Successful surgical treatment of oculomotor palsy due to schwannoma of the cavernous sinus in a 7-year-old girl: a case report

Oculomotor nerve schwannoma in children not associated with neurofibromatosis is a rare disease, with 26 pediatric cases reported so far. There is no established treatment plan. A 7-year-old girl presented with oculomotor nerve palsy. Surgical reduction of the tumor combined with postoperative gamma knife surgery preserved the oculomotor nerve, improved oculomotor nerve function, and achieved tumor control during the observation period of 20 months. The combination of partial surgical resection and gamma knife surgery as a treatment strategy for oculomotor nerve schwannoma resulted in a good outcome.

Natural History and Histopathology of Expanding Cysts and Hematomas After Stereotactic Radiosurgery for Arteriovenous Malformations of the Brain: A Case Series

BACKGROUND

We reviewed the clinical course and histopathologic findings for cases involving the formation of expanding cysts and/or hematomas after gamma knife surgery (GKS) for arteriovenous malformations (AVMs).

METHODS

We report a single-center retrospective review of 18 patients who presented with cyst and/or hematoma expansion after GKS for AVMs between 1993 and 2023. Expanding cysts and hematomas were defined as well-demarcated cavities filled with fluid or well-marginated heterogenous hematomas presenting with expansion proximal to or in the location of the original AVM, respectively. Patient demographics, AVM characteristics, history of interventions and surgeries, and imaging and histopathologic features of expanding cysts and hematomas were collected for analysis.

RESULTS

Among 1072 AVM patients treated using GKS, 18 presented with expanding cysts or hematomas during a total follow-up period of 16,757 patient-years (0.11 case/100 persons/patient-year). The time to cyst or hematoma identification was 4-13 years after initial GKS, with a mean duration of 8.6 years. Among the patients examined, 7 (38.9%) presented mainly with hematoma, 10 (55.6%) presented mainly with cysts, and 1 presented with approximately equal components of both. Among the 18 patients, 13 (72.2%) underwent craniotomy to treat cyst or hematoma expansion. All the specimens had similar histopathologic characteristics, including organizing hematoma with fresh and old hemorrhage, fibrinoid necrosis of the vessels, gliosis of normal brain tissue, infiltration of hemosiderin-laden histiocytes, and extravascular protein leakage.

CONCLUSIONS

Our findings suggest that the formation of these 2 complications can be attributed to a common mechanism involving radiation-induced vascular damage in brain tissue adjacent to the AVM and subsequent chronic inflammation and capillary dilatation.

Gamma Knife surgery and deep brain stimulation of the centromedian nucleus for chronic pain: A systematic review

Chronic pain has been a major problem in personal quality of life and social economy, causing psychological disorders in people and a larger amount of money loss in society. Some targets were adopted for chronic pain, but the efficacy of the CM nucleus for pain was still unclear. A systematic review was performed to summarize GK surgery and DBS of the CM nucleus for chronic pain. PubMed, Embase and Medline were searched to review all studies discussing GK surgery and DBS on the CM nucleus for chronic pain. Studies that were review, meet, conference, not English or not the therapy of pain were excluded. Demographic characteristics, surgery parameters and outcomes of pain relief were selected. In total, 101 patients across 12 studies were included. The median age of most patients ranged from 44.3 to 80 years when the duration of pain ranged from 5 months to 8 years. This review showed varied results of 30%-100% pain reduction across studies. The difference in the effect between GK surgery and DBS cannot be judged. Moreover, three retrospective articles related to GK surgery of the CM nucleus for trigeminal neuralgia presented an average pain relief rate of 34.6-82.5%. Four studies reported adverse effects in a small number of patients. GK surgery and DBS of the CM nucleus might be promising therapeutic approaches for chronic refractory pain. More rigorous studies and larger samples with longer follow-up periods are needed to support the effectiveness and safety.

Effects of two different radiotherapies for craniopharyngiomas using stereotactic radiosurgery/ stereotactic radiotherapy or fractionated stereotactic radiotherapy

Background

Numerous studies have reported about good tumor control with both stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for residual and recurrent craniopharyngiomas, but no studies have reported on the appropriate use of different types of radiation modalities. This study aimed to report the outcomes of SRS/stereotactic radiotherapy (SRT) or FSRT and compare tumor control in a single center.

Methods

From 2014 when TrueBeamTM STx with Novalis was introduced in our hospital to 2021, 21 patients underwent SRS/SRT or FSRT with gamma knife surgery (GKS) and Novalis. We have selected the radiation modalities considering mainly the distance of the optic nerve and chiasm. Imaging and clinical follow-up data were sent and reviewed.

Results

The mean age was 52 years and there were 11 men. Of the 21 total patients, three experienced SRS (GKS, 50% isodose 12-15 Gy), five underwent SRT (GKS or Novalis, 19.5-24 Gy 3 fractions), and 13 patients underwent FSRT (Novalis, 54 Gy 30 fractions). The median follow-up was 32.6 (range 17-44) months after SRS/SRT and 34.0 (range 4-61) months after FSRT. In the SRS/SRT group, the mean tumor volume decreased from 1.103 to 0.131 cm³ (P < 0.01), and in the FSRT group, from 3.015 to 1.012 cm³ (P < 0.01). No radiation-induced optic neuropathy and other acute toxicity occurred.

Conclusion

Craniopharyngioma can be expected to have very good tumor control by selecting SRS/SRT or FSRT depending on the distance between the optic nerve and the tumor.

Microvascular Decompression Versus Gamma Knife Surgery in Patients with Drug-Resistant Trigeminal Neuralgia: A Systematic Review and Meta-Analysis

OBJECTIVE

There are 2 cardinal approaches for drug-resistant trigeminal neuralgia (TN), including microvascular decompression (MVD) and gamma knife surgery (GKS). This study aimed to compare the results of MVD versus GKS in the treatment of drug-resistant TN.

