Correlation Between the Uptake of Tc-99m-sesta MIBI and Prognostic Factors in Patients with Multiple Myeloma
Reviewer: Eric Shinohara MD, MSCI
Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 23, 2007
Presenter: Bacovsky, J.M.
Presenter's Affiliation: University of Olomouc, Czech Republic
Type of Session: Scientific
- Multiple myeloma (MM) is a malignant disease characterized by clonal proliferation and accumulation of transformed B-line elements. MM cells can produce monoclonal immunoglobulin (MIG) that can be detected in the serum and/or urine.
- Osteopenia, pathological fracture, and plasmacytomas (extramedullary disease) are associated with MM and can be seen on radiological imaging, however not always. Functional imaging may be more sensitive and can determine the activity of the disease.
- Technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) has been shown to be useful in identifying several types of tumors, such as breast cancers, brain cancers, thyroid gland malignancies, malignant lymphomas and MM.
- The purpose of this prospective study was to determine if 99mTc-MIBI imaging correlated with known biochemical and hematological markers for MM activity.
Materials and Methods
- 102 patients with MM and 32 patients with MGUS were imaged using 99mTc-MIBI. The resulting 99mTc-MIBI imaging was divided into four categories, N which was defined as physiologic uptake, D defined as diffuse uptake, F defined as focal uptake and D+F, which was a combination of diffuse and focal characteristics. In addition to this, extension and intensity were scored using a 1-3 scale. These factors were combined to form a summary score (SS).
- In addition to imaging, numerous prognostic markers for MM disease activity were collected for each patient.
- A statistically significant correlation was found between the SS of 99mTc-MIBI scintigrams and beta2-microglobulin (p < 0.001), monoclonal immunoglobulin level (MIG) (p< 0.001), serum thymidinekinase (sTK) (p < 0.001), C-reactive protein (CRP) (p < 0.05), cross-linked carboxyterminal telopeptide of type I collagen (ICTP) (p< 0.05), bone marrow plasmocytosis (Pb) (p < 0.001) and hemoglobin (Hb) ( p < 0.001).
- All 32 patients with MGUS were scored as N on 99mTc-MIBI scintigrams.
- 99mTc-MIBI is a useful indicator of MM activity and helps in differentiating between MM and MGUS.
- In the present study the authors found that the 99mTc-MIBI SS correlated with known markers for MM disease activity and was able to differentiate MM from MGUS. Further prospective studies are needed to evaluate the validity of the SS, and may also allow further fine tuning of the SS.
- Functional imaging would allow for the detection of new lesions and provide information about the activity of lesions, which could be used to assess response to treatment. A study to determine how PET imaging correlates with various biomarkers for MM activity would be of interest to see how PET compares with 99mTc-MIBI.
- Direct comparison of PET imaging with 99mTc-MIBI’s ability to detect active disease could also be done to compare the effectiveness of these two modalities for the functional imaging of MM. Advantages of 99mTc-MIBI are that it is cheaper than PET and may be better able to visualize skull lesions as the brain uptake would not interfere with the imaging.