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Sample records for 125i interstitial brachytherapy

  1. Dose distribution along the transverse axis of a new 125I source for interstitial brachytherapy.

    PubMed

    Nath, R; Yue, N

    2000-11-01

    A new encapsulated source of 125I has been introduced for interstitial brachytherapy. This source, isoSTAR model 12501 (manufactured by Imagyn Corp.), consists of a welded titanium tube containing 125I as silver iodide uniformly coated on five silver beads. The dose rate constant and the radial dose function for this source were measured using lithium fluoride thermoluminescent dosimeters in a Solid Water phantom. The value of the dose rate constant is 0.95 cGy h(-1)U(-1) where the unit of air kerma strength is 1 U = 1 cGy h(-1)cm2. The air kerma strength was traceable to the year 2000 primary air kerma strength standard for the model 12501 source at the National Institute of Technology and Standards. The radial dose function for the source was very similar to that for the model 6711 source (manufactured by Nycomed Amersham) for radial distances up to 6 cm. However, the radial dose function is lower in value than that for the model 6702 source (manufactured by Nycomed Amersham) and the model MED3631-A/M Iogold source (manufactured by North American Scientific). PMID:11128306

  2. Near-field dosimetry of {sup 125}I sources for interstitial brachytherapy implants measured using thermoluminescent sheets

    SciTech Connect

    Iwata, Kazuro; Yue, Ning J.; Nath, Ravinder

    2004-12-01

    The dosimetric characteristics were measured for two types of {sup 125}I low-energy photon-emitting sources by using a wide and highly sensitive thermoluminescent (TL) sheet film, which was developed for two-dimensional dose distribution measurements. The TL film is made of Teflon homogeneously mixed with small powders of thermoluminescence (BaSO{sub 4}:Eu doped). Various dosimetric parameters (i.e., radial dose function, 2D and 1D anisotropy functions) of model 6711 and 6702 {sup 125}I sources were obtained at various distances from the source surfaces to 15 mm. These parameters obtained with TL sheet were compared with the data recommended in the updated AAPM TG-43 report. The radial dose functions measured with TL sheet are in agreement with those established data of model 6711 {sup 125}I seed and model 6702 {sup 125}I seed at most of the distances within 5% and 7%, respectively. All the measured anisotropy functions showed symmetry about the longitudinal source axis. The anisotropy of dose distributions was clearly present in the immediate vicinity of the source edges. The measured 2D anisotropy function values at 1 cm are in reasonably good agreement with the recommended values. The differences at two points in the 1D anisotropy functions measured with TL sheet and the established data at 1 cm from source center were 0.7% and 1.9% for model 6711 and 6702 {sup 125}I sources, respectively; the differences at 0.5 cm were 1.5% and 1.7% for model 6711 and 6702 {sup 125}I sources, respectively. The relative dosimetric characteristics in the vicinity of actual interstitial brachytherapy sources containing {sup 125}I have been experimentally determined by using the TL sheet as a 2D dosimeter.

  3. Monte Carlo and thermoluminescence dosimetry of the new IsoSeed registered model I25.S17 {sup 125}I interstitial brachytherapy seed

    SciTech Connect

    Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Karaiskos, P.; Sandilos, P.; Przykutta, A.; Baltas, D.

    2005-11-15

    Monte Carlo simulation and experimental thermoluminescence dosimetry were utilized for the dosimetric characterization of the new IsoSeed registered model I25.S17 {sup 125}I interstitial brachytherapy seed. The new seed design is similar to that of the selectSeed and 6711 seeds, with the exception of its molybdenum marker. Full dosimetric data are presented following the recommendations in the Update of the AAPM Task Group 43 report (TG-43U1). A difference of 3.3% was found between Monte Carlo dose rate constant results calculated by air kerma strengths from simulations using a point detector and a detector resembling the solid angle subtended to the seed by the Wide Angle Free Air Chamber (WAFAC) in the primary standard calibration geometry. Following the TG-43U1 recommendations, an average value of {lambda}{sub MC}=(0.929{+-}0.014) cGy h{sup -1} U{sup -1} was adopted for the new seed. This value was then averaged with the measured value of {lambda}{sub EXP}=(0.951{+-}0.044) cGy h{sup -1} U{sup -1} to yield the proposed dose rate constant for the new seed that is equal to {lambda}=(0.940{+-}0.051) cGy h{sup -1} U{sup -1}. The Monte Carlo calculated radial dose function and two-dimensional (2-D) anisotropy function results for the new seed were found in agreement with experimental results to within statistical uncertainty of repeated measurements. Monte Carlo simulations were also performed for {sup 125}I seeds of similar geometry and dimensions for the purpose of comparison. The new seed presents dosimetric characteristics that are very similar to that of the selectSeed. In comparison to the most extensively studied Amersham 6711 seed, the new one presents similar dosimetric characteristics with a slightly reduced dose rate constant (1.5%)

  4. [Salvage 125I brachytherapy of locally recurrent prostate cancer].

    PubMed

    Gesztesi, László; Ágoston, Péter; Major, Tibor; Gődény, Mária; Andi, Judit; Lengyel, Zsolt; Polgár, Csaba

    2014-09-01

    The purpose of the study is to report a case of salvage low dose rate (LDR) prostate brachytherapy in a patient with locally recurrent prostate cancer, four years after his first treatment with combined external beam radiation therapy (EBRT) and high dose rate (HDR) brachytherapy. A 61-year-old man was treated with 1x10 Gy HDR brachytherapy and a total of 60 Gy EBRT for an organ confined intermediate risk carcinoma of the prostate in 2009. The patient's tumor had been in regression with the lowest PSA level of 0.09 ng/ml, till the end of 2013. After slow but continuous elevation, his PSA level had reached 1.46 ng/ml by February 2014. Pelvis MRI and whole body acetate PET/CT showed recurrent tumor in the dorsal-right region of the prostate. Bone scan was negative. After discussing the possible salvage treatment options with the patient, he chose LDR brachytherapy. In 2014, in spinal anesthesia 21 125I "seeds" were implanted with transrectal ultrasound guidance into the prostate. The prescribed dose to the whole prostate was 100 Gy, to the volume of the recurrent tumor was 140 Gy. The patient tolerated the salvage brachytherapy well. The postimplant dosimetry was evaluated using magnetic resonance imaging-computed tomography (MR-CT) fusion and appeared satisfactory. PSA level decreased from the pre-salvage value of 1.46 ng/ml to 0.42 ng/ml by one month and 0.18 ng/ml by two months after the brachytherapy. No gastrointestinal side effects appeared, the patient's urination became slightly more frequent. In selected patients, salvage LDR brachytherapy can be a good choice for curative treatment of locally recurrent prostate cancer, after primary radiation therapy. Multiparametric MRI is fundamental, acetate PET/CT can play an important role when defining the localization of the recurrent tumor. PMID:25260087

  5. Bioevaluation of 125I Ocu-Prosta seeds for application in prostate cancer brachytherapy

    PubMed Central

    Mukherjee, Archana; Sarma, Haladhar Dev; Saxena, Sanjay; Kumar, Yogendra; Chaudhari, Pradip; Goda, Jayant Sastri; Adurkar, Pranjal; Dash, Ashutosh; Samuel, Grace

    2014-01-01

    Background & objectives: In recent years, brachytherapy involving permanent radioactive seed implantation has emerged as an effective modality for the management of cancer of prostate. 125I-Ocu-Prosta seeds were indigenously developed and studies were carried out to assess the safety of the indigenously developed 125I-Ocu-Prosta seeds for treatment of prostate cancer. Methods: Animal experiments were performed to assess the likelihood of in vivo release of 125I from radioactive seeds and migration of seeds implanted in the prostate gland of the rabbit. In vivo release of 125I activity was monitored by serial blood sampling from the auricular vein and subsequent measurement of 125I activity. Serial computed tomography (CT) scans were done at regular intervals till 6 months post implant to assess the physical migration of the seeds. Results: The laser welded seeds maintained their hermeticity and prevented the in vivo release of 125I activity into the blood as no radioactivity was detected during follow up blood measurements. Our study showed that the miniature 125I seeds were clearly resolved in CT images. Seeds remained within the prostate gland during the entire study period. Moreover, the seed displacement was minimal even within the prostate gland. Interpretation & conclusions: Our findings have demonstrated that indigenously developed 125I-Ocu-Prosta seeds may be suitable for application in treatment of prostate cancer. PMID:24927341

  6. On the physical, spectral, and dosimetric characteristics of a new {sup 125}I brachytherapy source

    SciTech Connect

    Pirchio, Rosana; Galiano, Eduardo; Saravi, Margarita; Banchik, David; Munoz, Carlos

    2007-07-15

    A new {sup 125}I source under the name Braquibac{sup TM} has been developed in Argentina for interstitial brachytherapy applications. The aim of this work is to study the new seed's design and to calculate its dosimetric parameters. Radiographic and destructive tests were carried out on inactive seeds to determine the physical characteristics of the source. Values of g(r), {lambda}, F(r,{theta}), and {phi}{sub an}(r), were obtained in water and air by simulation using the MCNP5 Monte Carlo code according to the methodology recommended in TG-43 and updated in TG-43U1. The dose rate constant was determined to be 0.937{+-}0.004 cGy h{sup -1} U{sup -1} (overall statistical uncertainty {+-}2.7%). S{sub k} per unity activity was calculated to be 0.671{+-}0.003 cGy cm{sup 2} h{sup -1} mCi{sup -1} by simulation of the seed in dry air using point detectors. Spectroscopic studies for both the new and the Amersham model 6711 seed were performed using an HPGe planar detector. The emission spectra of both seeds proved to be very similar. The anisotropy of the total photon intensity in air was measured in planes containing the seed's short and long axes using the HPGe detector. The minimum photon intensity for the new seed was 31.14{+-}3.10% of the transverse intensity.

  7. Directional interstitial brachytherapy from simulation to application

    NASA Astrophysics Data System (ADS)

    Lin, Liyong

    Organs at risk (OAR) are sometimes adjacent to or embedded in or overlap with the clinical target volume (CTV) to be treated. The purpose of this PhD study is to develop directionally low energy gamma-emitting interstitial brachytherapy sources. These sources can be applied between OAR to selectively reduce hot spots in the OARs and normal tissues. The reduction of dose over undesired regions can expand patient eligibility or reduce toxicities for the treatment by conventional interstitial brachytherapy. This study covers the development of a directional source from design optimization to construction of the first prototype source. The Monte Carlo code MCNP was used to simulate the radiation transport for the designs of directional sources. We have made a special construction kit to assemble radioactive and gold-shield components precisely into D-shaped titanium containers of the first directional source. Directional sources have a similar dose distribution as conventional sources on the treated side but greatly reduced dose on the shielded side, with a sharp dose gradient between them. A three-dimensional dose deposition kernel for the 125I directional source has been calculated. Treatment plans can use both directional and conventional 125I sources at the same source strength for low-dose-rate (LDR) implants to optimize the dose distributions. For prostate tumors, directional 125I LDR brachytherapy can potentially reduce genitourinary and gastrointestinal toxicities and improve potency preservation for low risk patients. The combination of better dose distribution of directional implants and better therapeutic ratio between tumor response and late reactions enables a novel temporary LDR treatment, as opposed to permanent or high-dose-rate (HDR) brachytherapy for the intermediate risk T2b and high risk T2c tumors. Supplemental external-beam treatments can be shortened with a better brachytherapy boost for T3 tumors. In conclusion, we have successfully finished the

  8. Spectroscopic output of {sup 125}I and {sup 103}Pd low dose rate brachytherapy sources

    SciTech Connect

    Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A.

    2009-01-15

    The spectroscopic output of low dose rate (LDR) brachytherapy sources is dependent on the physical design and construction of the source. Characterization of the emitted photons from 12 {sup 125}I and 3 {sup 103}Pd LDR brachytherapy source models is presented. Photon spectra, both along the transverse bisector and at several polar angles, were measured in air with a high-purity reverse electrode germanium (REGe) detector. Measured spectra were corrected to in vacuo conditions via Monte Carlo and analytical methods. The tabulated and plotted spectroscopic data provide a more complete understanding of each source model's output characteristics than can be obtained with other measurement techniques. The variation in fluorescence yield of the {sup 125}I sources containing silver caused greater differences in the emitted spectra and average energies among these seed models than was observed for the {sup 103}Pd sources or the {sup 125}I sources that do not contain silver. Angular spectroscopic data further highlighted the effects of source construction unique to each model, as well as the asymmetric output of many seeds. These data demonstrate the need for the incorporation of such physically measured output characteristics in the Monte Carlo modeling process.

  9. Ejaculatory Function After Permanent {sup 125}I Prostate Brachytherapy for Localized Prostate Cancer

    SciTech Connect

    Huyghe, Eric Delannes, Martine; Wagner, Fabien M.; Delaunay, Boris; Nohra, Joe; Thoulouzan, Matthieu; Shut-Yee, J. Yeung; Plante, Pierre; Soulie, Michel; Thonneau, Patrick; Bachaud, Jean Marc

    2009-05-01

    Purpose: Ejaculatory function is an underreported aspect of male sexuality in men treated for prostate cancer. We conducted the first detailed analysis of ejaculatory function in patients treated with permanent {sup 125}I prostate brachytherapy for localized prostate cancer. Patients and Methods: Of 270 sexually active men with localized prostate cancer treated with permanent {sup 125}I prostate brachytherapy, 241 (89%), with a mean age of 65 years (range, 43-80), responded to a mailed questionnaire derived from the Male Sexual Health Questionnaire regarding ejaculatory function. Five aspects of ejaculatory function were examined: frequency, volume, dry ejaculation, pleasure, and pain. Results: Of the 241 sexually active men, 81.3% had conserved ejaculatory function after prostate brachytherapy; however, the number of patients with rare/absent ejaculatory function was double the pretreatment number (p < .0001). The latter finding was correlated with age (p < .001) and the preimplant International Index of Erectile Function score (p < .001). However, 84.9% of patients with maintained ejaculatory function after implantation reported a reduced volume of ejaculate compared with 26.9% before (p < .001), with dry ejaculation accounting for 18.7% of these cases. After treatment, 30.3% of the patients experienced painful ejaculation compared with 12.9% before (p = .0001), and this was associated with a greater number of implanted needles (p = .021) and the existence of painful ejaculation before implantation (p < .0001). After implantation, 10% of patients who continued to be sexually active experienced no orgasm compared with only 1% before treatment. in addition, more patients experienced late/difficult or weak orgasms (p = .001). Conclusion: Most men treated with brachytherapy have conserved ejaculatory function after prostate brachytherapy. However, most of these men experience a reduction in volume and a deterioration in orgasm.

  10. Differential dose contributions on total dose distribution of 125I brachytherapy source

    PubMed Central

    Camgöz, B.; Yeğin, G.; Kumru, M.N.

    2010-01-01

    This work provides an improvement of the approach using Monte Carlo simulation for the Amersham Model 6711 125I brachytherapy seed source, which is well known by many theoretical and experimental studies. The source which has simple geometry was researched with respect to criteria of AAPM Tg-43 Report. The approach offered by this study involves determination of differential dose contributions that come from virtual partitions of a massive radioactive element of the studied source to a total dose at analytical calculation point. Some brachytherapy seeds contain multi-radioactive elements so the dose at any point is a total of separate doses from each element. It is momentous to know well the angular and radial dose distributions around the source that is located in cancerous tissue for clinical treatments. Interior geometry of a source is effective on dose characteristics of a distribution. Dose information of inner geometrical structure of a brachytherapy source cannot be acquired by experimental methods because of limits of physical material and geometry in the healthy tissue, so Monte Carlo simulation is a required approach of the study. EGSnrc Monte Carlo simulation software was used. In the design of a simulation, the radioactive source was divided into 10 rings, partitioned but not separate from each other. All differential sources were simulated for dose calculation, and the shape of dose distribution was determined comparatively distribution of a single-complete source. In this work anisotropy function was examined also mathematically. PMID:24376927

  11. Feasibility and Clinical Value of CT-guided (125)I Brachytherapy for Bilateral Lung Recurrences from Colorectal Carcinoma.

    PubMed

    Wang, Guobao; Zhang, Fujun; Yang, Bin; Xue, Jingbing; Peng, Sheng; Zhong, Zhihui; Zhang, Tao; Lu, Mingjian; Gao, Fei

    2016-03-01

    Purpose To prospectively evaluate the feasibility and clinical value of computed tomography (CT)-guided iodine 125 ((125)I) brachytherapy to treat bilateral lung recurrences from colorectal carcinoma. Materials and Methods This study was approved by Sun Yat-sen University Cancer Center Institutional Review Board and all patients provided informed written consent. Seventy-two patients with bilateral lung recurrences from colorectal carcinoma were enrolled and randomly divided into two groups. Thirty-three were percutaneously treated with CT-guided (125)I brachytherapy (group A) and the other 39 were only given symptomatic and supportive treatments (group B). Follow-up contrast agent-enhanced CT scans were reviewed and efficacy of treatment was evaluated. (125)I brachytherapy was considered a success if it achieved the computerized treatment planning system criteria 1 month after procedure. Analyses included Kaplan-Meier, Mantel-Cox log-rank test, and Cox proportional hazards regression. Results In group A, 37 (125)I brachytherapy procedures were performed in 33 patients with 126 lung metastatic lesions and the success rate was 87.9% (29 of 33 patients). The local control rate of 3, 6, 12, 24, and 36 months was 75.8%, 51.5%, 33.3%, 24.2%, and 9.1%, respectively. A small amount of pulmonary hematoma occurred in five patients, and six patients presented with pneumothorax with pulmonary compression of 30%-40%. No massive bleeding or radiation pneumonitis occurred. The mean overall survival (OS) of group A was significantly longer than that of group B, and (125)I brachytherapy was an independent factor that affected the OS (group A, 18.8 months; group B, 8.6 months; hazard ratio, 0.391 [95% confidence interval: 0.196, 0.779]; P = .008). Conclusion CT-guided (125)I brachytherapy is feasible and safe for the treatment of bilateral lung recurrences from colorectal carcinoma. (©) RSNA, 2015. PMID:26406550

  12. Monte Carlo dosimetry for {sup 125}I and {sup 103}Pd eye plaque brachytherapy

    SciTech Connect

    Thomson, R. M.; Taylor, R. E. P.; Rogers, D. W. O.

    2008-12-15

    A Monte Carlo study of dosimetry for eye plaque brachytherapy is performed. BrachyDose, an EGSnrc user code which makes use of Yegin's multi-geometry package, is used to fully model {sup 125}I (model 6711) and {sup 103}Pd (model 200) brachytherapy seeds and the standardized plaques of the Collaborative Ocular Melanoma Study (COMS). Three-dimensional dose distributions in the eye region are obtained. In general, dose to water is scored; however, the implications of replacing water with eye tissues are explored. The effect of the gold alloy (Modulay) backing is investigated and the dose is found to be sensitive to the elemental composition of the backing. The presence of the silicone polymer (Silastic) seed carrier results in substantial dose decreases relative to water, particularly for {sup 103}Pd. For a 20 mm plaque with a Modulay backing and Silastic insert, fully loaded with 24 seeds, the dose decrease relative to water is of the order of 14% for {sup 125}I and 20% for {sup 103}Pd at a distance of 1 cm from the inner sclera along the plaque's central axis. For the configurations of seeds used in COMS plaques, interseed attenuation is a small effect within the eye region. The introduction of an air interface results in a dose reduction in its vicinity which depends on the plaque's position within the eye and the radionuclide. Introducing bone in the eye's vicinity also causes dose reductions. The dose distributions in the eye for the two different radionuclides are compared and, for the same prescription dose, {sup 103}Pd generally offers a lower dose to critical normal structures. BrachyDose is sufficiently fast to allow full Monte Carlo dose calculations for routine clinical treatment planning.

  13. Radiation complications and tumor control after {sup 125}I plaque brachytherapy for ocular melanoma

    SciTech Connect

    Jensen, Ashley W.; Petersen, Ivy A. . E-mail: petersen.ivy@mayo.edu; Kline, Robert W.; Stafford, Scott L.; Schomberg, Paula J.; Robertson, Dennis M.

    2005-09-01

    Purpose: To determine the outcome of {sup 125}I plaque brachytherapy at our institution and identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis. Patients and Methods: From 1986 to 2000, 156 patients underwent {sup 125}I episcleral plaque (COMS design) application for the treatment of ocular melanoma. Chart analysis of follow-up ophthalmologic appointments assessed the incidence of ocular side effects after therapy. Statistical analysis assessed outcomes and significant influencing factors. Results: With a median follow-up of 6.2 years, the 5-year overall survival was 83%. The 5-year disease-specific survival was 91%. Initial local control at 5 years was 92%, with 100% ultimate local control after secondary therapy that included 9 enucleations. The risk of metastasis was 10% at 5 years and 27% at 10 years. Vision stayed the same or improved in 25% of patients, and 44% of patients maintained visual acuity better than 20/200. Thirteen percent of patients experienced chronic pain or discomfort in the treated eye. Dose rates to the tumor apex greater than 90 to 100 cGy/h were associated with increased systemic control but worse radiation toxicity. Conclusion: Patients in our series experienced excellent local tumor control. Higher dose rates to the tumor apex were associated with reduced rates of distant metastases but worse ocular function.

  14. Concurrent versus sequential application of ferromagnetic hyperthermia and 125I brachytherapy of melanoma in an animal model.

    PubMed Central

    Mieler, W F

    1997-01-01

    OBJECTIVE: To determine the efficacy of concurrent versus sequential ferromagnetic hyperthermia (FMH), combined with Iodine-125 (125I) brachytherapy, in the treatment of uveal melanoma in a rabbit model. MATERIALS AND METHODS: A Greene melanoma cell line was implanted in rabbit eyes to establish a tumor model comparable to a uveal melanoma. Seventy-one tumor-containing rabbit eyes were treated with 125I brachytherapy at 20, 25, 35, 45, or 55 Gray (Gy)(38 eyes), and with either concurrent (15 eyes) or sequential (18 eyes) FMH, delivered at 48.2 degrees C for 1 hour. An additional 13 eyes were treated with FMH alone at 48.2 degrees C, either in a single heat application (5 eyes), or in a repetitive mode (8 eyes). The radiation and heat were delivered via an episcleral plaque. All tumors were followed with indirect ophthalmoscopy and echography. RESULTS: Tumors treated with 125I brachytherapy alone exhibited complete tumor regression in 50% of eyes at 42 Gy with none of the tumors responding to less than 35 Gy. FMH alone at 48.2 degrees C applied in one cycle limited tumor growth in 20% of eyes, while all eyes treated with repetitive heating exhibited complete tumor control. With concurrent application of FMH and 125I, the 50% tumor control rate occurred at 9.5 Gy, thus resulting in a thermal enhancement ratio (TER) of 4.4. With sequential treatment, the 50% tumor control rate was at 30 Gy, with a resultant TER of 1.4. No complications related to 125I brachytherapy were noted in any eyes, while transient retinal whitening was seen with the FMH. CONCLUSION: This study documents the enhanced synergistic interaction of concurrent FMH and 125I brachytherapy, compared to sequential treatment, in this rabbit melanoma model. PMID:9440189

  15. Dose rate constant and energy spectrum of interstitial brachytherapy sources.

    PubMed

    Chen, Z; Nath, R

    2001-01-01

    In the past two years, several new manufacturers have begun to market low-energy interstitial brachytherapy seeds containing 125I and 103Pd. Parallel to this development, the National Institute of Standards and Technology (NIST) has implemented a modification to the air-kerma strength (S(K)) standard for 125I seeds and has also established an S(K) standard for 103Pd seeds. These events have generated a considerable number of investigations on the determination of the dose rate constants (inverted V) of interstitial brachytherapy seeds. The aim of this work is to study the general properties underlying the determination of dose rate constant and to develop a simple method for a quick and accurate estimation of dose rate constant. As the dose rate constant of clinical seeds is defined at a fixed reference point, we postulated that dose rate constant may be calculated by treating the seed as an effective point source when the seed's source strength is specified in S(K) and its source characteristics are specified by the photon energy spectrum measured in air at the reference point. Using a semi-analytic approach, an analytic expression for dose rate constant was derived for point sources with known photon energy spectra. This approach enabled a systematic study of dose rate constant as a function of energy. Using the measured energy spectra, the calculated dose rate constant for 125I model 6711 and 6702 seeds and for 192Ir seed agreed with the AAPM recommended values within +/-1%. For the 103Pd model 200 seed, the agreement was 5% with a recently measured value (within the +/-7% experimental uncertainty) and was within 1% with the Monte Carlo simulations. The analytic expression for dose rate constant proposed here can be evaluated using a programmable calculator or a simple spreadsheet and it provides an efficient method for checking the measured dose rate constant for any interstitial brachytherapy seed once the energy spectrum of the seed is known. PMID:11213926

  16. Ocular brachytherapy dosimetry for 103Pd and 125I in the presence of gold nanoparticles: a Monte Carlo study.

    PubMed

    Asadi, Somayeh; Vaez-Zadeh, Mehdi; Vahidian, Mohammad; Marghchouei, Mahdieh; Masoudi, S Farhad

    2016-01-01

    The aim of the present Monte Carlo study is to evaluate the variation of energy deposition in healthy tissues in the human eye which is irradiated by brachytherapy sources in comparison with the resultant dose increase in the gold nanoparticle (GNP)-loaded choroidal melanoma. The effects of these nanoparticles on normal tissues are compared between 103Pd and 125I as two ophthalmic brachytherapy sources. Dose distribution in the tumor and healthy tissues has been taken into account for both brachytherapy sources. Also, in certain points of the eye, the ratio of the absorbed dose by the normal tissue in the presence of GNPs to the absorbed dose by the same point in the absence of GNPs has been calculated. In addition, differences of the absorbed dose in the tumor observed in the comparison of simple water phantom and actual simulated human eye in presence of GNPs are also a matter of interest that have been considered in the present work. The difference between the eye globe and the water phantom is more obvious for 125I than that of the 103Pd when the ophthalmic dosimetry is done in the presence of GNPs. Whenever these nanoparticles are utilized in enhancing the absorbed dose by the tumor, the use of 125I brachytherapy source will greatly amplify the amount of dose enhancement factor (DEF) in the tumor site without inflicting much dam-age to healthy organs, when compared to the 103Pd source. For instance, in the concentration of 30 mg GNPs, the difference amongst the calculated DEF for 125I between these phantoms is 5.3%, while it is 2.45% for 103Pd. Furthermore, in Monte Carlo studies of eye brachytherapy, more precise definition of the eye phantom instead of a water phantom will become increasingly important when we use 125I as opposed to 103Pd. PMID:27167265

  17. Model-based dose calculations for {sup 125}I lung brachytherapy

    SciTech Connect

    Sutherland, J. G. H.; Furutani, K. M.; Garces, Y. I.; Thomson, R. M.

    2012-07-15

    Purpose: Model-baseddose calculations (MBDCs) are performed using patient computed tomography (CT) data for patients treated with intraoperative {sup 125}I lung brachytherapy at the Mayo Clinic Rochester. Various metallic artifact correction and tissue assignment schemes are considered and their effects on dose distributions are studied. Dose distributions are compared to those calculated under TG-43 assumptions. Methods: Dose distributions for six patients are calculated using phantoms derived from patient CT data and the EGSnrc user-code BrachyDose. {sup 125}I (GE Healthcare/Oncura model 6711) seeds are fully modeled. Four metallic artifact correction schemes are applied to the CT data phantoms: (1) no correction, (2) a filtered back-projection on a modified virtual sinogram, (3) the reassignment of CT numbers above a threshold in the vicinity of the seeds, and (4) a combination of (2) and (3). Tissue assignment is based on voxel CT number and mass density is assigned using a CT number to mass density calibration. Three tissue assignment schemes with varying levels of detail (20, 11, and 5 tissues) are applied to metallic artifact corrected phantoms. Simulations are also performed under TG-43 assumptions, i.e., seeds in homogeneous water with no interseed attenuation. Results: Significant dose differences (up to 40% for D{sub 90}) are observed between uncorrected and metallic artifact corrected phantoms. For phantoms created with metallic artifact correction schemes (3) and (4), dose volume metrics are generally in good agreement (less than 2% differences for all patients) although there are significant local dose differences. The application of the three tissue assignment schemes results in differences of up to 8% for D{sub 90}; these differences vary between patients. Significant dose differences are seen between fully modeled and TG-43 calculations with TG-43 underestimating the dose (up to 36% in D{sub 90}) for larger volumes containing higher proportions of

  18. Evaluation of the dosimetric parameters for 125I brachytherapy determined in prostate medium using CT images.

    PubMed

    Hanada, Takashi; Yorozu, Atsunori; Ohashi, Toshio; Shigematsu, Naoyuki; Maruyama, Koichi

    2010-01-01

    In the present study, the prostate medium determined from the CT images of 149 patients was developed. The dosimetric parameters such as Λ, g(L)(r) and F(r, θ) used in TG-43U1-based calculation for an iodine-125 ((125)I) brachytherapy-source were examined using Monte Carlo code Geant4. Clinical dosimetry parameters such as the D(90) were evaluated among a subgroup of 50 randomly selected patients who had been treated with permanent brachytherapy between January 2008 and December 2008 at the Tokyo Medical Center. The results show a slight difference in the dose rate constant Λ (within 1.0%). The radial dose function g(L)(r) exhibits a prominent difference in the region over 3 cm, and this difference is maintained within 2.9% in the region close to the source. The calculated values of F(r, θ) for the prostate medium were similar to values for water (within 1%), except in the longitudinal axis. A comparison of D(90) values shows a systematic dose overestimation of 2.8 ± 0.7 Gy in water, where the distribution of the differences can be seen with a spread of 1.8 ± 0.3% compared to that in prostate medium. It was concluded that the introduction of any kind of tissue correction for the TG-43U1-based calculation was not necessary to allow for the differences in elemental compositions and densities between water and prostate medium. PACS number: 87.00.00; 87.55.dk; 87.55.K-; 87.56.B-. PMID:20921822

  19. New National Air-Kerma-Strength Standards for 125I and 103Pd Brachytherapy Seeds

    PubMed Central

    Seltzer, Stephen M.; Lamperti, Paul J.; Loevinger, Robert; Mitch, Michael G.; Weaver, James T.; Coursey, Bert M.

    2003-01-01

    The new U.S. measurement standard for the air-kerma strength from low-energy photon-emitting brachytherapy seed sources is formally described in detail. This instrument-based standard was implemented on 1 January 1999, with its salient features and the implications of differences with the previous standard given only through a series of informal communications. The Wide-Angle Free-Air Chamber (WAFAC) is specially designed to realize air kerma from a single-seed source emitting photons with energies up to about 40 keV, and is now used to measure the wide variety of seeds used in prostate-cancer therapy that has appeared in the last few years. For the two 125I seed models that have been subject to both the old and new standards, the new standard reduces the air-kerma strength by 10.3 %. This change is mainly due to the removal of the influence on the measurement of the Ti K x rays produced in the source encapsulation, a component with no clinical significance.

  20. Localization of linked {sup 125}I seeds in postimplant TRUS images for prostate brachytherapy dosimetry

    SciTech Connect

    Xue Jinyu . E-mail: Jinyu.Xue@mail.tju.edu; Waterman, Frank; Handler, Jay; Gressen, Eric

    2005-07-01

    Purpose: To demonstrate that {sup 125}I seeds can be localized in transrectal ultrasound (TRUS) images obtained with a high-resolution probe when the implant is performed with linked seeds and spacers. Adequate seed localization is essential to the implementation of TRUS-based intraoperative dosimetry for prostate brachytherapy. Methods and Materials: Thirteen preplanned peripherally loaded prostate implants were performed using {sup 125}I seeds and spacers linked together in linear arrays that prevent seed migration and maintain precise seed spacing. A set of two-dimensional transverse images spaced at 0.50-cm intervals were obtained with a high-resolution TRUS probe at the conclusion of the procedure with the patient still under anesthesia. The image set extended from 1.0 cm superior to the base to 1.0 cm inferior to the apex. The visible echoes along each needle track were first localized and then compared with the known construction of the implanted array. The first step was to define the distal and proximal ends of each array. The visible echoes were then identified as seeds or spacers from the known sequence of the array. The locations of the seeds that did not produce a visible echo were interpolated from their known position in the array. A CT scan was obtained after implantation for comparison with the TRUS images. Results: On average, 93% (range, 86-99%) of the seeds were visible in the TRUS images. However, it was possible to localize 100% of the seeds in each case, because the locations of the missing seeds could be determined from the known construction of the arrays. Two factors complicated the interpretation of the TRUS images. One was that the spacers also produced echoes. Although weak and diffuse, these echoes could be mistaken for seeds. The other was that the number of echoes along a needle track sometimes exceeded the number of seeds and spacers implanted. This was attributed to the overall length of the array, which was approximately 0.5 cm

  1. Brain damage from sup 125 I brachytherapy evaluated by MR imaging, a blood-brain barrier tracer, and light and electron microscopy in a rat model

    SciTech Connect

    Bernstein, M.; Marotta, T.; Stewart, P.; Glen, J.; Resch, L.; Henkelman, M. )

    1990-10-01

    Changes in normal rat brain were studied acutely, and at 3, 6, 9, and 12 months following interstitial brachytherapy with high-activity {sup 125}I seeds. An 80-Gy radiation dose was administered to an area with a 5.5-mm radius. Effects were measured with magnetic resonance (MR) imaging (with and without gadolinium enhancement), leakage of horseradish peroxidase (HRP), electron microscopy, and light microscopy. Significant histological damage was seen at radiation doses above 295 Gy, and breakdown of the blood-brain barrier was observed only in tissue receiving a dose of 165 Gy or greater. Blood-brain barrier breakdown increased up to the 6-month time point, and thereafter appeared to stabilize or decrease. The area of blood-brain barrier disruption indicated by gadolinium-enhanced MR imaging was greater than that indicated by leakage of HRP.

  2. A comparison study on various low energy sources in interstitial prostate brachytherapy

    PubMed Central

    Bakhshabadi, Mahdi; Ghorbani, Mahdi; Knaup, Courtney; Meigooni, Ali S.

    2016-01-01

    Purpose Low energy sources are routinely used in prostate brachytherapy. 125I is one of the most commonly used sources. Low energy 131Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of 125I, 103Pd, and 131Cs sources in interstitial brachytherapy of prostate. Material and methods ProstaSeed 125I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of 103Pd and 131Cs were simulated with the same geometry as the ProstaSeed 125I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Results Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, 131Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the 103Pd source. Conclusions The higher initial absolute dose in cGy/(h.U) of 131Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the 103Pd source are advantages of this later brachytherapy source. Based on the total dose the 125I source has advantage over the others due to its longer half-life. PMID:26985200

  3. Effect of /sup 125/I interstitial radiotherapy on blood-brain barrier function in normal canine brain

    SciTech Connect

    Groothuis, D.R.; Wright, D.C.; Ostertag, C.B.

    1987-12-01

    Blood-brain barrier (BBB) function was studied in 14 normal dogs at time periods from 7 to 717 days after permanent insertion of 5- to 7-mCi seeds of iodine-125 (/sup 125/I) for interstitial radiation. The BBB function was measured with carbon-14-labeled alpha aminoisobutyric acid (AIB) and quantitative autoradiography, and expressed as a unidirectional blood-to-brain transfer constant, K. The /sup 125/I radiation lesions consisted of three concentric histologically and functionally distinct zones: 1) a central zone of calcified necrosis; 2) a spongy fluid-filled zone; and 3) a narrow rim (2.6 +/- 0.6 mm wide) of viable brain tissue with increased permeability. Within this rim, the mean value of the K of AIB was 5.8 times that of normal cortex. Over the 7- to 392-day time period the value of K remained rather constant, and by 716 days K values had returned to normal. There was moderate regional variation in the value of K; it was highest in the white matter and lowest in the gray matter surrounding the radiation lesion. The radiation lesion progressively increased in size from 7 to 80 days, after which there was little change. This study illustrates that the geographically circumscribed radiation from /sup 125/I seeds is accompanied by similarly well-defined changes in BBB function, which may persist for over 1 year following insertion of the /sup 125/I seed. This altered BBB function is probably responsible for the cerebral edema associated with /sup 125/I interstitial radiotherapy.

  4. New material for low-dose brachytherapy seeds: Xe-doped amorphous carbon films with post-growth neutron activated 125I.

    PubMed

    Gonçalves, R G F; Pinheiro, M V B; Lacerda, R G; Ferlauto, A S; Ladeira, L O; Krambrock, K; Leal, A S; Viana, G A; Marques, F C

    2011-01-01

    We report a novel material for use in (125)I brachytherapy that consists of amorphous carbon films grown by ion-beam-assisted deposition and doped with Xe (5 at%) by implantation. Samples of these films grown on Si substrates were irradiated with neutrons in a TRIGA-I nuclear reactor for the production (125)Xe, and latter characterized by gamma spectroscopy. The results indicate that the (124)Xe was efficiently converted into (125)Xe, the precursor of (125)I, and support the activity calculations for a model brachytherapy seed. PMID:20729094

  5. 125I brachytherapy in the palliation of painful bone metastases from lung cancer after failure or rejection of conventional treatments

    PubMed Central

    Gilani, Saba; Zhong, Zhihui; Zhang, Tao; Zhang, Fujun; Gao, Fei

    2016-01-01

    Purpose This study sought to assess the safety and effect of 125I seed implantation for palliation of painful bone metastases from lung cancer after failure or rejection of conventional treatments. Materials and Methods 89 patients with painful bone metastases secondary to lung cancer were consented and enrolled in this study from June 2013 to May 2015. All patients had failed or refused conventional treatments underwent percutaneous CT-guided 125I seed implantation. The Brief Pain Inventory (BPI) was used to measure pain intensity prior to treatment (T0), 2, 4, 6, 8 and 12 weeks (T2, T4, T6, T8 and T12) after treatment in a 24-hour period. Analgesic, quality of life (QOL) scores and complications were also recorded. Four patients were excluded as they were lost to follow-up or had incomplete data. Results 85 patients with 126 bone metastases from lung cancer were treated. There were significantly lower scores after treatment in the visual analog scale (VAS) and analgesic. The VAS scores for worst pain was 6.3±1.8 at T0. At T2, T4, T6, T8 and T12, the score in a 24-hour period decreased to 4.9±1.2 (P<0.01), 3.7±1.3 (P<0.01), 3.4±1.2 (P<0.01), 2.6±0.9 (P<0.01), and 1.4±0.8 (P<0.01) respectively. Comparison of QOL scores showed improvements including sleep, appetite, spiritual state, and fatigue at T2, T4, T6, T8 and T12 when compared to T0. No serious complications or massive bleeding were observed. Conclusions 125I brachytherapy is a safe and effective method for palliation of painful bone metastases from lung cancer after failure or rejection of conventional treatments. PMID:26919235

  6. Health-Related Quality of Life up to Six Years After {sup 125}I Brachytherapy for Early-Stage Prostate Cancer

    SciTech Connect

    Roeloffzen, Ellen M.A.; Lips, Irene M.; Gellekom, Marion P.R. van; Roermund, Joep van; Frank, Steven J.; Battermann, Jan J.; Vulpen, Marco van

    2010-03-15

    Purpose: Health-related quality of life (HRQOL) after prostate brachytherapy has been extensively described in published reports but hardly any long-term data are available. The aim of the present study was to prospectively assess long-term HRQOL 6 years after {sup 125}I prostate brachytherapy. Methods and Materials: A total of 127 patients treated with {sup 125}I brachytherapy for early-stage prostate cancer between December 2000 and June 2003 completed a HRQOL questionnaire at five time-points: before treatment and 1 month, 6 months, 1 year, and 6 years after treatment. The questionnaire included the RAND-36 generic health survey, the cancer-specific European Organization for Research and Treatment of Cancer core questionnaire (EORTCQLQ-C30), and the tumor-specific EORTC prostate cancer module (EORTC-PR25). A change in a score of >=10 points was considered clinically relevant. Results: Overall, the HRQOL at 6 years after {sup 125}I prostate brachytherapy did not significantly differ from baseline. Although a statistically significant deterioration in HRQOL at 6 years was seen for urinary symptoms, bowel symptoms, pain, physical functioning, and sexual activity (p <.01), most changes were not clinically relevant. A statistically significant improvement at 6 years was seen for mental health, emotional functioning, and insomnia (p <.01). The only clinically relevant changes were seen for emotional functioning and sexual activity. Conclusion: This is the first study presenting prospective HRQOL data up to 6 years after {sup 125}I prostate brachytherapy. HRQOL scores returned to approximately baseline values at 1 year and remained stable up to 6 years after treatment. {sup 125}I prostate brachytherapy did not adversely affect patients' long-term HRQOL.

  7. An overview of interstitial brachytherapy and hyperthermia

    SciTech Connect

    Brandt, B.B.; Harney, J.

    1989-11-01

    Interstitial thermoradiotherapy, an experimental cancer treatment that combines interstitial radiation implants (brachytherapy) and interstitial hyperthermia, is in the early stages of investigation. In accordance with the procedure used in a current national trial protocol, a 60-minute hyperthermia treatment is administered after catheters are placed into the tumor area while the patient is under general anesthesia. This is immediately followed by loading of radioactive Iridium-192 seeds into the catheters for a defined period of time. Once the prescribed radiation dose is delivered, the radioactive sources are removed and a second, 60-minute hyperthermia treatment is administered. Clinical trials with hyperthermia in combination with radiation have increased in recent years. Nurses caring for these patients need to become more knowledgeable about this investigational therapy. This paper provides an overview of the biologic rationale for this therapy, as well as a description of the delivery method and clinical application. Specific related nursing interventions are defined in a nursing protocol.23 references.

  8. Modified COMS Plaques for {sup 125}I and {sup 103}Pd Iris Melanoma Brachytherapy

    SciTech Connect

    Thomson, Rowan M.; Furutani, Keith M.; Pulido, Jose S.; Stafford, Scott L.; Rogers, D.W.O.

    2010-11-15

    Purpose: Novel plaques are used to treat iris melanoma at the Mayo Clinic Rochester. The plaques are a modification of the Collaborative Ocular Melanoma Study (COMS) 22 mm plaque design with a gold alloy backing, outer lip, and silicone polymer insert. An inner lip surrounds a 10 mm diameter cutout region at the plaque center. Plaques span 360{sup o}, 270{sup o}, and 180{sup o} arcs. This article describes dosimetry for these plaques and others used in the treatment of anterior eye melanomas. Methods and Materials: The EGSnrc user-code BrachyDose is used to perform Monte Carlo simulations. Plaques and seeds are fully modeled. Three-dimensional dose distributions for different plaque models, TG-43 calculations, and {sup 125}I (model 6711) and {sup 103}Pd (model 200) seeds are compared via depth-dose curves, tabulation of doses at points of interest, and isodose contours. Results: Doses at points of interest differ by up to 70% from TG-43 calculations. The inner lip reduces corneal doses. Matching plaque arc length to tumor extent reduces doses to eye regions outside the treatment area. Maintaining the same prescription dose, {sup 103}Pd offers lower doses to critical structures than {sup 125}I, with the exception of the sclera adjacent to the plaque. Conclusion: The Mayo Clinic plaques offer several advantages for anterior eye tumor treatments. Doses to regions outside the treatment area are significantly reduced. Doses differ considerably from TG-43 predictions, illustrating the importance of complete Monte Carlo simulations. Calculations take a few minutes on a single CPU, making BrachyDose sufficiently fast for routine clinical treatment planning.

  9. Monte Carlo and experimental dosimetry of an {sup 125}I brachytherapy seed

    SciTech Connect

    Dolan, James; Li Zuofeng; Williamson, Jeffrey F.

    2006-12-15

    We have performed a comprehensive dosimetric characterization of the Oncura{sup TM} model 6711 {sup 125}I seed using both experimental [LiF thermoluminscent dosimetry (TLD)] and theoretical (Monte Carlo photon transport) methods. In addition to determining the dosimetric parameters of the 6711, this report quantified: (1) the angular dependence of LiF TLD energy response functions for both point and volume detectors in water, poly(methylmethacrylate), and solid water media; and (2) the contribution of underlying geometric uncertainties to the overall uncertainty of Monte Carlo derived dosimetric parameters according to the National Institute of Standards and Technology Report 1297 methodology. The theoretical value for the dose rate constant in water was 0.942 cGy U{sup -1} h{sup -1}{+-}1.76% [combined standard uncertainty (CSU) with coverage factor k=1] and the experimental value was 0.971 cGy U{sup -1} h{sup -1}{+-}6.1%. Agreement between experimental and theoretical radial dose function values was well within the k=1 CSU, while agreement between experimental and theoretical anisotropy function values was within the k=1 CSU only after incorporating the use of polar angle-dependent energy response functions. The angular dependence of the relative energy response was found to have a complex and significant dependence on measurement medium and internal geometry of the source.

  10. Comparison of 3 different postimplant dosimetry methods following permanent {sup 125}I prostate seed brachytherapy

    SciTech Connect

    Marcu, Loredana G.; Gowda, Raghu

    2013-10-01

    Postimplant dosimetry (PID) after Iodine-125 ({sup 125}I) implant of the prostate should offer a reliable qualitative assessment. So far, there is no consensus regarding the optimum PID method, though the latest literature is in favor of magnetic resonance imaging (MRI). This study aims to simultaneously compare 3 PID techniques: (1) MRI-computed tomography (CT) fusion; (2) ultrasound (US)-CT fusion; and (3) manual target delineation on CT. The study comprised 10 patients with prostate cancer. CT/MR scans with urinary catheters in place for PID were done either on day 0 or day 1 postimplantation. The main parameter evaluated and compared among methods was target D90. The results show that CT-based D90s are lower than US-CT D90s (median difference,−6.85%), whereas MR-CT PID gives higher D90 than US-CT PID (median difference, 4.25%). Manual contouring on CT images tends to overestimate the prostate volume compared with transrectal ultrasound (TRUS) (median difference, 23.33%), whereas on US images the target is overestimated compared with MR-based contouring (median difference, 13.25%). Although there are certain differences among the results given by various PID techniques, the differences are statistically insignificant for this small group of patients. Any dosimetric comparison between 2 PID techniques should also account for the limitations of each technique, to allow for an accurate quantification of data. Given that PID after permanent radioactive seed implant is mandatory for quality assurance, any imaging method–based PID (MR-CT, US-CT, and CT) available in a radiotherapy department can be indicative of the quality of the procedure.

  11. Relative biological effectiveness enhancement of a 125I brachytherapy seed with characteristic x rays from its constitutive materials.

    PubMed

    Taschereau, Richard; Roy, René; Pouliot, Jean

    2002-07-01

    The isotopes used for permanent prostate implants, 125I and 103Pd, provide about equivalent tumor control. The purpose of this study is to investigate how characteristic x rays may be used to raise the relative biological effectiveness (RBE) of an iodine seed at short distances to increase the differential effect between tumor and healthy tissue. Within the theoretical framework of microdosimetry, the GEANT4 Monte Carlo simulation toolkit has been used to calculate the RBE of experimental seed designs in which shell and core dimensions and composition were varied independently. A new seed model was also simulated based on the best results obtained. The RBE could be enhanced by increasing the shell thickness and for the range considered, optimum results were obtained by using gradually lower atomic number elements. For a practical 50-60 microm shell, molybdenum is the material of choice. The core diameter has little influence on RBE, but maximum effectiveness is obtained with yttrium or zirconium. These results were put together to design a Mo-shell and Y-core seed for which the RBE enhancement was at least 5-7% (close to the source), which is higher than palladium. This enhanced RBE combined with the longer half-life of iodine could mean comparable tumor control and better protection to organs at risk than with current seeds. The RBE dependence on distance is an interesting feature that could benefit other applications such as ocular melanoma or coronary brachytherapy where a highly localized dose distribution is desired. PMID:12148718

  12. Alpha 1-Adrenoceptor Blocker May Improve Not Only Voiding But Also Storage Lower Urinary Tract Symptoms Caused by 125I Brachytherapy for Prostate Cancer

    PubMed Central

    Aoki, Yoshitaka; Ito, Hideaki; Miwa, Yoshiji; Akino, Hironobu; Shioura, Hiroki; Kimura, Hirohiko; Yokoyama, Osamu

    2014-01-01

    Purpose. To assess changes in lower urinary tract symptoms (LUTS) within 1 year after brachytherapy in patients receiving alpha 1-adrenoceptor antagonists. Methods. We retrospectively evaluated 116 patients who underwent 125I prostate brachytherapy in our institute. Seventy-one patients were treated with a combination of external beam radiation therapy and brachytherapy. Alpha 1-adrenoceptor antagonists were prescribed to all patients after brachytherapy. International Prostate Symptom Score (IPSS) forms and postvoid residual urine volume were recorded at all follow-up visits. Results. Forty-nine patients were given tamsulosin hydrochloride, 32 were given silodosin hydrochloride, and 35 were given naftopidil for up to 6 months after seed implantation. Patients given tamsulosin or naftopidil tended to show a higher peak IPSS and slower recovery to baseline values than those given silodosin. The patients given naftopidil showed an insufficient recovery in storage symptoms in naftopidil group in comparison with tamsulosin group at 3 months and with silodosin group at 6 and 9 months. Conclusions. In the management of LUT after brachytherapy, silodosin may provide a more favorable improvement. Silodosin and tamsulosin may have an advantage in improving not only voiding but also storage lower urinary tract symptoms after brachytherapy. PMID:25006516

  13. Interstitial rotating shield brachytherapy for prostate cancer

    SciTech Connect

    Adams, Quentin E. Xu, Jinghzu; Breitbach, Elizabeth K.; Li, Xing; Rockey, William R.; Kim, Yusung; Wu, Xiaodong; Flynn, Ryan T.; Enger, Shirin A.

    2014-05-15

    Purpose: To present a novel needle, catheter, and radiation source system for interstitial rotating shield brachytherapy (I-RSBT) of the prostate. I-RSBT is a promising technique for reducing urethra, rectum, and bladder dose relative to conventional interstitial high-dose-rate brachytherapy (HDR-BT). Methods: A wire-mounted 62 GBq{sup 153}Gd source is proposed with an encapsulated diameter of 0.59 mm, active diameter of 0.44 mm, and active length of 10 mm. A concept model I-RSBT needle/catheter pair was constructed using concentric 50 and 75 μm thick nickel-titanium alloy (nitinol) tubes. The needle is 16-gauge (1.651 mm) in outer diameter and the catheter contains a 535 μm thick platinum shield. I-RSBT and conventional HDR-BT treatment plans for a prostate cancer patient were generated based on Monte Carlo dose calculations. In order to minimize urethral dose, urethral dose gradient volumes within 0–5 mm of the urethra surface were allowed to receive doses less than the prescribed dose of 100%. Results: The platinum shield reduced the dose rate on the shielded side of the source at 1 cm off-axis to 6.4% of the dose rate on the unshielded side. For the case considered, for the same minimum dose to the hottest 98% of the clinical target volume (D{sub 98%}), I-RSBT reduced urethral D{sub 0.1cc} below that of conventional HDR-BT by 29%, 33%, 38%, and 44% for urethral dose gradient volumes within 0, 1, 3, and 5 mm of the urethra surface, respectively. Percentages are expressed relative to the prescription dose of 100%. For the case considered, for the same urethral dose gradient volumes, rectum D{sub 1cc} was reduced by 7%, 6%, 6%, and 6%, respectively, and bladder D{sub 1cc} was reduced by 4%, 5%, 5%, and 6%, respectively. Treatment time to deliver 20 Gy with I-RSBT was 154 min with ten 62 GBq {sup 153}Gd sources. Conclusions: For the case considered, the proposed{sup 153}Gd-based I-RSBT system has the potential to lower the urethral dose relative to HDR-BT by 29

  14. Effect of improved TLD dosimetry on the determination of dose rate constants for {sup 125}I and {sup 103}Pd brachytherapy seeds

    SciTech Connect

    Rodriguez, M.; Rogers, D. W. O.

    2014-11-01

    Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for {sup 125}I and {sup 103}Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f{sup rel}, for TLDs and the phantom correction, P{sub phant}, are calculated for {sup 125}I and {sup 103}Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced by calculated (f{sup rel}){sup −1} and P{sub phant} values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k{sub bq}{sup rel}, is determined. The new P{sub phant} values and relative absorbed-dose sensitivities, S{sub AD}{sup rel}, calculated as the product of (f{sup rel}){sup −1} and (k{sub bq}{sup rel}){sup −1}, are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f{sup rel} is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among {sup 125}I and {sup 103}Pd seed models and common TLD shapes. P{sub phant} values depend primarily on the isotope used. Deduced (k{sub bq}{sup rel}){sup −1} values are 1.074 ± 0.015 and 1.084 ± 0.026 for {sup 125}I and {sup 103}Pd seeds, respectively. For (1 mm){sup 3} chips, this implies an overall absorbed-dose sensitivity relative to {sup 60}Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for {sup 125}I and {sup 103}Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P{sub phant} calculated here have much lower statistical uncertainties than literature values, but

  15. New 125I brachytherapy source IsoSeed I25.S17plus: Monte Carlo dosimetry simulation and comparison to sources of similar design

    PubMed Central

    Pantelis, Evaggelos; Anagnostopoulos, Giorgos; Baltas, Dimos

    2013-01-01

    Purpose To determine the relative dose rate distribution around the new 125I brachytherapy source IsoSeed I25.S17plus and report results in a form suitable for clinical use. Results for the new source are also compared to corresponding results for other commercially available 125I sources of similar design. Material and methods Monte Carlo simulations were performed using the MCNP5 v.1.6 general purpose code. The model of the new source was prepared from information provided by the manufacturer and verified by imaging a sample of ten non-radioactive sources. Corresponding simulations were also performed for the 6711 125I brachytherapy source, using updated geometric information presented recently in the literature. The uncertainty of the dose distribution around the new source, as well as the dosimetric quantities derived from it according to the Task Group 43 formalism, were determined from the standard error of the mean of simulations for a sample of fifty source models. These source models were prepared by randomly selecting values of geometric parameters from uniform distributions defined by manufacturer stated tolerances. Results and Conclusions Results are presented in the form of the quantities defined in the update of the Task Group 43 report, as well as a relative dose rate table in Cartesian coordinates. The dose rate distribution of the new source is comparable to that of sources of similar design (IsoSeed I25.S17, Oncoseed 6711, SelectSeed 130.002, Advantage IAI-125A, I-Seed AgX100, Thinseed 9011). Noticeable differences were observed only for the IsoSeed I25.S06 and Best 2301 sources. PMID:24474975

  16. Cluster pattern analysis of energy deposition sites for the brachytherapy sources 103Pd, 125I, 192Ir, 137Cs, and 60Co

    NASA Astrophysics Data System (ADS)

    Villegas, Fernanda; Tilly, Nina; Bäckström, Gloria; Ahnesjö, Anders

    2014-09-01

    Analysing the pattern of energy depositions may help elucidate differences in the severity of radiation-induced DNA strand breakage for different radiation qualities. It is often claimed that energy deposition (ED) sites from photon radiation form a uniform random pattern, but there is indication of differences in RBE values among different photon sources used in brachytherapy. The aim of this work is to analyse the spatial patterns of EDs from 103Pd, 125I, 192Ir, 137Cs sources commonly used in brachytherapy and a 60Co source as a reference radiation. The results suggest that there is both a non-uniform and a uniform random component to the frequency distribution of distances to the nearest neighbour ED. The closest neighbouring EDs show high spatial correlation for all investigated radiation qualities, whilst the uniform random component dominates for neighbours with longer distances for the three higher mean photon energy sources (192Ir, 137Cs, and 60Co). The two lower energy photon emitters (103Pd and 125I) present a very small uniform random component. The ratio of frequencies of clusters with respect to 60Co differs up to 15% for the lower energy sources and less than 2% for the higher energy sources when the maximum distance between each pair of EDs is 2 nm. At distances relevant to DNA damage, cluster patterns can be differentiated between the lower and higher energy sources. This may be part of the explanation to the reported difference in RBE values with initial DSB yields as an endpoint for these brachytherapy sources.

  17. Monte Carlo calculations and experimental measurements of the TG-43U1-recommended dosimetric parameters of 125I (Model IR-Seed2) brachytherapy source.

    PubMed

    Sheikholeslami, Sahar; Nedaie, Hasan Ali; Sadeghi, Mahdi; Pourbeigi, Hossein; Shahzadi, Sohrab; Zehtabian, Mehdi; Hasani, Mohsen; Meigooni, Ali S

    2016-01-01

    A new design of 125I (Model IR-Seed2) brachytherapy source has been manufactured recently at the Applied Radiation Research School, Nuclear Science and Technology Research Institute in Iran. The source consists of six resin beads (0.5 mm diameter) that are sealed in a cylindrical titanium capsule of 0.7 mm internal and 0.8 mm external diameters. This work aims to evaluate the dosimetric parameters of the newly designed 125I source using experimental measurements and Monte Carlo (MC) simulations. Dosimetric characteristics (dose rate constant, radial dose function, and 2D and 1D anisotropy functions) of the IR-Seed2 were determined using experimental measurements and MC simulations following the recommendations by the Task Group 43 (TG-43U1) report of the American Association of Physicists in Medicine (AAPM). MC simulations were performed using the MCNP5 code in water and Plexiglas, and experimental measurements were carried out using thermoluminescent dosimeters (TLD-GR207A) in Plexiglas phantoms. The measured dose to water in Plexiglas data were used for verification of the accuracy of the source and phantom geometry in the Monte Carlo simulations. The final MC simulated data to water in water were recommended for clinical applications. The MC calculated dose rate constant (Λ) of the IR-Seed2 125I seed in water was found to be 0.992 ± 0.025 cGy h-1U-1. Additionally, its radial dose function by line and point source approximations, gL(r) and gp(r), calculated for distances from 0.1 cm to 7 cm. The values of gL(r) at radial distances from 0.5 cm to 5 cm were measured in a Plexiglas phantom to be between 1.212 and 0.413. The calculated and measured of values for 2D anisotropy function, F(r, θ), were obtained for the radial distances ranging from 1.5 cm to 5 cm and angular range of 0°-90° in a Plexiglas phantom. Also, the 2D anisotropy function was calculated in water for the clinical application. The results of these investigations show that the uncertainty of

  18. Determination of the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters for {sup 125}I and {sup 103}Pd brachytherapy sources relative to {sup 60}Co

    SciTech Connect

    Reed, J. L. Micka, J. A.; Culberson, W. S.; DeWerd, L. A.; Rasmussen, B. E.; Davis, S. D.

    2014-12-15

    Purpose: To determine the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters (TLD-100) for {sup 125}I and {sup 103}Pd brachytherapy sources relative to {sup 60}Co. Methods: LiF:Mg,Ti TLDs were irradiated with low-energy brachytherapy sources and with a {sup 60}Co teletherapy source. The brachytherapy sources measured were the Best 2301 {sup 125}I seed, the OncoSeed 6711 {sup 125}I seed, and the Best 2335 {sup 103}Pd seed. The TLD light output per measured air-kerma strength was determined for the brachytherapy source irradiations, and the TLD light output per air kerma was determined for the {sup 60}Co irradiations. Monte Carlo (MC) simulations were used to calculate the dose-to-TLD rate per air-kerma strength for the brachytherapy source irradiations and the dose to TLD per air kerma for the {sup 60}Co irradiations. The measured and MC-calculated results for all irradiations were used to determine the TLD intrinsic energy dependence for {sup 125}I and {sup 103}Pd relative to {sup 60}Co. Results: The relative TLD intrinsic energy dependences (relative to {sup 60}Co) and associated uncertainties (k = 1) were determined to be 0.883 ± 1.3%, 0.870 ± 1.4%, and 0.871 ± 1.5% for the Best 2301 seed, OncoSeed 6711 seed, and Best 2335 seed, respectively. Conclusions: The intrinsic energy dependence of TLD-100 is dependent on photon energy, exhibiting changes of 13%–15% for {sup 125}I and {sup 103}Pd sources relative to {sup 60}Co. TLD measurements of absolute dose around {sup 125}I and {sup 103}Pd brachytherapy sources should explicitly account for the relative TLD intrinsic energy dependence in order to improve dosimetric accuracy.

  19. Approaches to calculating AAPM TG-43 brachytherapy dosimetry parameters for 137Cs, 125I, 192Ir, 103Pd, and 169Yb sources.

    PubMed

    Melhus, Christopher S; Rivard, Mark J

    2006-06-01

    Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides 137Cs, 125I, 192Ir, 103Pd, and 169Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of phantom size, mode of radiation transport physics--i.e., photon transport only or coupled photon:electron transport, phantom material, volume averaging, and Monte Carlo tally type were studied. For noninfinite media, g(r) was found to degrade as r approached R, the phantom radius. MCNP5 results were in agreement with those published using GEANT4. Brachytherapy dosimetry parameters calculated using coupled photon:electron radiation transport simulations did not differ significantly from those using photon transport only. Dose distributions from low-energy photon-emitting radionuclides 125I and 103Pd were sensitive to phantom material by upto a factor of 1.4 and 2.0, respectively, between tissue-equivalent materials and water at r =9 cm. In comparison, high-energy photons from 137Cs, 192Ir, and 169Yb demonstrated +/- 5% differences in dose distributions between water and tissue substitutes at r=20 cm. Similarly, volume-averaging effects were found to be more significant for low-energy radionuclides. When modeling line sources with L < or = 0.5 cm, the two-dimensional anisotropy function was largely within +/- 0.5% of unity for 137Cs, 125I, and 192Ir. However, an energy and geometry effect was noted for 103Pd and 169Yb, with Pd-103F(0.5,0 degrees)=l.05 and yb-169F(0.5,0 degrees)=0.98 for L=0.5 cm. Simulations of monoenergetic photons for L=0.5 cm produced energy-dependent variations in F(r, theta) having a maximum value at 10 keV, minimum at 50 keV, and approximately 1.0 for higher-energy photons up to 750 keV. Both the F6 cell heating and *F4 track-length estimators were employed to determine brachytherapy dosimetry parameters. F6 was found to be necessary

  20. Approaches to calculating AAPM TG-43 brachytherapy dosimetry parameters for {sup 137}Cs, {sup 125}I, {sup 192}Ir, {sup 103}Pd, and {sup 169}Yb sources

    SciTech Connect

    Melhus, Christopher S.; Rivard, Mark J.

    2006-06-15

    Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides {sup 137}Cs, {sup 125}I, {sup 192}Ir, {sup 103}Pd, and {sup 169}Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of phantom size, mode of radiation transport physics--i.e., photon transport only or coupled photon:electron transport, phantom material, volume averaging, and Monte Carlo tally type were studied. For noninfinite media, g(r) was found to degrade as r approached R, the phantom radius. MCNP5 results were in agreement with those published using GEANT4. Brachytherapy dosimetry parameters calculated using coupled photon:electron radiation transport simulations did not differ significantly from those using photon transport only. Dose distributions from low-energy photon-emitting radionuclides {sup 125}I and {sup 103}Pd were sensitive to phantom material by upto a factor of 1.4 and 2.0, respectively, between tissue-equivalent materials and water at r=9 cm. In comparison, high-energy photons from {sup 137}Cs, {sup 192}Ir, and {sup 169}Yb demonstrated {+-}5% differences in dose distributions between water and tissue substitutes at r=20 cm. Similarly, volume-averaging effects were found to be more significant for low-energy radionuclides. When modeling line sources with L{<=}0.5 cm, the two-dimensional anisotropy function was largely within {+-}0.5% of unity for {sup 137}Cs, {sup 125}I, and {sup 192}Ir. However, an energy and geometry effect was noted for {sup 103}Pd and {sup 169}Yb, with {sub Pd-103}F(0.5,0 deg.)=1.05 and {sub Yb-169}F(0.5,0 deg.)=0.98 for L=0.5 cm. Simulations of monoenergetic photons for L=0.5 cm produced energy-dependent variations in F(r,{theta}) having a maximum value at 10 keV, minimum at 50 keV, and {approx}1.0 for higher-energy photons up to 750 keV. Both the F6 cell heating and track-length estimators were

  1. Monte Carlo dosimetry for {sup 103}Pd, {sup 125}I, and {sup 131}Cs ocular brachytherapy with various plaque models using an eye phantom

    SciTech Connect

    Lesperance, Marielle; Martinov, M.; Thomson, R. M.

    2014-03-15

    Purpose: To investigate dosimetry for ocular brachytherapy for a range of eye plaque models containing{sup 103}Pd, {sup 125}I, or {sup 131}Cs seeds with model-based dose calculations. Methods: Five representative plaque models are developed based on a literature review and are compared to the standardized COMS plaque, including plaques consisting of a stainless steel backing and acrylic insert, and gold alloy backings with: short collimating lips and acrylic insert, no lips and silicone polymer insert, no lips and a thin acrylic layer, and individual collimating slots for each seed within the backing and no insert. Monte Carlo simulations are performed using the EGSnrc user-code BrachyDose for single and multiple seed configurations for the plaques in water and within an eye model (including nonwater media). Simulations under TG-43 assumptions are also performed, i.e., with the same seed configurations in water, neglecting interseed and plaque effects. Maximum and average doses to ocular structures as well as isodose contours are compared for simulations of each radionuclide within the plaque models. Results: The presence of the plaque affects the dose distribution substantially along the plaque axis for both single seed and multiseed simulations of each plaque design in water. Of all the plaque models, the COMS plaque generally has the largest effect on the dose distribution in water along the plaque axis. Differences between doses for single and multiple seed configurations vary between plaque models and radionuclides. Collimation is most substantial for the plaque with individual collimating slots. For plaques in the full eye model, average dose in the tumor region differs from those for the TG-43 simulations by up to 10% for{sup 125}I and {sup 131}Cs, and up to 17% for {sup 103}Pd, and in the lens region by up to 29% for {sup 125}I, 34% for {sup 103}Pd, and 28% for {sup 131}Cs. For the same prescription dose to the tumor apex, the lowest doses to critical

  2. Computerized Tomography: Its Role in Interstitial Brachytherapy of Pelvic Malignancies

    PubMed Central

    Kumar, P. Pradeep; Taylor, Judith; Jones, E.O.; McAnulty, Bruce

    1986-01-01

    The advantages of computerized tomography (CT) in the treatment planning of external beam radiation therapy have been shown in several studies. The authors extended the use of CT to the interstitial brachytherapy treatment planning of pelvic malignancies. CT was found to be invaluable in localizing pelvic tumors, selecting implant techniques, and checking the accuracy of the implant. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:3950985

  3. Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma

    PubMed Central

    Zhang, Weixing; Cai, Xiaobo; Chen, Dafan; Wan, Xinjian

    2016-01-01

    125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost. PMID:26840346

  4. Urinary Symptom Flare in 712 {sup 125}I Prostate Brachytherapy Patients: Long-Term Follow-Up

    SciTech Connect

    Keyes, Mira; Miller, Stacy; Moravan, Veronika; Pickles, Tom; Liu, Mitchell; Spadinger, Ingrid; Lapointe, Vincent; Morris, W. James

    2009-11-01

    Purpose: To describe the late transient worsening of urinary symptoms ('urinary symptom flare') in 712 consecutive prostate brachytherapy patients, associated predictive factors, association with rectal and urinary toxicity, and the development of erectile dysfunction. Methods and Materials: Patients underwent implantation between 1998 and 2003 (median follow-up, 57 months). International Prostate Symptom Score (IPSS), Radiation Therapy Oncology Group (RTOG) toxicity, and erectile function data were prospectively collected. Flare was defined as an increase in IPSS of >=5 and of >=8 points greater than the post-treatment nadir. The relationships between the occurrence of flare and the patient, tumor, and treatment characteristics were examined. The Cox proportional hazards method was used to test individual variables and the multivariate models. Results: The incidence of flare was 52% and 30% using the flare definition of an IPSS of >=5 and >=8 points greater than the postimplant nadir, respectively. Of the patients with symptoms, 65% had resolution of their symptoms within 6 months and 91% within 1 year. Flares most commonly occurred 16-24 months after implantation. On multivariate analysis, a greater baseline IPSS and greater maximal postimplant IPSS were the predictors of flare, regardless of the flare definition used. Androgen suppression was a predictor for fewer flares (IPSS >=5). Diabetes and prostate edema predicted for more frequent flares (IPSS >=8). Patients with flare had a greater incidence of RTOG Grade 3 urinary toxicity and RTOG Grade 2 or greater rectal toxicity. No association was found between erectile dysfunction and the occurrence of flare. Conclusion: Urinary symptom flare is a common, transient phenomenon after prostate brachytherapy. A greater baseline IPSS and maximal postimplant IPSS were the strongest predictive factors. Flare was associated with a greater incidence of late RTOG Grade 3 urinary toxicity and greater rate of late RTOG Grade

  5. Evaluating the Phoenix Definition of Biochemical Failure After {sup 125}I Prostate Brachytherapy: Can PSA Kinetics Distinguish PSA Failures From PSA Bounces?

    SciTech Connect

    Thompson, Anna; Keyes, Mira; Pickles, Tom

    2010-10-01

    Purpose: To evaluate the prostate-specific antigen (PSA) kinetics of PSA failure (PSAf) and PSA bounce (PSAb) after permanent {sup 125}I prostate brachytherapy (PB). Methods and Materials: The study included 1,006 consecutive low and 'low tier' intermediate-risk patients treated with {sup 125}I PB, with a potential minimum follow-up of 4 years. Patients who met the Phoenix definition of biochemical failure (nadir + 2 ng/mL{sup -1}) were identified. If the PSA subsequently fell to {<=}0.5 ng/mL{sup -1}without intervention, this was considered a PSAb. All others were scored as true PSAf. Patient, tumor and dosimetric characteristics were compared between groups using the chi-square test and analysis of variance to evaluate factors associated with PSAf or PSAb. Results: Median follow-up was 54 months. Of the 1,006 men, 57 patients triggered the Phoenix definition of PSA failure, 32 (56%) were true PSAf, and 25 PSAb (44%). The median time to trigger nadir + 2 was 20.6 months (range, 6-36) vs. 49 mo (range, 12-83) for PSAb vs. PSAf groups (p < 0.001). The PSAb patients were significantly younger (p < 0.0001), had shorter time to reach the nadir (median 6 vs. 11.5 months, p = 0.001) and had a shorter PSA doubling time (p = 0.05). Men younger than age 70 who trigger nadir +2 PSA failure within 38 months of implant have an 80% likelihood of having PSAb and 20% chance of PSAf. Conclusions: With adequate follow-up, 44% of PSA failures by the Phoenix definition in our cohort were found to be benign PSA bounces. Our study reinforces the need for adequate follow-up when reporting PB PSA outcomes, to ensure accurate estimates of treatment efficacy and to avoid unnecessary secondary interventions.

  6. Long-Term Efficacy and Toxicity of Low-Dose-Rate {sup 125}I Prostate Brachytherapy as Monotherapy in Low-, Intermediate-, and High-Risk Prostate Cancer

    SciTech Connect

    Kittel, Jeffrey A.; Reddy, Chandana A.; Smith, Kristin L.; Stephans, Kevin L.; Tendulkar, Rahul D.; Ulchaker, James; Angermeier, Kenneth; Campbell, Steven; Stephenson, Andrew; Klein, Eric A.; Wilkinson, D. Allan; Ciezki, Jay P.

    2015-07-15

    Purpose/Objectives: To report long-term efficacy and toxicity for a single-institution cohort of patients treated with low-dose-rate prostate brachytherapy permanent implant (PI) monotherapy. Methods and Materials: From 1996 to 2007, 1989 patients with low-risk (61.3%), intermediate-risk (29.8%), high-intermediate-risk (4.5%), and high-risk prostate cancer (4.4%) were treated with PI and followed up prospectively in a registry. All patients were treated with {sup 125}I monotherapy to 144 Gy. Late toxicity was coded retrospectively according to a modified Common Terminology Criteria for Adverse Events 4.0 scale. The rates of biochemical relapse-free survival (bRFS), distant metastasis-free survival (DMFS), overall survival (OS), and prostate cancer–specific mortality (PCSM) were calculated. We identified factors associated with late grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity, bRFS, DMFS, OS, PCSM, and incontinence. Results: The median age of the patients was 67 years, and the median overall and prostate-specific antigen follow-up times were 6.8 years and 5.8 years, respectively. The overall 5-year rates for bRFS, DMFS, OS, and PCSM were 91.9%, 97.8%, 93.7%, and 0.71%, respectively. The 10-year rates were 81.5%, 91.5%, 76.1%, and 2.5%, respectively. The overall rates of late grade ≥3 GU and GI toxicity were 7.6% and 0.8%, respectively. On multivariable analysis, age and prostate length were significantly associated with increased risk of late grade ≥3 GU toxicity. The risk of incontinence was highly correlated with both pre-PI and post-PI transurethral resection of the prostate. Conclusions: Prostate brachytherapy as monotherapy is an effective treatment for low-risk and low-intermediate-risk prostate cancer and appears promising as a treatment for high-intermediate-risk and high-risk prostate cancer. Significant long-term toxicities are rare when brachytherapy is performed as monotherapy.

  7. Prophylactic tamsulosin (Flomax) in patients undergoing prostate {sup 125}I brachytherapy for prostate carcinoma: Final report of a double-blind placebo-controlled randomized study

    SciTech Connect

    Elshaikh, Mohamed A.; Ulchaker, James C.; Reddy, Chandana A.; Angermeier, Kenneth W.; Klein, Eric A.; Chehade, Nabil; Altman, Andrew; Ciezki, Jay P. . E-mail: ciezkj@ccf.org

    2005-05-01

    Purpose: To evaluate the effectiveness of prophylactic tamsulosin (Flomax) in reducing the urinary symptoms in patients undergoing {sup 125}I prostate implantation (PI) for prostate adenocarcinoma. Methods and materials: This is a single-institution, double-blind, placebo-controlled, randomized trial for patients undergoing PI for prostate adenocarcinoma comparing prophylactic tamsulosin versus placebo. Eligibility criteria included patients not taking tamsulosin or other {alpha}-blockers treated with PI. The patients were randomly assigned to either tamsulosin (0.8 mg, orally once a day) or matched placebo. All patients started the medication 4 days before PI and continued for 60 days. The American Urologic Association (AUA) symptom index questionnaire was used to assess urinary symptoms. The AUA questionnaire was administered before PI for a baseline score and weekly for 8 weeks after PI. Patients were taken off the study if they developed urinary retention, had intolerable urinary symptoms, or wished to discontinue with the trial. Results: One hundred twenty-six patients were enrolled in this study from November 2001 to January 2003 (118 were evaluable: 58 in the tamsulosin arm and 60 in the placebo group). Pretreatment and treatment characteristics were comparably matched between the two groups. The urinary retention rate was 17% (10 patients) in the placebo group compared with 10% (6 patients) in the tamsulosin group (p = 0.3161). Eighty-eight percent (14 patients) of those who developed urinary retention experienced it within 2 weeks after the PI. Intolerable urinary symptoms were reported equally (10 patients in each group) with 70% occurring in the first 2 weeks after PI. There was a significant difference in mean AUA score in favor of tamsulosin at Week 5 after PI (p = 0.03). Conclusions: Prophylactic tamsulosin (0.8 mg/day) before prostate brachytherapy did not significantly affect urinary retention rates, but had a positive effect on urinary morbidity at

  8. Impact of prostate edema on cell survival and tumor control after permanent interstitial brachytherapy for early stage prostate cancers

    PubMed Central

    Chen, Zhe (Jay); Roberts, Kenneth; Decker, Roy; Pathare, Pradip; Rockwell, Sara; Nath, Ravinder

    2011-01-01

    Previous studies have shown that the procedure-induced prostate edema during permanent interstitial brachytherapy (PIB) can cause significant variations in the dose delivered to the prostate gland. Because the clinical impact of edema-induced dose variations depends strongly on the magnitude of the edema, the temporal pattern of its resolution and its interplay with the decay of radioactivity and the underlying biological processes of tumor cells (such as tumor potential doubling time), we investigated the impact of edema-induced dose variations on the tumor cell survival and tumor control probability after PIB with the 131Cs, 125I and 103Pd sources used in current clinical practice. The exponential edema resolution model reported by Waterman et al. (Int. J. Radiat. Oncol. Biol. Phys. 41, 1069–1077–1998) was used to characterize the edema evolutions observed previously during clinical PIB for prostate cancer. The concept of biologically effective dose (BED), taking into account tumor cell proliferation and sublethal damage repair during dose delivery, was used to characterize the effects of prostate edema on cell survival and tumor control probability. Our calculation indicated that prostate edema, if not taken into account appropriately, can increase the cell survival and decrease the probability of local control of PIB. The edema-induced increase in cell survival increased with increasing edema severity, decreasing half-life for radioactive decay and decreasing energy of the photons energy emitted by the source. At the doses currently prescribed for PIB and for prostate cancer cells characterized by nominal radiobiology parameters recommended by AAPM TG-137, PIB using 125I sources was less affected by edema than PIB using 131Cs or 103Pd sources due to the long radioactive decay half-life of 125I. The effect of edema on PIB using 131Cs or 103Pd was similar. The effect of edema on 103Pd PIB was slightly greater, even though the decay half-life of 103Pd (17 days

  9. The impact of prostate edema on cell survival and tumor control after permanent interstitial brachytherapy for early stage prostate cancers

    NASA Astrophysics Data System (ADS)

    (Jay Chen, Zhe; Roberts, Kenneth; Decker, Roy; Pathare, Pradip; Rockwell, Sara; Nath, Ravinder

    2011-08-01

    Previous studies have shown that procedure-induced prostate edema during permanent interstitial brachytherapy (PIB) can cause significant variations in the dose delivered to the prostate gland. Because the clinical impact of edema-induced dose variations strongly depends on the magnitude of the edema, the temporal pattern of its resolution and its interplay with the decay of radioactivity and the underlying biological processes of tumor cells (such as tumor potential doubling time), we investigated the impact of edema-induced dose variations on the tumor cell survival and tumor control probability after PIB with the 131Cs, 125I and 103Pd sources used in current clinical practice. The exponential edema resolution model reported by Waterman et al (1998 Int. J. Radiat. Oncol. Biol. Phys. 41 1069-77) was used to characterize the edema evolutions previously observed during clinical PIB for prostate cancer. The concept of biologically effective dose, taking into account tumor cell proliferation and sublethal damage repair during dose delivery, was used to characterize the effects of prostate edema on cell survival and tumor control probability. Our calculation indicated that prostate edema, if not appropriately taken into account, can increase the cell survival and decrease the probability of local control of PIB. The magnitude of an edema-induced increase in cell survival increased with increasing edema severity, decreasing half-life of radioactive decay and decreasing photon energy emitted by the source. At the doses currently prescribed for PIB and for prostate cancer cells characterized by nominal radiobiology parameters recommended by AAPM TG-137, PIB using 125I sources was less affected by edema than PIB using 131Cs or 103Pd sources due to the long radioactive decay half-life of 125I. The effect of edema on PIB using 131Cs or 103Pd was similar. The effect of edema on 103Pd PIB was slightly greater, even though the decay half-life of 103Pd (17 days) is longer than

  10. Dose estimation for different skin models in interstitial breast brachytherapy

    PubMed Central

    Kabacińska, Renata; Makarewicz, Roman

    2014-01-01

    Purpose Skin is a major organ at risk in breast-conserving therapy (BCT). The American Brachytherapy Society (ABS) recommendations require monitoring of maximum dose received, however, there is no unambiguous way of skin contouring provided. The purpose of this study was to compare the doses received by the skin in different models. Material and methods Standard treatment plans of 20 patients who underwent interstitial breast brachytherapy were analyzed. Every patient had a new treatment plan prepared according to Paris system and had skin contoured in three different ways. The first model, Skin 2 mm, corresponds to the dermatological breast skin thickness and is reaching 2 mm into an external patient contour. It was rejected in a further analysis, because of distinct discontinuities in contouring. The second model, Skin 4 mm, replaced Skin 2 mm, and is reaching 2 mm inside and 2 mm outside of the External contour. The third model, Skin EXT, is created on the External contour and it expands 4 mm outside. Doses received by the most exposed 0.1 cc, 1 cc, 2 cc, and the maximum doses for Skin 4 mm and Skin EXT were compared. Results Mean, median, maximum, and standard deviation of percentage dose difference between Skin EXT and Skin 4 mm for the most exposed 0.1 cc (D0.1cc) of skin were 18.01%, 17.20%, 27.84%, and 4.01%, respectively. All differences were statistically significant (p < 0.05). Conclusions Monitoring of doses received by skin is necessary to avoid complications and obtain a satisfactory cosmetic effect. It is difficult to assess the compatibility of treatment plans with recommendations, while there is no unambiguous way of skin contouring. Especially, if a mean difference of doses between two models of skin contouring is 18% for the most exposed 0.1 cc and can reach almost 28% in some cases. Differences of this magnitude can result in skin complications during BCT. PMID:25097562

  11. A comparison of the dose distributions between the brachytherapy 125I source models, STM1251 and Oncoseed 6711, in a geometry lacking radiation equilibrium scatter conditions.

