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Sample records for fluoromisonidazole pet predicts

  1. Ischemic penumbra in acute stroke: Demonstration by PET with fluorine-18 fluoromisonidazole

    SciTech Connect

    Yeh, S.H.; Liu, R.S.; Hu, H.H.

    1994-05-01

    Ischemic penumbra (IP) in acute stroke has gained clinical interest since tissue functions may be recovered if perfusion can be reestablished. However, such therapeutic intervention is {open_quotes}blind{close_quotes} since clinical examination can not distinguish IP from developing infarction. In vivo demonstration of IP may have significance for stroke patient management. This study was a preliminary evaluation of detecting IP in vivo by F-18 fluoromisonidazole ([F-18]-FMISO), a hypoxic imaging agent. Static PET imaging was performed after IV injection of 370 MBq of [F-18]-FMISO at 20 and 120 min. Tomograms were reconstructed and evaluated visually in correlation with CT or MR scans. In acute stroke, patients (pts) were called back for the second PET study one month after the initial study. CT was used for confirming infarction. In 6 pts with acute cerebral infarction, three of them had intense [F-18]-FMISO retention in the penumbra surrounding the central, eclipse-like zone of absent radio-activity (infarction) at 2 hr in the acute state, and the penumbra disappeared in association with increased area of infarction on CT in one case in the chronic state. In five pts with chronic infarction, all had no penumbra of [F-18]-FMISO retention. In summary, our preliminary results demonstrate the feasibility of using [F-18]-FMISO PET to detect ischemic penumbra in vivo.

  2. Assessing Biological Response to Bevacizumab Using 18F-Fluoromisonidazole PET/MR Imaging in a Patient with Recurrent Anaplastic Astrocytoma

    PubMed Central

    Barajas, Ramon F.; Pampaloni, Miguel H.; Clarke, Jennifer L.; Seo, Youngho; Savic, Dragana; Hawkins, Randall A.; Behr, Spencer C.; Chang, Susan M.; Berger, Mitchel; Dillon, William P.; Cha, Soonmee

    2015-01-01

    We present our initial experience in using single modality fluoromisonidazole (FMISO) PET/MR imaging to noninvasively evaluate the biological effects induced by bevacizumab therapy in a patient treated for recurrent high grade glioma. In this index patient, bevacizumab therapy resulted in the development of nonenhancing tumor characterized by reduced diffusion and markedly decreased FMISO uptake in the setting of maintained CBF and CBV. These observations suggest that the dynamic biological interplay between tissue hypoxia and vascular normalization occurring within treated recurrent high grade glioma can be captured utilizing FMISO PET/MR imaging. PMID:25793136

  3. Noninvasive assessment of tumor microenvironment using dynamic contrast enhanced MRI and 18F- fluoromisonidazole PET imaging in neck nodal metastases

    PubMed Central

    Jansen, Jacobus F. A.; Schöder, Heiko; Lee, Nancy Y.; Wang, Ya; Pfister, David. G.; Fury, Matthew G.; Stambuk, Hilda. E.; Humm, John L.; Koutcher, Jason A.; Shukla-Dave, Amita

    2009-01-01

    Purpose Pretreatment multimodality imaging can provide useful anatomical and functional data about tumors, including perfusion and possibly hypoxia status. The purpose of our study was to assess non-invasively the tumor microenvironment of neck nodal metastases in patients with head and neck (HN) cancer by investigating the relationship between tumor perfusion measured using Dynamic Contrast Enhanced MRI (DCE-MRI) and hypoxia measured by 18F-fluoromisonidazole (18F-FMISO) PET. Methods and Materials Thirteen newly diagnosed HN cancer patients with metastatic neck nodes underwent DCE-MRI and 18F-FMISO PET imaging prior to chemotherapy and radiation therapy. The matched regions of interests from both modalities were analyzed. To examine the correlations between DCE-MRI parameters and standard uptake value (SUV) measurements from 18F-FMISO PET, the non-parametric Spearman correlation coefficient was calculated. Furthermore, DCE-MRI parameters were compared between nodes with 18F-FMISO uptake and nodes with no 18F-FMISO uptake using Mann-Whitney U tests. Results For the 13 patients, a total of 18 nodes were analyzed. The nodal size strongly correlated with the 18F-FMISO SUV (ρ=0.74, p<0.001). There was a strong negative correlation between the median kep (ρ=−0.58, p=0.042) and the 18F-FMISO SUV. Hypoxic nodes (moderate to severe 18F-FMISO uptake) had significantly lower median Ktrans (p=0.049) and median kep (p=0.027) values than did non-hypoxic nodes (no 18F-FMISO uptake). Conclusion This initial evaluation of the preliminary results support the hypothesis that in metastatic neck lymph nodes, hypoxic nodes are poorly perfused (i.e., have significantly lower kep and Ktrans values) compared to non-hypoxic nodes. PMID:19906496

  4. [{sup 18}F]fluoromisonidazole and a New PET System With Semiconductor Detectors and a Depth of Interaction System for Intensity Modulated Radiation Therapy for Nasopharyngeal Cancer

    SciTech Connect

    Yasuda, Koichi; Onimaru, Rikiya; Okamoto, Shozo; Shiga, Tohru; Katoh, Norio; Tsuchiya, Kazuhiko; Suzuki, Ryusuke; Takeuchi, Wataru; Kuge, Yuji; Tamaki, Nagara; Shirato, Hiroki

    2013-01-01

    Purpose: The impact of a new type of positron emission tomography (New PET) with semiconductor detectors using {sup 18}F-labeled fluoromisonidazole (FMISO)-guided intensity modulated radiation therapy (IMRT) was compared with a state-of-the-art PET/computed tomography (PET/CT) system in nasopharyngeal cancer (NPC) patients. Methods and Materials: Twenty-four patients with non-NPC malignant tumors (control group) and 16 patients with NPC were subjected to FMISO-PET. The threshold of the tumor-to-muscle (T/M) ratio in each PET scan was calculated. The hypoxic volume within the gross tumor volume (GTVh) was determined using each PET ({sub NewPET}GTVh and {sub PET/CT}GTVh, respectively). Dose escalation IMRT plans prescribing 84 Gy to each GTVh were carried out. Results: The threshold of the T/M ratio was 1.35 for New PET and 1.23 for PET/CT. The mean volume of {sub NewPET}GTVh was significantly smaller than that of {sub PET/CT}GTVh (1.5 {+-} 1.6 cc vs 4.7 {+-} 4.6 cc, respectively; P=.0020). The dose escalation IMRT plans using New PET were superior in dose distribution to those using PET/CT. Dose escalation was possible in all 10 New PET-guided plans but not in 1 PET/CT-guided plan, because the threshold dose to the brainstem was exceeded. Conclusions: New PET was found to be useful for accurate dose escalation in FMISO-guided IMRT for patients with NPC.

  5. A Comparative Study of Noninvasive Hypoxia Imaging with 18F-Fluoroerythronitroimidazole and 18F-Fluoromisonidazole PET/CT in Patients with Lung Cancer

    PubMed Central

    Huang, Yong; Yu, Qingxi; Zhu, Shouhui; Wang, Suzhen; Zhao, Shuqiang; Hu, Xudong; Yu, Jinming; Yuan, Shuanghu

    2016-01-01

    Purpose This is a clinical study to compare noninvasive hypoxia imaging using 18F-fluoroerythronitroimidazole (18F-FETNIM) and 18F-fluoromisonidazole (18F-FMISO) positron emission tomography/computed tomography (PET/CT) in patients with inoperable stages III–IV lung cancer. Methods A total of forty-two patients with inoperable stages III–IV lung cancer underwent 18F-FETNIM PET/CT (n = 18) and 18F-FMISO PET/CT (n = 24) before chemo/radiation therapy. The standard uptake values (SUVs) of malignant and normal tissues depict 18F-FETNIM PET/CT and 18F-FMISO PET/CT uptake. Tumor-to-blood ratios (T/B) were used to quantify hypoxia. Results All patients with lung cancer underwent 18F-FETNIM PET/CT and 18F-FMISO PET/CT successfully. Compared to 18F-FMISO, 18F-FETNIM showed similar uptake in muscle, thyroid, spleen, pancreas, heart, lung and different uptake in blood, liver, and kidney. Significantly higher SUV and T/B ratio with 18F-FMISO (2.56±0.77, 1.98±0.54), as compared to 18F-FETNIM (2.12±0.56, 1.42±0.33) were seen in tumor, P = 0.022, <0.001. For the patients with different histopathological subtypes, no significant difference of SUV (or T/B ratio) was observed both in 18F-FMISO and 18F-FETNIM in tumor. A significantly different SUV (or T/B ratio) was detected between < = 2cm, 2~5cm, and >5cm groups in 18F-FMISO PET/CT, P = 0.015 (or P = 0.029), whereas no difference was detected in 18F-FMISO PET/CT, P = 0.446 (or P = 0.707). Both 18F-FETNIM and 18F-FMISO showed significantly higher SUVs (or T/B ratios) in stage IV than stage III, P = 0.021, 0.013 (or P = 0.032, 0.02). Conclusion 18F-FMISO showed significantly higher uptake than 18F-FETNIM in tumor/non-tumor ratio and might be a better hypoxia tracer in lung cancer. PMID:27322586

  6. [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography in response evaluation after chemo-/radiotherapy of non-small-cell lung cancer: a feasibility study

    PubMed Central

    Gagel, Bernd; Reinartz, Patrick; Demirel, Cengiz; Kaiser, Hans J; Zimny, Michael; Piroth, Marc; Pinkawa, Michael; Stanzel, Sven; Asadpour, Branka; Hamacher, Kurt; Coenen, Heinz H; Buell, Ulrich; Eble, Michael J

    2006-01-01

    Background Experimental and clinical evidence suggest that hypoxia in solid tumours reduces their sensitivity to conventional treatment modalities modulating response to ionizing radiation or chemotherapeutic agents. The aim of the present study was to show the feasibility of determining radiotherapeutically relevant hypoxia and early tumour response by ([18F] Fluoromisonidazole (FMISO) and [18F]-2-fluoro-2'-deoxyglucose (FDG) PET. Methods Eight patients with non-small-cell lung cancer underwent PET scans. Tumour tissue oxygenation was measured with FMISO PET, whereas tumour glucose metabolism was measured with FDG PET. All PET studies were carried out with an ECAT EXACT 922/47® scanner with an axial field of view of 16.2 cm. FMISO PET consisted of one static scan of the relevant region, performed 180 min after intravenous administration of the tracer. The acquisition and reconstruction parameters were as follows: 30 min emission scanning and 4 min transmission scanning with 68-Ge/68-Ga rod sources. The patients were treated with chemotherapy, consisting of 2 cycles of gemcitabine (1200 mg/m2) and vinorelbine (30 mg/m2) followed by concurrent radio- (2.0 Gy/d; total dose 66.0 Gy) and chemotherapy with gemcitabine (300–500 mg/m2) every two weeks. FMISO PET and FDG PET were performed in all patients 3 days before and 14 days after finishing chemotherapy. Results FMISO PET allowed for the qualitative and quantitative definition of hypoxic sub-areas which may correspond to a localization of local recurrences. In addition, changes in FMISO and FDG PET measure the early response to therapy, and in this way, may predict freedom from disease, as well as overall survival. Conclusion These preliminary results warrant validation in larger trials. If confirmed, several novel treatment strategies may be considered, including the early use of PET to evaluate the effectiveness of the selected therapy. PMID:16515707

  7. Predictive and prognostic value of FDG-PET

    PubMed Central

    Oyen, Wim J.G.

    2008-01-01

    Abstract The predictive and prognostic value of fluorodeoxyglucose (FDG)-positron emission tomography (PET) in non-small-cell lung carcinoma, colorectal carcinoma and lymphoma is discussed. The degree of FDG uptake is of prognostic value at initial presentation, after induction treatment prior to resection and in the case of relapse of non-small cell lung cancer (NSCLC). In locally advanced and advanced stages of NSCLC, FDG-PET has been shown to be predictive for clinical outcome at an early stage of treatment. In colorectal carcinoma, limited studies are available on the prognostic value of FDG-PET, however, the technique appears to have great potential in monitoring the success of local ablative therapies soon after intervention and in the prediction and evaluation of response to radiotherapy, systemic therapy, and combinations thereof. The prognostic value of end-of treatment FDG-PET for FDG-avid lymphomas has been established, and the next step is to define how to use this information to optimize patient outcome. In Hodgkin's lymphoma, FDG-PET has a high negative predictive value, however, histological confirmation of positive findings should be sought where possible. For non-Hodgkin's lymphoma, the opposite applies. The newly published standardized guidelines for interpretation formulates specific criteria for visual interpretation and for defining PET positivity in the liver, spleen, lung, bone marrow and small residual lesions. The introduction of these guidelines should reduce variability among studies. Interim PET offers a reliable method for early prediction of long-term remission, however it should only be performed in prospective randomized controlled trials. Many of the diagnostic and management questions considered in this review are relevant to other tumour types. Further research in this field is of great importance, since it may lead to a change in the therapeutic concept of cancer. The preliminary findings call for systematic inclusion of FDG-PET

  8. Nanoreporter PET predicts the efficacy of anti-cancer nanotherapy.

    PubMed

    Pérez-Medina, Carlos; Abdel-Atti, Dalya; Tang, Jun; Zhao, Yiming; Fayad, Zahi A; Lewis, Jason S; Mulder, Willem J M; Reiner, Thomas

    2016-01-01

    The application of nanoparticle drug formulations, such as nanoliposomal doxorubicin (Doxil), is increasingly integrated in clinical cancer care. Despite nanomedicine's remarkable potential and growth over the last three decades, its clinical benefits for cancer patients vary. Here we report a non-invasive quantitative positron emission tomography (PET) nanoreporter technology that is predictive of therapeutic outcome in individual subjects. In a breast cancer mouse model, we demonstrate that co-injecting Doxil and a Zirconium-89 nanoreporter ((89)Zr-NRep) allows precise doxorubicin (DOX) quantification. Importantly, (89)Zr-NRep uptake also correlates with other types of nanoparticles' tumour accumulation. (89)Zr-NRep PET imaging reveals remarkable accumulation heterogeneity independent of tumour size. We subsequently demonstrate that mice with >25 mg kg(-1) DOX accumulation in tumours had significantly better growth inhibition and enhanced survival. This non-invasive imaging tool may be developed into a robust inclusion criterion for patients amenable to nanotherapy. PMID:27319780

  9. Nanoreporter PET predicts the efficacy of anti-cancer nanotherapy

    PubMed Central

    Pérez-Medina, Carlos; Abdel-Atti, Dalya; Tang, Jun; Zhao, Yiming; Fayad, Zahi A.; Lewis, Jason S.; Mulder, Willem J. M.; Reiner, Thomas

    2016-01-01

    The application of nanoparticle drug formulations, such as nanoliposomal doxorubicin (Doxil), is increasingly integrated in clinical cancer care. Despite nanomedicine's remarkable potential and growth over the last three decades, its clinical benefits for cancer patients vary. Here we report a non-invasive quantitative positron emission tomography (PET) nanoreporter technology that is predictive of therapeutic outcome in individual subjects. In a breast cancer mouse model, we demonstrate that co-injecting Doxil and a Zirconium-89 nanoreporter (89Zr-NRep) allows precise doxorubicin (DOX) quantification. Importantly, 89Zr-NRep uptake also correlates with other types of nanoparticles' tumour accumulation. 89Zr-NRep PET imaging reveals remarkable accumulation heterogeneity independent of tumour size. We subsequently demonstrate that mice with >25 mg kg−1 DOX accumulation in tumours had significantly better growth inhibition and enhanced survival. This non-invasive imaging tool may be developed into a robust inclusion criterion for patients amenable to nanotherapy. PMID:27319780

  10. Multiparametric [18F]Fluorodeoxyglucose/ [18F]Fluoromisonidazole Positron Emission Tomography/ Magnetic Resonance Imaging of Locally Advanced Cervical Cancer for the Non-Invasive Detection of Tumor Heterogeneity: A Pilot Study

    PubMed Central

    Andrzejewski, Piotr; Baltzer, Pascal; Polanec, Stephan H.; Sturdza, Alina; Georg, Dietmar; Helbich, Thomas H.; Karanikas, Georgios; Grimm, Christoph; Polterauer, Stephan; Poetter, Richard; Wadsak, Wolfgang; Mitterhauser, Markus; Georg, Petra

    2016-01-01

    Objectives To investigate fused multiparametric positron emission tomography/magnetic resonance imaging (MP PET/MRI) at 3T in patients with locally advanced cervical cancer, using high-resolution T2-weighted, contrast-enhanced MRI (CE-MRI), diffusion-weighted imaging (DWI), and the radiotracers [18F]fluorodeoxyglucose ([18F]FDG) and [18F]fluoromisonidazol ([18F]FMISO) for the non-invasive detection of tumor heterogeneity for an improved planning of chemo-radiation therapy (CRT). Materials and Methods Sixteen patients with locally advanced cervix were enrolled in this IRB approved and were examined with fused MP [18F]FDG/ [18F]FMISO PET/MRI and in eleven patients complete data sets were acquired. MP PET/MRI was assessed for tumor volume, enhancement (EH)-kinetics, diffusivity, and [18F]FDG/ [18F]FMISO-avidity. Descriptive statistics and voxel-by-voxel analysis of MRI and PET parameters were performed. Correlations were assessed using multiple correlation analysis. Results All tumors displayed imaging parameters concordant with cervix cancer, i.e. type II/III EH-kinetics, restricted diffusivity (median ADC 0.80x10-3mm2/sec), [18F]FDG- (median SUVmax16.2) and [18F]FMISO-avidity (median SUVmax3.1). In all patients, [18F]FMISO PET identified the hypoxic tumor subvolume, which was independent of tumor volume. A voxel-by-voxel analysis revealed only weak correlations between the MRI and PET parameters (0.05–0.22), indicating that each individual parameter yields independent information and the presence of tumor heterogeneity. Conclusion MP [18F]FDG/ [18F]FMISO PET/MRI in patients with cervical cancer facilitates the acquisition of independent predictive and prognostic imaging parameters. MP [18F]FDG/ [18F]FMISO PET/MRI enables insights into tumor biology on multiple levels and provides information on tumor heterogeneity, which has the potential to improve the planning of CRT. PMID:27167829

  11. Positron Emission Tomography (PET) Evaluation After Initial Chemotherapy and Radiation Therapy Predicts Local Control in Rhabdomyosarcoma

    SciTech Connect

    Dharmarajan, Kavita V.; Wexler, Leonard H.; Gavane, Somali; Fox, Josef J.; Schoder, Heiko; Tom, Ashlyn K.; Price, Alison N.; Meyers, Paul A.; Wolden, Suzanne L.

    2012-11-15

    Purpose: 18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control. Patients and Methods: We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test. Results: The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax {<=}7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax {<=}7 vs 79% for SUVmax >7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06). Conclusion: Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

  12. F-18 fluoromisonidazole for imaging tumor hypoxia: imaging the microenvironment for personalized cancer therapy.

    PubMed

    Rajendran, Joseph G; Krohn, Kenneth A

    2015-03-01

    Hypoxia in solid tumors is one of the seminal mechanisms for developing aggressive trait and treatment resistance in solid tumors. This evolutionarily conserved biological mechanism along with derepression of cellular functions in cancer, although resulting in many challenges, provide us with opportunities to use these adversities to our advantage. Our ability to use molecular imaging to characterize therapeutic targets such as hypoxia and apply this information for therapeutic interventions is growing rapidly. Evaluation of hypoxia and its biological ramifications to effectively plan appropriate therapy that can overcome the cure-limiting effects of hypoxia provides an objective means for treatment selection and planning. Fluoromisonidazole (FMISO) continues to be the lead radiopharmaceutical in PET imaging for the evaluation, prognostication, and quantification of tumor hypoxia, one of the key elements of the tumor microenvironment. FMISO is less confounded by blood flow, and although the images have less contrast than FDG-PET, its uptake after 2 hours is an accurate reflection of inadequate regional oxygen partial pressure at the time of radiopharmaceutical administration. By virtue of extensive clinical utilization, FMISO remains the lead candidate for imaging and quantifying hypoxia. The past decade has seen significant technological advances in investigating hypoxia imaging in radiation treatment planning and in providing us with the ability to individualize radiation delivery and target volume coverage. The presence of widespread hypoxia in the tumor can be effectively targeted with a systemic hypoxic cell cytotoxin or other agents that are more effective with diminished oxygen partial pressure, either alone or in combination. Molecular imaging in general and hypoxia imaging in particular will likely become an important in vivo imaging biomarker of the future, complementing the traditional direct tissue sampling methods by providing a snap shot of a primary

  13. Respiratory trace feature analysis for the prediction of respiratory-gated PET quantification

    NASA Astrophysics Data System (ADS)

    Wang, Shouyi; Bowen, Stephen R.; Chaovalitwongse, W. Art; Sandison, George A.; Grabowski, Thomas J.; Kinahan, Paul E.

    2014-02-01

    The benefits of respiratory gating in quantitative PET/CT vary tremendously between individual patients. Respiratory pattern is among many patient-specific characteristics that are thought to play an important role in gating-induced imaging improvements. However, the quantitative relationship between patient-specific characteristics of respiratory pattern and improvements in quantitative accuracy from respiratory-gated PET/CT has not been well established. If such a relationship could be estimated, then patient-specific respiratory patterns could be used to prospectively select appropriate motion compensation during image acquisition on a per-patient basis. This study was undertaken to develop a novel statistical model that predicts quantitative changes in PET/CT imaging due to respiratory gating. Free-breathing static FDG-PET images without gating and respiratory-gated FDG-PET images were collected from 22 lung and liver cancer patients on a PET/CT scanner. PET imaging quality was quantified with peak standardized uptake value (SUVpeak) over lesions of interest. Relative differences in SUVpeak between static and gated PET images were calculated to indicate quantitative imaging changes due to gating. A comprehensive multidimensional extraction of the morphological and statistical characteristics of respiratory patterns was conducted, resulting in 16 features that characterize representative patterns of a single respiratory trace. The six most informative features were subsequently extracted using a stepwise feature selection approach. The multiple-regression model was trained and tested based on a leave-one-subject-out cross-validation. The predicted quantitative improvements in PET imaging achieved an accuracy higher than 90% using a criterion with a dynamic error-tolerance range for SUVpeak values. The results of this study suggest that our prediction framework could be applied to determine which patients would likely benefit from respiratory motion compensation

  14. Respiratory trace feature analysis for the prediction of respiratory-gated PET quantification.

    PubMed

    Wang, Shouyi; Bowen, Stephen R; Chaovalitwongse, W Art; Sandison, George A; Grabowski, Thomas J; Kinahan, Paul E

    2014-02-21

    The benefits of respiratory gating in quantitative PET/CT vary tremendously between individual patients. Respiratory pattern is among many patient-specific characteristics that are thought to play an important role in gating-induced imaging improvements. However, the quantitative relationship between patient-specific characteristics of respiratory pattern and improvements in quantitative accuracy from respiratory-gated PET/CT has not been well established. If such a relationship could be estimated, then patient-specific respiratory patterns could be used to prospectively select appropriate motion compensation during image acquisition on a per-patient basis. This study was undertaken to develop a novel statistical model that predicts quantitative changes in PET/CT imaging due to respiratory gating. Free-breathing static FDG-PET images without gating and respiratory-gated FDG-PET images were collected from 22 lung and liver cancer patients on a PET/CT scanner. PET imaging quality was quantified with peak standardized uptake value (SUV(peak)) over lesions of interest. Relative differences in SUV(peak) between static and gated PET images were calculated to indicate quantitative imaging changes due to gating. A comprehensive multidimensional extraction of the morphological and statistical characteristics of respiratory patterns was conducted, resulting in 16 features that characterize representative patterns of a single respiratory trace. The six most informative features were subsequently extracted using a stepwise feature selection approach. The multiple-regression model was trained and tested based on a leave-one-subject-out cross-validation. The predicted quantitative improvements in PET imaging achieved an accuracy higher than 90% using a criterion with a dynamic error-tolerance range for SUV(peak) values. The results of this study suggest that our prediction framework could be applied to determine which patients would likely benefit from respiratory motion

  15. Predicting standard-dose PET image from low-dose PET and multimodal MR images using mapping-based sparse representation.

    PubMed

    Wang, Yan; Zhang, Pei; An, Le; Ma, Guangkai; Kang, Jiayin; Shi, Feng; Wu, Xi; Zhou, Jiliu; Lalush, David S; Lin, Weili; Shen, Dinggang

    2016-01-21

    Positron emission tomography (PET) has been widely used in clinical diagnosis for diseases and disorders. To obtain high-quality PET images requires a standard-dose radionuclide (tracer) injection into the human body, which inevitably increases risk of radiation exposure. One possible solution to this problem is to predict the standard-dose PET image from its low-dose counterpart and its corresponding multimodal magnetic resonance (MR) images. Inspired by the success of patch-based sparse representation (SR) in super-resolution image reconstruction, we propose a mapping-based SR (m-SR) framework for standard-dose PET image prediction. Compared with the conventional patch-based SR, our method uses a mapping strategy to ensure that the sparse coefficients, estimated from the multimodal MR images and low-dose PET image, can be applied directly to the prediction of standard-dose PET image. As the mapping between multimodal MR images (or low-dose PET image) and standard-dose PET images can be particularly complex, one step of mapping is often insufficient. To this end, an incremental refinement framework is therefore proposed. Specifically, the predicted standard-dose PET image is further mapped to the target standard-dose PET image, and then the SR is performed again to predict a new standard-dose PET image. This procedure can be repeated for prediction refinement of the iterations. Also, a patch selection based dictionary construction method is further used to speed up the prediction process. The proposed method is validated on a human brain dataset. The experimental results show that our method can outperform benchmark methods in both qualitative and quantitative measures. PMID:26732849

  16. Predicting standard-dose PET image from low-dose PET and multimodal MR images using mapping-based sparse representation

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Zhang, Pei; An, Le; Ma, Guangkai; Kang, Jiayin; Shi, Feng; Wu, Xi; Zhou, Jiliu; Lalush, David S.; Lin, Weili; Shen, Dinggang

    2016-01-01

    Positron emission tomography (PET) has been widely used in clinical diagnosis for diseases and disorders. To obtain high-quality PET images requires a standard-dose radionuclide (tracer) injection into the human body, which inevitably increases risk of radiation exposure. One possible solution to this problem is to predict the standard-dose PET image from its low-dose counterpart and its corresponding multimodal magnetic resonance (MR) images. Inspired by the success of patch-based sparse representation (SR) in super-resolution image reconstruction, we propose a mapping-based SR (m-SR) framework for standard-dose PET image prediction. Compared with the conventional patch-based SR, our method uses a mapping strategy to ensure that the sparse coefficients, estimated from the multimodal MR images and low-dose PET image, can be applied directly to the prediction of standard-dose PET image. As the mapping between multimodal MR images (or low-dose PET image) and standard-dose PET images can be particularly complex, one step of mapping is often insufficient. To this end, an incremental refinement framework is therefore proposed. Specifically, the predicted standard-dose PET image is further mapped to the target standard-dose PET image, and then the SR is performed again to predict a new standard-dose PET image. This procedure can be repeated for prediction refinement of the iterations. Also, a patch selection based dictionary construction method is further used to speed up the prediction process. The proposed method is validated on a human brain dataset. The experimental results show that our method can outperform benchmark methods in both qualitative and quantitative measures.

  17. Predicting the laterality of temporal lobe epilepsy from PET, MRI, and DTI: A multimodal study

    PubMed Central

    Pustina, Dorian; Avants, Brian; Sperling, Michael; Gorniak, Richard; He, Xiaosong; Doucet, Gaelle; Barnett, Paul; Mintzer, Scott; Sharan, Ashwini; Tracy, Joseph

    2015-01-01

    Pre-surgical evaluation of patients with temporal lobe epilepsy (TLE) relies on information obtained from multiple neuroimaging modalities. The relationship between modalities and their combined power in predicting the seizure focus is currently unknown. We investigated asymmetries from three different modalities, PET (glucose metabolism), MRI (cortical thickness), and diffusion tensor imaging (DTI; white matter anisotropy) in 28 left and 30 right TLE patients (LTLE and RTLE). Stepwise logistic regression models were built from each modality separately and from all three combined, while bootstrapped methods and split-sample validation verified the robustness of predictions. Among all multimodal asymmetries, three PET asymmetries formed the best predictive model (100% success in full sample, >95% success in split-sample validation). The combinations of PET with other modalities did not perform better than PET alone. Probabilistic classifications were obtained for new clinical cases, which showed correct lateralization for 7/7 new TLE patients (100%) and for 4/5 operated patients with discordant or non-informative PET reports (80%). Metabolism showed closer relationship with white matter in LTLE and closer relationship with gray matter in RTLE. Our data suggest that metabolism is a powerful modality that can predict seizure laterality with high accuracy, and offers high value for automated predictive models. The side of epileptogenic focus can affect the relationship of metabolism with brain structure. The data and tools necessary to obtain classifications for new TLE patients are made publicly available. PMID:26288753

  18. PET imaging predicts future body weight and cocaine preference

    SciTech Connect

    Michaelides M.; Wang G.; Michaelides M.; Thanos P.K. Kim R.; Cho J.; Ananth M.; Wang G.-J.; Volkow N.D.

    2011-08-28

    Deficits in dopamine D2/D3 receptor (D2R/D3R) binding availability using PET imaging have been reported in obese humans and rodents. Similar deficits have been reported in cocaine-addicts and cocaine-exposed primates. We found that D2R/D3R binding availability negatively correlated with measures of body weight at the time of scan (ventral striatum), at 1 (ventral striatum) and 2 months (dorsal and ventral striatum) post scan in rats. Cocaine preference was negatively correlated with D2R/D3R binding availability 2 months (ventral striatum) post scan. Our findings suggest that inherent deficits in striatal D2R/D3R signaling are related to obesity and drug addiction susceptibility and that ventral and dorsal striatum serve dissociable roles in maintaining weight gain and cocaine preference. Measuring D2R/D3R binding availability provides a way for assessing susceptibility to weight gain and cocaine abuse in rodents and given the translational nature of PET imaging, potentially primates and humans.

  19. Predicting Response to Neoadjuvant Chemotherapy with PET Imaging Using Convolutional Neural Networks.

    PubMed

    Ypsilantis, Petros-Pavlos; Siddique, Musib; Sohn, Hyon-Mok; Davies, Andrew; Cook, Gary; Goh, Vicky; Montana, Giovanni

    2015-01-01

    Imaging of cancer with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) has become a standard component of diagnosis and staging in oncology, and is becoming more important as a quantitative monitor of individual response to therapy. In this article we investigate the challenging problem of predicting a patient's response to neoadjuvant chemotherapy from a single 18F-FDG PET scan taken prior to treatment. We take a "radiomics" approach whereby a large amount of quantitative features is automatically extracted from pretherapy PET images in order to build a comprehensive quantification of the tumor phenotype. While the dominant methodology relies on hand-crafted texture features, we explore the potential of automatically learning low- to high-level features directly from PET scans. We report on a study that compares the performance of two competing radiomics strategies: an approach based on state-of-the-art statistical classifiers using over 100 quantitative imaging descriptors, including texture features as well as standardized uptake values, and a convolutional neural network, 3S-CNN, trained directly from PET scans by taking sets of adjacent intra-tumor slices. Our experimental results, based on a sample of 107 patients with esophageal cancer, provide initial evidence that convolutional neural networks have the potential to extract PET imaging representations that are highly predictive of response to therapy. On this dataset, 3S-CNN achieves an average 80.7% sensitivity and 81.6% specificity in predicting non-responders, and outperforms other competing predictive models. PMID:26355298

  20. Predicting Response to Neoadjuvant Chemotherapy with PET Imaging Using Convolutional Neural Networks

    PubMed Central

    Ypsilantis, Petros-Pavlos; Siddique, Musib; Sohn, Hyon-Mok; Davies, Andrew; Cook, Gary; Goh, Vicky; Montana, Giovanni

    2015-01-01

    Imaging of cancer with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) has become a standard component of diagnosis and staging in oncology, and is becoming more important as a quantitative monitor of individual response to therapy. In this article we investigate the challenging problem of predicting a patient’s response to neoadjuvant chemotherapy from a single 18F-FDG PET scan taken prior to treatment. We take a “radiomics” approach whereby a large amount of quantitative features is automatically extracted from pretherapy PET images in order to build a comprehensive quantification of the tumor phenotype. While the dominant methodology relies on hand-crafted texture features, we explore the potential of automatically learning low- to high-level features directly from PET scans. We report on a study that compares the performance of two competing radiomics strategies: an approach based on state-of-the-art statistical classifiers using over 100 quantitative imaging descriptors, including texture features as well as standardized uptake values, and a convolutional neural network, 3S-CNN, trained directly from PET scans by taking sets of adjacent intra-tumor slices. Our experimental results, based on a sample of 107 patients with esophageal cancer, provide initial evidence that convolutional neural networks have the potential to extract PET imaging representations that are highly predictive of response to therapy. On this dataset, 3S-CNN achieves an average 80.7% sensitivity and 81.6% specificity in predicting non-responders, and outperforms other competing predictive models. PMID:26355298

  1. Potential Clinical Value of Multiparametric PET in the Prediction of Alzheimer’s Disease Progression

    PubMed Central

    Chen, Xueqi; Zhou, Yun; Wang, Rongfu; Cao, Haoyin; Reid, Savina; Gao, Rui; Han, Dong

    2016-01-01

    Objective To evaluate the potential clinical value of quantitative functional FDG PET and pathological amyloid-β PET with cerebrospinal fluid (CSF) biomarkers and clinical assessments in the prediction of Alzheimer’s disease (AD) progression. Methods We studied 82 subjects for up to 96 months (median = 84 months) in a longitudinal Alzheimer’s Disease Neuroimaging Initiative (ADNI) project. All preprocessed PET images were spatially normalized to standard Montreal Neurologic Institute space. Regions of interest (ROI) were defined on MRI template, and standard uptake values ratios (SUVRs) to the cerebellum for FDG and amyloid-β PET were calculated. Predictive values of single and multiparametric PET biomarkers with and without clinical assessments and CSF biomarkers for AD progression were evaluated using receiver operating characteristic (ROC) analysis and logistic regression model. Results The posterior precuneus and cingulate SUVRs were identified for both FDG and amyloid-β PET in predicating progression in normal controls (NCs) and subjects with mild cognitive impairment (MCI). FDG parietal and lateral temporal SUVRs were suggested for monitoring NCs and MCI group progression, respectively. 18F-AV45 global cortex attained (78.6%, 74.5%, 75.4%) (sensitivity, specificity, accuracy) in predicting NC progression, which is comparable to the 11C-PiB global cortex SUVR’s in predicting MCI to AD. A logistic regression model to combine FDG parietal and posterior precuneus SUVR and Alzheimer’s Disease Assessment Scale-Cognitive (ADAS-Cog) Total Mod was identified in predicating NC progression with (80.0%, 94.9%, 93.9%) (sensitivity, specificity, accuracy). The selected model including FDG posterior cingulate SUVR, ADAS-Cog Total Mod, and Mini-Mental State Exam (MMSE) scores for predicating MCI to AD attained (96.4%, 81.2%, 83.6%) (sensitivity, specificity, accuracy). 11C-PiB medial temporal SUVR with MMSE significantly increased 11C-PiB PET AUC to 0.915 (p<0

  2. FDG-PET Response Prediction in Pediatric Hodgkin’s Lymphoma: Impact of Metabolically Defined Tumor Volumes and Individualized SUV Measurements on the Positive Predictive Value

    PubMed Central

    Hussien, Amr Elsayed M.; Furth, Christian; Schönberger, Stefan; Hundsdoerfer, Patrick; Steffen, Ingo G.; Amthauer, Holger; Müller, Hans-Wilhelm; Hautzel, Hubertus

    2015-01-01

    Background: In pediatric Hodgkin’s lymphoma (pHL) early response-to-therapy prediction is metabolically assessed by (18)F-FDG PET carrying an excellent negative predictive value (NPV) but an impaired positive predictive value (PPV). Aim of this study was to improve the PPV while keeping the optimal NPV. A comparison of different PET data analyses was performed applying individualized standardized uptake values (SUV), PET-derived metabolic tumor volume (MTV) and the product of both parameters, termed total lesion glycolysis (TLG); Methods: One-hundred-eight PET datasets (PET1, n = 54; PET2, n = 54) of 54 children were analysed by visual and semi-quantitative means. SUVmax, SUVmean, MTV and TLG were obtained the results of both PETs and the relative change from PET1 to PET2 (Δ in %) were compared for their capability of identifying responders and non-responders using receiver operating characteristics (ROC)-curves. In consideration of individual variations in noise and contrasts levels all parameters were additionally obtained after threshold correction to lean body mass and background; Results: All semi-quantitative SUV estimates obtained at PET2 were significantly superior to the visual PET2 analysis. However, ΔSUVmax revealed the best results (area under the curve, 0.92; p < 0.001; sensitivity 100%; specificity 85.4%; PPV 46.2%; NPV 100%; accuracy, 87.0%) but was not significantly superior to SUVmax-estimation at PET2 and ΔTLGmax. Likewise, the lean body mass and background individualization of the datasets did not impove the results of the ROC analyses; Conclusions: Sophisticated semi-quantitative PET measures in early response assessment of pHL patients do not perform significantly better than the previously proposed ΔSUVmax. All analytical strategies failed to improve the impaired PPV to a clinically acceptable level while preserving the excellent NPV. PMID:25635760

  3. Positron Emission Tomography/Computed Tomography Imaging of Residual Skull Base Chordoma Before Radiotherapy Using Fluoromisonidazole and Fluorodeoxyglucose: Potential Consequences for Dose Painting

    SciTech Connect

    Mammar, Hamid; Kerrou, Khaldoun; Nataf, Valerie; Pontvert, Dominique; Clemenceau, Stephane; Lot, Guillaume; George, Bernard; Polivka, Marc; Mokhtari, Karima; Ferrand, Regis; Feuvret, Loiec; Habrand, Jean-louis; Pouyssegur, Jacques; Mazure, Nathalie; Talbot, Jean-Noeel

    2012-11-01

    Purpose: To detect the presence of hypoxic tissue, which is known to increase the radioresistant phenotype, by its uptake of fluoromisonidazole (18F) (FMISO) using hybrid positron emission tomography/computed tomography (PET/CT) imaging, and to compare it with the glucose-avid tumor tissue imaged with fluorodeoxyglucose (18F) (FDG), in residual postsurgical skull base chordoma scheduled for radiotherapy. Patients and Methods: Seven patients with incompletely resected skull base chordomas were planned for high-dose radiotherapy (dose {>=}70 Gy). All 7 patients underwent FDG and FMISO PET/CT. Images were analyzed qualitatively by visual examination and semiquantitatively by computing the ratio of the maximal standardized uptake value (SUVmax) of the tumor and cerebellum (T/C R), with delineation of lesions on conventional imaging. Results: Of the eight lesion sites imaged with FDG PET/CT, only one was visible, whereas seven of nine lesions were visible on FMISO PET/CT. The median SUVmax in the tumor area was 2.8 g/mL (minimum 2.1; maximum 3.5) for FDG and 0.83 g/mL (minimum 0.3; maximum 1.2) for FMISO. The T/C R values ranged between 0.30 and 0.63 for FDG (median, 0.41) and between 0.75 and 2.20 for FMISO (median,1.59). FMISO T/C R >1 in six lesions suggested the presence of hypoxic tissue. There was no correlation between FMISO and FDG uptake in individual chordomas (r = 0.18, p = 0.7). Conclusion: FMISO PET/CT enables imaging of the hypoxic component in residual chordomas. In the future, it could help to better define boosted volumes for irradiation and to overcome the radioresistance of these lesions. No relationship was founded between hypoxia and glucose metabolism in these tumors after initial surgery.

