Clinical Implementation and Dosimetric Evaluation of a Robust Proton Lattice Planning Strategy Using Primary and...

Area of Science:

• Radiation Oncology
• Medical Physics
• Cancer Therapy

Background:

• Pencil-beam scanning proton therapy is a potential modality for lattice therapy.
• Existing lattice therapy methods face challenges in plan quality and robustness.
• Multifield approaches are needed for improved clinical solutions.

Purpose of the Study:

• To propose and evaluate a practical and robust proton lattice (RPL) planning method.
• To compare the dosimetric characteristics of RPL plans with photon lattice plans.
• To assess the clinical feasibility of the RPL technique.

Main Methods:

• A novel RPL planning technique using two orthogonal beams (primary and robust complementary) was developed.
• The technique was evaluated on seven cases previously treated with photon lattice therapy.
• Dosimetric parameters including vertex count, volume, peak-to-valley dose ratios (PVDRs), and low-dose volumes were compared.

Main Results:

• The RPL strategy achieved clinical planning goals, increasing the average number of vertices by 30% and vertex volume by 49%.
• RPL plans demonstrated significantly higher PVDRs (10.5 ± 4.8 vs 2.5 ± 0.9, P < .005) compared to photon plans.
• RPL plans resulted in more conformal doses with less low dose to the gross target volume (GTV).

Conclusions:

• A novel RPL planning strategy using orthogonal beams was successfully developed and translated to clinical practice.
• The RPL method generates higher quality plans with more vertices and improved PVDRs.
• This proton therapy approach offers a superior alternative to current photon lattice plans.