Gamma knife radiosurgery for pilocytic astrocytomas

Pediatric Pituitary Adenoma: Case Series, Review of the Literature, and a Skull Base Treatment Paradigm

Background  Pediatric pituitary adenoma is a rare skull base neoplasm, accounting for 3% of all intracranial neoplasms in children and 5% of pituitary adenomas. Compared with pituitary tumors in adults, secreting tumors predominate and longer disease trajectories are expected due to the patient age resulting in a natural history and treatment paradigm that is complex and controversial. Objectives  The aims of this study were to describe a large, single-institution series of pediatric pituitary adenomas with extensive long-term follow-up and to conduct a systematic review examining outcomes after pituitary adenoma surgery in the pediatric population. Methods  The study cohort was compiled by searching institutional pathology and operative reports using diagnosis and site codes for pituitary and sellar pathology, from 1956 to 2016. Systematic review of the English language literature since 1970 was conducted using PubMed, MEDLINE, Embase, and Google Scholar. Results  Thirty-nine surgically managed pediatric pituitary adenomas were identified, including 15 prolactinomas, 14 corticotrophs, 7 somatotrophs, and 4 non-secreting adenomas. All patients underwent transsphenoidal resection (TSR) as the initial surgical treatment. Surgical cure was achieved in 18 (46%); 21 experienced recurrent/persistent disease, with secondary treatments including repeat surgery in 10, radiation in 14, adjuvant pharmacotherapy in 11, and bilateral adrenalectomy in 3. At the last follow-up (median 87 months, range 3-581), nine remained with recurrent/persistent disease (23%). Thirty-seven publications reporting surgical series of pediatric pituitary adenomas were included, containing 1,284 patients. Adrenocorticotropic hormone (ACTH)-secreting tumors were most prevalent (43%), followed by prolactin (PRL)-secreting (37%), growth hormone (GH)-secreting (12%), and nonsecreting (7%). Surgical cure was reported in 65%. Complications included pituitary insufficiency (23%), permanent visual dysfunction (6%), chronic diabetes insipidus (DI) (3%), and postoperative cerebrospinal fluid (CSF) leak (4%). Mean follow-up was 63 months (range 0-240), with recurrent/persistent disease reported in 18% at the time of last follow-up. Conclusion  Pediatric pituitary adenomas are diverse and challenging tumors with complexities far beyond those encountered in the management of routine adult pituitary disease, including nuanced decision-making, a technically demanding operative environment, high propensity for recurrence, and the potentially serious consequences of hypopituitarism with respect to fertility and growth potential in a pediatric population. Optimal treatment requires a high degree of individualization, and patients are most likely to benefit from consolidated, multidisciplinary care in highly experienced centers.

Synchrotron-generated microbeams induce hippocampal transections in rats

Synchrotron-generated microplanar beams (microbeams) provide the most stereo-selective irradiation modality known today. This novel irradiation modality has been shown to control seizures originating from eloquent cortex causing no neurological deficit in experimental animals. To test the hypothesis that application of microbeams in the hippocampus, the most common source of refractory seizures, is safe and does not induce severe side effects, we used microbeams to induce transections to the hippocampus of healthy rats. An array of parallel microbeams carrying an incident dose of 600 Gy was delivered to the rat hippocampus. Immunohistochemistry of phosphorylated γ-H2AX showed cell death along the microbeam irradiation paths in rats 48 hours after irradiation. No evident behavioral or neurological deficits were observed during the 3-month period of observation. MR imaging showed no signs of radio-induced edema or radionecrosis 3 months after irradiation. Histological analysis showed a very well preserved hippocampal cytoarchitecture and confirmed the presence of clear-cut microscopic transections across the hippocampus. These data support the use of synchrotron-generated microbeams as a novel tool to slice the hippocampus of living rats in a minimally invasive way, providing (i) a novel experimental model to study hippocampal function and (ii) a new treatment tool for patients affected by refractory epilepsy induced by mesial temporal sclerosis.

Review of Surgical Anatomy of the Tumors Involving Cavernous Sinus

The lesions involving cavernous sinus (CS) and lateral sellar region includes tumors, vascular lesions, infection, inflammation, and trauma. Tumors associated with CS cause significant distortion of the microanatomy posing an additional surgical challenge to the neurosurgeons. The surgical approach and microsurgical anatomy with respect to the origin and growth of the tumor within the CS region have not been comprehensively described in recent years. We conducted a review of literature concerning CS and associated tumors, complied through MEDLINE/OVID and using cross-references of articles on PubMed with the keywords cavernous sinus, CS tumors, pituitary adenoma, meningioma, schwannoma, chordoma, CS hemangiomas, extradural, interdural, intradural, skull base, gamma knife radiosurgery, endoscopic endonasal approach. Based on the tumor origin and growth pattern, the tumors associated with CS can be classified into three categories: Type-I: tumor originating from CS, Type-II: originating from lateral wall of CS, and Type-III: extraneous origin and occupying CS. The review focuses on approach to a tumor within each type of tumor in the CS region. The emphasis is that the tumor growth pattern and significant distortion of the CS anatomy caused by the tumor growth should be considered while planning the optimal surgical approach for tumors in this region to ensure complete tumor resection with minimal neurovascular morbidity.

Rat sensorimotor cortex tolerance to parallel transections induced by synchrotron-generated X-ray microbeams

Microbeam radiation therapy is a novel preclinical technique, which uses synchrotron-generated X-rays for the treatment of brain tumours and drug-resistant epilepsies. In order to safely translate this approach to humans, a more in-depth knowledge of the long-term radiobiology of microbeams in healthy tissues is required. We report here the result of the characterization of the rat sensorimotor cortex tolerance to microradiosurgical parallel transections. Healthy adult male Wistar rats underwent irradiation with arrays of parallel microbeams. Beam thickness, spacing and incident dose were 100 or 600 µm, 400 or 1200 µm and 360 or 150 Gy, respectively. Motor performance was carried over a 3-month period. Three months after irradiation rats were sacrificed to evaluate the effects of irradiation on brain tissues by histology and immunohistochemistry. Microbeam irradiation of sensorimotor cortex did not affect weight gain and motor performance. No gross signs of paralysis or paresis were also observed. The cortical architecture was not altered, despite the presence of cell death along the irradiation path. Reactive gliosis was evident in the microbeam path of rats irradiated with 150 Gy, whereas no increase was observed in rats irradiated with 360 Gy.

Early versus late Gamma Knife radiosurgery following transsphenoidal surgery for nonfunctioning pituitary macroadenomas: a multicenter matched-cohort study

OBJECTIVE Gamma Knife radiosurgery (GKRS) is frequently used to treat residual or recurrent nonfunctioning pituitary macroadenomas. There is no consensus as to whether GKRS should be used early after surgery or if radiosurgery should be withheld until there is evidence of imaging-defined progression of tumor. Given the high incidence of adenoma progression after subtotal resection over time, the present study intended to evaluate the effect of timing of radiosurgery on outcome. METHODS This is a multicenter retrospective review of patients with nonfunctioning pituitary macroadenomas who underwent transsphenoidal surgery followed by GKRS from 1987 to 2015 at 9 institutions affiliated with the International Gamma Knife Research Foundation. Patients were matched by adenoma and radiosurgical parameters and stratified based on the interval between last resection and radiosurgery. Operative results, imaging data, and clinical outcomes were compared across groups following early (≤ 6 months after resection) or late (> 6 months after resection) radiosurgery. RESULTS After matching, 222 patients met the authors' study criteria (from an initial collection of 496 patients) and were grouped based on early (n = 111) or late (n = 111) GKRS following transsphenoidal surgery. There was a greater risk of tumor progression after GKRS (p = 0.013) and residual tumor (p = 0.038) in the late radiosurgical group over a median imaging follow-up period of 68.5 months. No significant difference in the occurrence of post-GKRS endocrinopathy was observed (p = 0.68). Thirty percent of patients without endocrinopathy in the early cohort developed new endocrinopathies during the follow-up period versus 27% in the late cohort (p = 0.84). Fourteen percent of the patients in the early group and 25% of the patients in the late group experienced the resolution of endocrine dysfunction after original presentation (p = 0.32). CONCLUSIONS In this study, early GKRS was associated with a lower risk of radiological progression of subtotally resected nonfunctioning pituitary macroadenomas compared with expectant management followed by late radiosurgery. Delaying radiosurgery may increase patient risk for long-term adenoma progression. The timing of radiosurgery does not appear to significantly affect the rate of delayed endocrinopathy.

Multimodality Management of Cavernous Sinus Hemangiomas-An Institutional Experience

Objective  Cavernous sinus hemangiomas (CSHs) are benign lesions accounting for less than 2% of the cavernous sinus tumors. They provide a formidable surgical challenge because of their vascularity and their being surrounded by critical neurovascular structures. In this study, one of the largest in available literature, we analyze our experience in the management of these unusual tumors and review the available literature. Materials  This is a retrospective analysis of patients who were managed surgically (both microsurgical and Gamma knife radiosurgery [GKRS]) for CSH at our Institution from 2007 to 2015. Complete demographic, clinical-radiologic surgical records were analyzed. Follow-up data were collected from the hospital records. Results  Total 23 patients were managed. Among these, 15 patients underwent microsurgery (group 1) whereas 8 underwent GKRS (group 2). Predominant clinical presentation in both the groups included headache and involvement of multiple cranial nerves. Five patients in group 1 had deteriorating vision. The volume of tumors ranged from 29 to 115 cm ³ (mean = 64.57 cm ³ ) in group 1 and from 2.1 to 11.6 cm ³ in group 2. GKRS was performed with a mean dose of 13 Gy, an average isodose line of 50% with an average coverage of 96%. In group 1, the follow-up period ranged from 6 to 62 months (mean = 29.4 months). The extraocular movement (EOM) preservation rate in our series was not favorable, as most patients presented late with large tumors and established deficits. Recurrence/residual tumor was seen in two cases. In group 2, the follow-up was 5 to 48 months. All of them showed significant reduction in size. Conclusion  Both surgery and radiosurgery are highly effective in the management of CSHs. They are complementary to each other, with individual characteristics-the size and volume of the lesion-being the main factors in deciding the choice of treatment.

Detection of residual metastatic tumor in the brain following Gamma Knife radiosurgery using a single or a series of magnetic resonance imaging scans: An autopsy study

The aim of the present study was to investigate the usefulness of magnetic resonance image (MRI) for the detection of residual tumors following Gamma Knife radiosurgery (GKR) for brain metastases based on autopsy cases. The study investigated two hypotheses: i) Whether a single MRI may detect the existence of a tumor; and ii) whether a series of MRIs may detect the existence of a tumor. The study is a retrospective case series in a single institution. A total of 11 brain metastases in 6 patients were treated with GKR between 2002 and 2011. Histopathological specimens from autopsy were compared with reconstructed follow-up MRIs. The maximum diameters of the lesions on MRI series were measured, and the size changes classified. The primary sites in the patients were the kidneys (n=2), lung (n=1), breast (n=1) and colon (n=1), as well as 1 adenocarcinoma of unknown origin. The median prescribed dose for radiosurgery was 20 Gy (range, 18-20 Gy), and median time interval between GKR and autopsy was 10 months (range, 1.6-20 months). The pathological outcomes included 7 remissions and 4 failures. Enhanced areas on gadolinium-enhanced MRI contained various components: Viable tumor cells, tumor necrosis, hemorrhage, inflammation and vessels. Regarding the first hypothesis, it was impossible to distinguish pathological failure from remission with a single MRI scan due to the presence of various components. Conversely, in treatment response (remission or failure), on time-volume curves of MRI scans were in agreement with pathological findings, with the exception of progressive disease in the acute phase (0-3 months). Thus, regarding the second hypothesis, time-volume curves were useful for predicting treatment responses. In conclusion, it was difficult to predict treatment response using a single MRI, and a series of MRI scans were required to detect the existence of a tumor.

Optimal treatment of jugular foramen schwannomas: long-term outcome of a multidisciplinary approach for a series of 29 cases in a single institute

BACKGROUND

The goal of treatment for jugular foramen schwannomas (JFSs) is to achieve complete tumor removal with cranial nerve preservation. However, achieving this goal remains a challenge despite the advances in microsurgical techniques. The aim of this study was to determine optimal treatment strategies for JFSs based on a review of a series of 29 surgical cases in our institute.

MATERIALS AND METHODS

Between 1997 and 2013, 29 patients with JFSs underwent surgical treatment by multidisciplinary otoneurosurgical approaches. We retrospectively evaluated various clinical outcomes including the extent of tumor resection, postoperative cranial nerve deficits, and the recurrence rate. Tumor extension was classified using the Kaye and Pellet classification (KPC) system, and the extent of tumor resection was graded as gross total resection (GTR), near total resection (NTR), and subtotal resection (STR). We utilized the House-Brackmann facial nerve grading system (HBFNGS), the average pure-tone audiometry and speech audiometry (PTA/SA) tests, and the American Speech-Language-Hearing Association National Outcome Measurement System (ASHA NOMS) swallowing scale (ASHA level) for assessment of functional outcomes.

RESULTS

The extent of tumor resection was not related to the degree of immediate postoperative cranial nerve deficits. However, the surgical approach was significantly related to postoperative hearing status and immediate postoperative facial function. Also, among the ten patients who were below the level of acceptable facial function immediately postoperatively, nine patients (90%) recovered to acceptable facial function by the last follow-up. Concerning postoperative swallowing status, all 21 patients recovered swallowing function by the last follow-up. Postoperative Gamma Knife stereotactic radiosurgery (GKRS) was performed for three recurrent and seven residual tumors, and recurrence was not observed in the mean 36-month follow-up period.

CONCLUSIONS

A surgical strategy should be tailored to the individual case, and clinicians should consider the possibility of recurrence and further adjuvant treatment.

Stereotactic radiosurgery alone for multiple brain metastases? A review of clinical and technical issues

Over the past three decades several randomized trials have enabled evidence-based practice for patients presenting with limited brain metastases. These trials have focused on the role of surgery or stereotactic radiosurgery (SRS) with or without whole brain radiation therapy (WBRT). As a result, it is clear that local control should be optimized with surgery or SRS in patients with optimal prognostic factors presenting with up to 4 brain metastases. The routine use of adjuvant WBRT remains debatable, as although greater distant brain control rates are observed, there is no impact on survival, and modern outcomes suggest adverse effects from WBRT on patient cognition and quality of life. With dramatic technologic advances in radiation oncology facilitating the adoption of SRS into mainstream practice, the optimal management of patients with multiple brain metastases is now being put forward. Practice is evolving to SRS alone in these patients despite a lack of level 1 evidence to support a clinical departure from WBRT. The purpose of this review is to summarize the current state of the evidence for patients presenting with limited and multiple metastases, and to present an in-depth analysis of the technology and dosimetric issues specific to the treatment of multiple metastases.

Radiotherapy for renal cell carcinoma: renaissance of an overlooked approach

Conventional radiotherapy previously had a limited role in the definitive treatment of renal cell carcinoma (RCC), owing to the disappointing outcomes of several trials and the perceived radioresistance of this type of cancer. In this context, radiotherapy has been relegated largely to the palliation of symptoms in patients with metastatic disease, with variable rates of response. Following the availability of newer technologies that enable safe delivery of high-dose radiotherapy, stereotactic ablative radiotherapy (SABR) has become increasingly used in patients with RCC. Preclinical evidence demonstrates that RCC cells are sensitive to ablative doses of radiotherapy (≥8-10 Gy). Trials in the setting of intracranial and extracranial oligometastases, as well as primary RCC, have demonstrated excellent tumour control using this approach. Additionally, an awareness of the capacity of high-dose radiation to stimulate antitumour immunity has resulted in novel combinations of SABR with immunotherapies. Here we describe the historical application of conventional radiotherapy, the current biological understanding of the effects of radiation, and the clinical evidence supporting the use of ablative radiotherapy in RCC. We also explore emerging opportunities to combine systemic targeted agents or immunotherapies with radiation. Radiotherapy, although once an overlooked approach, is moving towards the forefront of RCC treatment.

Truebeam Radiosurgery for the Treatment of Trigeminal Neuralgia: Preliminary Results at a Single Institution

INTRODUCTION

Radiosurgery is now an established method of satisfactory pain control in patients with trigeminal neuralgia (TN). The Varian Truebeam STx (Varian Medical Systems, Palo Alto, CA) linear accelerator (LINAC) system is an arc-based, frameless stereotactic radiosurgery system used for the treatment of TN. To our knowledge, there has been only one published series of patient histories that documents the use of a frameless LINAC system for the treatment of TN. We describe the treatment parameters, patient outcomes, and complications associated with the treatment of TN.

METHODS

All patients treated with the Truebeam system for TN between 2012 and 2015, with at least a six-month follow-up, were identified. A dose of 90 Gy was delivered to the isocenter using a 0.5 cm diameter cone. The cisternal segment of the trigeminal nerve was placed at the location of the LINAC isocenter using an ExacTrac™ (Brainlab, Munich, Germany) image guidance system. The radiosurgical dose, Barrow Neurologic Institute pain score (BNI PS), symptom recurrence, magnetic resonance imaging (MRI) radiographic changes, and other complications, including Barrow Neurologic Institute facial numbness score (BNI FN), were analyzed.

RESULTS

A total of 18 patients-15 women and 3 men-with a mean age of 58 years (median: 59 years; range: 22-84 years) were treated at our institution. Fourteen patients (78%) had a BNI PS of IIIb or better, which was considered successful treatment. Twelve patients had excellent (BNI PS I) pain relief and two patients had good (BNI PS II-IIIB; recurrence after one year) pain relief. The pain of four patients recurred after a mean of 10 months.

CONCLUSION

Truebeam radiosurgery can provide effective and safe treatment for patients suffering from TN. The efficacy appears similar to other frame- and frameless-based systems.

