ESTRO 2025 - Abstract Book

S1067

Clinical – Head & neck

ESTRO 2025

adjuvant radiation to the postoperative bed, but did not receive elective neck dissection (eND) and/or elective nodal irradiation (eNI).

Material/Methods: We analyzed 40 consecutive patients with clinical or pathologic T1-4N0M0 sinonasal cancer, treated with curative intent between 2007-2021. Seven out of the forty patients had neck dissections with or without elective nodal coverage in their adjuvant radiation treatment and were excluded from the study. Of the 33 patients included in the study, only 10 patients (30%) received either neoadjuvant or concurrent chemotherapy with their radiation treatments. Median RT dose was 60 Gy [56.4 – 69.6 Gy], and median number of fractions was 50 [28-58]. Primary endpoint was regional progression free survival (RPFS). Secondary endpoints included, local progression free survival (LPFS), distant metastasis free survival (DMFS) and overall survival (OS). Results: The median age was 61 years and median time of follow up was 6 years. Squamous cell carcinoma (SCC) and Esthesioneuroblastoma (ENB) were the most common histologic subtypes. Only Five patients [15 %] had observed recurrences in the untreated neck and were mostly T4 disease. All five patients were successfully salvaged. The histologic subtypes with observed regional recurrences were ENB (3 patients), SMARCB1 deficient/small cell neuroendocrine carcinoma (2 patients). Level 1b, II and retropharyngeal nodes were the sites of observed regional recurrences. Median time to regional recurrence was 4 years. RPFS at 2 and 5 years were 88% and 76% respectively. LPFS at 2 and 5 years were 82% and 58% respectively. DMFS at 2 and 5 years were 88% and 70% respectively. OS at 2 and 5 years were 94% and 79% respectively. Conclusion: We found low to moderate regional recurrence rates in cN0 patients who did not receive eND or eNI. Of note, there were no regional recurrences in patients with SCC regardless of T stage. More research is needed to identify clinical and histologic features of sinonasal cancers that may be candidate for omission or treatment of the elective neck in this population.

Keywords: sinonasal, cancer,

References: Galloni C, Locatello LG, Bruno C, Cannavicci A, Maggiore G, Gallo O. The Role of Elective Neck Treatment in the Management of Sinonasal Carcinomas: A Systematic Review of the Literature and a Meta-Analysis. Cancers . 2021; 13(8):1842. https://doi.org/10.3390/cancers13081842

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Digital Poster Automated imaging-based tumor burden predicts pre-treatment circulating tumor DNA in HPV-associated oropharynx cancers Mina Bakhtiar 1 , Zezhong Ye 2 , Jonathan D Schoenfeld 2 , Homan Mohammadi 3 , Eleni M Rettig 4 , Glenn J Hanna 5 , Benjamin H Kann 2 1 Harvard Radiation Oncology Program, Brigham & Women's Hospital/Dana Farber Cancer Institute & Massachusetts General Hospital, Boston, USA. 2 Department of Radiation Oncology, Brigham & Women's Hospital/Dana Farber Cancer Institute, Boston, USA. 3 Department of Radiation Oncology, Mayo Clinic, Jacksonville, USA. 4 Department of Otolaryngology, Brigham & Women's Hospital/Dana Farber Cancer Institute, Boston, USA. 5 Department of Head & Neck Medical Oncology, Dana Farber Cancer Institute, Boston, USA