CT-Guided Core Needle Biopsy of Pulmonary Lesions Associated With Cystic Airspaces: A Case-Control Study.

BACKGROUND. Concern may exist that pulmonary lesions associated with cystic airspaces are at risk of increased biopsy complications or lower biopsy accuracy given challenges in targeting tissue abutting or intermingled with the cystic airspaces. OBJECTIVE. The purpose of this study was to evaluate the safety and diagnostic performance of CT-guided core needle biopsy (CNB) of pulmonary lesions associated with cystic airspaces. METHODS. This retrospective study included 90 patients (median age, 69.5 years; 28 women, 62 men) who underwent CT-guided CNB of pulmonary lesions associated with cystic airspaces (based on review of procedural images) from February 2010 to December 2022 and a matched control group (2:1 ratio) of 180 patients (median age, 68.0 years; 56 women, 124 men) who underwent CNB of noncystic noncavitary lesions during the same period. The groups were compared in terms of complications, nondiagnostic biopsies (i.e., nonspecific benignities, atypical cells, or insufficient specimens), and CNB diagnostic performance for detecting malignancy using as reference the final diagnosis from a joint review of all available records. For lesions associated with cystic airspaces that underwent surgical resection after CNB, histologic slides were reviewed to explore the nature of the cystic airspace. RESULTS. The final diagnosis was malignant in 90% (81/90) of lesions associated with cystic airspaces and 92% (165/180) of noncystic noncavitary lesions. Patients with lesions associated with cystic airspaces and patients with noncystic noncavitary lesions showed no significant difference in frequency of complications (overall: 40% [36/90] vs 38% [68/180], p = .79; major: 4% [4/90] vs 6% [10/180], p = .78; minor: 36% [32/90] vs 32% [58/180], p = .59), frequency of nondiagnostic biopsies (12% [11/90] vs 9% [16/180], p = .40), or diagnostic performance (accuracy: 94% [85/90] vs 97% [175/180], p = .50; sensitivity: 94% [76/81] vs 97% [160/165], p = .50; specificity: 100% [9/9] vs 100% [15/15]; p > .99), respectively. All false-negative results for malignancy in both groups occurred in patients with nondiagnostic CNB results. Among lesions associated with cystic airspaces that were resected after CNB (all malignant), the cystic airspaces most commonly represented tumor degeneration (22/31 [71%]). CONCLUSION. CT-guided CNB is safe and accurate for assessing pulmonary lesions associated with cystic airspaces. CLINICAL IMPACT. CNB may help avoid a missed or delayed cancer diagnosis in pulmonary lesions with cystic airspaces.

Multi-institutional analysis of outcomes for thermosphere microwave ablation treatment of colorectal liver metastases: the SMAC study.

OBJECTIVES: Oligometastatic colorectal cancer benefits of locoregional treatments but data concerning microwave ablation (MWA) are limited and interactions with systemic therapy are still debated. The aim of this study is to evaluate safety and effectiveness of Thermosphere™ MWA (T-MWA) of colorectal liver metastases (CLM) and factors affecting local tumor progression-free survival (LTPFS). METHODS: In this multi-institutional retrospective study (January 2015-September 2019), patients who underwent T-MWA for CLM were enrolled. Complications according to SIR classification were collected, primary efficacy and LTP were calculated. Analyzed variables included CLM size at diagnosis and at ablation, CLM number, ablation margins, intra-segment progression, chemotherapy before ablation (CBA), variations in size (ΔSDIA-ABL), and velocity of size variation (VDIA-ABL) between CLM diagnosis and ablation. Uni/multivariate analyses were performed using mixed effects Cox model to account for the hierarchical structure of data, patient/lesions. RESULTS: One hundred thirty-two patients with 213 CLM were evaluated. Complications were reported in 6/150 procedures (4%); no biliary complications occurred. Primary efficacy was achieved in 204/213 CLM (95.7%). LTP occurred in 58/204 CLM (28.4%). Six-, twelve-, and eighteen-month LTPFS were 88.2%, 75.8%, and 69.9%, respectively. At multivariate analysis, CLM size at ablation (p = 0.00045), CLM number (p = 0.046), ablation margin < 5 mm (p = 0.0035), and intra-segment progression (p < 0.0001) were statistically significant for LTPFS. ΔSDIA-ABL (p = 0.63) and VDIA-ABL (p = 0.38) did not affect LTPFS. Ablation margins in the chemo-naïve group were larger than those in the CBA group (p < 0.0001). CONCLUSION: T-MWA is a safe and effective technology with adequate LTPFS rates. Intra-segment progression is significantly linked to LTPFS. CBA does not affect LTPFS. Anticipating ablation before chemotherapy may take the advantages of adequate tumor size with correct ablation margin planning. KEY POINTS: • Thermosphere™-Microwave ablation is a safe and effective treatment for colorectal liver metastases with no registered biliary complications in more than 200 ablations. • Metastases size at time of ablation, intra-segment progression, and minimal ablation margin < 5 mm were found statistically significant for local tumor progression-free survival. • Chemotherapy before ablation modifies kinetics growth of the lesions but deteriorates ablation margins and does not significantly impact local tumor progression-free survival.

