Review Article

The Clinical Value of PET with Amino Acid Tracers for Gliomas WHO Grade II

Table 2

Clinical applications of 11C-methionine uptake measured by PET in adult low-grade gliomas (LGGs).

StudyStudy designTumor subtype1 no. of patientsResults and/or conclusion

Evaluation of response to chemotherapy

Tang et al. [54]Retrospective review Chemosensitivity to PCV Measures: activity volume index (AVI), FLAIR-MRI7 OIIPCV associated with drastic decrease in AVI; less pronounced decrease in tumor volume on FLAIR-MRI
Wyss et al. [72]Prospective study TMZ in progressive nonenhancing tumors Measures: FET ratio, FET volume, and MRI11 LGGs (3 OII, 4 AII, 4 AOII)Changes in FET preceded and more pronounced than MRI changes; decrease FET ratio < FET volume in responders

Differentiating recurrent tumor from changes induced by radiotherapy

Van Laere et al. [73]Retrospective review Differential diagnosis radionecrosis-recurrence Measures: MET ratio, FDG ratio, histology, and survival30 gliomas (15 LGGs: 8 AAII, 3 OAII, 4 OII)FDG and MET ratio significant parameters for survival; FDG and MET strongest prognostic accuracy; MET alone strongest prognostic factor for astrocytomas
Terakawa et al. [74]Retrospective review Differential diagnosis radionecrosis-recurrence Measures: MET ratio (L/N mean, L/N max, lesion/normal frontal cortex), histology77 patients (26 gliomas: 6 grade II, 6 grade III and 14 GB; 51 metastases)L/N mean with cutoff 1.58 most informative for glioma (75% sensitivity, 75% specificity); L/N max not informative for glioma

Long-term followup and prognosis

Nuutinen et al. [63]Prospective long-term followup Measures: MET ratio, MET volume, histology, and survival14 gliomas (13 AII and 1 AIII)Met ratio and volume: 80% sensitivity in detecting residual postoperative tumor; baseline MET ratio of prognostic value
Ribom et al. [75]Retrospective review Pretreatment MET Measures: MET ratio, MET volume (untreated versus after surgery/radio- and/or chemotherapy), time-to-progression (TPP)32 LGGs (11 AII, 6 OAII, 15 OII)Untreated patients: longest TTP when stable MET ratio and small volume increase; treated patients: initial treatment effects (reduction MET ratio, volume or in both) but no prognostic value
Ullrich et al. [76]Prospective long-term followup Measures: MET ratio, histology, and molecular tumor profile24 gliomas (10 AII, 7 OAII, 1 OII, 3 AIII, 3 OAIII)Mean increase of MET in patients with progression 54.4% versus 3.9% in patients with stable disease; correlation increased MET and VEGF expression
Ribom et al. [77]Retrospective review Preoperative MET Measures: MET ratio, and survival89 LGGs (33 AII, 17 OAII, 39 OII)Preoperative MET ratio prognostic factor for survival in AII and OII
De Witte et al. [78]Retrospective review Preoperative (n = 74) and postoperative (n = 11) MET Measures: MET ratio, survival85 gliomas (28 LGGs: 12 AII, 4 OAII, 12 OII)MET ratio prognostic factor for survival in grade II and grade III gliomas
Floeth et al. [79]Prospective followup Histologically verified LGGs Measures: FET ratio, growth pattern on MRI (diffuse versus circumscribed), survival33 LGGs (27 AII, 2 OAII, 4 OII)3 major subtypes: (1) low FET ratio and circumscribed on MRI most favorable outcome,(2) positive FET ratio and circumscribed on MRI intermediate outcome,(3) positive FET ratio and diffuse on MRI unfavorable outcome

ā€‰1Abbreviations: LGGs: low-grade gliomas; AI: pilocytic astrocytoma; AII: astrocytoma grade II; OII: oligodendroglioma grade II; OAII: oligoastrocytoma grade II; AIII: astrocytoma grade III; OAIII: oligoastrocytoma grade III; GB: glioblastoma.