p16 Immunohistochemistry as a Screening Tool for Homozygous CDKN2A Deletions in CNS Tumors

The 2021 World Health Organization classification of tumors of the central nervous system emphasizes the significance of molecular parameters for an integrated diagnosis. Homozygous deletion of cyclin-dependent kinase inhibitor 2a (CDKN2A) has been associated with an adverse prognosis in IDH -mutant gliomas, supratentorial ependymomas, meningiomas, and MPNST. In this study, we examined the value of p16 protein immunohistochemistry as a rapid and cost-effective screening tool for a homozygous CDKN2A deletion. Genetic analyses for CDKN2A in 30 pleomorphic xanthoastrocytomas, 32 IDH -wild-type high-grade gliomas, 40 supratentorial ependymomas with ZFTA-RELA gene fusion, 21 IDH-mutant astrocytomas, and 24 meningiomas were performed mainly by a molecular inversion probe assay, a high-resolution, quantitative technology for the assessment of chromosomal copy number alterations. Immunohistochemistry for p16 proved to have a high positive predictive value (range 90% to 100%) and an overall low negative predictive value (range 22% to 93%) for a homozygous CDKN2A deletion. In a setting where molecular testing is limited for cost and time reasons, p16 immunohistochemistry serves as a useful and rapid screening tool for identifying cases that should be subjected to further molecular testing for CDKN2A deletions.

Ependymoma from Benign to Highly Aggressive Diseases: A Review

Ependymomas comprise biologically distinct tumor types with respect to age distribution, (epi)genetics, localization, and prognosis. Multimodal risk-stratification, including histopathological and molecular features, is essential in these biologically defined tumor types. Gross total resection (GTR), achieved with intraoperative monitoring and neuronavigation, and if necessary, second-look surgery, is the most effective treatment. Adjuvant radiation therapy is mandatory in high-risk tumors and in case of residual tumor. There is yet growing evidence that some ependymal tumors may be cured by surgery alone. To date, the role of chemotherapy is unclear and subject of current studies.Even though standard therapy can achieve reasonable survival rates for the majority of ependymoma patients, long-term follow-up still reveals a high probability of relapse in certain biological entities.With increasing knowledge of biologically distinct tumor types, risk-adapted adjuvant therapy gains importance. Beyond initial tumor control, and avoidance of therapy-induced morbidity for low-risk patients, intensified treatment for high-risk patients comprises another challenge. With identification of specific risk features regarding molecular alterations, targeted therapy may represent an option for individualized treatment modalities in the future.

Radiomics for the non-invasive prediction of PD-L1 expression in patients with brain metastases secondary to non-small cell lung cancer

BACKGROUND

The expression level of the programmed cell death ligand 1 (PD-L1) appears to be a predictor for response to immunotherapy using checkpoint inhibitors in patients with non-small cell lung cancer (NSCLC). As differences in terms of PD-L1 expression levels in the extracranial primary tumor and the brain metastases may occur, a reliable method for the non-invasive assessment of the intracranial PD-L1 expression is, therefore of clinical value. Here, we evaluated the potential of radiomics for a non-invasive prediction of PD-L1 expression in patients with brain metastases secondary to NSCLC.

PATIENTS AND METHODS

Fifty-three NSCLC patients with brain metastases from two academic neuro-oncological centers (group 1, n = 36 patients; group 2, n = 17 patients) underwent tumor resection with a subsequent immunohistochemical evaluation of the PD-L1 expression. Brain metastases were manually segmented on preoperative T1-weighted contrast-enhanced MRI. Group 1 was used for model training and validation, group 2 for model testing. After image pre-processing and radiomics feature extraction, a test-retest analysis was performed to identify robust features prior to feature selection. The radiomics model was trained and validated using random stratified cross-validation. Finally, the best-performing radiomics model was applied to the test data. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

An intracranial PD-L1 expression (i.e., staining of at least 1% or more of tumor cells) was present in 18 of 36 patients (50%) in group 1, and 7 of 17 patients (41%) in group 2. Univariate analysis identified the contrast-enhancing tumor volume as a significant predictor for PD-L1 expression (area under the ROC curve (AUC), 0.77). A random forest classifier using a four-parameter radiomics signature, including tumor volume, yielded an AUC of 0.83 ± 0.18 in the training data (group 1), and an AUC of 0.84 in the external test data (group 2).

CONCLUSION

The developed radiomics classifiers allows for a non-invasive assessment of the intracranial PD-L1 expression in patients with brain metastases secondary to NSCLC with high accuracy.

Angiographic characteristics associated with rupture of small intracranial aneurysms

OBJECTIVE

Contrary to previous assumptions, there is increasing evidence that small intracranial aneurysms carry a relevant risk of rupture. The aim of this study was to identify angiographic characteristics of small ruptured aneurysms ≤7 mm and to evaluate their significance for clinical decision making.

METHODS

A total of 385 patients with 149 unruptured and 236 ruptured intracranial aneurysms were retrospectively compared. Two- and three-dimensional digital subtraction angiography was used to determine aneurysm location, various size parameters, angulations, and morphology, as well as parent artery diameter.

