P14.01 Differential diagnosis of IDH mutant/IDH wildtype of glioma by using 11C-methionine, 11C-choline, and18F-fluorodeoxyglucose positron emission tomography

BACKGROUND

Positron emission tomography (PET) is important in noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 World Health Organization (WHO) classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification).Here we investigated the relationship between PET imaging using 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) and wildtype isocitrate dehydrogenase (IDH) (IDH-wt)/mutant IDH (IDH-mut) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification.

MATERIAL AND METHODS

In total, 105 patients with newly diagnosed cerebral gliomas (six diffuse astrocytomas [DAs] with IDH-wt, six DAs with IDH-mut, seven anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, five GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake values (SUVs) of the tumor/normal cortex mean SUV ratios (T/N ratios) for MET, CHO, and FDG were calculated; the mean T/N ratios of DA, AA, and GBM with IDH-wt/IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the three PET tracers.

RESULTS

There were significant differences in the mean T/N ratios for all three PET tracers between the IDH-wt and IDH-mut groups including all histological classifications (p<0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all three PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all three PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p<0.001). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that of the IDH-mut group for both MET (p=0.034) and CHO (p=0.01). However, there was no significant difference in the ratio for FDG.

CONCLUSIONS

PET imaging using MET, CHO, and FDG was confirmed to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.

A surgical navigation system for aortic vascular surgery: a practical approach

In aortic vascular surgery, a navigation system must represent the anatomical map of individual patient in order to detect the important artery. To provide a proper fit for positions along the dorsoventral axis, the spinous process was added to a currently used anatomical point set consisting of four anterior body landmarks. In addition, we attempted to reduce the registration error by compensating for alignment errors resulting from variations in tissue thickness at each landmark. The alignment values were examined using a human phantom consisting of a skeleton model with subcutaneous tissue in the semilateral position. Using this method, a phantom simulation and five clinical trials were performed. Target errors were evaluated at the orifice of the intercostal artery. In the phantom simulation, the error at the target point was 4.1 ± 2.7 mm. However, for one patient undergoing thoracoabdominal aortic aneurysm replacement surgery, the target error was 8.0 mm using the proposed method.

Fully automatic rapid DNA Ploidy Analyzer for intraoperative rapid diagnosis support

Frozen section studies are a useful method to rapidly define tumor malignancy and identify the extent of surgical resection. However, diagnosis with a frozen section is qualitative and sometimes difficult. Therefore a quantitative method for grading tumors is desired. We have already reported a technique of intraoperative flow cytometry (iFC) that supports intraoperative histopathological examination of frozen sections. In this study, we report an advanced system named "Fully Automatic Rapid DNA Ploidy Analyzer" with a tissue pretreatment function and a freeze-dried reagent kit for cell staining. To evaluate our system, we analyzed samples from glioma patients who underwent open surgery for brain tumors. We observed obvious difference of the Malignancy Index (MI) between neoplastic and perilesional brain tissue (26.0 ±22.1% and 4.1 ±2.5%, respectively, P<0.001). Cut-off level for identification of the tumor in the biopsy specimen was 6.8% which provided 86% sensitivity and 81% specificity. We also obtained a good correlation between the MI and histological grade (WHO grading). Our new system also enabled finishing the process from sample preparation to the end of analysis in ten minutes or less. These results demonstrate that our fully automatic rapid DNA ploidy analyzer is feasible for rapid determination of glioma presence in a surgical biopsy sample.

11C-methionine uptake correlates with combined 1p and 19q loss of heterozygosity in oligodendroglial tumors

BACKGROUND AND PURPOSE

Oligodendroglial tumors with 1p/19q LOH are known to show longer patient survival than those without 1p/19q LOH, but the reason for this clinical difference has not been elucidated, to our knowledge. This study was designed to clarify whether uptake of MET correlates with 1p/19q LOH of oligodendroglial tumors.

MATERIALS AND METHODS

This study included 102 consecutive patients with supratentorial WHO grade II and III oligodendroglial tumors (39 oligoastrocytic and 63 oligodendroglial tumors) that were resected and diagnosed between January 2008 and August 2011 at Tokyo Women's Medical University Hospital. These patients underwent MET PET T/N ratio measurement before treatment. T/N ratios were calculated by dividing the maximum SUV for the tumor by the mean SUV of the contralateral normal frontal cortex. After surgery, FISH for resected tissues was used to determine 1p/19q LOH.

