Bremsstrahlung dose of therapeutic beta nuclides in bone and muscle

Bremsstrahlung dose of 165Dy in radiosynovectomy

There has been an increased interest in ¹⁶⁵Dy radiossynovectomy, which emits relatively high‐energy (> 1 MeV) beta rays. The production of in vivo bremsstrachlung radiation hazards warrants evaluation. The bremsstrahlung component of the decay scheme of ¹⁶⁵Dy has been traditionally ignored in internal dosimetry calculations. We have estimated the bremsstrahlung dose of ¹⁶⁵Dy distributed in muscle and bone to body by various internal organs (adrenals, brain, breasts, gallbladder wall, LLI wall, small intestine, stomach, ULI wall, heart wall, kidneys, liver, lungs, muscle, ovaries, pancreas, red marrow, bone surfaces, skin, spleen, testes, thymus, thyroid, urine bladder wall, uterus, fetus, placenta, and total body) during radiosynovictomy. In the present study, muscle and bone are considered to be source organs. These estimated values show that the bremsstrahlung radiation absorbed dose contribution from an organ to itself is very small compared to that originating from the beta source. However, contribution to other organs is not always negligible, especially when large amounts of ¹⁶⁵Dy may be involved, such as in therapy applications. Hence the component of the total dose due to bremsstrahlung dose should be considered in radiosynovictomy or other therapy applications.

PACS numbers: 34.80.‐i, 78.70.‐g, 33.20.Rm, 34.50.Bw