  4. FDG-PET/CT predicts outcome in patients with aggressive non-Hodgkin's lymphoma and Hodgkin's disease.

    PubMed

    Querellou, Solène; Valette, Frédéric; Bodet-Milin, Caroline; Oudoux, Aurore; Carlier, Thomas; Harousseau, Jean-Luc; Chatal, Jean-François; Couturier, Olivier

    2006-11-01

    Early therapy response assessment with metabolic imaging is potentially useful to determine prognosis in aggressive lymphoma and, thus, can guide first-line therapy. Forty-eight patients with aggressive lymphoma [24 Hodgkin's disease (HD); 24 non-Hodgkin's lymphoma (NHL)] underwent fluoro-deoxyglucose positron emission tomography (FDG-PET) before chemotherapy (PET1) and at mid-treatment (PET2). Therapeutic response was evaluated using conventional methods at mid-treatment. PET2 results were related to event-free survival (EFS) and overall survival (OS) using Kaplan-Meier analyses. PET1 was positive in all patients. PET2 was negative in 38 patients (18 NHL-20 HD) and positive in 10 (6 NHL-4 HD). Of the PET-negative patients, 61 and 65% achieved complete remission, and only 50 and 25% of PET-positive patients, respectively, for NHL and HD, achieved complete remission. Significant associations were found between PET2 and EFS (p = 0.0006) and OS (p = 0.04) for NHL, and EFS (p < 0.0001) for HD (but not for OS, because no HD patient died). FDG-PET at mid-treatment can predict the outcome of patients with aggressive lymphoma and should be a useful tool to modify an ineffective therapy. PMID:16871391

  5. A patient-specific computational model of hypoxia-modulated radiation resistance in glioblastoma using 18F-FMISO-PET

    PubMed Central

    Rockne, Russell C.; Trister, Andrew D.; Jacobs, Joshua; Hawkins-Daarud, Andrea J.; Neal, Maxwell L.; Hendrickson, Kristi; Mrugala, Maciej M.; Rockhill, Jason K.; Kinahan, Paul; Krohn, Kenneth A.; Swanson, Kristin R.

    2015-01-01

    Glioblastoma multiforme (GBM) is a highly invasive primary brain tumour that has poor prognosis despite aggressive treatment. A hallmark of these tumours is diffuse invasion into the surrounding brain, necessitating a multi-modal treatment approach, including surgery, radiation and chemotherapy. We have previously demonstrated the ability of our model to predict radiographic response immediately following radiation therapy in individual GBM patients using a simplified geometry of the brain and theoretical radiation dose. Using only two pre-treatment magnetic resonance imaging scans, we calculate net rates of proliferation and invasion as well as radiation sensitivity for a patient's disease. Here, we present the application of our clinically targeted modelling approach to a single glioblastoma patient as a demonstration of our method. We apply our model in the full three-dimensional architecture of the brain to quantify the effects of regional resistance to radiation owing to hypoxia in vivo determined by [18F]-fluoromisonidazole positron emission tomography (FMISO-PET) and the patient-specific three-dimensional radiation treatment plan. Incorporation of hypoxia into our model with FMISO-PET increases the model–data agreement by an order of magnitude. This improvement was robust to our definition of hypoxia or the degree of radiation resistance quantified with the FMISO-PET image and our computational model, respectively. This work demonstrates a useful application of patient-specific modelling in personalized medicine and how mathematical modelling has the potential to unify multi-modality imaging and radiation treatment planning. PMID:25540239

  6. 18F-FDG PET/CT Prediction of an Aggressive Clinical Course for Dermatofibrosarcoma Protuberans.

    PubMed

    Basu, Sandip; Goliwale, Fahim

    2016-06-01

    The ability to assess tumor biology is a benefit of molecular imaging with (18)F-FDG PET/CT, which performs better than anatomic imaging in evaluating malignancies. We present an unusual case of fatal dermatofibrosarcoma protuberans, a usually indolent entity for which high-grade (18)F-FDG uptake was predictive of an aggressive clinical course unabated by tyrosine kinase inhibitor imatinib mesylate, to which the patient showed a poor response. PMID:26338485

  7. FDG-PET as a predictive biomarker for therapy with everolimus in metastatic renal cell cancer

    PubMed Central

    Chen, James L; Appelbaum, Daniel E; Kocherginsky, Masha; Cowey, Charles L; Kimryn Rathmell, Wendy; McDermott, David F; Stadler, Walter M

    2013-01-01

    Abstract The mTOR (mammalian target of rapamycin) inhibitor, everolimus, affects tumor growth by targeting cellular metabolic proliferation pathways and delays renal cell carcinoma (RCC) progression. Preclinical evidence suggests that baseline elevated tumor glucose metabolism as quantified by FDG-PET ([18F] fluorodeoxy-glucose positron emission tomography) may predict antitumor activity. Metastatic RCC (mRCC) patients refractory to vascular endothelial growth factor (VEGF) pathway inhibition were treated with standard dose everolimus. FDG-PET scans were obtained at baseline and 2 weeks; serial computed tomography (CT) scans were obtained at baseline and every 8 weeks. Maximum standardized uptake value (SUVmax) of the most FDG avid lesion, average SUVmax of all measured lesions and their corresponding 2-week relative changes were examined for association with 8-week change in tumor size. A total of 63 patients were enrolled; 50 were evaluable for the primary endpoint of which 48 had both PET scans. Patient characteristics included the following: 36 (72%) clear cell histology and median age 59 (range: 37–80). Median pre- and 2-week treatment average SUVmax were 6.6 (1–17.9) and 4.2 (1–13.9), respectively. Response evaluation criteria in solid tumors (RECIST)-based measurements demonstrated an average change in tumor burden of 0.2% (−32.7% to 35.9%) at 8 weeks. Relative change in average SUVmax was the best predictor of change in tumor burden (all evaluable P = 0.01; clear cell subtype P = 0.02), with modest correlation. Baseline average SUVmax was correlated with overall survival and progression-free survival (PFS) (P = 0.023; 0.020), but not with change in tumor burden. Everolimus therapy decreased SUVs on follow-up PET scans in mRCC patients, but changes were only modestly correlated with changes in tumor size. Thus, clinical use of FDG-PET-based biomarkers is challenged by high variability. In this phase II trial, FDG-PET was explored as a

  8. The use of FDG-PET in diffuse large B cell lymphoma (DLBCL): predicting outcome following first line therapy.

    PubMed

    Coughlan, Monica; Elstrom, Rebecca

    2014-01-01

    Positron emission tomography (PET) using 18fluoro-2-deoxyglucose (FDG) has become a standard clinical tool for staging and response assessment in aggressive lymphomas. The use of PET scans in clinical trials is still under exploration, however. In this review, we examine current data regarding PET in DLBCL, and its potential applicability to development of a surrogate endpoint to expedite clinical trial conduct. Interim PET scanning in DLBCL shows mixed results, with qualitative assessment variably associated with outcome. Addition of quantitative assessment might improve predictive power of interim scans. Data from multiple retrospective studies support that PET-defined response at end of treatment correlates with outcome in DLBCL. Optimal technical criteria for standardization of acquisition and criteria for interpretation of scans require further study. Prospective studies to define the correlation of PET-defined response and time-dependent outcomes such as progression free survival (PFS) and overall survival (OS), critical for development of PET as a surrogate endpoint for clinical trials, are ongoing. In conclusion, evolving data regarding utility of PET in predictcing outcome of patients with DLBCL show promise to support the use of PET as a surrogate endpoint in clinical trials of DLBCL in the future. PMID:25608713

  9. Fluorine-18-Labeled Fluoromisonidazole Positron Emission and Computed Tomography-Guided Intensity-Modulated Radiotherapy for Head and Neck Cancer: A Feasibility Study

    PubMed Central

    Lee, Nancy Y.; Mechalakos, James G.; Nehmeh, Sadek; Lin, Zhixiong; Squire, Olivia D.; Cai, Shangde; Chan, Kelvin; Zanzonico, Pasquale B.; Greco, Carlo; Ling, Clifton C.; Humm, John L.; Schöder, Heiko

    2010-01-01

    Purpose Hypoxia renders tumor cells radioresistant, limiting locoregional control from radiotherapy (RT). Intensity-modulated RT (IMRT) allows for targeting of the gross tumor volume (GTV) and can potentially deliver a greater dose to hypoxic subvolumes (GTVh) while sparing normal tissues. A Monte Carlo model has shown that boosting the GTVh increases the tumor control probability. This study examined the feasibility of fluorine-18–labeled fluoromisonidazole positron emission tomography/computed tomography (18F-FMISO PET/CT)–guided IMRT with the goal of maximally escalating the dose to radioresistant hypoxic zones in a cohort of head and neck cancer (HNC) patients. Methods and Materials 18F-FMISO was administered intravenously for PET imaging. The CT simulation, fluorodeoxyglucose PET/CT, and 18F-FMISO PET/CT scans were co-registered using the same immobilization methods. The tumor boundaries were defined by clinical examination and available imaging studies, including fluorodeoxyglucose PET/CT. Regions of elevated 18F-FMISO uptake within the fluorodeoxyglucose PET/CT GTV were targeted for an IMRT boost. Additional targets and/or normal structures were contoured or transferred to treatment planning to generate 18F-FMISO PET/CT-guided IMRT plans. Results The heterogeneous distribution of 18F-FMISO within the GTV demonstrated variable levels of hypoxia within the tumor. Plans directed at performing 18F-FMISO PET/CT–guided IMRT for 10 HNC patients achieved 84 Gy to the GTVh and 70 Gy to the GTV, without exceeding the normal tissue tolerance. We also attempted to deliver 105 Gy to the GTVh for 2 patients and were successful in 1, with normal tissue sparing. Conclusion It was feasible to dose escalate the GTVh to 84 Gy in all 10 patients and in 1 patient to 105 Gy without exceeding the normal tissue tolerance. This information has provided important data for subsequent hypoxia-guided IMRT trials with the goal of further improving locoregional control in HNC

  10. Tumor Response and Survival Predicted by Post-Therapy FDG-PET/CT in Anal Cancer

    SciTech Connect

    Schwarz, Julie K.; Siegel, Barry A.; Dehdashti, Farrokh; Myerson, Robert J.; Fleshman, James W.; Grigsby, Perry W.

    2008-05-01

    Purpose: To evaluate the response to therapy for anal carcinoma using post-therapy imaging with positron emission tomography (PET)/computed tomography and F-18 fluorodeoxyglucose (FDG) and to compare the metabolic response with patient outcome. Patients and Methods: This was a prospective cohort study of 53 consecutive patients with anal cancer. All patients underwent pre- and post-treatment whole-body FDG-PET/computed tomography. Patients had been treated with external beam radiotherapy and concurrent chemotherapy. Whole-body FDG-PET was performed 0.9-5.4 months (mean, 2.1) after therapy completion. Results: The post-therapy PET scan did not show any abnormal FDG uptake (complete metabolic response) in 44 patients. Persistent abnormal FDG uptake (partial metabolic response) was found in the anal tumor in 9 patients. The 2-year cause-specific survival rate was 94% for patients with a complete vs. 39% for patients with a partial metabolic response in the anal tumor (p = 0.0008). The 2-year progression-free survival rate was 95% for patients with a complete vs. 22% for patients with a partial metabolic response in the anal tumor (p < 0.0001). A Cox proportional hazards model of survival outcome indicated that a complete metabolic response was the most significant predictor of progression-free survival in our patient population (p = 0.0003). Conclusions: A partial metabolic response in the anal tumor as determined by post-therapy FDG-PET is predictive of significantly decreased progression-free and cause-specific survival after chemoradiotherapy for anal cancer.

  11. A Model of Reoxygenation Dynamics of Head-And-Neck Tumors Based on Serial 18F-Fluoromisonidazole Positron Emission Tomography Investigations

    SciTech Connect

    Thorwarth, Daniela . E-mail: daniela.thorwarth@med.uni-tuebingen.de; Eschmann, Susanne-Martina; Paulsen, Frank; Alber, Markus

    2007-06-01

    Purpose: To develop a model for reoxygenation dynamic and its relationship to local control after radiotherapy (RT), based on repeated dynamic [{sup 18}F]-fluoromisonidazole (FMISO) positron emission tomography (PET) examinations in head-and-neck cancer patients. Methods and Materials: Ten head-and-neck cancer patients were examined with dynamic FMISO PET before RT with 70 Gy and after approximately 20 Gy. Two of these patients had two additional dynamic FMISO scans during treatment. Local recurrence was assessed by computed tomography-based follow-up 8-24 months after RT. Tumor-specific values for the level of FMISO retention R and the vascular perfusion efficiency P were determined with a kinetic compartment model. Results: Individual R-P scattergrams before and during therapy were analyzed, and significant therapy-induced changes in the characteristic R-P patterns were observed. A tumor control probability model was derived that involves the tissue parameters R and P and estimates the time to reoxygenation. On the basis of this model, a malignancy value M was introduced and calibrated by a fit to the observed outcome data. Reoxygenation is reflected by the model as a progression to less-malignant tumor types (i.e., smaller values of M). In 4 of 6 patients with severe hypoxia, M had decreased after 20 Gy, whereas 2 patients showed increasing M. Four patients showed no hypoxia in the pretreatment scan. Conclusion: A tumor control probability model was developed based on repeated FMISO PET scans during RT. The model combines the local perfusion efficiency and the degree of hypoxia to estimate reoxygenation time. It constitutes a key for hypoxia image-guided dose escalation in RT.

  12. Noninvasive Assessment of Tumor Microenvironment Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging and {sup 18}F-Fluoromisonidazole Positron Emission Tomography Imaging in Neck Nodal Metastases

    SciTech Connect

    Jansen, Jacobus; Schoeder, Heiko; Lee, Nancy Y.; Wang Ya

    2010-08-01

    Purpose: To assess noninvasively the tumor microenvironment of neck nodal metastases in patients with head-and-neck cancer by investigating the relationship between tumor perfusion measured using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hypoxia measured by {sup 18}F-fluoromisonidazole ({sup 18}F-FMISO) positron emission tomography (PET). Methods and Materials: Thirteen newly diagnosed head-and-neck cancer patients with metastatic neck nodes underwent DCE-MRI and {sup 18}F-FMISO PET imaging before chemotherapy and radiotherapy. The matched regions of interests from both modalities were analyzed. To examine the correlations between DCE-MRI parameters and standard uptake value (SUV) measurements from {sup 18}F-FMISO PET, the nonparametric Spearman correlation coefficient was calculated. Furthermore, DCE-MRI parameters were compared between nodes with {sup 18}F-FMISO uptake and nodes with no {sup 18}F-FMISO uptake using Mann-Whitney U tests. Results: For the 13 patients, a total of 18 nodes were analyzed. The nodal size strongly correlated with the {sup 18}F-FMISO SUV ({rho} = 0.74, p < 0.001). There was a strong negative correlation between the median k{sub ep} (redistribution rate constant) value ({rho} = -0.58, p = 0.042) and the {sup 18}F-FMISO SUV. Hypoxic nodes (moderate to severe {sup 18}F-FMISO uptake) had significantly lower median K{sup trans} (volume transfer constant) (p = 0.049) and median k{sub ep} (p = 0.027) values than did nonhypoxic nodes (no {sup 18}F-FMISO uptake). Conclusion: This initial evaluation of the preliminary results support the hypothesis that in metastatic neck lymph nodes, hypoxic nodes are poorly perfused (i.e., have significantly lower K{sup trans} and k{sub ep} values) compared with nonhypoxic nodes.

  13. [18F]-Fluoromisonidazole Positron Emission Tomography/Computed Tomography Visualization of Tumor Hypoxia in Patients With Chordoma of the Mobile and Sacrococcygeal Spine

    SciTech Connect

    Cheney, Matthew D.; Chen, Yen-Lin; Lim, Ruth; Winrich, Barbara K.; Grosu, Anca L.; Trofimov, Alexei V.; Depauw, Nicolas; Shih, Helen A.; Schwab, Joseph H.; Hornicek, Francis J.; DeLaney, Thomas F.

    2014-12-01

    Purpose: To investigate [18F]-fluoromisonidazole positron emission tomography/computed tomography (FMISO-PET/CT) detection of targetable hypoxic subvolumes (HSVs) in chordoma of the mobile or sacrococcygeal spine. Methods and Materials: A prospective, pilot study of 20 patients with primary or locally recurrent chordoma of the mobile or sacrococcygeal spine treated with proton or combined proton/photon radiation therapy (RT) with or without surgery was completed. The FMISO-PET/CT was performed before RT and after 19.8-34.2 GyRBE (relative biologic effectiveness). Gross tumor volumes were delineated and HSVs defined including voxels with standardized uptake values ≥1.4 times the muscle mean. Clinical characteristics and treatments received were compared between patients with and without HSVs. Results: The FMISO-PET/CT detected HSVs in 12 of 20 patients (60%). Baseline and interval HSV spatial concordance varied (0%-94%). Eight HSVs were sufficiently large (≥5 cm{sup 3}) to potentially allow an intensity modulated proton therapy boost. Patients with HSVs had significantly larger gross tumor volumes (median 410.0 cm{sup 3} vs 63.4 cm{sup 3}; P=.02) and were significantly more likely to have stage T2 tumors (5 of 12 vs 0 of 8; P=.04). After a median follow-up of 1.8 years (range, 0.2-4.4 years), a local recurrence has yet to be observed. Three patients developed metastatic disease, 2 with HSVs. Conclusions: Detection of targetable HSVs by FMISO-PET/CT within patients undergoing RT with or without surgery for treatment of chordoma of the mobile and sacrococcygeal spine is feasible. The study's inability to attribute interval HSV changes to treatment, rapidly changing hypoxic physiology, or imaging inconsistencies is a limitation. Further study of double-baseline FMISO-PET/CT and hypoxia-directed RT dose escalation, particularly in patients at high risk for local recurrence, is warranted.

  14. Predicting location of recurrence using FDG, FLT, and Cu-ATSM PET in canine sinonasal tumors treated with radiotherapy

    NASA Astrophysics Data System (ADS)

    Bradshaw, Tyler; Fu, Rau; Bowen, Stephen; Zhu, Jun; Forrest, Lisa; Jeraj, Robert

    2015-07-01

    Dose painting relies on the ability of functional imaging to identify resistant tumor subvolumes to be targeted for additional boosting. This work assessed the ability of FDG, FLT, and Cu-ATSM PET imaging to predict the locations of residual FDG PET in canine tumors following radiotherapy. Nineteen canines with spontaneous sinonasal tumors underwent PET/CT imaging with radiotracers FDG, FLT, and Cu-ATSM prior to hypofractionated radiotherapy. Therapy consisted of 10 fractions of 4.2 Gy to the sinonasal cavity with or without an integrated boost of 0.8 Gy to the GTV. Patients had an additional FLT PET/CT scan after fraction 2, a Cu-ATSM PET/CT scan after fraction 3, and follow-up FDG PET/CT scans after radiotherapy. Following image registration, simple and multiple linear and logistic voxel regressions were performed to assess how well pre- and mid-treatment PET imaging predicted post-treatment FDG uptake. R2 and pseudo R2 were used to assess the goodness of fits. For simple linear regression models, regression coefficients for all pre- and mid-treatment PET images were significantly positive across the population (P < 0.05). However, there was large variability among patients in goodness of fits: R2 ranged from 0.00 to 0.85, with a median of 0.12. Results for logistic regression models were similar. Multiple linear regression models resulted in better fits (median R2 = 0.31), but there was still large variability between patients in R2. The R2 from regression models for different predictor variables were highly correlated across patients (R ≈ 0.8), indicating tumors that were poorly predicted with one tracer were also poorly predicted by other tracers. In conclusion, the high inter-patient variability in goodness of fits indicates that PET was able to predict locations of residual tumor in some patients, but not others. This suggests not all patients would be good candidates for dose painting based on a single biological target.

  15. Predicting location of recurrence using FDG, FLT, and Cu-ATSM PET in canine sinonasal tumors treated with radiotherapy.

    PubMed

    Bradshaw, Tyler; Fu, Rau; Bowen, Stephen; Zhu, Jun; Forrest, Lisa; Jeraj, Robert

    2015-07-01

    Dose painting relies on the ability of functional imaging to identify resistant tumor subvolumes to be targeted for additional boosting. This work assessed the ability of FDG, FLT, and Cu-ATSM PET imaging to predict the locations of residual FDG PET in canine tumors following radiotherapy. Nineteen canines with spontaneous sinonasal tumors underwent PET/CT imaging with radiotracers FDG, FLT, and Cu-ATSM prior to hypofractionated radiotherapy. Therapy consisted of 10 fractions of 4.2 Gy to the sinonasal cavity with or without an integrated boost of 0.8 Gy to the GTV. Patients had an additional FLT PET/CT scan after fraction 2, a Cu-ATSM PET/CT scan after fraction 3, and follow-up FDG PET/CT scans after radiotherapy. Following image registration, simple and multiple linear and logistic voxel regressions were performed to assess how well pre- and mid-treatment PET imaging predicted post-treatment FDG uptake. R(2) and pseudo R(2) were used to assess the goodness of fits. For simple linear regression models, regression coefficients for all pre- and mid-treatment PET images were significantly positive across the population (P < 0.05). However, there was large variability among patients in goodness of fits: R(2) ranged from 0.00 to 0.85, with a median of 0.12. Results for logistic regression models were similar. Multiple linear regression models resulted in better fits (median R(2) = 0.31), but there was still large variability between patients in R(2). The R(2) from regression models for different predictor variables were highly correlated across patients (R ≈ 0.8), indicating tumors that were poorly predicted with one tracer were also poorly predicted by other tracers. In conclusion, the high inter-patient variability in goodness of fits indicates that PET was able to predict locations of residual tumor in some patients, but not others. This suggests not all patients would be good candidates for dose painting based on a single biological target. PMID

  16. Selecting radiomic features from FDG-PET images for cancer treatment outcome prediction.

    PubMed

    Lian, Chunfeng; Ruan, Su; Denœux, Thierry; Jardin, Fabrice; Vera, Pierre

    2016-08-01

    As a vital task in cancer therapy, accurately predicting the treatment outcome is valuable for tailoring and adapting a treatment planning. To this end, multi-sources of information (radiomics, clinical characteristics, genomic expressions, etc) gathered before and during treatment are potentially profitable. In this paper, we propose such a prediction system primarily using radiomic features (e.g., texture features) extracted from FDG-PET images. The proposed system includes a feature selection method based on Dempster-Shafer theory, a powerful tool to deal with uncertain and imprecise information. It aims to improve the prediction accuracy, and reduce the imprecision and overlaps between different classes (treatment outcomes) in a selected feature subspace. Considering that training samples are often small-sized and imbalanced in our applications, a data balancing procedure and specified prior knowledge are taken into account to improve the reliability of the selected feature subsets. Finally, the Evidential K-NN (EK-NN) classifier is used with selected features to output prediction results. Our prediction system has been evaluated by synthetic and clinical datasets, consistently showing good performance. PMID:27236221

  17. Positive and Negative Predictive Value of PET-CT in Skull Base Lesions: Case Series and Systematic Literature Review

    PubMed Central

    Hines, John Peyton; Howard, Brittany E.; Hoxworth, Joseph M.; Lal, Devyani

    2016-01-01

    Objectives To study positive (PPV) and negative predictive value (NPV) of positron emission tomography with computed tomography (PET-CT) scans in determining malignancy in skull base lesions and perform a systematic literature review for optimal PET-CT interpretation. Design Retrospective case series and systematic literature review of the current English literature. Setting Tertiary referral academic medical center. Participants All patients with skull base lesions that underwent PET-CT and tissue biopsy from 2010 to 2013. Main Outcome Measures PPV and NPV of radiologist's report and standardized uptake value (SUV) cutoff of 2.5 and 3, biopsy with pathologic interpretation, clinical follow-up. Results A total of 31 PET-CT scans of 16 patients were studied; 10 PET-CT were performed upfront for diagnostic purposes and 21 were post-treatment surveillance scans. The PPV of radiologist's interpretation, SUV cutoff of 2.5, and SUV cutoff of 3.0 was 80%, 60%, and 68.4%, with a NPV of 100%, 83.3%, and 75%, respectively. Literature search yielded 500 abstracts; 7 studies met inclusion criteria for detailed review. No consensus or guidelines for optimal SUV cutoff value was found. Conclusions PET-CT based on SUV cutoff criteria alone has high NPV but low PPV in determining malignancy in skull base lesions. Interpretation by a radiologist experienced in nuclear medicine and neuroradiology, synthesizing clinical, SUV, and radiologic data are of superior value. PMID:26937333

  18. Early prediction of pathological response in locally advanced rectal cancer based on sequential 18F-FDG PET

    PubMed Central

    HATT, MATHIEU; VAN STIPHOUT, RUUD; LE POGAM, ADRIEN; LAMMERING, GUIDO; VISVIKIS, DIMITRIS; LAMBIN, PHILIPPE

    2016-01-01

    Background The objectives of this study were to investigate the predictive value of sequential 18F-FDG PET scans for pathological tumor response grade (TRG) after preoperative chemoradiotherapy (PCRT) in locally advanced rectal cancer (LARC) and the impact of partial volume effects correction (PVC). Methods Twenty-eight LARC patients were included. Responders and non-responders status were determined in histopathology. PET indices [SUV max and mean, volume and total lesion glycolysis (TLG)] at baseline and their evolution after one and two weeks of PCRT were extracted by delineation of the PET images, with or without PVC. Their predictive value was investigated using Mann-Whitney-U tests and ROC analysis. Results Within baseline parameters, only SUVmean was correlated with response. No evolution after one week was predictive of the response, whereas after two weeks all the parameters except volume were, the best prediction being obtained with TLG (AUC 0.79, sensitivity 63%, specificity 92%). PVC had no significant impact on these results. Conclusion Several PET indices at baseline and their evolution after two weeks of PCRT are good predictors of response in LARC, with or without PVC, whereas results after one week are suboptimal. Best predictor was TLG reduction after two weeks, although baseline SUVmean had smaller but similar predictive power. PMID:22873767

  19. Early outcome prediction on 18F-fluorocholine PET/CT in metastatic castration-resistant prostate cancer patients treated with abiraterone

    PubMed Central

    De Giorgi, Ugo; Caroli, Paola; Burgio, Salvatore L.; Menna, Cecilia; Conteduca, Vincenza; Bianchi, Emanuela; Fabbri, Francesca; Carretta, Elisa; Amadori, Dino; Paganelli, Giovanni; Matteucci, Federica

    2014-01-01

    Objective: We investigated the role of 18F-fluorocholine positron emission tomography/computed tomography (FCH-PET/CT) in the early evaluation of abiraterone and outcome prediction in patients with metastatic castration-resistant prostate cancer (CRPC). Patient and methods: Forty-three patients with metastatic CRPC progressing after docetaxel received abiraterone 1,000 mg daily with prednisone 5 mg twice daily. Patients were evaluated monthly for serological PSA response and safety. FCH-PET/CT was done at baseline and after 3 to 6 weeks. Univariate and multivariate Cox regression models addressed potential predictors of progression-free survival (PFS) and overall survival (OS). Results: Declines in PSA level of ≥50% were seen in 21 of 43 (49%) patients. Forty-two patients were evaluable for FCH-PET/CT response. FCH-PET/CT bone flare was observed in 4 of 42 (10%) evaluable patients. In univariate analysis, PSA decline and FCH-PET/CT response predicted PFS, while PSA decline and FCH-PET/CT (progression vs non progression) predicted OS. In multivariate analysis, only FCH-PET/CT (progression vs nonprogression) remained significant for PFS and OS (p = 0.022 and p = 0.027, respectively). Conclusion: Early FCH-PET/CT can predict clinical outcome in CRPC beyond PSA response. These data support further studies on FCH-PET/CT for abiraterone monitoring and outcome prediction in patients with CRPC. PMID:25504434

  20. Pre-radiotherapy FDG PET predicts radiation pneumonitis in lung cancer

    PubMed Central

    2014-01-01

    Background A retrospective analysis is performed to determine if pre-treatment [18 F]-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) image derived parameters can predict radiation pneumonitis (RP) clinical symptoms in lung cancer patients. Methods and Materials We retrospectively studied 100 non-small cell lung cancer (NSCLC) patients who underwent FDG PET/CT imaging before initiation of radiotherapy (RT). Pneumonitis symptoms were evaluated using the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv4) from the consensus of 5 clinicians. Using the cumulative distribution of pre-treatment standard uptake values (SUV) within the lungs, the 80th to 95th percentile SUV values (SUV80 to SUV95) were determined. The effect of pre-RT FDG uptake, dose, patient and treatment characteristics on pulmonary toxicity was studied using multiple logistic regression. Results The study subjects were treated with 3D conformal RT (n = 23), intensity modulated RT (n = 64), and proton therapy (n = 13). Multiple logistic regression analysis demonstrated that elevated pre-RT lung FDG uptake on staging FDG PET was related to development of RP symptoms after RT. A patient of average age and V30 with SUV95 = 1.5 was an estimated 6.9 times more likely to develop grade ≥ 2 radiation pneumonitis when compared to a patient with SUV95 = 0.5 of the same age and identical V30. Receiver operating characteristic curve analysis showed the area under the curve was 0.78 (95% CI = 0.69 – 0.87). The CT imaging and dosimetry parameters were found to be poor predictors of RP symptoms. Conclusions The pretreatment pulmonary FDG uptake, as quantified by the SUV95, predicted symptoms of RP in this study. Elevation in this pre-treatment biomarker identifies a patient group at high risk for post-treatment symptomatic RP. PMID:24625207

  1. Response Assessment and Prediction in Esophageal Cancer Patients via F-18 FDG PET/CT Scans

    NASA Astrophysics Data System (ADS)

    Higgins, Kyle J.

    Purpose: The purpose of this study is to utilize F-18 FDG PET/CT scans to determine an indicator for the response of esophageal cancer patients during radiation therapy. There is a need for such an indicator since local failures are quite common in esophageal cancer patients despite modern treatment techniques. If an indicator is found, a patient's treatment strategy may be altered to possibly improve the outcome. This is investigated with various standard uptake volume (SUV) metrics along with image texture features. The metrics and features showing the most promise and indicating response are used in logistic regression analysis to find an equation for the prediction of response. Materials and Methods: 28 patients underwent F-18 FDG PET/CT scans prior to the start of radiation therapy (RT). A second PET/CT scan was administered following the delivery of ~32 Gray (Gy) of dose. A physician contoured gross tumor volume (GTV) was used to delineate a PET based GTV (GTV-pre-PET) based on a threshold of >40% and >20% of the maximum SUV value in the GTV. Deformable registration was used in VelocityAI software to register the pre-treatment and intra-treatment CT scans so that the GTV-pre-PET contours could be transferred from the pre to intra scans (GTV-intra-PET). The fractional decrease in the maximum, mean, volume to the highest intensity 10%-90%, and combination SUV metrics of the significant previous SUV metrics were compared to post-treatment pathologic response for an indication of response. Next for the >40% threshold, texture features based on a neighborhood gray-tone dimension matrix (NGTDM) were analyzed. The fractional decrease in coarseness, contrast, busyness, complexity, and texture strength were compared to the pathologic response of the patients. From these previous two types of analysis, SUV and texture features, the two most significant results were used in logistic regression analysis to find an equation to predict the probability of a non

  2. 18F-EF5 PET Is Predictive of Response to Fractionated Radiotherapy in Preclinical Tumor Models

    PubMed Central

    Ali, Rehan; Apte, Sandeep; Vilalta, Marta; Subbarayan, Murugesan; Miao, Zheng; Chin, Frederick T.; Graves, Edward E.

    2015-01-01

    We evaluated the relationship between pre-treatment positron emission tomography (PET) using the hypoxic tracer 18F-[2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3- pentafluoropropyl) acetamide] (18F-EF5) and the response of preclinical tumor models to a range of fractionated radiotherapies. Subcutaneous HT29, A549 and RKO tumors grown in nude mice were imaged using 18F-EF5 positron emission tomography (PET) in order to characterize the extent and heterogeneity of hypoxia in these systems. Based on these results, 80 A549 tumors were subsequently grown and imaged using 18F-EF5 PET, and then treated with one, two, or four fraction radiation treatments to a total dose of 10–40 Gy. Response was monitored by serial caliper measurements of tumor volume. Longitudinal post-treatment 18F-EF5 PET imaging was performed on a subset of tumors. Terminal histologic analysis was performed to validate 18F-EF5 PET measures of hypoxia. EF5-positive tumors responded more poorly to low dose single fraction irradiation relative to EF5-negative tumors, however both groups responded similarly to larger single fraction doses. Irradiated tumors exhibited reduced 18F-EF5 uptake one month after treatment compared to control tumors. These findings indicate that pre- treatment 18F-EF5 PET can predict the response of tumors to single fraction radiation treatment. However, increasing the number of fractions delivered abrogates the difference in response between tumors with high and low EF5 uptake pre-treatment, in agreement with traditional radiobiology. PMID:26431331

  3. 18F-EF5 PET Is Predictive of Response to Fractionated Radiotherapy in Preclinical Tumor Models.

    PubMed

    Ali, Rehan; Apte, Sandeep; Vilalta, Marta; Subbarayan, Murugesan; Miao, Zheng; Chin, Frederick T; Graves, Edward E

    2015-01-01

    We evaluated the relationship between pre-treatment positron emission tomography (PET) using the hypoxic tracer 18F-[2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3- pentafluoropropyl) acetamide] (18F-EF5) and the response of preclinical tumor models to a range of fractionated radiotherapies. Subcutaneous HT29, A549 and RKO tumors grown in nude mice were imaged using 18F-EF5 positron emission tomography (PET) in order to characterize the extent and heterogeneity of hypoxia in these systems. Based on these results, 80 A549 tumors were subsequently grown and imaged using 18F-EF5 PET, and then treated with one, two, or four fraction radiation treatments to a total dose of 10-40 Gy. Response was monitored by serial caliper measurements of tumor volume. Longitudinal post-treatment 18F-EF5 PET imaging was performed on a subset of tumors. Terminal histologic analysis was performed to validate 18F-EF5 PET measures of hypoxia. EF5-positive tumors responded more poorly to low dose single fraction irradiation relative to EF5-negative tumors, however both groups responded similarly to larger single fraction doses. Irradiated tumors exhibited reduced 18F-EF5 uptake one month after treatment compared to control tumors. These findings indicate that pre- treatment 18F-EF5 PET can predict the response of tumors to single fraction radiation treatment. However, increasing the number of fractions delivered abrogates the difference in response between tumors with high and low EF5 uptake pre-treatment, in agreement with traditional radiobiology. PMID:26431331

  4. Predicting conversion from MCI to AD with FDG-PET brain images at different prodromal stages.

    PubMed

    Cabral, Carlos; Morgado, Pedro M; Campos Costa, Durval; Silveira, Margarida

    2015-03-01

    Early diagnosis of Alzheimer disease (AD), while still at the stage known as mild cognitive impairment (MCI), is important for the development of new treatments. However, brain degeneration in MCI evolves with time and differs from patient to patient, making early diagnosis a very challenging task. Despite these difficulties, many machine learning techniques have already been used for the diagnosis of MCI and for predicting MCI to AD conversion, but the MCI group used in previous works is usually very heterogeneous containing subjects at different stages. The goal of this paper is to investigate how the disease stage impacts on the ability of machine learning methodologies to predict conversion. After identifying the converters and estimating the time of conversion (TC) (using neuropsychological test scores), we devised 5 subgroups of MCI converters (MCI-C) based on their temporal distance to the conversion instant (0, 6, 12, 18 and 24 months before conversion). Next, we used the FDG-PET images of these subgroups and trained classifiers to distinguish between the MCI-C at different stages and stable non-converters (MCI-NC). Our results show that MCI to AD conversion can be predicted as early as 24 months prior to conversion and that the discriminative power of the machine learning methods decreases with the increasing temporal distance to the TC, as expected. These findings were consistent for all the tested classifiers. Our results also show that this decrease arises from a reduction in the information contained in the regions used for classification and by a decrease in the stability of the automatic selection procedure. PMID:25625698

  5. Post-radioembolization yttrium-90 PET/CT - part 2: dose-response and tumor predictive dosimetry for resin microspheres

    PubMed Central

    2013-01-01

    Background Coincidence imaging of low-abundance yttrium-90 (90Y) internal pair production by positron emission tomography with integrated computed tomography (PET/CT) achieves high-resolution imaging of post-radioembolization microsphere biodistribution. Part 2 analyzes tumor and non-target tissue dose-response by 90Y PET quantification and evaluates the accuracy of tumor 99mTc macroaggregated albumin (MAA) single-photon emission computed tomography with integrated CT (SPECT/CT) predictive dosimetry. Methods Retrospective dose quantification of 90Y resin microspheres was performed on the same 23-patient data set in part 1. Phantom studies were performed to assure quantitative accuracy of our time-of-flight lutetium-yttrium-oxyorthosilicate system. Dose-responses were analyzed using 90Y dose-volume histograms (DVHs) by PET voxel dosimetry or mean absorbed doses by Medical Internal Radiation Dose macrodosimetry, correlated to follow-up imaging or clinical findings. Intended tumor mean doses by predictive dosimetry were compared to doses by 90Y PET. Results Phantom studies demonstrated near-perfect detector linearity and high tumor quantitative accuracy. For hepatocellular carcinomas, complete responses were generally achieved at D70 > 100 Gy (D70, minimum dose to 70% tumor volume), whereas incomplete responses were generally at D70 < 100 Gy; smaller tumors (<80 cm3) achieved D70 > 100 Gy more easily than larger tumors. There was complete response in a cholangiocarcinoma at D70 90 Gy and partial response in an adrenal gastrointestinal stromal tumor metastasis at D70 53 Gy. In two patients, a mean dose of 18 Gy to the stomach was asymptomatic, 49 Gy caused gastritis, 65 Gy caused ulceration, and 53 Gy caused duodenitis. In one patient, a bilateral kidney mean dose of 9 Gy (V20 8%) did not cause clinically relevant nephrotoxicity. Under near-ideal dosimetric conditions, there was excellent correlation between intended tumor mean doses by predictive dosimetry and those

  6. The Clinical Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography (PET) to Predict Oncologic Outcomes and PET-Based Radiotherapeutic Considerations in Locally Advanced Nasopharyngeal Carcinoma

    PubMed Central

    Yoon, Hong In; Kim, Kyung Hwan; Lee, Jeongshim; Roh, Yun Ho; Yun, Mijin; Cho, Byoung Chul; Lee, Chang Geol; Keum, Ki Chang

    2016-01-01

    Purpose We investigated 18F-fluorodeoxyglucose positron emission tomography (PET)-derived parameters as prognostic indices for disease progression and survival in locally advanced nasopharyngeal carcinoma (NPC) and the effect of high-dose radiotherapy for a subpopulation with PET-based poor prognoses. Materials and Methods Ninety-seven stage III and Iva-b NPC patients who underwent definitive treatment and PET were reviewed. For each primary, nodal, and whole tumor, maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) were evaluated. Results Based on the C-index (0.666) and incremental area under the curve (0.669), the whole tumor TLGwas the most useful predictorfor progression-free survival (PFS); thewhole tumor TLG cut-off value showing the best predictive performance was 322.7. In multivariate analysis, whole tumor TLG was a significant prognostic factor for PFS (hazard ratio [HR], 0.3; 95% confidence interval [CI], 0.14 to 0.65; p=0.002) and OS (HR, 0.29; 95% CI, 0.11 to 0.79; p=0.02). Patients with low whole tumor TLG showed the higher 5-year PFS in the subgroup for only patients receiving intensity modulated radiotherapy (77.4% vs. 53.0%, p=0.01). In the subgroup of patients with high whole tumor TLG, patients receiving an EQD2 ≥ 70 Gy showed significantly greater complete remission rates (71.4% vs. 33.3%, p=0.03) and higher 5-year OS (74.7% vs. 19.6%, p=0.02). Conclusion Our findings demonstrated that whole tumor TLG could be an independent prognostic factor and high-dose radiotherapy could improve outcomes for NPC showing high whole tumor TLG. PMID:26693913

  7. Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment

    PubMed Central

    Brendel, M; Jaworska, A; Herms, J; Trambauer, J; Rötzer, C; Gildehaus, F-J; Carlsen, J; Cumming, P; Bylund, J; Luebbers, T; Bartenstein, P; Steiner, H; Haass, C; Baumann, K; Rominger, A

    2015-01-01

    In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [18F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5–a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg−1) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover

  8. Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment.

