Deformation effect on SUVmax changes in thoracic tumors using 4-D PET/CT scan.

Area of Science:

• Medical Imaging
• Radiology
• Oncology

Background:

• Respiratory motion artifacts degrade PET/CT image quality, affecting Standardized Uptake Value (SUV) measurements.
• Accurate tumor characterization in thoracic cancers requires accounting for respiratory motion.
• 4D PET imaging offers potential for motion-compensated analysis.

Purpose of the Study:

• To investigate thoracic tumor motion using 4D CT.
• To assess the impact of respiratory motion on SUV changes in 4D PET imaging.
• To correlate tumor motion with SUVmax loss in lung and esophageal cancers.

Main Methods:

• Utilized 4D CT and 4D PET imaging across 10 respiratory phases for 12 thoracic cancer patients.
• Applied optical flow method to 4D CT data to quantify maximum tumor displacement during respiration.
• Analyzed the relationship between tumor motion and SUVmax in lung and esophageal tumors.

Main Results:

• Increased tumor motion was significantly associated with SUVmax loss in lung cancer.
• SUVmax loss showed a higher correlation with tumors in the lower lung lobe or lower esophagus.
• Respiratory motion introduces significant deformation effects on SUV measurements.

Conclusions:

• Respiratory motion is a critical factor influencing SUVmax accuracy in thoracic PET/CT.
• Tumor location (lower lung/esophagus) exacerbates SUVmax loss due to motion.
• 4D PET/CT analysis is essential for accurate assessment of thoracic malignancies affected by respiratory motion.