A Randomized Phase III Trial of Stereotactic Ablative Radiotherapy for Patients With Up to 10 Oligometastases and a Synchronous Primary Tumor. (SABR-SYNC)

December 24, 2025 updated by: David Palma

This study is a phase III multi-institutional randomized trial. Patients will be randomized in a 1:2 ratio between current standard of care treatment (Arm 1) vs. standard of care treatment + SABR (Arm 2) to sites of known disease.

Patients will be stratified by two of the strongest prognostic factors, based on a large multi-institutional analysis3: histology (Group 1: hormone-sensitive prostate cancer, breast, or renal; Group 2: all others), and number of metastases (Group 1: 1-3; Group 2: 4-10).

Study Overview

Status

Recruiting

Conditions

Metastatic Tumor

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

180

Phase

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

Name: David Palma, MD, PhD
Phone Number: 519-685-8650
Email: David.Palma@lhsc.on.ca

Study Locations

Canada
- British Columbia
  - Prince George, British Columbia, Canada, V2M 7E9
    - Not yet recruiting
    - BC Cancer - Centre for the North
    - Principal Investigator:
      
      Robert Olson, MD, MSc
  - Vancouver, British Columbia, Canada, V5Z 4C2
    - Recruiting
    - BC Cancer - Vancouver
    - Principal Investigator:
      
      Srinivas Raman, MD
    - Contact:
      
      Tina Zhang, MD
      
      Phone Number: 604-877-6000
      
      Email: srinivas.raman@bccancer.bc.ca
- Ontario
  - London, Ontario, Canada, N6A 5W9
    - Recruiting
    - London Regional Cancer Program of the Lawson Health Research Institute
    - Contact:
      
      David Palma, MD, PhD
      
      Phone Number: 519-685-8650
      
      Email: David.Palma@lhsc.on.ca
    - Principal Investigator:
      
      David Palma, MD, PhD
- Quebec
  - Montreal, Quebec, Canada, H2X 0C1
    - Recruiting
    - Centre Hospitalier de l'Université de Montréal-CHUM
    - Contact:
      
      Toni Vu
      
      Phone Number: 514-575-7690
      
      Email: thi_trinh_thuc.vu.med@ssss.gouv.qc.ca
    - Principal Investigator:
      
      Toni Vu, MD, FRCP (C)
Switzerland
- - Zurich, Switzerland
    - Recruiting
    - UniversitätsSpital Zürich
    - Contact:
      
      Matthias Guckenberger, MD
      
      Phone Number: +41 44 255 35 66
      
      Email: Matthias.Guckenberger@usz.ch

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

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Description

Inclusion Criteria:

Age 18 years or older
Willing to provide informed consent
Karnofsky performance status > 60
Life expectancy > 6 months
Histologically confirmed malignancy with metastatic disease detected on imaging. Biopsy of metastasis is preferred, but not required.
Total number of metastases 1-10 at the time of enrollment, with a primary tumor also present
Restaging completed within 12 weeks prior to randomization (see section 5.1)
For patients receiving thoracic radiotherapy, the enrolling physician must confirm there are no computed tomography (CT) changes suggestive of fibrotic interstitial lung disease (ILD) (i.e. reticular changes, traction bronchiectasis, or honeycombing) reported on any prior CT scans. If any are present, the patient must be assessed by a respirologist to rule out ILD prior to enrollment.
10 or fewer lifetime metastases from the cancer for which participants are being enrolled

Exclusion Criteria:

Serious medical comorbidities precluding radiotherapy. These include ILD in patients requiring thoracic radiation, Crohn's disease in patients where the gastrointestinal (GI) tract will receive radiotherapy, or ulcerative colitis where the bowel will receive radiotherapy and connective tissue disorders such as lupus or scleroderma.
For patients with liver metastases, moderate/severe liver dysfunction (Child Pugh B or C); please see the Child-Pugh score calculator.
Substantial overlap with a previously treated radiation volume. Prior radiotherapy in general is allowed, as long as the composite plan meets dose constraints herein. For patients treated with radiation previously, biological effective dose calculations should be used to equate previous doses to the tolerance doses listed in Appendix 1. All such cases must be discussed with a member of the study steering committee.
Malignant pleural effusion
Inability to treat all sites of disease
Brain metastasis > 3 cm in size or a total volume of brain metastases greater than 30 cc.
Metastasis in the brainstem
Clinical or radiologic evidence of spinal cord compression
Metastatic disease that invades any of the following: GI tract (including esophagus, stomach, small or large bowel), or skin
Pregnant or lactating women

