A stochastic model for subcellular dosimetry in boron neutron capture therapy

Area of Science:

• Medical Physics
• Radiochemistry
• Oncology

Background:

• Therapeutic effectiveness of Boron Neutron Capture Therapy (BNCT) is critically dependent on the microscopic distribution of boron compounds within tumor cells.
• Variations in boron compound uptake mechanisms can lead to differing therapeutic outcomes, even with similar macroscopic concentrations.

Purpose of the Study:

• To develop and apply a stochastic model for subcellular dosimetry in BNCT.
• To calculate the probability of energy deposition in the cell nucleus and cell survival probability.
• To determine Relative Local Efficiency (RLE) factors for different boron compounds.

Main Methods:

• Development of a stochastic model for subcellular dosimetry.
• Measurement of subcellular boron distributions in RG 2 rat gliomas using subcellular fractionation.
• Administration of two boron compounds: sulphydryl boron hydride (BSH) and boronated porphyrin (BOPP).
• Calculation of RLE factors based on measured distributions and the stochastic model.

Main Results:

• The stochastic model enables calculation of energy deposition probability per neutron capture.
• The model can estimate cell survival probability under specific dose conditions.
• RLE factors were calculated for BSH and BOPP based on experimental subcellular distribution data.

Conclusions:

• Subcellular boron distribution significantly impacts BNCT efficacy.
• The developed stochastic dosimetry model provides a quantitative method to assess the impact of boron distribution on therapeutic outcomes.
• This approach allows for the comparison of different boron delivery agents, such as BSH and BOPP, to optimize BNCT treatment planning.