Measurement-based Monte Carlo simulation of high definition dose evaluation for nasopharyngeal cancer patients treated by using intensity modulated radiation therapy |
| |
| Institution: | 1. Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 300, Taiwan;2. Department of Radiation Oncology, Tungs'' Taichung Metroharbor Hospital, Taichung City 435, Taiwan;3. Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan;4. Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan 333, Taiwan;5. Department of Radiation Therapy, Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan 333, Taiwan;6. Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA;1. Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA;2. Department of Orthopedic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA;3. Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas, USA;4. The Comprehensive Neurofibromatosis Clinic, University of Texas Southwestern Medical Center, Dallas, Texas, USA;5. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA;6. Department of Radiology, Peking University Third Hospital, Beijing, China;7. Department of Radiology, Faculty of Medicine, Zagazig University, Zagazig, Egypt;1. Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;2. Universidade Estadual do Rio de Janeiro, Rio de Janeiro, Brazil;3. Comissão Nacional de Energia Nuclear, Rio de Janeiro, Brazil;4. Centro Universitário Estadual da Zona Oeste, Rio de Janeiro, Brazil;1. Resident, Parkland Memorial Hospital, Oral and Maxillofacial Surgery Division, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX;2. Assistant Professor, Oral and Maxillofacial Surgery Division, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX;1. Department of Urology, University of Muenster Medical Center, Muenster, Germany;2. Department of Pathology, University of Muenster Medical Center, Muenster, Germany;3. Department of Urology, University of Ulm, Ulm, Germany;4. Department of Urology, University of Texas Medical Center, Dallas, Texas;5. Department of Urology, M. D. Anderson Cancer Center, Houston, Texas;6. Department of Urology, University of Michigan Cancer Center, Ann Arbor, Michigan;7. Division of Urology, Penn State Health Milton S.Hershey Medical Center, Hershey, Pennsylvania;8. Department of Urology, Medical University Vienna, Vienna, Austria;9. Department of Pathology, Medical University Vienna, Vienna, Austria;10. Department of Pathology, Centre Hospitalier Universitaire de Rennes, Rennes, France;11. Department of Urology, Centre Hospitalier Universitaire de Rennes, Rennes, France;12. Department of Urology, Cochin Hospital, Assistance Publique-Hôpitaux de Paris, Paris Descartes University, Paris, France;13. Department of Uronephrology and Reproductive Health, Sechenov First Moscow State Medical University, Moscow, Russia;14. Department of Urology, Ospedali Riuniti of Bergamo, Bergamo, Italy;1. Department of Industrial and Information Engineering and Economics, University of L’Aquila, Via G. Gronchi n. 18, 67100 L''Aquila, Italy;2. Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX 76019, USA |
| |
| Abstract: | Measurement-based Monte Carlo (MBMC) simulation using a high definition (HD) phantom was used to evaluate the dose distribution in nasopharyngeal cancer (NPC) patients treated with intensity modulated radiation therapy (IMRT). Around nasopharyngeal cavity, there exists many small volume organs-at-risk (OARs) such as the optic nerves, auditory nerves, cochlea, and semicircular canal which necessitate the use of a high definition phantom for accurate and correct dose evaluation. The aim of this research was to study the advantages of using an HD phantom for MBMC simulation in NPC patients treated with IMRT. The MBMC simulation in this study was based on the IMRT treatment plan of three NPC patients generated by the anisotropic analytical algorithm (AAA) of the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA, USA) using a calculation grid of 2 mm2. The NPC tumor was treated to a cumulative dose of 7000 cGy in 35 fractions using the shrinking-field sequential IMRT (SIMRT) method. The BEAMnrc MC Code was used to simulate a Varian EX21 linear accelerator treatment head. The HD phantom contained 0.5 × 0.5 × 1 mm3 voxels for the nasopharyngeal area and 0.5 × 0.5 × 3 mm3 for the rest of the head area. An efficiency map was obtained for the amorphous silicon aS1000 electronic portal imaging device (EPID) to adjust the weighting of each particle in the phase-space file for each IMRT beam. Our analysis revealed that small volume organs such as the eighth cranial nerve, semicircular canal, cochlea and external auditory canal showed an absolute dose difference of ≥200 cGy, while the dose difference for larger organs such as the parotid glands and tumor was negligible for the MBMC simulation using the HD phantom. The HD phantom was found to be suitable for Monte Carlo dose volume analysis of small volume organs. |
| |
| Keywords: | Radiotherapy Monte Carlo Intensity modulated radiation therapy Nasopharyngeal cancer |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