    PubMed

    Tanaka, Kenichi; Kamo, Ken-ichi; Tateoka, Kunihiko; Asanuma, Osamu; Sato, Kaori; Takeda, Hiromitsu; Sakata, Koh-ichi; Takada, Jun

    2015-03-01

    The purpose of this study was to estimate the uncertainty in the dose distribution for the (125)I source STM1251, as measured with a radiophotoluminescent glass rod dosimeter and calculated using the Monte Carlo code EGS5 in geometry that included the source structure reported by Kirov et al. This was performed at a range of positions in and on a water phantom 18 cm in diameter and 16 cm in length. Some dosimetry positions were so close to the surface that the backscatter margin was insufficient for photons. Consequently, the combined standard uncertainty (CSU) at the coverage factor k of 1 was 11.0-11.2% for the measurement and 1.8-3.6% for the calculation. The calculation successfully reproduced the measured dose distribution within 13%, with CSU at k ≤ 1.6 (P > 0.3). Dose distributions were then compared with those for the (125)I source Oncoseed 6711. Our results supported the American Association of Physicists in Medicine Task Group No. 43 Updated Protocol (TG43U1) formalism, in which STM1251 dose distributions were more penetrating than those of Oncoseed 6711. This trend was also observed in the region near the phantom surface lacking the equilibrium radiation scatter conditions. In this region, the difference between the TG43U1 formalism and the measurement and calculation performed in the present study was not significant (P > 0.3) for either of the source models. Selection of the source model based on the treatment plans according to the TG43U1 formalism will be practical. PMID:25618137

  12. Dose optimization in gynecological 3D image based interstitial brachytherapy using martinez universal perineal interstitial template (MUPIT) -an institutional experience

    PubMed Central

    Sharma, Pramod Kumar; Sharma, Praveen Kumar; Swamidas, Jamema V; Mahantshetty, Umesh; Deshpande, D. D.; Manjhi, Jayanand; Rai, D V

    2014-01-01

    The aim of this study was to evaluate the dose optimization in 3D image based gynecological interstitial brachytherapy using Martinez Universal Perineal Interstitial Template (MUPIT). Axial CT image data set of 20 patients of gynecological cancer who underwent external radiotherapy and high dose rate (HDR) interstitial brachytherapy using MUPIT was employed to delineate clinical target volume (CTV) and organs at risk (OARs). Geometrical and graphical optimization were done for optimum CTV coverage and sparing of OARs. Coverage Index (CI), dose homogeneity index (DHI), overdose index (OI), dose non-uniformity ratio (DNR), external volume index (EI), conformity index (COIN) and dose volume parameters recommended by GEC-ESTRO were evaluated. The mean CTV, bladder and rectum volume were 137 ± 47cc, 106 ± 41cc and 50 ± 25cc, respectively. Mean CI, DHI and DNR were 0.86 ± 0.03, 0.69 ± 0.11 and 0.31 ± 0.09, while the mean OI, EI, and COIN were 0.08 ± 0.03, 0.07 ± 0.05 and 0.79 ± 0.05, respectively. The estimated mean CTV D90 was 76 ± 11Gy and D100 was 63 ± 9Gy. The different dosimetric parameters of bladder D2cc, D1cc and D0.1cc were 76 ± 11Gy, 81 ± 14Gy, and 98 ± 21Gy and of rectum/recto-sigmoid were 80 ± 17Gy, 85 ± 13Gy, and 124 ± 37Gy, respectively. Dose optimization yields superior coverage with optimal values of indices. Emerging data on 3D image based brachytherapy with reporting and clinical correlation of DVH parameters outcome is enterprizing and provides definite assistance in improving the quality of brachytherapy implants. DVH parameter for urethra in gynecological implants needs to be defined further. PMID:25190999

  13. Indication for Interstitial Brachytherapy in Carcinoma of the Uterine Cervix

    PubMed Central

    Kumar, P. Pradeep; Taylor, Judith; Scott, Joseph C.; Jacobs, Allan J.; Rojas, John

    1984-01-01

    More than 40 patients with gynecological, genitourinary, and gastrointestinal malignancies, both primary and recurrent but confined to the pelvis, were treated with interstitial irradiation over a four-year period. Interstitial irradiation was the choice of treatment for early carcinoma of the prostate, carcinoma of the anal canal less than T2, recurrent carcinoma of the uterine cervix, and carcinoma of the cervical stump. The authors' experience in treating recurrent carcinoma of the uterine cervix with interstitial irradiation is the basis for the indications for selecting the technique of interstitial irradiation presented. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 10 PMID:6471113

  14. Comparison of Prophylactic Naftopidil, Tamsulosin, and Silodosin for {sup 125}I Brachytherapy-Induced Lower Urinary Tract Symptoms in Patients With Prostate Cancer: Randomized Controlled Trial

    SciTech Connect

    Tsumura, Hideyasu; Satoh, Takefumi; Ishiyama, Hiromichi; Tabata, Ken-ichi; Kotani, Shouko; Minamida, Satoru; Kimura, Masaki; Fujita, Tetsuo; Matsumoto, Kazumasa; Kitano, Masashi; Hayakawa, Kazushige; Baba, Shiro

    2011-11-15

    Purpose: To compare the efficacy of three {alpha}{sub 1A}/{alpha}{sub 1D}-adrenoceptor (AR) antagonists-naftopidil, tamsulosin, and silodosin-that have differing affinities for the {alpha}{sub 1}-AR subtypes in treating urinary morbidities in Japanese men with {sup 125}I prostate implantation (PI) for prostate cancer. Methods and Materials: This single-institution prospective randomized controlled trial compared naftopidil, tamsulosin, and silodosin in patients undergoing PI. Patients were randomized and received either naftopidil, tamsulosin, or silodosin. Treatment began 1 day after PI and continued for 1 year. The primary efficacy variables were the changes in total International Prostate Symptom Score (IPSS) and postvoid residual urine (PVR). The secondary efficacy variables were changes in IPSS storage score and IPSS voiding score from baseline to set points during the study (1, 3, 6, and 12 months). Results: Two hundred twelve patients were evaluated in this study between June 2006 and February 2009: 71, 70, and 71 patients in the naftopidil, tamsulosin, and silodosin groups, respectively. With respect to the primary efficacy variables, the mean changes in the total IPSS at 1 month after PI in the naftopidil, tamsulosin, and silodosin groups were +10.3, +8.9, and +7.5, respectively. There were significantly greater decreases with silodosin than naftopidil at 1 month in the total IPSS. The mean changes in the PVR at 6 months were +14.6, +23.7, and +5.7 mL in the naftopidil, tamsulosin, and silodosin groups, respectively; silodosin showed a significant improvement in the PVR at 6 months vs. tamsulosin. With respect to the secondary efficacy variables, the mean changes in the IPSS voiding score at 1 month in the naftopidil, tamsulosin, and silodosin groups were +6.5, +5.6, and +4.5, respectively; silodosin showed a significant improvement in the IPSS voiding score at 1 month vs. naftopidil. Conclusions: Silodosin has a greater impact on improving PI

  15. Potential role of ultrasound imaging in interstitial image based cervical cancer brachytherapy

    PubMed Central

    2014-01-01

    In 2012, more than 500,000 cases of cervical cancer were diagnosed worldwide. Over three quarters of these cases occur in less developed countries [1]. Advancements in image-guided brachytherapy are resulting in improved outcomes and reduced morbidity for women with this disease, but its worldwide adoption is hampered by lack of accessibility to advanced imaging techniques. Ultrasound is emerging as a potential option for tumor visualization, brachytherapy catheter placement, and treatment planning. While additional work is needed, ultrasound can potentially serve as the sole imaging modality for catheter insertion and planning. This paper will review our current knowledge on the use of ultrasound in interstitial brachytherapy treatment for cervical cancer. PMID:25097565

  16. Direct determination of the absorbed dose to water from 125I low dose-rate brachytherapy seeds using the new absorbed dose primary standard developed at ENEA-INMRI

    NASA Astrophysics Data System (ADS)

    Toni, M. P.; Pimpinella, M.; Pinto, M.; Quini, M.; Cappadozzi, G.; Silvestri, C.; Bottauscio, O.

    2012-10-01

    Low-intensity radioactive sources emitting low-energy photons are used in the clinic for low dose-rate brachytherapy treatments of tumours. The dosimetry of these sources is based on reference air kerma rate measurements. The absorbed dose rate to water at the reference depth d0 = 1 cm, \\dot {D}_{w,1\\,cm} , is then obtained by a conversion procedure with a large relative standard uncertainty of about 5%. This paper describes a primary standard developed at ENEA-INMRI to directly measure \\dot {D}_{w,1\\,cm} due to LDR sources. The standard is based on a large-angle and variable-volume ionization chamber, embedded in a graphite phantom and operating under ‘wall-less air chamber’ conditions. A set of correction and conversion factors, based on experiments and Monte Carlo simulations, are determined to obtain the value of Dw,1 cm from measurements of increment of ionization current with increasing chamber volume. The relative standard uncertainty on \\dot {D}_{w,1\\,cm} is 2.6%, which is appreciably lower than the current uncertainty. Characteristics of the standard, its associated uncertainty budget, and some experimental results are given for 125I BEBIG I25.S16.C brachytherapy seeds. Finally, results of the experimental determination of the dose-rate constant Λ1 cm, traceable to the Dw,1 cm and the low-energy air kerma ENEA-INMRI standards, are given. The relative standard uncertainty on Λ1 cm is 2.9%, appreciably lower than the typical uncertainty (4.8%) of the values available in the literature.

  17. Salvage high-dose-rate interstitial brachytherapy for locally recurrent rectal cancer*

    PubMed Central

    Pellizzon, Antônio Cássio Assis

    2016-01-01

    For tumors of the lower third of the rectum, the only safe surgical procedure is abdominal-perineal resection. High-dose-rate interstitial brachytherapy is a promising treatment for local recurrence of previously irradiated lower rectal cancer, due to the extremely high concentrated dose delivered to the tumor and the sparing of normal tissue, when compared with a course of external beam radiation therapy. PMID:27403021

  18. Remote afterloading for intracavitary and interstitial brachytherapy with californium-252

    NASA Astrophysics Data System (ADS)

    Tačev, Tačo; Grigorov, Grigor; Papírek, Tomáš; Kolařík, Vladimír.

    2004-01-01

    The authors present their design concept of remote afterloading for 252Cf brachytherapy with respect to characteristic peculiarities of 252Cf and the current worldwide development of remote afterloading devices. The afterloading device has been designed as a stationary radiator comprising three mutually interconnected units: (1) a control and drive unit, consisting of a control computer and a motor-driven Bowden system carrying the 252Cf source; (2) a source housed in a watertight, concrete vessel, which is stored in a strong room situated well beneath the patient's bed and (3) an afterloading application module installed in the irradiation room. As 252Cf is a nuclide with low specific activity, it was necessary to produce two independent devices for high dose rate intracavitary treatment and for low dose rate intestinal treatment. The sources may be moved arbitrarily during the treatment with a position accuracy of 0.5-1.0 mm within a distance of 520 cm from the source storage position in the strong room to the application position. The technical concept of the present automatic afterloading device for neutron brachytherapy represents one possible option of a range of conceivable design variants, which, while minimizing the technical and economic requirements, provides operating personnel with optimum protection and work safety, thus extending the applicability of high-LET radiation-based treatment methods in clinical practice.

  19. Dosimetry of the 198Au Source used in Interstitial Brachytherapy

    SciTech Connect

    Dauffy, L; Braby, L; Berner, B

    2004-05-18

    The American Association of Physicists in Medicine Task Group 43 report, AAPM TG-43, provides an analytical model and a dosimetry protocol for brachytherapy dose calculations, as well as documentation and results for some sealed sources. The radionuclide {sup 198}Au (T{sub 1/2} = 2.70 days, E{gamma} = 412 keV) has been used in the form of seeds for brachytherapy treatments including brain, eye, and prostate tumors. However, the TG-43 report has no data for {sup 198}Au seeds, and none have previously been obtained. For that reason, and because of the conversion of most treatment planning systems to TG-43 based methods, both Monte Carlo calculations (MCNP 4C) and thermoluminescent dosimeters (TLDs) are used in this work to determine these data. The geometric variation in dose is measured using an array of TLDs in a solid water phantom, and the seed activity is determined using both a well ion chamber and a High Purity Germanium detector (HPGe). The results for air kerma strength, S{sub k}, per unit apparent activity, are 2.06 (MCNP) and 2.09 (measured) U mCi{sup -1}. The former is identical to what was published in 1991 in the AAPM Task Group 32 report. The dose rate constant results, {Lambda}, are 1.12 (MCNP) and 1.10 (measured), cGy h{sup -1} U{sup -1}. The radial dose function, g(r), anisotropy function, F(r,{theta}), and anisotropy factor, {psi}{sub an}(r), are given. The anisotropy constant values are 0.973 (MCNP) and 0.994 (measured) and are consistent with both source geometry and the emitted photon energy.

  20. Dosimetry of the 198Au source used in interstitial brachytherapy.

    PubMed

    Dauffy, Lucile S; Braby, Leslie A; Berner, Barry M

    2005-06-01

    The American Association of Physicists in Medicine Task Group 43 reports, AAPM TG-43 and its update TG-43U1, provide an analytical model and a dosimetry protocol for brachytherapy dose calculations, as well as documentation and results for some sealed sources. The radionuclide 198Au (T(1/2)=2.70 days, Egamma=412 keV) has been used in the form of seeds for brachytherapy treatments including brain, eye, and prostate tumors. However, TG-43 reports have no data for 198Au seeds, and none have previously been obtained. For that reason, and because of the conversion of most treatment planning systems to TG-43 based methods, both Monte Carlo calculations (MCNP 4C2) and thermoluminescent dosimeters (TLDs) are used in this work to determine these data. The geometric variation in dose is measured using an array of TLDs in a solid water phantom, and the seed activity is determined using a high purity germanium detector (HPGe) and a well ionization chamber. The results for air kerma strength, Sk, per unit apparent activity, are 2.063 (MCNP) and 2.089 (measured) U mCi(-1), values close to those published in 1991 in the AAPM Task Group 32 report. The dose rate constant, lambda, is found equal to 1.115 (MCNP) and 1.095 (measured) cGy h(-1) U(-1). The radial dose function, g(r), anisotropy function, F(r, theta), and anisotropy factor, phi(an)(r), are also given. PMID:16013717

  1. Dose-reducing effect of Lipowitz metal-embedded spacers in interstitial brachytherapy for carcinoma of the mobile tongue.

    PubMed

    Fujita, M; Hirokawa, Y; Tamamoto, M; Kashiwado, K; Akagi, Y; Kashimoto, K; Wada, T

    1994-06-01

    Dose-reducing effects of spacers with and without a Lipowitz metal plate for the purpose of decreasing osteoradionecrosis after interstitial brachytherapy for tongue cancers were examined experimentally and clinically. The thicker the sample or spacer and the thicker the metal plate, the greater was the dose reduction achieved. A more marked dose reduction was achieved with iridium than with radium because of lower gamma ray energy of iridium. Iridium has been used widely as a radioactive source for interstitial brachytherapy. It was concluded therefore that a metal plate should be used as a shield into the spacer in interstitial brachytherapy both to reduce the radiation dose to surrounding normal tissues and to help prevent osteoradionecrosis. PMID:8065721

  2. Predictors of Toxicity After Image-guided High-dose-rate Interstitial Brachytherapy for Gynecologic Cancer

    SciTech Connect

    Lee, Larissa J.; Viswanathan, Akila N.

    2012-12-01

    Purpose: To identify predictors of grade 3-4 complications and grade 2-4 rectal toxicity after three-dimensional image-guided high-dose-rate (HDR) interstitial brachytherapy for gynecologic cancer. Methods and Materials: Records were reviewed for 51 women (22 with primary disease and 29 with recurrence) treated with HDR interstitial brachytherapy. A single interstitial insertion was performed with image guidance by computed tomography (n = 43) or magnetic resonance imaging (n = 8). The median delivered dose in equivalent 2-Gy fractions was 72.0 Gy (45 Gy for external-beam radiation therapy and 24 Gy for brachytherapy). Toxicity was reported according to the Common Toxicity Criteria for Adverse Events. Actuarial toxicity estimates were calculated by the Kaplan-Meier method. Results: At diagnosis, the median patient age was 62 years and the median tumor size was 3.8 cm. The median D90 and V100 were 71.4 Gy and 89.5%; the median D2cc for the bladder, rectum, and sigmoid were 64.6 Gy, 61.0 Gy, and 52.7 Gy, respectively. The actuarial rates of all grade 3-4 complications at 2 years were 20% gastrointestinal, 9% vaginal, 6% skin, 3% musculoskeletal, and 2% lymphatic. There were no grade 3-4 genitourinary complications and no grade 5 toxicities. Grade 2-4 rectal toxicity was observed in 10 patients, and grade 3-4 complications in 4; all cases were proctitis with the exception of 1 rectal fistula. D2cc for rectum was higher for patients with grade 2-4 (68 Gy vs 57 Gy for grade 0-1, P=.03) and grade 3-4 (73 Gy vs 58 Gy for grade 0-2, P=.02) rectal toxicity. The estimated dose that resulted in a 10% risk of grade 2-4 rectal toxicity was 61.8 Gy (95% confidence interval, 51.5-72.2 Gy). Discussion: Image-guided HDR interstitial brachytherapy results in acceptable toxicity for women with primary or recurrent gynecologic cancer. D2cc for the rectum is a reliable predictor of late rectal complications. Three-dimensional-based treatment planning should be performed to ensure

  3. Multi-species prostate implant treatment plans incorporating {sup 192}Ir and {sup 125}I using a Greedy Heuristic based 3D optimization algorithm

    SciTech Connect

    Chaswal, V.; Yoo, S.; Thomadsen, B. R.; Henderson, D. L.

    2007-02-15

    The goals of interstitial implant brachytherapy include delivery of the target dose in a uniform manner while sparing sensitive structures, and minimizing the number of needles and sources. We investigated the use of a multi-species source arrangement ({sup 192}Ir with {sup 125}I) for treatment in interstitial prostate brachytherapy. The algorithm utilizes an 'adjoint ratio', which provides a means of ranking source positions and is the criterion for the Greedy Heuristic optimization. Three cases were compared, each using 0.4 mCi {sup 125}I seeds: case I is the base case using {sup 125}I alone, case II uses 0.12 mCi {sup 192}Ir seeds mixed with {sup 125}I, and case III uses 0.25 mCi {sup 192}Ir mixed with {sup 125}I. Both multi-species cases result in lower exposure of the urethra and central prostate region. Compared with the base case, the exposure to the rectum and normal tissue increases by a significant amount for case III as compared with the increase in case II, signifying the effect of slower dose falloff rate of higher energy gammas of {sup 192}Ir in the tissue. The number of seeds and needles decreases in both multi-species cases, with case III requiring fewer seeds and needles than case II. Further, the effect of {sup 192}Ir on uniformity was investigated using the 0.12 mCi {sup 192}Ir seeds in multi-species implants. An increase in uniformity was observed with an increase in the number of 0.12 mCi {sup 192}Ir seeds implanted. The effects of prostate size on the evaluation parameters for multi-species implants were investigated using 0.12 mCi {sup 192}Ir and 0.4 mCi {sup 125}I, and an acceptable treatment plan with increased uniformity was obtained.

  4. Trans-bronchoscopy with implantation of 125I radioactive seeds in patients with pulmonary atelectasis induced by lung cancer

    PubMed Central

    LU, MINGJIAN; PU, DELI; ZHANG, WEIDONG; LIAO, JIANGRONG; ZHANG, TAO; YANG, GUANG; LIU, ZHENYIN; SINGH, SRISTI; GAO, FEI; ZHANG, FUJUN

    2015-01-01

    To evaluate the role of low-dose-rate interstitial brachytherapy using trans-bronchoscope 125I radioactive seeds implantation in patients with pulmonary atelectasis induced by lung cancer, in terms of feasibility, safety, quality of life (QOL), and survival time. Between April 2008 and June 2011, 15 patients from two medical institutions that had obstructive pulmonary atelectasis caused by inoperable lung cancer were assigned to receive 125I implantation endoluminal brachytherapy by bronchoscopy. Subsequent to the implantation of 125I seeds, the outcomes were measured in terms of procedure success rate, reopening of atelectasis, complications associated with the procedure, Karnofsky performance status (KPS) scores and survival time. The surgical procedure was successfully performed in all 15 patients. No procedure-associated mortality occurred and the complications were mild and considered acceptable. Irritable cough and temporary increase of hemoptysis occurred in 11 (73.3%) and 10 (66.7%) patients respectively, and were the most common complications. The pulmonary atelectasis reopening rate subsequent to the procedure was 86.7, 76.9, 80.0, 75.0 and 50.0% at 2, 6, 12, 18 and 24 months, respectively. The KPS score significantly improved following the implantation of 125I seeds and the duration of improvement ranged between 3 and 27 months. The median and mean survival times were 15.6 and 16 months, respectively. Actuarial survival rates at 6, 12 and 24 months after the procedure were 86.7, 66.7 and 13.3%, respectively. In patients with advanced lung cancer and those presenting with obstructive pulmonary atelectasis, treatment with intraluminal implantation of 125I seeds is a safe and effective therapy option with easy accessibility. PMID:26171002

  5. Interstitial high-dose-rate brachytherapy in locally advanced and recurrent vulvar cancer

    PubMed Central

    Białas, Brygida; Fijałkowski, Marek; Wojcieszek, Piotr; Szlag, Marta; Cholewka, Agnieszka; Ślęczka, Maciej; Kołosza, Zofia

    2016-01-01

    Purpose The aim of the study was to report our experience with high-dose-rate interstitial brachytherapy (HDR-ISBT) in locally advanced and recurrent vulvar cancer. Material and methods Between 2004 and 2014, fourteen women with locally advanced or recurrent vulvar cancer were treated using HDR-ISBT in our Centre. High-dose-rate interstitial brachytherapy was performed as a separate treatment or in combination with external beam radiotherapy (EBRT) (given prior to brachytherapy). Results Patients were divided into: group I (n = 6) with locally advanced tumors, stages III-IVA after an incisional biopsy only, and group II (n = 8) with recurrent vulvar cancer after previous radical surgery. In group I, median follow up was 12 months (range 7-18 months); 1-year overall survival (OS) was 83%. Transient arrest of cancer growth or tumor regression was noticed in all patients but 4/6 developed relapse. Median time to failure was 6.3 months (range 3-11 months). The 1-year progression-free survival (PFS) was 33%. In group II, median follow up was 28 months (range 13-90 months). The 1-year and 3-year OS was 100% and 80%, respectively. The arrest of cancer growth or tumor regression was achieved in all patients. In 4/8 patients neither clinical nor histological symptoms of relapse were observed but 4/8 women experienced relapse. Median time to failure was 31 months (range 13-76 months). The 1-year and 3-year PFS was 100% and 62.5%, respectively. Two patients (14.3%) in group II had severe late toxicity (G3). Conclusions High-dose-rate interstitial brachytherapy is a well-tolerated treatment option in selected patients with advanced or recurrent vulvar cancer. It is a safe and effective treatment modality for advanced and recurrent vulvar cancer, yielding good local control with acceptable late treatment related side effects. In our study, patients with recurrent vulvar cancer had better results in HDR-ISBT treatment, probably because of the smaller tumor volume. This

  6. Stereotactic interstitial brachytherapy of malignant astrocytomas with remarks on postimplantation computed tomographic appearance

    SciTech Connect

    Willis, B.K.; Heilbrun, M.P.; Sapozink, M.D.; McDonald, P.R.

    1988-09-01

    Seventeen patients were treated with stereotactically implanted high activity iodine-125 seeds, 12 patients for recurrent malignant astrocytomas (Protocol I) and 5 patients for newly diagnosed glioblastomas (Protocol II). Total radiation dosage to the recurrent tumors in Protocol I, including prior external beam irradiation, averaged 13,500 cGy. In the follow-up period of 6 to 50 months, the survival rate was 93% at 6 months, 60% at 12 months, 50% at 18 months, and 38% at 24 months after implantation. In Protocol II, brachytherapy was used as an interstitial radiation boost to the conventional treatment of newly diagnosed glioblastomas. External beam therapy and interstitial brachytherapy provided 11,000 cGy to these tumors. In the follow-up period of 15 to 27 months, there was a 100% survival at 12 months, 75% at 18 months, and 25% at 24 months after implantation. Eight of our 17 patients required reoperation for persistent or recurrent mass lesions at 6 to 15 months postimplantation; 7 were found to harbor masses of radionecrosis containing nests of anaplastic astrocytes; 1 had frank tumor recurrence. Median survival in this group of patients requiring reoperation was 18.7 months postimplantation. In a review of postimplantation computed tomographic scans, significant mass effect and crossover of hypodensity or enhancement into the corpus callosum or opposite hemisphere were found to have prognostic significance; persistent areas of contrast enhancement and excessive peritumoral hypodensity did not.

  7. Quality Assurance of Multifractionated Pelvic Interstitial Brachytherapy for Postoperative Recurrences of Cervical Cancers: A Prospective Study

    SciTech Connect

    Shukla, Pragya; Chopra, Supriya; Engineer, Reena; Mahantshetty, Umesh; Paul, Siji Nojin; Phurailatpam, Reena; SV, Jamema; Shrivastava, Shyam K.

    2012-03-15

    Purpose: To evaluate three-dimensional needle displacements during multifractionated interstitial brachytherapy (BT) for cervical cancers. Methods and Materials: Patients scheduled to undergo pelvic interstitial BT for postoperative and or postradiation vault recurrences were included from November 2009 to December 2010. All procedures were performed under spinal anesthesia. Postprocedure BT planning CT scans were obtained with patients in supine position with arms on the chest (interslice thickness of 3 mm). Thereafter, verification CT was repeated at every alternate fraction. Needle displacements were measured in reference to a relocatable bony point. The mean cranial, caudal, anteroposterior, and mediolateral displacements were recorded. Statistical significance of mean interfraction displacements was evaluated with Wilcoxon Test. Results: Twenty patients were included. Seventeen received boost BT (20 Gy/5 fractions/3 days) after external radiation, three received radical BT alone (36 Gy/9 fractions/5-8 days). An average of three scans (range, 2-3) were available per patient, and 357 needle displacements were analyzed. For the entire study cohort, the average of mean needle displacement was 2.5 mm (range, 0-7.4), 17.4 mm (range, 0-27.9), 1.7 mm (range, 0-6.7), 2.1 mm (range, 0-9.5), 1.7 mm (range, 0-9.3), and 0.6 mm (range, 0-7.8) in cranial, caudal, anterior, posterior, right, and left directions, respectively. The mean displacement in the caudal direction was higher between Days 1 and 2 than that between Days 2 and 3 (13.4 mm vs. 3.8 mm; p = 0.01). The average caudal displacements were no different between reirradiation and boost cohort (15.2 vs. 17.8 mm). Conclusions: Clinically significant caudal displacements occur during multifractionated pelvic brachytherapy. Optimal margins need to be incorporated while preplanning brachytherapy to account for interfraction displacements.

  8. Outpatient combined intracavitary and interstitial cervical brachytherapy: barriers and solutions to implementation of a successful programme – a single institutional experience

    PubMed Central

    Tan, Poh Wee; Koh, Vicky Y.

    2015-01-01

    Involvement of parametrial disease in locally advanced cervical patients poses a challenge for women undergoing brachytherapy. Current use of the Fletcher suit applicator may not adequately cover the high risk clinical target volume (HR CTV), especially in the parametrial region due to the physical qualities of brachytherapy from the inverse square law and the need to respect organs at risk (OAR) constraints, and leads to lower local control rates. Combined intracavitary and interstitial brachytherapy with the use of 1 or 2 interstitial needles allows adequate coverage of the HR CTV and the clinical evidence have demonstrated a correlation with better clinical results. This procedure is often resource intensive, requiring inpatient stay and magnetic resonance imaging (MRI) planning. In departments where such resources are limited, there is a poor uptake of interstitial brachytherapy. This article discusses the technique of combined intracavitary and interstitial brachytherapy in an outpatient setting, and explores the issues and barriers for implementation and suggestions to overcome such barriers. PMID:26207117

  9. Long-Term Outcome for Clinically Localized Prostate Cancer Treated With Permanent Interstitial Brachytherapy

    SciTech Connect

    Taira, Al V.; Merrick, Gregory S.; Butler, Wayne M.; Galbreath, Robert W.; Lief, Jonathan; Adamovich, Edward; Wallner, Kent E.

    2011-04-01

    Purpose: To present the largest series of prostate cancer brachytherapy patients treated with modern brachytherapy techniques and postimplant day 0 dosimetric evaluation. Methods and Materials: Between April 1995 and July 2006, 1,656 consecutive patients were treated with permanent interstitial brachytherapy. Risk group stratification was carried out according to the Mt. Sinai guidelines. Median follow-up was 7.0 years. The median day 0 minimum dose covering at least 90% of the target volume was 118.8% of the prescription dose. Cause of death was determined for each deceased patient. Multiple clinical, treatment, and dosimetric parameters were evaluated for impact on the evaluated survival parameters. Results: At 12 years, biochemical progression-free survival (bPFS), cause-specific survival (CSS), and overall survival (OS) for the entire cohort was 95.6%, 98.2%, and 72.6%, respectively. For low-, intermediate-, and high-risk patients, bPFS was 98.6%, 96.5%, and 90.5%; CSS was 99.8%, 99.3%, and 95.2%; and OS was 77.5%, 71.1%, and 69.2%, respectively. For biochemically controlled patients, the median posttreatment prostate-specific antigen (PSA) concentration was 0.02 ng/ml. bPFS was most closely related to percent positive biopsy specimens and risk group, while Gleason score was the strongest predictor of CSS. OS was best predicted by patient age, hypertension, diabetes, and tobacco use. At 12 years, biochemical failure and cause-specific mortality were 1.8% and 0.2%, 5.1% and 2.1%, and 10.4% and 7.1% for Gleason scores 5 to 6 and 7 and {>=}8, respectively. Conclusions: Excellent long-term outcomes are achievable with high-quality brachytherapy for low-, intermediate-, and high-risk patients. These results compare favorably to alternative treatment modalities including radical prostatectomy.

  10. Dosimetric Consequences of Interobserver Variability in Delineating the Organs at Risk in Gynecologic Interstitial Brachytherapy

    SciTech Connect

    Damato, Antonio L.; Bair, Ryan J.; Cormack, Robert A.; Kovacs, Arpad; Lee, Larissa J.; Lewis, John H.; Viswanathan, Akila N.

    2014-07-01

    Purpose: To investigate the dosimetric variability associated with interobserver organ-at-risk delineation differences on computed tomography in patients undergoing gynecologic interstitial brachytherapy. Methods and Materials: The rectum, bladder, and sigmoid of 14 patients treated with gynecologic interstitial brachytherapy were retrospectively contoured by 13 physicians. Geometric variability was calculated using κ statistics, conformity index (CI{sub gen}), and coefficient of variation (CV) of volumes contoured across physicians. Dosimetric variability of the single-fraction D{sub 0.1cc} and D{sub 2cc} was assessed through CV across physicians, and the standard deviation of the total EQD2 (equivalent dose in 2 Gy per fraction) brachytherapy dose (SD{sup TOT}) was calculated. Results: The population mean ± 1 standard deviation of κ, CI{sub gen}, and volume CV were, respectively: 0.77 ± 0.06, 0.70 ± 0.08, and 20% ± 6% for bladder; 0.74 ± 06, 0.67 ± 0.08, and 20% ± 5% for rectum; and 0.33 ± 0.20, 0.26 ± 0.17, and 82% ± 42% for sigmoid. Dosimetric variability was as follows: for bladder, CV = 31% ± 19% (SD{sup TOT} = 72 ± 64 Gy) for D{sub 0.1cc} and CV = 16% ± 10% (SD{sup TOT} = 9 ± 6 Gy) for D{sub 2cc}; for rectum, CV = 11% ± 5% (SD{sup TOT} = 16 ± 17 Gy) for D{sub 0.1cc} and CV = 7% ± 2% (SD{sup TOT} = 4 ± 3 Gy) for D{sub 2cc}; for sigmoid, CV = 39% ± 28% (SD{sup TOT} = 12 ± 18 Gy) for D{sub 0.1cc} and CV = 34% ± 19% (SD{sup TOT} = 4 ± 4 Gy) for D{sub 2cc.} Conclusions: Delineation of bladder and rectum by 13 physicians demonstrated substantial geometric agreement and resulted in good dosimetric agreement for all dose-volume histogram parameters except bladder D{sub 0.1cc.} Small delineation differences in high-dose regions by the posterior bladder wall may explain these results. The delineation of sigmoid showed fair geometric agreement. The higher dosimetric variability for sigmoid compared with rectum and bladder did not correlate with

  11. Metallofullerene-Nanoplatform-Delivered Interstitial Brachytherapy Improved Survival in a Murine Model of Glioblastoma Multiforme

    PubMed Central

    Wilson, John D.; Broaddus, William C.; Dorn, Harry C.; Fatouros, Panos P.; Chalfant, Charles E.; Shultz, Michael D.

    2012-01-01

    Fullerenes are used across scientific disciplines because of their diverse properties gained by altering encapsulated or surface bound components. In this study, the recently developed theranostic agent based on a radiolabeled functionalized metallofullerene (177Lu-DOTA-f-Gd3N@C80) was synthesized with high radiochemical yield and purity. The efficacy of this agent was demonstrated in two orthotopic xenograft brain tumor models of glioblastoma multiforme (GBM). A dose-dependent improvement in survival was also shown. The in vivo stability of the agent was verified through dual label measurements of biological elimination from the tumor. Overall, these results provide evidence that nanomaterial platforms can be used to deliver effective interstitial brachytherapy. PMID:22881865

  12. Neuro-oncology update: radiation safety and nursing care during interstitial brachytherapy

    SciTech Connect

    Randall, T.M.; Drake, D.K.; Sewchand, W.

    1987-12-01

    Radiation control and safety are major considerations for nursing personnel during the care of patients receiving brachytherapy. Since the theory and practice of radiation applications are not part of the routine curriculum of nursing programs, the education of nurses and other health care professionals in radiation safety procedures is important. Regulatory agencies recommend that an annual safety course be given to all persons frequenting, using, or associated with patients containing radioactive materials. This article presents pertinent aspects of the principles and procedures of radiation safety, the role of personnel dose-monitoring devices, and the value of additional radiation control features, such as a lead cubicle, during interstitial brain implants. One institution's protocol and procedures for the care of high-intensity iridium-192 brain implants are discussed. Preoperative teaching guidelines and nursing interventions included in the protocol focus on radiation control principles.

  13. Permanent Iodine-125 Interstitial Planar Seed Brachytherapy for Close or Positive Margins for Thoracic Malignancies

    SciTech Connect

    Mutyala, Subhakar; Stewart, Alexandra; Khan, Atif J.; Cormack, Robert A.; O'Farrell, Desmond; Sugarbaker, David; Devlin, Phillip M.

    2010-03-15

    Purpose: To assess toxicity and outcome following permanent iodine-125 seed implant as an adjunct to surgical resection in cases of advanced thoracic malignancy. Methods and Materials: An institutional review board-approved retrospective review was performed. Fifty-nine patients were identified as having undergone thoracic brachytherapy seed implantation between September 1999 and December 2006. Data for patient demographics, tumor details, and morbidity and mortality were recorded. Results: Fifty-nine patients received 64 implants. At a median follow-up of 17 months, 1-year and 2-year Kaplan-Meier rates of estimated overall survival were 94.1% and 82.0%, respectively. The 1-year and 2-year local control rates were 80.1% and 67.4%, respectively. The median time to develop local recurrence was 11 months. Grades 3 and 4 toxicity rates were 12% at 1 year. Conclusions: This review shows relatively low toxicity for interstitial planar seed implantation after thoracic surgical resection. The high local control results suggest that an incomplete oncologic surgery plus a brachytherapy implant for treating advanced thoracic malignancy merit further investigation.

  14. Treatment results of stereotactic interstitial brachytherapy for primary and metastatic brain tumors

    SciTech Connect

    Lucas, G.L.; Luxton, G.; Cohen, D.; Petrovich, Z.; Langholz, B.; Apuzzo, M.L.; Sapozink, M.D. )

    1991-08-01

    A total of 41 stereotactic interstitial brain implants in 39 patients were performed for recurrence after teletherapy (recurrence implant), or as part of initial treatment in conjunction with teletherapy (primary implant). Implanted tumors consisted of malignant gliomas (33), other primary brain tumors (3), and single metastatic lesions (3). All patients were temporarily implanted with Ir-192 using a coaxial catheter afterloading system; two patients were implanted twice. Survival post-implant for glioblastoma multiforme (GBM), 13 patients, was 10 months whether implanted primarily or for recurrence. Mean time to recurrence, measured from initiation of teletherapy to implantation, was 10 months. Twenty patients with anaplastic astrocytoma (AA) had a median survival post-implant of 23 months for primary implants (7 patients) and 11 months for recurrence implants (13 patients). Mean time to recurrence, measured from initiation of teletherapy to implantation, was 19 months. Three patients (9%) of the evaluable group required reoperation for symptomatic mass effect, all with initial diagnosis of AA. Survival for this subgroup was 14, 22, and 32 months post-implantation. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically feasible with negligible acute morbidity and mortality, and appeared to offer limited prolongation of control for a subset of patients with recurrent malignant gliomas. The role of this modality in primary treatment for malignant gliomas needs to be further defined by prospectively randomized trials.

  15. Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

    SciTech Connect

    Wang, Wei; Pan, Li; Tokuda, Junichi; Schmidt, Ehud J.; Seethamraju, Ravi T.; Dumoulin, Charles L.

    2015-12-15

    Purpose: In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. Methods: The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter’s trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High

  16. Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

    PubMed Central

    Wang, Wei; Viswanathan, Akila N.; Damato, Antonio L.; Chen, Yue; Tse, Zion; Pan, Li; Tokuda, Junichi; Seethamraju, Ravi T.; Dumoulin, Charles L.; Schmidt, Ehud J.; Cormack, Robert A.

    2015-01-01

    Purpose: In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. Methods: The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter’s trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High

  17. Predictors of severe gastrointestinal toxicity after external beam radiotherapy and interstitial brachytherapy for advanced or recurrent gynecologic malignancies

    SciTech Connect

    Kasibhatla, Mohit . E-mail: Mohit.S.Kasibhatla@Hitchcock.org; Clough, Robert W. B.A.; Montana, Gustavo S.; Oleson, James R.; Light, Kim C.; Steffey, Beverley A.; Jones, Ellen L.

    2006-06-01

    Purpose: The aim of this retrospective review of patients with gynecologic malignancies treated with external beam radiotherapy (EBRT) and interstitial brachytherapy was to determine the rate of Grade {>=}2 rectovaginal fistula and Grade {>=}4 small bowel obstruction as defined by the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3.0. Methods and Materials: Thirty-six patients with primary and recurrent gynecologic cancers were treated with EBRT and interstitial brachytherapy. Median doses to tumor, bladder, and rectum were 75 Gy, 61 Gy, and 61 Gy, respectively. A univariate analysis was performed to identify variables that correlated with toxicity. Results: At median follow-up of 19 months, the 3-year risk of small bowel obstruction was 6%. Those patients with prior abdomino-pelvic surgery who received EBRT with antero-posterior fields had higher rates of obstruction than patients without prior abdomino-pelvic surgery or those who received EBRT with four fields (50% vs. 0%, p < 0.0001). The 3-year risk of rectovaginal fistula was 18% and was significantly higher in patients who received >76 Gy to the rectum compared with those who received {<=}76 Gy (100% vs. 7%, p = 0.009). Conclusions: Patients treated with EBRT and interstitial brachytherapy after abdomino-pelvic surgery should receive EBRT with four fields and the cumulative rectal dose should be {<=}76 Gy.

  18. High-dose-rate interstitial brachytherapy for female peri-urethral cancer

    PubMed Central

    Gandhi, Ajeet Kumar; Bhatla, Neerja; Kumar, Sunesh; Rath, Goura Kisor

    2016-01-01

    Purpose Peri-urethral cancer (PUC) in females is a rare malignancy. Surgery is not usually contemplated due to associated morbidity. Radiation therapy (RT) can be employed in the form of interstitial brachytherapy (IBT) alone for early lesions, and external beam radiation therapy (EBRT) with or without IBT for advanced lesions. We report our first experience in the literature to evaluate the role of high-dose-rate (HDR) IBT in female PUC. Material and methods Between 2008 and 2013, 10 female patients with PUC (5 primary and 5 recurrent) were treated with HDR-IBT with or without EBRT at our center. Size of the lesion ranged from 1.5 cm to 5.0 cm. A 2-3 plane free-hand implant was performed using plastic catheters. The prescribed dose of HDR-IBT was 42 Gy in 14 fractions for brachytherapy alone (5 patients), and 18-21 Gy for the boost along with EBRT (5 patients). Patients were followed up regularly for assessment of disease control and toxicity. Results At a median follow up of 25 months, six patients were disease free at their last follow up. Four patients developed recurrence: 2 at inguinal nodes, 1 at local site, and 1 at both local as well as inguinal nodes. Moist desquamation was the commonest acute toxicity observed in all 5 patients treated with IBT alone, which healed within 4 weeks’ time. Overall, grade II delayed complication rate was 30%. Conclusions Though small sample size, the results of our study have shown that HDR-IBT provides good loco-regional control with acceptable toxicity for female PUC. PMID:26985196

  19. Interstitial brachytherapy of periorificial skin carcinomas of the face: A retrospective study of 97 cases

    SciTech Connect

    Rio, Emmanuel . E-mail: e-rio@nantes.fnclcc.fr; Bardet, Etienne; Ferron, Christophe; Peuvrel, Patrick; Supiot, Stephane; Campion, Loic; Beauvillain De Montreuil, Claude; Mahe, Marc Andre; Dreno, Brigitte

    2005-11-01

    Purpose: To analyze outcomes after interstitial brachytherapy of facial periorificial skin carcinomas. Patients and Methods: We performed a retrospective analysis of 97 skin carcinomas (88 basal cell carcinomas, 9 squamous cell carcinomas) of the nose, periorbital areas, and ears from 40 previously untreated patients (Group 1) and 57 patients who had undergone surgery (Group 2). The average dose was 55 Gy (range, 50-65 Gy) in Group 1 and 52 Gy (range, 50-60 Gy) in Group 2 (mean implantation times: 79 and 74 hours, respectively). We calculated survival rates and assessed functional and cosmetic results de visu. Results: Median age was 71 years (range, 17-97 years). There were 29 T1, 8 T2, 1 T3, and 2 Tx tumors in Group 1. Tumors were <2 cm in Group 2. Local control was 92.5% in Group 1 and 88% in Group 2 (median follow-up, 55 months; range, 6-132 months). Five-year disease-free survival was better in Group 1 (91%; range, 75-97) than in Group 2 (80%; range, 62-90; p = 0.23). Of the 34 patients whose results were reassessed, 8 presented with pruritus or epiphora; 1 Group 2 patient had an impaired eyelid aperture. Cosmetic results were better in Group 1 than in Group 2 with, respectively, 72% (8/11) vs. 52% (12/23) good results and 28 (3/11) vs. 43% (10/23) fair results. Conclusions: Brachytherapy provided a high level of local control and good cosmetic results for facial periorificial skin carcinomas that pose problems of surgical reconstruction. Results were better for untreated tumors than for incompletely excised tumors or tumors recurring after surgery.

  20. Dosimetric perturbations of a lead shield for surface and interstitial high-dose-rate brachytherapy.

    PubMed

    Candela-Juan, Cristian; Granero, Domingo; Vijande, Javier; Ballester, Facundo; Perez-Calatayud, Jose; Rivard, Mark J

    2014-06-01

    In surface and interstitial high-dose-rate brachytherapy with either (60)Co, (192)Ir, or (169)Yb sources, some radiosensitive organs near the surface may be exposed to high absorbed doses. This may be reduced by covering the implants with a lead shield on the body surface, which results in dosimetric perturbations. Monte Carlo simulations in Geant4 were performed for the three radionuclides placed at a single dwell position. Four different shield thicknesses (0, 3, 6, and 10 mm) and three different source depths (0, 5, and 10 mm) in water were considered, with the lead shield placed at the phantom surface. Backscatter dose enhancement and transmission data were obtained for the lead shields. Results were corrected to account for a realistic clinical case with multiple dwell positions. The range of the high backscatter dose enhancement in water is 3 mm for (60)Co and 1 mm for both (192)Ir and (169)Yb. Transmission data for (60)Co and (192)Ir are smaller than those reported by Papagiannis et al (2008 Med. Phys. 35 4898-4906) for brachytherapy facility shielding; for (169)Yb, the difference is negligible. In conclusion, the backscatter overdose produced by the lead shield can be avoided by just adding a few millimetres of bolus. Transmission data provided in this work as a function of lead thickness can be used to estimate healthy organ equivalent dose saving. Use of a lead shield is justified. PMID:24705066

  1. Performance and suitability assessment of a real-time 3D electromagnetic needle tracking system for interstitial brachytherapy

    PubMed Central

    Boutaleb, Samir; Fillion, Olivier; Bonillas, Antonio; Hautvast, Gilion; Binnekamp, Dirk; Beaulieu, Luc

    2015-01-01

    Purpose Accurate insertion and overall needle positioning are key requirements for effective brachytherapy treatments. This work aims at demonstrating the accuracy performance and the suitability of the Aurora® V1 Planar Field Generator (PFG) electromagnetic tracking system (EMTS) for real-time treatment assistance in interstitial brachytherapy procedures. Material and methods The system's performance was characterized in two distinct studies. First, in an environment free of EM disturbance, the boundaries of the detection volume of the EMTS were characterized and a tracking error analysis was performed. Secondly, a distortion analysis was conducted as a means of assessing the tracking accuracy performance of the system in the presence of potential EM disturbance generated by the proximity of standard brachytherapy components. Results The tracking accuracy experiments showed that positional errors were typically 2 ± 1 mm in a zone restricted to the first 30 cm of the detection volume. However, at the edges of the detection volume, sensor position errors of up to 16 mm were recorded. On the other hand, orientation errors remained low at ± 2° for most of the measurements. The EM distortion analysis showed that the presence of typical brachytherapy components in vicinity of the EMTS had little influence on tracking accuracy. Position errors of less than 1 mm were recorded with all components except with a metallic arm support, which induced a mean absolute error of approximately 1.4 mm when located 10 cm away from the needle sensor. Conclusions The Aurora® V1 PFG EMTS possesses a great potential for real-time treatment assistance in general interstitial brachytherapy. In view of our experimental results, we however recommend that the needle axis remains as parallel as possible to the generator surface during treatment and that the tracking zone be restricted to the first 30 cm from the generator surface. PMID:26622231

  2. The Vienna applicator for combined intracavitary and interstitial brachytherapy of cervical cancer: Clinical feasibility and preliminary results

    SciTech Connect

    Dimopoulos, Johannes . E-mail: johannes.dimopoulos@akhwien.at; Kirisits, Christian; Petric, Primoz; Georg, Petra; Lang, Stefan; Berger, Daniel; Poetter, Richard

    2006-09-01

    Purpose: The aims of this study were to investigate the clinical feasibility and to report on preliminary treatment outcomes of combined intracavitary/interstitial brachytherapy, using a novel applicator and magnetic resonance imaging (MRI)-based treatment planning in patients with locally advanced cervical cancer. Methods and Materials: A total of 22 cervical cancer patients with insufficient response and/or unfavorable topography after external-beam irradiation were included in this study. Parametrial extent of the disease in these patients was judged to exceed the coverage limit of intracavitary brachytherapy alone. A modified tandem/ring (T/R) applicator for guidance of parametrial needles (N) was used to perform high-dose-rate-brachytherapy with MRI-based treatment planning. Clinical feasibility and preliminary treatment outcomes were assessed. Results: A total of 44 interstitial needle implants were performed. The spatial relations between the T/R + N applicator, high-risk clinical target volume, and organs at risk were visible clearly in all cases. Accurate and reproducible needle placement could be achieved in the majority of cases. No severe adverse events were caused by the intervention. The mean follow-up period was 20 months (range, 5-35 months). No G3 to G4 early or persistent late side effects were observed. Complete remission was achieved in 21 patients (95%). One local recurrence was observed within the high-risk clinical target volume area during follow-up. Conclusions: Our preliminary clinical experience indicates that combined intracavitary and interstitial MRI-based brachytherapy in patients with significant residual disease after external-beam therapy extending up to the distal third of parametria is feasible and allows excellent local control and a low rate of morbidity.

  3. 125I Seed Permanent Implantation as a Palliative Treatment for Stage III and IV Hypopharyngeal Carcinoma

    PubMed Central

    Li, Lei; Yang, Jie; Li, Xiaojiang; Wang, Xiaoli; Ren, Yanxin; Fei, Jimin; Xi, Yan; Sun, Ruimei; Ma, Jing

    2016-01-01

    Objectives. The aim of this study was to investigate the feasibility and safety of percutaneous 125I seed permanent implantation for advanced hypopharyngeal carcinoma from toxicity, tumor response, and short-term outcome. Methods. 125I seeds implant procedures were performed under computed tomography for 34 patients with advanced hypopharyngeal carcinoma. We observed the local control rate, overall survival, and acute or late toxicity rate. Results. In the 34 patients (stage III, n=6; stage IV, n=28), the sites of origin were pyriform sinus (n=29) and postcricoid area (n=5). All patients also received one to four cycles of chemotherapy after seed implantation. The post-plan showed that the actuarial D90 of 125I seeds ranged from 90 to 158 Gy (median, 127 Gy). The mean follow-up was 12.3 months (range, 3.4 to 43.2 months). The local control was 2.1–31.0 months with a median of 17.7 months (95% confidence interval [CI], 13.4 to 22.0 months). The 1-, 2-, and 3-year local controls were 65.3%, 28.6%, and 9.5% respectively. Twelve patients (35%) died of local recurrence, fourteen patients (41%) died of distant metastases, and three patients (9%) died of recurrence and metastases at the same time. Five patients (15%) still survived to follow-up. At the time of analysis, the median survival time was 12.5 months (95% CI, 9.5 to 15.4 months). The 1-, 2-, and 3-year overall survival rates were 55.2%, 20.3%, and 10.9%, respectively. Five patients (15%) experienced grade 3 toxic events and nine patients (26%) have experienced grade 2 toxic events. Conclusion. This review shows relatively low toxicity for interstitial 125I seed implantation in the patients with advanced stage hypopharyngeal cancer. The high local control results suggest that 125I seed brachytherapy implant as a salvage or palliative treatment for advanced hypopharyngeal carcinoma merit further investigation. PMID:27440132

  4. Institutional experience using interstitial brachytherapy for the treatment of primary and recurrent pelvic malignancies

    PubMed Central

    Onderdonk, Benjamin; Cunningham, Mary; Daugherty, Emily; Du, Lingyun; Bunn, W. Douglas; Agarwal, Rinki; Hahn, Seung Shin

    2016-01-01

    Purpose The study assessed the outcomes of patients at a single institution with locally advanced primary and recurrent pelvic malignancies treated with interstitial high-dose-rate (HDR) or low-dose-rate (LDR) brachytherapy (BT), using a modified Syed-Neblett template. Material and methods Between 1996 and 2010, 60 patients with primary or recurrent pelvic malignancies were treated with interstitial BT. Thirty three patients had primary malignancies with 6.1% being stage I, 33.3% stage II, 45.5% stage III, and 15.2% stage IV; the remaining 27 patients were recurrent malignancies. Fifty four patients received external beam radiotherapy (EBRT) as part of their treatment course. The median EBRT, BT, and EBRT + BT doses were 45 Gy, 20 Gy, and 65 Gy, respectively. Thirty eight patients received concurrent chemotherapy with EBRT. Complete response (CR) was defined by absence of clinical and radiographic disease on first follow-up. Toxicity was graded as per Common Terminology Criteria for Adverse Events, version 4.0. Results The median follow-up was 37 months (4-234 months) and initial CR was achieved in 91%. For primary cancers at diagnosis, 5-year local control (LC), 5-year progression-free survival (PFS), 5-year overall survival (OS) were 65%, 64%, and 42% respectively. For recurrent cancers at diagnosis, 5-year LC, 5-year PFS, and 5-year OS were 80%, 51%, and 37%, respectively. There was a significant difference in both OS and PFS among different tumor sites (p < 0.05), with vaginal cancers having the best 5-year OS (55%) and PFS (84%). There was a total of 1 acute toxicity ≥ grade 3, 6 late grade 3 toxicities, and late grade 4 toxicity. Conclusions Our series suggests that interstitial BT using a modified Syed-Neblett template is a safe and effective treatment for primary or recurrent pelvic malignancies. This technique allowed effective LC and 97% of patients had preservation of both bladder and rectal function. PMID:27504125

  5. Image-guided high-dose-rate interstitial brachytherapy – a valuable salvage treatment approach for loco-regional recurrence of papillary thyroid cancer

    PubMed Central

    Wu, Ning; Zhao, Hongfu; Han, Dongmei; Zhao, Zhipeng; Ge, Yuxin

    2016-01-01

    Purpose To report the treatment effect of image-guided high-dose-rate (HDR) interstitial brachytherapy for refractory recurrence of papillary thyroid cancer (PTC). Case report This 66-year-old female presented with recurrence 5 years after thyroidectomy for PTC. Despite external irradiation and radioactive 131I, the lesion expanded as 3.7 × 3.0 × 2.3 cm3 and 2.0 × 1.5 × 1.5 cm3. The locoregional recurrent tumor was treated with image-guided HDR interstitial brachytherapy. The total dose of 30 Gy in 6 fractions were delivered on the whole recurrent tumor. Results Removal of the recurrent tumor was securely achieved by HDR interstitial brachytherapy guided with ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) scanning. The refractory tumor in the patients healed uneventfully after HDR interstitial brachytherapy without recurrence during the 14 months of follow-up. Conclusions The image-guided HDR interstitial brachytherapy may be a valuable salvage treatment approach for refractory recurrence of PTC. PMID:27257420

  6. Dosimetric characteristics and a standard for the (198)gold seed used in interstitial brachytherapy

    NASA Astrophysics Data System (ADS)

    Dauffy, Lucile S.

    Cancer of the prostate can be treated in different ways. One of them, brachytherapy, is an internal irradiation method consisting of the placement of radioactive sources, called seeds, into the tumor. This work deals with the dosimetry of the 198Au interstitial brachytherapy source. In order to facilitate its clinical use and to obtain the data to be employed in the latest treatment planning systems, new quantities and a potential calibration standard are studied. These quantities, based on dose rates, were recommended in 1995 by the American Association of Physicists in Medicine Task Group 43, AAPM TG-43, and have not previously been obtained for 198Au. They are measured in a solid water phantom using thermoluminescent detectors, and calculated using the Monte Carlo N-Particle code, MCNP, and simple analytic models. In the last part of this work, the "198Au equivalent" activity of 137Cs and 192Ir surrogate seeds is calculated since the National Institute of Standards and Technology, NIST, does not provide a standard for the short half-life 198Au source that would allow checking the activity of the seeds before use on patients. This calculation is done by simulating the response of the Sun Nuclear ionization chamber, model 1008, with MCNP 4C. The air kerma strength, Sk, per unit apparent activity is found equal to 2.0627 (MCNP) and 2.0889 U mCi-1 (measured). Sk per unit activity is 1.8050 U mCi-1 (MCNP). The dose rate constant per unit apparent activity, Λ/Aapp, is equal to 2.3099 (MCNP) and 2.2878 cGy h-1 mCi -1 (measured). This same quantity per unit air kerma strength is 1.1198 (MCNP) and 1.0952 cGy h-1 U-1 (measured). The values of the radial dose function, g(r), the anisotropy function, F(r,θ), the anisotropy factor, φan(r), and the anisotropy constant are also given. Finally, the "198Au equivalent" activity for the 192Ir surrogate seed is equal to 1.9549 times the real activity of the 192Ir seed, and that for the 137Cs surrogate seed is 1.4895 times its

  7. Transition from Paris dosimetry system to 3D image-guided planning in interstitial breast brachytherapy

    PubMed Central

    Wronczewska, Anna; Kabacińska, Renata; Makarewicz, Roman

    2015-01-01

    Purpose The purpose of this study is to evaluate our first experience with 3D image-guided breast brachytherapy and to compare dose distribution parameters between Paris dosimetry system (PDS) and image-based plans. Material and methods First 49 breast cancer patients treated with 3D high-dose-rate interstitial brachytherapy as a boost were selected for the study. Every patient underwent computed tomography, and the planning target volume (PTV) and organs at risk (OAR) were outlined. Two treatment plans were created for every patient. First, based on a Paris dosimetry system (PDS), and the second one, imaged-based plan with graphical optimization (OPT). The reference isodose in PDS implants was 85%, whereas in OPT plans the isodose was chosen to obtain proper target coverage. Dose and volume parameters (D90, D100, V90, V100), doses at OARs, total reference air kerma (TRAK), and quality assurance parameters: dose nonuniformity ratio (DNR), dose homogeneity index (DHI), and conformity index (COIN) were used for a comparison of both plans. Results The mean number of catheters was 7 but the mean for 20 first patients was 5 and almost 9 for the next 29 patients. The mean value of prescribed isodose for OPT plans was 73%. The mean D90 was 88.2% and 105.8%, the D100 was 59.8% and 75.7%, the VPTV90 was 88.6% and 98.1%, the VPTV100 was 79.9% and 98.9%, and the TRAK was 0.00375 Gym–1 and 0.00439 Gym–1 for the PDS and OPT plans, respectively. The mean DNR was 0.29 and 0.42, the DHI was 0.71 and 0.58, and the COIN was 0.68 and 0.76, respectively. Conclusions The target coverage in image-guided plans (OPT) was significantly higher than in PDS plans but the dose homogeneity was worse. Also, the value of TRAK increased because of change of prescribing isodose. The learning curve slightly affected our results. PMID:26816505

  8. High-dose-rate interstitial brachytherapy in early stage oral tongue cancer – 15 year experience from a tertiary care institute

    PubMed Central

    Bansal, Anshuma; Ghoshal, Sushmita; Oinam, Arun S; Sharma, Suresh Chander; Dhanireddy, Bhaswanth

    2016-01-01

    Purpose To determine outcomes of interstitial high-dose-rate brachytherapy (HDR-BT) in patients with early stage oral tongue cancer. Material and methods Ninety-two patients with stage I and II oral tongue cancer were treated with HDR-BT between 1999 and 2014: brachytherapy alone = 62 (67.4%), and combination of external beam radiotherapy (EBRT) and brachytherapy = 30 (32.6%). Median follow-up was 53.5 months. Patterns of failure, overall survival (OS), disease-free survival (DFS), local control rates (LCR), and nodal control rates (NCR) were determined. Results 5-year OS, DFS, LCR, and NCR were 73.2%, 58.2%, 64.2%, and 83.8%, respectively. In total, 43 patients (46.7%) failed treatment: isolated local failures = 28 (30.4%), isolated nodal failures = 8 (8.7%), both local and regional failures = 7 (7.6%). While in T1 stage, 5 year LCR were significantly higher in brachytherapy alone group compared to combined EBRT and brachytherapy group (81.7% vs. 62.5%, p = 0.04), the isolated nodal failure rates were not significantly different among the two groups. For T2 stage, NCR were higher in combined EBRT and brachytherapy group compared to brachytherapy alone (92.9% vs. 74.3%). Acute mucositis (grade ≥ 2) was seen more in brachytherapy alone group compared to the combined modality group (87% vs. 66%), and this correlated significantly with the higher biological equivalent dose (BED) in the brachytherapy alone group. Conclusions Our study recommends treating patients with brachytherapy alone in T1 stage, and demonstrates the need for addressing nodal region either by neck dissection or nodal irradiation in T2 stage patients. Also, the study highlights the need for dose escalation (from the doses used in the study) in both T1 and T2 stage tumors when using interstitial brachytherapy either as sole modality or as a boost. PMID:26985198

  9. A new template for MRI-based intracavitary/interstitial gynecologic brachytherapy: design and clinical implementation

    PubMed Central

    Sancho, Jose Richart; Palacin, Antonio Otal; Calatayud, Jose Perez; Ortega, Manuel Santos

    2015-01-01

    Purpose To describe the potential clinical use of a new brachytherapy applicator for gynecological tumors, with special attention to locally advanced cervical carcinoma. This device allows the combination of intracavitary radiotherapy and MRI-compatible transperineal interstitial needles. The design of this template addresses the disadvantages of currently commercially available templates: the inability of the intracavitary component to reach deep into the cervix (MUPIT), and the MRI-incompatibility of these templates (MUPIT and Syed), which necessitates use of CT imaging for the dosimetry. Material and methods The newly developed Benidorm Template applicator allows titanium needles in a template with straight and angled holes to provide different angles of divergence to be used with currently existing MRI-compatible intrauterine tubes. It can provide total coverage of the craniocaudal and lateral extension of the tumor (intrautherus, parametrial, and paravaginal). This method is mainly indicated in advanced cervical carcinoma with bulky parametrial invasion (medial or distal), with bulky primary disease that responds poorly to external beam radiotherapy extensive paravaginal involvement (tumor thickness greater than 0.5 cm) extending to the middle or lower third of the vagina, or for disease that has invaded the bladder or rectum (stage IVA). Results Between April 2013 until December 2014, we treated 15 patients with locally advanced cervical carcinoma employing the Benidorm Template. The median dose at D90 for the CTV was 79.8 Gy (71.5-89.9 Gy), at D2cc for the bladder it was 77.6 Gy (69.8-90.8 Gy), and at D2cc for the rectum it was 71.9 Gy (58.3-83.7 Gy). Values expressed in EQD2, assuming α/β of 10 for CTV and 3 for OAR. Conclusions This new applicator allows the use of MRI-based dosimetry, thus providing the advantages of MRI volume definition. As such, it facilitates determination of complete intracavitary and interstitial CTV coverage and the sparing of

  10. Quality of Life of Oral Cancer Patients After Low-Dose-Rate Interstitial Brachytherapy

    SciTech Connect

    Yoshimura, Ryo-ichi Shibuya, Hitoshi; Miura, Masahiko; Watanabe, Hiroshi; Ayukawa, Fumio; Hayashi, Keiji; Toda, Kazuma

    2009-03-01

    Purpose: To assess the quality of life (QOL) of oral cancer patients treated with low-dose-rate interstitial brachytherapy (LDR-BT) alone. Methods and Materials: Between June 2005 and July 2006, a total of 56 patients with oral cancer were enrolled in this prospective study. QOL was assessed by means of the core questionnaire and head and neck questionnaire module of the European Organization for Research and Treatment of Cancer (EORTC Quality of Life Questionnaire-Core 30 [QLQ-C30] and QLQ Head and Neck 35 [H and N35]). The questionnaires were distributed to the patients before the start of treatment and 3 months, 6 months, and 12 months after the start of LDR-BT. Results: It was possible to analyze the results for 20 of the initial 56 patients because they did not experience metastasis or recurrence during this study. No functions or symptoms asked about in the QLQ-C30 deteriorated during the first year. The emotional function score steadily and significantly increased. No symptoms in the QLQ-H and N35 significantly deteriorated. The scores for pain, trouble with social eating, and weight loss on the QLQ-H and N35 steadily and significantly decreased. Age, gender, and LDR-BT source had no effect on the change in QOL during the first year, but T-stage significantly affected the change in global health status, tumor site affected the changes in swallowing, sensory problems, sticky saliva, and complications affected the changes in pain, swallowing, and mouth opening. Conclusions: QOL of oral cancer patients treated with LDR-BT is high. However, tumor stage, tumor site, and complications affected the changes in a few functions and symptoms during the first year.

  11. Prospective evaluation of quality of life after interstitial brachytherapy for localized prostate cancer

    SciTech Connect

    Caffo, Orazio . E-mail: orazio.caffo@apss.tn.it; Fellin, Gianni; Bolner, Andrea; Coccarelli, Franco; Divan, Claudio; Frisinghelli, Michela; Mussari, Salvatore; Ziglio, Franco; Malossini, Gianni; Tomio, Luigi; Galligioni, Enzo

    2006-09-01

    Purpose: Permanent interstitial brachytherapy (IB) has become an increasingly appealing therapeutic option for localized prostate cancer (LPC) among physicians and patients because it involves short hospitalization and treatment and its postulated low degree of toxicity may reduce its impact on the patients' quality of life (QoL). The aim of this prospective study was to assess the impact of IB on the QoL of patients with LPC. Methods and Materials: A validated self-completed questionnaire was administered to the patients before and after IB and then at yearly intervals. The items allowed the identification of seven subscales exploring physical well-being (PHY), physical autonomy (POW), psychological well-being (PSY), relational life (REL), urinary function (URI), rectal function (REC), and sexual function (SEX). Results: The assessment of the QoL of 147 patients treated between May 2000 and February 2005 revealed no relevant differences in the PHY scale scores 1 month after IB or later, and the same was true of the POW, PSY, and REL scales. Urinary function significantly worsened after IB and returned to pretreatment levels only after 3 years; the impact of the treatment on the URI scale was greater in the patients with good baseline urinary function than in those presenting more urinary symptoms before IB. Rectal and sexual functions were significantly worse only at the post-IB evaluation. Conclusions: The results of the present study confirm that the impact of IB on the patients' QoL is low despite its transient negative effects on some function, and extend existing knowledge concerning QoL after IB.

  12. [Brachytherapy].

    PubMed

    Itami, Jun

    2014-12-01

    Brachytherapy do require a minimal expansion of CTV to obtain PTV and it is called as ultimate high precision radiation therapy. In high-dose rate brachytherapy, applicators will be placed around or into the tumor and CT or MRI will be performed with the applicators in situ. With such image-guided brachytherapy (IGBT) 3-dimensional treatment planning becomes possible and DVH of the tumor and organs at risk can be obtained. It is now even possible to make forward planning satisfying dose constraints. Traditional subjective evaluation of brachytherapy can be improved to the objective one by IGBT. Brachytherapy of the prostate cancer, cervical cancer, and breast cancer with IGBT technique was described. PMID:25596048

  13. Endoscope-Guided Interstitial Intensity-Modulated Brachytherapy and Intracavitary Brachytherapy as Boost Radiation for Primary Early T Stage Nasopharyngeal Carcinoma

    PubMed Central

    Qi, Zhen-Yu; Li, Ai-Ju; Ye, Wei-Jun; Hua, Yi-Jun; Zhu, Yu-Liang; Zou, Xiong; Guo, Ling; Mai, Hai-Qiang; Guo, Xiang; Hong, Ming-Huang; Chen, Ming-Yuan

    2014-01-01

    Background Intracavitary brachytherapy (ICBT) is usually applied as boost radiotherapy for superficial residual of nasopharyngeal carcinoma (NPC) after primary extern-beam radiptherapy (ERT). Here, we evaluated the outcome of endoscope-guided interstitial intensity-modulated brachytherapy (IMBT) boost radiation for deep-seated residual NPC. Methodology/Principal Findings Two hundred and thirteen patients with residual NPC who were salvaged with brachytherapy boost radiation during 2005–2009 were analyzed retrospectively. Among these patients, 171 patients had superficial residual NPC (≤1 cm below the nasopharyngeal epithelium) were treated with ICBT boost radiation, and interstitial IMBT boost radiation was delivered to 42 patients with deep-seated residual NPC (>1 cm below the nasopharyngeal epithelium). We found that IMBT boost subgroup had a higher ratio of T2b (81.0% VS 34.5%, P<0.001) and stage II (90.5% VS 61.4%, P = 0.001) than that of ICBT boost subgroup. The dosage of external-beam radiotherapy in the nasopharyngeal (63.0±3.8 VS 62.6±4.3 Gray (Gy), P = 0.67) and regional lymph nodes (55.8±5.0 VS 57.5±5.7 Gy, P = 0.11) was comparable in both groups. For brachytherapy, IMBT subgroup had a lower boost radiation dosage than ICBT subgroup (11.0±2.9 VS 14.8±3.2 Gy, P<0.01). Though the IMBT group had deeper residual tumors and received lower boost radiation dosages, both subgroups had the similar 5-year actuarial overall survival rate (IMBT VS ICBT group: 96.8% VS 93.6%, P = 0.87), progression-free survival rate (92.4% VS 86.5%, P = 0.41) and distant metastasis-free survival rate (94.9% VS 92.7%, P = 0.64). Moreover, IMBT boost radiation subgroup had a similar local (97.4% VS 94.4%, P = 0.57) and regional (95.0% VS 97.2%, P = 0.34) control to ICBT subgroup. The acute and late toxicities rates were comparable between the both subgroups. Conclusions/Significance IMBT boost radiation may be a promising therapeutic selection

  14. Helical Tomotherapy Delivery of an IMRT Boost in Lieu of Interstitial Brachytherapy in the Setting of Gynecologic Malignancy: Feasibility and Dosimetric Comparison

    SciTech Connect

    Gielda, Benjamin T.; Shah, Anand P.; Marsh, James C.; Smart, Joseph P.; Bernard, Damian; Rotmensch, Jacob; Griem, Katherine L.

    2011-07-01

    Interstitial brachytherapy is an important means by which to improve local control in gynecologic malignancy when intracavitary brachytherapy is untenable. Patients unable to receive brachytherapy have traditionally received conventional external beam radiation alone with modest results. We investigated the ability of Tomotherapy (Tomotherapy Inc., Madison, WI) to replace interstitial brachytherapy. Six patients were selected. The planning CT of each patient was contoured with the planning target volume (PTV), bladder, rectum, femoral heads, and bowel. Identical contour sets were exported to Tomotherapy and Nucletron PLATO (Nucletron B.V., Veenendaal, The Netherlands). With Tomotherapy, the PTV was prescribed 31 Gy in 5 fractions to 90% of the volume. With PLATO, 600 cGy x 5 fractions was prescribed to the surface of the PTV. Dose delivered was normalized to 2 Gy fractions (EQD2) and added to a hypothetical homogenous 45-Gy pelvic dose. Tomotherapy achieved a D90 of 87 Gy EQD2 versus 86 Gy with brachytherapy. PTV dose was more homogeneous with tomotherapy. The dose to the most at-risk 2 mL of bladder and rectum with Tomotherapy was of 78 and 71 Gy EQD2 versus 81 and 75 Gy with brachytherapy. Tomotherapy delivered more dose to the femoral heads (mean 1.23 Gy per fraction) and bowel. Tomotherapy was capable of replicating the peripheral dose achieved with brachytherapy, without the PTV hotspots inherent to interstitial brachytherapy. Similar maximum doses to bowel and bladder were achieved with both methods. Excessive small bowel and femoral head toxicity may result if previous pelvic irradiation is not planned accordingly. Significant challenges related to interfraction and intrafraction motion must be overcome if treatment of this nature is to be contemplated.

  15. Brachytherapy

    MedlinePlus

    ... smaller area in less time than conventional external beam radiation therapy. Brachytherapy is used to treat cancers ... to kill cancer cells and shrink tumors. External beam radiation therapy (EBRT) involves high-energy x-ray ...

  16. Development of 3D ultrasound needle guidance for high-dose-rate interstitial brachytherapy of gynaecological cancers

    NASA Astrophysics Data System (ADS)

    Rodgers, J.; Tessier, D.; D'Souza, D.; Leung, E.; Hajdok, G.; Fenster, A.

    2016-04-01

    High-dose-rate (HDR) interstitial brachytherapy is often included in standard-of-care for gynaecological cancers. Needles are currently inserted through a perineal template without any standard real-time imaging modality to assist needle guidance, causing physicians to rely on pre-operative imaging, clinical examination, and experience. While two-dimensional (2D) ultrasound (US) is sometimes used for real-time guidance, visualization of needle placement and depth is difficult and subject to variability and inaccuracy in 2D images. The close proximity to critical organs, in particular the rectum and bladder, can lead to serious complications. We have developed a three-dimensional (3D) transrectal US system and are investigating its use for intra-operative visualization of needle positions used in HDR gynaecological brachytherapy. As a proof-of-concept, four patients were imaged with post-insertion 3D US and x-ray CT. Using software developed in our laboratory, manual rigid registration of the two modalities was performed based on the perineal template's vaginal cylinder. The needle tip and a second point along the needle path were identified for each needle visible in US. The difference between modalities in the needle trajectory and needle tip position was calculated for each identified needle. For the 60 needles placed, the mean trajectory difference was 3.23 +/- 1.65° across the 53 visible needle paths and the mean difference in needle tip position was 3.89 +/- 1.92 mm across the 48 visible needles tips. Based on the preliminary results, 3D transrectal US shows potential for the development of a 3D US-based needle guidance system for interstitial gynaecological brachytherapy.

  17. Salvage brachytherapy in combination with interstitial hyperthermia for locally recurrent prostate carcinoma following external beam radiation therapy: a prospective phase II study.

    PubMed

    Kukiełka, Andrzej M; Strnad, Vratislav; Stauffer, Paul; Dąbrowski, Tomasz; Hetnał, Marcin; Nahajowski, Damian; Walasek, Tomasz; Brandys, Piotr; Matys, Robert

    2015-06-01

    Optimal treatment for patients with only local prostate cancer recurrence after external beam radiation therapy (EBRT) failure remains unclear. Possible curative treatments are radical prostatectomy, cryosurgery, and brachytherapy. Several single institution series proved that high-dose-rate brachytherapy (HDRBT) and pulsed-dose-rate brachytherapy (PDRBT) are reasonable options for this group of patients with acceptable levels of genitourinary and gastrointestinal toxicity. A standard dose prescription and scheme have not been established yet, and the literature presents a wide range of fractionation protocols. Furthermore, hyperthermia has shown the potential to enhance the efficacy of re-irradiation. Consequently, a prospective trial is urgently needed to attain clear structured prospective data regarding the efficacy of salvage brachytherapy with adjuvant hyperthermia for locally recurrent prostate cancer. The purpose of this report is to introduce a new prospective phase II trial that would meet this need. The primary aim of this prospective phase II study combining Iridium-192 brachytherapy with interstitial hyperthermia (IHT) is to analyze toxicity of the combined treatment; a secondary aim is to define the efficacy (bNED, DFS, OS) of salvage brachytherapy. The dose prescribed to PTV will be 30 Gy in 3 fractions for HDRBT, and 60 Gy in 2 fractions for PDRBT. During IHT, the prostate will be heated to the range of 40-47°C for 60 minutes prior to brachytherapy dose delivery. The protocol plans for treatment of 77 patients. PMID:26207116

  18. High dose rate sources in remote afterloading brachytherapy: Implications for intracavitary and interstitial treatment of carcinoma

    SciTech Connect

    Syzek, E.J.; Bogardus, C.R. Jr. )

    1990-11-01

    Remote afterloading brachytherapy provides effective cancer treatment with zero personnel radiation exposure compared to conventional low dose rate systems requiring inpatient use of iridium, radium, or cesium sources. Clinical use of high dose rate brachytherapy is broadened to encompass curative treatment of cervical, endometrial, endobronchial, head and neck, esophageal, rectal, and prostatic carcinomas as well as palliation of intra-abdominal metastasis intraoperatively. Complications encountered with high dose rate sources will be compared to those of low dose rate systems commonly used in conjunction with external beam irradiation. Radiobiological effectiveness and economic benefits will be addressed to provide support for use of remote afterloading using high dose rate brachytherapy in palliative and curative treatment of selected carcinoma. 36 refs.

  19. Matched-pair analysis and dosimetric variations of two types of software for interstitial permanent brachytherapy for prostate cancer.

    PubMed

    Ishiyama, Hiromichi; Nakamura, Ryuji; Satoh, Takefumi; Tanji, Susumu; Teh, Bin S; Uemae, Mineko; Baba, Shiro; Hayakawa, Kazushige

    2012-01-01

    The purpose of this study was to determine whether identical dosimetric results could be achieved using different planning software for permanent interstitial brachytherapy for prostate cancer. Data from 492 patients treated with brachytherapy were used for matched-pair analysis. Interplant and Variseed were used as software for ultrasound-based treatment planning. Institution, neoadjuvant hormonal therapy, prostate volume, and source strength were used for factors to match the 2 groups. The study population comprised of 126 patients with treatment planning using Interplant software and 127 matched patients using Variseed software. Dosimetric results were compared between the 2 groups. The Variseed group showed significantly higher values for dose covering 90% of prostate volume (pD90), prostate volume covered by 150% of prescription dose (pV150), and dose covering 30% of the urethra (uD30) compared with the Interplant group. Our results showed that use of different software could lead to different dosimetric results, which might affect the clinical outcomes. PMID:21937217

  20. Projector-Based Augmented Reality for Intuitive Intraoperative Guidance in Image-Guided 3D Interstitial Brachytherapy

    SciTech Connect

    Krempien, Robert Hoppe, Harald; Kahrs, Lueder; Daeuber, Sascha; Schorr, Oliver; Eggers, Georg; Bischof, Marc; Munter, Marc W.; Debus, Juergen; Harms, Wolfgang

    2008-03-01

    Purpose: The aim of this study is to implement augmented reality in real-time image-guided interstitial brachytherapy to allow an intuitive real-time intraoperative orientation. Methods and Materials: The developed system consists of a common video projector, two high-resolution charge coupled device cameras, and an off-the-shelf notebook. The projector was used as a scanning device by projecting coded-light patterns to register the patient and superimpose the operating field with planning data and additional information in arbitrary colors. Subsequent movements of the nonfixed patient were detected by means of stereoscopically tracking passive markers attached to the patient. Results: In a first clinical study, we evaluated the whole process chain from image acquisition to data projection and determined overall accuracy with 10 patients undergoing implantation. The described method enabled the surgeon to visualize planning data on top of any preoperatively segmented and triangulated surface (skin) with direct line of sight during the operation. Furthermore, the tracking system allowed dynamic adjustment of the data to the patient's current position and therefore eliminated the need for rigid fixation. Because of soft-part displacement, we obtained an average deviation of 1.1 mm by moving the patient, whereas changing the projector's position resulted in an average deviation of 0.9 mm. Mean deviation of all needles of an implant was 1.4 mm (range, 0.3-2.7 mm). Conclusions: The developed low-cost augmented-reality system proved to be accurate and feasible in interstitial brachytherapy. The system meets clinical demands and enables intuitive real-time intraoperative orientation and monitoring of needle implantation.

  1. Endobronchial interstitial brachytherapy using a bronchofiberscope with a flexible injector system

    SciTech Connect

    Mittal, B.B.; Matuschak, G.; Culpepper, J.

    1984-07-01

    A new flexible implantation system for endobronchial brachytherapy is described. This system was used to implant Au-198 seeds in the endobronchial tumors of two patients; discomfort and morbidity were minimal. The flexible injector system may be an improvement over the rigid system for endobronchial implantation in most patients.

  2. Outcomes of High-Dose-Rate Interstitial Brachytherapy in the Treatment of Locally Advanced Cervical Cancer: Long-term Results

    SciTech Connect

    Pinn-Bingham, Melva; Puthawala, Ajmel A.; Syed, A.M. Nisar; Sharma, Anil; DiSaia, Philip; Berman, Michael; Tewari, Krishnansu S.; Randall-Whitis, Leslie; Mahmood, Usama; Ramsinghani, Nilam; Kuo, Jeffrey; Chen, Wen-Pin; McLaren, Christine E.

    2013-03-01

    Purpose: The purpose of this study was to determine locoregional control (LRC), disease-free survival (DFS), and toxicity of high-dose-rate interstitial brachytherapy (HDR-ISBT) in the treatment of locally advanced cervical cancer. Methods and Materials: Between March 1996 and May 2009, 116 patients with cervical cancer were treated. Of these, 106 (91%) patients had advanced disease (International Federation of Gynecology and Obstetrics stage IIB-IVA). Ten patients had stage IB, 48 had stage II, 51 had stage III, and 7 had stage IVA disease. All patients were treated with a combination of external beam radiation therapy (EBRT) to the pelvis (5040 cGy) and 2 applications of HDR-ISBT to a dose of 3600 cGy to the implanted volume. Sixty-one percent of patients also received interstitial hyperthermia, and 94 (81%) patients received chemotherapy. Results: Clinical LRC was achieved in 99 (85.3%) patients. Three-year DFS rates were 59%, 67%, 71%, and 57% for patients with stage IB, II, III, and IVA disease, respectively. The 5-year DFS and overall survival rates for the entire group were 60% and 44%, respectively. Acute and late toxicities were within acceptable limits. Conclusions: Locally advanced cervical cancer patients for whom intracavitary BT is unsuitable can achieve excellent LRC and OS with a combination of EBRT and HDR-ISBT.

  3. Outcomes of High-Dose-Rate Interstitial Brachytherapy in the Treatment of Locally Advanced Cervical Cancer: Long-term Results

    PubMed Central

    Pinn-Bingham, Melva; Puthawala, Ajmel A.; Syed, A.M. Nisar; Sharma, Anil; DiSaia, Philip; Berman, Michael; Tewari, Krishnansu S.; Randall-Whitis, Leslie; Mahmood, Usama; Ramsinghani, Nilam; Kuo, Jeffrey; Chen, Wen-Pin; McLaren, Christine E.

    2013-01-01

    Purpose The purpose of this study was to determine locoregional control (LRC), disease-free survival (DFS), and toxicity of high-dose-rate interstitial brachytherapy (HDR-ISBT) in the treatment of locally advanced cervical cancer. Methods and Materials Between March 1996 and May 2009, 116 patients with cervical cancer were treated. Of these, 106 (91%) patients had advanced disease (International Federation of Gynecology and Obstetrics stage IIB-IVA). Ten patients had stage IB, 48 had stage II, 51 had stage III, and 7 had stage IVA disease. All patients were treated with a combination of external beam radiation therapy (EBRT) to the pelvis (5040 cGy) and 2 applications of HDR-ISBT to a dose of 3600 cGy to the implanted volume. Sixty-one percent of patients also received interstitial hyperthermia, and 94 (81%) patients received chemotherapy. Results Clinical LRC was achieved in 99 (85.3%) patients. Three-year DFS rates were 59%, 67%, 71%, and 57% for patients with stage IB, II, III, and IVA disease, respectively. The 5-year DFS and overall survival rates for the entire group were 60% and 44%, respectively. Acute and late toxicities were within acceptable limits. Conclusions Locally advanced cervical cancer patients for whom intracavitary BT is unsuitable can achieve excellent LRC and OS with a combination of EBRT and HDR-ISBT. PMID:22763030

  4. Assessing DNA structures with 125I radioprobing.

    PubMed

    Gaynutdinov, Timur I; Neumann, Ronald D; Panyutin, Igor G

    2010-01-01

    Iodine-125 radioprobing is based on incorporation of radioiodine into a defined position in a nucleic acid molecule. Decay of (125)I results in the emission of multiple, low-energy Auger electrons that, along with positively charged residual daughter nuclide, produce DNA strand breaks. The probability of such strand breaks at a given nucleotide is in inverse proportion to the distance from the (125)I atom to the sugar of that nucleotide. Therefore, conclusions can be drawn about the conformation or folding of a DNA or RNA molecule based on the distribution of (125)I decay-induced strand breaks. Here we describe in detail the application (125)I radioprobing for studying the conformation of quadruplex structures, and discuss the advantages and limitations of the method. PMID:20012420

  5. Distant Metastases Following Permanent Interstitial Brachytherapy for Patients With Clinically Localized Prostate Cancer

    SciTech Connect

    Taira, Al V.; Merrick, Gregory S.; Galbreath, Robert W.; Butler, Wayne M.; Lief, Jonathan; Adamovich, Edward; Wallner, Kent E.

    2012-02-01

    Purpose: Recent publications have suggested high-risk patients undergoing radical prostatectomy have a lower risk of distant metastases and improved cause-specific survival (CSS) than patients receiving definitive external beam radiation therapy (XRT). To date, none of these studies has compared distant metastases and CSS in brachytherapy patients. In this study, we evaluate such parameters in a consecutive cohort of brachytherapy patients. Methods and Materials: From April 1995 to June 2007, 1,840 consecutive patients with clinically localized prostate cancer were treated with brachytherapy. Risk groups were stratified according to National Comprehensive Cancer Network ( (www.nccn.org)) guidelines. Subgroups of 658, 893, and 289 patients were assigned to low, intermediate, and high-risk categories. Median follow-up was 7.2 years. Along with brachytherapy implantation, 901 (49.0%) patients received supplemental XRT, and 670 (36.4%) patients received androgen deprivation therapy (median duration, 4 months). The mode of failure (biochemical, local, or distant) was determined for each patient for whom therapy failed. Cause of death was determined for each deceased patient. Multiple parameters were evaluated for impact on outcome. Results: For the entire cohort, metastases-free survival (MFS) and CSS at 12 years were 98.1% and 98.2%, respectively. When rates were stratified by low, intermediate, and high-risk groups, the 12-year MFS was 99.8%, 98.1%, and 93.8% (p < 0.001), respectively. CSS rates were 99.8%, 98.0%, and 95.3% (p < 0.001) for low, intermediate, and high-risk groups, respectively. Biochemical progression-free survival was 98.7%, 95.9% and 90.4% for low, intermediate, and high-risk patients, respectively (p < 0.001). In multivariate Cox-regression analysis, MFS was mostly closely related to Gleason score and year of treatment, whereas CSS was most closely associated with Gleason score. Conclusions: Excellent CSS and MFS rates are achievable with high

  6. Natural History of Clinically Staged Low- and Intermediate-Risk Prostate Cancer Treated With Monotherapeutic Permanent Interstitial Brachytherapy

    SciTech Connect

    Taira, Al V.; Merrick, Gregory S.; Galbreath, Robert W.; Wallner, Kent E.; Butler, Wayne M.

