Nervous System Hemangiopericytoma.

The management of patients harboring central nervous system (CNS) hemangiopericytomas (HPCs) is a partially answered challenge. These are rare locally aggressive lesions, with potential for local recurrence, distal neural metastasis (DNM), and extraneural metastasis (ENM). Resection, when feasible, remains the initial treatment option, providing histological diagnosis and immediate relief of tumor-related mass effect. Patients receiving surgery alone or surgery and external beam radiotherapy (EBRT) show improved overall survival (OS) and progression-free survival as compared to those undergoing a biopsy alone (p = 0.01 and p = 0.02, respectively). Yet, in many instances, patient and tumor-related parameters preclude complete resection. EBRT or stereotactic radiosurgery (SRS) shares a significant role in achieving local tumor control, not shown to impact OS in HPC patients. The benefits of SRS/EBRT are clearly limited to improved local tumor volume control and neurologic function, not affecting DNM or ENM development. SRS provides acceptable rates of local tumor volume control coupled with treatment safety and a patient-friendly apparatus and procedure. Single-session SRS is most effective for lesions measuring <2 cm in their largest diameter (10 cm3 volume), with prescription doses of at >15 Gy. Systemic HPC disease is managed with various chemotherapeutic, immunotherapeutic, and anti-angiographic agents, with limited success. We present a short discussion on CNS HPCs, focusing our discussion on available evidence regarding the role of microsurgical resection, EBRT, SRS, chemotherapy, and immunotherapy for upfront, part of adoptive hybrid surgery approach or for recurrent HPCs.

L'hémangiopéricytome du système nerveux central. La prise en charge des patients atteints d'un hémangiopéricytome du système nerveux central demeure un défi auquel on n'a pas tout à fait encore répondu. Il s'agit en effet de lésions fulminantes qui présentent un potentiel de récurrence locale mais aussi d'apparition de métastases affectant la partie distale des neurones et de métastases hors neurones. Lorsque cela est possible, la résection constitue la première option thérapeutique. Cette dernière permet d'assurer un diagnostic histologique ainsi qu'un soulagement immédiat de l'effet de masse associé à la tumeur cérébrale. Les patients bénéficiant uniquement d'une intervention chirurgicale ou d'une intervention combinant la chirurgie et la radiothérapie ont montré une amélioration de leur taux de survie globale et de leur taux de survie sans aggravation si on les compare aux autres patients soumis à une seule biopsie (respectivement p = 0,01 et p = 0,02). Dans bien des cas, il est des paramètres se rapportant aux patients et aux tumeurs elles-mêmes qui excluent une résection complète. À cet égard, rappelons qu'une intervention combinant chirurgie et radiothérapie ou bien encore la radiochirurgie stéréotaxique peuvent jouer un rôle clé dans le contrôle d'une tumeur locale, et ce, sans que le taux de survie globale des patients atteints d'un hémangiopéricytome soit affecté. Cela dit, les bénéfices de la radiochirurgie stéréotaxique et d'une intervention combinant chirurgie et radiothérapie demeurent clairement limités à une amélioration du contrôle des tumeurs locales et des fonctions neurologiques et n'ont pas d'impact sur le développement des métastases affectant la partie distale des neurones et des métastases hors neurones. Ajoutons aussi que la radiochirurgie stéréotaxique offre des taux de contrôle des tumeurs locales acceptables en plus de représenter un traitement sécuritaire pour les patients et de sous-tendre l'utilisation de procédures et d'équipements conviviaux. Une simple séance de radiochirurgie stéréotaxique sera particulièrement indiquée dans le cas de lésions mesurant moins de 2 cm dans leur plus grand diamètre (volume de 10 cm3), les doses prescrites étant de >15 Gy. Un hémangiopéricytome de caractère systémique pourra être traité avec un succès limité au moyen de nombreux agents chimiothérapeutiques, immunothérapeutiques et anti-angiographiques. Nous voulons donc faire ici un bref exposé au sujet des hémangiopéricytomes du système nerveux central. Nous voulons aussi mettre l'accent sur les preuves disponibles concernant l'impact de la résection microchirurgicale, des interventions combinant chirurgie et radiothérapie, de la radiochirurgie stéréotaxique, de la chimiothérapie et de l'immunothérapie dans le cadre d'une approche chirurgicale hybride initiale pour des cas récurrents d'hémangiopéricytomes.

Geriatric brain tumor management part I: Meningioma.

Life expectancy continues to rise exponentially. The concept of frailty has emerged as a tool helping to gauge overall health status and risk of adverse events in aging patients, has shown to exhibit a linear relationship with poor survival in the elderly. Multiple pathologies have different genetic, radiographic, clinical and prognostic characteristics in the elderly, responding differently to various treatment modalities and thus present as unique clinical entities, not properly represented in large - guidelines generating studies. We present a two parts review discussing the unique features of the elderly patient harboring an intracranial neoplasm. In this Part-I, we review the management of benign meningioma in the elderly population. Meningioma is the second most common primary brain tumor. The risk of developing meningioma increases dramatically after 65 years of age. Predicting a specific meningioma's growth pattern and clinical behavior is impossible. Clinicians must choose between GTR with associated morbidity/ mortality, SRS or a combined AHS approach, since progression rates after STR are high. Several scoring systems attempt to offer risk stratification in meningiomas (five systems presented). The most comprehensive and validated GSS (for both resection and SRS) offers the opportunity for intervention, with potentially modifiable parameters.

Geriatric brain tumor management part II: Glioblastoma multiforme.

The elderly (≥60 years) population increases rapidly, at a projected 2.9%/year increments by year 2050. The concept of Frailty can be outlined using one of two models, the phenotypic or deficit based models, serving as a clinical tool to measure the overall health and risk of adverse events. There is a linear correlation between frailty and poor survival in the elderly. Different pathological entities behave differently in the geriatric population and respond differently to standard treatment, which merits a specific focused discussion and research. We present a two parts review discussing the unique features of the elderly patient harboring an intracranial neoplasm. In this Part-II, we review the management of Glioblastoma-Multiforme (GBM) in the elderly population. GBM is the most common primary brain tumour in adults. The number of elderly patients with GBM is expected to double in the next 2 decades. Age serves as both a negative prognosticator and a risk factor for GBM. The reported OS for newly diagnosed GBM is 15 months, yet it is worse for elderly GBM patients, which seem to feature a relentless course with progressive and rapid loss of neurologic function and resistance to treatment. In spite of accumulating evidence, the optimal management of elderly patients with GBM is still controversial, driven by concern that any treatment may be less effective and more toxic in the elderly. Treatment decisions should be made in the context of a comprehensive geriatric assessment.

Treatment of Asymptomatic Meningioma With Gamma Knife Radiosurgery: Long-Term Follow-up With Volumetric Assessment and Clinical Outcome.

BACKGROUND: Some patients are diagnosed with asymptomatic meningioma(s) after undergoing a screening CT and MRI for minor ailments or postresection. OBJECTIVE: To help clinicians in decision making for treatment of asymptomatic meningiomas. METHODS: A single center retrospective cohort study of 117 patients with 122 tumors treated with Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden). Patients were followed with longitudinal imaging and clinical evaluations. Tumor volumetry and developments of new signs or symptoms after GKRS were the end points in the study. RESULTS: Median patient age at GKRS was 60 yr (range 21-86 yr) with a median clinical follow-up of 53 mo (range 20-252 mo). The median pre-GKRS tumor volume was 3.6 ± 3.8 cc (±standard deviation). Tumors were treated with a median margin dose of 14 ± 2 Gy. At last follow-up, median tumor volume was 2.5 ± 3.6 cc. Radiological progression-free survival (PFS) rates were 97% and 94.4% at 5 yr and 10 yr, respectively. Clinical PFS rates were 86% and 70% at 5 yr and 10 yr, respectively. Development of neurological complications was seen in 21 (18%) patients, and 11 (52%) of them had undergone surgical resection prior to GKRS. CONCLUSION: GKRS is a reasonable treatment strategy for asymptomatic meningiomas and compares favorably to natural history studies in terms of tumor control and neurological preservation. It results in relatively low morbidity in previously untreated meningiomas and serves as an appealing alternative treatment modality for recurrent meningiomas in asymptomatic patients.

Radiation dose to neuroanatomical structures of pituitary adenomas and the effect of Gamma Knife radiosurgery on pituitary function.

