Targeted alpha therapy is an example of a technology that is used to kill cancer. It shows particular promise against dispersed cancers such as leukemia and lymphoma. A radioisotope that undergoes alpha decay is chemically bonded to an antibody and injected into the body. The antibody seeks out and binds to the desired cell, then after a certain time period, the attached radioisotope decays and the alpha particle emitted during the decay kills the targeted cell. Targeted alpha therapy has shown great promise but has been strongly limited by the supply of suitable radioisotopes. The most promising is bismuth-213, which has a half-life of 45 minutes and is formed from the decay of uranium-233.

Actinium-225 (225Ac) and bismuth-213 (213Bi) are uniquely formed from the decay of uranium-233 (233U), the nuclear fuel in a LFTR, which in turn is formed from neutron absorption on thorium. Thorium-229 (229Th) is the decay product of 233U and could be chemically removed from the LFTR as it forms. 229Th decays into actinium-225, which would then be shipped to hospitals on a regular basis and would provide a steady 213Bi supply for patients afflicted with cancer. This would spare these patients from the suffering and danger of chemotherapy as a treatment option.

I’ve been talking about targeted alpha therapy for many years. The first video recording I’ve found where I was discussing it was at my third Google “Tech-Talk” in January 2011. It was part of my overall thesis that we should save the US inventory of uranium-233 from irreversible downblending:

I explained how an inventory of 1000 kg of 233U will produce about four grams of 229Th from decay each year, despite the very long half-life of 233U. I also mentioned a congressional report from 2001 encouraging that 229Th be harvested from 233U prior to any downblending or disposition of the parent material.

Just a few months later, in May 2011, I was again talking about it at the Thorium Energy Alliance Conference 2011 in Washington, DC. I described its potential and mentioned the 2001 report again. This is also the conference where I announced the formation of our new company, Flibe Energy:

A year later at the next Thorium Energy Alliance Conference in Chicago I continued talking about fighting cancer with alpha particles. This time I went through the four decay chains and the many alpha-emitting radioisotopes that existed, and showed how only a small number had promise for alpha therapy. The two most promising candidates exist on the decay chain that is recreated in the thorium reactor. I also pointed out how this decay chain is unique in that it does not contain radon:

Six years later, I lamented the lack of progress on 233U preservation at the Thorium Energy Conference (ThEC2018) in Brussels. I encouraged the attendees to make this story more widely known, and to emphasize the connection between fighting cancer and developing thorium reactors:

In my 2011 talk I said that I sometimes lay in bed thinking that if my child had leukemia, how hard would I be working on getting this therapy ready for them, to save their life? And if it’s that important why aren’t I going full-bore on it right now?

Well, that time has come for me. Now someone I love dearly is suffering from cancer and needs the targeted alpha therapy option, and it just isn’t ready yet. I’ve been working and struggling and pushing for this for at least 16 years, and the moment has come, and we’re not ready. But I’m still fighting, and I really need some help.