Keywords:
radiation
;
POSITRON-EMISSION-TOMOGRAPHY
;
COMPUTED-TOMOGRAPHY
;
PET
;
MOTION
;
CANCER NSCLC
;
CT SCANS
;
phantom
;
EARLY-STAGE
;
STEREOTACTIC ABLATIVE RADIOTHERAPY
Abstract:
PURPOSE: Evaluation of the effect of co-registered 4D-(18)FDG-PET/CT for SBRT target delineation in patients with central versus peripheral lung tumors. METHODS: Analysis of internal target volume (ITV) delineation of central and peripheral lung lesions in 21 SBRT-patients. Manual delineation was performed by 4 observers in 2 contouring phases: on respiratory gated 4DCT with diagnostic 3DPET available aside (CT-ITV) and on co-registered 4DPET/CT (PET/CT-ITV). Comparative analysis of volumes and inter-reader agreement. RESULTS: 11 cases of peripheral and 10 central lesions were evaluated. In peripheral lesions, average CT-ITV was 6.2cm(3) and PET/CT-ITV 8.6cm(3), resembling a mean change in hypothetical radius of 2mm. For both CT-ITVs and PET/CT-ITVs inter reader agreement was good and unchanged (0.733 and 0.716; p=0.58). All PET/CT-ITVs stayed within the PTVs derived from CT-ITVs. In central lesions, average CT-ITVs were 42.1cm(3), PET/CT-ITVs 44.2cm(3), without significant overall volume changes. Inter-reader agreement improved significantly (0.665 and 0.750; p〈0.05). 2/10 PET/CT-ITVs exceeded the PTVs derived from CT-ITVs by 〉1ml in average for all observers. CONCLUSION: The addition of co-registered 4DPET data to 4DCT based target volume delineation for SBRT of centrally located lung tumors increases the inter-observer agreement and may help to avoid geographic misses.
DOI:
10.1016/j.radonc.2015.05.019
Type of Publication:
Journal article published
Deep Link:
http://www.dkfz.de/cgi-bin/sel?http://www.dkfz.de/PublicationManager/Show/ShowJournal.aspx%3fpublishedId=62336
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