Maureen P. Kohi

Clinical applications for magnetic resonance guided high intensity focused ultrasound (MRgHIFU): Present and future

It has been well known for decades that high intensity focused ultrasound (HIFU) generates heat in tissues resulting in coagulative necrosis. Implementation, however, has been slow, due to difficulties with finding an appropriate imaging modality that could not only guide treatment, but also provide real‐time thermal feedback. These problems have been overcome with the newest magnetic resonance‐guided high intensity focused ultrasound systems (MRgHIFU). With its superior spatial resolution enabling accurate image guidance coupled with its ability to provide real‐time thermography during treatments, MRI is moving further into the realm of therapeutics for oncologic patient care.

Pharmacologic management of mesenteric occlusive disease.

Mesenteric vascular disease has been diagnosed increasingly over the past 25 years. This rise in incidence has been attributed to the advanced mean age of the population, an increasing number of critically ill patients and a greater clinical recognition of the condition. Although surgical revascularization and resection has long been the standard of treatment, medical management can also play an important adjunctive role. Early diagnosis before irreversible bowel damage, which may occur within 6–8 hours after the insult, is necessary to improve survival and reduce morbidity. Even in the presence of irreversible bowel ischemia, perioperative medical treatment may reduce disease progression, enabling more limited bowel resection. This article outlines the appropriate pharmacologic management of ischemic disorders of the intestine, with an emphasis on the pharmacologic treatments presently being used in clinical practice and those being studied in the laboratory.

Caval Penetration by Retrievable Inferior Vena Cava Filters: A Retrospective Comparison of Option and Günther Tulip Filters

PURPOSE To compare the frequency of vena caval penetration by the struts of the Option and Günther Tulip cone filters on postplacement computed tomography (CT) imaging. MATERIALS AND METHODS All patients who had an Option or Günther Tulip inferior vena cava (IVC) filter placed between January 2010 and May 2012 were identified retrospectively from medical records. Of the 208 IVC filters placed, the positions of 58 devices (21 Option filters, 37 Günther Tulip filters [GTFs]) were documented on follow-up CT examinations obtained for reasons unrelated to filter placement. In cases when multiple CT studies were obtained after placement, each study was reviewed, for a total of 80 examinations. Images were assessed for evidence of caval wall penetration by filter components, noting the number of penetrating struts and any effect on pericaval tissues. RESULTS Penetration of at least one strut was observed in 17% of all filters imaged by CT between 1 and 447 days following placement. Although there was no significant difference in the overall prevalence of penetration when comparing the Option filter and GTF (Option, 10%; GTF, 22%), only GTFs showed time-dependent penetration, with penetration becoming more likely after prolonged indwelling times. No patient had damage to pericaval tissues or documented symptoms attributed to penetration. CONCLUSIONS Although the Günther Tulip and Option filters exhibit caval penetration at CT imaging, only the GTF exhibits progressive penetration over time.

Hepatotoxicity after transarterial chemoembolization and transjugular intrahepatic portosystemic shunt: Do two rights make a wrong?

PURPOSE To compare the rates of hepatotoxicity after transarterial chemoembolization for hepatocellular carcinoma (HCC) in patients with and without a transjugular intrahepatic portosystemic shunt (TIPS) who were stratified into comparable risk groups. MATERIALS AND METHODS A retrospective review of patients with HCC who were treated with transarterial chemoembolization between January 2005 and December 2009 was performed. Of 158 patients with comparable model for end-stage liver disease (MELD) scores, 10 had a patent TIPS. Hepatobiliary severe adverse events (SAEs) occurring after transarterial chemoembolization were documented. In addition, 1-year survival and liver transplantation rate after transarterial chemoembolization were calculated in each group. RESULTS The incidence of hepatobiliary SAEs after transarterial chemoembolization was nearly two times higher in patients with a TIPS (70%) than in patients without a TIPS (36%; P=.046). The liver transplantation rate 1 year after transarterial chemoembolization was 2.5 times higher in patients with a TIPS (80%) than in patients without a TIPS (32%; P=.004). There was no significant difference in 1-year survival between the two groups after transarterial chemoembolization. CONCLUSIONS Patients with HCC and a patent TIPS are more likely to develop significant hepatotoxicity after transarterial chemoembolization than comparable patients without a TIPS in place.

Correctly Using Sensitivity, Specificity, and Predictive Values in Clinical Practice: How to Avoid Three Common Pitfalls

OBJECTIVE Radiology is the specialty of imaging-based diagnostic tests. Understanding the science behind evaluating diagnostic test performance is essential for radiologists because we provide care to patients and interact with our colleagues. CONCLUSION Here, we review the key terminology used and common pitfalls encountered in the literature and in day-to-day discussions of diagnostic test performance.

PROMISe trial: a pilot, randomized, placebo-controlled trial of magnetic resonance guided focused ultrasound for uterine fibroids

OBJECTIVE To evaluate the feasibility of a full-scale placebo-controlled trial of magnetic resonance-guided focused ultrasound for fibroids (MRgFUS) and obtain estimates of safety and efficacy. DESIGN Pilot, randomized, placebo-controlled trial. SETTING University medical center. PATIENT(S) Premenopausal women with symptomatic uterine fibroids. INTERVENTION(S) Participants randomized in a 2:1 ratio to receive MRgFUS or placebo procedure. MAIN OUTCOME MEASURE(S) PRIMARY OUTCOME change in fibroid symptoms from baseline to 4 and 12 weeks after treatment assessed by the Uterine Fibroid Symptom Quality of Life Questionnaire (UFS-QOL); secondary outcome: incidence of surgery or procedures for recurrent symptoms at 12 and 24 months. RESULT(S) Twenty women with a mean age of 44 years (±standard deviation 5.4 years) were enrolled, and 13 were randomly assigned to MRgFUS and 7 to placebo. Four weeks after treatment, all participants reported improvement in the UFS-QOL: a mean of 10 points in the MRgFUS group and 9 points in the placebo group (for difference in change between groups). By 12 weeks, the MRgFUS group had improved more than the placebo group (mean 31 points and 13 points, respectively). The mean fibroid volume decreased 18% in the MRgFUS group with no decrease in the placebo group at 12 weeks. Two years after MRgFUS, 4 of 12 women who had a follow-up evaluation (30%) had undergone another fibroid surgery or procedure. CONCLUSION(S) Women with fibroids were willing to enroll in a randomized, placebo-controlled trial of MRgFUS. A placebo effect may explain some of the improvement in fibroid-related symptoms observed in the first 12 weeks after MRgFUS. CLINICAL TRIAL REGISTRATION NUMBER NCT01377519.

Periprocedural Outcomes Comparing Fibroid Embolization and Focused Ultrasound: a Randomized Controlled Trial and Comprehensive Cohort Analysis.

BACKGROUND: Uterine fibroids are a common problem for reproductive‐aged women, yet little comparative effectiveness research is available to guide treatment choice. Uterine artery embolization and magnetic resonance imaging–guided focused ultrasound surgery are minimally invasive therapies approved by the US Food and Drug Administration for treating symptomatic uterine fibroids. The Fibroid Interventions: Reducing Symptoms Today and Tomorrow study is the first randomized controlled trial to compare these 2 fibroid treatments. OBJECTIVE: The objective of the study was to summarize treatment parameters and compare recovery trajectory and adverse events in the first 6 weeks after treatment. STUDY DESIGN: Premenopausal women with symptomatic uterine fibroids seen at 3 US academic medical centers were enrolled in the randomized controlled trial (n = 57). Women meeting identical criteria who declined randomization but agreed to study participation were enrolled in a nonrandomized parallel cohort (n = 34). The 2 treatment groups were analyzed by using a comprehensive cohort design. All women undergoing focused ultrasound and uterine artery embolization received the same postprocedure prescriptions, instructions, and symptom diaries for comparison of recovery in the first 6 weeks. Return to work and normal activities, medication use, symptoms, and adverse events were captured with postprocedure diaries. Data were analyzed using the Wilcoxon rank sum test or χ2 test. Multivariable regression was used to adjust for baseline pain levels and fibroid load when comparing opioid medication, adverse events, and recovery time between treatment groups because these factors varied at baseline between groups and could affect outcomes. Adverse events were also collected. RESULTS: Of 83 women in the comprehensive cohort design who underwent treatment, 75 completed postprocedure diaries. Focused ultrasound surgery was a longer procedure than embolization (mean [SD], 405 [146] vs 139 [44] min; P <.001). Of women undergoing focused ultrasound (n = 43), 23 (53%) underwent 2 treatment days. Immediate self‐rated postprocedure pain was higher after uterine artery embolization than focused ultrasound (median [interquartile range], 5 [1–7] vs 1 [1–4]; P = .002). Compared with those having focused ultrasound (n = 39), women undergoing embolization (n = 36) were more likely to use outpatient opioid (75% vs 21%; P < .001) and nonsteroidal antiinflammatory medications (97% vs 67%; P < .001) and to have a longer median (interquartile range) recovery time (days off work, 8 [6–14] vs 4 [2–7]; P < .001; days until return to normal, 15 [10–29] vs 10 [10–15]; P = .02). There were no significant differences in the incidence or severity of adverse events between treatment arms; 86% of adverse events (42 of 49) required only observation or nominal treatment, and no events caused permanent sequelae or death. After adjustment for baseline pain and uterine fibroid load, uterine artery embolization was still significantly associated with higher opioid use and longer time to return to work and normal activities (P < .001 for each). Results were similar when restricted to the randomized controlled trial. CONCLUSION: Women undergoing uterine artery embolization have longer recovery times and use more prescription medications, but women undergoing focused ultrasound have longer treatment times. These findings were independent of baseline pain levels and fibroid load.

Radioembolization with 90 Y glass microspheres for the treatment of unresectable metastatic liver disease from chemotherapy-refractory gastrointestinal cancers: final report of a prospective pilot study

BACKGROUND This prospective pilot single-institution study was undertaken to document the feasibility, safety, and efficacy of radioembolization of liver-dominant metastatic gastrointestinal cancer using 90Y glass microspheres. METHODS Between June 2010 and October 2013, 42 adult patients (26 men, 16 women; median age 60 years) with metastatic chemotherapy-refractory unresectable colorectal (n=21), neuroendocrine (n=11), intrahepatic bile duct (n=7), pancreas (n=2), and esophageal (n=1) carcinomas underwent 60 lobar or segmental administrations of 90Y glass microspheres. Data regarding clinical and laboratory adverse events (AE) were collected prospectively for up to 5.5 years after radioembolization. Radiographic responses were evaluated using Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. Time to maximum response, response duration, progression-free survival (PFS) (hepatic and extrahepatic), and overall survival (OS) were measured. RESULTS Median target dose and activity were 109.4 Gy and 2.6 GBq per treatment session, respectively. Majority of clinical AE were grade 1 or 2 in severity. Patients with colorectal cancer had hepatic objective response rate (ORR) of 25% and a hepatic disease control rate (DCR) of 80%. Median PFS and OS were 1.0 and 4.4 months, respectively. Patients with neuroendocrine tumors (NET) had hepatic ORR and DCR of 73% and 100%, respectively. Median PFS was 8.9 months for this cohort. DCR and median PFS and OS for patients with cholangiocarcinoma were 86%, 1.1 months, and 6.7 months, respectively. CONCLUSIONS 90Y glass microspheres device has a favorable safety profile, and achieved prolonged disease control of hepatic tumor burden in a subset of patients, including all patients enrolled in the neuroendocrine cohort.

Imaging Predictors of Elevated Lung Shunt Fraction in Patients Being Considered for Yttrium-90 Radioembolization.

PURPOSE To identify imaging findings associated with elevated lung shunt fraction (LSF) in patients being considered for yttrium-90 ((90)Y) radioembolization. MATERIALS AND METHODS During the period 2009-2014, 152 consecutive patients underwent planning hepatic arteriography with technetium-99m ((99m)Tc) macroaggregated albumin (MAA) injection. Computed tomography (CT) or magnetic resonance imaging performed before the procedure for each patient was assessed for hepatic vein (HV) tumor thrombus or occlusion from external compression by tumor. When imaging was a multiphase CT scan (117 patients), the arterial phase was evaluated for evidence of early HV opacification (relative to unaffected HVs), indicating hepatic venous shunting. These factors were correlated with LSF determined by (99m)Tc-MAA imaging. RESULTS Median LSF was 6.7% (range, < 0.1%-71%), significantly higher for HCC (8.0% vs 6.3% for other tumors, P = .048). Larger tumor size was associated with higher LSF in univariate analysis (P = .001). There was high interobserver agreement for determining hepatic venous shunting (97%, κ = 0.847), which was associated with higher LSF (P < .001; 78% sensitivity, 93% specificity). Of 5 cases of HV tumor thrombus, all had high (> 20%) LSF (P < .001). HV occlusion was also associated with higher LSF (P = .039). Multivariate analysis confirmed that early HV opacification and either HV tumor thrombus or occlusion were associated with higher LSF. CONCLUSIONS Early HV opacification and HV tumor thrombus or occlusion on cross-sectional imaging performed before radioembolization are associated with elevated LSF, which may contraindicate or limit the dose delivered in (90)Y radioembolization. This information could be helpful during patient counseling for anticipating the most appropriate mode of liver-directed therapy.

Contrast Enhanced Ultrasound as a Radiation-Free Alternative to Fluoroscopic Nephrostogram for Evaluating Ureteral Patency

Purpose: We compared contrast enhanced ultrasound and fluoroscopic nephrostography in the evaluation of ureteral patency following percutaneous nephrolithotomy. Materials and Methods: This prospective cohort, noninferiority study was performed after obtaining institutional review board approval. We enrolled eligible patients with kidney and proximal ureteral stones who underwent percutaneous nephrolithotomy at our center. On postoperative day 1 patients received contrast enhanced ultrasound and fluoroscopic nephrostogram within 2 hours of each other to evaluate ureteral patency, which was the primary outcome of this study. Results: A total of 92 pairs of imaging studies were performed in 82 patients during the study period. Five study pairs were excluded due to technical errors that prevented imaging interpretation. Females slightly predominated over males with a mean ± SD age of 50.5 ± 15.9 years and a mean body mass index of 29.6 ± 8.6 kg/m2. Of the remaining 87 sets of studies 69 (79.3%) demonstrated concordant findings regarding ureteral patency for the 2 imaging techniques and 18 (20.7%) were discordant. The nephrostomy tube was removed on the same day in 15 of the 17 patients who demonstrated antegrade urine flow only on contrast enhanced ultrasound and they had no subsequent adverse events. No adverse events were noted related to ultrasound contrast injection. While contrast enhanced ultrasound used no ionizing radiation, fluoroscopic nephrostograms provided a mean radiation exposure dose of 2.8 ± 3.7 mGy. Conclusions: A contrast enhanced ultrasound nephrostogram can be safely performed to evaluate for ureteral patency following percutaneous nephrolithotomy. This imaging technique was mostly concordant with fluoroscopic findings. Most discordance was likely attributable to the higher sensitivity for patency of contrast enhanced ultrasound compared to fluoroscopy.