Radiotherapy concepts for spinal metastases-results from an online survey among radiation oncologists of the German Society for Radiation Oncology.

PURPOSE: Spinal metastases (SM) are a common radiotherapy (RT) indication. There is limited level I data to drive decision making regarding dose regimen (DR) and target volume definition (TVD). We aim to depict the patterns of care for RT of SM among German Society for Radiation Oncology (DEGRO) members. METHODS: An online survey on conventional RT and Stereotactic Body Radiation Therapy (SBRT) for SM, distributed via e­mail to all DEGRO members, was completed by 80 radiation oncologists between February 24 and April 29, 2022. Participation was voluntary and anonymous. RESULTS: A variety of DR was frequently used for conventional RT (primary: n = 15, adjuvant: n = 14). 30 Gy/10 fractions was reported most frequently. TVD in adjuvant RT was heterogenous, with a trend towards larger volumes. SBRT was offered in 65% (primary) and 21% (adjuvant) of participants' institutions. A variety of DR was reported (primary: n = 40, adjuvant: n = 27), most commonly 27 Gy/3 fractions and 30 Gy/5 fractions. 59% followed International Consensus Guidelines (ICG) for TVD. CONCLUSION: We provide a representative depiction of RT practice for SM among DEGRO members. DR and TVD are heterogeneous. SBRT is not comprehensively practiced, especially in the adjuvant setting. Further research is needed to provide a solid data basis for detailed recommendations.

CD13 expression affects glioma patient survival and influences key functions of human glioblastoma cell lines in vitro.

CD13 (APN) is an Alanyl-Aminopeptidase with diverse functions. The role of CD13 for gliomas is still unknown. In this study, data of glioma patients obtained by TCGA and CGGA databases were used to evaluate the survival rate and prognostic value of CD13 expression level. Protein expression of CD13 was confirmed by immunofluorescence staining of fresh patient tissues. Eight human glioblastoma cell lines were studied by RT-PCR, Western Blot, immunofluorescence staining and flow cytometry to define CD13 expression. Cell lines with different CD13 expression status were treated with a CD13 inhibitor, bestatin, and examined by MTT, scratch and colony formation assaysas well as by apoptosis assay and Western Blots. Bioinformatics analysis indicated that patients with high expression of CD13 had poor survival and prognosis. Additionally, CD13 protein expression was positively associated with clinical malignant characteristics. Investigated glioblastoma cell lines showed distinct expression levels and subcellular localization of CD13 with intracellular enrichment. Bestatin treatment reduced proliferation, migration and colony formation of glioma cells in a CD13-dependent manner while apoptosis was increased. In summary, CD13 has an impact on glioma patient survival and is important for the main function of specific glioma cells.

Metastases to the pituitary gland: insights from the German pituitary tumor registry.

Metastatic involvement of the pituitary gland is a rare but clinically significant phenomenon, that often poses diagnostic and therapeutic challenges. The aim of this study was to provide a comprehensive analysis of the origin of pituitary metastases using data from the German Pituitary Tumor Registry, one of the globally largest collections of pituitary pathology specimens. Here, we report data from a retrospective analysis of patients with metastases to the pituitary registered between 1990 and 2022. Out of 17,896 pituitary cases in the registry during this period, a total of 96 metastases to the pituitary gland were identified, accounting for 0.5% of all pituitary tumors in the registry. The mean age of the patients was 64 years. Breast cancer was identified as the primary tumor in 25% of total cases (n = 24/96) and in 50% of female patients. The second most prevalent primary tumor was lung cancer (18.75%, n = 18/96), followed by renal cell carcinoma (14.58%, n = 14/96). In comparison to current meta-analyses, this cohort shows a higher prevalence of metastases originating from the kidney. Furthermore, in contrast to the existing literature, no case of primary thyroid tumor was identified. Our study highlights the importance of pituitary metastases as a differential diagnosis in patients presenting with pituitary tumors.

Personalized surgical informed consent with stereoscopic visualization in neurosurgery-real benefit for the patient or unnecessary gimmick?

