[Adult supratentorial oligodendrogliomas. Surgical treatment: indications and techniques]. / Oligodendrogliomes supratentoriels de l'adulte. Traitement chirurgical: indications et techniques.

Surgical resection is the first step in the treatment of adult supratentorial oligodendrogliomas (OLG). However, the role of resection on prognosis, the most appropriate time for surgery along the natural history of those tumors, and the best operative strategy remain debated. Survival curves after resection vary greatly among reported series, in particular as a result of a persisting confusion in identification and classification of cerebral OLG. Surgical or stereotactic biopsy is the first surgical procedure which enables confirmation of the diagnosis suggested on imaging, assessment of extension of tumor cell infiltration beyond abnormalities limit described an imaging, and currently available molecular biology studies. Biopsies may be the only surgical procedure in patients having a deep-seated tumor with minimal mass effect, or prior to a surgical resection or a "wait and watch" strategy. Surgical resection is indicated for the other patients. However, it has not been demonstrated that time for resection has an influence on survival, excepted in patients with rapidly growing tumors, with mass effect causing increased intracranial pressure. A wait and watch strategy is therefore warranted in patients with a tumor aspect suggestive of a grade A OLG; surgical resection may be indicated later. There is a current trend for maximal safe resection, preserving functional cerebral areas, since truly complete resection of the tumor including infiltration is exceptional. However, from the contradictory results reported to date, one cannot ascertain whether large or complete resection based on imaging is associated with significantly longer survival. Neuronavigation guidance, intraoperative imaging, and cortical stimulation techniques are helpful neurosurgical techniques enabling maximal safe resection with preservation of functional areas.

[Results of the Sainte-Anne - Lyons series of 318 oligodendroglioma in adults]. / Résultats de la série Sainte-Anne - Lyon de 318 oligodendrogliomes intracrâniens de l'adulte.

INTRODUCTION: Incidence of cerebral oligodendrogliomas is increasing because of better recognition made possible by improved classifications. We studied a homogeneous series using the Sainte-Anne grading scale in order to better understanding the history of these tumors with or without treatment and to assess prognosis and associated factors. PATIENTS AND METHODS: A retrospective series of 318 adult patients with oligodendroglioma (OLG) treated at Hôpital Sainte-Anne, Paris (SA) and Hôpital Neurologique, Lyons (L) between 1984 and 2003 was analyzed: 182 grade A OLG (SA + L), 136 grade B among which a homogenous series of 98 (SA) were included. For grade A: age at diagnosis ranged from 21 to 70 (mean: 41), sex ratio was 1.28. For grade B: age at diagnosis ranged from 12 to 75 (mean: 45.5), sex-ratio was 1.58. The main first symptoms were: epilepsy (A: 91.5%; B: 76%), intracranial hypertension (A: 7.9%; B: 14.6%), neurological deficit (A: 5.1%; B: 17.7%). The most frequent locations were: frontal, insular and central for both A and B. Mean size was 55 mm for grade A, 62 mm for B. Calcifications were found in 20% of A, 48.5% of B. No tumor was enhanced on imaging (CT/MRI) in grade A, all but 7 in grade B. All patients underwent surgery either for biopsy (A: 47.2%; B: 53%), or removal which was partial (A: 26.4% vs B: 19.4%) or extended (A: 36.3% vs B: 37.8%). Fifty-six patients underwent 2 procedures and 12 three procedures. Radiotherapy was performed in 76.9% of grade A, and 91% of B patients, in the immediate postoperative period for 71% A and 82.7% B. Chemotherapy was delivered for 36% of grade A (in the event of transformation to grade B or failure of radiotherapy) and 67.5% of B patients. Among grade A tumors, 38% transformed into grade B within a mean delay of 51 months with a mean follow-up of 78 months. RESULTS: Median survival was 136 months for grade A and 52 for grade B. Survival at 5, 10 and 15 was 75.5%, 51% and 22.4% for grade A vs 45.2%, 31.3% and 0% for grade B respectively. In univariate and multivariate analysis, grade A survival was associated with age at diagnosis, tumor size, large removal and response to radiotherapy. Grade B survival was associated with age at diagnosis, wide removal and sharply defined limits of the tumor on imaging. CONCLUSIONS: Analysis of both published data and this series underlines many prognostic parameters. It shows that OLG are heterogeneous tumors even in each grade (A and B). Treatment should consequently progress towards more targeted procedures for patients mainly with postoperative radiotherapy and chemotherapy.

