Dosimetric Predictors of Patient-Reported Xerostomia and Dysphagia With Deintensified Chemoradiation Therapy for HPV-Associated Oropharyngeal Squamous Cell Carcinoma

作者：Chera Bhishamjit S^*; Fried David; Price Alex; Amdur Robert J; Mendenhall William; Lu Chiray; Das Shiva; Sheets Nathan; Marks Lawrence; Mavroidis Panayiotis

来源：International Journal of Radiation Oncology, Biology, Physics, 2017, 98(5): 1022-1027.

DOI：10.1016/j.ijrobp.2017.03.034

Purpose/Objective(s): To estimate the association between different dose-volume metrics of the salivary glands and pharyngeal constrictors with patient reported severity of xerostomia/dysphagia in the setting of deintensified chemoradiation therapy (CRT).
Methods and Materials: Forty-five patients were treated on a phase 2 study assessing the efficacy of deintensified CRT for favorable-risk, HPV-associated oropharyngeal squamous cell carcinoma. Patients received 60 Gy intensity modulated radiation therapy with concurrent weekly cisplatin (30 mg/m(2)), and reported the severity of their xerostomia/dysphagia (before and after treatment) using the patient-reported outcome version of the Common Terminology Criteria for Adverse Events (CTCAE) (PRO-CTCAE). Individual patient dosimetric data of the contralateral parotid and submandibular glands and pharyngeal constrictors were correlated with changes in PRO-CTCAE severity. A change in severity (from baseline) of >= 2 was considered clinically meaningful. Associations between dose-volume metrics and patient outcomes were assessed with receiver operating characteristic (ROC) curve and logistic regression model.
Results: Sixmonths after CRT, patients reporting <2 change in xerostomia severity (n=14) had an average D-mean = 22 +/- 9 Gy to the sum of the contralateral glands (parotid + submandibular) compared with the patients reporting >= 2 change (n=21), who had an average D-mean = 34 +/- 8 Gy. V15 to V55 for the combined contralateral glands showed the strongest association with xerostomia (area under the curve [AUC] = 0.83-0.86). Based on the regression analysis, a 20% risk of toxicity was associated with V15 = 48%, V25 = 30%, and D-mean=21 Gy. Six months after CRT, patients reporting <2 change in dysphagia severity (n=26) had an average V55 = 76 +/- 13 (%) to the superior pharyngeal constrictor compared with the patients reporting >= 2 change in severity (n=9), who had average V55 = 89 +/- 13 (%). V55to V60 had the strongest association with dysphagia (AUC = 0.70-0.75). Based on the regression analysis, a 20% risk of toxicity was associated with V55 = 78%, V60 = 40%. The findings at 12 months were similar.
Conclusions: After deintensified CRT, the rate of patient-reported xerostomia/dysphagia appears to be associated with the V15 of the combined contralateral salivary glands and V55 to V60 of the superior pharyngeal constrictors.

• 出版日期2017-8-1