BACKGROUND: Informed consent of the patient prior to surgical procedures is obligatory. A good and informative communication improves patients' understanding and confidence, thus may strengthen the patient-doctor relationship. The aim of our study was to investigate the usefulness of additional stereoscopic visualization of patient-specific imaging during informed consent conversation. METHODS: Patients scheduled for a brain tumor surgery were screened for this study prospectively. The primary exclusion criteria were cognitive or visual impairments. The participants were randomized into two groups. The first group underwent a conventional surgical informed consent performed by a neurosurgeon including a demonstration of the individual MRI on a 2D computer screen. The second group received an additional stereoscopic visualization of the same imaging to explain the pathology more in-depth. The patients were then asked to fill in a questionnaire after each part. This questionnaire was designed to assess the potential information gained from the patients with details on the anatomical location of the tumor as well as the surgical procedure and possible complications. Patients' subjective impression about the informed consent was assessed using a 5-point Likert scale. RESULTS: A total of 27 patients were included in this study. After additional stereoscopic visualization, no significant increase in patient understanding was found for either objective criteria or subjective assessment. Participants' anxiety was not increased by stereoscopic visualization. Overall, patients perceived stereoscopic imaging as helpful from a subjective perspective. Confidence in the department was high in both groups. CONCLUSION: Stereoscopic visualization of MRI images within informed consent conversation did not improve the objective understanding of the patients in our series. Although no objective anatomical knowledge gain was noted in this series, patients felt that the addition of stereoscopic visualization improved their overall understanding. It therefore potentially increases patient confidence in treatment decisions.

Microglia/macrophages express alternative proangiogenic factors depending on granulocyte content in human glioblastoma.

Myeloid cells are an inherent part of the microenvironment of glioblastoma multiforme (GBM). There is growing evidence for their participation in mechanisms of tumor escape, especially in the development of resistance following initially promising anti-VEGF/VEGFR treatment. Thus, we sought to define the capability of myeloid cells to contribute to the expression of proangiogenic molecules in human GBM. We investigated GBM specimens in comparison with anaplastic astrocytoma (WHO grade III) and epilepsy patient samples freshly obtained from surgery. Flow cytometric analyses revealed two distinct CD11b+ CD45+ cell populations in GBM tissues, which were identified as microglia/macrophages and granulocytes. Due to varied granulocyte influx, GBM samples were subdivided into groups with low (GBM-lPMNL) and high (GBM-hPMNL) numbers of granulocytes (polymorphonuclear leukocytes; PMNL), which were related to activation of the microglia/macrophage population. Microglia/macrophages of the GBM-lPMNL group were similar to those of astrocytoma specimens, but those of GBM-hPMNL tissues revealed an altered phenotype by expressing high levels of CD163, TIE2, HIF1α, VEGF, CXCL2 and CD13. Although microglia/macrophages represented the main source of alternative proangiogenic factors, additionally granulocytes participated by production of IL8 and CD13. Moreover, microglia/macrophages of the GBM-hPMNL specimens were highly associated with tumor blood vessels, accompanied by remodeling of the vascular structure. Our data emphasize that tumor-infiltrating myeloid cells might play a crucial role for limited efficacy of anti-angiogenic therapy bypassing VEGF-mediated pathways through expression of alternative proangiogenic factors. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clinical implementation of a 3D4K-exoscope (Orbeye) in microneurosurgery.

Exoscopic surgery promises alleviation of physical strain, improved intraoperative visualization and facilitation of the clinical workflow. In this prospective observational study, we investigate the clinical usability of a novel 3D4K-exoscope in routine neurosurgical interventions. Questionnaires on the use of the exoscope were carried out. Exemplary cases were additionally video-documented. All participating neurosurgeons (n = 10) received initial device training. Changing to a conventional microscope was possible at all times. A linear mixed model was used to analyse the impact of time on the switchover rate. For further analysis, we dichotomized the surgeons in a frequent (n = 1) and an infrequent (n = 9) user group. A one-sample Wilcoxon signed rank test was used to evaluate, if the number of surgeries differed between the two groups. Thirty-nine operations were included. No intraoperative complications occurred. In 69.2% of the procedures, the surgeon switched to the conventional microscope. While during the first half of the study the conversion rate was 90%, it decreased to 52.6% in the second half (p = 0.003). The number of interventions between the frequent and the infrequent user group differed significantly (p = 0.007). Main reasons for switching to ocular-based surgery were impaired hand-eye coordination and poor depth perception. The exoscope investigated in this study can be easily integrated in established neurosurgical workflows. Surgical ergonomics improved compared to standard microsurgical setups. Excellent image quality and precise control of the camera added to overall user satisfaction. For experienced surgeons, the incentive to switch from ocular-based to exoscopic surgery greatly varies.

The CXCL2/IL8/CXCR2 Pathway Is Relevant for Brain Tumor Malignancy and Endothelial Cell Function.

We aimed to evaluate the angiogenic capacity of CXCL2 and IL8 affecting human endothelial cells to clarify their potential role in glioblastoma (GBM) angiogenesis. Human GBM samples and controls were stained for proangiogenic factors. Survival curves and molecule correlations were obtained from the TCGA (The Cancer Genome Atlas) database. Moreover, proliferative, migratory and angiogenic activity of peripheral (HUVEC) and brain specific (HBMEC) primary human endothelial cells were investigated including blockage of CXCR2 signaling with SB225502. Gene expression analyses of angiogenic molecules from endothelial cells were performed. Overexpression of VEGF and CXCL2 was observed in GBM patients and associated with a survival disadvantage. Molecules of the VEGF pathway correlated but no relation for CXCR1/2 and CXCL2/IL8 was found. Interestingly, receptors of endothelial cells were not induced by addition of proangiogenic factors in vitro. Proliferation and migration of HUVEC were increased by VEGF, CXCL2 as well as IL8. Their sprouting was enhanced through VEGF and CXCL2, while IL8 showed no effect. In contrast, brain endothelial cells reacted to all proangiogenic molecules. Additionally, treatment with a CXCR2 antagonist led to reduced chemokinesis and sprouting of endothelial cells. We demonstrate the impact of CXCR2 signaling on endothelial cells supporting an impact of this pathway in angiogenesis of glioblastoma.

Wound healing complications after revascularization for moyamoya vasculopathy with reference to different skin incisions.

OBJECTIVEMoyamoya vasculopathy (MMV) is a steno-occlusive cerebrovascular disease that can be treated by a surgical revascularization. All the revascularization techniques influence the blood supply of the scalp, with a risk for wound healing disorders. The authors' aim was to analyze the wound healing process in the patients who underwent a direct or combined bypass surgery with a focus on different skin incisions.METHODSThe authors retrospectively identified all the patients with MMV who were treated surgically in their institution. Subsequently, they analyzed demographic data, clinical symptoms, surgical treatment, and detailed history of complications. Based on the evolution of their surgical techniques and the revascularization strategy to be used, the authors applied the following skin incisions: linear incision, curved incision, incomplete Y incision, and complete Y incision. Group comparisons regarding wound healing disorders were performed with significance testing using Fisher's exact test.RESULTSThe authors identified 172 patients with MMV (61.6% moyamoya disease, 7% unilateral moyamoya disease, 29.7% moyamoya syndrome, and 1.7% unilateral moyamoya syndrome), of whom 124 underwent bilateral operations. One-quarter of the patients were juveniles. A total of 236 hemispheres were included in the analysis, of which 27.9% were treated by a combined procedure with encephalomyosynangiosis. Overall, 5.1% major and 1.7% minor wound complications occurred. The overall wound complication rate was lower in direct revascularization compared to combined revascularization (3% vs 15.2%). The lowest incidence of wound healing disorders was found in the linear incision group for the parietal superficial temporal artery branch (1.6%), followed by the incomplete Y incision group for the frontal branch of the superficial temporal artery (3.8%) in the direct bypass group. In the combined revascularization cohort, major or minor wound disorders appeared in 14.3% and 4.8%, respectively, in the complete Y incision group and in 4.2% (for both major and minor) in the curved incision group. The complete Y incision caused significantly more wound healing disorders compared to the remaining incision types (17.1% vs 3.1%, p = 0.007).CONCLUSIONSWound healing disorders are one of the major complications of revascularization surgery. Their incidence depends on the revascularization strategy and skin incision applied, with a complete Y incision giving the worst results.

