RESUMEN
BACKGROUND/AIM: To describe clinical features, radiotherapy (RT), and symptom outcomes in cancer patients with cranial nerve palsies associated with clival metastases. PATIENTS AND METHODS: This is a retrospective review of patients with primary metastatic cancers who developed clival metastases and received RT (2000-2020). RESULTS: Of the 44 patients with primary cancers (manly breast, prostate and multiple myeloma cancers) and distal clival metastases, 32 patients (73%) also had cervical spine metastases. Of the 23 RT-treated patients, 65% and 35% received clivus only and whole brain RT, respectively. Post-RT symptom improvement was observed in patients with diplopia (5/6; 83%), headache (8/10; 80%), chin numbness (2/4; 50%), blurry vision (2/5; 40%), lateral gaze deficit (2/6; 33%), and tongue deviation (1/4; 25%). CONCLUSION: Early detection and cranial nerve examination, in addition to RT treatment, should be considered in patients with breast, prostate, and multiple myeloma cancers, who developed cervical spine metastases.
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Fosa Craneal Posterior/patología , Neoplasias/patología , Neoplasias de la Base del Cráneo/secundario , Evaluación de Síntomas/métodos , Adulto , Anciano , Anciano de 80 o más Años , Fosa Craneal Posterior/efectos de la radiación , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/radioterapia , Pronóstico , Estudios Retrospectivos , Neoplasias de la Base del Cráneo/radioterapia , Tasa de SupervivenciaRESUMEN
OBJECTIVE: The aims of this study were to characterize the epidemiologic, histologic, and radiologic aspects of sphenopetroclival meningiomas (SpPCMs) and to evaluate the outcome of Gamma Knife radiosurgery (GKRS) either as an adjunct to microsurgery or as a primary SpPCM treatment modality. METHODS: In this retrospective study, medical records of patients with SpPCM who underwent GKRS at the Iran Gamma Knife Center between April 2003 and March 2012 were analyzed. RESULTS: We assessed 122 patients with SpPCMs, including 101 women and 21 men, aged 24-94 years. The mean tumor volume was 12.24 ± 9.30 mL. Patients received 22.32 ± 3.29 Gy and 13.18 ± 1.02 Gy maximal and average marginal dose of GKRS, respectively. The most common complaint was visual impairment, followed by facial sensory impairment and headache. The most frequently involved cranial nerves were III, IV, and VI in 72.1% of patients, followed by II in 52.9%, and V in 35.5%. After radiosurgery, headaches improved in 90.0%, diplopia in 75.0%, and ptosis in 63.0% of patients. On magnetic resonance imaging, tumor size was reduced, unchanged, or increased in 77, 44, and 1 patient, respectively. Progression-free survival at the 5-year follow-up was 56.6%. Younger age (hazard ratio = 0.972, P = 0.011) and lower tumor volume (hazard ratio = 0.959, P = 0.009) were the main prognostic factors for progression-free survival. CONCLUSION: GKRS can be an effective alternative treatment for controlling the progression of SpPCM tumors, producing appropriate clinical outcomes and few complications.
