SRT for Residual Oligometastases of NSCLC After 3rd Generation EGFR-TKIs

Recruitment & Eligibility

Inclusion Criteria

The patient has a diagnosis of pathologically confirmed NSCLC by tumor biopsy and/or fine-needle aspiration.
The patient has a diagnosis of American Joint Committee on Cancer (AJCC) 8th Edition stage IV NSCLC.
The patient receives 3rd generation EGFR-TKI in the first line setting.
The patient is ≥18 years of age and ≤75 years of age at the time of screening.
The patient's Karnofsky performance score (KPS) is ≥70 at study entry.
The patient has adequate baseline tumor assessment before initiation of 3rd generation EGFR-TKI.
The patient has at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1.
The patient presents with a residual "oligometastatic" state after 3rd generation EGFR-TKI therapy that would be amenable to consolidative SRT in the opinion of the investigator.
The patient has signed informed consent.
EGFR Exon19 deletion or Exon21 L858R mutation

Exclusion Criteria

History of another malignancy or concurrent malignancy. Patients with cervical carcinoma in situ or adequately treated basal cell carcinoma who have been disease free for > 5 years are eligible.
The patient is pregnant (confirmed by serum b-HCG if applicable) or is breastfeeding.
Patients with uncontrolled epilepsy, mental disorders, drug abuse, or social condition that may affect compliance or ability to sign a written informed consent in the opinion of the investigator.
Patients with residual metastatic disease after 3rd generation EGFR-TKI therapy that is deemed not amenable to consolidative SRT.

Study & Design

Arm && Interventions

Group	Intervention	Description
3rd generation EGFR-TKI+ SRT	Consolidative SRT	Patients were treated with the intent to ablate all residual disease with consolidative SRT. EGFR-TKI treatment was continued during and after consolidative SRT until disease progression or intolerable toxicity.
3rd generation EGFR-TKI+ SRT	3rd generation EGFR-TKI	Patients were treated with the intent to ablate all residual disease with consolidative SRT. EGFR-TKI treatment was continued during and after consolidative SRT until disease progression or intolerable toxicity.

Primary Outcome Measures

Name	Time	Method
Progression Free Survival	Two years	PFS was measured from the date of enrollment to the date of disease progression as defined by Response Evaluation Criteria in Solid Tumor (RECIST) Version 1.1 or death due to any cause, whichever occurred first. For patients whose disease did not progress, PFS was evaluated by censoring patients at their most recent imaging.

Secondary Outcome Measures

Name	Time	Method
Percentage of Participants With Adverse Events	Two years	Treatment-related adverse events were assessed and graded according to CTCAE v. 5.0.
Overall Survival	Two years	OS was defined as the time from the date of enrollment until death by any cause. Participants still alive at the time of data analysis were censored at the date of last follow-up.

Recruitment & Eligibility