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Endoscopic Cerenkov luminescence imaging and image-guided tumor resection on hepatocellular carcinoma-bearing mouse models
摘要： Detecting deep tumors inside living subject is still challenging for Cerenkov luminescence imaging (CLI). In this study, a high-sensitivity endoscopic CLI (ECLI) system was developed with a dual-mode deep cooling approach to improve the imaging sensitivity. System was characterized through a series of ex vivo studies. Furthermore, subcutaneous and orthotropic human hepatocellular carcinoma (HCC) mouse models were established for ECLI guided tumor resection in vivo. The results showed that the ECLI system had spatial resolution (62.5 μm) and imaging sensitivity (6.29×10-2 kBq/μl 18F-FDG). While the results from both subcutaneous and orthotropic HCC mouse models demonstrate the effectiveness of the system to intraoperatively guide the surgery of deep tumors such as liver cancer. Overall, the developed system exhibits promising potential for the applications of tumor precise resection and novel nanoprobe based optical imaging.
关键词： Endoscopy,Image-guided surgery,Hepatocellular carcinoma (HCC),Cerenkov luminescence imaging
更新于2025-09-23 15:22:29
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Pumping Systems for Compton Free-Electron Lasers: Microwave Undulators and Powering Sources
摘要： The concept of Compton-type free-electron lasers (FELs) operating in short wavelength ranges with a high e?ciency and power level is currently underway at the IAP RAS (Nizhny Novgorod). This concept is aimed at reducing the energy of a driving relativistic electron beam and thereby increasing the e?ciency of the electron–wave interaction in FELs, as well as making the oscillator relatively compact. The basis of this concept is microwave undulators of a new type — the so-called “?ying” undulators. This paper is devoted to the results of the current studies of these undulators, their simulation, and “cold” electrodynamic tests in the Ka band. For powering microwave undulators, a spatially extended narrow-band ˇCerenkov surface-wave oscillators (SWOs) are developed in the speci?ed frequency range driven by Sinus-6, a high-current accelerator, with a particle energy of 0.5 MeV, a current of 5 kA, and a pulse duration of 25 ns. The required sub-gigawatt power level of output radiation combined with a high stability of the narrow-band oscillation regime is achieved under conditions of a strongly oversized oscillator by using two-dimensional distributed feedback provided in a 2D doubly-periodic slow-wave structure. The design parameters of a 32 GHz/0.5 GW SWO intended for powering microwave undulators are presented and the results of its simulation and reported.
关键词： flying undulators,Ka band,Cerenkov surface-wave oscillators,Sinus-6 accelerator,microwave undulators,Compton-type free-electron lasers
更新于2025-09-23 15:21:01
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Optical external efficiency of terahertz quantum cascade laser based on ??erenkov difference frequency generation
摘要： In this paper, we consider terahertz sources based on ?erenkov di?erence frequency generation in a dual-wavelength mid-infrared quantum cascade laser and calculate analytically the optical external e±ciency of the out-going terahertz wave. The mid-infrared pumps operate simultaneously and have a common upper level. For short cavity lengths and low terahertz losses in the substrate, we ˉnd that implementation of the ?erenkov emission scheme in terahertz di?erence frequency generation quantum cascade lasers improves the optical external e±ciency dramatically. The maximum value of the latter is close to 19%, but is only attainable if the laser exhibits negligible mid-infrared transmission losses.
关键词： phased matching,Terahertz quantum cascade laser,optical external e±ciency,?erenkov,di?erence frequency generation
更新于2025-09-23 15:19:57
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Osteotropic Radiolabeled Nanophotosensitizer for Imaging and Treating Multiple Myeloma
摘要： Rapid liver and spleen opsonization of systemically administered nanoparticles (NPs) for in vivo applications remains the Achilles’ heel of nanomedicine, allowing only a small fraction of the materials to reach the intended target tissue. Although focusing on diseases that reside in the natural disposal organs for nanoparticles is a viable option, it limits the plurality of lesions that could bene?t from nanomedical interventions. Here we designed a theranostic nanoplatform consisting of reactive oxygen (ROS)-generating titanium dioxide (TiO2) NPs, coated with a tumor-targeting agent, transferrin (Tf), and radiolabeled with a radionuclide (89Zr) for targeting bone marrow, imaging the distribution of the NPs, and stimulating ROS generation for cell killing. Radiolabeling of TiO2 NPs with 89Zr a?orded thermodynamically and kinetically stable chelate-free 89Zr-TiO2-Tf NPs without altering the NP morphology. Treatment of multiple myeloma (MM) cells, a disease of plasma cells originating in the bone marrow, with 89Zr-TiO2-Tf generated cytotoxic ROS to induce cancer cell killing via the apoptosis pathway. Positron emission tomography/X-ray computed tomography (PET/CT) imaging and tissue biodistribution studies revealed that in vivo administration of 89Zr-TiO2-Tf in mice leveraged the osteotropic e?ect of 89Zr to selectively localize about 70% of the injected radioactivity in mouse bone tissue. A combination of small-animal PET/CT imaging of NP distribution and bioluminescence imaging of cancer progression showed that a single-dose 89Zr-TiO2-Tf treatment in a disseminated MM mouse model completely inhibited cancer growth at euthanasia of untreated mice and at least doubled the survival of treated mice. Treatment of the mice with cold Zr-TiO2-Tf, 89Zr-oxalate, or 89Zr-Tf had no therapeutic bene?t compared to untreated controls. This study reveals an e?ective radionuclide sensitizing nanophototherapy paradigm for the treatment of MM and possibly other bone-associated malignancies.
