Clinical trial · Interventional
Rectal Spacer Hydrogel Before Radiation Therapy in Reducing Radiation Dose to the Rectum in Patients With Prostate Cancer
A Non-Randomized Phase II Study of the Reduction in Rectal V100 With the Use of Rectal Spacer Hydrogel in the Management of Intermediate Risk Prostate Cancer Treated With Combined Modality Radiation Therapy
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Why stopped (as posted): Was not meeting target enrollment; other treatment options precluded completing study
Summary
Brief summary (as posted)
This phase II trial studies the effect of rectal spacer hydrogel before radiation therapy in reducing radiation dose to the rectum in patients with prostate cancer. Rectal spacer hydrogen is a soft gel material used to create a space between the rectum and prostate during radiation treatment. The rectal spacer gel is made up of 90% water and 10% polyethylene glycol and is injected as a liquid through a needle inserted between the rectum and prostate. It stays in place for about 3 months and is naturally absorbed into the body and removed through urine in about 6 months. By pushing the prostate further from the rectum with the hydrogel, it may help spare the rectum from receiving radiation during standard of care stereotactic body radiation therapy and brachytherapy treatment.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Prostate Cancer | Malignant Prostate Neoplasm | CURATED_EXACT | 0.92 |
Interventions
Interventions (5)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Brachytherapy | Radiation | — | UNRESOLVED |
| CT simulation | Procedure | — | UNRESOLVED |
| Medical Device Usage and Evaluation | Device | — | UNRESOLVED |
| Post-implant dosimetry scan | Procedure | — | UNRESOLVED |
| Stereotactic body radiation therapy | Procedure | — | UNRESOLVED |
Design
Arms and outcomes
Arms (1)
- type
- EXPERIMENTAL
- label
- Patients with prostate cancer
- description
- Patients undergo hydrogel rectal spacer placement on day 1. Within 2 weeks (+/-1 week) after Rectal Spacer placement, patients will be scheduled for CT simulation for external beam treatment planning. Patients will begin the SBRT of 24Gy in 5 fractions within 2 weeks (+/-1 week) from the simulation date. Within 4 weeks (+/-1 week) of last day of SBRT, patients undergo brachytherapy. Patient will return for post-implant CT-based dosimetry analysis 4 weeks (+/- 1 week) post brachytherapy,
- interventionNames
- Device: Medical Device Usage and Evaluation
- Procedure: CT simulation
- Procedure: Stereotactic body radiation therapy
- Radiation: Brachytherapy
- Procedure: Post-implant dosimetry scan
Primary outcomes (1)
- measure
- The proportion of participants that achieve V100rectum < 0.75 cc
- timeFrame
- At 1 month post-brachytherapy (at about 2 months)
- description
- Volume of the rectum receiving at least 100% of the prescribed dose (V100rectum) \< 0.75 cc rate will be estimated as the proportion of patients that achieve V100rectum \< 0.75 cc at the post-implant dosimetry computed tomography scan 1 month following brachytherapy along with a corresponding two-sided 90% confidence interval using the methods and software introduced by Koyama and Chen which accounts for the group sequential nature of the design
Eligibility
Eligibility (as posted)
- Sex
- Male
- Minimum age
- 18 Years
Show eligibility criteria text
Inclusion Criteria: * Histologically/biopsy confirmed adenocarcinoma of prostate within 1 year of registration * Disease confined to the prostate. Prostate volume must be \<150cc confirmed by pelvic CT (with or without contrast) or pelvic/prostate MRI (with or without contrast) +/- ultrasound, within 8 months of signing research consent * Age \>18 * Patients deemed medically suitable to undergo rectal spacer placement, external beam radiotherapy and brachytherapy at the discretion of the radiation oncologist, urologist, medical oncologist and/or internist. * ECOG score of 0-2. * One or more of the following risk factors for intermediate risk prostate cancer; T2b or T2c clinical stage, GS 7 (either 3+4 or 4+3), PSA 10-20. * Ability to understand and the willingness to sign a written informed consent. * PSA result within 6 months of simulation Exclusion Criteria: * Patients with disease not confined to the prostate based on imaging, biopsy, or clinical exam * Patients with a prostate size \> 100 cc based on computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound measurements * Patients who have undergone previous rectal, bowel, bladder, or prostate surgeries in the past * Patients with previous treatments for their prostate cancer or that are currently receiving any other experimental therapies * Patients who have undergone prior pelvic radiotherapy * Patients with high risk prostate cancer that have any of the following risk factors; GS \>= 8, PSA \> 20, clinical or imaging stage T3a or higher * Patients receiving antiandrogen therapy (ADT) * Patients with any prior active or treated genitourinary malignancy
References
Publications (1)
- BACKGROUNDNehlsen AD, Sindhu KK, Moshier E, Sfakianos JP, Stock RG. The impact of a rectal hydrogel spacer on dosimetric and toxicity outcomes among patients undergoing combination therapy with external beam radiotherapy and low-dose-rate brachytherapy. Brachytherapy. 2021 Mar-Apr;20(2):296-301. doi: 10.1016/j.brachy.2020.09.018. Epub 2020 Nov 13. PMID 33199175