Dose-dense regimen of temozolomide given every other week in patients with primary central nervous system tumors.

BACKGROUND: Temozolomide has shown activity and limited toxicity in patients with primary brain tumors at doses of 150-200 mg/m(2)/day on days 1-5 every 4 weeks. In this study, a new alternative dose-dense regimen of temozolomide was explored in patients with recurrent brain tumors. PATIENTS AND METHODS: In this study, we evaluated the safety, dose-limiting toxicity, maximum tolerated dose, recommended dose and activity of temozolomide given on days 1-3 and 14-16 every 28 days (one cycle). The starting daily dose was 200 mg/m(2) in a group of at least six patients, with subsequent increments of 50 mg/m(2) in groups of at least 12 patients until unacceptable toxicity was reached. Oral ondansetron (8 mg) was given 1 h prior to temozolomide administration. McDonald's criteria were used to evaluate antitumor activity. RESULTS: Seventy patients with brain tumors entered this study. The median number of prior chemotherapy treatments was two (range 1-3). Patients were assigned to one of four groups to receive temozolomide at daily doses of 200 (seven patients), 250 (13 patients), 300 (38 patients) and 350 mg/m(2)/day (12 patients). The absence of dose-limiting toxicity at cycle 1 led us to establish dose recommendations based on toxicity after repeated cycles. A total of 23, 72, 192 and 83 cycles were given at daily doses of 200, 250, 300 and 350 mg/m(2), respectively. Grade 3-4 thrombocytopenia was observed in 0/7, 1/13, 5/38 and 4/12 patients treated at doses of 200, 250, 300 and 350 mg/m(2)/day, respectively. Grade 3-4 neutropenia was observed in 1/7, 0/13, 3/38 and 4/12 patients treated with 200, 250, 300 and 350 mg/m(2)/day temozolomide, respectively. At a dose of 350 mg/m(2), sustained grade 2-3 thrombocytopenia did not allow treatment to be resumed at day 14 in >40% of patients, and this dose was considered to be the maximum tolerated dose. Thus, a dose of 300 mg/m(2)/day that was associated with <20% treatment delay due to sustained hematological toxicity was considered as the recommended dose. Objective responses were reported in 13 patients. CONCLUSIONS: Temozolomide can be given safely using a dose-dense regimen of 300 mg/m(2)/day for 3 consecutive days every 2 weeks in patients with recurrent brain tumors.

[Preoperative devascularization of a vertebral metastasis with a spinal artery at the same level]. / Dévascularisation préopératoire d'une métastase vertébrale avec artère médullaire naissant au même étage.

An hypervascular and lytic thoracic (Th10) vertebral metastasis from kidney neoplasm causing cord compression was successfully resected after embolization. Because the anterior spinal artery arose at the same level, arterial embolization was only partial and completed by percutaneous vertebroplasty using Nbutyl cyanoacrylate.

High-power diode laser in neurosurgery: clinical experience in 30 cases.

BACKGROUND: High-power semiconductor diode lasers were recently introduced and have been tested in ophthalmology and general surgery. These lasers are attractive from the practical and economical standpoint, and have enough power to perform most surgical procedures. They could replace other surgical lasers such as CO2, argon, 1.06 microm, and 1.32 microm Nd-YAG lasers for many applications in neurosurgery. We report our initial experience with the first available 0.805-microm surgical diode laser, the Diomed 25 (Diomed, Ltd, Cambridge, U.K.) in a series of 30 patients. METHODS: The diode laser was evaluated during surgical resection of various types of central nervous system tumors in 30 patients. It was used free-hand in 27 patients in contact and non-contact, continuous wave (cw) and pulsed modes, and during ventricular endoscopy in three patients. Average time of laser use during a procedure was 248 seconds. Output power ranged from 1 to 25 watts, with an average power per patient of 2.64 to 15.5 watts (mean, 8.78 watts). Total energy delivered ranged from 65 to 11,051 joules per patient. RESULTS: Using 600- or 400-microm non-contact optic fiber, well pigmented tumor tissue hemostasis was obtained at cw 3 to 10 watts with a defocused beam, whereas vaporization required 10-25 cw or pulsed watts with a focused beam. Soft and tough tissue section could be obtained using a sculpted cone-shaped (600-300 microm tip) contact fiber at 7-10 cw watts after fiber tip charring. Because of the deeper penetration of 0.805-microm light in non-pigmented tissues, non-contact mode is not recommended for white matter or poorly vascularized tumors. The contact mode was not efficient on very soft tissues such as edematous brain parenchyma. The contact fibers proved to be very fragile because of heat generation. CONCLUSIONS: The high power diode laser proved to be efficient for hemostasis, section and vaporization, using contact and non-contact modes, at different output powers. Economical and ergonomical advantages of this new generation of surgical lasers may cause them to replace other surgical lasers such as argon, CO2, and Nd-YAG lasers, mostly for tumor surgery.

