window chamber surgery in tumor cell injected mice for tumor growth visualization and imaging

Inoculazione guidata del tumore e imaging multimodale nei topi

Tumor microvasculature is an important component of the tumor microenvironment that can be a target for therapy and a determinant of treatment response. In the preclinical setting, the microvasculature is typically studied using intravital microscopy in orthotopic or heterotopic window chamber animal models1,2. This has several advantages over histological studies since the imaging is done in live tissues and the tumor can be monitored longitudinally over several weeks or even months2,3. These studies can leverage the high-resolution imaging capabilities of intravital microscopy to study the delivery of therapeutics to the tumor4,5, the causes of treatment resistance6, and the response of the micro vessels to therapies such as antiangiogenic treatment7,8 and radiotherapy2,9.
Intravital microscopy clearly plays an important role in preclinical cancer research; however, how can tumor microenvironmental features be measured in the clinic? Microvascular information would be useful in the clinic for measuring blood supply and tumor cell hypoxia, which is important for determining treatment resistance in radiotherapy10, as well as the ability of the microvasculature to deliver chemotherapeutic agents to the surrounding tumor cells11. For example, in radiotherapy, spatial information on the structure and function of the tumor microvasculature may help personalize a patient&#39;s treatment plan by adjusting the fractionation schedule or by preferentially boosting the dose to avascular and likely hypoxic regions12.
Intravital microscopy can measure these important microvascular features since it has a very high resolution (&#956;m scale); however, its depth penetration into tissue is limited to several hundred microns or a few millimeters, at most making clinical implementation challenging. Indeed, there are some novel applications of intravital microscopy in the clinic13; however, these are still limited to examinations of near-surface level tissue such as the skin14 or mucosal/endothelial linings of various body cavities via flexible catheters/endoscopes15,16.
More commonly, the microvasculature is studied using imaging modalities such as CT17 or MRI18. These clinical imaging modalities can image to any depth within the body, but they have a much lower spatial resolution (mm scale). Thus, there is a need to bridge this resolution gap between preclinical intravital microscopy and clinical imaging modalities to bring high-resolution and detailed microvascular information into the clinic19. Several functional imaging methods have been developed to improve the microvascular imaging capabilities of clinical imaging modalities such as dynamic contrast-enhanced (DCE) MRI and CT20, and Intravoxel incoherent motion (IVIM) MRI21. However, these are model-based methods that provide indirect measurements of the microvasculature and thus, must be validated with appropriate &#34;ground truth&#34; measurements of the microvasculature19,22.
We have developed a dorsal skinfold window chamber (DSFC) tumor mouse model to bridge this gap between preclinical intravital microscopy and clinically applicable imaging modalities such as CT and MRI. The DSFC provides direct access to the tumor for high-resolution, intravital microscopy imaging through a glass window but also clinically applicable imaging such as MRI as it is made of MR-compatible materials (plastic and glass). Furthermore, an included MATLAB code performs multimodality 3D co-registration for direct spatial correlations between preclinical intravital microscopy and clinically applicable imaging modalities. Here we will describe the design and surgery to install the DSFC as well as the procedure to co-register intravital microscopy and clinically applicable imaging modalities.

Autore in primo piano: Integrazione dell'imaging intravitale ad alta risoluzione e della risonanza magnetica per migliorare la pianificazione della radioterapia stereotassica corporea

Un modello murino tumorale della camera della finestra delle pliche cutanee dorsali per la microscopia intravitale combinata e la risonanza magnetica nella ricerca traslazionale sul cancro

