Purpose: To demonstrate the efficacy of a novel and open source tool, “Plan n Check,” for automated creation of head-and-neck Volumetric Modulated Arc Therapy (VMAT) radiotherapy plans in Varian Eclipse™.
Methods: The Eclipse Scripting Application Programming Interface was used to develop a binary script which runs within Eclipse™, reading and operating on patient data. Plan n Check creates dual concentric arcs centred on the primary target volume with a 60° collimator angle difference aligned with the patient’s superior-inferior axis. Collimator jaws are automatically adjusted to adequately encompass target volumes. Standard institutional dose constraints are automatically applied to relevant structures which can be verified and overridden by the planner if needed. Optimization structures are automatically created where regions-of-interest overlap planning target volumes, excluding higher-priority tissues (e.g., nervous system). To fine-tune optimization objectives, N preliminary optimization cycle iterations followed by automatic constraint-checking and updating of objective penalties take place before proceeding with full VMAT optimization for 4 additional optimization cycles.
Results: Plan n Check created treatment plans conforming to institutional best-practices and standards-of-care. Plans optimized with N = 1 and N = 2 met all institutional constraints, while plans optimized without preliminary iterations resulted in constraint violations for all but one patient (median: 2 violations per plan).
Conclusion: Plan n Check is an open source tool for automating VMAT treatment planning in Varian Eclipse™. Use of preliminary optimization cycle iterations improves clinical constraint satisfaction without requiring any additional effort from the planner. Source code is freely available online.