InverseArc is a universal treatment conversion tool that reproduces the dose characteristics of any given treatment plan with a volumetric modulated arc treatment (VMAT) technique. It pairs the established gold standard of planning, like IMRT, with efficient delivery and unlocks the potential of volumetric modulated arc treatments for most linear accelerators.

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VMAT-ification based on DVH and Dose Distribution


Based on any given treatment plan in DICOM RT format, InverseArc generates a volumetric modulated arc (VMAT) plan that matches the dose volume histogram and dose distribution characteristics of the reference plan. The software automatically detects the organ type, sets the constraints based on the DVH of the original plan and optimizes the machine parameters required to deliver the corresponding VMAT plan.

  • Compatible with any treatment planning system that supports DICOM RT
  • Streamlined and straightforward workflow via highly automated software
  • Mimics the dose volume histogram and dose distribution of the original reference plan
  • Advanced collapsed cone dose algorithm
InverseArc generates volumetric modulated arc plans with fixed or modulated dose rate and gantry speed


The software optimizes the plan either with a fixed or modulated dose depending on linac capabilities. The fixed dose option optimizes leaf position while ensuring that every segment receives the same dose, resulting in a constant dose rate and gantry speed during delivery. The dose modulation option optimizes both the leaf position and the dose per segment, which results in a treatment with simultaneous modulation of both the dose rate and the gantry speed.

  • Enables most linacs to perform volumetric modulated arc therapies¹ without necessary hardware upgrades
  • Choose between fixed dose or dose modulation during optimization
  • Zero downtime installation
  • Straightforward implementation and quality assurance
Shift patients between different linear accelerators in case of technical malfunctions.


With InverseArc, VMAT becomes available on a large number of treatment devices, also allowing for shifting of patients between treatment machines. This becomes useful for departments with several linear accelerator models and a multitude of treatment planning solutions, especially in cases of downtime.

  • Anticipate technical failures with a treatment plan backup solution
  • Exchange patients effortlessly between different linear accelerators and even Tomotherapy²
  • Deliver Tomotherapy plans with a conventional linear accelerator
Benchmark your practice by comparing state-of-art radiosurgery plans with volumetric modulated arc therapy treatments


InverseArc is designed to complement current iPlan® RT treatment offerings and automatically transfers organ types (PTV and OAR), constraints and prescription from the original iPlan RT treatment plan. It allows for continued planning with well-established IMRT or HybridArc protocols and helps to place the focus on plan quality, while InverseArc optimizes the delivery.

  • iPlan prescription details like organ types (PTV, OAR) or constraints are automatically detected
  • Set planning creativity free from delivery prerequisites
  • No additional commissioning measurements for existing iPlan RT Monte Carlo beam profiles
Compare and select the most optimal plan for each individual patient


InverseArc enables easy evaluation of established treatment approaches against the newly generated plan. A comprehensive view featuring side-by-side dose comparisons, dose volume histograms, and a dose difference map facilitate thorough plan comparison and informed decision-making about the most optimal plan for each individual patient.

  • Compare and select the optimal treatment solution for every individual patient
  • Compare state-of-the-art radiosurgery plans with volumetric modulated arc therapy treatments
  • Dose Volume Histogram and side-by-side dose comparisons of original and new treatment plan
  • Unique dose difference view to easily detect significant dose differences


Requires a linear accelerator with dynamic arc capabilities.


No plans for Tomotherapy can be created.



Product developed in cooperation with RaySearch.