The Results of Gamma Knife Radiosurgery for Brain Metastases from Renal Cell Carcinoma |
Tae Yub Kim, Hyun Ho Jung, Jeong Han Kang, Jong Hee Chang, Jin Woo Chang, Yong Gou Park, Sang Sup Chung |
Department of Neurosurgery and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea, Department of Neurosurgery, Bundang CHA Hospital, CHA Medical University, Seongnam, Korea |
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Abstract |
Objective Renal cell carcinoma (RCC) is a rare tumor which tends to metastasize to the brain in about 4-11% of patients. Metastases from RCC raise specific therapeutic problems because they are relatively unresponsive to whole brain radiation therapy and tend to bleed. The aim of this study was to analyze the therapeutic effects after Gamma Knife radiosurgery (GKS) as a primary treatment for patients harboring brain metastases of RCC.
Methods Between May 1992 and September 2005, 26 patients with 102 brain metastases from RCC underwent 31 GKS procedures. Overall median survival, main cause of death, local control rate, and morbidity related to GKS were evaluated. Age, sex, performance status, number of metastases, volume of metastases, presenting symptom, prior history of craniotomy, fractionated radiation therapy, chemotherapy or immunotherapy, maximal dose, tumor marginal dose, number of treatment isocenters, recursive partitioning analysis (RPA) class, and latency period from diagnosis of RCC to that of brain metastases were statistically analyzed to identify significant factors related to prolonged survival and local control.
Results The mean tumor volume was 3.3 (0.02-35.1)cc. Mean maximal and tumor margin dose were 28.0 (15-43)Gy and 17.7 (9-26.6)Gy, respectively. The period of median survival was 10.5 months after GKS and RPA class was only significant factor related to survival. Local tumor control rate was 92.0% and tumor volume was related to local control. Radiation-related edema occurred in 8.9% of cases. Additional whole brain radiation therapy could not affect survival time, local tumor control, but could increase the risk of radiation-related complications. Local and distant tumor recurrences were treated by additional GKS. There was no permanent morbidity after GKS.
Conclusion Despite of the radioresistant nature of RCC, GKS alone could effectively control brain metastases from RCC not only as a primary treatment, but also as a secondary salvage treatment for recurrence. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including repeated radiosurgery without a combination of whole brain radiation therapy can offer patients an extended survival. |
Key Words:
Brain metastasis, Gamma Knife radiosurgery, Radioresistancy, Renal cell carcinoma. |
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