The long-term results of gamma knife radiosurgery for hemangioblastomas of the brain

Combined Microsurgery and Radiotherapy for Multiple Spinal Cord Hemangioblastomas with Holocord Syrinx in von Hippel-Lindau Disease: A Case Report

Spinal and cerebellar hemangioblastomas are common in von Hippel-Lindau disease (vHLD) and usually treated surgically. Multifocal presence and surgically not amenable locations are issues that require a combined microsurgical and radiosurgical approach to control complex cases. We would like to present the case of a 37-year-old male patient who was diagnosed vHLD with multiple spinal and one infratentorial hemangioblastomas and holocord syrinx formation of the whole spinal cord. Combined microsurgical approaches to two spinal lesions and the cerebellar lesion followed by external beam radiotherapy of the posterior fossa and the whole spinal axis stabilized tumor growth of the asymptomatic lesions, while no recurrent tumors were detected at the site of surgery. A clinical deterioration connected to early postoperative deficits stabilized to a moderate gait ataxia. The follow-up after radiotherapy covered 60 months. A combination of microsurgery and radiosurgery for the surgically not amenable lesions is an adequate treatment regimen to stabilize tumor growth and clinical symptoms of multifocal spinal hemangioblastomas in vHLD, though the therapy should be limited to symptomatic or growing lesions.

Assessment of care pattern and outcome in hemangioblastoma

Due to its rarity, current literature assessing prognostic factors and survival outcomes of hemangioblastoma is limited. Patients with histologically confirmed hemangioblastoma were identified from the US National Cancer Data Base. 1488 patients met inclusion criteria. 644 patients underwent gross total resection (GTR), 220 subtotal resection (STR)/biopsy, 60 stereotactic radiosurgery (SRS), 15 external beam radiotherapy (EBRT), 51 surgery followed by radiotherapy (SR + RT) and 498 no treatment. Independent predictors of shorter OS included age ≥ 40 (HR, 3.897; 95% CI, 2.341-6.487; p < 0.001), Charlson-Deyo score ≥ 1(HR, 1.756; 95% CI, 1.213-2.544; p = 0.003), tumor location in the brainstem (HR, 1.955; 95% CI, 1.129-3. 384; p = 0.017) compared to cerebellum, no treatment (HR, 2530; 95% CI, 1.533-4.177; p < 0.001) and receipt of EBRT (HR, 2.860; 95% CI, 1.073-7.618; p = 0.036) compared to STR/biopsy. GTR was associated with longer OS (HR 0.617; 95% CI, 0.391-0.974; p = 0.038), while SRS had comparable OS to STR/biopsy. The overall trend of OS by treatment modality was consistent after matching to age- and sex-matched US population data. In patients younger than 40 years, treatment was not a significant predictor of OS. In conclusion, GTR remained the optimal treatment for hemangioblastoma. SRS may perform similarly to surgery alone. Treatment was not a significant predictor of survival in younger patients.

Stereotactic radiosurgery for central nervous system hemangioblastoma: systematic review and meta-analysis

Hemangioblastomas are rare, benign, vascular tumors of the central nervous system (CNS), often associated with von-hippel lindau (VHL) disease. Current therapeutic options include microsurgical resection or stereotactic radiosurgery (SRS). With no randomized controlled studies and minimal data beyond single-institution reviews, the optimal management approach for patients with CNS hemangioblastomas is unclear. We completed a Pubmed/SCOPUS literature search from January 1990 to January 2017 for eligible studies on SRS for CNS hemangioblastomas. Relevant articles were identified and reviewed in accordance to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. 26 studies met eligibility criteria for qualitative synthesis, representing 596 subjects and 1535 tumors. The Gamma Knife was the most published SRS method for CNS hemangioblastomas. After critical study appraisal for intra-study bias, 14 studies were used for quantitative meta-analysis of 5-year progression free survival (PFS). The pooled 5-year PFS across all eligible studies was 88.4%. No difference was observed between spine versus intracranial studies. Individual patient data (IPD) was extracted from 14 studies, representing 322 tumors. Univariate analysis of IPD revealed that VHL patients were younger, and had smaller tumors compared to those with sporadic disease. Adverse events were associated with increasing marginal dose, independent of tumor volume. VHL status, sex, radiosurgical method, tumor location, and tumor volume were not found to be significantly associated with tumor progression. Multiple studies show excellent tumor control at 5-year follow up, however, the long-term efficacy of SRS for CNS hemangioblastomas still needs to be investigated, and the studies exploring the role of SRS for early treatment of asymptomatic lesions is wanting.

