The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Peter J Hutchinson - One of the best experts on this subject based on the ideXlab platform.
-
mechanism based mri classification of traumatic Brainstem Injury and its relationship to outcome
Journal of Neurotrauma, 2007Co-Authors: Richard J Mannion, David K Menon, Justin J Cross, John D Pickard, Peter G Bradley, Jonathan P Coles, Doris A Chatfield, Adrian Carpenter, Peter J HutchinsonAbstract:While computed tomography (CT) is the appropriate technique for the urgent detection of hematomas and contusions in the cerebral hemispheres, it is much less effective at documenting diffuse Injury...
-
detecting Brainstem Injury with acute mri following severe head trauma
Journal of Cerebral Blood Flow and Metabolism, 2005Co-Authors: Richard J Mannion, David K Menon, Justin J Cross, Peter Bradbury, Jonathan A Coles, D A Chatfield, John D Pickard, Peter J HutchinsonAbstract:Traumatic brain Injury (TBI) is the most common cause of death and major disability in young people. Outcome is often difficult to predict from factors such as mechanism of Injury, initial Glasgow Coma Score and imaging. Currently, CT is the imaging modality of choice and has led to the introduction of complex CT-based classification systems of head Injury. CT is satisfactory for the detection of haematomas and contusions in the cerebral hemispheres but is much less effective at documenting diffuse Injury and posterior fossa lesions. There are, therefore, a significant number of patients in whom outcome is much worse than would be predicted from their presenting CT scan. This aim of this study is to look at the role of acute MRI (T2, FLAIR, gradient echo) in detecting the presence of Brainstem Injury in patients following TBI and to correlate the findings with outcome at 6 months (Glasgow Outcome Score). Twenty-nine patients (mean age 37 years, range 18-70, 79% male) admitted to the neuro-critical care unit with TBI requiring ventilation underwent CT and MRI within 3 days of Injury. Brainstem lesions were detected in 7 patients on MRI scan but none were diagnosed by CT. The types of Brainstem Injury varied widely and an assessment was made as to whether Injury type had any relationship with the nature of supratentorial Injury. All 7 patients with Brainstem Injury had an unfavorable outcome (death, vegetative state or severe disability). Of the 22 patients without Brainstem lesions, 10 had a poor outcome. The relationship between Brainstem lesions and outcome was highly significant. (p<0.005, Chi Squared Test). This study suggests that early MRI detects a significant number of Brainstem lesions that are not seen on CT and offers the potential to increase our understanding of the nature of supratentorial Injury following head trauma.
Richard J Mannion - One of the best experts on this subject based on the ideXlab platform.
-
mechanism based mri classification of traumatic Brainstem Injury and its relationship to outcome
Journal of Neurotrauma, 2007Co-Authors: Richard J Mannion, David K Menon, Justin J Cross, John D Pickard, Peter G Bradley, Jonathan P Coles, Doris A Chatfield, Adrian Carpenter, Peter J HutchinsonAbstract:While computed tomography (CT) is the appropriate technique for the urgent detection of hematomas and contusions in the cerebral hemispheres, it is much less effective at documenting diffuse Injury...
-
detecting Brainstem Injury with acute mri following severe head trauma
Journal of Cerebral Blood Flow and Metabolism, 2005Co-Authors: Richard J Mannion, David K Menon, Justin J Cross, Peter Bradbury, Jonathan A Coles, D A Chatfield, John D Pickard, Peter J HutchinsonAbstract:Traumatic brain Injury (TBI) is the most common cause of death and major disability in young people. Outcome is often difficult to predict from factors such as mechanism of Injury, initial Glasgow Coma Score and imaging. Currently, CT is the imaging modality of choice and has led to the introduction of complex CT-based classification systems of head Injury. CT is satisfactory for the detection of haematomas and contusions in the cerebral hemispheres but is much less effective at documenting diffuse Injury and posterior fossa lesions. There are, therefore, a significant number of patients in whom outcome is much worse than would be predicted from their presenting CT scan. This aim of this study is to look at the role of acute MRI (T2, FLAIR, gradient echo) in detecting the presence of Brainstem Injury in patients following TBI and to correlate the findings with outcome at 6 months (Glasgow Outcome Score). Twenty-nine patients (mean age 37 years, range 18-70, 79% male) admitted to the neuro-critical care unit with TBI requiring ventilation underwent CT and MRI within 3 days of Injury. Brainstem lesions were detected in 7 patients on MRI scan but none were diagnosed by CT. The types of Brainstem Injury varied widely and an assessment was made as to whether Injury type had any relationship with the nature of supratentorial Injury. All 7 patients with Brainstem Injury had an unfavorable outcome (death, vegetative state or severe disability). Of the 22 patients without Brainstem lesions, 10 had a poor outcome. The relationship between Brainstem lesions and outcome was highly significant. (p<0.005, Chi Squared Test). This study suggests that early MRI detects a significant number of Brainstem lesions that are not seen on CT and offers the potential to increase our understanding of the nature of supratentorial Injury following head trauma.
Erich Schmutzhard - One of the best experts on this subject based on the ideXlab platform.
-
prediction of recovery from post traumatic vegetative state with cerebral magnetic resonance imaging
The Lancet, 1998Co-Authors: A Kampfl, Stefan Felber, Hans-peter Haring, Bettina Pfausler, Erich Schmutzhard, Gerhard Franz, Hanno Ulmer, Stefan Golaszewski, Franz AichnerAbstract:Summary Background The early post-traumatic vegetative state (VS) is compatible with recovery. Various clinical and laboratory tests have failed to predict recovery so we assessed the value of cerebral magnetic-resonance imaging (MRI) in prediction of recovery. Methods 80 adult patients in post-traumatic VS had cerebral MRI between 6 weeks and 8 weeks after Injury. MRIs were reviewed by three neuroradiologists for the number, sizes, and location of brain lesions. Three neurologists assessed the patients at the time of MRI and at 2 months, 3 months, 6 months, 9 months, and 12 months after Injury using the Glasgow Outcome Scale. Findings At 12 months, 38 patients had recovered while 42 patients remained in the VS. The demographic characteristics and causes and severity of Injury were similar in patients in persistent VS (PVS) and those who recovered (NPVS). An average of 6·1 different brain areas were injured in patients in PVS compared with 4·6 areas in patients who had NPVS. Patients in PVS revealed a significantly higher frequency of corpus callosum, corona radiata, and dorsolateral Brainstem injuries than did patients who recovered. Logistic regression analysis showed that corpus callosum and dorsolateral Brainstem injuries were predictive of non-recovery. The adjusted odds ratios for non-recovery of patients with a corpus callosum lesion and dorsolateral Brainstem Injury were 213·8 (95% Cl 14·2–3213·3), and 6·9 (1·1–42·9), respectively. In contrast, clinical characteristics, such as initial score on the Glasgow Coma Scale, age, and pupillary abnormalities failed to predict recovery. Interpretation Cerebral MRI findings in the subacute stage after head Injury can predict the outcome of the post-traumatic VS. Corpus callosum and dorsolateral Brainstem lesions are highly significant in predicting non-recovery.
-
the persistent vegetative state after closed head Injury clinical and magnetic resonance imaging findings in 42 patients
Journal of Neurosurgery, 1998Co-Authors: A Kampfl, Stefan Felber, Hans-peter Haring, Bettina Pfausler, Michael Schocke, Franz Aichner, Gerhard Franz, Erich SchmutzhardAbstract:Object. In this retrospective study, the authors analyzed the frequency, anatomical distribution, and appearance of traumatic brain lesions in 42 patients in a posttraumatic persistent vegetative state. Methods. Cerebral magnetic resonance (MR) imaging was used to detect the number of lesions, which ranged from as few as five to as many as 19, with a mean of 11 lesions. In all 42 cases there was evidence on MR imaging of diffuse axonal Injury, and Injury to the corpus callosum was detected in all patients. The second most common area of diffuse axonal Injury involved the dorsolateral aspect of the rostral Brainstem (74% of patients). In addition, 65% of these patients exhibited white matter Injury in the corona radiata and the frontal and temporal lobes. Lesions to the basal ganglia or thalamus were seen in 52% and 40% of patients, respectively. Magnetic resonance imaging showed some evidence of cortical contusion in 48% of patients in this study; the frontal and temporal lobes were most frequently involved. Injury to the parahippocampal gyrus was detected in 45% of patients; in this subgroup there was an 80% incidence of contralateral peduncular lesions in the midbrain. The most common pattern of Injury (74% in this series) was the combination of focal lesions of the corpus callosum and the dorsolateral Brainstem. In patients with no evidence of diffuse axonal Injury in the upper Brainstem (26% in this series), callosal lesions were most often associated with basal ganglia lesions. Lesions of the corona radiata and lobar white matter were equally distributed in patients with or without dorsolateral Brainstem Injury. Moreover, cortical contusions and thalamic, parahippocampal, and cerebral peduncular lesions were also similarly distributed in both groups. Conclusions. The data indicate that diffuse axonal Injury may be the major form of primary brain damage in the posttraumatic persistent vegetative state. In addition, the authors demonstrated in this study that MR imaging, in conjunction with a precise clinical correlation, may provide useful supportive information for the accurate diagnosis of a persistent vegetative state after traumatic brain Injury.
D Giantsoudi - One of the best experts on this subject based on the ideXlab platform.
-
Brainstem Injury in pediatric patients with posterior fossa tumors treated with proton beam therapy and associated dosimetric factors
International Journal of Radiation Oncology Biology Physics, 2017Co-Authors: Michelle S Gentile, Harald Paganetti, Beow Y Yeap, Claire P Goebel, Dillon E Gaudet, Sara L Gallotto, Elizabeth A Weyman, Michael L Morgan, Shannon M Macdonald, D GiantsoudiAbstract:Purpose Proton radiation therapy is commonly used in young children with brain tumors for its potential to reduce late effects. However, some proton series report higher rates of Brainstem Injury (0%-16%) than most photon series (2.2%-8.6%). We report the incidence of Brainstem Injury and a risk factor analysis in pediatric patients with posterior fossa primary tumors treated with proton radiation therapy at our institution. Methods and Materials The study included 216 consecutive patients treated between 2000 and 2015. Dosimetry was available for all but 4 patients. Grade 2 to 5 late Brainstem toxicity was assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Results The histologies include medulloblastoma (n=154, 71.3%), ependymoma (n=56, 25.9%), and atypical teratoid rhabdoid tumor (n=6, 2.8%). The median age at irradiation was 6.6 years (range, 0.5-23.1 years); median dose, 54 gray relative biological effectiveness (Gy RBE) (range, 46.8-59.4 Gy RBE); and median follow-up period, 4.2 years (range, 0.1-15.3 years) among 198 survivors. Of the patients, 83.3% received chemotherapy; 70.4% achieved gross total resection. The crude rate of Injury was 2.3% in all patients, 1.9% in those with medulloblastoma, 3.6% in those with ependymoma, and 0% in those with atypical teratoid rhabdoid tumor. The 5-year cumulative incidence of Injury was 2.0% (95% confidence interval, 0.7%-4.8%). The median Brainstem dose (minimum dose received by 50% of Brainstem) in the whole cohort was 53.6 Gy RBE (range, 16.5-56.8 Gy RBE); maximum point dose within the Brainstem (Dmax), 55.2 Gy RBE (range, 48.4-60.5 Gy RBE); and mean dose, 50.4 Gy RBE (range, 21.1-56.7 Gy RBE). In the 5 patients with Injury, the median minimum dose received by 50% of the Brainstem was 54.6 Gy RBE (range, 50.2-55.1 Gy RBE); Dmax, 56.2 Gy RBE (range, 55.0-57.1 Gy RBE); mean dose, 51.3 Gy RBE (range, 45.4-54.4 Gy RBE); and median volume of the Brainstem receiving ≥55 Gy RBE (V55), 27.4% (range, 0%-59.4%). Of the 5 patients with Injury, 4 had a Brainstem Dmax in the highest quartile (≥55.8 Gy RBE, P = .016) and a V55 in the highest tertile (>6.0%) of the cohort distribution (P = .047). Of the 5 patients with Injury, 3 were aged >6 years (age range, 4.1-22.8 years), and 4 of 5 patients received chemotherapy and achieved gross total resection. Conclusions The incidence of Injury in pediatric patients with posterior fossa tumors is consistent with previous reports in the photon setting. Our data suggest that when Dmax and V55 are kept
-
incidence of cns Injury for a cohort of 111 patients treated with proton therapy for medulloblastoma let and rbe associations for areas of Injury
International Journal of Radiation Oncology Biology Physics, 2016Co-Authors: D Giantsoudi, Beow Y Yeap, Roshan V Sethi, Bree R Eaton, David H Ebb, Paul A Caruso, Otto Rapalino, Yenlin Chen, Judith Adams, Torunn I. YockAbstract:Background Central nervous system (CNS) Injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS Injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values. Methods and Materials We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS Injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models. Results At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS Injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values ( P =.12). Conclusions Central nervous system and Brainstem Injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS Injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between Injury and LET.
Torunn I. Yock - One of the best experts on this subject based on the ideXlab platform.
-
national cancer institute workshop on proton therapy for children considerations regarding Brainstem Injury
International Journal of Radiation Oncology Biology Physics, 2018Co-Authors: Daphne A Haaskoga, Daniel J Indelicato, Harald Paganetti, Natia Esiashvili, Anita Mahaja, Torunn I. Yock, Stella Flampouri, Shanno M Macdonald, Maryam FouladiAbstract:Purpose Proton therapy can allow for superior avoidance of normal tissues. A widespread consensus has been reached that proton therapy should be used for patients with curable pediatric brain tumor to avoid critical central nervous system structures. Brainstem necrosis is a potentially devastating, but rare, complication of radiation. Recent reports of Brainstem necrosis after proton therapy have raised concerns over the potential biological differences among radiation modalities. We have summarized findings from the National Cancer Institute Workshop on Proton Therapy for Children convened in May 2016 to examine Brainstem Injury. Methods and Materials Twenty-seven physicians, physicists, and researchers from 17 institutions with expertise met to discuss this issue. The definition of Brainstem Injury, imaging of this entity, clinical experience with photons and photons, and potential biological differences among these radiation modalities were thoroughly discussed and reviewed. The 3 largest US pediatric proton therapy centers collectively summarized the incidence of symptomatic Brainstem Injury and physics details (planning, dosimetry, delivery) for 671 children with focal posterior fossa tumors treated with protons from 2006 to 2016. Results The average rate of symptomatic Brainstem toxicity from the 3 largest US pediatric proton centers was 2.38%. The actuarial rate of grade ≥2 Brainstem toxicity was successfully reduced from 12.7% to 0% at 1 center after adopting modified radiation guidelines. Guidelines for treatment planning and current consensus Brainstem constraints for proton therapy are presented. The current knowledge regarding linear energy transfer (LET) and its relationship to relative biological effectiveness (RBE) are defined. We review the current state of LET-based planning. Conclusions Brainstem Injury is a rare complication of radiation therapy for both photons and protons. Substantial dosimetric data have been collected for Brainstem Injury after proton therapy, and established guidelines to allow for safe delivery of proton radiation have been defined. Increased capability exists to incorporate LET optimization; however, further research is needed to fully explore the capabilities of LET- and RBE-based planning.
-
incidence of cns Injury for a cohort of 111 patients treated with proton therapy for medulloblastoma let and rbe associations for areas of Injury
International Journal of Radiation Oncology Biology Physics, 2016Co-Authors: D Giantsoudi, Beow Y Yeap, Roshan V Sethi, Bree R Eaton, David H Ebb, Paul A Caruso, Otto Rapalino, Yenlin Chen, Judith Adams, Torunn I. YockAbstract:Background Central nervous system (CNS) Injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS Injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values. Methods and Materials We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS Injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models. Results At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS Injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values ( P =.12). Conclusions Central nervous system and Brainstem Injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS Injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between Injury and LET.