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Updated: Feb 11, 2026
08:54
Treatment of Liver Metastases Using an Internal Target Volume Method for Stereotactic Body Radiotherapy
Published on: May 8, 2018
15.0K
Radiotherapy volume delineation using 18F-FDG-PET/CT modifies gross node volume in patients with oesophageal cancer
E Jimenez-Jimenez1, P Mateos2, N Aymar3
1Radiation Oncology Department, St. Lucia University General Hospital, Cartagena, Spain. estherjj83@gmail.com.
Summary
18F-FDG-PET/CT scans significantly increase gross node volume (GTVnode) in esophageal cancer patients compared to CT simulation alone. This suggests CT simulation may omit cancerous nodes from radiotherapy planning.
Area of Science:
- Oncology
- Radiotherapy
- Medical Imaging
Background:
- Radiotherapy planning for esophageal cancer relies on accurate tumor delineation.
- Current methods using CT simulation may not fully capture the extent of nodal involvement.
Purpose of the Study:
- To compare tumor and lymph node volumes defined by fused 18F-FDG-PET/CT versus CT simulation for esophageal cancer.
- To assess the impact of PET/CT on radiotherapy planning volumes.
Main Methods:
- Retrospective analysis of 29 esophageal cancer patients.
- Definition of two gross tumor volumes (GTVs): one from CT alone, another from fused PET/CT.
- Comparison of volumetric data and spatial overlap using Dice Similarity Coefficient (DSC).
Main Results:
- Gross tumor volume (GTVtumour) and maximum diameter were larger with PET/CT, but not significantly.
- Gross node volume (GTVnode) was significantly larger with PET/CT.
- Excellent agreement for GTVtumour (DSC=0.72), but very low agreement for GTVnode (DSC=0.25).
Conclusions:
- PET/CT and CT simulation yield different volume definitions for esophageal cancer.
- CT simulation alone may lead to underestimation of cancerous lymph nodes, potentially excluding them from radiotherapy fields.
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