Sensitivity of fetal RHD screening for safe guidance of targeted anti-D immunoglobulin prophylaxis: prospective cohort study of a nationwide programme in the Netherlands

OBJECTIVE

 To determine the accuracy of non-invasive fetal testing for the RHD gene in week 27 of pregnancy as part of an antenatal screening programme to restrict anti-D immunoglobulin use to women carrying a child positive for RHD DESIGN:  Prospectively monitoring of fetal RHD testing accuracy compared with serological cord blood typing on introduction of the test. Fetal RHD testing was performed with a duplex real time quantitative polymerase chain reaction, with cell-free fetal DNA isolated from 1 mL of maternal plasma The study period was between 4 July 2011 and 7 October 2012. The proportion of women participating in screening was determined.

SETTING

 Nationwide screening programme, the Netherlands. Tests are performed in a centralised setting.

PARTICIPANTS

 25 789 RhD negative pregnant women.

MAIN OUTCOME MEASURES

 Sensitivity, specificity, false negative rate, and false positive rate of fetal RHD testing compared with serological cord blood typing; proportion of technical failures; and compliance to the screening programme.

RESULTS

 A fetal RHD test result and serological cord blood result were available for 25 789 pregnancies. Sensitivity for detection of fetal RHD was 99.94% (95% confidence interval 99.89% to 99.97%) and specificity was 97.74% (97.43% to 98.02%). Nine false negative results for fetal RHD testing were registered (0.03%, 95% confidence interval 0.01% to 0.06%). In two cases these were due to technical failures. False positive fetal RHD testing results were registered for 225 samples (0.87%, 0.76% to 0.99%). Weak RhD expression was shown in 22 of these cases, justifying anti-D immunoglobulin use. The negative and positive predictive values were 99.91% (95% confidence interval 99.82% to 99.95%) and 98.60% (98.40% to 98.77%), respectively. More than 98% of the women participated in the screening programme.

CONCLUSIONS

 Fetal RHD testing in week 27 of pregnancy as part of a national antenatal screening programme is highly reliable and can be used to target both antenatal and postnatal anti-D immunoglobulin use.

Antigen delivery systems

Many vaccine candidates are highly purified, sometimes monomeric antigens and as a result, not very immunogenic. Antigen delivery systems optimize the presentation of antigens. They also play a major role in solving the problem of there being an increasing number of vaccines but limited opportunities in which to include these vaccines in immunization programs. The number of injections is restricted and combining vaccines may lead to immunological and physicochemical incompatibility. In this review, the current status with respect to parenteral and mucosal delivery systems is discussed. These include lipid-based systems such as liposomes and immunostimulating complexes, as well as polymeric microspheres. In addition, developments in needle-free, dermal delivery devices such as jet injectors, microneedles and patches are presented.

A combined approach of vesicle formulations and microneedle arrays for transcutaneous immunization against hepatitis B virus

In the search for an optimal approach for the transcutaneous immunization (TCI) of hepatitis B surface antigen (HBsAg), two vesicle formulations, L595 vesicles (composed of sucrose-laurate ester and octaoxyethylene-laurate ester) and sPC vesicles (composed of soybean-phosphatidylcholine and Span-80) were prepared and characterized in vitro and in vivo. HBsAg was associated to the vesicles, resulting in sPC-HBsAg vesicles (±170nm) with 79% HBsAg association and L595-HBsAg vesicles (±75nm) with only 29% HBsAg association. The vesicles induced in mice via TCI an antibody response only when the skin was pretreated with microneedles. This response was improved by the adjuvant cholera toxin. The sPC-HBsAg vesicle formulations showed to be the most immunogenic for TCI, which was related to the higher degree of HBsAg association.

Needle-free vaccine delivery

The need for minimally invasive delivery methods is urgent. As the number of registered vaccines increases, so does the number of injections. The use of sharps can be unsafe and needle immunisation is less suitable for mass immunisations during emergencies such as pandemics or bioterrorist attacks. The approach of combining vaccines has limitations due to high development costs, risk of pharmaceutical or immunological interference and economic risks. Advancements in the development of alternatives to injection with syringes and needles are discussed in this paper, and include: mucosal vaccination, injection without needles and vaccine delivery via the skin.

Diphtheria toxoid-containing microparticulate powder formulations for pulmonary vaccination: preparation, characterization and evaluation in guinea pigs

In this study, the potential of N-Trimethyl chitosan (TMC, degree of quaternization 50%) and dextran microparticles for pulmonary delivery of diphtheria toxoid (DT) was investigated. The antigen-containing microparticles were prepared by drying of an aqueous solution of polymer and DT through a supercritical fluid (SCF) spraying process. The median volume diameter of the dry particles, as determined by laser diffraction analysis, was between 2 and 3 microm and the fine particle mass fractions smaller than 5 microm, as determined by cascade impactor analysis, were 35 and 56% for the dextran and TMC formulations, respectively. The water content of the particles as measured by Karl-Fischer titration was 2-3% (w/w). Pulmonary immunization with DT-TMC microparticles containing 2 or 10 Lf of DT resulted in a strong immunological response as reflected by the induction of IgM, IgG, IgG subclasses (IgG1 and IgG2) antibodies as well as neutralizing antibody titers comparable to or significantly higher than those achieved after subcutaneous (SC) administration of alum-adsorbed DT (2 Lf). Moreover, the IgG2/IgG1 ratio after pulmonary immunization with DT-TMC microparticles was substantially higher as compared to SC administered alum-adsorbed DT. In contrast, pulmonarily administered DT-dextran particles were poorly immunogenic. Among the tested formulations only pulmonarily administered DT-containing TMC microparticles induced detectable pulmonary secretory IgA levels. In conclusion, in this paper it is demonstrated that TMC microparticles are a potent new delivery system for pulmonary administered DT antigen.

