Diagnostic accuracy of preoperative magnetic resonance imaging in predicting curative resection of rectal cancer: prospective observational studyBMJ 2006; 333 doi: https://doi.org/10.1136/bmj.38937.646400.55 (Published 12 October 2006) Cite this as: BMJ 2006;333:779
- MERCURY Study Group ()
- Correspondence to: G Brown, Royal Marsden Hospital, Surrey SM2 5PT
- Accepted 2 August 2006
Objective To assess the accuracy of preoperative staging of rectal cancer with magnetic resonance imaging to predict surgical circumferential resection margins.
Design Prospective observational study of rectal cancers treated by colorectal multidisciplinary teams between January 2002 and October 2003.
Setting 11 colorectal units in four European countries.
Participants 408 consecutive patients presenting with all stages of rectal cancer and undergoing magnetic resonance imaging before total mesorectal excision surgery and histopathological assessment of the surgical specimen.
Main outcome measures Accuracy of magnetic resonance imaging in predicting a curative resection based on the histological yardstick of presence or absence of tumour at the margins of the specimen.
Results 354 of the 408 patients had a clear circumferential resection margin (87%, 95% confidence interval 83% to 90%). Specificity for prediction of a clear margin by magnetic resonance imaging was 92% (327/354, 90% to 95%). High resolution scans were technically satisfactory in 93% (379/408). Surgical specimens were histopathologically graded as complete or moderate in 80% (328/408), and the median lymph node harvest was 12 (range 0-49). Magnetic resonance imaging predicted clear margins in 349 patients. At surgery 327 had clear margins (94%, 91% to 96%).
Conclusion High resolution magnetic resonance imaging accurately predicts whether the surgical resection margins will be clear or affected by tumour. This technique can be reproduced accurately in multiple centres to predict curative resection and warns the multidisciplinary team of potential failure of surgery, thus enabling selection of patients for preoperative treatment.
A list of the members of the MERCURY Study Group, details of imaging sequences, and a copy of the proforma can be found on bmj.com.
We thank all the radiologists, pathologists, surgeons, and nurse specialists who were members of the MERCURY Study Group and were responsible for conception and design of the study and collection of data (see bmj.com for details). The following hospitals took part in this study: Pelican Cancer Foundation, The Ark, North Hampshire Hospital; Royal Marsden Hospital Colorectal Network, Royal Marsden Hospital; St Helier NHS Trust; Mayday University Hospital; North Hampshire Hospital; Leeds Hospitals Teaching Hospitals, Leeds General Infirmary; St James's University Hospital; Norwegian Radium Hospital; Frimley Park Hospital; Ashford St Peters Hospital; Krankenhaus im Friedrichshain; Llandough Hospital; Karolinska University Institute. The Pelican Cancer Foundation supported the trial throughout.
Contributors G Brown was responsible for conception and design of the study, collected and interpreted data, drafted the manuscript, and is guarantor. I R Daniels was responsible for the conception and design of the study, collected and interpreted data, coordinated the study and critically edited the manuscript. R J Heald, P Quirke, L Blomqvist, D Sebag-Montefiore, B J Moran, T Holm, and J Strassbourg were responsible for conception and design of the study, collected data, and critically edited the manuscript. A R Norman was responsible for conception and statistical design of the study and carried out the statistical analysis. P D Peppercorn was responsible for conception and design of the study and collection of data. S E Fisher was responsible for collection of data. B Mason was responsible for assistance in drafting the manuscript.
Funding Wessex Cancer Trust and Siemens Medical, through the Pelican Foundation.
Competing interests None declared.
Ethical approval The south east multi-centre research and ethics committee in the UK and local institutional ethics review boards in Oslo, Stockholm, and Berlin approved the study. It was adopted within the United Kingdom National Cancer Research Network Portfolio of Studies.