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Purpose Radiolabelled somatostatin analogues targeting somatostatin receptors (SSR) are well established for combined positron emission tomography/computer tomography (PET/CT) imaging of neuroendocrine tumours (NET). [18F]SiTATE has recently been introduced showing high image quality, promising clinical performance and improved logistics compared to the clinical reference standard 68Ga-DOTA-TOC. Here we present the first dosimetry and optimal scan time analysis. Methods Eight NET patients received a [18F]SiTATE-PET/CT (250 ± 66 MBq) with repeated emission scans (10, 30, 60, 120, 180 min after injection). Biodistribution in normal organs and SSR-positive tumour uptake were assessed. Dosimetry estimates for risk organs were determined using a combined linear-monoexponential model, and by applying 18F S-values and reference target masses for the ICRP89 adult male or female (OLINDA 2.0). Tumour-to-background ratios were compared quantitatively and visually between different scan times. Results After 1 h, normal organs showed similar tracer uptake with only negligible changes until 3 h post-injection. In contrast, tracer uptake by tumours increased progressively for almost all types of metastases, thus increasing tumour-to-background ratios over time. Dosimetry resulted in a total effective dose of 0.015 ± 0.004 mSv/MBq. Visual evaluation revealed no clinically relevant discrepancies between later scan times, but image quality was rated highest in 60 and 120 min images. Conclusion [18F]SiTATE-PET/CT in NET shows overall high tumour-to-background ratios from 60 to 180 min after injection and an effective dose comparable to 68Ga-labelled alternatives. For clinical use of [18F]SiTATE, the best compromise between image quality and tumour-to-background contrast is reached at 120 min, followed by 60 min after injection.

Purpose Somatostatin analogues (SSA) are frequently used in the treatment of neuroendocrine tumours. Recently, [18F]SiTATE entered the field of somatostatin receptor (SSR) positron emission tomography (PET)/ computed tomography (CT) imaging. The purpose of this study was to compare the SSR-expression of differentiated gastroentero-pancreatic neuroendocrine tumours (GEP-NET) measured by [18F]SiTATE-PET/CT in patients with and without previous treatment with long-acting SSAs to evaluate if SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT. Methods 77 patients were examined with standardised [18F]SiTATE-PET/CT within clinical routine: 40 patients with long-acting SSAs up to 28 days prior to PET/CT examination and 37 patients without pre-treatment with SSAs. Maximum and mean standardized uptake values (SUVmax and SUVmean) of tumours and metastases (liver, lymphnode, mesenteric/peritoneal and bones) as well as representative background tissues (liver, spleen, adrenal gland, blood pool, small intestine, lung, bone) were measured, SUV ratios (SUVR) were calculated between tumours/metastases and liver, likewise between tumours/metastases and corresponding specific background, and compared between the two groups. Results SUVmean of liver (5.4 ± 1.5 vs. 6.8 ± 1.8) and spleen (17.5 ± 6.8 vs. 36.7 ± 10.3) were significantly lower (p < 0.001) and SUVmean of blood pool (1.7 ± 0.6 vs. 1.3 ± 0.3) was significantly higher (p < 0.001) in patients with SSA pre-treatment compared to patients without. No significant differences between tumour-to-liver and specific tumour-to-background SUVRs were observed between both groups (all p > 0.05). Conclusion In patients previously treated with SSAs, a significantly lower SSR expression ([18F]SiTATE uptake) in normal liver and spleen tissue was observed, as previously reported for 68Ga-labelled SSAs, without significant reduction of tumour-to-background contrast. Therefore, there is no evidence that SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT.

Benign so-called “brown tumors” secondary to hyperparathyroidism are a rare diagnostic pitfall due to their impressively malignant-like character in various imaging modalities. We present the case of a 65-year-old male patient with multiple unclear osteolytic lesions on prior imaging suspicious for metastatic malignant disease. Eventually, findings of 18F-FDG PET/CT staging and 99mTc-MIBI scintigraphy resulted in revision of the initially suspected malignant diagnosis. This case illustrates how molecular imaging findings non-invasively corroborate the correct diagnosis of osteitis fibrosa cystica generalisata with the formation of multiple benign brown tumors.

PET/CT using 68Ga-labeled somatostatin analogs (SSA) targeting somatostatin receptors (SSR) on the cell surface of well-differentiated neuroendocrine tumors (NET) represents the clinical reference standard for imaging. However, economic and logistic challenges of the 68Ge/68Ga generator-based approach have disadvantages over 18F-labeled compounds. Here, we present the first in-human data of 18F-SiFAlin-TATE, a novel 18F-labeled, SSR-targeting peptide. The aim was to compare the intra-individual biodistribution, tumor uptake, and image quality of 18F-SiFAlin-TATE to the clinical reference standard 68Ga-DOTA-TOC. Thirteen patients with NET staged with both 68Ga-DOTA-TOC and 18F-SiFAlin-TATE PET/CT have been included in this retrospective analysis. We compared the biodistribution in normal organs and tumor uptake of NET lesions by SUVmean and SUVmax measurement for tracers. Additionally mean and max tumor-to-liver (TLR) and tumor-to-spleen ratios (TSR) have been calculated by division of SUVmean and SUVmax of tumor lesions by the SUVmean of the liver and spleen, respectively. Additionally, image quality was visually rated by 5 blinded readers and an intra-class correlation (ICC) analysis on inter-observer agreement has been performed. Compared with 68Ga-DOTA-TOC, the biodistribution of 18F-SiFAlin-TATE showed somewhat higher, however, statistically not significant higher uptake in the liver, spleen, and adrenal glands. Significantly higher uptake was observed in the kidneys. Tumor uptake was higher in most tumor lesions with significantly higher uptake in common metastatic sites of NET including the liver (SUVmax 18.8 ± 8.4 vs. 12.8 ± 5.6; p

68Ga-DOTATOC PET/CT is a reliable imaging modality in the diagnosis and therapy planning of symptomatic meningiomas. We present a case of a 74-year-old woman where a supposed SSTR-positive sphenoid wing meningioma turned out to be a breast cancer metastasis. Our case shows that dural metastases from breast cancer might represent a clinical pitfall in 68Ga-DOTATOC PET/CT.

A 38-year-old woman presented for 18F-FDG PET/CT after multiple intra-abdominal surgical resections of a rare recurrent perivascular epithelioid cell tumor of the gastrointestinal tract. A solitary pelvic metastasis was detected, but surprisingly exhibited neither increased glucose consumption nor contrast enhancement on CT. Follow-up 18F-FDG PET/CT staging in the further disease course revealed multiple abdominal metastases, now, however, with markedly increased 18F-FDG uptake and intraoperatively correlating widespread peritoneal sarcomatosis. This case gives preliminary insight into monitoring of disease progression in metastatic perivascular epithelioid cell tumor, although the underlying pathophysiological bases for varying 18F-FDG uptake in PET/CT are not yet fully understood.

Tenosynovial giant-cell tumor also known as pigmented villonodular synovitis (PVS) is a benign but aggressive synovial proliferative disease most often affecting the knee joint. The mainstay of therapy is surgical resection. Due to a high rate of local recurrence, radiosynoviorthesis (RSO) is used as an adjuvant method in many cases. The aim of this study was to compare local recurrence (LR) rates after surgical synovectomy with and without adjuvant RSO. From 1996 to 2014, 37 surgical interventions were performed in 32 patients with diffuse pigmented villonodular synovitis of the knee. All patients underwent open synovectomy. Adjuvant radiosynoviorthesis (RSO) was applied in 26 cases, the control group consists of 11 cases without RSO. 9 (24%) lesions recurred within a median of 19 months after surgery. Of those 9 recurrences, 3 (17%) were seen in primary disease, 6 (32%) in already recurring cases (n.s.). In 26 RSO treated patients 6 (23%) recurred, in 11 patients of the control group, 3 (27%) recurred (n.s.). RSO is effective in PVS as also shown in some smaller reports in the literature. But surgery is still the mainstay of therapy. RSO is not a method of compensating for an insufficient surgical approach, but it may reduce the high rate of LR in patients with large and even recurrent diffuse forms of the disease.

