Gamma Knife Radiosurgery on the Trigeminal Root Entry Zone for Idiopathic Trigeminal Neuralgia: Results and a Review of the Literature

Frameless Fractionated Gamma Knife Radiosurgery with ICON™ for Large Metastatic Brain Tumors

BACKGROUND: Recently, a new generation of gamma knife radiosurgery (GKRS) equipped with a frameless immobilization system has encouraged the use of fractionated GKRS as an increasingly favorable treatment option. We investigated the preliminary outcome of efficacy and toxicity associated with frameless fractionated gamma knife radiosurgery (FF GKRS) for the treatment of large metastatic brain tumors. METHODS: Fifteen patients with 17 lesions were treated using FF GKRS and included in this study, because of the large tumor size of more than 10 cm3. FF GKRS was performed based on a thermoplastic mask system for 3 to 5 consecutive days. RESULTS: The mean duration of clinical follow-up was 12 months (range, 4–24), and the local control rate was 100%. Tumor volume decreased in 13 lesions (76.5%), and remained stable in 4 lesions (23.5%). One patient was classified as new lesion development because of the occurrence of leptomeningeal seeding regardless of the tumor volume change. Compared with the initial volume at the time of FF GKRS, tumor volume change at the last follow-up was 62.32% ± 29.80%. Cumulative survival rate at 12 months was 93.3% ± 6.4%. One patient died during the follow-up period because of the progression of the primary disease. No patient showed radiation necrosis on the follow-up images. CONCLUSION: Daily FF GKRS by gamma knife ICON™ revealed satisfactory tumor control rate and low morbidity, despite the short follow-up period. Further prospective studies and a longer follow-up of a large cohort of patients diagnosed with brain metastases are required to elucidate the effect of FF GKRS in brain metastases.

Gamma Knife Radiosurgery for ARUBA-Eligible Patients with Unruptured Brain Arteriovenous Malformations

BACKGROUND: A randomized trial of unruptured brain arteriovenous malformations (ARUBA) reported superior outcomes in conservative management compared to interventional treatment. There were numerous limitations to the study. This study aimed to investigate the efficacy of gamma knife radiosurgery (GKS) for patients with brain arteriovenous malformations (AVMs) by comparing its outcomes to those of the ARUBA study. METHODS: We retrospectively reviewed ARUBA-eligible patients treated with GKS from June 2002 to September 2017 and compared against those in the ARUBA study. AVM obliteration and hemorrhage rates, and clinical outcomes following GKS were also evaluated. RESULTS: The ARUBA-eligible cohort comprised 264 patients. The Spetzler-Martin grade was Grade I to II in 52.7% and III to IV in 47.3% of the patients. The mean AVM nidus volume, marginal dose, and follow-up period were 4.8 cm³, 20.8 Gy, and 55.5 months, respectively. AVM obliteration was achieved in 62.1%. The annual hemorrhage rate after GKS was 3.4%. A stroke or death occurred in 14.0%. The overall stroke or death rate of the ARUBA-eligible cohort was significantly lower than that of the interventional arm of the ARUBA study (P < 0.001) and did not significantly differ from that of the medical arm in the ARUBA study (P = 0.601). CONCLUSION: GKS was shown to achieve a favorable outcome with low procedure-related morbidity in majority of the ARUBA-eligible patients. The outcome after GKS in our patients was not inferior to that of medical care alone in the ARUBA study. It is suggested that GKS is rather superior to medical care considering the short follow-up duration of the ARUBA study.

The Effect of Pain Reduction during Headframe Fixation for Stereotactic Radiosurgery by the Preceded Local Anesthesia under the Needle Cap Guidance

BACKGROUND: Gamma knife radiosurgery (GKRS) has become a major alternative in the neurosurgical field. However, many patients complained of considerable discomfort during the fixation of rigid headframe. This study investigated whether our modified procedure could reduce fixation-related pain. METHODS: Sixty-six patients who underwent GKRS were enrolled in this study. Thirty-one patients (Group A) underwent the conventional subcutaneous infiltration technique, and 35 patients (Group B) did the modified procedure. In group A, the headframe was held in position by an assistant, and local anesthetics were injected subcutaneously using a 23-gauge spinal needle at pinning sites. Subsequently, pins were applied according to measurements based on spinal needle depth. In group B, with the frame held in position by an assistant, pin sites were marked with a surgical pen under the guidance of needle cap placed on the pin holes. The head frame was then removed, and local anesthetics were injected subcutaneously and periosteally at each marked pin site using a 26-gauge needle. The headframe was then repositioned 5 minutes after local infiltration, and pins were applied according to measurements based on spinal needle depth. To evaluate pain severity during procedures, visual analogue scale (VAS) scores were recorded during local infiltration and frame placement with pins. The pain scores of the two groups were analyzed statistically. RESULTS: Group B had a significantly lower VAS score during frame placement than group A (7.26 vs. 3.61; p<0.001), and mean VAS score at local infiltration was also significantly lower in group B (4.74 vs. 3.74; p=0.008). CONCLUSION: Patients in group B experienced significantly less pain than those in group A during pin placement. Pre-fixation time advanced local anesthesia might reduce pain during stereotactic procedures, and the use of a 26-gauge needle appeared in less pain during local infiltration.

Gamma Knife Radiosurgery in Recurrent Trigeminal Neuralgia after Other Procedures / 고신대학교의과대학학술지

OBJECTIVES: Trigeminal neuralgia (TN) is undurable paroxysmal pain in the distribution of the fifth cranial nerve. Invasive treatment modalities for TN include microvascular decompression (MVD) and percutaneous procedures, such as, radiofrequency rhizotomy (RFR). Gamma Knife radiosurgery (GKRS) is a considerable option for patients with pain recurrence after an initial procedure. This study was undertaken to analyze the effects of gamma knife radiosurgery in recurrent TN after other procedures. METHODS: Eleven recurrent TN patients after other procedures underwent GKRS in our hospital from September 2004 to August 2016. Seven patients had previously undergone MVD alone, two underwent MVD with partial sensory rhizotomy (PSR), and two underwent RFR. Mean patient age was 60.5 years. We retrospectively analyzed patient's characteristics, clinical results, sites, and divisions of pain. Outcomes were evaluated using the Visual Analog Scales (VAS) score. RESULTS: Right sides were more prevalent than left sides (7:4). The most common distribution of pain was V1 + V2 division (n = 5) following V2 + V3 (n = 3), V2 (n = 2), and V1 + V2 + V3 (n = 1) division. Median GKRS dose was 80 Gy and the mean interval between the prior treatment and GKRS was 74.45 months. The final outcomes of subsequent GKRS were satisfactory in most cases, and at 12 months postoperatively ten patients (90.0%) had a VAS score of ≤ 3. CONCLUSIONS: In this study, the clinical result of GKRS was satisfactory. Invasive procedures, such as, MVD, RFR are initially effective in TN patients, but GKRS provides a safe and satisfactory treatment modality for those who recurred after prior invasive treatments.

Prognostic Analysis of EGFR-TKIs Combined with Gamma Knife in EGFR-mutant Lung Adenocarcinoma with Brain Metastasis / 中国肺癌杂志

BACKGROUND@#Advanced epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma had a high overall incidence of brain metastasis during the full course, and local brain radiotherapy combined with systemic targeted therapy may be a better strategy. This study aimed to identify the prognostic factors of EGFR-mutant brain-metastatic lung adenocarcinoma patients who received EGFR-tyrosine kinase inhibitors (EGFR-TKIs) in combination with gamma knife radiosurgery.@*METHODS@#Retrospective analysis of EGFR-mutant lung adenocarcinoma patients with brain metastases which developed at initial diagnosis or during EGFR-TKIs treatment period were performed. Intracranial progression free survival (PFS) was statistically analyzed between different subgroups to find out the prognostic factors including gender, age, smoking history, extracranial metastasis, EGFR mutation type, size and number of intracranial lesions, carcino-embryonic antigen (CEA) level, lung-molGPA score and so on.@*RESULTS@#A total of 74 EGFR-mutant brain-metastatic lung adenocarcinoma patients were enrolled in this study, with median intracranial PFS of 14.7 months. One-year intracranial-progression-free rate was 58.5%, and two-year rate was 22.2%. Univariate survival analysis showed that patients with lower CEA level at initial diagnosis (3)(15 months vs 12.6 months, P=0.041) were prone to have a superior intracranial PFS. Multivariate analysis showed that CEA≥10 ng/mL and intracranial lesion≥2 cm were the independent risk factors of intracranial PFS.@*CONCLUSIONS@#EGFR-TKIs in combination with gamma knife radiosurgery was an efficient treatment option to control the cranial tumor lesion. CEA≥10 μg/L at initial diagnosis and intracranial lesion≥2 cm were the risk factors of EGFR-mutant brain-metastatic lung adenocarcinoma patients receiving EGFR-TKIs in combination with gamma knife radiosurgery.

Repeat Stereotactic Radiosurgery for Recurred Metastatic Brain Tumors

OBJECTIVE: We investigated the outcomes of repeat stereotactic radiosurgery (SRS) for metastatic brain tumors that locally recurred despite previous SRS, focusing on the tumor control. METHODS: A total of 114 patients with 176 locally recurring metastatic brain tumors underwent repeat SRS after previous SRS. The mean age was 59.4 years (range, 33 to 85), and there were 68 male and 46 female patients. The primary cancer types were non-small cell lung cancer (n=67), small cell lung cancer (n=12), gastrointestinal tract cancer (n=15), breast cancer (n=10), and others (n=10). The number of patients with a single recurring metastasis was 95 (79.8%), and another 19 had multiple recurrences. At the time of the repeat SRS, the mean volume of the locally recurring tumors was 5.94 mL (range, 0.42 to 29.94). We prescribed a mean margin dose of 17.04 Gy (range, 12 to 24) to the isodose line at the tumor border primarily using a 50% isodose line. RESULTS: After the repeat SRS, we obtained clinical and magnetic resonance imaging follow-up data for 84 patients (73.7%) with a total of 108 tumors. The tumor control rate was 53.5% (58 of the 108), and the median and mean progression-free survival (PFS) periods were 246 and 383 days, respectively. The prognostic factors that were significantly related to better tumor control were prescription radiation dose of 16 Gy (p=0.000) and tumor volume less than both 4 mL (p=0.001) and 10 mL at the repeat SRS (p=0.008). The overall survival (OS) periods for all 114 patients after repeat SRS varied from 1 to 56 months, and median and mean OS periods were 229 and 404 days after the repeat SRS, respectively. The main cause of death was systemic problems including pulmonary dysfunction (n=58, 51%), and the identified direct or suspected brain-related death rate was around 20%. CONCLUSION: The tumor control following repeat SRS for locally recurring metastatic brain tumors after a previous SRS is relatively lower than that for primary SRS. However, both low tumor volume and high prescription radiation dose were significantly related to the tumor control following repeat SRS for these tumors after previous SRS, which is a general understanding of primary SRS for metastatic brain tumors.

Efficacy of Gamma Knife Radiosurgery for Recurrent High-Grade Gliomas with Limited Tumor Volume

