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Sample records for transduced irradiated prostate

  1. Irradiation Testing of Ultrasonic Transducers

    International Nuclear Information System (INIS)

    Daw, J.; Rempe, J.; Palmer, J.; Tittmann, B.; Reinhardt, B.; Kohse, G.; Ramuhalli, P.; Montgomery, R.; Chien, H.T.; Villard, J.F.

    2013-06-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10 21 n/cm 2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. (authors)

  2. Updated Results of Ultrasonic Transducer Irradiation Test

    Energy Technology Data Exchange (ETDEWEB)

    Daw, Joshua; Palmer, Joe [Idaho National Laboratory, P.O. Box 1625, MS 4112, Idaho Falls, ID, 38415-3840 (United States); Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert [Pacific Northwest National Laboratory, 902 Battelle Blvd. Richland, WA, 99354 (United States); Chien, Hual-Te [Argonne National Laboratory, 9700 S. Cass Avenue Argonne, IL, 60439 (United States); Tittmann, Bernhard; Reinhardt, Brian [Pennsylvania State University, 212 Earth and Engr. Sciences Building, University Park, PA, 16802 (United States); Kohse, Gordon [Massachusetts Institute of Technology, 77 Massachusetts Ave. Cambridge, MA 02139 (United States); Rempe, Joy [Rempe and Associates, LLC, 360 Stillwater, Idaho Falls, ID 83404 (United States); Villard, J.F. [Commissariat a l' energie atomique et aux energies alternatives, Centre d' etudes de Cadarache, 13108 Saint-Paul-lez-Durance (France)

    2015-07-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10{sup 21} n/cm{sup 2}. A multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET-ASI) program also provided initial support for this effort. This irradiation, which started in February 2014, is an instrumented lead test and real-time transducer performance data are collected along with temperature and neutron and gamma flux data. The irradiation is ongoing and will continue to approximately mid-2015. To date, very encouraging results have been attained as several transducers continue to operate under irradiation. (authors)

  3. Neutron Irradiation Tests of Pressure Transducers in Liquid Helium

    CERN Document Server

    Amand, J F; Casas-Cubillos, J; Thermeau, J P

    1999-01-01

    The superconducting magnets of the future Large Hadron Collider (LHC) at CERN will operate in pressurised superfluid helium (1 bar, 1.9 K). About 500 pressure transducers will be placed in the liquid helium bath for monitoring the filling and the pressure transients after resistive transitions. Their precision must remain better than 100 mbar at pressures below 2 bar and better than 5% for higher pressures (up to 20 bar), with temperatures ranging from 1.8 K to 300 K. All the tested transducers are based on the same principle: the fluid or gas is separated from a sealed reference vacuum by an elastic membrane; its deformation indicates the pressure. The transducers will be exposed to high neutron fluence (2 kGy, 1014 n/cm2 per year) during the 20 years of machine operation. This irradiation may induce changes both on the membranes characteristics (leakage, modification of elasticity) and on gauges which measure their deformations. To investigate these effects and select the transducer to be used in the LHC, a...

  4. Irradiation Behavior and Post-Irradiation Examinations of an Acoustic Sensor Using a Piezoelectric Transducer

    International Nuclear Information System (INIS)

    Lambert, T.; Zacharie-Aubrun, I.; Hanifi, K.; Valot, Ch.; Fayette, L.; Rosenkantz, E.; Ferrandis, J.Y.; Tiratay, X.

    2013-06-01

    The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. In the framework of high burn-up fuel experiments under transient operating conditions, an innovative sensor based on acoustic method was developed by CEA and IES (Southern Electronic Institute).This sensor is used to determine the on-line composition of the gases located in fuel rodlet free volume and thus, allows calculating the molar fractions of fission gases and helium. The main principle of the composition determination by acoustic method consists in measuring the time of flight of an acoustic signal emitted and reflected in a specific cavity. A piezoelectric transducer, driven by a pulse generator, generates the acoustic wave in the cavity. The piezoelectric transducer is a PZT ceramic disk, mainly consisting of lead, zirconium and titanium. This acoustic method was tested with success during a first experiment called REMORA 3, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. However, during the irradiation test, acoustic signal degradation was observed, mainly due to irradiation effect but also due to the increasing of the gas temperature. Despite this acoustic signal degradation, the time of flight measurements were carried out with good accuracy throughout the test, thanks to the development of a more efficient signal processing. After experiment, neutronic calculations were performed in order to determine neutron fluence at the level of the piezoelectric transducer. In order to have a better understanding of the acoustic sensor behavior under irradiation, Post Irradiation Examination program was done on piezoelectric transducer and on acoustic coupling material too. These examinations were also realized on a non-irradiated acoustic sensor built in the same conditions and with the same materials and the same

  5. Prostatic carcinoma: limited field irradiation

    International Nuclear Information System (INIS)

    Rounsaville, M.C.; Green, J.P.; Vaeth, J.M.; Purdon, R.P.; Heltzel, M.M.

    1987-01-01

    This is a retrospective study of 251 patients with histologically proven adenocarcinoma treated primarily with limited field radiotherapy techniques, under the principle direction of authors JMV and JPG, between 1968 and 1981 in San Francisco, California. All patients are followed for a minimum of 3 years; mean follow-up is 7.3 years. Routine clinical staging procedures included: HandP, digital prostate exam, cystoscopy, biopsy, blood studies including serum acid phosphatase, and imaging studies including chest X ray, IVP, bone survey or radionucleotide bone scan, and in recent years, pelvic CT scans. Twelve patients are Stage A1, 37-Stage A2, 50-Stage B, 140-Stage C1 and 12-Stage C2. Ninety percent of all cases and 85% of Stage C patients were treated with limited fields to the prostate and periprostatic volume only. Total doses were prescribed at midplane or isocenter and were generally 6500-7000 cGy, daily doses of 180-200 cGy, 5 days per week. Actuarial 5- and 10-year survival rates are: entire population-69% and 47%; Stage A1-74% and 50%; Stage A2-81% and 67%; Stage B-84% and 53%; Stage C1-63% and 42%; Stage C2-32% and 11%. The 5- and 10-year disease-free actuarial survivals are: entire population-71% and 50%; Stage A1-89% and 74%; Stage A2-82% and 69%; Stage B-71% and 52%; Stage C1-67% and 44%; Stage C2-0%. Sites of recurrence, alone or as a component of the failure pattern are: 37 (15%) local, 11 (4%) symptomatic regional recurrence (lower extremity edema, pelvic pain/sciatica, hydroureteronephrosis), and 87 (35%) distant metastasis. Seven (3%) had unknown sites of failure. Local-regional failure occurred in 42% of Stage C2 patients

  6. Prostatic biopsy after irradiation therapy for prostatic cancer

    International Nuclear Information System (INIS)

    Scardino, P.T.; Wheeler, T.M.

    1985-01-01

    To determine the prognostic significance of a routine needle biopsy of the prostate performed six to thirty-six months after the completion of definitive radiotherapy, biopsy results were analyzed in 146 patients who had no evidence of disease at the time of biopsy and who received no other therapy before proved recurrence of the tumor. Patients were followed up a mean of 3.9 years after radioactive gold seed implantation and external beam irradiation. The total dose was 8,000 rad. Among 146 patients, 56 (38%) had one or more positive biopsy results within this time interval. The positive biopsy rate correlated with the clinical stage ranging from 17 per cent in Stage B1N to 59 per cent in Stage C1. The risk of developing local recurrence or distant metastases at any given time after irradiation therapy was markedly greater in those patients with a positive biopsy result (p less than 0.0005). Prostatic biopsy is an accurate means of measuring the success of radiotherapy. A positive postirradiation biopsy result carries grave prognostic implications for the patient and indicates that the treatment has failed

  7. The effectiveness of immobilization during prostate irradiation

    International Nuclear Information System (INIS)

    Bentel, Gunilla C.; Marks, Lawrence B.; Sherouse, George W.; Spencer, David P.; Anscher, Mitchell S.

    1995-01-01

    Purpose: To evaluate the effect of a hemibody foam cradle on the reproducibility of patient setup during external beam radiation treatment of prostate cancer. Methods and Materials: Between January 1992 and April 1993, 74 patients received external beam radiation treatment to the prostate ± nodes, generally with a four-field box technique. Forty-four of the 74 patients had a custom-made hemibody foam cast used in an attempt to improve setup accuracy. A review of the routine weekly port films was performed following the completion of therapy to determine the reproducibility of patient setup in all 74 patients. The physician's request of an isocenter shift was used as an indicator of reproducibility. Neither the treating technologists nor the physicians knew at the time the films were taken that the port films would be reviewed for setup reproducibility at a later date. The results were compared between the patients treated with (44) and without (30) an immobilization device. Results: In the 44 immobilized patients, 213 routine checks of the isocenter were performed during the 7-week course of radiation therapy. In 17.4% of these instances (37 out of 213), an isocenter shift was requested. This rate is compared to 23.1% (30 out of 130) in the 30 patients who did not have the immobilization device (p < 0.2). There was a statistically significant reduction in isocenter shifts requested in the anterior to posterior direction in the patients who were immobilized, 5.1% (9 out of 175) vs. 12.6% (13 out of 103) (p < 0.05, two tailed chi-square test). There was no significant improvement in the reproducibility of isocenter placement in the cephalad to caudal or right to left directions. Conclusions: This custom-made hemibody foam cradle appears to improve the reproducibility of patient setup during the 7-week course of fractionated external beam irradiation for patients with adenocarcinoma of the prostate. This type of immobilization device is now routinely used in our

  8. Postoperative irradiation in carcinoma of the prostate

    International Nuclear Information System (INIS)

    Pilepich, M.V.; Walz, B.J.; Baglan, R.J.

    1984-01-01

    Twenty-eight patients received postoperative radiotherapy with curative intent following either radical prostatectomy (18 patients) or enucleative prostatectomy (10 patients). In patients undergoing radical prostatectomy, the indications for postoperative radiotherapy included positive margins in 13, close margins in 2, and seminal vesicle involvement in 3 patients. The majority of patients (82%) received total dose to the prostatic bed in excess of 6500 rad. In over 80% of the patients, the pelvic lymphatics are also treated (to a total dose of 4000-5000 rad). All of the patients irradiated after radical prostatectomy clinically remained disease-free locally. Approximately one-half of the patients in both the enucleation and radial prostatectomy groups developed evidence of distant metastases. The complications of treatment have been comparable to those in patients treated with radiotherapy only. The continence status has not been affected significantly. All patients with incontinence following completion of radiotherapy had documented impairment of continence prior to radiotherapy. Postoperative radiotherapy administered following either radical or enucleative prostatectomy was tolerated well and resulted in excellent local control

  9. Thermoacoustic contrast of prostate cancer due to heating by very high frequency irradiation

    International Nuclear Information System (INIS)

    Patch, S K; Hull, D; Thomas, M; Jacobsohn, K; See, WA; Griep, SK

    2015-01-01

    Applying the thermoacoustic (TA) effect to diagnostic imaging was first proposed in the 1980s. The object under test is irradiated by high-power pulses of electromagnetic energy, which heat tissue and cause thermal expansion. Outgoing TA pressure pulses are detected by ultrasound transducers and reconstructed to provide images of the object. The TA contrast mechanism is strongly dependent upon the frequency of the irradiating electromagnetic pulse. When very high frequency (VHF) electromagnetic irradiation is utilized, TA signal production is driven by ionic content. Prostatic fluids contain high levels of ionic metabolites, including citrate, zinc, calcium, and magnesium. Healthy prostate glands produce more ionic metabolites than diseased glands. VHF pulses are therefore expected to generate stronger TA signal in healthy prostate glands than in diseased glands. A benchtop system for performing ex vivo TA computed tomography with VHF energy is described and images are presented. The system utilizes irradiation pulses of 700 ns duration exceeding 20 kW power. Reconstructions frequently visualize anatomic landmarks such as the urethra and verumontanum. TA reconstructions from three freshly excised human prostate glands with little, moderate, and severe cancerous involvement are compared with histology. TA signal strength is negatively correlated with percent cancerous involvement in this small sample size. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity. This sample size is far too small to draw sweeping conclusions, but the results warrant a larger volume study including comparison of TA images to the gold standard, histology. (paper)

  10. Low-dose irradiation for controlling prostate cancer

    International Nuclear Information System (INIS)

    Cuttler, J.M.

    2003-01-01

    Prostate cancer is the second most commonly diagnosed cancer among North American men and the second leading cause of death in those aged 65 and over. The American Cancer Society recommends testing those over age 50 who are expected to live at least 10 years, even though the ability of early detection to decrease prostate cancer mortality has not been demonstrated. So controversy exists about the appropriateness of screening because of the considerable economic and social burden of diagnosing and treating prostate cancer, coupled with the projected large increase in the number of new cases as the population ages. This very important public health issue could be addressed at low cost by total-body low-dose irradiation therapy to stimulate the patient's own defences to prevent and control most cancers, including prostate cancer, with no symptomatic side effects. (author)

  11. Radical irradiation for carcinoma of the prostate | Abratt | South ...

    African Journals Online (AJOL)

    Ninety-three patients treated by radical irradiation for stage A2, Band C1 carcinoma of the prostate between 1979 and 1988 at a joint radiotherapy service were reviewed. The average age was 63 years, 84% of the patients were white and on histological examination the tumours were well or moderately differentiated in ...

  12. Prostate specific antigen levels after definitive irradiation for carcinoma of the prostate

    International Nuclear Information System (INIS)

    Schellhammer, P.F.; Schlossberg, S.M.; El-Mahdi, A.M.; Wright, G.L.; Brassil, D.N.

    1991-01-01

    Prostate specific antigen (PSA) levels were determined in 78 patients judged clinically to be free of disease at intervals of 36 or more months (range 38 to 186 months, median 87 months) after completion of irradiation therapy by 125-iodine implantation or external beam radiation. Of this select group of patients 38% had undetectable serum PSA levels (0.5 ng./ml. or less) and 38% had PSA levels that were within normal limits (4.0 ng./ml. or less). All stages and grades were represented. Undetectable PSA levels were only rarely found (3%) in patients with carcinoma of the prostate before treatment. In 24 of these 78 patients a negative biopsy of the irradiated prostate had been obtained 18 to 42 months after treatment. When the PSA level was drawn, which ranged from 7 to 16 years after treatment, an equal percentage of these biopsied patients had either an undetectable, normal or elevated level. Irradiation is able to decrease PSA to undetectable levels in some patients with prostatic carcinoma. Whether this reflects suppression of marker production alone or, more importantly, ablation of prostate cancer producing that marker remains to be determined

  13. Prostate cancer: experience with definitive irradiation in the aged

    International Nuclear Information System (INIS)

    Green, N.; Bodner, H.; Broth, E.

    1985-01-01

    When considering therapeutic options for localized prostate cancer, stage and grade of disease have been the most important determinants. In the elderly, the nominal age has assumed increasing importance in the final decision. A balanced judgment must be reached between the patient's normal life expectancy and the rapidity with which the cancer may be expected to express its malignant potential. By careful attention to patient selection and the details of treatment, definitive irradiation can improve quality of life and survival. Of 63 patients aged seventy-three to ninety years referred for irradiation, 56 were found medically suitable for definitive treatment. A review of the authors experience is presented

  14. Evaluation of Candidate Linear Variable Displacement Transducers for High Temperature Irradiations in the Advanced Test Reactor

    International Nuclear Information System (INIS)

    Knudson, D.L.; Rempe, J.L.; Daw, J.E.

    2009-01-01

    The United States (U.S.) Department of Energy (DOE) designated the Advanced Test Reactor (ATR) as a National Scientific User Facility (NSUF) in April 2007 to promote nuclear science and technology in the U.S. Given this designation, the ATR is supporting new users from universities, laboratories, and industry as they conduct basic and applied nuclear research and development to advance the nation's energy security needs. A fundamental component of the ATR NSUF program is to develop in-pile instrumentation capable of providing real-time measurements of key parameters during irradiation experiments. Dimensional change is a key parameter that must be monitored during irradiation of new materials being considered for fuel, cladding, and structures in next generation and existing nuclear reactors. Such materials can experience significant changes during high temperature irradiation. Currently, dimensional changes are determined by repeatedly irradiating a specimen for a defined period of time in the ATR and then removing it from the reactor for evaluation. The time and labor to remove, examine, and return irradiated samples for each measurement makes this approach very expensive. In addition, such techniques provide limited data (i.e., only characterizing the end state when samples are removed from the reactor) and may disturb the phenomena of interest. To address these issues, the Idaho National Laboratory (INL) recently initiated efforts to evaluate candidate linear variable displacement transducers (LVDTs) for use during high temperature irradiation experiments in typical ATR test locations. Two nuclear grade LVDT vendor designs were identified for consideration - a smaller diameter design qualified for temperatures up to 350 C and a larger design with capabilities to 500 C. Initial evaluation efforts include collecting calibration data as a function of temperature, long duration testing of LVDT response while held at high temperature, and the assessment of changes

  15. Interstitial gold and external beam irradiation for prostate cancer

    International Nuclear Information System (INIS)

    Boileau, M.A.; Dowling, R.A.; Gonzales, M.; Handel, P.H.; Benson, G.S.; Corriere, J.N. Jr.

    1988-01-01

    We treated 65 patients with prostatic cancer confined clinically to the prostate or periprostatic area during an 8-year period. Seven patients had stage A2, 38 stage B and 20 stage C disease. All 65 patients underwent staging pelvic lymphadenectomy and implantation of gold grains into the prostate (mean dose 3,167 rad). A total of 64 patients then completed a course of external beam irradiation to a mean total tumor dose of 6,965 rad. Complications of therapy were mild and limited (less than 3 months in duration) in most patients, and they included radiation cystitis (32 per cent), diarrhea (31 per cent), extremity lymphedema (7.7 per cent) and wound infection (3 per cent). Two patients suffered urinary incontinence after therapy and 2 (3 per cent) had diarrhea more than 3 months in duration. The actuarial 5-year survival rate for all patients was 87 per cent and the 5-year survival free of disease was 72 per cent

  16. SU-E-J-95: Predicting Treatment Outcomes for Prostate Cancer: Irradiation Responses of Prostate Cancer Stem Cells

    International Nuclear Information System (INIS)

    Wang, K

    2014-01-01

    Purpose: Most prostate cancers are slow-growing diseases but normally require much higher doses (80Gy) with conventional fractionation radiotherapy, comparing to other more aggressive cancers. This study is to disclose the radiobiological basis of this discrepancy by proposing the concept of prostate cancer stem cells (CSCs) and examining their specific irradiation responses. Methods: There are overwhelming evidences that CSC may keep their stemness, e.g. the competency of cell differentiation, in hypoxic microenvironments and hence become radiation resistive, though the probability is tiny for aggressiveness cancers. Tumor hypoxia used to be considered as an independent reason for poor treatment outcomes, and recent evidences showed that even prostate cancers were also hypoxic though they are very slow-growing. In addition, to achieve comparable outcomes to other much more aggressive cancers, much higher doses (rather than lower doses) are always needed for prostate cancers, regardless of its non-aggressiveness. All these abnormal facts can only be possibly interpreted by the irradiation responses characteristics of prostate CSCs. Results: Both normal cancer cells (NCCs) and CSCs exiting in tumors, in which NCCs are mainly for symptoms whereas killing all CSCs achieves disease-free. Since prostate cancers are slow-growing, the hypoxia in prostate cancers cannot possibly from NCCs, thus it is caused by hypoxic CSCs. However, single hypoxic cell cannot be imaged due to limitation of imaging techniques, unless a large group of hypoxic cells exist together, thus most of CSCs in prostate cancers are virtually hypoxic, i.e. not in working mode because CSCs in proliferating mode have to be normoxic, and this explains why prostate cancers are unaggressive. Conclusion: The fractional dose in conventional radiotherapy (∼2Gy) could only kill NCCs and CSCs in proliferating modes, whereas most CSCs survived fractional treatments since they were hypoxic, thus to eliminate all

  17. Analysis of competing risk parameters in irradiated prostate cancer patients

    International Nuclear Information System (INIS)

    Mayer, R.; Mayer, E.; Langsenlehner, U.; Hackl, A.; Pummer, K.; Quehenberger, F.; Feigl, G.

    2003-01-01

    Purpose: Retrospective competing risk analysis of prognostic factors in definitive-irradiated prostate cancer patients. Patients and Methods: Data of 652 patients were analyzed according to three age subgroups ( 75 years; Table 1). Pre-RT PSA values (median 13.4 ng/ml) were available for 340 patients. Adjuvant hormone therapy (n = 261) consisted either of orchiectomy (n = 151) or LHRH agonist with/without antiandrogen therapy or, in the early years, diethystilbestrol. Neoadjuvant hormone therapy (n = 31) using LHRH agonists was given 6 months before and during radiotherapy. Results: Biochemical failure was observed in 69/.340 patients, 5 years after biochemical failure, 64.9% of them also had failed clinically. The cumulative incidence of local failure (LF) and distant metastases (DM) was 9.4% and 37.2%, respectively; LF and DM at the same time were seen in 18.2%. On multivariate analysis (Tables 2 and 3), advanced stage (relative risk [RR] 4.54), pre-RT PSA > 20 ng/ml (RR 2.79) and poorly differentiated tumors (RR 2.96) were significant predictors of biochemical failure. Advanced stage increased the risk of LF (RR 2.18), DM (RR 3.66), and prostate cancer death (PCD; RR 4.30). Hormone therapy decreased the risk of biochemical failure (RR 0.67), DM (RR 0.59), and PCD (RR 0.60) without reaching statistical significance. Median follow-up was 7.6 years. Conclusion: Risk of biochemical failure was predicted by pre-RT PSA, stage, and grade; in patients with biochemical failure, the cumulative incidence of death from intercurrent diseases and PCD was 25.0% and 29.2% after 5 years, respectively. The risk of DM and PCD was predicted by stage and grade. Higher age (> 75 years) decreased the relative risk of LF, DM, and PCD significantly. (orig.)

  18. 103PD brachytherapy and external beam irradiation for clinically localized, high-risk prostatic carcinoma

    International Nuclear Information System (INIS)

    Dattoli, Michael; Wallner, Kent; Sorace, Richard; Koval, John; Cash, Jennifer; Acosta, Rudolph; Brown, Charles; Etheridge, James; Binder, Michael; Brunelle, Richard; Kirwan, Novelle; Sanchez, Servando; Stein, Douglas; Wasserman, Stuart

    1996-01-01

    Purpose: To summarize biochemical failure rates and morbidity of external beam irradiation (EBRT) combined with palladium ( 103 Pd) boost for clinically localized high-risk prostate carcinoma. Methods and Materials: Seventy-three consecutive patients with stage T2a-T3 prostatic carcinoma were treated from 1991 through 1994. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (71 patients), Gleason score 7-10 (40 patients), prostate specific antigen (PSA) >15 (32 patients), or elevated prostatic acid phosphatase (PAP) (17 patients). Patients received 41 Gy EBRT to a limited pelvic field, followed 4 weeks later by a 103 Pd boost (prescription dose: 80 Gy). Biochemical failure was defined as a PSA greater than 1.0 ng/ml (normal 103 Pd brachytherapy for clinically localized, high-risk prostate cancer compare favorably with that reported after conventional dose EBRT alone. Morbidity has been acceptable

  19. Potential benefits of combining cytosine deaminase/5-fluorocytosine gene therapy and irradiation for prostate cancer. Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Hiroaki; Koshida, Kiyoshi; Yokoyama, Kunihiko; Mizokami, Atsushi; Namiki, Mikio [Kanazawa Univ. (Japan). School of Medicine

    2002-10-01

    The purpose of this study was to investigate the potential of combining cytosine deaminase/5-fluorocytosine (CD/5-FC) gene therapy and radiation therapy (either external beam radiation or radioimmunotherapy [RIT]), for the treatment of prostate cancer. Tumor xenografts of CD-transduced LNCaP cells grown in the testes of severe combined immunodeficiency (SCID) mice were used to evaluate antitumor effect. The mice were injected intraperitoneally with 500 mg/kg of 5-FC, or with 5, 15 or 30 mg/kg of 5-fluorouracil (5-FU), for 9 days. The tumors were treated with fractionated radiation at a dose of 1 or 3 Gy/day for 3 days, or I-131 labelled anti-prostate specific antigen (anti-PSA) monoclonal antibody (mAb) administration at a subtherapeutic dose of 20 or 80 {mu}Ci. Intratumoral and serum concentrations of 5-FU were measured using high performance liquid chromatography. Mice treated with CD/5-FC gene therapy presented a significant tumor growth inhibition comparable to that obtained with 15 mg/kg, 5-FU systemic administration without marked weight loss. Treatment with CD/5-FC gene therapy resulted in higher tumor but lower serum concentrations of 5-FU than treatment with systemic 5-FU chemotherapy. An additive antitumor effect was obtained when CD/5-FC therapy was combined with 1 Gy irradiation, which by itself did not produce a significant antitumor effect. However, the efficacy of CD/5-FC therapy was not enhanced when combined with RIT, probably due to poor accumulation of the mAb as the tumor/blood ratio never exceeded 1. These findings indicate that CD/5-FC gene therapy for prostate cancer may function with enhanced antitumor effect when combined with external beam radiation. However, combining CD/5-FC gene therapy and RIT using an anti-PSA mAb may not be effective because of insufficient accumulation of the mAb at the target tumors. (author)

  20. Potential benefits of combining cytosine deaminase/5-fluorocytosine gene therapy and irradiation for prostate cancer. Experimental study

    International Nuclear Information System (INIS)

    Kato, Hiroaki; Koshida, Kiyoshi; Yokoyama, Kunihiko; Mizokami, Atsushi; Namiki, Mikio

    2002-01-01

    The purpose of this study was to investigate the potential of combining cytosine deaminase/5-fluorocytosine (CD/5-FC) gene therapy and radiation therapy (either external beam radiation or radioimmunotherapy [RIT]), for the treatment of prostate cancer. Tumor xenografts of CD-transduced LNCaP cells grown in the testes of severe combined immunodeficiency (SCID) mice were used to evaluate antitumor effect. The mice were injected intraperitoneally with 500 mg/kg of 5-FC, or with 5, 15 or 30 mg/kg of 5-fluorouracil (5-FU), for 9 days. The tumors were treated with fractionated radiation at a dose of 1 or 3 Gy/day for 3 days, or I-131 labelled anti-prostate specific antigen (anti-PSA) monoclonal antibody (mAb) administration at a subtherapeutic dose of 20 or 80 μCi. Intratumoral and serum concentrations of 5-FU were measured using high performance liquid chromatography. Mice treated with CD/5-FC gene therapy presented a significant tumor growth inhibition comparable to that obtained with 15 mg/kg, 5-FU systemic administration without marked weight loss. Treatment with CD/5-FC gene therapy resulted in higher tumor but lower serum concentrations of 5-FU than treatment with systemic 5-FU chemotherapy. An additive antitumor effect was obtained when CD/5-FC therapy was combined with 1 Gy irradiation, which by itself did not produce a significant antitumor effect. However, the efficacy of CD/5-FC therapy was not enhanced when combined with RIT, probably due to poor accumulation of the mAb as the tumor/blood ratio never exceeded 1. These findings indicate that CD/5-FC gene therapy for prostate cancer may function with enhanced antitumor effect when combined with external beam radiation. However, combining CD/5-FC gene therapy and RIT using an anti-PSA mAb may not be effective because of insufficient accumulation of the mAb at the target tumors. (author)

  1. Prostatic irradiation is not associated with any measurable increase in the risk of subsequent rectal cancer

    International Nuclear Information System (INIS)

    Kendal, Wayne S.; Eapen, Libni; MacRae, Robert; Malone, Shawn; Nicholas, Garth

    2006-01-01

    Purpose: To investigate a putative increased risk of rectal cancer subsequent to prostatic radiotherapy. Methods and Materials: In an analysis of the Surveillance, Epidemiology, and End Results registry, we compared men who had radiotherapy for prostatic carcinoma with those treated surgically and those treated with neither modality. Kaplan-Meier analyses for the time to failure from rectal cancer were performed between age-matched subgroups of the three cohorts. Cox proportional hazards analyses were performed to ascertain what influences might affect the incidence of subsequent rectal cancer. Results: In all, 33,831 men were irradiated, 167,607 were treated surgically, and 36,335 received neither modality. Rectal cancers developed in 243 (0.7%) of those irradiated (mean age, 70.7 years), 578 (0.3%) of those treated surgically (68.7 years), and 227 (0.8%) of those treated with neither modality (74.2 years). When age effects and the differences between the surgical and untreated cohorts were controlled for, we were unable to demonstrate any significant increased incidence of rectal cancer in men irradiated for prostatic cancer. Conclusions: An increased frequency of rectal cancer after prostatic irradiation, apparent on crude analysis, could be attributed to age confounding and other unmeasured confounders associated with prostate cancer treatment and rectal cancer risk

  2. Role of choline PET/CT in guiding target volume delineation for irradiation of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzenboeck, S.M.; Kurth, J. [University Medical Centre Rostock, Department of Nuclear Medicine, Rostock (Germany); Gocke, C.; Kuhnt, T.; Hildebrandt, G. [University Medical Centre Rostock, Department of Radiotherapy, Rostock (Germany); Krause, B.J. [University Medical Centre Rostock, Department of Nuclear Medicine, Rostock (Germany); Universitaet Rostock, Department of Nuclear Medicine, Universitaetsmedizin Rostock, Rostock (Germany)

    2013-07-15

    Choline PET/CT has shown limitations for the detection of primary prostate cancer and nodal metastatic disease, mainly due to limited sensitivity and specificity. Conversely in the restaging of prostate cancer recurrence, choline PET/CT is a promising imaging modality for the detection of local regional and nodal recurrence with an impact on therapy management. This review highlights current literature on choline PET/CT for radiation treatment planning in primary and recurrent prostate cancer. Due to limited sensitivity and specificity in differentiating between benign and malignant prostatic tissues in primary prostate cancer, there is little enthusiasm for target volume delineation based on choline PET/CT. Irradiation planning for the treatment of single lymph node metastases on the basis of choline PET/CT is controversial due to its limited lesion-based sensitivity in primary nodal staging. In high-risk prostate cancer, choline PET/CT might diagnose lymph node metastases, which potentially can be included in the conventional irradiation field. Prior to radiation treatment of recurrent prostate cancer, choline PET/CT may prove useful for patient stratification by excluding distant disease which would require systemic therapy. In patients with local recurrence, choline PET/CT can be used to delineate local sites of recurrence within the prostatic resection bed allowing a boost to PET-positive sites. In patients with lymph node metastases outside the prostatic fossa and regional metastatic lymph nodes, choline PET/CT might influence radiation treatment planning by enabling extension of the target volume to lymphatic drainage sites with or without a boost to PET-positive lymph nodes. Further clinical randomized trials are required to assess treatment outcomes following choline-based biological radiation treatment planning in comparison with conventional radiation treatment planning. (orig.)

  3. Studies on 192Ir afterloading irradiation of the canine prostate with special consideration of thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Reuter, M.

    1986-01-01

    A method for high dose rate afterloading irradiation of the prostate with iridium 192 was developed. The isodoses of the urethra and rectum, which were measured by means of thermoluminescent dosimetry, showed deviations from the doses pre-calculated by computer (BRACHY), because this calculation is based on an anatomically ideal condition. (MBC) [de

  4. Metastasizing, Luciferase Transduced MAT-Lu Rat Prostate Cancer Models: Follow up of Bolus and Metronomic Therapy with Doxorubicin as Model Drug

    International Nuclear Information System (INIS)

    Jantscheff, Peter; Esser, Norbert; Geipel, Andreas; Woias, Peter; Ziroli, Vittorio; Goldschmidtboing, Frank; Massing, Ulrich

    2011-01-01

    The most fatal outcomes of prostate carcinoma (PCa) result from hormone-refractory variants of the tumor, especially from metastatic spread rather than from primary tumor burden. The goal of the study was to establish and apply rat MAT-Lu prostate cancer tumor models for improved non-invasive live follow up of tumor growth and metastasis by in vivo bioluminescence. We established luciferase transduced MAT-Lu rat PCa cells and studied tumor growth and metastatic processes in an ectopic as well as orthotopic setting. An intravenous bolus treatment with doxorubicin was used to demonstrate the basic applicability of in vivo imaging to follow up therapeutic intervention in these models. In vitro analysis of tissue homogenates confirmed major metastatic spread of subcutaneous tumors into the lung. Our sensitive method, however, for the first time detects metastasis also in lymph node (11/24), spleen (3/24), kidney (4/24), liver (5/24), and bone tissue (femur or spinal cord - 5/20 and 12/20, respectively). Preliminary data of orthotopic implantation (three animals) showed metastatic invasion to investigated organs in all animals but with varying preference (e.g., to lymph nodes). Intravenous bolus treatment of MAT-Lu PCa with doxorubicin reduced subcutaneous tumor growth by about 50% and the number of animals affected by metastatic lesions in lymph nodes (0/4), lung (3/6) or lumbar spine (0/2), as determined by in vivo imaging and in vitro analysis. Additionally, the possible applicability of the luciferase transduced MAT-Lu model(s) to study basic principles of metronomic therapies via jugular vein catheter, using newly established active microport pumping systems, is presented

  5. Metastasizing, Luciferase Transduced MAT-Lu Rat Prostate Cancer Models: Follow up of Bolus and Metronomic Therapy with Doxorubicin as Model Drug

    Energy Technology Data Exchange (ETDEWEB)

    Jantscheff, Peter, E-mail: jantscheff@tumorbio.uni-freiburg.de [Tumour Biology Center, Clinical Research, Department Lipids & Liposomes, Breisacher Str.117, D-79106 Freiburg (Germany); Esser, Norbert [ProQinase GmbH, Breisacher Str. 117, D-79106 Freiburg (Germany); Geipel, Andreas; Woias, Peter [Laboratory for Design of Microsystems, Department of Microsystems Engineering (IMTEK), Georges-Köhler-Allee 106, D-79110 Freiburg (Germany); Ziroli, Vittorio [Tumour Biology Center, Clinical Research, Department Lipids & Liposomes, Breisacher Str.117, D-79106 Freiburg (Germany); Goldschmidtboing, Frank [Laboratory for Design of Microsystems, Department of Microsystems Engineering (IMTEK), Georges-Köhler-Allee 106, D-79110 Freiburg (Germany); Massing, Ulrich [Tumour Biology Center, Clinical Research, Department Lipids & Liposomes, Breisacher Str.117, D-79106 Freiburg (Germany)

    2011-06-17

    The most fatal outcomes of prostate carcinoma (PCa) result from hormone-refractory variants of the tumor, especially from metastatic spread rather than from primary tumor burden. The goal of the study was to establish and apply rat MAT-Lu prostate cancer tumor models for improved non-invasive live follow up of tumor growth and metastasis by in vivo bioluminescence. We established luciferase transduced MAT-Lu rat PCa cells and studied tumor growth and metastatic processes in an ectopic as well as orthotopic setting. An intravenous bolus treatment with doxorubicin was used to demonstrate the basic applicability of in vivo imaging to follow up therapeutic intervention in these models. In vitro analysis of tissue homogenates confirmed major metastatic spread of subcutaneous tumors into the lung. Our sensitive method, however, for the first time detects metastasis also in lymph node (11/24), spleen (3/24), kidney (4/24), liver (5/24), and bone tissue (femur or spinal cord - 5/20 and 12/20, respectively). Preliminary data of orthotopic implantation (three animals) showed metastatic invasion to investigated organs in all animals but with varying preference (e.g., to lymph nodes). Intravenous bolus treatment of MAT-Lu PCa with doxorubicin reduced subcutaneous tumor growth by about 50% and the number of animals affected by metastatic lesions in lymph nodes (0/4), lung (3/6) or lumbar spine (0/2), as determined by in vivo imaging and in vitro analysis. Additionally, the possible applicability of the luciferase transduced MAT-Lu model(s) to study basic principles of metronomic therapies via jugular vein catheter, using newly established active microport pumping systems, is presented.

  6. Metastasizing, Luciferase Transduced MAT‑Lu Rat Prostate Cancer Models: Follow up of Bolus and Metronomic Therapy with Doxorubicin as Model Drug

    Directory of Open Access Journals (Sweden)

    Peter Woias

    2011-06-01

    Full Text Available The most fatal outcomes of prostate carcinoma (PCa result from hormone-refractory variants of the tumor, especially from metastatic spread rather than from primary tumor burden. The goal of the study was to establish and apply rat MAT-Lu prostate cancer tumor models for improved non-invasive live follow up of tumor growth and metastasis by in vivo bioluminescence. We established luciferase transduced MAT-Lu rat PCa cells and studied tumor growth and metastatic processes in an ectopic as well as orthotopic setting. An intravenous bolus treatment with doxorubicin was used to demonstrate the basic applicability of in vivo imaging to follow up therapeutic intervention in these models. In vitro analysis of tissue homogenates confirmed major metastatic spread of subcutaneous tumors into the lung. Our sensitive method, however, for the first time detects metastasis also in lymph node (11/24, spleen (3/24, kidney (4/24, liver (5/24, and bone tissue (femur or spinal cord - 5/20 and 12/20, respectively. Preliminary data of orthotopic implantation (three animals showed metastatic invasion to investigated organs in all animals but with varying preference (e.g., to lymph nodes. Intravenous bolus treatment of MAT-Lu PCa with doxorubicin reduced subcutaneous tumor growth by about 50% and the number of animals affected by metastatic lesions in lymph nodes (0/4, lung (3/6 or lumbar spine (0/2, as determined by in vivo imaging and in vitro analysis. Additionally, the possible applicability of the luciferase transduced MAT-Lu model(s to study basic principles of metronomic therapies via jugular vein catheter, using newly established active microport pumping systems, is presented.

  7. Prostatitis

    Science.gov (United States)

    Prostatitis Overview Prostatitis is swelling and inflammation of the prostate gland, a walnut-sized gland situated directly below the bladder in ... produces fluid (semen) that nourishes and transports sperm. Prostatitis often causes painful or difficult urination. Other symptoms ...

  8. Local control and survival after external irradiation for adenocarcinoma of the prostate

    International Nuclear Information System (INIS)

    Rangala, N.; Cox, J.D.; Byhardt, R.W.; Wilson, J.F.; Greenberg, M.; Conceicao, A.L.D.

    1982-01-01

    From 1966 through 1978, 128 patients with biopsy-proven adenocarcinoma of the prostate underwent external irradiation to the entire pelvis followed by additional irradiation with a field that encompassed the entire prostate with generous margins. Local recurrence was diagnosed when palpable regrowth occurred and was confirmed by biopsy. Eighteen patients (14%) had local recurrence. Actuarial (life table) local recurrence rates, however, were 24% for both for Stage B and C patients. Actuarial five year survival was 100% for the 10 Stage A patients, 91% for the 25 Stage B, and 78% for the 93 Stage C patients. Actuarial five year disease-free survival was 59% for Stage B and 69% for Stage C patients. Local recurrence was affected by the total dose to the whole pelvis and the dose at the center of the prostate. Disease-free survival was influenced by differentiation. High dose external irradiation to the prostate and regional lymph nodes offers the greatest probability of long-term disease-free survival for patients with localized disease. Late bowel complications were seen in 14 patients (11%), two of whom required colostomies. Late urinary tract complications were observed in five patients (4%)

  9. Long term results of ultrasonically guided implantation of 125-I seeds combined with external irradiation in localized prostatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Iversen, P; Rasmussen, F; Holm, H H [Depts. of Urology and Ultrasound, Herlev Hospital, Univ. of Copenhagen (Denmark)

    1991-01-01

    Transperineal 125-iodine seed implantation guided by transrectal ultrasonography and subsequent external beam irradiation was employed in the treatment of 32 patients with localized prostatic carcinoma (16 poorly differentiated). Follow-up is currently 35-98 months with a median of 65 months. Distant metastases have developed in 18 patients, of whom 11 have died from prostatic cancer. Median change in prostatic volume was a reduction of 35%. Re-biopsy or transurethral resection of the prostate was performed in 25 patients after 1-4 years, revealing still malignant histology in 10 (40%), of whom 8 have developed distant metastases or died from prostatic cancer. Fourteen patients suffered from late complications of which surgical intervention was indicated in five cases. Nine patients are presently free of progression and prostate specific antigen is bigger than 0.5 ng/ml in 8 of these. The future role of ultrasonically guided implantation in the management of prostatic cancer is discussed. (au).

  10. Prostate-specific antigen for pretreatment prediction and posttreatment evaluation of outcome after definitive irradiation for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kuban, Deborah A; El-Mahdi, Anas M; Schellhammer, Paul F

    1995-05-15

    Purpose: This study was undertaken to assess the predictive value of pretreatment prostate-specific antigen (PSA) and the difference between clinical and PSA disease-free status in patients with long-term follow-up after irradiation for prostatic carcinoma. Comparison of the distribution of prognostic factors between surgical and radiation series was also made. Methods and Materials: From 1975-1989, 652 patients with clinical Stage A2-C prostatic adenocarcinoma were definitively irradiated using external beam therapy. One hundred and fifty patients with banked serum and up to 14 years follow-up have pretreatment PSA levels and 355 patients with up to 17 years follow-up have posttreatment values. Treatment failure was analyzed by tumor stage, grade, and four pretreatment PSA categories. Disease-progression was evaluated by clinical and biochemical (PSA) endpoints. Prognostic factors were compared to two surgical series. Results: A significant difference was seen in clinical and PSA disease-free (PSA {<=} 4.0 ng/ml) status based on tumor grade, stage, and pretreatment PSA category. Although the expected clinical outcome has been well-documented previously, results based on posttreatment PSA levels show 5-year disease-free survivals reduced by 10-16% and 10-year survivals lessened by 15-39% depending upon the particular tumor grade and stage. The earlier stage, lower grade tumors showed the largest difference between clinical and biochemical recurrence rates at the longest interval from treatment. Even more notable were the differences in the clinical and PSA disease-free rates based on the pretreatment PSA level. Comparing the irradiated patients to two surgical series showed that the former had a larger percentage of more advanced stage tumors with more unfavorable PSA levels as compared to prostatectomy patients. Conclusion: With long-term follow-up, the pretreatment PSA level continues to be a powerful predictor of clinical and biochemical outcome in patients

  11. Daily CT planning during boost irradiation of prostate cancer. Feasibility and time requirements

    International Nuclear Information System (INIS)

    Geinitz, H.; Zimmermann, F.B.; Kuzmany, A.; Kneschaurek, P.

    2000-01-01

    Background: In the irradiation of prostate cancer internal organ movement leads to uncertainties in the daily localization of the clinical target volume. Therefore more or less large safety margins are added when designing the treatment portals. With daily CT planning internal organ movement can be compensated to some extent, safety margins can be reduced and irradiated normal tissue can be spared. The feasibility of daily CT-based 3D treatment planning is studied in a patient with localized prostate carcinoma using a new patient positioning system. Methods: Daily CT planning was applied during boost irradiation of a patient with prostate cancer: After patient immobilization the pelvis was scanned in 3 mm CT slices. Planning was done with the BrainSCAN planning system for stereotactic body irradiation. The prostate was contoured in all slices and the safety margins of the micromultileafs were automatically set to the distance chosen by the physician (0.8 cm). Patient positioning was done with the BrainLAB ExacTrac positioning system on the basis of skin attached stereotactic body markers. Before each treatment verification images of the isocenter were taken. Results: The total time requirement for planning and irradiation was about 1 hour 15 minutes. Patient positioning on the treatment couch took about 10 minutes. The accuracy of the positioning system was good (75% of the deviations were smaller than 3 mm). The shift of the single markers from CT scan to CT scan was more extensive than those of the center of all 7 markers combined (47% of the deviations were smaller than 3 mm). The location of the markers seems to influence the magnitude of their dislocation. Conclusion: Daily CT planning is feasible but time consuming. The new patient positioning system ExacTrac is an interesting tool especially for daily CT planning since conventional simulation can be omitted. (orig.) [de

  12. Half-body irradiation in the treatment of metastatic prostatic carcinoma

    International Nuclear Information System (INIS)

    Rowland, C.G.; Bullimore, J.A.; Smith, P.J.B.; Roberts, J.B.M.

    1981-01-01

    High dose radiation therapy given as a single fraction to the upper and lower halves of the body gives effective palliation for metastatic solid tumours. This treatment modality appears to be particularly effective in tumours which may have a slow doubling time such as carcinoma of the prostate. Fifty-two patients with metastatic carcinoma of the prostate involving the skeletal system have received half-body irradiation (8 MeV X-rays at a dose rate of about 100 cGy/min). All had prior treatment with additive hormones or orchiectomy and the majority had received localised irradiation and/or chemotherapy. Significant immediate pain relief was achieved in 42 out of 52 patients (80%). This pain relief was maintained until death in 29 out of 43 patients (67%). Pain relief in responders appears to occur within 24 to 48 h of treatment. (author)

  13. Adjuvant and salvage irradiation following radical prostatectomy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Morris, M M; Dallow, K C; Zietman, A L; Althausen, A F; Heney, N M; McGovern, F J; Shipley, W U

    1995-07-01

    Purpose: To assess the ability of adjuvant irradiation to prevent PSA failure in cases of pT3N0 disease, and of salvage irradiation to durably suppress a rising PSA following radical prostatectomy. Methods and Materials: 62 patients treated by post-operative radiation therapy (60-64Gy in 1.8Gy fractions to the tumor bed) between 1988 and 1993 were evaluated. All had complete pre- and post-radiation PSA data. Median follow up was 3.2 years from time of surgery and 2.2 years from irradiation. 20 patients had Gleason grade 3 disease (moderately differentiated) and 41 Gleason 4-5 (poorly differentiated). 46 had positive inked surgical margins, 18 involved seminal vesicles and 5 had palpable recurrent disease. None had known nodal or metastatic disease. 32 patients underwent adjuvant treatment (undetectable PSA at time of irradiation) and 30 salvage (detectable PSA at time of irradiation). Kaplan-Meier life table analysis was employed. The endpoint studied was freedom from biochemical failure. This was defined as a rise in the PSA of greater than 10% (intra laboratory error <8%) or a previously undetectable PSA becoming detectable. Results: The overall actuarial freedom from biochemical failure at 4 years from radiotherapy was 59%. A significant difference was seen between those receiving adjuvant and those receiving salvage irradiation (71% vs 51%, p=0.03). Amongst those in the salvage group neither the PSA prior to surgery, the PSA at the time of irradiation, the seminal vesicle status, nor the Gleason score (3 vs 4-5) correlated significantly with outcome. The time interval between surgery and irradiation was, however, significant. Those being treated within 6 months fared better than those treated later (60% vs 36%, p=0.04). Further, those treated early were more likely to achieve an undetectable nadir PSA level (94% vs 71%). Conclusion: The addition of adjuvant irradiation appears to improve the 4 year biochemical disease-free survival of patients with poor

  14. Offline multiple adaptive planning strategy for concurrent irradiation of the prostate and pelvic lymph nodes

    International Nuclear Information System (INIS)

    Qi, Peng; Xia, Ping; Pouliot, Jean; Roach, Mack

    2014-01-01

    Purpose: Concurrent irradiation of the prostate and pelvic lymph nodes (PLNs) can be challenging due to the independent motion of the two target volumes. To address this challenge, the authors have proposed a strategy referred to as Multiple Adaptive Planning (MAP). To minimize the number of MAP plans, the authors’ previous work only considered the prostate motion in one major direction. After analyzing the pattern of the prostate motion, the authors investigated a practical number of intensity-modulated radiotherapy (IMRT) plans needed to accommodate the prostate motion in two major directions simultaneously. Methods: Six patients, who received concurrent irradiation of the prostate and PLNs, were selected for this study. Nine MAP-IMRT plans were created for each patient with nine prostate contours that represented the prostate at nine locations with respect to the PLNs, including the original prostate contour and eight contours shifted either 5 mm in a single anterior-posterior (A-P), or superior-inferior (S-I) direction, or 5 mm in both A-P and S-I directions simultaneously. From archived megavoltage cone beam CT (MV-CBCT) and a dual imaging registration, 17 MV-CBCTs from 33 available MV-CBCT from these patients showed large prostate displacements (>3 mm in any direction) with respect to the pelvic bones. For each of these 17 fractions, one of nine MAP-IMRT plans was retrospectively selected and applied to the MV-CBCT for dose calculation. For comparison, a simulated isocenter-shifting plan and a reoptimized plan were also created for each of these 17 fractions. The doses to 95% (D95) of the prostate and PLNs, and the doses to 5% (D5) of the rectum and bladder were calculated and analyzed. Results: For the prostate, D95 > 97% of the prescription dose was observed in 16, 16, and 17 of 17 fractions for the MAP, isocenter-shifted, and reoptimized plans, respectively. For PLNs, D95 > 97% of the prescription doses was observed in 10, 3, and 17 of 17 fractions for

  15. A method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy

    International Nuclear Information System (INIS)

    Lu Yong; Song, Paul Y.; Li Shidong; Spelbring, Danny R.; Vijayakumar, Srinivasan; Haraf, Daniel J.; Chen, George T.Y.

    1995-01-01

    Purpose: To develop a method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy. Methods and Materials: Dose-surface histograms of the rectum, which state the rectal surface area irradiated to any given dose, were calculated for a group of 27 patients treated with a four-field box technique to a total (tumor minimum) dose ranging from 68 to 70 Gy. Occurrences of rectal toxicities as defined by the Radiation Therapy Oncology Group (RTOG) were recorded and examined in terms of dose and rectal surface area irradiated. For a specified end point of rectal complication, the complication probability was analyzed as a function of dose irradiated to a fixed rectal area, and as a function of area receiving a fixed dose. Lyman's model of normal tissue complication probability (NTCP) was used to fit the data. Results: The observed occurrences of rectal complications appear to depend on the rectal surface area irradiated to a given dose level. The patient distribution of each toxicity grade exhibits a maximum as a function of percentage surface area irradiated, and the maximum moves to higher values of percentage surface area as the toxicity grade increases. The dependence of the NTCP for the specified end point on dose and percentage surface area irradiated was fitted to Lyman's NTCP model with a set of parameters. The curvature of the NTCP as a function of the surface area suggests that the rectum is a parallel structured organ. Conclusions: The described method of analyzing rectal surface area irradiated yields interesting insight into understanding rectal complications in prostate conformal radiotherapy. Application of the method to a larger patient data set has the potential to facilitate the construction of a full dose-surface-complication relationship, which would be most useful in guiding clinical practice

  16. Long-term results of ultrasonically guided implantation of 125-I seeds combined with external irradiation in localized prostatic cancer

    DEFF Research Database (Denmark)

    Iversen, P; Rasmussen, F; Holm, H H

    1991-01-01

    Transperineal 125-iodine seed implantation guided by transrectal ultrasonography and subsequent external beam irradiation was employed in the treatment of 32 patients with localized prostatic carcinoma (16 poorly differentiated). Follow-up is currently 35-98 months with a median of 65 months....... Distant metastases have developed in 18 patients, of whom 11 have died from prostatic cancer. Median change in prostatic volume was a reduction of 35%. Re-biopsy or transurethral resection of the prostate was performed in 25 patients after 1-4 years, revealing still malignant histology in 10 (40......%), of whom 8 have developed distant metastases or died from prostatic cancer. Fourteen patients suffered from late complications of which surgical intervention was indicated in five cases. Nine patients are presently free of progression and prostate specific antigen is less than 0.5 ng/ml in 8 of these...

  17. Long-term results of ultrasonically guided implantation of 125-I seeds combined with external irradiation in localized prostatic cancer

    DEFF Research Database (Denmark)

    Iversen, P; Rasmussen, F; Holm, H H

    1991-01-01

    %), of whom 8 have developed distant metastases or died from prostatic cancer. Fourteen patients suffered from late complications of which surgical intervention was indicated in five cases. Nine patients are presently free of progression and prostate specific antigen is less than 0.5 ng/ml in 8 of these......Transperineal 125-iodine seed implantation guided by transrectal ultrasonography and subsequent external beam irradiation was employed in the treatment of 32 patients with localized prostatic carcinoma (16 poorly differentiated). Follow-up is currently 35-98 months with a median of 65 months....... Distant metastases have developed in 18 patients, of whom 11 have died from prostatic cancer. Median change in prostatic volume was a reduction of 35%. Re-biopsy or transurethral resection of the prostate was performed in 25 patients after 1-4 years, revealing still malignant histology in 10 (40...

  18. Does prostate brachytherapy treat the seminal vesicles? A dose-volume histogram analysis of seminal vesicles in patients undergoing combined PD-103 prostate implantation and external beam irradiation

    International Nuclear Information System (INIS)

    Stock, Richard G.; Lo, Yeh-Chi; Gaildon, Mohamoud; Stone, Nelson N.

    1999-01-01

    Purpose: Combined brachytherapy of the prostate and external beam irradiation (EBRT) of the prostate and seminal vesicles (SV) is becoming a popular treatment for high-risk prostate cancer. Dose-volume histogram (DVH) analysis of the SV in patients undergoing this treatment was performed to determine the dose distribution to the SV and the adequacy of this treatment in patients with potential SV involvement. Methods and Materials: Twenty-five consecutive patients were treated with a Pd-103 implant of the prostate alone and 45 Gy of EBRT to the prostate and SV. Attempts were not made to implant the SV but seeds were routinely placed at the junction of the prostate and SV. All patients underwent CT-based post implant dosimetric analysis 1 month after implantation. As part of this analysis, DVH were generated for the prostate and total SV volume (SVT). In addition, the SV was divided into 6-mm-thick volumes identified as SV1, SV2, SV3, SV4, and SV5 starting from the junction of the prostate and SV and extending distally. DVH were also generated for these structures. Delivered dose was defined as the D90 (dose delivered to 90% of the organ on DVH). Results: The median volumes in cc of the prostate, SVT, SV1, SV2, SV3, SV4, and SV5 were 34.33, 9.75, 2.7, 3.48, 2.92, 3.18, and 1.96 respectively. The SVT contained from 0-9 seeds (median 2). There was little dose delivered to the SVT and SV volumes from the implanted prostate. The median D90 values for the prostate, SVT, SV1, SV2, SV3, SV4, and SV5 were 8615 cGy, 675 cGy, 3100 cGy, 1329 cGy, 553 cGy, 246 cGy, and 67 cGy, respectively. The dose delivered to the prostate covered small percentages of SV. The percents of SV volumes covered by the prostate D90 were 11, 35, 3.3, 0, 0, and 0 for SVT, SV1, SV2, SV3, SV4, and SV5, respectively. Conclusions: DVH analysis of the SV reveals that dose generated from an implanted prostate contributes little to the SV. Those patients at high risk for SV involvement may be under treated

  19. Locally advanced prostatic cancer: experience with combined pelvic external beam irradiation and interstitial thermobrachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, Steven L; Kapp, Daniel S; Goffinet, Don R; Prionas, Stavros; Cox, Richard S; Bagshaw, Malcolm A

    1995-07-01

    Purpose: Recurrence of prostatic carcinoma within the prostate gland remains a significant problem for patients who present with locally advanced disease. In an attempt to improve the local control of such tumors, an iridium-192 transperineal, template-guided prostatic implant was combined wit radiofrequency-induced hyperthermia after external beam irradiation of the pelvic lymph nodes and prostate gland. This study evaluates the influence of pre-treatment patient characteristics and treatment parameters upon outcome. Materials and Methods: Between July 1987 and April 1992 33 patients with adenocarcinoma of the prostate were selected for treatment: 28 of these patients had extensive local disease on clinical examination (AJCC-4 stages T2b or c: 9 patients; T3: 19 patients); two patients with T2a tumors had Gleason grade 5 + 4 disease or disproportionately high prostate specific antigen (PSA) values and a mass encroaching upon the bladder on computerized tomographic scan. Three patients with more clinically limited T2a or T2b involvement elected implantation in lieu of an external beam irradiation boost. The mean pre-treatment serum PSA value was 25.6 ng/ml (Hybritech scale), with values of above 19 ng/ml for 17 of the patients. Treatment consisted of 50 Gy of external beam irradiation to the prostate and pelvic lymph nodes followed by a transperineal needle implant of the prostate gland. Thirty-two patients had no evidence of pelvic nodal involvement during exploration at laparotomy performed after external irradiation, and 25 of these had lymph node samplings that were histologically negative for metastasis. Perineal template oriented needles were placed by inspection and palpation at laparotomy; 2 were performed closed under ultrasound guidance. Needles were afterloaded with {sup 192}Ir to provide a dose of 30 Gy to the periphery of the prostate gland. Interstitial radiofrequency-induced hyperthermia treatments were given in conjunction with the implant, one just

  20. Pressure transducers

    International Nuclear Information System (INIS)

    Gomes, A.V.

    1975-01-01

    Strain gauges pressure transducers types are presented. Models, characteristics and calibration procedures were also analysed. Initially, a theoretical study was accomplished to evaluate metallic alloys behavior on sensing elements manufacturing, and diaphragm was used as deflecting elements. Electrical models for potenciometric transducers were proposed at the beginning and subsequently comproved according our experiments. Concerning bridge transducers, existing models confirmed the conditions of linearity and sensitivity related to the electrical signal. All the work done was of help on the calibration field and pressure measurements employing unbounded strain gauge pressure transducers

  1. Impact of pelvic nodal irradiation with intensity-modulated radiotherapy on treatment of prostate cancer

    International Nuclear Information System (INIS)

    Price, Robert A.; Hannoun-Levi, Jean-Michel; Horwitz, Eric; Buyyounouski, Mark; Ruth, Karen J.; Ma, C.-M.; Pollack, Alan

    2006-01-01

    Purpose: The aim of this study was to evaluate the feasibility of treating the pelvic lymphatic regions during prostate intensity-modulated radiotherapy (IMRT) with respect to our routine acceptance criteria. Methods and Materials: A series of 10 previously treated prostate patients were randomly selected and the pelvic lymphatic regions delineated on the fused magnetic resonance/computed tomography data sets. A targeting progression was formed from the prostate and proximal seminal vesicles only to the inclusion of all pelvic lymphatic regions and presacral region resulting in 5 planning scenarios of increasing geometric difficulty. IMRT plans were generated for each stage for two accelerator manufacturers. Dose volume histogram data were analyzed with respect to dose to the planning target volumes, rectum, bladder, bowel, and normal tissue. Analysis was performed for the number of segments required, monitor units, 'hot spots,' and treatment time. Results: Both rectal endpoints were met for all targets. Bladder endpoints were not met and the bowel endpoint was met in 40% of cases with the inclusion of the extended and presacral lymphatics. A significant difference was found in the number of segments and monitor units with targeting progression and between accelerators, with the smaller beamlets yielding poorer results. Treatment times between the 2 linacs did not exhibit a clinically significant difference when compared. Conclusions: Many issues should be considered with pelvic lymphatic irradiation during IMRT delivery for prostate cancer including dose per fraction, normal structure dose/volume limits, planning target volumes generation, localization, treatment time, and increased radiation leakage. We would suggest that, at a minimum, the endpoints used in this work be evaluated before beginning IMRT pelvic nodal irradiation

  2. High dose rate interstitial brachytherapy with external beam irradiation for localized prostate cancer. Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Hiratsuka, Junichi; Jo, Yoshimasa; Yoden, Eisaku; Tanaka, Hiroyoshi; Imajo, Yoshinari [Kawasaki Medical School, Kurashiki, Okayama (Japan); Nagase, Naomi; Narihiro, Naomasa; Kubota, Juichi

    2000-12-01

    This study was undertaken to assess the biochemical and pathological results of combined external beam radiotherapy and high dose rate Ir-192 brachytherapy (HDR-Ir192) for clinically localized prostate cancer. Between October 1997 and August 1999, 39 evaluable patients with adenocarcinoma of prostate diagnosed by biopsy were treated with interstitial and external beam irradiation. Patients ranged in age from 58-82 years, with a mean of 69.7 years. T1c, T2 and T3 tumors, according to the UICC classification system (1997), were found in 7, 21 and 11 cases respectively. The mean initial pre-treatment PSA was 35.9 ng/ml (median 13.2), with 77% of the patients having had a pre-treatment PSA greater than 10 ng/ml. Of all patients, 17 had received pre-treatment hormonal therapy. Hormonal pretreatment was stopped at the beginning of radiotherapy in all cases. External beam four-field box irradiation was given to the small pelvis to a dose of 45 Gy/25 fractions. Three HDR-Ir192 treatments were given over a 30-h period, with 5.5 Gy per fraction at the circumference of the prostate gland over the course of this study. Biochemical failure was defined as a PSA level >1.5 ng/ml and rising on three consecutive values. If serial post-treatment PSA levels showed a continuous downward trend, failure was not scored. The patient with clinical evidence of progression was classified as a clinical failure. The median follow-up at the time of evaluation was 19.6 months. A post-treatment PSA level {<=}1.0 ng/ml was seen in 26 (67%) patients, and values from >1.0 to {<=}2.0 ng/ml were seen in 10 (26%) patients. Biochemical failure was not seen in 38 patients except for one patient who developed a distant bone metastasis with negative prostatic biopsy 15 months after treatment. Biochemical control rate was 100% (38/38) except for the patient with bone metastasis classified as clinical failure. Negative biopsies 18 months after treatment were found in 93% (14/15) of patients. Only one patient

  3. Sexual dysfunctions after prostate cancer radiation therapy; Dysfonctions sexuelles apres irradiation pour cancer de la prostate

    Energy Technology Data Exchange (ETDEWEB)

    Droupy, S. [Service d' urologie-andrologie, CHU Caremeau, 30 - Nimes (France)

    2010-10-15

    Sexual dysfunctions are a quality of life main concern following prostate cancer treatment. After both radiotherapy and brachytherapy, sexual function declines progressively, the onset of occurrence of erectile dysfunction being 12-18 months after both treatments. The pathophysiological pathways by which radiotherapy and brachytherapy cause erectile dysfunction are multi-factorial, as patient co-morbidities, arterial damage, exposure of neurovascular bundle to high levels of radiation, and radiation dose received by the corpora cavernosa at the crurae of the penis may be important in the aetiology of erectile dysfunction. Diagnosis and treatment of postradiation sexual dysfunctions must integrate pre-therapeutic evaluation and information to provide to the patient and his partner a multidisciplinary sexual medicine management. (authors)

  4. Is there an increased risk of second primaries following prostate irradiation?

    International Nuclear Information System (INIS)

    Movsas, Benjamin; Hanlon, Alexandra L.; Pinover, Wayne; Hanks, Gerald E.

