[Patient-specific dose verification method using ArcCHECK for total marrow irradiation with intensity modulated arc...

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiotherapy Dosimetry

Background:

• Accurate dose verification is crucial for total marrow irradiation (TMI) to ensure treatment efficacy and minimize toxicity.
• Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT) are advanced techniques used for TMI, each presenting unique dose verification challenges.

Purpose of the Study:

• To investigate and validate patient-specific dose verification methods using the ArcCHECK device for TMI delivered via VMAT and HT.
• To compare the efficacy of different ArcCHECK functionalities for VMAT and HT dose verification.

Main Methods:

• Dose verification was performed using ArcCHECK for head-neck, chest-abdomen, and pelvic regions in 8 patients undergoing TMI.
• For VMAT plans, the ArcCHECK merging function was utilized. For HT plans, a double-plan method (reference and delivery plans) was employed.
• Gamma analysis was used to assess dose passing rates for both VMAT and HT plans.

Main Results:

• VMAT plans achieved high γ-analysis passing rates: 98.9% ± 1.9% (head-neck), 98.4% ± 1.8% (chest-abdomen), and 97.4% ± 2.1% (pelvic).
• HT plans showed acceptable γ-analysis passing rates: 94.3% ± 1.5% (head-neck), 96.5% ± 1.2% (chest-abdomen), and 94.1% ± 1.9% (pelvic).
• The merging function of ArcCHECK proved effective for VMAT TMI dose verification.

Conclusions:

• Patient-specific dose verification using ArcCHECK with its merging function is a reliable method for VMAT-based TMI.
• The double-plan method is suitable for dose verification of HT TMI plans, especially when targets are distant from the setup center.
• These findings support the clinical implementation of ArcCHECK for robust TMI dose verification across different delivery techniques.