Impact of 68Ga-DOTATOC PET/MRI on robotic radiosurgery treatment planning in meningioma patients: first experiences in a single institution.

OBJECTIVEFor stereotactic radiosurgery (SRS) planning, precise contouring of tumor boundaries and organs at risk is of utmost importance. Correct interpretation of standard neuroimaging (i.e., CT and MRI) can be challenging after previous surgeries or in cases of skull base lesions with complex shapes. The aim of this study was to evaluate the impact of 68Ga-DOTATOC PET/MRI on treatment planning for image-guided SRS by CyberKnife.METHODSThe authors retrospectively identified 11 meningioma treatments in 10 patients who received a 68Ga-DOTATOC PET/MRI prior to SRS. The planning target volume (PTV) used for the patients' treatment was defined as the reference standard. This was contoured by a treating radiosurgeon (RS0) using fused planning CT and PET/MRI data sets. The same tumors were then contoured by another experienced radiosurgeon (RS1) and by a less-experienced radiosurgeon (RS2), both blinded to PET data sets. A comparison of target volumes with focus on volume-based metrics and distance to critical structures was performed. RS1 and RS2 also filled in a questionnaire analyzing the confidence level and the subjective need for the implementation of PET data sets for contouring.RESULTSAnalysis showed a subjective personal preference for PET/MRI in all cases for both radiosurgeons, particularly in proximity to critical structures. The analysis of the planning volumes per physician showed significantly smaller RS2-PTV in comparison to RS1-PTV and to RS0-PTV, whereas the median volumes were comparable between RS1-PTV and RS2-PTV (median: RS0: 4.3 cm3 [IQR 3.4-6.5 cm3] and RS1: 4.5 cm3 [IQR 2.7-6 cm3] vs RS2: 2.6 cm3 [IQR 2-5 cm3]; p = 0.003). This was also reflected in the best spatial congruency between the 2 experienced physicians (RS0 and RS1). The percentage of the left-out volume contoured by RS1 and RS2 compared to RS0 with PET/MRI demonstrated a relevant left-out-volume portion in both cases with greater extent for the less-experienced radiosurgeon (RS2) (RS1: 19.1% [IQR 8.5%-22%] vs RS2: 40.2% [IQR 34.2%-53%]). No significant differences were detected regarding investigated critical structures.CONCLUSIONSThis study demonstrated a relevant impact of PET/MRI on target volume delineation of meningiomas. The extent was highly dependent on the experience of the treating physician. This preliminary study supports the relevance of 68Ga-DOTATOC PET/MRI as a tool for radiosurgical treatment planning of meningiomas.

Pregnancy and delivery in moyamoya vasculopathy: experience of a single European institution.

Moyamoya vasculopathy (MMV) is a stenoocclusive cerebrovascular disease frequently affecting adolescent females. Thus, the management of pregnancy is of major interest for physicians dealing with MMV patients. However, clinical data concerning pregnant MMV patients is lacking. Our aim was to analyze the course of pregnancy in our European MMV patient cohort. We retrospectively identified MMV patients with a history of pregnancy who were treated in our institution. We analyzed demographic data, clinical symptoms, treatment, and detailed history of pregnancies. We identified 31 MMV patients (81% moyamoya disease (MMD), 6% unilateral MMD, 13% quasi MMD) with a history of pregnancy resulting in a total of 60 pregnancies and 48 deliveries. Ninety-four percent of the patients became symptomatic by ischemic events and 6% by headache. Eighty-one and nineteen percent of the patients experienced their pregnancies prior to (first group) or after the diagnosis (second group), respectively. In the first group, the mean age at first delivery and bypass treatment were 24 ± 4 and 42 ± 10, respectively. Eight percent of these patients were diagnosed as MMV due to ischemic events during perinatal period. In the second group, the mean age at first delivery and bypass treatment were 26 ± 7 and 23 ± 6, respectively. No cerebral events were reported within perinatal period in this group. All previously operated patients continued their aspirin medication at least until the 3rd trimester. The majority of the pregnancies occurred prior to diagnosis in our European patient cohort. Our data indicates a protective effect of surgical treatment for avoiding cerebral events during pregnancy and delivery for already diagnosed patients.

Resident microglia rather than peripheral macrophages promote vascularization in brain tumors and are source of alternative pro-angiogenic factors.

