115 research outputs found

    Shape from stereo : a systematic approach using quadratic surfaces

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    We used quadratic shapes in several psychophysical shape-from-stereo tasks. The shapes were elegantly represented in a 2-D parameter space by the scale-independent shape index and the scale-dependent curvedness. Using random-dot stereograms to depict the surfaces, we found that the shape of hyperbolic surfaces is slightly more difficult to recognize than the shape of elliptic surfaces. We found that curvedness (and indirectly, scale) has little or no influence on shape recognition

    Everolimus- and sirolimus-eluting stents in patients with and without ST-segment elevation myocardial infarction

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    Aims Everolimus-eluting stents (EES) were superior to sirolimus-eluting stents (SES) in a dedicated myocardial infarction trial, a finding that was not observed in trials with low percentages of ST-elevation myocardial infarction (STEMI). Therefore, this study sought to investigate the influence of clinical presentation on outcome after EES and SES implantation. Methods A pooled population of 1602 randomised patients was formed from XAMI (acute MI trial) and APPENDIXAMI (all-comer trial). Primary outcome was cardiac mortality, MI and target vessel revascularisation at 2 years. Secondary endpoints included definite/probable stent thrombosis (ST). Adjustment was done using Cox regression. Results In total, 902 EES and 700 SES patientswere included, of which 44%STEMI patients (EES 455; SES 257) and 56% without STEMI (EES 447; SES 443). In the pooled population, EES and SES showed similar outcomes during followup. Moreover, no differences in the endpoints were observed after stratification according to presentation. Although a trend toward reduced early definite/probable ST was observed in EES compared with SES in STEMI patients, long-term ST rates were low and comparable. Conclusions EES and SES showed a similar outcome during 2-year follow-up, regardless of clinical presentation. Longterm safety was excellent for both devices, despite wide inclusion criteria and a large sub-population of STEMI patients

    Second-Generation Everolimus-Eluting Stents Versus First-Generation Sirolimus-Eluting Stents in Acute Myocardial Infarction 1-Year Results of the Randomized XAMI (XienceV Stent vs. Cypher Stent in Primary PCI for Acute Myocardial Infarction) Trial

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    ObjectivesThe goal of this study was to compare the efficacy and safety of second-generation everolimus-eluting stents (EES) with first-generation sirolimus-eluting stents (SES) in primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).BackgroundDrug-eluting stents (DES) in AMI are still feared for possible late and very late stent thrombosis (ST). Newer-generation DES, with more hemocompatible polymers and improved healing, may show promise regarding increased efficacy of DES with improved safety. However, no randomized trials in AMI are available.MethodsA total of 625 patients with AMI were randomized (2:1) to receive EES or SES in the XAMI (XienceV Stent vs Cypher Stent in Primary PCI for Acute Myocardial Infarction) trial. Primary endpoint was major adverse cardiac events (MACE) at 1 year consisting of cardiac death, nonfatal AMI, or any target vessel revascularization. The study was powered for noninferiority of EES. Secondary endpoints comprised ST rates and MACE rate up to 3 years.ResultsThe MACE rate was 4.0% for EES and 7.7% for SES; the absolute difference was −3.7% (95% confidence interval: −8.28 to −0.03; p = 0.048) and relative risk was 0.52 (95% confidence interval: 0.27 to 1.00). One-year cardiac mortality was low at 1.5% for EES versus 2.7% for SES (p = 0.36), and 1-year incidence of definite and/or probable ST was 1.2% for EES versus 2.7% for SES (p = 0.21).ConclusionsIn this all-comer, randomized, multicenter AMI trial, second-generation EES was noninferior to SES, and superiority for MACE was suggested. ST rate in EES at 1-year was low, but long-term follow-up and larger studies will have to show whether very late ST rates will also be improved in newer DES. (XienceV Stent vs Cypher Stent in Primary PCI for Acute Myocardial Infarction [XAMI]; NTR1123

    Molecular imaging to identify patients with metastatic breast cancer who benefit from endocrine treatment combined with cyclin-dependent kinase inhibition

