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A growing body of evidence has revealed the potential utility of 5-aminolevulinic acid (5-ALA) as a surgical adjunct in selected lower-grade gliomas. However, a reliable means of identifying which lower-grade gliomas will fluoresce has not been established.To identify clinical and radiological factors predictive of intraoperative fluorescence in intermediate-grade gliomas. In addition, given that higher-grade gliomas are more likely to fluoresce than lower-grade gliomas, we also sought to develop a means of predicting glioma grade.We investigated a cohort of patients with grade II and grade III gliomas who received 5-ALA before resection at a single institution. Using a logistic regression-based model, we evaluated 14 clinical and molecular variables considered plausible determinants of fluorescence. We then distilled the most predictive features to develop a model for predicting both fluorescence and tumor grade. We also explored the relationship between intraoperative fluorescence and diagnostic molecular markers.One hundered seventy-nine subjects were eligible for inclusion. Our logistic regression classifier accurately predicted intraoperative fluorescence in our cohort with 91.9% accuracy and revealed enhancement as the singular variable in determining intraoperative fluorescence. There was a direct relationship between enhancement on MRI and the likelihood of observed fluorescence. Observed fluorescence correlated with MIB-1 index but not with isocitrate dehydrogenase (IDH) status, 1p19q codeletion, or methylguanine DNA methyltransferase promoter methylation.We demonstrate a strong correlation between enhancement on preoperative MRI and the likelihood of visible fluorescence during surgery in patients with intermediate-grade glioma. Our analysis provides a robust method for predicting 5-ALA-induced fluorescence in patients with grade II and grade III gliomas.

Background A methylation-based classification of ependymoma has recently found broad application. However, the diagnostic advantage and implications for treatment decisions remain unclear. Here, we retrospectively evaluate the impact of surgery and radiotherapy on outcome after molecular reclassification of adult intracranial ependymomas. Methods Tumors diagnosed as intracranial ependymomas from 170 adult patients collected from 8 diagnostic institutions were subjected to DNA methylation profiling. Molecular classes, patient characteristics, and treatment were correlated with progression-free survival (PFS). Results The classifier indicated an ependymal tumor in 73.5%, a different tumor entity in 10.6%, and non-classifiable tumors in 15.9% of cases, respectively. The most prevalent molecular classes were posterior fossa ependymoma group B (EPN-PFB, 32.9%), posterior fossa subependymoma (PF-SE, 25.9%), and supratentorial ZFTA fusion-positive ependymoma (EPN-ZFTA, 11.2%). With a median follow-up of 60.0 months, the 5- and 10-year-PFS rates were 64.5% and 41.8% for EPN-PFB, 67.4% and 45.2% for PF-SE, and 60.3% and 60.3% for EPN-ZFTA. In EPN-PFB, but not in other molecular classes, gross total resection (GTR) (P = .009) and postoperative radiotherapy (P = .007) were significantly associated with improved PFS in multivariable analysis. Histological tumor grading (WHO 2 vs. 3) was not a predictor of the prognosis within molecularly defined ependymoma classes. Conclusions DNA methylation profiling improves diagnostic accuracy and risk stratification in adult intracranial ependymoma. The molecular class of PF-SE is unexpectedly prevalent among adult tumors with ependymoma histology and relapsed as frequently as EPN-PFB, despite the supposed benign nature. GTR and radiotherapy may represent key factors in determining the outcome of EPN-PFB patients.

Fluorescence guidance is widely utilized to improve the precision of cancer surgery. 5-aminolevulinic acid, the most widely used fluorophore in glioma surgery, is thought to cause selective accumulation of fluorescent protoporphyrin IX (PpIX) in tumor cells. 5-aminolevulinic acid is highly specific for densely tumor-infiltrated tissue but less effective for visualizing the tumor periphery. To improve clinical detection of PpIX, we developed a microscope to perform paired stimulated Raman histology and two-photon excitation fluorescence microscopy (TPEF) and validated it in 175 fresh tumor specimens from 75 high-grade glioma patients across three institutions. Here, we demonstrate that intracellular PpIX accumulation occurs most prominently in histiocytic, rather than neoplastic, appearing cells. Spatially resolved metabolomics, transcriptomics and RNA sequencing revealed that PPIX is most avidly concentrated in tumor associated macrophages. There was no correlation between the degree of tissue cellularity and PpIX concentration across all imaged specimens (R=-0.21). Our findings encourage reconsideration of the existing theory of 5-ALA-induced glioma cell fluorescence and demonstrate how 5-ALA and TPEF imaging can provide a window into the immune microenvironment of human gliomas.

Rationale: The heterogeneous nature of gliomas makes the development and application of novel treatments challenging. In particular, infiltrating myeloid cells play a role in tumor progression and therapy resistance. Hence, a detailed understanding of the dynamic interplay of tumor cells and immune cells in vivo is necessary. To investigate the complex interaction between tumor progression and therapy-induced changes in the myeloid immune component of the tumor microenvironment, we used a combination of [18F]FET (amino acid metabolism) and [18F]DPA-714 (TSPO, GAMMs, tumor cells, astrocytes, endothelial cells) PET/MRI together with immune-phenotyping. The aim of the study was to monitor temozolomide (TMZ) treatment response and therapy-induced changes in the inflammatory tumor microenvironment (TME). Methods: Eighteen NMRInu/nu mice orthotopically implanted with Gli36dEGFR cells underwent MRI and PET/CT scans before and after treatment with TMZ or DMSO (vehicle). Tumor-to-background (striatum) uptake ratios were calculated and areas of unique tracer uptake (FET vs. DPA) were determined using an atlas-based volumetric approach. Results: TMZ therapy significantly modified the spatial distribution and uptake of both tracers. [18F]FET uptake was significantly reduced after therapy (-53 ± 84%) accompanied by a significant decrease of tumor volume (-17 ± 6%). In contrast, a significant increase (61 ± 33%) of [18F]DPA-714 uptake was detected by TSPO imaging in specific areas of the tumor. Immunohistochemistry (IHC) validated the reduction in tumor volumes and further revealed the presence of reactive TSPO-expressing glioma-associated microglia/macrophages (GAMMs) in the TME. Conclusion: We confirm the efficiency of [18F]FET-PET for monitoring TMZ-treatment response and demonstrate that in vivo TSPO-PET performed with [18F]DPA-714 can be used to identify specific reactive areas of myeloid cell infiltration in the TME.

Background With a growing number of patients on new oral anticoagulants, interest in reversal agents is rising. Andexanet alfa is used for reversal of factor Xa inhibitors in intracranial hemorrhage. Methods We provide a brief review on andexanet-alfa-associated heparin resistance and discuss potentially critical situations from different clinical perspectives. Results Case reports point out that andexanet alfa can cause unresponsiveness to heparin, leading to catastrophic events. As a result, regulatory bodies have issued warning notices to avoid heparinization parallel to the use of andexanet alfa. Conclusions Although well known to hematologists, the phenomenon is underrecognized among stroke clinicians. However, patients with intracranial hemorrhage frequently undergo endovascular or surgical interventions that require periprocedural administration of heparin.

Objective Surgical resection is the therapy of choice in head and neck paraganglioma but is associated with considerable morbidity. For treatment of inoperable or progressive disease, less aggressive adjuvant options are warranted. This study assessed effectiveness and safety of peptide receptor radionuclide therapy (PRRT) with lutetium-177–DOTATATE for head and neck paraganglioma with emphasis on response assessment. Methods A retrospective analysis of 7 patients with head and neck paraganglioma treated with PPRT between May 2014 and October 2016 was performed. Three patients had jugulotympanic paraganglioma, 3 patients had carotid body tumors, and 1 patient had a combination of both. Patients underwent PRRT after discussion in the local tumor board regarding progressive disease, inoperability, or lack of other adjuvant options. All patients underwent 3–5 cycles of PRRT. Treatment response was evaluated by gallium-68–DOTATATE positron emission tomography/computed tomography and contrast-enhanced computed tomography or magnetic resonance imaging. Outcome measures were two-dimensional tumor diameters and total tumor volumes. Results Median patient age was 60 years (interquartile range: 14–84 years). All patients had stable disease at posttherapy assessment. Decreasing tumor volumes were found in 4 patients. Clinical symptoms improved in 2 patients. No progression or adverse events occurred during a median follow-up of 39 months (interquartile range: 35–47 months). Conclusions Somatostatin receptor–targeted therapy using lutetium-177-DOTATATE shows promising effectiveness with a high safety profile. Patients in whom surgical morbidity outweighs oncologic benefit should be informed about PRRT as a treatment option.

OBJECTIVEDecompressive craniectomies (DCs) are performed on patients suffering large cerebral infarctions. The efficacy of this procedure has been demonstrated in several trials. In some cases, however, this procedure alone is not sufficient and patients still suffer refractory elevations of intracranial pressure (ICP). The goal of this study was to determine whether resection of infarcted tissue, termed strokectomy, performed as a second-look procedure after DC, improves outcome in selected cases.METHODSThe authors retrospectively evaluated data of patients who underwent a DC due to a cerebral infarction at their institution from 2009 to 2016, including patients who underwent a strokectomy procedure after DC. Clinical records, imaging data, outcome scores, and neurological symptoms were analyzed, and clinical outcomes and mortality rates in the strokectomy group were compared to those for similar patients in recently published randomized controlled trials.RESULTSOf 198 patients who underwent DC due to cerebral infarction, 12 patients underwent strokectomy as a second surgical procedure, with a median National Institutes of Health Stroke Scale (NIHSS) score of 19 for patients with versus 16 for those without secondary strokectomy (p = 0.029). Either refractory increases of ICP > 20 mm Hg or dilated pupils in addition to herniation visible on CT images were triggers for strokectomy surgery. Ten of 12 (83%) patients had infarctions in more than one territory (p < 0.001). After 12 months, 43% of patients had a good outcome according to the modified Rankin Scale (mRS) score (≤ 3). In the subgroup of patients suffering infarctions in more than one vascular territory, functional outcome after 12 months was better (mRS ≤ 3 in 40% of patients in comparison to 9%; p = 0.027). A 1:3 case-control analysis matched to age, side of infarction, sex, and vascular territory confirmed these results (mRS ≤ 3, 42% in comparison to 11%; p = 0.032). Age, NIHSS score on admission, and number of vascular territories involved were identified as risk factors in multivariate analysis (p < 0.05). Patients in the strokectomy group had more infections (p < 0.001). According to these results, the authors developed a scale (Münster Stroke Score, 0–6 points) to predict whether patients might benefit from additional strokectomy. Receiver-operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.86 (p < 0.001). The authors recommend a Münster Stroke Score of ≥ 3 as a cutoff, with a sensitivity of 92% and specificity of 66%, for predicting benefit from strokectomy.CONCLUSIONSIn this study in comparison to former studies, mortality rates were lower and clinical outcome was comparable to that of previously published trials regarding large cerebral infarctions. Second surgery including strokectomy may help achieve better outcomes, especially in cases of infarction of more than one vascular territory.

Hemangioblastomas (HBs) of the central nervous system are highly vascular neoplasms that occur sporadically or as a manifestation of von Hippel-Lindau (VHL) disease. Despite their benign nature, HBs are clinically heterogeneous and can be associated with significant morbidity due to mass effects of peritumoral cysts or tumor progression. Underlying molecular factors involved in HB tumor biology remain elusive. We investigated genome-wide DNA methylation profiles and clinical and histopathological features in a series of 47 HBs from 42 patients, including 28 individuals with VHL disease. Thirty tumors occurred in the cerebellum, 8 in the brainstem and 8 HBs were of spinal location, while 1 HB was located in the cerebrum. Histologically, 12 HBs (26%) belonged to the cellular subtype and exclusively occurred in the cerebellum, whereas 35 HBs were reticular (74%). Unsupervised clustering and dimensionality reduction of DNA methylation profiles revealed two distinct subgroups. Methylation cluster 1 comprised 30 HBs of mainly cerebellar location (29/30, 97%), whereas methylation cluster 2 contained 17 HBs predominantly located in non-cerebellar compartments (16/17, 94%). The sum of chromosomal regions being affected by copy-number alterations was significantly higher in methylation cluster 1 compared to cluster 2 (mean 262 vs. 109 Mb, p = 0.001). Of note, loss of chromosome 6 occurred in 9/30 tumors (30%) of methylation cluster 1 and was not observed in cluster 2 tumors (p = 0.01). No relevant methylation differences between sporadic and VHL-related HBs or cystic and non-cystic HBs could be detected. Deconvolution of the bulk DNA methylation profiles revealed four methylation components that were associated with the two methylation clusters suggesting cluster-specific cell-type compositions. In conclusion, methylation profiling of HBs reveals 2 distinct subgroups that mainly associate with anatomical location, cytogenetic profiles and differences in cell type composition, potentially reflecting different cells of origin.