    1998-01-01

    Purpose: To assess the risk of developing a second primary cancer following prostate irradiation compared to the underlying risk in patients with prostate cancer. Methods and Materials: The baseline rate of secondary cancers following prostate cancer was obtained from a study of 18,135 patients from the Connecticut Tumor Registry, of whom only 12.5% received radiotherapy. These patients, with a mean age of 72 and a mean follow-up of 3.9 years, were compared to a cohort of 543 patients (median age 70) with similar follow-up (median 3.9 years), all of whom were treated with definitive radiotherapy at Fox Chase Cancer Center. The possible association between various covariates (age, dose, palpation stage, field size, Gleason score, pretreatment PSA) and the development of a secondary cancer was assessed. Results: 1,053 of 18,135 patients (5.8%) in the Connecticut Tumor Registry developed a second primary cancer compared with 31 of 543 (5.7%) patients treated with prostate radiation (p = 0.99). Although this risk increases gradually over time, it is not significantly different, at any time period, between the two groups of patients. Of the 31 secondary primaries in the irradiated group, 82% had a history of tobacco and/or alcohol use. Only melanomas were significantly increased compared to the expected rate in an age-matched population (p <0.001). Five of the 31 secondary cancers occurred within the radiation field (four bladder, one colon), four within 3 years and only one occurred 9 years after radiotherapy. No association was found between age (<70 vs. ≥70 and as a continuous variable), dose (<74 vs. ≥74 Gy), palpation stage (< T2C vs. ≥T2C), field size (prostate vs. pelvic), radiation technique (conventional vs. conformal), Gleason score (2-6 vs. 7-10), or pretreatment PSA (<15 vs. ≥15 and as a continuous variable) and the risk of developing a second primary. Although a lower radiation dose (as a continuous variable) correlated with an increased risk of

  5. Study on apoptosis of prostate cancer cell induced by 125I seed irradiation

    International Nuclear Information System (INIS)

    Liao Anyan; Wang Junjie; Wang Jidong; Zhuang Hongqing; Zhao Yong

    2007-01-01

    Objective: To explore the mechanism of apoptosis induced by 125 I seed irradiation on PC3 cells. Methods: Human prostate cancer cell line PC3 was treated by irradiation of 125 I (2.77 cGy/h) with various dose. Agarose gel electrophoresis of DNA and flows cytometry were used to detect the apoptosis of PC3 cells and indirect immunofluorescence assay was used to detect the expression of Bcl-2. The activity of Caspase-3 was measured by Caspase Colorimetric Assay Kits. Results: Apoptosis of PC3 cells could be efficiently induced by 125 I seed irradiation. The apoptotic peaks were found by flow cytometry and DNA ladder appeared on 1.8% agarose gel. The activity of Caspase-3 on PC3 cells treated by 125 I seed irradiation was not changed significantly. Bcl-2 gene expression was down-regulated with the sample concentration increased. Conclusion: 125 I irradiation can induce the apoptosis of PC3 cells and the mechanism of apoptosis is related with down regulation of Bcl-2 gene expression and is not related with Caspase-3 activity. (authors)

  6. Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers.

    Science.gov (United States)

    Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György

    2009-08-01

    Ultrasound imaging is becoming increasingly important in prostate brachytherapy. In high-dose-rate (HDR) real-time planning procedures the definition of the implant needles is often performed by transrectal ultrasound. This article describes absolute measurements of the visibility and accuracy of manual detection of implant needle tips and compares measurement results of different biplane ultrasound systems in transversal and longitudinal (i.e., sagittal) ultrasound modes. To obtain a fixed coordinate system and stable conditions the measurements were carried out in a water tank using a dedicated marker system. Needles were manually placed in the phantom until the observer decided by the real-time ultrasound image that the zero position was reached. A comparison of three different ultrasound systems yielded an offset between 0.8 and 3.1 mm for manual detection of the needle tip in ultrasound images by one observer. The direction of the offset was discovered to be in the proximal direction, i.e., the actual needle position was located more distally compared to the ultrasound-based definition. In the second part of the study, the ultrasound anisotropy of trocar implant needles is reported. It was shown that the integrated optical density in a region of interest around the needle tip changes with needle rotation. Three peaks were observed with a phase angle of 120 degrees. Peaks appear not only in transversal but also in longitudinal ultrasound images, with a phase shift of 60 degrees. The third section of this study shows results of observer dependent influences on needle tip detection in sagittal ultrasound images considering needle rotation. These experiments were carried out using the marker system in a water tank. The needle tip was placed exactly at the position z=0 mm. It was found that different users tend to differently interpret the same ultrasound images. The needle tip was manually detected five times in the ultrasound images by three experienced observers

  7. Clinical feasibility study for the use of implanted gold seeds in the prostate as reliable positioning markers during megavoltage irradiation

    International Nuclear Information System (INIS)

    Dehnad, Homan; Nederveen, Aart J.; Heide, Uulke A. van der; Moorselaar, R. Jeroen A. van; Hofman, Pieter; Lagendijk, Jan J.W.

    2003-01-01

    Background and purpose: The aim of this study was to assess the feasibility of using gold seed implants in the prostate for position verification, using an a-Si flat panel imager as a detector during megavoltage irradiation of prostate carcinoma. This is a study to guarantee positioning accuracy in intensity-modulated radiotherapy. Methods and materials: Ten patients with localized prostate carcinoma (T2-3) received between one and three fiducial gold markers in the prostate. All patients were treated with 3-D conformal radiotherapy with an anterior-posterior (AP) and two lateral wedge fields. The acute gastrointestinal (GI) and genitourinary (GU) toxicities were scored using common toxicity criteria scales (CTC). Using three consecutive CT scans and portal images obtained during the treatment we have studied the occurrence of any change in prostate shape (deformation), seed migration and the magnitude of translations and rotations of the prostate. Results: We observed no acute major complications for prostate irradiation regarding the seed implantation. The maximum acute GU toxicity grade 2 (dysuria and frequency) was observed in seven patients during the treatment. The maximum grade 2 (diarrhoea) was scored in two patients regarding the acute GI toxicities. No significant prostate deformation could be detected in the consecutive CT scans. It appeared that the distances between the markers only slightly changed during treatment (S.D. 0.5 mm). Random prostate translations were (1 S.D.) 2.1, 3.2 and 2.2 mm in the lateral (LR), AP and cranial-caudal (CC) directions, respectively, whereas systematic translations were 3.3, 4.8 and 3.5 mm in the LR, AP and CC directions, respectively. Random prostate rotations were (1 S.D.) 3.6, 1.7 and 1.9 deg. around the LR, AP and CC axis, respectively, whereas systematic rotations were 4.7, 2.0 and 2.7 deg. around the LR, AP and CC axis, respectively. Conclusions: We found that the fiducial gold seeds are a safe and appropriate

  8. Initial results of irradiation for prostatic cancer following three-dimensional treatment planning. Irradiation technique and toxicity

    International Nuclear Information System (INIS)

    Wiegel, T.; Schmidt, R.; Baumann, M.; Schwarz, R.; Steiner, P.; Arps, H.; Goeckel-Beining, B.

    1994-01-01

    During the period from June 91 until May 93 thirty-three patients suffering from histologically confirmed carcinoms of the prostate were assigned to four treatment groups and subjected to irradiation of the prostate and, if required, efferent lymphatic system of the minor pelvis that was performed according to a three-dimensional prospective treatment plan. The doses used for localized radiotherapy of the tumour tissue were in the range between 62 and 70 Gy, the efferent lymph system of the minor pelvis was irradiated with doses of up to 50 Gy. The local or boost treatments were carried out using four (box technique) or five irregular fields, while radiotherapy of the minor pelvis was solely based on the box technique using four fields of irregular shape. The immediate and long-term toxicity was evaluated in a prospective approach according to the RTOG score for the rectum, urinary bladder and skin. Twenty-five of the thirty-three patients (76%) developed immediate toxic symptoms. Immediate reactions classifiable with degree II of the rating scale were, however, only observed in four patients (15%) for the rectum (2), bladder (1) and skin (1). Immediate toxic reactions compatible with RTOG grades III or IV were not recorded. In all patients, the untoward effects were completely reversed within a maximum period of 6 weeks following termination of treatment. Two patients from the study cohort (6%), which has so far been followed up for an average period of 16 months, showed long-term grade I effects in the rectum and a further long-term effect observed in the urinary bladder of another patient was classified with degree II. Two patients died intercurrently and two patients developed metastases remote from the primary tumour. Local tumour control can currently be reported for 96%. (orig.) [de

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... an example of a transrectal transducer (probe). A prostate-specific antigen (PSA) test, which measures the amount of PSA in the blood, may be administered to determine if a patient is at high risk for ... of the prostate gland. When the examination is complete, you may ...

  10. Molecular Ultrasound Imaging of Early Vascular Response in Prostate Tumors Irradiated with Carbon Ions

    Directory of Open Access Journals (Sweden)

    Moritz Palmowski

    2009-09-01

    Full Text Available Individualized treatments with combination of radiotherapy and targeted drugs require knowledge about the behavior of molecular targets after irradiation. Angiogenic marker expression has been studied after conventional radiotherapy, but little is known about marker response to charged particles. For the very first time, we used molecular ultrasound imaging to intraindividually track changes in angiogenic marker expression after carbon ion irradiation in experimental tumors. Expression of intercellular adhesion molecule-1 (ICAM-1 and of αvβ3-integrin in subcutaneous AT-1 prostate cancers in rats treated with carbon ions (16 Gy was studied using molecular ultrasound and immunohistochemistry. For this purpose, cyanoacrylate microbubbles were synthesized and linked to specific ligands. The accumulation of targeted microbubbles in tumors was quantified before and 36 hours after irradiation. In addition, tumor vascularization was analyzed using volumetric Doppler ultrasound. In tumors, the accumulation of targeted microbubbles was significantly higher than in nonspecific ones and could be inhibited competitively. Before irradiation, no difference in binding of αvβ3-integrin-specific or ICAM-1-specific microbubbles was observed in treated and untreated animals. After irradiation, however, treated animals showed a significantly higher binding of αvβ3-integrin-specific microbubbles and an enhanced binding of ICAM-1-specific microbubbles than untreated controls. In both groups, a decrease in vascularization occurred during tumor growth, but no significant difference was observed between irradiated and nonirradiated tumors. In conclusion, carbon ion irradiation upregulates ICAM-1 and αvβ3-integrin expression in tumor neovasculature. Molecular ultrasound can indicate the regulation of these markers and thus may help to identify the optimal drugs and time points in individualized therapy regimens.

  11. Acoustic transducer

    Science.gov (United States)

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  12. Coaxial Transducer

    National Research Council Canada - National Science Library

    Ruffa, Anthony A

    2008-01-01

    The invention as disclosed is of a coaxial transducer that uses lead zirconate titanate ceramic or other suitable material as an isolator between the conductors in a coaxial cable to transmit acoustic...

  13. Prognosis in patients with local recurrence after definitive irradiation for prostatic carcinoma

    International Nuclear Information System (INIS)

    Kuban, D.A.; el-Mahdi, A.M.; Schellhammer, P.F.

    1989-01-01

    Of 414 patients with Stage A2-C disease, all with a minimum follow-up period of 3 years, who have been definitively irradiated by external beam therapy or iodine-125 (I-125) implantation for biopsy-proven prostatic adenocarcinoma, 83 patients (20%) have experienced local recurrences. The incidence of distant metastasis was significantly higher in patients with local tumor recurrence (56 of 83; 68%), as compared with those with local control (64 of 331; 19%; P less than 0.001). This difference remained significant within each tumor grade and stage. Subsequently, survival in patients with local recurrence was significantly shorter than in those with local tumor control (66% vs. 89% at 5 years; P = 0.001). Of the 83 patients with local tumor recurrence, 56 had local recurrence and distant metastasis, and 27 had local failure alone, with a median follow-up of 76 months for the latter group. Fifteen of 83 patients with local recurrence (18%) developed major complications secondary to local disease. Three of the 83 (4%) patients were known to die of prostatic recurrence alone and another 11 of 83 (13%) as a result of some combination of local and distant disease. Therefore, in reference to the entire group of definitively irradiated patients, only 0.72% expired solely of complications associated with local tumor recurrence and an additional 2.7% expired of a combination of both local and distant disease

  14. Prostate cancer

    International Nuclear Information System (INIS)

    Murphy, G.P.; Kuss, R.; Khoury, S.; Chatelain, C.; Denis, L.

    1987-01-01

    This book contains over 70 selections. Some of the titles are: Place of the Computed Tomography in the Staging of Prostatic Cancer; Magnetic Resonance Imaging (MRI) in Staging of the Prostatic Cancer; Magnetic Resonance Imaging of the Prostate; Long-Term Results in Radiotherapy of Prostatic Cancer; Interstitial Irradiation Using I-125 Seeds; and Treatment of Cancer of the Prostate by Use of Physiotherapy: Long-Term Results

  15. Prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, G.P.; Kuss, R., Khoury, S.; Chatelain, C.; Denis, L.

    1987-01-01

    This book contains over 70 selections. Some of the titles are: Place of the Computed Tomography in the Staging of Prostatic Cancer; Magnetic Resonance Imaging (MRI) in Staging of the Prostatic Cancer; Magnetic Resonance Imaging of the Prostate; Long-Term Results in Radiotherapy of Prostatic Cancer; Interstitial Irradiation Using I-125 Seeds; and Treatment of Cancer of the Prostate by Use of Physiotherapy: Long-Term Results.

  16. High-precision prostate cancer irradiation by clinical application of an offline patient setup verification procedure, using portal imaging

    NARCIS (Netherlands)

    Bel, A.; Vos, P. H.; Rodrigus, P. T.; Creutzberg, C. L.; Visser, A. G.; Stroom, J. C.; Lebesque, J. V.

    1996-01-01

    PURPOSE: To investigate in three institutions, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Huis [AvL]), Dr. Daniel den Hoed Cancer Center (DDHC), and Dr, Bernard Verbeeten Institute (BVI), how much the patient setup accuracy for irradiation of prostate cancer can be improved by an

  17. High-precision prostate cancer irradiation by clinical application of an offline patient setup verification procedure, using portal imaging

    NARCIS (Netherlands)

    A. Bel (Arjan); P.H. Vos (Pieter); P. Rodrigus (Patrick); C.L. Creutzberg (Carien); A.G. Visser (Andries); J.Ch. Stroom (Joep); J.V. Lebesque (Joos)

    1996-01-01

    textabstractPurpose: To investigate in three institutions, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Huis [AvL]), Dr. Daniel den Hoed Cancer Center (DDHC), and Dr. Bernard Verbeeten Institute (BVI), how much the patient setup accuracy for irradiation of prostate cancer can be improved

  18. Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy include senescence, necrosis, and autophagy, but not apoptosis

    International Nuclear Information System (INIS)

    Frame, Fiona M.; Savoie, Huguette; Bryden, Francesca; Giuntini, Francesca; Mann, Vincent M.; Simms, Matthew S.; Boyle, Ross W.; Maitland, Norman J.

    2015-01-01

    In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer

  19. Intracavitary irradiation of prostatic carcinoma by a high dose-rate afterloading technique

    Energy Technology Data Exchange (ETDEWEB)

    Odelberg-Johnson, O.; Underskog, I.; Johansson, J.E.; Bernshaw, D.; Sorbe, B.; Persson, J.E. (Oerebro Medical Center Hospital (Sweden). Dept. of Oncology Oerebro Medical Center Hospital (Sweden). Dept. of Urology Oerebro Medical Center Hospital (Sweden). Dept. of Gynecologic Oncology Oerebro Medical Center Hospital (Sweden). Dept. of Radiation Physics)

    1991-01-01

    A high dose-rate ({sup 60}Co) afterloading technique was evaluated in a series of 73 patients with prostatic carcinoma stages I-IV. The intraurethral irradiation was combined with external pelvic radiotherapy. A minimum total dose of 78 Gy was delivered to the target volume. In a subgroup of patients extramustine (Estracyt) was given as adjuvant chemohormonal therapy during irradiation. The median follow-up for the whole group was 63 months. The crude 5-year survival rate was 60% and the corrected survival rate 90%. Survival was related to the tumor grade. Local pelvic recurrences were recorded in 17.8%. 'Viable cells' in posttherapy aspiration biopsy were not associated with tumor recurrences or survival. Four patients (5%) had grade 3 late radiation reactions with urethral structure or bladder fibrosis. Urinary tract infections and prior transurethral resections were not associated with a higher frequency of reactions. Concurrent estramustine therapy seemed to increase the frequency of both acute and chronic radiation reactions. Local control, recurrence, and survival were not affected by chemohormonal therapy. The use of tomography, magnetic resonance, and ultrasound as aids to computerized dosimetry may improve local dose distribution and reduce the irradiated volume. (orig.).

  20. Ion Prostate Irradiation (IPI) – a pilot study to establish the safety and feasibility of primary hypofractionated irradiation of the prostate with protons and carbon ions in a raster scan technique

    International Nuclear Information System (INIS)

    Habl, Gregor; Herfarth, Klaus; Hatiboglu, Gencay; Edler, Lutz; Uhl, Matthias; Krause, Sonja; Roethke, Matthias; Schlemmer, Heinz P; Hadaschik, Boris; Debus, Juergen

    2014-01-01

    Due to physical characteristics, ions like protons or carbon ions can administer the dose to the target volume more efficiently than photons since the dose can be lowered at the surrounding normal tissue. Radiation biological considerations are based on the assumption that the α/β value for prostate cancer cells is 1.5 Gy, so that a biologically more effective dose could be administered due to hypofractionation without increasing risks of late effects of bladder (α/β = 4.0) and rectum (α/β = 3.9). The IPI study is a prospective randomized phase II study exploring the safety and feasibility of primary hypofractionated irradiation of the prostate with protons and carbon ions in a raster scan technique. The study is designed to enroll 92 patients with localized prostate cancer. Primary aim is the assessment of the safety and feasibility of the study treatment on the basis of incidence grade III and IV NCI-CTC-AE (v. 4.02) toxicity and/or the dropout of the patient from the planned therapy due to any reason. Secondary endpoints are PSA-progression free survival (PSA-PFS), overall survival (OS) and quality-of-life (QoL). This pilot study aims at the evaluation of the safety and feasibility of hypofractionated irradiation of the prostate with protons and carbon ions in prostate cancer patients in an active beam technique. Additionally, the safety results will be compared with Japanese results recently published for carbon ion irradiation. Due to the missing data of protons in this hypofractionated scheme, an in depth evaluation of the toxicity will be created to gain basic data for a following comparison study with carbon ion irradiation. Clinical Trial Identifier: http://clinicaltrials.gov/show/NCT01641185 (clinicaltrials.gov)

  1. Preoperative irradiation, lymphadenectomy, and 125iodine implantation for patients with localized carcinoma of the prostate

    International Nuclear Information System (INIS)

    DeLaney, T.F.; Shipley, W.U.; O'Leary, M.P.; Biggs, P.J.; Prout, G.R. Jr.

    1986-01-01

    Fifty-four patients with clinically and surgically localized prostatic carcinoma were treated with low-dose preoperative irradiation (1050 cGy), pelvic lymphadenectomy, and interstitial 125 Iodine implantation. The follow-up range is 2 to 9 years with a median follow-up of 5 years. Overall local tumor control is 92%. Actuarial 5-year survival is 86% and the actuarial disease-free survival at 5 years is 73%. Patients with poorly differentiated tumors have a significantly worse actuarial survival (62%) at 5 years than patients with well (95%) or moderately well differentiated tumors (93%), p = 0.04. Disease-free survival at 5 years was influenced by grade: well (100%), moderate (60%), and poor (48%), p = 0.03. Multivariate regression analysis indicates that only the degree of differentiation (p = 0.05) significantly impacts on survival. Both degree of differentiation (p = 0.04) and nodal status (p = 0.03) significantly influence disease-free survival. Potency has been maintained in 71% of patients potent at the time of implantation. Late reactions have been acceptable to date: bladder outlet obstruction (13%), mild proctitis (13%), cystourethritis (6%), incontinence (2%), and prostatic calculi (2%)

  2. 18F-fluorocholine PET-guided target volume delineation techniques for partial prostate re-irradiation in local recurrent prostate cancer

    International Nuclear Information System (INIS)

    Wang Hui; Vees, Hansjoerg; Miralbell, Raymond; Wissmeyer, Michael; Steiner, Charles; Ratib, Osman; Senthamizhchelvan, Srinivasan; Zaidi, Habib

    2009-01-01

    Background and purpose: We evaluate the contribution of 18 F-choline PET/CT in the delineation of gross tumour volume (GTV) in local recurrent prostate cancer after initial irradiation using various PET image segmentation techniques. Materials and methods: Seventeen patients with local-only recurrent prostate cancer (median = 5.7 years) after initial irradiation were included in the study. Rebiopsies were performed in 10 patients that confirmed the local recurrence. Following injection of 300 MBq of 18 F-fluorocholine, dynamic PET frames (3 min each) were reconstructed from the list-mode acquisition. Five PET image segmentation techniques were used to delineate the 18 F-choline-based GTVs. These included manual delineation of contours (GTV man ) by two teams consisting of a radiation oncologist and a nuclear medicine physician each, a fixed threshold of 40% and 50% of the maximum signal intensity (GTV 40% and GTV 50% ), signal-to-background ratio-based adaptive thresholding (GTV SBR ), and a region growing (GTV RG ) algorithm. Geographic mismatches between the GTVs were also assessed using overlap analysis. Results: Inter-observer variability for manual delineation of GTVs was high but not statistically significant (p = 0.459). In addition, the volumes and shapes of GTVs delineated using semi-automated techniques were significantly higher than those of GTVs defined manually. Conclusions: Semi-automated segmentation techniques for 18 F-choline PET-guided GTV delineation resulted in substantially higher GTVs compared to manual delineation and might replace the latter for determination of recurrent prostate cancer for partial prostate re-irradiation. The selection of the most appropriate segmentation algorithm still needs to be determined.

  3. 18F-fluorocholine PET-guided target volume delineation techniques for partial prostate re-irradiation in local recurrent prostate cancer.

    Science.gov (United States)

    Wang, Hui; Vees, Hansjörg; Miralbell, Raymond; Wissmeyer, Michael; Steiner, Charles; Ratib, Osman; Senthamizhchelvan, Srinivasan; Zaidi, Habib

    2009-11-01

    We evaluate the contribution of (18)F-choline PET/CT in the delineation of gross tumour volume (GTV) in local recurrent prostate cancer after initial irradiation using various PET image segmentation techniques. Seventeen patients with local-only recurrent prostate cancer (median=5.7 years) after initial irradiation were included in the study. Rebiopsies were performed in 10 patients that confirmed the local recurrence. Following injection of 300 MBq of (18)F-fluorocholine, dynamic PET frames (3 min each) were reconstructed from the list-mode acquisition. Five PET image segmentation techniques were used to delineate the (18)F-choline-based GTVs. These included manual delineation of contours (GTV(man)) by two teams consisting of a radiation oncologist and a nuclear medicine physician each, a fixed threshold of 40% and 50% of the maximum signal intensity (GTV(40%) and GTV(50%)), signal-to-background ratio-based adaptive thresholding (GTV(SBR)), and a region growing (GTV(RG)) algorithm. Geographic mismatches between the GTVs were also assessed using overlap analysis. Inter-observer variability for manual delineation of GTVs was high but not statistically significant (p=0.459). In addition, the volumes and shapes of GTVs delineated using semi-automated techniques were significantly higher than those of GTVs defined manually. Semi-automated segmentation techniques for (18)F-choline PET-guided GTV delineation resulted in substantially higher GTVs compared to manual delineation and might replace the latter for determination of recurrent prostate cancer for partial prostate re-irradiation. The selection of the most appropriate segmentation algorithm still needs to be determined.

  4. Carbon ion irradiation of the human prostate cancer cell line PC3: A whole genome microarray study

    Science.gov (United States)

    SUETENS, ANNELIES; MOREELS, MARJAN; QUINTENS, ROEL; CHIRIOTTI, SABINA; TABURY, KEVIN; MICHAUX, ARLETTE; GRÉGOIRE, VINCENT; BAATOUT, SARAH

    2014-01-01

    Hadrontherapy is a form of external radiation therapy, which uses beams of charged particles such as carbon ions. Compared to conventional radiotherapy with photons, the main advantage of carbon ion therapy is the precise dose localization along with an increased biological effectiveness. The first results obtained from prostate cancer patients treated with carbon ion therapy showed good local tumor control and survival rates. In view of this advanced treatment modality we investigated the effects of irradiation with different beam qualities on gene expression changes in the PC3 prostate adenocarcinoma cell line. For this purpose, PC3 cells were irradiated with various doses (0.0, 0.5 and 2.0 Gy) of carbon ions (LET=33.7 keV/μm) at the beam of the Grand Accélérateur National d’Ions Lourds (Caen, France). Comparative experiments with X-rays were performed at the Belgian Nuclear Research Centre. Genome-wide gene expression was analyzed using microarrays. Our results show a downregulation in many genes involved in cell cycle and cell organization processes after 2.0 Gy irradiation. This effect was more pronounced after carbon ion irradiation compared with X-rays. Furthermore, we found a significant downregulation of many genes related to cell motility. Several of these changes were confirmed using qPCR. In addition, recurrence-free survival analysis of prostate cancer patients based on one of these motility genes (FN1) revealed that patients with low expression levels had a prolonged recurrence-free survival time, indicating that this gene may be a potential prognostic biomarker for prostate cancer. Understanding how different radiation qualities affect the cellular behavior of prostate cancer cells is important to improve the clinical outcome of cancer radiation therapy. PMID:24504141

  5. Cell Survival and DNA Damage in Normal Prostate Cells Irradiated Out-of-Field.

    LENUS (Irish Health Repository)

    Shields, L

    2014-10-31

    Interest in out-of-field radiation dose has been increasing with the introduction of new techniques, such as volumetric modulated arc therapy (VMAT). These new techniques offer superior conformity of high-dose regions to the target compared to conventional techniques, however more normal tissue is exposed to low-dose radiation with VMAT. There is a potential increase in radiobiological effectiveness associated with lower energy photons delivered during VMAT as normal cells are exposed to a temporal change in incident photon energy spectrum. During VMAT deliveries, normal cells can be exposed to the primary radiation beam, as well as to transmission and scatter radiation. The impact of low-dose radiation, radiation-induced bystander effect and change in energy spectrum on normal cells are not well understood. The current study examined cell survival and DNA damage in normal prostate cells after exposure to out-of-field radiation both with and without the transfer of bystander factors. The effect of a change in energy spectrum out-of-field compared to in-field was also investigated. Prostate cancer (LNCaP) and normal prostate (PNT1A) cells were placed in-field and out-of-field, respectively, with the PNT1A cells being located 1 cm from the field edge when in-field cells were being irradiated with 2 Gy. Clonogenic and γ-H2AX assays were performed postirradiation to examine cell survival and DNA damage. The assays were repeated when bystander factors from the LNCaP cells were transferred to the PNT1A cells and also when the PNT1A cells were irradiated in-field to a different energy spectrum. An average out-of-field dose of 10.8 ± 4.2 cGy produced a significant reduction in colony volume and increase in the number of γ-H2AX foci\\/cell in the PNT1A cells compared to the sham-irradiated control cells. An adaptive response was observed in the PNT1A cells having first received a low out-of-field dose and then the bystander factors. The PNT1A cells showed a significant

  6. The combined treatment of prostate cancer (stage C) with definitive megavoltage irradiation and fast neutrons (DT, 14 MeV)

    International Nuclear Information System (INIS)

    Franke, H.D.; Hess, A.; Langendorff, G.; Borchers, H.D.

    1980-01-01

    We treated between 1977 and 1979 patients with low differentiated prostate cancer stage C with megavoltage irradiation (42 MeV-X-rays) in the whole pelvis, including the prostate, up to 30-45 Gy/3-4,5 weeks; thereafter we irradiated a boost on the primary with 6-8 isocentric fields of fast neutrons up to 3,9-8,4 Gy/1-2 weeks. The 13 treated patients had all clinically complete regression of the tumor, they are without local recidive since 9-43 months. Biopsies of 3 patients are morphologic free of tumor cells already 8-12 months after irradiation. Distant metastases occurred in 3 patients: 2 are living since 16 and 43 months, 1 died after 24 months. All patients are free of serious chronic side effects at bladder and rectum, only 1 lives with a slight proctitis after therapy with only 2 opposing fields. The 14th patient is treated on behalf of a local recidive after prostatectomy (anaplastic prostate cancer) and a big pararectal metastasis; we irradiated the whole pelvis with fast neutrons up to a dose of 15,3 Gy/4 weeks (total dose, n + γ): The patient is free of pains since 9 months and without tumor in computer tomography, and free of serious chronic complications. (orig./MG) [de

  7. Synchronous prostate and rectal adenocarcinomas irradiation utilising volumetric modulated arc therapy.

    Science.gov (United States)

    Ng, Sweet Ping; Tran, Thu; Moloney, Philip; Sale, Charlotte; Mathlum, Maitham; Ong, Grace; Lynch, Rod

    2015-12-01

    Cases of synchronous prostate and colorectal adenocarcinomas have been sporadically reported. There are case reports on patients with synchronous prostate and rectal cancers treated with external beam radiotherapy alone or combined with high-dose rate brachytherapy boost to the prostate. Here, we illustrate a patient with synchronous prostate and rectal cancers treated using the volumetric arc therapy (VMAT) technique. The patient was treated with radical radiotherapy to 50.4 Gy in 28 fractions to the pelvis, incorporating the involved internal iliac node and the prostate. A boost of 24 Gy in 12 fractions was delivered to the prostate only, using VMAT. Treatment-related toxicities and follow-up prostate-specific antigen and carcinoembryonic antigen were collected for data analysis. At 12 months, the patient achieved complete response for both rectal and prostate cancers without significant treatment-related toxicities.

  8. Synchronous prostate and rectal adenocarcinomas irradiation utilising volumetric modulated arc therapy

    OpenAIRE

    Ng, Sweet Ping; Tran, Thu; Moloney, Philip; Sale, Charlotte; Mathlum, Maitham; Ong, Grace; Lynch, Rod

    2015-01-01

    Abstract Cases of synchronous prostate and colorectal adenocarcinomas have been sporadically reported. There are case reports on patients with synchronous prostate and rectal cancers treated with external beam radiotherapy alone or combined with high?dose rate brachytherapy boost to the prostate. Here, we illustrate a patient with synchronous prostate and rectal cancers treated using the volumetric arc therapy (VMAT) technique. The patient was treated with radical radiotherapy to 50.4 Gy in 2...

  9. EPID detection of radio-opaque markers for the evaluation of prostate position during megavoltage irradiation: a clinical study

    International Nuclear Information System (INIS)

    Vigneault, E.; Pouliot, J.; Laverdiere, J.; Roy, J.

    1995-01-01

    Purpose: To assess daily prostatic apex motion relative to pelvic bone structures during megavoltage irradiation. Materials and Methods: Radio-opaque markers were implanted under ultrasound guidance near the prostatic apex of ten patients with localized prostatic carcinoma. Patients were subsequently treated with four field box technique at a beam energy of 23 MV. During treatment, on-line images were obtained with an Electronic Portal Imaging Device (EPID) for each field and fraction. The marker was easily identified, even on unprocessed images and the distance between the marker and a bony landmark was measured. Timelapse movie for the complete treatment of each patient were also reviewed. After the completion of treatment, a transrectal ultrasound examination was performed to verify the position of the marker relative to the apex. Results: Over 1000 digital portal images were acquired. Antero-posterior and lateral views of each fraction were analysed. The quality of portal images obtained with megavoltage irradiation was good. Even without image histogram equalization it was possible to evaluate pelvic bone structures. Moreover, the radio-opaque marker was easily visible on every on-line portal image. Qualitatively, the review of timelapse movies showed important interfraction motions of the marker while bone structures remained stable. Quantitatively, the position of the marker were measured for each fraction. Marker displacements of up to 1,4 cm were measured between two consecutive days of treatment. Important marker motions were predominately in the antero-posterior and cephalo-caudal directions. Position of the markers relative to the prostatic apex were verified with ultrasound at the end of the treatments and were found to remain globaly at their original position. Intratreatment images were reviewed in two cases and no change in marker positions was observed. Our results, obtained during the treatment courses, indicate similar or larger prostate motions

  10. Therapeutic results and prognostic factors after irradiation of loco-regional prostate cancer

    International Nuclear Information System (INIS)

    Debrigode, C.; Dubois, J.; Hay, H.M.; Astre, C.; Savu, N.M.

    1994-01-01

    The present study concerns 140 patients with loco-regional prostatic cancer, treated with external beam irradiation at the CRLC Val-d'Aurelle in Montpellier, France, between 1982 and 1988, with a minimum of 54 months follow-up. The local control after radiotherapy is 78.6%, all stages and histological grades combined. The median overall survival is 114 months and the median disease-free survival 59 months. The most frequent modality of treatment failure is metastatic disease, isolated (32.8%) or combined to local relapse (10%). The rate of urinary intolerance symptoms during treatment was 87.1 and 80.6% for the digestive ones. The late urinary complications and sequellae rate was 21.4% for the cystitis-type and 12.9% for post-radiotherapy urethral structures; the latter has imposed in 2/3 of cases one or more trans-urethral resections that never showed pathological signs of recurrence. Digestive complications and sequellae occurred in 31.3% of the patients; in the latter group there were two internal digestive fistulae which needed surgical treatment and three postradiotherapeutic stenosis of the anal canal. The prognostic factors revealed by statistical analysis are clinical stage, pathological grade for overall and disease-free survival, age for overall survival and trans-urethral resection for disease-free survival, the latter being equally a risk factor for cystitis-type complications and urethral structures. (authors). 26 refs., 8 figs., 7 tabs

  11. Electronic portal imaging device detection of radioopaque markers for the evaluation of prostate position during megavoltage irradiation: a clinical study

    International Nuclear Information System (INIS)

    Vigneault, Eric; Pouliot, Jean; Laverdiere, Jacques; Roy, Jean; Dorion, Marc

    1997-01-01

    Purpose: This study was designed to assess daily prostatic apex motion relative to pelvic bone structures during megavoltage irradiation. Methods and Materials: Radioopaque markers were implanted under ultrasound guidance near the prostatic apex of 11 patients with localized prostatic carcinoma. Patients were subsequently treated with a four field-box technique at a beam energy of 23 MV. During treatment, on-line images were obtained with an electronic portal imaging device (EPID). The marker was easily identified, even on unprocessed images, and the distance between the marker and a bony landmark was measured. Timelapse movies were also reviewed. After the completion of treatment, a transcrectal ultrasound examination was performed in 8 of 11 patients, to verify the position of the marker. Results: We acquired over 900 digital portal images and analyzed posterioanterior and right lateral views. The quality of portal images obtained with megavoltage irradiation was good. It was possible to evaluate pelvic bone structures even without image histogram equalization. Moreover, the radioopaque marker was easily visible on every online portal image. The review of timelapse movies showed important interfraction motion of the marker while bone structures remained stable. We measured the position of the marker for each fraction. Marker displacements up to 1.6 cm were measured between 2 consecutive days of treatment. Important marker motions were predominantly in the posteroanterior and cephalocaudal directions. In eight patients, we verified the position of the marker relative to the prostatic apex with ultrasound at the end of the treatments. The marker remained in the trapezoid zone. Intratreatment images reviewed in two cases showed no change in marker position. Our results, obtained during the treatment courses, indicate similar or larger prostate motions than previously observed in studies that used intertreatment x-ray films and CT images. Marker implantation under

  12. Stress wave focusing transducers

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S.R., LLNL

    1998-05-15

    Conversion of laser radiation to mechanical energy is the fundamental process behind many medical laser procedures, particularly those involving tissue destruction and removal. Stress waves can be generated with laser radiation in several ways: creation of a plasma and subsequent launch of a shock wave, thermoelastic expansion of the target tissue, vapor bubble collapse, and ablation recoil. Thermoelastic generation of stress waves generally requires short laser pulse durations and high energy density. Thermoelastic stress waves can be formed when the laser pulse duration is shorter than the acoustic transit time of the material: {tau}{sub c} = d/c{sub s} where d = absorption depth or spot diameter, whichever is smaller, and c{sub s} = sound speed in the material. The stress wave due to thermoelastic expansion travels at the sound speed (approximately 1500 m/s in tissue) and leaves the site of irradiation well before subsequent thermal events can be initiated. These stress waves, often evolving into shock waves, can be used to disrupt tissue. Shock waves are used in ophthalmology to perform intraocular microsurgery and photodisruptive procedures as well as in lithotripsy to fragment stones. We have explored a variety of transducers that can efficiently convert optical to mechanical energy. One such class of transducers allows a shock wave to be focused within a material such that the stress magnitude can be greatly increased compared to conventional geometries. Some transducer tips could be made to operate regardless of the absorption properties of the ambient media. The size and nature of the devices enable easy delivery, potentially minimally-invasive procedures, and precise tissue- targeting while limiting thermal loading. The transducer tips may have applications in lithotripsy, ophthalmology, drug delivery, and cardiology.

  13. Hypofractionated Prostate Radiotherapy with or without Conventionally Fractionated Nodal Irradiation: Clinical Toxicity Observations and Retrospective Daily Dosimetry.

    Science.gov (United States)

    McDonald, Andrew M; Bishop, Justin M; Jacob, Rojymon; Dobelbower, Michael C; Kim, Robert Y; Yang, Eddy S; Smith, Heather; Wu, Xingen; Fiveash, John B

    2012-01-01

    Purpose. To evaluate toxicity associated with the addition of elective nodal irradiation (ENI) to a hypofractionated regimen for the treatment of prostate cancer. Methods and Materials. Fifty-seven patients received pelvic image-guided IMRT to 50.4 Gy in 28 fractions with a hypofractionated simultaneous boost to the prostate to 70 Gy. Thirty-one patients received prostate-only treatment to 70 Gy in 28 fractions. Results. Median followup was 41.1 months. Early grade ≥2 urinary toxicity rates were 49% (28 of 57) for patients receiving ENI and 58% (18 of 31) for those not (P = 0.61). Early grade ≥2 rectal toxicity rates were 40% (23 of 57) and 23% (7 of 31), respectively (P = 0.09). The addition of ENI resulted in a 21% actuarial rate of late grade ≥2 rectal toxicity at 4 years, compared to 0% for patients treated to the prostate only (P = 0.02). Retrospective daily dosimetry of patients experiencing late rectal toxicity revealed an average increase of 2.67% of the rectal volume receiving 70 Gy compared to the original plan. Conclusions. The addition of ENI resulted in an increased risk of late rectal toxicity. Grade ≥2 late rectal toxicity was associated with worse daily rectal dosimetry compared to the treatment plan.

  14. Irradiation of the prostate and pelvic lymph nodes with an adaptive algorithm

    International Nuclear Information System (INIS)

    Hwang, A. B.; Chen, J.; Nguyen, T. B.; Gottschalk, A. G.; Roach, M. R. III; Pouliot, J.

    2012-01-01

    Purpose: The simultaneous treatment of pelvic lymph nodes and the prostate in radiotherapy for prostate cancer is complicated by the independent motion of these two target volumes. In this work, the authors study a method to adapt intensity modulated radiation therapy (IMRT) treatment plans so as to compensate for this motion by adaptively morphing the multileaf collimator apertures and adjusting the segment weights. Methods: The study used CT images, tumor volumes, and normal tissue contours from patients treated in our institution. An IMRT treatment plan was then created using direct aperture optimization to deliver 45 Gy to the pelvic lymph nodes and 50 Gy to the prostate and seminal vesicles. The prostate target volume was then shifted in either the anterior-posterior direction or in the superior-inferior direction. The treatment plan was adapted by adjusting the aperture shapes with or without re-optimizing the segment weighting. The dose to the target volumes was then determined for the adapted plan. Results: Without compensation for prostate motion, 1 cm shifts of the prostate resulted in an average decrease of 14% in D-95%. If the isocenter is simply shifted to match the prostate motion, the prostate receives the correct dose but the pelvic lymph nodes are underdosed by 14% ± 6%. The use of adaptive morphing (with or without segment weight optimization) reduces the average change in D-95% to less than 5% for both the pelvic lymph nodes and the prostate. Conclusions: Adaptive morphing with and without segment weight optimization can be used to compensate for the independent motion of the prostate and lymph nodes when combined with daily imaging or other methods to track the prostate motion. This method allows the delivery of the correct dose to both the prostate and lymph nodes with only small changes to the dose delivered to the target volumes.

  15. The impact of race on biochemical outcome in patients receiving irradiation for prostate cancer

    International Nuclear Information System (INIS)

    Nautiyal, Jai; Vaida, Florin; Awan, Azhar; Weichselbaum, Ralph R.; Vijayakumar, Srinivasan

    1996-01-01

    Purpose/Objective: African-Americans tend to present with a higher stage and grade prostate cancer than whites and hence previous studies have attempted to delineate the importance of race in outcome with radiotherapy. However, these studies have had limitations including insufficient number of African-American patients, lack of a similar quality of care or uniform treatment policy. In addition, race as a prognostic variable has not been analyzed in regards to PSA based outcome criteria. The current study was performed in order to determine the impact of race on survival and biochemical control in patients with prostate cancer treated at a single center using a standardized radiation protocol. Materials and Methods: Between 1988 and 1995, 455 patients with clinically localized adenocarcinoma of the prostate received external beam irradiation for a median dose of 68 Gy using a four field technique. Of the 455 patients, 211 were African-American and 244 were white. Pretreatment PSA were: 0-4 ng/ml (51), 4-10 ng/ml (129), 10-20 ng/ml (117), > 20 ng/ml (136), unknown (22). Clinical stages were: T1 (108), T2 (238), T3 (99), not available (10). There was no significant difference in pretreatment characteristics (stage, grade and PSA) or radiation dose between the African-American and white group of patients. Median follow-up is 37.8 months. Biochemical failure was defined as two or more consecutive PSA values that are greater than the posttreatment nadir. Race, pretreatment PSA, grade, age, stage and dose were assessed with univariate and multivariate Cox regression analysis as prognostic factors for overall survival and biochemical disease free survival. Results: The 5 year actuarial overall survival (OS) was 79% and biochemical disease free survival (bNED) was 35% for the entire group of patients. There was no significant difference in 5 year OS (71% vs. 85%) (p=0.3) or bNED (26% vs. 40%) (p=0.26) for African-Americans in comparison to whites. Univariate analysis

  16. Adjuvant and salvage therapy following radical prostatectomy for prostate cancer: effect of combined transient androgen deprivation and irradiation

    International Nuclear Information System (INIS)

    Eulau, Stephen M.; Tate, David J.; Cox, Richard S.; Bagshaw, Malcolm A.; Hancock, Steven L.

    1996-01-01

    Purpose: Adjuvant and salvage irradiation have been shown to improve local control after radical prostatectomy for prostatic cancer in patients with high risk pathologic features, rising PSA, or evidence of local failure. Transient androgen deprivation combined with primary irradiation has resulted in improved local control and biochemical disease free survival in patients with locally advanced, unresected, prostate cancer. This retrospective study evaluates whether transient androgen blockade improves the outcome from post-prostatectomy irradiation given as either adjuvant or salvage therapy. Methods: From August, 1985 to December, 1995, 105 patients were treated with radiotherapy to the prostatic fossa following radical prostatectomy for adenocarcinoma of the prostate. No patient had clinically or radiographically evident distant disease. Median follow-up was 4.6 years from the date of surgery and 3.2 years from completion of radiotherapy. Findings at prostatectomy included capsular penetration in 38 patients, seminal vesicle involvement in 42 patients, lymph node involvement in 15 patients, and positive surgical margins in 70 patients. Treatment was administered as adjuvant therapy for high risk pathologic features in 39 patients, for persistent or rising PSA in 52 patients, or for clinically evident local recurrence in 14 patients. Of the 105 patients, 32 received combined androgen deprivation/radiotherapy and 73 received radiotherapy alone. Both groups received 60-70 Gy in 2 Gy daily fractions to the prostatic fossa. Selected patients with poor prognostic features received pelvic irradiation to a median dose of 50 Gy. Androgen deprivation typically consisted of Lupron and Flutamide for 4 to 6 months before, during, and in selected cases, after irradiation. No patients received maintenance androgen deprivation or underwent orchiectomy. Tumor stage, lymph node status, Gleason sum, and indications for treatment did not differ significantly between the two groups

  17. Positive resection margin and/or pathologic T3 adenocarcinoma of prostate with undetectable postoperative prostate-specific antigen after radical prostatectomy: to irradiate or not?

    International Nuclear Information System (INIS)

    Choo, Richard; Hruby, George; Hong, Julie; Hong, Eugene; DeBoer, Gerrit; Danjoux, Cyril; Morton, Gerard; Klotz, Laurence; Bhak, Edward; Flavin, Aileen

    2002-01-01

    Purpose: To evaluate the efficacy of postoperative adjuvant radiotherapy (RT) for positive resection margin and/or pathologic T3 (pT3) adenocarcinoma of the prostate with undetectable postoperative prostate-specific antigen (PSA) levels. Methods and materials: We retrospectively analyzed 125 patients with a positive resection margin and/or pT3 adenocarcinoma of the prostate who had undetectable postoperative serum PSA levels after radical prostatectomy. Seventy-three patients received postoperative adjuvant RT and 52 did not. Follow-up ranged from 1.5 to 12.0 years (median 4.2 for the irradiated group and 4.9 for the nonirradiated group). PSA outcome was available for all patients. Freedom from failure was defined as the maintenance of a serum PSA level of ≤0.2 ng/mL, as well as the absence of clinical local recurrence and distant metastasis. Results: No difference was found in the 5-year actuarial overall survival between the irradiated and nonirradiated group (94% vs. 95%). However, patients receiving adjuvant RT had a statistically superior 5-year actuarial relapse-free rate, including freedom from PSA failure, compared with those treated with surgery alone (88% vs. 65%, p=0.0013). In the irradiated group, 8 patients had relapse with PSA failure alone. None had local or distant recurrence. In the nonirradiated group, 15, 1, and 2 had PSA failure, local recurrence, and distant metastasis, respectively. On Cox regression analysis, pre-radical prostatectomy PSA level and adjuvant RT were statistically significant predictive factors for relapse, and Gleason score, extracapsular invasion, and resection margin status were not. There was a suggestion that seminal vesicle invasion was associated with an increased risk of relapse. The morbidity of postoperative adjuvant RT was acceptable, with only 2 patients developing Radiation Therapy Oncology Group Grade 3 genitourinary complications. Adjuvant RT had a minimal adverse effect on urinary continence and did not cause

  18. Assessing the variability of outcome for patients treated with localized prostate irradiation using different definitions of biochemical control

    International Nuclear Information System (INIS)

    Horwitz, Eric; Ziaja, Ellen; Vicini, Frank; Dmuchowski, Carl; Gonzalez, Jose; Stromberg, Jannifer; Brabbins, Donald; Hollander, Jay; Chen, Peter; Martinez, Alvaro

    1995-01-01

    Purpose: Biochemical control is rapidly becoming the standard to assess treatment outcome of clinically localized prostate cancer. However, no standardized definition of biochemical control has been established. We reviewed our experience treating patients with localized prostate cancer and applied 3 different commonly used definitions to estimate the variability in rates of biochemical control. Materials and Methods: Between (1(87)) and (12(91)), 480 patients with clinically localized prostate cancer received uniform treatment with external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. The median dose to the prostate was 66.6 Gy (range 58 to 70.4 Gy) through a 4 field technique. A total of 14 patients received pelvic nodal RT (median dose 45 Gy). Four hundred seventy patients had post-treatment (posttx) PSA values and 414 patients had pre-treatment (pretx) PSA values. Three different definitions of biochemical control were used: 1) Biochemical control was defined as posttx PSA nadir < 1 ng/ml within 1 year. After achieving nadir, if there were 2 consecutive increases, the patient was scored a failure at the time of the first increase; 2) Biochemical control was defined as posttx PSA nadir < 1.5 ng/ml within 1 year. After achieving nadir, if there were 2 consecutive increases, the patient was scored a failure at the time of the first increase; 3) Posttx PSA nadir < 4 ng/ml without a time limit. Once the nadir was achieved, and it did not rise above normal, the patient was considered controlled. Clinical local control was defined as no palpable prostate nodularity beyond 18 months, no new prostate nodularity, or a negative biopsy. If hormonal therapy was started, the patient was censored for biochemical failure at that time. Results: Median follow-up is 48 months (range 3 to 112 months). Pre-treatment PSA values were correlated with biochemical response using the 3 definitions of biochemical control as well as clinical local

  19. Prostate carcinomas

    International Nuclear Information System (INIS)

    Toledano, A.; Chauveinc, L.; Flam, T.; Thiounn, N.; Solignac, S.; Timbert, M.; Rosenwald, J.C.; Cosset, J.M.; Ammor, A.; Bonnetain, F.; Brenier, J.P.; Maingon, P.; Peignaux, K.; Truc, G.; Bosset, M.; Crevoisier, R. de; Tucker, S.; Dong, L.; Cheung, R.; Kuban, D.; Azria, D.; Llacer Moscardo, C.; Ailleres, N.; Allaw, A.; Serre, A.; Fenoglietto, P.; Hay, M.H.; Thezenas, S.; Dubois, J.B.; Pommier, P.; Perol, D.; Lagrange, J.L.; Richaud, P.; Brune, D.; Le Prise, E.; Azria, D.; Beckendorf, V.; Chabaud, S.; Carrie, C.; Bosset, M.; Bosset, J.F.; Maingon, P.; Ammor, A.; Crehangen, G.; Truc, G.; Peignaux, K.; Bonnetain, F.; Keros, L.; Bernier, V.; Aletti, P.; Wolf, D.; Marchesia, V.; Noel, A.; Artignan, X.; Fourneret, P.; Bacconier, M.; Shestaeva, O.; Pasquier, D.; Descotes, J.L.; Balosso, J.; Bolla, M.; Burette, R.; Corbusier, A.; Germeau, F.; Crevoisier, R. de; Dong, L.; Bonnen, M.; Cheung, R.; Tucker, S.; Kuban, D.; Crevoisier, R. de; Melancon, A.; Kuban, D.; Cheung, R.; Dong, L.; Peignaux, K.; Brenier, J.P.; Truc, G.; Bosset, M.; Ammor, A.; Barillot, I.; Maingon, P.; Molines, J.C.; Berland, E.; Cornulier, J. de; Coulet-Parpillon, A.; Cohard, C.; Picone, M.; Fourneret, P.; Artignan, X.; Daanen, V.; Gastaldo, J.; Bolla, M.; Collomb, D.; Dusserre, A.; Descotes, J.L.; Troccaz, J.; Giraud, J.Y.; Quero, L.; Hennequin, C.; Ravery, V.; Desgrandschamps, F.; Maylin, C.; Boccon-Gibod, L.; Salem, N.; Bladou, F.; Gravis, G.; Tallet, A.; Simonian, M.; Serment, G.; Salem, N.; Bladou, F.; Gravis, G.; Simonian, M.; Rosello, R.; Serment, G.

    2005-01-01

    Some short communications on the prostate carcinoma are given here. The impact of pelvic irradiation, conformation with intensity modulation, association of radiotherapy and chemotherapy reduction of side effects, imaging, doses escalation are such subjects studied and reported. (N.C.)

  20. Transducer-Mounting Fixture

    Science.gov (United States)

    Spiegel, Kirk W.

    1990-01-01

    Transducer-mounting fixture holds transducer securely against stud. Projects only slightly beyond stud after installation. Flanged transducer fits into fixture when hinged halves open. When halves reclosed, fixture tightened onto threaded stud until stud makes contact with transducer. Knurled area on fixture aids in tightening fixture on stud.

  1. Dosimetric evaluation of three adaptive strategies for prostate cancer treatment including pelvic lymph nodes irradiation.

    Science.gov (United States)

    Cantin, Audrey; Gingras, Luc; Lachance, Bernard; Foster, William; Goudreault, Julie; Archambault, Louis

    2015-12-01

    The movements of the prostate relative to the pelvic lymph nodes during intensity-modulated radiation therapy treatment can limit margin reduction and affect the protection of the organs at risk (OAR). In this study, the authors performed an analysis of three adaptive treatment strategies that combine information from both bony and gold marker registrations. The robustness of those treatments against the interfraction prostate movements was evaluated. A retrospective study was conducted on five prostate cancer patients with 7-13 daily cone-beam CTs (CBCTs). The clinical target volumes (CTVs) consisting of pelvic lymph nodes, prostate, and seminal vesicles as well as the OARs were delineated on each CBCT and the initial CT. Three adaptive strategies were analyzed. Two of these methods relied on a two-step patient positioning at each fraction. First step: a bony registration was used to deliver the nodal CTV prescription. Second step: a gold marker registration was then used either to (1) complete the dose delivered to the prostate (complement); (2) or give almost the entire prescription to the prostate with a weak dose gradient between the targets to compensate for possible motions (gradient). The third method (COR) used a pool of precalculated plans based on images acquired at previous treatment fractions. At each new fraction, a plan is selected from that pool based on the daily position of prostate center-of-mass. The dosimetric comparison was conducted and results are presented with and without the systematic shift in the prostate position on the CT planning. The adaptive strategies were compared to the current clinical standard where all fractions are treated with the initial nonadaptive plan. The minimum daily prostate D95% is improved by 2%, 9%, and 6% for the complement, the gradient, and the COR approaches, respectively, compared to the nonadaptive method. The average nodal CTV D95% remains constant across the strategies, except for the gradient approach

  2. Dosimetric evaluation of three adaptive strategies for prostate cancer treatment including pelvic lymph nodes irradiation

    International Nuclear Information System (INIS)

    Cantin, Audrey; Gingras, Luc; Archambault, Louis; Lachance, Bernard; Foster, William; Goudreault, Julie

    2015-01-01

    Purpose: The movements of the prostate relative to the pelvic lymph nodes during intensity-modulated radiation therapy treatment can limit margin reduction and affect the protection of the organs at risk (OAR). In this study, the authors performed an analysis of three adaptive treatment strategies that combine information from both bony and gold marker registrations. The robustness of those treatments against the interfraction prostate movements was evaluated. Methods: A retrospective study was conducted on five prostate cancer patients with 7–13 daily cone-beam CTs (CBCTs). The clinical target volumes (CTVs) consisting of pelvic lymph nodes, prostate, and seminal vesicles as well as the OARs were delineated on each CBCT and the initial CT. Three adaptive strategies were analyzed. Two of these methods relied on a two-step patient positioning at each fraction. First step: a bony registration was used to deliver the nodal CTV prescription. Second step: a gold marker registration was then used either to (1) complete the dose delivered to the prostate (complement); (2) or give almost the entire prescription to the prostate with a weak dose gradient between the targets to compensate for possible motions (gradient). The third method (COR) used a pool of precalculated plans based on images acquired at previous treatment fractions. At each new fraction, a plan is selected from that pool based on the daily position of prostate center-of-mass. The dosimetric comparison was conducted and results are presented with and without the systematic shift in the prostate position on the CT planning. The adaptive strategies were compared to the current clinical standard where all fractions are treated with the initial nonadaptive plan. Results: The minimum daily prostate D 95% is improved by 2%, 9%, and 6% for the complement, the gradient, and the COR approaches, respectively, compared to the nonadaptive method. The average nodal CTV D 95% remains constant across the strategies

  3. Defining an outcomes management program for definitive irradiation of prostate cancer: preliminary considerations

    International Nuclear Information System (INIS)

    Seltzer, Jonathan; Valicenti, Richard K.; Dlutowski, Mark; Corn, Benjamin W.

    1996-01-01

    PURPOSE: The advent of managed medical care presents challenges to health care providers who strive to maintain a high quality of patient care at a reasonable cost. The goals of clinical guidelines and paths are to improve the quality of patient care by using outcomes to redefine the path and to eliminate ineffective steps in the clinical algorithm. The purpose of the current endeavor was to systematically develop a clinical pathway for the radiation therapy of prostate cancer which can serve as 1) a measurement tool of operational variables such as cost and utilization, 2) a treatment tool to measure satisfaction and toxicity, 3) a research framework from which questions of efficacy can be investigated. METHODS: An initial path was constructed by the physicians based on recommendations from consensus conference of the Patterns of Care Study (PCS), and the Radiation Therapy Oncology Group (RTOG). The program was initiated by a core group of 2 attending radiation oncologists, a radiation physicist, a clinical nurse specialist, a dosimetrist, a simulation technologist, a treatment technologist, and a medical social worker. These data served as a baseline from which clinical pathway development could begin using the method of Continuous Quality Improvement (CQI) as described by Berwick (New Engl J Med 320: 53, 1989). Following the creation of a draft path, the document was circulated to other staff members of the team. Simultaneously, the Clinical Financial Management System (Transition Systems Incorporated, Boston, MA) was applied to departmental and institutional records to determine treatment patterns, utilization, toxicity, and cost for prostate cancer patients irradiated between July 1, 1995 and December 31, 1995. The aforementioned staff team as well as a seven person patient group were queried by a CQI facilitator to identify process and quality factors to be included in the clinical path. RESULTS: During the period of study, 51 patients were definitively

  4. Assessing the variability of outcome for patients treated with localized prostate irradiation using different definitions of biochemical control

    International Nuclear Information System (INIS)

    Horwitz, Eric M.; Vicini, Frank A.; Ziaja, Ellen L.; Gonzalez, Jose; Dmuchowski, Carl F.; Stromberg, Jannifer S.; Brabbins, Donald S.; Hollander, Jay; Chen, Peter Y.; Martinez, Alvaro A.

    1996-01-01

    Purpose: Biochemical control using serial posttreatment serum prostate specific antigen (PSA) levels is being increasingly used to assess treatment efficacy for localized prostate cancer. However, no standardized definition of biochemical control has been established. We reviewed our experience treating patients with localized prostate cancer and applied three different commonly used definitions of biochemical control to determine if differences in therapeutic outcome would be observed. Methods and Materials: Between January 1987 and December 1991, 480 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. The median dose to the prostate was 66.6 Gy (range 58-70.4) using a four-field or arc technique. Pretreatment and posttreatment serum PSA levels were recorded. Over 86% (414 of 480) of patients had a pretreatment PSA level available. Three different definitions of biochemical control were used: (a) PSA nadir 20), and 5-year actuarial rates of biochemical control were calculated using the three biochemical control and one clinical local control definitions. For Group 1, 5-year actuarial rates of biochemical control were 84%, 90%, and 96% for Definitions 1-3 and clinical local control, respectively. For Group 2, 5-year actuarial control rates were 45%, 54%, 74%, and 92% for the four definitions, respectively. For Group 3, 5-year actuarial control rates were 26%, 31%, 63%, and 100% for the four definitions, respectively. For Group 4, 5-year actuarial control rates were 24%, 24%, 50%, and 100% for the four definitions, respectively. Finally, for Group 5, 5-year actuarial control rates were 5%, 14%, 15%, and 89% for the four definitions, respectively. Depending on the definition used, statistically significant differences overall in outcome rates were observed. Differences between all four definitions for all pairwise comparisons ranged from 5 to 53% (p < 0

  5. In vitro co-culture experiments on prostate cancer and small intestine cells irradiated with carbon ions and x-rays

    International Nuclear Information System (INIS)

    Neubeck, C. von; Weyrather, W.-K.; Durante, M.

    2009-01-01

    Intensity modulated radiotherapy (IMRT) delivers the dose in many small irradiation fields of different beam direction to achieve a 3 dimensional tumour conformal dose overlapping with a maximum of normal tissue protection. In 2006 a study was started at GSI to treat prostate cancer patients with a boost irradiation of carbon ions in combination with an IMRT treatment administered at the Uniklinikum Heidelberg. The carbon ions are delivered in two opposing fields. So IMRT irradiation includes more normal tissue than carbon ion treatment but even here parts of the rectum and the bladder are in the irradiated field. This raises the question whether the irradiated tumor cells influence the normal cells (irradiated/ unirradiated) but also whether the normal irradiated cells influences normal tissue in a different way for carbon and photon irradiation. To study this problem, we established an in vitro co-culture model of prostate cancer and small intestine cells of the rat to simulate the patient treatment situation for analyzing tissue reaction exemplary. For characterization of the cells lines the parameters alpha and beta (linear quadratic model) for clonogenic survival were determined for x-rays and for carbon ions of different energies. For co-culture experiments unirradiated and irradiated cells were seeded together and the survival was analyzed

  6. Thermoacoustic imaging of prostate cancer: comparison to histology

    Science.gov (United States)

    Patch, S. K.; Griep, S. K.; Jacobsohn, K.; See, W. A.; Hull, D.

    2014-03-01

    Ex vivo imaging of fresh prostate specimens was performed to test the hypothesis that the thermoacoustic (TA) contrast mechanism generated with very high frequency electromagnetic (EM) irradiation is sensitive to prostate cancer. Ex vivo imaging was performed immediately after radical prostatectomy, performed as part of normal care. Irradiation pulsewidth was 700 ns and duty cycle was extremely low. Typical specific absorption rate (SAR) throughout the prostate was 70-90 kW/kg during pulsing, but time-averaged SAR was below 2 W/kg. TA pressure pulses generated by rapid heating due to EM energy deposition were detected using single element transducers. 15g/L glycine powder mixed into DI water served as acoustic couplant, which was chilled to prevent autolysis. Spatial encoding was performed by scanning in tomographic "step-and-shoot" mode, with 3 mm translation between slices and 1.8-degree rotation between tomographic views. Histology slides for 3 cases scanned with 2.25 MHz transducers were marked for comparison to TA reconstructions. These three cases showed little, moderate, and severe involvement in the histology levels surrounding the verumontanum. TA signal strength decreased with percent cancerous involvement. When VHF is used for tissue heating, the TA contrast mechanism is driven by ionic content and we observed suppressed TA signal from diseased prostate tissue in the peripheral zone. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity.

