Optimizing Patient Care: A Multicentric Study on the Clinical Impact of Sim&Size™ Simulation Software in Intracranial Aneurysm Treatment With Pipeline Embolization Devices.

BACKGROUND: To determine the clinical effects (stent size, and number of stents used) of the Sim&Size™ simulation software on the endovascular treatment of unruptured saccular intracranial aneurysms with Pipeline Embolization Devices (PED). METHODS: This study is a retrospective analytical multicenter study of patients treated with PED (Flex and Flex with SHIELD) for intracranial aneurysm in FOSCAL clinic and CHU de Montpellier. RESULTS: The study included 253 patients, of which 75 were treated in Colombia and 178 were treated in France. The majority of patients were women (83.8%), with a median age of 57.48 years, and had large vessel location (88.1%), with most aneurysms located in the ICA paraclinoid segment (56.8%). Patients in the group with Sim&Size™ simulation had shorter stents than those without simulation (15.62 mm versus 17.36 mm, P-value = 0.001). Also, a lower proportion of these patients required more than one stent (1.4% versus 7.3%, P-value = 0.022). There were 7 complications reported in the group that used the Sim&Size™ simulation software, compared to 9 complications in the group that did not use the software. CONCLUSIONS: Using Sim&Size™ simulation software for endovascular treatment of patients with intracranial aneurysms using PED reduces the stent length and decreasing the number of devices needed per treatment.

Safety injections of nuclear medicine radiotracers: towards a new modality for a real-time detection of extravasation events and 18F-FDG SUV data correction.

BACKGROUND: 18F-FDG PET/CT imaging allows to study oncological patients and their relative diagnosis through the standardised uptake value (SUV) evaluation. During radiopharmaceutical injection, an extravasation event may occur, making the SUV value less accurate and possibly leading to severe tissue damage. The study aimed to propose a new technique to monitor and manage these events, to provide an early evaluation and correction to the estimated SUV value through a SUV correction coefficient. METHODS: A cohort of 70 patients undergoing 18F- FDG PET/CT examinations was enrolled. Two portable detectors were secured on the patients' arms. The dose-rate (DR) time curves on the injected DRin and contralateral DRcon arm were acquired during the first 10 min of injection. Such data were processed to calculate the parameters ΔpinNOR = (DRinmax- DRinmean)/DRinmax and ΔRt = (DRin(t) - DRcon(t)), where DRinmax is the maximum DR value, DRinmean is the average DR value in the injected arm. OLINDA software allowed dosimetric estimation of the dose in the extravasation region. The estimated residual activity in the extravasation site allowed the evaluation of the SUV's correction value and to define an SUV correction coefficient. RESULTS: Four cases of extravasations were identified for which ΔRt [(390 ± 26) µSv/h], while ΔRt [(150 ± 22) µSv/h] for abnormal and ΔRt [(24 ± 11) µSv/h] for normal cases. The ΔpinNOR showed an average value of (0.44 ± 0.05) for extravasation cases and an average value of (0.91 ± 0.06) and (0.77 ± 0.23) in normal and abnormal classes, respectively. The percentage of SUV reduction (SUV%CR) ranges between 0.3% and 6%. The calculated self-tissue dose values range from 0.027 to 0.573 Gy, according to the segmentation modality. A similar correlation between the inverse of ΔpinNOR and the normalised ΔRt with the SUV correction coefficient was found. CONCLUSIONS: The proposed metrics allowed to characterised the extravasation events in the first few minutes after the injection, providing an early SUV correction when necessary. We also assume that the characterisation of the DR-time curve of the injection arm is sufficient for the detection of extravasation events. Further validation of these hypotheses and key metrics is recommended in larger cohorts.

Middle meningeal artery embolization for chronic subdural hematomas. A systematic review of the literature focused on indications, technical aspects, and future possible perspectives.

