Abstract
Keywords
Introduction
Methods
- I.Clinical field-based planning: To determine the effect of removing bolus for practitioners that clinically define field borders. Plans with bolus were generated with this approach and used to treat patients in the clinic. For the study, the bolus was digitally removed, and dose was recalculated. This subset of treatment plans was deliberately not re-optimized because field-based planning does not use a target volume for optimization and dose evaluation.
- II.Volume-based planning: To determine the effect of removing bolus for practitioners that define breast target volumes to be used in treatment planning with optimization to meet dose constraints. The chest wall was contoured by a radiation oncologist and new treatment plans were generated both with and without bolus, where target coverage was deliberately planned for and assessed using dose-volume histogram metrics.
- III.Variability in clinically reported dose: To report the difference in the treatment planning calculated dosimetry to skin and subcutaneous tissue, volume-based plans were recalculated using two commercially available calculation algorithms: Acuros XB (AXB) algorithm (Varian Medical Systems, Palo Alto, CA) and the Anisotropic Analytical Algorithm (AAA) algorithm (Varian Medical Systems, Palo Alto, CA). In 2010, the AXB algorithm was developed to address the limitations of AAA algorithm in superficial regions and areas of inhomogeneities.10.,11.,12.,13.,14.Therefore, the AXB algorithm provides a more accurate estimate of dose deposited in superficial tissue and may be used to inform clinicians of the superficial dose changes with the removal of daily bolus for treatment.

Study common parameters
Patient demographics
Treatment planning techniques
Hypofractionated LocoRegional Radiotherapy in Breast Cancer (RHEAL) 2020. Available at: https://www.clinicaltrials.gov/ct2/show/NCT04228991.
Regional Radiotherapy in Biomarker Low-Risk Node Positive and T3N0 Breast Cancer (TAILOR RT) 2018. Available at: https://clinicaltrials.gov/ct2/show/NCT03488693.
Volume definitions
Breast cancer atlas for radiation therapy planning: Consensus definitions 2018. Available at: https://www.nrgoncology.org/Portals/0/ScientificProgram/CIRO/Atlases/BreastCancerAtlas_corr.pdf?ver=2018-04-18-144201-270.
- I.Skin (3 mm): a 3 mm rind, and
- II.Subcutaneous tissue: a 2 mm layer beyond the 3 mm to represent the subcutaneous tissue.2.

Sub-study specific parameters
Clinical field-based planning
Volume-based planning
Variability in clinically reported dose
Results
Patient demographics
Clinical field-based planning

Volume-based planning
Variability in clinically reported dose

Discussion
Conclusion
Author Responsible for Statistical Analysis
Declaration of Competing Interest
Funding
Acknowledgment
Data Availability Statement
- Research data are stored in an institutional repository and will be shared upon request to the corresponding author.
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Article info
Publication history
Footnotes
Written as desired for publication including highest academic degree.