Cervical CancerHydrogel-RTNCT07904182
Hydrogel Spacer During Definitive Radiotherapy for Cervical Cancer
A study testing Absorbable Hydrogel Spacer in people with Cervical Cancer, run by Tianjin Medical University Cancer Institute and Hospital at 1 site in China.
Trial summary
This prospective, single-center study will evaluate the feasibility, spatial stability, and dosimetric effects of an absorbable hydrogel spacer placed between the cervix/vagina and rectum before definitive radiotherapy for cervical cancer. Read more about this study
- Who is it for?
- Ages 17 to 75 years, women only
- Conditions the study is for
- Cervical Cancer
- What is being tested?
- Absorbable Hydrogel Spacer
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteChina
- Study dates
- 12 Oct 2026to 30 Sep 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 17 to 75 years
- Women only
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Female participants aged 18 to 75 years.
- Pathologically confirmed cervical cancer planned for definitive external beam radiotherapy combined with brachytherapy.
- Previously untreated disease with no prior pelvic radiotherapy.
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 and considered by the investigator to be able to complete definitive radiotherapy.
- Able to undergo pelvic magnetic resonance imaging (MRI) and other imaging examinations required by the study before treatment.
- Anatomical conditions considered suitable by imaging and investigator assessment for hydrogel spacer implantation between the posterior cervix/vaginal wall and the anterior rectal wall.
- Able to understand the study, willing to participate, and able to provide written informed consent.
Who cannot join
- Prior pelvic radiotherapy or other prior radiotherapy considered likely to substantially affect dosimetric evaluation in this study.
- Pregnancy or breastfeeding.
- Active pelvic infection, fever, or other acute condition making an invasive procedure unsuitable.
- Rectovaginal fistula, obvious rectal wall invasion, severe rectal inflammation, or other conditions considered by the investigator to substantially increase the risk of rectal perforation or fistula associated with spacer implantation.
- Severe coagulation abnormality or an uncorrectable bleeding risk.
- Severe cardiac, pulmonary, hepatic, renal, or other systemic disease considered by the investigator to prevent completion of treatment or study follow-up.
- Known history of severe allergy to components of the study product.
- Any other condition that, in the investigator's judgment, makes the participant unsuitable for the study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Tianjin Medical University Cancer Institute and Hospital
Tianjin, Tianjin Municipality, 300000
Yuanjie Cao, MD, 86+18522123151
About this study
Official title: A Prospective Single-Center Study of Absorbable Hydrogel Spacer for Whole-Course Radiotherapy in Cervical Cancer: Feasibility, Spatial Stability, and Dosimetric Outcomes
This prospective, single-center study will evaluate the feasibility, spatial stability, and dosimetric effects of an absorbable hydrogel spacer placed between the cervix/vagina and rectum before definitive radiotherapy for cervical cancer. Approximately 30 participants will receive hydrogel spacer implantation before the first fraction of external beam radiotherapy (EBRT), followed by standard definitive radiotherapy including EBRT and image-guided brachytherapy (IGBT).
Serial magnetic resonance imaging (MRI) and computed tomography (CT) will be used to assess spacer position, thickness, and stability throughout treatment. Radiation doses to the rectum and other organs at risk will be evaluated across the full course of radiotherapy. The primary objective is to assess the effect of the hydrogel spacer on cumulative rectal dose while maintaining adequate target coverage. Procedure-related safety and feasibility will also be evaluated.
Read the detailed description
This is a prospective, single-center, single-arm exploratory study enrolling approximately 30 participants with cervical cancer who are scheduled to receive definitive radiotherapy. An absorbable hydrogel spacer will be implanted between the posterior cervix/vaginal wall and the anterior rectal wall before the first fraction of EBRT. The spacer procedure is performed in addition to standard oncologic treatment and does not otherwise alter the planned definitive radiotherapy or systemic therapy.
Participants will undergo longitudinal imaging to characterize the spacer throughout the course of treatment. Baseline imaging will be obtained before implantation (T0). Post-implantation MRI and planning CT will be performed at T1, followed by mid-course MRI during EBRT (T2), routine MRI before brachytherapy (T3), and follow-up MRI approximately 1 month after completion of radiotherapy (T4). Spacer thickness, volume, morphology, position, and displacement will be assessed over time.
Dosimetric analyses will evaluate the rectum and other organs at risk during both EBRT and IGBT. The primary endpoint is the cumulative rectal D2cc expressed as equivalent dose in 2-Gy fractions (EQD2) across the full course of radiotherapy. Target coverage and additional dose-volume parameters for the rectum, bladder, sigmoid colon, and small bowel will also be evaluated.
For EBRT, paired pre-spacer and post-spacer planning datasets will be used to evaluate changes in organ-at-risk dose under comparable planning conditions. Exploratory comparisons may also be performed using matched historical controls treated without hydrogel spacer implantation. Technical feasibility, procedure-related adverse events, spacer stability, and longitudinal imaging characteristics will be assessed as secondary or exploratory outcomes.
- Conditions
- Cervical Cancer
- Being tested
- Absorbable Hydrogel Spacer
- Keywords
- Cervical Cancer, Hydrogel Spacer, Absorbable Hydrogel, Radiotherapy, External Beam Radiotherapy, Brachytherapy, Image-Guided Brachytherapy, Rectal Dose, Dosimetry, Organ at Risk
- Medical subject headings
- Uterine Cervical Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Absorbable Hydrogel SpacerDevice
An absorbable hydrogel spacer will be implanted between the posterior cervix/vaginal wall and the anterior rectal wall before the first fraction of external beam radiotherapy (EBRT). The spacer is intended to increase the physical separation between the target region and the rectum during definitive radiotherapy. Participants will subsequently receive standard definitive radiotherapy, including EBRT and image-guided brachytherapy (IGBT). The position, morphology, and stability of the spacer and its dosimetric effects will be evaluated throughout the course of treatment.
| Study group | Role | What they receive |
|---|---|---|
| Hydrogel Spacer Group | Experimental | Participants will undergo implantation of an absorbable hydrogel spacer between the posterior cervix/vaginal wall and the anterior rectal wall before the first fraction of external beam radiotherapy (EBRT). Participants will subsequently receive standard definitive radiotherapy, including EBRT and image-guided brachytherapy (IGBT), according to the institutional treatment protocol. Serial MRI and CT will be performed to evaluate spacer stability and dosimetric effects throughout the course of radiotherapy. Receives: Device: Absorbable Hydrogel Spacer |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cumulative Rectal D2cc During the Full Course of Radiotherapy
Cumulative dose to the most exposed 2 cm³ of the rectum (D2cc) from external beam radiotherapy (EBRT) and all image-guided brachytherapy (IGBT) fractions, expressed as equivalent dose in 2-Gy fractions (EQD2) using an α/β ratio of 3 Gy. The cumulative rectal D2cc will be analyzed as a continuous variable.
Measured: From the start of EBRT through completion of the final IGBT fraction, approximately 7-8 weeks
Secondary outcomes (4)
Proportion of Participants With Cumulative Rectal D2cc EQD2 ≤65 Gy
Proportion of participants with cumulative rectal D2cc ≤65 Gy EQD2, calculated from EBRT and all IGBT fractions using an α/β ratio of 3 Gy.
Measured: Through completion of the final IGBT fraction, approximately 7-8 weeks
Change in Rectal D2cc Between Pre-Spacer and Post-Spacer EBRT Plans
Within-participant change in rectal D2cc between the research pre-spacer virtual EBRT plan generated using T0-CT and the clinical post-spacer EBRT plan generated using T1-CT under standardized planning conditions. The change in rectal D2cc will be reported in Gy.
Measured: From T0-CT before hydrogel implantation to T1-CT before the first EBRT fraction, approximately 1-7 days
Proportion of Participants Completing the Planned Hydrogel-Assisted Radiotherapy Workflow
Proportion of participants who successfully undergo hydrogel implantation and complete the planned EBRT and IGBT workflow without clinically meaningful treatment interruption attributable to the study procedure.
Measured: From hydrogel implantation through completion of the final IGBT fraction, approximately 7-8 weeks
Proportion of Participants With Procedure- or Device-Related Adverse Events
Proportion of participants experiencing adverse events or serious adverse events considered related to hydrogel implantation, the device, or the implantation procedure. Adverse events will be graded according to CTCAE version 5.0.