Background: Chronic subdural hematoma (CSDH) is one of the most common neurosurgical diseases that affect elderly and fragile patients and as a consequence, management can be challenging. Surgery represents the standard treatment; however, alternative options are under investigation. Middle meningeal artery (MMA) embolization is considered a minimally invasive treatment although with poor evidence. In this review, we tried to summarize the findings about MMA embolization as a treatment for a CSDH to provide a useful guidance for clinical practice and for future speculative aspects. Methods: Literature review on PubMed until March 2021 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. We conducted a research on PubMed with a various combinations of the keywords "CSDH" and "middle meningeal artery" and "embolization," "refractory subdural hematoma," and then we reviewed the references of the relevant studies as additional source of eligible articles. Results: Among the 35 studies eligible for this review, 22 were case series, 11 were case reports, one was a technical note, and 1 was a randomized trial. A total of 746 patients were found in the literature. Failure rate of MMA embolization was between 3.9 and 8.9% of the cases according the indication to treat CSDH (upfront vs. after surgery). Conclusion: The global impression deriving from the data available and the literature is that MMA embolization is a safe procedure with very low complications and with a low failure rate, both when associated with surgery or in case of a standalone treatment.

Clinical, neuroradiological and genetic findings in a cohort of patients with multiple Cerebral Cavernous Malformations.

Cerebral cavernous malformations (CCM) consist of clusters of irregular dilated capillaries and represent the second most common type of vascular malformation affecting the central nervous system. CCM might be asymptomatic or cause cerebral hemorrhage, seizures, recurrent headaches and focal neurologic deficits. Causative mutations underlining CCM have been reported in three genes: KRIT1/CCM1, MGC4607/CCM2 and PDCD10/CCM3. Therapeutic avenues are limited to surgery. Here we present clinical, neuroradiological and molecular findings in a cohort of familial and sporadic CCM patients. Thirty subjects underwent full clinical and radiological assessment. Molecular analysis was performed by direct sequencing and MLPA analysis. Twenty-eight of 30 subjects (93%) experienced one or more typical CCM disturbances with cerebral/spinal hemorrhage being the most common (43%) presenting symptom. A molecular diagnosis was achieved in 87% of cases, with three novel mutations identified. KRIT1/CCM1 patients displayed higher risk of de novo CCMs appearance and bleedings. Magnetic Resonance Imaging (MRI) showed that infratentorial region was more frequently affected in mutated subjects while brainstem was often spared in patients with negative genetic testing.

How direct measurements of worker eyes with a Scheimpflug camera can affect lensdose coefficients in interventional radiology.

The 2013/59/Euratom Directive reduced the occupational exposure limits for the lens. Since it has become crucial to estimate the dose absorbed by the lens, we have studied the individual variability of exposed workers' ocular conformations with respect to the data estimated from their personal dosimetry. The anterior eye conformations of 45 exposed workers were acquired using Scheimpflug imaging and classified according to their sight conditions (emmetropia, myopia or hypermetropia). Three eye models were computed, with two lens reconstructions, and implemented in an interventional radiology scenario using Monte Carlo code. The models were dosimetrically analysed by simulating setup A, a theoretical monoenergetic and isotropic photon source (10-150 keV) and setup B, a more realistic interventional setting with an angiographic x-ray unit (50, 75, 100 kV peak). Scheimpflug imaging provided an average anterior chamber depth of (6.4 ± 0.5) mm and a lens depth of (3.9 ± 0.3) mm, together with a reconstructed equatorial lens length of (7.1-10.1) mm. Using these data for model reconstruction, dose coefficients (DCs) were simulated for all ocular structures. Regardless of the eye model used, the DCs showed a similar trend with radiation energy, which highlighted that for the same energy and setup, no significant dependence on ocular morphology and workers' visual conditions was observed. The maximum difference obtained did not exceed 1% for all eye models or structures analysed. Therefore, the individual variabilities of worker ocular anatomy do not require any additional correction, compared to the personal dosimetry data measured with a dedicated lens dosimeter. To estimate the dose absorbed by the other eye structures, it is, instead, essential to know the spectrum of the source that has generated the irradiation, since there are differences between monoenergetic sources and more realistic angiographic units.

