Objective: We investigated the importance of metabolic parameters measured with 18F-fluorodeoxyglucose positron-emission tomography integrated with computed tomography (FDG-PET/CT) for predicting progression-free survival (PFS) and overall survival (OS) in cervical cancer with complete metabolic response (CMR) after chemoradiotherapy (ChRT). Methods: The clinical data and PET parameters including standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of 122 patients having CMR in post-treatment 18F-FDG-PET/CT delivered a median of 3.9 months after ChRT completion were analyzed. Results: With a median follow-up of 8.4 years, 55 patients (45%) presented with disease a median of 19.7 months after ChRT. For SUVp, MTVp, TLGp, SUVln, MTVln, and TLGp, the cut-off values for OS determined by receiver operating curve analysis were 15.8, 48.7 cm3, 552.3, 8.7, 7.0 cm3, respectively. All metabolic PET parameters were significant prognostic factors for OS and PFS in univariate analysis. International Federation of Gynecology and Obstetrics (FIGO) stage was predictive of both OS and PFS, while pelvic and/or para-aortic lymph node metastasis were predictive of OS only. In multivariate analysis, FIGO stage ≥IIB, MTVp ≥49.8 cm3, and TLGp ≥597.4 were predictive of worse OS. Advanced stage, presence of lymph node metastasis, higher TLGp, and larger MTVln were significant factors for poor PFS rates. Conclusion We found that advanced stage and higher TLGp values were significant predictors for poor survival and higher progression rates. Volumetric PET parameters could be used to predict treatment outcomes in patients with CMR after definitive ChRT.

BACKGROUND: The aim of this study was to develop and validate a multiplex real-time PCR assay for simultaneous identification and toxigenic type characterization of Clostridium difficile. METHODS: The multiplex real-time PCR assay targeted and simultaneously detected triose phosphate isomerase (tpi) and binary toxin (cdtA) genes, and toxin A (tcdA) and B (tcdB) genes in the first and sec tubes, respectively. The results of multiplex real-time PCR were compared to those of the BD GeneOhm Cdiff assay, targeting the tcdB gene alone. The toxigenic culture was used as the reference, where toxin genes were detected by multiplex real-time PCR. RESULTS: A total of 351 stool samples from consecutive patients were included in the study. Fifty-five stool samples (15.6%) were determined to be positive for the presence of C. difficile by using multiplex real-time PCR. Of these, 48 (87.2%) were toxigenic (46 tcdA and tcdB-positive, two positive for only tcdB) and 11 (22.9%) were cdtA-positive. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the multiplex real-time PCR compared with the toxigenic culture were 95.6%, 98.6%, 91.6%, and 99.3%, respectively. The analytical sensitivity of the multiplex real-time PCR assay was determined to be 103colonyforming unit (CFU)/g spiked stool sample and 0.0625 pg genomic DNA from culture. Analytical specificity determined by using 15 enteric and non-clostridial reference strains was 100%. CONCLUSIONS: The multiplex real-time PCR assay accurately detected C. difficile isolates from diarrheal stool samples and characterized its toxin genes in a single PCR run.
ADP Ribose Transferases/genetics ; Bacterial Proteins/*genetics ; Bacterial Toxins/*genetics ; Clostridium difficile/isolation & purification/*metabolism ; DNA, Bacterial/genetics/metabolism ; Enterotoxins/genetics ; Feces/*microbiology ; Humans ; Multiplex Polymerase Chain Reaction ; Prospective Studies ; Real-Time Polymerase Chain Reaction ; Triose-Phosphate Isomerase/genetics