Knowledge based automated planning for non-coplanar VMAT stereotactic radiosurgery in ocular malignancies

Area of Science:

• Radiation Oncology
• Medical Physics
• Ophthalmology

Background:

• Stereotactic radiosurgery/radiotherapy (SRS/SRT) is a less invasive treatment for ocular malignancies.
• SRS/SRT planning is complex, time-consuming, and planner-dependent.
• Improving planning efficiency, consistency, and quality is crucial.

Purpose of the Study:

• To demonstrate the efficacy of RapidPlan modeling combined with HyperArc for ocular SRS/SRT.
• To evaluate improvements in planning efficiency, consistency, and quality.
• To compare model-based planning with manual planning for ocular diseases.

Main Methods:

• Developed and trained a HyperArc-based RapidPlan (HARP) model on 80 ocular malignancy datasets.
• Compared HARP model-based plans with manually generated plans for 20 test datasets.
• Utilized Eclipse V16 with Acuros XB, TrueBeam LINAC, and Millennium 120 MLCs for planning.
• Performed EPID-based patient-specific QA and Monte Carlo (MC) second-check.

Main Results:

• HARP model-based plans showed comparable target coverage and conformality to manual plans.
• Significant improvements in organ-at-risk (OAR) sparing were observed (e.g., optic nerve, lens, lacrimal gland).
• Planning time reduced from ~120 minutes to ~15 minutes; modulation factor, monitor units, and beam-on times decreased.
• Patient-specific QA and MC second-check results improved with HARP model-based plans.

Conclusions:

• RapidPlan-generated ocular SRS plans match or exceed manual plan quality.
• Significant reduction in planning time was achieved without compromising plan quality.
• The HARP model demonstrates a promising advancement for ocular SRS/SRT planning and treatment.