Surgical treatment of cerebellar hemangioblastomas

BACKGROUND

Hemangioblastomas (HBL) are uncommon tumors of the central nervous system (CNS), corresponding to 1-2.5% of all intracranial tumors. They can present sporadically or in patients with von Hippel-Lindau (VHL) disease and are most often located in the cerebellum, brainstem, and spinal cord. VHL disease is a multiple neoplasia syndrome inherited in an autosomal dominant fashion and caused by a VHL suppressor gene deletion. We present our experience in the management of patients with cerebellar HBL.

METHODS

Thirty consecutive patients with cerebellar HBL were included in this study. Hospital charts, radiological images, and operative records were reviewed. Modified Rankin scores were used to evaluate the clinical course.

RESULTS

Thirty patients diagnosed with cerebellar HBL were operated. Complete total resection was achieved in 93% of the cases. Postoperatively, 83% of the patients showed good functional recovery.

CONCLUSIONS

HBL of the cerebellum should be resected when symptomatic or when the tumor (or a tumor-associated cyst) shows signs of enlargement. Surgical intent should seek en bloc resection to minimize intraoperative bleeding. Patients with HBLs must be tested for VHL gene mutations, and in confirmed cases, relatives should be offered genetic counseling.

Development of Database and Genomic Medicine for von Hippel-Lindau Disease in Japan

von Hippel-Lindau (VHL) disease is a hereditary tumor disease in which tumors develop in multiple organs, not only as hemangioblastomas (HBs) in the central nervous system, but also as kidney tumors, pheochromocytomas, and so on. Much about the epidemiology of VHL disease remained unknown until fairly recently in Japan, leading to calls for the establishment of a VHL disease epidemiological database in Japanese. To elucidate its epidemiology in Japan, the Japanese Ministry of Health, Labour and Welfare created the VHL Disease Study Group, which was put in charge of carrying out a nationwide epidemiological survey. The survey found close to 400 Japanese VHL disease patients throughout the country. Based on those results, the VHL Disease Study Group created the VHL Disease Treatment Guideline and also a severity classification. It is thought that the prognosis of VHL disease patients can be improved by performing genetic diagnosis and careful follow-up. Accordingly, the University of Tokyo Hospital put in place an in-hospital system for implementing genomic medicine for VHL disease based on genetic diagnosis. For that system, it was especially important to establish (I) accurate genetic diagnostic techniques, (II) genetic counseling capabilities for the patients and their families, and (III) a system of cooperation among multiple departments, including urology departments, and so on. Further elucidation of the epidemiology and the development of genomic medicine are needed to improve the treatment results of VHL disease in Japan.

Surgical resection of medulla oblongata hemangioblastomas: outcome and complications

OBJECT

The purpose of this study was to analyze the surgical outcome and complications of a single-center series of medulla oblongata (MO) hemangioblastomas.

METHODS

We retrospectively reviewed the medical charts of all medulla oblongata hemangioblastomas operated on at our institution between 1996 and 2015. All patients had a pre- and postoperative MRI and a minimum follow-up of 6 months. Patients were scored according to the Karnofsky Performance Scale (KPS) and McCormick Scale at the moment of admission, discharge and the last follow-up.

