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Featured researches published by Kent T. Sato.


Gastroenterology | 2010

Radioembolization for Hepatocellular Carcinoma Using Yttrium-90 Microspheres: A Comprehensive Report of Long-term Outcomes

Riad Salem; Robert J. Lewandowski; Mary F. Mulcahy; Ahsun Riaz; Robert K. Ryu; S.M. Ibrahim; Bassel Atassi; Talia Baker; Vanessa L. Gates; Frank H. Miller; Kent T. Sato; E. D. Wang; Ramona Gupta; Al B. Benson; Steven Newman; Reed A. Omary; Michael Abecassis; Laura Kulik

BACKGROUND & AIMS Hepatocellular carcinoma (HCC) has limited treatment options; long-term outcomes following intra-arterial radiation are unknown. We assessed clinical outcomes of patients treated with intra-arterial yttrium-90 microspheres (Y90). METHODS Patients with HCC (n = 291) were treated with Y90 as part of a single-center, prospective, longitudinal cohort study. Toxicities were recorded using the Common Terminology Criteria version 3.0. Response rate and time to progression (TTP) were determined using World Health Organization (WHO) and European Association for the Study of the Liver (EASL) guidelines. Survival by stage was assessed. Univariate/multivariate analyses were performed. RESULTS A total of 526 treatments were administered (mean, 1.8; range, 1-5). Toxicities included fatigue (57%), pain (23%), and nausea/vomiting (20%); 19% exhibited grade 3/4 bilirubin toxicity. The 30-day mortality rate was 3%. Response rates were 42% and 57% based on WHO and EASL criteria, respectively. The overall TTP was 7.9 months (95% confidence interval, 6-10.3). Survival times differed between patients with Child-Pugh A and B disease (A, 17.2 months; B, 7.7 months; P = .002). Patients with Child-Pugh B disease who had portal vein thrombosis (PVT) survived 5.6 months (95% confidence interval, 4.5-6.7). Baseline age; sex; performance status; presence of portal hypertension; tumor distribution; levels of bilirubin, albumin, and alpha-fetoprotein; and WHO/EASL response rate predicted survival. CONCLUSIONS Patients with Child-Pugh A disease, with or without PVT, benefited most from treatment. Patients with Child-Pugh B disease who had PVT had poor outcomes. TTP and overall survival varied by patient stage at baseline. These data can be used to design future Y90 trials and to describe Y90 as a potential treatment option for patients with HCC.


Hepatology | 2007

Safety and Efficacy of 90Y Radiotherapy for Hepatocellular Carcinoma With and Without Portal Vein Thrombosis

Laura Kulik; Brian I. Carr; Mary F. Mulcahy; Robert J. Lewandowski; Bassel Atassi; Robert K. Ryu; Kent T. Sato; Al B. Benson; Albert A. Nemcek; Vanessa L. Gates; Michael Abecassis; Reed A. Omary; Riad Salem

This study was undertaken to present data from a phase 2 study in which patients with unresectable hepatocellular carcinoma (HCC) with and without portal vein thrombosis underwent radioembolization with Yttrium (90Y) microspheres. Patients treated were stratified by Okuda, Child‐Pugh, baseline bilirubin, tumor burden, Eastern Cooperative Oncology Group (ECOG), presence of cirrhosis and portal vein thrombosis (PVT) (none, branch, and main). Clinical and biochemical data were obtained at baseline and at 4‐week intervals following treatment for up to 6 months. Tumor response was obtained using computed tomography (CT). Patients were followed for survival. One hundred eight patients were treated during the study period. Thirty‐seven (34%) patients had PVT, 12 (32%) of which involved the main PV. The cumulative dose for those with and without PVT was 139.7 Gy and 131.9 Gy, respectively. The partial response rate using world Health Organization (WHO) criteria was 42.2%. Using European Association for the Study of the Liver (EASL), the response rate was 70%. Kaplan‐Meier survival varied depending on location of PVT and presence of cirrhosis. The adverse event (AE) rates were highest in patients with main PVT and cirrhosis. There were no cases of radiation pneumonitis. Conclusion: The use of minimally embolic 90Y glass microspheres to treat patients with HCC complicated by branch/lobar PVT may be clinically indicated and appears to have a favorable toxicity profile. Further investigation is warranted in patients with main PVT. (HEPATOLOGY 2007.)


