Local treatment for cervical intra-epithelial neoplasia (CIN) involves the removal of the affected part of the tissue and is >95% effective in preventing re-invasive disease. However, removal of part of the cervix is linked to significant adverse sequelae, including preterm birth; with cone depth and radicality of treatment correlating to the frequency and severity of adverse events. Since pre-treatment cervix length vary amongst women, the percentage of cervix excised may correlate more accurately to risk than absolute dimensions. Attenuated total reflectance, Fourier-transform infra-red (ATR-FTIR) spectroscopy detected that treatment for CIN significantly alters the biochemical fingerprint in the cervix, compared with women who have not had treatment; this is due to the excision of cervical tissue rather than a disease controlling effect. However, the spectra did not correlate to the cone depth or proportion of cervical length excised. Post-hoc analyses of patient characteristics found that spectral absorbance was different for treated women according to whether they were current/non-smokers; nulliparous/parous; by luteal/follicular phase; and by combined oral contraceptive pill use; these patient characteristics are likely to have affected the excisional outcomes. As traditional IR techniques are limited by the effect of diffraction of ~3 μm to 30 μm, we assessed the potential of scanning near-field optical microscopy in combination with an IR free electron laser (SNOM-IR-FEL), in determining the biophysical properties of abnormal cervical cells. SNOM-IR-FEL is able to distinguish between normal and various grades of cervical abnormalities at designated wavelengths associated with DNA, amides I and II and lipids, at spatial resolutions below the diffraction limit (≥0.2 μm)