OBJECTIVE: This study aims to determine whether gamma knife radiosurgery (GKR) improves survival in patients with recurrent highgrade gliomas. METHODS: Twenty nine patients with recurrent high-grade glioma underwent 38 GKR. The male-to-female ratio was 10 : 19, and the median age was 53.8 years (range, 20–75). GKR was performed in 11 cases of recurrent anaplastic oligodendrogliomas, five anaplastic astrocytomas, and 22 glioblastomas. The median prescription dose was 16 Gy (range, 10–24), and the median target volume was 7.0 mL (range, 1.1–15.7). Of the 29 patients, 13 (44.8%) received concurrent chemotherapy. We retrospectively analyzed the progression-free survival (PFS) and overall survival (OS) after GKR depending on the Eastern Cooperative Oncology Group (ECOG) performance status (PS), pathology, concurrent chemotherapy, radiation dose, and target tumor volume. RESULTS: Starting from when the patients underwent GKR, the median PFS and OS were 5.0 months (range, 1.1–28.1) and 13.0 months (range, 1.1–75.1), respectively. On univariate analysis, the median PFS was significantly long in patients with anaplastic oligodendroglioma, ECOG PS 1, and target tumor volume less than 10 mL (p < 0.05). Meanwhile, on multivariate analysis, patients with ECOG PS 1 and target tumor volume less than 10 mL showed improved PFS (p=0.043 and p=0.007, respectively). The median OS was significantly increased in patients with ECOG PS 1 and tumor volume less than 10 mL on univariate and multivariate analyses (p < 0.05). CONCLUSION: GKR could be an additional treatment option in recurrent high-grade glioma, particularly in patients with good PS and limited tumor volume.

Gamma Knife Radiosurgery for Cancer Metastasized to the Ocular Choroid

OBJECTIVE: Choroidal metastases (CMs) are the most common intraocular tumor. Management is mainly radiation therapy with goals of pain control and visual improvement. However, many radiation-related complications are reported. Since gamma knife radiosurgery (GKS) for CM was first reported in 1995, few cases have been reported. We report 7 cases of CMs treated with GKS. METHODS: From April 2011 to November 2014, 7 patients with CM underwent GKS. Their median age at treatment was 64 years (range, 51–71 years). Four males and three females were treated. Lung cancer was the most common primary pathology, followed by renal cell carcinoma and stomach cancer. Four patients had multiple cerebral lesions and were treated simultaneously for choroidal lesions. The median marginal dose of 20 Gy (range, 15–25 Gy) was administered at the 50% isodose line. RESULTS: Median follow-up period after GKS was 8 months (range, 2–38.3 months). Four patients expired due to underlying malignancy progression. Except for two patients who were not followed with magnetic resonance image after GKS, all patients showed size reduction in the treated lesions, but a new choroidal lesion appeared in one patient and one recurred. Six of seven patients reported subjectively improved visual symptoms. Visual acuity improved in 2 patients, and 2 were stable upon objective examination. One patient showed no improvement in visual acuity, but ocular pain was relieved; another patient showed improved vision and tumor remission, but visual deterioration recurred. CONCLUSION: GKS was shown to be safe and effective and should be considered for CM treatment.

Efficacy of Gamma Knife Radiosurgery for Recurrent High-Grade Gliomas with Limited Tumor Volume

OBJECTIVE: This study aims to determine whether gamma knife radiosurgery (GKR) improves survival in patients with recurrent highgrade gliomas.METHODS: Twenty nine patients with recurrent high-grade glioma underwent 38 GKR. The male-to-female ratio was 10 : 19, and the median age was 53.8 years (range, 20–75). GKR was performed in 11 cases of recurrent anaplastic oligodendrogliomas, five anaplastic astrocytomas, and 22 glioblastomas. The median prescription dose was 16 Gy (range, 10–24), and the median target volume was 7.0 mL (range, 1.1–15.7). Of the 29 patients, 13 (44.8%) received concurrent chemotherapy. We retrospectively analyzed the progression-free survival (PFS) and overall survival (OS) after GKR depending on the Eastern Cooperative Oncology Group (ECOG) performance status (PS), pathology, concurrent chemotherapy, radiation dose, and target tumor volume.RESULTS: Starting from when the patients underwent GKR, the median PFS and OS were 5.0 months (range, 1.1–28.1) and 13.0 months (range, 1.1–75.1), respectively. On univariate analysis, the median PFS was significantly long in patients with anaplastic oligodendroglioma, ECOG PS 1, and target tumor volume less than 10 mL (p < 0.05). Meanwhile, on multivariate analysis, patients with ECOG PS 1 and target tumor volume less than 10 mL showed improved PFS (p=0.043 and p=0.007, respectively). The median OS was significantly increased in patients with ECOG PS 1 and tumor volume less than 10 mL on univariate and multivariate analyses (p < 0.05).CONCLUSION: GKR could be an additional treatment option in recurrent high-grade glioma, particularly in patients with good PS and limited tumor volume.