  7. A prospective three-dimensional analysis about the impact of differences in the clinical target volume in prostate cancer irradiation on normal-tissue exposure. A potential for increasing the benefit/risk ratio

    International Nuclear Information System (INIS)

    Hille, A.; Toews, N.; Schmidberger, H.; Hess, C.F.

    2005-01-01

    Background and purpose: rectal toxicity following external-beam irradiation of prostate cancer correlates with the exposed percentage of rectal volume. Recently, it has been recommended to reduce the volume of the seminal vesicles that should be included in the clinical target volume (CTV). The purpose of this study was to quantitatively assess the impact of this CTV reduction on the expected rectal and bladder dose sparing. Patients and methods: 14 patients with localized prostate cancer undergoing external-beam radiotherapy were investigated. The prostate, the prostate + entire seminal vesicles, or the prostate + proximal seminal vesicles were delineated as CTV. Treatment plans were generated and compared concerning rectum and bladder dose-volume histograms (DVHs). Results: the exposure of rectum and bladder volume was significantly lower in case of irradiation of the prostate only compared to inclusion of the proximal or entire seminal vesicles into the CTV. The reduction of the CTV from prostate + entire seminal vesicles to prostate + proximal seminal vesicles led to a significant reduction of the rectal and bladder dose exposure. Conclusion: reduction of the CTV to the prostate only, or to the prostate + proximal seminal vesicles led to significant rectal and bladder dose sparing compared to irradiation of the prostate + entire seminal vesicles. In patients with a higher risk for seminal vesicles involvement, irradiation of the prostate + proximal seminal vesicles should be preferred. In case of a need for irradiation of the entire seminal vesicles, patients should be informed about a higher risk for chronic rectal toxicity and, possibly, for bladder complications. (orig.)

  8. Assessment and management of interfractional variations in daily diagnostic-quality-CT guided prostate-bed irradiation after prostatectomy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Feng; Ahunbay, Ergun; Lawton, Colleen; Allen Li, X., E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States)

    2014-03-15

    Purpose: To quantify interfractional anatomic variations and limitations of the current practice of image-guided radiation therapy (IGRT) for prostate-bed patients and to study dosimetric benefits of an online adaptive replanning scheme that addresses the interfractional variations. Methods: Contours for the targets and organs at risk (OARs) from daily diagnostic-quality CTs acquired with in-room CT (CTVision, Siemens) were generated by populating the planning contours using an autosegmentation tool based on deformable registration (ABAS, Elekta) with manual editing for ten prostate-bed patients treated with postoperative daily CT-guided IMRT. Dice similarity coefficient (DSC) obtained by maximizing the overlap of contours for a structure between the daily and plan contours was used to quantify the organ deformation between the plan and daily CTs. Three interfractional-variation-correction schemes, the current standard practice of IGRT repositioning, a previously developed online adaptive RT (ART), and the full reoptimization, were applied to these daily CTs and a number of dose-volume quantities for the targets and organs at risk were compared for their effectiveness to account for the interfractional variations. Results: Large interfractional organ deformations in prostate-bed irradiation were seen. The mean DSCs for CTV, rectum, and bladder were 86.6 ± 5.1% (range from 61% to 97%), 77.3% ± 7.4% (range from 55% to 90%), and 75.4% ± 11.2% (range from 46% to 96%), respectively. The fractional and cumulative dose-volume quantities for CTV and PTV: V100 (volume received at least 100% prescription dose), and rectum and bladder: V{sub 45Gy} and V{sub 60Gy} (volume received at least 45 or 60 Gy), were compared for the repositioning, adaptive, reoptimization, and original plans. The fractional and cumulative dosimetric results were nearly the same. The average cumulative CTV V100 were 88.0%, 98.4%, 99.2%, and 99.3% for the IGRT, ART, reoptimization, and original plans

  9. Coalgebraising subsequential transducers

    NARCIS (Netherlands)

    H.H. Hansen (Helle); J. Adamek; C.A. Kupke (Clemens)

    2008-01-01

    htmlabstractSubsequential transducers generalise both classic deterministic automata and Mealy/Moore type state machines by combining (input) language recognition with transduction. In this paper we show that normalisation and taking differentials of subsequential transducers and their underlying

  10. Coalgebraising Subsequential Transducers

    NARCIS (Netherlands)

    Hansen, H.H.

    2008-01-01

    Subsequential transducers generalise both classic deterministic automata and Mealy/Moore type state machines by combining (input) language recognition with transduction. In this paper we show that normalisation and taking differentials of subsequential transducers and their underlying structures can

  11. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes power stages and bias configurations suitable for driving an electrostatic transducer. Measurement results of a 300 V prototype amplifier are shown. Measuring THD across a high impedance source is discussed...

  12. Advanced prostate cancer: the results of a randomized comparative trial of high dose irradiation boosting with conformal protons compared with conventional dose irradiation using photons alone

    Energy Technology Data Exchange (ETDEWEB)

    Shipley, William U; Verhey, Lynn J; Munzenrider, John E; Suit, Herman D; Urie, Marcia M; McManus, Patricia L; Young, Robert H; Shipley, Jenot W; Zietman, Anthony L; Biggs, Peter J; Heney, Niall M; Goitein, Michael

    1995-04-30

    Purpose: Following a thorough Phase I/II study, we evaluated by a Phase III trial high versus conventional dose external beam irradiation as mono-therapy for patients with Stage T3-T4 prostate cancer. Patient outcome following standard dose radiotherapy or following a 12.5% increase in total dose to 75.6 Cobalt Gray Equivalent (CGE) using a conformal perineal proton boost was compared for local tumor control, disease-free survival, and overall survival. Methods and Materials: Stage T3-T4, Nx, N0-2, M0 patients received 50.4 Gy by four-field photons and were randomized to receive either an additional 25.2 CGE by conformal protons (arm 1--the high dose arm, 103 patients, total dose 75.6 CGE) or an additional 16.8 Gy by photons (arm 2--the conventional dose arm, 99 patients, total dose 67.2 Gy). Actuarial overall survival (OS), disease-specific survival (DSS), total recurrence-free survival (TRFS), (clinically free, prostate specific antigen (PSA) less than 4ng/ml and a negative prostate rebiopsy, done in 38 patients without evidence of disease) and local control (digital rectal exam and rebiopsy negative) were evaluated. Results: The protocol completion rate was 90% for arm 1 and 97% for arm 2. With a median follow-up of 61 months (range 3 to 139 months) 135 patients are alive and 67 have died, 20 from causes other than prostate cancer. We found no significant differences in OS, DSS, TRFS or local control between the two arms. Among those completing randomized treatment (93 in arm 1 and 96 in arm 2), the local control at 5 and 8 years for arm 1 is 92% and 77%, respectively and is 80% and 60%, respectively for arm 2 (p = .089) and there are no significant differences in OS, DSS, and TRFS. The local control for the 57 patients with poorly differentiated (Gleason 4 or 5 of 5) tumors at 5 and 8 years for arm 1 is 94% and 84% and is 64% and 19% on arm 2 (p 0.0014). In patients whose digital rectal exam had normalized following treatment and underwent prostate rebiopsy

  13. Advanced prostate cancer: the results of a randomized comparative trial of high dose irradiation boosting with conformal protons compared with conventional dose irradiation using photons alone

    International Nuclear Information System (INIS)

    Shipley, William U.; Verhey, Lynn J.; Munzenrider, John E.; Suit, Herman D.; Urie, Marcia M.; McManus, Patricia L.; Young, Robert H.; Shipley, Jenot W.; Zietman, Anthony L.; Biggs, Peter J.; Heney, Niall M.; Goitein, Michael

    1995-01-01

    Purpose: Following a thorough Phase I/II study, we evaluated by a Phase III trial high versus conventional dose external beam irradiation as mono-therapy for patients with Stage T3-T4 prostate cancer. Patient outcome following standard dose radiotherapy or following a 12.5% increase in total dose to 75.6 Cobalt Gray Equivalent (CGE) using a conformal perineal proton boost was compared for local tumor control, disease-free survival, and overall survival. Methods and Materials: Stage T3-T4, Nx, N0-2, M0 patients received 50.4 Gy by four-field photons and were randomized to receive either an additional 25.2 CGE by conformal protons (arm 1--the high dose arm, 103 patients, total dose 75.6 CGE) or an additional 16.8 Gy by photons (arm 2--the conventional dose arm, 99 patients, total dose 67.2 Gy). Actuarial overall survival (OS), disease-specific survival (DSS), total recurrence-free survival (TRFS), (clinically free, prostate specific antigen (PSA) less than 4ng/ml and a negative prostate rebiopsy, done in 38 patients without evidence of disease) and local control (digital rectal exam and rebiopsy negative) were evaluated. Results: The protocol completion rate was 90% for arm 1 and 97% for arm 2. With a median follow-up of 61 months (range 3 to 139 months) 135 patients are alive and 67 have died, 20 from causes other than prostate cancer. We found no significant differences in OS, DSS, TRFS or local control between the two arms. Among those completing randomized treatment (93 in arm 1 and 96 in arm 2), the local control at 5 and 8 years for arm 1 is 92% and 77%, respectively and is 80% and 60%, respectively for arm 2 (p = .089) and there are no significant differences in OS, DSS, and TRFS. The local control for the 57 patients with poorly differentiated (Gleason 4 or 5 of 5) tumors at 5 and 8 years for arm 1 is 94% and 84% and is 64% and 19% on arm 2 (p 0.0014). In patients whose digital rectal exam had normalized following treatment and underwent prostate rebiopsy

  14. Efficacy of modest dose irradiation in combination with long-term endocrinal treatment for high-risk prostate cancer. A preliminary report

    International Nuclear Information System (INIS)

    Sasaki, Tomonari; Nakamura, Katsumasa; Shioyama, Yoshiyuki

    2004-01-01

    Although radiotherapy in combination with endocrinal manipulation has been identified as an effective treatment for patients with high-risk prostate cancer, the optimal dose for locoregional control of prostate cancer in combination with hormonal therapy has not yet been determined. The efficacy of modest doses of irradiation (60-62 Gy) combined with long-term endocrinal treatment for patients with high-risk prostate cancer (defined as a pretreatment prostate-specific antigen (PSA) level greater than 20 ng/ml or a Gleason's score of 8-10 or T3-T4 disease) was analyzed in 60 Japanese patients. The patients included in this study had received radical radiotherapy with long-term endocrinal manipulation in the period between 1993 and 2000. The median age of the patients was 70 years (range, 56-83). Neoadjuvant hormonal therapy with a median duration of 3.9 months was performed prior to radiotherapy, and hormonal therapy was continued until recurrence. A median dose of 61.4 Gy (range, 44-71.4) was delivered to the prostate. Pelvic node irradiation was performed in 49 patients (81.6%). After a median follow-up period of 28.5 months, the overall survival, cause-specific survival and biochemical relapse-free survival at 3 years were 94.4%, 96% and 89.8%, respectively. Local failure was observed in one patient, distant metastases were observed in three patients and a late toxic effect greater than Grade 2 was not observed in any patients. This study, though preliminary due to a short-term follow-up period, reveals the possibility that modest doses of irradiation combined with long-term endocrinal treatment could be an effective means of achieving excellent local control of high-risk prostate cancer. (author)

  15. Prophylactic irradiation of the male mammary gland - prevention of gynaecomastia as caused by endocrine treatment of carcinomas of the prostate

    International Nuclear Information System (INIS)

    Eggerath, E.M.

    1983-01-01

    During the period between 1975 and 1980 bilateral irradiation of the mammary glands was carried out in a total of 72 bearers of carcinomas of the prostate that had previously been confirmed on a histological basis. In no less than 35 (90%) out of the 39 patients where radiotherapy was started prior to the beginning of endocrine treatment the follow-up checks revealed a prevention or suppression of gynaecomastia as a result of radiation. The effectiveness of this treatment is described in the literature as being in the order 81% and its beneficial influences are confirmed by the data of our study. If gynaecomastia has already become established, radiotherapy holds out little promise of success and a relief of the associated discomfort is the best to be expected here. (orig./MG) [de

  16. Associations between volume changes and spatial dose metrics for the urinary bladder during local versus pelvic irradiation for prostate cancer.

    Science.gov (United States)

    Casares-Magaz, Oscar; Moiseenko, Vitali; Hopper, Austin; Pettersson, Niclas Johan; Thor, Maria; Knopp, Rick; Deasy, Joseph O; Muren, Ludvig Paul; Einck, John

    2017-06-01

    Inter-fractional variation in urinary bladder volumes during the course of radiotherapy (RT) for prostate cancer causes deviations between planned and delivered doses. This study compared planned versus daily cone-beam CT (CBCT)-based spatial bladder dose distributions, for prostate cancer patients receiving local prostate treatment (local treatment) versus prostate including pelvic lymph node irradiation (pelvic treatment). Twenty-seven patients (N = 15 local treatment; N = 12 pelvic treatment) were treated using daily image-guided RT (1.8 Gy@43-45 fx), adhering to a full bladder/empty rectum protocol. For each patient, 9-10 CBCTs were registered to the planning CT, using the clinically applied translations. The urinary bladder was manually segmented on each CBCT, 3 mm inner shells were generated, and semi and quadrant sectors were created using axial/coronal cuts. Planned and delivered DVH metrics were compared across patients and between the two groups of treatment (t-test, p bladder volume variations and the dose-volume histograms (DVH) of the bladder and its sectors were evaluated (Spearman's rank correlation coefficient, r s ). Bladder volumes varied considerably during RT (coefficient of variation: 16-58%). The population-averaged planned and delivered DVH metrics were not significantly different at any dose level. Larger treatment bladder volumes resulted in increased absolute volume of the posterior/inferior bladder sector receiving intermediate-high doses, in both groups. The superior bladder sector received less dose with larger bladder volumes for local treatments (r s  ± SD: -0.47 ± 0.32), but larger doses for pelvic treatments (r s  ± SD: 0.74 ± 0.24). Substantial bladder volume changes during the treatment course occurred even though patients were treated under a full bladder/daily image-guided protocol. Larger bladder volumes resulted in less bladder wall spared at the posterior-inferior sector, regardless the

  17. Radical prostatectomy and postoperative irradiation in patients with pathological stage C (T3) carcinoma of the prostate

    International Nuclear Information System (INIS)

    Petrovich, Zbigniew; Lieskovsky, Gary; Langholz, Bryan; Formenti, Silvia; Baert, Luc; Streeter, Oscar; Skinner, Donald G.

    1998-01-01

    Purpose: Adenocarcinoma of the prostate is the most common human cancer of internal organs. Radical surgery is regarded by many to be the treatment of choice for capsule confined disease. Since accurate preoperative assessment of tumor stage is difficult to define, many patients are subsequently found to have pathological stage C (T3) disease. These patients should be considered for adjuvant radiotherapy. Methods and Materials: A group of 201 PS C (T3) unselected patients, treated with radical prostatectomy and limited pelvic lymphadenectomy, received postoperative irradiation to the prostate bed. This radiotherapy was given between 42-90 days after surgery and consisted of a median dose of 48 Gy. Patient survival, disease free survival, time to clinical and chemical relapse and the incidence of local and systemic relapse were analyzed. The influence of multiple parameters on the treatment outcome including patient age, treatment period, clinical stage, pathological stage, Gleason's score, prostate specific antigen (PSA), radiotherapy techniques and radiation dose were examined using univariate and multivariate analysis. Follow-up ranged from 3 to 15 years, with a median of 5 years. Results: The overall 5- and 10-year actuarial survival was 92% and 83% (median > 10 years), respectively and the 5- and 10-year disease-free survival (clinical and PSA) was 67% and 53% (median > 10 years), respectively. A total of 61 (30%) patients had a recurrence, including 23 (11%) patients who had clinical and 38 (19%) who had PSA recurrence. Of the 23 patients with clinical recurrence, 10 (5%) had local recurrence, including two patients who had local and systemic recurrence. Pathological stage and Gleason's score were independently predictive of recurrence (each with p 25 ng/ml) was also an important independent factor predicting tumor recurrence, p = 0.05. All other investigated parameters were not significant in predicting tumor recurrence. This treatment program was very well

  18. Transducer handbook user's directory of electrical transducers

    CERN Document Server

    Boyle, H B

    2013-01-01

    When selecting or using a particular type of transducer or sensor, there are a number of factors which must be considered. The question is not only for what kind of measurement, but under what physical conditions, constraints of accuracy, and to meet which service requirements, is a transducer needed? This handbook is designed to meet the selection needs of anyone specifying or using transducers with an electrical output. Each transducer is described in an easy-to-use tabular format, giving all of the necessary data including operating principles, applications, range limits, errors, over-range protection, supply voltage requirements, sensitivities, cross sensitivities, temperature ranges and sensitivities and signal conditioning needs. The author has added notes that reflect his broad practical experience. Added to this is an extensive worldwide suppliers directory.

  19. Is There a Role for Pelvic Irradiation in Localized Prostate Adenocarcinoma? Update of the Long-Term Survival Results of the GETUG-01 Randomized Study

    Energy Technology Data Exchange (ETDEWEB)

    Pommier, Pascal, E-mail: Pascal.pommier@lyon.unicancer.fr [Department of Radiation Oncology, Centre Léon Bérard, Lyon (France); Chabaud, Sylvie [Department of Clinical Research and Innovation, Centre Léon Bérard, Lyon (France); Lagrange, Jean-Leon [Department of Radiation Oncology, Centre Hospitalo-Universitaire H. Mondor, Créteil (France); Richaud, Pierre [Department of Radiation Oncology, Institut Bergognié, Bordeaux (France); Le Prise, Elisabeth [Department of Radiation Oncology, Centre Eugène Marquis, Rennes (France); Wagner, Jean-Philippe [Department of Radiation Oncology, Institut Andrée Dutreix, Dunkerque (France); Azria, David [Department of Radiation Oncology, Institut de Cancérologie de Montpellier, Montpellier (France); Beckendorf, Veronique [Department of Radiation Oncology, Institut de Cancérologie de Lorraine, Nancy (France); Suchaud, Jean-Philippe [Department of Radiation Oncology, Centre Hospitalier de Roanne, Roanne (France); Bernier, Valerie [Department of Radiation Oncology, Centre Oscar Lambret, Lille (France); Perol, David [Department of Clinical Research and Innovation, Centre Léon Bérard, Lyon (France); Carrie, Christian [Department of Radiation Oncology, Centre Léon Bérard, Lyon (France)

    2016-11-15

    Purpose: To report the long-term results of the French Genitourinary Study Group (GETUG)-01 study in terms of event-free survival (EFS) and overall survival (OS) and assess the potential interaction between hormonotherapy and pelvic nodes irradiation. Patients and Methods: Between December 1998 and June 2004, 446 patients with T1b-T3, N0pNx, M0 prostate carcinoma were randomly assigned to either pelvic nodes and prostate or prostate-only radiation therapy. Patients were stratified into 2 groups: “low risk” (T1-T2 and Gleason score 6 and prostate-specific antigen <3× the upper normal limit of the laboratory) (92 patients) versus “high risk” (T3 or Gleason score >6 or prostate-specific antigen >3× the upper normal limit of the laboratory). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for high-risk patients. Radiation therapy was delivered with a 3-dimensional conformal technique, using a 4-field technique for the pelvic volume (46 Gy). The total dose recommended to the prostate moved from 66 Gy to 70 Gy during the course of the study. Criteria for EFS included biologic prostate-specific antigen recurrences and/or a local or metastatic progression. Results: With a median follow-up of 11.4 years, the 10-year OS and EFS were similar in the 2 treatment arms. A higher but nonsignificant EFS was observed in the low-risk subgroup in favor of pelvic nodes radiation therapy (77.2% vs 62.5%; P=.18). A post hoc subgroup analysis showed a significant benefit of pelvic irradiation when the risk of lymph node involvement was <15% (Roach formula). This benefit seemed to be limited to patients who did not receive hormonal therapy. Conclusion: Pelvic nodes irradiation did not statistically improve EFS or OS in the whole population but may be beneficial in selected low- and intermediate-risk prostate cancer patients treated with exclusive radiation therapy.

  20. Handbook of force transducers

    CERN Document Server

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  1. Comparison of megavoltage position verification for prostate irradiation based on bony anatomy and implanted fiducials

    International Nuclear Information System (INIS)

    Nederveen, Aart J.; Dehnad, Homan; Heide, Uulke A. van der; Moorselaar, R. Jeroen A. van; Hofman, Pieter; Lagendijk, Jan J.W.

    2003-01-01

    Purpose: The patient position during radiotherapy treatment of prostate cancer can be verified with the help of portal images acquired during treatment. In this study we quantify the clinical consequences of the use of image-based verification based on the bony anatomy and the prostate target itself. Patients and methods: We analysed 2025 portal images and 23 computed tomography (CT) scans from 23 patients with prostate cancer. In all patients gold markers were implanted prior to CT scanning. Statistical data for both random and systematic errors were calculated for displacements of bones and markers and we investigated the effectiveness of an off-line correction protocol. Results: Standard deviations for systematic marker displacement are 2.4 mm in the lateral (LR) direction, 4.4 mm in the anterior-posterior (AP) direction and 3.7 mm in the caudal-cranial direction (CC). Application of off-line position verification based on the marker positions results in a shrinkage of the systematic error to well below 1 mm. Position verification based on the bony anatomy reduces the systematic target uncertainty to 50% in the AP direction and in the LR direction. No reduction was observed in the CC direction. For six out of 23 patients we found an increase of the systematic error after application of bony anatomy-based position verification. Conclusions: We show that even if correction based on the bony anatomy is applied, considerable margins have to be set to account for organ motion. Our study highlights that for individual patients the systematic error can increase after application of bony anatomy-based position verification, whereas the population standard deviation will decrease. Off-line target-based position verification effectively reduces the systematic error to well below 1 mm, thus enabling significant margin reduction

  2. Investigation of normal tissue complication probabilities in prostate and partial breast irradiation radiotherapy techniques

    International Nuclear Information System (INIS)

    Bezak, E.; Takam, R.; Bensaleh, S.; Yeoh, E.; Marcu, L.

    2011-01-01

    Full text: Normal- Tissue-Complication Probabilities of rectum, bladder and urethra following various radiation techniques for prostate cancer were evaluated using the relative-seriality and Lyman models. NTCPs of lungs, heart and skin, their dependence on sourceposition, balloon-deformation were also investigated for HDR mammosite brachytherapy. The prostate treatment techniques included external three dimentional conformal-radiotherapy, Low-Dose-Rate brachytherapy (1-125), High-Dose-Rate brachytherapy (Ir-I92). Dose- Volume-Histograms of critical structures for prostate and breast radiotherapy, retrieved from corresponding treatment planning systems, were converted to Biological Effective Dose (BEffD)-based and Equivalent Dose(Deq)-based DVHs to account for differences in radiation delivery and fractionation schedule. Literature-based model parameters were used to calculate NTCPs. Hypofractionated 3D-CRT (2.75 Gy/fraction, total dose 55 Gy) NTCPs of rectum, bladder and urethra were less than those for standard fractionated 4-field 3D-CRT (2-Gy/fraction, 64 Gy) and dose-escalated 4- and 5-field 3D-CRT (74 Gy). Rectal and bladder NTCPs (5.2% and 6.6%) following the dose-escalated 4-field 3D-CRT (74 Gy) were the highest among analyzed techniques. The average NTCP for rectum and urethra were 0.6% and 24.7% for LDRBT and 0.5% and 11.2% for HDR-BT. For Mammosite, NTCP was estimated to be 0.1 %, 0.1 %, 1.2% and 3.5% for skin desquamation, erythema, telangiectasia and fibrosis respectively (the source positioned at the balloon centre). A 4 mm Mammosite-balloon deformation leads to overdosing of PTV regions by ∼40%, resulting in excessive skin dose and increased NTCP. Conclusions Prostate brachytherapy resulted in NTCPs lower compared to external beam techniques. Mammosite-brachytherapy resulted in no heart/lung complications regardless of balloon deformation. However, 4 mm deformation caused 0.6% increase in tissue fibrosis NTCP.

  3. Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

    Science.gov (United States)

    Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

    2016-01-01

    The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter

  4. Margin to CTV in simultaneous irradiation of treatment volumes attache to various anatomical frameworks: The paradigm of the CA. Of prostate in high risk with indication of lymph node irradiation

    International Nuclear Information System (INIS)

    Sanz Freire, C. J.; Perez Echaguen, S.; Collado chamorro, P.; Diaz Pascual, V.; Vazquez Galinanes, A.; Ossola Lentati, G. A.

    2013-01-01

    The triple objective of this work is: 1 check the effect on the positioning of the GGPP of corrections on the position of the prostate in simultaneous irradiation guided through daily image and its relationship with the filling of rectum and bladder 2. check if employees standard margins for CTV GGPP are valid for this technique 3 calculate the necessary extension of the margin to 2. is not verified. (Author)

  5. Conformal Brachytherapy Boost To External Beam Irradiation For Clinically Localized High Risk Prostate Cancer

    International Nuclear Information System (INIS)

    Dattoli, Michael J.; Wasserman, Stuart G.; Koval, John M.; Sorace, Richard A.; Cash, Jennifer; Wallner, Kent E.

    1995-01-01

    Purpose: To evaluate the efficacy of using a Pd-103 implant as a boost in conjunction with external beam radiotherapy (EBRT) in patients having prostate cancer associated with adverse features. Materials and Methods: 114 consecutive high risk patients have been treated with combination EBRT and Pd-103 implant. 70 patients with follow-up range of 12-42 months (median 24 months) form the basis of this report. Each patient had at least one of the following risk factors for extra-capsular disease extension: Stage T2b or greater ((66(70))), Gleason score ≥ 7 ((38(70))), significantly elevated PSA (typically > 15 ng/ml)((30(70))) or elevated serum prostatic acid phosphatase (SPAP)((17(70))). Patients received median 4140 cGy EBRT to a limited pelvic field followed by a Pd-103 boost (median prescription dose: 8000 cGy). All patients have been followed in a prospective fashion with respect to PSA response, clinical evidence of disease progression and complications. Criteria for biochemical failure was relatively strict, and was analyzed using both, PSA > 2.0 and PSA > 1.0 as end points. Patients whose PSA was still decreasing at last follow-up were censored at that time. Freedom from failure rates were calculated by the method of Kaplan and Meier. Differences between groups were determined by the Log-rank method. Sexual potency was defined as the ability to attain and maintain an erection sufficient for intercourse. Results: Actuarial freedom from biochemical failure at 3 years after treatment was 90% and 78%, when PSA > 2 and PSA > 1 were used, respectively. There are no documented local relapses. 4 patients failed distantly, and all other failures are based solely on rising PSA values. Biochemical failure was higher in patients having Gleason score ≥ 7 (p=0.001), those with PSA >20 (p=0.014) and in those with elevated SPAP (p=0.007). The primary treatment related morbity was temporary, Grade 1-2 urinary symptoms. No patient developed rectal ulceration or prostatic

  6. Conformal Brachytherapy Boost To External Beam Irradiation For Clinically Localized High Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dattoli, Michael J; Wasserman, Stuart G; Koval, John M; Sorace, Richard A; Cash, Jennifer; Wallner, Kent E

    1995-07-01

    Purpose: To evaluate the efficacy of using a Pd-103 implant as a boost in conjunction with external beam radiotherapy (EBRT) in patients having prostate cancer associated with adverse features. Materials and Methods: 114 consecutive high risk patients have been treated with combination EBRT and Pd-103 implant. 70 patients with follow-up range of 12-42 months (median 24 months) form the basis of this report. Each patient had at least one of the following risk factors for extra-capsular disease extension: Stage T2b or greater ((66(70))), Gleason score {>=} 7 ((38(70))), significantly elevated PSA (typically > 15 ng/ml)((30(70))) or elevated serum prostatic acid phosphatase (SPAP)((17(70))). Patients received median 4140 cGy EBRT to a limited pelvic field followed by a Pd-103 boost (median prescription dose: 8000 cGy). All patients have been followed in a prospective fashion with respect to PSA response, clinical evidence of disease progression and complications. Criteria for biochemical failure was relatively strict, and was analyzed using both, PSA > 2.0 and PSA > 1.0 as end points. Patients whose PSA was still decreasing at last follow-up were censored at that time. Freedom from failure rates were calculated by the method of Kaplan and Meier. Differences between groups were determined by the Log-rank method. Sexual potency was defined as the ability to attain and maintain an erection sufficient for intercourse. Results: Actuarial freedom from biochemical failure at 3 years after treatment was 90% and 78%, when PSA > 2 and PSA > 1 were used, respectively. There are no documented local relapses. 4 patients failed distantly, and all other failures are based solely on rising PSA values. Biochemical failure was higher in patients having Gleason score {>=} 7 (p=0.001), those with PSA >20 (p=0.014) and in those with elevated SPAP (p=0.007). The primary treatment related morbity was temporary, Grade 1-2 urinary symptoms. No patient developed rectal ulceration or prostatic

  7. Conformal irradiation of the prostate: estimating long-term rectal bleeding risk using dose-volume histograms

    International Nuclear Information System (INIS)

    Hartford, Alan C.; Niemierko, Andrzej; Adams, Judith A.; Urie, Marcia M.; Shipley, William U.

    1996-01-01

    Purpose: Dose-volume histograms (DVHs) may be very useful tools for estimating probability of normal tissue complications (NTCP), but there is not yet an agreed upon method for their analysis. This study introduces a statistical method of aggregating and analyzing primary data from DVHs and associated outcomes. It explores the dose-volume relationship for NTCP of the rectum, using long-term data on rectal wall bleeding following prostatic irradiation. Methods and Materials: Previously published data were reviewed and updated on 41 patients with Stages T3 and T4 prostatic carcinoma treated with photons followed by perineal proton boost, including dose-volume histograms (DVHs) of each patient's anterior rectal wall and data on the occurrence of postirradiation rectal bleeding (minimum FU > 4 years). Logistic regression was used to test whether some individual combination of dose and volume irradiated might best separate the DVHs into categories of high or low risk for rectal bleeding. Further analysis explored whether a group of such dose-volume combinations might be superior in predicting complication risk. These results were compared with results of the 'critical volume model', a mathematical model based on assumptions of underlying radiobiological interactions. Results: Ten of the 128 tested dose-volume combinations proved to be 'statistically significant combinations' (SSCs) distinguishing between bleeders (14 out of 41) and nonbleeders (27 out of 41), ranging contiguously between 60 CGE (Cobalt Gray Equivalent) to 70% of the anterior rectal wall and 75 CGE to 30%. Calculated odds ratios for each SSC were not significantly different across the individual SSCs; however, analysis combining SSCs allowed segregation of DVHs into three risk groups: low, moderate, and high. Estimates of probabilities of normal tissue complications (NTCPs) based on these risk groups correlated strongly with observed data (p = 0.003) and with biomathematical model-generated NTCPs

  8. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    transducers can be concisely represented in Haskell, and demonstrate the benefits of utilising such an approach with a number of examples. In particular, tree transducers afford a modular programming style as they can be easily composed and manipulated. Our Haskell representation generalises the original...

  9. Crossflow force transducer

    International Nuclear Information System (INIS)

    Mulcahy, T.M.

    1982-05-01

    A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related

  10. The study of irradiation combined with targeted suicide gene therapy for prostate cancer xenografts

    International Nuclear Information System (INIS)

    Lu Xueguan; Milas, L.

    2007-01-01

    Objective: To study whether RGD-4C AAVP HSV-TK/GCV, one of suicide gene therapy targeting to Integrin αv, can enhance radiotherapeutic effect for DU145 prostate cancer xenografts or not. Methods: When the diameter of tumor in 48 nude mice bearing DU145 prostate cancer in the right leg attained 6.0 mm (5.8-6.3 mm), the mice were entered into the experiment. There were 6 experimental groups (8 mice per group), including the control, radiotherapy only (RT), RGD-4C AAVP HSV-TK/GCV only (Targeted, RGD-4C), AAVP HSV-TK/GCV (Non-targeted, non RGD-4C ), radiotherapy plus RGD- 4C AAVP HSV-TK/GCV(XRT + RGD-4C) and radiotherapy plus AAVP HSV-TK/GCV group (XRT + Non RGD-4C). The effect of treatment was assessed by tumor growth delay ( the time required when tumor grew from 6.0 mm to 12.0 mm) and tumor cure. Results: Five mice died during the treatment course. There were 6 mice without tumor after treatment, including 1 in RT group, 1 in RGD-4C group, 1 in non RGD-4C group and 3 in XRT + RGD-4C group, respectively. For tumor growth delay analysis in 37 mice, the absolute growth delay (AGD) for RGD-4C, non RGD-4C and RT group was 24.4 ± 9.0, 22.6±11.3 and 28.3 ±5.5 days, respectively. When RGD-4C AAVP HSV-TK/GCV or AAVP HSV-TK/GCV combined with radiotherapy, their AGD was 64.7±23.8 and 35.4±9.6 days, and nominal growth delay (NGD) was 40.3 ± 23.8 and 12.8 ± 9.6 days, respectively. The enhancement factor of RGD-4C AAVP HSV-TK/GCV and AAVP HSV-TK/GCV for radiotherapy were 1.42 and 0.45. Conclusion: RGD-4C AAVP HSV-TK/GCV can enhance radiotherapeutic effect for DU145 prostate cancer xenografts. Further study is needed. (authors)

  11. Intermittent hormonal therapy in the treatment of post-irradiation residual/recurrent prostate cancer

    International Nuclear Information System (INIS)

    Williams, Aaron O; Kocherill, Paul G; Wallace, Michelle; Forman, Jeffrey D

    1996-01-01

    Purpose: To evaluate the efficacy and toxicity of intermittent hormonal therapy in the treatment of residual/recurrent prostate cancer. Materials and Methods: Seventeen patients with biochemical evidence of residual/recurrent prostate cancer were initially treated with radiation therapy (RT)(13), neo-adjuvant hormonal therapy and RT (3), or RT following prostatectomy (1). The mean follow-up time was 19.4 months from the initiation of hormonal therapy. Hormonal therapy consisted of an LH-RH agonist alone (7), an anti-androgen alone (1) or a combination of both (9). Hormonal therapy was continued until the prostatic specific antigen (PSA) level became undetectable. IHT was reinstituted when the PSA reached a pre-determined level, usually greater than or equal to 10ng/ml. Results: The mean time from completion of primary treatment to the initiation of hormonal therapy was 32.5 months. The mean PSA at the start of the first cycle of hormonal therapy was 43.9ng/ml, the second cycle, 11.9ng/ml and the third cycle, 24ng/ml. The mean PSA levels at the end of the first and second cycle of hormonal therapy were .48 and .42ng/ml, respectively. No patient has yet completed the third cycle of hormonal therapy. The average duration of hormonal therapy was 10 months for the first cycle and 4 months for the second cycle. The mean intermittent time off hormones were 9.3 months between cycles 1 and 2, and 10 months between cycles 2 and 3. No patient has yet become refractory to hormonal therapy. Currently all patients are alive. All patients experienced hot flashes and decreased libido at varying degrees during treatment. Thirty-five percent experienced gynecomastia. During the intervals between hormonal therapy, most patients reported a decrease in hot flashes. Conclusion: This analysis supplies preliminary evidence that intermittent hormonal therapy is a viable option in patients with biochemical evidence of disease following initial therapy. It is associated with less treatment

  12. Modeling of ultrasound transducers

    DEFF Research Database (Denmark)

    Bæk, David

    This Ph.D. dissertation addresses ultrasound transducer modeling for medical ultrasound imaging and combines the modeling with the ultrasound simulation program Field II. The project firstly presents two new models for spatial impulse responses (SIR)s to a rectangular elevation focused transducer...... (REFT) and to a convex rectangular elevation focused transducer (CREFT). These models are solvable on an analog time scale and give exact smooth solutions to the Rayleigh integral. The REFT model exhibits a root mean square (RMS) error relative to Field II predictions of 0.41 % at 3400 MHz, and 1.......37 % at 100MHz. The CREFT model exhibits a RMS deviation of 0.01 % relative to the exact numerical solution on a CREFT transducer. A convex non-elevation focused, a REFT, and a linear flat transducer are shown to be covered with the CREFT model as well. Pressure pulses calculated with a one...

  13. Characterization of adenoviral transduction profile in prostate cancer cells and normal prostate tissue.

    Science.gov (United States)

    Ai, Jianzhong; Tai, Phillip W L; Lu, Yi; Li, Jia; Ma, Hong; Su, Qin; Wei, Qiang; Li, Hong; Gao, Guangping

    2017-09-01

    Prostate diseases are common in males worldwide with high morbidity. Gene therapy is an attractive therapeutic strategy for prostate diseases, however, it is currently underdeveloped. As well known, adeno virus (Ad) is the most widely used gene therapy vector. The aims of this study are to explore transduction efficiency of Ad in prostate cancer cells and normal prostate tissue, thus further providing guidance for future prostate pathophysiological studies and therapeutic development of prostate diseases. We produced Ad expressing enhanced green fluorescence protein (EGFP), and characterized the transduction efficiency of Ad in both human and mouse prostate cancer cell lines in vitro, as well as prostate tumor xenograft, and wild-type mouse prostate tissue in vivo. Ad transduction efficiency was determined by EGFP fluorescence using microscopy and flow cytometry. Cell type-specific transduction was examined by immunofluorescence staining of cell markers. Our data showed that Ad efficiently transduced human and mouse prostate cancer cells in vitro in a dose dependent manner. Following intratumoral and intraprostate injection, Ad could efficiently transduce prostate tumor xenograft and the major prostatic cell types in vivo, respectively. Our findings suggest that Ad can efficiently transduce prostate tumor cells in vitro as well as xenograft and normal prostate tissue in vivo, and further indicate that Ad could be a potentially powerful toolbox for future gene therapy of prostate diseases. © 2017 Wiley Periodicals, Inc.

  14. Prediction of the cumulated dose for external beam irradiation of prostate cancer patients with 3D-CRT technique

    Directory of Open Access Journals (Sweden)

    Giżyńska Marta

    2016-03-01

    Full Text Available Nowadays in radiotherapy, much effort is taken to minimize the irradiated volume and consequently minimize doses to healthy tissues. In our work, we tested the hypothesis that the mean dose distribution calculated from a few first fractions can serve as prediction of the cumulated dose distribution, representing the whole treatment. We made our tests for 25 prostate cancer patients treated with three orthogonal fields technique. We did a comparison of dose distribution calculated as a sum of dose distribution from each fraction with a dose distribution calculated with isocenter shifted for a mean setup error from a few first fractions. The cumulative dose distribution and predicted dose distributions are similar in terms of gamma (3 mm 3% analysis, under condition that we know setup error from seven first fractions. We showed that the dose distribution calculated for the original plan with the isocenter shifted to the point, defined as the original isocenter corrected of the mean setup error estimated from the first seven fractions supports our hypothesis, i.e. can serve as a prediction for cumulative dose distribution.

  15. Chronic effects of therapeutic irradiation for localized prostatic carcinoma on anorectal function

    International Nuclear Information System (INIS)

    Yeoh, Eric E.K.; Botten, Rochelle; Russo, Antonietta; McGowan, Roz; Fraser, Robert; Roos, Daniel; Penniment, Michael; Borg, Martin; Sun Weiming

    2000-01-01

    Purpose: To evaluate prospectively the prevalence and pathophysiology of anorectal dysfunction following radiation therapy (RTH) for localized carcinoma of the prostate. Methods and Materials: The following parameters of anorectal function were evaluated in each of 35 patients (aged 55-82 years) with localized prostatic carcinoma treated with RTH either to a dose of 55 Gy/20 fractions/4 weeks (18 patients) or 64 Gy/32 fractions/6.5 weeks (17 patients), before RTH and 4-6 weeks and at a mean (± SD) of 1.4 (± 0.2) years after its completion: (1) anorectal symptoms (questionnaire), (2) anorectal pressures at rest and in response to voluntary squeeze and increases in intra-abdominal pressure (multiport anorectal manometry), (3) rectal sensation (balloon distension) and (4) anal sphincteric morphology (endoanal ultrasound). Results: All but 1 patient completed three series of measurements. RTH had no effect on anal sphincteric morphology. The increase in frequency of defecation and fecal urgency and incontinence scores previously reported in the patients 4-6 weeks after RTH were sustained 1 year later (p < 0.001, p < 0.001, and p < 0.05, cf. baseline, respectively). At this time, 56% (19 of 34), 50% (17 of 34) and 26% (9 of 34) of the patients had increased frequency of defecation, fecal urgency, and incontinence, respectively. Decreases in anal sphincteric pressures at rest and in response to voluntary squeeze recorded in the patients 4-6 weeks after RTH were not sustained 1 year later but the volumes of rectal distension associated with perception of the stimulus and desire to defecate were lower compared with baseline volumes (p < 0.01 and p < 0.05, respectively), reflecting heightened rectal sensitivity in the patients. There was no difference in measurements between the two radiation dose regimens. Univariate logistical regression analysis was performed on patients who had experienced increased symptom scores or decreases in recorded motor and sensory manometric

  16. Prostate carcinomas; Cancer de la prostate

    Energy Technology Data Exchange (ETDEWEB)

    Toledano, A.; Chauveinc, L.; Flam, T.; Thiounn, N.; Solignac, S.; Timbert, M.; Rosenwald, J.C.; Cosset, J.M.; Ammor, A.; Bonnetain, F.; Brenier, J.P.; Maingon, P.; Peignaux, K.; Truc, G.; Bosset, M.; Crevoisier, R. de; Tucker, S.; Dong, L.; Cheung, R.; Kuban, D.; Azria, D.; Llacer Moscardo, C.; Ailleres, N.; Allaw, A.; Serre, A.; Fenoglietto, P.; Hay, M.H.; Thezenas, S.; Dubois, J.B.; Pommier, P.; Perol, D.; Lagrange, J.L.; Richaud, P.; Brune, D.; Le Prise, E.; Azria, D.; Beckendorf, V.; Chabaud, S.; Carrie, C.; Bosset, M.; Bosset, J.F.; Maingon, P.; Ammor, A.; Crehangen, G.; Truc, G.; Peignaux, K.; Bonnetain, F.; Keros, L.; Bernier, V.; Aletti, P.; Wolf, D.; Marchesia, V.; Noel, A.; Artignan, X.; Fourneret, P.; Bacconier, M.; Shestaeva, O.; Pasquier, D.; Descotes, J.L.; Balosso, J.; Bolla, M.; Burette, R.; Corbusier, A.; Germeau, F.; Crevoisier, R. de; Dong, L.; Bonnen, M.; Cheung, R.; Tucker, S.; Kuban, D.; Crevoisier, R. de; Melancon, A.; Kuban, D.; Cheung, R.; Dong, L.; Peignaux, K.; Brenier, J.P.; Truc, G.; Bosset, M.; Ammor, A.; Barillot, I.; Maingon, P.; Molines, J.C.; Berland, E.; Cornulier, J. de; Coulet-Parpillon, A.; Cohard, C.; Picone, M.; Fourneret, P.; Artignan, X.; Daanen, V.; Gastaldo, J.; Bolla, M.; Collomb, D.; Dusserre, A.; Descotes, J.L.; Troccaz, J.; Giraud, J.Y.; Quero, L.; Hennequin, C.; Ravery, V.; Desgrandschamps, F.; Maylin, C.; Boccon-Gibod, L.; Salem, N.; Bladou, F.; Gravis, G.; Tallet, A.; Simonian, M.; Serment, G.; Salem, N.; Bladou, F.; Gravis, G.; Simonian, M.; Rosello, R.; Serment, G

    2005-11-15

    Some short communications on the prostate carcinoma are given here. The impact of pelvic irradiation, conformation with intensity modulation, association of radiotherapy and chemotherapy reduction of side effects, imaging, doses escalation are such subjects studied and reported. (N.C.)

  17. High-precision prostate cancer irradiation by clinical application of an offline patient setup verification procedure, using portal imaging

    International Nuclear Information System (INIS)

    Bel, Arjan; Vos, Pieter H.; Rodrigus, Patrick T. R.; Creutzberg, Carien L.; Visser, Andries G.; Stroom, Joep C.; Lebesque, Joos V.

    1996-01-01

    Purpose: To investigate in three institutions, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Huis [AvL]), Dr. Daniel den Hoed Cancer Center (DDHC), and Dr, Bernard Verbeeten Institute (BVI), how much the patient setup accuracy for irradiation of prostate cancer can be improved by an offline setup verification and correction procedure, using portal imaging. Methods and Materials: The verification procedure consisted of two stages. During the first stage, setup deviations were measured during a number (N max ) of consecutive initial treatment sessions. The length of the average three dimensional (3D) setup deviation vector was compared with an action level for corrections, which shrunk with the number of setup measurements. After a correction was applied, N max measurements had to be performed again. Each institution chose different values for the initial action level (6, 9, and 10 mm) and N max (2 and 4). The choice of these parameters was based on a simulation of the procedure, using as input preestimated values of random and systematic deviations in each institution. During the second stage of the procedure, with weekly setup measurements, the AvL used a different criterion ('outlier detection') for corrective actions than the DDHC and the BVI ('sliding average'). After each correction the first stage of the procedure was restarted. The procedure was tested for 151 patients (62 in AvL, 47 in DDHC, and 42 in BVI) treated for prostate carcinoma. Treatment techniques and portal image acquisition and analysis were different in each institution. Results: The actual distributions of random and systematic deviations without corrections were estimated by eliminating the effect of the corrections. The percentage of mean (systematic) 3D deviations larger than 5 mm was 26% for the AvL and the DDHC, and 36% for the BVI. The setup accuracy after application of the procedure was considerably improved (percentage of mean 3D deviations larger than 5 mm was 1.6% in the

  18. Dose-Volume Relationships for Acute Bowel Toxicity in Patients Treated With Pelvic Nodal Irradiation for Prostate Cancer

    International Nuclear Information System (INIS)

    Fiorino, Claudio; Alongi, Filippo; Perna, Lucia; Broggi, Sara; Cattaneo, Giovanni Mauro; Cozzarini, Cesare; Di Muzio, Nadia; Fazio, Ferruccio; Calandrino, Riccardo

    2009-01-01

    Purpose: To find correlation between dose-volume histograms (DVHs) of the intestinal cavity (IC) and moderate-severe acute bowel toxicity in men with prostate cancer treated with pelvic nodal irradiation. Methods and Materials: The study group consisted of 191 patients with localized prostate cancer who underwent whole-pelvis radiotherapy with radical or adjuvant/salvage intent during January 2004 to November 2007. Complete planning/clinical data were available in 175 of these men, 91 of whom were treated with a conventional four-field technique (50.4 Gy, 1.8 Gy/fraction) and 84 of whom were treated with IMRT using conventional Linac (n = 26, 50.4 Gy, 1.8 Gy/fraction) or Helical TomoTherapy (n = 58, 50-54 Gy, 1.8-2 Gy/fraction). The IC outside the planning target volume (PTV) was contoured and the DVH for the first 6 weeks of treatment was recovered in all patients. The correlation between a number of clinical and DVH (V10-V55) variables and toxicity was investigated in univariate and multivariate analyses. The correlation between DVHs for the IC outside the PTV and DVHs for the whole IC was also assessed. Results: Twenty-two patients experienced toxicity (3/22 in the IMRT/tomotherapy group). Univariate analyses showed a significant correlation between V20-V50 and toxicity (p = 0.0002-0.001), with a higher predictive value observed for V40-V50. Previous prostatectomy (p = 0.066) and abdominal/pelvic surgery (p = 0.12) also correlated with toxicity. Multivariate analysis that included V45, abdominal/pelvic surgery, and prostatectomy showed that the most predictive parameters were V45 (p = 0.002) and abdominal/pelvic surgery (p = 0.05, HR = 2.4) Conclusions: Our avoidance IMRT approach drastically reduces the incidence of acute bowel toxicity. V40-V50 of IC and, secondarily, previous abdominal/pelvic surgery were the main predictors of acute bowel toxicity.

  19. Smart transducer with radiomodem

    Science.gov (United States)

    Pugach, V. N.; Voronin, E. L.

    2018-04-01

    Systems for measuring different parameters enabling metering and wireless data transmission are an urgent problem in the industry. One of the most promising solutions is the developments of metering instruments enabling radio-link and GSM data transmission. The article describes a transducer operating with temperature sensors of different types as well as with the sensors of other physical values with the output signal represented as current or voltage with subsequent measurement data transmission from the transducer to the computer via radio-link. The article provides transducer measurement accuracy check. The work confirmed the claimed temperature measurement accuracy, noted a stable data transmission via radio link and convenience of work with the transducer and software.

  20. Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

    International Nuclear Information System (INIS)

    Shih, Helen A.; Harisinghani, Mukesh; Zietman, Anthony L.; Wolfgang, John A.; Saksena, Mansi; Weissleder, Ralph

    2005-01-01

    Purpose: Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard 'four-field box.' We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer. Methods and Materials: Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to a common template based on its relation to skeletal or vascular anatomy. Results: Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort. Conclusions: Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities

  1. Peripheral photon and neutron doses from prostate cancer external beam irradiation.

    Science.gov (United States)

    Bezak, Eva; Takam, Rundgham; Marcu, Loredana G

    2015-12-01

    Peripheral photon and neutron doses from external beam radiotherapy (EBRT) are associated with increased risk of carcinogenesis in the out-of-field organs; thus, dose estimations of secondary radiation are imperative. Peripheral photon and neutron doses from EBRT of prostate carcinoma were measured in Rando phantom. (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P glass-rod thermoluminescence dosemeters (TLDs) were inserted in slices of a Rando phantom followed by exposure to 80 Gy with 18-MV photon four-field 3D-CRT technique. The TLDs were calibrated using 6- and 18-MV X-ray beam. Neutron dose equivalents measured with CR-39 etch-track detectors were used to derive readout-to-neutron dose conversion factor for (6)LiF:Mg,Cu,P TLDs. Average neutron dose equivalents per 1 Gy of isocentre dose were 3.8±0.9 mSv Gy(-1) for thyroid and 7.0±5.4 mSv Gy(-1) for colon. For photons, the average dose equivalents per 1 Gy of isocentre dose were 0.2±0.1 mSv Gy(-1) for thyroid and 8.1±9.7 mSv Gy(-1) for colon. Paired (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P TLDs can be used to measure photon and neutron doses simultaneously. Organs in close proximity to target received larger doses from photons than those from neutrons whereas distally located organs received higher neutron versus photon dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Calibration of acoustic emission transducers

    International Nuclear Information System (INIS)

    Leschek, W.C.

    1976-01-01

    A method is described for calibrating an acoustic emission transducer to be used in a pre-set frequency range. The absolute reception sensitivity of a reference transducer is determined at frequencies selected within the frequency range. The reference transducer and the acoustic emission transducer are put into acoustic communication with the surface of a limited acoustic medium representing an equivalent acoustic load appreciably identical to that of the medium in which the use of the acoustic emission transducer is intended. A blank random acoustic noise is emitted in the acoustic medium in order to establish a diffuse and reverberating sound field, after which the output responses of the reference transducer and of the acoustic emission transducer are obtained with respect to the diffuse and reverberating field, for selected frequencies. The output response of the acoustic emission transducer is compared with that of the reference transducer for the selected frequencies, so as to determine the reception sensitivity of the acoustic emission transducer [fr

  3. NMR signal transducer

    International Nuclear Information System (INIS)

    Kucheryaev, A.G.; Oliferchuk, N.L.

    1975-01-01

    A signal transducer of nuclear magnetic resonance for simultaneously measuring frequency and intensitivity of two various isotope signals, which are in one specimen is described. The transducer represents radiofrequency circuit with two resonance frequences, which is common for two autodyne generators. To decrease measuring time and to increase recording diagram stability the radiofrequency circuit has LC netork, in the inductivity of which investigated specimen is located; a circuit variable capacity is connected in parallel with one of the autodyne generators. Besides the radiofrequency circuit has an inductance coil in series with a standard specimen inside as well as a variable capacitor connected in parallel with the second autodyne generator. An amplitude of oscillation of each resonance frequency is controlled and adjusted separately. The transducer described can be used for the measurement of a nuclei concentration, isotope concentration and for the spin determination

  4. Partial-Body Irradiation in Patients with Prostate Cancer Treated with IMRT Has Little Effect on the Composition of Serum Proteome.

    Science.gov (United States)

    Pietrowska, Monika; Jelonek, Karol; Polanska, Joanna; Wojakowska, Anna; Marczak, Lukasz; Chawinska, Ewa; Chmura, Aleksanda; Majewski, Wojciech; Miszczyk, Leszek; Widlak, Piotr

    2015-06-30

    Partial body irradiation during cancer radiotherapy (RT) induces a response of irradiated tissues that could be observed at the level of serum proteome. Here we aimed to characterize the response to RT in group of patients treated because of prostate cancer. Five consecutive blood samples were collected before, during, and after the end of RT in a group of 126 patients who received definitive treatment with a maximum dose of 76 Gy. Serum peptidome, which was profiled in the 2000-16,000 Da range using MALDI-MS. Serum proteins were identified and quantified using the shotgun LC-MS/MS approach. The majority of changes in serum peptidome were detected between pre-treatment samples and samples collected after 3-4 weeks of RT (~25% of registered peptides changed their abundances significantly), yet the intensity of observed changes was not correlated significantly with the degree of acute radiation toxicity or the volume of irradiated tissues. Furthermore, there were a few serum proteins identified, the abundances of which were different in pre-RT and post-RT samples, including immunity and inflammation-related factors. Observed effects were apparently weaker than in comparable groups of head and neck cancer patients in spite of similar radiation doses and volumes of irradiated tissues in both groups. We concluded that changes observed at the level of serum proteome were low for this cohort of prostate cancer patients, although the specific components involved are associated with immunity and inflammation, and reflect the characteristic acute response of the human body to radiation.

  5. Partial-Body Irradiation in Patients with Prostate Cancer Treated with IMRT Has Little Effect on the Composition of Serum Proteome

    Directory of Open Access Journals (Sweden)

    Monika Pietrowska

    2015-06-01

    Full Text Available Partial body irradiation during cancer radiotherapy (RT induces a response of irradiated tissues that could be observed at the level of serum proteome. Here we aimed to characterize the response to RT in group of patients treated because of prostate cancer. Five consecutive blood samples were collected before, during, and after the end of RT in a group of 126 patients who received definitive treatment with a maximum dose of 76 Gy. Serum peptidome, which was profiled in the 2000–16,000 Da range using MALDI-MS. Serum proteins were identified and quantified using the shotgun LC-MS/MS approach. The majority of changes in serum peptidome were detected between pre-treatment samples and samples collected after 3–4 weeks of RT (~25% of registered peptides changed their abundances significantly, yet the intensity of observed changes was not correlated significantly with the degree of acute radiation toxicity or the volume of irradiated tissues. Furthermore, there were a few serum proteins identified, the abundances of which were different in pre-RT and post-RT samples, including immunity and inflammation-related factors. Observed effects were apparently weaker than in comparable groups of head and neck cancer patients in spite of similar radiation doses and volumes of irradiated tissues in both groups. We concluded that changes observed at the level of serum proteome were low for this cohort of prostate cancer patients, although the specific components involved are associated with immunity and inflammation, and reflect the characteristic acute response of the human body to radiation.

  6. Design and Development of transducer for IR radiation measurement

    International Nuclear Information System (INIS)

    Pattarachindanuwong, Surat; Poopat, Bovornchoke; Meethong, Wachira

    2003-06-01

    Recently, IR radiation has many important roles such as for plastics industry, food industry and medical instrumentation. The consequence of exposed irradiation objects from IR can be greatly affected by the quantity of IR radiation. Therefore the objectively this research is to design and develop a transducer for IR radiation measurement. By using a quartz halogen lamp as a IR heat source of IR radiation and a thermopile sensor as a transducer. The thermal conductivity of transducer and air flow, were also considered for design and development of transducer. The study shows that the designed transducer can be used and applied in high temperature process, for example, the quality control of welding, the non-contact temperature measurement of drying oven and the testing of IR source in medical therapy device

  7. Piezoelectric transducer array microspeaker

    KAUST Repository

    Carreno, Armando Arpys Arevalo; Conchouso Gonzalez, David; Castro, David; Kosel, Jü rgen; Foulds, Ian G.

    2016-01-01

    contains 2n piezoelectric transducer membranes, where “n” is the bit number. Every element of the array has a circular shape structure. The membrane is made out four layers: 300nm of platinum for the bottom electrode, 250nm or lead zirconate titanate (PZT

  8. Vibration transducer calibration techniques

    Science.gov (United States)

    Brinkley, D. J.

    1980-09-01

    Techniques for the calibration of vibration transducers used in the Aeronautical Quality Assurance Directorate of the British Ministry of Defence are presented. Following a review of the types of measurements necessary in the calibration of vibration transducers, the performance requirements of vibration transducers, which can be used to measure acceleration, velocity or vibration amplitude, are discussed, with particular attention given to the piezoelectric accelerometer. Techniques for the accurate measurement of sinusoidal vibration amplitude in reference-grade transducers are then considered, including the use of a position sensitive photocell and the use of a Michelson laser interferometer. Means of comparing the output of working-grade accelerometers with that of previously calibrated reference-grade devices are then outlined, with attention given to a method employing a capacitance bridge technique and a method to be used at temperatures between -50 and 200 C. Automatic calibration procedures developed to speed up the calibration process are outlined, and future possible extensions of system software are indicated.

  9. The antioxidant, MnTE-2-PyP, prevents side-effects incurred by prostate cancer irradiation.

    Directory of Open Access Journals (Sweden)

    Rebecca E Oberley-Deegan

    Full Text Available Prostate cancer is the most commonly diagnosed cancer, with an estimated 240,000 new cases reported annually in the United States. Due to early detection and advances in therapies, more than 90% of patients will survive 10 years post diagnosis and treatment. Radiation is a treatment option often used to treat localized disease; however, while radiation is very effective at killing tumor cells, normal tissues are damaged as well. Potential side-effects due to prostate cancer-related radiation therapy include bowel inflammation, erectile dysfunction, urethral stricture, rectal bleeding and incontinence. Currently, radiation therapy for prostate cancer does not include the administration of therapeutic agents to reduce these side effects and protect normal tissues from radiation-induced damage. In the current study, we show that the small molecular weight antioxidant, MnTE-2-PyP, protects normal tissues from radiation-induced damage in the lower abdomen in rats. Specifically, MnTE-2-PyP protected skin, prostate, and testes from radiation-induced damage. MnTE-2-PyP also protected from erectile dysfunction, a persistent problem regardless of the type of radiation techniques used because the penile neurovascular bundles lay in the peripheral zones of the prostate, where most prostate cancers reside. Based on previous studies showing that MnTE-2-PyP, in combination with radiation, further reduces subcutaneous tumor growth, we believe that MnTE-2-PyP represents an excellent radioprotectant in combination radiotherapy for cancer in general and specifically for prostate cancer.

  10. The correlation between the astro consensus panel definition of biochemical failure and clinical outcome for patients with prostate cancer treated with external beam irradiation

    International Nuclear Information System (INIS)

    Horwitz, Eric M.; Vicini, Frank A.; Ziaja, Ellen L.; Dmuchowski, Carl F.; Stromberg, Jannifer S.; Matter, Richard C.; Martinez, Alvaro A.

    1997-01-01

    Purpose: The ASTRO Consensus Panel on PSA After Radiation Therapy recently recommended a definition of biochemical failure (BF) following treatment of prostate cancer with radiation therapy. We reviewed our institution's experience treating patients with external beam irradiation (RT) to determine if the Consensus Panel definition correlates with clinical distant metastases free survival (DMFS), disease free survival (DFS), cause specific survival (CSS), and local control (LC) rates for a large group of patients from the PSA era. Methods And Materials: Between 1/1/87 and 12/31/92, 653 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. Of these patients, 568 had a minimum follow-up of 2 years and constitute the study population. The median pre-treatment PSA and Gleason score was 11 ng/ml and 6, respectively. The median dose to the prostate using megavoltage RT was 66.6 Gy (range: 60-70.4 Gy) using a four field or arc technique. No patient received hormonal therapy either prior to, during, or after radiotherapy unless local or distant failure was documented. Pre-treatment and post-treatment serum PSA levels were recorded. Biochemical failure was defined as three consecutive increases in post-treatment PSA after achieving a nadir. Biochemical failure was recorded as the time midway between the nadir and first increase in PSA. Five year actuarial rates of DMFS, DFS, CSS, and LC were calculated for patients who were biochemically controlled (BC) versus those who failed biochemically. Results: Median follow-up was 56 months (range: 24-118 months). The overall 5 year actuarial rates of DMFS, DFS, CSS, and LC were significantly better in patients who were biochemically controlled versus those who were not (p< 0.001). The median time to DM within the BF group was 21 months (range: 2-112 months). When stratifying by pre-treatment PSA, Gleason score, and T stage, these

  11. Prostate Problems

    Science.gov (United States)

    ... know the exact cause of your prostate problem. Prostatitis The cause of prostatitis depends on whether you ... prostate problem in men older than age 50. Prostatitis If you have a UTI, you may be ...

  12. Nano-optomechanical transducer

    Science.gov (United States)

    Rakich, Peter T; El-Kady, Ihab F; Olsson, Roy H; Su, Mehmet Fatih; Reinke, Charles; Camacho, Ryan; Wang, Zheng; Davids, Paul

    2013-12-03

    A nano-optomechanical transducer provides ultrabroadband coherent optomechanical transduction based on Mach-wave emission that uses enhanced photon-phonon coupling efficiencies by low impedance effective phononic medium, both electrostriction and radiation pressure to boost and tailor optomechanical forces, and highly dispersive electromagnetic modes that amplify both electrostriction and radiation pressure. The optomechanical transducer provides a large operating bandwidth and high efficiency while simultaneously having a small size and minimal power consumption, enabling a host of transformative phonon and signal processing capabilities. These capabilities include optomechanical transduction via pulsed phonon emission and up-conversion, broadband stimulated phonon emission and amplification, picosecond pulsed phonon lasers, broadband phononic modulators, and ultrahigh bandwidth true time delay and signal processing technologies.

