Real-time whole brain radiotherapy: A single institution experience

Publication date: Available online 28 December 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Anh H. Le, Strahinja Stojadinovic, Robert Timmerman, Hak Choy, Romona L. Duncan, Steve B. Jiang, Arnold Pompos
PurposeTo demonstrate the feasibility of a real-time whole brain radiation therapy (WBRT). The study takes advantage of contemporary radiotherapy capabilities and seeks to optimize clinical workflow for WBRT.MethodsWe developed a method incorporating the linac's on-board imaging system for patient simulation, utilized cone beam computed tomography (CBCT) data for treatment planning and delivered first fraction of prescribed therapy, all during patient's initial appointment. Simulation was performed in the linac vault. An acquired CBCT data set was used for scripted treatment planning protocol providing inversely planned, automated treatment plan generation. The osseous boundaries of the brain were auto-contoured to create a target volume. Two parallel-opposed beams utilizing field-in-field IMRT covered this target to the user-defined inferior level (C1 or C2). The method was commissioned utilizing an anthropomorphic head phantom and verified using 100 clinically treated patients.ResultsWhole brain target heterogeneity was within 95% to 107% of the prescription dose and target coverage compared favorably to standard manually created 3D plans. For the commissioning CBCT datasets, the secondary monitor unit (MU) verification and independent 3D dose distribution comparison for computed and delivered doses were within 2% agreement relative to the scripted auto plans. On average, time needed to complete the entire process was (35.1±10.3) minutes from CBCT start to last beam delivered.ConclusionsThe real-time WBRT workflow using integrated on-site imaging, planning, quality assurance, and delivery was tested and deemed clinically feasible. The design necessitates a synchronized team consisting of physician, physicist, dosimetrist and therapists. This work serves as a proof of concept of real time planning and delivery for other treatment sites.



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