The performance of Dynamic Spectral Imaging colposcopy depends on indication for referrals

Analysis of New Colposcopy Techniques in the Diagnosis and Evolution of SIL/CIN: Comparison of Colposcopy with the DSI System (COLPO-DSI Study)

Compared with conventional colposcopy, colposcopy assisted by DSI-map increases the detection of HSIL/CIN2+ and might help to identify the lesions more likely to regress.

INTRODUCTION

Comparison of the performance of colposcopy assisted by dynamic spectral imaging (C-DSI) with that of conventional colposcopy (CC) in the diagnosis of cervical intraepithelial neoplasia (HSIL/CIN2 or CIN3).

MATERIALS AND METHODS

A total of 1655 women were referred for colposcopy between 2012 and 2020 and included in the study. Of that total, 973 were examined by the same colposcopist with C-DSI, and 682 with CC. Comparisons between CC and C-DSI were made by using the histological diagnosis performed with a punch biopsy or loop electrosurgical excision procedure (LEEP) as the gold standard. A follow-up study was conducted until 2021 to detect progression to HSIL/CIN2 at 6, 12 and 24 months after first examination.

RESULTS

C-DSI provided higher sensitivity for the diagnosis of HSIL/CIN2 or CIN 3 than CC (sensitivity of 76.8% and 86.6% vs. 54.2% and 72.2%, respectively). In negative or ASCUS/LSIL Pap smear results, C-DSI showed higher sensitivity than CC (sensitivity of 66.7% and 61.5% vs. 21.4% and 33.3%, respectively). In contrast, these differences were not observed in high-grade Pap smears. The sensitivity of C-DSI in cases with HPV16/18 infection was stronger than that of CC (73.53% vs. 56.67%). The sensitivity of C-DSI to detect the progression to HSIL/CIN2+ during follow-up was 30, 17.6 and 35.7% at 6, 12 and 24 months, respectively.

CONCLUSIONS

The present study shows that C-DSI in women referred for colposcopy increases the HSIL/CIN 2-3 detection rate compared to conventional colposcopy. Nevertheless, C-DSI does not seem to be an important tool to predict the evolution of the lesions during follow-up.

European consensus statement on expert colposcopy

BACKGROUND

Following the publication of the European consensus statement on standards for essential colposcopy in 2020, the need for standards relating to more complex and challenging colposcopy practice was recognised. These standards relate to colposcopy undertaken in patients identified through cervical screening and tertiary referrals from colposcopists who undertake standard colposcopy only. This set of recommendations provides a review of the current literature and agreement on care for recognised complex cases. With good uptake of human papillomavirus (HPV) immunisation, we anticipate a marked reduction in cervical disease over the next decade. Still, the expert colposcopist will continue to be vital in managing complex cases, including previous cervical intraepithelial neoplasia (CIN)/complex screening histories and multi-zonal disease.

AIMS

To provide expert guidance on complex colposcopy cases through published evidence and expert consensus.

MATERIAL & METHODS

Members of the EFC and ESGO formed a working group to identify topics considered to be the remit of the expert rather than the standard colposcopy service. These were presented at the EFC satellite meeting, Helsinki 2021, for broader discussion and finalisation of the topics.

RESULTS & DISCUSSION

The agreed standards included colposcopy in pregnancy and post-menopause, investigation and management of glandular abnormalities, persistent high-risk HPV+ with normal/low-grade cytology, colposcopy management of type 3 transformation zones (TZ), high-grade cytology and normal colposcopy, colposcopy adjuncts, follow-up after treatment with CIN next to TZ margins and follow-up after treatment with CIN with persistent HPV+, and more. These standards are under review to create a final paper of consensus standards for dissemination to all EFC and ESGO members.

Value of colposcopy with dynamic spectral imaging in the detection and evolution of high-grade cervical lesions

OBJECTIVE

To analyze the performance of colposcopy assisted with dynamic spectral imaging (CC-DSI) compared to conventional colposcopy (CC) in diagnosing cervical intraepithelial neoplasia 2+ (CIN2+).

METHODS

: 973 consecutive women were referred for colposcopy between 2012 and 2016 and were examined simultaneously by CC and CC-DSI; 877 were eligible. Comparisons between CC and CC-DSI were performed against the histological diagnosis performed by either punch biopsy or loop electrosurgical excision procedure (LEEP).