  13. Steerable Doppler transducer probes

    International Nuclear Information System (INIS)

    Fidel, H.F.; Greenwood, D.L.

    1986-01-01

    An ultrasonic diagnostic probe is described which is capable of performing ultrasonic imaging and Doppler measurement consisting of: a hollow case having an acoustic window which passes ultrasonic energy and including chamber means for containing fluid located within the hollow case and adjacent to a portion of the acoustic window; imaging transducer means, located in the hollow case and outside the fluid chamber means, and oriented to direct ultrasonic energy through the acoustic window toward an area which is to be imaged; Doppler transducer means, located in the hollow case within the fluid chamber means, and movably oriented to direct Doppler signals through the acoustic window toward the imaged area; means located within the fluid chamber means and externally controlled for controllably moving the Doppler transducer means to select one of a plurality of axes in the imaged area along which the Doppler signals are to be directed; and means, located external to the fluid chamber means and responsive to the means for moving, for providing an indication signal for identifying the selected axis

  14. Dose- and time-dependent gene expression alterations in prostate and colon cancer cells after in vitro exposure to carbon ion and X-irradiation

    Science.gov (United States)

    Suetens, Annelies; Moreels, Marjan; Quintens, Roel; Soors, Els; Buset, Jasmine; Chiriotti, Sabina; Tabury, Kevin; Gregoire, Vincent; Baatout, Sarah

    2015-01-01

    Hadrontherapy is an advanced form of radiotherapy that uses beams of charged particles (such as protons and carbon ions). Compared with conventional radiotherapy, the main advantages of carbon ion therapy are the precise absorbed dose localization, along with an increased relative biological effectiveness (RBE). This high ballistic accuracy of particle beams deposits the maximal dose to the tumor, while damage to the surrounding healthy tissue is limited. Currently, hadrontherapy is being used for the treatment of specific types of cancer. Previous in vitro studies have shown that, under certain circumstances, exposure to charged particles may inhibit cell motility and migration. In the present study, we investigated the expression of four motility-related genes in prostate (PC3) and colon (Caco-2) cancer cell lines after exposure to different radiation types. Cells were irradiated with various absorbed doses (0, 0.5 and 2 Gy) of accelerated 13C-ions at the GANIL facility (Caen, France) or with X-rays. Clonogenic assays were performed to determine the RBE. RT-qPCR analysis showed dose- and time-dependent changes in the expression of CCDC88A, FN1, MYH9 and ROCK1 in both cell lines. However, whereas in PC3 cells the response to carbon ion irradiation was enhanced compared with X-irradiation, the effect was the opposite in Caco-2 cells, indicating cell-type–specific responses to the different radiation types. PMID:25190155

  15. Carcinoma of the prostate treated by pelvic node dissection, iodine-125 seed implant and external irradiation; a study of rectal complications

    Energy Technology Data Exchange (ETDEWEB)

    Abadir, R.; Ross, G. Jr.; Weinstein, S.H. (Missouri Univ., Columbia (USA). Hospital and Clinics)

    1984-09-01

    The University of Missouri-Columbia protocol for localised cancer of the prostate calls for pelvic node dissection, 10 000 cGy at the periphery of the prostate from /sup 125/I and 4000 cGy in 20 fractions to the whole pelvis using supervoltage X-ray therapy. Rectal complications were studied in 104 patients; acute and chronic reactions were defined. During external irradiation 54% did not develop diarrhoea, 43% had mild diarrhoea and 3% had severe diarrhoea. In the chronic stage 77% did not have diarrhoea, 12% had delayed, non-distressing rectal bleeding which did not need specific treatment or needed only simple treatment, 7% had prolonged distressing proctitis and 4% had rectal ulceration or recto-urethral fistula necessitating colostomy. Each of the four patients who had colostomy had an additional aetiological factor (arterial disease, pelvic inflammation, additional radiation, pelvic malignancy or second operation). None of the patients entered in the combined brachytherapy and teletherapy programme, and in whom 0.5 cm space was maintained between the closest seed and the rectal mucosa, developed prolonged proctitis.

  16. The impact of gastrointestinal and genitourinary toxicity on health related quality of life among irradiated prostate cancer patients

    NARCIS (Netherlands)

    Schaake, Wouter; Wiegman, Erwin M.; de Groot, Martijn; van der Laan, Hans Paul; van der Schans, Cees; van den Bergh, Alfons C.M.; Langendijk, Johannes A.

    2013-01-01

    PURPOSE: To determine the impact of late radiation-induced toxicity on health-related quality of life (HRQoL) among patients with prostate cancer. PATIENTS AND METHODS: The study sample was composed of 227 patients, treated with external beam radiotherapy. Common Terminology Criteria for Adverse

  17. The impact of gastrointestinal and genitourinary toxicity on health related quality of life among irradiated prostate cancer patients

    NARCIS (Netherlands)

    Schaake, Wouter; Wiegman, Erwin M; de Groot, Martijn; van der Laan, Hans Paul; van der Schans, Cees P.; van den Bergh, Alfons C M; Langendijk, Johannes A

    PURPOSE: To determine the impact of late radiation-induced toxicity on health-related quality of life (HRQoL) among patients with prostate cancer. PATIENTS AND METHODS: The study sample was composed of 227 patients, treated with external beam radiotherapy. Common Terminology Criteria for Adverse

  18. Nuclear Radiation Tolerance of Single Crystal Aluminum Nitride Ultrasonic Transducer

    Science.gov (United States)

    Reinhard, Brian; Tittmann, Bernhard R.; Suprock, Andrew

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models, (Rempe et al., 2011; Kazys et al., 2005). These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The irradiation is also supported by a multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET ASI) program. The results from this irradiation, which started in February 2014, offer the potential to enable the development of novel radiation tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. Hence, results from this irradiation offer the potential to bridge the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the

  19. Numerical Transducer Modeling

    DEFF Research Database (Denmark)

    Henriquez, Vicente Cutanda

    This thesis describes the development of a numerical model of the propagation of sound waves in fluids with viscous and thermal losses, with application to the simulation of acoustic transducers, in particular condenser microphones for measurement. The theoretical basis is presented, numerical...... manipulations are developed to satisfy the more complicated boundary conditions, and a model of a condenser microphone with a coupled membrane is developed. The model is tested against measurements of ¼ inch condenser microphones and analytical calculations. A detailed discussion of the results is given....

  20. Piezoelectric transducer array microspeaker

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of a piezoelectric micro-speaker. The speaker is an array of micro-machined piezoelectric membranes, fabricated on silicon wafer using advanced micro-machining techniques. Each array contains 2n piezoelectric transducer membranes, where “n” is the bit number. Every element of the array has a circular shape structure. The membrane is made out four layers: 300nm of platinum for the bottom electrode, 250nm or lead zirconate titanate (PZT), a top electrode of 300nm and a structural layer of 50

  1. The correlation between the ASTRO consensus panel definition of biochemical failure and clinical outcome for patients with prostate cancer treated with external beam irradiation

    International Nuclear Information System (INIS)

    Horwitz, Eric M.; Vicini, Frank A.; Ziaja, Ellen L.; Dmuchowski, Carl F.; Stromberg, Jannifer S.; Martinez, Alvaro A.

    1998-01-01

    Purpose: We reviewed our institution's experience treating patients with external beam irradiation (RT) to determine if the ASTRO Consensus Panel definition of biochemical failure (BF) following radiation therapy correlates with clinical distant metastases free survival (DMFS), disease-free survival (DFS), cause-specific survival (CSS), and local control (LC). Methods and Materials: Between 1/1/87 and 12/31/92, 568 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital (median total dose 66.6 Gy; range: 60-70.4 Gy). Biochemical failure was defined as three consecutive increases in post-treatment prostate specific antigen (PSA) after achieving a nadir. Biochemical failure was recorded as the time midway between the nadir and the first rising PSA. Five-year actuarial rates of clinical DMFS, DFS, CSS, and LC were calculated for patients who were biochemically controlled (BC) versus those who failed biochemically. Median follow-up was 56 months (range: 24-118 months). Results: Five-year actuarial rates of DMFS, DFS, CSS, and LC were significantly greater in patients who were biochemically controlled versus those who were not (p < 0.001). In patients who were BC, the 5-year actuarial rates of DMFS, DFS, CSS, and LC were 99%, 99%, 98%, and 99% respectively. For patients who failed biochemically, the 5-year actuarial rates of DMFS, DFS, CSS, and LC were 74%, 64%, 89%, and 86% respectively. When stratifying by pretreatment PSA, Gleason score, and T stage these differences remained significant for DMFS, DFS, and CSS. The Cox proportional hazards model demonstrated that BC was the single most important predictor of clinical outcome for DMFS, DFS, CSS, and LC. Pretreatment PSA and Gleason score were also independent predictors of outcome for DMFS and DFS. Conclusions: The ASTRO Consensus Panel definition of BF following radiation therapy correlates well with clinical DMFS, DFS

  2. Moderate hypofractionated radiotherapy with volumetric modulated arc therapy and simultaneous integrated boost for pelvic irradiation in prostate cancer.

    Science.gov (United States)

    Franzese, C; Fogliata, A; D'Agostino, G R; Di Brina, L; Comito, T; Navarria, P; Cozzi, L; Scorsetti, M

    2017-07-01

    The optimal treatment for unfavourable intermediate/high-risk prostate cancer is still debated. In the present study, the pattern of toxicity and early clinical outcome of patients with localized prostate cancer was analyzed. A cohort of 90 patients treated on pelvic lymph nodes from 2010 to 2015 was selected. All patients were treated with Volumetric Modulated Arc Therapy (VMAT), and Simultaneous integrated boost (SIB) in 28 fractions; the prostate, the seminal vesicle and the pelvic lymph node received total doses of 74.2, 65.5, and 51.8 Gy, respectively. End points were the detection of acute and late toxicities graded according to the Common Toxicity Criteria CTCAE version 3, evaluating the rectal, genito-urinary and gastro-intestinal toxicity. Correlation of OARs dose parameters and related toxicities was explored. Preliminary overall survival and Progression-free survival (PFS) were evaluated. With a median follow-up of 25 months, no interruptions for treatment-related toxicity were recorded. Univariate analysis among dosimetric data and acute toxicities showed no correlations. Regarding late toxicity: the dose received by a rectal volume of 90 cm 3 was found to be significant for toxicity prediction (p = 0.024). PFS was 90.6% and 60.2% at 2 and 4 years, respectively. PFS correlates with age (p = 0.011) and Gleason score (p = 0.011). Stratifying the PSA nadir in quartiles, its value was significant (p = 0.016) in predicting PFS, showing a reduction of PFS of 2 months for each PSA-nadir increase of 0.1 ng/ml. HRT with VMAT and SIB on the whole pelvis in unfavourable prostate cancer patients is effective with a mild pattern of toxicity.

  3. Field displacement during external radiotherapy in prostatic adenocarcinoma treated with radioactive 198Au implants and external irradiation

    International Nuclear Information System (INIS)

    Lennernaes, B.; Letocha, H.; Rikner, G.; Magnusson, A.; Nilsson, S.

    1995-01-01

    The purpose of this work was to study displacement error and internal movements of the prostate during external beam radiotherapy. Verification films in the frontal (n=194) and lateral (n=64) portals were investigated in 14 patients treated with radioactive 198 Au implants. Displacement errors of two implants were investigated. In seven patients, filling of the rectum and the bladder with contrast medium or isotonic saline was performed during CT investigation for planning purposes to detect movements of the prostate. Most (95%) of the displacement errors were less than 10 mm in the frontal portal and less than 15 mm in the lateral portals. No correlation to the patient's weight was found. The displacement errors were randomly distributed. The spatial relations between the implants were not altered during the treatments. Small movements of the prostate were observed. To conclude, the positioning system employed at present (laser) can be sufficient for the margins used (2 cm). In lateral portals, however, the system did not have the ability to detect a possible systematic displacement error from simulator to accelerator. The intention is to decrease the margins to 1 cm, which will necessitate a better positioning system. (orig.)

  4. Chromosome Damage and Cell Proliferation Rates in In Vitro Irradiated Whole Blood as Markers of Late Radiation Toxicity After Radiation Therapy to the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Beaton, Lindsay A., E-mail: Lindsay.Beaton@hc-sc.gc.ca [Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, ON (Canada); Ferrarotto, Catherine; Marro, Leonora [Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, ON (Canada); Samiee, Sara; Malone, Shawn; Grimes, Scott; Malone, Kyle [The Ottawa Hospital, Ottawa Hospital Research Institute, University of Ottawa, 501 Smyth Rd, Ottawa, ON (Canada); Wilkins, Ruth C. [Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, ON (Canada)

    2013-04-01

    Purpose: In vitro irradiated blood samples from prostate cancer patients showing late normal tissue damage were examined for lymphocyte response by measuring chromosomal aberrations and proliferation rate. Methods and Materials: Patients were selected from a randomized trial evaluating the optimal timing of dose-escalated radiation and short-course androgen deprivation therapy. Of 438 patients, 3% experienced grade 3 late radiation proctitis and were considered to be radiosensitive. Blood samples were taken from 10 of these patients along with 20 matched samples from patients with grade 0 proctitis. The samples were irradiated at 6 Gy and, along with control samples, were analyzed for dicentric chromosomes and excess fragments per cell. Cells in first and second metaphase were also enumerated to determine the lymphocyte proliferation rate. Results: At 6 Gy, there were statistically significant differences between the radiosensitive and control cohorts for 3 endpoints: the mean number of dicentric chromosomes per cell (3.26 ± 0.31, 2.91 ± 0.32; P=.0258), the mean number of excess fragments per cell (2.27 ± 0.23, 1.43 ± 0.37; P<.0001), and the proportion of cells in second metaphase (0.27 ± 0.10, 0.46 ± 0.09; P=.0007). Conclusions: These results may be a valuable indicator for identifying radiosensitive patients and for tailoring radiation therapy.

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... ultrasound or with a rectal examination, an ultrasound-guided biopsy can be performed. This procedure involves advancing ... of the Prostate) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related to Ultrasound - Prostate Sponsored ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any treatment ... caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) (Enlargement of the Prostate) Prostate Cancer Ultrasound- and ...

  7. The impact of gastrointestinal and genitourinary toxicity on health related quality of life among irradiated prostate cancer patients

    International Nuclear Information System (INIS)

    Schaake, Wouter; Wiegman, Erwin M.; Groot, Martijn de; Laan, Hans Paul van der; Schans, Cees P. van der; Bergh, Alfons C.M. van den; Langendijk, Johannes A.

    2014-01-01

    Purpose: To determine the impact of late radiation-induced toxicity on health-related quality of life (HRQoL) among patients with prostate cancer. Patients and methods: The study sample was composed of 227 patients, treated with external beam radiotherapy. Common Terminology Criteria for Adverse Events version 3.0 were used to grade late genitourinary and gastrointestinal toxicity. The European Organization for Research and Treatment of Cancer Quality of life Questionnaire C30 (EORTC QLQ-C30) was used to assess HRQoL at baseline, and 6, 12 and 24 months after completion of radiotherapy. Statistical analysis was performed using a multivariate analysis of variance (MANOVA). Results: Urinary incontinence and rectal discomfort significantly affected HRQoL. The impact of urinary incontinence on HRQoL was most pronounced 6 months after radiotherapy and gradually decreased over time. The impact of rectal discomfort on HRQoL was predominant at 6 months after radiotherapy, decreased at 12 months and increased again 2 years after radiotherapy. No significant impact on HRQoL was observed for any of the other toxicity endpoints, or non-toxicity related factors such as hormonal therapy, radiotherapy technique or age. Conclusion: Urinary incontinence and rectal discomfort have a significant impact on HRQoL. Prevention of these side effects may likely improve quality of life of prostate cancer patients after completion of treatment

  8. Circuit for Driving Piezoelectric Transducers

    Science.gov (United States)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  9. Micromachined Integrated Transducers for Ultrasound Imaging

    DEFF Research Database (Denmark)

    la Cour, Mette Funding

    The purpose of this project is to develop capacitive micromachined ultrasonic transducers (CMUTs) for medical imaging. Medical ultrasound transducers used today are fabricated using piezoelectric materials and bulk processing. To fabricate transducers capable of delivering a higher imaging...

  10. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO

    International Nuclear Information System (INIS)

    Santos, Geyza Spigoti

    2011-01-01

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60 Co γ radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 μg/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400μ/ml) in PC3 cells irradiated with 5 Gγ. The survival curves obtained were adequately fitted by a linear-quadratic model, where the α coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 μg/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data obtained in vitro showed a

  11. Hypofractionated intensity modulated irradiation for localized prostate cancer, results from a phase I/II feasibility study

    International Nuclear Information System (INIS)

    Junius, Sara; Haustermans, Karin; Bussels, Barbara; Oyen, Raymond; Vanstraelen, Bianca; Depuydt, Tom; Verstraete, Jan; Joniau, Steven; Van Poppel, Hendrik

    2007-01-01

    To assess acute (primary endpoint) and late toxicity, quality of life (QOL), biochemical or clinical failure (secondary endpoints) of a hypofractionated IMRT schedule for prostate cancer (PC). 38 men with localized PC received 66 Gy (2.64 Gy) to prostate,2 Gy to seminal vesicles (50 Gy total) using IMRT. Acute toxicity was evaluated weekly during radiotherapy (RT), at 1–3 months afterwards using RTOG acute scoring system. Late side effects were scored at 6, 9, 12, 16, 20, 24 and 36 months after RT using RTOG/EORTC criteria. Quality of life was assessed by EORTC-C30 questionnaire and PR25 prostate module. Biochemical failure was defined using ASTRO consensus and nadir+2 definition, clinical failure as local, regional or distant relapse. None experienced grade III-IV toxicity. 10% had no acute genito-urinary (GU) toxicity, 63% grade I; 26% grade II. Maximum acute gastrointestinal (GI) scores 0, I, II were 37%, 47% and 16%. Maximal acute toxicity was reached weeks 4–5 and resolved within 4 weeks after RT in 82%. Grade II rectal bleeding needing coagulation had a peak incidence of 18% at 16 months after RT but is 0% at 24–36 months. One developed a urethral stricture at 2 years (grade II late GU toxicity) successfully dilated until now. QOL urinary symptom scores reached a peak incidence 1 month after RT but normalized 6 months later. Bowel symptom scores before, at 1–6 months showed similar values but rose slowly 2–3 years after RT. Nadir of sexual symptom scores was reached 1–6 months after RT but improved 2–3 years later as well as physical, cognitive and role functional scales. Emotional, social functional scales were lowest before RT when diagnosis was given but improved later. Two years after RT global health status normalized. This hypofractionated IMRT schedule for PC using 25 fractions of 2.64 Gy did not result in severe acute side effects. Until now late urethral, rectal toxicities seemed acceptable as well as failure rates. Detailed analysis of

  12. An enzyme logic bioprotonic transducer

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Takeo; Keene, Scott; Deng, Yingxin; Rolandi, Marco, E-mail: rolandi@uw.edu [Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195-2120 (United States); Josberger, Erik E. [Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195-2120 (United States); Department of Electrical Engineering, University of Washington, Seattle, Washington 98195-2500 (United States)

    2015-01-01

    Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems. We demonstrate the use of a Pd/PdH{sub x} electrode as a bioprotonic transducer that connects H{sup +} currents in solution into an electronic signal. This transducer exploits the reversible formation of PdH{sub x} in solution according to PdH↔Pd + H{sup +} + e{sup −}, and the dependence of this formation on solution pH and applied potential. We integrate the protonic transducer with glucose dehydrogenase as an enzymatic AND gate for glucose and NAD{sup +}. PdH{sub x} formation and associated electronic current monitors the output drop in pH, thus transducing a biological function into a measurable electronic output.

  13. Unique Approaches to Androgen Effects on Prostate Cancer

    National Research Council Canada - National Science Library

    Rosner, W; Kahn, S. M

    2007-01-01

    Sex hormone-binding globulin (SHBG) is a plasma protein that binds andrngens and it acts as a transducer of androgen signaling at the plasma membrane of prostate cancer cells The human prostate cancer cell line LNCaP in addition...

  14. The importance of adequate follow-up in defining treatment success after external beam irradiation for prostate cancer

    International Nuclear Information System (INIS)

    Vicini, Frank A.; Kestin, Larry L.; Martinez, Alvaro A.

    1999-01-01

    Purpose: We reviewed our institution's experience treating patients with localized prostate cancer with external beam radiation therapy (RT) to determine how differences in the length of follow-up affect the determination of treatment outcome using the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus Panel Definition of biochemical failure (BF). Methods and Materials: From January 1987 through December 1997, 1109 patients with localized prostate cancer were treated with definitive external beam RT at William Beaumont Hospital, Royal Oak, Michigan. All patients received external beam RT to a median total prostate dose of 66.6 Gy (range: 59.4-70.4 Gy). A total of 1096 patients (99%) had sufficient prostate-specific antigen (PSA) follow-up to determine their biochemical status. To test the impact of differences in follow-up on the calculation of BF, 389 patients with at least 5 years of PSA follow-up were selected as the reference group for the initial analysis. BF was then retrospectively determined using the Consensus Panel definition at yearly intervals, ignoring the remainder of each patient's follow-up. The median follow-up for this group of patients was 6.6 years (range: 5.0-11.6 years). In a second analysis, patient cohorts were randomly selected with varying median PSA follow-up intervals in order to more accurately represent a population whose follow-up is distributed continuously over a defined range. Seven cohorts were randomly selected with 200 patients in each cohort. Cohorts were individually identified such that half of the patients (100) had 2 years or less follow-up than the stated time point for analysis and half (100) had up to 2 years more follow-up than the time point chosen for analysis. For example, in the cohort with a median follow-up of 3 years, 100 patients with a PSA follow-up from 1 to 3 years were randomly selected, and 100 patients with a follow-up from 3 to 5 years were randomly selected, thus generating a

  15. The Prostate

    Science.gov (United States)

    ... Publications Reports What You Need To Know About™ Prostate Cancer This booklet is about prostate cancer. Learning about medical care for your cancer ... ePub This booklet covers: The anatomy of the prostate and basics about prostate cancer Treatments for prostate ...

  16. Margin to CTV in simultaneous irradiation of treatment volumes attache to various anatomical frameworks: The paradigm of the CA. Of prostate in high risk with indication of lymph node irradiation; Margen al CTV en irradiacion simultanea de volumenes de tratamiento adscritos a distintos marcos anatomicos: El paradigma del CA. de prostata de alto riesgo con indicacion de irradiacion ganglionar

    Energy Technology Data Exchange (ETDEWEB)

    Sanz Freire, C. J.; Perez Echaguen, S.; Collado chamorro, P.; Diaz Pascual, V.; Vazquez Galinanes, A.; Ossola Lentati, G. A.

    2013-07-01

    The triple objective of this work is: 1 check the effect on the positioning of the GGPP of corrections on the position of the prostate in simultaneous irradiation guided through daily image and its relationship with the filling of rectum and bladder 2. check if employees standard margins for CTV GGPP are valid for this technique 3 calculate the necessary extension of the margin to 2. is not verified. (Author)

  17. Characterization of Dielectric Electroactive Polymer transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Møller, Martin B.; Sarban, Rahimullah

    2014-01-01

    This paper analysis the small-signal model of the Dielectric Electro Active Polymer (DEAP) transducer. The DEAP transducer have been proposed as an alternative to the electrodynamic transducer in sound reproduction systems. In order to understand how the DEAP transducer works, and provide...

  18. Prostate Diseases

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Prostate Diseases Font size A A A Print Share Glossary Basic ... body. Approximately 3 million American men have some type of prostate disease. The most common prostate diseases ...

  19. Prostate brachytherapy

    Science.gov (United States)

    Implant therapy - prostate cancer; Radioactive seed placement; Internal radiation therapy - prostate; High dose radiation (HDR) ... place the seeds that deliver radiation into your prostate. The seeds are placed with needles or special ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to ... Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces pictures ...

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  2. Scrutiny of the ASTRO consensus definition of biochemical failure in irradiated prostate cancer patients demonstrates its usefulness and robustness

    International Nuclear Information System (INIS)

    Hanlon, Alexandra L.; Hanks, Gerald E.

    2000-01-01

    Purpose: The goals of this study are: (1) to establish the robustness of the Fox Chase Cancer Center (FCCC) and the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definitions of failure by comparing biochemical estimates under various modifications of the censoring and failure time components to their respective unaltered definitions; (2) to isolate the source of variation between the two definitions of failure; and (3) to describe the hazard of failure over time for each definition. Methods: Between May 1989 and May 1997, 670 men were treated at Fox Chase Cancer Center for localized prostate cancer using three-dimensional conformal radiation therapy (3DCRT). These men were stratified into three groups for analysis: 111 men treated with adjuvant hormones; 204 men treated with radiation therapy alone and presenting with more favorable prognosis tumor characteristics; 255 men treated with radiation therapy alone and presenting with less favorable prognosis tumor characteristics. For each group, biochemical failure was estimated and compared using the FCCC and ASTRO definitions of failure. The robustness of each definition was evaluated by comparing estimates under the definition as stated to those under various modifications of the censoring and failure components. Analyses were also performed while excluding slow-progressing patients. To isolate the source of variation between the two failure definitions, estimates were compared for patients with agreement in failure status. Estimates of biochemical failure, and thus hazard rates, were made using Kaplan-Meier methodology. Results: ASTRO biochemical failure estimates were higher than the FCCC failure estimates in the first 5 years post-treatment. Beyond 5 years, ASTRO estimates level off, while the FCCC failure estimates continued to increase. These failure patterns were similar in all patient groups; however, patients treated with adjuvant hormones had a much higher risk of failure

  3. Dose-volume effects for pelvic bone marrow in predicting hematological toxicity in prostate cancer radiotherapy with pelvic node irradiation.

    Science.gov (United States)

    Sini, Carla; Fiorino, Claudio; Perna, Lucia; Noris Chiorda, Barbara; Deantoni, Chiara Lucrezia; Bianchi, Marco; Sacco, Vincenzo; Briganti, Alberto; Montorsi, Francesco; Calandrino, Riccardo; Di Muzio, Nadia; Cozzarini, Cesare

    2016-01-01

    To prospectively identify clinical/dosimetric predictors of acute/late hematologic toxicity (HT) in chemo-naÏve patients treated with whole-pelvis radiotherapy (WPRT) for prostate cancer. Data of 121 patients treated with adjuvant/salvage WPRT were analyzed (static-field IMRT n=19; VMAT/Rapidarc n=57; Tomotherapy n=45). Pelvic bone marrow (BM) was delineated as ilium (IL), lumbosacral, lower and whole pelvis (WP), and the relative DVHs were calculated. HT was graded both according to CTCAE v4.03 and as variation in percentage relative to baseline. Logistic regression was used to analyze association between HT and clinical/DVHs factors. Significant differences (p<0.005) in the DVH of BM volumes between different techniques were found: Tomotherapy was associated with larger volumes receiving low doses (3-20 Gy) and smaller receiving 40-50 Gy. Lower baseline absolute values of WBC, neutrophils and lymphocytes (ALC) predicted acute/late HT (p ⩽ 0.001). Higher BM V40 was associated with higher risk of acute Grade3 (OR=1.018) or late Grade2 lymphopenia (OR=1.005). Two models predicting lymphopenia were developed, both including baseline ALC, and BM WP-V40 (AUC=0.73) and IL-V40+smoking (AUC=0.904) for acute/late respectively. Specific regions of pelvic BM predicting acute/late lymphopenia, a risk factor for viral infections, were identified. The 2-variable models including specific constraints to BM may help reduce HT. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Auto-positioning ultrasonic transducer system

    Science.gov (United States)

    Buchanan, Randy K. (Inventor)

    2010-01-01

    An ultrasonic transducer apparatus and process for determining the optimal transducer position for flow measurement along a conduit outer surface. The apparatus includes a transmitting transducer for transmitting an ultrasonic signal, said transducer affixed to a conduit outer surface; a guide rail attached to a receiving transducer for guiding movement of a receiving transducer along the conduit outer surface, wherein the receiving transducer receives an ultrasonic signal from the transmitting transducer and sends a signal to a data acquisition system; and a motor for moving the receiving transducer along the guide rail, wherein the motor is controlled by a controller. The method includes affixing a transmitting transducer to an outer surface of a conduit; moving a receiving transducer on the conduit outer surface, wherein the receiving transducer is moved along a guide rail by a motor; transmitting an ultrasonic signal from the transmitting transducer that is received by the receiving transducer; communicating the signal received by the receiving transducer to a data acquisition and control system; and repeating the moving, transmitting, and communicating along a length of the conduit.

  5. Re-analysis of clinical and treatment related prognostic factors on outcome using biochemical control as an end-point in patients with prostate cancer treated with external beam irradiation

    International Nuclear Information System (INIS)

    Ziaja, Ellen L.; Horwitz, Eric M.; Vicini, Frank A.; Dmuchowski, Carl F.; Brabbins, Donald S.; Gustafson, Gary S.; Hollander, Jay; Matter, Richard C.; Stromberg, Jannifer S.; Martinez, Alvaro A.

    1996-01-01

    Purpose: Prostate specific antigen (PSA) has been established as the most important prognostic factor for prostate cancer. We reviewed our experience treating patients with clinically localized prostate cancer with external beam irradiation (RT) to evaluate if previously defined clinical and treatment related prognostic factors remain valid when biochemical control was used as an end-point to evaluate results. Methods and Materials: Between 1/87 and 12/91, 480 patients with clinically localized prostate cancer received external beam irradiation (RT) using localized prostate fields at William Beaumont Hospital. The median dose to the prostate was 66.6 Gy (range 58 - 70.4 Gy) using a 4 field or arc technique. Pre- and post-treatment serum PSA levels were recorded. Biochemical control was defined as PSA nadir ≤ 1.5 ng/ml within 1 year of treatment completion. After achieving nadir, if 2 consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase. Patients (pts) were divided into 3 groups according to total number of days on treatment: ≤ 49 days (≤ 7 weeks)- 21 pts; 50-63 days (8-9 weeks)- 429 pts; and ≥ 64 days (≥ 9 weeks)- 15 pts. Patients were also divided into groups with respect to the method of diagnosis: TURP (81 pts), or other means (399 pts). Patients were further divided into 2 groups: 1) if they had ever had a pre-treatment TURP (170 pts) or 2) if they had not (310 pts). Patients were divided into 2 groups according to boost technique: bilateral arcs (459 pts) or 4 field box (21 pts). Patients were also divided into groups according to total RT dose: ≤ 70 Gy (421 pts) or > 70 Gy (59 pts). Patients were further subdivided into 3 dose groups: 70 Gy (59 pts). Results: Median follow-up is 48 months (range 3 - 112 months). No statistically significant difference in rates of biochemical control were noted for treatment time, overall time (date of biopsy to completion of RT), or treatment time divided into

  6. Imaging and prostate cancer

    International Nuclear Information System (INIS)

    Schwartz, Lawrence H.

    1996-01-01

    The use of imaging in evaluating patients with prostate cancer is highly dependent upon the purpose of the evaluation. Ultrasound, Computed Tomography, Magnetic Resonance Imaging, TC-99m Bone Scanning, and Positron Emission Tomography may all be utilized for imaging in prostate cancer. The utility of each of these modalities depends upon the intended purpose: for instance, screening, staging, or evaluating for progression of disease in patients with prostate cancer. Transrectal ultrasound is performed by placing a 5MHz to 7.5 MHz transducer in the rectum and imaging the prostate in the coronal and sagittal planes. Prostate cancer generally appears as an area of diminished echogenocity in the peripheral zone of the prostate gland. However, up to 24% of prostate cancers are isoechoic and cannot be well distinguished from the remainder of the peripheral zone. In addition, the incidence of malignancy in a lesion judged to be suspicious on ultrasound is between 20% and 25%. Therefore, while ultrasound is the least expensive of the three cross sectional imaging modalities, its relatively low specificity precludes it from being used as a screening examination. Investigators have also looked at the ability of ultrasound to evaluate the presence and extent of extracapsular spread of prostate cancer. The RDOG (Radiology Diagnostic Oncology Group) multi-institutional cooperative trial reported a disappointing overall accuracy of ultrasound of 58% for staging prostate cancer. The accuracy was somewhat higher 63%, for patients with advanced disease. The other cross-sectional imaging modalities available for imaging the prostate include Computed Tomography and Magnetic Resonance Imaging. Computed Tomography is useful as an 'anatomic' imaging technique to detect lymph node enlargement. It is not sensitive in detecting microscopic nodal involvement with tumor, or tumor in non-enlarged pelvic lymph nodes. The primary prostate neoplasm is generally the same attenuation as the normal

  7. HDR monotherapy for prostate cancer: A simulation study to determine the effect of catheter displacement on target coverage and normal tissue irradiation

    International Nuclear Information System (INIS)

    Kolkman-Deurloo, Inger-Karine K.; Roos, Martin A.; Aluwini, Shafak

    2011-01-01

    Purpose: The aim of this study was to systematically analyse the effect of catheter displacements both on target coverage and normal tissue irradiation in fractionated high dose rate (HDR) prostate brachytherapy, using a simulation study, and to define tolerances for catheter displacement ensuring that both target coverage and normal tissue doses remain clinically acceptable. Besides the effect of total implant displacement, also displacements of catheters belonging to selected template rows only were evaluated in terms of target coverage and normal tissue dose, in order to analyse the change in dose distribution as a function of catheter dwell weight and catheter location. Material and methods: Five representative implant geometries, with 17 catheters each, were selected. The clinical treatment plan was compared to treatment plans in which an entire implant displacement in caudal direction over 3, 5, 7 and 10 mm was simulated. Besides, treatment plans were simulated considering a displacement of either the central, most ventral or most dorsal catheter rows only, over 5 mm caudally. Results: Due to displacement of the entire implant the target coverage drops below the tolerance of 93% for all displacements studied. The effect of displacement of the entire implant on organs at risk strongly depended on the patient anatomy; e.g., for 80% of the implant geometries the V 80 of the rectum exceeded its tolerance for all displacements. The effect of displacement of catheters belonging to selected template rows depended strongly on the relative weight of each catheter row when considering the target coverage and on its location when considering the dose in the organs at risk. Conclusion: This study supports the need for a check of the catheter locations before each fraction and correction of deviations of the catheter position exceeding 3 mm.

  8. Model of a Piezoelectric Transducer

    Science.gov (United States)

    Goodenow, Debra

    2004-01-01

    It's difficult to control liquid and gas in propellant tanks in zero gravity. A possible a design would utilize acoustic liquid manipulation (ALM) technology which uses ultrasonic beams conducted through a liquid and solid media, to push gas bubbles in the liquid to desirable locations. We can propel and control the bubble with acoustic radiation pressure by aiming the acoustic waves on the bubble s surface. This allows us to design a so called smart tank in which the ALM devices transfer the gas to the outer wall of the tank and isolating the liquid in the center. Because the heat transfer rate of a gas is lower of that of the liquid it would substantially decrease boil off and provide of for a longer storage life. The ALM beam is composed of little wavelets which are individual waves that constructively interfere with each other to produce a single, combined acoustic wave front. This is accomplished by using a set of synchronized ultrasound transducers arranged in an array. A slight phase offset of these elements allows us to focus and steer the beam. The device that we are using to produce the acoustic beam is called the piezoelectric transducer. This device converts electrical energy to mechanical energy, which appears in the form of acoustic energy. Therefore the behavior of the device is dependent on both the mechanical characteristics, such as its density, cross-sectional area, and its electrical characteristics, such as, electric flux permittivity and coupling factor. These devices can also be set up in a number of modes which are determined by the way the piezoelectric device is arranged, and the shape of the transducer. For this application we are using the longitudinal or thickness mode for our operation. The transducer also vibrates in the lateral mode, and one of the goals of my project is to decrease the amount of energy lost to the lateral mode. To model the behavior of the transducers I will be using Pspice, electric circuit modeling tool, to

  9. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Brian; Tittmann, Bernhard [The Pennsylvania State University (United States); Rempe, Joy; Daw, Joshua [Idaho National Laboratory (United States); Kohse, Gordon; Carpenter, David; Ames, Michael; Ostrovsky, Yakov [Massachusetts Institute of Technology (United States); Ramuhalli, Pradeep; Montgomery, Robert [Pacific Northwest National Laboratory (United States); Chien, Hualte [Argonne National Laboratory (United States); Wernsman, Bernard [Bechtel Marine Propulsion Corp (United States)

    2015-03-31

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) produce harsh environments in and near the reactor core that can severely tax material performance and limit component operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration irradiation performance of fuel and structural materials used in existing and new reactors. In order to maximize the amount of information obtained from Material Testing Reactor (MTR) irradiations, DOE is also funding development of enhanced instrumentation that will be able to obtain in-situ, real-time data on key material characteristics and properties, with unprecedented accuracy and resolution. Such data are required to validate new multi-scale, multi-physics modeling tools under development as part of a science-based, engineering driven approach to reactor development. It is not feasible to obtain high resolution/microscale data with the current state of instrumentation technology. However, ultrasound-based sensors offer the ability to obtain such data if it is demonstrated that these sensors and their associated transducers are resistant to high neutron flux, high gamma radiation, and high temperature. To address this need, the Advanced Test Reactor National Scientific User Facility (ATR-NSUF) is funding an irradiation, led by PSU, at the Massachusetts Institute of Technology Research Reactor to test the survivability of ultrasound transducers. As part of this effort, PSU and collaborators have designed, fabricated, and provided piezoelectric and magnetostrictive transducers that are optimized to perform in harsh, high flux, environments. Four piezoelectric transducers were fabricated with either aluminum nitride, zinc oxide, or bismuth titanate as the active element that were coupled to either Kovar or aluminum waveguides and two

  10. Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers

    Science.gov (United States)

    Reinhardt, Brian; Tittmann, Bernhard; Rempe, Joy; Daw, Joshua; Kohse, Gordon; Carpenter, David; Ames, Michael; Ostrovsky, Yakov; Ramuhalli, Pradeep; Montgomery, Robert; Chien, Hualte; Wernsman, Bernard

    2015-03-01

    Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) produce harsh environments in and near the reactor core that can severely tax material performance and limit component operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration irradiation performance of fuel and structural materials used in existing and new reactors. In order to maximize the amount of information obtained from Material Testing Reactor (MTR) irradiations, DOE is also funding development of enhanced instrumentation that will be able to obtain in-situ, real-time data on key material characteristics and properties, with unprecedented accuracy and resolution. Such data are required to validate new multi-scale, multi-physics modeling tools under development as part of a science-based, engineering driven approach to reactor development. It is not feasible to obtain high resolution/microscale data with the current state of instrumentation technology. However, ultrasound-based sensors offer the ability to obtain such data if it is demonstrated that these sensors and their associated transducers are resistant to high neutron flux, high gamma radiation, and high temperature. To address this need, the Advanced Test Reactor National Scientific User Facility (ATR-NSUF) is funding an irradiation, led by PSU, at the Massachusetts Institute of Technology Research Reactor to test the survivability of ultrasound transducers. As part of this effort, PSU and collaborators have designed, fabricated, and provided piezoelectric and magnetostrictive transducers that are optimized to perform in harsh, high flux, environments. Four piezoelectric transducers were fabricated with either aluminum nitride, zinc oxide, or bismuth titanate as the active element that were coupled to either Kovar or aluminum waveguides and two

  11. DEVELOPMENTAL STUDIES OF NUCLEAR DIGITAL TRANSDUCERS

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, James L.

    1963-09-15

    A pressure transducer based on mechanical modulation of a beam of alpha particles is described. This type of transducer is capable of direct digital pressure measurexnent with corresponding telemetry advantages. Any variable that is sensed through a mechanical displacement is measurable by means of a corresponding member of this transducer family. Preliminary tests of an experimental pressure transducer show an overall accuracy within a few tenths of one percent, with promise of substantial improvement. General characteristics of nuclear digital transducers include exceptional long-term calibration stability and accuracy, independent of ambient environmental effects. Three concepts of systems enipioying these transducers are discussed. (auth)

  12. Acoustic Levitation With One Transducer

    Science.gov (United States)

    Barmatz, Martin B.

    1987-01-01

    Higher resonator modes enables simplification of equipment. Experimental acoustic levitator for high-temperature containerless processing has round cylindrical levitation chamber and only one acoustic transducer. Stable levitation of solid particle or liquid drop achieved by exciting sound in chamber to higher-order resonant mode that makes potential well for levitated particle or drop at some point within chamber.

  13. Proceedings of transducer 84 conference

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    In the broad and varied field of sensors this conference reviews thermal sensors for temperature measurements, gas sensors for gas analysis (for example analysis of exhaust gases from vehicles), optical fiber sensors, applications for optics, mechanics, robotics and signal processing. In particular one of the applications concerns acoustical transducers operating in liquid sodium for LMFBR reactors.

  14. Calculations for Piezoelectric Ultrasonic Transducers

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1986-01-01

    Analysis of piezoelectric ultrasonic transducers implies a solution of a boundary value problem, for a boay which consists of different materials, including a piezoelectric part. The problem is dynamic at frequencies, where a typical wavelength is somewhat less than the size of the body. Radiation...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on ... to do the scanning. The transducer is a small hand-held device that resembles a microphone, attached ...

  16. About the Prostate

    Science.gov (United States)

    ... PCF: Many vs Cancer Contact Us About the Prostate Prostate Cancer Basics Risk Factors Prostate Cancer Prevention ... that connects to the anus. Ultrasound of the prostate Prostate Zones The prostate is divided into several ...

  17. The research on high power transducer

    International Nuclear Information System (INIS)

    Zhao Wuling; Li Yubin; Peng Shuwen

    2014-01-01

    This paper introduces the transducer structure used double PWM mode, the control system design of hardware and software. The transducer has been applied in factory. From the real experiment, it shows that the system has a high reliability. (authors)

  18. A Direct Driver for Electrostatic Transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes a power stage suitable for driving an electrostatic transducer under biasing. Measurement results of a ±400 V prototype amplifier are shown. THD below 1% is reported....

  19. Osteogenic sarcoma of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Tsutomu; Terunuma, Masahiro [Koseiren Nagaoka Chuo General Hospital, Niigata (Japan); Ikarashi, Toshihiko; Ishizaki, Satoshi

    2001-04-01

    A 76-year-old man was treated with bilateral orchiectomy, estramustine phosphate and pelvic irradiation for prostate cancer. Osteogenic sarcoma of the prostate developed 18 months after the treatment. Postmortem examination revealed that the tumor was 8 cm in diameter and had infiltrated into the bladder and rectal walls and had resulted in peritoneal dissemination. There was no distant metastasis. Macroscopically, the tumor was ashen, firm and relatively homogenous and diffusely spread. Histologically, it was composed of spindle and pleomorphic cells, which were making osteoid with calcification. There was no ordinary tubular formation as shown in adenocarcinoma of the prostate. No positive immunostaining for prostate-specific antigen, epithelial membrane antigen and cytokeratin (AE-1, AE-3) were confirmed. Positive immunostaining for nonepithelial marker vimentin was confirmed. The ultimate diagnosis was osteogenic sarcoma of the prostate. (author)

  20. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  1. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo; Castro, David; Conchouso Gonzalez, David; Kosel, Jü rgen; Foulds, Ian G.

    2016-01-01

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  2. Calculations for piezoelectric ultrasonic transducers

    International Nuclear Information System (INIS)

    Jensen, H.

    1986-05-01

    Analysis of piezoelectric ultrasonic transducers implies a solution of a boundary value problem, for a body which consists of different materials, including a piezoelectric part. The problem is dynamic at frequencies, where a typical wavelength is somewhat less than the size of the body. Radiation losses as well as internal losses may be important. Due to the complexity of the problem, a closed form solution is the exception rather than the rule. For this reason, it is necessary to use approximate methods for the analysis. Equivalent circuits, the Rayleigh-Ritz method, Mindlin plate theory and in particular the finite element method are considered. The finite element method is utilized for analysis of axisymmetric transducers. An explicit, fully piezoelectric, triangular ring element, with linear variations in displacement and electric potential is given. The influence of a fluid half-space is also given, in the form of a complex stiffness matrix. A special stacking procedure, for analysis of the backing has been developed. This procedure gives a saving, which is similar to that of the fast fourier transform algorithm, and is also wellsuited for analysis of finite and infinite waveguides. Results obtained by the finite element method are shown and compared with measurements and exact solutions. Good agreement is obtained. It is concluded that the finite element method can be a valueable tool in analysis and design of ultrasonic transducers. (author)

  3. Transducers

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B

    stream_size 27 stream_content_type text/plain stream_name Encycl_Microcomputers_18_335.pdf.txt stream_source_info Encycl_Microcomputers_18_335.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  4. Prostatitis - nonbacterial

    Science.gov (United States)

    NBP; Prostatodynia; Pelvic pain syndrome; CPPS; Chronic nonbacterial prostatitis; Chronic genitourinary pain ... Possible causes of nonbacterial prostatitis include: A past ... common types of bacteria Irritation caused by a backup of urine ...

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... a physician during a routine physical exam or prostate cancer screening exam. an elevated blood test result. difficulty ... Information and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top of page This page was reviewed on ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... pictures of a man’s prostate gland and to help diagnose symptoms such as difficulty urinating or an ... Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, ...

  7. Prostate Cancer

    Science.gov (United States)

    ... man's bladder that produces fluid for semen. Prostate cancer is common among older men. It is rare ... younger than 40. Risk factors for developing prostate cancer include being over 65 years of age, family ...

  8. Prostate Cancer

    Science.gov (United States)

    ... breast cancer (BRCA1 or BRCA2) or a very strong family history of breast cancer, your risk of prostate cancer may be higher. Obesity. Obese men diagnosed with prostate cancer may be more likely ...

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top of page ... to Ultrasound - Prostate Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... about radiology? Share your patient story here Images × Image Gallery Radiologist and patient consultation. View full size with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) (Enlargement of the Prostate) ...

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... uses sound waves to produce pictures of a man’s prostate gland and to help diagnose symptoms such ... also called transrectal ultrasound, provides images of a man's prostate gland and surrounding tissue. The exam typically ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... is used to guide the biopsy to specific regions of the prostate gland. When the examination is ... is relatively insensitive to the pain in the region of the prostate. A biopsy will add time ...

  13. An analysis of clinical and treatment related prognostic factors on outcome using biochemical control as an end-point in patients with prostate cancer treated with external beam irradiation

    International Nuclear Information System (INIS)

    Horwitz, Eric M.; Vicini, Frank A.; Ziaja, Ellen L.; Dmuchowski, Carl F.; Stromberg, Jannifer S.; Gustafson, Gary S.; Martinez, Alvaro A.

    1997-01-01

    Purpose: We reviewed our institution's experience in treating patients with clinically localized prostate cancer with external beam irradiation (RT) to determine if previously analyzed clinical and treatment related prognostic factors affected outcome when biochemical control was used as an end-point to evaluate results. Materials and methods: Between 1 January 1987 and 31 December 1991, 470 patients with clinically localized prostate cancer were treated with external beam RT using localized prostate fields at William Beaumont Hospital. Biochemical control was defined as PSA nadir ≤1.5 ng/ml within 1 year of treatment. After achieving nadir, if two consecutive increases of PSA were noted, the patient was scored a failure at the time of the first increase. Prognostic factors, including the total number of days in treatment, the method of diagnosis, a history of any pretreatment transurethral resection of the prostate (TURP) and the type of boost were analyzed. Results: Median follow-up was 48 months. No statistically significant difference in rates of biochemical control were noted for treatment time, overall time (date of biopsy to completion of RT), history of any pretreatment TURP, history of diagnosis by TURP, or boost techniques. Patients diagnosed by TURP had a significant improvement in the overall rate of biochemical control (P < 0.03) compared to transrectal/transperineal biopsy. The 5-year actuarial rates were 58 versus 39%, respectively. This improvement was not evident when pretreatment PSA, T stage, or Gleason score were controlled for. On multivariate analysis, no variable was associated with outcome. When analysis was limited to a more favorable group of patients (T1/T2 tumors, pretreatment PSA ≤20 ng/ml and Gleason score <7), none of these variables were significantly predictive of biochemical control when controlling for pretreatment PSA, T stage and Gleason score. Conclusions: No significant effect of treatment time, overall time, pretreatment

  14. Bacterial prostatitis.

    Science.gov (United States)

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of the prostate gland is typically used to help diagnose symptoms such as: a nodule felt by a physician during a routine physical exam or prostate cancer screening exam. an elevated ...

  16. Prostate Diseases

    Science.gov (United States)

    The prostate is a gland in men. It helps make semen, the fluid that contains sperm. The prostate surrounds the tube that carries urine away from ... and out of the body. A young man's prostate is about the size of a walnut. It ...

  17. In vivo studies on the efficiency of irradiation with carbon ions at the syngeneic prostate carcinoma model R3327; In vivo Untersuchungen zur Wirksamkeit von Bestrahlungen mit Kohlenstoffionen am syngenen Prostatakarzinom Modell R3327

    Energy Technology Data Exchange (ETDEWEB)

    Glowa, Christin

    2013-07-01

    The aim of this study is to characterize differential effects after carbon ion ({sup 12}C) relative to photon irradiations in vivo in three different sublines of the syngeneic rat prostate adenocarcinoma (PCa) R3327 (AT1, HI, and H) as well as to identify tumor specific influence factors of the radiation response. Subcutaneous PCa tumor fragments in rats were irradiated with single (1 Fx) or split (2 Fx) doses of photons or carbon ions (75 keV/μ), respectively. Primary endpoint was local tumor control after 300 days. Based on dose-response curves, the TCD{sub 50{sup -}} values (dose at 50% tumor control probability) were used to calculate the relative biological effectiveness (RBE) of carbon ions. Additionally, potential carbon ion specific irradiation effects were studied. For this, in vivo tumor-physiological changes, structural and functional radiation- induced effects of gene expression as well as tumor subpopulations with tumor-inducing properties were investigated. For {sup 12}C- irradiations with 1 Fx or 2 Fx, the RBEs were 1.62 (H), 2.08 (HI) and 2.3 (AT1) and 1.9 (H), 2.1 (HI) and 2.67 (AT1), respectively. Isoeffective irradiation with photons and {sup 12}C- ions showed different kinetics of the radiation response. Magnetic resonance imaging (MRI) and histology showed a faster and stronger increase of tumor vessel permeability after {sup 12}C- irradiation compared to photons. After irradiation, DNA-repair mechanisms, immune system components and migration were induced, in contrast cell cycle progression, adhesion, angiogenesis, and the aerobic metabolism were downregulated. Especially, the kinetics of signaling cascades, apoptosis and stress-response were dependent on irradiation modality. In HI- and H-tumors CD24{sup +}/CD45{sup -} cells were identified as tumor inducing cells (TICs) in vivo. All three sublines were established under cell culture conditions to enable further molecular biological analyses. In conclusion, {sup 12}C- irradiation is

  18. Radiation-resistant pressure transducers

    International Nuclear Information System (INIS)

    Abbasov, Sh.M.; Kerimova, T.I.

    2005-01-01

    Full text : The sensitive element of vibrofrequency tensor converter (VTC) is an electromechanical resonator of string type with electrostatic excitation of longitudinal mechanical vibrations. The string is made from tensosensitive thread-like monocrystal n-Ge1-x Six (length 1-5 mm, diameter 8-12 mcm) with current outlet and strictly fixed by ends at plate or deformable surface (in elastic element) at 50 mcm apartheid. With increasing Si atomic percent in n-Ge1-x Six the converter tens sensitivity increases. There has been shown the scheme of pressure transducer which contains monocrystalline silicon membrane and string tens converter from thread-like monocrystal Ge-Si. Using method, when crystal position on membrane while it deforms by pressure, corresponds to free (uptight) state, allowed to obtain the maximum sensitivity in measurement of pressure fluctuation. The transducers of absolute and pressure differential of this type can be used in automated systems of life activity. The high sensitivity of string transducers to pressure exceeding 100 hertz/mm (water column) permits to use them in devices for measuring gas concentration. The combination of optical and deformation methods of measurements forms the basis of their operation. The pressure change occurs due to the fact that gas molecules absorbing the quanta of incident light, become at excited state and then excitation energy of their vibrational-rotatory degrees of freedom converts to the energy of translational motion of molecules, i.e. to heat appropriate to pressure increase. Using these tens converters of high pressure one can prevent the possible accidents on oil pipe-like Baku-Tibilisi-Ceyhan

  19. Micromachined capacitive ultrasonic immersion transducer array

    Science.gov (United States)

    Jin, Xuecheng

    Capacitive micromachined ultrasonic transducers (cMUTs) have emerged as an attractive alternative to conventional piezoelectric ultrasonic transducers. They offer performance advantages of wide bandwidth and sensitivity that have heretofore been attainable. In addition, micromachining technology, which has benefited from the fast-growing microelectronics industry, enables cMUT array fabrication and electronics integration. This thesis describes the design and fabrication of micromachined capacitive ultrasonic immersion transducer arrays. The basic transducer electrical equivalent circuit is derived from Mason's theory. The effects of Lamb waves and Stoneley waves on cross coupling and acoustic losses are discussed. Electrical parasitics such as series resistance and shunt capacitance are also included in the model of the transducer. Transducer fabrication technology is systematically studied. Device dimension control in both vertical and horizontal directions, process alternatives and variations in membrane formation, via etch and cavity sealing, and metalization as well as their impact on transducer performance are summarized. Both 64 and 128 element 1-D array transducers are fabricated. Transducers are characterized in terms of electrical input impedance, bandwidth, sensitivity, dynamic range, impulse response and angular response, and their performance is compared with theoretical simulation. Various schemes for cross coupling reduction is analyzed, implemented, and verified with both experiments and theory. Preliminary results of immersion imaging are presented using 64 elements 1-D array transducers for active source imaging.

  20. LAVA Pressure Transducer Trade Study

    Science.gov (United States)

    Oltman, Samuel B.

    2016-01-01

    The Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) payload will transport the (LAVA) subsystem to hydrogen-rich locations on the moon supporting NASA's in-situ resource utilization (ISRU) programs. There, the LAVA subsystem will analyze volatiles that evolve from heated regolith samples in order to quantify how much water is present. To do this, the system needs resilient pressure transducers (PTs) to calculate the moles in the gas samples. The PT trade study includes a comparison of newly-procured models to a baseline unit with prior flight history in order to determine the PT model with the best survivability in flight-forward conditions.

  1. Energetic balance in an ultrasonic reactor using focused or flat high frequency transducers.

    Science.gov (United States)

    Hallez, L; Touyeras, F; Hihn, J Y; Klima, J

    2007-09-01

    In order to undertake irradiation of polymer blocks or films by ultrasound, this paper deals with the measurements of ultrasonic power and its distribution within the cell by several methods. The electric power measured at the transducer input is compared to the ultrasonic power input to the cell evaluated by calorimetry and radiation force measurement for different generator settings. Results obtained in the specific case of new transducer types (composites and focused composites i.e., HIFU: high intensity focused ultrasound) provide an opportunity to conduct a discussion about measurement methods. It has thus been confirmed that these measurement techniques can be applied to HIFU transducers. For all cases, results underlined the fact that measurement of radiation pressure for power evaluation is more adapted to low powers (generator-transducer-liquid and sample.

  2. Stages of Prostate Cancer

    Science.gov (United States)

    ... Genetics of Prostate Cancer Prostate Cancer Screening Research Prostate Cancer Treatment (PDQ®)–Patient Version General Information About Prostate Cancer Go to Health Professional Version Key Points Prostate ...

  3. Micromachined Ultrasonic Transducers for 3-D Imaging

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann

    of state-of-the-art 3-D ultrasound systems. The focus is on row-column addressed transducer arrays. This previously sparsely investigated addressing scheme offers a highly reduced number of transducer elements, resulting in reduced transducer manufacturing costs and data processing. To produce...... such transducer arrays, capacitive micromachined ultrasonic transducer (CMUT) technology is chosen for this project. Properties such as high bandwidth and high design flexibility makes this an attractive transducer technology, which is under continuous development in the research community. A theoretical...... treatment of CMUTs is presented, including investigations of the anisotropic plate behaviour and modal radiation patterns of such devices. Several new CMUT fabrication approaches are developed and investigated in terms of oxide quality and surface protrusions, culminating in a simple four-mask process...

  4. The Dynamic Performance of Flexural Ultrasonic Transducers

    Directory of Open Access Journals (Sweden)

    Andrew Feeney

    2018-01-01

    Full Text Available Flexural ultrasonic transducers are principally used as proximity sensors and for industrial metrology. Their operation relies on a piezoelectric ceramic to generate a flexing of a metallic membrane, which delivers the ultrasound signal. The performance of flexural ultrasonic transducers has been largely limited to excitation through a short voltage burst signal at a designated mechanical resonance frequency. However, a steady-state amplitude response is not generated instantaneously in a flexural ultrasonic transducer from a drive excitation signal, and differences in the drive characteristics between transmitting and receiving transducers can affect the measured response. This research investigates the dynamic performance of flexural ultrasonic transducers using acoustic microphone measurements and laser Doppler vibrometry, supported by a detailed mechanical analog model, in a process which has not before been applied to the flexural ultrasonic transducer. These techniques are employed to gain insights into the physics of their vibration behaviour, vital for the optimisation of industrial ultrasound systems.

  5. Transducers and arrays for underwater sound

    CERN Document Server

    Butler, John L

    2016-01-01

    This improved and updated second edition covers the theory, development, and design of electro-acoustic transducers for underwater applications. This highly regarded text discusses the basics of piezoelectric and magnetostrictive transducers that are currently being used as well as promising new designs. It presents the basic acoustics as well as the specific acoustics data needed in transducer design and evaluation. A broad range of designs of projectors and hydrophones are described in detail along with methods of modeling, evaluation, and measurement. Analysis of projector and hydrophone transducer arrays, including the effects of mutual radiation impedance and numerical models for elements and arrays, are also covered. The book includes new advances in transducer design and transducer materials and has been completely reorganized to be suitable for use as a textbook, as well as a reference or handbook. The new edition contains updates to the first edition, end-of-chapter exercises, and solutions to select...

  6. Neoadjuvant hormonal therapy and external-beam radiotherapy versus external-beam irradiation alone for prostate cancer. A quality-of-life analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pinkawa, Michael; Piroth, Marc D.; Asadpour, Branka; Gagel, Bernd; Fischedick, Karin; Siluschek, Jaroslav; Kehl, Mareike; Krenkel, Barbara; Eble, Michael J. [RWTH Aachen (Germany). Dept. of Radiotherapy

    2009-02-15

    To evaluate the impact of neoadjuvant hormonal therapy (NHT) on quality of life after external-beam radiotherapy (EBRT) for prostate cancer. A group of 170 patients (85 with and 85 without NHT) has been surveyed prospectively before EBRT (70.2-72 Gy), at the last day of EBRT, a median time of 2 months and 15 months after EBRT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Pairs with and without NHT (median treatment time of 3.5 months before EBRT) were matched according to the respective planning target volume and prostate volume. Before EBRT, significantly lower urinary function/bother, sexual function and hormonal function/bother scores were found for patients with NHT. More than 1 year after EBRT, only sexual function scores remained lower. In a multivariate analysis, NHT and adjuvant hormonal therapy (HT) versus NHT only (hazard ratio 14; 95% confidence interval 2.7-183; p = 0.02) and luteinizing hormone-releasing hormone (LHRH) agonists versus antiandrogens (hazard ratio 3.6; 95% confidence interval 1.1-12; p = 0.04) proved to be independent risk factors for long-term erectile dysfunction (no or very poor ability to have an erection). With the exception of sexual function (additional adjuvant HT and application of LHRH analog independently adverse), short-term NHT was not found to decrease quality of life after EBRT for prostate cancer. (orig.)

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... cord. Some exams may use different transducers (with different capabilities) during a single exam. The transducer sends out high-frequency sound waves (that the human ear cannot hear) into the body and then listens for the returning echoes from ...

  8. Prostate cancer

    International Nuclear Information System (INIS)

    Bey, P.; Beckendorf, V.; Stines, J.

    2001-01-01

    Radiation therapy of prostate carcinoma with a curative intent implies to treat the whole prostate at high dose (at least 66 Gy). According to clinical stage, PSA level, Gleason's score, the clinical target volume may include seminal vesicles and less often pelvic lymph nodes. Microscopic extra-capsular extension is found in 15 to 60% of T1-T2 operated on, specially in apex tumors. On contrary, cancers developing from the transitional zone may stay limited to the prostate even with a big volume and with a high PSA level. Zonal anatomy of the prostate identifies internal prostate, including the transitional zone (5% of the prostate in young people). External prostate includes central and peripheral zones. The inferior limit of the prostate is not lower than the inferior border of the pubic symphysis. Clinical and radiological examination: ultrasonography, nuclear magnetic resonance (NMR), CT-scan identify prognostic factors as tumor volume, capsule effraction, seminal vesicles invasion and lymph node extension. The identification of the clinical target volume is now done mainly by CT-Scan which identifies prostate and seminal vesicles. NMR could be helpful to identify more precisely prostate apex. The definition of margins around the clinical target volume has to take in account daily reproducibility and organ motion and of course the maximum tolerable dose for organs at risk. (authors)

  9. Standards for dielectric elastomer transducers

    International Nuclear Information System (INIS)

    Carpi, Federico; Frediani, Gabriele; Anderson, Iain; Bauer, Siegfried; Gallone, Giuseppe; Gei, Massimiliano; Graaf, Christian; Jean-Mistral, Claire; Kaal, William; Kofod, Guggi; Kollosche, Matthias; Kornbluh, Roy; Pelrine, Ron; Lassen, Benny; Rechenbach, Björn; Matysek, Marc; Michel, Silvain; Nowak, Stephan; O’Brien, Benjamin; Pei, Qibing

    2015-01-01

    Dielectric elastomer transducers consist of thin electrically insulating elastomeric membranes coated on both sides with compliant electrodes. They are a promising electromechanically active polymer technology that may be used for actuators, strain sensors, and electrical generators that harvest mechanical energy. The rapid development of this field calls for the first standards, collecting guidelines on how to assess and compare the performance of materials and devices. This paper addresses this need, presenting standardized methods for material characterisation, device testing and performance measurement. These proposed standards are intended to have a general scope and a broad applicability to different material types and device configurations. Nevertheless, they also intentionally exclude some aspects where knowledge and/or consensus in the literature were deemed to be insufficient. This is a sign of a young and vital field, whose research development is expected to benefit from this effort towards standardisation. (paper)

  10. Standards for dielectric elastomer transducers

    Science.gov (United States)

    Carpi, Federico; Anderson, Iain; Bauer, Siegfried; Frediani, Gabriele; Gallone, Giuseppe; Gei, Massimiliano; Graaf, Christian; Jean-Mistral, Claire; Kaal, William; Kofod, Guggi; Kollosche, Matthias; Kornbluh, Roy; Lassen, Benny; Matysek, Marc; Michel, Silvain; Nowak, Stephan; O'Brien, Benjamin; Pei, Qibing; Pelrine, Ron; Rechenbach, Björn; Rosset, Samuel; Shea, Herbert

    2015-10-01

    Dielectric elastomer transducers consist of thin electrically insulating elastomeric membranes coated on both sides with compliant electrodes. They are a promising electromechanically active polymer technology that may be used for actuators, strain sensors, and electrical generators that harvest mechanical energy. The rapid development of this field calls for the first standards, collecting guidelines on how to assess and compare the performance of materials and devices. This paper addresses this need, presenting standardized methods for material characterisation, device testing and performance measurement. These proposed standards are intended to have a general scope and a broad applicability to different material types and device configurations. Nevertheless, they also intentionally exclude some aspects where knowledge and/or consensus in the literature were deemed to be insufficient. This is a sign of a young and vital field, whose research development is expected to benefit from this effort towards standardisation.

