Expression profiling of single cells and patient cohorts identifies multiple immunosuppressive pathways and an altered NK cell phenotype in glioblastoma.

Glioblastoma (GBM) is an aggressive cancer with a very poor prognosis. Generally viewed as weakly immunogenic, GBM responds poorly to current immunotherapies. To understand this problem more clearly we used a combination of natural killer (NK) cell functional assays together with gene and protein expression profiling to define the NK cell response to GBM and explore immunosuppression in the GBM microenvironment. In addition, we used transcriptome data from patient cohorts to classify GBM according to immunological profiles. We show that glioma stem-like cells, a source of post-treatment tumour recurrence, express multiple immunomodulatory cell surface molecules and are targeted in preference to normal neural progenitor cells by natural killer (NK) cells ex vivo. In contrast, GBM-infiltrating NK cells express reduced levels of activation receptors within the tumour microenvironment, with hallmarks of transforming growth factor (TGF)-ß-mediated inhibition. This NK cell inhibition is accompanied by expression of multiple immune checkpoint molecules on T cells. Single-cell transcriptomics demonstrated that both tumour and haematopoietic-derived cells in GBM express multiple, diverse mediators of immune evasion. Despite this, immunome analysis across a patient cohort identifies a spectrum of immunological activity in GBM, with active immunity marked by co-expression of immune effector molecules and feedback inhibitory mechanisms. Our data show that GBM is recognized by the immune system but that anti-tumour immunity is restrained by multiple immunosuppressive pathways, some of which operate in the healthy brain. The presence of immune activity in a subset of patients suggests that these patients will more probably benefit from combination immunotherapies directed against multiple immunosuppressive pathways.

Integrated fundal assessment pathway for patients with suspected shunt malfunction via digital retinal images.

Introduction: Papilloedema is an important clinical sign in the assessment of neurosurgical patients presenting with suspected shunt malfunction.Methods: We describe our 18-month experience using a newly acquired nonmydriatic digital retinal camera to acquire fundal photographs for this purpose.Results: It was used to take digital photographs in 67 patients presenting with suspected shunt malfunction and 54% of these images were discussed with the on-call ophthalmology team for advice. Of these 81% had instant input provided by ophthalmology and the remainder were sent to the ophthalmology department for formal assessment. Of all shunt related regional referrals in the same time period, we found that only 13% of the referred patients were discussed with the on-call ophthalmology team. The rest had decisions made by the on-call neurosurgical team.Conclusions: We believe this new integrated pathway is clinically and cost-effective and recommend it as a useful tool in other neurosurgical units.

A bioimpedance analysis of head-and-neck cancer patients undergoing radiotherapy.

Malnutrition is a frequent manifestation in patients with head-and-neck cancer undergoing radiation therapy and a major contributor to morbidity and mortality. Thus, body composition is an important component of an overall evaluation of nutrition in cancer patients. Malnutrition is characterized by weight loss, loss of muscle mass, changes in cell membrane integrity, and alterations in fluid balance. Bioelectrical impedance analysis is a method to analyze body composition and includes parameters such as intracellular water content, extracellular water content, and cell membrane integrity in the form of a phase angle (Φ). Bioelectrical impedance analysis has consistently been shown to have prognostic value with respect to mortality and morbidity in patients undergoing chemotherapy. The goal of the present study was to evaluate the relationship between Φ, time, intracellular water content, and weight for head-and-neck cancer patients undergoing radiotherapy. The results demonstrate that Φ decreases with time and increases with intracellular water content and weight.

Resection of cavernous angioma located in eloquent areas using functional cortical and subcortical mapping under awake conditions. Outcomes in a 50-case multicentre series.

INTRODUCTION: Surgical resection of supratentorial cavernous angiomas located in eloquent areas poses a significant risk to the patient of postoperative neurological impairment and justifies intraoperative functional monitoring. METHODS: Multicentre retrospective series of adult patients with cavernous angiomas located within eloquent areas and treated with functional-based surgical resection according to functional boundaries under intraoperative functional cortico-subcortical monitoring under awake conditions. RESULTS: Fifty patients (18 males, mean 36.3±10.8 year-old) underwent surgical resection with intraoperative cortico-subcortical functional mapping using direct electrostimulation under awake conditions for a cavernous angioma located in eloquent areas with a mean postoperative follow-up of 21.0±21.2 months. At presentation, the cavernous angioma had previously resulted in severe impairment (neurological deficit in 34%, seizures in 70%, uncontrolled seizures in 34%, reduced Karnofsky Performance Status score of 70 or less in 24%, inability to work in 52%). Functional-based surgical resection allowed complete removal of the cavernous angioma in 98% and of the haemosiderin rim in 82%. Postoperative seizures and other complications were rare, and similarly so across all centres included in this series. Postoperatively, we found functional improvement in 84% of patients (reduced Karnofsky Performance Status score of 70 or less in 6%, uncontrolled seizures in 16%, and inability to work in 11%). CONCLUSION: Functional-based surgical resection aids the safe and complete resection of cavernous angiomas located in eloquent areas while minimizing the surgical risks. Functional mapping has to be considered in such challenging cases.

Technical principles of direct bipolar electrostimulation for cortical and subcortical mapping in awake craniotomy.

INTRODUCTION: Intraoperative application of electrical current to the brain is a standard technique during brain surgery for inferring the function of the underlying brain. The purpose of intraoperative functional mapping is to reliably identify cortical areas and subcortical pathways involved in eloquent functions, especially motor, sensory, language and cognitive functions. MATERIAL AND METHODS: The aim of this article is to review the rationale and the electrophysiological principles of the use of direct bipolar electrostimulation for cortical and subcortical mapping under awake conditions. RESULTS: Direct electrical stimulation is a window into the whole functional network that sustains a particular function. It is an accurate (spatial resolution of about 5mm) and a reproducible technique particularly adapted to clinical practice for brain resection in eloquent areas. If the procedure is rigorously applied, the sensitivity of direct electrical stimulation for the detection of cortical and subcortical eloquent areas is nearly 100%. The main disadvantage of this technique is its suboptimal specificity. Another limitation is the identification of eloquent areas during surgery, which, however, could have been functionally compensated postoperatively if removed surgically. CONCLUSION: Direct electrical stimulation is an easy, accurate, reliable and safe invasive technique for the intraoperative detection of both cortical and subcortical functional brain connectivity for clinical purpose. In our opinion, it is the optimal technique for minimizing the risk of neurological sequelae when resecting in eloquent brain areas.

Direct electrical bipolar electrostimulation for functional cortical and subcortical cerebral mapping in awake craniotomy. Practical considerations.

INTRODUCTION: The aim of brain glioma surgery is to maximize the quality of resection, while minimizing the risk of sequelae. Due to the frequent location of gliomas near or within eloquent areas, owing to their infiltrative feature, and because of major interindividual variability, the anatomofunctional organization and connectivity must be studied individually. Therefore, to optimize the benefit-to-risk ratio of surgery, intraoperative functional mapping is extensively used. MATERIAL AND METHODS: This article aims at describing the rationale, indications and practical aspects of intraoperative direct electrical bipolar electrostimulation for cortical and subcortical mapping under awake conditions using the asleep-awake asleep anaesthetic protocol in the setting of cerebral gliomas. We will address the operative approach, including patient positioning, functional mapping resection strategy, anaesthetic conditions, as well as tips and pitfalls. RESULTS: The intraoperative direct electrical bipolar electrostimulation enables: (i) to study the real-time individual cortical functional organization; (ii) to study the anatomofunctional subcortical connectivity along the resection; (iii) to tailor the resection according to individual corticosubcortical functional boundaries. This is an easy, accurate, reliable, well-tolerated and safe detection technique of both cortical and subcortical functionally essential structures during resection. It should be performed in the context of a standardized protocol involving members of both anaesthesiology and neurosurgery teams at neurosurgical centers specialized in surgical neuro-oncology. CONCLUSION: Intraoperative direct electrical bipolar electrostimulation for cortical and subcortical mapping under awake conditions is currently considered the "gold standard" clinical tool for brain mapping during cerebral resection in neuro-oncology.

Surgical resection of incidental diffuse gliomas involving eloquent brain areas. Rationale, functional, epileptological and oncological outcomes.

OBJECTIVE: Incidentally discovered diffuse low-grade gliomas progress in a fashion similar to their symptomatic counterparts. Their early detection allows more effective pre-emptive and individualized oncological treatment. We assessed the safety and efficacy of maximal safe resection according to functional boundaries for incidental diffuse low-grade gliomas in eloquent areas. MATERIAL AND METHODS: Two-centre retrospective series of adult patients with incidental diffuse low-grade gliomas located within/close to eloquent areas in the dominant hemisphere, treated with maximal surgical resection according to functional boundaries under intraoperative functional cortico-subcortical monitoring under awake conditions, and with a minimal follow-up of 24months. RESULTS: The series included 19 patients (8 men, 11 women) with no preoperative neurological deficit but with a radiologically enlarged glioma. No intraoperative seizure, postoperative infection, haematoma or wound-healing problem was observed. In the immediate postsurgical period, a transient neurological worsening occurred in 10 patients. The resection (mean rate 96.4%; range, 82.4-100) was supratotal in 5 cases, total in 5 cases, subtotal in 7 cases, and partial in 2 cases. Six months after surgery, all patients recovered after functional rehabilitation, with no permanent neurological deficit, Karnofsky Performance Status was 100 (except for one patient who received early postoperative radiotherapy) and no seizures were observed. The survival without progression requiring oncological treatment was significantly longer in patients with a total/supratotal resection than in patients with a partial/subtotal resection. CONCLUSIONS: These results suggest the reproducibility, safety, and effectiveness of an early maximal functionally based resection within cortico-subcortical functional boundaries for incidental diffuse low-grade gliomas in adults in centres hyperspecialized in surgical neuro-oncology.

Poster - Thur Eve - 71: Improved dose accuracy for plan checking IMRT breast plans.

Dose verification as part of plan checking is a critical component of high quality patient care. IMSure QA is a software platform used at the BC Cancer Agency that facilitates dose verification for both conformal and IMRT plans. We have recently initiated treating breast tangents using IMRT at the Fraser Valley Centre and noted increased dose discrepancies (mean difference of -3%) between Eclipse and IMSure's QA module. We identified two potential sources of error: air flash and tissue heterogeneity. We extend our generated fluences 3cm past the breast contour and into air to account for breathing, set-up uncertainties and swelling. IMSure does not account for the fluence in air or air flash. We present an air-flash-correction factor based on the ratios of TMRs and Phantom Scatter Factors which use the field sizes of fields with and without the air flash. In addition, we present a method to improve the heterogeneity correction used by IMSure to better match that used by AAA. Effectively we remove the IMSure's inherent heterogeneity correction and manually apply a AAA-based heterogeneity-correction factor. We evaluated our correction factors on a sample of 8 patients (32 fields) using ANOVA methods to determine which dose corrections most accurately reproduce Eclipse's values. We found the air-flash correction coupled with IMSure's inherent-heterogeneity correction has the best dose accuracy (mean difference improved from -3% to 0.3%). The AAA-heterogeneity correction alone also improved the accuracy (mean difference improved from -3% to - 1.5%), which is acceptable for plan checking purposes.

Poster - Thur Eve - 57: Craniospinal irradiation with jagged-junction IMRT approach without beam edge matching for field junctions.

PURPOSE: Craniospinal irradiation were traditionally treated the central nervous system using two or three adjacent field sets. A intensity-modulated radiotherapy (IMRT) plan (Jagged-Junction IMRT) which overcomes problems associated with field junctions and beam edge matching, improves planning and treatment setup efficiencies with homogenous target dose distribution was developed. METHODS AND MATERIALS: Jagged-Junction IMRT was retrospectively planned on three patients with prescription of 36 Gy in 20 fractions and compared to conventional treatment plans. Planning target volume (PTV) included the whole brain and spinal canal to the S3 vertebral level. The plan employed three field sets, each with a unique isocentre. One field set with seven fields treated the cranium. Two field sets treated the spine, each set using three fields. Fields from adjacent sets were overlapped and the optimization process smoothly integrated the dose inside the overlapped junction. RESULTS: For the Jagged-Junction IMRT plans vs conventional technique, average homogeneity index equaled 0.08±0.01 vs 0.12±0.02, and conformity number equaled 0.79±0.01 vs 0.47±0.12. The 95% isodose surface covered (99.5±0.3)% of the PTV vs (98.1±2.0)%. Both Jagged-Junction IMRT plans and the conventional plans had good sparing of the organs at risk. CONCLUSIONS: Jagged-Junction IMRT planning provided good dose homogeneity and conformity to the target while maintaining a low dose to the organs at risk. Jagged-Junction IMRT optimization smoothly distributed dose in the junction between field sets. Since there was no beam matching, this treatment technique is less likely to produce hot or cold spots at the junction in contrast to conventional techniques.

[Prostate and seminal vesicle displacement following urethrography: a computed tomography-based study]. / Déplacements de la prostate et des vésicules séminales suite à l'uréthrographie: une étude par tomographie axiale.

PURPOSE: It has been suggested that urethrography used for localization of the prostate apex may cause a systematic cranial displacement of the organ. Our objective was to use CT-CT image registration to identify if a clinically relevant systematic shift occurs in the position of the prostate and seminal vesicles following retrograde urethrography. PATIENTS AND METHODS: Patients were scanned twice at the time of simulation. They were imaged supine, bladder empty. Scan resolution was 512x512 with 5 mm cuts. After the first CT sequence, with the patient still on the CT couch, an urethrogram was performed. The patients were then re-scanned. The image sets were registered through the use of external skin fiducials. A single author reviewed x, y and z-axis displacement. Z-axis motion of the prostate was also assessed by having three blinded radiation oncologists mark the cranial limit of the prostate on all 104 image sets. RESULTS: Fifty-two pairs of CT scans were analyzed for post-urethrogram organ displacement. The mean x axis displacement of the prostate was 0.016 mm (P=0.8), the mean y-axis displacement was 1.3 mm anterior (P<0.001). Mean z-axis displacement of the prostate, using the blinded assessments, was a 1.35 mm cranial shift (P<0.0001). Analogous shifts were identified for the seminal vesicles. CONCLUSION: Our results suggest a small cranial and anterior displacement of the prostate and seminal vesicles following retrograde urethrography.

Outcome of local excision of rectal carcinoma.

PURPOSE: This study was designed to determine the results of patients with rectal adenocarcinoma treated with local excision. METHODS: A retrospective, chart review was conducted for all patients treated with local excision for rectal adenocarcinoma from 1984 to 1998. RESULTS: Sixty-four patients were retained for analysis. The median follow-up was 37 (range, 9-125) months. There were 15 local failures with a median time to local failure of 12 months. Seven patients were salvaged with further operation (4 by repeat local excision, 4 by abdominoperineal resection, and 1 by low anterior resection). The incidence of local recurrence increased with advancing stage of the carcinoma (T1, 13 percent; T2, 24 percent; T3, 71 percent), histologic grade of differentiation, (well, 12 percent; moderately, 24 percent; poorly, 44 percent), and margin status (negative, 16 percent; close (within 2 mm), 33 percent; positive, 50 percent). Sixteen percent of carcinomas < or = 3 cm failed compared with 47 percent for carcinomas > 3 cm. Nine percent (1/11) of T2 patients treated with adjuvant radiation therapy recurred locally compared with 36 percent (5/14) without radiation therapy. Three of four T3 patients who received radiation therapy failed locally compared with two of three who did not. Using the Kaplan-Meier method, the overall survival at five years was 71 percent, and disease-free survival was 83 percent. Actuarial local failure was 27 percent and freedom from distant metastasis was 86 percent. The sphincter preservation rate was 90 percent at five years. CONCLUSIONS: Local excision alone is an acceptable option for well-differentiated, T1 carcinomas, < or = 3 cm. Adjuvant radiation is recommended for T2 lesions. The high local recurrence rate in patients after local excision of T3 lesions with or without adjuvant radiotherapy would mandate a radical resection.

Boerhaave's syndrome: CT diagnosis.

Boerhaave's syndrome is the postemetic rupture of a normal oesophagus, the diagnosis of which is not always immediately apparent. We present here a case report which illustrates the value of computed tomography (CT) scanning in making this often difficult diagnosis.

Neurocalcin-alpha immunoreactivity in the enteric nervous system of young and aged rats.

