technetium-tc-99m-sulfur-colloid and Multiple-Myeloma

The authors present a case of multiple myeloma with intense hepatic and splenic uptake on Tc-99m HDP bone scan and discuss its clinical implications and possible uptake mechanisms. Tc-99m MIBI and Tc-99m sulfur colloid were used to demonstrate bone marrow involvement and focal lesions of multiple myeloma.

Topics: Bone and Bones; Humans; Liver; Male; Middle Aged; Multiple Myeloma; Radiopharmaceuticals; Spleen; Technetium Tc 99m Medronate; Technetium Tc 99m Sestamibi; Technetium Tc 99m Sulfur Colloid; Tomography, Emission-Computed, Single-Photon

LL1, a monoclonal antibody (MAb) to HLA Class-II-like antigen (li determinant) on the surface of B-lymphocytes, monocytes and histiocytes, was evaluated as an agent for bone marrow imaging. Six patients with diverse diseases (non-Hodgkin's lymphoma, n = 2; multiple myeloma, n = 1; polycythaemia vera, n = 1; lung cancer, n = 1; breast cancer, n = 1) were given low protein doses (< 1 mg) of 99Tcm (30 mCi) labelled Fab' of LL1. 99Tcm-sulphur colloid (SC) imaging was performed in three patients for comparison. Both planar and single photon emission tomographic images were acquired using Sopha gamma cameras. As early as 2 h post-MAb injection, excellent bone marrow images were achieved in all patients, demonstrating both normal or hyperproliferative marrow, as well as 'cold' bone marrow abnormalities such as radiation defects or cancer metastases. Similar to SC, relatively high uptake of LL1 was found in the liver and spleen. However, the bone marrow-to-liver and -spleen uptake ratios were approximately 19-fold higher (0.75 vs 0.04) and 6-fold higher (1.23 vs 0.22), respectively, with LL1 than with SC. The higher bone marrow uptake allowed clearly superior visualization of the thoracic spine when compared to SC. The mean T1/2 of blood and whole-body clearance were 0.4 and 66 h, respectively. The highest radiation absorbed doses (in cGy mCi-1) were observed in the spleen (0.47 +/- 0.24), kidneys (0.25 +/- 0.09) and liver (0.14 +/- 0.04). The bone marrow dose was only 0.05 +/- 0.02 cGy mCi-1. These results indicate that bone marrow imaging with 99Tcm-LL1 is feasible, and that LL1 may be a suitable alternative to SC because of better visualization of the lower thoracic spine. Potential applications include the improved detection of bone marrow metastases of solid tumours and the assessment of haematological disorders.

Topics: Animals; Antibodies, Monoclonal; Bone Marrow; Breast Neoplasms; Female; Humans; Lung Neoplasms; Lymphoma, Non-Hodgkin; Mice; Multiple Myeloma; Neoplasms; Polycythemia Vera; Radioimmunodetection; Technetium; Technetium Tc 99m Sulfur Colloid; Tissue Distribution; Tomography, Emission-Computed