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2.
Science ; 384(6702): eadh5548, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38900896

ABSTRACT

The molecular mechanisms that regulate breast cancer cell (BCC) metastasis and proliferation within the leptomeninges (LM) are poorly understood, which limits the development of effective therapies. In this work, we show that BCCs in mice can invade the LM by abluminal migration along blood vessels that connect vertebral or calvarial bone marrow and meninges, bypassing the blood-brain barrier. This process is dependent on BCC engagement with vascular basement membrane laminin through expression of the neuronal pathfinding molecule integrin α6. Once in the LM, BCCs colocalize with perivascular meningeal macrophages and induce their expression of the prosurvival neurotrophin glial-derived neurotrophic factor (GDNF). Intrathecal GDNF blockade, macrophage-specific GDNF ablation, or deletion of the GDNF receptor neural cell adhesion molecule (NCAM) from BCCs inhibits breast cancer growth within the LM. These data suggest integrin α6 and the GDNF signaling axis as new therapeutic targets against breast cancer LM metastasis.


Subject(s)
Bone Neoplasms , Breast Neoplasms , Integrin alpha6 , Meningeal Neoplasms , Meninges , Neural Pathways , Animals , Female , Humans , Mice , Basement Membrane/metabolism , Bone Neoplasms/secondary , Bone Neoplasms/metabolism , Breast Neoplasms/pathology , Breast Neoplasms/metabolism , Breast Neoplasms/genetics , Cell Line, Tumor , Cell Movement , Glial Cell Line-Derived Neurotrophic Factor/genetics , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Integrin alpha6/metabolism , Laminin/metabolism , Macrophages/metabolism , Meningeal Neoplasms/metabolism , Meningeal Neoplasms/secondary , Meninges/pathology , Neoplasm Invasiveness , Neural Cell Adhesion Molecules/metabolism , Neural Cell Adhesion Molecules/genetics , Signal Transduction , Neural Pathways/metabolism , Mice, SCID , Mice, Knockout
3.
medRxiv ; 2024 May 15.
Article in English | MEDLINE | ID: mdl-38798534

ABSTRACT

Importance: Development of new therapies in melanoma has increased survival, and as a result more patients are living to develop brain metastasis (BrM). Identifying patients at increased risk of BrM is therefore of significant public health importance. Objective: To determine whether history of atopy is associated with improved survival or reduced incidence of BrM in cutaneous melanoma. Design: A retrospective cohort study conducted from June 2022 to March 2024. Setting: Population-based in states with Surveillance, Epidemiology and End Results (SEER) supported cancer registries. Participants: Individuals (≥65 years) diagnosed with cutaneous melanoma between January 1, 2008 and December 31, 2017 that are participants in traditional Medicare. Exposures: Individuals were compared that had history of atopy (allergic rhinitis, atopic dermatitis, asthma, and/or allergic/atopic conjunctivitis) diagnosed prior to melanoma diagnosis, ascertained using ICD-9 or ICD-10 codes in Medicare claims. Main Outcomes and Measures: Primary endpoints were diagnosis with a BrM or death during the follow-up period. Associations between atopy and endpoints were assessed using cox proportional hazards models to estimate hazard ratios (HR) and p-values. Results: A total of 29,956 cutaneous melanoma cases were identified (median age 76, 60% male and 97% non-Hispanic White). Overall, 7.1% developed BrM during follow up. Among the 35% that had history of atopy, the most common condition was atopic dermatitis (19%). After adjustment for demographic and prognostic factors, atopy was associated with a 16% decrease in death (HR=0.84 [95%CI:0.80-0.87], pFDR<0.001). Among those with non-metastatic disease at time of diagnosis, atopy conferred a 15% decrease in cumulative incidence BrM (HR=0.85 [95%CI: 0.76-0.94], pFDR=0.006), with a 25% decrease associated with atopic dermatitis (HR=0.75 [95%CI:0.65-0.86], pFDR<0.001). Among those with metastatic disease at diagnosis (any metastatic site), only those who received immune checkpoint inhibitors had a survival benefit associated with atopy (HR=0.31, [95%CI:0.15-0.64], p=0.001 vs HR=1.41, [95%CI:0.87-2.27], p=0.165). Conclusions and Relevance: Atopy, particularly atopic dermatitis, was significantly associated with improved survival and decreased incidence of BrM. The improved survival associated with these conditions in the context of immunotherapy suggests that these conditions in the elderly may identify those with more robust immune function that may be more responsive to treatment.

