Application And Significance Of Optical Coherence Tomography In Vulvar Lichen Sclerosus

Vulvar lichen sclerosus(VLS)is a nonneoplastic lesion occurring in the skin and mucosa of female genitals,belonging to a subtype of hypopigmented vulvar disease.The main symptom of the VLS is pruritus of vulva,and the main signs of VLS are thinning of the vulva and perianal skin and hypopigmentation of the skin.In the later stage,it may progress to vulva atrophy,adhesion and scar formation,resulting in genital deformity,even dysuria and dyssexual intercourse,which seriously endanger the physical and mental health of women.According to epidemiological investigation,the incidence of vulvar lichen sclerosus varies from 0.1%to 1.7%.Due to the different clinical manifestations of VLS,no obvious clinical symptoms even in the early stage,unclear diagnosis by clinicians,or patients did not seek medical advice,the incidence of VLS is far higher than the reported incidence.The disease can occur at any age,but it is more common in women aged 40,secondly in young girls.The malignant transformation rate is 2%-5%and increases with age.Therefore,early detection,diagnosis and treatment can effectively reduce the incidence of VLS progressing to vulvar squamous cellcarcinoma.At present,conventional gynecological examination is more commonly used in clinical diagnosis of VLS,which is only used for preliminary screening.But it is impossible to accurately judge the nature of lesions only by visual observation.Histopathological biopsy is the "golden standard" for the diagnosis of VLS,but there is still a possibility of missed diagnosis.Histopathological biopsy is invasive examination,which brings significant pain to the patient,and may also cause local infection and scar,and the result takes a long time and costs a lot.Colposcope,which observes skin changes and vascular morphology of the lesion through magnification,combined with vinegar and white test is conducive to the identification of vulvar precancerous lesions and vulvar cancer.Single point or multi-point biopsy of vulva tissue under colposcopy is helpful to improve the detection rate and reduce the rate of missed diagnosis.Optical coherence tomography(OCT)is an emerging method for disease screening and diagnosis.OCT uses the principles of near-infrared and optical interference to scan human tissue to reconstruct a three-dimensional image of the internal structure of biological tissue.OCT is used for real-time,in vivo and high-resolution imagingdiagnosis of tissues.In the field of biology and medicine,OCT is known as "optical biopsy".The imaging quality of the microstructure of biological tissues is close to or reaches the level of histopathology,so that clinicians can more intuitively understand the changes of tissue microstructure.And it provides scientific reference basis for the diagnosis and treatment of diseases.At the same time,as a navigation tool,OCT can guide clinicians to choose the best biopsy site in some parts which must be biopsied.Therefore,it can increase the positive rate of the biopsy.At present,the application of OCT in the diagnosis of VLS is not supported by clinical data.In this study,OCT is used to perform in-vivo and high-resolution imaging of in vivo vulvar skin tissue to help understand the pathological changes of VLS and analyze the clinical application value of OCT in VLS.ObjectiveIn this study,through OCT scanning of patients' vulva skin tissues,the image characteristics of OCT in normal vulva and vulvar lichen sclerosus were summarized,so as to guide clinicians to choose the best biopsy site,make up for the deficiency of existing examination,and laythe foundation for the application of OCT in other vulva diseases in the future.Material and methods1 Object of studyFrom June 2018 to September 2019,63 patients from the third affiliated hospital of zhengzhou university who underwent colposcopy,OCT scanning and pathological biopsy of vulva due to vulva lesions were recruited for the study.According to the routine histopathological results,the 63 patients could be divided into two groups:15 patients in the normal vulva group(including 15 biopsies)and 48 patients in the VLS group(including 72 biopsies).2 MethodsAll the patients were examined by OCT scanning and colposcopy in turn,then biopsies of suspected lesions were taken under colposcopy for routine pathological examination.The image characteristics of OCT in normal vulva and vulvar lichen sclerosus were summarized by comparing OCT scan images with HE images of conventional histological slides.With the results of conventional histopathological as the gold standard,three researchers conducted a blind test of OCT scanning image classification to analyze the consistency of the three diagnostic results,so as to study the application value of OCT technology in vulvar lichen sclerosus.Results1.There was no statistical significance in age,pregnancy and average course of disease between the VLS group and the normal vulva group(P>0.05).2.The normal epidermal thickness of vulva was(93.60±5.99)?m,while the epidermal thickness of VLS was(62.42±10.42)?m,P<0.05.Distinctive patterns for normal vulvar tissues and vulval lichen sclerosus were clearly observed from OCT images,which matched well with corresponding histological slides.3.OCT images demonstrated a sensitivity of 90.28%(95%confidence interval,CI,86.30%-94.26%)and a specificity of 62.22%(95%CI,47.49%-76.95%)for detecting vulval lichen sclerosus when blindly tested by three investigators.A substantial inter-observer agreement was observed(?=0.736),which showed high diagnostic consistency among three investigators.ConclusionsOCT images can be used to provide more precise information of the content and extent of suspicious sites,which would be useful for guiding colposcopy-directed biopsies.