Aims and objectives
To investigate the potential benefit of ultrahigh b-value DWI in rectal cancer by qualitatively and quantitatively comparing b=1000 s/mm2 (b1000) and b=2000s/mm2 (b2000) DWI for the detectability and conspicuity of rectal tumors,
using a 3T state of-the-art MR scanner.
Methods and materials
A total of 33 patients (42 rectal MR scans) were retrieved from the hospital’s PACS system between November 2016 and October 2017 to be potentially included in this retrospective study; informed consent was waived.
Inclusion criteria were: pathology proven solid (non-mucinous) rectal cancer; availability of DWI-MR scan (primary staging and/or restaging after neoadjuvant treatment before surgery) of the rectum including b1000 and b2000 images.(Fig.1 - Inclusion and exclusion criteria)
A state-of-the-art 3.0T scanner (Achieva,
Philips Medical System,
Best,
the Netherlands) was used to perform MR...
Results
Of the 33 patients (42 MR exams),
3 patients (3 MR exams) were excluded due to biopsy proved mucinous tumors and 2 patients (2 MR exams) were excluded due to nondiagnostic image quality (hip replacement).
Moreover,
7 MR exams with missed pathology (surgery performed after neoadjuvant treatment) were excluded.
A total of 24 patients (29 MR scans) met the inclusion criteria and constituted the final study population (57 ± 12 years,
mean age ± SD).
Of the 29 MR scans,
18 (62%) were performed at...
Conclusion
The use of DWI with ultra high b value (b=2000 s/mm2 ) has the potential to improve tumor conspicuity compared to the more commonly used b=1000 s/mm2 in patients with rectal cancer,
especially for readers with limited experience in reading rectal MRI.
Improved conspicuity could be more beneficial in the restaging setting,
where the differentiation between a complete response and small tumor remnant is of major clinical importance in the light of new conservative treatment strategies (i.e.
watchfull waiting).
Further validation in larger patient population,...
Personal information
Department of Radiology and Bioimaging,
"G.
D'Annuzio" University,
Chieti-Pescara,
"Ss.
Annunziata" - Chieti - Chieti/IT
References
1.
Beets-Tan RGH,
Lambregts DMJ,
Maas M,
et al.
Magnetic resonance imaging for clinical management of rectal cancer: Updated recommendations from the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting.
Eur Radiol 2018; 28(4): 1465-75.
2.
Maas M,
Beets-Tan RG,
Lambregts DM,
et al.
Wait-and-see policy for clinical complete responders after chemoradiation for rectal cancer.
J Clin Oncol 2011; 29(35): 4633-40.
3.
van der Paardt MP,
Zagers MB,
Beets-Tan RG,
Stoker J,
Bipat S.
Patients who undergo preoperative chemoradiotherapy for locally advanced...