Biological Dose Optimization for Particle Arc Therapy Using Helium and Carbon Ions

Area of Science:

• Medical Physics
• Radiation Oncology
• Particle Therapy

Background:

• Particle arc therapy offers potential advantages over conventional techniques.
• Helium and carbon ions are used in advanced radiation therapy.
• Optimizing dose delivery is crucial for treatment efficacy and safety.

Purpose of the Study:

• To present biological dose optimization for particle arc therapy using helium and carbon ions.
• To evaluate the Spot-Scanning Hadron Arc (SHArc) delivery technique.
• To compare SHArc with conventional treatment planning methods.

Main Methods:

• Developed SHArc optimization for spot-scanning delivery using RayStation and FRoG.
• Applied the algorithm to three patient cases (glioblastoma, prostate adenocarcinoma, skull-base chordoma).
• Evaluated biological dose and dose-averaged Linear Energy Transfer (LETd) against VMAT and 2-field intensity modulated particle therapy.

Main Results:

• SHArc met clinical planning goals for target coverage and OARs.
• Achieved substantial reductions in normal tissue dose (40%-70%) compared to VMAT.
• Increased target LETd significantly with carbon ions (from ~40-60 to ~80-140 keV/µm).

Conclusions:

• SHArc therapy offers benefits including increased normal tissue sparing and enhanced target LETd.
• Potential reduction of high-LET components in organs at risk was observed.
• Further development of SHArc treatment planning is warranted for clinical translation.