The Role Of The Post-CRT MRI In Assessing Response

Transcription

1 Low Rectal Cancer: Is It Safe To Change The Plane Of Surgery? The Role Of The Post-CRT MRI In Assessing Response Nick Battersby, Mit Dattani, Nick West, Graham Branagan, Mark Gudgeon, Phil Quirke, Paris Tekkis, Brendan Moran, Gina Brown The Mercury II Study Group Basingstoke Colorectal

2 Recruiting sites Sites contributed to presented data Sites joined after Radiologists 48 Surgeons 26 Pathologists

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4 Current Practice in Low Rectal Cancer Regardless of the response to CRT the baseline MRI guides the operative decision - ELAPE or intersphincteric resection?

5 Current Practice in Low Rectal Cancer Consensus statement on the multidisciplinary management of patients with recurrent and primary rectal cancer beyond total mesorectal excision planes The Beyond TME Collaborative British Journal of Surgery 2013; 100: E1 E33 Restaging following neoadjuvant therapy None of the available imaging modalities (ERUS, MRI, CT) can reliably predict complete pathological remission, which occurs at a rate of up to 15 per cent for primary clinical (c) T3/T4 cancers. It is not yet clear whether surgical planning is best based around the initial MRI or the scan carried out after neoadjuvant treatment, and further research is needed to assess the reliability of this latter scan.

6 Overall 8.9% pcrm <2% in safe mrlrp + no adverse features pcrm 24% ymrlrp unsafe Battersby et al, Annals of Surgery, 2016

7 MRI reliable for assessing low rectal plane (mrlrp) + ymrlrp Battersby et al, Annals of Surgery, 2016

8 Low Rectal Cancers ( 6cm from AV) Curative resections Median T3a,N0 Battersby et al, Annals of Surgery, 2016

9 Aims Quantify the proportion of patients with a radiological response leading to change in plane Establish whether radiological change in plane alters surgical management Prognostic implications of radiological response

10 Study Profile Low Rectal Cancer (n=326) Baseline MRI Excluded (n= 38) Dropouts (n=9) Deferral of Surgery (n=5) Palliative (no operation) (n=4) Chemoradiotherapy N = 170 Primary Surgery (n=109) No Post-Treatment MRI 9.4% (16/170)

11 Study Profile Low Rectal Cancer (n=326) Baseline MRI Excluded (n= 38) Dropouts (n=9) Deferral of Surgery (n=5) Palliative (no operation) (n=4) Chemoradiotherapy N = 170 Primary Surgery (n=109) No Post-Treatment MRI 9.4% (16/170) SAFE MRI Low Rectal Plane (mrlrp) + Adverse MRI features (n=66/170) Post-treatment MRI UNSAFE MRI Low Rectal Plane (mrlrp) +/- Adverse MRI features (n=92/170) Post-treatment MRI 1. ymrlrp safe AF 30/ ymrlrp safe + AF 27/ ymrlrp unsafe 9/ ymrlrp safe AF 33/ ymrlrp unsafe +/- AF 59/170

12 Baseline 6 weeks post CRT

13 Baseline 6 weeks post CRT

14 Change in Surgical Approach 33 Patients 8 patients 1 Local Excision Distant Metastasis (21 months) 1 Intersphincteric Resection 6 Low Anterior Resection 1 anastomotic leak, 1 late cardiac death (26 months) Also, 5 patients excluded due to ccr 1 Distant metastasis reported in March 2016 (34 months)

15 Assessment of Response By MRI adverse features + change in (y)mrlrp Regression - 43% (66/154) No Change - 51% (79/154) Progression - 6% (9/154) No post-crt MRI - 16

16 DFS: Assessment of Response By MRI adverse features + change in (y)mrlrp Regression - 43% (66/154) No Change - 51% (79/154) No post-crt MRI (16) Progression - 6% (9/154)

17 DFS: Assessment of Response By MRI adverse features + change in (y)mrlrp Regression - 43% (66/154) No Change - 51% (79/154) Progression - 6% (9/154)

18 mrtrg grade -prognosis by DFS Magnetic Resonance Imaging Detected Tumor Response for Locally Advanced Rectal Cancer Predicts Survival Outcomes: MERCURY Experience J Clin Oncol 29: Disease-Free Survival (proportion) ypt Favorable (n = 41) Unfavorable (n = 70) DFS 84% DFS 38% mrtrg Favorable (n = 32) Unfavorable (n = 34) DFS 64% DFS 31% P =.001 P = Time (months) PATHOLOGY - ypt vs DFS Time (months) MRI - mrtrg vs DFS

19 mrtrg I= Complete fibrosis ( pcr) Pretreatment. Post treatment. Intermediate signal tumour between the 11-5 o clock position (arrow). Post treatment image shows a fibrotic low signal scar (arrowhead), no tumour signal.

20 mrtrg 5= no change from baseline Pretreatment. Post treatment. Uday Patel J Clin Oncol 29:

21 DFS: mrtrg1&2 vs mrtrg3-5 GOOD RESPONSE mrtrg 1& (95% CI ) POOR mrtrg RESPONSE (95% CI ) Remaining Cases mrtrg I&II mrtrgiii&v Log Rank (Mantel-Cox) p=0.002

22 Conclusion Insufficient data to comment on changing the operative plane. Continue to plan surgery according to the baseline MRI Prospective evidence of the prognostic value of mrtrg Warn patients of the potential for a complete response consider non-operative management in a trial setting with robust follow up Alternative treatment strategies for poor prognostic group TRIGGER

23 TRIGGER Contact:

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