Treatment response evaluation with super(18)F-FDG PET/CT and super(18)F-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 2017-01, 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
• 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 super(18)F-FDG and super(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). 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 super(18)F-FDG and super(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). 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, super(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, super(18)F-FDG PET/CT-based treatment response revealed CR in 14 patients ( super(18)F-FDG PET/CT CR), PR in 11 patients ( super(18)F-FDG PET/CT PR) and progressive disease in four patients ( super(18)F-FDG PET/CT PD). In terms of super(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, super(18)F-NaF PET/CT depicted 56 of the 129 super(18)F-FDG positive lesions (43 %). Follow-up super(18)F-NaF PET/CT showed persistence of 81.5 % of the baseline super(18)F-NaF positive MM lesions after treatment, despite the fact that 64.7 % of them had turned to super(18)F-FDG negative. Treatment response according to super(18)F-NaF PET/CT revealed CR in one patient ( super(18)F-NaF PET/CT CR), PR in five patients ( super(18)F-NaF PET/CT PR), SD in 12 patients ( super(18)F-NaF PET/CT SD), and PD in seven patients ( super(18)F-NaF PET/CT PD). Dynamic super(18)F-FDG and super(18)F-NaF PET/CT studies showed that SUV sub(average), SUV sub(max), as w