ESTRO meets Asia 2024 - Abstract Book

S190

Interdisciplinary – Head & neck

ESTRO meets Asia 2024

esophageal inlet and cervical esophagus. All patients received SIB IMRT of 66Gy, 54Gy in 30 fractions. For N3 nodes dose was further escalated to 70 Gy in 30 fractions. Swallowing-sparing IMRT was delivered by double arch VMAT using 6 MV photons (dose rate 600MU/min) (Acuros-XB algorithm version 15.6.05). Overall treatment time (OTT), compliance, toxicities, loco-regional control, disease free survival and overall survival was noted in all patients. All patients were evaluated for admission required for in-patient care, nasogastric tube insertion. Post treatment patients were subjected to 1 month follow up and 2 monthly thereafter as per departmental protocol.

Results:

A total of 316 patients were included in the analysis. Majority 89% of all the patients were males. The median age was 59 years (51-67years). The most common site of primary was Oropharynx 59.2%. Majority of the patients (83.8%) had loco regionally advanced disease at presentation [stage IV 49.8%, stage II 34%]. Doses to critical OAR has been summarized in Table 1. Median OTT was 43 days (IQR 41-46 days). Ninety-two of the patients were compliant to cancer therapy. Acute grade 3 acute toxicity was noted 34.1% patients, 23.9% patients required in patient care and 18.1% required nasogastric tube insertion during radiotherapy. No acute grade 4-5 toxicities were noted. The median follow-up was 260 days. LRC at 12 months & 18 months was 86% & 71% respectively. DFS at 12 months & 18 months was 80% & 70.9% respectively. OS at 12 months & 18 months was 83% and 72.6% respectively.

Conclusion:

Our results in large cohort of HPV negative HNC patients demonstrate feasibility of swallowing sparing IMRT using double arc VMAT. Delivery of swallowing sparing IMRT achieved 1-year LRC of 86%. Longer follow up of at least 2 years is required to confirm our finding as regards treatment outcomes.

Keywords: swallowing sparing, IMRT, VMAT

References:

1. Nutting C, Finneran L, Roe J, DARS Trialist Group, et al. Dysphagia-optimised intensity-modulated radiotherapy versus standard intensity-modulated radiotherapy in patients with head and neck cancer (DARS): a phase 3, multicentre, randomised, controlled trial. Lancet Oncol. 2023;24:868–80.