Establishment of MRI Model for pTRG in Rectal Cancer With Establishment of

Study Overview
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Brief Summary
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This study proposeto integrate a variety of imaging quantitative indicators to establish a new MRI-based tumor response regression(mrTRG) classification method. The accuracy of the established mrTRG classification method according pathology TRG(pTRG) will be tested. The ability of the established mrTRG classification method to predict prognosis will also be tested.

Detailed Description
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The study included two part: one is a retrospective single-center cohort for analyzing quantitative MRI factors associated with pTRG, from which a new MRI-based tumor response regression(mrTRG) classification method will be established. The other is a prospective multi-center cohort for testing the accuracy of the established mrTRG classification according to pTRG; and also for validating the established mrTRG classification associated with survival.

Official Title
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Establishment of a Quantified Imaging Method for Evaluating Tumor Response Grade in Rectal Cancer Patient With Neoadjuvant Therapy: a Multi-center Study

Conditions
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Rectal Cancer

Intervention / Treatment
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* Diagnostic Test: pelvic MRI for establishing new mrTRG method


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: biopsy-proved primary rectal cancer baseline MRI confirmed LARC (cT3 and/or cN+) scheduled to take neoadjuvant therapy receive baseline and preoperative pelvic MRI receive TME surgery after NAT have routine follow-up after the operation Exclusion Criteria: history of malignancy or multiple primary cancers receive surgery directly without NAT don't receive TME surgery don't complete NAT simultaneous distant metastasis at the baseline diagnosis lack of baseline or preoperative pelvic MRI incomplete or unavailable pathological information lost to follow-up within three months after surgery (lost since the first follow-up visit)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| rectal cancer with NAT<br>The patients are planned to receive neoadjvant therapy, and then receive radical surgery. | Diagnostic Test: pelvic MRI for establishing new mrTRG method<br>* they will received two pelvic MR examinations before and after neoadjvant therapy. The MRI before neoadjvant therapy is considered as baseline MRI, which is usually taken within 3 weeks before NAT. The MRI after neoadjvant therapy is considered as preoperative MRI, which is usually taken within 3-8 weeks before NAT.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pathological tumor regression grade(pTRG) | pTRG is evaluated according to the AJCC system. pTRG0-1 is defined as good response, pTRG2 as moderate response, and pTRG3 as poor response. The pTRG is judged by two experienced pathologists working together. If there are any discrepancies, then a third senior pathologist is consulted for arbitration. there were any discrepancies, then a third senior pathologist was consulted. there were any discrepancies, then a third senior pathologist was consulted. | within 2 weeks after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| distant metastasis | Distant metastastic lesion detected by follow-up CT which will be performed every 3 month for the first two year and every 6 month since the third year | 3 years from the data of surgery | 
| Death | all cause death | 3 years from the data of surgery | 
| local recurrence |  | 3 years from the data of surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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rectal cancer, neoadjuvant therapy