RESULTS

Thirty-one surgical procedures were performed on 27 patients (16 females and 11 males). The mean age was 33 years, and 93 % of patients had von Hippel Lindau (VHL) disease. Three patients experienced very complicated postoperative courses, with one case ending in the death of the patient. Two patients required tracheostomy. According to McCormick's classification, 7 (23 %) of the 31 operations resulted in aggravation and 23 (74 %) in no change. Considering the seven patients with aggravation at discharge, four patients (60 %) returned to their preoperative status, one (14 %) improved but remained below his preoperative McCormick grade and two (29 %) did not improve. At last follow-up, KPS was ameliorated in 53 %, stable in 40 % and worsened in 7 % of cases.

CONCLUSION

Surgery of medulla oblongata hemangioblastomas is a challenging procedure characterized by an acceptable morbidity. Transient morbidity is not negligible even if the long-term outcome is in most cases favorable. A compromised neurological condition seems to be the best predictor of unfavorable outcome.

von Hippel-Lindau Disease: Review of Genetics and Imaging

von Hippel-Lindau (VHL) disease is an autosomal-dominant, hereditary, multisystem neoplasia syndrome with increased susceptibility to several benign and malignant tumors. VHL occurs in about 1 in 36,000 live births and is associated with germline mutation of the VHL tumor suppressor gene on the short arm of chromosome 3. VHL disease exhibits diverse genotype and phenotype correlations, exhibits variable intrafamilial and interfamilial expressivity, and can manifest with benign and malignant tumors of the central nervous system, kidneys, adrenals, pancreas, and reproductive organs. Imaging and management of this entity are therefore multidisciplinary. An overview of VHL disease is presented.

Stereotactic radiosurgery for intracranial hemangioblastomas: a retrospective international outcome study

OBJECT

The purpose of this study was to evaluate the role of stereotactic radiosurgery (SRS) in the management of intracranial hemangioblastomas.

METHODS

Six participating centers of the North American Gamma Knife Consortium and 13 Japanese Gamma Knife centers identified 186 patients with 517 hemangioblastomas who underwent SRS. Eighty patients had 335 hemangioblastomas associated with von Hippel–Lindau disease (VHL) and 106 patients had 182 sporadic hemangioblastomas. The median target volume was 0.2 cm3 (median diameter 7 mm) in patients with VHL and 0.7 cm3 (median diameter 11 mm) in those with sporadic hemangioblastoma. The median margin dose was 18 Gy in VHL patients and 15 Gy in those with sporadic hemangioblastomas.

RESULTS

At a median of 5 years (range 0.5–18 years) after treatment, 20 patients had died of intracranial disease progression and 9 patients had died of other causes. The overall survival after SRS was 94% at 3 years, 90% at 5 years, and 74% at 10 years. Factors associated with longer survival included younger age, absence of neurological symptoms, fewer tumors, and higher Karnofsky Performance Status. Thirty-three (41%) of the 80 patients with VHL developed new tumors and 17 (16%) of the106 patients with sporadic hemangioblastoma had recurrences of residual tumor from the original tumor. The 5-year rate of developing a new tumor was 43% for VHL patients, and the 5-year rate of developing a recurrence of residual tumor from the original tumor was 24% for sporadic hemangioblastoma patients. Factors associated with a reduced risk of developing a new tumor or recurrences of residual tumor from the original tumor included younger age, fewer tumors, and sporadic rather than VHL-associated hemangioblastomas. The local tumor control rate for treated tumors was 92% at 3 years, 89% at 5 years, and 79% at 10 years. Factors associated with an improved local tumor control rate included VHL-associated hemangioblastoma, solid tumor, smaller tumor volume, and higher margin dose. Thirteen patients (7%) developed adverse radiation effects (ARE) after SRS, and one of these patients died due to ARE.

CONCLUSIONS

When either sporadic or VHL-associated tumors were observed to grow on serial imaging studies, SRS provided tumor control in 79%–92% of tumors.

