First, the physics. Lutetium (pronouced loo-tee-shee-uhm) is element 71 in the periodic table. Below are the energy level and decay data. The primary mechanism of decay is emitting a beta-particle (an electron), transmuting into a stable isotope of hafnium. The maximum energy of this electron is about 500 keV. Two other possibilities (each happening in about one out of every ten decays) is beta decay of 177Lu to one of two excited levels of 177Hf followed by gamma decay. The two most common gamma photons have energies of 113 and 208 keV. Lutetium-177 produces few internal conversion or Auger electrons. The average energy of all the emitted electrons is about 150 keV, which have a range of about 0.25 mm. The half-life of 177Lu is roughly a week.
Next, the biology and medicine. Lutetium can be used for imaging (using the gamma rays) or therapy (using the electrons). While the dose arising from all the electrons does not make this isotope ideal for pure imaging studies (technetium-99m might be a better choice), the gammas do provide a way to monitor 177Lu during therapy (in this way it is similar to iodine-131 used in thyroid cancer therapy and imaging). Such a combined function allows the physician to do “theranostics” (a combination of therapy and diagnostics), a term I don’t care for but it is what it is. 177Lu can be bound to other molecules to improve its ability to target a tumor. For instance, it is sometimes attached to a molecule that binds specifically to prostate specific membrane antigen. The PSMA molecule is over-expressed in a tumor, so this allows the 177Lu to target prostate tumor cells. One advantage of using 177Lu in this way—rather than, say, using radiotherapy with x-rays directed at the prostate—is that the 177Lu will seek out and irradiate any metastasizing cancer cells as well as the main tumor. Clinical trials show that it can prolong the life of those suffering from prostate cancer.
Last November, right after the Presidential election, I wrote a blog post about trusted information on public health. In that post, I featured the science communication efforts by Katelyn Jetelina (Your Local Epidemiologist) and Andrea Love (Immunologic). I didn’t realize at the time just how much I would come to rely on these two science advocates for trustworthy information, especially related to vaccines.
Today, I recommend several more science communicators. The first is Skeptical Science. That website focuses primarily on climate science. The current Republican administration has denied and mocked the very idea of climate change, describing it as a “hoax.” Skeptical Science has a simple mission: “debunk climate misinformation.” This is extraordinarily important, as climate change may be the most important issue of our time. Check out their website www.skepticalscience.com, and follow them on Facebook. I just signed up for their Cranky Uncle app on my phone. I learned about Skeptical Science from my Climate Reality mentor, John Forslin. For those more interested in doing rather than reading and listening, I recommend The Climate Reality Project (Al Gore’s group). Take their training. I did. Oh, and don’t forget Katharine Hayhoe’s website https://www.katharinehayhoe.com.
Want to know more about science funding, especially to the National Institutes of Health? Check out Unbreaking.
They’re documenting all the bad stuff happening to science these days.
I learned about Unbreaking from Liz Neeley's weekly newsletter Meeting the Moment. Liz is married to Ed Yong, who I have written about before.
My next recommendation is Angela Rasmussen, a virologist who publishes at the site Rasmussen Retorts on Substack. What I like about Rasmussen is that she tells it like it is, and doesn’t worry if her salty language offends anyone. I must confess, as I experience more and more of what I call the Republican War on Science, I get angrier and angrier. Rasmussen’s retorts reflect my rage. She writes “Oh, also, I swear sometimes. It’s not the most professional behavior but I believe in calling things what they are and sometimes nothing besides ‘asshole’ is accurate.” Give ’em hell, Angie! Here’s the concluding two paragraphs of her August 5 post:
There’s always a ton of talk about how public health and science have lost trust. A lot of people like to tell me that it’s our fault. Scientists didn’t show enough humility or acknowledge uncertainty during the COVID pandemic. We were wrong about masks or vaccines or variants or whatever. We didn’t communicate clearly. We overclaimed and underdelivered. I reject these arguments.
The public didn’t lose trust in science because experts are wrong sometimes, and are imperfect human beings who make mistakes. They lost trust because people like [Robert F. Kennedy, Jr.] constantly lied about science. He is constantly lying still. He’s eliminating experts so that he and his functionaries on ACIP [The CDC’s Advisory Committee on Immunization Practices] will be able to continue lying without any inconvenient pushback. We need to recognize this and push back hard.
What am I doing to push back hard? Regular readers of this blog may recall my post from this April in which I imagined what Bob Park’s newsletter What’s New would look like today. Well, I’ve made that a weekly thing. You can find them published on my Medium account (https://medium.com/@bradroth). I’ll link a few of the updates below.
You will also find these IPMB blog posts republished there, plus a few other rants. When I started writing my updated version of What’s New, I (ha, ha)… I thought (ha, ha, ha!)... I thought that I might run out of things to talk about. That hasn’t been a problem. But writing a weekly newsletter in addition to my weekly IPMB blog posts takes time, and it makes me appreciate all the more the heroic efforts of Katelyn, Andrea, Liz, and Angela. I hope they all know how much we appreciate their effort.
Is there anything else on the horizon? The book Science Under Siege, by Michael Mann and Peter Hotez, is out next month. As soon as I can get my hands on a copy and read it, I will post a review on this blog. In the meantime, I’ll keep my powder dry, waiting until RFK Jr starts in on microwave health effects (Y’all know it’s coming). Now that’s physics applied to medicine and biology, right up my alley!
“Don’t Choose Extinction.” This is one of John Forslin’s favorite videos. Enjoy!
In dealing with radiation to the population at large, or to populations of radiation workers, the policy of the various regulatory agencies has been to adopt the linear no-threshold (LNT) model to extrapolate from what is known about the excess risk of cancer at moderately high doses and high dose rates, to low doses, including those below natural background.
Wow! This is not a dry, technical discussion. It is IPMB meets 60 Minutes. This is a hard-hitting investigation into scientific error and even scientific fraud. It’s amazing, fascinating, and staggering.
John Cardarelli, the president of the Health Physics Society when the videos were filmed, acts as the host, introducing and concluding each of the 22 episodes. The heart of the video series is Barbara Hamrick, past president of the Health Physics Society, interviewing Edward Calabrese, a leading toxicologist and a champion of the hormesis model (low doses of radiation are beneficial).
Calabrese claims that our use of the linear no-threshold model is based on “severe scientific, ethical, and policy problems.” He reviews the history of the LNT model, starting with the work of the Nobel Prize winner Hermann Muller on the genetics of fruit flies. He reviews the evidence to support his contention that Muller and other scientists were biased in favor of the LNT model, and sometimes carried that bias to extreme lengths. At first I said to myself “this is interesting, but its all ancient history.” But as the video series progressed, it approached closer and closer to the present, and I began to appreciate how these early studies impact our current safety and regulatory standards.
I watched every minute of this gripping tale. (OK, I admit I watched it at a 2x playback speed, and I skipped Cardarelli’s introductions and conclusions after the first couple videos; there is only so much time in a day.) Anyone interested in the linear no-threshold model needs to watch this. I have to confess, I can offer no independent confirmation of Calabrese’s claims. I’m not a toxicologist, and my closest approach to radiobiology is being a coauthor on IPMB. Still, if Calabrese’s claims are even half true then the LNT assumption is based on weak data, to put it mildly.
Watch these videos. Maybe you’ll agree with them and maybe not, but I bet you’ll enjoy them. You may be surprised and even astounded by them.
I am an emeritus professor of physics at Oakland University, and coauthor of the textbook Intermediate Physics for Medicine and Biology. The purpose of this blog is specifically to support and promote my textbook, and in general to illustrate applications of physics to medicine and biology.
