EP460 - Preoperative MRI Compared To Pathologic Nodal Status In Patients With Rectal Cancer Who Did Not Undergo Neoadjuvant Therapy

Sunday, May 11, 2025

12:57 PM – 1:02 PM PT

Location: Monitor 9, Sails Pavilion, Upper Level

ePoster Presenter(s)

Matthew C. Moccia, MD

Resident
Cooper University Healthcare
Cooper Medical School of Rowan University
Philadelphia, PA, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Author(s)

HS

Hannah Sofield, MD

Resident
Cooper University Healthcare
Camden, New Jersey, United States

Disclosure information not submitted.
DG

Danica N. Giugliano, MD, FACS

Colorectal Surgeon
Cooper University Healthcare
Camden, New Jersey, United States

Disclosure information not submitted.
MK

Michael E. Kwiatt, MD, FACS, FASCRS

Colorectal Surgeon
Cooper University Healthcare
Camden, New Jersey, United States

Disclosure information not submitted.
EI

Elizabeth P. Ives, MD

Head, Division of Body Imaging
Cooper University Healthcare
Camden, New Jersey, United States

Disclosure information not submitted.
RG

Ron Gefen, MD

Interim Chief and Chair, Department of Radiology
Cooper University Healthcare
Camden, New Jersey, United States

Disclosure information not submitted.

Senior Author(s)

SM

Steven J. McClane, MD, FACS, FASCRS

Head, Division of Colorectal Surgery
Cooper University Healthcare
Camden, New Jersey, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

All of the relevant financial relationships listed below have been mitigated.

Matthew C. Moccia, MD: This individual has no financial relationships with ineligible companies.

Steven J. McClane, MD, FACS, FASCRS: This individual has no financial relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: Rectal cancer affects more than 40,000 adults in the United States each year. Magnetic resonance imaging (MRI) is the mainstay for preoperative tumor staging. However, sensitivity and specificity for MRI reported lymph node positivity is < 80%, leading to some debate as to how this value should be considered when determining treatment stratification. Neoadjuvant chemotherapy and/or radiation are usually recommended for patients with lymph node positive disease discovered on preoperative rectal cancer protocol MRI scans.

Methods/Interventions: The internal REDCap rectal cancer database at our single, large-volume, NAPRC-accredited cancer center was queried for patients diagnosed and/or treated at our institution. In these patients, preoperative lymph node positivity was determined by rectal cancer protocol MRI using the SAR Primary Rectal Cancer Staging Template (v.2021), in which positivity is determined by a combination of nodal size, shape, borders and signal intensity.

Results/Outcomes: Over the past four years, 163 patients had rectal cancer surgeries that included total mesorectal excisions (TME) at our institution. Of these patients, 100 had neoadjuvant therapies, leaving 63 patients with pathologic specimens unaffected by neoadjuvant therapies. 46 of the 63 patients had a preoperative, rectal cancer protocol, synoptic MRI scan. 9 of these patients had node positive MRI scans, while 37 patients had node negative MRI scans. Of the 9 patients with node positive MRI scans, only 1 was node positive on final pathology. Of the 37 patients with node negative MRI scans, 28 were node negative on final pathology. In this limited cohort, sensitivity of MRI for detecting node positive disease was 10%, while specificity for nodal positivity was 78%. Positive predictive value (PPV) was only 11%, and negative predictive value (NPV) was 76%.

Conclusion/Discussion: The overall sensitivity and specificity of rectal MRI has been previously validated. However, there is a paucity of recent literature directly comparing nodal disease between MRI synoptic reports and pathologic specimens in patients who have never underwent neoadjuvant treatment. Although a small cohort, our retrospective data supports previous concerns about the validity and usefulness of using MRI synoptic reported preoperative lymph node status when deciding on treatment algorithms for patients newly diagnosed rectal cancer. More investigation is warranted.