Bevacizumab dose adjustment to improve clinical outcomes of glioblastoma

BACKGROUND

Glioblastoma (GBM) is one of the most aggressive and vascularized brain tumors in adults, with a median survival of 20.9 months. In newly diagnosed and recurrent GBM, bevacizumab demonstrated an increase in progression-free survival, but not in overall survival.

METHODS

We conducted an in silico analysis of VEGF expression, in a cohort of 1082 glioma patients. Then, to determine whether appropriate bevacizumab dose adjustment could increase the anti-angiogenic response, we used in vitro and in vivo GBM models. Additionally, we analyzed VEGFA expression in tissue, serum, and plasma in a cohort of GBM patients before and during bevacizumab treatment.

RESULTS

We identified that 20% of primary GBM did not express VEGFA suggesting that these patients would probably not respond to bevacizumab therapy as we proved in vitro and in vivo. We found that a specific dose of bevacizumab calculated based on VEGFA expression levels increases the response to treatment in cell culture and serum samples from mice bearing GBM tumors. Additionally, in a cohort of GBM patients, we observed a correlation of VEGFA levels in serum, but not in plasma, with bevacizumab treatment performance.

CONCLUSIONS

Our data suggest that bevacizumab dose adjustment could improve clinical outcomes in Glioblastoma treatment.

Treatment of neuropathic deafferentation pain using DREZ lesions; long-term results

INTRODUCTION

Deafferentation pain secondary to spinal cord injury, brachial plexus avulsion and other peripheral nerve injuries is often refractory to conventional treatments. This study evaluates the long-term efficacy of spinal DREZ (Dorsal Root Entry Zone) lesions for the treatment of neuropathic pain syndromes caused by deafferentation.

PATIENTS AND METHODS

A series of 18 patients with refractory deafferentation pain treated with radiofrequency DREZ lesions is presented. The immediate and long-term efficacy was measured with the Visual Analogue Scale (VAS) before and after treatment, the patient's subjective evaluation, the percentage of patients returning to work and the reduction in pain medication.

RESULTS

Pain on the VAS significantly decreased from 8.6 preoperatively to 2.9 (p<.001) at discharge. Over the long-term, with a mean follow-up of 28 months (6-108) pain remained at 4.7 on the VAS (p<0.002). The percentage of patients with moderate to excellent pain relief was 77% at discharge and 68% at the last follow-up. Pain medication was reduced in 67% of the patients and 28% returned to work. The best results were obtained in patients with brachial plexus avulsion, with a significant long-term pain relief in all cases.

CONCLUSIONS

Radiofrequency DREZ lesion is an effective and safe treatment for refractory neuropathic pain caused by deafferentation.

[Immunotherapy in high grade astrocytomas: principles and current state]

It is generally accepted that tumour development promotes a systemic response leading to protect the host against cancer. However, tumours may as well elicit a partial immunodeficiency to avoid the development of a complete and active immune response. Since Bloom's first studies on immunotherapy to treat high grade gliomas in 1960, many attempts have been made from different medical specialties to use the immune system as a weapon against a great diversity of cancers. Main objective of this study is to outline the basic features of the immune response inside the Central Nervous System, the strategies employed by astrocytic tumours to evade body defences, and to provide an extended literature review on research on immunotherapy, especially concerning its patho-physiology and the clinical results achieved till date.

[Akinetic mutism related to hydrocephalus and cerebellar surgery treated with bromocriptine and ephedrine. A pathophysiological review]

Akinetic mutism (AM) is a behavioral disorder characterized by impossibility to move or speak in awake patients. lt has been typically described as a transient disorder following posterior fossa tumour resection. Besides, AM may also appear after recurrent shunt failures in hydrocephalic patients, with no tendency towards improvement, either spontaneously or with shunt revisions. However successful treatment of this second type of AM has been achieved with bromocriptine. We present a patient who developed AM after a posterior fossa surgery complicated by ventriculitis and multiple hydrocephalic events. AM only improved with bromocriptine. We review AM pathophysiology. Although not well known, it appears to be quite different, depending on its cerebellar or hydrocephalic origin. Damage to dentate nucleus or its efferents (mainly of glutamate) should promote AM of cerebellar origin, while damage to paraventricular monoaminergic pathways could explain AM related to repeated shunt failures which has successful response to bromocriptine treatment. However, a more complete study of this disorder is required to ascertain its aetiology.

