La pet con 11c-metionina como factor pronóstico y en la caracterización de gliomas
- Autores: Antoni Mestre-Fusco
- Directores de la Tesis: Joan Castell Conesa (dir. tes.), Francisco Alameda Quitllet (codir. tes.), Gerardo Conesa Bertrand (codir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2015
- Idioma: español
- Tribunal Calificador de la Tesis: Montserrat Estorch Cabrera (presid.), Josep Lloreta Trull (secret.), Joan Duch Renom (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
Background: Methionine PET is an imaging diagnostic tool useful in brain tumour diagnosis and follow up. PET utility to assess tumor aggressiveness for tumoral gradation as well as for the study of cell proliferation in gliomas has been described. However there is few evidence of PET both for prognostic factor evaluation, specially in the case of multivariate study, and for immunohistochemical or molecular characterization in gliomas.
The aims of this study include: 1. To evaluate the utility of methionine PET (Ratio T/N) to assess several prognostic factors associated with gliomas: gradation (to classify between low grade and high grade gliomas), tumoral proliferation index (Ki67%), MRI perfusion (rCBV), and to characterize prognostic markers as immunohistochemical markers (p53, p16, WT1, vascular CD34, CD44, B-catenin, EGFR) and molecular markers (IDH1 mutation, MGMT methylation and LOH 1p/19q) in gliomas. 2. Univariate and multivariate analysis of survival factors including PET (evaluated with Ratio T/N method): patient variables like age and KPS index, macroscopic characteristics of tumour, MRI contrast uptake, pathological findings like tumoral grade and Ki67 index, and use of surgical techniques like mapping and 5-ALA.
A retrospective study was performed including 38 patients diagnosed with glioma who were studied with methionine PET.
The results show a relationship between methionine PET and the prognostic factors previously described in gliomas as well as with survival. ROC curve analysis shows an optimal cut-off of Ratio T/N of 2.07 in the classification between low-grade and high-grade gliomas. Correlation between Ratio T/N of methionine PET and Ki67 index as well as MRI perfusion (rCBV) is observed. There is a relationship between a lower expression of immunosuppression factors (p53, p16 and WT1) and the metabolic activity of PET in low-grade gliomas. A relationship between Ratio T/N and mutation IDH1 status in gliomas is observed. In addition, a relationship between Ratio T/N and patient survival is observed in univariate and multivariate analysis: patients with lower metabolic PET activity in a glioma lesion have longer survival.
In conclusion methionine PET could be used as a complementary tool in the prognosis evaluation of gliomas and in their clinical management.
