Early postoperative magnet resonance tomography after resection of cerebral metastases

Epidemiology and palliative care of in-patient cerebral metastases cases in Germany

INTRODUCTION

Cerebral metastases (CM) are the most common intracranial neoplasms, significantly impacting patient quality-of-life. Despite advancements in diagnostics and therapeutics, the burden remains high. This study evaluates inpatient management, palliative care use, and mortality outcomes for CM patients in German hospitals in 2022.

METHODS

A cross-sectional analysis was conducted on 71,787 inpatient cases involving adult CM and leptomeningeal malignancies patients in German hospitals in 2022. Data submitted by hospitals according to §21 of the Hospital Remuneration Act were analyzed, focusing on demographic data, primary tumor types, treatment methods, participation in palliative care, and discharge outcomes.

RESULTS

Among the 71,787 cases, 53.4% were patients aged 65 years or older. Malignant lung tumors were present in 61.6% of cases, followed by breast malignancies (12%) and malignant melanoma and diffuse diffuse large B-cell lymphoma (each 6.4%). Specialized inpatient palliative care (SIPC) was provided in 14.8% (10,636 cases), with 85.2% not receiving such care. Hospital mortality was 13.1% (9413 cases), with 42.2% of these involving patients who received SIPC. Discharge outcomes included discharge home (72.7%), transfers to other hospitals (7.1%), rehabilitation facilities (0.4%), nursing facilities (2%), and hospices (2.4%).

CONCLUSION

Despite treatment advances, high mortality rates for CM patients persist, underscoring the need for palliative care integration and comprehensive training to enhance patient outcomes. Health care planning is a growing topic, our study establishes a benchmark for CM care in German hospitals, revealing a significant number of patients not receiving SIPC. This research can inform future healthcare strategies in neuro-oncology.

The role of surgery in recurrent local cerebral metastases: a multi-institutional retrospective analysis

BACKGROUND

Local recurrent brain metastases are defined as lesions that recur in the brain at the same site after a previous local therapy. In patients already submitted to surgery, a second operation may be potentially challenging due to scar formation, infiltration of cerebral vessels or eloquent brain areas and local effect of previous radiotherapy. The aim of this study is to retrospectively review the results and complications of a second surgical treatment in a series of local recurrent lesions and to review the literature on this topic.

METHODS

37 patients submitted to surgery for a local, histologically confirmed, recurrent brain metastases between 2000 and 2022 were retrospectively analyzed with respect to the following parameters: age, histology, anatomic location, time to recurrence, previous radiotherapy, size of recurrent tumors, preoperative and postoperative Karnofsky Performance Status (KPS) score, recursive partitioning analysis (RPA) class and graded prognostic assessment (GPA) score, surgery-related complications and the presence of further cerebral metastases. Overall survival (OS) was calculated using the Kaplan-Meier method. A multivariate Cox proportional hazard model was developed using stepwise regression (forwards selection) with predictive variables that were significant in the univariate analyses.

RESULTS

A significant improvement of post-operative KPS status was obtained after second surgery. At multivariate analysis better results in terms of OS were achieved in patients with a pre-operative KPS ≥ 70 and in patients who had received radiotherapy after the initial surgery. No significant postoperative complications related to previous treatments were observed.

CONCLUSIONS

Surgical resection of local recurrent brain metastases may improve patients ́ neurologic conditions allowing more time for systemic therapies to act with a low incidence of surgery-related morbidity and mortality. However, careful patient selection with a fair pre-operative clinical status seems mandatory to achieve the best post-operative results, since uniform treatment-paradigms cannot be established yet, due to the highly heterogeneous patient cohort.

Role of microsurgical tumor burden reduction in patients with breast cancer brain metastases considering molecular subtypes: a two-center volumetric survival analysis

BACKGROUND

Advancements in metastatic breast cancer (BC) treatment have enhanced overall survival (OS), leading to increased rates of brain metastases (BM). This study analyzes the association between microsurgical tumor reduction and OS in patients with BCBM, considering tumor molecular subtypes and perioperative treatment approaches.

METHODS

Retrospective analysis of surgically treated patients with BCBM from two tertiary brain tumor Swiss centers. The association of extent of resection (EOR), gross-total resection (GTR) achievement, and postoperative residual tumor volume (RV) with OS and intracranial progression-free survival (IC-PFS) was evaluated using Cox proportional hazard model.

RESULTS

101 patients were included in the final analysis, most patients (38%) exhibited HER2-/HR + BC molecular subtype, followed by HER2 + /HR + (25%), HER2-/HR- (21%), and HER2 + /HR- subtypes (13%). The majority received postoperative systemic treatment (75%) and radiotherapy (84%). Median OS and intracranial PFS were 22 and 8 months, respectively. The mean pre-surgery intracranial tumor volume was 26 cm3, reduced to 3 cm3 post-surgery. EOR, GTR achievement and RV were not significantly associated with OS or IC-PFS, but higher EOR and lower RV correlated with extended OS in patients without extracranial metastases. HER2-positive tumor status was associated with longer OS, extracranial metastases at BM diagnosis and symptomatic lesions with shorter OS and IC-PFS.

CONCLUSIONS

Our study found that BC molecular subtypes, extracranial disease status, and BM-related symptoms were associated with OS in surgically treated patients with BCBM. Additionally, while extensive resection to minimize residual tumor volume did not significantly affect OS across the entire cohort, it appeared beneficial for patients without extracranial metastases.

Brain metastases: Comparing clinical radiological differences in patients with lung and breast cancers treated with surgery

Purpose

Brain metastases (BMs) most frequently originate from the primary tumors of the lung and breast. Survival in patients with BM can improve if they are detected early. No studies attempt to consider all potential surgical predictive factors together by including clinical, radiological variables for their recognition.

Methods

The study aims to simultaneously analyze all clinical, radiologic, and surgical variables on a cohort of 314 patients with surgically-treated BMs to recognize the main features and differences between the two histotypes.

Results

The two groups consisted of 179 BM patients from lung cancer (Group A) and 135 patients from breast cancer (Group B). Analysis showed that BMs from breast carcinoma are more likely to appear in younger patients, tend to occur in the infratentorial site and are frequently found in patients who have other metastases outside of the brain (46 %, p = 0.05), particularly in bones. On the other hand, BMs from lung cancer often occur simultaneously with primitive diagnosis, are more commonly cystic, and have a larger edema volume. However, no differences were found in the extent of resection, postoperative complications or the presence of decreased postoperative performance status.

Conclusion

The data presented in this study reveal that while the two most prevalent forms of BM exhibit distinctions with respect to clinical onset, age, tumor location, presence of extra-cranial metastases, and lesion morphology from a strictly surgical standpoint, they are indistinguishable with regard to outcome, demonstrating comparable resection rates and a low risk of complications.

Cytoreduction of Residual Tumor Burden Is Decisive for Prolonged Survival in Patients with Recurrent Brain Metastases-Retrospective Analysis of 219 Patients

BACKGROUND

Despite advances in treatment for brain metastases (BMs), the prognosis for recurrent BMs remains poor and requires further research to advance clinical management and improve patient outcomes. In particular, data addressing the impact of tumor volume and surgical resection with regard to survival remain scarce.

METHODS

Adult patients with recurrent BMs between December 2007 and December 2022 were analyzed. A distinction was made between operated and non-operated patients, and the residual tumor burden (RTB) was determined by using (postoperative) MRI. Survival analysis was performed and RTB cutoff values were calculated using maximally selected log-rank statistics. In addition, further analyses on systemic tumor progression and (postoperative) tumor therapy were conducted.

RESULTS

In total, 219 patients were included in the analysis. Median age was 60 years (IQR 52-69). Median preoperative tumor burden was 2.4 cm3 (IQR 0.8-8.3), and postoperative tumor burden was 0.5 cm3 (IQR 0.0-2.9). A total of 95 patients (43.4%) underwent surgery, and complete cytoreduction was achieved in 55 (25.1%) patients. Median overall survival was 6 months (IQR 2-10). Cutoff RTB in all patients was 0.12 cm3, showing a significant difference (p = 0.00029) in overall survival (OS). Multivariate analysis showed preoperative KPSS (HR 0.983, 95% CI, 0.967-0.997, p = 0.015), postoperative tumor burden (HR 1.03, 95% CI 1.008-1.053, p = 0.007), and complete vs. incomplete resection (HR 0.629, 95% CI 0.420-0.941, p = 0.024) as significant. Longer survival was significantly associated with surgery for recurrent BMs (p = 0.00097), and additional analysis demonstrated the significant effect of complete resection on survival (p = 0.0027). In the subgroup of patients with systemic progression, a cutoff RTB of 0.97 cm3 (p = 0.00068) was found; patients who had received surgery also showed prolonged OS (p = 0.036). Single systemic therapy (p = 0.048) and the combination of radiotherapy and systemic therapy had a significant influence on survival (p = 0.036).