    PubMed

    Brendel, M; Jaworska, A; Herms, J; Trambauer, J; Rötzer, C; Gildehaus, F-J; Carlsen, J; Cumming, P; Bylund, J; Luebbers, T; Bartenstein, P; Steiner, H; Haass, C; Baumann, K; Rominger, A

    2015-10-01

    In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [(18)F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg(-1)) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover

  9. Value of sequential 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in prediction of the overall survival of esophageal cancer patients treated with chemoradiotherapy

    PubMed Central

    Li, Yimin; Lin, Qin; Luo, Zuoming; Zhao, Long; Zhu, Luchao; Sun, Long; Wu, Hua

    2015-01-01

    This study is to investigate the value of the metabolic parameters measured by sequential FDG PET/CT in predicting the overall survival of patients with esophageal squamous cell carcinoma (ESCC). A total of 160 patients who were newly diagnosed as ESCC patients and treated with chemoradiotherapy were included in this study. The FDG PET/CT was carried out prior to radiotherapy (PET1), when the cumulative dose of radiotherapy reached 50 Gy (PET2), at the end of radiotherapy (PET3) and 1 month after radiotherapy (PET4). The max of the standard uptake value (SUVmax) of the primary tumor, the metabolic tumor volume (MTV) and the total lesion glycolisis (TLG) prior to treatment were measured. The correlation of the measured parameters and the derived parameters of SUVmax with the overall survival was analyzed. The relatively reduced percentage of the SUVmax of PET3 and PET4 to the SUVmax of PET1 and PET2, had predictive value for the overall survival. The area under researcher operation curve (ROC) was between 0.62 and 0.73 (P < 0.01). The MTV and TLG prior to treatment might be used to predict the overall survival, and the area under ROC were both 0.69 (P < 0.001). Sequential FDG PET/CT scanning is useful to predict the overall survival of chemoradiotherapy for ESCC. The metabolic parameters and the derived parameters of FDG PET/CT have predictive values for overall survival. PMID:26379889

  10. Value of sequential 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in prediction of the overall survival of esophageal cancer patients treated with chemoradiotherapy.

    PubMed

    Li, Yimin; Lin, Qin; Luo, Zuoming; Zhao, Long; Zhu, Luchao; Sun, Long; Wu, Hua

    2015-01-01

    This study is to investigate the value of the metabolic parameters measured by sequential FDG PET/CT in predicting the overall survival of patients with esophageal squamous cell carcinoma (ESCC). A total of 160 patients who were newly diagnosed as ESCC patients and treated with chemoradiotherapy were included in this study. The FDG PET/CT was carried out prior to radiotherapy (PET1), when the cumulative dose of radiotherapy reached 50 Gy (PET2), at the end of radiotherapy (PET3) and 1 month after radiotherapy (PET4). The max of the standard uptake value (SUVmax) of the primary tumor, the metabolic tumor volume (MTV) and the total lesion glycolisis (TLG) prior to treatment were measured. The correlation of the measured parameters and the derived parameters of SUVmax with the overall survival was analyzed. The relatively reduced percentage of the SUVmax of PET3 and PET4 to the SUVmax of PET1 and PET2, had predictive value for the overall survival. The area under researcher operation curve (ROC) was between 0.62 and 0.73 (P < 0.01). The MTV and TLG prior to treatment might be used to predict the overall survival, and the area under ROC were both 0.69 (P < 0.001). Sequential FDG PET/CT scanning is useful to predict the overall survival of chemoradiotherapy for ESCC. The metabolic parameters and the derived parameters of FDG PET/CT have predictive values for overall survival. PMID:26379889

  11. The predictive value of early behavioural assessments in pet dogs--a longitudinal study from neonates to adults.

    PubMed

    Riemer, Stefanie; Müller, Corsin; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

    2014-01-01

    Studies on behavioural development in domestic dogs are of relevance for matching puppies with the right families, identifying predispositions for behavioural problems at an early stage, and predicting suitability for service dog work, police or military service. The literature is, however, inconsistent regarding the predictive value of tests performed during the socialisation period. Additionally, some practitioners use tests with neonates to complement later assessments for selecting puppies as working dogs, but these have not been validated. We here present longitudinal data on a cohort of Border collies, followed up from neonate age until adulthood. A neonate test was conducted with 99 Border collie puppies aged 2-10 days to assess activity, vocalisations when isolated and sucking force. At the age of 40-50 days, 134 puppies (including 93 tested as neonates) were tested in a puppy test at their breeders' homes. All dogs were adopted as pet dogs and 50 of them participated in a behavioural test at the age of 1.5 to 2 years with their owners. Linear mixed models found little correspondence between individuals' behaviour in the neonate, puppy and adult test. Exploratory activity was the only behaviour that was significantly correlated between the puppy and the adult test. We conclude that the predictive validity of early tests for predicting specific behavioural traits in adult pet dogs is limited. PMID:25003341

  12. The Predictive Value of Early Behavioural Assessments in Pet Dogs – A Longitudinal Study from Neonates to Adults

    PubMed Central

    Riemer, Stefanie; Müller, Corsin; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

    2014-01-01

    Studies on behavioural development in domestic dogs are of relevance for matching puppies with the right families, identifying predispositions for behavioural problems at an early stage, and predicting suitability for service dog work, police or military service. The literature is, however, inconsistent regarding the predictive value of tests performed during the socialisation period. Additionally, some practitioners use tests with neonates to complement later assessments for selecting puppies as working dogs, but these have not been validated. We here present longitudinal data on a cohort of Border collies, followed up from neonate age until adulthood. A neonate test was conducted with 99 Border collie puppies aged 2–10 days to assess activity, vocalisations when isolated and sucking force. At the age of 40–50 days, 134 puppies (including 93 tested as neonates) were tested in a puppy test at their breeders' homes. All dogs were adopted as pet dogs and 50 of them participated in a behavioural test at the age of 1.5 to 2 years with their owners. Linear mixed models found little correspondence between individuals' behaviour in the neonate, puppy and adult test. Exploratory activity was the only behaviour that was significantly correlated between the puppy and the adult test. We conclude that the predictive validity of early tests for predicting specific behavioural traits in adult pet dogs is limited. PMID:25003341

  13. A novel metric for quantification of homogeneous and heterogeneous tumors in PET for enhanced clinical outcome prediction

    NASA Astrophysics Data System (ADS)

    Rahmim, Arman; Schmidtlein, C. Ross; Jackson, Andrew; Sheikhbahaei, Sara; Marcus, Charles; Ashrafinia, Saeed; Soltani, Madjid; Subramaniam, Rathan M.

    2016-01-01

    Oncologic PET images provide valuable information that can enable enhanced prognosis of disease. Nonetheless, such information is simplified significantly in routine clinical assessment to meet workflow constraints. Examples of typical FDG PET metrics include: (i) SUVmax, (2) total lesion glycolysis (TLG), and (3) metabolic tumor volume (MTV). We have derived and implemented a novel metric for tumor quantification, inspired in essence by a model of generalized equivalent uniform dose as used in radiation therapy. The proposed metric, denoted generalized effective total uptake (gETU), is attractive as it encompasses the abovementioned commonly invoked metrics, and generalizes them, for both homogeneous and heterogeneous tumors, using a single parameter a. We evaluated this new metric for improved overall survival (OS) prediction on two different baseline FDG PET/CT datasets: (a) 113 patients with squamous cell cancer of the oropharynx, and (b) 72 patients with locally advanced pancreatic adenocarcinoma. Kaplan-Meier survival analysis was performed, where the subjects were subdivided into two groups using the median threshold, from which the hazard ratios (HR) were computed in Cox proportional hazards regression. For the oropharyngeal cancer dataset, MTV, TLG, SUVmax, SUVmean and SUVpeak produced HR values of 1.86, 3.02, 1.34, 1.36 and 1.62, while the proposed gETU metric for a  = 0.25 (greater emphasis on volume information) enabled significantly enhanced OS prediction with HR  =  3.94. For the pancreatic cancer dataset, MTV, TLG, SUVmax, SUVmean and SUVpeak resulted in HR values of 1.05, 1.25, 1.42, 1.45 and 1.52, while gETU at a  = 3.2 (greater emphasis on SUV information) arrived at an improved HR value of 1.61. Overall, the proposed methodology allows placement of differing degrees of emphasis on tumor volume versus uptake for different types of tumors to enable enhanced clinical outcome prediction.

  14. WE-E-17A-03: FDG-PET-Based Radiomics to Predict Local Control and Survival Following Radiotherapy

    SciTech Connect

    Oh, J; Apte, A; Folkerts, M; Kohutek, Z; Wu, A; Rimmer, A; Lee, N; Deasy, J

    2014-06-15

    Purpose: An exploding field in cancer research is “radiomics,” based on the hypothesis that there is statistical (hidden) information in medical images that is prognostic or predictive of outcomes. Our group has developed an efficient pipeline to extract and analyze quantitative image features from medical images as related to outcomes or diagnosis. In this work, we summarize our previous studies with positron emission tomography (PET) images and show the potential of the use of radiomics for outcomes research. Methods: We analyzed two cancer datasets, each consisting of pre-radiotherapy-treatment PET scans: 163 T1-2N0M0 non-small cell lung cancer (NSCLC) patients and 174 head and neck (H and N) cancer patients with stage III–IV. The PET scans were converted to Computational Environment for Radiological Research (CERR) format, and CERR was used to generate 24 shape, texture, and intensity-histogram based image features. Data-mining and logistic regression methods were then used to model local failure (LF) and overall survival (OS). Unbiased estimates of performance were generated using leave-one-out cross-validation (LOOCV). Results: For predicting LF, the models with biologically equivalent dose (BED) and TLG (metabolic tumor volume (MTV) x SUVmean) in NSCLC, and skewness and MTV in H and N, achieved the best performance with AUC=0.818 (p<0.0001) and AUC=0.826 (p=0.0002), respectively. For predicting OS, the models with kurtosis and volume in NSCLC and SUVmax and homogeneity in H and N achieved the best performance with AUC=0.706 (p<0.0001) and AUC=0.656 (p=0.0003), respectively. On LOOCV, all these models retained significant predictive power. Interestingly, MTV was highly correlated with LF in both sites. Conclusion: PET-based imaged features are promising tools for improving treatment management decision making. Much more research is needed to identify optimal radiomics metrics and to correlate imaging phenotype with other clinical or genomic information.

  15. Predictive value of early 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) during salvage chemotherapy in relapsing/refractory Hodgkin lymphoma (HL) treated with high-dose chemotherapy.

    PubMed

    Castagna, Luca; Bramanti, Stefania; Balzarotti, Monica; Sarina, Barbara; Todisco, Elisabetta; Anastasia, Antonella; Magagnoli, Massimo; Mazza, Rita; Nozza, Andrea; Giordano, Laura; Rodari, Marcello; Rinifilo, Eva; Chiti, Arturo; Santoro, Armando

    2009-05-01

    This retrospective study evaluated whether early 2-[fluorine-18]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) after two cycles of salvage chemotherapy (PET2) could predict survival after high-dose chemotherapy (HDC). Twenty-four Hodgkin lymphoma (HL) patients were included. PET2 was negative in 58% and positive in 42% of patients. Ninety per cent of patients (9/10) with positive PET2 relapsed after HDC while all but one patient with negative PET2 maintained a complete remission. The 2-year progression-free survival was 93% vs. 10% for patients with negative and positive PET2, respectively (P < 0.001). This study shows that interim PET can predict the outcome after high-dose chemotherapy in HL patients. PMID:19344403

  16. Can technical characteristics predict clinical performance in PET/CT imaging? A correlation study for thyroid cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Kallergi, Maria; Menychtas, Dimitrios; Georgakopoulos, Alexandros; Pianou, Nikoletta; Metaxas, Marinos; Chatziioannou, Sofia

    2013-03-01

    The purpose of this study was to determine whether image characteristics could be used to predict the outcome of ROC studies in PET/CT imaging. Patients suspected for recurrent thyroid cancer underwent a standard whole body (WB) examination and an additional high-resolution head-and-neck (HN) F18-FDG PET/CT scan. The value of the latter was determined with an ROC study, the results of which showed that the WB+HN combination was better than WB alone for thyroid cancer detection and diagnosis. Following the ROC experiment, the WB and HN images of confirmed benign or malignant thyroid disease were analyzed and first and second order textural features were determined. Features included minimum, mean, and maximum intensity, as well as contrast in regions of interest encircling the thyroid lesions. Lesion size and standard uptake values (SUV) were also determined. Bivariate analysis was applied to determine relationships between WB and HN features and between observer ROC responses and the various feature values. The two sets showed significant associations in the values of SUV, contrast, and lesion size. They were completely different when the intensities were considered; no relationship was found between the WB minimum, maximum, and mean ROI values and their HN counterparts. SUV and contrast were the strongest predictors of ROC performance on PET/CT examinations of thyroid cancer. The high resolution HN images seem to enhance these relationships but without a single dramatic effect as was projected from the ROC results. A combination of features from both WB and HN datasets may possibly be a more robust predictor of ROC performance.

  17. A radiomics model from joint FDG-PET and MRI texture features for the prediction of lung metastases in soft-tissue sarcomas of the extremities

    NASA Astrophysics Data System (ADS)

    Vallières, M.; Freeman, C. R.; Skamene, S. R.; El Naqa, I.

    2015-07-01

    This study aims at developing a joint FDG-PET and MRI texture-based model for the early evaluation of lung metastasis risk in soft-tissue sarcomas (STSs). We investigate if the creation of new composite textures from the combination of FDG-PET and MR imaging information could better identify aggressive tumours. Towards this goal, a cohort of 51 patients with histologically proven STSs of the extremities was retrospectively evaluated. All patients had pre-treatment FDG-PET and MRI scans comprised of T1-weighted and T2-weighted fat-suppression sequences (T2FS). Nine non-texture features (SUV metrics and shape features) and forty-one texture features were extracted from the tumour region of separate (FDG-PET, T1 and T2FS) and fused (FDG-PET/T1 and FDG-PET/T2FS) scans. Volume fusion of the FDG-PET and MRI scans was implemented using the wavelet transform. The influence of six different extraction parameters on the predictive value of textures was investigated. The incorporation of features into multivariable models was performed using logistic regression. The multivariable modeling strategy involved imbalance-adjusted bootstrap resampling in the following four steps leading to final prediction model construction: (1) feature set reduction; (2) feature selection; (3) prediction performance estimation; and (4) computation of model coefficients. Univariate analysis showed that the isotropic voxel size at which texture features were extracted had the most impact on predictive value. In multivariable analysis, texture features extracted from fused scans significantly outperformed those from separate scans in terms of lung metastases prediction estimates. The best performance was obtained using a combination of four texture features extracted from FDG-PET/T1 and FDG-PET/T2FS scans. This model reached an area under the receiver-operating characteristic curve of 0.984 ± 0.002, a sensitivity of 0.955 ± 0.006, and a specificity of 0.926 ± 0.004 in bootstrapping

  18. A radiomics model from joint FDG-PET and MRI texture features for the prediction of lung metastases in soft-tissue sarcomas of the extremities.

    PubMed

    Vallières, M; Freeman, C R; Skamene, S R; El Naqa, I

    2015-07-21

    This study aims at developing a joint FDG-PET and MRI texture-based model for the early evaluation of lung metastasis risk in soft-tissue sarcomas (STSs). We investigate if the creation of new composite textures from the combination of FDG-PET and MR imaging information could better identify aggressive tumours. Towards this goal, a cohort of 51 patients with histologically proven STSs of the extremities was retrospectively evaluated. All patients had pre-treatment FDG-PET and MRI scans comprised of T1-weighted and T2-weighted fat-suppression sequences (T2FS). Nine non-texture features (SUV metrics and shape features) and forty-one texture features were extracted from the tumour region of separate (FDG-PET, T1 and T2FS) and fused (FDG-PET/T1 and FDG-PET/T2FS) scans. Volume fusion of the FDG-PET and MRI scans was implemented using the wavelet transform. The influence of six different extraction parameters on the predictive value of textures was investigated. The incorporation of features into multivariable models was performed using logistic regression. The multivariable modeling strategy involved imbalance-adjusted bootstrap resampling in the following four steps leading to final prediction model construction: (1) feature set reduction; (2) feature selection; (3) prediction performance estimation; and (4) computation of model coefficients. Univariate analysis showed that the isotropic voxel size at which texture features were extracted had the most impact on predictive value. In multivariable analysis, texture features extracted from fused scans significantly outperformed those from separate scans in terms of lung metastases prediction estimates. The best performance was obtained using a combination of four texture features extracted from FDG-PET/T1 and FDG-PET/T2FS scans. This model reached an area under the receiver-operating characteristic curve of 0.984 ± 0.002, a sensitivity of 0.955 ± 0.006, and a specificity of 0.926 ± 0.004 in bootstrapping

  19. Migration of antimony from PET trays into food simulant and food: determination of Arrhenius parameters and comparison of predicted and measured migration data

    PubMed Central

    Haldimann, M.; Alt, A.; Blanc, A.; Brunner, K.; Sager, F.; Dudler, V.

    2013-01-01

    Migration experiments with small sheets cut out from ovenable PET trays were performed in two-sided contact with 3% acetic acid as food simulant at various temperatures. The fraction of diffusible antimony (Sb) was estimated to be 62% in the PET sample under study. Apparent diffusion coefficients of Sb in PET trays were determined experimentally. Measurement of migration between 20 and 150°C yielded a linear Arrhenius plot over a wide temperature range from which the activation energy (Ea) of 188 ± 36 kJ mol−1 and the pre-exponential factor (D0) of 3.6 × 1014 cm2s−1 were determined for diffusing Sb species. Ea was similar to previously reported values for PET bottles obtained with a different experimental approach. Ea and D0 were applied as model parameters in migration modelling software for predicting the Sb transfer in real food. Ready meals intended for preparation in a baking oven were heated in the PET trays under study and the actual Sb migration into the food phase was measured by isotope dilution ICP-MS. It was shown that the predictive modelling reproduces correctly experimental data. PMID:23286325

  20. Establishment of the prediction table of parturition day with ultrasonography in small pet dogs.

    PubMed

    Son, C H; Jeong, K A; Kim, J H; Park, I C; Kim, S H; Lee, C S

    2001-07-01

    To establish a prediction table of parturition day the real-time B-mode ultrasonographic examinations were performed in the 8 pregnant Malteses and 10 Yorkshire terriers (total pups, 25 and 38 pups, respectively) from 18 days of gestation until the parturition. Ovulation was designated the first day of gestation (day 0). Extra fetal and fetal structures were measured from all conceptues. The parameters that exhibited the best correlation to parturition were used to compile a prediction table of parturition day. To testify the precision of the prediction table of parturition day, the 15 pregnant Malteses (48 pups) and 13 pregnant Yorkshire terriers (42 pups) with unknown mating time were examined using ultrasonography. Inner chorionic cavity diameter on days 18 to 37 and fetal head diameter on day 38 to parturition that showed the best correlation to gestational age were the most pertinent to the estimation of gestational age and the prediction of parturition day. The two parameters were used to compile a prediction table of parturition with averaged regression equations. In verificational examinations, with the exception of I Yorkshire terrier (3.6%) having 1 fetus, 18 of 28 bitches (64.3%) delivered exactly on the date predicted and 9 of 28 bitches (32.1%) delivered within I day of the date predicted. Therefore, the prediction table of parturition day seems to be a useful tool of the prediction of parturition day in practice. PMID:11503898

  1. Progression-free and overall survival in metastatic castration-resistant prostate cancer treated with abiraterone acetate can be predicted with serial C11-acetate PET/CT

    PubMed Central

    Farnebo, Jacob; Wadelius, Agnes; Sandström, Per; Nilsson, Sten; Jacobsson, Hans; Blomqvist, Lennart; Ullén, Anders

    2016-01-01

    Abstract In this retrospective study, we evaluated the benefit of repeated carbon 11 (C11)-acetate positron emission tomography/computed tomography (PET/CT) to assess response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA). A total of 30 patients with mCRPC were monitored with C11-acetate PET/CT and PSA levels during their treatment with AA. Retrospective evaluation of their response was made after 102 days (median; range 70–155) of treatment. Statistical analyses were employed to detect predictors of progression-free survival (PFS) and overall survival (OS), and potential correlation between serum levels of PSA, standardized uptake values (SUVpeak), and bone lesion index measured from PET were investigated. At follow-up 10 patients exhibited partial response (PR), 10 progressive disease (PD), and 10 stable disease (SD), as assessed by PET/CT. In survival analysis, both PR and PD were significantly associated with PFS and OS. CT response was also associated with OS, but only 19/30 patients demonstrated a lesion meeting target lesion criteria according to RECIST 1.1. No PET/CT baseline characteristic was significantly associated with PFS or OS. A PSA response (reduction in the level by >50%) could also predict PFS and OS. In the subgroup lacking a PSA response, those with PD had significantly shorter OS than those with PR or SD. PFS and OS in patients with mCRPC treated with AA can be predicted from repeated C11-acetate PET/CT. This may be of particular clinical value in patients who do not exhibit a PSA response to treatment. PMID:27495034

  2. WE-E-17A-02: Predictive Modeling of Outcome Following SABR for NSCLC Based On Radiomics of FDG-PET Images

    SciTech Connect

    Li, R; Aguilera, T; Shultz, D; Rubin, D; Diehn, M; Loo, B

    2014-06-15

    Purpose: This study aims to develop predictive models of patient outcome by extracting advanced imaging features (i.e., Radiomics) from FDG-PET images. Methods: We acquired pre-treatment PET scans for 51 stage I NSCLC patients treated with SABR. We calculated 139 quantitative features from each patient PET image, including 5 morphological features, 8 statistical features, 27 texture features, and 100 features from the intensity-volume histogram. Based on the imaging features, we aim to distinguish between 2 risk groups of patients: those with regional failure or distant metastasis versus those without. We investigated 3 pattern classification algorithms: linear discriminant analysis (LDA), naive Bayes (NB), and logistic regression (LR). To avoid the curse of dimensionality, we performed feature selection by first removing redundant features and then applying sequential forward selection using the wrapper approach. To evaluate the predictive performance, we performed 10-fold cross validation with 1000 random splits of the data and calculated the area under the ROC curve (AUC). Results: Feature selection identified 2 texture features (homogeneity and/or wavelet decompositions) for NB and LR, while for LDA SUVmax and one texture feature (correlation) were identified. All 3 classifiers achieved statistically significant improvements over conventional PET imaging metrics such as tumor volume (AUC = 0.668) and SUVmax (AUC = 0.737). Overall, NB achieved the best predictive performance (AUC = 0.806). This also compares favorably with MTV using the best threshold at an SUV of 11.6 (AUC = 0.746). At a sensitivity of 80%, NB achieved 69% specificity, while SUVmax and tumor volume only had 36% and 47% specificity. Conclusion: Through a systematic analysis of advanced PET imaging features, we are able to build models with improved predictive value over conventional imaging metrics. If validated in a large independent cohort, the proposed techniques could potentially aid in

  3. MO-G-BRF-02: Enhancement of Texture-Based Metastasis Prediction Models Via the Optimization of PET/MRI Acquisition Protocols

    SciTech Connect

    Vallieres, M; Laberge, S; Levesque I, R; El Naqa, I

    2014-06-15

    Purpose: We have previously identified a prediction model of lung metastases at diagnosis of soft-tissue sarcomas (STS) that is composed of two textural features extracted from FDG-PET and T1-weighted (T1w) MRI scans. The goal of this study is to evaluate whether the optimization in FDGPET and MRI acquisition parameters would enhance the prediction performance of texture-based models. Methods: Ten FDG-PET and T1w- MRI digitized tumor models were generated from imaging data of STS patients who underwent pre-treatment clinical scans between 2005 and 2011. Five of ten patients eventually developed lung metastases. Numerically simulated MR images were produced using echo times (TE) of 2 and 4 times the nominal clinical parameter (TEc), and repetition times (TR) of 0.5, 0.67, 1.5 and 2 times the nominal clinical parameter (TRc) found in the DICOM headers (TEc range: 9–13 ms, TRc range: 410-667 ms). PET 2D images were simulated using Monte-Carlo and were reconstructed using an ordered-subsets expectation maximization (OSEM) algorithm with 1 to 32 iterations and a post-reconstruction Gaussian filter of 0, 2, 4 or 6 mm width. For all possible combinations of PET and MRI acquisition parameters, the prediction model was constructed using logistic regression with new coefficients, and its associated prediction performance for lung metastases was evaluated using the area under the ROC curve (AUC). Results: The prediction performance over all simulations yielded AUCs ranging from 0.7 to 1. Notably, TR values below or equal to TRc and higher PET post-reconstruction filter widths yielded higher prediction performance. The best results were obtained with a combination of 4*TEc, TRc, 30 OSEM iterations and 2mm filter width. Conclusion: This work indicates that texture-based metastasis prediction models could be improved using optimized choices of FDG-PET and MRI acquisition protocols. This principle could be generalized to other texture-based models.

  4. Modeling and prediction of transmission laser bonding process between titanium coated glass and PET based on response surface methodology

    NASA Astrophysics Data System (ADS)

    Liu, Huixia; Wang, Kai; Li, Pin; Zhang, Cheng; Du, Daozhong; Hu, Yang; Wang, Xiao

    2012-03-01

    Laser bonding parameters play a very significant role in determining the quality of laser transmission bonding between PET films and titanium films coated glass sheets. In order to achieve good bond strength and minimal bond width, three key process parameters affecting the bond quality of transmission laser bonding, namely, laser power, bond speed and film thickness were optimized by response surface methodology in this paper. Response surface methodology (RSM) was used to develop mathematical models between the key process parameters and the desired responses and the central composite design (CCD) was utilized to conduct experimental planning. The samples were tested using an electromechanical universal micro-tester in order to determine bond strength. The morphology of the bonded area was observed with an optical microscope. The interaction effect of main process parameters on bond quality was researched. Design Expert analysis indicated that the best laser power, bond speed and film thickness on bond quality were 11.2 W, 4 mm/s and 163 nm, respectively. Finally, the experimental results are consistent with the predicted, which illustrates that the developed mathematical models can predict the responses adequately.

  5. Advanced [18F]FDG and [11C]flumazenil PET analysis for individual outcome prediction after temporal lobe epilepsy surgery for hippocampal sclerosis

    PubMed Central

    Yankam Njiwa, J.; Gray, K.R.; Costes, N.; Mauguiere, F.; Ryvlin, P.; Hammers, A.

    2014-01-01

    Purpose We have previously shown that an imaging marker, increased periventricular [11C]flumazenil ([11C]FMZ) binding, is associated with failure to become seizure free (SF) after surgery for temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS). Here, we investigated whether increased preoperative periventricular white matter (WM) signal can be detected on clinical [18F]FDG-PET images. We then explored the potential of periventricular FDG WM increases, as well as whole-brain [11C]FMZ and [18F]FDG images analysed with random forest classifiers, for predicting surgery outcome. Methods Sixteen patients with MRI-defined HS had preoperative [18F]FDG and [11C]FMZ-PET. Fifty controls had [18F]FDG-PET (30), [11C]FMZ-PET (41), or both (21). Periventricular WM signal was analysed using Statistical Parametric Mapping (SPM8), and whole-brain image classification was performed using random forests implemented in R (http://www.r-project.org). Surgery outcome was predicted at the group and individual levels. Results At the group level, non-seizure free (NSF) versus SF patients had periventricular increases with both tracers. Against controls, NSF patients showed more prominent periventricular [11C]FMZ and [18F]FDG signal increases than SF patients. All differences were more marked for [11C]FMZ. For individuals, periventricular WM signal increases were seen at optimized thresholds in 5/8 NSF patients for both tracers. For SF patients, 1/8 showed periventricular signal increases for [11C]FMZ, and 4/8 for [18F]FDG. Hence, [18F]FDG had relatively poor sensitivity and specificity. Random forest classification accurately identified 7/8 SF and 7/8 NSF patients using [11C]FMZ images, but only 4/8 SF and 6/8 NSF patients with [18F]FDG. Conclusion This study extends the association between periventricular WM increases and NSF outcome to clinical [18F]FDG-PET, but only at the group level. Whole-brain random forest classification increases [11C]FMZ-PET's performance for predicting

  6. CD68+ cell count, early evaluation with PET and plasma TARC levels predict response in Hodgkin lymphoma.

    PubMed

    Cuccaro, Annarosa; Annunziata, Salvatore; Cupelli, Elisa; Martini, Maurizio; Calcagni, Maria L; Rufini, Vittoria; Giachelia, Manuela; Bartolomei, Francesca; Galli, Eugenio; D'Alò, Francesco; Voso, Maria T; Leone, Giuseppe; Giordano, Alessandro; Larocca, Luigi M; Hohaus, Stefan

    2016-03-01

    Early response evaluation with [(18) F]fluordeoxyglucose (FDG) positron emission tomography after 2 cycles of chemotherapy (interim PET) has been indicated as the strongest predictor for outcome in classical Hodgkin lymphoma (HL). We studied the prognostic role of the number of tumor-infiltrating CD68+ cells and of the plasma levels of TARC (thymus and activation-regulated chemokine) in the context of interim PET in 102 patients with classical HL treated with Adriamycin, Bleomycin, Vinblastine, Dacarbazine (ABVD). After 2 ABVD cycles, interim PET according to Deauville criteria was negative (score 0-3) in 85 patients and positive (score 4-5) in 15 patients (2 patients technically not evaluable). TARC levels were elevated in 89% of patients at diagnosis, and decreased after 2 cycles in 82% of patients. Persistently elevated TARC levels in 18% of patients were significantly associated with a positive PET result (P = 0.007). Strong predictors for progression-free survival (PFS) were a negative interim PET (85% vs. 28%, P < 0.0001) and CD68+ cell counts <5% (89% vs. 67%, P = 0.006), while TARC levels at diagnosis and at interim evaluation had no prognostic role. In multivariate analysis, interim PET, CD68+ cell counts and presence of B-symptoms were independently associated with PFS. We conclude that although TARC levels are a biomarker for early response evaluation, they cannot substitute for interim PET as outcome predictor in HL. The evaluation of CD68 counts and B-symptoms at diagnosis may help to identify low-risk patients regardless positive interim PET. PMID:26758564

  7. Professor Pet.

    ERIC Educational Resources Information Center

    Pet Information Bureau, New York, NY.

    This manual outlines ways in which observation and care of classroom pet animals may be used to enrich the education of elementary school children. Part one deals with the benefits of having pets in the classroom. Part two illustrates ways in which pets can serve as valuable teaching tools and gives examples of lessons in which the use of pets can…

  8. Role of Pre-therapeutic 18F-FDG PET/CT in Guiding the Treatment Strategy and Predicting Prognosis in Patients with Esophageal Carcinoma

    PubMed Central

    Tan, Teik Hin; Boey, Ching Yeen; Lee, Boon Nang

    2016-01-01

    Objective(s): The present study aimed to evaluate the role of pre-therapeutic 18fluorine-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) and maximum standardized uptake value (SUVmax) in guiding the treatment strategy and predicting the prognosis of esophageal carcinoma, using the survival data of the patients. Methods: The present retrospective, cohort study was performed on 40 consecutive patients with esophageal carcinoma (confirmed by endoscopic biopsy), who underwent pre-operative 18F-FDG PET-CT staging between January 2009 and June 2014. All the patients underwent contrast-enhanced CT and non-contrasted 18F-FDG PET-CT evaluations. The patients were followed-up over 12 months to assess the changes in therapeutic strategies. Survival analysis was done considering the primary tumor SUVmax, using the Kaplan–Meier product-limit method. Results: In a total of 40 patients, 18F-FDG PET-CT scan led to changes in disease stage in 26 (65.0%) cases, with upstaging and downstaging reported in 10 (25.0%) and 16 (40.0%) patients, respectively. The management strategy changed from palliative to curative in 10 out of 24 patients and from curative to palliative in 7 out of 16 cases. Based on the 18F-FDG PET-CT scan alone, the median survival of patients in the palliative group was 4.0 (95% CI 3.0-5.0) months, whereas the median survival in the curative group has not been reached, based on the 12-month follow-up. Selection of treatment strategy on the basis of 18F-FDG PET/CT alone was significantly associated with the survival outcomes at nine months (P=0.03) and marginally significant at 12 months (P=0.03). On the basis of SUVmax, the relation between survival and SUVmax was not statistically significant. Conclusion: 18F-FDG PET/CT scan had a significant impact on stage stratification and subsequently, selection of a stage-specific treatment approach and the overall survival outcome in patients with esophageal carcinoma. However, pre

  9. [F-18]-Fluoromisonidazole Quantification of Hypoxia in Human Cancer Patients using Image-derived Blood Surrogate Tissue Reference Regions

    PubMed Central

    Muzi, Mark; Peterson, Lanell M.; O’Sullivan, Janet N.; Fink, James R.; Rajendran, Joseph G.; McLaughlin, Lena J.; Muzi, John P.; Mankoff, David A.; Krohn, Kenneth A.

    2015-01-01

    18F-FMISO is the most widely used PET agent for imaging hypoxia, a condition associated with resistance to tumor therapy. 18F-FMISO equilibrates in normoxic tissues, but is retained under hypoxic conditions because of reduction and binding to macromolecules. A simple tissue-to-blood ratio (TB) is suitable for quantifying hypoxia. A threshold of TB ≥ 1.2 is useful in discriminating the hypoxic volume (HV) of tissue; TBmax is the maximum intensity of the hypoxic region and does not invoke a threshold. Because elimination of blood sampling would simplify clinical use, we tested the validity of using imaging regions as a surrogate for blood sampling. Methods Patients underwent 20 min 18F-FMISO scans during the 90–140 min interval post-injection with venous blood sampling. 223 18F-FMISO patient studies had detectable surrogate blood regions in the field-of-view. Quantitative parameters of hypoxia (TBmax, HV) derived from blood samples were compared to values using surrogate blood regions derived from heart, aorta and/or cerebellum. In a subset of brain cancer patients, parameters from blood samples and from cerebellum were compared for their ability to independently predict outcome. Results Vascular regions of heart showed the highest correlation to measured blood activity (R2 = 0.84). For brain studies, cerebellar activity was similarly correlated to blood samples. In brain cancer patients, Kaplan-Meier analysis showed that image-derived reference regions had nearly identical predictive power as parameters derived from blood, thus obviating the need for venous sampling in these patients. Conclusions Simple static analysis of 18F-FMISO PET captures both the intensity (TBmax) and spatial extent (HV) of tumor hypoxia. An image-derived region to assess blood activity can be used as a surrogate for blood sampling in quantification of hypoxia. PMID:26112020

  10. SU-D-201-02: Prediction of Delivered Dose Based On a Joint Histogram of CT and FDG PET Images

    SciTech Connect

    Park, M; Choi, Y; Cho, A; Hwang, S; Cha, J; Lee, N; Yun, M

    2015-06-15

    Purpose: To investigate whether pre-treatment images can be used in predicting microsphere distribution in tumors. When intra-arterial radioembolization using Y90 microspheres was performed, the microspheres were often delivered non-uniformly within the tumor, which could lead to an inefficient therapy. Therefore, it is important to estimate the distribution of microspheres. Methods: Early arterial phase CT and FDG PET images were acquired for patients with primary liver cancer prior to radioembolization (RE) using Y90 microspheres. Tumor volume was delineated on CT images and fused with FDG PET images. From each voxel (3.9×3.9×3.3 mm3) in the tumor, the Hounsfield unit (HU) from the CT and SUV values from the FDG PET were harvested. We binned both HU and SUV into 11 bins and then calculated a normalized joint-histogram in an 11×11 array.Patients also underwent a post-treatment Y90 PET imaging. Radiation dose for the tumor was estimated using convolution of the Y90 distribution with a dose-point kernel. We also calculated a fraction of the tumor volume that received a radiation dose great than 100Gy. Results: Averaged over 40 patients, 55% of tumor volume received a dose greater than 100Gy (range : 1.1 – 100%). The width of the joint histogram was narrower for patients with a high dose. For patients with a low dose, the width was wider and a larger fraction of tumor volume had low HU. Conclusion: We have shown the pattern of joint histogram of the HU and SUV depends on delivered dose. The patterns can predict the efficacy of uniform intra-arterial delivery of Y90 microspheres.

