NCT06995053 · Jonsson Comprehensive Cancer Center
Computed Tomography-Guided Stereotactic Body Radiation Therapy With Intrafraction Motion Monitoring for the Treatment of Localized Prostate Cancer, ILLUSION Trial
(ILLUSION)
What this study is about
This clinical trial studies the side effects of computed tomography (CT)-guided stereotactic body radiation therapy (SBRT) with intrafraction motion monitoring and to see how well it works in treating patients with prostate cancer that has not spread to other parts of the body (localized).
View original scientific description
This clinical trial studies the side effects of computed tomography (CT)-guided stereotactic body radiation therapy (SBRT) with intrafraction motion monitoring and to see how well it works in treating patients with prostate cancer that has not spread to other parts of the body (localized). In CT-guided SBRT, x-ray-based imaging and cone-beam CTs are used to define and localize the area to be treated with SBRT. SBRT is a type of external radiation therapy that uses special equipment to position a patient and precisely deliver radiation to tumors in the body (except the brain). The total dose of radiation is divided into smaller doses given over several days. This type of radiation therapy helps spare normal tissue. A recent randomized trial showed that while SBRT is associated with less urinary incontinence and erectile dysfunction than complete surgical removal of the prostate, there are more urinary irritative side effects and more bowel side effects than with surgery. One source of uncertainty in SBRT that may contribute to genitourinary (GU) and gastrointestinal (GI) side effects is the necessity of treating a "margin" of volume around the prostate to account for its movement during SBRT. Intrafraction motion monitoring is any technique or system designed to track the movement of the body and target during fractions of external beam radiation to keep the beam on target. This allows for the patient to be repositioned, if needed, to ensure delivery of the SBRT to only the planned treatment area. CT-guided SBRT with intrafraction motion monitoring may lower GU and GI side effects by allowing tighter margins, as has been demonstrated with magnetic resonance imaging (MRI)-guided SBRT.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Histologically confirmed, clinically localized adenocarcinoma of the prostate
- No evidence of metastatic disease in lymph nodes above the bifurcation of the renal arteries, or in bones or visceral organs (nodal disease identified on a prostate-specific membrane antigen \[PSMA\] positron emission tomography \[PET\]/CT scan below the bifurcation of the renal arteries are amenable)
- Staging workup as recommended by the National Comprehensive Cancer Network (NCCN) on the basis of risk grouping
- Advanced imaging studies (i.e. PSMA PET/CT and fluciclovine PET/CT scan) can supplant a bone scan if performed first
- Written informed consent obtained from participant or participant's legal representative and ability for participant to comply with the requirements of the study
Exclusion criteria
- Patients with neuroendocrine or small cell carcinoma of the prostate
- Patients with any evidence of distant metastases except that evidence of lymphadenopathy below the level of the renal arteries can be deemed locoregional per the discretion of the investigator
- Prior whole gland cryosurgery, high-intensity focused ultrasound (HIFU) or brachytherapy of the prostate
- Prior pelvic radiotherapy
- History of Crohn's Disease, ulcerative colitis, or ataxia telangiectasia
- Presence of a condition or abnormality that in the opinion of the investigator would compromise the safety of the participant or the quality of the data
Where
- Los Angeles, California
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Nov 10, 2025 · Source of record for eligibility and locations