Many mobile systems need to achieve both high performance and low memory usage, and the total performance of such the systems can be largely affected by the effectiveness of GC. Hence, the recent ...popularization of mobile devices makes the GC performance play one of the important roles on the wide range of platforms. The response performance degradation caused by suspending all processes for GC has been a well-known potential problem. Therefore, GC algorithms have been actively studied and improved, but they still have not reached any fundamental solution. In this paper, we focus on the point that the same objects are redundantly marked during the GC procedure implemented on DalvikVM, which is one of the famous runtime environments for the mobile devices. Then we propose a hardware support technique for improving marking routine of GC. We installed a set of tables to a processor for managing marked objects, and redundant marking for marked objects can be omitted by referring these tables. The result of the simulation experiment shows that the percentage of redundant marking is reduced by more than 50%.
A combined system comprising the TrueBeam linear accelerator and a new real‐time, tumor‐tracking radiotherapy system, SyncTraX, was installed in our institution. The goals of this study were to ...assess the capability of SyncTraX in measuring the position of a fiducial marker using color fluoroscopic images, and to evaluate the dosimetric and geometric accuracy of respiratory‐gated radiotherapy using this combined system for the simple geometry. For the fundamental evaluation of respiratory‐gated radiotherapy using SyncTraX, the following were performed: 1) determination of dosimetric and positional characteristics of sinusoidal patterns using a motor‐driven base for several gating windows; 2) measurement of time delay using an oscilloscope; 3) positional verification of sinusoidal patterns and the pattern in the case of a lung cancer patient; 4) measurement of the half‐value layer (HVL in mm AL), effective kVp, and air kerma, using a solid‐state detector for each fluoroscopic condition, to determine the patient dose. The dose profile in a moving phantom with gated radiotherapy having a gating window ≤4 mm was in good agreement with that under static conditions for each photon beam. The total time delay between TrueBeam and SyncTraX was <227 ms for each photon beam. The mean of the positional tracking error was <0.4 mm for sinusoidal patterns and for the pattern in the case of a lung cancer patient. The air‐kerma rates from one fluoroscopy direction were 1.93±0.01, 2.86±0.01, 3.92±0.04, 5.28±0.03, and 6.60±0.05 mGy/min for 70, 80, 90, 100, and 110 kV X‐ray beams at 80 mA, respectively. The combined system comprising TrueBeam and SyncTraX could track the motion of the fiducial marker and control radiation delivery with reasonable accuracy; therefore, this system provides significant dosimetric improvement. However, patient exposure dose from fluoroscopy was not clinically negligible.
PACS number(s): 87.53.Bn, 87.55.km, 87.55.Qr
The artery of Davidoff and Schechter (ADS) is mostly identified in pathological conditions such as dural arteriovenous fistulas and brain tumors. Herein, we report a rare case of a ruptured aneurysm ...of the ADS, which was one of the feeders of a falcotentorial dural arteriovenous fistula. We performed endovascular embolization of the aneurysm and parent artery using n-butyl-2-cyanoacrylate. Complete occlusion of the fistula was achieved by another feeder after the acute phase. To our best knowledge, only a few reports on embolization of ruptured ADS aneurysms exist. Furthermore, this is the first report on the embolization of a ruptured ADS aneurysm using n-butyl-2-cyanoacrylate. This case highlights that endovascular n-butyl-2-cyanoacrylate embolization could be a useful treatment for a ruptured ADS aneurysm.
To quantify dose delivery errors for high-dose-rate image-guided brachytherapy (HDR-IGBT) using an independent end-to-end dose delivery quality assurance test at multiple institutions. The novelty of ...our study is that this is the first multi-institutional end-to-end dose delivery study in the world.
The postal audit used a polymer gel dosimeter in a cylindrical acrylic container for the afterloading system. Image acquisition using computed tomography, treatment planning, and irradiation were performed at each institution. Dose distribution comparison between the plan and gel measurement was performed. The percentage of pixels satisfying the absolute-dose gamma criterion was reviewed.