Minimally invasive photodynamic therapy (PDT) for ablation of experimental rat glioma

OBJECTIVE

The feasibility of using ALA-mediated photodynamic therapy (PDT) tumor ablation as a minimally invasive treatment alternative for malignant brain tumors was evaluated in a rodent model. Treatment efficacy and side effects were evaluated with MRI, histopathology and survival rates.

METHODS

BT (4)C orthotopic brain tumors were induced in BD-IX rats. At various time intervals following tumor induction the animals were given 5-aminolevulinic acid (ALA) and 4 hours later optical fibers were inserted directly into the tumor without mechanical debulking or cranial decompression. A 3-day course of steroid treatment was initiated immediately prior to PDT.

RESULTS

All untreated animals inevitably died within one month after tumor implantation (28.5 +/- 2.5 days). Complete tumor eradication was achieved in only 1/17 rats, but a significant increase in survival was obtained in the group of animals receiving 125 mg/kg ALA and 26 Joules of light fluence. Histopathology revealed large areas of central tumor necrosis, although clusters of viable tumor cells were often found at the tumor periphery. Pronounced edema in the necrotic tumor center as well as in the surrounding brain, and along white matter tracts was evident in all the brains studied from PDT-treated animal.

CONCLUSION

This study suggests that ALA-mediated PDT may become a promising alternative therapy for the minimally invasive treatment of brain tumors. A judicious choice of PDT regimens that minimizes inflammatory responses through the use multiple fractionated long-term treatment protocols would likely be required.

Integrated neuronavigation system with intraoperative image updating

OBJECTIVE

Recently, MRI has entered the field of image-guided surgery as a new intraoperative imaging modality. In spite of its obvious benefits, this type of iMRI scanner has some drawbacks that have limited its utilization. The goal of the work presented here was to overcome some of these disadvantages.

METHODS

A system that allows intraoperative images to be acquired during surgery and have the ability to conduct surgery outside the constraints of the narrow gap of the open magnet was implemented. Ability to conduct tasks inside the scanner with real-time image guidance was also maintained. The system allowed navigation with neuronavigation tools both inside the gap of an open magnet and outside the magnet, utilizing two different optical camera-sets and a dynamic reference frame. Automatic patient registration was implemented.

RESULTS

The average difference between tracking position measured outside and inside the magnet was 0.8 +/- 0.1 mm.

CONCLUSION

In the work presented in this note we have introduced a dynamic reference frame to compensate for transport of the patient to a location outside the scanner employing a second camera set. The integrated system showed adequate accuracy.

Impact of Intraoperative MRI on the Surgical Results for High-Grade Gliomas

OBJECTIVE

The impact of intraoperative MRI (iMRI) on the surgical procedure, patient outcome and median survival for a series of patients harbouring high-grade gliomas forms the basis of this study. Their outcome has been compared to a matched cohort of patients operated in a conventional manner to determine if the use of intraoperative MRI can be shown to improve the results of surgery and prognosis for this type of patient.

MATERIALS AND METHODS

32 microsurgical open craniotomies, performed in the intraoperative iMRI scanner for grade IV supratentorial gliomas, with follow-up periods of more than 2 months, were analyzed for this study. A group of 32 primary high-grade glioma patients (no recurrent tumors) were matched for age, preoperative clinical grade, gender and histology and operated during a corresponding time interval in a conventional manner acted as controls.

RESULTS

All 64 patients were examined and analyzed for the occurrence of postoperative increased neurological morbidity or death. No complications directly related to the intraoperative scanning procedures were observed and no intraoperative death occurred in either group. The average operating time in the intraoperative scanner was 5.1 hours and was significantly longer than in the conventional OR (3.4 hours). The mean overall survival time for the 32 patients in the study group was 14.5 months (95 % confidence interval 12.0 - 16.6) compared to 12.1 months (95 % confidence interval 10.2 - 14.1) for the matched control group.

CONCLUSION

Although iMRI is an effective way of imaging residual tumor, this study could not demonstrate an increased efficacy of surgery utilizing this technique for patients harbouring grade IV gliomas compared to more conventional methods. No statistical significance was noted between the two groups (p = 0.14). The complication rate was within the range reported for other series, in both control as well as the study group.

Image-guided stereotaxy in the interventional MRI

BACKGROUND

Stereotactic procedures employing frame-based systems and utilizing pre-operative MR or CT have several shortcomings such as long procedure time, patient discomfort and transport, poor fail-safe capabilities and targeting inaccuracies due to brain shift. Conducting all procedural steps in an interventional MRI has the potential of alleviating some of these deficiencies.

METHODS

A stereotactic system consisting of a skull-mounted mechanical positioning device and customized navigation software has been developed. The accuracy of this system was tested within an interventional MRI employing a skull phantom.

RESULTS

The mean distance between the targets hit and the planned target coordinates was 0.70 mm +/- 0.3 mm with a maximum distance of 1.3 mm.

INTERPRETATION

The results indicate that the proposed stereotactic system can be used for stereotactic procedures in the interventional MRI.

Development of a novel indwelling balloon applicator for optimizing light delivery in photodynamic therapy

BACKGROUND AND OBJECTIVE

A human glioma spheroid model is used to investigate the efficacy of different light delivery schemes in 5-aminolevulinic acid (ALA)--mediated photodynamic therapy (PDT). The results provide the rationale for the development of an indwelling balloon applicator for optimizing light delivery.

STUDY DESIGN/MATERIALS AND METHODS

Human glioma spheroids were incubated in ALA (100 or 1000 microg /ml-1) for 4 hours and subjected to various light irradiation schemes. In one set of experiments, spheroid survival was monitored as a function of light fluence rate (5-200 mW cm-2). In all cases, spheroids were exposed to fluences of either 25 or 50 J cm-2. In a second study, the effects of repeated weekly PDT treatments, using sub-threshold fluences, were investigated. One group of spheroids was subjected to three treatments using fluences of 12, 12, and 25 J cm-2. Results were compared to spheroids receiving single treatments of either 12 or 25 J cm-2. A fluence rate of 25 mW cm-2 was used for all three groups of spheroids. In all cases, the effect of a given irradiation scheme was evaluated by monitoring spheroid growth.

