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Yorke ED, Thor M, Gelblum DY, Gomez DR, Rimner A, Shaverdian N, Shepherd AF, Simone CB, Wu A, McKnight D, Jackson A. Treatment planning and outcomes effects of reducing the preferred mean esophagus dose for conventionally fractionated non-small cell lung cancer radiotherapy. J Appl Clin Med Phys 2021; 22:42-48. [PMID: 33492763 PMCID: PMC7882106 DOI: 10.1002/acm2.13150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 11/20/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
Based on an analysis of published literature, our department recently lowered the preferred mean esophagus dose (MED) constraint for conventionally fractionated (2 Gy/fraction in approximately 30 fractions) treatment of locally advanced non-small cell lung cancer (LA-NSCLC) with the goal of reducing the incidence of symptomatic acute esophagitis (AE). The goal of the change was to encourage treatment planners to achieve a MED close to 21 Gy while still permitting MED to go up to the previous guideline of 34 Gy in difficult cases. We compared all our suitable LA-NSCLC patients treated with plans from one year before through one year after the constraint change. The primary endpoint for this study was achievability of the new constraint by the planners; the secondary endpoint was reduction in symptomatic AE. Planners were able to achieve the new constraint in statistically significantly more cases during the year following its explicit implementation than in the year before (P = 0.0025). Furthermore, 38% of patients treated after the new constraint developed symptomatic AE during their treatment as opposed to 48% of the patients treated before. This is a clinically desirable endpoint although the observed difference was not statistically significant. A subsequent power calculation suggests that this is due to the relatively small number of patients in the study.
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Affiliation(s)
- Ellen D Yorke
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Maria Thor
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Daphna Y Gelblum
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Daniel R Gomez
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Andreas Rimner
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Narek Shaverdian
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Annemarie F Shepherd
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Charles B Simone
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Abraham Wu
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Dominique McKnight
- Department of Radiation Oncology Memorial Sloan Kettering Cancer Center, New York City, NY, USA
| | - Andrew Jackson
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, NY, USA
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