[Somatostatin receptor PET/CT (SSTR-PET/CT)]. / Somatostatinrezeptor-PET/CT.

The present guideline is focused on quality assurance of somatostatin receptor PET/CT (SSTR-PET/CT) in oncology patients. The document has been developed by a multidisciplinary board of specialists providing consensus of definitions, prerequisites, methodology, operating procedures, assessment, and standardized reporting. In particular, imaging procedures for the two most commonly used radioligands of human SSTR, i. e. 68Ga-DOTATOC and 68Ga-DOTATATE are presented. Overall, SSTR-PET/CT requires close interdisciplinary communication and cooperation of referring and executing medical disciplines, taking into account existing guidelines and recommendations of the European and German medical societies, including the European Association of Nuclear Medicine (EANM), German Society for Endocrinology (DGE), German Society for Nuclear Medicine (DGN) and German Society for Radiology (DRG).

Diagnostic value of diffusion-weighted imaging (DWI) for the assessment of the small bowel in patients with inflammatory bowel disease.

AIM: To evaluate diffusion-weighted imaging (DWI) compared to standard magnetic resonance imaging (sMRI) in the assessment of inflammatory lesions of the small bowel. MATERIALS AND METHODS: Two readers retrospectively analysed MRI images of the small bowel including DWI followed by capsule endoscopy (CE) and ileocolonoscopy (ICS) in 30 consecutive patients with a suspected or established diagnosis of inflammatory bowel disease. Small bowel CE and the combination of CE + ICS were used as the standards of reference. Inflammatory lesions of the small bowel detected at endoscopy were compared with the findings of (1) sMRI alone (MRI without DWI), (2) DWI alone, and (3) sMRI in combination with DWI (sMRI + DWI). The sensitivity, specificity, and accuracy were calculated for all three readouts. The results of the three readouts were compared with each other. RESULTS: Using CE + ICS as the standard of reference, the mean sensitivity and specificity for the detection of inflammatory lesions of the small bowel at sMRI were 55.2% and 99.5%, at DWI 60% and 99%, and at sMRI + DWI 70% and 99%. Interobserver agreement between the two readers was very good (k=0.87-0.95). Two lesions in different patients were only detected at DWI. CONCLUSION: DWI of the small bowel not only allowed for the detection of inflammatory lesions with high accuracy, but also enabled the identification of additional lesions that were not found using sMRI alone.

[Pancreatic neuroendocrine neoplasms]. / Neuroendokrine Neoplasien des Pankreas.

Pancreatic neuroendocrine neoplasms (NEN) account for 1-2% of all pancreatic neoplasms and represent a rare differential diagnosis. While some pancreatic NEN are hormonally active and exhibit endocrine activity associated with characteristic symptoms, the majority are hormonally inactive. Imaging techniques such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) or as combined PET/CT play a crucial role in the initial diagnosis, therapy planning and control. Endoscopic ultrasound (EUS) and multiphase CT represent the reference methods for localization of the primary pancreatic tumor. Particularly in the evaluation of small liver lesions MRI is the method of choice. Somatostatin receptor scintigraphy and somatostatin receptor PET/CT are of particular value for whole body staging and special aspects of further therapy planning.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany - Part 1: Gastrointestinal Tract.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract with all parenchymatous abdominal organs. In addition to the clinical and scientific further development of abdominal radiology, the education of radiologists within this core discipline of radiology is one of the major aims. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. This manuscript focuses on the most recent literature on the diagnosis of the stomach, small bowel, colon and rectum. The review with a focus on the most recent studies published by German radiologists concludes with a synopsis of mesenterial bleeding and ischemia followed by a critical appraisal of the current literature on conventional abdominal radiography. KEY POINTS: Based on recent literature and guidelines there is a change of paradigms regarding the diagnosis of esophagus and gastric cancer towards CT, which is considered equally to endosonography. For small bowel imaging in Crohn's disease ultrasound as well as MRI with a new focus on DWI are the most important imaging modalities scientifically. For colonic diagnosis virtual colonoscopy has replaced the conventional radiological methods. For staging of rectal carcinoma as well as for therapeutic stratification a high resolution MRI of the pelvis is of paramount interest. Multislice CT is considered the most important modality to assess mesenteric ischemia or bleeding.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany--Part 2: Abdominal Parenchymal Organs.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract as well as the parenchymal abdominal organs. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. The working group experts cover the most recent relevant studies concerning liver-specific contrast media with an emphasis on a new classification system for liver adenomas. Additionally studies regarding selective internal radiotherapy (SIRT) are reviewed. For the pancreas the most important tumors are described followed by an introduction to the most recently introduced functional imaging techniques. The manuscript concludes with some remarks on recent studies and concerning chronic pancreatitis as well as autoimmune pancreatitis. KEY POINTS: • Different subtypes of liver adenomas with different therapeutic consequences can be differentiated by MRI • Most recently published studies focus on liver imaging with extracellular liver specific contrast media as well as diffusion weighted imaging. They consider this new method having a high diagnostic potential. • For pancreatic neoplasm diagnosis diffusion--as well as perfusion--imaging is considered as a highly promising method.

