Juan Caicedo - Academia.edu (original) (raw)

Papers by Juan Caicedo

Research paper thumbnail of Comparing Real World, Personalized, Multidisciplinary Tumor Board Recommendations with BCLC Algorithm: 321-Patient Analysis

CardioVascular and Interventional Radiology, 2021

To evaluate hepatocellular carcinoma (HCC) treatment allocation, deviation from BCLC first-treatm... more To evaluate hepatocellular carcinoma (HCC) treatment allocation, deviation from BCLC first-treatment recommendation, and outcomes following multidisciplinary, individualized approach. Treatment-naïve HCC discussed at multidisciplinary tumor board (MDT) between 2010 and 2013 were included to allow minimum 5 years of follow-up. MDT first-treatment recommendation (resection, transplant, ablation, transarterial radioembolization (Y90), transarterial chemoembolization, sorafenib, palliation) was documented, as were subsequent treatments. Overall survival (OS) analyses were performed on an intention-to-treat (ITT) basis, stratified by BCLC stage. Three hundred and twenty-one patients were treated in the 4-year period. Median age was 62 years, predominantly male (73%), hepatitis C (41%), and Y90 initial treatment (52%). There was a 76% rate of BCLC-discordant first-treatment. Median OS was not reached (57% alive at 10 years), 51.0 months, 25.4 months and 13.4 months for BCLC stages A, B, C and D, respectively. Deviation from BCLC guidelines was very common when individualized, MDT treatment recommendations were made. This approach yielded expected OS in BCLC A, and exceeded general guideline expectations for BCLC B, C and D. These results suggest that while guidelines are helpful, implementing a more personalized approach that incorporates center expertise, patient-specific characteristics, and the known multi-directional treatment allocation process, improves patient outcomes.

Research paper thumbnail of Radiation Segmentectomy: Potential Curative Therapy for Early Hepatocellular Carcinoma

Radiology, Jan 24, 2018

Purpose To report long-term outcomes of radiation segmentectomy (RS) for early hepatocellular car... more Purpose To report long-term outcomes of radiation segmentectomy (RS) for early hepatocellular carcinoma (HCC). The authors hypothesized that outcomes are comparable to curative treatments for patients with solitary HCC less than or equal to 5 cm and preserved liver function. Materials and Methods This retrospective study included 70 patients (median age, 71 years; range, 22-96 years) with solitary HCC less than or equal to 5 cm not amenable to percutaneous ablation who underwent RS (dose of >190 Gy) between 2003 and 2016. Patients who underwent subsequent curative liver transplantation were excluded to eliminate this confounding variable affecting survival. Radiologic response of time to progression and median overall survival were estimated by using the Kaplan-Meier method per the guidelines of the European Association for the Study of the Liver (EASL) and the World Health Organization (WHO). Results Seventy patients were treated with RS over 14 years. Sixty-three patients (90%)...

Research paper thumbnail of Institutional Decision to Adopt Y90 as Primary Treatment for HCC Informed by a 1,000-patient 15-year Experience

Hepatology (Baltimore, Md.), 2017

Y90 transarterial radioembolization (TARE) is a transarterial locoregional therapy (LRT) for hepa... more Y90 transarterial radioembolization (TARE) is a transarterial locoregional therapy (LRT) for hepatocellular carcinoma (HCC). In this study, we present overall survival outcomes (OS) in a 1000-patient cohort acquired over a 15-year period. Between December 1, 2003 and March 31, 2017, 1000 patients with HCC were treated with TARE as part of a prospective cohort study. A comprehensive review of toxicity and survival outcomes was performed. Outcomes were stratified by baseline Child-Pugh (CP) class, United Network for Organ Sharing (UNOS) and Barcelona Clinic Liver Cancer (BCLC) staging systems. Albumin and bilirubin laboratory toxicities were compared to baseline. OS outcomes were reported using censoring and intention-to-treat methodologies. All treatments were outpatient, with a median 1 treatment per patient. 506 (51%) were CP A, 450 (45%) CP B, and 44 (4%) CP C. 263 (26%) patients were BCLC A, 152 (15%) B, 541 (54%) C, and 44 (4%) D. 368 (37%) were UNOS T1/T2, 169 (17%) T3, 147 (15...

Research paper thumbnail of Pretransplantation Portal Vein Recanalization and Transjugular Intrahepatic Portosystemic Shunt Creation for Chronic Portal Vein Thrombosis: Final Analysis of a 61-Patient Cohort

Journal of vascular and interventional radiology : JVIR, Jan 17, 2017

To report the final analysis of the safety and efficacy of portal vein (PV) recanalization (PVR) ... more To report the final analysis of the safety and efficacy of portal vein (PV) recanalization (PVR) and transjugular intrahepatic portosystemic shunt (TIPS) creation (PVR-TIPS) in patients with PV thrombosis (PVT) in need of liver transplantation. Sixty-one patients with cirrhosis and PVT underwent PVR-TIPS to improve transplantation candidacy. Median patient age was 58 years (range, 22-75 y), and median pre-TIPS Model for End-Stage Liver Disease score was 14 (range, 7-42). The most common etiologies of cirrhosis were nonalcoholic fatty liver disease in 18 patients (30%) and hepatitis C in 13 patients (21%). Twenty-seven patients (44%) had partial PVT, and 34 patients (56%) had complete thrombosis. Forty-nine patients (80%) had Yerdel grade 2 PVT, and 12 (20%) had Yerdel grade 3 PVT. Twenty-nine patients (48%) had cavernous transformation of the PV. PVR-TIPS was technically successful in 60 of 61 patients (98%). PV/TIPS patency was maintained in 55 patients (92%) at a median follow-up ...

Research paper thumbnail of Clinical outcomes of Y90 radioembolization for recurrent hepatocellular carcinoma following curative resection

European journal of nuclear medicine and molecular imaging, Jan 15, 2017

To assess safety/efficacy of yttrium-90 radioembolization (Y90) in patients with recurrent hepato... more To assess safety/efficacy of yttrium-90 radioembolization (Y90) in patients with recurrent hepatocellular carcinoma (HCC) following curative surgical resection. With IRB approval, we searched our prospectively acquired database for patients that were treated with Y90 for recurrent disease following resection. Baseline characteristics and bilirubin toxicities following Y90 were evaluated. Intention-to-treat overall survival (OS) and time-to-progression (TTP) from Y90 were assessed. Forty-one patients met study inclusion criteria. Twenty-six (63%) patients had undergone minor (≤3 hepatic segments) resection while 15 (37%) patients underwent major (>3 hepatic segments) resections. Two patients (5%) had biliary-enteric anastomoses created during surgical resection. The median time from HCC resection to the first radioembolization was 17 months (95% CI: 13-37). The median number of Y90 treatment sessions was 1 (range: 1-5). Ten patients received (entire remnant) lobar Y90 treatment wh...

Research paper thumbnail of 90Y radiation lobectomy: Outcomes following surgical resection in patients with hepatic tumors and small future liver remnant volumes

Journal of Surgical Oncology, 2016

Research paper thumbnail of Hispanic/Latino Disparities in Living Donor Kidney Transplantation

Transplantation Direct, 2015

Background. Hispanic Americans face disparities in access to kidney transplantation, particularly... more Background. Hispanic Americans face disparities in access to kidney transplantation, particularly living donor kidney transplantation (LDKT). This study compared characteristics of LDKT recipients before and after implementing the Hispanic Kidney Transplant Program (HKTP) at Northwestern Medicines (NM) and other centers. Methods. The NM HKTP, initiated in December 2006, delivers culturally and linguistically competent and congruent care. Program-specific data were used to compare the mean ratios of Hispanic to non-Hispanic white LDKTs between pre-HKTP (2001-2006) and post-HKTP (2008-2013), and to compare the characteristics of NM's adult LDKT patients between pre-HKTP and post-HKTP. The same ratio was calculated for transplant centers in regions with a significant Hispanic population (≥25%) and performing in the top tertile of total LDKT volume in the pre-HKTP period. The number of Hispanic and non-Hispanic white patients added to the waiting list were compared between pre-HKTP (2001-2006) and post-HKTP (2008-2013) as a proxy for increased patient referrals and a pathway by which the HKTP may increase LDKTs. Results. The ratio of Hispanic to non-Hispanic white LDKTs significantly increased by 70% after the implementation of NM's HKTP (pre-HKTP mean = 0.20, post-HKTP mean = 0.34; P= 0.001). None of the other transplant centers experienced a similar increase in their ratio of Hispanic to non-Hispanic white LDKTs. The NM waiting list additions grew by 91% among Hispanics, but grew only 4% for non-Hispanic whites. Conclusions. These data suggest that the development and implementation of a culturally congruent transplant program can positively affect Hispanic LDKTand thereby reduce Hispanics disparities in LDKTrates. Further studies are needed to prospectively evaluate the generalizability of implementing such culturally competent interventions at other transplant programs.

Research paper thumbnail of Comparative study of post-transplant outcomes in hepatocellular carcinoma patients bridged or downstaged by transarterial chemoembolization or 90Y radioembolization

Journal of Vascular and Interventional Radiology, 2015

Purpose: To analyze long-term outcomes in patients bridged/downstaged to orthotopic liver transpl... more Purpose: To analyze long-term outcomes in patients bridged/downstaged to orthotopic liver transplantation (OLT) by transarterial chemoembolization (TACE) or yttrium-90 radioembolization (Y90) for hepatocellular carcinoma (HCC). Methods: 172 HCC patients who underwent OLT after being treated with transarterial liver-directed therapies (LDTs) (Y90:93; TACE:79) were identified. Pre-LDT and pre-OLT clinical/imaging/laboratory characteristics including United Network for Organ Sharing (UNOS) staging and alpha-fetoprotein values (AFP) were tabulated. Post-OLT HCC recurrence was assessed by imaging follow-up per standard of care. Recurrencefree (RFS) and overall survival (OS) were calculated. Uni/multivariate and substratification analyses were performed. Results: Time-to-OLT was longer in the Y90 group (Y90:6.5 months; TACE:4.8 months; p=0.02). With a median post-OLT follow-up of 26.

Research paper thumbnail of Expanded infectious diseases screening program for Hispanic transplant candidates

Transplant Infectious Disease, 2010

Most guidelines for pre-transplant screening recommend enhanced screening among patients with pot... more Most guidelines for pre-transplant screening recommend enhanced screening among patients with potential exposure to such pathogens as Strongyloides stercoralis andTrypanosoma cruzi, the cause of Chagas disease. The incidence of these diseases in the Hispanic immigrant population has not been extensively studied. Transplant candidates who were evaluated by our program's Hispanic Transplant Program were referred for expanded infectious disease screening including Mycobacterium tuberculosis, S. stercoralis, Leishmania, and T. cruzi. Between December 2006 and December 2008, 83 patients were screened. Most were from Mexico but we also screened patients from Ecuador, Puerto Rico, and Peru. Most patients lived in urban locations before moving to the United States. Latent tuberculosis infection (LTBI) was found in 20%, and 6.7% had serologic evidence of S. stercoralis infection. These patients underwent treatment of latent infection without di⁄culty. To date, 14 patients have undergone living-donor kidney transplantation. Two of these patients had positive Leishmania titers and are being followed clinically, 1 was treated for S. stercoralis, and 2 were treated for LTBI pre-transplant. All have done well without evidence of screened pathogens an average of 348 days (range 65^766 days) post transplant. Expanded screening identi¢es endemic infections in the Hispanic immigrant population that can be treated before transplant, thereby minimizing post-transplant infectious complications.

Research paper thumbnail of Ethnic advantages in kidney transplant outcomes: the Hispanic Paradox at work?

Nephrology Dialysis Transplantation, 2008

1-year survival rates surpassing 91%, long-term graft survival remains inadequate [1]. The 3-year... more 1-year survival rates surpassing 91%, long-term graft survival remains inadequate [1]. The 3-year, 5-year and 10-year deceased donor unadjusted graft survival rates are 78.6%, 67.1% and 40.8%, respectively, among all kidney recipients in the United States (USA) [2]. The loss of transplanted grafts is a major public health problem. Kidney transplantation is the treatment of choice for most patients with end-stage renal disease (ESRD) since it provides a longer length of life, better quality of life [3,4] and is more cost-effective than dialysis [5,6]. When kidney grafts fail, patients return to dialysis, creating an even greater demand for scarce kidney (re-)transplants and further burdening society with greater costs [7-9]. Mortality rates on dialysis following a failed kidney transplant are

Research paper thumbnail of Unresectable solitary hepatocellular carcinoma not amenable to radiofrequency ablation: Multicenter radiology-pathology correlation and survival of radiation segmentectomy

Hepatology, 2014

Resection and radiofrequency ablation (RFA) are treatment options for hepatocellular carcinoma (H... more Resection and radiofrequency ablation (RFA) are treatment options for hepatocellular carcinoma (HCC) <3 cm; there is interest in expanding the role of ablation to 3-5 cm. RFA is considered high-risk when the lesion is in close proximity to critical structures. Combining microcatheter technology and the localized emission properties of Y90, highly selective radioembolization is a possible alternative to RFA in such cases. We assessed the efficacy (response, radiology-pathology correlation, survival) of radiation segmentectomy in solitary HCC not amenable to RFA or resection. Patients with treatment-naïve, unresectable, solitary HCC ≤ 5 cm not amenable to RFA were included in this multicenter study. Administered dose, response rate, time-to-progression (modified Response Evaluation Criteria in Solid Tumors [mRECIST]), radiology-pathology correlation and long-term survival were assessed. In all, 102 patients were included in this study. mRECIST complete response (CR), partial response (PR), and stable disease (SD) were 47/99 (47%), 39/99 (39%), and 12/99 (12%), respectively. Median time-to-disease-progression was 33.1 months. In all, 33/102 (32%) patients were transplanted with a median (interquartile range [IQR]) time-to-transplantation of 6.3 months (3.6-9.7). Pathology revealed 100% and 50-99% necrosis in 17/33 (52%) and 16/33 (48%), respectively. Median overall survival was 53.4 months. Univariate analysis demonstrated a survival benefit for Eastern Cooperative Oncology Group (ECOG) 0 patients. In the multivariate model, age <65, ECOG 0, and Child-Pugh A were…

Research paper thumbnail of NUTORC—a transdisciplinary health services and outcomes research team in transplantation

Translational Behavioral Medicine, 2012

The field of solid organ transplantation has historically concentrated research efforts on basic ... more The field of solid organ transplantation has historically concentrated research efforts on basic science and translational studies. However, there has been increasing interest in health services and outcomes research. The aim was to build an effective and sustainable, inter-and transdisciplinary health services and outcomes research team (NUTORC), that leveraged institutional strengths in social science, engineering, and management disciplines, coupled with an international recognized transplant program. In 2008, leading methodological experts across the university were identified and intramural funding was obtained for the NUTORC initiative. Inter-and transdisciplinary collaborative teams were created across departments and schools within the university. Within 3 years, NUTORC became fiscally sustainable, yielding more than tenfold return of the initial investment. Academic productivity included funding for 39 grants, publication of 60 manuscripts, and 166 national presentations. Sustainable educational opportunities for students were created. Inter-and transdisciplinary health services and outcomes research in transplant can be innovative and sustainable.

Research paper thumbnail of Long Term Outcomes of Hispanic Liver Transplant Recipients - The Hispanic Paradox

American Journal of Transplantation

Research paper thumbnail of Long-Term Outcomes of Pediatric Kidney Transplantation in Hispanics

American Journal of Transplantation

Research paper thumbnail of Investigating the role of feedstock properties and process conditions on products formed during the hydrothermal carbonization of organics using regression techniques

Bioresource Technology, 2015

The purpose of this study is to develop regression models that describe the role of process condi... more The purpose of this study is to develop regression models that describe the role of process conditions and feedstock chemical properties on carbonization product characteristics. Experimental data were collected and compiled from literature-reported carbonization studies and subsequently analyzed using two statistical approaches: multiple linear regression and regression trees. Results from these analyses indicate that both the multiple linear regression and regression tree models fit the product characteristics data well. The regression tree models provide valuable insight into parameter relationships. Relative weight analyses indicate that process conditions are more influential to the solid yields and liquid and gas-phase carbon contents, while feedstock properties are more influential on the hydrochar carbon content, energy content, and the normalized carbon content of the solid.

Research paper thumbnail of Use of Wireless Smart Sensors for Detecting Human Falls through Structural Vibrations

Conference Proceedings of the Society for Experimental Mechanics Series, 2011

Falls are the leading cause of accidental deaths for people over the age of 65 because of the fal... more Falls are the leading cause of accidental deaths for people over the age of 65 because of the fall, fall related injury itself or related complications including hypothermia, dehydration, pressure sores and pneumonia. Several fall detection systems are commercially available including Life Alert, Life Link, and Alert One where the person wears a pendant that can be pressed in the case of an emergency or with newer models activates automatically when there is no motion. Pendant-based emergency systems become ineffective if the person is not wearing the pendant (refuses or forgets) or cannot press the pendant's button, for example when falling in a prone position on top of the device. In addition, the elderly are hesitant to use emergency systems for several reasons such as the concern of bothering others and personal pride. This paper proposes the use of structural vibrations to determine if a person has fallen. An Imote2 and an ITS400CA sensor board are used for the collection of structural vibrations induced by human activity, including falls. These sensors are discrete, and have shown potential for the data collection and diagnostic processing needed to detect human falls. The use of wireless smart sensors in the structure provides a non-intrusive method for human fall detection that does not require the use of any device by the person. A preliminary study of the classification of human induced vibration in a typical structure using traditional wired sensors is also discussed as well as a sensing framework used to study structural vibrations induced by human falls.

Research paper thumbnail of Bayesian Finite Element Model Updating Using Static and Dynamic Data

Conference Proceedings of the Society for Experimental Mechanics Series, 2011

Finite element models of current structures often behave differently than the structure itself. M... more Finite element models of current structures often behave differently than the structure itself. Model updating techniques are used to enhance the capabilities of the numerical model such that it behaves like the real structure. Experimental data is used in model updating techniques to identify the parameters of the numerical model. In civil infrastructure these model updating techniques use either static or dynamic measurements, separately. This paper studies how a Bayesian updating framework behaves when both static and ...

Research paper thumbnail of Content-based medical image retrieval using Low-Level visual features and modality identification

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2008

This paper presents the image retrieval results obtained by the BioIngenium Research Group, in th... more This paper presents the image retrieval results obtained by the BioIngenium Research Group, in the frame of the ImageCLEFmed 2007 edition. The applied approach consists of two main phases: a preprocessing phase, which builds an image category index and a retrieval phase, which ranks similar images. Both phases are based only on visual information. The experiments show a consistent frame with theory in content-based image retrieval: filtering images with a conceptual index outperforms only-ranking-based strategies; combining features is better than using individual features; and low-level features are not enough to model image semantics.

Research paper thumbnail of Quantification of fatigue cracking in CT specimens with passive and active piezoelectric sensing

Monitoring of fatigue cracks in steel bridges is of interest to bridge owners and agencies. Monit... more Monitoring of fatigue cracks in steel bridges is of interest to bridge owners and agencies. Monitoring of fatigue cracks has been attempted with acoustic emission using either resonant or broadband sensors. One drawback of passive sensing is that the data is limited to that caused by growing cracks. In this work, passive emission was complemented with active sensing (piezoelectric wafer active sensors) for enhanced detection capabilities. Passive and active sensing methods were described for fatigue crack monitoring on specialized compact tension specimens. The characteristics of acoustic emission were obtained to understand the correlation of acoustic emission behavior and crack growth. Crack and noise induced signals were interpreted through Swansong II Filter and waveform-based approaches, which are appropriate for data interpretation of field tests. Upon detection of crack extension, active sensing was activated to measure the crack size. Model updating techniques were employed to minimize the difference between the numerical results and experimental data. The long term objective of this research is to develop an in-service prognostic system to monitor structural health and to assess the remaining fatigue life.

Research paper thumbnail of Model updating and prognosis of acoustic emission data in compact test specimens under cyclic loading

abstract Acoustic emission (AE) is generated when cracks develop and it is used as an indicator o... more abstract Acoustic emission (AE) is generated when cracks develop and it is used as an indicator of the current state of damage in structural elements. Algorithms that use AE data to predict the state of a structural element are still in their research stages because the relationship between crack length and AE activity is not well understood. The process of trying to predict the future stage of a crack based on AE data is usually performed by an expert, and requires significant experience. This paper proposes a new strategy for the ...

Research paper thumbnail of Comparing Real World, Personalized, Multidisciplinary Tumor Board Recommendations with BCLC Algorithm: 321-Patient Analysis

CardioVascular and Interventional Radiology, 2021

To evaluate hepatocellular carcinoma (HCC) treatment allocation, deviation from BCLC first-treatm... more To evaluate hepatocellular carcinoma (HCC) treatment allocation, deviation from BCLC first-treatment recommendation, and outcomes following multidisciplinary, individualized approach. Treatment-naïve HCC discussed at multidisciplinary tumor board (MDT) between 2010 and 2013 were included to allow minimum 5 years of follow-up. MDT first-treatment recommendation (resection, transplant, ablation, transarterial radioembolization (Y90), transarterial chemoembolization, sorafenib, palliation) was documented, as were subsequent treatments. Overall survival (OS) analyses were performed on an intention-to-treat (ITT) basis, stratified by BCLC stage. Three hundred and twenty-one patients were treated in the 4-year period. Median age was 62 years, predominantly male (73%), hepatitis C (41%), and Y90 initial treatment (52%). There was a 76% rate of BCLC-discordant first-treatment. Median OS was not reached (57% alive at 10 years), 51.0 months, 25.4 months and 13.4 months for BCLC stages A, B, C and D, respectively. Deviation from BCLC guidelines was very common when individualized, MDT treatment recommendations were made. This approach yielded expected OS in BCLC A, and exceeded general guideline expectations for BCLC B, C and D. These results suggest that while guidelines are helpful, implementing a more personalized approach that incorporates center expertise, patient-specific characteristics, and the known multi-directional treatment allocation process, improves patient outcomes.

Research paper thumbnail of Radiation Segmentectomy: Potential Curative Therapy for Early Hepatocellular Carcinoma

Radiology, Jan 24, 2018

Purpose To report long-term outcomes of radiation segmentectomy (RS) for early hepatocellular car... more Purpose To report long-term outcomes of radiation segmentectomy (RS) for early hepatocellular carcinoma (HCC). The authors hypothesized that outcomes are comparable to curative treatments for patients with solitary HCC less than or equal to 5 cm and preserved liver function. Materials and Methods This retrospective study included 70 patients (median age, 71 years; range, 22-96 years) with solitary HCC less than or equal to 5 cm not amenable to percutaneous ablation who underwent RS (dose of >190 Gy) between 2003 and 2016. Patients who underwent subsequent curative liver transplantation were excluded to eliminate this confounding variable affecting survival. Radiologic response of time to progression and median overall survival were estimated by using the Kaplan-Meier method per the guidelines of the European Association for the Study of the Liver (EASL) and the World Health Organization (WHO). Results Seventy patients were treated with RS over 14 years. Sixty-three patients (90%)...

Research paper thumbnail of Institutional Decision to Adopt Y90 as Primary Treatment for HCC Informed by a 1,000-patient 15-year Experience

Hepatology (Baltimore, Md.), 2017

Y90 transarterial radioembolization (TARE) is a transarterial locoregional therapy (LRT) for hepa... more Y90 transarterial radioembolization (TARE) is a transarterial locoregional therapy (LRT) for hepatocellular carcinoma (HCC). In this study, we present overall survival outcomes (OS) in a 1000-patient cohort acquired over a 15-year period. Between December 1, 2003 and March 31, 2017, 1000 patients with HCC were treated with TARE as part of a prospective cohort study. A comprehensive review of toxicity and survival outcomes was performed. Outcomes were stratified by baseline Child-Pugh (CP) class, United Network for Organ Sharing (UNOS) and Barcelona Clinic Liver Cancer (BCLC) staging systems. Albumin and bilirubin laboratory toxicities were compared to baseline. OS outcomes were reported using censoring and intention-to-treat methodologies. All treatments were outpatient, with a median 1 treatment per patient. 506 (51%) were CP A, 450 (45%) CP B, and 44 (4%) CP C. 263 (26%) patients were BCLC A, 152 (15%) B, 541 (54%) C, and 44 (4%) D. 368 (37%) were UNOS T1/T2, 169 (17%) T3, 147 (15...

Research paper thumbnail of Pretransplantation Portal Vein Recanalization and Transjugular Intrahepatic Portosystemic Shunt Creation for Chronic Portal Vein Thrombosis: Final Analysis of a 61-Patient Cohort

Journal of vascular and interventional radiology : JVIR, Jan 17, 2017

To report the final analysis of the safety and efficacy of portal vein (PV) recanalization (PVR) ... more To report the final analysis of the safety and efficacy of portal vein (PV) recanalization (PVR) and transjugular intrahepatic portosystemic shunt (TIPS) creation (PVR-TIPS) in patients with PV thrombosis (PVT) in need of liver transplantation. Sixty-one patients with cirrhosis and PVT underwent PVR-TIPS to improve transplantation candidacy. Median patient age was 58 years (range, 22-75 y), and median pre-TIPS Model for End-Stage Liver Disease score was 14 (range, 7-42). The most common etiologies of cirrhosis were nonalcoholic fatty liver disease in 18 patients (30%) and hepatitis C in 13 patients (21%). Twenty-seven patients (44%) had partial PVT, and 34 patients (56%) had complete thrombosis. Forty-nine patients (80%) had Yerdel grade 2 PVT, and 12 (20%) had Yerdel grade 3 PVT. Twenty-nine patients (48%) had cavernous transformation of the PV. PVR-TIPS was technically successful in 60 of 61 patients (98%). PV/TIPS patency was maintained in 55 patients (92%) at a median follow-up ...

Research paper thumbnail of Clinical outcomes of Y90 radioembolization for recurrent hepatocellular carcinoma following curative resection

European journal of nuclear medicine and molecular imaging, Jan 15, 2017

To assess safety/efficacy of yttrium-90 radioembolization (Y90) in patients with recurrent hepato... more To assess safety/efficacy of yttrium-90 radioembolization (Y90) in patients with recurrent hepatocellular carcinoma (HCC) following curative surgical resection. With IRB approval, we searched our prospectively acquired database for patients that were treated with Y90 for recurrent disease following resection. Baseline characteristics and bilirubin toxicities following Y90 were evaluated. Intention-to-treat overall survival (OS) and time-to-progression (TTP) from Y90 were assessed. Forty-one patients met study inclusion criteria. Twenty-six (63%) patients had undergone minor (≤3 hepatic segments) resection while 15 (37%) patients underwent major (>3 hepatic segments) resections. Two patients (5%) had biliary-enteric anastomoses created during surgical resection. The median time from HCC resection to the first radioembolization was 17 months (95% CI: 13-37). The median number of Y90 treatment sessions was 1 (range: 1-5). Ten patients received (entire remnant) lobar Y90 treatment wh...

Research paper thumbnail of 90Y radiation lobectomy: Outcomes following surgical resection in patients with hepatic tumors and small future liver remnant volumes

Journal of Surgical Oncology, 2016

Research paper thumbnail of Hispanic/Latino Disparities in Living Donor Kidney Transplantation

Transplantation Direct, 2015

Background. Hispanic Americans face disparities in access to kidney transplantation, particularly... more Background. Hispanic Americans face disparities in access to kidney transplantation, particularly living donor kidney transplantation (LDKT). This study compared characteristics of LDKT recipients before and after implementing the Hispanic Kidney Transplant Program (HKTP) at Northwestern Medicines (NM) and other centers. Methods. The NM HKTP, initiated in December 2006, delivers culturally and linguistically competent and congruent care. Program-specific data were used to compare the mean ratios of Hispanic to non-Hispanic white LDKTs between pre-HKTP (2001-2006) and post-HKTP (2008-2013), and to compare the characteristics of NM's adult LDKT patients between pre-HKTP and post-HKTP. The same ratio was calculated for transplant centers in regions with a significant Hispanic population (≥25%) and performing in the top tertile of total LDKT volume in the pre-HKTP period. The number of Hispanic and non-Hispanic white patients added to the waiting list were compared between pre-HKTP (2001-2006) and post-HKTP (2008-2013) as a proxy for increased patient referrals and a pathway by which the HKTP may increase LDKTs. Results. The ratio of Hispanic to non-Hispanic white LDKTs significantly increased by 70% after the implementation of NM's HKTP (pre-HKTP mean = 0.20, post-HKTP mean = 0.34; P= 0.001). None of the other transplant centers experienced a similar increase in their ratio of Hispanic to non-Hispanic white LDKTs. The NM waiting list additions grew by 91% among Hispanics, but grew only 4% for non-Hispanic whites. Conclusions. These data suggest that the development and implementation of a culturally congruent transplant program can positively affect Hispanic LDKTand thereby reduce Hispanics disparities in LDKTrates. Further studies are needed to prospectively evaluate the generalizability of implementing such culturally competent interventions at other transplant programs.

Research paper thumbnail of Comparative study of post-transplant outcomes in hepatocellular carcinoma patients bridged or downstaged by transarterial chemoembolization or 90Y radioembolization

Journal of Vascular and Interventional Radiology, 2015

Purpose: To analyze long-term outcomes in patients bridged/downstaged to orthotopic liver transpl... more Purpose: To analyze long-term outcomes in patients bridged/downstaged to orthotopic liver transplantation (OLT) by transarterial chemoembolization (TACE) or yttrium-90 radioembolization (Y90) for hepatocellular carcinoma (HCC). Methods: 172 HCC patients who underwent OLT after being treated with transarterial liver-directed therapies (LDTs) (Y90:93; TACE:79) were identified. Pre-LDT and pre-OLT clinical/imaging/laboratory characteristics including United Network for Organ Sharing (UNOS) staging and alpha-fetoprotein values (AFP) were tabulated. Post-OLT HCC recurrence was assessed by imaging follow-up per standard of care. Recurrencefree (RFS) and overall survival (OS) were calculated. Uni/multivariate and substratification analyses were performed. Results: Time-to-OLT was longer in the Y90 group (Y90:6.5 months; TACE:4.8 months; p=0.02). With a median post-OLT follow-up of 26.

Research paper thumbnail of Expanded infectious diseases screening program for Hispanic transplant candidates

Transplant Infectious Disease, 2010

Most guidelines for pre-transplant screening recommend enhanced screening among patients with pot... more Most guidelines for pre-transplant screening recommend enhanced screening among patients with potential exposure to such pathogens as Strongyloides stercoralis andTrypanosoma cruzi, the cause of Chagas disease. The incidence of these diseases in the Hispanic immigrant population has not been extensively studied. Transplant candidates who were evaluated by our program's Hispanic Transplant Program were referred for expanded infectious disease screening including Mycobacterium tuberculosis, S. stercoralis, Leishmania, and T. cruzi. Between December 2006 and December 2008, 83 patients were screened. Most were from Mexico but we also screened patients from Ecuador, Puerto Rico, and Peru. Most patients lived in urban locations before moving to the United States. Latent tuberculosis infection (LTBI) was found in 20%, and 6.7% had serologic evidence of S. stercoralis infection. These patients underwent treatment of latent infection without di⁄culty. To date, 14 patients have undergone living-donor kidney transplantation. Two of these patients had positive Leishmania titers and are being followed clinically, 1 was treated for S. stercoralis, and 2 were treated for LTBI pre-transplant. All have done well without evidence of screened pathogens an average of 348 days (range 65^766 days) post transplant. Expanded screening identi¢es endemic infections in the Hispanic immigrant population that can be treated before transplant, thereby minimizing post-transplant infectious complications.

Research paper thumbnail of Ethnic advantages in kidney transplant outcomes: the Hispanic Paradox at work?

Nephrology Dialysis Transplantation, 2008

1-year survival rates surpassing 91%, long-term graft survival remains inadequate [1]. The 3-year... more 1-year survival rates surpassing 91%, long-term graft survival remains inadequate [1]. The 3-year, 5-year and 10-year deceased donor unadjusted graft survival rates are 78.6%, 67.1% and 40.8%, respectively, among all kidney recipients in the United States (USA) [2]. The loss of transplanted grafts is a major public health problem. Kidney transplantation is the treatment of choice for most patients with end-stage renal disease (ESRD) since it provides a longer length of life, better quality of life [3,4] and is more cost-effective than dialysis [5,6]. When kidney grafts fail, patients return to dialysis, creating an even greater demand for scarce kidney (re-)transplants and further burdening society with greater costs [7-9]. Mortality rates on dialysis following a failed kidney transplant are

Research paper thumbnail of Unresectable solitary hepatocellular carcinoma not amenable to radiofrequency ablation: Multicenter radiology-pathology correlation and survival of radiation segmentectomy

Hepatology, 2014

Resection and radiofrequency ablation (RFA) are treatment options for hepatocellular carcinoma (H... more Resection and radiofrequency ablation (RFA) are treatment options for hepatocellular carcinoma (HCC) <3 cm; there is interest in expanding the role of ablation to 3-5 cm. RFA is considered high-risk when the lesion is in close proximity to critical structures. Combining microcatheter technology and the localized emission properties of Y90, highly selective radioembolization is a possible alternative to RFA in such cases. We assessed the efficacy (response, radiology-pathology correlation, survival) of radiation segmentectomy in solitary HCC not amenable to RFA or resection. Patients with treatment-naïve, unresectable, solitary HCC ≤ 5 cm not amenable to RFA were included in this multicenter study. Administered dose, response rate, time-to-progression (modified Response Evaluation Criteria in Solid Tumors [mRECIST]), radiology-pathology correlation and long-term survival were assessed. In all, 102 patients were included in this study. mRECIST complete response (CR), partial response (PR), and stable disease (SD) were 47/99 (47%), 39/99 (39%), and 12/99 (12%), respectively. Median time-to-disease-progression was 33.1 months. In all, 33/102 (32%) patients were transplanted with a median (interquartile range [IQR]) time-to-transplantation of 6.3 months (3.6-9.7). Pathology revealed 100% and 50-99% necrosis in 17/33 (52%) and 16/33 (48%), respectively. Median overall survival was 53.4 months. Univariate analysis demonstrated a survival benefit for Eastern Cooperative Oncology Group (ECOG) 0 patients. In the multivariate model, age <65, ECOG 0, and Child-Pugh A were…

Research paper thumbnail of NUTORC—a transdisciplinary health services and outcomes research team in transplantation

Translational Behavioral Medicine, 2012

The field of solid organ transplantation has historically concentrated research efforts on basic ... more The field of solid organ transplantation has historically concentrated research efforts on basic science and translational studies. However, there has been increasing interest in health services and outcomes research. The aim was to build an effective and sustainable, inter-and transdisciplinary health services and outcomes research team (NUTORC), that leveraged institutional strengths in social science, engineering, and management disciplines, coupled with an international recognized transplant program. In 2008, leading methodological experts across the university were identified and intramural funding was obtained for the NUTORC initiative. Inter-and transdisciplinary collaborative teams were created across departments and schools within the university. Within 3 years, NUTORC became fiscally sustainable, yielding more than tenfold return of the initial investment. Academic productivity included funding for 39 grants, publication of 60 manuscripts, and 166 national presentations. Sustainable educational opportunities for students were created. Inter-and transdisciplinary health services and outcomes research in transplant can be innovative and sustainable.

