TriB-RT: Simultaneous optimization of photon, electron and proton beams.

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Biology

Background:

• Current radiotherapy treatment planning processes often optimize single beam types.
• Integrating multiple beam types (photons, electrons, protons) offers potential for improved dose distribution and target coverage.
• Advanced optimization techniques are needed to harness the benefits of multi-beam approaches.

Purpose of the Study:

• To develop a novel treatment planning process (TPP) for simultaneous optimization of photon, electron, and proton beams.
• To evaluate the quality of treatment plans generated by this novel TPP compared to existing methods.
• To investigate the dosimetric potential of triple beam radiotherapy (TriB-RT) for clinical applications.

Main Methods:

• Developed a framework for fluence map optimization using Monte Carlo (MC) calculated beamlet dose distributions.
• Generated and compared in-house intensity modulated proton therapy (IMPT) plans with commercial treatment planning system (TPS) proton plans.
• Created and analyzed triple beam radiotherapy (TriB-RT) plans for academic and clinically motivated cases, assessing dose contributions and organ-at-risk sparing.

Main Results:

• In-house optimized IMPT plans were found to be equal or superior to TPS-generated proton plans, with MC optimization showing advantages in inhomogeneous scenarios.
• TriB-RT plans demonstrated substantial contributions from all three particle types.
• Clinically motivated cases showed improved sparing of organs at risk (e.g., myelon and brainstem by up to 37%) with TriB-RT compared to IMPT, albeit with a larger low-dose bath.

Conclusions:

• Successfully developed a novel TPP for simultaneous optimization of photon, electron, and proton beams.
• TriB-RT demonstrates potential for improved radiotherapy treatment plan quality.
• TriB-RT is promising for cost-effective single-room proton therapy solutions utilizing a fixed beamline combined with conventional photon and electron beams.