Evaluation of outcomes after stereotactic radiosurgery for pilocytic astrocytoma

Pilocytic astrocytomas are rare intracranial gliomas that are typically treated with surgical extirpation. Our aim was to report the radiologic and clinical outcomes of patients treated with stereotactic radiosurgery (SRS) for pilocytic astrocytoma in the primary and salvage setting. Patients with pilocytic astrocytoma treated at a single institution with SRS from 1990 to 2015 were reviewed. Patient, disease, and treatment characteristics were collected and overall survival, local control, and toxicity were evaluated. Twenty-eight consecutive patients (12 females and 16 males) with a median age of 17.4 years at SRS were identified. Overall, 46% of patients were treated with SRS as part of the initial treatment course after biopsy or subtotal resection, and the remainder as a salvage therapy. The most common location was the cerebellum (28%) followed by brainstem and basal ganglia (21 and 18%, respectively). Four patients received prior external beam radiation therapy (14%). Median tumor volume was 1.84 cc (0.19-15.94 cc), and 39% had a cystic component at SRS. Prescription dose ranged from 4 to 20 Gy (median 16 Gy) to a median isodose line of 50% (range 30-100%). With a median follow-up of 5.2 years (0.3-17.1 years), all patients remained alive at last follow-up. Two patients demonstrated evidence of local radiographic progression at last follow-up (7%). No toxicity could be directly attributed to SRS. In this SRS series, durable tumor control was achieved in 93% of patients with pilocytic astrocytoma, although continued follow up will be important giving the natural history of this disease. As demonstrated, SRS is an appropriate technique in the primary and recurrent treatment of pilocytic astrocytoma that offers favorable disease control and infrequent clinical toxicity.

Gamma knife radiosurgery for the treatment of uveal melanoma and uveal metastases

Background

This study retrospectively analyzed outcomes for patients undergoing gamma knife radiosurgery (GKR) for uveal melanoma (UM) and intraocular metastases.

Methods

Patients who underwent GKR for UM or intraocular metastases between 1/1/1990 and 6/1/2015 at Mayo Clinic, Rochester, MN, USA, were retrospectively analyzed.

Results

Eleven patients (11 eyes) had UM while seven patients (7 eyes) had intraocular metastases. Patients with UM were followed for a median of 19.74 ± 10.4 months. Visual acuity (VA) logMAR 0.30 ± 0.53 (Snellen 20/40) versus 0.40 ± 0.97 (Snellen 20/50), tumor thickness (5.30 ± 2.17 vs. 3.60 ± 2.32 mm), were not significantly different between preoperative and postoperative measurements, respectively. Nine percent (1/11) patients required enucleation. Subsequently, no patients experienced metastases. Patients with intraocular metastases were followed for a median of 6.03 ± 6.32 months. They did not have significant changes in VA (logMAR 0.30 ± 0.59 vs. 0.30 ± 1.57; Snellen 20/40 vs. 20/40) or tumor thickness (3.50 ± 1.36 vs. 1.30 ± 0.76 mm) postoperatively. Fourteen percent (1/7 patients) required enucleation. Complications experienced by patients with UM include radiation retinopathy (2/11), papillopathy (1/11), cystoid macular edema (1/11), vitreomacular traction (1/11), exudative retinal detachment (1/11). Patients with metastases had treatment complicated by recurrence (2/7). Dose to the margin, maximum dose of radiation, and clinical target volume did not correlate with post-procedural VA, risk of enucleation, or death in patients with either UM or patients with intraocular metastases.

Conclusions

Visual outcomes were satisfactory for patients undergoing GKR without significant morbidity and without significant risk of enucleation or metastases.

A Single-Institution Analysis of 126 Patients Treated with Stereotactic Radiosurgery for Brain Metastases

Background

The objective of this study was to report our institutional experience with Gamma Knife^® Radiosurgery (GKRS) in the treatment of patients with brain metastases.

Methods

Retrospectively collected demographic and clinical data on 126 patients with intracranial metastases were reviewed. The patients in our study underwent GKRS at Vidant Medical Center between 2009 and 2014. Kaplan–Meier curves were used to compare survival based on clinical characteristics for univariate analysis, and a Cox proportional hazards model was used for multivariate analysis.

Results

The median age of the patient population was 62 years. Medicare patients constituted 51% of our patient cohort and Medicaid patients 15%. The most common tumor histologies were non-small cell lung cancer (50%), breast cancer (12.7%), and melanoma (11.9%). The median overall survival time for all patients was 5.8 months. Patients with breast cancer had the longest median survival time of 9.15 months, while patients with melanoma had the shortest median survival time of 2.86 months. On univariate analysis, the following factors were predictors for improved overall survival, ECOG score 0 or 1 vs. 2 or greater (17.0 vs. 1.8 months, p < 0.001), controlled extracranial disease vs. progressive extracranial disease (17.4 vs. 4.6 months, p = 0.0001), recursive partitioning analysis Stage I vs. II–III (18.2 vs. 6.2 months, p < 0.007), multiple GKRS treatments (p = 0.002), prior brain metastasectomy (p = 0.012), and prior chemotherapy (p = 0.021). Age, ethnicity, gender, previous external beam radiation therapy, number of brain metastases, and hemorrhagic vs. non-hemorrhagic tumors were not predictors of longer median survival time. Number of metastatic brain lesions of 1–3 vs. ≥4 (p = 0.051) and insurance status of Medicare/Medicaid vs. commercial insurance approached significance (13.7 vs. 6.8 months, p = 0.08). On multivariate analysis, ECOG performance status 0–1 (p < 0.001), multiple GKRS treatments (p = 0.003), and control of extracranial disease (p = 0.001) remained significant predictors of survival.

Conclusion

ECOG score, control of extracranial disease, and multiple GKRS treatments are predictors of longer median survival following GKRS in our patient population. GKRS is an effective treatment for brain metastases, but these factors may be considered in patient selection for GKRS.

Role of MRI in Diagnosis of Ruptured Intracranial Dermoid Cyst

Introduction:

Intracranial dermoid cystic tumors account for <1% of all intracranial masses.

Case report:

A 52-year-old male, having headaches, nausea and is presented with a history of 2 episodes of new onset seizures. On presentation, the patient had a normal physical exam, including a complete neurological and cranial nerve exam.

Methods:

Precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D – HI-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W, Flash/T2W oblique coronal plane, GRE/T2W axial. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping, postcontrast: TSE/T1W sequence in axial, coronal and sagittal planes.

Results:

Subsequent MRI of the brain revealed an oval and lobulated 47x34x30mm (TRxAPxCC) non-enhancing T1-hyperintense mass in right cavernous sinus, with compression of surrounding mesial temporal lobe and right anterolateral aspect of mesencephalon. Findings are consistent with ruptured dermoid cyst, given the evacuated sebum content at its lower half. Sebum particles in millimetric sizes are seen within right Sylvian fissure, anterior horns of lateral ventricles and to a lesser extent within left Sylvian fissure, right parietal sulci, cerebral aqueduct, and basal cisterns. No restricted diffusion is seen, eliminating the possibility of epidermoid. A shunt catheter is evident traversing between right lateral ventricle and right parietal bone; besides, slit-like right lateral ventricle is noted (likely secondary to over-draining shunt catheter).

Conclusion:

Intracranial dermoid cysts are benign rare slow-growing tumors that upon rupture, however, widespread presence of T1 hyperintense droplets and leptomeningeal enhancement can be noted–making MRI the best imaging modality for diagnosis of this rare entity.

Analysis of volumetric response of pituitary adenomas receiving adjuvant CyberKnife stereotactic radiosurgery with the application of an exponential fitting model

Tumor control rates of pituitary adenomas (PAs) receiving adjuvant CyberKnife stereotactic radiosurgery (CK SRS) are high. However, there is currently no uniform way to estimate the time course of the disease. The aim of this study was to analyze the volumetric responses of PAs after CK SRS and investigate the application of an exponential decay model in calculating an accurate time course and estimation of the eventual outcome.A retrospective review of 34 patients with PAs who received adjuvant CK SRS between 2006 and 2013 was performed. Tumor volume was calculated using the planimetric method. The percent change in tumor volume and tumor volume rate of change were compared at median 4-, 10-, 20-, and 36-month intervals. Tumor responses were classified as: progression for >15% volume increase, regression for ≤15% decrease, and stabilization for ±15% of the baseline volume at the time of last follow-up. For each patient, the volumetric change versus time was fitted with an exponential model.The overall tumor control rate was 94.1% in the 36-month (range 18-87 months) follow-up period (mean volume change of -43.3%). Volume regression (mean decrease of -50.5%) was demonstrated in 27 (79%) patients, tumor stabilization (mean change of -3.7%) in 5 (15%) patients, and tumor progression (mean increase of 28.1%) in 2 (6%) patients (P = 0.001). Tumors that eventually regressed or stabilized had a temporary volume increase of 1.07% and 41.5% at 4 months after CK SRS, respectively (P = 0.017). The tumor volume estimated using the exponential fitting equation demonstrated high positive correlation with the actual volume calculated by magnetic resonance imaging (MRI) as tested by Pearson correlation coefficient (0.9).Transient progression of PAs post-CK SRS was seen in 62.5% of the patients receiving CK SRS, and it was not predictive of eventual volume regression or progression. A three-point exponential model is of potential predictive value according to relative distribution. An exponential decay model can be used to calculate the time course of tumors that are ultimately controlled.