Aim The aim of this study was to retrospectively analyze the prognostic value of combined Tc-99m-macroaggregated albumin (MAA) SPECT/CT and [F-18]-fluoroethylcholine (FEC) PET/CT before radioembolization for survival of patients with intermediate-stage hepatocellular carcinoma. Methods Twenty-four patients with known hepatocellular carcinoma Barcelona Clinic Liver Cancer stage B were eligible for this analysis. All patients were scheduled for radioembolization and received a pretherapeutic [F-18]FEC PET/CT scan as well as Tc-99m-MAA SPECT/CT for hepatopulmonary shunting. Laboratory and semiquantitative PET parameters and morphologic and metabolic (intersection) volumes of MAA and FEC were evaluated. Spearman correlation with overall survival, receiver operating curve analyses, univariate and multivariate Cox regression, and Kaplan-Meier-analysis was applied. Results All patients (5 female/19 male) are deceased within the observational period. Median survival was 395 days (51 days;range, 23-1122 days). The percentage of hypervascularized metabolically active tumor volume (vascularized tumor ratio;defined as high MAA and FEC uptake) correlated significantly with survival. Vascularized tumor ratio was a significant predictor in univariate and multivariate analyses (P = 0.026;hazard ratio, 11.65;95% confidence interval, 1.62-83.73;P = 0.015). Statistical significance was not reached by all other variables in multivariate analysis. Receiver operating curve analysis for 1-year survival revealed an area under the curve of 0.77 (P = 0.024) for vascularized tumor ratio. At a cutoff value of 9%, sensitivity, specificity, and positive and negative prediction were 83%, 67%, and 71% and 80% (P = 0.036). Patients with a higher tumor vascularization had a median survival of 274 +/- 80 versus 585 +/- 284 days (P = 0.015). Conclusion: s Hepatocellular carcinoma with high vascularization in metabolic active areas as assessed by combined FEC PET/CT and Tc-MAA SPECT/CT represents an unfavorable subgroup with reduced overall survival after radioembolization.

A 58-year-old man with history of resected rectal adenocarcinoma and synchronous unifocal pulmonary metastasis showed a solitary pulmonary relapse in follow-up CT after 3 years of complete remission. Resection was planned. Preoperative F-FDG PET/CT detected a high focal F-FDG uptake in the left main bronchus. Bronchoscopy showed a papillary endobronchial lesion that was biopsied. Histology confirmed distant colorectal metastasis. The initial treatment plan changed, and the recommendation for systemic therapy was made by a multidisciplinary oncology team. Endobronchial metastases are rare and difficult to detect in conventional CT. PET/CT is useful to uncover endobronchial metastasis, which may change patient management.

Background The extent of lymph node involvement is the most relevant prognostic factor in patients with penile cancer. Objective To prospectively analyze the diagnostic accuracy of 18F-FDG-PET/CT-scan in the assessment of inguinal lymph node involvement in patients with invasive penile carcinoma. Patients and methods Thirty-five patients with invasive penile carcinoma were staged prospectively by 18F-FDG-PET/CT-scan, and blindly evaluated by 2 nuclear medicine physicians. In total, lymph node involvement was assessed in 70 inguinal groins. Reference standard was either histology or clinical follow-up with a minimum of 31 months (mean: 48.4 months; range: 31–68 months). Results 18-FDG-PET/CT showed a sensitivity of 88.2% and a specificity of 98.1%. Positive predictive value (PPV) was 93.8%, while negative predictive value (NPV) was 96.3%. In two groins, metastasis of 5 and 7 mm were missed by PET/CT scan. Conclusion 18F-FDG-PET/CT is a promising staging tool in assessing the inguinal lymph node involvement of patients with penile carcinoma. Integration of PET/CT scanning into preoperative staging algorithms may avoid surgical staging in selected patients.

The aim of the present study was to identify prostate-specific antigen (PSA) threshold levels, as well as PSA velocity, progression rate and doubling time in relation to the detectability and localization of recurrent lesions with [18F]fluorocholine (FC) PET/CT in patients after radical prostatectomy. The study group comprised 82 consecutive patients with biochemical relapse after radical prostatectomy. PSA levels measured at the time of imaging were correlated with the FC PET/CT detection rates in the entire group with PSA velocity (in 48 patients), with PSA doubling time (in 47 patients) and with PSA progression (in 29 patients). FC PET/CT detected recurrent lesions in 51 of the 82 patients (62%). The median PSA value was significantly higher in PET-positive than in PET-negative patients (4.3 ng/ml vs. 1.0 ng/ml; p

Metastasis has been reported in the follow-up of up to 50% of uveal melanoma patients. Established oncological diagnostic modalities in tumor follow-up so far have limited sensitivity and specificity. The diagnostic value of combined positron emission tomography (PET)/computed tomography (CT) scans in the follow-up of patients with metastatic uveal melanoma was assessed. Eleven patients with successfully treated and one patient with suspected uveal melanoma underwent combined PET/CT scan. The indication for PET/CT scan was heterogenous and ranged from suspected metastatic choroidal melanoma in conventional imaging (n=3) to exclusion of further organ involvement before local therapy of liver metastases (n=5) and restaging after local or systemic therapy of metastases (n=4). PET/CT scan showed vital metastases from uveal melanoma in all patients (n=12). Ten patients showed vital hepatic metastases (83%), five osseous (42%), four lymphatic (33%), two pulmonary (17%), one adrenal (8%) and one had muscular metastases (8%). Six patients showed multiple organ involvement (50%). In addition, PET/CT scan correctly identified a primary intraocular tumor and ruled out pulmonary metastatic involvement with suspicious intrapulmonary findings in a CT scan and chest X-ray in two patients. It could also confirm an equivocal intrahepatic finding in an MRI scan as a vital metastasis. PET/CT scan is a very sensitive and specific tool for the detection and localization of metastatic disease in patients with uveal melanoma, assessing both anatomical morphology and cell metabolism in one single examination. With novel therapeutic approaches in evolution, PET/CT scanning can be of great importance for therapy planning and monitoring.

We aimed to evaluate (68)Ga-DOTATATE PET/CT for the early prediction of time to progression and clinical outcome after a first cycle of peptide receptor radionuclide treatment (PRRT) in a cohort of patients with well-differentiated neuroendocrine tumors.Thirty-three consecutive patients (22 men and 11 women; mean age +/- SD, 57.8 +/- 12.1 y) were investigated at baseline and again 3 mo after initiation of the first cycle of PRRT. (68)Ga-DOTATATE receptor expression was assessed using 2 measures of standardized uptake value (SUV): maximum SUV (SUV(max)) and tumor-to-spleen SUV ratio (SUV(T/S)). Percentage change in SUV scores after PRRT relative to baseline (DeltaSUV) was calculated. After completing 1-3 cycles of PRRT, patients entered the follow-up study, for estimation of time to progression. According to the Response Evaluation Criteria in Solid Tumors, progression was defined on the basis of contrast-enhanced CT. Clinical symptoms, as well as the tumor markers chromogranin A and neuron-specific enolase, were also recorded during regular follow-up visits.The 23 of 31 patients with decreased SUV(T/S) after the first PRRT cycle had longer progression-free survival than did the 8 of 31 patients with stable or increased scores (median survival not reached vs. 6 mo, P = 0.002). For the 18 of 33 patients showing a reduction in SUV(max), there was no significant difference in progression-free survival (median survival not reached vs. 14 mo, P = 0.22). Multivariate regression analysis identified SUV(T/S) as the only independent predictor for tumor progression during follow-up. In the 17 of 33 patients with clinical symptoms before PRRT, DeltaSUV(T/S) correlated with clinical improvement (r = 0.52, P0.05), whereas DeltaSUV(max) did not (r = 0.42, P = 0.10). Changes in the tumor markers (chromogranin A and neuron-specific enolase) did not predict DeltaSUV scores, clinical improvement, or time to progression.Decreased (68)Ga-DOTATATE uptake in tumors after the first cycle of PRRT predicted time to progression and correlated with an improvement in clinical symptoms among patients with well-differentiated neuroendocrine tumors; DeltaSUV(T/S) was superior to DeltaSUV(max) for prediction of outcome.

