Executive Summary of the American Radium Society Appropriate Use Criteria for Brain Metastases in EGFR-mutated and ALK-fusion Non-Small Cell Lung Cancer.

BACKGROUND: The American Radium Society (ARS) Central Nervous System (CNS) committee reviewed literature on epidermal growth factor receptor mutated (EGFRm) and ALK-fusion (ALK+) tyrosine kinase inhibitors (TKIs) for the treatment of brain metastases (BrMs) from non-small cell lung cancers (NSCLC) to generate appropriate use guidelines addressing use of TKIs in conjunction with or in lieu of radiotherapy (RT). METHODS: The panel developed three key questions to guide systematic review: can radiotherapy be deferred in patients receiving EGFR or ALK TKIs at 1) diagnosis or 2) recurrence? Should TKI be administered concurrently with RT (3)? Two literature searches were performed (May 2019 and December 2023). The panel developed 8 model cases and voted on treatment options using a 9-point scale, with 1-3, 4-6 and 7-9 corresponding to usually not appropriate, may be appropriate, and usually appropriate (respectively), per the UCLA/RAND Appropriateness Method. RESULTS: Consensus was achieved in only 4 treatment scenarios, all consistent with existing ARS-AUC guidelines for multiple BrM. The panel did not reach consensus that RT can be appropriately deferred in patients with BrM receiving CNS penetrant ALK or EGFR TKIs, though median scores indicated deferral may be appropriate under most circumstances. Whole brain RT with concurrent TKI generated broad disagreement except in cases with 2-4 BrM, where it was considered usually not appropriate. CONCLUSIONS: We identified no definitive studies dictating optimal sequencing of TKIs and RT for EGFRm and ALK+ BrM. Until such studies are completed, the committee hopes these cases guide decision-making in this complex clinical space.

National Cancer Institute Collaborative Workshop on Shaping the Landscape of Brain Metastases Research: challenges and recommended priorities.

Brain metastases are an increasing global public health concern, even as survival rates improve for patients with metastatic disease. Both metastases and the sequelae of their treatment are key determinants of the inter-related priorities of patient survival, function, and quality of life, mandating a multidimensional approach to clinical care and research. At a virtual National Cancer Institute Workshop in September, 2022, key stakeholders convened to define research priorities to address the crucial areas of unmet need for patients with brain metastases to achieve meaningful advances in patient outcomes. This Policy Review outlines existing knowledge gaps, collaborative opportunities, and specific recommendations regarding consensus priorities and future directions in brain metastases research. Achieving major advances in research will require enhanced coordination between the ongoing efforts of individual organisations and consortia. Importantly, the continual and active engagement of patients and patient advocates will be necessary to ensure that the directionality of all efforts reflects what is most meaningful in the context of patient care.

Patterns of Progression in Patients With Newly Diagnosed Glioblastoma Treated With 5-mm Margins in a Phase 1/2 Trial of 5-Fraction Stereotactic Radiosurgery With Concurrent and Adjuvant Temozolomide.

PURPOSE: In patients with newly diagnosed glioblastoma (GBM), tumor margins of at least 20 mm are the standard of care. We sought to determine the pattern of tumor progression in patients treated with 5-fraction stereotactic radiosurgery with 5-mm margins. METHODS AND MATERIALS: Thirty adult patients with newly diagnosed GBM were treated with 5-fraction stereotactic radiosurgery in escalated doses from 25 to 40 Gy with a 5-mm total treatment margin. Progression was scored as "in-field" if the recurrent tumor was within or contiguous with the 5-mm margin, "marginal" if between 5 and 20 mm, and "distant" if entirely occurring greater than 20 mm. As geometric patterns of progression do not reflect the biologic dose received, we calculated the minimum equi-effective dose in 2 Gy (EQD2) per day at the site of tumor recurrence. Progression was "dosimetrically in-field" if covered by a minimum EQD2 per day of 48 Gy10. RESULTS: From 2010 to 2016, 27 patients had progressed. Progression was in-field in 17 (63%), marginal in 3 (11%), and distant in 7 (26%) patients. In the 3 patients with marginal progression, the minimum EQD2 to recurrent tumor were 48 Gy10, 56 Gy10 (both considered dosimetrically in-field), and 7 Gy10 (ie, dosimetrically out-of-field). Median overall survival was 12.1 months for in-field (95% confidence interval [CI], 8.9-17.6), 15.1 months (95% CI, 10.1 to not achieved) for marginal, and 21.4 months (95% CI, 11.2-33.5) for distant progression. Patients with radiation necrosis were less likely to have in-field progression (1 of 7; 14%) compared with those without radiation necrosis (16 of 20; 80%; P = .003); those with necrosis had a median overall survival of 27.2 months (95% CI, 11.2-48.3) compared with 11.7 months (95% CI, 8.9-17.6) for patients with no necrosis (P = .077). CONCLUSIONS: In patients with newly diagnosed GBM treated with a 5-mm clinical target volume margin, 3 patients (11%) had marginal progression within 5 to 20 mm; only 1 patient (4%) may have dosimetrically benefitted from conventional 20-mm margins. Radiation necrosis was associated with in-field tumor control.

