Focal MIBI uptake is a better indicator of active myeloma than diffuse uptake

International myeloma working group consensus statement and guidelines regarding the current role of imaging techniques in the diagnosis and monitoring of multiple Myeloma

Several imaging technologies are used for the diagnosis and management of patients with multiple myeloma (MM). Conventional radiography, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine imaging are all used in an attempt to better clarify the extent of bone disease and soft tissue disease in MM. This review summarizes all available data in the literature and provides recommendations for the use of each of the technologies. Conventional radiography still remains the 'gold standard' of the staging procedure of newly diagnosed and relapsed myeloma patients. MRI gives information complementary to skeletal survey and is recommended in MM patients with normal conventional radiography and in all patients with an apparently solitary plasmacytoma of bone. Urgent MRI or CT (if MRI is not available) is the diagnostic procedure of choice to assess suspected cord compression. Bone scintigraphy has no place in the routine staging of myeloma, whereas sequential dual-energy X-ray absorptiometry scans are not recommended. Positron emission tomography/CT or MIBI imaging are also not recommended for routine use in the management of myeloma patients, although both techniques may be useful in selected cases that warrant clarification of previous imaging findings, but such an approach should ideally be made within the context of a clinical trial.

MDR1, MRP1 and LRP expression in patients with untreated acute leukaemia: Correlation with 99mTc-MIBI bone marrow scintigraphy

BACKGROUND

Chemotherapy failure linked to multidrug-resistance (MDR) plays an important role in many cancer types, including leukaemia. It is believed that overexpression of some of membrane or intracellular proteins confers the MDR phenotype to cancer cells. (99m)Tc-sestamibi (MIBI) is a transport substrate for the Pgp pump. We assessed the bone marrow uptake of (99m)Tc-MIBI and its correlation with messenger RNA (mRNA) levels of MDR1, multidrug-resistance associated protein-1 (MRP1) and lung resistance protein (LRP) in acute leukaemia.

METHODS

A total of 26 patients (age range 17-72 years; mean age 51.88+/-2.52 years) with newly diagnosed acute leukaemia were included in the study. The expression of MDR1, MRP1 and LRP on mRNA levels were assessed by quantitative RT-PCR in the blast cells. The MIBI uptake in the bone marrow was evaluated using a quantitative scoring system with determination of the tumour-to-background ratios for the bone marrow areas. The correlation between the quantitative RT-PCR results and MIBI uptake was analysed by using Spearman's rank correlation coefficients with two-tailed test of significance.

RESULTS

There was an inverse relationship between (99m)Tc-MIBI uptake of bone marrow and both mRNA levels of MDR1 and MRP1 (P=0.000, r= -0.733 and P=0.001, r= -0.610, respectively). No correlation was found between MIBI uptake and mRNA levels of LRP.

CONCLUSION

Increased expression of MDR1 and MRP1 correlates with a low accumulation of (99m)Tc-MIBI in bone marrow areas in patients with acute leukaemia. (99m)Tc-MIBI bone marrow scintigraphy can identify the MDR1 and MRP1 phenotype, but not LRP, in patients with acute leukaemia.

Guidelines for the use of imaging in the management of myeloma

In 2001, reference to the use of imaging in the British Committee for Standards in Haematology guidelines for the diagnosis and management of myeloma was confined to the standard use of plain X-rays in the diagnostic skeletal survey and emergency use of computed tomography (CT) and magnetic resonance (MR) imaging in the setting of cord compression. Since then, there has been a steady rise in interest in the use of various imaging techniques in the management of myeloma. The purpose of imaging in the management of myeloma includes the assessment of the extent and severity of the disease at presentation, the identification and characterisation of complications, and the assessment of response to therapy. Plain radiography, CT, and MR imaging are generally established examination techniques in myeloma whilst positron emission tomography (PET) and (99)Technetium sestamibi (MIBI) imaging are promising newer scanning techniques under current evaluation. These stand-alone imaging guidelines discuss recommendations for the use of each modality of imaging at diagnosis and in the follow up of patients with myeloma.