ESTRO 2024 - Abstract Book

S1460

Clinical - Head & neck

ESTRO 2024

Our findings suggest that NACT + RT has substantially better tolerance and compliance rates than NACT + CCRT. NACT + RT displayed similar survival outcomes as NACT + CCRT for NPC patients with a CR/PR after NACT (ClinicalTrials.gov number, NCT03015727).

Keywords: nasopharyngeal carcinoma, radiotherapy

3409

Proffered Paper

Radiotherapy vs. Trans-Oral Surgery for Treatment De-Escalation in HPV-Associated Oropharyngeal Squamous Cell Carcinoma: Primary Analysis of the ORATOR2 Trial

David A. Palma 1 , Eric Berthelet 2 , Sarah Hamilton 2 , Jonn Wu 2 , Antoine Eskander 3 , Kevin Higgins 3 , Irene Karam 4 , Michael Hier 5 , Keith Richardson 5 , Alex Mlynarek 5 , Marc Gaudet 6 , Andrew Bayley 7 , Marcin Dzienis 8 , Shamir Chandarana 9 , Robyn Banerjee 10 , Robert Hart 9 , Jeffson Chung 11 , Hien Le 12 , Eric Winquist 13 , Andrew Warner 1 , Jeff Chen 1 , Julie Theurer 14 , Lucas C. Mendez 1 , Nancy Read 1 , Anthony C. Nichols 15 1 London Health Sciences Centre, Radiation Oncology, London, Canada. 2 University of British Columbia, Radiation Oncology, Vancouver, Canada. 3 Sunnybrook Health Sciences Centre, Otolaryngology - Head and Neck Surgery, Toronto, Canada. 4 Sunnybrook Health Sciences Centre, Radiation Oncology, Toronto, Canada. 5 McGill University, Otolaryngology - Head and Neck Surgery, Montreal, Canada. 6 University of Ottawa, Radiation Oncology, Ottawa, Canada. 7 University of Toronto, Radiation Oncology, Toronto, Canada. 8 Gold Coast University Hospital, Medical Oncology, Southport, Australia. 9 University of Calgary, Otolaryngology - Head and Neck Surgery, Calgary, Canada. 10 University of Calgary, Radiation Oncology, Calgary, Canada. 11 West Virginia University, Otolaryngology - Head and Neck Surgery, Morgantown, Canada. 12 Royal Adelaide Hospital, Radiation Oncology, Adelaide, Australia. 13 London Health Sciences Centre, Medical Oncology, London, Canada. 14 Western University, School of Communication Sciences and Disorders, London, Canada. 15 London Health Sciences Centre, Otolaryngology - Head and Neck Surgery, London, Canada

Purpose/Objective:

Treatment de-escalation for human-papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) has the dual goals of reducing toxicity and maintaining excellent rates of cure. Herein we report the primary overall survival (OS) analysis of the ORATOR2 trial, which assessed radiotherapy (RT)-based vs. transoral surgery (TOS)- based approaches.

Material/Methods:

We enrolled patients with T1-2N0-2 p16-positive OPSCC, and randomized them to primary RT (60 Gy of RT, with weekly cisplatin in node-positive patients) vs. primary transoral surgery and neck dissection (TOS + ND, with adjuvant reduced-dose RT depending on pathologic findings). The primary endpoint was 2-year OS, hypothesized to