MRI TN Staging should be used with caution when determining the need for preoperative radiotherapy in rectal cancer A Scala, CFM Evans, HS Tilney, DP Edwards, AM Gudgeon Frimley Park Hospital NHS Foundation trust NHS
MRI TN Staging should be used with caution
when determining the need for preoperative
radiotherapy in rectal cancer
A Scala, CFM Evans, HS Tilney, DP Edwards, AM Gudgeon
Frimley Park Hospital NHS Foundation trust
NHS
Total Mesorectal Excision (TME)
Local Recurrence 3%
Disease free survival 80%
Heald RJ, Moran BJ, Ryall RD, MacFarlaine JK. Rectal cancer: the Basingstoke
experience of total mesorectal excision, 1978-1997. Arch Surg.1998
Aug;133(8):894-9
Pre-operative Radiotherapy
↓ local recurrence (4.4% - 9%) 1,2
No clear advantage on overall survival 1
1. Preoperative radiotherapy versus selective postoperative chemoradiotherapy in patients with rectal cancer
(MRC CR07 and NCIC-CTG C016): a multicentre, randomised trial. Lancet. Mar 7, 2009; 373(9666): 811–820.
2. The Swedish Rectal Cancer Trial: Long lasting benefits from radiotherapy on survival and local recurrence rate.
J Clin Oncol 2006: 23: 5644-50
Short Course Radiotherapy (SCRT)
Long course Chemo-radiotherapy (CRT)
↑ pelvic + perineal post surgical infection
↑ chronic bowel dysfunction
↑ urinary and sexual dysfunction (♂ + ♀)
↑ permanent sterility
↑ risk second malignancy
Marijnen CA, van de Velde CJ, Putter H, van den Brink M, Maas CP, Martijn H et al. Impact of short-term pre-operative radiotherapy on health-related
quality of life and sexual functioning in primary rectal cancer: report of a multicenter randomized trial. J Clin Oncol 2005 Mar 20;23:1847-58.
Birgisson H, Pahlman L, Glimeus B. Adverse effects of preoperative radiation therapy for rectal cancer: long term follow up of the Swedish Rectal
Cancer Trial. J Clin Oncol 2006; 23 8697 – 705
Birgisson H, Pahlman L, Gunnarsson U, Glimeus B. Occurrence of second cancers in patients treated with radiotherapy for rectal cancer J Clin Oncol
2005; 23 6126-31
SCRT / CRT toxicity
Guidelines for the management of colorectal cancer 3rd Edition
ACPGBI Guidelines
USA Guidelines
Preoperative staging
1. Mercury Study Group. Diagnostic accuracy of pre-operative magnetic resonance imaging in predicting curative
resection of rectal cancer: prospective observational study. BMJ 2006; 333(7572):779.
2. Bipat S. et al. Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and
MR imaging--a meta-analysis. Radiology. 2004 Sep;232(3):773-83
MRI predicted CRM status accuracy 96.7% 1
MRI LN involvement sensitivity / specificity: 55% / 76% 2
Assess accuracy of pre-operative loco-regional MRI
staging in rectal cancer in a single institution.
• Primary outcomes
- Concordance between MRI and pathological TN Staging
• Secondary outcomes
- CRM status
- Local recurrence
- Cancer survival
- Overall survival
Aim
Data base 1998 – 2013
All rectal cancer resections with pre-operative MRI without neo-adjuvant
SCRT or CRT
Comparison of MRI TN stage with pTN stage
- Neoadjuvant CRT if threatened CRM margins
- Three dedicated colorectal radiologists (Mercury Study)
- Surgery by colorectal specialists
Methods
MRI protocol
Royal Marsden Hospital MRI Rectal Cancer Staging protocol *
Pathology technique
Royal College of Pathology Guidelines
“Dataset for Colorectal Cancer” 2nd Edition 2007
TNM Stage 5th Edition
International Union Against Cancer (UICC)
Methods
* Brown G et al. Techniques and trouble-shooting in high spatial resolution thin slice MRI for rectal cancer. The British Journal
of Radiology. 2005 Mar;78(927):245-51.
Tumour site
Upper
Mid
Lower
87.0%
7.0%
Operation
Anterior resection
APER
Hartmanns
Panproctocolectomy
Results 289 Patients
Results 289 Patients
MRI Stage = p Stage
T 186 (64.3%)
N 166 (57.4%)
TN 119 (41.2%)
Results MRI T Stage
9 (90%)
51 (50%)
120 (74.7%)
6 (40%)
1 (10%)
31 (30.4%)
13 (8.2%)
20 (19.6%) 29 (17.9%)
9 (60%)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
T1 T2 T3 T4
Equal pStage Under-staged Over-staged
Results MRI N Stage
118 (71.1%)
30 (35.7%) 18 (43.9%)
38 (28.9%)
15 (17.9%)
39 (46.4%) 23 (56.1%)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
N0 N1 N2
Equal pStage Under-staged Over-staged
Results MRI N1/N2
125 patients
pN1/2, 70 56%
pN0, 55 44%
44% False Positive
Results CRM status
R0 resection 286 (99.0%)
CRM Involvement 3 (1.0%)
MRI pStage
T2N1 T4N1
T3N0 T4N1
T3N2 T3N2
Follow up 49 months ( 0 - 164)
Adjuvant chemotherapy 108 (37.4%)
Local recurrence 10 (3.5%)
Distant recurrence 46 (15.9%)
5yr overall survival 80%
5yr cancer survival 87.9%
Results Follow up
Results Follow up
MRI T3/4 N2 37 (12.8%)
2 Local Recurrence (5.4%)
• MRI TN stage should be used with caution when assessing
the need for pre-operative radiotherapy
• MRI CRM status correlates consistently with pathological
findings
• Preoperative CRT can be safely reserved for patients with
threatened CRM on MRI
• Good results can be achieved without using SCRT
Conclusions