Gamma Knife Radiosurgery for Cancer Metastasized to the Ocular Choroid

OBJECTIVE: Choroidal metastases (CMs) are the most common intraocular tumor. Management is mainly radiation therapy with goals of pain control and visual improvement. However, many radiation-related complications are reported. Since gamma knife radiosurgery (GKS) for CM was first reported in 1995, few cases have been reported. We report 7 cases of CMs treated with GKS.METHODS: From April 2011 to November 2014, 7 patients with CM underwent GKS. Their median age at treatment was 64 years (range, 51–71 years). Four males and three females were treated. Lung cancer was the most common primary pathology, followed by renal cell carcinoma and stomach cancer. Four patients had multiple cerebral lesions and were treated simultaneously for choroidal lesions. The median marginal dose of 20 Gy (range, 15–25 Gy) was administered at the 50% isodose line.RESULTS: Median follow-up period after GKS was 8 months (range, 2–38.3 months). Four patients expired due to underlying malignancy progression. Except for two patients who were not followed with magnetic resonance image after GKS, all patients showed size reduction in the treated lesions, but a new choroidal lesion appeared in one patient and one recurred. Six of seven patients reported subjectively improved visual symptoms. Visual acuity improved in 2 patients, and 2 were stable upon objective examination. One patient showed no improvement in visual acuity, but ocular pain was relieved; another patient showed improved vision and tumor remission, but visual deterioration recurred.CONCLUSION: GKS was shown to be safe and effective and should be considered for CM treatment.

Repeat Stereotactic Radiosurgery for Recurred Metastatic Brain Tumors

OBJECTIVE: We investigated the outcomes of repeat stereotactic radiosurgery (SRS) for metastatic brain tumors that locally recurred despite previous SRS, focusing on the tumor control.METHODS: A total of 114 patients with 176 locally recurring metastatic brain tumors underwent repeat SRS after previous SRS. The mean age was 59.4 years (range, 33 to 85), and there were 68 male and 46 female patients. The primary cancer types were non-small cell lung cancer (n=67), small cell lung cancer (n=12), gastrointestinal tract cancer (n=15), breast cancer (n=10), and others (n=10). The number of patients with a single recurring metastasis was 95 (79.8%), and another 19 had multiple recurrences. At the time of the repeat SRS, the mean volume of the locally recurring tumors was 5.94 mL (range, 0.42 to 29.94). We prescribed a mean margin dose of 17.04 Gy (range, 12 to 24) to the isodose line at the tumor border primarily using a 50% isodose line.RESULTS: After the repeat SRS, we obtained clinical and magnetic resonance imaging follow-up data for 84 patients (73.7%) with a total of 108 tumors. The tumor control rate was 53.5% (58 of the 108), and the median and mean progression-free survival (PFS) periods were 246 and 383 days, respectively. The prognostic factors that were significantly related to better tumor control were prescription radiation dose of 16 Gy (p=0.000) and tumor volume less than both 4 mL (p=0.001) and 10 mL at the repeat SRS (p=0.008). The overall survival (OS) periods for all 114 patients after repeat SRS varied from 1 to 56 months, and median and mean OS periods were 229 and 404 days after the repeat SRS, respectively. The main cause of death was systemic problems including pulmonary dysfunction (n=58, 51%), and the identified direct or suspected brain-related death rate was around 20%.CONCLUSION: The tumor control following repeat SRS for locally recurring metastatic brain tumors after a previous SRS is relatively lower than that for primary SRS. However, both low tumor volume and high prescription radiation dose were significantly related to the tumor control following repeat SRS for these tumors after previous SRS, which is a general understanding of primary SRS for metastatic brain tumors.

