Effect of a Radiotherapeutic Megavoltage Beam on Ultrasound Contrast Agents

Collado-Lara, Gonzalo; Heymans, Sophie V.; Godart, J.; D’Agostino, Emiliano; D'hooge, Jan; Abeele, Koen Van Den; Vos, Hendrik J.; Jong, Nico de

doi:10.1016/j.ultrasmedbio.2021.02.021

Cited by 6 publications

(7 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The influence of radiation on commercial microbubbles was previously reported by Collado-Larra et al 29 Their study demonstrated that irradiating the ultrasound contrast agent SonoVue (known as Lumason in the United States) to >25 Gy, influenced its size distribution and acoustic response more than irradiated Definity. A decrease in the concentration of SonoVue bubbles with diameter < 7 μm was observed, while the acoustic scatter decreased by 3.5 dB after 24 Gy, and the acoustic attenuation increased by 0.15 dB/cm after 24 Gy.…”

Section: Resultsmentioning

confidence: 66%

“…However, Definity microbubbles did not exhibit a significant response to radiation. These findings indicate that both the components of the core and the microbubble shell might play a role in the bubbles' response to radiation 29 . In terms of PCCA, superheated PCCA of Freon 12 suspended within a wearable gel have been previously proposed as individual radiation detectors 27,30 .…”

Section: Resultsmentioning

confidence: 90%

“…These findings indicate that both the components of the core and the microbubble shell might play a role in the bubbles' response to radiation. 29 In terms of PCCA, superheated PCCA of Freon 12 suspended within a wearable gel have been previously proposed as individual radiation detectors. 27,30 This droplet activation exhibits a linear response of approximately 0.29 mSv/ hour.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Activation of Phase Change Contrast Agents Using Ionizing Radiation

Falatah

Lacerda

Chaga

et al. 2021

J of Ultrasound Medicine

View full text Add to dashboard Cite

The feasibility of activating phase change contrast agents (PCCA) made from Definity (Lantheus Medical Imaging) using X-rays was investigated. A 10 mL of Definity PCCA (0.1 mL PCCA/mL) were injected into gelatin phantoms and irradiated using doses of 0, 30, 50, and 100 Gy. Size distribution and PCCA activation were measured after irradiation. Definity PCCAs were activated at a threshold of 50 Gy. Changes were visible with microscopy, visual inspection of T-flasks, and ultrasound imaging of gelatin phantoms. Moreover, increasing the radiation dose above 50 Gy appeared to further activate PCCA. These results indicate Definity PCCAs may be useful for ultrasound-based radiation dosimetry.

show abstract

Section: Resultsmentioning

confidence: 66%

Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Activation of Phase Change Contrast Agents Using Ionizing Radiation

Falatah

Lacerda

Chaga

et al. 2021

J of Ultrasound Medicine

View full text Add to dashboard Cite

show abstract

“…For the proton irradiations, the one-dimensional histograms were compared to a verified model of the proton Bragg peak (Bortfeld 1997). In the verification process of this model, the proton depth dose distribution was measured with a multi-layer ionization chamber (QubeNext, DE.TEC.TOR, Turin, Italy) and fitted to an analytical model of the Bragg peak, as explained in Collado-Lara et al (2021, 2022. To evaluate the proton range after bubble localization, Gaussian curves were fitted through the middle of the histogram bins for each of the bubble localization methods.…”

Section: Bubblenet-network Performance Evaluationmentioning

confidence: 99%

Deep learning for dose assessment in radiotherapy by the super-localization of vaporized nanodroplets in high frame rate ultrasound imaging

Heyden¹,

Heymans²,

Carlier³

et al. 2022

Phys. Med. Biol.

