ESTRO 2021 Abstract Book

S1518

ESTRO 2021

The highest CV mean values were observed for PTV ROI and for the GLSZM features families. On the other hand, the lowest CV mean values have been found for RING ROI for the GLCM features family. The total number of features with CV>1 is 679 (0.15%). As regards of feature family, STAT and GLSZ showed the higher percentage of CV>1. The highest mean ICC values (0.706) belonged to PTVs, considering all the different pixel spacing values. None of the 17 th P n had an ICC cumulative value higher than 9.4 on a maximum score of 12 highlights a relative disagreement among the CVs values as shown in figure 2. For PTV ROIs, ICC value was higher when the pixel spacing was closer the planning CT one.

The most unstable dosomics features are cluster shade, joint maximum (GLCM features family); large zone high grey level emphasis, zone size variance and small zone low grey level emphasis (GLSZ family); intensity kurtosis and intensity skewness for the (STAT family). Conclusion The stability of dosomics features extraction on dose cube pixel spacing has been evaluated for a representative clinical dose distribution case mix. The observed variation of the dosomic features is not negligible, therefore we suggest always to report information about grid resolution, algorithm dose calculation and dose cube pixel spacing in dosomic studies.