[The Codman Medos programmable shunt valve. Evaluation of 53 implantations in 50 patients]. / La valve de dérivation Codman Medos programmable. Bilan de 53 implantations chez 50 patients.

Fifty three Codman Medos programmable valves were implanted in 50 patients (28 men and 22 women) aged 5 to 77 years, from April 1992 to February 1994. They presented with a hydrocephalus 43 times, an arachnoid cyst three times and a CSF leakage four times. The aims of this study were: a) to test the reliability of this equipment, in current use as well as its eventual advantages, inconveniences and restraints, b) to determine its best indications. Follow-up ranged from 12 to 36 months (average = 22 months). Five patients were lost for follow-up. One patient died from a post-operative sepsis. Four died from their disease. Infectious complications concerned 6 patients (11%). A radio-clinical overdrainage syndrome appeared in 9 patients with slit-ventricles, 5 of them associated with sub-dural collections. All these cases were treated with shunt reprogrammings. While 43 pressure settings over 53 were satisfactory in the immediate post-operative period, it appeared that only 38% of shunts had required one only setting when the study period was over. A certain number of pressure adjustments malfunctioned: 6 times, post-operative X-ray controls showed pressures significantly different from the figures which had been selected (difference from -30 mm H2O to + 70 mm H2O); pressure readjustments were effective and accurate for five of them, but one shunt had to be changed; 15 deprogrammings were detected during long term follow-up, 9 of them after MR1. Pressure programming was readjusted only on patients presenting with clinical signs, i-e mainly for those having a pressure difference > +/-30 mm H2O. As a conclusion, the authors consider that such a shunt can be very useful in some precise indications as: NPH, multioperated hydrocephalus, arachnoid and porencephalic cysts, some spontaneous or iatrogenic CSF leakages, temporary shunts necessitating a progressive withdrawal. Because of a) the cost of this equipment, b) the specific restraints (X-rays controls, programmer), and c) the specific incidents (spontaneous and/or post-MR1 deprogramming), it seems difficult to generalize indications to all cases of hydrocephalus. On the other hand, these shunts have the great advantage of simplifying the treatment of overdrainage by avoiding, in all cases, a reoperation for changing the shunt and/or removing a subdural hematoma. Consequent economies due to a significant diminution of the duration of hospitalisation, could justify an enlargement of indications.

[Development of reconstruction techniques of the anterior skull base after tumor excision]. / Evolution des techniques de reconstruction de la base antérieure du crâne après exérèse tumorale.

183 benign and malignant tumors of the anterior cranial base were operated in the department of neurosurgery at Ste Anne's hospital, from June 1982 to December 1993. The bone defect was repaired first with bone sheets taken from the inner table of the cranial flap. Then allografts of irradiated bone and madreporic coral blocks were used as reconstruction material. Since January 1992, no bone reconstruction was performed; the anterior base was just covered with a sheet of Vicryl Composit Mesh (VCM) which was secured bilateraly on the pterion, the temporalis pars squamosa and around the ethmoid defect. This sheet of VCM reinforces the dural plane, which is always lined with a pediculated galea flap. These technical changes and evolution were motivated by: i/- a desire to simplify the surgical technique: ii/- the risk of transmission of viral diseases such as Creutzfeld Jacob disease by allografts, iii/- the frequency of splits and/or falls of madreporic coral grafts. Whatever the material, the infection risks were identical: 8% of subcutaneous and/or deep suppurations, 5% of post-operative meningitis. One patient presented with a transient clinical rhinorrhea.

[Role of radiotherapy in the treatment of meningioma]. / Place de la radiothérapie dans le traitement des méningiomes.

