Browsing by Author "Passos, Joao"
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- Cognitive function, cerebral microbleeds, radiotherapy, and bevacizumab in survivors of pediatric brain tumorsPublication . Passos, Joao; Nzwalo, Hipólito; Marques, Joana; Azevedo, Ana; Nunes, Sofia; Salgado, DuarteWe read with great interest a recent paper published by Roddy et al showing a high (48.8%) 5-year cumulative incidence of cerebral microbleeds (CMB) and its association with cognitive dysfunction in a group with pediatric brain tumors who received cranial radiation therapy (CRT).1 We believe that exposing the association of CMB (or the associated underlying microvascular pathology) with cognitive impairment in this population will help draw attention to the importance of the topic in this specific growing population.
- Dramatic improvement of a massive plexiform neurofibroma after administration of selumetinibPublication . Passos, Joao; Nzwalo, Hipólito; Azevedo, Miguel; Tavares, Mario; Nunes, Sofia
- Microbleeds and cavernomas after radiotherapy for paediatric primary brain tumoursPublication . Passos, Joao; Nzwalo, Hipólito; Valente, Mariana; Marques, Joana; Azevedo, Ana; Netto, Eduardo; Mota, Antonio; Borges, Alexandra; Nunes, Sofia; Salgado, DuarteBackground: With the expected growth and aging of the population of primary central nervous system tumours (PCNST) survivors, attention to the radiation-induced late brain injury is fundamental. Late focal hemosiderin deposition (FHD) lesions, namely microbleeds and cavernomas, are among the presumable late cerebrovascular complications associated with radiotherapy for PCNST. Objective: To explore association between PCNST radiotherapy and the occurrence FHD lesions and to address the correlation between the topographic location of these microvascular lesions with the focal radiotherapy location. Methods: Retrospective cohort study of 190 paediatric patients being followed for PCNST in a single referral ontological centre. The frequency of FHD lesions was compared between paediatric PCNST treated (n = 132) and not treated (n = 58) with brain radiation. Microbleed Anatomical Rating Scale (MARS) was used for systematic identification of these cerebrovascular lesions and to address the consistency between the topographic location of each lesion and the location of the focal radiotherapy area. Univariate analysis to address the role of variables such as tumour histology, location, gender and age of children at the beginning of radiotherapy, duration of follow-up and chemotherapy was performed. Results: FHD lesions (microbleeds and cavernomas) occurred exclusively and in a high percentage (41.6%) in PCNST survivors treated with brain radiation. Younger age at the diagnosis (p = 0.031), duration of follow-up (p = 0.010) and embryonal histology (p = 0.003) positively correlated with the occurrence FHD lesions. FHD lesions were topographically concordant with the brain focal irradiation area in 3/19 (15.8%) patients from the focal RT subgroup and in 22/111 (19.8%) patients from the WBRT plus focal RT subgroup. Conclusion: Our study, which is one of the largest to date on the topic, shows that FHD lesions are a common complication after radiotherapy for childhood PCNST. The young brain is probably more susceptible to radiation-induced late cerebrovascular injury. Diffuse small vessel disease and ceiling effect may account for the low topographic concordance we found. The clinical implications of FHD lesions in this specific population are yet to be clarified. (C) 2016 Elsevier B.V. All rights reserved.
- Mirror meningiomas: a late rare finding after radiotherapy for childhood for a craniopharyngiomaPublication . Passos, Joao; Nzwalo, Hipólito; Pedro, Catia; Ferreira, Diana; Borges, Alexandra
- Selumetinib for plexiform neurofibromas in neurofibromatosis type 1: a single-institution experiencePublication . Espirito Santo, Vera; Passos, Joao; Nzwalo, Hipólito; Carvalho, Ines; Santos, Filipa; Martins, Carmo; Salgado, Lucilia; Silva, Conceicao e; Vinhais, Sofia; Vilares, Miguel; Salgado, Duarte; Nunes, SofiaBackground Plexiform neurofibromas (PN) are the most frequent tumors associated with Neurofibromatosis type 1 (NF-1). PN can cause significant complications, including pain, functional impairment, and disfigurement. There is no efficient medical treatment and, surgical resection of large PN is frequently infeasible. Selumetinib (AZD6244/ARRY-142886) is a mitogen-activated protein kinase enzyme (MEK1/2) inhibitor and works by targeting the MAPK pathway. It is an investigational treatment option for inoperable symptomatic PN associated with NF-1. Herein, we describe a single institutional experience with selumetinib for inoperable PN in NF-1. Methods Case series study of demographics, clinical, baseline characteristics, treatment effect, and follow-up of consecutive genetically confirmed NF1 patients with inoperable PN associated with significant or potential significant morbidity treated with selumetinib (April 2018 to April 2019). Results Nineteen patients were treated with selumetinib. Predominant target locations were head and neck (31.6%, 6/19), chest (26.3%, 5/19) and pelvis (21%, 4/19) and the most important comorbidities were disfigurement (47.4%, 9/19) and pain (26.3%, 5/19). The mean follow-up time was 223 days (range 35-420 days). All but one had sustained clinical improvement, mainly in the first 60-90 days of treatment. In one patient, the treatment was suspended after 168 days (lack of clear benefit and left ventricular ejection fraction drop). There were no adverse effects leading to treatment suspension. Conclusions In the first observational study of selumetinib for NF-1 associated PN we showed that the drug was associated with clinical and radiological improvement. Our study also confirms the safety described in the clinical trials.