Local Control Of Brain Metastases Research Articles

Gamma knife radiosurgery for brain metastases: prognostic factors for survival and local control

Object. The authors conducted an analysis of prognostic factors for patient survival and local control of brain metastases after gamma knife radiosurgery. Methods. In the survival analysis, 53 consecutive patients with 121 lesions treated in the last 2 years were examined. Common primary sites were lung (26 patients), kidney (seven), breast (three), and colon (three). Patient age ranged from 28 to 75 years (median 58 years) and the female/male ratio was 1:0.9. The median tumor volume was 2.1 cm3 (range 0.02–45.5cm3) and the average prescription dose was 15.4 Gy to the 50% isodose. The median follow up was 12 months (range 1–23 months) and the median survival was 46 weeks. Six-month and 1-year survival rates were 63% and 39%, respectively. Karnofsky Performance Scale score, tumor volume, and presence of extracranial disease were statistically significant prognostic factors (p < 0.05) for survival in multivariate analysis. Number of lesions, patient age, and adjuvant whole-brain radiation therapy were not statistically significant. Ninety-one of 121 lesions with follow-up images were included in the local control analysis. The 1-year actuarial local control rate was 48%. In multivariate analysis smaller volume was associated with better control (p = 0.0043), and, control period of renal cell carcinoma was shorter than that of the other tumor types (p = 0.0070). Conclusions. Karnofsky Performance Scale score, tumor volume, controlled primary cancer, and absence of extracranial metastases were associated with longer survival in the present study. For local control, tumor volume was a statistically significant factor.

Prognostic factors in brain metastases: should patients be selected for aggressive treatment according to recursive partitioning analysis (RPA) classes?

Purpose: To determine whether or not Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) derived prognostic classes for patients with brain metastases are generally applicable and can be recommended as rational strategy for patient selection for future clinical trials. Inclusion of time to non-CNS death as additional endpoint besides death from any cause might result in further valuable information, as survival limitation due to uncontrolled extracranial disease can be explored. Methods: We performed a retrospective analysis of prognostic factors for survival and time to non-CNS death in 528 patients treated at a single institution with radiotherapy or surgery plus radiotherapy for brain metastases. For this purpose, patients were divided into groups with Karnofsky performance status (KPS) <70% and KPS ≥70%, as proposed by the RTOG. Results: Median overall survival was 2.9 months (2.0 months for patients with KPS <70% and 3.6 months for patients with KPS ≥70%, p < 0.001). We did not find other variables splitting patients with KPS <70% in different prognostic groups. However, advanced age, multiple brain metastases, presence of extracranial metastases, and uncontrolled primary tumor each predicted shorter survival in patients with KPS ≥70%. When grouped into the original RTOG RPA classes, our data set split into three subgroups with different prognosis and median survival times of 10.5, 3.5, and 2 months, respectively ( p < 0.05). Only 3% of patients fell into the most favorable group. Median time to non-CNS death was 4.1 months (12.9 months in RPA class I, 4.9 months in RPA class II, and 3.8 months in RPA class III, respectively, p > 0.05 for RPA class II versus III). However, it was 8.5 months in RPA class II patients with controlled primary tumor, which was found to be the only prognostic factor for time to non-CNS death in patients with KPS ≥70%. In patients with KPS <70%, no statistically significant prognostic factors were identified for this endpoint. Conclusions: Despite some differences, this analysis essentially confirmed the value of RPA-derived prognostic classes, as published by the RTOG, when survival was chosen as endpoint. RPA class I patients seem to be most likely to profit from aggressive treatment strategies and should be included in appropriate clinical trials. However, their number appears to be very limited. Considering time to non-CNS death, our results suggest that certain patients in RPA class II also might benefit from increased local control of brain metastases.

The role of the gamma knife in the treatment of malignant primary and metastatic brain tumors.

Gamma knife treatment is a clinically effective, safe, and cost-effective adjunctive therapy for primary malignant brain tumors. For most brain metastases, radiosurgery is the treatment of choice and will result in effective tumor control in more than 90% of treated tumors.

Radiosurgery for brain metastases: Relationship of dose and pattern of enhancement to local control

Purpose : This study aimed to analyze dose, initial pattern of enhancement, and other factors associated with freedom from progression (FFP) of brain metastases after radiosurgery (RS). Methods and Materials : All brain metastases treated with gamma-knife RS at the University of California, San Francisco, from 1991 to 1994 were reviewed. Evaluable lesions were those with follow-up magnetic resonance or computed tomographic imaging. Actuarial FFP was calculated using the Kaplan-Meier method, measuring FFP from the date of RS to the first imaging study showing tumor progression. Controlled lesions were censored at the time of the last imaging study. Multivariate analyses were performed using a stepwise Cox proportional hazards model. Results : Of 261 lesions treated in 119 patients, 219 lesions in 100 patients were evaluable. Major histologies included adenocarcinoma (86 lesions), melanoma (77), renal cell carcinoma (21), and carcinoma not otherwise specified (17). The median prescribed RS dose was 18.5 Gy (range, 10–22) and the media tumor volume was 1.3 ml (range, 0.02–30.9). The initial pattern of contrast enhancement was homogeneous in 68% of lesions, heterogeneous in 12%, and ring-enhancing in 19%. The actuarial FFP was 82% at 6 months and 77% at 1 year for all lesions, and 93 and 90%, respectively, for 145 lesions receiving ≥ 18 Gy. Multivariate analysis showed that longer FFP was significantly associated with higher prescribed RS dose, a homogeneous pattern of contrast enhancement, and a longer interval between primary diagnosis and RS. Adjusted for these factors, adenocarcinomas had longer FFP than melanomas. No significant differences in FFP were noted among lesions undergoing RS for recurrence after prior radiotherapy (119 lesions), RS alone as initial treatment (45), or RS boost (55). Conclusion : A minimum prescribed radiosurgical dose ≥ 18 Gy yields excellent local control of brain metastases. The influence of pattern of enhancement on local control, a new finding in this retrospective analysis, needs to be confirmed.

Stereotactic radiosurgery of malignant and benign intracranial lesions utilizing a patient rotator.

This study examines the characteristics of the patient groups, treatment parameters, and results of therapy for 126 intracranial lesions treated with stereotactic radiosurgery utilizing a "patient rotator" and a linear accelerator. A retrospective review was conducted and data on 122 patients (21 patients with arteriovenous malformations-AVMs, 40 patients with 41 metastatic tumors, 24 patients with malignant gliomas and 37 patients with other benign lesions) were analyzed. Clinical and radiographic response was obtained from chart review and/or telephone follow-up. The average follow-up was 12.1, 13.0, 5.7, and 23.1 months in patients with AVMs, malignant gliomas, metastases, and other lesions, respectively. Median survival times (MST) of the metastatic and glioma group were 9 and 38 months, respectively. Complete or partial radiographic response at follow-up was seen in 62.5% of AVM patients, 33.3% of patients with metastases, 11.8% of patients with malignant gliomas, and 19.3% of patients with other lesions. (1) Local control of brain metastases and benign intracranial lesions can be obtained with single dose stereotactic radiosurgery. (2) The MST and local control rate for metastatic disease obtained are comparable with those in the literature. (3) The patient rotator method for stereotactic radiosurgery is an effective tool for treating selected intracranial lesions.