PURPOSE: A limitation of [ @entity8984 ] @entity419 positron emission tomography (FDGPET) in radiation planning for @entity978 ( @entity978 ) is significant variability in delineation of @entity5 volume. One approach to reduce variability is to apply automatic or semiautomatic segmentation methods such as thresholding based on a percent @entity5 maximum standardized uptake value (SUVmax). Here, we apply various @entity5 SUVmax thresholds and examine their effects in involved field radiation therapy (IFRT) and involved site radiation therapy (ISRT) target volumes. METHODS AND MATERIALS: PET/computed tomography data sets were reviewed for 16 pediatric and young adult @entity1 treated with IFRT. The following percent @entity5 SUVmax thresholds were applied to the prechemotherapy PET: 15%, 20%, 25%, 30%, 35%, and 40%. Clinical target volumes for IFRT and ISRT plans were manually generated based on these threshold volumes (CTVPET) and compared with clinical target volumes generated using the standard qualitative visual method (CTVQVM). Treatment plans were generated, doses to normal structures were compared, and the optimum threshold, defined as the CTVPET that corresponded to the percent overlap closest to 100% when compared with the CTVQVM, was determined. RESULTS: On average, there was a 7.6-fold increase in PET volume between 40% and 15% SUVmax. When the 6 SUVmax thresholds were applied in the design of target volumes for IFRT, 2 of 16 @entity1 had a change in treatment volume. There was a 2.4-fold increase in ISRT CTVs generated based on the 15% and 40% SUVmax, which translated into a clinically significant decrease in dose to normal structures when the ISRT plans that were generated using the 15% SUVmax volumes were compared with the 40% SUVmax. In most @entity1 , the optimum threshold was SUVmax 15%. CONCLUSIONS: Accurate target volume delineation with @entity8983 PET in @entity978 is challenging and may require more precise and reproducible segmentation methods as we move toward more conformal therapies.

Use of standardized uptake value thresholding for target volume delineation in pediatric XXXX .

@entity8984 :: ('CHEBI:36939', 'Chemical') :: ['(18)F'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity419 :: ('MESH:D019788', 'Chemical') :: ['2-fluoro-2-deoxy-d-glucose'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity978 :: ('MESH:D006689', 'Disease') :: ['HL', 'Hodgkin lymphoma'] @entity8983 :: ('CHEBI:49134', 'Chemical') :: ['[(18)F] 2-fluoro-2-deoxy-d-glucose']
@entity978 :: (MESH:D006689,Disease) :: ['Hodgkin lymphoma']
