SWIR windows as an adjunctive to biopsy for distinguishing and monitoring benign and malignant tissues

The short wavelength infrared (SWIR) region (1000-2500 nm) has three near-infrared (NIR) windows (1100-1350 nm, 1600-1870 and 2100-2350 nm). These windows have received increased attention in imaging and spectroscopy. We investigated the total attenuation lengths (lt) (based on absorption and scattering properties of light) through human normal and malignant prostate and breast tissues. It was found, using window III (at a wavelength of 1700 nm), that lt from prostate normal and cancerous tissues were 589 and 216 microns, whereas lt from breast normal and cancerous tissues were 271 and 106 microns. This non-invasive SWIR technique can show how prostate and breast cancer are different from normal prostate and breast. This could be important for patients who have hundreds of potential tumors, in which numerous biopsies are not possible. Important examples include patients with multiple skin, lung or bowel lesions. For example, patients with Von Recklinghausen’s Disease (neurofibromatosis), which occurs in about one in 2800 people, may have multiple (perhaps hundreds) of benign tumors, but have a markedly increased risk of developing cancer. These lesions are far too many to biopsy. Patients may be multiple lipomas. Many patients have numerous polyps in the small or large bowel which are not malignant, but may become so. It is very common in parts of the country that many inhabitants there have multiple “cannonball” lesions on chest x-ray that may be cancer, sarcoidosis or areas of fungal (coccidioidomycosis, histoplasmosis, aspergillosis etc.) accumulation. In addition, when patient has multiple lesions, they can also be monitored at frequent intervals to see if there are changes in any suspicious lesions.