J. Titano

Outcomes of Radioembolization in the Treatment of Hepatocellular Carcinoma with Portal Vein Invasion: Resin versus Glass Microspheres

PURPOSE To compare outcomes of yttrium-90 radioembolization performed with resin-based ((90)Y-resin) and glass-based ((90)Y-glass) microspheres in the treatment of hepatocellular carcinoma (HCC) with associated portal vein invasion. MATERIALS AND METHODS A single-center retrospective review (January 2005-September 2014) identified 90 patients ((90)Y-resin, 21; (90)Y-glass, 69) with HCC and ipsilateral portal vein thrombosis (PVT). Patients were stratified according to age, sex, ethnicity, Child-Pugh class, Eastern Cooperative Oncology Group status, α-fetoprotein > 400 ng/mL, extent of PVT, tumor burden, and sorafenib therapy. Outcome variables included clinical and laboratory toxicities (Common Terminology Criteria Adverse Events, Version 4.03), imaging response (modified Response Evaluation Criteria in Solid Tumors), time to progression (TTP), and overall survival (OS). RESULTS Grade 3/4 bilirubin and aspartate aminotransferase toxicities developed at a 2.8-fold (95% confidence interval [CI], 1.3-6.1) and 2.6-fold (95% CI, 1.1-6.1) greater rate in the (90)Y-resin group. The disease control rate was 37.5% in the (90)Y-resin group and 54.5% in the (90)Y-glass group (P = .39). The median (95% CI) TTP was 2.8 (1.9-4.3) months in the (90)Y-resin group and 5.9 (4.2-9.1) months in the (90)Y-glass group (P = .48). Median (95% CI) survival was 3.7 (2.3-6.0) months in the (90)Y-resin group and 9.4 (7.6-15.0) months in the (90)Y-glass group (hazard ratio, 2.6; 95% CI, 1.5-4.3, P < .001). Additional multivariate predictors of improved OS included age < 65 years, Eastern Cooperative Oncology Group status < 1, α-fetoprotein ≤ 400 ng/mL, and unilobar tumor distribution. CONCLUSIONS Imaging response of (90)Y treatment in patients with HCC and PVT was not significantly different between (90)Y-glass and (90)Y-resin groups. Lower toxicity and improved OS were observed in the (90)Y-glass group.

Tailoring the Endovascular Management of Transplant Renal Artery Stenosis

In this study we analyze the different types of endovascular interventions (EVIs) in de novo transplant renal artery stenosis (TRAS) and its anatomical subtypes to examine any variation in recovery of allograft function, blood pressure control, EVI patency and allograft survival with respect to EVI type (DES: drug‐eluting stent, BMS: bare‐metal stent, PTA: percutaneous transluminal angioplasty). Forty‐five patients underwent a total of 50 primary EVIs (DES: 18, BMS: 26, PTA: 6). Patients were stratified according to medical co‐morbidities, graft characteristics, biopsy results, clinical presentation and TRAS anatomic subtypes (anastomotic: 26, postanastomotic: 17, bend‐kink: 2). There was significant improvement in allograft function and mean arterial blood pressure (MAP) control across all interventions (pre‐EVI‐creatinine [CR]: 2.8 ± 1.4, post‐EVI‐Cr: 2.1 ± 0.7, p < 0.001; pre‐EVI‐MAP: 117 ± 16, post‐EVI‐MAP: 112 ± 17, p = 0.03) with no significant difference among EVI types. There was no significant difference in allograft survival with respect to EVI type. Patency was significantly higher in EVIs performed with DES and BMS compared to PTA (p = 0.001). In the postanastomotic TRAS subtype, patency rates were significantly higher in DES compared to BMS (p = 0.012) in vessels of comparable reference diameter (≤5 mm).