CONCLUSIONS

RTB is a strong prognostic factor for survival in patients with recurrent BMs. Operated patients with recurrent BMs showed longer survival independent of systemic progression. Maximal cytoreduction should be targeted to achieve better long-term outcomes.

Minimizing Intracranial Disease Before Stereotactic Radiation in Single or Solitary Brain Metastases

BACKGROUND AND OBJECTIVES

Stereotactic radiotherapy (SRT) in multiple fractions (typically ≤5) can effectively treat a wide range of brain metastases, including those less suitable for single-fraction stereotactic radiosurgery (SRS). Prior prospective studies on surgical resection with stereotactic radiation have focused exclusively on SRS, and retrospective studies have shown equivocal results regarding whether surgery is associated with improved outcomes compared with SRT alone. We compared resection with postoperative cavity SRT or SRS to SRT alone in patients with 1 brain metastasis, while including patients receiving SRS alone as an additional reference group.

METHODS

We studied 716 patients in a retrospective, single-institution cohort diagnosed with single or solitary brain metastases from 2007 to 2020. Patients receiving whole-brain radiotherapy were excluded. Cox proportional hazards models were constructed for overall survival and additional intracranial outcomes.

RESULTS

After adjustment for potential confounders, surgery with cavity SRT/SRS was associated with decreased all-cause mortality (hazard ratio [HR]: 0.39, 95% CI [0.27-0.57], P = 1.52 × 10 -6 ) compared with SRT alone, along with lower risk of neurological death attributable to intracranial tumor progression (HR: 0.46, 95% CI [0.22-0.94], P = 3.32 × 10 -2 ) and radiation necrosis (HR: 0.15, 95% CI [0.06-0.36], P = 3.28 × 10 -5 ). Surgery with cavity SRS was also associated with decreased all-cause mortality (HR: 0.52, 95% CI [0.35-0.78], P = 1.46 × 10 -3 ), neurological death (HR: 0.30, 95% CI [0.10-0.88], P = 2.88 × 10 -2 ), and radiation necrosis (HR: 0.14, 95% CI [0.03-0.74], P = 2.07 × 10 -2 ) compared with SRS alone. Surgery was associated with lower risk of all-cause mortality and neurological death in cardinality-matched subsets of the cohort. Among surgical patients, gross total resection was associated with extended overall survival (HR: 0.62, 95% CI [0.40-0.98], P = 4.02 × 10 -2 ) along with lower risk of neurological death (HR: 0.31, 95% CI [0.17-0.57], P = 1.84 × 10 -4 ) and local failure (HR: 0.34, 95% CI [0.16-0.75], P = 7.08 × 10 -3 ).

CONCLUSION

In patients with 1 brain metastasis, minimizing intracranial disease specifically before stereotactic radiation is associated with improved oncologic outcomes.

Prognostic assessment in patients operated for brain metastasis from systemic tumors

BACKGROUND

Established models for prognostic assessment in patients with brain metastasis do not stratify for prior surgery. Here we tested the prognostic accuracy of the Graded Prognostic Assessment (GPA) score model in patients operated for BM and explored further prognostic factors.

METHODS

We included 285 patients operated for brain metastasis at the University Hospital Zurich in the analysis. Information on patient characteristics, imaging, staging, peri- and postoperative complications and survival were extracted from the files and integrated into a multivariate Cox hazard model.

RESULTS

The GPA score showed an association with outcome. We further identified residual tumor after surgery (p = 0.007, hazard ratio (HR) 1.6, 95% confidence interval (CI) 1.1-2.3) steroid use (p = 0.021, HR 1.7, 95% CI 1.1-2.6) and number of extracranial metastasis sites (p = 0.009, HR 1.4, 95% CI 1.1-1.6) at the time of surgery as independent prognostic factors. A trend was observed for postoperative infection of the subarachnoid space (p = 0.102, HR 3.5, 95% CI 0.8-15.7).

CONCLUSIONS

We confirm the prognostic capacity of the GPA score in a cohort of operated patients with brain metastasis. However, extent of resection and steroid use provide additional aid for the prognostic assessment in these patients.

Fluorescence and Intraoperative Ultrasound as Surgical Adjuncts for Brain Metastases Resection: What Do We Know? A Systematic Review of the Literature

(1) Background: brain metastases (BMs) are the most common neoplasm of the central nervous system; despite the high incidence of this type of tumour, to date there is no universal consensus on the most effective treatment in patients with BMs, even if surgery still plays a primary role. Despite this, the adjunct systems that help to reach the GTR, which are well structured for other tumour forms such as ultrasound and fluorescence systems, are not yet well employed and standardised in surgical practice. The aim of this review is to provide a picture of the current state-of-art of the roles of iOUS and intraoperative fluorescence to better understand their potential roles as surgical tools. (2) Methods: to reach this goal, the PubMed database was searched using the following string as the keyword: (((Brain cerebral metastasis [MeSH Major Topic])OR (brain metastasis, [MeSH Major Topic])) AND ((5-ala, [MeSH Terms]) OR (Aminolevulinicacid [All fields]) OR (fluorescein, [MeSH Terms]) OR (contrast enhanced ultrasound [MeSH Terms])OR ((intraoperative ultrasound. [MeSH Terms]))) AND (english [Filter]) AND ((english [Filter]) AND (2010:2022 [pdat])) AND (english [Filter]). (3) Results: from our research, a total of 661 articles emerged; of these, 57 were selected. 21 of these included BMs generically as a secondary class for comparisons with gliomas, without going deeply into specific details. Therefore, for our purposes, 36 articles were considered. (4) Conclusions: with regard to BMs treatment and their surgical adjuncts, there is still much to be explored. This is mainly related to the heterogeneity of patients, the primary tumour histology and the extent of systemic disease; regardless, surgery plays a paramount role in obtaining a local disease control, and more standardised surgical protocols need to be made, with the aim of optimizing the use of the available surgical adjuncts and in order to increase the rate of GTR.

The role of the neurologist in the diagnosis and treatment of brain metastases and carcinomatous meningitis

Traditionally, in the past, most of central nervous system metastases from solid tumors were associated with an advanced phase of the disease needing palliation only, while to date they increasingly develop as an early and/or solitary relapse in patients with the systemic disease under control. This review will cover all the aspects of a modern management of brain and leptomeningeal metastases from diagnosis to the different therapeutic options, either local (surgery, stereotactic radiosurgery, whole-brain radiotherapy with hippocampal avoidance) or systemic. Particular emphasis is reserved to the new-targeted drugs, that allow to target specifically driver molecular alterations. These new compounds pose new problems in terms of monitoring efficacy and adverse events, but increasingly they allow improvement of outcome in comparison to historical controls.

Surgical treatment of cerebellar metastases in elderly patients: A threshold that moves forward?

The impact of surgery for cerebellar brain metastases in elderly population has been the object of limited studies in literature. Given the increasing burden of their chronic illnesses, the decision to recommend surgery remains difficult. All patients aged ≥65 years, who underwent surgical resection of a cerebellar brain metastasis from May 2000 and May 2021 at IRCCS National Cancer Institute "Regina Elena", were analyzed. The study cohort includes 48 patients with a mean age of 70.8 years. 7 patients belonged to the II Class according to the RPA classification, 41 to the III Class; the median GPA classification was 1.5. Median pre-operative and post-operative KPS was 60. Median Charlson Comorbidity Index (CCI) was 11; median 5-variable modified Frailty Index was 2. Overall, 14 patients (29%) presented perioperative neurologic and systemic complications. 34 patients (71%) were able to perform adjuvant therapies as RT and/or CHT after surgery. A higher CCI predicted complications occurrence (p = 0.044), while significant factors for a post-operative KPS ≥70, were i) hemispheric location of the metastasis, ii) higher pre-operative KPS, iii) RPA II classification. Median Overall Survival was 7 months. A post-operative KPS <70 (p = 0.004) and a short time interval between diagnosis of the primary tumor and cerebellar metastasis appearance, were predictive for a worse outcome (p = 0.012). Our study suggests that selected elderly patients with cerebellar metastases may benefit from microsurgery to continue their adjuvant therapies, although a high complications rate should be taken in account.