The incidence of second brain tumors related to cranial irradiation

Secondary brain tumor (SBT) is a devastating complication of cranial irradiation (CI). We reviewed the literature to determine the incidence of SBT as related to specific radiation therapy (RT) treatment modalities. The relative risk of radiation-associated SBT after conventional and conformal RT is well established and ranges from 5.65 to 10.9; latent time to develop second tumor ranges from 5.8 to 22.4 years, depending on radiation dose and primary disease. Theories and dosimetric models suggest that intensity-modulated radiation therapy may result in an increased risk of SBT, but clinical evidence is limited. The incidence of stereotactic radiosurgery-related SBT is low. Initial data suggest that no increased risk from proton therapy and dosimetric models predict a lower incidence of SBT compared with photons. In conclusion, the incidence of SBT related to CI is low. Longer follow-up is needed to clarify the impact of intensity-modulated radiation therapy, proton therapy and other developing technologies.

The clinical outcome of intracranial hemangioblastomas treated with linac-based stereotactic radiosurgery and radiotherapy

Recent publications have reported stereotactic radiosurgery as an effective and safe treatment for intracranial hemangioblastomas. However, because of the low incidence of these particular tumors, reports on large patient number studies have not yet been available. The objective of this study was to analyze the clinical results of 14 patients with 56 intracranial hemangioblastomas treated with linear accelerator (linac)-based stereotactic radiosurgery (SRS) and radiotherapy (SRT) in the same institute. The median age of patients was 41 years (range, 28-73 years). Nine of the patients (64%) had von Hippel-Lindau disease. A total of 39 lesions (70%) were treated with CyberKnife (CK), and 17 lesions (30%) were treated with X-Knife. The median pretreatment volume was 0.26 cm(3) (range, 0.026-20.4 cm(3)). The median marginal dose was 20 Gy (range, 10-32 Gy) in 1 fraction (range, 1-10 fractions). The median follow-up time was 24 months (range, 11-89 months). At the last follow-up, 47 tumors (84%) were stable, 7 (13%) decreased and 2 (4%) increased. The 1-, 2- and 6-year local control rates were 98%, 88% and 73%, respectively. No radiation complications were observed in this study. There was a trend toward local failure only in cystic tumors, but this trend was not found to be statistically significant. SRS/SRT achieved a high local control rate in intracranial hemangioblastomas without radiation-induced complications.

Familial syndromes associated with intracranial tumours: a review

BACKGROUND

Most cancers of the central nervous system (CNS) occur sporadically in the absence of any known underlying familial disorder or multi-systemic syndrome. Several syndromes are associated with CNS malignancies, however, and their recognition has significant implications for patient management and prognosis. Patients with syndrome-associated CNS malignancies often have multiple tumours (either confined to one region or distributed throughout the body), with similar or different histology.

OBJECTIVE

This review examines syndromes that are strongly associated with CNS cancers: the phakomatosis syndromes, familial syndromes such as Li-Fraumeni and familial polyposis syndromes and dyschondroplasia.

Operative management of brainstem hemangioblastomas

Brainstem hemangioblastomas are technically challenging lesions. The authors retrospectively analyzed their experience in 24 patients with brainstem hemangioblastomas to evaluate the management strategies used over time and the results of microsurgical treatment. All patients were operated on between 2007 and 2012. The patients received postoperative follow-up by neuroradiological and neurological examinations. The maximum diameter of the tumors ranged from 2.0 to 4.5 cm (mean 3.6 cm). Gross total resection was achieved in 24 patients (100%). Two patients (8%) had new neurological deficits or worsening of pre-existing deficits. One patient (4%) died because of brain stem dysfunction after the operation. Radical en bloc surgical resection of brainstem hemangioblastomas in symptomatic patients is a safe and effective primary treatment. Preoperative embolization is not necessary. It is very important and necessary to differentiate and dissect precisely at the interface of the tumor surface and the brainstem with a meticulous microsurgical technique until the tumor is removed en bloc. The preoperative neurological status of the patient predicts the postoperative functional outcome. Asymptomatic patients with hemangioblastoma may be followed clinically with MRI surveillance at regular intervals.

