A study on the tumor volume computation between different 3D treatment planning systems in radiotherapy

Background: Tumor volume plays a crucial role in the survival and local control of the patients treated with radiotherapy. The dose volume histogram also depends on the accuracy of the tumor delineation.
Aims: The main aim is to study the variation observed in the computation of the target volume with different treatment planning systems and treatment sites.
Materials and Methods: Sixty patients of different treatment sites which include brain, retinoblastoma, head and neck, lung, gall bladder, liver, anal canal etc, were selected for this study. The tumor volume was delineated on the Eclipse treatment planning systems and CT datasets and DICOM-RT structure sets were transferred to Pinnacle, Oncentra, Plato, Precise, Ergo+, and Tomocon contouring workstations. The recomputed volume from these planning systems was compared with the reference volume obtained from Eclipse. Similarly, the accuracy in generating PTV from CTV was also assessed with different planning systems for 5 and 10 mm.
Statistical Analysis Used: SPSS 10.0 was used for analysis.
Results: The overall comparison of the volume with different planning systems showed that Pinnacle calculated relatively larger volume followed by Plato as compared to Eclipse, whereas TOMOCON, Ergo +, and Oncentra showed reduced volume. As far as the variation in CTV to PTV volume is concerned, pinnacle showed a relatively higher volume as compared to the Eclipse planning systems.
Conclusion: The study shows that all the treatment planning systems showed variation in computing the tumor volume and the CTV to PTV generation also varied with the planning systems.

Keywords
CT scanning, delineation, DICOM, treatment planning systems, tumor volume