X-ray fluorescence microtomography analysis of breast tissue samples under various excitation conditions

The fluorescence mapping of iron, copper and zinc can be very important in diagnoses, because the biochemistry of these elements suggests that these metals may play an important role in carcinogenesis. However, until now the evidence linking iron, copper and zinc to cancer is far from being conclusive and further research is needed. This work presents a development system to study fluorescence microtomography at the X-Ray Fluorescence Facility (D09B-XRF) at the Brazilian Synchrotron Light Laboratory (LNLS), Campinas, Brazil. A white beam (423 keV), a monochromatic beam produced by a Si (111) at 9.8 keV and a quasi-monochromatic beam produced by a multilayer monochromator at 12 keV were used to sample excitation. The fluorescence photons were collected with an energy dispersive HPGe detector placed at 90 degrees to the incident beam, while transmitted photons were detected with a fast scintillation counter placed behind the sample on the beam direction. In order to find an improved diagnostic technique for a cancer and other diseases using fluorescence mapping of iron, copper and zinc, breast tissue samples and reference samples made of polyethylene and standard solutions were analyzed. The elemental map of iron, copper and zinc were obtained by non-destructive X-Ray fluorescence microtomography.