Impact of tumor histology on detection of pelvic and para-aortic nodal metastasis with 18F-fluorodeoxyglucose-positron emission tomography in stage IB cervical cancer.

OBJECTIVE: 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) detection of metastatic nodal disease is useful for guiding cervical cancer treatment but the impact of tumor histology is unknown. This study reports the detection of FDG avid pelvic and para-aortic lymph nodes in patients with early stage cervical cancer with squamous carcinoma and adenocarcinoma tumor histology.
METHODS: Patients with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IB1-2 cervical cancer who underwent pre-surgical FDG-PET between March 1999 and February 2018 were identified in a tertiary academic center database. All patients had radical hysterectomy with pelvic and para-aortic lymph node dissection. Detection of pelvic and para-aortic lymph nodes by FDG-PET versus surgical dissection was compared. FDG-PET sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined and stratified by tumor histology.
RESULTS: We identified 212 patients with early stage cervical cancer (84% FIGO IB1, 16% IB2) who underwent pre-surgical FDG-PET; 137 (65%) patients had squamous carcinoma and 75 (35%) patients had adenocarcinoma. PET/computed tomography was performed in 189 (89%) patients and 23 (11%) had PET only. Surgical dissection revealed positive pelvic and para-aortic lymph nodes in 25% and 3.3% of patients, respectively. For squamous carcinoma, sensitivity, specificity, PPV, and NPV of FDG-PET for pelvic nodal metastasis were 44%, 99%, 95%, and 78%, respectively. For adenocarcinoma, the corresponding results for pelvic nodal metastasis were 25%, 99%, 67%, and 92%, respectively. The overall values for sensitivity, specificity, PPV, and NPV of FDG-PET for para-aortic nodal metastasis were 29%, 99%, 67%, and 98%, respectively. DISCUSSION: Pelvic nodal metastasis was less likely to be detected by FDG-PET in patients with early stage adenocarcinoma than with squamous carcinoma. © IGCS and ESGO 2019. No commercial re-use. See rights and permissions. Published by BMJ.