Srinath Sampath MD, PhD, Presenter: Nothing to Disclose

Srihari C Sampath MD, PhD, Abstract Co-Author: Nothing to Disclose

Amelie Margarete Lutz MD, Abstract Co-Author: Nothing to Disclose

Juergen Karl Willmann MD, Abstract Co-Author: Nothing to Disclose

Erik Supratik Mittra MD, PhD, 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

FDG PET/CT is well established in clinical practice for the initial cancer staging and the subsequent monitoring of response to therapy. Sodium fluorine-18 (NaF) can be used as a skeletal tracer in current PET/CT scanners. The combined administration of NaF and FDG in a single PET/CT scan may improve patient convenience, while reducing healthcare costs. However, this novel imaging method has not been compared to CT alone for the detection of skeletal metastases.

This is a retrospective review of 43 patients (32 men and 11 women, 19-84 year-old) with proven malignancy, who had separate NaF PET/CT, FDG PET/CT and combined NaF/FDG PET/CT scans (total of 3 scans per patient). The 3 PET/CT scans were sequentially performed within a 2 weeks interval for each patient. A direct comparison for each detected skeletal metastasis was performed among the 3 scans and CT alone.

21 exams identified osseous metastases on at least 1 of the 4 (NaF PET, FDG PET, NaF/FDG PET and CT) imaging modalities (49% of total exams). The combined NaF/FDG PET compared favorably with individual NaF PET and FDG PET, as all 17 exams positive for osseous metastasis on either NaF or FDG PET were also positive on the combined NaF/FDG scan. In contrast, when CT was interpreted in the absence of PET correlation, 6 exams (35%) were incorrectly considered negative, with 4 of these 6 false negatives detected only on NaF PET and combined NaF/FDG PET. Of these 6 ‘PET-positive/CT-negative’ exams, CT abnormalities were in fact noted by the reviewers in 5 cases, but were interpreted as either benign or likely benign. Finally, 7 of 11 exams in which CT detected lesions not seen on FDG PET were subsequently scored positive for metastatic disease by NaF PET and combined NaF/FDG PET.

The combined NaF/FDG PET/CT detects more osseous metastases than CT alone, without loss of sensitivity in comparison to separate FDG PET or NaF PET. The simultaneous use of NaF and FDG PET contributed greatly to the degree of concordance between scintigraphy and radiography. These findings provide a clinically relevant rationale for the use of combined NaF/FDG PET/CT in the management of oncologic patients and should be further evaluated in larger cohorts.

The simultaneous use of NaF and FDG PET contributes greatly to the degree of concordance between scintigraphy and radiography.

Sampath, S, Sampath, S, Lutz, A, Willmann, J, Mittra, E, Gambhir, S, Iagaru, A, Value of Combined 18F NaF and 18F FDG PET/CT vs CT Alone for Evaluation of Osseous Malignancy.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11009575.html