Feasibility of Sentinel Lymph Node Biopsy in Rectal Cancer

Oxford University Hospitals NHS Trust15 enrolled

Overview

This study will assess whether the Sienna+/Sentimag system, which involves a magnetic tracer, is effective in identifying the sentinel lymph node in rectal cancer and whether it is then feasible to remove this lymph node during surgery to locally excise early rectal cancer.

One issue in managing rectal cancer is identifying which patients will benefit from less radical surgery, which is much safer and better tolerated. However it does not remove lymph nodes where cancer cells may have spread. If lymph nodes containing cancer are left behind, the cancer may recur. So this surgery is only suitable in early rectal cancers not involving lymph nodes. Unfortunately, current investigations do not always accurately identify involved lymph nodes. Sentinel lymph node biopsy (SLNB) is a technique to surgically remove the first lymph node where cancer cells spread. If this lymph node contains cancer, radical surgery is needed to reduce the risk of recurrence. However if it is clear, less radical surgery should be sufficient. This is standard practice for breast cancer and avoids unnecessary major surgery in many patients. The investigators aim to assess whether SLNB is useful in rectal cancer. The investigators will determine whether the Sienna+/Sentimag system effectively identifies the sentinel lymph node, and whether the node can then be removed surgically. The investigators will recruit patients in Oxford hospitals about to undergo surgery for rectal cancer. Patients will receive an injection of magnetic tracer during endoscopy prior to surgery. Some patients will have an extra MRI scan. During or after surgery, depending on the type of operation planned, a magnetic probe will be used to locate the sentinel lymph node in the tissue around the rectum. The removed specimen will be examined by a pathologist. Funding to undertake this study has been granted by the National Institute for Health Research (NIHR). Endomagnetics, the manufacturer, will supply the magnetic tracer and probe for use in this study. If successful, the investigators will plan a larger clinical trial. This could have a major impact on improving outcomes for patients by allowing less radical surgery to be used where it is most appropriate.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Rectal Cancer

Interventions

Sienna+ injectionDRUG

Endoscopic injection of magnetic tracer

MRI scanOTHER

MRI scan of pelvis to detect spread of magnetic tracer

Surgery to excise rectal cancerPROCEDURE

Surgery as scheduled according to size and stage of rectal cancer. This will be either radical surgery or transanal endoscopic microsurgery (TEM)

Eligibility

Sex: ALLMin age: 18 YearsMax age: 90 Years

Medical Language ↔ Plain English

Inclusion Criteria: * diagnosed with operable rectal cancer * case discussed at Oxford Colorectal Cancer multi-disciplinary team (MDT) meeting * willing and able to give informed consent * willing and able to comply with all trial requirements, in the investigator's opinion Exclusion Criteria: * females who are pregnant or lactating * known intolerance or hypersensitivity to iron, dextran compounds, magnetic tracers or superparamagnetic iron oxide particles (SPIO) * cancer involvement of anal sphincter complex * adults who are not able to give consent or are deemed vulnerable

Locations (1)

Churchill Hospital

Oxford, United Kingdom

Outcomes

Primary Outcomes

Number of Participants Experiencing of Adverse or Hypersensitivity Reaction

Assess frequency of any adverse of hypersensitivity reactions to tracer after endoscopic injection

Time frame: 5 days after injection

Number of Operations Where Effects of Tracer Injection Can be Detected by Surgeon During Surgery

Assess frequency of Sienna+ tracer being detectable at the tumour injection site and in the lymph nodes at the time of surgery

Time frame: at time of surgery

Number of Operations Where There Was Any Surgical Difficulty Due to Tracer Injection Based on Qualitative Assessment by Surgeon

Surgeon's qualitative assessment of any difficulties encountered during surgery which could be attributable to prior injection of the tracer, such as pigmentation or fibrosis making surgery more difficult than normal

Time frame: at time of surgery

Secondary Outcomes

Number of Mesorectal Specimens Which Demonstrated Correlation Between Histopathology and Sentimag Probe Findings for Lymph Node Number and Location

The histopathology findings of lymph node distribution in the excised mesorectal specimen correlated with the information provided by the Sentimag probe.

Time frame: 5 days after surgery

Number of Mesorectal Specimens Which Demonstrated Coincidence Between Histopathological and Sentimag Probe Identification of the 'Sentinel' Lymph Node

A pathologist will identify the sentinel lymph node histologically and record whether this matches the location identified by the Sentimag probe which has been previously marked with a suture

Time frame: 5 days after surgery

High Resolution MRI Composite Map of Drainage Pattern of Sienna+ Tracer in Mesorectum

Data from ClinicalTrials.gov

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