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Testing VisualEditor
=== Hardware ===
'''MRI (first choice)'''
* Mandatory for both primary staging and restaging of rectal cancer.
* Requires an external surface coil
'''Endorectal ultrasound (EUS)'''
* Staging for early tumours considered for local excision
* Superior diagnostic performance for differentiating T1 from T2 tumors
=== Patient preparation ===
* Use of an enema is not routinely recommended
'''Spasmolytics (optional)'''
* may be useful to reduce bowel movement artefacts (no consensus: 57 % recommended/mandatory)
* Can be benefical for upper rectal tumors and when imaging is performed at 3.0T (bowel movement artifacts are most prevalent)
'''Endorectal filling (optional)'''
* Not routinely advised (no consensus: 71 % not recommended)
* '''~60 ml of gel''' (higher volumes compress perirectal tissues significantly)
'''Sequences'''
* A routine protocol should (at least) include:
** 2D T2W sequences in 3 planes
All tumours:
* Transverse sequences: perpedicular to the rectal tumour axis
* Coronal sequences: parallel to the rectal tumour axis
Distal tumours:
* Include coronal sequence parallel to the anal canal to assess the relation between tumour and anal sphincter
Morphology
* Solid - polypoid
* Solid - (semi-)annular
Circunferential location within the rectal wall
* e.g. from X to X o'clock
* Should routinely be reported
==== Distance from anorectal junction ====
* Distance from the anorectal junction to the lower pole of the tumour
Although the panel agreed unanimously that ‘some measure of tumour size’
should be reported, there was no clear consensus on a specific metric, i.e. whether this should be one-dimensional, threedimensional or a volume measurement, and if and how after CRT an estimation of the tumour volume reduction should be provided. There is no solid evidence that favours one over
another, although some authors have suggested that, specifically for assessment of chemoradiotherapeutic response, whole volume measurements may be preferable [23]. The panel acknowledges that several options exist but from a practical point of view decided to include tumour length as the main metric in the structured report template in Fig. 1, as this was deemed to be most commonly used and more practically applicable than other metrics, with good reported measurement reproducibility [20, 23, 24].
==== T-stage ====
* MRI doesn't differentiate T1 from T2
*'''T1-T2: limited to intestinal wall'''
Observations:
* Stranding into mesorectal fat = equivocal sign; may indicate either a T2 or T3 tumour
* Invasion of the pelvic floor or pelvic side wall muscles = T4
Depth of invasion
* invades only the internal sphincter muscle (T3)
* also involves the intersphincteric plane
Height of invasion
* involves only the proximal 1/3 of the complex/anal canal
* also involves the middle 1/3 of the complex/anal canal
Observations:
* The anterior peritoneal reflection is a landmark that is usually recognised easily on MRI and separates the intra- and extra-peritoneal portions of the mesorectal compartment. Above the anterior peritoneal reflection, the mesorectal compartment is no longer enveloped by the mesorectal fascia on its anterior aspect. As such, anterior mesorectal fascia involvement should only be reported when below the level of the anterior peritoneal reflection.
* Mesorectal fascia involvement:
=== Lymph nodes and tumour deposits ===
* Important risk factor for local recurrence
'''Morphologically suspicious characteristics'''
* Round shape
* Irregular border
'''Malignant node criteria'''
* Short axis diameter ≥9 mm
* Short axis diameter 5-8 mm + ≥2 morphologically suspicious characteristics
=== Extramural vascular invasion (EMVI) ===
* Assessment of extramural vascular (or venous) invasion (EMVI) should be reported routinely, both for primary staging as well as for restaging after CRT.
* EMVI is an important prognostic staging factor
== Restaging after neoadjuvant treatment ==
* Structured reporting is recommended
* When considering organ preservation (watchful waiting) after CRT, MRI findings should be correlated with clinical examination (endoscopy / digital rectal examination)
=== Local tumour status ===
T2W
* '''No residual tumour mass'''
** '''Complete response''': a normalised, two-layered rectal wall
*Sphincter invasion
For low tumours with sphincter invasion, describe:
Depth of invasion
* invades only the internal sphincter muscle
* also involves the intersphincteric plane
Height of invasion
* involves only the proximal 1/3 of the complex/anal canal
* also involves the middle 1/3 of the complex/anal canal
=== Mesorectal fascia (and peritoneal) involvement ===
* If a fatpad re-appears between the tumour and MRF after CRT, the MRF should be considered uninvolved/cleared.
* Persistent stranding of tumour into the MRF should be considered an equivocal sign that may or may not indicate persistent MRF involvement
== Downloads ==
* [https://link.springer.com/content/pdf/10.1007%2Fs00330-017-5026-2.pdf] Magnetic resonance imaging for clinical management of rectal cancer: Updated recommendations from the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting
