False negative rate at 18F-FDG PET/CT in para-aortic lymphnode involvement in patients with locally advanced cervical cancer: impact of PET technology

Abstract

Background The identification of factors responsible for false negative (FN) rate at 18F- Fluorodeoxyglucose (FDG) Positron Emission Tomography /Computed Tomography (PET/CT) in para-aortic (PA) lymph nodes in the presurgical staging of patients with locally advanced cervical cancer (LACC) is challenging. The aim of this study was to evaluate the impact of PET/CT technology. Methods A total of 240 consecutive patients with LACC (International Federation of Gynecology and Obstetrics, FIGO, stage IB2-IVA) and negative Magnetic Resonance Imaging (MRI) and/or Computed Tomography (CT) and negative 18F-FDG PET/CT in the PA region, undergoing laparoscopic PA lymphadenectomy before chemoradiotherapy were included. The FN rate in patients studied with Time of flight (TOF) PET/CT (TOF PET) or non-Time of flight PET/CT (no-TOF PET) technology was retrospectively compared. Results Patients presented with FIGO stage IB (n = 78), stage IIA-B (n = 134), stage III (n = 18) and stage IVa (n = 10), squamous cell carcinoma (n = 191) and adenocarcinoma (n = 49). 141/240 patients were evaluated with no-TOF PET/CT and 99/240 with TOF PET/CT. Twenty-two patients (9%) had PA nodal involvement at histological analysis and considered PET/CT FN findings. The FN rate was 8.5% for no-TOF PET and 10% for TOF PET subgroup respectively (p = 0.98). Ninety patients (38%) presented with pelvic node uptakes at PET/CT. The FN rate in the PA region was 18% (16/90) and 4% (6/150) in patients with and without pelvic node involvement at PET/CT respectively (19 vs 3% for no-TOF PET and 17 vs 5% for TOF PET subgroup). Conclusions In LACC, FN rate in PA lymph nodes detection is a clinical issue even for modern PET/CT, especially in patients with pelvic uptake. Surgical lymphadenectomy should be performed in case of negative PET/CT at PA level in these patients, while it could be discussed in the absence of pelvic uptake.

Upstaging by para-aortic lymph node dissection in patients with locally advanced cervical cancer: A systematic review and meta-analysis

“…In order to balance increased morbidity with the benefit of surgery, selecting eligible patients for PALN dissection based on prognostic factors of PALN involvement is of significant value. Several studies have confirmed that an increased risk of PALN involvement exists in patients with pelvic lymph node metastases [15,[18][19][20].…”

“…These articles were not part of the initial search result, because the title nor abstract included the 'lymphadenectomy' search term or synonyms. The final analysis included 16 studies [14,15,18,19,[25][26][27][28][29][30][31][32][33][34][35][36] reporting on 18 cohorts which were suitable for quantitative meta-analysis with pooling of upstaging outcomes.…”

“…Characteristics of the 18 cohorts within 16 studies included in the quantitative synthesis are outlined in Table 2. Six studies [15,25,27,29,30,35] (38%) were prospective and 10 studies [14,18,19,26,28,[31][32][33][34]36] (63%) were retrospective by design. All studies used laparoscopic procedures.…”

“…Surgical approaches were extraperitoneal or retroperitoneal in 4 studies [26,[29][30][31], transperitoneal in 2 studies [35,36] and not reported in 1 study [25]. In 9 studies [14,15,18,19,28,[31][32][33][34], both surgical approaches were used. In 9 studies [14,15,19,29,30,[33][34][35][36], the upper level of dissection was the left renal vein, which is considered the golden standard.…”

“…In 9 studies [14,15,18,19,28,[31][32][33][34], both surgical approaches were used. In 9 studies [14,15,19,29,30,[33][34][35][36], the upper level of dissection was the left renal vein, which is considered the golden standard. In 4 studies [26][27][28]31], the upper level of dissection was at least the inferior mesenteric artery.…”