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Acute complicated pyelonephritis (ACP) is an upper urinary tract infection associated with coexisting urinary tract abnormalities or medical conditions that could predispose to serious outcomes or treatment failures. Although CT and magnetic resonance imaging (MRI) are frequently used in patients with ACP, the clinical value of 18F–fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) has not been systematically investigated. This single-center retrospective study was designed to evaluate the potential usefulness of FDG PET/CT in patients with ACP. Thirty-one adult patients with ACP who underwent FDG PET/CT were examined. FDG PET/CT imaging characteristics, including tracer uptake patterns, kidney volumes, and extrarenal imaging findings, were reviewed in combination with clinical data and conventional imaging results. Of the 31 patients, 19 (61%) showed focal FDG uptake. The remaining 12 study participants showed a diffuse FDG uptake pattern. After volumetric approximation, the affected kidneys were found to be significantly enlarged. Patients who showed a focal uptake pattern had a higher frequency of abscess formation requiring drainage. ACP patients showing diffuse tracer uptake patterns had a more benign clinical course. Seven patients had suspected extrarenal coinfections, and FDG PET/CT successfully confirmed the clinical suspicion in five cases. FDG PET/CT was as sensitive as CT in identifying the six patients (19%) who developed abscesses. Notably, FDG PET/CT findings caused a modification to the initial antibiotic regimen in nine patients (29%). FDG PET/CT may be clinically useful in the assessment of patients with ACP who have a progressive disease course.

Clinical outcomes of patients with resected oral cavity squamous cell carcinoma (OCSCC) chiefly depend on the presence of specific clinicopathological risk factors (RFs). Here, we performed a combined analysis of FDG-PET, genetic markers, and clinicopathological RFs in an effort to improve prognostic stratification. We retrospectively reviewed the clinical records of 2036 consecutive patients with first primary OCSCC who underwent surgery between 1996 and 2016. Of them, 345 underwent ultra-deep targeted sequencing (UDTS, between 1996 and 2011) and 168 whole exome sequencing (WES, between 2007 and 2016). Preoperative FDG-PET imaging was performed in 1135 patients from 2001 to 2016. Complete data on FDG-PET, genetic markers, and clinicopathological RFs were available for 327 patients. Using log-ranked tests based on 5-year disease-free survival (DFS), the optimal cutoff points for maximum standardized uptake values (SUV-max) of the primary tumor and neck metastatic nodes were 22.8 and 9.7, respectively. The 5-year DFS rates were as follows: SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7 (n = 77) versus SUVtumor-max

The question as to whether the regional textural features extracted from PET images predict prognosis in oropharyngeal squamous cell carcinoma (OPSCC) remains open. In this study, we investigated the prognostic impact of regional heterogeneity in patients with T3/T4 OPSCC.We retrospectively reviewed the records of 88 patients with T3 or T4 OPSCC who had completed primary therapy. Progression-free survival (PFS) and disease-specific survival (DSS) were the main outcome measures. In an exploratory analysis, a standardized uptake value of 2.5 (SUV 2.5) was taken as the cut-off value for the detection of tumour boundaries. A fixed threshold at 42 % of the maximum SUV (SUVmax 42 %) and an adaptive threshold method were then used for validation. Regional textural features were extracted from pretreatment (18)F-FDG PET/CT images using the grey-level run length encoding method and grey-level size zone matrix. The prognostic significance of PET textural features was examined using receiver operating characteristic (ROC) curves and Cox regression analysis.Zone-size nonuniformity (ZSNU) was identified as an independent predictor of PFS and DSS. Its prognostic impact was confirmed using both the SUVmax 42 % and the adaptive threshold segmentation methods. Based on (1) total lesion glycolysis, (2) uniformity (a local scale texture parameter), and (3) ZSNU, we devised a prognostic stratification system that allowed the identification of four distinct risk groups. The model combining the three prognostic parameters showed a higher predictive value than each variable alone.ZSNU is an independent predictor of outcome in patients with advanced T-stage OPSCC, and may improve their prognostic stratification.

