Integrated analysis of 18F-FDG PET/CT improves preoperative lymph node staging for patients with invasive bladder cancer.

OBJECTIVES: Preoperative 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is controversial to assess lymph node (LN) staging in patients with invasive bladder cancer. We proposed to use the maximum standardized uptake value (SUVmax) associated with axial-based LN size to improve the detection of regional LN metastasis. METHODS: From May 2015 to May 2017, we prospectively included patients with urothelial bladder cancer who underwent radical cystectomy with extended pelvic LN dissection. All patients underwent preoperative 18F-FDG PET/CT staging before surgery. The gold standard comparator was the pathological examination of resected LNs. The data were reported on a regional per area- and patient-based model according to SUVmax values and axial-based LN size criteria. RESULTS: In total, 1012 LNs were identified in 61 patients with clinically localized invasive bladder cancer who underwent radical cystectomy and extended pelvic LN dissection. Loco-regional involvement of 24 LN areas was confirmed in 17 patients. In per area analysis, diagnostic accuracy of PET/CT and CT alone were respectively 84% and 78% (p = 0.039). On patient-based analysis, combined PET/CT correctly classified pelvic LN status in 5/61 (+ 8%) additional patients using optimal thresholds compared to CT alone, with accuracies of 82% and 74%, respectively (p = 0.13). CONCLUSION: Combining SUVmax and axial-based LN size criteria using 18F-FDG PET/CT improved the diagnostic accuracy for preoperative LN staging in patients with invasive bladder cancer, in per area analysis. KEY POINTS: • Combining metabolical and morphological features using18F-FDG PET/CT improves the detection of malignant lymph node in patients with bladder cancer. • 18 F-FDG PET/CT may help for initial staging of patients with muscle invasive bladder cancer.

Assessment of response to endocrine therapy using FDG PET/CT in metastatic breast cancer: a pilot study.

PURPOSE: The purpose of this pilot study was to assess whether outcome in metastatic or recurrent breast cancer patients is related to metabolic response to endocrine therapy determined by (18)F-FDG PET/CT. METHODS: The study group comprised 22 patients with breast cancer (age 58 ± 11 years, mean ± SD) who were scheduled to receive endocrine therapy. They were systematically assessed by PET/CT at baseline and after a mean of 10 ± 4 weeks for evaluation of response after induction. All patients demonstrated FDG-avid lesions on the baseline PET/CT scan. The metabolic response was assessed according to EORTC criteria and based on the mean difference in SUV(max) between the two PET/CT scans, and the patients were classified into four groups: complete or partial metabolic response, or stable or progressive metabolic disease (CMR, PMR, SMD and PMD, respectively). All patients were followed in our institution. RESULTS: Metastatic sites were localized in bone (n = 15), lymph nodes (n = 11), chest wall (n = 3), breast (n = 5), lung (n = 3), soft tissue (n = 1) and liver (n = 1). PMR was observed in 11 patients (50%), SMD in 5 (23%) and PMD in 6 (27%). The median progression-free survival (PFS) times were 20, 27 and 6 months in the PMR, SMD and PMD groups, respectively. PFS in the SMD group differed from that in the PMR and SMD groups (p < 0.0001). CONCLUSION: Metabolic response assessed by FDG PET/CT imaging in patients with metastatic breast cancer treated with endocrine therapy is predictive of the patients' PFS.

High and typical 18F-FDG bowel uptake in patients treated with metformin.

PURPOSE: This prospective and bi-centric study was conducted in order to determine the impact of antidiabetic treatments (AD) on (18)F-FDG bowel uptake in type 2 diabetic patients. METHODS: Fifty-five patients with previously diagnosed and treated type 2 diabetes mellitus (group 1) were divided in two subgroups: AD treatment including metformin (n=32; group 1a) and AD treatment excluding metformin (n=23; group 1b). The 95 patients without diabetes mellitus made up controls (group 2). (18)F-FDG uptake in small intestine and colon was visually graded and semi-quantitatively measured using the maximum standardized uptake value. RESULTS: (18)F-FDG bowel uptake was significantly increased in AD patients (group 1) as compared to controls (group 2) (p<0.001). Bowel uptake was significantly higher in AD patients including metformin (group 1a) as compared to AD patients excluding metformin (group 1b) (p<0.01), whose bowel uptake was not significantly different from controls (group 2). A metformin treatment was predictive of an increased bowel uptake in the small intestine (odds ratio OR=16.9, p<0.0001) and in the colon (OR=95.3, p<0.0001), independently of the other factors considered in the multivariate analysis. Bowel uptake pattern in the patients treated with metformin was typically intense, diffuse and continuous along the bowel, strongly predominant in the colon, in both the digestive wall and lumen. CONCLUSION: This study emphasizes that metformin significantly increases (18)F-FDG uptake in colon and, to a lesser extent, in small intestine. It raises the question of stopping metformin treatment before an (18)F-FDG PET/CT scan is performed for intra-abdominal neoplasic lesion assessment.