关键词： multiple myeloma,cancer,Zr-89,nanoparticles,Cerenkov radiation
更新于2025-09-19 17:13:59
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Cerenkov Luminescence-Induced NO Release from 32P-Labeled ZnFe(CN)5NO Nanosheets to Enhance Radioisotope-Immunotherapy
摘要： The combination of radiotherapy with immunotherapy has emerged as a promising combinational therapeutic methodology. The efficacies of both types of therapies, however, are hampered by the abnormal tumor microenvironment (TME) with hypoxic and immunosuppressive features. Herein, we discover that by mixing zinc ions with sodium nitroprusside, a clinical anti-hypertensive drug, ZnFe(CN)5NO single-layer nanosheets can be obtained. Interestingly, after being labeled with 32P by simple mixing, the 32P-induced Cerenkov luminescence stimulated persistent release of NO from nanosheets. Owing to the modulation of hypoxic immunosuppressive TME by NO, such 32P-labeled nanosheets are able to completely eliminate local tumors after local administration, and proffer a strong abscopal effect after being combined with immune-checkpoint blockade therapy. Our work presents a unique 2D nanoplatform comprising Zn2+ and a clinical drug to enable chelator-free radiolabeling, Cerenkov luminescence-triggered NO release, effective TME modulation, and enhanced combination radioisotope-immunotherapy are promising for tumor metastasis treatment.
关键词： radioisotope-immunotherapy,ZnFe(CN)5NO nanosheets,Cerenkov luminescence,tumor microenvironment,NO release
更新于2025-09-12 10:27:22
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Cherenkov imaging for linac beam shape analysis as a remote electronic quality assessment verification tool
摘要： Purpose: A remote imaging system tracking Cherenkov emission was analyzed to verify that the linear accelerator (linac) beam shape could be quantitatively measured at the irradiation surface for Quality Audit (QA). Methods: The Cherenkov camera recorded 2D dose images delivered on a solid acrylonitrile butadiene styrene (ABS) plastic phantom surface for a range of square beam sizes, and 6 MV photons. Imaging was done at source to surface distance (SSD) of 100cm and compared to GaF film images and linac light fields of the same beam sizes, ranging over 5×5cm2 up to 20×20cm2. Line profiles of each field were compared in both X and Y jaw directions. Each measurement was repeated on 2 different Clinac2100 machines. An inter-reader comparison of the beam width interpretation was completed using procedures commonly employed for beam to light field coincidence verification. Cherenkov measurements are also done for beams of complex treatment plan and isocenter QA. Results: The Cherenkov image widths matched with the measured GaF images and light field images, with accuracy in the range of +/-1mm standard deviation. The differences between the measurements were minor and within tolerance of geometrical requirement of standard linac QA procedures conducted by human set up verification, which had a similar error range. The measurement made by the remote imaging system allowed for beam shape extraction of radiation fields at the SSD location of the beam. Conclusions: The proposed Cherenkov image acquisition system provides a valid way to remotely confirm radiation field sizes and provides similar information to that obtained from the linac light field or GaF film estimates of the beam size. The major benefit of this approach is that with a fixed installation of the camera, testing could be done completely under software control with automated image analysis, potentially simplifying conventional QA procedures with appropriate calibration of boundary definitions, and the natural extension to capturing dynamic treatment beamlets at SSD could have future value, such as verification of beam plans with complex beam shapes, like IMRT or “star-shot” QA for the isocenter.
关键词： linear accelerator,light field,dosimetry,QA,radiotherapy,Cerenkov
更新于2025-09-10 09:29:36