Respiratory motion correction in prostate cancer positron emission tomography: A study on patients and phantom simulation

Introduction: To investigate the effects of breathing cycle and tree diaphragm motions on prostate cancer tumors standard uptake value (SUV) during positron emission tomography (PET) and to correct it. Materials and methods: Respiratory motion traces were simulated on the common patient breathing cycle and tree diaphragm motions using the 4D NCAT phantom. Lesions with different activities and diameters were simulated in prostate. This study was conducted in two phases. In the first phase; the generated PET sinograms taken from GATE (Geant4 Application Tomography Emission) Monte Carlo simulations corrected using computed tomography attenuation correction involving the cycle. In the next phase; on the obtained images, the motion-correction was carried out using software for Tomographic Image Reconstruction (STIR). By considering respiration- averaged computed as a true value, the SUVs were measured and analyzed for different motions. Results: In uncorrected measurements, the mean, minimum and maximum SUVs were 0.4%, 0.09% and 2% respectively, whilst in corrected measurements, these value were reported as 3.5%, 0.7% and 14% respectively. Conclusion: The respiratory motion-induced errors in tumor quantification and delineation. The SUVs depending on the phase of the raspatory. Motion correction could enhance the SUVs in prostate cancer PET.