Cervical Cancer: Role of MRI in Patient Management

Recent developments in MR techniques have magnified the added value of MRI in management of patients with cervical cancer. This presentation will briefly review the role of MR in clinical practice and discuss features of recent MR technique. Cervical cancer is the second most common cancer in women worldwide, and more than 80% of cases are found in developing nations. Cervical cancer is usually a slow-growing cancer, which is almost always caused by human papillomavirus (HPV) infection. The lesion begins on the surface, presenting as a preinvasive lesion for a long period, and gradually invades more deeply into the cervical stroma to evolve into invasive cervical cancer (stage IB or higher). Preinvasive lesions are identifiable by PAP smear and evaluated cinically by means of biopsy etc. MR imaging is basically used only for invasive cervical cancer. The staging and treatment of the uterine cancers are based on FIGO staging system, which is single most important rationale to provide universal statistics for epidemiology and therapeutic outcome. Although FIGO system has given a firm “no” to apply MR in staging cervical cancer, it finally updated in 2009 to recommend to include tumor size obtained from MR imaging or CT, based on the result of American College of Radiology Imaging Network/Gynecologic Oncology Group (ACRIN6651/GOG 183) clinical study. MRI can clearly visualize invasive cervical cancers, with detailed display of its extent. Lesions are displayed on T2-weighted images as a lesion with increased signal intensity compared to the adjacent cervical stroma. For demonstration of the tumor, MRI had an accuracy of 95% for invasive diseases. The important roles of MR are the evaluation of the tumor extent and the detection of lymph node (LN) metastases. In recent multi-institutional study in United States (ACRIN6651/GOG 183) visualization of cervical cancer was significantly better for MRI compared with multi-detector CT, although staging accuracy was similar between two modalities. When the detection of advanced stage (≥ IIB) were evaluated, sensitivity was 29%, 42%, and 53%, respectively for FIGO clinical staging, CT, and MRI; specificity was 99% for FIGO clinical staging, 82% for CT, and 74% for MRI. These results were poorer compared with previous studies, where staging accuracy of cervical cancer was reported to be superior for MRI (77-83%) to CT (63-69%) or US (70%). However, these studies showed the superiority of MRI over FIGO and the fact that FIGO staging was actually submitted after imaging such as CT or MRI examination. MR imaging has also shown sufficient confidence for diagnosing the absence of bladder or rectal invasion to safely obviate the need for invasive cystoscopic