Biopsy validation of 18F-DOPA PET and biodistribution in gliomas for neurosurgical planning and radiotherapy target delineation: results of a prospective pilot study

Neuro Oncol. 2013 Aug;15(8):1058-67. doi: 10.1093/neuonc/not002. Epub 2013 Mar 3.


Background: Delineation 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 (18)F-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 (18)F-DOPA PET against conventional MRI for neurosurgical biopsy targeting, resection planning, and radiotherapy target volume delineation.

Methods: Conventional MR and (18)F-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 (18)F-DOPA uptake and MR contrast enhancement. Histopathology was reviewed on 23 biopsies. (18)F-DOPA PET was quantified using standardized uptake values (SUV) and tumor-to-normal hemispheric tissue (T/N) ratios.

Results: Pathologic review confirmed glioma in 22 of 23 biopsy specimens. Thirteen of 16 high-grade biopsy specimens were obtained from regions of elevated (18)F-DOPA uptake, while T1-CE was present in only 6 of those 16 samples. Optimal (18)F-DOPA PET thresholds corresponding to high-grade disease based on histopathology were calculated as T/N > 2.0. In every patient, (18)F-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.

Conclusions: (18)F-DOPA PET SUV(max) 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.

Keywords: 18F-DOPA PET; PET-MRI image registration; glioma target delineation; image-guided biopsy planning; image-guided radiation therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Brain Neoplasms / diagnostic imaging
  • Brain Neoplasms / pathology*
  • Brain Neoplasms / surgery
  • Dihydroxyphenylalanine / analogs & derivatives*
  • Dihydroxyphenylalanine / pharmacokinetics
  • Female
  • Follow-Up Studies
  • Glioma / diagnostic imaging
  • Glioma / pathology*
  • Glioma / surgery
  • Humans
  • Immunoenzyme Techniques
  • Male
  • Middle Aged
  • Neoplasm Grading
  • Neurosurgical Procedures*
  • Pilot Projects
  • Positron-Emission Tomography*
  • Prognosis
  • Prospective Studies
  • Radiopharmaceuticals* / pharmacokinetics
  • Radiotherapy Planning, Computer-Assisted*
  • Radiotherapy, Image-Guided
  • Surgery, Computer-Assisted
  • Tissue Distribution
  • Young Adult


  • Radiopharmaceuticals
  • fluorodopa F 18
  • Dihydroxyphenylalanine