Detecting cancer DNA in blood after radiation therapy for lung tumors

Detection of Circulating Tumor DNA After Stereotactic Ablative Radiotherapy in Patients With Unbiopsied Lung Tumors

Observational London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's · NCT05921474

This study is testing if a blood test can find cancer DNA in patients with early lung cancer after they receive radiation therapy, to see if it works better than regular tests at spotting a return of the cancer.

Quick facts

Study typeObservational
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorLondon Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's Academic / other
Drugs / interventionsradiation
Locations1 site (London, Ontario)
Trial IDNCT05921474 on ClinicalTrials.gov

What this trial studies

This observational study aims to evaluate the effectiveness of liquid biopsies in detecting circulating tumor DNA (ctDNA) in patients with stage I non-small cell lung cancer (NSCLC) who are undergoing stereotactic ablative radiotherapy (SABR). It will compare the ability of liquid biopsies to predict cancer recurrence against standard diagnostic methods. The study will include two cohorts: one with patients who have suspected lung cancer without a biopsy and another with those who have biopsy-proven NSCLC. The researchers will also assess the detection rates of targetable mutations and correlate ctDNA findings with pre-treatment malignancy probabilities.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with suspected or confirmed stage I/IIA NSCLC planning to undergo SABR.

Not a fit: Patients with contraindications to radiotherapy or a history of invasive malignancy within the past five years may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a safer and faster method for diagnosing and monitoring lung cancer recurrence in patients who cannot undergo traditional biopsies.

How similar studies have performed: Other studies have shown promise in using liquid biopsies for cancer detection, suggesting this approach may be effective.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 18 years or older
* Willing to provide informed consent
* Undergoing SABR for a solitary pulmonary nodule (SPN) with tissue confirmation or those without tissue confirmation of malignancy, must have a pretreatment likelihood of malignancy of ≥ 60% using either the Herder or Brock models (60% probability was chosen to have a reasonable chance that there will indeed be cancer in the nodule; however, most patients are expected to have a pretreatment probability of \> 85%).
* Tumor stage T1-T2b (≤ 5 cm)
* No evidence of nodal or distant metastases
* Eastern Cooperative Oncology Group (ECOG) performance status 0-3

Exclusion Criteria:

* Contraindications to radiotherapy
* Prior history of any invasive malignancy within 5 years, which might interfere with the interpretation of the ctDNA results. Non-melanoma skin cancer is allowed if under appropriate control.

Where this trial is running

London, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Non Small Cell Lung CancerEarly Stage Lung CancerStage I/IIATumor stage T1-T2b
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.