Abstract
Background This study was aimed to examine the significance of fluorodeoxyglucose positron emission tomography in predicting prognosis after segmentectomy in lung cancer.
Methods This was a retrospective cohort study, including 227 patients with cT1N0M0 nonsmall cell lung cancer who underwent positron emission tomography followed by segmentectomy between 2012 and 2019. Significance of tumor histology, T-stage, tumor size, and standardized uptake value on positron emission tomography in relation to recurrence-free survival were examined using Cox's proportional hazard analysis. Median follow-up period was 56 months (range: 1–95 months).
Results Tumor stages were Tis in 25 patients, T1mi/T1a in 51, T1b in 98, and T1c in 53. Twenty-six patients (11%) experienced recurrences, including local (n = 8) and distant (n = 18). Multivariate analysis showed that the significant variables for recurrence-free survival were T-stage and standardized uptake value (p = 0.002 and 0.015, respectively), whereas tumor histology and tumor size were not significant (p = 0.28 and 0.44, respectively). When tumor size was divided into ≤2 cm and >2 cm for analysis, it was not significant again (p = 0.49), whereas standardized uptake value remained significant (p = 0.008). While standardized uptake value of tumors with recurrences was significantly higher than those without (4.9–2.8 and 2.6–2.5, respectively, p < 0.001), there was no significant difference between local and distant recurrences (p = 0.32). Cut-off value of standardized uptake value for recurrences was 3.2. Five-year recurrence-free survival rates in tumors with standardized uptake value <3.2 and ≥3.2 were 86 and 65%, respectively (p < 0.001).
Conclusion Positron emission tomography could predict the prognosis after segmentectomy better than tumor size.
Optimal standardized uptake value threshold for auto contouring of gross tumor volume using positron emission tomography/computed tomography in patients with operable nonsmall-cell lung cancer: Comparison with pathological tumor size
