Hsiou-Shan Tseng

Parallel second stent placement for refractory ureteral stent malfunction in malignant ureteral obstruction.

PURPOSE To review retrospectively the outcome of placement of a parallel second ureteral stent in patients with urinary obstruction secondary to a malignancy. MATERIALS AND METHODS During the period 2005-2008, the medical records of patients with ureteral obstruction from an abdominal malignancy were reviewed. Patients who experienced malfunction of the first ureteral stent subsequently underwent either initial stent exchange (control group) or a parallel second ureteral stent placement. The outcomes of both groups were evaluated in terms of stent function at 1 week, 1 month, and 3 months after the procedure. Several clinical and imaging parameters were also compared between the two groups. RESULTS The stent malfunction rate increased more rapidly in the control group. In 1 week, the malfunction rate was 29.4% in the parallel ureteral stent group and 56.7% in the control group. By the end of the third month, the malfunction rate was 72.7% in the parallel ureteral stent group and 100% in the control group. The creatinine level after the procedure was significantly lower in the parallel ureteral stent group (P = 0.004). The incidence of symptomatic urinary tract infection (UTI) was around 30% in both groups (P = 1.000). CONCLUSIONS Parallel second ureteral stent placement has a high technical success rate. For terminally ill patients who have a malignancy and an occluded ureteral stent, the technique can effectively relieve obstruction and prolong the function of the stent.

Outcome of foreign residents undergoing deceased donor liver transplantation in China: A single-center experience in Taiwan

Foreign residents seeking liver transplantation in China are not uncommon. The outcomes of these people have not been well reported, and the results remain unclear. A total of 64 adults [26 with end‐stage liver disease (ESLD) and 38 with hepatocellular carcinoma (HCC)] who underwent donation after cardiac death (DCD) liver transplantation in China during a 5‐year period were reviewed. The median follow‐up period was 15.6 months. The estimated 3‐month mortality rate was 4.7%. The overall survival (OS) rate of the entire patient group at 1 and 3 years was 80.3% and 63.6%, respectively. The 1‐ and 3‐year graft survival rates were 78.5% and 64.4%, respectively. For ESLD, the 1‐ and 3‐year OS rates were 82.5% and 82.5%, respectively. For HCC, the 1‐ and 3‐year survival rates were 78.3% and 50.8%, respectively. The 1‐ and 3‐year OS rates for the HCC patients who were beyond the Milan criteria (MC; n = 24) versus those who met the MC (n = 14) were 69.8% and 28.2% versus 92.9% and 92.9% (P = 0.0032). The 1‐ and 3‐year disease‐free survival rates for those beyond the MC versus those who met the MC were 56.8% and 39.0% versus 92.3% and 92.3% (P = 0.0089). The incidence of complications was 59.4%. Biliary complications (n = 24, 37.5%), vascular complications (n = 24, 37.5%), and infection (n = 16, 25%) were the 3 most frequent transplant‐related complications. There were 10 patients with unsolved biliary complications, and a total of 5 patients died of posttransplant infections. In conclusion, patients with ESLD or HCC within the MC seeking DCD liver transplants in China obtained survival results comparable to those of other major cohorts from Western countries. However, a considerably high incidence of biliary complications, vascular complications, and infection substantially threatening the lives of patients is notable. Furthermore, the associated cost impact on medical resource utilization should not be overlooked. Liver Transpl 15:1579–1585, 2009.

A bidirectional approach for portal vein stent placement in a child with complete portal vein occlusion after living donor liver transplantation

Delayed PV complications are not rare in pediatric liver transplantation. Although PTPV offers a treatment and minimizes surgical revision, in case of complete PV thrombosis (PVT), the failure rate of PTPV is high. Herein, we report a successful technique of PTPV in a case of complete PVT with a stent placement using a bidirectional approach in a child with living donor liver transplantation.

Model-Based Radiation Dose Correction for Yttrium-90 Microsphere Treatment of Liver Tumors With Central Necrosis

PURPOSE The objectives of this study were to model and calculate the absorbed fraction ϕ of energy emitted from yttrium-90 ((90)Y) microsphere treatment of necrotic liver tumors. METHODS AND MATERIALS The tumor necrosis model was proposed for the calculation of ϕ over the spherical shell region. Two approaches, the semianalytic method and the probabilistic method, were adopted. In the former method, the range--energy relationship and the sampling of electron paths were applied to calculate the energy deposition within the target region, using the straight-ahead and continuous-slowing-down approximation (CSDA) method. In the latter method, the Monte Carlo PENELOPE code was used to verify results from the first method. RESULTS The fraction of energy, ϕ, absorbed from (90)Y by 1-cm thickness of tumor shell from microsphere distribution by CSDA with complete beta spectrum was 0.832 ± 0.001 and 0.833 ± 0.001 for smaller (r(T) = 5 cm) and larger (r(T) = 10 cm) tumors (where r is the radii of the tumor [T] and necrosis [N]). The fraction absorbed depended mainly on the thickness of the tumor necrosis configuration, rather than on tumor necrosis size. The maximal absorbed fraction φ that occurred in tumors without central necrosis for each size of tumor was different: 0.950 ± 0.000, and 0.975 ± 0.000 for smaller (r(T) = 5 cm) and larger (r(T) = 10 cm) tumors, respectively (p < 0.0001). CONCLUSIONS The tumor necrosis model was developed for dose calculation of (90)Y microsphere treatment of hepatic tumors with central necrosis. With this model, important information is provided regarding the absorbed fraction applicable to clinical (90)Y microsphere treatment.

