Recruiting
Phase 2

Stereotactic Radiotherapy

Sponsor:

University of Texas Southwestern Medical Center

Code:

NCT07313241

Conditions

Prostate Cancer

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Prostate Fossa Radiotherapy

Pelvic nodal Radiotherapy

Androgen Deprivation Therapy (ADT)

Study Details

Brief summary:

This Phase II, single arm study evaluates a PSA-response-adapted approach to salvage radiotherapy after radical prostatectomy for prostate cancer. All participants will receive hypo-fractionated stereotactic radiotherapy to the prostate fossa. At 5 weeks, biochemical response will be assessed. responders will proceed to observation, while non responders will receive sequential pelvic nodal radiotherapy and 4 months of androgen deprivation therapy (ADT). The study aims to determine whether this response base approach achieves non inferior 2 year freedom from progression compared with historical outcomes using routine pelvic nodal radiotherapy and ADT in all patients.

Conditions

Prostate Cancer

Study ID

NCT07313241

Start date

Nov 14, 2025

Status verified date

Jun, 2026

Completion date

Nov 14, 2030

Anticipated

Primary completion date

Nov 14, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Male

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Men aged ≥18 years with histologically confirmed prostate adenocarcinoma treated with prostatectomy in the localized setting within 10 years, with post-operative PSA (persistent or rising) of ≥0.05ng/mL.
  • Radical prostatectomy ≥4 months prior to enrollment without nodal involvement (pN0 or pNx)
  • Performance status ECOG 0-2
  • No definite evidence of regional or distant metastatic disease by at least pelvic imaging within 90 days of registration. Equivocal findings are allowed at investigator discretion. Imaging is specified as follows:

  • PSA>=0.2ng/mL: positron emission tomography (PET) with FDA-approved advanced imaging agent for prostate cancer (e.g. PSMA) required.
  • PSA <0.2 n/gm: PET with above noted agents OR conventional CT or MRI at investigator discretion.
  • All sexually active men must agree to use adequate contraception for the duration of study therapies and a period of 60 days thereafter. Should a female partner of a trial participant become pregnant or suspect she is pregnant while the subject is participating in this study, the patient should inform his treating physician immediately.
  • Ability to understand and the willingness to sign a written informed consent.

Exclusion Criteria:

  • Prior androgen deprivation therapy (ADT) > 3 months OR anti-androgen therapy (AAT) of > 30 days. For shorter courses of either, at least 30 day "wash out" period is required with confirmation of resolved castration of testosterone to >50ng/mL.
  • Ongoing testosterone replacement therapy (TRT) with refusal to discontinue (must be stopped with demonstration of detectable PSA ≥0.05ng/mL and non-castrate testosterone >50ng/mL after 14 days of TRT cessation)
  • Prior pelvic radiotherapy
  • Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements.
  • History of bladder neck or urethral stricture requiring procedural intervention.
  • Patients with a prior or concurrent malignancy whose natural history or treatment has the potential to actively interfere with the safety or efficacy assessments of this study in the investigator's view.
  • Active inflammatory bowel disease requiring recurring systemic or steroid/enema therapy

Study Design

Enrollment

68 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Single Arm: PSA Response Adapted Salvage Radiotherapy

All participants initially receive prostate fossa radiotherapy (RT) using stereotactic ultra-hypofractionated dosing (32.5 Gy in 5 fractions over 2-4 weeks) delivered via the Ethos™ online adaptive platform.

At approximately 5 weeks post-RT initiation, PSA response is assessed:

  • Responders: Patients with PSA <0.05 ng/mL or a decrease of ≥0.2 ng/mL compared to pre-RT PSA will undergo observation without further immediate therapy.
  • Non-Responders: Patients not meeting response criteria will receive sequential pelvic nodal RT (25 Gy in 5 fractions over ≤4 weeks) plus androgen deprivation therapy (ADT) for 4 months. Pelvic nodal RT begins within 14 days after response assessment. ADT (GnRH agonists/antagonists, e.g., leuprolide, goserelin, degarelix) will be started before or within 14 days of pelvic nodal RT initiation.

Interventions

Prostate Fossa Radiotherapy

Stereotactic ultra hypofractionanted radiotherapy delivered to the prostate fossa using the Ethos online adaptive platform. Total dose of 32.5 Gy administered in 5 fractions over 2-4 weeks.

Pelvic nodal Radiotherapy

Sequential pelvic nodal radiotherapy delivered only to PSA non responders. Dose of 25 Gy given in 5 fractions over 4 weeks using the same stereotactic technique as prostate fossa RT.

Androgen Deprivation Therapy (ADT)

GnRH agonist or antagonist (leuprolide, goserelin, degarelix) administered as per institutional standard. Therapy duration is 4 months, starting before or within 14 days of pelvic nodal RT initiation.

Primary outcome measure

  • Freedom from failure [ Time Frame: 2 years from end of radiotherapy ]

Central Contacts and Locations

Central contacts

Sarah Neufeld, MS

214-645-8525sarah.hardee@utsouthwestern.edu

Locations

UT Southwestern Medical Center-Dallas

Recruiting

Dallas, Texas, United States, 75390

Contacts

Sarah Neufeld, MS

Sarah.Neufeld@utsouthwestern.edu

More Information

Sponsor

University of Texas Southwestern Medical Center

Last update posted

Jun 30, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Texas Southwestern Medical Center on 2026-06-30.