RTOG 0631 Phase II/III Study of Image-guided Stereotactic Radiosurgery for Localized Spine Metastases: Phase II Results

Abstract

Purpose-The phase II component of RTOG 0631 assessed the feasibility and safety of spine radiosurgery (SRS) for localized spine metastases in a cooperative group setting.Materials and Methods-Patients with 1-3 spine metastasis with a Numerical Rating Pain Scale (NRPS) score ≥ 5 received 16 Gy single fraction SRS. The primary endpoint was SRS feasibility: image-guidance RT (IGRT) targeting accuracy ≤ 2mm, target volume coverage > 90% of prescription dose, maintaining spinal cord dose constraints (10 Gy to ≤ 10% of the cord volume from 5-6mm above to 5-6mm below the target or absolute spinal cord volume < 0.35cc) and other normal tissue dose constraints. A feasibility success rate < 70% was considered unacceptable for continuation of the phase III component. Based on the one-sample exact binomial test with α=0.10 Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. (1-sided), 41 patients were required. Acute toxicity was assessed using the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3.0. NIH Public AccessResults-Sixty-five institutions were credentialed with spine phantom dosimetry and IGRT compliance. Forty-six patients were accrued, and 44 were eligible. There were 4 cervical, 21 thoracic and 19 lumbar sites. Median NRPS was 7 at presentation. Final pre-treatment rapid review was approved in 100%. Accuracy of image-guided SRS targeting was in compliance with the protocol in 95%. The target coverage and spinal cord dose constraint were in accordance with the protocol requirements in 100% and 97%. Overall compliance for other normal tissue constraints was per protocol in 74%. There were no cases of grade 4-5 acute treatment-related toxicity. Conclusion-The phase II results demonstrate the feasibility and accurate use of SRS to treat spinal metastases, with rigorous quality control, in a cooperative group setting. The planned RTOG 0631 phase III component will proceed to compare pain relief and quality of life between SRS and external beam radiotherapy.

Biological 18[F]-FDG-PET image-guided dose painting by numbers for painful uncomplicated bone metastases: A 3-arm randomized phase II trial

“…Stereotactic body radiotherapy (SBRT) for bone metastases tries to improve the pain response by increasing the dose to the bone metastases with promising safety and efficacy as reported in non-randomized studies [5,6,26,28,33]. Pain relief is seen in over 80% of the patients treated with SBRT.…”

The role of stereotactic body radiotherapy and stereotactic radiosurgery in the re-irradiation of metastatic spinal tumors

“…Currently, the most common indication for SBRT re-irradiation is pain, whereas radiologic progression of disease remains a minority indication. Recent cooperative group randomized studies investigating spinal SBRT have established pain control as a primary end point, and have curiously overlooked radiologic control as either a primary or secondary end point, possibly due to variable follow-up imaging in practice [21]. Further complicating matters is the significant risk for vertebral body compression fractures after SRS and SBRT spinal irradiation.…”

Best of International Stereotactic Radiosurgery Society Congress 2013: Stereotactic Body Radiation Therapy. Part I: Spinal Tumors

“…The Radiation Therapy Oncology Group is conducting a Phase II/III trial of stereotactic body radiation therapy (SBRT) for spinal metastasis (RTOG 0631) and preliminary results demonstrating the feasibility and safety of the Phase II component were presented in the plenary session of the International Stereotactic Radiosurgery Society congress by Ryu [1]. Forty-one patients each with one to three spinal metastases were enrolled in the study and each lesion was treated to a dose of 16 Gy in one fraction.…”

“…Grade 1-2 and grade 3-5 SBRTrelated adverse events were observed in seven and zero patients, respectively. Grade 3-4 non-SBRT-related adverse events were observed in four patients [1]. Clinical outcomes with respect to local control (LC) and pain control will follow as data mature, and the Phase III portion of the trial comparing conventional radiotherapy to a dose of 8 Gy in one fraction and SBRT to a dose of 16-18 Gy is ongoing.…”