RESULTS

Aneurysms of the anterior communicating artery, the posterior inferior cerebellar artery and the internal carotid artery terminus had a significantly increased prevalence among ruptured aneurysms. Ruptured aneurysms were characterized by a significantly larger aneurysm height (area-under-the curve [AUC] 0.60, p<0.01) and inclination angle (AUC 0.61, p=0.02) in addition to a smaller dome (AUC 0.44, p=0.02) and neck width (AUC 0.38, p<0.01). Calculation of size ratios increases the predictive value for aneurysm rupture, with AUC-values of 0.77 for aspect ratio (p<0.01) and 0.76 for size ratio (p<0.01). Aneurysm morphology was not a significant factor after multivariable adjustment (p=0.92). Arterial hypertension was the only clinical risk factor significantly associated with rupture (p<0.01).

CONCLUSIONS

Of the numerous factors associated with aneurysm rupture, we propose aneurysmal location, aspect ratio (cut-off: 1.5), and inclination angle as the most important morphological factors for assessing the rupture risk of small aneurysms because these factors have high AUC values and are robust to changes after rupture.

SURG-19. PROGNOSTIC VALIDATION OF A NEW CLASSIFICATION SYSTEM FOR EXTENT OF RESECTION IN GLIOBLASTOMA: A REPORT OF THE RANO RESECT GROUP

BACKGROUND

Terminology to describe extent of resection in glioblastoma is inconsistent across clinical trials. A surgical classification system was previously proposed based upon residual contrast-enhancing (CE) tumor. We aimed to (I) explore the prognostic utility of the classification system and (II) define how much removed non-CE tumor translates into a survival benefit.

METHODS

The international RANO resect group retrospectively searched the databases from seven neuro-oncological centers in the USA and Europe for patients with newly diagnosed glioblastoma per WHO 2021 classification. Clinical and volumetric information from pre- and post-operative MRI were collected.

RESULTS

We collected 1021 patients with newly diagnosed glioblastoma, including 1008 IDHwt patients. 744 IDHwt glioblastomas were treated with radiochemotherapy per EORTC 26981/22981 (TMZ/RT→TMZ) following surgery. Among such homogenously treated patients, lower absolute residual tumor volumes (in cm3) were favorably associated with outcome: patients with ‘maximal CE resection’ (class 2) had superior outcome compared to patients with ‘submaximal CE resection’ (class 3) or ‘biopsy’ (class 4) (median OS: 19 versus 15 versus 10 months; p=0.001). Extensive resection of non-CE tumor (≤ 5 cm3 residual non-CE tumor) provided an additional survival benefit in patients with complete CE resection, thus defining class 1 (‘supramaximal CE resection’) (median OS: 24 versus 19 months; p=0.008). The prognostic value of the resection classes was retained on multivariate analysis when adjusting for molecular and clinical markers including MGMT promotor status. Relative tumor reduction (in percentage) was not prognostic for outcome on multivariate analysis, and inter-rater agreement for CE and non-CE tumor on post-operative MRI was sufficient.

CONCLUSION

The proposed “RANO categories for extent of resection in glioblastoma” are highly prognostic and may serve for stratification of clinical trials. Removal of non-CE tumor beyond the CE tumor borders translates into additional survival benefit, providing a rationale to explicitly denominate such a ‘supramaximal CE resection’.

P11.35.B The clinical course of long-term survivors after the diagnosis of brain metastasis

Background

To asses demographic and clinical parameters, treatment, and course of disease in patients surviving longer ≥ 5 years after the diagnosis of brain metastasis (BM).

Material and Methods

We retrospectively identified patients who were treated for BM and survived ≥ 5 years after initial BM diagnosis. We analysed and described clinical and treatment related parameters with respect to histology, time to occurrence and systemic/ BM-specific treatment.

Results

We included 48 patients with a mean age of 55 years (range 33-81, SD 12) at diagnosis of primary tumor and 58 (range 41-84, SD 20) at initial BM diagnosis. Histology was non-small-cell lung cancer in 18 (37.5%), melanoma in 14 (29.2%), breast cancer in 11 (22.9%), renal carcinoma in 2 (4.2%), and small-cell lung cancer, cancer of unknown primary and gastrointestinal cancer in one case each (2.1%). Treatment for primary tumor included resection (83.3%), chemotherapy (43.8%), radiation (33.3%), interferon therapy (18.8%), and immuno-/targeted therapy (25%). Most patients received a combination of latter. The mean interval between primary tumor and BM diagnosis was 36 months (range -2 to 277; SD 57). At the time of BM diagnosis, 50% of patients presented with systemically stable disease, 66.7% showed BM related symptoms, 92% showed a KPS ≥70. Most patients had 1 BM (72.9%), while 20.9% had 2-3 and 6.3% &gt;3. Initial treatment for BM comprised resection (60.4%), stereotactic radiosurgery (27.2%), whole-brain-radiation therapy (8.4%), and interstitial brachytherapy (4.2%). Approximately half of the patients (52.1%) suffered from ≥1 BM relapse at initial treatment site. At the time of the analysis, 13 (27.1%) patients had died; cause of death was mostly unknown, in two patients each, systemic/cerebral cause was confirmed. The mean overall survival (OS) was 131 months (range 64-344, SD 68) and 95 (range 60-246, SD 36) after diagnosis of primary tumor and BM, respectively. All patients suffering from melanoma who had received interferon therapy (n=8) survived. Neither systemic status at BM diagnosis nor the administration of novel treatment agents or chemotherapy after BM diagnosis showed an impact on OS (p=0.642, p=0.177 and p=0.628, respectively). Further survival analysis was omitted due to subgroup sizes.

Conclusion

Despite the usually fatal course after BM development, some patients show long-term survival. Whether specific genetic parameters have a particular impact in this subgroup of patients, warrants further investigation.

