Safety and efficacy of cryoablation of Soft-Tissue tumors.

OBJECTIVES: To assess the safety and efficacy of percutaneous cryoablation (CA) of soft-tissue tumors (desmoid tumors (DT), vascular malformations (VM), and abdominal wall endometriosis (AWE)). METHODS: This systematic review of studies published before January 2024 encompassed a detailed analysis of CA techniques and technical aspects for the treatment of soft-tissue tumors. Data concerning CA efficacy, complication rates, and other relevant metrics was extracted and included for analysis. RESULTS: The analysis included 27 studies totaling 554 CA procedures. For DT (13 studies, 393 sessions), CA showed an average pain reduction of 79 ± 17% (range: 57-100) and a lesion volume decrease of 71.5 ± 9.8% (range: 44-97). VM (4 studies, 58 sessions) had a 100% technical success rate and an average pain reduction of 72 ± 25% (range: 63-85). The average pain reduction for AWE (6 studies, 103 sessions) was 82 ± 13% (range: 62-100). Overall, the complication rate for CA was low, with minor adverse events (AE) in about 20% of patients and major events in less than 5% of patients. CONCLUSION: Showing substantial efficacy in pain reduction and lesion volume decrease, as well as low incidence of severe AE, CA presents as a highly effective and safe alternative for the treatment of soft-tissue tumors. ADVANCES IN KNOWLEDGE: CA is effective and safe in treating soft-tissue tumors, particularly DT, VM, and AWE.

Combined vertebroplasty and pedicle screw insertion for vertebral consolidation: feasibility and technical considerations.

PURPOSE: To assess the feasibility and technical accuracy of performing pedicular screw placement combined with vertebroplasty in the radiological setting. METHODS: Patients who underwent combined vertebroplasty and pedicle screw insertion under combined computed tomography and fluoroscopic guidance in 4 interventional radiology centers from 2018 to 2023 were retrospectively assessed. Patient demographics, vertebral lesion type, and procedural data were analyzed. Strict intra-pedicular screw positioning was considered as technical success. Pain score was assessed according to the Visual Analogue Scale before the procedure and in the 1-month follow-up consultation. RESULTS: Fifty-seven patients (38 men and 19 women) with a mean age of 72.8 (SD = 11.4) years underwent a vertebroplasty associated with pedicular screw insertion for the treatment of traumatic fractures (29 patients) and neoplastic disease (28 patients). Screw placement accuracy assessed by post-procedure CT scan was 95.7% (89/93 inserted screws). A total of 93 pedicle screw placements (36 bi-pedicular and 21 unipedicular) in 32 lumbar, 22 thoracic, and 3 cervical levels were analyzed. Mean reported procedure time was 48.8 (SD = 14.7) min and average injected cement volume was 4.4 (SD = 0.9) mL. A mean VAS score decrease of 5 points was observed at 1-month follow-up (7.7, SD = 1.3 versus 2.7, SD = 1.7), p < .001. CONCLUSION: Combining a vertebroplasty and pedicle screw insertion is technically viable in the radiological setting, with a high screw positioning accuracy of 95.7%.

Interventional Oncology: 2024 Update.

Interventional Oncology (IO) stands at the forefront of transformative cancer care, leveraging advanced imaging technologies and innovative interventions. This narrative review explores recent developments within IO, highlighting its potential impact facilitated by artificial intelligence (AI), personalized medicine and imaging innovations. The integration of AI in IO holds promise for accelerating tumour detection and characterization, guiding treatment strategies and refining predictive models. Imaging modalities, including functional MRI, PET and cone beam CT are reshaping imaging and precision. Navigation, fusion imaging, augmented reality and robotics have the potential to revolutionize procedural guidance and offer unparalleled accuracy. New developments are observed in embolization and ablative therapies. The pivotal role of genomics in treatment planning, targeted therapies and biomarkers for treatment response prediction underscore the personalization of IO. Quality of life assessment, minimizing side effects and long-term survivorship care emphasize patient-centred outcomes after IO treatment. The evolving landscape of IO training programs, simulation technologies and workforce competence ensures the field's adaptability. Despite barriers to adoption, synergy between interventional radiologists' proficiency and technological advancements hold promise in cancer care.

