A prospective study of Tc-99m MIBI in the differential diagnosis of pelvic masses in female patients.
OBJECTIVE
This study evaluated the feasibility of Tc-99m MIBI scintigraphy in the differential diagnosis of pelvic masses in female patients before operation.


METHODS
Seventy-one patients with pelvic masses were studied with planar imaging over the abdomen and pelvis 5, 15, 30, and 60 minutes after injection of 740 MBq (20 mCi) Tc-99m MIBI. The uptake of the masses was graded, and other abnormal signs, such as intestinal involvement, lymph node involvement, or peritoneal fluid collection, were also considered in image interpretation. An exploratory laparotomy was performed 3 days to 2 weeks after imaging. The scintigraphic diagnosis was compared with that of computed tomography (CT), CA-125 measurement, and pathologic analysis.


RESULTS
Forty-one of 46 pelvic masses with no activity were proved benign. Eighteen of 25 with a fixed, focal uptake were malignant. In 19 of 23 masses, intestinal activity noted within 30 minutes was caused by metastases. All three cases with lymph node involvement and six cases with ascites were confirmed malignant. Combining focal uptake with intestinal involvement correctly indicated 22 of 23 malignant conditions before operation, whereas negative scans identified 41 of 48 benign lesions. Four of seven false-positive lesions had a higher cellular component. The diagnostic performance of Tc-99m MIBI is better than that of CT and CA-125 tests, because CT had eight false-positive and three false-negative results, whereas CA-125 had 12 false-positive and 3 false-negative results, respectively.


CONCLUSIONS
Tc-99m MIBI is useful for differentiating benign and malignant pelvic masses in female patients. A fixed focal uptake or intestinal uptake of the radiotracer suggests malignancy, with diagnostic sensitivity, specificity, accuracy, and positive and negative predictive values of 95.6%, 85.4%, 88.7%, 75.9%, and 97.6%, respectively, in the current prospective study.
Tian
J
J
Department of Nuclear Medicine, The Great-Wall Hospital, Beijing, Peoples Republic of China. tianjh@public.east.cn.net
Zhang
J
J
Jiao
L
L
Li
Y
Y
Cao
L
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D001201:Ascites / Q000000981:diagnostic imaging; D001202:Ascitic Fluid / Q000000981:diagnostic imaging; D001706:Biopsy; D018394:CA-125 Antigen / Q000032:analysis; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007414:Intestinal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D007422:Intestines / Q000000981:diagnostic imaging; D007813:Laparotomy; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008875:Middle Aged; D010386:Pelvic Neoplasms / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D014057:Tomography, X-Ray Computed
D018394:CA-125 Antigen; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi