Clinical and Translational Imaging最新文献

Surgery is a key treatment for localized or locally advanced solid tumors. However, the application of wide safety margins can result in significant side effects and functional limitations for the patient. On the contrary, tissue-sparing surgery may leave residual tumor, which can lead to local recurrent cancer or distant metastases. To address these problems, intraoperative radio-guidance, such as beta radio-guided surgery (RGS), could be used to detect small cancerous tissue and selectively resect malignant areas. This paper provides a comprehensive review of RGS based on beta emission, focusing on the physical principles that differentiate beta radiation from gamma radiation, which is already commonly used in nuclear medicine. Although beta RGS was proposed several decades ago, its popularity has recently increased, possibly due to the widespread use of newly developed PET radiotracers. Various approaches are currently being investigated to assess the effectiveness of beta RGS, including the use of both beta+ and beta− emitting radiopharmaceuticals. Beta RGS has unique characteristics that make it a promising complementary technique to standard procedures. Encouraging results have been obtained in numerous ex vivo and in vivo tests. However, clinical trials are needed to demonstrate the real clinical value of these promising technologies. The references presented represent the most impactful works in the development of beta RGS, according to the authors. Papers were selected from a Scopus search with keywords “radio-guided surgery” and “beta emitter”.

Objective

Review, qualify and synthesize the evidence that compared computed tomography (CT) images with magnetic resonance imaging (MRI) in detecting multiple myeloma (MM) lesions in the skull, through a systematic review.

Methods

Searches were performed in six databases and the grey literature, up to August 2023, without restriction by date or publication language. Observational studies comparing CT images and MRI of the skull of patients previously diagnosed with MM were included. Data were extracted by two reviewers in a standardized and independent manner. The methodological quality assessment was performed using the QUADAS-2 tool and the evidence certainty assessment using the GRADE tool.

Results

Of the 911 identified references, 11 were included, and they all used either positron emission computed tomography (PET/CT) and/or low-dose computed tomography (LDCT) to compare to MRI. In 6 of 7 studies, MRI demonstrated a greater capacity to detect MM lesions than PET/CT images. When compared with LDCT images, MRI showed lower detection capacity in 4 studies. Six of the 11 included articles had a low risk of bias. However, as observational data evidence, the assessed certainty of the evidence was considered very low.

Conclusions

PET/CT and MRI images presented limitations in detecting MM lesions in the skull compared to LDCT images. The evidence suggested that the greatest detection capability could be achieved by employing whole-body MRI complemented by LDCT images of the skull. Future studies are needed to confirm this result.

Purpose

This study explored the feasibility of ⁶⁸gallium (Ga)-labeled novel fibroblast activation protein (FAP)-targeted ligand for tumor imaging through small-animal PET/CT (positron emission computed tomography/computed tomography).

Methods

The FAP-ligand (FL) was created by adding the chelating group dodecane tetraacetic acid (DOTA) and labeling with ⁶⁸Ga. The MC38 cell line was used to establish a C57BL/6 mice colon cancer model. The radioactivity distribution of labeled ⁶⁸Ga-DOTA-FL across various organs of the mouse model was examined ex-vivo. In addition, ⁶⁸Ga-DOTA-FL tumor-targeted imaging in vivo was performed using small-animal PET/CT. Finally, western blotting and immunofluorescence imaging of MC38 cells and xenotransplant tumor tissues were conducted.

Results

The radiolabeling rate and radiochemical purity of ⁶⁸Ga-DOTA-FL were above 95%. Both western blotting and immunofluorescence imaging revealed FAP expression in the tumor tissues, but not in the MC38 cells. Small-animal PET/CT imaging indicated that the tumor imaging was clearest at 30 min after ⁶⁸Ga-DOTA-FL treatment. Examination of the radioactivity distribution in vitro revealed that at 30 min after the ⁶⁸Ga-DOTA-FL treatment, the target/non-target ratio for tumor and muscle tissue was 4.0 ± 0.3 (n = 3).

Conclusions

⁶⁸Ga-DOTA-FL can be used for the specific tumor imaging in mouse models, which might provide a novel alternative for FAP-targeted tumor imaging.