RESULTS

The mean T/N ratio of tumors with 1p/19q LOH was significantly greater than that of tumors without 1p/19q LOH (P = .0166). The threshold T/N ratio value of 2.46 was found to correlate significantly with 1p/19q LOH by univariate (P = .0011) and multivariate analyses (P = .0209) in all tumors.

CONCLUSIONS

The T/N ratio on MET PET might be a useful aid to the diagnosis of 1p/19q LOH. Our data add new information on the biology and imaging characteristics of oligodendroglial tumors with 1p/19q LOH.

"Donut's shape" radiosurgical treatment planning for large cystic metastatic brain tumors

BACKGROUND

Radiosurgical management of large cystic metastatic brain tumors represents a significant challenge. Nevertheless, modified dose planning has shown beneficial results in such cases.

METHOD AND RESULTS

"Donut's shape" radiosurgical treatment planning is based on the chain-like application of multiple, small-sized isocenters for selective coverage of the contrast-enhancing tumor capsule and minimal irradiation of the central cystic area. Such an approach was used for the management of large cystic intracranial metastases, which were not accompanied by a significant mass effect and did not require immediate volume reduction. Treatment was done using Leksell Gamma Knife model C with automatic positioning system. The majority of treated lesions showed significant shrinkage after radiosurgery and no major complications were met.

CONCLUSION

Large cystic metastatic brain tumors may be successfully treated with gamma knife radiosurgery alone using the proposed "donut's shape" dose planning with coverage of the contrast-enhancing tumor capsule by multiple small-sized isocenters.

Risk factors for regrowth of intracranial meningiomas after gamma knife radiosurgery: importance of the histopathological grade and MIB-1 index

INTRODUCTION

The influence of histopathological grade and MIB-1 index of intracranial meningioma on the results of its radiosurgical management is not clear. The objective of the present retrospective study was to make an evaluation of these factors along with an analysis of other variables associated with progression-free survival after gamma knife radiosurgery (GKR).

PATIENTS AND METHODS

Thirty-four intracranial meningiomas with known detailed histopathological diagnosis were analyzed. Tumors of WHO histopathological grades I, II, and III were diagnosed in 24, 3, and 7 cases, respectively. The median MIB-1 index was 1.3% (range: 0-31.9%). In 14 cases the MIB-1 index was 3.0% and more. In 26 cases the treatment was done at the time of tumor recurrence. Median volume of the neoplasm at the time of GKR was 4.1 mL (range: 0.4-43.1 mL). Median marginal dose was 12 Gy (range: 8-19 Gy). Median length of follow-up constituted 63 months (range: 19-132 months).

RESULTS

Actuarial progression-free survival at 1, 3, 5, and 10 years constituted 100, 94, 83, and 58%, respectively. Histopathological grade II or III (p<0.0001), MIB-1 index 3% and more (p=0.0004), and non-skull base location (p=0.0026) of the tumor showed negative associations with progression-free survival in multivariate analyses. Actuarial progression-free survival at 5 years after GKR for benign and non-benign meningiomas constituted 100 and 45%, respectively (p<0.0001).

CONCLUSION

Radiosurgery is a highly effective management option for benign intracranial meningiomas, but growth control of non-benign ones is significantly worse. It requires close neuroradiological follow-up and necessitates the search for modified treatment strategies.