The distribution of the calcium binding protein neurocalcin a has been examined in the enteric nervous system of young adult (3 months) and aged (24+ months) male rats by immunofluorescence. Neurocalcin-immunoreactive (NC-ir) neurons were observed in the submucous and myenteric plexuses throughout the gastrointestinal tract from the oesophagus to the distal large intestine. NC-ir nerve terminals were also seen on NC-ir and NC-negative neurons. Semiquantitative estimates revealed fewer NC-ir neurons in the submucous plexus than in the myenteric plexus. The greatest occurrence of NC-ir neurons was in the small and large intestine. NC-ir axons were seen in the mucosa and also in between the ganglia of the myenteric plexus. In the aged rats, there were no discernible changes in the numbers of NC-ir neurons in th e oesophagus and stomach, with an increase in the pylorus and slight decreases in the small and large intestines. No decrease in NC-ir was observed in the distal large intestine. NC-ir neurons never contained lipofuscin age pigment and many enteric neuro ns devoid of NC-ir contained age pigment. Like other previously investigated calcium-binding proteins in enteric neurons, the distribution of NC shows much variability from one part of the intestine to another. The observed slight decreases in the number of NC-ir enteric neurons in aged rats may compromise the regulation of calcium in these neurons.

Stereotactic radiosurgery in the management of angiographically occult vascular malformations.

PURPOSE: To evaluate the role of stereotactic radiosurgery in the treatment of angiographically occult vascular malformations (AOVMs). METHODS AND MATERIALS: From 1987 to 1996, 21 patients, 10 males and 11 females, median age of 41 years (range: 7-75 years), with an intracerebral AOVM underwent stereotactic radiosurgery at our institution. All were considered at high risk for surgical intervention. The vascular lesions were located in the brainstem (17 patients), basal ganglia (2), occipital lobe (1), and cerebellum (1). Diagnosis was based on high-resolution magnetic resonance imaging (MRI). Clinical presentation at onset included previous intracerebral hemorrhage (20 patients) and epilepsy (1). All patients were treated with a linac-based radiosurgical technique. The median dose delivered was 25 Gy (range 13-50 Gy), typically prescribed to the 80-90% isodose surface (range 50-90%), which corresponded to the periphery of the vascular malformation. Patients were followed by clinical neurologic assessment and by MRI on a regular interval basis. RESULTS: Follow-up was obtained in 20 patients; clinical or MRI information was not available for 1 patient, and this patient was excluded from our analysis. At a median follow-up of 77 months (range: 4-141 months), follow-up MRIs postradiosurgery do not demonstrate any changes in the appearance of the AOVM. Four patients developed an intracranial bleed at 4, 8, 35, and 57 months postradiosurgery. Annual hemorrhage rates were considerably higher in the observation period preradiosurgery than postradiosurgery (30% vs. 3.2%, p < 0.001). Complications postradiosurgery were observed in 4 patients. Three patients developed mild to moderate edema surrounding the radiosurgical target, expressed at 5, 8, and 24 months, respectively. In all cases, the edema was transient and resolved completely on subsequent MRIs. One of the 4 patients developed radiation necrosis 8 months after radiosurgery. CONCLUSION: The use of stereotactic radiosurgery in the treatment of AOVM continues to be controversial. Our results appear to show a reduction in the risk of symptomatic hemorrhage post treatment. Patients with previous history of hemorrhage or progressive neurologic deficit and small, well circumscribed lesions may benefit from a trial of stereotactic radiosurgery.

Decreased neurocalcin immunoreactivity in sympathetic and parasympathetic neurons of the major pelvic ganglion in aged rats.

In the rat the majority of sympathetic and parasympathetic postganglionic neurons that innervate the pelvic viscera are located together in the major pelvic ganglia. We have ascertained that it is only the sympathetic population of this ganglion that exhibits age-associated attrition. Recent immunohistochemical investigations of the distribution of calcium binding proteins in this ganglion in young adult and aged rats have demonstrated that calbindin-D28k is only present in the sympathetic neurons and that the number of calbindin-immunoreactive sympathetic neurons of the aged ganglion was dramatically reduced. In the present study we have investigated the distribution of neurocalcin (NC) alpha isoform in the major pelvic ganglion. In young adults 98.7% of sympathetic neurons (identified by anti-tyrosine hydroxylase immunostaining) and 98% of parasympathetic neurons (identified by anti-nitric oxide synthase immunostaining) contained NC immunoreactivity and these figures are reduced to 68 and 45.5% in the aged group. Thus, unlike calbindin-D28k, NC is not confined to the sympathetic neuron population in the major pelvic ganglion and decreases significantly in old age in both neuronal populations. The likely effects are to impair intracellular calcium-dependent signalling in neurons of the major pelvic ganglion, possibly compounding the effects of the previously reported decrease in calbindin-D28k in the sympathetic population.

