Stereotactic radiosurgery for cavernous sinus hemangiomas

The Treatment Outcomes of Radiotherapy and Surgical Treatment for Patients with Cavernous Sinus Hemangioma: A Meta-Analysis

OBJECTIVE

Cavernous sinus hemangiomas (CSHs) are infrequent benign neoplasms. This meta-analysis was conducted with the objective of examining the prognostic outcomes of surgical interventions and radiotherapy (RT) in patients diagnosed with CSHs.

METHODS

A comprehensive literature search was performed across PubMed, Embase, and Web of Science databases, with traceability up to June 22, 2021. The evaluation of continuous variables was conducted by applying the weighted mean difference (WMD) and 95% confidence interval. A one-arm meta-analysis was used to scrutinize the tumor control rate, clinical improvement rate, recovery rates of abducens nerve palsy and visual disturbance, total resection rate, and the incidence rate of permanent nerve palsy post-treatment.

RESULTS

In total, 29 articles were incorporated into the meta-analysis. Post-RT for CSHs, a significant reduction in tumor volume was observed (WMD [95% confidence interval] = -17.16 [-21.52, -12.80] cm3). The tumor control rate, clinical improvement rate, recovery rate of abducens nerve palsy, and the recovery rate of visual disturbance were 97.1% (92.9, 99.7), 91.9% (82.3, 98.5), 95.6% (83.2, 100.0), and 86.3% (65.0, 99.5), respectively. Following surgical treatment, the total resection rate, mean intraoperative blood loss, recovery rate of visual disturbance, incidence rate of permanent nerve palsy, and recovery rate of abducens nerve palsy were 73.2% (57.1, 86.9), 971.17 mL (584.07, 1358.27), 66.4% (32.4, 0.942), 16.0% (4.6, 31.1), and 70.6% (51.0, 87.7), respectively. Notably, the recovery rate of abducens nerve palsy post-RT was markedly higher than postsurgical treatment.

CONCLUSIONS

The results of this meta-analysis underscore that RT is an effective and safe treatment modality for CSHs. Furthermore, the prognostic outcomes of RT demonstrated superiority over surgical intervention.

Personalized Gamma Knife radiosurgery for cavernous sinus hemangiomas: A Chinese single-center retrospective study for 10 years of 187 patients

Background

The aim of this study is to retrospectively review the effectiveness and safety of personalized Gamma Knife radiosurgery (GKRS) for cavernous sinus hemangiomas (CSHs) and to summarize experience of personalized GKRS treatment for different volume of CSHs.

Methods

187 CSHs patients who received personalized GKRS treatment in our center from January 1, 2011 to December 31, 2020 were enrolled in this study and classified into small and medium CSHs (<20 ml), large CSHs (20–40 ml) and giant CSHs (≥40 ml) according to tumor volume. The personalized GKRS treatment strategy included single GKRS and staged GKRS. Tumor shrinkage rate, clinical symptoms response, and complications after GKRS were recorded during the follow-up period. Multivariate factors influencing clinical symptoms response were analyzed after personalized GKRS treatment.

Results

After a mean follow-up duration of 28 months (range 12–124 months), the tumor control rate was 100%, and the mean shrinkage rate of CSHs was 93.2% (61.3%–100%) in the last follow-up. Of the 115 patients with preexisting symptoms, 43 (37.5%) patients showed symptom disappearance, 17 (14.7%) patients demonstrated improvement, and 55 (47.8%) patients remained with no change. Previous surgical resection of CSHs (OR = 0.025, 95% CI 0.007–0.084, P = .000) was identified to be an independent risk factor for no symptom improvement after GKRS treatment.

Conclusions

Personalized GKRS is an effective and safe treatment for different volume of CSHs, which is capable of shrinking the tumor and improving symptoms with extremely low incidence of adverse effects and might be considered as the primary treatment strategy for CSHs.

