Dear Sir, We read with great interest the “EANM procedure guidelines for brain tumour imaging using labelled amino acid analogues” that were published in the November issue of the Eur J Nucl Med Mol Imaging [1]. The publication of an EANM guideline is a professional event of major importance, and the present most valuable work is based on an extensive survey of the literature. However, we would suggest that 6-fluoro-(F)-L-3,4dihydroxyphenylalanine (FDOPA) needs to be included in the limited guideline list of radiopharmaceuticals. FDOPA is clearly a “labelled amino acid analogue” and is currently registered in France for brain tumour imaging, while the three other radiopharmaceuticals that are listed in the guideline [iodomethyltyrosine-(I) or IMT, methionine(C) or MET or fluoroethylthyrosine-(F) or FET] have no marketing authorisation. We would like to briefly summarise the published data that support the use of FDOPA PET in brain tumours and thus favour a limited revision of the guidelines. The first description of imaging of a brain tumour with FDOPA PET was a case report by Heiss in 1996 [2]. A 57year-old woman suffering from a minor movement disorder of the left arm and hand was referred for FDOPA PET. The FDOPA PET study not only proved asymmetrically reduced dopamine uptake in the putamen, but also revealed pathologically increased FDOPA accumulation in the right frontal lobe. Further PET examinations demonstrated increased MET uptake and low glucose metabolism in this right frontal region. Histology confirmed the diagnosis of a grade 2 oligo-astrocytoma. In 2003, Becherer et al. [3] reported on the performance of FDOPA PET in this setting, in comparison with MET, in series of 20 patients with known supratentorial brain lesions. The diagnoses were 18 primary brain tumours, one metastasis and one non-neoplastic cerebral lesion. MET and FDOPA images matched in all patients and showed all lesions as hot spots with higher uptake than in the contralateral brain. Standardised uptake value ratios for the tumour to the contralateral side (mean±SD) were similar for MET and FDOPA: 2.05±0.91 vs 2.04±0.53. The benign lesion, which biopsy revealed to be focal demyelination, was false positive, showing increased uptake of both MET and FDOPA. Recently, Chen et al. [4] compared the diagnostic performance of FDOPA PET and FDG PET in 30 patients with brain tumours: seven at diagnosis and 23 in whom recurrence was suspected. Visual analysis, considering as malignant any focus with an intensity greater than that of background, revealed a greater sensitivity for FDOPA (22/23=96% vs.14/23=61% for FDG), with an identical specificity: 3/7=43%. In fact, this low specificity was due to three cases with post-irradiation necrotic areas that faintly took up FDOPA to a much lesser extent than viable tumour tissue but that nevertheless had to be considered false positive results at visual analysis. To solve this problem, the authors proposed use of the tumour/striatum activity ratio, with a cut-off value of 0.75. The validity of this proposal was tested in another series of 51 patients including 47 with Eur J Nucl Med Mol Imaging (2007) 34:1131–1132 DOI 10.1007/s00259-007-0400-y