Supratentorial hemangioblastoma: clinical features, prognosis, and predictive value of location for von Hippel-Lindau disease

Supratentorial hemangioblastoma is a rare form of hemangioblastoma; little information is available regarding prognosis, treatment, and clinical characteristics, because the available literature is primarily composed of case reports and small case series. Therefore, we performed a systematic review of the literature to analyze clinical characteristics, disease progression, and surgical outcomes with respect to survival for supratentorial hemangioblastomas. The rate of progression-free survival (PFS) was determined using Kaplan-Meier analysis. Differences in categorical factors, including location of tumor and diagnosis of von Hippel-Lindau (VHL) disease, were analyzed using the Pearson χ(2) test. A total of 106 articles met the search criteria, which combined for a total of 132 patients. Of the patients with supratentorial tumors, 60% had VHL disease, and 31 (84%) of 37 patients with tumors in the sellar/suprasellar region had associated VHL (χ(2), P < .001). Five-year PFS for gross-total resection and subtotal resection were 100% and 53%, respectively (Log rank, P < .01). On the basis of our analysis of the literature on published cases of supratentorial hemangioblastoma, gross-total resection appears to be superior to other treatment modalities in extending PFS. Von Hippel-Lindau disease is positively correlated with supratentorial hemangioblastoma when compared with non-supratentorial CNS hemangioblastomas, particularly when present in the sellar/suprasellar region.

Neurosurgical considerations in von Hippel-Lindau disease

Von Hippel-Lindau disease is an inherited syndrome predisposing to a variety of benign and malignant neoplasms of the central nervous system and viscera that requires comprehensive screening and follow-up of individuals and their families. As such, it is important for the neurosurgeon to be aware of its clinical features and management issues. In this article we review the clinical aspects, management and surveillance of von Hippel-Lindau disease for neurosurgical practice.

Long-term outcome after resection of brainstem hemangioblastomas in von Hippel-Lindau disease

OBJECT

Brainstem hemangioblastomas are frequently encountered in patients with von Hippel-Lindau (VHL) disease. These tumors can cause significant morbidity, and their optimal management has not been defined. To better define the outcome and management of these tumors, the authors analyzed the long-term results in patients who underwent resection of brainstem hemangioblastomas.

METHODS

Consecutive patients with VHL disease who underwent resection of brainstem hemangioblastomas with a follow-up of 12 months or more were included in this study. Serial functional assessments, radiographic examinations, and operative records were analyzed.

RESULTS

Forty-four patients (17 male and 27 female) underwent 51 operations for resection of 71 brainstem hemangioblastomas. The most common presenting symptoms were headache, swallowing difficulties, singultus, gait difficulties, and sensory abnormalities. The mean follow-up was 5.9 ± 5.0 years (range 1.0-20.8 years). Immediately after 34 operations (66.7%), the patients remained at their preoperative functional status; they improved after 8 operations (15.7%) and worsened after 9 operations (17.6%) as measured by the McCormick scale. Eight (88.9%) of the 9 patients who were worse immediately after resection returned to their preoperative status within 6 months. Two patients experienced functional decline during long-term follow-up (beginning at 2.5 and 5 years postoperatively) caused by extensive VHL disease-associated CNS disease.

CONCLUSIONS

Generally, resection of symptomatic brainstem hemangioblastomas is a safe and effective management strategy in patients with VHL disease. Most patients maintain their preoperative functional status, although long-term decline in functional status may occur due to VHL disease-associated progression.

Clinical and surgical features of lower brain stem hemangioblastomas in von Hippel-Lindau disease

BACKGROUND

In the context of von Hippel-Lindau disease (VHL), the medulla oblongata is a relatively frequent site of growth of hemangioblastomas, posing related clinical and surgical difficulties. Their management requires a close correlation between clinical evolution and morphological surveillance. In order to describe their clinical and surgical features, we reviewed our experience in the treatment of these lesions.