Background: Concepts improving local tumor control in high-grade glioma (HGG) are desperately needed. The aim of this study is to report an extended series of cases treated with a combination of 5-ALA-fluorescence-guided resection (FGR) and intracavitary thermotherapy with superparamagnetic iron oxide nanoparticles (SPION). Methods: We conducted a single-center retrospective review of all recurrent HGG treated with FGR and intracavitary thermotherapy (n = 18). Patients underwent six hyperthermia sessions in an alternating magnetic field and received additional adjuvant therapies on a case-by-case basis. Results: Nine patients were treated for first tumor recurrence; all other patients had suffered at least two recurrences. Nine patients received combined radiotherapy and thermotherapy. The median progression-free survival was 5.5 (95% CI: 4.67–6.13) months and median overall survival was 9.5 (95% CI: 7.12–11.79) months. No major side effects were observed during active treatment. Thirteen patients (72%) developed cerebral edema and more clinical symptoms during follow-up and were initially treated with dexamethasone. Six (33%) of these patients underwent surgical removal of nanoparticles due to refractory edema. Conclusions: The combination of FGR and intracavitary thermotherapy with SPION provides a new treatment option for improving local tumor control in recurrent HGG. The development of cerebral edema is a major issue requiring further refinements of the treatment protocol.

Fluorescence guidance is widely utilized to improve the precision of cancer surgery. 5-aminolevulinic acid, the most widely used fluorophore in glioma surgery, is thought to cause selective accumulation of fluorescent protoporphyrin IX (PpIX) in tumor cells by exploiting pathologic alterations in heme biosynthetic pathways. PpIX-induced fluorescence is highly specific for densely tumor-infiltrated tissue but less effective for visualizing the tumor periphery. To improve clinical detection of PpIX, we developed a microscope to perform paired stimulated Raman histology and two-photon excitation fluorescence microscopy (TPEF) and validated it in 175 fresh, unprocessed core tumor specimens from 75 high-grade glioma patients and three central nervous system lymphoma patients across three institutions. Surprisingly, intracellular PpIX accumulation was observed primarily in cells with histiocytic, rather than neoplastic morphology, and the number of cells concentrating PpIX within the cytoplasm was associated with the abundance of CD163 positive cells (p< 0.02). There was no correlation between the degree of tumor cellularity and the concentration of PpIX across all imaged specimens (R=-0.21). Our findings encourage reconsideration of the existing theory of 5-ALA-induced tumor cell fluorescence in gliomas and demonstrate how 5-ALA and TPEF imaging can provide a window into the immune microenvironment of human gliomas.

PURPOSE Satisfaction with work-life balance (WLB) is an essential factor for persistent motivation of early career researchers. However, WLB satisfaction in the neuro-oncological landscape is not well characterized. We present the results of an interdisciplinary survey focusing on WLB satisfaction among neuro-oncologists in Germany. METHODS The questionnaire was sent to 351 physicians, all of whom were members of the Neuro-oncology Working Group “Neuroonkologische Arbeitsgemeinschaft” (NOA) of the German Cancer Society (Deutsche Krebsgesellschaft, DKG). The participants were asked for personal information, individual motivations, scientific interests, activities, individual workload, and job satisfaction. The questionnaire was accessible from 18 March 2021 to 1 April 2021. RESULTS Ninety-six physicians (36 female, 60 male) participated in this survey. Age, gender and relationship status were significantly different between participants who were satisfied and those not satisfied with their WLB. Female participants were less likely to be satisfied with their WLB than male participants (25% vs 75%, p = 0.005). In a logistic regression model, the finding that female participants were less likely to be satisfied with their WLB than male participants remained statistically significant (odds ratio [OR] 0.32; 95% confidence interval [CI] 0.21–0.84, p = 0.023) after accounting for possible confounding variables such as age (OR 1.06; 95% CI 1.01–1.11, p = 0.025), childlessness (children available vs not available, OR 0.40; 95% CI 0.10–1.35, p = 0.156), and relationship status (unmarried vs single, OR 2.49; 95% CI 0.50–13.98, p = 0.275; married vs single, OR 6.18; 95% CI 1.29–35.46, p = 0.029). CONCLUSIONS This survey demonstrates that WLB satisfaction is significantly decreased among female neuro-oncologists in Germany. It highlights the importance of programs such as “Diversity in Neurooncology” (DivINe), founded by the NOA and aiming to address gender disparities.

Primary central nervous system lymphoma (PCNSL) is a rare lymphoma of the central nervous system, usually of diffuse large B cell phenotype. Stereotactic biopsy followed by histopathology is the diagnostic standard. However, limited material is available from CNS biopsies, thus impeding an in-depth characterization of PCNSL.We performed flow cytometry, single-cell RNA sequencing, and B cell receptor sequencing of PCNSL cells released from biopsy material, blood, and cerebrospinal fluid (CSF), and spatial transcriptomics of biopsy samples.PCNSL-released cells were predominantly activated CD19sup+/supCD20sup+/supCD38sup+/supCD27sup+/supB cells. In single-cell RNA sequencing, PCNSL cells were transcriptionally heterogeneous, forming multiple malignant B cell clusters. Hyperexpanded B cell clones were shared between biopsy- and CSF- but not blood-derived cells. T cells in the tumor microenvironment upregulated immune checkpoint molecules, thereby recognizing immune evasion signals from PCNSL cells. Spatial transcriptomics revealed heterogeneous spatial organization of malignant B cell clusters, mirroring their transcriptional heterogeneity across patients, and pronounced expression of T cell exhaustion markers, co-localizing with a highly malignant B cell cluster.Malignant B cells in PCNSL show transcriptional and spatial intratumor heterogeneity. T cell exhaustion is frequent in the PCNSL microenvironment, co-localizes with malignant cells, and highlights the potential of personalized treatments.

