Evaluation of Linear Accelerator-based Stereotactic Radiosurgery in the Management of Glomus Jugulare Tumors

Aims and Background

Although mostly benign and slow-growing, glomus jugulare tumors have a high propensity for local invasion of adjacent vascular structures, lower cranial nerves and the inner ear, which may result in substantial morbidity and even mortality. Treatment strategies for glomus jugulare tumors include surgery, preoperative embolization followed by surgical resection, conventionally fractionated external beam radiotherapy, radiosurgery in the form of stereotactic radiosurgery or fractionated stereotactic radiation therapy, and combinations of these modalities. In the present study, we evaluate the use of linear accelerator (LINAC)-based stereotactic radiosurgery in the management of glomus jugulare tumors and report our 15-year single center experience.

Methods and Study Design

Between May 1998 and May 2013, 21 patients (15 females, 6 males) with glomus jugulare tumors were treated using LINAC-based stereotactic radiosurgery at the Department of Radiation Oncology, Gulhane Military Medical Academy. The indication for stereotactic radiosurgery was the presence of residual or recurrent tumor after surgery for 5 patients, whereas 16 patients having growing tumors with symptoms received stereotactic radiosurgery as the primary treatment.

Results

Median follow-up was 49 months (range, 3–98). Median age was 55 years (range, 24–77). Of the 21 lesions treated, 13 (61.9%) were left-sided and 8 (38.1%) were right-sided. Median dose was 15 Gy (range, 10–20) prescribed to the 85%-100% isodose line encompassing the target volume. Local control defined as either tumor shrinkage or the absence of tumor growth on periodical follow-up neuroimaging was 100%.

Conclusions

LINAC-based stereotactic radiosurgery offers a safe and efficacious management strategy for glomus jugulare tumors by providing excellent tumor growth control with few complications.

Management of Vestibular Schwannomas with Linear Accelerator-Based Stereotactic Radiosurgery: A Single Center Experience

Aims and background

The primary goal of treatment for vestibular schwannoma is to achieve local control without comprimising regional cranial nerve function. Stereotactic radiosurgery has emerged as a viable therapeutic option for vestibular schwannoma. The aim of the study is to report our 15-year single center experience using linear accelerator-based stereotactic radiosurgery in the management of patients with vestibular schwannoma.

Methods and study design

Between July 1998 and January 2013, 68 patients with unilateral vestibular schwannoma were treated using stereotactic radiosurgery at the Department of Radiation Oncology, Gulhane Military Medical Academy. All patients underwent high-precision stereotactic radiosurgery using a linear accelerator with 6-MV photons.

Results

Median follow-up time was 51 months (range, 9–107). Median age was 45 years (range, 20–77). Median dose was 12 Gy (range, 10–13) prescribed to the 85%-95% isodose line encompassing the target volume. Local tumor control in patients with periodic follow-up imaging was 96.1%. Overall hearing preservation rate was 76.5%.

Conclusions

Linear accelerator-based stereotactic radiosurgery offers a safe and effective treatment for patients with vestibular schwannoma by providing high local control rates along with improved quality of life through well-preserved hearing function.

Image-Guided Positioning in Intracranial Non-Invasive Stereotactic Radiosurgery for the Treatment of Brain Metastasis

Aims and background

The aim of the study was to examine the feasibility of non-invasive image-guided radiosurgery to improve patient comfort and quality of life in stereotactic radiosurgery planning and treatment of patients with brain metastasis. Precise immobilization is a rule of thumb for stereotactic radiosurgery. Non-invasive immobilization techniques have the potential of improved quality of life compared with invasive procedures.

Methods and study design

A total of 92 lesions from 42 patients with brain metastasis were included in the study. After immobilization with a thermoplastic mask and a bite-block unlike the invasive frame-based procedure, planning computed tomography images were acquired and fused with magnetic resonance images. After contouring, intensity-modulated stereotactic radiosurgery (IM-SRS) planning was done, and the patients were re-immobilized on the treatment couch for the therapy procedures. While patients were on the treatment couch, kilovoltage-cone beam computed tomography images were acquired to determine setup errors and achieve on-line correction and then repeated after on-line correction to confirm precise tumor localization. The patients then underwent single-fraction definitive treatment.

Results

For the 92 lesions treated, mean ± SD values of translational setup corrections in X (lateral), Y (longitudinal), and Z (vertical) dimensions were 0.7 ± 0.7 mm, 0.8 ± 0.7 mm, and 0.6 ± 0.5 mm, and rotational set-up corrections were 0.5 ± 1.1°, 0.06 ± 1.1°, and -0.1 ± 1.1° in X (pitch), Y (roll), and Z (yaw), respectively. The mean three-dimensional correction vector was 1.2 ± 1.1 mm.

Conclusions

Non-invasive image-guided radiosurgery for brain metastasis is feasible, and the non-invasive treatment approach can be routinely used in clinical practice to improve patientís quality of life.

[Intraocular Tumors other than Retinoblastoma in Children]

The diagnosis of an intraocular mass in children can be challenging as invasive procedures are not allowed, in particular if a retinoblastoma may be present. In eyes with a unilateral tumour mass and loss of function enucleation with subsequent histopathological processing might be the only option to establish a diagnosis and to exclude a malignant tumour. The present paper deals with intraocular tumours other than retinoblastoma in children, with a special focus on the correlation of modern imaging techniques and histopathological findings.

Management of patients with ≥4 brain metastases using stereotactic radiosurgery boost after whole brain irradiation

AIMS AND BACKGROUND

Brain metastases are a prevalent consequence of systemic cancer, and patients suffering from brain metastases usually present with multiple metastatic lesions. An overwhelming majority of the available literature assessing the role of stereotactic radiosurgery in brain metastasis management includes patients with up to 4 metastases. Given the significant benefit of stereotactic radiosurgery for the treatment of 1 to 3 brain metastases, we evaluated the use of stereotactic radiosurgery boost after whole brain irradiation in the management of patients with ≥4 brain metastases.

METHODS

In this retrospective analysis, outcomes of 50 patients who underwent linear accelerator-based stereotactic radiosurgery boost within 4 to 6 weeks of whole brain irradiation for ≥4 brain metastases were assessed in terms of local control, overall survival, primary involved organ, recursive partitioning analysis class and Karnofsky performance status at the time of stereotactic radiosurgery, number of lesions, age, status of the primary cancer (controlled vs uncontrolled), presence of extracranial disease and toxicity.

RESULTS

Fifty patients with ≥4 brain metastases were treated using linear accelerator-based stereotactic radiosurgery boost after whole brain irradiation between April 1998 and April 2013. Mean and median number of intracranial lesions was 6.02 and 6, respectively. Median lesion volume was 10.9 cc (range, 0.05-32.6). Median survival time after radiosurgery was 10.1 months (range, 1-25). Status of the primary cancer (controlled vs uncontrolled), recursive partitioning analysis class, Karnofsky performance status, and extracranial metastasis showed statistically significant correlations with overall survival (P <0.001). Treatment-related side effects after stereotactic radiosurgery included temporary edema (n = 14, 28%), hemiparesis (n = 1, 2%), seizure (n = 1, 2%), leukoencephalopathy (n = 2, 4%), and radiation necrosis (n = 6, 12%).

CONCLUSIONS

Linear accelerator-based stereotactic radiosurgery boost within 4 to 6 weeks after whole brain irradiation proved to be an efficacious and well-tolerated treatment strategy for the management of patients with ≥4 brain metastases in our study.

Evaluation of linear accelerator-based stereotactic radiosurgery in the management of glomus jugulare tumors

AIMS AND BACKGROUND

Although mostly benign and slow-growing, glomus jugulare tumors have a high propensity for local invasion of adjacent vascular structures, lower cranial nerves and the inner ear, which may result in substantial morbidity and even mortality. Treatment strategies for glomus jugulare tumors include surgery, preoperative embolization followed by surgical resection, conventionally fractionated external beam radiotherapy, radiosurgery in the form of stereotactic radiosurgery or fractionated stereotactic radiation therapy, and combinations of these modalities. In the present study, we evaluate the use of linear accelerator (LINAC)-based stereotactic radiosurgery in the management of glomus jugulare tumors and report our 15-year single center experience.

METHODS AND STUDY DESIGN

Between May 1998 and May 2013, 21 patients (15 females, 6 males) with glomus jugulare tumors were treated using LINAC-based stereotactic radiosurgery at the Department of Radiation Oncology, Gulhane Military Medical Academy. The indication for stereotactic radiosurgery was the presence of residual or recurrent tumor after surgery for 5 patients, whereas 16 patients having growing tumors with symptoms received stereotactic radiosurgery as the primary treatment.

RESULTS

Median follow-up was 49 months (range, 3-98). Median age was 55 years (range, 24-77). Of the 21 lesions treated, 13 (61.9%) were left-sided and 8 (38.1%) were right-sided. Median dose was 15 Gy (range, 10-20) prescribed to the 85%-100% isodose line encompassing the target volume. Local control defined as either tumor shrinkage or the absence of tumor growth on periodical follow-up neuroimaging was 100%.

CONCLUSIONS

LINAC-based stereotactic radiosurgery offers a safe and efficacious management strategy for glomus jugulare tumors by providing excellent tumor growth control with few complications.

Evaluation of linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) for cerebral cavernous malformations: a 15-year single-center experience

BACKGROUND AND OBJECTIVES

Surgery is the principal treatment for safely accessible hemorrhagic and symptomatic cavernous malformations. Nevertheless, the role of linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) in the management of high-risk, symptomatic cavernoma lesions warrants further refinement. In this study, we evaluate the use of LINAC-based SRS for cerebral cavernous malformations (CMs) and report our 15-year single-center experience.

DESIGN AND SETTINGS

A retrospective study from the Department of Radiation Oncology and the Department of Neurosurgery at Gulhane Military Medical Academy and Medical Faculty, Ankara from April 1998 to June 2013.

PATIENTS AND METHODS

Fifty-two patients (22 females and 30 males) with cerebral CM referred to our department underwent high-precision single-dose SRS using a LINAC with 6-MV photons. All patients had at least 1 bleeding episode prior to radiosurgery along with related symptoms. Median dose prescribed to the 85% to 95% isodose line encompassing the target volume was 15 Gy (range, 10-20).

RESULTS

Out of the total 52 patients, follow-up data were available for 47 patients (90.4%). Median age was 35 years (range, 19-63). Median follow-up time was 5.17 years (range, 0.08-9.5) after SRS. Three hemorrhages were identified in the post-SRS period. Statistically significant decrease was observed in the annual hemorrhage rate after radiosurgical treatment (pre-SRS 39% vs post-SRS 1.21, P < .0001). Overall, there were no radiosurgery-related complications resulting in mortality.

CONCLUSION

LINAC-based SRS may be considered as a treatment option for high-risk, symptomatic cerebral CM of selected patients with prior bleeding from lesions located at surgically inaccessible or eloquent brain areas.

Management of vestibular schwannomas with linear accelerator-based stereotactic radiosurgery: a single center experience

AIMS AND BACKGROUND

The primary goal of treatment for vestibular schwannoma is to achieve local control without comprimising regional cranial nerve function. Stereotactic radiosurgery has emerged as a viable therapeutic option for vestibular schwannoma. The aim of the study is to report our 15-year single center experience using linear accelerator-based stereotactic radiosurgery in the management of patients with vestibular schwannoma.

