Electronic Health Record Order Entry-Based Interventions in Response to a Global Iodinated Contrast Media Shortage: Impact on Contrast-Enhanced CT Utilization.

BACKGROUND. Radiology informatics systems and clinical decision support tools in the electronic health record (EHR) can be leveraged to help impact ordering patterns in response to the ongoing global iodinated contrast media shortage. OBJECTIVE. The purpose of our study was to assess the impact of EHR order entry-based interventions, implemented as part of a health system's response to the global contrast media shortage, on contrast-enhanced CT utilization. METHODS. This retrospective study included 79,259 patients who underwent CT at a large multisite health system between April 1, 2022, and July 3, 2022. Two EHR-based interventions were implemented as part of the health system's response to the global contrast media shortage. A first EHR-based intervention on May 10, 2022, entailed creating an alert that appeared in a sidebar after any contrast-enhanced body CT orders, indicating the present shortage and recommending alternate imaging modalities. A second EHR-based intervention on May 16, 2022, required referrers to enter detailed clinical information for all contrast-enhanced body CT orders, which radiologists used when protocoling examinations. Data regarding CT orders and examinations performed were extracted from the electronic data warehouse. RESULTS. During the preintervention, first postintervention, and second postintervention periods, the mean number of patients who underwent contrast-enhanced CT per weekday was 726, 689, and 639, respectively (p for preintervention vs second postintervention periods, < .001). During the three periods, the mean number of patients who underwent CT per weekday was 1350, 1323, and 1314 (p < .001). During the three periods, the mean number of patients who underwent contrast-enhanced body CT per weekday was 561, 532, and 492 (p < .001). During the three periods, the mean number of orders for CT with IV contrast media per weekday was 154, 143, and 131 (p < .001). During the three periods, the mean number of orders for CT without IV contrast media per weekday was 196, 202, and 221 (p < .001). CONCLUSION. EHR order entry-based interventions implemented in response to the global contrast media shortage significantly reduced contrast-enhanced CT utilization in a large health system. CLINICAL IMPACT. The findings indicate the ability to rapidly achieve changes in ordering clinician behavior and subsequent clinical practice using systemwide EHR changes.

Consensus Guidelines for the Definition of Time-to-Event End Points in Image-guided Tumor Ablation: Results of the SIO and DATECAN Initiative.

There is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue.

Abdominal Imaging Findings in COVID-19: Preliminary Observations.

Background Angiotensin-converting enzyme 2, a target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demonstrates its highest surface expression in the lung, small bowel, and vasculature, suggesting abdominal viscera may be susceptible to injury. Purpose To report abdominal imaging findings in patients with coronavirus disease 2019. Materials and Methods In this retrospective cross-sectional study, patients consecutively admitted to a single quaternary care center from March 27 to April 10, 2020, who tested positive for SARS-CoV-2 were included. Abdominal imaging studies performed in these patients were reviewed, and salient findings were recorded. Medical records were reviewed for clinical data. Univariable analysis and logistic regression were performed. Results A total of 412 patients (average age, 57 years; range, 18 to >90 years; 241 men, 171 women) were evaluated. A total of 224 abdominal imaging studies were performed (radiography, n = 137; US, n = 44; CT, n = 42; MRI, n = 1) in 134 patients (33%). Abdominal imaging was associated with age (odds ratio [OR], 1.03 per year of increase; P = .001) and intensive care unit (ICU) admission (OR, 17.3; P < .001). Bowel-wall abnormalities were seen on 31% of CT images (13 of 42) and were associated with ICU admission (OR, 15.5; P = .01). Bowel findings included pneumatosis or portal venous gas, seen on 20% of CT images obtained in patients in the ICU (four of 20). Surgical correlation (n = 4) revealed unusual yellow discoloration of the bowel (n = 3) and bowel infarction (n = 2). Pathologic findings revealed ischemic enteritis with patchy necrosis and fibrin thrombi in arterioles (n = 2). Right upper quadrant US examinations were mostly performed because of liver laboratory findings (87%, 32 of 37), and 54% (20 of 37) revealed a dilated sludge-filled gallbladder, suggestive of bile stasis. Patients with a cholecystostomy tube placed (n = 4) had negative bacterial cultures. Conclusion Bowel abnormalities and gallbladder bile stasis were common findings on abdominal images of patients with coronavirus disease 2019. Patients who underwent laparotomy often had ischemia, possibly due to small-vessel thrombosis. © RSNA, 2020.

