A Collimator Setting Optimization Algorithm for Dual-Arc Volumetric Modulated Arc Therapy in Pancreas Stereotactic Body Radiation Therapy.
Abstract
PURPOSE:To optimize collimator setting to improve dosimetric quality of pancreas volumetric
modulated arc therapy plan for stereotactic body radiation therapy. MATERIALS AND
METHODS:Fifty-five volumetric modulated arc therapy cases in stereotactic body radiation
therapy of pancreas were retrospectively included in this study with internal review
board approval. Different from the routine practice of initializing collimator settings
with a template, the proposed algorithm simultaneously optimizes the collimator angles
and jaw positions that are customized to the patient geometry. Specifically, this
algorithm includes 2 key steps: (1) an iterative optimization algorithm via simulated
annealing that generates a set of potential collimator settings from 39 cases with
pancreas stereotactic body radiation therapy, and (2) a multi-leaf collimator modulation
scoring system that makes the final decision of the optimal collimator settings (collimator
angles and jaw positions) based on organs at risk sparing criteria. For validation,
the other 16 cases with pancreas stereotactic body radiation therapy were analyzed.
Two plans were generated for each validation case, with one plan optimized using the
proposed algorithm (Planopt) and the other plan with the template setting (Planconv).
Each plan was optimized with 2 full arcs and the same set of constraints for the same
case. Dosimetric results were analyzed and compared, including target dose coverage,
conformity, organs at risk maximum dose, and modulation complexity score. All results
were tested by Wilcoxon signed rank tests, and the statistical significance level
was set to .05. RESULTS:Both plan groups had comparable target dose coverage and mean
doses of all organs at risk. However, organs at risk (stomach, duodenum, large/small
bowel) maximum dose sparing (D0.1 cc and D0.03 cc) was improved in Planopt compared
to Planconv. Planopt also showed lower modulation complexity score, which suggests
better capability of handling complex shape and sparing organs at risk . CONCLUSIONS:The
proposed collimator settings optimization algorithm successfully improved dosimetric
performance for dual-arc pancreas volumetric modulated arc therapy plans in stereotactic
body radiation therapy of pancreas. This algorithm has the capability of immediate
clinical application.
Type
Journal articleSubject
HumansPancreatic Neoplasms
Radiosurgery
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted
Retrospective Studies
Algorithms
Radiotherapy, Intensity-Modulated
Organs at Risk
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https://hdl.handle.net/10161/20270Published Version (Please cite this version)
10.1177/1533033819870767Publication Info
Li, Xinyi; Wu, Jackie; Palta, Manisha; Zhang, You; Sheng, Yang; Zhang, Jiahan; & Wang,
Chunhao (2019). A Collimator Setting Optimization Algorithm for Dual-Arc Volumetric Modulated Arc
Therapy in Pancreas Stereotactic Body Radiation Therapy. Technology in cancer research & treatment, 18. pp. 1533033819870767. 10.1177/1533033819870767. Retrieved from https://hdl.handle.net/10161/20270.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Manisha Palta
Associate Professor of Radiation Oncology
Clinical research in gastrointestinal malignancies, lymphomas and breast malignancies.
Chunhao Wang
Assistant Professor of Radiation Oncology
Deep learning methods for image-based radiotherapy outcome prediction and assessment
Machine learning in outcome modelling
Automation in radiotherapy planning and delivery
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