from : 2008 Society for Neuro-Oncology Meeting Abstracts
PET
IMAGING APPLICATIONS IN PROTON BEAM THERAPY FOR
GLIOMA
by Michael Meyer, MD
Although proton
beam therapies for prostate
cancer and other
neoplasms
including chordomas are fairly well developed, there has been
relatively little research on the potential use of the proton
beam
approach to treat gliomas. This study reviews the limited clinical
literature on this topic, and proposes the use of finely collimated
proton beams to target hyper-metabolic regions
within gliomas, as
identified on pre-treatment 18F-FDG PET scans. Due to the
14N(p,alpha)11C reaction, in vivo generation of 11C occurs with proton
beam exposure, allowing for post-treatment monitoring of beam accuracy
within the brain with the use of PET. By the application of multiple,
finely collimated proton beams focused at the
most hyper-metabolic
region of a glioma, exposure of normal brain tissue can be minimized,
with most of the energy deposited at one intra-tumoral focal point.
Integration of data from a PET/CT system into Proton
Beam therapy
planning is proposed here as an effective way to not only choose
targets for radiation, but to then use the phenomenon of proton
induced
tissue activation to then monitor the accuracy of beam delivery in
addition to post-treatment 18F-FDG PET imaging to assess the metabolic
response.
