Focused Ultrasound Can Lessen Cancer Pain

When cancer advances and metastasizes to the bone, patients often suffer debilitating pain. Now, a new phase III clinical trial shows that noninvasive magnetic resonance-guided focused ultrasound treatment that heats the cancer within the bone relieves pain and improves function for most patients when other treatment alternatives are limited.

The study’s findings were first published online April 23, 2014, in the Journal of the National Cancer Institute (JNCI).Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is a technique that is been safely used to treat thousands of women with uterine fibroids. However, “this is the first phase III study to use this technology in the treatment of cancer,” noted the study’s principal investigator and lead author Mark Hurwitz, MD, vice chairman of quality, safety, and performance and director of thermal oncology in the department of radiation oncology at Thomas Jefferson University (Philadelphia, PA, USA).

Although radiotherapy is typically used to treat bone-related pain and effective for most patients, not all patients experience pain relief and over time those who do may have recurrence of pain. In addition, it's possible for a patient to receive the maximum radiation dose that can be safely delivered without fully controlling the pain. In situations where radiation therapy is not an option, alternative treatments are required.

A total of 147 patients from 17 centers in the US, Canada, Israel, Italy, and Russia were enrolled in the study and randomized to undergo MRgFUS or a sham treatment. Patients in the treatment group received focused ultrasound precisely targeted to their bone tumors to heat the tumor tissue to between 65 °C and 85 °C, resulting in its obliteration. During each treatment, the patients were tracked real-time via magnetic resonance imaging (MRI) to make sure the appropriate tissue was targeted and the right temperatures were reached while ensuring heat in surrounding normal tissues and organs remained at safe levels. The control group underwent the same procedure but without the ultrasound device turned on. Finally, patients who did not respond to the placebo treatment within two weeks were allowed to be unblinded and offered MRgFUS.

Patients responded well to treatment, with 64% experiencing either no pain or a significant reduction in their pain at three months as gauged by a 2 point or greater decrease in the numeric rating score (NRS) for pain, a clinically validated measurement tool. Many patients were able to reduce or stop use of opiod medications. Significantly, most patients experienced pain relief and improved functioning within several days of treatment. “It’s clear that for many of these patients, pain has a major impact on their everyday lives," says Dr. Hurwitz. “This approach offers a new way to help alleviate that pain via an out-patient noninvasive procedure.”

The next phase in this research, according to Dr. Hurwitz, is to modify the treatment technique to get an even greater response rate, and to apply radiation and thermal therapy together in treatment of bone metastases noting the established clinical benefits for other malignant conditions with this combination. To achieve this, Dr. Jefferson has established a new program for thermal oncology within its department of radiation oncology to provide patients with access to thermal therapies that have been shown to augment radiation treatment.

“The work provides cancer patients with more options for treatment of cancer pain and the opportunity for patients to reduce opioid use, which has significant side effects,” said Adam Dicker, MD, PhD, chair of Jefferson’s department of radiation oncology, and not involved in the study.

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