OBJECTIVE: Gamma Knife radiosurgery (GKRS) provides a safe and effective management option for patients with all types of pituitary adenomas. The long-term adverse effects of targeted radiation to the hypothalamic-pituitary axis in relationship to radiation dose remain unclear. In this retrospective review, the authors investigated the role of differential radiation doses in predicting long-term clinical outcomes and pituitary function after GKRS for pituitary adenomas. METHODS: A cohort of 236 patients with pituitary tumors (41.5% nonfunctioning, 58.5% functioning adenomas) was treated with GKRS between 1998 and 2015. Point dosimetric measurements, with no minimum volume, to 14 consistent points along the hypothalamus bilaterally, pituitary stalk, and normal pituitary were made. Statistical analyses were performed to determine the impact of doses to critical structures on clinical, radiological, and endocrine outcomes. RESULTS: With a median follow-up duration of 42.9 months, 18.6% of patients developed new loss of pituitary function. The median time to endocrinopathy was 21 months (range 2-157 months). The median dose was 2.1 Gy to the hypothalamus, 9.1 Gy to the pituitary stalk, and 15.3 Gy to the normal pituitary. Increasing age (p = 0.015, HR 0.98) and ratio of maximum dose to the pituitary stalk over the normal pituitary gland (p = 0.013, HR 0.22) were independent predictors of new or worsening hypopituitarism in the multivariate analysis. Sex, margin dose, treatment volume, nonfunctioning adenoma status, or ratio between doses to the pituitary stalk and hypothalamus were not significant predictors. CONCLUSIONS: GKRS offers a low rate of delayed pituitary insufficiency for pituitary adenomas. Doses to the hypothalamus are low and generally do not portend endocrine deficits. Patients who are treated with a high dose to the pituitary stalk relative to the normal gland are at higher risk of post-GKRS endocrinopathy. Point dosimetry to specific neuroanatomical structures revealed that a ratio of stalk-to-gland radiation dose of 0.8 or more significantly increased the risk of endocrinopathy following GKRS. Improvement in the gradient index toward the stalk and normal gland may help preserve endocrine function.

Stereotactic Radiosurgery for Intracranial Ependymomas: An International Multicenter Study.

BACKGROUND: Stereotactic radiosurgery (SRS) is a potentially important option for intracranial ependymoma patients. OBJECTIVE: To analyze the outcomes of intracranial ependymoma patients who underwent SRS as a part of multimodality management. METHODS: Seven centers participating in the International Gamma Knife Research Foundation identified 89 intracranial ependymoma patients who underwent SRS (113 tumors). The median patient age was 16.3 yr (2.9-80). All patients underwent previous surgical resection and radiation therapy (RT) of their ependymomas and 40 underwent previous chemotherapy. Grade 2 ependymomas were present in 42 patients (52 tumors) and grade 3 ependymomas in 48 patients (61 tumors). The median tumor volume was 2.2 cc (0.03-36.8) and the median margin dose was 15 Gy (9-24). RESULTS: Forty-seven (53%) patients were alive and 42 (47%) patients died at the last follow-up. The overall survival after SRS was 86% at 1 yr, 50% at 3 yr, and 44% at 5 yr. Smaller total tumor volume was associated with longer overall survival (P = .006). Twenty-two patients (grade 2: n = 9, grade 3: n = 13) developed additional recurrent ependymomas in the craniospinal axis. The progression-free survival after SRS was 71% at 1 yr, 56% at 3 yr, and 48% at 5 yr. Adult age, female sex, and smaller tumor volume indicated significantly better progression-free survival. Symptomatic adverse radiation effects were seen in 7 patients (8%). CONCLUSION: SRS provides another management option for residual or recurrent progressive intracranial ependymoma patients who have failed initial surgery and RT.

Repeat Stereotactic Radiosurgery for Progressive or Recurrent Vestibular Schwannomas.

BACKGROUND: Stereotactic radiosurgery (SRS) is a highly effective management approach for patients with vestibular schwannomas (VS), with 10-yr control rates up 98%. When it fails, however, few data are available to guide management. OBJECTIVE: To perform a retrospective analysis of patients who underwent 2 SRS procedures on the same VS to assess the safety and efficacy of this practice. METHODS: This study was opened to centers of the International Gamma Knife Research Foundation (IGKRF). Data collected included patient characteristics, clinical symptoms at the time of SRS, radiosurgery dosimetric data, imaging response, clinical evolution, and survival. Actuarial analyses of tumor responses were performed. RESULTS: Seventy-six patients from 8 IGKRF centers were identified. Median follow-up from the second SRS was 51.7 mo. Progression after the first SRS occurred at a median of 43 mo. Repeat SRS was performed using a median dose of 12 Gy. Actuarial tumor control rates at 2, 5, and 10 yr following the second SRS were 98.6%, 92.2%, and 92.2%, respectively. Useful hearing was present in 30%, 8%, and 5% of patients at first SRS, second SRS, and last follow-up, respectively. Seventy-five percent of patients reported stable or improved symptoms following the second SRS. Worsening of facial nerve function attributable to SRS occurred in 7% of cases. There were no reports of radionecrosis, radiation-associated edema requiring corticosteroids, radiation-related neoplasia, or death attributable to the repeat SRS procedure. CONCLUSION: Patients with progressing VS after radiosurgery can be safely and effectively managed using a second SRS procedure.

Adaptive Hybrid Surgery: Paradigm Shift for Patient-centered Neurosurgery.

