Characterization and clinical evaluation of a novel 2D detector array for conventional and flattening filter free (FFF) IMRT pre-treatment verification
| Autor: | Dwi Seno Kuncoro Sihono, Yuvaraj Sekar, Johannes Thoelking, Frank Lohr, Miriam Eckl, Hansjoerg Wertz, Frederik Wenz, Irakli Kalichava |
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| Rok vydání: | 2018 |
| Předmět: |
Male
Pre treatment Flattening filter free (FFF) Biophysics 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Optics Nuclear Medicine and Imaging Humans Dosimetry Radiology Nuclear Medicine and imaging IMRT-plan verification Detector array Radiometry Physics Radiological and Ultrasound Technology Pixel business.industry Radiotherapy Planning Computer-Assisted Detector Prostatic Neoplasms Radiotherapy Dosage 2D detector array Quality assurance Radiology Nuclear Medicine and Imaging 030220 oncology & carcinogenesis Calibration Ionization chamber Radiotherapy Intensity-Modulated Radiology Nuclear medicine business Clinical evaluation |
| Zdroj: | Zeitschrift für Medizinische Physik. 28:134-141 |
| ISSN: | 0939-3889 |
| DOI: | 10.1016/j.zemedi.2017.08.003 |
| Popis: | Background and purpose The novel MatriXXFFF (IBA Dosimetry , Germany) detector is a new 2D ionization chamber detector array designed for patient specific IMRT-plan verification including flattening-filter-free (FFF) beams. This study provides a detailed analysis of the characterization and clinical evaluation of the new detector array. Material and methods The verification of the MatriXXFFF was subdivided into (i) physical dosimetric tests including dose linearity, dose rate dependency and output factor measurements and (ii) patient specific IMRT pre-treatment plan verifications. The MatriXX FFF measurements were compared to the calculated dose distribution of a commissioned treatment planning system by gamma index and dose difference evaluations for 18 IMRT-sequences. All IMRT-sequences were measured with original gantry angles and with collapsing all beams to 0° gantry angle to exclude the influence of the detector's angle dependency. Results The MatriXXFFF was found to be linear and dose rate independent for all investigated modalities (deviations ≤0.6%). Furthermore, the output measurements of the MatriXXFFF were in very good agreement to reference measurements (deviations ≤1.8%). For the clinical evaluation an average pixel passing rate for γ(3%,3 mm) of (98.5 ± 1.5)% was achieved when applying a gantry angle correction. Also, with collapsing all beams to 0° gantry angle an excellent agreement to the calculated dose distribution was observed (γ(3%,3 mm) = (99.1 ± 1.1)%). Conclusions The MatriXXFFF fulfills all physical requirements in terms of dosimetric accuracy. Furthermore, the evaluation of the IMRT-plan measurements showed that the detector particularly together with the gantry angle correction is a reliable device for IMRT-plan verification including FFF. |
| Databáze: | OpenAIRE |
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