METHODS

The search strategy was formulated in accordance with PRISMA recommendations for publications retrieved from electronic databases, such as PubMed, Scopus, and web of science. Inclusion and exclusion criteria were examined for relevant research. The meta-analysis was conducted by combining data using odds ratios.

RESULTS

Four papers were included in our study. 582 patients were treated with MVD, and 607 patients were treated with GKS for drug-resistant TN. Findings revealed that MVD related to higher rates of pain relief and lower rates of pain recurrence compared to GKS. It seems that GKS had lower post-procedural complications in our review.

CONCLUSIONS

MVD and GKS both reduce pain in patients with drug-resistant TN, but MVD was superior to GKS in pain relief. Furthermore, recurrence rate was lower. Post-operative complications except facial numbness were higher in MVD.

The prognosis and treatment effectiveness of de novo aneurysm formation after radiation therapy for brain tumor

Radiation therapy is a well-established, minimally invasive method of treating brain tumors. In recent years, the number of post-radiotherapy patients has increased, and delayed side effects are evident. De novo aneurysm formation after radiation often manifests as fatal subarachnoid hemorrhage (SAH), resulting in severe clinical outcomes. Nevertheless, the prognosis and therapeutic efficacy of radiation-induced aneurysms (RIAs) remain unclear. Using the PubMed database from 1980 to 2021, we screened 45 articles (53 individual cases) on RIAs; approximately 70% of RIAs were diagnosed after rupture. Of 38 ruptured RIAs, 12 (31.6%) had modified Rankin scale (mRS) 5-6. On the other hand, all unruptured RIAs (15 cases) recovered without neurological deficits (p = 0.012). Ten of the 39 ruptured RIAs were treated surgically, and 22 were treated endovascularly. There was no significant difference in mRS between treatment modalities (p = 0.393), but conservative therapy was significantly related to unfavorable outcomes (p = 0.025). To improve clinical outcomes, RIAs need to be diagnosed before rupture. Surgeons should be aware of de novo aneurysm formation in patients long after radiation therapy.

Cavernous malformations

Cavernous malformations are relatively common intracerebral malformations of which we only became properly aware after the introduction of MRI. They may be sporadic or familial. Familial CMs may be multiple and new lesions appear over time requiring intermittent MR control. Many sporadic CMs have no symptoms. The commonest location is in the supratentorial cerebral parenchyma presenting with epilepsy. The best treatment is microsurgery. A small proportion are in the brainstem and may rebleed and even be lethal. Treatment includes microsurgery and radiosurgery. Microsurgery cures the patient but has substantial problems with complications, deterioration and partial removal. Radiosurgery has taken time to demonstrate that it can over 2 years substantially reduce the risk of rebleeds without the risks of microsurgery. Both methods have a part to play in the treatment.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Stereotactic radiosurgery in alveolar soft part sarcoma brain metastases: Case series and literature review

Alveolar soft part sarcoma (ASPS) has the highest incidence of brain metastasis amongst sarcomas. There is a paucity of literature published focusing on radiation therapy for this condition. This is a single centre retrospective review of the treatment of three patients with 12 ASPS brain metastasis using single dose stereotactic radiosurgery (SRS). Five lesions were treated with low (<25 Gy) and seven with high (≥25 Gy) dose. Four lesions had a volume of >1.5 cm³ and were defined as large, while seven had a volume of ≤0.5 cm³ and were defined as small. The local tumor control as well as the clinical complication rates were studied. There was a statistically significant relation between treatment dose and tumor control rate. All large tumors treated with low dose recurred and required surgical removal within two months following SRS, while the large lesion treated with high dose recurred after 11 months. Five of the six small tumors treated with high doses were controlled, while the sixth required retreatment and was stable thereafter. No patient suffered from undue symptomatic radiation effects. The success rate following SRS for small ASPS metastases treated with high doses seems to be sufficient to justify the treatment. The short time for large tumor to recur, significant increase in tumor size requiring surgical removal of the tumors, makes low dose SRS unattractive. Based on this limited patient population, it seems that high dose SRS should be used for all ASPS brain metastases except for large tumors deemed surgically accessible.

Clinicopathological differences in radiation-induced organizing hematomas of the brain based on type of radiation treatment and primary lesions

Background

Radiation-induced organizing hematoma (RIOH) is a sporadic form of cavernous hemangioma (CH) that occurs after cerebral radiation. RIOH lesions are distinct histologically from de novo CH; however, detailed research on this subject is lacking. In the present study, the clinical and histological features of RIOHs were evaluated based on causative lesions.

Methods

The present study included 37 RIOHs confirmed by surgical excision from January 2009, to May 2020, in Yonsei Severance Hospital. All cases were divided into subgroups based on type of radiation treatment (gamma knife surgery [GKS], n = 24 vs. conventional radiation therapy [RT], n = 13) and pathology of the original lesion (arteriovenous malformation, n = 14; glioma, n = 12; metastasis, n = 4; other tumors, n = 7). The clinicopathological results were compared between the groups.

Results

Clinical data of multiplicity, latency, and size and wall thickness of the original tumors and RIOHs were analyzed. The GKS group showed shorter latency (5.85 ± 4.06 years vs. 11.15 ± 8.27 years, p = .046) and thicker tumor wall (693.7 ± 565.7 μm vs. 406.9 ± 519.7 μm, p = .049) than the conventional RT group. Significant difference was not found based on original pathology.

Conclusion

RIOH is more likely to occur earlier with thick tumor wall in subjects who underwent GKS than in patients who underwent conventional RT. These results indicate the clinical course of RIOH differs based on type of treatment and might help determine the duration of follow-up.

