A feasibility Study of the Dosimetric Compliance Criteria of the NRG-HN002 Head and Neck Clinical Trial Across Different Radiotherapy Treatment Planning Systems and Delivery Techniques: A Model for Optimizing Initial Trial Launch

The aim of this study was to assess the feasibility of the dosimetric compliance criteria of the NRG-HN002 clinical trial, using different treatment planning systems and different delivery techniques, with the aim of optimizing the initial launch of this national head and neck cancer radiotherapy trial. Five benchmark patients meeting the eligibility criteria for NRG-HN002 were included in this study. Contours for target volumes and organ at risks were drawn according to the study guidelines. Two IMRT and two VMAT plans were developed for each patient using Varian Eclipse and the auto-planning module in Philips Pinnacle. Dose volume histograms of the plans were analyzed and compared using MIM software and tested against the compliance criteria of the protocol. All dosimetric compliance criteria were met using the two treatment planning systems and delivery techniques, except the maximum dose for PTV_4800 when it overlapped with higher dose PTVs. The coverage for the three PTVs (PTV_6000, PTV_5400 and PTV_4800) was achieved and also the PTV maximum doses were not exceeded in both IMRT and VMAT plans. The average maximum dose in all plans for SpinalCord_05, Spinal Cord and BrainStem_03 were 45 ± 4 Gy, 40 ± 5 Gy and 30 ± 9 Gy. Recommended dose values for other OARs (Parotid_Contra, larynx, pharynx, Sub Mandibular_Contra, Oral Cavity, Esophagus_Up, Mandible and NonPTV) were also achieved with minor deviations in very few occasions. The maximum dose of PTV_4800 criterion was removed from the protocol based on the results of this study. For radiotherapy-based clinical trials, this feasibility testing process is a model for reducing planning deviations and the necessity for amendments to the dosimetric criteria subsequent to activation.