Effect analysis of Gamma knife radiosurgery for cavernous sinus cavernous hemangioma / 中国脑血管病杂志

ObjectIve To evaluate the safety and efficacy of Gamma knife radiosurgery for the treatment of cavernous sinus cavernous hemangioma. Methods From June 2010 to July 2016, 35 consecutive patients with cavernous sinus cavernous hemangioma treated with Gamma knife radiosurgery at the Department of Neurosurgery,West China Hospital,Sichuan University were enrolled retrospective, including 22 females and 13 males. All patients were diagnosed by MRI before procedure. They were confirmed by postoperative histopathology or further verification by MRI. The irradiation dose of Gamma knife around tumors were 11-16 Gy (mean 14. 3 ± 1. 1 Gy),covered by 45%-50% isodose line and ensured that the exposure dose of the optic cross was less than 8 Gy. In the first year after operation,they were followed up at 3,6,9,and 12 months,and after that,the clinical efficacy,surgical complications and tumor volume were evaluated once a year. Results Thirty-five patients were followed up for 12-77 months (mean 36 ± 4 months). No surgery-related optic nerve injury and new cranial nerve injury occurred in all cases . Symptomatic patients were 28 (80%)and symptomatic improvement rate was 96. 4%(n＝27),among them,the symptoms were improved in 15 cases (53. 6%),and the symptoms disappeared in 12 cases (42. 9%),did not have any change in 1 (3. 6%)case,and no symptom deterioration occurred. The symptom improvement time was 2-7 months after surgery (mean 3. 7 ± 0. 3 months). Imaging follow-up revealed that in 35 patients with cavernous sinus cavernous hemangioma treated by gamma knife radiosurgery,the tumor volume was significantly reduced after treatment compared with that before treatment,and the difference wasstatisticallysignificant(8.8±0.9cm3vs.32.6±3.6cm3,t＝8.492,P＜0.01).Theratesoftumor volume change were ≤25%,26%-50%,51%-75%,and ≥75%. There were 3 patients (8. 6%), 2 (5. 7%),8 (22. 9%),and 22 (62. 9%),respectively. Conclusions Gamma knife radiosurgery is safe and effective in the treatment of cavernous sinus cavernous hemangioma. It can be used as the preferred treatment modality for this disease,but long-term follow-up is needed to observe its long-term efficacy.

Fractionated Gamma Knife Radiosurgery as Initial Treatment for Large Skull Base Meningioma

We present our experience on the hypofractionated Gamma Knife radiosurgery (FGKS) for large skull base meningioma as an initial treatment. We retrospectively reviewed 23 patients with large skull base meningioma ≥10 cm³ who underwent FGKS as the initial treatment option. The mean volume of tumors prior to radiosurgery was 21.2±15.63 cm³ (range, 10.09~71.42). The median total margin dose and marginal dose per fraction were 18 Gy (range, 15~20) and 6 Gy (range, 5~6), respectively. Patients underwent three or four fractionations in consecutive days with the same Leksell® frame. The mean follow-up duration was 38 months (range, 17~78). There was no mortality. At the last follow-up, the tumor volume was stationary in 15 patients (65.2%) and had decreased in 8 patients (34.8%). Six patients who had cranial neuropathy at the time of FGKS showed improvement at the last clinical follow-up. Following FGKS, 4 patients (17%) had new cranial neuropathy. The trigeminal neuropathy was the most common and all were transient. The mean Karnofsky Performance Status score at pre-FGKS and the last clinical follow-up was 97.0±10.4 points (median, 100) and 98.6±6.9 (median, 100) points, respectively. FGKS has showed satisfactory tumor control with functional preservation for large skull base meningiomas. Further prospective studies of large cohorts with long term follow-up are required to clarify the efficacy in the tumor control and functional outcome as well as radiation toxicity.

Pituitary Epithelioid Osteosarcoma after Gamma-knife Surgery of a Pituitary Adenoma / 대한내과학회지

With the increasing use of stereotactic radiosurgery, recent reports have suggested that stereotactic radiosurgery may induce secondary malignancies. While the risk of secondary malignancy after conventional radiotherapy is well known, its development after stereotactic radiosurgery has been reported in only a few cases. Here we present the case of a 56-year-old female with visual disturbance of sudden onset. She underwent trans-sphenoidal surgery for a pituitary adenoma 13 years earlier. Imaging studies revealed a newly developed pituitary mass invading the right carvenous sinus. Gross total resection of the tumor was performed using a trans-sphenoidal and pterygopalatine fossa approach. The histological diagnosis was pituitary epithelioid osteosarcoma. Clinicians should be aware of the rare occurrence of radiation-induced pituitary sarcoma as a potentially fatal late complication of stereotactic radiosurgery.

