2744 - A Double-Blinded Analysis of Anterior Oral Mucositis in Patients with Advanced Oropharyngeal Cancer Treated with IMPT vs. IMRT
Presenter(s)
K. E. Fink1, D. Swanson2, R. Ferrarotto2, E. M. Sturgis3, Z. Liao4, R. L. Foote5, P. M. Busse6, S. H. Patel7, J. W. Snider III8, G. B. Gunn9, M. W. McDonald10, N. S. Kalman11, S. R. Katz12, G. K. Bajaj13, C. Hyde14, C. Henson15, A. S. Garden9, D. J. Ma5, X. Zhang16, and S. J. Frank17; 1Feinberg School of Medicine, Chicago, IL, 2The University of Texas MD Anderson Cancer Center, Houston, TX, 3Baylor College of Medicine, Houston, TX, 4Department of Thoracic Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 5Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 6Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 7Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 8South Florida Proton Therapy Institute, Delary Beach, FL, 9Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, 10Winship Cancer Institute of Emory University, Atlanta, GA, 11Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 12Willis-Knighton Cancer Center, Shreveport, LA, 13University of Maryland Medical Center, Baltimore, MD, 14Karmanos Cancer Institute at McLaren Flint, Flint, MI, 15University of Oklahoma Health Sciences Center, OKLAHOMA CITY, OK, 16Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 17Department of Genitourinary Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
Purpose/Objective(s):
Oral mucositis is a common acute side effect of chemoradiation therapy for advanced oropharyngeal cancer (OPC). Sequelae of oral mucositis such as oral pain, dysgeusia, xerostomia, and microbial contamination can lead to increased opioid use, candidiasis, odynophagia, dysphagia, sarcopenia, malnutrition, and gastrostomy-tube dependence. Intensity-modulated proton therapy (IMPT) is increasingly used to treat OPC for its ability to reduce the radiation dose to the anterior oral cavity relative to intensity-modulated photon radiation therapy (IMRT). In this double-blinded study, we evaluated whether oncologists can discern, on photographic images of the anterior oral cavity, any difference in rates and severity of anterior oral mucositis (AOM) during or after IMPT vs IMRT for advanced OPC.Materials/Methods:
Eligible patients were enrolled in a national multicenter phase III randomized trial comparing concurrent chemoradiation with IMPT vs IMRT for OPC. All patients were prescribed 70 Gy in 33 fractions to the primary disease in the oropharynx, and the mean dose to the oral cavity among all participants was lower after IMPT vs IMRT (23.6 vs 33.4 Gy, p < 0.01). Standardized images of patients' oral cavities (tongue out, tongue left, tongue right, and soft palate) were captured by professional medical photographers at baseline, mid-treatment, completion, and 8-12 weeks post-treatment (first follow-up). Slides containing one baseline image and one image (obtained during or after treatment) side by side were generated for each patient. Slides were evaluated by a non-head and neck radiation oncologist, a head and neck surgical oncologist, and a head and neck medical oncologist, who graded AOM severity as 0-4 per the Common Terminology Criteria for Adverse Events v4.0. Evaluators were blinded to both timepoint and treatment modality. Interobserver variability was assessed with Cohen’s kappa statistic, and proportions of grade 3+ mucositis were compared across treatment modalities and tumor sizes with chi-square tests.Results:
We analyzed 298 discrete slides (596 images) from 108 randomized patients (51 IMPT, 57 IMRT). Primary tumor T status was not significantly different between IMPT and IMRT groups at any of the three time points (all p > 0.05) Concordance amongst oncologists on AOM grade was greater at the end of treatment (? = 0.3) than at mid-treatment or first follow-up (? = 0.15). No differences were found in proportion of toxicity grades by treatment type at mid-, end-, and 8-12-week follow-up (all p > 0.05).Conclusion:
High-grade AOM could not be seen on photographs as being significantly different after IMPT vs IMRT. Future studies will aim to correlate differences in oral cavity dose between IMPT and IMRT with patient-reported outcomes.