Room: Exhibit Hall | Forum 5
Purpose: In non-small cell lung cancer, we use pathological volume as the gold standard to find the image volume closest to the pathological volume on FLT-PET/CT images.
Methods: Twelve patients with non-small cell lung cancer were treated with FLT-PET/CT scan before operation. The tumor specimens were cut by the thickness of about 4mm and stained with HE. The tumor area on each slice is delineated under microscope. The volume of the whole tumor (GTVpath) is the volume of each specimen. The volume shrinkage factors in the process of fixation are taken into account. The tumor volume (GTVpet) on PET images is automatically calculated by setting different SUV thresholds.
Results: The volume contraction rate of the tumor was 70.84% + 5.71% (60.4%~79.7%) during the immobilization of the specimens. The maximum value of SUV in all patients was 3.50 + 0.97 (range: 1.96~5.05), and the GTVpath of the tumor was 11.07 + 10.30 cm3 (2.39~33.10cm3). The best percentage and the best absolute value obtained by GTVpath are 56% + 11% and 1.84 + 0.33 respectively. It is found that there is a correlation between the threshold value of the best SUV absolute value and the maximum value of SUV (P=0.037), but the best percentage does not have this correlation (P=0.052).
Conclusion: When PLT-PET/CT is used for target mapping in non-small cell lung cancer, the maximum value of SUV 1.8 and 56% may be the threshold to determine the gross tumor volume boundary.
Not Applicable / None Entered.