FDG-positron emission tomography/computerized tomography for monitoring the response of pelvic lymph node metastasis to neoadjuvant chemotherapy for bladder cancer.

PURPOSE: We evaluated FDG-positron emission tomography/computerized tomography for monitoring the response of pelvic lymph node metastasis to neoadjuvant chemotherapy for bladder cancer. We compared this to contrast enhanced computerized tomography. MATERIALS AND METHODS: Included in study were 19 consecutive patients with lymph node positive bladder cancer who underwent FDG-positron emission tomography/computerized tomography and contrast enhanced computerized tomography before and after a median of 4 cycles (range 2 to 4) of neoadjuvant chemotherapy between September 2011 and April 2012. Metabolic response was assessed according to EORTC (European Organisation for Research and Treatment of Cancer) recommendations based on the change in FDG uptake on FDG-positron emission tomography/computerized tomography. Radiological response was assessed on contrast enhanced computerized tomography according to RECIST (Response Evaluation Criteria in Solid Tumors) 1.1. All patients underwent pelvic lymph node dissection. Histopathological evaluation served as the gold standard for the nodal response. RESULTS: Before neoadjuvant chemotherapy, hypermetabolic FDG uptake was seen in all 19 patients, which matched the lymph node metastasis. Evaluating the nodal response with positron emission tomography/computerized tomography was feasible in all patients. On histopathology 16 patients were responders, including 14 with a complete pathological response of the lymph nodes. Positron emission tomography/computerized tomography and contrast enhanced computerized tomography correctly distinguished responders from nonresponders (18 of 19 patients or 94.7% and 15 of 19 or 78.9%) and complete responders from patients with residual disease (13 of 19 or 68.4% and 12 of 19 or 63.2%, respectively). CONCLUSIONS: Although no definitive conclusions can be drawn from these preliminary data, positron emission tomography/computerized tomography appears feasible for evaluating the nodal response to neoadjuvant chemotherapy and distinguishing responders from nonresponders.

Impact of (18) F-fluorodeoxyglucose (FDG)-positron-emission tomography/computed tomography (PET/CT) on management of patients with carcinoma invading bladder muscle.

OBJECTIVE: To evaluate the clinical impact of (18) F-fluorodeoxyglucose (FDG)-positron-emission tomography/computed tomography (PET/CT) scanning, compared with conventional staging with contrast-enhanced CT imaging (CECT). PATIENTS AND METHODS: The FDG-PET/CT results of 96 consecutive patients with bladder cancer were analysed. Patients included in this study underwent standard CECT imaging of the chest and abdomen/pelvis <4 weeks before FDG-PET/CT. Based on the original imaging reports and recorded tumour stage before and after FDG-PET/CT imaging, the preferred treatment strategies before FDG-PET/CT and after FDG-PET/CT were determined for each patient using an institutional multidisciplinary guideline. One of the following treatment strategies was chosen: (i) local curative treatment; (ii) neoadjuvant/induction chemotherapy; or (iii) palliation. The changes in management decisions before and after FDG-PET/CT were assessed. RESULTS: The median (range) interval between CECT and FDG-PET/CT was 0 (029) days. In 21.9% of the patients, stage on FDG-PET/CT and CECT were different. Upstaging by FDG-PET/CT was more frequent than downstaging (19.8 vs 2.1%). Clinical management changed for 13.5% of patients as a result of FDG-PET/CT upstaging. In eight patients, FDG-PET/CT detected second primary tumours. This led to changes of bladder cancer treatment in another four of 96 patients (4.2%). All the management changes were validated by tissue confirmation of the additional lesions. CONCLUSIONS: FDG-PET/CT provides important additional staging information, which influences the treatment of carcinoma invading bladder muscle in almost 20% of cases. Patient selection for neoadjuvant/induction chemotherapy was improved and futile attempts at curative treatment in patients found to have metastases were avoided.