Risk Factors of Second Local Recurrence in Surgically Treated Recurrent Brain Metastases: An Exploratory Analysis

BACKGROUND

A first local recurrence is common after resection or radiotherapy for brain metastasis (BM). However, patients with BMs can develop multiple local recurrences over time. Published data on second local recurrences are scarce. This study aimed to report predictors associated with a second local recurrence in patients with BMs who underwent a craniotomy for a first locally recurrent BM.

METHODS

Patients were identified from a database at Brigham and Women's Hospital in Boston. Hazard ratios and 95% confidence intervals for predictors of a second local recurrence were computed using a Cox proportional hazards model.

RESULTS

Of 170 identified surgically treated first locally recurrent lesions, 74 (43.5%) progressed to second locally recurrent lesions at a median of 7 months after craniotomy. Subtotal resection of the first local BM recurrence was significantly associated with shorter time to second local recurrence (hazard ratio = 2.09; 95% confidence interval, 1.27-3.45). Infratentorial location was associated with a worse second local recurrence prognosis (hazard ratio = 2.22; 95% confidence interval, 1.24-3.96).

CONCLUSIONS

A second local recurrence occurred after 43.5% of craniotomies for first recurrent lesions. Subtotal resection and infratentorial location were the strongest risk factors for worse second local recurrence prognosis following resection of first recurrent BM.

Focal cavity radiotherapy after neurosurgical resection of brain metastases: sparing neurotoxicity without compromising locoregional control

PURPOSE

Does focal cavity radiotherapy after resection of brain metastasis "spare" whole-brain radiotherapy, which is associated with toxicity for patients, through the complete course of their disease without compromising long-term local control of the brain?

METHODS

We retrospectively analyzed outcomes of patients who underwent adjuvant focal cavity radiotherapy between 2014 and 2021 at our center.

RESULTS

A total of 83 patients with 86 resected brain metastases were analyzed. 64% had singular, 36% two to four brain metastases. In cases with multiple metastases, omitted lesions were treated with radiosurgery. Median follow-up was 7.3 months (range 0-71.2 months), 1‑year overall survival rate was 57.8% (95% CI 44.9-68.8%). Radiotherapy was administered with a median biologically effective dose (α/β 10) surrounding the planning target volume of 48 Gy (range 23.4-60 Gy). Estimated 1‑year local control rate was 82.7% (95% CI 67.7-91.2%), estimated 1‑year distant brain control rate was 55.7% (95% CI 40.5-68.4%), estimated 1‑year leptomeningeal disease rate was 16.0% (95% CI 7.3-32.9%). Eleven distant brain recurrences could be salvaged with radiosurgery. In the further course of disease, 14 patients (17%) developed disseminated metastatic disease in the brain. Estimated 1‑year free of whole-brain radiotherapy rate was 72.3% (95% CI 57.1-82.9%). All applied treatments led to an estimated 1‑year neuro-control rate of 79.1% (95% CI 65.0-88.0%), estimated 1‑year radionecrosis rate was 23% (95% CI 12.4-40.5%).

CONCLUSION

In our single-center study, focal cavity radiotherapy was associated with high local control. In three out of four patients, whole-brain radiotherapy could be avoided in the complete course of disease, using radiosurgery as salvage approach without compromising neuro-control.

Evaluation of patient STress level caused by radiological Investigations in early Postoperative phase After CRANIOtomy (IPAST-CRANIO): protocol of a Swiss prospective cohort study

INTRODUCTION

Postoperative imaging after neurosurgical interventions is usually performed in the first 72 hours after surgery to provide an accurate assessment of postoperative resection status. Patient frequently report that early postoperative examination after craniotomy for tumour and vascular procedures is associated with distress, exertion, nausea and pain. Delayed postoperative imaging (between 36 and 72 hours postoperatively) may have an advantage regarding psychological and physical stress compared with early imaging. The goal of this study is to evaluate and determine the optimal time frame for postoperative imaging with MRI and CT in terms of medical and neuroradiological implications and patient's subjective stress level.

METHODS AND ANALYSIS

Data will be prospectively collected from all patients aged 18-80 years who receive postoperative MRI or CT imaging following a craniotomy for resection of a cerebral tumour (benign and malignant) or vascular surgery. Participants have to complete questionnaires containing visual analogue scores (VAS) for headache and nausea, Body Part Discomfort score and a single question addressing subjective preference of timing of postoperative imaging after craniotomy. The primary endpoint of the study is the difference in subjective stress due to imaging studies after craniotomy, measured just before and after postoperative MRI or CT with the above-mentioned instruments. Subjective stress is defined as a combination of the scores VAS pain, VAS nausea and 0.5* Body Part Discomfort core.This study determines whether proper timing of postoperative imaging can improve patient satisfaction and reduce pain, stress and discomfort caused by postoperative imaging. Factors causing additional postoperative stress are likely responsible for delayed recovery of neurosurgical patients.

ETHICS AND DISSEMINATION

The institutional review board (Kantonale Ethikkommission Zürich) approved this study on 4 August 2020 under case number BASEC 2020-01590. The authors are planning to publish the data of this study in a peer-reviewed paper. After database closure, the data will be exported to the local data repository (Zurich Open Repository and Archive) of the University of Zurich. The sponsor (LR) and the project leader (MR.G) will make the final decision on the publication of the results. The data that support the findings of this study are available on request from the corresponding author LT. The data are not publicly available due to privacy/ethical restrictions.

TRIAL REGISTRATION NUMBER

NCT05112575; ClinicalTrials.gov.

MRI-Based Risk Assessment for Incomplete Resection of Brain Metastases

Object

Recent studies demonstrated that gross total resection of brain metastases cannot always be achieved. Subtotal resection (STR) can result in an early recurrence and might affect patient survival. We initiated a prospective observational study to establish a MRI-based risk assessment for incomplete resection of brain metastases.

Methods

All patients in whom ≥1 brain metastasis was resected were prospectively included in this study (DRKS ID: DRKS00021224; Nov 2020 - Nov 2021). An interdisciplinary board of neurosurgeons and neuroradiologists evaluated the pre- and postoperative MRI (≤48h after surgery) for residual tumor. Extensive neuroradiological analyses were performed to identify risk factors for an unintended STR which were integrated into a regression tree analysis to determine the patients' individual risk for a STR.

Results

We included 150 patients (74 female; mean age: 61 years), in whom 165 brain metastases were resected. A STR was detected in 32 cases (19.4%) (median residual tumor volume: 1.36ml, median EOR_rel: 93.6%), of which 6 (3.6%) were intended STR (median residual tumor volume: 3.27ml, median EOR_rel: 67.3%) - mainly due to motor-eloquent location - and 26 (15.8%) were unintended STR (uSTR) (median residual tumor volume: 0.64ml, median EOR_rel: 94.7%). The following risk factors for an uSTR could be identified: subcortical metastasis ≥5mm distant from cortex, diffuse contrast agent enhancement, proximity to the ventricles, contact to falx/tentorium and non-transcortical approaches. Regression tree analysis revealed that the individual risk for an uSTR was mainly associated to the distance from the cortex (distance ≥5mm vs. <5mm: OR 8.0; 95%CI: 2.7 - 24.4) and the contrast agent patterns (diffuse vs. non-diffuse in those with distance ≥5mm: OR: 4.2; 95%CI: 1.3 - 13.7). The preoperative tumor volume was not substantially associated with the extent of resection.

Conclusions

Subcortical metastases ≥5mm distant from cortex with diffuse contrast agent enhancement showed the highest incidence of uSTR. The proposed MRI-based assessment allows estimation of the individual risk for uSTR and can help indicating intraoperative imaging.

The Impact of Postoperative Tumor Burden on Patients With Brain Metastases

Background

Brain metastases were considered to be well-defined lesions, but recent research points to infiltrating behavior. Impact of postoperative residual tumor burden (RTB) and extent of resection are still not defined enough.