    2010-02-01

    Purpose: To evaluate the natural history of clinically staged low- and intermediate-risk prostate cancer treated with permanent interstitial seed implants as monotherapy. Methods and Materials: Between April 1995 and May 2005, 463 patients with clinically localized prostate cancer underwent brachytherapy as the sole definitive treatment. Men who received supplemental external beam radiotherapy or androgen deprivation therapy were excluded. Dosimetric implant quality was determined based on the minimum dose that covered 90% of the target volume and the volume of the prostate gland receiving 100% of the prescribed dose. Multiple parameters were evaluated as predictors of treatment outcomes. Results: The 12-year biochemical progression-free survival (bPFS), cause-specific survival, and overall survival rates for the entire cohort were 97.1%, 99.7%, and 75.4%, respectively. Only pretreatment prostate-specific antigen level, percent positive biopsy cores, and minimum dose that covered 90% of the target volume were significant predictors of biochemical recurrence. The bPFS, cause-specific survival, and overall survival rates were 97.4%, 99.6%, and 76.2%, respectively, for low-risk patients and 96.4%, 100%, and 74.0%, respectively, for intermediate-risk patients. The bPFS rate was 98.8% for low-risk patients with high-quality implants versus 92.1% for those with less adequate implants (p < 0.01), and it was 98.3% for intermediate-risk patients with high-quality implants versus 86.4% for those with less adequate implants (p < 0.01). Conclusions: High-quality brachytherapy implants as monotherapy can provide excellent outcomes for men with clinically staged low- and intermediate-risk prostate cancer. For these men, a high-quality implant can achieve results comparable to high-quality surgery in the most favorable pathologically staged patient subgroups.

  7. WE-G-17A-05: Real-Time Catheter Localization Using An Active MR Tracker for Interstitial Brachytherapy

    SciTech Connect

    Wang, W; Damato, A; Viswanathan, A; Cormack, R; Penzkofer, T; Schmidt, E; Pan, L; Gilson, W; Seethamraju, R

    2014-06-15

    Purpose: To develop a novel active MR-tracking system which can provide accurate and rapid localization of brachytherapy catheters, and assess its reliability and spatial accuracy in comparison to standard catheter digitization using MR images. Methods: An active MR tracker for brachytherapy was constructed by adding three printed-circuit micro-coils to the shaft of a commercial metallic stylet. A gel phantom with an embedded framework was built, into which fifteen 14-Gauge catheters were placed, following either with parallel or crossed paths. The tracker was inserted sequentially into each catheter, with MR-tracking running continuously. Tracking was also performed during the tracker's removal from each catheter. Catheter trajectories measured from the insertion and the removal procedures using the same micro-coil were compared, as well as trajectories obtained using different micro-coils. A 3D high-resolution MR image dataset of the phantom was acquired and imported into a treatment planning system (TPS) for catheter digitization. A comparison between MR-tracked positions and positions digitized from MR images by TPS was performed. Results: The MR tracking shows good consistency for varying catheter paths and for all micro-coils (mean difference ∼1.1 mm). The average distance between the MR-tracking trajectory and catheter digitization from the MR images was 1.1 mm. Ambiguity in catheter assignment from images due to crossed paths was resolved by active tracking. When tracking was interleaved with imaging, real-time images were continuously acquired at the instantaneous tip positions and displayed on an external workstation. Conclusion: The active MR tracker may be used to provide an independent measurement of catheter location in the MR environment, potentially eliminating the need for subsequent CT. It may also be used to control realtime imaging of catheter placement. This will enable MR-based brachytherapy planning of interstitial implants without ionizing

  8. SU-E-T-507: Interfractional Variation of Fiducial Marker Position During HDR Brachytherapy with Cervical Interstitial Needle Template

    SciTech Connect

    Shen, S; Kim, R; Benhabib, S; Araujo, J; Burnett, L; Duan, J; Popple, R; Wu, X; Cardan, R; Brezovich, I

    2014-06-01

    Purpose: HDR brachytherapy using interstitial needle template for cervical cancer is commonly delivered in 4-5 fractions. Routine verification of needle positions before each fraction is often based on radiographic imaging of implanted fiducial markers. The current study evaluated interfractional displacement of implanted fiducial markers using CT images. Methods: 9 sequential patients with cervical interstitial needle implants were evaluated. The superior and inferior borders of the target volumes were defined by fiducial markers in planning CT. The implant position was verified with kV orthogonal images before each fraction. A second CT was acquired prior 3rd fraction (one or 2 days post planning CT). Distances from inferior and superior fiducial markers to pubic symphysis plane (perpendicular to vaginal obtulator)were measured. Distance from needle tip of a reference needle (next to the inferior marker) to the pubic symphysis plane was also determined. The difference in fiducial marker distance or needle tip distance between planning CT and CT prior 3rd fraction were measured to assess markers migration and needle displacement. Results: The mean inferior marker displacement was 4.5 mm and ranged 0.9 to 11.3 mm. The mean superior marker displacement was 2.7 mm and ranged 0 to 10.4 mm. There was a good association between inferior and superior marker displacement (r=0.95). Mean averaged inferior and superior marker displacement was 3.3 mm and ranged from 0.1 to 10.9 mm, with a standard deviation of 3.2 mm. The mean needle displacement was 5.6 mm and ranged 0.2 to 15.6 mm. Needle displacements were reduced (p<0.05) after adjusting according to needle-to-fiducials distance. Conclusion: There were small fiducial marker displacements between HDR fractions. Our study suggests a target margin of 9.7 mm to cover interfractional marker displacements (in 95% cases) for pretreatment verification based on radiographic imaging.

  9. Multiple-estimate Monte Carlo calculation of the dose rate constant for a cesium-131 interstitial brachytherapy seed

    SciTech Connect

    Wittman, Richard S.; Fisher, Darrell R.

    2007-01-03

    The purpose of this study was to calculate a more accurate dose rate constant for the Cs-131 (model CS-1, IsoRay Medical, Inc., Richland, Washington) interstitial brachytherapy seed. Previous measurements of the dose rate constant for this seed have been reported by others with incongruity. Recent direct measurements by thermoluminescence dosimetry and by gamma-ray spectroscopy were about 15 percent greater than earlier thermoluminescence dosimetry measurements. Therefore, we set about to calculate independent values by a Monte Carlo approach that combined three estimates as a consistency check, and to quantify the computational uncertainty. The calculated dose rate constant for the Cs-131 seed was 1.040 cGy h^{-1} U^{-1} for an ionization chamber model and 1.032 cGy h^{-1} U^{-1} for a circular ring model. A formal value of 2.2% uncertainty was calculated for both values. The range of our multi-estimate values were from 1.032 cGy h^{-1} U^{-1} to 1.061 cGy h^{-1} U^{-1}. We also modeled three I-125 seeds with known dose rate constants to test the accuracy of this study's approach.

  10. [The first experience in interstitial brachytherapy for primary and metastatic tumors of the brain].

    PubMed

    Bentsion, D L; Gvozdev, P B; Sakovich, V P; Fialko, N V; Kolotvinov, V S; Baiankina, S N

    2006-01-01

    In 2001-2002, the authors performed a course of brachytherapy in 15 patients with inoperable primary, recurrent, and metastatic brain tumors. The histostructural distribution was as follows: low-grade astrocytoma (grade II according to the WHO classification) in 2 patients, anaplastic astrocytoma (AA) in 3, glioblastoma multiforme (GBM) in 5. Five patients had solid tumor deposits in the brain. Computer tomographic (CT) and magnetic resonance imaging (MRI) data were used to define a path for forthcoming biopsy and implantation at a "Stryker" navigation station, by taking into account the anatomy of the brain, vessels, and functionally significant areas. After having histological findings, plastic intrastats whose number had been determined by the volume of a target were implanted into a tumor by the predetermined path. Dosimetric planning was accomplished by using CT and MRI images on an "Abacus" system. The final stage involved irradiation on a "GammaMed plus" with a source of 192Ir. Irradiation was given, by hyperfractionating its dose (3-4 Gy twice daily at an interval of 4-5 hours) to the total focal dose (TFD) of 36-44 Gy. Patients with gliomas untreated with radiation also underwent external radiation in a TFD of 54-56 Gy and patients with brain metastases received total external irradiation of the brain in a TFD of 36-40 Gy. The tolerance of a course of irradiation was fair. In patients with AA and GBM, one-year survival was observed in 66 and 60%, respectively; in those having metastasis, it was in 20%. Six patients died from progressive disease. All patients with low-grade astrocytoma and one patient with anaplastic astrocytoma were alive at month 24 after treatment termination. The mean lifespan of patients with malignant gliomas and solid tumor metastasis was 11.5 and 5.8 months, respectively. Brachytherapy is a noninvasive and tolerable mode of radiotherapy that increases survival in some groups of patients with inoperable brain tumors. PMID:16739930

  11. Dosimetry of the {sup 198}Au source used in interstitial brachytherapy

    SciTech Connect

    Dauffy, Lucile S.; Braby, Leslie A.; Berner, Barry M.

    2005-06-15

    The American Association of Physicists in Medicine Task Group 43 reports, AAPM TG-43 and its update TG-43U1, provide an analytical model and a dosimetry protocol for brachytherapy dose calculations, as well as documentation and results for some sealed sources. The radionuclide {sup 198}Au (T{sub 1/2}=2.70 days, E{gamma}=412 keV) has been used in the form of seeds for brachytherapy treatments including brain, eye, and prostate tumors. However, TG-43 reports have no data for {sup 198}Au seeds, and none have previously been obtained. For that reason, and because of the conversion of most treatment planning systems to TG-43 based methods, both Monte Carlo calculations (MCNP 4C2) and thermoluminescent dosimeters (TLDs) are used in this work to determine these data. The geometric variation in dose is measured using an array of TLDs in a solid water phantom, and the seed activity is determined using a high purity germanium detector (HPGe) and a well ionization chamber. The results for air kerma strength, S{sub k}, per unit apparent activity, are 2.063 (MCNP) and 2.089 (measured) U mCi{sup -1}, values close to those published in 1991 in the AAPM Task Group 32 report. The dose rate constant, {lambda}, is found equal to 1.115 (MCNP) and 1.095 (measured) cGy h{sup -1} U{sup -1}. The radial dose function, g(r), anisotropy function, F(r,{theta}), and anisotropy factor, {phi}{sub an}(r), are also given.

  12. SU-F-19A-12: Split-Ring Applicator with Interstitial Needle for Improved Volumetric Coverage in HDR Brachytherapy for Cervical Cancer

    SciTech Connect

    Sherertz, T; Ellis, R; Colussi, V; Mislmani, M; Traughber, B; Herrmann, K; Podder, T

    2014-06-15

    Purpose: To evaluate volumetric coverage of a Mick Radionuclear titanium Split-Ring applicator (SRA) with/without interstitial needle compared to an intracavitary Vienna applicator (VA), interstitial-intracavitary VA, and intracavitary ring and tandem applicator (RTA). Methods: A 57 year-old female with FIGO stage IIB cervical carcinoma was treated following chemoradiotherapy (45Gy pelvic and 5.4Gy parametrial boost) with highdose- rate (HDR) brachytherapy to 30Gy in 5 fractions using a SRA. A single interstitial needle was placed using the Ellis Interstitial Cap for the final three fractions to increase coverage of left-sided gross residual disease identified on 3T-MRI. High-risk (HR) clinical target volume (CTV) and intermediate-risk (IR) CTV were defined using axial T2-weighted 2D and 3D MRI sequences (Philips PET/MRI unit). Organs-at-risks (OARs) were delineated on CT. Oncentra planning system was used for treatment optimization satisfying GEC-ESTRO guidelines for target coverage and OAR constraints. Retrospectively, treatment plans (additional 20 plans) were simulated using intracavitary SRA (without needle), intracavitary VA (without needle), interstitial-intracavitary VA, and intracavitary RTA with this same patient case. Plans were optimized for each fraction to maintain coverage to HR-CTV. Results: Interstitial-intracavitary SRA achieved the following combined coverage for external radiation and brachytherapy (EQD2): D90 HR-CTV =94.6Gy; Bladder-2cc =88.9Gy; Rectum-2cc =65.1Gy; Sigmoid-2cc =48.9Gy; Left vaginal wall (VW) =103Gy, Right VW =99.2Gy. Interstitial-intracavitary VA was able to achieve identical D90 HR-CTV =94.6Gy, yet Bladder-2cc =91.9Gy (exceeding GEC-ESTRO recommendations of 2cc<90Gy) and Left VW =120.8Gy and Right VW =115.5Gy. Neither the SRA nor VA without interstitial needle could cover HR-CTV adequately without exceeding dose to Bladder-2cc. Conventional RTA was unable to achieve target coverage for the HR-CTV >80Gy without severely

  13. High-Dose-Rate Interstitial Brachytherapy as Monotherapy for Clinically Localized Prostate Cancer: Treatment Evolution and Mature Results

    SciTech Connect

    Zamboglou, Nikolaos; Tselis, Nikolaos; Baltas, Dimos; Buhleier, Thomas; Martin, Thomas; Milickovic, Natasa; Papaioannou, Sokratis; Ackermann, Hanns; Tunn, Ulf W.

    2013-03-01

    Purpose: To report the clinical outcome of high-dose-rate (HDR) interstitial (IRT) brachytherapy (BRT) as sole treatment (monotherapy) for clinically localized prostate cancer. Methods and Materials: Between January 2002 and December 2009, 718 consecutive patients with clinically localized prostate cancer were treated with transrectal ultrasound (TRUS)-guided HDR monotherapy. Three treatment protocols were applied; 141 patients received 38.0 Gy using one implant in 4 fractions of 9.5 Gy with computed tomography-based treatment planning; 351 patients received 38.0 Gy in 4 fractions of 9.5 Gy, using 2 implants (2 weeks apart) and intraoperative TRUS real-time treatment planning; and 226 patients received 34.5 Gy, using 3 single-fraction implants of 11.5 Gy (3 weeks apart) and intraoperative TRUS real-time treatment planning. Biochemical failure was defined according to the Phoenix consensus, and toxicity was evaluated using Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 52.8 months. The 36-, 60-, and 96-month biochemical control and metastasis-free survival rates for the entire cohort were 97%, 94%, and 90% and 99%, 98%, and 97%, respectively. Toxicity was scored per event, with 5.4% acute grade 3 genitourinary and 0.2% acute grade 3 gastrointestinal toxicity. Late grade 3 genitourinary and gastrointestinal toxicities were 3.5% and 1.6%, respectively. Two patients developed grade 4 incontinence. No other instance of grade 4 or greater acute or late toxicity was reported. Conclusion: Our results confirm IRT-HDR-BRT is safe and effective as monotherapy for clinically localized prostate cancer.

  14. Dosimetry of permanent interstitial prostate brachytherapy for an interoperative procedure, using O-arm based CT and TRUS

    PubMed Central

    Sekiguchi, Akane; Satoh, Takefumi; Tsumura, Hideyasu; Takenaka, Kouji; Kawakami, Shogo; Tabata, Ken-ichi; Kobayashi, Kentaro; Iwamura, Masatsugu; Hayakawa, Kazushige

    2016-01-01

    Purpose The aim of this report is dosimetric evaluation for an intraoperative fusion computed tomography (CT) as a superior predictor of 1-month CT based dosimetry in comparison to transrectal ultrasound (TRUS) in permanent interstitial prostate brachytherapy. Material and methods Data of 65 patients treated with seed implantation were analyzed. All procedures has been performed with patients in the lithotomy position inside the O-arm system. An end-fine probe is used as a landmark to fuse TRUS and O-arm-based CT images. There was no difference in the patient's position, probe position, and timing of image acquisition between the two imaging modalities. Dose-volume histogram (DVH) parameters such as the dose to 90% of prostate volume (D90) has been analyzed. Results The area under the curve of the receiver operating characteristic tended to be larger on fusion CT than on TRUS for most DVH parameters (71.85% vs. 59.59% for D90; p = 0.07). Significant relationships between fusion CT and 1-month CT were confirmed using Pearson's correlation coefficients for most DVH parameters (R = 0.48, p < 0.01 for D90), although the relationship between TRUS and 1-month CT was poor. Large dose reduction (35 Gy for D90) was seen from TRUS to fusion CT, especially in patients with high body weight and small prostate volume. Conclusions Intraoperative fusion CT appears to have higher predictive power for 1-month CT-based dosimetry than TRUS. A prospective trial using fusion CT-based planning is warranted. PMID:26985192

  15. Intracavitary combined with CT-guided interstitial brachytherapy for locally advanced uterine cervical cancer: introduction of the technique and a case presentation.

    PubMed

    Wakatsuki, Masaru; Ohno, Tatsuya; Yoshida, Daisaku; Noda, Shin-ei; Saitoh, Jun-ichi; Shibuya, Kei; Katoh, Hiroyuki; Suzuki, Yoshiyuki; Takahashi, Takeo; Nakano, Takashi

    2011-01-01

    We report a new technique of brachytherapy consisting of intracavitary combined with computed tomography (CT)-guided interstitial brachytherapy for locally advanced cervical cancer. A Fletcher-Suit applicator and trocar point needles were used for performing high-dose rate brachytherapy under in-room CT guidance. First, a tandem and ovoids were implanted into the patient's vagina and uterus by conventional brachytherapy method. Based on clinical examination and MRI/CT imaging, operating radiation oncologists decided the positions of insertion in the tumor and the depth of the needles from the upper surface of the ovoid. Insertion of the needle applicator was performed from the vaginal vault inside the ovoid within the tumor under CT guidance. In treatment planning, dwell positions and time adaptations within the tandem and ovoids were performed first for optimization based on the Manchester system, and then stepwise addition of dwell positions within the needle was continued. Finally, dwell positions and dwell weights were manually modified until dose-volume constraints were optimally matched. In our pilot case, the dose of D90 to high-risk clinical target volume was improved from 3.5 Gy to 6.1 Gy by using our hybrid method on the dose-volume histogram. D1cc of the rectum, bladder and sigmoid colon by our hybrid method was 4.8 Gy, 6.4 Gy and 3.5 Gy, respectively. This method consists of advanced image-guided brachytherapy that can be performed safely and accurately. This approach has the potential of increasing target coverage, treated volume, and total dose without increasing the dose to organs at risk. PMID:21293072

  16. The theoretical basis and clinical methodology for stereotactic interstitial brain tumor irradiation using iododeoxyuridine as a radiation sensitizer and samarium-145 as a brachytherapy source

    SciTech Connect

    Goodman, J.H.; Gahbauer, R.A.; Kanellitsas, C.; Clendenon, N.R. ); Laster, B.H.; Fairchild, R.G. )

    1989-01-01

    High grade astrocytomas have proven resistant to all conventional therapy. A technique to produce radiation enhancement during interstitial brain tumor irradiation by using a radiation sensitizer (IdUrd) and by stimulation of Auger electron cascades through absorption of low energy photons in iodine (Photon activation) is described. Clinical studies using IdUrd, {sup 192}Ir as a brachytherapy source, and external radiation have produced promising results. Substituting samarium-145 for {sup 192}Ir in this protocol is expected to produce enhanced results. 15 refs.

  17. More accurate fitting of {sup 125}I and {sup 103}Pd radial dose functions

    SciTech Connect

    Taylor, R. E. P.; Rogers, D. W. O.

    2008-09-15

    In this study an improved functional form for fitting the radial dose functions, g(r), of {sup 125}I and {sup 103}Pd brachytherapy seeds is presented. The new function is capable of accurately fitting radial dose functions over ranges as large as 0.05 cm{<=}r{<=}10 cm for {sup 125}I seeds and 0.10 cm{<=}r{<=}10 cm for {sup 103}Pd seeds. The average discrepancies between fit and calculated data are less than 0.5% over the full range of fit and maximum discrepancies are 2% or less. The fitting function is also capable of accounting for the sharp increase in g(r) (upturn) seen for some sources for r<0.1 cm. This upturn has previously been attributed to the breakdown of the approximation of the sources as a line, however, in this study we demonstrate that another contributing factor is the 4.5 keV characteristic x-rays emitted from the Ti seed casing. Radial dose functions are calculated for 18 {sup 125}I seeds and 9 {sup 103}Pd seeds using the EGSnrc Monte Carlo user-code BrachyDose. Fitting coefficients of the new function are tabulated for all 27 seeds. Extrapolation characteristics of the function are also investigated. The new functional form is an improvement over currently used fitting functions with its main strength being the ability to accurately fit the rapidly varying radial dose function at small distances. The new function is an excellent candidate for fitting the radial dose function of all {sup 103}Pd and {sup 125}I brachytherapy seeds and will increase the accuracy of dose distributions calculated around brachytherapy seeds using the TG-43 protocol over a wider range of data. More accurate values of g(r) for r<0.5 cm may be particularly important in the treatment of ocular melanoma.

  18. Multi-Parametric MRI-Directed Focal Salvage Permanent Interstitial Brachytherapy for Locally Recurrent Adenocarcinoma of the Prostate: A Novel Approach

    PubMed Central

    Wallace, T.; Avital, I.; Stojadinovic, A.; Brücher, B.L.D.M.; Cote, E.; Yu, J.

    2013-01-01

    Even with the technological advances of dose-escalated IMRT with the addition of the latest image guidance technologies, local failures still occur. The combination of MRI-based imaging techniques can yield quantitative information that reflects on the biological properties of prostatic tissues. These techniques provide unique information that can be used for tumor detection in the treated gland. With the advent of these improved imaging modalities, it has become possible to more effectively image local recurrences within the prostate gland. With better imaging, these focal recurrences can be differentially targeted with salvage brachytherapy minimizing rectal and bladder toxicity. Here we report a novel use of MRI-directed focal brachytherapy after local recurrence. This technique offers a unique opportunity to safely and successfully treat recurrent prostate cancer, previously treated with definitive radiation therapy. The use of multi-parametric MRI-directed focal salvage permanent interstitial brachytherapy for locally recurrent adenocarcinoma of the prostate is a promising strategy to avoid more aggressive and expensive treatments that are associated with increased morbidity, potentially improving survival at potentially lower costs. PMID:23412660

  19. Vaginal tolerance of CT based image-guided high-dose rate interstitial brachytherapy for gynecological malignancies

    PubMed Central

    2014-01-01

    Background Purpose of this study was to identify predictors of vaginal ulcer after CT based three-dimensional image-guided high-dose-rate interstitial brachytherapy (HDR-ISBT) for gynecologic malignancies. Methods Records were reviewed for 44 female (14 with primary disease and 30 with recurrence) with gynecological malignancies treated with HDR-ISBT with or without external beam radiation therapy. The HDR-ISBT applicator insertion was performed with image guidance by trans-rectal ultrasound and CT. Results The median clinical target volume was 35.5 ml (2.4-142.1 ml) and the median delivered dose in equivalent dose in 2 Gy fractions (EQD2) for target volume D90 was 67.7 Gy (48.8-94.2 Gy, doses of external-beam radiation therapy and brachytherapy were combined). For re-irradiation patients, median EQD2 of D2cc for rectum and bladder, D0.5cc, D1cc, D2cc, D4cc, D6cc and D8cc for vaginal wall was 91.1 Gy, 100.9 Gy, 260.3 Gy, 212.3 Gy, 170.1 Gy, 117.1 Gy, 105.2 Gy, and 94.7 Gy, respectively. For those without prior radiation therapy, median EQD2 of D2cc for rectum and bladder, D0.5cc, D1cc, D2cc, D4cc, D6cc and D8cc for vaginal wall was 56.3 Gy, 54.3 Gy, 147.4 Gy, 126.2 Gy, 108.0 Gy, 103.5 Gy, 94.7 Gy, and 80.7 Gy, respectively. Among five patients with vaginal ulcer, three had prior pelvic radiation therapy in their initial treatment and three consequently suffered from fistula formation. On univariate analysis, re-irradiation and vaginal wall D2cc in EQD2 was the clinical predictors of vaginal ulcer (p = 0.035 and p = 0.025, respectively). The ROC analysis revealed that vaginal wall D2cc is the best predictor of vaginal ulcer. The 2-year incidence rates of vaginal ulcer in the patients with vaginal wall D2cc in EQD2 equal to or less than 145 Gy and over 145 Gy were 3.7% and 23.5%, respectively, with a statistically significant difference (p = 0.026). Conclusions Re-irradiation and vaginal D2cc is a significant predictor of vaginal ulcer after HDR-ISBT for

  20. Value of Combined PET/CT for Radiation Planning in CT-Guided Percutaneous Interstitial High-Dose-Rate Single-Fraction Brachytherapy for Colorectal Liver Metastases

    SciTech Connect

    Steffen, Ingo G.; Wust, Peter; Ruehl, Ricarda

    2010-07-15

    Purpose: To determine the additional value of fluorodeoxyglucose-positron emission tomography (PET) for clinical target volume definition in the planning of computed tomography (CT)-guided interstitial brachytherapy for liver metastases. Patients and Methods: A total of 19 patients with liver metastases from colorectal cancer treated in 25 sessions were included in the present study. All patients had undergone fluorodeoxyglucose-PET for patient evaluation before interstitial CT-guided brachytherapy. A contrast-enhanced CT scan of the upper abdomen was obtained for radiation planning. The clinical target volume (CTV) was defined by a radiation oncologist and radiologist. After registration of the CT scan with the PET data set, the target volume was defined again using the fusion images. Results: PET revealed one additional liver lesion that was not visible on CT. The median CT-CTV (defined using CT and magnetic resonance imaging) was 68 cm{sup 3} (range 4-260). The PET/CT-CTV (median, 78 cm{sup 3}; range, 4-273) was significantly larger, with a median gain of 24.5% (interquartile range, 2.1-71.5%; p = .022). An increased CTV was observed in 15 cases and a decrease in 6; in 4 cases, the CT-CTV and PET/CT-CTV were equal. Incomplete dose coverage of PET/CT-CTVs was indicative of early local progression (p = .004); however, CT-based radiation plans did not show significant differences in the local control rates when stratified by dose coverage. Conclusion: Retrospective implementation of fluorodeoxyglucose-PET for CTV specification for CT-guided brachytherapy for colorectal liver metastases revealed a significant change in the CTVs. Additional PET-positive tumor regions with incomplete dose coverage could explain unexpected early local progression.

  1. Accelerated Partial Breast Irradiation: 5-Year Results of the German-Austrian Multicenter Phase II Trial Using Interstitial Multicatheter Brachytherapy Alone After Breast-Conserving Surgery

    SciTech Connect

    Strnad, Vratislav; Hildebrandt, Guido; Poetter, Richard; Hammer, Josef; Hindemith, Marion; Resch, Alexandra; Spiegl, Kurt; Lotter, Michael; Uter, Wolfgang; Bani, Mayada; Kortmann, Rolf-Dieter; Beckmann, Matthias W.; Fietkau, Rainer; Ott, Oliver J.

    2011-05-01

    Purpose: To evaluate the impact of accelerated partial breast irradiation on local control, side effects, and cosmesis using multicatheter interstitial brachytherapy as the sole method for the adjuvant local treatment of patients with low-risk breast cancer. Methods and Materials: 274 patients with low-risk breast cancer were treated on protocol. Patients were eligible for the study if the tumor size was < 3 cm, resection margins were clear by at least 2 mm, no lymph node metastases existed, age was >35 years, hormone receptors were positive, and histologic grades were 1 or 2. Of the 274 patients, 175 (64%) received pulse-dose-rate brachytherapy (D{sub ref} = 50 Gy). and 99 (36%) received high-dose-rate brachytherapy (D{sub ref} = 32.0 Gy). Results: Median follow-up was 63 months (range, 9-103). Only 8 of 274 (2.9%) patients developed an ipsilateral in-breast tumor recurrence at the time of analysis. The 5-year actuarial local recurrence-free survival probability was 98%. The 5- year overall and disease-free survival probabilities of all patients were 97% and 96%, respectively. Contralateral in-breast malignancies were detected in 2 of 274 (0.7%) patients, and distant metastases occurred in 6 of 274 (2.2%). Late side effects {>=}Grade 3 (i.e., breast tissue fibrosis and telangiectasia) occurred in 1 patient (0.4%, 95%CI:0.0-2.0%) and 6 patients (2.2%, 95%CI:0.8-4.7%), respectively. Cosmetic results were good to excellent in 245 of 274 patients (90%). Conclusions: The long-term results of this prospective Phase II trial confirm that the efficacy of accelerated partial breast irradiation using multicatheter brachytherapy is comparable with that of whole breast irradiation and that late side effects are negligible.

  2. 125I Measurements for Occupational Exposure Assessment

    NASA Astrophysics Data System (ADS)

    Silva, L.; Pinhão, N. R.

    2008-08-01

    Whenever there is a risk of occupational exposure to dispersible radioactive material, it is necessary to have a monitoring program to assess the effective dose arising from the intake of radionuclides by workers. In this paper we present our experience in bioassay measurements of 125I in urine samples of workers using high resolution gamma spectrometry. For a 24-hour excretion period, we found activity values of the order of one Bq and estimated the committed effective doses to be less than one μSv. Although very small, these values led to a re-evaluation and improvement of the laboratory safety conditions. We discuss the calibration procedure followed for the activity measurements, the estimation of the uncertainty in the excreted activity, the calculation of detection and quantification limits and estimation of performance indicators. Aspects regarding the spectral analysis, true coincidence summing and matrix effects are also considered.

  3. Effect of pedicle fixation combined with 125I seed implantation for metastatic thoracolumbar tumors

    PubMed Central

    Qian, Jiale; Bao, Zhaohua; Zou, Jun; Yang, Huilin

    2016-01-01

    Purpose The aim of this study was to investigate the clinical efficacy of pedicle fixation combined with 125I brachytherapy in treating metastatic thoracolumbar tumors. Patients and methods A retrospective analysis of the clinical data of seven metastatic thoracolumbar tumor patients who received pedicle fixation combined with radioactive 125I seed implantation brachytherapy in our department between January 2009 and December 2013 was performed. The visual analog scale (VAS) for pain and the Karnofsky performance status (KPS) score before the operation and 1, 6, and 12 months after the operation were observed and recorded. The changes in the scores at each time point were compared. Results All the patients underwent a successful operation, without any complications during their hospitalization. All the patients received postoperative follow-up, and the duration of follow-up was 15–50 months, with an average of 32.2 months. One pancreatic cancer patient died of liver failure and hypoproteinemia 28 months post surgery. The VAS scores of patients before the operation and 1, 6, and 12 months after the operation were 7.43±0.98, 2.71±0.49, 3.00±0.82, and 4.29±0.98, respectively; the KPS scores were 52.9±9.5, 84.3±5.3, 75.7±5.3, and 72.9±4.9, respectively. These results suggest that the VAS score at each time point was significantly decreased compared with that before the operation, while the KPS score was significantly increased compared with that before the operation. Both differences had statistical significance (P<0.05). Conclusion As a therapy for advanced malignant tumors with thoracolumbar metastasis, pedicle fixation combined with 125I brachytherapy can effectively relieve short-term pain and improve patient’s quality of life. PMID:27274307

  4. Measurement of /sup 125/I-low density lipoprotein uptake in selected tissues of the squirrel monkey by quantitative autoradiography

    SciTech Connect

    Tompkins, R.G.; Schnitzer, J.J.; Yarmush, M.L.; Colton, C.K.; Smith, K.A.

    1988-09-01

    A recently developed technique of absolute quantitative light microscopic autoradiography of /sup 125/I-labeled proteins in biologic specimens was used to measure /sup 125/I-low density lipoprotein (/sup 125/I-LDL) concentration levels in various tissues of the squirrel monkey after 30 minutes of in vivo LDL circulation. Liver and adrenal cortex exhibited high /sup 125/I-LDL concentrations, presumably because of binding to specific cell surface receptors and/or internalization in vascular beds with high permeability to LDL. High tissue concentrations of LDL were associated with the zona fasciculata and reticularis of the adrenal cortex and the interstitial cells of Leydig in the testis; significantly lower levels of /sup 125/I-LDL were observed in the adrenal medulla, the zona glomerulosa, and germinal centers of the testis. Contrary to previous reports, low /sup 125/I-LDL concentrations were observed throughout the gastrointestinal tract and in lymph nodes. In addition, multiple arterial intramural focal areas of high /sup 125/I-LDL concentrations were identified in arteries supplying the adrenal gland, lymph node, small bowel, and liver.

  5. Accelerated partial breast irradiation: An analysis of variables associated with late toxicity and long-term cosmetic outcome after high-dose-rate interstitial brachytherapy

    SciTech Connect

    Wazer, David E. . E-mail: dwazer@tufts-nemc.org; Kaufman, Seth; Cuttino, Laurie; Di Petrillo, Thomas; Arthur, Douglas W.

    2006-02-01

    Purpose: To perform a detailed analysis of variables associated with late tissue effects of high-dose-rate (HDR) interstitial brachytherapy accelerated partial breast irradiation (APBI) in a large cohort of patients with prolonged follow-up. Methods and Materials: Beginning in 1995, 75 women with Stage I/II breast cancer were enrolled in identical institutional trials evaluating APBI as monotherapy after lumpectomy. Patients eligible included those with T1-2, N0-1 ({<=}3 nodes positive), M0 tumors of nonlobular histology with negative surgical margins, no extracapsular nodal extension, and negative results on postexcision mammogram. All patients underwent surgical excision and postoperative irradiation with HDR interstitial brachytherapy. The planning target volume was defined as the excision cavity plus a 2-cm margin. Treatment was delivered with a high-activity Ir-192 source at 3.4 Gy per fraction twice daily for 5 days to a total dose of 34 Gy. Dosimetric analyses were performed with three-dimensional postimplant dose and volume reconstructions. All patients were evaluated at 3-6-month intervals and assessed with a standardized cosmetic rating scale and according to Radiation Therapy Oncology Group late normal tissue toxicity scoring criteria. Clinical and therapy-related features were analyzed for their relationship to cosmetic outcome and toxicity rating. Clinical features analyzed included age, volume of resection, history of diabetes or hypertension, extent of axillary surgery, and systemic therapies. Therapy-related features analyzed included volume of tissue encompassed by the 100%, 150%, and 200% isodose lines (V100, V150, and V200, respectively), the dose homogeneity index (DHI), number of source dwell positions, and planar separation. Results: The median follow-up of all patients was 73 months (range, 43-118 months). The cosmetic outcome at last follow-up was rated as excellent, good, and fair/poor in 67%, 24%, and 9% of patients, respectively

  6. High-Risk Prostate Cancer With Gleason Score 8-10 and PSA Level {<=}15 ng/ mL Treated With Permanent Interstitial Brachytherapy

    SciTech Connect

    Fang, L. Christine; Merrick, Gregory S.; Butler, Wayne M.; Galbreath, Robert W.; Murray, Brian C.; Reed, Joshua L.; Adamovich, Edward; Wallner, Kent E.

    2011-11-15

    Purpose: With widespread prostate-specific antigen (PSA) screening, there has been an increase in men diagnosed with high-risk prostate cancer defined by a Gleason score (GS) {>=}8 coupled with a relatively low PSA level. The optimal management of these patients has not been defined. Cause-specific survival (CSS), biochemical progression-free survival (bPFS), and overall survival (OS) were evaluated in brachytherapy patients with a GS {>=}8 and a PSA level {<=}15 ng/mL with or without androgen-deprivation therapy (ADT). Methods and Materials: From April 1995 to October 2005, 174 patients with GS {>=}8 and a PSA level {<=}15 ng/mL underwent permanent interstitial brachytherapy. Of the patients, 159 (91%) received supplemental external beam radiation, and 113 (64.9%) received ADT. The median follow-up was 6.6 years. The median postimplant Day 0 minimum percentage of the dose covering 90% of the target volume was 121.1% of prescription dose. Biochemical control was defined as a PSA level {<=}0.40 ng/mL after nadir. Multiple parameters were evaluated for impact on survival. Results: Ten-year outcomes for patients without and with ADT were 95.2% and 92.5%, respectively, for CSS (p = 0.562); 86.5% and 92.6%, respectively, for bPFS (p = 0.204); and 75.2% and 66.0%, respectively, for OS (p = 0.179). The median post-treatment PSA level for biochemically controlled patients was <0.02 ng/mL. Multivariate analysis failed to identify any predictors for CSS, whereas bPFS and OS were most closely related to patient age. Conclusions: Patients with GS {>=}8 and PSA level {<=}15 ng/mL have excellent bPFS and CSS after brachytherapy with supplemental external beam radiotherapy. The use of ADT did not significantly impact bPFS, CSS, or OS.

  7. Cosmetic Analysis Following Breast-Conserving Surgery and Adjuvant High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer: A Prospective Clinical Study

    SciTech Connect

    Garsa, Adam A.; Ferraro, Daniel J.; DeWees, Todd; Margenthaler, Julie A.; Naughton, Michael; Aft, Rebecca; Gillanders, William E.; Eberlein, Timothy; Matesa, Melissa A.; Zoberi, Imran

    2013-03-15

    Purpose: To prospectively evaluate cosmetic outcomes in women treated with accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy for early-stage breast cancer. Methods and Materials: Between 2004 and 2008, 151 patients with early-stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients had stage Tis-T2 tumors of ≤3 cm that were excised with negative margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. Both the patients and the treating radiation oncologist qualitatively rated cosmesis as excellent, good, fair, or poor over time and ascribed a cause for changes in cosmesis. Cosmetic outcome was evaluated quantitatively by percentage of breast retraction assessment (pBRA). Patients also reported their satisfaction with treatment over time. Results: Median follow-up was 55 months. The rates of excellent-to-good cosmesis reported by patients and the treating radiation oncologist were 92% and 97% pretreatment, 91% and 97% at 3 to 4 months' follow-up, 87% and 94% at 2 years, and 92% and 94% at 3 years, respectively. Breast infection and adjuvant chemotherapy were independent predictors of a fair-to-poor cosmetic outcome at 3 years. Compared to pretreatment pBRA (7.35), there was no significant change in pBRA over time. The volume receiving more than 150 Gy (V150) was the only significant predictor of pBRA. The majority of patients (86.6%) were completely satisfied with their treatment. Conclusions: Patients and the treating physician reported a high rate of excellent-to-good cosmetic outcomes at all follow-up time points. Acute breast infection and chemotherapy were associated with worse cosmetic outcomes. Multicatheter interstitial brachytherapy does not significantly change breast size as measured by pBRA.

  8. A Prospective Longitudinal Clinical Trial Evaluating Quality of Life After Breast-Conserving Surgery and High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer

    SciTech Connect

    Garsa, Adam A.; Ferraro, Daniel J.; DeWees, Todd A.; Deshields, Teresa L.; Margenthaler, Julie A.; Cyr, Amy E.; Naughton, Michael; Aft, Rebecca; Gillanders, William E.; Eberlein, Timothy; Matesa, Melissa A.; Ochoa, Laura L.; Zoberi, Imran

    2013-12-01

    Purpose: To prospectively examine quality of life (QOL) of patients with early stage breast cancer treated with accelerated partial breast irradiation (APBI) using high-dose-rate (HDR) interstitial brachytherapy. Methods and Materials: Between March 2004 and December 2008, 151 patients with early stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients included those with Tis-T2 tumors measuring ≤3 cm excised with negative surgical margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. QOL was measured using European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, version 3.0, and QLQ-BR23 questionnaires. The QLQ-C30 and QLQ-BR23 questionnaires were evaluated during pretreatment and then at 6 to 8 weeks, 3 to 4 months, 6 to 8 months, and 1 and 2 years after treatment. Results: The median follow-up was 55 months. Breast symptom scores remained stable in the months after treatment, and they significantly improved 6 to 8 months after treatment. Scores for emotional functioning, social functioning, and future perspective showed significant improvement 2 years after treatment. Symptomatic fat necrosis was associated with several changes in QOL, including increased pain, breast symptoms, systemic treatment side effects, dyspnea, and fatigue, as well as decreased role functioning, emotional functioning, and social functioning. Conclusions: HDR multicatheter interstitial brachytherapy was well tolerated, with no significant detrimental effect on measured QOL scales/items through 2 years of follow-up. Compared to pretreatment scores, there was improvement in breast symptoms, emotional functioning, social functioning, and future perspective 2 years after treatment.

  9. Dosimetric effect of tissue heterogeneity for 125I prostate implants

    PubMed Central

    Oliveira, Susana Maria; Teixeira, Nuno José; Fernandes, Lisete; Teles, Pedro; Vaz, Pedro

    2014-01-01

    Aim To use Monte Carlo (MC) together with voxel phantoms to analyze the tissue heterogeneity effect in the dose distributions and equivalent uniform dose (EUD) for 125I prostate implants. Background Dose distribution calculations in low dose-rate brachytherapy are based on the dose deposition around a single source in a water phantom. This formalism does not take into account tissue heterogeneities, interseed attenuation, or finite patient dimensions effects. Tissue composition is especially important due to the photoelectric effect. Materials and methods The computed tomographies (CT) of two patients with prostate cancer were used to create voxel phantoms for the MC simulations. An elemental composition and density were assigned to each structure. Densities of the prostate, vesicles, rectum and bladder were determined through the CT electronic densities of 100 patients. The same simulations were performed considering the same phantom as pure water. Results were compared via dose–volume histograms and EUD for the prostate and rectum. Results The mean absorbed doses presented deviations of 3.3–4.0% for the prostate and of 2.3–4.9% for the rectum, when comparing calculations in water with calculations in the heterogeneous phantom. In the calculations in water, the prostate D90 was overestimated by 2.8–3.9% and the rectum D0.1cc resulted in dose differences of 6–8%. The EUD resulted in an overestimation of 3.5–3.7% for the prostate and of 7.7–8.3% for the rectum. Conclusions The deposited dose was consistently overestimated for the simulation in water. In order to increase the accuracy in the determination of dose distributions, especially around the rectum, the introduction of the model-based algorithms is recommended. PMID:25337412

  10. Evaluation of the dose distribution for prostate implants using various {sup 125}I and {sup 103}Pd sources

    SciTech Connect

    Meigooni, Ali S.; Luerman, Christine M.; Sowards, Keith T.

    2009-04-15

    Recently, several different models of {sup 125}I and {sup 103}Pd brachytherapy sources have been introduced in order to meet the increasing demand for prostate seed implants. These sources have different internal structures; hence, their TG-43 dosimetric parameters are not the same. In this study, the effects of the dosimetric differences among the sources on their clinical applications were evaluated. The quantitative and qualitative evaluations were performed by comparisons of dose distributions and dose volume histograms of prostate implants calculated for various designs of {sup 125}I and {sup 103}Pd sources. These comparisons were made for an identical implant scheme with the same number of seeds for each source. The results were compared with the Amersham model 6711 seed for {sup 125}I and the Theragenics model 200 seed for {sup 103}Pd using the same implant scheme.

  11. Calculated dosimetric parameters of the IoGold 125I source model 3631-A.

    PubMed

    Wierzbicki, J G; Rivard, M J; Waid, D S; Arterbery, V E

    1998-11-01

    Basic dosimetric parameters as recommended by the AAPM Task Group No. 43 (TG-43) have been determined for recently available IoGold 125I brachytherapy seeds. Monte Carlo methods (MCNP) were used in the calculation of these parameters in water, and results compared with soon to be published experimental parameters also for 125I IoGold seeds as well with parameters for model 6702 and 6711 125I seeds. These parameters were the radial dose function, anisotropy factor and constant, and the dose rate constant. Using MCNP, values for the radial dose function at 0.5, 2.0, and 5.0 cm were 1.053, 0.877, and 0.443, respectively. The anisotropy factor was 0.975, 0.946, 0.945, and 0.952 at 0.5, 1.0, 2.0, and 5.0 cm, respectively, with an anisotropy constant of 0.95. The IoGold dose rate constant was determined by excluding the low energy titanium characteristic x rays produced in the IoGold titanium capsule. Using this post TG-43 revised NIST air kerma methodology, the IoGold dose rate constant was 0.96 cGy h-1 U-1. These calculatively determined parameters for IoGold seeds were compared with those determined experimentally for IoGold seeds, and also compared with parameters determined for model 6702 and 6711 seeds as presented in TG-43. PMID:9829245

  12. Computed Tomography-Guided Interstitial HDR Brachytherapy (CT-HDRBT) of the Liver in Patients with Irresectable Intrahepatic Cholangiocarcinoma

    SciTech Connect

    Schnapauff, Dirk Denecke, Timm; Grieser, Christian; Colletini, Federico; Seehofer, Daniel; Sinn, Marianne; Wust, Peter; Gebauer, Bernhard

    2012-06-15

    Purpose: This study was designed to investigate the clinical outcome of patients with irresectable, intrahepatic cholangiocarcinoma (IHC) treated with computed tomography (CT)-guided HDR-brachytherapy (CT-HDRBT) for local tumor ablation.MethodFifteen consecutive patients with histologically proven cholangiocarcinoma were selected for this retrospective study. Patients were treated by high-dose-rate internal brachytherapy (HDRBT) using an Iridium-192 source in afterloading technique through CT-guided percutaneous placed catheters. A total of 27 brachytherapy treatments were performed in these patients between 2006 and 2009. Median tumor enclosing target dose was 20 Gy, and mean target volume of the radiated tumors was 131 ({+-} 90) ml (range, 10-257 ml). Follow-up consisted of clinical visits and magnetic resonance imaging of the liver every third month. Statistical evaluation included survival analysis using the Kaplan-Meier method. Results: After a median follow-up of 18 (range, 1-27) months after local ablation, 6 of the 15 patients are still alive; 4 of them did not get further chemotherapy and are regarded as disease-free. The reached median local tumor control was 10 months; median local tumor control, including repetitive local ablation, was 11 months. Median survival after local ablation was 14 months and after primary diagnosis 21 months. Conclusion: In view of current clinical data on the clinical outcome of cholangiocarcinoma, locally ablative treatment with CT-HDRBT represents a promising and safe technique for patients who are not eligible for tumor resection.

  13. Fragmentation of chromatin with 125I radioactive disintegrations.

    PubMed Central

    Turner, G N; Nobis, P; Dewey, W C

    1976-01-01

    The DNA in Chinese hamster cells was labeled first for 3 h with [3H]TdR and then for 3 h with [125I]UdR. Chromatin was extracted, frozen, and stored at -30 degrees C until 1.0 X 10(17) and 1.25 X 10(17) disintegrations/g of labeled DNA occurred for 125I and 3H respectively. Velocity sedimentation of chromatin (DNA with associated chromosomal proteins) in neutral sucrose gradients indicated that the localized energy from the 125I disintegrations, which gave about 1 double-strand break/disintegration plus an additional 1.3 single strand breaks, selectively fragmented the [125I] chromatin into pieces smaller than the [3H] chromatin. In other words, 125I disintegrations caused much more localized damage in the chromatin labeled with 125I than in the chromatin labeled with 3H, and fragments induced in DNA by 125I disintegrations were not held together by the associated chromosomal proteins. Use of this 125I technique for studying chromosomal proteins associated with different regions in the cellular DNA is discussed. For these studies, the number of disintegrations required for fragmenting DNA molecules of different sizes is illustrated. PMID:963201

  14. Is there a subset of patients with recurrent cancer in the vagina who are not candidates for interstitial brachytherapy that can be treated with multichannel vaginal brachytherapy using graphic optimization?

    PubMed Central

    Bylund, Kevin C.; Matloubieh, Ahmad; Mazloom, Ali; Gray, Alexander; Sidhu, Ravinder; Barrette, Lucille; Chen, Yuhchyau

    2015-01-01

    Purpose To evaluate recurrent vaginal cancer treated with vaginal brachytherapy (VBT) using graphic optimization in patients not amenable to surgery and interstitial brachytherapy (ISBT). Material and methods We retrospectively reviewed the records of 5 patients with recurrent cancer in the vagina that were deemed not to be good candidates for ISBT implant because of medical reasons. All patients received computed tomography/magnetic resonance imaging (CT/MRI) based evaluation in addition to a detailed clinical examination, and were noted to have recurrent nodules in the vagina with size ranging from 10-25 mm. Four of the 5 patients had recurrent disease in the vaginal apex, whereas one patient had recurrence in the lateral vaginal wall. Subsequently, all patients were treated with external beam radiation therapy (EBRT) followed by multichannel vaginal cylinder (MVC)-based VBT using graphic optimization for shaping the isodose to improve the clinical target volume (CTV) coverage, as well as to spare the organs at risk (OAR). The dose to the bladder and rectum with regard to 0.1 cc, 1 cc, and 2 cc were recorded. Results Median age of the patients was 78 years (range 58-86 years). Thickness of the lesions before VBT ranged from 6-15 mm. All patients were followed up with MRI at 3 months. All patients but one demonstrated complete clinical/ radiological response of the tumor. No patient had any grade III/IV toxicity at 24 months. Conclusions MVC-based VBT using graphic optimization is safe and yields favorable results if used judiciously. PMID:26034494

  15. Multi-catheter interstitial brachytherapy for partial breast irradiation: an audit of implant quality based on dosimetric evaluation comparing intra-operative versus post-operative placement

    PubMed Central

    Gurram, Lavanya; Joshi, Kishor; Phurailatpam, Reena; Paul, Siji; Sarin, Rajiv

    2016-01-01

    Purpose The use of multicatheter interstitial brachytherapy (MIB) for accelerated partial breast irradiation (APBI) in early breast cancer (EBC) patients outside the trial setting has increased. Hence, there is a need to critically evaluate implant quality. Moreover, there is a scarcity of reports using an open cavity technique. We report the dosimetric indices of open and closed cavity MIB techniques. Material and methods The dosimetric parameters of 60 EBC patients treated with MIB (open and closed cavity) who underwent three dimensional, computerized tomography (CT) based planning for APBI from November 2011 to July 2015 were evaluated. Coverage Index (CI), Dose Homogeneity Index (DHI), Conformity Index (COIN), Plan Quality Index (PQI), and Dose Non-uniformity Index (DNR) were assessed. Results Forty-one patients underwent open cavity and 19 patients underwent closed cavity placement of brachytherapy catheters. The median number of planes was 4 and median number of needles was 20. Median dose was 34 Gy with dose per fraction of 3.4 Gy, given twice a day, 6 hours apart. The D90 of the cavity and clinical target volume (CTV) were 105% and 89%, respectively. The median doses to the surgical clips were greater than 100%. The median CI of the cavity and CTV was 0.96 and 0.82, respectively. The DHI and COIN index of the CTV was 0.73 and 0.67. There were no significant differences in the dosimetric parameters based on whether the technique was done open or closed. Conclusions Critical evaluation of the dosimetric parameters of MIB-APBI is important for optimal results. While the open and closed techniques have similar dosimetry, our institutional preference is for an open technique which eases the procedure due to direct visualization of the tumor cavity. PMID:27257415

  16. A Dose-Volume Analysis of Magnetic Resonance Imaging-Aided High-Dose-Rate Image-Based Interstitial Brachytherapy for Uterine Cervical Cancer

    SciTech Connect

    Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

    2010-07-01

    Purpose: To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Methods and Materials: Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD{sub 2}). Results: The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D{sub 2cc} of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Conclusions: Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results.

  17. Validation of mathematical models for the prediction of organs-at-risk dosimetric metrics in high-dose-rate gynecologic interstitial brachytherapy

    SciTech Connect

    Damato, Antonio L.; Viswanathan, Akila N.; Cormack, Robert A.

    2013-10-15

    Purpose: Given the complicated nature of an interstitial gynecologic brachytherapy treatment plan, the use of a quantitative tool to evaluate the quality of the achieved metrics compared to clinical practice would be advantageous. For this purpose, predictive mathematical models to predict the D{sub 2cc} of rectum and bladder in interstitial gynecologic brachytherapy are discussed and validated.Methods: Previous plans were used to establish the relationship between D2cc and the overlapping volume of the organ at risk with the targeted area (C0) or a 1-cm expansion of the target area (C1). Three mathematical models were evaluated: D{sub 2cc}=α*C{sub 1}+β (LIN); D{sub 2cc}=α– exp(–β*C{sub 0}) (EXP); and a mixed approach (MIX), where both C{sub 0} and C{sub 1} were inputs of the model. The parameters of the models were optimized on a training set of patient data, and the predictive error of each model (predicted D{sub 2cc}− real D{sub 2cc}) was calculated on a validation set of patient data. The data of 20 patients were used to perform a K-fold cross validation analysis, with K = 2, 4, 6, 8, 10, and 20.Results: MIX was associated with the smallest mean prediction error <6.4% for an 18-patient training set; LIN had an error <8.5%; EXP had an error <8.3%. Best case scenario analysis shows that an error ≤5% can be achieved for a ten-patient training set with MIX, an error ≤7.4% for LIN, and an error ≤6.9% for EXP. The error decreases with the increase in training set size, with the most marked decrease observed for MIX.Conclusions: The MIX model can predict the D{sub 2cc} of the organs at risk with an error lower than 5% with a training set of ten patients or greater. The model can be used in the development of quality assurance tools to identify treatment plans with suboptimal sparing of the organs at risk. It can also be used to improve preplanning and in the development of real-time intraoperative planning tools.

  18. Clinical results of early stage prostatic cancer treated by pelvic lymphadenectomy and /sup 125/I implants

    SciTech Connect

    Kandzari, S.J.; Belis, J.A.; Kim, J.C.; Gnepp, D.R.; Riley, R.S.

    1982-05-01

    Eighty patients with clinically early stage adenocarcinoma of the prostate were treated with pelvic lymphadenectomy and interstitial implantation of /sup 125/I seeds. A new applicator that permits greater accuracy in spacing the seeds has been developed. Postoperative complications were minimal, with urinary irritability being the most common. Multiple transrectal needle biopsies were performed 12 and 18 months after treatment in 46 patients. The prostatic biopsies were negative for carcinoma in 61 per cent and positive in 39 per cent of the patients. Long-term followup is needed to correlate post-treatment biopsies with survival and to determine if patients with positive biopsies should receive further treatment.

  19. Validation of a novel robot-assisted 3DUS system for real-time planning and guidance of breast interstitial HDR brachytherapy

    SciTech Connect

    Poulin, Eric; Beaulieu, Luc; Gardi, Lori; Barker, Kevin; Montreuil, Jacques; Fenster, Aaron

    2015-12-15

    Purpose: In current clinical practice, there is no integrated 3D ultrasound (3DUS) guidance system clinically available for breast brachytherapy. In this study, the authors present a novel robot-assisted 3DUS system for real-time planning and guidance of breast interstitial high dose rate (HDR) brachytherapy treatment. Methods: For this work, a new computer controlled robotic 3DUS system was built to perform a hybrid motion scan, which is a combination of a 6 cm linear translation with a 30° rotation at both ends. The new 3DUS scanner was designed to fit on a modified Kuske assembly, keeping the current template grid configuration but modifying the frame to allow the mounting of the 3DUS system at several positions. A finer grid was also tested. A user interface was developed to perform image reconstruction, semiautomatic segmentation of the surgical bed as well as catheter reconstruction and tracking. A 3D string phantom was used to validate the geometric accuracy of the reconstruction. The volumetric accuracy of the system was validated with phantoms using magnetic resonance imaging (MRI) and computed tomography (CT) images. In order to accurately determine whether 3DUS can effectively replace CT for treatment planning, the authors have compared the 3DUS catheter reconstruction to the one obtained from CT images. In addition, in agarose-based phantoms, an end-to-end procedure was performed by executing six independent complete procedures with both 14 and 16 catheters, and for both standard and finer Kuske grids. Finally, in phantoms, five end-to-end procedures were performed with the final CT planning for the validation of 3DUS preplanning. Results: The 3DUS acquisition time is approximately 10 s. A paired Student t-test showed that there was no statistical significant difference between known and measured values of string separations in each direction. Both MRI and CT volume measurements were not statistically different from 3DUS volume (Student t-test: p > 0

  20. AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137

    PubMed Central

    Nath, Ravinder; Bice, William S.; Butler, Wayne M.; Chen, Zhe; Meigooni, Ali S.; Narayana, Vrinda; Rivard, Mark J.; Yu, Yan

    2009-01-01

    During the past decade, permanent radioactive source implantation of the prostate has become the standard of care for selected prostate cancer patients, and the techniques for implantation have evolved in many different forms. Although most implants use 125I or 103Pd sources, clinical use of 131Cs sources has also recently been introduced. These sources produce different dose distributions and irradiate the tumors at different dose rates. Ultrasound was used originally to guide the planning and implantation of sources in the tumor. More recently, CT and∕or MR are used routinely in many clinics for dose evaluation and planning. Several investigators reported that the tumor volumes and target volumes delineated from ultrasound, CT, and MR can vary substantially because of the inherent differences in these imaging modalities. It has also been reported that these volumes depend critically on the time of imaging after the implant. Many clinics, in particular those using intraoperative implantation, perform imaging only on the day of the implant. Because the effects of edema caused by surgical trauma can vary from one patient to another and resolve at different rates, the timing of imaging for dosimetry evaluation can have a profound effect on the dose reported (to have been delivered), i.e., for the same implant (same dose delivered), CT at different timing can yield different doses reported. Also, many different loading patterns and margins around the tumor volumes have been used, and these may lead to variations in the dose delivered. In this report, the current literature on these issues is reviewed, and the impact of these issues on the radiobiological response is estimated. The radiobiological models for the biological equivalent dose (BED) are reviewed. Starting with the BED model for acute single doses, the models for fractionated doses, continuous low-dose-rate irradiation, and both homogeneous and inhomogeneous dose distributions, as well as tumor cure

  1. AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137

    SciTech Connect

    Nath, Ravinder; Bice, William S.; Butler, Wayne M.; Chen Zhe; Meigooni, Ali S.; Narayana, Vrinda; Rivard, Mark J.; Yu Yan

    2009-11-15

    During the past decade, permanent radioactive source implantation of the prostate has become the standard of care for selected prostate cancer patients, and the techniques for implantation have evolved in many different forms. Although most implants use {sup 125}I or {sup 103}Pd sources, clinical use of {sup 131}Cs sources has also recently been introduced. These sources produce different dose distributions and irradiate the tumors at different dose rates. Ultrasound was used originally to guide the planning and implantation of sources in the tumor. More recently, CT and/or MR are used routinely in many clinics for dose evaluation and planning. Several investigators reported that the tumor volumes and target volumes delineated from ultrasound, CT, and MR can vary substantially because of the inherent differences in these imaging modalities. It has also been reported that these volumes depend critically on the time of imaging after the implant. Many clinics, in particular those using intraoperative implantation, perform imaging only on the day of the implant. Because the effects of edema caused by surgical trauma can vary from one patient to another and resolve at different rates, the timing of imaging for dosimetry evaluation can have a profound effect on the dose reported (to have been delivered), i.e., for the same implant (same dose delivered), CT at different timing can yield different doses reported. Also, many different loading patterns and margins around the tumor volumes have been used, and these may lead to variations in the dose delivered. In this report, the current literature on these issues is reviewed, and the impact of these issues on the radiobiological response is estimated. The radiobiological models for the biological equivalent dose (BED) are reviewed. Starting with the BED model for acute single doses, the models for fractionated doses, continuous low-dose-rate irradiation, and both homogeneous and inhomogeneous dose distributions, as well as

  2. Interstitial microwave hyperthermia and brachytherapy for malignancies of the vulva and vagina. I: Design and testing of a modified intracavitary obturator.

    PubMed

    Ryan, T P; Taylor, J H; Coughlin, C T

    1992-01-01

    A vaginal obturator was fabricated to be used in combination with implanted catheters to provide microwave hyperthermia and brachytherapy to the vulva and vaginal wall. This site is difficult to heat or irradiate solely with interstitial techniques. The obturator was modified to provide grooves for the mounting of interstitial catheters into the outer wall and was matched with a template for circumferential implants. Power deposition tests were done using arrays of three microwave antenna designs: dipole (hA = hB = 3.9 cm), helical (3.9 cm coil, shorted), and modified dipole (1.0 cm helix on dipole tip) to test the performance of the obturator. The obturator and four non-obturator catheters were positioned in muscle-equivalent phantom. Two obturator catheters along with two free-standing catheters formed the obturator array. Four freestanding catheters formed the non-obturator array. Power deposition or specific absorption rate (SAR) measurements were made along the central axis, bisect, and diagonal transect of each array. SAR results showed that antennas in the obturator wall radiated as dipole theory predicts, although with less power density when compared to antennas in the same catheters spaced 1.8 cm from the obturator. This could be compensated for by increasing the power to the antennas in the obturator by 42%. Adjacent pairs of antennas were placed 90 degrees out of phase for 0.25 sec and rotated around the array. Phase rotation demonstrated that the central array SAR peaks could be lowered from 100% to 50% SAR, with dipole antennas thus resulting in lowered peak temperatures and the ability to heat larger volumes by improving the distribution of power. With helical antennas, there was 50% SAR at the array center when operated coherently without phase rotation. Three patients were treated with the obturator and a custom-made template using dipole antennas, and temperatures were measured in five obturator catheters. Therapeutic heating was measured in the

  3. A Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy, Three-Dimensional Conformal Radiotherapy, and Supine Versus Prone Helical Tomotherapy

    SciTech Connect

    Patel, Rakesh R. . E-mail: patel@humonc.wisc.edu; Becker, Stewart J.; Das, Rupak K.; Mackie, Thomas R.

    2007-07-01

    Purpose: To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient. Methods and Materials: Thirteen post-lumpectomy interstitial brachytherapy (IB) patients underwent imaging with preimplant computed tomography (CT) in the prone and supine position. These CT scans were then used to generate three-dimensional conformal radiotherapy (3D-CRT) and prone and supine helical tomotherapy (PT and ST, respectively) APBI plans and compared with the treated IB plans. Dose-volume histogram analysis and the mean dose (NTD{sub mean}) values were compared. Results: Planning target volume coverage was excellent for all methods. Statistical significance was considered to be a p value <0.05. The mean V100 was significantly lower for IB (12% vs. 15% for PT, 18% for ST, and 26% for 3D-CRT). A greater significant differential was seen when comparing V50 with mean values of 24%, 43%, 47%, and 52% for IB, PT, ST, and 3D-CRT, respectively. The IB and PT were similar and delivered an average lung NTD{sub mean} dose of 1.3 Gy{sub 3} and 1.2 Gy{sub 3}, respectively. Both of these methods were statistically significantly lower than the supine external beam techniques. Overall, all four methods yielded similar low doses to the heart. Conclusions: The use of IB and PT resulted in greater normal tissue sparing (especially ipsilateral breast and lung) than the use of supine external beam techniques of 3D-CRT or ST. However, the choice of APBI technique must be tailored to the patient's anatomy, lumpectomy cavity location, and overall treatment goals.

  4. Carbon cartridge standards for 125I and suggested applications.

    PubMed

    Tries, M A; Ring, J P; Chabot, G E

    1997-09-01

    Carbon cartridge standards were prepared to assess the activity of 125I incident on, and adsorbed in, cartridge samples during air sampling. Each cartridge standard consisted of an 125I-spiked filter paper at a known depth, ranging from 0 to 19 mm, embedded in approximately 34 g of 20-30 mesh activated carbon contained within a 6.35 cm diameter by 2.22 cm deep metal cartridge with screened openings. The total counting efficiency values range from 17.8 to 20.8% for cartridges counted at 3.2 mm from a thin-crystal NaI(Tl) detector. The standards were analyzed using a front/back counting technique, and fitting functions were developed relating the front/back net counts ratio and counting efficiency to the 125I depth of burial. A method for determining sample activity that accounts for exponential radioiodine loading in cartridge samples is compared to a less complicated technique that assumes all the radioiodine is located at an equivalent depth of burial that is based on the sample front/back net counts ratio. In addition, methods are presented for determining airborne 125I activity for constant and variable concentrations. Variable concentrations are assumed to occur in a fume hood duct by one or more bulk releases as a result of iodinations that are performed during a given sampling interval. The two methods are shown to have maximum relative deviations ranging from -16 to +16%. PMID:9287093

  5. Scintillation Proximity Radioimmunoassay Utilizing 125I-Labeled Ligands

    NASA Astrophysics Data System (ADS)

    Udenfriend, Sidney; Diekmann Gerber, Louise; Brink, Larry; Spector, Sydney

    1985-12-01

    A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an 125I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the 125I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.

  6. Scintillation proximity radioimmunoassay utilizing 125I-labeled ligands

    SciTech Connect

    Udenfriend, S.; Gerber, L.D.; Brink, L.; Spector, S.

    1985-12-01

    A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an /sup 125/I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the /sup 125/I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.

  7. The effect of lead, gold, and silver backings on dose near 125I seeds.

    PubMed

    Meli, J A; Motakabbir, K A

    1993-01-01

    Brachytherapy for ocular melanoma uses 125I seeds backed by a gold shield. Conflicting results are reported in the literature on the effect of the gold on dose close to the seeds. In this work, a small lucite jig was constructed such that the seed-to-detector separation remained fixed as high-Z materials of lead, silver, and gold were moved in and out of position behind the seed. The jig was clamped in place in the water filled tank of a beam scanning system. The response of two p-type silicon diodes was measured at several distances from the seed with and without the high-Z backings. The response with the high-Z backing relative to water, found to be the same for each diode and the same for lead and gold, decreased from about 1.01 at 1.5 mm to about 0.92 at 20 mm. It has been suggested in the literature that L-shell fluorescent x rays of approximately 10 keV from the gold backing might contribute significantly to the dose within 7 mm of the seed. To test this, the response with the gold backing relative to water was measured with an aluminum cap of 1-mm wall thickness covering the diode. The cap transmits about 70% of the 125I influence but is essentially infinitely thick to 10-keV photons. The relative response (gold/water) was the same with and without the cap showing that the contribution of 10-keV x rays is negligible. Compared to water, the silver backing was found to enhance the diode response by about 14% between 5 to 10 mm from the seed. PMID:8413037

  8. Design and synthesis of [(125)I]Pyricoxib: A novel (125)I-labeled cyclooxygenase-2 (COX-2) inhibitors.

    PubMed

    Tietz, Ole; Dzandzi, James; Bhardwaj, Atul; Valliant, John F; Wuest, Frank

    2016-03-15

    Cyclooxygenase-2 (COX-2) is the key enzyme in the prostaglandin synthesis pathway which is involved in various pathophysiological conditions. The enzyme is membrane bound and located inside of the endoplasmic reticulum and nuclear membrane. Effective perfusion of inhibitors to the active site requires lipophilic drugs, which consequently display high unspecific background accumulation, for example, in fatty tissues. The objective of this work was the development of a small molecule radiolabeled with a long-lived iodine radioisotope to enable longer imaging times and better target-to-background ratios. A group of iodinated compounds (8-10) was synthesized and identified as selective COX-2 inhibitors (COX-2 IC50=0.85-13 μM). Molecular docking results provided the theoretical support for the experimental COX-2 inhibition data. Furthermore, a novel (125)I-containing trifluoro-pyrimidine compound ([(125)I]Pyricoxib) was prepared via radioiododestannylation reaction as potent and selective COX-2 inhibitor. Radiosynthesis of [(125)I]Pyricoxib was accomplished with innovative fluorous chemistry using fluorous chloroamine-T (F-CAT) as novel oxidizing agent in high radiochemical yields of 91 ± 4%. PMID:26898334

  9. WE-A-17A-06: Evaluation of An Automatic Interstitial Catheter Digitization Algorithm That Reduces Treatment Planning Time and Provide Means for Adaptive Re-Planning in HDR Brachytherapy of Gynecologic Cancers

    SciTech Connect

    Dise, J; Liang, X; Lin, L; Teo, B

    2014-06-15

    Purpose: To evaluate an automatic interstitial catheter digitization algorithm that reduces treatment planning time and provide means for adaptive re-planning in HDR Brachytherapy of Gynecologic Cancers. Methods: The semi-automatic catheter digitization tool utilizes a region growing algorithm in conjunction with a spline model of the catheters. The CT images were first pre-processed to enhance the contrast between the catheters and soft tissue. Several seed locations were selected in each catheter for the region growing algorithm. The spline model of the catheters assisted in the region growing by preventing inter-catheter cross-over caused by air or metal artifacts. Source dwell positions from day one CT scans were applied to subsequent CTs and forward calculated using the automatically digitized catheter positions. This method was applied to 10 patients who had received HDR interstitial brachytherapy on an IRB approved image-guided radiation therapy protocol. The prescribed dose was 18.75 or 20 Gy delivered in 5 fractions, twice daily, over 3 consecutive days. Dosimetric comparisons were made between automatic and manual digitization on day two CTs. Results: The region growing algorithm, assisted by the spline model of the catheters, was able to digitize all catheters. The difference between automatic and manually digitized positions was 0.8±0.3 mm. The digitization time ranged from 34 minutes to 43 minutes with a mean digitization time of 37 minutes. The bulk of the time was spent on manual selection of initial seed positions and spline parameter adjustments. There was no significance difference in dosimetric parameters between the automatic and manually digitized plans. D90% to the CTV was 91.5±4.4% for the manual digitization versus 91.4±4.4% for the automatic digitization (p=0.56). Conclusion: A region growing algorithm was developed to semi-automatically digitize interstitial catheters in HDR brachytherapy using the Syed-Neblett template. This automatic

  10. Computed Tomography–Guided Interstitial High-Dose-Rate Brachytherapy in Combination With Regional Positive Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non–Small Cell Lung Cancer: A Phase 1 Clinical Trial

    SciTech Connect

    Xiang, Li; Zhang, Jian-wen; Lin, Sheng; Luo, Hui-Qun; Wen, Qing-Lian; He, Li-Jia; Shang, Chang-Ling; Ren, Pei-Rong; Yang, Hong-Ru; Pang, Hao-Wen; Yang, Bo; He, Huai-Lin; Chen, Yue; Wu, Jing-Bo

    2015-08-01

    Purpose: To assess the technical safety, adverse events, and efficacy of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity modulated radiation therapy in patients with locally advanced peripheral non–small cell lung cancer (NSCLC). Methods and Materials: Twenty-six patients with histologically confirmed NSCLC were enrolled in a prospective, officially approved phase 1 trial. Primary tumors were treated with HDR brachytherapy. A single 30-Gy dose was delivered to the 90% isodose line of the gross lung tumor volume. A total dose of at least 70 Gy was administered to the 95% isodose line of the planning target volume of malignant lymph nodes using 6-MV X-rays. The patients received concurrent or sequential chemotherapy. We assessed treatment efficacy, adverse events, and radiation toxicity. Results: The median follow-up time was 28 months (range, 7-44 months). There were 3 cases of mild pneumothorax but no cases of hemothorax, dyspnea, or pyothorax after the procedure. Grade 3 or 4 acute hematologic toxicity was observed in 5 patients. During follow-up, mild fibrosis around the puncture point was observed on the CT scans of 2 patients, but both patients were asymptomatic. The overall response rates (complete and partial) for the primary mass and positive lymph nodes were 100% and 92.3%, respectively. The 1-year and 2-year overall survival (OS) rates were 90.9% and 67%, respectively, with a median OS of 22.5 months. Conclusion: Our findings suggest that HDR brachytherapy is safe and feasible for peripheral locally advanced NSCLC, justifying a phase 2 clinical trial.

  11. Objective and Longitudinal Assessment of Dermatitis After Postoperative Accelerated Partial Breast Irradiation Using High-Dose-Rate Interstitial Brachytherapy in Patients With Breast Cancer Treated With Breast Conserving Therapy: Reduction of Moisture Deterioration by APBI

    SciTech Connect

    Tanaka, Eiichi; Yamazaki, Hideya; Yoshida, Ken; Takenaka, Tadashi; Masuda, Norikazu; Kotsuma, Tadayuki; Yoshioka, Yasuo; Inoue, Takehiro

    2011-11-15

    Purpose: To objectively evaluate the radiation dermatitis caused by accelerated partial breast irradiation (APBI) using high-dose-rate interstitial brachytherapy. Patients and Methods: The skin color and moisture changes were examined using a newly installed spectrophotometer and corneometer in 22 patients who had undergone APBI using open cavity implant high-dose-rate interstitial brachytherapy (36 Gy in six fractions) and compared with the corresponding values for 44 patients in an external beam radiotherapy (EBRT) control group (50-60 Gy in 25-30 fractions within 5-6 weeks) after breast conserving surgery. Results: All values changed significantly as a result of APBI. The extent of elevation in a Asterisk-Operator (reddish) and reduction in L Asterisk-Operator (black) values caused by APBI were similar to those for EBRT, with slightly delayed recovery for 6-12 months after treatment owing to the surgical procedure. In contrast, only APBI caused a change in the b Asterisk-Operator values, and EBRT did not, demonstrating that the reduction in b Asterisk-Operator values (yellowish) depends largely on the surgical procedure. The changes in moisture were less severe after APBI than after EBRT, and the recovery was more rapid. The toxicity assessment using the Common Toxicity Criteria, version 3, showed that all dermatitis caused by APBI was Grade 2 or less. Conclusion: An objective analysis can quantify the effects of APBI procedures on color and moisture cosmesis. The radiation dermatitis caused by APBI using the present schedule showed an equivalent effect on skin color and a less severe effect on moisture than the effects caused by standard EBRT.

  12. In Vivo Dosimetry of High-Dose-Rate Interstitial Brachytherapy in the Pelvic Region: Use of a Radiophotoluminescence Glass Dosimeter for Measurement of 1004 Points in 66 Patients With Pelvic Malignancy

    SciTech Connect

    Nose, Takayuki Koizumi, Masahiko; Yoshida, Ken; Nishiyama, Kinji; Sasaki, Junichi; Ohnishi, Takeshi; Kozuka, Takuyo; Gomi, Kotaro; Oguchi, Masahiko; Sumida, Iori; Takahashi, Yutaka; Ito, Akira; Yamashita, Takashi

    2008-02-01

    Purpose: To perform the largest in vivo dosimetry study for interstitial brachytherapy yet to be undertaken using a new radiophotoluminescence glass dosimeter (RPLGD) in patients with pelvic malignancy and to study the limits of contemporary planning software based on the results. Patients and Methods: Sixty-six patients with pelvic malignancy were treated with high-dose-rate interstitial brachytherapy, including prostate (n = 26), gynecological (n = 35), and miscellaneous (n = 5). Doses for a total of 1004 points were measured by RPLGDs and calculated with planning software in the following locations: rectum (n = 549), urethra (n = 415), vagina (n = 25), and perineum (n = 15). Compatibility (measured dose/calculated dose) was analyzed according to dosimeter location. Results: The compatibility for all dosimeters was 0.98 {+-} 0.23, stratified by location: rectum, 0.99 {+-} 0.20; urethra, 0.96 {+-} 0.26; vagina, 0.91 {+-} 0.08; and perineum, 1.25 {+-} 0.32. Conclusions: Deviations between measured and calculated doses for the rectum and urethra were greater than 20%, which is attributable to the independent movements of these organs and the applicators. Missing corrections for inhomogeneity are responsible for the 9% negative shift near the vaginal cylinder (specific gravity = 1.24), whereas neglect of transit dose contributes to the 25% positive shift in the perineal dose. Dose deviation of >20% for nontarget organs should be taken into account in the planning process. Further development of planning software and a real-time dosimetry system are necessary to use the current findings and to achieve adaptive dose delivery.

  13. Secondary sarcoma of bone post-prostate brachytherapy: A case report

    PubMed Central

    Ye, Allison Y.; Conway, Jessica; Peacock, Michael; Clarkson, Paul W.; Lee, Cheng-Han; Simmons, Christine; Weir, Lorna; McKenzie, Michael

    2014-01-01

    Malignancies associated with brachytherapy for prostate cancer are largely unreported in the literature. We report a case of post-brachytherapy osteogenic sarcoma in the pelvis 6 years after permanent 125I implant for intermediate-risk prostate cancer. The patient was treated with neoadjuvant chemotherapy, limb-sparing surgical resection and postoperative radiation therapy for unexpected positive margins. PMID:25024811

  14. Binding and internalization in vivo of (/sup 125/I)hCG in Leydig cells of the rat

    SciTech Connect

    Hermo, L.; Lalli, M.

    1988-01-01

    The present study was performed to demonstrate the binding, mode of uptake, pathway and fate of iodinated human chorionic gonadotropin ((/sup 125/I)hCG) by Leydig cells in vivo using electron microscope radioautography. Following a single injection of (/sup 125/I)hCG into the interstitial space of the testis, the animals were fixed by perfusion with glutaraldehyde at 20 minutes, 1, 3, 6 and 24 hours. The electron microscope radioautographs demonstrated a prominent and qualitatively similar binding of the labeled hCG on the microvillar processes of the Leydig cells at 20 minutes, 1, 3, and 6 hours. The specificity of the (/sup 125/I)hCG binding was determined by injecting a 100-fold excess of unlabeled hormone concurrently with the labeled hormone. Under these conditions, the surface, including the microvillar processes of Leydig cells, was virtually unlabeled, indicating that the binding was specific and receptor-mediated. In animals injected with labeled hCG and sacrificed 20 minutes later, silver grains were also seen overlying the limiting membrane of large, uncoated surface invaginations and large subsurface vacuoles with an electron-lucent content referred to as endosomes. A radioautographic reaction was also seen within multivesicular bodies with a pale stained matrix. At 1 hour, silver grains appeared over dense multivesicular bodies and occasionally over secondary lysosomes, in addition to the structures mentioned above, while at 3 and 6 hours, an increasing number of secondary lysosomes became labeled. At 24 hours, binding of (/sup 125/I)hCG to the microvillar processes of Leydig cells persisted but was diminished, although a few endosomes, multivesicular bodies and secondary lysosomes still showed a radioautographic reaction. No membranous tubules that were seen in close proximity to, or in continuity with, endosomes and multivesicular bodies were observed to be labeled at any time interval.

  15. {sup 125}I Measurements for Occupational Exposure Assessment

    SciTech Connect

    Silva, L.; Pinhao, N. R.

    2008-08-14

    Whenever there is a risk of occupational exposure to dispersible radioactive material, it is necessary to have a monitoring program to assess the effective dose arising from the intake of radionuclides by workers. In this paper we present our experience in bioassay measurements of {sup 125}I in urine samples of workers using high resolution gamma spectrometry. For a 24-hour excretion period, we found activity values of the order of one Bq and estimated the committed effective doses to be less than one {mu}Sv. Although very small, these values led to a re-evaluation and improvement of the laboratory safety conditions. We discuss the calibration procedure followed for the activity measurements, the estimation of the uncertainty in the excreted activity, the calculation of detection and quantification limits and estimation of performance indicators. Aspects regarding the spectral analysis, true coincidence summing and matrix effects are also considered.

  16. Synthesis and bioevaluation of 125I-labeled gold nanorods

    NASA Astrophysics Data System (ADS)

    Shao, Xia; Agarwal, Ashish; Rajian, Justin R.; Kotov, Nicholas A.; Wang, Xueding

    2011-04-01

    A novel technique is described for monitoring the in vivo behavior of gold nanorods (GNRs) using γ-imaging. GNRs were radiolabeled using [125I] sodium iodide in a simple and fast manner with high yield and without disturbing their optical properties. Radiolabeled GNRs were successfully visualized by radioisotope tagging, allowing longitudinal in vivo studies to be performed repeatedly in the same animal. The preliminary biodistribution study showed that PEGylated GNRs have much longer blood circulation times and clear out faster, while bare GNRs accumulate quickly in the liver after systematic administration. The highly efficient method reported here provides an extensively useful tool for guidance of the design and development of new gold nanoparticles as target-specific agents for both diagnostics and photothermal therapy.

  17. /sup 125/I iothalamate an ideal marker for glomerular filtration

    SciTech Connect

    Odlind, B.; Haellgren, R.S.; Sohtell, M.; Lindstroem, B.

    1985-01-01

    The triiodinated angiographic contrast medium, iothalamate (usually labelled /sup 125/I), has been used extensively as a marker for glomerular filtration. The authors have studied the renal handling of /sup 125/I iothalamate (IOT) in vivo and in vitro in several species. In renal cortical slices from chicken, rabbit, rat, and monkey, the tissue-to-medium ratio of IOT was twice that of /sup 51/Cr-EDTA (EDTA) at 37 degrees C; a difference that was abolished at 0 degree C and markedly reduced by added o-iodohippurate or iodipamide. In five chickens the steady-state renal clearance of IOT (CIOT) was twice that of EDTA (CEDTA) or /sup 3/H inulin (C1); a difference that was abolished by administration of 100 mg/kg/hr of novobiocin, an organic anion transport inhibitor. CEDTA was similar to C1 before as well as after transport inhibition. Utilizing the Sperber technique the mean apparent tubular excretion fraction (ATEF) of IOT was 8%, while that of EDTA was 1%. After novobiocin coinfusion (new steady-state) ATEFIOT was significantly reduced and not different from that of EDTA (-1%). In the same animals the total urinary recovery of IOT was 84 and 57% before and after novobiocin, respectively, while corresponding values for EDTA was unchanged by the inhibitor. In seven rats the renal extraction of IOT was reduced from 29 to 17% by coinfusion of probenecid (5 mg/kg/hr). Corresponding extractions were 82 to 34% and 22% (unchanged) for PAH and EDTA, respectively.

  18. Assessment of brain muscarinic acetylcholinergic receptors in living mice using a simple probe, [125I]-4-iododexetimide and [125I]-4-iodolevetimide.