A Protocol for Reducing Intensive Care Utilization After Craniotomy: A 3-Year Assessment.

BACKGROUND: Craniotomy patients have traditionally received intensive care unit (ICU) care postoperatively. Our institution developed the "Non-Intensive CarE" (NICE) protocol to identify craniotomy patients who did not require postoperative ICU care. OBJECTIVE: To determine the longitudinal impact of the NICE protocol on postoperative length of stay (LOS), ICU utilization, readmissions, and complications. METHODS: In this retrospective cohort study, our institution's electronic medical record was queried to identify craniotomies before protocol deployment (May 2014-May 2018) and after deployment (May 2018-December 2021). The primary end points were average postoperative LOS and ICU utilization; secondary end points included readmissions, reoperation, and postoperative complications rate. End points were compared between pre- and postintervention cohorts. RESULTS: Four thousand eight hundred thirty-seven craniotomies were performed from May 2014 to December 2021 (2302 preprotocol and 2535 postprotocol). Twenty-one percent of postprotocol craniotomies were enrolled in the NICE protocol. After protocol deployment, the overall postoperative LOS decreased from 4.0 to 3.5 days ( P = .0031), which was driven by deceased postoperative LOS among protocol patients (average 2.4 days). ICU utilization decreased from 57% of patients to 42% ( P < .0001), generating ∼$760 000 in savings. Return to the ICU and complications decreased after protocol deployment. 5.8% of protocol patients had a readmission within 30 days; none could have been prevented through ICU stay. CONCLUSION: The NICE protocol is an effective, sustainable method to increase ICU bed availability and decrease costs without changing outcomes. To our knowledge, this study features the largest series of patients enrolling in an ICU utilization reduction protocol. Careful patient selection is a requirement for the success of this approach.

Biliary cancer brain metastases: a multi-institution case series with case reports.

Background: Biliary cancers are rare, and few reported cases of brain metastases from primary biliary cancers exist, especially describing patients in the United States. This report assesses the proportion and incidence of brain metastases arising from primary biliary cancers [cholangiocarcinoma (CCA) and gallbladder cancer] at Stanford University and the University of California, San Francisco, describes clinical characteristics, and provides a case series. Methods: We queried 3 clinical databases at Stanford and the University of California, San Francisco to retrospectively identify and review the charts of 15 patients with brain metastases from primary biliary cancers occurring between 1990 to 2020. Results: Among patients with brain metastases analyzed at Stanford (3,585), 6 had a primary biliary cancer, representing 0.17% of all brain metastases. Among biliary cancer patients at the University of California, San Francisco (1,055), 9 had brain metastases, representing an incidence in biliary cancer of 0.85%. A total of 15 biliary cancer patients with brain metastases were identified at the two institutions. Thirteen out of 15 patients (86.7%, 95% CI: 59.5-98.3) were female. The median overall survival from primary biliary cancer diagnosis was 214 days (95% CI: 71.69-336.82 days) and subsequent OS from the time of brain metastasis diagnosis was 57 days (95% CI: 13.43-120.64 days). Death within 90 days of brain metastasis diagnosis occurred in 66.67% of patients (95% CI: 38.38-88.17). Conclusions: Brain metastases from primary biliary cancers are rare, with limited survival once diagnosed. This report can aid health care providers in caring for patients with brain metastases from primary biliary cancers.

Executive summary of American Radium Society's appropriate use criteria for the postoperative management of lower grade gliomas.

Postoperative management of lower grade gliomas (grade 2 and 3) is heterogeneous. The American Radium Society's brain malignancies panel systematically reviewed and evaluated the literature to develop consensus guidelines addressing timing of postoperative therapy, monotherapy versus combined modality therapy, type of chemotherapy used with radiotherapy, and radiotherapy dose. Thirty-six studies were included. Using consensus methodology (modified Delphi), the panel voted upon representative case variants using a 9-point appropriateness scale to address key questions. Voting results were collated to develop summarized recommendations. Following gross-total surgical resection, close surveillance is appropriate for well-selected grade 2, IDH-mutant oligodendrogliomas or astrocytomas with low-risk features. For grade 2 gliomas with high-risk features or any grade 3 glioma, immediate adjuvant therapy is recommended. When postoperative therapy is administered, radiation and planned chemotherapy is strongly recommended over monotherapy. For grade 2 and 3 IDH-mutant oligodendrogliomas and astrocytomas, either adjunctive PCV (procarbazine, lomustine, vincristine) or temozolomide is appropriate. For grade 3 IDH-mutant astrocytomas, radiotherapy followed by temozolomide is strongly recommended. The recommended radiotherapy dose for grade 2 gliomas is 45-54 Gy/1.8-2.0 Gy, and for grade 3 gliomas is 59.4-60 Gy/1.8-2.0 Gy. While multiple appropriate treatment options exist, these consensus recommendations provide an evidence-based framework to approach postoperative management of lower grade gliomas.

Aberrant promoter methylation contributes to LRIG1 silencing in basal/triple-negative breast cancer.

BACKGROUND: LRIG1, the founding member of the LRIG (leucine-rich repeat and immunoglobulin-like domain) family of transmembrane proteins, is a negative regulator of receptor tyrosine kinases and a tumour suppressor. Decreased LRIG1 expression is consistently observed in cancer, across diverse tumour types, and is linked to poor patient prognosis. However, mechanisms by which LRIG1 is repressed are not fully understood. Silencing of LRIG1 through promoter CpG island methylation has been reported in colorectal and cervical cancer but studies in breast cancer remain limited. METHODS: In silico analysis of human breast cancer patient data were used to demonstrate a correlation between DNA methylation and LRIG1 silencing in basal/triple-negative breast cancer, and its impact on patient survival. LRIG1 gene expression, protein abundance, and methylation enrichment were examined by quantitative reverse-transcription PCR, immunoblotting, and methylation immunoprecipitation, respectively, in breast cancer cell lines in vitro. We examined the impact of global demethylation on LRIG1 expression and methylation enrichment using 5-aza-2'-deoxycytidine. We also examined the effects of targeted demethylation of the LRIG1 CpG island, and transcriptional activation of LRIG1 expression, using the RNA guided deadCas9 transactivation system. RESULTS: Across breast cancer subtypes, LRIG1 expression is lowest in the basal/triple-negative subtype so we investigated whether differential methylation may contribute to this. Indeed, we find that LRIG1 CpG island methylation is most prominent in basal/triple-negative cell lines and patient samples. Use of the global demethylating agent 5-aza-2'-deoxycytidine decreases methylation leading to increased LRIG1 transcript expression in basal/triple-negative cell lines, while having no effect on LRIG1 expression in luminal/ER-positive cell lines. Using a CRISPR/deadCas9 (dCas9)-based targeting approach, we demonstrate that TET1-mediated demethylation (Tet1-dCas9) along with VP64-mediated transcriptional activation (VP64-dCas9) at the CpG island, increased endogenous LRIG1 expression in basal/triple-negative breast cancer cells, without transcriptional upregulation at predicted off-target sites. Activation of LRIG1 by the dCas9 transactivation system significantly increased LRIG1 protein abundance, reduced site-specific methylation, and reduced cancer cell viability. Our findings suggest that CRISPR-mediated targeted activation may be a feasible way to restore LRIG1 expression in cancer. CONCLUSIONS: Our study contributes novel insight into mechanisms which repress LRIG1 in triple-negative breast cancer and demonstrates for the first time that targeted de-repression of LRIG1 in cancer cells is possible. Understanding the epigenetic mechanisms associated with repression of tumour suppressor genes holds potential for the advancement of therapeutic approaches.

Factors for Differential Outcome Across Cancers in Clinical Molecule-Targeted Fluorescence Imaging.

