Percutaneous Imaging-guided Cryoablation of Endometriosis Scars of the Anterior Abdominal Wall.

STUDY OBJECTIVE: To evaluate the safety and clinical efficacy of percutaneous imaging-guided cryoablation for the management of anterior abdominal wall endometriosis. DESIGN: Patients with abdominal wall endometriosis underwent percutaneous imaging-guided cryoablation and had a 6-month follow-up. SETTING: Data dealing with patients' and anterior abdominal wall endometriosis (AAWE) characteristics, cryoablation, and clinical and radiologic outcomes were retrospectively collected and analyzed. PATIENTS: Twenty-nine consecutive patients underwent cryoablation from June 2020 to September 2022. INTERVENTIONS: Interventions were performed under US/computed tomography (CT) guidance or magnetic resonance imaging (MRI) guidance. Cryoprobes were directly inserted into the AAWE, and cryoablation was performed with a single 5 to 10 minute freezing cycle, which was stopped when the iceball expanded 3 to 5 mm beyond AAWE borders as assessed on intra-procedural cross-sectional imaging. MEASUREMENTS AND MAIN RESULTS: Fifteen patients (15/29; 51.7%) had prior endometriosis, 28 (28/29; 95.5%) had previous cesarian section, and 22 (22/29; 75.9%) referred association between symptoms and menses. Cryoablation was performed under local (16/29; 55.2%) or general anesthesia (13/29; 44.8%) and mainly in an out-patient basis (18/20; 62%). There was only one (1/29; 3.5%) minor procedure-related complication. Complete symptom relief was recorded in 62.1% (18/29) and 72.4% (21/29) patients at 1 and 6 months, respectively. In the whole population, pain significantly dropped at 6 months compared to the baseline (1.1 ± 2.3; range 0-8 vs 7.1 ± 1.9; range 3-10; p <.05). Eight (8/29; 27.6%) patients presented residual symptoms at 6 months, and 4 (4/29; 13.8%) had an MRI-confirmed residual/recurring disease. Contrast-enhanced MRI obtained for the first 14 (14/29; 48.3%) patients of the series, all without signs of residual/recurring disease, demonstrated a significantly smaller ablation area compared to the baseline volume of the AAWE (1.0 cm3 ± 1.4; range 0-4.7; vs 11.1 ± 9.9 cm3; range 0.6-36.4; p <.05). CONCLUSION: Percutaneous imaging-guided cryoablation of AAWE is safe and clinically effective in achieving pain relief.

Percutaneous image-guided cryoablation of spinal metastases: over 10-year experience in two academic centers.

OBJECTIVES: To report on safety and clinical effectiveness of cryoablation for the treatment of spinal metastases (SM) in patients needing pain palliation or local tumor control (LTC). METHODS: All consecutive patients with SM who underwent cryoablation from May 2008 to September 2020 in two academic centers were retrospectively identified and included in the present analysis. Patient characteristics, goal of treatment (curative/palliative), SM characteristics, procedural details, and clinical outcomes (pain relief; local tumor control [LTC]) were analyzed. RESULTS: There were 74 patients (35 women; median age 61 years) accounting for 105 SM. Additional cementoplasty was used for 76 SM (76/105; 72.4%). There were 9 complications (out of 105 SM [8.5%]; 2 major and 7 minor) in 8 patients. Among the 64 (64/74; 86.5%) patients with painful SM, the mean Numerical Pain Rating Scale dropped from 6.8 ± 2.2 (range, 0-10) at the baseline to 4.1 ± 2.4 (range, 0-9; p < 0.0001) at 24 h, 2.5 ± 2.6 (range, 0-9; p < 0.0001) at 1 month, and 2.4 ± 2.5 (range, 0-9; p < 0.0001) at the last available follow-up (mean 14.7 ± 19.6 months; median 6). Thirty-four patients (34/64; 53.1%) were completely pain-free at the last follow-up. At mean 25.9 ± 21.2 months (median 16.5) of follow-up, LTC was achieved in 23/28 (82.1%) SM in 21 patients undergoing cryoablation with curative intent. CONCLUSION: Cryoablation of SM, often performed in combination with vertebral augmentation, is safe, achieves fast and sustained pain relief, and provides high rates of LTC at mean 2-year follow-up. KEY POINTS: •Cryoablation of spinal metastases is safe. •Cryoablation of spinal metastases allows rapid and sustained pain relief. •The mean 2-year rate of local tumor control after cryoablation of spinal metastases is 82.1%.

The changing trends of image-guided biopsy of small renal masses before intervention-an analysis of European multinational prospective EuRECA registry.