Expression and prognostic significance of differentiation markers in primary CNS lymphoma (PCNSL)

e13028

Background: BCL-6 expression has been reported to be associated with a better prognosis in PCNSL. However, significant differences of B-cell lymphoma subtypes exist in different geographic regions. The objectives of this study were to characterize the immunophenotypes of PCNSL in Japan and to determine their utility in predicting clinical outcomes. Methods: Immunostaining for CD5, CD10, BCL-6, and MUM-1 was done to determine the profile of diffuse large B-cell lymphoma of PCNSL from 27 immunocompetent patients in Japan. Then, the authors evaluated whether clinical and immunophenotypic markers were associated with progression-free or overall survival. Results: Germinal center B-cell (GCB) marker CD10 was positive in 22% of PCNSL samples, while another GCB marker BCL-6 was positive in 48% of samples. Post-GCB marker MUM-1 was positive in 81% of samples. Poor prognostic marker of systemic B-cell lymphoma CD5 was expressed in 15% of samples. In univariate analyses, only BCL-6 expression had a significant effect on progression-free survival (median, 6.1 months in BCL-6-positive patients versus 15.6 months in BCL-6-negative patients; p = 0.037). Patients with BCL-6 expression had a trend towards longer overall survival but nonsignificant. GCB subgroup (CD10-positive or CD10-negative/BCL-6-positive/MUM-1-negative) was not significantly associated with favorable survival. Conclusions: BCL-6 expression is associated with a poor prognosis in patients with PCNSL. The discrepancy between the reports from other groups and our results is potentially due to the racial, geographic or immunophenotypic differences of PCNSL.

No significant financial relationships to disclose.

Dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain tissue after stereotactic radiosurgery: a serial proton magnetic resonance spectroscopy study

The present study evaluated the dynamics of metabolic changes in intracranial metastases and distant normal-appearing brain after stereotactic radiosurgery (SRS). Forty neoplasms were evaluated with single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) both before and after treatment. From one to six examinations (median, 3) were done in each individual case during follow-up. At the time of each investigation additional (1)H-MRS was obtained from the normal-appearing brain distant from the radiosurgical target. Investigated metabolites included N-acetylaspartate (NAA), choline-containing compounds (Cho), creatine (Cr), and mobile lipids (Lip). Within the first month after SRS responded tumors showed a statistically significant increase in NAA/Cho ratio, and decrease of Cho content and Lip-to-normal brain Cr (nCr) ratio. By contrast, statistically significant metabolic alterations were not detected in stabilized tumors. Statistically significant volumetric and metabolic changes were not marked between three and 12 months after treatment in non-progressing lesions. Alternatively, decrease of NAA/Cho ratio, NAA content and Cr content, and increase in Lip/nCr ratio and Cho content were evident in progressive neoplasms, and subtle metabolic alterations could be revealed even before the increase in the lesion volume. Metabolic characteristics of normal-appearing brain distant from the radiosurgical target did not show statistically significant changes within the first year after treatment. In conclusion, additional use of serial (1)H-MRS during follow-up after SRS for intracranial metastases permits detailed evaluation of the metabolic tumor response and may be potentially helpful for early prediction of recurrence.

Development of an articulating ultrasonically activated device for laparoscopic surgery

BACKGROUND

Ultrasonically activated devices (USADs) offer excellent coagulating dissection performance and are broadly used, particularly in endoscopic operations. Traditional USADs, however, have fixed linear shape and are thus limited in the directions from which organs can be approached. We have developed a small USAD transducer attached to the tip of an articulating device, offering a new kind of USAD in which the tip can bend as desired. We describe herein an evaluation of the coagulating dissection performance of this new articulating USAD and an in vivo confirmation of clinical usefulness.

METHODS

To evaluate coagulating dissection performance, we compared coagulating shearing on porcine splenic arteries between the articulating USAD and a Harmonic Scalpel II (HSII), representing a traditional USAD. Changing the amplitude of vibration between 60 microm and 80 microm and grip force among 1, 2, and 3 N, we measured the time required for division and bursting pressure of coagulating dissection. An in vivo experiment in a pig was also used to confirm the usefulness of the articulating USAD in laparoscopic operations.

RESULTS

Division time did not differ significantly between the articulating USAD and HSII with an 80-microm amplitude of vibration and a grip force of 2 or 3 N. Bursting pressure of blood vessels showed no significant difference between articulating USAD and HSII under all experimental conditions. In the in vivo experiment, the new bendable tip of the articulating USAD displayed coagulating dissection performance equivalent to that of the traditional USAD.

CONCLUSIONS

We have developed a new articulating USAD that can broaden the range of methods and approaches available for USADs and improve usefulness and safety.

