Recent Posts

A comparative study of plasmonic nanoparticles for targeted photothermal therapy of melanoma tumors using various irradiation modes

Author(s): Lidia Mikhailova, Elizaveta Vysotina, Maria Timofeeva, Elena Kopoleva, Van Gulinyan, Olesia Pashina, Konstantin Arabuli, Olga Gusliakova, Ekaterina Prikhozhdenko, Xiaoli Qi, Andrey Petrov, Eduard Ageev, Mihail Petrov, Constantino De Angelis, Mikhail Durymanov, Gleb Sukhorukov, Mikhail V. ZyuzinLidia Mikhailova, Elizaveta Vysotina, Maria Timofeeva, Elena Kopoleva, Van Gulinyan, Olesia Pashina, Konstantin Arabuli, Olga Gusliakova, Ekaterina Prikhozhdenko, Xiaoli Qi, Andrey Petrov, Eduard Ageev, Mihail Petrov, Constantino De Angelis, Mikhail Durymanov, Gleb Sukhorukov, Mikhail V. Zyuzin
ABSTRACT

Melanoma, a highly malignant and complex form of cancer, has increased in global incidence, with a growing number of new cases annually. Active targeting strategies, such as leveraging the α-melanocyte-stimulating hormone (αMSH) and its interaction with the melanocortin 1 receptor (MC1R) overexpressed in melanoma cells, enhance the concentration of therapeutic agents at tumor sites. For instance, targeted delivery of plasmonic light-sensitive agents and precise hyperthermia management provide an effective, minimally invasive treatment for tumors. In this work, we present a comparative study on targeted photothermal therapy (PTT) using plasmonic gold nanorods (Au NRs) as a robust and safe nanotool to reveal how key treatment parameters affect therapy outcomes. Using an animal model (B16-F10) of melanoma tumors, we compare the targeting abilities of Au NRs modified with two different MC1R agonists, either closely mimicking the αMSH sequence or providing a superior functionalization extent of Au NRs (4.5% (w/w) versus 1.8% (w/w)), revealing 1.6 times better intratumoral localization. Following theoretical and experimental assessments of the heating capabilities of the developed Au NRs under laser irradiation in either the femtosecond (FS)- or nanosecond (NS)- pulsed regime, we perform targeted PTT employing two types of peptide-modified Au NRs and compare therapeutic outcomes revealing the most appropriate PTT conditions. Our investigation reveals greater heat release from Au NRs under irradiation with FS laser, due to the relaxation rates of the electron and phonon temperatures dissipating in the surrounding, which correlates with a more pronounced 17.6 times inhibition of tumor growth when using FS-pulsed regime.

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Rotational ultrasound and photoacoustic tomography of the human body

Author(s): Yang Zhang, Shuai Na, Jonathan J. Russin, Karteekeya Sastry, Li Lin, Junfu Zheng, Yilin Luo, Xin Tong, Yujin An, Peng Hu, Konstantin Maslov, Tze-Woei Tan, Charles Y. Liu, Lihong V. Wang

ABSTRACT

Imaging the human body’s morphological and angiographic information is essential for diagnosing, monitoring, and treating medical conditions. Ultrasonography performs the morphological assessment of the soft tissue based on acoustic impedance variations, whereas photoacoustic tomography (PAT) can visualize blood vessels based on intrinsic hemoglobin absorption. Three-dimensional (3D) panoramic imaging of the vasculature is generally not practical in conventional ultrasonography with limited field-of-view (FOV) probes, and PAT does not provide sufficient scattering-based soft tissue morphological contrast. Complementing each other, fast panoramic rotational ultrasound tomography (RUST) and PAT are integrated for hybrid rotational ultrasound and photoacoustic tomography (RUS-PAT), which obtains 3D ultrasound structural and PAT angiographic images of the human body quasi-simultaneously. The RUST functionality is achieved in a cost-effective manner using a single-element ultrasonic transducer for ultrasound transmission and rotating arc-shaped arrays for 3D panoramic detection. RUST is superior to conventional ultrasonography, which either has a limited FOV with a linear array or is high-cost with a hemispherical array that requires both transmission and receiving. By switching the acoustic source to a light source, the system is conveniently converted to PAT mode to acquire angiographic images in the same region. Using RUS-PAT, we have successfully imaged the human head, breast, hand, and foot with a 10 cm diameter FOV, submillimeter isotropic resolution, and 10 s imaging time for each modality. The 3D RUS-PAT is a powerful tool for high-speed, 3D, dual-contrast imaging of the human body with potential for rapid clinical translation.