The surgical management of cerebral and skull base lesions has evolved greatly in the last few decades. Still, a complete resection of lesions abutting critical neurovascular structures carries significant morbidity. Stereotactic radiosurgery (SRS) has emerged as an increasingly accepted treatment option. Minimally invasive, SRS results in excellent tumor control and low complication rates in patients with moderate-size tumors. The management of large cerebral and skull base tumors remains a formidable challenge. In such large tumors, radical surgical extirpation offers a significantly higher risk of neurological deficit, and SRS alone cannot be used because of the elevated incidence of radiation-induced complications known to be associated with large-volume tumors. With increasing treatment volumes, SRS-associated tumor control rates decrease and complication rates increase. Planned subtotal resection (STR) with adjuvant SRS (adaptive hybrid surgery [AHS]) has gained increasing interest in recent years as a multimodal approach. In AHS, a planned STR (aimed at decreasing surgical morbidity) followed by SRS to a preplanned residual tumor aids in harnessing advantages offered by both approaches. Although intuitive and reasonable, this paradigm shift from maximal resection at all cost has not been adopted widely. Combining open microsurgery with SRS requires a good understanding of both surgical and SRS modalities and their respective safety-efficacy features. We present a review and discussion on AHS as a modern, multidisciplinary treatment approach. Available data and views are discussed for vestibular schwannoma (VS) as a sample tumor. Other indications for AHS are mentioned in brief.

Stereotactic radiosurgery in the treatment of parasellar meningiomas: long-term volumetric evaluation.

OBJECTIVE Parasellar meningiomas tend to invade the suprasellar, cavernous sinus, and petroclival regions, encroaching on adjacent neurovascular structures. As such, they prove difficult to safely and completely resect. Stereotactic radiosurgery (SRS) has played a central role in the treatment of parasellar meningiomas. Evaluation of tumor control rates at this location using simplified single-dimension measurements may prove misleading. The authors report the influence of SRS treatment parameters and the timing and volumetric changes of benign WHO Grade I parasellar meningiomas after SRS on long-term outcome. METHODS Patients with WHO Grade I parasellar meningiomas treated with single-session SRS and a minimum of 6 months of follow-up were selected. A total of 189 patients (22.2% males, n = 42) form the cohort. The median patient age was 54 years (range 19-88 years). SRS was performed as a primary upfront treatment for 44.4% (n = 84) of patients. Most (41.8%, n = 79) patients had undergone 1 resection prior to SRS. The median tumor volume at the time of SRS was 5.6 cm3 (0.2-54.8 cm3). The median margin dose was 14 Gy (range 5-35 Gy). The volumes of the parasellar meningioma were determined on follow-up scans, computed by segmenting the meningioma on a slice-by-slice basis with numerical integration using the trapezoidal rule. RESULTS The median follow-up was 71 months (range 6-298 months). Tumor volume control was achieved in 91.5% (n = 173). Tumor progression was documented in 8.5% (n = 16), equally divided among infield recurrences (4.2%, n = 8) and out-of-field recurrences (4.2%, n = 8). Post-SRS, new or worsening CN deficits were observed in 54 instances, of which 19 involved trigeminal nerve dysfunction and were 18 related to optic nerve dysfunction. Of these, 90.7% (n = 49) were due to tumor progression and only 9.3% (n = 5) were attributable to SRS. Overall, this translates to a 2.64% (n = 5/189) incidence of direct SRS-related complications. These patients were treated with repeat SRS (6.3%, n = 12), repeat resection (2.1%, n = 4), or both (3.2%, n = 6). For patients treated with a margin dose ≥ 16 Gy, the 2-, 4-, 6-, 8-, 10-, 12-, and 15-year actuarial progression-free survival rates are 100%, 100%, 95.7%, 95.7%, 95.7%, 95.7%, and 95.7%, respectively. Patients treated with a margin dose < 16 Gy, had 2-, 4-, 6-, 8-, 10-, 12-, and 15-year actuarial progression-free survival rates of 99.4%, 97.7%, 95.1%, 88.1%, 82.1%, 79.4%, and 79.4%, respectively. This difference was deemed statistically significant (p = 0.043). Reviewing the volumetric patient-specific measurements, the early follow-up volumetric measurements (at the 3-year follow-up) reliably predicted long-term volume changes and tumor volume control (at the 10-year follow-up) (p = 0.029). CONCLUSIONS SRS is a durable and minimally invasive treatment modality for benign parasellar meningiomas. SRS offers high rates of growth control with a low incidence of neurological deficits compared with other treatment modalities for meningiomas in this region. Volumetric regression or stability during short-term follow-up of 3 years after SRS was shown to be predictive of long-term tumor control.

Volume-staged versus dose-staged stereotactic radiosurgery outcomes for large brain arteriovenous malformations: a systematic review.

OBJECTIVE Several recent studies have improved our understanding of the outcomes of volume-staged (VS) and dose-staged (DS) stereotactic radiosurgery (SRS) for the treatment of large (volume > 10 cm3) brain arteriovenous malformations (AVMs). In light of these recent additions to the literature, the aim of this systematic review is to provide an updated comparison of VS-SRS and DS-SRS for large AVMs. METHODS A systematic review of the literature was performed using PubMed to identify cohorts of 5 or more patients with large AVMs who had been treated with VS-SRS or DS-SRS. Baseline data and post-SRS outcomes were extracted for analysis. RESULTS A total of 11 VS-SRS and 10 DS-SRS studies comprising 299 and 219 eligible patients, respectively, were included for analysis. The mean obliteration rates for VS-SRS and DS-SRS were 41.2% (95% CI 31.4%-50.9%) and 32.3% (95% CI 15.9%-48.8%), respectively. Based on pooled individual patient data, the outcomes for patients treated with VS-SRS were obliteration in 40.3% (110/273), symptomatic radiation-induced changes (RICs) in 13.7% (44/322), post-SRS hemorrhage in 19.5% (50/256), and death in 7.4% (24/323); whereas the outcomes for patients treated with DS-SRS were obliteration in 32.7% (72/220), symptomatic RICs in 12.2% (31/254), post-SRS hemorrhage in 10.6% (30/282), and death in 4.6% (13/281). CONCLUSIONS Volume-staged SRS appears to afford higher obliteration rates than those achieved with DS-SRS, although with a less favorable complication profile. Therefore, VS-SRS or DS-SRS may be a reasonable treatment approach for large AVMs, either as stand-alone therapy or as a component of a multimodality management strategy.

Stereotactic radiosurgery for jugular foramen schwannomas: an international multicenter study.

OBJECTIVE: For some jugular foramen schwannomas (JFSs), complete resection is possible but may be associated with significant morbidity. Stereotactic radiosurgery (SRS) is a minimally invasive alternative or adjunct to microsurgery for JFSs. The authors reviewed clinical and imaging outcomes of SRS for patients with these tumors. METHODS: Nine participating centers of the International Gamma Knife Research Foundation identified 92 patients who underwent SRS between 1990 and 2013. Forty-one patients had prior subtotal microsurgical resection. The median interval between previous surgery and SRS was 15 months (range 0.5-144 months). Eighty-four patients had preexisting cranial nerve (CN) symptoms and signs. The median tumor volume was 4.1 cm3 (range 0.8-22.6 cm3), and the median margin dose was 12.5 Gy (range 10-18 Gy). Patients with neurofibromatosis were excluded from this study. RESULTS: The median follow-up was 51 months (range 6-266 months). Tumors regressed in 47 patients, remained stable in 33, and progressed in 12. The progression-free survival (PFS) was 93% at 3 years, 87% at 5 years, and 82% at 10 years. In the entire series, only a dumbbell shape (extension extracranially via the jugular foramen) was significantly associated with worse PFS. In the group of patients without prior microsurgery (n = 51), factors associated with better PFS included tumor volume < 6 cm3 (p = 0.037) and non-dumbbell-shaped tumors (p = 0.015). Preexisting cranial neuropathies improved in 27 patients, remained stable in 51, and worsened in 14. The CN function improved after SRS in 12% of patients at 1 year, 24% at 2 years, 27% at 3 years, and 32% at 5 years. Symptomatic adverse radiation effects occurred in 7 patients at a median of 7 months after SRS (range 5-38 months). Six patients underwent repeat SRS at a median of 64 months (range 44-134 months). Four patients underwent resection at a median of 14 months after SRS (range 8-30 months). CONCLUSIONS: Stereotactic radiosurgery proved to be a safe and effective primary or adjuvant management approach for JFSs. Long-term tumor control rates and stability or improvement in CN function were confirmed.

Prognostic significance of corticotroph staining in radiosurgery for non-functioning pituitary adenomas: a multicenter study.

Silent corticotroph staining pituitary adenoma (SCA) represents an uncommon subset of Non-Functioning adenomas (NFAs), hypothesized to be more locally aggressive. In this retrospective multicenter study, we investigate the safety and effectiveness of Stereotactic Radiosurgery (SRS) in patients with SCA compared with other non-SCA NFA's. Eight centers participating in the International Gamma-Knife Research Foundation (IGKRF) contributed to this study. Outcomes of 50 patients with confirmed SCAs and 307 patients with confirmed non-SCA NFA's treated with SRS were evaluated. Groups were matched. SCA was characterized by a lack of clinical evidence of Cushing disease, yet with positive immunostaining for corticotroph. Median age was 55.2 years (13.7-87). All patients underwent at least one trans-sphenoidal tumor resection prior to SRS. SRS parameters were comparable as well. Median follow-up 40 months (6-163). Overall tumor control rate (TCR) 91.2% (n = 280). In the SCA group, TCR were 82% (n = 41) versus 94.1% (n = 289) for the control-NFA (p = 0.0065). The SCA group showed a significantly higher incidence of new post-SRS visual deficit (p < 0.0001) assigned to tumor progression and growth, and post-SRS weakness and fatigue (p < 0.0001). In univariate and multivariate analysis, only the status of silent corticotroph staining (p = 0.005, p = 0.009 respectively) and margin dose (p < 0.0005, p = 0.0037 respectively) significantly influenced progression rate. A margin dose of ≥17 Gy was noted to influence the adenoma progression rate in the entire cohort (p = 0.003). Silent corticotroph staining represents an independent factor for adenoma progression and hypopituitarism after SRS. A higher margin dose may convey a greater chance of TCR.

