Is Image Registration of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Head-and-Neck Cancer Treatment Planning Necessary?

Journal Article · Thu Nov 01 04:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.12.071· OSTI ID:22149583

Fried, David; Lawrence, Michael ^[1]; Khandani, Amir H. ^[2]; Rosenman, Julian ^[1]; Cullip, Tim ^[1]

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1. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)
2. Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)

Purpose: To evaluate dosimetry and patterns of failure related to fluorodeoxyglucose-positron emission tomography (FDG-PET)-defined biological tumor volumes (BTVs) for head-and-neck squamous cell carcinoma (HNSCC) treated with definitive radiotherapy (RT). Methods and Materials: We conducted a retrospective study of 91 HNSCC patients who received pretreatment PET/CT scans that were not formally used for target delineation. The median follow-up was 34.5 months. Image registration was performed for PET, planning CT, and post-RT failure CT scans. Previously defined primary (CT{sub PRIMARY}) and nodal (CT{sub NODE}) gross tumor volumes (GTV) were used. The primary BTV (BTV{sub PRIMARY}) and nodal BTV (BTV{sub NODE}) were defined visually (PET{sub vis}). The BTV{sub PRIMARY} was also contoured using 40% and 50% peak PET activity (PET{sub 40,} PET{sub 50}). The recurrent GTVs were contoured on post-RT CT scans. Dosimetry was evaluated on the planning-CT and pretreatment PET scan. PET and CT dosimetric/volumetric data was compared for those with and without local-regional failure (LRF). Results: In all, 29 of 91 (32%) patients experienced LRF: 10 local alone, 7 regional alone, and 12 local and regional. BTVs and CT volumes had less than complete overlap. BTVs were smaller than CT-defined targets. Dosimetric coverage was similar between failed and controlled groups as well as between BTVs and CT-defined volumes. Conclusions: PET and CT-defined tumor volumes received similar RT doses despite having less than complete overlap and the inaccuracies of image registration. LRF correlated with both CT and PET-defined volumes. The dosimetry for PET- and/or CT-based tumor volumes was not significantly inferior in patients with LRF. CT-based delineation alone may be sufficient for treatment planning in patients with HNSCC. Image registration of FDG-PET may not be necessary.

• OSTI ID: 22149583
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 3 Vol. 84; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
CAT SCANNING
DOSIMETRY
FAILURES
FLUORODEOXYGLUCOSE
HEAD
IMAGES
NECK
PATIENTS
PLANNING
POSITRON COMPUTED TOMOGRAPHY
RADIATION DOSES
RADIOTHERAPY