Radiation Segmentectomy versus TACE Combined with Microwave Ablation for Unresectable Solitary Hepatocellular Carcinoma Up to 3 cm: A Propensity Score Matching Study

Purpose To compare the outcomes of radiation segmentectomy (RS) and transarterial chemoembolization (TACE) combined with microwave ablation (MWA) in the treatment of unresectable solitary hepatocellular carcinoma (HCC) up to 3 cm. Materials and Methods This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. From January 2010 to June 2015, a total of 417 and 235 consecutive patients with HCC underwent RS and TACE MWA, respectively. A cohort of 121 patients who had not previously undergone local-regional therapy (RS, 41; TACE MWA, 80; mean age, 65.4 years; 84 men [69.4%]) and who had solitary HCC up to 3 cm without vascular invasion or metastasis was retrospectively identified. Outcomes analyzed included procedure-related complications, laboratory toxicity levels, imaging response, time to progression (TTP), 90-day mortality, and survival. Propensity score matching was conducted by using a nearest-neighbor algorithm (1:1) to account for pretreatment clinical, laboratory, and imaging covariates. Postmatching statistical analysis was performed with conditional logistic regression for binary outcomes and the stratified log-rank test for time-dependent outcomes. Results Before matching, the complication rate was 8.9% and 4.9% in the TACE MWA and RS groups, respectively (P = .46). The overall complete response (CR) rate was 82.9% for RS and 82.5% for TACE MWA (odds ratio, 1.0; 95% confidence interval [CI]: 0.4, 2.8; P = .95). There were 41 (RS, 11; TACE MWA, 30) instances of progression occurring after an initial CR, of which 10 (24%) were classified as target progression (RS, one; TACE MWA, nine). Median overall TTP was 11.1 months (95% CI: 8.8 months, 25.6 months) in the RS group and 12.1 months (95% CI: 7.7 months, 19.1 months) in the TACE MWA group (P > .99). After matching, the overall CR rate (P = .94), TTP (P = .83), and overall survival (P > .99) were not significantly different between the two groups. The 90-day postoperative mortality rate was 0% in both groups. Conclusion Imaging response and progression outcomes of patients with solitary HCC up to 3 cm treated with RS were not significantly different when compared with those of patients treated with TACE MWA.

Transradial access for visceral endovascular interventions in morbidly obese patients: safety and feasibility

Purpose Transradial access (TRA) has been shown to lower morbidity and bleeding complications compared to transfemoral access in percutaneous coronary interventions. Morbid obesity, commonly defined as a body mass index (BMI) ≥40 kg/m2, has been shown to be a risk factor for access site complications irrespective of access site. This study evaluates the safety and feasibility of performing visceral endovascular interventions in morbidly obese patients via TRA. Methods Procedural details, technical success, and 30-day major and minor access site, bleeding, and neurological adverse events were prospectively recorded in a database of 1057 procedures performed via the radial artery. From this database we identified 22 visceral interventions performed with TRA in 17 morbidly obese patients (age: 53 ± 11 years, female: 71%) with a median BMI of 42.7 kg/m2. Results Interventions included radio-embolization (n = 7, 31.8%), chemo-embolization (n = 6, 27.3%), uterine fibroid embolization (n = 4, 18.2%), renal embolization (n = 2, 9.1%), hepatic embolization (n = 1, 4.5%), lumbar artery embolization (n = 1, 4.5%), and renal angioplasty (n = 1, 4.5%). The technical success was 100%. There were no major or minor adverse access site, bleeding, or neurological complications at 30 days. Conclusions This study suggests visceral endovascular interventions performed in morbidly obese patients are safe and feasible.

Natural Language–based Machine Learning Models for the Annotation of Clinical Radiology Reports

Purpose To compare different methods for generating features from radiology reports and to develop a method to automatically identify findings in these reports. Materials and Methods In this study, 96 303 head computed tomography (CT) reports were obtained. The linguistic complexity of these reports was compared with that of alternative corpora. Head CT reports were preprocessed, and machine-analyzable features were constructed by using bag-of-words (BOW), word embedding, and Latent Dirichlet allocation-based approaches. Ultimately, 1004 head CT reports were manually labeled for findings of interest by physicians, and a subset of these were deemed critical findings. Lasso logistic regression was used to train models for physician-assigned labels on 602 of 1004 head CT reports (60%) using the constructed features, and the performance of these models was validated on a held-out 402 of 1004 reports (40%). Models were scored by area under the receiver operating characteristic curve (AUC), and aggregate AUC statistics were reported for (a) all labels, (b) critical labels, and (c) the presence of any critical finding in a report. Sensitivity, specificity, accuracy, and F1 score were reported for the best performing models (a) predictions of all labels and (b) identification of reports containing critical findings. Results The best-performing model (BOW with unigrams, bigrams, and trigrams plus average word embeddings vector) had a held-out AUC of 0.966 for identifying the presence of any critical head CT finding and an average 0.957 AUC across all head CT findings. Sensitivity and specificity for identifying the presence of any critical finding were 92.59% (175 of 189) and 89.67% (191 of 213), respectively. Average sensitivity and specificity across all findings were 90.25% (1898 of 2103) and 91.72% (18 351 of 20 007), respectively. Simpler BOW methods achieved results competitive with those of more sophisticated approaches, with an average AUC for presence of any critical finding of 0.951 for unigram BOW versus 0.966 for the best-performing model. The Yule I of the head CT corpus was 34, markedly lower than that of the Reuters corpus (at 103) or I2B2 discharge summaries (at 271), indicating lower linguistic complexity. Conclusion Automated methods can be used to identify findings in radiology reports. The success of this approach benefits from the standardized language of these reports. With this method, a large labeled corpus can be generated for applications such as deep learning.

Automated deep-neural-network surveillance of cranial images for acute neurologic events

Rapid diagnosis and treatment of acute neurological illnesses such as stroke, hemorrhage, and hydrocephalus are critical to achieving positive outcomes and preserving neurologic function—‘time is brain’1–5. Although these disorders are often recognizable by their symptoms, the critical means of their diagnosis is rapid imaging6–10. Computer-aided surveillance of acute neurologic events in cranial imaging has the potential to triage radiology workflow, thus decreasing time to treatment and improving outcomes. Substantial clinical work has focused on computer-assisted diagnosis (CAD), whereas technical work in volumetric image analysis has focused primarily on segmentation. 3D convolutional neural networks (3D-CNNs) have primarily been used for supervised classification on 3D modeling and light detection and ranging (LiDAR) data11–15. Here, we demonstrate a 3D-CNN architecture that performs weakly supervised classification to screen head CT images for acute neurologic events. Features were automatically learned from a clinical radiology dataset comprising 37,236 head CTs and were annotated with a semisupervised natural-language processing (NLP) framework16. We demonstrate the effectiveness of our approach to triage radiology workflow and accelerate the time to diagnosis from minutes to seconds through a randomized, double-blinded, prospective trial in a simulated clinical environment.A deep-learning algorithm is developed to provide rapid and accurate diagnosis of clinical 3D head CT-scan images to triage and prioritize urgent neurological events, thus potentially accelerating time to diagnosis and care in clinical settings.

Outcomes of radioembolization for unresectable hepatocellular carcinoma in patients with marginal functional hepatic reserve

PURPOSE To evaluate the outcomes of radioembolization (RE) as a therapy for unresectable hepatocellular carcinoma (HCC) in patients with marginal functional hepatic reserve. METHODS A retrospective review of 471 patients (1/2010-7/2015) treated with RE (Therasphere, BTG, UK) was performed. A total of 36 patients (mean age: 66.1±9.3, male: 86.1%) underwent therapy for HCC with a MELD≥15 (median: 16, range: 15-22). Baseline demographics of the study cohort were as follows: etiology (HCV: 26, 72.2%), cirrhosis (n=32, 88.9%), ECOG 0 (n=16, 44.4%), Child-Pugh class (A=15, B=19, C=2), unilobar distribution (n=27, 75%), AFP>200 (n=11, 30.6%), portal vein thrombosis (PVT, n=7, 19.4%), metastasis (n=3, 8.3%). Outcomes analyzed included CTCAEv4.03 laboratory toxicities (120-day), imaging response (mRECIST), progression-free survival (PFS), and overall survival (OS). RESULTS A total of 42 treatments were performed with mean dose of 2.02±1.23GBq. The cumulative grade 3/4 toxicity was 28% overall and 21% for bilirubin at 120-days. The objective response and disease control rates were 48.3% (14/29) and 69% (20/29) respectively. The median (95% CI) PFS was 5.9 (4.4-7.7) months. Ten (27.8%) patients received additional locoregional therapy at a median (IQR) of 138 (102-243) days post RE. The mean (95% CI) OS was 21.9 (14.8-29.0) months. The absence of PVT was associated with improved OS (p=0.005) Disease control at 90-days was also associated with an OS benefit (p=0.037). CONCLUSIONS Patients with unresectable HCC and marginal functional hepatic reserve treated with RE had favorable objective response and disease control rates, both predictive of overall survival.

Interventional Oncology: Treatment of primary liver tumors and liver metastases. Part I: Nuclear medicine techniques (all about spheres)

Y-90 radioembolization is an increasingly utilized treatment for both primary and metastatic malignancy in the liver. Understanding the biophysical properties, dosing concerns, and imaging appearance of this treatment is important for interventional radiologists and nuclear medicine physicians to provide important therapy. Y-90 radioembolization is efficacious and safe, although the possibility of complications does exist. This article provides a comprehensive in-depth discussion about the indications for Y-90 radioembolization, reviews the role of preprocedural angiography and MAA scans, illustrates different dosing techniques, compares and contrasts resin and glass microspheres, and confers potential complications.90Y radioembolization is an increasingly used treatment for both primary and metastatic malignancy in the liver. Understanding the biophysical properties, dosing concerns, and imaging appearance of this treatment is important for interventional radiologists and nuclear medicine physicians to provide important therapy. 90Y radioembolization is efficacious and safe, although the possibility of complications does exist. This article provides a comprehensive in-depth discussion about the indications for 90Y radioembolization, reviews the role of preprocedural angiography and 99mTc-macroaggregated albumin scans, illustrates different dosing techniques, compares and contrasts resin and glass microspheres, and describes potential complications.

Transarterial Chemoembolization Outcomes in Downstaging Hepatocellular Carcinoma Patients beyond the Milan Criteria

Purpose In this study, we evaluated outcomes of transarterial chemoembolization (TACE) for tumor downstaging in patients with hepatocellular carcinoma (HCC) beyond Milan criteria. Material and Methods From 1 January 2008 to 1 January 2013, a total of 564 patients with a diagnosis of HCC were listed for liver transplantation. Patients included in the study were determined to be outside of the Milan criteria but within the University of California-San Fransisco (UCSF) downstaging criteria at the time of diagnosis and subsequently underwent either conventional transarterial chemoembolization (c-TACE) or drug-eluting bead TACE (DEB-TACE). Patients who underwent previous therapies at the time of intervention were excluded. The primary outcome variable was overall survival. Secondary outcome variables included effectiveness of TACE at tumor downstaging, progression-free survival prior to transplant, and disease recurrence after transplant. Results Seventeen patients (median age 58 years; 5 female, 12 male) met the criteria for inclusion in this study. Patients underwent a median (range) of 3 (1-6) TACE procedures (c-TACE 17; DEB-TACE 20). Downstaging to within the Milan criteria was successful in 13 patients (76%). Of the 13 patients who were successfully downstaged, 9 underwent liver transplantation (orthotopic 7; living donor 2), 1 remained on the transplant list within Milan criteria, 2 re-progressed beyond Milan criteria (79, 624 days), and 1 died without disease progression of septicemia after a complicated post-operative course following colectomy for pancolitis. Univarate analysis of survival (log-rank test) showed a survival benefit in downstaged vs. non-downstaged patients when censored for transplant (p = 0.004) and when uncensored (p = 0.001). There was disease-free survival in the 9 patients who underwent transplantation. There was one HCC recurrence observed 3.8 years post-transplant. Conclusions In our experience, transarterial chemoembolization is effective at downstaging patients with T3 disease to within the Milan criteria with favorable post-transplant disease free survival.