Between 1962 and 1986, 32 patients with intracranial meningiomas were referred to the Institut Gustave-Roussy for external radiotherapy either after incomplete surgery, or unfavorable histology (meningiosarcoma/anaplastic meningioma), or after recurrences. In the latter case, the mean time interval between the first surgery and the recurrence was 2 years (range: 1-6 years). Radiotherapy was performed using photons, electrons or mixed photons-electrons. The mean total dose was 48 Gy (range: 9-65 Gy) delivered in a mean time of 35 days with a 19 mean number of fractions. Radiotherapy was interrupted in three cases at 9 Gy-17 Gy-20 Gy because of neurological worsening. The actuarial 5-year survival was 64%. Among the 32 patients, 11 died, eight of tumoral progression or recurrence and three of other causes (one ovarian carcinoma, two unknown). Among the 21 alive patients, eight presented a recurrence; five of them could be reoperated on with two complete resections. None of the following factors were found to be of prognostic value on the survival nor on the recurrence occurrence: age, tumor location, first surgical resection type, and, in the group of patients treated at the time of recurrence, the quality of the surgery at the time of recurrence and the time interval between the first surgery and the recurrence. Only one factor was evidenced as of significant value on the recurrence as well as the 10-year survival: the total dose of irradiation with a 10-year survival rate of 74% for total doses higher than or equal to 47 Gy versus 14% when the total dose was lower than 47 Gy.

[Multiple cavernoma of delayed appearance]. / Cavernomes multiples d'apparition différée.

The authors report on a right fronto-singular cavernous angioma which appeared, in a 46 year-old woman, four years after the excision of a right rolandic localization. Diagnosis suggested on radiological findings was confirmed by histological examination. After a review of the literature the authors discuss possible mechanisms of such delayed appearance of intra-cerebral cavernous angiomas. They suggest the possibility of infraradiologic stage corresponding to a micro-malformation characterized by abnormal capillaries, which has not been yet histologically modified by hemorrhages, thrombosis, fibrosis, gliosis and calcifications.

Pilot study of 6 weeks of chemoradiotherapy with 5 FU and hydroxyurea in malignant gliomas.

In an attempt to improve the primary treatment of malignant gliomas we used a concomitant 6-week course of chemoradiotherapy with 5 fluorouracil (5 FU) and hydroxyurea (HU) in 24 adults with anaplastic astrocytoma (AA) (7 cases) or glioblastomas (GLB) (17 cases). This patient population was characterised by a poor prognostic profile; 50% of cases had biopsic or subtotal surgery and 70% had GLB. Patients received 2 Gy/day 18 MV photons with 300 mg/m2 of 5 FU in continuous infusion and 500 mg x 4/day per os of HU, five days per week during 6 weeks. Treatment was poorly tolerated in terms of toxicity and implied heavy logistics (hospitalization, central venous access) worsening the quality of life which is already bad in malignant gliomas. Unfortunately we did not improve median survival which does not exceed 26 weeks with 7 long survivors (> 49 weeks). This pilot study does not offer any benefits over current standard approaches. Aggressive locoregional approaches such as this should perhaps be attempted in patients with a better profile.

[YAG laser in neurosurgery]. / Les lasers YAG en neurochirurgie.

The authors try to answer to some practical questions concerning Yag Lasers in neurosurgery. The aim of this work is to determine the main data useful for the choice of a YAG-Laser. Are considered: the wavelengths which can be bought on the international market (1.06 microns or 1.32 microns for instance), the peripherics at disposal, the tissular effects due to the different lasers, the surgical applications and indications. The Laser unit which will be chosen should be a compromise between the different advantages and inconveniences of a particular laser, its tissular effects, its price. The multi-wavelengths units appear to be, at the present time, interesting compromises (such as 1.32 + 1.06 microns, CO2 + 1.06 microns).

[Combined CO2 and Nd-YAG laser in neurosurgical practice. A 1st experience apropos of 40 intracranial procedures]. / Le laser combiné (CO2 + Nd-YAG 1.06 microns) en pratique neurochirurgicale. Première expérience à propos de 40 interventions intra-crâniennes.

