BACKGROUND: The purpose of this study was to determine the feasibility of nondaily image-guided radiotherapy (RT) strategies with intensity-modulated radiotherapy (IMRT) for head and neck cancer. METHODS: Alignment data was analyzed from 103 consecutive patients treated by IMRT for head and neck cancer who had undergone daily imaging with onboard mega-voltage CT (MVCT), resulting in 3275 images. Geometric setup errors that would have occurred using less-than-daily imaging were hypothetically estimated for 4 temporal less-than-daily image-guided RT protocols. RESULTS: For image-guided RT on the first fraction, weekly image-guided RT, first 5 + weekly image-guided RT, and alternating day image-guided RT, the respective incidences of geometric miss were 50.5%, 33.8%, 30.1%, and 15.7% assuming 3-mm uncertainty margins; and 18.7%, 11.7%, 10.3%, and 4.1% with 5-mm margins. CONCLUSION: Less-than-daily image-guided RT strategies result in a high incidence of potential miss when 3-mm uncertainty margins are utilized. Less-than-daily image-guided RT strategies should incorporate margins of at least 5 mm.
BACKGROUND: The purpose of this study was to determine the feasibility of nondaily image-guided radiotherapy (RT) strategies with intensity-modulated radiotherapy (IMRT) for head and neck cancer. METHODS: Alignment data was analyzed from 103 consecutive patients treated by IMRT for head and neck cancer who had undergone daily imaging with onboard mega-voltage CT (MVCT), resulting in 3275 images. Geometric setup errors that would have occurred using less-than-daily imaging were hypothetically estimated for 4 temporal less-than-daily image-guided RT protocols. RESULTS: For image-guided RT on the first fraction, weekly image-guided RT, first 5 + weekly image-guided RT, and alternating day image-guided RT, the respective incidences of geometric miss were 50.5%, 33.8%, 30.1%, and 15.7% assuming 3-mm uncertainty margins; and 18.7%, 11.7%, 10.3%, and 4.1% with 5-mm margins. CONCLUSION: Less-than-daily image-guided RT strategies result in a high incidence of potential miss when 3-mm uncertainty margins are utilized. Less-than-daily image-guided RT strategies should incorporate margins of at least 5 mm.
Authors: Markus Stoll; Eva Maria Stoiber; Sarah Grimm; Jürgen Debus; Rolf Bendl; Kristina Giske Journal: PLoS One Date: 2016-12-29 Impact factor: 3.240
Authors: Daniel Gram; André Haraldsson; N Patrik Brodin; Karsten Nysom; Thomas Björk-Eriksson; Per Munck Af Rosenschöld Journal: Radiat Oncol Date: 2020-06-10 Impact factor: 3.481
Authors: André Haraldsson; Sofie Ceberg; Crister Ceberg; Sven Bäck; Silke Engelholm; Per E Engström Journal: J Appl Clin Med Phys Date: 2020-06-26 Impact factor: 2.102
Authors: Nicholas J Lowther; David A Hamilton; Han Kim; Jamie M Evans; Steven H Marsh; Robert J W Louwe Journal: Phys Imaging Radiat Oncol Date: 2018-12-20