Vergleich der immunhistochemischen Expression des Somatostatinrezeptor- (SSTR-)Subtyps 2 mit der quantitativen 68Ga-DOTATATE-PET bei neuroendokrinen Tumoren (NET). Bei 27 Patienten mit metastasierten NET wurde die immunhistochemische Expression des SSTR-Typs 2 anhand einer Graduierung (0–3) bestimmt. Zusatzlich konnte bei 25/27 Patienten der Proliferationsindex Ki-67 ermittelt werden. Damit verglichen wurde die Speicherung von 68Ga-DOTATATE anhand des SUVmax (SUV „standardized uptake value“). NET ohne SSTR-Expression wiesen einen signifikant (p

The purpose of this study was to assess the diagnostic accuracy of whole-body MRI (WB-MRI) at 1.5 T or 3 T compared with FDG-PET-CT in the follow-up of patients suffering from colorectal cancer. In a retrospective study, 24 patients with a history of colorectal cancer and suspected tumour recurrence underwent FDG-PET-CT and WB-MRI with the use of parallel imaging (PAT) for follow-up. High resolution coronal T1w-TSE and STIR sequences at four body levels, HASTE imaging of the lungs, contrast-enhanced T1w- and T2w-TSE sequences of the liver, brain, abdomen and pelvis were performed, using WB-MRI at either 1.5 T (n = 14) or 3 T (n = 10). Presence of local recurrent tumour, lymph node involvement and distant metastatic disease was confirmed using radiological follow-up within at least 5 months as a standard of reference. Seventy seven malignant foci in 17 of 24 patients (71%) were detected with both WB-MRI and PET-CT. Both investigations concordantly revealed two local recurrent tumours. PET-CT detected significantly more lymph node metastases (sensitivity 93%, n = 27/29) than WB-MRI (sensitivity 63%, n = 18/29). PET-CT and WB-MRI achieved a similar sensitivity for the detection of organ metastases with 80% and 78%, respectively (37/46 and 36/46). WB-MRI detected brain metastases in one patient. One false-positive local tumour recurrence was indicated by PET-CT. Overall diagnostic accuracy for PET-CT was 91% (sensitivity 86%, specificity 96%) and 83% for WB-MRI (sensitivity 72%, specificity 93%), respectively. Examination time for WB-MRI at 1.5 T and 3 T was 52 min and 43 min, respectively; examination time for PET-CT was 103 min. Initial results suggest that differences in accuracy for local and distant metastases detection using FDG-PET-CT and WB-MRI for integrated screening of tumour recurrence in colorectal cancer depend on the location of the malignant focus. Our results show that nodal disease is better detected using PET-CT, whereas organ disease is depicted equally well by both investigations.

Introduction Appropriate diagnosis and therapy of coronary artery disease (CAD) frequently require information about both the functional and morphological status of the coronary artery tree. We hypothesized that the combination of multislice spiral CT (MDCT) angiography and myocardial perfusion SPECT (MPI) provides accurate allocation of perfusion defects (PD) to their determining coronary lesion. Methods Twenty patients (14 male, mean age 64±9.2 years) with known CAD were retrospectively studied. Gated MPI, CT angiography using a 16-detector CT scanner, and conventional coronary angiography (CCA) were performed in each patient. Reversible and fixed PD were subsequently allocated to their determining lesion separately by different observers for MDCT angiography and CCA. Results All patients showed significant CAD in CCA; six patients with one-, six with two-, six with three-, and two with four-vessel disease; three patients had bypass grafts; and five patients had prior myocardial infarction. Correct diagnosis of CAD was stated in 14 of 20 patients by MDCT angiography. Five reversible and five fixed PD were detected in 9 of 20 patients; one patient showed both reversible and fixed PD. Five of five reversible PD could be allocated to appropriate coronary artery stenoses in CCA. In MDCT angiography, five of five reversible PD were allocated to the same lesions; all lesions were rated as ≥50%. Conclusions The preliminary results of the present study show high accuracy for multislice spiral CT angiography to allocate reversible perfusion defects in myocardial scintigraphy to their determining coronary artery lesions in a small patient collective with known coronary artery disease.

Ischemia -modified albumin was regarded as an early marker of cardiac ischemia. On the other hand, it has been reported that increased ischemia-modified albumin levels are associated with unstable plaque processes like percutaneous coronary intervention, acute coronary syndrome or myocardial infarction. This prospective study aimed to investigate the role of ischemia-modified albumin in patients with peripheral vascular disease undergoing peripheral vascular intervention, a plaque-altering procedure without evidence of tissue ischemia. Peripheral vascular intervention was performed in 21 consecutive patients (68.2+/-13.3 years) with typical leg claudication and documented peripheral vascular disease. Additionally, 96 consecutive patients (66+/-12.0 years) undergoing routine exercise stress test for the exclusion of functionally relevant coronary artery disease were defined as controls. It was assumed that in the latter patients no unstable plaque-altering processes were present. Blood samples were drawn before, and 30 min and 3 h after, revascularization in the peripheral vascular intervention group, as well as before, and 30 min and 3 h after, maximum stress testing in the control group, respectively. Ischemia-modified albumin levels were analyzed using the albumin cobalt-binding test. In patients undergoing peripheral vascular intervention, ischemia-modified albumin increased from 116.6+/-19.1 U/ml at baseline to 132.0+/-19.3 U/ml 30 min after intervention (+14.4+/-15.7%, P

In der Diagnostik von initialen Veranderungen bei Rheumatoider Arthritis (RA) wird bisher neben der Projektionsradiographie (PR) im bilddiagnostischen Stufenkonzept die Magnetresonanztomographie (MRT) und die 3-Phasen-Skelettszintigraphie (3P-SZ) eingesetzt. Ziel dieser Studie war es, bei Patienten mit klinischem Verdacht auf eine RA die Wertigkeit der Handsonographie im Vergleich mit den etablierten Verfahren PR, MRT und 3P-SZ zu beurteilen. Bei 30 Patienten mit klinischem Verdacht auf das Vorliegen einer initialen RA wurden am selben Tag eine Sonographie der Hande, eine 3P-SZ, eine Niederfeld-MRT und eine PR der Hande durchgefuhrt. Alle Bilder wurden unterteilt in RA-typisch und nicht-RA-typisch. Als Goldstandard diente die nach jeweils 2 Jahren durchgefuhrte abschliesende klinische Diagnose des Rheumatologen. Insgesamt wurde vom Rheumatologen bei 19/30 Patienten die Diagnose einer initialen RA gestellt. Sonographisch konnte initial bei 14/19 Patienten die richtige Diagnose gestellt werden. Dem gegenuber ergab die PR nur bei 11/19 Patienten die richtige Diagnose. Erwartungsgemas hohe Sensitivitaten ergaben sich sowohl in der 3P-SZ (100%) als auch in der MRT (95%). Sonographisch lies sich ein unauffalliger Befund von entzundlich bedingten Veranderungen in den Sehnenscheiden der Sehnengleitlager und Gelenken der Hand unterscheiden. In der Hand eines erfahrenen Untersuchers stellt die Sonographie in der Initialdiagnostik der RA eine sinnvolle Untersuchungsmodalitat dar. Auch aufgrund der geringen Kosten ist die Sonographie somit eine echte Alternative zur PR.

