CT-guided radiofrequency ablation offers long-term pain reduction in patients with osteoid osteoma, making it a viable alternative to open surgery, according to researchers from Seoul.
"Surgery is considered if pain persists, but open surgical excision is known to have high morbidity and recurrence is not uncommon," said Dr. Ki Sun Sung, Ph.D., and colleagues from Sungkyunkwan University School of Medicine and Samsung Medical Center.
The retrospective study from Korea, presented at the 2007 American Academy of Orthopaedic Surgeons meeting, focused on 28 osteoid osteoma patients who did not respond to conservative treatment with anti-inflammatory drugs between 1995 and 2005. They underwent RFA and at least two years of follow-up.
Of the 28 patients, 26 had primary tumors and two had recurring disease. The nidus size ranged from 2 to 14 mm in diameter. During CT-guided RFA, the lesion was heated to 80° to 90°C for an average of 6.5 minutes.
The results found RFA to be technically successful in 27 cases. There was one skin burn complication, Sung said. All patients were discharged 1.8 days after the procedure. At two years post-RFA, 90% of the patients said they had experienced a complete loss of symptoms.
An additional RFA procedure was required in three subjects, for a recurrence rate of about 10%. These patients stated that they experienced pain relief after the second round of treatment. All remained symptom-free six years after RFA.
Sung told Diagnostic Imaging that he did not know why the initial RFA procedure in these three patients was unsuccessful. He hypothesized that the heat did not reach the nidus, most likely because of inadequate electrode positioning or other technical errors. His group found no correlation between nidus size and recurrence, however.
AAOS session moderator Dr. John Ready pointed out that RFA is often reserved for lesions that are deemed surgically inaccessible rather than untreatable by conventional methods. Sung responded that the main criterion for RFA patient selection at his institution was nonresponsiveness to conservative treatment. Open excision treatment for osteoid osteoma has not been performed at his medical center for the last seven years, he said.
More details on Sung and coauthors' study can be found in a paper published in the November 22, 2007 issue of International Orthopaedics.
For more information from the Diagnostic Imaging archives:
RFA of chondroblastomas offers efficacious alternative to surgery
Image-guided ablation eases bone tumor pain
Percutaneous ablation treats bone tumors safely, effectively
