Georg Homann MD, Presenter: Nothing to Disclose

Deedar Farhad Mustafa MD, BEng, Abstract Co-Author: Nothing to Disclose

Juergen Hetzel, Abstract Co-Author: Nothing to Disclose

Werner Spengler MD, Abstract Co-Author: Nothing to Disclose

Claus Detlef Claussen MD, Abstract Co-Author: Nothing to Disclose

Konstantin Nikolaou MD, Abstract Co-Author: Speakers Bureau, Siemens AG Speakers Bureau, Bracco Group Speakers Bureau, Bayer AG

Marius Horger MD, Abstract Co-Author: Nothing to Disclose

To evaluate the performance of a dedicated CT-software called "bone reading" generating rib unfolded images for improved detection of rib metastases in patients with lung cancer and suspicious focal uptake on 18F-FDG-PET/CT in terms of sensitivity and specificity and reading time as compared with 5mm and 1mm axial CT-images.

50 consecutive patients with lung cancer that underwent 18F-FDG-PET/CT and chest-CT scanning between 2011 and 2014 at our institution were retrospectively analyzed. Chest-CT scans with 5mm and 1mm slice thickness were interpreted blindly and separately focusing on detection of rib metastases (location, number, cortical vs. medullary, osteolytic vs. osteoblastic [sclerotic]). Subsequent image analysis of unfolded 1mm based CT rib images was performed. This image data set can be spatially rotated (screwed) for optimized multi-angled views. Finally, combined FDG-PET and “bone reading” image analysis was performed and correlated with the other results. Osteolytic and mixed osteolytic-osteoblastic, FDG-PET+ lesions were considered true positive whereas suspicious osteoblastic lesions had to be confirmed at follow up. Follow-up chest-CT was present in all patients.

From a total of 45 rib metastases at follow-up, 26 rib lesions were found positive on FDG-PET/CT. 9 lesions were osteolytic, 9 were mixed osteolytic-osteoblastic whereas 27 were sclerotic. On patient-based analysis, CT (5mm), CT (1mm) and CT (1mm-"bone reading") yielded a sensitivity, specificity and accuracy of 0.7/0.85/0.94[5mm], 0.8/0.84/0.96 [1 mm] and 1.0/0.8/0.98 ["bone reading"], respectively. On lesion-based analysis, the accuracy of the three evaluations was 0.34/0.66/0.93, respectively. Reading time for 5mm/1mm axial images and “unfolded images” was 49.8 [± 30s (5mm/1mm)] and 18.7 [± 5.3 s (1mm-"bone reading")], respectively.

The use of the "unfolded rib" software improves detection of rib metastases in patients with lung cancer as compared to standard CT reading.

Early detection of metastases is crucial in lung carcinoma staging. Especially in complex anatomical regions as the ribs the "unfolded rib" software improves the detection rate significantly.

Homann, G, Mustafa, D, Hetzel, J, Spengler, W, Claussen, C, Nikolaou, K, Horger, M, Improved Detection of Bone Metastases from Lung Cancer in the Thoracic Cage Using 5mm and 1mm axial CT Images vs. a New CT-software Generating a Rib Unfolding Image Set: Comparison with Standard 18F-FDG-PET/CT.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007807.html