Uptake of 4-borono-2-[18F]fluoro-L-phenylalanine in sporadic and neurofibromatosis 2-related schwannoma and meningioma studied with PET.

Abstract

PURPOSE:

Meningiomas and schwannomas associated with neurofibromatosis 2 (NF2) are difficult to control by microsurgery and stereotactic radiotherapy alone. Boron neutron capture therapy (BNCT) is a chemically targeted form of radiotherapy requiring increased concentration of boron-10 in tumour tissue. PET with the boron carrier 4-borono-2-[(18)F]fluoro-L-phenylalanine ([(18)F]FBPA) allows investigation of whether 4-borono-L-phenylalanine (BPA) concentrates in NF2 tumours, which would make BNCT feasible.

METHODS:

We studied dynamic uptake of [(18)F]FBPA in intracranial meningiomas (n=4) and schwannomas (n=6) of five sporadic and five NF2 patients. Tracer input function and cerebral blood volume were measured. [(18)F]FBPA uptake in tumour and brain was assessed with a three-compartmental model and graphical analysis. These, together with standardised uptake values (SUVs), were used to define tumour-to-brain [(18)F]FBPA tissue activity gradients.

RESULTS:

Model fits with three parameters K (1) (transport), k (2) (reverse transport) and k (3) (intracellular metabolism) were found to best illustrate [(18)F]FBPA uptake kinetics. Maximum SUV was two- to fourfold higher in tumour as compared with normal brain and independent of NF2 status. The increased uptake was due to higher transport of [(18)F]FBPA in tumour. In multiple-time graphical analysis (MTGA, Gjedde-Patlak plot) the tumour-to-brain [(18)F]FBPA influx constant (K (i) -MTGA) ratios varied between 1.8 and 5.4 in NF2-associated tumours while in sporadic tumours the ratio was 1-1.4.

CONCLUSION:

[(18)F]FBPA PET offers a viable means to evaluate BPA uptake in meningiomas and schwannomas in NF2. Based on our results on tumour uptake of [(18)F]FBPA, some of these benign neoplasms may be amenable to BNCT.

• Authors: Katja Havu-Aurén, Johanna Kiiski, Kaisa Lehtiö, Olli Eskola, Martti Kulvik, Ville Vuorinen, Vesa Oikonen, Jyrki Vähätalo, Juha Jääskeläinen, Heikki Minn
• Journal: European journal of nuclear medicine and molecular imaging (Eur J Nucl Med Mol Imaging) Vol. 34 Issue 1 Pg. 87-94 (Jan 2007) ISSN: 1619-7070 [Print] Germany
• PMID: 16896669 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Boron Compounds
• Radiopharmaceuticals
• 4-borono-2-fluorophenylalanine
• Phenylalanine

Topics

• Adult
• Boron Compounds (pharmacokinetics, therapeutic use)
• Boron Neutron Capture Therapy (methods)
• Brain Neoplasms (diagnostic imaging, etiology, metabolism, radiotherapy)
• Female
• Humans
• Male
• Meningeal Neoplasms (diagnostic imaging, etiology, metabolism, radiotherapy)
• Meningioma (diagnostic imaging, etiology, metabolism, radiotherapy)
• Middle Aged
• Neurilemmoma (diagnostic imaging, etiology, metabolism, radiotherapy)
• Neurofibromatoses (complications, diagnostic imaging, metabolism, radiotherapy)
• Phenylalanine (analogs & derivatives, pharmacokinetics, therapeutic use)
• Positron-Emission Tomography (methods)
• Radiopharmaceuticals (pharmacokinetics, therapeutic use)