eP185 - The Predictive Value of Post-treatment MRI in Rectal Cancer Patients Undergoing Total Neoadjuvant Therapy (TNT)

Sunday, June 2, 2024

8:30 AM – 8:35 AM ET, USA

Location: Baltimore Convention Center, Room 318-320

ePoster Presenter(s)

Yaniv Zager, MD

Fellow
Adventhealth
Althamone Springs, FL, United States

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This individual has no financial relationships with ineligible companies.

Author(s)

KS

Katherine Specht, DO, MS

Colorectal Surgery Fellow
AdventHealth
Orlando, FL, United States

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SK

Saed Khalilieh, MD

Resident - General surgery
Department of General Surgery and Transplantations, Sheba Medical Center, Tel Hashomer, Israel.
Department of General Surgery and Transplantations, Sheba Medical Center, Tel Hashomer, Israel.
Tel aviv, HaMerkaz, Israel

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This individual has no financial relationships with ineligible companies.
David M. Habib, MD

Research Fellow
Adventhealth
AdventHealth
Orlando, FL, United States

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Andrew-Paul Deeb, MD, MSc

Colon & Rectal Surgery Fellow
AdventHealth Colorectal Surgery
Orlando, FL, United States

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Ashley Althoff, DO

Colorectal Surgery Fellow
AdventHealth
orlando, FL, United States

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LB

Lindsey Bridges, DO

Colorectal Surgery Fellow
Advent Health
AdventHealth
Orlando, FL, United States

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Senior Author(s)

John RT Monson, MD

Professor of Surgery
Northwell Health
Northwell Health
Ridgefield, CT, United States

Disclosure information not submitted.

Purpose/Background: Rectal Cancer is the fourth most common cancer in the US. There was a significant progression in treatment modalities of rectal cancer during the last few decades including: Neoadjuvant Chemoradiation (CRT), organ preservation, watch and wait and lately Total Neoadjuvant Treatment (TNT). TNT is currently used in cases of locally advanced disease or metastatic disease. Most of patient undergo pelvic Magnetic Resonance Imaging (MRI) study upon diagnosis and then after completion of preoperative treatment – restaging MRI. There is a low volume of published evidence regarding predictive value of MRI after TNT. The aim of this study is to assess the accuracy of post-TNT MRI in predicting actual pathologic staging.Methods/Interventions: We conducted a single center retrospective study. We collected data including demographics, disease staging and treatment, MRI reports. Data were presented using medians and percentages.Results/Outcomes: Between January 2022 – May 2023, twenty-six rectal cancer patients underwent low anterior resection after receiving TNT. Of them, 23 had a post-treatment MRI. Median age was 57.26 (37.22 – 72.94) years. Twelve (52.17%) of them were Female. Twenty-one patients (91.3%) received TNT due to locally advanced disease and two patients (8.7%) were treated with TNT due to metastatic disease. The median time between completion of treatment and restaging MRI was 75 (40-112) days. We had no cases of complete pathological response(pCR). T re-staging by MRI was accurate in 8 (34.78%) cases. N re-staging by MRI was accurate in 11 (47.83%) cases. In 12 (52.17%) cases there was an overestimation of T by restaging MRI, whereas in 3 (13.04%) cases there was underestimation of T by restaging MRI. In 7 (30.43%) cases there was an overestimation of N stage by restaging MRI, whereas in 4 (17.39%) cases there was underestimation of N stage in restaging MRI. In Two cases (8.7%) re-staging MRI demonstrated scar whereas final pathology revealed residual tumor.Conclusion/

Discussion: Re-staging MRI has predictive value in rectal cancer patients undergoing TNT. Further research should be done in order to enhance its accuracy.