The aim of this study was to evaluate 18F-fluoroethylcholine PET/CT as a metabolic imaging technique for the assessment of treatment response to 90Y radioembolization in patients with locally advanced hepatocellular carcinoma (HCC). Methods: Thirty-four HCC patients undergoing 78 18F-fluoroethylcholine PET/CT scans were identified for this study. Patients with initial or follow-up metastastic disease (n = 9) were excluded at the time point of the metastatic occurrence as well as patients with negative α-fetoprotein (AFP; n = 1), resulting in 24 patients and 57 scans that were eligible. All patients were scheduled for radioembolization and underwent 1 pretherapeutic and at least 1 posttherapeutic 18F-fluoroethylcholine PET/CT scan. Volume-of-interest analysis and volume-of-interest subtractions were performed. Maximum, mean, and peak standardized uptake value (SUV) analysis was performed, and the total intrahepatic 18F-fluoroethylcholine positive tumor volume (FEC-PTV) and tumor-to-background ratio were assessed. Statistical analysis was performed using a decreasing AFP of at least 20% as a standard of reference for therapy response including receiver-operating-characteristic analyses as well as descriptive and correlation analyses and multiple logistic regression. Results: Fourteen follow-up examinations were categorized as responder and 19 follow-up examinations as nonresponder. Absolute AFP values did not correlate with SUV parameters (P = 0.055). In receiver-operating-characteristic analyses, the initial mean SUV, Δmaximum SUV, and Δtumor-to-background ratio demonstrated the highest area under the curve, 0.84 (P = 0.009), 0.83 (P = 0.011), and 0.83 (P = 0.012), respectively, resulting in a positive prediction of 82%, 83%, and 91% at the respective cutoff points. When multiple logistic regression analysis was applied, this resulted in an area under the curve of 0.90 (P = 0.001), with a positive prediction of 94% and a sensitivity of 94%. The FEC-PTV did not reach significance in the presented dataset. Conclusion:18F-fluoroethylcholine PET/CT demonstrates a high potential for follow-up assessment in the context of radioembolization in patients with locally advanced, but nonmetastatic, HCC and initially elevated AFP, possibly enabling early therapy monitoring independent of morphology.

The aim of this study was to evaluate spiral multidetector computed tomography (MDCT) angiography using 64-slice technique in the detection of functionally relevant coronary artery stenoses (CAS).Thirty-eight patients (62+/-11 years, 28 men) with stable angina (26 with suspected and 12 with known coronary artery disease) were investigated using 64-slice MDCT angiography and gated myocardial perfusion SPECT (gated SPECT); a subgroup of 30 patients had additional invasive coronary angiography (ICA). Stenoses with luminal narrowing ofor=50% were defined as "significant" in MDCT angiography and ICA. MDCT angiography was compared with gated SPECT and the combination of gated SPECT plus ICA with respect to the detection of functionally relevant CAS.The sensitivity, specificity and negative and positive predictive values of MDCT angiography in detecting reversible perfusion defects on gated SPECT were 63%, 80%, 94% and 32%, respectively, in vessel-based analysis and 71%, 62%, 72% and 60%, respectively, in patient-based analysis. If only reversible perfusion defects on gated SPECT with CASor=50% on ICA were considered, the sensitivity, specificity and negative and positive predictive values were, respectively, 85%, 79%, 98% and 33% for vessel-based analysis and 85%, 59%, 83% and 61% for patient-based analysis.Sixty-four slice MDCT angiography failed to predict the functional relevance of CAS, but had a high negative predictive value in the exclusion of functionally relevant CAS in symptomatic patients.

The diagnostic accuracy of screening for bone metastases was evaluated using whole-body magnetic resonance imaging (WB-MRI) compared with combined fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) (FDG-PET-CT). In a prospective, blinded study, 30 consecutive patients (18 female, 12 male; 24-76 years) with different oncological diseases and suspected skeletal metastases underwent FDG-PET-CT as well as WB-MRI with the use of parallel imaging (PAT). With a 32-channel scanner, coronal imaging of the entire body and sagittal imaging of the complete spine was performed using T1-weighted and short tau inversion recovery (STIR) sequences in combination. PET-CT was conducted using a low-dose CT for attenuation correction, a PET-emission scan and diagnostic contrast-enhanced CT scan covering the thorax, abdomen and pelvis. Two radiologists read the MRI scans, another radiologist in combination with a nuclear medicine physician read the PET-CT scans, each in consensus. The standard of reference was constituted by radiological follow-up within at least 6 months. In 28 patients, 102 malignant and 25 benign bone lesions were detected and confirmed. WB-MRI showed a sensitivity of 94% (96/102), PET-CT exams achieved 78% (79/102; P0.001). Specificities were 76% (19/25) for WB-MRI and 80% (20/25) for PET-CT (P0.05). Diagnostic accuracy was 91% (115/127) and 78% (99/127; P0.001), respectively. Cut-off size for the detection of malignant bone lesions was 2 mm for WB-MRI and 5 mm for PET-CT. WB-MRI revealed ten additional bone metastases due to the larger field of view. In conclusion, WB-MRI and FDG-PET-CT are robust imaging modalities for a systemic screening for metastatic bone disease. PAT allows WB-MRI bone marrow screening at high spatial resolution and with a diagnostic accuracy superior to PET-CT.

The aim of this study was to assess the clinical benefit of combined [(18)F]FDG PET/CT in patients with malignant lymphoma as compared to separately performed PET and CT.Overall, 100 patients with Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) were included in this study. Co-registered PET/CT with [(18)F]FDG and contrast medium was performed in 50 consecutive patients with NHL (n=38) or HD (n=12) for initial staging (IS) (n=12) or re-treatment staging (RS) (n=38). Another 50 patients with NHL (n=32) or HD (n=18) underwent separate PET and CT investigations within a time frame of 10 days for IS (n=22) or RS (n=28). Lymphoma involvement was separately evaluated for seven different regions in each patient. Each patient had clinical follow-up evaluation for6 months. PET and CT data were analysed separately as well as side-by-side or in fused mode.In the PET/CT group, region-based evaluation for lymphoma involvement suggested a sensitivity/specificity of 85%/91% for CT, 98%/99% for PET and 98%/99% for PET/CT. In the PET and CT group, region-based evaluation showed a sensitivity/specificity of 87%/80% for CT, 98%/99% for PET and 98%/100% for PET and CT read side by side.PET was superior to CT alone and was improved further by side-by-side reading of both examinations. However, no significant difference was observed between PET/CT and separate PET and CT imaging in patients with lymphoma.

The objective of this study was to compare the accuracy in staging of various malignant tumors with whole-body magnetic resonance imaging (WB-MRI) using parallel imaging (PAT) and positron emission tomography-computed tomography (PET-CT).In a prospective study, 41 patients withoncologic diseases underwent [F]-fluoro-2-deoxy-D-glucose PET-CT for tumor staging and WB-MRI on a 32-channel-scanner with the use of PAT. Coronal T1w and STIR sequences at 5 body levels, axial HASTE imaging of the lung, and contrast-enhanced T1w sequences of the liver, brain, and abdomen were performed. TNM stage was assessed for both modalities in a separate consensus reading using histologic results and radiologic follow up within 6 months as the standard of reference.Three primary and 4 recurrent tumors were detected; one recurrent tumor was missed with WB-MRI. Sixty benign and 60 malignant lymph nodes were detected with a sensitivity of 98% and specificity of 83% for PET-CT and 80%/75% for WB-MRI, respectively. One hundred ninety-one malignant and 77 benign distant lesions were detected with a sensitivity/specificity of 82% for PET-CT and 96%/82% for WB-MRI. Accuracy for correct TNM staging was 96% for PET-CT and 91% for WB-MRI.WB-MRI and PET-CT are reliable imaging modalities for tumor staging. WB-MRI is highly sensitive in detecting distant metastases; PET-CT is superior in lymph node staging. PAT makes high-resolution WB-MRI feasible within less than 1 hour.

