In this article, our goal is to compare the TMR10 and convolution dose calculation algorithm in GammaPlan used in stereotactic radiosurgery (SRS) treatments with Gamma Knife and to assess if the algorithms produce clinically significant differences.

Treatment plans were analysed from ten patients who have undergone Gamma Knife SRS treatments. Patient plans were retrospectively recalculated using Lesksell GammaPlan 10 treatment software utilising the TMR10 and convolution dose calculation algorithms in order to create a paired dataset for comparison. Evaluation was based on the dose volume histogram (parameters of minimum, mean, maximum and integral doses.

The ratios of average integral doses calculated by the convolution dose calculation algorithm to the average integral doses calculated by the TMR10 algorithm are 0·997 for the target (p=0·028), 1·048 (p=0·48) for the skull and 1·005 (p=0·68) for the brainstem.

Although doses calculated with the convolution algorithm resulted in slightly higher mean integral doses for the brainstem and skull critical structures when compared to that of TMR10 doses, these results were not statistically or clinically significant. Thus we continue to use the TMR10 algorithm at our clinic.