ESTRO 2024 - Abstract Book

S1193

Clinical - Head & neck

ESTRO 2024

recurrences. The recurrent lesions were also analyzed based on their distances from the flap margin by classifying them into within the flap margin, within 5mm from the flap margin, 5mm to 10 mm from the flap margin, and more than 10 mm from the flap margin.

Results:

With a median follow-up of 18 (range 0-65) months, patients had a recurrence-free survival of 26 (range 16.26 35.74) months. Median OS was not reached for the cohort. Thirty-three (38.4%) received ipsilateral RT whereas 53 (61.6%) received bilateral RT. Twenty-eight had locoregional recurrences of which 5 received ipsilateral radiotherapy and 23 received bilateral radiotherapy. Of the 28 failures, there were 42.8%, 14.3%, 17.9%, 0%, and 25% type A, B, C, D, and E respectively using focal point and dosimetric methods, similar to previous studies.5 The most common failure patterns were found to be equally distributed along the anterior flap margins and in the regional neck nodes. It was found that both extracapsular extension and pathological nodal staging were predictors for bilateral neck irradiation.