A study of pembrolizumab (pembro) in combination with Y90 radioembolization in patients (pts) with poor prognosis hepatocellular carcinoma (HCC)

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Background: HCC is an aggressive cancer as a sequela of cirrhosis. For pts with no extrahepatic metastases and well-compensated liver function, Y90 radioembolization is a therapeutic option. However, high-risk patients with macrovascular invasion (MVI) or multifocal disease treated with Y90 alone have a median time to progression of less than 6 months. Pembro is an anti-PD-1 monoclonal antibody that is FDA-approved for advanced HCC pts who have progressed on sorafenib. Given pre-clinical evidence that radiotherapy can increase PD-L1 expression and enhance tumoral T-cell recruitment, this study explored the safety and efficacy of pembro with Y90 radioembolization in pts with poor prognosis HCC. Methods: GI15-225 was a multi-center, single-arm study in poor prognosis HCC pts, defined as having multifocal disease, MVI, or diffuse disease. Eligible pts had disease amenable to 1-2 embolization procedures, Child Pugh A/B7 cirrhosis, no prior Y90 treatment; previous locoregional therapy and resection were allowed. Pts with extrahepatic mets were excluded. Treatment consisted of pembro 200mg every 3 weeks with standard dose Y90 performed 7-10 days after first dose of pembro. The primary objective was to estimate the progression free survival (PFS) rate at 6 months per RECIST 1.1; secondary endpoints included safety, time to progression (TTP), overall response rate (ORR) and overall survival (OS). Imaging was performed every 9 weeks. Results: A total of 29 pts were enrolled 10/23/17 to 11/24/20. Median age 66 years, 89% male, 7% Child’s Pugh B, and 47% with MVI. 27 pts were evaluable for primary endpoint having received Y90 and at least one dose of pembro. The 6-month PFS rate was 57.7% (95% CI 36.9 – 76.6). Median PFS was 9.95 months (95% CI 4.14 – 15.24) and median TTP was 9.95 months (95% 4.14 – 18.56). Median OS was 27.30 months (95% CI 10.15 – 39.52). The ORR was 30.8% (Table). Three patients (11%) have ongoing treatment response with one of these patients off treatment for 16 weeks. Most common treatment related grade 3-4 AEs were decreased lymphocytes (n=5), increased bilirubin (n=3), hypertension (n=3), ascites (n=2), and AST/ALT elevation (n=2). One pt experienced grade 5 toxicity of hepatic failure after receiving one dose of pembro and Y90 that was attributed to Y90 and disease progression. Conclusions: Concurrent administration of pembro with Y90 in pts with poor prognosis HCC demonstrated promising clinical activity with median TTP and OS that exceeds historical data with three patients having ongoing response. With a 6-month PFS rate of 57.7%, median OS of 27.30 months and an acceptable toxicity profile, the combination of checkpoint blockade and Y90 deserves further evaluation in larger randomized clinical trials. Clinical trial information: NCT03099564 .[Table: see text]

Yttrium-90 Radioembolization for the Treatment of Solitary, Unresectable HCC: The LEGACY Study

BACKGROUND AND AIMS

Locoregional therapies, including yttrium-90 radioembolization, play an important role in the treatment of unresectable HCC. The aim of the LEGACY (Local radioEmbolization using Glass Microspheres for the Assessment of Tumor Control with Y-90) study was to evaluate objective response rate (ORR) and duration of response (DoR) in patients with solitary unresectable HCC treated with yttrium-90 glass microspheres.

APPROACH AND RESULTS

LEGACY is a multicenter, single-arm, retrospective study conducted at three sites that included all eligible, consecutive patients with HCC treated with radioembolization between 2014 and 2017. Eligibility criteria included solitary HCC ≤ 8 cm, Child-Pugh A cirrhosis, and Eastern Cooperative Oncology Group performance status 0-1. Primary endpoints were ORR and DoR based on modified Response Evaluation Criteria in Solid Tumors in the treated area (localized), as evaluated by blinded, independent, central review. Radioembolization was performed with intent of ablative-level dosimetry in a selective fashion when possible. Overall survival was evaluated using Kaplan-Meier and multivariate Cox proportional hazards. Among the 162 patients included, 60.5% were Eastern Cooperative Oncology Group 0, and the median tumor size was 2.7 cm (range: 1-8) according to blinded, independent, central review. Radioembolization served as neoadjuvant therapy for transplantation or resection in 21.0% (34 of 162) and 6.8% (11 of 162) of patients, respectively, and as primary treatment for all others. Median follow-up time was 29.9 months by reverse Kaplan-Meier. ORR (best response) was 88.3% (CI: 82.4-92.4), with 62.2% (CI: 54.1-69.8) exhibiting a DoR ≥ 6 months. Three-year overall survival was 86.6% for all patients and 92.8% for those neoadjuvant patients with resected or transplanted liver.

CONCLUSIONS

In this multicenter study of radioembolization, clinical meaningful response rates and prolonged DoR were observed in the treatment of unresectable, solitary HCC ≤ 8 cm.

Recognizing and Managing Adverse Events in Y-90 Radioembolization

Transarterial radioembolization using yttrium-90 (Y-90) microspheres is an important therapy in the management of unresectable primary liver tumors or hepatic metastases. While radioembolization is generally well-tolerated, it is not free from adverse events, and familiarity with the prevention and treatment of radioembolization-specific complications is an important component of patient care. This article aims to review radioembolization-specific toxicities stratified by hepatic, extrahepatic, and systemic effects, with a focus on preventing and mitigating radioembolization-induced morbidity.

Inferior vena cava filter tilting between placement and retrieval is associated with caval diameter and need for complex retrieval techniques

PURPOSE

Inferior vena cava (IVC) filter tilt may lead to apex embedment and need for advanced retrieval techniques. This study assesses factors associated with filter tilt change over time and need for complex retrieval procedures.

MATERIALS AND METHODS

252 consecutive patients underwent retrievable IVC filter placement and removal at a single academic institution over 58 months. 182 (72.2%) patients met inclusion criteria. IVC filters included 168 (92.3%) Gunther Tulip and 14 (7.7%) Option filters. The primary outcome was medial-to-lateral IVC filter tilt change between placement and retrieval. Secondary outcomes included advanced retrieval technique use and multiple retrieval attempts. Independent variables included demographics, IVC diameter, filter hook position relative to the renal veins, and dwell time. Associations were determined using student's t-tests, ANOVA, and linear and logistic regressions.

RESULTS

Mean IVC diameter at placement was 19.2 ± 3.3 mm. Mean filter tilts at placement and retrieval were 6.1 ± 4.9° and 5.2 ± 5.0°, respectively. Mean tilt change was 5.0 ± 5.0°. Larger IVC diameter was associated with greater filter tilt change (p = 0.0004). While IVC diameter did not independently predict retrieval difficulty, greater tilt change and prolonged dwell time were associated with increased advanced retrieval technique use (p = 0.01 and 0.002, respectively). Results were unchanged in a subgroup analysis of patients treated with Gunther Tulip filters.

CONCLUSION

Larger IVC diameter predicts increased filter tilt change, which in turn is associated with challenging retrievals. Attention to IVC diameter during filter placement may anticipate tilt-related complications.

