Is Image Registration of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Head-and-Neck Cancer Treatment Planning Necessary?
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)
- 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, Vol. 84, Issue 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
Similar Records
SU-D-202-01: Functional Lung Avoidance and Response-Adaptive Escalation (FLARE) RT: Feasibility of a Precision Radiation Oncology Strategy
Combined {sup 18}F-FDG-PET/CT Imaging in Radiotherapy Target Delineation for Head-and-Neck Cancer