Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20.142
Filtrar
2.
Gan To Kagaku Ryoho ; 48(7): 963-965, 2021 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-34267037

RESUMO

The prognosis of patients with brain metastasis is very poor. Very few cases of combined treatment with nivolumab(240 mg/body, day 1, q2w, a programmed cell death-1[PD-1]inhibitor)and gamma knife radiosurgery(GKR)(27 Gy/3 Fr) for gastric cancer patients with brain metastasis have been reported. Here, we discuss the case of a 55-year-old man with HER2-positive poorly differentiated gastric adenocarcinoma with multiple bone and intra-abdominal lymph node metastases. After 25 courses of SOX(oxaliplatin 100 mg/m2, day 1, q3w plus S-1 120 mg/day, day 1-14, po, q3w)plus trastuzumab( 6 mg/kg, q3w)treatment, brain metastasis was detected. Subsequently, combined treatment with GKR and nivolumab(8 courses, anti-PD-1 monotherapy)was initiated. Both intra-abdominal and brain lesions decreased in response to this treatment, showing that combined therapy with nivolumab and GKR could be effective for treating gastric cancer patients with brain metastasis.


Assuntos
Adenocarcinoma , Neoplasias Encefálicas , Radiocirurgia , Neoplasias Gástricas , Adenocarcinoma/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Nivolumabe/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia
3.
J Clin Neurosci ; 90: 238-243, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275556

RESUMO

Laser interstitial thermal therapy (LITT) is a minimally invasive neurosurgical technique that has been demonstrated to successfully ablate intracranial tumors. While LITT for supratentorial lesions can often be straightforward, ablation of infratentorial lesions can be difficult with current targeting technologies and instrumentation. The anatomical difficulty of targeting posterior fossa masses can be further complicated in patients who have had a prior craniectomy or other procedure that removed the bone that is required to set the surgical trajectory. This article describes use of a three-dimensional (3D)-printed customized surgical implant to improve and enable targeting of posterior fossa lesions using LITT, particularly in the setting of prior craniectomy. A 3D-printed implant was customized for a patient with a history of metastatic lung cancer and prior posterior fossa craniectomy who presented for treatment of a progressively enlarging contrast-enhancing lesion in the right cerebellar hemisphere. The device included a built-in bolt trajectory for LITT ablation. The temporary implant was successfully fabricated for use with laser ablation of a right cerebellar mass. Three potential trajectories for the LITT bolt were incorporated into the temporary implant, but only the primary trajectory was utilized. Laser ablation was performed with the implant and a SideFire laser probe. Customized 3D-printed implants can enable the use of LITT for patients who would not otherwise be candidates.


Assuntos
Neoplasias Encefálicas/cirurgia , Terapia a Laser/instrumentação , Procedimentos Neurocirúrgicos/instrumentação , Impressão Tridimensional , Cirurgia Assistida por Computador/instrumentação , Idoso , Humanos , Hipertermia Induzida/instrumentação , Hipertermia Induzida/métodos , Terapia a Laser/métodos , Masculino
4.
J Clin Neurosci ; 90: 68-75, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275583

RESUMO

BACKGROUND: This study was performed to investigate the safety and outcome of one-stage hybrid endovascular and microsurgical treatment of intracranial hypervascular tumors. METHODS: The blood supply of the tumor was endovascularly embolized just before microsurgery in a one-stage fashion. Clinical data regarding the preoperative neurological status, tumor characteristics, hybrid treatment details and complications, intraoperative blood loss, and postoperative outcomes were collected prospectively and then analyzed. RESULTS: Beginning in July 2016, 13 patients (5 women, 8 men) with intracranial hypervascular tumors were enrolled in this study, with a mean age of 48.2 ± 10.9 years. The patients' tumors comprised seven hemangioblastomas, three hemangiopericytomas, two meningiomas, and one mesenchymal chondrosarcoma. The mean maximum tumor diameter was 54.9 ± 21.5 mm. No major procedural complications occurred except catheterization-related bleeding in one patient. The mean percentage of tumor devascularization was 65.0%±17.5%. Gross total resection was achieved in 12 patients (92.3%). The mean blood loss volume during microsurgical resection was 703.8 ± 886.8 mL (range, 150-3600 mL). Symptoms improved in three patients and remained stable in six patients. CONCLUSIONS: One-stage hybrid embolization before intracranial hypervascular tumor resection is a safe and effective procedure to decrease intraoperative blood loss. It can prevent or treat embolization-related complications in a timely manner and avoid the risk of multiple surgical procedures.


Assuntos
Neoplasias Encefálicas/cirurgia , Hemangioblastoma/cirurgia , Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Microcirurgia/métodos , Procedimentos Neurocirúrgicos/métodos , Adulto , Embolização Terapêutica/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
Clin Ter ; 172(4): 315-321, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34247214

RESUMO

Background: This study aimed to determine the diagnostic per-formance of fractional anisotropy (FA) and mean diffusivity (MD) values for glioma grading. Conclusion: The tMD, rMDt/w, and rFAp/w values represent useful indices for the differentiation between LGG and HGG. The combination of these indices can improve diagnostic specificity. Methods: A total of 42 patients who underwent biopsy or surge-ry and were histologically diagnosed with glioma from September 2019 to December 2020 were enrolled in this retrospective study. Diffusion tensor imaging (DTI) and conventional magnetic resonance imaging (MRI) were performed preoperatively using 3 Tesla MRI in all cases. The FA and MD values were measured in the solid portion of the tumor, the peritumoral area, and the normal white matter. The diagnostic performances of the absolute and relative FA and MD values for glioma grading were analyzed using the receiver operating characteristic (ROC) curve. Results: The MD value in the solid portion of the tumor (tMD), the MD value of the solid portion of the tumor relative to that in the normal white matter (rMDt/w), and the FA value for the peritumoral region relative to that of the normal white matter (rFAp/w) showed significant differences between the low-grade (LGG) and high-grade glioma (HGG) groups. The combination of these three parameters provided the largest area under the curve value of 89% with sensitivity, specificity, accuracy, negative predictive, and positive predictive values of 72%, 100%, 81%, 62%, and 100%, respectively, for distinguishing between the LGG and HGG groups.


Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/fisiopatologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Glioma/diagnóstico , Glioma/fisiopatologia , Gradação de Tumores/métodos , Adolescente , Adulto , Anisotropia , Neoplasias Encefálicas/cirurgia , Criança , Feminino , Glioma/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
6.
Medicine (Baltimore) ; 100(25): e26432, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34160432

RESUMO

BACKGROUND: Glioblastoma multiforme (GBM) owes an ominous prognosis: its mean overall survival is 14 months. The extent of surgical resection (ESR) highlights among factors in which an association has been found to a somewhat better prognosis. However, the association between greater ESR and prolonged overall (OS) survival is not a constant finding nor a proven cause-and-effect phenomenon. To our objective is to establish the strength of association between ESR and OS in patients with GBM through a systematic review and meta-analysis. METHODS: In accordance with PRISMA-P recommendations, we conducted a systematic literature search; we included studies with adult patients who had undergone craniotomy for GBM. Our primary outcome is overall postoperative survival at 12 and 24 months. We reviewed 180 studies, excluded 158, and eliminated 8; 14 studies that suited our requirements were analyzed. RESULTS: The initial level of evidence of all studies is low, and it may be degraded to very low according to GRADE criteria because of design issues. The definition of different levels of the extent of resection is heterogeneous and poorly defined. We found a great amount of variation in the methodology of the operation and the adjuvant treatment protocol. The combined result for relative risk (RR) for OS for 12 months analysis is 1.25 [95% confidence interval (95% CI) 1.14-1.36, P < .01], absolute risk reduction (ARR) of 15.7% (95% CI 11.9-19.4), relative risk reduction (RRR) of 0.24 (95% CI 0.18-0.31), number needed to treat (NNT) 6; for 24-month analysis RR is 1.59 (95% CI 1.11-2.26, P < .01) ARR of 11.5% (95% CI 7.7-15.1), relative risk reduction (RRR) of 0.53 (95% CI 0.33-0.76), (NNT) 9. In each term analysis, the proportion of alive patients who underwent more extensive resection is significantly higher than those who underwent subtotal resection. CONCLUSION: Our results sustain a weak but statistically significant association between the ESR and OS in patients with GBM obtained from observational studies with a very low level of evidence according to GRADE criteria. As a consequence, any estimate of effect is very uncertain. Current information cannot sustain a cause-and-effect relationship between these variables.


Assuntos
Neoplasias Encefálicas/cirurgia , Glioblastoma/cirurgia , Procedimentos Neurocirúrgicos/métodos , Neoplasias Encefálicas/mortalidade , Glioblastoma/mortalidade , Humanos , Estudos Observacionais como Assunto , Prognóstico , Intervalo Livre de Progressão , Medição de Risco/estatística & dados numéricos
7.
J Clin Neurosci ; 89: 279-282, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34119281

RESUMO

Awake craniotomy is an established procedure for resecting brain tumors in eloquent lesions, and intraoperative seizure is one of the most important complications. Phenytoin is normally used to control intraoperative seizures. Recently, phenytoin was replaced with levetiracetam at our institution because the latter has fewer side effects. While the phenytoin dose is calibrated in accordance with the serum concentration, there is currently no consensus on a method of monitoring the serum concentration of levetiracetam or the effective concentration range needed to control intraoperative seizures during awake craniotomy. The present study therefore aimed to determine whether monitoring the serum levetiracetam concentration is useful for controlling intraoperative seizures during awake craniotomy. The intraoperative serum concentration of levetiracetam during awake craniotomy was measured in 34 patients and compared with that of phenytoin in 33 patients undergoing the same procedure. The levetiracetam concentration inversely correlated with body surface area (BSA) and estimated glomerular filtration rate (eGFR). Levetiracetam was superior to phenytoin in terms of the correlation between the serum concentration and the dose adjusted for BSA and eGFR (correlation coefficient, 0.49 vs 0.21). Furthermore, the serum levetiracetam concentration in patients with intraoperative seizures was below the 95% confidence interval (CI) of the regression line whereas the serum phenytoin concentration of two patients with seizures was within the 95% CI, indicating that evaluating the serum levetiracetam concentration against the BSA and eGFR-adjusted dosage may be useful in preventing intraoperative seizures during awake craniotomy by allowing prediction of the seizure risk and enabling more accurate dosage calibration.


Assuntos
Anticonvulsivantes/sangue , Craniotomia/métodos , Levetiracetam/sangue , Convulsões/tratamento farmacológico , Vigília , Adulto , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/uso terapêutico , Neoplasias Encefálicas/cirurgia , Humanos , Levetiracetam/efeitos adversos , Levetiracetam/uso terapêutico , Pessoa de Meia-Idade , Fenitoína/efeitos adversos , Fenitoína/sangue , Fenitoína/uso terapêutico , Convulsões/prevenção & controle
8.
Theranostics ; 11(15): 7222-7234, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34158846

RESUMO

Background: Frozen section and smear preparation are the current standard for intraoperative histopathology during cancer surgery. However, these methods are time-consuming and subject to limited sampling. Multiphoton microscopy (MPM) is a high-resolution non-destructive imaging technique capable of optical sectioning in real time with subcellular resolution. In this report, we systematically investigated the feasibility and translation potential of MPM for rapid histopathological assessment of label- and processing-free surgical specimens. Methods: We employed a customized MPM platform to capture architectural and cytological features of biological tissues based on two-photon excited NADH and FAD autofluorescence and second harmonic generation from collagen. Infiltrating glioma, an aggressive disease that requires subcellular resolution for definitive characterization during surgery, was chosen as an example for this validation study. MPM images were collected from resected brain specimens of 19 patients and correlated with histopathology. Deep learning was introduced to assist with image feature recognition. Results: MPM robustly captures diagnostic features of glioma including increased cellularity, cellular and nuclear pleomorphism, microvascular proliferation, necrosis, and collagen deposition. Preliminary application of deep learning to MPM images achieves high accuracy in distinguishing gray from white matter and cancer from non-cancer. We also demonstrate the ability to obtain such images from intact brain tissue with a multiphoton endomicroscope for intraoperative application. Conclusion: Multiphoton imaging correlates well with histopathology and is a promising tool for characterization of cancer and delineation of infiltration within seconds during brain surgery.


Assuntos
Neoplasias Encefálicas , Encéfalo , Glioma , Cuidados Intraoperatórios , Microscopia de Fluorescência por Excitação Multifotônica , Neoplasias Experimentais , Adulto , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Linhagem Celular Tumoral , Glioma/diagnóstico por imagem , Glioma/cirurgia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/cirurgia
9.
Theranostics ; 11(15): 7130-7143, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34158840

RESUMO

Rationale: First-line therapy for high-grade gliomas (HGGs) includes maximal safe surgical resection. The extent of resection predicts overall survival, but current neuroimaging approaches lack tumor specificity. The epidermal growth factor receptor (EGFR) is a highly expressed HGG biomarker. We evaluated the safety and feasibility of an anti-EGFR antibody, panitumuab-IRDye800, at subtherapeutic doses as an imaging agent for HGG. Methods: Eleven patients with contrast-enhancing HGGs were systemically infused with panitumumab-IRDye800 at a low (50 mg) or high (100 mg) dose 1-5 days before surgery. Near-infrared fluorescence imaging was performed intraoperatively and ex vivo, to identify the optimal tumor-to-background ratio by comparing mean fluorescence intensities of tumor and histologically uninvolved tissue. Fluorescence was correlated with preoperative T1 contrast, tumor size, EGFR expression and other biomarkers. Results: No adverse events were attributed to panitumumab-IRDye800. Tumor fragments as small as 5 mg could be detected ex vivo and detection threshold was dose dependent. In tissue sections, panitumumab-IRDye800 was highly sensitive (95%) and specific (96%) for pathology confirmed tumor containing tissue. Cellular delivery of panitumumab-IRDye800 was correlated to EGFR overexpression and compromised blood-brain barrier in HGG, while normal brain tissue showed minimal fluorescence. Intraoperative fluorescence improved optical contrast in tumor tissue within and beyond the T1 contrast-enhancing margin, with contrast-to-noise ratios of 9.5 ± 2.1 and 3.6 ± 1.1, respectively. Conclusions: Panitumumab-IRDye800 provided excellent tumor contrast and was safe at both doses. Smaller fragments of tumor could be detected at the 100 mg dose and thus more suitable for intraoperative imaging.


Assuntos
Neoplasias Encefálicas , Sistemas de Liberação de Medicamentos , Glioma , Indóis/administração & dosagem , Proteínas de Neoplasias/metabolismo , Imagem Óptica , Panitumumabe/administração & dosagem , Adulto , Idoso , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/cirurgia , Intervalo Livre de Doença , Receptores ErbB/metabolismo , Feminino , Glioma/diagnóstico por imagem , Glioma/metabolismo , Glioma/cirurgia , Humanos , Cuidados Intraoperatórios , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida
10.
Acta Neurochir Suppl ; 128: 51-55, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191061

RESUMO

Symptomatic epilepsy is frequently encountered in patients with brain metastases (BM), affecting up to 25% of them. However, it generally remains unknown whether the risk of seizures in such cases is affected by stereotactic radiosurgery (SRS), which involves highly conformal delivery of high-dose irradiation to the tumor with a minimal effect on adjacent brain tissue. Thus, the role of prophylactic administration of antiepileptic drugs (AED) after SRS remains controversial. A comprehensive review and analysis of the available literature reveals that according to prospective studies, the incidence of seizures after SRS for BM varies from 8% to 22%, and there is no evidence that SRS increases the incidence of symptomatic epilepsy. Therefore, routine prophylactic administration of AED prior to, during, or after SRS in the absence of a seizure history is not recommended. Nevertheless, short-course administration of an AED may be judiciously considered (on the basis of class III evidence) for selected high-risk individuals.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/cirurgia , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Convulsões/etiologia , Convulsões/prevenção & controle
11.
Acta Neurochir Suppl ; 128: 57-69, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191062

RESUMO

Approximately 25-35% of all cancer patients suffer from brain metastases (BM), and many of them-in particular, those with a limited number of intracranial tumors-are treated with stereotactic radiosurgery (SRS). Accurate prediction of survival remains a key clinical challenge in this population. Several prognostic scales have been developed to facilitate this prognostication, including the Recursive Partitioning Analysis (RPA) classification, the modified Recursive Partitioning Analysis (mRPA) subclassifications, the Basic Score for Brain Metastases (BS-BM), the Score Index for Radiosurgery (SIR), the Graded Prognostic Assessment (GPA), and the diagnosis-specific Graded Prognostic Assessment (dsGPA). However, none of these scales include consideration of the cumulative intracranial tumor volume (CITV), which is defined as the sum of all intracranial tumor volumes. Since there is mounting evidence that the CITV carries significant prognostic value in SRS-treated patients with BM, this variable should be considered during survival prognostication, along with other pertinent clinical, pathological, and molecular characteristics.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/cirurgia , Humanos , Prognóstico , Estudos Retrospectivos , Carga Tumoral
12.
Acta Neurochir Suppl ; 128: 101-106, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191065

RESUMO

OBJECTIVE: The present proof-of-principle study investigated radiobiological effects of redistributing central target dose hot spots across different treatment fractions during hypofractionated stereotactic radiosurgery (HSRS) of large intracranial tumors. METHODS: Redistribution of central target dose hot spots during HSRS was simulated, and its effects were evaluated in eight cases of brain metastases. To assess dose variations in the target across N number of treatment fractions, a generalized biologically effective dose (gBED) was formulated. The gBED enhancement ratio was defined as the ratio of gBED in the tested treatment plan (with central target dose hot spot redistributions across fractions) to gBED in the conventional treatment plan (without central target dose hot spot redistributions). RESULTS: At a median α value of 0.3/Gy, the tested treatment plans resulted in average gBED increases of 15.6 ± 3.5% and 8.3 ± 1.8% for α/ß ratios of 2 and 10 Gy, respectively. In comparison with conventional treatment plans, the differences in the Paddick conformity index and gradient index did not exceed 2%. CONCLUSION: Redistributing central target dose hot spots across different treatment fractions during HSRS may be considered promising for enhancing gBED in the target. It may be beneficial for management of large intracranial neoplasms; thus, it warrants further clinical testing.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Humanos
13.
Acta Neurochir Suppl ; 128: 85-100, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191064

RESUMO

Over the past 15-20 years, stereotactic radiosurgery (SRS) has become the dominant method for treating patients with brain metastases (BM). The role of surgery for management of large tumors also remains important. Combining these two treatment modalities may well achieve the best local control, safety, and symptomatic relief in cases of neoplasms for which resection is desirable. After 10 years of retrospective studies that suggested patients might do better if surgery were followed by early adjuvant SRS, a prospective, randomized, controlled trial was conducted to compare such treatment with postoperative observation after tumor removal, and it showed significantly better local control in the former cohort, especially in smaller lesions, but no difference in overall survival. On the other hand, in the past 5 years, some groups have argued that neoadjuvant SRS before resection of BM might be superior to adjuvant SRS, while no clinical trial has yet been concluded that compares these two treatment strategies. For now, adjuvant and neoadjuvant SRS show evidence of utility in achieving better local control after surgical removal of BM in comparison with surgery alone, but no specific guidelines exist favoring one method over the other, and both should be considered beneficial in clinical care.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/cirurgia , Humanos , Terapia Neoadjuvante , Recidiva Local de Neoplasia/prevenção & controle , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
14.
Acta Neurochir Suppl ; 128: 107-112, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191066

RESUMO

OBJECTIVE: The present biological modeling study evaluated possible application of adaptive hypofractionated stereotactic radiosurgery (HSRS), which involves escalation of the prescription dose according to the gradual decrease in the tumor volume between treatment sessions separated by 2- to 3-week intervals, in the management of large brain metastases. METHODS: To investigate the effects of dose escalation during three-stage adaptive HSRS, a generalized biologically effective dose (gBED) model was applied. Accounting for both a nonuniform dose distribution inside the target and tumor hypoxia was implemented, and normal brain radiation dose distributions were assessed. RESULTS: In comparison with conventional three-stage HSRS (with an identical prescription dose of 10 Gy at each treatment session), adaptive HSRS resulted in a 30-40% increase in gBED. This effect was especially prominent in late-responding targets (with α/ß ratios from 3 to 10 Gy) and in neoplasms containing a high percentage of hypoxic cells. Despite dose escalation in the target, irradiation of the adjacent normal brain tissue was kept within safe limits at a level similar to that applied in conventional three-stage HSRS. CONCLUSION: Adaptive HSRS theoretically results in significant enhancement of gBED in the target and may possibly overcome resistance to irradiation, which is caused by tumor hypoxia. These advantages may translate into higher treatment efficacy in cases of large brain metastases.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Humanos , Resultado do Tratamento , Carga Tumoral , Hipóxia Tumoral
15.
Acta Neurochir Suppl ; 128: 113-119, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191067

RESUMO

OBJECTIVE: This study evaluated the usefulness of arterial spin labeling (ASL) for assessment of tumor blood flow (TBF) and cerebral blood flow (CBF) before Gamma Knife surgery (GKS) for intracranial metastases, in order to analyze the variability of perfusion characteristics at baseline and to reveal how these data may impact differentiation of radiation-induced effects from tumor progression during follow-up. METHODS: Radiological data from 87 patients with intracranial metastases of solid cancers, who underwent TBF/CBF analysis by means of ASL at the Hawaii Advanced Imaging Institute between 2015 and 2018 both before and after GKS, were reviewed retrospectively. Only cases with a largest tumor diameter of ≥10 mm were included in the study cohort (N = 53). RESULTS: In comparison with CBF in the healthy contralateral cerebral cortex, TBF before GKS was greater in 32 cases (60%), lesser in 7 cases (13%), and equivalent in 14 cases (27%). There was significant variability in TBF both within and between histologically different groups of tumors. CONCLUSION: Since, at baseline, approximately 40% of intracranial metastases have TBF that is lesser or equivalent to CBF, increased blood flow in the contrast-enhancing lesion after GKS may have insufficient sensitivity for identification of tumor progression. Availability of baseline TBF data may significantly facilitate differential diagnosis in such cases.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Humanos , Imageamento por Ressonância Magnética , Necrose , Estudos Retrospectivos , Marcadores de Spin
16.
Acta Neurochir Suppl ; 128: 145-150, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191071

RESUMO

OBJECTIVE: The present study aimed to examine the technical feasibility and effectiveness of adapting the radiation dose distributions with three-dimensional (3D) linear couch translations in contrast to full six-dimensional couch maneuvers to correct for rotational shifts during frameless radiosurgical treatment with the Gamma Knife Icon™ (Elekta AB; Stockholm, Sweden). METHODS: The original magnetic resonance images used for radiosurgery treatment planning (15 targets) were digitally processed to simulate rotational shifts of ±1, ±2, ±3, ±5, and ±10 degrees in the transverse plane and imported back into Leksell GammaPlan® (Elekta AB), creating "uncorrected" treatment plans. In addition, geometrically optimized 3D translation shifts were consequently applied to each isocenter in all "uncorrected" treatment plans to account for systematically introduced rotational shifts and to produce "corrected" treatment plans. The differences in the dose distribution between the original treatment plans and the "uncorrected" and "corrected" treatment plans were calculated and compared at each rotational shift position. RESULTS: The "uncorrected" treatment plans resulted in a significant deterioration in target coverage (by 8-72%) and selectivity (by 2-42%), with some targets being missed completely with rotations of ±3 or more degrees. In contrast, in all "corrected" treatment plans, the average decreases in target coverage and selectivity were only 1% (maximum values 4-5%). CONCLUSION: Applications of 3D linear couch translations successfully overcome gross uncertainties in dose distributions caused by up to ±10 degrees of rotational shifts in a target. As a result, rapid dose adaptation with 3D couch translations is unique and effective for frameless radiosurgery with the Gamma Knife Icon™.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Encéfalo , Neoplasias Encefálicas/cirurgia , Tomografia Computadorizada de Feixe Cônico , Estudos de Viabilidade , Humanos
17.
J Clin Neurosci ; 89: 177-198, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34119265

RESUMO

Glioma is the most common primary intraparenchymal tumor of the brain and the 5-year survival rate of high-grade glioma is poor. Magnetic resonance imaging (MRI) is essential for detecting, characterizing and monitoring brain tumors but definitive diagnosis still relies on surgical pathology. Machine learning has been applied to the analysis of MRI data in glioma research and has the potential to change clinical practice and improve patient outcomes. This systematic review synthesizes and analyzes the current state of machine learning applications to glioma MRI data and explores the use of machine learning for systematic review automation. Various datapoints were extracted from the 153 studies that met inclusion criteria and analyzed. Natural language processing (NLP) analysis involved keyword extraction, topic modeling and document classification. Machine learning has been applied to tumor grading and diagnosis, tumor segmentation, non-invasive genomic biomarker identification, detection of progression and patient survival prediction. Model performance was generally strong (AUC = 0.87 ± 0.09; sensitivity = 0.87 ± 0.10; specificity = 0.0.86 ± 0.10; precision = 0.88 ± 0.11). Convolutional neural network, support vector machine and random forest algorithms were top performers. Deep learning document classifiers yielded acceptable performance (mean 5-fold cross-validation AUC = 0.71). Machine learning tools and data resources were synthesized and summarized to facilitate future research. Machine learning has been widely applied to the processing of MRI data in glioma research and has demonstrated substantial utility. NLP and transfer learning resources enabled the successful development of a replicable method for automating the systematic review article screening process, which has potential for shortening the time from discovery to clinical application in medicine.


Assuntos
Inteligência Artificial/tendências , Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Aprendizado de Máquina/tendências , Redes Neurais de Computação , Neuroimagem/tendências , Algoritmos , Neoplasias Encefálicas/cirurgia , Glioma/cirurgia , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/tendências , Neuroimagem/métodos , Procedimentos Neurocirúrgicos/métodos , Procedimentos Neurocirúrgicos/tendências , Máquina de Vetores de Suporte
18.
In Vivo ; 35(4): 2445-2450, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34182529

RESUMO

BACKGROUND/AIM: We examined the difference between whole-brain radiation therapy (WBRT) for intracranial metastases (IM) from lung cancer as an initial and as a late treatment affecting overall survival (OS). PATIENTS AND METHODS: Thirty-three patients who presented with IM at initial examination who received WBRT as the initial treatment (initial WBRT group) and 47 patients without IM or with asymptomatic IM at initial examination who received WBRT after systemic therapy, between January 2014 and December 2020, were retrospectively analyzed. Patients' OS after WBRT were compared. RESULTS: Median OS was significantly longer in patients treated with systemic anticancer therapy after WBRT than in patients who were not (176 vs. 47 days, respectively; p<0.001), and systemic anticancer therapy after WBRT was a significant prognostic factor (p<0.001). CONCLUSION: Treatment with systemic anticancer therapy after WBRT may prolong the survival of patients who present with IM at initial examination.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Encéfalo , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Irradiação Craniana , Humanos , Estudos Retrospectivos
19.
Int J Hyperthermia ; 38(1): 907-915, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34148489

RESUMO

BACKGROUND: High-intensity focused ultrasound (HIFU) serves as a noninvasive stereotactic system for the ablation of brain metastases; however, treatments are limited to simple geometries and energy delivery is limited by the high acoustic attenuation of the calvarium. Minimally-invasive magnetic resonance-guided robotically-assisted (MRgRA) needle-based therapeutic ultrasound (NBTU) using multislice volumetric 2-D magnetic resonance thermal imaging (MRTI) overcomes these limitations and has potential to produce less collateral tissue damage than current methods. OBJECTIVE: To correlate multislice volumetric 2-D MRTI volumes with histologically confirmed regions of tissue damage in MRgRA NBTU. METHODS: Seven swine underwent a total of 8 frontal MRgRA NBTU lesions. MRTI ablation volumes were compared to histologic tissue damage on brain sections stained with 2,3,5-triphenyltetrazolium chloride (TTC). Bland-Altman analyses and correlation trends were used to compare MRTI and TTC ablation volumes. RESULTS: Data from the initial and third swine's ablations were excluded due to sub-optimal tissue staining. For the remaining ablations (n = 6), the limits of agreement between the MRTI and histologic volumes ranged from -0.149 cm3 to 0.252 cm3 with a mean difference of 0.052 ± 0.042 cm3 (11.1%). There was a high correlation between the MRTI and histology volumes (r2 = 0.831) with a strong linear relationship (r = 0.868). CONCLUSION: We used a volumetric MRTI technique to accurately track thermal changes during MRgRA NBTU in preparation for human trials. Improved volumetric coverage with MRTI enhanced our delivery of therapy and has far-reaching implications for focused ultrasound in the broader clinical setting.


Assuntos
Neoplasias Encefálicas , Ablação por Ultrassom Focalizado de Alta Intensidade , Terapia por Ultrassom , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Suínos
20.
J Appl Clin Med Phys ; 22(7): 266-275, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34151498

RESUMO

PURPOSE: We calculated the dosimetric indices and estimated the tumor control probability (TCP) considering six degree-of-freedom (6DoF) patient setup errors in stereotactic radiosurgery (SRS) using a single-isocenter technique. METHODS: We used simulated spherical gross tumor volumes (GTVs) with diameters of 1.0 cm (GTV 1), 2.0 cm (GTV 2), and 3.0 cm (GTV 3), and the distance (d) between the target center and isocenter was set to 0, 5, and 10 cm. We created the dose distribution by convolving the blur component to uniform dose distribution. The prescription dose was 20 Gy and the dose distribution was adjusted so that D95 (%) of each GTV was covered by 100% of the prescribed dose. The GTV was simultaneously rotated within 0°-1.0° (δR) around the x-, y-, and z-axes and then translated within 0-1.0 mm (δT) in the x-, y-, and z-axis directions. D95, conformity index (CI), and conformation number (CN) were evaluated by varying the distance from the isocenter. The TCP was estimated by translating the calculated dose distribution into a biological response. In addition, we derived the x-y-z coordinates with the smallest TCP reduction rate that minimize the sum of squares of the residuals as the optimal isocenter coordinates using the relationship between 6DoF setup error, distance from isocenter, and GTV size. RESULTS: D95, CI, and CN were decreased with increasing isocenter distance, decreasing GTV size, and increasing setup error. TCP of GTVs without 6DoF setup error was estimated to be 77.0%. TCP were 25.8% (GTV 1), 35.0% (GTV 2), and 53.0% (GTV 3) with (d, δT, δR) = (10 cm, 1.0 mm, 1.0°). The TCP was 52.3% (GTV 1), 54.9% (GTV 2), and 66.1% (GTV 3) with (d, δT, δR) = (10 cm, 1.0 mm, 1.0°) at the optimal isocenter position. CONCLUSION: The TCP in SRS for multiple brain metastases with a single-isocenter technique may decrease with increasing isocenter distance and decreasing GTV size when the 6DoF setup errors are exceeded (1.0 mm, 1.0°). Additionally, it might be possible to better maintain TCP for GTVs with 6DoF setup errors by using the optimal isocenter position.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Humanos , Radiobiologia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...