title: An efficient Volumetric Arc Therapy treatment planning approach for hippocampal-avoidance whole-brain radiation therapy (HA-WBRT).
abstract: An efficient and simple class solution is proposed for hippocampal-avoidance whole-brain radiation therapy (HA-WBRT) planning using the Volumetric Arc Therapy (VMAT) delivery technique following the NRG Oncology protocol NRG-CC001 treatment planning guidelines. The whole-brain planning target volume (PTV) was subdivided into subplanning volumes that lie in plane and out of plane with the hippocampal-avoidance volume. To further improve VMAT treatment plans, a partial-field dual-arc technique was developed. Both the arcs were allowed to overlap on the in-plane subtarget volume, and in addition, one arc covered the superior out-of-plane sub-PTV, while the other covered the inferior out-of-plane subtarget volume. For all plans (n = 20), the NRG-CC001 protocol dose-volume criteria were met. Mean values of volumes for the hippocampus and the hippocampal-avoidance volume were 4.1 cm(3) ± 1.0 cm(3) and 28.52 cm(3) ± 3.22 cm(3), respectively. For the PTV, the average values of D(2%) and D(98%) were 36.1 Gy ± 0.8 Gy and 26.2 Gy ± 0.6 Gy, respectively. The hippocampus D(100%) mean value was 8.5 Gy ± 0.2 Gy and the maximum dose was 15.7 Gy ± 0.3 Gy. The corresponding plan quality indices were 0.30 ± 0.01 (homogeneity index), 0.94 ± 0.01 (target conformality), and 0.75 ± 0.02 (confirmation number). The median total monitor unit (MU) per fraction was 806 MU (interquartile range [IQR]: 792 to 818 MU) and the average beam total delivery time was 121.2 seconds (IQR: 120.6 to 121.35 seconds). All plans passed the gamma evaluation using the 5-mm, 4% criteria, with γ > 1 of not more than 9.1% data points for all fields. An efficient and simple planning class solution for HA-WBRT using VMAT has been developed that allows all protocol constraints of NRG-CC001 to be met.
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Jin
authors.initials: J
authors.lastname: Shen
authors.affiliation: Department of Medical Physics, University of Wisconsin, Madison, WI.
authors.forename: Edward
authors.initials: E
authors.lastname: Bender
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Ravindra
authors.initials: R
authors.lastname: Yaparpalvi
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Hsiang-Chi
authors.initials: HC
authors.lastname: Kuo
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Amar
authors.initials: A
authors.lastname: Basavatia
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Linda
authors.initials: L
authors.lastname: Hong
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: William
authors.initials: W
authors.lastname: Bodner
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Madhur K
authors.initials: MK
authors.lastname: Garg
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Shalom
authors.initials: S
authors.lastname: Kalnicki
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY; Department of Medical Physics, University of Wisconsin, Madison, WI. Electronic address: wtome@montefiore.org.
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Tomé
mesh_terms: D001932:Brain Neoplasms / Q000532:radiotherapy*; D016371:Cranial Irradiation / Q000379:methods*; D017408:Guidelines as Topic; D006624:Hippocampus / Q000528:radiation effects*; D006801:Humans; D059351:Organ Sparing Treatments / Q000379:methods* / Q000592:standards; D058958:Organs at Risk / Q000528:radiation effects*; D011835:Radiation Protection / Q000379:methods / Q000592:standards; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods* / Q000592:standards; D016896:Treatment Outcome; D014481:United States
keywords: Hippocampal avoidance; RapidArc; Treatment planning class solution; Whole-brain radiation therapy