Prostate CancerPhase 3VORTEXNCT07293585
Vascular Optimized Radiotherapy Tuned to Critical Structures for Erectile Function Using High-Precision X-Ray Treatment
A Phase 3 study testing Neurovascular sparing stereotactic body radiation therapy in people with Prostate Cancer, run by Jonsson Comprehensive Cancer Center at 1 site in United States.
Trial summary
With people living longer after being treated for prostate cancer, quality of life has become a concern when considering the treatment plan. Sometimes after radiation therapy, patients may experience problems that affect the urinary and bowel systems, along with sexual function. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer
- What is being tested?
- Neurovascular sparing stereotactic body radiation therapy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Dec 2025to 16 Dec 2036
- Phase
- Phase 3
- 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 18 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18.
- Histologically confirmed, clinically localized adenocarcinoma of the prostate.
- Staging workup as recommended by the National Comprehensive Cancer Network (NCCN) on the basis of risk grouping.
- Advanced imaging studies (i.e. prostate-specific membrane antigen [PSMA] positron emission tomography [PET]/CT and fluciclovine PET/CT scan) can supplant a bone scan if performed first.
- 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 PSMA PET/CT scan below the bifurcation of the renal arteries is allowable).
- Eastern Cooperative Oncology Group (ECOG) performance status ≤2.
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- Ability to undergo magnetic resonance angiography (MRA) of the pelvis.
- No indication for urgent or emergent radiation.
- Written informed consent obtained from participant or participant's legal representative and ability for participant to comply with the requirements of the study.
Who cannot join
- 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.
- Evidence of intraprostatic lesion by biopsy, MRI, or PSMA PET/CT within the middle third, or both lateral thirds of the prostate gland.
- History of whole-gland cryosurgery, high-intensity focused ultrasound (HIFU), brachytherapy, or other ablative treatments of the whole prostate.
- Prior pelvic radiotherapy.
- History of Crohn's disease, ulcerative colitis, or ataxia telangiectasia.
- Penile prosthesis or implant present prior to treatment.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of California at Los Angeles
Los Angeles, California, 90045
Christy Palodichuk, 310-794-2971, cpalodichuk@mednet.ucla.edu
Care Felix, 310-825-9771, cfelix@mednet.ucla.edu
About this study
With people living longer after being treated for prostate cancer, quality of life has become a concern when considering the treatment plan. Sometimes after radiation therapy, patients may experience problems that affect the urinary and bowel systems, along with sexual function.
Stereotactic body radiotherapy (SBRT) is a type of radiation technique that delivers five high doses of radiation. At University of California at Los Angeles (UCLA), we have the option to administer SBRT in both our CT-guided and MRI-guided radiation machines.
Read more
This trial aims to determine the most effective method for protecting the nerves and blood vessels essential for erectile function, utilizing a technique known as neurovascular sparing.
This technique uses images (i.e., MRI) to map the neurovascular bundles of nerves and blood vessels, which are crucial for erectile function. "Adapting" the radiotherapy treatment for each of these five treatment sessions could enable a more precise delivery of your radiation treatment that is customized based on your internal anatomy immediately before the treatment starts. This is also a standard and low-risk intervention used in many different types of cancer. However, it is a very labor-intensive and time-consuming procedure that requires a team of experts to work together before each of your radiotherapy sessions. We are unsure if the increased complexity associated with this adaptive treatment reduces side effects.
Read the detailed description
The mechanism implicated in sexual function decline following radiotherapy involves injury to vascular structures surrounding the prostate which are critical for normal erectile function, namely the corpora cavernosa, internal pudendal arteries, and neurovascular bundles. These structures are all in close proximity to the prostate gland and are often included at least partially within the planning target volume margin of treatment plans. As noted above, these planning target volume (PTV) expansions were historically large due to the need to ensure adequate coverage of the target volume to achieve disease control although this likely came at the cost of higher rates of treatment-related toxicity. With enhanced technology for target visualization and intra-fraction motion management, it is technically feasible to reduce margins and spare surrounding normal tissue from receiving the full prescription dose while still treating the target volume with high confidence.
Beyond reducing the isometric PTV expansion due to increased precision in radiation delivery with modern techniques, however, it is now technically feasible to crop out these sensitive Organs-at-risk (OARs) from the final PTV volume in order to further spare them from receiving excess dose. This process, referred to as neurovascular-sparing (NV-sparing), involves the fusion of an MRI and/or MR angiogram to standard radiation planning images to allow accurate contouring of the internal pudendal arteries and neurovascular bundles so that these can be intentionally spared. Daily online adaptive replanning may also play a role in ensuring appropriate coverage of the target volume and sparing of OARs as intended by the treatment plan. To date, no investigations have reported on the clinical or dosimetric outcomes of patients treated with an NV approach in conjunction with these other methods. Furthermore, specific dose constraints for these structures are largely unknown due to the lack of empiric evidence to guide selection.
- Conditions
- Prostate Cancer
- Being tested
- Neurovascular sparing stereotactic body radiation therapy
- Keywords
- sexual function
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Neurovascular sparing stereotactic body radiation therapyRadiation
Use of adaptive radiotherapy
| Study group | Role | What they receive |
|---|---|---|
| Arm 1 non-adaptive SBRT | Active comparator | Patients undergo MRI or CT-guided SBRT without daily plan adaptation once every other day or on consecutive days if necessary, for a total of 5 treatments over 18 days in the absence of disease progression or unacceptable toxicity. Additionally, patients undergo MRI and CT during screening and blood sample collection throughout the trial. Receives: Radiation: Neurovascular sparing stereotactic body radiation therapy |
| Arm 2 Neurovascular sparing stereotactic body radiation therapy | Experimental | Patients undergo MRI or CT-guided SBRT with daily plan adaptation once every other day or on consecutive days if necessary, for a total of 5 treatments over 18 days in the absence of disease progression or unacceptable toxicity. Additionally, patients undergo MRI and CT during screening and blood sample collection throughout the trial. Receives: Radiation: Neurovascular sparing stereotactic body radiation therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Expanded Prostate Cancer Index Composite (EPIC-26) sexual function Questionnaire
The primary endpoint is clinically relevant (≥24 point) decline in EPIC-26 sexual function domain scores at 24 months following treatment in patients randomized to NV-sparing SBRT relative to patients randomized to conventional SBRT without explicit NV-sparing.
Measured: 24 months
Secondary outcomes (7)
Clinically relevant acute change in International Prostate Symptom Score (I-PSS) domain of EPIC-26.
Clinically relevant acute changes (from initiation to within 90 days after completion of SBRT) in IPSS of EPIC-26 patient-reported QOL. The International Prostate Symptom Score (I-PSS) is based on answers to seven questions concerning urinary symptoms and one question concerning quality of life. Answers are assigned points from 0 to 5. The total score range is from 0 -35. 0 indicating no symptoms to 35 indicating extremely symptomatic.
Measured: From initiation to 90 days post treatment
Clinically relevant acute change in Sexual Health Inventory for Men (SHIM) domain of EPIC-26.
Clinically relevant acute changes (from initiation to within 90 days after completion of SBRT) in SHIM domain of EPIC-26 patient-reported QOL. The SHIM score range is from 5 to 25. Higher score indicates better erectile function.
Measured: From initiation to 90 days post treatment
Clinically relevant chronic changes in IPSS, of EPIC-26.
Clinically relevant chronic changes (from initiation to within 90 days after completion of SBRT) in IPSS domain of EPIC-26 patient-reported QOL
Measured: From initiation to 90 days post treatment
Clinically relevant chronic changes in SHIM, of EPIC-26.
Clinically relevant chronic changes (from initiation to within 90 days after completion of SBRT) in SHIM domain of EPIC-26 patient-reported QOL
Measured: From initiation to 90 days post treatment
Gastric ulcer (GU) or Gastriointestinal (GI) toxicity
Incidence of GU or GI toxicity of at least grade 2 by the physician-reported CTCAE criteria.
Measured: From initiation to 90 days post treatment
prostate specific antigen (PSA) completed response at 2 years
PSA completed response at 2 years, defined as proportion of patients with PSA <20% of the pre-SBRT PSA.
Measured: From initiation to 90 days post treatment
Biochemical Recurrence-Free Survival rate
Biochemical Recurrence-Free Survival rates at 5 years, where biochemical recurrence is defined as serum PSA levels 2 ng/mL higher than the post-treatment PSA nadir.
Measured: From initiation to 90 days post treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Dec 2025
- Study start16 Dec 2025
- Primary completion16 Dec 2035 (estimated)
- Study completion16 Dec 2036 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostate CancerStudies of the same condition, open and under way.
- 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Model description
- magnetic resonance angiography (MRA) guided active aid in identifying and avoiding internal pudendal arteries, corpora cavernosa and neurovascular bundles sensitive structures during SBRT.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jonsson Comprehensive Cancer Center
- Sponsor type
- University, hospital or other
- Collaborators
- Viewray Inc.
- Responsible party
- Sponsor
- Investigators
- Amar Kishan, MD, Principal investigator, UCLA / Jonsson Comprehensive Cancer Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07293585
- Sponsor's protocol ID
- 25-2129
- Acronym
- VORTEX
- Status last verified
- Dec 2025
- First submitted
- 16 Dec 2025
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vascular Optimized Radiotherapy Tuned to Critical Structures for Erectile Function Using High-Precision X-Ray Treatment
- ClinicalTrials.gov ID
- NCT07293585
- Acronym / sponsor ID
- VORTEX / 25-2129
- Conditions
- Prostate Cancer
- Keywords
- sexual function
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Jonsson Comprehensive Cancer CenterUniversity, hospital or other
- Collaborators
- Viewray Inc.
- Study start
- 16 Dec 2025 (actual)
- Primary completion
- 16 Dec 2035 (estimated)
- Study completion
- 16 Dec 2036 (estimated)
- First posted
- 19 Dec 2025 (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.
With people living longer after being treated for prostate cancer, quality of life has become a concern when considering the treatment plan. Sometimes after radiation therapy, patients may experience problems that affect the urinary and bowel systems, along with sexual function.
Stereotactic body radiotherapy (SBRT) is a type of radiation technique that delivers five high doses of radiation. At University of California at Los Angeles (UCLA), we have the option to administer SBRT in both our CT-guided and MRI-guided radiation machines.
This trial aims to determine the most effective method for protecting the nerves and blood vessels essential for erectile function, utilizing a technique known as neurovascular sparing.
This technique uses images (i.e., MRI) to map the neurovascular bundles of nerves and blood vessels, which are crucial for erectile function. "Adapting" the radiotherapy treatment for each of these five treatment sessions could enable a more precise delivery of your radiation treatment that is customized based on your internal anatomy immediately before the treatment starts. This is also a standard and low-risk intervention used in many different types of cancer. However, it is a very labor-intensive and time-consuming procedure that requires a team of experts to work together before each of your radiotherapy sessions. We are unsure if the increased complexity associated with this adaptive treatment reduces side effects.
Detailed description
The mechanism implicated in sexual function decline following radiotherapy involves injury to vascular structures surrounding the prostate which are critical for normal erectile function, namely the corpora cavernosa, internal pudendal arteries, and neurovascular bundles. These structures are all in close proximity to the prostate gland and are often included at least partially within the planning target volume margin of treatment plans. As noted above, these planning target volume (PTV) expansions were historically large due to the need to ensure adequate coverage of the target volume to achieve disease control although this likely came at the cost of higher rates of treatment-related toxicity. With enhanced technology for target visualization and intra-fraction motion management, it is technically feasible to reduce margins and spare surrounding normal tissue from receiving the full prescription dose while still treating the target volume with high confidence.
Beyond reducing the isometric PTV expansion due to increased precision in radiation delivery with modern techniques, however, it is now technically feasible to crop out these sensitive Organs-at-risk (OARs) from the final PTV volume in order to further spare them from receiving excess dose. This process, referred to as neurovascular-sparing (NV-sparing), involves the fusion of an MRI and/or MR angiogram to standard radiation planning images to allow accurate contouring of the internal pudendal arteries and neurovascular bundles so that these can be intentionally spared. Daily online adaptive replanning may also play a role in ensuring appropriate coverage of the target volume and sparing of OARs as intended by the treatment plan. To date, no investigations have reported on the clinical or dosimetric outcomes of patients treated with an NV approach in conjunction with these other methods. Furthermore, specific dose constraints for these structures are largely unknown due to the lack of empiric evidence to guide selection.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- magnetic resonance angiography (MRA) guided active aid in identifying and avoiding internal pudendal arteries, corpora cavernosa and neurovascular bundles sensitive structures during SBRT.
| Arm | Type | Receives |
|---|---|---|
| Arm 1 non-adaptive SBRT | Active comparator | Radiation: Neurovascular sparing stereotactic body radiation therapyPatients undergo MRI or CT-guided SBRT without daily plan adaptation once every other day or on consecutive days if necessary, for a total of 5 treatments over 18 days in the absence of disease progression or unacceptable toxicity. Additionally, patients undergo MRI and CT during screening and blood sample collection throughout the trial. |
| Arm 2 Neurovascular sparing stereotactic body radiation therapy | Experimental | Radiation: Neurovascular sparing stereotactic body radiation therapyPatients undergo MRI or CT-guided SBRT with daily plan adaptation once every other day or on consecutive days if necessary, for a total of 5 treatments over 18 days in the absence of disease progression or unacceptable toxicity. Additionally, patients undergo MRI and CT during screening and blood sample collection throughout the trial. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Age ≥ 18.
- Histologically confirmed, clinically localized adenocarcinoma of the prostate.
- Staging workup as recommended by the National Comprehensive Cancer Network (NCCN) on the basis of risk grouping.
- 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 PSMA PET/CT scan below the bifurcation of the renal arteries is allowable).
- Eastern Cooperative Oncology Group (ECOG) performance status ≤2.
Key exclusion criteria (7 listed)
- 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.
- Evidence of intraprostatic lesion by biopsy, MRI, or PSMA PET/CT within the middle third, or both lateral thirds of the prostate gland.
- History of whole-gland cryosurgery, high-intensity focused ultrasound (HIFU), brachytherapy, or other ablative treatments of the whole prostate.
- Prior pelvic radiotherapy.
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 |
|---|---|---|
| Neurovascular sparing stereotactic body radiation therapyUse of adaptive radiotherapy | Radiation | Arm 1 non-adaptive SBRT, Arm 2 Neurovascular sparing stereotactic body radiation therapy |
Primary outcome
Expanded Prostate Cancer Index Composite (EPIC-26) sexual function Questionnaire
Time frame: 24 months
The primary endpoint is clinically relevant (≥24 point) decline in EPIC-26 sexual function domain scores at 24 months following treatment in patients randomized to NV-sparing SBRT relative to patients randomized to conventional SBRT without explicit NV-sparing.
7 secondary outcomes
Clinically relevant acute change in International Prostate Symptom Score (I-PSS) domain of EPIC-26.
Time frame: From initiation to 90 days post treatment
Clinically relevant acute change in Sexual Health Inventory for Men (SHIM) domain of EPIC-26.
Time frame: From initiation to 90 days post treatment
Clinically relevant chronic changes in IPSS, of EPIC-26.
Time frame: From initiation to 90 days post treatment
Clinically relevant chronic changes in SHIM, of EPIC-26.
Time frame: From initiation to 90 days post treatment
Gastric ulcer (GU) or Gastriointestinal (GI) toxicity
Time frame: From initiation to 90 days post treatment
prostate specific antigen (PSA) completed response at 2 years
Time frame: From initiation to 90 days post treatment
Biochemical Recurrence-Free Survival rate
Time frame: From initiation to 90 days post treatment
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 19 Dec 2025.
- Individual participant dataSharing planned: No
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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.
Amar Kishan, MD principal investigator
UCLA / Jonsson Comprehensive Cancer Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Neurovascular sparing stereotactic body radiation therapy in people with Prostate Cancer, run by Jonsson Comprehensive Cancer Center at 1 site in United States.
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 9 inclusion and 7 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 19 Dec 2025. 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 United States. 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.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Christy Palodichuk (310-267-8988, cpalodichuk@mednet.ucla.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Expanded Prostate Cancer Index Composite (EPIC-26) sexual function Questionnaire (time frame: 24 months). 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 19 Dec 2025.