1/6. Radiation-induced brain calcification: paradoxical high signal intensity in T1-weighted MR images.BACKGROUND: Irradiation to the central nervous system (CNS) in childhood is known to induce cerebral calcification after a latent period. Calcification has been generally found to show nil or a reduction in signal intensity in magnetic resonance (MR) images. However, we have studied three patients with radiation-induced brain calcification, who manifested increased signal intensity on T1-weighted MR images. METHOD: Three girls had each been diagnosed as having a suprasellar germ cell tumour and were treated with conventional fractionated radiotherapy in their childhood. In one case, chemotherapy was given prior to the CNS irradiation. FINDINGS: All three patients survived their disease, and a follow-up CT scan revealed calcification in the brain, which has shown an increased signal intensity in the T1-weighted images of MR. INTERPRETATION: Cerebral calcification may be presented as a high signal intensity in the T1-weighted MR images. This may be explained by a surface-relaxation effect by the calcium salt particle, precipitated in the brain due to radiation-induced mineralising microangiopathy.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
2/6. Complications of hyperbaric oxygen in the treatment of head and neck disease.Hyperbaric oxygen has been advocated in the treatment of many head and neck diseases. Reports of such treatments have described eustachian tube dysfunction as the only complication. A review of patients receiving hyperbaric oxygen for head and neck diseases at The Mount Sinai Medical Center revealed serious complications, which included seizure, stroke, and myocardial infarction. In addition, follow-up study of these patients demonstrated that 11 patients treated for radiation-induced necrosis had an undiagnosed recurrence of cancer.- - - - - - - - - - ranking = 0.5keywords = radiation-induced (Clic here for more details about this article) |
3/6. Occlusive arteriopathy and brain tumor.Four cases with the association of occlusive arteriopathy and brain tumor are presented. A clinical analysis of these cases and cases reported in the literature revealed that occlusive arteriopathy at the base of the brain was often associated with a slowly growing basal tumor in children. Possible causes of occlusive arteriopathy in these cases were compression of the circle of willis by a slowly growing basal tumor, secondary artial occlusive changes by radiation therapy for a basal tumor, or vasculopathy associated with neurocutaneous syndrome. Symptoms of sudden onset or episodic nature suggest the presence of occlusive arteriopathy rather than the mass effect of a tumor. cerebral angiography is mandatory whenever computerized tomography (CT), performed to rule out recurrence of a basal tumor, shows an ischemic lesion with low-density areas without any evidence of mass effect of the tumor. cerebral angiography is also necessary when a basal tumor is suspected in children, particularly in cases associated with neurocutaneous syndrome and a basal tumor. Care should be taken not to scarify the abnormal vascular network at the base of the brain at the time of operation, because it is considered to be functioning as collateral circulation. The potential hazards of radiotherapy to radiation-induced occlusive changes of the circle of willis must be considered in treating a benign basal brain tumor in children. Even in adults, repeated large doses of irradiation could cause occlusive arteriopathy.- - - - - - - - - - ranking = 0.5keywords = radiation-induced (Clic here for more details about this article) |
4/6. Intracranial large vessel vasculopathy and anaplastic meningioma 19 years after cranial irradiation for acute lymphoblastic leukaemia.A child was diagnosed in 1969 as having acute lymphoblastic leukaemia (ALL) and received chemotherapy. On bone marrow relapse in 1973, he was treated with cranial irradiation (20 Gy) in addition to chemotherapy. He continues in complete remission 19 years after his relapse. At age 25 years, he presented with headaches and left hemiparesis. Computerised tomograph demonstrated a large, enhancing right-sided intracranial tumour. Angiography was performed and showed the right internal carotid artery was occluded. Most of the right hemisphere was supplied from the external carotid via the middle meningeal artery. The left posterior cerebral artery and the left anterior cerebral artery were absent presumably as a result of radiation-induced arteritis. A resection of an anaplastic meningioma arising from the right sphenoidal ridge was achieved. There was a rapid improvement in function and he returned to work. Vasculopathy of the large intracranial arteries has been described after high dose radiation. It may occur as in this case after moderate dose radiation. There is a correlation with meningioma. There is a possibility that large artery vasculopathy will be present in a proportion of patients irradiated for ALL. The long lag time between irradiation and the development of meningioma may mean that, as survivors of childhood ALL enter their third decade since cure, this tumour may be seen increasingly.- - - - - - - - - - ranking = 0.5keywords = radiation-induced (Clic here for more details about this article) |
5/6. Case report: radiation-induced vasculopathy implicated by depressed blood flow and metabolism in a pineal glioma.A case of radiation-induced vasculopathy of a pineal glioma was presented with haemodynamic and metabolic changes before and after radiotherapy. After radiation of 60 Gy with conventional fractionation (1.8-2.0 Gy daily, 5 days per week), regional blood flow, oxygen extraction fraction, metabolic rate of oxygen, kinetic metabolic rate of glucose and the rate constants (K2, K3) were markedly depressed (20% or greater) compared with the pre-irradiated study. 7 months after radiotherapy, the patient developed transient transient episodes of both right and left upper limb convulsion, terminating in generalized convulsion. When she developed status epilepticus, computed tomography showed extensive low density areas in the territory supplied by the right middle cerebral and the right posterior cerebral arteries. cerebral angiography revealed diffuse stenosis at both carotid bifurcations and at the origins of the right posterior communicating and posterior cerebral arteries. Haemodynamic and metabolic depression therefore implicated radiation-induced vasculopathy in the present case.- - - - - - - - - - ranking = 3keywords = radiation-induced (Clic here for more details about this article) |
6/6. Intracranial arterial occlusion associated with high-activity iodine-125 brachytherapy for glioblastoma.We describe two patients who developed devastating strokes due to intracranial arterial occlusion 15 weeks and 97 weeks following high dose stereotactic iodine-125 brachytherapy for glioblastoma multiforme. In both cases the occlusion was within the implant volume at points receiving 110-281 Gy and there was no other evidence of significant atherosclerosis in the patients. We therefore conclude that these complications were a direct result of the brachytherapy. The phenomenon of radiation-induced occlusion of large cerebral arteries is reviewed.- - - - - - - - - - ranking = 0.5keywords = radiation-induced (Clic here for more details about this article) |