  11. Early change in glucose metabolic rate measured using FDG-PET in patients with high-grade glioma predicts response to temozolomide but not temozolomide plus radiotherapy

    SciTech Connect

    Charnley, Natalie . E-mail: natalie.charnley@mmic.man.ac.uk; West, Catharine M.; Barnett, Carolyn M.; Brock, Catherine; Bydder, Graeme M.; Glaser, Mark; Newlands, Ed S.; Swindell, Ric; Matthews, Julian; Price, Pat

    2006-10-01

    Purpose: To compare the ability of positron emission tomography (PET) to predict response to temozolomide vs. temozolomide plus radiotherapy. Methods and Materials: Nineteen patients with high-grade glioma (HGG) were studied. Patients with recurrent glioma received temozolomide 75 mg/m{sup 2} daily for 7 weeks (n = 8). Newly diagnosed patients received temozolomide 75 mg/m{sup 2} daily plus radiotherapy 60 Gy/30 fractions over 6 weeks, followed by six cycles of adjuvant temozolomide 200 mg/m{sup 2}/day (Days 1-5 q28) starting 1 month after radiotherapy (n = 11). [{sup 18}F]Fluorodeoxyglucose ([{sup 18}F]FDG) PET scan and magnetic resonance imaging (MRI) were performed at baseline, and 7 and 19 weeks after initiation of temozolomide administration. Changes in glucose metabolic rate (MRGlu) and MRI response were correlated with patient survival. Results: In the temozolomide-alone group, patients who survived >26 vs. {<=}26 weeks showed a greater reduction in MRGlu measured at 7 weeks with median changes of -34% and -4%, respectively (p = 0.02). PET responders, defined as a reduction in MRGlu {>=}25%, survived longer than nonresponders with mean survival times of 75 weeks (95% CI, 34-115 vs. 20 weeks (95% CI, 14-26) (p = 0.0067). In the small group of patients studied, there was no relationship between MRI response and survival (p = 0.52). For patients receiving temozolomide plus radiotherapy, there was no difference in survival between PET responders and nonresponders (p = 0.32). Conclusions: Early changes in MRGlu predict response to temozolomide, but not temozolomide plus radiotherapy.

  12. P11: 18FDG-PET/CT for early prediction of response to first line platinum chemotherapy in advanced thymic epithelial tumors

    PubMed Central

    Palmieri, Giovannella; Ottaviano, Margaret; Del Vecchio, Silvana; Segreto, Sabrina; Tucci, Irene; Damiano, Vincenzo

    2015-01-01

    Background To investigate the value of the metabolic tumor response assessed with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), compared with clinicobiological markers, to predict the response disease to first line platinum based chemotherapy in advanced thymic epithelial tumors (TETs). Methods Twenty patients with diagnosis of TET and stage of disease III and IV sec, Masaoka-Koga, were retrospectively included in this monocentric study. Different pre-treatment clinical, biological and pathological parameters, including histotype sec, WHO 2004 and stage of disease sec, Masaoka-Koga were assessed. Tumor glucose metabolism at baseline and its change after the first line platinum based chemotherapy (from 4 to 6 cycles) were assessed using FDG-PET, moreover the response disease was assessed using total body CT scan for the evaluation of RECIST criteria 1.1. Results Twelve patients had an objective response to the first line platinum based chemotherapy according RECIST criteria 1.1 and all of them started with a SUVmax at baseline major than 5, indeed the other eight patients, non-responders to chemotherapy, had a SUVmax at baseline minor than 5. Conclusions It is important to define the chemosensitivity of advanced TETs early. Combining bio-pathological parameters with the metabolism at baseline assessed with FDG-PET can help the physician to early predict the probability of obtaining a disease response to first line platinum based chemotherapy. The SUVmax cut off of 5 at 18FDG-PET/CT performed at baseline treatment might be a new parameter for choosing the most powerful first line of chemotherapy. Given these results, further prospective studies are needed to establish a new first line therapy in advanced TETs with a low SUVmax at baseline, non-responders to conventional chemotherapy.

  13. F18 Fluoromisonidazole for Imaging Tumor Hypoxia: Imaging the Microenvironment for Personalized Cancer Therapy

    PubMed Central

    Rajendran, JG; Krohn, KA

    2014-01-01

    Hypoxia in solid tumors is one of the seminal mechanisms for developing aggressive trait and treatment resistsance in solid tumors. This evolutionarily conserved biological mechanism along with de-repression of cellular functions in cancer, although resulting in many challenges, provide us with opportunities to use these adversities to our advantage. Our ability to use molecular imaging to characterize therapeutic targets such as hypoxia and apply this information for therapeutic interventions is growing rapidly. Evaluation of hypoxia and its biological ramifications to effectively plan appropriate therapy that can overcome the cure-limiting effects of hypoxia provides an objective means for treatment selection and planning. FMISO PET imaging of tumor hypoxia continues to be the lead radiopharmaceutical for the evaluation, prognostication and quantification of hypoxia, one of the key elements of the tumor microenvironment. FMISO is less confounded by blood flow and, although the images have less contrast than FDG PET, its uptake after 2 hours is an accurate reflection of inadequate regional Po2 at the time of radiopharmaceutical administration. By virtue of extensive clinical utilization, FMISO remains the lead candidate for imaging and quantifying hypoxia. The past decade has seen significant technological advances in investigating hypoxia imaging in radiation treatment planning and in providing us with the ability to individualize radiation delivery and target volume coverage. The presence of widespread hypoxia in the tumor can be effectively targeted with a systemic hypoxic cell cytotoxin or other agents that are more effective with diminished PO2, either alone or in combination. Molecular imaging in general and hypoxia imaging in particular will likely become an important in vivo imaging biomarker of the future, complementing the traditional direct tissue sampling methods by providing a snap shot of a primary tumor and metastatic disease and in following

  14. Spatial-Temporal [{sup 18}F]FDG-PET Features for Predicting Pathologic Response of Esophageal Cancer to Neoadjuvant Chemoradiation Therapy

    SciTech Connect

    Tan, Shan; Kligerman, Seth; Chen, Wengen; Lu, Minh; Kim, Grace; Feigenberg, Steven; D'Souza, Warren D.; Suntharalingam, Mohan; Lu, Wei

    2013-04-01

    Purpose: To extract and study comprehensive spatial-temporal {sup 18}F-labeled fluorodeoxyglucose ([{sup 18}F]FDG) positron emission tomography (PET) features for the prediction of pathologic tumor response to neoadjuvant chemoradiation therapy (CRT) in esophageal cancer. Methods and Materials: Twenty patients with esophageal cancer were treated with trimodal therapy (CRT plus surgery) and underwent [{sup 18}F]FDG-PET/CT scans both before (pre-CRT) and after (post-CRT) CRT. The 2 scans were rigidly registered. A tumor volume was semiautomatically delineated using a threshold standardized uptake value (SUV) of ≥2.5, followed by manual editing. Comprehensive features were extracted to characterize SUV intensity distribution, spatial patterns (texture), tumor geometry, and associated changes resulting from CRT. The usefulness of each feature in predicting pathologic tumor response to CRT was evaluated using the area under the receiver operating characteristic curve (AUC) value. Results: The best traditional response measure was decline in maximum SUV (SUV{sub max}; AUC, 0.76). Two new intensity features, decline in mean SUV (SUV{sub mean}) and skewness, and 3 texture features (inertia, correlation, and cluster prominence) were found to be significant predictors with AUC values ≥0.76. According to these features, a tumor was more likely to be a responder when the SUV{sub mean} decline was larger, when there were relatively fewer voxels with higher SUV values pre-CRT, or when [{sup 18}F]FDG uptake post-CRT was relatively homogeneous. All of the most accurate predictive features were extracted from the entire tumor rather than from the most active part of the tumor. For SUV intensity features and tumor size features, changes were more predictive than pre- or post-CRT assessment alone. Conclusion: Spatial-temporal [{sup 18}F]FDG-PET features were found to be useful predictors of pathologic tumor response to neoadjuvant CRT in esophageal cancer.

  15. SU-E-J-254: Evaluating the Role of Mid-Treatment and Post-Treatment FDG-PET/CT in Predicting Progression-Free Survival and Distant Metastasis of Anal Cancer Patients Treated with Chemoradiotherapy

    SciTech Connect

    Zhang, H; Wang, J; Chuong, M; D’Souza, W; Choi, W; Lu, W; Latifi, K; Hoffe, S; Moros, E; Saeed, Nadia; Tan, S; Shridhar, R

    2015-06-15

    Purpose: To evaluate the role of mid-treatment and post-treatment FDG-PET/CT in predicting progression-free survival (PFS) and distant metastasis (DM) of anal cancer patients treated with chemoradiotherapy (CRT). Methods: 17 anal cancer patients treated with CRT were retrospectively studied. The median prescription dose was 56 Gy (range, 50–62.5 Gy). All patients underwent FDG-PET/CT scans before and after CRT. 16 of the 17 patients had an additional FDG-PET/CT image at 3–5 weeks into the treatment (denoted as mid-treatment FDG-PET/CT). 750 features were extracted from these three sets of scans, which included both traditional PET/CT measures (SUVmax, SUVpeak, tumor diameters, etc.) and spatialtemporal PET/CT features (comprehensively quantify a tumor’s FDG uptake intensity and distribution, spatial variation (texture), geometric property and their temporal changes relative to baseline). 26 clinical parameters (age, gender, TNM stage, histology, GTV dose, etc.) were also analyzed. Advanced analytics including methods to select an optimal set of predictors and a model selection engine, which identifies the most accurate machine learning algorithm for predictive analysis was developed. Results: Comparing baseline + mid-treatment PET/CT set to baseline + posttreatment PET/CT set, 14 predictors were selected from each feature group. Same three clinical parameters (tumor size, T stage and whether 5-FU was held during any cycle of chemotherapy) and two traditional measures (pre- CRT SUVmin and SUVmedian) were selected by both predictor groups. Different mix of spatial-temporal PET/CT features was selected. Using the 14 predictors and Naive Bayes, mid-treatment PET/CT set achieved 87.5% accuracy (2 PFS patients misclassified, all local recurrence and DM patients correctly classified). Post-treatment PET/CT set achieved 94.0% accuracy (all PFS and DM patients correctly predicted, 1 local recurrence patient misclassified) with logistic regression, neural network or

  16. Preoperative Standardized Uptake Value of Metastatic Lymph Nodes Measured by 18F-FDG PET/CT Improves the Prediction of Prognosis in Gastric Cancer

    PubMed Central

    Song, Bong-Il; Kim, Hae Won; Won, Kyoung Sook; Ryu, Seung Wan; Sohn, Soo Sang; Kang, Yu Na

    2015-01-01

    Abstract This study assessed whether preoperative maximum standardized uptake value (SUVmax) of metastatic lymph nodes (LNs) measured by 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) could improve the prediction of prognosis in gastric cancer. One hundred fifty-one patients with gastric cancer and pathologically confirmed LN involvement who had undergone preoperative 18F-FDG PET/CT prior to curative surgical resection were retrospectively enrolled. To obtain nodal SUVmax, a transaxial image representing the highest 18F-FDG uptake was carefully selected, and a region of interest was manually drawn on the highest 18F-FDG accumulating LN. Conventional prognostic parameters and PET findings (primary tumor and nodal SUVmax) were analyzed for prediction of recurrence-free survival (RFS) and overall survival (OS). Furthermore, prognostic accuracy of survival models was assessed using c-statistics. Of the 151 patients, 38 (25%) experienced recurrence and 34 (23%) died during follow-up (median follow-up, 48 months; range, 5–74 months). Twenty-seven patients (18%) showed positive 18F-FDG nodal uptake (range, 2.0–22.6). In these 27 patients, a receiver-operating characteristic curve demonstrated a nodal SUVmax of 2.8 to be the optimal cutoff for predicting RFS and OS. The univariate and multivariate analyses showed that nodal SUVmax (hazard ratio [HR] = 2.71, P < 0.0001), pathologic N (pN) stage (HR = 2.58, P = 0.0058), and pathologic T (pT) stage (HR = 1.77, P = 0.0191) were independent prognostic factors for RFS. Also, nodal SUVmax (HR = 2.80, P < 0.0001) and pN stage (HR = 2.28, P = 0.0222) were independent prognostic factors for OS. A predictive survival model incorporating conventional risk factors (pT/pN stage) gave a c-statistic of 0.833 for RFS and 0.827 for OS, whereas a model combination of nodal SUVmax with pT/pN stage gave a c-statistic of 0.871 for RFS (P = 0

  17. pO polarography, contrast enhanced color duplex sonography (CDS), [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography: validated methods for the evaluation of therapy-relevant tumor oxygenation or only bricks in the puzzle of tumor hypoxia?

    PubMed Central

    Gagel, Bernd; Piroth, Marc; Pinkawa, Michael; Reinartz, Patrick; Zimny, Michael; Kaiser, Hans J; Stanzel, Sven; Asadpour, Branka; Demirel, Cengiz; Hamacher, Kurt; Coenen, Heinz H; Scholbach, Thomas; Maneschi, Payam; DiMartino, Ercole; Eble, Michael J

    2007-01-01

    Background The present study was conducted to analyze the value of ([18F] fluoromisonidazole (FMISO) and [18F]-2-fluoro-2'-deoxyglucose (FDG) PET as well as color pixel density (CPD) and tumor perfusion (TP) assessed by color duplex sonography (CDS) for determination of therapeutic relevant hypoxia. As a standard for measuring tissue oxygenation in human tumors, the invasive, computerized polarographic needle electrode system (pO2 histography) was used for comparing the different non invasive measurements. Methods Until now a total of 38 Patients with malignancies of the head and neck were examined. Tumor tissue pO2 was measured using a pO2-histograph. The needle electrode was placed CT-controlled in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO2 readings, with values ≤ 2.5, ≤ 5.0 and ≤ 10.0 mmHg, as well as mean and median pO2 were stated. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. FMISO tumor to muscle ratios (FMISOT/M) and tumor to blood ratios (FMISOT/B) were calculated. FDG PET of the lymph node metastases was performed 71 ± 17 min after intravenous administration. To visualize as many vessels as possible by CDS, a contrast enhancer (Levovist®, Schering Corp., Germany) was administered. Color pixel density (CPD) was defined as the ratio of colored to grey pixels in a region of interest. From CDS signals two parameters were extracted: color hue – defining velocity (v) and color area – defining perfused area (A). Signal intensity as a measure of tissue perfusion (TP) was quantified as follows: TP = vmean × Amean. Results In order to investigate the degree of linear association, we calculated the Pearson correlation coefficient. Slight (|r| > 0.4) to moderate (|r| > 0.6) correlation was found between the parameters of pO2 polarography (pO2 readings with values ≤ 2.5, ≤ 5

  18. Lesion regression rate based on RECIST: prediction of treatment outcome in patients with head and neck cancer treated with chemoradiotherapy compared with FDG PET-CT

    PubMed Central

    Matoba, Munetaka; Tuji, Hiroyuki; Shimode, Yuzo; Kondo, Tamaki; Oota, Kiyotaka; Tonami, Hisao

    2015-01-01

    The aim of this study was to evaluate whether the lesion regression rate (ΔLR) based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria could be used for the prediction of treatment outcome in head and neck squamous cell carcinoma (HNSCC) patients treated with chemoradiotherapy (CRT) compared with FDG PET-CT. A total of 33 patients underwent MRI and PET-CT at pretreatment and at 8 weeks after CRT. We assessed the treatment outcome by analyzing the following parameters: the RECIST criteria, ΔLR, the European Organization for Research and Treatment of Cancer (EORTC) criteria, and pretreatment SUVmax of the primary tumor and node. The correlation between the analysis of the parameters and the results of the long-term follow-up of the patients was determined. The RECIST did not significantly correlate with locoregional control (LRC) or survival. The ΔLR was significantly lower for the lesions with locoregional failure (LRF) than for those with LRC. A threshold ΔLR of 48% revealed a sensitivity of 72.7% and specificity of 77.3% for the prediction of LRF. Progression-free survival (PFS) of patients with ΔLR ≥ 48% was significantly better than that of patients with ΔLR < 48% (P = 0.001), but not overall survival. There was a significant correlation between LRC and the EORTC (P = 0.02). The patients who achieved a complete response by the EORTC criteria showed significantly better PFS and overall survival (P = 0.01 and 0.04, respectively). The ΔLR was inferior to FDG PET-CT with respect to the prediction of patient survival; however, it may be useful for selecting patients in need of more aggressive monitoring after CRT. PMID:25829531

  19. Temsirolimus and pegylated liposomal doxorubicin (PLD) combination therapy in breast, endometrial, and ovarian cancer: phase Ib results and prediction of clinical outcome with FDG-PET/CT.

    PubMed

    Boers-Sonderen, Marye J; de Geus-Oei, Lioe-Fee; Desar, Ingrid M E; van der Graaf, Winette T A; Oyen, Wim J G; Ottevanger, Petronella B; van Herpen, Carla M L

    2014-12-01

    Pegylated liposomal doxorubicin (PLD) is active in breast, endometrial, and ovarian cancer. Preclinical data suggest that the combination of PLD with a mammalian target of rapamycin (mTOR) inhibitor has an additive effect. The safety and recommended phase two dose (RPTD) of temsirolimus in combination with PLD were assessed. (18) F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT was performed for early response monitoring. Nineteen patients with advanced breast, endometrial, and ovarian cancer were treated with increasing doses of temsirolimus (10, 15, or 20 mg once weekly) and PLD (30 or 40 mg/m(2) once every 4 weeks). PLD was initiated 2 weeks after start of temsirolimus. FDG-PET/CT was performed at baseline, after 2 and 6 weeks. Standardized uptake values (SUV), metabolic volume, and total lesion glycolysis (TLG, SUV × metabolic volume) were calculated. The RPTD was 15 mg temsirolimus and 40 mg/m(2) PLD. Dose-limiting toxicities (DLT) were thrombocytopenia grade 3 with nose bleeding and skin toxicity grade 3. Most frequent treatment-related toxicities were nausea, fatigue, mucositis, and skin toxicity. Changes in TLG after 2 weeks predicted partial response (PR) after 10 weeks (p = 0.037). A rise in SUV between the second and sixth week predicted progression (PD) (p = 0.034) and was associated with worse progression free survival (PFS) (HR 1.068; p = 0.013). The RPTD was established at 15 mg temsirolimus weekly and PLD 40 mg/m(2) once every 4 weeks and the combination was safe. Early response evaluation with FDG-PET/CT may predict subsequent radiological PR and PD. This trial is registered under number NCT0098263. PMID:24577626

  20. Pet Health

    MedlinePlus

    ... Before getting a pet, think carefully about which animal is best for your family. What is each ... Does anyone have pet allergies? What type of animal suits your lifestyle and budget? Once you own ...

  1. PiB-PET Imaging-Based Serum Proteome Profiles Predict Mild Cognitive Impairment and Alzheimer's Disease.

    PubMed

    Kang, Seokjo; Jeong, Hyobin; Baek, Je-Hyun; Lee, Seung-Jin; Han, Sun-Ho; Cho, Hyun Jin; Kim, Hee; Hong, Hyun Seok; Kim, Young Ho; Yi, Eugene C; Seo, Sang Won; Na, Duk L; Hwang, Daehee; Mook-Jung, Inhee

    2016-07-01

    Development of a simple, non-invasive early diagnosis platform of Alzheimer's disease (AD) using blood is urgently required. Recently, PiB-PET imaging has been shown to be powerful to quantify amyloid-β plaque loads leading to pathophysiological alterations in AD brains. Thus, there has been a need for serum biomarkers reflecting PiB-PET imaging data as an early diagnosis platform of AD. Here, using LC-MS/MS analysis coupled with isobaric tagging, we performed comprehensive proteome profiling of serum samples from cognitively normal controls, mild cognitive impairment (MCI), and AD patients, who were selected using PiB-PET imaging. Comparative analysis of the proteomes revealed 79 and 72 differentially expressed proteins in MCI and AD, respectively, compared to controls. Integrated analysis of these proteins with genomic and proteomic data of AD brain tissues, together with network analysis, identified three biomarker candidates representing the altered proteolysis-related process in MCI or AD: proprotein convertase subtilisin/kexin type 9 (PCSK9), coagulation factor XIII, A1 polypeptide (F13A1), and dermcidin (DCD). In independent serum samples of MCI and AD, we confirmed the elevation of the candidates using western blotting and ELISA. Our results suggest that these biomarker candidates can serve as a potential non-invasive early diagnosis platform reflecting PiB-PET imaging for MCI and AD. PMID:27392853

  2. Reliability of proton-nuclear interaction cross section data to predict proton-induced PET images in proton therapy

    PubMed Central

    España, S; Zhu, X; Daartz, J; El Fakhri, G; Bortfeld, T

    2011-01-01

    In-vivo PET range verification relies on the comparison of measured and simulated activity distributions. The accuracy of the simulated distribution depends on the accuracy of the Monte Carlo code, which is in turn dependent on the accuracy of the available cross sections data for β+ isotope production. We have explored different cross section data available in the literature for the main reaction channels (16O(p,pn)15O, 12C(p,pn)11C and 16O(p,3p3n)11C) contributing to the production of β+ isotopes by proton beams in patients. Available experimental and theoretical values were implemented in the simulation and compared with measured PET images obtained with a high-resolution PET scanner. Each reaction channel was studied independently. A phantom with three different materials was built, two of them with high carbon or oxygen concentration and a third one with average soft tissue composition. Monoenergetic and SOBP field irradiations of the phantom were accomplished and measured PET images were compared with simulation results. Different cross section values for the tissue-equivalent material lead to range differences below 1 mm when a 5 min scan time was employed and close to 5 mm differences for a 30 min scan time with 15 min delay between irradiation and scan (a typical off-line protocol). The results presented here emphasize the need of more accurate measurement of the cross section values of the reaction channels contributing to the production of PET isotopes by proton beams before this in-vivo range verification method can achieve mm accuracy. PMID:21464534

  3. Tumor hypoxia: a new PET imaging biomarker in clinical oncology.

    PubMed

    Tamaki, Nagara; Hirata, Kenji

    2016-08-01

    Tumor hypoxia is associated with tumor progression and resistance to various treatments. Noninvasive imaging using positron emission tomography (PET) and F-18-labeled fluoromisonidazole (FMISO) was recently introduced in order to define and quantify tumor hypoxia. The FMISO uptake was closely correlated with pimonidazole immunohistochemistry and hypoxia-inducible factor 1 expression in basic studies. Tumor hypoxia in head and neck cancers and other tumors in a clinical setting may also indicate resistance to radiation and/or chemotherapy. Hypoxic imaging may thus play a new and important role for suitable radiation planning, including dose escalation and dose reduction based on the image findings. Such radiation-dose painting based on the findings of hypoxia may require high-performance PET imaging to provide high target-to-background ratio images and an optimal quantitative parameter to define the hypoxic region. A multicenter prospective study using data from a large number of patients is also warranted to test the clinical value of hypoxic imaging. PMID:26577447

  4. Metabolic Response on Post-therapy FDG-PET Predicts Patterns of Failure After Radiotherapy for Cervical Cancer

    SciTech Connect

    Schwarz, Julie K.; Siegel, Barry A.; Dehdashti, Farrokh; Grigsby, Perry W.

    2012-05-01

    Purpose: To determine the patterns of failure in patients with cervical cancer treated with definitive radiotherapy and evaluated for metabolic response with early posttherapy {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET). Methods and Materials: The records of 238 patients with cervical cancer were reviewed. All patients were treated with a combination of external radiotherapy and intracavitary brachytherapy. Two hundred and nineteen patients (92%) received concurrent chemotherapy. All patients underwent pretreatment FDG-PET, and posttherapy FDG-PET was performed within 8-16 weeks of the completion of radiotherapy. Posttherapy FDG-PET results were categorized as complete metabolic response (CMR), partial metabolic response (PMR), and progressive disease (PD). Failure patterns were categorized as none, isolated local failure (central pelvis {+-} pelvic lymph nodes), distant failure, or combined local plus distant failure. Results: Of the 91 patients (38%) who had a recurrence, 22 had isolated local failures, and 69 had distant failures (49 distant failures and 20 combined local plus distant failures). Of the 173 patients with a CMR, 40 (23%) experienced treatment failure. All 25 patients with PD experienced treatment failure, which was distant in 24 patients (96%). Among the 40 patients with PMR, no failure has been observed for 14 patients (35%). Of the 26 failures within the PMR group, 15 (58%) were limited to the pelvis. Differences in the patterns of failure between the three groups (CMR, PMR, PD) were statistically significant (chi-square test; p < 0.0001). Conclusions: The majority of failures after definitive radiotherapy for cervical cancer include distant failures, even in the setting of concurrent chemotherapy. PMR within the cervix or lymph nodes is more commonly associated with isolated local recurrence.

  5. The preclinical study of predicting radiosensitivity in human nasopharyngeal carcinoma xenografts by 18F-ML-10 animal- PET/CT imaging

    PubMed Central

    Wang, Siyang; Zheng, Yujia; Wang, Mingwei; Gu, Bingxin; Zhang, Jianping; Zhang, Yongping; Zhang, Yingjian

    2016-01-01

    Previous studies have reported that the radiosensitivity is associated with apoptosis. Hereby, we aimed to investigate the value of 18F-ML-10 PET/CT, which selectively targeted cells undergoing apoptosis, in predicting radiosensitivity of human nasopharyngeal carcinoma (NPC) xenografts. We used CNE1 (highly differentiated) and CNE2 (poorly differentiated) NPC cell lines to construct tumor models, which had very different radiosensitivities. After irradiation, the volumes of CNE2 tumors decreased significantly while those of CNE1 tumors increased. In 18F-ML-10 imaging, the values of tumor/muscle (T/M) between CNE1 and CNE2 mice were statistically different at both 24 h and 48 h after irradiation. Besides, ΔT/M1-0 and ΔT/M2-0 of CNE2 mice were higher than those of CNE1 mice, demonstrating obvious discrepancy. Furthermore, we observed obvious changes of radioactive distribution in CNE2 group. On the contrary, T/M of 18F-FDG in irradiation group revealed no obvious change in both CNE1 and CNE2 groups. In conclusion, 18F-ML-10 animal PET/CT showed its potential to predict radiosensitivity in NPC. PMID:26942701

  6. Radiopharmaceuticals in Preclinical and Clinical Development for Monitoring of Therapy with PET

    PubMed Central

    Dunphy, Mark PS.; Lewis, Jason S.

    2010-01-01

    This review article discusses PET agents, other than 18F-FDG, with the potential to monitor the response to therapy before, during, or after therapeutic intervention. This review deals primarily with non–18F-FDG PET tracers that are in the final stages of preclinical development or in the early stages of clinical application for monitoring the therapeutic response. Four sections related to the nature of the tracers are included: radiotracers of DNA synthesis, such as the 2 most promising agents, the thymidine analogs 3′-18F-fluoro-3′-deoxythymidine and 18F-1-(2′-deoxy-2′-fluoro-β-d-arabinofuranosyl)thymine; agents for PET imaging of hypoxia within tumors, such as 60/62/64Cu-labeled diacetyl-bis(N4-methylthiosemicarbazone) and 18F-fluoromisonidazole; amino acids for PET imaging, including the most popular such agent, l-[methyl-11C]methionine; and agents for the imaging of tumor expression of androgen and estrogen receptors, such as 16β-18F-fluoro-5α-dihydrotestosterone and 16α-18F-fluoro-17β-estradiol, respectively. PMID:19380404

  7. Preoperative Prediction of Cervical Lymph Node Metastasis Using Primary Tumor SUVmax on 18F-FDG PET/CT in Patients with Papillary Thyroid Carcinoma

    PubMed Central

    Jung, Ji-hoon; Kim, Choon-Young; Son, Seung Hyun; Kim, Do-Hoon; Jeong, Shin Young; Lee, Sang-Woo; Lee, Jaetae; Ahn, Byeong-Cheol

    2015-01-01

    Objectives The aim of the current study was to evaluate the value of preoperative 18F-FDG (FDG) PET/CT in predicting cervical lymph node (LN) metastasis in patients with papillary thyroid carcinoma (PTC). Methods One hundred and ninety-three newly diagnosed PTC patients (M: F = 25:168, age = 46.8 ± 12.2) who had undergone pretreatment FDG PET/CT and had neck node dissection were included in this study. The FDG avidity of the primary tumor and the SUVmax of the primary tumor (pSUVmax) were analyzed for prediction of LN metastasis. Detectability by ultrasonography (US) and FDG PET/CT for cervical LN metastasis were also assessed and compared with the pSUVmax. Results The FDG avidity of the primary tumor was identified in 118 patients (FDG avid group: 61.0%, M: F = 16:102, age 47.0 ± 12.7 years) and pSUVmax ranged from 1.3 to 35.6 (median 4.6) in the FDG avid group. The tumor size in the FDG avid group was bigger and there was a higher incidence of LN metastasis compared to the FDG non-avid group (0.93 vs. 0.59 cm, p <0.001 and 49.2 vs. 33.3%, p <0.05). In the FDG avid group, patients with LN metastasis had higher pSUVmax than patients without LN metastasis (8.7 ± 8.3 vs. 5.7 ± 5.1, p <0.001). The incidence of central LN metastasis in patients with a pSUVmax >4.6 was 54%; however, the detectability of central LN metastasis by US and FDG PET/CT were 10.3% and 3.6%, respectively. Conclusion A high FDG avidity of the primary tumor was related to LN metastasis in PTC patients. Therefore, patients with a high pSUVmax should be cautiously assessed for LN metastasis and might need a more comprehensive surgical approach. PMID:26636824

  8. Metabolic Tumour Burden Measured by 18F-FDG PET/CT Predicts Malignant Transformation in Patients with Neurofibromatosis Type-1

    PubMed Central

    Van Der Gucht, Axel; Zehou, Ouidad; Djelbani-Ahmed, Soraya; Valeyrie-Allanore, Laurence; Ortonne, Nicolas; Brugières, Pierre; Wolkenstein, Pierre; Luciani, Alain; Rahmouni, Alain; Sbidian, Emilie; Itti, Emmanuel

    2016-01-01

    Background To investigate the diagnostic and prognostic performances of 18F-FDG PET/CT measures of metabolic tumour burden in patients with neurofibromatosis type-1 (NF1), suspect of malignant transformation. Methods This retrospective study included 49 patients (15–60 years old, 30 women) with a diagnosis of NF1, followed in our Reference Centre for Rare Neuromuscular Diseases, who presented clinical signs of tumour progression (pain, neurological deficit, tumour growth). Quantitative metabolic parameters were measured on 149 tumoral targets, using semi-automatic software and the best cut off values to predict transformation was assessed by Receiver Operating Characteristics (ROC) analysis. Prognostic value of PET/CT metabolic parameters was assessed by Kaplan-Meier estimates of overall survival. Results Lesions were histologically documented in 40 patients: a sarcomatous transformation was found in 16, a dysplastic neurofibroma (NF) in 7, and a benign NF in 17; in the remaining 9 patients, a minimal follow-up of 12 mo (median 59 mo) confirmed the absence of transformation. The optimal cut off values for detection of malignant transformation were, in decreasing order of area under the ROC curves, a tumour-to-liver (T/L) ratio >2.5, SUVmax > 4.5, total lesion glycolysis (TLG) > 377, total metabolic tumour volume (TMTV) > 88 cm3, and heterogeneity index (HIsuv) > 1.69. The best prognostic marker was the TLG: the 4-y estimates of survival were 97% [95% CI, 90% - 100%] in patients with TLG ≤ 377 vs. 27% [95% CI, 5% - 49%] in patients with TLG > 377 (P < 0.0001; χ2 27.85; hazard ratio 13.27 [95% CI, 3.72–47.35]). T/L ratio, SUVmax and TMTV demonstrated slightly lower performance to predict survival, with χ2 ranging 14.41–19.12. The HIsuv index was not predictive of survival. Conclusion Our study demonstrates that TLG and TMTV, as PET/CT measures of metabolic tumour burden, may be used clinically to identify sarcomatous transformation in patients with NF1 and

  9. (18)F-FDG PET/CT in the early prediction of pathological response in aggressive subtypes of breast cancer: review of the literature and recommendations for use in clinical trials.

    PubMed

    Groheux, David; Mankoff, David; Espié, Marc; Hindié, Elif

    2016-05-01

    Early assessment of response to neoadjuvant chemotherapy (NAC) might be helpful in avoiding the toxicity of ineffective chemotherapy and allowing refinement of treatment. We conducted a review of the literature regarding the applicability of (18)F-FDG PET/CT to the prediction of an early pathological response in different subgroups of breast cancer. Clinical research in this field has intensified in the last few years. Early studies by various groups have shown the potential of (18)F-FDG PET/CT in the early assessment of response to NAC. However, interim PET/CT in breast cancer has not yet gained wide acceptance compared to its use in other settings such as lymphomas. This is in part due to a lack of consensus that early evaluation of response can be used to direct change in therapy in the neoadjuvant breast cancer setting, and only limited data showing that response-adaptive therapy leads to improved outcomes. However, one major element that has hampered the use of (18)F-FDG PET/CT in directing neoadjuvant therapy is its evaluation in populations with mixed subtypes of breast cancer. However, major improvements have occurred in recent years. Pilot studies have highlighted the need for considering breast cancer subtype and the type of treatment, and have offered criteria for the use of PET/CT for the early prediction of response in specific settings. (18)F-FDG PET/CT has considerable potential for the early prediction of pathological complete response to NAC in aggressive subtypes such as triple-negative or HER2-positive breast cancers. The results of a multicentre trial that used early metabolic response on (18)F-FDG PET/CT as a means to select poor responders to adapt neoadjuvant treatment have recently been published. Other trials are ongoing or being planned. PMID:26758726

  10. Prediction of Response to Neoadjuvant Radiotherapy in Patients With Locally Advanced Rectal Cancer by Means of Sequential 18FDG-PET

    SciTech Connect

    Everaert, Hendrik; Hoorens, Anne; Vanhove, Christian; Sermeus, Alexandra; Ceulemans, Gaetane; Engels, Benedikt; Vermeersch, Marieke; Verellen, Dirk; Urbain, Daniel; Storme, Guy; De Ridder, Mark

    2011-05-01

    Purpose: Morphologic imaging techniques perform poorly in assessing the response to preoperative radiotherapy (RT), mainly because of desmoplastic reactions. The aim of this study was to investigate the potential of sequential 18-fluoro-2-deoxy-D-glucose (18FDG-PET) in assessing the response of rectal cancer to neoadjuvant RT and to determine which parameters can be used as surrogate markers for histopathologic response. Methods and Materials: 18FDG-PET scans were acquired before and during the 5th week after the end of RT. Tracer uptake was assessed semiquantitatively using standardized uptake values (SUV). The percentage differences (%{Delta}) between pre- and post-RT scans in SUV{sub max}, SUV{sub mean}, metabolic volume (MV), and total glycolytic volume (tGV) were calculated. Results: Forty-five consecutive patients with histologically confirmed rectal adenocarcinoma were enrolled. After neoadjuvant RT, 20 of the 45 patients were classified as histopathologic responders and 25 as non-responders. Intense 18F-FDG uptake was seen in all tumors before neoadjuvant RT (average SUV{sub max} 12.9 {+-} 6.0). When patients were classified as histologic responders and nonresponders, significant differences in %{Delta}SUV{sub max} (55.8% vs. 37.4%, p = 0.023) and %{Delta}SUV{sub mean} (40.1% vs. 21.0%, p = 0.001) were observed between the two groups. For %{Delta}MV and %{Delta}tGV, decreases were more prominent in responders but were not significantly different from those in nonresponders. As demonstrated by receiver operating characteristic analysis, %{Delta}SUV{sub mean} was a more powerful discriminator than was %{Delta}SUV{sub max}. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for optimal threshold of %{Delta}SUV{sub mean} (24.5%) were 80%, 72%, 76%, 70%, and 82% respectively. Conclusion: Sequential 18FDG-PET allows assessment of the response to preoperative RT. Both %{Delta}SUV{sub mean} and %{Delta}SUV{sub max

  11. FDG-PET/CT Imaging Predicts Histopathologic Treatment Responses after Neoadjuvant Therapy in Adult Primary Bone Sarcomas

    DOE PAGESBeta

    Benz, Matthias R.; Czernin, Johannes; Tap, William D.; Eckardt, Jeffrey J.; Seeger, Leanne L.; Allen-Auerbach, Martin S.; Dry, Sarah M.; Phelps, Michael E.; Weber, Wolfgang A.; Eilber, Fritz C.

    2010-01-01

    Purpose . Tmore » he aim of this study was to prospectively evaluate whether FDG-PET allows an accurate assessment of histopathologic response to neoadjuvant treatment in adult patients with primary bone sarcomas. Methods . Twelve consecutive patients with resectable, primary high grade bone sarcomas were enrolled prospectively. FDG-PET/CT imaging was performed prior to the initiation and after completion of neoadjuvant treatment. Imaging findings were correlated with histopathologic response. Results . Histopathologic responders showed significantly more pronounced decreases in tumor FDG-SUVmax from baseline to late follow up than non-responders ( 64 ± 19 % versus 29 ± 30 %, resp.; P = .03 ). Using a 60% decrease in tumor FDG-uptake as a threshold for metabolic response correctly classified 3 of 4 histopathologic responders and 7 of 8 histopathologic non-responders as metabolic responders and non-responders, respectively (sensitivity, 75%; specificity, 88%). Conclusion . These results suggest that changes in FDG-SUVmax at the end of neoadjuvant treatment can identify histopathologic responders and non-responders in adult primary bone sarcoma patients.« less

  12. PET scan

    MedlinePlus

    You may feel a sharp sting when the needle with the tracer is placed into your vein. A PET scan causes no pain. The table may be ... The amount of radiation used in a PET scan is about the same amount as used in most CT scans. These scans use ...

  13. Lung PET scan

    MedlinePlus

    ... emission tomography; PET - chest; PET - lung; PET - tumor imaging ... Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015: ...

  14. Prediction of Large Joint Destruction in Patients With Rheumatoid Arthritis Using 18F-FDG PET/CT and Disease Activity Score

    PubMed Central

    Suto, Takahito; Okamura, Koichi; Yonemoto, Yukio; Okura, Chisa; Tsushima, Yoshito; Takagishi, Kenji

    2016-01-01

    Abstract The assessments of joint damage in patients with rheumatoid arthritis (RA) are mainly restricted to small joints in the hands and feet. However, the development of arthritis in RA patients often involves the large joints, such as the shoulder, elbow, hip, knee, and ankle. Few studies have been reported regarding the degree of large joint destruction in RA patients. 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) visualizes the disease activity in large joints affected by RA. In this study, the associations between destruction of the large joints and the findings of FDG-PET/CT as well as laboratory parameters were investigated, and factors associated with large joint destruction after the administration of biological therapy were identified in RA patients. A total of 264 large joints in 23 RA patients (6 men and 17 women; mean age of 66.9 ± 7.9 years) were assessed in this study. FDG-PET/CT was performed at baseline and 6 months after the initiation of biological therapy. The extent of FDG uptake in large joints (shoulder, elbow, wrist, hip, knee, and ankle) was analyzed using the maximum standardized uptake value (SUVmax). Radiographs of the 12 large joints per patient obtained at baseline and after 2 years were assessed according to Larsen's method. A logistic regression analysis was performed to determine the factors most significantly contributing to the progression of joint destruction within 2 years. Radiographic progression of joint destruction was detected in 33 joints. The SUVmax at baseline and 6 months, and the disease activity score (DAS) 28-erythrocyte sedimentation rate (ESR) at 6, 12, and 24 months were significantly higher in the group with progressive joint destruction. The SUVmax at baseline and DAS28-ESR at 6 months were found to be factors associated with joint destruction at 2 years (P < 0.05). The FDG uptake in the joints with destruction was higher than that observed in the

  15. SU-E-J-258: Prediction of Cervical Cancer Treatment Response Using Radiomics Features Based On F18-FDG Uptake in PET Images

    SciTech Connect

    Altazi, B; Fernandez, D; Zhang, G; Biagioli, M; Moros, E; Moffitt, H. Lee

    2015-06-15

    Purpose: Radiomics have shown potential for predicting treatment outcomes in several body sites. This study investigated the correlation between PET Radiomics features and treatment response of cervical cancer outcomes. Methods: our dataset consisted of a cohort of 79 patients diagnosed with cervical cancer, FIGO stage IB-IVA, age range 25–86 years, (median age at diagnosis: 50 years) all treated between: 2009–14 with external beam radiation therapy to a dose range between: 45–50.4 Gy (median= 45 Gy), concurrent cisplatin chemotherapy and MRI-based brachytherapy to a dose of 20–30 Gy (median= 28 Gy). Metabolic Tumor Volume (MTV) in patient’s primary site was delineated on pretreatment PET/CT by two board certified Radiation Oncologists. The features extracted from each patient’s volume were: 26 Co-occurrence matrix (COM) Feature, 11 Run-Length Matrix (RLM), 11 Gray Level Size Zone Matrix (GLSZM) and 33 Intensity-based features (IBF). The treatment outcome was divided based on the last follow up status into three classes: No Evidence of Disease (NED), Alive with Disease (AWD) and Dead of Disease (DOD). The ability for the radiomics features to differentiate between the 3 treatments outcome categories were assessed by One-Way ANOVA test with p-value < 0.05 was to be statistically significant. The results from the analysis were compared with the ones obtained previously for standard Uptake Value (SUV). Results: Based on patients last clinical follow-up; 52 showed NED, 17 AWD and 10 DOD. Radiomics Features were able to classify the patients based on their treatment response. A parallel analysis was done for SUV measurements for comparison. Conclusion: Radiomics features were able to differentiate between the three different classes of treatment outcomes. However, most of the features were only able to differentiate between NED and DOD class. Also, The ability or radiomics features to differentiate types of response were more significant than SUV.

  16. Predictive efficacy of (11)C-PD153035 PET imaging for EGFR-tyrosine kinase inhibitor sensitivity in non-small cell lung cancer patients.

    PubMed

    Dai, Dong; Li, Xiao-Feng; Wang, Jian; Liu, Jian-Jing; Zhu, Yan-Jia; Zhang, Ying; Wang, Qi; Xu, Wen-Gui

    2016-02-15

    To determine the correlation of (11)C-PD153035 uptake with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) sensitivity and phosphorylated EGFR (pEGFR) expression in non-small cell lung cancer (NSCLC) cell lines with different EGFR-TKI sensitivities and in their corresponding xenografts. Four human NSCLC cell lines (HCC827, PC9, A549, and H1975) in the logarithmic phase were co-incubated with (11)C-PD153035 to analyze the correlation of (11)C-PD153035 uptake with EGFR-TKI sensitivity, and EGFR/pEGFR expression. Nude mice xenograft models bearing the four NSCLCs were prepared. (11)C-PD153035 positron-emission tomography (PET)-computed tomography (CT) was used to image the xenografts and observe radioactive uptakes. Correlation of the in vivo uptakes with EGFR-TKI sensitivity, and EGFR/pEGFR expression was analyzed. HCC827 and PC9 cells, which were highly sensitive to EGFR-TKIs, exhibited higher (11)C-PD153035 uptakes than the other cells. A549 cells, which were moderately sensitive to EGFR-TKIs, showed higher uptake than the EGFR-TKI-resistant H1975 cells, which showed little or no uptake. Radioactive uptakes were positively correlated with pEGFR expression in all cells. PET-CT showed that radioactivity was highest in HCC827 xenografts. The radioactivity in PC9 xenografts was higher than that in A549 and H1975 xenografts. Tumor vs. non-tumor tissue ratio values were positively correlated with pEGFR expression in HCC827 and PC9 xenografts, but not in A549 and H1975 xenografts. In conclusion, (11)C-PD153035 can serve as an EGFR imaging agent in vitro and in vivo, and predicts sensitivity to EGFR-TKIs. This will provide an experimental basis for clinical applications of (11)C-PD153035 and individualized NSCLC therapy. PMID:26334931

  17. Influence of Software Tool and Methodological Aspects of Total Metabolic Tumor Volume Calculation on Baseline [18F]FDG PET to Predict Survival in Hodgkin Lymphoma

    PubMed Central

    Kanoun, Salim; Tal, Ilan; Berriolo-Riedinger, Alina; Rossi, Cédric; Riedinger, Jean-Marc; Vrigneaud, Jean-Marc; Legrand, Louis; Humbert, Olivier; Casasnovas, Olivier; Brunotte, François; Cochet, Alexandre

    2015-01-01

    Aim To investigate the respective influence of software tool and total metabolic tumor volume (TMTV0) calculation method on prognostic stratification of baseline 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ([18F]FDG-PET) in newly diagnosed Hodgkin lymphoma (HL). Methods 59 patients with newly diagnosed HL were retrospectively included. [18F]FDG-PET was performed before any treatment. Four sets of TMTV0 were calculated with Beth Israel (BI) software: based on an absolute threshold selecting voxel with standardized uptake value (SUV) >2.5 (TMTV02.5), applying a per-lesion threshold of 41% of the SUVmax (TMTV041) and using a per-patient adapted threshold based on SUVmax of the liver (>125% and >140% of SUVmax of the liver background; TMTV0125 and TMTV0140). TMTV041 was also determined with commercial software for comparison of software tools. ROC curves were used to determine the optimal threshold for each TMTV0 to predict treatment failure. Results Median follow-up was 39 months. There was an excellent correlation between TMTV041 determined with BI and with the commercial software (r = 0.96, p<0.0001). The median TMTV0 value for TMTV041, TMTV02.5, TMTV0125 and TMTV0140 were respectively 160 (used as reference), 210 ([28;154] p = 0.005), 183 ([-4;114] p = 0.06) and 143ml ([-58;64] p = 0.9). The respective optimal TMTV0 threshold and area under curve (AUC) for prediction of progression free survival (PFS) were respectively: 313ml and 0.70, 432ml and 0.68, 450ml and 0.68, 330ml and 0.68. There was no significant difference between ROC curves. High TMTV0 value was predictive of poor PFS in all methodologies: 4-years PFS was 83% vs 42% (p = 0.006) for TMTV02.5, 83% vs 41% (p = 0.003) for TMTV041, 85% vs 40% (p<0.001) for TMTV0125 and 83% vs 42% (p = 0.004) for TMTV0140. Conclusion In newly diagnosed HL, baseline metabolic tumor volume values were significantly influenced by the choice of the method used for determination of volume. However, no significant

  18. Pretreatment regional brain glucose uptake in the midbrain on PET may predict remission from a major depressive episode after three months of treatment.

    PubMed

    Milak, Matthew S; Parsey, Ramin V; Lee, Leilani; Oquendo, Maria A; Olvet, Doreen M; Eipper, Francoise; Malone, Kevin; Mann, J John

    2009-07-15

    In order to test the hypotheses that pretreatment metabolic activity in the midbrain and the rostral anterior cingulate may predict remission in response to medications enhancing monoaminergic transmission, we compared relative regional cerebral metabolic rate of glucose (rCMRglu) using positron emission tomography (PET) in medication-free patients with major depression who remitted after 3 months of monoaminergic medication, with non-remitters on the same treatment. [(18)F]-FDG PET was conducted in a group of 33 drug-free DSM-IV major depression subjects prior to antidepressant treatment. Patients were prescribed paroxetine initially (61%) unless they had failed paroxetine previously. Treatment was then managed by the subjects' own physician with 91% receiving a selective serotonin reuptake inhibitor and 78% another non-selective monoamine reuptake inhibitor during the 3 months of treatment. Voxel-based parametric brain maps of remitters were compared with maps of non-remitters using SPM2. Remission was defined as a >50% decrease in and a final score of predicts remission in response to 3 months of antidepressant treatment, despite no clinical differences at baseline and no difference in treatment intensity. Brain imaging is a

  19. 18F-fluorodeoxyglucose (FDG) PET/CT after two cycles of neoadjuvant therapy may predict response in HER2-negative, but not in HER2-positive breast cancer

    PubMed Central

    Mo, Miao; Bao, Xiao; Zhang, Yingjian; Liu, Guangyu; Zhang, Jun; Geng, Daoying

    2015-01-01

    The aim of this prospective study was to assess the ability of 18F-fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography (PET/CT) scanning to predict pathological complete response (pCR) in breast cancer, and to investigate whether timing of the scan and trastuzumab treatment influence the accuracy of pCR prediction in human epidermal growth factor receptor 2 (HER2) positive breast cancer patients. We treated 81 locally advanced breast cancer patients with four cycles of neoadjuvant chemotherapy (NAC). HER2-negative breast cancer patients received NAC alone, while HER2-positive breast cancer patients received NAC plus trastuzumab. 18FDG PET/CT scans were scheduled at baseline and after the second cycle of NAC. Axillary lymph node (ALN) dissection was performed after the last cycle of neoadjuvant therapy. Relative changes in standardized uptake values (SUV) between the two PET/CT scans (ΔSUV) in primary tumors and ALN metastases were calculated. There were 75 patients with 150 PET/CT scans in the final analysis, including 41 HER2-negative and 34 HER2-positive cases. In the HER2-negative group, the ΔSUV predicted overall and ALN pCR; the receiver operating characteristics-areas under curve (ROC-AUC) were 0.87 and 0.80 (P = 0.0014 and 0.031, respectively) and the negative predictive values were 94% and 89% respectively. However, in the HER2-positive group, ΔSUV could predict neither overall nor ALN pCR; the ROC-AUCs were only 0.56 and 0.53, with P = 0.53 and 0.84, respectively. Hence, the ΔSUV after two cycles of neoadjuvant therapy could predict pCR in HER2-negative patients treated with NAC alone, but not in HER2-positive patients treated with NAC plus trastuzumab. PMID:26336821

  20. Positron Emission Tomography (PET)

    SciTech Connect

    Welch, M.J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

  1. Positron Emission Tomography (PET)

    DOE R&D Accomplishments Database

    Welch, M. J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  2. Evaluation of the anti-HER2 C6.5 diabody as a PET radiotracer to monitor HER2 status and predict response to trastuzumab treatment

    PubMed Central

    Reddy, Smitha; Shaller, Calvin C.; Doss, Mohan; Shchaveleva, Irina; Marks, James D.; Yu, Jian Q.; Robinson, Matthew K.

    2011-01-01

    Purpose The rapid tumor targeting and pharmacokinetic properties of engineered antibodies make them potentially suitable for use in imaging strategies to predict and monitor response to targeted therapies. This study aims to evaluate C6.5 diabody (C6.5db), a non-covalent anti-HER2 single chain-Fv dimer, as a radiotracer for predicting response to HER2-targeted therapies such as trastuzumab. Experimental Design Immunodeficient mice bearing established HER2-positive tumor xenografts were injected with radioiodinated C6.5db and imaged using PET/CT. Radiotracer biodistribution was quantified using biopsied tumor and normal tissues. Potential competition between trastuzumab and C6.5db was examined in vitro by flow cytometry and co-immunoprecipitations. Results Biodistribution analysis of mice bearing xenografts with varying HER2 density revealed that the tumor uptake of 125I-C6.5db correlates with HER2 tumor density. In vitro competition experiments suggest that the C6.5db targets an epitope on HER2 that is distinct from that bound by trastuzumab. Treatment of SK-OV-3-tumored mice with trastuzumab for 3 d caused a 42% (P=0.002) decrease in tumor uptake of 125I-C6.5db. This is consistent with a dramatic decrease in the tumor PET signal of 124I-C6.5db after trastuzumab treatment. Furthermore, BT-474-tumored mice showed a ∼60% decrease (P=0.0026) in C6.5db uptake after 6 d of trastuzumab treatment. Immunohistochemistry of excised xenograft sections and in vitro flow cytometry revealed that the decreased C6.5db uptake upon trastuzumab treatment is not associated with HER2 downregulation. Conclusions These studies suggest that 124I-C6.5db-based imaging can be used to evaluate HER2 levels as a predictor of respone to HER2-directed therapies. PMID:21177408

  3. Comparison of 18F-FES, 18F-FDG, and 18F-FMISO PET Imaging Probes for Early Prediction and Monitoring of Response to Endocrine Therapy in a Mouse Xenograft Model of ER-Positive Breast Cancer

    PubMed Central

    Yang, ZhongYi; Zhang, JianPing; Zhang, YongPing; Luo, JianMin; Zhang, YingJian

    2016-01-01

    Background There is an increasing need to characterize biological processes for early prediction and monitoring of response to endocrine therapy in breast cancer using multiple positron emission tomography (PET) imaging probes. However, use of more than two PET tracers in a single clinical trial is quite challenging. In this study we carried out a longitudinal investigation of 18F-FES, 18F-FDG, and 18F-FMISO PET imaging probes for early prediction and monitoring of response to endocrine therapy in a mouse xenograft model of estrogen receptor (ER)-positive breast cancer. Method ER+ human breast cancer ZR-75-1 models were established in female mice that were then randomly assigned to a treatment (fulvestrant, 5.0 mg/week for 21 days) or vehicle group. Micro-PET/CT imaging with 18F-FES, 18F-FDG, and 18F-FMISO was performed on days 0, 3, 14, and 21 after treatment. The uptake value (percentage injected dose per gram, %ID/g) for each probe in tumor (T) tissue and contralateral muscle (M) was measured for quantitative analysis and T/M calculation. Tumor volume was measured to record tumor growth at each time point. Tumor tissues were sampled for immunohistochemical staining of ER expression. Correlations for tumor volume and ERα levels with uptake data for the probe were tested. Results Uptake data for 18F-FES in ZR-75-1 tumor tissues corresponded well with tumor response to endocrine therapy, but not for 18F-FDG and 18F-FMISO, according to longitudinal micro-PET/CT imaging and quantitative correlation analysis. There was a significant positive correlation between 18F-FES uptake and ER levels (%ID/gmax r2 = 0.76, P< 0.05; T/M r2 = 0.82, P<0.05). Notably, 18F-FES uptake on day 3 was significantly correlated with the day 21/baseline tumor volume ratio (%ID/gmax r2 = 0.74, P < 0.05; T/M r2 = 0.78, P < 0.05). Conclusions Comparison of 18F-FES, 18F-FDG, and 18F-FMISO probes revealed that 18F-FES PET/CT molecular imaging can provide a precise early prediction of tumor

  4. Joint PET-MR respiratory motion models for clinical PET motion correction.

    PubMed

    Manber, Richard; Thielemans, Kris; Hutton, Brian F; Wan, Simon; McClelland, Jamie; Barnes, Anna; Arridge, Simon; Ourselin, Sébastien; Atkinson, David

    2016-09-01

    Patient motion due to respiration can lead to artefacts and blurring in positron emission tomography (PET) images, in addition to quantification errors. The integration of PET with magnetic resonance (MR) imaging in PET-MR scanners provides complementary clinical information, and allows the use of high spatial resolution and high contrast MR images to monitor and correct motion-corrupted PET data. In this paper we build on previous work to form a methodology for respiratory motion correction of PET data, and show it can improve PET image quality whilst having minimal impact on clinical PET-MR protocols. We introduce a joint PET-MR motion model, using only 1 min per PET bed position of simultaneously acquired PET and MR data to provide a respiratory motion correspondence model that captures inter-cycle and intra-cycle breathing variations. In the model setup, 2D multi-slice MR provides the dynamic imaging component, and PET data, via low spatial resolution framing and principal component analysis, provides the model surrogate. We evaluate different motion models (1D and 2D linear, and 1D and 2D polynomial) by computing model-fit and model-prediction errors on dynamic MR images on a data set of 45 patients. Finally we apply the motion model methodology to 5 clinical PET-MR oncology patient datasets. Qualitative PET reconstruction improvements and artefact reduction are assessed with visual analysis, and quantitative improvements are calculated using standardised uptake value (SUV(peak) and SUV(max)) changes in avid lesions. We demonstrate the capability of a joint PET-MR motion model to predict respiratory motion by showing significantly improved image quality of PET data acquired before the motion model data. The method can be used to incorporate motion into the reconstruction of any length of PET acquisition, with only 1 min of extra scan time, and with no external hardware required. PMID:27524409

  5. The Value of 18F-FDG PET/CT Imaging Combined With Pretherapeutic Ki67 for Early Prediction of Pathologic Response After Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

    PubMed Central

    Luo, Jurui; Zhou, Zhirui; Yang, Zhaozhi; Chen, Xingxing; Cheng, Jinyi; Shao, Zhimin; Guo, Xiaomao; Tuan, Jeffrey; Fu, Xiaolong; Yu, Xiaoli

    2016-01-01

    Abstract To evaluate the value of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) and pretherapeutic Ki67 in predicting pathologic response in locally advanced breast cancer (LABC) after neoadjuvant chemotherapy (NAC). As a training set, total 301 LABC patients treated with NAC were retrospectively analyzed to evaluate the potential predictive value of pretherapeutic Ki67 for pathologic complete response (pCR) after NAC. Another 60 LABC patients were prospectively included as a validation set to evaluate the value of Ki67 combined PET/CT as pCR predictors. Ki67 was assessed in pretherapy core needle biopsy specimens and PET/CT scans were performed at baseline (before initiating NAC), after the 2nd, and 4th cycle of NAC. Maximum standardized uptake value (SUVmax) and its changes relative to baseline (ΔSUVmax%) were used as parameters of PEC/CT. In the training set, Ki67 was a predictor of pCR to NAC, with area under the curve (AUC) of 0.624 (P = 0.003) in receiver-operating characteristic (ROC) analysis. In the validation set, Ki67 alone did not show significant value in predicting pCR in the validation set. ΔSUVmax% after then 2nd or 4th course are predictors of pCR to NAC with the AUC of 0.774 (P = 0.002) and 0.791 (P = 0.002), respectively. When combined with ΔSUVmax% after the 2nd and 4th course NAC, Ki67 increased the value of ΔSUVmax% in predicting pCR with the AUC of 0.824 (P = 0.001). Baseline SUVmax and after 2nd, 4th course NAC had no predictive value for pCR, but SUVmax after the 2nd and 4th course showed remarkable predictive value for nonpathologic response (Grade 1 in Miller-Payne Grading System) with the AUC of 0.898 (P = 0.0001) and 0.801 (P = 0.003). Both PET/CT and Ki67 can predict pCR to NAC in LABC patients in the early phases of treatment. PET/CT combined Ki67 is a better pCR predictor for response to NAC. This helps the physician to predict the probability of pCR, and

  6. 18F-FDG PET/CT focal, but not osteolytic, lesions predict the progression of smoldering myeloma to active disease.

    PubMed

    Zamagni, E; Nanni, C; Gay, F; Pezzi, A; Patriarca, F; Bellò, M; Rambaldi, I; Tacchetti, P; Hillengass, J; Gamberi, B; Pantani, L; Magarotto, V; Versari, A; Offidani, M; Zannetti, B; Carobolante, F; Balma, M; Musto, P; Rensi, M; Mancuso, K; Dimitrakopoulou-Strauss, A; Chauviè, S; Rocchi, S; Fard, N; Marzocchi, G; Storto, G; Ghedini, P; Palumbo, A; Fanti, S; Cavo, M

    2016-02-01

    Identification of patient sub-groups with smoldering multiple myeloma (SMM) at high risk of progression to active disease (MM) is an important goal. 18F-FDG PET/CT (positron emission tomography (PET) integrated with computed tomography (PET/CT) using glucose labelled with the positron-emitting radionuclide (18)F) allows for assessing early skeletal involvement. Identification of osteolytic lesions by this technique has recently been incorporated into the updated International Myeloma Working Group criteria for MM diagnosis. However, no data are available regarding the impact of focal lesions (FLs) without underlying osteolysis on time to progression (TTP) to MM. We hence prospectively studied a cohort of 120 SMM patients with PET/CT. PET/CT was positive in 16% of patients (1 FL: 8, 2 FLs: 3, >3 FLs: 6, diffuse bone marrow involvement: 2). With a median follow-up of 2.2 years, 38% of patients progressed to MM, in a median time of 4 years, including 21% with skeletal involvement. The risk of progression of those with positive PET/CT was 3.00 (95% confidence interval 1.58-5.69, P=0.001), with a median TTP of 1.1 versus 4.5 years for PET/CT-negative patients. The probability of progression within 2 years was 58% for positive versus 33% for negative patients. In conclusion, PET/CT positivity significantly increased the risk of progression of SMM to MM. PET/CT could become a new tool to define high-risk SMM. PMID:26490489

  7. Exploring the nature of atheroma and cardiovascular inflammation in vivo using positron emission tomography (PET).

    PubMed

    Buscombe, J R

    2015-09-01

    Positron emission tomography (PET) has become widely established in oncology. Subsequently, a whole new “toolbox” of tracers have become available to look at different aspects of cancer cell function and dysfunction, including cell protein production, DNA synthesis, hypoxia and angiogenesis. In the past 5 years, these tools have been used increasingly to look at the other great killer of the developed world: cardiovascular disease. For example, inflammation of the unstable plaque can be imaged with 18-fludeoxyglucose (18F-FDG), and this uptake can be quantified to show the effect that statins have in reducing inflammation and explains how these drugs can reduce the risk of stroke. 18F-FDG has also become established in diagnosing and monitoring large-vessel vasculitis and has now entered routine practice. Other agents such as gallium-68 (68Ga) octreotide have been shown to identify vascular inflammation possibly more specifically than 18FFDG.Hypoxia within the plaque can be imaged with 18F-fluoromisonidazole and resulting angiogenesis with 18F-RGD peptides. Active calcification such as that found in unstable atheromatous plaques can be imaged with 18F-NaF. PET imaging enables us to understand the mechanisms by which cardiovascular disease, including atheroma, leads tomorbidity and death and thus increases the chance of finding new and effective treatments. PMID:26110339

  8. Effect of intratumoral heterogeneity in oxygenation status on FMISO PET, autoradiography, and electrode PO {sub 2} measurements in murine tumors

    SciTech Connect

    Sorensen, Michael . E-mail: michael@pet.auh.dk; Horsman, Michael R.; Cumming, Paul; Munk, Ole Lajord; Keiding, Susanne

    2005-07-01

    Purpose: To explore conflicting results obtained when tumor hypoxia is assessed with Eppendorf electrode PO {sub 2} measurements and with positron emission tomography (PET) by use of [{sup 18}F]fluoromisonidazole (FMISO). Methods and Materials: We compared the 2 methods in conjunction with 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG) PET, dual-tracer ex vivo autoradiography (FMISO and 2-deoxy-D-[1-{sup 14}C]glucose (2DG)), and histology in 2 murine tumor models, the C3H mammary carcinoma and the SCCVII squamous cell carcinoma. Results: 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG)-PET showed tumor-to-reference tissue ratios of 3.5 in both tumor models after 2 hours. C3H mammary carcinoma reached an FMISO PET ratio of 11 after 3.5 hours. Autoradiography showed large confluent areas of FMISO and 2DG uptake. Median PO {sub 2} was 7 mm Hg and necrotic fraction was 10% to 30%. SCCVII squamous-cell carcinoma reached an FMISO PET tumor-to-reference tissue ratio of 2 after 2.5 hours. Autoradiography showed homogeneous 2DG uptake and scattered foci of high FMISO uptake. Median PO {sub 2} was 1 mm Hg and necrotic fraction was below 5%. Conclusions: Ex vivo dual-tracer autoradiography documented the ability of in vivo FMISO PET to distinguish between confluent areas of either viable tissue or necrosis. Electrode PO {sub 2} measurements could not be ascribed to specific areas in the tumors. Less uptake of FMISO in SCCVII squamous-cell carcinoma than in C3H mammary carcinoma could be caused by scattered foci versus confluent areas of viable hypoxic tissue in the 2 tumors, respectively.

  9. Pet Health

    MedlinePlus

    ... Know the signs of medical problems. Take your pet to the veterinarian if you notice: Loss of appetite Drinking a lot of water Gaining or losing a lot of weight quickly Strange behavior Being sluggish and tired Trouble getting up or down Strange lumps

  10. Both F-18 FDG-avidity and Malignant Shape of Cervical Lymph Nodes on PET/CT after Total Thyroidectomy Predict Resistance to High-dose I-131 Therapy in Patients with Papillary Thyroid Cancer

    PubMed Central

    Byun, Byung Hyun; Kwon, Seong Young; Chong, Ari; Kim, Jahae; Yoo, Su Woong; Min, Jung-Joon; Song, Ho-Chun; Bom, Henry Hee-Seung

    2013-01-01

    Objective: Resistance of metastatic lymph nodes (LNs) to high dose I-131 therapy is associated with high morbidity in patients with differentiated thyroid cancer. We evaluated the role of F-18 FDG PET/CT in the prediction of resistance to high dose I-131 therapy in patients with papillary thyroid cancer. Methods: The subjects were 307 patients who underwent total or near total thyroidectomy followed by high dose (5.55-6.66 GBq) I-131 therapy. We divided the patients into three subgroups by visual assessment of regional LNs: FDG-avid LNs with a malignant shape on CT (PET/CT-positive group), FDG-avid LNs with a benign shape on CT (PET/CT-intermediate group) and no FDG-avid lesion (PET/CT-negative group). We measured the maximum SUV (SUVmax) of FDG-avid LNs in each patient. The presence or absence of focal increased uptake of I-131 was evaluated by whole body scan (WBS), and was denoted as WBS-positive group or WBS-negative group, respectively. Resistance to therapy was defined as presence of thyroglobulin (Tg) in serum (Tg ≥1.0 ng/ml) 3-6 months after I-131 therapy. Univariate and multivariate analyses were performed to determine the relationship between resistance to I-131 therapy and various clinico-pathologic variables. Results: PET/CT-positive, intermediate, and negative groups included 20 (6.5%), 44 (14.3%) and 243 (79.2%) patients, respectively. The mean SUVmax was significantly higher in the PET/CT-positive group than that of the PET/CT-intermediate group (4.6 vs. 2.7, P <0.001). Univariate analysis revealed that the PET/CT-positive group (P <0.001), T2-4 stage (P <0.001), N1b stage (P = 0.001), lower dose (5.55 GBq) of I-131 (P <0.001), and the WBS-positive group (P = 0.029) were associated with resistance to therapy. In multivariate analysis, the PET/CT-positive group, lower dose of I-131, N1b stage, and T2-4 stage remained significant with odds ratios of 10.07 (P <0.001), 3.82 (P <0.001), 3.58 (P = 0.001), and 2.53 (P = 0.009), respectively. Conclusion

  11. Proton Therapy Verification with PET Imaging

    PubMed Central

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions, and approaches for data evaluation are discussed. PMID:24312147

  12. GABAA receptors predict aversion-related brain responses: an fMRI-PET investigation in healthy humans.

    PubMed

    Hayes, Dave J; Duncan, Niall W; Wiebking, Christine; Pietruska, Karin; Qin, Pengmin; Lang, Stefan; Gagnon, Jean; Bing, Paul Gravel; Verhaeghe, Jeroen; Kostikov, Alexey P; Schirrmacher, Ralf; Reader, Andrew J; Doyon, Julien; Rainville, Pierre; Northoff, Georg

    2013-07-01

    The perception of aversive stimuli is essential for human survival and depends largely on environmental context. Although aversive brain processing has been shown to involve the sensorimotor cortex, the neural and biochemical mechanisms underlying the interaction between two independent aversive cues are unclear. Based on previous work indicating ventromedial prefrontal cortex (vmPFC) involvement in the mediation of context-dependent emotional effects, we hypothesized a central role for the vmPFC in modulating sensorimotor cortex activity using a GABAergic mechanism during an aversive-aversive stimulus interaction. This approach revealed differential activations within the aversion-related network (eg, sensorimotor cortex, midcingulate, and insula) for the aversive-aversive, when compared with the aversive-neutral, interaction. Individual differences in sensorimotor cortex signal changes during the aversive-aversive interaction were predicted by GABAA receptors in both vmPFC and sensorimotor cortex. Together, these results demonstrate the central role of GABA in mediating context-dependent effects in aversion-related processing. PMID:23389691

  13. TU-F-12A-03: Using 18F-FDG-PET-CT and Deformable Registration During Head-And-Neck Cancer (HNC) Intensity Modulated Radiotherapy (IMRT) to Predict Treatment Response

    SciTech Connect

    Vergalasova, I; Mowery, Y; Yoo, D; Brizel, D; Das, S

    2014-06-15

    neither registration should be solely relied upon for nodal GTVs. Of the four SUV parameters found to be predictive of CR vs. ICR, SUV-MEAN was the strongest. Preliminary results show promise for using intra-treatment 18F-FDG-PET-CT with deformable registration to predict treatment response.

  14. FDG-PET imaging in hematological malignancies.

    PubMed

    Valls, L; Badve, C; Avril, S; Herrmann, K; Faulhaber, P; O'Donnell, J; Avril, N

    2016-07-01

    The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques. PMID:27090170

  15. Pet Problems at Home: Pet Problems in the Community.

    ERIC Educational Resources Information Center

    Soltow, Willow

    1984-01-01

    Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

  16. Pet Bonding and Pet Bereavement among Adolescents.

    ERIC Educational Resources Information Center

    Brown, Brenda H.; And Others

    1996-01-01

    Studied adolescent-pet bonding and bereavement following pet loss (n=55). Hypothesized that highly-bonded adolescents experience more intense grief when a pet dies than do those less bonded; degree of bonding is greater for girls than for boys; and intensity of bereavement is greater for girls than for boys. Results supported the hypotheses. (RB)

  17. TBCRC 008: Early Change in 18F-FDG Uptake on PET Predicts Response to Preoperative Systemic Therapy in Human Epidermal Growth Factor Receptor 2–Negative Primary Operable Breast Cancer

    PubMed Central

    Connolly, Roisin M.; Leal, Jeffrey P.; Goetz, Matthew P.; Zhang, Zhe; Zhou, Xian C.; Jacobs, Lisa K.; Mhlanga, Joyce; Joo, H O; Carpenter, John; Storniolo, Anna Maria; Watkins, Stanley; Fetting, John H.; Miller, Robert S.; Sideras, Kostandinos; Jeter, Stacie C.; Walsh, Bridget; Powers, Penny; Zorzi, Jane; Boughey, Judy C.; Davidson, Nancy E.; Carey, Lisa A.; Wolff, Antonio C.; Khouri, Nagi; Gabrielson, Edward; Wahl, Richard L.; Stearns, Vered

    2015-01-01

    Epigenetic modifiers, including the histone deacetylase inhibitor vorinostat, may sensitize tumors to chemotherapy and enhance outcomes. We conducted a multicenter randomized phase II neo-adjuvant trial of carboplatin and nanoparticle albumin-bound paclitaxel (CP) with vorinostat or placebo in women with stage II/III, human epidermal growth factor receptor 2 (HER2)–negative breast cancer, in which we also examined whether change in maximum standardized uptake values corrected for lean body mass (SULmax) on 18F-FDG PET predicted pathologic complete response (pCR) in breast and axillary lymph nodes. Methods Participants were randomly assigned to 12 wk of preoperative carboplatin (area under the curve of 2, weekly) and nab-paclitaxel (100 mg/m2 weekly) with vorinostat (400 mg orally daily, days 1–3 of every 7-d period) or placebo. All patients underwent 18F-FDG PET and research biopsy at baseline and on cycle 1 day 15. The primary endpoint was the pCR rate. Secondary objectives included correlation of change in tumor SULmax on 18F-FDG PET by cycle 1 day 15 with pCR and correlation of baseline and change in Ki-67 with pCR. Results In an intent-to-treat analysis (n = 62), overall pCR was 27.4% (vorinostat, 25.8%; placebo, 29.0%). In a pooled analysis (n = 59), we observed a significant difference in median change in SULmax 15 d after initiating preoperative therapy between those achieving pCR versus not (percentage reduction, 63.0% vs. 32.9%; P = 0.003). Patients with 50% or greater reduction in SULmax were more likely to achieve pCR, which remained statistically significant in multivariable analysis including estrogen receptor status (odds ratio, 5.1; 95% confidence interval, 1.3–22.7; P = 0.023). Differences in baseline and change in Ki-67 were not significantly different between those achieving pCR versus not. Conclusion Preoperative CP with vorinostat or placebo is associated with similar pCR rates. Early change in SULmax on 18F-FDG PET 15 d after the

  18. PK-PD modeling of individual lesion FDG-PET response to predict overall survival in patients with sunitinib-treated gastrointestinal stromal tumor.

    PubMed

    Schindler, E; Amantea, M A; Karlsson, M O; Friberg, L E

    2016-04-01

    Pharmacometric models were developed to characterize the relationships between lesion-level tumor metabolic activity, as assessed by the maximum standardized uptake value (SUVmax) obtained on [(18)F]-fluorodeoxyglucose (FDG) positron emission tomography (PET), tumor size, and overall survival (OS) in 66 patients with gastrointestinal stromal tumor (GIST) treated with intermittent sunitinib. An indirect response model in which sunitinib stimulates tumor loss best described the typically rapid decrease in SUVmax during on-treatment periods and the recovery during off-treatment periods. Substantial interindividual and interlesion variability were identified in SUVmax baseline and drug sensitivity. A parametric time-to-event model identified the relative change in SUVmax at one week for the lesion with the most pronounced response as a better predictor of OS than tumor size. Based on the proposed modeling framework, early changes in FDG-PET response may serve as predictor for long-term outcome in sunitinib-treated GIST. PMID:27299707

  19. Microglia activation in multiple sclerosis black holes predicts outcome in progressive patients: an in vivo [(11)C](R)-PK11195-PET pilot study.

    PubMed

    Giannetti, Paolo; Politis, Marios; Su, Paul; Turkheimer, Federico; Malik, Omar; Keihaninejad, Shiva; Wu, Kit; Reynolds, Richard; Nicholas, Richard; Piccini, Paola

    2014-05-01

    The pathophysiological correlates and the contribution to persisting disability of hypointense T1-weighted MRI lesions, black holes (BH), in multiple sclerosis (MS) are still unclear. In order to study the in vivo functional correlates of this MRI finding, we used 11C-PK11195 PET (PK-PET) to investigate changes in microglial activity. Ten relapsing and 9 progressive MS subjects had a PK-PET scan and a MRI scan alongside a full clinical assessment, including the expanded disability status scale (EDSS) for evaluation of disability. We studied the PK binding potential of the specifically bound radioligand relative to the non-displaceable radioligand in tissue (BPND) in T1 BHs. Out of a total of 1242 BHs identified, 947 were PK enhancing. The PKBPND was correlated with the EDSS (r=0.818; p<0.05) only in the progressive group. In the relapsing patients there was an inverse correlation between PKBPND and BH total lesion volume in whole brain (r=-0.781; p<0.05). When progressive patients were grouped according to the disability outcome at 2years from the PK-PET scan, the total PKBPND in BHs was found to be a significant outcome predictor of disability (p<0.01). Our findings show that relapsing and progressive patients have heterogeneous patterns of PKBPND in T1 BHs and indicate that BHs are not just "holes" representing loss of axons and myelin, but display inflammatory activity in the form of activated microglia. The significant association between PKBPND, neurological impairment and outcome in progressive subjects supports a role for activated microglia in disability progression. PMID:24508617

  20. Maximum Standardized Uptake Value From Staging FDG-PET/CT Does not Predict Treatment Outcome for Early-Stage Non-Small-Cell Lung Cancer Treated With Stereotactic Body Radiotherapy

    SciTech Connect

    Burdick, Michael J.; Stephans, Kevin L.; Reddy, Chandana A.; Djemil, Toufik; Srinivas, Shyam M.; Videtic, Gregory M.M.

    2010-11-15

    Purpose: To perform a retrospective review to determine whether maximum standardized uptake values (SUV{sub max}) from staging 2-deoxy-2- [{sup 18}F] fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) studies are associated with outcomes for early-stage non-small-cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Methods and Materials: Seventy-two medically inoperable patients were treated between October 17, 2003 and August 17, 2007 with SBRT for T1-2N0M0 NSCLC. SBRT was administered as 60 Gy in 3 fractions, 50 Gy in 5 fractions, or 50 Gy in 10 fractions using abdominal compression and image-guided SBRT. Cox proportional hazards regression was performed to determine whether PET SUV{sub max} and other variables influenced outcomes: mediastinal failure (MF), distant metastases (DM), and overall survival (OS). Results: Biopsy was feasible in 49 patients (68.1%). Forty-nine patients had T1N0 disease, and 23 had T2N0 disease. Median SUV{sub max} was 6.55 (range, 1.5-21). Median follow-up was 16.9 months (range, 0.1-37.9 months). There were 3 local failures, 8 MF, 19 DM, and 30 deaths. Two-year local control, MF, DM, and OS rates were 94.0%, 10.4%, 30.1%, and 61.3%, respectively. In univariate analysis, PET/CT SUV{sub max}, defined either as a continuous or dichotomous variable, did not predict for MF, DM, or OS. On multivariable analysis, the only predictors for overall survival were T1 stage (hazard ratio = 0.331 [95% confidence interval, 0.156-0.701], p = 0.0039) and smoking pack-year history (hazard ratio = 1.015 [95% confidence interval, 1.004-1.026], p = 0.0084). Conclusions: Pretreatment PET SUV{sub max} did not predict for MF, DM, or OS in patients treated with SBRT for early-stage NSCLC.

  1. Subdomain 2 of the Autotransporter Pet Is the Ligand Site for Recognizing the Pet Receptor on the Epithelial Cell Surface.

