Effect of the Gamma-Ray Irradiation on the Properties of an Epoxy Encapsulant

The influence of 60Co gamma-ray irradiation on the chemical compositions and properties of an epoxy encapsulant was investigated. The total irradiation dose varied from 0.1 kGy to 100 kGy with a fixed dose rate of 500 Gy/h. Fourier transform infrared spectra, X-ray photoelectron spectroscopy analysis and discoloration proved the occurrence of oxidation caused by the irradiation. Tg and density remained unchanged owing to the competing effects of irradiation-induced degradation and crosslinking. The tensile strength, impact strength and electrical strength did not decrease distinctly until the irradiation dose reached above 11 kGy. Rubbery coefficient of linear thermal expansion (CTE), relative permittivity and dissipation factor, on the contrary, were more sensitive to the oxidation and increased sharply when the irradiation dose was only 0.1 kGy. Our results suggested that the evolution of CTEs and dielectric properties could affect the long-term application and reliability of the epoxy encapsulant in the irradiative environment.

Phase II study of fixed dose-rate gemcitabine plus S-1 as second-line treatment in advanced biliary tract cancer.

301 Background: Cisplatin plus gemcitabine (GC) is considered as standard first-line chemotherapy for patients with advanced biliary tract cancer (BTC). However, no standard therapy is established for second-line setting. Some clinical studies showed that gemcitabine was more effective if administered by the fixed dose rate method, and S-1 had anti-tumor effect as second-line chemotherapy for BTC. We evaluated the efficacy and safety of combination therapy of fixed dose-rate gemcitabine and S-1 after failure of GC or gemcitabine alone. Methods: This study was a single arm phase II study, and primary endpoint was response rate (RR) with MinMax two stage design to test the hypothesis that RR was more than 7%. Number of patients needed was 35 with a power of 90% and two-sided α value of 0.05. Patients received gemcitabine (1,000 mg/m2, div, over 100 minutes, day 1) and S-1 (40 mg/m2 twice daily, oral, day 1-7), every two weeks until disease progression or intolerable adverse events. Results: Forty patients were enrolled from July, 2011 to Nov., 2014. Of 23 patients in the first stage, two patients showed response and proceeded to the second stage. Overall response rate was 7.5%. Overall survival, progression-free survival and disease control rate were 7.7 months, 2.6 months, and 47.5%, respectively. Common adverse events were anemia (97.2%), thrombocytopenia (66.7%), leukopenia (47.2%), neutropenia (41.7%), anorexia (39.0%) and fatigue (37.8%). Grade 3–4 adverse events were leukopenia (19.5%), neutropenia (19.5%), anemia (14.6%), thrombocytopenia (7.3%) and anorexia (4.8%). Biliary tract infection led to death in two patients; however, these were reported as not related to this study treatment. Conclusions: Fixed dose-rate gemcitabine plus S-1 was tolerable as second-line settings in BTC; however, its activity was modest for patients refractory to the standard gemcitabine. Clinical trial information: UMIN000005918 Clinical trial information: UMIN000005918.

A phase II study of biweekly gemcitabine at fixed dose rate infusion plus S1 as first-line chemotherapy in patients with locally advanced or metastatic pancreatic cancer.

357 Background: The combination regimen of gemcitabine plus S1 (GS) as first-line chemotherapy has shown good efficacy in advanced pancreatic cancer. However, it is inconvenient to deliver gemcitabine on days 1 and 8 within one treatment cycle. In addition, previous studies have demonstrated that the gemcitabine administration by fixed dose rate infusion of 10 mg/m2/min should maximize the rate of intracellular accumulation of gemcitabine triphosphate and might improve clinical efficacy. The aim of this study was to evaluate the efficacy and safety of biweekly gemcitabine at fixed dose rate infusion combined with S1 (FGS) in chemonaive patients with locally advanced or metastatic pancreatic cancer. Methods: Forty-three eligible patients with locally advanced or metastatic pancreatic cancer received gemcitabine at a fixed dose of 10 mg/m2/min intravenously over a 2-h period on day 1, together with oral S1 40mg/m2twice daily on days 1 to 10, every 2 weeks. Tumor assessment was performed for every 3 cycles of chemotherapy. Results: All patients were evaluable for toxicity and 42 patients for efficacy. The overall response rate was 35.7% with 1 complete response, 14 partial responses, 17 stable diseases, and 10 progressions. Median time to progression was 5.9 months and median overall survival was 9.6 months. The main grade 3/4 toxicities included neutropenia (30.2%), thrombocytopenia (6.9%), anemia (2.3%), nausea (4.6%), diarrhea (2.3%). Conclusions: The biweekly FGS regimen is active, well tolerated and conveniently delivered as first-line chemotherapy for patients with locally advanced or metastatic pancreatic cancer.