Photoacoustic imaging and photoacoustic spectrum analysis in mouse models of cutaneous squamous cell carcinoma / 中华皮肤科杂志

ABSTRACT

Objective To establish a photoacoustic detection system and data processing methods for skin tumors,and to explore photoacoustic imaging and photoacoustic spectrum in mouse models of cutaneous squamous cell carcinoma (CSCC).Methods A total of 60 healthy specific pathogen-free (SPF) female BALB/C nude mice aged 6-8 weeks were randomly and equally divided into 2 groups to be inoculated with a murine CSCC cell line XL50 and a human CSCC cell line A431 respectively on the right back near the upper limbs,and mouse models of murine CSCC (n =20) and human CSCC (n =20) were successfully established.The 850-nm photoacoustic detection system was applied in the above 2 kinds of mouse models,and photoacoustic imaging and photoacoustic spectrum data were collected.The fitted slope of acoustic power spectrum curves was compared between squamous cell carcinoma tissues and normal skin on the left back of the mouse model.After the photoacoustic detection,tumor tissues and normal skin at the opposite side were excised from the 2 kinds of mouse models,and subjected to histopathological examination.The fitted slope of different tissues was compared by using t test.Results Photoacoustic imaging showed higher photoacoustic signals of hemoglobin in squamous cell carcinoma tissues compared with the normal skin tissues.In the model of murine CSCC,the fitted slope of acoustic power spectrum curve was significantly lower in the tumor tissues (-1.827 ± 0.153 1) than in the normal skin tissues (-1.059 ± 0.117 8,t =3.973,P ＜ 0.001).In the model of human CSCC,the fitted slope of acoustic power spectrum curve was also significantly lower in the tumor tissues (-1.537 ± 0.125 5) than in the normal skin tissues (-0.960 ± 0.259 7,t =2.166,P =0.043).Histopathological examination showed that the number of vessels increased in the tumor tissues compared with the normal skin tissues.Conclusion CSCC tissues are different from normal skin tissues in photoacoustic imaging signals and the fitted slope of acoustic power spectrum,which may lay a foundation for non-invasive photoacoustic diagnosis of CSCC.