    PubMed

    Chavez-Dueñas, Lucia; Serapio-Palacios, Antonio; Nava-Acosta, Raul; Navarro-Garcia, Fernando

    2016-07-01

    Most autotransporter passenger domains, regardless of their diversity in function, fold or are predicted to fold as right-handed β-helices carrying various loops that are presumed to confer functionality. Our goal here was to identify the subdomain (loop) or amino acid sequence of the Pet passenger domain involved in the receptor binding site on the host cell for Pet endocytosis. Here, we show that d1 and d2 subdomains, as well as the amino acid sequence linking the subdomain d2 and the adjacent β-helix (PDWET), are not required for Pet secretion through the autotransporter system and that none of our deletion mutants altered the predicted long right-handed β-helical structure. Interestingly, Pet lacking the d2 domain (PetΔd2) was unable to bind on the epithelial cell surface, in contrast to Pet lacking d1 (PetΔd1) subdomain or PDWET sequences. Moreover, the purified d1 subdomain, the biggest subdomain (29.8 kDa) containing the serine protease domain, was also unable to bind the cell surface. Thus, d2 sequence (54 residues without the PDWET sequence) was required for Pet binding to eukaryotic cells. In addition, this d2 sequence was also needed for Pet internalization but not for inducing cell damage. In contrast, PetΔd1, which was able to bind and internalize inside the cell, was unable to cause cell damage. Furthermore, unlike Pet, PetΔd2 was unable to bind cytokeratin 8, a Pet receptor. These data indicate that the surface d2 subdomain is essential for the ligand-receptor (Pet-Ck8) interaction for Pet uptake and to start the epithelial cell damage by this toxin. PMID:27113356

  2. Trends in PET imaging

    SciTech Connect

    Moses, William W.

    2000-11-01

    Positron Emission Tomography (PET) imaging is a well established method for obtaining information on the status of certain organs within the human body or in animals. This paper presents an overview of recent trends PET instrumentation. Significant effort is being expended to develop new PET detector modules, especially those capable of measuring depth of interaction. This is aided by recent advances in scintillator and pixellated photodetector technology. The other significant area of effort is development of special purpose PET cameras (such as for imaging breast cancer or small animals) or cameras that have the ability to image in more than one modality (such as PET / SPECT or PET / X-Ray CT).

  3. Residual {sup 18}F-FDG-PET Uptake 12 Weeks After Stereotactic Ablative Radiotherapy for Stage I Non-Small-Cell Lung Cancer Predicts Local Control

    SciTech Connect

    Bollineni, Vikram Rao; Widder, Joachim; Pruim, Jan; Langendijk, Johannes A.; Wiegman, Erwin M.

    2012-07-15

    Purpose: To investigate the prognostic value of [{sup 18}F]fluorodeoxyglucose positron emission tomography (FDG-PET) uptake at 12 weeks after stereotactic ablative radiotherapy (SABR) for stage I non-small-cell lung cancer (NSCLC). Methods and Materials: From November 2006 to February 2010, 132 medically inoperable patients with proven Stage I NSCLC or FDG-PET-positive primary lung tumors were analyzed retrospectively. SABR consisted of 60 Gy delivered in 3 to 8 fractions. Maximum standardized uptake value (SUV{sub max}) of the treated lesion was assessed 12 weeks after SABR, using FDG-PET. Patients were subsequently followed at regular intervals using computed tomography (CT) scans. Association between post-SABR SUV{sub max} and local control (LC), mediastinal failure, distant failure, overall survival (OS), and disease-specific survival (DSS) was examined. Results: Median follow-up time was 17 months (range, 3-40 months). Median lesion size was 25 mm (range, 9-70 mm). There were 6 local failures: 15 mediastinal failures, 15 distant failures, 13 disease-related deaths, and 16 deaths from intercurrent diseases. Glucose corrected post-SABR median SUV{sub max} was 3.0 (range, 0.55-14.50). Using SUV{sub max} 5.0 as a cutoff, the 2-year LC was 80% versus 97.7% for high versus low SUV{sub max}, yielding an adjusted subhazard ratio (SHR) for high post-SABR SUV{sub max} of 7.3 (95% confidence interval [CI], 1.4-38.5; p = 0.019). Two-year DSS rates were 74% versus 91%, respectively, for high and low SUV{sub max} values (SHR, 2.2; 95% CI, 0.8-6.3; p = 0.113). Two-year OS was 62% versus 81% (hazard ratio [HR], 1.6; 95% CI, 0.7-3.7; p = 0.268). Conclusions: Residual FDG uptake (SUV{sub max} {>=}5.0) 12 weeks after SABR signifies increased risk of local failure. A single FDG-PET scan at 12 weeks could be used to tailor further follow-up according to the risk of failure, especially in patients potentially eligible for salvage surgery.

  4. Breast PET scan

    MedlinePlus

    ... medlineplus.gov/ency/article/007469.htm Breast PET scan To use the sharing features on this page, ... enable JavaScript. A breast positron emission tomography (PET) scan is an imaging test that uses a radioactive ...

  5. Heart PET scan

    MedlinePlus

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  6. Birds Kept as Pets

    MedlinePlus

    ... restricts the importation of pet birds from certain countries and enforces a 30-day quarantine for all imported birds except those that come from Canada. People interested in importing pet birds should visit the USDA non-US Origin Pet Bird Importation website . Choosing a bird Match ...

  7. Clinical Utility and Future Applications of PET/CT and PET/CMR in Cardiology.

    PubMed

    Pan, Jonathan A; Salerno, Michael

    2016-01-01

    Over the past several years, there have been major advances in cardiovascular positron emission tomography (PET) in combination with either computed tomography (CT) or, more recently, cardiovascular magnetic resonance (CMR). These multi-modality approaches have significant potential to leverage the strengths of each modality to improve the characterization of a variety of cardiovascular diseases and to predict clinical outcomes. This review will discuss current developments and potential future uses of PET/CT and PET/CMR for cardiovascular applications, which promise to add significant incremental benefits to the data provided by each modality alone. PMID:27598207

  8. Quantitative metrics of net proliferation and invasion link biological aggressiveness assessed by MRI with hypoxia assessed by FMISO-PET in newly diagnosed glioblastomas.

    PubMed

    Szeto, Mindy D; Chakraborty, Gargi; Hadley, Jennifer; Rockne, Russ; Muzi, Mark; Alvord, Ellsworth C; Krohn, Kenneth A; Spence, Alexander M; Swanson, Kristin R

    2009-05-15

    Glioblastoma multiforme (GBM) are aggressive and uniformly fatal primary brain tumors characterized by their diffuse invasion of the normal-appearing parenchyma peripheral to the clinical imaging abnormality. Hypoxia, a hallmark of aggressive tumor behavior often noted in GBMs, has been associated with resistance to therapy, poorer survival, and more malignant tumor phenotypes. Based on the existence of a set of novel imaging techniques and modeling tools, our objective was to assess a hypothesized quantitative link between tumor growth kinetics [assessed via mathematical models and routine magnetic resonance imaging (MRI)] and the hypoxic burden of the tumor [assessed via positron emission tomography (PET) imaging]. Our biomathematical model for glioma kinetics describes the spatial and temporal evolution of a glioma in terms of concentration of malignant tumor cells. This model has already been proven useful as a novel tool to dynamically quantify the net rates of proliferation (rho) and invasion (D) of the glioma cells in individual patients. Estimates of these kinetic rates can be calculated from routinely available pretreatment MRI in vivo. Eleven adults with GBM were imaged preoperatively with (18)F-fluoromisonidazole (FMISO)-PET and serial gadolinium-enhanced T1- and T2-weighted MRIs to allow the estimation of patient-specific net rates of proliferation (rho) and invasion (D). Hypoxic volumes were quantified from each FMISO-PET scan following standard techniques. To control for tumor size variability, two measures of hypoxic burden were considered: relative hypoxia (RH), defined as the ratio of the hypoxic volume to the T2-defined tumor volume, and the mean intensity on FMISO-PET scaled to the blood activity of the tracer (mean T/B). Pearson correlations between RH and the net rate of cell proliferation (rho) reached significance (P < 0.04). Moreover, highly significant positive correlations were found between biological aggressiveness ratio (rho/D) and both

  9. Metformin, an Adjunct Antineoplastic Therapy, Divergently Modulates Tumor Metabolism and Proliferation, Interfering with Early Response Prediction Using 18F-FDG PET Imaging

    PubMed Central

    Habibollahi, Peiman; van den Berg, Nynke S.; Kuruppu, Darshini; Loda, Massimo; Mahmood, Umar

    2013-01-01

    Over the last several years epidemiological data has emerged which suggests that the anti-diabetic drug metformin (MET), an AMP-activated protein kinase (AMPK) activator, improves progression free survival in multiple cancers; more than 30 clinical trials are underway to confirm this finding. We postulated that the role of AMPK as a central cellular energy sensor would result in opposite effects on glucose uptake and proliferation, suggesting different roles for 18F-FDG and 18F-FLT in assessing its effectiveness as an anti-neoplastic agent. Methods Colon cancer cell lines HT29 (human) and MC26 (murine) were treated for 24 or 72hrs with a range of MET (0–10mM). Western blotting was used to study the activation of AMPK after MET treatment. Glucose uptake and cell proliferation were measured by cell retention studies with either 18F-FDG or 18F-FLT. EdU (a thymidine analogue) and Annexin-Propidium Iodine flow cytometry were performed to determine cell cycle S-phase and apoptotic changes. In vivo 18F-FDG and 18F-FLT PET images were acquired before and 24hrs after MET treatment on HT29 tumor bearing mice. Results After 24hrs of MET incubation, phosphorylated AMPK increased several fold in both cell lines while total AMPK was unchanged. In cell retention studies, 18F-FDG uptake increased whereas 18F-FLT retention decreased significantly in both cell lines. Cells in S-phase decreased 36% in HT29 and 33% in MC26 cells following MET therapy. Apoptosis increased 10.5× and 5.8×, in HT29 and MC26 cells, respectively after 72hrs of incubation with MET. PET imaging showed increased 18F-FDG uptake (mean SUV: 0.71±0.03 and 1.29±0.11 pre and post MET therapy, p<0.05) and decreased 18F-FLT uptake (mean SUV: 1.18±0.05 and 0.89±0.01 pre and post MET therapy, p<0.05) in HT29 tumor bearing mice. Conclusion MET, through activation of the AMPK pathway, exerts a dose dependent increase in tumor glucose uptake while decreasing cell proliferation in human and murine colon cancer cells

  10. Respiration-Averaged CT for Attenuation Correction of PET Images – Impact on PET Texture Features in Non-Small Cell Lung Cancer Patients

    PubMed Central

    Cheng, Nai-Ming; Fang, Yu-Hua Dean; Tsan, Din-Li

    2016-01-01

    Purpose We compared attenuation correction of PET images with helical CT (PET/HCT) and respiration-averaged CT (PET/ACT) in patients with non-small-cell lung cancer (NSCLC) with the goal of investigating the impact of respiration-averaged CT on 18F FDG PET texture parameters. Materials and Methods A total of 56 patients were enrolled. Tumors were segmented on pretreatment PET images using the adaptive threshold. Twelve different texture parameters were computed: standard uptake value (SUV) entropy, uniformity, entropy, dissimilarity, homogeneity, coarseness, busyness, contrast, complexity, grey-level nonuniformity, zone-size nonuniformity, and high grey-level large zone emphasis. Comparisons of PET/HCT and PET/ACT were performed using Wilcoxon signed-rank tests, intraclass correlation coefficients, and Bland-Altman analysis. Receiver operating characteristic (ROC) curves as well as univariate and multivariate Cox regression analyses were used to identify the parameters significantly associated with disease-specific survival (DSS). A fixed threshold at 45% of the maximum SUV (T45) was used for validation. Results SUV maximum and total lesion glycolysis (TLG) were significantly higher in PET/ACT. However, texture parameters obtained with PET/ACT and PET/HCT showed a high degree of agreement. The lowest levels of variation between the two modalities were observed for SUV entropy (9.7%) and entropy (9.8%). SUV entropy, entropy, and coarseness from both PET/ACT and PET/HCT were significantly associated with DSS. Validation analyses using T45 confirmed the usefulness of SUV entropy and entropy in both PET/HCT and PET/ACT for the prediction of DSS, but only coarseness from PET/ACT achieved the statistical significance threshold. Conclusions Our results indicate that 1) texture parameters from PET/ACT are clinically useful in the prediction of survival in NSCLC patients and 2) SUV entropy and entropy are robust to attenuation correction methods. PMID:26930211

  11. Clinical Utility of Multimodality Imaging with Dynamic Contrast-Enhanced MRI, Diffusion-Weighted MRI, and 18F-FDG PET/CT for the Prediction of Neck Control in Oropharyngeal or Hypopharyngeal Squamous Cell Carcinoma Treated with Chemoradiation

    PubMed Central

    Chan, Sheng-Chieh; Lin, Yu-Chun; Yen, Tzu-Chen; Liao, Chun-Ta; Chang, Joseph Tung-Chieh; Ko, Sheung-Fat; Wang, Hung- Ming; Chang, Chee-Jen; Wang, Jiun-Jie

    2014-01-01

    The clinical usefulness of pretreatment imaging techniques for predicting neck control in patients with oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC) treated with chemoradiation remains unclear. In this prospective study, we investigated the role of pretreatment dynamic contrast-enhanced perfusion MR imaging (DCE-PWI), diffusion-weighted MR imaging (DWI), and [18F]fluorodeoxyglucose-positron emission tomography (18F-FDG PET)/CT derived imaging markers for the prediction of neck control in OHSCC patients treated with chemoradiation. Patients with untreated OHSCC scheduled for chemoradiation between August, 2010 and July, 2012 were eligible for the study. Clinical variables and the following imaging parameters of metastatic neck lymph nodes were examined in relation to neck control: transfer constant, volume of blood plasma, and volume of extracellular extravascular space (Ve) on DCE-PWI; apparent diffusion coefficient (ADC) on DWI; maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis on 18F-FDG PET/CT. There were 69 patients (37 with oropharynx SCC and 32 with hypopharynx SCC) with successful pretreatment DCE-PWI and DWI available for analysis. After a median follow-up of 31 months, 25 (36.2%) participants had neck failure. Multivariate analysis identified hemoglobin level <14.3 g/dL (P = 0.019), Ve <0.23 (P = 0.040), and ADC >1.14×10−3 mm2/s (P = 0.003) as independent prognostic factors for 3-year neck control. A prognostic scoring system was formulated by summing up the three significant predictors of neck control. Patients with scores of 2–3 had significantly poorer neck control and overall survival rates than patients with scores of 0–1. We conclude that hemoglobin levels, Ve, and ADC are independent pretreatment prognostic factors for neck control in OHSCC treated with chemoradiation. Their combination may identify a subgroup of patients at high risk of developing neck failure. PMID:25531391

  12. My Pet Rock

    ERIC Educational Resources Information Center

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  13. Improving Instruction through PET.

    ERIC Educational Resources Information Center

    Evans, Pamela Roland

    1982-01-01

    Outlines the content and training methods used in the Program for Effective Teaching (PET), the successful staff development program of Newport News (Virginia). PET promotes application of five instructional skills: selecting learning objectives, teaching to the objectives, establishing learner focus, monitoring learner progress, and enhancing…

  14. [Oncology PET imaging].

    PubMed

    Inubushi, Masayuki

    2014-01-01

    At the beginning of this article, likening medical images to "Where is Waldo?" I indicate the concept of diagnostic process of PET/CT imaging, so that medical physics specialists could understand the role of each imaging modality and infer our distress for image diagnosis. Then, I state the present situation of PET imaging and the basics (e.g. health insurance coverage, clinical significance, principle, protocol, and pitfall) of oncology FDG-PET imaging which accounts for more than 99% of all clinical PET examinations in Japan. Finally, I would like to give a wishful prospect of oncology PET that will expand to be more cancer-specific in order to assess therapeutic effects of emerging molecular targeted drugs targeting the "hallmarks of cancer". PMID:25199271

  15. Healthy pets, healthy people.

    PubMed

    Wong, S K; Feinstein, L H; Heidmann, P

    1999-08-01

    Zoonoses, diseases that can be transmitted from animals to humans, can pose serious health risks to immunocompromised people. Although pets can carry zoonoses, owning and caring for animals can benefit human health. Information exists about preventing transmission of zoonoses, but not all physicians and veterinarians provide adequate and accurate information to immunocompromised pet owners. This disease prevention/health promotion project provides physicians and veterinarians with information, created specifically to share with patients and clients, about the health risks and benefits of pet ownership. Further, "Healthy Pets, Healthy People" encourages communication between veterinarians, physicians, clients, and patients and can serve as a model program for a nation-wide effort to aid health professionals in making recommendations about pet ownership for immunocompromised people. PMID:10434969

  16. SU-C-204-01: A Fast Analytical Approach for Prompt Gamma and PET Predictions in a TPS for Proton Range Verification

    SciTech Connect

    Kroniger, K; Herzog, M; Landry, G; Dedes, G; Parodi, K; Traneus, E

    2015-06-15

    Purpose: We describe and demonstrate a fast analytical tool for prompt-gamma emission prediction based on filter functions applied on the depth dose profile. We present the implementation in a treatment planning system (TPS) of the same algorithm for positron emitter distributions. Methods: The prediction of the desired observable is based on the convolution of filter functions with the depth dose profile. For both prompt-gammas and positron emitters, the results of Monte Carlo simulations (MC) are compared with those of the analytical tool. For prompt-gamma emission from inelastic proton-induced reactions, homogeneous and inhomogeneous phantoms alongside with patient data are used as irradiation targets of mono-energetic proton pencil beams. The accuracy of the tool is assessed in terms of the shape of the analytically calculated depth profiles and their absolute yields, compared to MC. For the positron emitters, the method is implemented in a research RayStation TPS and compared to MC predictions. Digital phantoms and patient data are used and positron emitter spatial density distributions are analyzed. Results: Calculated prompt-gamma profiles agree with MC within 3 % in terms of absolute yield and reproduce the correct shape. Based on an arbitrary reference material and by means of 6 filter functions (one per chemical element), profiles in any other material composed of those elements can be predicted. The TPS implemented algorithm is accurate enough to enable, via the analytically calculated positron emitters profiles, detection of range differences between the TPS and MC with errors of the order of 1–2 mm. Conclusion: The proposed analytical method predicts prompt-gamma and positron emitter profiles which generally agree with the distributions obtained by a full MC. The implementation of the tool in a TPS shows that reliable profiles can be obtained directly from the dose calculated by the TPS, without the need of full MC simulation.

  17. Accuracy of [18F]FDG PET/MRI for the Detection of Liver Metastases

    PubMed Central

    Beiderwellen, Karsten; Geraldo, Llanos; Ruhlmann, Verena; Heusch, Philipp; Gomez, Benedikt; Nensa, Felix; Umutlu, Lale; Lauenstein, Thomas C.

    2015-01-01

    Background The aim of this study was to compare the diagnostic accuracy of [18F]FDG-PET/MRI with PET/CT for the detection of liver metastases. Methods 32 patients with solid malignancies underwent [18F]FDG-PET/CT and subsequent PET/MRI of the liver. Two readers assessed both datasets regarding lesion characterization (benign, indeterminate, malignant), conspicuity and diagnostic confidence. An imaging follow-up (mean interval: 185±92 days) and/-or histopathological specimen served as standards of reference. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for both modalities. Accuracy was determined by calculating the area under the receiver operating characteristic (ROC) curve. Values of conspicuity and diagnostic confidence were compared using Wilcoxon-signed-rank test. Results The standard of reference revealed 113 liver lesions in 26 patients (malignant: n = 45; benign: n = 68). For PET/MRI a higher accuracy (PET/CT: 82.4%; PET/MRI: 96.1%; p<0.001) as well as sensitivity (67.8% vs. 92.2%, p<0.01) and NPV (82.0% vs. 95.1%, p<0.05) were observed. PET/MRI offered higher lesion conspicuity (PET/CT: 2.0±1.1 [median: 2; range 0–3]; PET/MRI: 2.8±0.5 [median: 3; range 0–3]; p<0.001) and diagnostic confidence (PET/CT: 2.0±0.8 [median: 2; range: 1–3]; PET/MRI 2.6±0.6 [median: 3; range: 1–3]; p<0.001). Furthermore, PET/MRI enabled the detection of additional PET-negative metastases (reader 1: 10; reader 2: 12). Conclusions PET/MRI offers higher diagnostic accuracy compared to PET/CT for the detection of liver metastases. PMID:26335246

  18. Single-subject statistical mapping of acute brain hypoxia in the rat following middle cerebral artery occlusion: a microPET study.

    PubMed

    Takasawa, Masashi; Beech, John S; Fryer, Tim D; Jones, P Simon; Ahmed, Tahir; Smith, Rob; Aigbirhio, Franklin I; Baron, Jean-Claude

    2011-06-01

    No study so far has attempted to map the 3D topography of brain hypoxia in the individual rat in vivo following middle cerebral artery occlusion (MCAo). In a previous microPET study, we reported that (18)F-fluoromisonidazole ((18)F-MISO) trapping in the brain after MCAo was specific for the hypoxic viable tissue. Here, we used (18)F-MISO microPET to map the 3D topography of brain hypoxia in the acute stage of permanent distal MCAo in individual spontaneously hypertensive rats. Normal rats were also studied. (18)F-MISO was intravenously injected approximately 1 h after clip placement and PET data were acquired for 2 hours. Animals were sacrificed and the brains harvested 48 h later for infarct mapping using standard histopathology. As expected, continuous (18)F-MISO trapping was found over the affected relative to unaffected and control MCA cortex. Using single-subject voxel-based statistical mapping, tracer accumulation 90-120 min after injection was consistently significantly higher in the anterior MCA cortex (proximal relative to clip site) and gradually decreased towards posterior areas, a pattern consistent with the classic penumbra concept. The data also suggested that (i) a portion of the significant (18)F-MISO trapping area may sit outside the contours of the final infarct despite the permanent MCAo, suggesting that (18)F-MISO may be a marker not only of severe (penumbral) but also of milder (oligemic) hypoxia, and (ii) small portions of the final infarct may not exhibit early tracer trapping, suggesting that by the time the tracer was administered this tissue had already progressed to irreversible damage. This study shows the feasibility of single-subject mapping of brain hypoxia following MCAo in the rat, which has potential applications in pathophysiological investigations. PMID:21335004

  19. Cardiac applications of PET.

    PubMed

    Sarikaya, Ismet

    2015-10-01

    Routine use of cardiac positron emission tomography (PET) applications has been increasing but has not replaced cardiac single-photon emission computerized tomography (SPECT) studies yet. The majority of cardiac PET tracers, with the exception of fluorine-18 fluorodeoxyglucose (18F-FDG), are not widely available, as they require either an onsite cyclotron or a costly generator for their production. 18F-FDG PET imaging has high sensitivity for the detection of hibernating/viable myocardium and has replaced Tl-201 SPECT imaging in centers equipped with a PET/CT camera. PET myocardial perfusion imaging with various tracers such as Rb-82, N-13 ammonia, and O-15 H2O has higher sensitivity and specificity than myocardial perfusion SPECT for the detection of coronary artery disease (CAD). In particular, quantitative PET measurements of myocardial perfusion help identify subclinical coronary stenosis, better define the extent and severity of CAD, and detect ischemia when there is balanced reduction in myocardial perfusion due to three-vessel or main stem CAD. Fusion images of PET perfusion and CT coronary artery calcium scoring or CT coronary angiography provide additional complementary information and improve the detection of CAD. PET studies with novel 18F-labeled perfusion tracers such as 18F-flurpiridaz and 18F-FBnTP have yielded high sensitivity and specificity in the diagnosis of CAD. These tracers are still being tested in humans, and, if approved for clinical use, they will be commercially and widely available. In addition to viability studies, 18F-FDG PET can also be utilized to detect inflammation/infection in various conditions such as endocarditis, sarcoidosis, and atherosclerosis. Some recent series have obtained encouraging results for the detection of endocarditis in patients with intracardiac devices and prosthetic valves. PET tracers for cardiac neuronal imaging, such as C-11 HED, help assess the severity of heart failure and post-transplant cardiac

  20. The ADNI PET Core

    PubMed Central

    Jagust, William J.; Bandy, Dan; Chen, Kewei; Foster, Norman L.; Landau, Susan M.; Mathis, Chester A.; Price, Julie C.; Reiman, Eric M.; Skovronsky, Daniel; Koeppe, Robert A.

    2010-01-01

    Background This is a progress report of the Alzheimer's Disease Neuroimaging Initiative (ADNI) PET Core. Methods The Core has supervised the acquisition, quality control, and analysis of longitudinal [18F]fluorodeoxyglucose PET (FDG-PET) data in approximately half of the ADNI cohort. In an “add on” study, approximately 100 subjects also underwent scanning with [11C]PIB-PET for amyloid imaging. The Core developed quality control procedures and standardized image acquisition by developing an imaging protocol that has been widely adopted in academic and pharmaceutical industry studies. Data processing provides users with scans that have identical orientation and resolution characteristics despite acquisition on multiple scanner models. The Core labs have used a number of different approaches to characterize differences between subject groups (AD, MCI, controls), to examine longitudinal change over time in glucose metabolism and amyloid deposition, and to assess the use of FDG-PET as a potential outcome measure in clinical trials. Results ADNI data indicate that FDG-PET increases statistical power over traditional cognitive measures, might aid subject selection, and could substantially reduce the sample size in a clinical trial. PIB-PET data showed expected group differences, and identified subjects with significant annual increases in amyloid load across the subject groups. The next activities of the PET core in ADNI will entail developing standardized protocols for amyloid imaging using the [18F]-labeled amyloid imaging agent AV45, which can be delivered to virtually all ADNI sites. Conclusions ADNI has demonstrated the feasibility and utility of multicenter PET studies and is helping to clarify the role of biomarkers in the study of aging and dementia. PMID:20451870

  1. Interim fluorine-18 fluorodeoxyglucose PET-computed tomography and cell of origin by immunohistochemistry predicts progression-free and overall survival in diffuse large B-cell lymphoma patients in the rituximab era

    PubMed Central

    Hallack Neto, Abrahão; Siqueira, Sheila; Lage, Luis Alberto de Padua Covas; de Paula, Henrique M.; Coutinho, Arthur M.; Pereira, Juliana

    2016-01-01

    Objective The aim of this study was to analyze the prognostic value of the interim PET (iPET)-computed tomography (CT) (iPET-CT) after two cycles of immunochemotherapy with the R-CHOP protocol in patients with diffuse large B-cell non-Hodgkin lymphoma (DLBCL) treated with a curative intent in combination with the neoplastic cell origin defined by Hans’s immunohistochemstry algorithm followed in a reference center for cancer treatment in Brazil. Materials and methods We prospectively evaluated 147 DLBCL patients treated with R-CHOP-21 to assess the value of the International Prognostic Index, iPET-CT, and cell of origin by immunohistochemistry as prognostic markers in the rituximab era. Fluorine-18 fluorodeoxyglucose PET-CT was performed after two cycles (iPET-CT) and at the end of treatment in 111 patients. Lymphoma cases were categorized into germinal center (GC) and nongerminal center subtypes by immunohistochemistry according to Hans’s algorithm. Results The median age of GC-DLBCL patients (52.7 years) was lower than that of nongerminal center-DLBCL patients (59.4 years) (P=0.021); in addition, it was lower in patients with negative iPET-CT findings (52.7 years) versus positive findings (59.4 years) (P=0.031). The overall survival at 48 months was 100% for iPET-CT-negative GC-DLBCL patients and 61.2% for iPET-CT-positive GC-DLBCL patients (P=0.002). Progression-free survival at 30 months was 100% for iPET-CT-negative GC-DLBCL patients and 60.3% for iPET-CT-positive GC-DLBCL patients (P=0.001). Conclusion We conclude that iPET-CT associated with cell origin identified a very good prognostic group in DLBCL patients treated with R-CHOP. Video Abstract: http://links.lww.com/NMC/A59 PMID:27281359

  2. Healthy Pets and People

    MedlinePlus

    ... Pregnant women should avoid adopting or handling stray cats, especially kittens. They particularly should not clean litter ... may be sick. Many pets, such as dogs, cats, reptiles, rodents, and birds, carry germs that can ...

  3. Pets and Parasites

    MedlinePlus

    ... make me sick? Household pets such as dogs, cats, birds and reptiles can carry diseases or parasites ... might be used as litter boxes by neighborhood cats. Keep your children out of the dirt in ...

  4. Household Hazards to Pets

    MedlinePlus

    ... health by becoming aware of the most common health hazards found in many pet-owning households. Hazards in the Kitchen Foods Many foods are perfectly safe for humans, but could be harmful or potentially deadly to ...

  5. Heart PET scan

    MedlinePlus

    Heart nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... Udelson JE, Dilsizian V, Bonow RO. Nuclear cardiology. In: Mann DL, ... A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, ...

  6. Brain PET scan

    MedlinePlus

    ... tests, such as magnetic resonance imaging ( MRI ) and computed tomography ( CT ) scans only reveal the structure of the ... a PET/CT. Alternative Names ... PT, Rijntjes M, Weiller C. Neuroimaging: Functional neuroimaging. In: Daroff RB, Fenichel GM, Jankovic ...

  7. PET studies in epilepsy

    PubMed Central

    Sarikaya, Ismet

    2015-01-01

    Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. 18Fluoro-2-deoxyglucose (18F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients refractory to medical treatments who have noncontributory EEG and MRI. In addition to localizing epileptogenic focus, FDG-PET provide additional important information on the functional status of the rest of the brain. The main limitation of interictal FDG-PET is that it cannot precisely define the surgical margin as the area of hypometabolism usually extends beyond the epileptogenic zone. Various neurotransmitters (GABA, glutamate, opiates, serotonin, dopamine, acethylcholine, and adenosine) and receptor subtypes are involved in epilepsy. PET receptor imaging studies performed in limited centers help to understand the role of neurotransmitters in epileptogenesis, identify epileptic foci and investigate new treatment approaches. PET receptor imaging studies have demonstrated reduced 11C-flumazenil (GABAA-cBDZ) and 18F-MPPF (5-HT1A serotonin) and increased 11C-cerfentanil (mu opiate) and 11C-MeNTI (delta opiate) bindings in the area of seizure. 11C-flumazenil has been reported to be more sensitive than FDG-PET for identifying epileptic foci. The area of abnormality on GABAAcBDZ and opiate receptor images is usually smaller and more circumscribed than the area of hypometabolism on FDG images. Studies have demonstrated that 11C-alpha-methyl-L-tryptophan PET (to study synthesis of serotonin) can detect the epileptic focus within malformations of cortical development and helps in differentiating epileptogenic from non-epileptogenic tubers in patients with tuberous sclerosis complex

  8. PET/CT Artifacts

    PubMed Central

    Blodgett, Todd M.; Mehta, Ajeet S.; Mehta, Amar S.; Laymon, Charles M.; Carney, Jonathan; Townsend, David W.

    2014-01-01

    There are several artifacts encountered in PET/CT imaging, including attenuation correction (AC) artifacts associated with using CT for attenuation correction. Several artifacts can mimic a 2-deoxy-2-[18F] fluoro-D-glucose (FDG) avid malignant lesions and therefore recognition of these artifacts is clinically relevant. Our goal was to identify and characterize these artifacts and also discuss some protocol variables that may affect image quality in PET/CT. PMID:21237418

  9. Clinical Application of in-room PET for in vivo Treatment Monitoring in Proton Radiotherapy

    PubMed Central

    Min, Chul Hee; Zhu, Xuping; Winey, Brian A.; Grogg, Kira; Testa, Mauro; Fakhri, Georges El; Bortfeld, Thomas R.; Paganetti, Harald; Shih, Helen A.

    2013-01-01

    Purpose/Objective(s) The purpose of this study is to evaluate the potential of using an in-room PET for treatment verification in proton therapy and to derive suitable PET scan times. Materials/Methods Nine patients undergoing passive scattering proton therapy were scanned immediately after treatment with an in-room PET scanner. The scanner was positioned next to the treatment head after treatment. The Monte Carlo (MC) method was employed to reproduce PET activities for each patient. To assess the proton beam range uncertainty we designed a novel concept where the measured PET activity surface distal to the target at the end of range was compared with MC predictions. The repositioning of patients for the PET scan took on average about 2 minutes. The PET images were reconstructed considering varying scan times to test the scan time dependency of the method. Results The measured PET images show overall good spatial correlations with MC predictions. Some discrepancies could be attributed to uncertainties in the local elemental composition and biological washout. For 8 patients treated with a single field, the average range differences between PET measurements and CT-image-based MC results were less than 5 mm (< 3 mm for 6 of 8 patients) and root-mean-square deviations (RMSD) were 4-11 mm with PET-CT image co-registration errors of about 2 mm. Our results also show that a short-length PET scan of 5 minutes can yield similar results compared to a 20 minutes PET scan. Conclusions Our first clinical trials of 9 patients using an in-room PET system demonstrated its potential for in vivo treatment monitoring in proton therapy. For a quantitative range prediction with arbitrary shape of target volume, we suggest employing the distal PET activity surface. PMID:23391817

  10. Pet-related infections.

    PubMed

    Rabinowitz, Peter M; Gordon, Zimra; Odofin, Lynda

    2007-11-01

    Human contact with cats, dogs, and other pets results in several million infections each year in the United States, ranging from self-limited skin conditions to life-threatening systemic illnesses. Toxoplasmosis is one of the most common pet-related parasitic infections. Although toxoplasmosis is usually asymptomatic or mild, it may cause serious congenital infection if a woman is exposed during pregnancy, particularly in the first trimester. Common pet-borne fungal infections include tinea corporis/capitis (ringworm); campylobacteriosis and salmonellosis are among the most common bacterial infections associated with pet ownership. Less commonly, pets can transmit arthropod-borne and viral illnesses (e.g., scabies, rabies). Infection in a pet can provide sentinel warning of local vectors and endemic conditions, such as Lyme disease risk. Treatment is infection-specific, although many infections are self-limited. Prevention involves common sense measures such as adequate hand washing, proper disposal of animal waste, and ensuring that infected animals are diagnosed and treated. Special precautions are indicated for immunocompromised persons. Increased communication between primary care physicians and veterinarians could improve treatment and prevention of these conditions. PMID:18019874

  11. PET/MR Imaging in Vascular Disease: Atherosclerosis and Inflammation.

    PubMed

    Ripa, Rasmus Sejersten; Pedersen, Sune Folke; Kjær, Andreas

    2016-10-01

    For imaging of atherosclerotic disease, lumenography using computed tomography, ultrasonography, or invasive angiography is still the backbone of evaluation. However, these methods are less effective to predict the likelihood of future thromboembolic events caused by vulnerability of plaques. PET and MR imaging have been used separately with success for plaque characterization. Where MR imaging has the ability to reveal plaque composition, PET has the ability to visualize plaque activity. Together this leads to a comprehensive evaluation of plaque vulnerability. In this review, the authors go through data and arguments that support increased use of PET/MR imaging in atherosclerotic imaging. PMID:27593251

  12. [PET in lymphomas: a pattern for the treatment at measure].

    PubMed

    Carreras Delgado, José Luis

    2004-01-01

    Positron Emission Tomography with FDG (PET-FDG) is a molecular diagnostic imaging technique that allows for the detection of tumour lesions based on their increased anaerobic glycolytic metabolism. It is acquiring increasing significance in oncology. The introduction of PET in the field of lymphomas has been slow. The main reasons are: budget limitations, difficulties to perform biopsies in all the lesions, absence of a perfect gold standard and reduced number of publications with appropriate methodological quality. Several papers have appeared in the last 3 years that assess the value of PET-FDG in lymphomas, demonstrating the relationship between the results of PET-FDG and survival (total, disease free, progression free and relapse free) or between results of PET-FDG and relapse average. All of this has great interest in the definition of the most appropriate treatment and especially to decide when it is necessary to continue with a determined treatment or to stop it, or when an inefficient treatment line must be substituted early by another. The main indications are: a. Initial staging. b. Assessment in the middle of the treatment for defining the response and for detecting residual disease. c. To confirm or exclude the doubtful complete remission at the end of the treatment. In these cases CT scan shows a residual mass with response superior to 75%. If PET-FDG is negative, the most probable diagnosis is complete remission. d. In a certain type of lymphoma the situation if the PET-FDG is positive or negative at the end of treatment is very different. A negative PET-FDG can predict longer survival (total, disease free, relapse free, progression free) and a positive PET-FDG can indicate a change in the treatment or the need for more treatment. e. Residual disease evaluation in autologous transplantation. Prognostic utility. f. Variable utility of PET-FDG depending on the type of lymphoma. PMID:15997595

  13. The ADNI PET Core: 2015

    PubMed Central

    Jagust, William J.; Landau, Susan M.; Koeppe, Robert A.; Reiman, Eric M.; Chen, Kewei; Mathis, Chester A.; Price, Julie C.; Foster, Norman L.; Wang, Angela Y.

    2015-01-01

    INTRODUCTION This paper reviews the work done in the ADNI PET core over the past 5 years, largely concerning techniques, methods, and results related to amyloid imaging in ADNI. METHODS The PET Core has utilized [18F]florbetapir routinely on ADNI participants, with over 1600 scans available for download. Four different laboratories are involved in data analysis, and have examined factors such as longitudinal florbetapir analysis, use of FDG-PET in clinical trials, and relationships between different biomarkers and cognition. RESULTS Converging evidence from the PET Core has indicated that cross-sectional and longitudinal florbetapir analyses require different reference regions. Studies have also examined the relationship between florbetapir data obtained immediately after injection, which reflects perfusion, and FDG-PET results. Finally, standardization has included the translation of florbetapir PET data to a centiloid scale. CONCLUSION The PET Core has demonstrated a variety of methods for standardization of biomarkers such as florbetapir PET in a multicenter setting. PMID:26194311

  14. Pet Loss: Implications for Counselors.

    ERIC Educational Resources Information Center

    Sharkin, Bruce S.; Bahrick, Audrey S.