RESULTS

Low fluence rates produce greater cell kill than high fluence rates. The minimum effective fluence rate in human glioma spheroids is approximately 10 mW cm-2. Repeated weekly PDT treatments with sub-threshold fluences result in significant cell kill. In spheroids surviving the PDT treatments, growth is suppressed for the duration of the treatment period.

CONCLUSION

The results of the in vitro studies support the development of an indwelling balloon applicator for the delivery of light doses in long term multi-fractionated PDT regimens.

Intracerebral abscess caused by Nocardia otitidiscaviarum in a renal transplant patient--cured by evacuation plus antibiotic therapy

We present a 50-year-old female who experienced generalized convulsion 3 months after a successful cadaveric renal transplantation. The first cerebral CT scan indicated cerebral frontal infarction. Repeat CT some days later revealed progressive lesions, and a highly malignant tumor or abscess was suspected. Antifungal and broad-spectrum antibacterial therapy was initiated. Cerebral MRI could not differentiate between these conditions, but a neutrophil granulocyte scan strongly suggested an infectious process. A stereotactic puncture of the frontal lobe was followed by temporary improvement. A severe progressive left-sided hemiparalysis gave indication for a craniotomy with evacuation of the abscess 9 days later. Culture of aspirated pus yielded growth of a gram-positive, rod-shaped bacterium, later identified as Nocardia otitidiscaviarum by sequencing the 16S rRNA. The patient was treated with meropenem plus rifampicin intravenously for 6 weeks followed by oral ciprofloxacin and rifampicin for 2 months. Due to pharmacokinetic interaction with rifampicin, the prednisolone dose was doubled, and the dose of tacrolimus had to be tripled for maintenance of adequate trough concentrations. Five months following cessation of antibiotic treatment, the patient has regained normal strength and function in her left-sided extremities and has a serum creatinine level of about 160 micromol/l (1.8 mg/dl).

Photodynamic therapy of human glioma spheroids using 5-aminolevulinic acid

The response of human glioma spheroids to 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) is investigated. A two-photon fluorescence microscopy technique is used to show that human glioma cells readily convert ALA to protoporphyrin IX throughout the entire spheroid volume. The central finding of this study is that the response of human glioma spheroids to ALA-mediated PDT depends not only on the total fluence, but also on the rate at which the fluence is delivered. At low fluences (< or = 50 J cm-2), lower fluence rates are more effective. At a fluence of 50 J cm-2, near-total spheroid kill is observed at fluence rates of as low as 10 mW cm-2. The fluence rate effect is not as pronounced at higher fluences (> 50 J cm-2), where a favorable response is observed throughout the range of fluence rates investigated. The clinical implications of these findings are discussed.

Photodynamic therapy of human glioma spheroids using 5-aminolevulinic acid

The response of human glioma spheroids to 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) is investigated. A two-photon fluorescence microscopy technique is used to show that human glioma cells readily convert ALA to protoporphyrin IX throughout the entire spheroid volume. The central finding of this study is that the response of human glioma spheroids to ALA-mediated PDT depends not only on the total fluence, but also on the rate at which the fluence is delivered. At low fluences (< or = 50 J cm-2), lower fluence rates are more effective. At a fluence of 50 J cm-2, near-total spheroid kill is observed at fluence rates of as low as 10 mW cm-2. The fluence rate effect is not as pronounced at higher fluences (> 50 J cm-2), where a favorable response is observed throughout the range of fluence rates investigated. The clinical implications of these findings are discussed.

Neuronavigation in intraoperative MRI

OBJECTIVE

We describe the development and implementation of an image-guided surgical system combining the best features of conventional frameless stereotactic systems and the recently developed superconductive vertically configured intraoperative magnetic resonance scanner. The incorporation of intraoperatively updated magnetic resonance imaging (MRI) data sets into the neuronavigation computer overcomes one of the main disadvantages of these systems, i.e., intraoperative brain shift.

METHODS

The integrated system consists of a 0.5-T MRI scanner (Signa SP General Electric Medical Systems, Milwaukee, WI), a neuronavigation computer with associated software (OTS Radionics, Burlington, MA), and an emulation program linking the two. The scanner has a 60-cm-wide vertical gap where both imaging and surgery are conducted, in-bore infrared linear cameras and monitors for interactive surgical neuronavigation, and flexible surface coils specially designed for surgery.

RESULTS

Phantom studies showed navigational accuracy to be better than that obtained using conventional preoperative images and surface markers for patient registration. Our initial 17 cases using this integrated system comprised 16 craniotomies and one biopsy, and demonstrated decreased operative duration, greater frequency of interactive image guidance utilization, and better assessment of the progress of surgery compared to the cases previously done in the intraoperative MRI.

CONCLUSION

This initial study of the addition of frameless stereotactic systems to the basic intraoperative MRI concept has demonstrated its clinical usefulness. The use of the intraoperative MRI greatly reduces the basic weakness of neuronavigation inaccuracy due to target shift. The surgical procedure performed in the imaging volume of the MRI scanner eliminates the problems of patient or scanner transport during the procedure. Immobilization of the patient throughout the procedure eliminated the need for reregistration of the patient, by taking advantage of the fixed camera system in the bore of the MRI system.

