Narrow-band imaging in diagnosis of endometrial cancer and hyperplasia: a new option?

A Predictive Model for Endometrial Carcinoma Based on Hysteroscopic Data

Objective

The purpose is to establish a model to predict endometrial carcinoma and assess its value in the preliminary diagnosis of endometrial carcinoma.

Methods

The data of 381 patients undergoing hysteroscopy were incorporated into the model, including 282 cases in the training cohort and 99 cases in the validation cohort. Significant morphological indexes were selected using the chi-square test and subjected to the binary logistic regression analysis. Besides, the scoring interval was set, and the nomogram of the prediction model was established. Model calibration curves were drawn using the data from the validation cohort. The study was approved by the Ethics Committee of the Affiliated Sir Run Run Hospital of Nanjing Medical University, and written informed consent was obtained from the patients.

Results

The sensitivity, specificity, positive predictive value, and negative predictive value of the model were 96.7%, 92.3%, 77.3%, and 99.0%, respectively. Analysis of the receiver operating characteristic curve in the training cohort showed an area under the curve of 0.984 (95% CI: 0.974-0.995). The receiver operating characteristic curve in the validation cohort revealed an area under the curve of 0.976 (95% CI: 0.950-1.000). The calibration curve indicated that the probability in the actual setting was consistent with that predicted by the nomogram in the training cohort.

Conclusion

Our model has high sensitivity and specificity in predicting endometrial carcinoma, and helps clinicians to make accurate diagnosis.

Rare case of endometrial vascular dystrophy: Three case reports

RATIONALE

Endometrial vascular dystrophy refers to abnormal vessels that are very tortuous, dilated, and sometimes thrombosed. Endometrial vascular dystrophy is rare under hysteroscopy.

PATIENT

All three patients had a history of abnormal uterine bleeding. The duration of vaginal bleeding ranged from 1 month to 2 years. There was no history of unusual diseases, alcohol or drug abuse, or genetic history.

DIAGNOSES

Endometrial vascular dystrophy.

INTERVENTION

Three patients underwent hysteroscopy and curettage under intravenous general anesthesia. Pathological examination showed secretory endometrium, with one case coexisting with endometrial polyps.

OUTCOMES

No recurrence was found during postoperative follow-up at 12 months.

LESSONS

Endometrial vascular dystrophy is a rare hysteroscopy phenomenon shown in the secretory endometrium. We believe that it was a capillary loop with different manifestations.

Improving tissue characterization, differentiation and diagnosis in gynecology with the narrow-band imaging technique: A systematic review

Narrow-band imaging (NBI), an on-demand, real-time endoscopic imaging technique, was developed to enhance visualization of the mucosal vascular network and surface texture. The present article provides a systematic review of studies that assessed the use of NBI in gynecological endoscopy. The following electronic databases were searched: PubMed (1950-2020), Google Scholar (2004-2020) and Cochrane Library (2010-2020). In the initial search, 3,836 entries were identified, of which 31 were finally included in the systematic review. Of the selected studies, 10 (32%) were case reports, 19 (61.2%) were prospective studies and 2 (6.4%) were randomized controlled trials with control groups. The selected studies reported on the use of NBI in hysteroscopy, laparoscopy and colposcopy. It was revealed that NBI utilization in hysteroscopy increased the accuracy, sensitivity and specificity in detecting malignant and premalignant lesions. NBI improved the specificity and sensitivity in the detection of endometriotic lesions and cervical lesions. Conventional white light endoscopy in gynecology may be significantly improved by the use of NBI. Further studies with larger cohorts and improved design are required to achieve more reliable results. It is of special interest that utilization of this method requires apparatus which is expensive; concerns are the long training and experience of staff required and the long learning curve.

Clinically Available Optical Imaging Technologies in Endoscopic Lesion Detection: Current Status and Future Perspective

Endoscopic optical imaging technologies for the detection and evaluation of dysplasia and early cancer have made great strides in recent decades. With the capacity of in vivo early detection of subtle lesions, they allow modern endoscopists to provide accurate and effective optical diagnosis in real time. This review mainly analyzes the current status of clinically available endoscopic optical imaging techniques, with emphasis on the latest updates of existing techniques. We summarize current coverage of these technologies in major hospital departments such as gastroenterology, urology, gynecology, otolaryngology, pneumology, and laparoscopic surgery. In order to promote a broader understanding, we further cover the underlying principles of these technologies and analyze their performance. Moreover, we provide a brief overview of future perspectives in related technologies, such as computer-assisted diagnosis (CAD) algorithms dealing with exploring endoscopic video data. We believe all these efforts will benefit the healthcare of the community, help endoscopists improve the accuracy of diagnosis, and relieve patients' suffering.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

Prospective Comparative Study of Laparoscopic Narrow Band Imaging (NBI) Versus Standard Imaging in Gynecologic Oncology

BACKGROUND

Narrow band imaging (NBI) is an optic filtration enhancement for endoscopy that uses two wavelengths of light (415 and 540 nm) to highlight superficial microvascular patterns. It has been successfully utilized to improve identification of lesions with abnormal vasculature, which is associated with endometriosis and endometrial cancer. Case studies suggest it may also facilitate surgical staging of gynecologic cancer, which is critical in determining appropriate adjuvant therapies. A technology that enhances the ability to identify metastatic disease during minimally invasive surgery (MIS) could make an important difference in patient outcomes.

METHODS

A prospective comparative study was conducted to evaluate patients with clinical indication for diagnostic or operative laparoscopy. All received white light imaging followed by NBI during the same procedure. Suspicious lesions were examined and photographed, using both modalities, before excision. The two techniques were compared. Positive predictive value, negative predictive value, and diagnostic accuracy in identifying histologically confirmed metastatic lesions were assessed, using appropriate statistical methods.

RESULTS

Of 124 patients enrolled in the study, 94 were evaluable; 30 did not undergo MIS and were therefore excluded. A significantly higher number of peritoneal abnormalities were identified with NBI versus white light imaging (P = 0.0239). However, no statistically significant difference (P = 0.18, patient level) was observed in identification of histologically confirmed metastatic disease.

CONCLUSIONS

NBI imaging provides a unique contrast between peritoneal surface and microvascular patterns. However, the results of this study suggest that NBI-enhanced laparoscopy does not provide superior detection of peritoneal surface malignancy compared with standard white light high-definition laparoscopy.

Sensitivity of Narrow Band Imaging Compared With White Light Imaging for the Detection of Endometriosis

STUDY OBJECTIVE

To evaluate the ability of narrow band imaging (NBI) in conjunction with standard white light imaging to improve the detection and diagnosis of endometriosis during laparoscopic evaluation compared with white light imaging alone. Sensitivity of NBI in detecting endometriosis was assessed and compared with white light imaging.

DESIGN

Randomized controlled trial.

CLASSIFICATION OF STUDY DESIGN

LEVEL I: Evidence obtained from a properly designed, randomized, controlled trial.

SETTING

The trial was conducted in 2 medical centers.

PATIENTS

One hundred sixty-seven women undergoing laparoscopic evaluation for suspected endometriosis and/or infertility were recruited. Of these, 150 were assessable to determine sensitivity of NBI compared with white light imaging for the detection of endometriotic lesions.

INTERVENTIONS

Patients were randomized in a 3:1 ratio to receive white light imaging followed by NBI or white light imaging only. The pelvis was systematically visualized with each assigned imaging modality; lesions were recorded under each visualization and then resected. All patients had white light imaging on the first visualization followed by either a second white light examination (control arm) or NBI examination (intervention arm).

MEASUREMENTS

Pathology of resected lesions was the criterion standard for evaluating sensitivity and was conducted at each institution. The method of detection of the lesion (white light or NBI) was masked. Central pathology review was conducted for a randomly selected 10% sample of specimens and for those lesions visualized under only 1 imaging modality among patients assigned to the intervention arm. The sensitivity was assessed for each modality (white light and NBI) and compared using a McNemar's test.

MAIN RESULTS

Among the group randomized to receive both white light and NBI, 4 patients had lesions detected with NBI but no lesions detected with white light. Among the 255 lesions confirmed as endometriosis by pathologic review, all were detected by NBI for a sensitivity of 100%; 79% were detected by white light imaging (p < .001).

CONCLUSION

The addition of NBI to white light imaging increased the number of endometriotic lesions identified during laparoscopy and the diagnosis of endometriosis compared with the use of white light imaging alone.

Accuracy and efficacy of narrow-band imaging versus white light hysteroscopy for the diagnosis of endometrial cancer and hyperplasia: a multicenter controlled study

OBJECTIVE

The aim of this study was to evaluate, in a multicenter study, whether the narrow-band imaging (NBI) technology may improve the diagnostic reliability of hysteroscopy in the diagnosis of endometrial cancer and hyperplasia.

METHODS

A total of 801 outpatient women undergoing diagnostic hysteroscopy were enrolled. All women underwent fluid minihysteroscopy with white light (WL) and NBI exploration with endometrial eye-directed biopsy.

RESULTS

NBI hysteroscopy significantly improved the sensitivity for diagnosing endometrial cancer compared with WL (93% and 81%, P < 0.05). In detecting low-risk hyperplasia, the use of NBI significantly improved the sensitivity (82% vs 56%, P < 0.005) and positive predictive value (79% and 71%, P < 0.05) compared with WL hysteroscopy. In the diagnosis of high-risk hyperplasia, NBI significantly improved the sensitivity (60% vs 20%, P < 0.005) and positive predictive value (67% and 25%, P < 0.0001), whereas no difference was seen for specificity (99% and 99%, P > 0.005), negative predictive value (99% and 99%, P > 0.05), and accuracy (99% and 98%, P > 0.05).

CONCLUSIONS

NBI showed significantly higher values in sensitivity for the detection of low-risk and high-risk hyperplasia, and this could be useful for reducing the risk of missing severe pathologies at hysteroscopy, and improving the diagnosis of preneoplastic and neoplastic pathologies. NBI hysteroscopy showed a very high diagnostic accuracy for the exploration of the uterine cavity, reducing the number of biopsies performed in wrong areas, although multicenter randomized trials are required to establish the true value of this interesting technological advancement.