shielded.
While this was not an explicit or universal belief, it highlighted how easily changes in one area of practice could be misinterpreted without clear explanation.
“Something that may be obvious to many of us in this field who’ve been working for a long time was not necessarily evident to practitioners in the clinical space,” Lofton recalled.
This realization reinforced the need for CARES’ central framework: clearly distinguishing intentional, incidental, and occupational radiation exposures—and explaining why different individuals in the same room require different protective approaches.
Protected By and From Radiation
Before addressing who should wear shielding and when, Lofton emphasizes the need for a broader, more balanced view of radiation protection—one that accounts for both protection from radiation and protection by radiation.
This concept was articulated by Duke University Professor Ehsan Samei during an AAPM/AIP virtual webinar series on enhancing radiation risk communication. Radiation protects patients by revealing disease and injury early, often preventing invasive or exploratory procedures. It guides interventions in cardiac catheterization labs and interventional radiology suites. In radiation oncology, it destroys tumor tissue and extends patient health, well-being, and life.
“We are protected both by radiation and from radiation,” Lofton said. “Our goal should always be best clinical care with the lowest appropriate radiation dose.”
“Protocol optimization is really our biggest tool when it comes to effective risk management in radiology,” he added.
The Science Behind the Shift
A growing body of evidence supports moving away from routine patient shielding in modern diagnostic imaging. Advances in CT, digital radiography, and fluoroscopy have led to substantial radiation dose reductions over time—often on the order of 20–40%, and in many cases far greater—compared with imaging systems in use several decades ago.
At the same time, shielding materials can obstruct anatomy or interfere with image quality, increasing the likelihood of repeat imaging or system compensation in some cases.
More concerning is the interaction between shielding and automated exposure control (AEC) systems. When shielding enters the imaging field, the system may interpret the obstruction as underexposure and compensate by increasing radiation output. In fluoroscopy, this compensation can elevate both patient skin dose and operator exposure.
“Our equipment has become more dose-efficient,” Lofton said. “But if shielding disrupts the scan, the machine compensates by increasing output. That’s not a safety measure—that’s an additional, unnecessary risk. Moreover, if the shielding is blocking a critical feature in the image, the exam has to be repeated.”
Why Low-Dose Radiation Risk Is So Hard to Communicate
At high doses, radiation effects are well understood, and thresholds exist for deterministic outcomes such as skin injury or cataract formation. At the very low doses used in diagnostic imaging, however, the relationship between exposure and harm becomes far more difficult to quantify.
“Radiation effects are well established at high doses, but at very low doses such as those used in diagnostic imaging, it’s very difficult to clearly prove added risk above background cancer rates,” Lofton explained.
In the United States, approximately 40% of men and 38% of women will develop cancer over their lifetime due to natural and lifestyle-related factors. Any potential incremental risk from diagnostic imaging is embedded within that background incidence and cannot be confidently isolated using current epidemiologic methods.
Risk models themselves rely on limited and sometimes conflicting data. The linear no-threshold (LNT) model, which underpins many radiation protection regulations, assumes proportional risk with dose. This model is intentionally conservative and useful for guiding policy and operational practice, but it does not imply that measurable harm occurs at diagnostic dose levels. Biological repair mechanisms are well established, and uncertainty remains regarding how low-dose exposures translate to population-level risk.
“The LNT model is conservative intentionally,” Lofton said. “It assumes small risk for any radiation exposure, which is useful for guiding policy and practice, but not necessarily pertinent to epidemiological or patient-specific dose management.”
Because of these uncertainties, radiation protection standards continue to follow the ALARA principle—as low as reasonably achievable—even though measurable risk at diagnostic levels is extremely small and difficult to quantify.
Risk Versus Benefit: The ACR Perspective
This balance underpins the American College of Radiology’s Appropriateness Criteria, which emphasize that radiation exposure to the patient should not be used as the deciding factor when selecting a diagnostic examination.
“That’s going to be a common theme,” Lofton emphasized. “The benefit of the imaging in the first place outweighs the risk to the patient.”
Exposure Categories and Practical Implementation
CARES frames radiation protection through three distinct exposure categories:
Intentional Exposure refers to the patient undergoing imaging to diagnose or rule out a medical condition. The patient receives the full clinical benefit of the exam, and exposure is justified. Dose reduction is achieved through exam appropriateness, protocol optimization, and avoiding unnecessary repeats—not routine shielding.
Incidental Exposure applies to caregivers or helpers who may be in the room but receive no diagnostic benefit. Their exposure is minimal and typically limited to scattered radiation. In these cases, shielding may still be offered or required by state or institutional regulations.
Occupational Exposure involves radiation workers who are routinely present during imaging or interventional procedures. These individuals are monitored, trained, and generally required to use protective equipment in accordance with regulatory thresholds.
“It’s about context,” Lofton emphasized. “If a parent is in the room once to hold their child during an X-ray, that’s very different from a cardiologist performing fluoroscopic procedures all day.”
In Colorado, for example, regulations still require non-patients in the room—such as parents or caregivers—to wear lead. CARES does not advocate against these regulations but seeks to reframe the conversation using evidence-based risk assessment and clearer communication.
Patient Education and Public Perception
One unintended consequence of outdated shielding practices is confusion and mistrust. When parents are asked to wear a lead apron while their children are not, the rationale can feel inconsistent.
“We hear parents say, ‘Why am I being shielded if my child isn’t?’” Lofton said. “That’s a perception issue—and perception matters in public health communication.”
By creating accessible, consistent educational materials, CARES aims to explain why shielding practices differ by exposure category. The committee continues to coordinate with organizations such as the National Council on Radiation Protection and Measurements (NCRP) and the American College of Radiology (ACR), which are developing more comprehensive, data-driven policy updates anticipated in late 2025.
Why It Matters
At the heart of this shift is the recognition that radiation protection must reflect modern evidence, not legacy habits. Improper shielding can do more harm than good, and well-intended practices may compromise diagnostic quality or unintentionally increase radiation dose.
“We don’t want to compromise the quality of the exam by introducing lead into it,” Lofton said. “And we certainly don’t want to increase the dose.”
For patients with questions, Lofton’s advice is straightforward: focus on the purpose of the exam and trust the clinical team to weigh risks and benefits appropriately.
“Your child is receiving the full benefit of this scan. You’re in the room. Your exposure is incidental and very low comparatively. However, you are not receiving any direct benefit from the exam; your child is,” he said. “That’s the reality.”
Conclusion
The CARES Committee’s work is not about removing protections. It is about ensuring that protections are effective, scientifically valid, and aligned with contemporary imaging practice. The shift away from routine patient shielding reflects a broader commitment to evidence-based care, patient safety, and transparent communication.
As radiation safety guidance continues to evolve, CARES is helping ensure that policy, education, and clinical practice evolve with it.
“We have to reframe the conversation around exposure categories,” Lofton concluded. “We need to reframe radiation protection in terms of risk versus benefit.”
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