Learning objectives. Background. Imaging findings OR Procedure details

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1 A comparison of limited MRI of the axial skeleton (lumbar spine and pelvic bones) with whole body bone scintigraphy in detecting bone metastasis from prostate carcinoma Poster No.: C-659 Congress: ECR 2009 Type: Educational Exhibit Topic: Musculoskeletal Authors: R. Kenningham, R. Beable, A. Rajesh, K. Mulcahy; Leicester/UK DOI: /ecr2009/C-659 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 5

2 Learning objectives MRI is more sensitive than bone scintigraphy for detecting bone metastasis Limited MRI of the axial skeleton detects as many cases of metastasis as whole body scintigraphy Background Whole body bone scintigraphy is the standard modality used to stage bone metastasis in prostate carcinoma. Imaging of the skeleton is usually performed in individuals thought to be high risk for metastasis on clinical grounds including the Gleason score and the PSA value. Bone scintigraphy is able image the entire skeleton but gives limited anatominal information and is dependant on active bone turnover. Pathological areas of increased activity (pelvic bones) may be masked by physiological areas of increased activity (bladder). MRI of the axial skeleton is more sensitive in detecting metastasis than bone scan as it is able to detect marrow infiltration before bone destruction or formation has occured (1). MRI is also widely used to further characterise indeterminate lesions seen on bone scan. Published comparisons of MRI and bone scintigraphy in detection of prostate metastasis have been only of small series of patients and MRI protocols included the axial and large parts of the appendicular skeleton(2,3,4). The protocol for local staging at this institution involves imaging the retroperitoneum and consequently images of the lower thoracic and lumbar spine are also obtained. Combined with the pelvic bones included on the prostatic scan this constitutes a significant component of the axial skeleton. The aim of this study was to compare the detection of bone metastasis between bone scintigraphy and a limited range skeletal MRI scan. Imaging findings OR Procedure details A retrospective review of patients with histologically proven prostate carcinoma over a two year period between and was performed at our institution. 241 patients had both MRI of the prostate and bone scan within one month of each other to allow a comparison to be made. Patients were imaged based on both biochemical and physical findings according to local protocols and patients with PSA values below 8ng/ ml were included if symptoms suggested bone disease. Page 2 of 5

3 Of 241 eligible patients there was agreement between the bone scan and MRI in 226 cases. In 4 cases the MRI was positive for bone metastasis but the bone scan was not. Three lesions were in the the thoracolumbar spine and one in the pelvis (Figure 1). Fig.: Whole body bone scan with no abnormal uptake and sagittal T1 weighted MRI of the lumbar spine showing a metastasis in the T12 vertebral body (arrow). In 4 cases the bone scan was positive but the MRI was not. Two lesions were outside the coverage of the MRI ( skull and ribs). Two lesions were covered and detected on MRI but not thought typical of metastasis on MRI. In seven cases the bone scan was considered equivocal for bone metastasis. In three of these cases the original prostate MRI protocol confirmed these lesions as metastasis (Figures 2 and 3). Two cases went on to have regional MRI showing a benign cause of increased uptake on the bone scan. Two further equivocal scans have no follow up. Page 3 of 5

4 Fig.: Whole body scintigram suggests possible metastasis or bladder diverticulum - confirmed as a metastasis on the T1 weighted sequence MRI scan. Fig.: Whole body scintigram showing intense increased uptake in the L5 vertebral body suspicious of metastasis. Sagittal T1 and STIR weighted MRI of the lumbar spine with heterogenous increased T1 signal intensity and no abnormality on STIR not typical of metastasis and suggesting Pagets disease Page 4 of 5

5 Conclusion Limited range MRI of the axial skeleton (lumbar spine and pelvic bones) detected as many cases of bone metastasis as whole body scintigraphy. MRI is helpful in equivocal scintigraphy scans. Personal Information References 1. Rydh A, Lundblad M, Ahlstrom K, Tavelin B, Stattin P. MRI of the skeleton in Prostate cancer staging. Scand J Urol Nephrol 2003; 37: Freedman GM, Negendank WG, Hudes GR, Shaer AH, Hanks GE. Preliminary results of a bone marrow imaging protocol for patients with high risk prostate cancer. Urology 1999; 54: Eustace S, Tello R, Decarvalho V et al. A comparison of whole body turbo short tau inversion recovery MR imaging and plain technetium 99m methylene diphosphonate scintigraphy in the evaluation of patients with suspected skeletal metastasis. AJR 1997; 196: Lauenstien TC et al. Whole body MRI using a rolling table platform for the detection of bone metastasis. Eur Radiology 2002; 12: Page 5 of 5