Intraoperative MRI for Brain Tumor Resection

Computer aided neurosurgery is now a highly advanced and essential technique, especially for the gliomas in the vicinity to the eloquent areas or deep inside of the brain. The intraoperative MRI (iMRI) is an important tool for the computer navigation system, considering brain shift under craniotomy. Real time navigation by the iMRI with brain mapping by subcortical stimulation and verbal confirmation by awake craniotomy can lead to the safe and precise tumor resection. The usefulness of an intraoperative low-field open MRI is defined for neuronavigation, especially for demonstration of the pyramidal tract in relation to the precise tumor location, considering brain shift during the operative procedure, to avoid tract injury.

Analysis of 11C-methionine uptake in low-grade gliomas and correlation with proliferative activity

BACKGROUND AND PURPOSE

The relationship of (11)C-methionine (MET) uptake and tumor activity in low-grade gliomas (those meeting the criteria for World Health Organization [WHO] grade II gliomas) remains uncertain. The aim of this study was to compare MET uptake in low-grade gliomas and to analyze whether MET positron-emission tomography (PET) can estimate tumor viability and provide evidence of malignant transformation.

MATERIALS AND METHODS

We studied glioma metabolic activity in 49 consecutive patients with newly diagnosed grade II gliomas by using MET PET before surgical resection. On MET PET, we measured tumor/normal brain uptake ratio (T/N ratio) in 21 diffuse astrocytomas (DAs), 12 oligodendrogliomas (ODs), and 16 oligoastrocytomas (OAs). We compared MET T/N ratio among these 3 tumors and investigated possible correlation with proliferative activity, as measured by Mib-1 labeling index (LI).

RESULTS

MET T/N ratios of DA, OD, and OA were 2.11 +/- 0.87, 3.75 +/- 1.43, and 2.76 +/- 1.27, respectively. The MET T/N ratio of OD was significantly higher than that of DA (P < .005). In comparison of MET T/N ratios with the Mib-1 LI, a significant correlation was shown in DA (r = 0.63; P < .005) but not in OD and OA.

CONCLUSION

MET uptake in DAs may be closely associated with tumor viability, which depends on increased amino acid transport by an activated carrier-mediated system. DAs with lower MET uptake were considered more quiescent lesions, whereas DA with higher MET uptake may act more aggressively.

Differentiation of High-Grade and Low-Grade Gliomas Using Pattern Analysis of Long-Echo Single-Voxel Proton Magnetic Resonance Spectroscopy ((1)H-MRS)

The usefulness of proton magnetic resonance spectroscopy ((1)H-MRS) for glioma grading is not clear, particularly due to the absence of standard criteria for data analysis. Previously we had developed an original classification of the pathological (1)H-MRS spectra based on the identification of the predominant metabolite peak, N-acetylaspartate (NAA) for Type I, choline-containing compounds (Cho) for Type II, and mobile lipids (Lip) for Type III, and presence or absence of other metabolite peaks: lactate (Lac), Lip, or Cho. The present study evaluated the effectiveness of this classification in grading of previously non-treated gliomas. A total of 38 low-grade and 33 high-grade neoplasms were investigated. Four tumors had (1)H-MRS spectra Type I, and all of those were low-grade. Three tumors had (1)H-MRS spectra Type III, and all those were glioblastomas. Fifteen tumors with (1)H-MRS spectra Type II had a Lip/NAA ratio more than 1 (Type II C with moderate elevation of lipids), and 12 of those neoplasms were high-grade. The differences in distribution of high-grade and low-grade gliomas among another 49 gliomas with (1)H-MRS spectra Type II did not depend on the presence of Lac and/or Lip peaks, and in this subgroup NAA/Cho ratio was also evaluated. Inclusion of both characteristics (type of the (1)H-MRS spectrum and NAA/Cho ratio with defined cut-off level of 0.6) into the diagnostic algorithm yielded 72% diagnostic accuracy (95% confidence interval: 62%-82%) in discriminating high-grade and low-grade neoplasms. In conclusion, pattern analysis of the pathological (1)H-MRS spectra using the proposed classification along with evaluation of NAA/Cho ratio might be helpful for non-invasive glioma grading.

