ESTRO 2024 - Abstract Book

S1378

Clinical - Head & neck

ESTRO 2024

subclinical regions, and 54 Gy to lower-risk areas of the neck, to 95% of all PTVs. All patients received concomitant cisplatin-based chemotherapy weekly. Disease and treatment characteristics were described. Dose-volume histograms for the brachial plexus (BP) were recomputed for the 50 patients. All patients had a minimum of two years follow-up with a mean of 37.5 months (range of 22 to 68 months). Signs and symptoms for brachial plexopathy were reviewed in all patients. Symptomatic patients were evaluated with a magnetic resonance imaging of the brachial plexus and an electromyography.

Results:

Of the 50 patients 68% were males and 32% were females with stage I/II/III disease treated with concomitant chemoradiation (98 %). The mean age at treatment was 44 years old (range 10- 68). All patients received a maximum dose of ≥ 60 Gy. Maximum dose to the BP (BPmax) was 82.64 Gy (mean 72.8 Gy).The mean dose received by 0.03 cm3 of the BP volume was 71.74 Gy. Among patients who were node positive, 86 % received a maximum dose of ≥ 66 Gy. The mean volume of BP receiving more than 60Gy (V60) was 4 cm3. The mean volume of BP receiving more than 66Gy was 2.34 cm3.After studying the correlation for N-category, there was a significant increase in BPmax dose as nodal category increases. In fact, mean BPmax for N0 versus N1 was 62.79 versus 70.88 Gy (P = 0.0001), N1 versus N2 was 70.88 versus 73.63 Gy (P = 0.0001) and N2 versus N3 was 73.63 versus 75.78 Gy (P = 0.0001).Mean BPmax for patient who had a level III/ IV nodes (75.19 Gy) was higher than mean BPmax for patient who had a level I/II (69.19 Gy) (P = 0.0001).Five patients have reported clinical acute or late brachial plexopathy but none of magnetic resonance imaging of the brachial plexus or the electromyography has confirmed it.

Conclusion:

In at high risk for relapse should never be performed in an attempt to spare the brachial plexus. It may be necessary to accept point doses above the standard maximum doses for brachial plexus to ensure adequate PTV coverage for head and neck cancers. Although long term follow-up is required. conclusion, compromising coverage of areas with known tumor and/or areas

Keywords: brachial plexus ; toxicity ; UCNT

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Digital Poster

Delineation variability on deep-learning-based super-resolution images on head-and-neck patients

Cindy Xue 1,2 , Oilei Wong 1 , Chi Wai Liu 3 , Raymond Lee 3 , Gladys G Lo 3