Myeloid cells are an essential part of the glioblastoma microenvironment. However, in brain tumors the function of these immune cells is not sufficiently clarified. In our study, we investigated differential pro-angiogenic activities of resident microglia and peripheral macrophages and their impact on glioma vascularization and progression. Our data demonstrate stable accumulation of microglia/macrophages during tumor growth. These cells often interact with tumor blood vessels correlating with vascular remodeling. Here, we identified resident microglia as well as peripheral macrophages as part of the perivascular niche, primarily contacting endothelial cells. We found overexpression of a variety of pro-angiogenic molecules within freshly isolated microglia/macrophages from glioma. CXCL2, until now a poorly described chemokine, was strongly up-regulated and showed better angiogenic activity than VEGF in vitro. Blocking the CXCL2-CXCR2 signaling pathway resulted in considerably diminished glioma sizes. Additionally, the importance of microglia/macrophages in tumor angiogenesis was confirmed by depletion of these cells in vivo. Vessel density decreased by 50% leading to significantly smaller tumor volumes. Remarkably, selective reduction of resident microglia affected tumoral vessel count comparable to ablation of the whole myeloid cell fraction. These results provide evidence that resident microglia are the crucial modulatory cell population playing a central role in regulation of vascular homeostasis and angiogenesis in brain tumors. Thus, resident microglia represent an alternative source of pro-angiogenic growth factors and cytokines.

Characterization of Clinical and Radiological Features of Quasi-Moyamoya Disease among European Caucasians Including Surgical Treatment and Outcome.

BACKGROUND: Moyamoya disease (MMD) associated with a potentially underlying disease, such as genetic disorders or other coexisting hematological pathologies, is called quasi-MMD. This very rare disease has been characterized mainly in Asian countries, so far. As MMD reveals several significant ethnic differences, the question is raised whether characteristics of quasi-MMD would also vary among different ethnic backgrounds. Here, we report a series of 61 patients with quasi-MMD and highlight the specific clinical features of this rare disease among European Caucasians. METHODS: We retrospectively identified 61 European Caucasians with quasi-MMD who were treated in our institution between 1997 and 2014. We analyzed demographic data, clinical symptoms, associated diseases, angiographic characteristics and functional hemodynamic studies. RESULTS: Thirty-three percent of our patients were juvenile. We observed an overall female predominance of 2.8:1. Seventy-nine percent presented with a typical quasi-MMD with more pronounced unilateral and atypical quasi-MMD in pediatric population (unilateral/atypical: pediatric patients 20/15%, adults 7/7%). We identified a wide range of associated diseases. Overall, 84 and 8% of our cohort presented initially with ischemic and hemorrhagic manifestation, respectively. The hemorrhagic manifestation of quasi-MMD occurred however only in adults. Angiographic analysis revealed steno-occlusive involvement of the posterior circulation (in addition to the anterior circulation) in 31% with a higher involvement in pediatric patients (40%) compared to adults (27%). CONCLUSIONS: The characterization of our European Caucasian cohort reveals several differences when compared to reported Asian quasi-MMD cohorts and also compared to European Caucasian MMD cohort. We conclude that quasi-MMD represents a distinct disease with different ethnic clinical features.

Radiation Therapy in Alzheimer's Disease: A Systematic Review.

PURPOSE: Pathophysiological hallmarks of Alzheimer's disease (AD) include extracellular amyloid plaques and intracellular neurofibrillary tangles. Recent studies also demonstrated a role of neuroinflammation in the progression of the disease. Clinical trials and animal studies using low-dose radiation therapy (LDRT) have shown therapeutic potential for AD. This systematic review summarizes the current evidence on the use of LDRT for the treatment of AD, outlines potential mechanisms of action, and discusses current challenges in the planning of future trials. METHODS AND MATERIALS: A systematic review of human and animal studies as well as registered clinical trials describing outcomes for RT in the treatment of AD was conducted. We followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles published until July 1, 2023, were included. RESULTS: The initial search yielded 993 articles. After the removal of duplicates and ineligible publications, a total of 16 (12 animal, 4 human) studies were included. Various dose regimens were utilized in both animal and human trials. The results revealed that LDRT reduced the number of amyloid plaques and neurofibrillary tangles, and it has a role in the regulation of genes and protein expression involved in the pathological progression of AD. LDRT has demonstrated reduced astro- and microgliosis, anti-inflammatory and neuroprotective effects, and an alleviation of symptoms of cognitive deficits in animal models. Most studies in humans suggested improvements in cognition and behavior. None of the trials or studies described significant (>grade 2) toxicity. CONCLUSIONS: Preclinical studies, animal studies, and early clinical trials in humans have shown a promising role for LDRT in the treatment of AD pathologies, although the underlying mechanisms are yet to be fully explored. Phase I/II/III trials are needed to assess the long-term safety, efficacy, and optimal treatment parameters of LDRT in AD treatment.

