Virtual Tangential-fields Arc Therapy (ViTAT) for whole breast irradiation: Technique optimization and validation

Area of Science:

• Radiation Oncology
• Medical Physics
• Radiotherapy Techniques

Background:

• Whole breast radiotherapy (WBRT) is a standard treatment for breast cancer.
• Tangential field irradiation is a common technique for WBRT.
• Optimizing radiotherapy plans is crucial for improving treatment efficacy and reducing side effects.

Purpose of the Study:

• To evaluate the performance of a novel volumetric arc technique, Virtual Tangential-fields Arc Therapy (ViTAT).
• To compare ViTAT with conventional tangential field irradiation for whole breast radiotherapy.

Main Methods:

• ViTAT plans utilized four arcs with specific gantry angle distributions mimicking tangential fields.
• Virtual bolus parameters were optimized for plan performance.
• ViTAT plans were optimized and compared to clinical tangential-field plans using DVH parameters for 40 patients.

Main Results:

• ViTAT generated dose distributions comparable to tangential-field plans.
• ViTAT demonstrated significantly improved PTV homogeneity.
• Ipsilateral organs at risk (OARs) showed comparable mean doses, with a slight increase in low-dose spread.
• Contralateral OARs were slightly better spared with ViTAT.

Conclusions:

• ViTAT provides dose distributions similar to conventional tangential-field techniques.
• ViTAT has the potential for automatic treatment plan optimization.
• Further development of knowledge-based DVH prediction models could enhance ViTAT implementation.