Gastroenterology | 2011

Radioembolization results in longer time-to-progression and reduced toxicity compared with chemoembolization in patients with hepatocellular carcinoma

Riad Salem; Robert J. Lewandowski; Laura Kulik; Ahsun Riaz; Robert K. Ryu; Kent T. Sato; Ramona Gupta; Paul Nikolaidis; Frank H. Miller; Vahid Yaghmai; S.M. Ibrahim; Seanthan Senthilnathan; Talia Baker; Vanessa L. Gates; Bassel Atassi; Steven Newman; Khairuddin Memon; Richard Chen; Robert L. Vogelzang; Albert A. Nemcek; Scott A. Resnick; Howard B. Chrisman; James Carr; Reed A. Omary; Michael Abecassis; Al B. Benson; Mary F. Mulcahy

BACKGROUND & AIMS Chemoembolization is one of several standards of care treatment for hepatocellular carcinoma (HCC). Radioembolization with Yttrium-90 microspheres is a novel, transarterial approach to radiation therapy. We performed a comparative effectiveness analysis of these therapies in patients with HCC. METHODS We collected data from 463 patients who were treated with transarterial locoregional therapies (chemoembolization or radioembolization) over a 9-year period. We excluded patients who were not appropriate for comparison and analyzed data from 245 (122 who received chemoembolization and 123 who received radioembolization). Patients were followed for signs of toxicity; all underwent imaging analysis at baseline and follow-up time points. Overall survival was the primary outcome measure. Secondary outcomes included safety, response rate, and time-to-progression. Uni- and multivariate analyses were performed. RESULTS Abdominal pain and increased transaminase activity were more frequent following chemoembolization (P < .05). There was a trend that patients treated with radioembolization had a higher response rate than with chemoembolization (49% vs 36%, respectively, P = .104). Although time-to-progression was longer following radioembolization than chemoembolization (13.3 months vs 8.4 months, respectively, P = .046), median survival times were not statistically different (20.5 months vs 17.4 months, respectively, P = .232). Among patients with intermediate-stage disease, survival was similar between groups that received chemoembolization (17.5 months) and radioembolization (17.2 months, P = .42). CONCLUSIONS Patients with HCC treated by chemoembolization or radioembolization with Yttrium-90 microspheres had similar survival times. Radioembolization resulted in longer time-to-progression and less toxicity than chemoembolization. Post hoc analyses of sample size indicated that a randomized study with > 1000 patients would be required to establish equivalence of survival times between patients treated with these two therapies.


American Journal of Transplantation | 2009

A Comparative Analysis of Transarterial Downstaging for Hepatocellular Carcinoma: Chemoembolization Versus Radioembolization

Robert J. Lewandowski; Laura Kulik; Ahsun Riaz; Seanthan Senthilnathan; Mary F. Mulcahy; Robert K. Ryu; S.M. Ibrahim; Kent T. Sato; Talia Baker; Frank H. Miller; Reed A. Omary; Michael Abecassis; Riad Salem

Chemoembolization and other ablative therapies are routinely utilized in downstaging from United Network for Organ Sharing (UNOS) T3 to T2, thus potentially making patients transplant candidates under the UNOS model for end‐stage liver disease (MELD) upgrade for hepatocellular carcinoma (HCC). This study was undertaken to compare the downstaging efficacy of transarterial chemoembolization (TACE) versus transarterial radioembolization. Eighty‐six patients were treated with either TACE (n = 43) or transarterial radioembolization with Yttrium‐90 microspheres (TARE‐Y90; n = 43). Median tumor size was similar (TACE: 5.7 cm, TARE‐Y90: 5.6 cm). Partial response rates favored TARE‐Y90 versus TACE (61% vs. 37%). Downstaging to UNOS T2 was achieved in 31% of TACE and 58% of TARE‐Y90 patients. Time to progression according to UNOS criteria was similar for both groups (18.2 months for TACE vs. 33.3 months for TARE‐Y90, p = 0.098). Event‐free survival was significantly greater for TARE‐Y90 than TACE (17.7 vs. 7.1 months, p = 0.0017). Overall survival favored TARE‐Y90 compared to TACE (censored 35.7/18.7 months; p = 0.18; uncensored 41.6/19.2 months; p = 0.008). In conclusion, TARE‐Y90 appears to outperform TACE for downstaging HCC from UNOS T3 to T2.


Journal of Vascular and Interventional Radiology | 2009

Complications Following Radioembolization with Yttrium-90 Microspheres: A Comprehensive Literature Review

Ahsun Riaz; Robert J. Lewandowski; Laura Kulik; Mary F. Mulcahy; Kent T. Sato; Robert K. Ryu; Reed A. Omary; Riad Salem

The past decade has seen significant advancement in the locoregional management of liver tumors; novel and promising therapies such as transarterial chemoembolization, radioembolization, and radiofrequency ablation are now available. The development of new techniques and devices has led to the improved safety and efficacy profiles of external-beam radiation. Radioembolization with yttrium-90 ((90)Y) microspheres has emerged as a safe and efficacious treatment modality for liver malignancies. The purpose of this article is to present a comprehensive evidence-based review of the complications and adverse events that may be associated with radioembolization with (90)Y microspheres. Strategies to mitigate these adverse events are also discussed.


CardioVascular and Interventional Radiology | 2007

Radioembolization with 90Y Microspheres: Angiographic and Technical Considerations

Robert J. Lewandowski; Kent T. Sato; Bassel Atassi; Robert K. Ryu; Albert A. Nemcek; Laura Kulik; Jean Francois H Geschwind; Ravi Murthy; William S. Rilling; David M. Liu; Lourens Bester; José Ignacio Bilbao; Andrew S. Kennedy; Reed A. Omary; Riad Salem

The anatomy of the mesenteric system and the hepatic arterial bed has been demonstrated to have a high degree of variation. This is important when considering pre-surgical planning, catheterization, and trans-arterial hepatic therapies. Although anatomical variants have been well described, the characterization and understanding of regional hepatic perfusion in the context of radioembolization have not been studied with great depth. The purpose of this review is to provide a thorough discussion and detailed presentation of the angiographic and technical aspects of radioembolization. Normal vascular anatomy, commonly encountered variants, and factors involved in changes to regional perfusion in the presence of liver tumors are discussed. Furthermore, the principles described here apply to all liver-directed transarterial therapies.


Hepatology | 2009

Radiologic–pathologic correlation of hepatocellular carcinoma treated with internal radiation using yttrium‐90 microspheres

Ahsun Riaz; Laura Kulik; Robert J. Lewandowski; Robert K. Ryu; Georgia Giakoumis Spear; Mary F. Mulcahy; Michael Abecassis; Talia Baker; Vanessa L. Gates; Ritu Nayar; Frank H. Miller; Kent T. Sato; Reed A. Omary; Riad Salem

