Papers by Jacques Guyotat
Neuro-Oncology, 2015
The diagnosis of primary central nervous system lymphoma (PCNSL) can be challenging. PCNSL lesion... more The diagnosis of primary central nervous system lymphoma (PCNSL) can be challenging. PCNSL lesions are frequently located deep within the brain, and performing a cerebral biopsy is not always feasible. The aim of this study was to investigate the diagnostic value of CSF neopterin, a marker of neuroinflammation, in immunocompetent patients with suspected PCNSL. We retrospectively reviewed the characteristics of 124 patients with brain tumor (n = 82) or an inflammatory CNS disorder (n = 42) in whom CSF neopterin levels were assessed. Twenty-eight patients had PCNSL, 54 patients had another type of brain tumor (glioma n = 36, metastasis n = 13, other n = 5), and 13 patients had a pseudotumoral inflammatory brain lesion. CSF neopterin levels were significantly higher in the patients with PCNSL than in those with other brain tumors (41.8 vs 5.1 nmol/L, P < .001), those with pseudotumoral inflammatory brain lesions (41.8 vs 4.3 nmol/L, P < .001), and those with nontumefactive inflammatory CNS disorders (41.8 vs 3.8 nmol/L, P < .001). In the 95 patients with space-occupying brain lesions, at a cutoff of 10 nmol/L, the sensitivity of this approach was 96% and the specificity was 93% for the diagnosis of PCNSL. The positive and negative predictive values were 84% and 98%, respectively. Assessing CSF neopterin levels in patients with a suspected brain tumor might be helpful for the positive and differential diagnosis of PCNSL. A prospective study is warranted to confirm these results.
Journal of neuro-oncology, Jan 26, 2015
The aim of this study was to assess whether combining multimodal magnetic resonance imaging (MRI)... more The aim of this study was to assess whether combining multimodal magnetic resonance imaging (MRI) with the determination of the 1p/19q codeletion status could improve the ability to predict anaplastic transformation in low-grade oligodendrogliomas. Twenty patients with grade II oligodendrogliomas were followed-up using multimodal MR [proton MR spectroscopy (MRS), perfusion, and conventional MR imaging]. All patients diagnoses were histologically proven, and 1p/19q codeletion status was analyzed for all patients. Median follow-up was 30.5 ± 11.4 months. Anaplastic transformation was observed in six patients. The only MRI feature that was associated with anaplastic transformation was an elevation of the choline/creatine ratio >2.4 which was observed in 4 out of 6 patients with anaplastic transformation versus 1 out of 14 patients without anaplastic transformation. In patients without 1p/19q codeletion, an elevation of the choline/creatine ratio >2.4 was associated with the occur...
Biomedical Optics Express, 2013
5-ALA-induced protoporphyrin IX (PpIX) fluorescence enables to guiding in intra-operative surgica... more 5-ALA-induced protoporphyrin IX (PpIX) fluorescence enables to guiding in intra-operative surgical glioma resection. However at present, it has yet to be shown that this method is able to identify infiltrative component of glioma. In extracted tumor tissues we measured a two-peaked emission in low grade gliomas and in the infiltrative component of glioblastomas due to multiple photochemical states of PpIX. The second emission peak appearing at 620 nm (shifted by 14 nm from the main peak at 634 nm) limits the sensibility of current methods to measured PpIX concentration. We propose new measured parameters, by taking into consideration the two-peaked emission, to overcome these limitations in sensitivity. These parameters clearly distinguish the solid component of glioblastomas from low grade gliomas and infiltrative component of glioblastomas.
Neurosurgical Review, 2010
Grade II gliomas grow slowly and linearly (at rates about 4 mm/year) before undergoing anaplastic... more Grade II gliomas grow slowly and linearly (at rates about 4 mm/year) before undergoing anaplastic transformation. In order to analyze how surgery may affect radiological grade II glioma kinetics, we restrospectively reviewed our national database searching for patients operated on for a supratentorial grade II glioma between 1997 and 2007. We selected patients with at least two postoperative MRI with a minimal delay of 6 months. For each patient, postoperative residues were segmented on successive MRIs. Velocities of diameter expansion were estimated by linear regression of mean diameter evolution for each patient. Fifty-four patients fulfilled inclusion criteria. Median postoperative follow-up was 1.6 years with, on average, 3.4 MRI examinations per patient. Postoperative growth rates of mean diameter were normally distributed, around a mean value of 4.3 mm/year (SD=3.2 mm/year). Statistical analysis showed no difference between this distribution and the distribution of preoperative growth rates in a previous series of 143 grade II gliomas. For a subset of 23 patients, delay between first MRI and surgery made it possible to estimate also preoperative growth rates. Intrapatient comparison revealed that growth rates were grossly unchanged for 80% of cases. In summary, inter-and intrapatient comparison of pre-and postoperative growth rates proves that surgery does not change grade II glioma dynamics, thus, acting as a cytoreduction.
Neurosurgery, 2005
This study was a randomized, multicenter Phase II trial comparing the effect of perioperative imp... more This study was a randomized, multicenter Phase II trial comparing the effect of perioperative implantation of 5-fluorouracil-releasing microspheres followed by early radiotherapy (Arm A) and early radiotherapy alone (Arm B) in patients with gross total resection of high-grade glioma. Patients were randomized on clinical and radiological assumption of supratentorial high-grade glioma. All patients underwent surgery, and after resection and histological confirmation, patients randomized to Arm A received multiple injections of microsphere suspension (130 mg of 5-fluorouracil). Conventional fractionated radiotherapy (59.4 Gy) was initiated between the second and the seventh day after surgery for both arms. A total of 95 patients were randomized. Seventy-seven patients were treated and analyzed in intention to treat for efficacy and safety. Overall survival was 15.2 months in Arm A and 13.5 months in Arm B. In the subpopulation of patients with complete resection, overall survival was 15.2 months in Arm A versus 12.3 months in Arm B. However, these differences were not significant. Safety was acceptable with prophylactic high doses of corticosteroids. It may be hypothesized that the implantation of 5-fluorouracil-loaded microspheres in the wall of the cavity resection did increase the overall survival, but the present study was not designed and sufficiently powered to demonstrate this.
Neurosurgery, 1994
In a 31-year-old male patient suffering from progressive myelopathy, a right carotid angiography ... more In a 31-year-old male patient suffering from progressive myelopathy, a right carotid angiography disclosed an intracranial tentorial arteriovenous fistula (AVF) draining intrathecally into the spinal medullary veins. An embolization via the afferent meningohypophyseal artery was not technically feasible, and a microsurgical excision of the AVF was accomplished via a suboccipital approach, resulting in the angiographic cure of the fistula and progressive relief of the myelopathy. Fourteen reported cases of intracranial dural AVF draining intrathecally are reviewed. In most patients, authors encountered diagnostic difficulties similar to those noted in this case. Surgical and/or endovascular therapeutic methods have provided disappointing results, likely attributable to a prolonged course of spinal cord dysfunction. Pathophysiologically, a mechanism of venous congestion of the cord seems to be involved, as acknowledged by several magnetic resonance and angiographic studies. In patients who appear to have a clinical and myelographic picture of "vascular" myelopathy and who exhibit negative spinal angiography, a four-vessel cerebral angiography should be undertaken, aiming at the recognition of an intracranial AVF.
Journal of Neuro-Oncology, 2009
Meningiomas represent one of the largest subgroups of intracranial tumors. They are generally ben... more Meningiomas represent one of the largest subgroups of intracranial tumors. They are generally benign, but may show a histological progression to malignancy. Grades II and III meningiomas have been less well studied and are not well controlled because of their aggressive behaviour and recurrences. There is no consensus on therapeutic strategies and no prognostic factors are known. In order to determine these parameters, a multi-institutional retrospective analysis was performed in France with the support of the Neuro-Oncology Club of the French Neurosurgical Society. This study was performed on 199 adults treated for WHO grade II (166 patients) or grade III (33 patients) meningiomas between 1990 and 2004 in the Neurosurgery Departments of five French University Hospitals. Data on epidemiology, clinical behaviour and therapy were collected. Overall survival and progressionfree survival were analysed as a function of each possible prognostic factor. For patients with grade II meningiomas, the 5-and 10-year OS rates were 78.4 and 53.3%, respectively, while, for patients with grade III meningiomas, the corresponding values were 44.0 and 14.2%. For patients with grade II meningiomas, the 5-and 10-year PFS rates were 48.4 and 22.6%, respectively, the corresponding values for patients with grade III meningiomas being 8.4 and 0%. For the grade II meningiomas, univariate analysis showed that age \ 60 years (P \ 0.0001) and Simpson 1 resection (P = 0.055) were associated with a longer OS. For the grade III meningiomas, univariate analysis showed that age \ 60 years (P \ 0.0001) and RT (P = 0.036) were associated with a longer OS. Histological grade II was found to be associated with a longer PFS (P = 0.0032) and RT reduced the PFS in grade II meningiomas (P = 0.0006) There were no other prognostic factors in terms of PFS for grades II and III meningiomas in univariate analysis. Multivariate analysis confirmed that age (\ 60 years), Simpson 1 and histological grade II were independent prognostic factors for survival. This retrospective study might improve the management of grades II and III meningiomas. Prospective trials should delineate strong therapeutic guidelines for high-grade meningiomas.
Journal of Neuro-Oncology, 2010
The aim of our study was to evaluate the role of proton magnetic resonance (MR) spectroscopy and ... more The aim of our study was to evaluate the role of proton magnetic resonance (MR) spectroscopy and MR perfusion in the follow-up of low-grade gliomas, since conventional MR imaging (MRI) is not reliable in detecting the passage from a low-to high-grade tumor. Twenty-one patients with a World Health Organisation (WHO) grade II glioma were followed up using proton MR spectroscopy, perfusion, and conventional MRIs. Follow-up MRIs had been performed at the third month of evolution and then twice a year, with an average of five MR studies per patient. Five out of the 21 patients had an anaplastic transformation. A choline to creatine ratio (choline/creatine ratio) above 2.4 is associated with an 83% risk of a malignant transformation in an average delay of 15.4 months. The choline/creatine ratio at this threshold was more efficient than perfusion MR in detecting the anaplastic transformation, with sensitivity of 80% and specificity of 94%. An increased choline/creatine ratio seemed to occur an average 15 months before the elevation of relative cerebral blood volume (rCBV). The mean annual growth of low-grade glioma was 3.65 mm. A growth rate higher than 3 mm per year was also correlated with greater risk of anaplastic transformation. Proton magnetic resonance spectroscopy should be recommended in the follow-up of low-grade gliomas since the choline/creatine ratio can predict anaplastic transformation before perfusion abnormalities, with high positive predictive value of 83%.
Acta Neurochirurgica, 2009
Object This study was undertaken to analyze outcomes and to assess the prognostic impact of age, ... more Object This study was undertaken to analyze outcomes and to assess the prognostic impact of age, location, surgery, radiotherapy (RT), and histopathology in a series of adult infratentorial ependymomas. Methods This was a retrospective study of a population of 106 adult patients with infratentorial ependymomas diagnosed between 1990 and 2004. A central pathological review of all cases was performed. Grading was according to the WHO and Marseille's neograding classifications. Results The series consisted of 58 males (54.7%) and 48 females (45.3%) in the age range of 18-82 years. Using the WHO classification, 88 patients (83.0%) had grade II and 18 patients (17.0%) grade III ependymomas. Using the Marseille's neograding system, 91 patients were low-grade and 15 high-grade. Gross total resection was achieved in 66 patients (62.3%). Thirty-seven patients (35.0%) received adjuvant RT. The 5-and 10-year overall survival rates for the entire cohort were 86.1% and 80.5%, respectively. On multivariate analysis, a preoperative Karnofski performance status score>80, no recessus lateral extension and a low histological grade (Marseille's grading) were associated with a longer overall survival. The 5-and 10-year progression-free survival rates for the entire cohort were 70.8% and 57.7%, respectively. On multivariate analysis, no recessus lateral extension, gross total resection and a low Acta Neurochir (2009) 151:947-960 histological grade (Marseille's grading) were associated with a longer progression-free survival. Adjuvant RT was significantly associated with a better overall and progression-free survival in incompletely resected WHO grade II ependymomas. Conclusions This study highlights the key role of histology in the clinical outcome and the fact that gross total resection is a main prognostic factor and the treatment of choice for posterior fossa ependymomas. The use of adjuvant RT in patients with incompletely resected WHO grade II ependymomas appears beneficial, but its effect on high-grade tumors remains to be determined.
Neuro-Oncology, 2015
These authors (P.M. and P.M.) participated equally in this work.
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Papers by Jacques Guyotat