Third harmonic generation imaging for fast, label-free pathology of human brain tumors

In brain tumor surgery, recognition of tumor boundaries is key. However, intraoperative assessment of tumor boundaries by the neurosurgeon is difficult. Therefore, there is an urgent need for tools that provide the neurosurgeon with pathological information during the operation. We show that third harmonic generation (THG) microscopy provides label-free, real-time images of histopathological quality; increased cellularity, nuclear pleomorphism, and rarefaction of neuropil in fresh, unstained human brain tissue could be clearly recognized. We further demonstrate THG images taken with a GRIN objective, as a step toward in situ THG microendoscopy of tumor boundaries. THG imaging is thus a promising tool for optical biopsies.

Implementation of a multi-institutional diffuse intrinsic pontine glioma autopsy protocol and characterization of a primary cell culture

AIMS

Diffuse intrinsic pontine glioma (DIPG) is a fatal paediatric malignancy. Tumour resection is not possible without serious morbidity and biopsies are rarely performed. The resulting lack of primary DIPG material has made preclinical research practically impossible and has hindered the development of new therapies for this disease. The aim of the current study was to address the lack of primary DIPG material and preclinical models by developing a multi-institutional autopsy protocol.

METHODS

An autopsy protocol was implemented in the Netherlands to obtain tumour material within a brief post mortem interval. A team of neuropathologists and researchers was available at any time to perform the autopsy and process the material harvested. Whole brain autopsy was performed and primary DIPG material and healthy tissue were collected from all affected brain areas. Finally, the study included systematic evaluation by parents.

RESULTS

Five autopsies were performed. The mean time interval between death and time of autopsy was 3 h (range 2-4). All tumours were graded as glioblastoma. None of the parents regretted their choice to participate, and they all derived comfort in donating tissue of their child in the hope to help future DIPG patients. In addition, we developed and characterized one of the first DIPG cell cultures from post mortem material.

CONCLUSION

Here we show that obtaining post mortem DIPG tumour tissue for research purposes is feasible with short delay, and that the autopsy procedure is satisfying for participating parents and can be suitable for the development of preclinical DIPG models.

Impact of extent of resection of glioblastoma multiforme (GBM) in the era of chemoradiation

e13029

Background: Controversy remains regarding the impact of the extent of resection (EOR) on survival in patients with GBM (Sanai 2008). The main reason for this is the fact that most studies were based on the surgeon's estimate of the EOR, which is known to be unreliable, rather than early postoperative MRI scans (po-MRI). Data for the current standard of postoperative chemo-radiotherapy (CTRT) have recently been reported, but suffer from the same limitation (Gorlia 2008). We studied the prognostic impact of the EOR using early (<72 hours) po-MRI scans in a cohort of GBM patients treated with CTRT in a single center. Methods: The results of 48 consecutive patients (35 male, 13 female; age 18–73 yrs) treated with surgery, followed by concurrent CTRT (60 Gy plus temozolomide) and adjuvant temozolomide were assessed with respect to survival and relapse patterns. EOR was determined by both the surgeon's estimation and early po-MRI scans that were available in all but two patients. EOR was categorized as biopsy (N = 3), partial resection (N = 24), major resection (N = 11; i.e., total resection according to the surgeon's report, but residual tumor on po-MRI), and total resection (N = 10; i.e. no residual tumor on po-MRI). Results: Median overall survival of the entire cohort was 18.9 months, and EOR was the only significant prognostic factor (p = 0.02) on multivariate analysis, which also included age, gender, performance, and radiotherapy target volume. 2-year survival rates improved significantly with increasing EOR, with 0%, 18.9%, 68.6%, and 100% for biopsy, partial-, major-, and total resection, respectively. In-field progression was the predominant pattern of failure in 27 out of 30 patients (90%) with a recurrence. Time to neurological progression (TNP) was significantly correlated with EOR (p < 0.001). Median TNP was 3.0 months for biopsy, 7.0 months for partial resection, 20.5 months for major resection, and was not reached for total resection. Conclusions: With the use of more effective local therapy in the form of surgery and CTRT, the prognostic impact of the EOR on survival appears to be higher than previously reported. This should be accounted for in future trials.

No significant financial relationships to disclose.

Mature astrocytes in the adult human neocortex express the early neuronal marker doublecortin

Doublecortin (DCX) is a microtubule-associated protein expressed by migrating neuroblasts and is considered to be a reliable marker of neurogenesis. DCX has been used to study the relation between neurogenesis in adult human brain and neurological and neurodegenerative disease processes in the search for putative therapeutic strategies. Using autopsy and surgically resected tissue from a total of 60 patients, we present evidence that DCX is present in several cellular compartments of differentiated astrocytes in the adult human neocortex. One of these compartments consisted of peripheral processes forming punctate envelopes around mature neuronal cell bodies. Markers of glial activation, such as GFAP and HLA, were not associated with DCX immunoreactivity, however, the presence of cytoarchitectural alterations tended to correlate with reduced DCX staining of astrocytic somata. Interestingly, local Alzheimer pathology that showed no relation with cytoarchitectural abnormalities appeared to correlate negatively with the expression of DCX in the astrocytic somata. In combination with the literature our data support the view that DCX in the adult human neocortex may have a function in glia-to-neuron communication. Furthermore, our results indicate that in the adult human neocortex DCX is neither a reliable nor a selective marker of neurogenesis.

Basilar impression in osteogenesis imperfecta: can it be treated with halo traction and posterior fusion?

