Cervical cancer: value of an endovaginal coil magnetic resonance imaging technique in detecting small volume disease and assessing parametrial extension.

BACKGROUND: Estimation of tumor volume by endovaginal magnetic resonance (MR) imaging is a better indicator of prognosis than FIGO stage in women with cervical cancer treated by standard modalities. However, the introduction of fertility conserving surgical techniques makes fresh demands upon imaging of these small tumors.
OBJECTIVE: To determine the sensitivity and specificity of endovaginal MRI in detecting small volume disease and assessing parametrial extension in uterine cervical cancer by comparing the findings with those at radical hysterectomy in order to establish its role in guiding the surgical decision-making process preoperatively.
METHODS: A retrospective study was performed in 119 patients who underwent endovaginal and external phased array MR imaging at 0.5 T or 1.5 T before radical hysterectomy. Tumor presence within the cervix and parametrial extension was noted on the endovaginal images. Histopathological findings were correlated with MR imaging results for all patients.
RESULTS: The sensitivity and specificity for detecting tumor by endovaginal MR imaging in the 119 patients were 96.9 and 59.0%, respectively. Thirty-six percent of tumors were <or=1 cm(3) in volume. For these, sensitivity and specificity for tumor detection were 87% and 65% respectively. For evaluation of parametrial status, sensitivity was 80%, and specificity was 91.3%. A cut-off MRI tumor volume of 5.2 cm(3) predicted histologically confirmed lymph node metastases with a sensitivity of 78.6% and specificity of 72.5%.
CONCLUSION: Endovaginal magnetic resonance imaging has high sensitivity in the preoperative staging of uterine cervical cancer even for tumors <or=1 cm(3). It is an invaluable technique in planning fertility-conserving or radical surgical treatment of early stage cervical cancer.