Radiosurgery for Recurrent Brain Metastases after Whole-Brain Radiotherapy : Factors Affecting Radiation-Induced Neurological Dysfunction.
10.3340/jkns.2009.45.5.275
- Author:
Ho Shin GWAK
1
;
Hyung Jun YOO
;
Sang Min YOUN
;
Dong Han LEE
;
Mi Sook KIM
;
Chang Hun RHEE
Author Information
1. Neuro-Oncology Clinic, National Cancer Center, Goyang, Korea.
- Publication Type:Original Article
- Keywords:
Brain;
Metastasis;
Radiotherapy;
Toxicity;
Radiosurgery;
Recurrence
- MeSH:
Brain;
Disease-Free Survival;
Humans;
Incidence;
Neoplasm Metastasis;
Radiosurgery;
Recurrence;
Retrospective Studies;
Survival Rate;
Tumor Burden
- From:Journal of Korean Neurosurgical Society
2009;45(5):275-283
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: We retrospectively analyzed survival, local control rate, and incidence of radiation toxicities after radiosurgery for recurrent metastatic brain lesions whose initial metastases were treated with whole-brain radiotherapy. Various radiotherapeutical indices were examined to suggest predictors of radiation-related neurological dysfunction. METHODS: In 46 patients, total 100 of recurrent metastases (mean 2.2, ranged 1-10) were treated by CyberKnife radiosurgery at average dose of 23.1 Gy in 1 to 3 fractions. The median prior radiation dose was 32.7 Gy, the median time since radiation was 5.0 months, and the mean tumor volume was 12.4 cm3. Side effects were expressed in terms of radiation therapy oncology group (RTOG) neurotoxicity criteria. RESULTS: Mass reduction was observed in 30 patients (65%) on MRI. After the salvage treatment, one-year progression-free survival rate was 57% and median survival was 10 months. Age (<60 years) and tumor volume affected survival rate (p=0.03, each). Acute (< or =1 month) toxicity was observed in 22% of patients, subacute and chronic (>6 months) toxicity occurred in 21%, respectively. Less acute toxicity was observed with small tumors (<10 cm3, p=0.03), and less chronic toxicity occurred at lower cumulative doses (<100 Gy, p=0.004). "Radiation toxicity factor" (cumulative dose times tumor volume of <1,000 Gyxcm3) was a significant predictor of both acute and chronic CNS toxicities. CONCLUSION: Salvage CyberKnife radiosurgery is effective for recurrent brain metastases in previously irradiated patients, but careful evaluation is advised in patients with large tumors and high cumulative radiation doses to avoid toxicity.