Review of craniofacial pain syndromes involving the greater occipital nerve: relevant anatomy, clinical findings, and interventional management.

Craniofacial pain syndromes exhibit a high prevalence in the general population, with a subset of patients developing chronic pain that significantly impacts their quality of life and results in substantial disabilities. Anatomical and functional assessments of the greater occipital nerve (GON) have unveiled its implication in numerous craniofacial pain syndromes, notably through the trigeminal-cervical convergence complex. The pathophysiological involvement of the greater occipital nerve in craniofacial pain syndromes, coupled with its accessibility, designates it as the primary target for various interventional procedures in managing craniofacial pain syndromes. This educational review aims to describe multiple craniofacial pain syndromes, elucidate the role of GON in their pathophysiology, detail the relevant anatomy of the greater occipital nerve (including specific intervention sites), highlight the role of imaging in diagnosing craniofacial pain syndromes, and discuss various interventional procedures such as nerve infiltration, ablation, neuromodulation techniques, and surgeries. Imaging is essential in managing these patients, whether for diagnostic or therapeutic purposes. The utilization of image guidance has demonstrated an enhancement in reproducibility, as well as technical and clinical outcomes of interventional procedures. Studies have shown that interventional management of craniofacial pain is effective in treating occipital neuralgia, cervicogenic headaches, cluster headaches, trigeminal neuralgia, and chronic migraines, with a reported efficacy of 60-90% over a duration of 1-9 months. Repeated infiltrations, neuromodulation, or ablation may prove effective in selected cases. Therefore, reassessment of treatment response and efficacy during follow-up is imperative to guide further management and explore alternative treatment options. Optimal utilization of imaging, interventional techniques, and a multidisciplinary team, including radiologists, will ensure maximum benefit for these patients.

Vertebroplasty versus bracing in acute vertebral compression fractures: A prospective randomized trial.

BACKGROUND: The treatment of stable vertebral compression fractures remains controversial. OBJECTIVE: To compare the efficacy of vertebroplasty and bracing for acute vertebral compression fractures. METHODS: We conducted a prospective, randomized, non-blinded, single-center study. Adult participants were randomized to undergo vertebroplasty or bracing. Both groups were stratified by age. The primary outcome was functional disability (Roland-Morris disability questionnaire [RMDQ]). Secondary outcomes were pain intensity (Visual Analogue Scale [VAS]), and change in vertebral body height and kyphosis angle. Outcomes were assessed on day 2, and 1, 3 and 6 months after treatment. RESULTS: Ninety-nine people were included, 51 in the vertebroplasty group and 48 in the brace group. Treatment was performed within 2 weeks of the trauma. On day 2 post-treatment, pain was lower in the vertebroplasty group (mean [SD] 2.3 [1.5] versus 3.4 [2.1], p = 0.004) but the difference was no longer significant at 6 months. Functional disability was significantly lower in the vertebroplasty than brace group at all time-points (RMDQ score 7.5 [5.7] vs 11.4 [5.3], p<0.001 at 1 month). At 6 months, the increase in kyphosis angle was smaller in the vertebroplasty than the brace group (+1.5°versus +4°, p<0.001). CONCLUSION: In people with acute vertebral compression fractures, the immediate effect of vertebroplasty was greater than that of bracing on pain and function, and for restoring sagittal balance. At 6 months, the superiority of vertebroplasty decreased, except for the maintenance of sagittal balance. DATABASE REGISTRATION: ClinicalTrials.gov number, NCT01643395.

Patient's Selection and Evaluation for Bone Stabilization.

Bone stabilization procedures performed by Interventional Radiologists have significantly increased in the past ten years with a wide variety of techniques available ranging from cementoplasty to complex combined treatment associating thermoablation, cementoplasty and fixation. Many available manuscripts and reviews focus on the technical aspects, feasibility and outcomes of these procedures. However, not every procedure is suitable for every patient, and therefore selecting a patient for a specific procedure represents the first necessary step to a successful procedure. This review will describe every step of the selection process which the Interventional Radiologists is confronted with prior to performing a consolidation procedure in the setting of bone cancer. Defining the clinical setting is mandatory and includes assessing the patient's clinical status, cancer stage, level of pain and disability will help define the objective of the procedure: curative, palliative intent. A thorough imaging assessment is also mandatory, as it will define the type of consolidation (cementoplasty or fixation) which will be performed depending on the anatomical location and size of the lesion, the type of stresses at stake (compression or shear) and it will help plan the needle pathway and assess for possible complications. The process of selecting a patient for a specific procedure should be performed by the Interventional Radiologist but should be validated in a multidisciplinary approach. Moreover, the objective of a procedure, including the expected outcome and possible adverse events and complications should clearly be explained to the patient.

Bipolar Radiofrequency Ablation of Painful Spinal Bone Metastases Performed under Local Anesthesia: Feasibility Regarding Patient's Experience and Pain Outcome.

Background and objectives: To assess the pain relief of bipolar RFA combined or not with vertebroplasty in patients with painful vertebral metastases and to evaluate the feasibility and tolerance of the RFA procedure performed under local anesthesia. Materials and Methods: 25 patients (18 men, 7 women, mean age: 60.X y.o) with refractory painful vertebral metastasis were consecutively included between 2012 and 2019. A total of 29 radiofrequency ablation (RFA) procedures were performed under CT guidance, local anesthesia and nitrous oxide inhalation, including 16 procedures combined with vertebroplasty for bone consolidation purposes. Pain efficacy was clinically evaluated using the visual analogue scale (VAS) at day 1, 1 month, 3 months, 6 months and 12 months, and the tolerance of the procedure was evaluated. Results: Procedure tolerance was graded as either not painful or tolerable in 97% of cases. Follow-up postprocedure mean VAS score decrease was 74% at day 1: 6.6 (p < 0.001), 79% at 1 month: 6.6 (p < 0.001), 79% at 3 months: 6.5 (p < 0.001), 77% at 6 months, and 79% at 12 months: 6.6 (p < 0.001). Conclusions: Bipolar RFA, with or without combined vertebroplasty, appears to be an effective and reliable technique for the treatment of refractory vertebral metastases in patients in the palliative care setting. It is a feasible procedure under local anesthesia which is well tolerated by patients therefore allowing to broaden the indications of such procedures. Field of study: interventional radiology.

Assessment of Apparent Diffusion Coefficients and SUVs as Predicators of Histological Differentiation in Anal Squamous Cell Carcinoma.

AIM: The study aims to assess minimal apparent diffusion coefficient (ADCmin) and SUVmax as predictors of histological differentiation in patients with anal squamous cell carcinoma (ASCC) and to determine cutoff values for each histopathological tumor grade. PATIENTS AND METHODS: A retrospective study of 41 ASCC patients (14 males, 27 females; mean age, 65 ± 13 years) staged with FDG PET/CT and MRI (mean scan time interval, 21 ± 11 days). SUVmax and ADCmin values were measured and compared with histopathological tumor grading obtained from biopsy. RESULTS: The mean size and tumor volume were 3 ± 2 cm and 16.5 ± 27.3 cm3, respectively. The mean ADCmin values for well-, moderately, and poorly differentiated ASCC were 935 ± 179, 896 ± 123, and 637 ± 114, respectively. The mean SUVmax for well-, moderately, and poorly differentiated ASCC were 6.9 ± 1.8, 11.5 ± 4.1, and 13.4 ± 2.6, respectively. The difference in mean ADCmin values between poorly and moderately/well-differentiated tumors was statistically significant, whereas this was not significant between moderately and well-differentiated tumors. Differences in SUVmax values were statistically significant between poorly/moderately and well-differentiated tumors, whereas there was no statistical significance between poorly and moderately differentiated tumors. By combining the 2 modalities using cutoff values of 675 × 10-6 mm2·s-1 for ADCmin and 8.5 for SUVmax, it was possible to differentiate the tumor categories with a sensitivity, specificity, positive predictive value, and negative predictive value, respectively, of 84.6%, 96.4%, 91.7%, and 93.1% for well-differentiated ASCC, 76.5%, 87.5%, 81.3%, and 84% for moderately, and 90.9%, 89.3%, 76.9%, and 96.2% for poorly differentiated ASCC, respectively. CONCLUSIONS: ADCmin and SUVmax values correlated with the degree of differentiation in ASCC and can be used as predictors of tumor grading and aggressiveness. Combined ADCmin and SUVmax cutoff values can therefore be used for early patient risk stratification and treatment decision making.

Male Sex Is Associated With Cervical Artery Dissection in Patients With Fibromuscular Dysplasia.

Background Cervical artery dissection (CeAD) is a frequent manifestation of fibromuscular dysplasia (FMD). However, risk factors for CeAD are unknown. We investigated factors associated with CeAD in the ARCADIA (Assessment of Renal and Cervical Artery Dysplasia) registry. Methods and Results The ARCADIA registry includes women or men aged ≥18 years, with a diagnosis of renal, cervical, or intracranial artery FMD, who were prospectively recruited at 16 university hospitals in France and Belgium. Diagnosis of acute or past CeAD at inclusion was established on imaging according to standard diagnostic criteria. Associations between potential determinants and CeAD were assessed by logistic regression analyses. Among 469 patients (75 men) with FMD, 65 (13.9%) had CeAD. Patients with CeAD were younger, more likely to be men, have a history of migraine, and less likely to have a history of hypertension than patients without CeAD. In the multivariable analysis, male sex (odds ratio [OR], 2.66; 95% CI, 1.34-5.25), history of migraine (OR, 1.90; 95% CI, 1.06-3.39), age ≥50 years (OR, 0.41; 95% CI, 0.23-0.73), history of hypertension (OR, 0.35; 95% CI, 0.20-0.64), and involvement of ≥3 vascular beds (OR, 2.49; 95% CI, 1.15-5.40) were significantly associated with CeAD. To validate the association between CeAD and sex, we performed a systematic review. We collected additional data on sex from 2 published studies and unpublished data from the US Registry for Fibromuscular Dysplasia and the European/International FMD Registry. In the pooled analysis (289 CeAD, 1933 patients), male sex was significantly associated with CeAD (OR, 2.04; 95% CI, 1.41-2.95; I2=0%). Conclusions In patients with FMD, male sex and multisite involvement are associated with CeAD, in addition to other previously known risk factors. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02884141.

Trans-isthmic pars interarticularis screw fixation under CT and fluoroscopic guidance: technical success and clinical outcome in patients with symptomatic low-grade lumbar isthmic lysis.

OBJECTIVES: To assess the technical success of trans-isthmic screw fixation with simultaneous CT and fluoroscopic guidance in patients with symptomatic low-grade isthmic spondylolisthesis. METHODS: Fifty patients (28 women and 22 men; mean age ± standard deviation: 50 years ± 18.9) presenting with symptomatic low back pain with isthmic spondylolisthesis refractory to medical management were treated by means of trans-isthmic pars interarticularis percutaneous screw fixation. The procedure was performed under local anesthesia with double CT and fluoroscopic guidance. Primary outcome was technical success of the procedure, which was assessed with a post-procedure CT using the same success criteria as surgical screw placement with regard to entry point, trajectory, and screw tip. Secondary outcome was pain decrease assessed by the Visual Analog Scale (VAS). RESULTS: Ninety-nine procedures were performed in 50 patients and 99 screws were inserted. Postoperative CT assessment showed satisfactory screw placement in 96 cases, reflecting a technical success rate of 96.9%. No complications occurred during or after the procedure. Pain assessment showed a pain decrease of VAS score from a median of 7 (min 5, max 10; MAD 1.4) to 2 (p < 0.0001) (min 0, max 7, MAD 1.7) with a mean follow-up of 39 months. CONCLUSION: Trans-isthmic screw fixation performed under CT and fluoroscopic guidance presents a high technical success and appears as a safe procedure and effective procedure in patients with symptomatic low-grade isthmic lysis. KEY POINTS: • Trans-isthmic pars interarticularis percutaneous screw insertion is feasible under double CT and fluoroscopic guidance by a radiologist with a high technical success. • This technique can be performed under local anesthesia only. • In patients with chronic low back pain, isthmic screwing allows long-term pain improvement.

