Dose perturbations from implanted helical gold markers in proton therapy of prostate cancer
| Autor: | Ronald X. Zhu, Wayne D. Newhauser, Annelise Giebeler, Jonas D. Fontenot, G. Ciangaru, Peter A. Balter |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Materials science Proton medicine.medical_treatment Radiography Monte Carlo method and heavier particle dosimetry Article fiducial markers Prostate cancer neutron Prostate medicine Humans Radiation Oncology Physics Radiology Nuclear Medicine and imaging Instrumentation Proton therapy Radiation Phantoms Imaging business.industry Radiotherapy Planning Computer-Assisted Prostatic Neoplasms Radiotherapy Dosage medicine.disease Radiation therapy medicine.anatomical_structure Gold Protons Fiducial marker business Nuclear medicine Algorithms Biomarkers proton |
| Zdroj: | Journal of Applied Clinical Medical Physics |
| ISSN: | 1526-9914 |
| DOI: | 10.1120/jacmp.v10i1.2875 |
| Popis: | Implanted gold fiducial markers are widely used in radiation therapy to improve targeting accuracy. Recent investigations have revealed that metallic fiducial markers can cause severe perturbations in dose distributions for proton therapy, suggesting smaller markers should be considered. The objective of this study was to estimate the dosimetric impact of small gold markers in patients receiving proton therapy for prostate cancer. Small, medium, and large helical wire markers with lengths of 10 mm and helix diameters of 0.35 mm, 0.75 mm, and 1.15 mm, respectively, were implanted in an anthropomorphic phantom. Radiographic visibility was confirmed using a kilovoltage x‐ray imaging system, and dose perturbations were predicted from Monte Carlo simulations and confirmed by measurements. Monte Carlo simulations indicated that size of dose perturbation depended on marker size, orientation, and distance from the beam's end of range. Specifically, the perturbation of proton dose for the lateral‐opposed‐pair treatment technique was 31% for large markers and 23% for medium markers in a typical oblique orientation. Results for perpendicular and parallel orientations were respectively lower and higher. Consequently, these markers are not well suited for use in patients receiving proton therapy for prostate cancer. Dose perturbation was not observed for the small markers, but these markers were deemed too fragile for transrectal implantation in the prostate. PACS number: 87.53.Pb |
| Databáze: | OpenAIRE |
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