Perfusion-weighted imaging is a feasible method of reducing the sampling error in the histopathological diagnosis of a presumed LGG, particularly by improving the selection of targets for stereotactic biopsy.

Medulloblastoma has variable appearances on MRI in both children and adults. Adults are more likely to have heterogeneous cerebellar hemisphere tumours, and this is thought to be related to the greater prevalence of desmoplastic tumours in adulthood. Few studies have addressed the MRI features of adult medulloblastoma and the specific characteristics of desmoplastic and classic tumours have not been analysed. Our aim was to analyse the imaging characteristics of desmoplastic (DM) and classic (CM) medulloblastomas in adult. We retrospectively studied preoperative MRI of six men and three women, median age 33 years, range 23-53 years, with pathologically proved medulloblastomas. There were six (67%) with DM. The tumour was in the cerebellar hemisphere in eight patients (89%), including the three with CM, one of which was bilateral. All tumours were heterogeneous, giving predominantly low or isointense signal on T1- and isointense signal on T2-weighted images. Cystic or necrotic areas in all patients were particularly visible on T2-weighted images. Contrast enhancement was absent in one DM and varied from slight to intense in eight (three CM), homogeneous in one DM and patchy in seven. All tumours extended to the surface of the cerebellum and two had well-defined margins. MRI does not allow a clear distinction between DM and CM in adults.

Background: Cancer patients in general and glioblastoma patients, in particular, have an increased risk of developing complications from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and reaching a balance between the risk of exposure to infection and the clinical benefit of their treatment is ideal. The aggressive behavior of this group of tumors justifies the need for a multidisciplinary team to assist in clinical decisions during the current pandemic. Brazil is now ranked #2 in the number of cases and deaths from COVID-19 pandemic, and existing disparities in the treatment of neuro-oncology patients in Brazil will challenge the clinical and surgical decisions of this population, possibly affecting global survival. Objective: To search the literature about the management of glioblastomas during COVID-19 pandemic to guide surgical and clinical decisions in this population of patients in Brazil. Methods: We performed a systematic search on the PubMed electronic database targeting consensus statements concerning glioblastoma approaches during COVID-19 pandemic up to July 18, 2020. Results: When approaching glioblastoma during the COVID-19 pandemic, important parameters that help in the decision-making process are age, performance status, tumor molecular profile, and patient consent. Younger patients should follow the standard protocol after maximal safe resection, mainly those with MGMT methylated tumors. Aged and underperforming patients should be carefully evaluated, and probably a monotherapy scheme is to be considered. Centers are advised to engage in telemedicine and to elaborate means to reduce local infection. Conclusion: Approaching glioblastoma during the COVID-19 pandemic will be challenging worldwide, but particularly in Brazil, where a significant inequality of healthcare exists.

As metástases cerebrais ocorrem comumente em pacientes com câncer. A freqüência dessa complicação está aumentando em decorrência do tratamento mais agressivo do câncer, bem como do uso de métodos de neuroimagem que permitem um diagnóstico mais preciso. Com o melhor controle dos tumores primários, permitido pelos tratamentos atuais, a importância do tratamento dessas metástases é óbvia. Os principais objetivos do tratamento são melhorar os déficits neurológicos e aumentar a expectativa e a qualidade de vida. Os autores revisam as manifestações clínicas, o diagnóstico e as principais opções para o tratamento das metástases cerebrais.

Objective: To evaluate the effect of waiting time (WT) to radiotherapy (RT) on overall survival (OS) of glioblastoma (GBM) patients as a reliable prognostic variable in Brazil, a scenario of medical disparities. Method: Retrospective study of 115 GBM patients from two different health-care institutions (one public and one private) in Brazil who underwent post-operative RT. Results: Median WT to RT was 6 weeks (range, 1.3-17.6). The median OS for WT # 6 weeks was 13.5 months (95%CI , 9.1-17.9) and for WT . 6 weeks was 14.2 months (95%CI, 11.2-17.2) (HR 1.165, 95%CI 0.770-1.762; p = 0.470). In the multivariate analysis, the variables associated with survival were KPS (p , 0.001), extent of resection (p = 0.009) and the adjuvant treatment (p = 0.001). The KPS interacted with WT to RT (HR 0.128, 95%CI 0.034-0.476; p = 0.002), showing that the benefit of KPS on OS depends on the WT to RT. Conclusion: No prognostic impact of WT to RT could be detected on the OS. Although there are no data to ensure that delays to RT are tolerable, we may reassure patients that the time-length to initiate treatment does not seem to influence the control of the disease, particularly in face of other prognostic factors.Keywords: glioblastoma, radiotherapy, waiting time, delay, prognosis, survival. RESUMOObjetivo: Avaliar o efeito do tempo de espera (TE) até radioterapia na sobrevida global de pacientes com glioblastoma como um fator prognóstico confiável. Método: Estudo retrospectivo de 115 pacientes com glioblastoma, que foram submetidos à radioterapia pós-operatória, em dois serviços diferentes no Brasil (um público e outro privado). Resultados: Mediana de TE para radioterapia foi de 6 semanas (variação, 1,3-17,6). A mediana de sobrevida para TE # 6 semanas foi de 13,5 meses (IC95%, 9,1-17,9) e para TE . 6 semanas foi de 14,2 meses (IC95%, 11,2-17,2) (HR 1,165, 0,762; p = 0,470). Na análise multivariada, as variáveis associadas à sobrevida foram perfomance status (p , 0,001), extensão da ressecção (p = 0,009) e tratamento adjuvante (p = 0,001). Conclusão: Não se observou impacto prognóstico para TE até a radioterapia na sobrevida. Diante de outros fatores prognósticos, é possível assegurar de que o espaço de tempo até a radioterapia não parece influenciar o controle da doença.Palavras-chave: glioblastoma, radioterapia, tempo de espera, atraso, prognóstico, sobrevida.