Comparison of Five Segmentation Tools for {sup 18}F-Fluoro-Deoxy-Glucose-Positron Emission Tomography-Based Target Volume Definition in Head and Neck Cancer

Journal Article · Thu Nov 15 04:00:00 EST 2007 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2007.07.2333· OSTI ID:21039646

Vogel, Wouter V ^[1]; Hoffmann, Aswin L ^[2]; Dalen, Jorn A. van; Oyen, Wim J ^[1]

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1. Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)
2. Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

Purpose: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with {sup 18}F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may improve definition of the gross tumor volume (GTV). In this study, five methods for tumor delineation on FDG-PET are compared with CT-based delineation. Methods and Materials: Seventy-eight patients with Stages II-IV squamous cell carcinoma of the head and neck area underwent coregistered CT and FDG-PET. The primary tumor was delineated on CT, and five PET-based GTVs were obtained: visual interpretation, applying an isocontour of a standardized uptake value of 2.5, using a fixed threshold of 40% and 50% of the maximum signal intensity, and applying an adaptive threshold based on the signal-to-background ratio. Absolute GTV volumes were compared, and overlap analyses were performed. Results: The GTV method of applying an isocontour of a standardized uptake value of 2.5 failed to provide successful delineation in 45% of cases. For the other PET delineation methods, volume and shape of the GTV were influenced heavily by the choice of segmentation tool. On average, all threshold-based PET-GTVs were smaller than on CT. Nevertheless, PET frequently detected significant tumor extension outside the GTV delineated on CT (15-34% of PET volume). Conclusions: The choice of segmentation tool for target-volume definition of head and neck cancer based on FDG-PET images is not trivial because it influences both volume and shape of the resulting GTV. With adequate delineation, PET may add significantly to CT- and physical examination-based GTV definition.

• OSTI ID: 21039646
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 69; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
FLUORINE 18
FLUORODEOXYGLUCOSE
HEAD
IMAGES
NECK
NMR IMAGING
PATIENTS
POSITRON COMPUTED TOMOGRAPHY
UPTAKE