Metabolic imaging of ovarian tumors with carbon-11-methionine: a PET study.
This study examines the potential of 11C-methionine as a PET tracer in metabolic imaging of benign and malignant ovarian tumors.


METHODS
Four patients with one or two benign ovarian tumors (endometriomas or cystadenomas), two patients with a tumor of borderline malignancy and seven patients with ovarian cancer were studied with 11C-methionine and PET before laparotomy. CT or MRI were performed as a reference. Tracer uptake was quantitated by calculating tracer standardized uptake values (SUVs) and the kinetic influx constants (Ki values).


RESULTS
Benign or borderline malignant tumors did not accumulate 11C-methionine, whereas all carcinomas had significant uptake. The mean SUV of the primary carcinomas was 7.0 (s.d., 2.2) and the mean Ki was 0.14 min-1 (s.d., 0.1 min-1), but the distribution of tracer uptake was highly heterogenous in four of six tumors.


CONCLUSIONS
Ovarian cancer can be imaged with 11C-methionine and PET. This method also may be of value in the differential diagnosis between benign and malignant ovarian neoplasms. Due to physiological accumulations and methodological limitations, the value of 11C-methionine PET in the staging of ovarian cancer appears to be limited.
Department of Oncology and Radiotherapy, Turku University, Finland.
M
M
Lapela
S
S
Leskinen-Kallio
M
M
Varpula
S
S
Grénman
T
T
Salmi
K
K
Alanen
K
K
Någren
P
P
Lehikoinen
U
U
Ruotsalainen
M
M
Teräs
D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000000981:diagnostic imaging; D002250:Carbon Radioisotopes; D018269:Carcinoma, Endometrioid / Q000175:diagnosis / Q000000981:diagnostic imaging; D018284:Cystadenocarcinoma, Serous / Q000175:diagnosis / Q000000981:diagnostic imaging; D003537:Cystadenoma / Q000175:diagnosis / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D004715:Endometriosis / Q000175:diagnosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008715:Methionine; D008875:Middle Aged; D010049:Ovarian Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D002250:Carbon Radioisotopes; D008715:Methionine