Imaging of the extracranial internal carotid artery in acute ischemic stroke: assessment of stenosis, plaques, and image quality using relaxation-enhanced angiography without contrast and triggering (REACT)

BACKGROUND

In stroke magnetic resonance imaging (MRI), contrast-enhanced magnetic resonance angiography (CE-MRA) is the clinical standard to depict extracranial arteries but native MRA techniques are of increased interest to facilitate clinical practice. The purpose of this study was to assess the detection of extracranial internal carotid artery (ICA) stenosis and plaques as well as the image quality of cervical carotid arteries between a novel flow-independent relaxation-enhanced angiography without contrast and triggering (REACT) sequence and CE-MRA in acute ischemic stroke (AIS).

METHODS

In this retrospective, single-center study, 105 consecutive patients (65.27±18.74 years, 63 males) were included, who received a standard stroke protocol at 3T in clinical routine including Compressed SENSE (CS) accelerated (factor 4) 3D isotropic REACT (fixed scan time: 02:46 min) and CS accelerated (factor 6) 3D isotropic CE-MRA. Three radiologists independently assessed scans for the presence of extracranial ICA stenosis and plaques (including hyper-/hypointense signal) with concomitant diagnostic confidence using 3-point scales (3= excellent). Vessel quality, artifacts, and image noise of extracranial carotid arteries were subjectively scored on 5-point scales (5= excellent/none). Wilcoxon tests were used for statistical comparison.

RESULTS

Considering CE-MRA as the standard of reference, REACT provided a sensitivity of 89.8% and specificity of 95.2% for any and of 93.5% and 95.8% for clinically relevant (≥50%) extracranial ICA stenosis and yielded a to CE-MRA comparable diagnostic confidence [mean ± standard deviation (SD), median (interquartile range): 2.8±0.5, 3 (3-3) vs. 2.7±0.5, 3 (2-3), P=0.03]. Using REACT, readers detected more plaques overall (n=57.3 vs. 47.7, P<0.001) and plaques of hyperintense signal (n=12.3 vs. 5.7, P=0.02) with higher diagnostic confidence [2.8±0.5, 3 (3-3) vs. 2.6±0.7, 3 (2-3), P<0.001] than CE-MRA. After analyzing a total of 1,260 segments, the vessel quality of all segments combined [4.61±0.66 vs. 4.58±0.68, 5 (4-5) vs. 5 (4-5), P=0.0299] and artifacts [4.51±0.70 vs. 4.44±0.73, 5 (4-5) vs. 5 (4-5), P>0.05] were comparable between the sequences with REACT showing a lower image noise [4.43±0.67 vs. 4.25±0.71, 5 (4-5) vs. 4 (4-5), P<0.001].

CONCLUSIONS

Without the use of gadolinium-based contrast agents or triggering, REACT provides a high sensitivity and specificity for extracranial ICA stenosis and a potential improved depiction of adjacent plaques while yielding to CE-MRA comparable vessel quality in a large patient cohort with AIS.

ETMR-04. Embryonal tumor with multi-layered rosettes (ETMR) located in the brainstem: a case report on clinical decision-making and a multimodal, interdisciplinary treatment approach including interstitial brachytherapy

OBJECTIVE: Embryonal tumors with multi-layered rosettes (ETMR) (CNS WHO grade 4) comprise a rare and malignant tumor type affecting predominantly infants below 3 years of age. The treatment consists of maximal safe surgical resection, irradiation, and intensive medulloblastoma type chemotherapy. Despite aggressive treatment, the prognosis of these patients remains poor, especially for brainstem tumors. We present the case of a male infant diagnosed with a brainstem ETMR, successfully treated with an interdisciplinary multimodal approach, including stereotactic interstitial brachytherapy. RESULTS: A 19 month old boy first presented with hemiparesis, intermittent bradycardia and reduced consciousness. Initial imaging showed a brainstem lesion with characteristic features of a diffuse intrinsic pontine glioma (DIPG). We performed stereotactic biopsy to confirm the diagnosis and initiated temozolomide treatment. While the pathology result was still pending, the boy’s clinical condition deteriorated to a soporic state with stretch synergisms. By emergency open surgery, partial resection was achieved. Eventually, the patient recovered rapidly. After the diagnosis of ETMR was established, medulloblastoma type chemotherapy (systemic carboplatin/etoposide; intrathecal methotrexate) was administered. After two cycles, the patient showed only residual right-sided hemiparesis. However, imaging demonstrated only a minimal reduction of the tumor size. Therefore, stereotactic interstitial brachytherapy using 125iodine seeds and subsequent high-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) was performed and overall tolerated well. After two months of brachytherapy and two additional cycles of chemotherapy, the MRI showed ≥ 50% reduction in tumor volume and no neurological deficit can be clinically detected. CONCLUSION: This case indicates that stereotactic interstitial brachytherapy during intensive systemic chemotherapy is feasible. It may provide a suitable treatment for malignant infant brain tumors. Furthermore, it shows that paediatric patients are capable of recovery even after devastating neurological symptoms. Lastly, it emphasizes the importance of multidisciplinary and multimodal treatment for rare diseases.

