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2. Self-supervised learning-based cervical cytology for the triage of HPV-positive women in resource-limited settings and low-data regime

Author

Stegmüller, Thomas, Abbet, Christian, Bozorgtabar, Behzad, Clarke, Holly, Petignat, Patrick, Vassilakos, Pierre, and Thiran, Jean-Philippe

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

Screening Papanicolaou test samples has proven to be highly effective in reducing cervical cancer-related mortality. However, the lack of trained cytopathologists hinders its widespread implementation in low-resource settings. Deep learning-based telecytology diagnosis emerges as an appealing alternative, but it requires the collection of large annotated training datasets, which is costly and time-consuming. In this paper, we demonstrate that the abundance of unlabeled images that can be extracted from Pap smear test whole slide images presents a fertile ground for self-supervised learning methods, yielding performance improvements relative to readily available pre-trained models for various downstream tasks. In particular, we propose \textbf{C}ervical \textbf{C}ell \textbf{C}opy-\textbf{P}asting ($\texttt{C}^{3}\texttt{P}$) as an effective augmentation method, which enables knowledge transfer from open-source and labeled single-cell datasets to unlabeled tiles. Not only does $\texttt{C}^{3}\texttt{P}$ outperforms naive transfer from single-cell images, but we also demonstrate its advantageous integration into multiple instance learning methods. Importantly, all our experiments are conducted on our introduced \textit{in-house} dataset comprising liquid-based cytology Pap smear images obtained using low-cost technologies. This aligns with our objective of leveraging deep learning-based telecytology for diagnosis in low-resource settings.

Published
2023

14. Factors influencing cervical cancer re-screening in a semi-rural health district of Cameroon: a cohort study.

Author

Evina Bolo, Sophie, Kenfack, Bruno, Wisniak, Ania, Tankeu, Gilles, Yakam, Virginie, Moukam, Alida, Sormani, Jessica, Stoll, Beat, Vassilakos, Pierre, and Petignat, Patrick

Subjects
CERVICAL cancer, COHORT analysis, MEDICAL screening, CANCER prevention, EARLY detection of cancer
Abstract

Background: Screening participation at recommended intervals is a crucial component of cervical cancer prevention effectiveness. However, little is known regarding the rate of re-screening in a Sub-Saharan context. This study aimed to estimate the re-screening rate of women in a semi-rural after an initial HPV-based screening and identify factors that influence adherence. Methods: This cohort study at the Annex Regional Hospital of Dschang enrolled women screened for cervical cancer over 5 years ago and due for re-screening. Women who initially tested HPV-positive (n = 132) and a random sample of HPV-negative women (n = 220) participated in a telephone survey between October 2021 and March 2022 to assess re-screening participation and reasons. Sociodemographic factors were collected, and associations with rescreening were evaluated. Results: A total of 352 participants aged under 50 years (mean age 37.4 years) were contacted, and 203 (58.0%) completed the survey. The proportion of women who complied with the screening recommendation was 34.0% (95% CI 27.5% − 40.5%), The weighted re-screening proportion was 28.4%. Age, marital status, education level, type of employment, and place of residence were not associated with the rate of re-screening. Main reported barriers to re-screening were lack of information (39.0%), forgetfulness (39.0%), and impression of being in good health (30.0%). Women who remembered the recommended screening interval were 2 to 3 times more likely to undergo re-screening (aOR (adjusted odds ratio) = 2.3 [1.2–4.4], p = 0.013). Human papilloma virus- positive status at the initial screening was also associated with the re-screening((aOR) (95% CI): 3.4 (1.8–6.5). Conclusion: Following an initial Human Papilloma Virus-based screening campaign in the West Region of Cameroon, one third of women adhered to re-screening within the recommended timeframe. Existing screening strategies would benefit from developing better information approaches to reinforce the importance of repeated cervical cancer screening. [ABSTRACT FROM AUTHOR]

