An imaging-based approach to cancer-therapy-induced mucositis

Objectives: A preliminary study to assess non-invasive Optical Coherence Tomography (OCT) for early detection and evaluation of chemotherapy-induced oral mucositis in 48 patients, 12 of whom developed clinical mucositis. Methods: In 48 patients receiving neoadjuvant chemotherapy for primary breast cancer, oral mucositis was assessed clinically, and imaged using non-invasive OCT. Images were scored by 3 blinded pre-standardized scorers using a novel imaging-based scoring system ranging from 0-6 based on changes in tissue surface and subsurface microstructure observed from the in vivo OCT images. Conventional clinical assessment using the Oral Mucositis Assessment Scale (OMAS) scale was used as the gold standard. Patients were evaluated on days 0,2,4,7,11 after commencement of chemotherapy. Results: The following events were identified using OCT: (1) change in epithelial thickness and subepithelial tissue integrity (beginning on day 2), (2) loss of surface keratinized layer continuity (beginning on day 4), (3) loss of epithelial integrity (beginning on day 4). For the Imaging Score, differences between each pair of successive time points were significant with p<0.0005 using the Kruskal-Wallis nonparametric test, which is appropriate given the small numbers. This means that the Imaging Scoring Approach was capable of mapping accurately and effectively the severity of the mucositic condition. Imaging data gave higher scores compared to clinical scores earlier in treatment, suggesting that the imaging-based diagnostic scoring was more sensitive to early mucositic change than the clinical scoring system. Once mucositis was established, imaging and clinical scores converged: correspondence was good at days 7 and 11 (non-significant Wilcoxon rank-sum test and moderate Spearman and Pearson correlation coefficients). Conclusions: Chemotherapy-induced oral changes were identified prior to their clinical manifestation using OCT, and the proposed scoring system for oral mucositis was validated for the semi-quantification of mucositic change.