Tuomas Koivumäki1, Janne Heikkilä2, Anssi Väänänen2, Kristiina Koskela2, Saara Sillanmäki3, Jan Seppälä2. 1. Cancer Center, Kuopio University Hospital, Finland. Electronic address: tuomas.koivumaki@kuh.fi. 2. Cancer Center, Kuopio University Hospital, Finland. 3. Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Finland.
Abstract
BACKGROUND AND PURPOSE: The use of flattening filter free (FFF) beams has potential to speed up deep-inspiration breath-hold treatments. In this study, the beam-on time and dose characteristics of left-sided breast treatment plans with FFF and flattened beams were evaluated. MATERIAL AND METHODS: Twelve plans were generated for 20 patients. The techniques utilized were volumetric modulated arc therapy with two limited tangential arcs (tVMAT) and tangential intensity modulated radiotherapy with dynamic (dIMRT) as well as step-and-shoot (FinF) dose delivery. Each technique was planned with FFF and flattened beams with 6 and 10MV photons. All plans were irradiated and the beam-on times were measured. Dose characteristics of planning target volume (PTV) and organs at risk (OAR) were evaluated. RESULTS: The mean beam-on times were reduced by 18-39% using FFF. Mean PTV dose coverage was least reduced with tVMAT (0.6-0.8%) compared to dIMRT (4%) and FinF (5.6-9.1%), when FFF beams were used instead of flattened beams. Only small differences were observed in OAR doses between equivalent plans (FFF vs. flattened). CONCLUSIONS: A significant reduction was observed in beam-on time when utilizing FFF beams with tVMAT, dIMRT and FinF. tVMAT was the only technique for which the use of FFF did not degrade the treatment plan dose distributions.
BACKGROUND AND PURPOSE: The use of flattening filter free (FFF) beams has potential to speed up deep-inspiration breath-hold treatments. In this study, the beam-on time and dose characteristics of left-sided breast treatment plans with FFF and flattened beams were evaluated. MATERIAL AND METHODS: Twelve plans were generated for 20 patients. The techniques utilized were volumetric modulated arc therapy with two limited tangential arcs (tVMAT) and tangential intensity modulated radiotherapy with dynamic (dIMRT) as well as step-and-shoot (FinF) dose delivery. Each technique was planned with FFF and flattened beams with 6 and 10MV photons. All plans were irradiated and the beam-on times were measured. Dose characteristics of planning target volume (PTV) and organs at risk (OAR) were evaluated. RESULTS: The mean beam-on times were reduced by 18-39% using FFF. Mean PTV dose coverage was least reduced with tVMAT (0.6-0.8%) compared to dIMRT (4%) and FinF (5.6-9.1%), when FFF beams were used instead of flattened beams. Only small differences were observed in OAR doses between equivalent plans (FFF vs. flattened). CONCLUSIONS: A significant reduction was observed in beam-on time when utilizing FFF beams with tVMAT, dIMRT and FinF. tVMAT was the only technique for which the use of FFF did not degrade the treatment plan dose distributions.
Authors: Vincent Vakaet; Hans Van Hulle; Max Schoepen; Els Van Caelenberg; Annick Van Greveling; Jeroen Holvoet; Chris Monten; Luc De Baerdemaeker; Wilfried De Neve; Marc Coppens; Liv Veldeman Journal: Clin Transl Radiat Oncol Date: 2021-02-23
Authors: Sarah B Wisnoskie; Xiaoying Liang; Andrew O Wahl; Nathan R Bennion; Andrew D Granatowicz; Sumin Zhou; Dandan Zheng Journal: J Appl Clin Med Phys Date: 2020-12-03 Impact factor: 2.102