Life and Limb: Current Concepts in Endovascular Treatment of Extremity Trauma

Traumatic injury is the leading cause of death worldwide in younger patient populations and extremity trauma with associated vascular injury accounts for many trauma-related deaths. Iatrogenic injury is also a common cause of extremity vascular trauma and the incidence of iatrogenic injury will likely increase as endovascular techniques continue to become more ubiquitous. For many vascular injuries involving the extremities, surgical repair is viewed as the standard of care. Historically, endovascular techniques did not play a role in the treatment of these vascular injuries, rather they were utilized only as part of the diagnostic assessment; however, there is an increasing trend toward endovascular management of extremity vascular trauma. No validated, widely implemented algorithm to select patients for endovascular intervention exists. Transcatheter techniques, however, play an important role in the management of these patients. For arterial injuries, embolization can be used to rapidly achieve hemostasis if the vessel can be sacrificed. More advanced endovascular techniques such as stent-graft placement may be best employed in the context of isolated, proximal extremity injuries, although there is increasing literature supporting the use of advanced techniques for more distal arterial injuries. The management of peripheral venous trauma remains controversial; however, there is growing data describing successful endovascular management of some peripheral venous injuries. The purpose of this article is to review extremity vascular trauma, concepts of injury triage, endovascular techniques, and intraprocedural considerations.

Use of yttrium-90 (Y90) glass microspheres (TheraSphere) as neoadjuvant to transplantation/resection in hepatocellular carcinoma: Analyses from the LEGACY study

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Background: The objective of the LEGACY study was to assess the Objective Response Rate (ORR) and Duration of Response (DoR) following treatment with Yttrium-90 (Y90) glass microspheres in patients with unresectable solitary hepatocellular carcinoma (HCC). The objective of the analyses presented here are to evaluate ORR, DoR, and Overall Survival (OS) by transplant/resection status and to compare these outcomes with patients who did not go on to transplantation/resection after receiving treatment with Y90. Methods: LEGACY is a single-arm, multicenter, retrospective study of patients with unresectable HCC who received treatment with Y90 glass microspheres (TheraSphere) at one of three sites in the United States. LEGACY included all consecutive eligible patients who received treatment between January 2014 and December 2017 and met the eligibility criteria (Child-Pugh A; ECOG score of 0 or 1; BCLC A or C; and a solitary tumor > 2 and ≤8 cm). Primary efficacy endpoints included ORR and DoR. ORR included patients who achieved either a complete response or partial response based on localized mRECIST; response was assessed via blinded, independent, central review. Secondary endpoints include OS and number and type of subsequent treatments, including transplantation and resection. Results: Among all 162 patients enrolled in LEGACY, ORR was 72.2% (117/162; 95% CI = 64.9%, 78.5%); the majority of patients experienced DoR ≥ 6 months (89/117, 76.1%, 95% CI = 67.6%, 82.9%). Median follow-up time for all 162 patients enrolled in LEGACY was 29.9 months by reverse Kaplan-Meier analysis; 3-year OS was 86.6%. For 45/162 (27.8%) of patients, Y90 treatment served as neoadjuvant therapy; 34 went on to transplantation (21.0%) and 11 (6.8%) went on to resection. For neoadjuvant treatment, ORR was 80.0% (36/45, 95% CI = 66.2, 89.1), DoR ≥ 6 months was 30.6% (11/45, 95% CI = 18.0, 46.9), and 3-year OS was 92.8% (95% CI = 74.2, 98.2). Of these 45 patients, 35 patients achieved complete response (CR), 1 achieved partial response (PR), and 9/45 (20.0%) were deemed not evaluable as they underwent surgery prior to the 6-month mark and did not have imaging assessments post-Day 46. These nine patients were censored, lowering the DoR; however, histopathology revealed that 7/9 (77.8%) achieved complete pathologic necrosis, 1/9 (11.1%) had extensive pathologic necrosis, and 1 (11.1%) had partial pathologic necrosis. For the 117/162 (72.2%) patients who did not go on to surgical treatment, ORR was 91.5% (107/117, 95% CI = 85.0, 95.3), DoR ≥ 6 months was 72.9% (78/117, 95% CI = 63.8, 80.4), and 3-year OS was 83.5% (95% CI = 72.2, 90.5). Conclusions: Treatment of solitary unresectable HCC with Y90 glass microspheres provides strong ORR, DoR, and OS both as neoadjuvant therapy to transplantation/resection and as treatment in non-surgical candidates.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study

PURPOSE

To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply.

MATERIALS AND METHODS

This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed.

RESULTS

Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo).

CONCLUSIONS

Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

Transjugular intrahepatic portosystemic shunt creation via isolated persistent left superior vena cava: a case series

BACKGROUND

Isolated persistent left superior vena cava (PLSVC) is a rare vascular anatomic variant, which can be an incidental finding at the time of an endovascular procedure.

CASE PRESENTATION

This report describes the technical success, adverse events, and clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) creation via isolated PLSVC. Three adult patients with cirrhosis and isolated PLSVC underwent TIPS placement successfully with one major adverse event. Two patients required TIPS revision within 90 days. There were no deaths within 90 days.

CONCLUSIONS

TIPS creation via isolated PLSVC is feasible using standard techniques with a left jugular vein approach. Caution is warranted during the procedure to assess for any aberrant drainage pattern to the left atrium and to prepare for potentially challenging instrument navigation through the coronary sinus.

Fluoroscopically-guided interventions with radiation doses exceeding 5000 mGy reference point air kerma: a dosimetric analysis of 89,549 interventional radiology, neurointerventional radiology, vascular surgery, and neurosurgery encounters

Purpose

To quantify and categorize fluoroscopically-guided procedures with radiation doses exceeding 5000 mGy reference point air kerma (K_a,r). K_a,r > 5000 mGy has been defined as a “significant radiation dose” by the Society of Interventional Radiology. Identification and analysis of interventions with high radiation doses has the potential to reduce radiation-induced injuries.

Materials and methods

Radiation dose data from a dose monitoring system for 19 interventional suites and 89,549 consecutive patient encounters from January 1, 2013 to August 1, 2019 at a single academic institution were reviewed. All patient encounters with K_a,r > 5000 mGy were included. All other encounters were excluded (n = 89,289). Patient demographics, medical specialty, intervention type, fluoroscopy time (minutes), dose area product (mGy·cm²), and K_a,r (mGy) were evaluated.

Results

There were 260 (0.3%) fluoroscopically-guided procedures with K_a,r > 5000 mGy. Of the 260 procedures which exceeded 5000 mGy, neurosurgery performed 81 (30.5%) procedures, followed by interventional radiology (n = 75; 28.2%), neurointerventional radiology (n = 55; 20.7%), and vascular surgery (n = 49; 18.4%). The procedures associated with the highest K_a,r were venous stent reconstruction performed by interventional radiology, arteriovenous malformation embolization performed by neurointerventional radiology, spinal hardware fixation by neurosurgery, and arterial interventions performed by vascular surgery. Neurointerventional radiology had the highest mean K_a,r (7,799 mGy), followed by neurosurgery (7452 mGy), vascular surgery (6849 mGy), and interventional radiology (6109 mGy). The mean K_a,r for interventional radiology performed procedures exceeding 5000 mGy was significantly lower than that for neurointerventional radiology, neurosurgery, and vascular surgery.

Conclusions

Fluoroscopically-guided procedures with radiation dose exceeding 5000 mGy reference point air kerma are uncommon. The results of this study demonstrate that a large proportion of cases exceeding 5000 mGy were performed by non-radiologists, who likely do not receive the same training in radiation physics, radiation biology, and dose reduction techniques as radiologists.

