Comparative evaluation of serial hybrid imaging studies for quantitative assessment of therapeutic response

Abstract

720

Learning Objectives: Use of software tools for enhanced quantitative evaluation of multi timepoint PET/CT or SPECT.CT studies.

Abstract (summary): Software solutions aimed at improving efficiency of interpretation of fused datasets of PET/CT and SPECT.CT studies have made a major impact on diagnosis and management of cancer. A software was developed for this purpose capable of automatic co-registration of NM and CT data of single or multiple studies with automatic registration of two sequential studies to provide visual alignment and landmark matching for efficient real time image correlation. This enables efficient visual and quantitative analysis of pre and post treatment studies involving chemo or radiotherapy as well as standard follow up to assess volume and SUV changes of lesions across different time points. The software tool enables automatic and manual generation of VOI based on SUV thresholding for accurate estimation of lesion volume and SUV levels in pre treatment studies and is capable of exporting them in Dicom RT format for radiation therapy treatment planning. VOIs created on pre treatment studies can also be applied on the corresponding images of post treatment studies for monitoring therapeutic response. It is also possible to share identical isocontour areas between studies for exact quantitiative image comparison. Respiratory and Cardiac Gated PET and CT studies can also be visualized both indivially and as fused datasets both as single or aligned sequential studies with visualization of respiratory motion and estimation of lesion volume and generation of VOI for RT planning at a specific phase of the respiratory cycle of PET and CT as well as fused data. Comparative visualization & volume estimation of lesions using identical or SUV threshold adjusted VOI of pre and post therapy gated studies for evaluation of therapeutic efficacy possible. Volume rendering of fused datasets along with comparative evaluation of VRT images across multiple time point studies help optimum estimation of change in lesion size and metabolism. Reporting formats for efficient lesion SUV and volume comparison based quantitative reporting along with ease of use and accuracy of registration of multi timepoint studies offer major step forward to improvement in workflow efficiency in hybrid imaging based cancer management.

Research Support (if any): Software solutions developed by oncology application development team of Siemens Medical Solutions.