Nonsurgical therapies mitigate pain from bone tumors

Thermal ablation and osteoplasty alleviate the unbearable pain associated with tumors of the bone. The minimally invasive techniques could significantly improve life quality for terminal cancer patients, according to studies presented at the 2005 Society of Interventional Radiology meeting earlier this month.

Tens of thousands of patients in the U.S. alone develop primary and metastatic bone tumors each year. These lesions cause severe pain that narcotics and other treatments cannot relieve. Even radiation therapy - with a proven record for pain palliation - may fail over time or not work at all, said author Dr. Matthew Callstrom, an interventional radiologist at the Mayo Clinic in Rochester, MN.

"You can reduce the pain for patients with narcotics. But that often means they are sleeping through much of the day and get through from narcotic dose to narcotic dose. This has a significant impact on their quality of life," he said.

Callstrom and colleagues at the Mayo Clinic have treated 10 patients with pain from primary and metastatic bony lesions using percutaneous cryoablation. These patients had either failed chemo- or radiotherapy or were poor candidates. The researchers found cryoablation significantly safe and efficacious in relieving these patients' pain.

Eighty-percent of patients treated to date have sustained an average 74% reduction of the worst pain at follow-up in the first prospective trial of percutaneous cryoablation. The study is ongoing, and the researchers plan to enroll a total of 30 patients.

Starting in February 2003, Dr. Atsuhiro Kakatsuka and colleagues in the radiology department of the University School of Medicine of Mie, Japan, treated 18 bone metastases from hepatocellular carcinoma in 11 patients using radiofrequency ablation. They found patients achieved pain relief in a relatively short period of time and remained pain-free for nearly six months.

The investigators evaluated pain relief using the 10-point Visual Analogue Scale (VAS) scoring system, defining technical success as a decrease by two points or greater. They found a statistically significant decrease in the mean VAS score in all patients (p

In the osteoplasty study, Dr. Anthony G. Ryan and colleagues at the Vancouver General Hospital in British Columbia assessed five patients with malignancies and three with benign tumors. Lesions affected the sacrum, acetabulum, ischium, and pubis, some presenting with significant technical challenges for the injection of bone cement into the tumor. The investigators found that all patients experienced prompt and lasting relief without significant complications.

Physicians speculate that the intense heat osteoplasty gives off as the bone cement hardens probably relieves pain by cauterizing the lesion's extensions to neural tissue. The cement stabilizes microfractures produced by tumors and helps strengthen weak bones.

The studies validate previous trials of thermal ablation devices used to ease pain caused by large bone metastases, with efficacy rates exceeding 90%. These new interventional treatments offer a significant improvement in quality of life to affected patients, especially those who have been disabled from their pain and rendered unable to perform everyday activities without an excruciating reminder of their illness, Callstrom said.

Minimally invasive treatment cannot change the ultimate outcome nor offer hopes for terminally ill patients, but it provides valuable improvement to their last days, according to Callstrom.

"In the time they have, they come back and join the family," he said.

For more information from the Diagnostic Imaging archives:

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