Concomitant intraarterial chemoradiotherapy for head and neck cancer evaluated by FDG-PET

To evaluate the effectiveness of combined intraarterial chemotherapy (THP-ADM, 5-FU, and carboplatin) and radiotherapy on head and neck squamous cell carcinomas using positron emission tomography with 18F labeled fluorodeoxyglucose (FDG-PET). Twenty-three patients with squamous cell carcinoma of the head and neck were included in the study. All patients completed the treatment regimen, and underwent 2 FDG-PET prior to and 4 weeks after chemoradiotherapy. The pre- and posttreatment PET images were compared with clinical and histopathological evaluations of the treatment effect. For the quantitative evaluation of regional radioactivity, standardized uptake values (SUVs) were used. The overall clinical response rate to the chemoradiotherapy was 100% (CR rate: 78.3%). Prior to treatment, FDG-PET detected neoplasms in all 23 patients. The neoplastic lesions showed high SUVs (mean: 9.15 mg/ml) prior to treatment, which significantly decreased after therapy (3.60 mg/ml, p<0.01, paired student t-test). Lesions with higher pretreatment SUVs (greater than 7 mg/ml) showed residual viable tumor cells after treatment in 4 out of 15 patients, whereas those with lower SUVs (less than 7 mg/ml 8 patients) were successfully treated. Four out of 9 tumors with posttreatment SUVs greater than 4 mg/ml had viable tumor cells, whereas all (14/14) tumors with post-SUVs less than 4 mg/ml showed no viable cells. With concomitant chemoradiotherapy monitored by FDG-PET, 8 patients avoided operation altogether, and the remaining 15 patients underwent a reduced form of surgery. Twenty patients survived (20/23, 87%) without recurrence. Concomitant chemoradiotherapy is effective for head and neck carcinoma. Pretreatment FDG-PET is useful for predicting the response to treatment. Posttreatment FDG-PET can evaluate residual viable cells. Thus FDG-PET is a valuable tool in the treatment of head and neck tumors. (author)