Multi-center clinical study using optical coherence tomography for evaluation of cervical lesions in-vivo

Characteristics and utility of high-resolution optical coherence microscopy images of endocervical canal lesions

OBJECTIVES

To investigate optical coherence microscopy (OCM) imaging features and the application value of these high-resolution images for identifying endocervical canal lesions (ECLs), which is a clinical dilemma in cervical cancer screening programs.

METHODS

In total, 520 OCM images were obtained by scanning the cervical canal lesions with an ultra-high-resolution OCM system (204 specimens from 73 patients). The OCM morphologic characteristics of ECLs were observed and summarized, and then 3 researchers performed a diagnostic test of OCM images of cervical canal lesions. The accuracy, sensitivity, specificity, positive predictive value, negative predictive value, 95% confidence interval of each parameter, and interinvestigator agreement (κ) were calculated.

RESULTS

Normal endocervix, cysts, squamous metaplasia, high-grade squamous intraepithelial lesions involving glands, and invasive carcinoma had distinct OCM characteristics, which correlated well with corresponding H&E histologic sections. The accuracy, sensitivity, and specificity of the 3 researchers were 90.6%, 89.3% (95% CI, 86.5%-91.7%) and 91.6% (95% CI, 89.2%-93.5%), respectively. The positive predictive value was 90.1% (95% CI, 87.3%-92.4%), and the negative predictive value was 90.9% (95% CI, 88.5%-92.9%), with almost perfect agreement (κ = 0.874).

CONCLUSIONS

The application of the OCM system in cervical canal lesions is feasible and could help improve detection of occult ECLs in cervical cancer screening programs. This study lays the foundation for further research on OCM in cervical canal lesions in vivo, which also has a potential impact on projecting pathologic evaluation beyond what is currently possible, perhaps globally.

Handheld vital microscopy for the identification of microcirculatory alterations in cervical intraepithelial neoplasia and cervical cancer

BACKGROUND

Ninety percent of cervical cancer (CC) diagnoses and deaths occur in low and middle-income countries (LMICs). Especially in these countries, where human and material resources are limited, there is a need for real-time screening methods that enable immediate treatment decisions (i.e., 'see and treat').

OBJECTIVE

To evaluate whether handheld vital microscopy (HVM) enables real-time detection of microvascular alterations associated with cervical intraepithelial neoplasia (CIN) and CC.

METHODS

A cross-sectional study was conducted in an oncologic hospital and outpatient clinic, and included ten healthy controls, ten women with CIN, and ten women with CC. The microvasculature was assessed in four quadrants of the uterine cervix using HVM. The primary outcome was the presence of abnormal angioarchitecture (AA). Secondary outcomes included capillary loop density (CD), total vessel density (TVD), functional capillary density (FCD), and the proportion of perfused vessels (PPV).

RESULTS

198 image sequences of the cervical microvasculature were recorded. Compared to healthy controls, significantly more abnormal image sequences were observed in women with high-grade CIN (11 % vs. 44 %, P < 0.001) and women with CC (11 % vs. 69 %, P < 0.001). TVD, FCD, and PPV were lower in women with CIN and CC.

CONCLUSIONS

HVM enables easy, real-time, non-invasive assessment of cervical lesions through the detection of microvascular alterations. Thereby, HVM potentially provides an opportunity for point-of-care screening, which may enable immediate treatment decisions (see and treat) and reduce the number of unnecessary surgical interventions.

Optical Coherence Tomography Can Reduce Colposcopic Referral Rates in Patients With High-Risk Human Papillomavirus

OBJECTIVE

This study aimed to evaluate the feasibility of combined human papillomavirus (HPV) and optical coherence tomography (OCT) cervical cancer screening strategies.

MATERIALS AND METHODS

The OCT and cytology results were compared with the pathological results to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and immediate cervical intraepithelial neoplasia grade 3 or worse (CIN3+) risk. The authors compared the efficiency of colposcopy by using different triage strategies. They discussed differentiation in OCT screening in different age groups.

