Multiple and solitary skeletal muscle metastases on 18F-FDG PET/CT imaging. Issue 11 (November 2015)

• Record Type: Journal Article
• Authors: Nocuń, Anna; Chrapko, Beata
• Is Part Of: Nuclear medicine communications. Volume 36:Issue 11(2015:Nov.)
• Publication Date: 2015-11
• Subjects: Nuclear medicine -- Periodicals; 616.07575
• DOI: 10.1097/MNM.0000000000000368
• Languages: English
• ISSNs: 0143-3636

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Objective</title> <p>The aim of this study was to investigate the features and patterns of skeletal muscle metastases (SMM) detected with <sup>18</sup>F-fluorodeoxyglucose (<sup>18</sup>F-FDG) PET/computed tomography (PET/CT).</p> </sec> <sec> <title>Participants and methods</title> <p>Our database was analyzed for patients with pathologically proven malignancy, who underwent <sup>18</sup>F-FDG PET/CT in our institution. The patients with SMM were included in the study group on the basis of the final diagnosis confirmed by follow-up or histopathology. Images were acquired using a PET/CT system Biograph mCT S(64)-4R. CT was performed without contrast enhancement.</p> </sec> <sec> <title>Results</title> <p>The selected group included 31 patients (1.7% of the database, which consisted of 1805 patients). A total of 233 lesions were found. The prevalence of SMM evaluated in specific primary malignancies was the highest in melanoma (6.9%), followed by carcinoma of unknown primary (4.4%), colorectal cancer (4.1%) and lung cancer (2.8%). Three patterns of skeletal muscle metastatic involvement were observed: multiple SMM accompanied by other metastases (64.5%), solitary lesion associated with other metastases (29%) and isolated intramuscular lesions (two cases, 6.5%). Isolated SMM represented recurrence of the malignant disease. In patients with extraskeletal metastases, solitary or multiple SMM did not affect tumor staging.</p> </sec> <sec> <title>Conclusion</title> <p>Solitary SMM are less common than multiple on <sup>18</sup>F-FDG PET/CT imaging. SMM are usually associated with other metastases and do not affect tumor staging. The cases of isolated SMM are very rare. Nevertheless, in patients with a diagnosis of malignant disease, a solitary, <sup>18</sup>F-FDG avid intramuscular focus should be suspected to represent metastasis.</p> </sec> </abstract>