Patients and Methods

Adult patients with surgery of brain metastases between April 2007 and January 2020 were analyzed. Early postoperative MRI (<72 h) was used to segment RTB. Survival analysis was performed and cutoff values for RTB were revealed. Separate (subgroup) analyses regarding postoperative radiotherapy, age, and histopathological entities were performed.

Results

A total of 704 patients were included. Complete cytoreduction was achieved in 487/704 (69.2%) patients, median preoperative tumor burden was 12.4 cm³ (IQR 5.2–25.8 cm³), median RTB was 0.14 cm³ (IQR 0.0–2.05 cm³), and median postoperative tumor volume of the targeted BM was 0.0 cm³ (IQR 0.0–0.1 cm³). Median overall survival was 6 months (IQR 2–18). In multivariate analysis, preoperative KPSS (HR 0.981982, 95% CI, 0.9761–0.9873, p < 0.001), age (HR 1.012363; 95% CI, 1.0043–1.0205, p = 0.0026), and preoperative (HR 1.004906; 95% CI, 1.0003–1.0095, p = 0.00362) and postoperative tumor burden (HR 1.017983; 95% CI; 1.0058–1.0303, p = 0.0036) were significant. Maximally selected log rank statistics showed a significant cutoff for RTB of 1.78 cm³ (p = 0.0022) for all and 0.28 cm³ (p = 0.0047) for targeted metastasis and cutoff for the age of 67 years (p < 0.001). (Stereotactic) Radiotherapy had a significant impact on survival (p < 0.001).

Conclusions

RTB is a strong predictor for survival. Maximal cytoreduction, as confirmed by postoperative MRI, should be achieved whenever possible, regardless of type of postoperative radiotherapy.

Mini-craniotomy for intra-axial brain tumors: a comparison with conventional craniotomy in 306 patients harboring non-dural based lesions

The use of a mini-craniotomy approach involving linear skin incision and a bone flap of about 3 cm has been reported for several neurosurgical diseases, such as aneurysms or cranial base tumors. More superficial lesions, including intra-axial tumors, may occasionally raise concerns due to insufficient control of the tumor boundaries. The convenience of a minimally invasive approach to intrinsic brain tumors was evaluated by comparing 161 patients who underwent mini-craniotomy (MC) for intra-axial brain tumors with a group of 145 patients operated on by the same surgical team through a conventional craniotomy (CC). Groups were propensity-matched for age, preoperative condition, size and location of the tumor, and pathological diagnosis. Results were analyzed focusing on operative time, the extent of resection, clinical outcome, hospitalization time, and time to start adjuvant therapy. Mini-craniotomy was equally effective in terms of extent of resection (GTR: 70.9% in the MC group vs 70.5% in the CC group) but had shorter operative time (average: 165 min in the MC group vs 205 min in the CC group p < 0.001) and lower rate of postoperative complications both superficial (1.03% vs 6.5% in the CC group p = 0.009) and deep (4% in the MC group vs 5.5% in the CC group p = 0,47). No relationship was found between the size or location of the tumor and resection rate. The MC group had reduced hospitalization time (average: 5.8 days vs 7.6 in CC group p < 0.001) and faster access to adjuvant therapies. 92.5% of the MC patients, which were scheduled for treatment, started radiotherapy within 8 weeks after surgery as opposed to 84.1% in the CC group (p = 0.04). These findings support the increasing use of mini-craniotomy for intra-axial brain tumors.

Surgery for brain metastases-impact of the extent of resection

BACKGROUND

Surgical resection of brain metastases improves symptoms and survival in selected patients. The benefit of gross total resection is disputed, as most patients are believed to succumb from their non-CNS tumor burden. We investigated the association between overall survival and residual tumor after surgery for single brain metastases.

METHODS

We reviewed adults who underwent surgery for a single brain metastasis at a regional referral center (2011-2018). Gross total resection was defined as no visible residual tumor on cerebral MRI 12-48 h postoperatively.

RESULTS

We included 373 patients. The most common primary tumors were lung cancer (36%) and melanoma (24%). We identified gross total resection in 238 patients (64%). Median overall survival was 11.0 months, 8.0 (6.2-9.8) months for patients with subtotal resection and 13.0 (9.7-16.3) months for patients with gross total resection. In a multivariate regression analysis including preoperative prognostic factors, gross total resection was associated with longer overall survival (HR: 0.66, p = 0.003). Postoperative radiotherapy administered within 6 weeks did not significantly alter the hazard ratio estimates for grade of resection.

CONCLUSIONS

Our study suggests improved survival with gross total resection compared to subtotal resection. The importance of extent of resection in surgery for brain metastases should not be discarded.

The evolving role of neurosurgery for central nervous system metastases in the era of personalized cancer therapy

Recent therapeutic advances involving the use of systemic targeted treatments and immunotherapeutic agents in patients with advanced cancers have translated into improved survival rates. Despite the emergence of such promising pharmacological therapies and extended survival, the frequency of metastases in the central nervous system has steadily increased. Effective medical and surgical therapies are available for many patients with brain metastases and need to be incorporated into multi-disciplinary care protocols. The role of neurosurgeons is evolving within these multi-disciplinary care teams. Surgical resection of brain metastases can provide immediate relief from neurological symptoms due to large lesions and provides the histopathological diagnosis in cases of no known primary malignancy. In situations where immunotherapy is part of the oncological treatment plan, surgery may be proposed for expeditious relief of edema to remove the need for steroids. In patients with multiple brain metastases and mixed response to therapeutics or radiosurgery, tumour resampling allows tissue analysis for druggable targets or to distinguish radiation effects from progression. Ventriculo-peritoneal shunting may improve quality of life in patients with hydrocephalus associated with leptomeningeal tumour dissemination and may allow for time to administer more therapy thus prolonging overall survival. Addressing the limited efficacy of many oncological drugs for brain metastases due to insufficient blood-brain barrier penetrance, clinical trial protocols in which surgical specimens are analysed after pre-surgical administration of therapeutics offer pharmacodynamic insights. Comprehensive neurosurgical assessment remains an integral element of multi-disciplinary oncological care of patients with brain metastases and is integral to tumour biology research and therapeutic advancement.

Fluorescence-Guided Surgery: A Review on Timing and Use in Brain Tumor Surgery

Fluorescence-guided surgery (FGS) allows surgeons to have improved visualization of tumor tissue in the operating room, enabling maximal safe resection of malignant brain tumors. Over the past two decades, multiple fluorescent agents have been studied for FGS, including 5-aminolevulinic acid (5-ALA), fluorescein sodium, and indocyanine green (ICG). Both non-targeted and targeted fluorescent agents are currently being used in clinical practice, as well as under investigation, for glioma visualization and resection. While the efficacy of intraoperative fluorescence in studied fluorophores has been well established in the literature, the effect of timing on fluorophore administration in glioma surgery has not been as well depicted. In the past year, recent studies of 5-ALA use have shown that intraoperative fluorescence may persist beyond the previously studied window used in prior multicenter trials. Additionally, the use of fluorophores for different brain tumor types is discussed in detail, including a discussion of choosing the right fluorophore based on tumor etiology. In the following review, the authors will describe the temporal nature of the various fluorophores used in glioma surgery, what remains uncertain in FGS, and provide a guide for using fluorescence as a surgical adjunct in brain tumor surgery.

The Management of Brain Metastases-Systematic Review of Neurosurgical Aspects

The multidisciplinary management of patients with brain metastases (BM) consists of surgical resection, different radiation treatment modalities, cytotoxic chemotherapy, and targeted molecular treatment. This review presents the current state of neurosurgical technology applied to achieve maximal resection with minimal morbidity as a treatment paradigm in patients with BM. In addition, we discuss the contribution of neurosurgical resection on functional outcome, advanced systemic treatment strategies, and enhanced understanding of the tumor biology.

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.

Prognostic Value of 5-ALA Fluorescence, Tumor Cell Infiltration and Angiogenesis in the Peritumoral Brain Tissue of Brain Metastases

Simple Summary

In a recent study, we observed 5-ALA fluorescence not only in brain metastases (BM) but also in the peritumoral brain tissue. However, the histopathological correlate of visible 5-ALA fluorescence in the peritumoral brain tissue is not fully understood. Therefore, we safely collected and analyzed tissue samples from fluorescing and non-fluorescing peritumoral brain tissue. Surprisingly, 5-ALA fluorescence in the peritumoral brain tissue did not correlate with tumor cell infiltration but did show a significant relation with angiogenesis. Moreover, the presence of angiogenesis significantly correlated with shorter time to local progression/recurrence and one-year survival. Consequently, angiogenesis in the peritumoral brain tissue might be a novel prognostic marker in BM. This represents the first study in the literature describing the prognostic impact of angiogenesis in fluorescent peritumoral brain tissue of BM, which might support individualized perioperative treatment concepts in the future.

Abstract

Complete resection is an indispensable treatment option in the management of brain metastases (BM). 5-aminolevulinic acid (5-ALA) fluorescence is used for improved intraoperative visualization of tumor tissue in gliomas and was recently observed in BM. We investigated the potential of 5-ALA fluorescence to visualize the infiltrative growth of BM in the peritumoral brain tissue and its histopathological correlate. Patients with BM resection after 5-ALA administration and collection of tissue samples from peritumoral brain tissue were included. Each tissue sample was histopathologically investigated for tumor cell infiltration and angiogenesis. Altogether, 88 samples were collected from the peritumoral brain tissue in 58 BM of 55 patients. Visible 5-ALA fluorescence was found in 61 (69%) of the samples, tumor infiltration in 19 (22%) and angiogenesis in 13 (15%) of samples. Angiogenesis showed a significant correlation with presence of fluorescence (p = 0.008). Moreover, angiogenesis was related to visible 5-ALA fluorescence and showed an association with patient prognosis since it was significantly correlated to shorter time to local progression/recurrence (p = 0.001) and lower one-year survival (p = 0.031). Consequently, angiogenesis in the peritumoral brain tissue of BM might be a novel prognostic marker for individualized perioperative treatment concepts in the future.

Injectable In Situ Self-Cross-Linking Hydrogels Based on Hemoglobin, Carbon Quantum Dots, and Sodium Alginate for Real-Time Detection of Wound Bacterial Infection and Efficient Postoperative Prevention of Tumor Recurrence

Postoperative wound repair of solid tumors resection, which is afflicted by the complex tumor microenvironment (TME) and associated with the bacterial infection, is worsening and demands prompt solutions. Meanwhile, the tumor recurrence is frequently seen during the subsequent treatment due to intraoperative bleeding. For effective postoperative cancer therapy, nanoscale carriers occur as innovative and sensitive tools for monitoring the wound state, avoiding bacterial infection, and restraining tumor recurrence. Herein, a multifunctional sodium alginate (SA) hydrogel immobilizing hemoglobin (Hb) and pH-sensitive fluorescent changing carbon quantum dots (CQDs) is rationally designed. The multifunctionalization of obtained alginate@hemoglobin@CQDs hydrogel (SA@Hb@CQDs) simultaneously consists of detection, hemostasis, and chemodynamic therapy (CDT) with monitoring of wound pH based on CQDs, stanching triggered from SA hydrogel, and Fenton reaction induced by Hb. We demonstrated that SA@Hb@CQDs can stop bleeding quickly, collect wound status information in real-time, and avert bacterial infection as well as inhibit local tumor recurrence effectively. Therefore, our work provides a promising combination approach for postoperative tumor therapy.

Age-stratified clinical performance and survival of patients with IDH-wildtype glioblastoma homogeneously treated by radiotherapy with concomitant and maintenance temozolomide

OBJECTIVE

Isocitrate dehydrogenase (IDH)-wildtype glioblastomas are the most malignant glial tumours. Median survival is only 14-16 months after diagnosis, with patients aged ≥ 65 years reportedly showing worse outcome. This study aimed to further evaluate the prognostic role of age in a homogenously treated patient cohort.

METHODS

The study includes 132 IDH-wildtype glioblastoma patients treated between 2013 and 2017 with open resection followed by radiotherapy with concomitant and maintenance temozolomide. Patients were dichotomized into a non-elderly (< 65 years) and an elderly (≥ 65 years) group. Extent of resection and the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status were determined for each tumour. Clinical and radiological follow-up data were obtained at 6 weeks after the end of radiation therapy and thereafter in 3-month intervals. Progression-free survival (PFS) and overall survival (OS) were evaluated in univariate and multivariate cox regression analyses.

RESULTS

The elderly group consisted of 58 patients (median age: 70.5 years) and the non-elderly group of 74 patients (median age: 55 years). Median pre- and postoperative operative Karnofsky Performance Scale (KPS), Eastern Cooperative Oncology Group (ECOG) score and National Institutes of Stroke Scale (NIHSS) were not significantly different between the groups, but KPS and ECOG scores became significantly worse in the elderly group at 6 weeks after termination of radiation therapy. Neither PFS nor OS differed significantly between the age groups. Patients with MGMT promoter-methylated tumours survived longer.

CONCLUSION

Elderly patients in good pre- and postoperative clinical conditions may show similar outcome as younger patients when treated according to standard of care. However, elderly patients may suffer more frequently from clinical deterioration following chemoradiotherapy. In both age groups, MGMT promoter methylation was linked to longer PFS and OS.

Postoperative Magnetic Resonance Imaging After Surgery of Brain Metastases: Analysis of Extent of Resection and Potential Risk Factors for Incomplete Resection

BACKGROUND

Extent of resection (EOR) constitutes a crucial factor for patient prognosis in surgery of brain metastases (BMs). According to early studies using postoperative magnetic resonance imaging (MRI), an unexpected residual tumor was not uncommon. Knowledge of potential risk factors for incomplete BM resection would be of major importance to optimize surgical strategies. The aim of this study was to evaluate EOR in a large cohort and analyze potential risk factors for incomplete BM resection.

METHODS

Patients with BM resection and available postoperative MRI were included. Intraoperative estimation of EOR by the neurosurgeon was noted. Additionally, EOR was determined by postoperative MRI. Potential risk factors for incomplete resection were investigated.

RESULTS

There were 145 patients with 163 BMs included. According to postoperative MRI, complete resection was achieved in 103 (63%) BMs, and resection was incomplete in 44 (27%) BMs. Postoperative MRI detected unexpected residual tumor in 32 (25%) BMs, and a misjudgment of the EOR by the neurosurgeon was found in 29% of cases. Regarding risk factors for incomplete resection, preoperative tumor volume was significantly larger in incompletely resected BMs compared with completely resected BMs (P = 0.011). All other analyzed risk factors had no significant influence on EOR.

CONCLUSIONS

Our data indicate that postoperative MRI is able to detect a high portion of unexpected residual tumors after surgery of BMs. Preoperative tumor volume in particular represents an important risk factor for incomplete resection, and hence neurosurgeons should pay special attention to avoid residual tumor tissue.

Perioperative imaging in patients treated with resection of brain metastases: a survey by the European Association of Neuro-Oncology (EANO) Youngsters committee

BACKGROUND

Neurosurgical resection represents an important treatment option in the modern, multimodal therapy approach of brain metastases (BM). Guidelines for perioperative imaging exist for primary brain tumors to guide postsurgical treatment. Optimal perioperative imaging of BM patients is so far a matter of debate as no structured guidelines exist.

METHODS

A comprehensive questionnaire about perioperative imaging was designed by the European Association of Neuro-Oncology (EANO) Youngsters Committee. The survey was distributed to physicians via the EANO network to perform a descriptive overview on the current habits and their variability on perioperative imaging. Chi square test was used for dichotomous variables.

RESULTS

One hundred twenty physicians worldwide responded to the survey. MRI was the preferred preoperative imaging method (93.3%). Overall 106/120 (88.3%) physicians performed postsurgical imaging routinely including MRI alone (62/120 [51.7%]), postoperative CT (29/120 [24.2%]) and MRI + CT (15/120 [12.5%]). No correlation of postsurgical MRI utilization in academic vs. non-academic hospitals (58/89 [65.2%] vs. 19/31 [61.3%], p = 0.698) was found. Early postoperative MRI within ≤72 h after resection is obtained by 60.8% of the participants. The most frequent reason for postsurgical imaging was to evaluate the extent of tumor resection (73/120 [60.8%]). In case of residual tumor, 32/120 (26.7%) participants indicated to adjust radiotherapy, 34/120 (28.3%) to consider re-surgery to achieve complete resection and 8/120 (6.7%) to evaluate both.

