Radium-223 dichloride (radium-223) is a radioactive isotope that emits low levels of alpha particle radiation, which causes double-strand breaks in DNA in close proximity, killing cancer cells. It mimics calcium and accumulates in areas of bone that are undergoing increased calcium buildup, due to bone metastases (an update from a 2022 review, by Chris Woollams).
Radium - 233 action and benefit
Increasingly, men with advance stage prostate cancer that has spread to the bones are offered this 'advanced' treatment.
Radium contains many similarities to calcium. It is in the same column of the periodic table. When prostate cancer has gone to the bones, high levels of calcium are observed in these cancer cells. Radium 233 is drawn to these areas.
Radium 233, or Xofigo® is a radioactive isotope emitting only low levels of alpha particle radiation. It only travels short distances. Thus the bone cancer cells take up the Radium and it kills them, but there is little or no damage to surrounding healthy cells. The isotope also has a half life of just 11.4 days.
In the ALSYMPcA trial in the Royal Marsden and the Institute of Cancer Research in Sutton UK (1) men who received radium-223 lived longer without having a skeletal-related event than men on the placebo (15.6 months versus 9.8 months).
Radium - 233 protocol
You will have a bone scan about a week before the treatment and you should not consume calcium (in supplements or any dairy) before the treatment.
The programme involves an injection; 6 rounds every 4 weeks. You can expect to have radiation in your urine and stools. But this is low, and decreases rapidly.
Side-effects of Radium 233
These are said to be usually mild - diarrhoea, sickness and temporary bone marrow suppression being most common. Although the half-life of the Radium 233 is said to be less than 12 days, apparently men should not attempt to father a baby within 6 months of treatment!
Damage to Microbiome - However, few commentators on side-effects look into damage to the gut microbiome. In a pilot study in 2022, Portuguese researchers found that Ra-223 influenced the gut microbiota composition with increases of Proteobacteria and Atopobacter; and decreases of Bacteroidetes, Prevotella, Lactobacillus, Bifidobacterium, Clostridium coccoides, and Bacteroides fragilis. The results of this pilot study suggested that the gut microbiota of prostate cancer patients after Radium 233 showed an increase in harmful bacteria and a decrease in friendly bacteria (2).
Less side effects than patients without Radium 233 - The ALSYMPcA trial (1) also showed that fewer men in the radium-223 group experienced serious adverse events (47 percent versus 60 percent) or stopped treatment because of adverse events (16 percent versus 21 percent) than in the placebo group.
Go to: Lutetium 177 kills prostate cancer cells
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Reference
- Alpha Emitter Radium-223 and Survival in Metastatic Prostate Cancer; C. Parker, S. Nilsson, D. Heinrich, S.I. Helle, J.M. O'Sullivan, S.D. Fosså, A. Chodacki, P. Wiechno, J. Logue, M. Seke, A. Widmark, D.C. Johannessen, et al. The New England Journal of Medicine; July 18 2013
- Effect of Radium-223 on the Gut Microbiota of Prostate Cancer Patients: A Pilot Case Series Study; Ana Fernandez et al, 11 October 2022, MDPI
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