In the phase I of the study, increasing concentrations of PARPi-FL will be used in up to 12 patients with OSCC to determine concentration that results in the highest contrast between tumor and normal mucosa. Dose escalation will be performed in groups of three patients until image contrast decreases, side effects are noted or the concentration of PARPi-FL exceeds 1μM. Imaging will be performed in the Department of Surgery during a presurgical visit including clinical examination of the oral cavity. In the phase II part of the study the concentration of PARPi-FL determined in phase I will be used to image 18 patients with OSCC on the day of surgery. Imaging findings will be correlated with histopathologic findings in the surgically resected specimens.

For PARRi-FL, imaging patients will first gargle a solution of PARRi-FL for 1 min, then spit out this solution and gargle with a cleaning solution (the solvent used for PARRi-FL) for 1 min. Then fluorescence imaging of the oral cavity and pharynx will be performed with an endoscope. The intensity and extent of the fluorescence signal will be recorded by one of the investigators for the tumor and adjacent normal mucosa.

toxicity data relevant to study interventions (CTCAE v 4.0)