Clinical imaging performance using a fluorescent antibody was compared across 3 cancers to elucidate physical and biologic factors contributing to differential translation of epidermal growth factor receptor (EGFR) expression to macroscopic fluorescence in tumors. Methods: Thirty-one patients with high-grade glioma (HGG, n = 5), head-and-neck squamous cell carcinoma (HNSCC, n = 23), or lung adenocarcinoma (LAC, n = 3) were systemically infused with 50 mg of panitumumab-IRDye800 1-3 d before surgery. Intraoperative open-field fluorescent images of the surgical field were acquired, with imaging device settings and operating room lighting conditions being tested on tissue-mimicking phantoms. Fluorescence contrast and margin size were measured on resected specimen surfaces. Antibody distribution and EGFR immunoreactivity were characterized in macroscopic and microscopic histologic structures. The integrity of the blood-brain barrier was examined via tight junction protein (Claudin-5) expression with immunohistochemistry. Stepwise multivariate linear regression of biologic variables was performed to identify independent predictors of panitumumab-IRDye800 concentration in tissue. Results: Optimally acquired at the lowest gain for tumor detection with ambient light, intraoperative fluorescence imaging enhanced tissue-size dependent tumor contrast by 5.2-fold, 3.4-fold, and 1.4-fold in HGG, HNSCC, and LAC, respectively. Tissue surface fluorescence target-to-background ratio correlated with margin size and identified 78%-97% of at-risk resection margins ex vivo. In 4-µm-thick tissue sections, fluorescence detected tumor with 0.85-0.89 areas under the receiver-operating-characteristic curves. Preferential breakdown of blood-brain barrier in HGG improved tumor specificity of intratumoral antibody distribution relative to that of EGFR (96% vs. 80%) despite its reduced concentration (3.9 ng/mg of tissue) compared with HNSCC (8.1 ng/mg) and LAC (6.3 ng/mg). Cellular EGFR expression, tumor cell density, plasma antibody concentration, and delivery barrier were independently associated with local intratumoral panitumumab-IRDye800 concentration, with 0.62 goodness of fit of prediction. Conclusion: In multicancer clinical imaging of a receptor-ligand-based molecular probe, plasma antibody concentration, delivery barrier, and intratumoral EGFR expression driven by cellular biomarker expression and tumor cell density led to heterogeneous intratumoral antibody accumulation and spatial distribution whereas tumor size, resection margin, and intraoperative imaging settings substantially influenced macroscopic tumor contrast.

A Novel Brain-Permeant Chemotherapeutic Agent for the Treatment of Brain Metastasis in Triple-Negative Breast Cancer.

Development of metastases to central nervous system (CNS) is an increasing clinical issue following the diagnosis of advanced breast cancer. The propensity to metastasize to CNS varies by breast cancer subtype. Of the four breast cancer subtypes, triple-negative breast cancers (TNBC) have the highest rates of both parenchymal brain metastasis and leptomeningeal metastasis (LM). LM is rapidly fatal due to poor detection and limited therapeutic options. Therapy of TNBC brain metastasis and LM is challenged by multifocal brain metastasis and diffuse spread of LM, and must balance brain penetration, tumor cytotoxicity, and the avoidance of neurotoxicity. Thus, there is an urgent need for novel therapeutic options in TNBCs CNS metastasis. QBS10072S is a novel chemotherapeutic that leverages TNBC-specific defects in DNA repair and LAT1 (L-amino acid transporter type 1)-dependent transport into the brain. In our study, activity of QBS10072S was investigated in vitro with various cell lines including the human TNBC cell line MDA-MB-231 and its brain-tropic derivative MDA-MB-231-BR3. QBS10072S was preferentially toxic to TNBC cells. The efficacy of QBS10072S against brain metastasis and LM was tested using a model of brain metastasis based on the internal carotid injection of luciferase-expressing tumor cells into NuNu mice. The compound was well tolerated, delayed tumor growth and reduced leptomeningeal dissemination, resulting in significant extension of survival. Given that current treatments for LM are palliative with only few studies reporting a survival benefit, QBS10072S is planned to be investigated in clinical trials as a therapeutic for TNBC LM. SIGNIFICANCE: TNBC brain metastasis often involves dissemination into leptomeninges. Treatment options for TNBC leptomeningeal metastasis are limited and are mostly palliative. Our study demonstrates significant efficacy of the brain-penetrating agent QBS10072S against TNBC brain metastasis and leptomeningeal spread.