  11. Margin Evaluation in the Presence of Deformation, Rotation, and Translation in Prostate and Entire Seminal Vesicle Irradiation With Daily Marker-Based Setup Corrections

    International Nuclear Information System (INIS)

    Mutanga, Theodore F.; Boer, Hans C.J. de; Wielen, Gerard J. van der; Hoogeman, Mischa S.; Incrocci, Luca; Heijmen, Ben J.M.

    2011-01-01

    Purpose: To develop a method for margin evaluation accounting for all measured displacements during treatment of prostate cancer. Methods and Materials: For 21 patients treated with stereographic targeting marker-based online translation corrections, dose distributions with varying margins and gradients were created. Sets of possible cumulative delivered dose distributions were simulated by moving voxels and accumulating dose per voxel. Voxel motion was simulated consistent with measured distributions of systematic and random displacements due to stereographic targeting inaccuracies, deformation, rotation, and intrafraction motion. The method of simulation maintained measured correlation of voxel motions due to organ deformation. Results: For the clinical target volume including prostate and seminal vesicles (SV), the probability that some part receives <95% of the prescribed dose, the changes in minimum dose, and volume receiving 95% of prescription dose compared with planning were 80.5% ± 19.2%, 9.0 ± 6.8 Gy, and 3.0% ± 3.7%, respectively, for the smallest studied margins (3 mm prostate, 5 mm SV) and steepest dose gradients. Corresponding values for largest margins (5 mm prostate, 8 mm SV) with a clinical intensity-modulated radiotherapy dose distribution were 46.5% ± 34.7%, 6.7 ± 5.8 Gy, and 1.6% ± 2.3%. For prostate-only clinical target volume, the values were 51.8% ± 17.7%, 3.3 ± 1.6 Gy, and 0.6% ± 0.5% with the smallest margins and 5.2% ± 7.4%, 1.8 ± 0.9 Gy, and 0.1% ± 0.1% for the largest margins. Addition of three-dimensional rotation corrections only improved these values slightly. All rectal planning constraints were met in the actual reconstructed doses for all studied margins. Conclusion: We developed a system for margin validation in the presence of deformations. In our population, a 5-mm margin provided sufficient dosimetric coverage for the prostate. In contrast, an 8-mm SV margin was still insufficient owing to deformations. Addition of

  12. A new high performance current transducer

    International Nuclear Information System (INIS)

    Tang Lijun; Lu Songlin; Li Deming

    2003-01-01

    A DC-100 kHz current transducer is developed using a new technique on zero-flux detecting principle. It was shown that the new current transducer is of high performance, its magnetic core need not be selected very stringently, and it is easy to manufacture

  13. Treatment of localized prostate cancer using a combination of high dose rate lridium-192 brachytherapy and external beam irradiation: Initial Australian experience

    International Nuclear Information System (INIS)

    Stevens, M.J.; Stricker, P.D.; Brenner, P.C.; Kooner, R.; O'Neil, G.F.A.; Duval, P.J.; Jagavkar, R.S.; Cross, P.; Saalfeld, J.; Martland, J.

    2003-01-01

    Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate- and high-risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate-specific antigen progression-free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability. Copyright (2003) Blackwell Science Pty Ltd

  14. Progress in Gene Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Kamran A.; Davis, Brian J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Wilson, Torrence M. [Department of Urology, Mayo Clinic, Rochester, MN (United States); Wiseman, Gregory A. [Division of Nuclear Medicine, Mayo Clinic, Rochester, MN (United States); Federspiel, Mark J. [Department of Molecular Medicine, Mayo Clinic, Rochester, MN (United States); Morris, John C., E-mail: davis.brian@mayo.edu [Division of Endocrinology, Mayo Clinic, Rochester, MN (United States)

    2012-11-19

    Gene therapy has held promise to correct various disease processes. Prostate cancer represents the second leading cause of cancer death in American men. A number of clinical trials involving gene therapy for the treatment of prostate cancer have been reported. The ability to efficiently transduce tumors with effective levels of therapeutic genes has been identified as a fundamental barrier to effective cancer gene therapy. The approach utilizing gene therapy in prostate cancer patients at our institution attempts to address this deficiency. The sodium-iodide symporter (NIS) is responsible for the ability of the thyroid gland to transport and concentrate iodide. The characteristics of the NIS gene suggest that it could represent an ideal therapeutic gene for cancer therapy. Published results from Mayo Clinic researchers have indicated several important successes with the use of the NIS gene and prostate gene therapy. Studies have demonstrated that transfer of the human NIS gene into prostate cancer using adenovirus vectors in vitro and in vivo results in efficient uptake of radioactive iodine and significant tumor growth delay with prolongation of survival. Preclinical successes have culminated in the opening of a phase I trial for patients with advanced prostate disease which is currently accruing patients. Further study will reveal the clinical promise of NIS gene therapy in the treatment of prostate as well as other malignancies.

  15. Progress in Gene Therapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Ahmed, Kamran A.; Davis, Brian J.; Wilson, Torrence M.; Wiseman, Gregory A.; Federspiel, Mark J.; Morris, John C.

    2012-01-01

    Gene therapy has held promise to correct various disease processes. Prostate cancer represents the second leading cause of cancer death in American men. A number of clinical trials involving gene therapy for the treatment of prostate cancer have been reported. The ability to efficiently transduce tumors with effective levels of therapeutic genes has been identified as a fundamental barrier to effective cancer gene therapy. The approach utilizing gene therapy in prostate cancer patients at our institution attempts to address this deficiency. The sodium-iodide symporter (NIS) is responsible for the ability of the thyroid gland to transport and concentrate iodide. The characteristics of the NIS gene suggest that it could represent an ideal therapeutic gene for cancer therapy. Published results from Mayo Clinic researchers have indicated several important successes with the use of the NIS gene and prostate gene therapy. Studies have demonstrated that transfer of the human NIS gene into prostate cancer using adenovirus vectors in vitro and in vivo results in efficient uptake of radioactive iodine and significant tumor growth delay with prolongation of survival. Preclinical successes have culminated in the opening of a phase I trial for patients with advanced prostate disease which is currently accruing patients. Further study will reveal the clinical promise of NIS gene therapy in the treatment of prostate as well as other malignancies.

  16. Prostate cancer

    International Nuclear Information System (INIS)

    Spera, G.

    2010-01-01

    This work is about diagnosis, treatment and monitoring of prostate cancer. The techniques used are: transrectal ultrasound, laparascopy, bone scan, chest x-ray, radiography, chemoterapy and radiotherapy

  17. Prostate Ultrasound

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also called transrectal ultrasound, provides ...

  18. Using Portable Transducers to Measure Tremor Severity

    Directory of Open Access Journals (Sweden)

    Rodger Elble

    2016-05-01

    Full Text Available Background: Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor. Methods: Medline was searched via PubMed.gov in December 2015 using the Boolean expression “tremor AND (accelerometer OR accelerometry OR gyroscope OR inertial measurement unit OR digitizing tablet OR transducer.” Abstracts of 419 papers dating back to 1964 were reviewed for relevant portable transducers and methods of tremor analysis, and 105 papers written in English were reviewed in detail. Results: Accelerometers, gyroscopes, and digitizing tablets are used most commonly, but few are sold for the purpose of measuring tremor. Consequently, most software for tremor analysis is developed by the user. Wearable transducers are capable of recording tremor continuously, in the absence of a clinician. Tremor amplitude, frequency, and occurrence (percentage of time with tremor can be computed. Tremor amplitude and occurrence correlate strongly with clinical ratings of tremor severity. Discussion: Transducers provide measurements of tremor amplitude that are objective, precise, and valid, but the precision and accuracy of transducers are mitigated by natural variability in tremor amplitude. This variability is so great that the minimum detectable change in amplitude, exceeding random variability, is comparable for scales and transducers. Research is needed to determine the feasibility of detecting smaller change using averaged data from continuous long-term recordings with wearable transducers.

  19. Comparison of hypo-fractional irradiation protocols used in the treatment of prostate cancer by external radiotherapy; Porovnanie hypofrakcionacnych ozarovacich protokolov pouzivanych v liecbe karcinomu prostaty pomocou externej radioterapie

    Energy Technology Data Exchange (ETDEWEB)

    Petruskova, B. [Univerzita Pavla Jozefa Safarika, Ustav fyzikalnych vied, Katedra jadrovej a subjadrovej fyziky, 04001 Kosice (Slovakia); Matula, P.; Koncik, J.; Jasencak, M. [Vychodoslovensky onkologicky ustav, a.s., 04001 Kosice (Slovakia)

    2013-04-16

    The main aim of this study is to compare two hypo-fractionated protocols used in the radiotherapy of prostate cancer in terms of late complications in normal tissue. 50 patients in first protocol were irradiated with the dose of 52,8 Gy in 16 fractions. 52 patients included in the second protocol were irradiated with the dose of 62 Gy in 20 fractions. Protocols were compared through dose-volume histograms (DVH) of rectum and bladder and radiobiological calculations with the use of Lyman-Kutcher-Burman model for Normal Tissue Complication Probability (NTCP). Results of NTCP were compared with real incidence of late toxicity for normal tissue. DVH of rectum and bladder for patients from second protocol have a better behavior then DVHs for patients from first protocol. NTCPs for first protocol are (12,5{+-}3,3)% and (1,6{+-}1,3)% for rectum and bladder, respectively. NTCPs for second protocol are (6,8{+-}3,0)% and (0,53{+-}0,9)% for rectum and bladder, respectively. From comparison of results of radiobiological calculations and real incidence had arisen a need of refinement of parameters of LKB model. (authors)

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... composition of body tissue through which the sound travels. A small amount of gel is put on the skin to allow the sound waves to travel from the transducer to the examined area within ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ... abnormal masses, such as tumors. In an ultrasound examination, a transducer both sends the sound waves into ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... of page What will I experience during and after the procedure? Ultrasound exams in which the transducer ... in the sperm or urine following the procedure. After an ultrasound examination, you should be able to ...

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... consist of a console containing a computer and electronics, a video display screen and a transducer that ... suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank you! Please help ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  7. Capacitance high temperature strain transducer by Interatom

    International Nuclear Information System (INIS)

    Fortmann, M.

    1987-01-01

    Special strain transducers are necessary to perform structure mechanical experiments on real components under creep-fatigue load. The new development of the transducer was able to solve the problem. In the meantime, different characteristics of the transducer have been examined and many successful applications have been effected. Some important aspects are given in this report. Up to now the longest operation period has been 24000 h on a pipe at 630 0 C service temperature in a conventional power station. (orig./DG) [de

  8. Long-Term Treatment Sequelae After External Beam Irradiation With or Without Hormonal Manipulation for Adenocarcinoma of the Prostate: Analysis of Radiation Therapy Oncology Group Studies 85-31, 86-10, and 92-02

    International Nuclear Information System (INIS)

    Lawton, Colleen A.; Bae, Kyoungwha; Pilepich, Miljenko; Hanks, Gerald; Shipley, William

    2008-01-01

    Purpose: Late gastrointestinal (GI) and genitourinary (GU) morbidity from external beam irradiation used to treat adenocarcinoma of the prostate continue to be a concern of physicians and patients alike. In addition, for locally advanced/high-risk cancer, the appropriate use of hormonal manipulation in addition to radiation therapy (RT) may increase toxicity. We analyzed three large Radiation Therapy Oncology Group (RTOG) studies (85-31, 86-10, and 92-02) to try to address these issues. Methods and Materials: A total of 2,922 patients were accrued with a median follow-up of 10.3 years for surviving patients. The RTOG scoring scheme was used to assess GI, GU, and other toxicities. Toxicity reported was Grade 3 or higher late toxicity. Patient toxicity level was assessed by study and by treatment type combining RT only vs. RT + short-course hormone therapy (STH) vs. RT + long-term hormone therapy (LTH). Results: Multivariate analysis reveals that age >70 was statistically significantly associated with a decrease in late any Grade 3+ toxicity (hazard ratio [HR] = 0.78, p = 0.0476) adjusted for treatment type. Comparing treatment type, patients treated with RT+STH had a statistically significant lower probability of Grade 3+ GI, GU, and other toxicity compared with RT alone (p = .00006; p = 0.0037; p = 0.0127, respectively). Patients treated with RT+LTH had a statistically significant lower probability of Grade 3+ GU toxicity compared with RT alone (p = 0.023). Conclusions: These data show that external beam radiation therapy remains a safe option for locally advanced/high-risk prostate cancer, and the use of hormonal manipulation does appear to be protective for GU and GI toxicity depending upon length of treatment

  9. Targeting Radiation Therapy for Developing Dendritic Cell Based Immunotherapy of Metastatic Prostate Cancer

    National Research Council Canada - National Science Library

    Chakravarty, Prabir K

    2006-01-01

    .... The hypothesis was tested using a murine prostate cancer model, RM-1. The study showed that irradiation induces apoptosis and the irradiated tumor cells were able to activate dendritic cells and stimulate tumor specific immune response in vitro...

  10. Transducers and microprocessors in oceanographic applications

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, R.G.P.; Desa, E.

    Transducers used for the sensing of the ten most measured marine parameters have been described in this paper. The ten parameters have been classed under 5 sensor types, namely temperature, pressure, salinity, currents and waves. For each sensor...

  11. Identification and comparison of predictive models of rectal and bladder toxicity in the case of prostatic irradiation; Identification et comparaison de modeles predictifs de toxicite rectale et vesicale en cas d'irradiation prostatique

    Energy Technology Data Exchange (ETDEWEB)

    Gnep, K.; Chira, C.; Le Prise, E.; Crevoisier, R. de [Centre Eugene-Marquis, Rennes (France); Zhu, J.; Simon, A.; Ospina Arango, J.D. [Inserm U642, Rennes (France); Messai, T.; Bossi, A. [Institut Gustave-Roussy, Villejuif (France); Beckendorf, V. [Centre Alexis-Vautrin, Nancy (France)

    2011-10-15

    More than 400 patients have been treated by conformational radiation therapy for a localized prostate adenocarcinoma and some have been selected according to the availability of dose-volume histograms. Predictive models of rectal and bladder toxicity have been compared: LKB, Logit EUD and Poisson EUD for rectal toxicity, LKB, Logit EUD, Poisson EUD and Schultheiss for bladder toxicity. Results suggest that these models could be used during the inverse planning of intensity-modulated radiation therapy in order to decrease toxicity. Short communication

  12. Performance of Honeywell silicon pressure transducers

    Digital Repository Service at National Institute of Oceanography (India)

    VijayKumar, K.; Joseph, A.; Desai, R.G.P.; Nagvekar, S.; Prabhudesai, S.; Damodaran, V.

    pressure. The precision pressure transducer – ruggedized (PPTR) manufactured by Honeywell is provided with a special “Hastelloy” material isolation-diaphragm to protect the transducer port against corrosive effects during its prolonged exposure...-scale output (an intelligent technique anufacturers to hide the non-linearity of the product at all data points below ore realistic estimate of linearity is obtained by ean of a few samples) based on the corresponding true ethod employed by performance...

  13. Xanthogranulomatous Prostatitis, a Rare Prostatic Entity

    Directory of Open Access Journals (Sweden)

    Alejandro Noyola

    2017-01-01

    Full Text Available There are several benign prostatic pathologies that can clinically mimic a prostate adenocarcinoma. Xanthogranulomatous prostatitis is a benign inflammatory condition of the prostate and a rare entity. A 47-year old male, with 3 years of lower urinary tract symptoms, with a palpable hypogastric tumor, digital rectal examination: solid prostate, of approximately 60 g. Initial PSA was 0.90 ng/mL. He underwent surgical excision of the lower abdominal nodule and prostatectomy. Histopathology showed xanthogranulomatous prostatitis, without malignancy. Xanthogranulomatous prostatitis is an extremely rare entity that can simulate prostate adenocarcinoma, therefore having a correct histopathological diagnosis is essential.

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... This procedure requires little to no special preparation. Leave jewelry at home and wear loose, comfortable clothing. ... BPH) , with measurements acquired as needed for any treatment planning. detect an abnormal growth within the prostate. ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the rectum. The images are obtained from different angles to get the best view of the prostate ... RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical questions or for ...

  16. Prostate Ultrasound

    Medline Plus

    Full Text Available ... nodule felt by a physician during a routine physical exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time ...

  17. Enlarged prostate

    Science.gov (United States)

    ... for drugs that may make your symptoms worse : SAW PALMETTO Many herbs have been tried for treating an enlarged prostate. Many men use saw palmetto to ease symptoms. Some studies have shown that ...

  18. Prostate biopsy

    Science.gov (United States)

    ... give the cells a grade called a Gleason score . This helps predict how fast the cancer will ... TRUS); Stereotactic transperineal prostate biopsy (STPB) Images Male reproductive anatomy References Babayan RK, Katz MH. Biopsy prophylaxis, ...

  19. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the rectal wall is relatively insensitive to the pain in the region of the prostate. A biopsy ... needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... diagnose symptoms such as difficulty urinating or an elevated blood test result. It’s also used to investigate ... physical exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides ...

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... less than 20 minutes. top of page What will I experience during and after the procedure? Ultrasound ... in the region of the prostate. A biopsy will add time to the procedure. Rarely, a small ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... receiver coil. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top ... To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... with measurements acquired as needed for any treatment planning. detect an abnormal growth within the prostate. help ... end of their bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the ...

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... prostate gland and to help diagnose symptoms such as difficulty urinating or an elevated blood test result. ... image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is no ...

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... nodule felt by a physician during a routine physical exam or prostate cancer screening exam. an elevated ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  6. Prostatitis - acute

    Science.gov (United States)

    ... tender scrotum The provider may perform a digital rectal exam to examine your prostate. During this exam, ... Copyright 1997-2018, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing ...

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... receiver coil. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top ... here Images × Image Gallery Radiologist and patient consultation. View full size with caption Related Articles and Media ...

  8. Prostate Ultrasound

    Medline Plus

    Full Text Available ... needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on ... and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top of page This page was reviewed on ...

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ... bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the prostate gland because ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Images related to Ultrasound - Prostate Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... phased array) receiver coil. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Prostate ... Send us your feedback Did you find the information you were looking for? Yes No Please type ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... in which a needle is used to sample cells (tissue) from an abnormal area in the prostate ... needle insertion) is usually minimal because the rectal wall is relatively insensitive to the pain in the ...

  13. Prostate Ultrasound

    Medline Plus

    Full Text Available ... also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any treatment planning. detect ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... physician during a routine physical exam or prostate cancer screening exam. an elevated blood test result. difficulty ... if a patient is at high risk for cancer. In this case, a biopsy is performed and ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... rectum into the prostate gland which is situated right in front of the rectum. top of page ... creates a real-time picture on the monitor. One or more frames of the moving pictures are ...

  16. Prostate Ultrasound

    Medline Plus

    Full Text Available ... probe sends and receives sound waves through the wall of the rectum into the prostate gland which ... needle insertion) is usually minimal because the rectal wall is relatively insensitive to the pain in the ...

  17. Prostate cancer

    DEFF Research Database (Denmark)

    Chabanova, Elizaveta; Balslev, Ingegerd; Logager, Vibeke

    2011-01-01

    To investigate diagnostic accuracy of detection of prostate cancer by magnetic resonance: to evaluate the performance of T2WI, DCEMRI and CSI and to correlate the results with biopsy and radical prostatectomy histopathological data.......To investigate diagnostic accuracy of detection of prostate cancer by magnetic resonance: to evaluate the performance of T2WI, DCEMRI and CSI and to correlate the results with biopsy and radical prostatectomy histopathological data....

  18. Potential interest to combine an intensity modulated conformal radiotherapy (I.M.C.R.T.) with a daily repositioning on intra-prostate implants to reduce sexual toxicity induced by exclusive irradiation of prostate cancers; Interets potentiels de combiner une radiotherapie de conformation avec modulation d'intensite (RCMI) avec un repositionnement journalier sur implants intraprostatiques pour reduire la toxicite sexuelle induite par l'irradiation exclusive des cancers de prostate

    Energy Technology Data Exchange (ETDEWEB)

    Chapet, O.; Sotton, M.P.; Vial, L.; Belliere, A.; Ardiet, J.M.; Mornex, F.; Sentenac, I.; Romestaing, P. [Centre Hospitalier Lyon-Sud, Dept. de Radiotherapie-oncologie, 69 - Pierre-Benite (France); Bouffard, J. [Centre Hospitalier Lyon-Sud, Service de Radiologie, 69 - Pierre-Benite (France)

    2007-11-15

    A reduction in margins defining the forecast target volume thanks to a daily repositioning on intra prostate implants would reduce the doses delivered to the penis bulb, corpora cavernosa penis and a. pudendae internae left and right. An optimization of the I.M.C.R.T. on the same anatomical structures amplifies this earnings. The combination of the two could improve the sexual preservation and be proposed for patients with favourable stage prostate cancer. A study of Phase 2 begins soon. (N.C.)

  19. High temperature ultrasonic transducers for imaging and measurements in a liquid Pb/Bi eutectic alloy.

    Science.gov (United States)

    Kazys, Rymantas; Voleisis, Algirdas; Sliteris, Reimondas; Mazeika, Liudas; Van Nieuwenhove, Rudi; Kupschus, Peter; Abderrahim, Hamid Aït

    2005-04-01

    In some nuclear reactors or accelerator-driven systems (ADS) the core is intended to be cooled by means of a heavy liquid metal, for example, lead-bismuth (Pb/Bi) eutectic alloy. For safety and licensing reasons, an imaging method of the interior of ADS, based on application of ultrasonic waves, has thus to be developed. This paper is devoted to description of developed various ultrasonic transducers suitable for long term imaging and measurements in the liquid Pb/Bi alloy. The results of comparative experimental investigations of the developed transducers of different designs in a liquid Pb/Bi alloy up to 450 degrees C are presented. Prototypes with different high temperature piezoelectric materials were investigated: PZT, bismuth titanate (Bi4Ti3O12), lithium niobate (LiNbO3), gallium orthophosphate (GaPO4) and aluminum nitride (A1N). For acoustic coupling with the metal alloy, it was proposed to coat the active surface of the transducers by diamond like carbon (DLC). The radiation robustness was assessed by exposing the transducers to high gamma dose rates in one of the irradiation facilities at SCK x CEN. The experimental results proved that the developed transducers are suitable for long-term operation in harsh conditions.

  20. Introduction to special session on "ultrasonic transducers for harsh environments

    Science.gov (United States)

    Tittmann, B. R.; Reinhardt, B.; Daw, J.

    2018-04-01

    This work describes the results of experiments conducted as part of an instrumented lead test in-core in a nuclear reactor with the piezoelectric and magnetostrictive materials. The experiments exposed AlN, ZnO, BiT, Remendur, and Galfenol to more neutron radiation than found in the literature. The magnetostrictive sensors produce stable ultrasonic pulse-echoes throughout much of the irradiation. The BiT transducers could operate up until approximate 5 × 10^20 n/cm^2 (E>1MeV). The piezoelectric AlN operated well during the entire experiment. The results imply that now available are candidates for operation in harsh environments found in nuclear reactors and steam generator plants.

  1. The clinical value of MR elastography in the diagnosis of prostate cancer

    International Nuclear Information System (INIS)

    Chen Min; Li Saying; Wang Wenchao; Zhao Weifeng; Yang Zhenghan; Liu Ming; Zhou Cheng

    2010-01-01

    Objective: To investigate the clinical value of MR elastography in the diagnosis of prostate cancer at 3.0 T, and to assess the elasticity and viscosity of prostate cancer and benign prostatic diseases. Methods: Eight patients (63±7 years old) with 12 foci of prostate cancer and 10 patients (59±3 years old) with 14 foci of prostatitis in the peripheral zone were evaluated by MR elastography. MR elastography was performed by transmitting low-frequency longitudinal mechanical waves of 100 Hz into prostate with a transducer placed above the pubic bones. The phase images were reconstructed to acquire viscoelastic mapping. t test was used to compare the mean elasticity and viscosity of prostate cancer and prostatitis. The correlation of elasticity and Gleason scores between prostate cancer and prostatitis were also retrospectively analyzed with Pearson Correlation. Results: The mean elasticity and viscosity were significantly higher in prostate cancer [(6.55±0.47) kPa, (6.56±0.99) Pa·s, respectively] than in prostatitis [(1.99±0.66) kPa, (2.13±0.21) Pa·s, respectively], and the difference was statistically significant (t=19.392, 16.372; P<0.01). In 8 patients with prostate cancer, the Gleason scores were 5 (2 cases), 6 (3 cases), 7 (2 cases) and 8 (1 case), respectively. The mean elasticity for the cases with different Gleason scores was 5.83, 6.02, 7.45 and 8.05 kPa, respectively. There was a positive correlation between Gleason scores and elasticity of the prostate cancer(r=0.913, P<0.01) in this study. Conclusion: MR elastography can be used to visualize the difference in stiffness between prostate cancer and benign prostatic disease, it is a new imaging method with great potential in grading of prostate cancer. (authors)

  2. High Temperature, High Power Piezoelectric Composite Transducers

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  3. Comparison of prostate contours between conventional stepping transverse imaging and Twister-based sagittal imaging in permanent interstitial prostate brachytherapy.

    Science.gov (United States)

    Kawakami, Shogo; Ishiyama, Hiromichi; Satoh, Takefumi; Tsumura, Hideyasu; Sekiguchi, Akane; Takenaka, Kouji; Tabata, Ken-Ichi; Iwamura, Masatsugu; Hayakawa, Kazushige

    2017-08-01

    To compare prostate contours on conventional stepping transverse image acquisitions with those on twister-based sagittal image acquisitions. Twenty prostate cancer patients who were planned to have permanent interstitial prostate brachytherapy were prospectively accrued. A transrectal ultrasonography probe was inserted, with the patient in lithotomy position. Transverse images were obtained with stepping movement of the transverse transducer. In the same patient, sagittal images were also obtained through rotation of the sagittal transducer using the "Twister" mode. The differences of prostate size among the two types of image acquisitions were compared. The relationships among the difference of the two types of image acquisitions, dose-volume histogram (DVH) parameters on the post-implant computed tomography (CT) analysis, as well as other factors were analyzed. The sagittal image acquisitions showed a larger prostate size compared to the transverse image acquisitions especially in the anterior-posterior (AP) direction ( p transverse image acquisitions was correlated to DVH parameters such as D 90 ( R = 0.518, p = 0.019), and V 100 ( R = 0.598, p = 0.005). There were small but significant differences in the prostate contours between the transverse and the sagittal planning image acquisitions. Furthermore, our study suggested that the differences between the two types of image acquisitions might correlated to dosimetric results on CT analysis.

  4. RapidArc, intensity modulated photon and proton techniques for recurrent prostate cancer in previously irradiated patients: a treatment planning comparison study

    International Nuclear Information System (INIS)

    Weber, Damien C; Miralbell, Raymond; Wang, Hui; Cozzi, Luca; Dipasquale, Giovanna; Khan, Haleem G; Ratib, Osman; Rouzaud, Michel; Vees, Hansjoerg; Zaidi, Habib

    2009-01-01

    A study was performed comparing volumetric modulated arcs (RA) and intensity modulation (with photons, IMRT, or protons, IMPT) radiation therapy (RT) for patients with recurrent prostate cancer after RT. Plans for RA, IMRT and IMPT were optimized for 7 patients. Prescribed dose was 56 Gy in 14 fractions. The recurrent gross tumor volume (GTV) was defined on 18 F-fluorocholine PET/CT scans. Plans aimed to cover at least 95% of the planning target volume with a dose > 50.4 Gy. A maximum dose (D Max ) of 61.6 Gy was allowed to 5% of the GTV. For the urethra, D Max was constrained to 37 Gy. Rectal D Median was < 17 Gy. Results were analyzed using Dose-Volume Histogram and conformity index (CI 90 ) parameters. Tumor coverage (GTV and PTV) was improved with RA (V 95% 92.6 ± 7.9 and 83.7 ± 3.3%), when compared to IMRT (V 95% 88.6 ± 10.8 and 77.2 ± 2.2%). The corresponding values for IMPT were intermediate for the GTV (V 95% 88.9 ± 10.5%) and better for the PTV (V 95% 85.6 ± 5.0%). The percentages of rectal and urethral volumes receiving intermediate doses (35 Gy) were significantly decreased with RA (5.1 ± 3.0 and 38.0 ± 25.3%) and IMPT (3.9 ± 2.7 and 25.1 ± 21.1%), when compared to IMRT (9.8 ± 5.3 and 60.7 ± 41.7%). CI 90 was 1.3 ± 0.1 for photons and 1.6 ± 0.2 for protons. Integral Dose was 1.1 ± 0.5 Gy*cm 3 *10 5 for IMPT and about a factor three higher for all photon's techniques. RA and IMPT showed improvements in conformal avoidance relative to fixed beam IMRT for 7 patients with recurrent prostate cancer. IMPT showed further sparing of organs at risk

  5. Chemical disease-free survival in localized carcinoma of prostate treated with external beam irradiation: comparison of American Society of Therapeutic Radiology and Oncology Consensus or 1 ng/mL as endpoint

    International Nuclear Information System (INIS)

    Perez, Carlos A.; Michalski, Jeff M.; Lockett, Mary Ann

    2001-01-01

    Purpose: To compare postirradiation biochemical disease-free survival using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus or elevation of postirradiation prostate-specific antigen (PSA) level beyond 1 ng/mL as an endpoint and correlate chemical failure with subsequent appearance of clinically detected local recurrence or distant metastasis. Methods and Materials: Records of 466 patients with histologically confirmed adenocarcinoma of the prostate treated with irradiation alone between January 1987 and December 1995 were analyzed; 339 patients were treated with bilateral 120 deg. arc rotation and, starting in 1992, 117 with three-dimensional conformal irradiation. Doses were 68-77 Gy in 1.8 to 2 Gy daily fractions. Minimum follow-up is 4 years (mean, 5.5 years; maximum, 9.6 years). A chemical failure was recorded using the ASTRO Consensus or when postirradiation PSA level exceeded 1 ng/mL at any time. Clinical failures were determined by rectal examination, radiographic studies, and, when clinically indicated, biopsy. Results: Six-year chemical disease-free survival rates using the ASTRO Consensus according to pretreatment PSA level for T1 tumors were: ≤4 ng/mL, 100%; 4.1-20 ng/mL, 80%; and >20 ng/mL, 50%. For T2 tumors the rates were: ≤4 ng/mL, 91%; 4.1-10 ng/mL, 81%; 10.1-20 ng/mL, 55%; 20.1-40 ng/mL, 63%; and >40 ng/mL, 46%. When postirradiation PSA levels higher than 1 ng/mL were used, the corresponding 6-year chemical disease-free survival rates for T1 tumors were 92% for pretreatment PSA levels of ≤4 ng/mL, 58-60% for levels of 4.1-20 ng/mL, and 30% for levels >20 ng/mL. For T2 tumors, the 6-year chemical disease-free survival rates were 78% in patients with pretreatment PSA levels of 4-10 ng/mL, 45% for 10.1-40 ng/mL, and 25% for >40 ng/mL. Of 167 patients with T1 tumors, 30 (18%) developed a chemical failure, 97% within 5 years from completion of radiation therapy; no patient has developed a local recurrence or distant

  6. Photoacoustic imaging of early gastric cancer diagnosis based on long focal area ultrasound transducer

    Science.gov (United States)

    Wu, Huaqin; Li, Zuoran; Liu, Lantian; Li, Zhifang; Wu, Shulian; Li, Hui

    2017-06-01

    We illustrated a novel imaging method to diagnose gastric neoplasms via photoacoustic tomography (PAT). Depending on the structural characteristics of gastric cavity, we used column diffusion fiber to irradiate the stomach tissue through the esophagus, and the externally placed telecentric focus ultrasonic transducer detected photoacoustic signals from the gastric tissue. We reconstructed the distribution of light energy deposition of the simulated gastric tumor, and obtained the location and size information of gastric tumor.

  7. Prostatic paracoccidioidomycosis: differential diagnosis of prostate cancer

    Directory of Open Access Journals (Sweden)

    Daniel Lima Lopes

    2009-02-01

    Full Text Available Symptomatic prostatic paracoccidioidomycosis (PCM is a very rare condition; however, it may express as a typical benign prostatic hyperplasia or a simulating prostatic adenocarcinoma. This case report presents PCM mimicking prostatic adenocarcinoma. The purpose of this paper is to call the general physician's attention to this important differential diagnosis.

  8. Role Of Shark Cartilage In Reducing Changes In Gene Expression Of Some Enzymes Induced By N-Nitroso-N-Methyl Urea In Prostate Of Irradiated Rats

    International Nuclear Information System (INIS)

    ELMAGHRABY, T.; YACOUB, S.; IBRAHIM, N.K.

    2009-01-01

    There is overwhelming evidence to indicate that free radicals cause oxidative damage to lipids, proteins and nucleic acids and are involved in the pathogenesis of several diseases. Therefore, antioxidants, which can neutralize free radicals, may be of central importance in the prevention of these diseases. Recent studies demonstrated the role of shark cartilage in protecting cells against reactive oxygen species induced DNA damage and mutagenesis. Reactive oxygen species and other free radicals are known to be the mediators of phenotypic and genotypic changes that lead from mutation to neoplasia. There are some primary antioxidants such as glutathione peroxidase (GSHPx), glutathione-S-transferase (GST-π) and super oxide dismutase (SOD), which protects against cellular and molecular damage caused by the reactive oxygen metabolites (ROMs).In this study, the effect of shark cartilage against the N-nitroso-N-methyl urea + testosterone and/or gamma radiation-induced mutagens and carcinogens in rat prostate were investigated.The data showed significant decrease in gene expression of manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GSHPx1) , enzyme activities of total superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) and non-significant increase in glutathione-S-transferase (GST-π) in N-nitroso-N-methyl urea + testosterone, N-nitroso-N-methyl urea + testosterone + gamma radiation groups as compared to control group.The results revealed that shark cartilage administration afford a significant protective effect against N-nitroso-N-methyl urea + testosterone and/or gamma radiation- induced oxidative injury.

  9. Mechano-electric optoisolator transducer with hysteresis

    International Nuclear Information System (INIS)

    Ciurus, I M; Dimian, M; Graur, A

    2011-01-01

    This article presents a theoretical and experimental study of designing a mechano-electric optoisolator transducer with hysteresis. Our research is centred upon designing transducers on the basis of optical sensors, as photoelectric conversions eliminate the influence of electromagnetic disturbances. Conversion of the rotation/translation motions into electric signals is performed with the help of a LED-photoresistor Polaroid optocoupler. The driver of the optocoupler's transmitter module is an independent current source. The signal conditioning circuit is a Schmitt trigger circuit. The device is designed to be applied in the field of automation and mechatronics.

  10. Immune Algorithm Complex Method for Transducer Calibration

    Directory of Open Access Journals (Sweden)

    YU Jiangming

    2014-08-01

    Full Text Available As a key link in engineering test tasks, the transducer calibration has significant influence on accuracy and reliability of test results. Because of unknown and complex nonlinear characteristics, conventional method can’t achieve satisfactory accuracy. An Immune algorithm complex modeling approach is proposed, and the simulated studies on the calibration of third multiple output transducers is made respectively by use of the developed complex modeling. The simulated and experimental results show that the Immune algorithm complex modeling approach can improve significantly calibration precision comparison with traditional calibration methods.

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... As the sound waves bounce off internal organs, fluids and tissues, the sensitive receiver in the transducer records tiny changes in the sound's pitch and direction. These signature waves are instantly measured and displayed by a computer, which in turn creates a real-time picture ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... body tissue through which the sound travels. A small amount of gel is put on the skin to allow the sound waves to travel from the transducer to the examined area within the body and then back again. Ultrasound ...

  13. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from the area within the patient that is being examined to the transducer (the device placed on the patient's skin to send and ...

  14. A completely calcified prostate

    Directory of Open Access Journals (Sweden)

    Vinod Priyadarshi

    2016-01-01

    Full Text Available Prostatic calcification and prostatic calculus formation is commonly seen in adult population with chronic prostatitis, however, gross prostatic calcification which involves more than 3 cm2 of the gland is quite rare. We are presenting here one such case in which almost whole glandular prostate was converted into stone which is never reported so far.

  15. Failure-free survival following brachytherapy alone or external beam irradiation alone for T1-2 prostate tumors in 2222 patients: results from a single practice

    International Nuclear Information System (INIS)

    Brachman, David G.; Thomas, Theresa; Hilbe, Joseph; Beyer, David C.

    2000-01-01

    Purpose: To evaluate failure-free survival (FFS) for brachytherapy (BT) alone compared to external beam radiotherapy (EBRT) alone for Stage T1-2 Nx-No Mo patients over the same time period by a single community-based practice in the prostate-specific antigen (PSA) era. Materials and Methods: The database of Arizona Oncology Services (a multiphysician radiation oncology practice in the Phoenix metropolitan area) was reviewed for patients meeting the following criteria: (1) T1 or T2 Nx-No Mo prostate cancer; (2) no prior or concurrent therapy including hormones; (3) treatment period 12/88-12/95; and (4) treatment with either EBRT alone or BT alone ( 125 I or 103 Pd). This yielded 1527 EBRT and 695 BT patients; no patients meeting the above criteria were excluded from analysis. Median follow-up for EBRT patients was 41.3 months and, for BT patients, 51.3 months. Patients were not randomized to either therapy but rather received EBRT or BT based upon patient, treating, and/or referring physician preference. PSA failure was defined according to the ASTRO consensus guidelines. The median patient age was 74 years for both groups. Results: Failure-free survival at 5 years for EBRT and BT are 69% and 71%, respectively (p = 0.91). For T stage, no significant difference in FFS at 5 years is observed between EBRT and BT for either T1 (78% vs. 83%, p = 0.47) or T2 (67% vs. 67%, p = 0.89) tumors. Analysis by Gleason score shows superior outcomes for Gleason 8-10 lesions treated with EBRT vs. BT (5-year FFS 52% vs. 28%, p = 0.04); outcomes for lower grade lesions (Gleason 4-6) when analyzed by Gleason score alone do not significantly differ according to treatment received. Patients with initial PSA values of 10-20 ng/dL have an improved FFS with EBRT vs. BT at 5 years (70% vs. 53%, p = 0.001); outcomes for patients with initial PSA ranges of 0-4 ng/dL, of > 4-10 ng/dL, and > 20 ng/dL did not differ significantly by treatment received. FFS was also determined for presenting

  16. External beam radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Forman, Jeffrey D.

    1996-01-01

    Purpose/Objectives: The intent of this course is to review the issues involved in the management of non-metastatic adenocarcinoma of the prostate. -- The value of pre-treatment prognostic factors including stage, grade and PSA value will be presented, and their value in determining therapeutic strategies will be discussed. -- Controversies involving the simulation process and treatment design will be presented. The value of CT scanning, Beams-Eye View, 3-D planning, intravesicle, intraurethral and rectal contrast will be presented. The significance of prostate and patient movement and strategies for dealing with them will be presented. -- The management of low stage, low to intermediate grade prostate cancer will be discussed. The dose, volume and timing of irradiation will be discussed as will the role of neo-adjuvant hormonal therapy, neutron irradiation and brachytherapy. The current status of radical prostatectomy and cryotherapy will be summarized. Treatment of locally advanced, poorly differentiated prostate cancer will be presented including a discussion of neo-adjuvant and adjuvant hormones, dose-escalation and neutron irradiation. -- Strategies for post-radiation failures will be presented including data on cryotherapy, salvage prostatectomy and hormonal therapy (immediate, delayed and/or intermittent). New areas for investigation will be reviewed. -- The management of patients post prostatectomy will be reviewed. Data on adjuvant radiation and therapeutic radiation for biochemical or clinically relapsed patients will be presented. This course hopes to present a realistic and pragmatic overview for treating patients with non-metastatic prostatic cancer

  17. Fiber-optic coupled pressure transducer

    International Nuclear Information System (INIS)

    Tallman, C.R.; Wingate, F.P.; Ballard, E.O.

    1979-01-01

    A fiber-optic coupled pressure transducer was developed for measurement of pressure transients produced by fast electrical discharges in laser cavities. A detailed description of the design and performance will be given. Shock tube performance and measurements in direct electrical discharge regions will be presented

  18. Eliminating transducer distortion in acoustic measurements

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Torras Rosell, Antoni; McWalter, Richard Ian

    2014-01-01

    This paper investigates the in uence of nonlinear components that contaminate the linear response of acoustic transducer, and presents a method for eliminating the in uence of nonlinearities in acoustic measurements. The method is evaluated on simulated as well as experimental data, and is shown...

  19. Ferroelectret non-contact ultrasonic transducers

    Czech Academy of Sciences Publication Activity Database

    Bovtun, Viktor; Döring, J.; Bartusch, J.; Beck, U.; Erhard, A.; Yakymenko, Y.

    2007-01-01

    Roč. 88, č. 4 (2007), s. 737-743 ISSN 0947-8396 R&D Projects: GA ČR(CZ) GA202/06/0403 Institutional research plan: CEZ:AV0Z10100520 Keywords : ferroelectrets * polymers * ultrasonic transducers Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.857, year: 2007

  20. Linearization of resistance thermometers and other transducers

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1970-01-01

    deflection output or to null balance output. The application to the common temperature transducers is considered. It is shown that thermistors, linear metals (e.g., copper), and nickel can be linearized in terms of temperature, but platinum cannot be. If linearization is desired in terms of the reciprocal...

  1. Characterisation and Modelling of MEMS Ultrasonic Transducers

    International Nuclear Information System (INIS)

    Teng, M F; Hariz, A J

    2006-01-01

    Silicon ultrasonic transducer micro arrays based on micro-electro-mechanicalsystem (MEMS) technologies are gaining popularity for applications in sonar sensing and excitation. A current challenge for many researchers is modelling the dynamic performance of these and other micro-mechanical devices to ascertain their performance and explain experimental observations reported. In this work, the performance simulation of a MEMS ultrasonic transducer array made from silicon nitride has been successfully carried out using CoventorWare package. The dynamic response of the entire transducer array was characterised, and the results were compared with theoretical predictions. Individual elements were found to vibrate with Bessel-like displacement patterns, and they were resonant at approximately 3 MHz, depending on thickness and lateral dimensions. The frequency shows a linear dependence around the common thickness of 2 μm. Peak displacement levels were examined as a function of frequency, DC bias voltage, and AC drive voltage. Accounting for fabrication variations, and uniformity variations across the wafer, the full array showed minimal variations in peak out-of-plane displacement levels across the device, and isolated elements that were over-responsive and under-responsive. Presently, the effect of observed variations across the array on the performance of the transducers and their radiated fields are being examined

  2. Features calibration of the dynamic force transducers

    Science.gov (United States)

    Sc., M. Yu Prilepko D.; Lysenko, V. G.

    2018-04-01

    The article discusses calibration methods of dynamic forces measuring instruments. The relevance of work is dictated by need to valid definition of the dynamic forces transducers metrological characteristics taking into account their intended application. The aim of this work is choice justification of calibration method, which provides the definition dynamic forces transducers metrological characteristics under simulation operating conditions for determining suitability for using in accordance with its purpose. The following tasks are solved: the mathematical model and the main measurements equation of calibration dynamic forces transducers by load weight, the main budget uncertainty components of calibration are defined. The new method of dynamic forces transducers calibration with use the reference converter “force-deformation” based on the calibrated elastic element and measurement of his deformation by a laser interferometer is offered. The mathematical model and the main measurements equation of the offered method is constructed. It is shown that use of calibration method based on measurements by the laser interferometer of calibrated elastic element deformations allows to exclude or to considerably reduce the uncertainty budget components inherent to method of load weight.

  3. Prostate Cancer FAQs

    Science.gov (United States)

    ... Fundraise for PCF: Many vs Cancer Contact Us Prostate Cancer FAQs Top 10 Things You Should Know About ... prostate cancer detected? What are the symptoms of prostate cancer? If the cancer is caught at its earliest ...

  4. Prostate Cancer Symptoms

    Science.gov (United States)

    ... Fundraise for PCF: Many vs Cancer Contact Us Prostate Cancer Symptoms and Signs Prostate Cancer Basics Risk Factors ... earlier. So what are the warning signs of prostate cancer? Unfortunately, there usually aren’t any early warning ...

  5. Prostate Cancer Foundation News

    Science.gov (United States)

    ... Finding a Doctor Treatment Options Side Effects Managing Prostate Cancer Treatment Related Side Effects Clinical Trials Patient Resources Guides Videos Prostate Cancer FAQs Information by Stage Newly Diagnosed with Prostate ...

  6. Prostate cancer - treatment

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000403.htm Prostate cancer - treatment To use the sharing features on this page, ... drugs is recommended. References National Cancer Institute. Prostate cancer treatment (PDQ): Stages of prostate cancer. Updated July 31, ...

  7. Prostate Cancer Screening

    Science.gov (United States)

    ... prostate. The prostate is a gland in the male reproductive system located just below the bladder (the organ that ... up part of semen . Enlarge Anatomy of the male reproductive and urinary systems, showing the prostate, testicles, bladder, and other organs. ...

  8. Biasing of Capacitive Micromachined Ultrasonic Transducers.

    Science.gov (United States)

    Caliano, Giosue; Matrone, Giulia; Savoia, Alessandro Stuart

    2017-02-01

    Capacitive micromachined ultrasonic transducers (CMUTs) represent an effective alternative to piezoelectric transducers for medical ultrasound imaging applications. They are microelectromechanical devices fabricated using silicon micromachining techniques, developed in the last two decades in many laboratories. The interest for this novel transducer technology relies on its full compatibility with standard integrated circuit technology that makes it possible to integrate on the same chip the transducers and the electronics, thus enabling the realization of extremely low-cost and high-performance devices, including both 1-D or 2-D arrays. Being capacitive transducers, CMUTs require a high bias voltage to be properly operated in pulse-echo imaging applications. The typical bias supply residual ripple of high-quality high-voltage (HV) generators is in the millivolt range, which is comparable with the amplitude of the received echo signals, and it is particularly difficult to minimize. The aim of this paper is to analyze the classical CMUT biasing circuits, highlighting the features of each one, and to propose two novel HV generator architectures optimized for CMUT biasing applications. The first circuit proposed is an ultralow-residual ripple (generator that uses an extremely stable sinusoidal power oscillator topology. The second circuit employs a commercially available integrated step-up converter characterized by a particularly efficient switching topology. The circuit is used to bias the CMUT by charging a buffer capacitor synchronously with the pulsing sequence, thus reducing the impact of the switching noise on the received echo signals. The small area of the circuit (about 1.5 cm 2 ) makes it possible to generate the bias voltage inside the probe, very close to the CMUT, making the proposed solution attractive for portable applications. Measurements and experiments are shown to demonstrate the effectiveness of the new approaches presented.

  9. Parameter sensitivity study of a Field II multilayer transducer model on a convex transducer

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2009-01-01

    A multilayer transducer model for predicting a transducer impulse response has in earlier works been developed and combined with the Field II software. This development was tested on current, voltage, and intensity measurements on piezoceramics discs (Bæk et al. IUS 2008) and a convex 128 element...... ultrasound imaging transducer (Bæk et al. ICU 2009). The model benefits from its 1D simplicity and hasshown to give an amplitude error around 1.7‐2 dB. However, any prediction of amplitude, phase, and attenuation of pulses relies on the accuracy of manufacturer supplied material characteristics, which may...... is a quantitative calibrated model for a complete ultrasound system. This includes a sensitivity study aspresented here.Statement of Contribution/MethodsThe study alters 35 different model parameters which describe a 128 element convex transducer from BK Medical Aps. The changes are within ±20 % of the values...

  10. Capacitive pressure transducer using flexible films. Junan film wo mochiita seiden yoryoshiki atsukaku transducer

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Y.; Tsuchida, N.; Imai, K. (Toyota Technological Institute, Aichi (Japan)); Fujita, K. (Nitto Denko Corp., Osaka (Japan)): Tsuboi, O. (Fujitsu Corp., Tokyo (Japan))

    1992-12-20

    This paper describes the design, manufacture, and evaluation of a capacitive pressure transducer made of polyimide films. The structure of a pressure transducer cell was first determined, and then, the deflection-stress and capacitance-load characteristics of the surface film were analyzed using finite element methods. For the practical stage of manufacture, a polyimide film was emboss processed and electrodes were deposited on the film to construct a pressure transducer cell to which a Schmidt-trigger detecting circuit was connected. As a consequence of the examination of operational characteristics of the cell, it was found that the actual relation between the deflection and load approximately agreed with the linear analyses, and that the capacitance depended with little hysteresis on the gap regardless of the native visco-elasticity of the film. Furthermore, small stick-slip vibration of a contact rubber surface was detected by the transducer to verify its high sensitivity. 17 refs., 18 figs.

  11. Prostatitis and male infertility.

    Science.gov (United States)

    Alshahrani, Saad; McGill, John; Agarwal, Ashok

    2013-11-01

    The prostate gland plays an important role in male reproduction. Inflammation of the prostate gland (prostatitis) is a common health problem affecting many young and middle aged men. Prostatitis is considered a correctable cause of male infertility, but the pathophysiology and appropriate treatment options of prostatitis in male infertility remain unclear. This literature review will focus on current data regarding prostatitis and its impact on male infertility. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Radiation-Induced Leiomyosarcoma of the Prostate after Brachytherapy for Prostatic Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Hiroto Horiguchi

    2014-08-01

    Full Text Available Radiation therapy (RTx has been employed as a curative therapy for prostatic adenocarcinoma. RTx-induced sarcomas (RISs are rare, late adverse events, representing less than 0.2% of all irradiated patients. RISs are more aggressive tumors than prostatic adenocarcinomas. Herein, we present a case with RTx-induced prostatic leiomyosarcoma after permanent brachytherapy for prostatic adenocarcinoma. A 69-year-old male presented with dysuria and gross hematuria. Six years previously, he had been diagnosed with localized prostate cancer and was treated by permanent brachytherapy. Urethroscopy showed stenosis by a tumor at the prostate. Transurethral prostatectomy was performed for a diagnosis. Based on pathological findings, the diagnosis was leiomyosarcoma of the prostate. He was treated with three cycles of neoadjuvant chemotherapy (CTx that consisted of doxorubicin and ifosfamide (AI, followed by a prostatocystectomy with intrapelvic lymphadenectomy. The tumor extended from the prostate and infiltrated the bladder wall and serosa with lymphatic and venous invasion. The surgical margin was negative, and no residual prostatic adenocarcinoma was observed. The proportion of necrotic tumor cells by neoadjuvant CTx was around 50%. Subsequently, adjuvant CTx was offered, but the patient chose a follow-up without CTx. Local recurrence and lung metastasis were detected by computed tomography 3 months after the surgery. He was treated again with AI. However, CTx was not effective and he died 6 months after the operation. In conclusion, an effective treatment strategy for prostatic sarcoma should be developed in the near future, although the clinical feature of prostatic sarcoma remains unclear due to its rare incidence.

  13. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... in which a needle is used to sample cells (tissue) from an abnormal area in the prostate gland for later laboratory testing. ... Do you have a personal ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of Prostate ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of ...

  16. Prostate Ultrasound

    Medline Plus

    Full Text Available ... symptoms such as difficulty urinating or an elevated blood test result. It’s also used to investigate a nodule ... exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time ...

  17. Prostate Ultrasound

    Medline Plus

    Full Text Available ... exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide procedures such as needle biopsies , in which a needle is used to sample cells (tissue) from an abnormal area in the ...

  18. Prostate brachytherapy - discharge

    Science.gov (United States)

    Implant therapy - prostate cancer - discharge; Radioactive seed placement - discharge ... You had a procedure called brachytherapy to treat prostate cancer. Your treatment lasted 30 minutes or more, ...

  19. Microhydraulic transducer technology for actuation and power generation

    Science.gov (United States)

    Hagood, Nesbitt W.; Roberts, David C.; Saggere, Laxminarayana; Breuer, Kenneth S.; Chen, Kuo-Shen; Carretero, Jorge A.; Li, Hanqing; Mlcak, Richard; Pulitzer, Seward W.; Schmidt, Martin A.; Spearing, S. Mark; Su, Yu-Hsuan

    2000-06-01

    The paper introduces a novel transducer technology, called the solid-state micro-hydraulic transducer, currently under development at MIT. The new technology is enabled through integration of micromachining technology, piezoelectrics, and microhydraulic concepts. These micro-hydraulic transducers are capable of bi-directional electromechanical energy conversion, i.e., they can operate as both an actuator that supplies high mechanical force in response to electrical input and an energy generator that transduces electrical energy from mechanical energy in the environment. These transducers are capable of transducing energy at very high specific power output in the order of 1 kW/kg, and thus, they have the potential to enable many novel applications. The concept, the design, and the potential applications of the transducers are presented. Present efforts towards the development of these transducers, and the challenges involved therein, are also discussed.

  20. Combination immunotherapy with prostate GVAX and ipilimumab: safety and toxicity.

    Science.gov (United States)

    Karan, Dev; Van Veldhuizen, Peter

    2012-06-01

    Evaluation of: van den Eertwegh AJ, Versluis J, van den Berg HP et al. Combined immunotherapy with granulocyte-macrophage colony-stimulating factor-transduced allogeneic prostate cancer cells and ipilimumab in patients with metastatic castration-resistant prostate cancer: a Phase 1 dose-escalation trial. Lancet Oncol. 13(5), 509 – 517 (2012). A significant interest in the development of therapeutic cancer vaccines over the last decade has led to an improvement in overall survival of cancer patients in several clinical trials. As a result, two active immunotherapy agents, sipuleucel-T and ipilimumab, have been approved by the US FDA for the treatment of prostate cancer and melanoma, respectively. GVAX(®) cellular vaccine (Cell Genesysis, Inc., CA, USA) is another active immunotherapy agent targeting prostate cancer and it has been well studied in various clinical trials. The current publication, by van den Eertwegh et al., demonstrated a combination of two active immunotherapy approaches, using GVAX and ipilimumab for the treatment of metastatic castration-resistant prostate cancer. While GVAX is designed to amplify the antitumor response specific to prostate cancer cells, ipilimumab contributes to T-cell activation. Thus, the authors presented the possibility of augmenting antitumor T-cell activity in two different ways. They successfully demonstrated a tolerable dose and safety profile of ipilimumab in combination with GVAX for patients with metastatic castration-resistant prostate cancer. However, further studies of such immunotherapy combinations and detailed analysis of their immunological effects are needed to observe clinical benefit.

  1. Radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Krause, S.; Herfarth, K.

    2011-01-01

    With the development of modern radiation techniques, such as intensity-modulated radiotherapy (IMRT), a dose escalation in the definitive radiotherapy of prostate cancer and a consecutive improvement in biochemical recurrence-free survival (BFS) could be achieved. Among others, investigators at the Memorial Sloan-Kettering Cancer Center (MSKCC) saw 5-year BFS rates of up to 98%. A further gain in effectiveness and safety is expected of hypofractionation schedules, as suggested by data published by Kupelian et al., who saw a low 5-year rate of grade ≥2 rectal side-effects of 4.5%. However, randomized studies are just beginning to mature. Patients with intermediate or high-risk tumors should receive neoadjuvant (NHT) and adjuvant (AHT) androgen deprivation. Bolla et al. could show an increase in 5-year overall survival from 62-78%. The inclusion of the whole pelvis in the treatment field (WPRT) is still controversial. The RTOG 94-13 study showed a significant advantage in disease-free survival after 60 months but long-term data did not yield significant differences between WPRT and irradiation of the prostate alone. The German Society of Urology strongly recommends adjuvant radiotherapy of the prostate bed for pT3 N0 tumors with positive margins. In a pT3 N0 R0 or pT2 N0 R+ situation, adjuvant radiotherapy should at least be considered. So far, no randomized data on NHT and AHT have been published, so androgen deprivation remains an individual decision in the postoperative setting. In a retrospective analysis Spiotto et al. reported a positive effect for adjuvant WPRT and biochemical control. This article summarizes the essential publications on definitive and adjuvant radiotherapy and discusses the additional use of androgen deprivation and WPRT. (orig.) [de

  2. Epidemiology of prostatitis

    Science.gov (United States)

    Krieger, John N.; Lee, Shaun Wen Huey; Jeon, Jeonseong; Cheah, Phaik Yeong; Liong, Men Long; Riley, Donald E.

    2008-01-01

    Background Prostatitis describes a combination of infectious diseases (acute and chronic bacterial prostatitis), chronic pelvic pain syndrome, and asymptomatic inflammation. Materials and methods We employed evidence-based methods to review the epidemiology of prostatitis syndromes. Results The prevalence of prostatitis symptoms could be compared in five studies surveying 10 617 men. Overall, 873 participants met various criteria for prostatitis, representing an overall rate of 8.2%, with prevalence ranging from 2.2 to 9.7%. A history of sexually transmitted diseases was associated with an increased risk for prostatitis symptoms. Men reporting a history of prostatitis symptoms had a substantially increased rate of benign prostatic hyperplasia, lower urinary tract symptoms and prostate cancer. In one study, the incidence of physician-diagnosed prostatitis was 4.9 cases per 1000 person-years. Two studies suggest that about one-third of men reporting prostatitis symptoms had resolution after 1 year. Patients with previous episodes and more severe symptoms are at higher risk for chronic pelvic pain. Discussion The prevalence of prostatitis symptoms is high, comparable to rates of ischamic heart disease and diabetes. Clinical evaluation appears necessary to verify that prostatitis is responsible for patients’ symptoms. Prostatitis symptoms may increase a man’s risk for benign prostate hypertrophy, lower urinary tract symptoms and prostate cancer. We need to define natural history and consequences of prostatitis, develop better algorithms for diagnosis and treatment, and develop strategies for prevention. PMID:18164907

  3. Dissipation in vibrating superleak second sound transducers

    International Nuclear Information System (INIS)

    Giordano, N.

    1985-01-01

    We have performed an experimental study of the generation and detection of second sound in 4 He using vibrating superleak second sound transducers. At temperatures well below T/sub lambda/ and for low driving amplitudes, the magnitude of the generated second sound wave is proportional to the drive amplitude. However, near T/sub lambda/ and for high drive amplitudes this is no longer the case--instead, the second sound amplitude saturates. In this regime we also find that overtones of the drive frequency are generated. Our results suggest that this behavior is due to critical velocity effects in the pores of the superleak in the generator transducer. This type of measurement may prove to be a useful way in which to study critical velocity effects in confined geometries

  4. Ultrasonic transducer design for uniform insonation

    International Nuclear Information System (INIS)

    Harrison, G.H.; Balcer-Kubiczek, E.K.; McCulloch, D.

    1984-01-01

    Techniques used in transducer development for acoustical imaging have been evaluated for the purpose of producing broad, uniform ultrasonic fields from planar radiators. Such fields should be useful in hyperthermia, physical therapy, and ultrasonic bioeffects studies. Fourier inversion of the circ function yielded a source velocity distribution proportional to (P/r) exp ((-ik/2Z) (2Z/sup 2/+r/sup 2/)) J/sub 1/(krP/Z), where r is the radial source coordinate, k is the wave number, and P is the desired radius of uniform insonation at a depth Z in water. This source distribution can be truncated without significantly degrading the solution. A simpler solution consists of exponentially shading the edge of an otherwise uniformly excited disk transducer. This approach was successfully approximated experimentally

  5. Cymbal and BB underwater transducers and arrays

    Energy Technology Data Exchange (ETDEWEB)

    Newnham, R.E.; Zhang, J.; Alkoy, S.; Meyer, R.; Hughes, W.J.; Hladky-Hennion, A.C.; Cochran, J.; Markley, D. [Materials Research Laboratory, Penn State University, University Park, PA 16802 (United States)

    2002-09-01

    The cymbal is a miniaturized class V flextensional transducer that was developed for use as a shallow water sound projector and receiver. Single elements are characterized by high Q, low efficiency, and medium power output capability. Its low cost and thin profile allow the transducer to be assembled into large flexible arrays. Efforts were made to model both single elements and arrays using the ATILA code and the integral equation formulation (EQI).Millimeter size microprobe hydrophones (BBs) have been designed and fabricated from miniature piezoelectric hollow ceramic spheres for underwater applications such as mapping acoustic fields of projectors, and flow noise sensors for complex underwater structures. Green spheres are prepared from soft lead zirconate titanate powders using a coaxial nozzle slurry process. A compact hydrophone with a radially-poled sphere is investigated using inside and outside electrodes. Characterization of these hydrophones is done through measurement of hydrostatic piezoelectric charge coefficients, free field voltage sensitivities and directivity beam patterns. (orig.)

