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Background: Assessment of tumor response in rectal cancer after neoadjuvant treatment by MRI (Tumour Regression Grade, TRG 1-5) is well standardized. The overall timing and method of defining complete response (cCR) remain controversial. The aim of this work was to evaluate the feasibility of a defined Response Surveillance Program (RSP) to increase organ preservation for locally advanced rectal cancer after neoadjuvant treatment., Methods: A standardized program of clinical (CR), radiological (RR) and metabolic (MR) assessment of tumor response is defined over a 6 month period from completion of NACRT with formal assessment performed every 2 months (M). Patients with TRG1-3 at M2 and TRG1-2 at M4 continue in the program up to M6 assessment. Patients managed with this protocol from 2016 to 2020 were analyzed. The primary endpoint was rectal preservation rate. Secondary endpoints included disease-free survival and overall survival at 3 years., Result: 314 potentially suitable patients were enrolled in the RSP and 50 patients completed the six month program and were successfully enrolled into watch and wait. Fourteen (28%) were T2 tumor stage, 27 (54%) T3 and nine (18%) were T4. During watch and wait, patients with locoregional recurrence (n = 11) were treated with local excision (n = 3), endocavitary radiotherapy (n = 1), TME (n = 5) and APR (n = 2). With a median follow-up of 32 months, the rectal preservation rate was 88%, with a 3-year disease-free survival of 67% and an overall survival of 98%., Conclusion: This study validates the feasibility of the practical implementation of a Response Surveillance Program to increase organ preservation rates without compromising oncological outcomes in rectal cancer., (Copyright © 2022 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)