A prospective study comparing whole-body FDG PET/CT to combined planar bone scan with 67Ga SPECT/CT in the Diagnosis of Spondylodiskitis.
OBJECTIVE
This study aimed to prospectively evaluate the usefulness of PET/CT using F-FDG in comparison to bone scan and Ga in the diagnosis of spondylodiskitis.


METHODS
This prospective study included 34 patients (15 women and 19 men) aged 59 (18) years with clinical symptoms of spondylodiskitis. Whole-body PET/CT and bone scan combined with planar and SPECT/CT Ga was performed in all patients. Diagnosis of spondylodiskitis was made by microbiology and/or on the basis of clinical and laboratory findings and imaging follow-up.


RESULTS
Spondylodiskitis was confirmed in 18 of 34 patients. In the other 16 patients, spondylodiskitis was finally excluded, and the most frequent findings observed were degenerative spondyloarthropathy (n = 7), vertebral fracture (n = 3), endocarditis (n = 2), and other processes (n = 4). The sensitivity and specificity of combined bone scan and Ga were 78% and 81%, with a positive predictive value of 82%, a negative predictive value of 76%, and an overall accuracy of 79%. SPECT/CT with Ga helped identify soft tissue involvement in 10 of 18 patients. The sensitivity and specificity of PET/CT were 89% and 88%, with a positive predictive value of 89%, a negative predictive value of 87%, and an overall accuracy of 88%. Concordance between Ga and PET/CT was good (κ = 0.71; 95% confidence interval, 0.48-0.94). PET/CT was able to detect soft tissue involvement in 12 of 18 patients. In 2 patients, a multifocality was found, which was only diagnosed by PET/CT.


CONCLUSIONS
PET/CT is useful in the diagnosis of spondylodiskitis, with more accurate results than combined bone scan and Ga. SPECT/CT with Ga is recommended, especially when planar bone scan and Ga pattern is suggestive of spondylodiskitis.
Nuclear Medicine Department, Hospital Clìnic, Villarroel, 170, 08036 Barcelona, Spain. dfuster@clinic.ub.es
David
D
Fuster
Oriol
O
Solà
Alex
A
Soriano
Anna
A
Monegal
Xavier
X
Setoain
Xavier
X
Tomás
Sebastià
S
Garcia
Josep
J
Mensa
Domenico
D
Rubello
Francesca
F
Pons
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D015299:Discitis / Q000000981:diagnostic imaging* / Q000382:microbiology; D005260:Female; D019788:Fluorodeoxyglucose F18; D005710:Gallium Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging / Q000379:methods*; D055815:Young Adult
D005710:Gallium Radioisotopes; D019788:Fluorodeoxyglucose F18