[Utility of 11C-methionine PET/CT in neuro-oncology]. / Utilidad de 11C-metionina PET/CT en neurooncología.

Positron emission tomography (PET) with 11C-methionine (11C-methionine PET/CT) is a new technique used to evaluate primary central nervous system (CNS) tumors. We describe our experience regarding the first 4 patients with glial tumors and 11C-methionine PET/CT. This is a descriptive, observational and prospective study of 4 patients between 38-50 years of age, with different gliomas (WHO classification). MRI and 11C-methionine PET/CT were performed in all cases. Case 1, gliomatosis cerebri grade II post-radiotherapy. Case 2, oligodendroglioma grade II diagnosed and treated with radiotherapy in 1993. Case 3, glioblastoma grade IV post-radiotherapy + temozolomide. Case 4, anaplastic oligoastrocytoma grade III post-radiotherapy + temozolomide. The pattern of 11C-methionine uptake compared with MRI showed tumor progression in cases 1, 3 and 4, and in case 2 showed uptake although the final diagnosis was pseudoprogression. Unlike 18fluordeoxiglucose PET/TC, 11C-methionine uptake in normal brain tissue and pseudoprogression is low, and gliomas are displayed as metabolically active areas. The 11C-methionine PET/CT provided valuable information on the tumoral behavior and extension, although in one case presented did not differentiate tumor progression from pseudoprogression. 11C-methionine PET/CT could be a useful tool in the study and follow-up to patients with gliomas.

Utilidad de 11C-metionina PET/CT en neurooncología / Utility of 11C-methionine PET/CT in neuro-oncology

La tomografía por emisión de positrones con metionina carbono 11 (11C-metionina PET/TC) se utiliza en la evaluación de los tumores primarios del sistema nervioso central. Describimos nuestra experiencia sobre los primeros 4 pacientes con tumores de la serie glial estudiados con 11C-metionina PET/TC. Este es un estudio descriptivo, observacional y prospectivo. Se presentan 4 pacientes entre 38-50 años de edad con diagnóstico de gliomas (clasificación de la OMS). A todos se les realizó RM y 11C-metionina PET/TC para evaluar actividad tumoral y diferenciar progresión tumoral de pseudoprogresión. Caso 1, gliomatosis cerebri grado II posradioterapia. Caso 2, glioblastoma grado IV postratamiento RT + temozolomida. Caso 3, oligodendroglioma grado II posradioterapia en 1993. Caso 4, oligoastrocitoma anaplásico grado III postratamiento RT + temozolomida. El patrón de captación de la 11C-metionina comparativamente con la RM, demostró progresión tumoral en los casos 1, 3 y 4; en el caso 2 mostró captación aunque el diagnóstico final fue pseudoprogresión. A diferencia del PET con 18fluordeoxiglucosa, la captación de 11C-metionina en el tejido cerebral normal y en la pseudoprogresión es baja, y los gliomas se visualizan como áreas metabólicamente activas. En los casos presentados, el 11C-metionina PET/TC proveyó información valiosa sobre el comportamiento y extensión de la lesión, aunque en uno de los casos presentados no diferenció progresión tumoral de pseudoprogresión. El 11C-metionina PET/TC sería una herramienta útil en el estudio y seguimiento de los pacientes con gliomas.(AU)

Positron emission tomography (PET) with 11C-methionine (11C-methionine PET/CT) is a new technique used to evaluate primary central nervous system (CNS) tumors. We describe our experience regarding the first 4 patients with glial tumors and 11C-methionine PET/CT. This is a descriptive, observational and prospective study of 4 patients between 38-50 years of age, with different gliomas (WHO classification). MRI and 11C-methionine PET/CT were performed in all cases. Case 1, gliomatosis cerebri grade II post-radiotherapy. Case 2, oligodendroglioma grade II diagnosed and treated with radiotherapy in 1993. Case 3, glioblastoma grade IV post-radiotherapy + temozolomide. Case 4, anaplastic oligoastrocytoma grade III post-radiotherapy + temozolomide. The pattern of 11C-methionine uptake compared with MRI showed tumor progression in cases 1, 3 and 4, and in case 2 showed uptake although the final diagnosis was pseudoprogression. Unlike 18fluordeoxiglucose PET/TC, 11C-methionine uptake in normal brain tissue and pseudoprogression is low, and gliomas are displayed as metabolically active areas. The 11C-methionine PET/CT provided valuable information on the tumoral behavior and extension, although in one case presented did not differentiate tumor progression from pseudoprogression. 11C-methionine PET/CT could be a useful tool in the study and follow-up to patients with gliomas.(AU)

Utilidad de 11C-metionina PET/CT en neurooncología / Utility of 11C-methionine PET/CT in neuro-oncology

La tomografía por emisión de positrones con metionina carbono 11 (11C-metionina PET/TC) se utiliza en la evaluación de los tumores primarios del sistema nervioso central. Describimos nuestra experiencia sobre los primeros 4 pacientes con tumores de la serie glial estudiados con 11C-metionina PET/TC. Este es un estudio descriptivo, observacional y prospectivo. Se presentan 4 pacientes entre 38-50 años de edad con diagnóstico de gliomas (clasificación de la OMS). A todos se les realizó RM y 11C-metionina PET/TC para evaluar actividad tumoral y diferenciar progresión tumoral de pseudoprogresión. Caso 1, gliomatosis cerebri grado II posradioterapia. Caso 2, glioblastoma grado IV postratamiento RT + temozolomida. Caso 3, oligodendroglioma grado II posradioterapia en 1993. Caso 4, oligoastrocitoma anaplásico grado III postratamiento RT + temozolomida. El patrón de captación de la 11C-metionina comparativamente con la RM, demostró progresión tumoral en los casos 1, 3 y 4; en el caso 2 mostró captación aunque el diagnóstico final fue pseudoprogresión. A diferencia del PET con 18fluordeoxiglucosa, la captación de 11C-metionina en el tejido cerebral normal y en la pseudoprogresión es baja, y los gliomas se visualizan como áreas metabólicamente activas. En los casos presentados, el 11C-metionina PET/TC proveyó información valiosa sobre el comportamiento y extensión de la lesión, aunque en uno de los casos presentados no diferenció progresión tumoral de pseudoprogresión. El 11C-metionina PET/TC sería una herramienta útil en el estudio y seguimiento de los pacientes con gliomas.

Positron emission tomography (PET) with 11C-methionine (11C-methionine PET/CT) is a new technique used to evaluate primary central nervous system (CNS) tumors. We describe our experience regarding the first 4 patients with glial tumors and 11C-methionine PET/CT. This is a descriptive, observational and prospective study of 4 patients between 38-50 years of age, with different gliomas (WHO classification). MRI and 11C-methionine PET/CT were performed in all cases. Case 1, gliomatosis cerebri grade II post-radiotherapy. Case 2, oligodendroglioma grade II diagnosed and treated with radiotherapy in 1993. Case 3, glioblastoma grade IV post-radiotherapy + temozolomide. Case 4, anaplastic oligoastrocytoma grade III post-radiotherapy + temozolomide. The pattern of 11C-methionine uptake compared with MRI showed tumor progression in cases 1, 3 and 4, and in case 2 showed uptake although the final diagnosis was pseudoprogression. Unlike 18fluordeoxiglucose PET/TC, 11C-methionine uptake in normal brain tissue and pseudoprogression is low, and gliomas are displayed as metabolically active areas. The 11C-methionine PET/CT provided valuable information on the tumoral behavior and extension, although in one case presented did not differentiate tumor progression from pseudoprogression. 11C-methionine PET/CT could be a useful tool in the study and follow-up to patients with gliomas.

[Crossed cerebellar diaschisis. Study of a patient by magnetic resonance imaging and positron emission tomography]. / Diasquisis cerebelosa cruzada. Estudio de una paciente con resonancia magnetica y tomografia por emision de positrones.

INTRODUCTION: Crossed cerebellar diaschisis is a functional deficit in an area that is remote from that of a supratentorial brain lesion, although the two are anatomically and functionally connected. Deactivation of the contralateral cerebellar hemisphere occurs and is believed to be caused by a transneuronal metabolic depression of the cortico-ponto-cerebellar pathway. A reduction in the blood flow in the brain takes place and this gives rise to a diminished oxygenation of the cerebellar hemisphere. This finding can be evaluated by different functional imaging methods. CASE REPORT: A 32-year-old female, without any relevant events in her personal history, presented an extensive supra-tentorial ischaemic lesion on the right-hand side. An MR angiography scan was performed, in which the homolateral middle cerebral artery and internal carotid artery were not identified. With no specific causation and suspecting a probable case of vasculitis (two days after the first ischaemic episode, the patient suffered another one in the left-hand occipital area, although this time it was smaller and clinically asymptomatic), a positron emission tomography/computerised tomography (PET/CT) scan was performed. The results revealed hypoenhancement of the radiotracer in the contralateral cerebellar hemisphere, which was interpreted as hypometabolism. CONCLUSIONS: Determined by a possible prognostic value in the presence of crossed cerebellar diaschisis in supratentorial vascular episodes, with respect to the final clinical outcome of the patients, it is interesting to take this possibility into account when evaluating patients with an acute cerebrovascular accident, either by means of PET/CT, MR imaging (perfusion) or CT (perfusion).

Diasquisis cerebelosa cruzada. Estudio de una paciente con resonancia magnética y tomografía por emisión de positrones / Crossed cerebellar diaschisis. Study of a patient by magnetic resonance imaging and positron emission tomography

La diasquisis cerebelosa cruzada es una deficiencia funcional en un área remota a la de una lesión cerebral supratentorial, pero anatómica y funcionalmente conectadas. Se produce una desactivación del hemisferio cerebeloso contralateral, y se considera que la causa una depresión metabólica transneuronal de la vía corticopontocerebelosa. Existe una reducción del flujo sanguíneo cerebral y, por consiguiente, de la oxigenación del hemisferio cerebeloso. Este hallazgo puede evaluarse a través de diferentes métodos de imágenes funcionales. Caso clínico. Mujer de 32 años, sin antecedentes personales relevantes, que presentó una extensa lesión isquémica supratentorial derecha. Se estudió mediante angiorresonancia, en la que no se identificaron la arteria cerebral media y la arteria carótida interna homolaterales. Sin etiología específica, pensando en una probable vasculitis (dos días después del inicial, la paciente sufrió otro episodio isquémico en el área occipital izquierda, de menor tamaño y clínicamente asintomático), se realizó una tomografía por emisión de positrones/tomografía computarizada (PET/TC) y se observó hipocaptación del radiotrazador del hemisferio cerebeloso contralateral, interpretado como hipometabolismo. Conclusión. En función de un posible valor pronóstico en la presencia de diasquisis cerebelosa cruzada en episodios vasculares supratentoriales, con respecto al resultado clínico final de los pacientes, es interesante tener presente esta posibilidad en la evaluación de pacientes con accidente cerebrovascular agudo, ya sea mediante PET/TC, resonancia magnética (perfusión) o TC (perfusión) (AU)

Introduction. Crossed cerebellar diaschisis is a functional deficit in an area that is remote from that of a supratentorial brain lesion, although the two are anatomically and functionally connected. Deactivation of the contralateral cerebellar hemisphere occurs and is believed to be caused by a transneuronal metabolic depression of the cortico-ponto-cerebellar pathway. A reduction in the blood flow in the brain takes place and this gives rise to a diminished oxygenation of the cerebellar hemisphere. This finding can be evaluated by different functional imaging methods. Case report. A 32-year-old female, without any relevant events in her personal history, presented an extensive supratentorial ischaemic lesion on the right-hand side. An MR angiography scan was performed, in which the homolateral middle cerebral artery and internal carotid artery were not identified. With no specific causation and suspecting a probable case of vasculitis (two days after the first ischaemic episode, the patient suffered another one in the left-hand occipital area, although this time it was smaller and clinically asymptomatic), a positron emission tomography/computerised tomography (PET/CT) scan was performed. The results revealed hypoenhancement of the radiotracer in the contralateral cerebellar hemisphere, which was interpreted as hypometabolism. Conclusions. Determined by a possible prognostic value in the presence of crossed cerebellar diaschisis in supratentorial vascular episodes, with respect to the final clinical outcome of the patients, it is interesting to take this possibility into account when evaluating patients with an acute cerebrovascular accident, either by means of PET/CT, MR imaging (perfusion) or CT (perfusion) (AU)

Utilidad de 11C-metionina PET/CT en neurooncología. / [Utility of 11C-methionine PET/CT in neuro-oncology].

Positron emission tomography (PET) with 11C-methionine (11C-methionine PET/CT) is a new technique used to evaluate primary central nervous system (CNS) tumors. We describe our experience regarding the first 4 patients with glial tumors and 11C-methionine PET/CT. This is a descriptive, observational and prospective study of 4 patients between 38-50 years of age, with different gliomas (WHO classification). MRI and 11C-methionine PET/CT were performed in all cases. Case 1, gliomatosis cerebri grade II post-radiotherapy. Case 2, oligodendroglioma grade II diagnosed and treated with radiotherapy in 1993. Case 3, glioblastoma grade IV post-radiotherapy + temozolomide. Case 4, anaplastic oligoastrocytoma grade III post-radiotherapy + temozolomide. The pattern of 11C-methionine uptake compared with MRI showed tumor progression in cases 1, 3 and 4, and in case 2 showed uptake although the final diagnosis was pseudoprogression. Unlike 18fluordeoxiglucose PET/TC, 11C-methionine uptake in normal brain tissue and pseudoprogression is low, and gliomas are displayed as metabolically active areas. The 11C-methionine PET/CT provided valuable information on the tumoral behavior and extension, although in one case presented did not differentiate tumor progression from pseudoprogression. 11C-methionine PET/CT could be a useful tool in the study and follow-up to patients with gliomas.