BACKGROUND AND PURPOSE: Patients were treated at our institute for single and multiple lymph node oligometastases on the 1.5T MR-linac since August 2018. The superior soft-tissue contrast and additional software features of the MR-linac compared to CBCT-linacs allow for online adaptive treatment planning. The purpose of this study was to perform a target coverage and dose criteria based evaluation of the clinically delivered online adaptive radiotherapy treatment compared with conventional CBCT-linac treatment. MATERIALS AND METHODS: Patient data was used from 14 patients with single lymph node oligometastases and 6 patients with multiple (2-3) metastases. All patients were treated on the 1.5T MR-linac with a prescribed dose of 5 × 7 Gy to 95% of the PTV and a CBCT-linac plan was created for each patient. The difference in target coverage between these plans was compared and plans were evaluated based on dose criteria for each fraction after calculating the CBCT-plan on the daily anatomy. The GTV coverage was evaluated based on the online planning and the post-delivery MRI. RESULTS: For both single and multiple lymph node oligometastases the GTV V35Gy had a median value of 100% for both the MR-linac plans and CBCT-plans pre- and post-delivery and did not significantly differ. The percentage of plans that met all dose constraints was improved from 19% to 84% and 20% to 67% for single and multiple lymph node cases, respectively. CONCLUSION: Target coverage and dose criteria based evaluation of the first clinical 1.5T MR-linac SBRT treatments of lymph node oligometastases compared with conventional CBCT-linac treatment shows a smaller amount of unplanned violations of high dose criteria. The GTV coverage was comparable. Benefit is primarily gained in patients treated for multiple lymph node oligometastases: geometrical deformations are accounted for, dose can be delivered in one plan and margins can be reduced.
BACKGROUND AND PURPOSE:Patients were treated at our institute for single and multiple lymph node oligometastases on the 1.5T MR-linac since August 2018. The superior soft-tissue contrast and additional software features of the MR-linac compared to CBCT-linacs allow for online adaptive treatment planning. The purpose of this study was to perform a target coverage and dose criteria based evaluation of the clinically delivered online adaptive radiotherapy treatment compared with conventional CBCT-linac treatment. MATERIALS AND METHODS:Patient data was used from 14 patients with single lymph node oligometastases and 6 patients with multiple (2-3) metastases. All patients were treated on the 1.5T MR-linac with a prescribed dose of 5 × 7 Gy to 95% of the PTV and a CBCT-linac plan was created for each patient. The difference in target coverage between these plans was compared and plans were evaluated based on dose criteria for each fraction after calculating the CBCT-plan on the daily anatomy. The GTV coverage was evaluated based on the online planning and the post-delivery MRI. RESULTS: For both single and multiple lymph node oligometastases the GTV V35Gy had a median value of 100% for both the MR-linac plans and CBCT-plans pre- and post-delivery and did not significantly differ. The percentage of plans that met all dose constraints was improved from 19% to 84% and 20% to 67% for single and multiple lymph node cases, respectively. CONCLUSION: Target coverage and dose criteria based evaluation of the first clinical 1.5T MR-linac SBRT treatments of lymph node oligometastases compared with conventional CBCT-linac treatment shows a smaller amount of unplanned violations of high dose criteria. The GTV coverage was comparable. Benefit is primarily gained in patients treated for multiple lymph node oligometastases: geometrical deformations are accounted for, dose can be delivered in one plan and margins can be reduced.
Authors: Anita M Werensteijn-Honingh; Petra S Kroon; Dennis Winkel; J Carlijn van Gaal; Jochem Hes; Louk M W Snoeren; Jaleesa K Timmer; Christiaan C P Mout; Gijsbert H Bol; Alexis N Kotte; Wietse S C Eppinga; Martijn Intven; Bas W Raaymakers; Ina M Jürgenliemk-Schulz Journal: Phys Imaging Radiat Oncol Date: 2022-06-30
Authors: Paul J Keall; Caterina Brighi; Carri Glide-Hurst; Gary Liney; Paul Z Y Liu; Suzanne Lydiard; Chiara Paganelli; Trang Pham; Shanshan Shan; Alison C Tree; Uulke A van der Heide; David E J Waddington; Brendan Whelan Journal: Nat Rev Clin Oncol Date: 2022-04-19 Impact factor: 65.011
Authors: Fabian Weykamp; Charlotte Herder-Wagner; Sebastian Regnery; Philipp Hoegen; C Katharina Renkamp; Jakob Liermann; Carolin Rippke; Stefan A Koerber; Laila König; Carolin Buchele; Sebastian Klüter; Jürgen Debus; Juliane Hörner-Rieber Journal: Strahlenther Onkol Date: 2021-09-01 Impact factor: 3.621
Authors: Petr Burkon; Iveta Selingerova; Marek Slavik; Petr Pospisil; Lukas Bobek; Libor Kominek; Pavel Osmera; Tomas Prochazka; Miroslav Vrzal; Tomas Kazda; Pavel Slampa Journal: Front Oncol Date: 2021-02-05 Impact factor: 6.244
Authors: Enrica Seravalli; Petra S Kroon; John M Buatti; Matthew D Hall; Henry C Mandeville; Karen J Marcus; Cem Onal; Enis Ozyar; Arnold C Paulino; Frank Paulsen; Daniel Saunders; Derek S Tsang; Suzanne L Wolden; Geert O Janssens Journal: Clin Transl Radiat Oncol Date: 2021-06-04