NCT06542757 · NYU Langone Health
Evaluation of Tumor Control Based on Serial Multiparametric MRI and Post-Treatment Biopsies For Patients Treated With Dose Intensification to the Dominant Intra-Prostatic Lesion (DIL) Using Ultra-Hypofractionated, MR-Guided Radiotherapy
What this study is about
The purpose of this study is to assess the impact of this MR-guided radiotherapy on tumor control of the dominant intraprostatic lesion among patients with intermediate risk prostate cancer.
View original scientific description
The purpose of this study is to assess the impact of this MR-guided radiotherapy on tumor control of the dominant intraprostatic lesion among patients with intermediate risk prostate cancer. This study of Radiotherapy to the Prostate and Dominant Lesion Using Ultra-Hypofractionated, MR-adaptive Radiation Therapy aims to evaluate tumor control after definitive ultra-hypofractionated external beam radiation therapy (including a simultaneously delivered high-dose boost to a dominant lesion as detected on prostate magnetic resonance imaging (MRI)) in patients with intermediate-risk prostate cancer. This will incorporate the use of multiparametric MRI for target segmentation and the use of the MR-linac with adaptive radiation planning to treat the prostate gland, incorporating a dose boost to the dominant intraprostatic lesion (DIL) that is visible on T2-weighted and diffusion-weighted imaging and de-escalation of dose to the remainder of the prostate.
Interventions
RADIATION
1.5 T Elekta Unity MR-Linac system
Patients will receive 9 Gy/fraction (45 Gy total) for five fractions to the DIL, while the remainder of the prostate will be treated to 30 Gy in 5 fractions.
DEVICE
Hydrogel rectal spacer (SpaceOAR)
A rectal spacer will be placed one week prior to simulation to achieve a separation of approximately 1 cm between the prostate and anterior rectal wall to further minimize rectal toxicity in these patients. The hydrogel will remain in the body for about 12 weeks.
Primary outcome measures
Negative biopsy rate 24 months post-treatment
Time frame: 24 months post-treatment
Outcome measure will be assessed via repeat biopsy of the dominant lesion as seen on mp-MRI
Serious toxicity rate 24 months post-treatment
Time frame: 24 months post-treatment
Outcome measure will be assessed using NCI CTCAE v5.0 for gastrointestinal and genitourinary toxicity.
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
- Intermediate-risk prostate cancer patients will be eligible for this study. Risk groups will be assigned as per National Comprehensive Cancer Network (NCCN) guidelines. Intermediate-risk patients will be defined as:
- PSA 10-20 ng/ml or
- Gleason score = 7 or
- Clinical stage T2b/T2c (T2b: the tumor has spread to more than one-half of one side of the prostate, but not to both sides. T2c: the cancer has invaded both sides of the prostate)
- Karnofsky Performance Status (KPS) \> 80
- Prostate size \< 90 cc
- Presence of a T2-visible prostatic lesion with maximum dimension of ≥ 0.5 cm and no more than two additional disease foci with a documented Prostate Imaging Reporting and Data System (PIRADS) 4-5 lesion
- MRI findings: Lesion may contact the capsular edge, possible extracapsular extension (ECE) permitted
- International Prostate Symptom Score \< 18
- Satisfy all MRI screening criteria and be willing to fill out the standard MRI screening form
Exclusion criteria
- Gleason score \>7
- PSA \>20 ng/mL
- Prior or concurrent androgen deprivation therapy for prostate cancer
- MRI findings: suspicious for/probable ECE
- MRI findings: \>2 disease foci identifiable
- Evidence of metastatic disease on bone scan or MRI/CT
- MRI ineligibility due to: the presence of a cardiac pacemaker, defibrillator, or other implanted metallic or electronic device which is considered MR unsafe; severe claustrophobia; inability to lie flat for the duration of the study; etc.
- Metallic implant or device in the pelvis that might distort the local magnetic field and compromise quality of mp-MRI
- Lateral pelvic separation greater than 50 cm and/or anterior-posterior separation greater than 35 cm which are incompatible with MR for Calculating ATtenuation (MRCAT) reconstruction
- Contra-indications to receiving gadolinium contrast
- Pelvic or Prostate MRI or CT (MRI preferred) evidence of radiographic T3, T4, or N1 disease
- Prior history of transurethral resection of the prostate
- Prior history of urethral stricture
- Prior history of pelvic irradiation
- History of inflammatory bowel disease
- Unable to give informed consent
- Unable to complete quality of life questionnaires
- Abnormal complete blood count, including any of the following:
- Platelet count less than 75,000/ml
- Hb level less than 10 gm/dl
- White blood cell (WBC) less than 3.5/ml
- Abnormal renal function tests (creatinine \> 1.5)
Where
- New York, New York
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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.
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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.
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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.
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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 Mar 11, 2026 · Source of record for eligibility and locations