We present the correlation between radiologic and pathologic findings in HCC patients who underwent radioembolization with yttrium‐90 (90Y) microspheres prior to resection or transplantation. Thirty‐five patients with a total of 38 lesions who underwent liver explantation after 90Y radioembolization were studied. Imaging surrogates following treatment were evaluated; the explants were examined for assessment of necrosis by pathology. The correlation betwen radiologic and histologic findings of the treated lesions was analyzed. Twenty‐three of 38 (61%) target lesions showed complete pathologic necrosis. All target lesions demonstrated some degree of histologic necrosis at explant. Complete histologic necrosis was seen in 89% of lesions with pretreatment size <3 cm. Complete pathologic necrosis was seen in 100%, 78%, and 93% of the lesions that were shown to have complete response by European Association for the Study of the Liver (EASL) necrosis criteria, partial response by World Health Organizaton (WHO) criteria, or thin rim enhancement on posttreatment imaging, respectively. In contrast, complete pathologic necrosis was seen in only 52% and 38% of the lesions that showed partial response by EASL criteria and peripheral nodular enhancement, respectively. Conclusion: Post‐radioembolization imaging findings of response by EASL and WHO criteria are predictive of the degree of pathologic necrosis. Rim enhancement was an imaging characteristic that correlated well with histologic necrosis. (HEPATOLOGY 2009.)


Radiology | 2008

Unresectable chemorefractory liver metastases: radioembolization with 90Y microspheres--safety, efficacy, and survival.

Kent T. Sato; Robert J. Lewandowski; Mary F. Mulcahy; Bassel Atassi; Robert K. Ryu; Vanessa L. Gates; Albert A. Nemcek; Omar Barakat; Al B. Benson; Robert Mandal; Mark S. Talamonti; Ching Yee O. Wong; Frank H. Miller; Steven Newman; John M. Shaw; Kenneth G. Thurston; Reed A. Omary; Riad Salem

PURPOSE To prospectively evaluate the safety, efficacy, and survival of patients with chemorefractory liver metastases who have been treated with yttrium 90 ((90)Y) glass microspheres. MATERIALS AND METHODS Institutional review boards from two institutions approved the HIPAA-compliant study; all patients provided informed consent. One hundred thirty-seven patients underwent 225 administrations of (90)Y microspheres by using intraarterial infusion. Primary sites (origins) included colon, breast, neuroendocrine, pancreas, lung, cholangiocarcinoma, melanoma, renal, esophageal, ovary, adenocarcinoma of unknown primary, lymphoma, gastric, duodenal, bladder, angiosarcoma, squamous cell carcinoma, thyroid, adrenal, and parotid. Patients underwent evaluation of baseline and follow-up liver function and tumor markers and computed tomographic or magnetic resonance imaging. Patients were observed for survival from first treatment. Median survival (in days) and corresponding 95% confidence intervals were computed by using the Kaplan-Meier method. The log-rank statistic was used for statistical significance testing of survival distributions between various subgroups of patients. RESULTS There were 66 men and 71 women. All patients were treated on an outpatient basis. Median age was 61 years. The mean number of treatments was 1.6. The median activity and dose infused were 1.83 GBq and 112.8 Gy, respectively. Clinical toxicities included fatigue (56%), vague abdominal pain (26%), and nausea (23%). At follow-up imaging, according to World Health Organization criteria, there was a 42.8% response rate (2.1% complete response, 40.7% partial response). There was a biologic tumor response (any decrease in tumor size) of 87%. Overall median survival was 300 days. One-year survival was 47.8%, and 2-year survival was 30.9%. Median survival was 457 days for patients with colorectal tumors, 776 days for those with neuroendocrine tumors, and 207 days for those with noncolorectal, nonneuroendocrine tumors. CONCLUSION (90)Y hepatic treatments are well tolerated with acceptable toxicities; tumor response and median survival are promising.