Self Cite

View full text Add to dashboard Cite

Objective: External beam radiotherapy is aimed to precisely deliver a high radiation dose to malignancies, while optimally sparing surrounding healthy tissues. With the advent of increasingly complex treatment plans, the delivery should preferably be verified by Quality Assurance methods. Recently, online ultrasound imaging of vaporized radiosensitive nanodroplets was proposed as a promising tool for in vivo dosimetry in radiotherapy. Previously, the detection of sparse vaporization events was achieved by applying differential ultrasound (US) imaging followed by intensity thresholding using subjective parameter tuning, which is sensitive to image artifacts. Approach: A generalized deep learning solution (i.e., BubbleNet) is proposed to localize vaporized nanodroplets on differential US frames, while overcoming the aforementioned limitation. A 5-fold cross-validation was performed on a diversely composed 5747-frame training/validation dataset by manual segmentation. BubbleNet was then applied on a test dataset of 1536 differential US frames to evaluate dosimetric features. The intra-observer variability was determined by scoring the Dice Similarity Coefficient (DSC) on 150 frames segmented twice. Additionally, the BubbleNet generalization capability was tested on an external test dataset of 432 frames acquired by a phased array transducer at a much lower ultrasound frequency and reconstructed with unconventional pixel dimensions with respect to the training dataset. Main Results: The median DSC in the 5-fold cross validation was equal to ~0.88, which was in line with the intra-observer variability (=0.86). Next, BubbleNet was employed to detect vaporizations in differential US frames obtained during the irradiation of phantoms with a 154 MeV proton beam or a 6MV photon beam. BubbleNet improved the bubble-count statistics by ~30% compared to the earlier established intensity-weighted thresholding. The proton range was verified with a -0.8 mm accuracy. Significance: BubbleNet is a flexible tool to localize individual vaporized nanodroplets on experimentally acquired US images, which improves the sensitivity compared to former thresholding-weighted methods.

show abstract

“…Recently, applications requiring assessment of the frequency dependency of the attenuation coefficient of microbubbles in vivo have emerged, such as to relate changes in attenuation to external factors (as in e.g., radiation dosimetry [31,32]) or to a therapeutic payload release [33]. In addition, quantitative ultrasound applications often require real-time attenuation correction methods [34,35].…”

Section: Introductionmentioning

confidence: 99%

Single-shot attenuation coefficient estimation for ultrasound contrast agents

et al. 2022

Self Cite

View full text Add to dashboard Cite

Ultrasound contrast agents (UCAs) have broadened the scope of ultrasound imaging and therapeutic applications. One of the parameters of interest when measuring the response of UCAs to ultrasound is their frequency-dependent attenuation coefficient. The estimation of this parameter is relevant for sensing and therapeutic applications, as well as for obtaining the viscoelastic properties of the UCA’s shell. The current practice to obtain this coefficient relies on experimental measurements made both in the presence and absence of UCAs in a target medium. Not only is the microbubble-free reference measurement time-consuming, but it may also not always be feasible for in vivo applications due to lack of an appropriate reflector. To overcome these challenges, we present here a novel approach which estimates the UCA’s attenuation spectra directly from pulse-echo measurements made in the underlying UCA medium, without any reference measurement. Furthermore, despite the non-linear frequency dependency of the UCA’s attenuation profile, our approach can still benefit from a fast linear least-squares based estimation scheme, providing attenuation estimates in a single-shot, which is desirable for implementation in real-time systems. We provide an investigative study, testing the estimator’s performance on various simulated realistic attenuation profiles obtained by varying the shell parameters and the UCA’s size distribution. In all cases, the estimated attenuation profiles were in good agreement with the true ones, with a relative error < 10%. Evaluation on experimental in vitro data shows a relative error < 15%, which further highlights the potential of our approach for fast and accurate UCA’s attenuation estimation.

show abstract

Effect of a Radiotherapeutic Megavoltage Beam on Ultrasound Contrast Agents

Cited by 6 publications

References 48 publications

Activation of Phase Change Contrast Agents Using Ionizing Radiation

Activation of Phase Change Contrast Agents Using Ionizing Radiation

Deep learning for dose assessment in radiotherapy by the super-localization of vaporized nanodroplets in high frame rate ultrasound imaging

Single-shot attenuation coefficient estimation for ultrasound contrast agents

Contact Info

Product

Resources

About