Essential Management of Pediatric Brain Tumors

Brain tumors are the most common solid tumors in children and are associated with high mortality. The most common childhood brain tumors are grouped as low-grade gliomas (LGG), high grade gliomas (HGG), ependymomas, and embryonal tumors, according to the World Health Organization (WHO). Advances in molecular genetics have led to a shift from pure histopathological diagnosis to integrated diagnosis. For the first time, these new criteria were included in the WHO classification published in 2016 and has been further updated in the 2021 edition. Integrated diagnosis is based on molecular genomic similarities of the tumor subclasses, and it can better explain the differences in clinical courses of previously histopathologically identical entities. Important advances have also been made in pediatric neuro-oncology. A growing understanding of the molecular-genetic background of tumorigenesis has improved the diagnostic accuracy. Re-stratification of treatment protocols and the development of targeted therapies will significantly affect overall survival and quality of life. For some pediatric tumors, these advances have significantly improved therapeutic management and prognosis in certain tumor subgroups. Some therapeutic approaches also have serious long-term consequences. Therefore, optimized treatments are greatly needed. Here, we discuss the importance of multidisciplinary collaboration and the role of (pediatric) neurosurgery by briefly describing the most common childhood brain tumors and their currently recognized molecular subgroups.

Recurrent brain metastases: the role of resection of in a comprehensive multidisciplinary treatment setting

Background

Treatment decision for recurrent symptomatic brain metastases (BM) is challenging with scarce data regarding surgical resection. We therefore evaluated the efficacy of surgery for pretreated, recurrent BM in a comprehensive multidisciplinary treatment setting.

Methods

In a retrospective single center study, patients were analyzed, who underwent surgical resection of recurrent BM between 2007 and 2019. Intracranial event-free survival (EFS) and overall survival (OS) were evaluated by Kaplan-Maier and Cox regression analysis.

Results

We included 107 patients with different primary tumor entities and individual previous treatment for BM. Primary tumors comprised non-small cell lung cancer (NSCLC) (37.4%), breast cancer (19.6%), melanoma (13.1%), gastro-intestinal cancer (10.3%) and other, rare entities (19.6%). The number of previous treatments of BM ranged from one to four; the adjuvant treatment modalities comprised: none, focal or whole brain radiotherapy, brachytherapy and radiosurgery. The median pre-operative Karnofsky Performance Score (KPS) was 70% (range 40–100) and improved to 80% (range 0-100) after surgery. The complication rate was 26.2% and two patients died during the perioperative period. Sixty-seven (62.6%) patients received postoperative local radio-oncologic and/or systemic therapy. Median postoperative EFS and OS were 7.1 (95%CI 5.8–8.2) and 11.1 (95%CI 8.4–13.6) months, respectively. The clinical status (postoperative KPS ≥ 70 (HR 0.27 95%CI 0.16–0.46; p < 0.001) remained the only independent factor for survival in multivariate analysis.

Conclusions

Surgical resection of recurrent BM may improve the clinical status and thus OS but is associated with a high complication rate; therefore a very careful patient selection is crucial.

Radiomics for the noninvasive prediction of the BRAF mutation status in patients with melanoma brain metastases

BACKGROUND

The BRAF V600E mutation is present in approximately 50% of patients with melanoma brain metastases and an important prerequisite for response to targeted therapies, particularly BRAF inhibitors. As heterogeneity in terms of BRAF mutation status may occur in melanoma patients, a wild-type extracranial primary tumor does not necessarily rule out a targetable mutation in brain metastases using BRAF inhibitors. We evaluated the potential of MRI radiomics for a noninvasive prediction of the intracranial BRAF mutation status.

METHODS

Fifty-nine patients with melanoma brain metastases from two university brain tumor centers (group 1, 45 patients; group 2, 14 patients) underwent tumor resection with subsequent genetic analysis of the intracranial BRAF mutation status. Preoperative contrast-enhanced MRI was manually segmented and analyzed. Group 1 was used for model training and validation, group 2 for model testing. After radiomics feature extraction, a test-retest analysis was performed to identify robust features prior to feature selection. Finally, the best performing radiomics model was applied to the test data. Diagnostic performances were evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

Twenty-two of 45 patients (49%) in group 1, and 8 of 14 patients (57%) in group 2 had an intracranial BRAF V600E mutation. A linear support vector machine classifier using a six-parameter radiomics signature yielded an area under the ROC curve of 0.92 (sensitivity, 83%; specificity, 88%) in the test data.

CONCLUSIONS

The developed radiomics classifier allows a noninvasive prediction of the intracranial BRAF V600E mutation status in patients with melanoma brain metastases with high diagnostic performance.

Resection of symptomatic non-small cell lung cancer brain metastasis in the setting of multiple brain metastases

OBJECTIVE

Current guidelines primarily suggest resection of brain metastases (BMs) in patients with limited lesions. With a growing number of highly effective local and systemic treatment options, this view may be challenged. The purpose of this study was to evaluate the role of metastasectomy, disregarding BM count, in a comprehensive treatment setting.

METHODS

In this monocentric retrospective analysis, the authors included patients who underwent resection for at least 1 BM and collected demographic, clinical, and tumor-associated parameters. Prognostic factors for local control and overall survival (OS) were analyzed with the log-rank test and Cox proportional hazards analysis.