    PubMed

    Sasaki, M; Müller-Gärtner, H W; Lever, J R; Ravert, H T; Dannals, R F; Guilarte, T R; Wagner, H N

    1993-12-01

    This study describes assessment of brain muscarinic acetylcholinergic receptors in living mice using a single-crystal radiation detection system, the high-affinity antagonist [125I]-4-iododexetimide, and the inactive enantiomer [125I]-4-iodolevetimide. Kinetics of radioligand binding, as well as perturbation by atropine displacement, can be determined using this simple probe technique. PMID:8152535

  19. Retrospective Analysis of Local Control and Cosmetic Outcome of 147 Periorificial Carcinomas of the Face Treated With Low-Dose Rate Interstitial Brachytherapy

    SciTech Connect

    Ducassou, Anne; David, Isabelle; Filleron, Thomas; Rives, Michel; Bonnet, Jacques; Delannes, Martine

    2011-11-01

    Purpose: Skin cancer is the most common malignancy in white populations. We evaluated the local cure rate and cosmetic outcome of patients with basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) of the face treated with low-dose rate brachytherapy. Methods and Materials: Between February 1990 and May 2000, 147 facial carcinomas in 132 patients were treated by {sup 192}Ir wire implantation. Side effects of brachytherapy were noted. Follow-up was 2 years or more. Locoregional recurrence-free survival (LRFS) and overall survival were recorded. Group A included patients treated by primary brachytherapy, and Group B included those treated after recurrence. Results: A total of 121 carcinomas were BCCs (82.3%) and 26 were SCCs (17.7%); the median tumor size was 10 mm. Of the tumors, 86 (58.5%) were in men and 61 (41.5%) were in women; the median age was 71 years. Group A comprised 116 lesions (78.9%), and Group B, 31 (21.1%). There were 17 relapses (11.6%) after a median follow-up of 72 months: 12 local, 4 nodal, and 1 local and nodal. Locoregional-free survival was 96.6% at 2 years and 87.3% at 5 years. Five-year LRFS was 82.6% in men and 93.3% in women (p = 0.027). After adjustment for gender, LRFS was better after primary treatment than after recurrence (hasard ratio HR, 2.91; 95% confidence interval, 1.06-8.03; p = 0.039). Five-year LRFS was 90.4% for BCC and 70.8% for SCC (p = 0.03). There were no Grade 3 complications. Conclusions: Low-dose rate brachytherapy offers good local control and cosmetic outcome in patients with periorificial skin carcinomas, with no Grade 3 complications. Brchytherapy is more efficient when used as primary treatment.

  20. SU-E-T-55: Biological Equivalent Dose (BED) Comparison Between Permanent Interstitial Brachytherapy and Conventional External Beam Radiotherapy for Prostate Cancer

    SciTech Connect

    Liu, X; Rahimian, J; Cosmatos, H; Goy, B; Heywood, C; Qian, Y

    2014-06-01

    Purpose: The goal of this research is to calculate and compare the Biological Equivalent Dose (BED) between permanent prostate Iodine-125 implant brachytherapy as monotherapy with the BED of conventional external beam radiation therapy (EBRT). Methods: A retrospective study of 605 patients treated with Iodine-125 seed implant was performed in which physician A treated 274 patients and physician B treated 331 patients. All the Brachytherapy treatment plans were created using VariSeed 8 planning system. The Iodine-125 seed source activities and loading patterns varied slightly between the two physicians. The prescription dose is 145 Gy to PTV for each patient. The BED and Tumor Control Probability (TCP) were calculated based on the TG 137 formulas. The BED for conventional EBRT of the prostate given in our institution in 2Gy per fraction for 38 fractions was calculated and compared. Results: Physician A treated 274 patients with an average BED of 123.92±0.87 Gy and an average TCP of 99.20%; Physician B treated 331 patients with an average BED of 124.87±1.12 Gy and an average TCP of 99.30%. There are no statistically significant differences (T-Test) between the BED and TCP values calculated for these two group patients.The BED of the patients undergoing conventional EBRT is calculated to be 126.92Gy. The BED of the patients treated with permanent implant brachytherapy and EBRT are comparable. Our BED and TCP values are higher than the reported values by TG 137 due to higher Iodine-125 seed activity used in our institution. Conclusion: We calculated the BED,a surrogate of the biological response to a permanent prostate brachytherapy using TG 137 formulas and recommendation. The TCP of better than 99% is calculated for these patients. A clinical outcome study of these patients correlating the BED and TCP values with PSA and Gleason Levels as well as patient survival is warranted.

  1. Efficacy and safety of image-guided interstitial single fraction high-dose-rate brachytherapy in the management of metastatic malignant melanoma

    PubMed Central

    Bretschneider, Tina; Mohnike, Konrad; Hass, Peter; Seidensticker, Ricarda; Göppner, Daniela; Dudeck, Oliver; Streitparth, Florian

    2015-01-01

    Purpose Computed tomography (CT) or magnetic resonance imaging (MRI) guided brachytherapy provides high tumor control rates in hepatocellular carcinoma (HCC) and colorectal liver metastases. In contrast to thermal ablation methods such as radiofrequency ablation (RFA), much less restrictions apply with respect to tumor location or size. In this study, we determined the efficacy and safety of CT- or MRI-guided brachytherapy in metastatic melanoma. Material and methods Fifty-two metastases of malignant melanoma in 14 patients were included in this retrospective study. Local tumor control and safety were evaluated as primary and secondary endpoints. Furthermore, we evaluated overall survival and progression free survival. Tumor locations were liver (n = 31), lung (n = 15), adrenal (n = 3), lymph nodes (n = 2), and kidney (n = 1). Treatment planning was performed using three-dimensional CT or MRI data acquired after percutaneous applicator positioning under CT or open MRI guidance. Subsequently, single fraction high-dose-rate (HDR) brachytherapy was applied using a 192Iridium source. Clinical and cross-sectional follow-up were performed every 3 months post intervention. Results The median diameter of treated lesions was 1.5 cm (range: 0.7-10 cm). Doses between 15 and 20 Gy were applied (median dose: 19.9 Gy). The mean irradiation time ranged between 7-45 minutes. After treatment, there was one patient with a cholangitis. After a median follow up of five months, the median local tumor control was 90%. The median overall survival of the patients was 8 months. The median progression free survival of the patients was 6 months. Conclusions Image-guided HDR brachytherapy is a safe and effective treatment procedure in metastatic malignant melanoma. PMID:26034497

  2. Metabolism and placental transfer of /sup 125/I-proinsulin and /sup 125/I-tyrosylated C-peptide in the pregnant rhesus monkey

    SciTech Connect

    Gruppuso, P.A.; Susa, J.B.; Sehgal, P.; Frank, B.; Schwartz, R.

    1987-10-01

    /sup 125/I-Proinsulin or /sup 125/I-tyrosylated-C-peptide (/sup 125/I-tyr-CP) was administered to pregnant Rhesus monkeys by bolus followed by constant infusion to examine placental transfer of these peptides. At the end of each infusion, fetuses were exsanguinated in situ via the umbilical vein. The bolus-constant infusion technique produced a steady state in maternal plasma of immunoprecipitable label, measured using excess insulin or C-peptide antiserum. In animals infused with /sup 125/I-proinsulin, analysis of umbilical venous plasma revealed no apparent transfer to the fetus of immunoprecipitable label. In animals infused with /sup 125/I-tyr-CP, 3-13% of the umbilical venous plasma radioactivity was immunoprecipitable, representing 1.4-5.8% of the immunoprecipitable radioactivity in maternal plasma at delivery. Gel filtration chromatography of umbilical venous plasma revealed that the immunoprecipitated moiety was a fragment of /sup 125/I-tyr-CP. Analysis of maternal plasma showed that the predominant peak of radioactivity represented intact C-peptide. A peak corresponding to the fetal immunoprecipitable peak was also present. Analysis of simultaneous maternal arterial and uterine vein plasma samples showed that degradation of /sup 125/I-tyr-CP occurred across the uterus. Studies in one nonpregnant and three postpartum animals indicated that pregnancy increased the rate of metabolism of /sup 125/I-tyr-CP. When /sup 125/I-tyr-CP was incubated with trophoblastic cells in culture, degradation to a species corresponding on gel filtration to the immunoprecipitable fetal metabolite was found. We conclude that proinsulin, like insulin, does not traverse the placenta. Immunoreactive fragments of C-peptide do cross, however, and pregnancy alters the metabolism of /sup 125/I-tyr-CP, probably owing to placental degradation.

  3. Autoradiographic comparison of [125I]epidepride and [125I]NCQ 298 binding to human brain extrastriated dopamine receptors.

    PubMed

    Hall, H; Halldin, C; Jerning, E; Osterlund, M; Farde, L; Sedvall, G

    1997-07-01

    Extrastriatal D2-dopamine receptors can be visualised in the monkey and human brain using the benzamides [11C]- and [76Br]FLB 457 in PET and [123I]epidepride in SPECT but not with the salicylamide analogues [76Br]FLB 463 and [123I]NCQ 298. To clarify the background for the differences in binding seen in vivo, we have compared the in vitro binding of [125I]epidepride and [123I]NCQ 298, using human whole hemisphere autoradiography. The images obtained with any radioligand showed detailed distribution with very dense binding in the putamen and the caudate nucleus and with the same detailed extrastriatal distribution. Thus, the divergent results obtained in vivo cannot be explained by different binding properties of the extrastriatal receptors. PMID:9290072

  4. Ruthenium-106 brachytherapy.

    PubMed

    Pe'er, Jacob

    2012-01-01

    Brachytherapy is the most common method for treating uveal melanoma, and currently the ruthenium-106 (Ru-106) and iodine-125 (I-125) applicators are the most frequently used. Ru-106 applicators were introduced by Prof. Peter Lommatzsch in the 1960s, and since then have been used widely by many ocular oncologists, mainly in Europe. The Ru-106 isotope is a beta ray (electron) emitter, and as such it has a limited depth of penetration. This is the reason why many experts use Ru-106 applicators for tumors with a maximal thickness of up to 7.0 mm, although others use it successfully for thicker tumors. The Ru-106 applicators are manufactured commercially and have a half-life of about 1 year. Ru-106 brachytherapy for uveal melanoma provides excellent local control rates and eye preservation with a relatively low recurrence rate. The main advantage of Ru-106 over other isotopes is the better preservation of vision in the treated eye, and less damage to the healthy parts of the eye due to its limited range of radiation. This can also be achieved by positioning the Ru-106 plaque eccentrically, away from the macula and optic nerve head. Ru-106 brachytherapy can be used in combination with other methods of treatment of uveal melanoma, such as local resection or transpupillary thermotherapy, and is sporadically combined with other isotopes, such as gamma-emitting cobalt-60 and I-125. PMID:22042011

  5. The use of new GAFCHROMIC EBT film for {sup 125}I seed dosimetry in Solid Water phantom

    SciTech Connect

    Chiu-Tsao, Sou-Tung; Medich, David; Munro, John III

    2008-08-15

    Radiochromic film dosimetry has been extensively used for intravascular brachytherapy applications for near field within 1 cm from the sources. With the recent introduction of new model of radiochromic films, GAFCHROMIC EBT, with higher sensitivity than earlier models, it is promising to extend the distances out to 5 cm for low dose rate (LDR) source dosimetry. In this study, the use of new model GAFCHROMIC EBT film for {sup 125}I seed dosimetry in Solid Water was evaluated for radial distances from 0.06 cm out to 5 cm. A multiple film technique was employed for four {sup 125}I seeds (Implant Sciences model 3500) with NIST traceable air kerma strengths. Each experimental film was positioned in contact with a {sup 125}I seed in a Solid Water phantom. The products of the air kerma strength and exposure time ranged from 8 to 3158 U-h, with the initial air kerma strength of 6 U in a series of 25 experiments. A set of 25 calibration films each was sequentially exposed to one {sup 125}I seed at about 0.58 cm distance for doses from 0.1 to 33 Gy. A CCD camera based microdensitometer, with interchangeable green (520 nm) and red (665 nm) light boxes, was used to scan all the films with 0.2 mm pixel resolution. The dose to each {sup 125}I calibration film center was calculated using the air kerma strength of the seed (incorporating decay), exposure time, distance from seed center to film center, and TG43U1S1 recommended dosimetric parameters. Based on the established calibration curve, dose conversion from net optical density was achieved for each light source. The dose rate constant was determined as 0.991 cGy U{sup -1} h{sup -1} ({+-}6.9%) and 1.014 cGy U{sup -1} h{sup -1} ({+-}6.8%) from films scanned using green and red light sources, respectively. The difference between these two values was within the uncertainty of the measurement. Radial dose function and 2D anisotropy function were also determined. The results obtained using the two light sources corroborated each

  6. Microbial contamination detection at low levels by [125]I radiolabeling

    NASA Astrophysics Data System (ADS)

    Summers, David; Karouia, Fathi

    Contamination of mission spacecraft is an ongoing issue. A broad diversity of microorganisms have been detected in clean rooms where spacecraft are assembled. Some of which, depicted as oligotroph, are of special regard, as they are capable of colonizing inorganic surfaces like metal, and have been shown to be a concern for forward contamination of pristine celestial bodies. Currently, the NASA standard assay is the only approved assay intended for the enumeration of spores and heterotrophic microbial populations. However, culture-based microbial detection methods underestimate the viable microbial population. More recently, adenosine triphosphate (ATP) bioluminescence and limulus amebocyte lysate (LAL) assays, which employ measure-ments of selected metabolic products as a proxy of biomass, have been used successfully to circumvent the necessity of the growth of microorganisms in order to estimate the biodurdens associated with spacecraft assembly facility. However, these methods have limitation in the amount of cells that can be detected, i.e., 103 cells, and the type of microorganisms respec-tively. This work seeks to develop a new highly sensitive method for the determination of bioburdens (and the detection of microorganisms and life) that is independant of the type of organism while preserving a good turn-around time for analysis for planetary protection purposes. The assay is based on the detection of the organism's protein by labeling them by radioiodination, 125 I, of aromatic rings on tyrosine amino acids residues. Radiolabeling techniques are inherently sensitive and 125 I, in particular, benefits from a 60 day half-life, providing greater activity and signal per unit number of labels. Furthermore, microorganisms can contain over 50% of protein by dry weight. Thus, just one label per protein increases the sensitivity, compared to the ATP and LAL assays, by one and three orders of magnitude by using standard detection methods and the use of multiphoton

  7. AB012. Brachytherapy for localized prostate cancer

    PubMed Central

    Xu, Yong; Yang, Yong

    2016-01-01

    Background To evaluate the security and effect of brachytherapy for localized prostate cancer. Methods Forty five patients with Tl–T2 prostate cancer were treated with real-time transperineal ultrasound-guide 125I seeds prostate implantation. Results The median operation time was 90 min, the median number of I seeds used was 56. The follow up time was 12–48 months, the cases of PSA <1 µg/L were 29, PSA 1–2 µg/L were 11 and PSA ≥2 µg/L were 5. Conclusions Brachytherapy for localized prostate cancer is safe and effective.

  8. Whole-Pelvis Radiotherapy in Combination With Interstitial Brachytherapy: Does Coverage of the Pelvic Lymph Nodes Improve Treatment Outcome in High-Risk Prostate Cancer?

    SciTech Connect

    Bittner, Nathan; Wallner, Kent E.; Butler, Wayne M.; Galbreath, Robert; Adamovich, Edward

    2010-03-15

    Purpose: To compare biochemical progression-free survival (bPFS), cause-specific survival (CSS), and overall survival (OS) rates among high-risk prostate cancer patients treated with brachytherapy and supplemental external beam radiation (EBRT) using either a mini-pelvis (MP) or a whole-pelvis (WP) field. Methods and Materials: From May 1995 to October 2005, 186 high-risk prostate cancer patients were treated with brachytherapy and EBRT with or without androgen-deprivation therapy (ADT). High-risk prostate cancer was defined as a Gleason score of >=8 and/or a prostate-specific antigen (PSA) concentration of >=20 ng/ml. Results: With a median follow-up of 6.7 years, the 10-year bPFS, CSS, and OS rates for the WP vs. the MP arms were 91.7% vs. 84.4% (p = 0.126), 95.5% vs. 92.6% (p = 0.515), and 79.5% vs. 67.1% (p = 0.721), respectively. Among those patients who received ADT, the 10-year bPFS, CSS, and OS rates for the WP vs. the MP arms were 93.6% vs. 90.1% (p = 0.413), 94.2% vs. 96.0% (p = 0.927), and 73.7% vs. 70.2% (p = 0.030), respectively. Among those patients who did not receive ADT, the 10-year bPFS, CSS, and OS rates for the WP vs. the MP arms were 82.4% vs. 75.0% (p = 0.639), 100% vs. 88% (p = 0.198), and 87.5% vs. 58.8% (p = 0.030), respectively. Based on multivariate analysis, none of the evaluated parameters predicted for CSS, while bPFS was best predicted by ADT and percent positive biopsy results. OS was best predicted by age and percent positive biopsy results. Conclusions: For high-risk prostate cancer patients receiving brachytherapy, there is a nonsignificant trend toward improved bPFS, CSS, and OS rates when brachytherapy is given with WPRT. This trend is most apparent among ADT-naive patients, for whom a significant improvement in OS was observed.

  9. Synthesis of [{sup 125}I]iodoDPA-713: A new probe for imaging inflammation

    SciTech Connect

    Wang, Haofan; Pullambhatla, Mrudula; Guilarte, Tomas R.; Mease, Ronnie C.; Pomper, Martin G.

    2009-11-06

    [{sup 125}I]IodoDPA-713 [{sup 125}I]1, which targets the translocator protein (TSPO, 18 kDa), was synthesized in seven steps from methyl-4-methoxybenzoate as a tool for quantification of inflammation in preclinical models. Preliminary in vitro autoradiography and in vivo small animal imaging were performed using [{sup 125}I]1 in a neurotoxicant-treated rat and in a murine model of lung inflammation, respectively. The radiochemical yield of [{sup 125}I]1 was 44 {+-} 6% with a specific radioactivity of 51.8 GBq/{mu}mol (1400 mCi/{mu}mol) and >99% radiochemical purity. Preliminary studies showed that [{sup 125}I]1 demonstrated increased specific binding to TSPO in a neurotoxicant-treated rat and increased radiopharmaceutical uptake in the lungs of an experimental inflammation model of lung inflammation. Compound [{sup 125}I]1 is a new, convenient probe for preclinical studies of TSPO activity.

  10. Binding and degradation of (/sup 125/I)human growth hormone in rat adipocytes

    SciTech Connect

    Gorin, E.; Grichting, G.; Goodman, H.M.

    1984-08-01

    Iodinated human growth hormone (( /sup 125/I)hGH) binds to both specific and nonspecific sites on the surface of adipocytes isolated from the epididymal fat of normal rats. When adipocytes were incubated at 37 C with 1 nM (/sup 125/I)hGH, specific binding increased for 30-60 min and thereafter remained approximately constant as long as the hormone was present in the medium. About 90% of the /sup 125/I released was soluble in 5% trichloroacetic acid and was in the form of iodotyrosine. The rate of /sup 125/I release from specific binding sites decreased by a factor of 4 when the temperature was lowered from 37 to 17 C. Replacement of some of the sodium chloride in the buffer with 25 mM ammonium chloride had little or no effect on the amount on /sup 125/I that bound to cells when (/sup 125/I)hGH was present in the medium, but completely blocked the release of /sup 125/I from cells transferred to hormone-free medium. Ammonium chloride also significantly reduced both the release of /sup 125/I from nonspecific binding sites and the amount of /sup 125/I recovered in trichloroacetic acid-soluble form. Cloroquine, leupeptin, or colchicine nearly doubled the specific binding of (/sup 125/I)hGH after 180 min and markedly slowed the release of /sup 125/I when cells were transferred to hormone-free medium. All of these agents also significantly reduced the rate of release of /sup 125/I from nonspecific binding sites. Incubation of adipose tissue from hypophysectomized rats with ammonium chloride, leupeptin, or colchicine failed to alter the ability of GH to increase glucose oxidation, induce refractoriness, or promote lipolysis in the presence of theophylline.

  11. Rectal toxicity profile after transperineal interstitial permanent prostate brachytherapy: Use of a comprehensive toxicity scoring system and identification of rectal dosimetric toxicity predictors

    SciTech Connect

    Shah, Jinesh N.; Ennis, Ronald D. . E-mail: rennis@chpnet.org

    2006-03-01

    Purpose: To better understand rectal toxicity after prostate brachytherapy, we employed the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE version 3.0), a comprehensive system with distinct and separately reported gastrointestinal adverse event items (unlike Radiation Therapy Oncology Group morbidity scoring), to evaluate item-specific postimplant rectal toxicities. Methods and Materials: We analyzed 135 patients treated with brachytherapy {+-} hormonal therapy, using CTCAE v3.0 to score acute/late rectal toxicities (median follow-up, 41 months). Dosimetric parameters were evaluated for ability to predict toxicities. Results: Use of CTCAE yielded a novel rectal toxicity profile consisting of diarrhea, incontinence, urgency, proctitis, pain, spasms, and hemorrhage event rates. No item had a <5% Grade 1-2 acute toxicity rate (except spasms). Rectal dosimetry predicted late toxicities: for diarrhea, 5% Grade 1 toxicity rate for %V{sub 25} (percent of rectal volume receiving 25% of prescribed prostate dose) {<=} 25% vs. 60% for %V{sub 25} > 25% (p < 0.001); for maximum toxicity, 10% Grade 1 toxicity rate for %V{sub 1} {<=} 40% vs. 44% for %V{sub 1} > 40% (p = 0.007). Conclusions: A comprehensive understanding of item-specific postimplant rectal toxicities was obtained using CTCAE. Rectal %V{sub 25} > 25% and %V{sub 1} > 40% predicted worse late diarrhea and maximum toxicity, respectively.

  12. Radiosynthesis and Evaluation of 5-[125I]Iodoindol-3-yl-β-D-galactopyranoside ([125I]IBDG) as a β-Galactosidase Imaging Radioligand

    PubMed Central

    Van Dort, Marcian E.; Lee, Kuei C.; Hamilton, Christin A.; Rehemtulla, Alnawaz; Ross, Brian D.

    2009-01-01

    The synthesis and investigation of 5-[125I]Iodoindol-3-yl-β-D-galactopyranoside ([125I]IBDG) as a radioligand for single photon emission computed tomography (SPECT) imaging of β-galactosidase expression is described. No-carrier-added [125I]IBDG was synthesized by a radioiododestannylation approach in >75% overall radiochemical yield and >99% radiochemical purity. [125I]IBDG was evaluated as a substrate using β-galactosidase-expressing (D54L) and non-expressing (D54) human glioma cell lines. A 24 h incubation of this substrate with cultured cells revealed a 6.5-fold greater intracellular trapping of radioactivity in D54L cells compared to D54 cells. Systemic delivery of [125I]IBDG in nude mice bearing D54L tumors failed to show significant trapping of radioactivity within these tumors by SPECT imaging. In contrast, intratumoral injection of the substrate resulted in efficient trapping of radioactivity in D54L tumors but not D54 tumors resulting in clear SPECT visualization of the former tumor. Based on dynamic SPECT imaging and blood metabolite analysis, we conclude that although [125I]IBDG is an efficient in vivo substrate for β-galactosidase, its rapid renal clearance hampers its intratumoral availability upon systemic administration. PMID:19123989

  13. In Vivo Dosimetry Using a Linear Mosfet-Array Dosimeter to Determine the Urethra Dose In {sup 125}I Permanent Prostate Implants

    SciTech Connect

    Bloemen-van Gurp, Esther J. Murrer, Lars H.P.; Haanstra, Bjoerk K.C.; Gils, Francis C.J.M. van; Dekker, Andre L.A.J.; Mijnheer, Ben J.; Lambin, Philippe

    2009-01-01

    Purpose: In vivo dosimetry during brachytherapy of the prostate with {sup 125}I seeds is challenging because of the high dose gradients and low photon energies involved. We present the results of a study using metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to evaluate the dose in the urethra after a permanent prostate implantation procedure. Methods and Materials: Phantom measurements were made to validate the measurement technique, determine the measurement accuracy, and define action levels for clinical measurements. Patient measurements were performed with a MOSFET array in the urinary catheter immediately after the implantation procedure. A CT scan was performed, and dose values, calculated by the treatment planning system, were compared to in vivo dose values measured with MOSFET dosimeters. Results: Corrections for temperature dependence of the MOSFET array response and photon attenuation in the catheter on the in vivo dose values are necessary. The overall uncertainty in the measurement procedure, determined in a simulation experiment, is 8.0% (1 SD). In vivo dose values were obtained for 17 patients. In the high-dose region (> 100 Gy), calculated and measured dose values agreed within 1.7% {+-} 10.7% (1 SD). In the low-dose region outside the prostate (< 100 Gy), larger deviations occurred. Conclusions: MOSFET detectors are suitable for in vivo dosimetry during {sup 125}I brachytherapy of prostate cancer. An action level of {+-} 16% (2 SD) for detection of errors in the implantation procedure is achievable after validation of the detector system and measurement conditions.

  14. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    SciTech Connect

    Hattangadi, Jona A.; Powell, Simon N.; MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek; Freer, Phoebe; Lawenda, Brian; Alm El-Din, Mohamed A.; Gadd, Michele A.; Smith, Barbara L.; Taghian, Alphonse G.

    2012-07-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall's tau ({tau}{sub {beta}}) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4-14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome ({tau}{sub {beta}} 0.6, p < .0001), lower patient satisfaction ({tau}{sub {beta}} 0.5, p < .001), and worse fibrosis ({tau}{sub {beta}} 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias {>=}1 cm{sup 2}. Grade 3-4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose ({tau}{sub {beta}} 0.3-0.5, p {<=} .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence-free survival

  15. A systematic evaluation of the dose-rate constant determined by photon spectrometry for twenty-one different models of low energy photon-emitting brachytherapy sources

    PubMed Central

    Chen, Zhe (Jay); Nath, Ravinder

    2012-01-01

    Purpose To perform a systematic comparison of the dose-rate constant (Λ) determined by the photon spectrometry technique (PST) with the consensus value (CONΛ) recommended by the American Association of Physicist in Medicine (AAPM) for twenty-one low energy photon-emitting interstitial brachytherapy sources. Method and Materials A total of 63 interstitial brachytherapy sources (21 different models with 3 sources per model) containing either 125I (14 models), 103Pd (6 models), or 131Cs (one model) were included in this study. A photon spectrometry technique (Med. Phys. 34, 1412-1430, 2007) was used to determine the dose-rate constant (PSTΛ) for each source model. Source-dependent variations in PSTΛ were analyzed systematically against the spectral characteristics of the emitted photons and the consensus values recommended by the AAPM brachytherapy subcommittee. Results The values of PSTΛ for the encapsulated sources of 103Pd, 125I, and 131Cs varied from 0.661 cGyh-1U-1 to 0.678 cGyh-1U-1, 0.959 cGyh-1U-1 to 1.024 cGyh-1U-1, and 1.066 cGyh-1U-1 to 1.073 cGyh-1U-1, respectively. The relative variation in PSTΛ among the six 103Pd source models, caused by variations in photon attenuation and in spatial distributions of radioactivity among the source models, was less than 3%. Greater variations in PSTΛ were observed among the fourteen 125I source models; the maximum relative difference was over 6%. These variations were caused primarily by the presence of silver in some 125I source models and, to a lesser degree, by the variations in photon attenuation and in spatial distribution of radioactivity among the source models. The presence of silver generates additional fluorescent x-rays with lower photon energies which caused the PSTΛ value to vary from 0.959 cGyh-1U-1 to 1.019 cGyh-1U-1 depending on the amount of silver used by a given source model. For those 125I sources that contain no silver, their PSTΛ was less variable and had values within 1% of 1.024 cGyh-1U

  16. Isolation of /sup 125/I-concanavalin A-labeled plasma membrane from unfertilized mouse eggs

    SciTech Connect

    Boldt, J.; Wolf, D.P.

    1987-04-01

    A procedure was developed for isolation of plasma membrane (PM) preparations from unfertilized mouse eggs. Zona-free mouse eggs prepared by the method of Boldt and Wolf (Gamete Res 13:213-222, 1986) were labeled with 125I-concanavalin A (ConA) prior to sonication and fractionation on iso-osmotic self-generated Percoll density gradients. Experiments using the ConA-specific sugar alpha-methylmannoside (alpha MM) indicated that 125I-ConA bound specifically to the egg PM. Greater than 95% of 125I-ConA binding to zona-free eggs was blocked in the presence of 0.1 M alpha MM, and incubation of eggs in alpha MM after 125I-ConA labeling caused release of 85-90% of bound label. Fractionation of 125I-ConA-labeled eggs by Percoll density gradient centrifugation yielded a single radioactive peak at density = 1.025, corresponding to egg PM material. Prolonged incubation of 125I-ConA-labeled eggs or egg sonicates prior to fractionation did not alter the location of the radioactive peak, indicating that 125I-ConA did not label other organelles. As a control, human erythrocytes were labeled with 125I-ConA and fractionated under identical experimental conditions and yielded a single radioactive peak at density (1.020) comparable to that observed for 125I-ConA-labeled eggs. These results indicate that 125I-ConA can be used as a specific marker to support PM isolation from small numbers of zona-free mouse eggs.

  17. 125I-labeled anti-bFGF monoclonal antibody inhibits growth of hepatocellular carcinoma

    PubMed Central

    Hu, Peng-Hui; Pan, Lan-Hong; Wong, Patrick Ting-Yat; Chen, Wen-Hui; Yang, Yan-Qing; Wang, Hong; Xiang, Jun-Jian; Xu, Meng

    2016-01-01

    AIM: To investigate the inhibitory efficacy of 125I-labeled anti-basic fibroblast growth factor (bFGF) monoclonal antibody (mAb) in hepatocellular carcinoma (HCC). METHODS: bFGF mAb was prepared by using the 1G9B9 hybridoma cell line with hybridization technology and extracted from ascites fluid through a Protein G Sepharose affinity column. After labeling with 125I through the chloramine-T method, bFGF mAb was further purified by a Sephadex G-25 column. Gamma radiation counter GC-1200 detected radioactivity of 125I-bFGF mAb. The murine H22 HCC xenograft model was established and randomized to interventions with control (phosphate-buffered saline), 125I-bFGF mAb, 125I plus bFGF mAb, bFGF mAb, or 125I. The ratios of tumor inhibition were then calculated. Expression of bFGF, fibroblast growth factor receptor (FGFR), platelet-derived growth factor, and vascular endothelial growth factor (VEGF) mRNA was determined by quantitative reverse transcriptase real-time polymerase chain reaction. RESULTS: The purified bFGF mAb solution was 8.145 mg/mL with a titer of 1:2560000 and was stored at -20 °C. After coupling, 125I-bFGF mAb was used at a 1: 1280000 dilution, stored at 4 °C, and its specific radioactivity was 37 MBq/mg. The corresponding tumor weight in the control, 125I, bFGF mAb, 125I plus bFGF mAb, and 125I-bFGF mAb groups was 1.88 ± 0.25, 1.625 ± 0.21, 1.5 ± 0.18, 1.41 ± 0.16, and 0.98 ± 0.11 g, respectively. The tumor inhibition ratio in the 125I, bFGF mAb, 125I plus bFGF mAb, and 125I-bFGF mAb groups was 13.6%, 20.2%, 25.1%, and 47.9%, respectively. Growth of HCC xenografts was inhibited significantly more in the 125I-bFGF mAb group than in the other groups (P < 0.05). Expression of bFGF and FGFR mRNA in the 125I-bFGF mAb group was significantly decreased in comparison with other groups (P < 0.05). Groups under interventions revealed increased expression of VEGF mRNA (except for 125I group) compared with the control group. CONCLUSION: 125I-bFGF m

  18. ( sup 125 I)Iodoazidococaine, a photoaffinity label for the haloperidol-sensitive sigma receptor

    SciTech Connect

    Kahoun, J.R.; Ruoho, A.E. )

    1992-02-15

    A carrier-free radioiodinated cocaine photoaffinity label, (-)-3-({sup 125}I)iodo-4-azidococaine (({sup 125}I)IACoc), has been synthesized and used as a probe for cocaine-binding proteins. Photoaffinity labeling with 0.5 nM ({sup 125}I)IACoc resulted in selective derivatization of a 26-kDa polypeptide with the pharmacology of a sigma receptor in membranes derived from whole rat brain, rat liver, and human placenta. ({sup 125}I)IACoc labeling of the 26-kDa polypeptide was also inhibited by 10 {mu}M imipramine, amitriptyline, fluoxetine, benztropine, and tetrabenazine. The size of the ({sup 125}I)I-ACoc-labeled proteins is consistent with the size of proteins photolabeled in guinea pig brain and liver membranes by using the sigma photolabel azido-({sup 3}H)DTG. Kinetic analysis of ({sup 125}I)IACoc binding to rat liver microsomes revealed two sites with K{sub d} values of 19 and 126 pM, respectively. The presence or absence of proteolytic inhibitors during membrane preparation did not alter the size of the photolabeled sigma receptor, indicating that the 26-kDa polypeptide was not derived from a larger protein. In summary, ({sup 125}I)IACoc is a potent and highly specific photoaffinity label for the haloperidol-sensitive sigma receptor and will be useful for its biochemical and molecular characterization.

  19. Primary Gleason Grade 4 Impact on Biochemical Recurrence After Permanent Interstitial Brachytherapy in Japanese Patients With Low- or Intermediate-Risk Prostate Cancer

    SciTech Connect

    Uesugi, Tatsuya; Saika, Takashi; Edamura, Kohei; Nose, Hiroyuki; Kobuke, Makoto; Ebara, Shin; Abarzua, Fernand; Katayama, Norihisa; Yanai, Hiroyuki; Nasu, Yasutomo; Kumon, Hiromi

    2012-02-01

    Purpose: To reveal a predictive factor for biochemical recurrence (BCR) after permanent prostate brachytherapy (PPB) using iodine-125 seed implantation in patients with localized prostate cancer classified as low or intermediate risk based on National Comprehensive Cancer Network (NCCN) guidelines. Methods and Materials: From January 2004 to December 2009, 414 consecutive Japanese patients with clinically localized prostate cancer classified as low or intermediate risk based on the NCCN guidelines were treated with PPB. The clinical factors including pathological data reviewed by a central pathologist and follow-up data were prospectively collected. Kaplan-Meier and Cox regression analyses were used to assess the factors associated with BCR. Results: Median follow-up was 36.5 months. The 2-, 3-, 4-, and 5-year BCR-free rates using the Phoenix definition were 98.3%, 96.0%, 91.6%, and 87.0%, respectively. On univariate analysis, the Gleason score, especially primary Gleason grade 4 in biopsy specimens, was a strong predicting factor (p < 0.0001), while age, initial prostate-specific antigen (PSA) level, T stage, and minimal dose delivered to 90% of the prostate volume (D90) were insignificant. Multivariate analysis indicated that a primary Gleason grade 4 was the most powerful prognostic factor associated with BCR (hazard ratio = 6.576, 95% confidence interval, 2.597-16.468, p < 0.0001). Conclusions: A primary Gleason grade 4 carried a worse BCR prognosis than the primary grade 3 in patients treated with PPB. Therefore, the indication for PPB in patients with a Gleason sum of 4 + 3 deserves careful and thoughtful consideration.

  20. Distribution of peripherally injected peptide YY ([125I] PYY (3-36)) and pancreatic polypeptide ([125I] hPP) in the CNS: enrichment in the area postrema.

    PubMed

    Dumont, Yvan; Moyse, Emmanuel; Fournier, Alain; Quirion, Rémi

    2007-01-01

    The mechanism by which blood-borne peptide YY (3-36) (PYY(3-36)) and pancreatic polypeptide (PP) inhibit food intake is not clear and could implicate peripheral (vagal afferent pathways) and/or central (direct action on specific brain nuclei) mechanisms. To identify the primary brain structure(s) that could be activated after a peripheral injection of neuropeptide Y-related peptides, we investigated the distribution of radioactive materials using whole body autoradiography and coronal brain sections. Rats were injected with [125I] porcine (p) PYY(3-36) (i.p., 10 microCi) and killed after 30 min, 1, 2, or 4 h. After i.p. administration, significant amounts of radioactive materials were rapidly (<30 min) detected in the blood circulation and various tissues including the kidneys, liver, lung, heart, bone marrow, gastrointestinal tract, and thyroid gland, whereas in the brain, low but significant amounts of radioactive materials were detected at the level of the area postrema. Next, we investigated the distribution of radioactive labeling in the brain after i.v. injections of [125I]pPYY(3-36) (Y2 and Y5 subtypes), [125I] human (h) PP (Y4 and Y5 receptors), and [125I][Leu(31), Pro(34)] pPYY (Y1, Y4 and Y5 classes) in the rat brain. Fifteen minutes post injection, autoradiograms revealed positive signals only in the area postrema after the injection of [125I]-hPP and [125I][Leu(31), Pro(34)]pPYY. Whereas the presence of [125I]pPYY(3-36)-related labeling was detected in the area postrema, subfornical organ, and median eminence. In all other brain structures, including all hypothalamic nuclei and other circumventricular organs, near background level signals were detected. These data suggest that the inhibition of food intake observed after peripheral injections of pPYY(3-36) and hPP could involve receptor activation preferentially located at the level of the area postrema, a structure well-known to be involved in the modulation of food intake. PMID:17952639

  1. Microchemical synthesis of the serotonin receptor ligand, /sup 125/I-LSD

    SciTech Connect

    Hartig, P.R.; Krohn, A.M.; Hirschman, S.A.

    1985-02-01

    The synthesis and properties of 2-(/sup 125/I)-lysergic acid diethylamide, the first /sup 125/I-labeled serotonin receptor ligand, are described. A novel microsynthesis apparatus was developed for this synthesis. The apparatus employs a micromanipulator and glass micro tools to handle microliter to nanoliter volumes on a microscope stage. This apparatus should be generally useful for the synthesis of radioligands and other compounds when limited amounts of material must be handled in small volumes.

  2. Intracellular modification of /sup 125/I-labeled epidermal growth factor by normal human foreskin fibroblasts

    SciTech Connect

    Schaudies, R.P.; Savage, C.R. Jr.

    1986-02-01

    Intracellular processing of /sup 125/I-labeled epidermal growth factor (EGF) in normal human foreskin fibroblasts was examined after incubation with saturating concentrations of (/sup 125/I)EGF. This report describes the column chromatographic separation of multiple processed forms of EGF generated by human foreskin fibroblasts and their structural characterization. More than 95% of the cell-bound (/sup 125/I)EGF was converted into multiple forms, which were separated into four distinct peaks of radioactivity using columns of Bio-Gel P-150 equilibrated with 0.2% sodium dodecyl sulfate. These were designated peaks 1-4. Cellular generation of these four peaks was dependent on culture conditions. Differences in absolute and relative amounts of peaks 1-4 were observed as a function of time of incubation at 37 C. In addition, chromatographic profiles of cell-associated /sup 125/I varied in relation to cell density. The radioactivity in peak 1 comigrated with /sup 125/I-labeled native EGF on nondenaturing polyacrylamide gels (pH 9.5), whereas peaks 2 and 3 exhibited more rapid electrophoretic mobilities. Electrophoretic mobilities of the radioactivity in peaks 2 and 3 were indistinguishable from those of chemically prepared derivatives of (/sup 125/I)EGF which were lacking either one or six amino acid residues from the carboxyterminus, respectively. The EGF receptor bound the radioactive material in peak 2 with an affinity equal to or greater than that of EGF; however, the radioactivity in peak 3 was bound to a much lesser extent. The radiolabel in both peaks 2 and 3 was greater than 95% precipitable by antiserum to native EGF. The labeled material in peak 4 was composed of (/sup 125/I)monoiodotyrosine, /sup 125/I-, and an unidentified peptide. None of the radiolabeled compounds in peak 4 interacted with the EGF receptor or with antiserum to native EGF.

  3. Evidence for multiple pathways of sup 125 I-insulin internalization in isolated rat hepatocytes

    SciTech Connect

    Moss, A.L.

    1988-01-01

    Insulin internalization has been characterized frequently as occurring by the coated pit pathway of receptor-mediated endocytosis. The present study in rat hepatocytes demonstrates that insulin internalization is, in part, receptor-mediated, but also occurs by nonreceptor-mediated or fluid-phase endocytosis. Endocytosis was probed with four perturbations: depletion of metabolic energy with anoxia, inhibition of endocytosis with phenylarsine oxide, disruption of coated pits with hyperosmolar sucrose, and inhibition of receptor recycling or ligand-receptor dissociation with monensin. Internalization of {sup 125}I-epidermal growth factor and {sup 125}I-asialofetuin was compared to {sup 125}I-insulin internalization. Pretreatment of cells with anoxia or hyperosmolarity inhibited {sup 125}I-insulin internalization by 40%; pretreatment with phenylarsine oxide resulted in inhibition by 54%. Monensin has no effect on uptake or degradation of a high insulin concentration, but inhibited degradation of a low insulin concentration resulting in intracellular accumulation of insulin. In contract, all four perturbations inhibited {sup 125}I-asialofetuin internalization by greater than 90%. Phenylarsine oxide almost completely abolished {sup 125}I-epidermal growth factor uptake; the other perturbations caused partial inhibition. Competition studies demonstrated that insulin internalization was receptor-mediated over a wide concentration range.

  4. Heparin blocks /sup 125/I-calmodulin internalization by isolated rat renal brush border membrane vesicles

    SciTech Connect

    Meezan, E.; Elgavish, A.; Roden, L.; Wallace, R.W.

    1986-03-05

    /sup 125/I-Calmodulin is internalized by isolated rat renal brush border membrane vesicles (BBV) in a time, temperature and calcium dependent manner. Internalization of /sup 125/I-calmodulin into the osmotically sensitive space of BBV was distinguished from binding of the ligand to the outer BBV surface by examining the interaction of ligand and BBV at different medium osmolarities (300-1100 mosm), uptake was inversely proportional to medium osmolarity. Internalized /sup 125/I-calmodulin was intact and Western blots of solubilized BBV with /sup 125/I-calmodulin demonstrated the presence of several calmodulin-binding proteins of 143, 118, 50, 47.5, 46.5 and 35 kilodaltons which could represent potential intravesicular binding sites for the ligand. Heparin and the related glycosaminoglycan heparin sulfate both showed a dose-dependent inhibition (0.5-50 ..mu..g/ml) of /sup 125/I-calmodulin uptake by BBV, but other sulfated and nonsulfated glycosaminoglycans including chondroitin sulfates, keratan sulfate and hyaluronic acid showed little or no inhibitory effect. Desulfation of heparin virtually abolished the inhibition of uptake while depolymerization reduced it. Heparin did not block the binding of /sup 125/I-calmodulin to BBV proteins as assessed by Western blotting technique suggesting its effect was on internalization of the ligand rather than on its association with internal membrane proteins.

  5. Brachytherapy of recurrent malignant brain tumors with removable high-activity iodine-125 sources

    SciTech Connect

    Gutin, P.H.; Phillips, T.L.; Wara, W.M.; Leibel, S.A.; Hosobuchi, Y.; Levin, V.A.; Weaver, K.A.; Lamb, S.

    1984-01-01

    Thirty-seven patients harboring recurrent malignant primary or metastatic brain tumors were treated by 40 implantations of high-activity iodine-125 (/sup 125/I) sources. All patients had been treated with irradiation and most had been treated with chemotherapeutic agents, primarily nitrosoureas. Implantations were performed using computerized tomography (CT)-directed stereotaxy; /sup 125/I sources were held in one or more afterloaded catheters that were removed after the desired dose (minimum tumor dose of 3000 to 12,000 rads) had been delivered. Patients were followed with sequential neurological examinations and CT scans. Results of 34 implantation procedures were evaluable: 18 produced documented tumor regression (response) for 4 to 13+ months; five, performed in deteriorating patients, resulted in disease stability for 4 to 12 months. The overall response rate was 68%. In 11 patients, implantation did not halt clinical deterioration. At exploratory craniotomy 5 to 12 months after implantation, focal radiation necrosis was documented in two patients whose tumor had responded initially and then progressed, and in three patients whose disease had progressed initially (four glioblastomas, one anaplastic astrocytoma); histologically identifiable tumor was documented in two of these patients. All improved after resection of the focal necrotic mass and are still alive 10, 15, 19, 24, and 25 months after the initial implantation procedure; only one patient has evidence of tumor regrowth. The median follow-up period after implantation for the malignant glioma (anaplastic astrocytoma and glioblastoma multiforme) group is 9 months, with 48% of patients still surviving. While direct comparison with the results of chemotherapy is difficult, results obtained in this patient group with interstitial brachytherapy are probably superior to results obtained with chemotherapy.

  6. Influence of acetylcholine on binding of 4-[125I]iododexetimide to muscarinic brain receptors.

    PubMed

    Weckesser, M; Fixmann, A; Holschbach, M; Müller-Gärtner, H W

    1998-11-01

    The distribution of nicotinic and muscarinic cholinergic receptors in the human brain in vivo has been successfully characterized using radiolabeled tracers and emission tomography. The effect of acetylcholine release into the synaptic cleft on receptor binding of these tracers has not yet been investigated. The present study examined the influence of acetylcholine on binding of 4-[125I]iododexetimide to muscarinic cholinergic receptors of porcine brain synaptosomes in vitro. 4-Iododexetimide is a subtype-unspecific muscarinic receptor antagonist with high affinity. Acetylcholine competed with 4-[125I]iododexetimide in a dose-dependent manner. A concentration of 500 microM acetylcholine inhibited 50% of total specific 4-[125I]iododexetimide binding to synaptosomes when both substances were given simultaneously. An 800 microM acetylcholine solution reduced total specific 4-[125I]iododexetimide binding by about 35%, when acetylcholine was given 60 min after incubation of synaptosomes with 4-[125I]iododexetimide. Variations in the synaptic acetylcholine concentration might influence muscarinic cholinergic receptor imaging in vivo using 4-[123I]iododexetimide. Conversely, 4-[123I]iododexetimide might be an appropriate molecule to investigate alterations of acetylcholine release into the synaptic cleft in vivo using single photon emission computed tomography. PMID:9863566

  7. Radioimmunoassay of salivary cyclosporine with use of /sup 125/I-labeled cyclosporine

    SciTech Connect

    Coates, J.E.; Lam, S.F.; McGaw, W.T.

    1988-08-01

    We prepared /sup 125/I-labeled cyclosporine (/sup 125/I-CS) by modifying the procedure of Mahoney and Orf and characterized it with regards to maximal immunoreactivity (greater than 90%), trichloroacetic acid precipitability (greater than 90%), and stability (90% immunoreactive after five half-lives of /sup 125/I). For a particular preparation of /sup 125/I-CS, we estimated its immunoreaction concentration (50 pmol/L) and the equilibrium constant for its reaction with Sandoz polyclonal antiserum (K = 3.9 X 10(9) L/mol). By substituting /sup 125/I-CS as tracer in the Sandoz radioimmunoassay and by modifying other aspects of the assay, we developed a procedure that is sufficiently sensitive (0.34 micrograms/L) to allow measurement of trough (lowest inter-dose) cyclosporine concentrations in parotid saliva. Of 38 kidney-transplant patients, 35 had measurable concentrations in saliva (mean 8.3, SD 5.2 micrograms/L), and these correlated moderately with paired serum concentrations (r = 0.68, P less than 0.001). We believe that measurement of salivary cyclosporine may offer a simple way of estimating the free fraction of the drug in serum or plasma.

  8. E-17 alpha(/sup 125/I)iodovinylestradiol: an estrogen-receptor-seeking radiopharmaceutical

    SciTech Connect

    Hanson, R.N.; Seitz, D.E.; Botarro, J.C.

    1982-05-01

    Through the use of radioiododestannylation, the specifically labeled E-17 alpha-(/sup 125/I)iodovinylestradiol ((/sup 125/I)VE2) was synthesized rapidly and in high yield from the stable precursor E-17 alpha-tributylstannylvinylestradiol (SnVE2), and its biodistribution was determined in immature female rats. The agent accumulated in the uterus, achieving a peak uptake of 0.465% ID-kg/g at 2 hr. Uterus-to-blood ratios of 19 and 16 occurred at 1 and 2 hr, respectively, declining to 7 by 4 hr after injection. The uptake of (/sup 125/I)VE2 by the uterus at 2 hr was reduced 58--65% by pretreatment of the immature rats with estradiol (5 micrograms) or tamoxifen (100 micrograms), and compared with 16 alpha-(/sup 125/I)iodoestradiol, (/sup 125/I)VE2 showed greater uterine uptake and similar uterus-to-blood ratios. The ease of preparation of the radioligand represents an advantage over the synthetic procedures for other estrogen-receptor-seeking agents.

  9. Biodistribution and dosimetry of free 211At, 125I- and 131I- in rats.

    PubMed

    Spetz, Johan; Rudqvist, Nils; Forssell-Aronsson, Eva

    2013-11-01

    131I is widely used for therapy in the clinic and 125I and 131I, and increasingly 211At, are often used in experimental studies. It is important to know the biodistribution and dosimetry for these radionuclides to determine potential risk organs when using radiopharmaceuticals containing these radionuclides. The purpose of this study was to investigate the biodistribution of 125I-, 131I-, and free 211At in rats and to determine absorbed doses to various organs and tissues. Male Sprague Dawley rats were injected simultaneously with 0.1-0.3 MBq 125I- and 0.1-0.3 MBq 131I-, or 0.05-0.2 MBq 211At and sacrificed 1 hour to 7 days after injection. The activities and activity concentrations in organs and tissues were determined and mean absorbed doses were calculated. The biodistribution of 125I- was similar to that of 131I- but the biodistribution of free 211At was different compared to 125I- and 131I-. The activity concentration of radioiodine was higher compared with 211At in the thyroid and lower in all extrathyroidal tissues. The mean absorbed dose per unit injected activity was highest to the thyroid. 131I gave the highest absorbed dose to the thyroid, and 211At gave the highest absorbed dose to all other tissues studied. PMID:23789969

  10. Radioimmunoassay for etorphine in horses with a /sup 125/I analog of etorphine

    SciTech Connect

    Tai, C.L.; Wang, C.; Weckman, T.J.; Popot, M.A.; Woods, W.E.; Yang, J.M.; Blake, J.; Tai, H.H.; Tobin, T.

    1988-05-01

    To improve the sensitivity and specificity of screening for etorphine in horses, an /sup 125/I-labeled etorphine analog was synthesized and an antibody to etorphine was raised in rabbits. A radioimmunoassay (RIA) for etorphine was developed, using these reagents. Bound and free /sup 125/I-labeled etorphine was separated by a double-antibody method that reduced interference from materials associated with equine urine. The /sup 125/I-labeled etorphine binding was rarely greater than 250 pg of background etorphine equivalents/ml in raw urine and was 100 pg/ml in hydrolyzed urine. The /sup 125/I-RIA was capable of detecting etorphine equivalents in urine above these background values. Etorphine equivalents were detected in equine urine samples for about 7 days after 4 mares were dosed with 0.22 microgram of etorphine/kg of body weight, IV. The stability of etorphine in urine from these mares was evaluated. Urine from these dosed mares was held in constant -20 C storage, and aliquots were repeatedly frozen and thawed. When analyzed for etorphine equivalents using an /sup 125/I-RIA, etorphine and its metabolites in urine samples were stable for less than or equal to 38 days if continuously frozen and also were resistant to repeated freezing and thawing.

  11. Optimized method for measuring cyclosporin A with /sup 125/I-labeled cyclosporin

    SciTech Connect

    Felder, R.A.; Mifflin, T.E.; Bastani, B.

    1986-07-01

    We evaluated the use of the new iodinated ligand for the in vitro measurement of cyclosporin A by radioimmunoassay (RIA). Substitution of the iodinated cyclosporin (/sup 125/I-CyA) for the corresponding tritium-labeled analog (/sup 3/H-CyA) considerably simplifies and accelerates the currently available RIA, and improves its precision. Analysis of the respective dose-response curves showed that the 50% B0 value was lower for the /sup 125/I-CyA assay than for the /sup 3/H-CyA assay (37 vs 77 micrograms/L). Use of whole-blood specimens minimized interferences from temperature and hematocrit. We conclude that the use of /sup 125/I-CyA in a commercially available RIA for whole-blood specimens is accessible to most laboratories and provides rapid, reproducible data for management of transplant patients.

  12. PSA Kinetics and PSA Bounce Following Permanent Seed Prostate Brachytherapy

    SciTech Connect

    Crook, Juanita Gillan, Caitlin B.Sc.; Yeung, Ivan Ph.D.; Austen, Lynette; McLean, Michael; Lockwood, Gina M.Math.

    2007-10-01

    Purpose: To report the incidence, timing, and magnitude of the benign prostate-specific antigen (PSA) bounce after {sup 125}I prostate brachytherapy and correlate the bounce with clinical and/or dosimetric factors. Methods and Materials: From March 1999 to August 2003, a total of 292 men received {sup 125}I prostate brachytherapy without androgen deprivation or supplemental beam radiotherapy and have PSA follow-up >30 months. Implants were preplanned using transrectal ultrasound (TRUS) and performed under transrectal ultrasound/fluoroscopy guidance using preloaded needles. A PSA bounce is defined as an increase {>=}0.2 ng/ml with spontaneous return to prebounce level or lower. Results: Resolved PSA bounces were seen in 40% of men with follow-up >30 months. Median onset was 15 months, and median magnitude was 0.76 ng/ml. Magnitude >2 ng/ml was seen in 15%. The only clinical or dosimetric factor predictive of bounce in multivariate analysis was younger age. Median time to increasing PSA level indicative of failure was 30 months. Conclusions: Benign PSA bounces are common after {sup 125}I prostate brachytherapy, especially in younger men. An increase >2 ng/ml above the nadir was seen in 15%. Magnitude of increase does not distinguish bounce from failure. Time to the start of the PSA increase can be helpful, but is not absolute. The PSA bounce does not predict subsequent failure. Caution is advised in interpreting an early increasing PSA level in the first 30 months after {sup 125}I brachytherapy in favorable-risk patients.

  13. 2-([sup 125]I) iodomelatonin binding sites in rat adrenals: Pharmacological characteristics and subcellular distribution

    SciTech Connect

    Persengiev, S.P. )

    1992-01-01

    Specific binding sites for 2-[[sup 125]I] iodomelatonin, a selective radiolabeled melatonin receptor ligand, were detected and characterized in rat adrenal membranes. Saturation studies demonstrated that 2-[[sup 125]I]iodomelatonin binds to a single class of sites with an affinity constant (Kd) of 541 pM and a total binding capacity (Bmax) of 3.23 fmol/mg protein. Competition experiments revealed that the relative order of potency of compounds tested was as follows: 6-chloromelatonin > 2-iodomelatonin > melatonin > 5-methoxytryptamine > 5-methoxytryptophol. The highest density of binding sites was found in membranes from nuclear and mitochondrial subcellular fractions.

  14. Increased /sup 125/I-labelled concanavalin A binding to erythrocytes in diabetes mellitus

    SciTech Connect

    Okada, Y.; Arima, T.; Okazaki, S.; Nakata, K.; Nagashima, H.; Yamabuki, T.

    1982-03-01

    Percentage binding of /sup 125/I-labelled concanavalin A to erythrocytes in diabetic patients was significantly higher than that in normal subjects (12.2 +- 2.8 versus 8.1 +- 1.8%, mean +- SD, p < 0.001). Insulin-dependent diabetic patients showed significantly higher concanavalin A binding than non-insulin-dependent diabetic subjects (15.0 +- 1.4 versus 11.4 +- 2.5%, p < 0.01). There was a highly significant correlation between percentage binding of /sup 125/I-labelled concanavalin A and glycosylated haemoglobin.

  15. Interstitial Nephritis

    MedlinePlus

    ... rye-tus) is a kidney disorder. The kidneys filter waste and extra fluid from the body. Interstitial nephritis reduces the kidneys’ ability to filter properly. Interstitial nephritis is a serious condition, but ...

  16. A modern Monte Carlo investigation of the TG-43 dosimetry parameters for an {sup 125}I seed already having AAPM consensus data

    SciTech Connect

    Aryal, Prakash; Molloy, Janelle A.; Rivard, Mark J.

    2014-02-15

    Purpose: To investigate potential causes for differences in TG-43 brachytherapy dosimetry parameters in the existent literature for the model IAI-125A{sup 125}I seed and to propose new standard dosimetry parameters. Methods: The MCNP5 code was used for Monte Carlo (MC) simulations. Sensitivity of dose distributions, and subsequently TG-43 dosimetry parameters, was explored to reproduce historical methods upon which American Association of Physicists in Medicine (AAPM) consensus data are based. Twelve simulation conditions varying{sup 125}I coating thickness, coating mass density, photon interaction cross-section library, and photon emission spectrum were examined. Results: Varying{sup 125}I coating thickness, coating mass density, photon cross-section library, and photon emission spectrum for the model IAI-125A seed changed the dose-rate constant by up to 0.9%, about 1%, about 3%, and 3%, respectively, in comparison to the proposed standard value of 0.922 cGy h{sup −1} U{sup −1}. The dose-rate constant values by Solberg et al. [“Dosimetric parameters of three new solid core {sup 125}I brachytherapy sources,” J. Appl. Clin. Med. Phys. 3, 119–134 (2002)], Meigooni et al. [“Experimental and theoretical determination of dosimetric characteristics of IsoAid ADVANTAGE™ {sup 125}I brachytherapy source,” Med. Phys. 29, 2152–2158 (2002)], and Taylor and Rogers [“An EGSnrc Monte Carlo-calculated database of TG-43 parameters,” Med. Phys. 35, 4228–4241 (2008)] for the model IAI-125A seed and Kennedy et al. [“Experimental and Monte Carlo determination of the TG-43 dosimetric parameters for the model 9011 THINSeed™ brachytherapy source,” Med. Phys. 37, 1681–1688 (2010)] for the model 6711 seed were +4.3% (0.962 cGy h{sup −1} U{sup −1}), +6.2% (0.98 cGy h{sup −1} U{sup −1}), +0.3% (0.925 cGy h{sup −1} U{sup −1}), and −0.2% (0.921 cGy h{sup −1} U{sup −1}), respectively, in comparison to the proposed standard

  17. Dopamine transport sites selectively labeled by a novel photoaffinity probe: 125I-DEEP

    SciTech Connect

    Grigoriadis, D.E.; Wilson, A.A.; Lew, R.; Sharkey, J.S.; Kuhar, M.J. )

    1989-08-01

    The dopamine transporter was labeled using a photosensitive compound related to GBR-12909, {sup 125}I-1-(2-(diphenylmethoxy)ethyl)-4-(2- (4-azido-3-iodophenyl)ethyl)piperazine ({sup 125}I-DEEP). {sup 125}I-DEEP bound reversibly and with high affinity to the dopamine transport protein in the absence of light and could be covalently attached to the protein following exposure to UV light. In rat striatal homogenates, {sup 125}I-DEEP was found to incorporate covalently into a protein with apparent molecular weight of 58,000 Da. The properties of this binding protein were characteristic of the dopamine transporter since covalent attachment could be inhibited by dopamine-uptake blockers with the proper pharmacological rank order of potencies. Covalent binding was also inhibited in a stereospecific manner by (+) and (-) cocaine, as well as other cocaine analogs. The protein was not found in the cerebellum. The dopamine transporter appears to exist in a glycosylated form since photoaffinity-labeled transport sites could adsorb to wheat germ-agglutinin and could be specifically eluted from the column by beta-N-acetylglucosamine.

  18. Absolute quantitative autoradiography of low concentrations of (/sup 125/I)-labeled proteins in arterial tissue

    SciTech Connect

    Schnitzer, J.J.; Morrel, E.M.; Colton, C.K.; Smith, K.A.; Stemerman, M.B.

    1987-12-01

    We developed a method for absolute quantitative autoradiographic measurement of very low concentrations of (/sup 125/I)-labeled proteins in arterial tissue using Kodak NTB-2 nuclear emulsion. A precise linear relationship between measured silver grain density and isotope concentration was obtained with uniformly labeled standard sources composed of epoxy-embedded gelatin containing glutaraldehyde-fixed (/sup 125/I)-albumin. For up to 308-day exposures of 1 micron-thick tissue sections, background grain densities ranged from about two to eight grains/1000 micron 2, and the technique was sensitive to as little as about one grain/1000 micron 2 above background, which correspond to a radioactivity concentration of about 2 x 10(4) cpm/ml. A detailed statistical analysis of variability was performed and the sum of all sources of variation quantified. The half distance for spatial resolution was 1.7 micron. Both visual and automated techniques were employed for quantitative grain density analysis. The method was illustrated by measurement of in vivo transmural (/sup 125/I)-low-density lipoprotein (( /sup 125/I)-LDL) concentration profiles in de-endothelialized rabbit thoracic aortic wall.

  19. Solid-phase receptor binding assay for /sup 125/I-hCG

    SciTech Connect

    Bortolussi, M.; Selmin, O.; Colombatti, A.

    1987-01-01

    A solid-phase radioligand-receptor assay (RRA) to measure the binding of /sup 125/I-labelled human chorionic gonadotropin (/sup 125/I-hCG) to target cell membranes has been developed. The binding of /sup 125/I-hCG to membranes immobilized on the wells of microtitration plates reached a maximum at about 3 hours at 37 degrees C, was saturable, displayed a high affinity (Ka = 2.4 X 10(9) M-1) and was specifically inhibited by unlabelled hCG. In comparison with RRAs carried out with membranes in suspension, the solid-phase RRA is significantly simpler and much faster to perform as it avoids centrifugation or filtration procedures. The solid-phase RRA was adapted profitably to process large numbers of samples at the same time. It proved particularly useful as a screening assay to detect anti-hCG monoclonal antibodies with high inhibitory activity for binding of /sup 125/I-hCG to its receptors.

  20. Retention and degradation of 125I-insulin by perfused livers from diabetic rats.

    PubMed

    Terris, S; Steiner, D F

    1976-04-01

    The retention of degradation of insulin by isolated perfused liver have been examined. Noncyclically perfused livers from streptozotocin-diabetic rats retained 25% and degraded 10% of 125I-insulin administered as a 1-min pulse. On gel filtration (Sephadex G50F), the degradation products released into the vascular effluent eluted in the salt peak. During the 45-min interval after the end of the 125I-insulin infusion, 0.19% of the total dose was excreted in the bile. 60-90% of this material consisted of iodinated, low-molecular-weight degradation products. Inclusion of native insulin with the 125I-insulin in the pulse depressed both the retention and degradation of iodinated material; however, this reflected increased retention and degradation of the total insulin dose (125I-insulin plus native hormone). The log of the total amounts of insulin retained and degraded were linearly related to the log of the total amount of insulin infused at concentrations between 12.7 nM and 2.84 muM. Increasing the amount of native insulin in the infused pulse also depressed the total amount of iodinated material found in the bile and led to the appearance in the bile of intermediate-sized degradation products that did not simultaneously appear in the vascular effluent. Addition of high concentrations of glucagon to the infused 125I-insulin had no effect on the retention or degradation of the labeled hormone, or on the apparent size and amount of iodinated degradation products found in the vascular effluent or in the bile. Preinfusion of concanavalin A inhibited both 125I-insulin retention and degradation. A greater depression by concanavalin A of degradation than binding was also observed with isolated hepatocytes. In contrast to 125I-insulin, the retention and degradation of two iodinated insulin analogues of relative low biological potency, proinsulin and desalanyl-desasparaginyl insulin, were small. The amount of radioactivity appearing in the bile after infusion of these

  1. Retention and degradation of 125I-insulin by perfused livers from diabetic rats.

    PubMed Central

    Terris, S; Steiner, D F

    1976-01-01

    The retention of degradation of insulin by isolated perfused liver have been examined. Noncyclically perfused livers from streptozotocin-diabetic rats retained 25% and degraded 10% of 125I-insulin administered as a 1-min pulse. On gel filtration (Sephadex G50F), the degradation products released into the vascular effluent eluted in the salt peak. During the 45-min interval after the end of the 125I-insulin infusion, 0.19% of the total dose was excreted in the bile. 60-90% of this material consisted of iodinated, low-molecular-weight degradation products. Inclusion of native insulin with the 125I-insulin in the pulse depressed both the retention and degradation of iodinated material; however, this reflected increased retention and degradation of the total insulin dose (125I-insulin plus native hormone). The log of the total amounts of insulin retained and degraded were linearly related to the log of the total amount of insulin infused at concentrations between 12.7 nM and 2.84 muM. Increasing the amount of native insulin in the infused pulse also depressed the total amount of iodinated material found in the bile and led to the appearance in the bile of intermediate-sized degradation products that did not simultaneously appear in the vascular effluent. Addition of high concentrations of glucagon to the infused 125I-insulin had no effect on the retention or degradation of the labeled hormone, or on the apparent size and amount of iodinated degradation products found in the vascular effluent or in the bile. Preinfusion of concanavalin A inhibited both 125I-insulin retention and degradation. A greater depression by concanavalin A of degradation than binding was also observed with isolated hepatocytes. In contrast to 125I-insulin, the retention and degradation of two iodinated insulin analogues of relative low biological potency, proinsulin and desalanyl-desasparaginyl insulin, were small. The amount of radioactivity appearing in the bile after infusion of these

  2. Methodology for characterizing seeds under development for brachytherapy by means of radiochromic and photographic films.

    PubMed

    Meira-Belo, L C; Rodrigues, E J T; Grynberg, S E

    2013-04-01

    The development of new medical devices possess a number of challenges, including designing, constructing, and assaying prototypes. In the case of new brachytherapy seeds, this is also true. In this paper, a methodology for rapid dosimetric characterization of (125)I brachytherapy seeds during the early stages of their development is introduced. The characterization methodology is based on the joint use of radiochromic and personal monitoring photographic films in order to determine the planar anisotropy due to the radiation field produced by the seed under development, by means of isodose curves. To evaluate and validate the process, isodose curves were obtained with both types of films after irradiation with a commercial (125)I brachytherapy seed. PMID:23353089

  3. Binding and internalization of /sup 125/I-CCK8 in fundic gastric glands

    SciTech Connect

    Praissman, M.; Walden, M.

    1987-05-01

    The authors have characterized the binding and internalization of cholecystokinin (CCK8), a peptide hormone involved in the regulation of gastric secretory processes, in isolated fundic gastric glands (GG) from guinea pig. Surface bound and internalized /sup 125/I-CCK8 radioligand (RL) were differentiated by glycine-HCl treatment. At 24/sup 0/C, steady state binding (2.9%) of RL to surface sites was found at 5 min and remained constant for 2 h; internalized /sup 125/I-CCK8 increased steadily and was 4- and 6-fold greater at 30 and 120 min, respectively, than surface bound RL. At 4/sup 0/C, surface binding reached 2.7% at 30 min and continued to increase to 4.5% at 180 min; internalized RL levels reached only 1.4% at 180 min. The metabolic inhibitor, carbonyl cyanide m-chlorophenyl-hydrazone, reduced the amount of RL internalized by 80% in 30 min at 24/sup 0/C while reducing surface binding by only 20%. The lysosomal inhibitor, chloroquine reduced the amounts of /sup 125/I-CCK8 internalized by 21 and 34% at 100 and 500 uM, respectively, without affecting surface binding. Dansylcadaverine at 250uM had no effect on the binding or internalization of RL. At 24/sup 0/C, approx. 55% of surface bound /sup 125/I-CCK8 dissociated in 1 h and 67% in 2 h; less than 15% of internalized RL dissociated in the same time period. These data indicate that the internalization of /sup 125/I-CCK-8 is a rapid and energy dependent process, and that internalized RL may undergo lysosomal action.

  4. Permanent iodine 125 brachytherapy in patients with progressive or recurrent glioblastoma multiforme

    PubMed Central

    Larson, David A.; Suplica, Jeffrey M.; Chang, Susan M.; Lamborn, Kathleen R.; McDermott, Michael W.; Sneed, Penny K.; Prados, Michael D.; Wara, William M.; Nicholas, M. Kelly; Berger, Mitchel S.

    2004-01-01

    This study reports the initial experience at the University of California San Francisco (UCSF) with tumor resection and permanent, low-activity iodine 125 (125I) brachytherapy in patients with progressive or recurrent glioblastoma multiforme (GM) and compares these results to those of similar patients treated previously at UCSF with temporary brachytherapy without tumor resection. Thirty-eight patients with progressive or recurrent GM were treated at UCSF with repeat craniotomy, tumor resection, and permanent, low-activity 125I brachytherapy between June 1997 and May 1998. Selection criteria were Karnofsky performance score ⩾60, unifocal, contrast-enhancing, well-circumscribed progressive or recurrent GM that was judged to be completely resectable, and no evidence of leptomeningeal or subependymal spread. The median brachytherapy dose 5 mm exterior to the resection cavity was 300 Gy (range, 150–500 Gy). One patient was excluded from analysis. Median survival was 52 weeks from the date of brachytherapy. Age, Karnofsky performance score, and preimplant tumor volume were all statistically significant on univariate analyses. Multivariate analysis for survival showed only age to be significant. Median time to progression was 16 weeks. Both univariate and multivariate analysis of freedom from progression showed only preoperative tumor volume to be significant. Comparison to temporary brachytherapy patients showed no apparent difference in survival time. Chronic steroid requirements were low in patients with minimal postoperative residual tumor. We conclude that permanent 125I brachytherapy for recurrent or progressive GM is well tolerated. Survival time was comparable to that of a similar group of patients treated with temporary brachytherapy. PMID:15134626

  5. Identification of beta 2-adrenoceptors on guinea pig alveolar macrophages using (-)-3-( sup 125 I)iodocyanopindolol

    SciTech Connect

    Leurs, R.; Beusenberg, F.D.; Bast, A.; Van Amsterdam, J.G.; Timmerman, H. )

    1990-08-01

    The beta-adrenoceptor antagonist (-)-3-({sup 125}I)iodocyanopindolol (({sup 125}I)ICYP) binds with high affinity and in saturable way to membranes of guinea pig alveolar macrophages. The equilibrium dissociation constant for ({sup 125}I)ICYP is 24.3 +/- 1.2 pM, and the number of binding sites is 166.3 +/- 13.7 fmol/mg protein (N = 4, +/- SEM). Displacement studies with selective antagonists showed that ({sup 125}I)ICYP labels beta 2-adrenoceptors on guinea pig alveolar macrophages.

  6. (R)-N-Methyl-3-(3-125I-pyridin-2-yloxy)-3-phenylpropan-1-amine ([125I]PYINXT) : a novel probe for norepinephrine transporters (NET)

    PubMed Central

    Lakshmi, B.; Kung, M-P.; Lieberman, B.; Zhao, J.; Waterhouse, R.; H.F.Kung

    2008-01-01

    Alterations in the serotonin and norepinephrine neuronal functions have been observed in patients with major depression. Several antidepressants bind to both serotonin transporters (SERT) and norepinephrine transporters (NET). The ability to image NET in the human brain would be a useful step toward understanding how alterations in NET relate to disease. In this study, we report the synthesis and characterization of a new series of derivatives of iodo-nisoxetine (INXT), a known radioiodinated probe. The most promising, (R)-N-methyl-3-(3-iodopyridin-2-yloxy)-3-phenylpropylamine (PYINXT) 9, displayed a high and saturable binding to NET with a Kd value of 0.53 ± 0.03 nM. Biodistribution studies of [125I]PYINXT in rats showed moderate initial brain uptake (0.54 %dose/organ at 2 min) with a relatively fast washout from the brain (0.16 %dose/organ at 2 hr) as compared to [125I]INXT, 7. The hypothalamus (a NET rich region) to striatum (a region devoid of NET) ratio was found to be 2.14 at 4 hr post i.v. injection. The preliminary results suggest that this improved iodinated ligand, when labeled with 123I, may be useful for mapping NET binding sites with SPECT in the living human brain. PMID:18158942

  7. Mouse model of brachytherapy in consort with enucleation for treatment of malignant intraocular melanoma

    SciTech Connect

    Niederkorn, J.; Sanborn, G.E.; Scarbrough, E.E. )

    1990-06-01

    The efficacy of brachytherapy in the treatment and prevention of metastasis of intraocular melanoma was investigated in a mouse model. A highly metastatic subline of B16 melanoma was transplanted into the anterior segment of C57BL/6 mice and allowed to grow. Brachytherapy was delivered by means of miniature iodine 125 seeds implanted in shallow subcutaneous pockets of the upper eyelid margin of these mice, and 25 Gy of radiation was delivered between days 12 and 14. This brachytherapy reduced both the tumor volume and the number of mitotic figures per high-power field compared with irradiated controls. In a second experiment, 25 Gy of brachytherapy was delivered before enucleation, straddling enucleation, and after enucleation; there was a significant reduction in metastasis when radiation was delivered prior to enucleation. This model may be useful in conducting further studies involving brachytherapy with 125I plaque implants.

  8. Ocular Response of Choroidal Melanoma With Monosomy 3 Versus Disomy 3 After Iodine-125 Brachytherapy

    SciTech Connect

    Marathe, Omkar S.; Wu, Jeffrey; Lee, Steve P.; Yu Fei; Burgess, Barry L.; Leu Min; Straatsma, Bradley R.; McCannel, Tara A.

    2011-11-15

    Purpose: To report the ocular response of choroidal melanoma with monosomy 3 vs. disomy 3 after {sup 125}I brachytherapy. Methods and Materials: We evaluated patients with ciliochoroidal melanoma managed with fine needle aspiration biopsy immediately before plaque application for {sup 125}I brachytherapy between January 1, 2005 and December 31, 2008. Patients with (1) cytopathologic diagnosis of melanoma, (2) melanoma chromosome 3 status identified by fluorescence in situ hybridization, and (3) 6 or more months of follow-up after brachytherapy were sorted by monosomy 3 vs. disomy 3 and compared by Kruskal-Wallis test. Results: Among 40 ciliochoroidal melanomas (40 patients), 15 had monosomy 3 and 25 had disomy 3. Monosomy 3 melanomas had a median greatest basal diameter of 12.00 mm and a median tumor thickness of 6.69 mm before brachytherapy; at a median of 1.75 years after brachytherapy, median thickness was 3.10 mm. Median percentage decrease in tumor thickness was 48.3%. Disomy 3 melanomas had a median greatest basal diameter of 10.00 mm and median tumor thickness of 3.19 mm before brachytherapy; at a median of 2.00 years after brachytherapy, median tumor thickness was 2.37 mm. The median percentage decrease in tumor thickness was 22.7%. Monosomy 3 melanomas were statistically greater in size than disomy 3 melanomas (p < 0.001) and showed a greater decrease in tumor thickness after brachytherapy (p = 0.006). Conclusion: In this study, ciliochoroidal melanomas with monosomy 3 were significantly greater in size than disomy 3 melanoma and showed a significantly greater decrease in thickness at a median of 1.75 years after brachytherapy. The greater decrease in monosomy 3 melanoma thickness after brachytherapy is consistent with other malignancies in which more aggressive pathology has been shown to be associated with a greater initial response to radiotherapy.

  9. Lymphatic flow in humans as indicated by the clearance of /sup 125/I-labeled albumin from the subcutaneous tissue of the leg

    SciTech Connect

    Fernandez, M.J.; Davies, W.T.; Owen, G.M.; Tyler, A.

    1983-08-01

    Since the removal of albumin from the extracellular space and its return to the vascular compartment is the essential function of the lymphatic system, the rate at which it is removed from the interstitial tissue may be regarded as a means of estimating lymphatic efficiency. An objective measure of lymphatic function can be obtained by monitoring the rate of clearance following injection of /sup 125/I-labeled albumin (RIHSA) from the subcutaneous tissue of a limb. The clearance of /sup 125/I-RIHSA from lower limb was monitored in a group of patients with normal limbs, patients with unilateral edema due to deep vein thrombosis, and patients with bilateral edema due to hypoproteinemia. The mean T1/2 in normal legs was 32.7 hr, compared to 23.7 hr in edematous limbs due to deep vein thrombosis and 19.4 in edematous limbs due to hypoproteinemia. There is a clear-cut difference in clearance rate between edematous and nonedematous limbs. This suggests that lymphatic flow is increased in edema due to venous obstruction and hypoproteinemia.

  10. Image guided Brachytherapy: The paradigm of Gynecologic and Partial Breast HDR Brachytherapy

    NASA Astrophysics Data System (ADS)

    Diamantopoulos, S.; Kantemiris, I.; Konidari, A.; Zaverdinos, P.

    2015-09-01

    High dose rate (HDR) brachytherapy uses high strength radioactive sources and temporary interstitial implants to conform the dose to target and minimize the treatment time. The advances of imaging technology enable accurate reconstruction of the implant and exact delineation of high-risk CTV and the surrounding critical structures. Furthermore, with sophisticated treatment planning systems, applicator devices and stepping source afterloaders, brachytherapy evolved to a more precise, safe and individualized treatment. At the Radiation Oncology Department of Metropolitan Hospital Athens, MRI guided HDR gynecologic (GYN) brachytherapy and accelerated partial breast irradiation (APBI) with brachytherapy are performed routinely. Contouring and treatment planning are based on the recommendations of the GEC - ESTRO Working group. The task of this presentation is to reveal the advantages of 3D image guided brachytherapy over 2D brachytherapy. Thus, two patients treated at our department (one GYN and one APBI) will be presented. The advantage of having adequate dose coverage of the high risk CTV and simultaneous low doses to the OARs when using 3D image- based brachytherapy will be presented. The treatment techniques, equipment issues, as well as implantation, imaging and treatment planning procedures will be described. Quality assurance checks will be treated separately.

  11. Visualization of dopamine D3-like receptors in human brain with [125I]epidepride.

    PubMed

    Murray, A M; Ryoo, H; Joyce, J N

    1992-12-01

    In sections of human brain containing the striatum (caudate, nucleus, putamen, nucleus accumbens) the competition for binding of [125I]epidepride by compounds with differing selectivity for dopamine D2 and D3 receptors was examined. Domperidone showed higher affinity for D2-like than D3-like sites whereas 7-OH-DPAT (7-hydroxy-2-(N,N-di-n-propylamino)tetralin) and quinpirole demonstrated the reverse selectivity. The pattern of [125I]epidepride binding in the presence of a high concentration of domperidone was negligible in the dorsal striatum but indicated islands of dense binding to D3-like receptors in the nucleus accumbens and ventral putamen. PMID:1359976

  12. Increased (/sup 125/I)trypsin-binding in serum from cystic fibrosis patients

    SciTech Connect

    Cox, K.L.; Frates, R.C. Jr.; Sheikholislam, B.M.; Iwahashi-Hosoda, C.K.

    1982-01-01

    The capacities of normal and cystic fibrosis (CF) sera to bind to exogenous human (/sup 125/I)trypsin were compared. Sera from eight older CF patients bound significantly more exogenous human (/sup 125/I)trypsin than did sera from eight normal subjects (p less than 0.001). Disregarding the increased trypsin-binding (TB) of CF sera, serum immunoreactive trypsinogen (SIRT) levels were not detectable in these eight older CF patients. However, when SIRT levels were corrected for TB, four CF patients had normal SIRT concentrations and four had low but detectable SIRT levels. As compared to five normal newborns' sera, serum from a newborn with CF had normal TB and the SIRT levels were very high. In conclusion, increased TB in CF serum lowers results of SIRT assays. Therefore, unless SIRT levels are corrected for TB, results obtained from currently available SIRT kits may be invalid.

  13. CT-Guided Radioactive {sup 125}I Seed Implantation Therapy of Symptomatic Retroperitoneal Lymph Node Metastases

    SciTech Connect

    Wang, Zhongmin; Lu, Jian; Gong, Ju; Zhang, Liyun; Xu, Yingjia; Song, Shaoli; Chen, Kemin; Liu, Fenju; Gang, Huang

    2013-04-12

    PurposeThis study explored the clinical efficacy of CT-guided radioactive {sup 125}I seed implantation in treating patients with symptomatic retroperitoneal lymph node metastases.MethodsTwenty-five patients with pathologically confirmed malignant tumors received CT-guided radioactive {sup 125}I seed implantation to treat metastatic lymph nodes. The diameter of the metastatic lymph nodes ranged from 1.5 to 4.5 cm. Treatment planning system (TPS) was used to reconstruct the three-dimensional image of the tumor and then calculate the corresponding quantity and distribution of {sup 125}I seeds.ResultsFollow-up period for this group of patients was 2–30 months, and median time was 16 months. Symptoms of refractory pain were significantly resolved postimplantation (P < 0.05), and Karnofsky score rose dramatically (P < 0.05). Most patients reported pain relief 2–5 days after treatment. Follow-up imaging studies were performed 2 months later, which revealed CR in 7 patients, PR in 13 patients, SD in 3 patients, and PD in 2 patients. The overall effective rate (CR + PR) was 80 %. Median survival time was 25.5 months. Seven patients died of recurrent tumor; 16 patients died of multiorgan failure or other metastases. Two patients survived after 30 months follow-up. Two patients reported localized skin erythema 1 week postimplantation, which disappeared after topical treatment.ConclusionsCT-guided radioactive {sup 125}I seed implantation, which showed good palliative pain relief with acceptable short-term effects, has proved in our study to be a new, safe, effective, and relatively uncomplicated treatment option for symptomatic retroperitoneal metastatic lymph nodes.

  14. Effects of hypothyroidism on vascular /sup 125/I-albumin permeation and blood flow in rats

    SciTech Connect

    Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

    1989-05-01

    Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease.

  15. A Dose–Response Analysis of Biochemical Control Outcomes After {sup 125}I Monotherapy for Patients With Favorable-Risk Prostate Cancer

    SciTech Connect

    Shiraishi, Yutaka; Yorozu, Atsunori; Ohashi, Toshio; Toya, Kazuhito; Saito, Shiro; Nishiyama, Toru; Yagi, Yasuto; Shigematsu, Naoyuki

    2014-12-01

    Purpose: To define the optimal dose for {sup 125}I prostate implants by correlating postimplantation dosimetry findings with biochemical failure and toxicity. Methods and Materials: Between 2003 and 2009, 683 patients with prostate cancer were treated with {sup 125}I prostate brachytherapy without supplemental external beam radiation therapy and were followed up for a median time of 80 months. Implant dose was defined as the D90 (the minimal dose received by 90% of the prostate) on postoperative day 1 and 1 month after implantation. Therefore, 2 dosimetric variables (day 1 D90 and day 30 D90) were analyzed for each patient. We investigated the dose effects on biochemical control and toxicity. Results: The 7-year biochemical failure-free survival (BFFS) rate for the group overall was 96.4% according to the Phoenix definition. A multivariate analysis found day 1 D90 and day 30 D90 to be the most significant factors affecting BFFS. The cutoff points for day 1 D90 and day 30 D90, calculated from ROC curves, were 163 Gy and 175 Gy, respectively. By use of univariate analysis, various dosimetric cutoff points for day 30 D90 were tested. We found that day 30 D90 cutoff points from 130 to 180 Gy appeared to be good for the entire cohort. Greater D90s were associated with an increase in late genitourinary or gastrointestinal toxicity ≥ grade 2, but the increase was not statistically significant. Conclusions: Improvements in BFFS rates were seen with increasing D90 levels. Day 30 D90 doses of 130 to 180 Gy were found to serve as cutoff levels. For low-risk and low-tier intermediate-risk prostate cancer patients, high prostate D90s, even with doses exceeding 180 Gy, achieve better treatment results and are feasible.

  16. Correlation of 125I-LSD autoradiographic labeling with serotonin voltage clamp responses in Aplysia neurons

    SciTech Connect

    Evans, M.L.; Kadan, M.J.; Hartig, P.R.; Carpenter, D.O. )

    1991-05-01

    Autoradiographic receptor binding studies using 125I-LSD (2-(125I)lysergic acid diethyamide) revealed intense labelling on the soma of a symmetrically located pair of cells in the abdominal ganglion of Aplysia californica. This binding was blocked by micromolar concentrations of serotonin and lower concentrations of the serotonergic antagonists, cyproheptadine and mianserin. Electrophysiological investigation of responses to serotonin of neurons in the left upper quadrant, where one of the labeled neurons is located, revealed a range of serotonin responses. Cells L3 and L6 have a K+ conductance increase in response to serotonin that is not blocked by cyproheptadine or mianserin. Cells L2 and L4 have a biphasic response to serotonin: a Na+ conductance increase, which can be blocked by cyproheptadine and mianserin, followed by a voltage dependent Ca2+ conductance which is blocked by Co2+ but not the serotonergic antagonists. Cell L1, and its symmetrical pair, R1, have in addition to the Na+ and Ca2+ responses observed in L2 and L4, a Cl- conductance increase blocked by LSD, cyproheptadine and mianserin. LSD had little effect on the other responses. The authors conclude that the symmetrically located cells L1 and R1 have a Cl- channel linked to a cyproheptadine- and mianserin-sensitive serotonin receptor that is selectively labelled by 125I-LSD. This receptor has many properties in common with the mammalian serotonin 1C receptor.

  17. Visualization of heparin-binding proteins by ligand blotting with /sup 125/I-heparin

    SciTech Connect

    Cardin, A.D.; Witt, K.R.; Jackson, R.L.

    1984-03-01

    A ligand-blotting procedure which allows detection of heparin-binding proteins is described. Crude commercial heparin was fractionated by chromatography on a column of human plasma low-density lipoproteins immobilized to Sepharose CL-4B. Chromatography yielded an unbound and a bound fraction of heparin, designated URH and HRH, respectively. The HRH fraction was reacted with the N-hydroxysuccinimidyl ester of 3-(p-hydroxyphenyl)propionic acid and then labeled with /sup 125/I. Proteins were separated by 3-20% pore-gradient gel electrophoresis, transferred to nitrocellulose, and then assayed for their ability to bind /sup 125/I-labeled HRH. Human plasma apolipoproteins B-100, B-48, and E of chylomicrons, very low-density lipoproteins, and low-density lipoproteins bound the /sup 125/I-labeled HRH; the radiolabeled haparin did not bind to serum albumin, ferritin, catalase, and lactate dehydrogenase. The ligand-blotting procedure should facilitate the purification of heparin-binding domains from these proteins and, moreover may be applicable to the investigation of heparin-protein interactions in general. 15 references.

  18. Characterization of pancreatic somatostatin binding sites with a /sup 125/I-somatostatin 28 analog

    SciTech Connect

    Zeggari, M.; Viguerie, N.; Susini, C.; Esteve, J.P.; Vaysse, N.; Rivier, J.; Wunsch, E.; Ribet, A.

    1986-11-01

    Somatostatin binding to guinea pig pancreatic acinar cell plasma membranes was characterized with an iodinated stable analog of somatostatin 28 (S28): /sup 125/I-(Leu8,DTrp22,Tyr25)S28. The binding was highly dependent on calcium ions. In 0.2 mM free Ca2+ medium, binding at 37 degrees C was saturable, slowly reversible and exhibited a single class of high affinity binding sites (KD = 0.05 +/- 0.01 nM, Bmax = 157 +/- 33 fmol/mg protein). Dissociation of bound radioactivity occurred with biphasic kinetics. Rate of dissociation increased when dissociation was measured at a time before equilibrium binding was reached. In 30 nM free Ca2+ medium, binding affinity and maximal binding capacity were decreased by about 4-fold. Decreasing calcium concentrations increased the amount of rapidly dissociating form of the receptor. Somatostatin 14 antagonist, Des AA1,2(AzaAla4-5,DTrp8, Phe12-13)-somatostatin was active at the membrane level in inhibiting the binding. We conclude that using /sup 125/I-(Leu8,DTrp22,Tyr25)S28 as radioligand allows us to characterize a population of specific somatostatin receptors which are not different from those we previously described with the radioligand /sup 125/I-(Tyr11)-somatostatin. Somatostatin receptors could exist in two interconvertible forms. Calcium ions are an essential component in the regulation of the conformational change of somatostatin receptors.

  19. 2( sup 125 I)Iodomelatonin binding sites in spleens of guinea pigs

    SciTech Connect

    Poon, A.M.S. ); Pang, S.F. )

    1992-01-01

    2-({sup 125}I)Iodomelatonin was found to bind specifically to the membrane preparations of the spleens of guinea pigs with high affinity. The binding was rapid, stable, saturable and reversible. Scatchard analysis of the binding assays revealed an equilibrium dissociation constant (Kd) of 49.8{plus minus}4.12 pmol/l and binding site density (Bmax) of 0.69{plus minus}0.082 fmol/mg protein at mid-light. There was no significant change in the Kd or the Bmax at mid-dark. Kinetic analysis showed a Kd of 23.13{plus minus}4.81 pmol/l, in agreement to that derived from the saturation studies. The 2-({sup 125}I)iodomelatonin binding sites have the following order of potency: 2-iodomelatonin > melatonin > 6-chloromelatonin {much gt} N-acetylserotonin, 6-hydroxymelatonin > 5-methoxytryptamine, 5-methoxytryptophol > serotonin, 5-methoxyindole-3-acetic acid > 5-hydroxytryptophol, 3-acetylindole, 1-acetylindole-3-carboxyaldehyde, L-tryptophan > tryptamine, 5-hydroxyindole-3-acetic acid. Differential centrifugation studies showed that the binding sites are localized mainly in the nuclear fraction, the rest are distributed in the microsomal fraction, mitochondrial fraction and cytosolic fraction. The demonstration of 2-({sup 125}I)iodomelatonin binding sites in the spleen suggests the presence of melatonin receptors and a direct mechanism of action of melatonin on the immune system.

  20. Evaluation of two (125)I-radiolabeled acridine derivatives for Auger-electron radionuclide therapy of melanoma.

    PubMed

    Gardette, Maryline; Viallard, Claire; Paillas, Salomé; Guerquin-Kern, Jean-Luc; Papon, Janine; Moins, Nicole; Labarre, Pierre; Desbois, Nicolas; Wong-Wah-Chung, Pascal; Palle, Sabine; Wu, Ting-Di; Pouget, Jean-Pierre; Miot-Noirault, Elisabeth; Chezal, Jean-Michel; Degoul, Francoise

    2014-08-01

    We previously selected two melanin-targeting radioligands [(125)I]ICF01035 and [(125)I]ICF01040 for melanoma-targeted (125)I radionuclide therapy according to their pharmacological profile in mice bearing B16F0 tumors. Here we demonstrate in vitro that these compounds present different radiotoxicities in relation to melanin and acidic vesicle contents in B16F0, B16F0 PTU and A375 cell lines. ICF01035 is effectively observed in nuclei of achromic (A375) melanoma or in melanosomes of melanized melanoma (B16F0), while ICF01040 stays in cytoplasmic vesicles in both cells. [(125)I]ICF01035 induced a similar survival fraction (A50) in all cell lines and led to a significant decrease in S-phase cells in amelanotic cell lines. [(125)I]ICF01040 induced a higher A50 in B16 cell lines compared to [(125)I]ICF01035 ones. [(125)I]ICF01040 induced a G2/M blockade in both A375 and B16F0 PTU, associated with its presence in cytoplasmic acidic vesicles. These results suggest that the radiotoxicity of [(125)I]ICF01035 and [(125)I]ICF01040 are not exclusively reliant on DNA alterations compatible with γ rays but likely result from local dose deposition (Auger electrons) leading to toxic compound leaks from acidic vesicles. In vivo, [(125)I]ICF01035 significantly reduced the number of B16F0 lung colonies, enabling a significant increase in survival of the treated mice. Targeting melanosomes or acidic vesicles is thus an option for future melanoma therapy. PMID:24691673

  1. In vivo binding of /sup 125/I-LSD to serotonin 5-HT/sub 2/ receptors in mouse brain

    SciTech Connect

    Hartig, P.R.; Scheffel, U., Frost, J.J.; Wagner, H.N. Jr.

    1985-08-19

    The binding of /sup 125/I-LSD (2-(/sup 125/I)-lysergic acid diethylamide) was studied in various mouse brain regions following intravenous injection of the radioligand. The high specific activity of /sup 125/I-LSD enabled the injection of low mass doses (14ng/kg), which are well below the threshold for induction of any known physiological effect of the probe. The highest levels of /sup 125/I-LSD binding were found in the frontal cortex, olfactory tubercles, extra-frontal cortex and striatum while the lowest level was found in the cerebellum. Binding was saturable in the frontal cortex but increased linearly in the cerebellum with increasing doses of /sup 125/I-LSD. Serotonergic compounds potently inhibited /sup 125/I-LSD binding in cortical regions, olfactory tubercles, and hypothalamus but had no effect in the cerebellum. Dopaminergic compounds caused partial inhibition of binding in the striatum while adrenergic compounds were inactive. From these studies the authors conclude that /sup 125/I-LSD labels serotonin 5-HT/sub 2/ receptor sites in cortical regions with no indication that other receptor sites are labeled. In the olfactory tubercles and hypothalamus, /sup 125/I-LSD labeling occurs predominantly or entirely at serotonic 5-HT/sub 2/ sites. In the striatum, /sup 125/I-LSD labels approximately equal proportions of serotonergic and dopaminergic sites. These data indicate that /sup 125/I-LSD labels serotonin receptors in vivo and suggests that appropriate derivatives of 2I-LSD may prove useful for tomographic imaging of serotonin 5-HT/sub 2/ receptors in the mammalian cortex.

  2. 125I particle implantation combined with chemoradiotherapy to treat advanced pancreatic cancer

    PubMed Central

    Guo, J-M; Jiang, H-T; Di, X-Y; Zhu, Y

    2014-01-01

    Objective: To evaluate the therapy effects of 125I implantation combined with chemoradiotherapy on pancreatic cancer patients. Methods: 30 patients with Stage III or IV pancreatic cancer were equally divided into two groups (control and treatment group). The patients in the treatment group (nine males, six females) received chemotherapy in the first week and 125I implantation in the third week, followed by combined chemoradiotherapy in the fifth week. The patients in the control group (10 males, 5 females) received the same treatment except 125I implantation. The therapy in the control group and treatment group was repeated every 4 weeks. Results: The median conformal radiotherapy dose in the treatment group (30.62 Gy) was significantly lower than that in the control group (47.86 Gy). The total radiation dose was 88.71 ± 27.39 Gy, and the surface activity was 0.6 mCi in the treatment group. After treatment, the average tumour size decreased both in the treatment group [9.17 cm2, 95% confidence interval (CI): 5.60–12.74, p < 0.001] and in the control group (4.54 cm2, 95% CI: 2.74–6.35, p < 0.001). The median survival time in the treatment group was 14 months (95% CI: 12.215–14.785) and in the control group was 12 months (95% CI: 10.884–13.116). There was no statistical significance in survival rates between the two groups (χ2 = 0.908, p = 0.341). Conclusion: 125I implanted into tumour combined with chemoradiotherapy has higher local control rate of advanced pancreatic cancer than chemoradiotherapy. Advances in knowledge: We combined chemoradiotherapy with 125I implantation to treat advanced pancreatic cancer and obtained a higher local control rate and better quality of life than when using chemoradiatherapy alone. PMID:24625042

  3. Phantom size in brachytherapy source dosimetric studies.

    PubMed

    Pérez-Calatayud, J; Granero, D; Ballester, F

    2004-07-01

    An important point to consider in a brachytherapy dosimetry study is the phantom size involved in calculations or experimental measurements. As pointed out by Williamson [Med. Phys. 18, 776-786 (1991)] this topic has a relevant influence on final dosimetric results. Presently, one-dimensional (1-D) algorithms and newly-developed 3-D correction algorithms are based on physics data that are obtained under full scatter conditions, i.e., assumed infinite phantom size. One can then assume that reference dose distributions in source dosimetry for photon brachytherapy should use an unbounded phantom size rather than phantom-like dimensions. Our aim in this paper is to study the effect of phantom size on brachytherapy for radionuclide 137Cs, 192Ir, 125I and 103Pd, mainly used for clinical purposes. Using the GEANT4 Monte Carlo code, we can ascertain effects on derived dosimetry parameters and functions to establish a distance dependent difference due to the absence of full scatter conditions. We have found that for 137Cs and 192Ir, a spherical phantom with a 40 cm radius is the equivalent of an unbounded phantom up to a distance of 20 cm from the source, as this size ensures full scatter conditions at this distance. For 125I and 103Pd, the required radius for the spherical phantom in order to ensure full scatter conditions at 10 cm from the source is R = 15 cm. A simple expression based on fits of the dose distributions for various phantom sizes has been developed for 137Cs and 192Ir in order to compare the dose rate distributions published for different phantom sizes. Using these relations it is possible to obtain radial dose functions for unbounded medium from bounded phantom ones. PMID:15305460

  4. Verification of I-125 brachytherapy source strength for use in radioactive seed localization procedures.

    PubMed

    Metyko, John; Erwin, William; Landsberger, Sheldon

    2016-06-01

    A general-purpose nuclear medicine dose calibrator was assessed as a potential replacement for a dedicated air-communicating well-type ionization chamber (brachytherapy source strength verification instrument) for (125)I seed source strength verification for radioactive seed localization, where less stringent accuracy tolerances may be acceptable. The accuracy, precision and reproducibility of the dose calibrator were measured and compared to regulatory requirements. The results of this work indicate that a dose calibrator can be used for (125)I seed source strength verification for radioactive seed localization. PMID:27015651

  5. Preventive effects of 125I seeds on benign restenosis following esophageal stent implantation in a dog model

    PubMed Central

    GAN, ZHEN; JING, JIAN; ZHU, GUANGYU; QIN, YONGLIN; TENG, GAOJUN; GUO, JINHE

    2015-01-01

    The present study aimed to evaluate the effects of iodine-125 (125I) seeds on the proliferation of primary esophageal fibroblasts in dogs, and to assess the safety and preventive efficacy of 125I seed-pre-loaded esophageal stents in benign restenosis following implantation. Primary fibroblasts were cultured with various 125I seed activities, which were then evaluated using cell proliferation and apoptosis assays as well as cell cycle analysis using Annexin V/propidium iodide (PI) double staining and PI staining. Prior to sacrification, animals were submitted to esophageal radiography under digital subtraction angiography. Esophageal tissues were collected and examined for macroscopic, microscopic and pathological alterations. The results demonstrated a significant and dose-dependent inhibition of fibroblast proliferation and increased apoptosis following exposure to 125I seeds. G0/G1 fibroblast populations increased in a dose-dependent manner following treatment with 125I seeds, in contrast to cells in S phase. Four weeks following implantation, α-smooth muscle actin and proliferating cell nuclear antigen expression levels in the experimental group were significantly lower compared with those in the control group; in addition, eight weeks following implantation, esophageal inner diameters were increased in the experimental group. 125I seeds inhibited proliferation of dog esophageal fibroblasts via cell cycle arrest and apoptosis. In conclusion, 125I seed-pre-loaded esophageal stents inhibited benign hyperplasia in the upper edge of the stent to a certain extent, which relieved benign restenosis following implantation with a good safety profile. PMID:25543838

  6. Sequential Comparison of Seed Loss and Prostate Dosimetry of Stranded Seeds With Loose Seeds in {sup 125}I Permanent Implant for Low-Risk Prostate Cancer

    SciTech Connect

    Saibishkumar, Elantholi P.; Borg, Jette; Yeung, Ivan; Cummins-Holder, Cheryl; Landon, Angela; Crook, Juanita

    2009-01-01

    Purpose: To compare stranded seeds (SSs) with loose seeds (LSs) in terms of prostate edema, dosimetry, and seed loss after {sup 125}I brachytherapy. Methods and Materials: Two prospective cohorts of 20 men participated in an institutional review board-approved protocols to study postimplant prostate edema and its effect on dosimetry. The LS cohort underwent brachytherapy between September 2002 and July 2003 and the SS cohort between April 2006 and January 2007. Both cohorts were evaluated sequentially using computed tomography-magnetic resonance imaging fusion-based dosimetry on Days 0, 7, and 30. No hormonal therapy or supplemental beam radiotherapy was used. Results: Prostate edema was less in the SS cohort at all points (p = NS). On Day 0, all the prostate dosimetric factors were greater in the LS group than in the SS group (p = 0.003). However, by Days 7 and 30, the dosimetry was similar between the two cohorts. No seeds migrated to the lung in the SS cohort compared with a total of five seeds in 4 patients in the LS cohort. However, the overall seed loss was greater in the SS cohort (24 seeds in 6 patients; 1.1% of total vs. 0.6% for LSs), with most seeds lost through urine (22 seeds in 5 patients). Conclusion: Despite elimination of venous seed migration, greater seed loss was observed with SSs compared with LSs, with the primary site of loss being the urinary tract. Modification of the technique might be necessary to minimize this. Prostate dosimetry on Days 7 and 30 was similar between the SS and LS cohorts.

  7. Specific uptake, dissociation, and degradation of /sup 125/I-labeled insulin in isolated turtle (Chrysemys dorbigni) thyroid glands

    SciTech Connect

    Marques, M.; da Silva, R.S.; Turyn, D.; Dellacha, J.M.

    1985-11-01

    Thyroid glands from turtles (Chrysemys dorbigni) pretreated with potassium iodide were incubated with /sup 125/I-insulin in the presence or absence of unlabeled insulin, in order to study its specific uptake. At 24 degrees, the specific uptake reached a plateau at 180 min of incubation. The dose of bovine insulin that inhibited 50% of the /sup 125/I-insulin uptake was 2 micrograms/ml of incubation medium. Most of the radioactive material (71%) extracted from the gland, after 30 min incubation with /sup 125/I-insulin, eluted in the same position as labeled insulin on Sephadex G-50. Only 24% eluted in the salt position. After 240 min incubation, increased amount of radioactivity appeared in the Na/sup 125/I position. When bovine insulin was added together with the labeled hormone, a substantial reduction of radioactivity was observed in the insulin and Na/sup 125/I elution positions. Dissociation studies were performed at 6 degrees in glands preincubated with /sup 125/I-insulin either at 24 or 6 degrees. The percentage of trichloroacetic acid (TCA)-soluble radioactive material in the dissociation medium increased with incubation time at both temperatures. However, the degradation activity was lower at 6 than at 24 degrees. The addition of bovine insulin to the incubation buffer containing /sup 125/I-insulin reduced the radioactive degradation products in the dissociated medium. Chloroquine or bacitracin inhibited the degradation activity. Incubation of thyroid glands with /sup 125/I-hGH or /sup 125/I-BSA showed values of uptake, dissociation, and degradation similar to those experiments in which an excess of bovine insulin was added together with the labeled hormone. Thus, by multiple criteria, such as specific uptake, dissociation, and degradation, the presence of insulin-binding sites in the turtle thyroid gland may be suggested.

  8. Retrograde axonal transport of /sup 125/I-nerve growth factor in rat ileal mesenteric nerves. Effect of streptozocin diabetes

    SciTech Connect

    Schmidt, R.E.; Plurad, S.B.; Saffitz, J.E.; Grabau, G.G.; Yip, H.K.

    1985-12-01

    The retrograde axonal transport of intravenously (i.v.) administered /sup 125/I-nerve growth factor (/sup 125/I-NGF) was examined in mesenteric nerves innervating the small bowel of rats with streptozocin (STZ) diabetes using methods described in detail in the companion article. The accumulation of /sup 125/I-NGF distal to a ligature on the ileal mesenteric nerves of diabetic animals was 30-40% less than in control animals. The inhibition of accumulation of /sup 125/I-NGF in diabetic animals was greater at a ligature tied 2 h after i.v. administration than at a ligature tied after 14 h, which suggests that the diabetic animals may have a lag in initiation of NGF transport in the terminal axon or retardation of transport at some site along the axon. The /sup 125/I-NGF transport defect was observed as early as 3 days after the induction of diabetes, a time before the development of structural axonal lesions, and did not worsen at later times when dystrophic axonopathy is present. Both the ileal mesenteric nerves, which eventually develop dystrophic axonopathy in experimental diabetes, and the jejunal mesenteric nerves, which never develop comparable structural alterations, showed similar /sup 125/I-NGF transport deficits, suggesting that the existence of the transport abnormality does not predict the eventual development of dystrophic axonal lesions. Autoradiographic localization of /sup 125/I-NGF in the ileal mesenteric nerves of animals that had been diabetic for 11-13 mo demonstrated decreased amounts of /sup 125/I-NGF in transit in unligated paravascular nerve fascicles. There was, however, no evidence for focal retardation of transported /sup 125/I-NGF at the sites of dystrophic axonal lesions.

  9. Derivatives of cyclosporin compatible with antibody-based assays. I. The generation of (/sup 125/I)-labeled cyclosporin

    SciTech Connect

    Mahoney, W.C.; Orf, J.W.

    1985-03-01

    The immunosuppressive drug cyclosporin A, has been successfully iodinated to a specific activity of 300 Ci per gram. /sup 125/I-labeled cyclosporin and (/sup 3/H)cyclosporin are nearly equivalent as tracers in a radioimmunoassay in producing standard lines (suppression by unlabeled cyclosporin) and in assigning values to clinical samples. In addition, the (/sup 125/I)-labeled cyclosporin has greater than twice the sensitivity, and it is stable to long-term storage. Use of a (/sup 125/I)-labeled cyclosporin tracer is more convenient, more reproducible, more precise, and easier than the tritiated-cyclosporin alternative in radioimmunoassay of this compound.

  10. Determination of {sup 125}I and {sup 131}I in radioisotope wastes

    SciTech Connect

    Sang Hoon Kang; Ke Chon Choi; Lee, Heung N.; Sun Ho Han; Kwang Yong Jee

    2007-07-01

    In order to measure a low activity of {sup 125}I and {sup 131}I in radioisotope wastes, we took into consideration various sample preparation and separation methods, such as an acid decomposition, an acid leaching and a combustion method. In a previous study, the maximum chemical yield of iodine by an acid leaching was found to be 78.0 %. However, in this study, the maximum chemical yield of the acid decomposition method and the combustion method with a radioiodine reference solution was found to be 99.1 % and 84.5 %, respectively. We selected the acid decomposition method for the analysis of radioisotope waste samples due to its high chemical yield and short preparation and separation time. The chemical yield of the acid decomposition method depends on the reaction time at each experimental stage, added amount of H{sub 3}PO{sub 3} and H{sub 2}O{sub 2}, and the pH of the condensed solution and the condition of the AgI precipitation. The important point for the highest recovery rate from a acid decomposition method is to maintain enough reaction time and pour 10 ml of 30 % H{sub 3}PO{sub 3} before a distillation, and drop 1 ml of H{sub 2}O{sub 2} when the condensed solution is trapped in the Florence flask. Through a study of the acid decomposition method we found an optimal preparation and separation method of {sup 125}I and {sup 131}I in radioisotope wastes due to the merits of a short reaction time and high recovery rate, and a counting system was applied to LEPS for the {sup 125}I and HP Ge gamma-ray spectrometer for {sup 131}I. (authors)

  11. Testicular shielding in penile brachytherapy

    PubMed Central

    Bindal, Arpita; Tambe, Chandrashekhar M.; Ghadi, Yogesh; Murthy, Vedang; Shrivastava, Shyam Kishore

    2015-01-01

    Purpose Penile cancer, although rare, is one of the common genitourinary cancers in India affecting mostly aged uncircumcised males. For patients presenting with small superficial lesions < 3 cm restricted to glans, surgery, radical external radiation or brachytherapy may be offered, the latter being preferred as it allows organ and function preservation. In patients receiving brachytherapy, testicular morbidity is not commonly addressed. With an aim to minimize and document the doses to testis after adequate shielding during radical interstitial brachytherapy for penile cancers, we undertook this study in 2 patients undergoing brachytherapy and forms the basis of this report. Material and methods Two patients with early stage penile cancer limited to the glans were treated with radical high-dose-rate (HDR) brachytherapy using interstitial implant. A total of 7-8 tubes were implanted in two planes, parallel to the penile shaft. A total dose of 44-48 Gy (55-60 Gy EQD2 doses with α/β = 10) was delivered in 11-12 fractions of 4 Gy each delivered twice daily. Lead sheets adding to 11 mm (4-5 half value layer) were interposed between the penile shaft and scrotum. The testicular dose was measured using thermoluminescent dosimeters. For each patient, dosimetry was done for 3 fractions and mean calculated. Results The cumulative testicular dose to left and right testis was 31.68 cGy and 42.79 cGy for patient A, and 21.96 cGy and 23.28 cGy for patient B. For the same patients, the mean cumulative dose measured at the posterior aspect of penile shaft was 722.15 cGy and 807.72 cGy, amounting to 16.4% and 16.8% of the prescribed dose. Hence, the application of lead shield 11 mm thick reduced testicular dose from 722-808 cGy to 21.96-42.57 cGy, an “absolute reduction” of 95.99 ± 1.5%. Conclusions With the use of a simple lead shield as described, we were able to effectively reduce testicular dose from “spermicidal” range to “oligospermic” range with possible

  12. Interstitial keratitis

    MedlinePlus

    ... cornea. This condition is often caused by infections. Syphilis is the most common cause of interstitial keratitis, ... Tuberculosis In the United States, most cases of syphilis are recognized and treated before this eye condition ...

  13. Ocular penetration of (/sup 125/I)IVDU, a radiolabeled analogue of bromovinyldeoxyuridine

    SciTech Connect

    Maudgal, P.C.; Verbruggen, A.M.; De Clercq, E.; Busson, R.; Bernaerts, R.; de Roo, M.; Ameye, C.; Missotten, L.

    1985-01-01

    Following topical application of (/sup 125/)IVDU, the radiolabeled analogue of bromovinyldeoxyuridine ((E)-5-(2-bromovinyl)-2'-deoxyuridine), as 0.5% or 0.3% eyedrops, to rabbits, (/sup 125/I)IVDU appeared in the anterior chamber fluid at drug levels well above the minimum concentration (0.01 microgram/mL) required for inhibition of herpes simplex virus type 1 replication. These findings are consistent with the efficacy of 0.5% bromovinyldeoxyuridine eyedrops in the topical treatment of herpes simplex uveitis.

  14. Rapid extraction, radioiodination, and in vivo catabolism of 125I-labeled fibrinogen in the horse

    SciTech Connect

    Coyne, C.P.; Hornof, W.J.; Kelly, A.B.; O'Brien, T.R.; DeNardo, S.J.

    1985-12-01

    Two methods were analyzed for the rapid extraction of equine fibrinogen from fresh plasma, using ammonium sulfate-sodium phosphate buffer. Fibrinogen from each of these 2 methods was then radiolabeled with 125I (half-life = 60.2 days, gamma = 35 keV), using monochloroiodine reagent. Mean protein-bound activity was 98.5% and mean clottable radioactivity was 94.1%. Radiolabeled fibrinogen administered IV to 15 horses had an overall mean (+/- SD) plasma half-life of 4.95 +/- 0.44 days.

  15. Scintillation Studies of the Mouse Mammary Tumor Virus with ^125I

    NASA Astrophysics Data System (ADS)

    Yazdi, Amir; Blue, Eric; Bradley, Eric; Majewski, Stan; Mohammed, Shira; Qian, Jianguo; Saha, Margaret; Schworer, Stephen; Sutton, Jonathan; Weisenberger, Andrew; Welsh, Robert

    2007-10-01

    We have applied the techniques of scintillation imaging to studies of the mouse mammary tumor virus (MMTV). In these studies, Sodium Iodide Symporter (NIS) transfers the radioactive ^125I to the mammary glands of lactating mice and in particular to those mammaries with visible tumors. These studies have principally been carried out using pixellated scintillators coupled to position sensitive photomultiplier tubes (PSPMTs). More recently, we have initiated such studies with a monolithic slab of LaBr3 scintillator coupled to an array of PSPMTs. Several techniques of mapping and measuring the development of such tumors have been employed. These will be discussed in detail and preliminary results will be reported.

  16. Effects of extracellular acetylcholine on muscarinic receptor binding assessed by [125I]dexetimide and a simple probe.

    PubMed

    Sánchez-Roa, P M; Wagner, H N; Villemagne, V L; London, E D; Lever, J R

    1998-10-01

    New pharmacologic approaches to enhance brain cholinergic function focus on increasing intrasynaptic acetylcholine. We examined the usefulness of a simple probe and [125I]dexetimide to evaluate in vivo the effects of extracellular acetylcholine on muscarinic receptor binding in the mouse brain. After radiotracer injection continuous time/activity curves were generated over 330 min. [125I]Dexetimide reached a plateau at 90 min post-injection. To increase extracellular acetylcholine, the anticholinesterase physostigmine was administered at 120 min, producing a reversible decrease in [125I]dexetimide specific binding (23%) for 30 min. These findings demonstrate that dynamic changes in extracellular acetylcholine can be evaluated by displacement of [125I]dexetimide binding in vivo using a simple probe system. PMID:9822886

  17. (125)I labeling of clomiphene and biodistribution studies for possible use as a model in breast cancer imaging.

    PubMed

    Ibrahim, I T; El-Kolaly, M T; Aboumanei, M H; Abdelbary, A

    2016-09-01

    Clomiphene has growth-inhibitory effects of breast cancer cells, clomiphene was successfully labeled with (125)I via direct electrophilic substitution reaction with labeling yield 97%. It was obtained at optimum substrate amount of 0.5mg, Chloramine-T was used as an oxidizing agent at optimum amount of 25µg. Labeling reactions was done at pH 5 at ambient temperature. This study showed good in vitro and in vivo stability of the (125)I-clomiphene. The radiolabeled compound showed high ascetic fluid uptake of 18.12±0.27% at 30min post-injection. Solid tumor uptake of (125)I-clomiphene was 12.48±0.32% at 30min post-injection. This data revealed the localization of tracer in tumor tissue with high percent sufficient to use (125)I-clomiphene as a promising tool for the diagnosis of breast cancer. PMID:27337647

  18. Interstitial irradiation of brain tumors: a review

    SciTech Connect

    Bernstein, M.; Gutin, P.H.

    1981-12-01

    As an adjuvant to surgery, radiation therapy has consistently proven to be the most successful form of treatment for primary and secondary malignant brain tumors and possibly for inoperable benign tumors. Because the risk of radiation necrosis of normal brain limits the amount of radiation that can be given by external beam therapy at conventional dose rates, interstitial radiation of brain tumors is a logical alternative treatment approach. We discuss the radiobiological advantages of low dose rate irradiation and intratumoral placement of sources that make interstitial irradiation an attractive treatment for brain tumors and review the history of clinical brachytherapy for intracranial neoplasia.

  19. Autoradiographic localization of (/sup 125/I)-angiotensin II binding sites in the rat adrenal gland

    SciTech Connect

    Healy, D.P.; Maciejewski, A.R.; Printz, M.P.

    1985-03-01

    To gain greater insight into sites of action of circulating angiotensin II (Ang II) within the adrenal, we have localized the (/sup 125/I)-Ang II binding site using in vitro autoradiography. Autoradiograms were generated either by apposition of isotope-sensitive film or with emulsion-coated coverslips to slide-mounted adrenal sections labeled in vitro with 1.0 nM (/sup 125/I)-Ang II. Analysis of the autoradiograms showed that Ang II binding sites were concentrated in a thin band in the outer cortex (over the cells of the zona glomerulosa) and in the adrenal medulla, which at higher power was seen as dense patches. Few sites were evident in the inner cortex. The existence of Ang II binding sites in the adrenal medulla was confirmed by conventional homogenate binding techniques which revealed a single class of high affinity Ang II binding site (K/sub d/ . 0.7nM, B/sub max/ . 168.7 fmol/mg). These results suggest that the adrenal medulla may be a target for direct receptor-mediated actions of Ang II.

  20. Immunoassay using /sup 125/I- or enzyme-labeled protein A and antigen-coated tubes

    SciTech Connect

    Gee, A.P.; Langone, J.J.

    1981-09-15

    Antigen-coated plastic tubes were used with /sup 125/I- or enzyme-labeled stapylococcal protein A in a general immunoassay method for antigens and haptens. Protein A reacts with immunoglobulin G(IgG) regardless of antibody specificity at sites distal to the antigen combining site and does not inhibit the immune reaction. It therefore serves as a general tracer and its use eliminates the need to purify and to label individual components for each assay. Macromolecular antigens were bound to polystyrene or polypropylene tubes by direct passive absorption. Haptens with free carboxyl groups were bound covalently to poly-L-lysine and these conjugates passively absorbed to the tube surface. Optimal assay conditions were established for the quantitative determination of immunoglobulins and the folate derivatives, methotrexate and 5-methyltetrahydrofolate, using /sup 125/I-labeled protein A or protein A labeled with alkaline phosphatase. The method has been used to estimate levels of IgG, IgA, Igm, and IgE in serum in volumes up to 1 ml.

  1. Autoradiographic distribution of /sup 125/I-galanin binding sites in the rat central nervous system

    SciTech Connect

    Skofitsch, G.; Sills, M.A.; Jacobowitz, D.M.

    1986-11-01

    Galanin (GAL) binding sites in coronal sections of the rat brain were demonstrated using autoradiographic methods. Scatchard analysis of /sup 125/I-GAL binding to slide-mounted tissue sections revealed saturable binding to a single class of receptors with a Kd of approximately 0.2 nM. /sup 125/I-GAL binding sites were demonstrated throughout the rat central nervous system. Dense binding was observed in the following areas: prefrontal cortex, the anterior nuclei of the olfactory bulb, several nuclei of the amygdaloid complex, the dorsal septal area, dorsal bed nucleus of the stria terminalis, the ventral pallidum, the internal medullary laminae of the thalamus, medial pretectal nucleus, nucleus of the medial optic tract, borderline area of the caudal spinal trigeminal nucleus adjacent to the spinal trigeminal tract, the substantia gelatinosa and the superficial layers of the dorsal spinal cord. Moderate binding was observed in the piriform, periamygdaloid, entorhinal, insular cortex and the subiculum, the nucleus accumbens, medial forebrain bundle, anterior hypothalamic, ventromedial, dorsal premamillary, lateral and periventricular thalamic nuclei, the subzona incerta, Forel's field H1 and H2, periventricular gray matter, medial and superficial gray strata of the superior colliculus, dorsal parts of the central gray, peripeduncular area, the interpeduncular nucleus, substantia nigra zona compacta, ventral tegmental area, the dorsal and ventral parabrachial and parvocellular reticular nuclei. The preponderance of GAL-binding in somatosensory as well as in limbic areas suggests a possible involvement of GAL in a variety of brain functions.

  2. Autoradiographic localization of (/sup 125/I-Tyr4)bombesin-binding sites in rat brain

    SciTech Connect

    Zarbin, M.A.; Kuhar, M.J.; O'Donohue, T.L.; Wolf, S.S.; Moody, T.W.

    1985-02-01

    The binding of (/sup 125/I-Tyr/sub 4/)bombesin to rat brain slices was investigated. Radiolabeled (Tyr/sub 4/)bombesin bound with high affinity (K/sub d/ . 4 nM) to a single class of sites (B/sub max/ . 130 fmol/mg of protein); the ratio of specific to nonspecific binding was 6/1. Also, pharmacology studies indicated that the C-terminal of bombesin was important for the high affinity binding activity. Autoradiographic studies indicated that the (/sup 125/I-Tyr4)bombesin-binding sites were discretely distributed in certain gray but not white matter regions of rat brain. Highest grain densities were present in the olfactory bulb and tubercle, nucleus accumbens, suprachiasmatic and periventricular nuclei of the hypothalamus, central medial thalamic nucleus, medial amygdaloid nucleus, hippocampus, dentate gyrus, subiculum, nucleus of the solitary tract, and substantia gelatinosa. Moderate grain densities were present in the parietal cortex, deep layers of the neocortex, rhinal cortex, caudate putamen, stria terminalis, locus ceruleus, parabrachial nucleus, and facial nucleus. Low grain densities were present in the globus pallidus, lateral thalamus, and midbrain. Negligible grain densities were present in the cerebellum, corpus callosum, and all regions treated with 1 microM unlabeled bombesin. The discrete regional distribution of binding suggests that endogenous bombesin-like peptides may function as important regulatory agents in certain brain loci.

  3. Dose optimization in 125I permanent prostate seed implants using the Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Reis, Juraci P.; Menezes, Artur F.; Souza, Edmilson M.; Facure, Alessandro; Medeiros, Jose A. C. C.; Silva, Ademir X.

    2012-04-01

    The aim of this work consisted in using the Monte Carlo code MCNP and computational phantoms to assess the absorbed dose distributions in the prostate, due to a radiotherapy treatment using 125I radioactive seeds. The intention was to develop a tool that can serve as a complement of the treatment planning system of radiotherapy procedures, reproducing accurately the exact geometry of the sources and the composition of the media where the seeds are inserted. The radiation activities of the simulated seeds varied from 0.27 mCi to 0.38 mCi, for hypothetical treatments employing 80, 88 or 100 125I sources, typical parameters for this technique. The prostate volumes where the seeds were virtually inserted were simulated with spherical or voxel computational phantoms. The configuration containing 88 seeds with initial radiation activity of 0.27 mCi resulted in a final absorbed dose near 144 Gy, in accordance with the recommendations of the American Association of Physicists in Medicine (AAPM). Based on this configuration, it was possible to obtain the radiation absorbed dose distributions for the voxel phantom, which allowed the determination of treatment quality indicators. The obtained results are in good agreement with experimental data presented by other authors.

  4. Heterogeneity in mouse seminal vesicle epithelial cells responding to androgen as evaluated by incorporation of (/sup 125/I)iododeoxyuridine

    SciTech Connect

    Terada, N.; Ogasawara, Y.; Yamane, T.; Matsumoto, K.; Kitamura, Y.

    1985-04-01

    When the uptake of 5-(/sup 125/I)iodo-2'-deoxyuridine ((/sup 125/I)IdUrd) into the seminal vesicle of castrated mice was measured 3 days after starting injections of various doses of testosterone propionate (TP), logarithmic values of (/sup 125/I)IdUrd uptake were proportional to the logarithmic doses of TP in the range of 0.04-2 micrograms/g BW. The (/sup 125/I)IdUrd uptake values correlated well with the labeling and mitotic indices of epithelial cells. Since daily injections of 0.4 microgram TP/g BW did not increase significantly the weight or DNA content or protein content of the seminal vesicle, the (/sup 125/I)IdUrd uptake is a sensitive index of androgen action. Moreover, this suggests that low doses of androgen induce division of epithelial cells without resulting in the increase in cell number. The (/sup 125/I)IdUrd radioactivity in the seminal vesicle was measured 2-15 days after the injection of (/sup 125/I)IdUrd, since the value represented the fraction of surviving cells synthesizing DNA at the time of (/sup 125/I)IdUrd injection. When injections of 4 micrograms TP/g BW were continued, the incorporated radioactivity was retained. In contrast, continuous injections of 0.2 microgram TP/g BW did not maintain the radioactivity, of which incorporation was induced by the same dose of TP. Thus, the present result suggests the presence of heterogeneity in androgen-responsive epithelial cells of the seminal vesicle.

  5. Computed tomography fluoroscopy-guided percutaneous 125I seed implantation for safe, effective and real-time monitoring radiotherapy of inoperable stage T1-3N0M0 non-small-cell lung cancer

    PubMed Central

    LI, JIAKAI; YU, MIAO; XIAO, YUEYONG; YANG, LI; ZHANG, JINSHAN; RAY, ERIK; YANG, XIAOMING

    2013-01-01

    The management of inoperable lung cancer remains a challenge. It has been proven that computed tomography (CT)-guided iodine-125 (125I) seed implantation is a safe and efficient method for treating lung cancer. Computed tomographic fluoroscopy (CTF) is superior to traditional CT for percutaneous management of lung lesions, due to the real-time guidance and accurate localization of the lesions. The aim of the present prospective study was to evaluate the feasibility, safety and efficacy of CTF-guided percutaneous permanent implantation of 125I seeds for the treatment of selected patients with inoperable stage T1-3N0M0 non-small-cell lung cancer (NSCLC). A total of 24 patients with resectable but inoperable stage T1-3N0 NSCLC, with a total of 28 lesions, underwent CTF-guided percutaneous implantation of radioactive 125I seeds. A prescription dose of 100–120 Gy was delivered to each lesion. The complications and local tumor control rates were documented. Survival was estimated using the Kaplan-Meier method. All the patients successfully completed the procedure, with a mean procedure duration of 45.7 min (range, 30–75 min). No severe complications occurred. Small asymptomatic pneumothorax with lung volume compression of <10% and minor hemorrhage along the needle track without hemoptysis occurred immediately after the procedure in 3 (12.5%) and 4 (16.7%) of the 24 patients, respectively. At a median follow-up of 31.5 months (range, 8–46 months), the local control rate (LCR) of the lesions was 78.6% (22/28). The 1-, 2- and 3-year overall survival rate was 95.8, 78 and 55%, respectively. In conclusion, CTF is the favourable imaging guidance method for the percutaneous implantation of 125I seeds. CTF-guided brachytherapy with implantation of 125I seeds is a safe, feasible and effective modality for the treatment of inoperable early-stage NSCLC and may be considered an alternative option in selected patients with medically inoperable NSCLC. PMID:24649287

  6. Autoradiographic characterization of (+-)-1-(2,5-dimethoxy-4-( sup 125 I) iodophenyl)-2-aminopropane (( sup 125 I)DOI) binding to 5-HT2 and 5-HT1c receptors in rat brain

    SciTech Connect

    Appel, N.M.; Mitchell, W.M.; Garlick, R.K.; Glennon, R.A.; Teitler, M.; De Souza, E.B. )

    1990-11-01

    The 5-HT2 (serotonin) receptor has traditionally been labeled with antagonist radioligands such as (3H)ketanserin and (3H)spiperone, which label both agonist high-affinity (guanyl nucleotide-sensitive) and agonist low-affinity (guanyl nucleotide-insensitive) states of this receptor. The hallucinogen 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) is an agonist which labels the high-affinity guanyl nucleotide-sensitive state of brain 5-HT2 receptors selectively. In the present study, conditions for autoradiographic visualization of (+/-)-(125I)DOI-labeled 5-HT2 receptors were optimized and binding to slide-mounted sections was characterized with respect to pharmacology, guanyl nucleotide sensitivity and anatomical distribution. In slide-mounted rat brain sections (+/-)-(125I)DOI binding was saturable, of high affinity (KD approximately 4 nM) and displayed a pharmacologic profile typical of 5-HT2 receptors. Consistent with coupling of 5-HT2 receptors in the high-affinity state to a guanyl nucleotide regulatory protein, (125I)DOI binding was inhibited by guanyl nucleotides but not by adenosine triphosphate. Patterns of autoradiographic distribution of (125I)DOI binding to 5-HT2 receptors were similar to those seen with (3H)ketanserin- and (125I)-lysergic acid diethylamide-labeled 5-HT2 receptors. However, the density of 5-HT2 receptors labeled by the agonist (125I)DOI was markedly lower (30-50%) than that labeled by the antagonist (3H)ketanserin. High densities of (125I)DOI labeling were present in olfactory bulb, anterior regions of cerebral cortex (layer IV), claustrum, caudate putamen, globus pallidus, ventral pallidum, islands of Calleja, mammillary nuclei and inferior olive. Binding in hippocampus, thalamus and hypothalamus was generally sparse.

  7. Adjuvant brachytherapy in the treatment of soft-tissue sarcomas.

    PubMed

    Crownover, R L; Marks, K E

    1999-06-01

    For many patients with STS, administering adjuvant radiation treatments in the form of interstitial brachytherapy provides an excellent alternative to a protracted course of EBRT. Ideal patients are those with intermediate- or high-grade tumors amenable to en bloc resection. Attractive features of this approach include an untainted pathologic specimen, expeditious completion of treatment, reduction in wound complications, and improved functional outcome. Brachytherapy can permit definitive reirradiation by tightly localizing the high dose radiation exposure. It is also useful in patients who are known to have or be at high risk of metastatic disease, for whom the rapid completion of local treatment allows systemic therapy to begin quickly. Introduction of HDR techniques has shifted the delivery of brachytherapy from inpatient solitary confinement to an outpatient setting. Early reports using HDR brachytherapy for treatment of adult and pediatric STS are quite encouraging. The clinical equivalence between hyperfractionated HDR schedules and traditional LDR techniques is gaining acceptance. PMID:10432432

  8. A novel radiologand [[sup 125]I]BQ-3020 selective for endothelin (ET[sub B]) receptors

    SciTech Connect

    Ihara, Masaki; Saeki, Toshihiko; Fukuroda, Takahiro; Kimura, Sachiyo; Ozaki, Satoshi; Yano, Mitsuo ); Patel, A.C. )

    1992-01-01

    A linear endothelin (ET) analog, N-acetyl-LeuMetAspLysGluAlaValTryPheAlaHisLeuAspIleIleTrp (BQ-3020), is highly selective for ET[sub B] receptors. BQ-3020 displaces [[sup 125]I]ET-1 binding to ET[sub B] receptors in porcine cerebellar membranes at a concentration 4,700 times lower than that of ET[sub A] receptors on aortic vascular smooth muscle cells (VSMC). BQ-3929 as well as ET-1 and ET-3 elicits vasoconstriction in the rabbit pulmonary artery. The ET[sub A] antagonist BB-123 failed to inhibit this BQ-3020-induced vasocontraction. Futhermore, BQ-3929 elicits endothelium-dependent vasodilation. These data indicate that BQ-3020 has ET[sub B]agonistic activity. The radioligand [[sup 125]I]BQ-3020 binds to cerebellar membranes at single high affinity sites, whereas it scarcely binds to VSMC. [[sup 125]I]BQ-3020 binding to the cerebellum was displaced by BQ-3020, ET-1 and ET-3 in a nonselective manner. However, the binding of [[sup 125]I]BQ-3020 was insensitive to the ET[sub A] antagonist BQ-123 and other bioactive peptides. Both [[sup 125]I]ET-1 and [[sup 125]I]BQ-3020 show slow onset and offset binding kinetics to ET[sub B] receptors. These data indicate that the radioligand [[sup 125]I]BQ-3020 selectively labels ET[sub B] receptors and that the slow binding kinetics of ET-1 are dependent on the peptide sequence from Leu[sup 6] to Trp[sup 21], but not on the structure formed by its two disulfide bridges.

  9. Autoradiographic localization of putative nicotinic receptors in the rat brain using sup 125 I-neuronal bungarotoxin

    SciTech Connect

    Schulz, D.W.; Loring, R.H.; Aizenman, E.; Zigmond, R.E. )

    1991-01-01

    Neuronal bungarotoxin (NBT), a snake venom neurotoxin, selectively blocks nicotinic receptors in many peripheral and central neuronal preparations. alpha-Bungarotoxin (alpha BT), on the other hand, a second toxin isolated from the venom of the same snake, is an ineffective nicotinic antagonist in most vertebrate neuronal preparations studied thus far. To examine central nicotinic receptors recognized by NBT, we have characterized the binding of 125I-labeled NBT (125I-NBT) to rat brain membranes and have mapped the distribution of 125I-NBT binding in brain sections using quantitative light microscopic autoradiography. The binding of 125I-NBT was found to be saturable, of high affinity, and heterogeneously distributed in the brain. Pharmacological studies suggested that more than one population of sites is labeled by 125I-NBT. For example, one component of 125I-NBT binding was also recognized by alpha BT, while a second component, not recognized by alpha BT, was recognized by the nicotinic agonist nicotine. The highest densities of these alpha BT-insensitive, nicotine-sensitive sites were found in the fasciculus retroflexus, the lateral geniculate nucleus, the medial terminal nucleus of the accessory optic tract, and the olivary pretectal nucleus. alpha BT-sensitive NBT binding sites were found in highest density in the lateral geniculate nucleus, the subthalamic nucleus, the dorsal tegmental nucleus, and the medial mammillary nucleus (lateral part). The number of brain regions with a high density of 125I-NBT binding sites, blocked either by alpha BT or by nicotine, is low when compared with results obtained using other approaches to studying the central distribution of nicotinic receptors, such as labeling with 3H-nicotine or labeling with cDNA probes to mRNAs coding for putative receptor subunits.

  10. Identification and characterization of alpha 1 adrenergic receptors in the canine prostate using (/sup 125/I)-Heat

    SciTech Connect

    Lepor, H.; Baumann, M.; Shapiro, E.

    1987-11-01

    We have recently utilized radioligand receptor binding methods to characterize muscarinic cholinergic and alpha adrenergic receptors in human prostate adenomas. The primary advantages of radioligand receptor binding methods are that neurotransmitter receptor density is quantitated, the affinity of unlabelled drugs for receptor sites is determined, and receptors can be localized using autoradiography on slide-mounted tissue sections. Recently, (/sup 125/I)-Heat, a selective and high affinity ligand with high specific activity (2200 Ci/mmole) has been used to characterize alpha 1 adrenergic receptors in the brain. In this study alpha 1 adrenergic receptors in the dog prostate were characterized using (/sup 125/I)-Heat. The Scatchard plots were linear indicating homogeneity of (/sup 125/I)-Heat binding sites. The mean alpha 1 adrenergic receptor density determined from these Scatchard plots was 0.61 +/- 0.07 fmol/mg. wet wt. +/- S.E.M. The binding of (/sup 125/I)-Heat to canine prostate alpha 1 adrenergic binding sites was of high affinity (Kd = 86 +/- 19 pM). Steady state conditions were reached following an incubation interval of 30 minutes and specific binding and tissue concentration were linear within the range of tissue concentrations assayed. The specificity of (/sup 125/I)-Heat for alpha 1 adrenergic binding sites was confirmed by competitive displacement assays using unlabelled clonidine and prazosin. Retrospective analysis of the saturation experiments demonstrated that Bmax can be accurately calculated by determining specific (/sup 125/I)-Heat binding at a single ligand concentration. (/sup 125/I)-Heat is an ideal ligand for studying alpha 1 adrenergic receptors in the prostate and its favorable properties should facilitate the autoradiographic localization of alpha 1 adrenergic receptors in the prostate.

  11. (/sup 125/I)Aminobenzyladenosine, a new radioligand with improved specific binding to adenosine receptors in heart

    SciTech Connect

    Linden, J.; Patel, A.; Sadek, S.

    1985-02-01

    The density of adenosine receptors in membranes derived from rat hearts in 25 times lower than the density of receptors in rat brain membranes. Consequently, adenosine radioligands which are useful in brain such as l-(/sup 3/H)phenylisopropyladenosine, (/sup 3/H)cyclohexyladenosine, (/sup 3/H)-2-chloroadenosine and l-(/sup 125/I)hydroxyphenylisopropyladenosine are of limited usefulness in heart, due to a high ratio of nonspecific to specific binding. We have synthesized a new radioligand, (/sup 125/I)-N6-4-aminobenzyladenosine, which binds to rat heart membranes with one-sixth the nonspecific binding of the other radioligands. (/sup 125/I)-N6-4-aminobenzyladenosine bound to rat ventricle membranes with a K/sub D/ equivalent to that of l-(/sup 125/I)hydroxyphenylisopropyladenosine and a B/sub max/ of 15.2 fmol/mg protein. (/sup 125/I)-N6-4-aminobenzyladenosine bound with a higher affinity to brain (K/sub D/ . 1.93 nM) than to heart membranes (K/sub D/ . 11.6 nM). At the radioligand K/sub D/, 60% of the total (/sup 125/I)-N6-4-aminobenzyladenosine bound to heart membranes was specifically bound. Iodination of aminobenzyladenosine increased its affinity for the adenosine receptor by 22-fold, possibly due to a steric or hydrophobic effect of iodine. The new ligand was found to be a full adenosine agonist based on its ability to inhibit cyclic adenosinemonophosphate accumulation in isolated embryonic chick heart cells and rat adipocytes. (/sup 125/I)-N6-4-Aminobenzyladenosine bound to a single affinity site and was displaced from cardiac and brain adenosine receptors by other adenosine analogues with a potency order of l-phenylisopropyladenosine greater than 5'-N-ethylcarboxamide adenosine. These characteristics suggest that the radioligand binds to an Ri adenosine receptor.

  12. Specific /sup 125/I-radioimmunoassay for cholylglycine, a bile acid, in serum

    SciTech Connect

    Miller, P.; Weiss, S.; Cornell, M.; Dockery, J.

    1981-10-01

    The concentration of the conjugated bile acid, cholylglycine, in serum is a sensitive and specific indicator of hepatic function. We describe a convenient, specific, and precise radioimmunoassay for cholylglycine, in which /sup 125/I-labeled cholylglycyltyrosine is used as tracer. In addition, a blocking agent in the buffer system eliminates binding of bile acids to serum albumin. Therefore no extraction is required. We found no interference by (a) abnormal concentrations of albumin or gamma-globulin, (b) lipemic sera, (c) hemolyzed sera, (d) anticoagulants, or (e) various commonly used drugs. The reference interval for fasting subjects is estimated to be 0.0 to 0.6 mg/L. Our clinical studies show that serum cholylglycine concentrations are usually abnormal in most hepatobiliary diseases, such as viral hepatitis, alcoholic liver disease, cirrhosis, and pediatric liver diseases.

  13. Carrier-mediated (/sup 125/I)-T3 uptake by mouse thymocytes

    SciTech Connect

    Centanni, M.; Mancini, G.; Andreoli, M.

    1989-05-01

    Thyroid hormone entry into the thymocyte, a thyroid hormone target, was investigated by incubating the cells with tracer amounts of (/sup 125/I)L-T3. At 37 C T3 uptake was linear with time up to 2 min, and then approached a plateau. The specific T3 uptake, obtained by subtracting the uptake in the presence of excess unlabeled T3, represented 48 +/- 6% of the total at equilibrium. Unlabeled L-T4, D-T3, and triiodothyroacetic acid were less effective than L-T3 in reducing (/sup 125/I)T3 uptake. Kinetic studies on the initial rate of T3 uptake indicated, for the saturable process, a maximum velocity of approximately 1 pmol/10(6) cells.min and a Km of approximately 0.8 nM. Lowering incubation temperature to 4 C resulted in a two thirds reduction of the total T3 uptake. Washout experiments indicated a different hormone release, being more rapid for cells incubated at 4 C than at 37 C; at 30 min 70% of labeled T3 was released when incubation was carried out at 4 C compared to only 35% after incubation at 37 C, indicating the major intracellular location of the hormone at the latter temperature. An energy requirement of T3 uptake in thymocytes was shown by sensitivity to oligomycin; the effect was dose dependent, showing a maximal decrease in specific uptake of 85%. The involvement of cation movement in the entry process of T3 was indicated by the sensitivity to ouabain. These results indicate the existence of a stereospecific, energy-dependent, saturable process for T3 entry in thymocytes.

  14. On-line I-/Te- separation for the AMS analysis of 125I

    NASA Astrophysics Data System (ADS)

    Charles, C. R. J.; Cornett, R. J.; Zhao, X.-L.; Litherland, A. E.; Kieser, W. E.

    2015-10-01

    The isobar separator for anions (ISA) was used together with a 3 MV tandem accelerator mass spectrometer (AMS) to demonstrate the real time (on-line) separation of Te- from I-. Following the ion source mass spectrometry and major retardation to tens of eV, the ISA uses a radiofrequency quadrupole (RFQ) ion guide to confine and direct I- and associated Te- isobar anions through a gas-reaction cell, where chemical reactions occur at eV energies with the electronegative gas NO2. Anions are subsequently reaccelerated out of the ISA to near original ion source extraction energies for AMS analysis. At 5 mTorr NO2 in the ISA gas-reaction cell, 125Te- was observed to be attenuated by a factor of ∼107 as compared to 127I- that did not experience significant (<50%) losses. A comparative test using 37Cl- and 32S- (having similar chemical properties to iodine and tellurium) showed a 32S- attenuation of >107 relative to 37Cl- under the same ISA-AMS conditions. The preferential destruction of Te- (and S-) at eV energies in the ISA is likely due to a larger favorable destruction cross-section with NO2. This study is the first demonstration of I-Te anion separation for AMS, and makes possible the use of 125I, free of the contaminant 125Te isobar after suitable sample purification, for future 129I/125I carrier-free analyses of natural samples at ultra-low trace levels.

  15. (/sup 125/I)diiodoinsulins. Binding affinities, biologic potencies, and properties of their decay products

    SciTech Connect

    Perez Maceda, B.; Linde, S.; Sonne, O.; Gliemann, J.

    1982-07-01

    Insulin was iodinated with 0.3-0.4 mol /sup 125/I/mol insulin using the lactoperoxidase method. About one-third of the radioactivity incorporated into insulin was in diiodoinsulins and about 40% of these molecules contained diiodotyrosine in residue 14 of the A chain. Most of the remaining molecules contained one A14-monoiodotyrosine and one monoiodotyrosine in either position A19, B16, or B26. The binding affinity and biologic potency of this heterogeneous diiodoinsulin preparation was not significantly different from that of A14-(/sup 125/I)monoiodoinsulin in rat adipocytes, whereas it was slightly reduced in hepatocytes and IM-9 lymphocytes. From the iodine distribution and previous data on the binding affinity of each of the four monoiodoinsulin isomers it was calculated that A14-diiodotyrosine-insulin possesses full binding affinity and biologic potency in adipocytes. Diiodoinsulins isolated from another iodoinsulin preparation (iodate method) contained 58% A19-diiodotyrosine-insulin, and most remaining molecules contained one A19-monoiodotyrosine. The binding affinity of this mixed diiodoinsulin preparation was approximately one-fourth of that of A14-monoiodoinsulin in adipocytes, IM-9 lymphocytes, and hepatocytes. It was calculated that A19-diiodotyrosine-insulin is nearly devoid of binding affinity. The diiodoinsulins (lactoperoxidase method) decayed to iodide (probably from diiodotyrosine-insulin) or to polymers with little specific but a markedly increased nonspecific binding. In addition, the polymers had a marked tendency to adsorb to cellulose acetate filters. Conclusions: 1. The binding affinities of diiodoinsulins range from very low values to values at least as high as that of insulin depending on the positions of the iodine moieties. 2. The relative binding affinities vary among tissues. 3. Polymeric decay products give high nonspecific binding.

  16. Permanent and removable implants for the brachytherapy of brain tumors

    SciTech Connect

    Gutin, P.H.; Phillips, T.L.; Hosobuchi, Y.

    1981-10-01

    Thirty-seven patients harboring primary or metastatic brain tumors were treated with 40 implantations of radioactive sources (/sup 192/Ir, /sup 198/Au, or /sup 125/I) using stereotactic neurosurgical techniques. Most tumors had recurred after surgery, whole brain irradiation, and treatment with all feasible chemotherapeutic agents. Sixteen of the 40 implants were pregnant; 24 were mounted in plastic catheters for removal after the desired dose had been delivered. One or more sources were placed in each tumor to deliver 3500-7350 rad to the tumor's periphery for /sup 198/Au, 4,000-12,000 rad for /sup 192/Ir, and 3,000-20,000 rad for /sup 125/I. Three of the six patients treated with /sup 192/Ir had objective responses for 2, 4, and 12 months, and two stabilized for 8 and 11 months. Seven of the 11 patients treated with /sup 198/Au were evaluable: three responded for 3, 5, and 37 + months, one deteriorating patient with a recurrent tumor stabilized for 6 months, and two deteriorated despite treatment. One patient received an interstitial ''boost'' dose with /sup 198/Au after whole brain irradiation and stabilized for 15 months before developing spinal metastases. Six patients received permanent implants with low activity /sup 125/I. Three of these patients had blioblastomas or anaplastic astrocytomas; all continued to deteriorate despite the interstitial irradiation, presumably because the dose rat was too low. One patient with a low-grade astrocytoma (optic chiasm) responded dramatically to permanent, low activity /sup 125/I implants (11 + months). Another (hypothalamic glioma) had a permanent /sup 125/I implant, responded, as was stable at 9 months when external irradiation was administered. One patient with a suprasellar ''teratoid'' tumor stabilized for 10 months.

  17. Long-term follow-up of patients of intrahepatic malignancies treated with Iodine-125 brachytherapy

    SciTech Connect

    Nag, Subir . E-mail: nag.1@osu.edu; DeHaan, Megan; Scruggs, Granger; Mayr, Nina; Martin, Edward W.

    2006-03-01

    Purpose: We investigated the role of intraoperative iodine-125 ({sup 125}I) brachytherapy as a treatment option for unresectable primary and metastatic liver tumors. Methods and Materials: Between 1989 and 2002, 64 patients with unresectable or residual disease after surgical resection for intrahepatic malignancies underwent 160-Gy permanent {sup 125}I brachytherapy. Results: The median length of follow-up was 13.2 years. The overall 1-year, 3-year, and 5-year actuarial intrahepatic local control rates were 44%, 22%, and 22%, respectively, with a median time to liver recurrence of 9 months (95% CI, 6-12 months). The 5-year actuarial intrahepatic control was higher for patients with solitary metastasis (38%) than for those with multiple metastases (6%, p = 0.04). The 1-year, 3-year, and 5-year actuarial overall survival rates were 73%, 23%, and 5%, respectively (median, 20 months; 95% CI, 16-24; longest survival, 7.5 years). Overall survival was higher for patients with smaller-volume implants (p = 0.003) and for patients without prior liver resection (p = 0.002). No mortality occurred. Radiation-related complications were minimal. Conclusions: For select patients with unresectable primary and metastatic liver tumors for whom curative surgical resection is not an option, {sup 125}I brachytherapy is a safe and effective alternative to other locally ablative techniques and can provide long-term local control and increased survival.

  18. Longitudinal Magnetic Resonance Imaging Features of Glioblastoma Multiforme Treated With Radiotherapy With or Without Brachytherapy

    SciTech Connect

    Aiken, Ashley H. Chang, Susan M.; Larson, David; Butowski, Nicholas; Cha, Soonmee

    2008-12-01

    Purpose: To compare temporal patterns of recurrent contrast enhancement in patients with glioblastoma multiforme (GBM) treated with brachytherapy plus external beam radiotherapy (EBRT) vs. EBRT alone. Methods and Materials: We evaluated serial MRI scans for 15 patients who received brachytherapy followed by EBRT (6000 cGy) and 20 patients who received standard EBRT alone (5940-6000 cGy). Brachytherapy consisted of permanent, low-activity {sup 125}I seeds placed around the resection cavity at the time of initial gross total resection. Contrast enhancement (linear, nodular, feathery, or solid), serial progression, and location of contrast enhancement were described. Results: In the EBRT group, 14 patients demonstrated focal nodular contrast enhancement along the resection cavity within 4 months. The 6 remaining EBRT patients developed either transient linear enhancement or no abnormal enhancement. In the brachytherapy plus EBRT group, 7 patients initially developed linear rim enhancement within 4 months that progressed to feathery contrast enhancement over the course of 1 to 2 years. Histopathology confirmed radiation necrosis in all 7 patients. The remaining 8 brachytherapy patients eventually developed focal nodular contrast enhancement along the resection cavity and tumor recurrence. Conclusions: Our data suggest that longitudinal MRI features differ between GBM patients treated with EBRT vs. brachytherapy plus EBRT. In both groups, nodular enhancement adjacent to or remote from the resection cavity strongly suggested tumor recurrence. Feathery enhancement, which progressed from linear rim enhancement immediately adjacent to the cavity, seen only in brachytherapy patients, strongly indicated radiation necrosis.

  19. Distribution of sup 125 I-neurotensin binding sites in human forebrain: Comparison with the localization of acetylcholinesterase

    SciTech Connect

    Szigethy, E.; Quirion, R.; Beaudet, A. )

    1990-07-22

    The distribution of 125I-neurotensin binding sites was compared with that of acetylcholinesterase reactivity in the human basal forebrain by using combined light microscopic radioautography/histochemistry. High 125I-neurotensin binding densities were observed in the bed nucleus of the stria terminalis, islands of Calleja, claustrum, olfactory tubercle, and central nucleus of the amygdala; lower levels were seen in the caudate, putamen, medial septum, diagonal band nucleus, and nucleus basalis of Meynert. Adjacent sections processed for cholinesterase histochemistry demonstrated a regional overlap between the distribution of labeled neurotensin binding sites and that of intense acetylcholinesterase staining in all of the above regions, except in the bed nucleus of the stria terminalis, claustrum, and central amygdaloid nucleus, where dense 125I-neurotensin labeling was detected over areas containing only weak to moderate cholinesterase staining. At higher magnification, 125I-neurotensin-labeled binding sites in the islands of Calleja, supraoptic nucleus of the hypothalamus, medial septum, diagonal band nucleus, and nucleus basalis of Meynert were selectively associated with neuronal perikarya found to be cholinesterase-positive in adjacent sections. Moderate 125I-neurotensin binding was also apparent over the cholinesterase-reactive neuropil of these latter three regions. These data suggest that neurotensin (NT) may directly influence the activity of magnocellular cholinergic neurons in the human basal forebrain, and may be involved in the physiopathology of dementing disorders such as Alzheimer's disease, in which these neurons have been shown to be affected.

  20. Autoradiographic localization of extrastriatal D2-dopamine receptors in the human brain using [125I]epidepride.

    PubMed

    Hall, H; Farde, L; Halldin, C; Hurd, Y L; Pauli, S; Sedvall, G

    1996-06-01

    Epidepride is a benzamide with high affinity for central D2- and D3-dopamine receptors. The anatomical distribution of [125I]epidepride binding was examined by autoradiography, using postmortem human whole-hemisphere cryosections. The density of [125I]epidepride binding sites was high in caudate nucleus and putamen. [125I]epidepride also labeled receptors in extrastriatal region such as in the pallidum, some thalamic nuclei, the neocortex, and the substantia nigra. The neocortical binding was heterogeneously distributed. In most cortical regions, binding sites were located in superficial layers (I-II). However, in basal levels of the occipital cortex, [125I]epidepride binding was located in a deeper layer, probably corresponding to layer V. Competition studies indicated that most of the [125I]epidepride binding represented predominantly D2-dopamine receptors, in striatal as well as in extrastriatal regions. The presence of extrastriatal D2-dopamine receptor populations is of particular interest for research on schizophrenia and antipsychotic drug action. PMID:8723716

  1. Radiobiological effects of /sup 131/I and /sup 125/I on the DNA of the rat thyroid

    SciTech Connect

    Abdel-Nabi, H.; Ortman, J.A.

    1983-03-01

    One of the major disadvantages of the use of /sup 131/I in the treatment of thyrotoxicosis is the development of hypothyroidism. Alternatively, /sup 125/I has been proposed for thyrotoxicosis therapy, and was thought to be preferable to /sup 131/I because of the short range of its emitted soft electrons.Several studies have shown /sup 125/I to be as effective as /sup 131/I in the treatment of thyrotoxicosis, and equally likely to produce hupothyroidism. This work compared the radiobiological effects of /sup 131/I and /sup 125/I given in doses to deliver the same amount of radiation to the rat thyroid gland.These effects were studied by in vivo determination of single-strand DNA breaks by alkaline sucrose gradient sedimentation using the DABA fluorescent technique to detect the DNA. Serum T/sub 4/ and TSH concentrations and percentage T/sub 3/ uptake were determined by RIA. The incidence of hypothyroidism following /sup 131/I and /sup 125/I therapy was found to be the same (10% in each group). The extent of DNA damage following /sup 125/I therapy was greater than the damage induced by a larger dose of /sup 131/I.

  2. Characteristics and autoradiographic localization of 2-( sup 125 I)iodomelatonin binding sites in Djungarian hamster brain

    SciTech Connect

    Duncan, M.J.; Takahashi, J.S.; Dubocovich, M.L. )

    1989-08-01

    These studies investigated the characteristics and regional distribution of 2-({sup 125}I)iodomelatonin binding in Djungarian hamster brain. The results showed that 2-({sup 125}I)iodomelatonin labels two types of binding sites, which resemble the ML-1 and ML-2 melatonin subtypes previously described in other tissues. The 2-({sup 125}I)iodomelatonin binding site identified in whole brain membranes has a nanomolar affinity (Kd = 1.48 +/- 0.26 nM) and biochemical and pharmacological characteristics identical to those of the ML-2 site of Syrian hamster whole brain. The 2-({sup 125}I)iodomelatonin site in the hypothalamus has a picomolar affinity (Kd = 43.4 +/- 5.1 pM) and resembles the ML-1 site of chicken retina. The localization of 2-({sup 125}I)iodomelatonin labeling in autoradiographic studies of the Djungarian hamster brain includes the suprachiasmatic nuclei, the median eminence, the reuniens nucleus, and the paraventricular nucleus of the thalamus.

  3. Dynamic rotating-shield brachytherapy

    SciTech Connect

    Liu, Yunlong; Flynn, Ryan T.; Kim, Yusung; Yang, Wenjun; Wu, Xiaodong

    2013-12-15

    Purpose: To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process.Methods: A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D{sub 90} for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and {sup 192}Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D{sub 2cc} of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with α/β= 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively.Results: For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes/fraction (min/fx) assuming a 10 Ci{sup 192}Ir source, and the average HR-CTV D{sub 90} was 78.9 Gy. In order to match the HR-CTV D{sub 90} of IS + ICBT, D-RSBT required an average of 10.1 min/fx more delivery time, and S-RSBT required 6.7 min/fx more. If an additional 20 min/fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D{sub 90} above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively

  4. /sup 111/In-platelet and /sup 125/I-fibrinogen deposition in the lungs in experimental acute pancreatitis

    SciTech Connect

    Goulbourne, I.A.; Watson, H.; Davies, G.C.

    1987-12-01

    An experimental model of acute pancreatitis in rats has been used to study intrapulmonary /sup 125/I-fibrinogen and /sup 111/In-platelet deposition. Pancreatitis caused a significant increase in wet lung weight compared to normal, and this could be abolished by heparin or aspirin pretreatment. /sup 125/I-fibrinogen was deposited in the lungs of animals to a significantly greater degree than in controls (P less than 0.01). /sup 125/I-fibrinogen deposition was reduced to control levels by pretreatment with aspirin or heparin (P less than 0.05). The uptake of radiolabeled platelets was greater in pancreatitis than in controls (P less than 0.001). Pancreatitis appears to be responsible for platelet entrapment in the lungs. Platelet uptake was reduced by heparin treatment but unaffected by aspirin therapy.

  5. Binding of /sup 125/I-hCG to rainbow trout (Salmo gairdneri) testis in vitro. [Human Chorionic Gonadotropin

    SciTech Connect

    Schlaghecke, R.

    1983-02-01

    Homogenates of maturing rainbow trout testes show specific binding sites for /sup 125/I-labeled hCG (. /sup 125/I-labeled hCG). The binding is competitively inhibited by unlabeled hCG and by a hypophyseal extract of rainbow trout. It could be demonstrated that the tissue /sup 125/I-hCG binding specificity is restricted to the gonadal preparation. The trout testis was characterized by determining affinity and capacity from Scatchard plot analysis giving a high constant of dissociation Kd 3.65 x 10(-10)/M and a low binding capacity of 0.88 x 10(-15) M/mg tissue. The test system is markedly dependent on temperature, incubation-time, and pH. The maximum binding was found at 37 degrees during 2 hr of incubation in a buffer of pH 7.5.

  6. Binding and degradation of /sup 125/I-insulin by renal glomeruli and tubules isolated from rats

    SciTech Connect

    Meezan, E.; Freychet, P.

    1982-04-01

    Isolated rat renal glomeruli and tubules were shown to exhibit specific binding of /sup 125/I-insulin and enzymatic degradation of the hormone. Binding to both renal fractions reached a plateau by 1 h at 22/sup 0/C and increased linearly with increasing protein concentrations. Binding was inhibited in both preparations by insulin and its analogues in the order of relative potency: insulin > despentapeptide insulin > proinsulin, but insulin was ten times more potent in inhibiting /sup 125/I-insulin binding to glomeruli than that to tubules, indicating a different affinity of receptors for the hormone in the two renal fractions (about 17 versus 210 ..mu..g unlabelled insulin/1 inhibiting 50% of the /sup 125/I-insulin binding to glomeruli and tubules, respectively). Bound /sup 125/I-insulin dissociated at a faster rate from tubules than from glomeruli; this release was accelerated by unlabelled insulin in both renal fractions, but to a greater extent in glomeruli than in tubules. Two-thirds of the total bound material released from glomeruli was found to be intact insulin as measured by trichloroacetic acid precipitation, whereas only one-third of the material released from tubules was intact. No direct relationship between binding and degradation of /sup 125/I-insulin in these renal fractions could be demonstrated, however, because of the release of proteolytic enzymes into the incubation medium resulting in almost all degradation being extracellular. Although differing in their affinity for /sup 125/I-insulin the high affinity glomerular insulin receptor and the lower affinity tubular insulin receptor have characteristics similar to those of insulin receptors in insulin responsive tissues.

  7. {sup 125}I Monotherapy Using D90 Implant Doses of 180 Gy or Greater

    SciTech Connect

    Kao, Johnny; Stone, Nelson N.; Lavaf, Amir Dumane, Vishruta; Cesaretti, Jamie A.; Stock, Richard G.

    2008-01-01

    Purpose: The purpose of this study was to characterize the oncologic results and toxicity profile of patients treated with {sup 125}I implants using the dose delivered to 90% of the gland from the dose-volume histogram (D90) of greater than 144 Gy. Methods and Materials: From June 1995 to Feb 2005, a total of 643 patients were treated with {sup 125}I monotherapy for T1-T2 prostate cancer with a D90 of 180 Gy or greater (median, 197 Gy; range, 180-267 Gy). Implantations were performed using a real-time ultrasound-guided seed-placement method and intraoperative dosimetry to optimize target coverage and homogeneity by using modified peripheral loading. We analyzed biochemical disease-free survival (bDFS) of 435 patients who had a minimum 2-year prostate-specific antigen follow-up (median follow-up, 6.7 years; range, 2.0-11.1 years). Results: Five-year bDFS rates for the entire cohort using the American Society for Therapeutic Radiology and Oncology and Phoenix definitions were 96.9% and 96.5%, respectively. Using the Phoenix definition, 5-year bDFS rates were 97.3% for low-risk patients and 92.8% for intermediate/high-risk patients. The positive biopsy rate was 4.1%. The freedom rate from Grade 2 or higher rectal bleeding at 5 years was 88.5%. Acute urinary retention occurred in 10.7%, more commonly in patients with high pretreatment International Prostate Symptom Scores (p < 0.01). In patients who were potent before treatment, 73.4% remained potent at 5 years after implantation. Conclusions: Patients with a minimum D90 of 180 Gy had outstanding local control based on prostate-specific antigen control and biopsy data. Toxicity profiles, particularly for long-term urinary and sexual function, were excellent and showed that D90 doses of 180 Gy or greater performed using the technique described were feasible and tolerable.

  8. Calculation of excitation functions of proton, alpha and deuteron induced reactions for production of medical radioisotopes 122-125I

    NASA Astrophysics Data System (ADS)

    Artun, Ozan; Aytekin, Hüseyin

    2015-02-01

    In this work, the excitation functions for production of medical radioisotopes 122-125I with proton, alpha, and deuteron induced reactions were calculated by two different level density models. For the nuclear model calculations, the Talys 1.6 code were used, which is the latest version of Talys code series. Calculations of excitation functions for production of the 122-125I isotopes were carried out by using the generalized superfluid model (GSM) and Fermi-gas model (FGM). The results have shown that generalized superfluid model is more successful than Fermi-gas model in explaining the experimental results.

  9. Similarities and differences between free 211At and 125I- transport in porcine thyroid epithelial cells cultured in bicameral chambers.

    PubMed

    Lindencrona, U; Nilsson, M; Forssell-Aronsson, E

    2001-01-01

    The transport and accumulation of free 211At and 125I- were investigated in thyrocytes cultured as monolayers in bicameral chambers under the influence of thyroid-stimulating hormone, stable iodide, ouabain and perchlorate. The results indicate that there are similarities and differences in the transport mechanisms of free 211At and 125I-. These results will be valuable in the development of radiation protection when handling and using 211At-labeled radiopharmaceuticals, and for the potential use of free 211At in radiation therapy of poorly differentiated thyroid cancer. PMID:11182563

  10. Formation of iodoprotein during the peripheral metabolism of 35,3′-triiodo-l-thyronine-125I in the euthyroid man and rat

    PubMed Central

    Surks, Martin I.; Oppenheimer, Jack H.

    1969-01-01

    3,5,3′-Triiodo-L-thyronine-125I (T3-125I) metabolism was studied in nine euthyroid human subjects on blocking doses of nonradioactive iodide. After the intravenous injection of T3-125I, the fractional disappearance rate of plasma radioactivity progressively disappearance rate of plasma radioactivity progressively decreased with time. Analysis of individual plasma samples by dialysis, electrophoretic, and extraction techniques revealed three radioactive components: T3-125I, iodide-125I, and an unidentified material which was nonextractable in acid butanol (NE125I). Ne125I rose to maximal levels 24-36 hr after injection of T3-125I and then decreased with a fractional rate which approached, after 12-14 days, approximately 0.05 day-1 (t½ = 14 days). The plasma T3-125I concentration, obtained by subtraction of iodide-125I and NE125I from the plasma total 125I, declined at a constant fractional rate with time with a t½ of 1.5 days. Qualitatively similar results were obtained in rats. After 72 hr, 57% of the plasma and 40% of the liver radioactivity was NE125I. Chromatographic purification of the T3-125I before injection did not alter these results. The extrathyroidal origin of NE125I was further demonstrated by similar results in thyroidectomized rats maintained on thyroxine. NE125I from human sera separated from the other radioiodinated substances by ion-exchange chromatography was quantitatively precipitated by trichloracetic acid, not dialyzable, insoluble in CHCl3:CH2OH, and migrated with albumin during starch-gel electrophoresis. Based on these properties, NE125I was tentatively identified as iodoalbumin. Observations in rats equilibrated with 125I, as well as nonradioactive iodine determinations in human sera before and after acid butanol extraction, indicate that 10-20% of the serum organic iodine is in the form of iodoprotein. Our studies suggest that this moiety may be derived at least in part from the peripheral metabolism of the thyroid hormones. Images

  11. Direct method for detection and characterization of cell surface receptors for insulin by means of 125I-labeled autoantibodies against the insulin receptor.

    PubMed Central

    Jarrett, D B; Roth, J; Kahn, C R; Flier, J S

    1976-01-01

    Autoantibodies directed against the cell surface receptors for insulin are found in some patients with extreme insulin resistance. These antibodies specifically inhibit the binding of insulin to its receptor. A purified IgG fraction from one patient's plasma was labeled with 125I. The 125I-labeled antireceptor antibody, which initially represented about 0.3% of the total 125I-IgG, was enriched by selective adsorption and subsequent elution from cells rich in insulin receptors. The 125I-antireceptor antibody bound to cells and the binding was inhibited by whole plasma and purified IgG from this patient, as well as whole plasma from another patient with autoantibodies to the insulin receptor. Insulins that differed 300-fold in biological potency and affinity inhibited binding of 125I-antireceptor antibody in direct proportion to their ability to bind to the insulin receptor. The binding of 125I-antireceptor antibody was closely correlated with the binding of 125I-insulin over a wide range of receptor concentrations on different cell types. Experimentally induced reduction of the insulin receptor concentration was associated with parallel decreases in the binding of 125I-antireceptor antibody and 125I-insulin. The preparation of 125I-antireceptor antibody with a high specific activity by cytoadsorption and elution has provided a sensitive method for the detection of receptors and autoantibodies to cell surface components. PMID:1069300

  12. The impact of activating source dwell positions outside the CTV on the dose to treated normal tissue volumes in TRUS guided 3D conformal interstitial HDR brachytherapy of prostate cancer

    PubMed Central

    Thunberg, Per; Johansson, Bengt; Persliden, Jan

    2014-01-01

    Purpose Dose coverage is crucial for successful treatment in mono-brachytherapy. Since few and very high dose fractions are used, there is an important balance between dwell positioning outside the clinical target volume (CTV) and possible damage on adjacent normal tissue. The purpose of this study was to evaluate the possibility of having dwell positions close to the CTV surface, while maintaining an acceptable dose distribution, and to investigate the robustness in terms of known geometrical uncertainties of the implant. Material and methods This study included 37 patients who had received brachytherapy for prostate cancer as a monotherapy with the following schedules: 2 × 14 Gy or 3 × 11 Gy, each fraction separated by two weeks. The source dwell positions were activated 5 mm outside CTV. New optimizations were simulated for dwell positions at 3, 2, 1, and 0 mm. Inverse and graphical optimization were applied according to the relative dose constraints: V100 CTV ≥ 97%, Dmax, urethra ≤ 110%, and D10 rectal mucosa ≤ 65%. The V100, normal tissue outside CTV was used to evaluate dose variations caused by different dwell positions. Prostate geometries and dose distributions for the different dwell positions outside the CTV were used to investigate the impact on the CTV dose distribution due to geometrical uncertainties. Results Both V100, CTV, and V100, normal tissue decreased, 98.6% to 92.2%, and 17 cm3 to 9.0 cm3, for dwell activation from 5 mm to 0 mm. The evaluation of both simulated longitudinal geometrical uncertainties and different source dwell activations implied that V100, CTV ranged from 98.6% to 86.3%. Conclusions It is possible to reduce the V100, normal tissue by decreasing the source dwell positions outside the CTV from 5 to 3 mm, while maintaining dose constraints. In combination with the estimated geometrical uncertainties, however, the source dwell positions need to be 5 mm from the surface in order to maintain a robust implant. PMID:25337130

  13. /sup 125/I-hippuran absorption from the human renal pelvis

    SciTech Connect

    Bratt, C.G.; Granerus, G.

    1986-09-01

    The absorption of /sup 125/I-hippuran from human renal pelvis was studied peroperatively in 18 patients with obstruction at the pelviureteric junction. Three types of experiment were included: absorption during induced diuresis, absorption at a constant intrapelvic pressure of 30 cm. H/sub 2/O, and excretion of the indicator by the contralateral kidney. Total and separate glomerular filtration rate were measured using /sup 51/Cr-EDTA clearance technique and isotope renography. Distal tubular function was evaluated as maximum concentration ability. During induced diuresis the intrapelvic pressure increased to an average maximum value of 31.6 cm. H/sub 2/O. The excretion of isotope from the contralateral kidney varied from one to 44% of the given dose. A significant correlation (r = 0.87) between the maximum intrapelvic pressure obtained and the amount of isotope excreted from the contralateral kidney was demonstrated. At a constant intrapelvic pressure of 30 cm. H/sub 2/O the excretion of isotope from the contralateral kidney varied from two to 26% of the dosage given. The low value probably depended on the impaired function of the obstructed kidney. Our results show the existence of a significant reflux from the renal pelvis of small molecules, which was affected by renal function, intrapelvic pressure and volume.