Clinical Features and Treatment Outcomes of Cerebral Arteriovenous Malformation Associated With Moyamoya Disease

BACKGROUND

Cerebral arteriovenous malformation (AVM) can rarely occur in conjunction with moyamoya disease (MMD). There is still no consensus on how to treat AVM when accompanied by MMD. In this study, we assessed the clinical features and suggested appropriate management when AVM was combined with MMD.

METHODS

From August 1994 to December 2020, 7 out of 4004 patients with MMD were found to have AVM. The Karnofsky Performance Scale (KPS) was used to evaluate the clinical outcomes of AVM and MMD. KPS greater than 80 was classified as a good outcome. In addition, the radiologic outcomes of the patients were evaluated.

RESULTS

The incidence of AVM with MMD was 1.7 per 1000 persons. Five patients underwent bypass surgery for MMD, and 5 patients underwent Gamma Knife surgery (GKS) for concurrent AVM. Postoperative perfusion magnetic resonance imaging and brain single photon emission computerized tomography showed improved cerebral hemodynamics in 4 out of 7 territories. Postoperative cerebral angiography showed good revascularization in 4 out of 8 territories. After GKS, 4 patients showed complete obliteration, and 1 patient showed a significantly decreased AVM size. Six patients showed favorable clinical outcomes (KPS 80-100), and 1 patient with delayed GKS for AVM had a poor outcome (KPS 20) due to AVM rupture.

CONCLUSIONS

In this study, AVM tended to occur where the angiographic stage of MMD was higher. When AVM is combined with MMD, MMD bypass surgery is recommended based on symptoms and cerebral perfusion status. For AVM, less invasive but effective treatments, such as GKS, should be implemented as soon as possible.

Useful hearing preservation is improved in vestibular schwannoma patients who undergo stereotactic radiosurgery before further hearing deterioration ensues

INTRODUCTION

The present study evaluates whether hearing deterioration during observation reduces serviceable hearing preservation rates after stereotactic radiosurgery (SRS) in vestibular schwannoma (VS) patients with useful hearing.

METHODS

We retrospectively analyzed 1447 VS patients who underwent SRS between 1992 and 2017. We identified 100 VS patients who had Grade I Gardner- Robertson (GR) hearing at initial diagnosis but were observed without surgery or SRS. We compared hearing after SRS in 67 patients who retained GR Grade I hearing from initial diagnosis to SRS (the hearing maintenance or HM group) to 33 patients whose hearing worsened from GR grade I to grade II (the hearing deterioration or HD group). We also investigated whether a decline in pure tone average (PTA) or speech discrimination score (SDS) before SRS affected hearing preservation after SRS.

RESULTS

The serviceable hearing (GR I and II) preservation in HM patients was 80%s, 63%, and 51% at 3, 5, and 10 years, respectively. The serviceable hearing preservation in HD patients was 40%, 33%, and 20% at 3, 5, and 10 years, respectively. In multivariate analysis, younger age (< 55 years, p = 0.045) and HM during observation (p = 0.001) improved serviceable hearing preservation rates. Patients whose PTA increased ≥ 15 dB (p = 0.024) or whose SDS declined ≥ 10% (p = 0.019) had reduced serviceable hearing preservation rates.

CONCLUSIONS

Hearing deterioration during observation before SRS reduced long term hearing preservation rate in VS patients with GR grade I hearing at initial diagnosis. SRS before hearing deterioration was recommended for hearing preservation.

Stereotactic gamma knife radiosurgery for orbital cavernous hemangioma: clinical outcome and visual function protection

PURPOSE

Although rare, orbital cavernous hemangioma (OCH) is the most common benign orbital neoplasm in adults and may cause vision disturbance or loss due to optic nerve compression. The conventional treatment is surgical excision, which carries a risk of intraoperative nerve damage, whereas gamma knife radiosurgery (GKRS) can be a safe and effective alternative. Herein, we report the results of four patients with OCH treated with GKRS, and describe the method of treatment including the optic nerve protection.

METHODS

This retrospective study included four consecutive patients (three women, one man; mean age: 50 ± 14.7 years) with OCH treated with single-session GKRS between 2014 and 2020. Three patients had decreased visual acuity. During GKRS, the prescription dose delivered to the tumor margin was 12 Gy at the 55-58% isodose line. The dose to the optic nerve margin was < 12 Gy. Follow-up included sequential magnetic resonance imaging (MRI) and ophthalmological examinations at 6-month intervals.

RESULTS

The median follow-up period was 29.5 ± 23 months (range, 12-63 months). After GKRS, three patients with visual dysfunction had substantial vision improvement; the fourth patient continued to have normal vision without deterioration. Radiological outcomes after GKRS indicated an average tumor shrinkage of 70% ± 10.6% at the 6-month follow-up and 83% ± 2.64% at the 1-year follow-up. No adverse radiation effects were observed.

CONCLUSIONS

GKRS for OCH achieved favorable clinical outcomes, with substantial tumor volume reduction. OCH can be diagnosed based on characteristic MRI findings. GKRS may be considered a treatment option for OCH in selected cases.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Trigeminal Neuralgia Secondary to Meningiomas and Vestibular Schwannoma Is Improved after Stereotactic Radiosurgery: A Systematic Review and Meta-Analysis

INTRODUCTION

Trigeminal neuralgia (TN) secondary to tumors is encountered in up to 6% of patients with facial pain syndromes and is considered to be associated with tumors affecting the trigeminal nerve pathways. The most frequent are meningiomas and vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has emerged as a valuable treatment, with heterogeneity of clinical results. We sought to review the medical literature on TN treated with SRS for meningiomas and VS and investigate the rates of improvement of TN symptoms.