Less common extracerebral tumors

This chapter examines the results of GKNS on a variety of extraparenchymal skull base tumors some benign and some malignant. For the benign tumors there is good evidence on the effectiveness of the method for pretty much all diagnoses. For malignant extraparenchymal tumors the results are more limited and GKNS only has a supportive role in these lesions.

Long-term outcomes of staged Gamma Knife radiosurgery for giant cavernous sinus hemangiomas: a single-center retrospective study

OBJECTIVE

Cavernous sinus hemangiomas (CSHs) are rare benign tumors originating from the cavernous sinus. Gamma Knife radiosurgery (GKRS) has been recommended as a primary treatment for small- to medium-sized CSHs. The optimal treatment for giant CSHs is still controversial. In this study, the authors retrospectively reviewed the effectiveness and safety of staged GKRS treatment for giant CSHs.

METHODS

Twenty-two patients with giant CSH who received staged GKRS treatment in the Gamma Knife Treatment Center of Henan Province during the period from January 1, 2011, to December 31, 2018, were enrolled in this study. Six patients had received microsurgery before GKRS, the other 16 patients were diagnosed according to clinical symptoms and MR images. All of the enrolled patients received 2-stage GKRS, and the mean interval between the two GKRS treatments was 6.5 months (range 6-12 months). For the first GKRS, the median isodose line was 48% (range 45%-50%), the median marginal dose was 13 Gy (range 11.5-14 Gy), and the median coverage of CSHs was 80% (range 70%-88%). For the second GKRS treatment, the median isodose line was 50% (range 45%-55%), the median marginal dose to the CSHs was 10.5 Gy (range 9-12.5 Gy), and the median coverage of the CSHs was 88% (range 80%-94%).

RESULTS

All of the patients received an outpatient review of an enhanced MR image of the head and a clinical physical check every 6 months after the first GKRS treatment. The mean follow-up duration was 52 months (range 24-84 months). The tumor control rate was 100% 24 months after staged GKRS, and at the last follow-up the mean tumor shrinkage rate was 96.7% (range 90.6%-100%) and the mean residual CSH volume was 2.1 ml (range 0-8.5 ml). Twenty patients suffered central nervous system (CNS) injury symptoms to varying degrees before staged GKRS treatment. Complete symptom recovery was found in 11 (55%) patients, improved symptoms in 5 (25%) patients, and no change in 4 (20%) patients after treatment. Only 1 patient suffered temporary preexisting headache aggravation and 1 patient suffered temporary preexisting diplopia aggravation 1 week after receiving the first GKRS treatment. Subacute or chronic complications were not detected after staged GKRS.

CONCLUSIONS

Staged GKRS is an effective treatment for giant CSHs. Because of the impressively low incidence of adverse effects, staged GKRS may be considered as a primary treatment for giant CSHs.

Cavernous sinus haemangioma with intrasellar extension mimicking non-functioning pituitary adenoma - A case report and review of literature

Fifty-three-year-old male suffering from a presumptive non-functioning pituitary adenoma was qualified for stereotactic radiosurgery in our institution. Two attempts of surgical treatment were taken three months before radiotherapy. Excessive bleeding did not allow to remove the tumour or to take samples for histopathological examination. Diagnosis was put on the basis of radiological assessment and lack of hypersecretion of pituitary hormones. However, radiological reevaluation in our Institute revealed the presence of a well-bounded tumour invading the cavernous sinus with high contrast enhancement in FLAIR and T2-sequence. Moreover, a constriction of the normal pituitary gland with tumour mass was seen. The imaging features of the lesion finally led to diagnosis of cavernous sinus haemangioma with intrasellar expansion. The patient received radiosurgical treatment with the use of linear accelerator (LINAC). A dose of 7 Gy in one fraction was administered to achieve satisfactory local control, prevent potential further bleeding and reduce the risk of progressive neurological deficits. Stable size of the tumour and absence of any complications are confirmed in six years of follow-up.