RESULTS

Eight hundred thirteen participants with high-risk HPV-positive and cervical cytology results underwent OCT before colposcopy between March 1 and October 1, 2021. The HPV16/18 genotyping with OCT triage has a specificity of CIN3+ lesions (61.1%; 95% CI = 57.6%-64.6%), intraepithelial neoplasia grade 2 or worse (CIN2+) (66.0%; 95% CI = 62.4%-69.6%). The HPV16/18 genotyping with cytology triage has a specificity of CIN3+ (44.0%; 95% CI = 40.4%-47.6%), CIN2+ (47.0%; 95% CI = 43.2%-50.8%). The OCT triage has a higher positive predictive value compared with the cytology, with a significant difference in CIN2+ lesions (45.0%; 95% CI = 38.8%-51.3% vs 29.2%; 95% CI = 24.7%-33.7%).

CONCLUSIONS

The combination of OCT and high-risk HPV triage (both genotyping and nongenotyping) had a similar immediate CIN3+ risk stratification and reduced the number of colposcopies compared with the cytological triage strategy.

Cross-Attention Based Multi-Resolution Feature Fusion Model for Self-Supervised Cervical OCT Image Classification

Cervical cancer seriously endangers the health of the female reproductive system and even risks women's life in severe cases. Optical coherence tomography (OCT) is a non-invasive, real-time, high-resolution imaging technology for cervical tissues. However, since the interpretation of cervical OCT images is a knowledge-intensive, time-consuming task, it is tough to acquire a large number of high-quality labeled images quickly, which is a big challenge for supervised learning. In this study, we introduce the vision Transformer (ViT) architecture, which has recently achieved impressive results in natural image analysis, into the classification task of cervical OCT images. Our work aims to develop a computer-aided diagnosis (CADx) approach based on a self-supervised ViT-based model to classify cervical OCT images effectively. We leverage masked autoencoders (MAE) to perform self-supervised pre-training on cervical OCT images, so the proposed classification model has a better transfer learning ability. In the fine-tuning process, the ViT-based classification model extracts multi-scale features from OCT images of different resolutions and fuses them with the cross-attention module. The ten-fold cross-validation results on an OCT image dataset from a multi-center clinical study of 733 patients in China indicate that our model achieved an AUC value of 0.9963 ± 0.0069 with a 95.89 ± 3.30% sensitivity and 98.23 ± 1.36 % specificity, outperforming some state-of-the-art classification models based on Transformers and convolutional neural networks (CNNs) in the binary classification task of detecting high-risk cervical diseases, including high-grade squamous intraepithelial lesion (HSIL) and cervical cancer. Furthermore, our model with the cross-shaped voting strategy achieved a sensitivity of 92.06% and specificity of 95.56% on an external validation dataset containing 288 three-dimensional (3D) OCT volumes from 118 Chinese patients in a different new hospital. This result met or exceeded the average of four medical experts who have used OCT for over one year. In addition to promising classification performance, our model has a remarkable ability to detect and visualize local lesions using the attention map of the standard ViT model, providing good interpretability for gynecologists to locate and diagnose possible cervical diseases.

Study on the application of optical coherence microscopy in Hirschsprung's disease

To explore the clinical application value of optical coherence microscopy (OCM) in Hirschsprung's disease. 109 HSCR patients were recuited in a Chinese hospital from January 2018 to July 2021. All the recruited patients underwent barium enema angiography preoperatively and the resected diseased intestinal tubes were evaluated intraoperatively. The OCM and the histopathological examination were performed successively on the surgical specimens, and the OCM images were compared with the relevant tissue sections to characterize different lesions. 10 non-HSCR fetal colorectal tissues at the same period were retained for OCM, the characteristics of which with and without HSCR under OCM imaging were analyzed. In the OCM images of in vitro tissue, it can be clearly observed that the scattering degree of HSCR narrow segment mucosal is high, glands and crypt structures are reduced or even atrophy, and the scattering degree of submucosal and intermuscular is low; In the dilated segment, the low scattering and high scattering are complex, and the muscle layer is obviously hypertrophy and structural disorder. Compared with the pathological findings, the OCM sensitivity, Kappa value, and AUC area reached 92.66%, 0.63, and 0.91, respectively. OCM can quickly and clearly display the structure of all layers of colorectal tissue, which is highly consistent with the corresponding histopathological examination results and has high sensitivity. which will provide a more reliable basis for OCM diagnosis of early HSCR, targeted biopsy and location of operative treatment, and has a certain potential for clinical application.

