TY - JOUR
T1 - Delivered dose quantification in prostate radiotherapy using online 3D cine imaging and treatment log files on a combined 1.5T magnetic resonance imaging and linear accelerator system
AU - Kontaxis, Charis
AU - de Muinck Keizer, Daan M.
AU - Kerkmeijer, Linda G.W.
AU - Willigenburg, Thomas
AU - den Hartogh, Mariska D.
AU - van der Voort van Zyp, Jochem R.N.
AU - de Groot-van Breugel, Eline N.
AU - Hes, Jochem
AU - Raaymakers, Bas W.
AU - Lagendijk, Jan J.W.
AU - de Boer, Hans C.J.
N1 - Funding Information:
This work received financial support by ZonMw IMDI/LSH-TKI foundation projectnr. 104006004. The authors would like to thank Elekta AB, Stockholm, Sweden for providing some of their research software tools.
Funding Information:
This work received financial support by ZonMw IMDI/LSH-TKI foundation projectnr. 104006004. The authors would like to thank Elekta AB, Stockholm, Sweden for providing some of their research software tools.
Publisher Copyright:
© 2020 The Authors
PY - 2020/7
Y1 - 2020/7
N2 - Background and purpose: Monitoring the intrafraction motion and its impact on the planned dose distribution is of crucial importance in radiotherapy. In this work we quantify the delivered dose for the first prostate patients treated on a combined 1.5T Magnetic Resonance Imaging (MRI) and linear accelerator system in our clinic based on online 3D cine-MR and treatment log files. Materials and methods: A prostate intrafraction motion trace was obtained with a soft-tissue based rigid registration method with six degrees of freedom from 3D cine-MR dynamics with a temporal resolution of 8.5–16.9 s. For each fraction, all dynamics were also registered to the daily MR image used during the online treatment planning, enabling the mapping to this reference point. Moreover, each fraction's treatment log file was used to extract the timestamped machine parameters during delivery and assign it to the appropriate dynamic volume. These partial plans to dynamic volume combinations were calculated and summed to yield the delivered fraction dose. The planned and delivered dose distributions were compared among all patients for a total of 100 fractions. Results: The clinical target volume underwent on average a decrease of 2.2% ± 2.9% in terms of D99% coverage while bladder V62Gy was increased by 1.6% ± 2.3% and rectum V62Gy decreased by 0.2% ± 2.2%. Conclusions: The first MR-linac dose reconstruction results based on prostate tracking from intrafraction 3D cine-MR and treatment log files are presented. Such a pipeline is essential for online adaptation especially as we progress to MRI-guided extremely hypofractionated treatments.
AB - Background and purpose: Monitoring the intrafraction motion and its impact on the planned dose distribution is of crucial importance in radiotherapy. In this work we quantify the delivered dose for the first prostate patients treated on a combined 1.5T Magnetic Resonance Imaging (MRI) and linear accelerator system in our clinic based on online 3D cine-MR and treatment log files. Materials and methods: A prostate intrafraction motion trace was obtained with a soft-tissue based rigid registration method with six degrees of freedom from 3D cine-MR dynamics with a temporal resolution of 8.5–16.9 s. For each fraction, all dynamics were also registered to the daily MR image used during the online treatment planning, enabling the mapping to this reference point. Moreover, each fraction's treatment log file was used to extract the timestamped machine parameters during delivery and assign it to the appropriate dynamic volume. These partial plans to dynamic volume combinations were calculated and summed to yield the delivered fraction dose. The planned and delivered dose distributions were compared among all patients for a total of 100 fractions. Results: The clinical target volume underwent on average a decrease of 2.2% ± 2.9% in terms of D99% coverage while bladder V62Gy was increased by 1.6% ± 2.3% and rectum V62Gy decreased by 0.2% ± 2.2%. Conclusions: The first MR-linac dose reconstruction results based on prostate tracking from intrafraction 3D cine-MR and treatment log files are presented. Such a pipeline is essential for online adaptation especially as we progress to MRI-guided extremely hypofractionated treatments.
KW - Dose accumulation pipeline
KW - Intrafraction cine-MR
KW - MR-linac
KW - Prostate cancer
KW - Soft-tissue motion tracking
KW - Treatment log files
UR - http://www.scopus.com/inward/record.url?scp=85087810197&partnerID=8YFLogxK
U2 - 10.1016/j.phro.2020.06.005
DO - 10.1016/j.phro.2020.06.005
M3 - Article
C2 - 33458322
AN - SCOPUS:85087810197
SN - 2405-6316
VL - 15
SP - 23
EP - 29
JO - Physics and Imaging in Radiation Oncology
JF - Physics and Imaging in Radiation Oncology
ER -