This will be a prospective, open-label, one arm, single center two-stage adaptive trial designed to stop for either futility or efficacy after the first stage.~This approach will combine Diffusing Alpha Radiation Emitters seeds implantation along with standard treatment of Pembrolizumab for patients with recurrent unresectable or metastatic Head and Neck Squamous Cell Carcinoma (mHNSCC).~The DaRT seeds will be implanted in the target lesion and removed 15-22 days after implantation. Concurrently, patient will receive standard treatment of Pembrolizumab.~Disease evaluation will be assessed by a radiological imaging every 6 weeks starting at day 42 after the DaRT insertion procedure.
A unique combinational treatment for cancer employing intratumoral diffusing alpha radiation emitter device with check point inhibitor for recurrent unresectable or metastatic Head and Neck Squamous Cell Carcinoma