Anterior cranial fossa dural arteriovenous fistula: Transarterial embolization from the ophthalmic artery as first-line treatment.

OBJECTIVE: To retrospectively review the outcome of patients with dural arteriovenous fistula of the anterior cranial fossa (afDAVF) treated by transarterial embolization. MATERIAL AND METHODS: Six consecutive patients were referred to our hospital for afDAVF treatment. After a multidisciplinary discussion, they underwent endovascular embolization with Onyx injection through the ophthalmic artery. Their clinical presentation, management and outcomes were retrospectively assessed. RESULTS: All interventions were performed with the liquid embolic agent Onyx through the transarterial route from the ophthalmic artery to access the fistulous point. All patients showed a good outcome with complete afDAVF obliteration. CONCLUSION: This study demonstrates that afDAVFs can be safely and completely obliterated by transarterial embolization via the ophthalmic artery.

DNA damage in lens epithelial cells exposed to occupationally-relevant X-ray doses and role in cataract formation.

The current framework of radiological protection of occupational exposed medical workers reduced the eye-lens equivalent dose limit from 150 to 20 mSv per year requiring an accurate dosimetric evaluation and an increase understanding of radiation induced effects on Lens cells considering the typical scenario of occupational exposed medical operators. Indeed, it is widely accepted that genomic damage of Lens epithelial cells (LEC) is a key mechanism of cataractogenesis. However, the relationship between apoptosis and cataractogenesis is still controversial. In this study biological and physical data are combined to improve the understanding of radiation induced effects on LEC. To characterize the occupational exposure of medical workers during angiographic procedures an INNOVA 4100 (General Electric Healthcare) equipment was used (scenario A). Additional experiments were conducted using a research tube (scenario B). For both scenarios, the frequencies of binucleated cells, micronuclei, p21-positive cells were assessed with different doses and dose rates. A Monte-Carlo study was conducted using a model for the photon generation with the X-ray tubes and with the Petri dishes considering the two different scenarios (A and B) to reproduce the experimental conditions and validate the irradiation setups to the cells. The simulation results have been tallied using the Monte Carlo code MCNP6. The spectral characteristics of the different X-ray beams have been estimated. All irradiated samples showed frequencies of micronuclei and p21-positive cells higher than the unirradiated controls. Differences in frequencies increased with the delivered dose measured with Gafchromic films XR-RV3. The spectrum incident on eye lens and Petri, as estimated with MCNP6, was in good agreement in the scenario A (confirming the experimental setup), while the mean energy spectrum was higher in the scenario B. Nevertheless, the response of LEC seemed mainly related to the measured absorbed dose. No effects on viability were detected. Our results support the hypothesis that apoptosis is not responsible for cataract induced by low doses of X-ray (i.e. 25 mGy) while the induction of transient p21 may interfere with the disassembly of the nuclear envelop in differentiating LEC, leading to cataract formation. Further studies are needed to better clarify the relationship we suggested between DNA damage, transient p21 induction and the inability of LEC enucleation.

Virtual simulation with Sim&Size software for Pipeline Flex Embolization: evaluation of the technical and clinical impact.

INTRODUCTION: During flow diversion, the choice of the length, diameter, and location of the deployed stent are critical for the success of the procedure. Sim&Size software, based on the three-dimensional rotational angiography (3D-RA) acquisition, simulates the release of the stent, suggesting optimal sizing, and displaying the degree of the wall apposition. OBJECTIVE: To demonstrate technical and clinical impacts of the Sim&Size simulation during treatment with the Pipeline Flex Embolization Device. METHODS: Consecutive patients who underwent aneurysm embolization with Pipeline at our department were retrospectively enrolled (January 2015-December 2017) and divided into two groups: treated with and without simulation. Through univariate and multivariate models, we evaluated: (1) rate of corrective intervention for non-optimal stent placement, (2) duration of intervention, (3) radiation dose, and (4) stent length. RESULTS: 189 patients, 95 (50.2%) without and 94 (49.7%) with software assistance were analyzed. Age, sex, comorbidities, aneurysm characteristics, and operator's experience were comparable among the two groups. Procedures performed with the software had a lower rate of corrective intervention (9% vs 20%, p=0.036), a shorter intervention duration (46 min vs 52 min, p=0.002), a lower median radiation dose (1150 mGy vs 1558 mGy, p<0.001), and a shorter stent length (14 mm vs 16 mm, p<0.001). CONCLUSIONS: In our experience, the use of the virtual simulation during Pipeline treatment significantly reduced the need for corrective intervention, the procedural time, the radiation dose, and the length of the stent.

