Suzaku Detection of Extended/Diffuse Hard X-Ray Emission from the Galactic Center

Five on-plane regions within +/- 0.8deg of the Galactic center were observed with the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS) onboard Suzaku. From all regions, significant hard X-ray emission was detected with HXD-PIN up to 40 keV, in addition to the extended plasma emission which is dominant in the XIS band. The hard X-ray signals are inferred to come primarily from a spatially extended source, rather than from a small number of bright discrete objects. Contributions to the HXD data from catalogued X-ray sources, typically brighter than 1 mCrab, were estimated and removed using information from Suzaku and other satellites. Even after this removal, the hard X-ray signals remained significant, exhibiting a typical 12--40 keV surface brightness of 4E-10 erg cm-2 s-1 deg-2 and power-law-like spectra with a photon index of 1.8. Combined fittings to the XIS and HXD-PIN spectra confirm that a separate hard tail component is superposed onto the hot thermal emission, confirming a previous report based on the XIS data. Over the 5--40 keV band, the hard tail is spectrally approximated by a power law of photon index ~2, but better by those with somewhat convex shapes. Possible origins of the extended hard X-ray emission are discussed.Comment: 13 pages, 18 figure

Clinical outcomes in elderly patients administered gefitinib as first-line treatment in epidermal growth factor receptor-mutated non-small-cell lung cancer: retrospective analysis in a Nagano Lung Cancer Research Group Study

信州大学博士（医学）・学位論文・平成24年3月31日授与（甲第939号）・立石 一成The final publication is available at www.springerlink.com.The clinical efficacy and outcomes of gefitinib therapy as a first-line treatment for elderly patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations were analyzed retrospectively. We analyzed chemotherapy-naive NSCLC patients aged 75 years or older who had EGFR mutations (exon 19 deletion mutation or L858R), who were initially treated with gefitinib (250 mg) once daily in Nagano Prefecture. A total of 55 patients (16 men, 39 women) with a median age of 81.1 years (range; 75-94 years) treated between April 2007 and July 2012 were analyzed. The overall response rate and disease control rate were 72.7 % (95 % confidence interval (CI); 59.5-82.9 %) and 92.7 % (95 % CI; 82.0-97.6 %), respectively. Median progression-free survival and overall survival from the start of gefitinib treatment were 13.8 months (95 % CI; 9.9-18.8 months) and 29.1 months (95 % CI; 22.4 months-not reached), respectively. Two-year survival rate was 59.5 % (95 % CI; 41.0-78.0 %). Major grade 3 toxicities were skin rash (1.8 %) and increased levels of aspartate aminotransferase or alanine aminotransferase (7.3 %). First-line treatment with gefitinib for elderly EGFR-mutated NSCLC patients was effective and well tolerated. The results suggest that first-line gefitinib should be considered as a preferable standard treatment in elderly patients with advanced NSCLC harboring EGFR mutations.ArticleMEDICAL ONCOLOGY. 30(1):45 (2013)journal articl