A Comparison between FDG PET/CT, CT and MRI in Detection of Spinal Metastases and its Impact on Clinical Management

Document Type : Original Paper, Oncology

Author

National Cancer Institute , Cairo University

Abstract

The aim of this study was to compare the
diagnostic value of combined F-18-FDG
PET/CT, CT and MRI indetection of spinal
metastatic lesionsand their impact on
management of these patients. Patients
and methods: A total of 22 patients with
biopsy-proven malignancy were enrolled.
All patients underwent spinal MRI and
whole body F-18-FDG PET/CT
examinations using standard techniques.
The diagnostic capabilities of the imaging
modalities were compared in the same
spinal field of view. F-18-FDG PET/CT
and MRI findings were compared with the
results of biopsy or clinical / radiological
follow up for at least 12 months as the
reference standards. Results: A total of
214 vertebral lesions were detected in 22
cancer patients based on combined clinical
and radiological follow up (FU), these
lesions were divided into: 129 metastatic &
85 benign lesions. Moreover these 22
patients were divided into: 12 with spinal
metastases and 10 free from spinal
metastases. Both lesions & patients based
data analysis showed a significant higher
diagnostic accuracy for the combined F-18-
FDG PET/CT (98.5% and 94.5%)
compared to MRI (86% and 68%) and CT
(79.5% & 54.5%) respectively
(P<0.05).The significant difference
between F-18 FDG PET/CT and
morphological techniques were more
obvious on specificity indices rather than
sensitivity indices in both lesion and patient
based analysis. On the other hand, MRI
results were superior to those of CT on both
lesions and patients data analysis. On
lesion-based analysis, the sensitivity,
specificity, positive predictive value (PPV)
and negative predictive value (NPV) for F-
18 FDG PET/CT were 99%, 98%, 98% &
99%, For MRI were 88.4%, 82.4%,88.4%
and 82.3%, and for CT were 83.7%, 73%,
82.4 and 74.5% respectively. On patientbased analysis the sensitivity and
specificity for F-18 FDG PET/CT were
100% & 90% compared to 75% &60% in
MRI and 66.6% &40% in CT (P<0.05).
The relative superiority of the F-18 FDG
based technique compared to the
morphological techniques in respect to
sensitivity and specificity provide
significant changes in patient management
in 27.2 % & 41% of cases compared to MRI
& CT respectively.
Conclusion: Combined F-18 FDG
PET/CT scan showed the highest utmost
sensitivity, specificity and accuracy
followed by MRI and lastly CT in the 
detection of spinal metastatic lesions.
Consequently18F-FDG PET/CT has a
better impact on clinical management
compared to MRI&CT


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