Background Myocardial single photon emission computed tomography (SPECT) is an established noninvasive method for the assessment of the functional significance of coronary artery stenoses. Intracoronary pressure measurements to determine fractional flow reserve (FFR) are increasingly performed during coronary angiography whenever an immediate decision regarding possible intervention is required. We hypothesized that the regional summed difference score (SDSr), reflecting reversible perfusion defects in the myocardial supply area of the FFR target vessel, would be the best predictor of an abnormal FFR in patients without prior myocardial infarction. Otherwise, a regional summed stress score (SSSr) should be the best predictor of an abnormal FFR in patients with prior myocardial infarction for different patient subgroups with coronary artery disease. Methods and Results In this study 50 patients (mean age, 65 ± 9.1 years; 18 women) with coronary artery disease and a 50% to 75% coronary stenosis (target vessel) were prospectively investigated. Dobutamine myocardial SPECT was performed as a single-day stress/rest protocol by use of technetium 99m sestamibi. For image interpretation, semiquantitative analysis was conducted by calculating SSSr and SDSr. Within 8 (±14.9) days, coronary angiography was performed and FFR was calculated by use of a pressure wire (normal FFR, ≥0.75). The mean FFR of all patients was 0.78 ± 0.14. Of 50 patients, 17 had an FFR lower than 0.75 in the target vessel. Receiver operating characteristic analysis identified an SDSr of 1 or greater and an SSSr of 3 or greater as the best threshold values for predicting ischemic FFR. Sensitivity, specificity, and negative and positive predictive values of SDSr and SSSr for the detection of FFR values lower than 0.75 in the target vessel were 80%, 76%, 53%, and 92%, respectively, and 70%, 93%, 78%, and 90%, respectively, in patients without prior myocardial infarction and 57%, 50%, 67%, and 40%, respectively, and 100%, 50%, 78%, and 100%, respectively, in patients with prior myocardial infarction. Weak correlation was found between the single values of FFR with both SDSr and SSSr for the different patient subgroups. Conclusion Among the dobutamine myocardial scintigraphy variables studied, SDSr was the best predictor of an abnormal FFR (cutoff value of 0.75) in patients without prior myocardial infarction. As assumed, SSSr was the best predictor of an abnormal FFR in patients with prior myocardial infarction in the target region.

Background The long-term outcome after heart transplantation (HTx) is essentially influenced by the occurrence and extent of cardiac allograft vasculopathy (CAV). Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) has been shown to be a useful and cost-effective non-invasive method in patients with known or suspected coronary artery disease, but its role in detecting CAV remains unclear. Aim To evaluate the accuracy and predictive value of dobutamine MPI in patients after HTx during a 12-month follow-up. Methods Seventy-seven patients (60 males, 17 females) underwent a total of 216 dobutamine MPI examinations over a period of 5 years. Examinations were obtained an average of 89 ′ 42 months after orthotopic HTx according to a 1 -day protocol using 9 9 m Tc-methoxyisobutylisonitrile ( 9 9 m Tc-MIBI) with and without attenuation correction. For the present study, findings from 77 MPI examinations (one MPI examination per patient) were analysed visually and semiquantitatively using a 20-segment model. Summed stress scores (SSS) and summed rest scores (SRS) were calculated and receiver operating characteristic (ROC) analysis was performed to detect optimum threshold values. Patients were followed up for 12 months and cardiac events were registered. Results Cardiac events were observed in 10 of the 77 patients. Good interobserver agreement was found for global visual and SRS-/SSS-based analysis (κ=0.74 and 0.66, respectively). SSS was superior to SRS in the detection of cardiac events. ROC analysis showed an optimized SSS threshold value of three. For predicting a cardiac event during the 12-month follow-up, global visual and semiquantitative analysis reached sensitivities of 90% and 90%, specificities of 72% and 88%, accuracies of 74% and 87%, positive predictive values of 32% and 53% and negative predictive values of 98% and 98%, respectively. The sensitivity, specificity, accuracy and positive and negative predictive values for MPI to detect clinically relevant coronary artery stenoses ( ≥ 50%) at conventional coronary angiography were 83%, 87%, 86%, 56% and 96%, respectively. Conclusions Non-invasive dobutamine MPI reliably identifies patients at risk for subsequent cardiac events in cases of CAV, with a high negative predictive value of 98% and an accuracy of 87%.

Aim: Aim of the study was to elaborate on the diagnostic role of Tc-99m sestamibi scintimammography (SMM) in the initial diagnosis of breast cancer, partially in comparison to MRI. The study presents an update of previously published data. Materials and methods: Out of a total of 464 scintimammograms findings of 252 studies were correlated with the histopathologic outcome. A subgroup of 68 patients with indeterminate preliminary diagnosis underwent additional MRI. SMM and MRI findings were correlated to the final hisopathological outcome. Results: Overall sensitivity and specificity for SMM were 84 and 85%, respectively. Depending on tumor size sensitivity ranged from 60% for stage pT1a,b carcinomas to 94% stage pT1c or higher. In the subgroup with indeterminate preliminary diagnosis sensitivity of SMM decreased to 76% which was lower as compared to MRI (84%). Specificity of SMM was 86% in this subgroup which was evidently higher as compared to MRI (51%). Conclusion: SMM has severe limitations in the diagnosis of small carcinoma and therefore should not be used for breast cancer screening. SMM can be used to further evaluate indeterminate or probably benign mammographic findings, especially when conventional mammography is inconclusive due to dense breast tissue.

ZusammenfassungIn der Initialdiagnostik bei rheumatoider Arthritis (RA) wer-den neben der Projektionsradiographie (PR) auch die Mag-netresonanztomographie (MRT) und die 3-Phasen-Skelettszintigraphie (3P-SZ) eingesetzt. Ziel dieser Studie war es, bei Patienten mit Verdacht auf RA die Wertigkeit der PR, der 3P-SZ und der MRT anhand von Verlaufsbeobachtun-gen über 2 Jahre zu beurteilen. Patienten, Methoden: Bei 42 Patienten wurden am selben Tag je eine 3P-SZ, Niederfeld-MRT und PR der Hände im dorsovolaren Strahlengang durchgeführt. Verlaufskontrollen erfolgten im jährlichen Abstand. Alle Bilder wurden von jeweils zwei erfahrenen Radiologen/ Nuklearmedizinern befundet und in rheumatypisch und nicht rheumatypisch unterteilt. Als Goldstandard diente die abschließende klinische Diagnose des Rheumatologen unter Berücksichtigung des Ritchie-articular-Index. Ergebnisse: Bei 24/42 Patienten wurde die Diagnose einer initialen RA gestellt. In der PR konnte bei 20/ 24Patienten imzeitlichen Verlauf die richtigeDiagnose gestellt werden. Demgegenüber wurde sowohl in der 3P-SZ als auch in der MRT bei allen 24 Patienten eine beginnende RA erkannt. Lediglich im Detektionszeitpunkt gab es Variationen mit insgesamt tendenziell späterer Diagnosestel-lung in der PR. Schlussfolgerung: In der bildgebenden Initialdiagnostik der RA ist die PR weiterhin als Verfahren der ersten Wahl anzusehen. In der weiterführenden Diagnostik von unklaren Befunden stellt die Niederfeld-MRT ein der 3P-SZ annähernd vergleichbar sensitives Verfahren dar. Trotzdem sollten – wenn möglich – aufgrund des geringen Field-of-view neben der 3P-SZ zur weiteren Abklärung unklarer Befunde Hochfeldtomographen bevorzugt werden.

