Three nonsurgical treatments--- osteoplasty, radiofrequency ablation, and cryoablation, may each be able to decrease pain associated with bone metastases by as much as 74-89 percent, according to presentations at the annual meeting of the Society of Interventional Radiology.

“Pain affects greater than 60 percent of patients with advanced cancer and for many the pain is due to bone metastases, often destroying the quality of their remaining life. This research shows these new interventional techniques are effective to help these patients without surgery, and offer a short recovery time. The treatments work within weeks, are well-tolerated and can be repeated if needed,” said Matthew Callstrom, MD, PhD, of the Mayo Clinic, Rochester, Minnesota.

Cryoablation kills targeted tissue by freezing it with Argon gas in a sealed probe, while sparing nearby healthy tissue. Because of the localized nature of the treatment, it does not have any systemic side effects. Computed tomography (CT) and/or ultrasound imaging can be used to guide up to 8 probes through the skin into the tumor under anesthesia. The “ice ball” that is created around the probe, visible with CT imaging, grows in size and destroys the frozen tumor cells. The advance in this technique is due to decreased probe size and structure allowing probes to be placed without need of surgery or even sutures.

In the first prospective trial to evaluate safety and efficacy of percutaneous cryoablation for palliation of painful metastatic lesions, 8 of 10 patients completed a 24-week follow-up with an average 74-percent reduction in worst pain; full enrollment will involve 30 adult patients.

In radiofrequency ablation, heat is delivered directly into the tumor via a probe that is inserted percutaneously with CT or ultrasound imaging for guidance. Like cryoablation, radiofrequency ablation can be performed without affecting the patient’s overall health and most people can resume their usual activities in a few days.

The current study showed that pain relief was achieved within a week for all 11 patients who underwent the technique. According to the visual analogue pain scale (VAS), patients’ pain was reduced by 2 or more points on a 10-point scale. Mean scores decreased dramatically from 6.4 to 0.7. No patients experienced local recurrent pain during a mean follow-up period of 5 months.

Osteoplasty treats bone pain by injecting medical-grade bone cement into the tumor. The cement gives off heat when mixed which kills the tumor, and then hardens to reinforce weakened bone that otherwise would be susceptible to fracture. Tumors often eat away healthy bone and in weight-bearing bones, this can be a particularly useful technique because it can prevent fracture. This is an established technique used to treat painful vertebral metastases or fractures in the spine from osteoporosis. Most recently, interventional radiologists have adapted this technique to other bones in the body.

Osteoplasty is performed using conscious sedation. The interventional radiologist inserts a needle through a small incision in the back, directing it under fluoroscopy into the tumor. The physician then injects medical-grade bone cement that hardens within about 15 minutes.

The current study showed that osteoplasty is safe and effective for unremitting cancer pain and provided prompt and dramatic pain relief and return to function. Three men and two women were treated for malignant disease, and two women and one man for benign disease, for a total of 8 patients. The treatment was successful in all 8 patients, who experienced prompt and lasting pain relief. Additionally, there were no significant complications.