SU-E-J-131: Implement a Passive Breath Gating Equipment for Gated CBCT Imaging: A Feasibility Study

Area of Science:

• Medical Imaging
• Radiotherapy Physics
• Image-guided Interventions

Background:

• Respiratory motion significantly degrades image quality in kilo-voltage cone-beam CT (kVCBCT).
• Motion artifacts complicate accurate tumor targeting in image-guided radiotherapy (IGRT).

Purpose of the Study:

• To evaluate the efficacy of patient passive breath gating (PBG) equipment for kVCBCT acquisition.
• To reduce respiratory-induced motion artifacts in kVCBCT for improved IGRT.

Main Methods:

• A novel PBG system was employed to enable patients to perform breath-holds of 15-25 seconds.
• kVCBCT images were acquired during free breathing (FB) and two breath-hold (BH1, BH2) states.
• Diaphragm position in kVCBCT was compared to a planning CT to assess motion reduction.

Main Results:

• FB kVCBCT showed significant diaphragm motion artifacts, including blurriness and streaks.
• Breath-hold kVCBCT (BH1 and BH2) demonstrated reduced motion artifacts and restored diaphragm edge definition.
• BH1 kVCBCT images exhibited image quality comparable to planning CT, superior to BH2.

Conclusions:

• Patient passive breath gating is a feasible method to mitigate respiratory motion artifacts in kVCBCT.
• Breath-hold kVCBCT enhances image quality for thoracic and abdominal IGRT and adaptive radiotherapy.
• PBG-assisted kVCBCT offers improved precision for radiotherapy treatments.