  6. ACT listening test[Active transducers

    Energy Technology Data Exchange (ETDEWEB)

    Agerkvist, F. [Oersted, DTU, Kgs. Lyngby (Denmark); Fenger, L.M. [Bang and Olufsen ICEPower a/s, Kgs. Lyngby (Denmark)

    2004-07-01

    This report describes the series of subjective listening that was performed in order to test the subjective quality of the integration of amplifier and loudspeaker developed in the Active transducer project. The project is a fundamental study of the loss mechanisms in loudspeakers and amplifiers. The project has resulted in new switch mode amplifier topologies with very high audio performance at a very low cost. (BA)

  7. Transducer Analysis and ATILA++ Model Development

    Science.gov (United States)

    2016-10-10

    the behavior of single crystal piezoelectric devices. OBJECTIVES To carry out this effort, a team consisting of ISEN...recording the vibration displacements on the opposite surface of the sample with a second receiving transducer. A software program is used to curve-fit the ...analysis in a loop until the desired quality of fit is achieved. 12 The technique has, in the past, been successfully used to determine

  8. Passive Mode Carbon Nanotube Underwater Acoustic Transducer

    Science.gov (United States)

    2016-09-20

    Acoustical transducer arrays can reflect a sound signal in reverse to the sender which can be used for echo location devices. [0008] In Jiang...States Patent No. 8,494,187) a sound wave generator is disclosed which includes a carbon nanotube structure and an insulating reinforcement structure... acoustic device that includes an electrode layer and a sound wave generator. The sound wave generator is disposed on a surface of the electrode

  9. Thermoelectric Transducer Using Bio Nano Process

    Science.gov (United States)

    2015-08-01

    Ferritin; Thermal Transducer; Nanoparticle; Ammonium acetate; Separation distance; Debye length . ABSTRACT: As an application to thermos...condition of 10 mM concentration, the Debye length of ferritin is shorter than 3 nm 40 . Comparing it with the DLS results (Fig. 3), the Debye length is...modified PEGs will obstruct additional modification. This effect should strengthen when PEG length becomes longer which means the utilization of

  10. Cooling Acoustic Transducer with Heat Pipes

    Science.gov (United States)

    2009-07-29

    a heat sink. [0009] In Kan et al (United States Patent No. 6,528,909), a spindle motor assembly is disclosed which has a shaft with an integral...heat pipe. The shaft with the integral heat pipe improves the thermal conductively of the shaft and the spindle motor assembly. The shaft includes...Description of the Prior Art [0004] It is known in the art that transducers, designed to project acoustic power, are often limited by the build

  11. Turbine transducer developed for adverse conditions

    International Nuclear Information System (INIS)

    Cooper, D.R.; Edson, J.L.

    1982-01-01

    This paper reviews the latest developments that the Idaho National Engineering Laboratory (INEL) has made on a turbine transducer used in measurement of two-phase flow. It is operated in a modular configuration with a drag transducer to provide mass flow data. Current configurations allow its use in single modules or in multiples to provide flow profile information. The turbine can also provide mass flow data when used with associated instrumentation such as a densitometer. The transducer, which is the product of long investigations and test series, is subject to high vibration loading and high temperatures as well as a borated liquid environment; flow conditions range from all liquid to all steam and from ambient temperatures to over 600 0 F at pressures up to 2200 psi. Graphite bearing and carbide shaft materials were selected to provide corrosion resistance along with mechanical integrity, and resistance to wear. The new turbine design has met all operational requirements in actual use and in extended lifetime tests

  12. Stress Sensors and Signal Transducers in Cyanobacteria

    Science.gov (United States)

    Los, Dmitry A.; Zorina, Anna; Sinetova, Maria; Kryazhov, Sergey; Mironov, Kirill; Zinchenko, Vladislav V.

    2010-01-01

    In living cells, the perception of environmental stress and the subsequent transduction of stress signals are primary events in the acclimation to changes in the environment. Some molecular sensors and transducers of environmental stress cannot be identified by traditional and conventional methods. Based on genomic information, a systematic approach has been applied to the solution of this problem in cyanobacteria, involving mutagenesis of potential sensors and signal transducers in combination with DNA microarray analyses for the genome-wide expression of genes. Forty-five genes for the histidine kinases (Hiks), 12 genes for serine-threonine protein kinases (Spks), 42 genes for response regulators (Rres), seven genes for RNA polymerase sigma factors, and nearly 70 genes for transcription factors have been successfully inactivated by targeted mutagenesis in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Screening of mutant libraries by genome-wide DNA microarray analysis under various stress and non-stress conditions has allowed identification of proteins that perceive and transduce signals of environmental stress. Here we summarize recent progress in the identification of sensory and regulatory systems, including Hiks, Rres, Spks, sigma factors, transcription factors, and the role of genomic DNA supercoiling in the regulation of the responses of cyanobacterial cells to various types of stress. PMID:22294932

  13. Virus Delivery of CRISPR Guides to the Murine Prostate for Gene Alteration.

    Science.gov (United States)

    Riedel, Maria; Berthelsen, Martin F; Bakiri, Latifa; Wagner, Erwin F; Thomsen, Martin K

    2018-04-27

    With an increasing incidence of prostate cancer, identification of new tumor drivers or modulators is crucial. Genetically engineered mouse models (GEMM) for prostate cancer are hampered by tumor heterogeneity and its complex microevolution dynamics. Traditional prostate cancer mouse models include, amongst others, germline and conditional knockouts, transgenic expression of oncogenes, and xenograft models. Generation of de novo mutations in these models is complex, time-consuming, and costly. In addition, most of traditional models target the majority of the prostate epithelium, whereas human prostate cancer is well known to evolve as an isolated event in only a small subset of cells. Valuable models need to simulate not only prostate cancer initiation, but also progression to advanced disease. Here we describe a method to target a few cells in the prostate epithelium by transducing cells by viral particles. The delivery of an engineered virus to the murine prostate allows alteration of gene expression in the prostate epithelia. Virus type and quantity will hereby define the number of targeted cells for gene alteration by transducing a few cells for cancer initiation and many cells for gene therapy. Through surgery-based injection in the anterior lobe, distal from the urinary track, the tumor in this model can expand without impairing the urinary function of the animal. Furthermore, by targeting only a subset of prostate epithelial cells the technique enables clonal expansion of the tumor, and therefore mimics human tumor initiation, progression, as well as invasion through the basal membrane. This novel technique provides a powerful prostate cancer model with improved physiological relevance. Animal suffering is limited, and since no additional breeding is required, overall animal count is reduced. At the same time, analysis of new candidate genes and pathways is accelerated, which in turn is more cost efficient.

  14. Ultrasonic properties of all-printed piezoelectric polymer transducers

    Science.gov (United States)

    Wagle, Sanat; Decharat, Adit; Bodö, Peter; Melandsø, Frank

    2013-12-01

    The ability of producing ultrasonic transducers from screen-printing has been explored experimentally, through printing and characterization of a large number of transducers. In an all-printed test design, 124 transducers with four different electrode sizes ranging from 1 to 4.9 mm2, were printed layer-by-layer on a high performance polyethyleneimine polymer. Inks from ferroelectric and conductive polymers were applied to the active part of a transducer, to provide a good acoustical match between the individual layers. Ultrasonic characterizations of the transducers done by two independent methods provided a broad-banded frequency response with a maximum response around 100 MHz.

  15. Linear Array Ultrasonic Transducers: Sensitivity and Resolution Study

    International Nuclear Information System (INIS)

    Kramb, V.A.

    2005-01-01

    The University of Dayton Research Institute (UDRI) under contract by the US Air Force has designed and integrated a fully automated inspection system for the inspection of turbine engines that incorporates linear phased array ultrasonic transducers. Phased array transducers have been successfully implemented into weld and turbine blade root inspections where the defect types are well known and characterized. Embedded defects in aerospace turbine engine components are less well defined, however. In order to determine the applicability of linear arrays to aerospace inspections the sensitivity of array transducers to embedded defects in engine materials must be characterized. In addition, the implementation of array transducers into legacy inspection procedures must take into account any differences in sensitivity between the array transducer and that of the single element transducer currently used. This paper discusses preliminary results in a study that compares the sensitivity of linear array and conventional single element transducers to synthetic hard alpha defects in a titanium alloy

  16. Investigation of power and frequency for 3D conformal MRI-controlled transurethral ultrasound therapy with a dual frequency multi-element transducer.

    Science.gov (United States)

    N'djin, William Apoutou; Burtnyk, Mathieu; Bronskill, Michael; Chopra, Rajiv

    2012-01-01

    Transurethral ultrasound therapy uses real-time magnetic resonance (MR) temperature feedback to enable the 3D control of thermal therapy accurately in a region within the prostate. Previous canine studies showed the feasibility of this method in vivo. The aim of this study was to reduce the procedure time, while maintaining targeting accuracy, by investigating new combinations of treatment parameters. Simulations and validation experiments in gel phantoms were used, with a collection of nine 3D realistic target prostate boundaries obtained from previous preclinical studies, where multi-slice MR images were acquired with the transurethral device in place. Acoustic power and rotation rate were varied based on temperature feedback at the prostate boundary. Maximum acoustic power and rotation rate were optimised interdependently, as a function of prostate radius and transducer operating frequency. The concept of dual frequency transducers was studied, using the fundamental frequency or the third harmonic component depending on the prostate radius. Numerical modelling enabled assessment of the effects of several acoustic parameters on treatment outcomes. The range of treatable prostate radii extended with increasing power, and tended to narrow with decreasing frequency. Reducing the frequency from 8 MHz to 4 MHz or increasing the surface acoustic power from 10 to 20 W/cm(2) led to treatment times shorter by up to 50% under appropriate conditions. A dual frequency configuration of 4/12 MHz with 20 W/cm(2) ultrasound intensity exposure can treat entire prostates up to 40 cm(3) in volume within 30 min. The interdependence between power and frequency may, however, require integrating multi-parametric functions in the controller for future optimisations.

  17. A feasibility study of MR elastography in the diagnosis of prostate cancer at 3.0T

    Energy Technology Data Exchange (ETDEWEB)

    Li, Saying; Chen, Min; Wang, Wenchao; Zhao, Weifeng; Zhou, Cheng (Dept. of Radiology, Beijing Hospital, Beijing (China)), e-mail: chenmin62@yahoo.com; Wang, Jianye (Dept. of Urology, Beijing Hospital, Beijing (China)); Zhao, Xuna (Philips Medical System (China))

    2011-04-15

    Background: MR elastography is a new imaging tool capable of non-invasively assessing the viscoelastic properties of tissues. The clinical application of MR elastography in the diagnosis of prostate cancer remains to be elucidated. Purpose: To investigate the feasibility of MR elastography in the diagnosis of prostate cancer at 3.0T, and to assess the elasticity and viscosity of prostate cancer and benign prostatic disease. Material and Methods: Eight patients (63 +- 7.25 years old) with 12 foci of prostate cancer and 10 patients (59 +- 3.25 years old) with 14 foci of prostatitis in the peripheral zone were evaluated by MRE. Ten healthy volunteers (41 +- 4.32 years old) with 18 ROIs in the peripheral zone of the prostate were also assessed with MR elastography as a control group. The results were confirmed by histopathological findings. All examinations were performed on a 3.0T Philips Achieva scanner. MRE was implemented by transmitting low-frequency longitudinal mechanical waves of 100Hz into the prostate with a transducer placed above the pubic bones. The phase images were reconstructed to acquire viscoelastic mapping. T-test was used to compare the mean elasticity and viscosity of prostate cancer and prostatitis. A comparison of prostate cancer and healthy prostate tissue in elasticity was also evaluated. The correlation of elasticity and Gleason scores between prostate cancer and prostatitis were retrospectively analyzed with Pearson Correlation. Results: The mean elasticity and viscosity were significantly higher in the lesions with prostate cancer (6.55 +- 0.47 kPa, 6.56 +- 0.99 Pa.s, respectively) than in regions with prostatitis (1.99 +- 0.66 kPa, 2.13 +- 0.21 Pa.s). The difference between prostate cancer and prostatitis was statistically significant (t = 19.392, p < 0.01; t = 16.372, p < 0.01). The elasticity and viscosity of the healthy peripheral zone of prostate were 2.26 +- 0.45 kPa, 2.38 +- 0.54 Pa.s, respectively. There also was significant

  18. A feasibility study of MR elastography in the diagnosis of prostate cancer at 3.0T

    International Nuclear Information System (INIS)

    Li, Saying; Chen, Min; Wang, Wenchao; Zhao, Weifeng; Zhou, Cheng; Wang, Jianye; Zhao, Xuna

    2011-01-01

    Background: MR elastography is a new imaging tool capable of non-invasively assessing the viscoelastic properties of tissues. The clinical application of MR elastography in the diagnosis of prostate cancer remains to be elucidated. Purpose: To investigate the feasibility of MR elastography in the diagnosis of prostate cancer at 3.0T, and to assess the elasticity and viscosity of prostate cancer and benign prostatic disease. Material and Methods: Eight patients (63 ± 7.25 years old) with 12 foci of prostate cancer and 10 patients (59 ± 3.25 years old) with 14 foci of prostatitis in the peripheral zone were evaluated by MRE. Ten healthy volunteers (41 ± 4.32 years old) with 18 ROIs in the peripheral zone of the prostate were also assessed with MR elastography as a control group. The results were confirmed by histopathological findings. All examinations were performed on a 3.0T Philips Achieva scanner. MRE was implemented by transmitting low-frequency longitudinal mechanical waves of 100Hz into the prostate with a transducer placed above the pubic bones. The phase images were reconstructed to acquire viscoelastic mapping. T-test was used to compare the mean elasticity and viscosity of prostate cancer and prostatitis. A comparison of prostate cancer and healthy prostate tissue in elasticity was also evaluated. The correlation of elasticity and Gleason scores between prostate cancer and prostatitis were retrospectively analyzed with Pearson Correlation. Results: The mean elasticity and viscosity were significantly higher in the lesions with prostate cancer (6.55 ± 0.47 kPa, 6.56 ± 0.99 Pa.s, respectively) than in regions with prostatitis (1.99 ± 0.66 kPa, 2.13 ± 0.21 Pa.s). The difference between prostate cancer and prostatitis was statistically significant (t = 19.392, p < 0.01; t = 16.372, p < 0.01). The elasticity and viscosity of the healthy peripheral zone of prostate were 2.26 ± 0.45 kPa, 2.38 ± 0.54 Pa.s, respectively. There also was significant

  19. Significance of prostatic weight in prostatism

    DEFF Research Database (Denmark)

    Jensen, K M; Bruskewitz, R C; Iversen, P

    1983-01-01

    In addition to routine evaluation, 68 patients with prostatism underwent blinded urodynamic testing prior to transurethral prostatectomy and were reexamined symptomatologically and urodynamically at 3 and 12 months after surgery to determine if prostatic weight could predict postoperative outcome....... Resected prostatic weight correlated with estimated weight at cystoscopy and with obstructive symptoms, but not with urodynamic variables of infravesical obstruction. Patients with small prostates improved symptomatologically to the same degree as patients with larger glands, although they did not improve...... to the same degree urodynamically. Prostatic weight, therefore, could not be used to predict the outcome of transurethral surgery....

  20. Local high voltage radiotherapy with curative intent for prostatic carcinoma

    International Nuclear Information System (INIS)

    Jacobi, G.H.; Kurth, K.H.; Hohenfellner, R.

    1979-01-01

    In a 10-year interval 179 patients with prostatic carcinoma were treated by cobalt-60 teletherapy (7600 R). A selected group of 47 patients with localized disease and irradiated with curative intent had serial prostatic biopsies and were analized after a minimum follow-up of 1 year. Biopsies of half of the patients rendered definitively negative, on an average 14 months after radiotherapy. 8 patients with initial negative biopsy changed to positive secondarily. In one third of the patients histological conversion was missed, considered as radiation persister. Persistent carcinoma were of predominant low grade. 5 patients developed distant metastases 30 months after irradiation on an average. These patients had persistent positive tissue studies. Over all cumulative 5-years survival was 89%. In patients with prostatic carcinoma and local high voltage radiotherapy with curative intent (stage A through C) serial prostatic biopsies to document therapy effect seen mandatory. (orig.) 891 AJ/orig. 892 BRE [de

  1. Na, K-ATPase as signaling transducer

    OpenAIRE

    Li, Juan

    2007-01-01

    It is now generally agreed that Na,K-ATPase (NKA), in addition to its role in the maintenance of Na+ and K+ gradients across the cell membrane, is a signal transducer. Our group has identified a novel signaling pathway where NKA interact with IP3R to form a signaling microdomain. Ouabain, a specific ligand of NKA, activates this pathway, triggers slow Ca2+ oscillations and activates NF-κB. In current study, the molecular mechanisms and some important downstream effects of NK...

  2. Long term results in radiotherapy of prostatic cancer

    International Nuclear Information System (INIS)

    Bagshaw, M.A.; Ray, G.R.; Cox, R.S.

    1987-01-01

    Discounting skin cancer, prostatic cancer remains second only to lung cancer in incidence in the United States. Colon Cancer is a close third. The incidence of lung cancer has started to decline slightly in the male, while prostatic cancer continues to increase, no doubt related to the aging of the population. Radiation therapy was first used in the treatment of prostatic cancer in the United States about 1915, having been introduced as intracavitary radium treatments by the American urologist, Hugh Young. External beam irradiation was used in the 1930's, but mostly for palliation of ureteral and vascular obstruction. Definitive use was first described by other investigators in the 1940's' however, attention changed to hormonal manipulation following Huggin's discovery of the dependency of prostate cancer on male hormone. Improved radiation therapy sources were invented, such as Cobalt 60 units, linear accelerators and betatrons, stimulated a reinvestigation of the definitive use of radiation therapy to prostate cancer in the 1950's. According to the current American College of Surgeon's survey of patterns of care of patients with prostate cancer, the use of external beam irradiation for the treatment of prostatic cancer has doubled in the United States during the past decade; however, apparently in Europe, hormone deprivation remains the therapeutic standard

  3. Nd : YAG surgical laser effects in canine prostate tissue: temperature and damage distribution

    NARCIS (Netherlands)

    van Nimwegen, S. A.; L'Eplattenier, H. F.; Rem, A. I.; van der Lugt, J. J.; Kirpensteijn, J.

    2009-01-01

    An in vitro model was used to predict short-term, laser-induced, thermal damage in canine prostate tissue. Canine prostate tissue samples were equipped with thermocouple probes to measure tissue temperature at 3, 6, 9 and 12 mm depths. The tissue surface was irradiated with a Nd:YAG laser in contact

  4. Manufacturing technologies for ultrasonic transducers in a broad frequency range

    OpenAIRE

    Gebhardt, Sylvia; Hohlfeld, Kai; Günther, Paul; Neubert, Holger

    2018-01-01

    According to the application field, working frequency of ultrasonic transducers needs to be tailored to a certain value. Low frequency ultrasonic transducers with working frequencies of 1 kHz to 1 MHz are especially interesting for sonar applications, whereas high frequency ultrasonic transducers with working frequencies higher than 15 MHz are favorable for high-resolution imaging in biomedical and non-destructive evaluation. Conventional non-destructive testing devices and clinical ultrasoun...

  5. Prostatic sarcoma after treatment of rectal cancer

    Directory of Open Access Journals (Sweden)

    Hill Andrew G

    2007-07-01

    Full Text Available Abstract Background The relationship between radiation exposure for treatment of cancer and occurrence of a second primary cancer at the irradiated site is well known. This phenomenon is however rare in prostate. Case presentation A 75-year-old farmer was treated for rectal cancer with preoperative 45 Gy of radiotherapy and abdominoperineal resection. Four years later he developed symptoms of bladder outlet obstruction and acute urinary retention. He underwent a transurethral resection of the prostate. Histological examination of the removed prostate tissue and immunohistochemistry revealed it to be a poorly differentiated sarcoma. Conclusion We believe this to be the first reported case of radiation-induced sarcoma following radiotherapy treatment for rectal cancer. Since radiotherapy plays a pivotal role in the contemporary treatment of rectal adenocarcinoma, it is relevant to be aware of the potential long-term carcinogenic complications of radiotherapy of the pelvis.

  6. High Temperature Ultrasonic Transducer for Real-time Inspection

    Science.gov (United States)

    Amini, Mohammad Hossein; Sinclair, Anthony N.; Coyle, Thomas W.

    A broadband ultrasonic transducer with a novel porous ceramic backing layer is introduced to operate at 700 °C. 36° Y-cut lithium niobate (LiNbO3) single crystal was selected for the piezoelectric element. By appropriate choice of constituent materials, porosity and pore size, the acoustic impedance and attenuation of a zirconia-based backing layer were optimized. An active brazing alloy with high temperature and chemical stability was selected to bond the transducer layers together. Prototype transducers have been tested at temperatures up to 700 °C. The experiments confirmed that transducer integrity was maintained.

  7. Granulomatous prostatitis - an infrequent diagnosis

    Directory of Open Access Journals (Sweden)

    RPS Punia

    2002-01-01

    Full Text Available Granulomatous prostatitis is a rare disorder of pros-tate. We encountered 10 cases of′grmudomatous prosta-titis consisting of 5 cases of non-specific granulomatous prostatitis, 2 cases of xanthogranulomatous prostatitis, I case of tuberculous prostatitis, I case of malakoplakia prostate and I case of granulomatous prostatitis associ-ated with adenocarcinoma prostate. The diagnosis was made by histopathologic examination of trucut biopsy, TURP chips or retropubic prostatectomy specimen. In all the cases, granulomatous prostatitis was an incidental find-ing.

  8. Radiation therapy for prostatic cancer

    International Nuclear Information System (INIS)

    Kimura, Akira; Minowada, Shigeru; Tomoishi, Junzo; Kinoshita, Kenji; Matsuda, Tadayoshi

    1983-01-01

    A conformation radiotherapy system with collimators, whose openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator, has been developed for routine use in our hospital. Forty-four patients underwent radiation therapy, including this particular modality of radiotherapy, for prostatic cancer during the period of July 1976 through December 1981. Eight patients were classified as stage A, 10 stage B, 10 stage C, and 16 as stage D. Twenty-nine patients underwent conformation radiotherapy, two rotation radiotherapy, eight 2-port opposing technique radiotherapy, one 4-field radiotherapy, and four underwent a combination of 2-port opposing technique and conformation radiotherapy. Transient mild side effects such as diarrhea occurred in seven cases, while severe side effects such as rectal stricture or contracted bladder occurred in three cases. The latter occurred only in one case among 29 of conformation radiotherapy and in two among eight of 2-port opposing technique radiotherapy. The results of the treatment of short intervals in stage B, C, and D are as follows: prostatic size was reduced in 26 cases among 36, serum acid phosphatase level was reduced in 15 among 18 who had showed high acid phosphatase levels before treatment, although almost all cases underwent simultaneous hormonal therapy. The effects of radiotherapy alone were verified in two cases of stage B in which radiotherapy preceded hormonal therapy. Prostatic size and serum acid phosphatase level were reduced by radiotherapy alone. (author)

  9. Cancer Patient T Cells Genetically Targeted to Prostate-Specific Membrane Antigen Specifically Lyse Prostate Cancer Cells and Release Cytokines in Response to Prostate-Specific Membrane Antigen

    Directory of Open Access Journals (Sweden)

    Michael C. Gong

    1999-06-01

    Full Text Available The expression of immunoglobulin-based artificial receptors in normal T lymphocytes provides a means to target lymphocytes to cell surface antigens independently of major histocompatibility complex restriction. Such artificial receptors have been previously shown to confer antigen-specific tumoricidal properties in murine T cells. We constructed a novel ζ chain fusion receptor specific for prostate-specific membrane antigen (PSMA termed Pz-1. PSMA is a cell-surface glycoprotein expressed on prostate cancer cells and the neovascular endothelium of multiple carcinomas. We show that primary T cells harvested from five of five patients with different stages of prostate cancer and transduced with the Pz-1 receptor readily lyse prostate cancer cells. Having established a culture system using fibroblasts that express PSMA, we next show that T cells expressing the Pz-1 receptor release cytokines in response to cell-bound PSMA. Furthermore, we show that the cytokine release is greatly augmented by B7.1-mediated costimulation. Thus, our findings support the feasibility of adoptive cell therapy by using genetically engineered T cells in prostate cancer patients and suggest that both CD4+ and CD8+ T lymphocyte functions can be synergistically targeted against tumor cells.

  10. Prostate cancer staging

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000397.htm Prostate cancer staging To use the sharing features on this ... trials you may be able to join How Prostate Cancer Staging is Done Initial staging is based on ...

  11. Prostate Cancer Screening

    Science.gov (United States)

    ... treat. There is no standard screening test for prostate cancer. Researchers are studying different tests to find those ... PSA level may be high if you have prostate cancer. It can also be high if you have ...

  12. Prostate radiation - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000399.htm Prostate radiation - discharge To use the sharing features on ... keeping or getting an erection may occur after prostate radiation therapy. You may not notice this problem ...

  13. Enlarged prostate - after care

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000398.htm Enlarged prostate - after care To use the sharing features on this page, please enable JavaScript. The prostate is a gland that produces the fluid that ...

  14. Cryotherapy for prostate cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000907.htm Cryotherapy for prostate cancer To use the sharing features ... first treatment for prostate cancer. What Happens During Cryotherapy Before the procedure, you will be given medicine ...

  15. Prostate cancer in Denmark

    DEFF Research Database (Denmark)

    Brasso, K; Friis, S; Kjaer, S K

    1998-01-01

    To review the trends in prostate cancer (PC) incidence and mortality rates in Denmark during a 50-year period.......To review the trends in prostate cancer (PC) incidence and mortality rates in Denmark during a 50-year period....

  16. Prostate resection - minimally invasive

    Science.gov (United States)

    ... thermotherapy; TUMT; Urolift; BPH - resection; Benign prostatic hyperplasia (hypertrophy) - resection; Prostate - enlarged - resection ... passing an instrument through the opening in your penis (meatus). You will be given general anesthesia (asleep ...

  17. Smooth driving of Moessbauer electromechanical transducers

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, A., E-mail: veiga@fisica.unlp.edu.ar; Mayosky, M. A. [Universidad Nacional de La Plata, Facultad de Ingenieria (Argentina); Martinez, N.; Mendoza Zelis, P.; Pasquevich, G. A.; Sanchez, F. H. [Instituto de Fisica La Plata, CONICET (Argentina)

    2011-11-15

    Quality of Moessbauer spectra is strongly related to the performance of source velocity modulator. Traditional electromechanical driving techniques demand hard-edged square or triangular velocity waveforms that introduce long settling times and demand careful driver tuning. For this work, the behavior of commercial velocity transducers and drive units was studied under different working conditions. Different velocity reference waveforms in constant-acceleration, constant-velocity and programmable-velocity techniques were tested. Significant improvement in spectrometer efficiency and accuracy was achieved by replacing triangular and square hard edges with continuous smooth-shaped transitions. A criterion for best waveform selection and synchronization is presented and attainable enhancements are evaluated. In order to fully exploit this driving technique, a compact microprocessor-based architecture is proposed and a suitable data acquisition system implementation is presented. System linearity and efficiency characterization are also shown.

  18. Modeling piezoelectric ultrasonic transducers for physiotherapy

    International Nuclear Information System (INIS)

    Iglesias, E.; Frutos, J. de; Montero de Espinosa, F.

    2015-01-01

    Applications of ultrasound are well known in medical and aesthetic skin and subcutaneous fatty tissue mobilization treatments. The basic transducer used consists of a piezoelectric disk adhered to a metal delay line in capsule shape. The capsule design is critical since the two bonded elements have vibration modes which can cause very inefficient designs and vibration distributions very irregular if they are not properly studied and utilized. This must be known to avoid distributions of heat and sound pressure that could be ineffective or harmful. In this paper, using Finite Element Method and laser interferometric vibrational analysis, it has reached a piston-type solution that allows properly implement sound pressure vibration dose. (Author)

  19. Development of piezoelectric composites for transducers

    Science.gov (United States)

    Safari, A.

    1994-07-01

    For the past decade and a half, many different types of piezoelectric ceramic-polymer composites have been developed intended for transducer applications. These diphasic composites are prepared from non-active polymer, such as epoxy, and piezoelectric ceramic, such as PZT, in the form of filler powders, elongated fibers, multilayer and more complex three-dimensional structures. For the last four years, most of the efforts have been given to producing large area and fine scale PZT fiber composites. In this paper, processing of piezoelectric ceramic-polymer composites with various connectivity patterns are reviewed. Development of fine scale piezoelectric composites by lost mold, injection molding and the relic method are described. Research activities of different groups for preparing large area piezocomposites for hydrophone and actuator applications are briefly reviewed. Initial development of electrostrictive ceramics and composites are also

  20. Radical irradiation for carcinoma of the prostate

    African Journals Online (AJOL)

    1990-09-15

    Sep 15, 1990 ... Most patients (71%) were treated with 5 fractions per week. The remainder were treated with either 3 or 4 fractions per week because of limited machine availability (Table Ill). Megavoltage radiation was used in all patients with either cobalt 60 or a 20 MV linear accelerator. Race. Whites. Blacks. Mixed.

  1. Study of radionuclide 90Sr-90Y on cell proliferation and apoptosis in benign prostatic hyperplasia

    International Nuclear Information System (INIS)

    Zhang Tong; Wei Wei; Zou Benjie; Liu Fang; Xu Zhishun

    2003-01-01

    Objective: To investigate the effect of 90 Sr- 90 Yon cell proliferation and apoptosis in benign prostatic hyperplasia. Methods: The apoptosis and expression of Ki-67 in benign prostatic hyperplasia (BPH) before and after irradiation 90 Sr- 90 Y were detected by transferase-mediated dUTP-biotin nick end labeling (TUNEL) method and immunohistochemical technique, respectively. Results: The proliferation index (PI) of BPH after 90 Sr- 90 Y irradiation was much lower than that before irradiation, but there was no significant change in apoptosis index (AI). Conclusion: Irradiation with 90 Sr- 90 Y could restrain cell proliferation of BPH, but could not induce apoptosis

  2. Design optimization of embedded ultrasonic transducers for concrete structures assessment.

    Science.gov (United States)

    Dumoulin, Cédric; Deraemaeker, Arnaud

    2017-08-01

    In the last decades, the field of structural health monitoring and damage detection has been intensively explored. Active vibration techniques allow to excite structures at high frequency vibrations which are sensitive to small damage. Piezoelectric PZT transducers are perfect candidates for such testing due to their small size, low cost and large bandwidth. Current ultrasonic systems are based on external piezoelectric transducers which need to be placed on two faces of the concrete specimen. The limited accessibility of in-service structures makes such an arrangement often impractical. An alternative is to embed permanently low-cost transducers inside the structure. Such types of transducers have been applied successfully for the in-situ estimation of the P-wave velocity in fresh concrete, and for crack monitoring. Up to now, the design of such transducers was essentially based on trial and error, or in a few cases, on the limitation of the acoustic impedance mismatch between the PZT and concrete. In the present study, we explore the working principles of embedded piezoelectric transducers which are found to be significantly different from external transducers. One of the major challenges concerning embedded transducers is to produce very low cost transducers. We show that a practical way to achieve this imperative is to consider the radial mode of actuation of bulk PZT elements. This is done by developing a simple finite element model of a piezoelectric transducer embedded in an infinite medium. The model is coupled with a multi-objective genetic algorithm which is used to design specific ultrasonic embedded transducers both for hard and fresh concrete monitoring. The results show the efficiency of the approach and a few designs are proposed which are optimal for hard concrete, fresh concrete, or both, in a given frequency band of interest. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Prostate Cancer Biorepository Network

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-14-2-0185 TITLE: Prostate Cancer Biorepository Network PRINCIPAL INVESTIGATOR: Jonathan Melamed, MD CONTRACTING ORGANIZATION...AND SUBTITLE 5a. CONTRACT NUMBER Prostate Cancer Biorepository Network 5b. GRANT NUMBER W81XWH-14-2-0185 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...infrastructure and operations of the Prostate Cancer Biorepository Network (PCBN). The aim of the PCBN is to provide prostate researchers with high-quality

  4. Comprehensive overview of prostatitis.

    Science.gov (United States)

    Khan, Farhan Ullah; Ihsan, Awais Ullah; Khan, Hidayat Ullah; Jana, Ruby; Wazir, Junaid; Khongorzul, Puregmaa; Waqar, Muhammad; Zhou, Xiaohui

    2017-10-01

    Prostatitis is a common urinary tract syndrome that many doctors find problematic to treat effectively. It is the third most commonly found urinary tract disease in men after prostate cancer and Benign Prostate Hyperplasia (BPH). Prostatitis may account for 25% of all office visits made to the urological clinics complaining about the genital and urinary systems all over the world. In the present study, we classified prostatitis and comprehensively elaborated the etiology, pathogenesis, diagnosis, and treatment of acute bacterial prostatitis (category I), chronic bacterial prostatitis (category II), chronic pelvic pain syndrome (CPPS) (category III), and asymptomatic prostatitis (category IV). In addition, we also tried to get some insights about other types of prostatitis-like fungal, viral and gonococcal prostatitis. The aim of this review is to present the detail current perspective of prostatitis in a single review. To the best of our knowledge currently, there is not a single comprehensive review, which can completely elaborate this important topic in an effective way. Furthermore, this review will provide a solid platform to conduct future studies on different aspects such as risk factors, mechanism of pathogenesis, proper diagnosis, and rational treatment plans for fungal, viral, and gonococcal prostatitis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Enlarged Prostate (BPH)

    Science.gov (United States)

    The prostate is a gland in men. It helps make semen, the fluid that contains sperm. The prostate surrounds the tube that carries urine out of the body. As men age, their prostate grows bigger. If it gets too large, it ...

  6. A method for determining losses in magnetostrictive transducers

    Science.gov (United States)

    Krysin, V. N.; Ketlerov, A. S.

    A method for estimating energy losses in magnetostrictive transducers is described. It is shown that domain remagnetization is responsible for the greatest energy loss in magnetostrictive transducers. Energy losses associated with Foucault currents and Joule heat are an order of magnitude less.

  7. Resonant acoustic transducer system for a well drilling string

    Science.gov (United States)

    Nardi, Anthony P.

    1981-01-01

    For use in transmitting acoustic waves propated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting a resonant operation in the desired low frequency range.

  8. Resonant transducers for solid-state plasma density modulation

    Energy Technology Data Exchange (ETDEWEB)

    Hallock, Gary A., E-mail: hallock@ece.utexas.edu [The University of Texas at Austin, Austin, Texas 78701 (United States); Meier, Mark A., E-mail: mark.a.meier@exxonmobil.com [ExxonMobil Upstream Research Company, Houston, Texas 77389 (United States)

    2016-04-15

    We have developed transducers capable of modulating the plasma density and plasma density gradients in indium antimonide. These transducers make use of piezoelectric drivers to excite acoustic pressure resonance at 3λ/2, generating large amplitude standing waves and plasma density modulations. The plasma density has been directly measured using a laser diagnostic. A layered media model shows good agreement with the experimental measurements.

  9. Optimization of ultrasonic tube testing with concentric transducers

    International Nuclear Information System (INIS)

    Dufayet, J.-P.; Gambin, Raymond.

    1978-01-01

    In order to test tubes by ultrasonics without rotation, concentric transducers can be used with conical mirrors to detect transverse defects and with helical shaped mirrors to detect longitudinal defects. Further optimization studies have been carried out in order to bring the system highly operational. The respective advantages brought by the rotating screen or by our especially designed sectorial transducers are discussed [fr

  10. Respiratory Belt Transducer Constructed Using a Singing Greeting Card Beeper

    Science.gov (United States)

    Bhaskar, Anand; Subramani, Selvam; Ojha, Rajdeep

    2013-01-01

    An article by Belusic and Zupancic described the construction of a finger pulse sensor using a singing greeting card beeper. These authors felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers,…

  11. Design and performance of the drag-disc turbine transducer

    International Nuclear Information System (INIS)

    Averill, R.H.; Goodrich, L.D.; Ford, R.E.

    1979-01-01

    Mass flow rates at the Loss-of-Fluid Test (LOFT) facility, EG and G Idaho, Inc., at the Idaho National Engineering Laboratory, are measured with the drag-disc turbine transducer (DTT). Operational description of the DTT and the developmental effort are discussed. Performance data and experiences with this transducer have been evaluated and are presented in this paper

  12. A mathematical model for transducer working at high temperature

    International Nuclear Information System (INIS)

    Fabre, J.P.

    1974-01-01

    A mathematical model is proposed for a lithium niobate piezoelectric transducer working at high temperature in liquid sodium. The model proposed suitably described the operation of the high temperature transducer presented; it allows the optimization of the efficiency and band-pass [fr

  13. A Force Transducer from a Junk Electronic Balance

    Science.gov (United States)

    Aguilar, Horacio Munguia; Aguilar, Francisco Armenta

    2009-01-01

    It is shown how the load cell from a junk electronic balance can be used as a force transducer for physics experiments. Recovering this device is not only an inexpensive way of getting a valuable laboratory tool but also very useful didactic work on electronic instrumentation. Some experiments on mechanics with this transducer are possible after a…

  14. Transducer hygiene: comparison of procedures for decontamination of ultrasound transducers and their use in clinical practice.

    Science.gov (United States)

    Häggström, Mikael; Spira, Jack; Edelstam, Greta

    2015-02-01

    To determine whether current hygiene practices are appropriate during sonographic examinations. Five major hospitals in Sweden were investigated with a survey. At each hospital, the departments corresponding to the main types of sonographic examination were chosen. Personnel who were responsible for or acquainted with the local hygiene procedures completed a standardardized questionnaire. The surveys were completed by 25 departments, where the total number of sonographic examinations was approximately 20,000 per month. For transvaginal and transrectal sonographic examinations, the most common method for decontamination of the transducer was barrier protection during the procedure followed by cleansing with alcohol. Latex was the predominant cover material, but one department used polyethylene gloves, and another department used nitrile gloves. Both of these involved transvaginal ultrasonography. In transcutaneous examinations, all hospitals were using alcohol and paper or cloth for decontamination at a minimum. Transesophageal examinations were carried out without barrier protection, and decontamination was performed with an alkylating substance. The hygiene practices appear to be appropriate at most hospitals, but there is a prevalence of transducer cover materials of unacceptable permeability, as well as use of gloves on transducers despite insufficient evidence of safety. © 2015 Wiley Periodicals, Inc.

  15. Transducers for Sound and Vibration - FEM Based Design

    DEFF Research Database (Denmark)

    Liu, Bin

    2001-01-01

    Design of transducers for measurement of vibration (piezoelectric accelerometers) and sound (condenser microphones) is a very labour intensive work. The design work is mostly based on experience and on simple analogies to electrical circuit design. Often a time consuming itterative loop is used......: Specification of the transducer, production of a physical prototype, measurements on the prototype, changed specification of the transducer etc. Furthermore are many transducers made based on customer requirements which also increases the amount of required design work. For these reasons there is a need...... for methods that can reduce the design time consumption and the number of itterations. The present work proposes to use finite element based programs for simulating the behaviour of a transducer with a given set of specifications. A simulation program for accelerometers was developed and has been tested...

  16. Study on electrical impedance matching for broadband ultrasonic transducer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon Woo [University of Science and Technology, Daejeon (Korea, Republic of); Kim, Ki Bok [Korea Research Institute of Standards and Science, Center for Safety Measurement, Daejeon (Korea, Republic of); Baek, Kwang Sae [Elache Co., Busan (Korea, Republic of)

    2017-02-15

    Ultrasonic transducers with high resolution and resonant frequency are required to detect small defects (less than hundreds of μm) by ultrasonic testing. The resonance frequency and resolution of an ultrasonic transducer are closely related to the thickness of piezo-electric materials, backing materials, and the electric impedance matching technique. Among these factors, electrical impedance matching plays an important role because it can reduce the loss and reflection of ultrasonic energy differences in electrical impedance between an ultrasonic transducer and an ultrasonic defects detecting system. An LC matching circuit is the most frequently used electric matching method. It is necessary for the electrical impedance of an ultrasonic transducer to correspond to approximately 50 Ω to compensate the difference in electrical impedance between both connections. In this study, a 15 MHz immersion ultrasonic transducer was fabricated and an LC electrical impedance circuit was applied to that for having broad-band frequency characteristic.

  17. Targeting Stromal Androgen Receptor Suppresses Prolactin-Driven Benign Prostatic Hyperplasia (BPH)

    Science.gov (United States)

    Lai, Kuo-Pao; Huang, Chiung-Kuei; Fang, Lei-Ya; Izumi, Kouji; Lo, Chi-Wen; Wood, Ronald; Kindblom, Jon; Yeh, Shuyuan

    2013-01-01

    Stromal-epithelial interaction plays a pivotal role to mediate the normal prostate growth, the pathogenesis of benign prostatic hyperplasia (BPH), and prostate cancer development. Until now, the stromal androgen receptor (AR) functions in the BPH development, and the underlying mechanisms remain largely unknown. Here we used a genetic knockout approach to ablate stromal fibromuscular (fibroblasts and smooth muscle cells) AR in a probasin promoter-driven prolactin transgenic mouse model (Pb-PRL tg mice) that could spontaneously develop prostate hyperplasia to partially mimic human BPH development. We found Pb-PRL tg mice lacking stromal fibromuscular AR developed smaller prostates, with more marked changes in the dorsolateral prostate lobes with less proliferation index. Mechanistically, prolactin mediated hyperplastic prostate growth involved epithelial-stromal interaction through epithelial prolactin/prolactin receptor signals to regulate granulocyte macrophage-colony stimulating factor expression to facilitate stromal cell growth via sustaining signal transducer and activator of transcription-3 activity. Importantly, the stromal fibromuscular AR could modulate such epithelial-stromal interacting signals. Targeting stromal fibromuscular AR with the AR degradation enhancer, ASC-J9®, led to the reduction of prostate size, which could be used in future therapy. PMID:23893956

  18. A Critical Role of the PTEN/PDGF Signaling Network for the Regulation of Radiosensitivity in Adenocarcinoma of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Michael, E-mail: mechristense@uwalumni.com [Department of Radiation Oncology, Wayne State University School of Medicine, Barbara Ann Karmanos Cancer Center, Detroit, Michigan (United States); Najy, Abdo J. [Department of Pathology, Wayne State University School of Medicine, Barbara Ann Karmanos Cancer Center, Detroit, Michigan (United States); Snyder, Michael; Movilla, Lisa S. [Department of Radiation Oncology, Wayne State University School of Medicine, Barbara Ann Karmanos Cancer Center, Detroit, Michigan (United States); Kim, Hyeong-Reh Choi [Department of Pathology, Wayne State University School of Medicine, Barbara Ann Karmanos Cancer Center, Detroit, Michigan (United States)

    2014-01-01

    Purpose: Loss or mutation of the phosphate and tensin homologue (PTEN) is a common genetic abnormality in prostate cancer (PCa) and induces platelet-derived growth factor D (PDGF D) signaling. We examined the role of the PTEN/PDGF axis on radioresponse using a murine PTEN null prostate epithelial cell model. Methods and Materials: PTEN wild-type (PTEN{sup +/+}) and PTEN knockout (PTEN{sup −/−}) murine prostate epithelial cell lines were used to examine the relationship between the PTEN status and radiosensitivity and also to modulate the PDGF D expression levels. PTEN{sup −/−} cells were transduced with a small hairpin RNA (shRNA) lentiviral vector containing either scrambled nucleotides (SCRM) or sequences targeted to PDGF D (shPDGF D). Tumorigenesis and morphogenesis of these cell lines were evaluated in vivo via subcutaneous injection of male nude mice and in vitro using Matrigel 3-dimensional (3D) culture. Effects of irradiation on clonogenic survival, cell migration, and invasion were measured with respect to the PTEN status and the PDGF D expression level. In addition, apoptosis and cell cycle redistribution were examined as potential mechanisms for differences seen. Results: PTEN{sup −/−} cells were highly tumorigenic in animals and effectively formed foci in 3D culture. Importantly, loss of PDGF D in these cell lines drastically diminished these phenotypes. Furthermore, PTEN{sup −/−} cells demonstrated increased clonogenic survival in vitro compared to PTEN{sup +/+}, and attenuation of PDGF D significantly reversed this radioresistant phenotype. PTEN{sup −/−} cells displayed greater migratory and invasive potential at baseline as well as after irradiation. Both the basal and radiation-induced migratory and invasive phenotypes in PTEN{sup −/−} cells required PDGF D expression. Interestingly, these differences were independent of apoptosis and cell cycle redistribution, as they showed no significant difference. Conclusions: We propose

  19. Nonbacterial prostatitis: a comprehensive review

    NARCIS (Netherlands)

    de la Rosette, J. J.; Debruyne, F. M.

    1991-01-01

    The term 'prostatitis' denotes a condition of inflammation of the prostate. Prostatitis is usually employed to describe any unexplained symptom or condition that might possibly emanate from a disorder of the prostate gland. The diagnosis of nonbacterial prostatitis is reserved for those patients

  20. Prostate-specific antigen density: correlation with histological diagnosis of prostate cancer, benign prostatic hyperplasia and prostatitis

    NARCIS (Netherlands)

    van Iersel, M. P.; Witjes, W. P.; de la Rosette, J. J.; Oosterhof, G. O.

    1995-01-01

    To assess the additional value of prostate-specific antigen density in the diagnosis of prostate cancer in patients who undergo prostate biopsies. The study comprised 376 patients with symptoms of prostatism who were undergoing prostate biopsy. Digital rectal examination (DRE) and transrectal

  1. urethral plasmakinetic resection of prostate on prostate- specific ...

    African Journals Online (AJOL)

    reduce blood flow in BPH, thereby preventing bleeding [6,7]. Thus ... urethra, prostate and surrounding tissue ... The peripheral blood and prostatic fluid of the patients ... Coronary heart ..... Length Density of Prostate Vessels, Intraoperative,.

  2. The management of localized and locally advanced prostate cancer - 1995

    International Nuclear Information System (INIS)

    Forman, Jeffrey D.

    1995-01-01

    Purpose/Objectives: The intent of this course is to review the issues involved in the management of non-metastatic adenocarcinoma of the prostate. - The value of pre-treatment prognostic factors including stage, grade and PSA value will be presented, and their value in determining therapeutic strategies will be discussed. - Controversies involving the simulation process and treatment design will be presented. The value of CT scanning, Beams-Eye View, 3-D planning, intravesicle, intraurethral and rectal contrast will be presented. The significance of prostate and patient movement and strategies for dealing with them will be presented. - The management of low stage, low to intermediate grade prostate cancer will be discussed. The dose, volume and timing of irradiation will be discussed as will the role of neo-adjuvant hormonal therapy, neutron irradiation and brachy therapy. The current status of radical prostatectomy and cryotherapy will be summarized. - Treatment of locally advanced, poorly differentiated prostate cancer will be presented including a discussion of neo-adjuvant and adjuvant hormones, dose-escalation and neutron irradiation. - Strategies for post-radiation failures will be presented including data on cryotherapy, salvage prostatectomy and hormonal therapy (immediate, delayed and/or intermittent). New areas for investigation will be reviewed. - The management of patients post prostatectomy will be reviewed. Data on adjuvant radiation and therapeutic radiation for biochemical or clinically relapsed patients will be presented. This course hopes to present a realistic and pragmatic overview for treating patients with non-metastatic prostatic cancer

  3. Numerical comparison of patch and sandwich piezoelectric transducers for transmitting ultrasonic waves

    CSIR Research Space (South Africa)

    Loveday, PW

    2006-03-01

    Full Text Available in the waveguide. Piezoelectric patch transducers are frequently employed, by researchers, for exciting waves in beam like structures. Sonar systems frequently make use of resonant transducers, such as sandwich transducers, for acoustic wave generation...

  4. WE-EF-210-07: Development of a Minimally Invasive Photo Acoustic Imaging System for Early Prostate Cancer Detection

    Energy Technology Data Exchange (ETDEWEB)

    Sano, M; Yousefi, S; Xing, L [Stanford University School of Medicine, Stanford, CA (United States)

    2015-06-15

    Purpose: The objective of this work is to design, implement and characterize a catheter-based ultrasound/photoacoustic imaging probe for early-diagnosis of prostate cancer and to aid in image-guided radiation therapy. Methods: The need to image across 6–10cm of tissue to image the whole prostate gland limits the resolution achievable with a transrectal ultrasound approach. In contrast, the urethra bisects the prostate gland, providing a minimally invasive pathway for deploying a high resolution ultrasound transducer. Utilizing a high-frequency (20MHz) ultrasound/photoacoustic probe, high-resolution structural and molecular imaging of the prostate tissue is possible. A custom 3D printed probe containing a high-frequency single-element ultrasound transducer is utilized. The diameter of the probe is designed to fit inside a Foley catheter and the probe is rotated around the central axis to achieve a circular B-scan. A custom ultrasound amplifier and receiver was set up to trigger the ultrasound pulse transmission and record the reflected signal. The reconstructed images were compared to images generated by traditional 5 MHz ultrasound transducers. Results: The preliminary results using the high-frequency ultrasound probe show that it is possible to resolve finely detailed information in a prostate tissue phantom that was not achievable with previous low-frequency ultrasound systems. Preliminary ultrasound imaging was performed on tissue mimicking phantom and sensitivity and signal-to-noise ratio of the catheter was measured. Conclusion: In order to achieve non-invasive, high-resolution, structural and molecular imaging for early-diagnosis and image-guided radiation therapy of the prostate tissue, a transurethral catheter was designed. Structural/molecular imaging using ultrasound/photoacoustic of the prostate tissue will allow for localization of hyper vascularized areas for early-stage prostate cancer diagnosis.

  5. Prostate cancer

    DEFF Research Database (Denmark)

    Elkjær, Maria Carlsen; Andersen, Morten Heebøll; Høyer, Søren

    2017-01-01

    Background Active surveillance (AS) of low-risk prostate cancer (PCa) is an accepted alternative to active treatment. However, the conventional diagnostic trans-rectal ultrasound guided biopsies (TRUS-bx) underestimate PCa aggressiveness in almost half of the cases, when compared with the surgical...... lesions. Significant cancer was defined as GS > 6 or GS 6 (3 + 3) lesions with ≥ 6 mm maximal cancer core length (MCCL). Results A total of 78 patients were included and in 21 patients a total of 22 PIRADS-score 4 or 5 lesions were detected. MRGB pathology revealed that 17 (81%) of these and 22......% of the entire AS population harbored significant cancers at AS inclusion. In eight (38%) cases, the GS was upgraded. Also, nine patients (43%) had GS 6 (3 + 3) foci with MCCL ≥ 6 mm. Conclusion In an AS cohort based on TRUS and TRUS-bx diagnostic strategies, supplemental mpMRI and in-bore MRGB were able...

  6. A comparison of ventilatory prostate movement in four treatment positions

    International Nuclear Information System (INIS)

    Dawson, Laura A.; Litzenberg, Dale W.; Brock, Kristy K.; Sanda, Martin; Sullivan, Molly; Sandler, Howard M.; Balter, James M.

    2000-01-01

    Purpose: To ensure target coverage during radiotherapy, all sources of geometric uncertainty in target position must be considered. Movement of the prostate due to breathing has not traditionally been considered in prostate radiotherapy. The purpose of this study is to report the influence of patient orientation and immobilization on prostate movement due to breathing. Methods and Materials: Four patients had radiopaque markers implanted in the prostate. Fluoroscopy was performed in four different positions: prone in alpha cradle, prone with an aquaplast mold, supine on a flat table, and supine with a false table under the buttocks. Fluoroscopic movies were videotaped and digitized. Frames were analyzed using 2D-alignment software to determine the extent of movement of the prostate markers and the skeleton for each position during normal and deep breathing. Results: During normal breathing, maximal movement of the prostate markers was seen in the prone position (cranial-caudal [CC] range: 0.9-5.1 mm; anterior-posterior [AP] range: up to 3.5 mm). In the supine position, prostate movement during normal breathing was less than 1 mm in all directions. Deep breathing resulted in CC movements of 3.8-10.5 mm in the prone position (with and without an aquaplast mold). This range was reduced to 2.0-7.3 mm in the supine position and 0.5-2.1 mm with the use of the false table top. Deep breathing resulted in AP skeletal movements of 2.7-13.1 mm in the prone position, whereas AP skeletal movements in the supine position were negligible. Conclusion: Ventilatory movement of the prostate is substantial in the prone position and is reduced in the supine position. The potential for breathing to influence prostate movement, and thus the dose delivered to the prostate and normal tissues, should be considered when positioning and planning patients for conformal irradiation

  7. Mechanical Amplifier for a Piezoelectric Transducer

    Science.gov (United States)

    Moore, James; Swain, Mark; Lawson, Peter; Calvet, Robert

    2003-01-01

    A mechanical amplifier has been devised to multiply the stroke of a piezoelectric transducer (PZT) intended for use at liquid helium temperatures. Interferometry holds the key to high angular resolution imaging and astrometry in space. Future space missions that will detect planets around other solar systems and perform detailed studies of the evolution of stars and galaxies will use new interferometers that observe at mid- and far-infrared wavelengths. Phase-measurement interferometry is key to many aspects of astronomical interferometry, and PZTs are ideal modulators for most methods of phase measurement, but primarily at visible wavelengths. At far infrared wavelengths of 150 to 300 m, background noise is a severe problem and all optics must be cooled to about 4 K. Under these conditions, piezos are ill-suited as modulators, because their throw is reduced by as much as a factor of 2, and even a wavelength or two of modulation is beyond their capability. The largest commercially available piezo stacks are about 5 in. (12.7 cm) long and have a throw of about 180 m at room temperature and only 90 m at 4 K. It would seem difficult or impossible to use PZTs for phase measurements in the far infrared were it not for the new mechanical amplifier that was designed and built.

  8. Piezoelectric Nanotube Array for Broadband High-Frequency Ultrasonic Transducer.

    Science.gov (United States)

    Liew, Weng Heng; Yao, Kui; Chen, Shuting; Tay, Francis Eng Hock

    2018-03-01

    Piezoelectric materials are vital in determining ultrasonic transducer and imaging performance as they offer the function for conversion between mechanical and electrical energy. Ultrasonic transducers with high-frequency operation suffer from performance degradation and fabrication difficulty of the demanded piezoelectric materials. Hence, we propose 1-D polymeric piezoelectric nanostructure with controlled nanoscale features to overcome the technical limitations of high-frequency ultrasonic transducers. For the first time, we demonstrate the integration of a well-aligned piezoelectric nanotube array to produce a high-frequency ultrasonic transducer with outstanding performance. We find that nanoconfinement-induced polarization orientation and unique nanotube structure lead to significantly improved piezoelectric and ultrasonic transducing performance over the conventional piezoelectric thin film. A large bandwidth, 126% (-6 dB), is achieved at high center frequency, 108 MHz. Transmission sensitivity of nanotube array is found to be 46% higher than that of the monolithic thin film transducer attributed to the improved electromechanical coupling effectiveness and impedance match. We further demonstrate high-resolution scanning, ultrasonic imaging, and photoacoustic imaging using the obtained nanotube array transducers, which is valuable for biomedical imaging applications in the future.

  9. Bonding and impedance matching of acoustic transducers using silver epoxy.

    Science.gov (United States)

    Son, Kyu Tak; Lee, Chin C

    2012-04-01

    Silver epoxy was selected to bond transducer plates on glass substrates. The properties and thickness of the bonding medium affect the electrical input impedance of the transducer. Thus, the thickness of the silver epoxy bonding layer was used as a design parameter to optimize the structure for the transducer input impedance to match the 50 Ω output impedance of most radio frequency (RF) generators. Simulation and experimental results show that nearly perfect matching is achieved without using any matching circuit. At the matching condition, the transducer operates at a frequency band a little bit below the half-wavelength resonant frequency of the piezoelectric plate. In experiments, lead titanate (PT) piezoelectric plates were employed. Both full-size, 11.5 mm × 2 mm × 0.4 mm, and half-size, 5.75 mm × 2 mm × 0.4 mm, can be well matched using optimal silver epoxy thickness. The transducer assemblies demonstrate high efficiency. The conversion loss from electrical power to acoustic power in soda-lime glass is 4.3 dB. This loss is low considering the fact that the transducers operate at off-resonance by 12%. With proper choice of silver epoxy thickness, the transducer can be matched at the fundamental, the 3rd and 5th harmonic frequencies. This leads to the possible realization of triple-band transducers. Reliability was assessed with thermal cycling test according to Telcordia GR-468-Core recommendation. Of the 30 transducer assemblies tested, none broke until 2900 cycles and 27 have sustained beyond 4050 cycles. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. DIFFERENTIAL DIAGNOSTICS OF PROSTATE TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    E. V. Brizhatyuk

    2017-01-01

    Full Text Available Prostate tuberculosis is difficult to be diagnosed, especially if lesions are limited only by this organ. The article analyses the experience of differential diagnostics of prostate tuberculosis based on the data of examination of 84 patients. 45 of them were diagnosed with prostate tuberculosis, and 39 patients were diagnosed with chronic bacterial prostatitis. Pathognomonic diagnostics criteria of prostate tuberculosis were the following: detection of tuberculous mycobacteria in the prostatic fluid or ejaculate, signs of granulomatous prostatitis with areas of cavernous necrosis in prostate biopsy samples, and prostate cavities visualized by X-ray or ultrasound examinations. Should the above criteria be absent, the disease can be diagnosed based on the combination of indirect signs: symptoms of prostate inflammation with active tuberculosis of the other localization; large prostate calcification, extensive hyperechoic area of the prostate, spermatocystic lesions, leucospermia and hemospermia, failure of the adequate non-specific anti-bacterial therapy.

  11. Estrogen receptors in the human male prostatic urethra and prostate in prostatic cancer and benign prostatic hyperplasia

    DEFF Research Database (Denmark)

    Bødker, A; Bruun, J; Balslev, E

    1999-01-01

    Estrogen receptors (ERs) in the prostate and prostatic urethra were examined in 33 men with benign prostatic hyperplasia (BPH) and in 11 with prostate cancer (PC). The Abbot monoclonal ER-ICA assay was used for immunohistochemical investigation. In the BPH group, ERs were revealed in the prostatic...... demonstrated in the prostatic stroma and/or prostatic urethra in 6 out of 11 cases. In both BPH and PC patients, immunoreactivity was weak and confined to few cells, indicating low ER content in the prostate as well as in the prostatic urethra. Dextran-coated charcoal (DCC) analysis was used for detection...... and quanticization of cytosolic and nuclear ERs. In the BPH group, ERs were detected once in the prostate and prostatic urethra in the nuclear and cytosol, and additionally in the prostatic urethra in the cytosol fraction in three cases. In all cases, ER content was low, ranging from 10-15 fmol/mg protein. In the PC...

  12. Risks of Prostate Cancer Screening

    Science.gov (United States)

    ... prostate. The prostate is a gland in the male reproductive system located just below the bladder (the organ that ... up part of semen . Enlarge Anatomy of the male reproductive and urinary systems, showing the prostate, testicles, bladder, and other organs. ...

  13. Prostatic specific antigen for prostate cancer detection

    Directory of Open Access Journals (Sweden)

    Lucas Nogueira

    2009-10-01

    Full Text Available Prostate-specific antigen (PSA has been used for prostate cancer detection since 1994. PSA testing has revolutionized our ability to diagnose, treat, and follow-up patients. In the last two decades, PSA screening has led to a substantial increase in the incidence of prostate cancer (PC. This increased detection caused the incidence of advanced-stage disease to decrease at a dramatic rate, and most newly diagnosed PC today are localized tumors with a high probability of cure. PSA screening is associated with a 75% reduction in the proportion of men who now present with metastatic disease and a 32.5% reduction in the age-adjusted prostate cancer mortality rate through 2003. Although PSA is not a perfect marker, PSA testing has limited specificity for prostate cancer detection, and its appropriate clinical application remains a topic of debate. Due to its widespread use and increased over-detection, the result has been the occurrence of over-treatment of indolent cancers. Accordingly, several variations as regards PSA measurement have emerged as useful adjuncts for prostate cancer screening. These procedures take into consideration additional factors, such as the proportion of different PSA isoforms (free PSA, complexed PSA, pro-PSA and B PSA, the prostate volume (PSA density, and the rate of change in PSA levels over time (PSA velocity or PSA doubling time. The history and evidence underlying each of these parameters are reviewed in the following article.

  14. Prostatic specific antigen for prostate cancer detection.

    Science.gov (United States)

    Nogueira, Lucas; Corradi, Renato; Eastham, James A

    2009-01-01

    Prostate-specific antigen (PSA) has been used for prostate cancer detection since 1994. PSA testing has revolutionized our ability to diagnose, treat, and follow-up patients. In the last two decades, PSA screening has led to a substantial increase in the incidence of prostate cancer (PC). This increased detection caused the incidence of advanced-stage disease to decrease at a dramatic rate, and most newly diagnosed PC today are localized tumors with a high probability of cure. PSA screening is associated with a 75% reduction in the proportion of men who now present with metastatic disease and a 32.5% reduction in the age-adjusted prostate cancer mortality rate through 2003. Although PSA is not a perfect marker, PSA testing has limited specificity for prostate cancer detection, and its appropriate clinical application remains a topic of debate. Due to its widespread use and increased over-detection, the result has been the occurrence of over-treatment of indolent cancers. Accordingly, several variations as regards PSA measurement have emerged as useful adjuncts for prostate cancer screening. These procedures take into consideration additional factors, such as the proportion of different PSA isoforms (free PSA, complexed PSA, pro-PSA and B PSA), the prostate volume (PSA density), and the rate of change in PSA levels over time (PSA velocity or PSA doubling time). The history and evidence underlying each of these parameters are reviewed in the following article.

