Pre-operative MR Evaluation of Features That Indicate the Need of Adjuvant Therapies in Early Stage Cervical Cancer Patients. A Single-centre Experience

Objectives: This study compared the MR measurement of minimum uninvolved cervical stroma and maximum stromal invasion, and the detection of positive lymph nodes with the pathological results. In addition, tumour type and grade were correlated with nodal status and apparent diffusion coefficient (ADC) values.

Methods: Patients who underwent surgery and MR at our centre for early stage cervical cancer (FIGO IA1-IIB) were included. Data recorded included: age, date of MR, clinical FIGO (International Federation of Gynacology and Obstetrics) stage, histological type and grade, adjuvant therapy, pre-surgical conisation. MR evaluation included: measurement of the minimum uninvolved stroma, maximum thickness of stromal involvement, presence and site of positive pelvic lymph nodes, calculation of ADC values. Statistical analysis was performed to compare MR and pathological results. The agreement between MR and pathology in measuring depth of stromal invasion was analysed by Bland-Altman plot, calculating the limits of agreement (LoA).

Results: 113/217 patients underwent adjuvant therapies. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MR in evaluation of minimum thickness of uninvolved cervical stroma were 88%, 75%, 70%, 90% and 80%; the same values in evaluation of pelvic positive lymph nodes were 64%, 85%, 65%, 84% and 78%. The mean difference between MR and pathological results in measuring maximum depth of stromal invasion was -0.65mm (95% LoA: -9.37mm; 8.07mm). Depth of stromal invasion was strongly related to positive nodal status (p<0.001). ADC values (available in 51/217 patients) were not associated with the features assessed.

Conclusions: Pre-surgical MR is accurate (80%) in evaluating the minimum thickness of uninvolved cervical stroma; MR measurements of maximum depth of stromal invasion differed ±9mm from the pathological results in 95% of cases. Furthermore, a strong association was found between the depth of stromal invasion and the presence of positive lymph nodes, suggesting that inclusion of these measurements in the MR report might guide the choice of the best treatment option for early cervical cancer patients.