Efficacy of optical coherence tomography in the triage of women with minor abnormal cervical cytology before colposcopy

OBJECTIVES

To evaluate the efficacy of Optical Coherence Tomography (OCT) for detecting cervical lesions in women with minor abnormal cytology results (atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL)).

METHODS

A prospective study was conducted at gynecologic clinic from Mar 2021 to Sep 2021. The recruited women with cervical cytological findings of ASC-US or LSIL were inspected with OCT before colposcopy-directed cervical biopsy. The diagnostic performance of OCT, alone and in combination with high-risk human papillomavirus (hrHPV) testing were evaluated to detect cervical intraepithelial neoplasia of grade 2 or worse (CIN2+)/CIN3 or worse (CIN3+). The rate of colposcopy referral and the immediate risk of CIN3+ of OCT were calculated.

RESULTS

A total of 349 women with minor abnormal cervical cytology results were enrolled. For detection of CIN2+/CIN3+, the sensitivity and NPV of OCT were lower than those of hrHPV testing (CIN2+: 71.3% vs. 95.4%, 89.0% vs. 91.1%, P < 0.001; CIN3+: 75% vs. 93.8%, 96.5% vs. 95.6%, P < 0.001), but the specificity, accuracy and PPV were higher than those of hrHPV testing (CIN2+: 77.5% vs. 15.6%, 75.9% vs. 35.5%, 51.2% vs. 27.3%, P < 0.001; CIN3+: 69.4% vs. 13.6%, 69.9% vs. 20.9%, 19.8% vs. 9.9%, P < 0.001). OCT combined with hrHPV testing (CIN2+: 80.9%; CIN3+: 72.6%) showed higher specificity than that of OCT alone (P < 0.001). The colposcopy referral rate base on OCT classification was lower than that based on hrHPV testing (34.7% vs. 87.1%, P < 0.001). Patients with hrHPV-positive ASC-US and hrHPV-negative LSIL cytology, the immediate CIN3+ risk in OCT negative cases was less than 4%.

CONCLUSIONS

OCT alone or combination with hrHPV testing shows good performance for detecting CIN2+/CIN3+ in patients with ASC-US/LSIL cytology. OCT is an effective method for colposcopy triage in women with hrHPV-positive ASC-US and hrHPV-negative LSIL cytology.

Development of a multimodal mobile colposcope for real-time cervical cancer detection

Cervical cancer remains a leading cause of cancer death among women in low-and middle-income countries. Globally, cervical cancer prevention programs are hampered by a lack of resources, infrastructure, and personnel. We describe a multimodal mobile colposcope (MMC) designed to diagnose precancerous cervical lesions at the point-of-care without the need for biopsy. The MMC integrates two complementary imaging systems: 1) a commercially available colposcope and 2) a high speed, high-resolution, fiber-optic microendoscope (HRME). Combining these two image modalities allows, for the first time, the ability to locate suspicious cervical lesions using widefield imaging and then to obtain co-registered high-resolution images across an entire lesion. The MMC overcomes limitations of high-resolution imaging alone; widefield imaging can be used to guide the placement of the high-resolution imaging probe at clinically suspicious regions and co-registered, mosaicked high-resolution images effectively increase the field of view of high-resolution imaging. Representative data collected from patients referred for colposcopy at Barretos Cancer Hospital in Brazil, including 22,800 high resolution images and 9,900 colposcope images, illustrate the ability of the MMC to identify abnormal cervical regions, image suspicious areas with subcellular resolution, and distinguish between high-grade and low-grade dysplasia.