RESULTS

The authors analyzed 216 patients. One hundred twenty-nine (59.7%) patients were diagnosed with a single/solitary BM, whereas 64 (29.6%) patients had 2-3 BMs and the remaining 23 (10.6%) had more than 3 BMs. With resection of symptomatic BMs, a significant improvement in Karnofsky Performance Scale (KPS) was achieved (p < 0.001), thereby enabling adjuvant radiotherapy for 199 (92.1%) patients and systemic treatment for 119 (55.1%) patients. During follow-up, 83 (38.4%) patients experienced local recurrence. BM count did not significantly influence local control rates. By the time of analysis, 120 (55.6%) patients had died; the leading cause of death was systemic tumor progression. The mean (range) OS after surgery was 12.7 (0-88) months. In univariate analysis, the BM count did not influence OS (p = 0.844), but age < 65 years (p = 0.007), preoperative and postoperative KPS ≥ 70 (p = 0.002 and p = 0.005, respectively), systemic metastases other than BM (p = 0.004), adjuvant radiation therapy (p < 0.001), and adjuvant systemic treatment (p < 0.001) were prognostic factors. In regression analysis, the presence of extracranial metastases (HR 2.30, 95% CI 1.53-3.48, p < 0.001), adjuvant radiation therapy (HR 0.97, 95% CI 0.23-0.86, p = 0.016), and adjuvant systemic treatment (HR 0.37, 95% CI 0.25-0.55, p < 0.001) remained as independent factors for survival.

CONCLUSIONS

Surgery for symptomatic BM from non-small cell lung cancer may be indicated even for patients with multiple lesions in order to alleviate their neurological symptoms and to consequently facilitate further treatment.

SURG-04. Surgical resection of symptomatic brain metastasis in patients with non-small cell lung cancer irrespective from lesion count

Background and Purpose

Current guidelines primarily suggest the resection in case of a limited number of brain metastases (BM). With an increasing number of local and systemic treatment options this approach needs reconsideration. Therefore, we aimed to evaluate the role of metastectomy in patients with non-small cell lung cancer (NSCLC) treated in a comprehensive setting disregarding lesion count.

Patients and Methods

In this monocentric retrospective analysis, patients receiving surgery for 1–3 BM with available demographic, clinical, and tumor-associated parameters were included. Prognostic factors for local control (LC) and overall survival (OS) were analyzed by Log rank test and Cox proportional hazards.

Results

Two-hundred-sixteen patients were included: 129 (59.7%) with single/solitary, 64 (29.6%) with 2–3, and 23 (10.6%) with more than three BM. Resection of the symptomatic BM(s) improved the patients’ Karnofsky performance index (KPI) significantly (p<0.001), enabling adjuvant radiotherapy in 199 (92.1%) and systemic treatment in 119 (55.1%) patients.

After a mean radiological follow-up of eight (1–79) months, LC was observed in 83 (38.4%) patients and was not significantly influenced by BM count (p=0.064). After a mean OS after surgery of 12.7 (0–88) months, 120 (55.6%) patients had died.

In univariate analysis, BM count showed no impact on OS (p=0.844), while age ≥/< 65 years (p=0.007), pre- and postoperative KPI ≥70 (p=0.002 and p=0.005, respectively), extra-cranial metastases (p=0.004), adjuvant radiation therapy (p<0.001), and adjuvant systemic treatment (p<0.001) did. In regression analysis the presence of extra-cranial metastases (HR 2.30 95%CI 1.53–3.48; p<0.001), adjuvant radiation therapy (HR 0.97 95%CI 0.23–0.86; p=0.016), and adjuvant systemic treatment (HR 0.37 95%CI 0.25–0.55; p<0.001) remained independent factors for survival.

Conclusions

The indication for resection of symptomatic BM in patients with NSCLC is justified even in case of multiple lesions to alleviate their neurological symptoms and to enable further treatment.

MLTI-03. The relevance of the count of brain metastases for treatment and outcome in NSCLC

Background and Purpose

While data reporting the number of brain metastasis as a prognostic factor for patients with NSCLC, we analyzed whether the prognostic importance of the mere count of brain metastasis in a modern, multimodal treatment setting.

Patients and Methods

We retrospectively analyzed patients treated for BM from non-small lung cancer between 2010 and 2020. Demographics, baseline characteristics, and tumor-associated parameters were retrieved from an electronic database. Prognostic factors for local cerebral control and survival were identified using the log-rank test and Cox regression analysis.

Results

We included 343 consecutive patients (male n=187, female n=156; median age 61 years). Histological subtypes were adenocarcinoma (n=283), squamous-cell carcinoma (n=42) and neuroendocrine carcinoma (n=18). The median number of BM was one (range 1–20). Single (n = 189), oligo (n=110) and multiple BM (n=44) showed in total a median follow up of 10 months (minimum 1, maximum 142). Treatment comprised surgical resection (n=218) with radiotherapy, stereotactic radiosurgery (n=125) and adjuvant systemic therapy (n=203). The median local cerebral control was 11 months (95%CI 8.5 – 13.5) and the median overall survival was 16 months (95%CI 12.8 – 19.2). The number of BM did not influence local control and overall survival rates (p = 0.234 and p = 0.210, respectively). Controlled systemic disease (HR 0.42; 95% CI 0.2284–0.633; p<0.0001), clinical status (Karnofsky Performance Score > 70; HR 0.41; 95% CI 0.265–0.661; p<0.0001) and adjuvant systemic therapy (HR 0.38; 95% CI 0.279–0.530; p<0.0001) were independent prognostic factors for survival.

Conclusions

The mere number of brain metastases is not a prognostic factor for survival and local cerebral control in a multimodal treatment setting.