Adult Parasellar Capillary Hemangioma with Intrasellar Extension

BACKGROUND

Capillary hemangiomata are benign vascular tumors that typically occur in children. They rarely occur in the central nervous system. Intracranial capillary hemangiomata in adults are very rare entities with only 18 cases reported in the literature. We report a case of parasellar capillary hemangiomata that extended into the sella in a 64-year-old woman as well as a review of the literature in adults.

CASE DESCRIPTION

We report a 64-year-old patient who presented with a headache, left-sided paresthesia, and weakness. Initial computed tomography of her brain showed a left-sided 3 cm × 2.5 cm parasellar lesion with intrasellar extension and no mass effect. Subsequent magnetic resonance imaging (MRI) showed a lesion that was homogenously hyperintense on T2-weighted MRI and fluid-attenuated inversion recovery, isointense with adjacent brain parenchyma on T1-weighted MRI, and which demonstrated enhancement after contrast administration. The patient initially underwent an endoscopic transsphenoidal biopsy, which was inconclusive, followed by a craniotomy, biopsy, and debulking. Histologic examination showed fibrous tissue containing numerous thin-walled and irregular vascular channels of varying sizes. There was a very mild associated inflammatory infiltrate, mainly formed of small mononuclear chronic inflammatory cells and occasional histiocytes. The histologic appearances were in keeping with capillary hemangiomata.

CONCLUSIONS

Capillary hemangiomata related to the sella are very rare and can easily be misdiagnosed on imaging alone. The present case highlights capillary hemangiomata as an important, albeit rare, differential when considering a sellar or parasellar mass.

Clinical Features, Intradural Transcavernous Surgical Management, and Outcomes of Giant Cavernous Sinus Hemangiomas: A Single-Institution Experience

BACKGROUND

Cavernous sinus hemangiomas (CSHs) are rare vascular tumors. Stereotactic radiosurgery is an effective treatment for small CSHs. The optimal treatment for giant CSHs is controversial. This study reports advantages of a complete intradural transcavernous approach in total resection of CSHs.

METHODS

Between January 2012 and January 2017, 15 patients with giant CSHs were treated surgically. All cases were evaluated with a contrast-enhanced magnetic resonance imaging scan and confirmed histopathologically. A complete intradural approach was used for all patients. Clinical manifestations, radiographic characteristics, operative techniques, and outcomes of patients were analyzed.

RESULTS

Headache was the most common initial symptom, followed by decreased visual acuity and diplopia. Postoperative magnetic resonance imaging showed that gross total resection was achieved in 13 patients. Two patients had experienced total ipsilateral visual loss for several years before surgery; vision improved in all remaining patients with preoperative visual diminution. The most common early neurologic deficit was cranial nerve VI dysfunction, which was observed in 9 patients (60%; 5 new deficits). Only 2 patients (13.3%) experienced permanent morbidity on long-term follow-up. The early postoperative morbidity rate for cranial nerve III dysfunction was 33.3% (5 patients), and only 1 patient (6.7%) experienced permanent morbidity. Four patients (26.7%) had slight postoperative facial numbness.

CONCLUSIONS

Surgical total resection is the primary and reasonable choice for giant CSHs. Microsurgical resection of giant CSHs through a completely intradural transcavernous approach is an alternative treatment option for giant CSHs.

Safety and efficacy of single-fraction gamma knife radiosurgery for benign confined cavernous sinus tumors: our experience and literature review