METHODS AND STUDY DESIGN

Between July 1998 and January 2013, 68 patients with unilateral vestibular schwannoma were treated using stereotactic radiosurgery at the Department of Radiation Oncology, Gulhane Military Medical Academy. All patients underwent high-precision stereotactic radiosurgery using a linear accelerator with 6-MV photons.

RESULTS

Median follow-up time was 51 months (range, 9-107). Median age was 45 years (range, 20-77). Median dose was 12 Gy (range, 10-13) prescribed to the 85%-95% isodose line encompassing the target volume. Local tumor control in patients with periodic follow-up imaging was 96.1%. Overall hearing preservation rate was 76.5%.

CONCLUSIONS

Linear accelerator-based stereotactic radiosurgery offers a safe and effective treatment for patients with vestibular schwannoma by providing high local control rates along with improved quality of life through well-preserved hearing function.

Association of aneurysms and variation of the A1 segment

BACKGROUND AND PURPOSE

Previous studies have described a correlation between variants of the circle of Willis and pathological findings, such as cerebrovascular diseases. Moreover, anatomic variations of the anterior cerebral artery (ACA) seem to correspond to the prevalence of aneurysms in the anterior communicating artery (ACoA). The aim of this study was to assess the prevalence of aneurysms in patients with anatomical/morphological variations of the circle of Willis.

METHODS

We retrospectively analyzed 223 patients who underwent cerebral angiography between January 2002 and December 2010 for aneurysm of the ACoA. Diagnostic imaging was reviewed and statistically evaluated to detect circle of Willis anomalies, aneurysm size, and rupture. 204 patients with an unrelated diagnosis served as the control group.

RESULTS

Variations of the A1 segment occurred significantly more frequently in the aneurysm group than in the control group. Mean aneurysm size in patients with grades I and III hypoplasia or aplasia was 6.58 mm whereas in patients with grade II hypoplasia it was 7.76 mm.

CONCLUSIONS

We found that variations in the A1 segment of the ACAs are correlated with a higher prevalence of ACoA aneurysms compared with patients with a symmetric circle of Willis.

Image-guided positioning in intracranial non-invasive stereotactic radiosurgery for the treatment of brain metastasis

AIMS AND BACKGROUND

The aim of the study was to examine the feasibility of non-invasive image-guided radiosurgery to improve patient comfort and quality of life in stereotactic radiosurgery planning and treatment of patients with brain metastasis. Precise immobilization is a rule of thumb for stereotactic radiosurgery. Non-invasive immobilization techniques have the potential of improved quality of life compared with invasive procedures.

METHODS AND STUDY DESIGN

A total of 92 lesions from 42 patients with brain metastasis were included in the study. After immobilization with a thermoplastic mask and a bite-block unlike the invasive frame-based procedure, planning computed tomography images were acquired and fused with magnetic resonance images. After contouring, intensity-modulated stereotactic radiosurgery (IM-SRS) planning was done, and the patients were re-immobilized on the treatment couch for the therapy procedures. While patients were on the treatment couch, kilovoltage-cone beam computed tomography images were acquired to determine setup errors and achieve on-line correction and then repeated after on-line correction to confirm precise tumor localization. The patients then underwent single-fraction definitive treatment.

RESULTS

For the 92 lesions treated, mean ± SD values of translational setup corrections in X (lateral), Y (longitudinal), and Z (vertical) dimensions were 0.7 ± 0.7 mm, 0.8 ± 0.7 mm, and 0.6 ± 0.5 mm, and rotational set-up corrections were 0.5 ± 1.1°, 0.06 ± 1.1°, and -0.1 ± 1.1° in X (pitch), Y (roll), and Z (yaw), respectively. The mean three-dimensional correction vector was 1.2 ± 1.1 mm.

CONCLUSIONS

Non-invasive image-guided radiosurgery for brain metastasis is feasible, and the non-invasive treatment approach can be routinely used in clinical practice to improve patients' quality of life.

Multistaged volumetric management of large arteriovenous malformations

We sought to define the long-term outcomes and risks of arteriovenous malformation (AVM) management using 2 or more stages of stereotactic radiosurgery (SRS) for symptomatic large-volume AVMs unsuitable for surgery. Two decades ago, we prospectively began to stage anatomical components in order to deliver higher single doses to AVMs>10 cm3 in volume. Forty-seven patients with large AVMs underwent volume-staged SRS. The median interval between the two SRS procedures was 4.9 months (range, 3-14 months). The median nidus volume was 11.5 cm3 (range, 4.0-26 cm3) in the first stage of SRS and 9.5 cm3 in the second. The median margin dose was 16 Gy (range, 13-18 Gy) for both SRS stages. The actuarial rates of total obliteration after 2-staged SRS were 7, 20, 28 and 36% at 3, 4, 5 and 10 years, respectively. Sixteen patients needed additional SRS at a median interval of 61 months (range, 33-113 months) after the 2-staged SRS. After repeat procedure(s), the eventual obliteration rate was 66% at 10 years. The cumulative rates of AVM hemorrhage after SRS were 4.3, 8.6, 13.5 and 36.0% at 1, 2, 5 and 10 years, respectively. Symptomatic adverse radiation effects were detected in 13% of patients. Successful prospective volume-staged SRS for large AVMs unsuitable for surgery requires 2 or more procedures to complete the obliteration process. Patients remain at risk for hemorrhage if the AVM persists.

The effects of low-dose radiation in the treatment of sciatic nerve injury in rats

AIM

Peripheral nerve regeneration is often blocked by scar formation and misdirection of axon sprouts. The aim of this study is to evaluate electrophysiological and histopathological effects of low-dose radiation therapy on the prevention of intraneural scar formation in peripheral nerve injury.

MATERIAL AND METHODS

In this experimental study, twenty rats were randomly divided into two groups. Left sciatic nerves were exposed and clipped by temporary aneurysm clip for 5 minutes in both groups. In all animals, electrophysiological recordings were performed between 22-24 hours after sciatic nerve injury. The control group was not given any treatment. In the experimental group, 700 cGy low-dose radiation was administered on the left sciatic nerves 24 hours after clipping. Six weeks after injury, electrophysiological recordings were performed in both groups and animals were sacrificed to evaluate the injured nerves histopathologically.

RESULTS

We observed that low-dose radiotherapy increased the amplitude and improved latency measurements in electrophysiological examinations. Histopathologically, more axonal degeneration and vacuolization was observed in the control group comparing with the experimental group. Endoneural space increased slightly more in the control group than the experimental group.

CONCLUSION

It was observed that low-dose radiotherapy may prevent intraneural scar formation and may improve electrophysiological recovery in sciatic nerve injury performed in rats.

Stereotactic radiosurgery for arteriovenous malformations, Part 6: multistaged volumetric management of large arteriovenous malformations

Object

The object of this study was to define the long-term outcomes and risks of arteriovenous malformation (AVM) management using 2 or more stages of stereotactic radiosurgery (SRS) for symptomatic large-volume lesions unsuitable for surgery.

Methods

In 1992, the authors prospectively began to stage the treatment of anatomical components to deliver higher single doses to AVMs with a volume of more than 10 cm3. Forty-seven patients with such AVMs underwent volume-staged SRS. In this series, 18 patients (38%) had a prior hemorrhage and 21 patients (45%) underwent prior embolization. The median interval between the first-stage SRS and the second-stage SRS was 4.9 months (range 2.8–13.8 months). The median target volume was 11.5 cm3 (range 4.0–26 cm3) in the first-stage SRS and 9.5 cm3 in the second-stage SRS. The median margin dose was 16 Gy (range 13–18 Gy) for both stages.

Results

In 17 patients, AVM obliteration was confirmed after 2–4 SRS procedures at a median follow-up of 87 months (range 0.4–209 months). Five patients had near-total obliteration (volume reduction > 75% but residual AVM). The actuarial rates of total obliteration after 2-stage SRS were 7%, 20%, 28%, and 36% at 3, 4, 5, and 10 years, respectively. The 5-year total obliteration rate after the initial staged volumetric SRS with a margin dose of 17 Gy or more was 62% (p = 0.001). Sixteen patients underwent additional SRS at a median interval of 61 months (range 33–113 months) after the initial 2-stage SRS. The overall rates of total obliteration after staged and repeat SRS were 18%, 45%, and 56% at 5, 7, and 10 years, respectively. Ten patients sustained hemorrhage after staged SRS, and 5 of these patients died. Three of 16 patients who underwent repeat SRS sustained hemorrhage after the procedure and died. Based on Kaplan-Meier analysis (excluding the second hemorrhage in the patient who had 2 hemorrhages), the cumulative rates of AVM hemorrhage after SRS were 4.3%, 8.6%, 13.5%, and 36.0% at 1, 2, 5, and 10 years, respectively. This corresponded to annual hemorrhage risks of 4.3%, 2.3%, and 5.6% for Years 0–1, 1–5, and 5–10 after SRS. Multiple hemorrhages before SRS correlated with a significantly higher risk of hemorrhage after SRS. Symptomatic adverse radiation effects were detected in 13% of patients, but no patient died as a result of an adverse radiation effect. Delayed cyst formation did not occur in any patient after SRS.

Conclusions

Prospective volume-staged SRS for large AVMs unsuitable for surgery has potential benefit but often requires more than 2 procedures to complete the obliteration process. To have a reasonable chance of benefit, the minimum margin dose should be 17 Gy or greater, depending on the AVM location. In the future, prospective volume-staged SRS followed by embolization (to reduce flow, obliterate fistulas, and occlude associated aneurysms) may improve obliteration results and further reduce the risk of hemorrhage after SRS.

Is spontaneous spinal epidural hematoma in elderly patients an emergency surgical case?

Spontaneous spinal epidural hematoma (SSEH) is a rare condition requiring urgent diagnosis and treatment. Patients with SSEH typically present with acute onset of severe back pain and rapidly develop signs of compression of the spinal cord. The authors present a case with spontaneous resolution of SSEH which is extremely rare. We discuss a man who presented to our clinic with mild paraparesis at the seventh day of his symptoms. He had a history of poorly controlled hypertension and hypercholestrolemia requiring an antihyperlipidemic agent and anticoagulation. His upper level of hypoesthesia was at the third thoracic segment. Cervicothoracic SSEH was diagnosed by magnetic resonance imaging. Since there was a gradual recovery of the neurological deficits beginning 12 hours after the onset of symptoms, surgery was obviated and strict bed rest, serial neurological examinations, and pain controls with opiates were instituted. The neurological deficits showed complete recovery on the 25th day of the clinical course. SSEH is rare and immediate surgical decompression is suggested. Rapid neurological deterioration followed by early and progressive neurological recovery, confirmed by radiological resolution of the lesion, may indicate nonoperative treatment.

The evaluation of surgical treatment options in the Chiari Malformation Type I

AIM

There have been several treatment modalities to reduce the volume of the syringomyelic cavity and the pressure on the brainstem in Chiari Malformation Type I (CM-I). Foramen magnum decompression with and without duroplasty were compared in this retrospective study.