METHODS

We reviewed articles published between January 1990 and December 2019 in PubMed. Pain relief after SRS, the maintenance of pain relief, and TN recurrence and complications were evaluated with separate meta-analyses, taking into account the data on individual patients.

RESULTS

Pain relief after SRS was reported as Barrow Neurological Institute (BNI) pain intensity scores of BNI I in 50.5% (range 36-65.1%) of patients and BNI I-IIIb in 83.8% (range 77.8-89.8%). There was no significant difference in series discussing outcomes for tumor targeting versus tumor and nerve targeting. Recurrences were described in 34.7% (range 21.7-47.6; tumor targeting). Maintenance of BNI I was reported in 36.4% (range 20.1-52.7) and BNI I-IIIb in 41.2% (range 29.8-52.7; tumor targeting series). When both the nerve and the tumor were targeted, only 1 series reported 86.7% with BNI I-IIIb at last follow-up. Complications were encountered in 12.6% (range 6.3-18.8; tumor targeting series) of patients; however, they were much higher, as high as 26.7%, in the only study reporting them after targeting both the nerve and the tumor. The most common complication was facial numbness.

CONCLUSION

SRS for TNB secondary to benign tumors, such as meningiomas and VS, is associated with favorable clinical course, but less favorable than in idiopathic TN. There was, however, heterogeneity among reports and targeting approaches. Although targeting both the nerve and the tumor seemed to achieve better long-term results, the rate of complications was much higher and the number of patients treated was limited. Future clinical studies should focus on the standard reporting of clinical outcomes and randomization of targeting methods.

A Case of Meningioma Originating from the Oculomotor Nerve

BACKGROUND

Schwannoma originating from the oculomotor nerve has been reported. However, meningioma originating from this nerve was unknown.

CASE DESCRIPTION

A 22-year-old woman presented with a unique case of meningioma originating from the oculomotor nerve manifesting as periorbital pain and diplopia beginning 4 months previously. Oculomotor nerve schwannoma was suggested by several pretreatment examinations. Tumor resection was considered risky for preservation of the oculomotor nerve function; therefore, gamma knife surgery (GKS) was performed. Six months later, she suffered right complete ptosis and worsened blurry vision. Corticosteroid was administered, but her symptoms did not improve. Magnetic resonance imaging showed the tumor lesion had grown larger. We decided to resect the tumor lesion because of her uncontrolled periorbital pain. The tumor had occupied the oculomotor cistern and was gross totally removed. Histologic diagnosis was surprisingly transitional meningioma. The tumor lesion occupied the oculomotor cistern and was refractory to GKS, with a progressive clinical course, which is more suggestive of meningioma than schwannoma, although extremely rare. Her periorbital pain and blurry vision gradually regressed, whereas complete oculomotor nerve palsy persisted.

CONCLUSIONS

In such a case, tumor resection after GKS should be considered.

A case of impaired consciousness due to large cystic metastatic brain tumors from lung adenocarcinoma successfully controlled with Ommaya reservoir placement

Large cystic brain metastases from lung cancer are rare but cause substantial central nervous system symptoms that often deprive patients of opportunities to receive anticancer therapy. There are no standard therapeutic strategies against this relentless condition. Here we report a patient with large cystic brain metastases from lung adenocarcinoma successfully controlled with Ommaya reservoir placement and subsequent gamma knife surgery (GKS). A 62-year-old Japanese man presented with left upper extremity paresis. Magnetic resonance imaging revealed large cystic masses in both cerebral hemispheres and multiple brain nodules. Computed tomography of the chest showed irregular nodular shadows in the lower lobe of the right lung with multiple swollen lymph nodes. His performance status (PS) and level of consciousness worsened rapidly. Thus, at that time, we could not perform bronchoscopy with the goal of establishing a pathological diagnosis. Intracystic placement of an Ommaya reservoir followed by GKS dramatically improved his PS and level of consciousness. We were subsequently able to perform bronchoscopy, which resulted in a diagnosis of lung adenocarcinoma with 100% positivity of programmed cell death-1 ligand-1 expression. The patient was started on a 3-week cycle of pembrolizumab. Substantial reduction in tumor size was observed after one course of pembrolizumab treatment. The patient had a partial remission. He has been still receiving pembrolizumab with long-term efficacy. In conclusion, our report suggests that aggressive Ommaya reservoir placement should be considered for large cystic metastatic brain tumors, even in patients with undiagnosed cancer, poor PS, and impaired consciousness.

Gamma knife surgery-induced aneurysm rupture associated with tissue plasminogen activator injection: A case report and literature review

Background

Cases involving delayed development of intracranial aneurysms related to gamma knife surgery (GKS) have been recently reported. Here, we present a rare case of GKS-induced aneurysm rupture after intravenous injection of tissue plasminogen activator (t-PA) for occlusion of the middle cerebral artery (MCA). To the best of our knowledge, this is the first case in which t-PA-induced rupture of a GKS-related unruptured aneurysm.

Case Description

A 56-year-old woman underwent GKS for left trigeminal neuralgia. Eighteen years later, she suddenly experienced MCA occlusion with consciousness disturbance and right hemiparesis. She received an intravenous injection of t-PA and then was transferred to our hospital. We confirmed residual thrombus, and she underwent mechanical thrombectomy successfully. A postthrombectomy brain computed tomography scan revealed subarachnoid hemorrhage with a hematoma in the left cerebellar hemisphere. Cerebral angiography revealed a small irregular-shaped aneurysm at the branching site of the left circumflex branch at the distal position of the anterior inferior cerebellar artery, which was not detected on initial imaging. Coil embolization was performed. One month after the ischemic attack, she was transferred to a rehabilitation hospital, with a modified Rankin Scale score of 5.

