Low-Dose Radiation to Prevent Complications of Back Surgery

June 6, 2013 updated by: University of Pittsburgh

Radiotherapy to Prevent Fibrosis After Lumbar Laminectomy

More than 10,000 people each year in the United States have "failed back surgery syndrome" caused by scars that form around the outer surface of the spinal cord. Such scarring, known as peridural fibrosis, is common after back surgery known as either lumbar discectomy or laminectomy. Peridural fibrosis may cause recurring low back pain or leg pain after surgery. Operating again to remove the scar tissue often leads to more scarring.

Researchers have not previously studied radiation as a way to prevent peridural fibrosis. We will test whether low-dose radiation given 24 hours before surgery will decrease the amount of peridural fibrosis and if this reduction will lead to improved results of surgery. Half of the participants will receive radiation before surgery and the other half will not. We will evaluate patients at followup visits 1, 3, 6, and 12 months after surgery with a physical exam and questionnaire. At 12 months, we will obtain magnetic resonance imaging (MRI) of the lower spine.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Researchers have long known that low-dose radiation inhibits fibroblast and osteoblast activity. Studies in humans have shown that perioperative radiation therapy is a useful way to prevent both keloid and heterotopic bone formation. However, researchers have not previously studied radiation as a means to inhibit peridural fibrosis. Our previous studies of both rat and dog models showed a significant reduction in peridural fibrosis after laminectomy using low-dose external beam radiation (700 cGy) given 24 hours prior to surgery. Based on our results from these animal studies, we will test whether (1) low-dose radiation given 24 hours before surgery will decrease the amount of peridural fibrosis in people and (2) this reduction in peridural fibrosis will lead to improved results of surgery.

For this study, we will enroll 46 patients with failed back surgery syndrome believed to be secondary to perineural fibrosis in a randomized, double-blinded, controlled clinical trial. We will assign patients to one of two groups before surgery: preoperative radiation (treatment group) or no preoperative radiation (control group). We will treat half of the patients with external beam radiation before re-exploration and decompression of their peridural fibrosis (treatment group) and perform re-exploration and decompression in the other half without preoperative radiation (control group).

All patients will undergo simulation radiation treatment planning and will not know if they received radiation or not. For patients randomized to receive preoperative radiation, we will administer a single dose of 700 cGy to a 6.0-cm-wide field centered on the spinal cord at the affected level, using a 6 MV Varian 600C linear accelerator. We will administer treatment with two fields angled 45 degrees from the vertical plane so that the skin surface for the proposed incision will not be irritated. This should prevent any wound healing problems. Only the radiation oncologist and research assistant will know whether radiation was administered. The patient and the surgeon will be masked as to the treatment.

The neurosurgeon co-investigators will perform the same surgical procedure on all patients 24 hours after their radiation (or sham) treatment. We will give all patients preoperative antibiotics. The surgeon will reopen the previous midline posterior lumbar skin incision and dissect the subcutaneous tissue away from the spinous process and laminae. Once the surgeon has adequately exposed the previous surgical site, he or she will place a self-retaining retractor. The surgeon will decompress the nerve by removing the scar tissue from around the nerve root and thecal sac. The surgeon will also remove any intravertebral disc material thought to be causing nerve root compression. On completion of the operation, the surgeon will stop bleeding with electrocautery, irrigate the wound with antibiotic, and close the wound in layers. In general, the hospital stay after surgery is one night. The patient begins gradual ambulation on the evening of surgery.

We will administer the North American Spine Society (NASS) Lumbar Spine Outcome Assessment to patients before treatment and at followup visits to assess their physical functioning. We will also use the NASS questionnaire to collect demographic and lifestyle information at baseline and to assess patient expectations regarding treatment and level of satisfaction with the treatment during the followup period. We will do a physical examination and administer the patient-reported questionnaire prior to surgery and at 1, 3, 6, and 12 months after surgery. We will obtain magnetic resonance (MR) imaging of the lumbar spine 12 months after treatment.

Study Type

Interventional

Enrollment

46

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15213
        • University of Pittsburgh Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 78 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with a clinical diagnosis of failed back surgery syndrome.
  • Previous surgery at either the L4-5 or L5-S1 levels.
  • Patients with peridural fibrosis around the symptomatic nerve root (either L5 or S1) on contrast-enhanced MR imaging.
  • Willing and able to be treated and followed at the University of Pittsburgh Medical Center.
  • Cooperative individuals with no language barrier, and who sign an informed consent form.

Exclusion Criteria:

  • Patients less than 18 years of age.
  • Patients with prior radiotherapy to the same region of the back.
  • Female patients with a functioning, intact reproductive system are ineligible until a pregnancy test performed within 48 hours of radiotherapy rules out pregnancy.
  • Patients with organic brain syndrome or dementia.
  • Severe vascular, pulmonary or coronary artery disease which would place them at an unacceptably high risk to undergo general anesthesia.
  • Myocardial infarction within the last 6 months.
  • Metastatic cancer.
  • Excessive alcohol consumption or evidence of drug use.
  • Spondylolisthesis requiring surgical fusion (greater than 5 mm of vertebral slippage.)
  • Unable to undergo MR imaging.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Double

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Pittsburgh

Collaborators

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

Investigators

  • Principal Investigator: Peter C. Gerszten, MD, University of Pittsburgh

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2000

Study Completion

October 1, 2002

Study Registration Dates

First Submitted

July 5, 2001

First Submitted That Met QC Criteria

July 6, 2001

First Posted (Estimate)

July 9, 2001

Study Record Updates

Last Update Posted (Estimate)

June 7, 2013

Last Update Submitted That Met QC Criteria

June 6, 2013

Last Verified

March 1, 2006

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R21AR047121 (U.S. NIH Grant/Contract)
  • NIAMS-057

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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