Intraoperative Electron Radiotherapy in Rectal Cancer - A Feasibility Trial (ELECTRA)

Single centre double-blinded three-arm randomised controlled trial of extended margin surgery + IOERT at standard dose (10 Gy) versus extended margin surgery + IOERT at higher dose (15 Gy) versus extended margin surgery alone in a 1:1:1 ratio in patients with Locally Advanced Rectal Cancer (LARC) or Locally Recurrent Rectal Cancer (LRRC).

Study Overview

• Status: Active, not recruiting
• Conditions: Locally Advanced Rectal Cancer; Locally Recurrent Rectal Cancer
• Intervention / Treatment: Procedure: Extended Margin Surgery; Radiation: Intraoperative Electron Radiotherapy (IOERT)

Detailed Description

Rectal cancer is a cancer that occurs in the pelvis from the rectum. Locally advanced rectal cancer outgrows the rectum and attaches to other body parts in the pelvis and locally recurrent rectal cancer is a rectal cancer that comes back after surgery, and usually attaches to many different pelvic structures. They are both difficult to manage. The standard of care treatment involves chemotherapy and radiotherapy, followed by what is known as an extended margin operation to remove all cancer affected organs and not leave any cancer cells behind. If cancer cells reach the edge of the removed tissue, there is a high chance of leaving cancer cells behind. This is a key predictor of negative outcome in patients. Intraoperative electron beam radiotherapy (IOERT) was developed to help improve patient outcomes. Once the cancer has been removed, the surgeon and a cancer radiotherapy specialist examine the patient's scans, the cancer specimen and the area the cancer was in, and if there is concern about small numbers of cancer cells being left behind they treat the area with radiotherapy to destroy these cells. Patients that are due to receive treatment for these subsets of rectal cancer will be approached to take part. If eligible on the day of surgery the patient will be randomised to one of three arms: Arm A - standard of care (No IOERT), Arm B - extended margin surgery plus IOERT (10 Gy), or Arm C - extended margin surgery plus higher dose IOERT (15 Gy). The surgeon, cancer specialist team and patient will be blinded to study treatment. Patients will be followed up at 30 days, 3 months and for a minimum of 12 months post surgery as part of the trial and they will be followed up for 5 years as part of standard care.

• Study Type: Interventional
• Enrollment (Actual): 31
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Hampshire
    • Southampton, Hampshire, United Kingdom, SO16 6YD
      • University Hospital Southampton NHS Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 16
• Non-metastatic/oligo-metastatic (up to 3 lesions from 2 sites predicted to be radically treatable) - locally advanced or locally recurrent disease involving the posterior or lateral components of the pelvis and predicted to be resectable but with close margins from imaging as determined by a specialist MDT (sMDT)
• Colorectal sMDT review with experience in pelvic exenteration, which has proposed IntrOperative Electron Radiotherapy (IOERT) as an option for treatment
• Patient suitable for IOERT as component of treatment in the view of the responsible Clinical Oncologist
• Performance status ≤1 as defined by the Eastern Cooperative Oncology Group (ECOG)
• Deemed medically fit for surgery
• Written informed consent

Exclusion Criteria:

• Unresectable disease/likelihood of R2 resection
• sMDT determined excess prior radiotherapy within IOERT target zone
• Women who are pregnant or breastfeeding
• Participation within an interventional clinical trial within 3 months of the point of registration within ELECTRA