Yttrium-90 radiation segmentectomy for hepatic metastases: A multi-institutional study of safety and efficacy

BACKGROUND AND OBJECTIVES

This study assessed the outcomes of Yttrium-90 (⁹⁰ Y) radiation segmentectomy for hepatic metastases unamenable to resection or ablation.

MATERIALS AND METHODS

Over 6 years, 36 patients with 53 tumors underwent segmental radioembolization. Patients were not candidates for surgical resection or thermal ablation. Malignancies included metastases from colorectal cancer (31%), neuroendocrine tumors (28%), sarcoma (19%), and others (22%). Eighty-one percent of patients had undergone prior treatment with systemic chemotherapy. Ongoing systemic chemotherapy was continued. Toxicity, tumor response, tumor progression, and survival were assessed.

RESULTS

The median tumor size was 3.6 cm (range 1.2-6.1 cm). Adverse event rates were low, with no hepatic-related Common Terminology Criteria for Adverse Events Grade 3 or 4 toxicity. Target tumor Response Evaluation Criteria in Solid Tumors disease control rate was 92% (28% partial response, 64% stable disease). For patients with enhancing tumors (n = 14), modified Response Evaluation Criteria in Solid Tumors target tumor objective response rate was 100%. During a median follow-up of 12 months, target tumor progression occurred in 28% of treated tumors. Overall survival was 96% and 83% at 6 and 12 months, respectively.

CONCLUSIONS

⁹⁰ Y radiation segmentectomy for hepatic metastases demonstrates high rates of tumor control and minimal toxicity. Radiation segmentectomy should be considered for patients with metastatic hepatic malignancy who are not candidates for surgical resection.

Clinical predictors of progression of a hepatic lesion from Li-RADS (LR) 3 to LR5 among patients (pts) at risk of hepatocellular carcinoma (HCC)

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Background: We sought to identify predictors of progression of LR3 lesions (i.e. indeterminate for HCC) to LR5 lesions (i.e. definitely HCC) on follow-up imaging among cirrhotic pts. Methods: Imaging reports with LR assignments were identified among pts seen at the University of Washington, 2013-2017. Cirrhotic pts with a LR3 lesion and follow-up scan within 1 year (yr) of LR3 lesion date were included (n = 313). Clinical features were abstracted from chart review. Survival analyses employing interval censoring were performed. Variables as potentially predictive of LR3 progression were identified in univariate analyses, with backwards elimination done (p < 0.05) to obtain the final multivariate model. Results: 20.4% of LR3 lesions progressed to LR5 within 1 yr; 73% were still LR3, 8% progressed to LR4. The population was predominantly male (61%), Caucasian (71%), older than 55 (63%). The most common cirrhotic etiologies were HCV (46.7%), alcohol (32.6%), and NASH (12.8%), not mutually exclusive. AFP at the time of LR3 scan was low if available (39% with AFP <5, 16% 5-10, 28% unknown). 22.7% had impaired liver function (ALBI grade 3); 19.5% lacked data to calculate ALBI grade. CT scan was the most common exam (56%). Multiple LR3 lesions were seen on 51% of scans. Most LR3 lesions were right sided (75%), < 1 cm (51%); 7% of lesions were > 2cm. Men (HR 2.0, p = 0.02), earlier scan yr (HR 0.47 per yr, p < 0.0001), older age (HR 1.42 per 15 yr, p = 0.047), lesion size (HR 1.21 for 2cm+, global p = 0.02) appeared as independent predictors of LR3 to LR5 progression based on the final model. Of 16 variables examined, men were more likely to have chronic HCV, history of alcohol use and less likely to have autoimmune hepatitis. No other differences were seen. In an a priori analysis, risk of male sex (HR 1.99, p = 0.03) persisted despite control for HCV, alcohol, age, race, scan yr, lesion size, and number of lesions. Conclusions: Identification of clinical factors associated with LR3 progression may allow for risk modeling tools that may assist in determining imaging frequency and timing of intervention. The increased risk among men vs women is not explained by clinical or radiographic features listed above.

The inferior vena cava: a pictorial review of embryology, anatomy, pathology, and interventions

The inferior vena cava (IVC) is the largest venous conduit below the diaphragm. Although this structure is often overlooked both clinically and radiographically, it can be involved in many different pathologic processes. A thorough understanding of the IVC will assist the radiologist in recognizing anatomic variants, identifying abnormalities, and providing accurate differential diagnoses. In this comprehensive pictorial review of the IVC, we depict embryology behind anatomic variants, present a wide range of pathology with a focus on diagnostic imaging, and describe relevant endovascular interventions.

Clinical predictors of radiographic progression of a hepatic lesion from Li-RADS 3 to Li-RADS 5 among a population of individuals at high risk of hepatocellular carcinoma

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Background: We sought to identify clinical predictors of radiographic progression of a Li-RADS (LR) 3 lesion (i.e. indeterminate for hepatocellular carcinoma (HCC)) to a LR 5 lesion (i.e. definitely HCC) among patients (pts) at high risk of HCC. Methods: Radiology reports from the University of Washington with an LR assignment, 2013-2017, were reviewed (5037 reports, 1954 patients(pts)). Pts with an LR 3 lesion, a follow-up scan within 1 year of date of LR 3 lesion detection, and radiographic evidence of cirrhosis OR a diagnosis of chronic HBV were included in the analysis. Results: Of the 167 pts, 38 (23%) progressed to LR 5 status, 10 progressed to LR 4, and 12 were downgraded to LR 1-2. The remaining 64% were unchanged at LR 3. Radiographic data including year of LR 3 detection (2013-2014 47%) and LR 3 imaging modality (CT 50.3%, MR 49.7%) were obtained. Clinical data were abstracted from medical record review, including sex (65% male), age (80% < 65), race (66% White), cirrhosis etiology (45% HCV, 27% EtOH, 22% NASH, 8% HBV), HCV genotype, HCV treatment status, AFP, and ALBI score (G2 54%, G3 16%, unk 15%). Variables of interest (age, sex, race, cirrhosis etiology, AFP, ALBI score, year of LR 3 detection, imaging modality) were included in proportional hazards modeling with the underlying time metric defined as time from LR 3 detection to date of LR 5 detection or date of last scan up to one year after LR 3 identification. Backwards elimination modeling was performed until remaining variables were associated with the outcome at a level of significance of p < 0.05 (Table 1). Among those with chronic HCV, risk of progression to LR 5 did not differ by HCV genotype (1a, 1b, 2, 3, other, unknown) or sustained viral response status at the time of LR 3 detection. Table 1: Multivariate hazard ratios (HR) and 95% confidence interval (CI) estimates. Conclusions: Chronic HCV, older age at LR 3 detection, earlier year of LR 3 detection, and male sex appear independently associated with risk of progression to LR 5. The identification of clinical factors associated with LR 3 progression may allow for the development of risk modeling tools to assist clinicians in determining frequency of follow-up imaging and optimal timing of intervention.[Table: see text]

A retrospective analysis of clinical outcomes among patients with infiltrative hepatocellular carcinoma (iHCC): A single institution study

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Background: iHCC is an aggressive disease with poorly characterized treatment outcomes. We sought to describe clinical and radiographic features of iHCC, describe overall survival (OS), and compare outcomes of sorafenib (SOR) use with a cohort of non-infiltrative hepatocellular carcinoma (niHCC) patients. Methods: Radiology reports from the University of Washington with an Li-RADS (LR) assignment, 2013-2017, were reviewed (5037 reports, 1954 patients (pts)) for terms indicative of iHCC. Results: : 102 cases were identified, with 43% arising from known niHCC. iHCC size is difficult to measure but when reported, median was 8cm (interquartile range 5-10cm). Other radiographic features: vascular invasion 72%, R lobe only 62%. Clinical data were obtained via medical record review. The cohort was primarily male (83%), White (65%), age > 55 (88%), HCV (74.5%), heavy alcohol use (67%). At diagnosis: BCLC stage C (76%), ALBI grade 2 (62%) and 3 (21%). Median OS after diagnosis was 5.7 months (m). 38 (37%) pts were too ill to receive therapy. OS for de novo iHCC and for iHCC arising from niHCC did not differ (7.5m vs 5.1m, p = NS). All niHCC pts who received SOR in any line of therapy were identified among pts with a LR 5 lesion in at least one of the aforementioned radiology reports, 2013-2017. Pts who received SOR on trial and/or combined with another agent were excluded. Clinical data for the 83 niHCC pts were abstracted and compared to the 25 iHCC pts who received SOR, any line of therapy. Based on χ2 analyses, the 2 groups did not differ by age, sex, race, BCLC stage at SOR initiation, ECOG status at SOR initiation, HCC etiology, ALBI grade at SOR initiation, or previous locoregional therapy. OS after initiation of SOR was 14.1m for niHCC, 10.5m for iHCC, p = NS. PFS after SOR was 3.7m for niHCC, 7m for iHCC, p = NS. AFP at the time of SOR initiation was higher in iHCC than niHCC (median 1331 vs 48, respectively, p = 0.004), with median %AFP change after 30 days -13% in iHCC and +6% in niHCC, p = NS. Decrease in AFP after 30 days of therapy was associated with improved OS among niHCC (21m versus 7m, p = 0.001) but not among iHCC pts (p = NS). Conclusions: iHCC is a poorly understood subset of HCC with underlying biology not well defined. Compared to niHCC, clinical outcomes with sorafenib do not appear to differ in this cohort. Future characterization of outcomes with Y-90 and immune checkpoint inhibitors is warranted.

An Interventionalist's Guide to Hemoptysis in Cystic Fibrosis

Massive hemoptysis occurs in a minority of patients with cystic fibrosis, with an annual incidence of 1%. Although rare, massive hemoptysis can be a severe and potentially fatal complication of this disease. Beyond the acute life-threatening event, hemoptysis in patients with cystic fibrosis has been associated with faster decline in lung function, accelerated need for lung transplant, and increased mortality. The bronchial arteries are the culprit vessels in over 90% of cases of hemoptysis. This normally quiescent vascular system undergoes remarkable hypertrophy, collateralization, and angiogenesis before the onset of hemoptysis, introducing numerous pitfalls for the interventionalist. However, in experienced hands, bronchial artery embolization is a safe and potentially lifesaving therapy. Preprocedural noninvasive imaging, specifically computed tomographic angiography, has been repeatedly validated for helping to localize the likely site of bleeding, characterizing pertinent arterial anatomy, and promoting efficient and effective intervention; it has been recommended for all stable patients with hemoptysis. Success in the angiographic suite requires a thorough understanding of normal and variant bronchial arterial anatomy, appropriate patient selection, and a meticulous embolization technique. A meticulous approach to imaging and intervention, conscientious of both visualized and nonvisualized collateral pathways and nontarget vessels, can minimize potentially devastating complications. This review summarizes the current literature, modern procedural techniques, and emerging controversies, serving to guide an evolving approach to management of patients with cystic fibrosis and hemoptysis. ^©RSNA, 2018.

Hepatotoxic Dose Thresholds by Positron-Emission Tomography After Yttrium-90 Radioembolization of Liver Tumors: A Prospective Single-Arm Observational Study

PURPOSE

To define a threshold radiation dose to non-tumoral liver from ⁹⁰Y radioembolization that results in hepatic toxicity using pair-production PET.

MATERIALS AND METHODS

This prospective single-arm study enrolled 35 patients undergoing radioembolization. A total of 34 patients (27 with HCC and 7 with liver metastases) were included in the final analysis. Of 27 patients with underlying cirrhosis, 22 and 5 patients were Child-Pugh A and B, respectively. Glass and resin microspheres were used in 32 (94%) and 2 (6%) patients, respectively. Lobar and segmental treatment was done in 26 (76%) and 8 (24%) patients, respectively. Volumetric analysis was performed on post-radioembolization time-of-flight PET imaging to determine non-tumoral parenchymal dose. Hepatic toxicity was evaluated up to 120 days post-treatment, with CTCAE grade ≤ 1 compared to grade ≥ 2.

RESULTS

The median dose delivered to the non-tumoral liver in the treated lobe was 49 Gy (range 0-133). A total of 15 patients had grade ≤ 1 hepatic toxicity, and 19 patients had grade ≥ 2 toxicity. Patients with a grade ≥ 2 change in composite toxicity (70.7 vs. 43.8 Gy), bilirubin (74.1 vs. 43.3 Gy), albumin (84.2 vs. 43.8 Gy), and AST (94.5 vs. 47.1 Gy) have significantly higher non-tumoral parenchymal doses than those with grade ≤ 1. Liver parenchymal dose and Child-Pugh status predicted grade ≥ 2 toxicity, observed above a dose threshold of 54 Gy.

CONCLUSION

Increasing delivered ⁹⁰Y dose to non-tumoral liver measured by internal pair-production PET correlates with post-treatment hepatic toxicity. The likelihood of toxicity exceeds 50% at a dose threshold of 54 Gy. ClinicalTrials.gov identifier: NCT02848638.

An Interventionist's Guide to Endocrine Consultations

Endocrinopathies are a heterogeneous group of disorders often resulting from pathologic sources of hormone production. When the clinical scenario, laboratory testing, and noninvasive imaging fail to aid confident identification of the source of hormone excess, endocrine venous sampling may localize obscure lesions to guide subsequent treatment. Knowledge of basic hormone signaling pathways, common pathophysiologic disruptions of these pathways, and serologic evaluation fosters informed conversations with referring physicians and effective patient selection. Success in the angiography suite requires familiarity with normal and variant anatomy of the multiple organs of the endocrine system, patient preparation, stimulation and sampling techniques, specimen handling, and results interpretation. ^©RSNA, 2017.

Toward consensus reporting of radiation-induced liver toxicity in the treatment of primary liver malignancies: Defining clinically relevant endpoints

BACKGROUND

Our purpose was to define the most clinically relevant "nonclassic" radiation-induced liver disease (RILD) endpoints in cirrhotic patients receiving stereotactic body radiation therapy or proton beam therapy for primary liver cancer.

METHODS AND MATERIALS

We retrospectively collected pretreatment, detailed toxicity (≤6 months posttreatment), and outcomes data from 48 patients. Deaths were examined for association with RILD. Univariate and multivariate Cox models defined significant predictors of overall survival (OS)/RILD-specific survival (RILD-SS).