A Novel Protocol for Reducing Intensive Care Utilization After Craniotomy.

BACKGROUND: There is a growing body of evidence suggesting not all craniotomy patients require postoperative intensive care. OBJECTIVE: To devise and implement a standardized protocol for craniotomy patients eligible to transition directly from the operating room to the ward-the Non-Intensive CarE (NICE) protocol. METHODS: We preoperatively identified patients undergoing elective craniotomy for simple neurosurgical procedures with age <65 yr and American Society of Anesthesiologists (ASA) class of 1, 2 or 3. Postoperative eligibility was confirmed by the surgical and anesthesia teams. Upon arrival to the ward, patients were staffed with a neuroscience nurse for hourly neurological examinations for the first 8 h. Patient demographics, clinical characteristics, and outcomes were prospectively collected to evaluate the NICE protocol. RESULTS: From February 2018 to 2019, 63 patients were included in the NICE protocol with a median age of 46 yr and 65% female predominance. Of the operations performed, 38.1% were microvascular decompressions, 31.7% were craniotomy for tumor, 15.9% were cavernous malformation resections, and 14.3% were Chiari decompressions. No patients required transfer to the intensive care unit (ICU). Median length of stay was 2 d. There was an 11.1% overall readmission rate within the median follow-up period of 48 d. Three patients (4.8%) required reoperation at time of readmission within the follow-up period (1 postoperative subdural hematoma, 2 cerebrospinal fluid leak repair). None of these complications could have been identified with a postoperative ICU stay. CONCLUSION: In our pilot trial of the NICE protocol, no patients required postoperative transfer to the ICU.

Financial Toxicity in Patients with Brain and Spine Metastases.

OBJECTIVE: Financial toxicity associated with cancer treatment has a deleterious impact on patient outcomes but has not been well characterized among patients with metastatic cancers. We characterize the extent of financial toxicity among this population and identify factors associated with financial toxicity. METHODS: We prospectively surveyed adult patients with brain and spine metastases who received radiosurgery at a large academic medical center between January 2018 and December 2019. Financial toxicity was measured with the Personal Financial Wellness (PFW) scale. RESULTS: In total, 93 patients were included, with a median survival of 17.7 months. Most patients had private insurance (47%) or Medicare with supplementary insurance (42%), whereas 11% of patients were uninsured or insured by Medicaid/Medicare/Veterans Affairs. Of patients, 60% were primary income earners, of whom 52% had dependents. The median PFW score was 7.0 (interquartile range, 5.1-9.1), with financial toxicity reported in 23 patients (25%). After adjusting for age and education level, private insurance (odds ratio [OR], 0.28; P = 0.080) was associated with a lower likelihood of financial toxicity. Having ≥1 emergency department visit (OR, 3.87; P = 0.024) and a cancer-related change in employment status (OR, 3.63; P = 0.036) were associated with greater likelihood of reporting financial toxicity. CONCLUSIONS: Most patients with cancer with brain and spine metastases with a poor prognosis treated at a tertiary center are primary income earners and experience financial toxicity. Further studies are warranted to assess the longitudinal impact of financial toxicity in patients with metastatic cancer, particularly those with ≥1 emergency department visit and a cancer-related change in employment status.

Re-evaluating Biopsy for Recurrent Glioblastoma: A Position Statement by the Christopher Davidson Forum Investigators.

Patients with glioblastoma (GBM) need bold new approaches to their treatment, yet progress has been hindered by a relative inability to dynamically track treatment response, mechanisms of resistance, evolution of targetable mutations, and changes in mutational burden. We are writing on behalf of a multidisciplinary group of academic neuro-oncology professionals who met at the collaborative Christopher Davidson Forum at Washington University in St Louis in the fall of 2019. We propose a dramatic but necessary change to the routine management of patients with GBM to advance the field: to routinely biopsy recurrent GBM at the time of presumed recurrence. Data derived from these samples will identify true recurrence vs treatment effect, avoid treatments with little chance of success, enable clinical trial access, and aid in the scientific advancement of our understanding of GBM.

Stereotactic Radiosurgery After Resection of Brain Metastases: Changing Patterns of Care in the United States.

