Room: AAPM ePoster Library
To provide a basic comparison of two commercially available software platforms which could be used to perform dosimetric analysis of Y-90 Bremsstrahlung imaging in SIRT.
Retrospective dosimetric analysis of post treatment Bremsstrahlung Y-90 SPECT/CT images was performed in 34 patients who received SIRT using two commercially available software packages. For a direct comparison, the structures segmented by the radiation oncologist were used in both systems. The 3D local deposition model (LDM) was used for dose calculation using only the counts contained in the liver. Patients received an average dose of 1.9 GBq (0.3-4.9 GBq). To compare the systems over a range of dose levels, we obtained the GTV maximum and mean dose along with the GTV D95%, D50% and D2% from dose volume histograms. The correlation coefficients between the datasets were calculated.
A strong linear correlation was found across all dose metrics assessed. The maximum dose and D2% showed the strongest correlations at 0.995 and 0.997, respectively. The D95% showed the lowest correlation at 0.957. The mean dose and D50% showed strong correlations as well (0.989 and 0.973, respectively).
Two commercially available software packages that perform 3D voxel-based dosimetry for Y90 SIRT studies were compared using a clinical patient data cohort. Both are useful in providing quantitative analysis of the delivered dose distribution to assist with clinical decision making. The results demonstrated a high degree of similarity particularly when taking into consideration several confounding factors and limitations involved in the process. It is very encouraging to report that such software platforms can be utilized clinically with a degree of confidence that they provide very similar output. Further validation may be warranted for the very specific utilization of such software for clinical dosimetry.