Gamma knife radiosurgery (GKRS) has emerged as a suitable primary treatment option for confined cavernous sinus tumors (CSTs) and residual/recurrent benign tumors extending from the surrounding neighborhood. The aim of this review was to further investigate the safety and efficacy of single-fraction GKRS for primary confined CSTs (hemangioma, meningioma, and schwannoma). This was a retrospective analysis of 16 patients of CSTs, primarily treated with GKRS between 2009 and 2017. The patients underwent follow-up clinical and radiological evaluation at a regular interval. Data on clinical and imaging parameters were analyzed. The published literature on GKRS for CSTs was reviewed. There were total 16 patients (eight meningiomas, seven hemangiomas, and one schwannoma). Patients presented with a headache (56.3%), ptosis (50%), and/or restricted extraocular movements (50%). There was 46.6% tumor volume (TV) reduction after single-fraction GKRS. Hemangiomas showed best TV reduction (64% reduction at > 3-year follow-up) followed by schwannoma (41.5%) and meningioma (25.4%). 56.3% of patients developed transient hypoesthesia in trigeminal nerve distribution. 44.4% of patients became completely pain-free. Among cranial nerves, the superior division of the oculomotor nerve showed best outcome (ptosis 62.5%) followed by an improved range of EOM. There was no adverse event in the form of new-onset deficit, vascular complication, or malignant transformation except for one out of the field failures. Among available treatment options, GKRS is the most suitable option by virtue of its minimally invasive nature, optimal long-term tumor control, improvement in cranial neuropathies, cost-effectiveness, favorable risk-benefit ratio, and minimal long-term complications.

Role of fractionated radiotherapy in patients with hemangioma of the cavernous sinus

Purpose

We performed this retrospective study to investigate the outcomes of patients with hemangioma of the cavernous sinus after fractionated radiotherapy.

Materials and Methods

We analyzed 10 patients with hemangioma of the cavernous sinus who were treated with conventional radiotherapy between January 2000 and December 2016. The median patient age was 54 years (range, 31–65 years), and 8 patients (80.0%) were female. The mean hemangioma volume was 34.1 cm³ (range, 6.8–83.2 cm³), and fractionated radiation was administered to a total dose of 50–54 Gy with a daily dose of 2 Gy.

Results

The median follow-up period was 6.8 years (range, 2.2–8.8 years). At last follow-up, the volume of the tumor had decreased in all patients. The average tumor volume reduction rate from the initial volume was 72.9% (range, 18.9–95.3%). All 10 of the cranial neuropathies observed before radiation therapy had improved, with complete symptomatic remission in 9 cases (90%) and partial remission in 1 case (10%). No new acute neurologic impairments were reported after radiotherapy. One probable compressive optic neuropathy was observed at 1 year after radiotherapy.

Conclusion

Fractionated radiotherapy achieves both symptomatic and radiologic improvements. It is a well-tolerated treatment modality for hemangiomas of the cavernous sinus.

Gamma Knife surgery for a hemangioma of the cavernous sinus in an adult: Case report and short review of the literature

Cavernous sinus hemangiomas (CSH) are rare benign extra-axial vascular lesions. Both radiological and clinical aspects are important, for deciding a therapeutic modality, including medical treatment, radiation therapy or microsurgery. In the particular case of CSH, a radical removal of the tumor often cannot be achieved and is associated with a considerable risk for intraoperative uncontrollable bleeding. An alternative treatment modality is radiosurgery. Here we report the case of a 45-year-old patient, who presented with diplopia due to left abducens nerve palsy. A left-sided cavernous sinus lesion was found, initially considered to be a meningioma. However, after serial MR acquisitions, a progressive and heterogeneous enhancement was observed. In order to clarify the diagnosis between meningioma and hemangioma, a diagnostic Tc-99m labeled red blood cells (RBC) scintigraphy (Tc-99m RBC scintigraphy) was performed and showed a typical perfusion blood pool mismatch, with accumulation of the RBC at the level of the left CS, which is typical for a hemangioma. The patient underwent Gamma Knife surgery. The CSH showed a significant reduction in size starting 6 months after treatment and a full regression of the left abducens nerve palsy was observed within 1 year. These clinical and radiological results persisted over the next 3 years.