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3D protoacoustic radiography: A proof of principle study

Author(s): Prabodh K Pandey, Gilberto Gonzalez, Kristina Bjegovic, Leshan Sun, Yong Chen, Liangzhong Xiang

ABSTRACT

We propose protoacoustic radiography (PAR), an imaging modality combining proton excitation and acoustic detection for three-dimensional (3D) imaging from a single proton projection. PAR avoids the effect of multiple Coulomb scattering in imaging by detecting ultrasound. Proton-induced acoustic waves propagate spherically, enabling 3D imaging from a single projection. Additionally, the distinctive feature of proton beams—concentrating energy deposition primarily at the Bragg peak—allows for precise depth-selectivity through proton energy tuning. We performed PAR using clinical proton machines, and our results demonstrate the capability of PAR to reconstruct targets at various depths (between ∼20 and 23 cm) with an axial resolution of 1.3 mm by fully leveraging the Bragg peak and by tuning the kinetic energy of the proton beam. PAR offers opportunities for precise structural determination with protons both in biomedicine and nondestructive testing.

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Ionizing radiation acoustic and ultrasound dual-modality imaging for visualization of dose on anatomical structures during radiotherapy

Author(s): Yaocai Huang, Ibrahim Oraiqat, Dale Litzenberg, Madhumithra Subramanian Karthikes, Christopher Tichacek, Glebys Gonzalez, Zhanpeng Xu, Sarah Dykstra, Borui Li, Scott Hadley, Eduardo G. Moros, Man Zhang, Paul L. Carson, Kyle C. Cuneo, Xueding Wang, Issam El Naqa, Wei Zhang
ABSTRACT

The aim of this study is to visualize the radiation dose on anatomical structures during radiation therapy (RT) by mapping radiation dose deposition and tracking anatomical structures simultaneously. A dual-modality volumetric imaging system, which combines ionizing radiation acoustic imaging (iRAI) and ultrasound (US) imaging, was developed to provide dose deposition and anatomical information in real-time during RT. The performance of the proposed system was first evaluated via experiments on tissue-mimicking phantoms driven by a custom motion stage. By using US imaging to correct the position of anatomical structures, the dose mapping accuracy of the system increased by up to 0.51 in structural similarity index measure (SSIM) and 74.60 % in Gamma passing rate (GPR) compared to standalone iRAI. A subsequent study on a rabbit model in vivo further confirmed the capability of the system in mapping of the radiation dose deposition in the target tissue as well as its change caused by the motion mainly due to the animal breath. These findings demonstrate that this first-of-its-kind dual-modality volumetric imaging system can provide volumetric dose-on-anatomy information during RT. After further validation in clinic, this technique holds potential for enhancing RT outcomes by ensuring accurate alignment between the planned radiation beams, the target, and surrounding organs at risk.

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PHOTOSOUND TECHNOLOGIES, INC. ANNOUNCES PARNTERSHIP WITH VERASONICS

Partnership to Offer Vantage® Customers Expanded Capabilities in Applications Including Use with Photoacoustic Imaging, Thermoacoustic Imaging and Monitoring Radiation Therapy

Houston, TX, June 24, 2025 – PhotoSound® Technologies, Inc., today announced a partnership with Verasonics, Inc. the leader in research ultrasound to offer customers the PhotoSound Legion™ AMP for use with Vantage® and Vantage NXT Research Ultrasound Systems. Partnership will offer Vantage customers expanded capabilities by integrating the Legion AMP in applications using photoacoustic imaging, thermoacoustic imaging, and monitoring radiation therapy, among others.