Metabolic assessment of gliomas using 11C-methionine, [18F] fluorodeoxyglucose, and 11C-choline positron-emission tomography

BACKGROUND AND PURPOSE

Positron-emission tomography (PET) is a useful tool in oncology. The aim of this study was to assess the metabolic activity of gliomas using (11)C-methionine (MET), [(18)F] fluorodeoxyglucose (FDG), and (11)C-choline (CHO) PET and to explore the correlation between the metabolic activity and histopathologic features.

MATERIALS AND METHODS

PET examinations were performed for 95 primary gliomas (37 grade II, 37 grade III, and 21 grade IV). We measured the tumor/normal brain uptake ratio (T/N ratio) on each PET and investigated the correlations among the tracer uptake, tumor grade, tumor type, and tumor proliferation activity. In addition, we compared the ease of visual evaluation for tumor detection.

RESULTS

All 3 of the tracers showed positive correlations with astrocytic tumor (AT) grades (II/IV and III/IV). The MET T/N ratio of oligodendroglial tumors (OTs) was significantly higher than that of ATs of the same grade. The CHO T/N ratio showed a significant positive correlation with histopathologic grade in OTs. Tumor grade and type influenced MET uptake only. MET T/N ratios of more than 2.0 were seen in 87% of all of the gliomas. All of the tracers showed significantly positive correlations with Mib-1 labeling index in ATs but not in OTs and oligoastrocytic tumors.

CONCLUSION

MET PET appears to be useful in evaluating grade, type, and proliferative activity of ATs. CHO PET may be useful in evaluating the potential malignancy of OTs. In terms of visual evaluation of tumor localization, MET PET is superior to FDG and CHO PET in all of the gliomas, due to its straightforward detection of "hot lesions".

Metabolic characteristics of intracranial metastases, detected by single-voxel proton magnetic resonance spectroscopy, are seemingly not predictive for tumor response to gamma knife radiosurgery

Metabolic characteristics of intracranial metastases, detected with proton magnetic resonance spectroscopy (1H-MRS) have known associations with clinical predictors of tumor response to radiosurgery. Therefore, it can be suspected that the metabolic profile of the neoplasm by itself might have some prognostic significance for the outcome after irradiation. Twenty-six intracranial metastases, which underwent metabolic evaluation with single-voxel 1H-MRS before gamma knife radiosurgery (GKR) and were followed for at least 3 months after treatment, were selected for retrospective analysis. The tumors most frequently originated from the lungs (9 cases), breast (7 cases), colon and rectum (5 cases). The average volume of the investigated intracranial neoplasm was 5.4+/-2.0 mL. The average marginal irradiation dose was 18.6+/-2.3 Gy. The mean follow-up after GKR constituted 8.0+/-5.5 months. Tumor response to GKR was identified in 13 cases on average 2.2+/-1.8 months after treatment. Local recurrence was marked in 10 cases on average 8.7+/-4.1 months after treatment. None of the investigated 1H-MRS metabolic parameters of intracranial metastases showed a statistically significant association with the outcome after GKR. The negative results of the present study make doubtful the predictive value of metabolic characteristics of intracranial metastases, detected with single-voxel 1H-MRS, for the outcome after radiosurgery.

Usefulness of intraoperative magnetic resonance imaging for glioma surgery

BACKGROUND

Radical resection of gliomas can increase patient's survival. There is known concern, however, that aggressive tumour removal can result in neurological morbidity. The objective of the present study was to evaluate the usefulness of low magnetic field strength (0.3 Tesla) open intraoperative magnetic resonance imaging (iMRI) for complete resection of glioma with emphasis on functional outcome.

METHODS

From 2000 to 2004, 96 patients with intracranial gliomas underwent tumour resection with the use of iMRI in Tokyo Women's Medical University. There were 50 men and 46 women; mean age was 39 years. Tumour volume varied from 1.2 ml to 198 ml (median: 36.5 mL). Resection rate and postoperative neurological status were compared between control group (46 cases, operated on during the initial period after installation of iMRI), and study group (50 most recent cases, in whom surgery was done using established treatment algorithm and improved image quality).