  15. Broadband electrical impedance matching for piezoelectric ultrasound transducers.

    Science.gov (United States)

    Huang, Haiying; Paramo, Daniel

    2011-12-01

    This paper presents a systematic method for designing broadband electrical impedance matching networks for piezoelectric ultrasound transducers. The design process involves three steps: 1) determine the equivalent circuit of the unmatched piezoelectric transducer based on its measured admittance; 2) design a set of impedance matching networks using a computerized Smith chart; and 3) establish the simulation model of the matched transducer to evaluate the gain and bandwidth of the impedance matching networks. The effectiveness of the presented approach is demonstrated through the design, implementation, and characterization of impedance matching networks for a broadband acoustic emission sensor. The impedance matching network improved the power of the acquired signal by 9 times.

  16. USE OF PELTIER COOLERS AS SOIL HEAT FLUX TRANSDUCERS.

    Science.gov (United States)

    Weaver, H.L.; Campbell, G.S.

    1985-01-01

    Peltier coolers were modified and calibrated to serve as soil heat flux transducers. The modification was to fill their interiors with epoxy. The average calibration constant on 21 units was 13. 6 plus or minus 0. 8 kW m** minus **2 V** minus **1 at 20 degree C. This sensitivity is about eight times that of the two thermopile transducers with which comparisons were made. The thermal conductivity of the Peltier cooler transducers was 0. 4 W m** minus **1 degree C** minus **1, which is comparable to that of dry soil.

  17. Reflective array modeling for reflective and directional SAW transducers.

    Science.gov (United States)

    Morgan, D P

    1998-01-01

    This paper presents a new approximate method for analyzing reflective SAW transducers, with much of the convenience of the coupled-mode (COM) method but with better accuracy. Transduction accuracy is obtained by incorporating the accurate electrostatic solution, giving for example correct harmonics, and allowance for electrode width variation, in a simple manner. Results are shown for a single-electrode transducer, Natural SPUDT and DART SPUDT, each using theoretically derived parameters. In contrast to the COM, the RAM can give accurate results for short or withdrawal-weighted transducers and for wide analysis bandwidth.

  18. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  19. TRP Channels in Human Prostate

    Directory of Open Access Journals (Sweden)

    Carl Van Haute

    2010-01-01

    Full Text Available This review gives an overview of morphological and functional characteristics in the human prostate. It will focus on the current knowledge about transient receptor potential (TRP channels expressed in the human prostate, and their putative role in normal physiology and prostate carcinogenesis. Controversial data regarding the expression pattern and the potential impact of TRP channels in prostate function, and their involvement in prostate cancer and other prostate diseases, will be discussed.

  20. Food irradiation

    International Nuclear Information System (INIS)

    Soothill, R.

    1987-01-01

    The issue of food irradiation has become important in Australia and overseas. This article discusses the results of the Australian Consumers' Association's (ACA) Inquiry into food irradiation, commissioned by the Federal Government. Issues discussed include: what is food irradiation; why irradiate food; how much food is consumer rights; and national regulations

  1. Quantification of prostate movements during radiotherapy

    International Nuclear Information System (INIS)

    Artignana, X.; Rastkhah, M.; Balosso, J.; Bolla, M.; Fourneret, P.; Gilliot, O.

    2006-01-01

    Decrease treatment uncertainties is one of the most important challenge in radiation oncology. Numerous techniques are available to quantify prostate motion and visualize prostate location day after day before each irradiation: CT-scan, cone-beam-CT-Scan, ultrasound, prostatic markers... The knowledge of prostate motion is necessary to define the minimal margin around the target volume needed to avoid mis-positioning during treatment session. Different kind of prostate movement have been studied and are reported in the present work: namely, those having a large amplitude extending through out the whole treatment period on one hand; and those with a shorter amplitude happening during treatment session one the other hand. The long lasting movement are mostly anterior posterior (3 mm standard deviation), secondary in cranial-caudal (1-2 mm standard deviation) and lateral directions (0.5-1 mm standard deviation). They are mostly due to the rectal state of filling and mildly due to bladder filling or inferior limbs position. On the other hand the shorter movement that occurs during the treatment session is mostly variation of position around a steady point represented by the apex. Ones again, the rectal filling state is the principle cause. This way, during the 20 minutes of a treatment session, including the positioning of the patient, a movement of less than 3 mm could be expected when the rectum is empty. Ideally, real time imaging tools should allow an accurate localisation of the prostate and the adaptation of the dosimetry before each treatment session in a time envelope not exceeding 20 minutes. (author)

  2. Combined radio- and hormone therapy of the prostate carcinoma

    International Nuclear Information System (INIS)

    Papic, R.

    1979-08-01

    Intention of this study is to detect in 49 patients suffering from prostate carcinomas, effects and side effects of radiotherapy. According to the present results, there is not any doubt that prostate carcinomas are radiosensitive. In all patients radiotherapy induced a prostate shrinkage and an increasing of consistency. It resulted that a prostate biopsy must be carried out in order to control the success of therapy. The success of the treatment depends upon tumour spreading and on its degree of differentiation. Within the observation period only in four cases metastasation of the prostate carcinoma occurred after radiotherapy. According to literature, the 5-year survival rate with an organ-defined prostate carcinoma ranges between 70 and 80% when radiotherapeutic methods are applied. The same authors indicate a 5-year survival rate between 42 and 48% for scattered carcinomas. Only minor side effects are provoked by radiotherapy. In 75% of the patients pollakisuria and dysuria resulted. After irradiation was finished, the symptoms disappeared and did not cause in any case any late complications. In 12% of the cases proctitic pain occurred during irradiation, which in 6% remained even after the treatment was terminated. We could prove unequivocally on our patients that passage impairments caused by a prostate carcinoma are improved by radiotherapy. Finally it can be said that this treatment is applicable for curing carcinoma which is localised on the prostate. In the case of an undefined, scattered carcinoma radiotherapy combined with hormone therapy is the treatment of choice. With regards to undesired side effects radiotherapy is superior to other therapeutic measures. (orig./MG) [de

  3. Electromechanically active polymer transducers: research in Europe

    Science.gov (United States)

    Carpi, Federico; Graz, Ingrid; Jager, Edwin; Ladegaard Skov, Anne; Vidal, Frédéric

    2013-10-01

    Smart materials and structures based on electromechanically active polymers (EAPs) represent a fast growing and stimulating field of research and development. EAPs are materials capable of changing dimensions and/or shape in response to suitable electrical stimuli. They are commonly classified in two major families: ionic EAPs (activated by an electrically induced transport of ions and/or solvent) and electronic EAPs (activated by electrostatic forces). These polymers show interesting properties, such as sizable active strains and/or stresses in response to electrical driving, high mechanical flexibility, low density, structural simplicity, ease of processing and scalability, no acoustic noise and, in most cases, low costs. Since many of these characteristics can also describe natural muscle tissues from an engineering standpoint, it is not surprising that EAP transducers are sometimes also referred to as 'muscle-like smart materials' or 'artificial muscles'. They are used not only to generate motion, but also to sense or harvest energy from it. In particular, EAP electromechanical transducers are studied for applications that can benefit from their 'biomimetic' characteristics, with possible usages from the micro- to the macro-scale, spanning several disciplines, such as mechatronics, robotics, automation, biotechnology and biomedical engineering, haptics, fluidics, optics and acoustics. Currently, the EAP field is just undergoing its initial transition from academic research into commercialization, with companies starting to invest in this technology and the first products appearing on the market. This focus issue is intentionally aimed at gathering contributions from the most influential European groups working in the EAP field. In fact, today Europe hosts the broadest EAP community worldwide. The rapid expansion of the EAP field in Europe, where it historically has strong roots, has stimulated the creation of the 'European Scientific Network for Artificial

  4. Active acoustical impedance using distributed electrodynamical transducers.

    Science.gov (United States)

    Collet, M; David, P; Berthillier, M

    2009-02-01

    New miniaturization and integration capabilities available from emerging microelectromechanical system (MEMS) technology will allow silicon-based artificial skins involving thousands of elementary actuators to be developed in the near future. SMART structures combining large arrays of elementary motion pixels coated with macroscopic components are thus being studied so that fundamental properties such as shape, stiffness, and even reflectivity of light and sound could be dynamically adjusted. This paper investigates the acoustic impedance capabilities of a set of distributed transducers connected with a suitable controlling strategy. Research in this domain aims at designing integrated active interfaces with a desired acoustical impedance for reaching an appropriate global acoustical behavior. This generic problem is intrinsically connected with the control of multiphysical systems based on partial differential equations (PDEs) and with the notion of multiscaled physics when a dense array of electromechanical systems (or MEMS) is considered. By using specific techniques based on PDE control theory, a simple boundary control equation capable of annihilating the wave reflections has been built. The obtained strategy is also discretized as a low order time-space operator for experimental implementation by using a dense network of interlaced microphones and loudspeakers. The resulting quasicollocated architecture guarantees robustness and stability margins. This paper aims at showing how a well controlled semidistributed active skin can substantially modify the sound transmissibility or reflectivity of the corresponding homogeneous passive interface. In Sec. IV, numerical and experimental results demonstrate the capabilities of such a method for controlling sound propagation in ducts. Finally, in Sec. V, an energy-based comparison with a classical open-loop strategy underlines the system's efficiency.

  5. Tookad-mediated photodynamic effects on the prostate and its adjacent tissues: in vivo study in canine models

    Science.gov (United States)

    Huang, Zheng; Chen, Qun; Luck, David; Beckers, Jill; Blanc, Dominique; Hetzel, Fred W.

    2005-04-01

    Photodynamic therapy (PDT) mediated with a vascular acting photosensitizer Tookad (pd-bacteriopheophorbide), was investigated as an alternative treatment modality for prostate cancer. Tookad photodynamic effects on the prostate and its adjacent tissues were evaluated in canine models. Interstitial prostate PDT was performed by irradiating individual lobes with a diode laser (763 nm) and 1-cm cylindrical diffuser fibers at various light doses to activate the IV administered photosensitizer Tookad (1 - 2 mg/kg). The sensitivity of the adjacent tissues to Tookad-PDT was determined by superficially irradiating the surfaces of the bladder, colon, abdominal muscle and pelvic plexus with a microlens fiber at various drug/light doses. PDT effect on the prostatic urethra was evaluated by transurethral irradiation. The prostate and adjacent tissues were harvested one-week after the treatment and subjected to histopathologic examination. At one-week post interstitial prostate PDT, the animals recovered well with little or no urethral complications. PDT induced prostate lesions were characterized by marked hemorrhagic necrosis. The bladder, colon, abdominal muscle and pelvic plexus, appeared to also be sensitive to Tookad-PDT at light dose levels greater than 40 Jcm2. Urethral mucosa appeared less sensitive to Tookad-PDT. In conclusion, Tookad-mediated PDT demonstrates very strong vascular effects and can provide an effective alternative for the treatment of localized prostate cancer. Protection of the adjacent tissues should be taken into consideration in the total prostate ablation process due to their sensitivity to the Tookad-mediated PDT.

  6. Food irradiation

    International Nuclear Information System (INIS)

    Lindqvist, H.

    1996-01-01

    This paper is a review of food irradiation and lists plants for food irradiation in the world. Possible applications for irradiation are discussed, and changes induced in food from radiation, nutritional as well as organoleptic, are reviewed. Possible toxicological risks with irradiated food and risks from alternative methods for treatment are also brought up. Ways to analyze weather food has been irradiated or not are presented. 8 refs

  7. Wideband Single Crystal Transducer for Bone Characterization, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — TRS proposes to develop a simple-to-use, launch capable, ultrasound transducer that is capable of producing the necessary bandwidth to accurately determine in vivo...

  8. Phage Pl mutants with altered transducing abilities for Escherichia coli

    International Nuclear Information System (INIS)

    Wall, J.D.; Harriman, P.D.

    1974-01-01

    A search was made for mutants of the coliphage P1 with altered transducing frequencies. A method was developed for the rapid assay of transducing frequencies in single plaques using prophage lambda as the transduced bacterial marker. This procedure selects for mutants altered in their ability to package host DNA. Mutants with 5 to 10 times higher or 10 to 20 times lower frequencies than those of wild-type P1 were found. Not only are the markers used for the detection of the mutants affected, but all other markers are similarly affected (not always to the same extent). One of the high transducing frequency mutants is a suppressible amber, indicating that loss of a function increases P1's ability to package host DNA preferentially. (U.S.)

  9. Thermal properties photonic crystal fiber transducers with ferromagnetic nanoparticles

    Science.gov (United States)

    Przybysz, N.; Marć, P.; Kisielewska, A.; Jaroszewicz, L. R.

    2015-12-01

    The main aim of the research is to design new types of fiber optic transducers based on filled photonic crystal fibers for sensor applications. In our research we propose to use as a filling material nanoparticles' ferrofluids (Fe3O4 NPs). Optical properties of such transducers are studied by measurements of spectral characteristics' changes when transducers are exposed to temperature and magnetic field changes. From synthesized ferrofluid several mixtures with different NPs' concentrations were prepared. Partially filled commercially available photonic crystal fiber LMA 10 (NKT Photonics) was used to design PCF transducers. Their thermo-optic properties were tested in a temperature chamber. Taking into account magnetic properties of synthetized NPs the patch cords based on a partially filled PM 1550 PCF were measured.

  10. Failure Analysis of High-Power Piezoelectric Transducers

    National Research Council Canada - National Science Library

    Gabrielson, T. B

    2005-01-01

    ... and stress in a piezoelectric material. For a transducer operated near resonance, there will be "hot spots" or regions of locally intense stress and electric field that precipitate premature failure...

  11. Piezoelectric textured ceramics: Effective properties and application to ultrasonic transducers.

    Science.gov (United States)

    Levassort, Franck; Pham Thi, Mai; Hemery, Henry; Marechal, Pierre; Tran-Huu-Hue, Louis-Pascal; Lethiecq, Marc

    2006-12-22

    Piezoelectric textured ceramics obtained by homo-template grain growth (HTGG) were recently demonstrated. A simple model with several assumptions has been used to calculate effective parameters of these new materials. Different connectivities have been simulated to show that spatial arrangements between the considered phases have little influence on the effective parameters, even through the 3-0 connectivity delivers the highest electromechanical thickness factor. A transducer based on a textured ceramic sample has been fabricated and characterised to show the efficiency of these piezoelectric materials. Finally, in a single element transducer configuration, simulation shows an improvement of 2 dB sensitivity for a transducer made with textured ceramic in comparison with a similar transducer design based on standard soft PZT (at equivalent bandwidths).

  12. Detection of plane, poorly oriented wide flaws using focused transducers

    International Nuclear Information System (INIS)

    Vadder, D. de; Azou, P.; Bastien, P.; Saglio, R.

    1976-01-01

    The detection of plane, poorly oriented, wide flaws by ultrasonic non destructive testing is distinctly improved when using focused transducers. An increased echo can be obtained crossing the defect limit [fr

  13. Piezoelectric transducer vibrations in a one-dimensional approximation

    CERN Document Server

    Hilke, H J

    1973-01-01

    The theory of piezoelectric transducer vibrations, which may be treated as one-dimensional, is developed in detail for thin discs vibrating in a pure thickness extensional mode. An effort has been made to obtain relations of general validity, which include losses, and which are in a simple explicit form convenient for practical calculations. The behaviour of transducers is discussed with special attention to their characteristics at the two fundamental frequencies, the so-called parallel and series resonances. Several peculiarities occur when transducers are coupled to media with considerably different acoustic impedances. These peculiarities are discussed and illustrated by numerical results for quartz and PZT 4 piezoelectric discs radiating into water, air and liquid hydrogen. The application of the theory to different types of vibrations is briefly illustrated for thin bars vibrating longitudinally. Short discussions are included on compound transducer systems, and on the properties of thin discs as receiv...

  14. Active Metamaterial Based Ultrasonic Guided Wave Transducer System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An active and tunable metamaterial phased array transducer for guided wave mode selection with high intensity per driving channel and with dramatically lower modal...

  15. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius; Kodzius, Rimantas; Vanagas, Galius

    2013-01-01

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here

  16. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius

    2013-10-22

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

  17. Performance Evaluation of Pressure Transducers for Water Impacts

    Science.gov (United States)

    Vassilakos, Gregory J.; Stegall, David E.; Treadway, Sean

    2012-01-01

    The Orion Multi-Purpose Crew Vehicle is being designed for water landings. In order to benchmark the ability of engineering tools to predict water landing loads, test programs are underway for scale model and full-scale water impacts. These test programs are predicated on the reliable measurement of impact pressure histories. Tests have been performed with a variety of pressure transducers from various manufacturers. Both piezoelectric and piezoresistive devices have been tested. Effects such as thermal shock, pinching of the transducer head, and flushness of the transducer mounting have been studied. Data acquisition issues such as sampling rate and anti-aliasing filtering also have been studied. The response of pressure transducers have been compared side-by-side on an impulse test rig and on a 20-inch diameter hemisphere dropped into a pool of water. The results have identified a range of viable configurations for pressure measurement dependent on the objectives of the test program.

  18. Preclinical studies of vascular acting photosensitizer bacteriopheophorbide for the treatment of prostate cancer

    Science.gov (United States)

    Hetzel, Fred W.; Chen, Qun; Luck, David; Beckers, Jill; Huang, Zheng

    2004-06-01

    Photodynamic therapy (PDT) mediated with vascular acting photosensitizer pd-bacteriopheophorbide (Tookad), is investigated as an alternative modality for the total ablation of prostate cancer. In vivo normal canine prostate is used as the animal model. Interstitial PDT was performed by irradiating the surgically exposed prostates with a diode laser (763 nm, 150 mW/cm) to activate the IV infused photosensitizer drug. The prostate and its adjacent tissues were harvested and subjected to histopathological examination. At one-week post PDT, the animals recovered well with little or no urethral complications. Prostatic urethra and prostate adjacent tissues (bladder and underlying colon) were well preserved. PDT induced prostate lesions were characterized by marked hemorrhagic necrosis. Prostate lesions could be detected by MRI scan as early as 48 h post PDT. Maximum lesion size of 1.5 cm3 and 2.9 cm3 could be achieved at 50 J/cm and 100 J/cm, respectively, with interstitial treatment using a single 1-cm diffuser fiber, suggesting the Tookad-PDT is very effective in ablating prostatic tissue. Pharmacokinetic studies show that the photosensitizer is cleared rapidly from the circulation. In conclusion, the novel photosensitizer Tookad mediated PDT may provide an effective alternative to treat localized prostate cancer.

  19. [Large benign prostatic hiperplasia].

    Science.gov (United States)

    Soria-Fernández, Guillermo René; Jungfermann-Guzman, José René; Lomelín-Ramos, José Pedro; Jaspersen-Gastelum, Jorge; Rosas-Nava, Jesús Emmanuel

    2012-01-01

    the term prostatic hyperplasia is most frequently used to describe the benign prostatic growth, this being a widely prevalent disorder associated with age that affects most men as they age. The association between prostate growth and urinary obstruction in older adults is well documented. large benign prostatic hyperplasia is rare and few cases have been published and should be taken into account during the study of tumors of the pelvic cavity. we report the case of an 81-year-old who had significant symptoms relating to storage and bladder emptying, with no significant elevation of prostate specific antigen. this is a rare condition but it is still important to diagnose and treat as it may be related to severe obstructive uropathy and chronic renal failure. In our institution, cases of large prostatic hyperplasia that are solved by suprapubic adenomectomy are less than 3%.

  20. [Epigenetics of prostate cancer].

    Science.gov (United States)

    Yi, Xiao-Ming; Zhou, Wen-Quan

    2010-07-01

    Prostate cancer is one of the most common malignant tumors in males, and its etiology and pathogenesis remain unclear. Epigenesis is involved in prostate cancer at all stages of the process, and closely related with its growth and metastasis. DNA methylation and histone modification are the most important manifestations of epigenetics in prostate cancer. The mechanisms of carcinogenesis of DNA methylation include whole-genome hypomethylation, aberrant local hypermethylation of promoters and genomic instability. DNA methylation is closely related to the process of prostate cancer, as in DNA damage repair, hormone response, tumor cell invasion/metastasis, cell cycle regulation, and so on. Histone modification causes corresponding changes in chromosome structure and the level of gene transcription, and it may affect the cycle, differentiation and apoptosis of cells, resulting in prostate cancer. Some therapies have been developed targeting the epigenetic changes in prostate cancer, including DNA methyltransferases and histone deacetylase inhibitors, and have achieved certain desirable results.

  1. Prostate Enlargement: Benign Prostatic Hyperplasia (BPH)

    Science.gov (United States)

    ... of substances that promote prostate cell growth. Another theory focuses on dihydrotestosterone (DHT), a male hormone that ... physical exam medical tests Personal and Family Medical History Taking a personal and family medical history is ...

  2. Finite-State Complexity and the Size of Transducers

    Directory of Open Access Journals (Sweden)

    Cristian Calude

    2010-08-01

    Full Text Available Finite-state complexity is a variant of algorithmic information theory obtained by replacing Turing machines with finite transducers. We consider the state-size of transducers needed for minimal descriptions of arbitrary strings and, as our main result, we show that the state-size hierarchy with respect to a standard encoding is infinite. We consider also hierarchies yielded by more general computable encodings.

  3. Test and evaluation of radioactively contaminated transducers and transmitters

    International Nuclear Information System (INIS)

    Strahm, R.C.

    1983-01-01

    People in the nuclear industries face some unique problems when handling, testing, or examining transducers and transmitters that have been radioactively contaminated. Although many people and organizations, including EG and G Idaho, have performed such work for many years, there are no set, structured approaches or procedures. This paper discusses a disciplined laboratory approach to contaminated transducer testing and evaluation, utilizing equipment and facilities developed specifically for this type of work

  4. A theoretical study of cylindrical ultrasound transducers for intracavitary hyperthermia

    International Nuclear Information System (INIS)

    Lin, W.-L.; Fan, W.-C.; Yen, J.-Y.; Chen, Y.-Y.; Shieh, M.-J.

    2000-01-01

    Purpose: The purpose of this paper was to examine the heating patterns and penetration depth when a cylindrical ultrasound transducer is employed for intracavitary hyperthermia treatments. Methods and Materials: The present study employs a simulation program based on a simplified power deposition model for infinitely long cylindrical ultrasound transducers. The ultrasound power in the tissue is assumed to be exponentially attenuated according to the penetration depth of the ultrasound beam, and a uniform attenuation for the entire treatment region is also assumed. The distribution of specific absorption rate (SAR) ratio (the ratio of SAR for a point within the tissue to that for a specific point on the cavity surface) is used to determine the heating pattern for a set of given parameters. The parameters considered are the ultrasound attenuation in the tissue, the cavity size, and the transducer eccentricity. Results: Simulation results show that the ultrasound attenuation in the tissue, the cavity size, and the transducer eccentricity are the most influential parameters for the distribution of SAR ratio. A low frequency transducer located in a large cavity can produce a much better penetration. The cavity size is the major parameter affecting the penetration depth for a small cavity size, such as interstitial hyperthermia. The heating pattern can also be dramatically changed by the transducer eccentricity and radiating sector. In addition, for a finite length of cylindrical transducer, lower SAR ratio appears in the regions near the applicator's edges. Conclusion: The distribution of SAR ratio indicates the relationship between the treatable region and the parameters if an appropriate threshold of SAR ratio is taken. The findings of the present study comprehend whether or not a tumor is treatable, as well as select the optimal driving frequency, the appropriate cavity size, and the eccentricity of a cylindrical transducer for a specific treatment

  5. On cribriform prostate cancer

    OpenAIRE

    Kweldam, Charlotte

    2018-01-01

    markdownabstractThis general aim of the thesis is to study the clinical relevance, interobserver reproducibility, and genetics of cribriform growth in prostate cancer. More specifically, the aims and outline of this thesis are • To study the metastatic potential of modified Gleason score 3+3 prostate cancer in radical prostatectomies. (Chapter 2) • To examine the prognostic value of individual Gleason grade 4 patterns in prostate cancer in radical prostatectomy and diagnostic biopsy specimens...

  6. Design of a Smart Ultrasonic Transducer for Interconnecting Machine Applications

    Directory of Open Access Journals (Sweden)

    Chang Xu

    2009-06-01

    Full Text Available A high-frequency ultrasonic transducer for copper or gold wire bonding has been designed, analyzed, prototyped and tested. Modeling techniques were used in the design phase and a practical design procedure was established and used. The transducer was decomposed into its elementary components. For each component, an initial design was obtained with simulations using a finite elements model (FEM. Simulated ultrasonic modules were built and characterized experimentally through the Laser Doppler Vibrometer (LDV and electrical resonance spectra. Compared with experimental data, the FEM could be iteratively adjusted and updated. Having achieved a remarkably highly-predictive FEM of the whole transducer, the design parameters could be tuned for the desired applications, then the transducer is fixed on the wire bonder with a complete holder clamping was calculated by the FEM. The approach to mount ultrasonic transducers on wire bonding machines also is of major importance for wire bonding in modern electronic packaging. The presented method can lead to obtaining a nearly complete decoupling clamper design of the transducer to the wire bonder.

  7. DESIGN AND IMPLEMENTATION OF POTENTIOMETER-BASED NONLINEAR TRANSDUCER EMULATOR

    Directory of Open Access Journals (Sweden)

    Sheroz Khan

    2011-05-01

    Full Text Available This work attempts to design and implement in hardware a transducer with a nonlinear response using potentiometer. Potentiometer is regarded as a linear transducer, while a the response of a nonlinear transducer can be treated as a concatenation of linear segments made out of the response curve of an actual nonlinear transducer at the points of inflections being exhibited by the nonlinear curve. Each straight line segment is characterized by its slope and a constant, called the y-intercept, which is ultimately realized by a corresponding electronic circuit. The complete circuit diagram is made of three stages: (i the input stage for range selection, (ii a digital logic to make appropriate selection, (iii a conditioning circuit for realizing a given straight-line segment identified by its relevant slope and reference voltage. The simulation of the circuit is carried using MULTISIM, and the designed circuit is afterward tested to verify that variations of the input voltage give us an output voltage very close to the response pattern envisaged in the analytical stage of the design. The utility of this work lies in its applications in emulating purpose built transducers that could be used to nicely emulate a transducer in a real world system that is to be controlled by a programmable digital system.

  8. Experimental Evaluation of Three Designs of Electrodynamic Flexural Transducers

    Directory of Open Access Journals (Sweden)

    Tobias J. R. Eriksson

    2016-08-01

    Full Text Available Three designs for electrodynamic flexural transducers (EDFT for air-coupled ultrasonics are presented and compared. An all-metal housing was used for robustness, which makes the designs more suitable for industrial applications. The housing is designed such that there is a thin metal plate at the front, with a fundamental flexural vibration mode at ∼50 kHz. By using a flexural resonance mode, good coupling to the load medium was achieved without the use of matching layers. The front radiating plate is actuated electrodynamically by a spiral coil inside the transducer, which produces an induced magnetic field when an AC current is applied to it. The transducers operate without the use of piezoelectric materials, which can simplify manufacturing and prolong the lifetime of the transducers, as well as open up possibilities for high-temperature applications. The results show that different designs perform best for the generation and reception of ultrasound. All three designs produced large acoustic pressure outputs, with a recorded sound pressure level (SPL above 120 dB at a 40 cm distance from the highest output transducer. The sensitivity of the transducers was low, however, with single shot signal-to-noise ratio ( SNR ≃ 15 dB in transmit–receive mode, with transmitter and receiver 40 cm apart.

  9. Damage detection in concrete structures with smart piezoceramic transducers

    Science.gov (United States)

    Naidu, Akshay S. K.; Bhalla, Suresh

    2003-10-01

    Detection of damages and progressive deterioration in structures is a critical issue. Visual inspections are tedious and unreliable. Incipient damages are often not discernible by low frequency dynamic response and other NDE techniques. Smart piezoelectric ceramic (PZT) transducers are emerging as an effective alternative in health monitoring of structures. The electro-mechanical impedance method employs the self-actuating and sensing characteristics of the PZT, without having to use actuators and sensors separately. When excited by an ac source, the PZT transducers bonded to the host structure activates the higher modes of vibration locally. Changes in the admittance response of the transducer serves as an indicator of damage around the transducer. In this paper, the effectiveness of PZT transducers for characterizing damages in concrete, in terms of the damage extent and location, is experimentally examined. The root mean square deviation (RMSD) index, adopted to quantify the changes in the admittance signatures, correlates with the damage extent. The damages on the surface that is not mounted by the PZT are also discernible. An array of transducers proves effective in detecting the damaged zone. The progressive incipient crack can be detected much before it actually becomes visible to the naked eye.

  10. Home Automation System Based on Intelligent Transducer Enablers

    Science.gov (United States)

    Suárez-Albela, Manuel; Fraga-Lamas, Paula; Fernández-Caramés, Tiago M.; Dapena, Adriana; González-López, Miguel

    2016-01-01

    This paper presents a novel home automation system named HASITE (Home Automation System based on Intelligent Transducer Enablers), which has been specifically designed to identify and configure transducers easily and quickly. These features are especially useful in situations where many transducers are deployed, since their setup becomes a cumbersome task that consumes a significant amount of time and human resources. HASITE simplifies the deployment of a home automation system by using wireless networks and both self-configuration and self-registration protocols. Thanks to the application of these three elements, HASITE is able to add new transducers by just powering them up. According to the tests performed in different realistic scenarios, a transducer is ready to be used in less than 13 s. Moreover, all HASITE functionalities can be accessed through an API, which also allows for the integration of third-party systems. As an example, an Android application based on the API is presented. Remote users can use it to interact with transducers by just using a regular smartphone or a tablet. PMID:27690031

  11. Home Automation System Based on Intelligent Transducer Enablers.

    Science.gov (United States)

    Suárez-Albela, Manuel; Fraga-Lamas, Paula; Fernández-Caramés, Tiago M; Dapena, Adriana; González-López, Miguel

    2016-09-28

    This paper presents a novel home automation system named HASITE (Home Automation System based on Intelligent Transducer Enablers), which has been specifically designed to identify and configure transducers easily and quickly. These features are especially useful in situations where many transducers are deployed, since their setup becomes a cumbersome task that consumes a significant amount of time and human resources. HASITE simplifies the deployment of a home automation system by using wireless networks and both self-configuration and self-registration protocols. Thanks to the application of these three elements, HASITE is able to add new transducers by just powering them up. According to the tests performed in different realistic scenarios, a transducer is ready to be used in less than 13 s. Moreover, all HASITE functionalities can be accessed through an API, which also allows for the integration of third-party systems. As an example, an Android application based on the API is presented. Remote users can use it to interact with transducers by just using a regular smartphone or a tablet.

  12. Home Automation System Based on Intelligent Transducer Enablers

    Directory of Open Access Journals (Sweden)

    Manuel Suárez-Albela

    2016-09-01

    Full Text Available This paper presents a novel home automation system named HASITE (Home Automation System based on Intelligent Transducer Enablers, which has been specifically designed to identify and configure transducers easily and quickly. These features are especially useful in situations where many transducers are deployed, since their setup becomes a cumbersome task that consumes a significant amount of time and human resources. HASITE simplifies the deployment of a home automation system by using wireless networks and both self-configuration and self-registration protocols. Thanks to the application of these three elements, HASITE is able to add new transducers by just powering them up. According to the tests performed in different realistic scenarios, a transducer is ready to be used in less than 13 s. Moreover, all HASITE functionalities can be accessed through an API, which also allows for the integration of third-party systems. As an example, an Android application based on the API is presented. Remote users can use it to interact with transducers by just using a regular smartphone or a tablet.

  13. Software for Correcting the Dynamic Error of Force Transducers

    Directory of Open Access Journals (Sweden)

    Naoki Miyashita

    2014-07-01

    Full Text Available Software which corrects the dynamic error of force transducers in impact force measurements using their own output signal has been developed. The software corrects the output waveform of the transducers using the output waveform itself, estimates its uncertainty and displays the results. In the experiment, the dynamic error of three transducers of the same model are evaluated using the Levitation Mass Method (LMM, in which the impact forces applied to the transducers are accurately determined as the inertial force of the moving part of the aerostatic linear bearing. The parameters for correcting the dynamic error are determined from the results of one set of impact measurements of one transducer. Then, the validity of the obtained parameters is evaluated using the results of the other sets of measurements of all the three transducers. The uncertainties in the uncorrected force and those in the corrected force are also estimated. If manufacturers determine the correction parameters for each model using the proposed method, and provide the software with the parameters corresponding to each model, then users can obtain the waveform corrected against dynamic error and its uncertainty. The present status and the future prospects of the developed software are discussed in this paper.

  14. Receive-Noise Analysis of Capacitive Micromachined Ultrasonic Transducers.

    Science.gov (United States)

    Bozkurt, Ayhan; Yaralioglu, G Goksenin

    2016-11-01

    This paper presents an analysis of thermal (Johnson) noise received from the radiation medium by otherwise noiseless capacitive micromachined ultrasonic transducer (CMUT) membranes operating in their fundamental resonance mode. Determination of thermal noise received by multiple numbers of transducers or a transducer array requires the assessment of cross-coupling through the radiation medium, as well as the self-radiation impedance of the individual transducer. We show that the total thermal noise received by the cells of a CMUT has insignificant correlation, and is independent of the radiation impedance, but is only determined by the mass of each membrane and the electromechanical transformer ratio. The proof is based on the analytical derivations for a simple transducer with two cells, and extended to transducers with numerous cells using circuit simulators. We used a first-order model, which incorporates the fundamental resonance of the CMUT. Noise power is calculated by integrating over the entire spectrum; hence, the presented figures are an upper bound for the noise. The presented analyses are valid for a transimpedance amplifier in the receive path. We use the analysis results to calculate the minimum detectable pressure of a CMUT. We also provide an analysis based on the experimental data to show that output noise power is limited by and comparable to the theoretical upper limit.

  15. High Frequency Longitudinal Damped Vibrations of a Cylindrical Ultrasonic Transducer

    Directory of Open Access Journals (Sweden)

    Mihai Valentin Predoi

    2014-01-01

    Full Text Available Ultrasonic piezoelectric transducers used in classical nondestructive testing are producing in general longitudinal vibrations in the MHz range. A simple mechanical model of these transducers would be very useful for wave propagation numerical simulations, avoiding the existing complicated models in which the real components of the transducer are modeled by finite elements. The classical model for longitudinal vibrations is not adequate because the generated longitudinal wave is not dispersive, the velocity being the same at any frequency. We have adopted the Rayleigh-Bishop model, which avoids these limitations, even if it is not converging to the first but to the second exact longitudinal mode in an elastic rod, as obtained from the complicated Pochhammer-Chree equations. Since real transducers have significant vibrations damping, we have introduced a damping term in the Rayleigh-Bishop model, increasing the imaginary part and keeping almost identical real part of the wavenumber. Common transducers produce amplitude modulated signals, completely attenuated after several periods. This can be modeled by two close frequencies, producing a “beat” phenomenon, superposed on the high damping. For this reason, we introduce a two-rod Rayleigh-Bishop model with damping. Agreement with measured normal velocity on the transducer free surface is encouraging for continuation of the research.

  16. Estrogen receptors in the human male prostatic urethra and prostate in prostatic cancer and benign prostatic hyperplasia

    DEFF Research Database (Denmark)

    Bødker, A; Bruun, J; Balslev, E

    1999-01-01

    Estrogen receptors (ERs) in the prostate and prostatic urethra were examined in 33 men with benign prostatic hyperplasia (BPH) and in 11 with prostate cancer (PC). The Abbot monoclonal ER-ICA assay was used for immunohistochemical investigation. In the BPH group, ERs were revealed in the prostatic...... stroma in eight cases and in the glandular epithelium in one. In four cases ERs were seen in the prostatic stroma and in the glandular epithelium. In the prostatic urethra, ERs were found in 19 cases located in the urothelium, lamina propria and/or periurethral glands. In the PC group, ERs were...... demonstrated in the prostatic stroma and/or prostatic urethra in 6 out of 11 cases. In both BPH and PC patients, immunoreactivity was weak and confined to few cells, indicating low ER content in the prostate as well as in the prostatic urethra. Dextran-coated charcoal (DCC) analysis was used for detection...

  17. Prostate imaging. An update

    International Nuclear Information System (INIS)

    Franiel, T.; Teichgraeber, U.; Asbach, P.; Hamm, B.; Foller, S.

    2015-01-01

    New technical and clinical developments of sonography and magnetic resonance imaging include improved detection, localization and staging as well as active surveillance of prostate cancer. Multiparametric MRI can best answer these typical clinical questions. However, ultrasound elastography seems to be suitable for the detection of significant prostate cancer as well. The structured reporting system for multiparametric MRI of the prostate according to PI-RADS Version 1 led to improved and reproducible diagnosis of prostate cancer. The new PI-RADS Version 2 aims to minimize the limitations of Version 1 and make PI-RADS standardization more globally acceptable.

  18. Food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gruenewald, T

    1985-01-01

    Food irradiation has become a matter of topical interest also in the Federal Republic of Germany following applications for exemptions concerning irradiation tests of spices. After risks to human health by irradiation doses up to a level sufficient for product pasteurization were excluded, irradiation now offers a method suitable primarily for the disinfestation of fruit and decontamination of frozen and dried food. Codex Alimentarius standards which refer also to supervision and dosimetry have been established; they should be adopted as national law. However, in the majority of cases where individual countries including EC member-countries so far permitted food irradiation, these standards were not yet used. Approved irradiation technique for industrial use is available. Several industrial food irradiation plants, partly working also on a contractual basis, are already in operation in various countries. Consumer response still is largely unknown; since irradiated food is labelled, consumption of irradiated food will be decided upon by consumers.

  19. Localization of the prostatic apex for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Wilder, Richard B.; Fone, Patricia D.; Jones, C. Darryl; White, Ralph DeVere

    1996-01-01

    Purpose/Objective: There is no consensus on the optimal method for localizing the prostatic apex in patients with early stage adenocarcinoma of the prostate. Some radiation oncologists have recommended that transrectal ultrasound or MRI scans be used to define the inferior border of radiation portals. The purpose of this prospective study is to assess the ability of retrograde urethrograms and CT scans to accurately define the prostatic apex in the craniocaudad dimension, using urethroscopy as a reference. Materials and Methods: Following construction of an Alpha cradle, plain radiographs of the pelvis were obtained in 15 patients with early stage adenocarcinoma of the prostate, with the tip of a urethroscope placed at the superior border of the external sphincter (which most closely approximates the prostatic apex). The scope was then withdrawn, and a retrograde urethrogram was performed. Immediately afterwards, a treatment planning CT scan of the pelvis was obtained. Since differential filling of the bladder and rectum affects the position of the prostatic apex, patients voided prior to rather than in between the 3 consecutive studies. Results: The urethroscopy-defined prostatic apex was located 28 ± 3 mm (mean ± SE) superior to the ischial tuberosities, 12 ± 1 mm (mean ± SE) superior to the urethrogram tip and 8 ± 2 mm (mean ± SE) superior to the CT-defined apex. Placement of the inferior border of the radiation portals at the ischial tuberosities would have resulted in irradiation of > 20 mm membranous and spongy urethra in all of the patients. Conclusion: Retrograde urethrograms provide more helpful information than CT scans with regard to localization of the prostatic apex and are more cost effective than sonograms or MRI scans. The prostatic apex is typically 12 mm superior to the urethrogram tip with little variability. Retrograde urethrograms allow one to spare as much urethra as possible in the radiation portals, which should theoretically reduce

  20. Review article: Prostate cancer screening using prostate specific ...

    African Journals Online (AJOL)

    Background: Prostate cancer is the commonest cancer among men in Nigeria and early detection is key to cure and survival but its screening through prostate specific antigen (PSA) has remain controversial in literature. Screening with prostate specific antigen (PSA) has led to more men diagnosed with prostate cancer than ...

  1. A 63 element 1.75 dimensional ultrasound phased array for the treatment of benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    Smith Nadine

    2005-06-01

    Full Text Available Abstract Background Prostate cancer and benign prostatic hyperplasia are very common diseases in older American men, thus having a reliable treatment modality for both diseases is of great importance. The currently used treating options, mainly surgical ones, have numerous complications, which include the many side effects that accompany such procedures, besides the invasive nature of such techniques. Focused ultrasound is a relatively new treating modality that is showing promising results in treating prostate cancer and benign prostatic hyperplasia. Thus this technique is gaining more attention in the past decade as a non-invasive method to treat both diseases. Methods In this paper, the design, construction and evaluation of a 1.75 dimensional ultrasound phased array to be used for treating prostate cancer and benign prostatic hyperplasia is presented. With this array, the position of the focus can be controlled by changing the electrical power and phase to the individual elements for electronically focusing and steering in a three dimensional volume. The array was designed with a maximum steering angle of ± 13.5° in the transverse direction and a maximum depth of penetration of 11 cm, which allows the treatment of large prostates. The transducer piezoelectric ceramic, matching layers and cable impedance have been designed for maximum power transfer to tissue. Results To verify the capability of the transducer for focusing and steering, exposimetry was performed and the results correlated well with the calculated field. Ex vivo experiments using bovine tissue were performed with various lesion sizes and indicated the capability of the transducer to ablate tissue using short sonications. Conclusion A 1.75 dimensional array, that overcame the drawbacks associated with one-dimensional arrays, has been designed, built and successfully tested. Design issues, such as cable and ceramic capacitances, were taken into account when designing this

  2. Appearance and methods of prostatic arteriography

    International Nuclear Information System (INIS)

    Chang Gang; Yang Zhigang; Meng Fanzhe; Zhang Yingguang; Chen Zhiqiang; Yang Ming

    2004-01-01

    Objective: To study the methods of prostatic arteriography and evaluate the arteriographic appearance of prostatic blood supply. Methods: Selective and super-selective prostatic arteriographies were performed in 62 patients with benign prostatic hyperplasia and prostatic cancer. Results: The prostatic blood supply originated mainly from inferior vesical artery or internal pudendal artery or prostatic artery (80%). Prostatic arteriography could be performed successfully with skillful catheterization and high resolution DSA. Conclusions: Prostatic arteriography is helpful for evaluating the origin and quantity of prostate vasculature and important to differentiate benign prostatic hyperplasia from prostatic cancer

  3. Studies of vascular acting photosensitizer Tookad for the photodynamic therapy of prostate cancer

    Science.gov (United States)

    Huang, Zheng; Chen, Qun; Blanc, Dominique; Hetzel, Fred W.

    2005-01-01

    In this pre-clinical study, photodynamic therapy (PDT) mediated with a vascular acting photosensitizer Tookad (palladium-bacteriopheophorbide) is investigated as an alternative treatment modality for the ablation of prostate cancer. Canine prostate was used as the animal model. PDT was performed by interstitially irradiating the surgically exposed prostates with a diode laser (763 nm) to activate the IV infused photosensitizer. The effects of drug dose, drug-light interval, and light fluence rate on PDT efficacy were evaluated. The prostates and adjacent tissues were harvested at one-week post PDT and subjected to histopathological examination. The dogs recovered well with little or no urethral complications. Urinalysis showed trace blood. Histological examination showed minimal damage to the prostatic urethra. These indicated that the urethra was well preserved. PDT induced prostate lesions were characterized by marked hemorrhagic necrosis with a clear demarcation. Maximum lesion volume of ~3 cm3 could be achieved with a single 1-cm diffuser fiber at a dose level of 1 mg/kg and 200 J/cm, suggesting the therapy is very effective in ablating prostatic tissue. PDT induced lesion could reach the capsule layers but adjacent tissues were well preserved. The novel photosensitizer is a vascular drug and cleared rapidly from the circulation. Light irradiation can be performed during drug infusion thereby eliminating waiting time. The novel vascular acting photosensitizer Tookad-mediated PDT could provide an effective alternative to treat prostate cancer.

  4. Development and research of in-core transducers at IAE (Institute of Atomic Energy)

    International Nuclear Information System (INIS)

    Huang Yucai; Qian Shunfa; Jia Guozhen

    1989-10-01

    The development of in-core transducers at IAE (Institute of Atomic Energy) and their applications in in-pile fuel assembly test are mentioned. These transducers include mainly tubed tungsten-rhenium thermocouple assembly, displacement transducer of linear variable differential transformer, pressure transducer of membrane type, gamma thermometer, turbine flow meter, self-powered neutron detector etc

  5. Immersion apparatus and process for an ultrasonic transducer in a liquid metal

    International Nuclear Information System (INIS)

    Le Baud, P.

    1987-01-01

    The ultrasonic transducer is introduced in a casing. The coupling zone of the transducer is covered by a layer of liquid metal. This layer is solidified and then the transducer with his coating layer is introduced in the liquid metal under an inert atmosphere. The device for immersing the transducer is claimed [fr

  6. Highly directional transurethral ultrasound applicators with rotational control for MRI-guided prostatic thermal therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Anthony B [Thermal Therapy Research Group, UCSF Radiation Oncology, San Francisco, CA (United States); Diederich, Chris J [Thermal Therapy Research Group, UCSF Radiation Oncology, San Francisco, CA (United States); Nau, William H [Thermal Therapy Research Group, UCSF Radiation Oncology, San Francisco, CA (United States); Gill, Harcharan [Department of Urology, Stanford University, Stanford, CA (United States); Bouley, Donna M [Department of Comparative Medicine, Stanford University, Stanford, CA (United States); Daniel, Bruce [Department of Radiology, Stanford University, Stanford, CA (United States); Rieke, Viola [Department of Radiology, Stanford University, Stanford, CA (United States); Butts, R Kim [Department of Radiology, Stanford University, Stanford, CA (United States); Sommer, Graham [Department of Radiology, Stanford University, Stanford, CA (United States)

    2004-01-21

    Transurethral ultrasound applicators with highly directional energy deposition and rotational control were investigated for precise treatment of benign prostatic hyperplasia (BPH) and adenocarcinoma of the prostate (CaP). Two types of catheter-based applicators were fabricated, using either sectored tubular (3.5 mm OD x 10 mm) or planar transducers (3.5 mm x 10 mm). They were constructed to be MRI compatible, minimally invasive and allow for manual rotation of the transducer array within a 10 mm cooling balloon. In vivo evaluations of the applicators were performed in canine prostates (n 3) using MRI guidance (0.5 T interventional magnet). MR temperature imaging (MRTI) utilizing the proton resonance frequency shift method was used to acquire multiple-slice temperature overlays in real time for monitoring and guiding the thermal treatments. Post-treatment T1-weighted contrast-enhanced imaging and triphenyl tetrazolium chloride stained tissue sections were used to define regions of tissue coagulation. Single sonications with the tubular applicator ) produced coagulated zones covering a wedge of the prostate extending from 1-2 mm outside the urethra to the outer boundary of the gland (16 mm radial coagulation). Single sonications with the planar applicator (15-20 W, 10 min, {approx}8 MHz) generated thermal lesions of {approx}30 extending to the prostate boundary. Multiple sequential sonications (sweeping) of a planar applicator (12 W with eight rotations of 30 each) demonstrated controllable coagulation of a 270 contiguous section of the prostate extending to the capsule boundary. The feasibility of using highly directional transurethral ultrasound applicators with rotational capabilities to selectively coagulate regions of the prostate while monitoring and controlling the treatments with MRTI was demonstrated in this study.

  7. Postoperative Intensity Modulated Radiation Therapy in High Risk Prostate Cancer: A Dosimetric Comparison

    International Nuclear Information System (INIS)

    Digesu, Cinzia; Cilla, Savino; De Gaetano, Andrea; Massaccesi, Mariangela; Macchia, Gabriella; Ippolito, Edy; Deodato, Francesco; Panunzi, Simona; Iapalucci, Chiara; Mattiucci, Gian Carlo; D'Angelo, Elisa; Padula, Gilbert D.A.; Valentini, Vincenzo; Cellini, Numa

    2011-01-01

    The aim of this study was to compare intensity-modulated radiation therapy (IMRT) with 3D conformal technique (3D-CRT), with respect to target coverage and irradiation of organs at risk for high dose postoperative radiotherapy (PORT) of the prostate fossa. 3D-CRT and IMRT treatment plans were compared with respect to dose to the rectum and bladder. The dosimetric comparison was carried out in 15 patients considering 2 different scenarios: (1) exclusive prostate fossa irradiation, and (2) pelvic node irradiation followed by a boost on the prostate fossa. In scenario (1), a 3D-CRT plan (box technique) and an IMRT plan were calculated and compared for each patient. In scenario (2), 3 treatment plans were calculated and compared for each patient: (a) 3D-CRT box technique for both pelvic (prophylactic nodal irradiation) and prostate fossa irradiation (3D-CRT only); (b) 3D-CRT box technique for pelvic irradiation followed by an IMRT boost to the prostatic fossa (hybrid 3D-CRT and IMRT); and (c) IMRT for both pelvic and prostate fossa irradiation (IMRT only). For exclusive prostate fossa irradiation, IMRT significantly reduced the dose to the rectum (lower Dmean, V50%, V75%, V90%, V100%, EUD, and NTCP) and the bladder (lower Dmean, V50%, V90%, EUD and NTCP). When prophylactic irradiation of the pelvis was also considered, plan C (IMRT only) performed better than plan B (hybrid 3D-CRT and IMRT) as respect to both rectum and bladder irradiation (reduction of Dmean, V50%, V75%, V90%, equivalent uniform dose [EUD], and normal tissue complication probability [NTCP]). Plan (b) (hybrid 3D-CRT and IMRT) performed better than plan (a) (3D-CRT only) with respect to dose to the rectum (lower Dmean, V75%, V90%, V100%, EUD, and NTCP) and the bladder (Dmean, EUD, and NTCP). Postoperative IMRT in prostate cancer significantly reduces rectum and bladder irradiation compared with 3D-CRT.

  8. Imaging of the prostate

    International Nuclear Information System (INIS)

    Turgut, A.

    2012-01-01

    Full text: The main role of imaging in prostatic diseases is for prostate cancer. Transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) are the most commonly used imaging tools used for the diagnosis of the diseases of the prostate gland. The main indications for TRUS is the evaluation for prostate cancer and guidance for prostate biopsy. On TRUS, the transition zone with a hypoechoic appearance can be differentiated from the peripheral zone, which appears relatively echogenic and homogenous in echotexture. Prostate cancer mainly involves the peripheral zone, though one fifth of the disease can be detected in the transition zone, which is the major site for hyperplastic changes in older men. Color Doppler ultrasound may be helpful for the differentiation of low-risk, hypovascular tumors from high-risk, hypervascular tumors, as the latter group is associated with higher Gleason tumor grades consistent with higher risk for extraprostatic spread. Nevertheless, targeted prostate biopsy solely based on high-frequency color or power Doppler imaging is not recommended, as the technique has inherent risk of missing a significant number of cancers. Although power Doppler ultrasound can enable the operator to perform more accurate sampling of the prostate by determining sites of focal hypervascularity, it has not been found to be superior to color Doppler ultrasound. It has been reported to be useful only for targeted biopsies with limited number of biopsy cores. Microbubble contrast agents may enable better visualization of prostatic microvasculature and cancerous prostate tissue. By means of contrast-enhanced ultrasound (CEUS), the number of cores may be decreased by performing targeted biopsies. Importantly, the detection of the signals reflected by the microbubbles can be enhanced by the phase inversion (pulse-inversion) technology. Prostate cancer appears as a dark zone on elastography representing limited elasticity or compressibility. By means of the

  9. Radiation therapy for localized prostate cancer

    International Nuclear Information System (INIS)

    Taylor, W.J.; Richardson, G.; Hafermann, M.D.

    1979-01-01

    Since 1965, 401 patients with prostate cancer have received intensive local pelvic radiation therapy at the Virginia Mason Medical Center. Two hundred twenty-one of this series were in the Stage C category. The 36 Stage B cancers were either medically nonoperable, or advanced extent, or had high-grade histopathology. Ten patients each were in diffuse Stage A or Stage D groups, the latter receiving local palliative inensive treatment to the prostate area. The mean age of the patients was 67.6 years. The five year survival of the Stage C group was 57.7%. There was no apparent influence on the survival of irradiated Stage C patients who received estrogen therapy. Current treatment techniques employ 10 megavolt photon beam with whole pelvic nodal fields and bilateral are rotational boost fields. The incidence of reactions and complications is presented

  10. Prostate cancer: Doses and volumes of radiotherapy

    International Nuclear Information System (INIS)

    Hennequin, C.; Rivera, S.; Quero, L.; Latorzeff, I.

    2010-01-01

    Radiotherapy is nowadays a major therapeutic option in prostate cancer. Technological improvements allowed dose escalation without increasing late toxicity. Some randomized trials have shown that dose escalation decreases the biochemical failure rate, without any benefit in survival with the present follow-up. However, some studies indicate that the distant metastases rate is also decreased. Most of these studies have been done without hormonal treatment, and the role of dose escalation in case of long-term androgen deprivation is unknown. The target volume encompassed the whole gland: however, complete or partial focal treatment of the prostate can be done with sophisticated IMRT technique and must be evaluated. Proximal part of the seminal vesicles must be included in the target volumes. The role of nodal irradiation is another debate, but it could be logically proposed for the unfavourable group. (authors)

  11. Conformal treatment of prostate cancer with improved targeting: superior prostate-specific antigen response compared to standard treatment

    Energy Technology Data Exchange (ETDEWEB)

    Corn, Benjamin W; Hanks, Gerald E; Schultheiss, Timothy E; Hunt, Margie A; Lee, W Robert; Coia, Lawrence R

    1995-05-15

    Purpose: Conformal radiation therapy (CRT) decreases the morbidity of prostate cancer treatment, but no published data attest to the improved ability of CRT to control disease. Therefore, we compared Prostate-Specific Antigen (PSA) response at 1 year among similarly staged patients treated by conformal techniques to those treated with conventional approaches, looking for an early indicator of tumor response. Method and Materials: Patients with locally advanced disease were treated by pelvic fields followed by prostate field conedowns; those with early stage/low grade disease received only prostate field irradiation. Between October, 1987 and November, 1991, conventional treatments used rectangular beams with or without corner blocks. Neither urethrography nor immobilization casts were used for conventionally treated patients. Between April, 1989 and December, 1992, conformal treatments have used rigid immobilization and Computed Tomography-based, beams-eye-view field design. As such, our conformal approach allowed improved targeting. Median prescribed doses (minimal doses to the Planning Target Volume) were 70 Gy (66-73 Gy) and 70.2 Gy (64.8-75 Gy) for conventionally and conformally treated patients, respectively. Median daily fraction size was 1.8 Gy for conventional treatment and 2.0 Gy for conformal therapy. Baseline PSA data were available on 170 consecutive patients treated conformally and 90 consecutive patients treated conventionally. Results: Among those receiving only prostatic field irradiation, 12-month PSA values returned to normal in 96% and 85% of conformally and conventionally treated patients, respectively, when normalization was defined as {<=} 4 ng/ml (p < 0.03) and in 76% vs. 55% of patients when PSA normalization was defined as {<=} 1.5 ng/ml (p < 0.02). Among those receiving pelvic irradiation prior to prostatic conedown, PSA normalization ({<=} 4 ng/ml) occurred in 82% and 61% (p < 0.01) of conformally and conventionally treated patients

  12. Food irradiation

    International Nuclear Information System (INIS)

    Sato, Tomotaro; Aoki, Shohei

    1976-01-01

    Definition and significance of food irradiation were described. The details of its development and present state were also described. The effect of the irradiation on Irish potatoes, onions, wiener sausages, kamaboko (boiled fish-paste), and mandarin oranges was evaluated; and healthiness of food irradiation was discussed. Studies of the irradiation equipment for Irish potatoes in a large-sized container, and the silo-typed irradiation equipment for rice and wheat were mentioned. Shihoro RI center in Hokkaido which was put to practical use for the irradiation of Irish potatoes was introduced. The state of permission of food irradiation in foreign countries in 1975 was introduced. As a view of the food irradiation in the future, its utilization for the prevention of epidemics due to imported foods was mentioned. (Serizawa, K.)

  13. The Prostate Exam

    Science.gov (United States)

    Romero, Frederico R.; Romero, Antonio W.; Filho, Thadeu Brenny; Kulysz, David; Oliveira, Fernando C., Jr.; Filho, Renato Tambara

    2012-01-01

    Objective: To help students, residents, and general practitioners to improve the technique, skills, and reproducibility of their prostate examination. Methods: We developed a comprehensive guideline outlining prostate anatomy, indications, patient preparation, positioning, technique, findings, and limitations of this ancient art of urological…

  14. Tuberculous prostatitis: mimicking a cancer.

    Science.gov (United States)

    Aziz, El Majdoub; Abdelhak, Khallouk; Hassan, Farih Moulay

    2016-01-01

    Genitourinary tuberculosis is a common type of extra-pulmonary tuberculosis . The kidneys, ureter, bladder or genital organs are usually involved. Tuberculosis of the prostate has mainly been described in immune-compromised patients. However, it can exceptionally be found as an isolated lesion in immune-competent patients. Tuberculosis of the prostate may be difficult to differentiate from carcinoma of the prostate and the chronic prostatitis when the prostate is hard and nodular on digital rectal examination and the urine is negative for tuberculosis bacilli. In many cases, a diagnosis of tuberculous prostatitis is made by the pathologist, or the disease is found incidentally after transurethral resection. Therefore, suspicion of tuberculous prostatitis requires a confirmatory biopsy of the prostate. We report the case of 60-year-old man who presented a low urinary tract syndrome. After clinical and biological examination, and imaging, prostate cancer was highly suspected. Transrectal needle biopsy of the prostate was performed and histological examination showed tuberculosis lesions.

  15. Gamma irradiator

    International Nuclear Information System (INIS)

    Simonet, G.

    1986-09-01

    Fiability of devices set around reactors depends on material resistance under irradiation noticeably joints, insulators, which belongs to composition of technical, safety or physical incasurement devices. The irradiated fuel elements, during their desactivation in a pool, are an interesting gamma irradiation device to simulate damages created in a nuclear environment. The existing facility at Osiris allows to generate an homogeneous rate dose in an important volume. The control of the element distances to irradiation box allows to control this dose rate [fr

  16. Food irradiation

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The article explains what radiation does to food to preserve it. Food irradiation is of economic importance to Canada because Atomic Energy of Canada Limited is the leading world supplier of industrial irradiators. Progress is being made towards changing regulations which have restricted the irradiation of food in the United States and Canada. Examples are given of applications in other countries. Opposition to food irradiation by antinuclear groups is addressed

  17. Biochemical failure after radical external beam radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Nomoto, Satoshi; Imada, Hajime; Kato, Fumio; Yahara, Katsuya; Morioka, Tomoaki; Ohguri, Takayuki; Nakano, Keita; Korogi, Yukunori

    2005-01-01

    The purpose of this study was to evaluate biochemical failures after radical external beam radiotherapy for prostate cancer. A total of 143 patients with prostate cancer (5 cases in stage A2, 95 in stage B and 43 in stage C; 18 in low risk group, 37 in intermediate risk group, 67 in high risk group and 21 in unknown group) were included in this study. Patients of stage A2 and B underwent external irradiation of 46 Gy to the prostate gland and seminal vesicle and additional 20 Gy to the prostate gland, while patients of stage C underwent external irradiation of 66 Gy to the prostate gland and seminal vesicle including 46 Gy to the pelvis. Neoadjuvant hormonal therapy was done in 66 cases, and long-term hormonal therapy in 75 cases; two cases were treated with radiation therapy alone. The 3-year relapse free survival rates by stage A2, B and C were 100%, 96.7% and 88.1%, respectively. The 3-year relapse free survival rates by low, intermediate and high risk groups were 100%, 92.3% and 89.7%, respectively. Biochemical failure was noted in nine cases during the average observation term of 32.2 months; in this group the median of prostate specific antigen (PSA) value was 2.6 ng/ml, the doubling time was 8.6 months, and the term of biochemical failure was 33.2 months. Six of eight cases with biochemical failure were the neoadjuvant hormonal therapy group, but biochemical no evidence of disease (bNED) curve showed no significant difference between neoadjuvant and long-term hormonal groups. It is supposed that unnecessary hormonal therapies were performed based on the nonspecific diagnosis of biochemical failure after radical radiotherapy in our group of patients. A precise criterion of biochemical failure after radical radiotherapy for prostate cancer is necessary. (author)

  18. Food irradiation

    International Nuclear Information System (INIS)

    Beyers, M.

    1977-01-01

    The objectives of food irradiation are outlined. The interaction of irradiation with matter is then discussed with special reference to the major constituents of foods. The application of chemical analysis in the evaluation of the wholesomeness of irradiated foods is summarized [af

  19. Prostate cancer epigenome.

    Science.gov (United States)

    Chinaranagari, Swathi; Sharma, Pankaj; Bowen, Nathan J; Chaudhary, Jaideep

    2015-01-01

    Prostate cancer is a major health burden within the ever-increasingly aging US population. The molecular mechanisms involved in prostate cancer are diverse and heterogeneous. In this context, epigenetic changes, both global and gene specific, are now an emerging alternate mechanism in disease initiation and progression. The three major risk factors in prostate cancer: age, geographic ancestry, and environment are all influenced by epigenetics and additional significant insight is required to gain an understanding of the underlying mechanisms. The androgen receptor and its downstream effector pathways, central to prostate cancer initiation and progression, are subject to a multitude of epigenetic alterations. In this review we focus on the global perspective of epigenetics and the use of recent next-generation sequencing platforms to interrogate epigenetic changes in the prostate cancer genome.

  20. Design of a saturated analogue and digital current transducer

    International Nuclear Information System (INIS)

    Pross, Alexander

    2002-01-01

    This project describes the development of a new analogue and digital current transducer, providing a range of new theoretical design methods for these novel devices. The main control feature is the limit cycling operation, and the novel use of the embedded sigma-delta modulator sensor structure to derive a low component count digital sensor. The research programme was initiated into the design, development and evaluation of a novel non-Hall sensing analogue and digital current transducer. These transducers are used for measurement of high currents in power systems applications. The investigation is concerned with a new design which uses a magnetic ferrite core without an air gap for current measurement. The motivation for this work was to design a new control circuit which provides a low component count, and utilises the non-linear properties of the magnetic ferrite core to transmit direct current. The use of a limit cycle control circuit was believed to be particularly suitable for the analogue and digital transducers, for two main reasons: the low component count, and the output signal is directly digital. In line with the motivations outlined above, the outcome of the research has witnessed the design, development and evaluation of a practically realisable analogue and digital current transducer. The design procedure, which is documented in this thesis, is considered to be a major contribution to the field of transducers design and development using a control systems approach. Mathematical models for both analogue and digital transducers were developed and the resulting model based predictions were found to be in good agreement with measured results. Simplification of the new model sensing device was achieved by approximating the non-linear ferrite core using FFT analysis. This is also considered to be a significant contribution. The development analogue and digital current censors employed a sampled data control systems design and utilised limit cycling

  1. Permanent Prostate Brachytherapy in Prostate Glands 3

    International Nuclear Information System (INIS)

    Mayadev, Jyoti; Merrick, Gregory S.; Reed, Joshua R.; Butler, Wayne M.; Galbreath, Robert W.; Allen, Zachariah A.; Wallner, Kent E.