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: No IOERT; Extended margin surgery	Procedure: Extended Margin Surgery; Surgery intended to remove both a tumour and any metastases
Experimental: Low Dose IOERT; Extended margin surgery and IOERT at standard dose (10 Gy)	Procedure: Extended Margin Surgery; Surgery intended to remove both a tumour and any metastases; Radiation: Intraoperative Electron Radiotherapy (IOERT); IOERT can be defined as the direct application of high-energy electron beam irradiation to a tumour bed during an operative procedure. This approach permits precise delivery of a single large fraction of radiation directly and specifically to high recurrence risk anatomical target areas, which the treating clinicians (surgeon and attending clinical oncologist) predict will be a close or involved margin, while simultaneously displacing and shielding dose-limiting radiosensitive structures such as the small bowel or ureter or any anastomoses, if not involved by tumour.
Experimental: High Dose IOERT; Extended margin surgery and IOERT at higher dose (15 Gy)	Procedure: Extended Margin Surgery; Surgery intended to remove both a tumour and any metastases; Radiation: Intraoperative Electron Radiotherapy (IOERT); IOERT can be defined as the direct application of high-energy electron beam irradiation to a tumour bed during an operative procedure. This approach permits precise delivery of a single large fraction of radiation directly and specifically to high recurrence risk anatomical target areas, which the treating clinicians (surgeon and attending clinical oncologist) predict will be a close or involved margin, while simultaneously displacing and shielding dose-limiting radiosensitive structures such as the small bowel or ureter or any anastomoses, if not involved by tumour.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patients meeting eligibility criteria	Number and percentage of patients meeting eligibility criteria and number of patients referred to a sMDT over the trial period	2 years
Patients accepting randomisation	Number and percentage of patients accepting randomisation	2 years
Successful delivery of IOERT	Number and percentage of patients for which IOERT was successfully delivered as planned as part of the trial	2 years
Blind maintained for patients and clinicians	Number and percentage of patients and clinicians for which blinding was maintained for IOERT delivery	2 years
Questionnaire analysis	Percentage of patients whose questionnaires can be analysed	2 years
Availability of potential primary outcome data	Percentage of patients for whom we can collect information on potential primary outcomes	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Morbidity	Clavien Dindo classification	Up to 30 days post randomisation
Mortality	Mortality	30 days post randomisation
IOERT Field Recurrence	IOERT Field Recurrence is defined as the area directly within the IOERT field as marked by ligaclips or identified by the surgical oncologist for future radiological surveillance.	12 months post randomisation
Overall local recurrence	Overall local recurrence (OLR) is defined as including both IOERT-field and non-IOERT field loco-regional recurrences.	12 months post randomisation
Overall survival	Overall survival	12 months post randomisation
Treatment related toxicity	Treatment related toxicity graded by CTCAE v5	12 months post randomisation
Time to local or systemic recurrence	Time to local or systemic recurrence	Time from randomisation to local or systemic recurrence or 3 years post the start of recruitment, whichever comes first
R1 Rate	R1 Rate	At randomisation
EQ-5D-5L	Quality of life scored from EQ-5D-5L	At 3 and 12 months post randomisation
LRRC QoL	Quality of life scored from LRRC QoL	At 3 and 12 months post randomisation
QLQ-C30	Quality of life scored from QLQ-C30	At 3 and 12 months post randomisation
SF-36	Quality of life scored from SF-36	At 3 and 12 months post randomisation
Resource use and cost	Cost will be estimated for the NHS. An NHS and social care perspective will be used, including intervention costs, outpatient visits and investigations, A&E attendances, hospital admissions, number and dose of each radiotherapy treatment. Itemised resource usage date will be priced using appropriate national sources: Personal Social Services Research Unit (PSSRU), NHS Reference costs and BNF (British National Formulary) for the UK.	At 3 and 12 months post randomisation

Collaborators and Investigators

• Sponsor: University Hospital Southampton NHS Foundation Trust
• Collaborators: Cancer Research UK; IntraOp Medical Corporation; PLANETS Cancer Charity
• Investigators: Principal Investigator: Alex Mirnezami, Prof, University Hospital Southampton NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start (Actual): May 18, 2022
• Primary Completion (Actual): April 25, 2024
• Study Completion (Estimated): April 25, 2027

Study Registration Dates

• First Submitted: March 29, 2023
• First Submitted That Met QC Criteria: May 24, 2023
• First Posted (Actual): May 26, 2023

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Intestinal Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colorectal Neoplasms; Intestinal Neoplasms; Rectal Diseases; Rectal Neoplasms
• Other Study ID Numbers: RHMCAN1600; ISRCTN48105173 (Registry Identifier: ISRCTN)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No