Radiation Protection Dosimetry Advance Access originally published online on June 18, 2007
Radiation Protection Dosimetry 2007 126(1-4):645-647; doi:10.1093/rpd/ncm130
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Microdosimetric study for interpretation of outcomes from boron neutron capture therapy clinical trials
1 Departments of Physics and Astronomy and Nuclear Engineering and Radiological Sciences
2 Department of Nuclear Engineering and Radiological Sciences
3 Department of Chemistry, and Department of Radiology, University of Tennessee Medical Center, Knoxville, Tennessee
4 Department of Medicine, University of Tennessee Graduate School of Medicine; Knoxville, Tennessee
* Corresponding author: lfmiller{at}utk.edu
Boron neutron capture therapy is a brachyradiotherapy utilizing the 10B(n,
)7Li reaction that has been used to treat glioblastoma multiforme (GBM), melanoma and colon carcinoma liver metastases. GBM clinical trials resulted in modestly improved life expectancies compared with conventional therapies. Early results trials focused on malignant melanoma and colon carcinoma provide dramatically better results. Macrodosimetry cannot explain these apparent differences. The dichotomy can only be understood using microdosimetry techniques. A computer program has been created to provide an improved tissue model. This model permits the dose in each cell's cytoplasm, nucleus, and the interstitium to be calculated for ellipsoidal cells placed in either random or ordered locations. The nuclei can be centered or eccentric. The new model provides insight into the micro level for differences in the trials. The differences arise from the tissue's cellular geometry and the effects of neighboring cells. These results help to explain the observed clinical outcomes.