Analysis of Effect on Microdose of ¹⁰B Nonuniform Distribution in Cellular

Boron neutron capture therapy (BNCT) is one of the effective way to treat malignant melanoma and head-neck cancer. The intercellular nonuniform distributions of ¹⁰B in tumor cell impact the estimates of inactivation dose. The α-Li Version 1.0 code was developed based on Monte-Carlo method to calculate the S values of cell induced by αand ⁷Li particle which are the products of ¹⁰B（n,α）⁷Li. The calculation included two types of cell size, eight kinds of energy of α particle and three kinds of source distributions. Differences between results of this code and an analytical algorithm of MIRD committee were within 1%. On this basis, a total of 3 420 cases were calculated and analyzed with different kinds of nucleus radius, cell radius, and source launch position combination. Finally, cellular S values of ¹⁰B（n,α）⁷Li calculated in this paper can be used to compute the excellent precision dose under ¹⁰B compound nonuniform distribution in intercellular scale.