Frequency of actionable molecular drivers in lung cancer patients with precocious brain metastases

Brain metastases frequently occur during the course of disease in patients suffering from lung cancer. Occasionally, neurological symptoms caused by brain metastases (BM) might represent the first sign of systemic tumor disease (so called precocious metastases), leading to the detection of the primary lung tumor. The biological basis of precocious BM is largely unknown, and treatment options are not well established for this subgroup of patients. Therefore, we retrospectively analyzed 33 patients (24 non-small cell lung cancer (NSCLC)), 9 small cell lung cancer (SCLC)) presenting with precocious BM focusing on molecular alterations potentially relevant for the tumor's biology and treatment. We found five FGFR1 amplifications (4 adenocarcinoma, 1 SCLC) among 31 analyzed patients (16.1%), eight MET amplifications among 30 analyzed tumors (7 NSCLC, 1 SCLC; 26.7%), three EGFR mutations within 33 patients (all adenocarcinomas, 9.1%), and five KRAS mutations among 32 patients (all adenocarcinomas; 15.6%). No ALK, ROS1 or RET gene rearrangements were detected. Our findings suggest that patients with precocious BM of lung cancer harbor EGFR mutations, MET amplifications or FGFR1 amplifications as potential targeted treatment options.

Fully Automated MR Detection and Segmentation of Brain Metastases in Non-small Cell Lung Cancer Using Deep Learning

BACKGROUND

Non-small cell lung cancer (NSCLC) is the most common tumor entity spreading to the brain and up to 50% of patients develop brain metastases (BMs). Detection of BMs on MRI is challenging with an inherent risk of missed diagnosis.

PURPOSE

To train and evaluate a deep learning model (DLM) for fully automated detection and 3D segmentation of BMs in NSCLC on clinical routine MRI.

STUDY TYPE

Retrospective.

POPULATION

Ninety-eight NSCLC patients with 315 BMs on pretreatment MRI, divided into training (66 patients, 248 BMs) and independent test (17 patients, 67 BMs) and control (15 patients, 0 BMs) cohorts.

FIELD STRENGTH/SEQUENCE

T₁ -/T₂ -weighted, T₁ -weighted contrast-enhanced (T₁ CE; gradient-echo and spin-echo sequences), and FLAIR at 1.0, 1.5, and 3.0 T from various vendors and study centers.

ASSESSMENT

A 3D convolutional neural network (DeepMedic) was trained on the training cohort using 5-fold cross-validation and evaluated on the independent test and control sets. Three-dimensional voxel-wise manual segmentations of BMs by a neurosurgeon and a radiologist on T₁ CE served as the reference standard.

STATISTICAL TESTS

Sensitivity (recall) and false positive (FP) findings per scan, dice similarity coefficient (DSC) to compare the spatial overlap between manual and automated segmentations, Pearson's correlation coefficient (r) to evaluate the relationship between quantitative volumetric measurements of segmentations, and Wilcoxon rank-sum test to compare the volumes of BMs. A P value <0.05 was considered statistically significant.

RESULTS

In the test set, the DLM detected 57 of the 67 BMs (mean volume: 0.99 ± 4.24 cm³ ), resulting in a sensitivity of 85.1%, while FP findings of 1.5 per scan were observed. Missed BMs had a significantly smaller volume (0.05 ± 0.04 cm³ ) than detected BMs (0.96 ± 2.4 cm³ ). Compared with the reference standard, automated segmentations achieved a median DSC of 0.72 and a good volumetric correlation (r = 0.95). In the control set, 1.8 FPs/scan were observed.

DATA CONCLUSION

Deep learning provided a high detection sensitivity and good segmentation performance for BMs in NSCLC on heterogeneous scanner data while yielding a low number of FP findings. Level of Evidence 3 Technical Efficacy Stage 2.

Deep learning assistance increases the detection sensitivity of radiologists for secondary intracranial aneurysms in subarachnoid hemorrhage

Purpose

To evaluate whether a deep learning model (DLM) could increase the detection sensitivity of radiologists for intracranial aneurysms on CT angiography (CTA) in aneurysmal subarachnoid hemorrhage (aSAH).

Methods

Three different DLMs were trained on CTA datasets of 68 aSAH patients with 79 aneurysms with their outputs being combined applying ensemble learning (DLM-Ens). The DLM-Ens was evaluated on an independent test set of 104 aSAH patients with 126 aneuryms (mean volume 129.2 ± 185.4 mm³, 13.0% at the posterior circulation), which were determined by two radiologists and one neurosurgeon in consensus using CTA and digital subtraction angiography scans. CTA scans of the test set were then presented to three blinded radiologists (reader 1: 13, reader 2: 4, and reader 3: 3 years of experience in diagnostic neuroradiology), who assessed them individually for aneurysms. Detection sensitivities for aneurysms of the readers with and without the assistance of the DLM were compared.

Results

In the test set, the detection sensitivity of the DLM-Ens (85.7%) was comparable to the radiologists (reader 1: 91.2%, reader 2: 86.5%, and reader 3: 86.5%; Fleiss κ of 0.502). DLM-assistance significantly increased the detection sensitivity (reader 1: 97.6%, reader 2: 97.6%,and reader 3: 96.0%; overall P=.024; Fleiss κ of 0.878), especially for secondary aneurysms (88.2% of the additional aneurysms provided by the DLM).

Conclusion

Deep learning significantly improved the detection sensitivity of radiologists for aneurysms in aSAH, especially for secondary aneurysms. It therefore represents a valuable adjunct for physicians to establish an accurate diagnosis in order to optimize patient treatment.

The Debatable Benefit of Gross-Total Resection of Brain Metastases in a Comprehensive Treatment Setting

Simple Summary

In this monocentric retrospective analysis, the extent of resection of singular/solitary brain metastases has no impact on local recurrence and overall survival rates in patients receiving multidisciplinary adjuvant treatment. Since systemic disease progression is the leading cause of death, and an uncontrolled systemic disease status, along with adjuvant treatment, present independent predictors of overall survival, a comprehensive, multidisciplinary treatment concept is essential for patients with brain metastases.