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Neoplasias Meníngeas/mortalidad , Neoplasias Meníngeas/radioterapia , Meningioma/mortalidad , Meningioma/radioterapia , Traumatismos por Radiación/mortalidad , Radiocirugia/mortalidad , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Terapia Combinada/mortalidad , Terapia Combinada/estadística & datos numéricos , Fosa Craneal Posterior/patología , Fosa Craneal Posterior/efectos de la radiación , Supervivencia sin Enfermedad , Femenino , Humanos , Irán/epidemiología , Masculino , Neoplasias Meníngeas/patología , Meningioma/patología , Microcirugia/mortalidad , Microcirugia/estadística & datos numéricos , Persona de Mediana Edad , Proyectos Piloto , Traumatismos por Radiación/prevención & control , Radiocirugia/estadística & datos numéricos , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Clival chordomas frequently recur because of their location and invasiveness. OBJECTIVE: To investigate clinical, operative, and anatomic factors associated with clival chordoma recurrence. METHODS: Retrospective review of clival chordomas treated at our center from 1993 to 2013. RESULTS: Fifty patients (56% male) with median age of 59 years (range, 8-76) were newly diagnosed with clival chordoma of mean diameter 3.3 cm (range, 1.5-6.7). Symptoms included headaches (38%), diplopia (36%), and dysphagia (14%). Procedures included transsphenoidal (n=34), transoral (n=4), craniotomy (n=5), and staged approaches (n=7). Gross total resection (GTR) rate was 52%, with 83% mean volumetric reduction, values that improved over time. While the lower third of the clivus was the least likely superoinferior zone to contain tumor (upper third=72%/middle third=82%/lower third=42%), it most frequently contained residual tumor (upper third=33%/middle third=38%/lower third=63%; P<.05). Symptom improvement rates were 61% (diplopia) and 53% (headache). Postoperative radiation included proton beam (n=19), cyberknife (n=7), intensity-modulated radiation therapy (n=6), external beam (n=10), and none (n=4). At last follow-up of 47 patients, 23 (49%) remain disease-free or have stable residual tumor. Lower third of clivus progressed most after GTR (upper/mid/lower third=32%/41%/75%). In a multivariate Cox proportional hazards model, male gender (hazard ratio [HR]=1.2/P=.03), subtotal resection (HR=5.0/P=.02), and the preoperative presence of tumor in the middle third (HR=1.2/P=.02) and lower third (HR=1.8/P=.02) of the clivus increased further growth or regrowth, while radiation modality did not. CONCLUSION: Our findings underscore long-standing support for GTR as reducing chordoma recurrence. The lower third of the clivus frequently harbored residual or recurrent tumor, despite staged approaches providing mediolateral (transcranial+endonasal) or superoinferior (endonasal+transoral) breadth. There was no benefit of proton-based over photon-based radiation, contradicting conventional presumptions.
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Cordoma/patología , Cordoma/terapia , Fosa Craneal Posterior/patología , Recurrencia Local de Neoplasia/epidemiología , Neoplasias de la Base del Cráneo/patología , Neoplasias de la Base del Cráneo/terapia , Adolescente , Adulto , Anciano , Niño , Cordoma/mortalidad , Fosa Craneal Posterior/efectos de la radiación , Fosa Craneal Posterior/cirugía , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Radioterapia Adyuvante , Estudios Retrospectivos , Neoplasias de la Base del Cráneo/mortalidad , Adulto JovenRESUMEN
Cranial radiotherapy could cause several types of vasculopathies, which include atherosclerotic occlusive diseases, moyamoya disease, and aneurysm formation. To our knowledge, radiation-induced aneurysms of the internal carotid artery (ICA) are extremely rare. Here, we report a 68-year-old woman who presented with external ophthalmoplegia caused by radiotherapy after the transsphenoidal surgery for metastastic tumor of the clivus region, and the angiography demonstrated a giant aneurysm of the cavernous ICA. After the ICA ligation, the patient recovered well without brain ischemia with a 6-month-long follow-up. The present case is extremely rare with external opthalmoplegia caused by the giant cavernous ICA aneurysm, and the radiotherapy after transsphenoidal surgery might have been critical in the formation of the aneurysm.
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Enfermedades de las Arterias Carótidas/etiología , Arteria Carótida Interna/efectos de la radiación , Aneurisma Intracraneal/etiología , Oftalmoplejía/etiología , Neoplasias de la Base del Cráneo/radioterapia , Adenoma/radioterapia , Anciano , Enfermedades de las Arterias Carótidas/diagnóstico , Enfermedades de las Arterias Carótidas/cirugía , Arteria Carótida Interna/cirugía , Fístula del Seno Cavernoso de la Carótida/diagnóstico , Fístula del Seno Cavernoso de la Carótida/cirugía , Seno Cavernoso/patología , Fosa Craneal Posterior/efectos de la radiación , Femenino , Estudios de Seguimiento , Humanos , Aneurisma Intracraneal/diagnóstico , Aneurisma Intracraneal/cirugía , Ligadura , Oftalmoplejía/diagnóstico , Neoplasias de la Base del Cráneo/secundarioAsunto(s)
Carcinoma de Células Escamosas/secundario , Fosa Craneal Posterior/efectos de la radiación , Irradiación Craneana/efectos adversos , Apófisis Odontoides/efectos de la radiación , Osteorradionecrosis/diagnóstico , Cuadriplejía/etiología , Compresión de la Médula Espinal/etiología , Enfermedades de la Columna Vertebral/diagnóstico , Tejido Adiposo/patología , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/radioterapia , Fosa Craneal Posterior/patología , Descompresión Quirúrgica , Diagnóstico Diferencial , Duramadre/patología , Espacio Epidural , Fibrosis , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/radioterapia , Neoplasias Inducidas por Radiación/diagnóstico , Apófisis Odontoides/patología , Osteorradionecrosis/etiología , Osteorradionecrosis/cirugía , Neoplasias Faríngeas/radioterapia , Compresión de la Médula Espinal/cirugía , Enfermedades de la Columna Vertebral/etiología , Enfermedades de la Columna Vertebral/cirugía , Fusión VertebralRESUMEN
BACKGROUND: This study investigated the relevance of prognostic factors and the impact of histological features in posterior fossa ependymoma. METHODS: The charts of 26 patients (aged 1-59 years, mean 20.6 years; 11 adults) with posterior fossa ependymoma operated on between January 1983 and December 1994 were reviewed and patients followed up (mean: 93 months). RESULTS: Gross total resection was performed in 18 patients (69%), subtotal in seven patients (27%), biopsy in one patient (4%). One patient (3.8%) developed respiratory complications and died. All patients underwent posterior fossa radiotherapy (5000 cGy) after surgery. Four children first received chemotherapy and then radiotherapy only when at least 3 years old. Eleven patients (42%) received radiotherapy and subsequently chemotherapy. The 5-year survival rate was 90% for adults and 40% for children (
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Neoplasias Encefálicas , Ependimoma , Cuarto Ventrículo/cirugía , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/terapia , Niño , Preescolar , Terapia Combinada , Fosa Craneal Posterior/efectos de la radiación , Fosa Craneal Posterior/cirugía , Ependimoma/mortalidad , Ependimoma/patología , Ependimoma/terapia , Femenino , Estudios de Seguimiento , Cuarto Ventrículo/efectos de la radiación , Humanos , Lactante , Masculino , Persona de Mediana Edad , Dosificación Radioterapéutica , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: The purpose of this study was to determine risk factors that affect locoregional control of nasopharyngeal carcinoma (NPC) after radiotherapy. Computed tomography (CT) is utilized for radiotherapy planning and for identifying high risk anatomic areas. METHODS: Between April 1990 and December 1993, 40 consecutive patients (1 in Stage I, 3 in Stage II, 5 in Stage III, and 31 in Stage IV) who had locoregional NPC were given definitive radiotherapy at the Koo Foundation Sun Yat-Sen Cancer Center in Taipei, Taiwan. All patients had individualized CT treatment planning. The dimension of each tumor as shown on the treatment planning CT were mapped on conventional simulation films. The extent of each tumor was further affirmed by magnetic resonance imaging (MRI) and the tumor map revised as necessary. The primary radiation fields were designed to include the primary tumor and potential spread areas with appropriate margins. Concurrent chemotherapy was also given to 35 patients (87.5%) who had positive cervical lymph nodes or primary tumors extending beyond the nasopharynx. RESULTS: By the end of December 1995, after a median follow-up of 42 months and minimal follow-up of 24 months, the locoregional control rate at 4 years was 84.8% (95% confidence interval [CI], 72.3-97.3), disease free survival 68.4% (95% CI, 52. 1-84.7), and overall survival 76.7% (95% CI, 63.4-90.0). The radiation field margin near the sphenoid sinus averaged 1.9 cm, the clivus margin 1.1 cm, the pterygoid fossa margin 2.0 cm, and the oral cavity margin 1.7 cm. Risk factor analysis revealed that T classification and the radiation field margin at the clivus were the most important factors for locoregional control of the tumor. The locoregional control rates were 92.6% (25/27) for T1-T3 patients and 76.9% (10/13) for T4 patients (P = 0.03). The locoregional control rates were 71.4% (5/7) for patients with a clivus margin < 1 cm and 90.6% (29/32) for patients with a clivus margin > or = 1 cm (P = 0.08). CONCLUSIONS: The excellent locoregional control observed in this series may be attributed to the concurrent chemotherapy and radiotherapy as well as meticulous treatment planning with CT and MRI. The precise delineation of the involved area with the aid of CT, which is taken while the patient is in the position for irradiation, serves to define the necessary safety margin of the radiation field. T classification and clivus margin are the most important factors in determining locoregional control of radiotherapy of NPC. The statistical trend observed in this study indicated that the clivus margin should be adequate to reduce the failure around the clivus, as all local recurrences were observed in this area.
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Carcinoma/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Recurrencia Local de Neoplasia/prevención & control , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma/clasificación , Carcinoma/patología , Terapia Combinada , Simulación por Computador , Intervalos de Confianza , Fosa Craneal Posterior/patología , Fosa Craneal Posterior/efectos de la radiación , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Ganglios Linfáticos/efectos de los fármacos , Ganglios Linfáticos/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Boca/patología , Boca/efectos de la radiación , Neoplasias Nasofaríngeas/clasificación , Neoplasias Nasofaríngeas/patología , Invasividad Neoplásica , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Planificación de la Radioterapia Asistida por Computador , Factores de Riesgo , Seguridad , Hueso Esfenoides/patología , Hueso Esfenoides/efectos de la radiación , Seno Esfenoidal/patología , Seno Esfenoidal/efectos de la radiación , Tasa de Supervivencia , Tomografía Computarizada por Rayos XRESUMEN
We report a case of a radiation-induced spinal cord glioma. A 20-year-old girl presented with neck pain and new significant neurological deficits 17 years after resection of a posterior fossa medullomyoblastoma and subsequent craniospinal irradiation. She was found to have a cervical intramedullary tumor that was resected using a standard microsurgical technique. The permanent histopathological diagnosis was anaplastic astrocytoma. Her neurological status was worse immediately following the operation. She improved to her pre-operative status, but then had a relentless neurological decline resulting in death 16 weeks following surgery. Because of the high incidence of malignancy in the few radiation-induced spinal cord gliomas reported in the literature, and the poor outcome independent of therapy in patients with malignant spinal cord gliomas, an initial strategy of biopsy only may be more appropriate than attempted resection for the patient with a suspected radiation-induced intramedullary spinal cord tumor.
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Astrocitoma/etiología , Neoplasias Encefálicas/radioterapia , Fosa Craneal Posterior/efectos de la radiación , Meduloblastoma/radioterapia , Neoplasias Inducidas por Radiación/etiología , Neoplasias de la Médula Espinal/etiología , Adulto , Astrocitoma/patología , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Preescolar , Fosa Craneal Posterior/patología , Fosa Craneal Posterior/cirugía , Resultado Fatal , Femenino , Humanos , Imagen por Resonancia Magnética , Meduloblastoma/patología , Meduloblastoma/cirugía , Neoplasias Inducidas por Radiación/patología , Neoplasias de la Médula Espinal/patologíaRESUMEN
Craniospinal irradiation (CSI) is an essential component of the therapy of medulloblastoma. Because medulloblastoma disseminates via the cerebrospinal fluid (CSF), CSI technique involves the irradiation of all CSF-bearing areas which are at risk for tumor seeding. Underdosing with radiation because of inadequacies in CSI technique will produce dose "cold spots" which have the potential of serving as a nidus for tumor recurrence. A simple mathematic model of subclinical disease in medulloblastoma based on the available data concerning the radiosensitivity of medulloblastoma cell lines as well as the known clinical dose-response relationships support the hypothesis that for most cases of medulloblastoma, the radiotherapist is working in a range of doses arrayed on the steep portion of the tumor control probability curve. Underdosing of CSF-bearing areas because of technical problems at the junction of the cranial and spinal fields of irradiation, placement of shielding blocks in the cribiform plate-subfrontal region, and/or anatomic errors in the design of the caudal end of the CSI fields may lead to significant risks of tumor relapse. One may debate the necessity of a posterior fossa boost encompassing the entire anatomic posterior fossa rather than the primary tumor volume with a margin. This review critically evaluates the potential impact of CSI technique upon the outcome of treatment for medulloblastoma, and suggests future areas of inquiry.
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Neoplasias Cerebelosas/radioterapia , Meduloblastoma/radioterapia , Líquido Cefalorraquídeo/efectos de la radiación , Fosa Craneal Posterior/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Humanos , Recurrencia Local de Neoplasia , Médula Espinal/efectos de la radiación , Células Tumorales Cultivadas/efectos de la radiaciónRESUMEN
PURPOSE: To determine in a prospective randomized trial the effect on survival, progression-free survival, and patterns of relapse of a decrease in the neuraxis radiation dose from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions in patients with newly diagnosed medulloblastoma between 3 and 21 years of age with low T stage (T1, T2 and T3A), minimal postoperative residual tumor, and no evidence of dissemination (M0). METHODS AND MATERIALS: Between June 1986 and November 1990, the Children's Cancer Group and the Pediatric Oncology Group randomized 126 patients in a two-arm study comparing the two different doses of neuraxis irradiation. In both arms, the posterior fossa received 5,400 cGy in 30 fractions. All patients were staged with myelography, postoperative lumbar cerebrospinal fluid cytology, and postoperative contrast-enhanced cranial computerized tomography to ensure no evidence of dissemination and no more than 1.5 cm3 residual tumor volume. Overall survival, progression-free survival, and patterns of recurrence were carefully monitored. Prospective endocrine and psychometric studies were performed to determine the benefit of decreasing the neuraxis radiation dose. RESULTS: Following an interim analysis at a median time on study of 16 months, the study was closed, since a statistically significant increase was observed in the number of all relapses as well as isolated neuraxis relapses in patients randomized to the lower dose of neuraxis radiation. CONCLUSIONS: In patients with newly diagnosed medulloblastoma considered to have a good prognosis on the basis of low T stage, minimal residual tumor after at least subtotal resection, and no evidence of dissemination after thorough evaluation, there is an increased risk of early relapse associated with lowering the dose of neuraxis radiation from 3,600 cGy in 20 fractions to 2,340 cGy in 13 fractions.
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Encéfalo/efectos de la radiación , Fosa Craneal Posterior/efectos de la radiación , Meduloblastoma/radioterapia , Neoplasias de la Base del Cráneo/radioterapia , Adolescente , Adulto , Encéfalo/patología , Niño , Preescolar , Protocolos Clínicos , Fosa Craneal Posterior/patología , Humanos , Meduloblastoma/patología , Sistemas Neurosecretores/fisiología , Estudios Prospectivos , Dosificación Radioterapéutica , Neoplasias de la Base del Cráneo/patologíaRESUMEN
The purpose of this study was to determine the respective parts played by cerebral hemisphere irradiation, posterior fossa irradiation, and surgery in the poor late functional results often observed in children treated for medulloblastoma. To do this we compared the intellectual outcome in a series of 59 children operated on for medulloblastoma, who had received whole-brain irradiation, to that observed in a series of 37 children operated on for ependymoma of the posterior fossa, who had received radiotherapy only on the posterior fossa. Only patients who had survived for more than 2 years without recurrence were included. At the assessment 1 year after treatment, intellectual outcome was somewhat better in the ependymoma group, but the difference was not statistically significant. At the long-term follow-ups at 5 and 10 years the results remained stable in the children treated for ependymoma, around 60% having an IQ above 90, whereas the intellectual level of the children treated for medulloblastoma was seen to have deteriorated progressively: 20% had an IQ above 90 5 years after treatment and only 10% at the 10-year follow-up. This progressive degradation is most likely due to the irradiation of the cerebral hemispheres, as this prophylactic irradiation constituted the only difference between the two groups. Moreover, irradiation to the posterior fossa did not seem to affect intellectual functions, since in the group of children with ependymomas the proportion of IQs above 90 was high and remained stable over the years. Surgery was certainly responsible for some poor results. The percentage of IQs above 90 observed 1-2 years after treatment was between 70 and 80 when no postoperative complications occurred, and only between 20-40% in the presence of postoperative complications. Postoperative aggravation was in most cases related to a brain-stem lesion. These results encourage the reduction, when possible, of irradiation to the cerebral hemispheres and underline the importance of the quality of surgery.
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Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Fosa Craneal Posterior/efectos de la radiación , Fosa Craneal Posterior/cirugía , Ependimoma/rehabilitación , Ependimoma/cirugía , Inteligencia , Radioterapia/efectos adversos , Logro , Adolescente , Neoplasias Encefálicas/patología , Tronco Encefálico/patología , Tronco Encefálico/efectos de la radiación , Niño , Preescolar , Fosa Craneal Posterior/patología , Ependimoma/patología , Estudios de Seguimiento , Humanos , Pruebas de Inteligencia , Imagen por Resonancia Magnética , Complicaciones Posoperatorias , Radiocirugia , Tomografía Computarizada por Rayos XRESUMEN
From 1974 to 1988, 15 adult patients (aged over 16 years) with cerebellar medulloblastomas were observed in our Neurosurgical Department. All were treated by total (8 patients) or subtotal (7 patients) resection of the tumor, followed by radiation therapy to the posterior cranial fossa, spine and whole brain. A 5-year survival was achieved in 7 patients (46.6%). Local tumor recurrence occurred in 4 patients. The best treatment and the factors that influence the prognosis and survival of adult medulloblastomas are discussed also from the analysis of the pertinent literature.
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Neoplasias Cerebelosas/patología , Cerebelo/patología , Meduloblastoma/patología , Adolescente , Adulto , Neoplasias Cerebelosas/radioterapia , Neoplasias Cerebelosas/cirugía , Cerebelo/efectos de la radiación , Fosa Craneal Posterior/efectos de la radiación , Femenino , Humanos , Presión Intracraneal , Masculino , Meduloblastoma/radioterapia , Meduloblastoma/cirugía , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores SexualesRESUMEN
A 14-year-old boy was diagnosed as having a medulloblastoma in the posterior fossa. Radiation therapy was given and the patient made a good recovery. Three months later he presented with supraclavicular lymph node metastasis, in the absence of other foci of metastases. He was treated with 60Co and the metastasis decreased. Two months later a bone scan and bone marrow aspiration showed bone metastasis. He was started on chemotherapy. The different possible mechanisms of metastasis are discussed.
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Neoplasias Encefálicas/patología , Fosa Craneal Posterior/patología , Ganglios Linfáticos/patología , Meduloblastoma/patología , Metástasis de la Neoplasia , Adolescente , Neoplasias Óseas/secundario , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Fosa Craneal Posterior/efectos de la radiación , Fosa Craneal Posterior/cirugía , Humanos , Ganglios Linfáticos/efectos de la radiación , Ganglios Linfáticos/cirugía , Masculino , Meduloblastoma/radioterapia , Meduloblastoma/cirugía , Articulación Sacroiliaca/patologíaRESUMEN
The aim of this study was first to determine the effect of use of different scan planes at computed tomography (CT) of the brain on lens radiation dose and on severity of posterior fossa artifact. Twenty patients requiring nonenhanced and contrast material-enhanced brain CT scanning were selected. Each was scanned with two different beam angulations, one passing through the eyes and one avoiding them, and the resulting radiation doses were measured. Angling of the beam to avoid the orbit reduced the dose by 87%, while the severity of posterior fossa artifacts was not significantly different. Second, the implications of these results was assessed by means of an international questionnaire survey of current scanning technique. Only 32% of the respondents routinely avoided the eye during brain CT. No single scan plane was accepted by the respondents as being superior in terms of minimizing posterior fossa artifact. The authors conclude that the potential exists for a reduction in lens dose after reappraisal of radiologic practice in brain CT.