RESUMEN
The interest of 18Fluoro-deoxyglucose (FDG) positron emission tomography (PET) imaging in the management of patients with multiple myeloma (MM) for the workup at diagnosis and for therapeutic evaluation has recently been demonstrated. FDG-PET is a powerful imaging tool for bone lesions detection at initial diagnosis with high sensitivity and specificity values. The independent pejorative prognostic value on progression-free survival (PFS) and overall survival (OS) of baseline PET-derived parameters (presence of extra-medullary disease (EMD), number of focal bone lesions (FLs), and maximum standardized uptake values [SUVmax]) has been reported in several large independent prospective studies. During therapeutic evaluation, FDG-PET is considered as the reference imaging technique, because it can be performed much earlier than MRI which lacks specificity. Persistence of significant FDG uptake after treatment, notably before maintenance therapy, is an independent pejorative prognostic factor, especially for patients with a complete biological response. So FDG-PET and medullary flow cytometry are complementary tools for detection of minimal residual disease before maintenance therapy. However, the definition of PET metabolic complete response should be standardized. In patients with smoldering multiple myeloma, the presence of at least one hyper-metabolic lytic lesions on FDG-PET may be considered as a criterion for initiating therapy. FDG-PET is also indicated for initial staging of a solitary plasmacytoma so as to not disregard other bone or extra-medullary localizations. Development of nuclear medicine offer new perspectives for MM imaging. Recent PET tracers are willing to overcome limitations of FDG. (11)C-Methionine, which uptake reflects the increased protein synthesis of malignant cells seems to correlate well with bone marrow infiltration. Lipid tracers, such as Choline or acetate, and some peptide tracers, such as (68) Ga-Pentixafor, that targets CXCR4 (chemokine receptor-4, which is often expressed with high density by myeloma cells), are other promising PET ligands. 18F-fludarabine and immuno-PET targeting CD138 and CD38 also showed promising results in preclinical models.
RESUMEN
BACKGROUND: Venous thromboembolism (VTE) is a major complication of myeloma therapy recently observed with the increasing use of up-front thalidomide and dexamethasone (thal-dex). The pathogenesis of thal-induced VTE is not well recognized, and the role of prothrombotic factors, especially of thrombophilic abnormalities, is not yet determined. MATERIAL AND METHODS: Two hundred and sixty-six patients with newly diagnosed multiple myeloma (MM) were primarily treated with thal-dex in preparation for subsequent high-dose therapy and autologous stem-cell transplantation. Out of these 266 patients, 190 were evaluated for thrombophilic alterations at baseline, and 125 of them were also re-assessed after thal-dex therapy. RESULTS: The presence of genetic thrombophilic polymorphisms among patients with MM was superimposable to that of normal controls and was associated with a twofold increase in the relative risk of VTE. aAPCR and elevated factor VIII levels were frequent, albeit transient, alterations and were not associated with a significant increase in the risk of VTE. Two hundred and forty-six patients received a thromboprophylaxis with fixed low-dose warfarin (1.25 mg/day) during thal-dex therapy. Of these patients (or 10.6%), 26 had symptomatic VTE events. Their patients-years rate of VTE (35.5%) was significantly lower in comparison with the 86.2% rate recorded among the first 19 patients who initially entered the study and did not receive any kind of thromboprophylaxis (P = 0.043). CONCLUSIONS: On the basis of these data, a baseline thrombophilic work up is not recommended in patients with receiving up-front thal-dex. For these patients, fixed low-dose warfarin may be a valuable prophylaxis against VTE.