Elena Zamagni, Cristina Nanni, Luca Dozza, Thomas Carlier, Clément Bailly, Paola Tacchetti, Annibale Versari, Stephane Chauvie, Andrea Gallamini, Barbara Gamberi, Denis Caillot, Francesca Patriarca, Margaret Macro, Mario Boccadoro, Laurent Garderet, Simona Barbato, Stefano Fanti, Aurore Perrot, Francesca Gay, Peter Sonneveld, Lionel Karlin, Michele Cavo, Caroline Bodet-Milin, Philippe Moreau, Françoise Kraeber-Bodéré, Zamagni E., Nanni C., Dozza L., Carlier T., Bailly C., Tacchetti P., Versari A., Chauvie S., Gallamini A., Gamberi B., Caillot D., Patriarca F., Macro M., Boccadoro M., Garderet L., Barbato S., Fanti S., Perrot A., Gay F., Sonneveld P., Karlin L., Cavo M., Bodet-Milin C., Moreau P., Kraeber-Bodere F., Bernardo, Elizabeth, The Institute of Hematology and Oncology L. and A. Seràgnoli [Bologna, Italy], Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Policlinico S. Orsola-malpighi, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Servizio sanitario regionale Emilia-Romagna, Nuclear Oncology (CRCINA-ÉQUIPE 13), Centre de Recherche en Cancérologie et Immunologie Nantes-Angers (CRCINA), Université d'Angers (UA)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Université d'Angers (UA)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre hospitalier universitaire de Nantes (CHU Nantes), Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia (UNIMORE), Santa Croce e Carle Hospital [Cuneo, Italy], Centre de Lutte contre le Cancer Antoine Lacassagne [Nice] (UNICANCER/CAL), UNICANCER-Université Côte d'Azur (UCA), Service d'Hématologie Clinique (CHU de Dijon), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Università degli Studi di Udine - University of Udine [Italie], Laboratoire d'Hématologie Biologique [CHU Caen], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Tumorothèque de Caen Basse-Normandie (TCBN), Università degli studi di Torino = University of Turin (UNITO), Service d'Hématologie clinique [CHU Pitié-Salpêtrière], CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Université d'Angers (UA)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre hospitalier universitaire de Nantes (CHU Nantes), Erasmus University Medical Center [Rotterdam] (Erasmus MC), Service d’Hématologie [Centre Hospitalier Lyon Sud - HCL], Centre Hospitalier Lyon Sud [CHU - HCL] (CHLS), Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Service d'Hématologie [Nantes], Centre hospitalier universitaire de Nantes (CHU Nantes), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA), Università degli Studi di Modena e Reggio Emilia, Università degli studi di Torino (UNITO), and Hematology
PURPOSE 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is currently the standard technique to define minimal residual disease (MRD) status outside the bone marrow (BM) in patients with multiple myeloma (MM). This study aimed to define criteria for PET complete metabolic response after therapy, jointly analyzing a subgroup of newly diagnosed transplantation-eligible patients with MM enrolled in two independent European randomized phase III trials (IFM/DFCI2009 and EMN02/HO95). PATIENTS AND METHODS Two hundred twenty-eight patients were observed for a median of 62.9 months. By study design, PET/CT scans were performed at baseline and before starting maintenance (premaintenance [PM]). The five-point Deauville scale (DS) was applied to describe BM (BM score [BMS]) and focal lesion (FL; FL score [FS]) uptake and tested a posteriori in uni- and multivariable analyses for their impact on clinical outcomes. RESULTS At baseline, 78% of patients had FLs (11% extramedullary), 80% with an FS ≥ 4. All patients had BM diffuse uptake (35.5% with BMS ≥ 4). At PM, 31% of patients had visually detectable FLs (2% extramedullary), 24% and 67.7% of them with an FS of 3 and ≥ 4, respectively. At PM, 98% of patients retained residual BM diffuse uptake, which was significantly lower than at baseline (mainly between BMS 2 and 3, BMS was ≥ 4 in only 8.7% of patients). By both uni- and multivariable analysis, FS and BMS < 4 were associated with prolonged progression-free survival (PFS) and overall survival (OS) at PM (OS: hazard ratio [HR], 0.6 and 0.47, respectively; PFS: HR, 0.36 and 0.24, respectively) CONCLUSION FL and BM FDG uptake lower than the liver background after therapy was an independent predictor for improved PFS and OS and can be proposed as the standardized criterion of PET complete metabolic response, confirming the value of the DS for patients with MM.