Potential novel application of dual time point SUV measurements as a predictor of survival in head and neck cancer.

Objectives To examine the potential of pre-treatment dual time point [ 1 8 F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) as a tool for improving the assessment of head and neck cancer. Two main areas were investigated: (a) optimum time to start FDG scanning post-injection and (b) potential of SUV obtained from dual time point scanning as a prognostic indicator of survival. Methods Twelve patients with advanced head and neck cancer were prospectively studied. Each patient was scanned using a Siemen's Ecat Exact-47 PET scanner at 1 h and 2 h post-injection. Maximum tumour uptake (SUV t ) and ratio of maximum tumour/normal tissue uptake (SUV t / n ) were recorded. The optimal time to initiate scanning was investigated by comparing SUV t and SUV t / n with the decision made by two experienced observers as to which scan they preferred to report from, given the choice of the 1 h and 2 h scan in each patient Results A significant difference between 1 h and 2 h SUV t (P< 0.004, paired t-test) and between 1 h and 2h SUV t / n (P< 0.0003, paired t-test) was observed. All 2h SUV, and SUV t / n were greater in magnitude than their respective 1 SUV t and SUV t / n counterparts. The two observers reported an identical number of lesions from the 1 h and 2 h scans but preferred the 2 h data. Conclusions Tumour stage and the percentage difference in 1 h and 2 h SUV t showed potential as prognostic indicators of long-term survival.