Intracranial plasma cell granuloma evaluated by positron emission tomography.

A 50-year-old farmer with plasma cell granuloma had PET scans showing marked accumulation of C-11 Met. The PET had superiority in imaging the existence and extent of the lesion and monitored therapeutic response as compared with CT and MR imaging. PET yields information on hemocirculatory and metabolic aspects of this rare disease.     

Radiation-induced bilateral cystic frontal lobe necroses demonstrating a fluid-blood level--case report.

A 41-year-old male developed radiation-induced bilateral cystic frontal lobe necroses after irradiation for an olfactory neuroblastoma. Computed tomography (CT) and magnetic resonance (MR) imaging revealed the lesions, one containing a fluid-blood level on CT scans and niveau formation on MR images. It was proved to be a coagulated hematoma within the cyst at surgery. Such a fluid-blood level in a radiation-induced cyst has never been reported, although hemorrhage frequently accompanies delayed radiation necrosis. Positron emission tomography with multiple tracers may be useful in differentiating cerebral radiation necrosis from tumor recurrence, because of absence of abnormal tracer accumulation.     

Measurement of O-6-methylguanine-DNA methyltransferase activity using oligonucleotides and restriction enzyme in human brain tumors

We determined the levels of MGMT activity in 46 human brain tumors, using oligonucleotides containing O-6-methylguanine at a PvuII recognition site, and correlated MGMT activity with chemotherapeutic effectiveness in 14 patients with high-grade gliomas who received ACNU chemotherapy. The results characterize MGMT activities among different types and within individual types of human brain tumors. A certain fraction of gliomas exhibited a low value of MGMT activity. Tumors showing a low MGMT activity responded well to ACNU and resulted in prolongation in the time to tumor progression. Thus, the low MGMT activity of gliomas may provide a theoretical basis for application of CENU chemotherapy.     

Modulation of BUdR labeling index in rat brain tumors following intracarotid ACNU administration

Summary Chloroethy1nitrosourea (CENU) chemotherapy has yielded limited benefit on survival of malignant brain tumors. Intracarotid administration of CENU is expected to have the advantage of increasing drug concentration reaching tumors. To understand basic knowledge of intracarotid chemotherapy, we monitor changes of proliferating rate after intracarotid injection of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2chloroethyl)-3-nitrosourea hydrochloride (ACNU), using a bromodeoxyuridine (BUdR) labeling index (LI) in transplanted brain tumors of three cell strains.C6-2 tumor cells were in vitro sensitive to ACNU, and C6-2/ACNU and C6-1 cells were resistant. The drug sensitivity to ACNU was as follows: 11.9 tM in the C6-2 cells, 46.0 M in the C6-2/ACNU cells, and 49.7 M in the C6-1 cells at SD10, which gives 10% survival of clonogenic cells. The intracarotid ACNU at a dose of 30 mg/kg abruptly decreased the LI to 11% (mean) from 36% in C6-2 transplanted tumors. The LI remained low between 12 and 48 hours after, and then increased to the pretreatment level by 96 hours. In contrast, the LI of C6-1 tumors transiently fell to 15% from 42% at 12 hours after the injection, and subsequently increased to 36% at 24 hours and 37% at 48 hours.These results indicate that intracarotid ACNU administration shortly suppresses proliferating activity of tumors and that combined and alternating chemotherapy are mandatory for enhancing effectiveness of brain tumor chemotherapy.     

Subependymoma of the septum pellucidum: Characterization by PET

We report the evaluation of a subependymoma of the septum pellucidum by positron emission tomography (PET) with analysis of ₁₈F-fluorodeoxyglucose (FDG)kinetics. The tumor showed exceedingly low rates of glucose metabolism (rCMRG1) and kinetic constants (K1, K2, and K3). This hypometabolism indicates low cellular density and slow growth.     

Multiple intracranial mycotic aneurysm. Report of a case (author's transl)]

A case of intracranial mycotic aneurysm was reported, in whom repeated cerebral angiographies demonstrated the seccessive appearance of multiple aneurysms in a short term after the septic cerebral infection, and the importance of repeated angiography in the treatment of the intracranial mycotic aneurysm was stressed. A 44-year old male who had heart failure developed suddenly a left hemiparesis with irritable meningial signs on Nov. 3, 1973. The right carotid angiography carried out on Nov. 16 in an admitted hospital showed partial obliteration of cortical branches of the middle cerebral shift of the anterior cerebral artery due to the cerebral infarction. No aneurysm was demonstrated in the angiogram. The second angiography of the right carotid and vertebral artery was done on the admission of Dec. 18. The previously shown contralateral shift of the anterior cerebral artery was remarkably decreased, and an aneurysm of 3 mm in diameter was recognized at the cortical branch of the right middle cerebral artery on the parietal region. Any aneurysm was not revealed by the vertebral angiography. The third angiography of bilateral carotid and vertebral artery was performed on Dec. 25. The previously revealed aneurysm increased in size. Multiple aneurysms was demonstrated at the anterior branches of the insular artery. The vertebral angiography demonstrated multiple aneurysms at the peripheral portion of the bilateral posterior cerebral arteries. The patient was improved neurologically after the administration of antibiotics, and was discharged on Dec. 27 on the convenience of his family and would be followed in conservative cares.     

Blood Flow and Metabolism of Oligodendrogliomas: A Positron Emission Tomography Study with Kinetic Analysis of 18F-fluorodeoxyglucose

To accurately characterize the pathophysiology and proliferating activity of oligodendrogliomas, we studied cerebral blood flow and metabolism using positron emission tomography (PET) in five patients with this tumor. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction fraction (rOEF), and cerebral metabolic rates of oxygen (rCMRO₂) and of glucose (rCMRGl) were quantitatively measured in tumor lesions and the contralateral gray matter. rCMRGl was analyzed based on both kinetic and autoradiographic methods. Tumor rCBF and rCBV were lower than in the contralateral gray matter in all preoperatively examined patients. Oxygen metabolism, determined by rCMRO₂ and rOEF, was consistently reduced in the tumor (rCMRO₂, P<0.05 vs. gray matter, determined by the Student's t-test). Tumor rCMRGl was significantly lower than the gray matter rCMRGl in both kinetic (P<0.01) and autoradiographic (P<0.05) analyses. Kinetic tumor rCMRGl varied between 1.22 and 4.13mg/100ml/min, but was lower than the gray matter value in all patients. Autoradiographic tumor rCMRGl, which ranged from 1.02 to 5.79mg/100ml/min, was also reduced in all tumors but one; the remaining tumor, which had a relatively high value of autoradiographic rCMRGl (comparable to gray matter rCMRGl), infiltrated the contralateral hemisphere through the corpus callosum, and was characterized by high cellular density. In one patient who suffered from tumor recurrence 8 years and 10 months after initial treatment, phosphorylation constant (K3) and kinetic rCMRGl of the recurring tumor were higher than those of the original tumor. No other tumors have regrown or recurred during the postoperative follow-up periods, which ranged from 22 to 130 months (median=101 months). Circulation and metabolism measured by PET provide in vivo biological characteristics, including proliferating activity, in oligodendrogliomas.     

Cerebellopontine angle xanthogranuloma: report of a surgical case

A Case of xanthogranuloma at the cerebellopontine angle is reported here in detail with a review of the literature. A 36-year-old male suffered from tinnitus and hearing disturbance for five months before admission. View of the internal auditory canal showed widening and destruction on the right side. Auditory brain stem response did not clarify any of wave. A slight high density area was revealed by CT with some degree of enhancement. A right paramedian suboccipital craniectomy revealed an encapsulated tumor at the right cerebellopontine angle extending into the internal auditory canal. The tumor was reddish-brown, creamy and 2 cm in diameter, which was totally extirpated. Twenty two days after the operation, the patient was discharged with a slight improvement of the right tinnitus. Seventeen surgical cases of intracranial xanthogranuloma were reviewed including the presented case. There were 10 males and seven females, and the age ranged from six to 57 years. Many of them were located in the choroid plexus or the dura mater. The presented case was the first reported one documenting a xanthogranuloma at the cerebellopontine angle. A solitary lesion was seen in 13 cases, and multiple lesions in four cases, among which Hand-Schüller-Christian disease was observed in two, and Weber-Christian disease in one. A high density area was revealed in eight out of nine cases, and some degree of enhancement was seen in nine. Surgical removal was performed totally in nine cases, subtotally in six, and partially in one. The outcome was excellent in eight cases, good in three, fair in one, poor in two, and dead in three.