ESTRO 2024 - Abstract Book

S1224

Clinical - Head & neck

ESTRO 2024

Perineural Invasion (present)

16 (21.9)

76 (41.8)

0.003

0.187

Nearest Margin (mean ± SD in cm)

7.23 ± 3.14

6.64 ± 2.79

0.140

-

Number of nodes dissected (mean ± SD)

33.67 ± 14.34

32.34 ± 13.34

0.869

-

Adjuvant radiotherapy (Yes)

27 (37.0)

141 (77.5)

<0.001

0.386

Survival endpoints: The median overall survival (OS) in the cohort ‘DOI ≤ 5mm’ was not reached for patient irrespective of post- operative radiotherapy (PORT), p = 0.59. However, in the cohort ‘DOI > 5mm’, the median OS for patients not receiving PORT was 48 (range, 39.47 – 56.53) months in comparison to those receiving PORT where median survival was not reached, p = 0.03. The median locoregional control (LRC) in the cohort ‘DOI ≤ 5mm’ not receiving PORT was 88 (range, 35.67 – 140.34) months in comparison to those receiving PORT where median survival was not reached, p = 0.46. Whereas, the median LRC in the cohort ‘DOI > 5mm’ not receiving PORT was 37 (range, 20.57 – 53.43) months in comparison to those receiving PORT where median survival was not reached, p < 0.001. (Figure 1)

Cox regression analysis : The multivariable model suggested that the use of PORT and higher margin clearance significantly improves LRC and OS in patients with DOI > 5mm whereas these factors had no impact on cohorts of patients with DOI ≤ 5mm. (Tables 2 and 3)