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    BACKGROUND: Adding cyclin-dependent kinase (CDK) inhibitor to endocrine treatment improves outcome in œstrogen receptor (ER) positive metastatic breast cancer, but identifying the subset of patients who benefit is challenging. Response is potentially associated with ER expression heterogeneity. This is because, unlike the primary tumour in the breast that is localized to the organ, the metastatic breast cancer has spread and continues to spread to distant locations in the body such as bones, lungs, liver, axial skeleton, even to the central nervous system like the brain, wherefrom obtaining biopsies are not easy, and also, the metastasised tissues are heterogeneous. Positron emission tomography (PET) with 16α-[18F]fluoro-17β-œstradiol (FES), briefly referred to as FES-PET, allows whole-body ER assessment. We explored whether FES-PET heterogeneity and FES uptake were related to letrozole and palbociclib outcome, in patients with ER positive, metastatic breast cancer. PATIENTS AND METHODS: Patients underwent a baseline FES-PET and 18F-fluorodeoxyglucose (FDG) PET, the FDG-PET served to help identify active sites of breast cancer with contrast-enhanced computed tomography (CT). FES-PET heterogeneity score (% FES positive lesions divided by all lesions on FDG-PET and/or CT) and FES uptake were related to outcome and 8-week FDG-PET response. Circulating tumour DNA (CtDNA) samples for ESR1 mutation analysis were collected at baseline. RESULTS: In 30 patients with 864 metastatic lesions, baseline FES-PET heterogeneity was assessed. In 27 patients with 688 lesions, response was evaluated. Median time to progression (TTP) was 73 weeks (95% confidence interval [CI] 21 to ∞) in 7 patients with 100% FES positive disease, 27 weeks (14-49) in heterogeneous FES positive disease (20 patients), and 15 weeks (9 to ∞) without FES positivity (three patients; log-rank P = 0.30). Geometric mean FES uptake was 2.3 for metabolic progressive patients, 2.5 (Pvs progression = 0.82) for metabolic stable disease, and 3.3 (Pvs progression = 0.40) for metabolic response (Ptrend = 0.21). ESR1 mutations, found in 13/23 patients, were unrelated to FES uptake. CONCLUSION: This exploratory study suggests that FES-PET heterogeneity may potentially identify the subset of ER positive, metastatic breast cancer patients who benefit from letrozole combined with CDK inhibition. CLINICAL TRIAL INFORMATION: NCT02806050

    First-in-human study of the biodistribution and pharmacokinetics of <sup>89</sup>Zr-CX-072, a novel immunopet tracer based on an anti–PD-L1 probody

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    Purpose: CX-072, a PD-L1–targeting Probody therapeutic, is engineered to be activated by tumor proteases that remove a masking peptide. To study effects on biodistribution and pharmacokinetics, we performed 89Zr-CX-072 positron emission tomography (PET) imaging. Experimental Design: Patients received 1 mg, 37 MBq 89Zr-CX-072 plus 0, 4, or 9 mg unlabeled CX-072 and PET scans at days 2, 4, and 7. After that, treatment comprised 10 mg/kg CX-072 q2 weeks (n ¼ 7) þ 3 mg/kg ipilimumab q3w 4 (n ¼ 1). Normal organ tracer uptake was expressed as standardized uptake value (SUV)mean and tumor uptake as SUVmax. PD-L1 expression was measured immunohistochemically in archival tumor tissue. Results: Three of the eight patients included received 10-mg protein dose resulting in a blood pool mean SUVmean SD of 4.27 0.45 on day 4, indicating sufficient available tracer. Tumor uptake was highest at day 7, with a geometric mean SUVmax 5.89 (n ¼ 113) and present in all patients. The median follow-up was 12 weeks (4–76þ). One patient experienced stable disease and two patients a partial response. PD-L1 tumor expression was 90% in one patient and ≤1% in the other patients. Mean SUVmean SD day 4 at 10 mg in the spleen was 8.56 1.04, bone marrow 2.21 0.46, and liver 4.97 0.97. Four patients out of seven showed uptake in normal lymph nodes and Waldeyer’s ring. The tracer was intact in the serum or plasma. Conclusions: 89Zr-CX-072 showed tumor uptake, even in lesions with ≤1% PD-L1 expression, and modest uptake in normal lymphoid organs, with no unexpected uptake in other healthy tissues

    Assessment of Bone Lesions with F-18-FDG PET Compared with Tc-99m Bone Scintigraphy Leads to Clinically Relevant Differences in Metastatic Breast Cancer Management

