1,720,992 research outputs found
Technical advances in radiation therapy for brain tumors
Full text linkRadiation therapy plays a critical role in the management of brain tumors. Recent advances in radiation techniques include the use of intensity-modulated radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and stereotactic radiosurgery (SRS). All of these techniques allow the delivery of higher radiation doses to the target volume, at the same time reducing the risk of toxicity to normal tissues as compared with conventional 3D conformal radiotherapy (3D-CRT). Proton therapy may represent a treatment alternative to photon irradiation, due to the more favorable dose distribution to the target volume. This review summarizes current developments in radiation therapy and their clinical impact on the management of patients with brain tumors
Stereotactic radiotherapy and radiosurgery for non-functioning and secreting pituitary adenomas
No full textLong term follow up of radionecrotic brain metastases assessed by serial F-DOPA PET/CT scans
No full textStereotactic Irradiation of GH-Secreting Pituitary Adenomas
Full text linkRadiotherapy (RT) is often employed in patients with acromegaly refractory to medical and/or surgical interventions in order to prevent tumour regrowth and normalize elevated GH and IGF-I levels. It achieves tumour control and hormone normalization up to 90% and 70% of patients at 10–15 years. Despite the excellent tumour control, conventional RT is associated with a potential risk of developing late toxicity, especially hypopituitarism, and its role in the management of patients with GH-secreting pituitary adenomas remains a matter of debate. Stereotactic techniques have been developed with the aim to deliver more localized irradiation and minimize the long-term consequences of treatment, while improving its efficacy. Stereotactic irradiation can be given in a single dose as stereotactic radiosurgery (SRS) or in multiple doses as fractionated stereotactic radiotherapy (FSRT). We have reviewed the recent published literature on stereotactic techniques for GH-secreting pituitary tumors with the aim to define the efficacy and potential adverse effects of each of these techniques
Selection of Shigella flexneri candidate virulence genes specifically induced in bacteria resident in host cell cytoplasm
No full text18F-DOPA uptake does not correlate with IDH mutation status and 1p/19q co-deletion in glioma
No full textObjective: The role of amino acid positron emission tomography (PET) in glioma grading and outcome prognostication has not yet been well established. This is particularly true in the context of the new WHO 2016 classification, which introduced a definition of glioma subtypes primarily based on molecular fingerprints. The aim of the present study was to correlate 3,4‐dihydroxy‐6‐[18F]‐fluoro-l‐phenylalanine (F-DOPA) uptake parameters with IDH mutation, 1p/19q status, and survival outcomes in patients with glioma. Methods: The study population consisted of 33 patients (17 M/16 F, mean age: 46 ± 13 years) who underwent F-DOPA PET/CT for the evaluation of tumor extent before the start of chemo or radiotherapy. The presence of IDH mutation and 1p/19q status was assessed in all the cases. Tumor volume and semiquantitative uptake parameters, namely SUVmax, tumor-to-normal brain ratio and tumor-to-normal striatum ratio, were calculated for each tumor. Imaging-derived parameters were compared between patients stratified according to molecular fingerprints, using parametric or non-parametric tests, where appropriate. The Kaplan–Meier method was used to assess differences of overall survival (OS) and progression-free survival (PFS) between groups. PET parameters were also tested as prognostic factors in univariate Cox survival regression models. Results: There were 12 IDH-wild-type and 21 IDH-mutant patients. Stratification according to 1p/19q co-deletion resulted in 20 non-co-deleted and 13 co-deleted patients. Median follow-up time from PET/CT exam was 30.5 months (range 3.5–74 months). Semiquantitative uptake parameters did correlate neither with IDH mutation nor with 1p/19q status. Uptake was similar in low-grade and high-grade tumors, respectively. In addition, F-DOPA uptake parameters, macroscopic tumor volume, or tumor grade did not stratify OS, while a correlation between SUVmax and PFS was shown in the subgroup of astrocytomas. On the other hand, IDH mutation status and presence of 1p/19q co-deletion had a significant impact on survival outcomes. The prognostic value of IDH mutation status was also confirmed in the subgroup of patients with astrocytic tumors. Conclusions: F-DOPA uptake parameters do not correlate with tumor molecular and histological characteristics. The predictive value of PET-derived parameters on outcomes of survival is limited
Value of F-DOPA PET in the long term follow up of radionecrotic brain metastases after radiosurgery: comparison with MRI
No full textF-DOPA PET identifies high tumor grade and anaplastic transformation in non-enhancing gliomas
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