The gold standard for oral cancer diagnosis is visual examination followed by biopsy and histological analysis of suspicious lesions. Now, researchers find that the need for biopsies can be halved when chemiluminescent illumination and toluidine blue staining are used in conjunction with visual examination. Significantly, the new approach accurately identified 100% of the abnormal lesions in a multicenter study.
Explore this issue:May 2007
This is the first multicenter study to look at this kind of device kit and to have histologic outcomes, said Joel Epstein, DMD, MSD, Director of the Interdisciplinary Program in Oral Cancer Biology, Prevention and Treatment at the Chicago Cancer Center, who led the trial. The results of this study provide additional information on the utility of this adjunctive technology.
The study was designed to determine whether the US Food and Drug Administration-cleared device kit, called ViziLite Plus with TBlue630, could reduce the number of suspicious lesions that required biopsy. Researchers enrolled 84 patients who were already scheduled to have a total of 97 suspicious lesions biopsied. Prior to the biopsy, the investigators used the kit-which includes a disposable chemiluminescent light source, an acetic acid solution, and pharmaceutical grade toluidine blue dye-to visualize the suspected lesions.
Prior to the biopsies, Dr. Epstein and colleagues recorded the brightness, sharpness, texture, and size of each lesion when visualized with the chemiluminescent light source following application of the acetic acid solution. They also scored each lesion for retention of toluidine blue, which adheres more readily to premalignant and malignant cells than to healthy ones.
Subsequent histopathology analysis showed that 43 lesions (44%) were benign, 34 (36%) had mild to moderate dysplasia, seven (7%) had severe dysplasia, four (4%) had carcinoma in situ, and nine (9%) had progressed to invasive squamous cell carcinoma.
When the researchers compared standard visual examination to visualization with the chemiluminescent light, they found that the new method improved the brightness or sharpness of 61% the lesions relative to standard visual examination. For example, 49 lesions appeared brighter with the new approach, of which nine had a serious pathology. Forty-eight lesions had sharper boundaries, of which seven had serious pathology.
Overall, however, the addition of the chemiluminescent visualization did not change the status of any of the lesions. With standard evaluation, there were 77 false positives and 20 true positives. The results with the chemiluminscence were the same, although one sample was missing from the analysis.