Clinical Data

Clinical Studies
DFINE is committed to building scientific evidence to support the use of our products. The STARTM Tumor Ablation System, received FDA 510(k) clearance in 2010, and is now involved in a multicenter clinical trial in the European Union titled: A Prospective, Non-randomized, Multicenter Clinical Trial to Evaluate the STAR™ Tumor Ablation System and Radiofrequency Kyphoplasty to Treat Painful Metastatic Vertebral Body Tumor(s) in the Spine.

The EU-STAR Ablation Trial is the first prospective study to focus on the substantial palliative benefits of targeted tumor ablation in the interventional oncology arena involving the spine.

Moving forward the company continues to invest in clinical studies to further improve the quality of life for patients suffering from spinal diseases through innovative, minimally invasive therapies.

Published Results
Published clinical data show that rapid and meaningful pain relief from metastatic spinal tumors is a reality for patients who receive t-RFA using the STAR System.  Presented abstracts include the following:

Targeted Radiofrequency Ablation (T-RFA) with Vertebral Augmentation for the Treatment of Symptomatic Metastatic Spinal Tumors: Safety and Efficacy of a Novel Single Treatment System

S. Dhand, J.A. Tepper, S.J. Smith, R.K. Ryu; Northwestern University, Chicago, IL, United States

• 10 patients & 12 lesions treated
• All patients failed conventional chemotherapy and radiation therapy
• All patients reported significant pain relief
• No complications

Treatment of spinal tumors is commonly a multidisciplinary approach, often with several separate therapies to treat the patient’s pain.  We aim to evaluate the safety and efficacy of targeted radiofrequency ablation (t-RFA) combined with vertebral augmentation in patients with symptomatic spinal tumors.

Patients with symptomatic vertebral body metastatic tumors who failed conventional chemotherapy and radiation therapy were prospectively enrolled in this study.  All patients underwent fluoroscopically guided vertebral tumor ablation using a single coaxial system (DFINE, San Jose, CA) to deliver a cooled curved ablation probe into the tumor substance, which was heated by RF energy with overlapping ablation zones.  Injection of ultra-high viscosity bone cement was then performed into the ablated tumor bed.  Pain relief was evaluated with the use of the visual analogue scale (VAS score), obtained before and after the procedure.  T-test was used for statistical analysis with the null hypothesis rejected at p<0.05.

A total of 12 lesions were treated in ten patients.  The procedures were all technically successful in all levels treated (12/12, 100%).  All patients reported a significant decrease in pain shortly after treatment: the mean VAS score before treatment was 8.8 (range (5-10) compared to 2.6 (range 0-6) at a mean of 3.8 days after treatment (range 0-10 days, P<0.01).  No treatment-related complications occurred during the follow up period.

Combined targeted RFA and vertebral augmentation using a single delivery system was safe and effective for the management of painful vertebral tumors. The procedure significantly reduced associated pain that was otherwise not responsive to traditional treatment methods. (emphasis added)

Dhand, et al., JVIR 2013.24(7): p. 1077-78.

Image-guided targeted radiofrequency ablation (t-RFA) of spinal tumors using a novel bipolar navigational device: multicenter initial clinical experience
J. Jennings, W. Irving, B. Georgy, D. Coldwell, B. Zablow, C. DePena, A. Brook

• 73 patients & 101 lesions treated
• T2-S2, Ilium
• No complications
• All patients reported pain relief

Report initial clinical experience and determine the efficacy and safety of targeted radiofrequency ablation (t-RFA) of malignant spinal lesions using a novel bipolar RF ablation system. Demonstrate the use of temperature monitoring of thermocouples (TC) on an articulating electrode to determine ablation size and morphology with use of post-ablation magnetic resonance imaging (MRI) and comparison with pre-clinical thermal distribution curves.

Materials & Methods
101 spinal lesions in 73 procedures were treated at six centers. The STAR Tumor Ablation System includes a robust articulating, navigational bipolar electrode containing two active TCs positioned to permit real time monitoring of the peripheral edge of the ablation zone to determine size of ablation. Treatment was controlled by adjusting power while monitoring TC temperature in-situ. Access and number of ablations were based on lesion size, location and ability to articulate the bipolar electrode. Cement augmentation via the same guiding cannula was performed when required. In some cases, post-procedural MRI was performed. Pain was assessed pre- and post-procedurally.

Lesion etiology included a wide variety of metastatic lesions from T2 to S2 and ilium. No complications or thermal injury occurred. Cement augmentation following t-RFA was efficient and resulted in predictable cement filling. Postablation MRIs demonstrated discrete ablation zones with 3:2 length-to-width aspect ratio consistent in size with thermal monitoring by TCs during the ablation. All patients reported pain relief. (emphasis added)

The STAR device was safely and effectively used in the navigation and t-RFA of spinal malignant lesions. Postablation MRIs confirmed lesions were included in the ablation zone with necrosis of the lesion. The ablation zone was consistent in size with that measured by the TCs and similar in morphology to that extrapolated from thermal distribution curves. The STAR navigational ability allowed for easy access to posterior vertebral body lesions, previously difficult to access with other ablation devices. In many cases, this technique allowed for treatment of individual lesions not controlled by systemic or radiation therapy.

Jennings, et al., JVIR 2013.24(4): p. S44-S45.

Targeted radiofrequency ablation (t-RFA) of metastatic posterior vertebral body lesions in patients with soft tissue sarcomas

J. Ley, J. Jennings, J. Baker, T. Hillen, B. Van Tine; Washington University School of Medicine in St. Louis, St. Louis, MO, United States

• Five patients with metastatic sarcoma with continued progression of lesion following radiation therapy
• Post ablation lesion necrosis with no interruption of primary systemic therapy
• All patients reported pain relief
• No evidence of malignancy or tumor re-growth through 10 months post procedure

Metastatic spinal lesions can be debilitating with significant impact on patients quality of life. Concern for damage to adjacent neural elements during treatment exist due to high radiation doses required to treat certain radioresistant spinal lesions such as soft tissue sarcoma. Radiofrequency ablation (RFA) of metastatic lesions has been shown to be effective in bone. Spine anatomy presents challenges for minimally invasive (MI) treatment of posterior vertebral body lesions. Targeted RFA (t-RFA) using a novel tumor ablation system, designed for spinal anatomy is evaluated in patients with symptomatic posterior vertebral wall spinal lesions.

Five patients with metastatic leiomyosarcoma or liposarcoma and posterior vertebral body spine lesions, treated by prior radiation with continued progression of lesion size and pain received t-RFA, using a novel spinal tumor ablation system (STAR, DFINE), which contains an articulating bipolar, extensible electrode for navigation. Device thermocouples (TC) permit real time monitoring of the ablation zones to determine size. Sequential post-procedural pain scores, PET and contrast enhanced magnetic resonance imaging, and histopathology of treated area was performed.

No complications or thermal injury occurred. Intra-procedural imaging demonstrated the articulated, bipolar instrument was able to navigate to posterior lesions. Post-ablation MRI demonstrated lesion necrosis within a discrete ablation zone. No evidence of malignancy by PET or histopathology was noted through 10 months. All patients reported post procedural pain relief. Systemic therapy was not interrupted. (emphasis added)

Navigational t-RFA proved a safe and effective, non-ionizing palliative therapy alternative for radio-resistant lesions. Post-ablation imaging and histology confirmed metastatic lesions were necrotic and included in ablation zone with tumor control 10 mos post treatment. Ablation zone was very consistent with real time temperature readings. t-RFA permitted MI targeted treatment of lesions within close proximity of spinal cord, not controlled by systemic therapy. Prospective clinical trial is under preparation.



Physicians' insights on RF Ablation

STAR Tumor Ablation Procedure