In vivo electrical-impedance spectroscopy (EIS) readings in the human rectum

Abstract

Worldwide, colorectal cancer (CRC) is one of the leading causes of morbidity and mortality, ranking third among the most common cancers. Although screening programs are useful in reducing its impact, the screening tools available at present are far from being ideal. This justifies the search for new screening tools, and the authors think that Electrical Impedance Spectroscopy (EIS) could be a good candidate. It is a non- or minimally-invasive technique, safe, low cost and easy to use. At present, it is being introduced in cervical cancer screening programs in the UK, and has been tested in other types of cancer. In this preliminary study with a small sample of 17 human patients undergoing diagnostic total colonoscopy, we report the feasibility of using EIS for taking in vivo rectal readings. Four quadrant measurements were taken on each volunteer, a procedure that, in total, takes no more than 2 minutes, with minimal additional discomfort for the volunteers. After colonoscopy, 10 volunteers were considered as normal, 5 had polyposis, 1 had diverticulosis and 1 had disuse colitis. None was diagnosed as having cancer anywhere in the colon or rectum. A Multiple Range Test with Tukey HSD (Honest Significant Difference) shows a statistical significant difference between the readings obtained from the volunteer with disuse colitis when compared to the readings obtained from patients of the other three groups. In vivo EIS readings in humans can be obtained very easily and this opens the possibility of using it for further studies in the search of its possible application as an effective screening tool.