Parametrial Involvement in FIGO Stage IB1 Cervical Carcinoma Diagnostic Impact of Tumor Diameter in Preoperative Magnetic Resonance Imaging

Background: In the surgical treatment for early-stage cervical carcinoma, it is important to identify preoperatively a low-risk group of patients as candidates for less radical surgery to avoid the morbidity associated with radical hysterectomy. The aim of this study was to evaluate the correlation between tumor diameter measured preoperatively using magnetic resonance imaging (MRI) and pathological prognostic factors in International Federation of Gynecology and Obstetrics (FIGO) stage IB1 cervical carcinoma. Methods: A total of 125 patients with FIGO stage IB1 cervical cancer were included in this study. Clinical records, pathology reports, and MRI findings were retrospectively reviewed. Results: Histological diagnosis was squamous cell carcinoma in 57 patients and nonsquamous cell carcinoma in 68 patients. All patients underwent preoperative evaluation by MRI within a median period of 13.5 days before surgery. The tumor diameter measured by MRI ranged from zero (no tumor detected) to 42 mm, with a median of 23 mm. Pathological prognostic factors included parametrial involvement, lymph node metastasis, deep stromal invasion, and lymphovascular space invasion. All these factors were found less frequently in patients with a smaller tumor diameter. Most notably, parametrial involvement was seen in none of the patients with tumors 20 mm or less and was detected only in patients with tumors greater than 20 mm (P = 0.01). Conclusions: In the FIGO stage IB1 cervical carcinoma, the tumor diameter measured preoperatively by MRI correlates well with other pathological prognostic factors, especially with parametrial involvement. This finding suggests that the tumor diameter measured in preoperative MRI may serve as a strong predictor of parametrial involvement in FIGO stage IB1 cervical carcinoma, which can be used to select a candidate population for less radical surgery without the need for a cone biopsy before hysterectomy.