A unique Levey-Jennings control chart used for internal quality control in human papillomavirus detection

OBJECTIVE

The purpose of this study was to provide an updated estimate of the prevalences of different types of human papillomavirus (HPV) in females in Chaoshan District and to establish an internal quality control (IQC) method for excluding false-positive results in HPV detection by using the Levey-Jennings control chart.

METHOD

HPV types were detected in 23,762 cervical samples by using PCR membrane hybridization. The means and standard deviations (SDs) of the positive rates were calculated, the Levey-Jennings chart was plotted, and the rules for "out of control" and "warning" were established. A set of standardized IQC for HPV DNA tests was developed based on the values and Levey-Jennings charts.

RESULT

In 466 batches, the positive rate exceeded the 1 + 2SD rule 24 times, but there was no consecutive exceedance, which was considered "in control". When the positive rate exceeded the 1 + 3SD rule 8 times with consecutive exceedance, it was considered "out of control". Further examination revealed that detections showing "out of control" had an undesirable random error, indicating that contamination may occur due to improper operation.

CONCLUSION

This unique Levey-Jennings control chart is a practical method for eliminating false-positive results in HPV DNA detection and should be widely applicable in molecular diagnostic laboratories.

Research progress on the application of optical coherence tomography in the field of oncology

Optical coherence tomography (OCT) is a non-invasive imaging technique which has become the “gold standard” for diagnosis in the field of ophthalmology. However, in contrast to the eye, nontransparent tissues exhibit a high degree of optical scattering and absorption, resulting in a limited OCT imaging depth. And the progress made in the past decade in OCT technology have made it possible to image nontransparent tissues with high spatial resolution at large (up to 2mm) imaging depth. On the one hand, OCT can be used in a rapid, noninvasive way to detect diseased tissues, organs, blood vessels or glands. On the other hand, it can also identify the optical characteristics of suspicious parts in the early stage of the disease, which is of great significance for the early diagnosis of tumor diseases. Furthermore, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This review summarizes the recent advances in the OCT area, which application in oncological diagnosis and treatment in different types: (1) superficial tumors:OCT could detect microscopic information on the skin’s surface at high resolution and has been demonstrated to help diagnose common skin cancers; (2) gastrointestinal tumors: OCT can be integrated into small probes and catheters to image the structure of the stomach wall, enabling the diagnosis and differentiation of gastrointestinal tumors and inflammation; (3) deep tumors: with the rapid development of OCT imaging technology, it has shown great potential in the diagnosis of deep tumors such in brain tumors, breast cancer, bladder cancer, and lung cancer.

Study on the application and imaging characteristics of optical coherence tomography in vulva lesions

In this study, a prospective study was conducted by using optical coherence tomography (OCT) in the in vivo detection of vulvar diseases. The clinical efficacy of the OCT we investigated in the detection of vulvar diseases, and the characteristics of the OCT images were defined. Overall, this study recruited 63 patients undergoing the colposcopy for vulvar lesions in three Chinese hospitals from December 20th, 2018 and September 24th, 2019. The colposcopy and the OCT examination were performed successively, and the OCT images were compared with the relevant tissue sections to characterize different lesions. The OCT diagnoses where categorized into 7 types, including normal and inflammatory vulva, condyloma acuminata, papilloma, lichen sclerosus, atrophic sclerosing lichen, fibrous epithelial polyp as well as cysts. The structural characteristics of the vulva tissue can be clearly observed in the OCT image, which are consistent with the characteristics of the tissue section. Compared with the pathological results, the sensitivity, specificity and accuracy of the OCT examination reached 83.82% (95% confidence interval, CI 72.5%–91.3%), 57.89% (95% CI 34.0%–78.9%) and 78.16%, respectively. The OCT is found with the advantages of being noninvasive, real-time and sensitive and with high resolution. It is of high significance to screening vulva diseases, and it is expected as one of the methods to clinically diagnose vulva diseases.