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    It is unknown whether assessment of potential bone lesions in metastatic breast cancer (MBC) by F-18-FDG PET instead of Tc-99m bone scintigraphy (BS) supports clinically relevant changes in MBC management. Therefore, we retrospectively compared management recommendations based on bone lesion assessment by (18)FFDG PET plus contrast-enhanced CT (ceCT) or BS plus ceCT, for patients with newly diagnosed MBC. Methods: Baseline ceCT, BS, and F-18-FDG PET for all patients included in the IMPACT-MBC study (NCT01957332) at the University Medical Center Groningen were reviewed for bone lesions. If bone lesions were found by any imaging modality, virtual MBC management recommendations were made by a multidisciplinary expert panel, based on either F-18-FDG PET plus ceCT or BS plus ceCT. The panel had access to standard clinicopathologic information and baseline imaging findings outside the skeleton. Clinically relevant management differences between the 2 recommendations were defined either as different treatment intent (curative, noncurative, or unable to determine) or as different systemic or local treatment. If no bone lesions were found by any imaging modality, the patients were included in the analyses without expert review. Results: In total, 3,473 unequivocal bone lesions were identified in 10(2) evaluated patients (39% by ceCT, 26% by BS, and 87% by F-18-FDG PET). Additional bone lesions on F-18-FDG PET plus ceCT compared with BS plus ceCT led to change in MBC management recommendations in 16% of patients (95% CI, 10%-24%). BS also changed management compared with F-18-FDG PET in 1 patient (1%; 95% CI, 0%-5%). In 26% (95% CI, 19%-36%) of patients, an additional F-18-FDG PET exam was requested, because BS provided insufficient information. Conclusion: In this exploratory analysis of newly diagnosed MBC patients, F-18-FDG PET versus BS to assess bone lesions resulted in clinically relevant management differences in 16% of patients. BS delivered insufficient information in over one fourth of patients, resulting in an additional request for F-18-FDG PET. On the basis of these data, F-18-FDG PET should be considered a primary imaging modality for assessment of bone lesions in newly diagnosed MBC

    Genomic patterns resembling BRCA1- and BRCA2-mutated breast cancers predict benefit of intensified carboplatin-based chemotherapy

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    Introduction: BRCA-mutated breast cancer cells lack the DNA-repair mechanism homologous recombination that is required for error-free DNA double-strand break (DSB) repair. Homologous recombination deficiency (HRD) may cause hypersensitivity to DNA DSB-inducing agents, such as bifunctional alkylating agents and platinum salts. HRD can be caused by BRCA mutations, and by other mechanisms. To identify HRD, studies have focused on triple-negative (TN) breast cancers as these resemble BRCA1-mutated breast cancer closely and might also share this hypersensitivity. However, ways to identify HRD in non-BRCA-mutated, estrogen receptor (ER)-positive breast cancers have remained elusive. The current study provides evidence that genomic patterns resembling BRCA1- or BRCA2- mutated breast cancers can identify breast cancer patients with TN as well as ER-positive, HER2-negative tumors that are sensitive to intensified, DSB-inducing chemotherapy. Methods: Array comparative genomic hybridization (aCGH) was used to classify breast cancers. Patients with tumors with similar aCGH patterns as BRCA1- and/or BRCA2-mutated breast cancers were defined as having a BRCA-like(CGH) status, others as non-BCRA-like(CGH). Stage-III patients (n = 249) had participated in a randomized controlled trial of adjuvant high-dose (HD) cyclophosphamide-thiotepa-carboplatin (CTC) versus 5-fluorouracil-epirubicin-cyclophosphamide (FE90C) chemotherapy. Results: Among patients with BRCA-like(CGH) tumors (81/249, 32%), a significant benefit of HD-CTC compared to FE90C was observed regarding overall survival (adjusted hazard ratio 0.19, 95% CI: 0.08 to 0.48) that was not seen for patients with non-BRCA-like(CGH) tumors (adjusted hazard ratio 0.90, 95% CI: 0.53 to 1.54) (P = 0.004). Half of all BRCA-like(CGH) tumors were ER-positive. Conclusions: Distinct aCGH patterns differentiated between HER2-negative patients with a markedly improved outcome after adjuvant treatment with an intensified DNA-DSB-inducing regimen (BRCA-like(CGH) patients) and those without benefit (non-BRCA-like(CGH) patients)

