SignificanceIncomplete surgical resection of tumors using white light and preoperative imaging causes tumor reoccurrence. Antibody-dye conjugate can target and accumulate into the tumor but has longer wait times for surgery following administration. This process can be expedited using PDP which not only increase the delivery but also improves the diagnostic accuracy in tumor detection. ApproachThe mice bearing FaDu head and neck tumors were administered with Cetuximab-IRDye800 (Cet-IRDye800) and treated with sub-therapeutic dose of PDT (photodynamic Priming; PDP). The accumulation and distribution of Cet-IRDye800 into the tumor were measured and analyzed. ResultsPDP improves and expedites the delivery of Cet-IRDye800 into the tumors significantly. It also improves diagnostic accuracy in tumor detection with respect to the vicinal salivary gland. ConclusionsThis study highlights, for the first time, that PDP enhances the rate and extend of delivery of the fluorescently labeled antibodies for the effective photodynamic image guided surgery.