The production of positron emitters with millisecond half-life during helium beam radiotherapy.

This study presents the first measurements of the production of short-lived positron emitters in water, graphite, calcium and phosphorus targets irradiated with 59 MeV/u 3He and 50 MeV/u 4He beams. For these targets, the most produced short-lived nuclides are 13O/12N (T1/2 = 8.6/11 ms) on water, 13O/12N on graphite, 43Ti/41Sc/42Sc (T1/2 = 509 - 680 ms) on calcium, 28P (T1/2 = 268 ms) on phosphorus. A translation of the results from elemental targets to PMMA and representative tissues such as adipose tissue, muscle, compact and cortical bone, shows the dominance of 13O/12N in at least the first 20 s of an irradiation with 4He and somewhat longer with 3He. As the production of 13O/12N in a 3He irradiation is 3 to 4 times higher than in a 4He irradiation, from a statistical point of view, range verification using 13O/12N PET imaging will be about 2 times more precise for a 3He irradiation compared to a 4He irradiation. PMID: 31658450 [PubMed - as supplied by publisher]
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research