ESTRO 2024 - Abstract Book

S1246

Clinical - Head & neck

ESTRO 2024

with baseline swallowing dysfunction and those who received neoadjuvant chemotherapy were excluded. Stratification factors were definitive versus (vs) adjuvant RT, technique of RT, concurrent chemotherapy use, primary tumor site, and nodal status. The hypothesis was that the absolute proportion of patients with significant weight loss would be 10% lower in the prophylactic arm (30% to 20%). A sample size of 580 to be accrued over five years was estimated to detect this difference (power 80%, two-sided alpha 5%, chi-squared test). The study was approved by the Institutional Ethics Committee (IEC No: 3297) and registered with the Clinical Trials Registry of India (CTRI/2020/01/023049).

Results:

Between July 2020 and March 2023, 83 of the 224 patients screened, were randomized in the study, due to a high denial rate (>80%) for feeding tube insertion. Due to slow accrual, the trial was prematurely closed in September 2023 after IEC notification. Two of the 83 patients died during RT; hence, we analyzed 81 patients on an intention-to treat basis. Thirty-nine were randomized to the prophylactic arm (all NGT) and 42 to the reactive arm. Out of 39 patients in the prophylactic arm, six refused NGT insertion, and 2 removed NGT within the first week of RT. In the reactive arm, one patient progressed on treatment and received palliative RT. Median age in the prophylactic and reactive arms was 47 years and 52.5 years, respectively, with a majority of patients being males. Most had oral cavity primaries (24 prophylactic, 29 reactive), were treated with conventional RT (28 prophylactic, 27 reactive), and received concurrent chemotherapy (21 prophylactic, 23 reactive). The median weight at baseline was 57.6kg (IQR:51.2-67.6) vs 59kg (IQR:50.5-69.2), p=0.92, and median Body Mass Index (BMI) was 21.7kg/mt2 (IQR:18.9-24.2) vs. 22.3kg/mt2 (IQR:18.9-24.5), p=0.43 in the prophylactic and reactive arms, respectively. In the reactive arm, 40.4% required feeding tube insertion during RT, due to severe oral/oropharyngeal mucositis. The total number of patients evaluable at conclusion of RT was 81 (39 prophylactic, 42 reactive); at three months post-RT, were 77 (38 prophylactic, 39 reactive), and at six months post-RT were 67 (33 prophylactic, 34 reactive). Median weight in prophylactic vs. reactive arms at various time points after RT were as follows - at conclusion: 53.6kg (IQR:48-60) vs. 54.6kg (IQR:48.7-65), p=0.73; at three months post-RT: 53.2kg (IQR:45.7-61) vs. 54.8kg (IQR:48 63), p=0.91 and at six months post-RT: 53kg (IQR:47.5-64.7) vs. 54kg (IQR:50-67), p=0.89. The median BMI in the prophylactic vs. reactive arms at various time points after RT were as follows- at conclusion: 20kg/mt2 (IQR:17.3 22.1) vs. 20.6kg/mt2 (IQR:17.9-24), p=0.43; at three months post-RT: 19.7kg/mt2 (IQR:16.3-22.1) vs. 20.6kg/mt2 (IQR:17.5-23), p=0.56 and at six months post-RT: 19.5kg/mt2 (IQR:16.7-23.4) vs. 20.6kg/mt2 (IQR:18.1-23.2), p=0.71 (Figure 1). Proportion of patients with significant weight loss in the prophylactic vs. reactive