Metastasis detection with 18 FDG-positron emission tomography/computed tomography in gestational trophoblastic neoplasia: a report of 2 cases.

BACKGROUND

The imaging methods proposed by the International Consensus for the Diagnosis of Metastases in Trophoblastic Neoplasia are sufficient to stage the disease in most cases. However, there are 2 circumstances in which a more accurate imaging method is necessary: condemonstrate tl fusing images in conventional studies and persistent low 18 FDG-PET/CT human chorionic gonadotropin (hCG) values. Eighteen-fluoro-2-deoxyglucose-positron emission tomography/ computed tomography (18 FDG-PET/CT) can be helpful in these cases.

CASES

Case 1. A 51-year-old woman was referred to the Hospital Universitario de Caracas from another hospital with a diagnosis of cervical adenosquamous carcinoma. She complained of vaginal bleeding; clinical and sonographic evaluation demonstrated a tumor in the uterus and lower third of the vagina. A new histopathologic study was performed, and choriocarcinoma (CC) was diagnosed and staged as International Federation of Gynecologists and Obstetricians (FIGO) II:12 The im aging studies were confusing, so an 18 FDG-PET/CT was performed, showing multiple nodules in the lungs. Case 2. A 25-year-old woman was admitted with symptoms that mimicked those of ectopic pregnancy; a left salpingectomy was performed, with a histopathologic report of CC. It was classified as FIGO stage 11:4. Treatment consisted of chemotherapy, hysterectomy and 1 pelvic tumor resection. Two years after discontinuing therapy, persistent low hCG values were detected without evident metastatic disease demonstrated by CT. Eighteen FDG-PET/CT showed multiple pulmonary nodules.

CONCLUSION

Eighteen FDG-PET/CT seems to reveal metastases that are either confusing or not detected by other imaging techniques currently accepted in most gestational trophoblastic neoplasia protocols.