Feasibility of simulation free abdominal stereotactic adaptive radiotherapy using an expedited pre-plan workflow

Autor: Alex T. Price, Joshua P. Schiff, Alice Silberstein, Robbie Beckert, Tianyu Zhao, Geoffrey D. Hugo, Pamela P. Samson, Eric Laugeman, Lauren E. Henke
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Physics and Imaging in Radiation Oncology, Vol 31, Iss , Pp 100611- (2024)
Druh dokumentu: article
ISSN: 2405-6316
DOI: 10.1016/j.phro.2024.100611
Popis: Background and Purpose: Improved hounsfield-unit accuracy of on-board imaging may lead to direct-to-unit treatment approaches We aimed to demonstrate the feasibility of using only a diagnostic (dx) computed tomography (CT)-defined target pre-plan in an in silico study of simulation-free abdominal stereotactic adaptive radiotherapy (ART). Materials and Methods: Eight patients with abdominal treatment sites (five pancreatic cancer, three oligometastases) were treated using an integrated adaptive O-Ring gantry system. Each patient’s target was delineated on a dxCT. The target only pre-plan served primarily to seed the ART process. During the ART session, all structures were delineated. All simulated cases were treated to 50 Gy in 5 fractions to a planning target optimization structure (PTV_OPT) to allow for dose escalation within the planning target volume. Timing of steps during this workflow was recorded. Plan quality was compared between ART treatment plans and a plan created on a CT simulation scan using the traditional planning workflow. Results: The workflow was feasible in all attempts, with organ-at-risk (OAR) constraints met in all fractions despite lack of initial OAR contours. Median absolute difference between the adapted plan and simulation CT plan for the PTV_Opt V95% was 2.0 %. Median absolute difference in the D0.5 cm3 between the adapted plan and simulation CT plan was −0.9 Gy for stomach, 1.2 Gy for duodenum, −5.3 Gy for small bowel, and 0.3 Gy for large bowel. Median end-to-end workflow time was 63 min. Conclusion: The workflow was feasible for a dxCT-defined target-only pre-plan approach to stereotactic abdominal ART.
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