Value of 18 F-FDG PET/CT for prognosis evaluation in small cell lung cancer with normal serum lac-tate dehydrogenase / 中华核医学与分子影像杂志

ABSTRACT

Objective To evaluate the value of 18 F-FDG PET/CT imaging in predicting the progno-sis of newly diagnosed SCLC with normal serum LDH ( SCLC-nsLDH) . Methods A total of 68 SCLC pa-tients (59 males, 9 females, median age58.5 years) proved by pathology between June 2005 and Decem-ber 2016 were retrospectively analyzed. All patients underwent 18 F-FDG PET/CT. The general information of patients, including LDH, NSE, OS, PFS and SUVmax , were recorded. SUVmax differences were analyzed with Mann-Whitney u test. Life-table method and Kaplan-Meier analysis were used to estimate the survival rate and median survival time. The survival function curve was drawn. Log-rank test was used to analyze whether there existed statistical differences in survival period among different groups. Cox regression analysis was used for screening the influencing factors of prognosis. Results ( 1) In 68 SCLC patients, there were 38 cases with limited disease ( LD) and 30 cases with extensive disease ( ED) . There were 3 cases in stageⅠ, 7 cases in stage Ⅱ, 29 cases in stage Ⅲ, 29 cases in stage Ⅳ. The median SUVmax of the primary tumor was 11.35 (9.90, 13.90). There was no significant difference between the median SUVmax of LD group and that of ED group11.05(9.72, 13.60) vs 12.25(10. 05, 14.12)months;z=-0.797, P=0.426. The median serum LDH was 195.15(171.00, 220.80) U/L. (2) The median follow-up time was 18(range2-101) months. The disease developed in 46 patients and 35 patients died. The median OS was 23 (95%CI13.3-32.7) months and median PFS was 17 (95% CI 11.4-22.6) months. (3) ROC curve showed the optimal SUVmax cutoff value was 10.85. The OS of patients with SUVmax≤10.85 ( n=25) and with SUVmax>10.85 (n=43) were 40.0(95% CI2.5-77.5) months and 18.0(95% CI13.3-22.7) months(χ2=8.956, P=0.003), respectively. (4)Weight loss, VALG stage and primary tumor SUVmax were independent prog-nostic factors for OS (all P<0.05). Only VALG stage was an independent prognostic factor for PFS (P<0. 001) . Conclusion 18 F-FDG PET/CT can help to differentiate the different prognosis of SCLC-nsLDH patients, and provide more evidence for the choice of individual treatment strategy.