Abstract
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Objectives To evaluate the role of FDG-PET and PET/CT in staging, monitoring treatment efficacy and impact on patients management in GTN patients.
Methods 38 patients referred to our institution for GTN treatment between 2004 and 2011 were retrospectively enrolled. During staging all patients underwent to βHCG measurements, trans-vaginal ultrasound(TV-US), Chest X-ray, whole-body CT and PET/CT (n= 32) or PET (n= 6). 8 patients with positive extra-uterine PET/CT basal study were re-evaluated by a second PET/CT after βHCG normalization. PET(n=1) or PET/CT(n=3) were repeated in patients with βHCG resistance. TV-US and whole-body CT were used as standard of reference.
Results Staging: PET or PET/CT correctly identified uterine disease in 22/25 patients(88%), lung metastases in 12/19(63%) patients, lymphnodal involvement in 2/2 patients, ovarian metastases in 1/1, pancreatic metastases in 1/1 and liver metastases in 2/4(50%) patients. Restaging: in 8/8 patients with extra-uterine disease during staging, PET/CT documented complete response to therapy after βHCG normalization. PET and PET/CT identified the sites of persistent disease in all βHCG resistance patients (n=4), leading to tailored treatment: 2/4 patients underwent to second line chemotherapy and in 2/4 patients surgical removal of resistant disease (lung and uterus) was performed.
Conclusions During staging of GTN, PET has low sensitivity and high specificity. During treatment monitoring PET may detect a complete response to chemotherapy earlier than CT. In patients with resistant disease to chemotherapy PET may play a role in changing management and guiding treatment