Examining MRI and PET/CT for Detecting Bone Lesions and Predicting Survival in Patients With Myeloma

Skeletal survey is a standard procedure for the diagnosis of lytic disease in patients with myeloma, but it is unknown whether magnetic resonance imaging (MRI) and positron emission tomography (PET)/CT using [18F]fluorodeoxyglucose (FDG) could be useful options to detect bone lesions and bone involvement at diagnosis.

In a prospective analysis of the IFM/DFCI (Intergroupe Francophone du Myélome/Dana-Farber Cancer Institute) 2009 trial, Philippe Moreau, MD, head of the Hematology Department at the University Hospital Hôtel-Dieu in Nantes, France, and co-authors compared the diagnostic performance of MRI and FDG PET/CT in patients with myeloma, finding no difference in their ability to detect bone lesions.

“[The study] clearly shows the high detection rates of both methods,” the authors wrote of the findings, adding that “PET-CT is a powerful tool to evaluate the prognosis of de novo myeloma.” The results were published in the Journal of Clinical Oncology.

The analysis included 134 patients (median age = 59 years; range = 37-65 years) enrolled from 18 centers who underwent MRI or PET/CT at myeloma diagnosis, after three cycles of treatment (lenalidomide, bortezomib, and dexamethasone [RVD]), and before maintenance therapy. Seventy-one patients received three cycles of RVD (arm A) and 63 received RVD plus autologous hematopoietic cell transplantation (arm B).

At diagnosis, bone lesions were positively detected (primary endpoint) in 127 of 134 patients who received MRI (95%), compared with 122 of 134 patients who received PET/CT (91%; p=0.33).

The rates of normalization of MRI were 3 percent after three cycles of RVD and 11 percent prior to maintenance therapy; normalization of MRI was not predictive of either progression-free survival (PFS; p=0.42) or overall survival (OS; p=0.67).

PET/CT scans became normal after three cycles of RVD in 32 percent of patients with a positive evaluation at baseline, and PFS was improved in those patients (30-month PFS = 78.7% vs. 56.8%; p=0.08), but OS was not affected (p=0.16).

Normalization of a PET/CT scan before maintenance therapy was associated with higher rates of two-year OS compared with patients who did not have a normal PET/CT scan before maintenance: 94.2 percent versus 72.9 percent (p value not reported). The authors noted that normalization at that time point was significantly prognostic of PFS (p=0.004) and OS (p<0.001) in patients in arm B but not arm A.

Comparatively, “[there was a] lack of effectiveness of MRI during follow-up to assess prognosis,” the authors wrote. “Of note, we did not use entire-body MRI or diffusion-weighted imaging MRI, which may increase sensitivity, but nevertheless, our positivity rate of 95 percent demonstrates the value of performing MRI of the spine and pelvis in patients with symptomatic myeloma at diagnosis,” the authors noted.

The study is limited by its lack of standardization.

The authors reported financial support from Celgene, Takeda, Novartis, Janssen-Cilag, Amgen, and Sanofi.

Source: Moreau P, Attal M, Caillot D, et al. Prospective evaluation of magnetic resonance imaging and [18F]fluorodeoxyglucose positron emission tomography–computed tomography at diagnosis and before maintenance therapy in symptomatic patients with multiple myeloma included in the IFM/DFCI 2009 trial: results of the IMAJEM study. J Clin Oncol. 2017;35:2911-8.