The authors present their experience concerning the use of Combolaser (Lasermatic, Finland), in neurosurgery. This laser-unit combines two wavelengths (CO2 and 1.06 Nd-YAG) which are emitted simultaneously and coaxially. During the last 12 months, 40 patients harbouring an intracranial tumor were operated upon with such a combolaser unit: 8 infra-tentorial, 32 supra-tentorial, 17 were meningiomas. The mean output power used during the procedures was 3-5 w for both CO2 and Nd-YAG beams. The authors discuss the advantages and inconveniences of such a laser; and they compare it with the other laser-units they have been using for the last 10 years: CO2-Laser, 1.06 Nd-YAG and 1.32 Nd-YAG laser. The main inconvenience of this unit is linked to the utilization of the articulated arm which conducts the CO2 laser beam. This drawback should be avoided or limited by the use of a fiber microguide, which will conduct both CO2 and Nd-YAG beams simultaneously. The principal contribution of a combined-laser unit is the quality of the haemostasis associated to a very good vaporization and cutting effect. When both wavelengths are synchronized, the combined laser beams penetrate into the nervous parenchyma more deeply than the only CO2 laser beam would with the same parameters. The vaporization effect is identical to that obtained with the isolated CO2 laser; the quality of haemostasis is limited to the effects of the Nd-YAG laser. Another advantage must be emphasized: the possibility of utilizing separately the CO2 laser and the 1.06 Nd-YAG.

[Stereotaxic laser interstitial thermotherapy. A new alternative in the therapeutic management of some brain tumors]. / La thermothérapie interstitielle laser stéréotaxique. Une nouvelle alternative dans la prise en charge thérapeutique de certaines tumeurs cérébrales.

Laser Interstitial Thermo Therapy (ITT) is a new procedure which has been performed only a few times in our department as well as in foreign services. The aim of an ITT is to increase the temperature of a tumoral target which has been perfectly determined stereotactically. In the center of the target, i-e at the extremity of the laser fibre, temperature reaches 80 degrees 90 degrees C and creates a coagulation necrosis. At the periphery of the target, temperature must be 41 degrees-43 degrees C so as to create a selective lesion of the pathological tissue due to proteinic and enzymatic denaturation. The authors present their experience based on 8 patients who underwent an ITT between June 1990 and October 1991. A stereotactic determination of the tumor is first performed; then two routes are determined for the laser-fibre (Nd-YAG 1.06 microns, fiber diameter: 400 mu) and for the thermic electrode. The ITT itself is performed a few days later (P = 3-5w, time: 800-1200 seconds). Laser heat effects are monitored with MRI controls (H5, H24, D8 then monthly). The authors insist on the importance of a long follow-up so as to be sure of the complete inocuity of such a treatment. It is the only way to broaden and develop laser-ITT procedures as therapeutic alternatives for certain deep-seated intracerebral tumors.

[Terson's syndrome and intraocular complications in meningeal hemorrhages (26 cases)]. / Syndrome de Terson et complications intra-oculaires dans les hémorragies méningées (26 cas).

The Terson syndrome was described in the early 1900's as the association of an intra-vitreous humor bleeding and a subarachnoidal hemorrhage (SAH). The high jeopardy of blindness of such a syndrome emphasizes the importance of evaluating as soon as possible the presence of blood in the posterior chamber of patients presenting with a SAH. 250 patients admitted in the Neurosurgical Department of Ste Anne Hospital with a SAH were evaluated between January 1984 and February 1990. 26 had an intra-ocular hemorrhage (10.5%). In those cases the mortality rate was not increased (15.4%) but the morbidity rate was higher (42%). Concerning the intra-ocular bleeding, 4 patients underwent a vitrectomy (2 had a complementary photocoagulation). Only one patient had a visual sequela (partial decrease of visual acuity). These data emphasize the visual risk which has to be considered; a specific treatment (vitrectomy and/or photocoagulation) must be performed as quickly as possible so as to save the vision. In some particular instances, the ophthalmological treatment might even be necessary before the intracranial procedure itself.

1.32 microns Nd:YAG laser during neurosurgical procedures experience with about 70 patients operated on with the MC 2100 unit.