FINDINGS

Overall, mean resection rate was 93%, and medial residual tumour volume was 0.17 ml. Total tumour removal was achieved in 44 cases (46%). Compared to control group, resection rate in the study group was significantly higher (91%, vs. 95%; P < 0.05), whereas residual tumour volume was significantly smaller (1.7 mL vs. 0.025 mL; P < 0.001). Nine patients in the control group (20%) and 24 in the study group (48%) experienced temporary postoperative neurological deterioration (P < 0.01), however, the rate of permanent morbidity evaluated 3 months after surgery did not differ significantly between the groups investigated (13% vs. 14%).

CONCLUSIONS

Use of iMRI during surgery for intracranial gliomas permits to attain aggressive tumour resection with good functional outcome. Nevertheless, surgical experience with the iMRI system, establishment of treatment algorithm, and improvement of image quality are of paramount importance for optimal results.

Direct maxacalcitol injection into hyperplastic parathyroids improves skeletal changes in secondary hyperparathyroidism

Direct maxacalcitol (OCT) injection into a parathyroid gland (PTG) ameliorates several important etiologic factors of resistance to medical treatments for secondary hyperparathyroidism (s-HPT): the upregulations of vitamin D receptor (VDR) and Ca-sensing receptor (CaSR) in PTGs and the regression of PTG hyperplasia by the induction of apoptosis. In this study, we evaluated the bone histomorphology on the basis of maintaining these effects in advanced s-HPT. Five/six nephrectomized Sprague-Dawley rats were fed a high-phosphorus and low-calcium diet for 8 weeks. These rats were divided into four treatment groups: (1) basic uremic (at the baseline), (2) direct OCT single injection into PTGs (DI-OCT) followed by OCT intravenous administration for 4 weeks (IV-OCT), (3) direct vehicle injection and IV-OCT, and (4) no treatment for an additional 4 weeks. The effects of these treatments on serum intact-parathyroid hormone (PTH) level, PTG weight, VDR and CaSR expression levels in PTGs, and bone histomorphometric parameters were investigated. In the DI-OCT+IV-OCT group, the significant decrease in serum intact-PTH level was maintained by the following IV-OCT. A significant decrease in PTG weight and the upregulations of VDR and CaSR expression levels in PTGs were also observed. Bone histomorphometric analysis showed significant improvements in osteitis fibrosa in both cancellous and cortical bones. However, these findings were not observed in the other groups. These results suggest that osteitis fibrosa caused by advanced s-HPT can be successfully reversed by a control of PTH at an appropriate level through the improvement of PTG hyperplasia as induced by DI-OCT+IV-OCT.

Malignant Progression of Benign Brain Tumors after Gamma Knife Radiosurgery: Is it Really Caused by Irradiation?

Malignant transformation of benign neoplasm after radiosurgery is usually diagnosed based on the initial presence of benign tumor, its exposure to ionizing radiation, elapsed time from radiation exposure to malignant progression, and different histological characteristics or growth rate of the regrowing tumor comparing with those originally treated. Three presented cases fulfilled these diagnostic criteria; however, it seems that progression of the tumors (schwannoma, meningioma, chordoma) resulted from the natural course of the disease, rather than represented side effects of gamma knife radiosurgery. Evaluation of the proliferative potential of the benign neoplasm before radiosurgical treatment either directly, if tumor sampling is available, or indirectly, by calculation of the tumor growth rate and/or analysis of the data of the metabolic imaging (PET, MRS) is important for identification of "aggressive" subtypes, precise prediction of prognosis, and confirmation of the radiation-induced malignant transformation in cases of tumor regrowth.