The Influence of Biomarker Mutations and Systemic Treatment on Cerebral Metastases from NSCLC Treated with Radiosurgery

OBJECTIVE: The purpose of this study was to analyze outcomes and identify prognostic factors in patients with cerebral metastases from non-small cell lung cancer (NSCLC) treated with gamma knife radiosurgery (GKS) particularly, focusing on associations of biomarkers and systemic treatments. METHODS: We retrospectively reviewed the medical records of 134 patients who underwent GKS for brain metastases due to NSCLC between January 2002 and December 2012. Representative biomarkers including epidermal growth factor receptor (EGFR) mutation, K-ras mutation, and anaplastic lymphoma kinase (ALK) mutation status were investigated. RESULTS: The median overall survival after GKS was 22.0 months (95% confidence interval [CI], 8.8–35.1 months). During follow-up, 63 patients underwent salvage treatment after GKS. The median salvage treatment-free survival was 7.9 months (95% CI, 5.2–10.6 months). Multivariate analysis revealed that lower recursive partition analysis (RPA) class, small number of brain lesions, EGFR mutation (+), and ALK mutation (+) were independent positive prognostic factors associated with longer overall survival. Patients who received target agents 30 days after GKS experienced significant improvements in overall survival and salvage treatment-free survival than patients who never received target agents and patients who received target agents before GKS or within 30 days (median overall survival: 5.0 months vs. 18.2 months, and 48.0 months with p-value=0.026; median salvage treatment-free survival: 4.3 months vs. 6.1 months and 16.6 months with p-value=0.006, respectively). To assess the influence of target agents on the pattern of progression, cases that showed local recurrence and new lesion formation were analyzed according to target agents, but no significant effects were identified. CONCLUSION: The prognosis of patients with brain metastases of NSCLC after GKS significantly differed according to specific biomarkers (EGFR and ALK mutations). Our results show that target agents combined with GKS was related to significantly longer overall survival, and salvage treatment-free survival. However, target agents were not specifically associated with improved local control of the lesion treated by GKS either development of new lesions. Therefore, it seems that currently popular target agents do not affect brain lesions themselves, and can prolong survival by controlling systemic disease status.

Resection and Observation for Brain Metastasis without Prompt Postoperative Radiation Therapy

OBJECTIVE: Total resection without consecutive postoperative whole brain radiation therapy is indicated for patients with a single or two sites of brain metastasis, with close follow-up by serial magnetic resonance imaging (MRI). In this study, we explored the effectiveness, usefulness, and safety of this follow-up regimen. METHODS: From January 2006 to December 2015, a total of 109 patients (76 males, 33 females) underwent tumor resection as the first treatment for brain metastases (97 patients with single metastases, 12 with two metastases). The mean age was 59.8 years (range 27–80). The location of the 121 tumors in the 109 patients was supratentorial (n=98) and in the cerebellum (n=23). The origin of the primary cancers was lung (n=45), breast (n=17), gastrointestinal tract (n=18), hepatobiliary system (n=8), kidney (n=7), others (n=11), and unknown origin (n=3). The 121 tumors were totally resected. Follow-up involved regular clinical and MRI assessments. Recurrence-free survival (RFS) and overall survival (OS) after tumor resection were analyzed by Kaplan-Meier methods based on clinical prognostic factors. RESULTS: During the follow-up, MRI scans were done for 85 patients (78%) with 97 tumors. Fifty-six of the 97 tumors showed no recurrence without adjuvant local treatment, representing a numerical tumor recurrence-free rate of 57.7%. Mean and median RFS was 13.6 and 5.3 months, respectively. Kaplan-Meier analysis revealed the cerebellar location of the tumor as the only statistically significant prognostic factor related to RFS (p=0.020). Mean and median OS was 15.2 and 8.1 months, respectively. There were no significant prognostic factors related to OS. The survival rate at one year was 8.2% (9 of 109). CONCLUSION: With close and regular clinical and image follow-up, initial postoperative observation without prompt postoperative radiation therapy can be applied in patients of brain metastasi(e)s when both the tumor(s) are completely resected.