    1990-01-01

    Attempts to increase awareness of counselors about topic of pet loss. Discusses how counselors can be actively involved through practice, consultation, and research to help people deal with emotional impact of pet loss. (Author/NB)

  15. Diagnostic value of SPECT, PET and PET/CT in the diagnosis of coronary artery disease: A systematic review

    PubMed Central

    Al Moudi, M; Sun, Z; Lenzo, N

    2011-01-01

    Purpose: The purpose of the study was to investigate the diagnostic value of SPECT, PET and PET/CT in the diagnosis of coronary artery disease, based on a systematic review. Material and Methods: A search of PubMed/Medline and Sciencedirect databases in the English-language literature published over the last 24 years was performed. Only studies with at least 10 patients comparing SPECT, PET or combined PET/CT with invasive coronary angiography in the diagnosis of coronary artery disease (50% stenosis) were included for analysis. Sensitivities and specificities estimates pooled across studies were analysed using a Chi-square test. Results: Twenty-five studies met the selection criteria and were included for the analysis. Ten studies were performed with SPECT alone; while another six studies were performed with PET alone. Five studies were carried out with both PET and SPECT modalities, and the remaining four studies were investigated with integrated PET-CT. The mean value of sensitivity, specificity and accuracy of these imaging modalities for the diagnosis of coronary artery disease was 82% (95%CI: 76 to 88), 76% (95%CI: 70 to 82) and 83% (95%CI: 77 to 89) for SPECT; 91% (95%CI: 85 to 97), 89% (95%CI: 83 to 95) and 89% (95%CI: 83 to 95) for PET; and 85% (95%CI: 79 to 90), 83% (95%CI: 77 to 89) and 88% (95%CI: 82 to 94) for PET/CT, respectively. The diagnostic accuracy of these imaging modalities was dependent on the radiotracers used in these studies, with ammonia resulting in the highest diagnostic value. Conclusion: Our review shows that PET has high diagnostic value for diagnosing coronary artery disease, and this indicates that it is a valuable technique for both detection and prediction of coronary artery disease. PMID:22287989

  16. Simulation of triple coincidences in PET.

    PubMed

    Cal-González, J; Lage, E; Herranz, E; Vicente, E; Udias, J M; Moore, S C; Park, M-A; Dave, S R; Parot, V; Herraiz, J L

    2015-01-01

    Although current PET scanners are designed and optimized to detect double coincidence events, there is a significant amount of triple coincidences in any PET acquisition. Triple coincidences may arise from causes such as: inter-detector scatter (IDS), random triple interactions (RT), or the detection of prompt gamma rays in coincidence with annihilation photons when non-pure positron-emitting radionuclides are used (β(+)γ events). Depending on the data acquisition settings of the PET scanner, these triple events are discarded or processed as a set of double coincidences if the energy of the three detected events is within the scanner's energy window. This latter option introduces noise in the data, as at most, only one of the possible lines-of-response defined by triple interactions corresponds to the line along which the decay occurred. Several novel works have pointed out the possibility of using triple events to increase the sensitivity of PET scanners or to expand PET imaging capabilities by allowing differentiation between radiotracers labeled with non-pure and pure positron-emitting radionuclides. In this work, we extended the Monte Carlo simulator PeneloPET to assess the proportion of triple coincidences in PET acquisitions and to evaluate their possible applications. We validated the results of the simulator against experimental data acquired with a modified version of a commercial preclinical PET/CT scanner, which was enabled to acquire and process triple-coincidence events. We used as figures of merit the energy spectra for double and triple coincidences and the triples-to-doubles ratio for different energy windows and radionuclides. After validation, the simulator was used to predict the relative quantity of triple-coincidence events in two clinical scanners assuming different acquisition settings. Good agreement between simulations and preclinical experiments was found, with differences below 10% for most of the observables considered. For clinical

  17. An Educational PET Camera Model

    ERIC Educational Resources Information Center

    Johansson, K. E.; Nilsson, Ch.; Tegner, P. E.

    2006-01-01

    Positron emission tomography (PET) cameras are now in widespread use in hospitals. A model of a PET camera has been installed in Stockholm House of Science and is used to explain the principles of PET to school pupils as described here.

  18. PET/CT imaging artifacts.

    PubMed

    Sureshbabu, Waheeda; Mawlawi, Osama

    2005-09-01

    The purpose of this paper is to introduce the principles of PET/CT imaging and describe the artifacts associated with it. PET/CT is a new imaging modality that integrates functional (PET) and structural (CT) information into a single scanning session, allowing excellent fusion of the PET and CT images and thus improving lesion localization and interpretation accuracy. Moreover, the CT data can also be used for attenuation correction, ultimately leading to high patient throughput. These combined advantages have rendered PET/CT a preferred imaging modality over dedicated PET. Although PET/CT imaging offers many advantages, this dual-modality imaging also poses some challenges. CT-based attenuation correction can induce artifacts and quantitative errors that can affect the PET emission images. For instance, the use of contrast medium and the presence of metallic implants can be associated with focal radiotracer uptake. Furthermore, the patient's breathing can introduce mismatches between the CT attenuation map and the PET emission data, and the discrepancy between the CT and PET fields of view can lead to truncation artifacts. After reading this article, the technologist should be able to describe the principles of PET/CT imaging, identify at least 3 types of image artifacts, and describe the differences between PET/CT artifacts of different causes: metallic implants, respiratory motion, contrast medium, and truncation. PMID:16145223

  19. Translational Coronary Atherosclerosis Imaging with PET.

    PubMed

    Adamson, Philip D; Newby, David E; Dweck, Marc R

    2016-02-01

    Although still in its infancy, coronary atherosclerosis imaging with PET holds promise in improving understanding of the pathophysiologic processes that underlie plaque progression and adverse cardiovascular events. Fludeoxyglucose F 18 offers the potential to measure inflammatory activity within the plaque itself whereas fluoride F 18 allows detection of microcalcification, both of which are key characteristics of plaques at risk of rupture. Further work is required to improve these imaging techniques and to assess their ability to predict cardiac events prospectively. PMID:26590788

  20. [Technical Approaches for Quantitative Treatment Responses Using 18F-FDG PET].

    PubMed

    Miwa, Kenta; Miyaji, Noriaki; Umeda, Takuro; Murata, Taisuke; Wagatsuma, Kei; Sasaki, Masayuki

    2015-01-01

    Quantitative assessment of 18F-FDG PET can predict treatment responses or outcomes. Here, I briefly describe some world trends in standardizing PET images for image-based assessments of treatment responses, followed by present and future strategies for defining the optimal acquisition conditions for quantitative PET imaging. Finally, information is provided about new technical approaches to improving the quantitation of semi-quantitative indexes such as point spread function, time-of-flight and respiratory gating. PMID:26753394

  1. PET in Cerebrovascular Disease

    PubMed Central

    Powers, William J.; Zazulia, Allyson R.

    2010-01-01

    SYNOPSIS Investigation of the interplay between the cerebral circulation and brain cellular function is fundamental to understanding both the pathophysiology and treatment of stroke. Currently, PET is the only technique that provides accurate, quantitative in vivo regional measurements of both cerebral circulation and cellular metabolism in human subjects. We review normal human cerebral blood flow and metabolism and human PET studies of ischemic stroke, carotid artery disease, vascular dementia, intracerebral hemorrhage and aneurysmal subarachnoid hemorrhage and discuss how these studies have added to our understanding of the pathophysiology of human cerebrovascular disease. PMID:20543975

  2. Childhood pet ownership, attachment to pets, and subsequent meat avoidance. The mediating role of empathy toward animals.

    PubMed

    Rothgerber, Hank; Mican, Frances

    2014-08-01

    Researchers studying childhood pet ownership outcomes do not typically focus on measures of adult diet, and those studying the psychology of meat consumption do not normally consider early experiences with companion animals. The present research sought to integrate these two areas by examining relationships between childhood pet ownership, pet attachment, empathy toward animals, belief in human-animal similarity, meat avoidance, and justifications for eating meat. Results from 273 individuals responding to a survey on an internet platform revealed that participants with greater childhood attachment to a pet reported greater meat avoidance as adults, an effect that disappeared when controlling for animal empathy. Greater childhood pet attachment was also related to the use of indirect, apologetic justifications for meat consumption, and this effect too, was mediated by empathy toward animals. Child pet ownership itself predicted views toward animals but not dietary behavior or meat-eating justifications. The authors propose a sequence of events by which greater childhood pet attachment leads to increased meat avoidance, focusing on the central role played by empathy toward animals. PMID:24704704

  3. [Pets, veterinarians, and multicultural society].

    PubMed

    Klumpers, M; Endenburg, N

    2009-01-15

    Dutch society comprises a growing percentage of non-Western ethnic minority groups. Little is known about pet ownership among these groups. This study explores some aspects of pet ownership, and the position of veterinarians, among the four largest non-Western ethnic minority groups in the Netherlands. Information was gathered through street interviews with people from a Moroccan, Turkish, Surinamese, or Antillean (including Aruban) background. Five hundred people where interviewed, including 41 pet owners. Results showed that people from non-Western ethnic minorities kept pets less often than Dutch people, with fish and birds being the most frequently kept pets. The number of visits to the veterinary clinic was comparable to that of Dutch pet owners; however, reasons given for the last visit were different. People from non-Western ethnic minorities mostly visited a veterinarian if their pet was ill whereas Dutch people visited the veterinarian if their pet needed to be vaccinated. People from non-Western ethnic minorities were positive about veterinarians, considering that they had sufficient knowledge about and concern for their pets. Moreover, veterinarians were trusted and provided understandable information--the respondents felt that they could go to their veterinarian with any question or problem regarding their pets. Although most respondents considered a visit to the veterinarian expensive, they were more than willing to invest in their pet's health. PMID:19235301

  4. Monitoring proton radiation therapy with in-room PET imaging

    PubMed Central

    Zhu, Xuping; España, Samuel; Daartz, Juliane; Liebsch, Norbert; Ouyang, Jinsong; Paganetti, Harald; Bortfeld, Thomas R; El Fakhri, Georges

    2011-01-01

    Purpose We used a mobile PET scanner positioned within the proton therapy treatment room to study the feasibility of proton range verification with an in-room, stand-alone PET system, and compared with off-line equivalent studies. Methods and materials Two subjects with adenoid cystic carcinoma were enrolled into a pilot study in which in-room PET scans were acquired in list-mode after a routine fractionated treatment session. The list-mode PET data were reconstructed with different time schemes to generate in-room short, in-room long and off-line equivalent (by skipping coincidences from the first 15 minutes during the list-mode reconstruction) PET images for comparison in activity distribution patterns. A phantom study was followed to evaluate the accuracy of range verification for different reconstruction time schemes quantitatively. Results The in-room PET has a higher sensitivity compared to the off-line modality so that the PET acquisition time can be greatly reduced from 30 min to <5 min. Features in deep-site, soft-tissue regions were better retained with in-room short PET acquisitions because of the collection of 15O component and lower biological washout. For soft tissue-equivalent material, the distal fall-off edge of an in-room short acquisition is deeper compared to an off-line equivalent scan, indicating a better coverage of the high-dose end of the beam. Conclusions In-room PET is a promising low cost, high sensitivity modality for the in vivo verification of proton therapy. Better accuracy in Monte Carlo predictions, especially for biological decay modeling, is necessary. PMID:21677366

  5. MR/PET or PET/MRI: does it matter?

    PubMed

    Beyer, Thomas; Moser, Ewald

    2013-02-01

    After the very successful clinical introduction of combined PET/CT imaging a decade ago, a hardware combination of PET and MR is following suit. Today, three different approaches towards integrated PET/MR have been proposed: (1) a triple-modality system with a 3T MRI and a time-of-flight PET/CT installed in adjacent rooms, (2) a tandem system with a 3T MRI and a time-of-flight PET/CT in a co-planar installation with a joint patient handling system, and (3) a fully-integrated system with a whole-body PET system mounted inside a 3T MRI system. This special issue of MAGMA brings together contributions from key experts in the field of PET/MR, PET/CT and CT. The various papers share the author's perspectives on the state-of-the-art PET/MR imaging with any of the three approaches mentioned above. In addition to several reviews discussing advantages and challenges of combining PET and MRI for clinical diagnostics, first clinical data are also presented. We expect this special issue to nurture future improvements in hardware, clinical protocols, and efficient post-processing strategies to further assess the diagnostic value of combined PET/MR imaging. It remains to be seen whether a so-called "killer application" for PET/MRI will surface. In that case PET/MR is likely to excel in pre-clinical and selected research applications for now. This special issue helps the readers to stay on track of this exciting development. PMID:23385880

  6. Motion correction options in PET/MRI.

    PubMed

    Catana, Ciprian

    2015-05-01

    Subject motion is unavoidable in clinical and research imaging studies. Breathing is the most important source of motion in whole-body PET and MRI studies, affecting not only thoracic organs but also those in the upper and even lower abdomen. The motion related to the pumping action of the heart is obviously relevant in high-resolution cardiac studies. These two sources of motion are periodic and predictable, at least to a first approximation, which means certain techniques can be used to control the motion (eg, by acquiring the data when the organ of interest is relatively at rest). Additionally, nonperiodic and unpredictable motion can also occur during the scan. One obvious limitation of methods relying on external devices (eg, respiratory bellows or the electrocardiogram signal to monitor the respiratory or cardiac cycle, respectively) to trigger or gate the data acquisition is that the complex motion of internal organs cannot be fully characterized. However, detailed information can be obtained using either the PET or MRI data (or both) allowing the more complete characterization of the motion field so that a motion model can be built. Such a model and the information derived from simple external devices can be used to minimize the effects of motion on the collected data. In the ideal case, all the events recorded during the PET scan would be used to generate a motion-free or corrected PET image. The detailed motion field can be used for this purpose by applying it to the PET data before, during, or after the image reconstruction. Integrating all these methods for motion control, characterization, and correction into a workflow that can be used for routine clinical studies is challenging but could potentially be extremely valuable given the improvement in image quality and reduction of motion-related image artifacts. PMID:25841276

  7. MOTION CORRECTION OPTIONS IN PET/MRI

    PubMed Central

    Catana, Ciprian

    2015-01-01

    Subject motion is unavoidable in clinical and research imaging studies. Breathing is the most important source of motion in whole-body positron emission tomography (PET) and magnetic resonance imaging (MRI) studies, affecting not only thoracic organs but also those in the upper and even lower abdomen. The motion related to the pumping action of the heart is obviously relevant in high-resolution cardiac studies. These two sources of motion are periodic and predictable, at least to a first approximation, which means certain techniques can be used to control the motion (e.g. by acquiring the data when the organ of interest is relatively at rest). Additionally, non-periodic and unpredictable motion can also occur during the scan. One obvious limitation of methods relying on external devices (e.g. respiratory bellows or the ECG signal to monitor the respiratory or cardiac cycle, respectively) to trigger or gate the data acquisition is that the complex motion of internal organs cannot be fully characterized. However, detailed information can be obtained either using the PET or MRI data (or both) allowing the more complete characterization of the motion field so that a motion model can be built. Such a model and the information derived from simple external devices can be used to minimize the effects of motion on the collected data. In the ideal case, all the events recorded during the PET scan would be used to generate a motion free/corrected PET image. The detailed motion field can be used for this purpose by applying it to the PET data before, during or after the image reconstruction. Integrating all these methods for motion control, characterization and correction into a workflow that can be used for routine clinical studies is challenging but could potentially be extremely valuable given the improvement in image quality and reduction of motion-related image artifacts. PMID:25841276

  8. 24 CFR 960.707 - Pet ownership.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Pet ownership. 960.707 Section 960... ADMISSION TO, AND OCCUPANCY OF, PUBLIC HOUSING Pet Ownership in Public Housing § 960.707 Pet ownership. (a..., may own one or more common household pets or have one or more common household pets present in...

  9. 24 CFR 960.707 - Pet ownership.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Pet ownership. 960.707 Section 960... ADMISSION TO, AND OCCUPANCY OF, PUBLIC HOUSING Pet Ownership in Public Housing § 960.707 Pet ownership. (a..., may own one or more common household pets or have one or more common household pets present in...

  10. Talking with Children about Furry Classroom Pets.

    ERIC Educational Resources Information Center

    Texas Child Care, 1994

    1994-01-01

    Notes that rodents and rabbits share many characteristics that make them suitable classroom pets and gives background information on rabbits, guinea pigs, hamsters, and gerbils. Offers advice on buying a classroom pet, the pet's home, feeding, helping the children handle the pet, and pet health and family planning. (TJQ)

  11. [The PET, Past and Future].

    PubMed

    Fujii, Hirofumi

    2015-01-01

    Positron emission tomography (PET) is a unique nuclear medicine test using positron emitters such as 18F and 11C. In PET tests, various kinds of functional aspects of human bodies can be evaluated by using compounds labeled by these positron emitters. Recently, combined scanners of PET and anatomical imaging modalities such as CT and MRI have been developed and functional information with anatomical location can be easily obtained, increasing the usefulness of PET tests. PET tests are now essential imaging tools to diagnose various kinds of disease with functional abnormalities. In the field of oncology, 18F-fluorodeoxy glucose PET tests are routinely used in clinical practice under health insurance. In the field of neurology, PET tests are actively used to investigate cerebral function by labeled neurotransmitters and so on. Currently, brain PET tests to detect beta-amyloid are applied to the diagnosis of dementia. In the field of cardiology, cardiac perfusion and myocardial metabolism are quantitatively measured by using PET and obtained results have successfully revealed the pathogenesis of intractable cardiac diseases. Future technical advances will enhance the usefulness of PET tests more and more. PMID:26753390

  12. A Recommendation on How to Analyze In-Room PET for In Vivo Proton Range Verification Using a Distal PET Surface Method

    PubMed Central

    Min, Chul Hee; Zhu, Xuping; Grogg, Kira; El Fakhri, Georges; Winey, Brian; Paganetti, Harald

    2016-01-01

    We describe the rationale and implementation of a method for analyzing in-room positron emission tomography (PET) data to verify the proton beam range. The method is based on analyzing distal PET surfaces after passive scattering proton beam delivery. Typically in vivo range verification is done by comparing measured and predicted PET distribution for a single activity level at a selected activity line along the beam passage. In the method presented here, we suggest using a middle point method based on dual PET activity levels to minimize the uncertainty due to local variations in the PET activity. Furthermore, we introduce 2-dimensional (2D) PET activity level surfaces based on 3-dimensional maps of the PET activities along the beam passage. This allows determining not only average range differences but also range difference distributions as well as root mean square deviations (RMSDs) for a more comprehensive range analysis. The method is demonstrated using data from 8 patients who were scanned with an in-room PET scanner. For each of the 8 patients, the average range difference was less than 5 mm and the RMSD was 4 to 11 mm between the measured and simulated PET activity level surfaces for single-field treatments. An ongoing protocol at our institution allows the use of a single field for patients being imaged for the PET range verification study at 1 fraction during their treatment course. Visualizing the range difference distributions using the PET surfaces offers a convenient visual verification of range uncertainties in 2D. Using the distal activity level surfaces of simulated and measured PET distributions at the middle of 25% and 50% activity level is a robust method for in vivo range verification. PMID:25246517

  13. A Recommendation on How to Analyze In-Room PET for In Vivo Proton Range Verification Using a Distal PET Surface Method.

    PubMed

    Min, Chul Hee; Zhu, Xuping; Grogg, Kira; El Fakhri, Georges; Winey, Brian; Paganetti, Harald

    2015-06-01

    We describe the rationale and implementation of a method for analyzing in-room positron emission tomography (PET) data to verify the proton beam range. The method is based on analyzing distal PET surfaces after passive scattering proton beam delivery. Typically in vivo range verification is done by comparing measured and predicted PET distribution for a single activity level at a selected activity line along the beam passage. In the method presented here, we suggest using a middle point method based on dual PET activity levels to minimize the uncertainty due to local variations in the PET activity. Furthermore, we introduce 2-dimensional (2D) PET activity level surfaces based on 3-dimensional maps of the PET activities along the beam passage. This allows determining not only average range differences but also range difference distributions as well as root mean square deviations (RMSDs) for a more comprehensive range analysis. The method is demonstrated using data from 8 patients who were scanned with an in-room PET scanner. For each of the 8 patients, the average range difference was less than 5 mm and the RMSD was 4 to 11 mm between the measured and simulated PET activity level surfaces for single-field treatments. An ongoing protocol at our institution allows the use of a single field for patients being imaged for the PET range verification study at 1 fraction during their treatment course. Visualizing the range difference distributions using the PET surfaces offers a convenient visual verification of range uncertainties in 2D. Using the distal activity level surfaces of simulated and measured PET distributions at the middle of 25% and 50% activity level is a robust method for in vivo range verification. PMID:25246517

  14. Progress reported in PET recycling

    SciTech Connect

    Not Available

    1989-06-01

    The Goodyear Polyester Division has demonstrated its ability to break down polyethylene terephthalate (PET) from recycled plastic soft drink bottles and remanufacture the material into PET suitable for containers. Most people are familiar with PET in the form of lightweight, shatter resistant beverage bottles. About 20 percent of these beverage containers currently are being recycled. The recycled PET is currently used in many applications such as carpeting, pillow stuffing, sleeping bag filling, insulation for water heaters and non-food containers. This is the first step of Goodyear's increased efforts to recycle PET from containers into a material suitable for food packing. The project is extremely complex, involving sophisticated understanding of the chemical reactions involved, PET production and the technology testing protocols necessary to design a process that addresses all the technical, safety, and regulatory concerns. The research conducted so far indicated that additional processing beyond simply cleaning the shredded material, called flake, will be required to assure a quality polymer.

  15. RPC PET: Status and perspectives

    NASA Astrophysics Data System (ADS)

    Couceiro, M.; Blanco, A.; Ferreira, Nuno C.; Ferreira Marques, R.; Fonte, P.; Lopes, L.

    2007-10-01

    The status of the resistive plate chamber (RPC)-PET technology for small animals is briefly reviewed and its sensitivity performance for human PET studied through Monte-Carlo simulations. The cost-effectiveness of these detectors and their very good timing characteristics open the possibility to build affordable Time of Flight (TOF)-PET systems with very large fields of view. Simulations suggest that the sensitivity of such systems for human whole-body screening, under reasonable assumptions, may exceed the present crystal-based PET technology by a factor up to 20.

  16. Extended suicide with a pet.

    PubMed

    Cooke, Brian K

    2013-01-01

    The combination of the killing of a pet and a suicide is a perplexing scenario that is largely unexplored in the literature. Many forensic psychiatrists and psychologists may be unaccustomed to considering the significance of the killing of a pet. The subject is important, however, because many people regard their pets as members of their family. A case is presented of a woman who killed her pet dog and herself by carbon monoxide poisoning. The purpose of this article is to provide an initial exploration of the topic of extended suicide with a pet. Forensic mental health evaluations may have a role in understanding the etiology of this event and in opining as to the culpability of individuals who attempt to or successfully kill a pet and then commit suicide. Because the scientific literature is lacking, there is a need to understand this act from a variety of perspectives. First, a social and anthropological perspective will be presented that summarizes the history of the practice of killing of one's pet, with a focus on the ancient Egyptians. A clinical context will examine what relationship animals have to mental illness. A vast body of existing scientific data showing the relevance of human attachment to pets suggests that conclusions from the phenomena of homicide-suicide and filicide-suicide are applicable to extended suicide with a pet. Finally, recommendations will be proposed for both clinical and forensic psychiatrists faced with similar cases. PMID:24051598

  17. Get Set for a Pet.

    ERIC Educational Resources Information Center

    DeRosa, Bill

    1987-01-01

    Describes a game in which students deal with some of the factors involved in being a responsible pet owner. Includes a list of the materials needed for the game and provides the game board and the game pieces, along with a fold-out poster about neutering and spaying pets. (TW)

  18. PET/CT: fundamental principles.

    PubMed

    Seemann, Marcus D

    2004-05-28

    Positron emission tomography (PET) facilitates the evaluation of metabolic and molecular characteristics of a wide variety of cancers, but is limited in its ability to visualize anatomical structures. Computed tomography (CT) facilitates the evaluation of anatomical structures of cancers, but can not visualize their metabolic and molecular aspects. Therefore, the combination of PET and CT provides the ability to accurately register metabolic and molecular aspects of disease with anatomical findings, adding further information to the diagnosis and staging of tumors. The recent generation of high performance PET/CT scanners combines a state of the art full-ring 3D PET scanner and a high-end 16-slice CT scanner. In PET/CT scanners, a CT examination is used for attenuation correction of PET images rather than standard transmission scanning using superset 68 Ge sources. This reduces the examination time, but metallic objects and contrast agents that alter the CT image quality and quantitative measurements of standardized uptake values (SUV) may lead to artifacts in the PET images. Hybrid PET/CT imaging will be very important in oncological applications in the decades to come, and possibly for use in cancer screening and cardiac imaging. PMID:15257877

  19. Meet the Alpha-Pets.

    ERIC Educational Resources Information Center

    Zitlaw, Jo Ann Bruce; Frank, Cheryl Standish

    1985-01-01

    "Alpha-Pets" are the focal point of an integrated, multidisciplinary curriculum. Each pet is featured for a week in a vocabulary-rich story and introduces related activities beginning with the featured letter, such as the four food groups during Freddie Fish's week or universe during Ulysses Unicorn's week. (MT)

  20. Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy.

    PubMed

    Gianoli, Chiara; Kurz, Christopher; Riboldi, Marco; Bauer, Julia; Fontana, Giulia; Baroni, Guido; Debus, Jürgen; Parodi, Katia

    2016-06-01

    A clinical trial named PROMETHEUS is currently ongoing for inoperable hepatocellular carcinoma (HCC) at the Heidelberg Ion Beam Therapy Center (HIT, Germany). In this framework, 4D PET-CT datasets are acquired shortly after the therapeutic treatment to compare the irradiation induced PET image with a Monte Carlo PET prediction resulting from the simulation of treatment delivery. The extremely low count statistics of this measured PET image represents a major limitation of this technique, especially in presence of target motion. The purpose of the study is to investigate two different 4D PET motion compensation strategies towards the recovery of the whole count statistics for improved image quality of the 4D PET-CT datasets for PET-based treatment verification. The well-known 4D-MLEM reconstruction algorithm, embedding the motion compensation in the reconstruction process of 4D PET sinograms, was compared to a recently proposed pre-reconstruction motion compensation strategy, which operates in sinogram domain by applying the motion compensation to the 4D PET sinograms. With reference to phantom and patient datasets, advantages and drawbacks of the two 4D PET motion compensation strategies were identified. The 4D-MLEM algorithm was strongly affected by inverse inconsistency of the motion model but demonstrated the capability to mitigate the noise-break-up effects. Conversely, the pre-reconstruction warping showed less sensitivity to inverse inconsistency but also more noise in the reconstructed images. The comparison was performed by relying on quantification of PET activity and ion range difference, typically yielding similar results. The study demonstrated that treatment verification of moving targets could be accomplished by relying on the whole count statistics image quality, as obtained from the application of 4D PET motion compensation strategies. In particular, the pre-reconstruction warping was shown to represent a promising choice when combined with intra

  1. Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy

    NASA Astrophysics Data System (ADS)

    Gianoli, Chiara; Kurz, Christopher; Riboldi, Marco; Bauer, Julia; Fontana, Giulia; Baroni, Guido; Debus, Jürgen; Parodi, Katia

    2016-06-01

    A clinical trial named PROMETHEUS is currently ongoing for inoperable hepatocellular carcinoma (HCC) at the Heidelberg Ion Beam Therapy Center (HIT, Germany). In this framework, 4D PET-CT datasets are acquired shortly after the therapeutic treatment to compare the irradiation induced PET image with a Monte Carlo PET prediction resulting from the simulation of treatment delivery. The extremely low count statistics of this measured PET image represents a major limitation of this technique, especially in presence of target motion. The purpose of the study is to investigate two different 4D PET motion compensation strategies towards the recovery of the whole count statistics for improved image quality of the 4D PET-CT datasets for PET-based treatment verification. The well-known 4D-MLEM reconstruction algorithm, embedding the motion compensation in the reconstruction process of 4D PET sinograms, was compared to a recently proposed pre-reconstruction motion compensation strategy, which operates in sinogram domain by applying the motion compensation to the 4D PET sinograms. With reference to phantom and patient datasets, advantages and drawbacks of the two 4D PET motion compensation strategies were identified. The 4D-MLEM algorithm was strongly affected by inverse inconsistency of the motion model but demonstrated the capability to mitigate the noise-break-up effects. Conversely, the pre-reconstruction warping showed less sensitivity to inverse inconsistency but also more noise in the reconstructed images. The comparison was performed by relying on quantification of PET activity and ion range difference, typically yielding similar results. The study demonstrated that treatment verification of moving targets could be accomplished by relying on the whole count statistics image quality, as obtained from the application of 4D PET motion compensation strategies. In particular, the pre-reconstruction warping was shown to represent a promising choice when combined with intra

  2. Recent development in PET instrumentation.

    PubMed

    Peng, By Hao; Levin, Craig S

    2010-09-01

    Positron emission tomography (PET) is used in the clinic and in vivo small animal research to study molecular processes associated with diseases such as cancer, heart disease, and neurological disorders, and to guide the discovery and development of new treatments. This paper reviews current challenges of advancing PET technology and some of newly developed PET detectors and systems. The paper focuses on four aspects of PET instrumentation: high photon detection sensitivity; improved spatial resolution; depth-of-interaction (DOI) resolution and time-of-flight (TOF). Improved system geometry, novel non-scintillator based detectors, and tapered scintillation crystal arrays are able to enhance the photon detection sensitivity of a PET system. Several challenges for achieving high resolution with standard scintillator-based PET detectors are discussed. Novel detectors with 3-D positioning capability have great potential to be deployed in PET for achieving spatial resolution better than 1 mm, such as cadmium-zinc-telluride (CZT) and position-sensitive avalanche photodiodes (PSAPDs). DOI capability enables a PET system to mitigate parallax error and achieve uniform spatial resolution across the field-of-view (FOV). Six common DOI designs, as well as advantages and limitations of each design, are discussed. The availability of fast scintillation crystals such as LaBr(3), and the silicon photomultiplier (SiPM) greatly advances TOF-PET development. Recent instrumentation and initial results of clinical trials are briefly presented. If successful, these technology advances, together with new probe molecules, will substantially enhance the molecular sensitivity of PET and thus increase its role in preclinical and clinical research as well as evaluating and managing disease in the clinic. PMID:20497121

  3. Openability of soft drinks PET packagings.

    PubMed

    Silva, Danilo Corrêa; Paschoarelli, Luis Carlos; da Silva, José Carlos Plácido

    2012-01-01

    Studies on packaging accessibility are still incipient in Brazil. Many of these packagings can represent a challenge to users, whether due to non-informative labels, tricky tabs or seals, or even those that need strength to open. This paper brings a simple test to determine the necessary torque force to open PET bottles, and to predict the amount of users that could not open it. The findings suggest that a considerable amount of users could not open it or would have some difficulties to exert the necessary force. PMID:22316905

  4. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  5. 36 CFR 1002.15 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Pets. 1002.15 Section 1002.15....15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public building, public... possession of pets by the Board. This paragraph shall not apply to guide dogs accompanying visually...

  6. 36 CFR 2.15 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Pets. 2.15 Section 2.15 Parks... USE AND RECREATION § 2.15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public... area closed to the possession of pets by the superintendent. This subparagraph shall not apply to...

  7. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  8. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  9. 36 CFR 2.15 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Pets. 2.15 Section 2.15 Parks... USE AND RECREATION § 2.15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public... area closed to the possession of pets by the superintendent. This subparagraph shall not apply to...

  10. 36 CFR 2.15 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Pets. 2.15 Section 2.15 Parks... USE AND RECREATION § 2.15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public... area closed to the possession of pets by the superintendent. This subparagraph shall not apply to...

  11. 36 CFR 1002.15 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Pets. 1002.15 Section 1002.15....15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public building, public... possession of pets by the Board. This paragraph shall not apply to guide dogs accompanying visually...

  12. 36 CFR 1002.15 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Pets. 1002.15 Section 1002.15....15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public building, public... possession of pets by the Board. This paragraph shall not apply to guide dogs accompanying visually...

  13. 36 CFR 1002.15 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Pets. 1002.15 Section 1002.15....15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public building, public... possession of pets by the Board. This paragraph shall not apply to guide dogs accompanying visually...

  14. 36 CFR 2.15 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Pets. 2.15 Section 2.15 Parks... USE AND RECREATION § 2.15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public... area closed to the possession of pets by the superintendent. This subparagraph shall not apply to...

  15. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  16. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  17. Evaluation of Tumor-associated Stroma and Its Relationship with Tumor Hypoxia Using Dynamic Contrast-enhanced CT and (18)F Misonidazole PET in Murine Tumor Models.

    PubMed

    Koyasu, Sho; Tsuji, Yoshihisa; Harada, Hiroshi; Nakamoto, Yuji; Nobashi, Tomomi; Kimura, Hiroyuki; Sano, Kohei; Koizumi, Koji; Hamaji, Masatsugu; Togashi, Kaori

    2016-03-01

    Purpose To determine the relationship between the fractional interstitial volume (Fis), as calculated at dynamic contrast material-enhanced (DCE) computed tomography (CT), and tumor-associated stroma and to analyze its spatial relationship with tumor hypoxia in several xenograft tumor models. Materials and Methods All animal experiments were approved by the animal research committee. Mice with three different xenograft tumors (U251, CFPAC-1, and BxPC-3; n = 6, n = 8, and n = 6, respectively) underwent DCE CT then hypoxia imaging with fluorine 18 ((18)F) fluoromisonidazole (FMISO) positron emission tomography (PET) within 24 hours. Immunohistochemical analysis was performed in harvested tumors to detect hypoxia markers and to quantify microvascular and stromal density. Two DCE CT parameters (amount of interstitial space associated with the amount of stroma [Fis] and flow velocity [Fv]) were identified and quantitatively validated by using immunohistochemistry. FMISO uptake within the tumor was also assessed in relation to DCE CT parameters. Imaging and immunohistochemical parameters were assessed by using the Kruskal-Wallis test, Wilcoxon rank-sum test with Bonferroni correction, and Pearson correlation coefficient. Results Almost no α-smooth muscle actin-positive cells were found in the U251 xenograft, while abundant stroma was found in the entire BxPC-3 xenograft and in the periphery of the CFPAC-1 xenograft. Quantitative analysis showed a significant correlation (R = 0.83, P < .0001) between Fis and stromal density. FMISO uptake had a negative correlation with Fis (R = -0.58, P < .0001) and Fv (R = -0.53, P < .0001). Conclusion DCE CT can be used to quantify parameters associated with tumor-associated stroma. Tumor hypoxia was Complementarily localized in tumor-associated stroma in these models. (©) RSNA, 2015 Online supplemental material is available for this article. PMID:26393963

  18. Dynamic-compliance and viscosity of PET and PEN

    NASA Astrophysics Data System (ADS)

    Weick, Brian L.

    2016-05-01

    Complex dynamic-compliance and in-phase dynamic-viscosity data are presented and analyzed for PET and PEN advanced polyester substrates used for magnetic tapes. Frequency-temperature superposition is used to predict long-term behavior. Temperature and frequency ranges for the primary glass transition and secondary transitions are discussed and compared for PET and PEN. Shift factors from frequency-temperature superposition are used to determine activation energies for the transitions, and WLF parameters are determined for the polyester substrates.

  19. Understanding regulations affecting pet foods.

    PubMed

    Dzanis, David A

    2008-08-01

    In the United States, pet foods are subject to regulation at both the federal and the state levels. The US Food and Drug Administration has jurisdiction over all animal feeds (including pet foods, treats, chews, supplements, and ingredients) in interstate commerce, which includes imported products. Many states adopt and enforce at least in part the Association of American Feed Control Officials Model Bill and Model Regulations for Pet Food and Specialty Pet Food. Thus, all pet foods in multi-state distribution are subject to a host of labeling requirements covering aspects such as product names, ingredient lists, nutrient content guarantees, and nutritional adequacy statements. Ingredients must be GRAS (generally recognized as safe) substances, approved food additives, or defined by Association of American Feed Control Officials for their intended use. Pet food labels may not bear claims that are false or misleading or that state or imply use for the treatment or prevention of disease. Pet foods that are found to be adulterated or misbranded may be subject to seizure or other enforcement actions. PMID:18656837

  20. PET Imaging of Tau Deposition in the Aging Human Brain.

    PubMed

    Schöll, Michael; Lockhart, Samuel N; Schonhaut, Daniel R; O'Neil, James P; Janabi, Mustafa; Ossenkoppele, Rik; Baker, Suzanne L; Vogel, Jacob W; Faria, Jamie; Schwimmer, Henry D; Rabinovici, Gil D; Jagust, William J

    2016-03-01

    Tau pathology is a hallmark of Alzheimer's disease (AD) but also occurs in normal cognitive aging. Using the tau PET agent (18)F-AV-1451, we examined retention patterns in cognitively normal older people in relation to young controls and AD patients. Age and β-amyloid (measured using PiB PET) were differentially associated with tau tracer retention in healthy aging. Older age was related to increased tracer retention in regions of the medial temporal lobe, which predicted worse episodic memory performance. PET detection of tau in other isocortical regions required the presence of cortical β-amyloid and was associated with decline in global cognition. Furthermore, patterns of tracer retention corresponded well with Braak staging of neurofibrillary tau pathology. The present study defined patterns of tau tracer retention in normal aging in relation to age, cognition, and β-amyloid deposition. PMID:26938442

  1. SU-E-J-222: Evaluation of Deformable Registration of PET/CT Images for Cervical Cancer Brachytherapy

    SciTech Connect

    Liao, Y; Turian, J; Templeton, A; Kiel, K; Chu, J; Kadir, T

    2014-06-01

    Purpose: PET/CT provides important functional information for radiotherapy targeting of cervical cancer. However, repeated PET/CT procedures for external beam and subsequent brachytherapy expose patients to additional radiation and are not cost effective. Our goal is to investigate the possibility of propagating PET-active volumes for brachytherapy procedures through deformable image registration (DIR) of earlier PET/CT and ultimately to minimize the number of PET/CT image sessions required. Methods: Nine cervical cancer patients each received their brachytherapy preplanning PET/CT at the end of EBRT with a Syed template in place. The planning PET/CT was acquired on the day of brachytherapy treatment with the actual applicator (Syed or Tandem and Ring) and rigidly registered. The PET/CT images were then deformably registered creating a third (deformed) image set for target prediction. Regions of interest with standardized uptake values (SUV) greater than 65% of maximum SUV were contoured as target volumes in all three sets of PET images. The predictive value of the registered images was evaluated by comparing the preplanning and deformed PET volumes with the planning PET volume using Dice's coefficient (DC) and center-of-mass (COM) displacement. Results: The average DCs were 0.12±0.14 and 0.19±0.16 for rigid and deformable predicted target volumes, respectively. The average COM displacements were 1.9±0.9 cm and 1.7±0.7 cm for rigid and deformable registration, respectively. The DCs were improved by deformable registration, however, both were lower than published data for DIR in other modalities and clinical sites. Anatomical changes caused by different brachytherapy applicators could have posed a challenge to the DIR algorithm. The physiological change from interstitial needle placement may also contribute to lower DC. Conclusion: The clinical use of DIR in PET/CT for cervical cancer brachytherapy appears to be limited by applicator choice and requires further

  2. The impact of pet loss on the perceived social support and psychological distress of hurricane survivors.

    PubMed

    Lowe, Sarah R; Rhodes, Jean E; Zwiebach, Liza; Chan, Christian S

    2009-06-01

    Associations between pet loss and posthurricane perceived social support and psychological distress were explored. Participants (N = 365) were primarily low-income African American single mothers who were initially part of an educational intervention study. All participants were exposed to Hurricane Katrina, and 47% experienced Hurricane Rita. Three waves of survey data, two from before the hurricanes, were included. Sixty-three participants (17.3%) reported losing a pet due to the hurricanes and their aftermath. Pet loss significantly predicted postdisaster distress, above and beyond demographic variables, pre- and postdisaster perceived social support, predisaster distress, hurricane-related stressors, and human bereavement, an association that was stronger for younger participants. Pet loss was not a significant predictor of postdisaster perceived social support, but the impact of pet loss on perceived social support was significantly greater for participants with low levels of predisaster support. PMID:19462438

  3. Finite Element Modeling of Reheat Stretch Blow Molding of PET

    NASA Astrophysics Data System (ADS)

    Krishnan, Dwarak; Dupaix, Rebecca B.

