Technetium-99m MIBI imaging in diagnosis of pelvic and abdominal masses in patients with suspected gynaecological malignancy.

BACKGROUND The aim of this study was to determine the diagnostic value of (99m)Tc MIBI planar dynamic scintigraphy in the diagnosis of gynaecological malignancies and to determine if it has a greater diagnostic accuracy than conventional ultrasound technique (US). MATERIAL AND METHODS A prospective trial was performed to assess the accuracy of (99m)Tc MIBI scintigraphy and ultrasound in 93 female patients (mean age 50, SD 16; range 17-82 years). Three readers assessed all the imaging independently and this was compared with histological examination in 89 cases and by clinical follow-up and correlative imaging for a minimum of 6 months in 4 patients. RESULTS There were 37 patients with cancer of gynaecological origin. There were in addition 56 benign lesions within the pelvis. (99m)Tc MIBI identified correctly 29 of the 37 malignant tumours localised within the pelvis and also correctly identified 21 of 23 metastases within the abdomen. Conventional US identified correctly 35 of the 37 tumours in the pelvis and 16 sites of metastases within the abdomen. The sensitivity and specificity of tumour detection within the pelvis for (99m)Tc MIBI were as follows: 78% and 70%; and for metastases within the abdomen 91% and 90%. The results of ultrasound for tumour detection within the pelvis: the sensitivity and specificity were 95% and 79% and for abdominal metastases 70% and 97%. Analysis of the index area under a receiver operator characteristic (ROC) curve in scintigraphy did not show a significant difference between both techniques in the diagnosis of pelvic lesions. There was however a significant increase in the sensitivity of scintigraphy (99m)Tc MIBI over US in metastases detection within the abdomen. CONCLUSIONS (99m)Tc MIBI cannot be recommended for the imaging of pelvic cancer alone, but it may be helpful in the identification of intra-abdominal spread of ovarian carcinoma and appears to offer significant advantages over ultrasound.