[Correlation analysis between 18F-FDG uptake features and the prognosis in patients with pathologic stage Ⅰ lung adenocarcinoma]

OBJECTIVE

To analyze the (18)F-FDG uptake features and the correlation between (18)F-FDG uptake and the prognosis in patients with pathologic stageⅠlung adenocarcinoma.

METHODS

One hundred and seventeen patients with stageⅠlung adenocarcinoma proved by surgery, who underwent a preoperative (18)F-FDG PET-CT, were studied retrospectively. The tumors' SUVmax in different groups of clinicopathologic factors were compared. The correlations between the SUVmax and clinicopathologic factors were analyzed using Spearman rank correlation. The ROC was plotted to estimate the most discriminative cut-off point for SUVmax in predicting the recurrence or progression of tumor. The progression-free survival (PFS) in different clinicopathologic groups were estimated using the Kaplan-Meier method and Log-rank test.

RESULTS

The SUVmax of pathologic stageⅠlung adenocarcinomas were significantly different in different groups of gender, tumor size, density, tumor differentiation grade and T staging, respectively (P<0.05 for all). Patients with a larger tumor size, a higher proportion of solid component, poorer grade of tumor differentiation had a higher SUVmax. The T1b group had a higher SUVmax than T1a and T2a groups. The male group had a higher SUVmax than the female group. The SUVmax was positively correlated with the size of the adenocarcinomas (P<0.01), and was negatively correlated with both the density and tumor differentiation grade (P<0.01). But there was no correlation between SUVmax and the T stage (P>0.05). The patients with an SUVmax of <3.0 had a much better PFS (75.1±3.0 month)than those with an SUVmax of ≥3.0 (52.7±5.9 month)(P<0.01). The tumor with a poorer differentiation grade was associated with reduced PFS (45.7±5.4 months) compared with those with well differentiated tumor (76.7±4.2 month)(P<0.05). The PFS showed no statistically significant differences in different gender, age, smoking history, tumor size, density and T staging groups (P>0.05).

CONCLUSIONS

(18)F-FDG uptake is correlated with the tumor size, density, and differentiation grade, and has a prognostic value for predicting the PFS in the patients with pathologic stageⅠ lung-adenocarcinoma. Patients with an SUVmax of <3.0 have a much better PFS than those with an SUVmax of ≥3.0.