Beta-Minus Emitters Dose Point Kernel Estimation Model Comprising Different Tissues for Nuclear Medicine Dosimetry Applications

I. SCARINCI; F. GESER; M. VALENTE; P. PÉREZ; F. MALANO

International Journal of Nuclear Medicine Research

Cosmos Scholars Publishing House

Lugar: Columbia; Año: 2016 vol. 3 p. 45 - 55

The use of β-emitters for therapy purposes is one of the most extended procedures for tumor treatments innuclear medicine practices over the last years. The constantly increasing dose delivery to healthy tissues in thispractices, due to their high linear energy transfer and their radiobiological characteristics, might lead to complications inradiosensitive organs/tissues. Research efforts should be conducted to the development of tools and methods devotedto perform precise dosimetric calculations to deal with this issue and assess accurately dosimetric estimations onpatients treated regions.When performing dosimetry at organ level it is usual to assume some approximations on calculations, like uniformity inactivity distribution within source regions, homogeneous media distribution for patient treated regions and uniformdelivered dose on target organs. In this work, a formula to obtain Dose Point Kernel for different biological media ispresented. Results are collated with Monte Carlo simulations suggesting a behavior that can be splitted in three groups,in accordance to their differences against the stochastic estimations: a) skin, blood and brain present differences withinthe 5% in comparison with the reference data; b) skeletal muscle, soft tissue, striated muscle and adipose tissue havedifferences lower than 20%; and c) compact bone, cortical bone and lung tissue differences are found above 50%.This introduction of a medium-specific Dose Point Kernel calculation method could potentially lead to futureimprovements on dosimetric systems, limiting for now this model to tissues with effective atomic number closed to liquidwater.