Retrospective analysis of the application of CT scan in the emergency department to screen clinically asymptomatic COVID-19 before hospital admission.

BACKGROUND: The necessity to identify and isolate COVID-19 patients to avoid intrahospital cross infections is particularly felt as a challenge. Clinically occult SARS-CoV-2 infection among patients admitted to the hospital is always considered a risk during the pandemic. The aim of our study is to describe the application of CT scan to reveal unexpected COVID-19 in patients needing hospital admission. METHOD: In our emergency department, we prospectively enrolled adult patients needing hospital admission, without symptoms suspected of COVID-19, and showing negative reverse transcriptase-polymerase chain reaction (RT-PCR) swab test. CT scan was performed to diagnose clinically occult COVID-19 pneumonia. All the exams were read and discussed retrospectively by two expert radiologists and assigned to one of 4 exclusive diagnoses: typical (typCT), indeterminate (indCT), atypical (atyCT), negative (negCT). The clinical characteristics and final diagnoses were described and compared with the results of CT scans. RESULTS: From May 25 to August 18, 2020, we prospectively enrolled 197 patients. They showed 122 negCT, 52 atyCT, 22 indCT, and 1 typCT. Based on the CT imaging, the prevalence of suspected clinically occult COVID-19 pneumonia was 11.6% (23 patients). None had confirmation of SARS-CoV-2 infection after the hospital stay. Nineteen patients had negative serial RT-PCR while in 4 cases, the infection was excluded by clinical follow-up or appearance of positivity of RT-PCR after months. CONCLUSION: Our descriptive analysis confirms that CT scan cannot be considered a valid tool to screen clinically occult COVID-19, when the asymptomatic patients need hospitalization for other conditions. Application of personnel protections and distancing among patients remains the best strategies to limit the possibility of intrahospital cross-infections.

Standardizing percutaneous Microwave Ablation in the treatment of Lung Tumors: a prospective multicenter trial (MALT study).

OBJECTIVES: To prospectively assess reproducibility, safety, and efficacy of microwave ablation (MWA) in the treatment of unresectable primary and secondary pulmonary tumors. METHODS: Patients with unresectable primary and metastatic lung tumors up to 4 cm were enrolled in a multicenter prospective clinical trial and underwent CT-guided MWA. Treatments were delivered using pre-defined MW power and duration settings, based on target tumor size and histology classifications. Patients were followed for up to 24 months. Treatment safety, efficacy, and reproducibility were assessed. Ablation volumes were measured at CT scan and compared with ablation volumes obtained on ex vivo bovine liver using equal treatment settings. RESULTS: From September 2015 to September 2017, 69 MWAs were performed in 54 patients, achieving technical success in all cases and treatment completion without deviations from the standardized protocol in 61 procedures (88.4%). Immediate post-MWA CT scans showed ablation dimensions smaller by about 25% than in the ex vivo model; however, a remarkable volumetric increase (40%) of the treated area was observed at 1 month post-ablation. No treatment-related deaths nor complications were recorded. Treatments of equal power and duration yielded fairly reproducible ablation dimensions at 48-h post-MWA scans. In comparison with the ex vivo liver model, in vivo ablation sizes were systematically smaller, by about 25%. Overall LPR was 24.7%, with an average TLP of 8.1 months. OS rates at 12 and 24 months were 98.0% and 71.3%, respectively. CONCLUSIONS: Percutaneous CT-guided MWA is a reproducible, safe, and effective treatment for malignant lung tumors up to 4 cm in size. KEY POINTS: • Percutaneous MWA treatment of primary and secondary lung tumors is a repeatable, safe, and effective therapeutic option. • It provides a fairly reproducible performance on both the long and short axis of the ablation zone. • When using pre-defined treatment duration and power settings according to tumor histology and size, LPR does not increase with increasing tumor size (up to 4 cm) for both primary and metastatic tumors.

Primary Aorto-Duodenal Fistula in Association with Chronic Ischemic Enteritis: A Case Report.