MATERIAL AND METHODS

From 2003 to 2006, 27 patients suffering from CMI were operated on at our institute. The following were measured: the ratio of the syringomyelic cavity to the spinal cord; pre-operative tonsillar herniation from the foramen magnum; pre- and postoperative tonsillo-dural distance; and spinoposterior fossa dural angle.

RESULTS

83.3 % of the patients in the non-duroplasty and 73.3% of the patients in the duroplasty group were symptom free. The ratio of syrinx regression was 28+/-10% in the non-duroplasty and 36+/-33% in the duroplasty group. The tonsillodural distance was 3.1+/-1.8 mm in the non-duroplasty and 4.6+/-2.1 mm in the duroplasty group (p>0.05). The spino-posterior fossa dural angle was 133.6+/-9.44 degrees preoperatively and 136.7+/-9.78 degrees postoperatively in the non-duroplasty (p=0.376); 123.7+/-11.7 degrees preoperatively and 129.8+/-11.1 degrees postoperatively in the duroplasty group (p=0.885); no significant difference was found postoperatively (p=0.55, z=1.92), respectively. One patient was re-operated in the non-duroplasty group and thereafter duroplasty was performed.

CONCLUSION

Almost the same clinical outcomes can be achieved with and without duroplasty. There might be an option to perform duroplasty if simple procedure fails.

A modified radiosurgery-based arteriovenous malformation grading scale and its correlation with outcomes

PURPOSE

The Pittsburgh radiosurgery-based arteriovenous malformation (AVM) grading scale was developed to predict patient outcomes after radiosurgery and was later modified with location as a two-tiered variable (deep vs. other). The purpose of this study was to test the modified radiosurgery-based AVM score in a separate set of AVM patients managed with radiosurgery.

METHODS AND MATERIALS

The AVM score is calculated as follows: AVM score = (0.1)(volume, cc) + (0.02)(age, years) + (0.5)(location; frontal/temporal/parietal/occipital/intraventricular/corpus callosum/cerebellar = 0, basal ganglia/thalamus/brainstem = 1). Testing of the modified system was performed on 293 patients having AVM radiosurgery from 1992 to 2004 at the University of Pittsburgh with dose planning based on a combination of stereotactic angiography and MRI. The median patient age was 38 years, the median AVM volume was 3.3 cc, and 57 patients (19%) had deep AVMs. The median modified AVM score was 1.25. The median patient follow-up was 39 months.

RESULTS

The modified AVM scale correlated with the percentage of patients with AVM obliteration without new deficits (≤1.00, 62%; 1.01-1.50, 51%; 1.51-2.00, 53%; and >2.00, 32%; F = 11.002, R(2) = 0.8117, p = 0.001). Linear regression also showed a statistically significant correlation between outcome and dose prescribed to the margin (F = 25.815, p <0.001).

CONCLUSIONS

The modified radiosurgery-based AVM grading scale using location as a two-tiered variable correlated with outcomes when tested on a cohort of patients who underwent both angiography and MRI for dose planning. This system can be used to guide choices among observation, endovascular, surgical, and radiosurgical management strategies for individual AVM patients.

Long-term control of petroclival meningiomas through radiosurgery

OBJECT

Because of their critical location adjacent to brain, cranial nerve, and vascular structures, petroclival meningiomas remain a clinical challenge. The authors evaluated outcomes in 168 patients with petroclival meningiomas who underwent Gamma Knife surgery (GKS) during a 21-year interval.

METHODS

Gamma Knife surgery was used as either primary or adjuvant treatment of 168 petroclival meningiomas involving the region between the petrous apex and the upper two-thirds of the clivus. The most common presenting symptoms were trigeminal nerve dysfunction, balance problems, diplopia, and hearing loss. The median tumor volume was 6.1 cm3 (range 0.3-32.5 cm3), and the median radiation dose to the tumor margin was 13 Gy (range 9-18 Gy).

RESULTS

During a median follow-up of 72 months, neurological status improved in 44 patients (26%), remained stable in 98 (58%), and worsened in 26 (15%). Tumor volume decreased in 78 patients (46%), remained stable in 74 (44%), and increased in 16 (10%), all of whom were subjected to additional management strategies. Overall 5- and 10-year progression-free survival rates were 91 and 86%, respectively. Patients followed up for at least 10 years (31 patients) had tumor and symptom control rates of 97 and 94%, respectively. Eight patients had repeat radiosurgery, 4 underwent delayed resection, and 4 had fractionated radiation therapy. Cerebrospinal fluid diversion was performed in 7 patients (4%). Significant risk factors for tumor progression were a tumor volume > or = 8 cm3 (p = 0.001) and male sex (p = 0.02).

CONCLUSIONS

In this 21-year experience, GKS for petroclival meningiomas obviated initial or further resection in 98% of patients and was associated with a low risk of adverse radiation effects. The authors believe that radiosurgery should be considered as an initial option for patients with smaller-volume, symptomatic petroclival meningiomas.

Intramedullary lumbar lesion mimicking spinal cord tumor: a case of non-neoplastic intramedullary spinal cord lesion

Non-neoplastic intramedullary spinal lesion cases are rarely seen in the literature. We would like to present this case for differential diagnosis of intramedullary spinal tumors. The aim of this case report is to attract attention on the MRI findings with lack of contrast enhancement and long syrinx formation which differs these types of lesions from the intramedullary spinal tumors. Intraoperative, pathological and immunohistochemical findings of non-neoplastic intramedullary spinal lesion were discussed.

A rare reason of foot drop caused by primary diffuse large b-cell lymphoma of the sciatic nerve: case report

INTRODUCTION

Primary central nervous system lymphomas account for 2% of all malignant lymphomas. Although the involvement of peripheral nerves has been previously described as a dissemination of systemic lymphomas or a direct extension to the nerve trunk from contiguous lymphomas, primary involvement of the sciatic nerve is extremely rare.

