Feasibility Study of Three-dimensional Reformatted PET/CT Imaging in Musculoskeletal Tumors

Introduction: Three-dimensional (3-D) displays for medical imaging is emerging field and very promising tools for diagnosis, therapy response and detection of tumor recurrence. Morphological criteria for therapy response (CR, PR, SD, PD) have been established with RECIST (Response evaluation criteria in solid tumors). With adoption of metabolic imaging with PET/CT, particularly with F-18-FDG in initial staging and follow up of tumors, there appears to be a need to modify these criteria not only on morphological imaging modalities like CT, but also on tumor metabolism parameters, like SUV (standardized uptake value) as measured by PET. Furthermore, 3-D imaging taken from PET/CT can be an excellent approach to assess the tumor response after appropriate therapy. We will evaluate the feasibility of TrueD (Siemens) imaging of F-18-FDG PET/CT for both initial staging and post-therapeutic follow-up in patients with musculoskeletal tumors. One-hundred seventy-three patients with musculoskeletal tumors were enrolled in this study. Seventy-two osteosarcoma, 16 liposarcoma, 16 chondrosarcoma, 10 fibrosarcoma, 10 malignant fibrous histiocytoma (MFH), 8 soft tissue sarcoma, 8 melanoma, 6 leiomyosarcoma, 6 synovial sarcoma, 5 Ewing sarcoma and 16 other tumors are included. Two technologists performed laborious job using TrueD software in patients with more than two PET/CT scans under the supervision of Nuclear Medicine Physician. Among many galleries, the most optimal palette applied according to anatomic location of the tumors (muscle or bone) and other characteristics. Monitoring of tumor response to therapy is very easy to assess using these TrueD PET/CT images. The recent development of three-dimensional image processing will lead medical imaging to full definition volumetric display for clinician as well as patients themselves. 3-D images can provide easy understanding of the status of oncologic abnormality for doctors and patients. VOIs (volume of interests) of 2 or 3 time points display can be saved and exported as powerful and comprehensive images through the any PACS systems. Further research to get all the quantitative data including volume and SUV etc. by clicking on 3-D images is under consideration.