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)

Number of Arms

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Standard Arm (Arm 1) Radiotherapy for patients in the standard arm should follow the principles of palliative radiotherapy as per the individual institution, with the goal of alleviating symptoms or preventing imminent complications.	Radiation: Palliative Radiotherapy Radiotherapy for patients in the standard arm should follow the principles of palliative radiotherapy as per the individual institution, with the goal of alleviating symptoms or preventing imminent complications. Recommended dose fractionations in this arm will include 8 Gy in 1 fraction, 20 Gy in 5 fractions, and 30 Gy in 10 fractions. Drug: Chemotherapy Pre-specified based on the standard of care approach for that patient. Other Names: Cytotoxic Systemic Therapy Drug: Hormone therapy Pre-specified based on the standard of care approach for that patient. Other Names: Hormonal Systemic Therapy Drug: Immunotherapy Pre-specified based on the standard of care approach for that patient. Drug: Targeted Systemic Therapy Pre-specified based on the standard of care approach for that patient. Other: Observation Pre-specified based on the standard of care approach for that patient.
Experimental: Experimental Arm (Arm 2) Consists of treatment to the primary tumor and metastases, with SABR preferred, but other options all allowable (e.g. surgery, RFA, fractionated radiation, chemoradiation) if those are deemed to be preferable by the treating oncologists.	Radiation: Palliative Radiotherapy Radiotherapy for patients in the standard arm should follow the principles of palliative radiotherapy as per the individual institution, with the goal of alleviating symptoms or preventing imminent complications. Recommended dose fractionations in this arm will include 8 Gy in 1 fraction, 20 Gy in 5 fractions, and 30 Gy in 10 fractions. Drug: Chemotherapy Pre-specified based on the standard of care approach for that patient. Other Names: Cytotoxic Systemic Therapy Drug: Hormone therapy Pre-specified based on the standard of care approach for that patient. Other Names: Hormonal Systemic Therapy Drug: Immunotherapy Pre-specified based on the standard of care approach for that patient. Drug: Targeted Systemic Therapy Pre-specified based on the standard of care approach for that patient. Other: Observation Pre-specified based on the standard of care approach for that patient. Radiation: Stereotactic Ablative Radiotherapy The primary tumor may be treated with SABR or with other local modalities at the discretion of the treating team and/or the local multidisciplinary tumor board. Preferred doses are 20 Gy in 1 fraction, 30 Gy in 3 fractions (every second day), and 35 Gy in 5 fractions (daily). Procedure: Surgery Treatment to the primary tumor and metastases, with SABR preferred, but other options all allowable if those are deemed to be preferable by the treating oncologists. The primary tumor may be treated with SABR or with other local modalities at the discretion of the treating team and/or the local multidisciplinary tumor board. Because of the convenience in using SABR for all lesions, non-SABR modalities should only be used if they are likely to provide a benefit over SABR. Other: Radiofrequency Therapy (RFA) Treatment to the primary tumor and metastases, with SABR preferred, but other options all allowable if those are deemed to be preferable by the treating oncologists. Radiation: Fractionated Radiation Treatment to the primary tumor and metastases, with SABR preferred, but other options all allowable if those are deemed to be preferable by the treating oncologists. Tumors in the esophagus, stomach, small intestine or colon should be treated with either fractionated radiation or a lower SABR dose (e.g. 25 Gy in 5 fractions) to minimize the risk of perforation.

Participant Group / Arm

Intervention / Treatment

Active Comparator: Standard Arm (Arm 1)

Radiation: Palliative Radiotherapy

Radiotherapy for patients in the standard arm should follow the principles of palliative radiotherapy as per the individual institution, with the goal of alleviating symptoms or preventing imminent complications. Recommended dose fractionations in this arm will include 8 Gy in 1 fraction, 20 Gy in 5 fractions, and 30 Gy in 10 fractions.

Drug: Chemotherapy