Utility of 3T MRI in Women with IB1 Cervical Cancer in Determining the Necessity of Less Invasive Surgery

SIMPLE SUMMARY: 3T MRI can estimate more precisely the tumor volume of early cervical cancer than physical examination. Women with IB1 cervical cancer, which is invisible on 3T MRI, have no parametrial invasion so that parametrectomy can be skipped or minimized. Vagina invasion or lymph node metastasis is rare in these women so that vaginectomy or lymph node dissection can be performed less aggressively. Therefore, less invasive surgery can be one of the treatment options if IB1 cervical cancer is invisible on 3T MRI. ABSTRACT: Purpose: Cervical cancer that is invisible on magnetic resonance imaging (MRI) may suggest lower tumor burden than physical examination. Recently, 3 tesla (3T) MRI has been widely used prior to surgery because of its higher resolution than 1.5T MRI. The aim was to retrospectively evaluate the utility of 3T MRI in women with early cervical cancer in determining the necessity of less invasive surgery. Materials and methods: Between January 2010 and December 2015, a total of 342 women with FIGO stage IB1 cervical cancer underwent 3T MRI prior to radical hysterectomy, vaginectomy, and lymph node dissection. These patients were classified into cancer-invisible (n = 105) and cancer-visible (n = 237) groups based on the 3T MRI findings. These groups were compared regarding pathologic parameters and long-term survival rates. Results: The cancer sizes of the cancer-invisible versus cancer-visible groups were 11.5 ± 12.2 mm versus 30.1 ± 16.2 mm, respectively (p < 0.001). The depths of stromal invasion in these groups were 20.5 ± 23.6% versus 63.5 ± 31.2%, respectively (p < 0.001). Parametrial invasion was 0% (0/105) in the cancer-invisible group and 21.5% (51/237) in the cancer-visible group (odds ratio = 58.3, p < 0.001). Lymph node metastasis and lymphovascular space invasion were 5.9% (6/105) versus 26.6% (63/237) (5.8, p < 0.001) and 11.7% (12/105) versus 40.1% (95/237) (5.1, p < 0.001), respectively. Recurrence-free and overall 5-year survival rates were 99.0% (104/105) versus 76.8% (182/237) (p < 0.001) and 98.1% (103/105) versus 87.8% (208/237) (p = 0.003), respectively. Conclusions: 3T MRI can play a great role in determining the necessity of parametrectomy in women with IB1 cervical cancer. Therefore, invisible cervical cancer on 3T MRI will be a good indicator for less invasive surgery.