Johns Hopkins Radiation Oncology Kimmel Cancer Center Baltimore, GA
A. M. Brown1, C. Hu2, S. Ke2, R. K. Hales1, T. R. McNutt1, S. Li2, C. Snyder PhD3, S. M. Lee4, and R. Voong1; 1Johns Hopkins Radiation Oncology Kimmel Cancer Center, Baltimore, MD, 2Division of Quantitative Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 3Johns Hopkins University School of Medicine, Baltimore, MD, 4Department of Biostatistics, Columbia University School of Medicine, New York, NY
Purpose/Objective(s):No specific radiation (RT) parameter quantifying the presence and extent of circumferential esophageal RT exposure has been associated with esophageal RT toxicity. We investigate if the circumferential esophageal dose-length parameter (cDLH), that quantifies length of partial (LPdose) or full-circumferential (LFdose) esophageal dose exposure, is associated with dysphagia in patients receiving high-dose thoracic RT.Materials/
Methods: Between 2019 and 2023, consecutive patients with intrathoracic tumors treated at an academic cancer center with conventionally-fractionated RT = 60 Gy were included. Patients, treatment, and clinician-graded (CTCAE v.4) and patient-reported (PRO-CTCAE) dysphagia within 120 days of RT start were collected. Patients without dysphagia assessments and with adaptive replans were excluded. LFdose and LPdose were defined as length of esophagus with at most 90% or 50% circumference exposure to threshold radiation doses, respectively. McNemar test was used to examine the difference between clinician-reported (CTCAE) and patient-reported (PRO) dysphagia. Spearman correlation examined the relationship between Ldose to volumetric (Vdose) parameters. We evaluated associations between LFdose, LPdose and grade =2 CTCAE and PRO dysphagia using univariate logistic regression. Results: Of 127 patients identified: median age was 68 (range: 45-88), 54% were male, 78% had stage II-III or locoregionally recurrent disease, and 21% had metastatic disease. Median RT dose was 63 Gy (range: 60-70). Most patients (95%) received concurrent chemotherapy. CTCAE grade 1, 2, and 3 dysphagia occurred in 62 (48.8%), 9 (7.1%), and 0 patients, respectively. PRO grade 1, 2, 3 dysphagia occurred in 47 (37.0%), 15 (11.8%), and 8 (6.3%) patients. Among the 23 (18%) patients with discordant CTCAE and PRO dysphagia, 18 (78%) patients had grade =2 PRO dysphagia but grade =1 CTCAE dysphagia (p-value=0.002).Partial cDLH parameters, LP55 and LP60, were highly correlated with V60 (? = 0.73 and 0.75, respectively). LF60 was moderately correlated with V60 (? = 0.569). L. Each 5 mm increase in esophagus length receiving = 60 Gy to at most 50% circumference of the esophagus (LP60 ) was associated with 9% increased odds ratio of grade =2 PRO dysphagia (OR 1.09, p=0.03). Each 5 mm increase in LP55 was associated with 8% increased odds of grade =2 PRO dysphagia (1.08, p=0.04). Each 5% increase in volume of esophagus receiving 60Gy (V60) was associated with 11% increased odds of grade =2 PRO dysphagia (OR 1.11, p=0.05). Conclusion: PRO dysphagia is more sensitive to identifying toxicity associated with partial circumferential esophageal dose exposure than CTCAE dysphagia. Esophagus cDLH parameters (LP55, LP60 ) are correlated with V60. Higher LP60, which quantifies circumferential esophagus dose avoidance, is associated with grade =2 PRO dysphagia.