The aim of this prospective study was to assess the usefulness of 18F-FDG PET/CT performed before and during treatment for predicting treatment failure in patients with advanced squamous cell carcinoma of the uterine cervix treated with concurrent chemoradiotherapy (CCRT). Patients with cervical squamous cell carcinoma, International Federation of Gynecology and Obstetrics stage III/IVA or positive pelvic or paraaortic lymph node (LN) metastasis without other distant metastasis on PET/CT entering a randomized trial of CCRT (AGOG 09-001) were eligible. PET/CT scans were performed at baseline, during week 3 of CCRT and 2 − 3 months after CCRT. PET/CT parameters were correlated with sites of failure and overall survival (OS). The resulting predictors developed from the study cohort were validated on two independent datasets using area under the curve values, sensitivities and specificities. With a median follow-up of 54 months for survivors, 20 (36 %) of the 55 eligible patients were proven to have treatment failure. Sites of failure were local in five, regional in 11, and distant in 11. Four predictors for local failure, three for regional failure, and four for distant failures were identified. After validation with two independent cohorts of 31 and 105 patients, we consider the following as clinically useful predictors: pretreatment metabolic tumour volume (MTV) and during-treatment cervical tumour MTV for local failure; during-treatment SUVnode (maximum standardized uptake value of LNs) for regional and distant failure, and during-treatment MTV for distant failure. During-treatment SUVnode (P = .001) and cervical tumour MTVratio (P = .004) were independent significant predictors of OS by stepwise Cox regression. PET/CT imaging before and during treatment is useful for predicting failure sites and OS, making tailored therapeutic modifications feasible with potential outcome improvement during primary therapy.

We prospectively investigated the potential usefulness of PET using a new tracer targeting integrin αvβ3 (termed RGD-K5) in patients with head and neck cancer (HNC) undergoing definitive concurrent chemoradiotherapy (CCRT). Newly diagnosed patients with locally advanced HNC scheduled for definitive CCRT were eligible. RDG-K5 PET and FDG PET scans were performed at three different time points (baseline, 2 weeks, and 3 months post-treatment). Nine patients completed all of the three scans, whereas two patients withdrew after two scans only. Uptake of both RGD-K5 and FDG generally decreased following CCRT. However, the observed decrease did not differ significantly between complete responders and non-responders. At 3 months post-treatment, the uptake of both RGD-K5 and FDG at the main tumors was significantly lower in those who achieved complete responses than in those with residual tumors. RGD-K5 PET has the potential to identify patients with incomplete responses to CCRT.

Small-cell cervical cancer (SCCC) is rare and prone to metastasize. We conducted a prospective study to evaluate the role of (18)F-FDG PET in the management of this aggressive malignancy.Patients with untreated primary, histologically confirmed SCCC were enrolled. (18)F-FDG PET (or PET/CT) was performed immediately after MRI or CT, for primary staging, monitoring response to treatment or restaging when there was suspicion of recurrence. The clinical impact of PET was determined on a scan basis.A total of 25 patients were recruited and 43 PET scans were performed. The PET images were obtained for primary staging (25 patients), monitoring response (10 patients) and restaging when there was suspicion of recurrence (8 patients). The median follow-up time in event-free patients was 109.3 months (range 97.5 - 157.7 months). A positive impact of PET was found in 8 (18.6 %) of the 43 scans, which included detection of additional regions of distal lymph node (LN) metastasis (one primary staging scan, two restaging scans), bone metastasis (two primary staging scans, one monitoring response scan), and exclusion of false-positive lesions on MRI (one primary staging scan, one restaging scan). On the other hand, one negative impact was recorded as one false-positive lesion on a restaging PET scan. One positive impact was noted for monitoring response (bone metastasis). The impact of three scans was indeterminate. The positive impact of down-staging in avoiding overtreatment but finding additional distal LN (except one on restaging) or bone metastases had no beneficial effect on long-term survival.The results of this preliminary study suggest that PET is useful in the management of SCCC. PET could have more value in detecting occult metastases if future novel therapies are able to offer better control of extensive SCCC.