Feasibility of Sentinel Lymph Node Biopsy in Rectal Cancer

Not Applicable

Terminated

Conditions: Rectal Cancer

Interventions: Drug: Sienna+ injection
Other: MRI scan
Procedure: Surgery to excise rectal cancer
Device: Sentimag probe

Registration Number: NCT02445456

Lead Sponsor: Oxford University Hospitals NHS Trust

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 15

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Ex-vivo	Sienna+ injection	Patients with relatively advanced rectal cancer who are scheduled to undergo radical surgery to excise rectal tumour and mesorectum. They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery. They will then undergo surgery to excise rectal cancer. The excised specimen will be examined using the Sentimag probe and by standard histology to assess for lymph nodes ex-vivo.
In-vivo	Sentimag probe	Patients with early rectal cancer scheduled to undergo local excision of a rectal tumour by transanal endoscopic microsurgery (TEM). They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery, and have an MRI scan to assess tracer spread. They will then undergo TEM surgery to excise the rectal cancer. During surgery the Sentimag probe will be used to locate the sentinel lymph node so it can be surgically removed. The excised specimen will be examined by standard histology.
In-vivo	MRI scan	Patients with early rectal cancer scheduled to undergo local excision of a rectal tumour by transanal endoscopic microsurgery (TEM). They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery, and have an MRI scan to assess tracer spread. They will then undergo TEM surgery to excise the rectal cancer. During surgery the Sentimag probe will be used to locate the sentinel lymph node so it can be surgically removed. The excised specimen will be examined by standard histology.
In-vivo	Surgery to excise rectal cancer	Patients with early rectal cancer scheduled to undergo local excision of a rectal tumour by transanal endoscopic microsurgery (TEM). They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery, and have an MRI scan to assess tracer spread. They will then undergo TEM surgery to excise the rectal cancer. During surgery the Sentimag probe will be used to locate the sentinel lymph node so it can be surgically removed. The excised specimen will be examined by standard histology.
Ex-vivo	Surgery to excise rectal cancer	Patients with relatively advanced rectal cancer who are scheduled to undergo radical surgery to excise rectal tumour and mesorectum. They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery. They will then undergo surgery to excise rectal cancer. The excised specimen will be examined using the Sentimag probe and by standard histology to assess for lymph nodes ex-vivo.
Ex-vivo	Sentimag probe	Patients with relatively advanced rectal cancer who are scheduled to undergo radical surgery to excise rectal tumour and mesorectum. They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery. They will then undergo surgery to excise rectal cancer. The excised specimen will be examined using the Sentimag probe and by standard histology to assess for lymph nodes ex-vivo.
In-vivo	Sienna+ injection	Patients with early rectal cancer scheduled to undergo local excision of a rectal tumour by transanal endoscopic microsurgery (TEM). They will receive endoscopic Sienna+ injection (magnetic tracer) 5 days before planned surgery, and have an MRI scan to assess tracer spread. They will then undergo TEM surgery to excise the rectal cancer. During surgery the Sentimag probe will be used to locate the sentinel lymph node so it can be surgically removed. The excised specimen will be examined by standard histology.

Primary Outcome Measures

Name	Time	Method
Number of Operations Where There Was Any Surgical Difficulty Due to Tracer Injection Based on Qualitative Assessment by Surgeon	at time of surgery	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
Number of Participants Experiencing of Adverse or Hypersensitivity Reaction	5 days after injection	Assess frequency of any adverse of hypersensitivity reactions to tracer after endoscopic injection
Number of Operations Where Effects of Tracer Injection Can be Detected by Surgeon During Surgery	at time of surgery	Assess frequency of Sienna+ tracer being detectable at the tumour injection site and in the lymph nodes at the time of surgery

Secondary Outcome Measures

Name	Time	Method
Number of Mesorectal Specimens Which Demonstrated Correlation Between Histopathology and Sentimag Probe Findings for Lymph Node Number and Location	5 days after surgery	The histopathology findings of lymph node distribution in the excised mesorectal specimen correlated with the information provided by the Sentimag probe.
Number of TEM Operations Where the Sentinel Lymph Node Can be Identified and Removed	at time of surgery	Sentimag probe is used to localise the sentinel node during TEM (transanal endoscopic microsurgery) and then remove it if possible
Number of Mesorectal Specimens Which Demonstrated Coincidence Between Histopathological and Sentimag Probe Identification of the 'Sentinel' Lymph Node	5 days after surgery	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
High Resolution MRI Composite Map of Drainage Pattern of Sienna+ Tracer in Mesorectum	MRI scan done 2 hours after Sienna+ tracer injection	Evaluation of individual variability in Sienna+ distribution after endoscopic injection on high resolution MRI scans to establish a baseline for individual variation