CASE

To the best of our knowledge, the primary localization of lymphoma within sciatic nerve has been reported only nine times. We report, a very rare example of a primary diffuse large B-cell lymphoma of the sciatic nerve.

DISCUSSION

The patient presented with atypical sciatica. Such symptoms can be misdiagnosed as lumbar disc pathology and magnetic resonance imaging and electrophysiological studies avoid this misinterpretation.

Prospective staged volume radiosurgery for large arteriovenous malformations: indications and outcomes in otherwise untreatable patients

OBJECTIVE

The obliteration response of an arteriovenous malformation (AVM) to radiosurgery is strongly dependent on dose and volume. For larger volumes, the dose must be reduced for safety, but this compromises obliteration. In 1992, we prospectively began to stage anatomic components in order to deliver higher single doses to symptomatic AVMs > 15 ml in volume.

METHODS

During a 17-year interval at the University of Pittsburgh, 1040 patients underwent radiosurgery for a brain AVM. Out of 135 patients who had multiple procedures, 37 patients underwent prospectively staged volume radiosurgery for symptomatic otherwise unmanageable larger malformations. Twenty-eight patients who were managed before 2002 were included in this study to achieve sufficient follow-up in assessing the outcomes. The median age was 37 years (range, 13-57 yr). Thirteen patients had previous hemorrhages and 13 patients had attempted embolization. Separate anatomic volumes were irradiated at 3 to 8 months (median, 5 mo) intervals. The median initial AVM volume was 24.9 ml (range, 10.2-57.7 ml). Twenty-six patients had two stages and two had three-stage radiosurgery. Seven patients had repeat radiosurgery after a median interval of 63 months. The median target volume was 12.3 ml. (range, 4.2-20.8 ml.) at Stage I and 11.5 ml. (range, 2.8-22 ml.) at Stage II. The median margin dose was 16 Gy at both stages. Median follow-up after the last stage of radiosurgery was 50 months (range, 3-159 mo).

RESULTS

Four patients (14%) sustained a hemorrhage after radiosurgery; two died and two patients recovered with mild permanent neurological deficits. Worsened neurological deficits developed in one patient. Seizure control was improved in three patients, was stable in eight patients and worsened in two. Magnetic resonance imaging showed T2 prolongation in four patients (14%). Out of 28 patients, 21 had follow-up more than 36 months. Out of 21 patients, seven underwent repeat radiosurgery and none of them had enough follow- up. Of 14 patients followed for more than 36 months, seven (50%) had total, four (29%) near total, and three (21%) had moderate AVM obliteration.

CONCLUSIONS

Prospective staged volume radiosurgery provided imaging defined volumetric reduction or closure in a series of large AVMs unsuitable for any other therapy. After 5 years, this early experience suggests that AVM related symptoms can be stabilized and anticipated bleed rates can be reduced.

A rare combination of a developmental venous anomaly with a varix. Case report

The most common vascular anomaly associated with a developmental venous anomaly (DVA) is a cavernous malformation. A cerebral DVA is a rare vascular malformation of the brain when it is associated with a varix. The authors report on a 13-year-old girl who presented with 2 brief episodes of nonresponsiveness that mimicked absence seizures. The computed tomography scans, magnetic resonance images, and cerebral angiograms showed a left temporal DVA in combination with a sylvian fissure varix. To maintain normal parenchymal venous drainage, no surgical intervention was performed. Radiological and clinical follow-up was planned. This case report expands the present knowledge of the rare association of a cerebral DVA with a varix and emphasizes the need for meticulous neuroimaging to avoid unnecessary surgery.

Extradural giant multiloculated arachnoid cyst causing spinal cord compression in a child

BACKGROUND

Spinal extradural arachnoid cysts are rare expanding lesions in the spinal canal. Enlargement may cause progressive signs and symptoms caused by spinal cord compression. They are associated with trauma, surgery, arachnoiditis, and neural tube defects. Most nontraumatic spinal extradural arachnoid cysts are thought to be congenital.

DESIGN

Case report and literature review.

FINDINGS

A 9-year-old boy with mild paraparesis was found to have an extradural multiloculated arachnoid cyst with fibrous septa at T4-L3 levels and anterior compression and displacement of the spinal cord.

CONCLUSIONS

Definitive treatment of arachnoid cyst entails radical cyst removal and dura cleft repair. Formation of a postoperative cerebrospinal fluid fistula may require external lumbar drainage.

Is dysphonia permanent or temporary after anterior cervical approach?

The rate, causes and prognosis of dysphonia after anterior cervical approach (ACA) were investigated in our clinical series. During a 10-year interval, 235 consecutive patients with cervical disc disease underwent surgical treatment using anterior approach. Retrospective chart reviews showed recurrent laryngeal nerve (RLN) injury in 3 (1.27%) patients. All three patients were men and only one patient had multilevel surgery. These patients had RLN injury after virgin surgery. Laryngoscopic examination demonstrated unilateral vocal cord paralysis in all patients who had postoperative dysphonia. No permanent dysphonia was observed in our series and patients recovered after a mean of 2 months (range 1-3 months) duration. Dysphonia after ACA was a rare complication in our clinical series. Pressure on RLN or retraction may result in temporary dysphonia.

