ESTRO 2024 - Abstract Book

S1335

Clinical - Head & neck

ESTRO 2024

Ishaan Paul Parokkaran 1 , Alastair McCabe 2 , Matthew Griffin 2 , Judith Christian 2

1 University of Nottingham, Faculty of Medicine, and Health Sciences, Nottingham, United Kingdom. 2 Nottingham University Hospitals NHS Trust, Radiotherapy Department, Nottingham, United Kingdom

Purpose/Objective:

Larynx preservation treatment options for early larynx cancer include transoral laser microsurgery, conventional radiotherapy (RT), and hypofractionated RT. A variety of RT dose-fractionation regimens have been employed worldwide for the treatment of early glottic carcinoma, with hypofractionated RT providing an advantage over conventional RT due to its shorter overall treatment time. Moreover, many institutions have shown hypofractionation yields better results in local control and survival rates when compared to conventional fractionation 1-6 . However, insufficient meta-analysis exists regarding the optimal RT dose 7 . We evaluated disease specific survival (DSS) and laryngectomy-free survival (LFS) in early-stage laryngeal squamous cell carcinoma (LSCC) treated with definitive hypofractionated RT.

Material/Methods:

A retrospective clinical audit was conducted at Nottingham University Hospital NHS Trust, involving a review of patient electronic case notes. Inclusion criteria were patients with histologically confirmed squamous cell carcinoma of the glottis, primary tumour staged as Tis, T1, or T2, node negative, who commenced curative hypofractionated RT between June 2010 and November 2022. Patients were treated with one of two hypofractionated regimes, either 50Gy in 16 daily fractions (50/16) or 55Gy in 20 daily fractions (55/20). DSS and LFS were estimated using the Kaplan Meier survival method.

Results:

A total of 173 patients satisfied the inclusion criteria of this audit. Among them, the median age was 68 years (range, 43-94), with a median follow up of 60 months (range, 0-161). 110 patients were in the 50/16 RT group and 63 in the 55/20 group. As shown in Table 1, no significant differences in demographics were found between groups. However, the 55/20 group had a significantly higher proportion of patients with T2 stage tumours. The five-year DSS rate for the entire cohort was 93.4% (95% CI, 88-96.4%), with a 94.6% (95% CI, 87.4-97.8%) survival rate in the 50/16 group compared to 91.1% (95% CI, 79.8-96.2%) in the 55/20 group. The five-year LFS rate for the entire cohort was 89.2% (95% CI, 82.9-93.3%), with a 91.2% (95% CI, 83.1 – 95.5%) laryngectomy-free rate in the 50/16 group compared to 85.5% (95% CI, 73-92.5%) in the 55/20 group.

Radiotherapy Regimen

50Gy / 16#

55Gy / 20#

p value

Characteristics

(n=110)

(n=63)

Gender

Male

96 (87.3%)

53 (84.1%)

0.565

Female

14 (12.7%)

10 (15.9%)