METHODS

Between 2001 and 2009, 14 patients (9 female and 5 male, mean age 34 years) underwent removal of 15 lower brain stem hemangioblastomas. Based on the review of the clinical records and outpatient long-term follow-up visits, their clinical course was analyzed. Functional evaluation was measured with the Karnofsky Performance Scale (KPS) on admission, at discharge and at the last follow-up. The mean follow-up period was 30.8 months (range 4-99).

RESULTS

All the operated hemangioblastomas were located in the dorsal medulla oblongata, in the context of multiple lesions, cerebellar and/or spinal. In ten patients hemangioblastomas were located in a median position at the obex area; in four cases a lateral location was observed. Cystic component was absent in two cases. Clinical onset preceded surgery by a mean of 8.5 months. Preoperatively three patients showed a KPS lower than 80, ten patients between 80 and 90, and one patient scored 100 (asymptomatic). There was no surgical mortality. Nine out of 14 patients showed a temporary surgical morbidity. One patient required a tracheostomy. At follow-up ten patients scored a KPS better than before the operation, while the other four patients remained stable. Permanent morbidity was observed in three patients.

CONCLUSIONS

Lower brain stem hemangioblastomas in the context of VHL show an often gradual onset of signs and symptoms except for patients who develop an obstructive hydrocephalus. Although transient surgical complications are possible, surgery provides favorable long-term results.

Prospective evaluation of radiosurgery for hemangioblastomas in von Hippel-Lindau disease

To determine the effectiveness of stereotactic radiosurgery (SRS) treatment to central nervous system (CNS) hemangioblastomas in von Hippel-Lindau disease (VHL), we analyzed long-term results in VHL patients treated with SRS. Patients were enrolled in a prospective VHL natural history study, undergoing SRS treatment of CNS hemangioblastomas. Treatment regimens, serial clinical evaluations, and longitudinal imaging data were analyzed. Twenty VHL patients (10 males and 10 females) underwent SRS treatment of 44 CNS hemangioblastomas (39 cerebellar and 5 brainstem). Mean (+/-SD) age at treatment was 37.5 +/- 12.0 years (range: 13-67). Mean follow-up was 8.5 +/- 3.2 years (range: 3.0-17.6 years). All patients were alive at last follow-up. Mean treated tumor volume was 0.5 +/- 0.7 cm(3) (range: 0.01-3.6 cm(3)). Mean prescription dose was 18.9 Gy (range: 12-24 Gy) at the tumor margin. Local control rate at 2, 5, 10, and 15 years after SRS treatment was 91%, 83%, 61%, and 51%, respectively. Univariate analysis did not identify variables associated (P > .05) with worse tumor control at last follow-up. Thirty-three percent of SRS-treated small (<1.0 cm diameter), asymptomatic tumors progressed over a long-term follow-up. There were no long-term adverse radiation effects. Although SRS treatment of hemangioblastomas in VHL has a low risk for adverse radiation effects, it is associated with diminishing control over a long-term follow-up. These results indicate that SRS should not be used to prophylactically treat asymptomatic tumors and should be reserved for the treatment of tumors that are not surgically resectable.

Solid haemangioblastomas of the CNS: a review of 17 consecutive cases

A retrospective study on solid central nervous system haemangioblastomas was performed to characterize clinical features, treatment strategies and outcome in these rare lesions. Between 1993 and 2006 23, solid haemangioblastomas were surgically removed in 17 patients. Eight lesions were located within pons Varolii and medulla oblongata, six within the cerebellar hemispheres and three in the cerebellopontine angle. Three haemangioblastomas were located supratentorially and three within the spinal cord. All patients except two underwent pre-operative magnetic resonance imaging (MRI). Post-operative digital subtraction angiography and/or MRI was performed in all surviving patients. Except for spinal cord lesions, rather unsystematic clinical symptoms were observed. Twenty-two tumours could be resected completely. Two patients with brainstem lesions died within 10 weeks after surgery from infectious complications. Persistent new neurological deficits occurred in two patients. Three patients underwent radiosurgery prior to or following the surgical procedure. Solid haemangioblastomas represent a surgical challenge due to their arteriovenous malformation-like vascularisation and their frequent location in eloquent areas. Surgery is the therapy of choice. Circumferential dissection with devascularization and en bloc removal yields good functional results. A location within the brainstem carries the most unfavourable prognosis.