Distal Thrombectomy with Headway Duo 167 cm and Catchview Mini Stent Retriever: A Technical Note.

BACKGROUND: M2 occlusions represent 16%-41% of all middle cerebral artery occlusions, with >50% of functional independence achieved. The American Heart Association/American Stroke Association 2018 guidelines suggest that, with a level of evidence B-R, thrombectomy with stent retrievers may be appropriate for selected patients with M2 or M3 occlusions. The purpose of this study is to illustrate a new technique of distal (M2-M3) thrombectomy. METHODS: Eight patients from May 2018 to February 2019 underwent a thrombectomy procedure for a M2 or M3 occlusion with a 3MAX or 4MAX intermediate aspiration catheter, a Headway Duo 167 cm microcatheter, and a Catchview Mini stent retriever. RESULTS: All thrombectomies were technically successful, defined as thrombolysis in cerebral infarction score ≤2b. Five out of the 8 patients attained a good functional outcome at 3 months, defined as modified Rankin scale score ≤2. CONCLUSIONS: This technique allows a safe and effective distal thrombectomy for M2-M3 occlusions.

Immediate Development of Dural Arteriovenous Fistula After Middle Meningeal Artery Embolization: First Angiographic Demonstration.

BACKGROUND: Cerebral dural arteriovenous fistulas (DAVFs) are vascular lesions consisting of a pathologic high-flow connection between dural arteries and veins or dural sinuses. Small DAVFs shunts have been demonstrated to exist physiologically, but as their estimated diameter is around 8-12 µm, they are not visible even on high-quality angiography studies. CASE DESCRIPTION: We report 2 cases of immediate development of a DAVF after embolization with microparticles of the middle meningeal artery for treatment of chronic subdural hematoma. CONCLUSIONS: This report represents the first description of sudden development of a DAVF after endovascular embolization of an intracranial artery and may shed light on the pathophysiology and development of DAVFs.

Three-Tesla magnetic resonance imaging of the vestibular endolymphatic space: A systematic qualitative description in healthy ears.

BACKGROUND AND PURPOSE: A detailed knowledge of the normal Magnetic Resonance (MR) anatomy of the vestibular endolymphatic space (ES) could be useful to understand the linkage between endolymphatic hydrops (EH) and Ménière's disease (MD). Our aim was to describe the MR anatomy of the vestibular ES as depicted by MR imaging in healthy ears. METHODS: This report describes a single-center retrospective study. Three readers analyzed the healthy ears of 22 consecutive patients who had undergone MRI for unilateral sudden hearing loss. The readers described the vestibular ES based on a delayed post-contrast 3D-FLAIR sequence according to six well-defined planes, three oblique sagittal (lateral, intermediate and medial) planes and three axial (superior, intermediate and inferior) planes. RESULTS: On sagittal lateral and intermediate planes, we identified the SSC ampulla combined with the utricle in 22/22 ears. On the sagittal medial plane, the saccule was detectable in 15/22 (68%) ears, having a club shape with the long axis oriented cranio-caudally; in 7/22 (32%) ears, the saccule presented an oval/round shape that appeared more conspicuously on the axial intermediate plane. The ES occupied the half superior portion of the vestibule in 22/22 ears, never contacting the round and oval windows. On the axial plane, in 17/22 cases, the ES showed a Y-shaped arrangement, while in 5/22 ears (23%), the ES presented a more globular shape. CONCLUSION: MR imaging represents a valid tool to explore the in vivo anatomy of the vestibular ES and to highlight its variability in normal ears.

