Towardsin vivomonitoring of neutron distributions for quality control of BNCT

Abstract

Dose delivery in boron neutron capture therapy (BNCT) is complex because several components contribute to the dose absorbed in tissue. This dose is largely determined by local boron concentration, thermal neutron distribution and patient positioning. In vivo measurements of these factors would considerably improve quality control and safety. During therapy, a y-ray telescope measures the y-rays emitted following neutron capture by hydrogen and boron in a small volume of the head of a patient. Scans of hydrogen y-ray emissions could be used to verify the actual distribution of thermal neutrons during neutron irradiation. The method was first tested on different phantoms. These measurements showed good agreement with calculations based on thermal neutron distributions derived from a treatment planning program and from Monte Carlo N-particle (MCNP) simulations. Next, the feasibility of telescope scans during patient irradiation therapy was demonstrated. Measurements were reproducible between irradiation fractions. In theory, this method can be used to verify the positioning of the patient in vivo and the delivery of thermal neutrons in tissue. However, differences between measurements and calculations based on a routine treatment planning program were observed. These differences could be used to refine the treatment planning. Further developments will be necessary for this method to become a standard quality control system.

30 Inorganic pharmaceuticals

“…233 Imaging the distribution of the boron-containing vehicle has been addressed by F-18 labelling for PET, 234 or by imaging gamma rays emitted during neutron irradiation. 235 Although borocaptate has specificity for glioblastoma cells, 236 a number of boron-containing conjugates (mostly incorporating carboranyl or related clusters) have been synthesised to support novel targeting strategies. They include porphyrin and metalloporphyrin derivatives, 205,230,237 antisense oligonucleotides, 238 nucleosides, 239 glycosides, 240 amino acids, 241242 polyamines, 243 somatostatin analogues, 244 and ligands for benzodiazepine receptor.…”

Boron‐Based Hybrid Nanostructures: Novel Applications of Modern Materials

“…A Monte Carlo-based treatment planning system (INEEL), taking into account the complex brain geometries, has been developed for BNCT studies. [25][26][27][28][29] More recently, the successor of the INEEL program, SERA (Simulation Environment for Radiotherapy Applications) has been introduced. This program consists of a succession of interactively cross-launched software modules or command lines designed for the iterative development of BNCT and GdNCT patient treatment plans.…”