Multiple and incidentally found cancers detected by 18F-FDG positron emission tomography/CT at one examination.

During the initial 8 months period of 18F-FDG PET/CT examination in our institution eleven cases of double cancers were detected. Eight cases were simultaneous second cancers and 3 cases are consecutive cancers. All cases are clinical ones and were referred from both outside hospitals and our own hospital. 18F-FDG PET/CT examination were utilized either to determine the extent of tumor or to stage the cancer or to detect recurrent tumors during the follow-up period. During the 8-months period 964 cases were studied. Therefore, the detection rates of simultaneous and consecutive cancers are 0.83% and 0.31% respectively. All together the detection rate of double cancer was 1.14%. To gain the general conception of double cancers the authors reviewed the autopsy registry of Japanese Society of Pathology during the four years from 2000 through 2003, and tabulated the combination of primary and second cancers. Frequently found combination of cancers were cancers of the thyroid, lung, stomach, liver, biliary tract, colon, rectum, and prostate. 18F-FDG PET/CT examination seems to be very useful in the management of cancer patients in terms of whole patient care.