Published
2024
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17. Smartphone-Based Visual Inspection with Acetic Acid: An Innovative Tool to Improve Cervical Cancer Screening in Low-Resource Setting

Author

Sami, Jana, Makajio, Sophie Lemoupa, Jeannot, Emilien, Kenfack, Bruno, Vinals, Roser, Vassilakos, Pierre, Petignat, Patrick, Sami, Jana, Makajio, Sophie Lemoupa, Jeannot, Emilien, Kenfack, Bruno, Vinals, Roser, Vassilakos, Pierre, and Petignat, Patrick

Abstract

Visual inspection with acetic acid (VIA) is recommended by theWorld Health Organization for primary cervical cancer screening or triage of human papillomavirus-positive women living in low-resource settings. Nonetheless, traditional VIA with the naked-eye is associated with large variabilities in the detection of pre-cancer and with a lack of quality control. Digital-VIA (D-VIA), using high definition cameras, allows magnification and zooming on transformation zones and suspicious cervical regions, as well as simultaneously compare native and post-VIA images in real-time. We searched MEDLINE and LILACS between January 2015 and November 2021 for relevant studies conducted in low-resource settings using a smartphone device for D-VIA. The aim of this review was to provide an evaluation on available data for smartphone use in low-resource settings in the context of D-VIA-based cervical cancer screenings. The available results to date show that the quality of D-VIA images is satisfactory and enables CIN1/CIN2+ diagnosis, and that a smartphone is a promising tool for cervical cancer screening monitoring and for on- and off-site supervision, and training. The use of artificial intelligence algorithms could soon allow automated and accurate cervical lesion detection.

Published
2023
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18. Artificial Intelligence-Based Cervical Cancer Screening on Images Taken during Visual Inspection with Acetic Acid: A Systematic Review

Author

Vinals, Roser, Jonnalagedda, Magali, Petignat, Patrick, Thiran, Jean-Philippe, Vassilakos, Pierre, Vinals, Roser, Jonnalagedda, Magali, Petignat, Patrick, Thiran, Jean-Philippe, and Vassilakos, Pierre

Abstract

Visual inspection with acetic acid (VIA) is one of the methods recommended by the World Health Organization for cervical cancer screening. VIA is simple and low-cost; it, however, presents high subjectivity. We conducted a systematic literature search in PubMed, Google Scholar and Scopus to identify automated algorithms for classifying images taken during VIA as negative (healthy/benign) or precancerous/cancerous. Of the 2608 studies identified, 11 met the inclusion criteria. The algorithm with the highest accuracy in each study was selected, and some of its key features were analyzed. Data analysis and comparison between the algorithms were conducted, in terms of sensitivity and specificity, ranging from 0.22 to 0.93 and 0.67 to 0.95, respectively. The quality and risk of each study were assessed following the QUADAS-2 guidelines. Artificial intelligence-based cervical cancer screening algorithms have the potential to become a key tool for supporting cervical cancer screening, especially in settings where there is a lack of healthcare infrastructure and trained personnel. The presented studies, however, assess their algorithms using small datasets of highly selected images, not reflecting whole screened populations. Large-scale testing in real conditions is required to assess the feasibility of integrating those algorithms in clinical settings.

Published
2023
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25. Telecytologic diagnosis of cervical smears for the triage of self-sampled human papillomavirus-positive women in a resource-limited setting: concept development before implementation

Author

Vassilakos, Pierre, primary, Clarke, Holly, additional, Murtas, Micol, additional, Stegmüller, Thomas, additional, Wisniak, Ania, additional, Akhoundova, Farida, additional, Sando, Zacharie, additional, Orock, George Enow, additional, Sormani, Jessica, additional, Thiran, Jean-Philippe, additional, and Petignat, Patrick, additional