Automated Quantification of Brain Lesion Volume From Post-trauma MR Diffusion-Weighted Images.

Objectives: Determining the volume of brain lesions after trauma is challenging. Manual delineation is observer-dependent and time-consuming and cannot therefore be used in routine practice. The study aimed to evaluate the feasibility of an automated atlas-based quantification procedure (AQP) based on the detection of abnormal mean diffusivity (MD) values computed from diffusion-weighted MR images. Methods: The performance of AQP was measured against manual delineation consensus by independent raters in two series of experiments based on: (i) realistic trauma phantoms (n = 5) where low and high MD values were assigned to healthy brain images according to the intensity, form and location of lesion observed in real TBI cases; (ii) severe TBI patients (n = 12 patients) who underwent MR imaging within 10 days after injury. Results: In realistic TBI phantoms, no statistical differences in Dice similarity coefficient, precision and brain lesion volumes were found between AQP, the rater consensus and the ground truth lesion delineations. Similar findings were obtained when comparing AQP and manual annotations for TBI patients. The intra-class correlation coefficient between AQP and manual delineation was 0.70 in realistic phantoms and 0.92 in TBI patients. The volume of brain lesions detected in TBI patients was 59 ml (19-84 ml) (median; 25-75th centiles). Conclusions: Our results support the feasibility of using an automated quantification procedure to determine, with similar accuracy to manual delineation, the volume of low and high MD brain lesions after trauma, and thus allow the determination of the type and volume of edematous brain lesions. This approach had comparable performance with manual delineation by a panel of experts. It will be tested in a large cohort of patients enrolled in the multicenter OxyTC trial (NCT02754063).

Lumbar medial branch cryoneurolysis under ultrasound guidance: initial report of five cases.

AIMS: To assess the feasibility and preliminary results of ultrasound guided medial branch cryoneurolysis in the management of facet joint syndrome. MATERIAL AND METHODS: Between March 2017 and August 2017, a total of 20 patients underwent medial branch blocks, 12 of which were positive. Five patients chose to participate in the study and 8 medial branch cryoneurolysis were performed. The primary endpoint of the study was the feasibility of the procedure. The secondary endpoint was the efficacy on pain assessed over the following year after the procedure. RESULTS: Technical feasibility of cryoneurolysis under ultrasound guidance was 100%. Accurate needle positioning at the accurate target in the angle between the posterior aspect of the transverse process and the lateral aspect of the facet joint was achieved in all cases. Needle progression could be depicted with US guidance in all cases. Mean pre-procedural Visual Analogue Scale and Oswestry disability Index scores were 6.8 (range 5-8) and 20.6 (range 12- 31), respectively. Follow up showed a decrease of Visual Analogue Scale score at one month (1.75, range 0-7), and at three months (1.75 range 0-3), Mean self-reported improvement at 6 months was 76% (60- 100%) and 77% at 12 months (50-100%). We report one case of failure at one month. No complications were noted during or after the procedure. CONCLUSION: Our findings suggest that ultrasound is a valid imaging modality to perform lumbar medial branch cryoneurolysis. Initial results show that cryoneurolysis under ultrasound guidance appears as a safe and effective procedure in patients suffering for facet joint pain.

Innovative Spine Implants for Improved Augmentation and Stability in Neoplastic Vertebral Compression Fracture.

Background and objectives: Tumor-related vertebral compression fractures often result in severe back pain as well as progressive neurologic impairment and additional morbidities. The fixation of these fractures is essential to obtain good pain relief and to improve the patients' quality of life. Thus far, several spine implants have been developed and studied. The aims of this review were to describe the implants and the techniques proposed to treat cancer-related vertebral compression fractures and to compile their safety and efficacy results. Materials and Methods: A systematic MEDLINE/PubMed literature search was performed, time period included articles published between January 2000 and March 2019. Original articles were selected based on their clinical relevance. Results: Four studies of interest and other cited references were analyzed. These studies reported significant pain and function improvement as well as kyphotic angle and vertebral height restoration and maintain for every implant and technique investigated. Conclusions: Although good clinical performance is reported on these devices, the small numbers of studies and patients investigated draw the need for further larger evaluation before drawing a definitive treatment decision tree to guide physicians managing patients presenting with neoplastic vertebral compression fracture.

Symptomatic Schmorl's nodes: role of percutaneous vertebroplasty. Open study on 52 patients.

PURPOSE: To assess the feasibility and clinical outcome of combined CT and fluoroscopy-guided percutaneous vertebroplasty in the management of painful Schmorl's nodes (SN). METHODS: A prospective study was carried out from January 2014 to January 2016 in 52 consecutive patients. Thirty-two men and 30 women aged between 42 and 88 years old were consecutively included. Technical success was defined as the ability to deposit cement in the subchondral endplate anteriorly, around the SN and posteriorly to the SN, in a cupule-like shape. Data regarding procedure time, amount of cement injection, and cement leakage were also noted. Assessment of pain was performed with VAS score and Oswestry disability index. All patients underwent a clinical and radiological follow-up at 1 day, 1 month, 6 months, and 1 year after procedure. RESULTS: Technical success was 100%. Mean procedural time was 15 min, and mean injected cement volume was 2.8 mL. The VAS and Oswestry disability index decreased respectively from 7.2 ± 1.5 to 2.1 ± 1.0 and from 59.2 ± 16.2 to 17.1 ± 5.0 at 1 month. Follow-up mean VAS scores were 2.4 (± 1.4) at 6 months and 2.2 (± 1.2) at 12 months. CONCLUSION: PVP appears as a feasible procedure in patients with painful SN with satisfying pain decrease in the following year after procedure.

Improving liver lesion characterisation using retrospective fusion of FDG PET/CT and MRI.

AIM: To compare retrospectively fused FDG PET/CT and MRI (PET/MRI) to FDG PET/CT and MRI for characterisation of indeterminate focal liver lesions as malignant or benign in patients with a known primary malignancy. MATERIALS AND METHOD: A retrospective review of 70 patients (30 females, 40 males; mean age 56 ±â€¯14 years) with 150 indeterminate lesions after FDG PET/CT and MRI (mean scan time interval 21 ±â€¯11 days). HERMES® software was used to fuse PET/CT and MRI scans which were reviewed by 2 readers using the Likert score (scale 1-5) to characterise lesions as benign (1-3) or malignant (4-5). Final diagnosis was determined by histopathology or follow up imaging. Results for fused PET/MRI were compared to PET/CT and MRI alone. RESULTS: For detection, MRI and fused PET/MRI detected all the lesions while PET/CT detected 89.4%. Characterisation of liver lesions as malignant on PET/CT alone yielded sensitivity, specificity, accuracy, PPV and NPV of 55.6%, 83.3%, 66.7%, 83.3%, 55.6% respectively and 67.6%, 92.1%, 80%, 89.3%, 74.5% for MRI, respectively. The sensitivity, specificity, accuracy, PPV and NPV for characterising lesions as malignant increased to 91.9%, 97.4%, 94.7%, 97.1%, 92.5% with PET/MRI fusion. The sensitivity, specificity, accuracy, PPV and NPV of fused PET/MRI for characterising lesions as malignant remained superior to PET/CT and MRI. CONCLUSION: Retrospective fusion of PET with MRI has improved characterisation of indeterminate focal liver lesions compared to MRI or FDG PET/CT alone.

Facet joint syndrome: from diagnosis to interventional management.

Low back pain (LBP) is the most common pain syndrome, and is an enormous burden and cost generator for society. Lumbar facet joints (FJ) constitute a common source of pain, accounting for 15-45% of LBP. Facet joint degenerative osteoarthritis is the most frequent form of facet joint pain. History and physical examination may suggest but not confirm facet joint syndrome. Although imaging (radiographs, MRI, CT, SPECT) for back pain syndrome is very commonly performed, there are no effective correlations between clinical symptoms and degenerative spinal changes. Diagnostic positive facet joint block can indicate facet joints as the source of chronic spinal pain. These patients may benefit from specific interventions to eliminate facet joint pain such as neurolysis, by radiofrequency or cryoablation. The purpose of this review is to describe the anatomy, epidemiology, clinical presentation, and radiologic findings of facet joint syndrome. Specific interventional facet joint management will also be described in detail. TEACHING POINTS: • Lumbar facet joints constitute a common source of pain accounting of 15-45%. • Facet arthrosis is the most frequent form of facet pathology. • There are no effective correlations between clinical symptoms, physical examination and degenerative spinal changes. • Diagnostic positive facet joint block can indicate facet joints as the source of pain. • After selection processing, patients may benefit from facet joint neurolysis, notably by radiofrequency or cryoablation.

Ultrasound Assessment of Ice-Ball Formation by Cryoneurolysis Device in an Ex Vivo Model.

BACKGROUND AND OBJECTIVES: Real-time ice-ball formation during cryoneurolysis has sparsely been assessed with ultrasound (US). Cryoneurolysis in lower back pain syndrome represents a validated management option in cases of facet joint syndrome. Ultrasound may be a useful tool to perform facet joint cryodenervation. The objective of this study was to assess, ex vivo, the ability of US to assess the ice-ball formation of a cryoneurolysis device. METHODS: Ultrasound assessment of the ice-ball depiction was done using chicken muscle at 22°C in which several freezing cycles were performed with both 2.1- and 1.3-mm cryoprobes. For each freezing cycle, static images and dynamic videos were generated for both needle insertion and ice-ball formation with 18-, 11-, and 6-MHz transducers. The following data were assessed in each combination of cryoprobe and transducers: quality of needle tip visualization, quality of the ice-ball formation depiction, size of the ice ball, presence of a shadow cone, and usefulness of power Doppler mode to assess ice-ball formation. RESULTS: The 18- and 11-MHz linear transducers allowed to directly depict the formation of the ice ball. Visualization of the cone shadowing allowed indirect visualization of the ice ball with both 18- and 11-MHz transducers. However, the ice ball was not depicted (directly or indirectly) with the convex 6-MHz transducer, and power Doppler was the only way to indirectly monitor the ice ball during the freezing cycles. CONCLUSIONS: Ultrasound is a useful tool to monitor the formation of ice ball during a cryoneurolysis freezing cycle. Power Doppler appears as the only option to monitor the ice ball with low-frequency transducers. This novel finding may be useful in cases of lumbar medial branch cryoneurolysis, an application we plan to assess in a future pilot prospective study.

Facial nerve tractography: A new tool for the detection of perineural spread in parotid cancers.

OBJECTIVES: To determine whether facial nerve MR tractography is useful in detecting PeriNeural Spread in parotid cancers. METHODS: Forty-five participants were enrolled. Thirty patients with surgically managed parotid tumors (15 malignant, 15 benign) were compared with 15 healthy volunteers. All of them had undergone 3T-MRI with diffusion acquisition and post-processing constrained spherical deconvolution-based tractography. Parameters of diffusion-weighted sequences were b-value 1,000 s/mm2, 32 directions. Two radiologists performed a blinded visual reading of tractographic maps and graded the facial nerve average pathlength and fractional anisotropy (FA). We also compared diagnostic accuracy of tractography with morphological MRI sequences to detect PeriNeural Spread. Non-parametric methods were used. RESULTS: Average pathlength was significantly higher in cases with PeriNeural Spread (39.86 mm [Quartile1: 36.27; Quartile3: 51.19]) versus cases without (16.23 mm [12.90; 24.90]), p<0.001. The threshold above which there was a significant association with PeriNeural Spread was set at 27.36 mm (Se: 100%; Sp: 84%; AUC: 0.96, 95% CI 0.904-1). There were no significant differences in FA between groups. Tractography map visual analyses directly displayed PeriNeural Spread in distal neural ramifications with sensitivity of 75%, versus 50% using morphological sequences. CONCLUSIONS: Tractography could be used to identify facial nerve PeriNeural Spread by parotid cancers. KEY POINTS: • Tractography could detect facial nerve PeriNeural Spread in parotid cancers. • The average pathlength parameter is increased in case of PeriNeural Spread. • Tractography could map PeriNeural Spread more precisely than conventional imaging.

