Purpose: To evaluate the normal tissue reactions and loco-regional control rates (LRC) in patients treated with 7-days-a-week postoperative continuous irradiation (p-CAIR) compared to conventionally fractionated 5-days-a-week postoperative radiotherapy (CF).
Materials/methods: Between 2001 and 2004, 279 patients with high-risk squamous cell cancer of the larynx (158 pts.) or cancer of the oral cavity/oropharynx (121 pts.) were enrolled. They were stratified according to the primary cancer site (larynx vs. others) and the treating center and randomized to receive 63 Gy in fractions of 1.8 Gy given 5-days-a-week (140 pts: CF) or 7-days-a-week (139 pts: p-CAIR).
Results: The acute and late toxicity was considered acceptable, although the proportion of patients with confluent mucositis was higher in p-CAIR compared to CF (60.0 vs. 33.3%). The actuarial 3-year LRC were 64 vs. 70% for CF and p-CAIR, respectively, p=0.32. A statistically significant improvement in 3-year LRC in p-CAIR arm appeared in a subset of the patients with cancer of the oropharynx/oral cavity (74% p-CAIR vs. 53% CF, p=0.02). By contrast, there was no improvement in LRC in a subset of the patients with cancer of the larynx (p=0.46).
Conclusion: An improvement in LRC attributable to acceleration of postoperative radiotherapy appeared restricted to the patients with cancer of the oropharynx/oral cavity. In patients with cancer of the larynx acceleration of postoperative radiotherapy did not have any beneficial effect.