Source: www.curetoday.com Author: staff In patients with advanced squamous cell carcinoma of the head and neck, negative findings on post-treatment positron emission tomography/computed tomography (PET-CT) predict a good treatment response, researchers say. In 31 patients with clinical stage III and IV tumors treated with cisplatin and concurrent external beam radiotherapy, PET-CT was performed 6 to 8 weeks after therapy was completed, along with a comprehensive physical examination of the head and neck, as reported by Dr. James P. Malone, from the Southern Illinois School of Medicine, Springfield, and colleagues in the November Archives of Otolaryngology -- Head and Neck Surgery. Seventeen patients had evidence of persistent disease on physical exam, CT, and/or PET-CT, and these individuals had surgery for further evaluation. Fourteen patients had complete clinical responses, including no evidence of FDG uptake on PET-CT; these subjects were observed with routine follow-up. According to the researchers, all but one of these 14 patients remained disease free at the primary tumor site during a median follow-up of 26 months. Thus, the authors point out, the sensitivity of PET-CT was 83%, and its negative predictive value was "excellent" at 92% for detection of persistent disease at the primary tumor site. Because of a high false-positive rate, specificity was low at 54%, with a positive predictive value of 31%. Dr. Malone's group attributes the high false-positive rate to inflammation related to recent treatment. The investigators also note that 5 of 16 patients with abnormal FDG update developed local disease. "For patients with abnormal [...]