The authors present their clinical experience with 1.32 microns Nd-YAG Laser. After a series of experimental studies which demonstrated the adaptability of such a wavelength to central nervous surgery, they used such a Laser during current neurosurgical procedures. The MC 2100 unit combines two wavelengths 1.32 microns and 1.06 microns, and two emission modes: continuous wave (c.w.) and pulsed. This Laser has been used during 70 procedures: 54 supra-tentorial, 8 infra-tentorial, 5 intra-spinal, 3 intra-orbital, 600 microns and 400 microns fibers were preferred in most cases, either with a telescopic light handpiece or- less often--with a focussing handpiece. The quality of vaporization--close to that of CO2 Laser- and of haemostasis-close to that of 1.06 microns Nd-YAG Laser-makes this 1.32 microns wavelength very suitable for neurosurgery. The manoeuverability due to the optic fibers is most interesting. Furthermore, such a Laser should have in the near future large applications in stereotactic and/or endoscopic neurosurgery.

[Spontaneous dissection of the exocranial internal carotid artery. Therapeutic aspects]. / Dissection spontanée de la carotide interne exocrânienne. Aspects thérapeutiques.

Spontaneous dissection of the extracranial internal carotid artery is uncommon and has been first described in 1959. Since then, 250 cases have been published. The authors report on 5 recent cases and on that occasion, they review the literature and discuss the different therapeutic possibilities. This pathology can be envisaged when a middle-aged adult, free of any previous pathology or trauma, presents with latero-cervical pain followed by cerebral ischemic stroke. The angiographic findings are of three types: regular or irregular extensive stenosis, pseudo-aneurysmal dilatation followed by luminal stenosis, funnel-like tapering of the vessel. The spontaneous course of such a dissection most often (80%) leads to an almost complete resolution of clinical and angiographic signs. Treatment, therefore, should essentially be based on anticoagulant and antiaggregant therapy, so as to prevent ischemic attacks or carotid thrombosis. Surgical indications should remain exceptional.

[Management of cranial-injured patients in the era of the Emergency Medical Service and the scanner. Comparative epidemiologic study with a 12-year interval in the same department of neurosurgery, in the Paris region]. / La prise en charge des traumatisés du crâne à l'ère du SAMU et du scanner. Etude épidémiologique comparée à 12 ans d'intervalle dans un même service de neuro-chirurgie, en région parisienne.

The authors present an analysis of the different data concerning the emergencies admitted in the Neurosurgical department of Sainte-Anne Hospital in Paris, during the one year-period extending from 1st June 1983 to 1st June 1984. These data have been compared to the corresponding findings established during 1972 in the same department. Traumatology appears to be a more and more limited activity among neurosurgical emergencies: 55% of admissions in 1972, 43% in 1983-84. The main characteristics of injured patients on admission have not changed: 65% are in a coma, 1.25 are operated in emergency, age distribution and types of lesion are identical. The sorting of the patients has improved: 25% of them were operated upon in 1972, 37% in 1983-84. Conveyance of injured patients has undoubtedly improved in quality during the last years; yet the duration of transport is still important, too important, even in Paris: 2 h 30 as an average-time. Another favorable factor has been the coming out of CT-Scan; it is of course of great help for diagnosis, but it must not let forget basic and fundamental therapeutic decisions.

[Real-time ultrasonography in neurosurgery. Puncture of an intracranial hypoechogenic cavity]. / Ultra-sonographie en temps réel en neurochirurgie. Ponction d'une cavité hypo-échogène intracrânienne.

The authors have been using real time echography in neurosurgical procedures since 1981: either for detection of a small sub-cortical tumor during a surgical operation, either for biopsy-guidance, or for puncturing a cavity (abscess, cyst or hematoma). The imaging is performed with a CGR SONEL 100 apparatus and two different frequency transducer elements: 3.5 MHz and 5 MHz. 56 patients underwent this technique; 22 times the lesion was hypoechoic: abscess give homogeneous, round hypoechoic image, often surrounded by a fine hyperechoic line; intracerebral hematoma produces an hypoechoic image after a 10 to 15 days evolution: compared to an abscess it then has a more hyperechoic irregular wave-like limit; tumoral-cyst echogenicity is very low; it can even be anechoic. If a stereotaxic structure exists, indication of real time echography must be limited to such stereotaxy contraindications: threatening intracranial hypertension, suppurated lesion, fragile patient. The technique has its limit: that is the small volume of the target-lesion (inferior to 10 mm); advantages must be emphasized: light procedure, satisfying confidence when considering the probe progression, sometimes better information than that of a CT-Scan examination especially for tumoral and cystic lesions.