SU-E-J-162: Development and Application of Internal and External Motion Tracking System.

Area of Science:

• Biomedical Engineering
• Medical Physics
• Radiological Sciences

Background:

• Accurate tracking of internal organ motion is crucial for effective radiation therapy.
• Respiration-induced organ movement poses challenges for precise tumor targeting.
• Developing non-invasive methods to monitor internal organ motion is essential.

Purpose of the Study:

• To investigate the correlation between internal organ movement and external abdominal surface movement in mini pigs.
• To evaluate the feasibility of using a developed motion tracking system for this correlation.
• To assess the potential for predicting internal target locations based on external movements.

Main Methods:

• A motion tracking system combining C-arm fluoroscopy and surface imaging was developed.
• Internal organ movement was tracked using gold fiducial markers implanted in the diaphragm.
• External abdominal surface movement was captured using a camera and image acquisition board.
• Data acquisition was performed under general anesthesia in mini pigs.

Main Results:

• A strong correlation was observed between internal organ and external abdominal surface movements.
• Correlation coefficients for anterior-posterior (AP) external marker movement versus superior-inferior (SI) and right-left (RL) internal target movement were 0.903 and 0.905, respectively.
• These findings indicate reliable tracking of diaphragm movement via external markers.

Conclusions:

• High correlations confirm the relationship between external marker and diaphragm movements in mini pigs.
• External marker movement can reliably predict internal target locations.
• The developed system shows potential for clinical application in Dynamic Tumor Tracking Radiation Therapy (DTTRT) in animals.