CardioVascular and Interventional Radiology | 2006

Treatment of Unresectable Primary and Metastatic Liver Cancer with Yttrium-90 Microspheres (TheraSphere®): Assessment of Hepatic Arterial Embolization

Kent T. Sato; Robert J. Lewandowski; James T. Bui; Reed A. Omary; Russell D. Hunter; Laura Kulik; Mary F. Mulcahy; David M. Liu; Howard B. Chrisman; Scott A. Resnick; Albert A. Nemcek; Robert L. Vogelzang; Riad Salem

In Canada and Europe, yttrium-90 microspheres (TheraSphere®; MDS Nordion, Ottawa, Canada) are a primary treatment option for primary and secondary hepatic malignancies. We present data from 30 patients with hepatocellular carcinoma (HCC) and metastatic liver disease treated with TheraSphere from a single academic institution to evaluate the angiographically evident embolization that follows treatment. Seven interventional radiologists from one treatment center compared pretreatment and posttreatment angiograms. The reviewers were blinded to the timing of the studies. The incidence of postembolization syndrome (PES) was determined as well as objective tumor response rates by the World Health Organization (WHO), Response Evaluation Criteria in Solid Tumors (RECIST), and European Association for the Study of the Liver (EASL) criteria. There were 420 independent angiographic observations that were assessed using the chi-squared statistic. The pretreatment and posttreatment angiograms could not be correctly identified on average more than 43% of the time (p = 0.0004). The postprocedure arterial patency rate was 100%. The objective tumor response rates for all patients were 24%, 31%, and 72% for WHO, RECIST, and EASL criteria, respectively. All of the patients tolerated the procedure without complications and were treated on an outpatient basis, and four patients had evidence of PES. This treatment method does not result in macroscopic embolization of the hepatic arteries, thereby maintaining hepatic tissue perfusion. These data support the principle that the favorable response rates reported with TheraSphere are likely due to radiation and microscopic embolization rather than flow-related macroscopic embolization and ischemia.


Journal of Clinical Oncology | 2009

Alpha-Fetoprotein Response After Locoregional Therapy for Hepatocellular Carcinoma: Oncologic Marker of Radiologic Response, Progression, and Survival

Ahsun Riaz; Robert K. Ryu; Laura Kulik; Mary F. Mulcahy; Robert J. Lewandowski; Jeet Minocha; S.M. Ibrahim; Kent T. Sato; Talia Baker; Frank H. Miller; Steven Newman; Reed A. Omary; Michael Abecassis; Al B. Benson; Riad Salem

PURPOSE Alpha-fetoprotein (AFP) is considered to be an indicator of tumor activity in hepatocellular carcinoma (HCC). We present a novel correlation of AFP response to radiologic response, time-to-progression (TTP), progression-free survival (PFS), and overall survival (OS) in patients treated with locoregional therapies. PATIENTS AND METHODS Four hundred sixty-three patients with HCC were treated with chemoembolization or radioembolization at our institution. One hundred twenty-five patients with baseline AFP higher than 200 ng/mL were studied for this analysis. AFP response was defined as more than 50% decrease from baseline. One hundred nineteen patients with follow-up imaging were studied for the AFP imaging correlation analysis. AFP response was correlated to radiologic response, TTP, PFS, and OS. Multivariate analyses were performed. RESULTS Eighty-one patients (65%) showed AFP response. AFP response was seen in 26 (55%) of 47 and 55 (70%) of 78 of patients treated with chemoembolization and radioembolization, respectively (P = .12). WHO response was seen in 41 (53%) of 77 and 10 (24%) of 42 of AFP responders and nonresponders, respectively (P = .002). The hazard ratio (HR) for TTP in AFP nonresponders compared with responders was 2.8 (95% CI, 1.5 to 5.1). The HR for PFS was 4.2 (95% CI, 2.4 to 7.2) in AFP nonresponders compared with responders. The HR for OS in AFP nonresponders compared with responders was 5.5 (95% CI, 3.1 to 9.9) and 2.7 (95% CI, 1.6 to 4.6) on univariate and multivariate analyses, respectively. CONCLUSION The data presented support the use of AFP response seen after locoregional therapy as an ancillary method of assessing tumor response and survival, as well as an early objective screening tool for progression by imaging.

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Riad Salem

Northwestern University

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Laura Kulik

Northwestern University

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Ahsun Riaz

Northwestern University

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S.M. Ibrahim

Northwestern University

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