[Relevance of Ablation Therapies for HCC: "A Real Bridging" for Liver Transplantation?]. / Stellenwert der ablativen Tumortherapie beim HCC: "eine reale Brücke" zur Lebertransplantation?

BACKGROUND: The utilisation of interventional ablation procedures in the context of bridging and downstaging plans for hepatocellular carcinomas before liver transplantation is increasing. The aim of the present study was to summarise current data for the application of bridging and downstaging procedures before liver transplantation. METHODS: The present study is based on an extensive investigation of the literature in PubMed. RESULTS of controlled trials, cohort studies, meta-analyses and reviews were included. RESULTS: Recommendations for the usage of bridging procedures for hepatocellular carcinomas within the Milan criteria and an expected waiting time of more than 6 months until transplantation depend on the size of the lesions and have a low level of evidence. After successful downstaging of hepatocellular carcinomas beyond the Milan criteria into the range of the Milan criteria liver transplantation is recommended with a low level of evidence, as well. CONCLUSION: Randomised controlled trials, clearly proving the success of bridging and downstaging procedures, are not available at the time and are not awaited for ethical reasons. Due to the uncomplicated application and low risk for therapy-associated complications, interventional procedures for bridging and downstaging are accepted and recommended.

Quantitative assessment of small bowel motility in patients with Crohn's disease using dynamic MRI.

BACKGROUND: Assessment of motility alterations by functional magnetic resonance imaging (MRI) contributes to improved evaluation of inflammatory bowel disease. The aim of the study was to quantify motility in inflammatory bowel segments and to compare motility alterations with MR-based parameters for activity of inflammation in Crohn's disease (CD). METHODS: Thirty consecutive patients with CD underwent bowel MRI which included a dynamic sequence for automatic generation of parametric maps facilitating quantification of bowel motility. Mean motility score (MMS) of small bowel segments with signs of inflammation was measured and compared with MMS of the whole gastrointestinal tract (GI tract). MRI-based score of inflammatory activity and lesion length were correlated with the MMS ratio of inflammatory small bowel lesion and whole GI tract. KEY RESULTS: Inflammatory bowel segments showed a mean value of MMSs of 1080, whereas the whole GI tract showed a mean value of MMSs of 2839 (p < 0.0001). Decrease in motility ranged between 20 and 87% in inflammatory bowel segments compared to the MMS of the whole GI tract. The MMS ratio of an inflammatory small bowel segment and whole GI tract showed negative correlation with MR activity score (r = -0.5921, p = 0.0003) and length of the lesion (r = -0.3495, p = 0.0462). CONCLUSIONS & INFERENCES: Quantitative assessment of motility alterations by means of motility scoring in small bowel segments affected by CD provides additional information on inflammatory activity.

Magnetic resonance imaging of the bowel: today and tomorrow.

Magnetic resonance imaging of the small bowel has been feasible for more than 15 years. This review is meant to give an overview of typical techniques, sequences and indications. Furthermore, newly evaluated promising techniques are presented, which have an impact on the advance of MR imaging of the small and large bowel.

Selective internal radiation therapy of hepatic tumours: is coiling of the gastroduodenal artery always beneficial?

