Jeremy Booth1, Vincent Caillet2, Adam Briggs3, Nicholas Hardcastle4, Georgios Angelis5, Dasantha Jayamanne6, Meegan Shepherd3, Alexander Podreka3, Kathryn Szymura3, Doan Trang Nguyen7, Per Poulsen8, Ricky O'Brien9, Benjamin Harris10, Carol Haddad3, Thomas Eade6, Paul Keall9. 1. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, Australia; Institute of Medical Physics, School of Physics, University of Sydney, Australia. Electronic address: Jeremy.Booth@health.nsw.gov.au. 2. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, Australia; ACRF Image X Institute, Central Clinical School, University of Sydney, Australia. 3. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, Australia. 4. Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia; Centre for Medical Radiation Physics, University of Wollongong, Australia. 5. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, Australia; Institute of Medical Physics, School of Physics, University of Sydney, Australia. 6. Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, Australia; Northern Clinical School, University of Sydney, Australia. 7. ACRF Image X Institute, Central Clinical School, University of Sydney, Australia; School of Biomedical Engineering, University of Technology Sydney, Australia. 8. Department of Oncology and Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark. 9. ACRF Image X Institute, Central Clinical School, University of Sydney, Australia. 10. Department of Respiratory and Sleep Medicine, Royal North Shore Hospital, Sydney, Australia.
Abstract
BACKGROUND AND PURPOSE: The purpose of this work is to present the clinical experience from the first-in-human trial of real-time tumor targeting via MLC tracking for stereotactic ablative body radiotherapy (SABR) of lung lesions. METHODS AND MATERIALS: Seventeen patients with stage 1 non-small cell lung cancer (NSCLC) or lung metastases were included in a study of electromagnetic transponder-guided MLC tracking for SABR (NCT02514512). Patients had electromagnetic transponders inserted near the tumor. An MLC tracking SABR plan was generated with planning target volume (PTV) expanded 5 mm from the end-exhale gross tumor volume (GTV). A clinically approved comparator plan was generated with PTV expanded 5 mm from a 4DCT-derived internal target volume (ITV). Treatment was delivered using a standard linear accelerator to continuously adapt the MLC based on transponder motion. Treated volumes and reconstructed delivered dose were compared between MLC tracking and comparator ITV-based treatment. RESULTS: All seventeen patients were successfully treated with MLC tracking (70 successful fractions). MLC tracking treatment delivery time averaged 8 minutes. The time from the start of CBCT to the end of treatment averaged 22 minutes. The MLC tracking PTV for 16/17 patients was smaller than the ITV-based PTV (range -1.6% to 44% reduction, or -0.6 to 18 cc). Reductions in mean lung dose (27 cGy) and V20Gy (50 cc) were statistically significant (p < 0.02). Reconstruction of treatment doses confirmed a statistically significant improvement in delivered GTV D98% (p < 0.05) from planned dose compared with the ITV-based plans. CONCLUSION: The first treatments with lung MLC tracking have been successfully performed in seventeen SABR patients. MLC tracking for lung SABR is feasible, efficient and delivers high-precision target dose and lower normal tissue dose.
BACKGROUND AND PURPOSE: The purpose of this work is to present the clinical experience from the first-in-human trial of real-time tumor targeting via MLC tracking for stereotactic ablative body radiotherapy (SABR) of lung lesions. METHODS AND MATERIALS: Seventeen patients with stage 1 non-small cell lung cancer (NSCLC) or lung metastases were included in a study of electromagnetic transponder-guided MLC tracking for SABR (NCT02514512). Patients had electromagnetic transponders inserted near the tumor. An MLC tracking SABR plan was generated with planning target volume (PTV) expanded 5 mm from the end-exhale gross tumor volume (GTV). A clinically approved comparator plan was generated with PTV expanded 5 mm from a 4DCT-derived internal target volume (ITV). Treatment was delivered using a standard linear accelerator to continuously adapt the MLC based on transponder motion. Treated volumes and reconstructed delivered dose were compared between MLC tracking and comparator ITV-based treatment. RESULTS: All seventeen patients were successfully treated with MLC tracking (70 successful fractions). MLC tracking treatment delivery time averaged 8 minutes. The time from the start of CBCT to the end of treatment averaged 22 minutes. The MLC tracking PTV for 16/17 patients was smaller than the ITV-based PTV (range -1.6% to 44% reduction, or -0.6 to 18 cc). Reductions in mean lung dose (27 cGy) and V20Gy (50 cc) were statistically significant (p < 0.02). Reconstruction of treatment doses confirmed a statistically significant improvement in delivered GTV D98% (p < 0.05) from planned dose compared with the ITV-based plans. CONCLUSION: The first treatments with lung MLC tracking have been successfully performed in seventeen SABR patients. MLC tracking for lung SABR is feasible, efficient and delivers high-precision target dose and lower normal tissue dose.
Authors: Hua-Chieh Shao; Jing Wang; Ti Bai; Jaehee Chun; Justin C Park; Steve Jiang; You Zhang Journal: Phys Med Biol Date: 2022-05-24 Impact factor: 4.174
Authors: Sarah Hegarty; Nicholas Hardcastle; James Korte; Tomas Kron; Sarah Everitt; Sulman Rahim; Fiona Hegi-Johnson; Rick Franich Journal: Front Oncol Date: 2022-03-03 Impact factor: 6.244