High dose tamoxifen and radiotherapy in patients with glioblastoma multiforme: a phase IB study.

PURPOSE: To assess the feasibility and the toxicity of adjuvant high dose tamoxifen (TAM) and postoperative brain irradiation for patients with newly-diagnosed glioblastoma multiforme (GBM). MATERIAL AND METHODS: Twelve patients with histopathologically confirmed GBM entered the study. There were nine males and three females, with median age of 48.8 years (range 30-75 years). Karnofsky performance status (KPS) was 60-70% for four patients and 80-100% for eight patients. Based on the Radiation Therapy Oncology Group recursive partition analysis, there were three class III patients, six class IV, one class V, and two class VI. Eleven patients underwent partial surgical tumor resection and one patient had a near complete resection. Two weeks post surgery, the patients were started on high dose TAM (120 mg/m2 P.O. BID for three months). Two weeks from date of starting TAM, external beam radiotherapy (RT) was given at a dose of 59.4 Gy/33 qd fractions/6.5 weeks. Patients were assessed weekly for toxicity during treatment. Imaging studies were done at the end of two weeks of TAM, then monthly. RESULTS: Median follow-up was 40 weeks (range 22-84 weeks). In one patient, TAM was associated with significant vomiting, necessitating the TAM dose to be decreased at three weeks and then stopped at two months. One other patient had bilateral deep venous thrombosis after 52 weeks on TAM, although the relationship to TAM was not firmly established. There were no radiological responses after two weeks of TAM or at the end of RT. The median time to progression was 17.7 weeks (range 5.1-43.8 weeks). Median survival time was 33.4 weeks (range 10-79.7). Actuarial survival at 48 and 74 weeks was 40% and 15%, respectively. CONCLUSION: Our study shows that adjuvant high dose TAM is feasible and relatively well-tolerated. Furthermore, the combined use of high dose TAM and RT postoperatively was not associated with any significant increase in radiation-induced neurological toxicity. However, high dose TAM does not appear to improve treatment results.

Decreased calbindin-D28k immunoreactivity in aged rat sympathetic pelvic ganglionic neurons.

The rat major pelvic ganglion contains the majority of sympathetic and parasympathetic postganglionic neurons that innervate the pelvic viscera. Previous studies have indicated that it is only the sympathetic population of this ganglion that is susceptible to age-associated changes. We have examined the distribution of the neuronal calcium binding proteins calbindin-D28k, calretinin and parvalbumin by immunohistochemistry in young adult and aged rats and have discovered that calbindin-D28k is only present in the sympathetic neurons (identified by tyrosine hydroxylase immunostaining) and not in parasympathetic neurons (identified by VIP immunostaining). In the aged rats the number of calbindin-immunoreactive sympathetic neurons of the major pelvic ganglion was dramatically reduced. Calretinin and parvalbumin-immunoreactivity was present at a lower level of fluorescence than that of calbindin immunoreactivity in all the neurons of the major pelvic ganglion and this level was unchanged in aged rats. Thus we suggest that the decline of intracellular calbindin D28k levels may lead to impaired calcium buffering capacity which might be a contributory factor in the age-associated attrition of pelvic sympathetic neurons.

Designing attenuators for total-body irradiation using virtual simulation.

In total-body photon irradiation, the lungs are the most commonly shielded organ. Lung compensators are often designed by using high-energy portal films. Other organs, such as the kidneys and liver, are poorly visualized in portal films due to their unit-density composition. A computed tomography-based technique to design kidney and liver attenuators involves outlining these organs in a virtual simulation. The position and the shape of the attenuator are then determined from a digitally-reconstructed radiograph. Appropriate attenuator thickness is determined from measured transmission curves. This article provides a summary of this technique for total-body photon irradiation in a 4-MV photon beam.