AIM: To assess the effect of gastroduodenal artery (GDA) occlusion prior to selective internal radiation therapy (SIRT) with regards to arterial hepato-intestinal collateralization (HIC). MATERIALS AND METHODS: Six hundred and six patients were scheduled for SIRT between 2006 and 2012 at University Hospital Essen, Germany. Digital subtraction angiography (DSA) followed by administration of 99m-technetium labelled human serum albumin microspheres ((99m)Tc-HSAM) and single-photon emission computed tomography combined with computed tomography (SPECT/CT) was initially performed. Depending on vascular anatomy and hepatic tumour load, GDA coil embolization was considered. In subsequent (99m)Tc-HSAM rescans or therapeutic DSA, HIC and its consequences for SIRT were analysed. RESULTS: The GDA was occluded in 86 of 606 patients (14%). Twenty-two of these 86 patients did not undergo SIRT due to the patients' clinical status or SIRT contraindications. In 28 of the remaining 64 patients, newly apparent or reopened HIC were seen either at the site of the proximal GDA (n = 21) or in the periphery of the hepatic arteries (n = 7). In 25 of these 28 patients, the HIC could be occluded or the catheter position could be changed achieving a safe (90)Y application. However, due to the newly visible HIC in three of 28 patients, SIRT was regarded as unsafe and was abandoned. CONCLUSION: Coil embolization of the GDA may induce arterial hepato-intestinal collaterals. Although most of these collaterals do not impede (90)Y administration, SIRT may become unfeasible in specific occasions. Hence, segmental or lobar SIRT instead of a whole-liver approach with coiling of the GDA is recommended.

Hip imaging of avascular necrosis at 7 Tesla compared with 3 Tesla.

OBJECTIVES: To compare ultra-high field, high-resolution bilateral magnetic resonance imaging (MRI) of the hips at 7 Tesla (T) with 3 T MRI in patients with avascular necrosis (AVN) of the femoral head by subjective image evaluations, contrast measurements, and evaluation of the appearance of imaging abnormalities. MATERIALS AND METHODS: Thirteen subjects with avascular necrosis treated using advanced core decompression underwent MRI at both 7 T and 3 T. Sequence parameters as well as resolution were kept identical for both field strengths. All MR images (MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR) were evaluated by two radiologists with regard to subjective image quality, soft tissue contrasts, B1 homogeneity (four-point scale, higher values indicating better image quality) and depiction of imaging abnormalities of the femoral heads (three-point scale, higher values indicating the superiority of 7 T). Contrast ratios of soft tissues were calculated and compared with subjective data. RESULTS: 7-T imaging of the femoral joints, as well as 3-T imaging, achieved "good" to "very good" quality in all sequences. 7 T showed significantly higher soft tissue contrasts for T2w and MEDIC compared with 3 T (cartilage/fluid: 2.9 vs 2.2 and 3.6 vs 2.6), better detailed resolution for cartilage defects (PDw, T2w, T1w, MEDIC, DESS > 2.5) and better visibility of joint effusions (MEDIC 2.6; PDw/T2w 2.4; DESS 2.2). Image homogeneity compared with 3 T (3.9-4.0 for all sequences) was degraded, especially in TSE sequences at 7 T through signal variations (7 T: 2.1-2.9); to a lesser extent also GRE sequences (7 T: 2.9-3.5). Imaging findings related to untreated or treated AVN were better delineated at 3 T (≤1.8), while joint effusions (2.2-2.6) and cartilage defects (2.5-3.0) were better visualized at 7 T. STIR performed much more poorly at 7 T, generating large contrast variations (1.5). CONCLUSIONS: 7-T hip MRI showed comparable results in hip joint imaging compared with 3 T with slight advantages in contrast detail (cartilage defects) and fluid detection at 7 T when accepting image degradation medially.

Addition of diffusion-weighted imaging can improve diagnostic confidence in bowel MRI.

AIM: To evaluate whether the addition of diffusion-weighted imaging (DWI) in bowel abdominal magnetic resonance imaging (MRI) can improve diagnostic confidence. MATERIALS AND METHODS: One hundred and eleven consecutive patients with suspected or known inflammatory bowel disease (n = 59), tumour disease (n = 31), unspecific abdominal pain (n = 16), and suspected graft-versus-host disease (n = 5) underwent bowel MRI using a 1.5 T MRI machine. In addition to T2-weighted (T2W) and contrast-enhanced T1-weighted (CE-T1W) data, axial and coronal DWI sequences were collected (b = 50, 500, 1000). Diagnostic confidence for lesion detection with and without DWI was evaluated using a four-point Likert scale [1 = certainly no lesion(s), 2 = probably no lesion(s), 3 = probably lesion(s), 4 = certainly lesion(s)]. RESULTS: In 11 of 111 patients (10%), the diagnostic confidence was improved by DWI. In seven patients, readers changed their diagnosis from "probable" to "certain presence of lesions". In another four patients, lesions were diagnosed based on DWI, which were not delineated on CE-T1W and T2W imaging. CONCLUSION: DWI of the bowel can provide additional information to the reader and, therefore, improve diagnostic confidence. Hence, additional DWI should be integrated into a standard bowel MRI protocol.

