18F-DOPA uptake parameters in glioma: effects of patients' characteristics and prior treatment history.

Temozolomide chemotherapy and patients' characteristics, including gender and age, affect physiological [18F]-fluoro-l-phenylalanine uptake and, consequently, the calculation of TBRs. Advances in knowledge: For the first time, the effects of past or concurrent temozolomide chemotherapy on brain physiological amino acid uptake have been investigated. Such effects are relevant and should be taken into account when evaluating tumour-to-background ratios.