OBJECTIVE Administration of 5-aminolevulinic acid (5-ALA) does not regularly elicit fluorescence in low-grade glioma (LGG) at currently established doses and timing of administration. One explanation may be differences in blood-brain barrier (BBB) integrity compared to high-grade glioma. The authors hypothesized that for a BBB semipermeable to 5-ALA there might be a relationship between plasma 5-ALA concentration and its movement into the brain. A higher dose would elicit more 5-ALA conversion into protoporphyrin IX (PPIX). The authors present a case series of patients harboring LGG who received higher doses of 5-ALA. METHODS Patients undergoing surgery for indeterminate glioma later diagnosed as LGG were included in this study. 5-ALA was administered at a standard dose of 20 mg/kg body weight (bw) 4 hours prior to induction of anesthesia. A subgroup of patients received a higher dose of 40 mg/kg bw. Fluorescence was evaluated visually and PPIX concentration (cPPIX) was determined ex vivo by hyperspectral measurements in freshly extracted tissue. All adverse events were recorded. RESULTS A total of 23 patients harboring diffuse low-grade astrocytomas (n = 19) and oligodendrogliomas (n = 4) were analyzed. Thirteen patients received 20 mg/kg bw, and 10 patients received 40 mg/kg bw of 5-ALA. In the 20 mg/kg group, 30.8% (4 of 13) of tumors harbored areas of visible fluorescence, compared to 60% of cases (n = 6 of 10) with 40 mg/kg bw. The threshold to visibility was 1 μg/ml in both groups. Measured over all biopsies, the mean cPPIX was significantly higher in the double-dose group (1.8 vs 0.45 μg/ml; p < 0.001). In non–visibly fluorescent tissue the mean cPPIX was 0.146 μg/ml in the 20 mg/kg and 0.347 μg/ml in the 40 mg/kg group, indicating an increase of 138% (p < 0.001). CONCLUSIONS These observations demonstrate different regions with different levels of PPIX accumulation in LGG. With higher 5-ALA doses cPPIX increases, leading to more regions surpassing the visibility threshold of 1 μg/ml. These observations can be explained by the fact that the BBB in LGG is semipermeable to 5-ALA. Higher 5-ALA doses result in more PPIX conversion, an observation with implications for future dosing in LGG.

5-Aminolevulinic acid (5-ALA)–guided resection of gliomas in adults enables better delineation between tumor and normal brain, allowing improved resection and improved patients’ outcome. Recently, several reports were published regarding 5-ALA for resection of pediatric brain tumors. The aim of the study was to determine the intracellular fluorescence of protoporphyrin IX (PPIX) in pediatric brain tumors by hyperspectral imaging and to compare it with visually observed intraoperative fluorescence. 5-ALA was administered orally 4 h prior to surgery. During tumor resection, the surgeon assessed the fluorescence signal to be strong, weak, or absent. Subsequently, fluorescence intensity of tumor samples was measured via spectroscopy. In addition, clinical data, imaging, and laboratory data were analyzed. Eleven children (1–16 years) were operated. Tumor entities included three (n = 3) medulloblastomas, two (n = 2) pilocytic astrocytomas (PA), two (n = 2) anaplastic ependymomas and one (n = 1) diffuse astrocytoma, anaplastic astrocytoma (n = 1), pilomyxoid astrocytoma (n = 1) and anaplastic pleomorphic xanthoastrocytoma (n = 1). Strong fluorescence was visible in all anaplastic tumors and one PA; one PA demonstrated weak fluorescence. Visible fluorescence was strongly associated with intracellular fluorescence intensity and PPIX concentration (P

BACKGROUND: 5-Aminolevulinic acid (5-ALA)-guided resection of gliomas in adults enables better differentiation between tumor and normal brain, allowing a higher degree of resection, and improved patient outcomes. In recent years, several reports have emerged regarding the use of 5-ALA in other brain tumor entities, including pediatric brains tumors. Since gross total resection (GTR) of many brain tumors in children is crucial, the role of 5-ALA-guided resection requires elucidation. METHODS: A systematic literature review of EMBASE and MEDLINE/PubMed databases revealed 20 eligible publications encompassing 186 5-ALA-guided operations on pediatric brain tumors. To reduce bias, publications were revised independently by two authors. RESULTS: 5-ALA-guided resection enabled the surgeons to identify the tumor more easily and was considered helpful mainly in cases of glioblastoma (GBM, 21/27, 78%), anaplastic ependymoma WHO grade III (10/14, 71%), and anaplastic astrocytoma (4/6, 67%). In contrast, cases of pilocytic astrocytomas (PAs) and medulloblastomas 5-ALA-guided surgery did not show consistent fluorescent signals and 5-ALA was considered helpful only in 12% and 22% of cases, respectively. Accumulation of fluorescent porphyrins seems to depend on WHO tumor grading. In case fluorescence signal was considered helpful, it was associated to a greater degree of resection. One study showed an association between visible fluoresce signal and concentration of protopophyrin IX (PPIX) concentration. A threshold of 4μg/ml was required in order to visualize the fluorescence signal. The rate of adverse events related to 5-ALA was negligible, especially new postoperative sequelae. CONCLUSION: 5-ALA could play a role in resection of malignant, contrast enhancing, supratentorial pediatric brain tumors. At present, we are conducting a prospective phase I-II multicenter clinical trial to evaluate side effects and feasibility of 5-ALA guided surgery

Subependymomas are benign tumors characteristically encountered in the posterior fossa of adults that show distinct epigenetic profiles assigned to the molecular group “subependymoma, posterior fossa” (PFSE) of the recently established DNA methylation-based classification of central nervous system tumors. In contrast, most posterior fossa ependymomas exhibit a more aggressive biological behavior and are allocated to the molecular subgroups PFA or PFB. A subset of ependymomas shows epigenetic similarities with subependymomas, but the precise biology of these tumors and their potential relationships remain unknown. We therefore set out to characterize epigenetic traits, mutational profiles, and clinical outcomes of 50 posterior fossa ependymal tumors of the PFSE group. On histo-morphology, these tumors comprised 12 ependymomas, 14 subependymomas and 24 tumors with mixed ependymoma–subependymoma morphology. Mixed ependymoma–subependymoma tumors varied in their extent of ependymoma differentiation (2–95%) but consistently exhibited global epigenetic profiles of the PFSE group. Selective methylome analysis of microdissected tumor components revealed CpG signatures in mixed tumors that coalesce with their pure counterparts. Loss of chr6 (20/50 cases), as well as TERT mutations (21/50 cases), were frequent events enriched in tumors with pure ependymoma morphology (p TERT mutations were associated with shorter progression-free survival (each p

Background Giant cell tumors of the bone (GCTB) are rare bone tumors, especially in the cervical spine. Generally considered benign, local aggressiveness and metastatic growth have been described. Surgical concepts for GCTB are challenged by complex neurovascular anatomy. Specific clinical management guidelines are nonexistent. This systematic review aims to compile existing evidence on the treatment of GCTB of the cervical spine. Methods Four electronic databases were searched: Medline, Embase, Web of Science, and Cochrane Library. All clinical studies reporting the treatment of GCTB in the human cervical spine in English language were found eligible for review. Results Seven studies were included in the synthesis including a total number of 54 patients. Of those patients, 46 (85%) were treated for naive nonrecurrent GCTB. Only 1 study is considered a cohort study; all other studies were case reports. Generally, intralesional procedures were performed in 13 (24%) cases. Subtotal resections were reported for 11 (20%) patients. Twenty-eight (52%) patients were surgically treated with piecemeal resection, en-bloc resection, or spondylectomy. Thirty-six (67%) patients underwent adjuvant radiotherapy. A combination of radiotherapy and chemotherapy was reported in 2 (4%) cases. Bisphosphonates were prescribed for 9 (17%) patients. Inconsistent reporting of outcome data did not allow for comparative analyses. Conclusions Best available evidence suggests that the most aggressive surgical approach should be the main goal of any GCTB surgery. No specific adjuvant or neoadjuvant treatment can be recommended as superior due to a lack of comparative data. Therapeutic approaches need to be planned thoroughly on an individual basis.