Published
2023
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27. Utility of extended HPV genotyping for the triage of self-sampled HPV-positive women in a screen-and-treat strategy for cervical cancer prevention in Cameroon: a prospective study of diagnostic accuracy

Author

Broquet, Celine, primary, Vassilakos, Pierre, additional, Ndam Nsangou, François Marcel, additional, Kenfack, Bruno, additional, Noubom, Michel, additional, Tincho, Evelyn, additional, Jeannot, Emilien, additional, Wisniak, Ania, additional, and Petignat, Patrick, additional

Published
2022
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30. A Smartphone-Based Approach for Triage of Human Papillomavirus-Positive Sub-Saharan African Women: A Prospective Study

Author

Urner, Esther, Delavy, Martine, Catarino, Rosa, Viviano, Manuela, Meyer-Hamme, Ulrike, Benski, Anne-Caroline, Jinoro, Jeromine, Heriniainasolo, Josea Lea, Undurraga, Manuela, De Vuyst, Hugo, Combescure, Christophe, Vassilakos, Pierre, and Petignat, Patrick

Subjects
Information technology, T58.5-58.64, Public aspects of medicine, RA1-1270
Abstract

BackgroundSub-Saharan African countries are marked by a high incidence of cervical cancer. Madagascar ranks 11th among the countries with the highest cervical cancer incidence worldwide. ObjectiveThe aim of the study was to evaluate the performances of digital smartphone-based visual inspection with acetic acid (D-VIA) and Lugol’s iodine (D-VILI) for diagnosing cervical precancer and cancer. MethodsHuman papillomavirus (HPV)-positive women recruited through a cervical screening campaign had D-VIA and D-VILI examinations with endocervical curettage (ECC) and cervical biopsy. Three images were captured for each woman (native, D-VIA, D-VILI) using a smartphone camera. The images were randomly coded and distributed on 2 online databases (Google Forms). The D-VIA form included native and D-VIA images, and the D-VILI form included native and D-VILI images. Pathological cases were defined as cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Physicians rated the images as non-pathological or pathological. Using the ECC and cervical biopsy results as references, the sensitivity and specificity of D-VIA and D-VILI examinations for each and all physicians were calculated. ResultsAltogether, 15 clinicians assessed 240 images. Sensitivity was higher for the D-VIA interpretations (94.1%; 95% CI 81.6-98.3) than for the D-VILI interpretations (78.8%; 95% CI 54.1-92.1; P=.009). In contrast, the specificity was higher for the D-VILI interpretations (56.4%; 95% CI 38.3-72.9) than for the D-VIA interpretations (50.4%; 95% CI 35.9-64.8; P=.005). ConclusionSmartphone-based image for triage of HPV-positive women is more accurate for detecting CIN2+ lesions with D-VIA than D-VILI, although with a small loss of specificity.

Published
2017
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33. Training, Supervision, and Competence Assessment of Cameroonian Health Care Providers Using HPV Self-Sampling, Triage by Visual Inspection, and Treatment by Thermal Ablation in a Single Visit

Author

Frund, Chloé, primary, Kenfack, Bruno, additional, Sormani, Jessica, additional, Wisniak, Ania, additional, Fouogue, Jovanny Tsuala, additional, Tincho, Eveline, additional, Metaxas, Tania, additional, Vassilakos, Pierre, additional, and Petignat, Patrick, additional

Published
2022
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37. Study protocol for a two-site clinical trial to validate a smartphone-based artificial intelligence classifier identifying cervical precancer and cancer in HPV-positive women in Cameroon

Author

Baleydier, Inès, primary, Vassilakos, Pierre, additional, Viñals, Roser, additional, Wisniak, Ania, additional, Kenfack, Bruno, additional, Tsuala Fouogue, Jovanny, additional, Enownchong Enow Orock, George, additional, Lemoupa Makajio, Sophie, additional, Foguem Tincho, Evelyn, additional, Undurraga, Manuela, additional, Cattin, Magali, additional, Makohliso, Solomzi, additional, Schönenberger, Klaus, additional, Gervaix, Alain, additional, Thiran, Jean-Philippe, additional, and Petignat, Patrick, additional

