CHICAGO – Pulsed radiofrequency, delivered into the back with a needle so thin that anesthesia is not required, gave patients relief of their back, leg, and sciatica pain that lasted a year or more, researchers reported here.
One year following the use of pulsed radiofrequency plus steroid injections, 95% of the 113 patients in the study reported that they had achieved relief of their leg pain compared with 61% of 116 patients who had injections only (P<0.001), according to Alessandro Napoli, MD, PhD, of Sapienza University of Rome.
"With just a single injection using pulsed radiofrequency, the pain scores went down and quality-of-life scores improved," Napoli said at the .
"Spine interventions are very common in our community because technology now allows us to use probes very close to the neurostructure instead of going directly into the disc hernia," he told 鶹ý. Using imaging guidance, debulking of the hernia and injections of steroids offered some pain relief, but not a complete cure, he said.
"With our new technology, we used pulsed radiofrequency – which has been used for decades in medicine," Napoli explained. "Our probe is so tiny that you do not need anesthesia. You can insert the needle through real-time image guidance that gives us a resolution of 0.5 mm. We use the precision of the CT-scan to get as close as we can to the nerve root.
"Once we are there, we insert the probe, which has an antenna at the tip," he continued. "We use it to create a very gentle energy field without increasing temperature. It is not clear yet how it occurs, but it appears that these energy fields interact with the nerve, kicking out the inflammation process within the nerve; without inflammation, the patient is no longer in pain and the muscles around the treated site relax, allowing the body to heal itself. Herniation does resolve itself, but it can take a long time, sometimes years.
"We give the probe 10 minutes of this very gentle pulse and the patient may feel nothing," Napoli said. "After the 10 minutes of pulsed radiation, we take advantage of the position of the needle and introduce a small amount of steroid."
He acknowledged that there is a question of whether the effect seen is due to the pulsed radiofrequency or the steroid injection, so he and his colleagues conducted the study to compare the modalities, and the combination approach was a clear winner, he said.
"More than 90% of our patients indicated they had received clinical benefit from the combination, and 80% of these patients were pain-free after a year. In the steroid injection-only group, 65% reported clinical benefit after 1 year and 55% were pain free," Napoli said.
The benefit was significantly better with pulsed radiofrequency at 4 weeks, 12 weeks, and 52 weeks compared with the results for steroid injection alone, the team reported.
"Pulsed energy to treat acute lower back pain is safe and effective," Napoli said. "Pulsed radiofrequency creates a nerve modulation, significantly reducing inflammation and its associated symptoms. Given our study results, we offer pulsed radiofrequency to patients with a herniated disk and sciatic nerve compression whose symptoms do not benefit from conservative therapy. Of the different therapies available, pulsed radiofrequency is among the least invasive," he explained.
Max Wintermark, MD, chief of neuroradiology at Stanford University in California, who was not involved with the research, told 鶹ý, "When a patient has lower back pain or sciatica, you can do surgery, but there are a number of patients who do not have good outcomes after surgery. As many as 15% of patients who undergo back surgery for these problems do not have a good outcome. So, if you can find something that is not as invasive, it would really be desirable. We can also do injections with CT guidance, but the limitation with that is that the duration isn't that long and it can vary from a few weeks to several months for different patients," he explained.
"So, here they did this radiofrequency in addition to steroids, and the perceived relief has gone out to at least 1 year, which is a good amount of time," Wintermark continued. "Almost everyone who received the radiofrequency treatment had improvement after a year."
He said he was interested in learning exactly how radiofrequency works in these patients, but also acknowledged that scientists don't really have a good understanding of the mechanisms underlying back pain, either.
Wintermark added that he would like to see studies with more patients and with longer follow-up. "How is this after two years? The longer the effect persists, the more convinced I would be that this does work," he said.
Disclosures
Napoli reported having no relevant relationshps with industry.
Wintermark reporting having no relevant relationships with industry.
Primary Source
Radiological Society of North America
Napoli A, et al "T Guided Pulsed Radiofrequency in Patients with Acute Low Back Pain and Sciatica: 1 Year Follow-Up versus Image-Guided Injection Only as Control Group," RSNA 2018.