TY - JOUR T1 - Lymph node staging with a combined protocol of <sup>18</sup>F-FDG PET/MRI and sentinel node SPECT/CT: a prospective study in patients with FIGO I/II cervical carcinoma JF - Journal of Nuclear Medicine JO - J Nucl Med DO - 10.2967/jnumed.120.255919 SP - jnumed.120.255919 AU - Matthias Weissinger AU - Florin-Andrei Taran AU - Sergios Gatidis AU - Stefan Kommoss AU - Konstantin Nikolaou AU - Samine Sahbai AU - Christian la Fougere AU - Sara Yvonne Brucker AU - Helmut Dittmann Y1 - 2021/01/01 UR - http://jnm.snmjournals.org/content/early/2021/01/22/jnumed.120.255919.abstract N2 - Lymph node metastases (LNM) are present in a minority of patients with early stages of cervical carcinomas. As conventional imaging including PET/CT has shown limited sensitivity, systematic lymphadenectomies are often conducted for staging purposes. Therefore, the aim of this prospective study was to analyze the impact of 18F-FDG PET/MRI in addition to sentinel node (SLN) biopsy on lymph node status. Methods: 42 women with initial diagnosis of FIGO IA-IIB cervical carcinomas were included between 03/2016–04/2019. Each patient received preoperative whole body 18F-FDG PET/MRI (Biograph mMR®, Siemens Healthineers) and SLN imaging with SPECT/CT (Discovery 670 Pro®, GE Healthcare) after intracervical injection of 99mTc-labeled nanocolloid. Systematic Lymphadenectomy and SLN biopsy served as reference standard. Staging in PET/MRI was performed as a consensus of nuclear medicine and radiology experts. Results: One patient was excluded from surgical staging due to newly diagnosed liver metastases in PET/MRI. Overall prevalence of LNM in the remaining 41 patients was 29.3% (12/41). 5/12 patients with LNM solely had small metastases with maximum diameter ≤5mm. Interpretation of PET/MRI as a consensus of experts showed a specificity of 100% (29/29, 95%CI: 88.3-100%) for LNM-staging, but a low sensitivity of 33.3% (4/12, 95%CI: 12.8-60.9%). LN size was the most important factor for the detectability of metastases, since only LNM &gt;5mm could be identified by PET/MRI (sensitivity &gt;5mm: 57.1%; ≤5mm: 0%). Paraaortic LNM were evaluated accurately in 3/4 cases (16 patients with paraaortic LN removal). SLNs were detectable by SPECT/CT in 82.9% of the patients or 69.0% of hemipelvis. In cases with undetectable SLN in SPEC/TCT, malignancy rate was considerably higher (31.2% vs. 19.3%). The combination of PET/MRI and SLN SPECT/CT improved the detection of pelvic LNM from 33.3% to 75%. Conclusion: 18F-FDG PET/MRI is a highly specific N-staging method and improves LNM detection. Due to the limited sensitivity in frequently occurring small LNM, PET/MRI should be combined with sentinel node mapping. The proposed combined protocol helps to decide whether extensive surgical staging is necessary in patients with FIGO I/II cervical cancer. ER -