Dosimetric and planning efficiency comparison for lung SBRT: CyberKnife vs VMAT vs knowledge-based VMAT

Area of Science:

• Radiation Oncology
• Medical Physics
• Cancer Treatment Technology

Background:

• Lung stereotactic body radiation therapy (SBRT) requires precise treatment planning.
• Comparing different treatment planning systems (TPS) is crucial for optimizing SBRT delivery.
• CyberKnife (CK) and Varian Eclipse are widely used TPS for SBRT.

Purpose of the Study:

• To compare treatment plan quality and planning efficiency for lung SBRT.
• Evaluate CyberKnife (CK) Multiplan versus Varian Eclipse systems (VMAT and KBP-VMAT).
• Assess dosimetric metrics and planning time across different techniques.

Main Methods:

• Retrospective analysis of 13 lung SBRT patients.
• Comparison of CK plans with Eclipse-generated VMAT and knowledge-based VMAT (KBP-VMAT) plans.
• Evaluation of metrics including monitor units, conformity indices, dose heterogeneity, spillage, OAR doses, and planning time.

Main Results:

• All techniques met clinical goals; CK plans used more monitor units (MU) and had less dose homogeneity.
• KBP-VMAT demonstrated superior organ at risk (OAR) sparing compared to VMAT.
• KBP-VMAT offered the shortest planning time, while VMAT achieved comparable plan quality to CK more efficiently.

Conclusions:

• Eclipse-based VMAT provides an efficient alternative to CK for lung SBRT with comparable plan quality.
• KBP-VMAT enhances OAR sparing but may increase MU requirements.
• Further optimization of KBP-VMAT is possible with site-specific models.