    2004-06-01

    Poly (ethylene terephthalate) or PET is a polymer used as a packaging material for consumer products such as beverages, food or other liquids, and in other applications including drawn fibers and stretched films. Key features that make it widely used are its transparency, dimensional stability, gas impermeability, impact resistance, and high stiffness and strength in certain preferential directions. These commercially useful properties arise from the fact that PET crystallizes upon deformation above the glass transition temperature. Additionally, this strain-induced crystallization causes the deformation behavior of PET to be highly sensitive to processing conditions. It is thus crucial for engineers to be able to predict its performance at various process temperatures, strain rates and strain states so as to optimize the manufacturing process. In addressing these issues; a finite element analysis of the reheat blow molding process with PET has been carried out using ABAQUS. The simulation employed a constitutive model for PET developed by Dupaix and Boyce et al.. The model includes the combined effects of molecular orientation and strain-induced crystallization on strain hardening when the material is deformed above the glass transition temperature. The simulated bottles were also compared with actual blow molded bottles to evaluate the validity of the simulation.

  4. Diffuse Large B-Cell Lymphoma: Prospective Multicenter Comparison of Early Interim FLT PET/CT versus FDG PET/CT with IHP, EORTC, Deauville, and PERCIST Criteria for Early Therapeutic Monitoring.

    PubMed

    Minamimoto, Ryogo; Fayad, Luis; Advani, Ranjana; Vose, Julie; Macapinlac, Homer; Meza, Jane; Hankins, Jordan; Mottaghy, Felix; Juweid, Malik; Quon, Andrew

    2016-07-01

    Purpose To compare the performance characteristics of interim fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) (after two cycles of chemotherapy) by using the most prominent standardized interpretive criteria (including International Harmonization Project [IHP] criteria, European Organization for Research and Treatment of Cancer [EORTC] criteria, and PET Response Criteria in Solid Tumors (PERCIST) versus those of interim (18)F fluorothymidine (FLT) PET/CT and simple visual interpretation. Materials and Methods This HIPAA-compliant prospective study was approved by the institutional review boards, and written informed consent was obtained. Patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) underwent both FLT and FDG PET/CT 18-24 days after two cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone or rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin. For FDG PET/CT interpretation, IHP criteria, EORTC criteria, PERCIST, Deauville criteria, standardized uptake value, total lesion glycolysis, and metabolic tumor volume were used. FLT PET/CT images were interpreted with visual assessment by two reviewers in consensus. The interim (after cycle 2) FDG and FLT PET/CT studies were then compared with the end-of-treatment FDG PET/CT studies to determine which interim examination and/or criteria best predicted the result after six cycles of chemotherapy. Results From November 2011 to May 2014, there were 60 potential patients for inclusion, of whom 46 patients (24 men [mean age, 60.9 years ± 13.7; range, 28-78 years] and 22 women [mean age, 57.2 years ± 13.4; range, 25-76 years]) fulfilled the criteria. Thirty-four patients had complete response, and 12 had residual disease at the end of treatment. FLT PET/CT had a significantly higher positive predictive value (PPV) (91%) in predicting residual disease than did any FDG PET/CT interpretation method

  5. Evaluation and use of pet foods: general considerations in using pet foods for adult maintenance.

    PubMed

    Kallfelz, F A

    1989-05-01

    Questions regarding pet animal nutrition are probably among the most frequent queries encountered by companion animal veterinarians. Given the plethora of pet food products available and the amount of advertising used to promote them, it is not surprising that pet owners have concerns as to what they should feed their pets. This "practical" review of pet foods and feeding is designed to assist veterinarians in making nutritional recommendations to their clients, with respect to feeding normal adult pets at maintenance. PMID:2658281

  6. Feasibility of Using Distal Endpoints for In-room PET Range Verification of Proton Therapy

    PubMed Central

    Grogg, Kira; Zhu, Xuping; Min, Chul Hee; Winey, Brian; Bortfeld, Thomas; Paganetti, Harald; Shih, Helen A.; El Fakhri, Georges

    2013-01-01

    In an effort to verify the dose delivery in proton therapy, Positron Emission Tomography (PET) scans have been employed to measure the distribution of β+ radioactivity produced from nuclear reactions of the protons with native nuclei. Because the dose and PET distributions are difficult to compare directly, the range verification is currently carried out by comparing measured and Monte Carlo (MC) simulation predicted PET distributions. In order to reduce the reliance on MC, simulated PET (simPET) and dose distal endpoints were compared to explore the feasibility of using distal endpoints for in-room PET range verification. MC simulations were generated for six head and neck patients with corrections for radiological decay, biological washout, and PET resolution. One-dimensional profiles of the dose and simPET were examined along the direction of the beam and covering the cross section of the beam. The chosen endpoints of the simPET (x-intercept of the linear fit to the distal falloff) and planned dose (20–50% of maximum dose) correspond to where most of the protons are below the threshold energy for the nuclear reactions. The difference in endpoint range between the distal surfaces of the dose and MC-PET were compared and the spread of range differences were assessed. Among the six patients, the mean difference between MC-PET and dose depth was found to be −1.6 mm to +0.5 mm between patients, with a standard deviation of 1.1 to 4.0 mm across the individual beams. In clinical practice, regions with deviations beyond the safety margin need to be examined more closely and can potentially lead to adjustments to the treatment plan. PMID:24464031

  7. Veterinarians' role for pet owners facing pet loss

    PubMed Central

    Fernandez-Mehler, P.; Gloor, P.; Sager, E.; Lewis, F. I.; Glaus, T. M

    2013-01-01

    Owners' satisfaction with, and expectations from, their veterinarians around euthanasia, including questions on disposal of pet remains subject to animal species, clients' gender, age, family conditions, area of living and type of veterinary clinic visited were evaluated by questionnaire. Questionnaires were to be filled out by clients consecutively visiting the individual practices and hospitals for any kind of consultations. Of 2350 questionnaires distributed, 2008 were returned and available for analysis. Owner satisfaction concerning the procedure of euthanasia was high (92 per cent, 1173/1272). After the event of euthanasia, 14 per cent (170/1250) had changed their veterinarian, even though 75 per cent of these 170 had been satisfied with the procedure. Most owners (88 per cent) expected veterinarians to talk about their pet's final destination, and 38 per cent expected this to happen early in the pet's life. For 81 per cent clients, the veterinarian was the primary informant about the possibilities concerning the disposal of pet remains, and 33 per cent indicated their veterinarian as the contact person to talk about pet loss. Area of living, or veterinary specialisation, only marginally influenced the answers. Veterinarians play an important role to inform their clients concerning questions around euthanasia and the care of pet remains, and to support them during the process of mourning. PMID:23492929

  8. PET/CT in radiation oncology

    SciTech Connect

    Pan, Tinsu; Mawlawi, Osama

    2008-11-15

    PET/CT is an effective tool for the diagnosis, staging and restaging of cancer patients. It combines the complementary information of functional PET images and anatomical CT images in one imaging session. Conventional stand-alone PET has been replaced by PET/CT for improved patient comfort, patient throughput, and most importantly the proven clinical outcome of PET/CT over that of PET and that of separate PET and CT. There are over two thousand PET/CT scanners installed worldwide since 2001. Oncology is the main application for PET/CT. Fluorine-18 deoxyglucose is the choice of radiopharmaceutical in PET for imaging the glucose uptake in tissues, correlated with an increased rate of glycolysis in many tumor cells. New molecular targeted agents are being developed to improve the accuracy of targeting different disease states and assessing therapeutic response. Over 50% of cancer patients receive radiation therapy (RT) in the course of their disease treatment. Clinical data have demonstrated that the information provided by PET/CT often changes patient management of the patient and/or modifies the RT plan from conventional CT simulation. The application of PET/CT in RT is growing and will become increasingly important. Continuing improvement of PET/CT instrumentation will also make it easier for radiation oncologists to integrate PET/CT in RT. The purpose of this article is to provide a review of the current PET/CT technology, to project the future development of PET and CT for PET/CT, and to discuss some issues in adopting PET/CT in RT and potential improvements in PET/CT simulation of the thorax in radiation therapy.

  9. PET Pharmacokinetic Modelling

    NASA Astrophysics Data System (ADS)

    Müller-Schauenburg, Wolfgang; Reimold, Matthias

    Positron Emission Tomography is a well-established technique that allows imaging and quantification of tissue properties in-vivo. The goal of pharmacokinetic modelling is to estimate physiological parameters, e.g. perfusion or receptor density from the measured time course of a radiotracer. After a brief overview of clinical application of PET, we summarize the fundamentals of modelling: distribution volume, Fick's principle of local balancing, extraction and perfusion, and how to calculate equilibrium data from measurements after bolus injection. Three fundamental models are considered: (i) the 1-tissue compartment model, e.g. for regional cerebral blood flow (rCBF) with the short-lived tracer [15O]water, (ii) the 2-tissue compartment model accounting for trapping (one exponential + constant), e.g. for glucose metabolism with [18F]FDG, (iii) the reversible 2-tissue compartment model (two exponentials), e.g. for receptor binding. Arterial blood sampling is required for classical PET modelling, but can often be avoided by comparing regions with specific binding with so called reference regions with negligible specific uptake, e.g. in receptor imaging. To estimate the model parameters, non-linear least square fits are the standard. Various linearizations have been proposed for rapid parameter estimation, e.g. on a pixel-by-pixel basis, for the prize of a bias. Such linear approaches exist for all three models; e.g. the PATLAK-plot for trapping substances like FDG, and the LOGAN-plot to obtain distribution volumes for reversibly binding tracers. The description of receptor modelling is dedicated to the approaches of the subsequent lecture (chapter) of Millet, who works in the tradition of Delforge with multiple-injection investigations.

  10. Pets and the immunocompromised person

    MedlinePlus

    ... Do not adopt wild or exotic animals. These animals are more likely to bite. They often carry rare but ... its feces because salmonella is easily passed from animal to human. Wear ... on pet-related infections, contact your veterinarian ...

  11. Take Care with Pet Reptiles

    MedlinePlus

    ... pets in households with young children. [775 KB] Animals and Health Check out two CDC websites with helpful resources. Gastrointestinal (Enteric) Diseases from Animals : Information about zoonotic outbreaks, prevention messages, and helpful ...

  12. 10 "Poison Pills" for Pets

    MedlinePlus

    ... left on the bedside table. Zolpidem may make cats wobbly and sleepy, but most pets become very ... very common pain killer found in most households. Cats are extremely sensitive to acetaminophen, but dogs can ...

  13. Should Immunocompromised Patients Have Pets?

    PubMed Central

    Steele, Russell W.

    2008-01-01

    Purpose: To evaluate the risks and benefits of pet ownership by immunodeficient patients, focusing primarily on organisms that colonize animals and are transmitted to humans. Those diseases that are known to be progressive or more severe in patients with altered immune function are emphasized. Methods: A review of the medical and veterinary literature pertaining to zoonoses transmitted by domestic animals was completed. Information pertaining to issues involving immunosuppressed patients including AIDS was carefully evaluated and summarized for inclusion. Results: There are significant clinical and psychosocial benefits to pet ownership. However, numerous diseases can be acquired from these animals which may be more severe in immunocompromised individuals. Conclusion: Simple guidelines for pet ownership by immunosuppressed patients can be implemented to reduce their risk of disease and allow them to safely interchange with their pets. PMID:21603465

  14. The role of PET/CT as a prognosticator and outcome predictor in lung cancer.

    PubMed

    Khiewvan, Benjapa; Ziai, Pouya; Houshmand, Sina; Salavati, Ali; Ziai, Peyman; Alavi, Abass

    2016-03-01

    Positron emission tomography/computed tomography (PET/CT) is an important imaging tool for management of lung cancer and can be utilized in diagnosis, staging, restaging, treatment planning and evaluating treatment response. In the past decade PET/CT has proven to be beneficial for the prediction of prognosis and outcome. PET findings before and after treatment, the quantitative PET parameters such as standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) as well as delayed PET/CT imaging can be used to determine patient prognosis and outcome. Other tracers such as hypoxia and proliferation marker tracers may be used for prognostication. The prognostic factors derived from PET/CT imaging help early development of risk-adapted treatment strategies, which provides cost-effective treatment and leads to improved patient management. Here, we discuss findings of studies related to application of PET/CT in lung cancer as well as some technical updates on quantitative PET/CT in lung cancer. PMID:26822467

  15. Prognostic significance of SUV on PET/CT in patients with localised oesophagogastric junction cancer receiving neoadjuvant chemotherapy/chemoradiation: a systematic review and meta-analysis

    PubMed Central

    Zhu, W; Xing, L; Yue, J; Sun, X; Sun, X; Zhao, H; Yu, J

    2012-01-01

    Objective The objective of this study was to comprehensively review the evidence for use of pre-treatment, post-treatment and changes in tumour glucose uptake that were assessed by 18-fludeoxyglucose (18F-FDG) positron emission tomography (PET) early, during or immediately after neoadjuvant chemotherapy/chemoradiation to predict prognosis of localised oesophagogastric junction (AEG) cancer. Methods We searched for articles published in English; limited to AEG; 18F-FDG uptake on PET performed on a dedicated device; dealt with the impact of standard uptake value (SUV) on survival. We extracted an estimate of the log hazard ratios (HRs) and their variances and performed meta-analysis. Results 798 patients with AEG were included. And the scan time for 18F-FDG-PET was as follows: prior to therapy (PET1, n=646), exactly 2 weeks after initiation of neoadjuvant therapy (PET2, n=245), and pre-operatively (PET3, n=278). In the two meta-analyses for overall survival, including the studies that dealt with reduction of tumour maximum SUV (SUVmax) (from PET1 to PET2/PET3 and from PET1 to PET2), the results were similar, with the overall HR for non-responders being 1.83 [95% confidence interval (CI), 1.41–2.36] and 2.62 (95% CI, 1.61–4.26), respectively; as for disease-free survival, the combined HR was 2.92 (95% CI, 2.08–4.10) and 2.39 (95% CI, 1.57–3.64), respectively. The meta-analyses did not attribute significant prognostic values to SUVmax before and during therapy in localised AEG. Conclusion Relative changes in FDG-uptake of AEG are better prognosticators. Early metabolic changes from PET1 to PET2 may provide the same accuracy for prediction of treatment outcome as late changes from PET1 to PET3. PMID:22337686

  16. Should pet owners be regulated?

    PubMed

    Mills, Georgina

    2013-12-21

    To own a television, you have to have a licence, and to drive a car, you have to pass a test. However, there are no such limitations on owning a pet. Should this be changed, and what can be done to encourage more responsible pet ownership? This topic was discussed at the BVA Congress at the London Vet Show on November 21. Georgina Mills reports. PMID:24362802

  17. Vascular endothelial growth factor C complements the ability of positron emission tomography to predict nodal disease in lung cancer

    PubMed Central

    Farjah, Farhood; Madtes, David K.; Wood, Douglas E.; Flum, David R.; Zadworny, Megan E.; Waworuntu, Rachel; Hwang, Billanna; Mulligan, Michael S.

    2016-01-01

    Objective Vascular endothelial growth factors (VEGFs) C and D are biologically rational markers of nodal disease that could improve the accuracy of lung cancer staging. We hypothesized that these biomarkers would improve the ability of positron emission tomography (PET) to predict nodal disease among patients with suspected or confirmed non–small cell lung cancer (NSCLC). Methods A cross-sectional study (2010–2013) was performed of patients prospectively enrolled in a lung nodule biorepository, staged by computed tomography (CT) and PET, and who underwent pathologic nodal evaluation. Enzyme-linked immunosorbent assay was used to measure biomarker levels in plasma from blood drawn before anesthesia. Likelihood ratio testing was used to compare the following logistic regression prediction models: ModelPET, ModelPET/VEGF-C, ModelPET/VEGF-D, and ModelPET/VEGF-C/VEGF-D. To account for 5 planned pairwise comparisons, P values<.01 were considered significant. Results Among 62 patients (median age, 67 years; 48% men; 87% white; and 84% NSCLC), 58% had fluorodeoxyglucose uptake in hilar and/or mediastinal lymph nodes. The prevalence of pathologically confirmed lymph node metastases was 40%. Comparisons of prediction models revealed the following: ModelPET/VEGF-C versus ModelPET (P = .0069), ModelPET/VEGF-D versus ModelPET (P = .1886), ModelPET/VEGF-C/VEGF-D versus ModelPET (P = .0146), ModelPET/VEGF-C/VEGF-D versus ModelPET/VEGF-C (P = .2818), and ModelPET/VEGF-C/VEGF-D versus ModelPET/VEGF-D (P = .0095). In ModelPET/VEGF-C, higher VEGF-C levels were associated with an increased risk of nodal disease (odds ratio, 2.96; 95% confidence interval, 1.26–6.90). Conclusions Plasma levels of VEGF-C complemented the ability of PET to predict nodal disease among patients with suspected or confirmed NSCLC. VEGF-D did not improve prediction. PMID:26320776

  18. Advances in Clinical PET/MRI Instrumentation.

    PubMed

    Herzog, Hans; Lerche, Christoph

    2016-04-01

    In 2010, the first whole-body PET/MRI scanners installed for clinical use were the sequential Philips PET/MRI with PMT-based, TOF-capable technology and the integrated simultaneous Siemens PET/MRI. Avalanche photodiodes as non-magneto-sensitive readout electronics allowed PET integrated within the MRI. The experiences with these scanners showed that improvements of software aspects, such as attenuation correction, were necessary and that efficient protocols combining optimally PET and MRI must be still developed. In 2014, General Electric issued an integrated PET/MRI with SiPM-based PET detectors, allowing TOF-PET. Looking at the MRI components of current PET/MR imaging systems, primary improvements come from sequences and new coils. PMID:26952724

  19. Nutritional sustainability of pet foods.

    PubMed

    Swanson, Kelly S; Carter, Rebecca A; Yount, Tracy P; Aretz, Jan; Buff, Preston R

    2013-03-01

    Sustainable practices meet the needs of the present without compromising the ability of future generations to meet their needs. Applying these concepts to food and feed production, nutritional sustainability is the ability of a food system to provide sufficient energy and essential nutrients required to maintain good health in a population without compromising the ability of future generations to meet their nutritional needs. Ecological, social, and economic aspects must be balanced to support the sustainability of the overall food system. The nutritional sustainability of a food system can be influenced by several factors, including the ingredient selection, nutrient composition, digestibility, and consumption rates of a diet. Carbon and water footprints vary greatly among plant- and animal-based ingredients, production strategy, and geographical location. Because the pet food industry is based largely on by-products and is tightly interlinked with livestock production and the human food system, however, it is quite unique with regard to sustainability. Often based on consumer demand rather than nutritional requirements, many commercial pet foods are formulated to provide nutrients in excess of current minimum recommendations, use ingredients that compete directly with the human food system, or are overconsumed by pets, resulting in food wastage and obesity. Pet food professionals have the opportunity to address these challenges and influence the sustainability of pet ownership through product design, manufacturing processes, public education, and policy change. A coordinated effort across the industry that includes ingredient buyers, formulators, and nutritionists may result in a more sustainable pet food system. PMID:23493530

  20. PET Imaging in Huntington's Disease.

    PubMed

    Roussakis, Andreas-Antonios; Piccini, Paola

    2015-01-01

    To date, little is known about how neurodegeneration and neuroinflammation propagate in Huntington's disease (HD). Unfortunately, no treatment is available to cure or reverse the progressive decline of function caused by the disease, thus considering HD a fatal disease. Mutation gene carriers typically remain asymptomatic for many years although alterations in the basal ganglia and cortex occur early on in mutant HD gene-carriers. Positron Emission Tomography (PET) is a functional imaging technique of nuclear medicine which enables in vivo visualization of numerous biological molecules expressed in several human tissues. Brain PET is most powerful to study in vivo neuronal and glial cells function as well as cerebral blood flow in a plethora of neurodegenerative disorders including Parkinson's disease, Alzheimer's and HD. In absence of HD-specific biomarkers for monitoring disease progression, previous PET studies in HD were merely focused on the study of dopaminergic terminals, cerebral blood flow and glucose metabolism in manifest and premanifest HD-gene carriers. More recently, research interest has been exploring novel PET targets in HD including the state of phosphodiesterse expression and the role of activated microglia. Hence, a better understanding of the HD pathogenesis mechanisms may lead to the development of targeted therapies. PET imaging follow-up studies with novel selective PET radiotracers such as 11C-IMA-107 and 11C-PBR28 may provide insight on disease progression and identify prognostic biomarkers, elucidate the underlying HD pathology and assess novel pharmaceutical agents and over time. PMID:26683130

  1. Prognostic value of interim and end-of-treatment FDG-PET in follicular lymphoma: a systematic review.

    PubMed

    Adams, Hugo J A; Nievelstein, Rutger A J; Kwee, Thomas C

    2016-01-01

    This study aimed to systematically review the prognostic value of interim and end-of-treatment (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in follicular lymphoma during and after first-line therapy. The PubMed/MEDLINE database was searched for relevant original studies. Included studies were methodologically assessed, and their results were extracted and descriptively analyzed. Three studies on the prognostic value of interim FDG-PET and eight studies on the prognostic value of end-of-treatment FDG-PET were included. Overall, studies were of poor methodological quality. In addition, there was incomplete reporting of progression-free survival (PFS) and overall survival (OS) data by several studies, and none of the studies incorporated the Follicular Lymphoma International Prognostic Index (FLIPI) in the OS analyses. Two studies reported no significant difference in PFS between interim FDG-PET positive and negative patients, whereas one study reported a significant difference in PFS between the two groups. Two studies reported no significant difference in OS between interim FDG-PET positive and negative patients. Five studies reported end-of-treatment FDG-PET positive patients to have a significantly worse PFS than end-of-treatment FDG-PET negative patients, and one study reported a non-significant trend towards a worse PFS for end-of-treatment FDG-PET positive patients. Three studies reported end-of-treatment FDG-PET positive patients to have a significantly worse OS than end-of-treatment FDG-PET negative patients. In conclusion, the available evidence does not support the use of interim FDG-PET in follicular lymphoma. Although published studies suggest end-of-treatment FDG-PET to be predictive of PFS and OS, they suffer from numerous biases and failure to correct OS prediction for the FLIPI. PMID:26576560

  2. PET Scans for Staging and Restaging in Diffuse Large B-Cell and Follicular Lymphomas.

    PubMed

    Barrington, Sally F; Mikhaeel, N George

    2016-06-01

    Positron emission tomography (PET)-CT was recommended in updated international guidelines for staging/restaging of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). In FL, PET was previously regarded as a research application only. This review concentrates on new publications related to PET in these diseases. In DLBCL, PET appears appropriate for staging using prognostic indices established with CT and baseline PET parameters, e.g. metabolic tumour volume, are prognostic of outcome. Early complete metabolic response (CMR) predicts end-of-treatment CMR with excellent prognosis. Patients without CMR at interim should not have treatment altered, but have a worse prognosis, and patients with other high risk features may need closer monitoring. The end-of-treatment scan is confirmed as the standard for remission assessment using Deauville criteria, which are also predictive for patients undergoing ASCT. In FL, PET is more sensitive for staging than CT but misses bone marrow involvement. PET-CT identifies patients at risk of progression after induction chemotherapy better than CT. PMID:27095319

  3. Prognostic significance of bone marrow infiltration detected by PET-CT in newly diagnosed diffuse large B cell lymphoma

    PubMed Central

    Liang, Jin-Hua; Sun, Jin; Wang, Li; Fan, Lei; Chen, Yao-Yu; Qu, Xiao-Yan; Li, Tian-Nv; Li, Jian-Yong; Xu, Wei

    2016-01-01

    The aim of this study was to examine the prognostic value of bone marrow involvement (BMI) assessed by baseline PET-CT (PET(0)-BMI) in treatment-naïve patients with diffuse large B-cell lymphoma (DLBCL). All patients from a single centre diagnosed as DLBCL between 2005 and 2014 had data extracted from staging PET-CT (PET(0)-CT), bone marrow biopsy (BMB), and treatment records. The PET(3)-CT (PET-CT scan after cycle 3 of immunochemotherapy) was performed on all the patients with PET(0)-BMI positivity (PET(0)-BMI(+)). Of 169 patients, 20 (11.8%) had BMI on BMB, whereas 35 (20.7%) were PET(0)-BMI positive. Among PET(0)-BMI(+) patients, patients with maximum of standard uptake value (SUVmax) of bone marrow (SUVmax(BM)) more than 8.6 were significantly associated with high IPI score (3–5) (P=0.002), worse progression-free survival (PFS) and overall survival (OS) (P=0.025 and P=0.002, respectively). In the 68 stage IV cases, 3-year OS was higher in the patients with negative PET(0)-BMI (PET(0)-BMI(−)) than that with PET(0)-BMI(+) (84.2%±6.5% vs. 44.1%±8.6%; P=0.003), while 3-year PFS only shown a trend of statistic significance (P=0.077) between the two groups. Among the 69 patients of inter-risk of IPI (2–3), patients with PET(0)-BMI(+) had significantly inferior PFS and OS than that with PET(0)-BMI(−) (P=0.009 and P<0.001, respectively). The cut-off value of the decreased percentage of SUVmax(BM) between PET(0)-CT and PET(3)-CT (ΔSUVmax(BM)) was 70.0%, which can predict PFS (P=0.003) and OS (P=0.023). These data confirmed that along with the increased sensitivity and accuracy of identifying bone marrow by PET-CT, novel prognostic values of marrow involvement were found in patients with DLBCL. PMID:26919239

  4. Parasites in pet reptiles

    PubMed Central

    2011-01-01

    Exotic reptiles originating from the wild can be carriers of many different pathogens and some of them can infect humans. Reptiles imported into Slovenia from 2000 to 2005, specimens of native species taken from the wild and captive bred species were investigated. A total of 949 reptiles (55 snakes, 331 lizards and 563 turtles), belonging to 68 different species, were examined for the presence of endoparasites and ectoparasites. Twelve different groups (Nematoda (5), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (4)) of endoparasites were determined in 26 (47.3%) of 55 examined snakes. In snakes two different species of ectoparasites were also found. Among the tested lizards eighteen different groups (Nematoda (8), Cestoda (1), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (6)) of endoparasites in 252 (76.1%) of 331 examined animals were found. One Trombiculid ectoparasite was determined. In 563 of examined turtles eight different groups (Nematoda (4), Cestoda (1), Trematoda (1) and Protozoa (2)) of endoparasites were determined in 498 (88.5%) animals. In examined turtles three different species of ectoparasites were seen. The established prevalence of various parasites in reptiles used as pet animals indicates the need for examination on specific pathogens prior to introduction to owners. PMID:21624124

  5. Quantitative PET imaging with the 3T MR-BrainPET

    NASA Astrophysics Data System (ADS)

    Weirich, C.; Scheins, J.; Lohmann, P.; Tellmann, L.; Byars, L.; Michel, C.; Rota Kops, E.; Brenner, D.; Herzog, H.; Shah, N. J.

    2013-02-01

    The new hybrid imaging technology of MR-PET allows for simultaneous acquisition of versatile MRI contrasts and the quantitative metabolic imaging with PET. In order to achieve the quantification of PET images with minimal residual error the application of several corrections is crucial. In this work we present our results on quantification with the 3T MR BrainPET scanner.

  6. Children's drawings and attachment to pets.

    PubMed

    Kidd, A H; Kidd, R M

    1995-08-01

    To help confirm the concept that distances placed between the self and other figures in children's drawings represent emotional distances, 242 pet-owning and 35 nonpet-owning kindergartners through eighth graders drew pictures of themselves, a pet, and/or a family member. Owners drew pets significantly closer than family-figures although the younger the child, the greater the distance between self and pet. Older children drew themselves holding pets significantly more often, but younger children placed the family-figure between the self and the pet significantly more often. There were no significant gender differences in self-figure/pet-figure distances, but cats, dogs, caged animals, and farm animals were placed significantly closer to self-figures than were fish. Over-all, owners were clearly emotionally closer to pets than to family members, but nonowners were as close emotionally to family members as were owners. PMID:7501763

  7. 4D offline PET-based treatment verification in scanned ion beam therapy: a phantom study

    NASA Astrophysics Data System (ADS)

    Kurz, Christopher; Bauer, Julia; Unholtz, Daniel; Richter, Daniel; Stützer, Kristin; Bert, Christoph; Parodi, Katia

    2015-08-01

    At the Heidelberg Ion-Beam Therapy Center, patient irradiation with scanned proton and carbon ion beams is verified by offline positron emission tomography (PET) imaging: the {β+} -activity measured within the patient is compared to a prediction calculated on the basis of the treatment planning data in order to identify potential delivery errors. Currently, this monitoring technique is limited to the treatment of static target structures. However, intra-fractional organ motion imposes considerable additional challenges to scanned ion beam radiotherapy. In this work, the feasibility and potential of time-resolved (4D) offline PET-based treatment verification with a commercial full-ring PET/CT (x-ray computed tomography) device are investigated for the first time, based on an experimental campaign with moving phantoms. Motion was monitored during the gated beam delivery as well as the subsequent PET acquisition and was taken into account in the corresponding 4D Monte-Carlo simulations and data evaluation. Under the given experimental conditions, millimeter agreement between the prediction and measurement was found. Dosimetric consequences due to the phantom motion could be reliably identified. The agreement between PET measurement and prediction in the presence of motion was found to be similar as in static reference measurements, thus demonstrating the potential of 4D PET-based treatment verification for future clinical applications.

  8. [PET and SPECT in epilepsy].

    PubMed

    Setoain, X; Carreño, M; Pavía, J; Martí-Fuster, B; Campos, F; Lomeña, F

    2014-01-01

    Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with (18)FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed. PMID:24565567

  9. Recent Understandings of Pet Allergies

    PubMed Central

    Ownby, Dennis; Johnson, Christine Cole

    2016-01-01

    Allergic reactions to pets have been recognized for at least a hundred years. Yet our understanding of the effects of all of the interactions between pet exposures and human immune responses continues to grow. Allergists, epidemiologists, and immunologists have spent years trying to better understand how exposures to pet allergens lead to allergic sensitization (the production of allergen-specific immunoglobulin class E [IgE] antibodies) and subsequent allergic disease. A major new development in this understanding is the recognition that pet exposures consist of not only allergen exposures but also changes in microbial exposures. Exposures to certain pet-associated microbes, especially in the neonatal period, appear to be able to dramatically alter how a child’s immune system develops and this in turn reduces the risk of allergic sensitization and disease. An exciting challenge in the next few years will be to see whether these changes can be developed into a realistic preventative strategy with the expectation of significantly reducing allergic disease, especially asthma. PMID:26918180

  10. Measurement of hypoxia-related parameters in three sublines of a rat prostate carcinoma using dynamic 18F-FMISO-Pet-Ct and quantitative histology

    PubMed Central

    Mena-Romano, Pamela; Cheng, Caixia; Glowa, Christin; Peschke, Peter; Pan, Leyun; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia; Karger, Christian P

    2015-01-01

    Hypoxia is an important resistance factor in radiotherapy and measuring its spatial distribution in tumors non-invasively is therefore of major importance. This study characterizes the hypoxic conditions of three tumor sublines (AT1, HI and H) of the Dunning R3327 prostate tumor model, which differ in histology, differentiation degree, volume doubling time and androgenic sensitivity, using dynamic Fluoromisonidazole (18F-FMISO)-Positron Emission Tomography/Computed Tomography (PET-CT) and histology. Measurements were performed for two tumor volumes (average 0.8±0.5 cm3 vs 4.4±2.8 cm3). Data were analyzed according to tumor subline as well as to the shape of the time activity curves (TACs), based on standardized uptake values (SUVs) and a two-tissue compartment model. Quantitative immunohistochemical studies of the hypoxic fraction, vessel density and vessel size were performed using pimonidazole, Hoechst 33342 and CD31 dyes. No significant FMISO uptake was found in small tumors, which had a mean SUV of 0.64±0.36, 0.55±0.10 and 0.45±0.08, for AT1, HI and H sublines respectively. In large tumors, the SUVs were 1.33±0.52, 1.12±0.83 and 0.63±0.16 for AT1, HI and H sublines and the corresponding hypoxic fractions obtained with pimonidazole staining were 0.62±0.23, 0.54±0.24 and 0.07±0.10, respectively. The AT1- was the most and H-tumor was the least hypoxic for both methods (P<0.05). All measurements were able to discriminate different hypoxic conditions, however despite SUV and kinetic parameters correlated with the three identified TAC shapes, most of the histological results did not. These results demonstrate impact and limitations of static and dynamic PET-CT measurements to assess hypoxia non-invasively. PMID:26269773

  11. Detection of prostate cancer by an FDG-PET cancer screening program: results from a Japanese nationwide survey

    PubMed Central

    Minamimoto, Ryogo; Senda, Michio; Jinnouchi, Seishi; Terauchi, Takashi; Inoue, Tomio

    2014-01-01

    Objective(s): The aim of this study was to analyze detection rates and effectiveness of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) cancer screening program for prostate cancer in Japan, which is defined as a cancer-screening program for subjects without known cancer. It contains FDG-PET aimed at detection of cancer at an early stage with or without additional screening tests such as prostate-specific antigen (PSA) and magnetic resonance imaging (MRI). Methods: A total of 92,255 asymptomatic men underwent the FDG-PET cancer screening program. Of these, 504 cases with findings of possible prostate cancer in any screening method were analyzed. Results: Of the 504 cases, 165 were verified as having prostate cancer. Of these, only 61 cases were detected by FDG-PET, which result in 37.0% relative sensitivity and 32.8% positive predictive value (PPV). The sensitivity of PET/computed tomography (CT) scanner was higher than that of dedicated PET (44.0% vs. 20.4%). However, the sensitivity of FDG-PET was lower than that of PSA and pelvic MRI. FDG-PET did not contribute to improving the sensitivity and PPV when performed as combined screening. Conclusion: PSA should be included in FDG-PET cancer screening programs to screen for prostate cancer.

  12. A Guide to Managing Your Classroom Pets.

    ERIC Educational Resources Information Center

    Caras, Robert

    1980-01-01

    The author suggests eight ideal classroom pets: hamsters; turtles; snakes; spiders; frogs and toads; fish; and birds. For each he gives suggestions on selecting the pet and housing and feeding it in the classroom. Desert terrariums and home pet care training are also discussed. (SJL)

  13. Pet care during preadolescence: developmental considerations.

    PubMed

    Davis, J H

    1987-01-01

    This exploratory study investigated pet care in relation to psychosocial development during preadolescence. A group of male and female preadolescents (n = 22) at appropriate grade level for age completed a dog care responsibility inventory. The results revealed that preadolescents in general do not routinely care for pets. Mothers appear to assume most pet care tasks. PMID:3664972

  14. PET/MRI: challenges, solutions and perspectives.

    PubMed

    Herzog, Hans

    2012-12-01

    Already from the start of PET/CT integrating positron emission tomography (PET) and computed tomography (CT) in one instrument, there have been considerations how to combine PET and magnetic resonance imaging (MRI) so that their complementary abilities can be utilized in a single investigation. Since classical PET electronics fail in an even weak magnetic field and PET signal processing might disturb high-frequency signals of MRI, it soon became clear that new solutions had to be found to avoid mutual interferences. During the last fifteen years a number of different approaches towards PET/MRI for small animal imaging have been developed by research groups which together with their specific features are summarized in this review. Recently, PET/MRI for human imaging became available as well - this time by industrial initiatives. First some prototypes of BrainPET/MRI were developed followed by commercial products for simultaneous and non-simultaneous whole-body PET/MRI. Although only PET/MRI integrated in one scanner offers the full diversity of complementary multiparametric imaging, there are also promising applications of non-simultaneous sequential PET/MRI. While describing the present instrumentation for human PET/MRI, this review discusses the challenges and promises related to this new imaging technology. PMID:22925652

  15. PET imaging: An overview and instrumentation

    SciTech Connect

    Daghighian, F.; Sumida, R.; Phelps, M.E. )

    1990-03-01

    This is the first article of a four-part series on positron emission tomography (PET). Upon completing the article, the reader should be able to: (1) comprehend the basic principles of PET; (2) explain various technical aspects; and (3) identify radiopharmaceuticals used in PET imaging.

  16. The evolution of PET-CT.

    PubMed

    Wilson, Bettye G

    2005-01-01

    Positron emission tomography-computed tomography (PET-CT) was the first fused or combined medical imaging technique. Although PET-CT has received widespread acclaim as a major imaging advancement, many questions have surfaced regarding its use. This article answers some of these questions and examines what PET-CT means to medicine and the medical imaging community. PMID:15835615

  17. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  18. 36 CFR 13.978 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Pets. 13.978 Section 13.978 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... (fda) § 13.978 Pets. Possessing a pet is prohibited— (a) In the FDA, except in public parking areas,...

  19. 36 CFR 13.978 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Pets. 13.978 Section 13.978 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... (fda) § 13.978 Pets. Possessing a pet is prohibited— (a) In the FDA, except in public parking areas,...

  20. 36 CFR 13.1106 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Pets. 13.1106 Section 13.1106 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... Provisions § 13.1106 Pets. Pets are prohibited except— (a) On the Bartlett Cove Public Use Dock; (b) On...

  1. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  2. 36 CFR 13.1106 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Pets. 13.1106 Section 13.1106 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... Provisions § 13.1106 Pets. Pets are prohibited except— (a) On the Bartlett Cove Public Use Dock; (b) On...

  3. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon...

  4. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon...

  5. Pet therapy: dogs de-stress students.

    PubMed

    Young, Judith S

    2012-01-01

    Research supports the efficacy of the human-animal bond and pet therapy in a variety of settings. At nursing students' request at one school, the author began offering pet therapy prior to examinations. Anecdotal evidence of a study with the author's Golden Retriever, Goldilocks, demonstrates that pet therapy can reduce test anxiety and improve nursing student performance. PMID:23082615

  6. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon...

  7. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  8. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  9. 36 CFR 13.1106 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Pets. 13.1106 Section 13.1106 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... Provisions § 13.1106 Pets. Pets are prohibited except— (a) On the Bartlett Cove Public Use Dock; (b) On...

  10. 36 CFR 13.1106 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Pets. 13.1106 Section 13.1106 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... Provisions § 13.1106 Pets. Pets are prohibited except— (a) On the Bartlett Cove Public Use Dock; (b) On...