STEREOTACTIC RADIATION THERAPY IN PITUITARY ADENOMAS, IS IT BETTER THAN CONVENTIONAL RADIATION THERAPY?

Pituitary radiotherapy (RT) has undergone important progress in the last decades due to the development of new stereotactic techniques which provide more precise tumour targeting with less overall radiation received by the adjacent brain structures. Pituitary surgery is usually first-line therapy in most patients with nonfunctioning (NFPA) and functioning adenomas (except for prolactinomas and large growth hormone (GH) secreting adenomas), while RT is used as second or third-line therapy. The benefits of RT (tumour volume control and, in functional tumours, decreased hormonal secretion) are hampered by the long latency of the effect and the potential side effects. This review presents the updates in the efficacy and safety of the new stereotactic radiation techniques in patients with NFPA, GH-, ACTH- or PRL-secreting pituitary adenomas.

Methods

A systematic review was performed using PubMed and articles/abstracts and reviews detailing RT in pituitary adenomas from 2000 to 2017 were included.

Results

Stereotactic radiosurgery (SRS) and fractionated stereotactic RT (FSRT) provide high rates of tumour control i.e. stable or decrease in tumour size, in all types of pituitary adenomas (median 92 - 98%) at 5 years. Endocrinological remission is however significantly lower: 44-52% in acromegaly, 54-64% in Cushing's disease and around 30% in prolactinomas at 5 years. The rate of new hypopituitarism varies from 10% to 50% at 5 years in all tumour types and as expected increases with the duration of follow-up (FU). The risk for other radiation-induced complications is usually low (0-5% for new visual deficits, cranial nerves damage or brain radionecrosis and extremely low for secondary brain tumours), however longer FU is needed to determine rates of secondary tumours. Notably, in acromegaly, there may be a higher risk for stroke with FSRT.

Conclusion

Stereotactic radiotherapy can be an effective treatment option for patients with persistent or recurrent pituitary adenomas after unsuccessful surgery (especially if residual tumour is enlarging) and/or resistance or unavailability of medical therapy. Comparison with conventional radiation therapy (CRT) is rather difficult, due to the substantial heterogeneity of the studies. In order to evaluate the potential brain-sparing effect of the new stereotactic techniques, suggested by the current data, long-term studies evaluating secondary morbidity and mortality are needed.

Ultra-extended euthermic pulsed radiofrequency for the treatment of ophthalmic neuralgia: A case report with elaboration of a new technique

BACKGROUND

Pulsed radiofrequency although present for many years has been used little compared to ablative procedures for pain relief. Its use in trigeminal neuralgia is sparse and unreported in the ophthalmic division, where the possibility of sensory loss can lead to high morbidity. We wished to explore the potential of this reportedly safe modality for a prolonged duration in a highly sensitive anatomic neural location, however, in a very secure, structured, and staged manner.

CASE DESCRIPTION

A patient suffering from ophthalmic division (V1) medically uncontrolled neuralgia with a preoperative visual analog scale (VAS) score of 9/10 was subjected to a percutaneous pain relief procedure. The patient was treated with prolonged duration pulsed radiofrequency (PRF) for 40 min, with corneal sensation monitoring under conscious sedation keeping a low voltage (7 V) and tip temperature at 37°C. The patient obtained immediate relief, which was verified on the operation table itself. Postoperative VAS score of 0/10 was recorded. More than 6 months after the procedure, the patient is completely free from neuralgic pain and continues to have a VAS score of 0/10.

CONCLUSION

As opposed to conventional PRF where mostly a tip temperature of 42°C and high voltage have been used for 2 to a maximum of 8 min, PRF with a tip temperature of 37°C and a safe voltage of 7 V over an ultra-extended duration of 40 min can give a more distinct and effective but equally safe result. Although our case verified the safety and efficacy of prolonged duration PRF in sensitive anatomic locations, more studies are warranted for establishing this as a standard line of treatment. The specific use of PRF in ophthalmic division neuralgia in the manner described in our case report has hitherto not been reported in medical literature and will open a new vista in the minimally invasive treatment of this disease.

Optimal Treatment Decision for Brain Metastases of Unknown Primary Origin: The Role and Timing of Radiosurgery

Background

Up to 15% of all patients with brain metastases have no clearly detected primary site despite intensive evaluation, and this incidence has decreased with the use of improved imaging technology. Radiosurgery has been evaluated as one of the treatment modality for patients with limited brain metastases. In this study, we evaluated the effectiveness of radiosurgery for brain metastases from unknown primary tumors.

Methods

We retrospectively evaluated 540 patients who underwent gamma knife radiosurgery (GKRS) for brain metastases radiologically diagnosed between August 1992 and September 2007 in our institution. First, the brain metastases were grouped into metachronous, synchronous, and precocious presentations according to the timing of diagnosis of the brain metastases. Then, synchronous and precocious brain metastases were further grouped into 1) unknown primary; 2) delayed known primary; and 3) synchronous metastases according to the timing of diagnosis of the primary origin. We analyzed the survival time and time to new brain metastasis in each group.

Results

Of the 540 patients, 29 (5.4%) presented precocious or synchronous metastases (34 GKRS procedures for 174 lesions). The primary tumor was not found even after intensive and repeated systemic evaluation in 10 patients (unknown primary, 34.5%); found after 8 months in 3 patients (delayed known primary, 1.2%); and diagnosed at the same time as the brain metastases in 16 patients (synchronous metastasis, 55.2%). No statistically significant differences in survival time and time to new brain metastasis were found among the three groups.

Conclusion

Identification of a primary tumor before GKRS did not affect the patient outcomes. If other possible differential diagnoses were completely excluded, early GKRS can be an effective treatment option for brain metastases from unknown primary tumor.

Neurological Change after Gamma Knife Radiosurgery for Brain Metastases Involving the Motor Cortex

BACKGROUND

Although Gamma Knife radiosurgery (GKRS) can provide beneficial therapeutic effects for patients with brain metastases, lesions involving the eloquent areas carry a higher risk of neurologic deterioration after treatment, compared to those located in the non-eloquent areas. We aimed to investigate neurological change of the patients with brain metastases involving the motor cortex (MC) and the relevant factors related to neurological deterioration after GKRS.

METHODS

We retrospectively reviewed clinical, radiological and dosimetry data of 51 patients who underwent GKRS for 60 brain metastases involving the MC. Prior to GKRS, motor deficits existed in 26 patients (50.9%). The mean target volume was 3.2 cc (range 0.001-14.1) at the time of GKRS, and the mean prescription dose was 18.6 Gy (range 12-24 Gy).

RESULTS

The actuarial median survival time from GKRS was 19.2±5.0 months. The calculated local tumor control rates at 6 and 12 months after GKRS were 89.7% and 77.4%, respectively. During the median clinical follow-up duration of 12.3±2.6 months (range 1-54 months), 18 patients (35.3%) experienced new or worsened neurologic deficits with a median onset time of 2.5±0.5 months (range 0.3-9.7 months) after GKRS. Among various factors, prescription dose (>20 Gy) was a significant factor for the new or worsened neurologic deficits in univariate (p=0.027) and multivariate (p=0.034) analysis. The managements of 18 patients were steroid medication (n=10), boost radiation therapy (n=5), and surgery (n=3), and neurological improvement was achieved in 9 (50.0%).

CONCLUSION

In our series, prescription dose (>20 Gy) was significantly related to neurological deterioration after GKRS for brain metastases involving the MC. Therefore, we suggest that careful dose adjustment would be required for lesions involving the MC to avoid neurological deterioration requiring additional treatment in the patients with limited life expectancy.

Therapeutic Strategy for Cavernous Sinus-Invading Non-Functioning Pituitary Adenomas Based on the Modified Knosp Grading System

Background

Non-functioning pituitary adenomas (NFPA) invading into the cavernous sinus are surgically challenging. To decrease recurrence rate, surgeon makes a strong endeavor to resect tumor gross totally. However, gross total resection (GTR) is difficult to achieve with cavernous sinus invasion. Recently, a new classification system for cavernous invasion of pituitary adenomas was suggested. The aim of this study is to validate this new classification system and to identify limitations and considerations in designing treatment strategies for patients with NFPA involving the cavernous sinus.

Methods

Between January 2000 and January 2012, 275 patients who underwent operation for NFPA were enrolled in the study. Median age was 50 years (15–79 years). There were 145 males and 130 females. The median follow-up duration was 4 years (range 1–12.5 years).

Results

Related to extent of tumor removal, GTR was obtained in 184 patients (66.9%), near total resection (NTR) was obtained in 45 patients (16.3%), and sub-total resection (STR) was obtained in 46 patients (16.7%) of a total 275 patients. There were statistically significant differences between the extent of resection and the new Knosp classification (p<0.001). In the high-grade group of the new Knosp classification, there was no difference in recurrence between patients who underwent GTR or NTR only and those who underwent STR with adjuvant radiation therapy (p=0.515).