Hypofractionated stereotactic radiosurgery: a new treatment strategy for giant cavernous sinus hemangiomas

OBJECTIVE Cavernous sinus hemangiomas (CSHs) are rare benign vascular tumors that arise from the dural venous sinuses lateral to the sella. Stereotactic radiosurgery (SRS) has emerged as a principal alternative to microresection for small- and medium-sized CSHs. Resection is a reasonable option for large (3-4 cm in diameter) and giant (> 4 cm in diameter) CSHs. However, management of giant CSHs remains a challenge for neurosurgeons because of the high rates of morbidity and even death that stem from uncontrollable and massive hemorrhage during surgery. The authors report here the results of their study on the use of hypofractionated SRS (H-SRS) to treat giant CSH. METHODS Between January 2008 and April 2014, 31 patients with a giant CSH (tumor volume > 40 cm³, > 4 cm in diameter) treated using CyberKnife radiosurgery were enrolled in a cohort study. Clinical status and targeted reduction of tumor volume were evaluated by means of serial MRI. The diagnosis for 27 patients was determined on the basis of typical imaging features. In 4 patients, the diagnosis of CSH was confirmed histopathologically. The median CSH volume was 64.4 cm³ (range 40.9-145.3 cm³). Three or 4 sessions of CyberKnife radiosurgery were used with a prescription dose based on the intent to cover the entire tumor with a higher dose while ensuring dose limitation to the visual pathways and brainstem. The median marginal dose to the tumor was 21 Gy (range 19.5-21 Gy) in 3 fractions for 11 patients and 22 Gy (range 18-22 Gy) in 4 fractions for 20 patients. RESULTS The median duration of follow-up was 30 months (range 6-78 months) for all patients. Follow-up MRI scans revealed a median tumor volume reduction of 88.1% (62.3%-99.4%) at last examination compared with the pretreatment volume. Ten patients developed new or aggravated temporary headache and 5 experienced vomiting during the treatment; these acute symptoms were relieved completely after steroid administration. Among the 30 patients with symptoms observed before treatment, 19 achieved complete symptomatic remission, and 11 had partial remission. One patient reported seizures, which were controlled after antiepileptic drug administration. No radiation-induced neurological deficits or delayed complications were reported during the follow-up period. CONCLUSIONS Hypofractionated SRS was an effective and safe modality for treating giant CSH. Considering the risks involved with microsurgery, it is possible that H-SRS might be able to serve as a definitive primary treatment option for giant CSH.

Gamma Knife Surgery for Cavernous Sinus Hemanginoma: A Report of 32 Cases

BACKGROUND

Cavernous sinus hemangioma (CSH) is a rare type of benign vascular tumor. Microsurgery for CSH treatment usually results in profuse bleeding and cranial nerve injury. Radiosurgery is an alternative treatment for CSH. The objective of this study was to elucidate the efficacy and safety of gamma knife surgery (GKS) for the treatment of CSH.

METHODS

A total of 32 patients with CSH underwent 34 times of GKS as a primary and exclusive treatment from 2009 to 2015 at West China Hospital. The diagnosis was mainly based on findings of magnetic resonance imaging. The treatment was performed with the Leksell Gamma Knife model C. The follow-up period was from 12-67 months. Changes in imaging results and signs or symptoms were analyzed. Studies of patients who had undergone radiosurgery and microsurgery were compared.

RESULTS

Clinical improvement was observed after GKS in 26 of 27 patients who presented with signs or symptoms of CSH. Tumor shrinkage was detected in all cases. A reduction in tumor volume of 0-25%, 26%-50%, 51%-75%, and 76%-100% was observed in 3, 2, 8, and 19 cases, respectively. Remarkable tumor shrinkage occurred within 6-12 months after GKS. According to a retrospective analysis of 151 patients diagnosed with CSH, 77 patients underwent GKS without any complications, 17 of 74 patients were treated with microsurgery and exhibited persistent complications, and 1 patient died.

CONCLUSIONS

GKS is a safe and effective treatment for most cases of CSH. The concept of GKS as an adjuvant treatment for CSH requires reconsideration.