Induction chemotherapy followed by surgery in node positive bladder cancer.

OBJECTIVE: To evaluate the outcome and prognostic factors of patients with node positive bladder cancer (NPBC), who were eligible for surgery and treated with induction chemotherapy. METHODS: All consecutive patients with NPBC, who were treated with at least 2 cycles of induction chemotherapy and initially scheduled for surgery, between 1990 and 2012, were identified from an institutional bladder cancer database. Induction chemotherapy consisted of MVAC (methotrexate, vinblastine, doxorubicin, and cisplatin) or gemcitabine with cisplatin (Gem/Cis) or carboplatin (Gem/Carbo). RESULTS: One hundred forty-nine patients with NPBC (mean age, 60 years; range, 31-79) were treated with induction chemotherapy. Median cancer-specific survival (CSS) was 20 months and 5-year CSS 29.2%. In case of complete pathologic response to induction chemotherapy (N = 40; 26.8%), median CSS was 127 months and 5-year CSS 63.5% (P <.0001). Clinical and pathologic responses to chemotherapy were predictive parameters with respect to CSS and recurrence-free survival. Combined local and nodal responses resulted in a significantly better outcome, compared with isolated nodal or local response (P <.0001). CONCLUSION: Prognosis for NPBC remains poor despite the use of induction chemotherapy. Nevertheless, in the present series, 1 of 4 patients showed complete pathologic response to induction chemotherapy with subsequently a significant CSS benefit (median CSS 127 months and 5-year CSS 63.5%). Clinical and pathologic responses to chemotherapy are predictive parameters for outcome.

18F-fluorodeoxyglucose--positron emission tomography/computed tomography aids staging and predicts mortality in patients with muscle-invasive bladder cancer.

OBJECTIVE: To investigate the association between extravesical (18)F-fluorodeoxyglucose (FDG) avid lesions on FDG-positron emission tomography/computed tomography (PET/CT) and mortality in patients with muscle-invasive bladder cancer. METHODS: An international, bi-institutional cohort study of 211 patients with muscle-invasive bladder cancer who underwent staging CT and FDG-PET/CT imaging. On the basis of the presence of extravesical FDG-avid lesions suspicious for malignancy on PET/CT images, patients were divided into a PET/CT-positive and PET/CT-negative group. Data on staging and mortality were retrospectively analyzed from prospective databases. Kaplan-Meier analyses were performed to compare overall (OS) and disease-specific survival (DSS) between the groups. Multivariable Cox regression models were used to investigate the association between extravesical PET/CT lesions and mortality. Extravesical lesions suspicious for malignancy on conventional CT were included in the models. RESULTS: Of the 211 patients, 98 (46.4%) had 1 or more extravesical lesions on PET/CT, 113 (53.5%) had a negative PET/CT. Conventional CT revealed extravesical lesions in 51 patients (24.4%). Median follow-up was 18 months. Patients with a positive PET/CT had a significantly shorter OS and DSS (median OS: 14 vs 50 months, P = .001; DSS: 16 vs 50 months, P <.001). In multivariable analysis, the presence of extravesical lesions on PET/CT was an independent prognostic indicator of mortality (OS: hazard ratio = 3.0, confidence interval 95% 1.7-5.1). This association was not statistically significant for conventional CT (hazard ratio = 1.6 (95% confidence interval 0.9-2.7). CONCLUSION: On the basis of our results, the presence of extravesical FDG-avid lesions on PET/CT might be considered an independent indicator of mortality.

Detecting primary bladder cancer using delayed (18)F-2-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography imaging after forced diuresis.

