SPECT and PET Imaging of Meningiomas

Table 1

SPECT and PET radiopharmaceuticals used in meningiomas.

Tracer	Imaging modality	Advantages	Disadvantages	References
Thallium-201	SPECT, analog of K^+	Information of tumor biological characteristics	Limited imaging properties, serial brain SPECT studies	[15–18]
^99mTc-labeled compounds	SPECT, tissue perfusion, cell membrane integrity, and mitochondrial activity	Viability marker, prediction of anticancer drug resistance related to Pgp	Small series of patients, the correlation between tracer uptake and tumor grading or other biological characteristics, needs validation with further studies	[19, 21–28]
^111In-octreotide and ^99mTc-depreotide	SPECT, SSTR	High sensitivity and negative predictive value, differential diagnosis from somatostatin receptor-negative and orbital tumours, differentiation between postoperative scar and recurrence, selection of patients for somatostatin analogue-based therapies	Specificity depends on the BBB integrity, difficulty in detecting small tumors, limited imaging properties of ^111In, few studies with ^99mTc-depreotide	[42–59, 65]
^18F-FDG	PET, brain glucose metabolism	Prognostic information (prediction of recurrence and survival)	High uptake in normal gray matter not tumor specific	[44, 66–73]
^11C or ^18F labeled amino acids	PET, protein synthesis	High tumor/background ratio, identification of skull base meningiomas, improve target volume definition for RT	Not useful for grading	[67, 76–83]
^11C-choline	PET, phospholipid synthesis	Meningioma grading	Few studies	[87, 88]
1-^11C-acetate	PET	Accurate tumor delineation, guiding the stereotactic biopsy, optimizing treatment planning before radiosurgery	Not useful for grading, few studies	[72]
^13N-NH3	PET, analog of K^+	High tumor/background ratio	Not useful for grading, Few studies	[99]
^68Ga-DOTATOC	PET, SSTR	High tumor/background ratio, identification of skull base and en plaque meningioma and local osseous invasiveness, improvement of target volume definition for RT, recurrent disease, selection of patients for hormonal treatment or the use of DOTATOC labelled with β-emitting radionuclides	Uptake in parasellar lesions	[102, 103, 105–111]

Pgp: P-glycoprotein, SSTR: somatostatin receptors, BBB: Blood Brain Barrier, RT: Radiation Treatment.