Cardiac substructure delineation in radiation therapy - A state-of-the-art review

Area of Science:

• Medical Physics
• Radiation Oncology
• Cardiology

Background:

• Cardiac substructure delineation is critical for assessing radiation-related cardiotoxicities and precise dose calculations in radiation therapy (RT).
• Current imaging techniques for RT planning pose challenges in visualizing cardiac anatomy accurately.
• Despite atlases and guidelines, defining cardiac anatomy remains uncertain, necessitating automated solutions.

Purpose of the Study:

• To review advancements in cardiac substructure delineation within the radiation therapy context.
• To provide an overview of current knowledge, challenges, and future directions in cardiac delineation.
• To highlight the need for improved auto-contouring models for clinical integration.

Main Methods:

• Review of recent literature on cardiac substructure delineation in radiation therapy.
• Analysis of the performance and limitations of auto-contouring models.
• Discussion of challenges in imaging, standardization, and model development.

Main Results:

• Auto-contouring models, initially developed for breast and lung cancer RT, demonstrate performance comparable to manual delineation.
• These automated methods offer potential for consistent large-scale data analysis and improved efficiency.
• Significant concerns remain regarding the expansion of models to diverse cancer sites and enhancing their robustness and accessibility.

Conclusions:

• Auto-contouring represents a significant advancement in cardiac delineation for radiation therapy.
• Further research is needed to broaden the application of these models across various cancer types.
• Enhancing the robustness and accessibility of auto-contouring is crucial for integrating cardiac risk models into routine clinical practice and improving patient safety.