Gamma Knife radiosurgery for the treatment of cavernous sinus hemangiomas

The present retrospective study aimed to analyze the outcome of patients with cavernous sinus hemangioma (CSH) treated with Gamma Knife radiosurgery (GKS). Between August 2011 and April 2014, 7 patients with CSHs underwent GKS. GKS was performed as the sole treatment option in 5 patients, whilst partial resection had been performed previously in 1 patient and biopsy had been performed in 1 patient. The mean volume of the tumors at the time of GKS was 12.5±10.2 cm³ (range, 5.3-33.2 cm³), and the median prescription of peripheral dose was 14.0 Gy (range, 10.0-15.0 Gy). The mean follow-up period was 20 months (range, 6-40 months). At the last follow-up, the lesion volume had decreased in all patients, and all cranial neuropathies observed prior to GKS had improved. There were no radiation-induced neuropathies or complications during the follow-up period. GKS appears to be an effective and safe treatment modality for the management of CSHs.

Radiosurgical considerations for cavernous sinus hemangioma: long-term clinical outcomes

BACKGROUND

Cavernous hemangiomas are rare vascular tumors in the cavernous sinus. Cranial neuropathies induced by cavernous sinus hemangiomas (CSH) necessitate tumor reduction, but surgery is extremely difficult due to the abundant vascularization of the lesion. We studied the effectiveness and safety of Gamma Knife radiosurgery (GKRS) for CSH.

METHODS

We performed a retrospective analysis of 25 patients with CSH who were treated by GKRS between March 1992 and December 2014. Age, sex, target volume, and irradiation dose were analyzed as prognostic factors for CSH treated by GKRS.

RESULTS

Eleven (84.6 %) patients had tumor shrinkage within 12 months after GKRS. Two patients experienced tumor progression, but tumor size decreased over 2 years after GKRS. No patients had permanent complications, and all patients experienced symptomatic improvement. There were no significant factors that predicted the prognosis of CSH.

CONCLUSIONS

The optimal treatment for CSH has been unclear; however, in this study, GKRS was an effective and safe treatment for CSH. Thus, GKRS may be a primary treatment for CSHs in high-risk surgery patients.

A new classification and clinical results of Gamma Knife radiosurgery for cavernous sinus hemangiomas: a report of 53 cases

BACKGROUND

Cavernous sinus hemangiomas (CaSHs) are rare vascular lesions in the cavernous sinus(CS). Gamma Knife radiosurgery (GKS) provides a treatment modality alternative to microsurgery. This study was conducted to describe a new classification of CaSHs based on their magnetic resonance (MR) imaging findings and determine the efficacy and safety of GKS in a large series of CaSH patients.

METHODS

From April 2007 to November 2012, 53 patients harboring CaSHs were treated using Leksell Gamma Knife model C (before April 2012) or Perfexion (from May 2012 ) at the Gamma Knife Center of Huashan Hospital. Of the 53 patients, 15 with definitive histopathologic diagnoses after surgery, 38 were diagnosed based on their MR imaging findings. There were 15 male and 38 female patients with a mean age of 52 (range, 25-76) years old. The characteristics of MR images of CaSHs were their extremely high homogeneous intensity on T2-weighted and FLAIR images: as bright as cerebrospinal fluid signal. According to the relationship between the carotid line and their location, CaSHs were classified into three types: the intrasellar, parasellar and mixed type. The mean volume of the tumors was 13.2 ± 8.2 cm(3) (range, 1-41 cm(3)). A mean marginal dose of 13.3 Gy (range, 8-15 Gy) was directed to the 49%-64% isodose line (mean 53%).

