Sparse proportional re-scanning with hadron beams

Area of Science:

• Medical Physics
• Radiation Oncology
• Particle Therapy

Background:

• Hadron therapy utilizes spot scanning for precise dose delivery.
• Current re-scanning techniques ensure uniform dose distribution, especially for moving organs, but increase treatment time.
• Reducing treatment time is a critical area of research in particle therapy.

Purpose of the Study:

• To introduce and evaluate a novel sparse proportional re-scanning technique.
• To quantify the potential reduction in treatment time using this method.
• To assess the applicability of sparse proportional re-scanning for proton and carbon ion therapy.

Main Methods:

• A new technique, sparse proportional re-scanning, was defined.
• This method was applied to 29 proton patient cases (54 fields).
• A reduction factor was introduced and analyzed to quantify time savings.

Main Results:

• Sparse proportional re-scanning reduces the number of scanned spots significantly.
• The reduction factor was found to be dependent on the number of re-scans (N), with values of 2.8 ± 0.3 for N=5 and 3.6 ± 0.4 for N=12.
• The reduction factor was independent of target shape, volume, and layer/grid distances.

Conclusions:

• Sparse proportional re-scanning offers significant advantages in reducing treatment time for hadron therapy.
• The technique is effective for both proton and carbon ion treatments.
• The method shows promise for optimizing volumetric re-scanning protocols.