Monica Serban1, Christian Kirisits2, Richard Pötter3, Astrid de Leeuw4, Karen Nkiwane3, Isabelle Dumas5, Nicole Nesvacil3, Jamema Swamidas6, Robert Hudej7, Gerry Lowe8, Taran Paulsen Hellebust9, Geetha Menon10, Arun Oinam11, Peter Bownes12, Bernard Oosterveld13, Marisol De Brabandere14, Kees Koedooder15, Anne Beate Langeland Marthinsen16, Jacob Lindegaard17, Kari Tanderup17. 1. Department of Oncology, Aarhus University Hospital, Denmark; Department of Medical Physics, McGill University Health Center, Montreal, Canada. 2. Department of Radiation Oncology, Comprehensive Cancer Center, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/General Hospital of Vienna, Austria. Electronic address: christian.kirisits@meduniwien.ac.at. 3. Department of Radiation Oncology, Comprehensive Cancer Center, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/General Hospital of Vienna, Austria. 4. Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands. 5. Department of Radiotherapy, Gustave-Roussy, Villejuif, France. 6. Department of Radiation Oncology, Tata Memorial Hospital, Mumbai, India. 7. Department of Radiotherapy, Institute of Oncology Ljubljana, Slovenia. 8. Cancer Centre, Mount Vernon Hospital, London, UK. 9. Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Norway. 10. Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Canada. 11. Department of Radiotherapy and Oncology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. 12. Leeds Cancer Centre, St James's University Hospital, Leeds, UK. 13. Radiotherapiegroep, Arnhem, The Netherlands. 14. Department of Radiation Oncology, UZ Leuven, Belgium. 15. Department of Radiation Oncology Academic Medical Center, University of Amsterdam, The Netherlands. 16. Department of Radiotherapy, Cancer Clinic, St. Olavs Hospital, Norway; Department of Physics, NTNU, Trondheim, Norway. 17. Department of Oncology, Aarhus University Hospital, Denmark.
Abstract
PURPOSE: To investigate the isodose surface volumes (ISVs) for 85, 75 and 60 Gy EQD2 for locally advanced cervix cancer patients. MATERIALS AND METHODS: 1201 patients accrued in the EMBRACE I study were analysed. External beam radiotherapy (EBRT) with concomitant chemotherapy was followed by MR based image-guided adaptive brachytherapy (MR-IGABT). ISVs were calculated using a predictive model based on Total Reference Air Kerma and compared to Point A-standard loading systems. Influence of fractionation schemes and dose rates was evaluated through comparison of ISVs for α/β 10 Gy and 3 Gy. RESULTS: Median V85 Gy, V75 Gy and V60 Gy EQD210 were 72 cm3, 100 cm3 and 233 cm3, respectively. Median V85 Gy EQD210 was 23% smaller than in standard 85 Gy prescription to Point A. For small (<25 cm3), intermediate (25-35 cm3) and large (>35 cm3) CTVHR volumes, the V85 Gy was 57 cm3, 70 cm3 and 89 cm3, respectively. In 38% of EMBRACE patients the V85 Gy was similar to standard plans with 75-85 Gy to Point A. 41% of patients had V85 Gy smaller than standard plans receiving 75 Gy at Point A, while 21% of patients had V85 Gy larger than standard plans receiving 85 Gy at Point A. CONCLUSIONS: MR-IGABT and individualized dose prescription during EMBRACE I resulted in improved target dose coverage and decreased ISVs compared to standard plans used with classical Point A based brachytherapy. The ISVs depended strongly on CTVHR volume which demonstrates that dose adaptation was performed per individual tumour size and response during EBRT.
PURPOSE: To investigate the isodose surface volumes (ISVs) for 85, 75 and 60 Gy EQD2 for locally advanced cervix cancerpatients. MATERIALS AND METHODS: 1201 patients accrued in the EMBRACE I study were analysed. External beam radiotherapy (EBRT) with concomitant chemotherapy was followed by MR based image-guided adaptive brachytherapy (MR-IGABT). ISVs were calculated using a predictive model based on Total Reference Air Kerma and compared to Point A-standard loading systems. Influence of fractionation schemes and dose rates was evaluated through comparison of ISVs for α/β 10 Gy and 3 Gy. RESULTS: Median V85 Gy, V75 Gy and V60 Gy EQD210 were 72 cm3, 100 cm3 and 233 cm3, respectively. Median V85 Gy EQD210 was 23% smaller than in standard 85 Gy prescription to Point A. For small (<25 cm3), intermediate (25-35 cm3) and large (>35 cm3) CTVHR volumes, the V85 Gy was 57 cm3, 70 cm3 and 89 cm3, respectively. In 38% of EMBRACE patients the V85 Gy was similar to standard plans with 75-85 Gy to Point A. 41% of patients had V85 Gy smaller than standard plans receiving 75 Gy at Point A, while 21% of patients had V85 Gy larger than standard plans receiving 85 Gy at Point A. CONCLUSIONS: MR-IGABT and individualized dose prescription during EMBRACE I resulted in improved target dose coverage and decreased ISVs compared to standard plans used with classical Point A based brachytherapy. The ISVs depended strongly on CTVHR volume which demonstrates that dose adaptation was performed per individual tumour size and response during EBRT.
Authors: Vincent Grégoire; Matthias Guckenberger; Karin Haustermans; Jan J W Lagendijk; Cynthia Ménard; Richard Pötter; Ben J Slotman; Kari Tanderup; Daniela Thorwarth; Marcel van Herk; Daniel Zips Journal: Mol Oncol Date: 2020-06-29 Impact factor: 6.603