NCT05578274

Brief Summary

Stereotactic body radiotherapy (SBRT) has been known to enhance the abscopal effect by up to 40% when delivered with immune checkpoint inhibitors (ICIs). Recently, preclinical and clinical studies demonstrate that metastatic lesions treated with non-cytotoxic low-dose radiotherapy (LDRT) significantly were reduced in the condition where SBRT and ICIs were administered together. Given that ICIs are highly expensive and some tumors are beyond the indications of ICIs, novel approaches are required to boost the abscopal effect in the absence of ICIs. Therefore, the investigators design a multicenter, randomized clinical trial that investigates the efficacy and safety of LDRT combined with SBRT in metastatic cancer patients. The primary endpoint is a lesion-specific response of LDRT lesions (i.e., abscopal effect) evaluated three months after radiotherapy. Subjects will be randomly allocated into two groups (1:1) with the stratification by planning target volume and previous use of ICIs: control group (SBRT in three fractions) or experimental group (SBRT + LDRT in three factions). Unless patients agree with randomization, subjects will participate in a prospective cohort study.

Trial Health

65
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
186

participants targeted

Target at P75+ for not_applicable

Timeline
7mo left

Started Jun 2025

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress62%
Jun 2025Dec 2026

First Submitted

Initial submission to the registry

September 27, 2022

Completed
16 days until next milestone

First Posted

Study publicly available on registry

October 13, 2022

Completed
2.6 years until next milestone

Study Start

First participant enrolled

June 1, 2025

Completed
7 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2026

Completed
11 months until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2026

Expected
Last Updated

December 10, 2024

Status Verified

December 1, 2024

Enrollment Period

7 months

First QC Date

September 27, 2022

Last Update Submit

December 5, 2024

Conditions

Keywords

Neoplasm Metastasis

Outcome Measures

Primary Outcomes (1)

  • Abscopal effect rate of low-dose radiotherapy lesions

    3 months after completion of radiotherapy

Secondary Outcomes (2)

  • Abscopal effect rate of low-dose radiotherapy lesions

    1, 6, and 12 months after completion of radiotherapy

  • Overall response rate

    1, 3, 6, and 12 months after completion of radiotherapy

Other Outcomes (3)

  • Progression-free survival rate

    12 months after completion of radiotherapy

  • Overall survival rate

    12 months after completion of radiotherapy

  • Adverse event

    up to 12 months after completion of radiotherapy

Study Arms (2)

SBRT+LDRT

EXPERIMENTAL

In the experimental group, stereotactic body radiotherapy (SBRT) and low-dose radiotherapy (LDRT) are administered concurrently. SBRT is administered three times, at intervals of 1-2 days, with LDRT. LDRT is planned to irradiate EQD2 6 Gy considering the scattered dose caused by SBRT.

Radiation: SBRT + LDRT

SBRT alone

ACTIVE COMPARATOR

In the control group, stereotactic body radiotherapy (SBRT) alone is performed. SBRT is administered three times, at intervals of 1-2 days. The scattered dose should not exceed EQD2 2Gy to the non-irradiated lesion.

Radiation: SBRT alone

Interventions

SBRT + LDRTRADIATION

SBRT is performed according to the protocol of each institution. However, the total fraction of SBRT is fixed to 3, and the treatment interval is maintained for 1-2 days. The scattered dose should not exceed EQD2 (α/β=10) 2 Gy for non-irradiated lesions. LDRT is planned to irradiate EQD2 (α/β=10) 6 Gy to lesions, considering the scattered dose caused by SBRT. If there are non-irradiated lesions, they are defined as internal control, and the total dose is limited to 0.5 Gy or less. CTV allows up to 5 mm margin for GTV, and 3-10mm for PTV margin from CTV. It is planned that the iso-dose line corresponding to the prescribed dose contains at least 90% of PTV and 95% of GTV.

SBRT+LDRT
SBRT aloneRADIATION

SBRT is performed according to the protocol of each institution. However, the total fraction of SBRT is fixed to 3, and the treatment interval is maintained for 1-2 days. The scattered dose should not exceed EQD2 (α/β=10) 2 Gy for non-irradiated lesions.

SBRT alone

Eligibility Criteria

Age19 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Randomization study: Patients who can provide their written informed consent
  • Cohort study: Patients who do not consent to randomization and who are able to consent to a prospective cohort study and provide written informed consent
  • Age ≥19 years
  • Patients with histologically confirmed primary solid (irrespective of the status of the primary tumor)
  • Patients with ECOG performance status 0-2
  • Patients planning stereotactic body radiotherapy for extracranial metastases
  • Based on RECIST v1.1, patients with at least one extracranial measurable lesion other than SBRT lesions
  • Patients with one or more measurable lesions, which are not suitable for SBRT or palliative radiotherapy and can be considered for LDRT (bone metastasis is not indicated for LDRT)
  • Patients with hematologic function suitable for radiotherapy (absolute neutrophil count ≥1,500/mm\^3, hemoglobin ≥9 g/dL, platelet count ≥100,000/mm\^3)
  • Patients with a life expectancy of 6 months or more according to the researcher's judgment

You may not qualify if:

  • Patients participating in other clinical studies that may affect the efficacy/safety of this clinical study
  • Patients with brain metastasis
  • Patients planning SBRT for all measurable lesions due to oligometastasis
  • Patients with a history of radiotherapy for extracranial metastases within 3 months of the enrollment
  • Patients unable to cooperate with stereotactic body radiotherapy
  • Patients who are pregnant or planning to
  • Patients with advanced or multiple malignancies requiring aggressive treatment (excluding skin cancers other than melanoma or intraepithelial cancer)
  • Patients who have received systemic steroid therapy or immunosuppressive therapy within 2 weeks of enrollment - Patients with an (e.g. allergic disease, radiation pneumonitis, etc.) active autoimmune disease requiring systemic treatment within the past 2 years, evidence of clinically severe autoimmune disease, or syndrome requiring systemic steroid or immunosuppressive therapy (Patients who need intermittent use of bronchodilators, inhaled steroids, or topical steroid injections, hypothyroid patients on stable hormone replacement therapy, type 1 diabetes patients, or patients recovering from childhood asthma/atopic dermatitis are permitted)
  • Patients with active infection requiring systemic treatment

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

NeoplasmsNeoplasms, Second PrimaryNeoplasm Metastasis

Interventions

Radiosurgery

Condition Hierarchy (Ancestors)

Neoplastic ProcessesPathologic ProcessesPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

RadiotherapyTherapeuticsStereotaxic TechniquesNeurosurgical ProceduresSurgical Procedures, OperativeInvestigative Techniques

Study Officials

  • Ah Ram Chang, MD, PhD

    Soonchunhayng Universtiy Seoul Hospital

    STUDY CHAIR

Central Study Contacts

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Director of Radiation Oncology

Study Record Dates

First Submitted

September 27, 2022

First Posted

October 13, 2022

Study Start

June 1, 2025

Primary Completion

January 1, 2026

Study Completion (Estimated)

December 1, 2026

Last Updated

December 10, 2024

Record last verified: 2024-12