Abdominopelvic SarcomasPhase 2NCT06436612
Study of Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy for Abdominopelvic Sarcomas (MARS Trial)
A Phase 2 study testing Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy in people with Abdominopelvic Sarcomas, run by Jonsson Comprehensive Cancer Center at 1 site in United States.
Trial summary
Recent advances in radiation treatment have allowed for higher doses per treatment to be delivered safely. This study plans to use an MRI-guided linear accelerator to deliver the radiation treatment to ensure that the radiation dose is administered to the cancerous tumor, not the vital body organs. Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Abdominopelvic Sarcomas
- What is being tested?
- Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 30 May 2024to 26 May 2028
- Phase
- Phase 2
- 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 12 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Histologically confirmed sarcoma
- Primary or recurrent disease involving the abdomen or pelvis
- Resectable primary lesion
- Age ≥ 12 years old
- Karnofsky performance status (KPS) ≥ 70 or Eastern Cooperative Oncology Group (ECOG) 0-2
- If a woman is of childbearing potential, a negative serum or urine pregnancy test must be documented
Who cannot join
- Active treatment of a separate malignancy
- History of prior irradiation to the area targeted for 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
UCLA / Jonsson Comprehensive Cancer Center
Los Angeles, California, 90095
Vincent Basehart, 3102678954, vbasehart@mednet.ucla.edu
Christine Palodichuk, 3107942971, cpalodichuk@mednet.ucla.edu
About this study
Official title: Phase II Study of Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy for Abdominopelvic Sarcomas (MARS Trial)
Recent advances in radiation treatment have allowed for higher doses per treatment to be delivered safely. This study plans to use an MRI-guided linear accelerator to deliver the radiation treatment to ensure that the radiation dose is administered to the cancerous tumor, not the vital body organs.
Potential participants with a sarcoma diagnosis will be referred to Radiation Oncology during this study. If the participant is interested in participating in this study, s/he receives radiation treatment daily for 5 consecutive days except for weekends and holidays. Within 12 weeks of completing the radiation therapy, the participant will have the primary tumor surgically removed. The radiation oncology team will follow the patients for 5 years after completing radiation therapy.
Read the detailed description
Each patient will undergo radiation simulation and planning. A custom vac-lok bag, alpha cradle, or equivalent immobilization device will be used. Both CT and MRI simulation will be obtained, which is standard of care for any patient undergoing radiation therapy for soft tissue sarcomas.
The study investigator will be responsible for delineating the gross tumor volume (GTV) using the CT as well as MRI performed as part of staging. Guidelines for contouring will be as per the currently open NRG trial for sarcomas. In general, this may entail expansions by 5-15 mm isotropically, should include any suspicious areas be identified on T2 weighted MRI, and should be cropped to natural anatomic borders. This clinical target volume (CTV) will then be expanded to a planning treatment volume (PTV) using a 3-5 mm expansion.
A prescription dose of 5-6 Gy x 5 fractions (25-30 Gy) will be delivered to at least 95% of the PTV. Stereotactic body radiotherapy (SBRT) and/or intensity modulated radiotherapy (IMRT) planning techniques may be used to minimize radiation dose to nearby organs at risk (OAR) but is not required.
Delineation of normal structures will be performed and verified by the responsible study investigator. The radiation physicist or dosimetrist will optimize the treatment plan prior to approval for treatment. Dose volume histograms (DVH) and normal tissue constraint parameters specified below will be used to judge the plan quality and optimize PTV coverage with OAR sparing prior to approval.
Radiation will be delivered daily for 5 consecutive days with the exception of weekends and holidays. In instances where the radiation treatment week contains a holiday or scheduling availability is limited, two fractions of radiation may be given on the same day providing that the fractions are administered ≥ 6 hours apart (this is considered standard of care treatment).
Surgical resection of at least the primary tumor will follow within 12 weeks of completing radiation therapy. Surgical specimens will be sent to pathology for evaluation and for review by a multidisciplinary tumor board.
- Conditions
- Abdominopelvic Sarcomas
- Being tested
- Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation TherapyRadiation
Also called Pre-operative stereotactic body radiation therapy (SBRT)
stereotactic body radiation therapy (SBRT) administered over 5 days x 5.0 - 6.0 Gy for patients with abdominopelvic sarcomas.
| Study group | Role | What they receive |
|---|---|---|
| Arm I | Experimental | MRI or CT-guided SBRT will be delivered in the pre-operative setting. Patients will receive 5.0-6.0 Gy x 5 fractions delivered daily. Receives: Radiation: Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Radiation morbidity at 2 years
Evaluate the 2 year rate of grade ≥2 radiation morbidity, according to Common Terminology Criteria for Adverse Events (CTCAE), Version 5.0.
Measured: At 2 years
Secondary outcomes (5)
Local Control
Defined as freedom from radiographic progression of the treated site. It will be evaluated using CT and/or MRI of the abdomen and pelvis.
Measured: At 2 years
Regional Control
Defined as freedom from radiographic progression in the abdomen or pelvis outside of the treated site. It will be evaluated using CT and/or MRI of the abdomen and pelvis.
Measured: At 2 years
Distant metastasis
Measured: At 2 years
Progression free survival
Measured: At 2 years
Overall survival
Measured: At 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2024
- Study start30 May 2024
- Primary completion30 May 2027 (estimated)
- Study completion26 May 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Abdominopelvic SarcomasStudies of the same condition, open and under way.
