Total RadIoTherapy of Oligometastatic caNcerS (TRITONS)

October 9, 2025 updated by: Tyler Seibert, University of California, San Diego

Total RadIoTherapy of Oligometastatic caNcerS (TRITONS)

This is a Phase III non-blinded randomized study evaluating patients with oligometastatic cancers (up to 10 metastases). Subjects are randomized 1:1 to stereotactic ablative radiotherapy (SABR) plus standard of care therapies versus standard of care therapies alone. The investigators will measure progression-free survival at 2 years based on the hypothesis that subjects treated with SABR plus standard of care will not experience disease progression for a longer period of time than subjects treated with standard of care alone. The investigators will also measure overall survival and safety of SABR, as well as biomarkers that may help predict, in the future, who will benefit from the SABR treatment.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Patients with metastatic solid malignancies are generally deemed incurable. Systemic therapies (cytotoxic chemotherapy, immunotherapy, hormonal therapy, etc.) can be effective for prolonging life, but cancers will eventually become resistant, prompting transition to second-line therapies that are often more toxic and/or more expensive with diminishing oncologic benefit. In patients with relatively few detectable metastases, SABR to visible tumors may substantially delay progression and thus improve quality of life. Unfortunately, most patients with metastatic disease will eventually die from their cancer. Stereotactic ablative radiotherapy (SABR) is highly effective, often achieving long-term local control. Previous studies demonstrated that SABR improves survival and quality of life in patients with oligometastatic cancer. However, these studies were small and not randomized. Thus, this randomized study will better evaluate the efficacy and safety of SABR in oligometastatic cancer.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • La Jolla, California, United States, 92093
        • Recruiting
        • University of California, San Diego

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Provision of signed and dated informed consent form.
  2. Stated willingness to comply with all study procedures and availability for the duration of the study.
  3. Age at least 18 years.
  4. Deemed eligible to undergo standard systemic therapy and SABR to metastatic sites (i.e., patient has adequate health and life expectancy, and treatment is not contraindicated).
  5. Histopathologic confirmation of a solid malignancy.
  6. Newly diagnosed or progressive metastasis (at least 1 and no more than 10 discrete distant metastases visible on staging imaging. At least one metastatic lesion must be outside the brain parenchyma) for which a new line of systemic therapy is started or resumed.
  7. New systemic therapy for metastatic disease initiated no more than 6 months prior to randomization.
  8. For participants able to become pregnant: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during active SABR treatment.
  9. For participants able to cause a pregnancy: use of condoms or other methods to ensure effective contraception with partner during active SABR treatment.

Exclusion Criteria:

  1. Pregnancy.
  2. Contraindications to radiotherapy, including interstitial lung disease if thoracic radiation is planned; Crohn's disease if the gastrointestinal tract will receive radiotherapy; active connective tissue disorders such as scleroderma or uncontrolled lupus; moderate or severe liver dysfunction (Child Pugh B or C) if the patient has liver metastases.
  3. Prior radiation therapy to an area requiring treatment in the present study, if the composite dose would exceed normal tissue constraints specified by UC San Diego Radiotherapy Standards and Guidelines (published by the Department of Radiation Medicine and Applied Sciences), or by local institutional radiotherapy dose constraints for safety and efficacy.
  4. Malignant pleural effusion or malignant ascites.
  5. Leptomeningeal disease in the central nervous system.
  6. Metastatic disease in a site where it is not possible to safely treat with SABR to the doses specified in the trial.
  7. Any unresected metastasis >5 cm in largest diameter or >3 cm in the brain.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: SABR+SOC
stereotactic ablative radiotherapy (SABR) plus standard of care (SOC) cancer therapy
Radiation: stereotactic ablative radiotherapy
Stereotactic ablative radiotherapy is a highly focused radiation treatment that gives an intense dose of radiation concentrated on a tumor, while limiting the dose to the surrounding organs.
Other Names:
  • SABR
No Intervention: SOC
standard of care (SOC) cancer therapy

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Progression-Free Survival (PFS)
Time Frame: 2 years
Rate of Progression Free Survival in the two study arms
2 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
All-grade and grade ≥3 toxicity
Time Frame: 2 years
All-grade and grade ≥3 toxicity per CTCAE
2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, San Diego

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tyler Seibert, University of California, San Diego

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 12, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2033

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 1, 2034

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 4, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 4, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 19, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 14, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 9, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2025

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 810616

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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