EP430\u2005Combination of FDG-PET metabolic parameters of cervical tumor and pelvic lymph nodes predict paraaortic lymph node involvement in locally advanced cervix cancer

Abstract

Introduction/Background Fluorine18 fluorodeoxy glucose positron emission tomography/computed tomography (FDG-PET/CT) is recommended for paraaortic lymph node (PALN) assessment in locally advanced cancer (LACC). Role of surgical staging remains unclear. Aim of our study was to evaluate whether FDG-PET/CT cervical tumor metabolic parameters can predict PALN metastasis. Methodology Patients diagnosed with LACC with available pretherapeutic FDG-PET/CT treated between 2006 and 2015 were included. Two senior nuclear physicians experts in gynaecologic oncology reviewed all PET/CT exams, and extracted SUVmax, MTV, TLG (Standardized Uptake Value, Metabolic Tumor Volume, Total Lesion Glycolysis, respectively) for cervical tumor, and for pelvic lymph nodes (PLN) when positive. Patients were divided in three groups following PALN status: PET positive (PET +), PET negative and surgicopathologic positive (PET-/path+), PET and surgicopathologic negative (PET-/path-). Results 160 patients were included. FDG-PET/CT PALN uptake was found in 34 patients (21,3%). 126 (78,8%) patients had laparoscopic paraaortic lymph node retroperitoneal staging: 17 patients (13,5%) and 109 patients (86,5%) had negative and positive PALN on surgicopathologic analysis respectively (figure 1). PLN were positive on FDG-PET/CT in 28 patients (90,3%). Cervical tumor MTV and TLG were significantly different increased in patients with false negative aortic FDG-PET/CT results (table 1). PLN metabolic parameters were also significantly different in the 3 PALN groups (table 2). Conclusion Cervical tumor and pelvic lymph nodes FDG-PET/CT metabolic parameters are predictive biomarkers of paraaortic lymph node involvement in LACC patients. Disclosure Nothing to disclose. Abstract EP430 Figure 1 Flow chart Abstract EP430 Table 1 Cervical tumor parameters (n=160)] PET+ (n=34) PET-/path+ (n=17) PET-/path- (n=109) p-value SUVmax: median (range) 14,7 (6,0–23,9) 15,3 (7,4–31,8) 14,5 (2,1–34,4) 0,3866 MTV: median (range) 54 (10,5–299) 73,1 (8,8–120) 34,0 (0,8–162) 0,0004 TLG: median (range) 360,6 (42,2–3181,0) 496,8 (43,4–1455,7) 234,0 (1,2–2495,0) 0,0174 Abstract EP430 Table 2 Pelvic lymph node parameters (n=68). *PLN parameters were studied for the most avid PLN] PET + (n=28) PET -/path + (n=10) PET - /path - (n=30) p-value Number of positive PLN : median (range) 4 (1–10) 3 (2–11) 2 (1–5) 0,0008 SUVmax* : median (range) 6,6 (1,8–16,1) 12,6 (4,7–17,1) 4,7 (1,7–16,4) 0,0046 MTV*: median (range) 2,4 (0,2–8,8) 5,1 (1,3–14,3) 1,7 (0,3–22,8) 0,0549 TLG*: median (range) 10,4 (0,4–76,8) 36,2 (3,1–68,4) 5,8 (0,6–152,2) 0,0139