3756 - Emergency Room (ER) Utilization Rate Among Patients with HPV related Oropharynx Cancer Undergoing Radiation De- Escalation

Y. Wu¹, E. C. Dee², G. Wasilewski¹, N. Riaz², R. J. Wong³, E. Sherman⁴, and N. Y. Lee¹; ¹Memorial Sloan Kettering Cancer Center, New York, NY, ²Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, ³Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, ⁴Department of Medical Oncology, Memorial Sloan Kettering Cancer Center, New York, NY

Purpose/Objective(s): HPV related oropharynx cancer (HPV+ OPC) is increasing in incidence in the US. The most common standard non-surgical treatment of loco-regionally advanced HPV+ OPC is concurrent cisplatin chemotherapy with radiation to 70Gy. This treatment is associated with substantial morbidities such as dehydration, weight loss, and acute kidney injury (AKI), resulting in subsequent increased healthcare utilization including emergency room (ER) visits. Prospective trials at our center explored the role of tumor hypoxia to direct radiation dose de-escalation to 30Gy with chemotherapy while preserving treatment efficacy of HPV+ OPC. We examined the ER utilization rates comparing patients who received radiation to 30Gy vs 70Gy on trial. Materials/

Methods: Patients with HPV+ OPC were enrolled and underwent 18F-fluoromisonidazole PET scan which was used to measure tumor hypoxia and guide radiation to either 30Gy or 70Gy (oncologic results reported elsewhere). Patient visits at the institution’s and outside ERs were recorded from the start of radiation to 8 weeks after the completion of chemoradiation treatment. Rates of ER utilization, defined as the percentage of patients who presented to ER were compared between those who received radiation to 30Gy vs those treated to 70Gy.
Results: We analyzed 305 patients on trial, of whom 234 received 30Gy radiation (76.7%). Of the total cohort, 63 had at least one ER visit in the specified timeframe (20.7%). However, upon stratification by RT dose, only 39 of 234 patients (16.7%) who received 30Gy had ER visits, compared with 24 of 71 patients (33.8%) who received 70Gy (chi2 P=0.002). 2 of 234 (0.85%) patients who received 30Gy had 2 ER visits, while 5 of 71 (7%) patients who received 70Gy had 2 ER visits (chi2 P=0.002). No patients had more than 2 ER visits. The most common reasons for ER visits were fever, syncope, dehydration, nausea and vomiting, and AKI. Among the patients who had the ER visits, 17 (7.3%) patients who received 30Gy were hospitalized, whereas 13 (18.3%) patients who received 70Gy were hospitalized (chi2 P=0.006).
Conclusion: In this cohort of patients undergoing definitive chemoradiation for HPV+ OPC, 30Gy was associated with decreased rate of ER utilization by ~50% compared with 70Gy when followed from the start of radiation to 8 weeks after treatment. Patients who received 70Gy had higher rates of > 1 ER visits versus the 30Gy cohort. These findings suggest that in addition to lower morbidity with 30Gy, the direct consequence is decreased ER healthcare utilization compared to the standard 70Gy cohort, underscoring the importance of exploring dose de-escalation strategies in HPV+ OPC to decrease financial burden and healthcare expenditure.