Hypofractionated radiotherapy alone with 2.4 Gy per fraction for head and neck cancer during the COVID-19 pandemic: The Princess Margaret experience and proposal.

ABSTRACT

BACKGROUND: The objective of this study was to identify a subgroup of patients with head and neck squamous cell carcinoma (HNSCC) who might be suitable for hypofractionated radiotherapy (RT-hypo) during the COVID-19 pandemic. METHODS: HNSCC cases (oropharynx/larynx/hypopharynx) treated with definitive RT-hypo (60 Gy in 25 fractions over 5 weeks), moderately accelerated radiotherapy (RT-acc) alone (70 Gy in 35 fractions over 6 weeks), or concurrent chemoradiotherapy (CCRT) during 2005-2017 were included. Locoregional control (LRC) and distant control (DC) after RT-hypo, RT-acc, and CCRT were compared for various subgroups. RESULTS: The study identified 994 human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma cases (with 61, 254, and 679 receiving RT-hypo, RT-acc, and CCRT, respectively) and 1045 HPV- HNSCC cases (with 263, 451, and 331 receiving RT-hypo, RT-acc, and CCRT, respectively). The CCRT cohort had higher T/N categories, whereas the radiotherapy-alone patients were older. The median follow-up was 4.6 years. RT-hypo, RT-acc, and CCRT produced comparable 3-year LRC and DC for HPV+ T1-2N0-N2a disease (seventh edition of the TNM system [TNM-7]; LRC, 94%, 100%, and 94%; P = .769; DC, 94%, 100%, and 94%; P = .272), T1-T2N2b disease (LRC, 90%, 94%, and 97%; P = .445; DC, 100%, 96%, and 95%; P = .697), and T1-2N2c/T3N0-N2c disease (LRC, 89%, 93%, and 95%; P = .494; DC, 89%, 90%, and 87%; P = .838). Although LRC was also similar for T4/N3 disease (78%, 84%, and 88%; P = .677), DC was significantly lower with RT-hypo or RT-acc versus CCRT (67%, 65%, and 87%; P = .005). For HPV- HNSCC, 3-year LRC and DC were similar with RT-hypo, RT-acc, and CCRT in stages I and II (LRC, 85%, 89%, and 100%; P = .320; DC, 99%, 98%, and 100%; P = .446); however, RT-hypo and RT-acc had significantly lower LRC in stage III (76%, 69%, and 91%; P = .006), whereas DC rates were similar (92%, 85%, and 90%; P = .410). Lower LRC in stage III predominated in patients with laryngeal squamous cell carcinoma receiving RT-acc (62%) but not RT-hypo (80%) or CCRT (92%; RT-hypo vs CCRT P = .270; RT-acc vs CCRT P = .004). CCRT had numerically higher LRC in comparison with RT-hypo or RT-acc in stage IV (73%, 65%, and 66%; P = .336). CONCLUSIONS: It is proposed that RT-hypo be considered in place of CCRT for HPV+ T1-T3N0-N2c (TNM-7) HNSCCs, HPV- T1-T2N0 HNSCCs, and select stage III HNSCCs during the COVID-19 outbreak.