ESTRO 2024 - Abstract Book

S1253

Clinical - Head & neck

ESTRO 2024

1 Aarhus University Hospital, Dept. of Experimental Clinical Oncology, Aarhus, Denmark. 2 Aarhus University Hospital, Dept. of Oncology, Aarhus, Denmark. 3 Aarhus University Hospital, Dept. of Radiophysics, Aarhus, Denmark

Purpose/Objective:

In lateralised tumours of the oral cavity and oropharynx, unilateral treatment of the neck nodes is possible due to a predominantly unilateral lymphatic drainage with sparse cross-communication of lymphatic vessels to the contra lateral side. Previous data from DAHANCA in the pre-IMRT era 1998-2001 did show unilateral treatment to be safe with 3% nodal recurrences in the untreated neck. Of these, three out of four cases had primary tumours with midline involvement. Aim of the present study was in a prospectively collected material to evaluate the outcome of unilateral treatment in the IMRT era.

Material/Methods:

All patients treated from 2007 to 2022 with primary curative intended radiotherapy for unilateral squamous cell carcinoma of the oral cavity and pharynx were included. Data was collected from the local DAHANCA database and validated by available imaging and the national pathology database to record all recurrences and their location. Death was validated using the national death registry. All patients were followed for recurrence up to five years or death. Data cut was October 1st 2023. Data was analysed using descriptive statistics. Time to recurrence or death was estimated from end of radiotherapy to histological/image confirmed recurrence or death using the Kaplan Meier method. Data was analysed with the intention-to-treat principle.

Results:

From January 2007 to the end of December 2022, 235 patients were treated with primary curative intended unilateral radiotherapy for lateralised squamous cell carcinomas of the oral cavity and pharynx. Patient and tumour characteristics are found in table 1. In total 232 patients (99%) finalised the planned radiotherapy.