    2010-01-01

    Purpose: To investigate the dosimetry, treatment-related morbidity, and biochemical outcomes for brachytherapy in patients with prostate glands 3 . Methods and Materials: From November 1996 to October 2006, 104 patients with prostate glands 3 underwent brachytherapy. Multiple prostate, urethral, and rectal dosimetric parameters were evaluated. Treatment-related urinary and rectal morbidity were assessed from patient questionnaires. Cause-specific survival, biochemical progression-free survival, and overall survival were recorded. Results: The median patient age, follow up, and pre-treatment ultrasound volume was 64 years, 5.0 years and 17.6cm 3 , respectively. Median day 0 dosimetry was significant for the following: V100 98.5%, D90 126.1% and R100 <0.5% of prescription dose. The mean urethral and maximum urethral doses were 119.6% and 133.8% of prescription. The median time to International Prostate Symptom Score resolution was 4 months. There were no RTOG grade III or IV rectal complications. The cause-specific survival, biochemical progression-free survival, and overall survival rates were 100%, 92.5%, and 77.8% at 9 years. For biochemically disease-free patients, the median most recent postbrachytherapy PSA value was 0.02 ng/mL. Conclusion: Our results demonstrate that brachytherapy for small prostate glands is highly effective, with an acceptable morbidity profile, excellent postimplant dosimetry, acceptable treatment-related morbidity, and favorable biochemical outcomes.

  2. Multiple single-element transducer photoacoustic computed tomography system

    Science.gov (United States)

    Kalva, Sandeep Kumar; Hui, Zhe Zhi; Pramanik, Manojit

    2018-02-01

    Light absorption by the chromophores (hemoglobin, melanin, water etc.) present in any biological tissue results in local temperature rise. This rise in temperature results in generation of pressure waves due to the thermoelastic expansion of the tissue. In a circular scanning photoacoustic computed tomography (PACT) system, these pressure waves can be detected using a single-element ultrasound transducer (SUST) (while rotating in full 360° around the sample) or using a circular array transducer. SUST takes several minutes to acquire the PA data around the sample whereas the circular array transducer takes only a fraction of seconds. Hence, for real time imaging circular array transducers are preferred. However, these circular array transducers are custom made, expensive and not easily available in the market whereas SUSTs are cheap and readily available in the market. Using SUST for PACT systems is still cost effective. In order to reduce the scanning time to few seconds instead of using single SUST (rotating 360° ), multiple SUSTs can be used at the same time to acquire the PA data. This will reduce the scanning time by two-fold in case of two SUSTs (rotating 180° ) or by four-fold and eight-fold in case of four SUSTs (rotating 90° ) and eight SUSTs (rotating 45° ) respectively. Here we show that with multiple SUSTs, similar PA images (numerical and experimental phantom data) can be obtained as that of PA images obtained using single SUST.

  3. A piezoelectric transducer for measurement of dynamic strain in pipes

    Energy Technology Data Exchange (ETDEWEB)

    Lannes, Daniel P.; Gama, Antonio L. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica

    2009-07-01

    This work presents a new strain transducer developed mainly for the inspection and evaluation of piping systems with excessive vibration. Vibration is one of the most common causes of piping failures. These failures could be avoided if the vibration problems were identified and quickly evaluated. Procedures for evaluation of piping vibration are usually based on pipe velocity or displacement. Although simple and fast, these procedures do not provide precise information on the risk of piping fatigue failure. Through the measurement of pipe dynamic strains the risk of failure due to vibration can be determined more accurately. The measurement of strain is usually performed using the conventional strain gauge method. Although efficient and accurate, the implementation of the conventional strain gauge technique may become a difficult task in certain industrial scenarios. Motivated by the need of a simple and rapid method for pipe dynamic strain measurement, a piezoelectric dynamic strain transducer was developed. This work presents a description of the piezoelectric strain transducer and the preliminary results of pipe strain measurements. The transducer can be applied directly to the pipe through magnetic bases allowing for the quick measurement of the dynamic strains in many points of the pipe. The transducer signal can be read with the same commercial data collectors used for accelerometers. (author)

  4. Transducer selection and application in magnetoacoustic tomography with magnetic induction

    International Nuclear Information System (INIS)

    Zhou, Yuqi; Wang, Jiawei; Ma, Qingyu; Sun, Xiaodong; Zhang, Dong

    2016-01-01

    As an acoustic receiver, transducer plays a vital role in signal acquisition and image reconstruction for magnetoacoustic tomography with magnetic induction (MAT-MI). In order to optimize signal acquisition, the expressions of acoustic pressure detection and waveform collection are theoretically studied based on the radiation theory of acoustic dipole and the reception pattern of transducer. Pressure distributions are simulated for a cylindrical phantom model using a planar piston transducer with different radii and bandwidths. The proposed theory is also verified by the experimental measurements of acoustic waveform detection for an aluminum foil cylinder. It is proved that acoustic pressure with sharp and clear boundary peaks can be detected by the large-radius transducer with wide bandwidth, reflecting the differential of the induced Lorentz force accurately, which is helpful for precise conductivity reconstruction. To detect acoustic pressure with acceptable pressure amplitude, peak pressure ratio, amplitude ratio, and improved signal to noise ratio, the scanning radius of 5–10 times the radius of the object should be selected to improve the accuracy of image reconstruction. This study provides a theoretical and experimental basis for transducer selection and application in MAT-MI to obtain reconstructed images with improved resolution and definition.

  5. Transducer selection and application in magnetoacoustic tomography with magnetic induction

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yuqi; Wang, Jiawei; Ma, Qingyu, E-mail: maqingyu@njnu.edu.cn [Key Laboratory of Optoelectronics of Jiangsu Province, School of Physics and Technology, Nanjing Normal University, Nanjing 210023 (China); Sun, Xiaodong [China Key System & Integrated Circuit Co., Ltd., Wuxi 214072 (China); Zhang, Dong [Laboratory of Modern Acoustics of MOE, Institute of Acoustics, Nanjing University, Nanjing 210093 (China)

    2016-03-07

    As an acoustic receiver, transducer plays a vital role in signal acquisition and image reconstruction for magnetoacoustic tomography with magnetic induction (MAT-MI). In order to optimize signal acquisition, the expressions of acoustic pressure detection and waveform collection are theoretically studied based on the radiation theory of acoustic dipole and the reception pattern of transducer. Pressure distributions are simulated for a cylindrical phantom model using a planar piston transducer with different radii and bandwidths. The proposed theory is also verified by the experimental measurements of acoustic waveform detection for an aluminum foil cylinder. It is proved that acoustic pressure with sharp and clear boundary peaks can be detected by the large-radius transducer with wide bandwidth, reflecting the differential of the induced Lorentz force accurately, which is helpful for precise conductivity reconstruction. To detect acoustic pressure with acceptable pressure amplitude, peak pressure ratio, amplitude ratio, and improved signal to noise ratio, the scanning radius of 5–10 times the radius of the object should be selected to improve the accuracy of image reconstruction. This study provides a theoretical and experimental basis for transducer selection and application in MAT-MI to obtain reconstructed images with improved resolution and definition.

  6. Piezoelectric Polymer Ultrasound Transducers and Its Biomedical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kang Lyeol; Cao, Yanggang [Department of Physics, Pukyong National University, Busan (Korea, Republic of)

    2012-10-15

    PVDF(poly vinylidene fluoride) and P(VDF-TrFE)(poly vinylidene fluoride-tetrafluoroethylene) are the typical piezoelectric polymers with unique properties. Even they are inferior to conventional piezoelectric ceramics PZT in electromechanical conversion efficiency and interior loss, though they are superior in receiving sensitivity and frequency bandwidth. Their acoustic impedances are relatively close to water or biological tissue and it is easier to make thin film than other piezoelectric materials. Furthermore, the film is so flexible that it is easy to attach on a complex surface. Those properties are suitable for the ultrasound transducers which are useful for medical and biological application, so that various types of polymer transducers have been developed. In this paper, several important considerations for design and fabrication of piezoelectric polymer transducers were described and their effect on the transducer performance were demonstrated through the KLM model analysis. Then, it was briefly reviewed about the structures of the polymer transducers developed for obtaining images as well as the characteristics of the images in several important medical and biological application fields.

  7. A new hybrid longitudinal–torsional magnetostrictive ultrasonic transducer

    International Nuclear Information System (INIS)

    Karafi, Mohammad Reza; Hojjat, Yousef; Sassani, Farrokh

    2013-01-01

    In this paper, a novel hybrid longitudinal–torsional magnetostrictive ultrasonic transducer (HL–TMUT) is introduced. The transducer is composed of a magnetostrictive exponential horn and a stainless steel tail mass. In this transducer a spiral magnetic field made up of longitudinal and circumferential magnetic fields is applied to the magnetostrictive horn. As a result, the magnetostrictive horn oscillates simultaneously both longitudinally and torsionally in accordance with the Joule and Wiedemann effects. The magnetostrictive exponential horn is designed in such a manner that it has the same longitudinal and torsional resonant frequency. It is made up of ‘2V Permendur’, which has isotropic magnetic properties. The differential equations of the torsional and longitudinal vibration of the horn are derived, and a HL–TMUT is designed with a resonant frequency of 20 573 Hz. The natural frequency and mode shapes of the transducer are considered theoretically and numerically. The experimental results show that this transducer resonates torsionally and longitudinally with frequencies of 20 610 Hz and 20 830 Hz respectively. The maximum torsional displacement is 1.5 mrad m −1 and the maximum longitudinal displacement is 0.6 μm. These are promising features for industrial applications. (paper)

  8. Design of compact piezoelectric transducers for shock wave applications

    Science.gov (United States)

    Dreyer, Thomas; Liebler, Marko; Riedlinger, Rainer E.; Ginter, Siegfried

    2003-10-01

    The application of focused intense sound pulses to treat several orthopedic diseases has gained in importance during the past years. Self-focusing piezoelectric transducers known from ESWL are not well suited for this purpose due to their size. Therefore compact transducers have to be designed. This implies an increase of the pressure pulse amplitude generated at the radiating surface. A stacked placement of two piezoelectric layers driven by two high-voltage pulses with an adjustable delay accomplishes this. Several designs are presented here representing transducers of different sizes. In principle piezoelectric transducers have the ability to vary the pressure pulse shape to a wider extent than other shock wave sources. Based on FEM simulations of the transducer the influence of some driving parameters, like a variation of the interpulse delay or shape of the driving voltage, on the resulting focal pressure signal is demonstrated. The results show the feasibility to control some parameters of the signal, for example the peak negative pressure amplitude. This possibility could provide new aspects in basic research as well as in clinical applications.

  9. Design of HIFU Transducers for Generating Specified Nonlinear Ultrasound Fields.

    Science.gov (United States)

    Rosnitskiy, Pavel B; Yuldashev, Petr V; Sapozhnikov, Oleg A; Maxwell, Adam D; Kreider, Wayne; Bailey, Michael R; Khokhlova, Vera A

    2017-02-01

    Various clinical applications of high-intensity focused ultrasound have different requirements for the pressure levels and degree of nonlinear waveform distortion at the focus. The goal of this paper is to determine transducer design parameters that produce either a specified shock amplitude in the focal waveform or specified peak pressures while still maintaining quasi-linear conditions at the focus. Multiparametric nonlinear modeling based on the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation with an equivalent source boundary condition was employed. Peak pressures, shock amplitudes at the focus, and corresponding source outputs were determined for different transducer geometries and levels of nonlinear distortion. The results are presented in terms of the parameters of an equivalent single-element spherically shaped transducer. The accuracy of the method and its applicability to cases of strongly focused transducers were validated by comparing the KZK modeling data with measurements and nonlinear full diffraction simulations for a single-element source and arrays with 7 and 256 elements. The results provide look-up data for evaluating nonlinear distortions at the focus of existing therapeutic systems as well as for guiding the design of new transducers that generate specified nonlinear fields.

  10. Robotic radiotherapy for prostate cancer with CyberKnife

    International Nuclear Information System (INIS)

    Hannoun-Levi, J.M.; Benezery, K.; Bondiau, P.Y.; Marcie, S.; Gerard, J.P.; Chamorey, E.

    2007-01-01

    After 3D conformal radiation therapy without and with modulated intensity, image-guided radiation therapy represents a new technological step. Should prostate cancer treatment using radiotherapy with the CyberKnife robotic system be considered as a new treatment and then investigated through classical clinical research procedure rather than a technical improvement of an already validated treatment? After a general presentation of the CyberKnife, the authors focused on prostate cancer treatment assuming that, according to dosimetric and biological considerations, the treatment by robotic system appears comparable to high dose rate brachytherapy. For prostate cancer treatment are discussed: biological rational for hypo fractionated treatment, high dose rate brachytherapy boost and interest of dose escalation. A comparison is presented between CyberKnife and other validated treatment for prostate cancer (radical prostatectomy, 3D conformal radiation therapy and low and high dose rate brachytherapy). In summary, CyberKnife treatment could be considered as a technical improvement of an already validated treatment in order to deliver a prostate boost after pelvic or peri-prostatic area irradiation. However, the clinical, biological and economical results must be precisely analyzed and could be assessed in the frame of a National Observatory based on shared therapeutic program. (authors)

  11. Effect of testicular irradiation on established BPH in the dog: evidence of a non-steroidal testicular factor for BPH maintenance

    International Nuclear Information System (INIS)

    Grayhack, J.T.; Lee, C.; Brand, W.

    1985-01-01

    Irradiation of the testes of four to 13-year-old male beagles with benign prostatic hyperplasia (BPH) was undertaken to attempt to evaluate the possibility that the testes secrete a non-androgenic accessory sex gland-stimulating substance that may have a critical role in the development of BPH. Thirteen non-irradiated and shoulder irradiated control and 16 beagles subjected to 1500 to 2200 rads single dose testis irradiation had pre-irradiation, interval post-irradiation and terminal caliper measurements of prostatic length, width and depth, prostatic and testicular biopsies, and determination of serum testosterone and estradiol levels. Four beagles survived in a group observed for 109 weeks post testis irradiation, 12 in a group observed for 51 and 10 in a group observed for 59 weeks. The wet weight of the prostate was determined at sacrifice. Ratios of the final/initial length and width and final actual/initial calculated weight of the prostate were significantly decreased in testis-irradiated as compared to control beagles. Histologic evaluation also demonstrated a significant difference in degree of prostatic stimulation in control and testis-irradiated groups. The serum testosterone and estradiol levels were not significantly different in the testis-irradiated and control beagles

  12. On complex preparation for radiotherapy of prostatic tumor patients

    International Nuclear Information System (INIS)

    Tkachev, S.I.

    1980-01-01

    An experience with the treatment of 62 patients with prostatic gland tumor has contributed to the elaboration of some approaches to the utilization of modern diagnostic facilities in order to define the spread of neoplastic process and select therapeutic tactics. A sequence of methods to be used has been described, including clinical and X-ray, radioisotope and ultrasonic methods of examination. The matter of particular attention is a newly developed method of the prostatic gland cranio-caudal size determination. The latter together with ultrasonic data enable one to detect the size of the tumor and select an adequate physico-technical regime of irradiation for each individual patient

  13. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO; Avaliacao do efeito radiomodificador da propolis em celulas de ovario de hamster chines (CHO-K1) e em celulas tumorais de prostata (PC3), irradiadas com CO-60

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Geyza Spigoti

    2011-07-01

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with {sup 60}Co {gamma} radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 {mu}g/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400{mu}/ml) in PC3 cells irradiated with 5 G{gamma}. The survival curves obtained were adequately fitted by a linear-quadratic model, where the {alpha} coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 {mu}g/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data

  14. Prostate Cancer—Health Professional Version

    Science.gov (United States)

    Prostate cancers are often adenocarcinomas. Prostatic intraepithelial neoplasia is often present in association with prostatic adenocarcinoma. Find evidence-based information on prostate cancer including treatment, causes and prevention, screening, research, genetics, and statistics.

  15. Ultrasonographic findings in patients with nonbacterial prostatitis

    NARCIS (Netherlands)

    de la Rosette, J. J.; Karthaus, H. F.; Debruyne, F. M.

    1992-01-01

    The potential value of prostatic imaging in the diagnosis of inflammatory disorders of the prostate is largely unexplored. In several studies, specific ultrasonographic characteristics in patients with prostatitis have been described. Also nonspecific echogenic qualities in prostatitis have been

  16. Food irradiation

    International Nuclear Information System (INIS)

    Macklin, M.

    1987-01-01

    The Queensland Government has given its support the establishment of a food irradiation plant in Queensland. The decision to press ahead with a food irradiation plant is astonishing given that there are two independent inquiries being carried out into food irradiation - a Parliamentary Committee inquiry and an inquiry by the Australian Consumers Association, both of which have still to table their Reports. It is fair to assume from the Queensland Government's response to date, therefore, that the Government will proceed with its food irradiation proposals regardless of the outcomes of the various federal inquiries. The reasons for the Australian Democrats' opposition to food irradiation which are also those of concerned citizens are outlined

  17. Food irradiation

    International Nuclear Information System (INIS)

    Duchacek, V.

    1989-01-01

    The ranges of doses used for food irradiation and their effect on the processed foods are outlined. The wholesomeness of irradiated foods is discussed. The present food irradiation technology development in the world is described. A review of the irradiated foods permitted for public consumption, the purposes of food irradiaton, the doses used and a review of the commercial-scale food irradiators are tabulated. The history and the present state of food processing in Czechoslovakia are described. (author). 1 fig., 3 tabs., 13 refs

  18. Irradiated foods

    International Nuclear Information System (INIS)

    Darrington, Hugh

    1988-06-01

    This special edition of 'Food Manufacture' presents papers on the following aspects of the use of irradiation in the food industry:- 1) an outline view of current technology and its potential. 2) Safety and wholesomeness of irradiated and non-irradiated foods. 3) A review of the known effects of irradiation on packaging. 4) The problems of regulating the use of irradiation and consumer protection against abuse. 5) The detection problem - current procedures. 6) Description of the Gammaster BV plant in Holland. 7) World outline review. 8) Current and future commercial activities in Europe. (U.K.)

  19. Urethral dose and increment of international prostate symptom score (IPSS) in transperineal permanent interstitial implant (TPI) of prostate cancer

    International Nuclear Information System (INIS)

    Murakami, N.; Itami, J.; Okuma, K.; Marino, H.; Ban, T.; Nakazato, M.; Kanai, K.; Naoi, K.; Fuse, M.; Nakagawa, K.

    2008-01-01

    Purpose: to find the factors which influence the acute increment of international prostate symptom score (IPSS) after transperineal permanent interstitial implant (TPI) using 125 I seeds. Patients and methods: from April 2004 through September 2006, 104 patients with nonmetastatic prostate cancer underwent TPI without external-beam irradiation. Median patient age was 70 years with a median follow-up of 13.0 months. 73 patients (70%) received neoadjuvant hormone therapy. The increment of IPSS was defined as the difference between pre- and postimplant maximal IPSS. Clinical, treatment, and dosimetric parameters evaluated included age, initial prostate-specific antigen, Gleason Score, neoadjuvant hormone therapy, initial IPSS, post-TPI prostatic volume, number of implanted seeds, prostate V 100 , V 150 , D 90 , urethral D max , and urethral D 90 . In order to further evaluate detailed urethral doses, the base and apical urethra were defined and the dosimetric parameters were calculated. Results: the IPSS peaked 3 months after TPI and returned to baseline at 12-15 months. Multivariate analysis demonstrated a statistically significant correlation of post-TPI prostatic volume, number of implanted seeds, and the dosimetric parameters of the base urethra with IPSS increment. Conclusion: the base urethra appears to be susceptible to radiation and the increased dose to this region deteriorates IPSS. It remains unclear whether the base urethral dose relates to the incidence of late urinary morbidities. (orig.)

  20. Electromechanical characteristics of discal piezoelectric transducers with spiral interdigitated electrodes

    International Nuclear Information System (INIS)

    Pan, Chengliang; Xiao, Guangjun; Feng, Zhihua; Liao, Wei-Hsin

    2014-01-01

    In this study, piezoceramic thin disks with spiral interdigitated electrodes on their surfaces are proposed to generate in-plane torsional vibrations. Electromechanical characteristics of the discal piezoelectric transducers are investigated. Working principles of the transducers are explained while their static deformations are formulated. Dynamic models are derived to analyze the in-plane torsional vibrations of the disks together with the radial vibrations. The corresponding electromechanical equivalent circuits are also obtained. With different boundary conditions and structural parameters, frequency responses of their electric admittances are calculated numerically. Resonant frequencies, mode shapes, and electromechanical coupling coefficients of the vibration modes are also extracted. Prototype transducers are fabricated and tested to validate the theoretical results. (paper)

  1. Inspection of complex geometry pieces with an intelligent contact transducer

    International Nuclear Information System (INIS)

    Chatillon, S.; Roy, O.; Mahaut, St.

    2000-01-01

    A new multi-element contact transducer has been developed to improve the inspection of components with complex geometry. The emitting surface is flexible in order to optimize the contact with pieces. An algorithm, based on a simplified geometric model, has been used to determine the delays law which allows to control the focal characteristics of the transmitted field. Acquisition data lead in transmission with an articulated transducer validate the behavior provided by simulation. Thus the optimization of the delays law ensures the transmission of a beam which is homogeneous and controlled during the moving of the transducer. Inspections in echo-pulse mode are implemented on a sample simulating a component controlled on site. Results show that the dynamical adaptation of the delays law to the geometry of the piece leads to very good performances

  2. Actuators, transducers and motors based on giant magnetostrictive materials

    Energy Technology Data Exchange (ETDEWEB)

    Claeyssen, F.; Lhermet, N.; Le Letty, R. [Cedrat Recherche, Meylan (France); Bouchilloux, P. [Magsoft Corporation, 1223 People`s Avenue, New York 12180 (United States)

    1997-08-01

    Rare earth-iron magnetostrictive alloys, especially Terfenol-D, feature ``giant`` magnetostrains: static strains of 1000-2000 ppm and dynamic strains of 3500 ppm are reported. These strains permit building various actuating devices (actuators, transducers, motors) both at macro and micro scale. The object of the paper is to recall adapted design methods, especially finite element methods such as ATILA, and to review these different kinds of devices studied at Cedrat Recherche, providing both up-dated experimental and numerical results. The presented devices will include several large displacement longitudinal and shear actuators biased using permanent magnets and used either as characterisation devices or as electromechanical actuators (for active damping, for sonar transducers..), a 1 kHz 4 kW Tonpilz-type sonar transducer called the tripode, a 2 N m torque rotating multi-mode motor, a torsion based drift free micro actuator and a wireless linear micromotor. (orig.)

  3. Torque magnetometry by use of capacitance type transducer

    International Nuclear Information System (INIS)

    Braught, M.C.; Pechan, M.J.

    1992-01-01

    Interfacial anisotropy in magnetic multilayered samples comprised of nanometer thick magnetic layers alternating with non-magnetic layers is investigated by torque magnetometry in the temperature regime of 4 to 300K. The design, construction and use of a capacitance type transducer wherein the sample is mounted directly on with the plate of the capacitor, will be described. As a result the sample and transducer spatially coexist at the sample temperature in an applied external field, eliminating mechanical coupling from the cryogenic region to a remote room temperature transducer. The capacitor measuring the torque of the sample is paired with a reference capacitor. The difference between torque influenced capacitance and the reference is then determined by a differential transimpedance amplifier. Since both capacitors are physically identical variables such as temperature, vibration, orientation and external devices are minimized. Torques up to 300 dyne-cm can be measured with a sensitivity of 0.010 dyne-cm

  4. A novel serrated columnar phased array ultrasonic transducer

    Science.gov (United States)

    Zou, Cheng; Sun, Zhenguo; Cai, Dong; Song, Hongwei; Chen, Qiang

    2016-02-01

    Traditionally, wedges are required to generate transverse waves in a solid specimen and mechanical rotation device is needed for interrogation of a specimen with a hollow bore, such as high speed railway locomotive axles, turbine rotors, etc. In order to eliminate the mechanical rotation process, a novel array pattern of phased array ultrasonic transducers named as serrated columnar phased array ultrasonic transducer (SCPAUT) is designed. The elementary transducers are planar rectangular, located on the outside surface of a cylinder. This layout is aimed to generate electrically rotating transverse waveforms so as to inspect the longitudinal cracks on the outside surface of a specimen which has a hollow bore at the center, such as the high speed railway locomotive axles. The general geometry of the SCPAUT and the inspection system are illustrated. A FEM model and mockup experiment has been carried out. The experiment results are in good agreement with the FEM simulation results.

  5. INFLUENCE OF PIEZOELECTRIC TRANSDUCER TO GLASS FIBER REINFORCED COMPOSITE STIFFNESS

    Directory of Open Access Journals (Sweden)

    Witold Rządkowski

    2015-08-01

    Full Text Available The main goal was to determine if transducers based on piezoelectric materials are suitable for strain calculations in thin GFRP specimens. Numerous experimental studies, both physical and numerical, performed by the authors, have shown that there is a huge influence of bonded piezoelectric transducer on the overall stiffness of the measured object. The paper presents tensile test performed on strength machine with Digital Image Correlation strain and deflection observations. Test were compared with FEM models for detailed investigation. The main conclusion is piezoelectric transducers has huge influence on local stiffness of measured object. That is critical especially when they are used as strain sensors, when presence of sensor is influencing to measured results.

  6. Investigation of Calibrating Force Transducer Using Sinusoidal Force

    International Nuclear Information System (INIS)

    Zhang Li; Wang Yu; Zhang Lizhe

    2010-01-01

    Sinusoidal force calibration method was studied several years before at Physikalisch-Technische Bundesanstalt (PTB). A similar dynamic force calibration system is developed at Changcheng Institute of Metrology and Measurement (CIMM). It uses electro-dynamic shakers to generate dynamic force in the range from 1 N to 20 kN, and heterodyne laser interferometers are used for acceleration measurement. The force transducer to be calibrated is mounted on the shaker, and a mass block is screwed on the top of force transducer, the sinusoidal forces realized by accelerated load masses are traceable to acceleration and mass according to the force definition. The methods of determining Spatial-dependent acceleration on mass block and measuring the end mass of force transducer in dynamic force calibration are discussed in this paper.

  7. Measurement of two-phase flow momentum with force transducers

    International Nuclear Information System (INIS)

    Hardy, J.E.; Smith, J.E.

    1990-01-01

    Two strain-gage-based drag transducers were developed to measure two-phase flow in simulated pressurized water reactor (PWR) test facilities. One transducer, a drag body (DB), was designed to measure the bidirectional average momentum flux passing through an end box. The second drag sensor, a break through detector (BTD), was designed to sense liquid downflow from the upper plenum to the core region. After prototype sensors passed numerous acceptance tests, transducers were fabricated and installed in two experimental test facilities, one in Japan and one in West Germany. High-quality data were extracted from both the DBs and BTDs for a variety of loss-of-coolant accident (LOCA) scenarios. The information collected from these sensors has added to the understanding of the thermohydraulic phenomena that occur during the refill/reflood stage of a LOCA in a PWR. 9 refs., 15 figs

  8. A new ultrasonic transducer for improved contrast nonlinear imaging

    International Nuclear Information System (INIS)

    Bouakaz, Ayache; Cate, Folkert ten; Jong, Nico de

    2004-01-01

    Second harmonic imaging has provided significant improvement in contrast detection over fundamental imaging. This improvement is a result of a higher contrast-to-tissue ratio (CTR) achievable at the second harmonic frequency. Nevertheless, the differentiation between contrast and tissue at the second harmonic frequency is still in many situations cumbersome and contrast detection remains nowadays as one of the main challenges, especially in the capillaries. The reduced CTR is mainly caused by the generation of second harmonic energy from nonlinear propagation effects in tissue, which hence obscures the echoes from contrast bubbles. In a previous study, we demonstrated theoretically that the CTR increases with the harmonic number. Therefore the purpose of our study was to increase the CTR by selectively looking to the higher harmonic frequencies. In order to be able to receive these high frequency components (third up to the fifth harmonic), a new ultrasonic phased array transducer has been constructed. The main advantage of the new design is its wide frequency bandwidth. The new array transducer contains two different types of elements arranged in an interleaved pattern (odd and even elements). This design enables separate transmission and reception modes. The odd elements operate at 2.8 MHz and 80% bandwidth, whereas the even elements have a centre frequency of 900 kHz with a bandwidth of 50%. The probe is connected to a Vivid 5 system (GE-Vingmed) and proper software is developed for driving. The total bandwidth of such a transducer is estimated to be more than 150% which enables higher harmonic imaging at an adequate sensitivity and signal to noise ratio compared to standard medical array transducers. We describe in this paper the design and fabrication of the array transducer. Moreover its acoustic properties are measured and its performances for nonlinear contrast imaging are evaluated in vitro and in vivo. The preliminary results demonstrate the advantages of

  9. Transducers for the Brazilian gravitational wave detector 'Mario Schenberg'

    International Nuclear Information System (INIS)

    Frajuca, Carlos; Ribeiro, Kilder L; Andrade, Luiz A; Jr, Walter F Velloso; Melo, Jose L; Aguiar, Odylio D; Magalhaes, Nadja S

    2002-01-01

    'Mario Schenberg' is a spherical resonant-mass gravitational wave (GW) detector that will be part of a GW detection array of three detectors. The other two will be built in Italy and the Netherlands. Their resonant frequencies will be around 3.2 kHz with a bandwidth of about 200 Hz. This range of frequencies is new in a field where the typical frequencies lie below 1 kHz, making the transducer development much more complex. In this paper, the design of the mechanical part of the transducer will be shown, as well as the attachment method to the sphere and the expected sensitivity

  10. A digital transducer and digital microphone using an optical technique

    Science.gov (United States)

    Ghelmansarai, F. A.

    1996-09-01

    A transducer is devised to measure pressure, displacements or angles by optical means. This transducer delivers a digital output without relying on interferometry techniques or analogue-to-digital converters. This device is based on an optical scanner and an optical detector. An inter-digital photoconductive detector (IDPC) is employed that delivers a series of pulses, whose number depends on the scan length. A pre-objective scanning configuration is used that allows for the possibility of a flat image plane. The optical scanner provides scanning of IDPC and the generated scan length is proportional to the measurand.

  11. An overview of the dynamic calibration of piezoelectric pressure transducers

    Science.gov (United States)

    Theodoro, F. R. F.; Reis, M. L. C. C.; d’ Souto, C.

    2018-03-01

    Dynamic calibration is a research area that is still under development and is of great interest to aerospace and automotive industries. This study discusses some concepts regarding dynamic measurements of pressure quantities and presents an overview of dynamic calibration of pressure transducers. Studies conducted by the Institute of Aeronautics and Space focusing on research regarding piezoelectric pressure transducer calibration in shock tube are presented. We employed the Guide to the Expression of Uncertainty and a Monte Carlo Method in the methodology. The results show that both device and methodology employed are adequate to calibrate the piezoelectric sensor.

  12. Thermal energy harvesters with piezoelectric or electrostatic transducer

    Science.gov (United States)

    Prokaryn, Piotr; Domański, Krzysztof; Marchewka, Michał; Tomaszewski, Daniel; Grabiec, Piotr; Puscasu, Onoriu; Monfray, Stéphane; Skotnicki, Thomas

    2014-08-01

    This paper describes the idea of the energy harvester which converts thermal gradient present in environment into electricity. Two kinds of such devices are proposed and their prototypes are shown and discussed. The main parts of harvesters are bimetallic spring, piezoelectric transducer or electrostatic transducer with electret. The applied piezomembrane was commercial available product but electrets was made by authors. In the paper a fabrication procedure of electrets formed by the corona discharge process is described. Devices were compared in terms of generated power, charging current, and the voltage across a storage capacitor.

  13. Fungal prostatitis: an update.

    Science.gov (United States)

    Mayayo, Emilio; Fernández-Silva, Fabiola

    2014-06-01

    Prostate pathology is a daily occurrence in urological and general medical consultations. Besides hyperplasia and neoplastic pathology, other processes, such as infectious ones, are also documented. Their etiology is diverse and varied. Within the infectious prostatic processes, fungi can also be a specific cause of prostatitis. Fungal prostatitis often appears in patients with impaired immunity and can also be rarely found in healthy patients. It can result from a disseminated infection, but it can also be localized. Fungal prostatitis is a nonspecific and harmless process. Diagnosis is commonly made by fine needle aspiration cytology or by biopsy. A number of fungi can be involved. Although there are not many reported cases, they are becoming more frequent, in particular in patients with some degree of immunodeficiency or those who live in areas where specific fungi are endemic or in visitors of those areas. We present a comprehensive review of the various forms of fungal prostatitis, and we describe the morphological characteristics of the fungi more frequently reported as causes of fungal prostatitis. We also report our own experience, aiming to alert physicians, urologists and pathologists of these particular infections.

  14. Radioimmunoassay for a human prostate specific antigen

    International Nuclear Information System (INIS)

    Machida, T.; Miki, M.; Ohishi, Y.; Kido, A.; Morikawa, J.; Ogawa, Y.

    1983-01-01

    As a marker for prostatic cancer, a prostate-specific antigen was purified from human prostatic tissues. Double antibody radioimmunoassay utilizing immune reaction was developed on the basis of the purified prostatic antigen (PA). Measurement results have revealed that PA radioimmunoassay is much better than prostatic acid phosphatase (PAP) radioimmunoassay in the diagnosis of prostatic cancer

  15. Prostate Cancer Ambassadors

    Science.gov (United States)

    Vines, Anissa I.; Hunter, Jaimie C.; Carlisle, Veronica A.; Richmond, Alan N.

    2016-01-01

    African American men bear a higher burden of prostate cancer than Caucasian men, but knowledge about how to make an informed decision about prostate cancer screening is limited. A lay health advisor model was used to train “Prostate Cancer Ambassadors” on prostate cancer risk and symptoms, how to make an informed decision for prostate-specific antigen screening, and how to deliver the information to members of their community. Training consisted of two, 6-hour interactive sessions and was implemented in three predominantly African American communities over an 8-month period between 2013 and 2014. Following training, Ambassadors committed to contacting at least 10 people within 3 months using a toolkit composed of wallet-sized informational cards for distribution, a slide presentation, and a flip chart. Thirty-two Ambassadors were trained, with more than half being females (59%) and half reporting a family history of prostate cancer. Prostate cancer knowledge improved significantly among Ambassadors (p ≤ .0001). Self-efficacy improved significantly for performing outreach tasks (p < .0001), and among women in helping a loved one with making an informed decision (p = .005). There was also an improvement in collective efficacy in team members (p = .0003). Twenty-nine of the Ambassadors fulfilled their commitment to reach at least 10 people (average number of contacts per Ambassador was 11). In total, 355 individuals were reached with the prostate cancer information. The Ambassador training program proved successful in training Ambassadors to reach communities about prostate cancer and how to make an informed decision about screening. PMID:27099348

  16. Prognostic role of serum prostatic acid phosphatase for 103Pd-based radiation for prostatic carcinoma

    International Nuclear Information System (INIS)

    Dattoli, Michael; Wallner, Kent; True, Lawrence; Sorace, Richard; Koval, John; Cash, Jennifer; Acosta, Rudolph; Biswas, Mohendra; Binder, Michael; Sullivan, Brent; Lastarria, Emilio; Kirwan, Novelle; Stein, Douglas

    1999-01-01

    Purpose: To establish the prognostic role of serum enzymatic prostatic acid phosphatase (PAP) in patients treated with palladium ( 103 Pd) and supplemental external beam irradiation (EBRT) for clinically localized, high-risk prostate carcinoma. Methods and Materials: One hundred twenty-four consecutive patients with Stage T2a-T3 prostatic carcinoma were treated from 1992 through 1995. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (100 patients), Gleason score 7-10 (40 patients), pretreatment prostate specific antigen (PSA) > 15 ng/ml (32 patients), or elevated serum PAP (25 patients). Patients received 41 Gy conformal EBRT to a limited pelvic field, followed 4 weeks later by a 103 Pd boost (prescription dose 80 Gy). Biochemical failure was defined as a PSA greater than 1 ng/ml (normal < 4 ng/ml). Results: The overall, actuarial freedom from biochemical failure at 4 years after treatment was 79%. In Cox-proportional hazard multivariate analysis, the strongest predictor of failure was elevated pretreatment acid phosphatase (p = 0.02), followed by Gleason score (p = 0.1), and PSA (p = 0.14). Conclusion: PAP was the strongest predictor of long-term biochemical failure. It may be a more accurate indicator of micrometastatic disease than PSA, and as such, we suggest that it be reconsidered for general use in radiation-treated patients

  17. The role of IL-6 in the radiation response of prostate cancer

    International Nuclear Information System (INIS)

    Wu, Chun-Te; Chen, Miao-Fen; Chen, Wen-Cheng; Hsieh, Ching-Chuan

    2013-01-01

    Hormone-resistant (HR) prostate cancers are highly aggressive and respond poorly to treatment. IL-6/STAT3 signaling has been identified to link with the transition of HR and aggressive tumor behavior. The role of IL-6 in the radiation response of prostate cancer was investigated in the present study. The murine prostate cancer cell line (TRAMP-C1) and the hormone-resistant cell sub-line, TRAMP-HR, were used to assess the radiation response using in vitro clonogenic assays and tumor growth delay in vivo. Biological changes following irradiation were investigated by means of experimental manipulation of IL-6 signaling. Correlations among IL-6 levels, tumor regrowth, angiogenesis and myeloid-derived suppressor cell (MDSC) recruitment were examined in an animal model. HR prostate cancer cells had a higher expression of IL-6 and more activated STAT3, compared to TRAMP-C1 cells. HR prostate cancer cells had a greater capacity to scavenge reactive oxygen species, suffered less apoptosis, and subsequently were more likely to survive after irradiation. Moreover, IL-6 expression was positively linked to irradiation and radiation resistance. IL-6 inhibition enhanced the radiation sensitivity of prostate cancer, which was associated with increased p53, RT-induced ROS and oxidative DNA damage. Furthermore, when mice were irradiated with a sub-lethal dose, inhibition of IL-6 protein expression attenuated angiogenesis, MDSC recruitment, and decreased tumor regrowth. These data demonstrate that IL-6 is important in the biological sequelae following irradiation. Therefore, treatment with concurrent IL-6 inhibition is a potential therapeutic strategy for increasing the radiation response of prostate cancer

  18. Ultrasonically guided 125iodine seed implantation with external radiation in management of localized prostatic carcinoma

    DEFF Research Database (Denmark)

    Iversen, P; Bak, M; Juul, N

    1989-01-01

    Thirty-three patients with localized prostatic carcinoma (16 poorly differentiated) were treated with transperineal 125Iodine seed implantation (160 Gy) guided by transrectal ultrasonography and subsequent external beam irradiation (47.4 Gy). The observation time was six to sixty-eight months...... with a median follow-up of thirty-five months. Median change in prostatic volume was a reduction of 35 percent. Re-biopsy or transurethral resection of the prostate was performed in 25 patients after one to two years, revealing still malignant histology in 12 (48%). Development of distant metastases occurred...

  19. An evaluation of intrafraction motion of the prostate in the prone and supine positions using electromagnetic tracking

    International Nuclear Information System (INIS)

    Shah, Amish P.; Kupelian, Patrick A.; Willoughby, Twyla R.; Langen, Katja M.; Meeks, Sanford L.

    2011-01-01

    Purpose: To evaluate differences in target motion during prostate irradiation in the prone versus supine position using electromagnetic tracking to measure prostate mobility. Materials/methods: Twenty patients received prostate radiotherapy in the supine position utilizing the Calypso Localization System (registered) for prostate positioning and monitoring. For each patient, 10 treatment fractions were followed by a session in which the patient was repositioned prone, and prostate mobility was tracked. The fraction of time that the prostate was displaced by >3, 5, 7, and 10 mm was calculated for each patient, for both positions (400 tracking sessions). Results: Clear patterns of respiratory motion were seen in the prone tracks due to the influence of increased abdominal motion. Averaged over all patients, the prostate was displaced >3 and 5 mm for 37.8% and 10.1% of the total tracking time in the prone position, respectively. In the supine position, the prostate was displaced >3 and 5 mm for 12.6% and 2.9%, respectively. With both patient setups, inferior and posterior drifts of the prostate position were observed. Averaged over all prone tracking sessions, the prostate was displaced >3 mm in the posterior and inferior directions for 11.7% and 9.5% of the total time, respectively. Conclusions: With real-time tracking of the prostate, it is possible to study the effects of different setup positions on the prostate mobility. The percentage of time the prostate moved >3 and 5 mm was increased by a factor of three in the prone versus supine position. For larger displacements (>7 mm) no difference in prostate mobility was observed between prone and supine positions. To reduce rectal toxicity, radiotherapy in the prone position may be a suitable alternative provided respiratory motion is accounted for during treatment. Acute and late toxicity results remain to be evaluated for both patient positions.

  20. Foodstuff irradiation

    International Nuclear Information System (INIS)

    1982-01-01

    Report written on behalf of the Danish Food Institute summarizes national and international rules and developments within food irradiation technology, chemical changes in irradiated foodstuffs, microbiological and health-related aspects of irradiation and finally technological prospects of this conservation form. Food irradiatin has not been hitherto applied in Denmark. Radiation sources and secondary radiation doses in processed food are characterized. Chemical changes due to irradiation are compared to those due to p.ex. food heating. Toxicological and microbiological tests and their results give no unequivocal answer to the problem whether a foodstuff has been irradiated. The most likely application fields in Denmark are for low radiation dosis inhibition of germination, riping delay and insecticide. Medium dosis (1-10 kGy) can reduce bacteria number while high dosis (10-50 kGy) will enable total elimination of microorganisms and viruses. Food irradiation can be acceptable as technological possibility with reservation, that further studies follow. (EG)

  1. Synergistic interaction of benign prostatic hyperplasia and prostatitis on prostate cancer risk

    Science.gov (United States)

    Hung, S-C; Lai, S-W; Tsai, P-Y; Chen, P-C; Wu, H-C; Lin, W-H; Sung, F-C

    2013-01-01

    Background: The incidence of prostate cancer is much lower in Asian men than in Western men. This study investigated whether prostate cancer is associated with prostatitis, benign prostatic hyperplasia (BPH), and other medical conditions in the low-incidence population. Methods: From the claims data obtained from the universal National Health Insurance of Taiwan, we identified 1184 patients with prostate cancer diagnosed from 1997 to 2008. Controls comprised 4736 men randomly selected from a cancer-free population. Both groups were 50 years of age or above. Medical histories between the two groups were compared. Results: Multivariate logistic regression analysis showed that prostatitis and BPH had stronger association with prostate cancer than the other medical conditions tested. Compared with men without prostatitis and BPH, a higher odds ratio (OR) for prostate cancer was associated with BPH (26.2, 95% confidence interval (CI) 20.8–33.0) than with prostatitis (10.5, 95% CI=3.36–32.7). Men with both conditions had an OR of 49.2 (95% CI=34.7–69.9). Conclusion: Men with prostate cancer have strong association with prostatitis and/or BPH. Prostatitis interacts with BPH, resulting in higher estimated relative risk of prostate cancer in men suffering from both conditions. PMID:23612451

  2. Analysis of eigenfrequencies in piezoelectric transducers using the finite element method

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1988-01-01

    transducers, which include the complete set of piezoelectric equations, have been included. They can find eigenfrequencies for undamped transducers and perform forced-response analysis for transducers with internal and radiation damping. The superelement technique is used to model the transducer backing......It is noted that the finite-element method is a valuable supplement to the traditional methods for design of novel transducer types because it can determine the vibrational pattern of piezoelectric transducers and is applicable to any geometry. Computer programs for analysis of axisymmetric...

  3. Determination of the response time of pressure transducers using the direct method

    International Nuclear Information System (INIS)

    Perillo, S.R.P.

    1994-01-01

    The available methods to determine the response time of nuclear safety related pressure transducers are discussed, with emphasis to the direct method. In order to perform the experiments, a Hydraulic Ramp Generator was built. The equipment produces ramp pressure transients simultaneously to a reference transducer and to the transducer under test. The time lag between the output of the two transducers, when they reach a predetermined setpoint, is measured as the time delay of the transducer under test. Some results using the direct method to determine the time delay of pressure transducers (1 E Class Conventional) are presented. (author). 18 refs, 35 figs, 12 tabs

  4. Interstitially implanted I125 for prostate cancer using transrectal ultrasound

    International Nuclear Information System (INIS)

    Greenburg, S.; Petersen, J.; Hansen-Peters, I.; Baylinson, W.

    1990-01-01

    Prostate cancer is the third leading cause of death from cancer among men in the United States. Traditional treatments for prostate cancer are prostatectomy, external beam irradiation, and interstitial implantation of Iodine125 (I125) via laparotomy. These treatments are associated with significant morbidity and limitations. Based on experience with I125 interstitial implantation by transrectal ultrasound guidance for early-stage prostate cancer, it seems that this newer method of treatment has greater accuracy of placement and distribution of the isotope and has had few reported complications. The need for a surgical incision has been eliminated. Hospitalization time also has been decreased, creating the need for ambulatory and inpatient nurses to understand the importance of their respective roles in providing coordinated quality care for these patients. Nurses in these departments must have knowledge of the procedure, radiation safety, and common side effects related to the implant

  5. Wall thickness tests by means of rotating electrodynamic transducers

    International Nuclear Information System (INIS)

    Hueschelrath, G.

    1986-01-01

    For about three years, the EROT system has been employed for measuring wall thicknesses on pipes of ferritic steels. The experience gathered and the degree of reliability reached up to now are definitely encouraging, so that an increased use of electrodynamic transducers can be expected for measuring pipes with outside diameters of up to 22 inches. (orig.) [de

  6. A New High-Temperature Ultrasonic Transducer for Continuous Inspection.

    Science.gov (United States)

    Amini, Mohammad Hossein; Sinclair, Anthony N; Coyle, Thomas W

    2016-03-01

    A novel design of piezoelectric ultrasonic transducer is introduced, suitable for operation at temperatures of up to 700 °C-800 °C. Lithium niobate single crystal is chosen as the piezoelectric element primarily due to the high Curie temperature of 1200 °C. A backing element based on a porous ceramic is designed for which the pore volume fraction and average pore diameter in the ceramic matrix can be controlled in the manufacturing process; this enables the acoustic impedance and attenuation to be selected to match their optimal values as predicted by a one-dimensional transducer model of the entire transducer. Porous zirconia is selected as the ceramic matrix material of the backing element to obtain an ultrasonic signal with center frequency of 2.7-3 MHz, and 3-dB bandwidth of 90%-95% at the targeted operating temperature. Acoustic coupling of the piezocrystal to the backing element and matching layer is investigated using commercially available high-temperature adhesives and brazing alloys. The performance of the transducer as a function of temperature is studied. Stable bonding and clear signals were obtained using an aluminum brazing alloy as the bonding agent.

  7. Universal Quantum Transducers Based on Surface Acoustic Waves

    NARCIS (Netherlands)

    Schuetz, M.J.A.; Kessler, E.M.; Giedke, G.; Vandersypen, L.M.K.; Lukin, M.D.; Cirac, J.I.

    2015-01-01

    We propose a universal, on-chip quantum transducer based on surface acoustic waves in piezoactive materials. Because of the intrinsic piezoelectric (and/or magnetostrictive) properties of the material, our approach provides a universal platform capable of coherently linking a broad array of qubits,

  8. Instantaneous input electrical power measurements of HITU transducer

    Energy Technology Data Exchange (ETDEWEB)

    Karaboece, B; Guelmez, Y [Tuebitak Ulusal Metroloji Enstituesue (UME), P.K. 54 41470 Gebze-Kocaeli (Turkey); Rajagapol, S; Shaw, A, E-mail: baki.karaboce@ume.tubitak.gov.t [National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW (United Kingdom)

    2011-02-01

    HITU (High Intensity Theraupetic Ultrasound) transducers are widely used in therapeutic ultrasound in medicine. The output ultrasonic power of HITU transducer can be measured in number of methods described in IEC 61161 standard [1]. New IEC standards specifically for measurement of HITU equipment are under development. The ultrasound power radiated from a transducer is dependent on applied input electrical voltage and current and consequently power. But, up to now, no standardised method has been developed and adopted for the input electrical power measurements. Hence, a workpackage was carried out for the establishment of such method in the frequency range of 1 to 3 MHz as a part of EURAMET EMRP Era-net plus 'External Beam Cancer Therapy' project. Several current shunts were developed and evaluated. Current measurements were also realized with Philips current probe and preamplifier at NPL and Agilent current probe at UME. In this paper, a method for the measurement of instantaneous electrical power delivered to a reactive ultrasound transducer in the required frequency range is explored.

  9. Nonlinear Dynamic Modeling of Langevin-Type Piezoelectric Transducers

    Directory of Open Access Journals (Sweden)

    Nicolás Peréz Alvarez

    2015-11-01

    Full Text Available Langevin transducers are employed in several applications, such as power ultrasound systems, naval hydrophones, and high-displacement actuators. Nonlinear effects can influence their performance, especially at high vibration amplitude levels. These nonlinear effects produce variations in the resonant frequency, harmonics of the excitation frequency, in addition to loss of symmetry in the frequency response and “frequency domain hysteresis”. In this context, this paper presents a simplified nonlinear dynamic model of power ultrasound transducers requiring only two parameters for simulating the most relevant nonlinear effects. One parameter reproduces the changes in the resonance frequency and the other introduces the dependence of the frequency response on the history of the system. The piezoelectric constitutive equations are extended by a linear dependence of the elastic constant on the mechanical displacement amplitude. For introducing the frequency hysteresis, the elastic constant is computed by combining the current value of the mechanical amplitude with the previous state amplitude. The model developed in this work is applied for predicting the dynamic responses of a 26 kHz ultrasonic transducer. The comparison of theoretical and experimental responses, obtained at several input voltages around the tuned frequency, shows a good agreement, indicating that the model can accurately describe the transducer nonlinear behavior.

  10. Analysis of a non-contact magnetoelastic torque transducer

    International Nuclear Information System (INIS)

    Andreescu, R.; Spellman, B.; Furlani, E.P.

    2008-01-01

    Results are presented for the performance of a magnetoelastic torque transducer that converts a torque-induced strain in a non-magnetic shaft into changes in a measurable magnetic field. The magnetic field is generated by a thin magnetostrictive layer that is coated onto the circumference of the shaft. The layer is magnetized and has an initial residual strain. The magnetization within the layer rotates in response to changes in the strain which occur when the shaft is torqued. The magnetic field produced by the layer changes with the magnetization and this can be sensed by a magnetometer to monitor the torque on the shaft. In this paper, a phenomenological theory is developed for predicting the performance of the transducer. The theory can be used to predict the magnetic field distribution of the transducer as a function of the physical properties of the magnetic coating, its residual strain, and the applied torque. It enables rapid parametric analysis of transducer performance, which is useful for the development and optimization of novel non-contact torque sensors

  11. Power doppler 'blanching' after the application of transducer pressure

    International Nuclear Information System (INIS)

    Joshua, F.; Edmonds, J.; Lassere, M.; De Carle, R.; Rayment, M.; Bryant, C.; Shnier, R.

    2005-01-01

    The aim of this study was to determine if transducer pressure modifies power Doppler assessments of rheumatoid arthritis synovium at the metacarpophalangeal joints and metatarsophalangeal joints. Five rheumatoid arthritis patients of varying degrees of 'disease activity' and damage were assessed with power Doppler ultrasound scanning of the dominant hand second to fifth metacarpophalangeal joints. Two rheumatoid arthritis patients had their dominant foot first to fifth metatarsophalangeal joints assessed with power Doppler ultrasound. Ultrasonography was performed with a high frequency transducer (14 MHz) with a colour mode frequency of 10 Mhz, and a standard colour box and gain. In the joint that showed the highest power Doppler signal, an image was made. A further image was taken after transducer pressure was applied. In all patients, there was increased flow to at least one joint. After pressure was applied, power Doppler signal intensity markedly reduced in all images and in some there was no recordable power Doppler signal. Increased transducer pressure can result in a marked reduction or obliteration in power Doppler signal. This power Doppler 'blanching' shows the need for further studies to evaluate sources of error and standardization before power Doppler ultrasound becomes a routine measure of 'disease activity' in rheumatoid arthritis. Copyright (2005) Blackwell Science Pty Ltd

  12. A capacitive ultrasonic transducer based on parametric resonance.

    Science.gov (United States)

    Surappa, Sushruta; Satir, Sarp; Levent Degertekin, F

    2017-07-24

    A capacitive ultrasonic transducer based on a parametric resonator structure is described and experimentally demonstrated. The transducer structure, which we call capacitive parametric ultrasonic transducer (CPUT), uses a parallel plate capacitor with a movable membrane as part of a degenerate parametric series RLC resonator circuit with a resonance frequency of f o . When the capacitor plate is driven with an incident harmonic ultrasonic wave at the pump frequency of 2f o with sufficient amplitude, the RLC circuit becomes unstable and ultrasonic energy can be efficiently converted to an electrical signal at f o frequency in the RLC circuit. An important characteristic of the CPUT is that unlike other electrostatic transducers, it does not require DC bias or permanent charging to be used as a receiver. We describe the operation of the CPUT using an analytical model and numerical simulations, which shows drive amplitude dependent operation regimes including parametric resonance when a certain threshold is exceeded. We verify these predictions by experiments with a micromachined membrane based capacitor structure in immersion where ultrasonic waves incident at 4.28 MHz parametrically drive a signal with significant amplitude in the 2.14 MHz RLC circuit. With its unique features, the CPUT can be particularly advantageous for applications such as wireless power transfer for biomedical implants and acoustic sensing.

  13. Testing of electron beam welding by ultrasonic transducers

    International Nuclear Information System (INIS)

    Touffait, A.-M.; Roule, M.; Destribats, M.-T.

    1978-01-01

    Focalized ultrasonic testing is well adapted to the study of electron beam welding. This type of welding leads to narrow weld beads and to small dimension testing zones. Focalized transducers can be used enabling very small defects to be detected [fr

  14. Instantaneous input electrical power measurements of HITU transducer

    International Nuclear Information System (INIS)

    Karaboece, B; Guelmez, Y; Rajagapol, S; Shaw, A

    2011-01-01

    HITU (High Intensity Theraupetic Ultrasound) transducers are widely used in therapeutic ultrasound in medicine. The output ultrasonic power of HITU transducer can be measured in number of methods described in IEC 61161 standard [1]. New IEC standards specifically for measurement of HITU equipment are under development. The ultrasound power radiated from a transducer is dependent on applied input electrical voltage and current and consequently power. But, up to now, no standardised method has been developed and adopted for the input electrical power measurements. Hence, a workpackage was carried out for the establishment of such method in the frequency range of 1 to 3 MHz as a part of EURAMET EMRP Era-net plus 'External Beam Cancer Therapy' project. Several current shunts were developed and evaluated. Current measurements were also realized with Philips current probe and preamplifier at NPL and Agilent current probe at UME. In this paper, a method for the measurement of instantaneous electrical power delivered to a reactive ultrasound transducer in the required frequency range is explored.

  15. Candle soot nanoparticles-polydimethylsiloxane composites for laser ultrasound transducers

    Science.gov (United States)

    Chang, Wei-Yi; Huang, Wenbin; Kim, Jinwook; Li, Sibo; Jiang, Xiaoning

    2015-10-01

    Generation of high power laser ultrasound strongly demands the advanced materials with efficient laser energy absorption, fast thermal diffusion, and large thermoelastic expansion capabilities. In this study, candle soot nanoparticles-polydimethylsiloxane (CSNPs-PDMS) composite was investigated as the functional layer for an optoacoustic transducer with high-energy conversion efficiency. The mean diameter of the collected candle soot carbon nanoparticles is about 45 nm, and the light absorption ratio at 532 nm wavelength is up to 96.24%. The prototyped CSNPs-PDMS nano-composite laser ultrasound transducer was characterized and compared with transducers using Cr-PDMS, carbon black (CB)-PDMS, and carbon nano-fiber (CNFs)-PDMS composites, respectively. Energy conversion coefficient and -6 dB frequency bandwidth of the CSNPs-PDMS composite laser ultrasound transducer were measured to be 4.41 × 10-3 and 21 MHz, respectively. The unprecedented laser ultrasound transduction performance using CSNPs-PDMS nano-composites is promising for a broad range of ultrasound therapy applications.

  16. Enhancing endosomal escape of transduced proteins by photochemical internalisation.

    Directory of Open Access Journals (Sweden)

    Kevin Mellert

    Full Text Available Induced internalisation of functional proteins into cultured cells has become an important aspect in a rising number of in vitro and in vivo assays. The endo-lysosomal entrapment of the transduced proteins remains the major problem in all transduction protocols. In this study we compared the efficiency, cytotoxicity and protein targeting of different commercially available transduction reagents by transducing a well-studied fluorescently labelled protein (Atto488-bovine serum albumin into cultured human sarcoma cells. The amount of internalised protein and toxicity differed between the different reagents, but the percentage of transduced cells was consistently high. Furthermore, in all protocols the signals of the transduced Atto488-BSA were predominantly punctual consistent with an endosomal localisation. To overcome the endosomal entrapment, the transduction protocols were combined with a photochemical internalisation (PCI treatment. Using this combination revealed that an endosomal disruption is highly effective in cell penetrating peptide (CPP mediated transduction, whereas lipid-mediated transductions lead to a lower signal spreading throughout the cytosol. No change in the signal distribution could be achieved in treatments using non-lipid polymers as a transduction reagent. Therefore, the combination of protein transduction protocols based on CPPs with the endosomolytic treatment PCI can facilitate protein transduction experiments in vitro.

  17. Enhancing endosomal escape of transduced proteins by photochemical internalisation.

    Science.gov (United States)

    Mellert, Kevin; Lamla, Markus; Scheffzek, Klaus; Wittig, Rainer; Kaufmann, Dieter

    2012-01-01

    Induced internalisation of functional proteins into cultured cells has become an important aspect in a rising number of in vitro and in vivo assays. The endo-lysosomal entrapment of the transduced proteins remains the major problem in all transduction protocols. In this study we compared the efficiency, cytotoxicity and protein targeting of different commercially available transduction reagents by transducing a well-studied fluorescently labelled protein (Atto488-bovine serum albumin) into cultured human sarcoma cells. The amount of internalised protein and toxicity differed between the different reagents, but the percentage of transduced cells was consistently high. Furthermore, in all protocols the signals of the transduced Atto488-BSA were predominantly punctual consistent with an endosomal localisation. To overcome the endosomal entrapment, the transduction protocols were combined with a photochemical internalisation (PCI) treatment. Using this combination revealed that an endosomal disruption is highly effective in cell penetrating peptide (CPP) mediated transduction, whereas lipid-mediated transductions lead to a lower signal spreading throughout the cytosol. No change in the signal distribution could be achieved in treatments using non-lipid polymers as a transduction reagent. Therefore, the combination of protein transduction protocols based on CPPs with the endosomolytic treatment PCI can facilitate protein transduction experiments in vitro.

  18. A capacitive ultrasonic transducer based on parametric resonance

    Science.gov (United States)

    Surappa, Sushruta; Satir, Sarp; Levent Degertekin, F.

    2017-07-01

    A capacitive ultrasonic transducer based on a parametric resonator structure is described and experimentally demonstrated. The transducer structure, which we call capacitive parametric ultrasonic transducer (CPUT), uses a parallel plate capacitor with a movable membrane as part of a degenerate parametric series RLC resonator circuit with a resonance frequency of fo. When the capacitor plate is driven with an incident harmonic ultrasonic wave at the pump frequency of 2fo with sufficient amplitude, the RLC circuit becomes unstable and ultrasonic energy can be efficiently converted to an electrical signal at fo frequency in the RLC circuit. An important characteristic of the CPUT is that unlike other electrostatic transducers, it does not require DC bias or permanent charging to be used as a receiver. We describe the operation of the CPUT using an analytical model and numerical simulations, which shows drive amplitude dependent operation regimes including parametric resonance when a certain threshold is exceeded. We verify these predictions by experiments with a micromachined membrane based capacitor structure in immersion where ultrasonic waves incident at 4.28 MHz parametrically drive a signal with significant amplitude in the 2.14 MHz RLC circuit. With its unique features, the CPUT can be particularly advantageous for applications such as wireless power transfer for biomedical implants and acoustic sensing.

  19. Electrical capacity and resistance determination of emitting electric transducer

    International Nuclear Information System (INIS)

    Alba Fernandez, J.; Ramis Soriano, J.

    2000-01-01

    In this work we calculate the electrical resistance and capacity of emitting electric transducer, which is mainly formed, in direct relationship with its properties, by a ceramic capacitor. Our aim is to motivate the students with an attractive element in order to carry out traditional measurements of the charge and discharge transients of a capacitor, implementing high resistance setups. (Author) 5 refs

  20. Analysis of the conical piezoelectric acoustic emission transducer

    Czech Academy of Sciences Publication Activity Database

    Červená, Olga; Hora, Petr

    2008-01-01

    Roč. 2, č. 1 (2008), s. 13-24 ISSN 1802-680X R&D Projects: GA ČR GA101/06/1689 Institutional research plan: CEZ:AV0Z20760514 Keywords : acoustic emission * conical transducer * FEM Subject RIV: BI - Acoustics