Intraoperative Staff Radiation Exposure During Aortic Endovascular Procedures.

BACKGROUND: The risk of radiation exposure in the surgical operating room (OR) and/or catheterization laboratory is now well established. Complex endovascular procedures often require multiple approaches and different positioning of the staff members around the patient, potentially increasing the levels of radiations exposure. Our goal was to evaluate the levels of radiation exposure of the members of the staff during endovascular aortic procedures in order to propose radioprotection optimization. METHODS: We included 41 aortic endovascular procedures out of 114 procedures performed between January 12, 2014, and August 31, 2015, including 24 standard endovascular aortic aneurysm repair (EVAR), 7 EVAR with iliac branch (EVARib), 8 complex fenestrated/branched EVAR (F/B EVAR), and 2 thoracic EVAR (TEVAR). Procedures were performed in an OR equipped with a carbon fiber table and a mobile fluoroscopy C-arm. We collected the usual dosimetry data given by the C-arm as well as the patient's peak skin dose (PSD). In all staff members, radiation exposure was measured with thermoluminescent chip dosimeters placed on both temples, on posterior sides of both hands, and on both lower legs. RESULTS: PSD levels were low for EVAR because 24 patients had values below the reading threshold. PSD significantly increased with more complex procedures. Main operator (MO) received the higher level of irradiation on whole body, hands, and ankles. Eye lenses irradiation was higher on both assistant operators (AOs). Other members received low levels of irradiation. We found a high ranges of radiation exposure with a high risk of exposure for the AO, mainly for F/B EVAR and EVARib. CONCLUSIONS: Even if all personal protections are used, staff positioning is a major point that must be considered. If MO is supposed to be the most exposed to X-rays, specific conditions of positioning of the AO may be at risk of exposure.

Treatment with flow diverter stent during pregnancy.

Intracranial aneurysms are rarely diagnosed during pregnancy. If treatment is necessary, surgery was traditionally preferred over embolization in case of ongoing pregnancy, due to concerns regarding foetal radiation exposure. We present a case of 21 mm unruptured carotid-ophthalmic aneurysm diagnosed during pregnancy and treated with flow diversion. Foetal radiation dose was estimated between 1 and 5 mGy, well below recommended limits. Double antiplatelet therapy with prasugrel and aspirin was administered between week 17 and week 37, followed by uneventful vaginal delivery at 39 weeks. The new-born infant did not present any clinical abnormalities. Post-natal angiography showed complete aneurysm occlusion. To our knowledge, this is the first report of flow diverter stent placement during ongoing pregnancy. Although a good outcome was observed in this case, this result should be interpreted with caution. Further studies are needed in order to better define the safety profiles of intracranial stents and double antiplatelet therapies during pregnancy.

A new method of real-time skin dose visualization. Clinical evaluation of fluoroscopically guided interventions.

INTRODUCTION: We have conducted a prospective study to clinically evaluate a new radiation dose observing tool that displays patient's peak skin dose (PSD) map in real time. METHODS: The skin dose map (SDM) prototype quantifies the air kerma based on exposure parameters from the X-ray system. The accuracy of this prototype was evaluated with radiochromic films, which were used as a mean for PSD measurement. RESULTS: The SDM is a reliable tool that provides an accurate PSD estimation and location. CONCLUSION: SDM also has many advantages over the radiochromic films, such as real-time dose evaluation and easy access to critical operational parameters for physicians and technicians.

Xray Exposure Time in Dedicated Academic Simulation Programs Is Realistic of Patient Procedures.

OBJECTIVE: To ascertain whether simulated endovascular procedures are comparable to real life operating room (OR) procedures, particularly with regard to irradiation time. METHODS: This was a retrospective study comparing simulation with clinical data. Fluoroscopy time and overall operation time were compared between simulated abdominal aortic endovascular repair (EVAR) and iliac procedures that were performed, respectively, from 2016 to 2019 and from 2015 to 2019, and clinical EVAR and iliac procedures performed in the OR between January 2018 and November 2021. RESULTS: Within the defined periods, 171 simulated procedures (91 EVAR, 80 iliac) and 199 clinical procedures (111 EVAR, 88 iliac) were performed. For both EVAR and iliac procedures, median total procedure time was much longer during real surgery (p < .001). However, median total fluoroscopy time remained the same, whether the procedure was real surgery or performed on the simulator, for iliac procedures (8.47 minutes in the OR, 8.35 minutes on the simulator, p = .61) and for EVAR procedures (14.80 minutes in the OR, 15.00 minutes on the simulator p = .474). CONCLUSION: Simulated endovascular procedures are comparable with real life OR procedures, particularly with regard to irradiation time when integrated in a dedicated curriculum.

