Johannes Grueneisen, Presenter: Nothing to Disclose

Benedikt Michael Schaarschmidt MD, Abstract Co-Author: Nothing to Disclose

Karsten J. Beiderwellen MD, Abstract Co-Author: Nothing to Disclose

Martin Heubner, Abstract Co-Author: Nothing to Disclose

Michael Forsting MD, Abstract Co-Author: Nothing to Disclose

Thomas C. Lauenstein MD, Abstract Co-Author: Nothing to Disclose

Lale Umutlu MD, Abstract Co-Author: Consultant, Bayer AG

To evaluate the diagnostic benefit of diffusion-weighted imaging (DWI) in a simultaneous 18F-FDG PET/MRI protocol for whole-body staging of patients with primary or recurrent malignancies of the female pelvis.

67 patients with primary or a suspected recurrence of a pelvic malignancy were included in our study. All patients underwent whole-body 18F-FDG PET/MRI (Biograph mMR, Siemens) including DWI. Two radiologists separately evaluated the 18F-FDG PET/MRI datasets without DWI followed by a second reading including DWI. After assessment of (1) overall lesion detection, all lesions considered as malignant were evaluated concerning (2) lesion conspicuity (4-point ordinal scale) and (3) diagnostic confidence (3-point ordinal scale). In a second session, the lesion-to-background contrast and diagnostic confidence for PET and DWI was assessed qualitatively. Wilcoxon signed-rank test was applied to assess statistical significance.

A total of 136 primary and recurrent tumor lesions were detected in 58 of the 67 patients. 18F-FDG PET/MRI including DWI revealed an insignificantly minimal higher lesion conspicuity (PET/MRI + DWI: 3,85 ± 0,38; PET/MRI - DWI: 3,88 ± 0,37) and diagnostic confidence (PET/MRI: 2,71 ± 0,57 DWI: 2,77 ± 0,50) in comparison to PET/MRI without DWI. Furthermore, the lesion-to-background contrast revealed significantly higher values for PET (3,82 ± 0,43) in comparison to DWI (3,57 ± 0,80) with a significantly higher diagnostic confidence (PET: 2,70 ± 0,58; DWI: 2,51 ± 0,68) for malignancy (p < 0,01).

DWI in PET / MRI does not provide a diagnostic benefit for whole-body staging of female patients with pelvic malignancies. Regarding the advantages of PET in comparison to DWI in the delineation and characterization of tumor lesions, DWI should be questioned as an integral part of PET / MRI protocols for whole-body tumor staging.

The omission of DWI in whole-body tumor staging of pelvic malignancies may lead to a significant reduction of examination times, thus increasing patient comfort without a relevant decrease in diagnostic competence.

Grueneisen, J, Schaarschmidt, B, Beiderwellen, K, Heubner, M, Forsting, M, Lauenstein, T, Umutlu, L, Diagnostic Value of Diffusion-weighted Imaging in a Simultaneous 18F-FDG PET/MRI Protocol for Whole-body Staging of Female Patients with Pelvic Malignancies.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014557.html