Background In somatostatin receptor (SSTR) expressing progressive meningioma, peptide receptor radionuclide therapy (PRRT) has shown effect in small clinical series. However, standardized treatment and response assessment protocols are lacking. We present our experience on PPRT with 177Lu-DOTATATE in progressive meningioma with a special emphasis on state-of-the-art response assessment. Methods Retrospective analysis on PRRT with 177Lu-DOTATATE from 2015 to 2019. Pre- and post-therapy imaging was performed using MRI and 68Ga-DOTATATE-PET for standard bidimensional and volumetric analyses, respectively, following novel RANO guidelines. Results Seven patients with progressive intracranial meningioma (median age 73 years, interquartile range 60–76; 5 WHO II, 2 WHO I; 5 multifocal) received a median of 4 cycles 2 3 4 of PRRT with 177Lu-DOTATATE in eight-week intervals. Three patients did not undergo post-therapy 68Ga-DOTATATE-PET due to early symptomatic progression and subsequent cessation of PRRT. After completion of 4 PRRT cycles volumetric PET imaging showed stable disease in two of four patients. According to bidimensional MRI response assessment, only one patient was stable. Progression free survival at six months was 42.9 %. Conclusion In this heterogeneous collective of seven patients with progressive meningioma, 177Lu-DOTATATE therapies showed heterogeneous effectiveness. PET-based volumetric assessment should be used for response assessment in PRRT additionally to bidimensional imaging.

Background Blunt cerebrovascular injuries (BCVI) can significantly impact morbidity and mortality if undetected and, therefore, untreated. Two diagnostic concepts are standard practice in major trauma management: Application of clinical screening criteria (CSC) does or does not recommend consecutive computed tomography angiography (CTA) of head and neck. In contrast, liberal CTA usage integrates into diagnostic protocols for suspected major trauma. First, this study's objective is to assess diagnostic accuracy of different CSC for BCVI in a population of patients diagnosed with BCVI after the use of liberal CTA. Second, anatomical locations and grades of BCVI in CSC false negatives are analyzed. Methods The hospital database at University Hospital Munster was retrospectively searched for BCVI diagnosed in patients with suspicion of major trauma 2008 to 2015. All patients underwent a diagnostic protocol including CTA. No BCVI risk stratification or CSC had been applied beforehand. Three sets of CSC were drawn from current BCVI practice management guidelines and retrospectively applied to the study population. Primary outcome was false-negative recommendation for CTA according to CSC. Secondary outcome measures were stroke, mortality, mechanism of injury, multivessel BCVI, location and grade of BCVI. Results From 4,104 patients with suspicion of major trauma, 91 (2.2%) were diagnosed with 126 BCVI through liberal usage of CTA. Sensitivities of different CSC ranged from 57% to 84%. Applying the set of CSC with the highest sensitivity, false-negative BCVIs were found more often in the petrous segment of the carotid artery (p = 0.01) and more false negatives presenting with pseudoaneurysmatic injury were found in the vertebral artery (p = Conclusion This study provides further insight into the common debate of correct assessment of BCVI in trauma patients. Despite following current practice management guidelines, a large number of patients with BCVI would have been missed without liberal CTA usage. Larger-scale observational studies are needed to confirm these results. Level of evidence Diagnostic study, Level III.

Background Tumor-associated microglia and macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) are potent immunosuppressors in the glioma tumor microenvironment (TME). Their infiltration is associated with tumor grade, progression, and therapy resistance. Specific tools for image-guided analysis of spatiotemporal changes in the immunosuppressive myeloid tumor compartments are missing. We aimed (i) to evaluate the role of fluorodeoxyglucose (18F)DPA-714* (translocator protein [TSPO]) PET-MRI in the assessment of the immunosuppressive TME in glioma patients, and (ii) to cross-correlate imaging findings with in-depth immunophenotyping. Methods To characterize the glioma TME, a mixed collective of 9 glioma patients underwent [18F]DPA-714-PET-MRI in addition to [18F]fluoro-ethyl-tyrosine (FET)-PET-MRI. Image-guided biopsy samples were immunophenotyped by multiparametric flow cytometry and immunohistochemistry. In vitro autoradiography was performed for image validation and assessment of tracer binding specificity. Results We found a strong relationship (r = 0.84, P = 0.009) between the [18F]DPA-714 uptake and the number and activation level of glioma-associated myeloid cells (GAMs). TSPO expression was mainly restricted to human leukocyte antigen D related–positive (HLA-DR+) activated GAMs, particularly to tumor-infiltrating HLA-DR+ MDSCs and TAMs. [18F]DPA-714–positive tissue volumes exceeded [18F]FET-positive volumes and showed a differential spatial distribution. Conclusion [18F]DPA-714-PET may be used to non-invasively image the glioma-associated immunosuppressive TME in vivo. This imaging paradigm may also help to characterize the heterogeneity of the glioma TME with respect to the degree of myeloid cell infiltration at various disease stages. [18F]DPA-714 may also facilitate the development of new image-guided therapies targeting the myeloid-derived TME.

