HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Zhang, J. Articles by Knopp, M. PubMed Articles by Zhang, J. Articles by Knopp, M.

Does this happen commonly or rarely? Influence of standardized uptake value readouts on therapy monitoring in FDG PET/CT

¹ Radiology, The Ohio State University Medical Center, Columbus, Ohio

1165

Objectives: To identify and evaluate the influence of Standardized Uptake Value (SUV) readouts on monitoring tumor response to therapy in FDG PET/CT.

Methods: PET/CT data in 10 patients with thin-sliced CT (1.5mm) on a Siemens HI-REZ and 10 patients with thick-sliced CT (4.25mm) on a GE Discovery ST (Arm-A) as well as 87 tumor data before and after therapy with 1.5mm CT on the HI-REZ (Arm-B) were selected from routine clinical scans. Scans were performed 75±10 minutes after injecting [450-600]MBq of F18 FDG and reconstructed using 2D OSEM with an iteration step of 2. Maximum SUV of each lesion was measured twice under both PET/CT fusion and PET alone using Syngo e.soft 5.5. The SUV-based therapy response assessment was quantitatively interpreted using a 5-level criteria (<-20%, [-20,-10]%, [-10, 10]%, [10-20]%, >20%).

Results: In Arm-A, SUV readout from PET/CT fusion significantly differed from PET alone (p<0.03), leading to a 1-15% variance for PET with 1.5mm CT and 6-36% for PET with 4.25mm CT. The difference can also be found in Arm-B (p<0.001 & 0-12%). The SUV response after therapy from both fusion and PET alone shows significantly different results (p=0.02) and leads to 5-level score discrepancies of 16% for overall lesions, increasing to 22% when comparing follow-ups from fusion with baselines from PET.

Conclusions: SUV calculations based on PET/CT fusion may differ from PET alone between products since some products use interpolated PET data when displaying PET/CT fusion rather than PET only. Due to the different matrix sizes of PET and CT, this can result in significant differences of therapy response assessment. To ensure consistency, the same calculation method and image resolution as well as reconstruction should be consistently used to avoid this variance.

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Zhang, J. Articles by Knopp, M. PubMed Articles by Zhang, J. Articles by Knopp, M.