Computed tomography, magnetic resonance imaging and FDG positron emission tomography in the management of vulvar malignancies

Objectives: To prospectively evaluate the value of CT or MRI (CT/MRI) and PET in the management of vulvar malignancies.

Methods: Abdominal and pelvic CT/MRI and whole-body ¹⁸ F-FDG (fluorodeoxyglucose) PET or PET/CT (collectively designated PET hereafter) were performed. Lesion status was determined by the pathological findings or clinical follow-up. The diagnostic efficacy was evaluated by receiver operating characteristic (ROC) curve analysis. The clinical impact of PET was determined on a per scan basis.

Results: Twenty-three patients were enrolled, and 38 PET examinations were performed. CT/MRI and PET studies were used for primary staging (n = 17), monitoring the response (n = 7) and restaging after recurrence (n = 14). In primary staging, there was no significant difference between CT/MRI and PET in detecting metastatic inguinal lymph nodes (ILN). CT/MRI was significantly more efficacious than PET in detecting pelvic lymph node (PLN) or distant metastasis (p = 0.007 by ROC per patient basis). PET findings resulted in two positive impacts and one negative impact for both primary staging and restaging.

Conclusions: False-positive PLN or distant metastasis PET findings are not uncommon, and hence should be interpreted with caution. PET can be supportive when metastatic ILN/PLN or distant metastasis is suspected on CT/MRI.

• CT/MRI has value in the management of vulvar malignancies.

Key Points: • False-positive metastatic PLN or distant metastasis PET findings are not uncommon.

• PET can be supportive when metastasis is suspected by CT/MRI.