The STAR Tumor Ablation System for Metastatic Spinal Tumors: An Interview With Clifford Howard Jr., MD

Historically, treatment for painful spinal metastases has been conservative, with most providers relying on radiation or narcotic pain management. Radiofrequency ablation (RFA) with the STAR Tumor Ablation System (DFINE) was developed specifically for the palliative treatment of metastatic vertebral body tumors. The system received FDA 510(k) clearance in August 2010 and CE Mark approval in October 2013 for this application, which provides localized tumor necrosis of vertebral body lesions where metastatic disease has spread to the spine causing severe pain and discomfort. A recent study by Anchala et al showed that after treatment with the system, patients’ pain was reduced on average to 77%.¹ Interventional Oncology 360 spoke with Clifford Howard Jr., MD, assistant professor of radiology at Wake Forest Baptist Health in Winston-Salem, North Carolina, about use of the system.  

Q: Could you describe for us a little about the use of the STAR system for ablating spinal tumors?

A: The STAR Tumor Ablation System is a device designed specifically to treat painful spinal tumors by way of RFA. It’s safe, it’s relatively simple, and it’s an outpatient procedure. The therapy is very controlled and effective. 

I use an anesthesiology team to assist me in the procedure, however my patients usually only receive moderate sedation unless there is some other risk. Once the patient is comfortable and in the prone position lying face down on the table, we will identify a safe approach. 

One thing I like about the STAR System is that it’s unipedicular, which means we can navigate throughout the vertebral body from one side. I will choose the safest approach by first giving  a local anesthetic, and that is usually the most sensitive part of the exam, and then place the introducer cannula into the vertebral body either through the pedicle or adjacent to the pedicle. Once the  introducer cannula is in place in the vertebral body, I can insert the SpineStar instrument and  navigate to a specific tumor, or if the tumor has infiltrated the entire vertebral body, I can place it in multiple zones, to ablate the entire tumor for palliative pain relief, and secondarily, also kill the tumor. Once that’s complete, I’ll then fill the void created by the ablation  with  biological cement or bone cement (see video courtesy of DFINE, Inc.).

Q: Is STAR used palliatively only or are there other applications now?

A: The indication now is for palliative pain relief only, however this system also allows me to get a biopsy through the same needle, which is sometimes required  and also to place the cement for stability if a fracture is present or I feel the vertebra is unstable. It is important to remember that the patient has a primary cancer in other areas and this is used as a complement to their primary cancer treatment. And depending on the size and location of the tumor, I can either destroy large portions of it or sometimes all of it. The objective is to enable  a multidisciplinary  approach  to treating cancer, and patient symptoms. 

Q: In addition to anesthesiology, who else is on the team when doing a procedure?

A: In addition to myself, I have clinical support from DFINE, the device maker, the anesthesiologist  for sedation. I usually have a tech to assist with the equipment and sometimes either a nurse or second tech, just to help facilitate the flow of the case.

Q: Do you have any data that you can share that describes the efficacy and safety?

A: There are data to support that RF energy is an effective treatment for bone medicine. There are several studies that show the results of this procedure to be significant in terms of immediate pain relief and durable pain relief, meaning at 6 months post procedure the patient’s pain is still low in the treated area. Other studies suggest that when combined with other therapies such as external beam radiation or stereotactic beam radiation,  the patient will have even better results.² 

I also kept track of results for patients in my institution. In 9 months I’ve treated 20 patients with 31 tumors. In these patients, there has been a slightly greater than 80% decrease in pain at 2 months following the procedure.

Q: Are there locations in the spine that STAR is particularly good at treating vs other locations?

A: The thoracolumbar spine -- the midthoracic down to the sacrum -- and of course within the vertebral body is ideal. However, I have treated pedicle lesions with excellent results as well.

Q: Do you have any tips and tricks for interventional oncology clinicians to know about using the system?

A: Preprocedure and preoperative planning is most important. Operators should plan out ablation zones in three dimensions to treat the entire vertebral body. Planning ahead is important to determine where your introducer cannula is placed in order to achieve multiple ablation zones and the most cement, if needed. Having multiple zones for ablation is key. Post ablation, the operator then needs to determine whether to augment the bone with cement, however I always do.

Q: Does any particular case stand out to you?

A: I presented two cases recently. One was a 63-year-old gentleman who had a history of metastatic lung cancer, prostate, and renal cell cancer. He presented with a T7 compression fracture with bulging posterior body into the spinal canal pressing on the spinal cord. He did not have any neurologic deficits, however he was what we consider an ECOG 3. He was pretty much confined to his bed. It was too painful for him to get up and walk. He had already started radiation therapy with 6 of 10 courses without any improvement. 

I performed this t-RFA procedure and 4 hours post procedure he was walking. He had not gone to the bathroom on his own in 2 months, and the first thing he did was get up and walk to the bathroom, with assistance. His back brace was no longer required 7 days post procedure and he was discharged from the hospital 10 days post procedure. He finished radiation therapy and he finished his occupational therapy as well. This patient’s only other option was corpectomy or total removal of the vertebral body and placement of rods. That surgery would take 2 days, be extremely costly for the patient and the hospital, and increase risk of morbidity and mortality. In 45 minutes I was able to treat him and help with his pain and help him achieve a better quality of life. Those are the types of cases that have had excellent results. 

Oftentimes the pain relief is immediate and very significant. My patients usually begin at a score of  8 or 9 on a pain scale from 1 to 10, and immediately following the procedure they report a 2 or 3 and sometimes no pain at all in their spine. It is rewarding to see a man walking four hours after the ablation when prior to the procedure his pain was so severe he was unable to walk.

Q: Is there anything else that you wanted to add about the system and where you think it could be headed?

A: Yes, I think that as healthcare changes, and we start getting into these alternative and therapy options with oncology, that this procedure is an excellent  adjuvant therapy along with the primary cancer treatment. The current gold standard for metastatic spinal lesions is stereotactic beam radiation. I think that it won’t replace the other treatment modality, but rather it’s an effective complement to it. And I think that there is a potential for this to become another gold standard when used with  with radiation therapy. Using them both can achieve better results than with one treatment alone. It is often concurrently used now and is very successful, particularly when there are no other options for the patient. 

Editor’s note: Disclosure: The author has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr. Howard reports unpaid consultancy to DFINE, Inc.

Suggested citation: Ford J. The STAR Tumor Ablation System for Metastatic Spinal Tumors: An Interview With Clifford Howard Jr., MD. Intervent Onc 360. 2014;2(10):E70-E72.

References

1. Anchala PR, Irving WD, Hillen TJ, et al. Treatment of metastatic spinal lesions with a navigational bipolar radiofrequency ablation device: a multicenter retrospective study. Pain Physician. 2014;17(4):317-327.
2. Di Staso M, Zugaro L, Gravina GL, et al. A feasibility study of percutaneous radiofrequency ablation followed by radiotherapy in the management of painful osteolytic bone metastases. Eur Radiol. 2011;21(9):2004-2010.