Hepatic volume changes after lobar selective internal radiation therapy (SIRT) of hepatocellular carcinoma.

AIM: To assess volume changes of treated and non-treated liver segments after selective internal radiation therapy (SIRT) in patients with hepatocellular carcinoma (HCC) and compromised hepatic function due to cirrhosis over a time course of 12 months after SIRT. MATERIALS AND METHODS: All patients underwent SIRT of the right liver lobe with yttrium 90 (Y-90). Absolute volumes of the right liver lobe (RLV) and left liver lobe (LLV) were assessed using computed tomography (CT) before and 1, 3, 6, 9, and 12 months after SIRT. Changes at follow-up relative to baseline volumes were analysed ("normalized" volumes). Furthermore, the relative volume of the LLV [LLV/(RLV + LLV)] was calculated ("relative" volumes). For statistical analysis p < 0.05 was considered statistically significant. RESULTS: Forty-five HCC patients (36 men, nine women, mean age 71.9 years, range 55-90 years) were studied. The mean baseline RLV and LLV reached 1116 ml [95% confidence intervals (CI): 1006-1226 ml] and 601 ml (95% CI: 514-688 ml), respectively. At 6 months following radioembolization, the LLV increased by 30.8% (RLV -33.9%), with the relative LLV increasing from 35% (pre-radioembolization) to 50.5%. RLV further decreased and LLV increased 12 months after SIRT (nRLV -44.9%, nLLV +40.1%, relative LLV 56.5%). All changes were significant. CONCLUSION: Constraints of liver function after radioembolization of one liver lobe can be partially compensated through hypertrophy of the contralateral lobe. The rate of volumetric changes is the highest in the first 6 months following radioembolization. The present data can also be the basis to propagate radiation lobectomy for selected patients, simultaneously providing tumour control and future remnant liver hypertrophy before curative hemihepatectomy.

Cardiac MRI: T2-Mapping Versus T2-Weighted Dark-Blood TSE Imaging for Myocardial Edema Visualization in Acute Myocardial Infarction.

PURPOSE: To assess the diagnostic accuracy of T2 mapping for the detection of myocardial edema in acute myocardial infarction (AMI), and to compare this diagnostic accuracy with that of the current standard for myocardial edema imaging, which is T2w dark-blood TSE imaging. MATERIALS AND METHODS: 29 patients with AMI were examined at 1.5 T. For the visualization of myocardial edema, T2 maps, calculated from three T2w SSFP images, and T2w dark-blood TSE images were acquired in standard short- and long-axis views. Cine SSFP images were acquired for the analysis of left ventricular (LV) function and late gadolinium enhancement images (LGE) for the visualization of myocardial necrosis. The T2 maps as well as the T2w dark-blood TSE images were evaluated twice independently from the cine SSFP and LGE images. The presence or absence of myocardial edema was rated visually for each LV segment. As the standard of reference, the infarct zone was defined based on the cine SSFP and the LGE images. RESULTS: In this segment-based analysis, T2 mapping showed a sensitivity of 82 % and a specificity of 94 % for the detection of edema in the infarct zone. T2w dark-blood TSE imaging revealed a sensitivity of 50 % and a specificity of 98 %. T2 mapping showed a higher intra-rater agreement compared to T2w dark-blood TSE imaging (κ: 0.87 vs. 0.76). CONCLUSIONS: T2 mapping allows for the visualization of myocardial edema in AMI with a high sensitivity and specificity, and features better diagnostic accuracy in terms of a higher sensitivity compared to T2w dark-blood TSE imaging. Citation Format: • Naßenstein K, Nensa F, Schlosser T et al. Cardiac MRI: T2-Mapping Versus T2-Weighted Dark-Blood TSE Imaging for Myocardial Edema Visualization in Acute Myocardial Infarction. Fortschr Röntgenstr 2014; 186: 166 - 172.

7 Tesla MR imaging: opportunities and challenges.

The urge to increase magnetic field strength is driven by a number of potentially beneficial physical changes, possibly resulting in improved MR diagnostics. With the successful introduction of in-vivo ultra-high-field MR imaging, by means of 7 Tesla MRI, the focus of scientific research has been set on compiling different applications of brain and body imaging. This review presents an overview on the current status of 7 T MR imaging, investigating the opportunities as well as challenges associated with ultra-high-field MRI. Citation Format: • Umutlu L, Ladd ME, Forsting M et al. 7 Tesla MR Imaging: Opportunities and Challenges. Fortschr Röntgenstr 2014; 186: 121 - 129.

