MRI new gold standard for finding metastases?

[JimJimJimJim]

Jim Marshall (not a doctor) said ...

A year ago we reported a 2007 study that said that an axial MRI scan was better than the existing bone scan at detecting bone metastases in prostate cancer.

You can see that here:

MRI of spine best identifier of metastases

Basically, that study reported that the current practice of looking for bone metastases by:

• bone scan, then
  
• x-rays of unclear areas,
  
• then MRI to resolve any spots still uncertain.
  

is improved if you go straight to MRI of the axial spine.

That paper did not look at the second part of current practice: looking for metastases to lymph nodes by:

• CT scan.
  

The paper below (published this month) does do just that, concluding:

• MRI is better than bone scan for metastases to bone.
  
• MRI is equal to CT for metastases to lymph nodes.
  

It suggests that MRI may be the new 'gold standard' in looking for metastases in men at high risk of metastases.

It then poses the questions - will that improve results for men, and at what cost?

... end Jim

Jim Marshall (not a doctor) said ...

Bone scan, CT scan MRI scan are different ways of taking pictures inside your body.

WBMRI = Whole Body MRI scan

Currently in Australia (July 2012) MRI is not covered by public health or private insurance bodies.

Costs I heard a Radiation Oncologist quote last week were $300-$600 for an MRI scan.

... end Jim

Eur Urol. 2012 Jul;62(1):68-75. Epub 2012 Feb 17.

Can whole-body magnetic resonance imaging with diffusion-weighted imaging replace Tc 99m bone scanning and computed tomography for single-step detection of metastases in patients with high-risk prostate cancer?

Lecouvet FE, El Mouedden J, Collette L, Coche E, Danse E, Jamar F, Machiels JP, Vande Berg B, Omoumi P, Tombal B.

Source

Department of Radiology, Cliniques universitaires Saint Luc, Université catholique de Louvain, Brussels, Belgium. frederic.lecouvet@uclouvain.be

Abstract

BACKGROUND:

Technetium Tc 99m bone scintigraphy (BS) and contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) of the pelvis and abdomen are universally recommended for detecting prostate cancer (PCa) metastases in cancer of all stages. However, this two-step approach has limited sensitivity and specificity.

OBJECTIVE:

Evaluate the diagnostic accuracy of whole-body MRI (WBMRI) as a one-step screening test for PCa metastases.

DESIGN, SETTING, AND PARTICIPANTS:

One hundred consecutive PCa patients at high risk for metastases prospectively underwent WBMRI, CT, and BS completed with targeted x-rays (BS/TXR) in case of equivocal BS. Four independent reviewers reviewed the images.

MEASUREMENTS:

This study compares the diagnostic performance of WBMRI, CT, BS, and BS/TXR in detecting PCa metastases using area under the curve (AUC) receiver operator characteristics. A best valuable comparator (BVC) approach was used to adjudicate final metastatic status in the absence of pathologic evaluation.

RESULTS AND LIMITATIONS:

Based on the BVC, 68 patients had metastases. The sensitivity of BS/TXR and WBMRI for detecting bone metastases was 86% and 98-100%, respectively (p<0.04), and specificity was 98% and 98-100%, respectively. The first and second WBMRI readers respectively identified bone metastases in 7 and 8 of 55 patients with negative BS/TXR. The sensitivity of CT and WBMRI for detecting enlarged lymph nodes was similar, at 77-82% for both; specificity was 95-96% and 96-98%, respectively. The sensitivity of the combination of BS/TXR plus CT and WBMRI for detecting bone metastases and/or enlarged lymph nodes was 84% and 91-94%, respectively (p=0.03-0.10); specificities were 94-97% and 91-96%, respectively. The 95% confidence interval of the difference between the AUC of the worst WBMRI reading and the AUC of any of the BS/TXR plus CT lay within the noninferiority margin of ±10% AUC.

CONCLUSIONS:

WBMRI outperforms BS/TXR in detecting bone metastases and performs as well as CT for enlarged lymph node evaluation. WBMRI can replace the current multimodality metastatic work-up for the concurrent evaluation of bones and lymph nodes in high-risk PCa patients.

Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Comment in

Whole-body magnetic resonance imaging and prostate cancer metastases: a new gold standard of detection, but does it help us and at what cost? [Eur Urol. 2012]

PMID: 22366187

This extract can be found on http://PubMed.com, and is in the public domain.

On PubMed.com there will be a link to the full paper (often $30, sometimes free).

Any highlighting (except the title) is not by the author, but by Jim Marshall.

Jim is not a doctor.