G9109 HCPCS - ONCOLOGY; DISEASE STATUS; HEAD AND NECK CANCER, LIMITED TO CANCERS OF ORAL CAVITY, PHARYNX AND LARYNX WITH SQUAMOUS CELL AS PREDOMINANT CELL TYPE; EXTENT OF DISEASE INITIALLY ESTABLISHED AS T1-T2 AND N0, M0 (PRIOR TO NEO-ADJUVANT THERAPY, IF ANY) WITH NO EVIDENCE OF DISEASE PROGRESSION, RECURRENCE, OR METASTASES (FOR USE IN A MEDICARE-APPROVED DEMONSTRATION PROJECT)