1/73. dementia following treatment of brain tumors with radiotherapy administered alone or in combination with nitrosourea-based chemotherapy: a clinical and pathological study.A retrospective clinical and pathological study of 4 patients who developed the syndrome of radiation induced dementia was performed. All patients fulfilled the following criteria: (1) a history of supratentorial irradiation; (2) no evidence of symptomatic recurrent tumor; (3) no other cause of progressive cerebral dysfunction and dementia. The clinical picture consisted of a progressive "subcortical" dementia occurring 3-12 months after a course of cerebral radiotherapy. Examination revealed early bilateral corticospinal tract involvement in all patients and dopa-resistant Parkinsonian syndrome in two. On CT scan and MRI of the brain, the main features consisted of progressive enlargement of the ventricles associated with a diffuse hypodensity/hyperintensity of the white matter best seen on T2 weighted images on MRI. The course was progressive over 8-48 months in 3 patients while one patient had stabilization of his condition for about 28 years. Treatment with corticosteroids or shunting did not produce sustained improvement and all patients eventually died. Pathological examination revealed diffuse white matter pallor with sparing of the arcuate fibers in all patients. Despite a common pattern on gross examination, microscopic studies revealed a variety of lesions that took two basic forms: (1) a diffuse axonal and myelin loss in the white matter associated with tissue necrosis, particularly multiple small foci of necrosis disseminated in the white matter which appeared different from the usual "radionecrosis"; (2) diffuse spongiosis of the white matter characterized by the presence of vacuoles that displaced the normally-stained myelin sheets and axons. Despite a rather stereotyped clinical and radiological course, the pathological substratum of radiation-induced dementia is not uniform. Whether the different types of white matter lesions represent the spectrum of a single pathological process or indicate that the pathogenesis of this syndrome is multifactorial with different target cells, remains to be seen.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
2/73. Gamma surgery for intracranial metastases from renal cell carcinoma.OBJECT: The goal of this study was to evaluate the effectiveness and limitations of gamma surgery (GS) in the treatment of renal cell carcinoma that has metastasized to the brain. methods: The authors performed a retrospective analysis of a consecutive series of 21 patients with 37 metastatic brain deposits from renal cell carcinoma who were treated with GS at the University of virginia from 1990 to 1999. Clinical data were available in all patients. No patient died of progression of intracranial disease or deteriorated neurologically following GS. Eight patients clinically improved. Follow-up imaging studies were available for 23 tumors in 12 patients. Nine patients did not undergo follow-up imaging. One patient lived 17 months and succumbed to systemic disease: no brain imaging was performed in this case. Another patient refused further imaging and lived 7 months. Seven patients lived up to 4 months after the procedure; however, their physicians did not require these patients to undergo follow-up imaging examinations because of their general conditions-all had systemic progression of disease. Of the 23 tumors that were observed posttreatment, one remained unchanged in volume, 16 decreased in volume, and six disappeared. No tumor progressed at any time, and there were no radiation-induced changes on follow-up imaging an average of 21 months after GS (range 3-63 months). CONCLUSIONS: Gamma surgery provides an alternative to surgical resection of metastatic brain deposits from renal cell carcinoma. Neurological side effects were seen in only one case; freedom from progression of disease was achieved in all cases.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
3/73. Secondary intracranial meningiomas after high-dose cranial irradiation: report of five cases and review of the literature.PURPOSE: To review cases of secondary intracranial meningiomas following high-dose cranial irradiation (>/= 10 Gy) identified in slovenia between 1968 and 1998, to determine their histological profile and to review the literature on this topic. methods AND MATERIALS: Personal files of patients treated for secondary intracranial meningioma during a 31-year period were reviewed. In cases which met the criteria for radiation-induced tumors, steroid hormone receptor and Ki-67 status were analyzed. For the literature review, computerized database systems and reference lists from respective publications were used. RESULTS: Five patients (2 females, 3 males), 3-11 years old at the time of cranial irradiation, developed secondary meningioma after a latency period of 9.5-31.5 years. Three patients had multiple tumors and 2 developed recurrent disease. Of 9 histologically examined tumors, 5 were graded as benign and 4 as atypical meningiomas, with Ki-67 proliferative index 3.2 /- 3.6 and 10 /- 6, respectively. The ratio between positive and negative meningiomas regarding immunostaining for progesterone and estrogen receptors was eight-to-one and six-to-three, respectively. Cumulative actuarial risk of secondary meningioma in a cohort of 445 children 16 years or younger treated with high-dose cranial irradiation between 1968 and 1990 in slovenia at 10, 20, and 25 years was 0.53%, 1.2%, and 8.18%, respectively. Out of 126 cases of radiation-induced meningiomas reported, 57% were females and 43% were males, with mean age at presentation 33 /- 17.3 years. The majority (68%) of patients was irradiated during childhood. The latency period was significantly shorter in those who aged 5 years or less at the time of cranial irradiation (p = 0.04), and in those with atypical/anaplastic tumor (p = 0.01). Correlation between radiation dose and latency period could not be found. CONCLUSION: Secondary meningiomas following high-dose cranial irradiation are characterized by younger age at presentation, by higher male-to-female ratio and by biologically more aggressive variants compared to primary spontaneous meningiomas. Latency period correlated with the age at the time of cranial irradiation and with tumor grade but not with irradiation dose. Ki-67 immunoreactivity correlated with histological grade. The progesterone and estrogen receptor immunoreactivity was high. The risk for development of secondary meningioma after high-dose cranial irradiation was increasing with the time of follow-up.- - - - - - - - - - ranking = 2keywords = radiation-induced (Clic here for more details about this article) |
4/73. 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 = 2keywords = radiation-induced (Clic here for more details about this article) |
5/73. optic nerve sheath fenestration for a reversible optic neuropathy in radiation oncology.To the authors' knowledge, there is a paucity of published accounts of management of radiation-induced optic neuropathy (RION) by optic nerve sheath fenestration (ONSF) in the conventional medical literature. With higher doses of radiation being given by using conformal techniques, more radiation-induced optic neuritis and neuropathy will be identified. We report here the successful use of ONSF to restore vision to three consecutive patients with pending anterior RION, and the importance of early identification and intervention in these potentially reversible cases.- - - - - - - - - - ranking = 2keywords = radiation-induced (Clic here for more details about this article) |
6/73. L-dopa-resistant parkinsonism syndrome following cerebral radiation therapy for neoplasm.A bradykinetic form of parkinsonism, unresponsive to levo-dopa therapy developed in four patients two to eight weeks after completion of external beam irradiation (39.2 Gy to 59.4 Gy) of their intracranial neoplasm. In the absence of other causative factors, we relate the movement disorder to radiation-induced changes within the basal ganglia. At post-mortem examination one patient had putamenal gliosis and thickened vessels with loss of nigral neurons.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
7/73. glioblastoma multiforme occurring in a patient treated with gamma knife surgery. Case report and review of the literature.Stereotactic radiosurgery is being increasingly advocated as the primary modality for treatment of vestibular schwannomas (VS). This modality has been shown to arrest tumor growth, with few associated short-term morbidities, and with possibly better hearing and facial nerve preservation rates than microsurgery. Radiation-induced oncogenesis has long been recognized, although stereotactic radiosurgery de novo induction of a secondary tumor has never been clearly described. The authors report on a patient with a VS who did not have neurofibromatosis Type 2 and who underwent gamma knife surgery (GKS). This patient required microsurgical removal of the VS within 8 months because of development of a tumor cyst with associated brainstem compression and progressive hydrocephalus. The operation resulted in clinical stabilization and freedom from tumor recurrence. Seven and a half years after undergoing GKS, the patient presented with symptoms of raised intracranial pressure. magnetic resonance imaging demonstrated a new ring-enhancing lesion in the inferior temporal lobe adjacent to the area of radiosurgery, which on craniotomy was confirmed to be a glioblastoma multiforme (GBM). Despite additional conventional external-beam radiation to the temporal lobe, the GBM has progressed. Whereas this first reported case of a GBM within the scatter field of GKS does not conclusively prove a direct causal link, it does fulfill all of Cahan's criteria for radiation-induced neoplasia, and demands increased vigilance for the potential long-term complications of stereotactic radiosurgery, and reporting of any similar cases.- - - - - - - - - - ranking = 1keywords = radiation-induced (Clic here for more details about this article) |
8/73. Radiation-induced meningiomas involving the orbit.PURPOSE: To review the clinical features and outcomes of patients with radiation-induced meningiomas involving the orbit. DESIGN: Retrospective case series. PARTICIPANTS: Eight patients with radiation-induced meningiomas affecting the orbit. methods: Clinical and pathologic data of the patients were reviewed. MAIN OUTCOME MEASURES: Age at diagnosis, mean interval between radiation therapy and meningioma diagnosis, tumor recurrence, histologic atypia, and mean follow-up time after initial diagnosis. RESULTS: The mean age at diagnosis was 42 years (range, 21 years to 70 years). The mean interval between radiation therapy and meningioma diagnosis was 26 years (range, 3 years to 54 years). All patients underwent gross total resection or subtotal resection of the meningioma. Five tumors (62.5%) recurred, based on clinical findings and CT imaging. The mean interval between resection of the meningioma and recurrence was 3 years (range, 9 months to 9 years). Three patients (37.5%) had atypical meningiomas. One patient (12.5%) had multiple tumors. The mean follow-up interval was 7 years after initial diagnosis of the meningioma (range, 15 months to 19 years). CONCLUSIONS: This series of radiation-induced meningiomas, the first in the ophthalmic literature, illustrates the aggressive nature of this tumor.- - - - - - - - - - ranking = 3keywords = radiation-induced (Clic here for more details about this article) |
9/73. Successful treatment of radiation-induced brain necrosis by hyperbaric oxygen therapy.We describe a 68-year-old man who underwent hyperbaric oxygen (HBO) therapy to manage radiation necrosis of the brain, which developed after two treatments with stereotactic radiosurgery (SRS) to the same lesion. The necrosis was subsequently treated with steroids alone for 2 months; however, he progressed clinically and radiographically. Improvement again was noted with the reinstitution of HBO therapy. This case suggests that HBO therapy is an important therapeutic option in the treatment of brain radiation necrosis caused by SRS.- - - - - - - - - - ranking = 4keywords = radiation-induced (Clic here for more details about this article) |
10/73. Radiation-induced gliomas: report of 10 cases and review of the literature.BACKGROUND: radiotherapy and more recently radiosurgery represent important therapeutic methods for the treatment of tumors and arterovenous malformations affecting the central nervous system, even though several significant side-effects have been described (radionecrosis, tumors, etc.). Gliomas induced by radiation therapy are decidedly unusual, and the first descriptions of this association only appeared in the 1960s. methods: The pertinent literature was reviewed to yield 116 cases in which a glioma developed after radiotherapy for cranial pathologies (included 10 personal cases treated in our Institution). One of our patients had undergone radiosurgery for a cavernous angioma. RESULTS: patients who developed a radiation-induced glioma were younger, as a group, than those affected with so-called "spontaneous" gliomas. The tumor originated in the previously irradiated area, after average doses of 32 Gy and an average latency period of 9.6 years in accordance with the findings reported by the authors and in our experience as well. radiotherapy had most frequently been performed for acute lymphoblastic leukemia. Our Case 10 is the fourth case of intracranial tumor arising after radiosurgery to be described in the literature. CONCLUSIONS: Though rare, gliomas may represent a late complication of radiation treatment. The behavior of the radiation-induced variety of glioma does not seem to differ significantly from that of its "spontaneous" counterpart. Late complications of the radiosurgery are probably underestimated because of the relatively recent introduction of this technique. On the contrary, these should be scrupulously evaluated when deciding whether to employ this method for therapeutic purposes for relatively benign or congenital lesions (which generally affect young patients with a long life expectancy).- - - - - - - - - - ranking = 2keywords = radiation-induced (Clic here for more details about this article) |
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