Abstract

Background and Purpose: The value of gross-total surgical resection remains debatable in patients with brain metastases (BMs) as most patients succumb to systemic disease progression. In this study, we evaluated the impact of the extent of resection of singular/solitary BM on in-brain recurrence (iBR), focusing on local recurrence (LR) and overall survival (OS) in an interdisciplinary adjuvant treatment setting. Patients and Methods: In this monocentric retrospective analysis, we included patients receiving surgery of one BM and subsequent adjuvant treatment. A radiologist and a neurosurgeon determined in consensus the extent of resection based on magnetic resonance imaging. The OS was calculated using Kaplan–Meier estimates; prognostic factors for LR and OS were analysed by Log rank test and Cox proportional hazards. Results: We analyzed 197 patients. Gross-total resection was achieved in 123 (62.4%) patients. All patients were treated with adjuvant radiotherapy, and 130 (66.0%) received systemic treatment. Ninety-six (48.7%) patients showed iBR with an LR rate of 23.4%. LR was not significantly influenced by the extent of resection (p = 0.139) or any other parameter. The median OS after surgery was 18 (95%CI 12.5–23.5) months. In univariate analysis, the extent of resection did not influence OS (p = 0.6759), as opposed to adjuvant systemic treatment (p < 0.0001) and controlled systemic disease (p = 0.039). Systemic treatment and controlled disease status remained independent factors for OS (p < 0.0001 and p = 0.009, respectively). Conclusions: In this study, the extent of resection of BMs neither influenced the LR nor the OS of patients receiving interdisciplinary adjuvant treatment.

Timing of Development of Symptomatic Brain Metastases from Non-Small Cell Lung Cancer: Impact on Symptoms, Treatment, and Survival in the Era of Molecular Treatments

Simple Summary

In order to clarify whether an early development of brain metastases from non-small cell lung cancer represents a poor prognostic factor for further survival we analyzed 377 patients with brain metastases, treated by radiosurgery or surgery at two German institutions. Our results show that an early appearance of brain metastasis does not influence further survival in a comprehensive treatment setting.

Abstract

Objective: We attempted to analyze whether early presentation with brain metastases (BM) represents a poor prognostic factor in patients with non-small cell lung cancer (NSCLC), which should guide the treatment team towards less intensified therapy. Patients and methods: In a retrospective bi-centric analysis, we identified patients receiving surgical treatment for NSCLC BM. We collected demographic-, tumor-, and treatment-related parameters and analyzed their influence on further survival. Results: We included 377 patients. Development of BM was precocious in 99 (26.3%), synchronous in 152 (40.3%), and metachronous in 126 (33.4%) patients. The groups were comparable in terms of age (p = 0.76) and number of metastases (p = 0.11), and histology (p = 0.1); however, mutational status significantly differed (p = 0.002). The precocious group showed the worst clinical status as assessed by Karnofsky performance score (KPS) upon presentation (p < 0.0001). Resection followed by postoperative radiotherapy was the predominant treatment modality for precocious BM, while in syn- and metachronous BM surgical and radio-surgical treatment was balanced. Overall survival (OS) did not differ between the groups (p = 0.76). A good postoperative clinical status (KPS ≥ 70) and the application of any kind of adjuvant systemic therapy were independent predictive factors for OS. Conclusion: Early BM presentation was not associated with worse OS in NSCLC BM patients.

Surgical resection of symptomatic brain metastases improves the clinical status and facilitates further treatment

Background

Brain metastases (BM) frequently cause focal neurological deficits leading to a reduced Karnofsky performance score (KPS). Since KPS is routinely used to guide the choice of adjuvant therapy, we hypothesized that improving KPS by surgical resection may improve the chance for adjuvant treatment and ultimately result in better survival. We therefore analyzed the course of a large cohort undergoing resection of symptomatic brain metastases in the context of further treatment and clinical outcome.

Patients and methods

In a bi‐centric retrospective analysis we retrieved baseline, clinical, and treatment‐related parameters of patients operated on BM between 2010 and 2019. Survival was calculated using Kaplan‐Meier estimates; prognostic factors for survival were analyzed by Log‐rank test and Cox proportional hazards.

Results

We included 750 patients with a median age of 61 (19‐87) years. The functional status was significantly improved by surgical resection, with a median preoperative (KPS) of 80 (10‐100) increasing to 90 (0‐100) after surgery (P < .0001). Moreover, surgery improved the RTOG recursive partitioning analysis (RPA) class from III to I/II in 82 patients. Postoperative local radiotherapy and systemic treatment were associated with significantly longer survival (P < .0001 for each). Systemic treatment was provided significantly more frequently in patients with a fair postoperative clinical status (KPS ≥ 70; P < .0001). The postoperative clinical status, postoperative radiotherapy, systemic treatment, controlled systemic disease and < 4 BM were independent predictors for survival.

Conclusion

The resection of symptomatic BM may restore clinical status, so enhancing the likelihood of receiving adjuvant treatment, and therefore leading to improved overall survival.

Ependymomas in infancy: underlying genetic alterations, histological features, and clinical outcome

INTRODUCTION

Young age is an adverse prognostic factor in children with ependymomas. Treatment of these infants is challenging since beneficial therapeutic options are limited. As ependymomas are considered a biologically heterogeneous group, we aimed to characterize infant ependymomas with regard to their histological and genetic features.