5-Aminolevulinic acid (5-ALA) is a useful and well-established adjunct for glioblastoma surgery. A growing body of evidence has revealed the potential utility of 5-ALA in grade II and grade III glioma patients as well. However, reliable means of identifying in whom fluorescence will occur have not been established. The authors report the case of such an indeterminate-grade glioma highlighting two pearls of 5-ALA fluorescence in this subgroup of patients. Firstly, 5-ALA–guided tissue sampling helps to ensure that the true grade of the lesion is not underestimated. Secondly, intraoperative fluorescence can serve as a prognostic marker. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21196

Objective Stand-alone minimally invasive approaches for the surgical management of spinal dumbbell tumors carry the risk of incomplete resections and impaired hemostasis. More-extensive approaches require subsequent instrumentation with metal artifacts impairing follow-up imaging. Here, we present a technical note on percutaneous instrumentation using carbon fiber–reinforced polyether ether ketone (CFR-PEEK) hardware combined with a minimally invasive posterolateral approach for tumor resection. Methods We present a Technical Note and according case series of 7 patients with dumbbell tumors in the lumbar and thoracolumbar spine operated on between 2017 and 2020. CFR-PEEK pedicle screws and rods were inserted percutaneously. Afterwards, a dedicated self-standing retractor for posterolateral approaches was connected to the screws. Following a unilateral facetectomy, the tumor was resected in a microsurgical fashion. Clinical data are reported with respect to the Preferred Reporting Of CasE Series in Surgery (PROCESS) guidelines. Results Four patients presented with de novo tumors. Three patients were treated for residual tumor mass after previous surgeries. Gross total resection was achieved in all 7 cases, as demonstrated by early postoperative magnetic resonance imaging. Histopathology demonstrated 5 World Health Organization grade I schwannomas, 1 grade II hemangiopericytoma, and 1 cavernous hemangioma. No postoperative complications were observed. CFR-PEEK hardware allowed unambiguous visualization of the resection cavity on follow-up imaging. Conclusions Resection of dumbbell tumors via a minimally invasive posterolateral approach and instrumentation with CFR-PEEK hardware allows maximal and safe resection. Due to lack of major metal artifacts, carbon fiber hardware improves the interpretation of follow-up imaging as well as planning of radiation if required for tumor recurrence.

Between tumor and normal brain, allowing a higher degree of resection, and improved patient outcomes. In recent years, several reports have emerged regarding the use of 5-ALA in other brain tumor entities, including pediatric brains tumors. Since gross total resection (GTR) of many brain tumors in children is crucial, the role of 5-ALA-guided resection requires elucidation. Methods A systematic literature review of EMBASE and MEDLINE/PubMed databases revealed 20 eligible publications encompassing 186 5-ALA-guided operations on pediatric brain tumors. To reduce bias, publications were revised independently by two authors. Results 5-ALA-guided resection enabled the surgeons to identify the tumor more easily and was considered helpful mainly in cases of glioblastoma (GBM, 21/27, 78%), anaplastic ependymoma WHO grade III (10/14, 71%), and anaplastic astrocytoma (4/6, 67%). In contrast, cases of pilocytic astrocytomas (PAs) and medulloblastomas 5-ALA-guided surgery did not show consistent fluorescent signals and 5-ALA was considered helpful only in 12% and 22% of cases, respectively. Accumulation of fluorescent porphyrins seems to depend on WHO tumor grading. In case fluorescence signal was considered helpful, it was associated with a greater degree of resection. One study showed an association between visible fluoresce signal and concentration of protopophyrin IX (PPIX) concentration. A threshold of 4μg/ml was required in order to visualize the fluorescence signal. The rate of adverse events related to 5-ALA was negligible, especially new postoperative sequelae. Conclusion 5-ALA could play a role in resection of malignant, contrast enhancing, supratentorial pediatric brain tumors. At present, we are conducting a prospective phase I-II multicenter clinical trial to evaluate side effects and feasibility of 5-ALA guided surgery.

BACKGROUND We recently showed that intracavitary thermotherapy with superparamagnetic iron-oxide nanoparticles can induce persistent inflammatory reactions which might lead to long-term stabilization in recurrent glioblastoma (GBM) patients. METHODS Here, we report further data from a series of ten recurrent GBM WHO IV patients (IDH WT, MGMT: methylated 30%, unmethylated 70%; median age: 59 years) who were treated with intracavitary thermotherapy after coating the resection cavity wall (“NanoPaste”) with NanoTherm® particles (MagForce AG, Berlin, Germany). All patients underwent six one-hour semi-weekly hyperthermia sessions in an alternating magnetic field (mean maximum temperature 52.3° C, SD +/- 6.0 °C). Six patients received concurrent radiotherapy at a dose of 39.6 Gy (5 x 1.8 Gy/week). RESULTS No major side effects were observed during active treatment. However, all patients developed cerebral edema and increasing clinical symptoms during treatment follow-up (median 92 days, range 73 to 144). Patients were treated with dexamethasone and, if necessary, underwent re-operation to remove nanoparticles (n=5). Histopathology revealed sustained necrosis and large amounts of nanoparticles without evidence for tumor activity as well as a prominent inflammatory reaction characterized by increased T-cell and myeloid cell infiltration. Median overall survival (mOS) for the study population was 10.1 months (CI 95% 8.0–12.2). A survival benefit was observed for patients treated at first recurrence (n=5) when compared to patients treated at second recurrence or later (mOS = 20.6 vs 9.4 months). Patients who received thermotherapy and concurrent radiotherapy (n=6) showed longer mOS than patients treated with thermotherapy alone (17.3 vs 8.6 months). Two patients had long-lasting treatment responses > 23 months with one patient still alive at 3.5 years after treatment without receiving any further therapy. CONCLUSION Our results warrant further investigations. A European clinical registry will be rolled out to further evaluate the potential of “NanoPaste” therapy for patients with recurrent glioblastoma.

OBJECTIVEHigh-grade glioma (HGG) prognosis remains dismal, with inevitable, mostly local recurrence. Regimens for improving local tumor control are therefore needed. Photodynamic therapy (PDT) using porfimer sodium has been investigated but was abandoned due to side effects and lack of survival benefits. Intracellular porphyrins induced by 5-aminolevulinic acid (5-ALA) are approved for fluorescence-guided resections (FGRs), but are also photosensitizers. Activated by light, they generate reactive oxygen species with resultant cytotoxicity. The authors present a combined approach of 5-ALA FGR and PDT.METHODSAfter 5-ALA FGR in recurrent HGG, laser diffusors were strategically positioned inside the resection cavity. PDT was applied for 60 minutes (635 nm, 200 mW/cm diffusor, for 1 hour) under continuous irrigation for maintaining optical clarity and ventilation with 100% oxygen. MRI was performed at 24 hours, 14 days, and every 3 months after surgery, including diffusion tensor imaging and apparent diffusion coefficient maps.RESULTSTwenty patients were treated. One surgical site infection after treatment was noted at 6 months as the only adverse event. MRI revealed cytotoxic edema along resection margins in 16 (80%) of 20 cases, mostly annular around the cavity, corresponding to prior laser diffusor locations (mean volume 3.3 cm3). Edema appeared selective for infiltrated tissue or nonresected enhancing tumor. At the 14-day follow-up, enhancement developed in former regions of edema, in some cases vanishing after 4–5 months. Median progression-free survival (PFS) was 6 months (95% CI 4.8–7.2 months).CONCLUSIONSCombined 5-ALA FGR and PDT provides an innovative and safe method of local tumor control resulting in promising PFS. Further prospective studies are warranted to evaluate long-term therapeutic effects.