Performance of 18F-fluciclovine PET/MR in the evaluation of osseous metastases from castration-resistant prostate cancer.

PURPOSE: 18F-Fluciclovine is indicated for evaluation of suspected prostate cancer (PCa) biochemical recurrence. There are few studies investigating fluciclovine with PET/MR and none evaluated osseous metastases. Our aim was to assess the performance of 18F-fluciclovine PET/MR (fluciclovine-PET/MR) for detecting osseous metastases in patients with castration-resistant prostate cancer (CRPC). We also investigated possible correlations between SUVmax and ADCmean. METHODS: We evaluated 8 patients with CRPC metastatic to bones, some before and some after radium therapy, who underwent 13 fluciclovine-PET/MR studies. We analyzed the performance of radionuclide bone scan (RBS), MR alone, fluciclovine-PET alone, and fluciclovine-PET/MR in detecting osseous metastases. Lesion size, characteristics (early sclerotic, late sclerotic, mixed, lytic), SUVmax, and ADCmean were assessed. The reference standard was a combination of clinical information and correlation with both prior and follow-up imaging. RESULTS: Of 347 metastatic bony lesions in 13 studies, 238/347 (68%) were detected by fluciclovine-PET alone, 286/347 (82%) by RBS, 344/347 (99%) by MR alone, and 347/347 (100%) by fluciclovine-PET/MR. Fluciclovine-PET/MR and MR had the best performance (p < 0.001). There was no statistically significant difference between fluciclovine-PET/MR and MR alone (p = 0.25). Fluciclovine-PET had a lower detection rate especially with late sclerotic lesions (p < 0.001). There was a moderate inverse correlation between lesion SUVmax and ADCmean (r = - 0.49; p < 0.001). CONCLUSIONS: This study suggests that fluciclovine-PET/MR and MR have high sensitivity for detecting osseous metastases in CRPC. Fluciclovine-PET alone underperformed in detecting late sclerotic lesions. The inverse correlation between SUVmax and ADCmean suggests a possible relationship between tumor metabolism and cellularity.

Management implications of fluorodeoxyglucose positron emission tomography/magnetic resonance in untreated intrahepatic cholangiocarcinoma.

PURPOSE: Intrahepatic cholangiocarcinoma (ICC) is associated with a poor prognosis with surgical resection offering the best chance for long-term survival and potential cure. However, in up to 36% of patients who undergo surgery, more extensive disease is found at time of operation requiring cancellation of surgery. PET/MR is a novel hybrid technology that might improve local and whole-body staging in ICC patients, potentially influencing clinical management. This study was aimed to investigate the possible management implications of PET/MR, relative to conventional imaging, in patients affected by untreated intrahepatic cholangiocarcinoma. METHODS: Retrospective review of the clinicopathologic features of 37 patients with iCCC, who underwent PET/MR between September 2015 and August 2018, was performed to investigate the management implications that PET/MR had exerted on the affected patients, relative to conventional imaging. RESULTS: Of the 37 patients enrolled, median age 63.5 years, 20 (54%) were female. The same day PET/CT was performed in 26 patients. All patients were iCCC-treatment-naïve. Conventional imaging obtained as part of routine clinical care demonstrated early-stage resectable disease for 15 patients and advanced stage disease beyond the scope of surgical resection for 22. PET/MR modified the clinical management of 11/37 (29.7%) patients: for 5 patients (13.5%), the operation was cancelled due to identification of additional disease, while 4 "inoperable" patients (10.8%) underwent an operation. An additional 2 patients (5.4%) had a significant change in their operative plan based on PET/MR. CONCLUSIONS: When compared with standard imaging, PET/MR significantly influenced the treatment plan in 29.7% of patients with iCCC. TRIAL REGISTRATION: 2018P001334.

Hybrid imaging of the abdomen and pelvis.

