The Eliminate Trial: A Phase II/III randomised trial evaluating omission of radiotherapy to regional lymphatic’s in pN0/N1 neck for Oral Cavity carcinomas

Locoregional recurrence is the predominant cause ofmortality in oral cavity carcinomas. Oralcavity carcinomas are often treated with combination of radical surgery andadjuvant radiation (RT) based on pathological findings. Risk stratification is often used for selecting patientswith unfavorable risk factors for which adjuvant postoperative adjuvant therapy± concomitant chemotherapyis administered.Post-operativeradiotherapy (PORT) in recommended in patients with high risk features ofrecurrence these include extracapsular extension, positive/ close margins,pathologically T3-4 disease, more than one lymph node involvement, lymphvascular space invasion (LVSI), perineural invasion (PNI). Addition ofchemotherapy to radiotherapy has been shown to improve treatment outcomes inpatients with extra-nodal extension and margin positive disease.

PORT is delivered to the tumor bed and regionallymphatics. Depending upon the histopathological features and location of primarytumor, unilateral or bilateral neck portals are used to addressthe microscopicdisease after surgery. Delivery of PORT is patients with high risk features isassociated with improvement in locoregional control as well as overallsurvival. However, the benefit of PORT is associated withdevelopment of significantacute and late radiation induced morbidities. These include includingdysphagia, aspiration, mucositis, altered taste sensation, xerostomia,dermatitis, fibrosis, osteoradionecrosis, voice changes, stricture, ototoxicityand hypothyroidism.

Larger RT treatment volumesare often associated with increased toxicity. At present there areno guidelinesto that define use of local versus loco-regional PORT portals for oral cavitycarcinomas. Retrospective series have demonstrated that omission of PORT toregional lymphatics in N0-N1 disease with adverse histopathological features issafe and feasible. Omission of PORT in these series has shown low rates ofisolated nodal recurrence that rangefrom 8%- 15%. Given the lack of robust evidence for omissionof PORT to regional lymphatics in patients with adverse histopathological riskfactors in pN0-N1oral cavity, a prospective randomized trial is warranted. Thepresent study is a phase II/III prospective randomized trial designed to determinewhether the omission of PORT to regional lymphatics in adequately dissectedneck in pN0-N1oral cavity is associated with similar/ improved treatmentoutcomes.