[A study of irradiated spines in radiotherapy--using 99mTc-HMDP bone scintigraphy & MR imaging].
When radiation therapy is performed on a patient with malignant tumor, vertebral spines are sometimes included in the irradiation field. In the present study, 99mTc-HMDP uptake was examined in 102 cases of malignant tumors treated with radiation therapy (irradiated total doses from 10 to 70 Gy) in order to clarify the time course of accumulation. The scintigram on the film was transformed with a film digitizer into objective data, and the Accumulation Decreasing Index (ADI) was calculated each month after irradiation. In the group receiving less than 30 Gy, recovery of 99mTc-HMDP accumulation was seen after a mild decrease in the ADI. However, in the group that received more than 40 Gy, no recovery of accumulation was seen, and a large decrease in the ADI followed. Vertebral MRI was performed with and without Gd-DTPA enhancement to calculate the vertebral Signal Intensity Ratio (SIR), and decreased blood flow in the irradiated bone marrow was estimated from the changes in SIR values. In the irradiated area, no definite abnormal accumulation of 99mTc-HMDP was observed against the new metastatic bone tumor. In such cases, MRI should be performed soon after bone scintigraphy in order to detect the tumor.
Yoshida
D
D
Department of Radiology, Kochi Medical School.
Sawada
A
A
Kamiike
O
O
Ogawa
Y
Y
Maeda
T
T
Yoshida
S
S
D001853:Bone Marrow / Q000473:pathology; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008961:Models, Structural; D011877:Radionuclide Imaging; D011879:Radiotherapy Dosage; D013131:Spine / Q000000981:diagnostic imaging / Q000528:radiation effects*; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives*
C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate