Oliver Blanck1, Laura Masi2, Mark K H Chan3, Sebastian Adamczyk4, Christian Albrecht5, Marie-Christin Damme6, Britta Loutfi-Krauss7, Manfred Alraun5, Roman Fehr8, Ulla Ramm7, Frank-Andre Siebert9, Tenzin Sonam Stelljes10, Daniela Poppinga10, Björn Poppe10. 1. Universitätsklinikum Schleswig-Holstein, Klinik für Strahlentherapie, Kiel, Germany; Saphir Radiochirurgie Zentrum, Frankfurt und Güstrow, Germany. Electronic address: oliver@blanck.de. 2. IFCA, Department of Medical Physics and Radiation Oncology, Firenze, Italy. 3. TuenMun Hospital, Hong Kong, Hong Kong. 4. Greater Poland Cancer Centre, Medical Physics Department, Poznan, Poland; IntraOp Medical Corporation, Sunnyvale, USA. 5. Schwarzwald-Baar-Klinikum, Klinik für Strahlentherapie, Villingen-Schwenningen, Germany. 6. Saphir Radiochirurgie Zentrum, Frankfurt und Güstrow, Germany; Technische Universität Ilmenau, Ilmenau, Germany. 7. Universitätsklinikum Frankfurt am Main, Klinik für Strahlentherapie, Frankfurt, Germany. 8. Universitätsklinikum Rostock, Klinik für Strahlentherapie, Rostock, Germany. 9. Universitätsklinikum Schleswig-Holstein, Klinik für Strahlentherapie, Kiel, Germany. 10. Carl von Ossietzky Universität, Universitätsklinik für Medizinische Strahlenphysik, Campus Pius Hospital, Oldenburg, Germany.
Abstract
PURPOSE: High precision radiosurgery demands comprehensive delivery-quality-assurance techniques. The use of a liquid-filled ion-chamber-array for robotic-radiosurgery delivery-quality-assurance was investigated and validated using several test scenarios and routine patient plans. METHODS AND MATERIAL: Preliminary evaluation consisted of beam profile validation and analysis of source-detector-distance and beam-incidence-angle response dependence. The delivery-quality-assurance analysis is performed in four steps: (1) Array-to-plan registration, (2) Evaluation with standard Gamma-Index criteria (local-dose-difference⩽2%, distance-to-agreement⩽2mm, pass-rate⩾90%), (3) Dose profile alignment and dose distribution shift until maximum pass-rate is found, and (4) Final evaluation with 1mm distance-to-agreement criterion. Test scenarios consisted of intended phantom misalignments, dose miscalibrations, and undelivered Monitor Units. Preliminary method validation was performed on 55 clinical plans in five institutions. RESULTS: The 1000SRS profile measurements showed sufficient agreement compared with a microDiamond detector for all collimator sizes. The relative response changes can be up to 2.2% per 10cm source-detector-distance change, but remains within 1% for the clinically relevant source-detector-distance range. Planned and measured dose under different beam-incidence-angles showed deviations below 1% for angles between 0° and 80°. Small-intended errors were detected by 1mm distance-to-agreement criterion while 2mm criteria failed to reveal some of these deviations. All analyzed delivery-quality-assurance clinical patient plans were within our tight tolerance criteria. CONCLUSION: We demonstrated that a high-resolution liquid-filled ion-chamber-array can be suitable for robotic radiosurgery delivery-quality-assurance and that small errors can be detected with tight distance-to-agreement criterion. Further improvement may come from beam specific correction for incidence angle and source-detector-distance response.
PURPOSE: High precision radiosurgery demands comprehensive delivery-quality-assurance techniques. The use of a liquid-filled ion-chamber-array for robotic-radiosurgery delivery-quality-assurance was investigated and validated using several test scenarios and routine patient plans. METHODS AND MATERIAL: Preliminary evaluation consisted of beam profile validation and analysis of source-detector-distance and beam-incidence-angle response dependence. The delivery-quality-assurance analysis is performed in four steps: (1) Array-to-plan registration, (2) Evaluation with standard Gamma-Index criteria (local-dose-difference⩽2%, distance-to-agreement⩽2mm, pass-rate⩾90%), (3) Dose profile alignment and dose distribution shift until maximum pass-rate is found, and (4) Final evaluation with 1mm distance-to-agreement criterion. Test scenarios consisted of intended phantom misalignments, dose miscalibrations, and undelivered Monitor Units. Preliminary method validation was performed on 55 clinical plans in five institutions. RESULTS: The 1000SRS profile measurements showed sufficient agreement compared with a microDiamond detector for all collimator sizes. The relative response changes can be up to 2.2% per 10cm source-detector-distance change, but remains within 1% for the clinically relevant source-detector-distance range. Planned and measured dose under different beam-incidence-angles showed deviations below 1% for angles between 0° and 80°. Small-intended errors were detected by 1mm distance-to-agreement criterion while 2mm criteria failed to reveal some of these deviations. All analyzed delivery-quality-assurance clinical patient plans were within our tight tolerance criteria. CONCLUSION: We demonstrated that a high-resolution liquid-filled ion-chamber-array can be suitable for robotic radiosurgery delivery-quality-assurance and that small errors can be detected with tight distance-to-agreement criterion. Further improvement may come from beam specific correction for incidence angle and source-detector-distance response.
Authors: Kananan Utitsarn; Giordano Biasi; Nauljun Stansook; Ziyad A Alrowaili; Marco Petasecca; Martin Carolan; Vladimir L Perevertaylo; Wolfgang A Tomé; Tomas Kron; Michael L F Lerch; Anatoly B Rosenfeld Journal: J Appl Clin Med Phys Date: 2019-10-14 Impact factor: 2.102
Authors: Giordano Biasi; Marco Petasecca; Susanna Guatelli; Ebert A Martin; Garry Grogan; Benjamin Hug; Jonathan Lane; Vladimir Perevertaylo; Tomas Kron; Anatoly B Rosenfeld Journal: J Appl Clin Med Phys Date: 2018-07-12 Impact factor: 2.102