2025 Proffered Presentations
S155: PROTON BEAM RADIOTHERAPY VERSUS INTENSITY-MODULATED RADIOTHERAPY IN OLFACTORY NEUROBLASTOMA: A MULTI-INSTITUTIONAL PROPENSITY MATCHED STUDY
Anthony Tang1; Jack K Donohue1; Samuel Adida1; Joao Paulo Almeida2; Pierre-Olivier Champagne3; Juan Fernandez-Miranda4; Paul Gardner5; Peter Hwang6; Jayakar Nayak6; Chirag Patel7; Zara Patel6; Maria Peris-Celda8; Carlos Pinheiro-Neto9; Olabisi Sanusi10; Carl Snyderman11; Brian D Thorp12; Jamie J Van Gompel8; Georgios A Zenonos5; Nathan T Zwagerman13; Eric W Wang11; Mathew Geltzeiler14; Garret W Choby11; 1University of Pittsburgh, School of Medicine; 2Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida, USA; 3Department of Neurosurgery, CHU de Québec-Université Laval, Quebec City, Quebec, Canada; 4Department of Neurosurgery, Stanford Hospital, Stanford, California.; 5Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; 6Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, California, USA; 7Department of Otolaryngology-Head and Neck Surgery, Loyola University Medical Center, Maywood, Illinois, United States; 8Department of Neurologic Surgery, Mayo Clinic,Rochester, MN; 9Department of Otorhinolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, US; 10Department of Neurosurgery, Oregon Health & Science University, Portland, Oregon, USA; 11Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; 12Department of Otolaryngology/Head and Neck Surgery at the University of North Carolina, Chapel Hill, North Carolina, USA; 13Department of Neurosurgery, Froedtert and the Medical College of Wisconsin, Milwaukee, Wisconsin, USA; 14Department of Otolaryngology-Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon, USA
Introduction: Olfactory Neuroblastoma (ONB) is a rare sinonasal malignancy that can present with locally advanced disease. Previous studies have demonstrated that post-resection radiotherapy can provide a survival and recurrence advantage in patients with ONB, particularly in the setting of higher stage and histologic grade. Two of the main methods of radiotherapy delivery include proton beam radiotherapy (PBRT) and intensity-modulated radiotherapy (IMRT). The differences in the effectiveness of these two methods have been studied in other fields including head and neck cancer, however, no studies comparing the two methods have been studied for patients with ONB. Therefore, the purpose of this study is to compare the differences in survival and recurrence for ONB patients being treated with PBRT and IMRT using propensity-matched cohorts from a multi-institutional database.
Methods: This modern-era multi-center data originated from the retrospective review of electronic health records (EHRs) of all patients who presented with ONB between 2005 and 2021 at nine academic, tertiary care centers within North America. Only patients treated with either IMRT or PBRT were included in the study. Clinicopathologic features including treatment modalities, pathologic and MRI imaging status, modified Kadish staging systems, Hyams grading, margin-status, and follow-up time. Outcomes collected for analysis included local recurrence-free survival (Local-RFS), regional recurrence-free survival (Regional-RFS), total recurrence-free survival (RFS), and overall surval (OS). Propensity matching of age, gender, Hyams grade, modified Kadish staging, resection margin-status, and chemotherapy use (Table 1) between treatment modalities was confirmed with chi-square and fisher exact tests. Statistical analysis was done using Kaplan-Meier curves and log-rank tests.
Results: Of the 205 ONB patients treated with surgical resection and adjuvant radiation therapy for curative intent, 18 patients were identified to receive PBRT. This cohort was then matched to the current standard of IMRT at a 1:1 ratio for a total of 36 patients in this multi-institutional study. The average follow-up time for IMRT was 71.7 (SD, 52.9) months and for PBRT was 53.2 (SD, 39.5) months (P=0.24). For IMRT, the 5-year local-RFS, Regional-RFS, RFS and 5-year OS were 69.2%, 92.9%, 64.8%, and 80.8%, respectively. For PBRT, the 5-year local-RFS, Regional-RFS, RFS and 5-year OS were 90.9%, 79.7%, 56.7%, and 85.7%, respectively. Similarly, there were no differences in local RFS (P=0.34, Figure 1), regional RFS (P=0.29, Figure 2), total recurrence-free survival (P=0.4, Figure 3), and overall survival (P=0.52, Figure 4) between patients treated with PBRT and IMRT.
Conclusion: This study is the first to compare the effectiveness of IMRT and PBRT in patients with advanced olfactory neuroblastoma. These findings support that IMRT and PBRT are comparable in overall survival and recurrence-free survival as treatment methods for advanced stage/grade olfactory neuroblastoma. Future investigations comparing quality-of-life outcomes between these radiotherapy modalities are needed to better delineate patient-centered treatments for ONB.
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