[Intl_DxMedPhys] Heads up on NEJM paper on radiation exposure in peds and hematologic cancer risk

Wed Sep 24 13:03:22 EDT 2025

>From a clinical physicist standpoint, let’s try a thought experiment. Suppose that regardless of the quality of the science or our criticisms of it, the essential conclusions of this paper will end up driving or guiding our field. I do think that will end up happening to some extent, given the “first-mover” effect of this research having been published with high visibility in one of the top journals not just in radiology but all of medicine. Any responses from professional organizations will be reactive and much less visible than the paper itself.

Given that background, what can we, and should we, do about it as medical physicists proactively, *before* that decision is made for us and we are forced to react? I believe we will make better decisions proactively than what would be forced upon us by knee-jerk action of less-expert authorities, and you can bet that hospital presidents and physician leaders (I’m talking CMOs, not Radiology chairs) are going to want to “get in front of this."

This paper isn’t going to spell the end of CT by any means. Even if you accept the risks described in this paper as accurate, the medical benefits when a scan is medically appropriate are several orders of magnitude larger.

However, if we don’t want to get dragged down by a barrage of questions and challenges about radiation dose, we could approach this by assuming the paper is right, deciding what we would do if that were the case, and taking proactive steps to address those concerns and make improvements. Then instead of reacting and being jerked around by the inevitable questions, we’re in a position to say “thanks, we’re aware of it, already working on it, and here’s what we’ve done/are doing.” This lets us stay in the driver’s seat to maintain image quality and diagnostic utility instead of getting swept along in the obsession with reducing and avoiding radiation dose.

