Introduction Different approaches to screening and treatment of cervical precancer Anatomical considerations

Anatomical considerations Gross anatomy of female genital organs, External genitalia Internal genital organs Gross anatomy of the cervix Cervical epithelium Squamous epithelium Columnar epithelium Squamocolumnar junction (SCJ)

Physiological changes of the cervical epithelium

Ectropion Squamous metaplasia Transformation zone of the cervix Changes induced by pregnancy Atrophic changes Congenital transformation zone (CTZ)

Neoplastic changes of the cervical epithelium

Genesis of cervical cancer – Role of HPV HPV structure and types Genesis of precancerous lesions and cervical cancer Cervical intraepithelial neoplasia (CIN) Adenocarcinoma in situ (AIS) Cervical cancers

HPV tests – Variation between tests Instruments, consumables, and setup required

for collection of samples for HPV testing (provider-collected) for self-collection of samples for HPV testing

Procedure to collect samples for HPV testing

Sample collected by a health provider Counselling of a woman undergoing HPV testing History taking Preparation for sample collection for HPV testing Steps for inspection of the external genitalia Steps for insertion of the speculum and exposure of the cervix Steps for collection of cervical samples Steps for self-collection of samples Storage of the samples after collection, and transportation to the laboratory

Interpretation of HPV test results Management of women with a positive HPV test result

Management of women with a positive HPV test result The different strategies Triage with cytology Triage with VIA Triage with colposcopy

Treatment of cervical intraepithelial neoplasia – principles Steps to determine eligibility for ablative treatment

Criteria used to determine eligibility for ablative treatment Steps to determine eligibility for ablative treatment

Role of Lugol’s iodine in identifying the transformation zone for treatment

Role of Lugol’s iodine in identifying the transformation zone for treatment Steps for applying Lugol’s iodine to the cervix Pre-treatment assessment

Treatment by cryotherapy

Principles Cryosurgical unit Ancillary instruments and consumables Steps Side-effects and complications Post-treatment advice and follow-up Video

Treatment by thermal ablation

Principles The benchtop model The battery-operated model Complications Video

Using an HPV test as the test of cure in women treated for cervical abnormalities or cervical intraepithelial neoplasia (CIN) Infection prevention

Standard procedures for protection from infection Essential steps for infection prevention in a cervical cancer screening clinic Preparation of 0.5% chlorine solution

Case studies

VIA triage outcome (applicable in screen-and-treat setting only) – negative cases VIA triage outcome – positive cases VIA triage outcome – suspicious of cancer cases

Foreword Acknowledgement Authors Suggested citation Copyright

Home / Training / Manuals / Using HPV tests for cervical cancer screening and managing HPV-positive women – a practical online guide / Learning

Using HPV tests for cervical cancer screening and managing HPV-positive women – a practical online guide

Filter by language: English / Français / Español

Treatment by cryotherapy – Steps

Click on the pictures to magnify and display the legends

Counsel the woman, and obtain informed consent.
Re-evaluate the lesion (by performing colposcopy or with naked-eye examination after application of 3–5% acetic acid or with a magnifying device after application of 3–5% acetic acid) and ensure that:

the squamocolumnar junction (SCJ) is fully visible and is on the ectocervix or at the external os;
if there is a visible lesion, it is on the ectocervix without any extension to the endocervix or to the vagina;
if there is a visible lesion, it does not occupy more than 75% of the ectocervix;
the transformation zone or the lesion (when a lesion is present) can be fully covered by the tip of the largest cryotherapy probe;
there is no suspicion of invasive cancer (on naked-eye examination or on colposcopy or on earlier cytology or histopathology reports); and
there is no suspicion of adenocarcinoma in situ (e.g. a cytology report suggesting abnormal glandular cells).

No anaesthesia is required.
If required, obtain a punch biopsy from the cervix. Stop the bleeding with Monsel’s paste or silver nitrate or pressure before proceeding to the next steps.
Select a probe with a tip of the appropriate diameter that will cover the transformation zone or the lesion completely. Attach the probe to the handle grip (cryogun).
Connect the valve with the pressure gauge to the gas cylinder. The pressure of the gas cylinder should be 40–70 kg/cm2 when the gas is flowing (indicator in the green zone).
Wipe the cryotip with saline to ensure adequate thermal contact.
Apply the probe tip firmly to the cervix, with the centre of the tip on the external os.
Check that the vaginal walls are not touching the probe tip.
Press the trigger on the handgrip so that gas starts flowing; start the timer.
Check for the formation of ice at the tip of the probe.

Release the trigger after 3 minutes, when you will see an ice ball formed over the cervix extending 4–5 mm beyond the edge of the tip.
If the ice ball has formed adequately, the probe tip will remain stuck to the cervix.

Wait for 5 minutes for thawing, when the ice will melt and the probe may detach from the cervix.
Reapply the probe at the same place as before, and freeze the cervix for another 3 minutes.
Always follow the double-freeze method of a 3–5–3 cycle (3 minutes of freezing, 5 minutes of thawing, and 3 minutes of freezing).
Release the trigger and wait until the ice melts and the probe detaches from the cervix on its own.
The cervix will have a white crater, which indicates that the cervix is properly frozen.

Remove the speculum gently.
Ask the woman to continue lying down for 5 minutes before letting her get up.
Counsel the woman, and give appropriate follow-up advice.

For additional information, please refer to WHO technical specifications: cryosurgical equipment for the treatment of precancerous cervical lesions and prevention of cervical cancer.

IARC, 150 Cours Albert Thomas, 69372 Lyon CEDEX 08, France - Tel: +33 (0)4 72 73 84 85 - Fax: +33 (0)4 72 73 85 75
© IARC 2024 - All Rights Reserved.