Significance

X-ray-induced acoustic computed tomography (XACT) offers a promising approach to biomedical imaging, leveraging X-ray absorption contrast. It overcomes the shortages of traditional X-ray, allowing for more advanced medical imaging.

Aim

The review focuses on the significance and draws onto the potential applications of XACT to demonstrate it as an innovative imaging technique.

Approach

This review navigates the expanding landscape of XACT imaging within the biomedical sphere. Integral topics addressed encompass the refinement of imaging systems and the advancement in image reconstruction algorithms. The review particularly emphasizes XACT's significant biomedical applications.

Results

Key uses, such as breast imaging, bone density maps for osteoporosis, and X-ray molecular imaging, are highlighted to demonstrate the capability of XACT. A unique niche for XACT imaging is its application in in vivo dosimetry during radiotherapy, which has been validated on patients.

Conclusions

Because of its unique property, XACT has great potential in biomedicine and non-destructive testing. We conclude by casting light on potential future avenues in this promising domain.

Resistance to ionizing radiation (IR), which is a conventional treatment for osteosarcoma that cannot be resected, undermines the efficacy of this therapy. However, the mechanism by which IR induces radioresistance in osteosarcoma is not defined. Here, we report that CR6-interacting factor-1 (CRIF1) is highly expressed in osteosarcoma and undergoes nuclear-cytoplasmic shuttling of cyclin-dependent kinase 2 (CDK2) after IR. Osteosarcoma cells lacking CRIF1 show increased sensitivity to IR, which is associated with delayed DNA damage repair, inactivated G1/S checkpoint, and mitochondrial dysfunction. CRIF1 interacts with the DNA damage checkpoint regulator CDK2, and CRIF1 and CDK2 colocalize in the nucleus after IR. Nuclear localization of CDK2 is associated with phosphorylation changes that promote DNA repair and activation of the G1/S checkpoint. CRIF1 knockdown synergized with IR in an in vivo osteosarcoma model, leading to tumor regression. Based on these findings, we identify CRIF1 as a potential therapeutic target in osteosarcoma that can increase the efficacy of radiotherapy. More broadly, our findings may provide insights into the mechanism for other types of radioresistant cancers and be exploited for therapeutic ends.