    Haptoglobin phenotype is not a predictor of recurrence free survival in high-risk primary breast cancer patients

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    Contains fulltext : 70104tjan-heijnen.pdf (publisher's version ) (Open Access)BACKGROUND: Better breast cancer prognostication may improve selection of patients for adjuvant therapy. We conducted a retrospective follow-up study in which we investigated sera of high-risk primary breast cancer patients, to search for proteins predictive of recurrence free survival. METHODS: Two sample sets of high-risk primary breast cancer patients participating in a randomised national trial investigating the effectiveness of high-dose chemotherapy were analysed. Sera in set I (n = 63) were analysed by surface enhanced laser desorption ionisation time-of-flight mass spectrometry (SELDI-TOF MS) for biomarker finding. Initial results were validated by analysis of sample set II (n = 371), using one-dimensional gel-electrophoresis. RESULTS: In sample set I, the expression of a peak at mass-to-charge ratio 9198 (relative intensity 20), identified as haptoglobin (Hp) alpha-1 chain, was strongly associated with recurrence free survival (global Log-rank test; p = 0.0014). Haptoglobin is present in three distinct phenotypes (Hp 1-1, Hp 2-1, and Hp 2-2), of which only individuals with phenotype Hp 1-1 or Hp 2-1 express the haptoglobin alpha-1 chain. As the expression of the haptoglobin alpha-1 chain, determined by SELDI-TOF MS, corresponds to the phenotype, initial results were validated by haptoglobin phenotyping of the independent sample set II by native one-dimensional gel-electrophoresis. With the Hp 1-1 phenotype as the reference category, the univariate hazard ratio for recurrence was 0.87 (95% CI: 0.56 - 1.34, p = 0.5221) and 1.03 (95% CI: 0.65 - 1.64, p = 0.8966) for the Hp 2-1 and Hp 2-2 phenotypes, respectively, in sample set II. CONCLUSION: In contrast to our initial results, the haptoglobin phenotype was not identified as a predictor of recurrence free survival in high-risk primary breast cancer in our validation set. Our initial observation in the discovery set was probably the result of a type I error (i.e. false positive). This study illustrates the importance of validation in obtaining the true clinical applicability of a potential biomarker

    Lesion detection by [89Zr]Zr-DFO-girentuximab and [18F]FDG-PET/CT in patients with newly diagnosed metastatic renal cell carcinoma

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    Purpose: The main objective of this preliminary analysis of the IMaging PAtients for Cancer drug selecTion (IMPACT)-renal cell cancer (RCC) study is to evaluate the lesion detection of baseline contrast-enhanced CT, [89Zr]Zr-DFO-girentuximab-PET/CT and [18F]FDG-PET/CT in detecting ccRCC lesions in patients with a good or intermediate prognosis metastatic clear cell renal cell carcinoma (mccRCC) according to the International Metastatic Database Consortium (IMDC) risk model. Methods: Between February 2015 and March 2018, 42 newly diagnosed mccRCC patients with good or intermediate prognosis, eligible for watchful waiting, were included. Patients underwent CT, [89Zr]Zr-DFO-girentuximab-PET/CT and [18F]FDG-PET/CT at baseline. Scans were independently reviewed and lesions of ≥10 mm and lymph nodes of ≥15 mm at CT were analyzed. For lesions with [89Zr]Zr-DFO-girentuximab or [18F]FDG-uptake visually exceeding background uptake, maximum standardized uptake values (SUVmax) were measured. Results: A total of 449 lesions were detected by ≥1 modality (median per patient: 7; ICR 4.25–12.75) of which 42% were in lung, 22% in lymph nodes and 10% in bone. Combined [89Zr]Zr-DFO-girentuximab-PET/CT and CT detected more lesions than CT alone: 91% (95%CI: 87–94) versus 56% (95%CI: 50–62, p = 0.001), respectively, and more than CT and [18F]FDG-PET/CT combined (84% (95%CI:79–88, p < 0.005). Both PET/CTs detected more bone and soft tissue lesions compared to CT alone. Conclusions: The addition of [89Zr]Zr-DFO-girentuximab-PET/CT and [18F]FDG-PET/CT to CT increases lesion detection compared to CT alone in newly diagnosed good and intermediate prognosis mccRCC patients eligible for watchful waiting
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