PURPOSE: To study interfractional organ changes during magnetic resonance (MR)-guided stereotactic ablative radiation therapy for adrenal metastases and to evaluate the dosimetric advantages of online plan adaptation. METHODS AND MATERIALS: Seventeen patients underwent a total of 84 fractions of video-assisted, respiration-gated, MR-guided adaptive radiation therapy to deliver either 50 Gy (5 fractions), 60 Gy (8 fractions), or 24 Gy (3 fractions). An MR scan was repeated before each fraction, followed by rigid coregistration to the gross tumor volume (GTV) on the pretreatment MR scan. Contour deformation, planning target volume (PTV) (GTV + 3 mm) expansion, and online plan reoptimization were then performed. Reoptimized plans were compared with baseline treatment plans recalculated on the anatomy-of-the-day ("predicted plans"). Interfractional changes in organs at risk (OARs) were quantified according to OAR volume changes within a 3 cm distance from the PTV surface, center of mass displacements, and the Dice similarity coefficient. Plan quality evaluation was based on target coverage (GTV and PTV) and high dose sparing of all OARs (V36Gy, V33Gy, and V25Gy). RESULTS: Substantial center of mass displacements were observed for stomach, bowel, and duodenum, 17, 27 and 36 mm, respectively. Maximum volume changes for the stomach, bowel, and duodenum within 3 cm of PTV were 23.8, 20.5, and 20.9 cm3, respectively. Dice similarity coefficient values for OARs ranged from 0.0 to 0.9 for all fractions. Baseline plans recalculated on anatomy-of-the-day revealed underdosage of target volumes and variable OAR sparing, leading to a failure to meet institutional constraints in a third of fractions. Online reoptimization improved target coverage in 63% of fractions and reduced the number of fractions not meeting the V95% objective for GTV and PTV. Reoptimized plans exhibited significantly better sparing of OARs. CONCLUSIONS: Significant interfractional changes in OAR positions were observed despite breath-hold stereotactic ablative radiation therapy delivery under MR-guidance. Online reoptimization of treatment plans led to significant improvements in target coverage and OAR sparing.
PURPOSE: To study interfractional organ changes during magnetic resonance (MR)-guided stereotactic ablative radiation therapy for adrenal metastases and to evaluate the dosimetric advantages of online plan adaptation. METHODS AND MATERIALS: Seventeen patients underwent a total of 84 fractions of video-assisted, respiration-gated, MR-guided adaptive radiation therapy to deliver either 50 Gy (5 fractions), 60 Gy (8 fractions), or 24 Gy (3 fractions). An MR scan was repeated before each fraction, followed by rigid coregistration to the gross tumor volume (GTV) on the pretreatment MR scan. Contour deformation, planning target volume (PTV) (GTV + 3 mm) expansion, and online plan reoptimization were then performed. Reoptimized plans were compared with baseline treatment plans recalculated on the anatomy-of-the-day ("predicted plans"). Interfractional changes in organs at risk (OARs) were quantified according to OAR volume changes within a 3 cm distance from the PTV surface, center of mass displacements, and the Dice similarity coefficient. Plan quality evaluation was based on target coverage (GTV and PTV) and high dose sparing of all OARs (V36Gy, V33Gy, and V25Gy). RESULTS: Substantial center of mass displacements were observed for stomach, bowel, and duodenum, 17, 27 and 36 mm, respectively. Maximum volume changes for the stomach, bowel, and duodenum within 3 cm of PTV were 23.8, 20.5, and 20.9 cm3, respectively. Dice similarity coefficient values for OARs ranged from 0.0 to 0.9 for all fractions. Baseline plans recalculated on anatomy-of-the-day revealed underdosage of target volumes and variable OAR sparing, leading to a failure to meet institutional constraints in a third of fractions. Online reoptimization improved target coverage in 63% of fractions and reduced the number of fractions not meeting the V95% objective for GTV and PTV. Reoptimized plans exhibited significantly better sparing of OARs. CONCLUSIONS: Significant interfractional changes in OAR positions were observed despite breath-hold stereotactic ablative radiation therapy delivery under MR-guidance. Online reoptimization of treatment plans led to significant improvements in target coverage and OAR sparing.
Authors: William A Hall; Eric S Paulson; Uulke A van der Heide; Clifton D Fuller; B W Raaymakers; Jan J W Lagendijk; X Allen Li; David A Jaffray; Laura A Dawson; Beth Erickson; Marcel Verheij; Kevin J Harrington; Arjun Sahgal; Percy Lee; Parag J Parikh; Michael F Bassetti; Clifford G Robinson; Bruce D Minsky; Ananya Choudhury; Robert J H A Tersteeg; Christopher J Schultz Journal: Eur J Cancer Date: 2019-10-12 Impact factor: 9.162
Authors: Sebastian Klüter; Sonja Katayama; C Katharina Spindeldreier; Stefan A Koerber; Gerald Major; Markus Alber; Sati Akbaba; Jürgen Debus; Juliane Hörner-Rieber Journal: Strahlenther Onkol Date: 2020-01-30 Impact factor: 3.621
Authors: Leonard Kim; Stephanie Markovina; Samantha J Van Nest; Subarna Eisaman; Lakshmi Santanam; Julie M Sullivan; Michael Dominello; Michael C Joiner; Jay Burmeister Journal: J Appl Clin Med Phys Date: 2019-05-25 Impact factor: 2.102
Authors: David A Palma; Robert Olson; Stephen Harrow; Rohann J M Correa; Famke Schneiders; Cornelis J A Haasbeek; George B Rodrigues; Michael Lock; Brian P Yaremko; Glenn S Bauman; Belal Ahmad; Devin Schellenberg; Mitchell Liu; Stewart Gaede; Joanna Laba; Liam Mulroy; Sashendra Senthi; Alexander V Louie; Anand Swaminath; Anthony Chalmers; Andrew Warner; Ben J Slotman; Tanja D de Gruijl; Alison Allan; Suresh Senan Journal: BMC Cancer Date: 2019-08-19 Impact factor: 4.430
Authors: Laila König; Matthias F Häfner; Sonja Katayama; Stefan A Koerber; Eric Tonndorf-Martini; Denise Bernhardt; Bastian von Nettelbladt; Fabian Weykamp; Philipp Hoegen; Sebastian Klüter; Matthew S Susko; Jürgen Debus; Juliane Hörner-Rieber Journal: Radiat Oncol Date: 2020-02-04 Impact factor: 3.481
Authors: Danielle S Bitterman; Daniel N Cagney; Lisa L Singer; Paul L Nguyen; Paul J Catalano; Raymond H Mak Journal: J Natl Cancer Inst Date: 2020-03-01 Impact factor: 13.506