Accuracy of magnetic resonance imaging of inguinofemoral lymph nodes in vulval cancer.

Inguinofemoral lymphadenectomy contributes to the high morbidity related to surgical treatment of vulval cancer. The objective of this study was to assess the accuracy of magnetic resonance imaging (MRI) in predicting inguinofemoral lymph nodes metastasis in women with vulval cancer. We reviewed the clinical, MRI, surgical, and pathologic findings of 59 women with vulval cancer who were treated at our institution from January 2000 to June 2004. Histology was available for 39 women who had undergone inguinofemoral lymphadenectomy. Clinical and MRI findings were compared with histology result to assess test accuracy. MRI had a positive likelihood ratio (LR+) of 4.8 (95% confidence interval of 2.7-8.6) and negative likelihood ratio (LR-) of 0.17 (0.06-0.49). It had a sensitivity of 85.7% (63.7-97), specificity of 82.1% (69.6-91.1), positive predictive value (PPV) of 64.3% (44.1-81.4), and negative predictive value (NPV) of 93.9% (83.1-98.7). Clinical examination had an LR+ of 6.1 (1.8-21.6) and LR- of 0.69 (0.5-0.96). It had a sensitivity of 35% (15.3-59.4), specificity of 94.3% (84.3-98.8), PPV of 70% (34.7-93.3), and NPV of 79.4% (67.3-88.5). Kappa statistics for interobserver and intraobserver agreement were 0.9091 and 0.8475, respectively. MRI assessment was accurate in predicting negative nodal status that is clinically useful in identifying women who can be spared inguinofemoral lymphadenectomy. It is noninvasive and is superior to clinical assessment. In clinical practice, this should encourage toward nodal sparing surgery, thus lowering surgical-related patient morbidity.