Histology-Stratified Tumor Control and Patient Survival After Stereotactic Radiosurgery for Pineal Region Tumors: A Report From the International Gamma Knife Research Foundation.

BACKGROUND: Pineal region tumors represent a rare and histologically diverse group of lesions. Few studies are available to guide management and the outcomes after stereotactic radiosurgery (SRS). METHODS: Patients who underwent SRS for a pineal region tumor and for whom at least 6 months of imaging follow-up was available were retrospectively assessed in 5 centers. Data were collected from the medical record and histology level analyses were performed, including actuarial tumor control and survival analyses. RESULTS: A total of 70 patients were treated between 1989 and 2014 with a median follow-up of 47 months. Diagnoses were pineocytoma (37%), pineoblastoma (19%), pineal parenchymal tumor of intermediate differentiation (10%), papillary tumor of the pineal region (9%), germinoma (7%), teratoma (3%), embryonal carcinoma (1%), and unknown (14%). Median prescription dose was 15 Gy at the 50% isodose line. Actuarial local control and survival rates were 81% and 76% at 20 years for pineocytoma, 50% and 56% at 5 years for pineal parenchymal tumor of intermediate differentiation, 27% and 48% at 5 years for pineoblastoma, 33% and 100% at 5 years for papillary tumor of the pineal region, 80% and 80% at 20 years for germinoma, and 61% and 67% at 5 years for tumors of unknown histology. New focal neurological deficit, Parinaud syndrome, and hydrocephalus occurred in 9%, 7%, and 3% of cases, respectively. CONCLUSIONS: SRS is a safe modality for the management of pineal region tumors. Its specific role is highly dependent on tumor histology. As such, all efforts should be made to obtain a reliable histologic diagnosis.

Stereotactic radiosurgery for small brain metastases and implications regarding management with systemic therapy alone.

While stereotactic radiosurgery (SRS) has been shown effective in the management of brain metastases, small brain metastases (≤10 mm) can pose unique challenges. Our aim was to investigate the efficacy of SRS in the treatment of small brain metastases, as well as elucidate clinically relevant factors impacting local failure (LF). We utilized a large, single-institution cohort to perform a retrospective analysis of patients with brain metastases up to 1 cm in maximal dimension. Clinical and radiosurgical parameters were investigated for an association with LF and compared using a competing risk model to calculate cumulative incidence functions, with death and whole brain radiotherapy serving as competing risks. 1596 small brain metastases treated with SRS among 424 patients were included. Among these tumors, 33 developed LF during the follow-up period (2.4% at 12 months following SRS). Competing risk analysis demonstrated that LF was dependent on tumor size (0.7% if ≤2 mm and 3.0% if 2-10 mm at 12 months, p = 0.016). Other factors associated with increasing risk of LF were the decreasing margin dose, increasing maximal tumor diameter, volume, and radioresistant tumors (each p < 0.01). 22 tumors (0.78%) developed radiographic radiation necrosis following SRS, and this incidence did not differ by tumor size (≤2 mm and 2-10 mm, p = 0.200). This large analysis confirms that SRS remains an effective modality in treatment of small brain metastases. In light of the excellent local control and relatively low risk of toxicity, patients with small brain metastases who otherwise have a reasonable expected survival should be considered for radiosurgical management.

Stereotactic Radiosurgery for Brainstem Arteriovenous Malformations: A Multicenter Study.

