Radiation dose safety: Filtering the message from the noise

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It's no secret patient radiation dose safety is on the forefront of the imaging industry. The countless media coverage, articles, and discussions on this matter have led the subject to dominate the industry media activities and regulatory interest. But as often happens when a subject is hot, the radiation safety information pool has become muddied with disparate and conflicting information.

With numerous opinions and interpretations on radiation safety trends, best practices, regulation updates, and studies, healthcare providers and the general public are experiencing difficulties filtering the true message in radiation safety away from industry noise. Healthcare providers are constantly reviewing and assessing regulations, best imaging processes, and the emerging technologies (automated dose management systems and CT dose management software), promising to decrease or eliminate the chances that healthcare providers will experience a sentinel event of radiation exposure.

Neil Singh of Ascendian Healthcare Consulting.Neil Singh of Ascendian Healthcare Consulting.
Neil Singh of Ascendian Healthcare Consulting.

With the development of new industry trends and regulatory updates, healthcare providers are continuously resetting their expectation and requirements for their internal radiation safety programs and technology. While it seems that the momentum behind radiation safety is a new push, in actuality, the issue has lingered since November 8, 1895 -- the day x-rays were discovered.

Recent industry trends demonstrate that many healthcare providers are rushing to implement an automated solution without developing a robust internal radiation safety program. The new case study published in the Journal of American College of Radiology confirms that findings based solely using CT dose index (CTDI) and dose-length product (DLP) values can be flawed (JACR, March 2014, Vol. 11:3, pp. 233-237). Healthcare providers leveraging their entire radiation safety program on some automated solution that only measures these points are in for a rude awakening.


A good radiation safety program is multifaceted. Regardless of the implementation of automated radiation dose management systems and software, a healthcare provider's radiation safety program must include well-established and continuous CT imaging protocol management for adult and pediatric patients, ongoing training/education plan for all staff members, incident risk management planning, advanced workflows, including order decision support, imaging policies and procedures, patient education and communication, and methods in messaging and marketing the program to the community, perhaps even the industry.

Patient radiation dose safety has again gained regulatory interest; the Joint Commission released its 2014 standards (requirements) for diagnostic imaging, JACR released the case study on the risk of using CTDI and DLP as aggregate patient dose management guidelines, and the sustainable growth rate (SGR) fix passed by the U.S. House of Representatives included radiation safety measures.

Joint Commission requirements

Numerous articles have reviewed the 2014 Joint Commission standards for diagnostic imaging; however, there is still confusion on the interpretation for some of the standards. Many articles confuse the reader by incorporating MRI standards with radiation safety guidelines. Here, we will simply focus on CT imaging. The facts are these:

  • By July 1, 2015, all individuals performing CT procedures must be registered with the American Registry of Radiologic Technologists (ARRT) or the Nuclear Medicine Technology Certification Board (NMTCB).
  • Healthcare providers must have a robust internal radiation safety program, which includes a strong ongoing education/training component guided by the Image Gently and Image Wisely campaigns.
  • Healthcare providers who provide CT imaging services must report patient's radiation dose (CTDI and DLP) information in the diagnostic imaging report, as well as make it part of the patient's medical record.
  • For the elements of performance, healthcare providers must have adult and pediatric CT imaging protocols benchmarked and reviewed annually by a physicist.

The Joint Commission did not state in the requirements that technologists must be registered in CT. The 2014 standard, however, requires providers to manage the CT device's CTDI and DLP radiation dose output. One must consider that CTDI and DLP dose values do not reflect the true effective dose or size-specific dose estimate (SSDE) for the patient. Healthcare providers seeking effective dose or SSDE dose values must incorporate the patient size and habitus and also other imaging technique variables calculated and validated by a medical physicist.

Dose is not always what it seems

Recently, the JACR conducted and released a case study on the accuracy of using CTDI and DLP dose values as an effective method for monitoring patient radiation dose. The study was conducted when a concerned parent of a patient requested the CT dose information from the pre- and postprocedure CT scans.

The dose information was given to the parent without altering the data (true effective or size-specific dose calculations were not calculated), or with proper "instructions" or education. The parent's concern triggered an advanced investigation into the incident and the two different dose outputs received from the procedures.

Because the two studies of the same patient and body part were performed on two different CT devices (different manufacturers using two different phantom sizes for dose output calculations), the two scans produced two very different CTDI and DLP values. The JACR study concludes the sole reference to CTDI and DLP dose values, without true calculation of SSDE or effective dose, are not effective or accurate methods in managing a patient's radiation dose.

The case study confirms the importance of establishing a robust radiation safety program, which is a combination of people, process, and technology. CTDI and DLP dose values are nowhere near close to the effective radiation dose received by the patient. The device and dose calibration to phantom size only serves a purpose to control the CT scanner's radiation dose output based on a specified phantom size (16 cm or 32 cm). The phantom size for patient dose management does not take into account key calculation factors such as weight, body habitus and composition, tube angle, etc., which would determine the true effective dose.

The movement for better radiation dose safety awareness has also brought forward automated radiation dose management technologies claiming to minimize or even eliminate radiation-related sentinel events or radiation overexposure. That may be true; however, these automated solutions do not assist healthcare providers with flawless tools in managing the patient's aggregate effective dose.

Accurately managing patient radiation dose is a combination of the right people (physicists, technologists, radiologists, risk management, etc.), the right processes (dose calculation, CT protocol management, risk management, informed decision support, patient and staff education, etc.), and the right technology (updated CT devices with low-dose technology, order entry management decision support, automated dose management solution, etc.). Healthcare providers must not solely depend on an automated solution to manage its entire radiation dose safety program.

The JACR case study confirmed what physicists knew and feared from the beginning, and has placed the imaging community back to the starting point in developing a robust internal radiation safety program.

Dose and the SGR fix

When the U.S. House of Representatives delayed the activation of the SGR formula's 24% cut to Medicare reimbursement with HR 4302, it did more than just delay the SGR by 13 months; it also included the following additional requirements for imaging healthcare providers on radiation safety:

  • Ordering physician decision support for advanced imaging procedure.
  • Improved and stricter patient radiation dose safety controls and levels.
  • CT equipment must meet the National Electrical Manufacturer Association (NEMA) standards.

Supported by the American College of Radiology (ACR), HR 4302 reinforces radiation safety standards for organizations dependent on Medicare reimbursement.

Radiation safety will continue to gain traction in the industry. Regulatory entities will continue to refine the standards until they strike a balance of people, process, and technology defining a radiation dose program. Healthcare providers must proactively forge ahead of the emerging trends and regulations in developing a codified, sustainable, and comprehensive radiation safety program.

Neil Singh is a senior consultant at Ascendian Healthcare Consulting and a frequent speaker and published contributor to the subject of enterprise dose management and tracking. You may contact him directly at nsingh@ascendian.com, or visit the Ascendian website for more information.


  1. American College of Radiology. House of Representatives passes 12-month SGR patch; numerous ACR supported imaging provisions included in legislation. ACR website. March 28, 2014. Available at http://www.acr.org/Advocacy/eNews/20140328-Issue/House-of-Representatives-Passes-12-Month-SGR-Patch.
  2. Joint Commission. Prepublication - diagnostic imaging services requirements. December 20, 2013. Available at http://www.jointcommission.org/prepublication_diagnostic_imaging_services_requirements.
  3. Siebert JA, Boone JM, Wootton-Gorges SL, Lamba R. Dose is not always what it seems: Where very misleading values can result from volume CT dose index and dose length product. J Am Coll Radiol. 2014;11(3):233-237. Available at http://www.jacr.org/article/S1546-1440(13)00663-7/fulltext.
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