[Value of positron emission tomography-CT imaging combined with continual detection of CA125 in serum for diagnosis of early asymptomatic recurrence of epithelial ovarian carcinoma].

OBJECTIVE

To evaluate the value of positron emission tomography (PET)-CT imaging combined with continual detection of CA125 in serum for diagnosis of early recurrent ovarian epithelial carcinoma.

METHODS

Twenty six patients received PET-CT imaging, who were all diagnosed as primary epithelial ovarian cancer of stage II - IV and had complete remission after cytoreductive surgery and multiple courses of chemotherapy in Shandong Provincial Cancer Hospital. After a steady period, all patients experienced progressive rising of CA125 values 3 times in 2 months. But no positive lesion was found by CT, or although suspicious positive focus was found, the recurrent and (or) metastatic extent was not definite. Out of 26 patients, 16 were delivered rechemotherapy and (or) radiotherapy, and 10 received re-cytoreductive surgery.

RESULTS

(1) Of 26 patients, the value of CA125 was more than 35 kU/L in 17, and in 14 of 17, pelvic or abdominal cavity recurrence was diagnosed by CT and PET-CT, and 4 showed simultaneously distant metastasis on PET-CT. In the remaining 3 patients of which CT findings were negative, 2 had pelvic and abdominal cavity recurrence, and one had bone metastasis on PET-CT. Of 9 patients with progressive rising CA125 levels but the value was less than cut-off (< 35 kU/L), only 3 were found recurrence in pelvic and abdominal cavity by CT; however, all showed at least one suspicious recurrent or metastasis lesion on PET-CT. (2) Of 10 patients who received re-cytoreductive surgery, the value of CA125 was higher than cut-off in 6, and less in 4. Four were diagnosed as recurrence by CT and PET-CT, and 6 were only confirmed by PET-CT with 1 - 5 abnormal metabolic lesions found. (3) In 10 patients who received re-cytoreductive surgery, all suspicious positive lesions identified by CT were proved recurrence or metastasis by pathology, and abnormal metabolic lesions showed by PET-CT were all confirmed to be metastasis by postoperative pathology. (4) After 1 month of re-cytoreductive surgery, the value declined by 3.2 fold in 4 whose CA125 value was less than cut-off; in another 6, the value declined to less than cut-off in 4, and in one after 2 cycles of re-chemotherapy, but the remaining one patient had persistent CA125 values more than cut-off.

CONCLUSIONS

PET-CT could reveal recurrence and (or) metastasis which may be missed or could not be confirmed by routine diagnostic methods before clinical presentations. Combined with the continual detection of CA125, a high accuracy of diagnosis can be achieved. So it is an effective means for diagnosis of early recurrent ovarian cancer. The re-cytoreductive surgery can be more accurate and radical with the help of PET-CT.