OBJECTIVE: Management of symptomatic brain metastases often includes surgical resection with postoperative radiotherapy. Postoperative whole-brain radiotherapy (WBRT) improves intracranial control but detrimentally impacts quality of life and neurocognition. We sought to characterize the use in the United States of postoperative stereotactic radiosurgery (SRS), an evolving standard-of-care associated with reduced cognitive effects. METHODS: With the MarketScan Commercial Claims and Encounters Database from 2007 to 2015, we identified patients aged 18-65 years treated with resection of a brain metastasis followed by SRS or WBRT within 60 days of surgery. Logistic regression estimated associations between co-variables (treatment year, age, sex, geographic region, place of service, insurance type, disease histology, comorbidity score, and median area household income and educational attainment) and SRS receipt. RESULTS: Of 4007 patients included, 1506 (37.6%) received SRS and 2501 (62.4%) received WBRT. Postoperative SRS increased from 16.5% (2007-2008) to 56.8% (2014-2015). Patients residing in areas with a median household income or an educational attainment below 50th percentile were significantly less likely to receive SRS after controlling for treatment year and other demographic characteristics (P < 0.01). Factors associated with greater odds of receiving SRS included younger age, female sex, melanoma histology, Western region location, hospital-based facility, and high-deductible health plan enrollment (P < 0.05 for each). CONCLUSIONS: Postoperative SRS for brain metastases has increased from 2007 to 2015, with the majority of patients now receiving SRS over WBRT. Patients in areas of lower socioeconomic class were less likely to receive SRS, warranting further investigation of barriers to SRS adoption.

Intracranial Tumor Control After Immune-Related Adverse Events and Discontinuation of Immunotherapy for Melanoma.

OBJECTIVE: Immunotherapy for patients with melanoma with brain metastasis has significantly improved outcomes; however, it has also been characterized by potentially dangerous immune-related adverse events (IRAEs). Several reports have suggested that these reactions can precede improved treatment responses. For intracranial disease control, we sought to identify if such an association exists. METHODS: We conducted a retrospective chart review of patients with melanoma who underwent immunotherapy treatment after diagnosis of brain metastasis. The study cohort was then stratified into 2 groups based on their history of developing an IRAE that prompted discontinuation of that regimen. The primary outcome variable included intracranial progression-free survival (PFS). Kaplan-Meier and Cox proportional hazard analyses were used to evaluate survival and predictors of outcomes. RESULTS: Fifty-two patients met the inclusion criteria, 17 of whom experienced severe IRAEs that led to discontinuation of immunotherapy. Median intracranial PFS was 19.9 versus 10.5 months (P = 0.053) in patients who did and did not experience severe IRAEs prompting discontinuation, respectively. No additional outcome benefits were identified for systemic PFS or overall survival (mean, 33.1 months and 27.6 months, respectively). Multivariable analysis identified BRAF mutation status as a negative prognosticator of brain progression (P = 0.013; hazard ratio, 3.90). Initial treatment with BRAF inhibitor was also a negative predictor of all-cause mortality (P = 0.015; hazard ratio, 10.73). CONCLUSIONS: Immune-related adverse events may signify an underlying immunogenic response that has intracranial disease control benefits. Despite their associated side effects, immunotherapies continue to show promising outcomes as a first-line agent for melanoma with brain metastasis.

Executive summary from American Radium Society's appropriate use criteria on neurocognition after stereotactic radiosurgery for multiple brain metastases.

BACKGROUND: The American Radium Society (ARS) Appropriate Use Criteria brain malignancies panel systematically reviewed (PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses]) published literature on neurocognitive outcomes after stereotactic radiosurgery (SRS) for patients with multiple brain metastases (BM) to generate consensus guidelines. METHODS: The panel developed 4 key questions (KQs) to guide systematic review. From 11 614 original articles, 12 were selected. The panel developed model cases addressing KQs and potentially controversial scenarios not addressed in the systematic review (which might inform future ARS projects). Based upon quality of evidence, the panel confidentially voted on treatment options using a 9-point scale of appropriateness. RESULTS: The panel agreed that SRS alone is usually appropriate for those with good performance status and 2-10 asymptomatic BM, and usually not appropriate for >20 BM. For 11-15 and 16-20 BM there was (between 2 case variants) agreement that SRS alone may be appropriate or disagreement on the appropriateness of SRS alone. There was no scenario (among 6 case variants) in which conventional whole-brain radiotherapy (WBRT) was considered usually appropriate by most panelists. There were several areas of disagreement, including: hippocampal sparing WBRT for 2-4 asymptomatic BM; WBRT for resected BM amenable to SRS; fractionated versus single-fraction SRS for resected BM, larger targets, and/or brainstem metastases; optimal treatment (WBRT, hippocampal sparing WBRT, SRS alone to all or select lesions) for patients with progressive extracranial disease, poor performance status, and no systemic options. CONCLUSIONS: For patients with 2-10 BM, SRS alone is an appropriate treatment option for well-selected patients with good performance status. Future study is needed for those scenarios in which there was disagreement among panelists.

