Approximately 13,000 cases of invasive cervical cancer will be diagnosed in the United States, in 2002, and approximately 4,100 women will die from the disease. The 5-year relative survival rate for the earliest stage of invasive cervical cancer is 91%. The overall (all stages combined) 5-year survival rate for cervical cancer is about 70%. For cervical precancer the 5-year survival rate is nearly 100%. Thus, early detection of cervical precancerous lesions can have a dramatic impact on cervical cancer mortality rates, increasing five-year survival rates from 70% to about 100%. Routine Papanicolaou (Pap) smear is the current standard for cervical cancer and pre-cancer screening, however, a number of studies have indicated that this method may miss as many as 20-30% of cervical cancers. For this reason, tissue autofluorescence examination of cervical tissue has been examined as a means for increasing sensitivity to early neoplastic changes in the cervix. While sensitivity of this technique can be as high as 85-90%, its specificity is low resulting in significant numbers of false positives. Optical coherence tomography (OCT) is a new non-invasive imaging technique which can image morphological details of soft tissues with resolution close to that of conventional light microscopy. However, the time and small imaging field associated with OCT make it impractical for routine screening by itself. Previously, in an animal model of epithelial cancer, we have demonstrated that the use of tissue autofluorescence imaging used to guide selective application of OCT imaging results in a technique with superior sensitivity and specificity over fluorescence imaging alone. We hypothesize that fluorescence image guided OCT (FIGOCT) may become a useful clinical tool for the evaluation and screening of cervical tissues. In this proposal we design, build, and test a new optical probe suitable for exploring the feasibility of FIG-OCT in the human cervix. Such a probe would be useful in detecting epithelial cancers in other easily accessible sites in the body including the urinary tract, bladder, gastro-intestinal tract, colon, and oral cavity.