Robotic stereotactic radiosurgery for intracranial meningiomas in elderly patients: assessment of treatment efficacy and safety.

Purpose: Stereotactic radiosurgery (SRS) has been increasingly used to treat intracranial pathologies in elderly patients. The treatment efficiency of SRS has been demonstrated in meningiomas, with excellent local control. We aimed to analyze the safety of robotic SRS in elderly patients with meningiomas. Methods: We searched for patients with suspected WHO °I meningioma ≥ 60 years old, who underwent CyberKnife (CK) SRS from January 2011 to December 2021. Tumor localization was categorized using the "CLASS" algorithmic scale. Tumor response was evaluated using the Response Assessment in Neuro-Oncology (RANO) criteria for meningiomas. Adverse effects were graded using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 and a cox regression was performed to investigate possible predictors. Results: We identified 82 patients with 102 CK-treated lesions that matched the criteria for the first SRS. The median age was 70 [IQR 64-75] years, and 24.3% of the patients were aged > 75 years. Multiple lesions (up to six) were treated in 14.1% of the SRS-sessions. A previous surgery was performed in 57.3% of lesions, with a median time interval of 41 [IQR 10 - 58] months between the initial surgical procedure and the SRS treatment. In 47.9% of cases, CLASS 3 meningiomas at high-risk locations were irradiated. Single fraction radiosurgery was applied to 62.5% of the lesions, while in the remaining cases multi-session SRS with three to five fractions was used. During the median follow-up period of 15.9 months, lesion size progression was observed in 3 cases. Karnofsky Performance Status (KPS) declined by ≥ 20 points in four patients. Adverse effects occurred in 13 patients, while only four patients had CTCAE ≥2 toxicities. Hereby only one of these toxicities was persistent. The occurrence of complications was independent of age, planned target volume (PTV), high-risk localization, and surgery before SRS. Conclusion: The data indicates that SRS is a safe, efficient, and convenient treatment modality for elderly patients with meningioma, even at high-risk locations.

Imaging meningioma biology: Machine learning predicts integrated risk score in WHO grade 2/3 meningioma.

Background: Meningiomas are the most common primary brain tumors. While most are benign (WHO grade 1) and have a favorable prognosis, up to one-fourth are classified as higher-grade, falling into WHO grade 2 or 3 categories. Recently, an integrated risk score (IRS) pertaining to tumor biology was developed and its prognostic relevance was validated in a large, multicenter study. We hypothesized imaging data to be reflective of the IRS. Thus, we assessed the potential of a machine learning classifier for its noninvasive prediction using preoperative magnetic resonance imaging (MRI). Methods: In total, 160 WHO grade 2 and 3 meningioma patients from 2 university centers were included in this study. All patients underwent surgery with histopathological workup including methylation analysis. Preoperative MRI scans were automatically segmented, and radiomic parameters were extracted. Using a random forest classifier, 3 machine learning classifiers (1 multiclass classifier for IRS and 2 binary classifiers for low-risk and high-risk prediction, respectively) were developed in a training set (120 patients) and independently tested in a hold-out test set (40 patients). Results: Multiclass IRS classification had a test set area under the curve (AUC) of 0.7, mostly driven by the difficulties in clearly separating medium-risk from high-risk patients. Consequently, a classifier predicting low-risk IRS versus medium-/high-risk showed a very high test accuracy of 90% (AUC 0.88). In particular, "sphericity" was associated with low-risk IRS classification. Conclusion: The IRS, in particular molecular low-risk, can be predicted from imaging data with high accuracy, making this important prognostic classification accessible by imaging.