4.
Adv Radiat Oncol ; 9(6): 101475, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38690297

ABSTRACT

Purpose: Clinical and imaging surveillance of patients with brain metastases is important after stereotactic radiosurgery (SRS) because many will experience intracranial progression (ITCP) requiring multidisciplinary management. The prognostic significance of neurologic symptoms at the time of ITCP is poorly understood. Methods and Materials: This was a multi-institutional, retrospective cohort study from 2015 to 2020, including all patients with brain metastases completing an initial course of SRS. The primary outcome was overall survival (OS) by presence of neurologic symptoms at ITCP. OS, freedom from ITCP (FF-ITCP), and freedom from symptomatic ITCP (FF-SITCP) were assessed via Kaplan-Meier method. Cox proportional hazard models tested parameters impacting FF-ITCP and FF-SITCP. Results: Among 1383 patients, median age was 63.4 years, 55% were female, and common primaries were non-small cell lung (49%), breast (15%), and melanoma (9%). At a median follow-up of 8.72 months, asymptomatic and symptomatic ITCP were observed in 504 (36%) and 194 (14%) patients, respectively. The majority of ITCP were distant ITCP (79.5%). OS was worse with SITCP (median, 10.2 vs 17.9 months, P < .001). SITCP was associated with clinical factors including total treatment volume (P = .012), melanoma histology (P = .001), prior whole brain radiation therapy (P = .003), number of brain metastases (P < .001), interval of 1 to 2 years from primary and brain metastasis diagnosis (P = .012), controlled extracranial disease (P = .042), and receipt of pre-SRS chemotherapy (P = .015). Patients who were younger and received post-SRS chemotherapy (P = .001), immunotherapy (P < .001), and targeted or small-molecule inhibitor therapy (P < .026) had better FF-SITCP. Conclusions: In this cohort study of patients with brain metastases completing SRS, neurologic symptoms at ITCP is prognostic for OS. This data informs post-SRS surveillance in clinical practice as well as future prospective studies needed in the modern management of brain metastases.

5.
J Neurosurg ; : 1-11, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-38457795

ABSTRACT

OBJECTIVE: Meningiomas are the most common primary brain tumors in adults and a subset are aggressive lesions resistant to standard therapies. Laser interstitial thermal therapy (LITT) has been successfully applied to other brain tumors, and recent work aims to explore the safety and long-term outcome experiences of LITT for both new and recurrent meningiomas. The authors' objective was to report safety and outcomes data of the largest cohort of LITT-treated meningioma patients to date. METHODS: Eight United States-based hospitals enrolled patients with meningioma in the Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System (LAANTERN) prospective multicenter registry and/or contributed additional retrospective enrollments for this cohort study. Demographic, procedural, safety, and outcomes data were collected and analyzed using standard statistical methods. RESULTS: Twenty adult patients (12 prospective and 8 retrospective) with LITT-targeted meningiomas were accrued. Patients underwent LITT for new (6 patients) and recurrent (14 patients) tumors (ranging from the 1st to 12th recurrence). The 30-day complication rate was 10%. Twenty percent of patients (4/20) had exhausted all other treatment options. Median length of follow-up was 1.3 years. One-third of new (2/6) and one-half of recurrent (7/14) meningiomas had disease progression during follow-up. One-year estimated local control (LC), progression-free survival, and overall survival rates were 55.3%, 48.4%, and 86.3%, respectively. In the 12 patients who had ≥ 91% ablative coverage, 1-year estimated LC was 61.4%. The complication rate was 10% (2/20), with 1 complication being transient and resolving postoperatively. CONCLUSIONS: This cohort study supports the safety of the procedure for this tumor type. LITT can offer a much-needed treatment option, especially for patients with multiply recurrent meningiomas who have limited remaining alternatives.

6.
J Neurooncol ; 167(1): 219-227, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38340295

ABSTRACT

PURPOSE: During stereotactic radiosurgery (SRS) planning for brain metastases (BM), brain MRIs are reviewed to select appropriate targets based on radiographic characteristics. Some BM are difficult to detect and/or definitively identify and may go untreated initially, only to become apparent on future imaging. We hypothesized that in patients receiving multiple courses of SRS, reviewing the initial planning MRI would reveal early evidence of lesions that developed into metastases requiring SRS. METHODS: Patients undergoing two or more courses of SRS to BM within 6 months between 2016 and 2018 were included in this single-institution, retrospective study. Brain MRIs from the initial course were reviewed for lesions at the same location as subsequently treated metastases; if present, this lesion was classified as a "retrospectively identified metastasis" or RIM. RIMs were subcategorized as meeting or not meeting diagnostic imaging criteria for BM (+ DC or -DC, respectively). RESULTS: Among 683 patients undergoing 923 SRS courses, 98 patients met inclusion criteria. There were 115 repeat courses of SRS, with 345 treated metastases in the subsequent course, 128 of which were associated with RIMs found in a prior MRI. 58% of RIMs were + DC. 17 (15%) of subsequent courses consisted solely of metastases associated with + DC RIMs. CONCLUSION: Radiographic evidence of brain metastases requiring future treatment was occasionally present on brain MRIs from prior SRS treatments. Most RIMs were + DC, and some subsequent SRS courses treated only + DC RIMs. These findings suggest enhanced BM detection might enable earlier treatment and reduce the need for additional SRS.


Subject(s)
Brain Neoplasms , Radiosurgery , Humans , Radiosurgery/methods , Retrospective Studies , Incidence , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/radiotherapy , Brain Neoplasms/pathology , Magnetic Resonance Imaging
7.
Neuro Oncol ; 26(6): 1152-1162, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38170451

ABSTRACT

BACKGROUND: Laser interstitial thermal therapy (LITT) of intracranial tumors or radiation necrosis enables tissue diagnosis, cytoreduction, and rapid return to systemic therapies. Ablated tissue remains in situ, resulting in characteristic post-LITT edema associated with transient clinical worsening and complicating post-LITT response assessment. METHODS: All patients receiving LITT at a single center for tumors or radiation necrosis from 2015 to 2023 with ≥9 months of MRI follow-up were included. An nnU-Net segmentation model was trained to automatically segment contrast-enhancing lesion volume (CeLV) of LITT-treated lesions on T1-weighted images. Response assessment was performed using volumetric measurements. RESULTS: Three hundred and eighty four unique MRI exams of 61 LITT-treated lesions and 6 control cases of medically managed radiation necrosis were analyzed. Automated segmentation was accurate in 367/384 (95.6%) images. CeLV increased to a median of 68.3% (IQR 35.1-109.2%) from baseline at 1-3 months from LITT (P = 0.0012) and returned to baseline thereafter. Overall survival (OS) for LITT-treated patients was 39.1 (9.2-93.4) months. Lesion expansion above 40% from volumetric nadir or baseline was considered volumetric progression. Twenty-one of 56 (37.5%) patients experienced progression for a volumetric progression-free survival of 21.4 (6.0-93.4) months. Patients with volumetric progression had worse OS (17.3 vs 62.1 months, P = 0.0015). CONCLUSIONS: Post-LITT CeLV expansion is quantifiable and resolves within 6 months of LITT. Development of response assessment criteria for LITT-treated lesions is feasible and should be considered for clinical trials. Automated lesion segmentation could speed the adoption of volumetric response criteria in clinical practice.


Subject(s)
Brain Neoplasms , Laser Therapy , Humans , Female , Male , Laser Therapy/methods , Brain Neoplasms/pathology , Brain Neoplasms/diagnostic imaging , Middle Aged , Magnetic Resonance Imaging/methods , Adult , Neural Networks, Computer , Aged , Follow-Up Studies , Retrospective Studies , Prognosis , Hyperthermia, Induced/methods , Deep Learning
8.
World Neurosurg ; 180: e449-e459, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37769846

ABSTRACT

OBJECTIVE: Preoperative assessment is important for neurosurgical risk stratification, but the level of evidence for individual screening tests is low. In preoperative urinalysis (UA), testing may significantly increase costs and lead to inappropriate antibiotic treatment. We prospectively evaluated whether eliminating preoperative UA was noninferior to routine preoperative UA as measured by 30-day readmission for surgical site infection in adult elective neurosurgical procedures. METHODS: A single-institution prospective, pragmatic study of patients receiving elective neurosurgical procedures from 2018 to 2020 was conducted. Patients were allocated based on same-day versus preoperative admission status. Rates of preoperative UA and subsequent wound infection were measured along with detailed demographic, surgical, and laboratory data. RESULTS: The study included 879 patients. The most common types of surgery were cranial (54.7%), spine (17.4%), and stereotactic/functional (19.5%). No preoperative UA was performed in 315 patients, while 564 underwent UA. Of tested patients, 103 (18.3%) met criteria for suspected urinary tract infection, and 69 (12.2%) received subsequent antibiotic treatment. There were 14 patients readmitted within 30 days (7 without UA [2.2%] vs. 7 with UA [1.2%]) for subsequent wound infection with a risk difference of 0.98% (95% confidence interval -0.89% to 2.85%). The upper limit of the confidence interval exceeded the preselected noninferiority margin of 1%. CONCLUSIONS: In this prospective study of preoperative UA for elective neurosurgical procedures using a pragmatic, real-world design, risk of readmission due to surgical site infection was very low across the study cohort, suggesting a limited role of preoperative UA for elective neurosurgical procedures.


Subject(s)
Surgical Wound Infection , Urinary Tract Infections , Adult , Humans , Surgical Wound Infection/diagnosis , Surgical Wound Infection/epidemiology , Surgical Wound Infection/prevention & control , Prospective Studies , Urinalysis , Anti-Bacterial Agents/therapeutic use , Spine , Urinary Tract Infections/diagnosis , Urinary Tract Infections/etiology , Urinary Tract Infections/prevention & control
9.
Nat Cancer ; 4(9): 1258-1272, 2023 09.
Article in English | MEDLINE | ID: mdl-37537301

ABSTRACT

The accepted paradigm for both cellular and anti-tumor immunity relies upon tumor cell killing by CD8+ T cells recognizing cognate antigens presented in the context of target cell major histocompatibility complex (MHC) class I (MHC-I) molecules. Likewise, a classically described mechanism of tumor immune escape is tumor MHC-I downregulation. Here, we report that CD8+ T cells maintain the capacity to kill tumor cells that are entirely devoid of MHC-I expression. This capacity proves to be dependent instead on interactions between T cell natural killer group 2D (NKG2D) and tumor NKG2D ligands (NKG2DLs), the latter of which are highly expressed on MHC-loss variants. Necessarily, tumor cell killing in these instances is antigen independent, although prior T cell antigen-specific activation is required and can be furnished by myeloid cells or even neighboring MHC-replete tumor cells. In this manner, adaptive priming can beget innate killing. These mechanisms are active in vivo in mice as well as in vitro in human tumor systems and are obviated by NKG2D knockout or blockade. These studies challenge the long-advanced notion that downregulation of MHC-I is a viable means of tumor immune escape and instead identify the NKG2D-NKG2DL axis as a therapeutic target for enhancing T cell-dependent anti-tumor immunity against MHC-loss variants.


Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Animals , Humans , Mice , Antigens/metabolism , CD8-Positive T-Lymphocytes/pathology , Histocompatibility Antigens Class I/genetics , Histocompatibility Antigens Class I/metabolism , Neoplasms/genetics , NK Cell Lectin-Like Receptor Subfamily K/genetics , NK Cell Lectin-Like Receptor Subfamily K/metabolism
11.
Clin Cancer Res ; 29(16): 3214-3224, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37327318

ABSTRACT

PURPOSE: Laser interstitial thermal therapy (LITT) is an effective minimally invasive treatment option for intracranial tumors. Our group produced plasmonics-active gold nanostars (GNS) designed to preferentially accumulate within intracranial tumors and amplify the ablative capacity of LITT. EXPERIMENTAL DESIGN: The impact of GNS on LITT coverage capacity was tested in ex vivo models using clinical LITT equipment and agarose gel-based phantoms of control and GNS-infused central "tumors." In vivo accumulation of GNS and amplification of ablation were tested in murine intracranial and extracranial tumor models followed by intravenous GNS injection, PET/CT, two-photon photoluminescence, inductively coupled plasma mass spectrometry (ICP-MS), histopathology, and laser ablation. RESULTS: Monte Carlo simulations demonstrated the potential of GNS to accelerate and specify thermal distributions. In ex vivo cuboid tumor phantoms, the GNS-infused phantom heated 5.5× faster than the control. In a split-cylinder tumor phantom, the GNS-infused border heated 2× faster and the surrounding area was exposed to 30% lower temperatures, with margin conformation observed in a model of irregular GNS distribution. In vivo, GNS preferentially accumulated within intracranial tumors on PET/CT, two-photon photoluminescence, and ICP-MS at 24 and 72 hours and significantly expedited and increased the maximal temperature achieved in laser ablation compared with control. CONCLUSIONS: Our results provide evidence for use of GNS to improve the efficiency and potentially safety of LITT. The in vivo data support selective accumulation within intracranial tumors and amplification of laser ablation, and the GNS-infused phantom experiments demonstrate increased rates of heating, heat contouring to tumor borders, and decreased heating of surrounding regions representing normal structures.


Subject(s)
Brain Neoplasms , Hyperthermia, Induced , Humans , Animals , Mice , Gold , Positron Emission Tomography Computed Tomography , Brain Neoplasms/surgery , Hyperthermia, Induced/methods , Lasers
12.
Surg Neurol Int ; 14: 138, 2023.
Article in English | MEDLINE | ID: mdl-37151451

ABSTRACT

Background: Meningiomas are the most common primary central nervous system neoplasm in the United States. While the majority of meningiomas are benign, the World Health Organization (WHO) Grade I tumors, a not-insignificant proportion of tumors are in anatomically complex locations or demonstrate more aggressive phenotypes, presenting a challenge for local disease control with surgery and radiation. Laser interstitial thermal therapy (LITT) consists of stereotactic delivery of laser light for tumor ablation and is minimally invasive, requiring implantation of a laser fiber through a cranial burr hole. Herein, we demonstrate the first use of this technology in a progressive atypical sphenoid wing meningioma for a previously resected and irradiated tumor. Case Description: A 47-year-old female was diagnosed with a left-sided atypical meningioma, the WHO 2, of the sphenoid wing following acute worsening of bitemporal headache and dizziness. Given neurovascular involvement, a subtotal resection was performed, followed by stereotactic radiosurgery. Following progression 9 months from resection, the patient elected to proceed with LITT. The patient's postoperative course was uncomplicated and she remains progression free at 24 months following LITT. Conclusion: We present the first use of LITT for a sphenoid wing meningioma documented in the literature, which demonstrated enhanced disease control for a lesion that was refractory to both surgery and radiation. LITT could represent an additional option for local control of progressive meningiomas, even in locations that are challenging to access surgically. More evidence is needed regarding the technical nuances of LITT for lesions of the skull base.

13.
Neurooncol Adv ; 5(1): vdad035, 2023.
Article in English | MEDLINE | ID: mdl-37207119

ABSTRACT

Background: The nervous and immune systems interact in a reciprocal manner, both under physiologic and pathologic conditions. Literature spanning various CNS pathologies including brain tumors, stroke, traumatic brain injury and de-myelinating diseases describes a number of associated systemic immunologic changes, particularly in the T-cell compartment. These immunologic changes include severe T-cell lymphopenia, lymphoid organ contraction, and T-cell sequestration within the bone marrow. Methods: We performed an in-depth systematic review of the literature and discussed pathologies that involve brain insults and systemic immune derangements. Conclusions: In this review, we propose that the same immunologic changes hereafter termed 'systemic immune derangements', are present across CNS pathologies and may represent a novel, systemic mechanism of immune privilege for the CNS. We further demonstrate that systemic immune derangements are transient when associated with isolated insults such as stroke and TBI but persist in the setting of chronic CNS insults such as brain tumors. Systemic immune derangements have vast implications for informed treatment modalities and outcomes of various neurologic pathologies.

15.
Adv Radiat Oncol ; 8(2): 101166, 2023.
Article in English | MEDLINE | ID: mdl-36845614

ABSTRACT

Purpose: Hypofractionated stereotactic radiosurgery (HF-SRS) with or without surgical resection is potentially a preferred treatment for larger or symptomatic brain metastases (BMs). Herein, we report clinical outcomes and predictive factors following HF-SRS. Methods and Materials: Patients undergoing HF-SRS for intact (iHF-SRS) or resected (rHF-SRS) BMs from 2008 to 2018 were retrospectively identified. Linear accelerator-based image-guided HF-SRS consisted of 5 fractions at 5, 5.5, or 6 Gy per fraction. Time to local progression (LP), time to distant brain progression (DBP), and overall survival (OS) were calculated. Cox models assessed effect of clinical factors on OS. Fine and Gray's cumulative incidence model for competing events examined effect of factors on LP and DBP. The occurrence of leptomeningeal disease (LMD) was determined. Logistic regression examined predictors of LMD. Results: Among 445 patients, median age was 63.5 years; 87% had Karnofsky performance status ≥70. Fifty-three % of patients underwent surgical resection, and 75% received 5 Gy per fraction. Patients with resected BMs had higher Karnofsky performance status (90-100, 41 vs 30%), less extracranial disease (absent, 25 vs 13%), and fewer BMs (multiple, 32 vs 67%). Median diameter of the dominant BM was 3.0 cm (interquartile range, 1.8-3.6 cm) for intact BMs and 4.6 cm (interquartile range, 3.9-5.5 cm) for resected BMs. Median OS was 5.1 months (95% confidence interval [CI], 4.3-6.0) following iHF-SRS and 12.8 months (95% CI, 10.8-16.2) following rHF-SRS (P < .01). Cumulative LP incidence was 14.5% at 18 months (95% CI, 11.4-18.0%), significantly associated with greater total GTV (hazard ratio, 1.12; 95% CI, 1.05-1.20) following iFR-SRS, and with recurrent versus newly diagnosed BMs across all patients (hazard ratio, 2.28; 95% CI, 1.01-5.15). Cumulative DBP incidence was significantly greater following rHF-SRS than iHF-SRS (P = .01), with respective 24-month rates of 50.0 (95% CI, 43.3-56.3) and 35.7% (95% CI, 29.2-42.2). LMD (57 events total; 33% nodular, 67% diffuse) was observed in 17.1% of rHF-SRS and 8.1% of iHF-SRS cases (odds ratio, 2.46; 95% CI, 1.34-4.53). Any radionecrosis and grade 2+ radionecrosis events were observed in 14 and 8% of cases, respectively. Conclusions: HF-SRS demonstrated favorable rates of LC and radionecrosis in postoperative and intact settings. Corresponding LMD and RN rates were comparable to those of other studies.

16.
Neurosurgery ; 93(1): 198-205, 2023 07 01.
Article in English | MEDLINE | ID: mdl-36790207

ABSTRACT

BACKGROUND: The management of intracranial oncological disease remains a significant challenge despite advances in systemic cancer therapy. Laser interstitial thermal therapy (LITT) represents a novel treatment for local control of brain tumors through photocoagulation with a stereotactically implanted laser fiber. Because the use of laser interstitial thermal therapy continues to increase within neurosurgery, characterization of LITT is necessary to improve outcomes. OBJECTIVE: To quantify the risk of tumor seeding along the laser fiber tract in patients receiving LITT for primary or metastatic brain tumors at a high-volume treatment center. METHODS: We retrospectively reviewed all patients receiving LITT from 2015 to 2021 at our medical center. Patients with biopsy-confirmed tumors were included in this study. Tract seeding was identified as discontinuous, newly enhancing tumor along the LITT tract. RESULTS: Fifty-six patients received LITT for biopsy-confirmed tumors from 2015 to 2021, with tract seeding identified in 3 (5.4%). Twenty-nine (51.8%) patients had gliomas, while the remainder had metastases, of which lung was the most common histology (20 patients, 74%). Tract seeding was associated with ablation proceeding inward from superficial tumor margin closest to the cranial entry point ( P = .03). Patients with tract seeding had a shorter median time to progression of 1.1 (0.1-1.3) months vs 4.2 (2.2-8.6) months ( P = .03). CONCLUSION: Although the risk of tract seeding after LITT is reassuringly low, it is associated with decreased progression-free survival. This risk may be related to surgical technique or experience. Follow-up radiosurgery to the LITT tract has the potential to prevent this complication.


Subject(s)
Brain Neoplasms , Laser Therapy , Humans , Retrospective Studies , Brain Neoplasms/pathology , Progression-Free Survival , Laser Therapy/methods , Lasers
17.
Int J Radiat Oncol Biol Phys ; 115(3): 779-793, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36289038

ABSTRACT

PURPOSE: We sought to develop a computer-aided detection (CAD) system that optimally augments human performance, excelling especially at identifying small inconspicuous brain metastases (BMs), by training a convolutional neural network on a unique magnetic resonance imaging (MRI) data set containing subtle BMs that were not detected prospectively during routine clinical care. METHODS AND MATERIALS: Patients receiving stereotactic radiosurgery (SRS) for BMs at our institution from 2016 to 2018 without prior brain-directed therapy or small cell histology were eligible. For patients who underwent 2 consecutive courses of SRS, treatment planning MRIs from their initial course were reviewed for radiographic evidence of an emerging metastasis at the same location as metastases treated in their second SRS course. If present, these previously unidentified lesions were contoured and categorized as retrospectively identified metastases (RIMs). RIMs were further subcategorized according to whether they did (+DC) or did not (-DC) meet diagnostic imaging-based criteria to definitively classify them as metastases based upon their appearance in the initial MRI alone. Prospectively identified metastases (PIMs) from these patients, and from patients who only underwent a single course of SRS, were also included. An open-source convolutional neural network architecture was adapted and trained to detect both RIMs and PIMs on thin-slice, contrast-enhanced, spoiled gradient echo MRIs. Patients were randomized into 5 groups: 4 for training/cross-validation and 1 for testing. RESULTS: One hundred thirty-five patients with 563 metastases, including 72 RIMS, met criteria. For the test group, CAD sensitivity was 94% for PIMs, 80% for +DC RIMs, and 79% for PIMs and +DC RIMs with diameter <3 mm, with a median of 2 false positives per patient and a Dice coefficient of 0.79. CONCLUSIONS: Our CAD model, trained on a novel data set and using a single common MR sequence, demonstrated high sensitivity and specificity overall, outperforming published CAD results for small metastases and RIMs - the lesion types most in need of human performance augmentation.


Subject(s)
Brain Neoplasms , Deep Learning , Radiosurgery , Humans , Retrospective Studies , Radiosurgery/methods , Magnetic Resonance Imaging/methods , Brain Neoplasms/secondary
18.
Front Neurol ; 14: 1322815, 2023.
Article in English | MEDLINE | ID: mdl-38259649

ABSTRACT

Background: Peritumoral edema alters diffusion anisotropy, resulting in false negatives in tractography reconstructions negatively impacting surgical decision-making. With supratotal resections tied to survival benefit in glioma patients, advanced diffusion modeling is critical to visualize fibers within the peritumoral zone to prevent eloquent fiber transection thereafter. A preoperative assessment paradigm is therefore warranted to systematically evaluate multi-subject tractograms along clinically meaningful parameters. We propose a novel noninvasive surgically-focused survey to evaluate the benefits of a tractography algorithm for preoperative planning, subsequently applied to Synaptive Medical's free-water correction algorithm developed for clinically feasible single-shell DTI data. Methods: Ten neurosurgeons participated in the study and were presented with patient datasets containing histological lesions of varying degrees of edema. They were asked to compare standard (uncorrected) tractography reconstructions overlaid onto anatomical images with enhanced (corrected) reconstructions. The raters assessed the datasets in terms of overall data quality, tract alteration patterns, and the impact of the correction on lesion definition, brain-tumor interface, and optimal surgical pathway. Inter-rater reliability coefficients were calculated, and statistical comparisons were made. Results: Standard tractography was perceived as problematic in areas proximal to the lesion, presenting with significant tract reduction that challenged assessment of the brain-tumor interface and of tract infiltration. With correction applied, significant reduction in false negatives were reported along with additional insight into tract infiltration. Significant positive correlations were shown between favorable responses to the correction algorithm and the lesion-to-edema ratio, such that the correction offered further clarification in increasingly edematous and malignant lesions. Lastly, the correction was perceived to introduce false tracts in CSF spaces and - to a lesser degree - the grey-white matter interface, highlighting the need for noise mitigation. As a result, the algorithm was modified by free-water-parameterizing the tractography dataset and introducing a novel adaptive thresholding tool for customizable correction guided by the surgeon's discretion. Conclusion: Here we translate surgeon insights into a clinically deployable software implementation capable of recovering peritumoral tracts in edematous zones while mitigating artifacts through the introduction of a novel and adaptive case-specific correction tool. Together, these advances maximize tractography's clinical potential to personalize surgical decisions when faced with complex pathologies.

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