Measured: From hydrogel implantation through 12 months after completion of radiotherapy
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2026
- Study start12 Oct 2026
- Primary completion30 Sep 2027 (estimated)
- Study completion30 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cervical CancerStudies of the same condition, open and under way.
- More trials run by Tianjin Medical University Cancer Institute and HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- All enrolled participants will receive absorbable hydrogel spacer implantation before definitive radiotherapy. Exploratory dosimetric comparisons may be performed using matched historical controls who did not receive hydrogel spacer implantation; these historical controls are not an interventional study arm.
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Yuanjie Cao, MD, Principal investigator, Tianjin Medical University Cancer Institute and Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07904182
- Sponsor's protocol ID
- Hydrogel-RT-CC-2026
- Acronym
- Hydrogel-RT
- Status last verified
- Oct 2026
- First submitted
- 18 Oct 2026
- Last updated
- 29 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data sharing is not planned for this study.
Study at a glance
From the registry record, last updated by the sponsor on 29 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Single-Center Study of Absorbable Hydrogel Spacer for Whole-Course Radiotherapy in Cervical Cancer: Feasibility, Spatial Stability, and Dosimetric Outcomes
- ClinicalTrials.gov ID
- NCT07904182
- Acronym / sponsor ID
- Hydrogel-RT / Hydrogel-RT-CC-2026
- Conditions
- Cervical Cancer
- Keywords
- Cervical Cancer, Hydrogel Spacer, Absorbable Hydrogel, Radiotherapy, External Beam Radiotherapy, Brachytherapy, Image-Guided Brachytherapy, Rectal Dose
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Tianjin Medical University Cancer Institute and HospitalUniversity, hospital or other
- Study start
- 12 Oct 2026 (actual)
- Primary completion
- 30 Sep 2027 (estimated)
- Study completion
- 30 Sep 2028 (estimated)
- First posted
- 29 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective, single-center study will evaluate the feasibility, spatial stability, and dosimetric effects of an absorbable hydrogel spacer placed between the cervix/vagina and rectum before definitive radiotherapy for cervical cancer. Approximately 30 participants will receive hydrogel spacer implantation before the first fraction of external beam radiotherapy (EBRT), followed by standard definitive radiotherapy including EBRT and image-guided brachytherapy (IGBT).
Serial magnetic resonance imaging (MRI) and computed tomography (CT) will be used to assess spacer position, thickness, and stability throughout treatment. Radiation doses to the rectum and other organs at risk will be evaluated across the full course of radiotherapy. The primary objective is to assess the effect of the hydrogel spacer on cumulative rectal dose while maintaining adequate target coverage. Procedure-related safety and feasibility will also be evaluated.
Detailed description
This is a prospective, single-center, single-arm exploratory study enrolling approximately 30 participants with cervical cancer who are scheduled to receive definitive radiotherapy. An absorbable hydrogel spacer will be implanted between the posterior cervix/vaginal wall and the anterior rectal wall before the first fraction of EBRT. The spacer procedure is performed in addition to standard oncologic treatment and does not otherwise alter the planned definitive radiotherapy or systemic therapy.
Participants will undergo longitudinal imaging to characterize the spacer throughout the course of treatment. Baseline imaging will be obtained before implantation (T0). Post-implantation MRI and planning CT will be performed at T1, followed by mid-course MRI during EBRT (T2), routine MRI before brachytherapy (T3), and follow-up MRI approximately 1 month after completion of radiotherapy (T4). Spacer thickness, volume, morphology, position, and displacement will be assessed over time.
Dosimetric analyses will evaluate the rectum and other organs at risk during both EBRT and IGBT. The primary endpoint is the cumulative rectal D2cc expressed as equivalent dose in 2-Gy fractions (EQD2) across the full course of radiotherapy. Target coverage and additional dose-volume parameters for the rectum, bladder, sigmoid colon, and small bowel will also be evaluated.
For EBRT, paired pre-spacer and post-spacer planning datasets will be used to evaluate changes in organ-at-risk dose under comparable planning conditions. Exploratory comparisons may also be performed using matched historical controls treated without hydrogel spacer implantation. Technical feasibility, procedure-related adverse events, spacer stability, and longitudinal imaging characteristics will be assessed as secondary or exploratory outcomes.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- All enrolled participants will receive absorbable hydrogel spacer implantation before definitive radiotherapy. Exploratory dosimetric comparisons may be performed using matched historical controls who did not receive hydrogel spacer implantation; these historical controls are not an interventional study arm.
| Arm | Type | Receives |
|---|---|---|
| Hydrogel Spacer Group | Experimental | Device: Absorbable Hydrogel SpacerParticipants will undergo implantation of an absorbable hydrogel spacer between the posterior cervix/vaginal wall and the anterior rectal wall before the first fraction of external beam radiotherapy (EBRT). Participants will subsequently receive standard definitive radiotherapy, including EBRT and image-guided brachytherapy (IGBT), according to the institutional treatment protocol. Serial MRI and CT will be performed to evaluate spacer stability and dosimetric effects throughout the course of radiotherapy. |
Who may qualify
- Ages
- 17 to 75 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Female participants aged 18 to 75 years.
- Pathologically confirmed cervical cancer planned for definitive external beam radiotherapy combined with brachytherapy.
- Previously untreated disease with no prior pelvic radiotherapy.
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 and considered by the investigator to be able to complete definitive radiotherapy.
- Able to undergo pelvic magnetic resonance imaging (MRI) and other imaging examinations required by the study before treatment.
Key exclusion criteria (8 listed)
- Prior pelvic radiotherapy or other prior radiotherapy considered likely to substantially affect dosimetric evaluation in this study.
- Pregnancy or breastfeeding.
- Active pelvic infection, fever, or other acute condition making an invasive procedure unsuitable.
- Rectovaginal fistula, obvious rectal wall invasion, severe rectal inflammation, or other conditions considered by the investigator to substantially increase the risk of rectal perforation or fistula associated with spacer implantation.
- Severe coagulation abnormality or an uncorrectable bleeding risk.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Absorbable Hydrogel SpacerAn absorbable hydrogel spacer will be implanted between the posterior cervix/vaginal wall and the anterior rectal wall before the first fraction of external beam radiotherapy (EBRT). The spacer is intended to increase the physical separation between the target region and the rectum during definitive radiotherapy. Participants will subsequently receive standard definitive radiotherapy, including EBRT and image-guided brachytherapy (IGBT). The position, morphology, and stability of the spacer and its dosimetric effects will be evaluated throughout the course of treatment. | Device | Hydrogel Spacer Group |
Primary outcome
Cumulative Rectal D2cc During the Full Course of Radiotherapy
Time frame: From the start of EBRT through completion of the final IGBT fraction, approximately 7-8 weeks
Cumulative dose to the most exposed 2 cm³ of the rectum (D2cc) from external beam radiotherapy (EBRT) and all image-guided brachytherapy (IGBT) fractions, expressed as equivalent dose in 2-Gy fractions (EQD2) using an α/β ratio of 3 Gy. The cumulative rectal D2cc will be analyzed as a continuous variable.
4 secondary outcomes
Proportion of Participants With Cumulative Rectal D2cc EQD2 ≤65 Gy
Time frame: Through completion of the final IGBT fraction, approximately 7-8 weeks
Change in Rectal D2cc Between Pre-Spacer and Post-Spacer EBRT Plans
Time frame: From T0-CT before hydrogel implantation to T1-CT before the first EBRT fraction, approximately 1-7 days
Proportion of Participants Completing the Planned Hydrogel-Assisted Radiotherapy Workflow
Time frame: From hydrogel implantation through completion of the final IGBT fraction, approximately 7-8 weeks
Proportion of Participants With Procedure- or Device-Related Adverse Events
Time frame: From hydrogel implantation through 12 months after completion of radiotherapy
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data sharing is not planned for this study.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Yuanjie Cao, MD principal investigator
Tianjin Medical University Cancer Institute and Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Absorbable Hydrogel Spacer in people with Cervical Cancer, run by Tianjin Medical University Cancer Institute and Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Yuanjie Cao, MD (86+18522123151, cyjro325@tjmuch.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cumulative Rectal D2cc During the Full Course of Radiotherapy (time frame: From the start of EBRT through completion of the final IGBT fraction, approximately 7-8 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Oct 2026.