Accurate imaging is crucial for lesion detection in abdominal organs, for the noninvasive characterization of focal and diffuse abnormalities, and for surgical planning. To accomplish these tasks, several imaging modalities such as multidetector computer tomography (MDCT), magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) are used for abdominal imaging, providing important morphological, functional or metabolic information. More recently, PET/MRI has been gaining attention due to the possibility of combining high-resolution imaging with metabolic imaging. PET/MRI is a novel hybrid imaging technology that in the near future might play a pivotal role in the clinical management of oncologic and inflammatory abdominopelvic diseases. Despite the still limited number of published clinical studies, PET/MRI has been proven to be at least equivalent to PET/CT and to standalone MRI in a variety of oncologic disease. Moreover, in selected and focused clinical studies, it has been proven to outperform current standard of care imaging, for example, in evaluating cholangiocarcinomas, liver metastases, untreated and treated rectal cancer. This has also had an impact on therapeuticmanagement in some studies. Therefore in some institutions, including those of the authors, PET/MRI is becoming the new standard imaging modality in staging treatment-naïve intrahepatic massforming cholangiocarcinomas and prior to complicated hepatic surgery.

[Hybrid imaging of the abdomen and pelvis. German version]. / Hybridbildgebung bei abdominellen Erkrankungen.

Accurate imaging is crucial for lesion detection in abdominal organs, for the noninvasive characterization of focal and diffuse abnormalities, and for surgical planning. To accomplish these tasks, several imaging modalities such as multidetector computer tomography (MDCT), magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) are used for abdominal imaging, providing important morphological, functional or metabolic information. More recently, PET/MRI has been gaining attention due to the possibility of combining high-resolution imaging with metabolic imaging. PET/MRI is a novel hybrid imaging technology that in the near future might play a pivotal role in the clinical management of oncologic and inflammatory abdominopelvic diseases. Despite the still limited number of published clinical studies, PET/MRI has been proven to be at least equivalent to PET/CT and to stand-alone MRI in a variety of oncologic disease. Moreover, in selected and focused clinical studies, it has been proven to outperform current standard of care imaging, for example, in evaluating cholangiocarcinomas, liver metastases, untreated and treated rectal cancer. This has also had an impact on therapeutic management in some studies. Therefore in some institutions, including those of the authors, PET/MRI is becoming the new standard imaging modality in staging treatment-naïve intrahepatic mass-forming cholangiocarcinomas and prior to complicated hepatic surgery.

Clinical impact of PET/MR in treated colorectal cancer patients.

PURPOSE: The primary aim of the present study was to evaluate if PET/MR induced management changes versus standard of care imaging (SCI) in treated colorectal cancer patients. The secondary aim was to assess the staging performance of PET/MR and of SCI versus the final oncologic stage. METHODS: Treated CRC patients who underwent PET/MR with 18F-FDG and SCI between January 2016 and October 2018 were enrolled in this retrospective study. Their medical records were evaluated to ascertain if PET/MR had impacted on their clinical management versus SCI. The final oncologic stage, as reported in the electronic medical record, was considered the true stage of disease. RESULTS: A total of 39 patients who underwent 42 PET/MR studies were included, mean age 56.7 years (range 39-75 years), 26 males, and 13 females. PET/MR changed clinical management 15/42 times (35.7%, standard error ± 7.4%); these 15 changes in management were due to upstaging in 9/42 (21.5%) and downstaging in 6/42 (14.2%). The differences in management prompted by SCI versus PET/MR were statistically significant, and PET/MR outperformed SCI (P value < 0.001; odds ratio = 2.8). In relation to the secondary outcome, PET/MR outperformed the SCI in accuracy of oncologic staging (P value = 0.016; odds ratio = 4.6). CONCLUSIONS: PET/MR is a promising imaging tool in the evaluation of treated CRC and might change the management in these patients. However, multicenter prospective studies with larger patient samples are required in order to confirm these preliminary results.

Assessing the Effect of Weight-Based Protocol Modifications to Lower Dose for CT-Guided Hepatic and Renal Tumor Radiofrequency Ablations.

OBJECTIVE: This study assessed radiation dose after CT-guided percutaneous radiofrequency ablations (RFAs) of hepatic and renal tumors and the effect of weight-based CT protocol modification for lowering overall dose in these procedures. MATERIALS AND METHODS: CT-guided RFA for renal and hepatic ablations performed from January 1, 2009, through December 31, 2009, were retrospectively reviewed (90 men and 48 women; age, 42-81 years). The radiation dose was recorded during each of the following steps: planning, performing, and postprocedure. Weight-based protocol modification changes in tube voltage and tube current were then applied to renal and hepatic ablations performed subsequently (18 men and 11 women; age, 48-82 years). Image quality, needle localization, lesion detection, ability to detect complications, and overall operator satisfaction were noted for each case (score, 1-5). Dose reduction after modification was then calculated. RESULTS: Retrospective analysis found a mean (± SD) overall CT dose index (CTDI) for CT-guided RFA to be 16.5 ± 2.3 mGy. After protocol modification, the mean CTDI decreased to 6.63 ± 0.67 mGy, a 59.6% reduction overall; for hepatic ablations, the reduction was 65.96% (p < 0.0001) and the reduction for renal ablations was 38.97% (p = 0.0153). Image quality analysis showed high operator satisfaction (3-5), including adequate needle localization (4-5), lesion visibility (3-5), and high performer confidence (4-5). Higher dose reduction was noted for patients weighing more than 180 lb (82 kg) (p < 0.0001). CONCLUSION: Simple weight-based CT protocol modifications can significantly reduce radiation dose during CT-guided percutaneous ablations in the liver and kidneys without significantly sacrificing image quality.

Renal Mass and Localized Renal Cancer: AUA Guideline.

PURPOSE: This AUA Guideline focuses on evaluation/counseling and management of adult patients with clinically localized renal masses suspicious for cancer, including solid-enhancing tumors and Bosniak 3/4 complex-cystic lesions. MATERIALS AND METHODS: Systematic review utilized research from the Agency for Healthcare Research and Quality and additional supplementation by the authors and consultant methodologists. Evidence-based statements were based on body of evidence strength Grade A/B/C (Strong/Moderate/Conditional Recommendations, respectively) with additional statements presented as Clinical Principles or Expert Opinions. RESULTS: Great progress has been made since the previous guidelines on management of localized renal masses were released (2009). The current guidelines provide updated, evidence-based recommendations regarding evaluation/counseling of patients with clinically localized renal masses, including the evolving role of renal mass biopsy. Given great variability of clinical, oncologic and functional characteristics, index patients are not utilized and the panel advocates individualized counseling/management. Management options (partial nephrectomy/radical nephrectomy/thermal ablation/active surveillance) are reviewed including recent data about comparative effectiveness and potential morbidities. Oncologic issues are prioritized while recognizing that functional outcomes are of great importance for survivorship for most patients with localized kidney cancer. A more restricted role for radical nephrectomy is recommended following well-defined selection criteria. Priority for partial nephrectomy is recommended for clinical T1a lesions, along with selective use of thermal ablation, particularly for tumors ≤3.0 cm. Important considerations for shared decision-making about active surveillance are explicitly defined. CONCLUSIONS: Several factors should be considered during counseling/management of patients with clinically localized renal masses, including general health/comorbidities, oncologic potential of the mass, pertinent functional issues and relative efficacy/potential morbidities of various management strategies.

MRI of Placenta Accreta, Placenta Increta, and Placenta Percreta: Pearls and Pitfalls.

OBJECTIVE: The purpose of this article is to provide a primer for radiologists performing MRI for suspected placenta accreta, illustrating normal and abnormal findings and diagnostic pitfalls. Appropriate examination indications and recommendations for optimizing image acquisition and interpretation are summarized. CONCLUSION: MRI increases the accuracy of the workup of high-risk patients and aids in multidisciplinary delivery planning to improve maternal outcome. Reader accuracy and confidence require adherence to examination performance, image interpretation criteria, and awareness of common pitfalls.

Evaluation of Quantitative PET/MR Enterography Biomarkers for Discrimination of Inflammatory Strictures from Fibrotic Strictures in Crohn Disease.

PURPOSE: To retrospectively evaluate positron emission tomography (PET)/magnetic resonance (MR) enterography for the differentiation of fibrotic strictures from inflammatory strictures in patients with Crohn disease. MATERIALS AND METHODS: This HIPAA-compliant retrospective study was approved by the institutional review board. Patients gave their written informed consent for study enrollment. PET/MR enterography images were evaluated in 19 patients with Crohn disease who had strictures that underwent surgical resection with pathologic confirmation. Two radiologists and a nuclear medicine physician in consensus evaluated the following bowel wall PET/MR enterography biomarkers: signal intensity (SI) on T2-weighted images, apparent diffusion coefficient (ADC), PET maximum standardized uptake value (SUVmax), SI on T2-weighted images × SUVmax, and ADC × SUVmax values at levels that corresponded to pathologic specimens. MR, PET, and hybrid PET/MR biomarkers were compared, and the performance for differentiation of inflammatory strictures from fibrotic strictures was assessed. Mixed-model regression analysis was used to compare the mean imaging parameters between groups; the P values were corrected for the five comparisons by using the Bonferroni method. RESULTS: Three of the PET/MR enterography biomarkers, SUVmax, SI on T2-weighted images × SUVmax, and ADC × SUVmax, showed significant differences in the fibrosis group compared with the fibrosis with active inflammation group and the active inflammation only group. The best discriminator between fibrosis and active inflammation was the combined PET/MR enterography biomarker ADC × SUVmax cutoff of less than 3000, which was associated with accuracy, sensitivity, and specificity values of 0.71, 0.67, and 0.73, respectively. CONCLUSION: PET/MR enterography offers a potential noninvasive technique for the differentiation of purely fibrotic strictures from mixed or inflammatory strictures. A hybrid biomarker that incorporates both MR and PET information performed better for stricture evaluation than either modality alone.

Catecholamine Surge during Image-Guided Ablation of Adrenal Gland Metastases: Predictors, Consequences, and Recommendations for Management.

PURPOSE: To identify retrospectively predictors of catecholamine surge during image-guided ablation of metastases to the adrenal gland. MATERIALS AND METHODS: Between 2001 and 2014, 57 patients (39 men, 18 women; mean age, 65 y ± 10; age range, 41-81 y) at two academic medical centers underwent ablation of 64 metastatic adrenal tumors from renal cell carcinoma (n = 27), lung cancer (n = 23), melanoma (n = 4), colorectal cancer (n = 3), and other tumors (n = 7). Tumors measured 0.7-11.3 cm (mean, 4 cm ± 2.5). Modalities included cryoablation (n = 38), radiofrequency (RF) ablation (n = 20), RF ablation with injection of dehydrated ethanol (n = 10), and microwave ablation (n = 4). Fisher exact test, univariate, and multivariate logistical regression analysis was used to evaluate factors predicting hypertensive crisis (HC). RESULTS: HC occurred in 31 sessions (43%). Ventricular tachycardia (n = 1), atrial fibrillation (n = 2), and troponin leak (n = 4) developed during HC episodes. HC was significantly associated with maximum tumor diameter ≤ 4.5 cm (odds ratio [OR], 26.36; 95% confidence interval [CI], 5.26-131.99; P < .0001) and visualization of normal adrenal tissue on CT or MR imaging before the procedure (OR, 8.38; 95% CI, 2.67-25.33; P < .0001). No HC occurred during ablation of metastases in previously irradiated or ablated adrenal glands. CONCLUSIONS: Patients at high risk of catecholamine surge during ablation of non-hormonally active adrenal metastases can be identified by the presence of normal adrenal tissue and tumor diameter ≤ 4.5 cm on pre-procedure CT or MR imaging.

Tumor Anatomy Scoring and Renal Function for Nephron-Sparing Treatment Selection in Patients With Small Renal Masses: A Microsimulation-Based Decision Analysis.

OBJECTIVE: The purpose of this article is to compare the effectiveness of a treatment algorithm for small renal tumors incorporating the nephrometry score, a renal tumor anatomy scoring system developed by urologists, with the current standard of uniformly recommended partial nephrectomy in patients with mild-to-moderate chronic kidney disease (CKD). MATERIALS AND METHODS: We developed a state-transition microsimulation model to project life expectancy (LE) in hypothetic patients with baseline mild or moderate CKD undergoing treatment of small renal masses. Our model incorporated the nephrometry score, which is predictive of postsurgical renal function loss. The two tested strategies were uniform treatment with partial nephrectomy and selective treatment based on nephrometry score and CKD stage, including percutaneous ablation for CKD stages 2 or 3a and intermediate-to-high nephrometry score or stage 3b CKD and any nephrometry score; otherwise, partial nephrectomy was assumed for other CKD stages and nephrometry scores. The model accounted for benign and malignant lesions, renal function decline, recurrence, and metastatic disease rates specific to each treatment, mortality by CKD stage, and comorbidities. Sensitivity analysis tested the stability of results when varying key parameters. RESULTS: Selective treatment with partial nephrectomy resulted in an average LE benefit of 0.48 year (95% interpercentile range, 0.42-0.54 year) in 65-year-old men and 0.37 year (95% interpercentile range, 0.30-0.43 year) in 65-year-old women relative to nondiscriminatory surgery, due to worsening CKD and cardiovascular mortality associated with partial nephrectomy. Model results were most sensitive to the rate of renal function decline and CKD-related mortality. CONCLUSION: Nephron-sparing treatment selection for small renal masses based on nephrometry score may improve LE in patients with mild or moderate CKD.

