Technetium-99m Methoxyisobutyl Isonitrile Scintigraphy of Bone Metastasis in Three Patients with Differentiated Thyroid Cancer
We studied the usefulness of 99mTc-methoxyisobutyl isonitrile (MIBI) scintigraphy in the detection of bone metastases and in evaluation of therapeutical response to 131I-Na in three patients with differentiated thyroid cancer. On 99mTc-MIBI scintigraphy, increased accumulations were observed in all bone metastatic lesions (14 lesions), whereas on bone scintigraphy using 99mTc-hydroxymethylene diphosphonate (99mTc-HMDP) both increased (eight lesions, 57%) and decreased (six lesions, 43%) accumulations were observed. Within two months after 131I-Na treatment, all 14 lesions were unchanged on bone scintigraphy. However, on 99mTc-MIBI scintigraphy, disappearance of uptake (six lesions, 43%) and decreased uptake (seven lesions, 50%) were observed in 13/14 lesions (93%). Therefore, 99mTc-MIBI scintigraphy was useful not only in the detection of bone metastatic lesions but also in evaluation of the therapeutical response to 131I-Na in differentiated thyroid cancer.