RESULTS

: In final histology, 494 women had no CIN, 250 had CIN1 and 133 had CIN2+. The sensitivity to identify women with CIN2+ was significantly higher for CC-DSI compared to CC for the entire group and in the subgroup of 675 women referred with ASCUS or LSIL. In women with HPV16/18 infections, the sensitivity of CC increased with the addition of DSI from 53% to 79% (p<0.001). Using a multivariant Cox regression model, CC-DSI was an independent factor for progression of the cervical lesions (HR: 2.29, 95%CI 1.07-4.90). Other predictive factors were the number of sexual partners (HR: 1.05, 95%CI: 1.01-1.09) and anal intercourse (HR: 2.45, 95%CI 1.23-5.02).

CONCLUSION

CC-DSI improves the ability to detect cervical lesions compared to CC and could help predict their potential to progress.

Dynamic Spectral Imaging Colposcopy Versus Regular Colposcopy in Women Referred With High-Grade Cytology: A Nonrandomized Prospective Study

OBJECTIVE

The aim of the study was to evaluate the sensitivity of dynamic spectral imaging (DSI) colposcopy compared with regular colposcopy for women referred with high-grade cervical cytology.

METHODS

In a prospective, nonrandomized, multicenter study, we included women referred for colposcopy at hospital gynecology clinics with high-grade cytology. Women were examined using either a regular or DSI colposcope. In both groups, colposcopists located 1 area viewed as most suspicious. In the DSI group, this was done before viewing the DSI map. Subsequently, an area was chosen based on the worst color of the DSI map, and further additional biopsies were taken. All women had 4 cervical biopsies taken, all analyzed separately. The main outcome was sensitivity to find cervical intraepithelial neoplasia grade 2 or worse (CIN2+).

RESULTS

A total of 261 women were examined using DSI colposcopy, and 156 women were examined using regular colposcopy. The sensitivity for finding CIN2+ when using the DSI technology as an adjunctive technology was found to be 82.2% (95% CI = 75.9-87.4), based on an average of 1.4 biopsies. This was corresponding in sensitivity to 2 biopsies taken using regular colposcopy (80.3%; 95% CI = 72.3-86.8). There was no difference in sensitivity for CIN+ between the groups when 3 or more biopsies were taken.

CONCLUSIONS

We found that the DSI colposcope may help direct biopsy placement; however, the improvement is based on small differences in needed biopsies and the clinical significance of this may be small. Multiple biopsies were still superior.

Can the dynamic spectral imaging (DSI) color map improve colposcopy examination for precancerous cervical lesions? A prospective evaluation of the DSI color map in a multi-biopsy clinical setting

Background

Colposcopy serves as a subjective examination of the cervix with low sensitivity to detect cervical intraepithelial dysplasia (CIN) grade 2 or worse (CIN2 +). Dynamic spectral imaging (DSI) colposcopy has been developed to provide an objective element to cervix examinations and has been proven to increase sensitivity of detecting CIN2 + . We aimed to assess the performance of the DSI color map and compared it to histological diagnoses of cervical biopsies in determining the CIN grade present.

Methods

Women were included in a consecutive, prospective manner at Randers Regional Hospital, Denmark. Women were eligible to participate if they were referred for colposcopy due to abnormal cervical smear (threshold:  ≥ ASCUS) or follow-up after previously diagnosed CIN. All women had four biopsies taken, one directed by colposcopists alone prior to viewing the DSI color map, one directed by the worst color on the respective DSI color map, and two additional biopsies. All biopsies were analyzed separately. We calculated sensitivity, specificity, positive predictive values, and negative predictive values (NPVs) with 95% confidence intervals (CIs).

Results

A total of 800 women were recruited. Of these, 529 (66.1%) were eligible for inclusion. The sensitivity of the DSI color map was found to be 48.1% (95% CI 41.1–55.1) in finding CIN grade 2 or worse (CIN2 +) when compared to the histological diagnosis of the DSI directed biopsy. This was 42.5% (95% CI 36.7–48.5) when compared to the final histological diagnosis of all four cervical biopsies and with an NPV of 53.5% (95% CI 50.5–56.5).

Conclusion

The worst color indicated by the DSI map might not consistently reflect the true grade of cervical dysplasia present. Thus, even though the DSI color map indicates low-grade changes, colposcopists should still consider taking biopsies from the area as high-grade changes might be present.

Trial registration: NCT04249856, January 31 2020 (retrospectively registered).