- More trials run by Jonsson Comprehensive Cancer CenterThe sponsor's other registered studies.
- 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jonsson Comprehensive Cancer Center
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06436612
- Sponsor's protocol ID
- 23-001583
- Other IDs
- NCI-2024-04364
- Status last verified
- Jun 2026
- First submitted
- 14 May 2024
- Last updated
- 5 Jun 2026
- Results posted
- No
- 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 5 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase II Study of Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy for Abdominopelvic Sarcomas (MARS Trial)
- ClinicalTrials.gov ID
- NCT06436612
- Acronym / sponsor ID
- 23-001583
- Conditions
- Abdominopelvic Sarcomas
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Jonsson Comprehensive Cancer CenterUniversity, hospital or other
- Study start
- 30 May 2024 (actual)
- Primary completion
- 30 May 2027 (estimated)
- Study completion
- 26 May 2028 (estimated)
- First posted
- 31 May 2024 (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.
Recent advances in radiation treatment have allowed for higher doses per treatment to be delivered safely. This study plans to use an MRI-guided linear accelerator to deliver the radiation treatment to ensure that the radiation dose is administered to the cancerous tumor, not the vital body organs.
Potential participants with a sarcoma diagnosis will be referred to Radiation Oncology during this study. If the participant is interested in participating in this study, s/he receives radiation treatment daily for 5 consecutive days except for weekends and holidays. Within 12 weeks of completing the radiation therapy, the participant will have the primary tumor surgically removed. The radiation oncology team will follow the patients for 5 years after completing radiation therapy.
Detailed description
Each patient will undergo radiation simulation and planning. A custom vac-lok bag, alpha cradle, or equivalent immobilization device will be used. Both CT and MRI simulation will be obtained, which is standard of care for any patient undergoing radiation therapy for soft tissue sarcomas.
The study investigator will be responsible for delineating the gross tumor volume (GTV) using the CT as well as MRI performed as part of staging. Guidelines for contouring will be as per the currently open NRG trial for sarcomas. In general, this may entail expansions by 5-15 mm isotropically, should include any suspicious areas be identified on T2 weighted MRI, and should be cropped to natural anatomic borders. This clinical target volume (CTV) will then be expanded to a planning treatment volume (PTV) using a 3-5 mm expansion.
A prescription dose of 5-6 Gy x 5 fractions (25-30 Gy) will be delivered to at least 95% of the PTV. Stereotactic body radiotherapy (SBRT) and/or intensity modulated radiotherapy (IMRT) planning techniques may be used to minimize radiation dose to nearby organs at risk (OAR) but is not required.
Delineation of normal structures will be performed and verified by the responsible study investigator. The radiation physicist or dosimetrist will optimize the treatment plan prior to approval for treatment. Dose volume histograms (DVH) and normal tissue constraint parameters specified below will be used to judge the plan quality and optimize PTV coverage with OAR sparing prior to approval.
Radiation will be delivered daily for 5 consecutive days with the exception of weekends and holidays. In instances where the radiation treatment week contains a holiday or scheduling availability is limited, two fractions of radiation may be given on the same day providing that the fractions are administered ≥ 6 hours apart (this is considered standard of care treatment).
Surgical resection of at least the primary tumor will follow within 12 weeks of completing radiation therapy. Surgical specimens will be sent to pathology for evaluation and for review by a multidisciplinary tumor board.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Arm I | Experimental | Radiation: Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation TherapyMRI or CT-guided SBRT will be delivered in the pre-operative setting. Patients will receive 5.0-6.0 Gy x 5 fractions delivered daily. |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (6 listed)
- Histologically confirmed sarcoma
- Primary or recurrent disease involving the abdomen or pelvis
- Resectable primary lesion
- Age ≥ 12 years old
- Karnofsky performance status (KPS) ≥ 70 or Eastern Cooperative Oncology Group (ECOG) 0-2
Key exclusion criteria (2 listed)
- Active treatment of a separate malignancy
- History of prior irradiation to the area targeted for treatment
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 |
|---|---|---|
| Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation TherapyAlso: Pre-operative stereotactic body radiation therapy (SBRT)stereotactic body radiation therapy (SBRT) administered over 5 days x 5.0 - 6.0 Gy for patients with abdominopelvic sarcomas. | Radiation | Arm I |
Primary outcome
Radiation morbidity at 2 years
Time frame: At 2 years
Evaluate the 2 year rate of grade ≥2 radiation morbidity, according to Common Terminology Criteria for Adverse Events (CTCAE), Version 5.0.
5 secondary outcomes
Local Control
Time frame: At 2 years
Regional Control
Time frame: At 2 years
Distant metastasis
Time frame: At 2 years
Progression free survival
Time frame: At 2 years
Overall survival
Time frame: At 2 years
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 5 Jun 2026.
- Individual participant dataSharing planned: No
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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy in people with Abdominopelvic Sarcomas, 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 6 inclusion and 2 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 5 Jun 2026. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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 (3107942971, cpalodichuk@mednet.ucla.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Radiation morbidity at 2 years (time frame: At 2 years). 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 5 Jun 2026.