How to compare two 3D dose distributions


This workspace (Gel dosimetry vs. TPS) provides several tools for a user to perform a comparison between two dose distribution 3D matrixes:

  • measured with the aid of a 3D dosimetry
  • calculated with the aid of a treatment planning system (TPS)

or between two 3D dose distributions obtained from different 3D dosimeters or TPS systems.


It is also possible to compare two dose distributions generated with the same dosimetric system and in addition, the user can analyse a single dose distribution generated by only one dosimetric system.


The workspace provides all the necessary tools for performing the comparison, which are typical for routine radiotherapy dosimetry, including:


- calculating the gamma index in 2D and 3D

- calculating the gamma angle in 2D and 3D

- calculating the difference in 2D and 3D

- calculating the correlation between 2 datasets

- calculating the histograms

- viewing of isodoses

- viewing of dose distributions on plane-by-plane basis

- viewing of dose distributions in 3D

- calculating data for a region of interest (ROI)


It should be noted that for the purpose of dose distribution measurements and the verification of measured dose distribution by a 3D dosimeter the GeVero Co. Verification phantom 1 and 2 could be used. They are adapted for inserting the FC65-G and CC04 ionisation chambers, respectively, to measure the dose at a point in the radiation scattering conditions provided by a 3D dosimeter.


The movie above presents how to compare easily two datasets: the measured 3D dose distribution with a polymer gel dosimeter and the calculated 3D dose distribution with the aid of TPS delivered to the polymer gel dosimeter.