Conclusion

In case of high risk of surgical complications, STR with adjuvant radiation therapy can be considered as an alternative strategy for safe treatment of cavernous-invading adenomas.

Target delineation and optimal radiosurgical dose for pituitary tumors

Stereotactic radiosurgery (SRS) delivered as either single-fraction or multi-fraction SRS (2–5 fractions) is frequently employed in patients with residual or recurrent pituitary adenoma. The most common delivery systems used for SRS include the cobalt-60 system Gamma Knife, the CyberKnife (CK) robotic radiosurgery system, or a modified conventional radiotherapy machine (linear accelerator, LINAC). Tumor control and normalization of hormone hypersecretion have been reported in 75–100 % and 25–80 % of patients, respectively. Hypopituitarism is the most commonly reported late complication of radiation treatment, whereas other toxicities occur less frequently. We have provided an overview of the recent available literature on SRS in patients with a pituitary adenoma. Critical aspects of pituitary irradiation, including target delineation and doses to organs at risk, optimal radiation dose, as well as the long-term efficacy and toxicity of SRS for either nonfunctioning or secreting pituitary adenomas are discussed. Single-fraction SRS represents an effective treatment for patients with a pituitary adenoma; however, caution should be used for lesions > 2.5–3 cm in size and/or involving the anterior optic pathway. Future studies will be necessary to optimize target doses and critical organ dose constrains in order to reduce the long-term toxicity of treatments while maintaining high efficacy.

Fractionated Stereotactic Gamma Knife Radiosurgery for Large Brain Metastases: A Retrospective, Single Center Study

PURPOSE

Stereotactic radiosurgery (SRS) is widely used for brain metastases but has been relatively contraindicated for large lesions (>3 cm). In the present study, we analyzed the efficacy and toxicity of hypofractionated Gamma Knife radiosurgery to treat metastatic brain tumors for which surgical resection were not considered as the primary treatment option.

METHODS AND MATERIALS

Thirty-six patients, forty cases were treated with Gamma Knife-based fractionated SRS for three to four consecutive days with the same Leksell frame on their heads. The mean gross tumor volume was 18.3 cm³, and the median dose was 8 Gy at 50% isodose line with 3 fractions for three consecutive days (range, 5 to 11 Gy and 2 to 4 fractions for 2 to 4 consecutive days). Survival rates and prognostic factors were analyzed.

RESULTS

The overall survival rate at one and two years was 66.7 and 33.1%, respectively. The median survival time was 16.2 months, and the local control rate was 90%. RTOG toxicity grade 1 was observed in 3 (8.3%) patients, grade 2 in 1 (2.7%) patient and grade 3 in 1 (2.7%) patient respectively. Radiation necrosis was developed in 1 (2.7%) patient. KPS scores and control of primary disease resulted in significant differences in survival.

CONCLUSIONS

Our findings suggest that consecutive hypofractionated Gamma Knife SRS could be applied to large metastatic brain tumors with effective tumor control and low toxicity rates.

Management approach for recurrent brain metastases following upfront radiosurgery may affect risk of subsequent radiation necrosis

Purpose

Many patients treated with stereotactic radiosurgery (SRS) alone as initial treatment require 1 or more subsequent salvage therapies. This study aimed to determine if commonly used salvage strategies are associated with differing risks of radiation necrosis (RN).

Methods and materials

All patients treated with upfront SRS alone for brain metastases at our institution were retrospectively analyzed. Salvage treatment details were obtained for brain failures. Patients who underwent repeat SRS to the same lesion were excluded. RN was determined based on pathological confirmation or advanced brain imaging consistent with RN in a symptomatic patient. Patients were grouped according to salvage treatment and rates of RN were compared via Fisher's exact tests.

Results

Of 284 patients treated with upfront SRS alone, 132 received salvage therapy and 44 received multiple salvage treatments. This included 31 repeat SRS alone, 58 whole brain radiation therapy (WBRT) alone, 28 SRS and WBRT, 7 surgery alone, and 8 surgery with adjuvant radiation. With a median follow-up of 10 months, the rate of RN among all patients was 3.17% (9/284), salvaged patients 4.55% (6/132), and never salvaged patients 1.97% (3/152). Receiving salvage therapy did not significantly increase RN risk (P = .31). Of the patients requiring salvage treatments, the highest RN rate was among patients that had both salvage SRS and WBRT (delivered as separate salvage therapies) (6/28, 21.42%). RN rate in this group was significantly higher than in those treated with repeat SRS alone (0/31), WBRT alone (0/58), surgery alone (0/7), and surgery with adjuvant radiation (0/8). Comparing salvage WBRT doses <30 Gy versus ≥30 Gy revealed no effect of dose on RN rate. Additionally, among patients who received multiple SRS treatments, number of treated lesions was not predictive of RN incidence.

Conclusion

Our results suggest that initial management approach for recurrent brain metastasis after upfront SRS does not affect the rate of RN. However, the risk of RN significantly increases when patients are treated with both repeat SRS and salvage WBRT. Methods to improve prediction of toxicity and optimize patient selection for salvage treatments are needed.

Survival prognostic factors for patients with synchronous brain oligometastatic non-small-cell lung carcinoma receiving local therapy

Introduction

Clinical evidence for patients with synchronous brain oligometastatic non-small-cell lung carcinoma is limited. We aimed to summarize the clinical data of these patients to explore the survival prognostic factors for this population.

Methods

From September 1995 to July 2011, patients with 1–3 synchronous brain oligometastases, who were treated with stereotactic radiosurgery (SRS) or surgical resection as the primary treatment, were identified at Shanghai Chest Hospital.

Results

A total of 76 patients (22 patients underwent brain surgery as primary treatment and 54 patients received SRS) were available for survival analysis. The overall survival (OS) for patients treated with SRS and brain surgery as the primary treatment were 12.6 months (95% confidence interval [CI] 10.3–14.9) and 16.4 months (95% CI 8.8–24.1), respectively (adjusted hazard ratio =0.59, 95% CI 0.33–1.07, P=0.08). Among 76 patients treated with SRS or brain surgery, 21 patients who underwent primary tumor resection did not experience a significantly improved OS (16.4 months, 95% CI 9.6–23.2), compared with those who did not undergo resection (11.9 months, 95% CI 9.7–14.0; adjusted hazard ratio =0.81, 95% CI 0.46–1.44, P=0.46). Factors associated with survival benefits included stage I–II of primary lung tumor and solitary brain metastasis.

Conclusion

There was no significant difference in OS for patients with synchronous brain oligometastasis receiving SRS or surgical resection. Among this population, the number of brain metastases and stage of primary lung disease were the factors associated with a survival benefit.

Subarachnoid hemorrhage caused by an undifferentiated sarcoma of the sellar region

Background:

It is rare for patients with pituitary apoplexy to exhibit concomitant subarachnoid hemorrhage (SAH). Only a handful of patients with pituitary apoplexy have developed such hemorrhagic complications, and histopathological examination revealed pituitary adenoma as the cause of SAH.

Case Report:

A previously healthy 35-year-old woman was brought to our institution after complaining of severe headache and left monocular blindness. Brain computed tomography showed a diffuse SAH with a central low density. Subsequently, the brain magnetic resonance imaging revealed an intrasellar mass with heterogeneous contrast enhancement. The patient was presumptively diagnosed with SAH secondary to hemorrhagic pituitary adenoma and underwent transcranial surgery to remove both the tumor and subarachnoid clot. A histological evaluation of the surgical specimen revealed malignant cells with strong predilection for vascular invasion. Following immunohistochemical evaluation, the tumor was negative for the majority of tumor markers and was positive only for vimentin and p53; thus, a diagnosis of undifferentiated sarcoma was established.

Conclusions:

This case was informative in the respect that tumors other than pituitary adenoma should be included in the differential diagnosis of patients with pituitary apoplexy.

The Role of Preradiosurgical Embolization in the Management of Grades III, IV, and V Arteriovenous Malformations

Objective

To evaluate the role of preradiosurgical embolization on obliteration rate, reduction of size, irradiation dose, and neurological outcome, in 90 patients presenting large arteriovenous malformations (AVMs).

Methods

Between October 1993 and October 2006, 90 radiosurgical procedures were performed to treat brain AVMs Spetzler–Martin (SM) grades III, IV, and V at the Department of Radiosurgery and Radiology of the Real e Benemérita Associação Portuguesa de Beneficência de São Paulo, São Paulo, Brazil. Fifty-nine patients had embolization before radiosurgery and complete clinical and radiologic follow-up for at least 3 years. Inclusion criteria were as follow: SM grades III, IV, and V AVMs, no previous treatment, and clinical and radiological (angiogram and MRI) follow-up for at least 3 years. Obliteration rate, reduction of size, irradiation dose, and neurological outcome were compared in these two cohorts of patients. Mann–Whitney test, “Student’s t-test,” and χ² tests were used for statistical analysis, as appropriate. The level of significance was determined at p < 0.05.

Results

The mean size of the AVMs that underwent embolization was significantly greater when compared with non-embolized group (p < 0.05). Embolization significantly reduced the AVM diameter. Irradiation dose was significantly smaller in the embolized group (p < 0.05). No significant differences in final clinical outcomes, postprocedural radiological findings, rate of occlusion, and need for additional procedures were observed between the two groups (p < 0.05).

