2-fluoro-2-deoxyglucose-6-phosphate and Brain-Neoplasms

The routine use of integrated positron emission tomography computed tomography in the staging and follow-up of patients diagnosed with non-small-cell lung cancer has improved diagnostic accuracy but many incidental extrathoracic findings are routinely encountered. These include physiologic fluorodeoxy glucose avid foci, normal computed tomography variants, and second primary malignancies, all of which have to be differentiated from extrathoracic metastatic disease. Knowledge of these findings is important for correct staging and identification of second primaries.

Topics: Adipose Tissue; Bone Marrow; Brain Neoplasms; Carcinoma, Non-Small-Cell Lung; Glucose-6-Phosphate; Head and Neck Neoplasms; Humans; Lymphatic Metastasis; Positron-Emission Tomography; Thoracic Neoplasms; Thyroid Gland; Tomography, X-Ray Computed; Vocal Cord Paralysis

Glioblastoma multiforme (GBM) continues to be a difficult therapeutic challenge. Our study was conducted to determine whether improved survival and tumor control could be achieved with modern delivery of fast neutron radiation using three-dimensional treatment planning. Ten patients were enrolled. Eligibility criteria included pathologic diagnosis of GBM, age >or=18 years, and KPS >or=60. Patients underwent MRI and (18)F-fluorodeoxyglucose PET (FDG PET) as part of initial three-dimensional treatment planning. Sequential targets were treated with noncoplanar fields to a total dose of 18 Gy in 16 fractions over 4 weeks. Median and 1-year overall survival were 55 weeks and 60%, respectively. One patient remains alive at last follow-up 255 weeks after diagnosis. Median progression-free survival was 16 weeks, and all patients had tumor progression by 39 weeks. Treatment was clinically well tolerated, but evidence of mild to moderate gliosis and microvascular sclerosis consistent with radiation injury was observed at autopsy in specimens taken from regions of contralateral brain that received approximately 6-10 Gy. Fast neutron radiation using modern imaging, treatment planning, and beam delivery was feasible to a total dose of 18 Gy, but tumor control probability was poor in comparison to that predicted from a dose-response model based on older studies. Steep dose-response curves for both tumor control and neurotoxicity continue to present a challenge to establishing a therapeutic window for fast neutron radiation in GBM, even with modern techniques.

Topics: Adult; Aged; Brain Neoplasms; Disease-Free Survival; Female; Glioblastoma; Glucose-6-Phosphate; Humans; Kaplan-Meier Estimate; Magnetic Resonance Imaging; Male; Middle Aged; Neutron Capture Therapy; Pilot Projects; Positron-Emission Tomography; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Conformal