Thermal Ablation (Hot Probe) of Cervical Pre-Cancer Lesions

This Sexual and Reproductive Health and Rights (STARS) - Cervical Cancer Screening and Treatment skills module allows nurses, midwives, clinical officers, and medical officers to become confident and competent in performing thermal ablation of cervical pre-cancer lesions as part of cervical cancer screening and treatment procedures performed in primary health care facilities and mobile units in resource-constrained settings.

Learning Objectives[edit | edit source]

By the end of this module, learners will be able to perform thermal ablation following the correct steps for the MedGyn MTA-100 Thermal Ablation System which has a ("hot") probe shaft and heating tip that is inserted and removed while heated.

Materials and Equipment[edit | edit source]

Supplies[edit | edit source]

• Android Phone with Thermocoagulator Simulator Mobile App
• Pen

Gynecologic Simulator[edit | edit source]

The Gynecologic Simulator, Vaginal Canal, and VIA Positive Cervix will be used in this skills module.

Thermocoagulator Simulator[edit | edit source]

The MedGyn MTA-100 Thermal Ablation System is designed with a ("hot") probe shaft with heating tip that is inserted and removed heated which presents a potential risk of thermal injury to the patient and practitioner.

The Thermocoagulator Simulator with a hot probe uses a mobile app, cardboard device, and 19.0 mm and 25.0 mm diameter flat probes to simulate the thermal ablation procedure.

The Thermocoagulator Simulator also has an innovative augmented feedback feature to alert the user if the heated probe shaft or tip touches the vaginal sidewalls of the Gynecologic Simulator during probe insertion, thermal ablation, and probe removal.

Training Logbook[edit | edit source]

Please print out the Training Logbook below and write your name and date of training at the bottom of the Training Logbook page.

Training Logbook - Thermal Ablation (Hot Probe) of Cervical Pre-Cancer Lesions^[1][2]

#	Step	Check box if step was completed
1	Wash hands thoroughly and air dry them
2	Put on gloves
3	Position the light source so that the cervix can be visualized clearly
4	On the VIA Positive Cervix in the Gynecologic Simulator, identify theː* Squamocolumnar Junction Limits of the lesion Transitional Zone and area to treat
5	Photograph the pre-treatment cervix on a cellphone*
6	Select a probe of appropriate size to cover the cervix
7	Apply the probe on the area of the cervix to be treated
8	Ensure that the probe does not contact the vaginal wall during insertion*
9	Ensure that the probe does not contact the vaginal wall during thermal ablation*
10	Remove the probe gently taking care not to touch the vulva or vagina with the probe to avoid unnecessary burns*
11	Check if the entire Transitional Zone has been treated
12	If not, then repeat the procedure so as to treat the entire Transitional Zone including the lesion on the ectocervix (1–5 overlapping applications can be used)
13	For repeated procedures, ensure that the probe does not contact the vaginal wall during insertion*
14	For repeated procedures, ensure that the probe does not contact the vaginal wall during thermal ablation*
15	Remove the probe gently taking care not to touch the vulva or vagina with the probe to avoid unnecessary burns*
16	Photograph the post-treatment cervix on a cellphone*
17	Remove gloves
18	Wash hands thoroughly with soap and water and air dry them
19	Complete the documentation to record the treatment[3] in the space on the rightː* Draw two concentric circles. The outer circle represents the boundary of the cervix, and the inner circle represents the external os. Divide the circle into four quadrants with two perpendicular lines. Draw the location of the squamocolumnar junction with a dotted line. Draw the acetowhite lesions as a continuous line. Draw the treatment area as a shaded area, showing its position in relation to the quadrants and the external os.

*These checklist items must have been completed by the learner to pass this module.

Learner's Nameː

Evaluator's Nameː

Date of Trainingː

Thermal Ablation (Hot Probe) Step By Step[edit | edit source]

*The highlighted steps are considered as critical and with an asterix (̈*) are considered as critical.^[1][2]

• Check that instruments, supplies and light source are available and ready to use.^[1][2]
• Check that the Thermocoagulator Simulator, Thermocoagulator Simulator Mobile App, Gynecologic Simulator and VIA Positive Cervix are ready for use.*
• Wash hands thoroughly with soap and water and air dry them.
• Put on gloves.
• Ask a colleague to observe you and fill out the Training Logbook checklist.

• Open the videocamera function on the smartphone camera.
• Turn on the flash.
• Move the smartphone light source so that the cervix can be visualized clearly.

On the VIA Positive Cervix, identify:*^[1][2]

1. Squamocolumnar Junction
2. Limits of the lesion
3. Transitional Zone and area to treat

• Press on the back button twice on the smartphone to return to the main screen
• Open the Thermocoagulator Simulator Mobile App and press on the "Take Pre-Treatment Photo" button which activates the smartphone's camera.
• Turn on the camera flash.
• Photograph the cervix pre-treatment.
• Press on the back button twice on the smartphone to return to the main screen of the Thermocoagulator Simulator Mobile App.