The Legion AMP is a 128-channel receive signal preamplifier for use with Vantage or Vantage NXT Research Ultrasound Systems, in all channel configurations. It features high input impedance and a fixed 40db gain that amplifies weak signals especially in the lower frequency band with a high Signal to Noise Ratio (SNR). This is especially useful for research and development applications where a pulsed energy source is used where the excitation source is either weak or a long pulse.


“Adding a Legion AMP unit to a Vantage or Vantage NXT platform allows researchers to refine their receive capabilities, ensuring they are capturing key data,” said Jon K. Daigle, President and Chief Executive Officer at Verasonics. “This partnership will allow us to better serve our mutual customer base.”
“In thermo-, photo-, and optoacoustic imaging, lower frequency signals are often underrepresented because many systems don’t respond to them evenly. The Legion Amp maintains a consistent high SNR response across a broad frequency range, including below 100 kHz, which helps preserve the true shape and strength of the original signal,” said Peter Brecht CEO of PhotoSound Technologies. “I’m excited about this new collaboration and believe it will result in interesting new discoveries.”

Learn more, visit https://www.photosound.com/home/products/data-acquisition/legion-amp/

About Verasonics, Inc.

Verasonics is a privately held company founded in 2001, with headquarters in Kirkland, Washington, USA. Verasonics, the leader in research ultrasound, is focused on providing researchers and developers with the most advanced and flexible tools enabling them to develop new algorithms and products used in biomedical ultrasound, materials science, earth sciences, and the physics of acoustics and ultrasonics. Verasonics also licenses its technology to companies for use in their commercial products. Researchers in countries across North and South America, Europe, Asia and Oceania routinely use Verasonics product solutions to advance the art and science of ultrasound through their own research efforts.

Learn more by visiting the Verasonics website or following us on LinkedIn and X(Formerly Twitter).

Media Contact:

Verasonics, Inc. Toni Baumann
T: 425-242-7506
E: [email protected]

TriTom System Featured on Lithuanian National TV

We’re proud to share that PhotoSound Technologies’ TriTom™ system was recently featured on Lithuanian national television. The broadcast segment highlighted innovations in medical imaging, beginning with our laser partner EKSPLA (14:20), followed by the TriTom system (14:55), and continuing with other leaders in photoacoustic imaging, including PA Imaging (19:15) and iThera Medical (21:30).

Watch the full segment here

Topics covered include medical innovation, cancer detection, and advances in ultrasound and photoacoustic technologies.

4D IN VIVO DOSIMETRY FOR A FLASH ELECTRON BEAM USING RADIATION-INDUCED ACOUSTIC IMAGING

Authors: Kristina Bjegovic, Leshan Sun, Prabodh Pandey, Veljko Grilj, Paola Ballesteros-Zebadua, Ryan Paisley, Gilberto Gonzalez, Siqi Wang, Marie Catherine Vozenin, Charles L Limoli and Shawn (Liangzhong) Xiang

ABSTRACT

Objective. The primary goal of this research is to demonstrate the feasibility of radiation-induced acoustic imaging (RAI) as a volumetric dosimetry tool for ultra-high dose rate FLASH electron radiotherapy (FLASH-RT) in real time. This technology aims to improve patient outcomes by accurate measurements of in vivo dose delivery to target tumor volumes.

Approach. The study utilized the FLASH-capable eRT6 LINAC to deliver electron beams under various doses (1.2 Gy pulse−1 to 4.95 Gy pulse−1) and instantaneous dose rates (1.55 × 105 Gy s−1 to 2.75 × 106 Gy s−1), for imaging the beam in water and in a rabbit cadaver with RAI. A custom 256-element matrix ultrasound array was employed for real-time, volumetric (4D) imaging of individual pulses. This allowed for the exploration of dose linearity by varying the dose per pulse and analyzing the results through signal processing and image reconstruction in RAI.

Main Results. By varying the dose per pulse through changes in source-to-surface distance, a direct correlation was established between the peak-to-peak amplitudes of pressure waves captured by the RAI system and the radiochromic film dose measurements. This correlation demonstrated dose rate linearity, including in the FLASH regime, without any saturation even at an instantaneous dose rate up to 2.75 × 106 Gy s−1. Further, the use of the 2D matrix array enabled 4D tracking of FLASH electron beam dose distributions on animal tissue for the first time.

