[A Comparison of Tumor Respiratory Motion Evaluation Methods Using Dynamic Thorax Motion Phantom]

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Image Analysis

Background:

• Accurate assessment of tumor respiratory motion is crucial for effective radiation therapy planning.
• Existing methods for evaluating tumor motion have varying degrees of accuracy and time efficiency.
• Dynamic thorax motion phantoms are essential tools for evaluating measurement accuracy and time efficiency.

Purpose of the Study:

• To evaluate the measurement accuracy and time efficiency of different tumor respiratory motion evaluation methods.
• To compare the performance of manual delineation (RTPS [Manual]), automatic delineation (RTPS [Auto]), and dedicated software (Simple 4D).
• To determine the suitability of Simple 4D for clinical tumor respiratory motion analysis.

Main Methods:

• Utilized 12 patterns of 4DCT images from a dynamic thorax motion phantom with varying tumor displacements and artifacts.
• Employed three methods: RTPS (Manual), RTPS (Auto), and Simple 4D software for tumor motion measurement.
• Quantified the differences between phantom motion and measured values for each method.

Main Results:

• In the superior-inferior direction without artifacts, Simple 4D showed a difference of -1.0 mm ± 0.0 mm, comparable to RTPS (Manual) at -0.6 mm ± 0.6 mm.
• RTPS (Auto) exhibited a larger difference of -5.0 mm ± 2.2 mm in the superior-inferior direction.
• All methods achieved differences within 1 mm in the left-right and anterior-posterior directions, with Simple 4D demonstrating shorter analysis time.

Conclusions:

• Simple 4D analysis software provides comparable measurement accuracy to RTPS (Manual) for tumor respiratory motion.
• Simple 4D significantly improves time efficiency compared to RTPS (Manual) and RTPS (Auto).
• The study concludes that Simple 4D is a useful tool for tumor respiratory motion analysis in clinical practice.