Label-free, High-Resolution Optical Metabolic Imaging of Human Cervical Precancers Reveals Potential for Intraepithelial Neoplasia Diagnosis

While metabolic changes are considered a cancer hallmark, their assessment has not been incorporated in the detection of early or precancers, when treatment is most effective. Here, we demonstrate that metabolic changes are detected in freshly excised human cervical precancerous tissues using label-free, non-destructive imaging of the entire epithelium. The images rely on two-photon excited fluorescence from two metabolic co-enzymes, NAD(P)H and FAD, and have micron-level resolution, enabling sensitive assessments of the redox ratio and mitochondrial fragmentation, which yield metrics of metabolic function and heterogeneity. Simultaneous characterization of morphological features, such as the depth-dependent variation of the nuclear:cytoplasmic ratio, is demonstrated. Multi-parametric analysis combining several metabolic metrics with morphological ones enhances significantly the diagnostic accuracy of identifying high-grade squamous intraepithelial lesions. Our results motivate the translation of such functional metabolic imaging to in vivo studies, which may enable improved identification of cervical lesions, and other precancers, at the bedside.

Accuracy of colposcopy-directed biopsy vs dynamic spectral imaging directed biopsy in correctly identifying the grade of cervical dysplasia in women undergoing conization: A methodological study

INTRODUCTION

Dynamic spectral imaging (DSI) colposcopy has previously been found to improve sensitivity of CIN2+ detection. The aim of this study was to compare the histological diagnosis of colposcopic-directed biopsies (CDB) with that of DSI-directed biopsies in women undergoing conization, using the histological diagnosis of the conization specimen as gold standard.

MATERIAL AND METHODS

Women referred for colposcopy were included in a prospective cohort study at Randers Regional Hospital, Denmark, from January 2016 to February 2019. All women had four cervical punch biopsies taken. The first biopsy was taken from the area that appeared most abnormal by conventional colposcopy (ie, CDB) and the second biopsy from the area that appeared most abnormal using the DSI map. An additional two biopsies were taken either from other visible lesions or as random biopsies. Biopsies were analyzed separately. If any biopsies revealed cervical dysplasia of such a degree that excisional treatment was recommended, the patient was referred for conization. Subsequently, we compared the histological diagnosis of CDB and DSI-directed biopsies with that of the cone biopsy.

RESULTS

A total of 573 women were enrolled, 170 of which underwent conization. In women with an adequate colposcopy and representative biopsies (n = 124) there was an overall agreement rate between the worst biopsy diagnosis (of any four) and the conization diagnosis in 95.2% (95% CI 89.8-98.2) of women. CDB diagnosis agreed with the cone diagnosis in 80.6% (95% CI 72.6-87.2) of women. DSI-directed biopsy agreed with the cone diagnosis in 83.9% (95% CI 76.2-89.9) of women. The difference in detection rate between the CDB and the DSI-directed biopsy was, however, not significant (P = .54). Taking four biopsies increases the detection rate of cervical dysplasia to 95.2%, which was a significant increase from both CDB alone (P = .0008) and DSI-directed biopsy alone (P = .0053).

CONCLUSIONS

We found no significant difference in the ability to identify the cervical dysplasia grade between CDB and DSI-directed biopsies. A higher detection rate of cervical dysplasia was achieved with four biopsies than with one CDB biopsy or one DSI-directed biopsy.

Adjunctive colposcopy technologies for assessing suspected cervical abnormalities: systematic reviews and economic evaluation

BACKGROUND

Dynamic Spectral Imaging System (DySIS)map (DySIS Medical Ltd, Edinburgh, UK) and ZedScan (Zilico Limited, Manchester, UK) can be used adjunctively with conventional colposcopy, which may improve the detection of cervical intraepithelial neoplasia (CIN) and cancer.

OBJECTIVES

To systematically review the evidence on the diagnostic accuracy, clinical effectiveness and implementation of DySISmap and ZedScan as adjuncts to standard colposcopy, and to develop a cost-effectiveness model.

METHODS

Four parallel systematic reviews were performed on diagnostic accuracy, clinical effectiveness issues, implementation and economic analyses. In January 2017 we searched databases (including MEDLINE and EMBASE) for studies in which DySISmap or ZedScan was used adjunctively with standard colposcopy to detect CIN or cancer in women referred to colposcopy. Risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. Summary estimates of diagnostic accuracy were calculated using bivariate and other regression models when appropriate. Other outcomes were synthesised narratively. A patient-level state-transition model was developed to evaluate the cost-effectiveness of DySISmap and ZedScan under either human papillomavirus (HPV) triage or the HPV primary screening algorithm. The model included two types of clinics ['see and treat' and 'watchful waiting' (i.e. treat later after confirmatory biopsy)], as well as the reason for referral (low-grade or high-grade cytological smear). Sensitivity and scenario analyses were undertaken.

RESULTS

Eleven studies were included in the diagnostic review (nine of DySISmap and two of ZedScan), three were included in the clinical effectiveness review (two of DySISmap and one of ZedScan) and five were included in the implementation review (four of DySISmap and one of ZedScan). Adjunctive DySISmap use was found to have a higher sensitivity for detecting CIN grade 2+ (CIN 2+) lesions [81.25%, 95% confidence interval (CI) 72.2% to 87.9%] than standard colposcopy alone (57.91%, 95% CI 47.2% to 67.9%), but with a lower specificity (70.40%, 95% CI 59.4% to 79.5%) than colposcopy (87.41%, 95% CI 81.7% to 91.5%). (Confidential information has been removed.) The base-case cost-effectiveness results showed that adjunctive DySISmap routinely dominated standard colposcopy (it was less costly and more effective). The only exception was for high-grade referrals in a watchful-waiting clinic setting. The incremental cost-effectiveness ratio for ZedScan varied between £272 and £4922 per quality-adjusted life-year. ZedScan also dominated colposcopy alone for high-grade referrals in see-and-treat clinics. These findings appeared to be robust to a wide range of sensitivity and scenario analyses.

LIMITATIONS

All but one study was rated as being at a high risk of bias. There was no evidence directly comparing ZedScan with standard colposcopy. No studies directly compared DySIS and ZedScan.

CONCLUSIONS

The use of adjunctive DySIS increases the sensitivity for detecting CIN 2+, so it increases the number of high-grade CIN cases that are detected. However, it also reduces specificity, so that more women with no or low-grade CIN will be incorrectly judged as possibly having high-grade CIN. The evidence for ZedScan was limited, but it appears to increase sensitivity and decrease specificity compared with colposcopy alone. The cost-effectiveness of both adjunctive technologies compared with standard colposcopy, under both the HPV triage and primary screening algorithms, appears to be favourable when compared with the conventional thresholds used to determine value in the NHS.

FUTURE WORK

More diagnostic accuracy studies of ZedScan are needed, as are studies assessing the diagnostic accuracy for women referred to colposcopy as part of the HPV primary screening programme.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017054515.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Increased detection of precancerous cervical lesions with adjunctive dynamic spectral imaging

Objective

To validate, in US community-based colposcopy clinics, previous reports of increased detection of high-grade cervical intraepithelial neoplasia (CIN2+) with biopsies selected using dynamic spectral imaging (DSI) mapping after standard colposcopy.

Study design

Cross-sectional observational study of 26 colposcopists across nine clinics recruiting consecutive colposcopy patients. Standard assessment with biopsy selections was completed before seeing the DSI map which was subsequently interpreted and used for additional biopsies per clinical judgment. Primary measure was the number of women with CIN2+ detected by DSI-assisted biopsies, over those detected by standard colposcopy biopsies.

Results

A total of 887 women were recruited. After exclusions, 881 women and 1,189 biopsies were analyzed. Standard biopsy detected 78 women with CIN2+ and DSI-assisted biopsies another 34, increasing the detection rate from 8.85% to 12.71% (p=0.00016). This was achieved with 16.16% of DSI-assisted biopsies finding CIN2+ compared to 13.24% for the preceding standard biopsies. For secondary specificity analysis, 431 women had only <CIN2 in standard biopsy/ies, a 48.92% rate, while 131 women who underwent no standard biopsy/ies had DSI-assisted biopsy/ies which were all <CIN2, a 35.22% rate (p<0.0001).

Conclusion

The largest study, to date, of DSI used in colposcopy confirms previously reported increased detection of CIN2+, across multiple US community-based clinics. Based on the improved efficiency of the DSI-assisted biopsies, this increase suggests an improved diagnostic capacity achieved with DSI and cannot be explained solely by the taking of additional biopsies.

Optimization of Classification Strategies of Acetowhite Temporal Patterns towards Improving Diagnostic Performance of Colposcopy

Efforts have been being made to improve the diagnostic performance of colposcopy, trying to help better diagnose cervical cancer, particularly in developing countries. However, improvements in a number of areas are still necessary, such as the time it takes to process the full digital image of the cervix, the performance of the computing systems used to identify different kinds of tissues, and biopsy sampling. In this paper, we explore three different, well-known automatic classification methods (k-Nearest Neighbors, Naïve Bayes, and C4.5), in addition to different data models that take full advantage of this information and improve the diagnostic performance of colposcopy based on acetowhite temporal patterns. Based on the ROC and PRC area scores, the k-Nearest Neighbors and discrete PLA representation performed better than other methods. The values of sensitivity, specificity, and accuracy reached using this method were 60% (95% CI 50–70), 79% (95% CI 71–86), and 70% (95% CI 60–80), respectively. The acetowhitening phenomenon is not exclusive to high-grade lesions, and we have found acetowhite temporal patterns of epithelial changes that are not precancerous lesions but that are similar to positive ones. These findings need to be considered when developing more robust computing systems in the future.