RESULTS

With median follow-up of 13 months, 23 patients (48%) had an increase in Child-Pugh (CP) score (≥2, 25%) and 3 (6%) had ≥G3 transaminase elevation. Of 18 deaths, 6 were potentially ascribed to RILD. Univariate analysis showed that CP score increases of ≥1 and ≥2 and CP class change predicted OS, as did ≥G3 aspartate transaminase (AST) elevation and ≥1 Common Terminology Criteria for Adverse Events (CTCAE) AST toxicity grade change. On multivariate analysis, CP score increase of ≥2 and ≥1 CTCAE AST toxicity grade change were the strongest independent nonclassic RILD predictors of OS. For RILD-SS, CP score increases of ≥2, ≥grade 3 CTCAE alanine transaminase, and ≥grade 2 bilirubin elevations were predictive.

CONCLUSIONS

Increased CP score ≥2 strongly predicts for both OS and RILD-SS and should be reported in future studies along with transaminase elevations, which are also predictive of outcomes.

Yttrium-90 Radioembolization as a Salvage Treatment following Chemoembolization for Hepatocellular Carcinoma

PURPOSE

To determine safety and efficacy of yttrium-90 ((90)Y) transarterial radioembolization (TARE) in patients who have undergone chemoembolization for hepatocellular carcinoma.

MATERIALS AND METHODS

A retrospective study identified 40 patients (median age 61 y; range, 44-84 y) who underwent (90)Y mapping angiography and had undergone ≥ one prior chemoembolizations. There were 4 (10%) patients in Barcelona Clinic Liver Cancer stage A, 7 (17.5%) in stage B, and 29 (72.5%) in stage C; 28 (70%) were Child-Pugh class A and 12 (30%) were class B. Median tumor diameter was 4.2 cm (range, 1-11.6 cm). The most common indications for changing to TARE were tumor progression (35/40; 86%) and development of portal vein thrombus (15/40; 37.5%).

RESULTS

Of 40 patients, 29 (72.5%) underwent TARE; the most common reasons for not undergoing TARE were attenuated hepatic arteries (5/11), high pulmonary shunt (4/11), and poor arterial flow (2/11). Patients who underwent ≤ 4 chemoembolizations to the TARE target tended to be more likely to undergo TARE after mapping than patients who had > 4 chemoembolizations (P = .056). Most common grade ≥ 3 toxicities were fatigue (9/29; 31%) and biochemical alterations (bilirubin [3/29; 10.3%], albumin [4/29; 13.8%], aspartate aminotransferase [5/29; 17.2%]). Of 27 patients treated with TARE with follow-up, responses were 11 (41%) complete response, 5 (19%) partial response, 2 (7%) stable disease, and 9 (33%) progressive disease. Median progression-free survival and overall survival were 90 days and 257 days.

CONCLUSIONS

TARE is safe and effective salvage therapy in patients after chemoembolization. In patients who have undergone > 4 chemoembolizations to the (90)Y target, feasibility of TARE tends to be decreased.

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.

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.

Intra-Arterial Thrombolysis for Hepatic Artery Thrombosis following Liver Transplantation

PURPOSE

Hepatic artery thrombosis (HAT) is a major cause of morbidity and death following liver transplantation. The purpose of this study was to evaluate the safety and efficacy of intra-arterial thrombolysis (IAT) in liver transplant recipients with HAT.

MATERIALS AND METHODS

Adult liver transplant recipients who underwent attempted IAT for HAT were identified. This included patients with early and late HAT (occurring less than or greater than 30 d after transplantation). Records were reviewed to determine the rates of technical success, complications, surgical revascularization, repeat liver transplantation, and ischemic cholangiopathy.

RESULTS

Twenty-six patients underwent attempted thrombolysis, 13 of whom had early HAT. IAT was successfully initiated in 23 patients (88%), with a median IAT duration of 28 hours (range, 12-90 h). Recanalization was achieved in 12 patients (46%). Major complications were observed in 11 patients (42%). The early HAT group showed a trend toward increased major bleeding compared with the late HAT group (50% vs 9%; P = .07). Among 12 patients who had technically successful thrombolysis, five (42%) required surgical revascularization or repeat transplantation within 2 months. At 6 months after thrombolysis, 45% with unsuccessful recanalization avoided surgery or development of ischemic cholangiopathy, similar to the proportion in those who had successful recanalization (42%; P = .88).

CONCLUSIONS

Posttransplantation hepatic artery thrombolysis yields suboptimal results with a high complication rate, especially in early HAT. Even with successful restoration of flow, clinical outcomes are poor. Although thrombolysis may still be considered in view of the limited treatment options for HAT, awareness of potential complications and suboptimal success rate is essential.

Derivation of point of departure (PoD) estimates in genetic toxicology studies and their potential applications in risk assessment

Genetic toxicology data have traditionally been employed for qualitative, rather than quantitative evaluations of hazard. As a continuation of our earlier report that analyzed ethyl methanesulfonate (EMS) and methyl methanesulfonate (MMS) dose-response data (Gollapudi et al., 2013), here we present analyses of 1-ethyl-1-nitrosourea (ENU) and 1-methyl-1-nitrosourea (MNU) dose-response data and additional approaches for the determination of genetic toxicity point-of-departure (PoD) metrics. We previously described methods to determine the no-observed-genotoxic-effect-level (NOGEL), the breakpoint-dose (BPD; previously named Td), and the benchmark dose (BMD10 ) for genetic toxicity endpoints. In this study we employed those methods, along with a new approach, to determine the non-linear slope-transition-dose (STD), and alternative methods to determine the BPD and BMD, for the analyses of nine ENU and 22 MNU datasets across a range of in vitro and in vivo endpoints. The NOGEL, BMDL10 and BMDL1SD PoD metrics could be readily calculated for most gene mutation and chromosomal damage studies; however, BPDs and STDs could not always be derived due to data limitations and constraints of the underlying statistical methods. The BMDL10 values were often lower than the other PoDs, and the distribution of BMDL10 values produced the lowest median PoD. Our observations indicate that, among the methods investigated in this study, the BMD approach is the preferred PoD for quantitatively describing genetic toxicology data. Once genetic toxicology PoDs are calculated via this approach, they can be used to derive reference doses and margin of exposure values that may be useful for evaluating human risk and regulatory decision making.

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.

Diagnostic correlation between the expression of the DNA repair enzyme N-methylpurine DNA glycosylase and esophageal adenocarcinoma onset: a retrospective pilot study

EAC in its early stages, when it can potentially be cured, is rarely symptomatic and is associated with high mortality rates because in part of late-stage diagnosis. Given that DNA repair is an important contributory factor of early-stage malignancy, our study focused on the expression of the base excision repair enzyme N-methylpurine DNA glycosylase (MPG) in EAC disease onset. MPG messenger RNA (mRNA) expression levels were determined using quantitative reverse transcriptase polymerase chain reaction from a maximum of 72 patient samples. Immunohistochemistry was further utilized for the detection of MPG protein, and semiquantitative analysis performed using an H-score approach was carried out on a total of 130 archival tissue samples of different esophageal pathologies. Nuclear localized MPG protein was detected in all nonmalignant tissues derived from the enterohepatic system, with H-score values of 3.9-5.5 ± 0.4-1.0. In cancerous tissues derived from the enterohepatic system, a 9.5-fold increase in the level of MPG mRNA expression was specifically observed in the malignant regions located within the esophagus region. Further analysis revealed a 9- and 14-fold increase in MPG mRNA expression in EAC tumor, node, metastasis stages II and III, respectively, suggesting MPG expression to correlate with EAC disease progression. Immunohistochemistry analysis further showed a sevenfold significant increase in MPG protein expression in EAC tissues. Intriguingly, there was a fivefold significant decrease in nuclear localized MPG protein expression in tissues derived from Barrett's esophagus and low-grade dysplasia. Such findings highlight a complex regulatory pattern governing DNA glycosylase base excision repair initiation, as normal tissue undergoes Barrett's metaplasia and later dedifferentiates to EAC. Indeed, disease-stage-specific alterations in the expression of MPG may highlight a potential role for MPG in determining EAC onset and thus potentially be of clinical relevance for early disease detection and increased patient survival.

TNFα from classically activated macrophages accentuates epithelial to mesenchymal transition in obliterative bronchiolitis

Bronchiolitis obliterans syndrome is characterized by fibrotic obliteration of small airways which severely impairs graft function and survival after lung transplantation. Bronchial epithelial cells from the transplanted lung can undergo epithelial to mesenchymal transition and this can be accentuated by activated macrophages. Macrophages demonstrate significant plasticity and change phenotype in response to their microenvironment. In this study we aimed to identify secretory products from macrophages that might be therapeutic targets for limiting the inflammatory accentuation of epithelial to mesenchymal transition in bronchiolitis obliterans syndrome. TNFα, IL-1β and IL-8 are elevated in bronchoalveolar lavage from lung transplant patients prior to diagnosis of bronchiolitis obliterans syndrome. Classically activated macrophages secrete more TNFα and IL-1β than alternatively activated macrophages and dramatically accentuate TGF-β1-driven epithelial to mesenchymal transition in bronchial epithelial cells isolated from lung transplant patients. Blocking TNFα, but not IL-1β, inhibits the accentuation of epithelial to mesenchymal transition. In a pilot unblinded therapeutic intervention in five patients with progressive bronchiolitis obliterans syndrome, anti-TNFα treatment improved forced expiratory volume in 1 second and 6-min walk distances in four patients. Our data identify TNFα as a potential new therapeutic target in bronchiolitis obliterans syndrome deserving of a randomized placebo controlled clinical trial.

Quantitative approaches for assessing dose-response relationships in genetic toxicology studies

Genetic toxicology studies are required for the safety assessment of chemicals. Data from these studies have historically been interpreted in a qualitative, dichotomous "yes" or "no" manner without analysis of dose-response relationships. This article is based upon the work of an international multi-sector group that examined how quantitative dose-response relationships for in vitro and in vivo genetic toxicology data might be used to improve human risk assessment. The group examined three quantitative approaches for analyzing dose-response curves and deriving point-of-departure (POD) metrics (i.e., the no-observed-genotoxic-effect-level (NOGEL), the threshold effect level (Td), and the benchmark dose (BMD)), using data for the induction of micronuclei and gene mutations by methyl methanesulfonate or ethyl methanesulfonate in vitro and in vivo. These results suggest that the POD descriptors obtained using the different approaches are within the same order of magnitude, with more variability observed for the in vivo assays. The different approaches were found to be complementary as each has advantages and limitations. The results further indicate that the lower confidence limit of a benchmark response rate of 10% (BMDL(10) ) could be considered a satisfactory POD when analyzing genotoxicity data using the BMD approach. The models described permit the identification of POD values that could be combined with mode of action analysis to determine whether exposure(s) below a particular level constitutes a significant human risk. Subsequent analyses will expand the number of substances and endpoints investigated, and continue to evaluate the utility of quantitative approaches for analysis of genetic toxicity dose-response data.

Hepatic abscess complicating transarterial chemoembolization in a patient with liver metastases

Hepatic abscess following transarterial chemoembolization is an uncommon complication. The authors describe a case of liver abscess after transarterial chemoembolization for neuroendocrine liver metastases, including risk factors, prophylaxis, treatment, and outcomes.

Raised interleukin-17 is immunolocalised to neutrophils in cystic fibrosis lung disease

Interleukin (IL)-17 is pivotal in orchestrating the activity of neutrophils. Neutrophilic inflammation is the dominant pathology in cystic fibrosis (CF) lung disease. We investigated IL-17 protein expression in the lower airway in CF, its cellular immunolocalisation and the effects of IL-17 on CF primary bronchial epithelial cells. Immunohistochemistry was performed on explanted CF lungs and compared with the non-suppurative condition pulmonary hypertension (PH). Airway lavages and epithelial cultures were generated from explanted CF lungs. Immunoreactivity for IL-17 was significantly increased in the lower airway epithelium in CF (median 14.1%) compared with PH (2.95%, p=0.0001). The number of cells staining positive for IL-17 in the lower airway mucosa was also increased (64 cells·mm(-1) compared with 9 cells·mm(-1) basement membrane, p=0.0005) and included both neutrophils in addition to mononuclear cells. IL-17 was detectable in airway lavages from explanted CF lungs. Treatment of epithelial cultures with IL-17 increased production of IL-8, IL-6 and granulocyte macrophage colony-stimulating factor. In conclusion, immunoreactive IL-17 is raised in the lower airway of people with CF and localises to both neutrophils and mononuclear cells. IL-17 increases production of pro-neutrophilic mediators by CF epithelial cells, suggesting potential for a positive feedback element in airway inflammation.

Inflammation and epithelial to mesenchymal transition in lung transplant recipients: role in dysregulated epithelial wound repair

Epithelial to mesenchymal transition (EMT) has been implicated in the pathogenesis of obliterative bronchiolitis (OB) after lung transplant. Although TNF-alpha accentuates TGF-beta1 driven EMT in primary human bronchial epithelial cells (PBECs), we hypothesized that other acute pro-inflammatory cytokines elevated in the airways of patients with OB may also accentuate EMT and contribute to dysregulated epithelial wound repair. PBECs from lung transplant recipients were stimulated with TGF-beta1+/-IL-1beta, IL-8, TNF-alpha or activated macrophages in co-culture and EMT assessed. The quality and rate of wound closure in a standardized model of lung epithelial injury was assessed in response to above stimuli. Co-treatment with TGF-beta1+TNF-alpha or IL-1beta significantly accentuates phenotypic and some functional features of EMT compared to TGF-beta1 alone. Co-treatment with TGF-beta1+TNF-alpha or IL-1beta accelerates epithelial wound closure however the quality of repair is highly dysregulated. Co-treatment with TGF-beta1+IL-8 has no significant effect on EMT or the speed or quality of wound healing. Activated macrophages dramatically accentuate TGF-beta1-driven EMT and cause dysregulated wound repair. Crosstalk between macrophage-derived acute inflammation in the airway and elevated TGF-beta1 may favor dysregulated airway epithelial repair and fibrosis in the lung allograft via EMT.

Epithelial to mesenchymal transition (EMT) and airway remodelling after human lung transplantation

BACKGROUND

Aberrant epithelial repair is a key event in the airway remodelling which characterises obliterative bronchiolitis (OB) in the transplanted lung. The potential for airway epithelium from lung transplant recipients to undergo epithelial to mesenchymal cell transition (EMT) was assessed in culture and in vivo in lung allograft tissue.

METHODS

Change in epithelial and mesenchymal marker expression was assessed after stimulation with transforming growth factor beta(1) (TGF-beta(1)) alone or in combination with tumour necrosis factor alpha (TNFalpha) and compared with untreated controls. The ability of cells to deposit extracellular matrix, secrete matrix metalloproteinases (MMPs) and invade collagen was investigated. Immunolocalisation of epithelial and mesenchymal markers was compared in airway tissue from stable recipients and those with OB.

RESULTS

Untreated cells maintained epithelial morphology and phenotype. TGF-beta(1) reduced expression of epithelial markers, increased expression of vimentin and fibronectin, promoted collagen I and fibronectin deposition and increased MMP-9 production. Co-treatment with TNFalpha dramatically accentuated phenotypic and some functional features of EMT. Airway epithelial biopsies from recipients with OB demonstrated significantly increased staining for mesenchymal markers and significantly reduced E-cadherin staining compared with stable recipients.

CONCLUSIONS

These observations demonstrate the ability of human airway epithelium to undergo EMT and suggest this phenomenon may be a potential link between inflammatory injury and TGF-beta(1)-driven airway remodelling in the development of OB.

Radiation-induced transgenerational alterations in genome stability and DNA damage

Mutation induction in directly exposed cells is currently regarded as the main component of the genetic risk of ionizing radiation for humans. However, recent data on the transgenerational increases in mutation rates in the offspring of irradiated parents indicate that the genetic risk could be greater than predicted previously. Here, we have analysed transgenerational changes in mutation rates and DNA damage in the germline and somatic tissues of non-exposed first-generation offspring of irradiated inbred male CBA/Ca and BALB/c mice. Mutation rates at an expanded simple tandem repeat DNA locus and a protein-coding gene (hprt) were significantly elevated in both the germline (sperm) and somatic tissues of all the offspring of irradiated males. The transgenerational changes in mutation rates were attributed to the presence of a persistent subset of endogenous DNA lesions (double- and single-strand breaks), measured by the phosphorylated form of histone H2AX (gamma-H2AX) and alkaline Comet assays. Such remarkable transgenerational destabilization of the F(1) genome may have important implications for cancer aetiology and genetic risk estimates. Our data also provide important clues on the still unknown mechanisms of radiation-induced genomic instability.

Primary airway epithelial cell culture from lung transplant recipients

Long-term survival in lung transplantation is limited by the development of obliterative bronchiolitis, a condition characterised by inflammation, epithelial injury, fibroproliferation and obliteration of bronchioles leading to airflow obstruction. To investigate the role of the bronchial epithelium in the pathogenesis of obliterative bronchiolitis the current study aimed to establish primary bronchial epithelial cell cultures (PBEC) from lung allografts. Four to six bronchial brushings were obtained from sub-segmental bronchi of lung allografts. Cells were seeded onto collagen-coated plates and grown to confluence in bronchial epithelial growth medium. Bronchial brushings (n=33) were obtained from 27 patients. PBECs were grown to confluence from 12 out of 33 (39%) brushings. Failure to reach confluence was due to early innate infection. Bacteria were usually isolated from both bronchoalveolar lavage and culture media, but a separate population was identified in culture media only. Primary culture of bronchial epithelial cells from lung transplant recipients is feasible, despite a high rate of early, patient-derived infection. Latent infection of the allograft, identified only by bronchial brushings, may itself be a persistent stimulus for epithelial injury. This technique facilitates future mechanistic studies of airway epithelial responses in the pathogenesis of obliterative bronchiolitis.

Do dose response thresholds exist for genotoxic alkylating agents?

The demonstration and acceptance of dose response thresholds for genotoxins may have substantial implications for the setting of safe exposure levels. Here we test the hypothesis that direct-acting DNA reactive agents may exhibit thresholded dose responses. We examine the potential mechanisms involved in such thresholded responses, particularly in relation to those of alkylating agents. As alkylating agents are representative model DNA reactive compounds with well characterized activities and DNA targets, they could help shed light on the general mechanisms involved in thresholded dose responses for genotoxins. Presently, thresholds have mainly been described for agents with non-DNA targets. We pay particular attention here to the contribution of DNA repair to genotoxic thresholds. A review of the literature shows that limited threshold data for alkylating agents are currently available, but the contribution of DNA repair in thresholded dose responses is suggested by several studies. The existence of genotoxic thresholds for alkylating agents methylmethanesulfonate is also supported here by data from our laboratory. Overall, it is clear that different endpoints induced by the same alkylator, can possess different dose response characteristics. This may have an impact on the setting of safe exposure levels for such agents. The limited information available concerning the dose response relationships of alkylators can nevertheless lead to the design of experiments to investigate the mechanisms that may be involved in threshold responses. Through using paired alkylators inducing different lesions, repaired by different pathways, insights into the processes involved in genotoxic thresholds may be elucidated. Furthermore, as alkyl-guanine-DNA transferase, base excision repair and mismatch repair appear to contribute to genotoxic thresholds for alkylators, cells deficient in these repair processes may possess altered dose responses compared with wild-type cells and this approach may help understand the contribution of these repair pathways to the production of thresholds for genotoxic effects in general. Finally, genotoxic thresholds are currently being described for acute exposures to single agents in vitro, however, dose response data for chronic exposures to complex mixtures are, as yet, a long way off.

Pepsin like activity in bronchoalveolar lavage fluid is suggestive of gastric aspiration in lung allografts

BACKGROUND

A biologically plausible link between gastro-oesophageal reflux (GOR), aspiration, and lung allograft dysfunction has been suggested, but there is no systematic evidence indicating the presence of gastric contents in the lung. We have tested the hypothesis that pepsin, as a marker of aspiration, is detectable in bronchoalveolar lavage (BAL) fluid of allograft recipients who had not reported symptoms of GOR.

METHODS

Standardised 3 x 60 ml surveillance BAL fluid samples from 13 chronologically sequential stable lung allograft recipients without chronic rejection (10 patients treated with a prophylactic proton pump inhibitor) were studied. Lavage supernatants were assayed by an ELISA based on a monospecific goat antibody for pepsin/pepsinogen. Pepsin levels were compared with those from four normal volunteer controls.

RESULTS

Pepsin levels were measurable in all allograft recipients, in keeping with gastric aspiration (median 109 ng/ml (range 35-1375)). In the control group the pepsin levels were below the limit of detection. Treatment with a proton pump inhibitor was not correlated with pepsin levels. There was no correlation between BAL fluid neutrophils and pepsin levels.

CONCLUSION

These data demonstrate lung epithelial lining fluid concentrations of pepsin in lung allograft recipients which are much higher than blood reference levels, with no detectable pepsin in controls. This provides direct evidence of gastric aspiration, which is potentially injurious to the allograft.

Pepsin like activity in bronchoalveolar lavage fluid is suggestive of gastric aspiration in lung allografts

BACKGROUND

A biologically plausible link between gastro-oesophageal reflux (GOR), aspiration, and lung allograft dysfunction has been suggested, but there is no systematic evidence indicating the presence of gastric contents in the lung. We have tested the hypothesis that pepsin, as a marker of aspiration, is detectable in bronchoalveolar lavage (BAL) fluid of allograft recipients who had not reported symptoms of GOR.

METHODS

Standardised 3 x 60 ml surveillance BAL fluid samples from 13 chronologically sequential stable lung allograft recipients without chronic rejection (10 patients treated with a prophylactic proton pump inhibitor) were studied. Lavage supernatants were assayed by an ELISA based on a monospecific goat antibody for pepsin/pepsinogen. Pepsin levels were compared with those from four normal volunteer controls.

RESULTS

Pepsin levels were measurable in all allograft recipients, in keeping with gastric aspiration (median 109 ng/ml (range 35-1375)). In the control group the pepsin levels were below the limit of detection. Treatment with a proton pump inhibitor was not correlated with pepsin levels. There was no correlation between BAL fluid neutrophils and pepsin levels.

CONCLUSION

These data demonstrate lung epithelial lining fluid concentrations of pepsin in lung allograft recipients which are much higher than blood reference levels, with no detectable pepsin in controls. This provides direct evidence of gastric aspiration, which is potentially injurious to the allograft.

Phenotype of airway epithelial cells suggests epithelial to mesenchymal cell transition in clinically stable lung transplant recipients

BACKGROUND

Obliterative bronchiolitis in chronic rejection of lung allografts is characterised by airway epithelial damage and fibrosis. The process whereby normal epithelium is lost and replaced by fibroblastic scar tissue is poorly understood, but recent findings suggest that epithelial cells can become fibroblasts through epithelial-mesenchymal transition (EMT). It is hypothesised that EMT occurs in lung allografts and plays a potential role in airway remodelling.

METHODS

Sixteen stable lung transplant recipients underwent bronchoscopy with bronchoalveolar lavage (BAL), endobronchial biopsies, and bronchial brushings. Biopsy sections were stained for the fibroblast marker S100A4. Brushings were cultured on collagen, stained with anti-S100A4, and examined for further EMT markers including matrix metalloproteinase (MMP) zymographic activity and epithelial invasion through collagen coated filters.

RESULTS

A median 15% (0-48%) of the biopsy epithelium stained for S100A4 in stable lung transplant recipients and MMP-7 co-localisation was observed. In non-stimulated epithelial cultures from lung allografts, S100A4 staining was identified with MMP-2 and MMP-9 production and zymographic activity. MMP total protein and activity was increased following stimulation with transforming growth factor (TGF)-beta1. Non-stimulated transplant epithelial cells were invasive and penetration of collagen coated filters increased following TGF-beta1 stimulation.

CONCLUSIONS

This study provides evidence of EMT markers in lung allografts of patients without loss of lung function. The EMT process may represent a final common pathway following injury in more common diseases characterised by airway remodelling.

Passive ranging through wave-front coding: information and application

Passive-ranging systems based on wave-front coding are introduced. These single-aperture hybrid optical-digital systems are analyzed by use of linear models and the Fisher information matrix. Two schemes for passive ranging by use of a single aperture and a single image are investigated: (i) estimating the range to an object and (ii) detecting objects over a set of ranges. Theoretical limitations on estimator-error variances are given by use of the Cramer-Rao bounds. Evaluations show that range estimates with less than 0.1% error can be obtained from a single wave-front coded image. An experimental system was also built, and example results are given.

Cloning of a phosphatidic acid-preferring phospholipase A1 from bovine testis

We report the molecular cloning and expression of a phosphatidic acid-preferring phospholipase A1 from bovine testis. The open reading frame encoded an 875-amino acid protein with a calculated molecular mass of 97,576 daltons and a pI of 5.61. The sequence included a region similar to a lipase consensus sequence containing the putative active site serine and also included a potential, coiled-coil-forming region. Expression of the open reading frame in COS1 cells resulted in a 20-44-fold increase in phosphatidic acid phospholipase A1 activity over that of control cells. Mutation of the putative active site serine (amino acid 540) demonstrated that it was essential for this increase in enzyme activity. Northern blot analysis revealed at least five different messages with the highest overall message levels in mature testis, but detectable message in all tissues examined. Two possible alternately spliced regions in the open reading frame also were identified. Finally, a search of the data base identified six related proteins: a potential counterpart of the phospholipase A1 in Caenorhabditis elegans, two putative lipases in yeast, and three proteins separately encoded by the Drosophila retinal degeneration B gene and its mouse and human homologues.

Adolescent idiopathic scoliosis. Long-term effect of instrumentation extending to the lumbar spine

We evaluated eighty-three patients in whom adolescent idiopathic scoliosis had been treated with a posterior spinal arthrodesis and Harrington instrumentation extending to the second, third, fourth, or fifth lumbar vertebra. All eighty-three patients completed a questionnaire, and fifty-five patients were also examined clinically and roentgenographically at a follow-up evaluation at an average of twelve years (range, ten to sixteen years). Twelve patients had a type-I curve; twenty-six, a type-II curve; sixteen, a type-III curve; and one, a type-IV curve, according to the classification of King et al. The preoperative Cobb angle of the primary curve averaged 60 degrees and ranged from 40 to 100 degrees. The curve was an average of 35 degrees (range, 15 to 65 degrees) at the most recent follow-up evaluation. Functional assessment with use of information from the questionnaire revealed an average spine score of 81 points (range, 18 to 99 points). On the basis of the score, thirty-five patients were considered to have had an excellent result; twenty, a good result; thirteen, a fair result; and fifteen, a poor result. Sixty-three (76 per cent) of the eighty-three patients had low-back pain compared with thirty (50 per cent) of sixty individuals who served as a control group. This difference was significant (p < 0.001; chi-square test). Eighteen patients (22 per cent) needed additional spinal procedures. Fourteen patients (17 per cent) did not think that the goals of the initial operation had been accomplished.(ABSTRACT TRUNCATED AT 250 WORDS)

Outpatient surgical management of arthrofibrosis after anterior cruciate ligament surgery

We present a consecutive series of nine patients who were referred to us because of arthrofibrosis (loss of > 15 degrees of extension) after intraarticular anterior cruciate ligament reconstruction using autogenous patellar tendon (eight patients) or semitendinosus (one patient) graft. Eight patients had surgery within 2 weeks of injury. All patients had been immobilized in flexion after the anterior cruciate ligament reconstruction and they had failed to improve despite vigorous physical therapy and other closed methods of treatment. The mean time from anterior cruciate ligament reconstruction to the subsequent surgery was 10.2 months (range, 3 to 14). The patients underwent an outpatient arthroscopic anterior scar resection, notchplasty, a closed knee manipulation for flexion, and extension casting. Serial daily extension cast changes allowed the patients to obtain full extension, which was maintained by a bivalved extension splint for bedtime use. Flexion was actively sought by aggressive outpatient physical therapy. All patients except one noted near-normal ultimate range of motion. One patient could only attain 10 degrees short of flat extension at the end of his rehabilitation and was considered a failed result. At final followup (mean, 31 months), no patient complained of symptoms of instability, all had a normal gait, and all but one were able to return to athletic activities.

Locked bucket-handle meniscal tears in knees with chronic anterior cruciate ligament deficiency

Because we noticed patients had difficulty regaining full range of motion after surgery for a locked bucket-handle meniscal tear with simultaneous reconstruction for a chronic anterior cruciate ligament tear, we adopted a two-stage procedure for this group of patients. We evaluated the results of a two-stage procedure in the knees of 16 athletes (Group 1) and compared their outcome with the outcome of 16 matched athletes who had been treated with simultaneous repair or removal of the displaced bucket-handle meniscal tear and autogenous patellar tendon anterior cruciate ligament reconstruction (Group 2). Four patients in Group 2 required a second procedure or casting to regain full extension. No patient in Group 1 required a second procedure. One meniscal retear was detected in Group 1. The two-stage procedure also appears to have a number of theoretical advantages: 1) more aggressive use of repair rather than removal of a displaced torn meniscus, 2) prevention of problems in regaining range of motion, 3) allows a second look to judge the success of meniscal repair, and 4) allows time for the patient to prepare for anterior cruciate ligament reconstruction physically, mentally, academically, and socially.