Quantification of differences in the effective atomic numbers of healthy and cancerous tissues: A discussion in the context of diagnostics and dosimetry

Abstract

As dose calculation approaches improve in accuracy, there may be an argument for the explicit inclusion of pathologies. This is more the case for breast, penile, prostate, nasopharyngeal, and stomach cancer, less so for testicular and kidney cancer. The calculated data suggest dual-energy computed tomography could potentially improve lesion identification in the aforementioned organs (with the exception of testicular cancer), with most import in breast imaging. Ultimately, however, the differences are very small. It is likely that the assumption of a generic "tissue ramp" in planning will be sufficient for the foreseeable future, and that the Z differences do not notably aid lesion detection beyond that already facilitated by differences in mass density.