Stereotactic Radiosurgery Beneficial
SAN DIEGO—Stereotactic radiosurgery produces early and durable responses in renal cell carcinoma (RCC) patients with either previously untreated spinal metastases or spinal metastases that have recurred after prior radiotherapy, researchers announced here at the 2007 Annual Meeting of the American Academy of Orthopedic Surgeons.
The results are based on a study in which extracranial lesions in 24 RCC patients were treated with stereotactic radiosurgery of 2550 cGy at the 80% isodose line in three stages over a 20-month period. Fifteen patients had presented with spinal metastases, and seven of them had failed prior radiation. Nine patients had bone and soft tissue lesions, and two of them were radiation failures. Pain levels and tumor response were evaluated every three months.
Of the 15 patients with spinal metastases, 14 had pain relief at a mean of five days. Overall, three patients had complete regression of their lesion, five had partial regression, and seven had stable disease. Results were durable in 12 patients. The investigators defined durable as no recurrence of pain and no in-crease in size of the lesion during the follow-up period. The mean survival for the group was 12.3 months, and six of the 15 were alive at the time the data were reported.
Eight of the nine patients who presented for treatment of bone and soft tissue lesions had complete initial pain relief, and one had partial relief. One had complete lesion regression, five had partial regression, and three had stable disease. Three of the nine patients were alive when the data were presented and had a mean survival of 10 months. None of the three has had recurrent or worsening symptoms.
Noting that patients with metastatic RCC respond poorly to most standard treatment modalities, principal investigator Alan Marc Levine, MD, an orthopedic surgeon who is director of the Alvin and Lois Lapidus Cancer Institute in Baltimore, pointed out that the response rate and durability far ex-ceeded that achieved with external beam radiation.
"Thus, for patients with these highly vascular lesions in which it is often difficult to achieve local control without en bloc resection, stereotactic radiosurgery offers a less morbid alternative treatment and even in the spine, retreatment is possible with good response and no appreciable increased rate of complications," he said.