Judy Nguyen MD, Presenter: Nothing to Disclose

Kara Davis MD, Abstract Co-Author: Nothing to Disclose

Erik Supratik Mittra MD, PhD, Abstract Co-Author: Nothing to Disclose

Neyssa Marina MD, Abstract Co-Author: Nothing to Disclose

Sanjiv S. Gambhir MD, PhD, Abstract Co-Author: Consultant, Arresto Bioscience, Inc Grant, Bayer AG Honorarium, Bayer AG Founder, Cellsight Technologies, Inc Stockholder, Cellsight Technologies, Inc Advisory Committee, Centella Biotechnologies, Inc Advisory Board, Endra, Inc, Stockholder, Endra, Inc Royalties, Reed Elsevier Advisory Board, Enlight, Inc Stockholder, Enlight, Inc Scientific Advisory Board, General Electric Company Grant, General Electric Company Scientific Advisory Board, ImaginAb, Inc Stockholder, ImaginAb, Inc Scientific Advisory Board, Lumen Therapeutics Stockholder, Stockholder, Lumen Therapeutics Scientific Advisory Board, MagArray, Inc Stockholder, MagArray, Inc Honorarium, Merck & Co, Inc Grant, Merck & Co, Inc Scientific Advisory Board, MILabs Consultant, NinePoint Medical, Inc Stockholder, NinePoint Medical, Inc Honorarium, Nordion, Inc Stockholder, Prolume, Ltd Scientific Advisory Board, RefleXion Medical, Inc Stockholder, RefleXion Medical, Inc Investor, RefleXion Medical, Inc Consultant, Spectrum Dynamics Ltd Stockholder, Spectrum Dynamics Ltd Scientific Advisory Board, Varian Medical Systems, Inc Scientific Advisory Board, VisualSonics Inc Stockholder, VisualSonics Inc

Andrei Iagaru MD, Abstract Co-Author: Advisory Board, Siemens AG Advisory Board, Spectrum Pharmaceuticals, Inc

99mTc-MDP has been the standard method for bone scintigraphy (BS) for more than 3 decades. The role of FDG PET/CT is proven in a variety of cancers for which it has changed the practice of oncology. There are few prospective studies comparing these 2 methods of detection of skeletal metastases in sarcoma patients. The purpose of this study was to compare FDG PET/CT and 99mTc-MDP BS in the detection of primary and/or metastatic osseous lesions.

48 consecutive patients with histopathological confirmation of Ewing’s sarcoma (EWS, n = 24) or other childhood sarcomas (rhabdomyosarcoma (n = 14), osteosarcoma (n = 5), synovial sarcoma (n = 3), spindle cell sarcoma (n = 1), high grade undifferentiated sarcoma (n = 1)) who had FDG PET/CT and 99mTc-MDP BS performed at our institution between 2003-2010 were included in this retrospective analysis. Only those patients who had these studies done within 1 month of each other were included. There were 24 males and 24 females, with an average age at time of diagnosis of 15.18 ± 8.1 years. Sensitivities and specificities were calculated for detection of osseous malignant lesions.

No differences in sensitivity or specificity between the PET/CT and BS were observed in these cohorts, except for detection of bone metastases from non-EWS where PET performed better than BS. PET/CT also detected disease outside the skeleton in 29.2% of EWS patients and 62.5% of non-EWS patients. In EWS, BS was 85.7% sensitive and 94.4% specific for detection of the primary lesions (n=22), while PET was 85.7% sensitive and 88.9% specific. For detection of osseous metastases (n=24), BS was 60% sensitive and 93.1% specific, while PET was 66.7% sensitive and 96.4% specific. In non-EWS, BS was 78.6% sensitive and 100% specific for detection of the primary osseous lesions (n=11), while PET was 76.9% sensitive and 100% specific. For detection of osseous metastases (n=25), BS was 33.3% sensitive and 97.4% specific, while PET was 66.7% sensitive and 100% specific.

While this is a small cohort and the results need to be confirmed in larger studies, it appears that FDG PET/CT may successfully provide similar information regarding skeletal lesions as BS in patients with sarcomas. In addition, FDG PET/CT detected disease outside of the skeleton in a significant number of EWS and non-EWS.

FDG PET/CT provides similar information regarding skeletal lesions as BS.

Nguyen, J, Davis, K, Mittra, E, Marina, N, Gambhir, S, Iagaru, A, Clinical Utility of 18F FDG PET/CT and 99mTc MDP Bone Scintigraphy in Patients with Ewings Sarcoma and Other Sarcomas.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11007319.html