CONCLUSIONS

MRI was the preferred imaging method in the preoperative setting. In the postoperative course, imaging modalities and timing showed high variability. International guidelines for perioperative imaging with special focus on postoperative MRI to assess residual tumor are warranted to optimize standardized management and adjuvant treatment decisions for BM patients.

The Utility of Early Postoperative Neuroimaging in Elective/Semielective Craniotomy Patients: A Single-Arm Prospective Trial

BACKGROUND

The necessity and timing of early postoperative imaging (POI) are debated in many studies. Despite the consensus that early POI does not change patient management, these examinations are routinely performed. This is the first prospective study related to POI. Our aims were to assess the necessity of early POI in asymptomatic patients and to verify accuracy of the presented algorithm.

METHODS

This was an algorithm-based prospective single-center study. The algorithm addressed preoperative, perioperative, and postoperative considerations, including estimated pathology type, device placement, and postoperative neurologic change. Early computed tomography scans were obtained in all patients, but if postoperative algorithm indications did not recommend a scan, the treating team was blinded to them, and patient management was conducted based on clinical examinations alone. A neuroradiologist and study-independent neurosurgeon reviewed all the scans.

RESULTS

Of 103 enrolled patients, 88 remained asymptomatic, and 15 experienced symptoms postoperatively. Pathology was present on POI in 1% of the asymptomatic patients and 53% of the symptomatic patients (P < 0.001). In the asymptomatic group, no treatment modifications were made postoperatively. Blinding of the surgical team was not removed, and 20% of the symptomatic patients returned to the operating room because of imaging and neurologic findings. The goal of <5% algorithm failure was reached with statistical significance.

CONCLUSIONS

In asymptomatic postoperative patients in whom early imaging is not performed for oncologic indications, device placement verification, or similar reasons, POI is unnecessary and does not change the management of these patients.

Pseudo-continuous arterial spin labelling shows high diagnostic performance in the detection of postoperative residual lesion in hyper-vascularised adult brain tumours

OBJECTIVES

Our aim was to evaluate the contribution of pseudo-continuous arterial spin labelling (pCASL) in the detection of a postoperative residual lesion in adult brain tumours.

METHODS

Seventy-five patients were prospectively included. Following the results of preoperative DSC-PWI assessment, intra-axial lesions, including high-grade gliomas (n = 43) and certain metastases (n = 14), were classified as hyper-vascular (HV+ group, n = 57); other lesions, including low-grade gliomas and certain metastases, were classified as non-hyper-vascular (HV- group, n = 18). To confirm the absence/presence of a residual lesion or disease progression, postoperative MRI including pCASL sequence and follow-up-MRI were performed within 72 h and 1-6 months after the resection, respectively. Two raters evaluated the images. Mean and maximal ASL cerebral blood flow (CBF) values were measured in the perioperative region and normalised to the contralateral tissue. The pCASL-CBF maps and post-contrast T1WI were visually assessed for residual lesion. Quantitative data were analysed with unpaired Student t and Mann-Whitney U tests and the visual diagnostic performance with the McNemar test.

RESULTS

In the HV+ group, the mean normalised CBF was 1.97 ± 0.59 and 0.97 ± 0.29 (p < 0.0001, AUC = 0.964, cut-off = 1.27) for patients with or without residual tumours, respectively. The mean normalised CBF was not discriminative for assessing residual tumours in the HV- group (p = 0.454). Visual CBF evaluation allowed 92.98% patients belonging to the HV+ group to be correctly classified (sensitivity 93.02%, specificity 92.86%, p < 0.001). Visual evaluation was correlated with contrast enhancement evaluation and with the mean normalised CBF values (r = 0.505, p < 0.0001 and 0.838, p < 0.0001, respectively).

CONCLUSION

Qualitative and quantitative ASL evaluation shows high diagnostic performance in postoperative assessment of hyper-perfused tumours. In this case, postoperative pCASL may be useful, especially if contrast injection cannot be performed or when contrast enhancement is doubtful.

KEY POINTS

• Evaluation of postoperative residual lesion in the case of brain tumours is an imaging challenge. • This prospective monocentric study showed that increased normalised cerebral blood flow assessed by pseudo-continuous arterial spin labelling (pCASL) correlates well with the presence of a residual tumour in the case of hyper-vascular tumour diagnosed on preoperative MRI. • Qualitative and quantitative pCASL is an informative sequence for hyper-vascular residual tumour, especially if acquired more than 48 h after brain tumour surgery, when contrast enhancement can give ambiguous results due to blood-brain barrier disruption.

5-Aminolevulinic Acid Fluorescence Indicates Perilesional Brain Infiltration in Brain Metastases

Background

In glioma surgery, 5-aminolevulinic acid (5-ALA) fluorescence reflects tumor infiltration, and fluorescence-assisted resection correlates with higher removal rates and improved progression-free survival. Recent studies report that a sizable proportion of brain metastases exhibit peritumoral infiltration on the cellular level. There is little information regarding whether 5-ALA is useful to guide surgery in the peritumoral zone in metastases. The aim of this study was to assess histologically whether 5-ALA fluorescence accurately reflects metastatic brain infiltration.

Methods and Materials

Fluorescence-assisted tumor resection was performed in 27 patients with brain metastases. Patients received 20 mg/kg 5-ALA 3 hours before anesthesia. After resection, biopsy specimens of the surrounding parenchyma were analyzed for 5-ALA fluorescence and histologic evidence of infiltrating tumor cells. The correlation between 5-ALA positivity and immunohistochemical evidence of tumor in the peritumoral zone was also assessed.

Results

Of 27 metastases, 23 (85%) were 5-ALA positive. For qualitative tissue analysis, 110 of 125 samples were collected. Metastatic infiltration was present in 49 samples with faint or red fluorescence; 33 samples without fluorescence were tumor-free. The presence of metastatic infiltration correlated with fluorescence (P < 0.001). Tumor infiltration correlated with fluorescence (blue fluorescence 0.09% ± 0.04% and red or faint fluorescence 3.26%; P = 0.003).

Conclusions

Infiltration of surrounding brain tissue is a common finding in brain metastases in selected primary tumors. 5-ALA fluorescence correlates with tumor cell infiltration and might guide more radical resection.

Quantification of PpIX-fluorescence of cerebral metastases: a pilot study

5-ALA fluorescence-guided surgery (FGS) is a major advance in neuro-oncological surgery. So far, Protoporphyrin IX (PpIX)-fluorescence has been observed in about half of cerebral metastases resected with routinely equipped microscopes during 5-ALA FGS. The aim of the present pilot study was to quantify PpIX-induced fluorescence of cerebral metastases with a spectrometer. We hypothesize that non-fluorescing metastases under the operating microscope may have spectrometrically measurable levels of fluorescence. A second aim was to analyze correlations between quantified 5-ALA fluorescence and histology or primary tumor type, respectively. Standard FGS was performed in all patients. The fluorescence intensity of the metastasis was semi-quantitatively determined in vivo by a senior surgeon using a special surgical microscope equipped for FGS. A systematic spectrometric ex vivo evaluation of tumor specimens and PpIX-induced fluorescence was performed using a spectrometer connected by optic fibers to a handheld probe. Quantification of 5-ALA-derived fluorescence was measured in a standardized manner with direct contact between mini-spectrometer and metastasis. The difference between the maximum PpIX-fluorescence at 635 nm and the baseline fluorescence was defined as the PpIX fluorescence intensity of the metastasis and given in arbitrary units (AU). Diagnosis of a cerebral metastasis was confirmed by histopathological analysis. A total of 29 patients with cerebral metastases were included. According to neuropathological analysis, 11 patients suffered from non-small cell lung cancer, 10 patients from breast cancer, 6 patients from cancer originating in the gastro-intestinal tract, 1 patient suffered from a malignant melanoma and one patient from renal cancer. The mean age was 63 years (37-81 years). 15 patients were female, 14 patients male. 13 cerebral metastases were considered as ALA-positive by the surgeon. In nine metastases, 5-ALA fluorescence was not visible to the naked eye and could only be detected using the spectrometer. The threshold for an ALA signal rated as "positive" by the surgeon was PpIX fluorescence above 1.1 × 10⁶ AU. The mean PpIX fluorescence of all analyzed cerebral metastases was 1.29 × 10⁶ ± 0.23 × 10⁶ AU. After quantification, we observed a significant difference between the mean 5-ALA-derived fluorescence in NSCLC and breast cancer metastases (Mean Diff: - 1.2 × 10⁶; 95% CI of difference: - 2.2 × 10⁶ to - 0.15 × 10⁶; Šidák-adjusted p = 0.026). In our present pilot series, about half of cerebral metastases showed a 5-ALA fluorescence invisible to the naked eye. Over 50% of these non-fluorescent metastases show a residual 5-ALA fluorescence which can be detected and quantified using a spectrometer. Moreover, the quantified 5-ALA signal significantly differed with respect to the primary tumor of the corresponding cerebral metastasis. Further studies should evaluate the predictive value of the 5-ALA signal and if a quantified 5-ALA signal enables a reliable intraoperative differentiation between residual tumor tissue and edematous brain-in particular in metastases with a residual fluorescence signal invisible to the naked eye.