Dual Site Pudendal Nerve Infiltration: More than Just a Diagnostic Test?

BACKGROUND: Pudendal neuralgia (PN) is a very painful and often disabling condition in which pudendal nerve blocks play an important role in both the diagnosis and management of PN. Some previous reports have advocated the use of pudendal nerve infiltration (PNI) as a diagnostic test only. OBJECTIVE: We aim to assess the outcomes of patients with typical refractory PN who underwent dual site computed tomography (CT)-guided pudendal nerve infiltration. STUDY DESIGN: A bicentric, retrospective cohort analysis. SETTING: An academic practice. METHODS: Between 2002 and 2016, 385 PNIs were performed in 195 patients in the 2 units. Only patients suffering from typical clinical PN were included, and only the first infiltration in each patient was considered for analysis. Therefore, 95 patients who underwent 155 procedures were assessed. Pain was assessed using a visual analog scale (0-10) and self-reported estimated improvement (SRI), expressed as a percentage. Efficacy of the procedure was assessed at 1, 3, and 6 months after procedure follow-up, and clinical success was defined as a 50% decrease of the VAS score. All procedures were performed under CT guidance and on an outpatient basis. Dual site infiltration was performed in each case at both the ischial spine and intra-Alcock's canal sites using a mixture of fast- and slow-acting anesthetic (1 mL lidocaine hydrochloride 1% and 2 mL ropivacaine chlorhydrate) along with a half dose of 1.5 mL of cortivazol (3.75 mg). RESULTS: Clinical success at one month post-procedure was present in 63.2% of patients (60/95) with a mean VAS score of 2.07 (P < 0.05) and a mean SRI of 71%. At 3 months follow-up, clinical success was still present in 50.5% of patients (48/95) with a mean VAS score of 2.90/10 (P < 0.05) and a mean SRI of 62.3%. At 6 months follow-up, the efficacy rate decreased to 25.2% with a mean VAS score of 3.2/10 and SRI of 60%. LIMITATIONS: The retrospective aspect of the study is a limitation, as well as the lack of a control group. CONCLUSION: Dual site PNI under CT guidance may offer significant mid-term pain relief to a majority of patients suffering from typical refractory PN. KEY WORDS: Pudendal nerve, neuralgia, block, Alcock, CT, guidance.

Greater occipital nerve cryoneurolysis in the management of intractable occipital neuralgia.

OBJECTIVE: To assess technical feasibility of cryoneurolysis of the greater occipital nerve in the management of occipital neuralgia. METHODS: Six patients suffering from unilateral refractory greater occipital neuralgia and who underwent 7 GON cryoneurolysis were assessed between October 2015 and January 2017. All procedures were performed under CT guidance and local anesthesia. A planning CT was performed with contrast enhancement to plan needle target and identify surrounding major vascular structures. A 12G coaxial needle (Inomed) was then inserted and targeted the first bend of the GON under and lateral to the obliquus capitis inferior muscle. A 2.0mm cryoprobe was then inserted in the coaxial and sensitive stimulation at 100Hz was performed. One to three freezing cycles were performed in one session. RESULTS: Technical feasibility was 100% as cryoneurolysis could be performed in all 7 cases with accurate sensitive nerve stimulation prior to freezing cycle. One patient benefited from a second session after failure of the first session. More than 50% pain reduction was achieved at day 7 in all cases, and 5 of 6 cases at one and three months follow-up. CONCLUSION: Cryoneurolysis of the GON in the management of refractory GON neuralgia is feasible. Initial results are promising as 5/7 cases benefited from a 3-month pain alleviation period.