Impact of the surgery to radiotherapy interval on oncological outcomes in squamous cell carcinoma of the oral tongue

This study aimed to explore the relationship between the timing of radiotherapy (RT) initiation after surgery and long-term outcomes in patients with tongue squamous cell carcinoma (TSCC). We retrospectively analyzed TSCC Patients who underwent external beam radiotherapy (≥ 60 Gy) following surgical resection without evidence of distant metastasis. Patients were categorized according to tumor stage and the interval between surgery and start of RT. The primary outcomes assessed were loco-regional control (LRC), disease-free survival (DFS), and overall survival (OS). A total of 108 patients were included. Among early-stage TSCC patients, delaying RT beyond 47 days post-surgery showed no statistically significant difference in DFS. For patients with locally advanced-stage disease, a longer interval between surgery and RT was associated with a significant trend toward improved DFS. OS did not significantly differ based on RT timing across stages. Our findings suggest that modest delays in initiating postoperative RT may not adversely affect DFS or OS in early-stage TSCC, and longer intervals may not clearly determine poorer outcomes in advanced-stage disease. However, these observations are preliminary and should be interpreted with caution given the small sample size, limited number of events, and retrospective design. Larger prospective studies are required to test this hypothesis and clarify optimal timing of postoperative RT in TSCC.