Conclusions

The tendency to rupture is greater for GKS-induced aneurysms than for intrinsic unruptured aneurysms, according to previous reports. When performing acute treatment for cerebral infarction in patients with a history of GKS, the presence of aneurysms should be evaluated and we should keep in mind that GKS aneurysms are very small and tend to rupture.

Stereotactic Radiosurgery for the Treatment of Chronic Intractable Pain: A Systematic Review

BACKGROUND

Since the advent of neuromodulation, the role and efficacy of stereotactic radiosurgery (SRS) for chronic pain has not been carefully scrutinized.

OBJECTIVE

To perform a systematic review to evaluate the clinical efficacy, both short- and long-term, of SRS for the treatment of chronic intractable pain.

METHODS

A systematic search in PubMed, Web of Science, and PsycINFO was performed using keywords and controlled vocabulary. The search included peer-reviewed articles reporting clinical outcomes of SRS for chronic pain with a minimum 3-mo follow-up for nonmalignant and 1 mo for malignant pain.

RESULTS

Six articles (113 patients) were evaluated on the basis of radiation target (thalamus vs pituitary) and pain etiology (malignant vs nonmalignant). Across studies, at least 35% of patients were reported to have lasting significant pain relief. By cohort, clinical success was achieved in 51% of pituitary SRS, at least 23% of thalamic SRS, 39% of nonmalignant, and at least 33% of malignant pain patients. Adverse events were noted in 21% of patients; the majority related to hormonal deficits from pituitary SRS.

CONCLUSION

Despite decreased utilization, SRS is effective for select patients with chronic pain and is associated with an acceptable complication rate. Pituitary SRS is superior in patients with cancer-related pain (87% success), while thalamic SRS is superior in patients with nonmalignant pain (65% success). Because reports of SRS for pain largely stem from a period before the common use of neuromodulatory and intrathecal therapies, the efficacy in patients who fail such therapies remains unclear and requires further characterization.

Gamma knife surgery efficacy in controlling postoperative residual clival chordoma growth

OBJECTIVE

This study primarily aims to evaluate the efficacy of gamma knife surgery in controlling growth progression rate of residual clival chordoma through retrospective outcome analysis of 12 consecutive patients.

PATIENTS AND METHODS

Data for 12 consecutive patients underwent GKS for post-operative residual histologically verified clival chordoma at our institution (IMC - Cairo- Egypt) from 2006 through end of 2017 were retrospectively reviewed and analyzed with mean follow-up period of 45 months (range12-120 months).

RESULTS

In the last follow up MR, tumor growth control was achieved in 33.3% of patients (mean treated tumors volume was 2.7cc with mean peripheral prescription dose of 16 Gy), and 66.7% of patients reported lost tumor growth control (mean treated tumor volume was 9.2 cc with mean peripheral dose was 13.5 Gy). The overall tumor free progression with mean follow up period of 45mos was 33.3%. The Actuarial 2, 3 and 5 year tumor control rates after initial GKS was 35%, 30% and 25% respectively.

CONCLUSION

Without satisfactory maximum tumor reduction and sufficient high peripheral prescription radiation tumor dose, it should not be expected that GKS could efficiently control the progression of residual clival chordoma, especially for long term.

Adjuvant gamma knife surgery and image-guided, intensity-modulated radiation therapy for the treatment of sacral chordomas

Aim

The aim of this study was to confirm whether patients with sacral chordoma benefit from adjuvant radiotherapy and to determine the optimal photon radiotherapy module for comprehensive treatment.

Background

Chordoma is a rare slow-growing neoplasm arisen from cellular remnants of the notochord. About 50% occur in the sacrococcygeal region. Surgical resection and adjuvant radiation therapy are recommended treatment due to the improving local control rate.

Materials and methods

118 patients treated by surgery and adjuvant radiotherapy from August 2003 to May 2015 were retrospectively analyzed. All patients received surgical resection after diagnosis. Among these patients, 44 were treated by exclusive surgery, and 48 were treated with adjuvant image-guided, intensity-modulated radiation therapy (IG-IMRT). In addition, 26 patients were treated with gamma knife surgery (GKS) after surgical resection. The median follow-up was 54 months for all patients. Kaplan-Meier analysis was used to calculate recurrence-free survival (RFS) overall survival (OS).

Results

Patients treated with adjuvant radiotherapy had better RFS (p = 0.014) than those treated exclusively by surgery. The patients in the IG-IMRT group exhibited better recurrence-free survival (p = 0.01) than the GKS group. Moreover, in the IG-IMRT group, patients treated by higher dose were associated with better RFS (p = 0.04). No significant difference in OS was found. No grade 3 late toxicity was found.

Conclusions

We confirmed that adjuvant radiotherapy improved RFS but not OS in sacral chordoma patients after surgery. Furthermore, favorable RFS and low adverse event rates were observed following IG-IMRT. Our results suggest that high dose IG-IMRT is an appropriate module of adjuvant radiotherapy for sacral chordoma patients.

Prophylactic Bevacizumab May Mitigate Radiation Injury: An Experimental Study

BACKGROUND

Stereotactic radiosurgery (SRS) is widely used to treat brain pathologies alone or in concert with other treatment modalities. However, there are some side effects, such as radiation injury characterized by edema and necrosis in peripheral tissues, that must be managed. A new treatment agent against this side effect is bevacizumab, which targets increased vascular endothelial growth factor (VEGF) as a prominent etiologic factor in radiation injury. In this study, we created a rat experimental model to describe the effects of both radiation and the anti-VEGF monoclonal antibody bevacizumab following high-dose SRS, and to compare the effects of prophylactic and delayed-onset bevacizumab treatment.

