Volumetric-modulated arc therapy using multicriteria optimization for body and extremity sarcoma

Area of Science:

• Radiation Oncology
• Medical Physics
• Cancer Treatment

Background:

• Volumetric-modulated arc therapy (VMAT) with multicriteria optimization (MCO) is a novel technique for radiation therapy planning.
• Evaluating VMAT-MCO in RayStation Treatment Planning System (TPS) is crucial for complex sites like sarcomas.
• Comparison with established intensity-modulated radiation therapy (IMRT) with MCO is needed to assess its clinical utility.

Purpose of the Study:

• To evaluate the implementation and effectiveness of VMAT-MCO in RayStation TPS for extremity and body sarcoma.
• To compare plan quality, organ-at-risk sparing, and treatment efficiency between VMAT-MCO and IMRT-MCO.
• To validate the deliverability and plan quality assurance of VMAT-MCO plans.

Main Methods:

• Ten sarcoma patients previously treated with IMRT-MCO were replanned using VMAT-MCO.
• Plan quality assessed using homogeneity index (HI), conformity index (CI), and organ-at-risk (OAR) dose metrics.
• Treatment efficiency evaluated by monitor units (MU) and net beam-on time; plan quality assurance used Sun Nuclear ArcCHECK phantom with 3%/3 mm gamma criteria.

Main Results:

• No statistically significant differences in PTV HI and CI, or skin dose metrics (D50, Dmean) between VMAT-MCO and IMRT-MCO.
• VMAT-MCO demonstrated general improvements in OAR sparing and statistically significant improvements in treatment efficiency (MU and beam-on time).
• VMAT-MCO plan deliverability was validated with similar gamma passing rates compared to IMRT-MCO.

Conclusions:

• VMAT-MCO is suitable for sarcoma treatment, offering comparable plan quality to IMRT-MCO.
• VMAT-MCO provides significant improvements in treatment efficiency for complex cancer sites.
• This study supports the clinical adoption of VMAT-MCO in advanced radiation therapy planning.