Oleg N Vassiliev1, Christine B Peterson2, Joe Y Chang3, Radhe Mohan1. 1. Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. 2. Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. 3. Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Abstract
Aim: To investigate the extent to which lung stereotactic body radiotherapy (SBRT) treatment plans can be improved by replacing conventional flattening filter (FF) beams with flattening filter-free (FFF) beams. Material and Methods: We selected 15 patients who had received SBRT with conventional 6-MV photon beams for early-stage lung cancer. We imported the patients' treatment plans into the Eclipse 13.6 treatment planning system, in which we configured the AAA dose calculation model using representative beam data for a TrueBeam accelerator operated in 6-MV FFF mode. We then created new treatment plans by replacing the conventional FF beams in the original plans with FFF beams. Results: The FFF plans had better target coverage than the original FF plans did. For the planning target volume, FFF plans significantly improved the D98, D95, D90, homogeneity index, and uncomplicated tumor control probability. In most cases, the doses to organs at risk were lower in FFF plans. FFF plans significantly reduced the mean lung dose, V10, V20, V30, and normal tissue complication probability for the total lung and improved the dosimetric indices for the ipsilateral lung. For most patients, FFF beams achieved lower maximum doses to the esophagus, heart, and the spinal cord; and a lower chest wall V30. Findings: Compared with FF beams, FFF beams achieved lower doses to organs at risk, especially the lung, without compromising tumor coverage; in fact, FFF beams improved coverage in most cases. Thus, replacing FF beams with FFF beams can achieve a better therapeutic ratio.
Aim: To investigate the extent to which lung stereotactic body radiotherapy (SBRT) treatment plans can be improved by replacing conventional flattening filter (FF) beams with flattening filter-free (FFF) beams. Material and Methods: We selected 15 patients who had received SBRT with conventional 6-MV photon beams for early-stage lung cancer. We imported the patients' treatment plans into the Eclipse 13.6 treatment planning system, in which we configured the AAA dose calculation model using representative beam data for a TrueBeam accelerator operated in 6-MV FFF mode. We then created new treatment plans by replacing the conventional FF beams in the original plans with FFF beams. Results: The FFF plans had better target coverage than the original FF plans did. For the planning target volume, FFF plans significantly improved the D98, D95, D90, homogeneity index, and uncomplicated tumor control probability. In most cases, the doses to organs at risk were lower in FFF plans. FFF plans significantly reduced the mean lung dose, V10, V20, V30, and normal tissue complication probability for the total lung and improved the dosimetric indices for the ipsilateral lung. For most patients, FFF beams achieved lower maximum doses to the esophagus, heart, and the spinal cord; and a lower chest wall V30. Findings: Compared with FF beams, FFF beams achieved lower doses to organs at risk, especially the lung, without compromising tumor coverage; in fact, FFF beams improved coverage in most cases. Thus, replacing FF beams with FFF beams can achieve a better therapeutic ratio.
Authors: Geoff Budgell; Kirstie Brown; Jason Cashmore; Simon Duane; John Frame; Mark Hardy; David Paynter; Russell Thomas Journal: Phys Med Biol Date: 2016-11-07 Impact factor: 3.609
Authors: Oleg N Vassiliev; Stephen F Kry; He C Wang; Christine B Peterson; Joe Y Chang; Radhe Mohan Journal: Phys Med Biol Date: 2018-09-28 Impact factor: 3.609
Authors: Brendan M Prendergast; John B Fiveash; Richard A Popple; Grant M Clark; Evan M Thomas; Douglas J Minnich; Rojymon Jacob; Sharon A Spencer; James A Bonner; Michael C Dobelbower Journal: J Appl Clin Med Phys Date: 2013-05-06 Impact factor: 2.102
Authors: Ying Xiao; Stephen F Kry; Richard Popple; Ellen Yorke; Niko Papanikolaou; Sotirios Stathakis; Ping Xia; Saiful Huq; John Bayouth; James Galvin; Fang-Fang Yin Journal: J Appl Clin Med Phys Date: 2015-05-08 Impact factor: 2.102
Authors: Oleg N Vassiliev; Stephen F Kry; Joe Y Chang; Peter A Balter; Uwe Titt; Radhe Mohan Journal: J Appl Clin Med Phys Date: 2009-01-27 Impact factor: 2.102