BACKGROUND: We sought to assess the impact of @entity535 (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade @entity11 versus the current standard using MRI alone. Specifically, we investigated the influence of @entity5 grade, MR-defined @entity5 volume, and the extent of surgical resection on PET positivity. METHODS: Fifty-four consecutive high-grade @entity11 @entity1 (World Health Organization grades III-IV) with confirmed histology were scanned using FET-PET/CT and T1 and T2/fluid attenuated inversion recovery MRI. Gross @entity5 volume and clinical target volumes (CTVs) were defined in a blinded fashion based on MRI and subsequently PET, and volumetric analysis was performed. The extent of the surgical resection was reviewed using postoperative MRI. RESULTS: Overall, for    90% of the @entity1 , the PET-positive volumes were encompassed by T1 MRI with contrast-defined @entity5 plus a 20-mm margin. The @entity5 volume defined by PET was larger for @entity11 grade IV (P < .001) and smaller for @entity1 with more extensive surgical resection (P = .004). The margin required to be added to the MRI-defined @entity5 in order to fully encompass the FET-PET positive volume tended to be larger for grade IV @entity5 (P = .018). CONCLUSION: With an unchanged CTV margin and by including FET-PET for gross @entity5 volume definition, the CTV will increase moderately for most @entity1 , and quite substantially for a minority of @entity1 . @entity1 with grade IV @entity11 were found to be the primary candidates for PET-guided radiation therapy planning.

Impact of [18F]-fluoro-ethyl-tyrosine PET imaging on target definition for radiation therapy of high-grade XXXX .

@entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino-acid'] @entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity11 :: ('MESH:D005910', 'Disease') :: ['glioma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors']
@entity11 :: (MESH:D005910,Disease) :: ['glioma']
