Automatic base-dose planning for a robust field junction in total marrow irradiation.

Area of Science:

• Radiation Oncology
• Medical Physics
• Radiotherapy Planning

Background:

• Total marrow irradiation (TMI/TMLI) requires whole-body irradiation, often necessitating split plans due to linac limitations.
• Achieving adequate target coverage at the junction of split TMI/TMLI plans is challenging and requires careful field junction design.
• Previous work introduced an automatic tool (AT) for TMI/TMLI field junction creation and optimization.

Purpose of the Study:

• To enhance an existing automatic tool (AT) for TMI/TMLI by developing an automatic base-dose planning approach.
• To improve the accuracy and efficiency of field junction optimization in total marrow irradiation.

Main Methods:

• Ten patients underwent TMI/TMLI using three planning methods: manual, original AT, and the new base-dose AT.
• Treatment plans were evaluated based on dose statistics (D98%, Dmean, D2%) for the planning target volume at the junction (PTV_J), PTV without junction (PTVNoJ), and healthy tissues.

Main Results:

• The base-dose planning approach significantly improved PTV_J coverage (higher D98%, lower D2%) compared to the manual method.
• Hotspots in healthy tissues were significantly reduced with the base-dose approach.
• Target coverage for PTVNoJ remained consistent across all methods, indicating comparable overall target coverage.

Conclusions:

• Automatic base-dose planning effectively optimizes the field junction for TMI/TMLI, enhancing target coverage and reducing normal tissue toxicity.
• Automated planning tools offer a valuable solution for complex and potentially error-prone radiotherapy procedures like TMI/TMLI.