Flat-panel CT versus 128-slice CT in temporal bone imaging: Assessment of image quality and radiation dose.

OBJECTIVE: We compared the image quality and radiation dose of flat-panel CT (FPCT) and multi-slice CT (MSCT) performed respectively with an angiographic unit and a 128-slice CT scanner. We investigated whether the higher spatial resolution of FPCT translated into higher image quality and we sought to eliminate inter-subject variability by scanning temporal bone specimens with both techniques. MATERIALS AND METHODS: Fifteen temporal bone specimens were imaged with FPCT and MSCT. Two neuroradiologists experienced in otoradiology evaluated 30 anatomical structures with a 0-2 score; 18 structures important from a clinical perspective were assigned a twofold value in calculation of the overall score. The radiation dose was calculated through the use of an anthropomorphic phantom. RESULTS: The image quality was significantly higher for FPCT than MSCT for 10 of the 30 anatomical structures; the overall score was also significantly higher for FPCT (p = 0.001). The equivalent dose of the two techniques was very similar, but with different effective doses to the organs. CONCLUSION: FPCT performed on an angiographic unit provides higher image quality in temporal bone assessment compared to MSCT performed on a 128-slice CT scanner thanks to its higher spatial resolution, with comparable equivalent doses but different effective doses to the organs.

Contrast agents in diagnostic imaging: Present and future.

Specific contrast agents have been developed for x ray examinations (mainly CT), sonography and Magnetic Resonance Imaging. Most of them are extracellular agents which create different enhancement on basis of different vascularization or on basis of different interstitial network in tissues, but some can be targeted to a particular cell line (e.g. hepatocyte). Microbubbles can be used as carrier for therapeutic drugs which can be released in specific targets under sonographic guidance, decreasing systemic toxicity and increasing therapeutic effect. Radiologists have to choose a particular contrast agent knowing its physical and chemical properties and the possibility of adverse reactions and balancing them with the clinical benefits of a more accurate diagnosis. As for any drug, contrast agents can cause adverse events, which are more frequent with Iodine based CA, but also with Gd based CA and even with sonographic contrast agents hypersensitivity reaction can occur.

The role of stereotactic body radiation therapy (SBRT) in the treatment of oligometastatic disease in the elderly.

OBJECTIVE: To report about clinical outcome of stereotactic body radiation therapy (SBRT) in the treatment of oligometastatic disease in elderly patients. METHODS: Patients with 1-4 inoperable metastases were treated with SBRT. Dose prescription ranged from 40 to 75 Gy in 3-8 fractions. SBRT was delivered using the volumetric modulated arc therapy technique with flattening filter-free photon beams. The primary end points were in-field local control (LC) and toxicity. Secondary end points were overall survival (OS) and disease-specific survival (DSS). RESULTS: 82 patients with 111 total metastases were treated. Median age was 79 years. 64 patients (78%) had a single lesion; the remaining patients had 2-4 lesions. 16 (14.4%) lesions were localized in the abdomen, 50 (45.0%) in the liver and 45 (40.5%) in the lungs. Local response was observed for 87 lesions (78.4%) while local progression was observed in 24 lesions (21.6%). Actuarial 1-year LC was 86.8% ± 3.3%. Actuarial 1-year OS was 93.6% ± 2.7%. 2-year findings were 76.3% ± 4.4% and 72.0% ± 5.6%, respectively. Actuarial 1- and 2-year DSS results were 97.5% ± 2.0% and 81.6% ± 4.9%, respectively. Treatment-related Grade 2-3 toxicity was observed in five patients (4.2%); Grade 1 toxicity in seven patients (5.9%) and no toxicity was observed in 85.4% of the cases. CONCLUSION: SBRT is a safe and effective therapeutic option for the treatment of oligometastatic disease in the elderly with acceptable rates of LC and low treatment-related toxicity. ADVANCES IN KNOWLEDGE: The use of SBRT for oligometastatic disease in the elderly can be considered as a valuable approach, particularly for patients with fragile status or refusing other approaches.