Published
2021
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47. A cross-sectional study exploring triage of human papillomavirus (HPV)-positive women by visual assessment, manual and computer-interpreted cytology, and HPV-16/18–45 genotyping in Cameroon

Author

Vassilakos, Pierre, primary, Wisniak, Ania, additional, Catarino, Rosa, additional, Tincho Foguem, Eveline, additional, Balli, Christine, additional, Saiji, Essia, additional, Tille, Jean-Christophe, additional, Kenfack, Bruno, additional, and Petignat, Patrick, additional

Published
2021
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48. Description of Maternal Morbidities Amongst 1000 Women During Pregnancy in Ambanja, Madagascar – Opportunities and Challenges of Using an mHealth System

Author

Garcia Vilaplana,Elisabeth, Petignat,Patrick, Benski,Anne-Caroline, Soaroby,Adelia, Sormani,Jessica, Vassilakos,Pierre, and Schmidt,Nicole C

Subjects
International Journal of Women's Health
Abstract

Elisabeth Garcia Vilaplana,1,2 Patrick Petignat,2 Anne-Caroline Benski,2– 4 Adelia Soaroby,4 Jessica Sormani,2 Pierre Vassilakos,2,5 Nicole C Schmidt2,6 1Faculty of Medicine, University of Geneva, Geneva, Switzerland; 2Department of Paediatrics, Gynaecology and Obstetrics, University Hospitals of Geneva, Geneva, Switzerland; 3Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA; 4Centre Medical St Damien, Ambanja, Madagascar; 5Geneva Foundation for Medical Education and Research, Geneva, Switzerland; 6Catholic University of Applied Science, Munich, GermanyCorrespondence: Nicole C SchmidtCatholic University of Applied Science, Preysingstraße 95, Munich 81667, GermanyTel +49 89 48092-8499Email nicole.schmidt@ksh-m.deBackground: The estimated burden of maternal morbidities in lower-income countries, such as Madagascar, is high. However, there is still a lack of data on maternal morbidities, in part due to an absence of standardized assessment tools. This cross-sectional study aims to report maternal morbidities among 1015 women in the district of Ambanja, Madagascar, and to describe the advantages and limitations of a mHealth system.Methods: Data were collected using the PANDA (pregnancy and newborn diagnosis assessment) system, an mHealth device that incorporates the WHO recommendations for antenatal care (ANC). Data, including personal and medical information, but also clinical data such as hypertension, anemia or HIV were collected from more than 1000 women attending ANC.Results: A total of 1015 pregnant women were recruited from January 2015 to August 2018. The average age was 24.6 years old, and most women were married (82.3%). The majority lived in urban areas and were unemployed. Prevalence of hypertension and gestational diabetes was relatively low (4% vs 2.2%). Malaria infection was diagnosed in 2.2% and HIV was diagnosed in 1.2% of pregnant women. The most common morbidity was anemia (68.4%) and the only significant factor associated was being single compared to being married (OR 1.68, 95% CI 1.05– 2.70, p-value 0.032).Discussion: The prevalence of anemia in our study population was much higher than previously reported in Sub-Saharan Africa. This finding highlights the need for regular iron supplementation during pregnancy, especially in vulnerable (eg, single) women. The PANDA mHealth system provides unique opportunities due to its standardization of ANC and creation of a digital database accessible from a distance. However, one of the main challenges was that even a mHealth system such as the PANDA remains dependent on the local procurement chain. Therefore, future studies need to access opportunities of mHealth systems to support health service delivery.Trial Registration: Registered on ISRCTN on 14th October 2015, number ISRCTN18270380. Retrospectively registered.Keywords: maternal health, maternal deaths, anemia, antenatal care

Published
2020

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