Background: Aim of the study was to assess the value of scintimammography using Tc-99m sestamibi in the evaluation of tumor response to neoadjuvant chemotherapy. Material and Methods: Results were calculated for 9 patients undergoing neoadjuvant chemotherapy. Scintimammography using 740 MBq Tc-99m sestamibi was performed before, during and after chemotherapy, and sestamibi uptake was scored visually and semiquantitatively to evaluate tumor response. Results: In the case of complete response (n = 3) sestamibi uptake decreased 8 days after beginning neoadjuvant chemotherapy and normalized in the following course. Focal uptake decreased more slowly in patients with partial response (n = 3), who showed clear, persisting tracer accumulation after therapy. The patients without response (n = 3) showed a persisting high tumor activity even after chemotherapy was completed. Conclusions: The preliminary data suggest that in contrast to other imaging modalities scintimammography appears to yield early information regarding tumor response to neoadjuvant chemotherapy.

The aim of this study was to compare Tc-99m sestamibi scintimammography and dynamic contrast-enhanced MR imaging for the evaluation of indeterminate mammographic lesions. Forty patients with questionable mammographic findings were included in a prospective study. Thirty lesions were non-palpable. Mean lesion size was 1.6+/-0.7 cm (range 0.5-3.5 cm). Scintigraphy was considered as malignant when focal tracer accumulation was present. In MR imaging, lesions were classified according to their signal intensity time course: no enhancement or steady enhancement with low signal intensity (M0); steady enhancement with high signal intensity (M1); or rapid enhancement with plateau (M2) or washout (M3). Lesions classified as M2 or M3 were considered as suspicious for malignancy. Histopathologic evaluation was performed in 24 lesions. In 16 cases lesions were classified as benign from follow-up examinations (mean 24 months). Malignancies were proven in 14 patients (9 invasive carcinomas, 5 ductal carcinoma in situ). Sensitivity of MR imaging was 12 of 14 (86%) and sensitivity of scintimammography was 8 of 14 (57%). One of 26 benign lesions was false positive at MR imaging. Scintigraphy showed no false-positive results. In conclusion, magnetic resonance imaging provided high accuracy in evaluation of indeterminate mammographic lesions. Sensitivity of scintimammography was too low in detecting small carcinomas.

Die MRT spielt eine bedeutende Rolle bei der diagnostischen Abklarung von Skelettmetastasen. Prinzipiell kann man dabei 2 Anwendungsbereiche der MRT unterscheiden: Neben dem gelaufigen Einsatz zur Abklarung unklarer Befunde oder der gezielten hochauflosenden Darstellung ossarer Lasionen kann die MRT auch als primares Screeningverfahren zur Metastasensuche eingesetzt werden. Verglichen mit der Szintigraphie liegt hierbei der Hauptvorteil der MRT neben der hoheren Gesamtzahl an entdeckten Lasionen vor allem in der morphologischen Darstellung, die sowohl das Ausmas maligner Veranderungen aufzeigt als auch eine exakte Abgrenzung zwischen benignen und malignen Veranderungen ermoglicht. Da unklare szintigraphische Anreicherungen, vor allem bei Patienten mit dem klinischen Verdacht auf ossare Metastasierung, haufig zu einer aufwendigen Zusatzdiagnostik fuhren, denken wir, dass die Ganzkorper-Skelett-MRT nicht nur ein genaues, sondern auch kostengunstiges diagnostisches Verfahren in der Abklarung einer Skelettmetastasierung darstellen kann, wenn sich die Indikation zu dieser Untersuchung streng nach der Klinik und der therapeutischen Relevanz der Untersuchungsergebnisse richtet.

Zielsetzung: Ziel der Arbeit ist die Bestimmung der Wertigkeit der MRT fur die Unterscheidung benigner und pramaligner abdomineller Tumoren im Kindesalter. Methode: Bei 93 Kindern mit 69 malignen und 24 benignen abdominellen Raumforderungen wurden die MRT-Bilder retrospektiv ohne und mit Kenntnis der klinischen Befunde analysiert. Anhand der endgultigen Diagnose wurde die Aussagekraft der MRT in Bezug auf die korrekte Artdiagnose und die Unterscheidung zwischen benignen und malignen Tumoren uberpruft. Ergebnisse: Bei der alleinigen MRT-Analyse wurde fur die Diagnose „benigner Tumor” eine relativ niedrige Sensitivitat von 67% erzielt. Die Hauptursache hierfur waren unspezifische morphologische Unterscheidungskriterien, die zur falsch-negativen Diagnose eines Malignoms fuhrten. Zusammen mit den klinischen Befunden konnte die Sensitivitat auf 92% angehoben werden. Als Hauptkriterium fur die korrekte Artdiagnose zeigte sich bei den Malignomen die Organzugehorigkeit und bei den benignen Tumoren die Binnenstruktur. Schlusfolgerung: Im Rahmen der integrierten Diagnostik liefert die MRT einen wertvollen Beitrag zur Differentialdiagnostik kindlicher abdomineller Tumoren.

Background: Mammography is the gold standard of breast diagnostics. Completely new radiological developments are not to be expected in the near future. Thus, additive methods for mammography such as sonography, Doppler sonography, MRI, and scintigraphy are being increasingly employed. In this study, the mammography findings were compared with breast scintigraphy to define the limitations of both methods. The goal of the employing additional diagnostical methods besides mammography is to reduce the number of open biopsies. Patients and Methods: The histological findings of 1206 breast operations (in 1035 women) were analysed retrospectively. The indication to operate was based on a pathological mammographic or clinical finding. One hundred and forty patients with unclear mammographic findings were subjected to additional breast scintigraphy with 99 m Technetium prior to the planned operations. Results: In 619 operations, a malignant diagnosis was obtained (51.3%); the other 587 operations resulted in benign findings (48.7%). This is about a 1:1 ratio of benign to malignant final diagnosis from the operative breast biopsy. Histological benign findings included 242 (41.2%) fibrotic-cystic mastopathies and 168 (28.8%) fibroadenomas. These findings had been detected by mammography or clinical examination, but could not be clearly defined as benign and thus resulted in the necessity to operate. The additive implementation of breast scintigraphy resulted in a pre-operative diagnosis of 32 of 34 histologically confirmed mastopathic findings. The additive scintigraphy also resulted in a pre-operative diagnosis of 8 of 11 histologically confirmed fibroadenomas. The results of the breast scintigraphy thus had a higher specificity of 86% compared to normal mammography (specificity 47.9%); the sensitivity, however, was lower (79%) than that of mammography (90%). The results of breast scintigraphy for therapy monitoring of women with inflammatory breast cancer who received primary chemotherapeutic treatment correlated well with the clinical signs of remission and histological findings. Mammography and MRI failed to be of use in these cases. Conclusions: The enthusiastic reports from the USA concerning breast scintigraphy e.g. including suggestions on its implementation as a diagnostic method alone without mammography, cannot be confirmed as yet by German studies. Scintigraphy is still too new compared to the well-established mammography, so that experience an using this method must still be gained. However, breast scintigraphy is a useful complementary method for interdisciplinary breast diagnostics and may lead to a reduction of the necessity for ,,open biopsies.

