Optical Diagnostics
and Medical Informatics Laboratory
Apart from enormous efforts put in
understanding, prevention and treatment, cancer remains a leading cause of death
in developed countries. In addition
to the obvious personal cost, cancer represents a significant economic burden to
the state through both direct (diagnosis, therapeutics surgery etc.) and
indirect (long term disability payments, taxation, revenue lose due to premature
death etc.) costs. Perhaps, the most effective way to reduce both the personal
and economic burden associated with cancer is early, accurate detection of the
disease. Accurate early diagnosis potentially allows intervention when the
disease is least aggressive, improving the chances of survival.
The current methods of diagnosis of cancer
include a) tissue contrast b) physical examination c) MRI. Microscopic
examination of sections of tissue requires processing of tissues (fixation,
sectioning and staining) prior to analysis. The physical examination of patients
is inherently subjective and relies upon the experience of the physician. MRI,
the youngest of these techniques is too expensive to be used for routine
screening purpose.
Infrared radiation, which is noninvasive
and harmless is absorbed by tissues, fluids and cells to promote vibration of
the covalent bonds of molecules within the sample. The wavelength of infrared
radiation, which is absorbed, depends upon the nature of the covalent bond,
(i.e., atoms involved and the type of bond) and the strength of
any intermolecular interactions van derWaal’s interactions, H-bonding).
The IR spectrum of a sample is, therefore, a biochemical fingerprint.
As the biochemistry of cells, tissues and fluids must change during
disease (there can be no disease without abnormal biochemistry), then the
biochemical fingerprint of cells, tissues and fluids should be altered in the
disease. This has been demonstrated in the case of Myocardial infarction and
arthritis etc.
Recently in the past few years, FTIR has been used in the diagnosis of cancer. Gao.,T et.al. has carried out the FTIR study of human breast, normal and carcinomal tissues. They report that their method of analysis results in nearly 100% diagnostic accuracy of carcinomal tissues from normal ones. The chronic lymphocytic leukemia could be well characterized by FTIR based on lipid and DNA content and the overall spectral characters. Also the diagnosis of lung cancer was done using FTIR by measuring the ratio of the peak intensities of the 1030 cm-1 and 1080 cm-1 bands (originated mainly in glycogen and phosphodiester groups of nucleic acids respectively) which differs greatly between normal and lung cancer samples. The grading of lymphoid tumors could be achieved by FTIR microscopy. The examples mentioned above clearly suggest that FTIR can be a powerful tool in the diagnosis of cancer. The main advantages of this technique are simplicity, quick results and economic viability.