Impact of FDG PET-CT imaging on the decision making in the biologic suspicion of ovarian carcinoma recurrence.

OBJECTIVES: The aim of this prospective study was to evaluate the impact of integrated PET-CT on treatment management in ovarian carcinoma recurrence suspicion because of increased CA-125. METHODS: Twenty-nine patients (mean age=61 years), initially treated for ovarian carcinoma (FIGO stage I n=2, stage II n=3, stage III n=21 and stage IV n=3), presenting with increased CA-125 (mean=160 IU/ml, range 33-1930), underwent subsequently a CT and a PET-CT scans. The recurrence was acknowledged by the referring physicians for all patients. The impact of PET-CT on patient's management was evaluated by comparing the therapeutic decision mentioned respectively on the pre and post PET-CT questionnaires filled in by the oncologists. RESULTS: The CT scan was positive in 22/29 patients (76%) and negative in 7/29 patients (24%). The PET-CT scan was positive in 27/29 patients (93%) and negative in 2/29 (7%) patients. Five out of the seven patients with a negative CT scan had a positive PET-CT scan. In comparison to CT scan alone, the PET-CT scan modified the disease distribution for 16 patients (55%; p<0.001) in the following ways: more advanced disease (n=11), more limited disease (n=4), and different localizations (n=1). The assessment of pre and post PET-CT questionnaires showed a statistically significant change in the decision making for 10 patients (34%, p<0.0001). CONCLUSION: This questionnaire-based study showed that PET-CT imaging allows a better restaging than CT and induces a change in clinical management in over one third of patients with suspected ovarian carcinoma recurrence on increased CA-125.

In search of an unknown primary tumour presenting with cervical metastases: performance of hybrid FDG-PET-CT.

OBJECTIVES: In patients with cervical lymph node metastases from unknown primary tumour (UPT), the primary tumour is frequently localized in the head and neck area. Because the detection of the primary tumour is of importance to optimize the patient's management and allows a targeted therapy, the performances of hybrid positron emission tomography-computed tomography (PET-CT) using fluorodeoxyglucose (FDG) were evaluated in a retrospective study. METHODS: Thirty-eight consecutive patients with cervical lymph node metastases, and in whom the primary was not detected by the comprehensive diagnostic work-up including endoscopy and conventional imaging methods, were referred for a PET-CT scan. RESULTS: PET-CT was positive with an increased FDG focal uptake suggesting the potential primary site in 68% of patients (26/38), which guided the biopsies during a second rigid panendoscopy in 17 of these 26 patients: 13 primary tumours were then histologically proven. PET-CT showed distant lesions in three patients. It had treatment-related implications in 23/38 patients (60%), consisting of modification of radiation planning, surgery or abstention from surgery. CONCLUSION: Hybrid FDG-PET-CT is helpful for the detection of a potential head and neck primary tumour. Furthermore, hybrid FDG-PET-CT has the ability to diagnose occult or distant second tumour and metastatic disease and modify patient management.

Breast cancer recurrence diagnosis suspected on tumor marker rising: value of whole-body 18FDG-PET/CT imaging and impact on patient management.

BACKGROUND: Breast cancer recurrence is often suspected on tumor marker rising in asymptomatic patients. The value of fluorine-18 fluorodeoxyglucose (18FDG)-positron emission tomography/computed tomography (PET/CT) imaging to detect recurrence and its subsequent impact on patient management were retrospectively assessed. METHODS: PET/CT scans were performed on 228 asymptomatic patients (mean, 60.8 years; range, 30-91 years) presenting with rising CA 15-3 and/or CEA serum levels. RESULTS: PET/CT scans were positive in 181 patients (79.5%) and normal in 47 patients, whereas 187 true recurrences were diagnosed. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT imaging for detection of breast cancer recurrence were 93.6%, 85.4%, 96.7%, 74.5%, and 92.1%, respectively. When compared with the standard workup available in 67 patients, PET/CT imaging had a higher sensitivity and accuracy (94.5% vs 33% and 94% vs 48%, respectively). Recurrences were confirmed by pathology, conventional imaging techniques, or radiological and clinical follow-up beyond 1 year (mean, 34 months; range, 12-67 years) in 32, 130, and 25 patients, respectively. The diagnosis of recurrence led to a treatment modification in 123 patients (54%). CONCLUSIONS: 18FDG-PET/CT imaging is an efficient technique to detect breast cancer recurrence suspected on tumor marker rising in asymptomatic patients. It may thus contribute to improve patient management, providing an earlier diagnosis with complete whole-body staging as a "one-stop shop" procedure.