Significance. This research successfully shows that 4D in vivo dosimetry is feasible during FLASH-RT using a RAI system. It allows for precise spatial (∼mm) and temporal (25 frames s−1) monitoring of individual FLASH beamlets during delivery. This advancement is crucial for the clinical translation of FLASH-RT as enhancing the accuracy of dose delivery to the target volume the safety and efficacy of radiotherapeutic procedures will be improved.

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TOWARD REAL-TIME, VOLUMETRIC DOSIMETRY FOR FLASH-CAPABLE CLINICAL SYNCHROCYCLOTRONS USING PROTOACOUSTIC IMAGING

Authors: Siqi Wang, Gilberto Gonzalez, Daniel Rocky Owen, Leshan Sun, Yan Liu, Townsend Zwart, Yong Chen, Liangzhong Xiang

ABSTRACT

Background
Radiation delivery with ultra-high dose rate (FLASH) radiotherapy (RT) holds promise for improving treatment outcomes and reducing side effects but poses challenges in radiation delivery accuracy due to its ultra-high dose rates. This necessitates the development of novel imaging and verification technologies tailored to these conditions.

Purpose
Our study explores the effectiveness of proton-induced acoustic imaging (PAI) in tracking the Bragg peak in three dimensions and in real time during FLASH proton irradiations, offering a method for volumetric beam imaging at both conventional and FLASH dose rates.

Methods
We developed a three-dimensional (3D) PAI technique using a 256-element ultrasound detector array for FLASH dose rate proton beams. In the study, we tested protoacoustic signal with a beamline of a FLASH-capable synchrocyclotron, setting the distal 90% of the Bragg peak around 35 mm away from the ultrasound array. This configuration allowed us to assess various total proton radiation doses, maintaining a consistent beam output of 21 pC/pulse. We also explored a spectrum of dose rates, from 15 Gy/s up to a FLASH rate of 48 Gy/s, by administering a set number of pulses. Furthermore, we implemented a three-dot scanning beam approach to observe the distinct movements of individual Bragg peaks using PAI. All these procedures utilized a proton beam energy of 180 MeV to achieve the maximum possible dose rate.

Results
Our findings indicate a strong linear relationship between protoacoustic signal amplitudes and delivered doses (R2 = 0.9997), with a consistent fit across different dose rates. The technique successfully provided 3D renderings of Bragg peaks at FLASH rates, validated through absolute Gamma index values.

Conclusions
The protoacoustic system demonstrates effectiveness in 3D visualization and tracking of the Bragg peak during FLASH proton therapy, representing a notable advancement in proton therapy quality assurance. This method promises enhancements in protoacoustic image guidance and real-time dosimetry, paving the way for more accurate and effective treatments in ultra-high dose rate therapy environments.

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REAL-TIME TRACKING OF THE BRAGG PEAK DURING PROTON THERAPY VIA 3D PROTOACOUSTIC IMAGING IN A CLINICAL SCENARIO

Authors: Siqi Wang, Gilberto Gonzalez, Leshan Sun, Yifei Xu, Prabodh Pandey, Yong Chen & Shawn (Liangzhong) Xiang

Fig. 5
ABSTRACT

Proton radiotherapy favored over X-ray photon therapy due to its reduced radiation exposure to surrounding healthy tissues, is highly dependent on the accurate positioning of the Bragg peak. Existing methods like PET and prompt gamma imaging to localize Bragg peak face challenges of low precision and high complexity. Here we introduce a 3D protoacoustic imaging with a 2D matrix array of 256 ultrasound transducers compatible with 256 parallel data acquisition channels provides real-time imaging capability (up to 75 frames per second with 10 averages), achieving high precision (5 mm/5% Gamma index shows accuracy better than 95.73%) at depths of tens of centimeters. We have successfully implemented this method in liver treatment with 5 pencil beam scanning and in prostate cancer treatment on a human torso phantom using a clinical proton machine. This demonstrates its capability to accurately identify the Bragg peak in practical clinical scenarios. It paves the way for adaptive radiotherapy with real-time feedback, potentially revolutionizing radiotherapy by enabling closed-loop treatment for improved patient outcomes.

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