Research paper thumbnail of Long Term Outcomes of Hispanic Liver Transplant Recipients - The Hispanic Paradox

American Journal of Transplantation

Research paper thumbnail of Long-Term Outcomes of Pediatric Kidney Transplantation in Hispanics

American Journal of Transplantation

Research paper thumbnail of Investigating the role of feedstock properties and process conditions on products formed during the hydrothermal carbonization of organics using regression techniques

Bioresource Technology, 2015

The purpose of this study is to develop regression models that describe the role of process condi... more The purpose of this study is to develop regression models that describe the role of process conditions and feedstock chemical properties on carbonization product characteristics. Experimental data were collected and compiled from literature-reported carbonization studies and subsequently analyzed using two statistical approaches: multiple linear regression and regression trees. Results from these analyses indicate that both the multiple linear regression and regression tree models fit the product characteristics data well. The regression tree models provide valuable insight into parameter relationships. Relative weight analyses indicate that process conditions are more influential to the solid yields and liquid and gas-phase carbon contents, while feedstock properties are more influential on the hydrochar carbon content, energy content, and the normalized carbon content of the solid.

Research paper thumbnail of Use of Wireless Smart Sensors for Detecting Human Falls through Structural Vibrations

Conference Proceedings of the Society for Experimental Mechanics Series, 2011

Falls are the leading cause of accidental deaths for people over the age of 65 because of the fal... more Falls are the leading cause of accidental deaths for people over the age of 65 because of the fall, fall related injury itself or related complications including hypothermia, dehydration, pressure sores and pneumonia. Several fall detection systems are commercially available including Life Alert, Life Link, and Alert One where the person wears a pendant that can be pressed in the case of an emergency or with newer models activates automatically when there is no motion. Pendant-based emergency systems become ineffective if the person is not wearing the pendant (refuses or forgets) or cannot press the pendant's button, for example when falling in a prone position on top of the device. In addition, the elderly are hesitant to use emergency systems for several reasons such as the concern of bothering others and personal pride. This paper proposes the use of structural vibrations to determine if a person has fallen. An Imote2 and an ITS400CA sensor board are used for the collection of structural vibrations induced by human activity, including falls. These sensors are discrete, and have shown potential for the data collection and diagnostic processing needed to detect human falls. The use of wireless smart sensors in the structure provides a non-intrusive method for human fall detection that does not require the use of any device by the person. A preliminary study of the classification of human induced vibration in a typical structure using traditional wired sensors is also discussed as well as a sensing framework used to study structural vibrations induced by human falls.

Research paper thumbnail of Bayesian Finite Element Model Updating Using Static and Dynamic Data

Conference Proceedings of the Society for Experimental Mechanics Series, 2011

Finite element models of current structures often behave differently than the structure itself. M... more Finite element models of current structures often behave differently than the structure itself. Model updating techniques are used to enhance the capabilities of the numerical model such that it behaves like the real structure. Experimental data is used in model updating techniques to identify the parameters of the numerical model. In civil infrastructure these model updating techniques use either static or dynamic measurements, separately. This paper studies how a Bayesian updating framework behaves when both static and ...

Research paper thumbnail of Content-based medical image retrieval using Low-Level visual features and modality identification

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2008

This paper presents the image retrieval results obtained by the BioIngenium Research Group, in th... more This paper presents the image retrieval results obtained by the BioIngenium Research Group, in the frame of the ImageCLEFmed 2007 edition. The applied approach consists of two main phases: a preprocessing phase, which builds an image category index and a retrieval phase, which ranks similar images. Both phases are based only on visual information. The experiments show a consistent frame with theory in content-based image retrieval: filtering images with a conceptual index outperforms only-ranking-based strategies; combining features is better than using individual features; and low-level features are not enough to model image semantics.

Research paper thumbnail of Quantification of fatigue cracking in CT specimens with passive and active piezoelectric sensing

Monitoring of fatigue cracks in steel bridges is of interest to bridge owners and agencies. Monit... more Monitoring of fatigue cracks in steel bridges is of interest to bridge owners and agencies. Monitoring of fatigue cracks has been attempted with acoustic emission using either resonant or broadband sensors. One drawback of passive sensing is that the data is limited to that caused by growing cracks. In this work, passive emission was complemented with active sensing (piezoelectric wafer active sensors) for enhanced detection capabilities. Passive and active sensing methods were described for fatigue crack monitoring on specialized compact tension specimens. The characteristics of acoustic emission were obtained to understand the correlation of acoustic emission behavior and crack growth. Crack and noise induced signals were interpreted through Swansong II Filter and waveform-based approaches, which are appropriate for data interpretation of field tests. Upon detection of crack extension, active sensing was activated to measure the crack size. Model updating techniques were employed to minimize the difference between the numerical results and experimental data. The long term objective of this research is to develop an in-service prognostic system to monitor structural health and to assess the remaining fatigue life.

Research paper thumbnail of Model updating and prognosis of acoustic emission data in compact test specimens under cyclic loading

abstract Acoustic emission (AE) is generated when cracks develop and it is used as an indicator o... more abstract Acoustic emission (AE) is generated when cracks develop and it is used as an indicator of the current state of damage in structural elements. Algorithms that use AE data to predict the state of a structural element are still in their research stages because the relationship between crack length and AE activity is not well understood. The process of trying to predict the future stage of a crack based on AE data is usually performed by an expert, and requires significant experience. This paper proposes a new strategy for the ...