title: Automatic planning on hippocampal avoidance whole-brain radiotherapy.
abstract: Mounting evidence suggests that radiation-induced damage to the hippocampus plays a role in neurocognitive decline for patients receiving whole-brain radiotherapy (WBRT). Hippocampal avoidance whole-brain radiotherapy (HA-WBRT) has been proposed to reduce the putative neurocognitive deficits by limiting the dose to the hippocampus. However, urgency of palliation for patients as well as the complexities of the treatment planning may be barriers to protocol enrollment to accumulate further clinical evidence. This warrants expedited quality planning of HA-WBRT. Pinnacle3Automatic treatment planning was designed to increase planning efficiency while maintaining or improving plan quality and consistency. The aim of the present study is to evaluate the performance of the Pinnacle3Auto-Planning on HA-WBRT treatment planning. Ten patients previously treated for brain metastases were selected. Hippocampal volumes were contoured on T1 magnetic resonance (MR) images, and planning target volumes (PTVs) were generated based on RTOG0933. The following 2 types of plans were generated by Pinnacle3Auto-Planning: the one with 2 coplanar volumetric modulated arc therapy (VMAT) arcs and the other with 9-field noncoplanar intensity-modulated radiation therapy (IMRT). D2%and D98%of PTV were used to calculate homogeneity index (HI). HI and Paddick Conformity index (CI) of PTV as well as D100%and Dmaxof the hippocampus were used to evaluate the plan quality. All the auto-plans met the dose coverage and constraint objectives based on RTOG0933. The auto-plans eliminated the necessity of generating pseudostructures by the planners, and it required little manual intervention which expedited the planning process. IMRT quality assurance (QA) results also suggest that all the auto-plans are practically acceptable on delivery. Pinnacle3Auto-Planning generates acceptable plans by RTOG0933 criteria without time-consuming planning process. The expedited quality planning achieved by Auto-Planning (AP) may facilitate protocol enrollment of patients to further investigate the hippocampal-sparing effect and be used to ensure timely start of palliative treatment in future clinical practice.
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE. Electronic address: shuo0220@gmail.com.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Rongtao
authors.initials: R
authors.lastname: Ma
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Bennion
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lei
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Enke
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE.
authors.forename: Sumin
authors.initials: S
authors.lastname: Zhou
mesh_terms: D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000556:secondary; D006624:Hippocampus; D006801:Humans; D007908:Lens, Crystalline; D009900:Optic Nerve; D059351:Organ Sparing Treatments / Q000379:methods*; D058958:Organs at Risk; D011785:Quality Assurance, Health Care; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies
keywords: Auto-planning; Hippocampal avoidance whole-brain radiotherapy