The Development and Effect of Systemic Hypertension on Clinical and Radiological Outcome in Adult Moyamoya Angiopathy Following Revascularization Surgery: Experience of a Single European Institution.

Patients with Moyamoya Angiopathy (MMA) display structurally altered vessels with decreased cerebral autoregulatory capacity, so aggressive lowering of systemic hypertension may aggravate ischemic symptoms, whereas uncontrolled hypertension may promote hemorrhage. This study provides an in-depth analysis of the role of hypertension in adult MMA patients including long-term analysis of clinical and radiological development. In this single-center retrospective analysis of 137 adult MMA patients with 206 surgically treated hemispheres angiographic images, clinical/operative data were reviewed and scored. Univariate Cox-regression analysis was performed to evaluate hypertension as a predictor for negative angiographic and clinical outcomes following revascularization surgery. A total of 50% of patients were being treated for hypertension prior to the first surgery. Patients with and without hypertension did not differ in terms of age, gender, diagnosis, symptom onset or disease severity (Berlin and Suzuki Grades). Although hypertension did not statistically significantly affect postoperative collaterals, moyamoya vessels or STA-MCA bypass patency, patients with hypertension showed higher rates of bypass patency and better bypass filling compared to those without hypertension. No significant differences in adverse events were found in patients with and without systemic hypertension and the presence of systemic hypertension was not found to predict negative clinical or radiological outcomes. In conclusion, the rate of systemic hypertension in MMA patients appears to be higher than the general population; however, this is not associated with an increased risk of postoperative complications or negative angiographic development following revascularization procedures. Systemic hypertension may also positively influence the rate of bypass patency and filling following revascularization procedures.

Histopathologically confirmed radiation-induced damage of the brain - an in-depth analysis of radiation parameters and spatio-temporal occurrence.

BACKGROUND: Radiation-induced damage (RID) after radiotherapy (RT) of primary brain tumors and metastases can be challenging to clinico-radiographically distinguish from tumor progression. RID includes pseudoprogression and radiation necrosis; the latter being irreversible and often associated with severe symptoms. While histopathology constitutes the diagnostic gold standard, biopsy-controlled clinical studies investigating RID remain limited. Whether certain brain areas are potentially more vulnerable to RID remains an area of active investigation. Here, we analyze histopathologically confirmed cases of RID in relation to the temporal and spatial dose distribution. METHODS: Histopathologically confirmed cases of RID after photon-based RT for primary or secondary central nervous system malignancies were included. Demographic, clinical, and dosimetric data were collected from patient records and treatment planning systems. We calculated the equivalent dose in 2 Gy fractions (EQD22) and the biologically effective dose (BED2) for normal brain tissue (α/ß ratio of 2 Gy) and analyzed the spatial and temporal distribution using frequency maps. RESULTS: Thirty-three patients were identified. High-grade glioma patients (n = 18) mostly received one normofractionated RT series (median cumulative EQD22 60 Gy) to a large planning target volume (PTV) (median 203.9 ccm) before diagnosis of RID. Despite the low EQD22 and BED2, three patients with an accelerated hyperfractionated RT developed RID. In contrast, brain metastases patients (n = 15; 16 RID lesions) were often treated with two or more RT courses and with radiosurgery or fractionated stereotactic RT, resulting in a higher cumulative EQD22 (median 162.4 Gy), to a small PTV (median 6.7 ccm). All (n = 34) RID lesions occurred within the PTV of at least one of the preceding RT courses. RID in the high-grade glioma group showed a frontotemporal distribution pattern, whereas, in metastatic patients, RID was observed throughout the brain with highest density in the parietal lobe. The cumulative EQD22 was significantly lower in RID lesions that involved the subventricular zone (SVZ) than in lesions without SVZ involvement (median 60 Gy vs. 141 Gy, p = 0.01). CONCLUSIONS: Accelerated hyperfractionated RT can lead to RID despite computationally low EQD22 and BED2 in high-grade glioma patients. The anatomical location of RID corresponded to the general tumor distribution of gliomas and metastases. The SVZ might be a particularly vulnerable area.

