How to assess active contact coordinates in deep brain stimulation surgery? Comparison of three methods for determining the position of the active contact.

To date there is still no agreement in the literature on postoperative active contact coordinate (ACc) acquisition. The aim of the study is to test if the use of three methods commonly adopted in the literature for ACc acquisition (stereotactic X-rays (RXc), postoperative MRI (MRIc) and calculation of the expected ACc) for the same active contact (ACo) lead to significant differences. In our series of 176 ACo, mean euclidean distances were 1.2 +/- 0.3, 2.1 +/- 1.3, and 2.5 +/- 1.6 mm between MRIc and RXc, RXc and EXc, and MRIc and EXc, respectively. Statistically significant differences along the three axes were found. Our results indicate that final ACc depends on the method adopted to acquire them. MRI and X-rays lead to a similar ACc acquisition. The difference between the EXc and the direct visualization methods (X-rays and MRI) is significantly higher.

Stereotactic drainage and Gamma Knife radiosurgery of cystic brain metastasis.

OBJECT: Treatment options for patients with brain metastasis include tumor resection, whole-brain radiation therapy, and radiosurgery. A single treatment is not useful in cases of multiple tumors, of which at least 1 is a cystic tumor. The purpose of this study was to assess the role of stereotactic drainage and Gamma Knife surgery (GKS) in the treatment of cystic brain metastasis. METHODS: Between January 2001 and November 2005, 680 consecutive patients with brain metastases underwent GKS at our hospital, 30 of whom were included in this study (18 males and 12 females, mean age 60.6 +/- 11 years, range 38-75 years). Inclusion criteria were: 1) no prior whole-brain radiation therapy or resection procedure; 2) a maximum of 4 lesions on preoperative MR imaging; 3) at least 1 cystic lesion; 4) a Karnofsky Performance Scale score >or= 70; and 5) histological diagnosis of a malignant tumor. RESULTS: Non-small cell lung carcinoma was the primary cancer in most patients (19 patients [63.3%]). A single metastasis was present in 13 patients (43.3%). There was a total of 81 tumors, 33 of which were cystic. Ten patients (33.3%) were in recursive partitioning analysis Class I, and 20 (66.6%) were in Class II. Before drainage the mean tumor volume was 21.8 ml (range 3.8-68 ml); before GKS the mean tumor volume was 10.1 ml (range 1.2-32 ml). The mean prescription dose to the tumor margin was 19.5 Gy (range 12-25 Gy). Overall median patient survival was 15 months. The 1- and 2-year survival rates were 54.7% (95% confidence interval 45.3-64.1%) and 34.2% (95% confidence interval 23.1-45.3%). Local tumor control was achieved in 91.3% of the patients. CONCLUSIONS: The results of this study support the use of a multiple stereotactic approach in cases of multiple and cystic brain metastasis.

Neuroophthalmological evaluation after Gamma Knife surgery for cavernous sinus meningiomas.

OBJECT: Treatment options for patients with cavernous sinus meningiomas (CSMs) include microsurgical tumor resection, radiotherapy, and radiosurgery. Gamma Knife surgery (GKS) is increasingly being used because it is associated with lower mortality and morbidity rates than microsurgery. The purpose of this study was to assess the role of GKS in the treatment of CSM and to thoroughly analyze the clinical response to GKS. METHODS: Between January 2001 and December 2005, 123 patients (25 men and 98 women; mean age 62.6 +/- 11 years, range 31-86 years) who underwent treatment for CSMs were included in this study. Of these, 41 patients underwent microsurgery before GKS, whereas the remaining 82 had GKS as a first-line therapy after a diagnosis was made based on magnetic resonance imaging findings. Dysfunction in cranial nerves (CNs) II, III, IV, V, and VI was noted in 74 patients at the time of GKS. The mean tumor volume was 7.99 cm(3) (0.7-30.5 cm(3)). The mean prescription dose to the tumor margin was 13.8 +/- 1.1 Gy (range 10-20 Gy). RESULTS: The overall tumor control rate was 98.4% with a median follow-up of 36 months. The actuarial tumor control rate at 5 years was 90.5%. A reduction in tumor volume was observed in 53 patients (43.1%), whereas in 68 patients (55.3%) no volumetric variation was recorded. Of the 74 patients who presented with CN deficits, improvement was noted in 23 (31.1%). CONCLUSIONS: Gamma Knife surgery is a useful treatment for CSM both as a first- or second-line therapy. It is a safe and effective treatment for tumors located close to the optic pathways.

Evaluation of different score index for predicting prognosis in gamma knife radiosurgical treatment for brain metastasis.

PURPOSE: To assess the utility of the Radiation Therapy Oncology Group Recursive Partitioning Analysis (RPA) and Score Index for Radiosurgery (SIR) stratification systems in predicting survival in patients with brain metastasis treated with Gamma Knife radiosurgery (GKRS). METHODS AND MATERIALS: A total of 185 patients were included in the study. Patients were stratified according to RPA and SIR classes. The RPA and SIR classes, age, Karnofsky Performance Status (KPS), and systemic disease were correlated with survival. RESULTS: Five patients were lost to follow-up. Median survival in patients in RPA Class 1 (30 patients) was 17 months; in Class 2 (140 patients), 10 months; and in Class 3 (10 patients), 3 months. Median survival in patients in SIR Class 1 (30 patients) was 3 months; in Class 2 (135 patients), 8 months; and in Class 3 (15 patients), 20 months. In univariate testing, age younger than 65 years (p = 0.0004), KPS higher than 70 (p = 0.0001), RPA class (p = 0.0078), SIR class (p = 0.0002), and control of the primary tumor (p = 0.02) were significantly associated with improved outcome. In multivariate analysis, KPS (p < 0.0001), SIR class (p = 0.0008), and RPA class (p = 0.03) had statistical value. CONCLUSIONS: This study supports the use of GKRS as a single-treatment modality in this selected group of patients. Stratification systems are useful in the estimation of patient eligibility for GKRS. A second-line treatment was necessary in 30% of patients to achieve distal or local brain control. This strategy is useful to control brain metastasis in long-surviving patients.