ABSTRACT
OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy of fused fluoro-deoxy-D-glucose positron emission tomography/magnetic resonance mammography (FDG-PET/MRM) in breast cancer patients and to compare FDG-PET/MRM with MRM. METHODS: 27 breast cancer patients (mean age 58.9±9.9 years) underwent MRM and prone FDG-PET. Images were fused software-based to FDG-PET/MRM images. Histopathology served as the reference standard to define the following parameters for both MRM and FDG-PET/MRM: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for the detection of breast cancer lesions. Furthermore, the number of patients with correctly determined lesion focality was assessed. Differences between both modalities were assessed by McNemars test (p<0.05). The number of patients in whom FDG-PET/MRM would have changed the surgical approach was determined. RESULTS: 58 breast lesions were evaluated. The sensitivity, specificity, PPV, NPV and accuracy were 93%, 60%, 87%, 75% and 85% for MRM, respectively. For FDG-PET/MRM they were 88%, 73%, 90%, 69% and 92%, respectively. FDG-PET/MRM was as accurate for lesion detection (p = 1) and determination of the lesions' focality (p = 0.7722) as MRM. In only 1 patient FDG-PET/MRM would have changed the surgical treatment. CONCLUSION: FDG-PET/MRM is as accurate as MRM for the evaluation of local breast cancer. FDG-PET/MRM defines the tumours' focality as accurately as MRM and may have an impact on the surgical treatment in only a small portion of patients. Based on these results, FDG-PET/MRM cannot be recommended as an adjunct or alternative to MRM.
Subject(s)
Breast Neoplasms/diagnosis , Fluorodeoxyglucose F18 , Magnetic Resonance Imaging/methods , Mammography/methods , Radiopharmaceuticals , Tomography, Emission-Computed/methods , Adult , Aged , Female , Humans , Magnetic Resonance Imaging/standards , Mammography/standards , Middle Aged , Reference Standards , Sensitivity and Specificity , Tomography, Emission-Computed/standardsABSTRACT
AIM: Radiation exposure to the kidney limits therapy with radiometal labelled DOTATOC. This study evaluates the organic anion and cation transport (inhibitors: probenecid and cimetidine/dexamethasone) as well as diuresis (furosemide and mannitol) regarding renal uptake of [(111)In]DOTATOC. METHODS: One hundred eight male Fisher rats were injected with [(111)In]DOTATOC via the tail vein. Prior to activity injection a total of 84 rats underwent injection with probenecid vs. sodium chloride 0.9% (48 rats), cimetidine vs. dexamethasone vs. sodium chloride 0.9% (18 rats), and furosemide vs. mannitol vs. sodium chloride 0.9% (18 rats). Rats were sacrificed at predetermined time points up to 48 h after activity injection. Kidneys, adrenal glands, pancreas, spleen, blood, liver, and muscle were harvested and injected activity per gram tissue was determined. Autoradiographic images of the kidneys were acquired in a total of 24 rats. RESULTS: Probenecid led to a reduction in renal uptake by up to 30% while not significantly changing the activity accumulation in the other organs investigated. This reduction was attributable to the renal cortex (ratio cortex/medulla 1.72 vs. 1.99; p = 0.006). Cimetidine and dexamethasone had no effect in any of the organs. Furosemide led to a 44% increase in renal activity accumulation attributable to enhanced renal medullary uptake (ratio cortex/medulla 1.44 versus 1.69; p = 0.006). Mannitol had no effect on renal activity uptake. CONCLUSION: Inhibition of the organic anion transport by probenecid may help reduce renal uptake regarding therapy with radiometal labelled DOTATOC. The enhancing effect of furosemide may be unfavourable for therapy. The results must be confirmed by human studies.