Comparison of Choi, RECIST and Somatostatin Receptor PET/CT Based Criteria for the Evaluation of Response and Response Prediction to PRRT.

Aim: The most suitable method for assessment of response to peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors (NET) is still under debate. In this study we aimed to compare size (RECIST 1.1), density (Choi), Standardized Uptake Value (SUV) and a newly defined ZP combined parameter derived from Somatostatin Receptor (SSR) PET/CT for prediction of both response to PRRT and overall survival (OS). Material and Methods: Thirty-four NET patients with progressive disease (F:M 23:11; mean age 61.2 y; SD ± 12) treated with PRRT using either Lu-177 DOTATOC or Lu-177 DOTATATE and imaged with Ga-68 SSR PET/CT approximately 10-12 weeks prior to and after each treatment cycle were retrospectively analyzed. Median duration of follow-up after the first cycle was 63.9 months (range 6.2-86.2). A total of 77 lesions (2-8 per patient) were analyzed. Response assessment was performed according to RECIST 1.1, Choi and modified EORTC (MORE) criteria. In addition, a new parameter named ZP, the product of Hounsfield unit (HU) and SUVmean (Standard Uptake Value) of a tumor lesion, was tested. Further, SUV values (max and mean) of the tumor were normalized to SUV of normal liver parenchyma. Tumor response was defined as CR, PR, or SD. Gold standard for comparison of baseline parameters for prediction of response of individual target lesions to PRRT was change in size of lesions according to RECIST 1.1. For prediction of overall survival, the response after the first and second PRRT were tested. Results: Based on RECIST 1.1, Choi, MORE, and ZP, 85.3%, 64.7%, 61.8%, and 70.6% achieved a response whereas 14.7%, 35.3%, 38.2%, and 29.4% demonstrated PD (progressive disease), respectively. Baseline ZP and ZPnormalized were found to be the only parameters predictive of lesion progression after three PRRT cycles (AUC ZP 0.753; 95% CI 0.6-0.9, p 0.037; AUC ZPnormalized 0.766; 95% CI 0.6-0.9; p 0.029). Based on a cut-off-value of 1201, ZP achieved a sensitivity of 86% and a specificity of 67%, while ZPnormalized reached a sensitivity of 86% and a specificity of 76% at a cut-off-value of 198. Median OS in the total cohort was not reached. In univariate analysis amongst all parameters, only patients having progressive disease according to MORE after the second cycle of PRRT were found to have significantly shorter overall survival (median OS in objective responders not reached, in PD 29.2 months; p 0.015). Patients progressive after two cycles of PRRT according to ZP had shorter OS compared to those responding (median OS for responders not reached, for PD 47.2 months, p 0.066). Conclusions: In this explorative study, we showed that Choi, RECIST 1.1, and SUVmax-based response evaluation varied significantly from each other. Only patients showing progressive disease after two PRRT cycles according to MORE criteria had a worse prognosis while baseline ZP and ZPnormalized performed best in predicting lesion progression after three cycles of PRRT.

Decoding molecular programs in melanoma brain metastases.

Melanoma brain metastases (MBM) variably respond to therapeutic interventions; thus determining patient's prognosis. However, the mechanisms that govern therapy response are poorly understood. Here, we use a multi-OMICS approach and targeted sequencing (TargetSeq) to unravel the programs that potentially control the development of progressive intracranial disease. Molecularly, the expression of E-cadherin (Ecad) or NGFR, the BRAF mutation state and level of immune cell infiltration subdivides tumors into proliferative/pigmented and invasive/stem-like/therapy-resistant irrespective of the intracranial location. The analysis of MAPK inhibitor-naive and refractory MBM reveals switching from Ecad-associated into NGFR-associated programs during progression. NGFR-associated programs control cell migration and proliferation via downstream transcription factors such as SOX4. Moreover, global methylome profiling uncovers 46 differentially methylated regions that discriminate BRAFmut and wildtype MBM. In summary, we propose that the expression of Ecad and NGFR sub- classifies MBM and suggest that the Ecad-to-NGFR phenotype switch is a rate-limiting process which potentially indicates drug-response and intracranial progression states in melanoma patients.