{sup 18}F-FDG PET Definition of Gross Tumor Volume for Radiotherapy of Lung Cancer: Is the Tumor Uptake Value-Based Approach Appropriate for Lymph Node Delineation?
- Department of Radiation Oncology, Hospitales de la Esperanza y del Mar, Barcelona (Spain)
- PET Unit. Instituto de Alta Tecnologia (CRC-IAT), Barcelona (Spain)
Purpose: Positron emission tomography (PET) with the glucose analogue [18F] fluoro-2-deoxy-D-glucose ({sup 18}F-FDG-PET) has been used in radiation treatment planning for non-small-cell carcinoma. To date, lymph nodes have been contoured according to the uptake of the tumor. This prospective study was performed to evaluate if nodal volume delineates according to FDG uptake within the primary tumor (PET-GTVnt) is suitable for nodal target volume delineation or if individualized nodal FDG uptake measure (PET-GTVnn) is necessary to better nodal target definition. Methods and Materials: Forty cases, who underwent a diagnostic {sup 18}F-FDG PET/computed tomography (CT) scan, were included. Two PET-based GTVs for each lymph node were contoured and compared. First, we used an isocontour of 40% of the maximum tumor uptake (PET-GTVnt). Second, an isocontour of 40% of the maximum uptake of each node (PET-GTVnn) was employed. To avoid interobserver variability, this was carried out by the same radiation oncologist. Afterwards, the difference between both lymph node volumes was plotted against the ratio of the maximum uptakes (I{sub n}/I{sub t}) in a linear regression analysis. Results: Compared with CT-based lymph node volume (CT-GTVn), the intraclass correlation coefficient of PET-GTVnn was higher than the coefficient of PET-GTVnt (p < 0.001). All cases could be divided into four groups: undetected (17.5%), detected but overestimated (10%), detected but underestimated (35%), and correctly detected (37.5%). Conclusions: If a method of automatic delineation shall be applied, this method must be applied to every lesion separately. However, to facilitate the delineation in daily practice, when I{sub n}/I{sub t} is {<=}25%, lymph nodes could be delineated in accordance with tumor uptake, keeping an absolute difference in radii <5 mm.
- OSTI ID:
- 21437992
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 78, Issue 3; Other Information: DOI: 10.1016/j.ijrobp.2009.08.003; PII: S0360-3016(09)02959-9; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
Similar Records
A Prospective Evaluation of Staging and Target Volume Definition of Lymph Nodes by {sup 18}FDG PET/CT in Patients With Squamous Cell Carcinoma of Thoracic Esophagus
Analysis of Pretreatment FDG-PET SUV Parameters in Head-and-Neck Cancer: Tumor SUV{sub mean} Has Superior Prognostic Value
Related Subjects
CARCINOMAS
CAT SCANNING
FLUORINE 18
FLUORODEOXYGLUCOSE
LUNGS
LYMPH NODES
POSITRON COMPUTED TOMOGRAPHY
RADIOTHERAPY
ANTIMETABOLITES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
EMISSION COMPUTED TOMOGRAPHY
FLUORINE ISOTOPES
HOURS LIVING RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
LYMPHATIC SYSTEM
MEDICINE
NANOSECONDS LIVING RADIOISOTOPES
NEOPLASMS
NUCLEAR MEDICINE
NUCLEI
ODD-ODD NUCLEI
ORGANS
RADIOISOTOPES
RADIOLOGY
RESPIRATORY SYSTEM
THERAPY
TOMOGRAPHY