ESTRO 2024 - Abstract Book

S1412

Clinical - Head & neck

ESTRO 2024

examination of nine regions of the oral mucosa: hard and soft palate, left and right tongue, floor of the mouth, upper and lower lip, left and right buccal. Tumor control rate was recorded during regular oncological follow-up.

Results:

The median follow-up was 19 months. 62 (73.8%) participants received primary definitive therapy and 22 (26.2%) patients received postoperative radio(chemo)therapy. The most common tumor locations were oropharynx n=37 (44%), oral cavity n=22 (26.2%), and hypopharynx n=20 (23.8%). Median dose was 69.3 Gy (range 52-70 Gy). 47 participants developed grade 3 oral mucositis after a median dose of 32 Gy. The collective was stratified by mucositis grade 3 vs. without mucositis grade 3. The presence of the following factors (yes/no) such as smoking status, concurrent systemic therapy, cisplatin administration, cumulative cisplatin dose ≥ 200mg, gender, positive HPV status, feeding tube, alcohol consumption did not show any significant correlation with the occurrence of grade 3 mucositis (Spearman correlation r >0.05 for all). Only advanced age (<65: no, ≥65: yes) showed a significant correlation with the appearance of mucositis grade 3 (Spearman correlation r =0.023). There was no significant difference in overall survival and progression-free survival between both groups (log-rank p=0.15 and log-rank p=0.29). The cumulative incidence of locoregional failures was also not different between the two arms (n=8 in each arm, log-rank p=0.75). The cumulative incidence of distant metastases was not significantly different between arms (n=9 in the mucositis grade 3 group vs. n=6 without mucositis grad 3 group, log-rank p=0.72). The cumulative incidences of deaths without previous cancer progression was significantly different between both groups (n=5 in the mucositis grade 3 vs. n=0 in the without mucositis group, log-rank test p<0.05).

Conclusion:

The high-grade radiation-assosiated mucositis does not appear to compromise oncologic response. This finding will be validated in larger multicenter collectives.

Keywords: oral mucositis, R(C)T, oncologic response

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Evaluation of prognostic factors in patients with oral tongue cancer treated with postoperative RT

Natalia Amrogowicz 1 , Tomasz Rutkowski 2 , Katarzyna Drosik-Rutowicz 1 , Urszula Kacorzyk 1 , Marek Kentnowski 1 , Anna Mucha- Małecka 3 , Krzysztof Składowski 1 1 Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice Branch, 1st Radiation and Clinical Oncology Department, Gliwice, Poland. 2 Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice Branch, Department of Radiotherapy, Gliwice, Poland. 3 Maria Sklodowska-Curie National Research Institute of Oncology, Krakow Branch, Department of Radiotherapy, Kraków, Poland