Preclinical intravital imaging has very high resolution, but limited depth penetration in the tissue, which makes it very good for preclinical imaging studies. On the other hand, MRI is much more clinically applicable and has a higher depth penetration, but very low spatial resolution. The goal of this study is to correlate these two modalities with each other in order to better translate our findings from preclinical intravital microscopy into the clinic via magnetic resonance imaging.Perfusion-sensitive imaging methods in MRI and biophotonics, including our optical coherence tomography and geography system, are revealing how the microvasculature impacts tumor response to hypofractionated radiotherapy. 3D printing is also aiding through cost-effective custom tool manufacturing, facilitating longitudinal studies. Finally, AI image analysis is facilitating the identification of novel radiotherapy predictive biomarkers.We've made several findings concerning the tumor response to hypofractionated radiotherapy, including more recently, the temporal kinetics of both radiobiologically significant and abstracted AI-derived tissue response metrics. Additionally, we have demonstrated the promise for multimodal imaging being performed more accurately, correlating both MRI, macroscopic and optical coherence tomography, microscopic, angiography-derived metrics. By extending the effective length of longitudinal studies, we may better identify predictive biomarkers for long-term tumor treatment response.Additionally, by improving robustness of co-registration between macroscopic clinically available imaging modalities and microscopic preclinical imaging modalities, we may enhance the translatability of our findings from benchtop to bedside. During a stereotactic body radiation therapy, high doses of radiation are delivering a reduced number of fractions. One potential radiobiological target associated with increased cell death in SVRT is the tumor microvasculature.By combining high-resolution optical angiography and MRI, we want to enable functional MRI microvascular imaging for patient-specific SVRT treatment planning and improved outcomes.

Chirurgia della camera a finestra in topi iniettati con cellule tumorali per la visualizzazione e l'imaging della crescita tumorale

Per iniziare, sterilizzare le parti della camera della finestra principale con un disinfettante liquido di alto livello per 12 minuti. Seguito da immersione in alcol isopropilico per cinque minuti. Somministrare un milligrammo per chilogrammo di buprenorfina a rilascio prolungato al topo iniettato con cellule tumorali da una a tre ore prima dell'intervento chirurgico.Per la disinfezione, strofinare il topo anestetizzato e rasato con una soluzione di iodio povidone al 7,5%. Pulire lo scrub disinfettante con alcol isopropilico al 70%. Applicare una soluzione di iodio povidone al 10% sulla pelle.Infine, applicare un lubrificante veterinario per gli occhi per prevenire la secchezza. Solleva la pelle del topo lungo la colonna vertebrale e individua il tumore che cresce su una delle pieghe cutanee laterali. Posizionare il telaio posteriore della camera della finestra della plica cutanea dorsale, o DSFC, in modo che il tumore sia centrato all'interno del telaio.Aggiungere tre punti di sutura ai tre fori superiori del DSFC e alla guida chirurgica per fissare la posizione del telaio posteriore. Inserire tre aghi attraverso il telaio posteriore del DSFC nei fori contenenti i distanziatori. Utilizzando un pennarello chirurgico, segnare sulla pelle tre punti per i distanziatori del telaio posteriore DSFC.Disegna un cerchio di un centimetro di diametro per indicare l'area della pelle da rimuovere. Dopo aver segnato altri tre punti, tagliare i punti di sutura per rimuovere gli aghi e il telaio posteriore. Rimuovere la pelle dal cerchio segnato utilizzando le micro forbici chirurgiche.Quindi posizionare la sutura temporanea per fissare le parti della camera della finestra alla pelle. Stringere il gruppo con una sutura temporanea e inserire il telaio anteriore sotto la pelle attraverso il foro. Posizionare suture permanenti attraverso i fori attorno al perimetro dei telai anteriore e posteriore del DSFC.Dopo aver rimosso la sutura temporanea, fissare la clip di supporto al telaio posteriore del DSFC. Somministrare cinque milligrammi di meloxicam per chilogrammo di peso corporeo per via sottocutanea al topo per ridurre il dolore e l'infiammazione.

window-chamber-surgery-tumor-cell-injected-mice-for-tumor-growth

Research

JoVE Journal

Cancer Research

Window Chamber Surgery in Tumor Cell Injected Mice for Tumor Growth Visualization and Imaging

A Dorsal Skinfold Window Chamber Tumor Mouse Model for Combined Intravital Microscopy and Magnetic Resonance Imaging in Translational Cancer Research

Preclinical intravital imaging such as microscopy and optical coherence tomography have proven to be valuable tools in cancer research for visualizing the ...

Ricerca

Ricerca sul cancro

Tumor Cells Inoculation in Mice Through Precise Landmarking and Injection Techniques

Inoculazione di cellule tumorali nei topi attraverso tecniche di landmarking e iniezione precise

Integrative Imaging Techniques for Tumor Analysis in Mice

Tecniche di imaging integrative per l'analisi dei tumori nei topi