The impact of PET/CT and brain MRI for metastasis detection among patients with clinical T1-category lung cancer:...

Area of Science:

• Oncology
• Radiology
• Nuclear Medicine

Background:

• Lung cancer staging relies on detecting metastasis.
• [18F]-FDG PET/CT and brain MRI are standard tools for metastasis detection.
• Current guidelines lack risk stratification for early-stage lung cancer (T1) imaging.

Purpose of the Study:

• To stratify lung cancer patients based on metastatic risk using lesion size and morphology.
• To optimize the use of PET/CT and MRI in clinical T1 lung cancer staging.
• To evaluate the predictive value of PET/CT metabolic parameters for metastasis and overall survival.

Main Methods:

• Retrospective analysis of 2,298 lung cancer patients.
• Detection rates of metastasis were analyzed based on tumor size (solid <8mm, ≥8mm; sub-solid <10mm, ≥10mm) and morphology.
• Receiver operating characteristic (ROC) and Kaplan-Meier analyses were performed using PET/CT metabolic parameters (SUVmax, SUVmean, SULpeak, MTV, TLG).

Main Results:

• No metastasis was found in solid nodules <8mm or sub-solid nodules <10mm.
• Cut-off values for PET/CT metabolic parameters discriminating metastasis were established.
• Patients with larger nodules (solid ≥8mm, sub-solid ≥10mm) who underwent PET/CT plus MRI showed significantly longer overall survival (OS).
• Higher metabolic parameters (SUVmax, SUVmean, SULpeak, MTV, TLG) were associated with shorter OS.

Conclusions:

• PET/CT and MRI necessity should be carefully considered for small nodules (<8mm solid, <10mm sub-solid).
• These imaging modalities are essential for patients with larger nodules (solid ≥8mm, sub-solid ≥10mm).
• Risk stratification based on lesion characteristics improves the judicious use of advanced imaging in lung cancer staging.