Selective omission of level V nodal coverage for patients with oropharyngeal cancer: Clinical validation of intensity‐modulated radiotherapy experience and dosimetric significance

Background We sought to validate the consensus recommendation and assess dosimetric significance of selective omission of nodal level V from intensity-modulated radiotherapy (IMRT) clinical target volume (CTV) for oropharyngeal cancer. Methods IMRT plans and clinical outcomes for 112 patients with oropharyngeal cancer (nodal classification N0–N2b) were analyzed for coverage of ipsilateral and contralateral nodal level V. Additionally, new IMRT plans were generated in 6 randomly selected patients to assess its dosimetric impact. Results With median follow-up of 3.4 years, there were no failures identified in nodal level V with or without nodal level V omission. Upon dosimetric evaluation, significant reduction in integral dose, V10 Gy, V20 Gy, V30 Gy, V40 Gy, and V50 Gy was observed by excluding unilateral and bilateral level V from the CTV. Conclusion We clinically validate the consensus recommendation for selective omission of level V nodal coverage in IMRT planning of patients with oropharyngeal cancer and demonstrate significant dosimetric advantages. © 2014 Wiley Periodicals, Inc. Head Neck, 2015