Prognostic Significance of FDG PET for Head and Neck Cancer Treated with IMRT

Materials/Methods: From October 1999 to April 2004, 151 patients with head and neck cancer were treated with IMRT for curative intent. One patient was lost to follow-up 2 months after treatment and excluded from analysis. Of the remaining 150 patients, 99 were treated with definitive IMRT and 51 received postoperative IMRT. Sites included were nasopharynx, 5; oropharynx, 56; larynx, 33; oral cavity, 29; hypopharynx, 8; nasal cavity/paranasal sinus, 8; and unknown primary, 11. None of patients treated with postoperative IMRT received chemotherapy. Of 99 patients who had definitive IMRT, 68 patients received concurrent cisplatin-based chemotherapy. One patient received induction cisplatin-based chemotherapy but no concurrent chemotherapy was given. Three target volumes CTV1, CTV2 and CTV3 were defined. The prescribed doses to CTV1, CTV2, and CTV3 in the definitive cohort were 70–74 Gy, 60 Gy and 54 Gy respectively. For high-risk postoperative IMRT, the prescribed doses to CTV1, CTV2, and CTV3 were 64–66 Gy, 60 Gy and 54 Gy respectively. For intermediate-risk postoperative IMRT, the prescribed doses to CTV1, CTV2 and CTV3 were 60 Gy, 60 Gy and 54 Gy. Sixty-six patients had FDG PET in staging workup before treatment, and 59 of them had SUV of the primary site available. The outcomes of these 59 patients were analyzed using Cox proportional model to determine the prognostic significance of the SUV.