ABSTRACT
Objective:To compare the dosimetric differences between the VenusX accelerator with an orthogonal dual-layer multi-leaf collimator (MLC) and the Varian′s CLINAC IX and EDGE accelerators with a single-layer MLC for hippocampus protection in the whole-brain radiotherapy (WBRT).Methods:Forty patients with multiple brain metastases admitted to the Radiotherapy Department of the Shanghai General Hospital from June 2021 to February 2023 were selected in this study. Three whole-brain treatment plans were designed based on the above three accelerators for each patient. Under the same prescription dose, radiation field, and plan constraints, the three plans were compared in terms of the dosimetric differences in target volumes, hippocampi, and adjacent organs at risk (OARs), as well as the execution efficiency.Results:For the planning target volume (PTV), there were statistically significant differences in approximate maximum dose ( D2) between the VenusX and IX plans ( t = 4.94, P < 0.05), in approximate minimum dose ( D98) between the VenusX and EDGE plans ( t = 5.98, P < 0.05), in the target conformity indices (CIs) between VenusX plan and EDGE plans, and between the VenusX and IX plans ( t = -6.84, -14.30; P < 0.05), and dose homogeneity indices (HIs) between the VenusX and IX plans ( t = 3.48, P < 0.05). For OARs, the maximum doses ( Dmax) and average doses ( Dmean) to bilateral hippocampi of the VenusX plan were lower than those of the EDGE and IX plans ( t = 8.59-17.11, P < 0.05); the maximum doses ( Dmax) to bilateral lenses, bilateral optic nerves, and optic chiasma of the VenusX plan were lower than those of the other two plans ( t = 2.10-20.80, P < 0.05); and the differences between the maximum doses ( Dmax) to the brain stem of the VenusX and EDGE plans were statistically significant ( t = 3.86, P < 0.05). In terms of plan execution efficiency, the number of machine jumps (MU) and the treatment time of the VenusX plan were higher than those of the EDGE and IX plans, with statistically significant differences ( t = -56.48, -56.90, P < 0.05). Conclusions:The doses to target volumes of the three treatment plans all meet the prescription requirements, and the VenusX plan outperforms the EDGE and IX plans in the protection of OARs. Despite the reduced execution efficiency, the VenusX plan shortens the actual treatment time by improving the dosage rate, thus meeting the clinical requirements.
ABSTRACT
@#<b>Objective</b> To compare the effects of different respiratory signal acquisition methods on the delineation of moving tumor targets. <b>Methods</b> A cube phantom containing a sphere was placed on a motion platform to simulate respiratory movement by setting motion period, frequency, and direction. Respiratory signal was acquired by real-time position management (RPM) method and GE method independently. Target delineation was conducted using the maximum intensity projection (MIP) sequence. The difference between the reconstructed volume and the theoretical moving volume was compared under the two respiratory signal acquisition methods for cube and sphere targets. <b>Results</b> Under the same respiratory signal acquisition method, the same respiratory amplitude, and different respiratory frequencies, reconstructed volume changes were relatively small. For the sphere target, the deviation between the reconstructed volume and the theoretical moving volume was −1.5% to 5.7% with the RPM method and −1.3% to −13.8% with the GE method (both <i>P</i> < 0.05). For the cube target, the deviation between the reconstructed volume and the theoretical moving volume was 0.2% to 0.9% with the RPM method and −2.6% to 0.9% with the GE method, with no statistical significance. <b>Conclusion</b> For small-volume sphere targets, the target volumes obtained from MIP images by the two respiratory signal acquisition methods are both smaller than the actual moving volume. For large-volume cube targets, there is no significant difference between the reconstructed and theoretical results with any respiratory signal acquisition method. The RPM method produces smaller deviation and better image quality when reconstructing small-volume targets.
ABSTRACT
AL3810, a molecular dual inhibitor of the vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), has earned the permission of phase II clinical trial for tumor treatment by China FDA. As a reversible ATP-competitive inhibitor, AL3810 targets ATP-binding site on intracellular region of VEGFR and FGFR, whereas, AL3810 lacking interplay with extracellular region of receptors rendered deficient blood-brain tumor barrier (BBTB) recognition, poor brain penetration and unsatisfactory anti-glioma efficacy. Integrin
ABSTRACT
Axonal transport of mitochondria is critical for neuronal survival and function. Automatically quantifying and analyzing mitochondrial movement in a large quantity remain challenging. Here, we report an efficient method for imaging and quantifying axonal mitochondrial transport using microfluidic-chamber-cultured neurons together with a newly developed analysis package named "MitoQuant". This tool-kit consists of an automated program for tracking mitochondrial movement inside live neuronal axons and a transient-velocity analysis program for analyzing dynamic movement patterns of mitochondria. Using this method, we examined axonal mitochondrial movement both in cultured mammalian neurons and in motor neuron axons of Drosophila in vivo. In 3 different paradigms (temperature changes, drug treatment and genetic manipulation) that affect mitochondria, we have shown that this new method is highly efficient and sensitive for detecting changes in mitochondrial movement. The method significantly enhanced our ability to quantitatively analyze axonal mitochondrial movement and allowed us to detect dynamic changes in axonal mitochondrial transport that were not detected by traditional kymographic analyses.