Surgical activity by Spanish Residents in Neurosurgery under the Training Programme in place since 1984 and changes to be implemented under the New Training Programme

The Spanish National Committee for Neurosurgery has recently approved a new training programme which will shortly replace the former programme, which dates from 1984. The object of this report was to evaluate training in neurosurgery in Spain under the extant programme as perceived by the residents themselves. Assessment of any educational shortcomings might help in designing and evaluating the new one. Secondary objects were to present and discuss the principal changes to be implemented by the new programme.A questionnaire was circulated to the entire population of Spanish neurosurgical residents nation-wide (N = 62) in 2000, and this was repeated using the same group in 2001 and 2002. Residents were to answer questions concerning their experience during the reporting year and the preceding years, the results compiling information for 1996 to 2002. The questionnaire covered 72 surgical procedures listed in ascending order of complexity, with a five-point scale of surgical responsibility for each type. Responses were received from 48 residents. Spanish residents appeared to uniformly fulfil the general requirements of the former programme. The main shortcomings identified were low levels of surgical activity for certain special operations, especially functional and skull base approaches, and the absence of a log book specific to neurosurgery. The new training programme developed by the Spanish National Committee for Neurosurgery has taken these shortcomings into consideration and has introduced major changes in order to ensure that training will be improved on an ongoing basis.

[Management of recurrent trigeminal neuralgia after failed microvascular decompression]

OBJECTIVE

To evaluate the surgical management of patients with trigeminal neuralgia after failed microvascular decompression.

PATIENTS AND METHODS

Between 1993 and 2002, exploration of the posterior fossa was performed in 60 patients with trigeminal neuralgia. Records were analyzed retrospectively for those patients who needed another surgical procedure due to recurrence of pain, describing which procedure was performed, postoperative results and complications, and also the intraoperative findings when posterior fossa reexploration was realized.

RESULTS

Eighteen patients had trigeminal neuralgia recurrence requiring a new surgical intervention, that consisted in a fossa posterior reexploration in nine patients and percutaneous radiofrequency termal rhizotomy in the other nine patients. Among the repeat operations, there was negative exploration in 7 patients (77%), and a partial sensory rhizotomy was performed. Most of thermocoagulations (5/9) were performed in old patients or patients with anestesic contraindication for the fossa posterior reexploration.

CONCLUSION

Fossa posterior reexploration is an effective and safe surgical attitude in the treatment of recurrent trigeminal neuralgia after failed microvascular decompression. Partial sensory rhizotomy is recommended when the reexploration is negative.

[Decompressive craniectomy in malignant infarction of the middle cerebral artery]

INTRODUCTION

Medically managed malignant infarction of the middle cerebral artery (MCA) is associated with an 80% mortality rate. However, several studies report a 40-50% increase in survival rates when decompressive craniectomy is performed. We present our experience with such surgical treatment and a literature review.

PATIENTS AND METHODS

Seven decompressive craniectomies were performed on five patients for spaceoccupying MCA infarctions. Age ranged from 33 to 57 years-old (three males and two females). Preoperative GCS score was 9-13. Cranial CT was performed within the first 12 hours. Intracranial pressure (ICP) was continuously measured in four patients. Two infarcts occurred in the dominant hemisphere and three in the non-dominant side. Wide fronto-parieto-temporal craniectomies were performed. The duramater was opened and a large heterologous dura graft was placed.

RESULTS

Surgery was performed on the second day after the onset of symptoms (median: 47 hours). Preoperative ICP ranged from 27 to 50 mmHg (median: 30.5 mmHg), with immediate postoperative ICP under 15 mmHg in all patients. Two patients (both non-dominant side) survived with good (after reoperation) and excellent functional outcome. They remain stable after ten and five months of follow-up. Three patients died five, five and thirteen days after admission due to uncontrollable high ICP. In our experience, bone removal itself was more relevant than dural opening for ICP control. Initial wide craniectomies may spare reoperations.

CONCLUSION

The significant mortality rate reduction, a wide therapeutic window (2-3 days) and a low incidence of intraoperative complications make decompressive craniectomy a relevant treatment in malignant cerebral MCA infarction.

[Ruptured aneurysms presenting with subdural hematoma: management without angiography]

INTRODUCTION

Ruptured aneurysms on rare occasions cause subdural hematomas as described in literature. Sudden deterioration and coma is a common feature in those patients and a emergent surgical attitude is prompt required, even without confirmation with angiography.

CASE REPORTS

We described three cases with acute subdural hematomas and little or no subarachnoid hemorrhage caused by ruptured aneurisms who presented with rapid neurologic deterioration. Urgent craniotomy and evacuation of the hematoma was performed without previous angiography in the three patients. In two patients the aneurysm was found during surgical exploration and subsequently clipped; in the remaining patient the aneurysm was embolized postoperatively.

CONCLUSIONS

The occurrence of a subdural hematoma caused by the rupture of an intracranial aneurysm must be suspected in spontaneous subdural hematomas, especially in association with disproportioned conscious deterioration. All the three patients we report debuted with sudden conscious deterioration. If a ruptured aneurysm causing subdural hematoma is suspected, early surgical intervention is required even if angiography is not available. Severe neurological deficit and uncal herniation might still be reversible if provided decompression can be carried out in promptly. Angiography availability should not postpone surgery. Aneurysm presence should be ruled out whether by surgical exploration or by delayed angiography. Posterior communicating aneurysm are related to formation of subdural hematoma.