Systematic Analysis of Clinical Outcomes Following Stereotactic Radiosurgery for Central Neurocytoma

Central neurocytoma (CN) typically presents as an intraventricular mass causing obstructive hydrocephalus. The first line of treatment is surgical resection with adjuvant conventional radiotherapy. Stereotactic radiosurgery (SRS) was proposed as an alternative therapy for CN because of its lower risk profile. The objective of this systematic analysis is to assess the efficacy of SRS for CN. A systematic analysis for CN treated with SRS was conducted in PubMed. Baseline patient characteristics and outcomes data were extracted. Heterogeneity and publication bias were also assessed. Univariate and multivariate linear regressions were used to test for correlations to the primary outcome: local control (LC). The estimated cumulative rate of LC was 92.2% (95% confidence interval: 86.5-95.7%, p<0.001). Mean follow-up time was 62.4 months (range 3-149 months). Heterogeneity and publication bias were insignificant. The univariate linear regression models for both mean tumor volume and mean dose were significantly correlated with improved LC (p<0.001). Our data suggests that SRS may be an effective and safe therapy for CN. However, the rarity of CN still limits the efficacy of a quantitative analysis. Future multi-institutional, randomized trials of CN patients should be considered to further elucidate this therapy.

Clinical Outcomes of Gamma Knife Radiosurgery for Metastatic Brain Tumors from Gynecologic Cancer : Prognostic Factors in Local Treatment Failure and Survival

OBJECTIVE: Brain metastases in gynecologic cancer (ovarian, endometrial, and cervical cancer) patients are rare, and the efficacy of Gamma Knife Radiosurgery (GKRS) to treat these had not been evaluated. We assessed the efficacy of GKRS and prognostic factors for tumor control and survival in brain metastasis from gynecologic cancers. METHODS: This retrospective study was approved by the institutional review board. From May 1995 to October 2012, 26 women (mean age 51.3 years, range 27-70 years) with metastatic brain tumors from gynecologic cancer were treated with GKRS. We reviewed their outcomes, radiological responses, and clinical status. RESULTS: In total 24 patients (59 lesions) were available for follow-up imaging. The median follow-up time was 9 months. The mean treated tumor volume at the time of GKRS was 8185 mm³ (range 10-19500 mm³), and the median dose delivered to the tumor margin was 25 Gy (range, 10-30 Gy). A local tumor control rate was 89.8% (53 of 59 tumors). The median overall survival was 9.5 months after GKRS (range, 1-102 months). Age-associated multivariate analysis indicated that the Karnofsky performance status (KPS), the recursive partitioning analysis (RPA) classification, and the number of treated lesions were significant prognostic factors for overall survival (HR=0.162, p=0.008, HR=0.107, p=0.038, and HR=2.897, p=0.045, respectively). CONCLUSION: GKRS is safe and effective for the management of brain metastasis from gynecologic cancers. The clinical status of the patient is important in determining the overall survival time.

A Case of Cochlear Implantation in Neurofibromatosis Type II / 대한이비인후과학회지

Patients with neurofibromatosis type 2 (NF2) develop bilateral vestibular schwannomas that can cause binaural progressive hearing loss in most individuals. Auditory rehabilitation for bilateral profound sensorineural hearing loss in patients with NF2 poses a great therapeutic challenge. An auditory brainstem implantation may be an option after tumor excision, but its hearing results are still relatively unsatisfactory. A cochlear implantation (CI) may be another option in those cases where the cochlear nerve has been left intact after tumor excision or in those cases that have been kept stable after treating with Gamma-Knife. Here we report a case of undergoing CI after having been treated with Gamma-Knife in NF2 and showing improved open-set speech perception.