BACKGROUND: The management of brainstem arteriovenous malformations (bAVMs) is a formidable challenge. bAVMs harbor higher morbidity and mortality compared to other locations. OBJECTIVE: To review the outcomes following stereotactic radiosurgery (SRS) of bAVMs in a multicenter study. METHODS: Six medical centers contributed data from 205 patients through the International Gamma Knife Research Foundation. Median age was 32 yr (6-81). Median nidus volume was 1.4 mL (0.1-69 mL). Favorable outcome (FO) was defined as AVM obliteration and no post-treatment hemorrhage or permanent symptomatic radiation-induced complications. RESULTS: Overall obliteration was reported in 65.4% (n = 134) at a mean follow-up of 69 mo. Obliteration was angiographically proven in 53.2% (n = 109) and on MRA in 12.2% (n = 25). Actuarial rate of obliteration at 2, 3, 5, 7, and 10 yr after SRS was 24.5%, 43.3%, 62.3%, 73%, and 81.8% respectively. Patients treated with a margin dose >20 Gy were more likely to achieve obliteration (P = .001). Obliteration occurred earlier in patients who received a higher prescribed margin dose (P = .05) and maximum dose (P = .041). Post-SRS hemorrhage occurred in 8.8% (n = 18). Annual postgamma knife latency period hemorrhage was 1.5%. Radiation-induced complications were radiologically evident in 35.6% (n = 73), symptomatic in 14.6% (n = 30), and permanent in 14.6% (n = 30, which included long-tract signs and new cranial nerve deficits). FO was achieved in 64.4% (n = 132). Predictors of an FO were a higher Virginia radiosurgery AVM scale score (P = .003), prior hemorrhage (P = .045), and a lower prescribed maximum dose (P = .006). CONCLUSION: SRS for bAVMs results in obliteration and avoids permanent complications in the majority of patients.

[RADIOSURGERY FOR PITUITARY ADENOMAS].

INTRODUCTION: Pituitary adenomas represent one of the most common types of intracranial tumors, accounting for 10-20% of intracranial tumors. While their macroscopic appearance and anatomical location are relatively homogeneous, pituitary tumors differ widely, generating a variety of neurological and endocrine clinical sequelae. Treatment options include hormone suppressive medical therapy, microscopic or endoscopic neurosurgical resection, radiosurgery, radiation therapy, or observation depending on the biochemical profile and the clinical status of the patient. Some pituitary adenomas spread locally to invade surrounding meninges (Dura) and cavernous sinus, hampering a complete surgical resection. Radiosurgery is most commonly utilized as adjunctive treatment following incomplete surgical resection leaving residual tumor, tumor recurrence, or failure of medical therapy. We present a comprehensive literature review of the radiosurgery series for treatment of different pituitary adenomas including nonfunctioning adenomas, ACTH- and GH-secreting adenomas, as well as prolactinomas. While post-radiosurgery radiographic tumor control for nonfunctioning adenomas is excellent, typically at 90%, the rates of endocrine biochemical remission for functioning adenomas are lower than the tumor control rates. A higher dose is needed to attain endocrine remission as compared to attaining only tumor control. The highest endocrine remission rates are achieved by patients with Cushing's disease and the lowest in those with prolactinomas. The most common complication of radiosurgery is delayed hypopituitarism followed by cranial neuropathies. The effect of suppressive medications on radiosurgery outcomes remains controversial. Due to the rare but well-documented occurrence of late recurrence following endocrine remission, long-term and rigorous clinical and radiographic follow-up is necessary for all pituitary adenoma patients.

The effect of timing of stereotactic radiosurgery treatment of melanoma brain metastases treated with ipilimumab.

OBJECTIVE Melanoma represents the third most common cause of CNS metastases. Immunotherapy has evolved as a treatment option for patients with Stage IV melanoma. Stereotactic radiosurgery (SRS) also elicits an immune response within the brain and may interact with immunotherapy. The authors report on a cohort of patients treated for brain metastases with immunotherapy and evaluate the effect of SRS timing on the intracranial response. METHODS All consecutively treated melanoma patients receiving ipilimumab and SRS for treatment of brain metastases at the University of Virginia between 2009 and 2014 were included in this retrospective analysis; data from 46 patients harboring 232 brain metastases were reviewed. The median duration of clinical follow-up was 7.9 months (range 3-42.6 months). The median age of the patients was 63 years (range 24.3-83.6 years). Thirty-two patients received SRS before or during ipilimumab cycles (Group A), whereas 14 patients received SRS after ipilimumab treatment (Group B). Radiographic and clinical responses were assessed at approximately 3-month intervals after SRS. RESULTS The 2 cohorts were comparable in pertinent baseline characteristics with the exception of SRS timing relative to ipilimumab. Local recurrence-free duration (LRFD) was significantly longer in Group A (median 19.6 months, range 1.1-34.7 months) than in Group B patients (median 3 months, range 0.4-20.4 months) (p = 0.002). Post-SRS perilesional edema was more significant in Group A. CONCLUSIONS The effect of SRS and ipilimumab on LRFD seems greater when SRS is performed before or during ipilimumab treatments. The timing of immunotherapy and SRS may affect LRFD and postradiosurgical edema. The interactions between immunotherapy and SRS warrant further investigation so as to optimize the therapeutic benefits and mitigate the risks associated with multimodality, targeted therapy.