Thirty-five institutions participated in this study. The dose uncertainty was 3.6% ± 2.3% (mean ± 1.96σ). The geometric uncertainty with a coverage factor of k = 2 was 3.5 mm. The tolerance level was set to the gamma passing rate of 95% with the agreement criterion of 5% (global)/3 mm, which was determined from the uncertainty estimation. The percentage of pixels satisfying the gamma criterion was 90.4% ± 32.2% (mean ± 1.96σ). Sixty-six percent (23/35) of the institutions passed the verification. Of the institutions that failed the verification, 75% (9/12) had incorrect inputs of the offset between the catheter tip and indexer length in treatment planning and 17% (2/12) had incorrect catheter reconstruction in treatment planning.
The methodology should be useful for comprehensively checking the accuracy of HDR-IGBT dose delivery and credentialing clinical studies. The results of our study highlight the high risk of large source positional errors while delivering dose for HDR-IGBT in clinical practices.
In high-precision radiotherapy, absolute and relative doses are evaluated for patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA). In our institution, we use ...GAFCHROMIC EBT3 (EBT3) for relative dose evaluation in IMRT QA. We usually use two directional film configurations, which are in the axial and sagittal planes. The QA in our institution shows some differences between the gamma pass rates in the axial and sagittal directions. The purpose of this study was to evaluate the incident directional dependence of EBT3 by using the percent depth dose (PDD) and the off-center ratio (OCR) between EBT3 films positioned perpendicular to the beam axis and along the beam axis. Furthermore, we compared the PDD in EBT3 films positioned perpendicular to the beam axis and the PDD by using an ionization chamber. In addition, PDDs in water phantoms with and without EBT3 films were calculated by Monte Carlo simulation. The results showed that the PDD in EBT3 films positioned perpendicular to the beam axis increased with the depth from the phantom surface. Monte Carlo simulation showed the same trend as did the film measurements. The OCR results were slightly different at dose levels below 20 %. The OCR in EBT3 films positioned along the beam axis was higher than that perpendicular to the beam axis. Thus, we conclude that EBT3 film has incident directional dependence. In IMRT QA, the gamma analysis results may be affected by the incident directional dependence of EBT3 film.
The aim of this study is to describe a phantom designed for independent examination of a source position in brachytherapy that is suitable for inclusion in an external auditing program.
We developed ...a phantom that has a special design and a simple mechanism, capable of firmly fixing a radiochromic film and tandem-ovoid applicators to assess discrepancies in source positions between the measurements and treatment planning system (TPS). Three tests were conducted: 1) reproducibility of the source positions (
= 5); 2) source movements inside the applicator tube; 3) changing source position by changing curvature of the transfer tubes. In addition, as a trial study, the phantom was mailed to 12 institutions, and 23 trial data sets were examined. The source displacement ΔX and ΔY (reference = TPS) were expressed according to the coordinates, in which the positive direction on the X-axis corresponds to the external side of the applicator perpendicular to source transfer direction Y-axis.
Test 1: The 1σ fell within 1 mm irrespective of the dwell positions. Test 2: ΔX were greater around the tip of the applicator owing to the source cable. Test 3: All of the source position changes fell within 1 mm. For postal audit, the mean and 1.96σ in ΔX were 0.8 and 0.8 mm, respectively. Almost all data were located within a positive region along the X-axis due to the source cable. The mean and 1.96σ in ΔY were 0.3 and 1.6 mm, respectively. The variance in ΔY was greater than that in ΔX, and large uncertainties exist in the determination of the first dwell position. The 95% confidence limit was 2.1 mm.
In HDR brachytherapy, an effectiveness of independent source position assessment could be demonstrated. The 95% confidence limit was 2.1 mm for a tandem-ovoids applicator.
Here we report that simultaneous inhibition of the three primary DNA damage recognition PI3 kinase-like kinases (PIKKs) —ATM, ATR, and DNA-PK— induces severe combinatorial synthetic lethality in ...mammalian cells. Utilizing Chinese hamster cell lines CHO and V79 and their respective PIKK mutants, we evaluated effects of inhibiting these three kinases on cell viability, DNA damage response, and chromosomal integrity. Our results demonstrate that while single or dual kinase inhibition increased cytotoxicity, inhibition of all three PIKKs results in significantly higher synergistic lethality, chromosomal aberrations, and DNA double-strand break (DSB) induction as calculated by their synergy scores. These findings suggest that the overlapping redundancy of ATM, ATR, and DNA-PK functions is critical for cell survival, and their combined inhibition greatly disrupts DNA damage signaling and repair processes, leading to cell death. This study provides insights into the potential of multi-targeted DDR kinase inhibition as an effective anticancer strategy, necessitating further research to elucidate underlying mechanisms and therapeutic applications.
•Simultaneous inhibition of ATM, ATR, and DNA-PK induces synergistic lethality stronger than dual inhibitions of any of them.•Cellular lethality is associated with chromosome aberration induction rather than SCE.•This study suggests that overlapping redundancy of ATM, ATR, and DNA-PK functions in DNA damage responses.
Left ventricular assist devices (LVADs) are an epoch-making treatment option for patients with severe heart failure; however, the patients occasionally experience severe acute ischemic strokes ...(AISs). Although mechanical thrombectomy is considered as an effective treatment for severe AIS in patients with LVADs, there remains a paucity of data on the long-term outcomes. This study aimed to investigate the acute-phase efficacy and long-term outcomes of mechanical thrombectomy for AIS patients with LVADs.
We retrospectively reviewed 9 cases in 8 patients with LVADs who developed AIS and underwent mechanical thrombectomy from July 2014 to November 2021 at our hospital. Clinical information, including the National Institutes of Health Stroke Scale score and modified Rankin Scale score before and after thrombectomy, the details of procedures, and the long-term outcomes after thrombectomy, was retrospectively reviewed and statistically analyzed.
Effective recanalization was achieved in 89% of the 9 cases. The median National Institutes of Health Stroke Scale score improved from 12 (range, 8-29) to 5 (range, 0-29) after mechanical thrombectomy. The median total follow-up duration was 1327 (range, 78-2659) days. Of the 8 patients, 3 patients underwent heart transplantation, and the LVAD was removed after recovery of the patient's heart function. One patient awaited heart transplantation.
This study revealed the long-term benefit of mechanical thrombectomy for AIS in patients with LVADs, eventually achieving 50% of independence from LVADs.
Purpose
Leptomeningeal metastasis (LM) is a complication of surgery for brain metastasis and is a risk factor of poor prognosis. The risk of LM is particularly high after surgery for a breast cancer ...metastasis to the brain. If the risk of LM after surgical resection for a brain metastasis were predictable, appropriate adjuvant therapy could be administered to individual patients to improve their prognosis. The present study aimed to reveal the genetic characteristics of brain metastases as means of predicting LM in breast cancer patients.
Methods
Ten patients with brain metastases of breast cancer presented LM after surgical resection were analyzed by whole-exome sequencing.
Results
A
chromodomain-helicase-DNA-binding protein 5 (CHD5)
gene alteration was detected in nine cases (90%), including a nonsynonymous variant in four cases and copy number deletion in five cases. CHD5 protein expression was lost in nine cases and had decreased in one case. The frequency of
CHD5
gene alteration in brain metastases with LM was significantly higher than in primary breast cancer (2.3%) or in brain metastases of breast cancer (0%) (p < 0.0001).
Conclusions
These results suggested that the
CHD5
gene alteration was associated with LM after surgical resection of breast cancer brain metastases. Searching for the gene alteration might predict the LM risk after surgical resection.
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