Risk factors for in-brain local progression in elderly patients after resection of cerebral metastases

Intracranial metastases are the most frequent brain tumor with recurrence rates after treatment of around 40–60%. Age is still considered a determinant of treatment and prognosis in this pathology. Recent studies analyzing the impact of metastasectomy in elderly patients focused on reporting perioperative mortality and morbidity rates but not on the evaluation of oncological outcome parameters. Aim of this study is to determine risk factors for in-brain local recurrence after brain surgery in this sub-population. From October 2009 until September 2016 all patients aged 65 years and above with histopathologically confirmed metastasis after surgical resection were retrospectively studied. Clinical, radiological and perioperative information was collected and statistically analysed. Follow-up consisted of clinical and radiological assessment every 3-months following surgery. 78 patients were included, of these 50% were female (39 patients). Median age was 71 years (66–83). Early postoperative-MRI verified a complete surgical resection in 41 patients (52.6%) and showed a tumor-remnant in 15 patients (19.2%). In 22 patients the MRI result was inconclusive (28.2%). None of the patients experienced severe complications due to surgery. The median postoperative NIHSS was adequate 1 ± 1.4 (0–6), nonetheless, insignificantly improved in comparison to the preoperative NIHSS (p = 0.16). A total of 20 patients (25.6%) presented local recurrence. The only statistically significant factor for development of local in-brain recurrence after resection of cerebral metastases in patients above 65 years of age was a tumor-remnant in the early postoperative MRI (p = 0.00005). Median overall survival was 13 months. Local in-brain recurrence after surgical resection of a cerebral metastasis in patients above 65 years of age was 25.6%. In our analysis, tumor-remnant in early postoperative MRI is the only risk factor for local in-brain recurrence. Oncological parameters in the present cohort do not seem to differ from recent phase III studies with non-geriatric patients. Nevertheless, controlled studies on the impact of metastasectomy in elderly patients delivering high quality reliable data are required.

Outcome after surgery in supratentorial and infratentorial solitary brain metastasis

BACKGROUND

The aim of this retrospective study was to investigate and compare the outcome after surgery in patients with a supratentorial solitary metastasis (SSM) and an infratentorial solitary metastasis (ISM). A worse prognosis has been reported in ISM.

METHODS

Fifty-two patients with a newly diagnosed solitary brain metastasis on MRI were included to identify risk factors affecting the outcome. Key variables included tumor size, staging of the primary tumor, time span of presurgical work-up, and surgical technique. Outcome variables included postoperative complications, tumor recurrence, and mortality. Kaplan-Meier survival analysis was applied.

RESULTS

Thirty patients with a SSM and 22 patients with an ISM underwent gross total resection. The tumor size did not have a statistical significant effect on survival. Presurgical work-up time was similar in SSM and ISM. Postoperative complications were more frequently encountered in ISM. Recurrence rate was comparable in SSM and ISM. Carcinomatous meningitis (CM) was more frequently seen in ISM, and CM was seen more often with the piecemeal resection technique. There was no statistical difference in overall survival between SSM and ISM.

CONCLUSIONS

This study identified factors that play a role in the outcome after surgery in patients with ISM and SSM on MRI. Postoperative complications seemed to be higher in ISM and CM was more often seen in ISM, but the worse prognosis in patients with ISM compared with SSM could not be confirmed.

Early postoperative MRI after resection of brain metastases-complete tumour resection associated with prolonged survival

BACKGROUND

This study aimed to investigate the incidence of residual tumour after resection of brain metastases using early postoperative magnetic resonance imaging (MRI) and the influence of residual tumour on overall patient survival.

METHODS

Data from 72 consecutive adult patients undergoing surgery for cerebral metastases over an 18-month study period were retrospectively collected. Early postoperative MRI was used to determine the presence of postoperative residual tumour. Patients were divided into three groups according to the presence of tumour remnant on early postoperative MRI: "no residual tumour", "non-measurable residual tumour" and "measurable residual tumour". Survival analysis (mean estimate survival time) was performed using the Kaplan-Meier and log-rank (mantel cox) tests and compared between groups. Surgical reports were evaluated with regard to the surgeon statement about intraoperative extent of resection (EOR) and compared with the presence of tumour remnant found on the early postoperative MRI.

RESULTS

Sixty-eight procedures were followed by early postoperative MRI. MRI verified the presence of "measurable residual tumour" following 15 procedures (22%). MRI confirmed complete resection in 57%. Gross total resection was described by the operating surgeon in 85% of the procedures. There was a significant difference in survival time after surgery between the group having no residual tumour on MRI and the group with measurable residual tumour (p = 0.025). This difference could not be explained by the differences in postoperative radiation therapy. The longest survival was found in patients with non-measurable and no residual tumour on early postoperative MRI, who also received postoperative radiotherapy.

CONCLUSION

Residual tumour was seen on MRI after 22% of the procedures. The intraoperative assessment of EOR performed by the surgeon diverged from the early postoperative MRI in 40% of procedures. Correct assessment of residual tumour thus requires early postoperative MRI. Measurable residual tumour on early postoperative MRI was associated with shorter overall survival independent on postoperative radiotherapy.

The Role of Navigated Transcranial Magnetic Stimulation Motor Mapping in Adjuvant Radiotherapy Planning in Patients With Supratentorial Brain Metastases

Purpose: In radiotherapy (RT) of brain tumors, the primary motor cortex is not regularly considered in target volume delineation, although decline in motor function is possible due to radiation. Non-invasive identification of motor-eloquent brain areas is currently mostly restricted to functional magnetic resonance imaging (fMRI), which has shown to lack precision for this purpose. Navigated transcranial magnetic stimulation (nTMS) is a novel tool to identify motor-eloquent brain areas. This study aims to integrate nTMS motor maps in RT planning and evaluates the influence on dosage modulations in patients harboring brain metastases.

Materials and Methods: Preoperative nTMS motor maps of 30 patients diagnosed with motor-eloquent brain metastases were fused with conventional planning imaging and transferred to the RT planning software. RT plans of eleven patients were optimized by contouring nTMS motor maps as organs at risk (OARs). Dose modulation analyses were performed using dose-volume histogram (DVH) parameters.

Results: By constraining the dose applied to the nTMS motor maps outside the planning target volume (PTV) to 15 Gy, the mean dose (Dmean) to the nTMS motor maps was significantly reduced by 18.1% from 23.0 Gy (16.9–30.4 Gy) to 18.9 Gy (13.5–28.8 Gy, p < 0.05). The Dmean of the PTV increased by 0.6 ± 0.3 Gy (1.7%).

Conclusion: Implementing nTMS motor maps in standard RT planning is feasible in patients suffering from intracranial metastases. A significant reduction of the dose applied to the nTMS motor maps can be achieved without impairing treatment doses to the PTV. Thus, nTMS might provide a valuable tool for safer application of RT in patients harboring motor-eloquent brain metastases.

Neuro-oncology perspective of treatment options in metastatic breast cancer

Breast cancer (BC) is a heterogeneous disease. Different subtypes of BC exhibit a peculiar natural history, metastatic potential and outcome. Stereotactic radiosurgery is the most used treatment for brain metastases (BM), while surgery is reserved for large and symptomatic lesions. Whole-brain radiotherapy is employed in multiple BM not amendable to radiosurgery or surgery, and it is not employed any more following local treatments of a limited number of BM. A critical issue is the distinction from pseudoprogression or radionecrosis, and tumor regrowth. Considering the increase of long-term survivors after combined or novel treatments for BM, cognitive dysfunctions following whole-brain radiotherapy represent an issue of utmost importance. Neuroprotective drugs and innovative radiotherapy techniques are being investigated to reduce this risk of cognitive sequelae. Leptomeningeal disease represents a devastating complication, either alone or in association to BM, thus targeted therapies are employed in HER2-positive BC brain and leptomeningeal metastases.