MATERIALS AND METHODS

We analyzed 28 ependymomas occurring in children younger than 18 months at diagnosis enrolled into the HIT2000-E protocols with the aim to postpone irradiation until the age of 18 months if possible. All cases underwent neuropathological review, including immunohistochemical characterization. Genome-wide copy number alterations (CNA) were assessed by molecular inversion probe assays, and RELA and YAP1 fusions were detected by RT-PCR and sequencing.

RESULTS

All infant ependymomas were anaplastic (WHO grade III). Twenty-one (75%) cases were located in the posterior fossa. Gross total resection was accomplished in 12 (57%) of these cases. All posterior fossa tumors showed loss of H3-K27me³ characteristic of PFA ependymomas. CNA analysis showed a stable genome in all cases with lack of chromosome 1q gain, an adverse prognostic marker in PFA ependymomas of older children. However, after a median follow-up of 5.4 years, 15 (71%) relapsed, and 9 (43%) died. Seven ependymomas (25%) occurred in the supratentorial region. Gross total resection could be achieved in only two of these cases. Four tumors carried C11orf95-RELA fusions, and two cases had typical YAP1-MAMLD1 fusions (one case was not analyzable). The RELA-fused cases did not display CDKN2A loss as an adverse indicator of prognosis in this disease entity. Although three infants (43%) with supratentorial ependymomas relapsed, all patients survived (median follow-up, 8.0 years).

CONCLUSION

Infant ependymomas seem to fall into three biological entities, with supratentorial tumors carrying RELA or YAP fusions and PFA posterior fossa ependymomas. The latter showed a poor outcome even though chromosome 1q gain was absent.

Improved risk-stratification for posterior fossa ependymoma of childhood considering clinical, histological and genetic features - a retrospective analysis of the HIT ependymoma trial cohort

Introduction

Risk stratification of children with ependymomas of the posterior fossa in current therapeutic protocols is mainly based on clinical criteria. We aimed to identify independent outcome predictors for this disease entity by a systematic integrated analysis of clinical, histological and genetic information in a defined cohort of patients treated according to the German HIT protocols.

Methods

Tumor samples of 134 patients aged 0.2–15.9 years treated between 1999 and 2010 according to HIT protocols were analyzed for histological features including mitotic activity, necrosis and vascular proliferation and genomic alterations by SNP and molecular inversion probe analysis. Survival analysis was performed by Kaplan-Meier method with log rank test and multivariate Cox regression analysis.

Results

Residual tumor after surgery, chromosome 1q gain and structural genomic alterations were identified as predictors of significantly shorter event-free (EFS) and overall survival (OS). Furthermore, specific histological features including vascular proliferation, necrosis and high mitotic activity were predictive for shorter OS. Multivariate Cox regression revealed residual tumor, chromosome 1q gain and mitotic activity as independent predictors of both EFS and OS. Using these independent predictors of outcome, we were able to build a 3-tiered risk stratification model that separates patients with standard, intermediate and high risk, and which outperforms current stratification procedures.

Conclusion

The integration of defined clinical, histological and genetic parameters led to an improved risk-stratification model for posterior fossa ependymoma of childhood. After validation in independent cohorts this model may provide the basis for risk-adapted treatment of children with ependymomas of the posterior fossa.

Childhood supratentorial ependymomas with YAP1-MAMLD1 fusion: an entity with characteristic clinical, radiological, cytogenetic and histopathological features

Ependymoma with YAP1‐MAMLD1 fusion is a rare, recently described supratentorial neoplasm of childhood, with few cases published so far. We report on 15 pediatric patients with ependymomas carrying YAP1‐MAMLD1 fusions, with their characteristic histopathology, immunophenotype and molecular/cytogenetic, radiological and clinical features. The YAP1‐MAMLD1 fusion was documented by RT‐PCR/Sanger sequencing, and tumor genomes were studied by molecular inversion probe (MIP) analysis. Significant copy number alterations were identified by GISTIC (Genomic Identification of Significant Targets in Cancer) analysis. All cases showed similar histopathological features including areas of high cellularity, presence of perivascular pseudo‐rosettes, small to medium‐sized nuclei with characteristic granular chromatin and strikingly abundant cells with dot‐like cytoplasmic expression of epithelial membrane antigen. Eleven cases presented features of anaplasia, corresponding to WHO grade III. MRI showed large supratentorial multinodular tumors with cystic components, heterogeneous contrast enhancement, located in the ventricular or periventricular region. One of two variants of YAP1‐MAMLD1 fusions was detected in all cases. The MIP genome profiles showed balanced profiles, with focal alterations of the YAP1 locus at 11q22.1–11q21.2 (7/14), MAMLD1 locus (Xp28) (10/14) and losses of chromosome arm 22q (5/14). Most patients were female (13/15) and younger than 3 years at diagnosis (12/15; median age, 8.2 months). Apart from one patient who died during surgery, all patients are alive without evidence of disease progression after receiving different treatment protocols, three without postoperative further treatment (median follow‐up, 4.84 years). In this to date, largest series of ependymomas with YAP1‐MAMLD1 fusions we show that they harbor characteristic histopathological, cytogenetic and imaging features, occur mostly in young girls under 3 years and are associated with good outcome. Therefore, this genetically defined neoplasm should be considered a distinct disease entity. The diagnosis should be confirmed by demonstration of the specific fusion. Further studies on large collaborative series are warranted to confirm our findings.