Bilateral hip imaging at 7 Tesla using a multi-channel transmit technology: initial results presenting anatomical detail in healthy volunteers and pathological changes in patients with avascular necrosis of the femoral head.

OBJECTIVE: To evaluate 7-T MRI of both hips using a multi-channel transmit technology to compensate for inherent B1 inhomogeneities in volunteers and patients with avascular necrosis of the femoral head. MATERIALS AND METHODS: A self-built, eight-channel transmit-receive coil was utilized for B1 modification at 7 T. Two shim modes (individual shim vs. CP2+ mode) were initially compared and the best shim result was used for all further imaging. Robustness of sequences against B1 inhomogeneities, appearance of anatomic and pathologic changes of the femoral heads of MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR sequences at 7 T were evaluated in 12 subjects on a four-point scale (1-4): four male volunteers and eight patients (seven males, one female) suffering from avascular necrosis treated by advanced core decompression. RESULTS: Successful MRI of both femoral heads was achieved in all 12 subjects. CP2+ mode proved superior in ten of 12 cases. DESS proved most robust against B1 inhomogeneity. Anatomical details (labrum, articular cartilage) were best depicted in PDw, MEDIC, and DESS, while for depiction of pathological changes PDw, DESS (0.76 mm(3)) and T1w were superior. CONCLUSIONS: Our initial results of ultra-high-field hip joint imaging demonstrate high-resolution, high-contrast images with a good depiction of anatomic and pathologic changes. However, shifting areas of signal dropout from the femoral heads to the center of the pelvis makes these areas not assessable. For clinical workflow CP2+ mode is most practical. Seven-Tesla MRI of the hip joints may become a valuable complement to clinical field strengths.

First-pass contrast-enhanced renal MRA at 7 Tesla: initial results.

OBJECTIVE: The aim of this study was to assess the feasibility of first-pass contrast-enhanced renal MR angiography (MRA) at 7 T. METHODS: In vivo first-pass contrast-enhanced high-field examinations were obtained in eight healthy subjects on a 7-T whole-body MRI. A custom-built body transmit/receive radiofrequency (RF) coil and RF system suitable for RF shimming were used for image acquisition. For dynamic imaging, gadobutrol was injected intravenously and coronal unenhanced, arterial and venous data sets using a T1-weighted spoiled gradient-echo sequence were obtained. Qualitative image analysis and assessment of artefact impairment were performed by two senior radiologists using a five-point scale (5 = excellent, 1 = non-diagnostic). SNR and CNR of the perirenal abdominal aorta and both main renal arteries were assessed. RESULTS: Qualitative image evaluation revealed overall high-quality delineation of all assessed segments of the unenhanced arterial vasculature (meanunenhanced 4.13). Nevertheless, the application of contrast agent revealed an improvement in vessel delineation of all the vessel segments assessed, confirmed by qualitative (meanunenhanced 4.13 to meancontrast-enhanced 4.85) and quantitative analysis (SNR meanunenhanced 64.3 to meancontrast-enhanced 98.4). CONCLUSION: This study demonstrates the feasibility and current constraints of ultra-high-field contrast-enhanced renal MRA relative to unenhanced MRA.

Neoadjuvant treatment improves capsular integrity and the width of the fibrous capsule of high-grade soft-tissue sarcomas.

BACKGROUND: Neoadjuvant treatment is thought to improve resection with margin-negative surgery in locally advanced soft-tissue sarcomas (STS). Treatment-induced alterations of the tumor peripheryhave not yet been microscopically evaluated. OBJECTIVE: This histopathological study compared limb STS with primary resection and those that had undergone neoadjuvant treatment, emphasizing microscopic changes of the fibrous capsule (FC) and reactive zone (RZ) after neoadjuvant treatment. PATIENTS AND METHODS: Patients with primary high-grade limb sarcomas (N = 76) which have not previously been treated were included. Of those, 37 were primarily resected and 39 were treated with one of the following neoadjuvant treatment modalities: 7x chemotherapy (CTX), 3x radiotherapy (RT), 15x isolated limb perfusion (ILP), 8x CTX + RT, and 6x CTX + ILP. Sizes of the FC and RZ were microscopically measured, and FC-integrity was documented. Histopathologic regression was expressed as a percent. RESULTS: Only 35.1% of untreated sarcomas showed an intact FC. We observed significantly higher capsular integrity after treatment (76.9%). Additionally, the average width of the FC (0.21 mm vs. 0.61 mm) and RZ (0.67 mm vs. 1.48 mm) increased significantly. The extent of histopathologic regression showed a correlation with capsular integrity and width. The combination of two treatment modalities (CTX + RT or ILP) showed strongest effects at the tumor periphery. CONCLUSIONS: Neoadjuvant treatment stabilizes the tumor periphery in STS (e.g., the capsule). Concerning local treatment strategies, these novel histopathologic insights might significantly influence the decision as to whether primary resection is advisable in advanced local soft-tissue sarcoma.