Liver-Directed Therapy for Neuroendocrine Metastases: From Interventional Radiology to Nuclear Medicine Procedures.

Neuroendocrine neoplasms (NENs) are rare and heterogeneous epithelial tumors most commonly arising from the gastroenteropancreatic (GEP) system. GEP-NENs account for approximately 60% of all NENs, and the small intestine and pancreas represent two most common sites of primary tumor development. Approximately 80% of metastatic patients have secondary liver lesions, and in approximately 50% of patients, the liver is the only metastatic site. The therapeutic strategy depends on the degree of hepatic metastatic invasion, ranging from liver surgery or percutaneous ablation to palliative treatments to reduce both tumor volume and secretion. In patients with grade 1 and 2 NENs, locoregional nonsurgical treatments of liver metastases mainly include percutaneous ablation and endovascular treatments, targeting few or multiple hepatic metastases, respectively. In the present work, we provide a narrative review of the current knowledge on liver-directed therapy for metastasis treatment, including both interventional radiology procedures and nuclear medicine options in NEN patients, taking into account the patient clinical context and both the strengths and limitations of each modality.

Beam hardening artifacts of liquid embolic agents: comparison between Squid and Onyx.

BACKGROUND: Initial clinical experience with Squid shows subjectively reduced artifacts on post-embolization CT scans compared with Onyx. To further investigate these observations, we aimed to perform a comparison of artifacts between Squid and Onyx in a controlled in vitro model. MATERIALS AND METHODS: Onyx 18 and all four variants of Squid (Squid 18, Squid 18 low density (LD), Squid 12, Squid 12 LD) were each injected in dimethylsulfoxide (DMSO) compatible test tubes. The tubes containing precipitated embolic material were inserted in a CT phantom for conventional and flat panel CT acquisitions. Beam hardening artifacts were quantified using objective and subjective measurements. RESULTS: Objective evaluation of artifacts within regions of interest (ROIs) placed around the embolic material on CT and flat panel CT images demonstrated significantly lower noise and Hounsfield unit (HU) range values for all four Squid products compared with Onyx 18. On both CT and flat panel CT, LD variants of Squid 18 and Squid 12 had significantly lower noise and HU range values than their normal density counterparts on longitudinal ROIs. When using subjective measures for diagnostic value within ROIs placed around the embolic material on both CT and flat panel CT images, the number of non-diagnostic ROIs was significantly higher for Onyx 18 than for all four Squid variants. CONCLUSION: All four variants of Squid induced fewer beam hardening artifacts than Onyx 18 on CT and flat panel CT acquisitions. LD variants of Squid induced fewer artifacts than their normal density counterparts.

Assessment of left ventricular perfusion, volumes, and motion in mice using pinhole gated SPECT.