  14. Absorption of enzymatically active sup 125 I-labeled bovine milk xanthine oxidase fed to rabbits

    SciTech Connect

    Rzucidlo, S.J. ); Zikakis, J.P. )

    1990-05-01

    Rabbits fed a regular laboratory diet supplemented with a high-fat milk containing xanthine oxidase (XO) were studied to determine the presence of active XO in the blood. A pilot feeding study, where rabbits consumed a high-fat diet containing xanthine oxidase, showed a correlation between dairy food consumption and XO activity in the blood. Antibody to dietary XO was also found. In a second study, rabbits were fed ad libitum the high-fat milk and blood serum samples were tested weekly for XO activity. No elevation in serum XO activity was found. A third study showed that serum XO activity was increased when rabbits were force fed the high-fat milk. The final study consisted of force feeding {sup 125}I-labeled XO to one rabbit to ascertain whether the observed increase in serum XO was due to dietary or endogenous XO. Isoelectric focusing of sera collected from the test rabbit strongly suggested that at least a portion of the serum XO contained the radioactive label. This is the first direct evidence showing the uptake of dietary active XO from the gut.

  15. Absence of preferential uptake of ( sup 125 I)iododihydrorhodamine 123 by four human tumor xenografts

    SciTech Connect

    Kinsey, B.M.; Van den Abbeele, A.D.; Adelstein, S.J.; Kassis, A.I. )

    1989-11-01

    The biodistribution of ({sup 125}I)iododihydrorhodamine 123 has been studied over a 96-h period in four human tumor xenograft models: HT-29 colon adenocarcinoma, PC-3 prostate carcinoma, HT-1080 fibrosarcoma, and PaCa-2 pancreatic carcinoma. Elimination of radioactivity in the tumor-bearing nude mice was rapid during the first 24 h and slow thereafter. The lack of uptake in the thyroid indicated there was little, if any, deiodination of the molecule. Activity was found mainly in the liver and spleen. Accumulation of radioactivity was low in all four tumors examined. At 4 h postinjection, as well as at 24 and 48 h, however, the total radioactive content in each of the four tumors was directly proportional to the weight of the tumor sample. This correlation was independent of tumor type, route of injection (i.v./i.p.) or dose (1.2-6 microCi/mouse). This was not true for any of the normal tissues, suggesting that this accumulation may be governed by certain intrinsic characteristics of the cancers tested.

  16. ( sup 125 I)(+)FISCH: A new CNS D-1 dopamine receptor imaging ligand

    SciTech Connect

    Billings, J.; Kung, M.P.; Chumpradit, S.; Pan, S.; Kung, H.F. )

    1989-01-01

    Radiolabeling and in vitro and in vivo evaluation of an iodinated benzazepine: ({sup 125}I)FISCH 7-Chloro-8-hydroxy-1-(4{prime}-iodophenyl)-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine, as a potential imaging agent for CNS D-1 dopamine receptors in animals, were investigated. After an iv injection, this benzazepine derivative showed good brain uptake in rats. The striatum/cerebellum ratio was 2.50 at 60 min after the injection. The regional distribution in rat brain, as measured by ex vivo autoradiography, displayed highest uptake in the regions of the striatal complex and the substantia nigra, regions known to have a high concentration of D-1 dopamine receptors. Furthermore, this localized regional cerebral distribution was blocked by pretreatment with SCH-23390, a selective D-1 dopamine receptor antagonist. The in vitro binding affinity of this agent in rat striatum tissue preparation displayed a Kd of 1.43 {plus minus} 0.15 nM. Competition data (in vitro) showed the following rank order of potency: SCH-23390 > ({plus minus})IBZP >> apomorphine > WB 4101 > ketanserin {approximately} spiperone. The preliminary data suggest that this analog of SCH-23390 shows similar selectivity for the CNS D-1 receptor.

  17. Improved /sup 125/I radioimmunoassay for cotinine by selective removal of bridge antibodies

    SciTech Connect

    Knight, G.J.; Wylie, P.; Holman, M.S.; Haddow, J.E.

    1985-01-01

    We describe an /sup 125/I-based RIA for cotinine, the major metabolite of nicotine. The slope of the dose-response curve was quite shallow (6-8% change in binding per doubling dose), resulting in between-assay CVs of 15 to 20%. This effect occurred because the radioligand formed by linking a cotinine derivative to tyramine manifested greater affinity for the anti-cotinine antibodies than did cotinine itself. We absorbed the serum with a derivative of nicotine coupled to the carrier protein via a chemical bridge similar to that used to form the cotinine/carrier protein immunogen. An RIA in which we used such absorbed serum showed a significantly increased slope of the dose-response curve (11-13% change in binding per doubling dose), and between-assay CVS were only 6 to 8%. We suggest that this improvement results because absorption removes anti-bridge antibodies directed against the chemical-bond common to the cotinine/carrier-protein immunogen and to the cotinine/tyramine radioligand.

  18. Altered (/sup 125/I)epidermal growth factor binding and receptor distribution in psoriasis

    SciTech Connect

    Nanney, L.B.; Stoscheck, C.M.; Magid, M.; King, L.E. Jr.

    1986-03-01

    Stimulation of growth and differentiation of human epidermis by epidermal growth factor (EGF) is mediated by its binding to specific receptors. Whether EGF receptors primarily mediate cell division or differentiation in hyperproliferative disease such as psoriasis vulgaris is unclear. To study the pathogenesis of psoriasis, 4-mm2 punch biopsy specimens of normal, uninvolved, and involved psoriatic skin were assayed for EGF receptors by autoradiographic, immunohistochemical, and biochemical methods. Using autoradiographic and immunohistochemical methods, basal keratinocytes were found to contain the greatest number of EGF binding sites and immunoreactive receptors as compared to the upper layers of the epidermis in both normal epidermis and psoriatic skin. No EGF receptor differences between normal and psoriatic epidermis were observed in this layer. In the upper layers of the epidermis, a 2-fold increase in EGF binding capacity was observed in psoriatic skin as compared with normal thin or thick skin. Biochemical methods indicated that (/sup 125/I)EGF binding was increased in psoriatic epidermis as compared with similar thickness normal epidermis when measured on a protein basis. Epidermal growth factor was shown to increase phosphorylation of the EGF receptor in skin. EGF receptors retained in the nonmitotic stratum spinosum and parakeratotic stratum corneum may reflect the incomplete, abnormal differentiation that occurs in active psoriatic lesions. Alternatively, retained EGF receptors may play a direct role in inhibiting cellular differentiation in the suprabasal layers.

  19. Thermoluminescence dosimetry measurements of brachytherapy sources in liquid water

    SciTech Connect

    Tailor, Ramesh; Tolani, Naresh; Ibbott, Geoffrey S.

    2008-09-15

    Radiation therapy dose measurements are customarily performed in liquid water. The characterization of brachytherapy sources is, however, generally based on measurements made with thermoluminescence dosimeters (TLDs), for which contact with water may lead to erroneous readings. Consequently, most dosimetry parameters reported in the literature have been based on measurements in water-equivalent plastics, such as Solid Water. These previous reports employed a correction factor to transfer the dose measurements from a plastic phantom to liquid water. The correction factor most often was based on Monte Carlo calculations. The process of measuring in a water-equivalent plastic phantom whose exact composition may be different from published specifications, then correcting the results to a water medium leads to increased uncertainty in the results. A system has been designed to enable measurements with TLDs in liquid water. This system, which includes jigs to support water-tight capsules of lithium fluoride in configurations suitable for measuring several dosimetric parameters, was used to determine the correction factor from water-equivalent plastic to water. Measurements of several {sup 125}I and {sup 131}Cs prostate brachytherapy sources in liquid water and in a Solid Water phantom demonstrated a correction factor of 1.039{+-}0.005 at 1 cm distance. These measurements are in good agreement with a published value of this correction factor for an {sup 125}I source.

  20. Development of a high specific activity radioligand, /sup 125/I-LSD, and its application to the study of serotonin receptors

    SciTech Connect

    Kadan, M.J.

    1987-01-01

    /sup 125/I-Labeled receptor ligands can be synthesized with specific activities exceeding 2000 Ci/mmol, making them nearly 70-fold more sensitive in receptor site assays than (mono) tritiated ligands. We have synthesized and characterized /sup 125/I-lysergic acid diethylamide (/sup 125/I-LSD), the first radioiodinated ligand for serotonin receptor studies. The introduction of /sup 125/I at the 2 position of LSD increased both the affinity and selectivity of this compound for serotonin 5-HT/sub 2/ receptors in rat cortex. The high specific activity of /sup 125/I-LSD and its high ratio of specific to nonspecific binding make this ligand especially useful for autoradiographic studies of serotonin receptor distribution. We have found that /sup 125/I-LSD binds with high affinity to a class of serotonin receptors in the CNS of the marine mollusk Aplysia californica.

  1. Binding of an ( sup 125 I) labelled thromboxane A2/prostaglandin H2 receptor agonist to baboon platelets

    SciTech Connect

    Dorn, G.W. II; De Jesus, A. )

    1989-12-01

    To characterize the thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor on baboon platelets the binding of (125I)BOP was studied. (125I)BOP bound to washed baboon platelets in a saturable manner. Scatchard analysis of binding isotherms revealed a Kd of 1.12 +/- 0.08 nM and a binding capacity of 54 +/- 5 fmoles/10(8) platelets (326 sites/platelet). Several TXA2/PGH2 agonists and antagonists displaced (125I)BOP from its baboon platelet binding site with a rank order of potency similar to human platelets: I-BOP greater than SQ29548 greater than U46619 = I-PTA-OH greater than PTA-OH. I-BOP aggregated washed baboon platelets with an EC50 of 10 +/- 4 nM. The results indicate that (125I)BOP binds to the TXA2/PGH2 receptor on baboon platelets and that this receptor is similar to its human counterpart.

  2. Relationship between alveolar bone measured by /sup 125/I absorptiometry with analysis of standardized radiographs: 2. Bjorn technique

    SciTech Connect

    Ortman, L.F.; McHenry, K.; Hausmann, E.

    1982-05-01

    The Bjorn technique is widely used in periodontal studies as a standardized measure of alveolar bone. Recent studies have demonstrated the feasibility of using /sup 125/I absorptiometry to measure bone mass. The purpose of this study was to compare /sup 125/I absorptiometry with the Bjorn technique in detecting small sequential losses of alveolary bone. Four periodontal-like defects of incrementally increasing size were produced in alveolar bone in the posterior segment of the maxilla of a human skull. An attempt was made to sequentially reduce the amount of bone in 10% increments until no bone remained, a through and through defect. The bone remaining at each step was measured using /sup 125/I absorptiometry. At each site the /sup 125/I absorptiometry measurements were made at the same location by fixing the photon source to a prefabricated precision-made occlusal splint. This site was just beneath the crest and midway between the borders of two adjacent teeth. Bone loss was also determined by the Bjorn technique. Standardized intraoral films were taken using a custom-fitted acrylic clutch, and bone measurements were made from the root apex to coronal height of the lamina dura. A comparison of the data indicates that: (1) in early bone loss, less than 30%, the Bjorn technique underestimates the amount of loss, and (2) in advanced bone loss, more than 60% the Bjorn technique overestimates it.

  3. Quantitative pharmacological analysis of 2-125I-iodomelatonin binding sites in discrete areas of the chicken brain

    SciTech Connect

    Siuciak, J.A.; Krause, D.N.; Dubocovich, M.L. )

    1991-09-01

    The authors have localized and characterized 2-125I-iodomelatonin binding sites in the chicken brain using in vitro quantitative autoradiography. Binding sites were widely distributed throughout the chicken brain, predominantly in regions associated with the visual system. The specific binding of 2-125I-iodomelatonin to discrete chicken brain areas was found to be saturable, reversible, and of high affinity. The specific binding of 2-125I-iodomelatonin (75 pm) was quantitated for 40 identifiable brain regions. Eight brain regions were chosen for binding characterization and pharmacological analysis: optic tectum, Edinger-Westphal nucleus, oculomotor nucleus, nucleus rotundus, ventral supraoptic decussation, ventrolateral geniculate nucleus, neostriatum, and ectostriatum. These regions showed no rostral-caudal gradient in 2-125I-iodomelatonin specific binding, and saturation analysis revealed a single class of high-affinity sites with KD values in the range of 33-48 pM and receptor site density (Bmax) ranging from 31 to 58 fmol/mg protein. Competition experiments carried out with various indoles revealed a similar order of pharmacological affinities in these areas: melatonin greater than 6-chloromelatonin greater than methoxyluzindole greater than N-acetylserotonin greater than luzindole much greater than 5-HT greater than 5-methoxytryptamine. The affinity constants determined by quantitative autoradiography for these compounds to compete for 2-125I-iodomelatonin binding in the optic tectum correlated well with the affinities in chicken brain membranes at 25 degrees C (r = 0.966; slope = 0.845; n = 7) and 0 degree C (r = 0.946; slope = 0.379; n = 7), chicken retinal membranes (r = 0.973; slope = 0.759; n = 7), and the potency or affinity of these compounds to affect the calcium-dependent release of 3H-dopamine from the rabbit retina (r = 0.902; slope = 0.506; n = 6).

  4. A Monte Carlo investigation of lung brachytherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Sutherland, J. G. H.; Furutani, K. M.; Thomson, R. M.

    2013-07-01

    Iodine-125 (125I) and Caesium-131 (131Cs) brachytherapy have been used in conjunction with sublobar resection to reduce the local recurrence of stage I non-small cell lung cancer compared with resection alone. Treatment planning for this procedure is typically performed using only a seed activity nomogram or look-up table to determine seed strand spacing for the implanted mesh. Since the post-implant seed geometry is difficult to predict, the nomogram is calculated using the TG-43 formalism for seeds in a planar geometry. In this work, the EGSnrc user-code BrachyDose is used to recalculate nomograms using a variety of tissue models for 125I and 131Cs seeds. Calculated prescription doses are compared to those calculated using TG-43. Additionally, patient CT and contour data are used to generate virtual implants to study the effects that post-implant deformation and patient-specific tissue heterogeneity have on perturbing nomogram-derived dose distributions. Differences of up to 25% in calculated prescription dose are found between TG-43 and Monte Carlo calculations with the TG-43 formalism underestimating prescription doses in general. Differences between the TG-43 formalism and Monte Carlo calculated prescription doses are greater for 125I than for 131Cs seeds. Dose distributions are found to change significantly based on implant deformation and tissues surrounding implants for patient-specific virtual implants. Results suggest that accounting for seed grid deformation and the effects of non-water media, at least approximately, are likely required to reliably predict dose distributions in lung brachytherapy patients.

  5. Tissue composition and density impact on the clinical parameters for (125)I prostate implants dosimetry.

    PubMed

    Oliveira, Susana Maria; Teixeira, Nuno José; Fernandes, Lisete; Teles, Pedro; Vieira, Guy; Vaz, Pedro

    2014-11-01

    The MCNPX code was used to calculate the TG-43U1 recommended parameters in water and prostate tissue in order to quantify the dosimetric impact in 30 patients treated with (125)I prostate implants when replacing the TG-43U1 formalism parameters calculated in water by a prostate-like medium in the planning system (PS) and to evaluate the uncertainties associated with Monte Carlo (MC) calculations. The prostate density was obtained from the CT of 100 patients with prostate cancer. The deviations between our results for water and the TG-43U1 consensus dataset values were -2.6% for prostate V100, -13.0% for V150, and -5.8% for D90; -2.0% for rectum V100, and -5.1% for D0.1; -5.0% for urethra D10, and -5.1% for D30. The same differences between our water and prostate results were all under 0.3%. Uncertainties estimations were up to 2.9% for the gL(r) function, 13.4% for the F(r,θ) function and 7.0% for Λ, mainly due to seed geometry uncertainties. Uncertainties in extracting the TG-43U1 parameters in the MC simulations as well as in the literature comparison are of the same order of magnitude as the differences between dose distributions computed for water and prostate-like medium. The selection of the parameters for the PS should be done carefully, as it may considerably affect the dose distributions. The seeds internal geometry uncertainties are a major limiting factor in the MC parameters deduction. PMID:25239870

  6. Characterization of rat cerebral cortical beta adrenoceptor subtypes using (-)-( sup 125 I)-iodocyanopindolol

    SciTech Connect

    Tiong, A.H.; Richardson, J.S. )

    1990-01-01

    (-)-(125I)-Iodocyanopindolol (-(ICYP)), used to characterize beta adrenoceptors on membrane preparations from rat cerebral cortex, was shown to have affinity for both beta adrenoceptors and serotonin receptors. Therefore, 10 microM serotonin was added to the assays to prevent (-)ICYP binding to serotonin receptors. Under these conditions, (-)ICYP binding to the cortical membrane preparation was reversible and saturable, and the association reaction was very slow. The dissociation reaction was also very slow, and revealed two affinity states corresponding to a high and a low affinity state. Scatchard analysis showed a single class of binding sites with an equilibrium dissociation constant (KD) of 20.7 pM, and a maximal density of binding sites (Bmax) of 95.1 fmol/mg membrane protein. Displacement binding analyses revealed a potency series of (-) isoproterenol greater than (-) epinephrine equal to (-) norepinephrine, suggesting a predominance of the beta 1 adrenoceptor subtype. Detailed competition ligand binding studies with the selective beta 1 adrenoceptor antagonist ICI-89406 and the selective beta 2 adrenoceptor antagonist ICI-118551, showed that about 70% of the beta adrenoceptor population in the rat cortex is of the beta 1 subtype with the remainder being of the beta 2 subtype. We conclude that since (-)ICYP binds to both beta adrenoceptors and serotonin receptors, it is important to prevent the binding of (-)ICYP to serotonin receptors by adding a suppressing ligand like excess cold serotonin when assaying beta adrenoceptors. We have presented the first such characterization of rat cerebral cortical beta adrenoceptors with (-)ICYP in this study.

  7. Exposure to environmental tobacco smoke measured by cotinine sup 125 I-radioimmunoassay

    SciTech Connect

    Knight, G.J.; Palomaki, G.E.; Lea, D.H.; Haddow, J.E. )

    1989-06-01

    We describe a polyclonal-antiserum-based {sup 125}I-radioimmunoassay for cotinine that is suitable for measuring nonsmokers' passive exposure to tobacco smoke in the environment. The standard curve ranged from 0.25 to 12.0 micrograms/L, with an estimated lower limit of sensitivity of 0.2 microgram/L (95% B/Bo = 0.2 microgram/L; 50% B/Bo = 4.0 micrograms/L). The median within-assay CVs for patients' samples with cotinine values from 0.4 to 1.3, 1.4 to 2.4, 2.5 to 4.6, and 4.7 to 15.6 micrograms/L were 13.9%, 7.2%, 5.1%, and 5.7%, respectively. Between-assay CVs for two quality-control sera with average values of 1.53 and 3.68 micrograms/L were 14.3% and 7.8%, respectively. Analytical recoveries of cotinine from smokers' sera diluted in zero calibrant ranged from 91% to 116%. Cotinine values determined on 79 paired sera and urines from nonsmokers showed significant correlation with self-reported exposure to environmental tobacco smoke (r = 0.49, P less than 0.001 for sera; r = 0.57, P less than 0.001 for urine). The log of the values for serum and urine cotinine were also significantly correlated (r = 0.85, P less than 0.001). Evidently, polyclonal antiserum can be used to develop a cotinine assay for measuring exposure to environmental tobacco smoke that compares well with that described for monoclonal-based assays.

  8. Interstitial radiotherapy for early stage vaginal cancer. A new method of tumor localization.

    PubMed

    Finan, M A; Hoffman, M S; Greenberg, H; Roberts, W S; Cavanagh, D; Fiorica, J V

    1993-03-01

    Carcinoma of the vagina is optimally treated primarily with teletherapy, followed by interstitial needle brachytherapy. Following teletherapy, identification of the original tumor site is frequently difficult. We describe a method of marking the tumor with an india ink "tattoo" at initial presentation, followed by placement of a purse-string suture and titanium hemoclips at the time of brachytherapy. A stable marker is created so that the location of the original vaginal tumor can be easily identified on dosimetric films. PMID:7683723

  9. Interstitial cystitis - resources

    MedlinePlus

    Resources - interstitial cystitis ... The following organizations are good resources for information on interstitial cystitis : Interstitial Cystitis Association -- www.ichelp.org National Kidney and Urologic Diseases Information Clearinghouse -- www.kidney.niddk. ...

  10. Childhood Interstitial Lung Disease

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Childhood Interstitial Lung Disease? Childhood interstitial (in-ter-STISH-al) lung disease, ... with similar symptoms—it's not a precise diagnosis. Interstitial lung disease (ILD) also occurs in adults. However, the cause ...

  11. Brachytherapy seed and applicator localization via iterative forward projection matching algorithm using digital X-ray projections

    NASA Astrophysics Data System (ADS)

    Pokhrel, Damodar

    Interstitial and intracavitary brachytherapy plays an essential role in management of several malignancies. However, the achievable accuracy of brachytherapy treatment for prostate and cervical cancer is limited due to the lack of intraoperative planning and adaptive replanning. A major problem in implementing TRUS-based intraoperative planning is an inability of TRUS to accurately localize individual seed poses (positions and orientations) relative to the prostate volume during or after the implantation. For the locally advanced cervical cancer patient, manual drawing of the source positions on orthogonal films can not localize the full 3D intracavitary brachytherapy (ICB) applicator geometry. A new iterative forward projection matching (IFPM) algorithm can explicitly localize each individual seed/applicator by iteratively matching computed projections of the post-implant patient with the measured projections. This thesis describes adaptation and implementation of a novel IFPM algorithm that addresses hitherto unsolved problems in localization of brachytherapy seeds and applicators. The prototype implementation of 3-parameter point-seed IFPM algorithm was experimentally validated using a set of a few cone-beam CT (CBCT) projections of both the phantom and post-implant patient's datasets. Geometric uncertainty due to gantry angle inaccuracy was incorporated. After this, IFPM algorithm was extended to 5-parameter elongated line-seed model which automatically reconstructs individual seed orientation as well as position. The accuracy of this algorithm was tested using both the synthetic-measured projections of clinically-realistic Model-6711 125I seed arrangements and measured projections of an in-house precision-machined prostate implant phantom that allows the orientations and locations of up to 100 seeds to be set to known values. The seed reconstruction error for simulation was less than 0.6 mm/3o. For the physical phantom experiments, IFPM absolute accuracy for

  12. [125I]AT-1012, a New High Affinity Radioligand for the α3β4 Nicotinic Acetylcholine Receptors

    PubMed Central

    Wu, Jinhua; Perry, David C.; Bupp, James E.; Jiang, Faming; Polgar, Willma E.; Toll, Lawrence; Zaveri, Nurulain T.

    2013-01-01

    Recent genetic and pharmacological studies have implicated the α3, β4 and a5 subunits of the nicotinic acetylcholine receptor (nAChR) in dependence to nicotine and other abused drugs and nicotine withdrawal. The α3β4* nAChR subtype has been shown to co-assemble with the α5 or β3 nAChR subunits, and is found mainly in the autonomic ganglia and select brain regions. It has been difficult to study the α3β4 nAChR because there have been no selective nonpeptidic ligands available to independently examine its pharmacology. We recently reported the synthesis of a [125I]-radiolabeled analog of a high affinity, selective small-molecule α3β4 nAChR ligand, AT-1012. We report here the vitro characterization of this radioligand in receptor binding and in vitro autoradiographic studies targeting the α3β4* nAChR. Binding of [125I]AT-1012 was characterized at the rat α3β4- and α4β2 nAChR transfected into HEK cells as well as at the human α3β4α5 nAChR in HEK cells. Binding affinity of [125I]AT-1012 at the rat α3β4 nAChR was 1.4 nM, with a Bmax of 10.3 pmol/mg protein, similar to what was determined using [3H]epibatidine. Saturation isotherms suggested that [125I]AT-1012 binds to a single site on the α3β4 nAChR. Similar high binding affinity was also observed for [125I]AT-1012 at human α3β4α5 nAChR in a human α3β4aα nAChR transfected cell line. [125I]AT-1012 did not bind with high affinity to membranes from α4β2 nAChR-transfected HEK cells, and [3H]epibatidine binding studies showed that AT-1012 had over 100-fold binding selectivity for the α3β4 over α4β2 nAChR. Ki values determined for known nAChR compounds using [125I]AT-1012 as radioligand were comparable to those obtained with [3H]epibatidine. [125I]AT-1012 was also used to label the α3β4 nAChR in rat brain slices in vitro using autoradiography which showed highly localized binding of the radioligand in brain regions consistent with the discreet localization of the α3β4 nAChR. We

  13. Metabolism of /sup 125/I-atrial natriuretic factor by vascular smooth muscle cells. Evidence for a peptidase that specifically removes the COOH-terminal tripeptide

    SciTech Connect

    Johnson, G.R.; Arik, L.; Foster, C.J.

    1989-07-15

    The addition of 200 pM monoiodinated human atrial natriuretic factor-(99-126) (125I-hANF) to cultured bovine aortic smooth muscle cells at 37/degree/C resulted in a rapid clearance from the medium (t1/2 approximately 7.5 min). Within 5 min, (125I)iodotyrosine126 (125I-Y), Arg125-(125I)iodotyrosine126 (125I-RY) and Phe124-Arg-(125)iodotyrosine126 (125I-FRY) appeared in the medium. The identities of these degradation products were confirmed by (1) retention time on high performance liquid chromatography (HPLC) relative to standards, (2) products generated by digestion with aminopeptidase M, and (3) the absence of the Met110. Preincubation of the cells with ammonium chloride or chloroquine resulted in a significant increase in the intracellular accumulation of radiolabel, indicative of endocytosis and rapid delivery of 125I-hANF to an acidic intracellular compartment (endosome and/or lysosome). Neither ammonium chloride, chloroquine, nor excess unlabeled hANF blocked the rapid appearance in the medium of 125I-RY or 125I-FRY. Bestatin inhibited the generation of 125I-RY, with a concomitant increase in 125I-FRY, suggesting that the 125I-RY is produced by aminopeptidase action on 125I-FRY. The endopeptidase 24.11 (enkephalinase) inhibitor, SCH 39370, did not inhibit the formation of 125I-FRY. These results provide evidence of a peptidase capable of specifically removing the COOH-terminal tripeptide from 125I-hANF. The COOH-terminal tripeptide, Phe124-Arg-Tyr126, was also isolated from cell digests of hANF by HPLC and its identity confirmed by amino acid analysis. Since it is generally believed that the COOH-terminal tripeptide is critical to many of atrial natriuretic factor-(99-126)'s bioactivities, this enzyme may be involved in the inactivation of atrial natriuretic factor-(99-126) in target tissues.

  14. Gadolinium-153 as a brachytherapy isotope

    NASA Astrophysics Data System (ADS)

    Enger, Shirin A.; Fisher, Darrell R.; Flynn, Ryan T.

    2013-02-01

    The purpose of this work was to present the fundamental dosimetric characteristics of a hypothetical 153Gd brachytherapy source using the AAPM TG-43U1 dose-calculation formalism. Gadolinium-153 is an intermediate-energy isotope that emits 40-100 keV photons with a half-life of 242 days. The rationale for considering 153Gd as a brachytherapy source is for its potential of patient specific shielding and to enable reduced personnel shielding requirements relative to 192Ir, and as an isotope for interstitial rotating shield brachytherapy (I-RSBT). A hypothetical 153Gd brachytherapy source with an active core of 0.84 mm diameter, 10 mm length and specific activity of 5.55 TBq of 153Gd per gram of Gd was simulated with Geant4. The encapsulation material was stainless steel with a thickness of 0.08 mm. The radial dose function, anisotropy function and photon spectrum in water were calculated for the 153Gd source. The simulated 153Gd source had an activity of 242 GBq and a dose rate in water 1 cm off axis of 13.12 Gy h-1, indicating that it would be suitable as a low-dose-rate or pulsed-dose-rate brachytherapy source. The beta particles emitted have low enough energies to be absorbed in the source encapsulation. Gadolinium-153 has an increasing radial dose function due to multiple scatter of low-energy photons. Scattered photon dose takes over with distance from the source and contributes to the majority of the absorbed dose. The anisotropy function of the 153Gd source decreases at low polar angles, as a result of the long active core. The source is less anisotropic at polar angles away from the longitudinal axes. The anisotropy function increases with increasing distance. The 153Gd source considered would be suitable as an intermediate-energy low-dose-rate or pulsed-dose-rate brachytherapy source. The source could provide a means for I-RSBT delivery and enable brachytherapy treatments with patient specific shielding and reduced personnel shielding requirements relative to

  15. Gadolinium-153 as a brachytherapy isotope.

    PubMed

    Enger, Shirin A; Fisher, Darrell R; Flynn, Ryan T

    2013-02-21

    The purpose of this work was to present the fundamental dosimetric characteristics of a hypothetical (153)Gd brachytherapy source using the AAPM TG-43U1 dose-calculation formalism. Gadolinium-153 is an intermediate-energy isotope that emits 40-100 keV photons with a half-life of 242 days. The rationale for considering (153)Gd as a brachytherapy source is for its potential of patient specific shielding and to enable reduced personnel shielding requirements relative to (192)Ir, and as an isotope for interstitial rotating shield brachytherapy (I-RSBT). A hypothetical (153)Gd brachytherapy source with an active core of 0.84 mm diameter, 10 mm length and specific activity of 5.55 TBq of (153)Gd per gram of Gd was simulated with Geant4. The encapsulation material was stainless steel with a thickness of 0.08 mm. The radial dose function, anisotropy function and photon spectrum in water were calculated for the (153)Gd source. The simulated (153)Gd source had an activity of 242 GBq and a dose rate in water 1 cm off axis of 13.12 Gy h(-1), indicating that it would be suitable as a low-dose-rate or pulsed-dose-rate brachytherapy source. The beta particles emitted have low enough energies to be absorbed in the source encapsulation. Gadolinium-153 has an increasing radial dose function due to multiple scatter of low-energy photons. Scattered photon dose takes over with distance from the source and contributes to the majority of the absorbed dose. The anisotropy function of the (153)Gd source decreases at low polar angles, as a result of the long active core. The source is less anisotropic at polar angles away from the longitudinal axes. The anisotropy function increases with increasing distance. The (153)Gd source considered would be suitable as an intermediate-energy low-dose-rate or pulsed-dose-rate brachytherapy source. The source could provide a means for I-RSBT delivery and enable brachytherapy treatments with patient specific shielding and reduced personnel

  16. (/sup 125/I)endothelin-1 binding sites: Autoradiographic studies in the brain and periphery of various species including humans

    SciTech Connect

    Hoyer, D.; Waeber, C.; Palacios, J.M.

    1989-01-01

    Quantitative autoradiography with (/sup 125/I)-endothelin-1 (ET-1) has been used to localize putative ET-1 recognition sites in the brain and peripheral organs of various species including humans. High densities of high-affinity (/sup 125/I)ET-1 binding sites were observed in heart, lung, liver, kidney, blood vessels, and brain. A differential pattern of distribution of ET-1 recognition sites was observed in the periphery and in the brain, indicating that putative ET-1 receptors are not located only in blood vessels. The data are consistent with a role for ET-1 in vascular smooth muscle and nonvascular tissues, such as heart, lung, intestine, kidney, and brain.

  17. Dopaminergic control of 125I-labeled neurotensin binding site density in corticolimbic structures of the rat brain.

    PubMed Central

    Herve, D; Tassin, J P; Studler, J M; Dana, C; Kitabgi, P; Vincent, J P; Glowinski, J; Rostene, W

    1986-01-01

    In the rat brain, destruction of dopaminergic cell groups by injections of 6-hydroxydopamine into the ventral mesencephalic tegmentum results in large decreases in the number of neurotensin binding sites in the mesencephalon and the striatum. In contrast, these lesions produce an increase in the number of 125I-labeled neurotensin binding sites in the lateral part of the prefrontal cortex despite a large decrease in cortical dopamine levels. Increases in the number of 125I-labeled neurotensin binding sites in this cortical area as well as in the entorhinal cortex, the nucleus accumbens, and the central part of the striatum were also obtained after chronic blockade of dopamine neurotransmission by a long-acting neuroleptic pipotiazine palmitic ester. We propose that dopamine inputs regulate the density of postsynaptic neurotensin binding sites through cortical and subcortical dopamine receptors. Therefore, some of the clinical effects of neuroleptics in schizophrenic patients could be partly related to changes in neurotensin neurotransmission. Images PMID:3016745

  18. Synthesis and biological evaluation of [125I]- and [123I]-4-iododexetimide, a potent muscarinic cholinergic receptor antagonist.

    PubMed

    Wilson, A A; Dannals, R F; Ravert, H T; Frost, J J; Wagner, H N

    1989-05-01

    A series of halogenated racemic analogues of dexetimide (1) was synthesized and their affinity for the muscarinic cholinergic receptor measured. One analogue, 4-iododexetimide (21), was efficiently labeled with 125I and 123I at high specific activity. In vitro binding studies and in vivo biodistribution studies suggest that 123I-labeled 21 may be useful for imaging muscarinic cholinergic receptors in the living human brain with single photon emission computed tomography. PMID:2785211

  19. /sup 125/I-labeled crosslinking reagent that is hydrophilic, photoactivatable, and cleavable through an azo linkage

    SciTech Connect

    Denny, J.B.; Blobel, G.

    1984-09-01

    A radioactive crosslinking reagent, N-(4-(p-azido-m-(/sup 125/I)iodophenylazo)benzoyl)-3-aminopropyl-N'-oxysulfosuccinimide ester, has been synthesized. The reagent is photoactivatable, water-soluble, cleavable through an azo linkage, and labeled with /sup 125/I at the carrier-free specific activity of 2000 Ci/mmol. Any protein derivatized with the reagent is thus converted into an /sup 125/I-labeled photoaffinity probe. Crosslinks are formed following photolysis with 366-nm light, and cleavage by sodium dithionite results in the donation of radioactivity to the distal partner in crosslinked complexes. The newly labeled proteins are then analyzed by gel electrophoresis and autoradiography. The compound was prepared by iodination of N-(4-(p-aminophenylazo)benzoyl)-3-aminopropionic acid using carrier-free Na/sup 125/I and chloramine-T, followed by azide formation and conversion to the water-soluble sulfosuccinimide ester. As a model system, protein A-Sepharose was derivatized with the reagent under subdued light. Each derivatized protein A molecule contained only one crosslinker. The derivatized protein A-Sepharose was then photolyzed in the presence of human serum and subsequently treated with sodium dithionite. Analysis of the serum by gel electrophoresis revealed that 1.1% of the radioactive label originally present on the protein A-Sepharose was transferred to the heavy chain of IgG, which was the most intensely labeled protein in the gel. The next most intensely labeled protein was IgG light chain, which incorporated radioactivity that was lower by a factor of 3.6 than that of the heavy chain. 36 references, 3 figures.

  20. /sup 125/I)-(d(CH2)5, Sar7)AVP: a selective radioligand for V1 vasopressin receptors

    SciTech Connect

    Kelly, J.M.; Abrahams, J.M.; Phillips, P.A.; Mendelsohn, F.A.; Grzonka, Z.; Johnston, C.I.

    1989-01-01

    Arginine8-vasopressin (AVP) acts on vascular and hepatic V1 receptors to influence blood pressure and glycogenolysis respectively. We have radioiodinated the AVP V1 receptor antagonist, (1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic-acid), 7-sarcosine, 8-arginine) vasopressin ((d(CH2)5, Sar7)AVP) and determined its receptor-binding properties in rat liver and kidney plasma membranes. The binding was of high affinity to single classes of receptors (liver: Kd = 3.0 nM and Bmax = 530 +/- 10 fmol/mg protein, kidney: Kd = 0.5 +/- 0.9 nM and Bmax = 11 +/- 8 fmol/mg protein). Competition of (125I)-(d(CH2)5, Sar7)AVP binding by unlabelled AVP analogues gave the following order of potency in both tissues, consistent with that expected for binding to a V1 receptor: (d(CH2)5, Tyr(Me)2)AVP greater than AVP greater than (d(CH2)5, D-Ile2, Ile4) AVP greater than DDAVP. No degradation of (125I)-(d(CH2)5, Sar7)AVP during incubation or storage was detected by HPLC analysis. We have used (125I)-(d(CH2)5, Sar7)AVP and in vitro autoradiography to demonstrate its use in localizing brain AVP receptors. These studies suggest that (125I)-(d(CH2)5, Sar7)AVP is a suitable selective radioligand for labelling V1 receptors and will provide a valuable tool for the study of the localization and regulation of AVP V1 receptors in tissues and in receptor isolation.

  1. Characterization of beta-adrenergic receptors in dispersed rat testicular interstitial cells

    SciTech Connect

    Poyet, P.; Labrie, F.

    1987-01-01

    Recent studies have shown that beta-adrenergic agents stimulate steroidogenesis and cyclic AMP formation in mouse Leydig cells in culture. To obtain information about the possible presence and the characteristics of a beta-adrenergic receptor in rat testicular interstitial cells, the potent beta-adrenergic antagonist (/sup 125/I)cyanopindolol (CYP) was used as ligand. Interstitial cells prepared by collagenase dispersion from rat testis were incubated with the ligand for 2 h at room temperature. (/sup 125/I)cyanopindolol binds to a single class of high affinity sites at an apparent KD value of 15 pM. A number of sites of 6,600 sites/cell is measured when 0.1 microM (-) propranolol is used to determine non-specific binding. The order of potency of a series of agonists competing for (/sup 125/I)cyanopindolol binding is consistent with the interaction of a beta 2-subtype receptor: zinterol greater than (-) isoproterenol greater than (-) epinephrine = salbutamol much greater than (-) norepinephrine. In addition, it was observed that the potency of a large series of specific beta 1 and beta 2 synthetic compounds for displacing (/sup 125/I)cyanopindolol in rat interstitial cells is similar to the potency observed for these compounds in a typical beta 2-adrenergic tissue, the rat lung. For example, the potency of zinterol, a specific beta 2-adrenergic agonist, is 10 times higher in interstitial cells and lung than in rat heart, a typical beta 1-adrenergic tissue. Inversely, practolol, a typical beta 1-antagonist, is about 50 times more potent in rat heart than in interstitial cells and lung.

  2. Analysis of postoperative PSA changes after ultrasound-guided permanent [125I] seed implantation for the treatment of prostate cancer.

    PubMed

    Bian, X L; Wang, C Z; Wang, Y; Li, Y N; Zhang, L Z; Liu, L

    2015-01-01

    The aim of this study was to explore postoperative changes in prostate-specific antigen (PSA) levels and risk factors that influence the clinical effects of ultrasound-guided permanent [(125)I] seed implantation in the treatment of prostate cancer. From July 2009 to December 2012, 41 prostate cancer patients who underwent transrectal ultrasound-guided [(125)I] seed implantation were followed up for 3-56 months. The patients were divided into 2 groups according to their results: group A, benign rebound group, 31 cases; and group B, biochemical relapse group, 10 cases. A blood analysis of group A showed that the initial PSA rise after a nadir occurred postoperatively at 16.8 ± 1.2 months, and in 65.8% (27/41) patients the rise occurred during 15-27 weeks. For group B, the initial PSA rise after a nadir occurred postoperatively at 30.2 ± 2.1 months, and the difference in the time parameter of the initial PSA rise after the nadir was statistically significant between the 2 groups (P < 0.01). During treatment, age was shown to be a risk factor for group A (P = 0.0027, P < 0.01). Postoperative changes in PSA levels after ultrasound-guided permanent [(125)I] seed implantation contributed to the assessment of the clinical treatment effects. PMID:26125925

  3. Evaluation of new iodinated acridine derivatives for targeted radionuclide therapy of melanoma using 125I, an Auger electron emitter.

    PubMed

    Gardette, Maryline; Papon, Janine; Bonnet, Mathilde; Desbois, Nicolas; Labarre, Pierre; Wu, Ting-Dee; Miot-Noirault, Elisabeth; Madelmont, Jean-Claude; Guerquin-Kern, Jean-Luc; Chezal, Jean-Michel; Moins, Nicole

    2011-12-01

    The increasing incidence of melanoma and the lack of effective therapy on the disseminated form have led to an urgent need for new specific therapies. Several iodobenzamides or analogs are known to possess specific affinity for melanoma tissue. New heteroaromatic derivatives have been designed with a cytotoxic moiety and termed DNA intercalating agents. These compounds could be applied in targeted radionuclide therapy using (125)I, which emits Auger electrons and gives high-energy, localized irradiation. Two iodinated acridine derivatives have been reported to present an in vivo kinetic profile conducive to application in targeted radionuclide therapy. The aim of the present study was to perform a preclinical evaluation of these compounds. The DNA intercalating property was confirmed for both compounds. After radiolabeling with (125)I, the two compounds induced in vitro a significant radiotoxicity to B16F0 melanoma cells. Nevertheless, the acridine compound appeared more radiotoxic than the acridone compound. While cellular uptake was similar for both compounds, SIMS analysis and in vitro protocol showed a stronger affinity for melanin with acridone derivative, which was able to induce a predominant scavenging process in the melanosome and restrict access to the nucleus. In conclusion, the acridine derivative with a higher nuclear localization appeared a better candidate for application in targeted radionuclide therapy using (125)I. PMID:20567996

  4. Behaviour of 125I-fibrinogen and 131I-albumin in experimental galactosamine-induced hepatitis.

    PubMed Central

    Mahn, I; Merkel, H; Sattler, E L; Müller-Berghaus, G

    1977-01-01

    The turnover of 125I-labelled fibrinogen and 131I-labelled albumin was studied in the course of galactosamine-induced hepatitis in rabbits. In addition to galactosamine, some animals were treated with epsilon-aminocaproic acid (EACA) to inhibit the activation of the fibrinolytic system. The infusion of galactosamine and EACA caused generation of fibrin-rich microclots in the renal glomerular capillaries in seven out of 12 rabbits. Correspondingly, the incorporation of 125I-radioactivity into liver, spleen, and kidneys was pronounced in galactosamine- and EACA-treated rabbits compared with control animals treated with EACA. An acceleration of the 125I-fibrinogen elimination from the plasma was observed between eight and 12 hours after the start of the galactosamine infusion. The administration of heparin in addition to galactosamine and EACA prevented the occurrence of intravascular coagulation, but shortened the survival times of the animals because of bleeding into visceral organs. The elimination of 131I-albumin in plasma as well as the distribution of 131I-radioactivity in organs were similar in all the rabbits independent of the treatment with galactosamine, EACA, or heparin. The experiments indicate that, in addition to diminished synthesis of coagulation factors, disseminated intravascular coagulation is involved in galactosamine-induced hepatitis and contributes to the haemostatic disorder. PMID:873336

  5. Binding of ( sup 125 I)iodipine to parathyroid cell membranes: Evidence of a dihydropyridine-sensitive calcium channel

    SciTech Connect

    Jones, J.I.; Fitzpatrick, L.A. )

    1990-04-01

    The parathyroid cell is unusual, in that an increase in extracellular calcium concentrations inhibits PTH release. Calcium channels are glycoproteins that span cell membranes and allow entry of extracellular calcium into cells. We have demonstrated that the calcium channel agonist (+)202-791, which opens calcium channels, inhibits PTH release and that the antagonist (-)202-791, which closes calcium channels, stimulates PTH release. To identify the calcium channels responsible for these effects, we used a radioligand that specifically binds to calcium channels. Bovine parathyroid cell membranes were prepared and incubated under reduced lighting with (125I) iodipine (SA, 2000 Ci/mmol), which recognizes 1,4-dihydropyridine-sensitive calcium channels. Bound ligand was separated from free ligand by rapid filtration through Whatman GF/B filters. Nonspecific binding was measured by the inclusion of nifedipine at 10 microM. Specific binding represented approximately 40% of the total binding. The optimal temperature for (125I) iodipine binding was 4 C, and binding reached equilibrium by 30 min. The equilibrium dissociation constant (Kd) was approximately 550 pM, and the maximum number of binding sites was 780 fmol/mg protein. Both the calcium channel agonist (+)202-791 and antagonist (-)202-791 competitively inhibited (125I) iodipine binding, with 50% inhibition concentrations of 20 and 300 nM, respectively. These data indicate the presence of dihydropyridine-sensitive calcium channels on parathyroid cell membranes.

  6. Comparative sensitivity of 125I-protein A and enzyme-conjugated antibodies for detection of immunoblotted proteins.

    PubMed Central

    Bernstein, J M; Stokes, C E; Fernie, B

    1987-01-01

    Immunoblotting is a powerful technique for the detection of small amounts of immunologically interesting proteins in unpurified preparations. Iodinated protein A (PA) has been widely used as a second antibody for detection of proteins; however, it does not bind equally well to immunoglobulins from different species nor does it bind to all subclasses of immunoglobulin G (IgG). We compared the sensitivity of [125I]PA with those of both horseradish peroxidase-conjugated second antibodies (HRP) and glucose oxidase-anti-glucose oxidase (GAG) soluble complexes for visualizing bovine serum albumin, human IgG, or human C3 which was either dot blotted or electroblotted to nitrocellulose. [125I]PA was uniformly 10- to 100-fold less sensitive than either HRP or GAG. GAG was more sensitive than HRP except for C3 (electroblotting) and bovine serum albumin and IgG (dot blotting), in which they were equivalent. In general, dot blotting was 10- to 1,000-fold more sensitive than electroblotting. Although relative sensitivities varied depending on the proteins analyzed and the antisera used, GAG appeared to be superior to [125I]PA and HRP for detection of immunoblotted proteins. Images PMID:3540001

  7. Binding, internalization, and retrograde transport of /sup 125/I-nerve growth factor in cultured rat sympathetic neurons

    SciTech Connect

    Claude, P.; Hawrot, E.; Dunis, D.A.; Campenot, R.B.

    1982-01-01

    Sympathetic neurons internalize nerve growth factor (NGF) and transport it retrogradely to their cell bodies where it appears to serve a trophic function in maintaining neuronal survival. We have characterized the binding, internalization, and retrograde transport of /sup 125/I-NGF by cultured rat sympathetic neurons. After 3 to 4 weeks in culture, sympathetic neurons possessed approximately 2 X 10(7) specific, cell surface NGF binding sites per neuron with an apparent affinity constant of 2 to 5 X 10(9) M. The density of binding sites on the plasma membrane of the neurites approximately twice that on the plasma membrane of the cell bodies. Because of the extensive network of neuronal processes, the neurites probably account for more than 99.5% of the total binding in mature cultures. Using electron microscope autoradiography, we localized the distribution of /sup 125/I-NGF in the cell body following a 1-hr exposure to /sup 125/I-NGF. The majority of silver grains were associated with lysosomal organelles, including secondary lysosomes, residual bodies, and multivesicular bodies (MVB). The MVB were the most heavily labeled, with a labeling density (L.D.) of 21, while the lysosomes had a L.D. of 3.1. To study the retrograde transport of /sup 125/I-NGF, neurons were grown in compartmentalized culture dishes and their distal processes were exposed to /sup 125/I-NGF. Radioactive material was transported to the cell bodies at the rate of approximately 3 mm/hr. The transport mechanism was sensitive to colchicine and was saturable with respect to NGF. After 8 hr of transport, when the radioactivity in the cell bodies had reached a steady state, the label again was localized primarily to the MVB (L.D. . 16.8) and the lysosomes (L.D. . 3.8). The nuclei were not labeled significantly and had an overall L.D. of 0.47. We saw no evidence for the accumulation of NGF by the nuclear membrane, the nucleolus, or chromatin.

  8. Monte Carlo calculated doses to treatment volumes and organs at risk for permanent implant lung brachytherapy

    NASA Astrophysics Data System (ADS)

    Sutherland, J. G. H.; Furutani, K. M.; Thomson, R. M.

    2013-10-01

    Iodine-125 (125I) and Caesium-131 (131Cs) brachytherapy have been used with sublobar resection to treat stage I non-small cell lung cancer and other radionuclides, 169Yb and 103Pd, are considered for these treatments. This work investigates the dosimetry of permanent implant lung brachytherapy for a range of source energies and various implant sites in the lung. Monte Carlo calculated doses are calculated in a patient CT-derived computational phantom using the EGsnrc user-code BrachyDose. Calculations are performed for 103Pd, 125I, 131Cs seeds and 50 and 100 keV point sources for 17 implant positions. Doses to treatment volumes, ipsilateral lung, aorta, and heart are determined and compared to those determined using the TG-43 approach. Considerable variation with source energy and differences between model-based and TG-43 doses are found for both treatment volumes and organs. Doses to the heart and aorta generally increase with increasing source energy. TG-43 underestimates the dose to the heart and aorta for all implants except those nearest to these organs where the dose is overestimated. Results suggest that model-based dose calculations are crucial for selecting prescription doses, comparing clinical endpoints, and studying radiobiological effects for permanent implant lung brachytherapy.

  9. Assaying multiple 125I seeds with the well-ionization chamber SourceCheck4π 33005 and a new insert

    PubMed Central

    Ballester, Facundo; Perez-Calatayud, Jose; Vijande, Javier

    2015-01-01

    Purpose To provide a practical solution that can be adopted in clinical routine to fulfill the AAPM-ESTRO recommendations regarding quality assurance of seeds used in prostate permanent brachytherapy. The aim is to design a new insert for the well-ionization chamber SourceCheck4π 33005 (PTW, Germany) that allows evaluating the mean air-kerma strength of up to ten 125I seeds with one single measurement instead of measuring each seed individually. Material and methods The material required is: a) the SourceCheck4π 33005 well-ionization chamber provided with a PTW insert to measure the air-kerma strength S K of one single seed at a time; b) a newly designed insert that accommodates ten seeds in one column, which allows measuring the mean S K of the ten seeds in one single measurement; and c) a container with ten seeds from the same batch and class of the seeds used for the patient implant, and a set of nine non-radioactive seeds. The new insert is characterized by determining its calibration coefficient, used to convert the reading of the well-chamber when ten seeds are measured to their mean S K. The proposed method is validated by comparing the mean S K of the ten seeds obtained from the new insert with the individual measurement of S K of each seed, evaluated with the PTW insert. Results The ratio between the calibration coefficient of the new insert and the calibration coefficient of the PTW insert for the SourceCheck4π 33005 is 1.135 ± 0.007 (k = 1). The mean S K of a set of ten seeds evaluated with this new system is in agreement with the mean value obtained from measuring independently the S K of each seed. Conclusions The new insert and procedure allow evaluating the mean S K of ten seeds prior to the implant in a single measurement. The method is faster and more efficient from radiation protection point of view than measuring the individual S K of each seed. PMID:26816507

  10. Rotating-shield brachytherapy for cervical cancer

    NASA Astrophysics Data System (ADS)

    Yang, Wenjun; Kim, Yusung; Wu, Xiaodong; Song, Qi; Liu, Yunlong; Bhatia, Sudershan K.; Sun, Wenqing; Flynn, Ryan T.

    2013-06-01

    In this treatment planning study, the potential benefits of a rotating shield brachytherapy (RSBT) technique based on a partially-shielded electronic brachytherapy source were assessed for treating cervical cancer. Conventional intracavitary brachytherapy (ICBT), intracavitary plus supplementary interstitial (IS+ICBT), and RSBT treatment plans for azimuthal emission angles of 180° (RSBT-180) and 45° (RSBT-45) were generated for five patients. For each patient, high-risk clinical target volume (HR-CTV) equivalent dose in 2 Gy fractions (EQD2) (α/β = 10 Gy) was escalated until bladder, rectum, or sigmoid colon tolerance EQD2 values were reached. External beam radiotherapy dose (1.8 Gy × 25) was accounted for, and brachytherapy was assumed to have been delivered in 5 fractions. IS+ICBT provided a greater HR-CTV D90 (minimum EQD2 to the hottest 90%) than ICBT. D90 was greater for RSBT-45 than IS+ICBT for all five patients, and greater for RSBT-180 than IS+ICBT for two patients. When the RSBT-45/180 plan with the lowest HR-CTV D90 that was greater than the D90 the ICBT or IS+ICBT plan was selected, the average (range) of D90 increases for RSBT over ICBT and IS+ICBT were 16.2 (6.3-27.2)and 8.5 (0.03-20.16) Gy, respectively. The average (range) treatment time increase per fraction of RSBT was 34.56 (3.68-70.41) min over ICBT and 34.59 (3.57-70.13) min over IS+ICBT. RSBT can increase D90 over ICBT and IS+ICBT without compromising organ-at-risk sparing. The D90 and treatment time improvements from RSBT depend on the patient and shield emission angle.

  11. Design and optimization of a brachytherapy robot

    NASA Astrophysics Data System (ADS)

    Meltsner, Michael A.

    Trans-rectal ultrasound guided (TRUS) low dose rate (LDR) interstitial brachytherapy has become a popular procedure for the treatment of prostate cancer, the most common type of non-skin cancer among men. The current TRUS technique of LDR implantation may result in less than ideal coverage of the tumor with increased risk of negative response such as rectal toxicity and urinary retention. This technique is limited by the skill of the physician performing the implant, the accuracy of needle localization, and the inherent weaknesses of the procedure itself. The treatment may require 100 or more sources and 25 needles, compounding the inaccuracy of the needle localization procedure. A robot designed for prostate brachytherapy may increase the accuracy of needle placement while minimizing the effect of physician technique in the TRUS procedure. Furthermore, a robot may improve associated toxicities by utilizing angled insertions and freeing implantations from constraints applied by the 0.5 cm-spaced template used in the TRUS method. Within our group, Lin et al. have designed a new type of LDR source. The "directional" source is a seed designed to be partially shielded. Thus, a directional, or anisotropic, source does not emit radiation in all directions. The source can be oriented to irradiate cancerous tissues while sparing normal ones. This type of source necessitates a new, highly accurate method for localization in 6 degrees of freedom. A robot is the best way to accomplish this task accurately. The following presentation of work describes the invention and optimization of a new prostate brachytherapy robot that fulfills these goals. Furthermore, some research has been dedicated to the use of the robot to perform needle insertion tasks (brachytherapy, biopsy, RF ablation, etc.) in nearly any other soft tissue in the body. This can be accomplished with the robot combined with automatic, magnetic tracking.

  12. In vitro and in vivo characterization of 4-[125I]iododexetimide binding to muscarinic cholinergic receptors in the rat heart.

    PubMed

    Matsumura, K; Uno, Y; Scheffel, U; Wilson, A A; Dannals, R F; Wagner, H N

    1991-01-01

    4-[125I]iododexetimide binding to muscarinic cholinergic receptors (mAChR) was evaluated in the rat heart. 4-[125I]iododexetimide displayed high in vitro affinity (Kd = 14.0 nM) for rat myocardial mAChR. In vivo, there was high accumulation of 4-[125I]iododexetimide in the rat atrium and ventricle which could be blocked by approximately 60% by preinjection of atropine. In contrast, accumulation of the radiolabeled stereoisomer, 4-[125I]iodolevetimide, was 63% lower than 4-[125I]iodolevetimide and was not blocked by atropine. The blood clearance of 4-[125I]iododexetimide was rapid, providing heart-to-blood ratios of up to 14:1; however, heart-to-lung and heart-to-liver ratios were below unity. The data indicate that 4-[125I]iododexetimide binds potently to rat mAChR. However, since nonspecific binding is relatively high, it is not clear whether iododexetimide labeled with 123I will be useful in SPECT imaging studies of myocardial mAChR. Further studies in humans are indicated. PMID:1988640

  13. Autoradiographic localization of a non-reducible somatostatin analog (/sup 125/I-CGP 23996) binding sites in the rat brain: comparison with membrane binding

    SciTech Connect

    Epelbaum, J.; Dussaillant, M.; Enjalbert, A.; Kordon, C.; Rostene, W.

    1985-07-01

    The regional distribution of somatostatin binding sites in the rat brain was determined by quantitative autoradiography, using /sup 125/I-CGP 23996, a non-reducible somatostatin analog. In preliminary experiments, kinetic properties of /sup 125/I-CGP 23996 binding to rat brain membranes and slide mounted frozen brain sections were compared and found similar. In addition, distribution of /sup 125/I-CGP 23996 and /sup 125/I-N-Tyr-SRIF14 binding sites on membrane prepared from 10 different rat brain structures were closely correlated (r = 0.91, 2 p less than 0.01), indicating that the non-reducible analog recognizes the same binding site as the Tyr-extended native peptide. Highest levels of /sup 125/I-CGP 23996 binding sites were found in anterior temporal, frontal and cingular cortex as well as hippocampus. Moderate levels were found in the remaining part of the limbic system including amygdala, olfactory tubercles and bed nucleus of the stria terminalis. In the brain stem, nuclei involved in the auditory system such as the ventral cochlear nucleus and the superior olive nucleus, contained high levels of /sup 125/I-CGP 23996 binding sites. The distribution of /sup 125/I-CGP 23996 binding sites roughly correlated with that of the endogenous peptide in most structures, except in the mediobasal hypothalamus.

  14. Effect of edema, relative biological effectiveness, and dose heterogeneity on prostate brachytherapy

    SciTech Connect

    Wang, Jian Z.; Mayr, Nina A.; Nag, Subir; Montebello, Joseph; Gupta, Nilendu; Samsami, Nina; Kanellitsas, Christos

    2006-04-15

    Many factors influence response in low-dose-rate (LDR) brachytherapy of prostate cancer. Among them, edema, relative biological effectiveness (RBE), and dose heterogeneity have not been fully modeled previously. In this work, the generalized linear-quadratic (LQ) model, extended to account for the effects of edema, RBE, and dose heterogeneity, was used to assess these factors and their combination effect. Published clinical data have shown that prostate edema after seed implant has a magnitude (ratio of post- to preimplant volume) of 1.3-2.0 and resolves exponentially with a half-life of 4-25 days over the duration of the implant dose delivery. Based on these parameters and a representative dose-volume histogram (DVH), we investigated the influence of edema on the implant dose distribution. The LQ parameters ({alpha}=0.15 Gy{sup -1} and {alpha}/{beta}=3.1 Gy) determined in earlier studies were used to calculate the equivalent uniform dose in 2 Gy fractions (EUD{sub 2}) with respect to three effects: edema, RBE, and dose heterogeneity for {sup 125}I and {sup 103}Pd implants. The EUD{sub 2} analysis shows a negative effect of edema and dose heterogeneity on tumor cell killing because the prostate edema degrades the dose coverage to tumor target. For the representative DVH, the V{sub 100} (volume covered by 100% of prescription dose) decreases from 93% to 91% and 86%, and the D{sub 90} (dose covering 90% of target volume) decrease from 107% to 102% and 94% of prescription dose for {sup 125}I and {sup 103}Pd implants, respectively. Conversely, the RBE effect of LDR brachytherapy [versus external-beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy] enhances dose effect on tumor cell kill. In order to balance the negative effects of edema and dose heterogeneity, the RBE of prostate brachytherapy was determined to be approximately 1.2-1.4 for {sup 125}I and 1.3-1.6 for {sup 103}Pd implants. These RBE values are consistent with the RBE data published in the

  15. (-)(125I)-iodopindolol, a new highly selective radioiodinated beta-adrenergic receptor antagonist: measurement of beta-receptors on intact rat astrocytoma cells

    SciTech Connect

    Barovsky, K.; Brooker, G.

    1980-01-01

    (-)-Pindolol, one of the most potent beta-adrenergic receptor antagonists, was radioiodinated using chloramine-T oxidation of carrier-free Na 125I and separated from unreacted pindolol to yield 2200 Ci/mmole (-)-(125I)-iodopindolol ((-)-(125I)-IPin). Mass and ultraviolet spectra confirmed that the iodination occurred on the indole ring, presumably at the 3 position. The binding of radiolabeled (-)-(125I)-IPin to beta-adrenergic receptors has been studied using intact C6 rat astrocytoma cells (2B subclone) grown in monolayer cultures. Binding of (-)(125IPin was saturable with time and concentration. Using 13 pM (-)-(125I)IPin, binding equilibrium was reached in 90 min at 21-22 degrees C. The reverse rate constant was 0.026 min-1 at 21/sup 0/C. Specific binding (expressed as 1 microM(-)-propranolol displaceable counts) of (-)-(125I)-IPin was 95% of total binding. Scatchard analysis of (-)-(125I)-I)Pin binding revealed approximately 4300 receptors/cell and a dissociation constant of 30 pM. This was in excellent agreement with the kinetically determined dissociation constant of 35 pM. Displacement by propranolol and isoproterenol showed that (-)-(125I)-IPin binding sites were pharmacologically and stereospecifically selective. These results indicate that (-)-(125I)-IPin, a pure (-)-stereoisomer, high specific activity radioligand, selectively binds to beta-adrenergic receptors in whole cells with a high percentage of specific binding and should therefore be useful in the study and measurement of cellular beta-adrenergic receptors.

  16. Effects of different batches of /sup 125/iodine on properties of /sup 125/I-hFSH and characteristics of radioligand-receptor assays

    SciTech Connect

    Melson, B.E.; Sluss, P.M.; Reichert, L.E. Jr.

    1987-02-01

    Radioiodination of highly purified human follicle-stimulating hormone (hFSH) (4000 IU/mg) was performed every other week for 23 weeks using 2 mCI carrier free Na/sup 125/I (Amersham Corp., 15 mCi/micrograms I2) in the presence of lactoperoxidase. Incorporation of /sup 125/I into hFSH was determined by the method of R. C. Greenwood, W. M. Hunter, and J. S. Grover (1963) Biochem. J. 89, 114). Hormone binding was studied in vitro under steady-state conditions (16 h, 20 degrees C) using different calf testis membrane preparations having similar receptor characteristics. Each /sup 125/I-hFSH preparation was characterized for maximum bindability, specific activity of bindable radioligand as determined by self-displacement analysis, and by determination of Ka and Rt. Incorporation of /sup 125/I into FSH was relatively constant over the large number of experiments (62.4 +/- 6.4 microCi/micrograms; n = 23). By comparison, however, specific radioactivity of the receptor bindable fraction of /sup 125/I-hFSH was related to the lot of /sup 125/I utilized, and was significantly (P less than or equal to 0.01) lower and more variable (28.7 +/- 10.5 microCi/micrograms). Maximum bindability of /sup 125/I-hFSH was not correlated to specific activity (r = 0.06) but was negatively correlated to hFSH /sup 125/I incorporation (r = -0.47; P less than or equal to 0.05). These observations demonstrate the need to assess the quality of each batch of radioligand before undertaking radioligand-receptor assays and suggest that differences in Na/sup 125/I lots affect specific radioactivity of the radioligand and its receptor binding characteristics.

  17. [Brachytherapy for oesophageal cancer].

    PubMed

    Wong, S; Hennequin, C; Quero, L

    2013-04-01

    The main indication of oesophageal brachytherapy is palliative: it can improve dysphagia in patients with a tumor not suitable for surgery or chemoradiotherapy. A randomized clinical trial showed that survival without dysphagia and quality of life was improved by endoluminal brachytherapy in comparison to self-expansible metallic stents. It also increases the duration of palliation after laser deobstruction. Its role as a curative treatment of locally advanced tumors is still discussed: in combination with external beam radiotherapy, it seems that brachytherapy increased the rate of severe toxicity (haemorrhages, fistula, stenosis). In superficial lesions, brachytherapy with or without external beam radiotherapy seems logical but large prospective studies are missing in this setting. PMID:23603254

  18. Pharmacological characterization of [(125)I]CHIBA-1006 binding, a new radioligand for α7 nicotinic acetylcholine receptors, to rat brain membranes.

    PubMed

    Wu, Jin; Toyohara, Jun; Tanibuchi, Yuko; Fujita, Yuko; Zhang, Jichun; Chen, Hongxian; Matsuo, Masaaki; Wang, Rong Fu; Hashimoto, Kenji

    2010-11-11

    The α7 nicotinic acetylcholine receptors (nAChRs) play an important role in the pathophysiology of neuropsychiatric diseases such as schizophrenia and Alzheimer's disease. However, there are currently no suitable small molecule radioligands for imaging α7 nAChRs in the brain. In this study, we synthesized the novel radioligand [(125)I]4-iodophenyl 1,4-diazaicyclo[3.2.2]nonane-4-carboxylate ([(125)I]CHIBA-1006), a iodine-derivative of the selective α7 nAChR agonist SSR180711, and studied the characterization of [(125)I]CHIBA-1006 binding to rat brain membranes. The assays of [(125)I]CHIBA-1006 binding to rat brain membranes were performed at 4°C. The presence of a single saturable high-affinity binding component for [(125)I]CHIBA-1006 in the rat brain was shown. Scatchard analysis revealed an apparent equilibrium dissociation constant (K(d)) of 88.2±21.4nM and a maximal number of binding sites (B(max)) of 65.4±6.8fmol/mg protein (mean±SEM, n=4). The specific binding of [(125)I]CHIBA-1006 was inhibited by a number of α7 nAChR-selective ligands (e.g., unlabeled CHIBA-1006, SSR180711, CHIBA-1001, MG624 and A844606), suggesting a similarity among α7 nAChR pharmacological profiles. In contrast, α-bungarotoxin, MLA, and nicotine showed very weak affinity for [(125)I]CHIBA-1006 binding. The regional distribution of [(125)I]CHIBA-1006 binding to crude membranes from dissected regions of the rat brain was different from that of [(125)I]α-bungarotoxin binding, suggesting that [(125)I]CHIBA-1006 binding sites may not be identical to [(125)I]α-bungarotoxin binding sites in the rat brain. The present findings suggest that [(125)I]CHIBA-1006 would be a useful new small molecule radioligand for α7 nAChRs in the brain. PMID:20816767

  19. Extraction of (129)I and (127)I via combustion from organic rich samples using (125)I as a quantitative tracer.

    PubMed

    Herod, Matthew N; Cornett, R Jack; Clark, Ian D; Kieser, W E; Jean, Gilles St

    2014-12-01

    Iodine-129 ((129)I) is a biophilic, naturally occurring radioisotope (half-life: 1.57 × 10(7) years) that has been released in large quantities by nuclear fuel reprocessing. This iodine has cycled throughout the globe and chiefly the northern hemisphere and can be found in a wide variety of environmental materials, particularly organic rich soil and organic matter. Extracting iodine reliably from solid samples has been done by a variety of methods, however, pyrohydrolysis has been the most widely used. There is a wide variation between existing pyrohydrolysis techniques and this raises questions about the quantitative recovery of iodine from method to method. In order to quantify iodine recovery from pyrohydrolysis we have spiked samples with an iodine-125 radiotracer prior to combustion and trapping in an alkaline solution. Inorganic (125)I tracer was used as well as humic acid labeled with (125)I to simulate the behavior of (129)I and (127)I in complex organic substances and extract iodine regardless of how it is partitioned. Using these tracers we explored the effect on recovery of (125)I under a variety of combustion parameters. These include carrier gas flow rate and iodine volatilization temperature. We observed that the best recoveries of (125)I were at flow rates between 400 and 800 mL/min and most (125)I recoveries were above 85%. The experiment to determine the temperature at which iodine volatilizes from the sample showed two distinct trends for the release of iodine. One trend showed that most iodine is released at approximately 525 °C, while the other trend showed that the samples needed to reach 800 °C and remain there for at least an hour. These findings illustrate the usefulness and importance of using a quantitative recovery tracer for every iodine extraction. We then combusted and precipitated several Atlantic Ocean seaweed and standard reference materials for AMS analysis as AgI. The (129)I concentration of the seaweed ranged between 4

  20. Identification of extrastriatal dopamine D2 receptors in post mortem human brain with [125I]epidepride.

    PubMed

    Kessler, R M; Whetsell, W O; Ansari, M S; Votaw, J R; de Paulis, T; Clanton, J A; Schmidt, D E; Mason, N S; Manning, R G

    1993-04-23

    The regional distribution of striatal and extrastriatal dopamine D2 receptors in human brain was studied in vitro with (S)-N-[(1-ethyl-2- pyrrolidinyl)methyl]-5-[125I]iodo-2,3-dimethoxybenzamide, [125I]epidepride, using post mortem brain specimens from six subjects. Scatchard analysis of the saturation equilibrium binding in twenty-three regions of post mortem brain revealed highest levels of binding in the caudate (16.5 pmol/g tissue) and putamen (16.6 pmol/g tissue) with lower levels seen in the globus pallidus (7.0 pmol/g tissue), nucleus accumbens (7.2 pmol/g tissue), hypothalamus (1.8 pmol/g tissue), pituitary (1.3 pmol/g tissue), substantia innominata (1.0 pmol/g tissue), and amygdala (0.87 pmol/g tissue). Of note was the presence of dopamine D2 receptors in the four thalamic nuclei studied, i.e. anterior nucleus (1.0 pmol/g tissue), dorsomedial nucleus (0.96 pmol/g tissue), ventral nuclei (0.72 pmol/g tissue), and pulvinar (0.86 pmol/g tissue), at levels comparable to the amygdala (0.87 pmol/g tissue) and considerably higher than levels seen in anterior cingulate (0.26 pmol/g tissue) or anterior hippocampus (0.36 pmol/g tissue). The frontal cortex had very low levels of dopamine D2 receptors (0.17-0.20 pmol/g tissue) while the inferior and medial temporal cortex had relatively higher levels (0.31-0.46 pmol/g tissue). Inhibition of [125I]epidepride binding by a variety of neurotransmitter ligands to striatal, ventral thalamic and inferior temporal cortical homogenates demonstrated that [125I]epidepride binding was potently inhibited only by dopamine D2 ligands. The present study demonstrates that dopamine D2 receptors are present in basal ganglia, many limbic regions, cortex and in the thalamus. The density of thalamic D2 receptors is comparable to many limbic regions and is considerably higher than in cortex.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8099521

  1. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    NASA Astrophysics Data System (ADS)

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

  2. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications.

    PubMed

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled (125)I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10(-6) simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. PMID:26061230

  3. Interstitial Lung Diseases

    MedlinePlus

    Interstitial lung disease is the name for a large group of diseases that inflame or scar the lungs. The inflammation and ... is responsible for some types of interstitial lung diseases. Specific types include Black lung disease among coal ...

  4. Radioimmunoanalysis of delta-9-THC in blood by means of an /sup 125/I tracer. [Delta-9-Tetrahydrocannabinol

    SciTech Connect

    Owens, S.M.; McBay, A.J.; Reisner, H.M.

    1982-01-01

    A radioimmunoassay for delta-9-THC in plasma, whole blood, or hemolyzed blood specimens has been presented. Samples and standards were diluted with methanol and centrifuged. An aliquot of the supernatant fluid was incubated with RIA buffer, /sup 125/I-labeled delta-8-THC and rabbit anti-THC serum. Solid phase goat anti-rabbit immunoglobulins were added to separate bound from free THC. After centrifugation the supernatant fluid was aspirated and the radioactivity of the precipitate was counted in a gamma counter. The concentration of THC was calculated from a standard curve using the logit-log transformation of the average counts of duplicate tubes. The assay had several advantages. Methanol dilution gave better results than direct analysis. The /sup 125/I-labeled THC had high specific activity and could be counted in a gamma counter. The immunological separation of antibody-bound THC from free THC was better than separation techniques using ammonium sulfate and activated charcoal. THC was determined in 0.1 ml of sample with a sensitivity of 1.5 ng/ml in plasma and 3.0 ng/ml in hemolyzed blood.

  5. Accumulation of sup 125 I-factor XI in atheroma of rabbit with hereditary hyperlipidemia (WHHL-rabbit)

    SciTech Connect

    Komiyama, Y.; Masuda, M.; Murakami, T.; Nishikado, H.; Egawa, H.; Nishimura, T.; Morii, S.; Murata, K. )

    1989-10-01

    We have studied the turnover and accumulation of rabbit factor XI (F.XI) in atherosclerotic lesion in Watanabe-hereditable hyperlipidemic rabbit (WHHL rabbit) to reveal the participation of blood coagulation in atherosclerotic lesion. Rabbit F.XI was iodinated and administered intravenously to WHHL rabbits and Japanese white rabbits. The turnover of {sup 125}I-rabbit F.XI was significantly faster in WHHL rabbits (T1/2 = 2.84 +/- 0.44 days) than in normal rabbits (T1/2 = 4.44 +/- 0.42 days). The thoracic aorta of WHHL rabbit was strongly labelled with {sup 125}I-rabbit F.XI, in sections obtained after 5 days by en-face autoradiography, whereas no radioactivity was detected in normal aorta. By an immunohistochemical study of WHHL rabbit aorta, we confirmed that many F.XI- and fibrin-related compounds existed in the atheroma, whereas albumin did not in these area. These results suggest that the activation of F.XI proceeds on the atherosclerotic lesions of WHHL rabbits.

  6. Distribution of 125I-ferrotransferrin binding sites in the mesencephalon of control subjects and patients with Parkinson's disease.

    PubMed

    Faucheux, B A; Hirsch, E C; Villares, J; Selimi, F; Mouatt-Prigent, A; Javoy-Agid, F; Hauw, J J; Agid, Y

    1993-06-01

    Iron is abnormally accumulated in the substantia nigra pars compacta of patients with Parkinson's disease (PD). Because neuronal and glial iron uptake seems to be mediated by the binding of ferrotransferrin to a specific high-affinity receptor on the cell surface, the number of transferrin receptors could be altered in this disease. The regional distribution of specific binding sites for human 125I-diferric transferrin has been studied in the mesencephalon, on cryostat-cut sections from autopsy brains of control subjects and parkinsonian patients by in vitro autoradiography. Densities of binding sites were highest in the central gray substance (approximately 10 fmol/mg of tissue equivalent), intermediate in the catecholaminergic cell group A8, superior colliculus, and ventral tegmental area, and almost nonexistent in the substantia nigra. The density of 125I-transferrin binding sites was not significantly different between parkinsonian and control brains in any region analyzed. These results show that in the mesencephalon the regional density of transferrin binding sites is lowest in the dopaminergic cell groups, which are the most vulnerable to PD, and suggest that iron does not accumulate through an increased density of transferrin receptors at the level of the substantia nigra. PMID:8492137

  7. Use of 125I- and 51Cr-Labeled Albumin for the Measurement of Gastrointestinal and Total Albumin Catabolism*

    PubMed Central

    Kerr, Robert M.; Bois, John J. Du; Holt, Peter R.

    1967-01-01

    A method for the simultaneous measurement of gastrointestinal protein loss and total albumin turnover entailing the use of a combination of 125iodine- and 51chromium-labeled albumin is described. Albumin turnover was calculated by the measurement of albumin-125I plasma decay and cumulative urinary excretion, and the results obtained agreed closely with previous studies utilizing albumin-131I. Gastrointestinal catabolism was calculated from the rate of fecal excretion of 51Cr and the specific activity of plasma albumin-51Cr, and these data were related to the calculated albumin turnover results. During the period of 6-14 days after administration, the ratio of specific activties of albumin-125I and -51Cr in plasma and in extravascular spaces or gastric and biliary secretions remained almost identical. Fecal excretion of 51Cr was also quite stable at this time. In six normal subjects gastrointestinal catabolism accounted for less than 10% of total albumin catabolism. Excessive gastrointestinal protein losses did not contribute to the low serum albumin in three patients with cirrhosis or in two adults with the nephrotic syndrome. Multiple mechanisms leading to hypoalbuminemia were demonstrated in other subjects with a variety of gastrointestinal disorders. Images PMID:5630419

  8. Autoradiographic evidence for two classes of mu opioid binding sites in rat brain using (/sup 125/I)FK33824

    SciTech Connect

    Rothman, R.B.; Jacobson, A.E.; Rice, K.C.; Herkenham, M.

    1987-11-01

    Previous studies demonstrated that pretreatment of brain membranes with the irreversible mu antagonist, beta-funaltrexamine (beta-FNA), partially eliminated mu binding sites (25,35), consistent with the existence of two mu binding sites distinguished by beta-FNA. This paper tests the hypothesis that the FNA-sensitive and FNA-insensitive mu binding sites have different anatomical distributions in rat brain. Prior to autoradiographic visualization of mu binding sites, (/sup 3/H)oxymorphone, (/sup 3/H)D-ala2-MePhe4, Gly-ol5-enkephalin (DAGO), and (/sup 125/I)D-ala2-Me-Phe4-met(o)-ol)enkephalin (FK33824) were shown to selectively label mu binding sites using slide mounted sections of molded minced rat brain. As found using membranes, beta-FNA eliminated only a portion of mu binding sites. Autoradiographic visualization of mu binding sites using the mu-selective ligand (/sup 125/I)FK33824 in control and FNA-treated sections of rat brain demonstrated that the proportion of mu binding sites sensitive to beta-FNA varied across regions of the brain, particularly the dorsal thalamus, ventrobasal complex and the hypothalamus, providing anatomical data supporting the existence of two classes of mu binding sites in rat brain.

  9. Biotin radioligand assay with an /sup 125/I-labeled biotin derivative, avidin, and avidin double-antibody reagents

    SciTech Connect

    Livaniou, E.; Evangelatos, G.P.; Ithakissios, D.S.

    1987-11-01

    We describe a new radioligand assay for determining biotin in biological fluids by using a mixture of N-(beta-(4-OH-3-125I-phenyl)ethyl)- and N-(beta-(4-OH-3,5-di-125I-phenyl)ethyl)biotinamides as radiotracer, avidin as a binding protein, and an avidin double-antibody as a separation reagent. The radiotracer is synthesized by coupling (at pH 8.5, 20-22 degrees C, 90 min) N-hydroxysuccinimidobiotin to radioiodinated tyramine. The assay curve is linear and the assay itself is sensitive (less than 10 ng/L), reproducible (intra- and interassay CVs 4.1% and 7.0%, respectively), and allows the simultaneous handling of more than 100 samples in less than 4 h. Serum samples from apparently normal subjects contained 100-840 ng of biotin per liter (mean 340 ng/L). Pregnant women had low concentrations of biotin (100-300 ng/L) in their serum. Patients undergoing chronic hemodialysis treatment showed high concentrations (0.5-3.0 micrograms/L), which may be ascribable to the inability of avidin, which was used as the assay binding protein, to distinguish biotin from biotinyl derivatives with an intact ureido ring.

  10. A Comparison of Acute and Chronic Toxicity for Men With Low-Risk Prostate Cancer Treated With Intensity-Modulated Radiation Therapy or {sup 125}I Permanent Implant

    SciTech Connect

    Eade, Thomas N.; Horwitz, Eric M. Ruth, Karen; Buyyounouski, Mark K.; D'Ambrosio, David J.; Feigenberg, Steven J.; Chen, David Y.T.; Pollack, Alan

    2008-06-01

    Purpose: To compare the toxicity and biochemical outcomes of intensity-modulated radiation therapy (IMRT) and {sup 125}I transperineal permanent prostate seed implant ({sup 125}I) for patients with low-risk prostate cancer. Methods and Materials: Between 1998 and 2004, a total of 374 low-risk patients (prostate-specific antigen < 10 ng/ml, T1c-T2b, Gleason score of 6 or less, and no neoadjuvant hormones) were treated at Fox Chase Cancer Center (216 IMRT and 158 {sup 125}I patients). Median follow-up was 43 months for IMRT and 48 months for {sup 125}I. The IMRT prescription dose ranged from 74-78 Gy, and {sup 125}I prescription was 145 Gy. Acute and late gastrointestinal (GI) and genitourinary (GU) toxicity was recorded by using a modified Radiation Therapy Oncology Group scale. Freedom from biochemical failure was defined by using the Phoenix definition (prostate-specific antigen nadir + 2.0 ng/ml). Results: Patients treated by using IMRT were more likely to be older and have a higher baseline American Urological Association symptom index score, history of previous transurethral resection of the prostate, and larger prostate volumes. On multivariate analysis, IMRT was an independent predictor of lower acute and late Grade 2 or higher GU toxicity and late Grade 2 or higher GI toxicity. Three-year actuarial estimates of late Grade 2 or higher toxicity were 2.4% for GI and 3.5% for GU by using IMRT compared with 7.7% for GI and 19.2% for GU for {sup 125}I, respectively. Four-year actuarial estimates of freedom from biochemical failure were 99.5% for IMRT and 93.5% for {sup 125}I (p = 0.09). Conclusions: The IMRT and {sup 125}I produce similar outcomes, although IMRT appears to have less acute and late toxicity.

  11. Sodium-dependent isomerization of dopamine D-2 receptors characterized using [125I]epidepride, a high-affinity substituted benzamide ligand.

    PubMed

    Neve, K A; Henningsen, R A; Kinzie, J M; De Paulis, T; Schmidt, D E; Kessler, R M; Janowsky, A

    1990-03-01

    We have characterized the in vitro binding of a new ligand, [125I]epidepride, and used this substituted benzamide to assess the sensitivity of dopamine D-2 receptors to sodium. Both direct and indirect binding studies with [125I]epidepride and unlabeled epidepride, respectively, demonstrated that the affinity of D-2 receptors for the ligand was decreased from 20 to 30 pM in the presence of sodium to 350 to 500 pM in the absence of sodium. The density of binding sites for [125I]epidepride was identical in the presence and absence of NaCl. The time courses for association of [125I]epidepride to and dissociation from D-2 receptors in the presence of sodium were not consistent with simple bimolecular reactions, suggesting the possibility of a sodium-dependent ligand-induced receptor isomerization. Thus, dissociation of [125I]epidepride was biphasic in the presence of sodium, but monophasic in the absence of sodium. The rank order of potency for inhibition of [125I]epidepride binding by drugs was identical in rat striatum and cells expressing a D-2 receptor cDNA, and similar to the previously described pharmacological profile of D-2 receptors labeled by [3H]spiperone. [125I]Epidepride bound to two classes of binding sites in rat medial prefrontal cortex. One class, present at a density of 10 fmol/mg of protein and with a Kd value of approximately 40 pM, was pharmacologically indistinguishable from D-2 receptors in striatum and transfected cells. The pharmacological profile of the second class of sites was similar to that of alpha-2 adrenergic receptors. [125I]Epidepride had 50- to 100-fold lower affinity (approximately 2 nM) for alpha-2 receptors than for D-2 receptors.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2138666

  12. Inhibitory Effects of PEI-RGD/125I-(αV) ASODN on Growth and Invasion of HepG2 Cells

    PubMed Central

    Cai, Haidong; Qiao, Yu; Sun, Ming; Yuan, Xueyu; Luo, Qiong; Yang, Yuehua; Yuan, Shidong; Lv, Zhongwei

    2015-01-01

    Background To investigate the in vitro inhibitory effects of PEI-RGD/125I-(αV)ASODN (PEI, polyethylenimine; RGD, Arg-Gly-Asp; ASODN, antisense oligodeoxynucleotide) on the growth and invasion of HepG2 cells. Material/Methods ASODN of the integrin αV-subunit was marked with 125I and underwent complexation with PEI-RGD, a PEI derivative. Next, PEI-RGD/125I-(αV) ASODN was introduced into HepG2 cells via receptor-mediated transfection, and its inhibition rate on HepG2 cell growth was tested using the methyl thiazolyl tetrazolium (MTT) method. The effects of PEI-RGD/125I-(αV) ASODN on HepG2 cell invasion ability were evaluated using the Boyden chamber assay. Results 1) The 125I marking rate of (αV) ASODN was 73.78±4.09%, and the radiochemical purity was 96.68±1.38% (greater than 90% even after a 48-h incubation period at 37°C), indicating high stability. 2) The cytotoxicity assays showed that the cell inhibition rates did not differ significantly between the PEI-RGD/125I-(αV)ASODN group and the PEI-RGD/(αV) ASODN group, but they were both significantly higher than in the other groups and were positively correlated (r=0.879) with the dosage within a certain range. 3) The invasion assays showed that the inhibition rate was significantly greater in the PEI-RGD/125I-(αV) ASODN group compared to the other groups. Conclusions PEI-RGD/125I-(αV) ASODN can efficiently inhibit the growth and proliferation of HepG2 cells and can also weaken their invasive ability. PMID:26258995

  13. Photolabeling and radioligand binding of human erythrocyte NaK-ATPase with sup 125 I-derivatives of cymarin and digitoxigenin

    SciTech Connect

    Lowndes, J.M.