Intraoperative image-directed dye marking of tumor margins

The incorporation of interactive image guidance during intracranial tumor surgery offers the possibilities of reduced operative trauma, shorter operation time, greater precision, and an increased understanding of complex anatomy and pathology. A basic weakness with these systems though is that they cannot account for movement of target points due to brain shift by draining of CSF or removal of pathology during the operative procedure. We have developed a stereotactic (frameless) guided injector probe for marking the tumor boundary with dye injection in conjunction with a neuronavigation system. The device consisted of a rigid blunt hollow probe (2 mm dia.) with 4 small side holes at the tip. The catheter is mounted in a holder equipped with 3 LEDs supplying guidance information for the neuronavigation system. A small manual aliquoting pump delivers a measured amount of dye in each track. Isotonic methylene blue was injected in 6 to 8 tracks around the periphery of the tumor as determined by the contract ring in MR scans. The dye was injected using image-directed guidance before resection of the tumor was started (often with the dura intact). Tumor tissue could then be resected until the dye became visible at the tumor boundary. Identification of the dye in the tissue was enhanced with the use of the operating microscope. The 3-dimensional position of the dye track could be determined at the end of tumor resection and compared with its initial position giving a good estimate of local brain shift. The method has proved especially helpful for the resection of large gliomas allowing for a more radical operative result.

An indwelling brachytherapy balloon catheter: potential use as an intracranial light applicator for photodynamic therapy

An indwelling balloon applicator developed for postoperative intracavity afterloading brachytherapy was evaluated for photodynamic therapy (PDT). Following tumor resection, the applicator is positioned in the center of the resultant cavity and the balloon is inflated with a scattering solution. The liquid-filled balloon stabilizes the resection cavity ensuring a constant and simple geometric shape during treatment. The catheter is brought out through the skin and adjusted so that 1-2 cm projects above the scalp surface. Measurements of light distribution in a phantom model surrounding the balloon catheter, show that it may be used to deliver sufficiently uniform light doses during PDT. The light distribution is uniform to within 5% when the balloon is filled with a scattering medium. Based on simple assumptions, it is shown that the applicator can be used to deliver a sufficient optical dose to brain tissue at a depth of 1 cm in less than 1 h. The applicator has already been used for brachytherapy in 72 patients with few complications. A new treatment protocol employing the combination of both fractionated intracavity brachytherapy and PDT is currently being planned.

Intracavity fractionated balloon brachytherapy in glioblastoma

In order to reduce hospitalisation time for patients receiving postoperative radiotherapy a phase I-II study of intracavity balloon brachytherapy was instituted. An indwelling balloon catheter was implanted during the closing phase of the initial operation. Starting on the second or third postoperative day the catheter was afterloaded with a high dose rate isotope via a remotely controlled afterloading system. The treatment consisted of 10-12 fractions over a period of 5-6 days, with each treatment session requiring approximately 15 minutes. No external beam radiation was given. Forty-four newly diagnosed patients were treated. A total dose of either 60 Gy (33 patients) or 72 Gy (11 patients) was given. The overall median survival was 11.7 months, (range 2.7-50.9). The treatment was well tolerated and none of the applicators were removed prematurely. The total median hospital stay for this group of patients was significantly reduced compared to more conventional protocols. This study indicates that intracavity high dose rate balloon brachytherapy can achieve survival rates equivalent to those of conventional radiotherapy and is both cost and time efficient.

Growth of precultured human glioma specimens in nude rat brain

OBJECT

The aim of this study was to develop an improved animal model for brain tumor study. The need for better and more relevant brain tumor models is generally acknowledged. Glioma tissue can be cultured directly from the biopsy specimen as tumor spheroids. Using such precultured tissue, a new in vivo model for studying human gliomas was established.

METHODS

Precultured small tumor spheroids (< 300 microm) prepared from cell lines or tumor biopsy fragments were injected into the brains of immunodeficient rats by using a 5-microl Hamilton syringe that had a piston in the needle. Tumors could be established by injecting a single spheroid derived from the U-87MG cell line, whereas inoculation of 10 spheroids resulted in a tumor take comparable to that attained with injection of 10(6) single cells. Biopsy specimens obtained from six patients who underwent surgery for glioblastoma multiforme were cultured as organotypic spheroids for 11 to 18 days before inoculation into the rats. The animals were killed 3 months after spheroid implantation. Microscopic examination revealed tumor growth in 87.5 to 100% of the animals inoculated with tumor spheroids from all but one of the tumor biopsy specimens. Extensive invasion and cell migration along the nerve tracts of the corpus callosum was found in tumors that originated from four of the six biopsy specimens.

CONCLUSIONS

This approach, in which spheroids from precultured biopsy specimens are injected into the brains of immunodeficient animals, provides new means for experimental studies of human malignant brain tumors in a clinically relevant animal model.

Prognostic significance of CT contrast enhancement within histological subgroups of intracranial glioma

We report the prognostic significance of tumor CT contrast enhancement within histological subgroups in 831 consecutive adult glioma patients of high-grade (n = 516) and low-grade (n = 315) histology. In the present report, a negative prognostic factor is associated with shortened survival.

METHODS

Survival analysis including Kaplan-Meier plots, log-rank tests, Cox analysis, and Aalen's linear model as implemented in SPSS and S-PLUS.

RESULTS

Sensitivity and specificity of contrast enhancement as a test for high-grade glioma was 0.87 and 0.79, respectively. Enhancement was a strong negative prognostic factor comparable to high-grade histology in the total patient population. Enhancement was also a negative prognostic factor within the subgroups adult high-grade (Grade 3-4), anaplastic (Grade 3), and low-grade (Grade 1-2) gliomas (p < 0.001). The prognostic implications of initial enhancement declined in high-grade patients surviving beyond 36 months. Tumor contrast enhancement or calcifications (in parentheses) were present in 96% (3.6%) of glioblastomas, in 87% (7.4%) of high-grade gliomas, in 56.5% of anaplastic gliomas, and in 21% (16.2%) of low-grade gliomas. Calcification was a positive prognostic factor within the high-grade group of patients (p < 0.0001).

CONCLUSION

Enhancement was a major prognostic factor comparable to high-grade histology in this glioma patient population. Enhancement was a negative prognostic factor within each of the adult subgroups high-grade, anaplastic (grade 3), and low-grade gliomas. Enhancement was strongly associated with but not pathognomonic for high-grade histology.

Prevalence and prognostic significance of epilepsy in patients with gliomas

The aim of this study was to evaluate the prevalence and prognostic significance of epilepsy in 1028 patients diagnosed in the computer tomography (CT) era with histological low- or high-grade intracranial gliomas. Survival analysis included Kaplan-Meier plots, log-rank tests, logistic regression and Cox's analysis as implemented in the SPSS statistical package. Epilepsy was a positive univariate (P < 0.0001) and multivariate, (P < 0.03) prognostic factor for survival in the total patient group (n = 1028, relative risk of death 0.83, 95% confidence interval (CI) 0.70-0.98) as well as in the high-grade patient group (n = 649, relative risk of death 0.80, 95% CI 0.66-0.96), but not in the group of low-grade glioma patients (P > 0.2). The prevalence of epilepsy in glioblastoma patients was 251/512 (49%), 95/137 (69%) in anaplastic gliomas, and 322/379 (85%) in patients with low-grade gliomas, with 97 of the 102 T1 low-grade subgroup (95%) having epilepsy, indicating that the presence of epilepsy may select patients for early radiological diagnosis. The frequency of epilepsy at presentation decreased with age in high-grade glioma patients, and increased with age in low-grade glioma patients to a plateau in the fourth decade of life (P < 0.01). The prevalence of epilepsy in patients with histological intracranial gliomas varied with patient age and tumour histology, with low-grade patients having the highest prevalence. Epilepsy was a significant positive prognostic factor except in patients with low-grade gliomas, and may select low-grade patients for early diagnosis.

Survival, prognostic factors, and therapeutic efficacy in low-grade glioma: a retrospective study in 379 patients

PURPOSE

We report survival, prognostic factors, and treatment efficacy in low-grade glioma.

PATIENTS AND METHODS

A total of 379 patients with histologic intracranial low-grade glioma received post-operative radiotherapy (n = 361) and intraarterial carmustine (BCNU) chemotherapy (n = 153). Overall survival and prognostic factors were evaluated with the SPSS statistical program (SPSS Inc, Chicago, IL).

RESULTS

Median survival (all patients) was 100 months (95% confidence interval [CI], B7 to 113); in age group 0 to 19 years (n = 41), 226 months; in age group 20 to 49 years (n = 263), 106 months; in age group 50 to 59 years (n = 49), 76 months; and for older patients (n = 26), 39 months. Projected survival at 10 and 15 years was 42% and 29%, respectively. Patient age, World Health Organization (WHO) performance status, tumor computed tomography (CT) contrast enhancement, mental changes, or initial corticosteroid dependency were significant independent prognostic factors (p < .05), while histologic subgroup, focal deficits, presence of seizures, prediagnostic symptom duration, tumor category, and tumor stage were not. Patients aged 20 to 49 years with no independent negative prognostic factors (n = 132) had a median survival time of 139 months versus 41 months in patients with two or more factors (n = 33). Patients who presented with symptoms of expansion (n = 97) survived longer when resected (P < .03); otherwise no survival benefit was associated with initial tumor resection compared with biopsy. Intraarterial chemotherapy and radiation doses more than 55 Gy were not associated with prolonged survival. Among 66 reoperated patients, 45% progressed to high-grade histology within 25 months.

CONCLUSION

Prognosis in low-grade glioma following postoperative radiotherapy seems largely determined by the inherent biology of the glioma and patient age at diagnosis.

Incorporation of ultrasonic imaging in an optically coupled frameless stereotactic system

Frameless stereotactic interactive tracking systems relate a point in the surgical field to a corresponding point on the patients MR or CT scans in multiple planes. A basic weakness with these systems is that they cannot compensate for movement of target points due to brain shift caused by CSF drainage or lesion removal. Real time images can be obtained using ultrasonic techniques but the poor quality and definition and the ill-defined scan plane make interpretation difficult and reduce the usefulness of this modality. The authors have combined these two modalities by mounting light emitting diodes (LEDs) on the ultrasonic probe, thus allowing a "virtual tip" to be developed in the centre of the ultrasonic beam, and tracked via an optically coupled frameless stereotactic system (Radionics, OTS). This has allowed a direct correlation between pre-operative MR and the per-operative ultrasonic images using reformatted MR images. Ultrasound images are obtained through a separate skull opening and the image plane is determined by the position of the virtual tip. The ultrasonic and MR images are presented side by side for visual comparison. Minimally invasive tumour resection or haematoma removal could be carried out under ultrasonic guidance with direct interactive relation to the preoperative MR scans. Alternatively interactive image directed surgical procedures can be up-dated in real time by dynamic ultrasonic images taken in clearly defined scan planes.

Interactive image directed neurosurgery: patient registration employing the Laitinen stereo-adapter

Fiducial markers visible on both imaging scans and the patient are a convenient and accurate method to register the patients head in stereotactic space preceeding an interactive image directed neurosurgical procedure. We have been using the Laitinen non-invasive relocatable stereo-adapter to carry the fidcucial markers both during the imaging and patient registration process. Since the adapter can be accurately remounted the surgical procedure can take place at any time interval after the imaging study. To compare registration accuracy studies were performed using a phantom carrying both surface fiducial markers and fiducial markers mounted on the stereo adapter. We have found that total system accuracy using either surface or adapter mounted markers and an optical tracking system is in the range of 3-5 mm and is acceptable for a broad range of neurosurgical applications.

[Prognosis in primary tumors of the central nervous system. A patient material from the Norwegian Radium Hospital 1960-94]

We present the results of a retrospective survey of 1,218 patients treated at the Norwegian Radium Hospital during the years 1980-94 for primary tumours of the central nervous system. Median survival for patients with glioblastoma (n = 492) was 12 months, for patients with anaplastic astrocytoma (n = 83) 25 months, astrocytoma (n = 260) 95 months, oligodendroglioma (n = 85) 74 months, mixed glioma (n = 68) 65 months, and medulloblastoma (n = 53) 109 months. Median survival for patients with brain stem tumours (n = 37) was nine months, while 74% of patients with tumours in the pineal region (n = 38) survived for five years. The histology and localisation of the tumour, as well as age and functional status, are important prognostic factors for survival in patients with primary CNS tumours.