The Department of Neurosurgery at Shanghai Huashan Hospital

The Department of Neurosurgery at Shanghai HuaShan Hospital is one of the oldest neurosurgical departments in China and is also one of the country's leading academic neurosurgery programs. The department was established in 1953 under the direction of Yuquan Shi, one of the pioneers and founders of neurosurgery in China, and is currently directed by Liang-Fu Zhou. The HuaShan Neurosurgical Group Hospital and the Shanghai HuaShan Institution of Neurosurgery were established in 2000. The department currently has 67 faculty and 450 beds distributed among one main hospital (HuaShan Hospital) and seven affiliates. More than 8000 neurosurgical procedures are performed annually. The Shanghai Emergency Center of Neurosurgery is also maintained by the department. The Department of Neurosurgery at HuaShan Hospital will continue to grow in strength and position as one of the leaders in the field of neurosurgery.

Gamma knife radiosurgery for intracranial haemangioblastomas

BACKGROUND

The results of gamma knife radiosurgery for haemangioblastomas were retrospectively studied to assess the efficacy for tumour growth control and clarify the clinical indications for gamma knife radiosurgery in these tumours.

METHODS

The medical records of 22 patients with 67 tumours, 12 men and 10 women aged 20-73 years (mean 51.9 years), who underwent gamma knife radiosurgery for haemangioblastomas between January 1993 and January 2006, were retrospectively reviewed. Ten patients with 54 lesions had von Hippel-Lindau disease. The mean tumour volume was 1.69 cm(3) (range 0.0097-16.4 cm(3)). Nineteen patients had undergone 1-4 open surgery procedures (mean 1.5) before gamma knife radiosurgery. Tumours without a cystic component, (the solid type), were found in 54 lesions and tumours associated with cyst, (the mural nodule with cyst type), in 13 lesions. The marginal dose was 8-30 Gy (mean 14.0 Gy).

FINDINGS

Follow-up magnetic resonance (MR) imaging was performed at 9-146 months (mean 63 months). The control rate for tumour growth was 83.6%. The only factor affecting tumour growth control was the presence of a cystic component at the time of gamma knife radiosurgery in both univariate and multivariate analysis. No complication such as radiation-induced peritumoural oedema or radiation necrosis occurred.

CONCLUSION

The presence of cystic components at the time of gamma knife radiosurgery was the only factor significantly correlated with unfavourable tumour growth control by gamma knife radiosurgery for haemangioblastomas. Gamma knife radiosurgery is effective for solid type tumours, even if the marginal dose is relatively low. Surgical removal is recommended for mural nodule with cyst type tumours, when possible.

Role of fractionated external beam radiotherapy in hemangioblastoma of the central nervous system

PURPOSE

To assess the clinical outcomes and toxicity in patients receiving fractionated external beam radiotherapy (EBRT) for hemangioblastoma of the central nervous system, treated at two Canadian radiation oncology institutions.

METHODS AND MATERIALS

Between January 1980 and December 2004, the data of all patients receiving EBRT for central nervous system hemangioblastoma were retrospectively reviewed. The patient, tumor, and treatment characteristics were collected and overall survival, disease-free survival, and EBRT-related toxicities assessed.