---
On Sep 24, 2025 at 10:40 AM -0400, Gao, Yiming via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>, wrote:
> Hi Kai, I think there are many unanswered questions for this published paper. Here are my thoughts: Apparently they used the UF/NCI phantom library to match patients to phantoms and compute organ and effective doses. They mentioned “missing
> Hi Kai,
>
> I think there are many unanswered questions for this published paper. Here are my thoughts:
>
>
> 1. Apparently they used the UF/NCI phantom library to match patients to phantoms and compute organ and effective doses. They mentioned “missing height or weight” in both US and Canadian exams, and the matching process is yet based on height and weight. They filled in the missing data with median values, but the questions are: (1) how much percentage of the dataset is missing height and weight, (2) have they tried different filling methods and compared the outcome, (3) can they use effective diameter instead of height & weight for matching and how different the outcome would be?
> 2. They mentioned exams missing CT acquisition parameters and just filled them randomly by using a multilevel random effects model, so again (1) how much percentage is missing the parameters, (2) have they tried different models and (3) can they use a different filling method.
> 3. They mentioned “One U.S. site was unable to abstract individual CT dose”. I’m assuming they are talking about CTDIvol here, so again (1) how much percentage is missing CTDIvol, (2) how did they fill in the missing data for CTDIvol. They also mentioned a “random forest model” which filled in missing technical parameters, so is it the same model as the “multilevel random effects model” in point 2?
>
>
> In terms patient demographics, CT acquisition parameters, and CTDIvol (“CT dose”), there are many unanswered questions and their models for filling the missing parameters are unclear and unverified. I wonder how this paper got through the reviewers and editors…
>
> Best wishes,
> Yiming Gao,
> Assistant Attending Physicist,
> MSKCC
>
> From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+gaoy1=mskcc.org at lists.osu.edu> On Behalf Of Yang, Kai, PhD via Intl_dxmedphys_wd_osu_list
> Sent: Wednesday, September 24, 2025 9:52 AM
> To: Mark Supanich <Mark_Supanich at rush.edu>; Jerry Thomas <jerry.thomas at ascension.org>
> Cc: intl_dxmedphys_wd_osu_list at lists.osu.edu
> Subject: Re: [Intl_DxMedPhys] [EXTERNAL] Re: Heads up on NEJM paper on radiation exposure in peds and hematologic cancer risk
>
> Hi everyone, as I am reading through the appendix 1 for that paper, it turned out that they didn't even have most of the real dose data, but other than "guessing it out"? Below is the exact text, would love to hear what others think.
> Hi everyone, as I am reading through the appendix 1 for that paper, it turned out that they didn't even have most of the real dose data, but other than "guessing it out"? Below is the exact text, would love to hear what others think.
> Hi everyone, as I am reading through the appendix 1 for that paper, it turned out that they didn't even have most of the real dose data, but other than "guessing it out"? Below is the exact text, would love to hear what others think.
>
> <image001.png>
>
> <image002.png>
> From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu> on behalf of Jerry Thomas via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
> Sent: Monday, September 22, 2025 12:11 PM
> To: Mark Supanich <Mark_Supanich at rush.edu>
> Cc: intl_dxmedphys_wd_osu_list at lists.osu.edu <intl_dxmedphys_wd_osu_list at lists.osu.edu>
> Subject: Re: [Intl_DxMedPhys] [EXTERNAL] Re: Heads up on NEJM paper on radiation exposure in peds and hematologic cancer risk
>
> Mark and Baojun, Great points. Both need to be in a letter to the editor. Unfortunately, the reviewers of this paper failed to do their job. -- They were either, biased in favor of the paper's conclusions, busy and did not read the paper
>         External Email - Use Caution
> Mark and Baojun,
>
>       Great points.  Both need to be in a letter to the editor.  Unfortunately, the reviewers of this paper failed to do their job.  -- They were either, biased in favor of the paper's conclusions, busy and did not read the paper critically, or were reviewing work that they were not qualified to review.  Regardless this paper will be quoted, so it is now imperative that a letter to the editor be written.  I would enjoy reading the response to the letter. --- especially the support for hormesis that Mark pointed out.
>
>
> Jerry Thomas, MS, FAAPM, DABR, CHP, DABSNM
> Diagnostic Medical Physicist / Radiation Safety Officer
> Ascension Via Christi Hospitals Wichita
> Wichita, KS  67214
>
> Phone:  316-268-5958  (office)
>             240-447-1014  (cell)
>
>
> On Fri, Sep 19, 2025 at 3:18 PM Mark Supanich via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu> wrote:
> > quote_type
> > An interesting note on this is that they also could have claimed that low levels of ionizing radiation have a positive impact on hematologic cancer rates. They cancer incidence rate (cases per 10,000 in their cohort) was lower for groups receiving
> > An interesting note on this is that they also could have claimed that low levels of ionizing radiation have a positive impact on hematologic cancer rates. They cancer incidence rate (cases per 10,000 in their cohort) was lower for groups receiving between 5-15 mGy dose to the bone marrow than the group with no medical imaging. Their own calculated ERR was even <1 for the 5-10 mGy group.
> >
> > I wonder why the headlines aren't: "exposure to low levels of ionizing radiation protects children from blood cancer"?
> >
> >
> > From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu> on behalf of Li, Baojun via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
> > Sent: Friday, September 19, 2025 1:01 PM
> > To: intl_dxmedphys_wd_osu_list at lists.osu.edu <intl_dxmedphys_wd_osu_list at lists.osu.edu>
> > Subject: Re: [Intl_DxMedPhys] Heads up on NEJM paper on radiation exposure in peds and hematologic cancer risk
> >
> > Rush Email Security
> > This email originated from outside of RUSH. Do not click links or attachments unless you recognize the sender and know that the content is safe. RUSH will never ask for user ID information via email.
> > If we replace “accumulative dose to bone marrow” with “total number of blood draws or hospital visits,” the relationship would likely still hold. By the authors’ reasoning, one could then conclude that blood draws or hospital visits cause cancer?!
> > If we replace “accumulative dose to bone marrow” with “total number of blood draws or hospital visits,” the relationship would likely still hold. By the authors’ reasoning, one could then conclude that blood draws or hospital visits cause cancer?!
> >
> > In reality, children who undergo multiple CT examinations typically do so because of more severe or complex medical conditions. These patients are inherently predisposed to more hospital encounters and already have a higher baseline risk of hematologic malignancies, independent of imaging. The causal inference presented by the authors is deeply flawed and misleading.
> >
> > Thanks,
> > Baojun
> >
> >
> > From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+baojunli=bu.edu at lists.osu.edu> On Behalf Of Mark Supanich via Intl_dxmedphys_wd_osu_list
> > Sent: Wednesday, September 17, 2025 6:35 PM
> > To: intl_dxmedphys_wd_osu_list at lists.osu.edu
> > Subject: [Intl_DxMedPhys] Heads up on NEJM paper on radiation exposure in peds and hematologic cancer risk
> >
> > Hi all, Just a heads up that NEJM published a paper from Smith-Bindman et al this afternoon. https: //www. nejm. org/doi/full/10. 1056/NEJMoa2502098?query=featured_home It’s an observational study of 3. 5+ million peds looking at cumulative
> > Hi all,
> >
> >
> > Just a heads up that NEJM published a paper from Smith-Bindman et al this afternoon. https://urldefense.com/v3/__https://www.nejm.org/doi/full/10.1056/NEJMoa2502098?query=featured_home__;!!KGKeukY!359jNpqFkZ0Q78XzGA0j5S_0mQbAN3tuPI4TVnJvzxiDfen4flgG0iWfAE5kB96vkmmbsQOx1kMHV5sFK1etpcSPdMH9GKMLgoJMuGr-RFs$ 
> >
> > It’s an observational study of 3.5+ million peds looking at cumulative exposure to ionizing radiation, particularly focused on bone marrow dose, and increased risk of hematologic cancer incidence. Their results claim an increased incidence of cancer in patients with exposure to imaging, and demonstrate a cummulative dose effect. They claim their results are not likely due to reverse causation as they have reasons for exams and symptoms of these cancers were not common reasons for exams. They also note their results are inline with the EPI-CT study. Of note, it appears that they looked at imaging from 1996-2017 – so much of the imaging likely occurred on imaging equipment without many of the modern dose reduction features.
> >
> > This is sure to get media play and parents will certainly have questions as the media coverage develops. Continuing to focus on the judicious use of imaging, the benefits of diagnostic imaging to answer clinical questions, and the fact that modern imaging equipment adapts to patient size and uses optimized radiation will be key talking points.
> >
> > From the paper: “By the end of follow-up, 7.5% (280,548 of 3,724,623) of all the children and 9.2% (272 of 2961) of those in whom a hematologic cancer developed had received a cumulative dose of at least 1 mGy.”
> >
> > <image003.png>
> >
> > There is a lot to look at in this paper and the supplemental materials, so more information/analysis is sure to come.
> > --
> > Mark P. Supanich, Ph.D., DABR, FAAPM (he/him)
> > Director – Diagnostic Medical Physics
> > Rush University System for Health
> > Associate Professor & Vice Chair for Physics and Informatics
> > Rush Medical College Department of Diagnostic Radiology and Nuclear Medicine
> > <image004.png>
> >
>
>
>
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