Implementation of a stereotactic microscope using an optically coupled tracking system

Image-directed neurosurgical systems allow the correlation of a point in the operative field to a corresponding point on the patient's CT/MR scans. We have modified a surgical microscope by mounting three light-emitting diodes (LEDs) on a small frame attached to the microscope. The operative field was registered to the MR scans by indexing four MR/patient visible fiducial points with a LED pointing device. To calibrate the microscope, the probe point was focused and centered in the microscopic field of view with the aid of cross hairs in the microscope ocular. The focal plane of the microscope could now be tracked in addition to the probe tip. During surgery the point of interest is centered in the cross hairs and brought into focus, and the corresponding point is indicated in three planar views on MR scans.

Fractionated stereotactic radiation therapy for intracranial arteriovenous malformations

Fractionation of radiotherapy is a radiobiological advantage because the radiation effects on healthy brain tissue are reduced. We used fractionated stereotactic radiotherapy for cerebral arteriovenous malformations employing a modified linear accelerator and a noninvasive stereoadaptor. The treatment was given in two sessions (1,400 cGy x 2). Control angiography at least 2 years after treatment was performed on 20 patients. The malformation was completely eliminated in 14 of 15 patients with small arteriovenous malformations. None of the 5 patients with large malformations had their lesion eliminated, but in 4 the malformation was significantly reduced. Fractionated stereotactic radiation therapy using a conventional accelerator is an effective and safe technique in the treatment of intracranial arteriovenous malformations and compares favorably to radiosurgery.

Long-term results after percutaneous retrogasserian glycerol rhizotomy in patients with trigeminal neuralgia

We have evaluated the long-term results of percutaneous retrogasserian glycerol rhizotomy (PRGR) in 60 patients with classical trigeminal neuralgia. Complete initial pain relief was achieved in 93% of the patients. Numbness was initially reported by 3/4 of the patients and at follow-up by 1/3, while long-lasting dysaesthesias were an important side effect in 38% of previously untreated patients. The half-life of the method was 47 months in our material, and this figure compares favourably with other previously reported series. The method carries a significant risk of long-lasting and troublesome sensory disturbances. Another disadvantage of the method, reported in the present long-term study, was the high incidence of recurrent neuralgia. We are unable to identify predictors of recurrent neuralgia after PRGR, although major recurrences were more common in patients with unchanged facial sensation postoperatively. In conclusion, PRGR offers safe and reliable relief of pain in patients with trigeminal neuralgia. In spite of the high incidence of recurrence and of long-lasting dysaesthesias it is, in our opinion, the method of choice in the elderly, and particularly suitable for patients at high risk.

Prognostic factors in malignant gliomas with special reference to intra-arterial chemotherapy

Survival was analyzed in 173 patients with malignant gliomas to study the importance of possible pretreatment prognostic factors. Seventy-nine of these patients received preirradiation intra-arterial chemotherapy with BCNU combined with vincristine intravenously and procarbazine orally; the others received only postoperative whole-brain irradiation. To judge by univariate and multivariate analyses the most important pretreatment prognostic factors were histology, corticosteroid dependency, pretreatment performance status and frontal lobe location of the tumors. Patients with anaplastic astrocytoma, not corticosteroid-dependent, with pretreatment performance status of 0-2 and with a frontal lobe location of the tumor seemed to benefit most from preirradiation chemotherapy.

99mTc-hexamethylpropyleneamine oxime leukocyte scintigraphy and C-reactive protein levels in the differential diagnosis of brain abscesses

The demonstration and accurate localization of intracerebral mass lesions are commonly performed with computerized tomography (CT), which often cannot determine the nature of the lesion. As an aid in the differential diagnosis between brain abscess and neoplasm, the authors have evaluated both 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) leukocyte scintigraphy and the serum C-reactive protein level. Of 23 patients with intracranial mass lesions, 22 individuals showed ring-like contrast enhancement on CT scans; the one exception was a patient treated for a meningioma who had a negative CT scan despite clinical suspicion of intra- or extracranial abscess. The final diagnosis was invariably established by microscopic examination of tissue specimens. In 10 patients the final diagnosis was brain abscess; the other 13 patients harbored a brain neoplasm (glioma in nine, astrocytoma in one, and metastasis in three). The 99mTc-HMPAO leukocyte scintigraphy detected all cases of abscess. There were no false-positive results. An elevated C-reactive protein level (> 13 mg/liter) was found in all but one patient with abscess and in three patients with neoplasm; two of these three patients had dental root infections which could account for the elevation of C-reactive protein. It is concluded that 99mTc-HMPAO leukocyte scintigraphy should be performed when there is a possibility that a brain abscess may exist. Any steroid treatment should be discontinued for 48 hours prior to leukocyte scintigraphy. Also, C-reactive protein determination should be performed and is useful even when steroids are given.

Combined intra-arterial chemotherapy followed by radiation in astrocytomas

Seventy-five patients harboring astrocytomas received 4 cycles of infra-ophthalmic carotid injections of BCNU, combined with vincristine intravenously and procarbazine orally. All of the patients thereafter, received radiation therapy. The five year survival was 73% for all patients. The age of the patients had no significant impact on survival. The treatment results were compared with the results of 57 patients with astrocytomas who were treated with surgery followed by radiation in the same period. These 57 patients had a 5 year survival of 45% with a five year survival in patients < or = 40 years and patients > 40 years of 70% and 22%, respectively (p < 0.05). In multivariate survival analysis of the BCNU group and radiation group together, treatment group and corticosteroid dependency were the only prognostic factors. No leukoencephalopathy was seen during the treatment or in the follow-up of the patients. We conclude that pre-radiation intra-arterial chemotherapy can be given without significant morbidity and produces an improvement in survival in patients older than 40 years.

