Scintigraphic detection of oral cancer with early bone scintigraphic image

In 117 patients with oral cancer who were examined scintigraphically and histopathologically, the tumor blood flow was estimated scintigraphically immediately after administration of^99mTc-Hydroxymethylene-diphosphate (^99mTc-HMDP). The radioactivity was measured in the venous phase (30 to 40 seconds after administration) and in the blood pool phase (1 to 3 minutes), and the radioactivity ratios of the tumor to the control region in both phases, (venous ratio, VR and blood pool ratio, BPR, respectively) were calculated. The early image with^99mTc-HMDP (early image) was obtained 5 minutes after administration, and the image with⁶⁷Ga-citrate (Ga-image) was obtained 3 days after administration. Among the tumor classified histopathologically as showing rich, intermediate and poor vascularity, those with poor vascularity showed small VR (M±SD=0.97±0.08) and BPR (1.02±0.04), whereas those with rich vascularity showed large VR (1.39±0.01) and BPR (1.31±0.16). Early image demonstrating tumor was frequent among tumors with large VR (78%) and with large BPR (100%). Of tumors under 3 cm in diameter, 65% showed intermediate or rich vascularity and positive early image for tumor blood flow. These results suggest that the detection of small soft tissue tumors can be improved by combining the early image with the Ga-image.