Physics supporting bone cancer diagnosis

A collaboration between the Cnr Institute of biophysics and the Department of translational research and new technologies in medicine and surgery of the University of Pisa has allowed to demonstrate that Raman spectroscopy is able to diagnose the various levels of malignancy of the chondrosarcoma. Chondrosarcoma denotes a term indicating different types of bone cancers that originate from transformed cartilage cells. Whereas Raman spectroscopy is a technique discovered by the Indian physicist Chandrasekhara Raman and used by physicists and chemists to investigate the matter.

The research, published in the journal Scientific Reports of the publisher Nature, was carried out by Mario D’Acunto of the Cnr Institute of biophysics of Pisa, first signatory of the publication, and by professors Alessandro Franchi, Raffaele Gaeta and Rodolfo Capanna of the Department of translational research and new technologies in medicine and surgery of the University of Pisa. In particular, the contribution of the Institute of biophysics was to apply Raman spectroscopy to the chondrosarcoma samples provided by physicians. Raman spectroscopy also required a massive use of multivariate statistics, as Ibf contribution, in particular, the Principal analysis components and the Linear discriminant analysis, statistical techniques that made it possible to uniquely classify the various degrees of malignancy of the chondrosarcoma. Not only that, these statistical techniques have also made it possible to discriminate between the grade 1 of chondrosarcoma malignancy and the Enchondroma, the latter, benign tumor tissues of the chondrosarcoma.

Example of identification of hydroxyapatite in grade 1 Condorsarcoma calcification: on the left an image of the morphology and on the right the corresponding biochemical map around the identification peak of hydroxyapatit

Raman spectroscopy is a technique that uses laser light to illuminate the samples under investigation, and collect the light emitted by the molecular vibrations of the samples themselves, through a physical process that closely resembles the process that makes our sky blue.
When applied to cancer diagnosis, Raman spectroscopy allows to highlight the biochemical differences between healthy and tumor tissues and giving the possibility to classify the various degrees of malignancy of the chondrosarcoma. Raman spectroscopy also allowed highlighting several tumor-related processes such as cartilage degradation processes and progressive cell proliferation as the degree of malignancy of the chondrosarcoma increased. Although it is an uncommon bone cancer, chondrosarcoma cannot be treated with chemotherapy, but generally requires surgery. A precise evaluation of the degree of malignancy is fundamental for subsequent clinical treatments and according to the results of this research, the future diagnosis of chondrosarcoma could exploit an important new tool. Indeed, future studies, already foreseen by the authors of the publication, will aim to highlight further critical points in the diagnosis of chondrosarcoma and to make the technique easier for doctors to use.