Association of 99mTc-MIBI brain SPECT and proton magnetic resonance spectroscopy (1H-MRS) to assess glioma recurrence after radiotherapy.
OBJECTIVE
The aim of this study was to compare 99mTc-MIBI brain SPECT and proton magnetic resonance spectroscopy (1H-MRS) findings and to evaluate their association.


METHODS
Both exams were performed on 30 glioma patients, previously operated and treated with radiotherapy, having MRI doubtful between recurrence and radiotherapy effects. SPECT images were acquired 15 minutes after radiopharmaceutical administration with a dual-head gamma camera. T1/B1 uptake ratio was calculated between a tumor ROI (T1) and a normal mirror symmetric ROI (B1) and T2/B2 ratio was obtained between a ROI in the hottest neoplastic part (T2) and a normal mirror symmetric ROI (B2). 1H-MRS was performed using a 1.5 T system equipped with a spectroscopy package. SPECT and 1H-MRS data were compared with histology after new surgery or with follow-up.


RESULTS
SPECT and 1H-MRS showed recurrence in 18 patients (confirmed by biopsy, coinciding only in 17 cases) and were negative in 10 (1 false negative). SPECT and 1H-MRS disagreed in 2 cases of recurrence (1 diagnosed by brain SPECT, 1 by 1H-MRS). T1/B1 ratio mean value (4.26+/-2.5) was significantly lower than T2/B2 (4.93+/-2.81; P<0.001). SPECT and 1H-MRS sensitivity in detecting recurrence was 90%, specificity 100%, accuracy 93%, negative predictive value (NPV) 83% and positive predictive value (PPV) 100%; the associated exams sensitivity was 95%, specificity 100%, accuracy 96.6%, NPV 90.9%, PPV 100%.


CONCLUSIONS
Brain SPECT and 1H-MRS have equivalent values of diagnostic parameters in differentiating tumor recurrence and radiation effects, and their association might provide additional information.
Nuclear Medicine Section, Department of Radiological Sciences, University of Perugia, Perugia, Italy. mednuc@unipg.it
B
B
Palumbo
M
M
Lupattelli
G P
GP
Pelliccioli
P
P
Chiarini
T O
TO
Moschini
I
I
Palumbo
Donatella
D
Siepi
P
P
Buoncristiani
M
M
Nardi
P
P
Giovenali
R
R
Palumbo
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy*; D005260:Female; D005910:Glioma / Q000378:metabolism* / Q000532:radiotherapy*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000517:prevention & control; D011379:Prognosis; D011522:Protons; D019275:Radiopharmaceuticals; D013223:Statistics as Topic; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome
D011522:Protons; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi