François Nataf

Intraspinal meningiomas: review of 54 cases with discussion of poor prognosis factors and modern therapeutic management.

INTRODUCTION Intraspinal meningiomas account for 25%-46% of primary spinal cord tumors. Technical advances in magnetic resonance imaging (MRI) and surgical procedures (ultrasonic cavitation aspirators [CUSA], lasers) have brought about better clinical results. In spite of these new techniques, a small percentage of patients still present with poor postoperative results and/or a recurrence. The authors tried to determine which data could influence clinical outcome and what therapeutic modalities could limit recurrence rate. MATERIALS AND METHODS We reviewed 54 patients who from 1963 to 1994, each had surgery for an intraspinal meningioma. There were 43 females and 11 males, aged 8 to 85 years old. Thirty-six (66.6%) patients were ambulatory on admission; only 2 presented with a paraplegia. Tumor location was cervical in 10 cases, thoracic in 43 cases, lumbar in 1 case. Forty-seven tumors were intradural, 5 epidural, 2 epidural and intradural. Thirty patients underwent a myelography, 10 a computed tomography (CT) scan, and 14 an MRI. Twenty-three spinal angiographies were performed before surgery. Complete removal was achieved in 50 patients (92.6%). Ultrasonic cavitation was used 10 times for debulking the tumor, and laser was used in 12 surgical procedures to perform hemostasis of the meningioma and to coagulate the dural attachment. RESULTS The majority of the neoplasms were meningothelial (N = 24) or psammomatous (N = 11). No mortality was noted. Morbidity concerned five patients: two pulmonary embolisms, one definitive paraplegia, one transient deficit, and one epidural suppuration, which necessitated a second operation. Mean follow-up was 28 months. Final functional results were very good in 85% and good in 13%; one patient (2%) worsened. Two recurrences were noted: one with clinical signs and the other with only CT-scan modifications. Both patients underwent complementary radiotherapy. DISCUSSION AND CONCLUSION The authors discuss factors influencing functional results. Sex, pregnancy, pathologic diagnosis, and recurrence do not seem to have any influence. Calcification of the meningioma, as well as an anterior dural attachment, are pejorative factors. They insist on preoperative angiography and point out the advantage of using a CUSA and/or a laser to debulk and coagulate the tumor itself and its dural attachment. They propose radiation therapy as an adjuvant treatment or an alternative to reoperation, which could be hazardous for some patients when, for instance, a recurrence is located in a critical area or when the patients general status is fragile.

Linac radiosurgery for cerebral arteriovenous malformations: results in 169 patients

PURPOSE To present the SALT group results using Linac radiosurgery (RS) for AVM in 169 evaluable patients treated from January 1990 thru December 1993. METHODS AND MATERIALS Median age was 33 years (range 6-68 years). Irradiation was the only treatment in 55% patients. Other treatment modalities had been used prior to RS in 45%: one or more embolizations in 36%, surgery in 6%, and embolization and surgery in 3% patients. Nidus were supratentorial in 94% patients, infratentorial in 6% patients. Circular 15 MV x-ray minibeams (6-20 mm) were delivered in coronal arcs by a GE-CGR Saturne 43 Linac. Patient set-up included a Betti arm-chair, a Talairach frame. Prescribed peripheral dose was 25 Gy on the 60%-70% isodose (max dose 100%). Arteriographic results were reassessed in December 1997 at 48 to 96 months follow-up. RESULTS The overall obliteration rate (OR) was 64% (108/169). AVM volumes ranged from 280 to 19,920 mm(3), median 2460 mm(3). OR was 70% for AVM </= 4200 mm(3) 4200 mm(3) (p 25 mm (p = 0.04). OR was 71%, in the absence of embolization, vs. 54% for previously embolized nidus (p = 0.03). OR was 71% for monocentric RS vs. 54% for multi-isocenters (p 28 Gy vs. 55% for values </= 28 Gy (p 79% vs. 57% for lower values (p 17 Gy, vs. 59% for mLd </= 16 Gy (p 40%, vs. 54% for mLi </= 40% (p 85% vs. 60% for CR </= 84% (NS). For patients treated according to our protocol, i.e., 24-26 Gy on the 60%-70% isodoses, OR was higher (68%) than for other patients (47%) (p = 0.02). After multivariate analysis, absence of previous embolization and mono isocentric-irradiation were independent factors predicting obliteration. Complications were: recurrent hemorrhage, 4 patients (1 patient died); brain necrosis on MRI, 2 patients; subsequent epilepsy, 4 patients; other subsequent neurologic deficits, 3 patients. CONCLUSION Overall OR was 64% (48-96 months follow-up). After monovariate analysis higher ORs were associated with smaller volumes </= 4200 mm(3), smaller nidus size </= 25 mm, absence of prior embolization, monoisocentric RS, higher values for mean and minimum lesion doses and compliance to our protocol. Higher values for the peripheral dose and isodose tended to give better results. Multivariate analysis showed that the absence of prior embolization and monoisocentric irradiation were independent factors predicting successful irradiation.

Comparison of deep wound infection rates using a synthetic dural substitute (neuro-patch) or pericranium graft for dural closure: a clinical review of 1 year.

OBJECTIVEThe need to repair dural defects has prompted the use of dura mater substitutes. Many synthetic materials have been used for dural closure. Neuro-Patch (B. Braun Médical S.A., Boulogne, France) is a nonabsorbable microporous fleece composed of polyester urethane that has been approved for human use by the European Union since 1995. To the best of our knowledge, no clinical series with Neuro-Patch have been published thus far, particularly with regard to septic complications. The aim of our study was to compare the safety of Neuro-Patch with that of pericranium graft with regard to postoperative wound infections. METHODSThis is a retrospective study of 1 year’s experience including all patients who underwent dural plasty with a Neuro-Patch (n = 61) or pericranium graft (n = 63). The follow-up period was at least 12 months after surgery. Before wound infection rates in the two groups were compared, factors suspected of being risks for neurosurgical site infection were evaluated. RESULTSPatient characteristics (mean age, neurological diagnosis), surgical procedures, prophylactic antibiotics, and risk factors for surgical infections (including duration of surgery, emergency, contaminated operations, and external cerebrospinal fluid drainage) were similar in the Neuro-Patch and pericranium groups. Deep wound infection rates in the Neuro-Patch and pericranium groups were 15 and 5%, respectively (P = 0.06), and cerebrospinal fluid leaks were significantly more frequent in the Neuro-Patch group (13 versus 1.6%, P < 0.05). CONCLUSIONThe results of our investigations show that Neuro-Patch raised the risk of wound infection, as do foreign materials implanted in the body. Synthetic dural grafts should be reserved for when autologous grafts are not sufficient or possible. An extensive prospective multicenter randomized trial is needed to confirm our results.

Does Aneurysmal Wall Enhancement on Vessel Wall MRI Help to Distinguish Stable From Unstable Intracranial Aneurysms

Background and Purpose— Arterial wall enhancement on vessel wall MRI was described in intracranial inflammatory arterial disease. We hypothesized that circumferential aneurysmal wall enhancement (CAWE) could be an indirect marker of aneurysmal wall inflammation and, therefore, would be more frequent in unstable (ruptured, symptomatic, or undergoing morphological modification) than in stable (incidental and nonevolving) intracranial aneurysms. Methods— We prospectively performed vessel wall MRI in patients with stable or unstable intracranial aneurysms. Two readers independently had to determine whether a CAWE was present. Results— We included 87 patients harboring 108 aneurysms. Interreader and intrareader agreement for CAWE was excellent (&kgr;=0.85; 95% confidence interval, 0.75–0.95 and &kgr;=0.90; 95% confidence interval, 0.83–0.98, respectively). A CAWE was significantly more frequently seen in unstable than in stable aneurysms (27/31, 87% versus 22/77, 28.5%, respectively; P<0.0001). Multivariate logistic regression, including CAWE, size, location, multiplicity of aneurysms, and daily aspirin intake, revealed that CAWE was the only independent factor associated with unstable status (odds ratio, 9.20; 95% confidence interval, 2.92–29.0; P=0.0002). Conclusions— CAWE was more frequently observed in unstable intracranial aneurysms and may be used as a surrogate of inflammatory activity in the aneurysmal wall.

Bleeding after radiosurgery for cerebral arteriovenous malformations.

OBJECTIVE:Obliteration is progressive after radiosurgery (RS) for cerebral arteriovenous malformation (AVM), and until it is complete, there is still a risk of hemorrhage. The aim of our study was to evaluate the severity of hemorrhage after RS, the actuarial risk of hemorrhage, and the parameters associated with hemorrhage. METHODS:Of 756 patients treated by linear accelerator RS for AVM, 51 (6.5%) had one or more hemorrhages after the RS. We studied the clinical, anatomic, and dosimetric parameters and obliteration rate before hemorrhage and then calculated the actuarial risk per patient and per hemorrhage before and after RS. Correlations between parameters and risk were studied by univariate and multivariate analysis using Kaplan-Meier hemorrhage-free survival curves and the Cox model. RESULTS:Apart from one exclusively ventricular hemorrhage, which caused the death of the patient, only parenchymal hemorrhages were associated with morbidity and neurological deficits (64.5% of all cases of hemorrhage had neurological deficits, 45% had a permanent deficit). The overall mortality rate per hemorrhage was 7.14%. The overall morbidity rate was 47.6%, 26.2% with a permanent deficit. In all but one patient, the AVM was not cured before hemorrhage; thus, the mean obliteration rate before hemorrhage was 24%. The actuarial hemorrhage rates were 3.08% per year per patient and 3.31% per year per hemorrhage. The actuarial rate per patient increased from 1.66% the 1st year to 3.87% in the 5th year after RS but was not statistically different from the rate before radiosurgery. The parameters found to be correlated with hemorrhage risk after RS using multivariate analysis were intranidal or paranidal aneurysms, complete coverage, and minimum dose. CONCLUSION:The risk of hemorrhage after RS would seem to be the sum of hemorrhage risk factors of the AVM and factors predicting a poor level of obliteration. These factors can be predicted in some cases but rarely avoided.

Radiosurgery With or Without A 2-mm Margin for 93 Single Brain Metastases

PURPOSE Retrospective comparison of Linac radiosurgery (RS) in 93 single brain metastases with or without a 2-mm margin. PATIENTS AND METHODS A total of 153 patients had Linac RS (between April 1992 and June 2004), with 139 patients (90.8%) evaluable in June 2005. Sixty-one patients (44%) had extracranial lesions and 65 patients had neurologic symptoms (47%). RS alone: 105 patients (66%); RS +whole brain radiotherapy: 34 patients (24%). Single metastasis: 93/139 patients; classic RS: 42/93 patients; 2-mm margin: 51/93 patients; 30 multiple lesions patients were excluded. TREATMENT 15 Mv X-ray Linac, circular minibeams, 8-30 mm, four to six noncoplanar coronal arcs. Isodose was 60-80%; doses were 10-20 Gy. FOLLOW-UP 12 months-13 years; median, 14 months. RESULTS Local control (LC) was not improved in 51 margin patients vs. 42 classic RS patients: 1 year: 69.1% and 72.4%. Two-year LC rate: 64% and 54.7%, respectively. Survival: median classic RS: 11.3 months; margin RS, 19 months (p = 0.34) and 1 year, 41.6% and 60.2%, respectively. Margin RS patients had a significantly higher rate of severe parenchymal complications: 19.6% vs. 7.1% (p = 0.02); surgery was necessary in 4 of 51 cases vs. 1 of 42 classic RS cases. CONCLUSION No increase of 1- and 2-year LC rate in margin RS or survival and median survival: 11.3 vs. 19 months (NS) 2-mm margin associated with more severe parenchymal complications (p = 0.02). This procedure is therefore not recommended. Late CT images and 1-mm margin as recommended by pathologists, use of three-dimensional magnetic resonance imaging and fuzzy method to calculate volumes may yield better results. Stereotactic hypofractionation requires further studies.

Three-dimensional dynamic time-resolved contrast-enhanced MRA using parallel imaging and a variable rate k-space sampling strategy in intracranial arteriovenous malformations

To evaluate the effectiveness of three‐dimensional (3D) dynamic time‐resolved contrast‐enhanced MRA (TR‐CE‐MRA) using a combination of a parallel imaging technique (ASSET: array spatial sensitivity encoding technique) and a time‐resolved method (TRICKS: time‐resolved imaging of contrast kinetics) and to compare it with 3D dynamic TR‐CE‐MRA using ASSET alone in the assessment of intracranial arteriovenous malformations (AVMs).

Microsurgery or radiosurgery for cerebral arteriovenous malformations? A study of two paired series.

OBJECTIVE To detect parameters that may augment the therapeutic strategy in patients with a cerebral arteriovenous malformation (AVM) that is considered equally suitable for treatment by neurosurgery or radiosurgery, we compared the efficacy and risks of these two methods in a paired series with similar patient and AVM characteristics. PATIENTS AND METHODS Two series of patients with AVM were studied, including a series of 39 patients treated using microsurgery (MS) and another series of 39 patients treated via radiosurgery (RS). These series were paired for age and sex, initial symptoms, size, location and Spetzler-Martin grade, and presence of embolization preceding treatment. We compared the posttreatment outcome in the two groups with respect to obliteration rate, neurological status, mortality rate, and recurrent bleeding. Statistical analysis was performed using paired Students t test. RESULTS The Glasgow Outcome Scale values and Modified Rankin Scores measured at discharge and 12 to 24 months were significantly better in the RS series than in the MS series. The obliteration rate tended to be higher in the MS series (91% versus 81%; P = 0.10, not significant), whereas the rate of neurological deficit was higher in the MS series than in the RS series(P < 0.001). The mortality rate was not significantly different in the two series, but the rate of recurrent bleeding was higher in the RS group (10% versus 0%; P = 0.04). CONCLUSIONS Although the rate of cure was similar for patients treated with MS and RS, neurological morbidity was higher after MS and recurrent bleeding was more frequent after RS.

REPEAT LINEAR ACCELERATOR RADIOSURGERY FOR CEREBRAL ARTERIOVENOUS MALFORMATIONS

PURPOSE To evaluate repeat radiosurgery (RS2) for cerebral arteriovenous malformations (AVMs) after failure of initial radiosurgery (RS1). METHODS AND MATERIALS Between 1986 and 2000, 41 patients underwent RS2. Nine patients were not assessable: seven had insufficient follow-up (RS2 in 1999 and 2000) and two had no recent control angiography data. Thus, 32 (78%) of 41 patients were assessed. Most lesions (29 [90%] of 32) were supratentorial: 22 (69%) on the left, 8 (25%) on the right, and 2 on the midline (6%). The patients had Spetzler-Martin Grade 1-5 (median Grade 3). The symptoms before RS1 included hemorrhage in 20 (63%), epilepsy in 10 (31%), progressive neurologic deficits in 2 (6%), and headaches in 6 (19%). Five patients had two or more symptoms. Twenty-two patients (69%) had received other treatment before RS1, including neurosurgery in 3 patients (9%) and one to six embolizations in 19 patients. At RS1, the median largest nidus dimension was 2.7 cm (range 0.8-5). The median volume was 2.7 cm(3) (range 1.2-9.9). The median time from RS1 to RS2 was 52 months (range 12-126). Between RS1 and RS2, 7 (22%) of 32 patients experienced bleeding. The same irradiation technique was used for RS1 and RS2, except for 2 patients who underwent RS2 at another institution. Circular 15-MV X-ray minibeams (range 6-20 mm) and coronal arcs were used. RS1 was monoisocentric in 75% of cases and multiisocentric in 25%. At RS2, the median largest nidus dimension was 3 cm (range 1.4-5). The median volume was 4.2 cm(3) (range 0.8-13.4). RS2 was monocentric in 72% of cases and multiisocentric in 28%. After RS2, the median follow-up was 19.5 months (range 0-79; mean 25.3). RESULTS After RS2, the obliteration rate was 59.3% (19 of 32). The median time to arteriographic obliteration was 21 months (range 12-96). The survival rate was 97% (31 of 32). Five of the 13 patients with a nonobliterated nidus experienced complications; 3 had bleeding (9%) and 2 without prior neurologic deficits developed partially regressive neurologic deficits. One patient with a previously existing deficit developed an additional new partially regressive neurologic deficit after an episode of bleeding. Thus, 3 (9%) of 32 patients had neurologic complications. Moderate-grade parenchymal changes at MRI increased after RS2 (88.2% vs. 57.7% after RS1; p = 0.10, not significant). However, necrosis-like changes did not significantly increase. After RS1 failure, salvage may be attempted by embolization, neurosurgery, or RS2. RS2 should be considered after the second successive annual angiogram if reduction of the nidus is <25%. CONCLUSION The results after RS2 are encouraging. A multidisciplinary approach is mandatory to reduce the initial failure rate and to choose the modality and timing of salvage treatment.

Classification des oligodendrogliomes de l’hôpital sainte-anne: Mise au point à l’usage des études retrospectives

Resume Objectif La constitution de groupes homogenes de patients est indispensable pour que les resultats therapeutiques des oligodendrogliomes puissent etre valablement apprecies et compares d’une institution a l’autre. Des discordances croissantes sont cependant observees dans le diagnostic histologique des oligodendrogliomes ou oligo-astrocytomes. La presente etude a eu pour objectif principal d’apprecier si, pour les etudes retrospectives, l’IRM peut servir de base commune et de « trait d’union » entre les diagnostics etablis selon la classification de l’Organisation Mondiale de la Sante (OMS) ou selon celle l’hopital Sainte-Anne (classification SA). Materiel et methodes Cette etude a porte sur une serie de 251 patients adultes porteurs d’un oligodendrogliome ou oligo-astrocytome de grade A ou B selon SA et qui ont ete pris en charge dans notre Hopital durant la periode 1984-2003. Les preparations histologiques de routine et l’IRM ou le scanner preoperatoires effectues apres injection de produit de contraste ont ete simultanement revus afin d’apprecier l’influence sur la survie des parametres suivants : presence ou absence d’une composante astrocytaire polymorphe ou gemistocytique, de necrose, d’une prise de contraste (PC) ; hyperplasie endotheliale : absente, discrete (HE+), ou conforme au seuil defini selon le grading SA (HE++). Les tumeurs ont ete classees en grade A : absence de PC et d’HE, en grade B : PC et/ou HE++, ou en grade « A/B » : HE+, absence de PC. Resultats 70,1 % des tumeurs ont ete classees en « oligodendrogliome pur », 19,5 % en « oligo-astrocytome polymorphe », et 10,3 % en « oligo-astrocytome gemistocytique ». Dans les tumeurs de grade A, A/B ou B, la presence d’une composante astrocytaire polymorphe ou gemistocytique n’avait pas d’influence significative sur la survie, mais respectivement 53 % et 65 % de ces tumeurs versus 32 % des oligodendrogliomes « purs » etaient de grade B lors du diagnostic. Dans ces trois sous-types histologiques, la survie n’etait egalement pas significativement differente selon que l’hyperplasie endotheliale etait absente ou discrete (HE+). Apres regroupement des sous-types histologiques, d’une part, et des tumeurs avec HE+ ou absente, la serie etait composee de 153 oligodendrogliomes de grade A et de 98 oligodendrogliomes de grade B ; la survie correspondante etait de 142 mois versus 52 mois (p Conclusions Sur la base de ces resultats et ceux de nos etudes precedentes montrant que, parmi les formes communes de gliomes classees selon SA, seuls les oligodendrogliomes ou oligo-astrocytomes peuvent ne pas prendre le contraste, nous proposons que, pour les etudes cliniques retrospectives : 1) les oligodendrogliomes et les oligodendrogliomes selon la classification SA soient regroupes en une categorie unique, 2) les gliomes sans PC, quels que soient leur type histologique et leur grade de malignite selon l’OMS, soient regroupes avec les oligodendrogliomes A selon la classification SA, 3) en ce qui concerne les gliomes avec PC : les tumeurs classees, selon l’OMS, en oligodendrogliomes ou oligo-astrocytomes de grade II ou III ainsi que les glioblastomes secondaires ou avec composante oligodendrogliale soient regroupees avec les oligodendrogliomes de grade B selon la classification SA. Cependant, les tumeurs qui presentent une PC en anneau et un œdeme « en doigt de gant » doivent etre exclus ou analyses separement.