A note on Poisson goodness-of-fit tests for ionizing radiation induced chromosomal aberration samples

Area of Science:

• Cytogenetics
• Radiation Biology
• Biostatistics

Background:

• The u-test is the standard for assessing chromosomal aberrations in biodosimetry.
• Assessing exposure homogeneity is crucial for accurate dose estimation.
• Limitations of asymptotic tests in small sample sizes are a concern.

Purpose of the Study:

• Introduce Poisson exact goodness-of-fit tests as alternatives to the u-test.
• Evaluate the performance of these tests in cytogenetic biodosimetry.
• Provide tools for implementing exact tests.

Main Methods:

• Implemented three Poisson exact goodness-of-fit tests in R.
• Utilized a Shiny R Studio application (GOF Poisson) for support.
• Applied exact tests and the u-test to patient data with chromosomal aberrations.

Main Results:

• The u-test is not suitable for small samples with low aberration yields.
• Exact tests provide a more appropriate approximation in such cases.
• Computational tools for exact tests are now available.

Conclusions:

• Poisson exact goodness-of-fit tests should complement the u-test.
• These tests enhance the detection of inhomogeneous exposures in biodosimetry.
• Improved accuracy in cytogenetic biodosimetry is achievable with exact tests.