• Select a hot probe of appropriate size (19.0 mm or 25.0 mm) to cover the cervix.
• Connect the probe to the Thermocoagulator Simulator.
• Cut a small length of small gauge wire.
• Loop and twist together the two ends of the small gauge wire around the aluminum foil covering the proximal probe shaft of the Thermocoagulator Simulator.
• Attach one alligator clip to the wire loop around the proximal probe shaft.
• Wind this alligator clip down the front of the Thermocoagulator Simulator and around the handle of the Thermocoagulator Simulator.
• Tape a section of the alligator clip that winds around the handle of the Thermocoagulator Simulator.
• Attach a second alligator clip to the free end of the alligator clip attached to the wire loop around the proximal probe shaft.

• Connect the alligator clip (attached to the exposed wire of the red insulated end of the buzzer) of the Augmented Feedback Circuit to the exposed aluminum foil of the Vaginal Canal.
• Connect the alligator clip from the Thermocoagulator Simulator to the other (unused) lead of a 9 V battery.

• In the main screen of the Thermocoagulator Simulator Mobile App, press on the "Run Simulation" button.
• Turn on the Thermocoagulator Simulator by pressing the ON/OFF button once.
• The lights on the device will turn on and the tip will begin heating to 100 degrees Celsius.
• The device will beep when it is ready for use.

• Apply the Thermocoagulator Simulator probe on the area of the cervix to be treated.*^[1][2]
• Make sure that the probe does not touch the vaginal sidewalls.* The buzzer will alarm if the heated probe contacts the vaginal sidewalls.

• When the probe has been placed against the tissue needing treatment, press the button to start the procedure indicated by a beep and flashing interval light.
• A long beep will indicate the end of the thermal ablation procedure, the blue lights will turn off, and the smartphone's white illumination light will turn off.
• Make sure that the probe is not touching the vaginal sidewalls during the entire treatment cycle.* The buzzer will alarm if the heated probe contacts the vaginal sidewalls.

• Remove the probe gently taking care not to touch the vulva or vagina with the probe to avoid unnecessary burns.*^[1] The buzzer will alarm if the heated probe contacts the vaginal sidewalls.
• Turn off the Thermocoagulator Simulator by pressing the ON/OFF button once.
• Verify that the green light in the center of the ON/OFF button is off.
• Press on the back button once on your smartphone to return to the main screen of the Thermocoagulator Simulator Mobile App.
• Remove probe from the treatment area.

• Repeat Step 6 and check if the entire Transitional Zone has been treated.^[1][2]
• If not, then repeat Steps 7-9 of the procedure so as to treat the entire Transitional Zone including the lesion on the ectocervix (1–5 overlapping applications can be used).
• Once the entire Transitional Zone has been treated, press the back button on your smartphone to return to the main screen of the Thermocoagulator Simulator Mobile App.
• Remove probe from the treatment area.

• Once the entire Transitional Zone has been treated and after the heated probe has been removed from the treatment area, disconnect the alligator clips from the aluminum foil of the Vaginal Canal with Augmented Feedback and the Thermocoagulator Simulator.

• Press on the "Take Post-Treatment Photo" button in the Thermocoagulator Simulator Mobile App.
• Turn on the camera flash.
• Photograph the cervix post-treatment.
• Press on the back button twice on the smartphone to return to the main screen of the smartphone.

• Power off the smartphone to minimize battery usage.
• Dissemble the Thermocoagulator Simulator for simulated cleaning and disinfection in accordance with the manufacturer's instructions.
• Remove gloves.^[1][2]
• Wash hands thoroughly with soap and water and dry with clean, dry cloth or air dry.

• Complete the documentation to record the treatment.*^[1][2]
• Draw a map of the cervix and the treated area for Step #19 in the Training Logbook using the nomenclature of the International Federation of Cervical Pathology and Colposcopy (2011 IFCPC nomenclature).^[3]
  • Draw two concentric circles.
  • The outer circle represents the boundary of the cervix, and the inner circle represents the external os.
  • Divide the circle into four quadrants with two perpendicular lines.
  • Draw the location of the squamocolumnar junction with a dotted line.
  • Draw the acetowhite lesions as a continuous line.
  • Draw the treatment area as a shaded area, showing its position in relation to the quadrants and the external os.

Resources[edit | edit source]

Sections of the STARS - Cervical Cancer Screening and Treatment module are copied or adapted from: Training of health staff in VIA, HPV detection test and cryotherapy - Trainees' handbook. New Delhi: World Health Organization, Regional Office for South-East Asia; 2017. Licence: CC-BY-NC-SA-3.0 IGO; and Training of health staff in VIA, HPV detection test and cryotherapy - Facilitators' guide. New Delhi: World Health Organization, Regional Office for South-East Asia; 2017. Licence: CC-BY-NC-SA-3.0 IGO. The World Health Organization (WHO) is not responsible for the content or accuracy of any translation. The original English edition shall be the binding and authentic edition.