Treatment response evaluation with 18F-FDG PET/CT and 18F-NaF PET/CT in multiple myeloma patients undergoing high-dose chemotherapy and autologous stem cell transplantation

• Published in: European journal of nuclear medicine and molecular imaging 2017, Vol.44 (1), p.50-62
• Main Authors: Sachpekidis, Christos, Hillengass, J., Goldschmidt, H., Wagner, B., Haberkorn, U., Kopka, K., Dimitrakopoulou-Strauss, A.
• Format: Article
• Language: English
• Subjects: Cardiology; Imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Oncology; Original Article; Orthopedics; Radiology
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-016-3502-6

Aim The aim of this study was to assess the combined use of the radiotracers 18 F-FDG and 18 F-NaF in treatment response evaluation of a group of multiple myeloma (MM) patients undergoing high-dose chemotherapy (HDT) followed by autologous stem cell transplantation (ASCT) by means of static (whole-body) and dynamic PET/CT (dPET/CT). Patients and methods Thirty-four patients with primary, previously untreated MM scheduled for treatment with HDT followed by ASCT were enrolled in the study. All patients underwent PET/CT scanning with 18 F-FDG and 18 F-NaF before and after therapy. Treatment response by means of PET/CT was assessed according to the European Organization for Research and Treatment of Cancer (EORTC) 1999 criteria. The evaluation of dPET/CT studies was based on qualitative evaluation, semi-quantitative (SUV) calculation, and quantitative analysis based on two-tissue compartment modelling and a non-compartmental approach leading to the extraction of fractal dimension (FD). Results An analysis was possible in 29 patients: three with clinical complete response (CR) and 26 with non-CR (13 patients near complete response-nCR, four patients very good partial response-VGPR, nine patients partial response-PR). After treatment, 18 F-FDG PET/CT was negative in 14/29 patients and positive in 15/29 patients, showing a sensitivity of 57.5 % and a specificity of 100 %. According to the EORTC 1999 criteria, 18 F-FDG PET/CT-based treatment response revealed CR in 14 patients ( 18 F-FDG PET/CT CR), PR in 11 patients ( 18 F-FDG PET/CT PR) and progressive disease in four patients ( 18 F-FDG PET/CT PD). In terms of 18 F-NaF PET/CT, 4/29 patients (13.8 %) had a negative baseline scan, thus failed to depict MM. Regarding the patients for which a direct lesion-to-lesion comparison was feasible, 18 F-NaF PET/CT depicted 56 of the 129 18 F-FDG positive lesions (43 %). Follow-up 18 F-NaF PET/CT showed persistence of 81.5 % of the baseline 18 F-NaF positive MM lesions after treatment, despite the fact that 64.7 % of them had turned to 18 F-FDG negative. Treatment response according to 18 F-NaF PET/CT revealed CR in one patient ( 18 F-NaF PET/CT CR), PR in five patients ( 18 F-NaF PET/CT PR), SD in 12 patients ( 18 F-NaF PET/CT SD), and PD in seven patients ( 18 F-NaF PET/CT PD). Dynamic 18 F-FDG and 18 F-NaF PET/CT studies showed that SUV average , SUV max , as well as the kinetic parameters K 1 , influx and FD from reference bone marrow and skeleton responded to therapy w