Surgery for brain metastases: An analysis of outcomes and factors affecting survival

OBJECTIVES

For patients who develop brain metastases from solid tumors, age, KPS, primary tumor status and presence of extracranial metastases have been identified as prognostic factors. However, the factors that affect survival in patients who are deemed fit to undergo resection of brain metastases have not been clearly elucidated hitherto.

PATIENTS AND METHODS

This is a retrospective analysis of a prospectively maintained database. All patients who underwent resection of intracranial metastases from solid tumors were included. Various patient, disease and treatment related factors were analyzed to assess their impact on survival.

RESULTS

Overall, 124 patients had undergone surgery for brain metastases from various primary sites. The median age and pre-operative performance score were 53 years and 80 respectively. Synchronous metastases were resected in 17.7% of the patients. The postoperative morbidity and mortality rates were 17.7% and 2.4% respectively. Adjuvant whole brain radiation was received by 64 patients. At last follow-up, 8.1% of patients had fresh post-surgical neurologic deficits. The median progression free and overall survival were 6.91 was 8.56 months respectively.

CONCLUSIONS

Surgical resection of for brain metastases should be considered in carefully selected patients. Gross total resection and receiving adjuvant whole brain RT significantly improves survival in these patients.

5-ALA fluorescence of cerebral metastases and its impact for the local-in-brain progression

Aim of the present study was to analyze the oncological impact of 5-ALA fluorescence of cerebral metastases. A retrospective analysis was performed for 84 patients who underwent 5-ALA fluorescence-guided surgery of a cerebral metastasis. Dichotomized fluorescence behavior was correlated to the histopathological subtype and primary site of the metastases, the degree of surgical resection on an early postoperative MRI within 72 hours after surgery, the local in-brain-progression rate and the overall survival. 34/84 metastases (40.5%) showed either strong or faint and 50 metastases (59.5%) no 5-ALA derived fluorescence. Neither the primary site of the cerebral metastases nor their subtype correlated with fluorescence behavior. The dichotomized 5-ALA fluorescence (yes vs. no) had no statistical influence on the degree of surgical resection. Local in-brain progression within or at the border of the resection cavity was observed in 26 patients (30.9%). A significant correlation between 5-ALA fluorescence and local in-brain-progression rate was observed and patients with 5-ALA-negative metastases had a significant higher risk of local recurrence compared to patients with 5-ALA positive metastases. After exclusion of the 20 patients without any form of adjuvant radiation therapy, there was a trend towards a relation of the 5-ALA behavior on the local recurrence rate and the time to local recurrence, although results did not reach significance anymore. Absence of 5-ALA-induced fluorescence may be a risk factor for local in-brain-progression but did not influence the mean overall survival. Therefore, the dichotomized 5-ALA fluorescence pattern might be an indicator for a more aggressive tumor.

The role of surgery for brain metastases from solid tumors

Surgery, stereotactic radiosurgery, radiotherapy, and chemotherapy including novel targeted therapy strategies and any combination thereof as well as supportive care are the key elements for treatment of brain metastases. Goals of microsurgery are to obtain tissue samples for histologic diagnosis (particularly in case of uncertainty about the unknown primary tumor but also in the context of future targeted therapies), to relieve burden from space-occupying effects, to improve local tumor control, and to prolong overall survival. Complete surgical resection improves local tumor control and may even affect overall survival. Stereotactic radiosurgery is an equal effective alternative for metastases up to 3 cm in diameter, especially in highly eloquent or deep seated location. Gross total resection (as defined by immediate postoperative MRI) does not necessarily have to be combined with whole brain radiotherapy (WBRT), at least for patients with good performance status and controlled systemic disease. Particularly in cases of incomplete resections, focal irradiation or radiosurgery of the resection cavity or tumor remnant rather than WBRT may be attempted.

Breast Cancer in the Central Nervous System: Multidisciplinary Considerations and Management

Breast cancer is the second most common primary tumor associated with central nervous system (CNS) metastases. Patients with metastatic HER2-positive or triple-negative (estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, HER2-negative) breast cancer are at the highest risk of developing parenchymal brain metastases. Leptomeningeal disease is less frequent but is distributed across breast cancer subtypes, including lobular breast cancer. Initial treatment strategies can include surgery, radiation, intravenous or intrathecal chemotherapy, and/or targeted approaches. In this article, we review the epidemiology of breast cancer brain metastases, differences in clinical behavior and natural history by tumor subtype, and important considerations in the multidisciplinary treatment of these patients. We will highlight new findings that impact current standards of care, clinical controversies, and notable investigational approaches in clinical testing.

[Delineation of the surgical bed of operated brain metastases treated with adjuvant stereotactic irradiation: A review]

Stereotactic radiotherapy of the surgical bed of brain metastases is a technique that comes supplant indications of adjuvant whole brain radiotherapy after surgery. After a growing number of retrospective studies, a phase III trial has been presented and validated this indication. However, several criteria such as the dose, the fractionation, the use of a margin and definition of volumes remain to be defined. Our study consisted in making a literature review in order to provide a guideline of delineation of surgical beds of brain metastases, as well as the different modalities of their implementation process.

Diagnosis and treatment of brain metastases from solid tumors: guidelines from the European Association of Neuro-Oncology (EANO)

The management of patients with brain metastases has become a major issue due to the increasing frequency and complexity of the diagnostic and therapeutic approaches. In 2014, the European Association of Neuro-Oncology (EANO) created a multidisciplinary Task Force to draw evidence-based guidelines for patients with brain metastases from solid tumors. Here, we present these guidelines, which provide a consensus review of evidence and recommendations for diagnosis by neuroimaging and neuropathology, staging, prognostic factors, and different treatment options. Specifically, we addressed options such as surgery, stereotactic radiosurgery/stereotactic fractionated radiotherapy, whole-brain radiotherapy, chemotherapy and targeted therapy (with particular attention to brain metastases from non-small cell lung cancer, melanoma and breast and renal cancer), and supportive care.

Treatment of brain metastasis: current status and future directions

PURPOSE OF REVIEW

The purpose of this review is to highlight the most recent advances in the management of brain metastases.

RECENT FINDINGS

Role of local therapies (surgery and stereotactic radiosurgery), new approaches to minimize cognitive sequelae following whole-brain radiotherapy and advances in targeted therapies have been reviewed.

SUMMARY

The implications for clinical trials and daily practice of the increasing use of stereotactic radiosurgery in multiple brain metastases and upfront targeted agents in asymptomatic brain metastases are discussed.

Stereotactic radiotherapy following surgery for brain metastasis: Predictive factors for local control and radionecrosis

PURPOSE

To evaluate local control and adverse effects after postoperative hypofractionated stereotactic radiosurgery in patients with brain metastasis.

METHODS

We reviewed patients who had hypofractionated stereotactic radiosurgery (7.7Gy×3 prescribed to the 70% isodose line, with 2mm planning target volume margin) following resection from March 2008 to January 2014. The primary endpoint was local failure defined as recurrence within the surgical cavity. Secondary endpoints were distant failure rates and the occurrence of radionecrosis.

RESULTS

Out of 95 patients, 39.2% had metastatic lesions from a non-small cell lung cancer primary tumour. The median Graded Prognostic Assessment score was 3 (48% of patients). One-year local control rates were 84%. Factors associated with improved local control were no cavity enhancement on pre-radiation MRI (P<0.00001), planning target volume less than 12cm³ (P=0.005), Graded Prognostic Assessment score 2 or above (P=0.009). One-year distant cerebral control rates were 56%. Thirty-three percent of patients received whole brain radiation therapy. Histologically proven radionecrosis of brain tissue occurred in 7.2% of cases. The size of the preoperative lesion and the volume of healthy brain tissue receiving 21Gy (V₂₁) were both predictive of the incidence of radionecrosis (P=0.010 and 0.036, respectively).

CONCLUSION

Adjuvant hypofractionated stereotactic radiosurgery to the postoperative cavity in patients with brain metastases results in excellent local control in selected patients, helps delay the use of whole brain radiation, and is associated with a relatively low risk of radionecrosis.