Monica Serban1, Christian Kirisits2, Astrid de Leeuw3, Richard Pötter4, Ina Jürgenliemk-Schulz3, Nicole Nesvacil4, Jamema Swamidas5, Robert Hudej6, Gerry Lowe7, Taran Paulsen Hellebust8, Geetha Menon9, Arun Oinam10, Peter Bownes11, Bernard Oosterveld12, Marisol De Brabandere13, Kees Koedooder14, Anne Beate Langeland Marthinsen15, Diane Whitney16, Jacob Lindegaard17, Kari Tanderup17. 1. Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; Department of Medical Physics, McGill University Health Centre, Montreal, Canada. 2. Department of Radiation Oncology, Comprehensive Cancer Centre, Medical University of Vienna/General Hospital of Vienna, Vienna, Austria. Electronic address: christian.kirisits@meduniwien.ac.at. 3. Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands. 4. Department of Radiation Oncology, Comprehensive Cancer Centre, Medical University of Vienna/General Hospital of Vienna, Vienna, Austria. 5. Department of Radiation Oncology, Tata Memorial Hospital, Mumbai, India. 6. Department of Radiotherapy, Institute of Oncology Ljubljana, Slovenia. 7. Cancer Centre, Mount Vernon Hospital, London, United Kingdom. 8. Department of Medical Physics, Oslo University Hospital - The Radium Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway. 9. Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Canada. 10. Department of Radiotherapy and Oncology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. 11. Leeds Cancer Centre, St James's University Hospital, Leeds, United Kingdom. 12. Radiotherapiegroep, Arnhem, The Netherlands. 13. Department of Radiation Oncology, University Hospitals Leuven, Leuven, Belgium. 14. Department of Radiation Oncology Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. 15. Department of Radiotherapy, Cancer Clinic, St. Olavs Hospital, Norway; Department of Physics, NTNU, Trondheim, Norway. 16. Oncology Centre, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, United Kingdom. 17. Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
Abstract
PURPOSE: The aim of this study was to investigate the influence of brachytherapy technique and applicator type on target dose, isodose surface volumes, and organ-at-risk (OAR) dose. METHODS AND MATERIALS: Nine hundred two patients treated with tandem/ovoids (T&O) (n = 299) and tandem/ring (T&R) (n = 603) applicators from 16 EMBRACE centers were analyzed. Patients received external beam radiation therapy and magnetic resonance imaging guided brachytherapy with dose prescription according to departmental practice. Centers were divided into 4 groups, according to applicator/technique: Ovoids and ring centers treating mainly with the intracavitary (IC) technique and ovoids and ring centers treating routinely with the intracavitary/interstitial (IC/IS) technique. V85Gy EQD210, CTVHR D90% (EQD210), and bladder, rectum, sigmoid, and vaginal 5-mm lateral-point doses (EQD23) were evaluated among center groups. Differences between T&O and T&R were tested with multivariable analysis. RESULTS: For similar point A doses, mean CTVHR D90% was 3.3 Gy higher and V85Gy was 23% lower for ring-IC compared with ovoids-IC centers (at median target volumes). Mean bladder/rectum doses (D2cm3 and ICRU-point) were 3.2 to 7.7 Gy smaller and vaginal 5-mm lateral-point was 19.6 Gy higher for ring-IC centers. Routine use of IC/IS technique resulted in increased target dose, whereas V85Gy was stable (T&R) or decreased (T&O); reduced bladder and rectum D2cm3 and bladder ICRU-point by 3.5 to 5.0 Gy for ovoids centers; and similar OAR doses for ring centers. CTVHR D90% was 2.8 Gy higher, bladder D2cm3 4.3 Gy lower, rectovaginal ICRU-point 4.8 Gy lower, and vagina 5-mm lateral-point 22.4 Gy higher for ring-IC/IS versus ovoids-IC/IS centers. The P values were <.002 for all comparisons. Equivalently, significant differences were derived from the multivariable analysis. CONCLUSIONS: T&R-IC applicators have better target dose and dose conformity than T&O-IC in this representative patient cohort. IC applicators fail to cover large target volumes, whereas routine application of IC/IS improves target and OAR dose considerably. Patients treated with T&R show a more favorable therapeutic ratio when evaluating target, bladder/rectum doses, and V85Gy. A comprehensive view on technique/applicators should furthermore include practical considerations and clinical outcome.
PURPOSE: The aim of this study was to investigate the influence of brachytherapy technique and applicator type on target dose, isodose surface volumes, and organ-at-risk (OAR) dose. METHODS AND MATERIALS: Nine hundred two patients treated with tandem/ovoids (T&O) (n = 299) and tandem/ring (T&R) (n = 603) applicators from 16 EMBRACE centers were analyzed. Patients received external beam radiation therapy and magnetic resonance imaging guided brachytherapy with dose prescription according to departmental practice. Centers were divided into 4 groups, according to applicator/technique: Ovoids and ring centers treating mainly with the intracavitary (IC) technique and ovoids and ring centers treating routinely with the intracavitary/interstitial (IC/IS) technique. V85Gy EQD210, CTVHR D90% (EQD210), and bladder, rectum, sigmoid, and vaginal 5-mm lateral-point doses (EQD23) were evaluated among center groups. Differences between T&O and T&R were tested with multivariable analysis. RESULTS: For similar point A doses, mean CTVHR D90% was 3.3 Gy higher and V85Gy was 23% lower for ring-IC compared with ovoids-IC centers (at median target volumes). Mean bladder/rectum doses (D2cm3 and ICRU-point) were 3.2 to 7.7 Gy smaller and vaginal 5-mm lateral-point was 19.6 Gy higher for ring-IC centers. Routine use of IC/IS technique resulted in increased target dose, whereas V85Gy was stable (T&R) or decreased (T&O); reduced bladder and rectum D2cm3 and bladder ICRU-point by 3.5 to 5.0 Gy for ovoids centers; and similar OAR doses for ring centers. CTVHR D90% was 2.8 Gy higher, bladder D2cm3 4.3 Gy lower, rectovaginal ICRU-point 4.8 Gy lower, and vagina 5-mm lateral-point 22.4 Gy higher for ring-IC/IS versus ovoids-IC/IS centers. The P values were <.002 for all comparisons. Equivalently, significant differences were derived from the multivariable analysis. CONCLUSIONS:T&R-IC applicators have better target dose and dose conformity than T&O-IC in this representative patient cohort. IC applicators fail to cover large target volumes, whereas routine application of IC/IS improves target and OAR dose considerably. Patients treated with T&R show a more favorable therapeutic ratio when evaluating target, bladder/rectum doses, and V85Gy. A comprehensive view on technique/applicators should furthermore include practical considerations and clinical outcome.
Authors: Jose Chimeno; Naiara Fuentemilla; Paula Monasor; Francisco Celada; Elena Villafranca; Sílvia Rodriguez; María José Pérez-Calatayud; Santiago Pellejero; Jose Pérez-Calatayud Journal: J Contemp Brachytherapy Date: 2021-12-30
Authors: Hima Bindu Musunuru; Phillip M Pifer; Pranshu Mohindra; Kevin Albuquerque; Sushil Beriwal Journal: Indian J Med Res Date: 2021-08 Impact factor: 5.274