Role of percutaneous abscess drainage in the management of young patients with Crohn disease.

BACKGROUND: Intra-abdominal abscess is a common complication of Crohn disease in children. Prior studies, primarily in adults, have shown that percutaneous abscess drainage is a safe and effective treatment for this condition; however, the data regarding this procedure and indications in pediatric patients is limited. OBJECTIVE: Our aim was to determine the success rate of percutaneous abscess drainage for abscesses related to Crohn disease in pediatric patients with a focus on treatment endpoints that are relevant in the era of biological medical therapy. MATERIALS AND METHODS: We retrospectively reviewed 25 cases of patients ages ≤20 years with Crohn disease who underwent percutaneous abscess drainage. Technical success was defined as catheter placement within the abscess with reduction in abscess size on post-treatment imaging. Clinical success was defined as (1) no surgery within 1 year of drainage or (2) surgical resection following drainage with no residual abscess at surgery or on preoperative imaging. Multiple clinical parameters were analyzed for association with treatment success or failure. RESULTS: All cases were classified as technical successes. Nineteen cases were classified as clinical successes (76%), including 7 patients (28%) who required no surgery within 1 year of percutaneous drainage and 12 patients (48%) who had elective bowel resection within 1 year. There was a statistically significant association between resumption of immunosuppressive therapy within 8 weeks of drainage and both clinical success (P < 0.01) and avoidance of surgery after 1 year (P < 0.01). CONCLUSION: Percutaneous abscess drainage is an effective treatment for Crohn disease-related abscesses in pediatric patients. Early resumption of immunosuppressive therapy is statistically associated with both clinical success and avoidance of bowel resection, suggesting a role for percutaneous drainage in facilitating prompt initiation of medical therapy and preventing surgical bowel resection.

Prospective trial with optical molecular imaging for percutaneous interventions in focal hepatic lesions.

PURPOSE: To demonstrate the clinical translation of optical molecular imaging (OMI) for the localization of focal hepatic lesions during percutaneous hepatic interventions. MATERIALS AND METHODS: Institutional review board approval was obtained for this prospective, single-center, HIPAA-compliant trial. Patients who were suspected of having hepatocellular carcinoma or liver metastases from colorectal cancer and were scheduled for percutaneous liver biopsy or thermal ablation were eligible for this study. Patients (n = 5) received 0.5 mg per kilogram of body weight of indocyanine green (ICG) intravenously 24 hours prior to their scheduled procedure in this study. Intraprocedurally, a handheld device composed of an endoscope that fits coaxially through a standard 17-gauge introducer needle was advanced into the liver, and real-time measurements of ICG fluorescence were obtained. A point-of-care fluorescence imaging system was used to image ICG fluorescence in biopsy samples. Target-to-background ratios (TBRs) were calculated by dividing the mean fluorescence intensity in the lesion by the mean fluorescence intensity in the adjacent liver parenchyma. The reference standard for determination of proper needle positioning in patients undergoing biopsy was final pathologic analysis of biopsy specimens or follow-up imaging. RESULTS: Intraprocedural OMI was successfully performed in six lesions (two lesions in patient 3) in five patients. The median size of the targeted lesions was 16 mm (range, 10-21 mm). Four of five biopsies (80%) yielded an accurate pathologic diagnosis, and one biopsy specimen showed benign liver parenchyma; both ablated lesions showed no residual disease 1 month after the procedure. The median overall added procedure time to perform OMI was 2 minutes. ICG was found to localize with TBRs greater than 2.0 (median, 7.9; range, 2.4-13.4) in all target lesions. No trial-related adverse events were reported. CONCLUSION: The clinical translation of OMI to percutaneous hepatic interventions was demonstrated.

Thermal ablation of colorectal liver metastases: a position paper by an international panel of ablation experts, The Interventional Oncology Sans Frontières meeting 2013.

OBJECTIVES: Previous attempts at meta-analysis and systematic review have not provided clear recommendations for the clinical application of thermal ablation in metastatic colorectal cancer. Many authors believe that the probability of gathering randomised controlled trial (RCT) data is low. Our aim is to provide a consensus document making recommendations on the appropriate application of thermal ablation in patients with colorectal liver metastases. METHODS: This consensus paper was discussed by an expert panel at The Interventional Oncology Sans Frontières 2013. A literature review was presented. Tumour characteristics, ablation technique and different clinical applications were considered and the level of consensus was documented. RESULTS: Specific recommendations are made with regard to metastasis size, number, and location and ablation technique. Mean 31 % 5-year survival post-ablation in selected patients has resulted in acceptance of this therapy for those with technically inoperable but limited liver disease and those with limited liver reserve or co-morbidities that render them inoperable. CONCLUSIONS: In the absence of RCT data, it is our aim that this consensus document will facilitate judicious selection of the patients most likely to benefit from thermal ablation and provide a unified interventional oncological perspective for the use of this technology. KEY POINTS: • Best results require due consideration of tumour size, number, volume and location. • Ablation technology, imaging guidance and intra-procedural imaging assessment must be optimised. • Accepted applications include inoperable disease due to tumour distribution or inadequate liver reserve. • Other current indications include concurrent co-morbidity, patient choice and the test-of-time approach. • Future applications may include resectable disease, e.g. for small solitary tumours.

Radiation exposure from CT-guided ablation of renal masses: effects on life expectancy.

OBJECTIVE. The purpose of this article is to project the effects of radiation exposure on life expectancy (LE) in patients who opt for CT-guided radiofrequency ablation (RFA) instead of surgery for renal cell carcinoma (RCC). MATERIALS AND METHODS. We developed a decision-analytic Markov model to compare LE losses attributable to radiation exposure in hypothetical 65-year-old patients who undergo CT-guided RFA versus surgery for small (≤ 4 cm) RCC. We incorporated mortality risks from RCC, radiation-induced cancers (for procedural and follow-up CT scans), and all other causes; institutional data informed the RFA procedural effective dose. Radiation-induced cancer risks were generated using an organ-specific approach. Effects of varying model parameters and of dose-reduction strategies were evaluated in sensitivity analysis. RESULTS. Cumulative RFA exposures (up to 305.2 mSv for one session plus surveillance) exceeded those from surgery (up to 87.2 mSv). In 65-year-old men, excess LE loss from radiation-induced cancers, comparing RFA to surgery, was 11.7 days (14.6 days for RFA vs 2.9 days for surgery). Results varied with sex and age; this difference increased to 14.6 days in 65-year-old women and to 21.5 days in 55-year-old men. Dose-reduction strategies that addressed follow-up rather than procedural exposure had a greater impact. In 65-year-old men, this difference decreased to 3.8 days if post-RFA follow-up scans were restricted to a single phase; even elimination of RFA procedural exposure could not achieve equivalent benefits. CONCLUSION. CT-guided RFA remains a safe alternative to surgery, but with decreasing age, the higher burden of radiation exposure merits explicit consideration. Dose-reduction strategies that target follow-up rather than procedural exposure will have a greater impact.

Image-guided Treatment in the Hepatobiliary System: Role of Imaging in Treatment Planning and Posttreatment Evaluation.

In the past decade, image-guided targeted treatments such as percutaneous ablation, intra-arterial embolic therapies, and targeted radiation therapy have shown substantial promise in management of hepatobiliary malignancies. Imaging is integral to patient selection, treatment delivery, and assessment of treatment effectiveness. Preprocedural imaging is crucial and allows local tumor staging, evaluation of surrounding structures, and selection of suitable therapeutic options and strategies for treatment delivery. Postprocedural imaging is required to monitor therapeutic success, detect residual or recurrent disease, and identify procedure-related complications to guide appropriate future therapy. Technical innovations in cross-sectional imaging techniques such as computed tomography (CT) and magnetic resonance (MR) imaging, combined with advances in image postprocessing and new types of contrast agents, allow precise morphologic assessment and functional evaluation of hepatobiliary tumors. Advanced postprocessing techniques such as image fusion and volumetric assessment not only facilitate procedural planning and treatment delivery but also enhance posttreatment imaging surveillance. In addition, molecular imaging techniques such as fluorodeoxyglucose positron emission tomography (PET), PET/CT, and PET/MR imaging offer opportunities to evaluate various physiologic properties of tumors.