Prognostic role of maximum standardized uptake value of metastatic pelvic lymph node in patients with early stage cervical cancer for the prediction of distant metastasis

Objectives The aim of this study was to evaluate the role of maximum standardized uptake value (SUVmax) of metastatic pelvic lymph node measured by 18F-FDG-PET/CT in patients with early stage cervical cancer to predict future distant metastasis.

Methods A total of two hundred and thirteen patients with stage I-IIA cervical cancer who had underwent radical hysterectomy and pelvic lymphadenectomy from January 2007 to December 2011 were enrolled in this study. All patients underwent preoperative 18F-FDG-PET/CT scan at our institution. SUVmax, clinical and pathological data were retrieved from medical chart review.

Results The median follow-up period was 15.6 months. The SUVmax of 152 main tumor masses and 79 metastatic pelvic lymph nodes were analyzed, while it could not be analyzed in 52 patients due to absence of data. The median SUVmax was 8.75 with a range of 1 to 41 for the primary tumor. The median SUVmax was 5.95 with a range of 2 to 25 for the lymph node. When multiple lymph nodes were identified, only the lymph node with the highest SUVmax was used. Lymph nodes in whom later developed distant metastasis had higher SUVmax than those without developing distant metastais (3.2 versus 1.80, P < 0.0007). When the cutoff value of SUVmax for the primary tumor was set at 8.0 by receiver operating curve analysis, it was not associated with future distant metastasis (p=0.16). In contrast, when the cutoff value of SUVmax for the lymph nodes was set at 7.0, it showed significant association with future distant metastasis (P = 0.015).

Conclusions SUVmax of metastatic pelvic lymph nodes, not just lymph node metastasis itself, in patients with cervical cancer has a predictive role for future distant metastasis. It might help clinicians develop individualized treatment plan.