Stereotactic Radiosurgery for Resected Brain Metastases: Does the Surgical Corridor Need to be Targeted?

PURPOSE: Although consensus guidelines for postresection stereotactic radiosurgery (SRS) for brain metastases recommend the surgical corridor leading to the resection cavity be included in the SRS plan, no study has reported patterns of tumor recurrence based on inclusion or exclusion of the corridor as a target. We reviewed tumor control and toxicity outcomes of postresection SRS for deep brain metastases based on whether or not the surgical corridor was targeted. MATERIALS AND METHODS: We retrospectively reviewed patients who had resected brain metastases treated with SRS between 2007 and 2018 and included only "deep" tumors (defined as located ≥1.0 cm from the pial surface before resection). RESULTS: In 66 deep brain metastases in 64 patients, the surgical corridor was targeted in 43 (65%). There were no statistical differences in the cumulative incidences of progression at 12 months for targeting versus not targeting the corridor, respectively, for overall local failure 2% (95% confidence interval [CI], 0%-11%) versus 9% (95% CI, 1%-25%; P = .25), corridor failure 0% (95% CI, 0%-0%) versus 9% (95% CI, 1%-25%; P = .06), cavity failure 2% (95% CI, 0%-11%) versus 0% (95% CI, 0%-0%; P = .91), and adverse radiation effect 5% (95% CI, 1%-15%) versus 13% (95% CI, 3%-30%; P = .22). Leptomeningeal disease (7%; 95% CI, 2%-18%) versus 26% (95% CI, 10%-45%; P = .03) was higher in those without the corridor targeted. CONCLUSIONS: Omitting the surgical corridor in postoperative SRS for resected brain metastases was not associated with statistically significant differences in corridor or cavity recurrence or adverse radiation effect. As seen in recent prospective trials of postresection SRS, the dominant pattern of progression is within the resection cavity; omission of the corridor would yield a smaller SRS volume that could allow for dose escalation to potentially improve local cavity control.

Costs and Complications Associated With Resection of Supratentorial Tumors With and Without the Operative Microscope in the United States.

BACKGROUND: The operative microscope, a commonly used tool in neurosurgery, is critical in many supratentorial tumor cases. However, use of operating microscope for supratentorial tumor varies by surgeon. OBJECTIVES: To assess complication rates, readmissions, and costs associated with operative microscope use in supratentorial resections. METHODS: A retrospective analysis was conducted using a national administrative database to identify patients with glioma or brain metastases who underwent supratentorial resection between 2007 and 2016. Univariate and multivariate analyses were used to assess 30-day complications, readmissions, and costs between patients who underwent resection with and without use of microscope. RESULTS: The cohort included 12,058 glioma patients and 5433 metastasis patients. Rates of microscope use varied by state from 19.0% to 68.6%. Microscope use was associated with $5228.90 in additional costs of index hospitalization among glioma patients (P <0.001), and $2824.00 among metastasis patients (P <0.001). Rates of intraoperative cerebral edema were lower among the microscope cohort than among the nonmicroscope cohort (P <0.027). Microscope use was associated with a slight reduction in 30-day rates of neurological complications (14.7% vs. 16.7%, P = 0.048), specifically in nonspecific cerebrovascular complications. There were no differences in rates of other complications, readmissions, or 30-day postoperative costs. CONCLUSIONS: Use of operative microscope for supratentorial resections varies by state and is associated with higher cost of surgery. Microscope use may be associated with lower rates of intraoperative cerebral edema and some cerebrovascular complications, but is not associated with significant differences in other complications, readmissions, or 30-day costs.

Nodular Leptomeningeal Disease-A Distinct Pattern of Recurrence After Postresection Stereotactic Radiosurgery for Brain Metastases: A Multi-institutional Study of Interobserver Reliability.

PURPOSE: For brain metastases, surgical resection with postoperative stereotactic radiosurgery is an emerging standard of care. Postoperative cavity stereotactic radiosurgery is associated with a specific, underrecognized pattern of intracranial recurrence, herein termed nodular leptomeningeal disease (nLMD), which is distinct from classical leptomeningeal disease. We hypothesized that there is poor consensus regarding the definition of LMD, and that a formal, self-guided training module will improve interrater reliability (IRR) and validity in diagnosing LMD. METHODS AND MATERIALS: Twenty-two physicians at 16 institutions, including 15 physicians with central nervous system expertise, completed a 2-phase survey that included magnetic resonance imaging and treatment information for 30 patients. In the "pretraining" phase, physicians labeled cases using 3 patterns of recurrence commonly reported in prospective studies: local recurrence (LR), distant parenchymal recurrence (DR), and LMD. After a self-directed training module, participating physicians completed the "posttraining" phase and relabeled the 30 cases using the 4 following labels: LR, DR, classical leptomeningeal disease, and nLMD. RESULTS: IRR increased 34% after training (Fleiss' Kappa K = 0.41 to K = 0.55, P < .001). IRR increased most among non-central nervous system specialists (+58%, P < .001). Before training, IRR was lowest for LMD (K = 0.33). After training, IRR increased across all recurrence subgroups and increased most for LMD (+67%). After training, ≥27% of cases initially labeled LR or DR were later recognized as nLMD. CONCLUSIONS: This study highlights the large degree of inconsistency among clinicians in recognizing nLMD. Our findings demonstrate that a brief self-guided training module distinguishing nLMD can significantly improve IRR across all patterns of recurrence, and particularly in nLMD. To optimize outcomes reporting, prospective trials in brain metastases should incorporate central imaging review and investigator training.

Outcomes and Costs Following Ommaya Placement with Thrombocytopenia Among U.S. Patients with Cancer.

BACKGROUND: Placement of Ommaya reservoirs for the administration of intrathecal chemotherapy may be complicated by comorbid thrombocytopenia among patients with hematologic or leptomeningeal disease. Aggregated data on risks of Ommaya placement among thrombocytopenic patients are lacking. This study assesses complications, revision rates, and costs associated with Ommaya placement among patients with thrombocytopenia in a large population sample. METHODS: Using a national administrative database, this retrospective study identifies a cohort of adult patients with cancer who underwent Ommaya placement between 2007 and 2016. Preoperative thrombocytopenia was defined as diagnosis of secondary thrombocytopenia, bleeding event, procedure to control bleeding, or platelet transfusion, within 30 days before index admission. Univariate and multivariate analyses were performed to assess costs, 30-day complications, readmissions, and revisions among patients with and without preoperative thrombocytopenia. RESULTS: The analytic cohort included 1652 patients, of whom 29.3% met criteria for preoperative thrombocytopenia. In-hospital mortality rates were 7.7% among patients thrombocytopenia with versus 1.2% among patients without thrombocytopenia (P < 0.001). Preoperative thrombocytopenia was associated with 14.5 times greater hazard of intracranial hemorrhage within 30 days following Ommaya placement, occurring in 25.6% versus 2.0% of patients with and without thrombocytopenia, respectively (P < 0.014). Revision rates did not differ significantly between patients with and without thrombocytopenia. Thrombocytopenia was associated with longer length of stay (7.4 vs. 13.9 days, P < 0.001) and additional $10,000 per patient in costs of index hospitalization (P < 0.001). CONCLUSIONS: This is the largest study to date documenting costs and complication rates of Ommaya placement in patients with and without thrombocytopenia.

Difference-Frequency Ultrasound Imaging With Non-Linear Contrast.

Conventional ultrasound imaging is based on the scattering of sound from inhomogeneities in the density and the speed of sound and is often used in medicine to resolve pathologic compared to normal tissue. Here we demonstrate a difference-frequency ultrasound (dfUS) imaging method that is based on the interaction of two sound pulses that propagate non-collinearly and intersect in space and time. The dfUS signal arises primarily from the second-order non-linear coefficient, a contrast mechanism that differs from linear and harmonic US imaging. The distinct contrast mechanism allows dfUS to image anatomic features that are not identifiable in conventional US images of salmon and pig kidney tissue. Further, dfUS produces enhanced contrast of glioblastoma tumor implanted in the mouse brain, revealing its potential for improving medical diagnosis. Progress towards a real-time system is discussed.