Result of Space Particle Monitor (SPM) on-Orbit Demonstration

Space Particle Monitor (SPM) is a compact, lightweight and low-cost radiation measurement device that applies two PIN silicon semiconductor detectors. SPM was developed in the SERVIS (Space Environment Reliability Verification Integrated System) project under the Ministry of Economy, Trade and Industry (METI), and is mounted on JAXA RAPid Innovative payload demonstration Satellite 1 (RAPIS-1) launched in January 2019. We achieved the full success that the discrimination and energy content of electrons, protons, and heavy ions could be observed. This paper reports on-orbit demonstration results of SPM

Tolerability and Efficacy of Neoadjuvant Chemotherapy with a Tri-Weekly Interval Methotrexate, Doxorubicin, Vinblastine, and Cisplatin Regimen for Patients with Locally Advanced Bladder Cancer

Objective: Compared with standard treatment, a modified tri-weekly MVAC (methotrexate, doxorubicin, vinblastine, and cisplatin) treatment regimen with a high cisplatin dose intensity shows good efficacy and lower toxicity. Thus, we retrospectively investigated the tolerability and efficacy of a modified tri-weekly MVAC neoadjuvant regimen. Methods: We analyzed 25 patients with locally advanced bladder cancer medicated by a modified tri-weekly MVAC neoadjuvant regimen that omits treatment on days 15 and 22. The efficacy and tolerability were assessed retrospectively. Results: The numbers of patients in clinical stages 2, 3, and 4 were 13 (52.0%), 1 (4.0%), and 11 (44.0%), respectively. Surgery could be performed on all patients. Five patients (20.0%) had no cancer remaining in their surgical specimens. Remaining non-muscle-invasive cancer without metastasis was observed in 7 patients (28.0%), and the total downstaging rate was 44.0%. The 5-year overall and relapse-free survival rates were 79.0 and 75.0%, respectively. The overall relative dose intensity was 0.90. Serious hematologic toxicities rated grade 3 or greater were leukopenia in 6 patients (24.0%) and anemia in 1 patient (4.0%). Conclusions: Sufficient efficacy and tolerability of a modified tri-weekly MVAC neoadjuvant regimen were suggested. Thus, tri-weekly modified MVAC may be an option for neoadjuvant chemotherapy of advanced bladder cancer

Performance of a Characteristic X-ray Camera to Identify Contamination of Radioactive Cesium

The lightweight, high sensitivity and low-price camera to image Cs-137 contamination in environment has been developed. These three merits have not been realized by recent gamma cameras and Compton cameras. The camera images Cs-137 distribution by detecting the characteristic X-rays from it instead of gamma-rays. We have investigated the performance of the characteristic X-ray camera (CXRC) in detail and the specification is summarized

Characteristic X-ray detector with a large sensitive area: Its sensitivity to environmental radioactive cesium and imaging performance as confirmed in an area of Fukushima

An X-ray detector which we call the characteristic X-ray detector (CXRD) with a large sensitive area of 199 cm2 was studied as a candidate imaging device with high sensitivity, light weight and low-cost features to visualize environmental 137Cs deposited after the Fukushima Dai-ichi Nuclear Power Station accident. The CXRD has a directionality for its sensitivity and it is able to visualize a spatial distribution of 137Cs by scanning the flux of 32 keV characteristic X-rays due to disintegration of 137Cs instead of imaging the 662 keV gamma-rays from 137Cs. Our experimental results showed that the counting efficiency of the CXRD was 105 counts per second for a 1 MBq 137Cs source at a distance of 1m and the CXRD had a very high counting efficiency for a certain direction. We estimated the potential sensitivity of the CXRD when it was used in the scanning mode to image an area of 2π sr. The CXRD was tested in a contaminated forest in Fukushima Prefecture and images of the spatial distribution of 137Cs in the forest were successfully obtained. We found that most of the 137Cs was present in the forest floor and no 137Cs was detected in the atmosphere and the tree canopy. The CXRD is useful because of its low cost, light weight and high sensitivity as a 137Cs imaging device for monitoring post devices in forests and as a portable imaging device to confirm the effectiveness of decontamination work