Study of Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy for Abdominopelvic Sarcomas (MARS Trial)

NCT ID: NCT06436612

Last Updated: 2025-06-06

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE2
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-05-30
• Study Completion Date: 2028-05-26

Brief 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.

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.

Conditions

Abdominopelvic Sarcomas

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Arm I

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.

Group Type: EXPERIMENTAL

Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy

Intervention Type: RADIATION

stereotactic body radiation therapy (SBRT) administered over 5 days x 5.0 - 6.0 Gy for patients with abdominopelvic sarcomas.

Interventions

Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy

stereotactic body radiation therapy (SBRT) administered over 5 days x 5.0 - 6.0 Gy for patients with abdominopelvic sarcomas.

Intervention Type: RADIATION

Other Intervention Names

Pre-operative stereotactic body radiation therapy (SBRT)

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

• Active treatment of a separate malignancy
• History of prior irradiation to the area targeted for treatment

• Minimum Eligible Age: 12 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Jonsson Comprehensive Cancer Center

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

UCLA / Jonsson Comprehensive Cancer Center

Los Angeles, California, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Christy Palodichuk

Role: CONTACT

cpalodichuk@mednet.ucla.edu

3107942971

Vincent Basehart

Role: CONTACT

vbasehart@mednet.ucla.edu

3102678954

Facility Contacts

Vincent Basehart

Role: primary

vbasehart@mednet.ucla.edu

3102678954

Christine Palodichuk

Role: backup

cpalodichuk@mednet.ucla.edu

3107942971

Other Identifiers

NCI-2024-04364

Identifier Type: REGISTRY

Identifier Source: secondary_id

23-001583

Identifier Type: -

Identifier Source: org_study_id