ESTRO 2024 - Abstract Book

S1377

Clinical - Head & neck

ESTRO 2024

patient died in between planning CT scan and start of treatment. Mean gross tumor volume (GTV) was 139cc (range 36-630cc) at the first cycle. We observed a shrinking of mean GTV to 110cc (92%, range 26-401cc) prior to the third cycle. Overall, 6 (30%) patients were treated with immunotherapy either directly before start of RT, in between RT-cycles or immediately after end of RT. No grade 3 toxicities were observed in these patients. Only one patient developed grade 3 toxicity after receiving a 4th cycle of therapy with no systemic treatment. Median FU was 3 month, 6 patients have died.

Conclusion:

Palliative treatment of HNSCC patients using the Quad-shot regimen in combination with immuntherapy did not result in higher rates of radiation-induced toxicity and seems to be a promising treatment approach for palliative treatment of HNSCC that needs to be evaluated prospectively.

Keywords: head and nack cancer, palliation, immunotherapy

2144

Digital Poster

Brachial

plexus

dose

tolerance

In

Nasopharyngeal

Cancer

patients

treated with IMRT

Marwa Besbes, Rim Abidi, khadija ben Zid, Alia Mousli, Amani Yousfi, Walid Gargouri, Chiraz Nasr

Salah Azaiez Institut, Radiotherapy, Tunis, Tunisia

Purpose/Objective:

Radiation different parameters. Literature data suggest dose constraints ranging from 60-66Gy.Plexopathies and peripheral neuropathies were rare in head and neck cancer. It appears progressively and with several years delay after radiotherapy. The objective of our study was to evaluate late brachial plexopathy after primary chemoradiotherapy for locally advanced nasopharyngeal squamous cell carcinoma receiving IMRT (Intensity-modulated radiation therapy) and to study the maximum tolerated dose. therapy may induce brachial plexopathy depending on

Material/Methods:

Between May 2015 and March 2020, 50 patients with a history of previously irradiated nasopharyngeal cancer were retrospectively identified. All patients were treated definitively with multibeam IMRT technique and received the prescribed 70 Gy to gross tumor, 59.4 Gy to highrisk