｀９９ｍ´Ｔｃ ＭＤＰシンチと｀６７´Ｇａシンチを用いた悪性腫よう骨浸潤症例の検討 高度に下顎骨浸潤した症例について

Abstract

Ten patients with intensely invaded malignant tumors at the mandibles were studied with bone scintigraphy (Tc-99m MDP) and Ga-67 citrate scintigraphy. All patients were classified by type of accumulation of both radionuclide pharmaceuticals. In almost all patients with invaded malignant tumors, bone scintigraphy revealed decreasing uptake in the center of the lesion and increasing uptake in the peripheral region. Ga-67 citrate scintigram showed increasing concentrated accumulation which was smaller than the area of Tc-99m MDP uptake in almost all cases. These types of accumulation were compared with those of other oral and maxillo-facial diseases. The patterns of accumulation of both radionuclide pharmaceuticals in ameloblastoma (3 cases), radicular cyst (3 cases), bone fracture (2 cases), diffuse sclerosing osteomyelitis (2 cases), and one sagittal ramus osteotomy case were different from that of bone involvement of malignant tumor cases. From the types of accumulation, we may be able to differentiate the oral and maxillo-facial diseases to some extent. In addition, the intensity of accumulation of Tc-99 m MDP was measured by using bone to soft tissue ratio (4 hrB/St ratio). The mean 4 hrB/St ratio was higher in moth-eaten absorbed type than in permeated type of resorption in roentgenogram. However, we could not obtain a definitive conclusion because of too few cases. The mean 4 hrB/St ratio in the bone involvement by malignant tumor was higher than that in radicular cyst, and lower than that of diffuse sclerosing osteomyelitis. Unfortunately, we could not differentiate each disease of the involved malignant tumor, ameloblastoma, or bone fracture by only the 4 hrB/St ratio. The Tc-99m MDP accumulated beyond the region where the radiolucencies exist in roentgenograms. We consider that both scintigraphies have a great role in planning surgical treatment, especially in selecting osteotomy.