Defining gross tumor volume using positron emission tomography/computed tomography phantom studies.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Tumor volume and standard uptake value (SUV) measurements from PET/CT scans are prone to inaccuracies.
• Factors such as patient movement, body shape, prostheses, and inherent scanner limitations affect measurement precision.
• Image reconstruction algorithms can also introduce errors in quantitative PET/CT analysis.

Purpose of the Study:

• To investigate the discrepancies in tumor volume and SUV measurements obtained from PET/CT.
• To determine the impact of various factors on the accuracy of quantitative PET/CT parameters.
• To establish a method for calibrating PET/CT measurements for improved accuracy.

Main Methods:

• Quantitative analysis of tumor volume and SUV using a standard phantom (PET Phantom-NEMA IEC/2001).
• Calculation of calibration constants based on phantom measurements.
• Evaluation of the relationship between SUV, tumor diameter, and tumor volume.

Main Results:

• Tumor volume demonstrated complex relationships with SUV and tumor diameter, showing increases and decreases under varying conditions.
• Observed discrepancies between calculated and real values for tumor volume and SUV.
• Identified a need for correction factors to improve the accuracy of PET/CT derived metrics.

Conclusions:

• PET/CT derived tumor volume and SUV require calibration to correct for measurement errors.
• A standardized phantom-based calibration approach can enhance the reliability of quantitative PET/CT data.
• Implementing correction factors is crucial for accurate clinical interpretation of PET/CT findings.