OBJECTIVE: The aim of this study was to evaluate the use of delayed pelvic (18)F-2-fluoro-2-deoxy-D-glucose-positron emission tomography combined with the computed tomography (FDG-PET/CT) imaging, according to a standardized protocol including, pre-hydration and forced diuresis, for the detection of primary bladder cancer. MATERIALS AND METHODS: We evaluated 38 consecutive patients with primary cT1-4 bladder cancer. They underwent standard FDG-PET/CT followed by delayed pelvic imaging after administration of 20 mg furosemide intravenously and extra oral water intake of 0.5 L. Two observers, blinded for patient data, scored both image sets for tumor visibility using a 3-point ordinal scale: (1) negative; (2) indeterminate; (3) positive. FDG-PET/CT findings were compared with histopathology and/or follow-up imaging. RESULTS: The procedure was completed successfully in 37/38 patients and the reference standard revealed a bladder tumor in 26/37 patients. Delayed PET/CT images showed reduction of urinary bladder activity to (near) background levels in 17 of 37 cases (45.9%). Standard PET/CT detected hyper-metabolic bladder lesions in 15/37 patients (40.5%) of which 8 were indeterminate. Delayed FDG-PET/CT showed hyper-metabolic bladder lesions in 30/37 (81.1%) patients, of which 5 were indeterminate. When indeterminate lesions were considered positive, the sensitivity of standard and delayed PET/CT was 46% versus 88%, respectively. The specificity was 72% versus 36%. When indeterminate lesions were considered negative, the sensitivity of standard and delayed PET/CT was 23% and 85%. The specificity was 93% versus 73%. CONCLUSIONS: Our data suggest that delayed pelvic FDG-PET/CT imaging after forced detects more primary bladder tumors than standard FDG-PET/CT protocols. However, indeterminate bladder lesions on delayed PET/CT remain a problem and should be interpreted cautiously in order to avoid false positive results.

Catheter-assisted 18F-FDG-PET/CT imaging of primary bladder cancer: a prospective study.

OBJECTIVE: The purpose of this study was to prospectively investigate the value of a standardized 18F-fluorodeoxyglucose (18F-FDG)-PET/computed tomography (CT) protocol for imaging of primary bladder cancer, using standardized bladder flushing and filling. METHODS: We included 19 patients with cT1-4 bladder cancer. A Foley catheter was inserted before 18F-FDG injection. PET/CT imaging was performed according to four bladder protocols: (1) bladder empty; (2) bladder empty after flushing; (3) bladder filled with 50 ml saline; and (4) bladder filled with 100 ml saline. Tumour visibility was assessed and compared with histopathology or CT and cystoscopy. RESULTS: The procedure was successfully completed in 16 out of 19 patients. The reference standard revealed a bladder tumour in 16 out of 19 patients. Sensitivity of protocols 1 and 2 was 0.38 [95% confidence interval (CI), 0.16-0.64] compared with 0.63 (95% CI, 0.36-0.84) for protocols 3 and 4. CONCLUSION: Flushing and subsequent retrograde filling of the bladder results in the highest rate of tumour visualization and quantification. Flushing alone is inferior.

FDG-avid sclerotic bone metastases in breast cancer patients: a PET/CT case series.

Distant metastases from breast cancer most frequently occur in the skeleton. Although 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), with or without computed tomography (CT), is superior to bone scintigraphy for the detection of osteolytic bone metastases, it has been reported that sclerotic bone metastases frequently show no or only a low degree of FDG uptake on PET and PET/CT. Since both lytic and sclerotic metastases can occur in breast cancer patients, bone scintigraphy may remain of additional value in these patients. In this case series, we describe four breast cancer patients in whom FDG PET/CT has clearly visualized sclerotic bone metastases because of increased FDG uptake. Not so much the type of metastasis (sclerotic or lytic), but possibly the characteristics of the primary tumor or treatments prior to the FDG PET/CT scan might influence the degree of FDG uptake of bone metastases. The ability to detect sclerotic bone metastases based on increased FDG uptake supports the use of FDG PET/CT as a staging procedure in breast cancer patients, but knowledge of factors determining the visibility of bone metastases with FDG PET/CT is crucial.