ABSTRACT
The iliac crest is the sampling site for minimal residual disease (MRD) monitoring in multiple myeloma (MM). However, the disease distribution is often heterogeneous, and imaging can be used to complement MRD detection at a single site. We have investigated patients in complete remission (CR) during first-line or salvage therapy for whom MRD flow cytometry and the two imaging modalities positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging (DW-MRI) were performed at the onset of CR. Residual focal lesions (FLs), detectable in 24% of first-line patients, were associated with short progression-free survival (PFS), with DW-MRI detecting disease in more patients. In some patients, FLs were only PET positive, indicating that the two approaches are complementary. Combining MRD and imaging improved prediction of outcome, with double-negative and double-positive features defining groups with excellent and dismal PFS, respectively. FLs were a rare event (12%) in first-line MRD-negative CR patients. In contrast, patients achieving an MRD-negative CR during salvage therapy frequently had FLs (50%). Multi-region sequencing and imaging in an MRD-negative patient showed persistence of spatially separated clones. In conclusion, we show that DW-MRI is a promising tool for monitoring residual disease that complements PET and should be combined with MRD.
Subject(s)
Diffusion Magnetic Resonance Imaging/methods , Flow Cytometry/methods , Hematopoietic Stem Cell Transplantation/adverse effects , Multiple Myeloma/therapy , Neoplasm, Residual/diagnosis , Positron-Emission Tomography/methods , Biomarkers, Tumor/genetics , Follow-Up Studies , Humans , Multiple Myeloma/pathology , Neoplasm, Residual/diagnostic imaging , Neoplasm, Residual/etiology , Prognosis , Remission Induction , Survival Rate , Transplantation, Autologous , Exome SequencingABSTRACT
Magnetic resonance angiography (MRA) and venography (MRV) are useful tools in the diagnosis and analysis of both intracranial and head and neck tumors. These procedures illuminate the three-dimensional relationships of the tumors and the adjacent cerebral vasculature. Contrast administration allows further analysis of these lesions. Research continues to improve the spatial resolution that may preclude conventional angiography. For the first time, MRA allows non-invasive diagnosis of neurovascular conditions such as trigeminal neuralgia and pulsatile tinnitus. This accurate diagnosis revolutionizes therapy. Although MRA has certain limitations, its role continues to expand. The value of MRA for diagnosis and treatment planning is paramount.
