[Convenient Approach to Improve Correlation between Geometry and Dosimetric Parameters for Automatic Segmentation in
Tingting Li1, Anning Cao1, Jianying Zhang1
1Department of Radiotherapy, Zhongshan Hospital, Fudan University, Shanghai, 200032.
Summary
New geometric indexes correlate overlapping structures with organ doses, improving radiotherapy planning for upper abdomen cancers. These parameters predict acceptable maximum dose differences from automatic segmentation, enhancing treatment safety.
Area of Science:
- Radiotherapy
- Medical Physics
- Radiation Oncology
Background:
- Accurate segmentation of organs at risk (OARs) is crucial for safe radiotherapy.
- Geometric parameters can potentially correlate with dosimetric outcomes.
Purpose of the Study:
- To develop geometric indexes for improved correlation between geometric and dosimetric parameters.
- To assess the predictive value of overlapping structures in radiotherapy planning.
Main Methods:
- Selected 48 upper abdomen cases.
- Performed manual and automatic segmentation for stomach and duodenum.
- Generated overlapping structures with target expansions (5, 10, 20 mm) and calculated geometric parameters.
Main Results:
- Geometric parameters >0.4, >0.6, and >0.8 for 5, 10, and 20 mm target expansions, respectively, resulted in <3 Gy maximum dose differences.
- Recommended 20 mm target expansion overlap for safety in cases with no overlap.
Conclusions:
- Overlapping geometric parameters strongly correlate with OAR maximum dose in upper abdomen radiotherapy.
- These parameters can predict the clinical acceptability of maximum dose differences from auto-segmentation.