    1988-01-01

    NaK-ATPase is an enzyme which maintains Na{sup +} and K{sup +} gradients across the plasma membrane of eukaryotic cells, and is specifically inhibited by cardiac glycosides. The cardiac glycoside binding site is located primarily on the catalytic {alpha} subunit but the glycoprotein {beta} and proteolipid-{gamma} subunits may also contribute to the structure of the site. In order to label the cardiac glycoside binding site of human erythrocytes, four photoaffinity ligands with very high specific radioactivity were synthesized. The compounds, which are abbreviated ({sup 125}I)AISC, ({sup 125}I)AIPP-GluD, ({sup 125}I)AIPP-GalD and ({sup 125}I)IA-GalD, were all effective photolabels for NaK-ATPase as shown by ouabain-protectable, covalent labeling of the {alpha}, {beta}, and proteolipid-{gamma} subunits. In order to study the possible existence of a very high affinity binding site in erythrocyte NaK-ATPase, a carrier-free radioligand, ({sup 125}I)I-TASC, was synthesized; this compound had the same structure as ({sup 125}I)AISC except that a light-sensitive azide group was replaced with a hydroxyl group. Competitive binding assays with cymarin against 0.2 nM ({sup 125}I)I-TASC suggested two classes of erythrocyte binding sites. Scatchard analysis of direct ({sup 125}I)I-TASC binding indicated that the very high affinity, low capacity class of erythrocyte bindings sites had a K{sub D} of 54 pM and a B{sub max} of 23 fmol/mg protein.

  14. Comparison of cyclosporine determinations in whole blood by three different methods. HPLC, /sup 125/I RIA and /sup 3/H RIA

    SciTech Connect

    Huang, W.Y.; Lipsey, A.I.; Cheng, M.H.

    1987-04-01

    The authors have analyzed and compared the cyclosporine concentrations in whole blood specimens from pediatric renal transplant patients using three different methods: high-performance liquid chromatography (HPLC) (5u C18 reverse-phase column), /sup 3/H radioimmunoassay (RIA), and /sup 125/I RIA (substituted /sup 3/H-tracer in Sandoz Kit with /sup 125/I tracer. Results obtained by the /sup 125/I RIA correlated well with results obtained by the /sup 3/H RIA. Both RIA methods had similar correlation with the HPLC method. The /sup 125/I RIA method showed higher sensitivity and greater precision than the /sup 3/H RIA method. The authors conclude that the /sup 125/I RIA method can be used for cyclosporine determination in whole blood specimens. The use of the /sup 125/I RIA provides a simple and rapid method with higher counting efficiency and less background quenching than the /sup 3/H RIA method, which requires cumbersome liquid scintillation counting procedures.

  15. Autoradiographic localization of supraspinal kappa-opioid receptors with (/sup 125/I-Tyr1, D-Pro10)dynorphin A-(1-11)

    SciTech Connect

    Jomary, C.; Gairin, J.E.; Cros, J.; Meunier, J.C.

    1988-01-01

    (/sup 125/I-Tyr1, D-Pro10)dynorphin A-(1-11) (/sup 125/I-DP-DYN), an opioid peptide analogue that has previously been shown to be kappa selective, displays specific, saturable, and high-affinity (Kd = 0.3 nM) binding in slide-mounted sections from nerve tissue. We have used /sup 125/I-DPDYN to autoradiographically visualize supraspinal kappa-opioid receptor sites in rats, guinea pigs, and rabbits. The autoradiographic dispositions of /sup 125/I-DPDYN in sections from cerebellum are clearly different in guinea pig and rabbit, suggesting that kappa receptors have different functions in this organ of the two species. Autoradiograms from /sup 125/I-DPDYN-labeled brain sections also reveal major species differences, in particular in thalamus, which is densely labeled in rabbit and considerably less so in rat and guinea pig. The data show that /sup 125/I-DPDYN is a useful probe to visualize kappa-opioid receptor sites in nerve tissue sections directly and rapidly.

  16. Interstitially implanted I125 for prostate cancer using transrectal ultrasound

    SciTech Connect

    Greenburg, S.; Petersen, J.; Hansen-Peters, I.; Baylinson, W. )

    1990-11-01

    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.

  17. /sup 125/I-BW-A844U, an antagonist radioligand with high affinity and selectivity for adenosine A1 receptors, and /sup 125/I-azido-BW-A844U, a photoaffinity label

    SciTech Connect

    Patel, A.; Craig, R.H.; Daluge, S.M.; Linden, J.

    1988-06-01

    3-(4-Amino)phenethyl-1-propyl-8-cyclopentylxanthine (BW-A844U) has been synthesized and shown to bind with high affinity to adenosine A1 receptors of bovine brain membranes (KD = 0.23 nM). This compound is highly selective for A1 receptors; the KI for binding to A2 receptors of human platelet membranes is 2.0 microM (A2/A1 ratio = 8700). Radioiodination of the 3-aminophenethyl group resulted in 125I-BW-A844U, a radioligand that retains high affinity for A1 receptors in bovine brain membranes (KD = 0.14 nM) and to 3-((3-cholamidopropyl)-dimethylammonio)-1-propane sulfonate-solubilized receptors (KD = 0.34 nM). Specific binding of 125I-BW-A844U represented greater than 90% of the total binding at the KD. From the association constant (K1 = 5.0 X 10(8) M-1min-1) and the dissociation constant (K-1 = 0.064 min-1), the kinetic KD (K-1/K1) in membranes was calculated to be 0.13 nM. NaCl (1 M) had little effect on the binding affinity of 125I-BW-A844U, in contrast to the large effect of salt on the binding affinity of acidic antagonist radioligands. 8-Sulfophenyltheophylline inhibited radioligand binding with a Hill coefficient of 1.0, indicative of a single affinity binding state for the antagonist. By comparison, two distinct agonist affinity states of A1 receptors for the agonist (R)-phenylisopropyladenosine could be resolved, a high affinity state (62%, KH = 74 pM) and a low affinity state (KL = 3.83 nM). The addition of 0.1 mM guanylylimidodiphosphate converted all receptors to the low affinity state. Addition of NaCl (0.5 M) decreased the fraction of receptors in the high affinity state and increased both KH and KL, suggesting that NaCl alters coupling of receptors to G proteins and influences the conformation of the receptor polypeptide, whether or not the receptor is coupled to a G protein.

  18. Dosimetric audit in brachytherapy

    PubMed Central

    Bradley, D A; Nisbet, A

    2014-01-01

    Dosimetric audit is required for the improvement of patient safety in radiotherapy and to aid optimization of treatment. The reassurance that treatment is being delivered in line with accepted standards, that delivered doses are as prescribed and that quality improvement is enabled is as essential for brachytherapy as it is for the more commonly audited external beam radiotherapy. Dose measurement in brachytherapy is challenging owing to steep dose gradients and small scales, especially in the context of an audit. Several different approaches have been taken for audit measurement to date: thimble and well-type ionization chambers, thermoluminescent detectors, optically stimulated luminescence detectors, radiochromic film and alanine. In this work, we review all of the dosimetric brachytherapy audits that have been conducted in recent years, look at current audits in progress and propose required directions for brachytherapy dosimetric audit in the future. The concern over accurate source strength measurement may be essentially resolved with modern equipment and calibration methods, but brachytherapy is a rapidly developing field and dosimetric audit must keep pace. PMID:24807068

  19. Penile brachytherapy: Results for 49 patients

    SciTech Connect

    Crook, Juanita M. . E-mail: juanita.crook@rmp.uhn.on.ca; Jezioranski, John; Grimard, Laval; Esche, Bernd; Pond, G.

    2005-06-01

    Purpose: To report results for 49 men with squamous cell carcinoma (SCC) of the penis treated with primary penile interstitial brachytherapy at one of two institutions: the Ottawa Regional Cancer Center, Ottawa, and the Princess Margaret Hospital, Toronto, Ontario, Canada. Methods and Materials: From September 1989 to September 2003, 49 men (mean age, 58 years; range, 22-93 years) had brachytherapy for penile SCC. Fifty-one percent of tumors were T1, 33% T2, and 8% T3; 4% were in situ and 4% Tx. Grade was well differentiated in 31%, moderate in 45%, and poor in 2%; grade was unspecified for 20%. One tumor was verrucous. All tumors in Toronto had pulsed dose rate (PDR) brachytherapy (n = 23), whereas those in Ottawa had either Iridium wire (n 22) or seeds (n = 4). Four patients had a single plane implant with a plastic tube technique, and all others had a volume implant with predrilled acrylic templates and two or three parallel planes of needles (median, six needles). Mean needle spacing was 13.5 mm (range, 10-18 mm), mean dose rate was 65 cGy/h (range, 33-160 cGy/h), and mean duration was 98.8 h (range, 36-188 h). Dose rates for PDR brachytherapy were 50-61.2 cGy/h, with no correction in total dose, which was 60 Gy in all cases. Results: Median follow-up was 33.4 months (range, 4-140 months). At 5 years, actuarial overall survival was 78.3% and cause-specific survival 90.0%. Four men died of penile cancer, and 6 died of other causes with no evidence of recurrence. The cumulative incidence rate for never having experienced any type of failure at 5 years was 64.4% and for local failure was 85.3%. All 5 patients with local failure were successfully salvaged by surgery; 2 other men required penectomy for necrosis. The soft tissue necrosis rate was 16% and the urethral stenosis rate 12%. Of 8 men with regional failure, 5 were salvaged by lymph node dissection with or without external radiation. All 4 men with distant failure died of disease. Of 49 men, 42 had an intact

  20. Comparison of dose calculation methods for brachytherapy of intraocular tumors

    SciTech Connect

    Rivard, Mark J.; Chiu-Tsao, Sou-Tung; Finger, Paul T.; Meigooni, Ali S.; Melhus, Christopher S.; Mourtada, Firas; Napolitano, Mary E.; Rogers, D. W. O.; Thomson, Rowan M.; Nath, Ravinder

    2011-01-15

    Purpose: To investigate dosimetric differences among several clinical treatment planning systems (TPS) and Monte Carlo (MC) codes for brachytherapy of intraocular tumors using {sup 125}I or {sup 103}Pd plaques, and to evaluate the impact on the prescription dose of the adoption of MC codes and certain versions of a TPS (Plaque Simulator with optional modules). Methods: Three clinical brachytherapy TPS capable of intraocular brachytherapy treatment planning and two MC codes were compared. The TPS investigated were Pinnacle v8.0dp1, BrachyVision v8.1, and Plaque Simulator v5.3.9, all of which use the AAPM TG-43 formalism in water. The Plaque Simulator software can also handle some correction factors from MC simulations. The MC codes used are MCNP5 v1.40 and BrachyDose/EGSnrc. Using these TPS and MC codes, three types of calculations were performed: homogeneous medium with point sources (for the TPS only, using the 1D TG-43 dose calculation formalism); homogeneous medium with line sources (TPS with 2D TG-43 dose calculation formalism and MC codes); and plaque heterogeneity-corrected line sources (Plaque Simulator with modified 2D TG-43 dose calculation formalism and MC codes). Comparisons were made of doses calculated at points-of-interest on the plaque central-axis and at off-axis points of clinical interest within a standardized model of the right eye. Results: For the homogeneous water medium case, agreement was within {approx}2% for the point- and line-source models when comparing between TPS and between TPS and MC codes, respectively. For the heterogeneous medium case, dose differences (as calculated using the MC codes and Plaque Simulator) differ by up to 37% on the central-axis in comparison to the homogeneous water calculations. A prescription dose of 85 Gy at 5 mm depth based on calculations in a homogeneous medium delivers 76 Gy and 67 Gy for specific {sup 125}I and {sup 103}Pd sources, respectively, when accounting for COMS-plaque heterogeneities. For off

  1. Comparison of dose calculation methods for brachytherapy of intraocular tumors

    PubMed Central

    Rivard, Mark J.; Chiu-Tsao, Sou-Tung; Finger, Paul T.; Meigooni, Ali S.; Melhus, Christopher S.; Mourtada, Firas; Napolitano, Mary E.; Rogers, D. W. O.; Thomson, Rowan M.; Nath, Ravinder

    2011-01-01

    Purpose: To investigate dosimetric differences among several clinical treatment planning systems (TPS) and Monte Carlo (MC) codes for brachytherapy of intraocular tumors using 125I or 103Pd plaques, and to evaluate the impact on the prescription dose of the adoption of MC codes and certain versions of a TPS (Plaque Simulator with optional modules). Methods: Three clinical brachytherapy TPS capable of intraocular brachytherapy treatment planning and two MC codes were compared. The TPS investigated were Pinnacle v8.0dp1, BrachyVision v8.1, and Plaque Simulator v5.3.9, all of which use the AAPM TG-43 formalism in water. The Plaque Simulator software can also handle some correction factors from MC simulations. The MC codes used are MCNP5 v1.40 and BrachyDose∕EGSnrc. Using these TPS and MC codes, three types of calculations were performed: homogeneous medium with point sources (for the TPS only, using the 1D TG-43 dose calculation formalism); homogeneous medium with line sources (TPS with 2D TG-43 dose calculation formalism and MC codes); and plaque heterogeneity-corrected line sources (Plaque Simulator with modified 2D TG-43 dose calculation formalism and MC codes). Comparisons were made of doses calculated at points-of-interest on the plaque central-axis and at off-axis points of clinical interest within a standardized model of the right eye. Results: For the homogeneous water medium case, agreement was within ∼2% for the point- and line-source models when comparing between TPS and between TPS and MC codes, respectively. For the heterogeneous medium case, dose differences (as calculated using the MC codes and Plaque Simulator) differ by up to 37% on the central-axis in comparison to the homogeneous water calculations. A prescription dose of 85 Gy at 5 mm depth based on calculations in a homogeneous medium delivers 76 Gy and 67 Gy for specific 125I and 103Pd sources, respectively, when accounting for COMS-plaque heterogeneities. For off-axis points

  2. Canadian prostate brachytherapy in 2012

    PubMed Central

    Keyes, Mira; Crook, Juanita; Morris, W. James; Morton, Gerard; Pickles, Tom; Usmani, Nawaid; Vigneault, Eric

    2013-01-01

    Prostate brachytherapy can be used as a monotherapy for low- and intermediate-risk patients or in combination with external beam radiation therapy (EBRT) as a form of dose escalation for selected intermediate- and high-risk patients. Prostate brachytherapy with either permanent implants (low dose rate [LDR]) or temporary implants (high dose rate [HDR]) is emerging as the most effective radiation treatment for prostate cancer. Several large Canadian brachytherapy programs were established in the mid- to late-1990s. Prostate brachytherapy is offered in British Columbia, Alberta, Manitoba, Ontario, Quebec and New Brunswick. We anticipate the need for brachytherapy services in Canada will significantly increase in the near future. In this review, we summarize brachytherapy programs across Canada, contemporary eligibility criteria for the procedure, toxicity and prostate-specific antigen recurrence free survival (PRFS), as published from Canadian institutions for both LDR and HDR brachytherapy. PMID:23671495

  3. Effect of tissue composition on dose distribution in brachytherapy with various photon emitting sources

    PubMed Central

    Ghorbani, Mahdi; Salahshour, Fateme; Haghparast, Abbas; Knaup, Courtney

    2014-01-01

    Purpose The aim of this study is to compare the dose in various soft tissues in brachytherapy with photon emitting sources. Material and methods 103Pd, 125I, 169Yb, 192Ir brachytherapy sources were simulated with MCNPX Monte Carlo code, and their dose rate constant and radial dose function were compared with the published data. A spherical phantom with 50 cm radius was simulated and the dose at various radial distances in adipose tissue, breast tissue, 4-component soft tissue, brain (grey/white matter), muscle (skeletal), lung tissue, blood (whole), 9-component soft tissue, and water were calculated. The absolute dose and relative dose difference with respect to 9-component soft tissue was obtained for various materials, sources, and distances. Results There was good agreement between the dosimetric parameters of the sources and the published data. Adipose tissue, breast tissue, 4-component soft tissue, and water showed the greatest difference in dose relative to the dose to the 9-component soft tissue. The other soft tissues showed lower dose differences. The dose difference was also higher for 103Pd source than for 125I, 169Yb, and 192Ir sources. Furthermore, greater distances from the source had higher relative dose differences and the effect can be justified due to the change in photon spectrum (softening or hardening) as photons traverse the phantom material. Conclusions The ignorance of soft tissue characteristics (density, composition, etc.) by treatment planning systems incorporates a significant error in dose delivery to the patient in brachytherapy with photon sources. The error depends on the type of soft tissue, brachytherapy source, as well as the distance from the source. PMID:24790623

  4. Direct interaction between the catalytic subunit of the calmodulin-sensitive adenylate cyclase from bovine brain with /sup 125/I-labeled wheat germ agglutinin and /sup 125/I-labeled calmodulin

    SciTech Connect

    Minocherhomjee, A.M.; Selfe, S.; Flowers, N.J.; Storm, D.R.

    1987-07-14

    A calmodulin-sensitive adenylate cyclase has been purified to apparent homogeneity from bovine cerebral cortex using calmodulin-Sepharose followed by forskolin-Sepharose and wheat germ agglutinin-Sepharose. The final product appeared as one major polypeptide of approximately 135,000 daltons on sodium dodecyl sulfate-polyacrylamide gels. This polypeptide was a major component of the protein purified through calmodulin-Sepharose. The catalytic subunit was stimulated 3-4-fold by calmodulin (CaM) with a turnover number greater than 1000 min/sup -1/ and was directly inhibited by adenosine. The catalytic subunit of the enzyme interacted directly with /sup 125/I-CaM on a sodium dodecyl sulfate-polyacrylamide gel overlay system, and this interaction was Ca/sup 2 +/ concentration dependent. In addition, the catalytic subunit was shown to directly bind /sup 125/I-labeled wheat germ agglutinin using a sodium dodecyl sulfate-polyacrylamide gel overlay technique, and N-acetylglucosamine inhibited binding of the lectin to the catalytic subunit. Calmodulin did not inhibit binding of wheat germ agglutinin to the catalytic subunit, and the binding of calmodulin was unaffected by wheat germ agglutinin. These data illustrate that the catalytic subunit of the calmodulin-sensitive adenylate cyclase is a glycoprotein which interacts directly with calmodulin and that adenosine can inhibit the enzyme without intervening receptors or G coupling proteins. It is concluded that the catalytic subunit of adenylate cyclase is a transmembrane protein with a domain accessible from the outer surface of the cell.

  5. delta 9-(16 alpha-/sup 125/I)iodo-19-nortestosterone: a gamma-emitting photoaffinity label for the progesterone receptor

    SciTech Connect

    Lamb, D.J.; Bullock, D.W.; Hoyte, R.M.; Hochberg, R.B.

    1988-05-01

    We have synthesized 16 alpha-iodo-4,9-estradien-17 beta-ol-3-one (delta 9-16 alpha-iodo-19-nortestosterone (delta 9-INT)) labeled with 125I (delta 9-(16 alpha-125I)INT) to provide a new gamma-emitting photoaffinity ligand for the progesterone receptor that has many advantages over the currently available (3H)R5020. We have characterized the interaction of delta 9-(16 alpha-125I)INT with the rabbit uterine progesterone receptor and have demonstrated the usefulness of this compound for studies of receptor structure. The binding of 2 nM (3H)progesterone to receptor in rabbit uterine cytosol was specifically competed for by 19-nortestosterone, 16 alpha-iodo-19-nortestosterone, and delta 9-INT. Scatchard analysis demonstrated that delta 9-(16 alpha-125I)INT and (3H)progesterone estimated the same number of binding sites in rabbit uterine cytosol, with a Kd for delta 9-(16 alpha-125I)INT of about 2.7 nM. The binding of delta 9-(16 alpha-125I)INT was inhibited by both progesterone and R5020, whereas testosterone, estradiol, and 5 alpha-dihydrotestosterone were ineffective. In cytosol, delta 9-(16 alpha-125I)INT covalently labeled the same mol wt receptor forms as (3H)R5020. Although the efficiency of cross-linking was similar for (3H)R5020 (3%) and delta 9-(16 alpha-125I)INT (4%), the radioactivity was 10-fold greater due to the higher specific activity of delta 9-(16 alpha-125I)INT and the lack of sample quench. The use of delta 9-(16 alpha-125I)INT greatly increases the sensitivity and efficiency of the photoaffinity labeling technique; it will provide a valuable tool for further studies of the progesterone receptor, allowing the detection of receptor in dilute cytosol after gel electrophoresis under denaturing conditions.

  6. Accelerated partial breast irradiation utilizing brachytherapy: patient selection and workflow.

    PubMed

    Shah, Chirag; Wobb, Jessica; Manyam, Bindu; Khan, Atif; Vicini, Frank

    2016-02-01

    Accelerated partial breast irradiation (APBI) represents an evolving technique that is a standard of care option in appropriately selected woman following breast conserving surgery. While multiple techniques now exist to deliver APBI, interstitial brachytherapy represents the technique used in several randomized trials (National Institute of Oncology, GEC-ESTRO). More recently, many centers have adopted applicator-based brachytherapy to deliver APBI due to the technical complexities of interstitial brachytherapy. The purpose of this article is to review methods to evaluate and select patients for APBI, as well as to define potential workflow mechanisms that allow for the safe and effective delivery of APBI. Multiple consensus statements have been developed to guide clinicians on determining appropriate candidates for APBI. However, recent studies have demonstrated that these guidelines fail to stratify patients according to the risk of local recurrence, and updated guidelines are expected in the years to come. Critical elements of workflow to ensure safe and effective delivery of APBI include a multidisciplinary approach and evaluation, optimization of target coverage and adherence to normal tissue guideline constraints, and proper quality assurance methods. PMID:26985202

  7. Accelerated partial breast irradiation utilizing brachytherapy: patient selection and workflow

    PubMed Central

    Wobb, Jessica; Manyam, Bindu; Khan, Atif; Vicini, Frank

    2016-01-01

    Accelerated partial breast irradiation (APBI) represents an evolving technique that is a standard of care option in appropriately selected woman following breast conserving surgery. While multiple techniques now exist to deliver APBI, interstitial brachytherapy represents the technique used in several randomized trials (National Institute of Oncology, GEC-ESTRO). More recently, many centers have adopted applicator-based brachytherapy to deliver APBI due to the technical complexities of interstitial brachytherapy. The purpose of this article is to review methods to evaluate and select patients for APBI, as well as to define potential workflow mechanisms that allow for the safe and effective delivery of APBI. Multiple consensus statements have been developed to guide clinicians on determining appropriate candidates for APBI. However, recent studies have demonstrated that these guidelines fail to stratify patients according to the risk of local recurrence, and updated guidelines are expected in the years to come. Critical elements of workflow to ensure safe and effective delivery of APBI include a multidisciplinary approach and evaluation, optimization of target coverage and adherence to normal tissue guideline constraints, and proper quality assurance methods. PMID:26985202

  8. Dexamethasone effects on (/sup 125/I)albumin distribution in experimental RG-2 gliomas and adjacent brain

    SciTech Connect

    Nakagawa, H.; Groothuis, D.R.; Owens, E.S.; Fenstermacher, J.D.; Patlak, C.S.; Blasberg, R.G.

    1987-12-01

    A total of 72 RG-2 transplanted gliomas were studied in 58 rats at three time points (1, 30, 240 min) after intravenous injection of (/sup 125/I)radioiodinated serum albumin ((/sup 125/I)RISA). The animals were divided into two groups: a control group that received no treatment and a second group that was treated with five doses of 1.5 mg/kg of dexamethasone over 2.5 days. Local tissue concentrations of (/sup 125/I)RISA were measured with quantitative autoradiography based on morphological features of the tumors and used to calculate the tissue distribution space. Two models were used to analyze the data. A two compartment model yielded estimates of local blood-to-tissue influx constants (K1), lower limit extracellular volumes (Ve), and plasma vascular volumes (Vp) in different tumor regions. Treatment with dexamethasone consistently reduced the RISA distribution space in the RG-2 tumors; the reduction in Ve was statistically significant in almost all tumor regions: whole tumor Ve (mean +/- SE) was reduced from 0.14 +/- 0.02 ml g-1 in control animals to 0.08 +/- 0.01 ml g-1 in dexamethasone treated animals. K1 and Vp were also decreased in all tumor regions after treatment with dexamethasone (whole tumor K1 decreased from 2.36 +/- 0.89 to 0.83 +/- 0.29 microliter g-1 min-1 and Vp decreased slightly from 0.016 +/- 0.013 to 0.010 +/- 0.005 ml g-1 after dexamethasone treatment), but these changes were not statistically significant. A comparison of the tumor influx constants in control animals and the aqueous diffusion constants of two different size molecules (RISA and aminoisobutyric acid) suggests that the ''pores'' across RG-2 capillaries are large and may not restrict the free diffusion of RISA (estimated minimum pore diameter greater than 36 nm) and that the total pore area is approximately 6.2 X 10(-5) cm2 g-1 in RG-2 tumor tissue.

  9. [Safety in brachytherapy].

    PubMed

    Marcié, S; Marinello, G; Peiffert, D; Lartigau, É

    2013-04-01

    No technique can now be used without previously considering the safety of patients, staff and public and risk management. This is the case for brachytherapy. The various aspects of brachytherapy are discussed for both the patient and the staff. For all, the risks must be minimized while achieving a treatment of quality. It is therefore necessary to establish a list as comprehensive as possible regardless of the type of brachytherapy (low, high, pulsed dose-rate). Then, their importance must be assessed with the help of their criticality. Radiation protection of personnel and public must take into account the many existing regulation texts. Four axes have been defined for the risk management for patients: organization, preparation, planning and implementation of treatment. For each axis, a review of risks is presented, as well as administrative, technical and medical dispositions for staff and the public. PMID:23465784

  10. Preferential reduction of binding of sup 125 I-iodopindolol to beta-1 adrenoceptors in the amygdala of rat after antidepressant treatments

    SciTech Connect

    Ordway, G.A.; Gambarana, C.; Tejani-Butt, S.M.; Areso, P.; Hauptmann, M.; Frazer, A. )

    1991-05-01

    This study utilized quantitative receptor autoradiography to examine the effects of repeated administration of antidepressants to rats on the binding of the beta adrenoceptor antagonist, {sup 125}I-iodopindolol ({sup 125}I-IPIN) to either beta-1 or beta-2 adrenoceptors in various regions of brain. Antidepressants were selected to represent various chemical and pharmacological classes including tricyclic compounds (desipramine and protriptyline), monoamine oxidase inhibitors (clorgyline, phenelzine and tranylcypromine), atypical antidepressants (mianserin and trazodone) and selective inhibitors of the uptake of serotonin (citalopram and sertraline). Additionally, rats were treated with various psychotropic drugs that lack antidepressant efficacy (cocaine, deprenyl, diazepam and haloperidol). Repeated treatment of rats with desipramine, protriptyline, clorgyline, phenelzine, tranylcypromine or mianserin reduced the binding of {sup 125}I-IPIN to beta-1 adrenoceptors in many brain areas. Only in the basolateral and lateral nuclei of the amygdala did all six of these antidepressants significantly reduce {sup 125}I-IPIN binding to beta-1 adrenoceptors. In these amygdaloid nuclei, the magnitude of the reduction in the binding of {sup 125}I-IPIN caused by each of these drugs was comparable to or greater than the reduction in binding produced in any other region of brain. Reductions of binding of {sup 125}I-IPIN after antidepressant treatments were not consistently observed in the cortex, the area of brain examined most often in homogenate binding studies. Only the monoamine oxidase inhibitors caused reductions in the binding of {sup 125}I-IPIN to beta-2 adrenoceptors, and this effect was generally localized to the amygdala and hypothalamus.

  11. Preliminary Characterization and In Vivo Studies of Structurally Identical (18)F- and (125)I-Labeled Benzyloxybenzenes for PET/SPECT Imaging of β-Amyloid Plaques.

    PubMed

    Yang, Yanping; Zhang, Xiaoyang; Cui, Mengchao; Zhang, Jinming; Guo, Zhide; Li, Yesen; Zhang, Xianzhong; Dai, Jiapei; Liu, Boli

    2015-01-01

    With the assistance of molecular docking and 3D-QSAR models established previously, structurally identical (18)F- and (125)I-labeled benzyloxybenzene derivatives were designed to achieve the early detection of Aβ plaques by PET/SPECT imaging. In competition binding assay, ligands 7a and 12a displayed high binding affinities to Aβ42 aggregates with Ki values of 19.5 nM and 23.9 nM, respectively. Specific plaque labeling was observed on the in vitro autoradiography of brain sections from AD patients and Tg mice. In biodistribution, [(125)I]7a, [(18)F]7a, [(125)I]12a and [(18)F]12a all exhibited high initial brain uptakes (>5% ID/g at 2 min). [(125)I]7a and [(125)I]12a cleared fast from the normal brain regions, while corresponding [(18)F]7a and [(18)F]12a showed slow washout rates. Dynamic microPET/CT and microSPECT/CT imaging data in normal ICR mice were in accordance with in vivo biodistribution results. In vivo metabolism results indicated that the different clearance profiles between the structurally identical (18)F- and (125)I-labeled tracers could be attributed to different biochemical characteristics of the radiometabolites. Radioiodinated benzyloxybenzene derivatives exhibited good in vivo biostability in brain. Ex vivo autoradiography further confirmed the strong in vivo Aβ labeling ability of [(125)I]7a. These new fluorinated and iodinated benzyloxybenzenes can develop into PET/SPECT dual imaging agents targeting Aβ plaques. PMID:26170205

  12. Reversible and irreversible labeling and autoradiographic localization of the cerebral histamine H2 receptor using ( sup 125 I)iodinated probes

    SciTech Connect

    Ruat, M.; Traiffort, E.; Bouthenet, M.L.; Schwartz, J.C.; Hirschfeld, J.; Buschauer, A.; Schunack, W. )

    1990-03-01

    Iodoaminopotentidine (I-APT)--i.e., N-(2-(4-amino-3-iodobenzamido)ethyl)-N'-cyano-N''-(3-(3- (1-piperidinylmethyl)phenoxy)propyl)guanidine--represents one of the most potent H2-receptor antagonists known so far. In membranes of guinea pig brain 125I-APT bound reversibly, selectively, and with high affinity (Kd = 0.3 nM) to a homogeneous population of sites unambiguously identified as H2 receptors by inhibition studies conducted with a large panel of antagonists. 125I-APT binding was also inhibited by histamine, and the effect was modulated by a guanyl nucleotide, which is consistent with the association of the H2 receptor with a guanine nucleotide binding regulatory protein. The low nonspecific binding of 125I-APT generated high contrast autoradiographic pictures in brain sections and established the precise distribution of H2 receptors. Their highly heterogeneous distribution and laminated pattern in some areas suggest their major association with neuronal elements. These localizations were more consistent than those of H1 receptors with the distribution of histaminergic projections, indicating that H2 receptors mediate a larger number of postsynaptic actions of histamine--e.g., in striatum. Colocalizations of H1 and H2 receptors in some areas account for their known synergistic interactions in cAMP formation induced by histamine. The distribution of 125I-APT binding sites did not strictly parallel that of the H2-receptor-linked adenylate cyclase activity, which may reflect heterogeneity among H2 receptors. After UV irradiation and SDS/PAGE analysis, (125I)iodoazidopotentidine (125I-AZPT), a photoaffinity probe derived from 125I-APT, was covalently incorporated in several peptides, among which the labeling of two peptides of 59 and 32 kDa was prevented by H2 antagonists, suggesting that they correspond to H2-receptor binding peptides or proteolysis products of the latter.

  13. Inhibition of sup 125 I organification and thyroid hormone release by interleukin-1, tumor necrosis factor-alpha, and interferon-gamma in human thyrocytes in suspension culture

    SciTech Connect

    Sato, K.; Satoh, T.; Shizume, K.; Ozawa, M.; Han, D.C.; Imamura, H.; Tsushima, T.; Demura, H.; Kanaji, Y.; Ito, Y. )

    1990-06-01

    To elucidate the mechanism of decreased 131I uptake by the thyroid gland in patients with subacute thyroiditis and painless thyroiditis, human thyroid follicles were cultured with interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF alpha), and/or interferon-gamma (IFN gamma), and the effects of these cytokines on thyroid function were studied in vitro. When human thyrocytes were cultured in RPMI-1640 medium containing 0.5% fetal calf serum and TSH for 5-8 days, the cells incorporated 125I, synthesized de novo (125I)iodotyrosines and (125I)iodothyronines, and secreted (125I)T4 and (125I)T3 into the medium. IL-1 alpha and IL-1 beta inhibited 125I incorporation and (125I)iodothyronine release in a concentration-dependent manner. The minimal inhibitory effect was detected at 10 pg/ml. Electron microscopic examination revealed a marked decrease in lysosome formation in IL-1-treated thyrocytes. TNF alpha and IFN gamma also inhibited thyroid function in a concentration-dependent manner. Furthermore, when thyrocytes were cultured with IL-1, TNF alpha and IFN gamma, these cytokines more than additively inhibited thyroid function. Although the main mechanism of 131I uptake suppression in the thyroid gland in subacute thyroiditis is due to cellular damage and suppression of TSH release, our present findings suggest that IL-1, TNF alpha, and IFN gamma produced in the inflammatory process within the thyroid gland further inhibit iodine incorporation and at least partly account for the decreased 131I uptake by the thyroid gland in destruction-induced hyperthyroidism.

  14. Purification and characterization of (-)(/sup 125/I)hydroxyphenylisopropyladenosine, an adenosine R-site agonist radioligand and theoretical analysis of mixed stereoisomer radioligand binding

    SciTech Connect

    Linden, J.

    1984-11-01

    (-)-N6-(R-4-Hydroxyphenylisopropyl)adenosine (HPIA) was iodinated with NaI and trace /sup 125/I. Mono- and diiodinated reaction products and the starting material were separated by high pressure liquid chromatography and the structures of the reaction products were verified by NMR. (-)-N6-(R-Phenylisopropyl)adenosine (PIA), IHPIA, and I2HPIA decreased rat atrial contractility with ED50 values of 24, 28, and 33 nM, respectively. The contractile effects of these compounds were competitively blocked by theophylline (KI . 7.9 microM), but were not affected by adenosine deaminase. IHPIA also inhibited (-)isoproterenol-stimulated cyclic AMP accumulation in adipocytes with an ED50 (10 nM) and to an extent (83%) nearly identical to PIA. (/sup 125/I)HPIA prepared using carrier-free /sup 125/I bound to adenosine receptors on membranes from rat cerebral cortex, adipocyte ghosts, and heart ventricles. Binding was inhibited stereospecifically by PIA and by other adenosine analogues and alkylxanthines. The KD of (/sup 125/I)HPIA determined kinetically using brain membranes at 21 degrees was 0.94 nM in good agreement with the equilibrium determination of 1.94 nM. The density of adenosine receptors in brain membranes was found to be 871 fmol/mg of protein. When normalized to protein, the density of receptors in heart membranes and adipocyte ghosts, respectively, was found to be 39- and 2.3-fold less than in brain membranes. It was concluded that (/sup 125/I)HPIA can be rapidly synthesized and purified, binds to adenosine R-sites and is an agonist radioligand resistant to adenosine deaminase. Computer modeling of the equilibrium binding resulting from the use of mixed stereoisomers of a radioligand indicates that the combined use of (-)(/sup 125/I)HPIA and (+)(/sup 125/I)HPIA would result in the generation of nonlinear Scatchard plots.

  15. The use of a high-purity germanium detector for routine measurements of {sup 125}I in radiation workers

    SciTech Connect

    Kopp, P.; Bergmann, H.; Havlik, E.; Aiginger, H.; Unfried, E.; Riedlmayer, L.

    1994-12-01

    A high-purity germanium detector was calibrated for the assessment of {sup 125}I uptake in the thyroid gland of radiation workers. A cylindrical water phantom (perspex walls) with high flexibility for position and size of the thyroid was constructed. Within a massive shielding chamber built for a whole-body counter, an activity of 2.2 Bq was detectable (MDA). This is well below the very restrictive limiting value of 20 Bq for inhalation specified by Austrian law. An activity of 128 Bq was measured with a statistical uncertainty of 5% in a counting period of 10 min. Various parameters influencing the result are investigated as well as the performance of two other measurement geometries outside the shielding chamber. 13 refs., 4 figs., 2 tabs.

  16. The fate of (125I)iodoepidermal growth factor in isolated hepatocytes: a quantitative electron microscopic autoradiographic study

    SciTech Connect

    Carpentier, J.L.; Gorden, P.; Freychet, P.; Canivet, B.; Orci, L.

    1981-09-01

    When (125I)iodoepidermal growth factor is incubated with freshly isolated rat hepatocytes, cell-associated radioactivity reaches apparent steady state by 60 min at 20 C and by 30 min of incubation at 37 C. When the distribution of cell-associated radioactivity is studied at different times of incubation by quantitative electron microscopic autoradiography, the ligand initially associates with the plasma membrane and is progressively internalized as a function of time. The internalized ligand preferentially associates with lysosome-like structures. Qualitatively, these events are similar to those previously obtained with labeled insulin and glucagon in this cell, but quantitatively, the internalization of epidermal growth factor is much greater. The data suggest that the ligand or its specific receptor rather than the cell type is the major determinant of the rate of internalization.

  17. Schizophrenia: elevation of dopamine D4-like sites, using [3H]nemonapride and [125I]epidepride.

    PubMed

    Seeman, P; Guan, H C; Van Tol, H H

    1995-11-14

    We here report a three-fold elevation of dopamine D4-like sites in schizophrenia, using [3H]nemonapride to measure dopamine D2 and D3 receptors and D4-like sites, and using [125I]epidepride to measure D2 and D3 sites in ten control and nine schizophrenia post-mortem brain putamen tissues. This result differs from a recent report which did not detect significant D4-like sites in control or schizophrenia putamen (Reynolds and Mason, 1995, Eur. J. Pharmacol. 281, R5). The present finding agrees with other reports wherein an elevation in D4-like sites was found in schizophrenia, using [3H]nemonapride for D2, D3 and D4-like sites, but [3H]raclopride for D2 and D3 sites. The nature of these D4-like sites is not known. PMID:8605946

  18. The in vitro selective concentration of an /sup 125/I-iodinated compound in human tumor cells

    SciTech Connect

    Carpenter, R.N.; Brown, I.; Chir, B.; Mitchell, J.S.

    1983-01-01

    Uptake studies of the potential endoradiotherapeutic agent, 6-/sup 125/I-iodo-2-methyl-1,4-naphthoquinol bis(diammonium phosphate) have been carried out in vitro on a wide range of normal and malignant human cells. In general, for a standardized dose of 0.1 ..mu..Ci/ml, the uptake of the compound into normal cells was 0.0015-0.135 pCi/cell. Uptake into malignant cells was significantly higher than normal cells; uptakes of 0.89-11.3 pCi/cell were noted for melanoma, teratoma of testis, osteosarcoma and adenocarcinoma of colon and pancreas. Comparative uptake ratios for melanoma:Chang liver cells and testicular teratoma:normal testis were 29 and 23, respectively. Larger uptake ratios are usually observed with higher doses.

  19. Long-term controlled release of 125I-tagged BMP-2 by mesoporous bioactive glass with ordered nanopores

    PubMed Central

    ZHANG, QUAN; ZHANG, YE; CHEN, WENJUN; ZHANG, BINGWEN; WANG, SHILONG

    2013-01-01

    The aim of this study was to investigate the ability of mesoporous bioactive glass with ordered nanopores (80S MBG) to adsorb and provide the delayed release of 125I-tagged bone morphogenetic protein-2 (BMP-2). A 50 mg piece of 80S MBG was produced, which comprised SiO2, CaO and P2O5 in a component molar ratio of 80:15:5. Each MBG piece adsorbed 30 μg 125I-BMP-2. Persistent radioactivity in the MBG was periodically measured in simulated body fluid. The total amount of BMP-2 released and the mean amount released per day were calculated. A delayed release curve of BMP-2 was constructed. SPSS 15.0 software was used to perform a statistical analysis. The amount of BMP-2 released in the first two days was one-quarter of the total load. A line equation, y = 490.55×1/2 + 7268.82, was obtained from the square root of protein release doses value at 3–94 days. The total amount of BMP-2 released over 94 days was 11.894 μg, which was ~39.6% of the total load. The half-life of the release time was 248 days. From the second week, the rate of BMP release had stabilized to a mean of 37.42±18.67 ng/day and the difference of the mean amount released per day had no statistical significance (P>0.05). High adsorption and delayed release effects of BMP-2 were observed in 80S MBG. The delayed release conforms to the Higuchi equation, which indicates possible applications in promoting bone healing. PMID:24250724

  20. p-( sup 125 I)iodoclonidine, a novel radiolabeled agonist for studying central alpha 2-adrenergic receptors

    SciTech Connect

    Baron, B.M.; Siegel, B.W. )

    1990-09-01

    Unlabeled p-iodoclonidine was efficacious in attenuating forskolin-stimulated cAMP accumulation in SK-N-SH neuroblastoma cells. Maximal attenuation was 76 +/- 3%, with an EC50 of 347 +/- 60 nM. Comparable values of epinephrine were 72 +/- 3% and 122 +/- 22 nM. Responses to both agonists were abolished by 10 microM phentolamine. Therefore, p-iodoclonidine is an agonist in a cell culture model system of the neuronal alpha 2-adrenergic receptor. p-(125I)Iodoclonidine binding to membranes were measured using various regions of the rat brain. The agonist labeled a single population of sites present on cerebral cortical membranes, which was saturable (Bmax = 230 fmol/mg of protein) and possessed high affinity for the ligand (Kd = 0.6 nM). Binding was largely specific (93% at 0.6 nM). A variety of alpha 2-adrenergic agonists and antagonists were shown to compete for the binding of the radioligand. The binding of p-(125I)iodoclonidine was much less sensitive to agents that interact with alpha 1-adrenergic, serotonergic, and dopaminergic receptors. Approximately 65% of the binding was sensitive to guanine nucleotides. Association kinetics using 0.4 nM radioligand were biphasic (37% associate rapidly, with kobs = 0.96 min-1, with the remainder binding more slowly, with kobs = 0.031 min-1) and reached a plateau by 90 min at 25 degrees. Dissociation kinetics were also biphasic, with 30% of the binding dissociating rapidly (k1 = 0.32 min-1) and the remainder dissociating 50-fold more slowly (k2 = 0.006 min-1). Agonist binding is, therefore, uniquely complex and probably reflects the conformational changes that accompany receptor activation.

  1. Effect of photon energy spectrum on dosimetric parameters of brachytherapy sources

    PubMed Central

    Ghorbani, Mahdi; Davenport, David

    2016-01-01

    Abstract Aim The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters. Background Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources. Materials and methods MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources. Air kerma strength per activity, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated and isodose curves were plotted for three different photon energy spectra. The references for photon energy spectra were: published papers, Lawrence Berkeley National Laboratory (LBNL), and National Nuclear Data Center (NNDC). The data calculated by these photon energy spectra were compared. Results Dose rate constant values showed a maximum difference of 24.07% for 103Pd source with different photon energy spectra. Radial dose function values based on different spectra were relatively the same. 2D anisotropy function values showed minor differences in most of distances and angles. There was not any detectable difference between the isodose contours. Conclusions Dosimetric parameters obtained with different photon spectra were relatively the same, however it is suggested that more accurate and updated photon energy spectra be used in Monte Carlo simulations. This would allow for calculation of reliable dosimetric data for source modeling and calculation in brachytherapy treatment planning systems. PMID:27247558

  2. In Vivo Dosimetry With a Linear MOSFET Array to Evaluate the Urethra Dose During Permanent Implant Brachytherapy Using Iodine-125

    SciTech Connect

    Bloemen-van Gurp, Esther J.; Haanstra, Bjoerk K.C.; Murrer, Lars H.P.; Gils, Francis C.J.M. van; Dekker, Andre L.A.J.; Mijnheer, Ben J.; Lambin, Philippe

    2009-11-15

    Purpose: To develop a technique to monitor the dose rate in the urethra during permanent implant brachytherapy using a linear MOSFET array, with sufficient accuracy and without significantly extending the implantation time. Methods and Materials: Phantom measurements were performed to determine the optimal conditions for clinical measurements. In vivo measurements were performed in 5 patients during the {sup 125}I brachytherapy implant procedure. To evaluate if the urethra dose obtained in the operating room with the ultrasound transducer in the rectum and the patient in treatment position is a reference for the total accumulated dose; additional measurements were performed after the implantation procedure, in the recovery room. Results: In vivo measurements during and after the implantation procedure agree very well, illustrating that the ultrasound transducer in the rectum and patient positioning do not influence the measured dose in the urethra. In vivo dose values obtained during the implantation are therefore representative for the total accumulated dose in the urethra. In 5 patients, the dose rates during and after the implantation were below the maximum dose rate of the urethra, using the planned seed distribution. Conclusion: In vivo dosimetry during the implantation, using a MOSFET array, is a feasible technique to evaluate the dose in the urethra during the implantation of {sup 125}I seeds for prostate brachytherapy.

  3. Differentiation of 5-hydroxytryptamine2 receptor subtypes using sup 125 I-R-(-)2,5-dimethoxy-4-iodo-phenylisopropylamine and sup 3 H-ketanserin

    SciTech Connect

    McKenna, D.J.; Peroutka, S.J. )

    1989-10-01

    The radioligand binding characteristics of 125I-R-(-)4-iodo-2,5-dimethoxyphenylisopropylamine (125I-R-(-)DOI) and 3H-ketanserin were compared in rat and bovine cortical membranes. In rat cortex, 125I-R-(-)DOI labels a relatively low density of binding sites (Bmax = 2.5 +/- 0.2 pmol/gm tissue) with high affinity (KD = 0.63 +/- 0.09 nM). In bovine cortex, specific binding of 125I-R-(-)DOI represents less than 20% of total binding at radioligand concentrations above 0.6 nM, and, therefore, the data cannot be analyzed adequately by Scatchard transformation. By contrast, 3H-ketanserin displays saturable, specific high-affinity binding in both rat cortex (KD = 1.0 +/- 0.1 nM; Bmax = 11 +/- 0.4 pmol/gm tissue) and bovine cortex (KD = 1.2 +/- 0.2 nM; Bmax = 5.3 +/- 0.4 pmol/gm tissue). Ki values for 30 drugs were determined for 125I-R-(-)DOI-labeled sites in rat cortex and 3H-ketanserin-labeled sites in bovine cortex. 5-Hydroxytryptamine (5-HT) displays 250-fold higher selectivity for the 125I-R-(-)DOI-labeled sites (Ki = 3.0 +/- 0.7 nM) than for the 3H-ketanserin-labeled sites (Ki = 750 +/- 50 nM). Structural congeners of R-(-)DOI display 80- to 160-fold higher affinity for the 125I-R-(-)DOI binding site than for the 3H-ketanserin-labeled binding site. d-LSD and putative 5-HT2 antagonists are approximately equipotent at both sites. Significant correlations were found between drug affinities for 125I-R-(-)DOI-labeled sites in rat cortex and putative 5-HT2A sites labeled previously by 77Br-R-(-)DOB (r = 0.93, p less than 0.01), putative 5-HT2B sites labeled by 3H-ketanserin in bovine cortex (r = 0.63, p less than 0.01), and 5-HT1C binding sites that have been characterized by other investigators (r = 0.78, p less than 0.01). No significant correlations were found between drug affinities for 125I-R-(-)DOI-labeled sites in rat cortex and 5-HT1A, 5-HT1B, 5-HT1D, or 5-HT3 sites, as determined by previous investigators.

  4. Synthesis and evaluation of an (125)I-labeled azide prosthetic group for efficient and bioorthogonal radiolabeling of cyclooctyne-group containing molecules using copper-free click reaction.

    PubMed

    Choi, Mi Hee; Shim, Ha Eun; Nam, You Ree; Kim, Hye Rim; Kang, Jung Ae; Lee, Dong-Eun; Park, Sang Hyun; Choi, Dae Seong; Jang, Beom-Su; Jeon, Jongho

    2016-02-01

    Herein we report the radiosynthesis of a pyridine derived azide prosthetic group for iodine radioisotope labeling of dibenzocyclooctyne (DBCO) conjugated molecules. The radiolabeling of the stannylated precursor 2 was conducted using [(125)I]NaI and chloramine-T to give (125)I-labeled azide ([(125)I]1) with high radiochemical yield (72±8%, n=4) and radiochemical purity (>99%). Using (125)I-labeled azide ([(125)I]1), cyclic RGD peptide and near infrared fluorescent molecule were efficiently labeled with modest to good radiochemical yields. The biodistribution study and SPECT/CT images showed that [(125)I]1 underwent rapid renal clearance. These results clearly demonstrated that [(125)I]1 could be used as an useful radiotracer for in vivo pre-targeted imaging as well as efficient in vitro radiolabeling of DBCO containing molecules. PMID:26748695

  5. Measurement of cyclosporine concentrations in whole blood: HPLC and radioimmunoassay with a specific monoclonal antibody and /sup 3/H- or /sup 125/I-labeled ligand compared

    SciTech Connect

    Wolf, B.A.; Daft, M.C.; Koenig, J.W.; Flye, M.W.; Turk, J.W.; Scott, M.G.

    1989-01-01

    We compared cyclosporine concentrations in whole blood as measured by HPLC and by RIA with a monoclonal antibody specific for cyclosporine with /sup 3/H- or /sup 125/I-labeled cyclosporine ligand. The /sup 3/H-RIA kit slightly underestimated cyclosporine concentrations (greater than 600 micrograms/L) in comparison with HPLC. Over a wide range of concentrations, cyclosporine measured with the /sup 125/I-RIA kit correlated well with HPLC (slope = 0.99, n = 301, r = 0.98), observed for samples from recipients of kidney, heart, or liver allografts (respective slopes: 1.01, 0.93, and 1.00). The /sup 125/I-RIA standard curve was linear to 1000 micrograms of cyclosporine per liter. Inter- and intra-assay CVs for /sup 125/I-RIA measurements of cyclosporine were less than or equal to 7%. Evidently, the /sup 125/I-RIA kit involving a monoclonal antibody specific for cyclosporine is equivalent to the HPLC assay and can replace it for therapeutic drug monitoring of cyclosporine therapy.

  6. In vitro binding properties and autoradiographic imaging of 3-iodobenzamide ((/sup 125/I)-IBZM): a potential imaging ligand for D-2 dopamine receptors in SPECT

    SciTech Connect

    Bruecke, T.; Tsai, Y.F.; McLellan, C.; Singhanyom, W.; Kung, H.F.; Cohen, R.M.; Chiueh, C.C.

    1988-01-01

    The in vitro binding properties of the (/sup 125/I) labeled benzamide, (S(-)-N-((1-ethyl-2-pyrrolidinyl)-methyl)-2-hydroxy-3-iodo-6-methoxy-benzamide, IBZM) were determined in bovine and mouse caudate membrane homogenates and by autoradiography of mouse brain slices. (/sup 125/I)-IBZM binding is saturable and reversible with B/sub max/ of 373 +/- 51 fmol/mg protein and a K/sub d/ of 3.1 +/- 0.62 nM and 0.56 nM as calculated by association and dissociation time constants. In competition experiments, K/sub i/ values for the D-2 antagonists YM-09151-2 and spiperone are 4 orders of magnitude lower than the K/sub i/ value for the D-1 antagonist SCH-23390 and S(-)-IBZM is ten-fold more potent than R(+)-IBZM. (/sup 125/I)-IBZM has a low affinity for serotonin S-2 and for alpha receptors. Therefore, it is a highly selective ligand for dopamine D-2 receptors. Autoradiographic images of brain sections incubated with (/sup 125/I)-IBZM show the dopamine D-2 receptors of the striatum, nucleus accumbens and olfactory tubercle with a high ratio of specific to nonspecific binding. Thus, S(-)-IBZM, when labeled with (/sup 125/I), may be useful for in vivo imaging of dopamine D-2 receptors by single photon emission computerized tomography (SPECT).

  7. The labelling of proteins to high specific radioactivities by conjugation to a 125I-containing acylating agent. Application to the radioimmunoassay

    PubMed Central

    Bolton, A. E.; Hunter, W. M.

    1973-01-01

    1. A new method is described for labelling proteins to high specific radioactivities with 125I. The protein is treated with a 125I-labelled acylating agent, iodinated 3-(4-hydroxyphenyl)propionic acid N-hydroxysuccinimide ester, which reacts with free amino groups in the protein molecule to attach the 125I-labelled groups by amide bonds. 2. Three protein hormones have been labelled by this method, human growth hormone, human thyroid-stimulating hormone and human luteinizing hormone. Specific radioactivities of up to 170, 120 and 55μCi/μg respectively have been obtained for these hormones. 3. The immunoreactivity of these labelled hormones has been investigated by using a radioimmunoassay system specific for each hormone. These preparations have also been compared with and found to be equal or superior to labelled hormones prepared by chemical substitution of 125I into tyrosine residues of the proteins by using the chloramine-t-oxidation procedure. 4. With some antisera the immunoreactivity of the antigen was diminished by the introduction of a single I atom into the tyrosyl groups, whereas antigen containing a single 125I-labelled 3-(4-hydroxyphenyl)propionamide group showed the same immunoreactivity as the unmodified antigen. PMID:4733239

  8. Formation of complexes between 125I-labelled human or bovine somatotropins and binding proteins in vivo in rat liver and kidney.

    PubMed Central

    Bonifacino, J S; Roguin, L P; Paladini, A C

    1983-01-01

    At 5 min after intravenous injection, both 125I-labelled human somatotropin and 125I-labelled bovine somatotropin were concentrated in rat liver and kidney. When the labelled hormones were administered along with an excess of the corresponding unlabelled hormone, a significant decrease of the uptake was observed in the liver, but not in the kidney. Study of the subcellular distribution of radioiodinated somatotropins in liver revealed that most of the radioactivity was specifically concentrated in the microsomal fraction. In contrast, the kidney fraction that accounted for most of the radioactivity was the 100 000 g supernatant. After solubilization, with 1% (w/v) Triton X-100, of the microsomal fractions obtained from both organs, the radioactive material was analysed by gel filtration on Sepharose CL-6B. By using this approach, it was demonstrated that both 125I-labelled human somatotropin and 125I-labelled bovine somatotropin bind in vivo to proteins present in liver. A small proportion of 125I-labelled human somatotropin was also shown to form complexes with proteins present in kidney. The present results demonstrate that the liver uptake is mainly due to binding of somatotropins to specific proteins, in contrast with the kidney, in which binding to specific sites contributes minimally to the overall uptake. PMID:6615460

  9. Restenosis: Intracoronary Brachytherapy.

    PubMed

    Drachman, Douglas E.; Simon, Daniel I.

    2002-04-01

    Though interventional strategies have revolutionized the management of patients with symptomatic coronary artery disease, in-stent restenosis has emerged as the single most important limitation of long-term success following percutaneous coronary intervention. Once present, in-stent restenosis is extraordinarily difficult to treat, with conventional revascularization techniques failing in 50% to 80% of patients. Intracoronary radiation, or brachytherapy, targets cellular proliferation within the culprit neointima. Clinical trials have demonstrated that brachytherapy is a highly effective treatment for in-stent restenosis, reducing angiographic restenosis by 50% to 60% and the need for target vessel revascularization by 40% to 50%. The benefits of intracoronary brachytherapy may be particularly pronounced in certain patient subgroups (eg, those with diabetes, long lesions, or lesions in saphenous vein bypass grafts), but comes at the cost of an increased rate of late stent thrombosis and the need for extended antiplatelet therapy. The role of brachytherapy in the arsenal of the interventional cardiologist will continue to evolve, particularly in light of the unprecedented recent advances with the use of drug-eluting stents for restenosis prevention. PMID:11858773

  10. Determination of the prescription dose for biradionuclide permanent prostate brachytherapy

    SciTech Connect

    Nuttens, V. E.; Lucas, S.

    2008-12-15

    A model based on the linear quadratic model that has been corrected for repopulation, sublethal cell damage repair, and RBE effect has been used to determine the prescription dose for prostate permanent brachytherapy using seeds loaded with a mixture of {sup 103}Pd and {sup 125}I or a mixture of {sup 103}Pd and {sup 131}Cs. The prescription dose was determined by comparing the tumor cell survival fractions between the considered biradionuclide seed implant and one monoradionuclide seed implant chosen from {sup 103}Pd, {sup 125}I, and {sup 131}Cs. Prostate edema is included in the model. The influence of the value of the radiobiological parameters and RBE were also investigated. Two mixtures of radionuclides were considered: {sup 103}Pd{sub 0.75}-{sup 125}I{sub 0.25} and {sup 103}Pd{sub 0.25}-{sup 131}Cs{sub 0.75}, where the subscripts indicate the fractions of total initial internal activity in the biradionuclide seed. These fractions were selected in order to obtain a dose distribution that lies between that of {sup 103}Pd and {sup 125}I/{sup 131}Cs. As expected, the computed prescription dose values are dependent on the model parameters (edema half-life and magnitude, radiobiogical parameters, and RBE). The radionuclide used as a benchmark also has a strong impact on the derived prescribed dose. The large uncertainties in the radiobiological parameters and RBE values produce big errors in the computed prescribed dose. Averaged over the range of all the parameters and depending on the radionuclide used as a benchmark (in subscript), the derived prescription dose for the first mixture (PdI) would be: D{sub Pd}{sup PdI}=142{sub -16}{sup +15} Gy and D{sub I}{sup PdI}=142{sub -8}{sup +6} Gy; and D{sub Pd}{sup PdCs}=128{sub -13}{sup +13} Gy and D{sub Cs}{sup PdCs}=115{sub -7}{sup +6} Gy for the PdCs mixture. The uncertainties could be reduced if the radiobiological parameters and RBE value were known more accurately. However, as edema characteristics are patient

  11. Detection by /sup 125/I-cationized cytochrome c of proteoglycans and glycosaminoglycans immobilized on unmodified and on positively charged nylon 66

    SciTech Connect

    Heimer, R.; Molinaro, L. Jr.; Sampson, P.M.

    1987-09-01

    We have examined the detection by a /sup 125/I-labeled basic protein, cationized cytochrome c, of selected proteoglycans (PGs) and standard preparations of glycosaminoglycans (GAGs) immobilized on Nylon 66 and also on positively charged Nylon 66. Immobilization on Nylon 66 appears to allow a relative freedom of interaction between PGs or GAGs and /sup 125/I-cationized cytochrome c, but a more restricted reaction was observed when PGs and GAGs were immobilized to positively charged Nylon 66. On this support PGs with large numbers of GAG side chains reacted well with /sup 125/I-cationized cytochrome c, but GAGs were minimally reactive. By taking advantage of some of the properties of large-pore agarose-acrylamide gels, rapid partial characterization of some PGs can be accomplished in the 10-ng range, and therefore at a sensitivity equal to PGs with internal biosynthetic labels.

  12. Direct demonstration of insulin receptor internalization. A quantitative electron microscopic study of covalently bound /sup 125/I-photoreactive insulin incubated with isolated hepatocytes

    SciTech Connect

    Gorden, P.; Carpentier, J.L.; Moule, M.L.; Yip, C.C.; Orci, L.

    1982-07-01

    When /sup 125/I-insulin is incubated with isolated rodent hepatocytes at 37 degrees C, the ligand initially binds to the plasma membrane of the cell and is subsequently internalized by adsorptive endocytosis. To confirm directly that the insulin receptor is internalized with the ligand, we covalently linked photoreactive /sup 125/I-N sigma B29 (azidobenzoyl) insulin to its specific hepatocyte receptor and followed its fate by quantitative electron microscopic autoradiography. We found that the covalently linked photoreactive insulin is internalized by the cell in fashion analogous to the internalization of ordinary /sup 125/I-insulin, indicating that, at least under these conditions, the insulin receptor is internalized with the ligand.

  13. Influence of photon energy spectra from brachytherapy sources on Monte Carlo simulations of kerma and dose rates in water and air

    SciTech Connect

    Rivard, Mark J.; Granero, Domingo; Perez-Calatayud, Jose; Ballester, Facundo

    2010-02-15

    Purpose: For a given radionuclide, there are several photon spectrum choices available to dosimetry investigators for simulating the radiation emissions from brachytherapy sources. This study examines the dosimetric influence of selecting the spectra for {sup 192}Ir, {sup 125}I, and {sup 103}Pd on the final estimations of kerma and dose. Methods: For {sup 192}Ir, {sup 125}I, and {sup 103}Pd, the authors considered from two to five published spectra. Spherical sources approximating common brachytherapy sources were assessed. Kerma and dose results from GEANT4, MCNP5, and PENELOPE-2008 were compared for water and air. The dosimetric influence of {sup 192}Ir, {sup 125}I, and {sup 103}Pd spectral choice was determined. Results: For the spectra considered, there were no statistically significant differences between kerma or dose results based on Monte Carlo code choice when using the same spectrum. Water-kerma differences of about 2%, 2%, and 0.7% were observed due to spectrum choice for {sup 192}Ir, {sup 125}I, and {sup 103}Pd, respectively (independent of radial distance), when accounting for photon yield per Bq. Similar differences were observed for air-kerma rate. However, their ratio (as used in the dose-rate constant) did not significantly change when the various photon spectra were selected because the differences compensated each other when dividing dose rate by air-kerma strength. Conclusions: Given the standardization of radionuclide data available from the National Nuclear Data Center (NNDC) and the rigorous infrastructure for performing and maintaining the data set evaluations, NNDC spectra are suggested for brachytherapy simulations in medical physics applications.

  14. Effect of glutamatergic systems on in vivo binding of [(125)I]beta-CIT in the brain of a rat model of Parkinson's disease.

    PubMed

    Kagawa, Shinya; Nakano, Takayuki; Inoue, Osamu; Nishimura, Tsunehiko

    2002-10-01

    The effect of MK-801, a noncompetitive NMDA receptor antagonist, on both in vivo and in vitro binding of [(125)I]beta-CIT (RTI-55) was investigated in a rat model of Parkinson's disease. The binding experiments were performed 2 weeks after unilateral intranigral microinjection of 6-hydroxydopamine (6-OHDA). In the in vitro binding study, no alterations in [(125)I]beta-CIT binding in rat brain sections were observed after addition of MK-801, 0.03 microM or 3 microM, to the incubation medium. However, in vivo [(125)I]beta-CIT binding to the dopamine transporter in both nonlesioned and 6-OHDA-lesioned striatum was significantly increased by pretreatment with MK-801. In vivo [(125)I]beta-CIT binding to the serotonin (5HT) transporter in nonlesioned cerebral cortex, hypothalamus, and thalamus was also significantly increased by MK-801. However, the degree of change in the specific binding of [(125)I]beta-CIT induced by MK-801 was smaller in the lesioned cerebral cortex. Kinetic analysis, by a simplified three-compartment model with the cerebellum as the reference region, revealed that these alterations in the in vivo [(125)I]beta-CIT binding induced by MK-801 were mainly due to changes in the rate constants of in vivo binding, the input rate constant, k(3), and the output rate constant, k(4). These results indicate that the glutamatergic system significantly affects the function of dopamine transporters in the degenerated dopaminergic neurons in Parkinson's disease. PMID:12211097

  15. Enhanced lysis of (/sup 125/I)5-iodo-2'-deoxyuridine-labeled target cells in the presence of normal macrophages: possible mechanisms of action

    SciTech Connect

    Evans, R.; Eidlen, D.M.

    1985-01-01

    The potential mechanisms involved during the faster release of (/sup 125/I)-iodo-2'-deoxyuridine (/sup 125/IdUrd)-labeled target sarcoma cells in the presence of normal C57BL/6J peritoneal macrophages were investigated. Maximum (. 90%) spontaneous release of /sup 125/I from target cells cultured alone occurred over a period of about 10 days. However, after about 3 days, confluent sheets of target cells developed. In the presence of normal macrophages, 90% of the /sup 125/I was released between 3 and 7 days, again with the formation of confluent sheets of target cells. This enhanced /sup 125/I release was not influenced by increasing the relative concentration of IdUrd using the nonradioactive isotope 127IdUrd. Established mechanisms of target cell destruction were investigated but no evidence was found for the involvement of superoxide anion, hydrogen peroxide, or regulation by prostaglandin synthesis. The macrophage-mediated effect was abrogated by incorporating hydrocortisone-acetate (10(-7) to 10(-4) M) into the culture medium but this did not affect target cell proliferation. The use of serum-free culture medium suggested that macrophages secreted a soluble mediator that was not derived from or dependent on the presence of fetal bovine serum. In addition, macrophage-conditioned medium was able to induce the faster /sup 125/I release. The failure to precipitate with 20% trichloroacetic acid the /sup 125/I released from target cells cultured in the presence of macrophages indicated that the radioactive component had been separated from the precipitable DNA. The data are discussed in light of two possible hypotheses: that macrophages recognized subtle changes in IdUrd-labeled cells and exacerbate radiotoxicity, and that the faster release reflected proliferative death caused by stimulated growth.

  16. Receptor-mediated endocytosis of insulin in lower vertebrates: internalization and intracellular processing of 125I-insulin in isolated hepatocytes of lamprey and frog.

    PubMed

    Lappova, Y L; Leibush, B N

    1995-10-01

    The binding of 125I-insulin to cellular insulin receptors and the internalization of insulin-receptor complexes have been studied in isolated hepatocytes of frog and lamprey. Two classes of binding sites (Kd 10(-9) and 10(-8) M) were found in cells of both species. The molecular weight of the insulin receptor alpha-subunit was 130 kDa in both species. Internalization of bound 125I-insulin in both species was found in the temperature range 0 to 20 degrees. Cells "loaded" with 125I-insulin were used to estimate the fate of the internalized ligand. Release of internalized ligand from frog cells increased at temperatures ranging from 0 to 20 degrees. At 0 degrees the degraded 125I-insulin was 5%, at 5 degrees 7%, and at 20 degrees 17% of total radioactivity accumulated in the medium. In lamprey hepatocytes there was neither radioactivity accumulation in the incubation medium nor release from cells at all temperatures studied. The intracellular degradation of internalized 125I-insulin in frog hepatocytes was much lower than that in lamprey cells. In frog hepatocytes the specific binding of 125I-insulin was increased twofold in the presence of the lysosomal inhibitor chloroquine. In contrast no increase was found in lamprey hepatocytes. In conclusion, the processing pathways of internalized insulin in the cells of ectothermal and endothermal vertebrates are generally similar but in ectothermal animals all events take place at lower temperatures and at lower rates. The peculiarities of insulin processing in lamprey hepatocytes most likely result from the transformation of hepatocytes during the nonfeeding prespawning period. PMID:8575649

  17. Nicotinic binding in rat brain: autoradiographic comparison of (/sup 3/H)acetylcholine, (/sup 3/H)nicotine, and (/sup 125/I)-alpha-bungarotoxin

    SciTech Connect

    Clarke, P.B.; Schwartz, R.D.; Paul, S.M.; Pert, C.B.; Pert, A.

    1985-05-01

    Three radioligands have been commonly used to label putative nicotinic cholinoceptors in the mammalian central nervous system: the agonists (/sup 3/H)nicotine and (/sup 3/H)acetylcholine ((/sup 3/H)ACh--in the presence of atropine to block muscarinic receptors), and the snake venom extract, (/sup 125/I)-alpha-bungarotoxin((/sup 125/I)BTX), which acts as a nicotinic antagonist at the neuromuscular junction. Binding studies employing brain homogenates indicate that the regional distributions of both (/sup 3/H)nicotine and (/sup 3/H)ACh differ from that of (/sup 125/I)BTX. The possible relationship between brain sites bound by (/sup 3/H)nicotine and (/sup 3/H)ACh has not been examined directly. The authors have used the technique of autoradiography to produce detailed maps of (/sup 3/H)nicotine, (/sup 3/H)ACh, and (/sup 125/I)BTX labeling; near-adjacent tissue sections were compared at many levels of the rat brain. The maps of high affinity agonist labeling are strikingly concordant, with highest densities in the interpeduncular nucleus, most thalamic nuclei, superior colliculus, medial habenula, presubiculum, cerebral cortex (layers I and III/IV), and the substantia nigra pars compacta/ventral tegmental area. The pattern of (/sup 125/I)BTX binding is strikingly different, the only notable overlap with agonist binding being the cerebral cortex (layer I) and superior colliculus. (/sup 125/I)BTX binding is also dense in the inferior colliculus, cerebral cortex (layer VI), hypothalamus, and hippocampus, but is virtually absent in thalamus. Various lines of evidence suggest that the high affinity agonist-binding sites in brain correspond to nicotinic cholinergic receptors similar to those found at autonomic ganglia; BTX-binding sites may also serve as receptors for nicotine and are possibly related to neuromuscular nicotinic cholinoceptors.

  18. Mono(125I)iodo-Tyr10,MetO17)-vasoactive intestinal polypeptide. Preparation, characterization, and use for radioimmunoassay and receptor binding

    SciTech Connect

    Martin, J.L.; Rose, K.; Hughes, G.J.; Magistretti, P.J.

    1986-04-25

    Vasoactive intestinal polypeptide (VIP) was labeled with sodium (125I)iodide using the chloramine-T method and subsequently purified by reverse-phase high performance liquid chromatography.Three main 125I-labeled peaks designated A, B, and C resulted from the radioiodination and purification procedures. They were characterized by electrophoresis of tryptic fragments; Edman degradation (for Peaks A and C); enzymatic digestion to amino acids by leucine aminopeptidase, carboxypeptidase Y and Pronase; and treatment with cyanogen bromide. Peak A corresponds to VIP monoiodinated on Tyr10 and with the Met17 residue oxidized to methionine sulfoxide. This (mono(125I)iodo-Tyr10,MetO17)VIP displays the following characteristics. 1) It constitutes quantitatively the major product of the iodination procedure (62.5%); 2) it is well resolved from other labeled and unlabeled products; 3) it is stable (2 months at -20 degrees C); 4) it possesses a high specific activity (2050 Ci/mmol); 5) it maintains the biological activity of native VIP; and 6) it binds to antibody and membrane recognition sites in a specific, saturable, and reversible manner. Reduction of (mono(125I)iodo-Tyr10, Met-O17)VIP to (mono(125I)iodo-Tyr10)VIP does not improve the performance of the tracer in a radioimmunoassay. The method described in this article is simple and rapid and yields a molecular form of 125I-labeled VIP that has been fully characterized and is suitable for use in biological studies.

  19. Autoradiographic localization of delta opioid receptors within the mesocorticolimbic dopamine system using radioiodinated (2-D-penicillamine, 5-D-penicillamine)enkephalin ( sup 125 I-DPDPE)

    SciTech Connect

    Dilts, R.P.; Kalivas, P.W. )

    1990-01-01

    The enkephalin analog (2-D-penicillamine, 5-D-penicillamine)enkephalin was radioiodinated (125I-DPDPE) and shown to retain a pharmacological selectivity characteristic of the delta opioid receptor in in vitro binding studies. The distributions of 125I-DPDPE binding, using in vitro autoradiographic techniques, were similar to those previously reported for the delta opioid receptor. The nucleus accumbens, striatum, and medial prefrontal cortex contain dense gradients of 125I-DPDPE binding in regions known to receive dopaminergic afferents emanating from the mesencephalic tegmentum. Selective chemical lesions of the ventral tegmental area and substantia nigra were employed to deduce the location of the 125I-DPDPE binding within particular regions of the mesocorticolimbic dopamine system. Unilateral lesions of dopamine perikarya (A9 and A10) within the ventral tegmental area and substantia nigra produced by mesencephalic injection of 6-hydroxydopamine resulted in significant (20-30%) increases in 125I-DPDPE binding contralateral to the lesion within the striatum and nucleus accumbens. Lesions of the perikarya (dopaminergic and nondopaminergic) of the ventral tegmental area, induced by quinolinic acid injections, caused increases of less magnitude within these same nuclei. No significant alterations in 125I-DPDPE binding were observed within the mesencephalon as a result of either treatment. The specificity of the lesions was confirmed by immunocytochemistry for tyrosine hydroxylase. These results suggest that the enkephalins and opioid agonists acting through delta opioid receptors do not directly modulate dopaminergic afferents but do regulate postsynaptic targets of the mesocorticolimbic dopamine system.

  20. Comparison of permanent 125I seeds implants with two different techniques in 500 cases of prostate cancer

    PubMed Central

    Ricós, Jose Vicente; Tortajada, Maria Isabel; Santos, Miguel Angel; Casanova, Juan; Clemente, Jose; Samper, Josefa; Santamaría, Paula; Arribas, Leoncio

    2015-01-01

    Purpose To perform a comparative study of 500 consecutive 125I seeds implants for intracapsular prostate carcinoma with two techniques differing in terms of both strand implantation and planning. Material and methods From 2002 to 2007 we performed 250 implants with fixed stranded seeds (RapidStrand™) and a preplanning system and from 2007 to 2010, 250 with real-time and ProLink™ system. Mean age was 68 and 66, respectively, median PSA (prostate-specific antigen) 7.3 and 7.2, stage T1-T2a in 98% and 94%, and Gleason ≤ 6 in 96% and 86%. Low risk cases were 81% and 71%. The prescribed dose was 145 Gy to the prostate volume, or 108 Gy plus EBRT 46 Gy in some intermediate risk cases. Hormonal treatment was given to 42% and 28%. Results Median follow-up was 48 and 47 months, respectively, 14 patients in the first group and 7 patients in the second developed biochemical failure (BF). Actuarial biochemical relapse-free survival (bRFS) at 5 years increased from 90.2% to 97.2% (low risk from 91.3% to 97.2%, intermediate risk from 84.2% to 97.1%). Biochemical failure was independent of hormone treatment. Rectal complications were G1-2 in 1.2% and 5.2%, respectively. A urinary catheter was necessary in 6.9% and 9.6%, and urethral resection in 1.9% and 4.4%. Genitourinary toxicity was G1-2 in 4.6% and 12%, G3-4 in 1.9% and 4.8%. An assessment of mean D90 in a sample of patients showed that the dosimetry in postoperative planning based on CT improved from a mean D90 of 143 Gy to 157 Gy. Conclusions The outcome of patients with low risk prostate carcinoma treated with 125I seed is very good with low complications rate. The real-time approach in our hands achieved a more precise seed implantation, better dosimetry, and a statistically non-significant better biochemical control. We have made this our standard technique. PMID:26622228

  1. Dosimetric effects of seed anisotropy and interseed attenuation for {sup 103}Pd and {sup 125}I prostate implants

    SciTech Connect

    Chibani, Omar; Williamson, Jeffrey F.; Todor, Dorin

    2005-08-15

    A Monte Carlo study is carried out to quantify the effects of seed anisotropy and interseed attenuation for {sup 103}Pd and {sup 125}I prostate implants. Two idealized and two real prostate implants are considered. Full Monte Carlo simulation (FMCS) of implants (seeds are physically and simultaneously simulated) is compared with isotropic point-source dose-kernel superposition (PSKS) and line-source dose-kernel superposition (LSKS) methods. For clinical pre- and post-procedure implants, the dose to the different structures (prostate, rectum wall, and urethra) is calculated. The discretized volumes of these structures are reconstructed using transrectal ultrasound contours. Local dose differences (PSKS versus FMCS and LSKS versus FMCS) are investigated. The dose contributions from primary versus scattered photons are calculated separately. For {sup 103}Pd, the average absolute total dose difference between FMCS and PSKS can be as high as 7.4% for the idealized model and 6.1% for the clinical preprocedure implant. Similarly, the total dose difference is lower for the case of {sup 125}I: 4.4% for the idealized model and 4.6% for a clinical post-procedure implant. Average absolute dose differences between LSKS and FMCS are less significant for both seed models: 3 to 3.6% for the idealized models and 2.9 to 3.2% for the clinical plans. Dose differences between PSKS and FMCS are due to the absence of both seed anisotropy and interseed attenuation modeling in the PSKS approach. LSKS accounts for seed anisotropy but not for the interseed effect, leading to systematically overestimated dose values in comparison with the more accurate FMCS method. For both idealized and clinical implants the dose from scattered photons represent less than 1/3 of the total dose. For all studied cases, LSKS prostate DVHs overestimate D{sub 90} by 2 to 5% because of the missing interseed attenuation effect. PSKS and LSKS predictions of V{sub 150} and V{sub 200} are overestimated by up to 9% in

  2. Early CT findings after interstitial radiation therapy for primary malignant brain tumors

    SciTech Connect

    Tolly, T.L.; Bruckman, J.E.; Czarnecki, D.J.; Frazin, L.J.; Lewis, H.J.; Richards, M.J.; Adamkiewicz, J.J. Jr.

    1988-11-01

    The CT findings after interstitial radiation therapy for brain tumors have not been extensively described. We evaluated retrospectively the CT scans of 13 patients who were treated with brachytherapy for malignant glioma. We found no typical CT appearance that differentiates recurrent tumor from radiation effect. After undergoing brachytherapy, eight of the 13 patients scanned demonstrated enhancement of brain tissue beyond the margins of the original enhancing tumor mass. In most cases, the pattern of enhancement diminished and extended more peripherally from the central necrotic area with time. We also report a new CT finding of focal calcification developing at the site of the radioactive implant.

  3. Three-dimensional ultrasound system for guided breast brachytherapy

    SciTech Connect

    De Jean, Paul; Beaulieu, Luc; Fenster, Aaron

    2009-11-15

    Breast-conserving surgery combined with subsequent radiation therapy is a standard procedure in breast cancer treatment. The disadvantage of whole-breast beam irradiation is that it requires 20-25 treatment days, which is inconvenient for patients with limited mobility or who reside far from the treatment center. However, interstitial high-dose-rate (HDR) brachytherapy is an irradiation method requiring only 5 treatment days and that delivers a lower radiation dose to the surrounding healthy tissue. It involves delivering radiation through {sup 192}Ir seeds placed inside the catheters, which are inserted into the breast. The catheters are attached to a HDR afterloader, which controls the seed placement within the catheters and irradiation times to deliver the proper radiation dose. One disadvantage of using HDR brachytherapy is that it requires performing at least one CT scan during treatment planning. The procedure at our institution involves the use of two CT scans. Performing CT scans requires moving the patient from the brachytherapy suite with catheters inserted in their breasts. One alternative is using three-dimensional ultrasound (3DUS) to image the patient. In this study, the authors developed a 3DUS translation scanning system for use in breast brachytherapy. The new system was validated using CT, the current clinical standard, to image catheters in a breast phantom. Once the CT and 3DUS images were registered, the catheter trajectories were then compared. The results showed that the average angular separation between catheter trajectories was 2.4 deg., the average maximum trajectory separation was 1.0 mm, and the average mean trajectory separation was found to be 0.7 mm. In this article, the authors present the 3DUS translation scanning system's capabilities as well as its potential to be used as the primary treatment planning imaging modality in breast brachytherapy.

  4. Interstitial Lung Diseases

    MedlinePlus

    Interstitial lung disease is the name for a large group of diseases that inflame or scar the lungs. The inflammation and scarring make it hard to ... air is responsible for some types of interstitial lung diseases. Specific types include Black lung disease among ...

  5. A simple, direct radioimmunoassay for plasma cortisol, featuring a 125I radioligand and a solid-phase separation technique.

    PubMed

    Riad-Fahmy, D; Read, G F; Gaskell, S J; Dyas, J; Hindawi, R

    1979-05-01

    A simple, direct radioimmunoassay for cortisol in human serum and plasma is described. An antiserum, raised in sheep to a cortisol-3-(O-carboxymethyl)oxime/bovine serum albumin conjugate, is coupled to microcellulose. No extraction is required because plasma samples and standards are incubated with the antiserum and an 125I radioligand in a low-pH buffer, which denatures cortisol-binding globulins. The assay satisfies accepted validation criteria. In addition, results from the radioimmunoassay compare well with those obtained by a gas chromatographic-mass spectrometric technique (r = 0.968; FRIA = 0.97 FGCMS + 2.0 nmol/L). The latter procedure features the very high intrinsic specificity obtained by selected ion monitoring at high mass-spectrometric resolution (M/deltaM = 8500) with a Varian MAT-731 instrument. The simplicity of the radioimmunoassay procedure, with use of reagents prepared "in house," makes this a very practical and economical assay for use in the medium or large endocrine laboratory. PMID:436230

  6. Preliminary observations on the results of combined /sup 125/I seed implantation and external irradiation for carcinoma of the prostate

    SciTech Connect

    Ross, G. Jr.; Borkon, W.D.; Landry, L.J.; Edwards, F.M.; Weinstein, S.H.; Abadir, R.

    1982-04-01

    Fifty-seven patients with localized carcinoma of the prostate were treated with pelvic lymphadenectomy and a reduced /sup 125/I implant dosage, supplemented by a moderate dose of external beam radiotherapy to the whole pelvis delivered 4 to 6 weeks later. The incidence of pelvic nodal metastases was 28 per cent and the operative morbidity was 15 per cent. Late radiation sequelae developed in 18 patients, including 15 patients with radiation proctitis (29 per cent), among whom 2 (4.6 per cent) suffered rectal ulceration and required diverting colostomy. Followup has been 2 years or longer (median 33 months) in 26 patients, of whom 22 (85 per cent) are free of disease. Three patients are living with osseous metastases or local disease and there has been 1 death of prostatic carcinoma, for an absolute 2-year survival rate of 95 per cent. Of the 7 patients with poorly differentiated tumor and of the 8 patients with positive pelvic lymph nodes 5 and 6, respectively, remain free of disease after a minimum 2-year followup. Potency has been lost in 20 per cent and reduced significantly in 30 per cent of the patients followed 18 months or longer. Prostatic biopsies on 28 asymptomatic patients 12 to 30 months after completion of therapy showed no tumor in 21 (75 per cent).

