Dramatically improved survival in multiple myeloma patients in the recent decade: results from a Swedish population-based study. Thorsteinsdottir S, Dickman PW, Landgren O, Blimark C, Hultcrantz M, Turesson I, et al. In summary, PET after ASCT detected residual disease in a substantial proportion of patients in VGPR or better, even in patients who were MRD negative, and KRd consolidation treatment changed PET status in 33% of patients. MRD-negative patients were more likely to convert than MRD-positive patients. KRd consolidation converted 33% of PET-positive patients into PET negativity.

A total of 53 patients (33%) were PET positive and 57% of PET-positive patients were MRD negative, demonstrating that these response assessments are complementary. Overall, 159 patients were screened with PET. Flow cytometry-based minimal residual disease (MRD) analysis was performed before and after treatment for correlation with PET. PET-positive patients received four 28-day cycles of carfilzomib-lenalidomide-dexamethasone (KRd). In this phase II study, we screened first-line patients with very good partial response (VGPR) or better after ASCT with PET.

Hence, giving PET-positive patients additional treatment may improve their outcome. However, PET-positive patients who achieve PET negativity after treatment seem to have comparable outcomes to patients who were PET negative at diagnosis. 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET) positivity after first-line treatment with autologous stem cell transplantation (ASCT) in multiple myeloma is strongly correlated with reduced progression-free and overall survival.

Myeloma stem cell transplant