Comparison of 99mTc-MDP and 99mTc-MIBI whole body scans for diagnosis of widespread skeletal metastases [Persian]

Skeletal metastasis is one of the most important disabling complications of the malignant diseases. As in general, the survival of patients with osteometastatic lesions is relatively long, an early diagnosis can lead to improve the patient’s life, both quantitatively and qualitatively, and prevent exacerbation of the disease and disabling complications. In this study, 22 patients with established diagnosis of malignant disease and clinical manifestations of skeletal metastasis were evaluated both with 99mTc-MIBI and 99mTc-MDP whole body scans, in two separate phases. Patients’ diagnoses were as following: Small Round Cell Tumor, Breast carcinoma, Nasopharynx carcinoma and Multiple Myeloma. In the first phase of the study a whole body bone scan was performed by IV injection of 740MBq 99mTc-MDP. After a period of 1 week a whole body scan was carried out by 99mTc-MIBI for all the patients. No treatment such as radiation therapy or chemotherapy was done in this 1 week interval. The number and intensity of the scan findings were compared visually, according to the three-phase staging, subsequently. Whole body survey with 99mTc-MIBI in 14 out of 22 patients were positive, demonstrating only 44.4% of bony lesions established on whole body bone scan with 99mTc-MDP. The mean value of intensity of radiotracer uptake, was around 1.5+ (Mild to moderate). On the other hand in 7 patients with positive 99mTc-MIBI scan some hidden soft tissue lesions (Mostly lymph nodes) were detected with intensity of 2+. So this study shows that whole body bone scan is preferable for detection of widespread metastasis comparing with 99mTc-MIBI whole body scan. The singnificance of 99mTc-MIBI scan is mainly limited to some equivocal of soft tissue lesions.