Conclusion

Preradiosurgical embolization of large AVMs does not result in impaired obliteration rate compared with cases treated with radiosurgery alone. It did not add further morbidity and presented benefits of reducing size of the AVMs. Preradiosurgical embolization may facilitate the coverage of the AVM with the effective irradiation dose. Combined management may be effective for selected large lesions considered unsuitable for radiosurgery and otherwise untreatable.

Uveal Melanoma: Current Trends in Diagnosis and Management

Uveal melanoma, which is the most common primary intraocular malignancy in adults, arises from melanocytes within the iris, ciliary body and choroid. The diagnosis is based principally on clinical examination of the tumor with biomicroscopy and indirect ophthalmoscopy and confirmed by diagnostic techniques such as ultrasonography, fundus fluorescein angiography and optical coherence tomography. The clinical diagnosis of posterior uveal melanomas can be made when the classical appearance of a pigmented dome-shaped mass is detected on dilated fundus exam. Uveal melanomas classically show low to medium reflectivity on A-scan ultrasonography and on B-scan ultrasonography the tumor appears as a hyperechoic, acoustically hollow intraocular mass. Management of a suspicious pigmented lesion is determined by its risk factors of transforming into a choroidal melanoma, such as documentation of growth, thickness greater than 2 mm, presence of subretinal fluid, symptoms and orange pigment, margin within 3 mm of the optic disc, and absence of halo and drusen. Advances in the diagnosis and local and systemic treatment of uveal melanoma have caused a shift from enucleation to eye-conserving treatment modalities including transpupillary thermotherapy and radiotherapy over the past few decades. Prognosis can be most accurately predicted by genetic profiling of fine needle aspiration biopsy of the tumor before the treatment, and high-risk patients can now be identified for clinical trials that may lead to target-based therapies for metastatic disease and adjuvant therapy which aims to prevent metastatic disease.

Ten-Year Survival of a Patient Treated with Stereotactic Gamma Knife Radiosurgery for Brain Metastases from Colon Cancer with Ovarian and Lymph Node Metastases: A Case Report

Brain metastasis from colorectal cancer is infrequent and carries a poor prognosis. Herein, we present a patient alive 10 years after the identification of a first brain metastasis from sigmoid colon cancer. A 39-year-old woman underwent sigmoidectomy for sigmoid colon cancer during an emergency operation for pelvic peritonitis. The pathological finding was moderately differentiated adenocarcinoma. Eleven months after the sigmoidectomy, a metastatic lesion was identified in the left ovary. Despite local radiotherapy followed by chemotherapy, the left ovarian lesion grew, so resection of the uterus and bilateral ovaries was performed. Adjuvant chemotherapy with tegafur-uracil (UFT)/calcium folinate (leucovorin, LV) was initiated. Seven months after resection of the ovarian lesion, brain metastases appeared in the bilateral frontal lobes and were treated with stereotactic Gamma Knife radiosurgery. Cervical and mediastinal lymph node metastases were also diagnosed, and irradiation of these lesions was performed. After radiotherapy, 10 courses of oxaliplatin and infused fluorouracil plus leucovorin (FOLFOX) were administered. During FOLFOX administration, recurrent left frontal lobe brain metastasis was diagnosed and treated with stereotactic Gamma Knife radiosurgery. In this case, the brain metastases were well treated with stereotactic Gamma Knife radiosurgery, and the systemic disease arising from sigmoid colon cancer has been kept under control with chemotherapies, surgical resection, and radiotherapy.

Evaluation of the stability of the stereotactic Leksell Frame G in Gamma Knife radiosurgery

The purpose of this study was to evaluate the stability of the Leksell Frame G in Gamma Knife radiosurgery (GKR). Forty patients undergoing GKR underwent pretreatment stereotactic MRI for GKR planning and stereotactic CT immediately after GKR. The stereotactic coordinates of four anatomical landmarks (cochlear apertures and the summits of the anterior post of the superior semicircular canals, bilaterally) were measured by two evaluators on two separate occasions in the pretreatment MRI and post‐treatment CT scans and the absolute distance between the observations is reported. The measurement method was validated with an independent group of patients who underwent both stereotactic MRI and CT imaging before treatment (negative controls; n: 5). Patients undergoing GKR for arteriovenous malformations (AVM) also underwent digital subtraction angiography (DSA), which could result in extra stresses on the frame. The distance between landmark localization in the scans for the negative control group (0.63 mm; 95% CI: 0.57–0.70; SD: 0.29) represents the overall consistency of the evaluation method and provides an estimate of the minimum displacement that could be detected by the study. Two patients in the study group had the fiducial indicator box accidentally misplaced at post‐treatment CT scanning. This simulated the scenario of a frame displacement, and these cases were used as positive controls to demonstrate that the evaluation method is capable of detecting a discrepancy between the MRI and CT scans, if there was one. The mean distance between the location of the landmarks in the pretreatment MRI and post‐treatment CT scans for the study group was 0.71 mm (95% CI: 0.68–0.74; SD:0.32), which was not statistically different from the overall uncertainty of the evaluation method observed in the negative control group (p=0.06). The subgroup of patients with AVM (n: 9), who also underwent DSA, showed a statistically significant difference between the location of the landmarks compared to subjects with no additional imaging: 0.78 mm (95% CI: 0.72–0.84) vs. 0.69 mm (95% CI: 0.66–0.72), p=0.016. This is however a minimal difference (0.1 mm) and the mean difference in landmark location for each AVM patient remained submillimeter. This study demonstrates submillimeter stability of the Leksell Frame G in GKR throughout the treatment procedure.

PACS number(s): 87.53.‐j, 87.53.Ly, 87.56.Fc

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.

Microstructural abnormalities of the trigeminal nerve by diffusion-tensor imaging in trigeminal neuralgia without neurovascular compression

Microstructural changes of the trigeminal nerve in trigeminal neuralgia due to neurovascular compression have been reported by using diffusion tensor imaging. Other aetiologies such as primary demyelinating lesions, brain stem infarction and nerve root infiltration by tumour affecting the trigeminal pathway may also present as trigeminal neuralgia. The aim of this study was to evaluate the microstructural tissue abnormalities in the trigeminal nerve in symptomatic trigeminal neuralgia not related to neurovascular compression using diffusion tensor imaging. Mean values of the quantitative diffusion parameters of trigeminal nerve, fractional anisotropy and apparent diffusion coefficient, were measured in a group of four symptomatic trigeminal neuralgia patients without neurovascular compression who showed focal non-enhancing T2-hyperintense lesions in the pontine trigeminal pathway. These diffusion parameters were compared between the affected and unaffected sides in the same patient and with four age-matched healthy controls. Cranial magnetic resonance imaging revealed hyperintense lesions in the dorsolateral part of the pons along the central trigeminal pathway on T2-fluid-attenuated inversion recovery sequences. The mean fractional anisotropy value on the affected side was significantly decreased (P = 0.001) compared to the unaffected side and healthy controls. Similarly, the mean apparent diffusion coefficient value was significantly higher (P = 0.001) on the affected side compared to the unaffected side and healthy controls. The cause of trigeminal neuralgia in our patients was abnormal pontine lesions affecting the central trigeminal pathway. The diffusion tensor imaging results suggest that microstructural tissue abnormalities of the trigeminal nerve also exist even in non-neurovascular compression-related trigeminal neuralgia.

Long-term evaluation of the effect of hypofractionated high-energy proton treatment of benign meningiomas by means of (11)C-L-methionine positron emission tomography

PURPOSE

To determine if (11)C-L-methionine PET is a useful tool in the evaluation of the long-term effect of proton beam treatment in patients with meningioma remnant.

METHODS

Included in the study were 19 patients (4 men, 15 women) with intracranial meningioma remnants who received hypofractionated high-energy proton beam treatment. Patients were examined with (11)C-L-methionine PET and MRI prior to treatment and after 6 months, and 1, 2, 3, 5, 7 and 10 years. Temporal changes in methionine uptake ratio, meningioma volume, meningioma regrowth and clinical symptoms throughout the follow-up period were evaluated.

RESULTS

In 17 patients the tumour volume was unchanged throughout the follow-up. The methionine uptake ratio on PET decreased over the years in most patients. In two patients the tumour remnant showed progression on MRI. In these patients, prior to the volume increase on MRI, the methionine uptake ratio increased. One patient experienced transient clinical symptoms and showed radiological evidence of a radiation-induced reaction close to the irradiated field.

CONCLUSION

Proton beam treatment is a safe and effective treatment for achieving long-term growth arrest in meningioma remnants. Follow-up with (11)C-L-methionine PET may be a valuable adjunct to, but not a replacement for, standard radiological follow-up.

Nonfunctioning giant pituitary adenomas: Invasiveness and recurrence

BACKGROUND

We report our surgical series of 35 patients with giant nonfunctioning pituitary adenomas (GNFPA). We analyzed the rule of Ki-67 antigen expression in predicting recurrence.