Vaccination as primary prevention? The effect of anti-pneumococcal vaccination on the outcome of patients suffering traumatic skull base fractures.

BACKGROUND: As many as 360,000 people suffer yearly from skull base fractures (SBF). These may be associated with a dural tear, hemosinus, otorrhea or rhinorrhea. The most common causative agent of post-traumatic meningitis is Streptococcus Pneumonia (Pneumococcus). PNEUMOVAX 23 is a potent vaccine against Pneumococcus, but head trauma involving any skull fractures are not defined indications for its use. Our aim was to identify the effect of PNEUMOVAX on the natural course and incidence of infections and infectious prognosis following SBF. METHODS: A retrospective review of patients suffering a traumatic SBF who were admitted to the Department of Neurosurgery at a single tertiary hospital referred from the entire north of Israel during 2002-2009 were characterized. Six hundred and two patients patients were included in the study; 99 patients received the PNEUMOVAX in the first few days of hospitalization, while 503 patients did not. Demographic data, presenting symptoms, chronic illnesses and radiologic features were logged. Treatment regimens were logged as well, including the use of PNEUMOVAX vaccine. Outcome parameters including infectious complications and functional state were logged at different set time points after admission. RESULTS: The group receiving the vaccine had a significantly older mean age, higher incidence of obesity, higher rate of headache or confusion on presentation, and a significantly higher incidence of additional cranial injuries. All these factors, known to worsen the outcome of SBF patients did not manifest in the vaccinated group. There was no statistically significant differences between the groups in the outcome parameters measured (fever, meningitis, mortality or length of hospitalization). CONCLUSIONS: We suggest that patients with a more severe status upon admission may benefit from a prophylactic treatment with the PNEUMOVAX vaccine.

Major-histocompatibility complex harnessing and lymphocytic recruitment: a new tool for glioblastoma multiforme immunotherapy.

Glioblastoma multiforme (GBM) is the most common malignant primary brain neoplasm, notorious for being able to evade and suppress the immune-system. We present a new immunotherapeutic approach that can potentially overcome or circumvent many of the GBM laden obstacles for an efficient antitumor immune response. In this molecular construct, a soluble major-histocompatibility complex (MHC), presenting an immunogenic peptide is directed towards GBM cells. This soluble complex is known to be able to activate relevant cytotoxic T-lymphocyte (CTL's) populations, mounting an effective local immune response. The chimeric protein consists of a targeting domain, a function that can be fulfilled by an antibody or other small molecule that binds tumor associated antigens, and an effector domain. A single chain MHC directly linked to an immunogenic Cytomegalovirus derived peptide (phosphoprotein 65) can be used as such an effector domain. Targeting MHC complexes to the tumor enables to recruit different lymphocyte populations using MHC-molecules bearing a single, highly antigenic peptide derived from immunogenic T cell epitopes. Moreover, the recruited potent memory CTL's at the tumor's milieu may prove resistant to the previously described local immunosuppressive environment, and may enable the shift to TH1 cytokine profile resulting in specific massive tumor destruction.

Relapsed or refractory primary central nervous system lymphoma radiosurgery: Report of the International Gamma Knife Research Foundation.

Stereotactic radiosurgery (SRS) can be used as part of multimodality management for patients with primary central nervous system lymphoma (PCNSL). The objective of this study is to evaluate outcomes of SRS for this disease. The International Gamma Knife Research Foundation identified 23 PCNSL patients who underwent SRS for either relapsed (intracerebral in-field or out-of-field tumor recurrences) or refractory disease from 1995-2014. All 23 patients presented with RPA Class I or II PCNSL, and were initially treated with a median of 7 cycles of methotrexate-based chemotherapy regimens (range, 3-26 cycles). Ten received prior whole brain radiation (WBRT) to a median dose of 43 Gy (range, 24-55 Gy). Sixteen presented with relapsed PCNSL, and seven presented with refractory disease. Twenty-three received 26 procedures of SRS. The median tumor volume was 4 cm3 (range, 0.1-26 cm3), and the median margin dose was 15 Gy (range, 8-20 Gy). Median follow-up from SRS was 11 months (interquartile range, 5.7-33.2 months). Twenty presented with treatment response to twenty-three tumors (12 complete, 11 partial). Fourteen patients relapsed or were refractory to salvage SRS, and local control was 95%, 91%, and 75% at 3, 6, and 12 months post SRS. Intracranial (in-field and out-of-field) and distant (systemic) PFS was 86%, 81%, and 55% at 3, 6, and 12 months post SRS. Toxicity of SRS was low, with one developing an adverse radiation effect requiring no additional intervention. Although methotrexate-based chemotherapy regimens with or without WBRT is the first-line management option for PCNSL, SRS may be used as an alternative option in properly selected patients with smaller relapsed or refractory PCNSL tumors.