Dynamics-Adapted Radiotherapy Dose (DARD) for Head and Neck Cancer Radiotherapy Dose Personalization

Area of Science:

• Radiation Oncology
• Medical Physics
• Cancer Research

Background:

• Standard radiotherapy (RT) doses for head and neck cancer are population-based, potentially leading to suboptimal outcomes due to patient heterogeneity.
• Current 66-70 Gy RT protocols aim for high tumor control but do not account for individual patient responses.

Purpose of the Study:

• To introduce a framework for personalized RT dose estimation (dynamics-adapted radiotherapy dose, D_DARD) based on early tumor volume changes.
• To evaluate the feasibility and potential impact of D_DARD on head and neck cancer treatment outcomes using an in silico trial.

Main Methods:

• Developed a D_DARD framework using pre- and early on-treatment tumor volume dynamics.
• Conducted an in silico trial with retrospective data from 39 head and neck cancer patients treated with standard RT.
• Performed simulations with unconstrained and constrained D_DARD (54-82 Gy) to assess dose adjustments.

Main Results:

• In silico analysis revealed that 77% of patients were overdosed (average 39 Gy excess) and 23% were underdosed (average 32 Gy deficit) with standard RT.
• Constrained D_DARD simulations suggested a potential improvement in locoregional control by over 10%.
• D_DARD estimates ranged widely from 8 to 186 Gy, highlighting significant inter-patient variability.

Conclusions:

• Early treatment tumor volume dynamics can inform personalized RT dose adjustments for head and neck cancer.
• D_DARD has the potential to de-escalate treatment for the majority of patients while improving overall population-level control rates.
• This approach demonstrates feasibility for dose personalization and stratification for escalation/de-escalation strategies.