Maryam Aghighi MD, Presenter: Nothing to Disclose

Christopher Klenk MD, Abstract Co-Author: Nothing to Disclose

saeid zanganeh PhD, Abstract Co-Author: Nothing to Disclose

Tarsheen Sethi MBBS, Abstract Co-Author: Nothing to Disclose

sandra luna-fineman MD, Abstract Co-Author: Nothing to Disclose

Heike E. Daldrup-Link MD, Abstract Co-Author: Nothing to Disclose

18F-FDG PET/MR is a new technology which can provide “one-stop-shop” staging of pediatric patients. However, in order to enable staging of primary tumors and metastases in one session, imaging protocols need to be streamlined. Our aim was to compare an accelerated whole body PET/MRI protocol based on co-registration of ferumoxytol-enhanced end-expiration breath hold T1-weighted SPGR scans with 18F-FDG PET images with standard 18F-FDG-PET/STIR exams.

31 children with malignant lymphoma and sarcoma underwent a routine 18F-FDG PET staging exam, followed by a ferumoxytol-enhanced whole body MR scan, using STIR and T1-weighted breath-hold SPGR sequences. 18F-FDG-PET scans were fused with STIR and SPGR sequences. The presence or absence of tumors in different anatomical areas was determined separately for 18F-FDG-PET/STIR and 18F-FDG-PET/SPGR staging exams by 2 experienced reviewers. Histopathology and follow-up imaging served as the standard of reference. Tumor staging results were compared between the two imaging modalities using the Mc Nemar’s test. In addition, tumor stage according to the Ann Arbor Classification for lymphoma and TNM Classification for Soft Tissue Sarcoma was assessed using un-weighted Cohen’s Kappa statistics and Kendall’s tau-a coefficient. Histopathology and follow-up imaging served as the standard of reference.

Results18F-FDG-PET/SPGR detected 229 of 246 malignant lesions at 2077 anatomical regions and 18F-FDG-PET/STIR detected 236 of 246 malignant lesions. Comparing18F-FDG-PET/STIR to 18F-FDG-PET/SPGR, sensitivities were 94.3% versus 91.78% specificities 93.63% versus 92.18%, and diagnostic accuracies 93.95% versus 91.93%. Whole body data acquisition time was 20 minutes for18F-FDG-PET/SPGR and 60 minutes for18F-FDG-PET/STIR sequences.

18F-FDG-PET/STIR and 18F-FDG-PET/SPGR demonstrated no significant differences insensitivity, specificity or diagnostic accuracy for staging of pediatric lymphomas and sarcomas. 18F-FDG-PET/SPGR data could be acquired with markedly accelerated acquisition time compared to18F-FDG-PET/STIR sequences.

Our study shows that 18F-FDG-PET/SPGR is comparable to18F-FDG-PET/STIR with significant reduction in scan time making it more patient-friendly. This is clinically applicable to the new PET/MRI technique for staging of cancer.

Aghighi, M, Klenk, C, zanganeh, s, Sethi, T, luna-fineman, s, Daldrup-Link, H, Accelerated PET/MR Staging of Children with Cancer.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016977.html