Differentiation of the Radiation-Induced Necrosis and Tumor Recurrence after Gamma Knife Radiosurgery for Brain Metastases: Importance of Multi-Voxel Proton MRS

Comparative analysis of the diagnostic accuracy of FDG PET, single-voxel, and multi-voxel proton MRS for differentiation between radiation-induced necrosis and tumor recurrence was done in 9 patients with brain metastases treated by gamma knife radiosurgery. In all cases enlargement of the lesion and increase of the perilesional edema were demonstrated by MRI on average 10.6+/-2.6 months after initial treatment. Radiation-induced necrosis was identified in 5 patients (histologically in 2, clinically in 3). In one of these a false positive result of FDG PET was observed, whereas data of proton MRS were always correct. The diagnosis of tumor recurrence was established in 4 patients (histologically in 3, clinically in 1). Among these both FDG PET and single-voxel proton MRS showed false negative results (each method twice), whereas multi-voxel proton MRS always permitted us to establish the correct diagnosis. The present study demonstrates the higher diagnostic accuracy of multi-voxel proton MRS, in comparison with single-voxel proton MRS and FDG PET, for the differentiation of the radiation-induced necrosis and tumor recurrence. Its use is especially important in mixed lesions with co-existence of both post-irradiation changes and viable neoplasm. Monitoring of the treatment response by serial multi-voxel proton MRS seems to be reasonable during follow-up of patients with brain metastases after radiosurgery.

Keloid-derived fibroblasts show increased secretion of factors involved in collagen turnover and depend on matrix metalloproteinase for migration

BACKGROUND

A keloid is a specific skin lesion that expands beyond the boundaries of the original injury as it heals. Histologically, it is characterized by the excessive accumulation of collagen. However, the reasons for the expansion and the invasive nature of keloids remain unknown.

OBJECTIVES

We evaluated collagen degradation and migration by cultured keloid fibroblasts based on the assumption that these variables were of functional relevance to the expanding and invasive nature of keloid lesions.

METHODS

Collagen production was investigated by the detection of type 1 collagen (procollagen type 1C peptide: P1P). Matrix metalloproteinase (MMP)-1 (interstitial collagenase) and MMP-2 (gelatinase-A), were investigated as elements of the collagen degradation system. Enzyme immunoassays were performed to measure the production of P1P, MMP-1, MMP-2, and tissue inhibitor of metalloproteinase (TIMP)-1. To assess the production of MMP-2 its gelatinolytic activity was measured by zymography using gelatin-containing gels. The participation of transforming growth factor-beta1 (TGF-beta1) in the production and degradation of collagen was also investigated. Finally, the migratory activity of keloid fibroblasts was evaluated using a colony dispersion assay.

RESULTS

The production of type 1 collagen, MMP-1, MMP-2, and TIMP-1 by keloid fibroblasts was 3-fold, 6-fold, 2.4-fold, and 2-fold greater than that of normal dermal fibroblasts, respectively. Production of P1P was increased when TGF-beta1 was added to cultures of keloid fibroblasts, while it was decreased when anti-TGF-beta1 antibody was added to the cultures. In contrast, the production of MMP-1 was decreased by the addition of TGF-beta1 to cultured keloid fibroblasts, while it was increased when anti-TGF-beta1 antibody was added to the cultures. The production of MMP-2 increased after treatment with TGF-beta1, but did not change significantly when anti-TGF-beta1 antibody was added to the cultures. Production of TIMP-1 did not change significantly when either TGF-beta1 or anti-TGF-beta1 antibody was added to the cultures. Keloid fibroblasts showed a 2.5-fold increase of migratory activity compared with normal dermal fibroblasts, while the migratory activity of these fibroblasts was reduced to the control level by treatment with a broad-spectrum MMP inhibitor (GM 6001).

CONCLUSIONS

Cultured keloid fibroblasts showed increased production of collagen and MMPs, and TGF-beta1 played a role in this regulation of production. In addition, increased production of MMPs had a role in the high migratory activity of cultured keloid fibroblasts.

Minimally invasive management of the third ventricle glioma in a patient without hydrocephalus: neurofiberscopic biopsy followed by gamma knife radiosurgery

There is usually concern that ventricular enlargement is necessary for safe neuroendoscopic procedures. However, newly developed models of neurofiberscopes with a small outer diameter can be effectively used even in patients without ventriculomegaly. We present the case of a successful neurofiberscopic biopsy of a third ventricle anaplastic astrocytoma in a previously shunted patient without hydrocephalus. Subsequent gamma knife radiosurgery led to complete disappearance of the tumor. It seems that presence of collapsed ventricles, and even symptoms consistent with the slit ventricle syndrome, should not be considered as contraindications for neurofiberscopic surgery when brain compliance is sufficiently preserved. The latter should be considered as the key point of safe endoscopic manipulations. The combination of the neuroendoscopy and stereotactic radiosurgery provides wide possibilities for minimally invasive management of selected intracranial tumors.

