Down with the dose.
The debate over radiation dose de-escalated therapy for HPV(+) oropharyngeal cancer continues. This phase 2 trial from the Mayo Clinic centers explored dose de-escalation in the post-operative setting. Patients with negative surgical margins received 1.5 Gy twice daily x 20 = 30 Gy over 2 weeks with weekly concurrent docetaxel. Even those with extracapsular extension (ECE) were included and received a simultaneous integrated boost to the site of ECE of 1.8 Gy twice daily x 20 = 36 Gy. At 2 years, locoregional control and survival outcomes were all well over 90% with low rates of toxicity. If outcomes are this good with 30-36 Gy for resected HPV(+) disease, it begs the question of whether 0 Gy may work just as well. | Ma, J Clin Oncol 2019
Your comment at the end of whether 0 Gy may work just as well was also addressed by Mayo investigators (Ma, the PI of the Phase II you reference, is the senior author in this paper by Routman et al IJROBP 2017). Basically, TORS alone doesn’t do well even in HPV+ tumors when traditional indicators for adjuvant RT are present. Check it out: https://www.redjournal.org/article/S0360-3016(17)33519-8/abstract
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