Radiosurgery for miscellaneous skull base tumors

Stereotactic radiosurgery has become an integral part of conventional and advanced skull base surgery. Despite the advances in skull base techniques, the goal of total resection of such tumors is often problematic and associated with significant risk to critical structures of the skull base, including those within the cavernous sinus, those in the petrous apex, and the jugular bulb. Aggressive resection of such tumors sometimes results in severe adverse neurological events, ranging from permanent extraocular movement deficits to hearing loss, facial weakness, and difficulties with vagal and glossopharyngeal function. Gamma Knife radiosurgery is a primary alternative option for these patients. It minimizes the risks of open surgical techniques and preserves existing cranial nerve function in most patients and achieves tumor growth arrest. Adjuvant radiosurgery is used for larger tumors after their initial partial resection. Gamma Knife radiosurgery becomes an adjuvant tool to provide longterm tumor growth control of a significantly reduced tumor volume.

Intraventricular traumatic tension pneumocephalus: a case report

Traumatic tension pneumocephalus with intraventricular extension is an extremely rare, potentially lethal condition that requires prompt diagnosis and treatment. A 27-year-old man was admitted with blunt head injury and rhinorrhea. There was no pathological finding on plain X-ray and axial computed tomography (CT) images. He had nothing remarkable but persistent nasal discharge. Biochemical and histological examination showed that the rhinorrhea material was cerebrospinal fluid (CSF). Lumbar spinal drainage was performed for the treatment of rhinorrhea. On the third day of drainage, he had headache, nausea and vomiting. A skull X-ray and CT scan revealed a large volume of intraventricular and subdural air in the frontotemporoparietal region, suggesting tension pneumocephalus. The CSF drainage was removed and medical treatment with mannitol (1 g/kg) was initiated, after which CSF rhinorrhea ceased and a gradual decrease in intracranial air volume was observed on follow-up CT scans. Improvement in his condition continued and the final CT scan demonstrated resolution of the pneumocephalus. The patient was discharged without any deficit.

Prospective staged volume radiosurgery for large arteriovenous malformations: indications and outcomes in otherwise untreatable patients

OBJECTIVE

The obliteration response of an arteriovenous malformation (AVM) to radiosurgery is strongly dependent on dose and volume. For larger volumes, the dose must be reduced for safety, but this compromises obliteration. In 1992, we prospectively began to stage anatomic components in order to deliver higher single doses to symptomatic AVMs >15 ml in volume.

METHODS

During a 17-year interval at the University of Pittsburgh, 1040 patients underwent radiosurgery for a brain AVM. Out of 135 patients who had multiple procedures, 37 patients underwent prospectively staged volume radiosurgery for symptomatic otherwise unmanageable larger malformations. Twenty-eight patients who were managed before 2002 were included in this study to achieve sufficient follow-up in assessing the outcomes. The median age was 37 years (range, 13-57 yr). Thirteen patients had previous hemorrhages and 13 patients had attempted embolization. Separate anatomic volumes were irradiated at 3 to 8 months (median, 5 mo) intervals. The median initial AVM volume was 24.9 ml (range, 10.2-57.7 ml). Twenty-six patients had two stages and two had three-stage radiosurgery. Seven patients had repeat radiosurgery after a median interval of 63 months. The median target volume was 12.3 ml. (range, 4.2-20.8 ml.) at Stage I and 11.5 ml. (range, 2.8-22 ml.) at Stage II. The median margin dose was 16 Gy at both stages. Median follow-up after the last stage of radiosurgery was 50 months (range, 3-159 mo).

RESULTS

Four patients (14%) sustained a hemorrhage after radiosurgery; two died and two patients recovered with mild permanent neurological deficits. Worsened neurological deficits developed in one patient. Seizure control was improved in three patients, was stable in eight patients and worsened in two. Magnetic resonance imaging showed T2 prolongation in four patients (14%). Out of 28 patients, 21 had follow-up more than 36 months. Out of 21 patients, seven underwent repeat radiosurgery and none of them had enough follow- up. Of 14 patients followed for more than 36 months, seven (50%) had total, four (29%) near total, and three (21%) had moderate AVM obliteration.

CONCLUSIONS

Prospective staged volume radiosurgery provided imaging defined volumetric reduction or closure in a series of large AVMs unsuitable for any other therapy. After 5 years, this early experience suggests that AVM related symptoms can be stabilized and anticipated bleed rates can be reduced.

Imaging of posterior fossa epidermoid tumors

OBJECTIVE

Epidermoid tumors have similar radiologic characteristics with arachnoid cysts on routine imaging techniques. Since they warrant different therapeutic interventions, it is essential to differentiate the two pathologies and to assess operative results.

PURPOSE

The purpose of this study is to define the MR characteristics of epidermoid tumors in posterior fossa particularly on fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI).

PATIENTS AND METHODS

During a 10-year period, we operated 19 cases with epidermoid tumor of posterior fossa. The localization of the epidermoids was cerebellopontine angle in 16 patients, within the fourth ventricle in 2 patients and pineal region in 1 patient. Neuroimaging included CT in all patients, conventional MR in 14 patients and FLAIR and DWI in the last 6 patients.

RESULTS

In the first 13 cases, diagnosis of epidermoid tumor was difficult on CT and conventional MR. Epidermoids appeared as heterogeneous hyperintense lesions on FLAIR and homogenous hyperintense lesions on DWI in the last 6 patients. While total resection of the tumor was achieved in 17 patients, subtotal resection was performed in 2 patients. Histopathological examinations of the specimens revealed epidermoid tumor in all cases.

CONCLUSION

Advances in neuroradiology provide us advantages for planning the treatment modalities in epidermoid tumors of the posterior fossa. The difficulties in preoperative differential diagnosis and judgment for reoperation in the postoperative course have been decreased particularly via FLAIR and DWI.