BACKGROUND: Primary aorto-duodenal fistula (PADF) is a rare but life-threatening condition that should be taken into account when considering upper gastrointestinal bleeding in elderly patients with history of abdominal aortic aneurysm. Unfortunately, its diagnosis is often unsuspected until surgery or at postmortem. PRESENTATION OF CASE: We report a case of a 69 years old man with massive gastrointestinal bleeding secondary to a primary aortic duodenal fistula without a history of abdominal aortic aneurysm and with a misleading diagnosis of chronic ischemic enteritis. Repeated endoscopies and a prior CT angiography failed to document a proper diagnosis. Finally, the aorto-duodenal fistula was identified with a further abdominal CT angiography. Despite a prompt endovascular treatment with aortic endoprosthesis placement, the patient died due to a severe hemorrhagic shock consequent to the massive blood loss. DISCUSSION: Primary aorto-duodenal fistula represents a very rare (<0.1% of incidence) cause of severe upper gastrointestinal bleeding most often leading to patient's death for hemorrhagic shock. It is frequently associated to aortic atherosclerosis. Its prompt diagnosis with endoscopy and CT angiography is very often difficult and almost never immediate. Furthermore, these exams may be misleading. In case of massive upper GI bleeding without a certain diagnosis in patients with severe aortic atherosclerosis, laparotomy with careful inspection of the distal duodenum is strongly recommended for aortic repair and bowel suture. CONCLUSIONS: The diagnosis of PADF should be taken into account in patients with upper gastrointestinal bleeding associated with aortic atherosclerosis with strong suspect of penetrating ulcer.

Oligometastatic adrenocortical carcinoma: the role of image-guided thermal ablation.

OBJECTIVES: To evaluate the impact of image-guided ablation of liver and lung metastases from adrenocortical carcinoma (ACC). METHODS: Patients with oligometastatic ACC (liver and lung metastases) who underwent image-guided ablation were retrospectively included in the study. Complete ablation (CA) at the first contrast-enhanced CT control, local tumor progression (LTP), local tumor progression-free survival (LTPFS), liver disease-free survival (LDFS), and overall survival (OS) were evaluated. Correlation between outcomes and other prognostic factors (including Ki67, hormonal secretion, and progression-free survival after primary tumor resection (PR-PFS)) was also analyzed. Kaplan-Meier methods, log-rank tests, and Spearman correlation models were applied. RESULTS: Thirty-two ACC metastases (4 lung and 28 liver) from 16 patients (10 females; mean age 41 years) were treated with RFA or MWA. A single major adverse event was observed (intrahepatic hematoma with subsequent right hemothorax). One patient (2 lesions) was lost to follow-up. CA was obtained in 97% (29/30). During follow-up, LTP was registered in 7/29 cases (24.1%), with a median LTPFS of 21 months (± 12.6). Metastasis size was significantly higher in case of LTP (20 mm vs. 34.5 mm; p = 0.009) and was an independent predictive factor of local tumor control with an AUC of 0.934 (p = 0.0009). Hepatic progression was observed in 66% of the cases, with a median LDFS of 25 months. Median OS was 48.6 months. PR-PFS and hormonal secretion were independent predictors of OS (p < 0.001 and p = 0.045, respectively). CONCLUSIONS: Image-guided ablation achieves adequate local tumor control of ACC liver and lung metastases, providing a safe and effective treatment option in the multidisciplinary management of the oligometastatic ACC. KEY POINTS: • Image-guided ablation allows adequate local tumor control in the oligometastatic adrenocortical carcinoma setting. • After percutaneous thermal ablation, complete ablation was achieved in 29 out of 30 lesions (97%). • Lesion size together with primary resection disease-free survival and hormonal secretion play a significant role in determining outcomes.

Liquid biopsy, a paradigm shift in oncology: what interventional radiologists should know.

The acquisition of adequate tumor sample is required to verify primary tumor type and specific biomarkers and to assess response to therapy. Historically, invasive surgical procedures were the standard methods to acquire tumor samples until advancements in imaging and minimally invasive equipment facilitated the paradigm shift image-guided biopsy. Image-guided biopsy has improved sampling yield and minimized risk to the patient; however, there are still limitations, such as its invasive nature and its consequent limitations to longitudinal tumor monitoring. The next paradigm shift in sampling technique will need to address these issues to provide a more reliable and less invasive technique. Recently, liquid biopsy (LB) has emerged as a non-invasive alternative to tissue sampling. This technique relies on direct sampling of blood or other bodily fluids in contact with the tumor in order to collect circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and circulating RNAs-in particular microRNA (miRNAs). Clinical applications of LB involve different steps of cancer patient management including screening, detection of disease recurrence, and evaluation of acquired resistance. With any paradigm shift, old techniques are often relegated to a secondary option. Although image-guided biopsies may appear as a passive spectator on the rapid advancement of LB, the two techniques may well be codependent. Interventional radiology may be integral to directly sample the liquid surrounding or draining from the tumor. In addition, LB may help to correctly select the patients for image-guided loco-regional treatments, to determine its treatment endpoint, and to early detect recurrence. KEY POINTS: • Liquid biopsy is a novel technology with potential high impact in the management of patients undergoing image-guided procedures. • Interventional radiology procedures may increase liquid biopsy sensitivity through direct fluid sampling. • Liquid biopsy techniques may provide a venue for improving patients' selection and enhance outcomes of interventional loco-regional therapies performed by interventional radiologists.

Characterization of the arterial enhancement pattern of focal liver lesions by multiple arterial phase magnetic resonance imaging: comparison between hepatocellular carcinoma and focal nodular hyperplasia.

PURPOSE: To evaluate the features of arterial enhancement pattern of focal nodular hyperplasia (FNH) and hepatocellular carcinoma (HCC) by triple-phase arterial magnetic resonance imaging (MRI). METHODS: Data were retrospectively collected from 52 consecutive patients who underwent triple-phase arterial MRI using hepatocyte-specific contrast agents (Gd-EOB-DTPA) from January 2017 to October 2017, with a MR imaging diagnosis of HCC or FNH. The images were independently assessed by two blinded readers. Contrast enhancement ratio (CER) and liver-to-lesion contrast ratio (LLCR) were calculated. The lesions were classified visually and also based on the peak of LLCR into the following groups: (1) early arterial, (2) middle arterial and (3) late arterial. Data were eventually analysed using nonparametric tests. RESULTS: The CER analysis showed no significant difference between HCC and FNH patients (p > 0.05). LLCRFNH were significantly higher than LLCRHCC in the early arterial (p = 0.01), but not in the middle and late arterial phases (p = 0.20 and p = 0.82, respectively). LLCRHCC presented a meaningful increase from early to middle arterial phase (p = 0.009), whereas LLCRFNH showed a decrease from middle to late arterial phase (p = 0.004). Based on the peak of LLCR, 17 (55%) FNHs were classified into early, 11 (35%) in middle and only 3 (10%) in late arterial phase groups. Similarly, 14 (34%) HCCs were categorized into early, 13 (32%) in middle and 14 (33%) in late arterial phase groups. There was a good agreement between qualitative analysis and LLCR in 85% of cases. CONCLUSION: The optimal visualization of FNH has been detected in early and middle arterial phases while HCC has been best observed during middle and late arterial phases.

Baseline chest X-ray in coronavirus disease 19 (COVID-19) patients: association with clinical and laboratory data.

PURPOSE: To assess the reliability of CXR and to describe CXR findings and clinical and laboratory characteristics associated with positive and negative CXR. METHODS: Retrospective two-center study on consecutive patients admitted to the emergency department of two north-western Italian hospitals in March 2020 with clinical suspicion of COVID-19 confirmed by RT-PCR and who underwent CXR within 24 h of the swab execution. 260 patients (61% male, 62.8 ± 15.8 year) were enrolled. CXRs were rated as positive (CXR+) or negative (CXR-), and features reported included presence and distribution of airspace opacities, pleural effusion and reduction in lung volumes. Clinical and laboratory data were collected. Statistical analysis was performed with nonparametric tests, binary logistic regression (BLR) and ROC curve analysis. RESULTS: Sensitivity of CXR was 61.1% (95%CI 55-67%) with a typical presence of bilateral (62.3%) airspace opacification, more often with a lower zone (88.7%) and peripheral (43.4%) distribution. At univariate analysis, several factors were found to differ significantly between CXR+ and CXR-. The BLR confirmed as significant predictors only lactate dehydrogenase (LDH), C-reactive protein (CRP) and interval between the onset of symptoms and the execution of CXR. The ROC curve procedure determined that CRX+ was associated with LDH > 500 UI/L (AUC = 0.878), CRP > 30 mg/L (AUC = 0.830) and interval between the onset of symptoms and the execution of CXR > 4 days (AUC = 0.75). The presence of two out of three of the above-mentioned predictors resulted in CXR+ in 92.5% of cases, whereas their absence in 7.4%. CONCLUSION: CXR has a low sensitivity. LDH, CRP and interval between the onset of symptoms and the execution of CXR are major predictors for a positive CXR.

Case 261: Thymoma Embedded in Thymus with Pleural Implant in Myasthenia Gravis Lambert-Eaton Overlap Syndrome.

History A 29-year-old woman presented with a 6-month history of progressive general fatigue, fluctuating limb weakness, and difficulty climbing stairs. She initially experienced occasional episodes of transient diplopia that developed while reading in the evening. She subsequently started to experience dry eyes and mouth, difficulty chewing, and mild dysphagia that worsened throughout the day. Her medical history included hypothyroidism from Hashimoto thyroiditis and pneumonia with left pleural effusion. She had no smoking history, and her body mass index was normal (23.8 kg/m2). No medication use was reported at admission. Physical examination revealed mild bilateral ptosis, reduced muscle tone and strength that worsened in proximal leg muscles, and decreased deep tendon reflexes. An edrophonium test revealed improvement in muscle strength and eyelid ptosis. Repetitive nerve stimulation revealed low amplitude of compound muscle action potential at rest (0.21 mV), with a marked increase (700%; normal increase, <60%) at high-rate stimulation (50 Hz). Laboratory work-up was unremarkable except for detection of acetylcholine receptor antibodies in the serum (21.30 nmol/L) and P/Q-type voltage-gated calcium channel antibodies (220 pmol/L). Recent MRI of the brain and spine at an outside hospital showed no abnormal findings. At admission, the patient underwent CT of the chest, abdomen, and pelvis followed by thoracic MRI to further evaluate CT findings.

Thermal ablation with fusion imaging guidance of hepatocellular carcinoma without conspicuity on conventional or contrast-enhanced US: surrounding anatomical landmarks matter.

AIM: Evaluating clinical and technical factors affecting thermal ablation of B-Mode/CEUS inconspicuous HCC nodules, relying only on fusion imaging (FI) performed under conscious sedation and using previously acquired CT or MR. MATERIALS AND METHODS: Among 367 HCC nodules treated in the study period, data of 37 B-mode/CEUS undetectable HCC nodules treated with FI-guided ablation were extracted from our prospectively collected institutional database. Analyzed variables included patients' sex, age, cirrhosis etiology, Child-Pugh status, size of the lesion, liver segment, subcapsular or central liver site, type of imaging used for fusion (MR/CT), and the presence of surrounding anatomical landmarks (SAL) < 3 cm from the index lesion. RESULTS: The primary efficacy was 59.4% (22/37 nodules); nine lesions (24.3%) were partially ablated (PA), six lesions (16.7%) were mistargeted (MA). Eight nodules were retreated with a CA obtained in all cases (100% CA, secondary efficacy in 30/37-81.1%). LTP was observed in 2/30 cases (6.7%). Two minor complications were registered (Clavien-Dindo, Grade1, CIRSE Classification Grade 2). SAL were related to a better ablation outcome (37.5% vs 84.6% p = 0.01). No differences were observed between CA group and PA-MA group in terms of lesion size (15.4 mm vs 14.9 mm p = 0.63), liver segment (p = 0.58), subcapsular or central liver site (8/22 36% vs 4/15 26.7% p = 0.84), and imaging (MR vs CT, p = 0.72). CONCLUSION: Even in the presence of potentially critical conditions (completely B-Mode/CEUS inconspicuous nodules, spontaneous breathing, and previously acquired CT or MRI), FI-only guidance is safe and allows having good primary, secondary efficacy and LTP rates. The outcome of the procedure is heavily affected by the presence of SAL.

Case 261.

History A 29-year-old woman presented with a 6-month history of progressive general fatigue, fluctuating limb weakness, and difficulty climbing stairs. She initially experienced occasional episodes of transient diplopia that developed while reading in the evening. She subsequently started to experience dry eyes and mouth, difficulty chewing, and mild dysphagia that worsened throughout the day. Her medical history included hypothyroidism from Hashimoto thyroiditis and pneumonia with left pleural effusion. She had no smoking history, and her body mass index was normal (23.8 kg/m2). No medication use was reported at admission. Physical examination revealed mild bilateral ptosis, reduced muscle tone and strength that worsened in proximal leg muscles, and decreased deep tendon reflexes. An edrophonium test revealed improvement in muscle strength and eyelid ptosis. Repetitive nerve stimulation revealed low amplitude of compound muscle action potential at rest (0.21 mV), with a marked increase (700%; normal increase, <60%) at high-rate stimulation (50 Hz). Laboratory work-up was unremarkable except for detection of acetylcholine receptor antibodies in the serum (21.30 nmol/L) and P/Q-type voltage-gated calcium channel antibodies (220 pmol/L). Recent MRI of the brain and spine at an outside hospital showed no abnormal findings. At admission, the patient underwent CT of the chest, abdomen, and pelvis ( Fig 1 ) followed by thoracic MRI ( Figs 2 , 3 ) to further evaluate CT findings. [Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text].

Nonsuppressing normal thymus on chemical-shift MR imaging and anterior mediastinal lymphoma: differentiation with diffusion-weighted MR imaging by using the apparent diffusion coefficient.

OBJECTIVES: To prospectively evaluate usefulness of the apparent diffusion coefficient (ADC) in differentiating anterior mediastinal lymphoma from nonsuppressing normal thymus on chemical-shift MR, and to look at the relationship between patient age and ADC. METHODS: Seventy-three young subjects (25 men, 48 women; age range, 9-29 years), who underwent chemical-shift MR and diffusion-weighted MR were divided into a normal thymus group (group A, 40 subjects), and a lymphoma group (group B, 33 patients). For group A, all subjects had normal thymus with no suppression on opposed-phase chemical-shift MR. Two readers measured the signal intensity index (SII) and ADC. Differences in SII and ADC between groups were tested using t-test. ADC was correlated with age using Pearson correlation coefficient. RESULTS: Mean SII±standard deviation was 2.7±1.8% for group A and 2.2±2.4% for group B, with no significant difference between groups (P=.270). Mean ADC was 2.48±0.38x10-3mm2/s for group A and 1.24±0.23x10-3mm2/s for group B. A significant difference between groups was found (P<.001), with no overlap in range. Lastly, significant correlation was found between age and ADC (r=0.935, P<.001) in group A. CONCLUSIONS: ADC of diffusion-weighted MR is a noninvasive and accurate parameter for differentiating lymphoma from nonsuppressing thymus on chemical-shift MR in young subjects. KEY POINTS: • SII cannot differentiate mediastinal lymphoma from nonsuppressing normal thymus at visual assessment • ADC is useful for distinguishing nonsuppressing normal thymus from mediastinal lymphoma • ADC is more accurate than transverse-diameter and surface-area in this discrimination • ADC of normal thymus is age dependent and increases with increasing age.

Ablation of colorectal liver metastasis: Interaction of ablation margins and RAS mutation profiling on local tumour progression-free survival.

OBJECTIVES: To investigate effects of ablation margins on local tumour progression-free survival (LTPFS) according to RAS status in patients with colorectal liver metastases (CLM). METHODS: This two-institution retrospective study from 2005-2016 included 136 patients (91 male, median age 60 years) with 218 ablated CLM. LTPFS was performed using the Kaplan-Meier method and evaluated with the log-rank test. Uni/multivariate analyses were performed using Cox-regression models. RESULTS: Three-year LTPFS rates for CLM with minimal ablation margin ≤10 mm were significantly worse than those with >10 mm in both mutant-RAS (29% vs. 48%, p=0.038) and wild-type RAS (70% vs. 94%, p=0.039) subgroups. Three-year LTPFS rates of mutant-RAS were significantly worse than wild-type RAS in both CLM subgroups with minimal ablation margin ≤10 mm (29% vs. 70%, p<0.001) and >10 mm (48% vs. 94%, p=0.006). Predictors of worse LTPFS were ablation margins ≤10 mm (HR: 2.17, 95% CI 1.2-4.1, p=0.007), CLM size ≥2 cm (1.80, 1.1-2.8, p=0.017) and mutant-RAS (2.85, 1.7-4.6, p<0.001). CONCLUSIONS: Minimal ablation margin and RAS status interact as independent predictors of LTPFS following CLM ablation. While minimal ablation margins >10 mm should be always the procedural goal, this becomes especially critical for mutant-RAS CLM. KEY POINTS: • RAS and ablation margins are predictors of local tumour progression-free survival. • Ablation margin >10 mm, always desirable, is crucial for mutant RAS metastases. • Interventional radiologists should be aware of RAS status to optimize LTPFS.

Interventional locoregional treatment and metabolic response: advantages of using PET/CT in the evaluation of response to treatment.

INTRODUCTION: Interventional oncology locoregional therapies are validated treatment modalities for primary and secondary tumors in liver, lung, kidney and bone. At this time, there is no accordance in the choice of imaging modality to assess treatment response. Morphological imaging and RECIST 1.1 criteria based on size variation are limited by several critical points. On the other hand the role of functional imaging, in particular by [18F]-fluorodeoxyglucose ([18F]-FDG) positron emission tomography (PET), in both staging and response evaluation of locoregional treatments remains unclear because of the heterogeneous nature of available data. The aim of this paper was to summarize the available literature illustrating the state of art of metabolic evaluation of response after locoregional therapies in the three major organs of interest: liver, lung and bone. EVIDENCE ACQUISITION: Medline database was searched for relevant original paper evaluating the role of [18F]-FDG PET in interventional oncology treatment published up to June 2017 excluding case reports. EVIDENCE SYNTHESIS: Finally 41 studies papers evaluating the role of [18F]-FDG PET in both staging and in response evaluation of locoregional treatments focused on liver tumoral lesions (N.=29), on lung lesions (N.=10) and on bone lesions (N.=2) were considered for this review. CONCLUSIONS: PET/CT appears to perform well in the assessment of response to interventional therapies compared to conventional imaging, not only in terms of response evaluation but also as a possible prognostic tool. Nevertheless further prospective, homogenous studies are required to confirm these data, in particular for lung and bone lesions.

Dual-Energy X-ray Absorptiometry Predictors of Vertebral Deformities in Beta-Thalassemia Major.

