Linear correlation between patient survival and decreased percentage of tumor [(18)F]fluorodeoxyglucose uptake for late-course accelerated hyperfractionated radiotherapy for esophageal cancer.

ABSTRACT

PURPOSE: The aims of this trial were to study whether a decreased percentage of tumor fluorodeoxyglucose (FDG) uptake (%DeltaSUVmax) correlated with overall survival and local control times for patients with esophageal cancer and which patients would benefit from a late-course accelerated hyperfractionated (LCHF) radiation scheme. METHODS AND MATERIALS A total of 50 eligible patients with squamous esophageal cancer received positron-emission tomography examinations three times and were treated with the LCHF radiation scheme, with a dose of 68.4 Gy/41 fractions in 6.5 weeks. A %DeltaSUVmax value was calculated, and patients were stratified as highly radiosensitive (HR), moderately radiosensitive (MR), and low radiosensitivity (LR) according to %DeltaSUVmax values in the conventional fraction (CF) scheme. Then, a linear correlation was calculated between patients' survival time and %DeltaSUVmax. Local control and overall survival rates were compared after stratification. RESULTS: In the MR subgroup, there was no linear correlation between %DeltaSUVmax and the CF and LCHF schemes (correlation coefficient, R < 0.4; p > 0.05). In the other subgroups (HR and LR), %DeltaSUVmax values between the CF and LCHF schemes were correlated. Also, in the HR and LR subgroups, %DeltaSUVmax after radiation correlated with overall survival or local control rates (correlation coefficient, R ＞0.5, and p < 0.05). Three-year local control rates in the HR, MR, and LR subgroups were 100%, 81.5%, and 0%, respectively (p < 0.001). Also, 3-year overall survival rates were 92.4%, 58.8%, and 0% for HR, MR, and LR subgroups, respectively (p < 0.001). CONCLUSIONS: Postradiation %DeltaSUVmax was positively correlated with survival time for patients' with esophageal cancer. Patients who benefited from LCHF schedules were those with a decrease of 30% to 60% in tumor FDG uptake after the completion of CF radiation.