Purpose: In NSCLC p?tients with multiple lesions, the differenti?tion between met?st?ses ?nd second primary tumours h?s significant therapeutic ?nd prognostic implications. The aim of this retrospective study was to compare the SUVm?x of 18F-FDG PET between metastatic disease ?nd second primary lung tumours.
Methods: Of 318 NSCLC p?tients between November 2015 ?nd October 2018 ?t B?ch M?i hospit?l, Vietn?m, p?tients with ? synchronous second prim?ry lung c?ncer were selected. P?tients with met?st?tic dise?se involving the lungs served ?s the control group. M?ximum st?nd?rdized upt?ke v?lues (SUVs) me?sured with 18F-FDG PET were determined for two tumours in e?ch p?tient. The SUVm?x was determined ?nd comp?red between the second prim?ry group ?nd met?st?tic dise?se group. Receiver-oper?ting ch?r?cteristic (ROC) curve ?n?lysis w?s performed to determine the sensitivity ?nd specificity of the SUVm?x for ?n optim?l cut-off v?lue.
Results: ? tot?l of 81 NSCLC p?tients (44 met?st?tic dise?se, 37 second prim?ry c?ncer) were included for ?n?lysis. The SUVm?x w?s signific?ntly higher in p?tients with second prim?ry c?ncer th?n in those with met?st?tic dise?se (7.53 ± 4.33 vs. 4.35 ± 2.58, respectively, p<0.001). The ?re? under the ROC curve w?s 0.727 ?nd for the optim?l cut-off w?s 7.52 ?ssoci?ted with ? sensitivity, specificity 70.3% (95% CI: 53.0-84.1); 93.2% (95% CI: 81.3-98.6), respectively.
Conclusion: SUVm?x from 18F-FDG PET im?ges c?n be helpful in differenti?ting met?st?tic dise?se from second prim?ry tumours in p?tients with synchronous pulmon?ry lesions. Further studies ?re w?rr?nted to confirm the consistency of these results.Author(s): Huynh Quang Huy