METHODS

Fifty-four adult male Wistar rats were allocated into 9 groups based on differing Gamma-knife surgery (GKS) doses and bevacizumab treatment protocols. After 12 weeks, the rats' right frontal lobes were examined with hematoxylin and eosin staining and immunohistochemistry analysis via VEGF and CD31 antibodies.

RESULTS

Radiation necrosis occurred to varying degrees in all irradiated animals between 3 and 10 weeks post-SRS. Higher GKS dose (50% isodose of 100 Gy) led earlier necrosis and prophylaxis of bevacizumab at this dose was associated with delayed onset of necrosis. Moreover, prophylactic bevacizumab mitigated the effects of radiation necrosis following GKS at both doses, whereas this effect was not prominent with late initiation of bevacizumab (treatment protocol).

CONCLUSIONS

Our findings show that the onset and degree of radiation injury are affected by the GKS dose and protocol of bevacizumab administration.

Clinical features of brain metastases from hepatocellular carcinoma using gamma knife surgery

Background

Brain metastases from hepatocellular carcinoma (HCC) are rare, but their incidence is increasing because of developments in recent therapeutic advances. The purpose of this study was to investigate the characteristics of brain metastases from HCC, to evaluate the predictive factors, and to assess the efficacy of gamma knife surgery (GKS).

Method

A retrospective study was performed on patients with brain metastases from HCC who were treated at Tokyo Gamma Unit Center from 2005 to 2014.

Results

Nineteen patients were identified. The median age at diagnosis of brain metastases was 67.0 years. Fifteen patients were male and four patients were female. Six patients were infected with hepatitis B virus (HBV). Two patients were infected with hepatitis C virus (HCV). Eleven patients were not infected with HBV or HCV. The median interval from the diagnosis of HCC to brain metastases was 32.0 months. The median number of brain metastases was two. The median Karnofsky performance score at first GKS was 70. The median survival time following brain metastases was 21.0 weeks. Six-month and 1-year survival rates were 41.2 and 0%, respectively. One month after GKS, no tumor showed progressive disease. The HBV infection (positive vs. negative) was significantly associated with survival according to univariate analysis (p = 0.002).

Conclusions

The patients having brain metastases from HCC had poor prognosis and low performance state. Therefore, GKS is an acceptable option for controlling brain metastases from HCC because GKS is noninvasive remedy and local control is reasonable.

Multimodal treatments combined with gamma knife surgery for primary atypical teratoid/rhabdoid tumor of the central nervous system: a single-institute experience of 18 patients

OBJECTIVES

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, highly malignant tumor of the central nervous system with poor prognosis. Nowadays, multimodal management, including surgery, chemotherapy (CMT), and radiation therapy (RT), is advocated. However, AT/RT treatment with gamma knife surgery (GKS) was rarely reported. The aim of this study was to assess the efficacy and safety of GKS for the treatment of AT/RT.

PATIENTS AND METHODS

Medical records of AT/RT patients who underwent surgery from 2007 to 2014 at the West China Hospital were retrospectively reviewed and statistically analyzed.

RESULTS

Eighteen patients (12 males and 6 females) were presented with AT/RTs. Median age during presentation was 20.5 months (range, 4-179 months). Twelve patients were < 3 years and six patients were > 3 years. Tumor location was supratentorial in seven patients, infratentorial in ten patients, and center area of the brain in one patient. Treatments performed were as follows: surgery alone in two patients, surgery+RT in two patients, surgery+CMT in five patients, surgery+CMT+RT in two patients, and surgery+CMT+RT+GKS in seven patients. The 2-year overall survival (OS) rate and event-free survival (EFS) rate for all 18 consecutive patients were 33.3 and 27.8%, respectively. Cox regression analyses showed that multimodal management combined with GKS was an independent positive prognostic factor for OS.

CONCLUSIONS

Although AT/RTs are lethal cancer types, the OS of the disease was improved by using multimodal therapeutic strategies, including surgery, CMT, and RT, combined with GKS.

Long-term effectiveness and safety of stereotactic gamma knife surgery as a primary sole treatment in the management of glomus jagulare tumor

OBJECTIVE

This study aims to report and confirm long-term effectiveness and safety of stereotactic Gamma Knife Surgery as a primary sole treatment in the management of 40 glomus jagulare tumors patients.

PATIENTS AND METHODS

Retrospective analysis of clinical and radiological outcomes of 40 GJTs consecutive patients treated with GKS as primary sole treatment at International Medical Center (IMC), Cairo-Egypt from the beginning of 2005 till the end of 2014,with mean follow-up period of 84 months (range 36-156 months), mean tumor volume was 6.5 cc, and mean peripheral radiation dose of 15 Gy, to mean isodose curve of 38%.

RESULTS

The most common neurological deficit at initial evaluation was bulbar symptoms in 24 patients, followed by pulsatile tinnitus in 22, deterioration of hearing in 20 patients. The overall clinical control achieved in 92.5% of patients, while actuarial tumor size control rate post- GKS was 97.5% at 3 years, 97% at 5 years and 92% at 10 years of follow-up period.

CONCLUSIONS

Gamma knife surgery could be used effectively and safely as a primary sole treatment tool in the management of glomus jugulare tumors.

Radiosurgery in trochlear and abducens nerve schwannomas: case series and systematic review

INTRODUCTION

Schwannomas involving the occulomotor cranial nerves  (CNs; III, IV and VI), can be disabling, due to the associated diplopia and decreased quality of life and are extremely rare. We evaluated the role of Gamma Knife surgery (GKS) in these cases.

