A Superiority Trial of Radiofrequency Ablation for Low Back Pain

NCT07222462 | Recruiting DMC

• 2 other identifiers: Pro00075903U01AR084723
• Study Type: interventional
• Target: 300
• Locations: 1 country
• Sites: 3

Brief Summary

The purpose of the ASTRAL Study is to evaluate the effectiveness of LRFA (Lumbar radiofrequency ablation) against a control procedure. The ASTRAL Study will enroll individuals with chronic low back pain (CLBP) and randomly assign them to one of three groups: lumbar radiofrequency ablation using conventional electrodes placed parallel to the medial branch nerves (LRFA-C), lumbar radiofrequency ablation using multi-tined electrodes placed perpendicular to the medial branch nerves (LRFA-M), or a simulated radiofrequency ablation procedure.

Conditions

Chronic Low Back Pain (CLBP)

Keywords

lumbar radiofrequency ablation (LRFA); corticosteroid injections

Outcome Measures

Primary Outcomes (1)

• Back-related functional limitations

  Measured using the Roland-Morris Disability Questionnaire (RMDQ), a 24-item questionnaire that evaluates patients' self-reported functional limitations due to back pain. The total score ranges from 0 (no disability) to 24 (severe disability).

  3 months post-randomization

Secondary Outcomes (15)

• Back-related functional limitations

  1 month post-randomization

• Back-related functional limitations

  6 months post-randomization

• Back-related functional limitations

  12 months post-randomization

• Procedure duration

  Day of intervention, after procedure

• Radiation dose

  Day of intervention, after procedure

Other Outcomes (80)

• Quality of life (EuroQoL 5-item)

  3 months post-randomization

• Quality of life (EuroQoL 5-item)

  1 month post-randomization

• Quality of life (EuroQoL 5-item)

  6 months post-randomization

Study Arms (3)

LRFA-C

ACTIVE COMPARATOR

Lumbar radiofrequency ablation with conventional electrodes

Procedure: Lumbar radiofrequency ablation with conventional electrodes (LRFA-C)

LRFA-M

ACTIVE COMPARATOR

Lumbar radiofrequency ablation with multi-tined electrodes

Procedure: Lumbar radiofrequency ablation with multi-tined electrodes (LRFA-M)

Simulated LRFA

SHAM COMPARATOR

Simulated lumbar radiofrequency ablation

Procedure: Simulated lumbar radiofrequency ablation

Interventions

Lumbar radiofrequency ablation with multi-tined electrodes (LRFA-M) PROCEDURE

LRFA-M positions a multi-tined thermal radiofrequency electrode at each medial branch nerve to be ablated and administers local anesthetic to the nerve. However, the multi-tined thermal radiofrequency electrode is thought to achieve larger lesions and thus does not require parallel electrode placement; the LRFA-M electrode will be placed perpendicular to the medial branch nerve. All subsequent processes are the same as for LRFA-C. This includes local corticosteroid injection at each ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

LRFA-M

Lumbar radiofrequency ablation with conventional electrodes (LRFA-C) PROCEDURE

LRFA-C positions a conventional thermal radiofrequency electrode at each medial branch nerve to be ablated and administers local anesthetic to the nerve. Parallel placement of the electrode will be achieved. Once the electrode is in correct position and nerve stimulation testing done, a radiofrequency lesion is generated, achieving a temperature 80°C-90°C, lasting 90-120 seconds. If a 16-gauge or larger electrode is used, no second lesion needs to be made. If an 18-gauge electrode is used, the electrode will be repositioned slightly by withdrawing or repositioning parallel to the 1st ablation site, or by rotating the electrode, and a 2nd lesion made. Local corticosteroid injection is then performed at the ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

LRFA-C

Simulated lumbar radiofrequency ablation PROCEDURE

The simulated LRFA control procedure will be performed in an identical fashion to LRFA-M, except 1) after electrode positioning, a neurodestructive lesion will not be made; and 2) a pre-recorded audio recording of the procedure will be played (out of view of the patient, immediately adjacent to the RFA machine) in order to simulate the beeping and other sounds of the machine and to ensure the appropriate length of the simulated procedure. The electrode will remain in place for the 90-120 seconds that lesioning would normally take, but without heat application. The electrode will then be repositioned to simulate a second lesion, also of duration 90-120 seconds. Local corticosteroid injection is then performed at the ablation site at a total corticosteroid equivalent of 80mg triamcinolone, divided equally among the medial branches targeted; this dose can be reduced as needed according to the medical status of each patient. This process is applied for each medial branch nerve targeted.