UNLABELLED: Quantitative functional normal data should be a prerequisite before applying SPECT in murine models of cardiac disease. Therefore, we investigated the capability of in vivo pinhole gated SPECT for establishment of a reference database for left ventricular myocardial perfusion, volumes, and motion in normal mice. METHODS: A small-animal dedicated pinhole gamma-camera with a field of view of 17 cm and a focal distance of 12 cm was used with a 1.5-mm pinhole and a 2.5-cm radius of rotation. Phantoms were designed to test spatial resolution and microvolume measurements of accuracy. Eight adult normal mice (CD1) were studied using a heated mixture of air (0.3 L/min) and 1.5%-2.5% isoflurane for anesthesia. For myocardial perfusion, 350-450 MBq of (99m)Tc-tetrofosmin were used in 0.15-0.25 mL. Gated acquisitions (8 or 10 time bins per cardiac cycle) were obtained using a 180 degrees circular arc and 48 anterior projections of 300 R-R intervals. Image reconstruction was done using a specific Algebraic Reconstruction Technique (ART) cone-beam algorithm. For quantification, reconstructed images were processed using standard nuclear medicine software. RESULTS: Millimetric spatial resolution and volume calibration linear relationships (r(2) = 0.99) in the 10- to 100-muL range were obtained in phantoms and used to scale in vivo volume values. In mice, left ventricular perfusion was lower in the apex (65% +/- 6%) versus lateral (72% +/- 5%), inferior (74% +/- 5%), septum (75% +/- 4%), and anterior (74% +/- 2%) walls. The left ventricular ejection fraction was 60% +/- 9%, end-diastolic volume was 50 +/- 8 muL, end-systolic volume was 20 +/- 6 muL, stroke volume was 29.5 +/- 6 muL, and cardiac output was 9.6 +/- 1.6 mL/min. Wall thickening was higher in the apex (47% +/- 12%) versus lateral (30% +/- 9%), inferior (33% +/- 8%), septum (37% +/- 10%), and anterior (33% +/- 10%) walls. CONCLUSION: This work shows that in vivo pinhole gated SPECT can be used for assessment of left ventricular perfusion, volumes, and cardiac function in normal mice.

[Sentinel lymph node biopsy with micrometastases in breast cancer: histological data and surgical implications. About a series of 201 axillary dissections after peroperative sentinel node identification]. / Ganglions sentinelles avec micrométastases dans le cancer du sein: données histologiques et implications chirurgicales. A propos d'une série de 201 curages axillaires après identification peropératoire des ganglions sentinelles.

The benefit of systematic dissection of the non-sentinel lymph nodes (NSLN) in case of micrometastases (> or = 2 mm) in sentinel lymph nodes (SLN) is still being debated. The purpose of this work was to identify, from the histological characteristics of the micrometastases and the primitive tumors out of a series of 201 invasive breast carcinomas, of which 57.2% were pTl, which axillary dissection could be avoided. All cases had axillary dissection after peroperative SLN identification. The SLN were examined after fixation hy HE and immunohistochemical techniques (IHC), over their entire thickness from 2 to 3 mm-thick blocks of tissue and according to levels of histological sections with a spacing of 500 microm. The SLN were metastasized in 87/201 cases (43.3%) and in 29/8 7 cases (33.3%) it concerned micrometastases, 2/3 of which was only detected by IHC. The ability to discover micrometastases was proportional to the number of histological sections analyzed (58.6%, 82.7% and 100% of discovery with 1, 3 and 5 levels per block respectively). In 8/29 cases (27.6%) the NSLN were metastasized and in 6/8 cases it concerned macrometastases (> 2 mm). Taken separately, the characteristics of the tumors (size, histological type, grading, angioinvasion, multifocality), of the micrometastases (HE detection vs IHC detection, size, number) and of the site of injection of the radiotracer (peritumoral versus sub-areolar) did not allow us to isolate a group with micrometastases in the SLN but without metastases in the NSLN. However, the nine pT1 ductal carcinomas without angioinvasion were all NSLN negative. In conclusion, these results show that identification of micrometastases in SLN may influence the surgical decisions of re-excision, and that methodology of the pathological analysis is determinant.

Osteoblastoma and osteoid osteoma: morphofunctional characterization by MRI and dynamic F-18 FDG PET/CT before and after radiofrequency ablation.

Osteoblastoma (OB) and osteoid osteoma (OO) are benign bone-forming tumors frequently involving vertebrae and long bones of the extremities. Because of their similar histopathological features, distinction between OB and OO is mostly based on size criteria. CT and MRI represent the cornerstone of noninvasive diagnostic procedures, as they provide excellent morphologic details and often obviate the need for confirmatory biopsy. Bone scan is a complementary, highly sensitive functional technique particularly useful for detection of vertebral OO. F-18 FDG PET/CT could have potentiality in diagnosis and post therapeutic evaluation of patients with OB and OO. We report MRI and dynamic F-18 FDG PET/CT results obtained before radiofrequency or laser ablation from 3 patients with an OB of the right L5 pedicle, an OB of the left talus and an OO of the right acetabulum. Both patients with OB underwent posttherapeutic evaluation to confirm the effectiveness of percutaneous radiofrequency ablation.