Fluorescence in the ventricular wall or the ependyma during fluorescence-guided resection (FGR) of malignant glioma is commonly observed when malignant gliomas infiltrate the ventricles. However, the underlying pathophysiology and clinical importance are largely unknown but may play a role in deciding whether to continue resection into the ventricles or not. Here, we systematically review available data regarding ependymal fluorescence in FGR using five aminolevulinic acid (5-ALA) and sodium fluorescein (SF). A literature search on MEDLINE, EMBASE, and WEB OF SCIENCE was performed using the following headings and search operators: ependy* fluorescence AND (5-ALA OR five aminolevulinic acid), ventric* wall fluorescence AND (5-ALA OR five aminolevulinic acid), ependy* fluorescence AND fluorescein, and ventric* wall fluorescence AND fluorescein. Both authors analyzed abstracts independently. Included articles were further reviewed for prevalence of ependymal fluorescence, patterns of fluorescence, and histopathological characteristics of sampled tissues as well as radiological signs of ependymal fluorescence. Results are reported according to the PRISMA statement. Of 202 records identified, 6 studies were included compiling a total number of 198 patients treated with FGR using 5-ALA. No study on ependymal fluorescence after administration of SF was found. Overall prevalence of ependymal fluorescence was 61.4%. A total of 54.5% of cases were found to be positive for tumor cells. A total of 25.5% of patients with ependymal fluorescence were related to contrast enhancement in ventricular walls. The phenomenon of ventricular wall fluorescence in 5-ALA-derived fluorescence-guided resection of malignant glioma is poorly understood and not always may fluorescence represent tumor infiltration. A larger scale prospective sampling study with molecular analyses is currently ongoing and will hopefully provide further insight into pathophysiology and clinical implications of ependymal fluorescence.

BACKGROUND Progressive meningioma is a challenging condition with a decreasing number of treatment options over the course of disease. Neurovascular involvement and multifocal disease often complicate surgical management. In addition, repeated radiotherapy carriers a risk of side effects. In somatostatin receptor expressing meningioma, peptide receptor radiotherapy (PPRT) with 177Lu-DOTATATE poses a promising alternative. However, current evidence is scarce. Hereby we present our single center experience of (PPRT) with 177Lu-DOTATATE in progressive meningioma. METHODS Eight patients (median age: 71 years; range 56–77) with progressive meningioma underwent PRRT using 177Lu-DOTATATE were included in this retrospective analysis. Response to therapy was assessed by interim and post-therapy 68Ga-DOTATATE-PET-CT and MRI. 177Lu-DOTATATE scintigraphies 48h p.i. were evaluated according to Krenning scale. Additionally, clinical outcome and follow up imaging were analyzed for progression free interval times. RESULTS Eight patients were included: Six patients with grade II and two patients with grade I meningiomas, according to the 2016 WHO classification. Six of eight patients harbored multifocal disease. One patients suffered systemic metastatic disease. Patients received a median of three cycles (range: 1 - 5) of PRRT with 177Lu-DOTATATE (mean injected dose 7.1 GBq) between 1/2015 and 1/2019. Tumor uptake in 48h p.i. 177Lu-Scintigraphies was heterogeneous (Krenning scale; median: 3; range: 1–4). Post-therapy imaging scheduled eight weeks after completion of therapy showed progressive disease in five patients, three patients had stable disease. Median follow-up post therapy response evaluation was 24 months in patients with stable disease. Median time to progression was 10 months. CONCLUSION In this cohort of eight progressive meningioma patients 177Lu-DOTATATE therapy showed heterogeneous efficacy.

5-Aminolevulinic acid (5-ALA)-guided resection of gliomas in adults enables better differentiation between tumor and normal brain tissue, allowing a higher degree of resection, and improves patient outcomes. In recent years, several reports have emerged regarding the use of 5-ALA in other brain tumor entities, including pediatric brains tumors. Since gross total resection (GTR) of many brain tumors in children is crucial and the role of 5-ALA-guided resection of these tumors is not clear, we sought to perform a comprehensive literature review on this topic. A systematic literature review of EMBASE and MEDLINE/PubMed databases revealed 19 eligible publications encompassing 175 5-ALA-guided operations on pediatric brain tumors. To prevent bias, publications were revised independently by two authors. We found that 5-ALA-guided resection enabled the surgeons to identify the tumor more easily and was considered helpful mainly in cases of glioblastoma (GBM, 21/27, 78%), anaplastic ependymoma WHO grade III (10/14, 71%), and anaplastic astrocytoma (4/6, 67%). In contrast, cases of pilocytic astrocytomas (PAs) and medulloblastomas 5-ALA-guided surgery did not show consistent fluorescent signals and 5-ALA was considered helpful only in 12% and 22% of cases, respectively. Accumulation of fluorescent porphyrins seems to depend on WHO tumor grading. One important finding is that when 5-ALA-guided resections were considered helpful, the degree of resection was higher than is cases where it was not helpful. The rate of adverse events related to 5-ALA was negligible, especially new postoperative sequelae. 5-ALA could play a role in resection of pediatric brain tumors. However, further prospective clinical trials are needed.

Background The value of early postoperative 18F-FET-PET in patients with glioblastoma (GBM) is unclear. Five-aminolevulinic acid (5-ALA) is used for fluorescence-guided resections in these patients and previous data suggest that fluorescence and 18F-FET-PET both demarcate larger tumor volumes than gadolinium enhanced magnet resonance imaging (MRI). Objective To correlate fluorescence with enhancing volumes on postoperative MRI and 18F-FET-PET tumor volumes, and determine the value of postoperative 18F-FET-PET for predicting survival through observational study. Methods GBM patients underwent fluorescence-guided resection after administration of 5-ALA followed by early postoperative MRI and 18F-FET-PET for determination of residual tissue volumes. All patients were treated with standard temozolomide radiochemotherapy and monitored for progression-free and overall survival (PFS, OS). Results A total of 31 patients were included. For functional reasons, residual 5-ALA derived fluorescent tissue was left unresected in 18 patients with a median 18F-FET-PET volume of 17.82 cm3 (interquartile range 6.50-29.19). In patients without residual fluorescence, median 18F-FET-PET volume was 1.20 cm3 (interquartile range 0.87-5.50) and complete resection of gadolinium enhancing tumor was observed in 100% of patients. A 18F-FET-PET volume of above 4.3 cm3 was associated with worse OS (logrank P-value ≤ .05), also in patients with no residual contrast enhancing tumor on MRI. More patients in whom fluorescencing tissue had been removed completely had postoperative 18F-FET-PET tumor volumes below 4.3 cm3. Conclusion Postoperative 18F-FET-PET volumes predict OS and PFS. Resection of 5-ALA derived fluorescence beyond gadolinium enhancing tumor tissue leads to lower postoperative 18F-FET-PET tumor volumes and improved OS and PFS without additional deficits.

