Objectives To describe the impact that the coronavirus disease 2019 (COVID-19) pandemic had on the presentation of patients with head and neck cancer in a single tertiary care center. Study Design Retrospective cohort study. Setting Academic institution. Methods We performed a retrospective review of patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC) who presented as new patients between September 10, 2019, and September 11, 2020. Patients presenting during the 6 months leading up to the announcement of the pandemic (pre–COVID-19 period) on March 11, 2020, were compared to those presenting during the first 6 months of the pandemic (COVID-19 period). Demographics, time to diagnosis and treatment, and tumor characteristics were analyzed. Results There were a total of 137 patients analyzed with newly diagnosed malignancies. There were 22% fewer patients evaluated during the COVID-19 timeframe. The groups were similar in demographics, duration of symptoms, time to diagnosis, time to surgery, extent of surgery, and adjuvant therapy. There was a larger proportion of tumors classified as T3/T4 (61.7%) in the COVID-19 period vs the pre–COVID-19 period (40.3%) ( P = .024), as well as a larger median tumor size during the COVID-19 period ( P = .0002). There were no differences between nodal disease burden ( P = .48) and distant metastases ( P = .42). Conclusion Despite similar characteristics, time to diagnosis, and surgery, our findings suggest that there was an increase in primary tumor burden in patients with HNSCC during the early COVID-19 pandemic.

Background: This study evaluated whether fluorescence lifetime imaging (FLIm), coupled with standard diagnostic workups, could enhance primary lesion detection in patients with p16+ head and neck squamous cell carcinoma of the unknown primary (HNSCCUP). Methods: FLIm was integrated into transoral robotic surgery to acquire optical data on six HNSCCUP patients' oropharyngeal tissues. An additional 55-patient FLIm dataset, comprising conventional primary tumors, trained a machine learning classifier; the output predicted the presence and location of HNSCCUP for the six patients. Validation was performed using histopathology. Results: Among the six HNSCCUP patients, p16+ occult primary was surgically identified in three patients, whereas three patients ultimately had no identifiable primary site in the oropharynx. FLIm correctly detected HNSCCUP in all three patients (ROC-AUC: 0.90 ± 0.06), and correctly predicted benign oropharyngeal tissue for the remaining three patients. The mean sensitivity was 95% ± 3.5%, and specificity 89% ± 12.7%.Conclusions: FLIm may be a useful diagnostic adjunct for detecting HNSCCUP.

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INTRODUCTION Fluorescence-guided surgery can improve tumor identification and extent of surgical resection. 5-ALA is the standard for GBM, but is limited by lack of quantitative fluorescence, a need to work in the dark, and a lack of sensitivity for low grade tumors. We have developed a novel instrument for dye-free tissue autofluorescence lifetime imaging (FLIm) to identify glioma tissue during resection. This approach utilizes time-resolved autofluorescence measurements in narrow-band channels to assess markers of tissue metabolism. Compared to intensity-based imaging of exogenous fluorophores, FLIm has greater sensitivity without dependence on background lighting. The advantages of FLIm include quantitative tissue analysis, the ability to work under full light conditions, sensitivity for high and low grade gliomas, and the potential ability to identify IDH mutational status. In this study, we validated the use of FLIm for identification of glioma tissue at tumor resection margins. METHODS FLIm was used to image tissue margins during glioma resections and compared to microbiopsies from imaged regions to correlate fluorescence with histopathology. RESULTS FLIm was applied intraoperatively to 11 GBM and 5 LGG patients (7 imaged biopsies per patient). In GBM, tumor infiltration of cortex was associated with significantly decreased fluorescence lifetime (FL) in channels 2 (470/28nm;p<0.05) and 3 (542/50nm;p<0.002). In subcortical margins, FL was inversely proportional to the density of tumor in channels 2,3 (p<0.05). When IDH wild-type GBMs were compared to IDH1-mutant tumors, FL was noted to be significantly longer in channel 1 (390/40nm;p<0.05), and trended towards longer FL in channel 2, shorter FL in channel 3. In LGG, FL was significantly correlated with tumor density in channel 2 (p<0.01). CONCLUSIONS FLIm is a dye-free, quantitative alternative to 5-ALA for fluorescence guided glioma resections with sensitivity to high and low-grade tumors, and the ability to predict IDH mutations in GBM. Further validation studies are on-going.

Fluorescence lifetime imaging was used during open craniotomy procedures to detect differences between healthy and tumor-infiltrated brain. Optical parameters validated against histopathological biomarkers demonstrate that brain regions with infiltrative glioblastoma multiforme are characterized by longer lifetime values relative to the adjacent healthy tissues.