RESULTS

Of the 53 tumors, 6 (11%) were classified as intrasellar type. Eight (15%) were parasellar type and the other 39 cases(74%) mixed type. The mean radiological and clinical follow-up time of this study was 24 (range, 2-67 months) and 34 months (range, 2-73 months), respectively. The tumor control rate was 100%. The mean tumor volume reduction was 79.5% (range, 16.5%-100%) compared with the pre-GKS volume. Six months after GKS, MR imaging revealed an average of 60.2% tumor volume reduction (range, 16.5%-89.2%). Twenty-nine cases (55%) showed a >80% tumor volume decrease. Neurologically, only two of these patients showed clinical deterioration, and 33 patients demonstrated an obvious improvement in ocular or endocrine disorders. At last follow-up, there were no more complications related to GKS, and none of the tumors progressed.

CONCLUSIONS

Our study showed that GKS is a useful and safe therapeutic method for CaSHs as both a primary and adjuvant treatment. The new classification of CaSHs may help predict their clinical course during tumor development and treatment response after GKS. Further studies with long-term follow-up and larger numbers of cases are necessary to optimize the treatment conditions and verify the benefit of this treatment.

Cavernous sinus cavernous hemangioma: imaging features and therapeutic effect of Gamma Knife radiosurgery

OBJECT

To investigate the imaging features of cavernous sinus cavernous hemangioma (CSCH) and evaluate the therapeutic effect of Gamma Knife radiosurgery (GKRS) in treatment of CSCH.

METHODS AND MATERIALS

Fifteen patients with CSCH treated by GKRS in our institute, including 6 males and 9 females, age range 20-77 years old, were analyzed retrospectively. Three of them were given craniotomies as the initial therapy. All cases had performed conventional and contrast-enhanced MRI and 5 patients underwent dynamic enhanced MRI preoperatively. In 6 cases, the multi-directional continuous data of axial, coronal and sagittal enhanced MRI were acquired. Three cases performed digital subtraction angiography (DSA) simultaneously. The diagnoses of lesions were determined mainly depending on typical imaging features. In 3 patients, the diagnoses of CSCH were confirmed histopathologically. The radiation dosimetry was done with a goal of conformal and selective coverage of the lesion with a 50% prescription isodose line. The mean marginal dose constituted 13.4 Gy (range 10-16 Gy). After GKRS was performed, all patients were arranged regular clinical and MRI follow-up every 6 months during the first 12 months, and once per year thereafter.

RESULTS

On MRI, the lesions were typically demonstrated as iso/hypo-intensities on T1WI and remarkable hyper-intensities on T2WI, and apparent homogeneous enhancement. The phenomenon of dynamic enhancement was found in 11 cases. The progressive enhancing process from heterogeneous to uniform was displayed in the 5 patients performed same-slice dynamic MRI, including imaging characteristics of 'edge to center' enhancement in 2 case. In the other 6 cases, the delayed homogeneous enhancement of lesion was observed. Ten patients obtained radiological follow-up results after GKRS. Reviewing the follow-up data of 8 patients during the period of 3-6 months, the lesions were apparently shrunk in 5 patients with shrinkage rate of 20.8-46.8%. In 4 patients with imaging follow-up during the period of 6-12 months, the lesions of 3 patients were remarkably shrunk with shrinkage rate of 53.5-81.7%. Four patients had imaging follow-up data over 12 months, and all their lesion sizes were reduced with shrinkage rate of 19-83.6%. The clinical presentations of all patients after GKRS were followed up during the period of 1-30 months. In 7 of 9 cases with headache, the symptom was improved; in 5 of 6 cases, facial hypesthesia was improved; in 6 of 9 cases with visual impairments, the visions were markedly improved; and in 8 cases with preoperative diplopia, the symptoms were all resolved.

CONCLUSION

Although bright hyper-intensities on T2WI and significant homogeneous enhancement on contrast-enhanced T1WI are considered as typical imaging characteristics of CSCH, the dynamic process of progressive delayed enhancement on contrast-enhanced MR is more persuasive in diagnosis. According to our study, GKRS could be chosen as an effective and safe alternative treatment for CSCH. We consider that using relatively low marginal dose may get better effects in tumor shrinkage and protection of cranial nerves.