Diagnostic Accuracy of [F]FDG PET/CT versus CT for NSCLC Surveillance: Secondary Analysis of a Randomized Clinical Trial.

[BACKGROUND] Following curative treatment for non-small cell lung cancer (NSCLC), surveillance to detect recurrence is recommended. While computed tomography (CT) is the current standard for follow-up imaging, the optimal surveillance strategy remains debated. This study compares the diagnostic accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT; hereafter referred to as PET/CT) and CT for NSCLC surveillance.

[MATERIALS AND METHODS] This study represents a secondary analysis of data from a randomized controlled trial (SUPE_R, ClinicalTrials.gov NCT03740126) of patients with stage IA-IIIC NSCLC who completed curative-intent treatment between February 2019 and February 2022. CT and PET/CT scans were compared for recurrence detection using biopsy, multidisciplinary team assessment, or follow-up imaging as reference standards.

[RESULTS] The analysis included 899 PET/CT scans and 852 CT scans from 692 patients (mean age 69 years ± 8 [SD]; 412 female). For detecting recurrence, PET/CT demonstrated a higher sensitivity (88% [95% CI, 80%-93%] vs. 62% [95% CI, 50%-73%]; P < .001) but lower specificity (89% [95% CI, 86%-91%] vs. 96% [95% CI, 94%-97%]; P < .001) compared to CT. PET/CT demonstrated a higher sensitivity compared to CT after treatment with chemoradiotherapy (100% [95% CI, 72%-100%] vs. 46% [95% CI, 19%-75%]; P = .006) and at 0 to 6 month after treatment (83% [95% CI, 63%-94%] vs. 41% [95% CI, 21%-65%]; P = .008).

[CONCLUSION] The higher sensitivity of PET/CT, particularly after chemoradiotherapy and early post-treatment, suggests it may be particularly valuable in these high-risk scenarios. However, CT remains preferred for routine surveillance of low-risk patients given its superior specificity.