Technical Note: A step‐by‐step guide to Temporally Feathered Radiation Therapy planning for head and neck cancer

• Authors: Shireen Parsai, Taussig Cancer Institute; Richard L. J. Qiu, Emory University; Peng Qi, Taussig Cancer Institute; Juan C. L. Alfonso, Hemholtz Centre of Infection Research; Jeremy Donaghue, Taussig Cancer Institute; Eric Murray, Taussig Cancer Institute; David Majkszak, Taussig Cancer Institute; Nicole Dorio, Taussig Cancer Institute; Clifton D. Fuller, University of Texas MD Anderson Cancer Center; Kristy Brock, University of Texas MD Anderson Cancer Center; Shlomo Koyfman, Taussig Cancer Institute; Neil Woody, Taussig Cancer Institute; Nikhil Joshi, Taussig Cancer Institute; Jacob G. Scott, Taussig Cancer Institute
• Journal Title: Journal of Applied Clinical Medical Physics
• Volume: Volume 21, Number 7
• Publisher: The American College of Medical Physics and American Institute of Physics | 2020-07-01, Pages 209-215
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1002/acm2.12893
• Subjects: Health Sciences, Toxicology; Health Sciences, Medicine and Surgery; Health Sciences, Rehabilitation and Therapy
• Keywords: head and neck planning; IMRT; reduce toxicity; temporally feathered radiation therapy; TFRT

Abstract

Purpose Prior in silico simulations propose that Temporally Feathered Radiation Therapy (TFRT) may reduce toxicity related to head and neck radiation therapy. In this study we demonstrate a step‐by‐step guide to TFRT planning with modern treatment planning systems. Methods One patient with oropharyngeal cancer planned for definitive radiation therapy using intensity‐modulated radiation therapy (IMRT) techniques was replanned using the TFRT technique. Five organs at risk (OAR) were identified to be feathered. A “base plan” was first created based on desired planning target volumes (PTV) coverage, plan conformality, and OAR constraints. The base plan was then re‐optimized by modifying planning objectives, to generate five subplans. All beams from each subplan were imported onto one trial to create the composite TFRT plan. The composite TFRT plan was directly compared with the non‐TFRT IMRT plan. During plan assessment, the composite TFRT was first evaluated followed by each subplan to meet preset compliance criteria. Results The following organs were feathered: oral cavity, right submandibular gland, left submandibular gland, supraglottis, and OAR Pharynx. Prescription dose PTV coverage (>95%) was met in each subplan and the composite TFRT plan. Expected small variations in dose were observed among the plans. The percent variation between the high fractional dose and average low fractional dose was 29%, 28%, 24%, 19%, and 10% for the oral cavity, right submandibular, left submandibular, supraglottis, and OAR pharynx nonoverlapping with the PTV. Conclusions Temporally Feathered Radiation Therapy planning is possible with modern treatment planning systems. Modest dosimetric changes are observed with TFRT planning compared with non‐TFRT IMRT planning. We await the results of the current prospective trial to seeking to demonstrate the feasibility of TFRT in the modern clinical workflow (NCT03768856). Further studies will be required to demonstrate the potential benefit of TFRT over non‐TFRT IMRT Planning.