Isolated intracranial Rosai-Dorfman disease mimicking meningioma

Sinus histiocytosis with massive lymphadenopathy (SHML), also known as Rosai-Dorfman disease (RDD), is an idiopathic histiocytic proliferation affecting lymph nodes. It is typically characterized by painless cervical lymphadenopathy, fever and weight loss. Although extranodal involvement has been reported in diverse sites, intracranial presentation, particularly in the absence of nodal disease is uncommon. To the best of our knowledge, 48 patients with intracranial masses have been reported previously. A 31-year-old man was admitted to our clinic with a 4-month history of progressive headache. His medical history was unremarkable except for occasional fever. There were not any neurological deficit and weight loss. No lymphadenopathy (particularly bilateral cervical) and extranodal involvement in diverse sites were revealed by physical and radiological examinations. Routine hematological and biochemical studies were normal except for mild leukocytosis and elevated erythrocyte sedimentation rate. The patient underwent magnetic resonance imaging (MRI) testing that revealed an enhancing mass in the left temporal lobe. Preoperative diagnosis was meningioma. The patient underwent a left frontotemporal craniotomy with complete resection of the mass. Histopathology was compatible with RDD. Extranodal RDD is rarely found intracranially. Prognosis is benign especially in the absence of nodal disease. It is clinically and radiologically difficult to distinguish from meningioma, and histological examination is essential for a definitive diagnosis.

Association of paranasal sinus osteoma and intracranial mucocele--two case reports

Two young adult males presented with paranasal sinus osteoma associated with mucocele. A 20-year-old man presented with headache and seizure, and another 20-year-old man presented with headache, frontal deformity, and visual disturbances. Both patients underwent surgery and satisfactory results were obtained. Isolated paranasal sinus osteomas are benign and slow-growing tumors, but may become more aggressive in association with mucoceles. The higher aggressiveness of the lesions may be due to the presence of the mucocele. Calcification and ossification of the mucocele probably contributes to the unexpected enlargement of the osteoma.

Treatment of L5-S1 Spondyloptosis With Single-Stage Surgery Through the Posterior Approach-Case Report-

A 21-year-old male patient with L5-S1 spondyloptosis was treated by total L-5 laminectomy with foraminotomy and posterior fusion through the posterior approach. His complaints of severe low back pain and limited spine mobility were resolved. No new deficits occurred. The surgical management of spondyloptosis includes one-, two-, or three-stage operations with posterior, anterior, or combined approaches. Careful posterior decompression and posterior fusion without reduction may be adequate for the treatment of L5-S1 spondyloptosis.

Retrospective analysis of spinal missile injuries

One hundred six patients with spinal missile injury from war zones were admitted to our department from 1994 to 2000. Functional recovery and complications in surgical and conservative treatment groups were evaluated. Sixty-five were treated surgically, of whom 55 (84%) had incomplete injuries (Frankel scores B, C, and D). In the conservative group, 28 (68%) had incomplete injuries. A total of 81 patients (53 in the surgical group, 28 in the conservative group) could be monitored for functional recovery. In the surgical group, 34 (64%) showed improvement, 15 (28%) were unchanged, and four (7%) worsened. In the conservative group, 17 (60%) improved, nine (32%) remained unchanged, and two (7%) worsened. Cerebrospinal fluid fistula was observed in ten patients, seven of them in the surgically treated group. Five of seven meningitides were seen in the surgically treated group. Surgical intervention is not essential for spinal gunshot injury; however, it may be beneficial for patients with CSF fistula, infectious and compressing foreign bodies in the injury site, instability, and rapid neurological deterioration.

Low back pain due to spinal chronic subdural hematoma mimicking intradural tumor in the lumbar area: a case report and literature review

Although magnetic resonance imaging has dramatically enhanced the ability to diagnose spinal mass lesions, some lesions remain difficult to diagnose. We report a spinal chronic subdural hematoma that comprised the cauda equina ventrally in the lumbar area in a 51-year-old man who was under anticoagulant therapy. Low back pain was the only symptom of the patient after sports activity. Surgical treatment was performed 2 months after the onset of symptoms. Intraoperative view showed chronic subdural hematoma with abnormal enlarged dural vascularization. The patient had no preoperative and postoperative neurologic deficit. Low back pain with sudden onset after minor trauma refractory to medical treatment must be investigated with magnetic resonance imaging in patients under anticoagulant therapy for spinal hematoma because of the possibility of spinal chronic subdural hematoma.

The effect of cranioplasty on cerebral hemodynamics: evaluation with transcranial Doppler sonography

BACKGROUND

The purpose of cranioplasty is not only cosmetic repair but also neurological improvement. The effect of cranioplasty on the cerebral hemodynamics flow has not been investigated by ultrasonographic techniques.

AIMS

To investigate changes of cerebral hemodynamics after cranioplasty in patients with cranial defect using transcranial Doppler sonography (TCDS).

SETTING

The Departments of Neurosurgery and Radiology of a university hospital.

DESIGN

A prospective clinical study.

MATERIAL AND METHODS

We prospectively examined the cerebral hemodynamics with TCDS pre- and postoperatively in 18 patients with cranial defect who underwent cranioplasty. All postoperative studies were done between the 7th and 15th day after cranioplasty. The anterior cerebral artery was examined through the transtemporal and transorbital windows, the middle cerebral artery through the transtemporal window, and the posterior cerebral artery through the transforaminal window. Bilaterally, the peak systolic, end diastolic and mean blood flow velocities of these arteries were measured.

STATISTICAL ANALYSIS

Wilcoxon matched-pairs signed-ranks test.

RESULTS

Before cranioplasty all the velocities ipsilateral to the cranial defect were significantly low, while in the contralateral side they were near normal. Ipsilateral low cerebral blood flows increased and reached normal levels (P<0.05) after cranioplasty. During the follow-up, neurological improvement was observed.

CONCLUSION

Cranioplasty is carried out not only for preserving normal appearances and physical barrier but also for neurological improvement. This should be explained by the normalization of cerebral hemodynamics.