Siddharth A. Padia

Safety and Efficacy of Drug-eluting Bead Chemoembolization for Hepatocellular Carcinoma: Comparison of Small-versus Medium-size Particles

PURPOSE To compare safety and imaging response with 100-300 μm and 300-500 μm doxorubicin drug-eluting bead (DEBs) to determine optimal particle size for chemoembolization of hepatocellular carcinoma (HCC). MATERIALS AND METHODS DEB chemoembolization using 100-300 μm (n = 39) or 300-500 μm (n = 22) LC beads loaded with 50 mg of doxorubicin was performed in 61 patients with HCC. Patient age, sex, etiology of liver disease, degree of underlying liver disease, tumor burden, and performance status were similar between the groups. All treatments were performed in a single session and represented the patients first treatment. Toxicities and imaging response in a single index tumor were analyzed using World Health Organization (WHO) and European Association for the Study of the Liver (EASL) criteria. RESULTS There was a significantly lower incidence of postembolization syndrome and fatigue after treatment in the 100-300 μm group (8% and 36%) versus the 300-500 μm group (40% and 70%) (100-300 μm group, P = .011; 300-500 μm group, P = .025). Mean change in tumor size was similar between the two groups based on WHO and EASL criteria and similar rates of objective response, but there was a trend toward a higher incidence of EASL complete response with 100-300 μm beads versus 300-500 μm beads (59% vs 36%; P = .114). CONCLUSIONS In DEB chemoembolization for treatment of HCC, 100-300 μm doxorubicin DEBs are favored over 300-500 μm doxorubicin DEBs because of lower rates of toxicity after treatment and a trend toward more complete imaging response at initial follow-up.

Comparison of Positron Emission Tomography and Bremsstrahlung Imaging to Detect Particle Distribution in Patients Undergoing Yttrium-90 Radioembolization for Large Hepatocellular Carcinomas or Associated Portal Vein Thrombosis

PURPOSE To compare positron emission tomography/computed tomography (PET/CT) imaging with bremsstrahlung single photon emission computed tomography (SPECT) in patients after yttrium-90 ((90)Y) microsphere radioembolization to assess particle uptake. MATERIALS AND METHODS This prospective study comprised patients with large (> 5 cm) hepatocellular carcinoma (HCC) or tumor-associated portal vein thrombus (PVT), or both. After radioembolization for HCC, patients underwent bremsstrahlung SPECT/CT and time-of-flight PET/CT imaging of (90)Y without additional tracer administration. Follow-up imaging and toxicity was analyzed. Imaging analyses of PET/CT and bremsstrahlung SPECT/CT were independently performed. RESULTS There were 13 patients enrolled in the study, including 7 with PVT. Median tumor diameter was 7 cm. PET/CT demonstrated precise localization of (90)Y particles in the liver, with specific patterns of uptake in large tumors. In cases of PVT, PET/CT showed activity within the PVT. When correlated to short-term follow-up imaging, areas of necrosis correlated with regions of uptake seen on PET/CT. Compared with bremsstrahlung imaging, PET/CT demonstrated at least comparable spatial resolution with less scatter. Quantitative uptake in nontreated regions of interest showed significantly reduced scatter with PET/CT versus SPECT/CT (1% vs 14%, P < .001). CONCLUSIONS Evaluation of (90)Y particle uptake with PET/CT potentially demonstrates high spatial resolution and low scatter compared with bremsstrahlung SPECT/CT. Confirmation of particles within PVT on PET/CT correlates with response on follow-up imaging and may account for the efficacy of radioembolization in patients with PVT.