Pre-radiation chemotherapy in glioma patients with poor prognostic factors

Nineteen patients in an age group from 56-67 years (mean age 62.5 years) with histologically verified glioblastoma multiforme were treated with chemotherapy consisting of two cycles of oral CCNU, intravenous vincristine and oral procarbazine prior to radiation therapy. Ten of the patients had stable disease, monitored by CT scan and neurological examination, and received whole brain radiation. The median survival was 12 months. Nine patients who had progressive disease during chemotherapy did not receive radiation treatment and were put on palliative treatment with dexamethasone. This group had a median survival of 3 months. The median survival in all of the 19 patients who entered the study was 9 months which was comparable to the survival of 56 patients with glioblastoma multiforme who, in a retrospective study, received post-operative radiotherapy. The most important factor predicting survival was steroid-dependency after surgery.

High incidence of serious side effects of high-dose dexamethasone treatment in patients with epidural spinal cord compression

Twenty-eight consecutive patients were given high-dose dexamethasone (96 mg i.v. loading dose, decreasing doses to zero in 14 days) and radiotherapy for epidural spinal cord compression due to malignant disease. There were eight events classified as side effects of the dexamethasone treatment. Four of these were considered as serious (one fatal ulcer with haemorrhage, one rectal bleeding and one gastrointestinal perforation from undetermined origins, and one perforation of the sigmoid colon) giving a total rate of serious side effects of 14.3 percent. Due to the high incidence of serious side effects of the high dexamethasone dose, the regimen was abandoned in favor of a standard dexamethasone dose of 16 mg daily reduced to zero in 14 days. There were three events classified as side effects, but none were considered as serious in 38 consecutive patients receiving this dose. The differences both in total number of side effects and number of serious side effects are statistically significant. There was no significant difference in the number of ambulant patients in the group that received the high dexamethasone dose. We conclude that the high dexamethasone dose in our experience gives an unacceptably high incidence of serious side effects and we have therefore abandoned the regimen in favour of a more standard dexamethasone dose.

Combined intra-arterial and systemic chemotherapy for recurrent malignant brain tumors

Seventy-nine patients harboring recurrent brain tumors received four cycles of infraophthalmic carotid injections of 160 mg of carmustine. Two milligrams of intravenous vincristine and 50 mg of oral procarbazine was also administered three times daily for 1 week in conjunction with each BCNU treatment. The response rate was 60% with a median survival for patients with astrocytomas, anaplastic astrocytomas, and glioblastomas of 32, 20, and 6.5 months, respectively. The median survival of the responding patients was 20 months, and the survival at 30 months was 45%. The survival in patients not responding to treatment was 5 months, reflecting the natural history of the tumor. There have been no deaths related to the treatment procedure. No incidents of severe or permanent eye complications or leukoencephalopathy were observed. Based on multivariate survival analysis, only patients with a good performance status who are not steroid dependent are candidates for this treatment.

Primary malignant lymphoma of the brain. A report of 24 cases from the Norwegian Radium Hospital

Between 1975 and 1987, 24 patients with primary central nervous system lymphoma were seen and treated at the Norwegian Radium Hospital. The overall median survival was 24 months. Patients with poor performance status (WHO 3-4) had a median survival of 3 months whereas patients with good performance status (WHO 0-2) had a median survival of 40 months (p < 0.0001). Patients who were not steroid-dependent after operation had a better survival than those patients who were steroid-dependent (p = 0.02). Nine patients were still living without evidence of disease at last follow-up, 18-130 months after the initial treatment.

[Treatment of spinal cord compression caused by malignant disease]

Patients suffering from metastatic spinal cord compression can be treated with decompressive surgery and/or radiotherapy. The best treatment regimen remains to be established. In the present paper we report our experience of a therapeutic regimen with main emphasis on radiotherapy, but where selected patients were treated with laminectomy followed by radiotherapy. 67 patients were treated during a two year period, 60 with radiotherapy as the sole treatment modality. The ambulation rate after treatment was 56.7%. Degree of loss of neurological function before treatment and tumour histology were prognostic factors for a successful outcome, defined as the patient's ability to walk after treatment. We emphasize the importance of starting treatment before development of advanced neurological deficits.

Combined intra-arterial chemotherapy and irradiation of malignant gliomas

Seventy-nine patients with malignant gliomas (19 anaplastic astrocytomas and 60 glioblastoma multiforme) received 4 cycles of infra-ophthalmic carotid injection of 160 mg carmustine, 2 mg vincristine IV and procarbazine orally 50 mg 3 times daily for 1 week, followed by whole-brain irradiation, with a midpoint dose of 54 Gy/6 weeks. Response, judged by CT-scan, was seen in 31 out of 57 evaluable patients with a median survival of 30 months and 40% survival at 3 years. In all patients who responded to the treatment, a tumour regression was seen on CT-scan after chemotherapy before irradiation. In the 26 patients with progressive disease under chemotherapy, the median survival was 5 months. None of the patients who had progressive disease during chemotherapy had benefit from irradiation. The most important prognostic factors were good pretreatment performance status, glucocorticoid dependency and age. Few serious side-effects of the angiographic procedure were seen. Leukoencephalopathy was not observed in this study.

Intra-arterial BCNU in the treatment of recurrent medulloblastoma

Two patients with recurrent medulloblastomas were treated with combined oral and intravenous chemotherapy followed by intra-arterial BCNU. The 7 days course of oral and intra-venous chemotherapy consisted of CCNU and Procarbazin orally and Vincristine intravenously (PCV), repeated after 6 weeks. Intra-arterial chemotherapy consisted of 4 cycles of BCNU. Both patients responded well to treatment, evaluated by CT scans. One of the patients died of a new local recurrence 6 months after initiation of chemotherapy, whereas the other patient remains well, without CT evidence of tumour 36 months after the start of the treatment. No serious adverse side-effects related to the treatment were seen.