OBJECTIVES: To evaluate the use of pre-cryoablation biopsy for small renal masses (SRMs) and the effects of increasing uptake on histological results of treated SRMs. METHODS: From 2015 to 2019, patients with sporadic T1N0M0 SRMs undergoing percutaneous, laparoscopic, or open cryoablation from 14 European institutions within the European Registry for Renal Cryoablation (EuRECA) were included for the retrospective analysis. Univariate and multivariate logistic models were used to evaluate the trends, histological results, and the factors influencing use of pre-cryoablation biopsy. RESULTS: In total, 871 patients (median (IQR) age, 69 (14), 298 women) undergoing cryoablation were evaluated. The use of pre-cryoablation biopsy has significantly increased from 42% (65/156) in 2015 to 72% (88/122) in 2019 (p < 0.001). Patients treated for a benign histology are significantly more likely to have presented later in the trend, where pre-cryoablation biopsy is more prevalent (OR: 0.64, 95% CI 0.51-0.81, p < 0.001). Patients treated for undiagnosed histology are also significantly less likely to have presented in 2018 compared to 2016 (OR 0.31, 95% CI 0.10-0.97, p = 0.044). Patients aged 70+ are less likely to be biopsies pre-cryoablation (p < 0.05). R.E.N.A.L. nephrometry score of 10+ and a Charlson Comorbidity Index > 1 are factors associated with lower likelihood to not have received a pre-cryoablation biopsy (p < 0.05). CONCLUSION: An increased use of pre-cryoablation biopsy was observed and cryoablation patients treated with a benign histology are more likely to have presented in periods where pre-cryoablation biopsy is not as prevalent. Comparative studies are needed to draw definitive conclusions on the effect of pre-cryoablation biopsy on SRM treatments. KEY POINTS: • The use of biopsy pre-ablation session has increased significantly from 42% of all patients in 2015 to 74% in 2019. • Patients are less likely to be treated for a benign tumour if they presented later in the trend, where pre-cryoablation biopsy is more prevalent, compared to later in the trend (OR 0.64, 95% CI 0.51-0.81, p < 0.001). • Patients with comorbidities or a complex tumour (R.E.N.A.L. nephrometry score > 10) are less likely to not undergo biopsy as a separate session to cryoablation.

Safety and Efficacy of Percutaneous Cryoablation of Extraspinal Thyroid Cancer Bone Metastases with Curative Intent: Single-Center Experience with a Median Follow-up of More than 5 Years.

PURPOSE: To determine the oncologic outcomes and safety profile of image-guided percutaneous cryoablation (PCA) for extraspinal thyroid cancer bone metastases with curative intent. MATERIALS AND METHODS: Between January 2010 and January 2020, 16 consecutive patients (8 men, 8 women; mean age, 61 years ± 19; range, 30-84 years) with 18 bone metastases (median bone tumor size, 19 mm; interquartile range [IQR], 12-29 mm; range, 7-58 mm) underwent PCA of oligometastatic extraspinal bone metastases. Thirteen (81%) patients were radioiodine therapy resistant. Two patients underwent 2 bone tumor ablations in a single session. Procedural data, oncologic outcomes, follow-up (with magnetic resonance imaging and positron emission tomography-computed tomography), and adverse events were retrospectively investigated. Local tumor progression-free survival, disease-free survival, and overall survival were estimated using the Kaplan-Meier method. RESULTS: A median of 2 cryoprobes (IQR, 1.25-3 cryoprobes; range, 1-7 cryoprobes) were used, with 2 freezing cycles; the median length of freezing was 20 minutes (IQR, 17-20 minutes; range, 10-20 minutes). The technical success was 100% (18/18), and the primary technical efficacy was 94.4% (17/18). The median follow-up was 68 months (IQR, 38-93 months). During follow-up, 3 of 17 (17.6%) tumors demonstrated local progression at 7, 13, and 27 months. Consequently, the 1-, 2-, 3-, 4-, and 5-year local tumor progression-free survivals were 93.3%, 84.6%, 76.9%, 75%, and 72.7%, respectively. Two of 16 (12.5%) patients died during follow-up at 43 and 88 months. The major adverse event rate was 5.5% (1/18) with 1 postablative acromion fracture. CONCLUSIONS: PCA for extraspinal thyroid cancer bone metastases demonstrated high local tumor control rates with a safe profile at long-term follow-up.

Comprehensive Palliative Musculoskeletal Interventional Radiology Care for Patients with Cancer.

Substantial advances in percutaneous image-guided minimally invasive musculoskeletal oncologic interventions offer a robust armamentarium for interventional radiologists for management of cancer. The authors outline the most recent advances in such interventions and the role of interventional radiologists in managing cancer in modern-era practice. Percutaneous minimally invasive musculoskeletal interventions including thermal ablation, cementation with or without osseous reinforcement by implants, osteosynthesis, neurolysis, and embolization, as well as palliative injections, have been successfully used by interventional radiologists to achieve durable, timely, safe, effective palliation in a multidisciplinary setting and have been progressively incorporated into the management paradigm for patients with cancer with musculoskeletal involvement. Familiarity with the described interventions and implementation of procedural safety measures, combined with integration of these procedures into clinical practice with the support of the National Comprehensive Cancer Network and the American College of Radiology, as well as continued technologic advances in procedural equipment design, will further enhance the role of interventional radiologists in cancer management. ©RSNA, 2022.

Percutaneous vertebroplasty of the cervical spine performed via a posterior trans-pedicular approach.

OBJECTIVES: Percutaneous vertebroplasty (PV) of the cervical spine has been traditionally performed with a trans-oral or antero-lateral approach. The posterior trans-pedicular approach (PTPA) has been sporadically reported. Therefore, the aim of this study is to retrospectively assess the technical feasibility, safety, and clinical outcomes of cervical PV performed with a PTPA. METHODS: All consecutive patients undergoing PV in cervical levels with PTPA (under general anesthesia and computed tomography [CT] guidance) from January 2008 to November 2019 were identified. The following data were collected: patients' demographics; indication for PV; vertebral level features; procedure-related variables; and clinical outcomes including complications and pain relief. RESULTS: Thirty-two patients (18 females, 14 males; mean age 61.1 ± 13.2 years, range 36-88) were included accounting for 36 vertebrae. Three vertebrae (3/36, 8%) were referred due to an underlying traumatic fracture, the remaining (33/36, 92%) due to a painful lytic tumor. Technical success was 97% (35/36 levels). Mean time required to deploy the trocar was 23 ± 11 min (range 7-60). Extra-vertebral asymptomatic cement leakage was observed in 3/35 (9%) vertebral levels. One patient (1/32, 3%) developed an acute cardiogenic pulmonary edema requiring admission in the intensive care unit; another patient (1/32, 3%) developed localized infection to the skin entry site, which was managed conservatively. At 1-month follow-up, the mean pain in the study population was 1.0 ± 1.1 (range 0-4/10) vs 6.2 ± 1.4 (range 4-9/10) at baseline (p < 0.05). CONCLUSIONS: Cervical PV performed via a CT-guided PTPA is technically feasible, safe, and results in effective pain relief. KEY POINTS: • Percutaneous vertebroplasty (PV) is a well-established technique for the treatment of benign and malignant compression fractures. • Common PV approaches used for cervical vertebrae include the trans-oral, antero-lateral, lateral, and sporadically the posterior trans-pedicular approach. • Retrospective analysis of our 11-year experience with the posterior trans-pedicular approach used for cervical vertebrae proved that such approach was safe and effective.

Vertebral augmentation reduces the 12-month mortality and morbidity in patients with osteoporotic vertebral compression fractures.

OBJECTIVES: To investigate the 12-month all-cause mortality and morbidity in patients with osteoporotic vertebral compression fractures (OVCFs) undergoing vertebroplasty/balloon kyphoplasty (VP/BKP) versus non-surgical management (NSM). METHODS: Following a Medline and EMBASE search for English language articles published from 2010 to 2019, 19 studies reporting on mortality and morbidity after VP/BKP in patients with OVCFs were selected. The 12-month timeline was set due to the largest amount of data availability at such time interval. Estimates for each study were reported as odds ratios (OR) along with 95% confidence intervals (CI) and p values. Fixed or random-effects meta-analyses were performed. All tests were based on a two-sided significance level of 0.05. RESULTS: Pooled OR across 5 studies favored VP/BKP over NSM in terms of 12-month all-cause mortality (OR: 0.81 [95% CI: 0.46-1.42]; p = .46). Pooled OR across 11 studies favored VP/BKP over NSM in terms of 12-month all-cause morbidity (OR: 0.64 [95% CI: 0.31-1.30]; p = .25). Sub-analysis of data dealing with 12-month infective morbidity from any origin confirmed the benefit of VP/BKP over NSM (OR: 0.23 [95% CI, 0.02-2.54]; p = .23). CONCLUSION: Compared to NSM, VP/BKP reduces the 12-month risk of all-cause mortality and morbidity by 19% and 36%, respectively. Moreover, VP/BKP reduces by 77% the 12-month risk of infection from any origin. KEY POINTS: • Compared to non-surgical management, vertebral augmentation reduces the 12-month risk of all-cause mortality by 19% and all-cause morbidity by 36%. • Vertebral augmentation reduces the 12-month risk of infection morbidity from any origin by 77%.

Percutaneous microwave ablation of bone tumors: a systematic review.

AIM: To systematically review microwave ablation (MWA) protocols, safety, and clinical efficacy for treating bone tumors. MATERIALS AND METHODS: A systematic literature search was conducted using PubMed, the Cochrane Library, EMBASE, and Web of Science database. Data concerning patient demographics, tumor characteristics, procedure, complications, and clinical outcomes were extracted and analyzed. RESULTS: Seven non-comparative studies (6 retrospective, 1 prospective) were included accounting for 249 patients and 306 tumors (244/306 [79.7%] metastases; 25/306 [8.2%] myelomas, and 37/306 [12.1%] osteoid osteomas [OO]). In malignant tumors, MWA power was 30-70 W (except in one spinal tumors series where a mean power of 13.3 W was used) with pooled mean ablation time of 308.3 s. With OO, MWA power was 30-60 W with mean ablation time of 90-102 s. Protective measures were very sporadically used in 5 studies. Additional osteoplasty was performed in 199/269 (74.0%) malignant tumors. Clinically significant complications were noted in 10/249 (4.0%) patients. For malignant tumors, estimated pain reduction on the numerical rating scale was 5.3/10 (95% confidence intervals [95%CI] 4.6-6.1) at 1 month; and 5.3/10 (95% CI 4.3-6.3) at the last recorded follow-up (range 20-24 weeks in 4/5 studies). For OO, at 1-month follow-up, effective pain relief was noted in 92.3-100% of patients. CONCLUSION: MWA is effective in achieving pain relief at short- (1 month) and mid-term (4-6 months) for painful OO and malignant bone tumors, respectively. Although MWA seems safe, further prospective studies are warranted to further assess this aspect, and to standardize MWA protocols. KEY POINTS: • Large heterogeneity exists across literature about ablation protocols used with microwave ablation applied for the treatment of benign and malignant bone tumors. • Although microwave ablation of bone tumors appears safe, further studies are needed to assess this aspect, as current literature does not allow definitive conclusions. • Nevertheless, microwave ablation is effective in achieving pain relief at short- (1 month) and mid-term (4-6 months) for painful osteoid osteomas and malignant bone tumors, respectively.

Diagnostic accuracy and safety of percutaneous MRI-guided biopsy of solid renal masses: single-center results after 4.5 years.

OBJECTIVES: To retrospectively evaluate diagnostic accuracy and complications of magnetic resonance imaging (MRI)-guided biopsy of radiologically indeterminate solid renal masses (RM). METHODS: Electronic records of all consecutive patients undergoing MRI-guided biopsy of solid RM (using free-breathing T2-BLADE and BEAT-IRTTT sequences) between April 2014 and October 2018 were reviewed; 101 patients (69 men, 32 women; median age 68 years; range 32-76) were included. Patient and RM characteristics, procedural details/complications, pathologic diagnosis, and clinical management were recorded. Diagnostic accuracy was calculated on an intention-to-diagnose basis. Diagnostic yield was also evaluated. Multi-variable analysis was performed for variables with p < .20, including patient age/sex; RM size/location/contact with vascular pedicle, RENAL score, number and total length of biopsy samples, and biopsy tract embolization, to determine factors associated with diagnostic samples, diagnostic accuracy, and complications. RESULTS: Median RM size was 2.4 cm (range 1-8.4 cm). There were 86 (85%; 95%CI 77-91%) diagnostic and 15 (15%; 95%CI 9-23%) non-diagnostic samples; 6/15 (40%) non-diagnostic biopsies were repeated with 50% malignancy rate. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 96% (95%CI 89-99%), 100% (95%CI 77-100%), 100% (95%CI 95-100%), 82% (95%CI 57-96%), and 97% (95%CI 90-99%), respectively. Primary and secondary diagnostic yields were 85% (95%CI 77-91%) and 91% (95%CI 84-96%), respectively. Seven (7%; 95%CI 1-10%) complications were observed. No tested variables were associated with diagnostic samples, diagnostic accuracy, or complications. CONCLUSIONS: MRI-guided biopsy of solid RM is associated with high diagnostic accuracy and low complication rate. The technique might be helpful for inaccessible tumors. KEY POINTS: • MRI-guided biopsy of radiologically indeterminate solid renal masses (RM) appears safe, with a low rate of minor self-limiting hemorrhagic complications. • Diagnostic accuracy and primary/secondary diagnostic yield are high and appear similar to reported estimates for US- and CT-guided RM biopsy. • MRI guidance may be particularly useful for RM with poor conspicuity on US and CT, for relatively inaccessible tumors (e.g., tumors requiring double-oblique steep-angled approaches), and for young patients or those with renal failure.

Freezing Nodal Disease: Local Control Following Percutaneous Image-Guided Cryoablation of Locoregional and Distant Lymph Node Oligometastases: A 10-Year, Single-Center Experience.

PURPOSE: To retrospectively assess the technical feasibility, safety, and oncologic outcomes of percutaneous image-guided cryoablation (PCA) of locoregional and distant lymph node metastases (LNMs). METHODS: All consecutive patients undergoing PCA of LNMs between February 2009 and December 2019 were identified using a retrospective database search. Every patient was followed up at 1, 3, 6, and 12 months after treatment using contrast-enhanced magnetic resonance imaging and at approximately 3-6-month intervals using computed tomography or positron emission tomography-computed tomography. The Kaplan-Meier method was used to calculate local tumor progression-free survival, disease-free survival, and overall survival. Locoregional and distant groups were compared using the Fisher test. Technical success, technique efficacy, complications, and oncologic outcomes were analyzed. RESULTS: Fifty-six metachronous oligometastatic LNMs (median size, 15 mm [interquartile range, 13-15 mm; range, 9-36 mm]) were treated in 37 sessions in 29 patients and defined as locoregional (26/37 sessions) or distant (11/37 sessions). Seventeen patients had undergone prior surgery or radiotherapy. Six patients underwent 8 retreatments for locoregional progression. An additional visceral oligometastasis was treated in 4 of the 11 distant LNM PCA sessions. The technical success and primary technique efficacy rates were 100%. The complication rate was 5.4% (2 transient nerve palsies). At a median follow-up of 23 months, there were 2 instances of local tumor progression (5.6%); the 1-, 2-, and 3-year local tumor progression-free survival was 100%, 94.3%, and 94.3%, respectively. Thirteen (45%) patients demonstrated no disease progression. The 1-, 2-, and 3-year overall survival was 96.2%, 90.5%, and 70%, respectively. The patients were free from systemic oncologic therapy following 20 (54%) sessions, with a mean treatment break of 19.1 months. CONCLUSIONS: The PCA of lymph node oligometastases is feasible and safe, and offers promising local tumor control at midterm follow-up.

Percutaneous cryoablation for advanced and refractory extra-abdominal desmoid tumors.

PURPOSE: To assess efficacy and safety of percutaneous cryoablation (CA) for advanced and refractory extra-abdominal desmoid tumors. MATERIALS AND METHODS: This retrospective study reviewed 30 consecutive patients with symptomatic desmoid tumors evolving after "wait and watch" periods, and despite medical treatment, treated by CA between 2007 and 2019. Progression free survival (PFS), objective response rate, pain reduction (decreased of visual analogic scale pain (VAS)[Formula: see text] 3 or disappearance of pain), total volume lesion (TVL) and complications were documented. Kaplan Meier method was used to outline PFS. Paired sample t test was used to compare volume of tumors before treatment and at 1 and 3 year. RESULTS: With a median follow-up of 18.5 months (range 6-93 months, interquartile range (IQR): 12-55), the PFS was 85.1% at 1 year and 77.3% at 3 years. Objective response was obtained for 80% of patients with a complete response for 43% patients. Pain reduction was obtained for 96.7% (95% confidence interval (95% CI): 90.3, 100) of patients. Median volume of desmoid tumor before treatment was 124.1cm3 (range 2-1727cm3, IQR: 54-338cm3). Median change of TLV after ablation was 66.6% (95% CI: 37.2, 72.3; p = 0.002) at 1 year and 76.4% (95% CI: 59.1, 89.8; p = 0.002) at 3 year. Adverse events rate was 36.6%, the most common was edema and temporary increase of pain in the days following CA. Four patients experienced a major complication (13.3%): 2 skin necrosis, 1 infection and 1 brachial plexopathy. CONCLUSION: CA is an effective treatment for advanced and refractory extra-abdominal desmoid tumor, that induces durable responses.

Accuracy and technical limits of percutaneous pedicle screw placement in the thoracolumbar spine.

PURPOSE: The two-dimensional fluoroscopic method of percutaneous pedicle screw instrumentation has been clinically described as reliable method in the caudal thoracic and lumbosacral spine. Its accuracy has not been clearly reported in the cranial thoracic spine. The aim of this in vitro study was to investigate percutaneous pedicle screw placement accuracy according to pedicle dimensions and vertebral levels. METHODS: Six fresh-frozen human specimens were instrumented with 216 screws from T1 to S1. Pedicle isthmus widths, heights, transversal pedicles and screws were measured on computed tomography. Pedicle cortex violation ≥ 2 mm was defined as screw malposition. RESULTS: The narrowest pedicles were at T3-T5. A large variability between transversal pedicle axes and percutaneous pedicle screw was present, depending on the spinal level. Screw malposition rates were 36.1% in the cranial thoracic spine (T1-T6), 16.7% in the caudal thoracic spine (T7-T12), and 6.9% in the lumbosacral spine (L1-S1). The risk for screw malposition was significantly higher at cranial thoracic levels compared to caudal thoracic (p = 0.006) and lumbosacral (p < 0.0001) levels. Cortex violation ≥ 2 mm was constantly present if the pedicle width was < 4.8 mm. CONCLUSION: Percutaneous pedicle screw placement appears safe in the caudal thoracic and lumbosacral spine. The two-dimensional fluoroscopic method has a limited reliability above T7 because of smaller pedicle dimensions, difficulties in visualizing radiographic pedicle landmarks and kyphosis.

Complications Following Percutaneous Image-guided Radiofrequency Ablation of Bone Tumors: A 10-year Dual-Center Experience.

Background Percutaneous radiofrequency ablation (RFA) is effective in the management of bone tumors. However, knowledge of the complication rate and risk factors for complications of RFA is lacking. Purpose To report the complication rate and risk factors of bone tumor RFA. Materials and Methods This retrospective study reviewed complications in consecutive patients who underwent RFA of primary or metastatic bone tumors from January 2008 to April 2018. Complications were categorized into major (grade 3 or 4, severe or life-threatening) or minor (grade 1 or 2, mild or moderate) according to Common Terminology Criteria for Adverse Events. Univariable and multivariable regression analyses were performed to identify variables associated with complications of RFA. Results A total of 169 patients (median age, 63 years; interquartile range, 55-73 years; 85 men) with 217 tumors were evaluated. The total complication rate was 30.0% (65 of 217; 95% confidence interval [CI]: 23.8%, 36.0%). The major complication rate was 2.3% (five of 217; 95% CI: 0.8%, 5.3%), with secondary fracture being the most frequent event (1.8% [four of 217]). The minor complication rate was 27.7% (60 of 217; 95% CI: 21.7%, 33.6%), with immediate postoperative pain being the most frequent event (18.0% [39 of 217]). Risk factors for all complications included tumor size greater than 3 cm (adjusted odds ratio [AOR], 2.4 [95% CI: 1.2, 4.5]; P = .03) and previous radiation therapy (AOR, 3.8 [95% CI: 2.0, 7.4]; P = .02). The only risk factor for minor complications was previous radiation therapy (AOR, 2.2 [95% CI: 1.0, 4.7]; P = .04). Conclusion Bone tumor radiofrequency ablation is safe, with a low rate of major complications mainly consistent with secondary fractures. Risk factors for complications are tumor size greater than 3 cm and previous radiation therapy. © RSNA, 2020 Online supplemental material is available for this article.

Large nearly spherical ablation zones are achieved with simultaneous multi-antenna microwave ablation applied to treat liver tumours.

AIM: To investigate the shape and the volume of ablation zones obtained with microwave ablation (MWA) performed with multiple antennas in liver tumours. MATERIALS AND METHODS: Tumour volume, number of antennas, size (long diameter (Dl), along the antenna axis; short diameter (Ds), perpendicular to the antenna axis; vertical diameter (Dv), vertical to both Dl and Ds) and shape (roundness index (RI); 1 corresponds to a sphere) of the ablation zone, ablation volume, and complications were evaluated. RESULTS: Mean Dl, Ds, and Dv were 4.7 ± 1.4 cm, 3.9 ± 1.4 cm, and 3.8 ± 1.0 cm, respectively. Mean RIs (Ds/Dl, Dv/Dl, and Dv/Ds) were 0.83 ± 0.13, 0.83 ± 0.17, and 1.02 ± 0.23, respectively, without any difference between the mean RI obtained with the double (0.84 ± 0.01) and that with the triple-antenna (0.93 ± 0.13) approach (p = 0.25). Mean ablation volume was 41 ± 32 cm3 (vs. mean tumour volume 13 ± 10 cm3; range 1-40; p < 0.001). No complications were noted. CONCLUSIONS: Simultaneous multi-antenna MWA of liver tumours results in large nearly spherical ablation zones. KEY POINTS: • Simultaneous multi-antenna microwave ablation of liver tumours results in nearly spherical ablation zones. • The multi-antenna approach generates oversized ablation volumes compared with the target tumour volume. • The multi-antenna approach is safe.

Percutaneous image-guided thermal ablation of bone metastases: a retrospective propensity study comparing the safety profile of radio-frequency ablation and cryo-ablation.

OBJECTIVES: To retrospectively compare the safety profile of percutaneous image-guided radiofrequency ablation (RFA) and cryoablation (CA) of bone metastases (BM) with and without a propensity score analysis. METHODS: Between January 2008 and April 2018, 274 consecutive patients (mean age 61.6 ± 12.1 years) with BM were treated at our Institution with RFA (53 patients; 66 BM) or CA (221 patients; 301 BM) and included in this study. Complications were assessed according to the type of ablation modality before and after applying a 1:1 propensity score method taking into account patient's demographics, BM features, procedural details and follow-up findings. RESULTS: In the whole 9 BM (2.5%) reported major complications without significant difference between RFA (1/66; 1.5%) and CA (8/301; 2.7%; p = 1); 40 BM (10.9%) showed minor complications, which were more common with RFA (22/66; 33.3%) than with CA (18/301; 6.0%, p<.001) mainly due to post-procedural pain occurring more frequently with RFA than CA (20/66; 30.3% vs. 7/301; 2.3%, p<.001). Following 1:1 matching, similar results were obtained, since there were similar rates of major complications with RFA and CA (1/66 [1.5%] and 0/66 [0.0%], respectively; p = 1); and higher rates of minor complications with RFA compared to CA [33.3% (22/66) vs. 2/66 (3%); p<.001] due to preponderant postprocedural pain (90.9% [20/22] minor complications with RFA). CONCLUSIONS: Similar low rates of major complications are expected with RFA and CA of BM. In the post-operative period, RFA appears more painful than CA, thus warranting for adoption of dedicated analgesic protocols for patients undergoing RFA.

Interventional Techniques for Bone and Musculoskeletal Soft Tissue Tumors: Current Practices and Future Directions - Part II. Stabilization.

Percutaneous image-guided oncologic interventions have rapidly evolved over the last two decades as an independent strategy or used within a first-, second-, or even third-line strategy in the treatment of musculoskeletal (MSK) tumors. Abundant mostly nonrandomized publications have described the safety, efficacy, and reproducibility of implementing percutaneous therapies both with curative and palliative intent. In this article, we continue to share our experience in bone and MSK soft tissue interventions focusing on stabilization and combined ablation and stabilization. We propose a pathway and explore future directions of image-guided interventional oncology related to skeletal disease. We reflect on the advantages and limitations of each technique and offer guidance and pearls to improve outcomes. Representing patterns from our practices, we demonstrate the role of collaborative working within a multidisciplinary team, ideally within a dedicated tumor treatment center, to deliver patient-specific therapy plans that are value based and favored by patients when given the choice.

French Multidisciplinary Approach for the Treatment of MSK Tumors.

Several interventional treatments have recently been integrated into the therapeutic armamentarium available for the treatment of bone tumors. In some scenarios (e.g., osteoid osteoma), interventional treatments represent the sole and definitive applied treatment. Due to the absence of widely shared protocols and the complex multivariate scenarios underlying the clinical presentation of the remaining bone tumors including metastases, therapeutic strategies derived from a multidisciplinary tumor board are essential to provide effective treatments tailored to each patient. In the present review, we present the multidisciplinary therapeutic strategies commonly adopted for the most frequent bone tumors.

Augmented reality and artificial intelligence-based navigation during percutaneous vertebroplasty: a pilot randomised clinical trial.

PURPOSE: To assess technical feasibility, accuracy, safety and patient radiation exposure of a novel navigational tool integrating augmented reality (AR) and artificial intelligence (AI), during percutaneous vertebroplasty of patients with vertebral compression fractures (VCFs). MATERIAL AND METHODS: This prospective parallel randomised open trial compared the trans-pedicular access phase of percutaneous vertebroplasty across two groups of 10 patients, electronically randomised, with symptomatic single-level VCFs. Trocar insertion was performed using AR/AI-guidance with motion compensation in Group A, and standard fluoroscopy in Group B. The primary endpoint was technical feasibility in Group A. Secondary outcomes included the comparison of Groups A and B in terms of accuracy of trocar placement (distance between planned/actual trajectory on sagittal/coronal fluoroscopic images); complications; time for trocar deployment; and radiation dose/fluoroscopy time. RESULTS: Technical feasibility in Group A was 100%. Accuracy in Group A was 1.68 ± 0.25 mm (skin entry point), and 1.02 ± 0.26 mm (trocar tip) in the sagittal plane, and 1.88 ± 0.28 mm (skin entry point) and 0.86 ± 0.17 mm (trocar tip) in the coronal plane, without any significant difference compared to Group B (p > 0.05). No complications were observed in the entire population. Time for trocar deployment was significantly longer in Group A (642 ± 210 s) than in Group B (336 ± 60 s; p = 0.001). Dose-area product and fluoroscopy time were significantly lower in Group A (182.6 ± 106.7 mGy cm2 and 5.2 ± 2.6 s) than in Group B (367.8 ± 184.7 mGy cm2 and 10.4 ± 4.1 s; p = 0.025 and 0.005), respectively. CONCLUSION: AR/AI-guided percutaneous vertebroplasty appears feasible, accurate and safe, and facilitates lower patient radiation exposure compared to standard fluoroscopic guidance. These slides can be retrieved under Electronic Supplementary Material.

Complications of Percutaneous Bone Tumor Cryoablation: A 10-year Experience.

Background Percutaneous cryoablation has been shown to be effective in the management of painful bone tumors. However, knowledge of the complication rate and risk factors for complication is currently lacking. Purpose To report the complication rate and associated risk factors for bone tumor cryoablation. Materials and Methods This retrospective study reviewed complications in 239 consecutive patients (131 men and 108 women; median age, 64 years; age range, 6-86 years) who underwent cryoablation of 320 primary or metastatic bone tumors between January 2008 and November 2017. Common Terminology Criteria for Adverse Events was used to categorize complications as major (grade 3-4) or minor (grade 1-2). Multivariable analysis was performed for variables with P values less than .20, including age, tumor location, adjacent critical structures, number of cryoprobes, and Eastern Cooperative Oncology Group performance status (ECOG-PS). Results Among the 320 tumors, the total complication rate was 9.1% (29 of 320; 95% confidence interval [CI]: 6%, 12.2%). The major complication rate was 2.5% (eight of 320; 95% CI: 0.8%, 4.2%), with secondary fracture the most frequent complication (1.2% [four of 320]; mean delay, 71 days); cryoablation site infection, tumor seeding, bleeding, and severe hypotension were each observed in 0.3% (one of 320) of procedures. Minor complications included postprocedural pain (2.2% [seven of 320]), peripheral neuropathy (0.9% [three of 320]), and temporary paresthesia (0.9% [three of 320]). For all complications, associated risk factors included ECOG-PS greater than 2 (odds ratio [OR], 3.1 [95% CI: 3, 7.6]; P = .01), long-bone cryoablation (OR, 17.8 [95% CI: 2.3, 136.3]; P = .01), and use of more than three cryoprobes (OR, 2.5 [95% CI: 1.0, 6.0]; P = .04); for major complications, associated risk factors included age greater than 70 years (OR, 7.1 [95% CI: 1.6, 31.7]; P = .01) and use of more than three cryoprobes (OR, 23.6 [95% CI: 2.8, 199.0]; P = .01). Conclusion Bone tumor cryoablation is safe, with a 2.5% rate of major complications, most commonly secondary fracture (1.2%). Major complications are associated with age greater than 70 years and use of more than three cryoprobes. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Jennings in this issue.

Accuracy of a CT-Ultrasound Fusion Imaging Guidance System Used for Hepatic Percutaneous Procedures.

PURPOSE: To evaluate the accuracy of a fusion imaging guidance system using ultrasound (US) and computerized tomography (CT) as a real-time imaging modality for the positioning of a 22-gauge needle in the liver. MATERIALS AND METHODS: The spatial coordinates of 23 spinal needles placed at the border of hepatic tumors before radiofrequency thermal ablation were determined in 23 patients. Needles were inserted up to the border of the tumor with the use of CT-US fusion imaging. A control CT scan was carried out to compare real (x, y, z) and virtual (x', y', z') coordinates of the tip of the needle (D for distal) and of a point on the needle located 3 cm proximally to the tip (P for proximal). RESULTS: The mean Euclidian distances were 8.5 ± 4.7 mm and 10.5 ± 5.3 mm for D and P, respectively. The absolute value of mean differences of the 3 coordinates (|x' - x|, |y' - y|, and |z' - z|) were 4.06 ± 0.9, 4.21 ± 0.84, and 4.89 ± 0.89 mm for D and 3.96 ± 0.60, 4.41 ± 0.86, and 7.66 ± 1.27 mm for P. X = |x' - x| and Y = |y' - y| coordinates were <7 mm with a probability close to 1. Z = |z' - z| coordinate was not considered to be larger nor smaller than 7 mm (probability >7 mm close to 50%). CONCLUSIONS: Positioning errors with the use of US-CT fusion imaging used in this study are not negligible for the insertion of a 22-gauge needle in the liver. Physicians must be aware of such possible errors to adapt the treatment when used for thermal ablation.