METHODS

Thirty-five patients were operated between 2000 and 2010. Suprassellar extension of the tumors were classified according to Hardy and Mohr based on magnetic resonance (MR) studies. Pituitary endocrine function and MR scans were assessed preoperatively and at 1, 6, and 12 months postoperatively. Immunohistochemical studies were based in regard to the expression of the proliferative Ki-67 index and the hormonal receptor for luteinizing hormone, follicle stimulating hormone, growth hormone, thyroid stimulating hormone, adrenocorticotropic hormone, and prolactin. Tumors specimens were obtained from 35 patients with GNFPA. Endoscopic transsphenoidal surgery was the approach of choice.

RESULTS

Thirty-five patients were submitted to 49 surgeries, 44 (89.8%) were transsphenoidal and 5 (10.2%) were transcranial. The most frequent preoperative complaints were visual acuity impairment and visual field defect in 25 (71.2%) and 23 (65.7%) cases, respectively. Improvement of visual acuitiy and visual field deficit after surgery was seen in 20 (80%) and 17 (73.9%) patients, respectively. Endocrinological deficits were encountered in 20 patients (57.1%). After surgery, 18 patients (51.4%) required hormonal replacement. Three patients had visual symptoms related to pituitary apoplexy and recovered after surgery. The Ki-67 labeling index (LI) ranged from <1% to 4.8%. The rate of recurrence in tumors with Ki-67 <3% was 7.7% (2 patients), Ki-67 >3% was present in 5 patients and the recurrence committed 3 patients.

CONCLUSION

In our series, regardless the improvement of visual function and compressing symptoms, 5 patients with expression of Ki-67 LI more than 3% experienced a recurrence.

Stereotactic Radiosurgery for Renal Cancer Brain Metastasis: Prognostic Factors and the Role of Whole-Brain Radiation and Surgical Resection

Background. Renal cell carcinoma is a frequent source of brain metastasis. We present our consecutive series of patients treated with Stereotactic Radiosurgery (SRS) and analyse prognostic factors and the interplay of WBRT and surgical resection. Methods. This is a retrospective study of 66 patients with 207 lesions treated with the Cyberknife radiosurgery system in our institution. The patients were followed up with imaging and clinical examination 1 month and 2-3 months thereafter for the brain metastasis. Patient, treatment, and outcomes characteristics were analysed. Results. 51 male (77.3%) and 15 female (22.7%) patients, with a mean age of 58.9 years (range of 31–85 years) and a median Karnofsky Performance Status (KPS) of 90 (range of 60–100), were included in the study. The overall survival was 13.9 months, 21.9 months, and 5.9 months for the patients treated with SRS only, additional surgery, and WBRT, respectively. The actuarial 1-year Local Control rates were 84%, 94%, and 88% for SRS only, for surgery and SRS, and for WBRT and additional SRS, respectively. Conclusions. Stereotactic radiosurgery is a safe and effective treatment option in patients with brain metastases from RCC. In case of a limited number of brain metastases, surgery and SRS might be appropriate.

Gamma Knife treatment of low-grade gliomas in children

BACKGROUND

Low-grade gliomas have good overall survival rates in pediatric patients compared to adults. There are some case series that reported the effectiveness and safety of Gamma Knife radiosurgery, yet they are limited in number of patients. We aimed to review the relevant literature for pediatric low-grade glial tumors treated with stereotactic radiosurgery, specifically Gamma Knife radiosurgery, and to present an exemplary case.

CASE DESCRIPTION

A 6-year-old boy was admitted to clinic due to head trauma. He was alert, cooperative, and had no obvious motor or sensorial deficit. A head CT scan depicted a hypodense zone at the right caudate nucleus. The brain magnetic resonance imaging (MRI) depicted a mass lesion at the same location. A stereotactic biopsy was performed. Histopathological diagnosis was low-grade astrocytoma (grade II, World Health Organization (WHO) classification, 2007). Gamma Knife radiosurgery was applied to the tumor bed. Tumor volume was 21.85 cm(3). Fourteen gray was given to 50% isodose segment of the lesion (maximal dose of 28 Gy). The tumor has disappeared totally in 4 months, and the patient was tumor-free 21 months after the initial treatment.

DISCUSSION AND CONCLUSION

The presented literature review represents mostly single-center experiences with different patient and treatment characteristics. Accordingly, a mean/median margin dose of 11.3-15 Gy with Gamma Knife radiosurgery (GKRS) is successful in treatment of pediatric and adult low-grade glial tumor patients. However, prospective studies with a large cohort of pediatric patients should be conducted to make a more comprehensive conclusion for effectiveness and safety of GKRS in pediatric low-grade glial tumors.

Pituitary adenomas: historical perspective, surgical management and future directions

Pituitary adenomas are among the most common central nervous system tumors. They represent a diverse group of neoplasms that may or may not secrete hormones based on their cell of origin. Epidemiologic studies have documented the incidence of pituitary adenomas within the general population to be as high as 16.7%. A growing body of work has helped to elucidate the pathogenesis of these tumors. Each subtype has been shown to demonstrate unique cellular changes potentially leading to tumorigenesis. Surgical advancements over several decades have included microsurgery and the employment of the endoscope for surgical resection. These advancements increase the likelihood of gross-total resection and have resulted in decreased patient morbidity.

Morphological changes after radiosurgery for mesial temporal lobe epilepsy

Background

To review our experience with morphological developments during the long-term follow-up of patients treated by Gamma Knife radiosurgery for mesial temporal lobe epilepsy.

Method

Between 1995 and 1999, we treated 14 patients with marginal doses of 24 Gy (n = 6) and 18–20 Gy (n = 8). Nine of these were operated on for insufficient seizure control. We reviewed seizure outcome and magnetic resonance images in both operated and unoperated patients and also re-examined histopathology specimens.

Results

Of the nine operated patients, two were Engel IIIA, one was IVA, five were IVB, and one was Engel IVC prior to surgery. At their final visit, five cases had become Engel class IA, one patient was ID, and two were IIC. In one patient the follow-up was not long enough for classification. Of the five unoperated patients, one was Engel class IB, one was IIIA, one IIB and one IVB at their final visit. Radionecrosis developed in 11 patients, occurring more often and earlier in those treated with higher doses. Collateral edema reached outside the temporal lobe in six patients, caused uncal herniation in two and intracranial hypertension in three. During longer follow-up, postnecrotic pseudocysts developed in 9 patients, and postcontrast enhancement persisted for 2.5–16 years after GKRS in all 14 patients. In five of them we detected its progression between 2 and 16 years after treatment. Signs of neoangiogenesis were found in two patients and microbleeds could be seen in five. Histopathology revealed blood vessel proliferation and macrophage infiltration.

Conclusions

Early delayed complications and morphological signs suggesting a risk of development of late delayed complications are frequent after radiosurgery for mesial temporal lobe epilepsy. Together with its unproven antiseizure efficacy, these issues should be taken into account when planning future studies of this method.

Electronic supplementary material

The online version of this article (doi:10.1007/s00701-015-2525-2) contains supplementary material, which is available to authorized users.

Stereotactic radiosurgery for brain metastasis in non-small cell lung cancer

Purpose

Stereotactic radiosurgery (SRS) has been introduced for small-sized single and oligo-metastases in the brain. The aim of this study is to assess treatment outcome, efficacy, and prognostic variables associated with survival and intracranial recurrence.

Materials and Methods

This study retrospectively reviewed 123 targets in 64 patients with non-small cell lung cancer (NSCLC) treated with SRS between January 2006 and December 2012. Treatment responses were evaluated using magnetic resonance imaging. Overall survival (OS) and intracranial progression-free survival (IPFS) were determined.

Results

The median follow-up was 13.9 months. The median OS and IPFS were 14.1 and 8.9 months, respectively. Fifty-seven patients died during the follow-up period. The 5-year local control rate was achieved in 85% of 108 evaluated targets. The 1- and 2-year OS rates were 55% and 28%, respectively. On univariate analysis, primary disease control (p < 0.001), the Eastern Cooperative Oncology Group (ECOG) performance status (0-1 vs. 2; p = 0.002), recursive partitioning analysis class (1 vs. 2; p = 0.001), and age (<65 vs. ≥65 years; p = 0.036) were significant predictive factors for OS. Primary disease control (p = 0.041) and ECOG status (p = 0.017) were the significant prognostic factors for IPFS. Four patients experienced radiation necrosis.

Conclusion

SRS is a safe and effective local treatment for brain metastases in patients with NSCLC. Uncontrolled primary lung disease and ECOG status were significant predictors of OS and intracranial failure. SRS might be a tailored treatment option along with careful follow-up of the intracranial and primary lung disease status.

