Abstract
Purpose Given the limitations of extant models for normal tissue complication probability estimation for osteoradionecrosis (ORN) of the mandible, the purpose of this study was to enrich statistical inference by exploiting structural properties of data and provide a clinically reliable model for ORN risk evaluation through an unsupervised-learning analysis.
Materials and Methods The analysis was conducted on retrospective data of 1,259 head and neck cancer (HNC) patients treated at the University of Texas MD Anderson Cancer Center between 2005 and 2015. The (structural) clusters of mandibular dose-volume histograms (DVHs) were identified through the K-means clustering method. A soft-margin support vector machine (SVM) was used to determine the cluster borders and partition the dose-volume space. The risk of ORN for each dose-volume region was calculated based on the clinical risk factors and incidence rates.
Results The K-means clustering method identified six clusters among the DVHs. Based on the first five clusters, the dose-volume space was partitioned almost perfectly by the soft-margin SVM into distinct regions with different risk indices. The sixth cluster overlapped the others entirely; the region of this cluster was determined by its envelops. These regions and the associated risk indices provide a range of constraints for dose optimization under different risk levels.
Conclusion This study presents an unsupervised-learning analysis of a large-scale data set to evaluate the risk of mandibular ORN among HNC patients. The results provide a visual risk-assessment tool (based on the whole DVH) and a spectrum of dose constraints for radiation planning.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
Dr. Schaefer and Fuller received/receive related funding and salary support from National Science Foundation (NSF)/National Institutes of Health (NIH) National Cancer Institute (NCI) via the NSF/NIH Smart and Connected Health Program (R01 CA257814). Dr. Fuller received/receives related support from the National Institute of Dental and Craniofacial Research (NIDCR) Establishing Outcome Measures for Clinical Studies of Oral and Craniofacial Diseases and Conditions award (R01DE025248). Dr. Fuller receives grant and infrastructure support from MD Anderson Cancer Center via: the Charles and Daneen Stiefel Center for Head and Neck Cancer Oropharyngeal Cancer Research Program; the Program in Image-guided Cancer Therapy; and the NIH/NCI Cancer Center Support Grant (CCSG) Radiation Oncology and Cancer Imaging Program (P30CA016672). Dr. Fuller has received unrelated direct industry grant/in-kind support, honoraria, and travel funding from Elekta AB, and has served as a consulting capacity for Varian/Siemens Healthineers, Philips Medical Systems, and Oncospace, Inc.
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
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The study used ONLY openly available human data that were originally located at: https://doi.org/10.6084/m9.figshare.13568207
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Yes
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Footnotes
Conflict of interest statement: The authors declare no conflicts of interest.
Funding statement: Dr. Schaefer and Fuller received/receive related funding and salary support from National Science Foundation (NSF)/National Institutes of Health (NIH) National Cancer Institute (NCI) via the NSF/NIH Smart and Connected Health Program (R01 CA257814). Dr. Fuller received/receives related support from the National Institute of Dental and Craniofacial Research (NIDCR) Establishing Outcome Measures for Clinical Studies of Oral and Craniofacial Diseases and Conditions award (R01DE025248). Dr. Fuller receives grant and infrastructure support from MD Anderson Cancer Center via: the Charles and Daneen Stiefel Center for Head and Neck Cancer Oropharyngeal Cancer Research Program; the Program in Image-guided Cancer Therapy; and the NIH/NCI Cancer Center Support Grant (CCSG) Radiation Oncology and Cancer Imaging Program (P30CA016672). Dr. Fuller has received unrelated direct industry grant/in-kind support, honoraria, and travel funding from Elekta AB, and has served as a consulting capacity for Varian/Siemens Healthineers, Philips Medical Systems, and Oncospace, Inc.
Data Availability
All research data are publicly available at https://doi.org/10.6084/m9.figshare.13568207