METHODS

Five patients with CN IV and VI schwannomas (three and two, respectively) were treated in Lausanne University Hospital between 2010 and 2015. Four benefitted from upfront GKS and one from a combined approach (planned subtotal resection followed by GKS), due to a large preoperative tumour volume (size, 3 × 2 × 2.5 cm; volume, 7.9 ml), with symptomatic mass effect and oedema, as well as an entrapement cyst at the brainstem interface, in a young patient. Neuro-ophtalmological evaluation was performed at baseline and during each follow-up time-point. A systematic literature review is presented and compared to the present report.

RESULTS

The mean follow-up was 44.4 months (12-54). Initial clinical presentation was diplopia in four cases and cavernous sinus syndrome in one. The marginal dose was 12 Gy in all cases. The mean target volume was 1.51 cm³ (0.086-5.8). The mean prescription isodose volume (PIV) was 1.71 cm³ (0.131-6.7). At last follow-up, all patients presented with disappearance of the baseline symptoms. Tumour control was achieved in 100%, with decrease in volume in all cases. The systematic review analysed 11 peer-reviewed studies, with a total of 35 patients. For uniformly reported CN VI, the mean marginal radiation dose ranged between 12 and 12.5 Gy, with disappearance of symptoms in 12.5%, improvement in 31.25%, stabilisation in 6.25%, worsening in 12.5%. Tumour volume decreased in all cases.

CONCLUSIONS

Our data suggest that first intention GKS is a safe and effective option for patients with small to medium size oculomotor schwannomas, providing a high rate of clinical alleviation and tumour control. When the initial tumour volume is too large for first intention GKS, a combined approach with planned subtotal resection followed by GKS can be performed, with favourable and comparable outcomes as in upfront GKS.

Gamma Knife Surgery for Recurrent Trigeminal Neuralgia in Cases with Previous Microvascular Decompression

BACKGROUND

Microvascular decompression (MVD) and Gamma Knife surgery (GKS) are the primary treatments for trigeminal neuralgia (TN). However, many patients require further surgical treatment after initial surgery for recurrent TN. The aim of this study was to evaluate efficacy and safety of GKS for recurrent TN cases with prior MVD.

METHODS

From October 2008 to June 2015, 658 patients at West China Hospital underwent GKS as the only surgical treatment, and 42 patients underwent GKS with prior MVD. The single 4-mm isocenter was located at the cisternal portion of the trigeminal nerve in all patients. Median maximum prescription dose was 85 Gy (range, 70-90 Gy).

RESULTS

Median follow-up time was 6.2 years (range, 1.1-10 years). The percentage of patients with or without previous MVD within 1 year was 56.81%, and the percentage of patients who were pain-free was 74.74%. The recurrence rates within 10 years were 49.11% and 43.74% for patients with and without MVD, respectively. Also, 9.52% and 11.04% of patients with and without previous MVD experienced complications as a result of GKS during the long-term follow-up period. Patients who underwent previous MVD showed a significantly lower pain-free rate compared with patients without previous MVD (P = 0.01). There was no statistical significance in the recurrence rate (P = 0.82) or the complications (P = 0.93) in the 2 groups during the long-term follow-up period.

CONCLUSIONS

For patients with recurrent TN who previously underwent MVD, GKS remains an efficacious and safe mode of treatment.

Microvascular decompression for trigeminal neuralgia in patients with failed gamma knife surgery: Analysis of efficacy and safety

OBJECTIVE

Though it is usually successful, failure or delayed pain recurrence may occur after gamma knife surgery (GKS) in patients with trigeminal neuralgia (TN), and additional intervention may be required. This study aimed to investigate whether the safety and efficacy of microvascular decompression (MVD) were influenced by prior GKS.

PATIENTS AND METHODS

The authors retrospectively evaluated 36 consecutive TN patients who underwent MVD after failed GKS from January 2012 to June 2013. The clinical features, operative findings and surgical outcomes were reviewed and statistically analyzed, and the operation results were further compared with a cohort of 60 patients with no prior GKS.

RESULTS

At surgery, atrophy of the trigeminal nerve was observed in 13 patients (36.1%), arachnoid thickening in 6 patients (16.7%), adhesions between vessels and the trigeminal nerve in 8 patients (22.2%), and atherosclerotic plaque in the offending vessels in 3 patients (8.3%). The complete pain relief rates were 83.3% immediately after MVD and 72.2% at last follow-up, which showed no statistical difference when compared with patients without GKS. New or worsened facial numbness occurred in 7 patients (19.4%), which was significantly higher than those without GKS (p=0.02). Univariate analysis suggested that a positive pain response to the prior GKS correlated with better long-term outcome (p=0.015), and the existence of arachnoid adhesions correlated with higher risk of facial numbness (p=0.03).

CONCLUSIONS

MVD remains an appropriate and effective alternative therapy for patients with failed GKS, with no added technical difficulty. However, the risk of facial numbness seems to be higher than those with MVD alone.

Gamma knife radiosurgery for brainstem cavernous malformations

OBJECTIVE

The goal of this retrospective study was to evaluate the efficacy and safety of gamma knife radiosurgery (GKS) for the treatment of brainstem cavernous malformations (CMs).

METHODS

Between January of 2009 and December of 2014, 43 patients (20 males and 23 females) with brainstem CMs were treated at the West China Hospital, Sichuan University, Gamma Knife Center. The mean age of these patients was 41.7 years. All of the patients experienced 1 or more episodes of symptomatic bleeding (range 1-4) before undergoing GKS. The mean volume of the malformations at the time of GKS was 442.1mm³, and the mean prescribed marginal radiation dose was 11.9Gy. The mean follow-up period after radiosurgery was 36 months (range 12-120 months).