Multi-modality management of craniopharyngioma: a review of various treatments and their outcomes

Craniopharyngioma is a rare tumor that is expected to occur in ∼400 patients/year in the United States. While surgical resection is considered to be the primary treatment when a patient presents with a craniopharyngioma, only 30% of such tumors present in locations that permit complete resection. Radiotherapy has been used as both primary and adjuvant therapy in the treatment of craniopharyngiomas for over 50 years. Modern radiotherapeutic techniques, via the use of CT-based treatment planning and MRI fusion, have permitted tighter treatment volumes that allow for better tumor control while limiting complications. Modern radiotherapeutic series have shown high control rates with lower doses than traditionally used in the two-dimensional treatment era. Intracavitary radiotherapy with radio-isotopes and stereotactic radiosurgery may have a role in the treatment of recurrent cystic and solid recurrences, respectively. Recently, due to the exclusive expression of the Beta-catenin clonal mutations and the exclusive expression of BRAF V600E clonal mutations in the overwhelming majority of adamantinomatous and papillary tumors respectively, it is felt that inhibitors of each pathway may play a role in the future treatment of these rare tumors.

Isolation, characterization, and antibiotic resistance of Vibrio spp. in sea turtles from Northwestern Mexico

The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh⁺ gene) and 2/17 (11.7%) had the pandemic clone (tdh⁺ and toxRS/new⁺). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.

Marketed nonsteroidal anti-inflammatory agents, antihypertensives, and human immunodeficiency virus protease inhibitors: as-yet-unused weapons of the oncologists' arsenal

Experimental data indicate that several pharmacological agents that have long been used for the management of various diseases unrelated to cancer exhibit profound in vitro and in vivo anticancer activity. This is of major clinical importance, since it would possibly aid in reassessing the therapeutic use of currently used agents for which clinicians already have experience. Further, this would obviate the time-consuming process required for the development and the approval of novel antineoplastic drugs. Herein, both pre-clinical and clinical data concerning the antineoplastic function of distinct commercially available pharmacological agents that are not currently used in the field of oncology, ie, nonsteroidal anti-inflammatory drugs, antihypertensive agents, and anti-human immunodeficiency virus agents inhibiting viral protease, are reviewed. The aim is to provide integrated information regarding not only the molecular basis of the antitumor function of these agents but also the applicability of the reevaluation of their therapeutic range in the clinical setting.

Indirect Tumor Cell Death After High-Dose Hypofractionated Irradiation: Implications for Stereotactic Body Radiation Therapy and Stereotactic Radiation Surgery

PURPOSE

The purpose of this study was to reveal the biological mechanisms underlying stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS).

METHODS AND MATERIALS

FSaII fibrosarcomas grown subcutaneously in the hind limbs of C3H mice were irradiated with 10 to 30 Gy of X rays in a single fraction, and the clonogenic cell survival was determined with in vivo--in vitro excision assay immediately or 2 to 5 days after irradiation. The effects of radiation on the intratumor microenvironment were studied using immunohistochemical methods.

RESULTS

After cells were irradiated with 15 or 20 Gy, cell survival in FSaII tumors declined for 2 to 3 days and began to recover thereafter in some but not all tumors. After irradiation with 30 Gy, cell survival declined continuously for 5 days. Cell survival in some tumors 5 days after 20 to 30 Gy irradiation was 2 to 3 logs less than that immediately after irradiation. Irradiation with 20 Gy markedly reduced blood perfusion, upregulated HIF-1α, and increased carbonic anhydrase-9 expression, indicating that irradiation increased tumor hypoxia. In addition, expression of VEGF also increased in the tumor tissue after 20 Gy irradiation, probably due to the increase in HIF-1α activity.

CONCLUSIONS

Irradiation of FSaII tumors with 15 to 30 Gy in a single dose caused dose-dependent secondary cell death, most likely by causing vascular damage accompanied by deterioration of intratumor microenvironment. Such indirect tumor cell death may play a crucial role in the control of human tumors with SBRT and SRS.

Diagnosis and evaluation of intracranial arteriovenous malformations

BACKGROUND

Ideal management of intracranial arteriovenous malformations (AVMs) remains poorly defined. Decisions regarding management of AVMs are based on the expected natural history of the lesion and risk prediction for peritreatment morbidity. Microsurgical resection, stereotactic radiosurgery, and endovascular embolization alone or in combination are all viable treatment options, each with different risks. The authors attempt to clarify the existing literature's understanding of the natural history of intracranial AVMs, and risk-assessment grading scales for each of the three treatment modalities.

METHODS

The authors conducted a literature review of the existing AVM natural history studies and studies that clarify the utility of existing grading scales available for the assessment of peritreatment risk for all three treatment modalities.

RESULTS

The authors systematically outline the diagnosis and evaluation of patients with intracranial AVMs and clarify estimation of the expected natural history and predicted risk of treatment for intracranial AVMs.

CONCLUSION

AVMs are a heterogenous pathology with three different options for treatment. Accurate assessment of risk of observation and risk of treatment is essential for achieving the best outcome for each patient.

Clinical and Radiologic Outcome of Gamma Knife Radiosurgery on Nonfunctioning Pituitary Adenomas

Objective To elucidate the role of Gamma Knife radiosurgery (GKRS) in the management of nonfunctioning pituitary adenomas (NFAs). Materials and Methods A retrospective review of 57 consecutive patients spanning 2000 to 2013 with NFAs was performed. Of 57 patients, 53 patients had recurrent or residual tumors after microsurgical resection. The study population was evaluated clinically and radiographically after GKRS treatment. The median follow-up time was 45.57 months. Results GKRS in pituitary adenomas showed significant variations in tumor growth control (decreased in 32 patients [56.1%], arrested growth in 21 patients [36.1%], and increased tumor size in 4 patients [7%]). Progression-free survival after GKRS at 3, 7, and 10 years was 100%, 98%, and 90%, respectively. The neurologic signs and symptoms were significantly improved after GKRS (14% versus 107%) compared with pretreated signs and symptoms (p < 0.0001). Five patients (8.8%) required additional treatment. Conclusion Recent follow-up revealed that GKRS offers a high rate of tumor control and preservation of neurologic functions in both new and recurrent patients with NFAs. Thus GKRS is an effective treatment option for recurrent and residual as well as newly diagnosed patients with NFAs.

Characteristics and treatments of large cystic brain metastasis: radiosurgery and stereotactic aspiration

Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes.

Application of radiosurgical techniques to produce a primate model of brain lesions

Behavioral analysis of subjects with discrete brain lesions provides important information about the mechanisms of various brain functions. However, it is generally difficult to experimentally produce discrete lesions in deep brain structures. Here we show that a radiosurgical technique, which is used as an alternative treatment for brain tumors and vascular malformations, is applicable to create non-invasive lesions in experimental animals for the research in systems neuroscience. We delivered highly focused radiation (130-150 Gy at ISO center) to the frontal eye field (FEF) of macaque monkeys using a clinical linear accelerator (LINAC). The effects of irradiation were assessed by analyzing oculomotor performance along with magnetic resonance (MR) images before and up to 8 months following irradiation. In parallel with tissue edema indicated by MR images, deficits in saccadic and smooth pursuit eye movements were observed during several days following irradiation. Although initial signs of oculomotor deficits disappeared within a month, damage to the tissue and impaired eye movements gradually developed during the course of the subsequent 6 months. Postmortem histological examinations showed necrosis and hemorrhages within a large area of the white matter and, to a lesser extent, in the adjacent gray matter, which was centered at the irradiated target. These results indicated that the LINAC system was useful for making brain lesions in experimental animals, while the suitable radiation parameters to generate more focused lesions need to be further explored. We propose the use of a radiosurgical technique for establishing animal models of brain lesions, and discuss the possible uses of this technique for functional neurosurgical treatments in humans.

Is stereotactic radiosurgery a rational treatment option for brain metastases from small cell lung cancer? A retrospective analysis of 70 consecutive patients

Background

Because of the high likelihood of multiple brain metastases (BM) from small cell lung cancer (SCLC), the role of focal treatment using stereotactic radiosurgery (SRS) has yet to be determined. We aimed to evaluate the efficacy and limitations of upfront and salvage SRS for patients with BM from SCLC.

Methods

This was a retrospective and observational study analyzing 70 consecutive patients with BM from SCLC who received SRS. The median age was 68 years, and the median Karnofsky performance status (KPS) was 90. Forty-six (66%) and 24 (34%) patients underwent SRS as the upfront and salvage treatment after prophylactic or therapeutic whole brain radiotherapy (WBRT), respectively. Overall survival (OS), neurological death-free survival, remote and local tumor recurrence rates were analyzed.

Results

None of our patients were lost to follow-up and the median follow-up was 7.8 months. One-and 2-year OS rates were 43% and 15%, respectively. The median OS time was 7.8 months. One-and 2-year neurological death-free survival rates were 94% and 84%, respectively. In total, 219/292 tumors (75%) in 60 patients (86 %) with sufficient radiological follow-up data were evaluated. Six-and 12-month rates of remote BM relapse were 25% and 47%, respectively. Six-and 12-month rates of local control failure were 4% and 23%, respectively. Repeat SRS, salvage WBRT and microsurgery were subsequently required in 30, 8 and one patient, respectively. Symptomatic radiation injury, treated conservatively, developed in 3 patients.

Conclusions

The present study suggested SRS to be a potentially effective and minimally invasive treatment option for BM from SCLC either alone or after failed WBRT. Although repeat salvage treatment was needed in nearly half of patients to achieve control of distant BM, such continuation of radiotherapeutic management might contribute to reducing the rate of neurological death.