Basilar impression (BI) and hydrocephalus complicating osteogenesis imperfecta (OI) is usually treated by anterior transoral decompression and posterior fixation. Nevertheless, it may be questioned if posterior fusion following axial halo traction is adequate in patients with symptomatic BI complicating OI. We report on a case with progressive symptomatic hydrocephalus and BI complicating OI that was successfully treated by halo traction followed by posterior occipitocervical fusion. However, after a symptom free interval of 2 years the patient suffered from recurrence of symptomatic hydrocephalus needing additional ventriculoperitoneal (VP) shunt placement. In conclusion, posterior fusion without additional VP shunt placement may not be effective in the long term for ameliorating symptoms and signs and halting progressive hydrocephalus in BI complicating OI.

Transpedicular wedge resection osteotomy for the treatment of a kyphotic Andersson lesion-complicating ankylosing spondylitis

Two cases with a long-standing thoracolumbar kyphosis due to ankylosing spondylitis are presented with a symptomatic localized destructive kyphotic lesion of the spine. Clinical and radiographic findings demonstrated a progressive vertebral and discovertebral kyphotic pseudarthrosis, known as an Andersson lesion, at the L1 and L1-2 level, respectively. Surgical correction and stabilization was performed by an extending transpedicular wedge resection osteotomy to restore spinal stability, to facilitate fracture healing as well as to restore the sagittal balance of the ankylosed spine. To predict the effect of a surgical correction of the Andersson lesion on the sagittal balance, deformity planning was performed preoperatively. The indication for surgery, the surgical technique and the 2 years' clinical results are described. In addition, the difficulties experienced with preoperative deformity planning are evaluated.

Cerebral microdialysis and positron emission tomography after surgery for aneurysmal subarachnoid hemorrhage in grade I patients

BACKGROUND

Using cerebral microdialysis, baseline values for energy-related chemical markers have been reported in awake patients. Radionuclide studies have demonstrated a locally decreased metabolism, thought to be the result of brain retraction. These baseline values, however, may not be applicable to patients after surgical aneurysm repair following a subarachnoid hemorrhage (SAH). We assessed metabolic chemical marker levels in World Federation of Neurological Surgeons Committee (WFNS) grade I SAH patients after aneurysm surgery and compared them with previously reported baseline values.

METHODS

In 5 WFNS grade I SAH patients, energy-related chemical marker levels were obtained using microdialysis in the area of brain retraction after aneurysm surgery. In addition, an [(18)F]2-deoxy-d-glucose positron emission tomography (FDG-PET) was performed.

RESULTS

The FDG-PET showed a decrease of glucose metabolism in the frontotemporal area. Comparing the mean values for chemical markers of this study with reported baseline values, the most striking difference was a mild decrease of pyruvate and an increase of the lactate/pyruvate ratio. In individual patients, some markers indicated possible ischemia. A consistent pattern or ischemic profile for all markers, however, was not found.

CONCLUSION

FDG-PET scanning confirmed postoperative metabolic changes found in previous studies. Mean interstitial chemical marker levels ranged from normal to mildly deviant compared with reference chemical marker levels for awake patients and are likely to be applicable in SAH patients after aneurysm repair.

[Nocturnal back pain; a misdiagnosed symptom of spinal tumor]

Four patients had nocturnal back pain or pain that worsened when lying down. In one of these, a 49-year-old man, the medical history mentioned a malignancy, as a result of which a spinal metastasis was suspected. In the other three patients, a 52-year old woman and two men aged 48 and 60 years, the nocturnal back pain and the back pain worsening when lying down was not recognised as indication of a spinal tumour. As objective neurological symptoms were not established at initial investigation, a long period of discomfort and frustration followed before the spinal tumour was diagnosed eventually. The importance of recognising these early complaints is stressed. Nowadays, MRI is the technique of choice to answer the question whether there is a space occupying process in the spine.

Local neurotoxicity of hematoporphyrin derivative following intracerebral injection

The present study reports on toxicity of hematoporphyrin derivative (HpD) for normal brain tissue in vivo without the addition of light. Hematoporphyrin derivative was injected by slow infusion in rat brains. Histological examination was carried out for intervals after HpD administration, ranging from 0 h to 15 days. Ultrastructural changes were examined with transmission electron microscopy. The extent of the necrosis was determined for different HpD concentrations and compared with control animals infused with 0.9% saline. Leukocytic infiltration was observed at day 5. Transmission electron microscopy showed that nuclei of neurons were completely disintegrated 4 h after HpD administration. Furthermore disruption of myelin sheaths was observed. The extent of the necrosis decreased with lower HpD doses. Injection of 2 micrograms HpD in a volume of 4 microL (0.5 mg/mL) resulted in a virtually equal extension of the tissue damage, as compared to the mechanical damage in the control animals caused by the infusion procedure.

Photodynamic therapy of malignant glioma. A review of literature

Photodynamic therapy is a new form of cancer treatment which can serve as an adjuvant therapy for malignant glioma. It is based on the selective retention of a photosensitive dye in tumour tissue. Subsequent exposure of the tumour to light of an appropriate wavelength causes selective destruction of tumour tissue. Experimental data indicates that the blood-brain barrier plays an important role in the delivery of the photosensitizer to a brain tumour and that intratumoral injection of the photosensitizer may be advantageous as compared to intravenous administration. A limited group of patients have entered clinical trials. Treatment protocols varied too much and the number of patients was too small to draw any conclusions on the efficiency of PDT of gliomas.