Abstract
BackgroundDelineation of glioma extent for surgical or radiotherapy planning is routinely based on MRI. There is increasing awareness that contrast enhancement on T1-weighted images (T1-CE) may not reflect the entire extent of disease. The amino acid tracer 18F-DOPA (3,4-dihydroxy-6-[18F] fluoro-l-phenylalanine) has a high tumor-to-background signal and high sensitivity for glioma imaging. This study compares 18F-DOPA PET against conventional MRI for neurosurgical biopsy targeting, resection planning, and radiotherapy target volume delineation.MethodsConventional MR and 18F-DOPA PET/CT images were acquired in 10 patients with suspected malignant brain tumors. One to 3 biopsy locations per patient were chosen in regions of concordant and discordant 18F-DOPA uptake and MR contrast enhancement. Histopathology was reviewed on 23 biopsies. 18F-DOPA PET was quantified using standardized uptake values (SUV) and tumor-to-normal hemispheric tissue (T/N) ratios.ResultsPathologic review confirmed glioma in 22 of 23 biopsy specimens. Thirteen of 16 high-grade biopsy specimens were obtained from regions of elevated 18F-DOPA uptake, while T1-CE was present in only 6 of those 16 samples. Optimal 18F-DOPA PET thresholds corresponding to high-grade disease based on histopathology were calculated as T/N > 2.0. In every patient, 18F-DOPA uptake regions with T/N > 2.0 extended beyond T1-CE up to a maximum of 3.5 cm. SUV was found to correlate with grade and cellularity.Conclusions18F-DOPA PET SUVmax may more accurately identify regions of higher-grade/higher-density disease in patients with astrocytomas and will have utility in guiding stereotactic biopsy selection. Using SUV-based thresholds to define high-grade portions of disease may be valuable in delineating radiotherapy boost volumes.
Original language | English (US) |
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Pages (from-to) | 1058-1067 |
Number of pages | 10 |
Journal | Neuro-oncology |
Volume | 15 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2013 |
Keywords
- F-DOPA PET
- PET-MRI image registration
- glioma target delineation
- image-guided biopsy planning
- image-guided radiation therapy
ASJC Scopus subject areas
- Oncology
- Clinical Neurology
- Cancer Research