Irreversible Electroporation Can Effectively Ablate Hepatocellular Carcinoma to Complete Pathologic Necrosis

PURPOSE To describe full explant pathology and radiographic correlation in patients with hepatocellular carcinoma (HCC) treated with irreversible electroporation (IRE) who subsequently underwent liver transplant. MATERIALS AND METHODS In a retrospective study, 6 patients who had undergone IRE for HCC and subsequent orthotopic liver transplant during the period 2011-2013 were evaluated. Of the 6 patients, 4 had Child-Pugh class A cirrhosis, and 2 had class B cirrhosis. Irreversible electroporation was performed for a single focal HCC with median tumor diameter of 22 mm (range, 6-26 mm). After IRE, follow-up multiphasic cross-sectional imaging was performed at 1 month and every 3 months thereafter until liver transplant. Mean time between IRE and transplant was 10 months (range, 3-17 mo). Assessment of imaging response was based on modified Response Evaluation Criteria In Solid Tumors. Liver explants were evaluated for necrosis and viable carcinoma in IRE-treated tumors. RESULTS After IRE, all tumors showed a complete response on follow-up imaging. Five tumors showed complete pathologic necrosis without any viable carcinoma, sharply demarcated from the surrounding hepatic parenchyma. Bile ducts within the treatment area were preserved. A single tumor treated with a bipolar IRE probe had < 5% viable carcinoma cells at the periphery. CONCLUSIONS This study demonstrates the efficacy of IRE for HCC based on pathologic evaluation and correlation to radiologic findings.

Standards of PracticeTranscatheter Therapy for Hepatic Malignancy: Standardization of Terminology and Reporting Criteria

The field of interventional oncology includes tumor ablation as well as the use of transcatheter therapies such as embolization, chemoembolization, and radioembolization. Terminology and reporting standards for tumor ablation have been developed. The development of standardization of terminology and reporting criteria for transcatheter therapies should provide a similar framework to facilitate the clearest communication among investigators and provide the greatest flexibility in comparing established and emerging technologies. An appropriate vehicle for reporting the various aspects of catheter directed therapy is outlined, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings. Methods for standardizing the reporting of outcomes toxicities, complications, and other important aspects that require attention when reporting clinical results are addressed. It is the intention of the group that adherence to the recommendations will facilitate achievement of the group’s main objective: improved precision and communication for reporting the various aspects of transcatheter management of hepatic malignancy that will translate to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes.

Pediatric abdominal and pelvic trauma: safety and efficacy of arterial embolization.

PURPOSE Although transcatheter embolization is a well established technique to treat adults in the trauma setting, evidence is lacking in the pediatric population. This study assesses the safety and efficacy of arterial embolization for blunt abdominal and pelvic trauma in the pediatric population. MATERIALS AND METHODS A retrospective review of abdominal and pelvic angiograms in 97 pediatric patients with blunt trauma was conducted over an 11-year period. Abdominal angiography and embolization was performed for ongoing hepatic, renal, splenic, or nonvisceral retroperitoneal injury. Pelvic angiography was performed in the setting of pelvic fracture with ongoing pelvic hemorrhage. Complications and clinical success rates of these procedures were assessed. RESULTS Of the 97 pediatric patients who underwent angiography for acute abdominal or pelvic trauma, 54 (56%) required embolization involving 62 separate sites. Injury severity score greater than 15 was present in 94% of patients. Targets of embolization included the pelvis (n = 39), liver (n = 8), kidney (n = 7), spleen (n = 6), and retroperitoneum (n = 2). Effective hemorrhage control was achieved in 47 patients (87%). Overall mortality rate was 22% (12 of 54), with most deaths related to traumatic brain injury. Five complications occurred in four patients (7%), including three major complications (hepatic abscess, bile leak, and urinary incontinence). CONCLUSIONS Angiography and embolization is relatively safe and potentially effective in the setting of abdominal and pelvic trauma in the pediatric population. Angiography with embolization should be considered in the treatment algorithm for this patient population.

Irreversible Electroporation in Patients with Hepatocellular Carcinoma: Immediate versus Delayed Findings at MR Imaging.

PURPOSE To assess the postprocedure findings of irreversible electroporation (IRE) in patients with hepatocellular carcinoma (HCC) at magnetic resonance (MR) imaging. MATERIALS AND METHODS This retrospective study was Institutional Review Board approved, and informed consent was waived. Twenty patients with HCC were treated with IRE over a 2.5-year period. The median patient age was 62 years, and 75% of patients had cirrhosis with a Child-Pugh score of A. The median tumor diameter was 2.0 cm (range, 1.0-3.3 cm). Contrast material-enhanced multiphase MR imaging was performed on postprocedure days 1 and 30 and every 90 days thereafter. Ablation zone sizes and signal intensities were compared between each time point for both T1- and T2-weighted images. Trends in signal intensity and tumor dimensions over time were quantified by using generalized linear models. RESULTS MR imaging appearances of treated tumors include a zone of peripheral enhancement with centripetal filling on delayed contrast-enhanced images. Compared with postprocedure day 1, every 90 days there is a decrease of 28.9% (mean, axis) in the size of the enhancing ablation zone. Over time, there is a trend toward decreasing signal intensity in the peripheral ablation zone on both T2-weighted (P = .01) and contrast-enhanced T1-weighted (P < .08) images. Conversely, the tumor itself typically has increased signal intensity on the same sequences. CONCLUSION IRE of HCC results in a large region of enhancement on immediate postprocedure MR images that, over time, involutes and is associated with decreasing signal intensity of the peripheral ablation zone. This phenomenon may represent resolution of the reversible penumbra.

Frequency of External Iliac Artery Branch Injury in Blunt Trauma: Improved Detection with Selective External Iliac Angiography

PURPOSE To assess the utility of selective external iliac artery (EIA) angiography and the frequency of injury to branches of the EIA in cases of blunt pelvic trauma. MATERIALS AND METHODS A retrospective review of pelvic angiograms in 66 patients with blunt pelvic trauma was conducted over a 12-month period. Pelvic and femur fracture patterns were correlated to the presence of EIA injury. Pelvic arteriography was compared versus selective EIA angiography for the detection of arterial injury. RESULTS Fifty-four of 66 patients (82%) exhibited pelvic arterial injury or elicited enough suspicion for injury to warrant embolization. Internal iliac artery embolization was performed in 50 of 66 (76%). EIA branch injury was identified in 11 of 66 patients (17%), and 10 were successfully embolized. EIA branch vessel injury was identified more frequently when there was ipsilateral intertrochanteric fracture (P = .07) or ipsilateral ilium fracture (P = .07). The sensitivity of nonselective pelvic angiography in the detection of EIA branch vessel injury was 45%. CONCLUSIONS EIA branch injury occurs in a substantial fraction of patients with blunt pelvic trauma who undergo pelvic angiography. Selective EIA angiography should be considered in all patients undergoing pelvic angiography in this situation.

Utilization of Angiography and Embolization for Abdominopelvic Trauma: 14 Years' Experience at a Level I Trauma Center

OBJECTIVE The objective of our study was to evaluate the long-term trends in the use of angiography and embolization for abdominopelvic injuries. MATERIALS AND METHODS Utilization rates for pelvic and abdominal angiography, arterial embolization, and CT were analyzed for trauma patients with pelvic fractures and liver and kidney injuries admitted to a level 1 trauma center from 1996 to 2010. Multivariable linear regression was used to evaluate trends in the use of angioembolization. RESULTS A total of 9145 patients were admitted for abdominopelvic injuries during the study period. Pelvic angiography decreased annually by 5.0% (95% CI, -6.4% to -3.7%) from 1996 to 2002 and by 1.8% (-2.4% to -1.2%) from 2003 to 2010. Embolization rates for these patients varied from 49% in 1997 to 100% in 2010. Utilization of pelvic CT on the day of admission increased significantly during this period. Abdominal angiography for liver and kidney injuries decreased annually by 3.3% (95% CI, -4.8% to -1.8%) and 2.0% (-4.3% to 0.3%) between 1996 and 2002 and by 0.8% (95% CI, -1.4% to -0.1%) and 0.9% (-2.0% to 0.1%) from 2003 to 2010, respectively. Embolization rates ranged from 25% in 1999 to 100% in 2010 for liver injuries and from 0% in 1997 to 80% in 2002 for kidney injuries. Abdominal CT for liver and kidney injuries on the day of admission also increased. CONCLUSION A significant decrease in angiography use for trauma patients with pelvic fractures, liver injuries, and kidney injuries from 1996 to 2010 and a trend toward increasing embolization rates among patients who underwent angiography were found. These findings reflect a declining role of angiography for diagnostic purposes and emphasize the importance of angiography as a means to embolization for management.