  7. Comparison of binding of /sup 125/I-iodopindolol to control and desensitized cells at 37 degrees and on ice

    SciTech Connect

    Toews, M.L.; Waldo, G.L.; Harden, T.K.; Perkins, J.P.

    1986-01-01

    Binding of /sup 125/I-iodopindolol (IPIN) to intact 1321N1 human astrocytoma cell B-adrenergic receptors was measured at 37 degrees and on ice. Control cells showed a single component of IPIN binding on ice with the same total number of receptors as measured at 37 degrees. In desensitized cells (pretreated for 20 min with 1 microM isoproterenol) approximately 40% of IPIN binding on ice exhibited kinetics similar to those observed in control cells. The remaining 60% of receptors were labelled by IPIN at a much slower rate requiring the use of very high concentrations of IPIN. Sucrose density gradient fractionation was used to separately study the labelling of plasma membrane receptors and those associated with a light vesicle fraction. Labelling by IPIN on ice of the plasma membrane receptors of control cells was rapid, labelling of the light vesicle receptors of desensitized cells was slow, and labelling of the plasma membrane receptors of desensitized cells appeared to occur with both rapid and slow components. Selective labelling of the plasma membrane receptors of intact cells thus could be obtained by incubation with IPIN on ice under selected conditions. Similar results were obtained when broken cell preparations from control and desensitized cells were used. The decreased binding of IPIN on ice to B-adrenergic receptors in the light vesicle fraction not only provides further evidence consistent with sequestration of B-adrenergic receptors during desensitization, it also provides a convenient and inexpensive means to assay the sequestration reaction.

  8. Identification of cross-reactive promastigote cell surface antigens of some leishmanial stocks by 125I labeling and immunoprecipitation.

    PubMed Central

    Gardiner, P R; Jaffe, C L; Dwyer, D M

    1984-01-01

    Externally oriented surface membrane constituents of promastigotes from several Leishmania species were radiolabeled with 125I. Autoradiographs of cell surface-labeled and sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated proteins of the stocks revealed distinctive patterns of bands in the molecular weight range of 6,000 to 240,000. Immunoprecipitation of detergent extracts of the labeled promastigote stocks with anti-Leishmania donovani membrane serum demonstrated that each of the stocks contained some antigenically cross-reactive determinants. The electrophoretic patterns of these determinants serve both to distinguish the parasite stocks (by unique, species-specific patterns) and to indicate antigenic similarities in stocks thought to be different by other biochemical criteria. At least 12 cross-reactive cell surface antigens in two New World leishmanias are recognized by polyvalent anti-L. donovani serum, suggesting that these common leishmanial antigens may account for the documented serological cross-reactivities among various Leishmania species. In all stocks tested, an iodinated protein was identified which had a relative molecular weight of 65,000 under reducing conditions but which demonstrated an increase in relative mobility in sodium dodecyl sulfate-polyacrylamide gels under nonreducing conditions. Distinctive patterns of the antigens common to the several stocks were also demonstrated with the use of monoclonal antibodies. Images PMID:6363295

  9. /sup 125/I-labeled radioimmunoassay kits for progesterone evaluated for use in an in vitro fertilization program

    SciTech Connect

    Blight, L.F.; White, G.H.

    1983-06-01

    We have evaluated two commercially available /sup 125/I radioimmunoassay kits (Diagnostic Products Corp., DPC; and Radioassay Systems Laboratories, RSL) for measurement of serum or plasma progesterone, to determine their suitability for use in in vitro fertilization programs. Both kits were suitably rapid for program requirements. Results by both were linear with concentration up to 60 nmol/L, and both had acceptable lower detection limits of 0.3 nmol/L. Kit-determined progesterone concentrations (y) for 100 patients' samples correlated well with results by our existing 3H radioimmunoassay method (y . 1.11x + 0.2, r . 0.965 for the DPC kit; y . 1.01x + 1.4, r . 0.974 for the RSL kit). Mean analytical recovery for the RSL kit was 116%, that for the DPC kit, 202%. Within-batch precision, expressed as the mean CV for three concentrations of progesterone, was 6.5% for the RSL kit, and 16.4% for the DPC kit; between-day CV was 8.1% for the RSL kit, 17.7% for the DPC kit. We conclude that the RSL kit provides a rapid, precise, and accurate assay for serum progesterone, suitable for use in a fertilization program, but do not recommend the DPC kit for either this purpose or the more general purpose of tracking menstrual cycles.

  10. (125)I-spectramide: A novel benzamide displaying potent and selective effects at the D sub 2 dopamine receptor

    SciTech Connect

    Sanchez-Roa, P.M.; Grigoriadis, D.E.; Wilson, A.A.; Sharkey, J.; Dannals, R.F.; Villemagne, Victor, L.; Wong, D.F.; Wagner, H.N. Jr.; Kuhar, M.J. )

    1989-01-01

    The new substituted benzamide Spectramide, (N-(2-(4-iodobenzyl-N-methylamino)-2-methoxy-4-ethyl)-5-chloro-methylamine benzamide) labelled with {sup 125}I was used as a potent and highly selective dopamine-D{sub 2} receptor antagonist in rat striatal homogenates for in vitro receptor binding. Kinetic experiments demonstrated the reversibility of the binding and the estimated Kd from saturation analysis was 25 pM, with a Bmax of 20 pmol/g of tissue. Competition studies showed that spectramide did not interact potently with the D{sub 1} or dopamine-uptake site. Drugs known to interact with other receptor system were weak competitors of the binding, while binding was potently inhibited by other D{sub 2} antagonists, such as spiperone and eticlopride. These data indicate that Spectramide binds selectively and with high affinity to the dopamine D{sub 2} receptors, and may prove to be a useful tool for the study of these receptors in vivo using PET or SPECT.

  11. The absorption of 125I-labelled immunoglobulin G by different regions of the gut in young rats

    PubMed Central

    Morris, B.; Morris, R.

    1974-01-01

    1. 125I-labelled homologous IgG was injected into different regions of the small intestine of rats aged 12, 16, 18, 20 and 22 days. At 12 days the proximal and middle regions of the intestine readily absorbed globulin and transmitted it to the circulation. The distal region of the intestine transmitted little to the circulation at all ages tested. 2. The intestine loses its ability to transmit globulin to the circulation in a distal-proximal direction. At 16 and 18 days the ability of the middle region had declined significantly, and this decline continued so that little globulin was transmitted from this region at 20 and 22 days. 3. The proximal intestine retained the ability to transmit globulin to the circulation in significant amounts up to 20 days. 4. There is a close negative correlation between body weight and total radioactivity of the sera of rats which had received doses of labelled globulin into the proximal and middle regions of the intestine. There was no such correlation after injection into the distal intestine — suggesting a restricted throughput of radioactive material by the absorptive cells of this region. 5. These results are discussed in the context of the termination of antibody absorption, and in relation to the results obtained using polyvinyl pyrrolidone. PMID:4436816

  12. High correlation between prolactinemia, 125-I hLH binding and progesterone secretion by an experimental luteoma

    SciTech Connect

    Lux, V.A.R.; Tesone, M.; Larrea, G.A.; Libertun, C.

    1984-12-03

    Autoimplantation of an ovary, containing fresh corpora lutea, into the spleen of an ovariectomized rat is followed by strong luteinization and size increase of the grafted gonad. Thus, large amounts of luteal tissue for biochemical studies, and their histological controls are available. Furthermore, progesterone secretion can be easily determined in samples collected from the portal vein. Since prolactin has been implicated in the control of luteal tissue, the role of this hormone on hLH binding and progesterone secretion was determined. Different levels of endogenous serum prolactin were achieved by pharmacological treatments with neurotropic agents. Scatchard plots of 125-I hLH binding data derived from luteoma particulate fractions revealed the presence of one type of binding site with high affinity. At the same time as binding increased, prolactinemia augmented, with a high correlation (R:0.99) between prolactinemia and LH binding. Moreover, progesterone secreted by the luteoma increased as LH binding sites augmented (R:0.97). It is conclude that a high correlation between prolactinemia and LH binding, as well as between this last parameter and progesterone output exists in the experimental luteoma. 40 references, 2 figures, 1 table.

  13. Erythropoietin messenger RNA levels in developing mice and transfer of /sup 125/I-erythropoietin by the placenta

    SciTech Connect

    Koury, M.J.; Bondurant, M.C.; Graber, S.E.; Sawyer, S.T.

    1988-07-01

    Erythropoietin (EP) mRNA was measured in normal and anemic mice during fetal and postnatal development. Normal fetal livers at 14 d of gestation contained a low level of EP mRNA. By day 19 of gestation, no EP mRNA was detected in normal or anemic fetal livers or normal fetal kidneys, but anemic fetal kidneys had low levels of EP mRNA. Newborn through adult stage mice responded to anemia by accumulating renal and hepatic EP mRNA. However, total liver EP mRNA was considerably less than that of the kidneys. Juvenile animals, 1-4 wk old, were hyperresponsive to anemia in that they produced more EP mRNA than adults. Moreover, nonanemic juveniles had readily measured renal EP mRNA, whereas the adult level was at the lower limit of detection. Because of the very low level of fetal EP mRNA, placental transfer of EP was evaluated. When administered to the pregnant mouse, /sup 125/I-EP was transferred in significant amounts to the fetuses. These results indicate that in mice the kidney is the main organ of EP production at all stages of postnatal development and that adult kidney may also play some role in providing EP for fetal erythropoiesis via placental transfer of maternal hormone.

  14. Lactoperoxidase-125I localization of salt-extractable alkaline phosphatase on the cytoplasmic membrane of Bacillus licheniformis.

    PubMed

    Spencer, D B; Hulett, F M

    1981-02-01

    Previous histochemical and biochemical localizations of alkaline phosphatase in Bacillus licheniformis MC14 have shown that the membrane-associated form of the enzyme is located on the inner surface of the cytoplasmic membrane, and soluble forms are located in the periplasmic space and in the growth medium. The distribution of salt-extractable alkaline phosphatase on the surfaces of the cytoplasmic membrane of B. licheniformis MC14 was determined by using lactoperoxidase-125I labeling techniques. Cells harvested during rapid alkaline phosphatase production were converted to protoplasts or lysed protoplasts and labeled. Analysis of the data obtained indicated that 30% of the salt-extractable, membrane-associated alkaline phosphatase was located on the outer surface of the cytoplasmic membrane, whereas 70% of the membrane-associated enzyme was localized on the inner surface. Controls for protoplast integrity (release of tritiated thymidine or examination of cytoplasmic proteins for label content) indicated excellent protoplast stability. Controls indicated that chemical labeling was not a factor in the apparent distribution of alkaline phosphatase on the membrane. These results support the previously reported histochemical localization of alkaline phosphatase on the membrane inner surface. The presence of alkaline phosphatase on the membrane outer surface is reasonable, considering the soluble forms of the enzyme found in the periplasmic region and in the culture medium. PMID:7462164

  15. Lactoperoxidase-125I localization of salt-extractable alkaline phosphatase on the cytoplasmic membrane of Bacillus licheniformis.

    PubMed Central

    Spencer, D B; Hulett, F M

    1981-01-01

    Previous histochemical and biochemical localizations of alkaline phosphatase in Bacillus licheniformis MC14 have shown that the membrane-associated form of the enzyme is located on the inner surface of the cytoplasmic membrane, and soluble forms are located in the periplasmic space and in the growth medium. The distribution of salt-extractable alkaline phosphatase on the surfaces of the cytoplasmic membrane of B. licheniformis MC14 was determined by using lactoperoxidase-125I labeling techniques. Cells harvested during rapid alkaline phosphatase production were converted to protoplasts or lysed protoplasts and labeled. Analysis of the data obtained indicated that 30% of the salt-extractable, membrane-associated alkaline phosphatase was located on the outer surface of the cytoplasmic membrane, whereas 70% of the membrane-associated enzyme was localized on the inner surface. Controls for protoplast integrity (release of tritiated thymidine or examination of cytoplasmic proteins for label content) indicated excellent protoplast stability. Controls indicated that chemical labeling was not a factor in the apparent distribution of alkaline phosphatase on the membrane. These results support the previously reported histochemical localization of alkaline phosphatase on the membrane inner surface. The presence of alkaline phosphatase on the membrane outer surface is reasonable, considering the soluble forms of the enzyme found in the periplasmic region and in the culture medium. Images PMID:7462164

  16. /sup 125/I-Clq-binding and specific antibodies as indicators of pulmonary disease activity in cystic fibrosis

    SciTech Connect

    Moss, R.B.; Hsu, Y.P.; Lewiston, N.J.

    1981-08-01

    We studied the incidence and levels of circulating immune complexes by the /sup 125/I-Clq-binding assay in patients with cystic fibrosis in relation to clinical respiratory status and specific IgG and IgE antibodies to Pseudomonas aeruginosa. Staphylococcus aureus, Aspergillus fumigatus, and Candida albicans. Overall prevalence of CIC was 43%, but 86% of serially studied patients had evidence of CIC at some time. Patients with acute respiratory exacerbations and deteriorating pulmonary function had a higher incidence of CIC (76%) as compared to stable patients (36%, P less than 0.01), as well as significantly higher levels of CIC. Acute exacerbations were also associated with significant increases in IgG antibody to Pseudomonas (P less than 0.005) but not in other antibodies. CIC did not correlate with Pseudomonas-specific IgG nor with any other specific antibody studied. A variety of age-related differences in specific antibody levels were seen. The episodic appearance of CIC is common in CF and is usually associated with exacerbation of lung disease.

  17. Direct /sup 125/I-radioligand assays for serum progesterone compared with assays involving extraction of serum

    SciTech Connect

    Ratcliffe, W.A.; Corrie, J.E.; Dalziel, A.H.; Macpherson, J.S.

    1982-06-01

    Researchers compared two direct radioimmunoassays for progesterone in 50 microL of unextracted serum or plasma with assays involving extraction of serum. The direct assays include the use of either danazol at pH 7.4 or 8-anilino-1-naphthalenesulfonic acid at pH 4.0 to displace progesterone from serum binding-proteins. Progesterone is then assayed by using an antiserum to a progesterone 11 alpha hemisuccinyl conjugate and the radioligand /sup 125/I-labeled progesterone 11 alpha-glucuronyl tyramine, with separation by double-antibody techniques. Direct assays with either displacing agent gave good analytical recovery of progesterone added to human serum, and progesterone values for patients' specimens correlated well (r greater than 0.96) with results of assays involving extraction of serum. Precision was similar with each displacing agent over the working range 2.5-100 nmol/L and superior to that of extraction assays. Researchers conclude that these direct assays of progesterone are analytically valid and more robust, precise, and technically convenient than many conventional methods involving extraction of serum.

  18. /sup 125/I-FK 33-824: a selective probe for radioautographic labeling of mu opioid receptors in the brain

    SciTech Connect

    Moyse, E.; Pasquini, F.; Quirion, R.; Beaudet, A.

    1986-03-01

    The selectivity of the Met-enkephalin analog FK 33-824 (FK) for mu opioid receptors has been, over the years, a matter of controversy. We report here pharmacological and radioautographic data demonstrating that at nanomolar concentrations. /sup 125/I-FK interacts exclusively with mu sites. (1) Specific binding of /sup 125/I-FK to rat striatal membranes is totally inhibited by mu- and/or delta-preferring ligands according to monovalent, Michaelian kinetics, with a potency proportional to the affinity of competing drugs for mu receptors. (2) Unlabeled FK competes only at high concentration with the delta-selective ligand 3H-DPLPE and according to the same kinetics as the mu-selective agonist DAGO. (3) /sup 125/I-FK generates the same regional radioautographic labeling pattern as 3H-DAGO. We conclude that when used at nanomolar concentrations /sup 125/I-FK constitutes a selective probe for the radioautographic detection of mu opioid receptors at both light and electron microscopic levels.

  19. Two saturable recognition sites for (-) (125I)iodo-N6-(4-hydroxyphenyl-isopropyl)-adenosine binding on purified cardiac sarcolemma

    SciTech Connect

    Hausleithner, V.; Freissmuth, M.; Schuetz, W.

    1986-01-01

    Analysis of (-) (125)iodo-N6-(4-hydroxyphenylisopropyl)-adenosine (( /sup 125/I)HPIA) binding to purified sarcolemmal preparations of guinea pig and bovine hearts revealed two classes of binding sites when unlabeled iodo-HPIA (100 mumol/l) was used as non-specific binding marker. In the presence of 1 mmol/l theophylline, however, only the high affinity component was detected. Adenosine receptor agonists caused biphasic displacement of (/sup 125/I)HPIA binding, with a high affinity potency rank order typical of interaction with A1-adenosine receptors. Biphasic competition curves were also observed with 8-phenyltheophylline and isobutylmethylxanthine, whereas the theophylline curve was monophasic up to 1 mmol/l. In brain membranes, specific binding of (/sup 125/I)HPIA as well as of (/sup 3/H)PIA was further reduced when unlabeled iodo-HPIA replaces theophylline as the non-specific binding marker. These results suggest the presence of two (/sup 125/I)HPIA binding sites on cardiac sarcolemma and brain membranes, but receptor function can only be ascribed to the high affinity sites. The low affinity site probably represents an artefact, which is often observed when non-specific binding is defined with the unlabeled counterpart or a structurally related ligand of the radioligand used.

  20. Experimental and Monte Carlo determination of the TG-43 dosimetric parameters for the model 9011 THINSeed brachytherapy source

    SciTech Connect

    Kennedy, R. M.; Davis, S. D.; Micka, J. A.; DeWerd, L. A.

    2010-04-15

    Purpose: AAPM TG-43 brachytherapy dosimetry parameters for a new, smaller diameter {sup 125}I brachytherapy source (THINSeed, model 9011) were determined using LiF:Mg,Ti thermoluminescent dosimeter (TLD-100) microcubes and Monte Carlo simulations. Methods: Two polymethyl methacrylate phantoms were machined to hold TLD-100 microcubes at specific locations for the experimental determination of the radial dose function, dose-rate constant, and anisotropy functions of the new source. The TG-43 parameters were also calculated using Monte Carlo simulations. For comparison, the model 6711 source was also investigated. Results: Experimental results for both models 9011 and 6711 sources showed good agreement with Monte Carlo values, as well as with previously published values. Conclusions: The TG-43 parameters for the new source model are similar to those of model 6711; however, they represent two separate sources and TG-43 parameters used in treatment planning must be source specific.

  1. Feasibility of preoperative 125I seed-guided tumoural tracer injection using freehand SPECT for sentinel lymph node mapping in non-palpable breast cancer

    PubMed Central

    2014-01-01

    Background This study was designed to explore the feasibility of replacing the conventional peri-/intratumoural ultrasound (US)-guided technetium-99m albumin nanocolloid (99mTc-nanocolloid) administration by an injection of the same tracer guided by a freehand single-photon emission computed tomography (SPECT) device in patients with non-palpable breast cancer with an iodine-125 (125I) seed as tumour marker, who are scheduled for a sentinel lymph node biopsy (SLNB). This approach aimed to decrease the workload of the radiology department, avoiding a second US-guided procedure. Methods In ten patients, the implanted 125I seed was primarily localised using freehand SPECT and subsequently verified by conventional US in order to inject the 99mTc-nanocolloid. The following 34 patients were injected using only freehand SPECT localisation. In these patients, additional SPECT/CT was acquired to measure the distance between the 99mTc-nanocolloid injection depot and the 125I seed. In retrospect, a group of 21 patients with US-guided 99mTc-nanocolloid administrations was included as a control group. Results The depth difference measured by US and freehand SPECT in ten patients was 1.6 ± 1.6 mm. In the following 36 125I seeds (34 patients), the average difference between the 125I seed and the centre of the 99mTc-nanocolloid injection depot was 10.9 ± 6.8 mm. In the retrospective study, the average distance between the 125I seed and the centre of the 99mTc-nanocolloid injection depot as measured in SPECT/CT was 9.7 ± 6.5 mm and was not significantly different compared to the freehand SPECT-guided group (two-sample Student's t test, p = 0.52). Conclusion We conclude that using freehand SPECT for 99mTc-nanocolloid administration in patients with non-palpable breast cancer with previously implanted 125I seed is feasible. This technique may improve daily clinical logistics, reducing the workload of the radiology department. PMID:24949282

  2. Comparison of (/sup 125/I)beta-endorphin binding to rat brain and NG108-15 cells using a monoclonal antibody directed against the opioid receptor

    SciTech Connect

    Bidlack, J.M.; O'Malley, W.E.; Schulz, R.

    1988-02-01

    The properties of (/sup 125/I)beta h-endorphin-binding sites from rat brain membranes and membranes from the NG108-15 cell line were compared using a monoclonal antibody directed against the opioid receptor and opioid peptides as probes. The binding of (/sup 125/I)beta h-endorphin to both rat brain and NG108-15 membranes yielded linear Scatchard plots with Kd values of 1.2 nM and 1.5 nM, respectively, and Bmax values of 865 fmol/mg rat brain membrane protein and 1077 fmol/mg NG108-15 membrane protein. A monoclonal antibody, OR-689.2.4, capable of inhibiting mu and delta binding but not kappa binding to rat brain membranes, noncompetitively inhibited the binding of 1 nM (/sup 125/I)beta h-endorphin to rat brain and NG108-15 membranes with an IC50 value of 405 nM for rat brain membranes and 543 nM for NG108-15 membranes. The monoclonal antibody also inhibited the binding of 3 nM (/sup 3/H) (D-penicillamine2, D-penicillamine5) enkephalin to NG108-15 membranes with an IC50 value of 370 nM. In addition to blocking the binding of (/sup 125/I)beta h-endorphin to brain membranes, the antibody also displaced (/sup 125/I)beta h-endorphin from membranes. Site-specific opioid peptides had large variations in their IC50 values depending on whether they were inhibiting (/sup 125/I)beta h-endorphin binding to rat brain or the NG108-15 membranes. When the peptides were tested with the monoclonal antibody for their combined ability to inhibit (/sup 125/I)beta h-endorphin binding to both membrane preparations, the peptides and antibody blocked binding as though they were acting at allosterically coupled sites, not two totally independent sites. These studies suggest that mu-, delta-, and beta-endorphin-binding sites share some sequence homology with the 35,000-dalton protein that the antibody is directed against.

  3. /sup 125/I-Fibrin deposition in contact sensitivity reactions in the mouse. Sensitivity of the assay for quantitating reactions after active or passive sensitization

    SciTech Connect

    Mekori, Y.A.; Dvorak, H.F.; Galli, S.J.

    1986-03-15

    The clotting associated with delayed hypersensitivity (DH) responses in the mouse by sensitizing the animals to the contactant oxazolone (Ox), and then administering /sup 125/I-guinea pig fibrinogen i.v. 10 to 30 min before antigen challenge 5 days later. Early (4 to 8 hr) contact sensitivity (CS) responses in immunized mice were barely detectable by three conventional measures of CS, but the total /sup 125/I-cpm in ears challenged with hapten was 3.6 to 4.5 x that in control ears challenged with vehicle alone; moreover, the amount of urea-insoluble cpm (cross-linked /sup 125/I-fibrin-associated cpm) in the reactions to Ox was 6.5-fold to 8.2-fold that present in the control reactions. In 24 hr reactions that were near peak intensity by measurements of ear swelling, ear weight ratios, and ratios of /sup 125/I-5-iodo-2-deoxyuridine-labeled leukocyte infiltration, the cpm in antigen-challenged ears exceeded that in control ears by 13-fold to 53-fold. In addition, antigen-challenged ears contained 27 to 300 x the urea-insoluble cpm present in control ears. /sup 125/I-Fibrin deposition was not a specific characteristic of CS reactions, because a small amount of urea-insoluble reactivity was also detected in some reactions to Ox in native mice. Nevertheless, the assay was exquisitely sensitive and readily detected quantitative differences between the immunologically specific and nonspecific reactions at very early intervals after challenge or with suboptimal doses of antigen.

  4. Photolabeling of membrane-bound Torpedo nicotinic acetylcholine receptor with the hydrophobic probe 3-trifluoromethyl-3-(m-(/sup 125/I)iodophenyl)diazirine

    SciTech Connect

    White, B.J.; Cohen, J.B.

    1988-11-29

    The hydrophobic, photoactivatable probe 3-trifluoromethyl-3-(m-(/sup 125/I)iodophenyl)diazirine ((/sup 125/I)TID) was used to label acetylcholine receptor rich membranes purified from Torpedo californica electric organ. All four subunits of the acetylcholine receptor (AChR) were found to incorporate label, with the ..gamma..-subunit incorporating approximately 4 times as much as each of the other subunits. Carbamylcholine, an agonist, and histrionicotoxin, a noncompetitive antagonist, both strongly inhibited labeling of all AChR subunits in a specific and dose-dependent manner. In contrast, the competitive antagonist ..cap alpha..-bungarotoxin and the noncompetitive antagonist phencyclidine had only modest effect on (/sup 125/I)TID labeling of the AChR. The regions of the AChR ..cap alpha..-subunit that incorporate (/sup 125/)TID were mapped by Staphylococcus aureus V8 protest digestion. The carbamylcholine-sensitive site of labeling was localized to a 20-kDa V8 cleavage fragment that begins at Ser-173 and is of sufficient length to contain the three hydrophobic regions M1, M2, and M3. A 10-kDa fragment beginning at Asn-339 and containing the hydrophobic region M4 also incorporated (/sup 125/I)TID but in a carbamylcholine-insensitive manner. Two further cleavage fragments, which together span about one-third of the ..cap alpha..-subunit amino terminus, incorporated no detectable (/sup 125/I)TID. The mapping results place constraints on suggested models of AChR subunit topology.

  5. Tritiated-nicotine- and /sup 125/I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. II. Effects of habenular destruction

    SciTech Connect

    Clarke, P.B.; Hamill, G.S.; Nadi, N.S.; Jacobowitz, D.M.; Pert, A.

    1986-09-15

    The cholinergic innervation of the interpeduncular nucleus (IPN) is wholly extrinsic and is greatly attenuated by bilateral habenular destruction. We describe changes in the labeling of putative nicotinic receptors within this nucleus at 3, 5, or 11 days after bilateral habenular lesions. Adjacent tissue sections of the rat IPN were utilized for /sup 3/H-nicotine and /sup 125/I-alpha-bungarotoxin (/sup 125/I-BTX) receptor autoradiography. Compared to sham-operated controls, habenular destruction significantly reduced autoradiographic /sup 3/H-nicotine labeling in rostral (-25%), intermediate (-13%), and lateral subnuclei (-36%). Labeling in the central subnucleus was unchanged. Loss of labeling was maximal at the shortest survival time (3 days) and did not change thereafter. In order to establish whether this loss was due to a reduction in the number or the affinity of /sup 3/H-nicotine-binding sites, a membrane assay was performed on microdissected IPN tissue from rats that had received surgery 3 days previously. Bilateral habenular lesions produced a 35% reduction of high-affinity /sup 3/H-nicotine-binding sites, with no change in binding affinity. Bilateral habenular lesions reduced /sup 125/I-BTX labeling in the intermediate subnuclei, and a slight increase occurred in the rostral subnucleus. In the lateral subnuclei, /sup 125/I-BTX labeling was significantly reduced (27%) at 3 days but not at later survival times. In view of the known synaptic morphology of the habenulointerpeduncular tract, it is concluded that a subpopulation of /sup 3/H-nicotine binding sites within the IPN is located on afferent axons and/or terminals. This subpopulation, located within rostral, intermediate, and lateral subnuclei, may correspond to presynaptic nicotinic cholinergic receptors. Sites that bind /sup 125/I-BTX may include a presynaptic subpopulation located in the lateral and possibly the intermediate subnuclei.

  6. Tritiated-nicotine and /sup 125/I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. I. Subnuclear distribution

    SciTech Connect

    Hamill, G.S.; Clarke, P.B.; Pert, A.; Jacobowitz, D.M.

    1986-09-15

    The distribution of nicotinic receptors within the interpeduncular nucleus (IPN) was determined in male rats following in vitro labeling with the cholinergic ligands /sup 3/H-nicotine and /sup 125/I-alpha-bungarotoxin (BTX). Autoradiographic images of two rostrocaudal levels of IPN were analyzed by computer-assisted densitometry and the optical density contributed by displaceable labeling was determined in the rostral, central, intermediate, and lateral subnuclei. /sup 3/H-nicotine labeling density within the four subnuclei differs significantly at both levels of IPN. The greatest density of labeling is localized in the rostral subnucleus, followed in order of diminishing density by the central, intermediate, and lateral subnuclei. Labeling within the rostral subnucleus is prominently localized within its central zone. In the central subnucleus, a dense concentration of binding sites is apparent in the middle region, adjacent to less dense vertically oriented columns; /sup 3/H-nicotine binding sites in the lateral subnuclei appear to be most concentrated medially, adjacent to the intermediate subnuclei. /sup 125/I-BTX labeling density within the four subnuclei also differs significantly at both levels of IPN. The greatest density of labeling is found in the rostral subnucleus, followed in order of decreasing density by the lateral, central, and intermediate subnuclei. The ovoid regions of the rostral subnucleus contain dense /sup 125/I-BTX labeling. In the lateral subnuclei, /sup 125/I-BTX binding appears to be predominantly along the lateral margins of the subnucleus. The present data indicate that the IPN contains two distinct populations of putative cholinergic nicotinic receptors identified, respectively, by /sup 3/H-nicotine and /sup 125/I-BTX labeling. Each population of labeled receptors is uniquely localized in patterns that suggest differences in density within and across subnuclei.

  7. Feasibility and impact of the measurement of extracellular fluid volume simultaneous with GFR by 125I-iothalamate.

    PubMed

    Visser, Folkert W; Muntinga, Jaap H J; Dierckx, Rudi A; Navis, Gerjan

    2008-09-01

    The feasibility, validity, and possible applications of the assessment of extracellular fluid volume (ECFV) simultaneous with glomerular filtration rate (GFR) were assessed in a series of validation studies using the constant infusion method of (125)I-iothalamate (IOT). In 48 subjects with a broad range of GFR, distribution volume (V(d)) of IOT corresponded well with V(d) bromide (16.71 +/- 3.0 and 16.73 +/- 3.2 l, respectively, not significant), with a strong correlation (r = 0.933, P < 0.01) and without systematic deviations. Reproducibility assessment in 25 healthy male subjects showed coefficients of variation of 8.6% of duplicate measurement of V(d) IOT during strictly standardized (50 mmol Na(+)/d) sodium intake. An increase in dietary sodium intake (200 mmol Na(+)/d) induced a corresponding rise in V(d) IOT of 1.11 +/- 1.5 l (P < 0.01). In 158 healthy prospective kidney donors, the impact of indexing of GFR to ECFV was analyzed. Age, gender, height, and body surface area (BSA) were determinants of GFR. Whereas GFR, GFR/BSA, and GFR/height were gender-dependent, GFR/ECFV was gender-independent and not related to height or BSA. This supports the potential of normalizing GFR by ECFV. Thus, ECFV can be simultaneously assessed with GFR by the constant infusion method using IOT. After appropriate validation, also other GFR tracers could be used for such a simultaneous estimation, providing a valuable resource of data on ECFV in renal studies and, moreover, allowing GFR to be indexed to the body fluid compartment it clears: the ECFV. PMID:18650405

  8. Localization of dopamine receptors in the tree shrew brain using [3H]-SCH23390 and [125I]-epidepride.

    PubMed

    Mijnster, M J; Isovich, E; Flügge, G; Fuchs, E

    1999-09-11

    The tree shrew is a mammalian species, which is phylogenetically related to insectivores and primates. The aim of the present study was to investigate the distribution of dopamine receptor D1- and D2-like binding sites in the brain of this non-rodent, non-primate mammal. Using in vitro autoradiography and employing the radioligands [3H]-SCH23390 and [125I]-epidepride, dopamine receptors were mapped and quantified. Significant findings with regard to the D1-like binding pattern include the presence of a "patchy" binding in the striatum. In the cortex, D1-like binding sites were observed in both the superficial and the deep layers. In the hippocampal formation, D1-like binding sites were seen primarily in the CAI region and not in the dentate gyrus. These characteristics of the D1 pattern in the tree shrew brain are shared by cat and monkey and human brain, but not by rodent brain. Significant findings with regard to the D2-like binding pattern include the presence of D2-like binding in the claustrum. In addition, the striatum demonstrated "patchy" D2-like binding. These characteristics of the D2 pattern in the tree shrew brain are shared by cat and monkey and human brain, but not by rodent brain. On the other hand, the significant densities of D2-like binding sites in the glomerular layer of the tree shrew olfactory bulb is a finding that discriminates tree shrews from higher evolutionary species who lack such binding. Overall, the evidence coincides with the view that tree shrews are phylogenetically related to primates. PMID:10546993

  9. Aortic lipid and /sup 125/I-albumin accumulation in streptozotocin-diabetic guinea pigs: prevention by insulin treatment

    SciTech Connect

    Schlosser, M.J.; Bannon, A.W.; Verlangieri, A.J.

    1986-03-01

    Diabetes mellitus, a major risk factor of atherosclerosis, is associated with the aortic accumulation of macromolecules. The authors have examined this relationship in the streptozotocin (STZ)-diabetic guinea pig, a species (like man) unable to synthesize ascorbic acid and susceptible to atherosclerosis. Male Dunkin-Hartley guinea pigs received STZ (150 mg/kg, i.c.) or vehicle (control). After 5 days, insulin (10 U/kg/day) was given to half the STZ animals (STZ-INS0 while the remaining half (STZ-SAL) and controls received saline. 25 days later, animals were given /sup 125/I-albumin (100 ..mu..Ci/kg, i.a.). Activity was determined in plasma at 5 (C/sub p5), 15 and 30 minutes, and in the upper thoracic aorta after 30 minutes. Histopathological changes were evaluated in the lower aorta. Aortic albumin permeability defined as cpm/cm/sup 2//sec, cpm/cm/sup 2//sec/C/sub p5/, or cpm/C/sub p5//g tissue was significantly elevated in the STZ-SAL group compared to both STZ-INS and control groups; these latter two groups were not significantly different from each other. Oil-Red-O positive material (lipid) occurred at multifocal areas within the intima of the STZ-SAL animals only. This study demonstrates (1) an abnormal increase in aortic permeability to albumin, (2) histological evidence of early atherosclerotic lesions, and (3) that insulin treatment can prevent these angiopathies in this STZ-diabetic animal model.

  10. Salvage Brachytherapy for Biochemically Recurrent Prostate Cancer following Primary Brachytherapy

    PubMed Central

    Lacy, John M.; Wilson, William A.; Bole, Raevti; Chen, Li; Meigooni, Ali S.; Rowland, Randall G.; Clair, William H. St.

    2016-01-01

    Purpose. In this study, we evaluated our experience with salvage brachytherapy after discovery of biochemical recurrence after a prior brachytherapy procedure. Methods and Materials. From 2001 through 2012 twenty-one patients treated by brachytherapy within University of Kentucky or from outside centers developed biochemical failure and had no evidence of metastases. Computed tomography (CT) scans were evaluated; patients who had an underseeded portion of their prostate were considered for reimplantation. Results. The majority of the patients in this study (61.9%) were low risk and median presalvage PSA was 3.49 (range 17.41–1.68). Mean follow-up was 61 months. At last follow-up after reseeding, 11/21 (52.4%) were free of biochemical recurrence. There was a trend towards decreased freedom from biochemical recurrence in low risk patients (p = 0.12). International Prostate Symptom Scores (IPSS) increased at 3-month follow-up visits but decreased and were equivalent to baseline scores at 18 months. Conclusions. Salvage brachytherapy after primary brachytherapy is possible; however, in our experience the side-effect profile after the second brachytherapy procedure was higher than after the first brachytherapy procedure. In this cohort of patients we demonstrate that approximately 50% oncologic control, low risk patients appear to have better outcomes than others. PMID:27092279

  11. Large-angle ionization chambers for brachytherapy air-kerma-strength measurements

    NASA Astrophysics Data System (ADS)

    Culberson, Wesley S.

    There has been a significant increase in the use of low-energy photon-emitting radionuclides in the past decade to treat cancer with a special form of radiation therapy called brachytherapy. For treating prostate cancer, brachytherapy sources are approximately the size of a grain of rice and are normally radioactive 125I or 103Pd sources encapsulated in titanium or plastic. Although these sources have proven effective in the treatment of cancer, the clinical dosimetry is difficult due to the unique varieties available and their typically. A large-angle free-air chamber at the National Institute of Standards and Technology (NIST) called the Wide-Angle Free-Air Chamber (WAFAC) is the current standard for measuring the strength of low-energy photon-emitting radionuclides for brachytherapy. This chamber has served the clinical medical physics community well and is a significant improvement over previous standards. However, it has some shortcomings. This thesis describes the development of a new large-angle ionization chamber at the University of Wisconsin called the Variable-Aperture Free-Air Chamber (VAFAC) to measure brachytherapy sources with extended capabilities. This chamber is constructed to explore characteristics in the calibration of brachytherapy seeds by quantifying potential variations caused by anisotropy and the change in response with integration angle. In addition, the characterization of yet another large-angle free-air chamber called the Grossvolumen Extrapolationskammer (GROVEX) in the German national standards institute Physikalisch-Technische Bundesanstalt (PTB) is also presented. The objective of this thesis is to present improved measurement techniques with free-air ionization chambers that will improve the accuracy of the dose delivered to patients. First, it will be shown that the UW VAFAC is capable of measuring conventional 125I or 103Pd seeds as well as longer sources, coiled sources, and miniature x-ray tubes. Additionally, the VAFAC

  12. New National Air-Kerma Standard for Low-Energy Electronic Brachytherapy Sources

    PubMed Central

    Seltzer, Stephen M; O’Brien, Michelle; Mitch, Michael G

    2014-01-01

    The new primary standard for low-energy electronic brachytherapy sources for the United States is described. These miniature x-ray tubes are inserted in catheters for interstitial radiation therapy and operate at tube potentials of up to about 50 kV. The standard is based on the realization of the air kerma produced by the x-ray beam at a reference distance in air of 50 cm. PMID:26601044

  13. Preparation and properties of (R)-(-)-1-azabicyclo(2. 2. 2)oct-3-yl- (R)-(+)-alpha-hydroxy-alpha-(4-( sup 125 I)iodophenyl)-alpha-phenyl acetate and (R)-(-)-1-azabicyclo(2. 2. 2)oct-3-yl-(S)-(-)-alpha-hydroxy-alpha- (4-( sup 125 I)iodophenyl)-alpha-phenyl acetate as potential radiopharmaceuticals

    SciTech Connect

    Cohen, V.I.; Rzeszotarski, W.J.; Gibson, R.E.; Fan, L.H.; Reba, R.C. )

    1989-10-01

    rac-4-Nitrobenzilic acid was synthesized and resolved with quinidine and quinine to give the corresponding (R)- and (S)-salts. The resolved diastereomeric salts were converted to (R)- and (S)-4-nitrobenzilic acids and subsequent esterification gave their corresponding ethyl esters. Transesterification with (R)-(-)-3-quinuclidinol afforded (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(R)-(+)-alpha-hydroxy-alpha- (4-nitrophenyl)-alpha-phenyl acetate and (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(S)-(-)-alpha-hydroxy- alpha-(4-nitrophenyl)-alpha-phenyl acetate. After hydrogenation, the (R,R)- and (R,S)-amines were converted to the respective triazene derivatives. The triazene derivatives reacted with sodium ({sup 125}I)iodide to give (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(R)-(+)- alpha-hydroxy-alpha-(4-({sup 125}I)iodophenyl)-alpha-phenyl acetate and (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(S)-(-)-alpha-hydroxy- alpha-(4-(125I)iodophenyl)-alpha-phenyl acetate. The evaluation of their affinities to muscarinic acetylcholine receptors (MAcChR) shows that (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(S)-(-)-alpha-hydroxy-alpha-(4- ({sup 125}I)iodophenyl)-alpha-phenyl acetate exhibits an affinity for the MAcChR from corpus striatum that is approximately threefold lower than that of (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(R)-(+)-alpha-hydroxy-alpha-(4- ({sup 125}I)iodophenyl)-alpha-phenyl acetate.

  14. In vivo visualization of prostate brachytherapy seeds with photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin U.; Boctor, Emad M.

    2014-12-01

    We conducted a canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. A fiber coupled to a 1064-nm Nd:YAG laser was inserted into high-dose-rate brachytherapy needles, which diffused light spherically. These needles were inserted through the perineum into the prostate for interstitial light delivery and the resulting acoustic waves were detected with a transrectal ultrasound probe. Postoperative computed tomography images and ex vivo photoacoustic images confirmed seed locations. Limitations with insufficient light delivery were mitigated with short-lag spatial coherence (SLSC) beamforming, providing a 10-20 dB contrast improvement over delay-and-sum (DAS) beamforming for pulse energies ranging from 6.8 to 10.5 mJ with a fiber-seed distance as large as 9.5 mm. For the same distance and the same range of energy densities, signal-to-noise ratios (SNRs) were similar while the contrast-to-noise ratio (CNR) was higher in SLSC compared to DAS images. Challenges included visualization of signals associated with the interstitial fiber tip and acoustic reverberations between seeds separated by ≤2 mm. Results provide insights into the potential for clinical translation to humans.

  15. In vivo visualization of prostate brachytherapy seeds with photoacoustic imaging

    PubMed Central

    Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin U.; Boctor, Emad M.

    2014-01-01

    Abstract. We conducted a canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. A fiber coupled to a 1064-nm Nd:YAG laser was inserted into high-dose-rate brachytherapy needles, which diffused light spherically. These needles were inserted through the perineum into the prostate for interstitial light delivery and the resulting acoustic waves were detected with a transrectal ultrasound probe. Postoperative computed tomography images and ex vivo photoacoustic images confirmed seed locations. Limitations with insufficient light delivery were mitigated with short-lag spatial coherence (SLSC) beamforming, providing a 10–20 dB contrast improvement over delay-and-sum (DAS) beamforming for pulse energies ranging from 6.8 to 10.5 mJ with a fiber-seed distance as large as 9.5 mm. For the same distance and the same range of energy densities, signal-to-noise ratios (SNRs) were similar while the contrast-to-noise ratio (CNR) was higher in SLSC compared to DAS images. Challenges included visualization of signals associated with the interstitial fiber tip and acoustic reverberations between seeds separated by ≤2 mm. Results provide insights into the potential for clinical translation to humans. PMID:25531797

  16. Edema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants - a bio-mathematical model

    NASA Astrophysics Data System (ADS)

    Yue, Ning; Chen, Zhe; Nath, Ravinder

    2002-04-01

    Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125I and 103Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T) = Vp (1 + M exp(-0.693T/Te)) where Vp is the prostate volume before implantation, M is the edema magnitude and Te is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. Λg(r) αBED), where α is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125I and 103Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of 50%, the edema increased tumour cell survival by about 1 and 2 orders of magnitude for 125I and 103Pd seed implants respectively. At the extreme (95% edema magnitude and an edema half-life of 30 days), the increase was more than 3 and 5 orders of magnitude for 125I and 103Pd seed implants respectively. The absolute increases were almost independent of TPDT and the prostate edema did not significantly change the effective treatment time. Tumour cell survival for prostate undergoing CLDRI using 125I or 103Pd seeds may be increased substantially due to the presence of edema caused by surgical trauma. This effect appears to be more pronounced for

  17. Uptake of injected 125I-ricin by rat liver in vivo. Subcellular distribution and characterization of the internalized ligand.

    PubMed Central

    Frénoy, J P; Turpin, E; Janicot, M; Gehin-Fouque, F; Desbuquois, B

    1992-01-01

    Subcellular-fractionation techniques were used to characterize the endocytic pathway followed by ricin in rat liver in vivo and tentatively identify the site(s) at which the ricin interchain disulphide bridge is split. After injection of 125I-ricin, hepatic uptake of radioactivity was maximum at 30 min (40% of injected dose). At 5 min, about 80% of the radioactivity in the homogenate was recovered in the microsomal (P) fraction, but later on the recovery of the radioactivity in the mitochondrial-lysosomal (ML) fractions progressively increased (50% at 30 min) at the expense of that in the P fraction. Subfractionation of the P and ML fractions on analytical sucrose-density gradients revealed a time-dependent translocation of the radioactivity from low- to high-density endocytic structures, with median relative densities at 5 and 60 min of about 1.15 and 1.16 (P fraction) and 1.19 and 1.22 (ML fraction) respectively. The late distribution of the radioactivity in the ML fraction was similar to that of the lysosomal marker acid phosphatase. Studies with co-injected lactose and mannan showed that ricin was internalized mainly via the mannose receptor. In the presence of mannan, the late recovery of radioactivity in the ML fraction was decreased, and the distribution of the radioactivity associated with the P fraction was shifted toward lower densities (median relative density 1.13), indicating a different pathway of endocytosis. Analysis of the radioactivity associated with the ML and S fractions by SDS/PAGE revealed a time-dependent increase in the amount of intact A- and B-chains and low-molecular-mass products. When ML fractions containing partially processed ricin were incubated at 37 degrees C at pH 5 or at pH 7.2 in the presence of ATP, only low-molecular-mass products were generated. We conclude that internalized ricin associates with endocytic structures whose size and density of equilibration increase with time, and that, although detectable in these structures

  18. Tolerance of the carotid-sheath contents to brachytherapy: an experimental study

    SciTech Connect

    Werber, J.L.; Sood, B.; Alfieri, A.; McCormick, S.A.; Vikram, B. )

    1991-06-01

    Tumor invasion of the carotid artery is a potential indication for brachytherapy, which delivers a high dose of irradiation to residual tumor while limiting the dose to adjacent healthy tissues. The tolerance of carotid-sheath contents to varying doses of brachytherapy, however, has not been clearly established. In order to evaluate brachytherapy effects on carotid-sheath contents, after-loading catheters were implanted bilaterally in 3 groups of 6 rabbits each (18 rabbits). Iridium 192 brachytherapy doses of either 5000 cGy (rad), 9000 cGy, or 13,000 cGy were delivered unilaterally, with the contralateral neck serving as a nonirradiated control in each animal. There were no carotid ruptures and wound healing was normal. Two animals from each group were killed at 6, 20, and 48 weeks. Even at the highest dose (13,000 cGy), nerve conduction studies performed on the vagus nerve prior to sacrifice revealed no increased latency, histologic changes were minimal, and carotid arteries were patent. These observations suggest that the carotid-sheath contents in healthy rabbits could tolerate high doses (up to 13,000 cGy) of low-dose-rate interstitial brachytherapy without complications.

  19. Episcleral plaque brachytherapy using ‘BARC I-125 Ocu-Prosta seeds’ in the treatment of intraocular tumors: A single-institution experience in India

    PubMed Central

    Shah, Parag K; Narendran, V; Selvaraj, U; Guhan, P; Saxena, Sanjay K; Dash, Ashutosh; Astrahan, Melvin

    2012-01-01

    Context: To analyze the results of episcleral plaque brachytherapy using indigenous Bhabha Atomic Research Centre (BARC) Iodine-125 Ocu-Prosta seeds for the management of intraocular tumors from a single institute. AIM: To report our initial experience and learning curve on the use of ‘BARC I-125 Ocu-Prosta seeds’ for the management of intraocular tumors such as choroidal melanomas, retinoblastomas and vasoproliferative tumors (VPT). Materials and Methods: We retrospectively reviewed 13 eyes of 13 patients who underwent ophthalmic brachytherapy between May 2008 to March 2012. Nine cases had choroidal melanomas; three had retinoblastomas while one case had VPT. Results: For choroidal melanomas the average apical diameter before brachytherapy was 7.6 mm and average largest basal diameter was 12.1 mm, respectively, which reduced to 4.2 mm and 7.7 mm after the procedure at an average follow-up of 24 months (range 10-43 months). Retinoblastoma and VPT also showed good regression after brachytherapy. Conclusion: Plaque radiotherapy using 125I seeds can be performed under peribulbar anesthesia and provides a viable option for the management of intraocular cancer with minimal invasiveness and surgical complications. Patients in our studies experienced excellent local tumor control. With the availability of indigenous ‘BARC I-125 Ocu-Prosta seeds’ locally, cost effective ophthalmic brachytherapy can be performed in India. PMID:22824598

  20. Magnetic resonance-guided interstitial therapy for vaginal recurrence of endometrial cancer

    SciTech Connect

    Viswanathan, Akila N. . E-mail: aviswanathan@partners.org; Cormack, Robert; Holloway, Caroline L.; Tanaka, Cynthia; O'Farrell, Desmond C.; Devlin, Phillip M.; Tempany, Clare

    2006-09-01

    Purpose: To evaluate the feasibility and to describe the acute toxicity of a real-time intraoperative magnetic resonance (MR)-image guided interstitial approach to treating vaginal recurrence of endometrial cancer. Methods and Materials: From February 2004 to April 2005, 10 patients with recurrent endometrial cancer underwent MR-guided interstitial brachytherapy. Parameters evaluated included needle placement, dose-volume histograms (DVH), and complications. Results: Magnetic resonance-image guidance resulted in accurate needle placement. Tumor DVH values included median volume, 47 cc; V100, 89%; V150, 61%; V200, 38%; D90, 71 Gy; and D100, 60 Gy. DVH of organs at risk resulted in a median D2cc of external beam and brachytherapy dose (% of brachytherapy prescription): bladder, 75Gy{sub 3} (88%); rectum, 70Gy{sub 3} (87%); and sigmoid, 56Gy{sub 3} (41%). All patients experienced either a Grade 1 or 2 acute toxicity related to the radiation; only 1 patient had Grade 3 toxicity. No toxicities were attributable to the use of MR guidance. Conclusions: Real-time MR guidance during the insertion of interstitial needles reduces the likelihood of an inadvertent insertion of the needles into the bladder and the rectum. Three-dimensional dosimetry allows estimation of the dose to organs at risk. Toxicities are limited.

  1. Brachytherapy Application With In Situ Dose Painting Administered by Gold Nanoparticle Eluters

    SciTech Connect

    Sinha, Neeharika; Cifter, Gizem; Sajo, Erno; Kumar, Rajiv; Sridhar, Srinivas; Nguyen, Paul L.; Cormack, Robert A.; Makrigiorgos, G. Mike; Ngwa, Wilfred

    2015-02-01

    Purpose: Recent studies show promise that administering gold nanoparticles (GNP) to tumor cells during brachytherapy could significantly enhance radiation damage to the tumor. A new strategy proposed for sustained administration of the GNP in prostate tumors is to load them into routinely used brachytherapy spacers for customizable in situ release after implantation. This in silico study investigated the intratumor biodistribution and corresponding dose enhancement over time due to GNP released from such GNP-loaded brachytherapy spacers (GBS). Method and Materials: An experimentally determined intratumoral diffusion coefficient (D) for 10-nm nanoparticles was used to estimate D for other sizes by using the Stokes-Einstein equation. GNP concentration profiles, obtained using D, were then used to calculate the corresponding dose enhancement factor (DEF) for each tumor voxel, using dose painting-by-numbers approach, for times relevant to the considered brachytherapy sources' lifetimes. The investigation was carried out as a function of GNP size for the clinically applicable low-dose-rate brachytherapy sources iodine-125 (I-125), palladium-103 (Pd-103), and cesium-131 (Cs-131). Results: Results showed that dose enhancement to tumor voxels and subvolumes during brachytherapy can be customized by varying the size of GNP released or eluted from the GBS. For example, using a concentration of 7 mg/g GNP, significant DEF (>20%) could be achieved 5 mm from a GBS after 5, 12, 25, 46, 72, 120, and 195 days, respectively, for GNP sizes of 2, 5, 10, 20, 30, and 50 nm and for 80 nm when treating with I-125. Conclusions: Analyses showed that using Cs-131 provides the highest dose enhancement to tumor voxels. However, given its relatively longer half-life, I-125 presents the most flexibility for customizing the dose enhancement as a function of GNP size. These findings provide a useful reference for further work toward development of potential new brachytherapy application with

  2. Perturbation of TG-43 parameters of the brachytherapy sources under insufficient scattering materials.

    PubMed

    Zehtabian, Mehdi; Sina, Sedigheh; Faghihi, Reza; Meigooni, Ali

    2013-01-01

    In the recommendations of Task Group #43 from American Association of Physicists in Medicine (AAPM TG43), methods of brachytherapy source dosimetry are recommended, under full scattering conditions. However, in actual brachytherapy procedures, sources may not be surrounded by full scattering tissue in all directions. Clinical examples include high-dose-rate (HDR) brachytherapy of the breast or low-dose-rate (LDR) brachytherapy of ocular melanoma using eye plaque treatment with 125I and 103Pd. In this work, the impact of the missing tissue on the TG-43-recommended dosimetric parameters of different brachytherapy sources was investigated. The impact of missing tissue on the TG-43-recommended dosimetric parameters of 137Cs, 192Ir, and 103Pd brachytherapy sources was investigated using the MCNP5 Monte Carlo code. These evaluations were performed by placing the sources at different locations inside a 30 × 30 × 30 cm3 cubical water phantom and comparing the results with the values of the source located at the center of the phantom, which is in a full scattering condition. The differences between the thickness of the overlying tissues for different source positions and the thickness of the overlying tissue in full scattering condition is referred to as missing tissue. The results of these investigations indicate that values of the radial dose function and 2D anisotropy function vary as a function of the thickness of missing tissue, only in the direction of the missing tissue. These changes for radial dose function were up to 5%, 11%, and 8% for 137Cs, 192Ir, and 103Pd, respectively. No significant changes are observed for the values of the dose rate constants. In this project, we have demonstrated that the TG-43 dosimetric parameters may only change in the directions of the missing tissue. These results are more practical than the published data by different investigators in which a symmetric effect of the missing tissue on the dosimetric parameters of brachytherapy

  3. Regional distribution of rat brain alpha/sub 1/-adrenergic receptors: correlation between (/sup 125/I)-heat membrane binding and in vitro autoradiography

    SciTech Connect

    Jones, L.S.; Miller, G.; Gauger, L.L.; Davis, J.N.

    1985-01-07

    (/sup 125/I)-HEAT has proven useful for in vitro autoradiography as a specific alpha/sub 1/-adrenergic radioligand. We compared the binding of (/sup 125/I)-HEAT to membranes from ten brain regions with the densitometric readings of these regions in autoradiographs. There was an excellent correlation between receptor numbers from membrane binding and relative optical densities from the autoradiography. The affinity of HEAT for binding to membranes from various regions was similar. The results of this direct comparison are further evidence that HEAT binds to alpha/sub 1/-adrenergic receptors in lightly fixed tissue sections. A further interesting observation is that in regions with a heterogeneous distribution of binding sites, membrane binding may not reflect the presence of a dense local population of receptors. 19 references, 3 figures, 1 table.

  4. Quantitative autoradiography of the binding sites for ( sup 125 I) iodoglyburide, a novel high-affinity ligand for ATP-sensitive potassium channels in rat brain

    SciTech Connect

    Gehlert, D.R.; Gackenheimer, S.L.; Mais, D.E.; Robertson, D.W. )

    1991-05-01

    We have developed a high specific activity ligand for localization of ATP-sensitive potassium channels in the brain. When brain sections were incubated with ({sup 125}I)iodoglyburide (N-(2-((((cyclohexylamino)carbonyl)amino)sulfonyl)ethyl)-5-{sup 125}I-2- methoxybenzamide), the ligand bound to a single site with a KD of 495 pM and a maximum binding site density of 176 fmol/mg of tissue. Glyburide was the most potent inhibitor of specific ({sup 125}I)iodoglyburide binding to rat forebrain sections whereas iodoglyburide and glipizide were slightly less potent. The binding was also sensitive to ATP which completely inhibited binding at concentrations of 10 mM. Autoradiographic localization of ({sup 125}I)iodoglyburide binding indicated a broad distribution of the ATP-sensitive potassium channel in the brain. The highest levels of binding were seen in the globus pallidus and ventral pallidum followed by the septohippocampal nucleus, anterior pituitary, the CA2 and CA3 region of the hippocampus, ventral pallidum, the molecular layer of the cerebellum and substantia nigra zona reticulata. The hilus and dorsal subiculum of the hippocampus, molecular layer of the dentate gyrus, cerebral cortex, lateral olfactory tract nucleus, olfactory tubercle and the zona incerta contained relatively high levels of binding. A lower level of binding (approximately 3- to 4-fold) was found throughout the remainder of the brain. These results indicate that the ATP-sensitive potassium channel has a broad presence in the rat brain and that a few select brain regions are enriched in this subtype of neuronal potassium channels.

  5. Bystander Effects Induced by Continuous Low-Dose-Rate {sup 125}I Seeds Potentiate the Killing Action of Irradiation on Human Lung Cancer Cells In Vitro

    SciTech Connect

    Chen, H.H. Jia, R.F.; Yu, L.; Zhao, M.J.; Shao, C.L.; Cheng, W.Y.

    2008-12-01

    Purpose: To investigate bystander effects of low-dose-rate (LDR) {sup 125}I seed irradiation on human lung cancer cells in vitro. Methods and Materials: A549 and NCI-H446 cell lines of differing radiosensitivity were directly exposed to LDR {sup 125}I seeds irradiation for 2 or 4 Gy and then cocultured with nonirradiated cells for 24 hours. Induction of micronucleus (MN), {gamma}H2AX foci, and apoptosis were assayed. Results: After 2 and 4 Gy irradiation, micronucleus formation rate (MFR) and apoptotic rate of A549 and NCI-H446 cells were increased, and the MFR and apoptotic rate of NCI-H446 cells was 2.1-2.8 times higher than that of A549 cells. After coculturing nonirradiated bystander cells with {sup 125}I seed irradiated cells for 24 hours, MFR and the mean number of {gamma}H2AX foci/cells of bystander A549 and NCI-H446 cells were similar and significantly higher than those of control (p <0.05), although they did not increase with irradiation dose. However, the proportion of bystander NCI-H446 cells with MN numbers {>=}3 and {gamma}H2AX foci numbers 15-19 and 20-24 was higher than that of bystander A549 cells. In addition, dimethyl sulfoxide (DMSO) treatment could completely suppress the bystander MN of NCI-H446 cells, but it suppressed only partly the bystander MN of A549 cells, indicating that reactive oxygen species are involved in the bystander response to NCI-H446 cells, but other signaling factors may contribute to the bystander response of A549 cells. Conclusions: Continuous LDR irradiation of {sup 125}I seeds could induce bystander effects, which potentiate the killing action on tumor cells and compensate for the influence of nonuniform distribution of radiation dosage on therapeutic outcomes.

  6. Biochemical and ultrastructural processing of (/sup 125/I)epidermal growth factor in rat epidermis and hair follicles: accumulation of nuclear label

    SciTech Connect

    Green, M.R.; Mycock, C.; Smith, C.G.; Couchman, J.R.

    1987-03-01

    Although the intracellular ultrastructural processing of epidermal growth factor (EGF) and its receptor have been described in cell culture systems, very few studies have examined this phenomenon in intact tissues. We have examined the ultrastructural and biochemical handling of (/sup 125/I)EGF in the epidermis and hair follicle bulb of intact, viable, 3- to 5-day-old rat skin the EGF receptor distribution of which has already been documented and in which EGF has been shown to be biologically active. After incubation of explants with 10 nM (/sup 125/I)EGF for 2.5 h at 25 degrees or 37 degrees C, radiolabel was detected over the basal cells of the epidermis and hair follicle outer root sheath, confirming previous light microscope observations. More specifically, silver grains were observed near coated and uncoated plasma membrane and coated membrane invaginations, Golgi apparatus, lysosomal structures, and nuclei. Sodium azide inhibited internalization of label, whereas a series of lysosomal inhibitors (chloroquine, monensin, and iodoacetamide) caused a slight increase in silver grains associated with lysosomal vesicles and a decrease in nuclear label. Biochemical analysis indicated that greater than 35% of radioactivity following incubation at 37 degrees C was in the form of degraded (/sup 125/I)EGF fragments and that inclusion of chloroquine, monensin, and iodoacetamide reduced this value to 20.8%, 8.6%, and 4.0%, respectively. In addition, chloramine T-prepared (/sup 125/I)EGF was found to be covalently cross-linked with low efficiency to a protein having the molecular weight of the EGF receptor. These data are discussed in the light of the effects of EGF on epithelial cell proliferation in skin.

  7. Affinity crosslinking of /sup 125/I-human beta-endorphin to cell lines possessing either mu or delta type opioid binding sites

    SciTech Connect

    Keren, O.; Gioannini, T.L.; Hiller, J.M.; Simon, E.J.

    1986-01-01

    Affinity crosslinking of human /sup 125/I-beta-Endorphin to cell lines possessing either mu or delta binding sites was carried out. Autoradiography of SDS-PAGE gels from these crosslinked cell lines revealed that these two sites contain major peptide subunits that differ in molecular size. This confirms our earlier finding in mammalian brain which demonstrated separate and distinct subunits for mu and delta opioid receptors.

  8. Binding of (/sup 125/I)-N-(p-aminophenethyl)spiroperidol to the D-2 dopamine receptor in the neurointermediate lobe of the rat pituitary gland: a thermodynamic study

    SciTech Connect

    Agui, T.; Amlaiky, N.; Caron, M.G.; Kebabian, J.W.

    1988-02-01

    The novel iodinated ligand (/sup 125/I)-N-(p-aminophenethyl)spiroperidol ((/sup 125/I)NAPS) was used to identify the D-2 dopamine receptor in the intermediate lobe of the rat pituitary gland. The binding of (/sup 125/I)NAPS was of high affinity and saturable, given that the dissociation constant and the maximal binding were 34.7 +/- 4.8 pM and 21.1 +/- 2.5 fmol/mg of protein, respectively. The ability of dopaminergic agonists and antagonists to compete with (/sup 125/I)NAPS varied markedly with incubation temperature. The marked decrease of the molar potency associated with increasing incubation temperature in the competitive displacement curve suggested that the binding of five agonists, dopamine, (-)-apomorphine, (-)-n-propylnorapomorphine, N-0434, and LY-171555, to the D-2 dopamine receptor was enthalpy-driven, with a negative change in entropy. In contrast, the binding of three antagonists, fluphenazine, (+)-butaclamol, and domperidone, was entropy-driven, with positive change in entropy, suggesting less temperature-sensitive change in the molar potency. Several molecules gave unanticipated results; the molar potency of two dopamine agonists, bromocriptine and lisuride, was much less temperature-sensitive than the other agonists used in this study. The thermodynamic parameters for the atypical agonists indicated entropy-driven binding. Conversely, the molar potency of (+)-apomorphine, a dopamine receptor antagonist, was markedly affected by incubation temperature, indicating enthalpy-driven binding. Another antagonist, YM-09151-2, was affected by the inclusion of sodium chloride in the assay system: in the absence of sodium chloride, the drug was relatively weak and displayed enthalpy-driven binding; in the presence of sodium chloride, its molar potency was increased and its binding manner turned into entropy-driven.

  9. Effects of oral contraceptives, or lanosterol, on ADP-induced aggregation and binding of /sup 125/I-fibrinogen to rat platelets

    SciTech Connect

    McGregor, L.; Toor, B.; McGregor, J.L.; Renaud, S.; Clemetson, K.J.

    1984-03-01

    The aggregation to ADP and the binding of /sup 125/I-fibrinogen to platelets from rats treated with oral contraceptives or normal platelets treated in vitro with lanosterol were compared to their respective controls. Both types of platelets showed a significant increase in ADP-induced aggregation and in binding of fibrinogen, indicating that the effect of oral contraceptives could be partly due to increased levels of lanosterol in platelet membrane.

  10. Comparison of whole body and tissue blood volumes in rainbow trout (Salmo gairdneri) with 125I bovine serum albumin and 51Cr-erythrocyte tracers

    USGS Publications Warehouse

    Gingerich, W.H.; Pityer, R.A.

    1989-01-01

    Total, packed cell and, plasma volume estimates were made for the whole body and selected tissues of rainbow trout by the simultaneous injection of radiolabelled trout erythrocyte (51Cr-RBC) and radioiodinated bovine serum albumin (125I-BSA) tracers. Blood volumes were estimated with both markers separately by the tracer-hematocrit method and as the combination of the 51Cr-RBC packed cell and 125I-BSA plasma volumes. Mean whole body blood volume was significantly less when calculated from the 51Cr-RBC tracer data (3.52±0.78 ml/100 g; ±SD) than when calculated with the 125I-BSA tracer (5.06±0.86 ml/100 g) or as the sum of the two volumes combined (4.49±0.60 ml/100 g). The whole body hematocrit (28±5%), estimated as the quotient of the 51Cr-RBC volume divided by the sum of the 125I-BSA and the 51Cr-RBC volumes, also was significantly less than the dorsal aortic microhematocrit (36±4%). Estimates of total blood volumes in most tissues were significantly smaller when calculated from the51Cr-RBC data than when calculated by the other two methods. Tissue blood volumes were greatest in highly vascularized and well perfused tissues and least in poorly vascularized tissues. The relative degree of vascularization among tissues generally remained the same regardless of whether the red cell or the plasma tracer was used to calculated blood volume. It is not clear whether the expanded plasma volume is the result of the distribution of erythrocyte-poor blood into the secondary circulation or the result of extravascular exchange of plasma proteins.

  11. Characterization of Low-Energy Photon-Emitting Brachytherapy Sources with Modified Strengths for Applications in Focal Therapy

    NASA Astrophysics Data System (ADS)

    Reed, Joshua L.

    Permanent implants of low-energy photon-emitting brachytherapy sources are used to treat a variety of cancers. Individual source models must be separately characterized due to their unique geometry, materials, and radionuclides, which all influence their dose distributions. Thermoluminescent dosimeters (TLDs) are often used for dose measurements around low-energy photon-emitting brachytherapy sources. TLDs are typically calibrated with higher energy sources such as 60Co, which requires a correction for the change in the response of the TLDs as a function of photon energy. These corrections have historically been based on TLD response to x ray bremsstrahlung spectra instead of to brachytherapy sources themselves. This work determined the TLD intrinsic energy dependence for 125I and 103Pd sources relative to 60Co, which allows for correction of TLD measurements of brachytherapy sources with factors specific to their energy spectra. Traditional brachytherapy sources contain mobile internal components and large amounts of high-Z material such as radio-opaque markers and titanium encapsulations. These all contribute to perturbations and uncertainties in the dose distribution around the source. The CivaString is a new elongated 103Pd brachytherapy source with a fixed internal geometry, polymer encapsulation, and lengths ranging from 1 to 6 cm, which offers advantages over traditional source designs. This work characterized the CivaString source and the results facilitated the formal approval of this source for use in clinical treatments. Additionally, the accuracy of a superposition technique for dose calculation around the sources with lengths >1 cm was verified. Advances in diagnostic techniques are paving the way for focal brachytherapy in which the dose is intentionally modulated throughout the target volume to focus on subvolumes that contain cancer cells. Brachytherapy sources with variable longitudinal strength (VLS) are a promising candidate for use in focal

  12. Effects of atropine treatment on in vitro and in vivo binding of 4-[125I]-dexetimide to central and myocardial muscarinic receptors.

    PubMed

    Uno, Y; Matsumura, K; Scheffel, U; Wilson, A A; Dannals, R F; Wagner, H N

    1991-01-01

    Upregulation of muscarinic cholinergic receptors (mAChR) after chronic atropine treatment has been described previously. The present study was designed to evaluate 4-iodine-125 dexetimide as an agent to determine changes in the number of mAChR. Rats were injected subcutaneously with atropine (500 mg/kg) either once or chronically, once daily for 10 days, and sacrificed 24 h later. In vitro binding assays with 4-[125I]-dexetimide showed significant increases in the number of mAChR in cerebra (21%) and ventricles (45%) after chronic atropine treatment but not after acute treatment. The affinity of binding to cerebral and ventricular mAChR declined after acute and chronic atropine treatment. In vivo studies were carried out involving intravenous injection of 4-[125I]-dexetimide 24 h after atropine treatment. Binding was markedly reduced in the brain and heart. Upregulation of mAChR, as seen in in vitro studies, could not be observed because of the remaining atropine. Occupancy of mAChR by atropine persisted as long as 7 days after one dose. The results of these studies indicate that 4-[125I]-dexetimide binding reflects the effects of atropine on central and peripheral muscarinic cholinergic receptors in vitro and in vivo. PMID:1915471

  13. Quantitative autoradiographic localization of cholecystokinin receptors in rat and guinea pig brain using sup 125 I-Bolton-Hunter-CCK8

    SciTech Connect

    Niehoff, D.L. )

    1989-03-01

    The autoradiographic localization of receptors for the brain-gut peptide cholecystokinin (CCK) has shown differences in receptor distribution between rat and guinea pig brain. However the full anatomical extent of the differences has not been determined quantitatively. In the present study, {sup 125}I-Bolton-Hunter-CCK8 ({sup 125}I-BH-CCK8) was employed in a comparative quantitative autoradiographic analysis of the distribution of CCK receptors in these two species. The pharmacological profile of {sup 125}I-BH-CCK8 binding in guinea pig forebrain sections was comparable to those previously reported for rat and human. Statistically significant differences in receptor binding between rat and guinea pig occurred in olfactory bulb, caudate-putamen, amygdala, several cortical areas, ventromedial hypothalamus, cerebellum, and a number of midbrain and brainstem nuclei. The results of this study confirm the presence of extensive species-specific variation in the distribution of CCK receptors, suggesting possible differences in the physiological roles of this peptide in different mammalian species.

  14. The standardization methods of radioactive sources (125I, 131I, 99mTc, and 18F) for calibrating nuclear medicine equipment in Indonesia

    NASA Astrophysics Data System (ADS)

    Wurdiyanto, G.; Candra, H.

    2016-03-01

    The standardization of radioactive sources (125I, 131I, 99mTc and 18F) to calibrate the nuclear medicine equipment had been carried out in PTKMR-BATAN. This is necessary because the radioactive sources used in the field of nuclear medicine has a very short half-life in other that to obtain a quality measurement results require special treatment. Besides that, the use of nuclear medicine techniques in Indonesia develop rapidly. All the radioactive sources were prepared by gravimetric methods. Standardization of 125I has been carried out by photon- photon coincidence methods, while the others have been carried out by gamma spectrometry methods. The standar sources are used to calibrate a Capintec CRC-7BT radionuclide calibrator. The results shows that calibration factor for Capintec CRC-7BT dose calibrator is 1,03; 1,02; 1,06; and 1,04 for 125I, 131I, 99mTc and 18F respectively, by about 5 to 6% of the expanded uncertainties.

  15. /sup 125/I-luteinizing hormone (LH) binding to soluble receptors from the primate (Macaca mulatta) corpus luteum: effects of ethanol exposure

    SciTech Connect

    Danforth, D.R.; Stouffer, R.L.

    1988-01-01

    In the current study, we compared the effects of ethanol on gonadotropin receptors solubilized from macaque luteal membranes to those on receptors associated with the lipid bilayer. Treatment with 1% Triton X-100 for 30 min at 4C, followed by precipitation with polyethylene glycol, resulted in recovery of 50% more binding sites for /sup 125/I-human luteinizing hormone (hLH) than were available in particulate preparations. However, the soluble receptors displayed a 3-fold lower affinity for /sup 125/I-hLH. Conditions which enhanced LH binding to particulates, i.e., 1-8% ethanol at 25C, decreased specific /sup 125/I-hLH binding to soluble receptors. Steady-state LH binding to soluble receptors during incubation at 4C was half of that observed at 25C. The presence of 8% ethanol at 4C restored LH binding to levels observed in the absence of ethanol at 25C. Thus, LH binding sites in the primate corpus luteum can be effectively solubilized with Triton X-100. The different binding characteristics of particulate and soluble receptors, including the response to ethanol exposure, suggest that the lipid environment in the luteal membrane modulates the availability and affinity of gonadotropin receptors.

  16. The self-defining critical group and its application to a measured check of the derived limit for 125I in drinking water.

    PubMed

    Bowlt, C; Howe, J R

    1992-12-01

    Using a series of daily measurements of 125I in the drinking water of North Surrey, England, from November 1988 through May 1990, the accumulated activities in the thyroids of adults drinking such water were calculated on the assumption that the fraction of ingested iodine taken up by the thyroid was f = 0.3 and the tap water consumption was C = 600 L y-1. These figures were compared with measured values of 125I activities in 42 thyroids taken at necropsy from residents in the North Surrey area who were dying during this same time period. Eight thyroids (19%) had measured activities greater than predicted, so they were named the self-defining critical group. After comparing the thyroid with the drinking water activity, the current generalized derived limit for 125I in the drinking water may be too high by a factor of 2. The reason for this appears to be the use of f = 0.3 which is the mean value for the "normal" population. Models involving critical groups should use values of parameters different from the mean. In the present case, making f = 0.6 would remove the discrepancy between measurement and prediction and would be in reasonable accord with measured distributions of f. PMID:1428890

  17. Relationship of changing delta 4-steroid 5 alpha-reductase activity to (125I)iododeoxyuridine uptake during regeneration of involuted rat prostates

    SciTech Connect

    Kitahara, S.; Higashi, Y.; Takeuchi, S.; Oshima, H. )

    1989-04-01

    To elucidate the phenotypic expression of proliferating prostatic cells, rats were castrated, and the regenerating process of involuted ventral prostates during testosterone propionate (TP) administration was investigated by examining morphology, (5-{sup 125}I)iododeoxyuridine ({sup 125}I-UdR) uptake, DNA content, weight, acid phosphatase, and delta 4-steroid 5 alpha-reductase (5 alpha-reductase) activities. Morphologically, TP treatment initially increased the number of epithelial cells lining glandular lobules and subsequently restored the shape of epithelial cells. {sup 125}I-UdR uptake peaked on Day 3 of TP treatment and stayed at higher levels than for uncastrated controls until Day 14 of treatment. Prostatic weight, protein content, acid phosphatase, and DNA content returned to uncastrated control levels by Day 14 of TP treatment. TP administration markedly stimulated prostatic 5 alpha-reductase activity, which peaked on the Day 5 of treatment and decreased to uncastrated control levels by Day 14 of treatment. It is concluded that TP administration to castrated rats initially induced active mitotic division of the remaining stem cells, followed by formation of differentiated functional epithelial cells. Prostatic 5 alpha-reductase was highly active at the initial phase of active mitotic cell division. The major portion of the increased enzyme activity can be regarded as a phenotypic expression of stem or transient cells of prostatic epithelium.

  18. Simple, rapid /sup 125/I-labeled cyclosporine double antibody/polyethylene glycol radioimmunoassay used in a pediatric cardiac transplant program

    SciTech Connect

    Berk, L.S.; Webb, G.; Imperio, N.C.; Nehlsen-Cannarella, S.L.; Eby, W.C.

    1986-01-01

    We modified the Sandoz cyclosporine radioimmunoassay because of our need for frequent clinical monitoring of cyclosporine drug levels in allo- and xenograft pediatric cardiac transplant patients. With application of a commercially available (/sup 125/I)cyclosporine label in place of (/sup 3/H)cyclosporine and a second antibody/polyethylene glycol (PEG) method of separation in place of charcoal separation, we simplified and enhanced the speed and precision of assay performance. Studies of 140 whole blood samples comparing this new method to the (/sup 3/H)cyclosporine radioimmunoassay (RIA) method of Berk and colleagues yielded a coefficient of correlation of 0.96 (p less than 0.00001) with means of 626 and 667 ng/ml for (/sup 3/H)RIA and (/sup 125/I)RIA, respectively, and a regression equation of y = 28 + 1.02x. The major advantages are that total assay time is reduced to approximately 1 h; (/sup 125/I)cyclosporine label is used, avoiding the problems associated with liquid scintillation counting; and precision is enhanced by separating bound and free fractions with second antibody/PEG. These modifications should provide for greater ease of assay performance and improved clinical utility of cyclosporine monitoring not only in the pediatric but also in the adult transplant patient.

  19. Characterization and modulation of [125I]iberiotoxin-D19Y/Y36F binding in the guinea-pig urinary bladder.

    PubMed

    Molinari, E J; Sullivan, J P; Wan, Y; Brioni, J D; Gopalakrishnan, M

    2000-01-28

    The radioligand binding characteristics of the Ca(2+)-activated K(+) channel ligand [125I]iberiotoxin-D19Y/Y36F were examined in guinea-pig urinary bladder membranes. Saturation analysis revealed a single class of high affinity binding sites in the bladder with a K(D) value of 45.6 pM and a B(max) value of 112 fmol/mg protein. Specific binding was displaced by unlabeled iberiotoxin and penitrem A, but not by blockers of other classes of K(+) channels including alpha-dendrotoxin, margatoxin and apamin. The indole alkaloids, paxilline and verruculogen, significantly increased binding by 4.5- and 4.3-fold, respectively. Tetraacetic acid derivatives such as ethylenediamine tetraacetic acid and ethyleneglycoltetraacetic acid enhanced specific [125I]iberiotoxin-D19Y/Y36F binding about 2.5-fold, which was not attributable to calcium chelation. This increase was due to a significant change in ligand binding affinity (K(D)=6.3 pM), but not due to a change in the B(max), indicating that these compounds may enhance toxin binding via allosteric interactions. Collectively, these results demonstrate that the binding sites for [125I]iberiotoxin-D19Y/Y36F present in the urinary bladder shows a pharmacological profile typical of maxi-K(+) channels and can be modulated, not only by previously known indole alkaloids, but also by tetraacetic acid analogs. PMID:10666507

  20. Uptake and therapeutic effectiveness of /sup 125/I- and /sup 211/At-methylene blue for pigmented melanoma in an animal model system

    SciTech Connect

    Link, E.M.; Brown, I.; Carpenter, R.N.; Mitchell, J.S.

    1989-08-01

    The investigations concerning a targeted radiotherapy for pigmented melanoma with a radiolabeled phenothiazine derivative, 3,7-(dimethylamino)phenazathionium chloride (methylene blue (MTB)), were continued using melanotic and amelanotic sublines of B16 melanoma. Two radionuclides, 125I and 211At, emitting Auger electrons and alpha particles, respectively, replaced 35S previously studied since their biological effectiveness is significantly higher. In vitro autoradiography revealed a selective accumulation of methylene blue labeled with either of the radioisotopes in pigmented melanoma cells but its absence in nonpigmented cells. Treatments with (125I)MTB and (211At)MTB were performed both in vitro and in vivo, with their effectiveness determined by lung clonogenic assay. (125I)MTB proved to be relatively ineffective when incorporated into melanosomes distributed in the cytoplasm, i.e., too far away from the genome. Conspicuous therapeutic effects were achieved with (211At)MTB for pigmented melanoma only. 211At itself did not affect either of the investigated sublines of B16 melanoma confirming once again the high affinity of methylene blue to melanin. Calculations of cumulative radiation doses from (211At)MTB deposited in melanotic melanoma tumors and pigmented normal organs which would be at a particular risk led to the conclusion that (211At)MTB could be used for a highly selective and very efficient targeted radiotherapy of pigmented melanomas without damaging normal tissues.

  1. 125I-DPDYN, monoiodo(D-Pro10)dynorphin(1-11): a highly radioactive and selective probe for the study of kappa opioid receptors

    SciTech Connect

    Gairin, J.E.; Jomary, C.; Pradayrol, L.; Cros, J.; Meunier, J.C.

    1986-02-13

    The mono- and diiodinated derivatives of the kappa-selective ligand (D-Pro10)dynorphin(1-11), DPDYN, were prepared. Their binding properties at the three opioid receptor types (mu, delta and kappa) were examined and compared to those of the parent peptide. The monoiodo derivative shows a general although moderate decrease in affinity and retains high kappa selectivity (KI mu/KI kappa = 48 and KI delta/KI kappa = 140). The binding properties of the diiodo derivative are found to be dramatically decreased. Radioiodination of DPDYN leads to the monoiodinated peptide with high specific activity (700-800 Ci/mmol). In guinea-pig cerebellum membranes, a kappa-specific tissue, (125I)-labelled monoiodo(D-Pro10)dynorphin(1-11), 125I-DPDYN, interacts specifically and reversibly with a single class of binding sites (Bmax = 118 fmol/mg protein) with a high affinity (KD = 0.12 nM from equilibrium experiments, 0.18 nM from kinetics studies). Therefore, because of its high specific radioactivity, high affinity and reasonably good selectivity, 125I-DPDYN designates itself as the probe of the k-opioid receptor type.

  2. Receptor binding characterization of the benzodiazepine radioligand sup 125 I-Ro16-0154: Potential probe for SPECT (Single Photon Emission Computed Tomography) brain imaging

    SciTech Connect

    Johnson, E.W.; Woods, S.W.; Zoghbi, S.; Baldwin, R.M.; Innis, R.B. ); McBride, B.J. )

    1990-01-01

    The binding of an iodinated benzodiazepine (BZ) radioligand has been characterized, particularly in regard to its potential use as a neuroreceptor brain imaging agent with SPECT (Single Photon Emission Computed Tomography). Ro16-0154 is an iodine-containing BZ antagonist and a close analog of Ro15-1788. In tissue homogenates prepared from human and monkey brain, the binding of {sup 125}I-labeled Ro16-0154 was saturable, of high affinity, and had high ratios of specific to non-specific binding. Physiological concentrations of NaCl enhanced specific binding approximately 15% compared to buffer without this salt. Kinetic studies of association and dissociation demonstrated a temperature dependent decrease in affinity with increasing temperature. Drug displacement studies confirmed that {sup 125}I-Ro16-0154 binds to the central type BZ receptor: binding is virtually identical to that of {sup 3}H-Ro15-1788 except that {sup 125}I-Ro16-0154 shows an almost 10 fold higher affinity at 37{degree}C. These in vitro results suggest that {sup 123}I-labeled Ro16-0154 shows promise as a selective, high affinity SPECT probe of the brain's BZ receptor.

  3. Pulmonary interstitial emphysema.

    PubMed Central

    Greenough, A; Dixon, A K; Roberton, N R

    1984-01-01

    Forty one of 210 preterm infants ventilated for respiratory distress syndrome in a three year period had radiological evidence of pulmonary interstitial emphysema. The development of this condition was significantly associated with malpositioning of the endotracheal tube in a main bronchus and the use of high peak pressure ventilation. Pulmonary interstitial emphysema was associated with a significant increase in the number of pneumothoraces, intraventricular haemorrhages, and the need for prolonged respiratory support, but did not increase mortality. Although in 12 infants in whom fast rate ventilation was used there was a significant reduction in the number of pneumothoraces, outcome was not altered in any other way. Fast rate ventilation may be of greater benefit if initiated before the development of pulmonary interstitial emphysema. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6508339

  4. Sensitivity of low energy brachytherapy Monte Carlo dose calculations to uncertainties in human tissue composition

    SciTech Connect

    Landry, Guillaume; Reniers, Brigitte; Murrer, Lars;