Simulated LRFA

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years
• CLBP of duration ≥ 3 months. Low back pain is defined as occurring between the lower posterior margin of the rib cage and the horizontal gluteal fold.
• Low back pain intensity numerical rating scale (NRS) ≥ 4 with one of the following prior to LRFA: 1) Current low back pain intensity, 2) Average pain over past 7 days, OR 3) Pain intensity without specification of recall period
• Has had conservative treatments for CLBP (physical therapy, exercise therapy, spinal manipulation, massage, acupuncture, etc.)
• Candidate for unilateral LRFA (L1-S1 joints; ≤3 levels); or bilateral LRFA (L1-S1 joints; ≤2 levels)
• 'Positive responses' (≥80% improvement of CLBP pain intensity) to 2 sets of anesthetic-only MBBs (≤0.5cc of local anesthetic)
• Able to read, speak, and understand English sufficient for informed consent purposes
• Stated willingness to comply with all study processes and availability for the duration of the study, and provision of a signed and dated informed consent form

You may not qualify if:

• CLBP attributed primarily to specific spine-related conditions (radiculopathy, lumbar spinal stenosis, spinal instability), 'red flag' conditions (infection / malignancy / fracture), and/or inflammatory arthritis (RA, SpA, etc.)
• Prior LRFA
• Prior lumbar facet joint (intra-articular or medial branch nerve) corticosteroid injections (past 6 months)
• Surgery involving one or more of spinal levels where LRFA is to be performed, in the past 2 years
• Lumbar fusion involving the spinal levels where LRFA is considered, at any time
• Prior known severe lumbar central canal stenosis on MRI as defined by Lee (2011): obliteration of the cerebrospinal fluid (CSF), and marked compression of dural sac, and none of the cauda equina can be visually separated from each other. No new MRIs would be done specifically as part of the study processes.
• Prior formal diagnosis of fibromyalgia by a rheumatologist (diagnosis by primary care physician or pain medicine specialist is not sufficient)
• Unstable psychiatric or terminal medical conditions that would limit study participation and the likelihood of follow-up for 12 months post-randomization
• Pregnancy, being a prisoner, or having a prior formal diagnosis of cognitive impairment by a neuropsychologist or neurologist, confirmed by health record documentation
• Participant report of prior formal diagnosis of cognitive impairment by a neuropsychologist or neurologist can be obtained, but participant-reported cognitive impairment by a neuropsychologist or neurologist must be confirmed via health record documentation. No new evaluations for cognitive impairment would be done specifically as part of the study processes.
• Contraindication to local anesthetic, corticosteroid, or any aspects of LRFA
• Cannot reach MBB targets with 11.9cm needle
• Major planned life events over the next 4 months that might interfere with study participation (e.g., major abdominal or chest surgery or extended vacation)

Sponsors & Collaborators

• University of Washington: lead
• National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS): collaborator

Study Sites (3)

Emory Musculoskeletal Institute

Atlanta, Georgia, 30329, United States

RECRUITING

Cleveland Clinic

Cleveland, Ohio, 44195, United States

RECRUITING

University of Utah Orthopaedic Center/PM&R

Salt Lake City, Utah, 84108, United States

NOT YET RECRUITING

Related Links

• ASTRAL Study general information website

Study Officials

• Pradeep Suri, MD

  University of Washington

  PRINCIPAL INVESTIGATOR

• Janna Friedly, MD

  University of Washington

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Research Study Coordinator

CONTACT

206-210-4040; astralstudy@uw.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Multiple Principal Investigator

Study Record Dates

• First Submitted: October 27, 2025
• First Posted: October 29, 2025
• Study Start: February 4, 2026
• Primary Completion (Estimated): March 1, 2029
• Study Completion (Estimated): August 1, 2029
• Last Updated: February 9, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: We will share a complete, cleaned, de-identified copy of the locked final dataset used in conducting the final analyses upon which the accepted primary study publication is based. Data will be made available no later than when the first manuscript reporting on 12-month outcomes is published, or end of the performance period, whichever comes first. A complete dataset will be permanently archived and available through Zenodo, a generalist repository providing long-term access to and preservation of data.
• Access Criteria: Registered and approved users of the data must propose specific research questions in an analysis plan and sign a data use agreement (DUA). Documentation will be made available including the study protocol, the final data management and sharing plan, data dictionary/codebook, a statistical analysis plan, data collection instruments, informed consent document, and citations to the main publications based on analyses of data being deposited. For approved requests, data made available via Zenodo will include the de-identified analyzable dataset in CSV format, data variable and value labeling guidelines, and analytic code (including code used to create derived variables).

Locations

US (3)