RESULTS

Before GKS, 50 hemorrhages (1.2 per patient) were observed (25.0% annual hemorrhage rate). Three hemorrhages following GKS were observed within the first 2 years (3.92% annual hemorrhage rate), and 1 hemorrhage was observed in the period after the first 2 years (1.85% annual hemorrhage rate). In this study of 43 patients, new neurological deficits developed in only 1 patient (2.32%; permanent paresthesia on the left side of the face and the right lower limb of the patient). There were no deaths in this study.

CONCLUSION

GKS is a favorable alternative treatment for brainstem CMs. Using a low marginal dose treatment might reduce the rate of hemorrhage and radiation-induced complications.

Not all that glitters is gold: A guide to surgical trials in epilepsy

Epilepsy surgery is often the only effective treatment in appropriately selected patients with drug‐resistant epilepsy, a disease affecting about 30% of those with epilepsy. We review the evidence supporting the use of epilepsy surgery, with a focus on randomized controlled trials (RCTs). Second, we identify gaps in knowledge about the benefits of epilepsy surgery for certain populations, the challenges of individualizing the choice of surgery, and our lack of understanding of the mechanisms of surgical outcomes. We conducted a search (MEDLINE, Embase, Cochrane, Clinicaltrials.gov) on March 2, 2016, to identify epilepsy surgery RCTs, systematic reviews, or health technology assessments (HTAs). Abstracts were screened to identify resective, palliative (e.g., corpus callosotomy, multiple subpial transection [MST]), ablative (e.g., Laser interstitial thermal therapy [LITT], gamma knife radiosurgery [RS]), and neuromodulation (e.g., cerebellar stimulation [CS], hippocampal stimulation [HS], repetitive transcranial magnetic stimulation [rTMS], responsive neurostimulation [RNS], thalamic stimulation [TS], trigeminal nerve stimulation [TNS], and vagal nerve stimulation [VNS]) RCTs. Study characteristics and outcomes were extracted. Knowledge gaps were identified. Of 1,205 abstracts, 20 RCTs were identified (resective surgery including corpus callosotomy [n = 7], MST [n = 0], RS [n = 1, 3 papers], LITT [n = 0], CS [n = 1], HS [n = 2], RNS [n = 1], rTMS [n = 1], TNS [n = 1], TS [n = 1], and VNS [n = 5]). Most studies targeted patients with temporal lobe epilepsy (TLE) and none examined the effectiveness of resective surgical therapies in patients with extra‐TLE (ETLE) or with specific lesions aside from mesial temporal lobe sclerosis. No pediatric surgical RCTs were identified except for VNS. Few RCTs address the effectiveness of surgery in epilepsy and most are of limited generalizability. Future studies are needed to compare the effectiveness of different surgical strategies, better understand the mechanisms of surgical outcomes, and define the ideal surgical approaches, particularly for patients with high or very low cognitive function, normal imaging, or ETLE.

MRI as an essential diagnostic approach for trigeminal neuralgia

Trigeminal neuralgia is a well recognised disorder frequently reported to the dentist. The diagnosis of trigeminal neuralgia is primarily based on history and clinical criteria. The clinical findings do not differentiate idiopathic trigeminal neuralgia from symptomatic trigeminal neuralgia. We describe a case of cliviopetrosal meningioma presenting as trigeminal neuralgia and discuss the importance of magnetic resonance imaging as an essential diagnostic approach when trigeminal neuralgia occurs concurrently with a brain tumour.

Extreme volume expansion of a vestibular schwannoma due to intratumoral hemorrhage after gamma knife radiosurgery

A 48-year-old man with right hemi-facial palsy and cerebellar ataxia was referred to our hospital. Three years and 10 months earlier he had undergone gamma knife radiosurgery (GKRS) at the referring hospital for an 18 mm right vestibular schwannoma. Slight tumor enlargement had been observed on MRI performed at the referring hospital 3 years after the GKRS. On close follow-up after another 6 months an MRI showed an obvious enlargement of the tumor. An MRI on admission revealed an iso-intense mass lesion measuring 36 mm in maximum diameter at the right cerebellopontine angle. A two stage surgery was conducted using a retrosigmoid approach because bleeding from the tumor wall was difficult to control intraoperatively during the first operation. At the second operation, the majority of the tumor capsule had converted to necrotic tissue. A large hematoma cavity was present inside the tumor capsule which explained the rapid increase in size over a short period of time. Near total removal was achieved. Histopathological examination revealed massive intratumoral hemorrhage within a typical vestibular schwannoma with no malignancy. The complication of intratumoral hemorrhage is very rare and the utility of stereotactic radiation surgery/therapy, including GKRS, for vestibular schwannoma is well known. However, we must emphasize that careful follow-up is still required, even after several years.

Clinical outcome with gamma-knife surgery or surgery for brain metastases from colorectal cancer

The aim of this study was to investigate the clinical outcomes after gamma knife surgery (GKS) or surgery as the first treatment for brain metastases in colorectal cancer (CRC). Of the 4350 patients diagnosed with CRC at our institution identified from 1987 to 2009, 27 patients who underwent GKS (GKS group) and 11 who underwent surgery (surgery group) were included. The oncologic outcomes were compared between the two groups. Local control was significantly better in the surgery group than in the GKS group (90% versus [vs.] 71.4%, respectively; p=0.006). The rate of symptom relief after 3 months was significantly higher in the surgery group than in the GKS group (72.7 vs.18.5%, respectively; p=0.005). The median survival after GKS was 5.6 months and surgery was 16.2 months. In multivariate analysis, controlled primary tumor (p=0.038) and solitary metastasis (p=0.028) were correlated with prolonged overall survival, whereas surgery (p=0.034) was associated with longer local control. Surgery for brain metastasis from CRC is more advantageous in local control and neurologic symptom palliation than GSK. In multivariate analysis, overall survival was associated with controlled primary tumor and solitary metastasis.