Multiple myeloma: current therapy and a glimpse of the future

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.

Maintenance treatment of multiple myeloma

In multiple myeloma (MM), low-cost maintenance treatment has some attractions, since maintenance of a small tumor is usually compatible with a fairly healthy state. However, the great majority of the studies of maintenance treatment have failed to show any clinical benefit. Based on simple theoretical consideration, it is shown that in MM response duration and survival are affected primarily by the residual tumor mass after primary treatment, and by the kinetics of the tumor. Continuation of maintenance treatment is likely to have a moderate effect. The main cause of that is identified in the presence or in the development of a substantial proportion of drug-resistant cells. Preliminary data suggest that only alpha-interferon can be useful for maintenance, and that it can act by slowing down the kinetics of the tumor.

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.

Renal transplantation in multiple myeloma. Case report and review of the literature

A patient with end-stage renal disease and known benign monoclonal gammopathy underwent kidney transplantation at Westchester County Medical Center, Valhalla, NY. After surgery, during routine follow-up, the patient had laboratory evidence of frank multiple myeloma. However, she did not show any clinical signs or symptoms of the disease. Four years later, the patient is asymptomatic and continues to have stable renal function. As a result of our experience, and that of others, we support transplantation as a viable option for patients with multiple myeloma.

Pharmacokinetics of oral melphalan in relation to renal function in multiple myeloma patients

The impact of renal function on oral melphalan pharmacokinetics was studied in 15 patients with multiple myeloma. A two-fold interindividual variation in the plasma concentration-time curve (AUC) was found. An increase in AUC and melphalan mean residence time (MRT) was noted in patients with renal dysfunction. No correlation was found between GFR and the terminal plasma half-life time. We conclude from these results that renal dysfunction is associated with an increase in AUC and MRT of oral melphalan. A careful follow-up of hematological toxicity and possibly a dose reduction of melphalan are proposed for myeloma patients with renal impairment.

The pharmacokinetics of melphalan during intermittent therapy of multiple myeloma

During intermittent melphalan-prednisone therapy the area under the plasma concentration-time curve of melphalan increased by an average of 45% after oral or intravenous administration of the drug in myeloma patients during the initial three courses at six-week intervals. The rise in melphalan plasma concentrations could not be referred to an alteration in melphalan elimination, metabolism, erythrocyte/plasma partition ratio, or protein binding. A possible explanation could be that covalent binding sites of melphalan were successively saturated during intermittent treatment, resulting in higher drug concentrations during successive courses of therapy.