Early Treatment Response Monitoring Using 2-Deoxy-2-[¹⁸F]fluoro-D-glucose Positron Emission Tomography Imaging during Fractionated Radiotherapy of Head Neck Cancer Xenografts

Table 1

Pretreatment tumor volumes and PET parameters (calculated based on the maximum voxel activity).

Characteristics	Local control; median (range)	Local failure; median (range)	𝑃^†
Number	6	4	—
Volume*	656 (479–1212)	704 (530–1016)	NS
SUV^∗max	1.47 (1.14–2.05)	1.51 (1.31–2.02)	NS
RI^∗max	0.22 (−0.07–0.36)	0.36 (0.05–0.48)	NS
SF^∗max	0.12 (−0.06–0.21)	0.17 (0.05–0.25)	NS
Ki^∗max	0.014 (0.011–0.023)	0.018 (0.014–0.023)	NS

∗Volume: tumor volume as determined from the CT scan, SUV_max: standard uptake value determined from the maximum voxel activity, RI_max: retention index determined from the maximum voxel activity, SF_max: sensitivity factor determined from the maximum voxel activity, Ki_max: kinetic index determined from the maximum voxel activity.
^†𝑃: assessed using the Wilcoxon test, NS: not significant.