Objective To evaluate the contrast medium enhancement and [ 18 F]-FDG uptake of liver metastases in patients suffering from colon or breast carcinoma prior to therapy. Material and methods PET/CT (Philips Gemini) with 200 MBq [ 18 F]-FDG and contrast medium was performed in 50 patients with colon and 39 patients with breast carcinoma. Lesions were characterized with the presence or the absence of a rim enhancement. The area size, the HU mean , HU max , SUV mean , SUV max of the lesion and of the liver were determined. The standard uptake values (SUVs) were correlated with the tumor markers CEA and CA 15-3. Results The lesions of colon carcinoma had HU mean -values of 70.7 ± 19.2 and of breast carcinoma 88.1 ± 21.7 ( p mean was 3.9 ± 1.3 versus 4.4 ± 1.9 in colon carcinoma ( p = 0.0182). Lesion of colon carcinoma with rim enhancement had a significantly higher SUV mean (4.4 ± 1.5 versus 3.6 ± 1.2; p = 0.001) and SUV max (6.7 ± 2.6 versus 5.1 ± 2.1; p = 0.000) than lesions without a rim enhancement. A good correlation between tumor markers and SUVs max could be found in both tumor groups; r = 0.83 ( p r = 0.82 ( p Conclusions The rim enhancement of the lesions in colon carcinoma indicate a significantly higher SUV.

The purpose of this study was to determine whether rotational C-arm computed tomography (CT) allows visualization of liver metastases and adds relevant information for radioembolization (RE) treatment planning. Technetium angiography, together with C-arm CT, was performed in 47 patients to determine the feasibility for RE. C-arm CT images were compared with positron emission tomography (PET)/CT images for the detection of liver tumors. The images were also rated according one of the following three categories: (1) images that provide no additional information compared with DSA alone; (2) images that do provide additional information compared with DSA; and (2) images that had an impact on eligibility determination for and planning of the RE procedure. In all patients, 283 FDG-positive liver lesions were detected by PET. In venous contrast-phase CT, 221 (78.1%) and 15 (5.3%) of these lesions were either hypodense or hyperdense, respectively. In C-arm CT, 103 (36.4%) liver lesions were not detectable because they were outside of either the field of view or the contrast-enhanced liver segment. Another 25 (8.8%) and 98 (34.6%) of the liver lesions were either hyperdense or presented primarily as hypodense lesions with a rim enhancement, respectively. With PET/CT as the standard of reference, venous CT and C-arm CT failed to detect 47 (16.6%) and 57 (20.1%) of all liver lesions, respectively. For RE planning, C-arm CT provided no further information, provide some additional information, or had an impact on the procedure in 20 (42.5%), 15 (31.9%) and 12 (25.6%) of patients, respectively. We conclude that C-arm CT may add decisive information in patients scheduled for RE.

Background: The aim of this was to evaluate FDG-PET (2-(fluorine-18)-fluoro-2-deoxy-D-glucose positron emission tomography) for assessment of residual tumour after primary chemotherapy of large and locally advanced breast cancer in comparison with conventional imaging modalities. Methods: In a prospective multicentre trial, 99 patients underwent one or more breast imaging modalities before surgery in addition to clinical examination, namely, FDG-PET (n=89), mammography (n=47), ultrasound (n=46), and magnetic resonance imaging (MRI) (n=46). The presence of residual tumour by conventional imaging, dichotomised as positive or negative, and the level of FDG uptake (standardised uptake values, SUV) were compared with histopathology, which served as the reference standard. Patients with no residual tumour or only small microscopic foci of residual tumour were classified as having minimal residual disease and those with extensive microscopic and macroscopic residual tumour tissue were classified as having gross residual disease. Results: By applying a threshold SUV of 2.0, the sensitivity of FDG-PET for residual tumour was 32.9% (specificity, 87.5%) and increased to 57.5% (specificity, 62.5%) at a threshold SUV of 1.5. Conventional imaging modalities were more sensitive in identifying residual tumour, but had a low corresponding specificity; sensitivity and specificity were as follows: MRI 97.6 and 40.0%, mammography 92.5 and 57.1%, ultrasound 92.0 and 37.5%, respectively. Breast MRI provided the highest accuracy (91.3%), whereas FDG-PET had the lowest accuracy (42.7%). Conclusions: FDG-PET does not provide an accurate assessment of residual tumour after primary chemotherapy of breast cancer. Magnetic resonance imaging offers the highest sensitivity, but all imaging modalities have distinct limitations in the assessment of residual tumour tissue when compared with histopathology.

Purpose To evaluate positron emission tomography (PET) using [18F]fluorodeoxyglucose (FDG) for prediction of histopathologic response early during primary systemic therapy of large or locally advanced breast cancer. Patients and Methods In a prospective multicenter trial, 272 FDG-PET scans were performed in 104 patients at baseline (n = 104) and after the first (n = 87) and second cycle (n = 81) of chemotherapy. The level and relative changes in standardized uptake value (SUV) of FDG uptake were assessed regarding their ability to predict histopathologic response. All patients underwent surgery after chemotherapy, and histopathologic response defined as minimal residual disease or gross residual disease served as the reference standard. Results Seventeen (16%) of 104 patients were histopathologic responders and 87 were (84%) nonresponders. All patients for whom baseline SUV was less than 3.0 (n = 24) did not achieve a histopathologic response. SUV decreased by 51% ± 18% after the first cycle of chemotherapy in histopathologic responders (n = 15), compared with 37% ± 21% in nonresponders (n = 54; P = .01). A threshold of 45% decrease in SUV correctly identified 11 of 15 responders, and histopathologic nonresponders were identified with a negative predictive value of 90%. Similar results were found after the second cycle when using a threshold of 55% relative decrease in SUV. Conclusion FDG-PET allows for prediction of treatment response by the level of FDG uptake in terms of SUV at baseline and after each cycle of chemotherapy. Moreover, relative changes in SUV after the first and second cycle are a strong predictor of response. Thus, FDG-PET may be helpful for individual treatment stratification in breast cancer patients.

Publisher Summary Penile cancer is a rare tumor entity in industrial countries and is frequently diagnosed late. Conventional radiologic imaging procedures have proven insufficiently robust in the assessment of lymphatic spread. Regarding functional PET imaging, the limited number of findings indicate that squamous cell-type penile carcinoma as well as its metastases are in principle amenable to PET or PET/CT imaging. Positron emission tomography is considered the gold standard for whole-body staging and the search for regional or distant metastases in a variety of malignant diseases. In the research, 18F-FDG-PET/CT showed promising first results in staging patients who suffer from penile cancer. However, independently of the underlying malignant disease, a known limitation of PET or PET/CT lies in the detection of micrometastases. While the resolution of modern PET and PET/ CT devices is significantly below 1 cm if the lesions exhibit high FDG uptake, it is generally not possible to detect micrometastases by means of PET imaging. A future implementation of PET and PET/CT into the diagnostic work-up of penile cancer patients may therefore help in selecting a stage for appropriate therapy and in improving follow-up. Combined PET/CT systems may eventually be favored over stand-alone PET scanners. The possibility of allocating a focus seen in PET to a certain anatomic region or structure can lead to an increase in diagnostic assertiveness. Furthermore, the additional morphologic information provided by CT and the use of exact image fusion may be particularly useful for planning surgery.

Breast cancer is the most frequent malignant disease in women worldwide and the second leading cause of cancer death in Western countries. In Germany, 46,000 women per year suffer from breast cancer. Of these women, 18,000 died from it [1]. In the USA, 211,240 new cases of breast cancer were diagnosed in women in 2004 and 40,410 died from it. The incidence has been increasing from 1940 until the present, to 110 per 100,000 women annually, and is higher in white women then in African-Americans. Statistics indicate that one in nine women will develop breast cancer during her lifetime [2].

Objective: The value of combined positron emission tomography (PET)/computed tomography (CT) in the follow-up of patients with breast cancer with elevated tumor markers but without proven metastases or local recurrence was assessed. Methods: Thirty-four women underwent PET/CT. The PET and CT images were first analyzed separately; fused findings were then interpreted, blinded to the results of the other modalities. The results of CT, PET, and PET/CT were compared with each other and correlated to the final diagnosis. Results: The PET/CT identified 149 malignant foci in 24 patients (71%). The CT detected 96 of these foci in 18 patients, whereas PET identified 124 foci in 17 patients. Differences between CT and PET were not significant. Differences between PET/CT and CT (P < 0.01) and PET/CT and PET (P < 0.01) were significant. The person-based sensitivity of PET/CT, PET, and CT was 96%, 88% and 96%, respectively. Specificity of PET/CT, PET, and CT was 89%, 78%, and 78%, respectively. Conclusions: The PET/CT is a valuable modality for the follow-up of patients with breast cancer and elevated levels of tumor markers.

The value and limitations of (11)C-choline PET and PET/CT for the detection of prostate cancer remain controversial. The aim of this study was to investigate the diagnostic efficacy of (11)C-choline PET and PET/CT in a large group of patients with suspected prostate cancer.Fifty-eight patients with clinical suspicion of prostate cancer underwent (11)C-choline PET (25/58, Siemens ECAT Exact HR+) or PET/CT (33/58, Philips Gemini) scanning. On average, 500 MBq of (11)C-choline was administered intravenously. Studies were interpreted by raters blinded to clinical information and other diagnostic procedures. Qualitative image analysis as well as semiquantitative SUV measurement was carried out. The reference standard was histopathological examination of resection specimens or biopsy.Prevalence of prostate cancer in this selected patient population was 63.8% (37/58). (11)C-choline PET and PET/CT showed a sensitivity of 86.5% (32/37) and a specificity of 61.9% (13/21) in the detection of the primary malignancy. With regard to metastatic spread, PET showed a per-patient sensitivity of 81.8% (9/11) and produced no false positive findings.Based on our findings, differentiation between benign prostatic changes, such as benign prostatic hyperplasia or prostatitis, and prostate cancer is feasible in the majority of cases when image interpretation is primarily based on qualitative characteristics. SUV(max) may serve as guidance. False positive findings may occur due to an overlap of (11)C-choline uptake between benign and malignant processes. By providing functional information regarding both the primary malignancy and its metastases, (11)C-choline PET may prove to be a useful method for staging prostate cancer.

The value of PET or PET/CT with (18)F-FDG for the staging of penile cancer has yet to be determined. The objective of this study was to investigate the pattern of (18)F-FDG uptake in the primary malignancy and its metastases and to determine the diagnostic value of (18)F-FDG PET/CT in the staging and restaging of penile cancer.Thirteen patients (mean +/- SD age, 64 +/- 14.0 y) with suspected penile cancer or suspected recurrent disease were examined with a Gemini PET/CT system (200 MBq of (18)F-FDG). The reference standard was based on histopathologic findings obtained at biopsy or during surgery.Both the primary tumor and regional lymph node metastases exhibited a pattern of (18)F-FDG uptake typical for malignancy. Sensitivity in the detection of primary lesions was 75% (6/8), and specificity was 75% (3/4). On a per-patient basis, sensitivity in the detection of lymph node metastases was 80% (4/5), and specificity was 100% (8/8). On a nodal-group basis, PET/CT showed a sensitivity of 89% (8/9) in the detection of metastases in the superficial inguinal lymph node basins and a sensitivity of 100% (7/7) in the deep inguinal and obturator lymph node basins. The mean +/- SD maximum standardized uptake value for the 8 primary lesions was 5.3 +/- 3.7, and that for the 16 lymph node metastases was 4.6 +/- 2.0.According to our results, the main indication for (18)F-FDG PET in the primary staging or follow-up of penile cancer patients may be the prognostically crucial search for lymph node metastases. With the use of a PET/CT unit, the additional information provided by CT may be especially useful for planning surgery. Implementing (18)F-FDG PET and PET/CT in future staging algorithms may lead to a more precise and stage-appropriate therapeutic strategy. Furthermore, invasive procedures with a high morbidity rate, such as general bilateral lymphadenectomy, may be avoided.

Compared with conventional coronary angiography, spiral multidetector CT (MDCT) angiography has delivered promising accuracy in the detection and validation of coronary lesions. Myocardial perfusion imaging (MPI) using SPECT is an established method for noninvasively assessing the functional significance of coronary stenoses and delivers valuable information for risk stratification. This retrospective analysis compared the accuracies of MDCT angiography and MPI in the detection of hemodynamically relevant lesions of the coronary arteries.Twenty-five patients with suspected or known coronary artery disease were studied. Electrocardiographically gated MPI and 16-MDCT angiography were performed. Myocardial perfusion images were analyzed by 2 experienced observers, and reversible and fixed perfusion defects were detected and allocated to their corresponding coronary vessels. For the evaluation of MDCT angiography, image quality was determined, and lesionsor = 50% and luminal narrowing50% were visually assessed and characterized by 2 independent observers unaware of the results of MPI.Ninety-nine coronary vessels were analyzed, and the quality of MDCT angiography images was assessed for 330 coronary segments. Coronary artery diameter was interpretable for 231 (70%) of 330 segments, whereas in 99 (30%) of 330 segments, vessel diameter could not be evaluated because of heavy calcifications, blurring, motion artifacts, or intracoronary stents. MDCT angiography detected stenosesor = 50% in 15 of 100 coronary arteries. Eight (53%) of 15 stenosesor = 50% showed reversible or fixed perfusion defects in the corresponding myocardial areas on MPI. Sensitivity, specificity, and negative and positive predictive values were 100%, 87%, 100%, and 29%, respectively, for the ability of MDCT angiography to detect reversible perfusion defects in the corresponding myocardial areas.MDCT angiography detected myocardial ischemia, as defined by reversible perfusion defects on MPI, with a positive predictive value of 29% in a nonselected study cohort. Compared with MPI alone, MDCT angiography added important morphologic information, but MPI remains mandatory for evaluating the functional relevance of coronary artery lesions.

Introduction: The treatment of Charcot neuroarthropathy in the feet of diabetic patients has undergone fundamental changes in the last few years. Formerly, treatment was almost exclusively limited to nonoperative measures; since the late 1990s, however, current practice has shifted to early, stage-appropriate surgical therapy. The objective of this prospective study was to investigate the value of two types of positron emission tomography (PET) in the preoperative evaluation of diabetic patients with Charcot foot deformities. Materials and Methods: Ring [18F]FDG (2-fluoro-2-deoxy-glucose) and hybrid PET were compared to magnetic resonance imaging (MRI). MRI, ring PET, and hybrid PET imaging were used as part of the preoperative evaluation of 16 patients with type II diabetes mellitus. The diagnosis of Charcot neuropathy of the foot requiring operative treatment had been made on the basis of clinical and radiographic criteria. Results: Of 39 Charcot lesions confirmed at surgery, 37 were detected by ring PET, 30 by hybrid PET, and 31 by MRI. Conclusions: PET (ring or hybrid) can be used in the evaluation of patients with metal implants that would compromise the accuracy of MRI. Another advantage of PET is its ability to distinguish between inflammatory and infectious soft-tissue lesions, and between osteomyelitis and Charcot neuroarthropathy. The differentiation between Charcot neuroarthropathy and florid osteomyelitis provides the surgeon with important additional information that often is unavailable from MRI. Because it provides important additional data, ring PET may be preferable to radiography and MRI in the preoperative evaluation of patients with Charcot neuroarthropathy of the foot. Hybrid PET, because of its poorer resolution compared to ring PET, appears less suitable for routine clinical application.