Multidisciplinary perspective of hepatocellular carcinoma: A Pacific Northwest experience.

Hepatocellular carcinoma (HCC) is the most rapidly increasing type of cancer in the United States. HCC is a highly malignant cancer, accounting for at least 14000 deaths in the United States annually, and it ranks third as a cause of cancer mortality in men. One major difficulty is that most patients with HCC are diagnosed when the disease is already at an advanced stage, and the cancer cannot be surgically removed. Furthermore, because almost all patients have cirrhosis, neither chemotherapy nor major resections are well tolerated. Clearly there is need of a multidisciplinary approach for the management of HCC. For example, there is a need for better understanding of the fundamental etiologic mechanisms that are involved in hepatocarcinogenesis, which could lead to the development of successful preventive and therapeutic modalities. It is also essential to define the cellular and molecular bases for malignant transformation of hepatocytes. Such knowledge would: (1) greatly facilitate the identification of patients at risk; (2) prompt efforts to decrease risk factors; and (3) improve surveillance and early diagnosis through diagnostic imaging modalities. Possible benefits extend also to the clinical management of this disease. Because there are many factors involved in pathogenesis of HCC, this paper reviews a multidisciplinary perspective of recent advances in basic and clinical understanding of HCC that include: molecular hepatocarcinogenesis, non-invasive diagnostics modalities, diagnostic pathology, surgical modality, transplantation, local therapy and oncological/target therapeutics.

Cone-Beam CT with Fluoroscopic Overlay Versus Conventional CT Guidance for Percutaneous Abdominopelvic Abscess Drain Placement

PURPOSE To compare technical success and procedure time for percutaneous abscess drain placement with fluoroscopic cone-beam computed tomography (CT) and two-axis needle guidance versus conventional CT guidance. MATERIALS AND METHODS A total of 85 consecutive patients undergoing abdominopelvic abscess drain placement guided by fluoroscopic cone-beam CT or conventional CT were retrospectively reviewed over a 2-year period. Forty-three patients underwent drain placement with cone-beam CT using XperGuide navigation and 42 underwent placement with conventional 64-slice CT. Patient characteristics, median abscess size (6.8 cm vs 7.8 cm; P = .14), and depth to abscess (7.2 cm vs 7.7 cm; P = .88) were similar between groups. RESULTS Technical success rates were 98% (42 of 43) in the cone-beam CT group and 100% (42 of 42) in the conventional CT group (P = .32), with a 10-F pigtail drainage catheter inserted in the majority of cases. There were no complications in either group. There was no significant difference in effective dose between groups (9.6 mSv vs 10.7 mSv; P = .30). Procedure times were significantly shorter in the cone-beam CT group (43 min vs 62 min; P = .02). In addition, during the study period, there was a gradual improvement in procedure time in the cone-beam CT group (50% reduction), whereas procedure time did not change for the conventional CT group. CONCLUSIONS Cone-beam CT guidance appears to be equivalent to conventional CT guidance for drain placement into medium-sized abdominopelvic collections, yielding similar technical success rates and radiation doses, with the additional benefit of reduced procedure times.