The differentiation between malignant and non-malignant breast tissues using elastic and inelastic scattering of synchrotron radiation

The aim of this work was to investigate the differences in composition between malignant and non-malignant breast tissue. 38 invasive ductal carcinomas and 45 non-malignant breast tissues were measured, each being mounted in cylindrical sample holders of volume 25mm2. The experiments were performed at the European Synchrotron Radiation Facility (ESRF) at Grenoble, France. A monochromatic beam of 10keV was used, focussed to a 0.5mm×0.5mm rectangular area on the sample. Elastic and inelastic scattered photons were collected at an angle of 120°. A novel technique was used to find the mean atomic numbers of the tissues (Z¯). A CT scanner that has been calibrated with an ED phantom was used to find the Z¯ of 10 gels. These were composed of a gelatine base, with low concentrations of copper added to increase the Z¯ values by an incremental amount. These were then used to calibrate the scattering measurement system. The area of the elastic and inelastic scatter peaks were found using peak fitting software and the ratio of these two areas was obtained. The data was shown to be non-parametric, and was therefore analysed using a Mann–Whitney test. Using this analysis the difference between non-malignant and malignant tissues was found to be extremely significant, with a 2-tailed p-value of <0.0001. The absolute Z¯ values were also analysed.