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The diagnostics of recurrent gliomas using FDG-PET: still questionable?
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Abstract
MATERIAL AND METHODS: MRI and FDG-PET were used to examine 29 patients for suspicious glioma recurrence, after 30 open neurosurgical operations or re-operations combined with chemo- and/or radiotherapy. The sensitivity, specificity and accuracy of both examinations were calculated with respect to their micromorphological findings (n = 28) or the clinical and radiological follow-up (n = 2).
RESULTS: MRI detected 23/24 tumour recurrences (sensitivity = 95.8%) and FDG PET only 15 of these (sensitivity = 62.5%). MRI specified only 3/6 radionecrotic lesions (specificity = 50.0%), while FDG PET identified 5/6 (specificity = 83.3%). Overall accuracy was 26/30 (86.7%) for MRI and 20/30 (66.7%) for FDG PET. In the subgroup of MRI positive or equivocal findings (n = 29) FDG PET was clearly positive in 15 cases. High-grade glioma recurrence was subsequently confirmed in all of them. On the other hand negative or equivocal FDG PET was associated in 5/14 cases (35.7%) with radionecrosis, in 3/14 (21.4%) with low-grade glioma and in 6/14 (42.9%) with high-grade glioma.
CONCLUSIONS: MRI is the method of choice for the detection of glioma recurrence but it is associated with a high rate of false positive results. FDG PET has significantly lower sensitivity; nevertheless it does help to specify MRI positive lesions. FDG PET positive lesions give a very high probability of high-grade glioma, but its equivocal and negative findings are of no clinical value.
Abstract
MATERIAL AND METHODS: MRI and FDG-PET were used to examine 29 patients for suspicious glioma recurrence, after 30 open neurosurgical operations or re-operations combined with chemo- and/or radiotherapy. The sensitivity, specificity and accuracy of both examinations were calculated with respect to their micromorphological findings (n = 28) or the clinical and radiological follow-up (n = 2).
RESULTS: MRI detected 23/24 tumour recurrences (sensitivity = 95.8%) and FDG PET only 15 of these (sensitivity = 62.5%). MRI specified only 3/6 radionecrotic lesions (specificity = 50.0%), while FDG PET identified 5/6 (specificity = 83.3%). Overall accuracy was 26/30 (86.7%) for MRI and 20/30 (66.7%) for FDG PET. In the subgroup of MRI positive or equivocal findings (n = 29) FDG PET was clearly positive in 15 cases. High-grade glioma recurrence was subsequently confirmed in all of them. On the other hand negative or equivocal FDG PET was associated in 5/14 cases (35.7%) with radionecrosis, in 3/14 (21.4%) with low-grade glioma and in 6/14 (42.9%) with high-grade glioma.
CONCLUSIONS: MRI is the method of choice for the detection of glioma recurrence but it is associated with a high rate of false positive results. FDG PET has significantly lower sensitivity; nevertheless it does help to specify MRI positive lesions. FDG PET positive lesions give a very high probability of high-grade glioma, but its equivocal and negative findings are of no clinical value.
Keywords
glioma; recurrence; radionecrosis; FDG; PET
Title
The diagnostics of recurrent gliomas using FDG-PET: still questionable?
Journal
Issue
Pages
127-130
Published online
2002-06-07
Page views
608
Article views/downloads
1226
Bibliographic record
Nucl. Med. Rev 2002;5(2):127-130.
Keywords
glioma
recurrence
radionecrosis
FDG
PET
Authors
Otakar Belohlávek
Jan Klener
Josef Vymazal
Vladimir Dbaly
František Tovaryš