Combined Yttrium-90 microsphere selective internal radiation therapy and external beam radiotherapy in patients with hepatocellular carcinoma: From clinical aspects to dosimetry

Purpose Selective internal radiation therapy (SIRT) is an effective treatment strategy for unresectable hepatocellular carcinoma (HCC) patients. However, the prognoses of patients with portal vein thrombosis, extra-hepatic metastases, or residual tumors remain poor when treated with SIRT alone. In these patients, sequential external beam radiotherapy (EBRT) may offer a chance of salvage. Here, we reported the clinical outcomes and the detailed dosimetry analysis of 22 patients treated with combination therapy. Methods Between October 2011 and May 2015, 22 consecutive patients who underwent EBRT after yttrium-90 (90Y) SIRT were included in this study. The post-SIRT 90Y bremsstrahlung SPECT/CT of each patient was transferred to dose distribution by adopting the local deposition hypothesis. The patient-specific 3-dimensional biological effective dose distribution of combined SIRT and EBRT was generated. The overall survival and safety were evaluated. The relationship between dosimetric parameters and liver toxicity was analyzed. Results The mean administered activity of SIRT was 1.50 GBq (range: 0.5–2.8). The mean prescribed dose of EBRT was 42.3 Gy (range: 15–63) in 14 fractions (range: 5–15) and was targeted to the residual liver tumor in 12 patients (55%), portal vein thrombosis in 11 patients (50%), and perihilar lymphadenopathies in 4 patients (18%). The overall 1-, 2-, and 3-year survival rates were 59.8%, 47.9%, and 47.9%, respectively. Overall, 8 patients (36%) developed > grade 2 liver toxicities, and the Child-Pugh score prior to EBRT strongly affected the toxicity risk. A dosimetry analysis restricted to 18 Child-Pugh A/B patients showed that the V100 (The fraction of normal liver exposed to more than 100 Gy) to V140 significance differed between patients who did or did not experience hepatotoxicity. The V110 was the strongest predictor of hepatotoxicity (18.6±11.6% vs 29.5±5.8%; P = 0.030). Conclusion Combined therapy is feasible and safe if patients are carefully selected. Specifically, 3-dimensional dosimetry is crucial for the evaluation of efficacy and toxicity. The normal liver V100 to V140 values of the combined dose should be as low as possible to minimize the risk of liver toxicity.

The Effectiveness of ART Score in Selecting Patients for Transarterial Chemoembolization Retreatment: A Cohort Study in Taiwan.

AbstractThe major issue in selecting patients for transarterial chemoembolization (TACE) lies in determining the optimal number of TACE sessions that may benefit patients before switching to other therapies. This is often a subjective decision not based on any standardized protocol. The ART (Assessment for Retreatment with Transarterial chemoembolization) score was recently developed to determine patients who may benefit from multiple sessions of TACE for treatment of hepatocellular carcinoma. The primary aim of the study was to validate the ART score in a Taiwanese cohort. The secondary aims were to evaluate overall survival and clinical determinants of improved survival in patients treated with multiple TACE sessions. The ART score, clinical characteristics, and outcomes of 82 patients with hepatocellular carcinoma who received multiple TACE sessions at Taipei Veterans General Hospital from September 2007 to July 2013 were analyzed. Among the 82 patients evaluated, 69.5% (n = 57) had an ART score of 0 to 1.5 and 34.1% (n = 25) had a score of ≥2.5. The median overall survival was 23.1 months and the overall mortality rate was 62.2% (n = 51). The ART score was not associated with survival (P = 0.58). Multivariate Cox regression analysis revealed that tumor size >7.2 cm (hazard ratio 4.44, P < 0.001), aspartate transaminase (AST) level above 95 IU/L (hazard ratio 2.18, P = 0.02), AST increase more than 25% (hazard ratio 2.13, P = 0.02), 2nd/1st (pre-TACE) alpha-fetoprotein ratio (hazard ratio 1.40, P = 0.001), and lack of radiological response to TACE (hazard ratio 2.21, P = 0.02) were independent clinical determinants of survival. The ART score was not found to be effective in selecting patients for TACE retreatment in our Taiwanese cohort. Large tumor size, high AST level, high 2nd/1st (pre-TACE) alpha-fetoprotein ratio, AST increase >25%, and lack of radiological response to TACE were independently associated with shorter survival after TACE therapy.