6th Annual Brain Tumor Conference: GBM Tumors

GBM Tumors
Dr. Cloughsey

Surgery
- no randomized data regarding extend of resection
- retrospective studies found extent of resection positively correlates with survival
Radiation Therapy
- external beam radiotherapy : fractionated schedule, brain volume to be radiated, radio sensitizers
- brachytherapy (radioactive seeds): location and size limits, selection bias (only valid on certain types of tumors)
- radiosurgery: local treatment for a widespread process?
- Current standard is 60 Gy, 3D: conformal
- Randomized study of brachytherapy - no difference in survival of group that didn't get it (not offered for malignant gliomas now)
- Trial with radiosurgery (gamma knife, x knife, etc) showed no benefit found (RTOG-9305) not used for GBM in upfront setting
- Surgery is the best thing to do, radiation therapy (60Gy fractionated)
Chemotherapy
- Temodar first chemo that showed a benefit in survival rate
- Anaplastic Astrocytoma doesn't necessarily get the same treatment as GBM
- If Methylated MGMT present, indicates that Temodar will work better
- Temodar currently not used longer than 2 years
Recurrence
- treatment options: surgery (mass effect pressure relief or to determine if radiation necrosis vs. tumor or to participate in trial for recurrent), radiation therapy (risky if in place already radiated, possible to go over tolerance of normal brain, could cause necrosis, mass effect or swelling), chemo therapies (20% benefit of patients being stable after 6 months)
- lower grade tumors can come back as higher grade tumors, grade IV tumors come back as grade IV but can be more aggressive than before
- 85% of the time, comes back within 2-3 cm of original tumor