Infrared imaging in histopathology: Is a unified approach possible?

BACKGROUND: infrared imaging has emerged as a new promising tool in histopathology to provide label free analysis of tissue sections. Interestingly, infrared imaging has the potential to measure many markers at the same time, on one section, without staining. It has been demonstrated to deliver accurate results in numerous cancer pathologies. Yet, today, it is not used in routine diagnostics. The gap between the demonstrated potential and the applications is striking. The reasons why FTIR imaging is not used in the clinics are multiple but one of them is a major obstacle: the diversity of sample preparation, image recording parameters and pre-analytical methods used by the different research groups. This diversity prevents comparison of data and thereby the large scale validation necessary to enter the medical world. OBJECTIVE: we will briefly review here the main aspects of data acquisition and processing used in infrared imaging of tissue sections for which a common approach should be considered. RESULTS: considering requirement for spectral histopathology, the development of the technology and the literature on this topic, guidelines ruling sample preparation and pre-analytical methods do emerge. CONCLUSIONS: consensus values are proposed for most parameters whose current diversity prevents the exchange of data among institutions and thereby the validation of the method on a large scale.