OBJECTIVERecent efforts to improve visualization of 5-aminolevulinic acid (5-ALA)–induced protoporphyrin IX (PPIX) fluorescence resulted in a dual-labeling technique, combining it with fluorescein sodium in a prototype setup. Fluorescein identifies regions with blood-brain barrier breakdown in gliomas. However, normally perfused and edematous brain fluoresces unselectively, with strong background enhancement. The aim of this study was to test the feasibility of a novel, integrated filter combination using porphyrins for selective tumor identification and fluorescein for background enhancement.METHODSA microscope with a novel built-in filter system (YB 475) for visualizing both fluorescein and 5-ALA–induced porphyrins was used. Resection limits were identified with the conventional BLUE 400 filter system. Six patients harboring contrast ring-enhancing lesions were analyzed.RESULTSThe complete surgical field could now be illuminated. Fluorescein was helpful for improving background visualization, and enhancing dura, edematous tissue, and cortex. Overlapping regions with both fluorophores harbored merged orange fluorescence. PPIX fluorescence was better visualized, even in areas beyond a normal working distance of approximately 25 cm, where the BLUE 400 filters recognized no or weak fluorescence.CONCLUSIONSThe novel filter system improved general tissue brightness and background visualization, enhancing fluorescence-guided tumor resection. Furthermore, it appears promising from a scientific perspective, enabling the simultaneous and direct observation of areas with blood-brain barrier breakdown and PPIX fluorescence.

BACKGROUND Lack of physical activity in the general population is one of the biggest health challenges we face. For rheumatology patients, and other patients with chronic disease, exercise is an essential part of disease management. However, very few patients exercise effectively.One of the aspirations of the London 2012 Olympic/Paralympic Games was to catalyze people into long-term physical activity. METHODS We surveyed our rheumatology patients at 3 high-profile times in the year after the Olympics. RESULTS Two hundred fifty-three patients were enrolled within the study; the largest diagnosis subgroup being rheumatoid arthritis (36%). Ninety-five percent of our patients regard exercise as beneficial; 36% still think it does harm. Most common barriers to exercise were pain (53%), tiredness (44%), and lack of time (36%). Forty-five percent exercise daily, mostly just walking. Twnety-seven patients (16%) were motivated by the 2012 Olympic and Paralympic Games toward physical activity. They were mostly motivated by athletics' individual stories (67%), taking part in a big sports festival (11%) and demonstration of top sporting levels (4%). Eighteen patients in total (7%) increased their amount of exercise in response to the London 2012 Olympic and Paralympic Games. There was no difference between patient diagnostic groups. CONCLUSIONS Only a small minority of patients increased their amount of exercise in response to the 2012 Olympic and Paralympic Games. The message about the importance of physical exercise to health needs to be clear, unambiguous, and consistent, because a significant number of patients still think that physical activity does harm. Big sporting events such as the London 2012 Olympic and Paralympic Games can be used as an opportunity to remind patients that physical activity does good and is not harmful. Athletes' individual stories could be used in future as part of a strategy to encourage exercise for all patients.

History: After the initiation of skills-labs in Marburg and Goettingen the peer-teaching students of both institutions saw a need for communication and cooperation. The primary goal of these ’skills-lab workshops’ was the exchange of already existing ideas for extracurricular peer-teaching, the development of new tutorials and long-term cooperation between the institutions. Methods: In January of 2010 the 1st ’skills-lab workshop’ Marburg-Goettingen was held at the ‘Marburg’s Interdisciplinary skills-lab’ (Maris, since 10/2008). The 2nd workshop was held at the ‘Student’s trainings center of medical practice and simulation’ (STÄPS, since 10/2009) in Goettingen in October of 2010. Results and conclusion: Especially younger skills-labs can profit from an exchange with a more established Institution. Cooperations like these are the foundation for future exchange of ideas for new peer-teachings and the continuous improvement or a transfer of existing peer-teachings for skills-labs. We recommend bilateral exchanges like this to other and especially to new skills-labs.

BACKGROUND Surgical resection is the therapy of choice in head and neck paraganglioma. However, surgery is associated with significant morbidity depending on tumor size and localization. In case of progressive residual or recurrent disease, new and less aggressive therapeutic options are warranted. Somatostatin receptor (SSTR) targeted therapies pose a promising alternative, as SSTRs are upregulated in paragangliomas. Only few studies provide evidence on efficacy of 177Lu-DOTATATE therapy in these patients. The aim of this study was to evaluate the efficacy of peptide receptor radiotherapy (PPRT) with 177Lu-DOTATATE for head and neck paragangliomas. METHODS A total of seven consecutive patients (mean age: 60 years, range: 14–84) with progressive head and neck paragangliomas (3 carotid body tumors, 4 jugulotympanic paragangliomas), treated with PRRT using 177Lu-DOTATATE, were included in this retrospective analysis. Therapy response was assessed by interim and post-therapy 68Ga-DOTATATE-PET-CT and MRI according to morphological and SSTR imaging parameters. Therapeutic uptake was classified on177Lu-DOTATATE scintigraphies 48h p.i. according to the Krenning scale. Longer-term clinical and imaging-based outcome were evaluated. RESULTS Patients received a median of 4 cycles (range: 3 to 5) of PRRT with 177Lu-DOTATATE (mean injected dose 7.3 GBq). Interim and post-therapy staging showed at least stable disease in all patients. Tumor uptake in 48h p.i. 177Lu-scintigraphies was moderate to high in all patients (Krenning scale; median: 3; range: 2–4). Furthermore, none of the patients showed progressive disease during the median follow-up time of 28 months (range: 6–37 months). CONCLUSION SSTR targeted therapy using 177Lu-DOTATATE shows promising efficacy and may lead to long lasting stable disease.