Reversible oedema and necrosis after irradiation of the brain. Diagnostic procedures and clinical manifestations

One hundred and twelve patients with primary brain tumour were followed every 3 months during and after brain irradiation and chemotherapy with brain scanning, EEG and neurological examination. Early delayed radiation reactions were seen in 6 patients. The symptoms developed 2-8 months after irradiation and lasted for 2-3 months. Two types of reactions were observed. One mild form appeared after 2-3 months and was characterized by low-attenuated expansive areas within the irradiated volume, without contrast enhancement on CT scan. Severe reactions appeared in some patients after 6 months, with exacerbation of earlier clinical signs and contrast enhancing lesions on CT. Regression of the CT finding was seen after 3 months. Recognition of this syndrome is important, as a new neurosurgical procedure might cause lasting neurological sequelae in patients who otherwise would recover without treatment.

Immunomagnetic separation of infiltrating T lymphocytes from brain tumors

Tumor-infiltrating lymphocytes (TIL's) were isolated from human glioma biopsy specimens by immunomagnetic separation using T cell-specific monoclonal antibodies coupled to paramagnetic beads, and were expanded in culture with feeder cells and interleukin-2 (IL-2). The infiltrating cells from five of seven patients proliferated in culture. When tested after 2 to 3 weeks of culture, virtually all of the cells stained with antibodies against the CD2 and CD3 antigens. Most cells also expressed human leukocyte antigen class II molecules, while varying percentages of cells stained with antibodies against the IL-2 receptor and the CD4 and CD8 antigens. The cytotoxicity of the cultured TIL's against autologous and allogeneic glioma cells and the K562 and Daudi cell lines was measured and compared with that of lymphokine-activated killer (LAK) cells from the same patients. None of the TIL's showed significant cytotoxicity against these targets, whereas LAK cells lysed all of the targets.

[Intracranial stereotaxic external radiation using a linear accelerator]

The article describes a method making it possible to give high radiation doses to a localized volume of the brain while sparing normal surrounding brain tissue. The treatment consists of sending multiple narrow radiation beams from different directions to the volume of tissue to be treated by rotating the radiation source and the patient table in relation to each other. Mega-voltage radiation from a linear accelerator is used. A non-invasive stereotactic frame is mounted on the patient and a CT scan of the brain is performed to localize the center and extent of the tissue to be treated. The radiation treatment is then given by using the coordinates on the frame to assure that the center of rotation of the treatment table and the linear accelerator pass through the center of the volume of tissue. The method has been used to give radiation boosts after external radiation to brain tumours, and to treat patients with recurrent tumours. Small localized benign intracranial tumours and AV-malformations have also been treated.

Localization of brain tumors with a simple scalp-mounted fiducial device. Technical note

A method is described for marking the site of a tumor on the scalp based on information from computerized tomography (CT) scans. The technique employs a syrinx-shaped array of radiopaque catheters of varying length taped to the patient's scalp for visualization on the CT scan. Fiducial markings on the CT images allow the transfer of the tumor's location directly onto the scalp. The device can be placed anywhere on the scalp, including in a parasagittal position.

Comparison of in vitro glioma cell cytotoxicity of LAK cells from glioma patients and healthy subjects

Peripheral blood mononuclear cells from 11 glioma patients and 11 healthy control subjects were cultured in medium containing recombinant interleukin-2 for a period of 5 days. The cytotoxicity of these lymphokine-activated killer (LAK) cells was tested on chromium-51-labeled freshly prepared allogeneic glioblastoma cells, and on the cell lines K562 (natural killer cell (NK)-sensitive) and Daudi (NK-resistant). Peripheral blood mononuclear cells from all subjects showed high levels of cytotoxicity against these targets. There was no significant difference between the patients and the control group when LAK cytotoxicity was compared. Thus, although glioma patients are known to have depressed immunological reactivity, the cytotoxic capacity of LAK cells derived from glioma patients is similar to that of LAK cells from healthy control subjects. However, the glioma patients had significantly reduced numbers of mononuclear cells in their peripheral blood, possibly due to steroid treatment. Therefore, the volume of blood required to generate the same number of LAK cells was approximately three times larger from the glioma patients than from control subjects.

Human interleukin-2 activated cytotoxic cells kill autologous glioma cells in vitro

We have cultured peripheral blood lymphocytes (PBL) from glioblastoma patients in recombinant interleukin-2 (IL-2) containing medium for a period of 5 days. The cytotoxicity of these cells was tested on 51Cr-labelled autologous dissociated glioblastoma cells which had not been cultured. Significant cytotoxicity against glioma cells was observed in seven out of nine cases. IL-2 activated PBL from normal donors were equally cytotoxic against these glioma cells. Autologous lymphocytes activated by phytohaemagglutinin were also lysed in most cases, and the erythroleukemia cell line K562 was highly susceptible to the cytotoxic capability of the IL-2 activated PBL. In cold target inhibition experiments, K562 inhibited the cytotoxicity against both autologous and allogenic glioma cells, and glioma cells inhibited the cytotoxicity against K562. Following immunomagnetic separation, the IL-2 activated cells demonstrated cytotoxicity against glioma cells, K562 cells, and PHA blasts in both the CD8+ and the CD8- subsets.

Radioimmunoassay in microtiter plates. A convenient method for determining bound radiolabelled ligand

A radioimmunoassay was performed in the wells of casein-coated microplates employing 125I-labelled sheep anti-human second antibody. The antigen-antibody complexes were thereafter dislodged from the well walls using the detergent sodium dodecyl sulfate (SDS) and the entire contents of the wells were simultaneously absorbed into 48 cellulose acetate-absorbing cartridges. All 48 cartridges were transferred to counting vials and the radioactivity determined by standard gamma counting techniques. The particular advantage of the method described here is the ease with which the supernatants can be collected and transferred to counting vials with minimal handling of radioactive samples.