RESULTS

A total of 18 cases, 5 associated with von Hippel-Lindau disease (VHL) and 13 sporadic (non-VHL), with a total 31 lesions, were documented. These were located in the cerebellum in 20 and spinal cord in 8 patients. EBRT was delivered for recurrence in 12, adjuvantly for residual disease in 4, and definitively in 2. The EBRT schedules ranged from 50.0 to 55.8 Gy in 1.8-2.0-Gy daily fractions (n = 17), typically with parallel-opposed fields to the cerebellar target volumes and direct posterior fields for spinal disease. At a median follow-up of 5.1 years (range, 0.1-14.5), the 5-year OS rate was 69% (95% confidence interval [CI], 50-96%), decreasing to 30% (95% CI, 10-87%) at 10 years. The disease-free survival rate at 5 and 10 years was 57% (95% CI, 37-87%) and 30% (95% CI, 11-83%), respectively. The outcomes differed according to VHL status. The 5-year OS rate was 100% for those with VHL compared with 55% (95% CI, 32-95%) for those with non-VHL disease (log-rank p = 0.003), and the 5-year disease-free survival rate was 80% (95% CI, 52-100%) with VHL compared with 48% (95% CI, 26-89%) without (log-rank p = 0.036).

CONCLUSIONS

Fractionated EBRT has a role in the management of extensive intracranial and/or spinal cord disease, the adjuvant treatment of residual postoperative disease, and the treatment of recurrence. More favorable outcomes were reported for VHL-associated lesions than for sporadic cases.

Role of edema in peritumoral cyst formation

✓Peritumoral cysts (those arising immediately adjacent to the tumor mass) are frequently associated with benign and malignant tumors of the brain and spinal cord (syringomyelia). The cystic component of central nervous system (CNS) tumors and associated peritumoral cysts are often the cause of clinical symptoms. Because of the common occurrence of peritumoral cysts with CNS neoplasms and the morbidity associated with them, advanced imaging, histological, and molecular techniques have been used to determine the mechanism underlying cyst formation and propagation. Based on evidence from such studies, edema appears to be a common precursor to peritumoral cyst formation in the CNS. Mediators of vascular permeability acting locally in the tumor and/or hydrodynamic forces within abnormal tumor vascula-ture appear to drive fluid extravasation. When these forces overcome the ability of surrounding tissue to resorb fluid, edema and subsequent cyst formation occur. These findings support the concept that the tumor itself is the source of the edema that precedes cyst formation and that resection of tumors or medical therapies directed at decreasing their vascular permeability will result in the resolution of edema and cysts.

Pituitary stalk hemangioblastoma: The fourth case report and review of the literature

Supratentorial hemangioblastomas (HBL) have been rarely described in the literature. Herein we report the fourth case of pituitary stalk HBL diagnosed concurrently with cerebellar HBLs in a 51-year-old woman with von Hippel-Lindau disease. Complete resection of the lesion was achieved using left frontopterional craniotomy and no recurrence was observed after 8 years of follow-up. The clinical presentation, radiological features, pathological findings, and the management of this particular case are discussed in the light of the available literature. To our knowledge, this case is the only pituitary stalk HBL with total resection, and a long follow-up fully documented.

Disseminated haemangioblastoma without evidence of the von Hippel-Lindau syndrome or haemangioblastomatosis--A case report and clinico-pathological correlation

A 71-year-old Caucasian female presented to our service with disseminated cranial and spinal haemangioblastomata but no other features to suggest the von Hippel-Lindau syndrome. We feel that this represents cellular dissemination through the cerebro-spinal fluid and may be an intermediate step to the development of frank haemangioblastomatosis. By comparing this presentation to that of other tumours we have suggested a potential pathological mechanism and have discussed its management.

Less Common Indications for Stereotactic Radiosurgery or Fractionated Radiotherapy for Patients with Benign Brain Tumors

Microsurgical resection remains the mainstay of treatment for truly benign brain tumors that can be safely resected because of the potential for permanent cure with most histologic findings, including most of the histologic findings discussed in this article. Physicians must keep in mind the indolent nature of many of the benign brain tumors and realize that many patients are likely to live out normal life spans if tumor control is achieved. Therefore, it is not sufficient simply to consider local tumor control rates and short-term toxicity risks when choosing between surgery, stereotactic radiosurgery, and fractionated radiotherapy. Patients need to be apprised of all therapeutic options and to make their decisions with all information required to evaluate the risks and benefits. For benign brain tumors, these decisions may have consequences that last for decades.