OBJECTIVE: In a prior study, high resolution ultrasound (US) was shown to be accurate for evaluating rib metastasis detected on bone scan.
However, that study did not address the specific US appearance typical of osteoblastic rib metastasis. Our objective was to determine the specific US imaging appearance of osteoblastic prostate carcinoma rib metastasis using osteolytic renal cell carcinoma rib metastasis as a comparison group.
MATERIALS AND METHODS: The Institutional Review Board approval and informed consent were obtained for this prospective feasibility study. We performed high resolution US of 16 rib metastases in 4 patients with prostate carcinoma metastases and compared them to 8 rib metastases in 3 male patients with renal cell carcinoma. All patients had rib metastases proven by radiographs and computed tomography (CT). High resolution US scanning was performed by a musculoskeletal radiologist using a 12-5MHz linear-array transducer. Transverse and longitudinal scans were obtained of each rib metastasis.
RESULTS: All 16 prostate carcinoma metastases demonstrated mild cortical irregularity of the superficial surface of the rib without associated soft tissue mass, cortical disruption, or bone destruction. 7 of 8 (88%) renal cell carcinoma rib metastases demonstrated cortical disruption or extensive bone destruction without soft tissue mass. One of 8 (12%) renal cell carcinoma rib metastases demonstrated only minimal superficial cortical irregularity at the site of a healed metastasis.
CONCLUSION: Osteoblastic prostate carcinoma rib metastases have a distinctive appearance on US. Our success in visualizing these lesions suggests that US may be a useful tool to characterize isolated rib abnormalities seen on a bone scan in high-risk prostate cancer patients who are being evaluated for curative surgery or radiation treatment.
Written by:
Lee KS, De Smet AA, Liu G, Staab MJ. Are you the author?
University of Wisconsin School of Medicine and Public Health, Department of Radiology, 600 Highland Avenue CSC E3/311, Madison, WI 53792-3252.
Reference: Urol Oncol. 2013 Mar 4. pii: S1078-1439(12)00294-3.
doi: 10.1016/j.urolonc.2012.08.014
PubMed Abstract
PMID: 23481369
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