Evaluation of oral potentially malignant disorders with autoflorescence, reflectance spectroscopy and vital staining and their correlation with histopathology -A hospital based prospective study.

Thesis Report.

ABSTRACT Background: Oral squamous cell carcinoma is frequently preceded by clinically identifiable Oral Potentially Malignant Disorders (OPMDs) that correspond with an increased risk of cancer. Early recognition and diagnosis of OPMDs by means of screening can help in early diagnosis hence, improve patient survival, reduce treatment-related morbidity and improve quality of life. The purpose of this study was to evaluate OPMDs with autofluorescence, reflectance spectroscopy and vital staining and correlate histopathologically. Materials and Methods: Forty nine patients (63 lesions) with OPMDs visiting Department of Oral Medicine and Radiology, BPKIHS were included in the study. After thorough history and oral examination, screening was done by Identafi® followed by toluidine blue staining then again by Identafi®. Then incisional biopsy under local anesthesia was performed from the site showing positive change. Lesions that displayed loss of autofluorescence (LOA) were considered to be positive and lesions that displayed no LOA or gain of autofluorescence were considered negative. Lesions with diffuse vasculature were considered to be positive and lesions without visible vasculature or with vasculature similar to the surrounding mucosa to be negative. Results: Out of 49 patients (63 lesions), Identafi®'s violet light detected 27 cases as true positives and 12 cases as true negatives. The overall sensitivity and specificity of Identafi®'s violet light was 73% and 46.2% and the positive predictive value and negative predictive value were 57.6 and 63.11. The diagnostic accuracy of Identafi®'s violet light was 61.90%. Identafi®'s greenamber light detected 29 cases as true positives and 4 cases as true negatives. The overall sensitivity and specificity of Identafi®'s green-amber light were 78.4% and 15.4% respectively. The positive predictive value and negative predictive value were 56.86 and 33.33. The diagnostic accuracy of green-amber light was 52.38 %. Toluidine blue identified 19 cases as true positives and 22 as true negatives. The overall sensitivity and specificity of toluidine blue were 51.4 and 84.6 and the positive predictive value and negative predictive value were 82.60 and 55 respectively. The accuracy was 65.08%. A statistically-significant association was observed between the toluidine blue and histopathology results, (p=0.04), p value set at ≤0.05. Conclusion: Identafi®'s violet light and green amber light is more sensitive in detecting true positives. Toluidine blue is highly specific in ruling out true negative cases. The screening of OPMDs will help in early diagnosis and further help in selecting biopsy site followed by proper early intervention and hence increasing the prognosis, outcome and decrease complication associated with it. Key words: Autofluorescence, Oral Potentially Malignant Disorders, Reflectance spectroscopy, Sensitivity, Specificity, Toluidine blue