Vertebral fractures in beta-thalassemia major are increasingly found because of the longer life expectancy of patients, with a major negative impact on their quality of life. We performed a retrospective cross-sectional study to investigate the prevalence of vertebral deformities in thalassemic patients and to identify their best dual-energy X-ray absorptiometry (DXA) predictor among trabecular bone score (TBS), bone mineral density (BMD), and Z-score. Eighty-two outpatients with beta-thalassemia major on regular conventional treatment were studied at a single academic center. All patients underwent plain thoracic-lumbar spine X-rays and lumbar DXA to assess the number and the severity of vertebral deformities (Genant's method), the spinal deformity index, lumbar spine DXA parameters (BMD, TBS, and Z-score), and the presence of platyspondyly. Twenty-nine patients (35%) had vertebral deformities and showed significantly lower TBSs than the remainders (1.141 ± 0.083 vs 1.254 ± 0.072, p < 0.0001). The analysis of variance of the TBS between the group of patients without vertebral deformities (spinal deformity index = 0) and the remaining groups showed a significant difference (p < 0.001). The TBS had better sensitivity (86.2%), specificity (75.5%), and diagnostic accuracy (79.3%) than BMD and Z-score in discriminating patients with and without vertebral deformities. Combining the TBS with the BMD or the Z-score showed that the diagnostic accuracy of the first in discriminating patients with and without vertebral deformities improved from 79.3% to 85.4% and 87.8%, respectively. The presence of platyspondyly was a significant predictor of vertebral deformities in the multivariate model. Vertebral deformities in well-treated patients with beta-thalassemia major are common and are often unrecognized. In our hands, the TBS was better than the BMD and the Z-score in predicting vertebral deformities. Plain X-rays of the spine should be performed also in asymptomatic patients, especially when the TBS is low.

Osteoporotic Hip Fracture Prediction: Is T-Score-Based Criterion Enough? A Hip Structural Analysis-Based Model.

At present, the current gold-standard for osteoporosis diagnosis is based on bone mineral density (BMD) measurement, which, however, has been demonstrated to poorly estimate fracture risk. Further parameters in the hands of the clinicians are represented by the hip structural analysis (HSA) variables, which include geometric information of the proximal femur cross section. The purpose of this study was to investigate the suitability of HSA parameters as additional hip fracture risk predictors. With this aim, twenty-eight three-dimensional patient-specific models of the proximal femur were built from computed tomography (CT) images and a sideways fall condition was reproduced by finite element (FE) analyses. A tensile or compressive predominance based on minimum and maximum principal strains was determined at each volume element and a risk factor (RF) was calculated. The power of HSA variables combinations to predict the maximum superficial RF values was assessed by multivariate linear regression analysis. The optimal regression model, identified through the Akaike information criterion (AIC), only comprises two variables: the buckling ratio (BR) and the neck-shaft angle (NSA). In order to validate the study, the model was tested on two additional patients who suffered a hip fracture after a fall. The results classified the patients in the high risk level, confirming the prediction power of the adopted model.

Diffusion-weighted quantitative MRI of pleural abnormalities: Intra- and interobserver variability in the apparent diffusion coefficient measurements.

PURPOSE: To assess intra- and interobserver variability in the apparent diffusion coefficient (ADC) measurements of pleural abnormalities. MATERIALS AND METHODS: Diffusion-weighted magnetic resonance imaging was performed in 34 patients to characterize pleural abnormalities, with a 1.5T unit at b values of 0/150/500/800 sec/mm2 . In two sessions held 3 months apart, on perfusion-free ADC maps, two independent readers measured the ADC of pleural abnormalities (two readings for each reader in each case) using different methods of region-of-interest (ROI) positioning. In three methods, freehand ROIs were drawn within tumor boundaries to encompass the entire lesion on one or more axial slices (whole tumor volume [WTV], three slices observer-defined [TSOD], single-slice [SS]), while in two methods one or more ROIs were placed on the more restricted areas (multiple small round ROI [MSR], one small round ROI [OSR]). Measurement variability between readings by each reader (intraobserver repeatability) and between readers in first reading (interobserver repeatability) were assessed using intraclass correlation coefficient (ICC) and coefficient of variation (CoV). Analysis of variance (ANOVA) was performed to compare ADC values between the different methods. The measurement time of each case for all methods in first reading was recorded and compared between methods and readers. RESULTS: All methods demonstrated good (MSR, OSR) and excellent (WTV, TSOD, SS) intra- and interreader agreement, with best and worst repeatability in WTV (lower ICC, 0.977; higher CoV, 3.5%) and OSR (lower ICC, 0.625; higher CoV, 22.8%), respectively. The lower 95% confidence interval of ICC resulted in fair to moderate agreement for OSR (up to 0.379) and in excellent agreement for WTV, TSV, and SS (up to 0.918). ADC values of OSR and MSR were significantly lower compared to other methods (P < 0.001). The OSR and SS required less measurement time (10 and 21/22 sec, respectively) compared to the others (P < 0.0001), while the WTV required the longest measurement time (132/134 sec) (P < 0.0001). CONCLUSION: ADC measurements of pleural abnormalities are repeatable. The SS method has excellent repeatability, similar to WTV, but requires significantly less measurement time. Thus, its use should be preferred in clinical practice. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:769-782.

Apparent diffusion coefficient measurements in diffusion-weighted magnetic resonance imaging of the anterior mediastinum: inter-observer reproducibility of five different methods of region-of-interest positioning.

OBJECTIVES: To investigate inter-reader reproducibility of five different region-of-interest (ROI) protocols for apparent diffusion coefficient (ADC) measurements in the anterior mediastinum. METHODS: In eighty-one subjects, on ADC mapping, two readers measured the ADC using five methods of ROI positioning that encompassed the entire tissue (whole tissue volume [WTV], three slices observer-defined [TSOD], single-slice [SS]) or the more restricted areas (one small round ROI [OSR]), multiple small round ROI [MSR]). Inter-observer variability was assessed with interclass correlation coefficient (ICC), coefficient of variation (CoV), and Bland-Altman analysis. Nonparametric tests were performed to compare the ADC between ROI methods. The measurement time was recorded and compared between ROI methods. RESULTS: All methods showed excellent inter-reader agreement with best and worst reproducibility in WTV and OSR, respectively (ICC, 0.937/0.874; CoV, 7.3 %/16.8 %; limits of agreement, ±0.44/±0.77 × 10-3 mm2/s). ADC values of OSR and MSR were significantly lower compared to the other methods in both readers (p < 0.001). The SS and OSR methods required less measurement time (14 ± 2 s) compared to the others (p < 0.0001), while the WTV method required the longest measurement time (90 ± 56 and 77 ± 49 s for each reader) (p < 0.0001). CONCLUSIONS: All methods demonstrate excellent inter-observer reproducibility with the best agreement in WTV, although it requires the longest measurement time. KEY POINTS: • All ROI protocols show excellent inter-observer reproducibility. • WTV measurements provide the most reproducible ADC values. • ROI size and positioning influence ADC measurements in the anterior mediastinum. • ADC values of OSR and MSR are significantly lower than other methods. • OSR and WTV methods require the shortest and longest measurement time, respectively.

Diffusion-weighted quantitative MRI to diagnose benign conditions from malignancies of the anterior mediastinum: Improvement of diagnostic accuracy by comparing perfusion-free to perfusion-sensitive measurements of the apparent diffusion coefficient.

PURPOSE: To compare perfusion-free to perfusion-sensitive measurements of the apparent diffusion coefficient (ADC) to diagnose benign conditions from malignancies of the anterior mediastinum. MATERIALS AND METHODS: Seventy-six subjects were divided into a "benign conditions" group (A, n = 44) and a "malignancies" group (B, n = 32), based on histological findings. diffusion-weighted magnetic resonance imaging (DW-MRI) was performed at b of 0/150/800 sec/mm(2) . The ADCs were obtained on an ADC map by including (perfusion-sensitive = ADCb0-800 ) and excluding (perfusion-free = ADCb150-800 ) the b = 0 sec/mm(2) . The Mann-Whitney U-test was used to detect differences in ADCb0-800 compared with ADCb150-800 values between all cases, benign conditions, and malignancies. The same test was used to evaluate differences in ADCs between the two groups for each type of measurement (ADCb0-800 and ADCb150-800 ), and receiver-operating characteristic (ROC) curves were obtained to evaluate discrimination abilities with comparison of areas-under-ROC-curves (AUROC). Optimal cutpoints for discrimination between groups were determined by the Youden-Index with computation of accuracy. RESULTS: The median ADCb0-800 was significantly greater compared with ADCb150-800 for all cases (P = 0.0014), benign conditions (P = 0.0412), and malignancies (P = 0.0001). The median percentage of increase was 5.30% for group-A and 22.39% for group-B (P < 0.0001). AUROC of ADC in discriminating between groups was significantly greater for ADCb150-800 (0.932) compared with ADCb0-800 (0.831) (P = 0.001). The optimal cutpoint for distinction between groups was 1.52 × 10(-3) mm(2) /sec (sensitivity = 93.7%, specificity = 88.6%, accuracy = 90.8%) for ADCb150-800 and 1.75 × 10(-3) mm(2) /sec (sensitivity = 75.0%, specificity = 79.5%, accuracy = 77.6%) for ADCb0-800 . CONCLUSION: The use of perfusion-free ADC measurements significantly improves diagnostic accuracy of DW-MRI in differentiating benign conditions from malignancies of the anterior mediastinum. J. Magn. Reson. Imaging 2016;44:758-769.