New possibilities for stereotaxis. Information-guided stereotaxis

Information-guided stereotaxis, assisted by visualization of medical information, will become the next generation of neurosurgical systems. We performed 76 open MRI surgeries at Tokyo Women's Medical University between March 3, 2000 and April 12, 2001. Of them, comparisons of pre- and post-operative MR images for malignant gliomas in 21 cases revealed an average resection rate of 90.3% (the maximum 100%, the minimum 55%). In this article we describe real time updated navigation, augmented reality navigation, three-dimensional navigation, chemical navigation, information-guided navigation system (High definition visual Computer Aided Surgery System: HivisCAS), and open MRI-guided surgery that we are developing.

Decreased type III and V collagen expression in chorionic villi of hydatidiform mole

To investigate the characteristic structure of hydatidiform mole, various types of collagen expression were determined in human villous tissues obtained from normal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirect immunofluorescent staining was performed to detect type I, III, and VI collagen with specific monoclonal antibodies. Collagens were also extracted from the villous tissues obtained from normal pregnancy and hydatidiform mole by the salt precipitation method. Immunohistochemical staining for type I, III, and VI collagen revealed weak staining of the villous stroma in hydatidiform mole compared with that in normal pregnancy. Both the ratios of type III to type I collagen and the ratios of type V to type I collagen in the villous tissues were significantly decreased (P < 0.05) in molar pregnancy compared with those in normal pregnancy. These results suggest that alterations in the distribution and composition of collagen might play an important role in determining the pathophysiology and structure of hydatidiform mole.

Overexpression of type IV collagen in chorionic villi in hydatidiform mole

To investigate the characteristic structure of hydatidiform mole, type IV collagen expression was determined in human villous tissues obtained from normal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirect immunofluorescent staining was performed to detect type IV collagen with specific monoclonal antibody, and Northern blot analysis was performed to assess expression of messenger ribonucleic acid for the alpha1(IV) chain. In addition, serum levels of type I, III, and IV collagen were measured by RIA. Immunohistochemical staining for type IV collagen revealed stronger staining of the trophoblastic basement membrane in hydatidiform mole than in normal pregnancy. Northern blot analysis revealed that the villous expression of messenger ribonucleic acid for the alpha1(IV) chain was significantly increased in hydatidiform moles compared with normal pregnancy (P < 0.01). Although there were no differences in the serum type I and III collagen levels between hydatidiform mole and normal pregnancy, the type IV collagen level was significantly higher in patients with hydatidiform mole than in normal pregnancy (P < 0.05). These results suggest that type IV collagen might play an important role in determining the pathophysiology and structure of hydatidiform mole.

Type VI collagen expression during growth of human ovarian follicles

OBJECTIVE

To identify type VI collagen expression in human ovarian follicles during follicular growth.

DESIGN

In vitro experiment.

SETTING

Department of Obstetrics and Gynecology, Wakayama Medical College, Japan.

PATIENT(S)

Regularly cycling women who underwent adnexectomy.

INTERVENTION(S)

Immunohistochemistry and in situ hybridization for human type VI collagen.

MAIN OUTCOME MEASURE(S)

Expression of type VI collagen.

RESULT(S)

Expression of type VI collagen was observed in the theca cell layers during folliculogenesis, whereas no expression of type VI collagen was observed in the granulosa cell layers at the mRNA and protein levels. As the follicles grew, immunostaining for type VI collagen became intense in the theca cell layers, especially the theca externa. In preovulatory follicles, however, weak, fragmented, or discontinuous immunostaining of the theca cell layers was observed. This fragmented or discontinuous immunostaining was evident predominantly in the apical area of preovulatory follicles rather than in the basal area.

CONCLUSION(S)

Type VI collagen is present in the theca cell layers of follicles during folliculogenesis and plays an important role in interactions between the theca cells and extracellular matrix. These interactions may lead to changes in the shape, proliferation, migration, or differentiation of follicular cells during follicular development, maturation, and ovulation.