New look at renal vasculature: 7 tesla nonenhanced T1-weighted FLASH imaging.

PURPOSE: To investigate the feasibility of 7 Tesla (T) nonenhanced high field MR imaging of the renal vasculature and to evaluate the diagnostic potential of various nonenhanced T1-weighted (T1w) sequences. MATERIALS AND METHODS: Twelve healthy volunteers were examined on a 7T whole-body MR system (Magnetom 7T, Siemens Healthcare Sector) using a custom-built eight-channel radiofrequency (RF) transmit/receive body coil. Subsequent to RF shimming, the following sequences were acquired (i) fat-saturated two-dimensional (2D) FLASH, (ii) fat-saturated 3D FLASH, and a (iii) fat-saturated 2D time-of-flight MR angiography (TOF MRA). SNR and CNR were measured in the aorta and both renal arteries. Qualitative analysis was performed with regard to vessel delineation (5-point scale: 5 = excellent to 1 = nondiagnostic) and presence of artifacts (5-point scale: 5 = no artifact present to 1 = strong impairment). RESULTS: The inherently high signal intensity of the renal arterial vasculature in T1w imaging enabled moderate to excellent vessel delineation in all sequences. Qualitative (mean, 4.7) and quantitative analysis (SNR(mean) : 53.9; CNR(mean) : 28.0) demonstrated the superiority of TOF MRA, whereas 2D FLASH imaging provided poorest vessel delineation and was most strongly impaired by artifacts (overall impairment 3.7). The 3D FLASH MRI demonstrated its potential for fast high quality imaging of the nonenhanced arterial vasculature, providing homogeneous hyperintense vessel signal. CONCLUSION: Nonenhanced T1w imaging in general and, TOF MRA in particular, appear to be promising techniques for good quality nonenhanced renal artery assessment at 7 Tesla.

Whole-body FDG PET/CT is more accurate than conventional imaging for staging primary breast cancer patients.

PURPOSE: This retrospective study aimed (1) to compare the diagnostic accuracy of whole-body FDG PET/CT for initial breast cancer staging with the accuracy of a conventional, multimodal imaging algorithm, and (2) to assess potential alteration in patient management based on the FDG PET/CT findings. METHODS: Patients with primary breast cancer (106 women, mean age 57 ± 13 years) underwent whole-body FDG PET/CT and conventional imaging (X-ray mammography, MR mammography, chest plain radiography, bone scintigraphy and breast, axillary and liver ultrasonography). The diagnostic accuracies of FDG PET/CT and a conventional algorithm were compared. Diagnostic accuracy was assessed in terms of primary tumour detection rate, correct assessment of primary lesion focality, T stage and the detection rates for lymph node and distant metastases. Histopathology, imaging or clinical follow-up served as the standards of reference. RESULTS: FDG PET/CT was significantly more accurate for detecting axillary lymph node and distant metastases (p = 0.0125 and p < 0.005, respectively). No significant differences were detected for other parameters. Synchronous tumours or locoregional extraaxillary lymph node or distant metastases were detected in 14 patients (13%) solely by FDG PET/CT. Management of 15 patients (14%) was altered based on the FDG PET/CT findings, including 3 patients with axillary lymph node metastases, 5 patients with extraaxillary lymph node metastases, 4 patients with distant metastases and 3 patients with synchronous malignancies. CONCLUSION: Full-dose, intravenous contrast-enhanced FDG PET/CT was more accurate than conventional imaging for initial breast cancer staging due to the higher detection rate of metastases and synchronous tumours, although the study had several limitations including a retrospective design, a possible selection bias and a relevant false-positive rate for the detection of axillary lymph node metastases. FDG PET/CT resulted in a change of treatment in a substantial proportion of patients.