Value of magnetic resonance imaging with an endovaginal receiver coil in the pre-operative assessment of Stage I and IIa cervical neoplasia.
To assess the value of high resolution endovaginal magnetic resonance images (MRI) of the uterine cervix in planning management of early cervical cancer. Prospective cross-sectional study. Specialist gynaecological oncology unit of a postgraduate teaching hospital. Thirty nine women aged 25-76 years old (mean 42.5 years) with invasive carcinoma Stage I or IIa of the cervix. A ring coil was positioned endovaginally around the cervix. Imaging was performed on a 1.0 T HPQ Vista or 0.5 T Asset (Picker, Highland Heights, Ohio, USA) using T1 weighted and T2 weighted sequences in transverse and sagittal planes with thin slices (2.5 mm) and small fields of view (12 cm). Tumour volumes were measured and any extension into adjacent organs and parametrium was noted. The patients were followed up after treatment and the outcome related to the MRI findings. There was one false positive and one false negative result among five Stage Ia patients being assessed for residual disease after cone biopsy or LLETZ. The MRI assessment of the size and distribution of the tumour was confirmed histologically in all 31 patients with Stage Ib or IIa disease who were treated surgically. One of these patients in whom no endocervical tumour was visible on MRI underwent radical trachelectomy. Three patients had radiotherapy as primary treatment. Patients with Stage Ib or IIa disease who had tumour volumes > 10 cm3 with early parametrial extension on MRI had a substantially worse prognosis at 24 months (disease-free survival 58.3% vs 95.5%, P = 0.003). High resolution MRI with an endovaginal coil allows precise measurement of tumour volume and identifies patients with small volume disease who might be considered for more conservative therapy. This technique also reveals early parametrial invasion that cannot be identified reliably by any other method. Early parametrial invasion in women with large tumours appears to have a very much worse prognosis.