Scintillation Characteristics of the Single-Crystalline Film and Composite Film-Crystal Scintillators Based on the Ce3+-Doped (Lu,Gd)3(Ga,Al)5O12 Mixed Garnets under Alpha and Beta Particles, and Gamma Ray Excitations.

The crystals of (Lu,Gd)3(Ga,Al)5O12 multicomponent garnets with high density ρ and effective atomic number Zeff are characterized by high scintillation efficiency and a light yield value up to 50,000 ph/MeV. During recent years, single-crystalline films and composite film/crystal scintillators were developed on the basis of these multicomponent garnets. These film/crystal composites are potentially applicable for particle identification by pulse shape discrimination due to the fact that α-particles excite only the film response, γ-radiation excites only the substrate response, and ß-particles excite both to some extent. Here, we present new results regarding scintillating properties of selected (Lu,Gd)3(Ga,Al)5O12:Ce single-crystalline films under excitation by alpha and beta particles and gamma ray photons. We conclude that some of studied compositions are indeed suitable for testing in the proposed application, most notably Lu1.5Gd1.5Al3Ga2O12:Ce film on the GAGG:Ce substrate, exhibiting an α-particle-excited light yield of 1790-2720 ph/MeV and significantly different decay curves excited by α- and γ-radiation.

The use of Pantherpix pixel detector in radiotherapy QA.

There are various different detectors, which can be used for radiotherapy measurements, and more are about to be adopted. Hybrid pixel detectors (HPD) have been originally developed for the high energy physics. However, over the last few years they also expanded in the medical physics. Novel 2D detector Pantherpix is a HPD designed specifically for the radiotherapy. In this article, its properties are characterised and an assessment of its use in radiotherapy photon beams is provided. Properties such as response stability, response linearity, angular dependence and energy dependence were studied. In order to prove sufficient clinical quality for relative dosimetry, further measurements were undertaken (i.e. dose profiles and collimator scatter factors). Acquired results were compared with ion chamber and gafchromic film results. Namely the applicability of PhPix for cobalt beam therapy, which is still widely used (and will be used in near future) in economically less developed countries, is considered.

Scintillation Response Enhancement in Nanocrystalline Lead Halide Perovskite Thin Films on Scintillating Wafers.

Lead halide perovskite nanocrystals of the formula CsPbBr3 have recently been identified as potential time taggers in scintillating heterostructures for time-of-flight positron emission tomography (TOF-PET) imaging thanks to their ultrafast decay kinetics. This study investigates the potential of this material experimentally. We fabricated CsPbBr3 thin films on scintillating GGAG:Ce (Gd2.985Ce0.015Ga2.7Al2.3O12) wafer as a model structure for the future sampling detector geometry. We focused this study on the radioluminescence (RL) response of this composite material. We compare the results of two spin-coating methods, namely the static and the dynamic process, for the thin film preparation. We demonstrated enhanced RL intensity of both CsPbBr3 and GGAG:Ce scintillating constituents of a composite material. This synergic effect arises in both the RL spectra and decays, including decays in the short time window (50 ns). Consequently, this study confirms the applicability of CsPbBr3 nanocrystals as efficient time taggers for ultrafast timing applications, such as TOF-PET.

Novel and potent anti-tumor and anti-metastatic di-2-pyridylketone thiosemicarbazones demonstrate marked differences in pharmacology between the first and second generation lead agents.

Di(2-pyridyl)ketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di(2-pyridyl)ketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) are novel, highly potent and selective anti-tumor and anti-metastatic drugs. Despite their structural similarity, these agents differ in their efficacy and toxicity in-vivo. Considering this, a comparison of their pharmacokinetic and pharmaco/toxico-dynamic properties was conducted to reveal if these factors are involved in their differential activity. Both compounds were administered to Wistar rats intravenously (2 mg/kg) and their metabolism and disposition were studied using UHPLC-MS/MS. The cytotoxicity of both thiosemicarbazones and their metabolites was also examined using MCF-7, HL-60 and HCT116 tumor cells and 3T3 fibroblasts and H9c2 cardiac myoblasts. Their intracellular iron-binding ability was characterized by the Calcein-AM assay and their iron mobilization efficacy was evaluated. In contrast to DpC, Dp44mT undergoes rapid demethylation in-vivo, which may be related to its markedly faster elimination (T1/2 = 1.7 h for Dp44mT vs. 10.7 h for DpC) and lower exposure. Incubation of these compounds with cancer cells or cardiac myoblasts did not result in any significant metabolism in-vitro. The metabolism of Dp44mT in-vivo resulted in decreased anti-cancer activity and toxicity. In conclusion, marked differences in the pharmacology of Dp44mT and DpC were observed and highlight the favorable pharmacokinetics of DpC for cancer treatment.

Gemcitabine plus cisplatin vs. gemcitabine plus carboplatin in stage IIIb and IV non-small cell lung cancer: a phase III randomized trial.

PURPOSE: This randomized, multicenter, phase III trial was conducted to compare the tolerability of gemcitabine plus cisplatin (GP) vs. gemcitabine plus carboplatin (GC) in chemonaive patients with stage IIIb and IV non-small cell lung carcinoma (NSCLC). Secondary objectives were to evaluate response, duration of response, time to progressive disease (TTPD), and survival. PATIENTS AND METHODS: Eligible patients were required to have stage IIIb or IV NSCLC, no previous chemotherapy, Karnofsky performance status of at least 70, bidimensionally measurable disease, and age 18-75 years. Randomized patients in both arms were given gemcitabine 1200 mg/m(2) on days 1 and 8, followed on day 1 by cisplatin 80 mg/m(2) (GP) or carboplatin AUC=5 (GC). Treatment cycles were repeated every 21 days for a maximum of six cycles, or until disease progression or unacceptable toxicity occurred. RESULTS: Enrolled patients in both arms, 87 in GP and 89 in GC, were well balanced for demographics and disease characteristics. Dose intensity was 93.8 and 92.7% for gemcitabine in GP/GC arms, respectively; 97.7% for cisplatin and 99.9% for carboplatin. Patients with at least one grade 3/4 toxicity excluding nausea, vomiting or alopecia, were 44% in GP arm and 54% in GC arm. The only significantly different toxicities were, nausea and vomiting in GP and thrombocytopenia in GC group. The overall response rates, median TTPD, response duration and survival were, 41/29%, 5.87/4.75 months, 7.48/5.15 months, and 8.75/7.97 months for GP and GC arms, respectively. CONCLUSION: GP and GC are effective and feasible regimens for advanced NSCLC, and are comparable in efficacy and toxicity. GC may offer acceptable option to patients with advanced NSCLC, especially those who are unable to receive cisplatin.