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Sample records for 192ir brachytherapy source

  1. In vivo dosimetry thermoluminescence dosimeters during brachytherapy with a 370 GBq {sup 192}Ir source

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    Cuepers, S.; Piessens, M.; Verbeke, L.; Roelstraete, A. [Onze-Lieve-Vrouw Hospitaal, Aalst (Belgium). Dept. of Radiotherapy and Oncology

    1995-12-01

    When using LiF thermoluminescence dosimeters in brachytherapy, we have to take into account the properties of a high dose rate {sup 192}Ir source (energy spectrum ranging form 9 to 885 keV, steep dose gradient in the vicinity of the source) and these of the dosimeters themselves (supralinearity, reproducibility, size). All these characteristics combine into a set of correction factors which have been determined during in phantom measurements. These results have then been used to measure the dose delivered to organs at risk (e.g. rectum, bladder, etc.) during high dose rate brachytherapy with a 370 GBq {sup 192}Ir source for patients with gynaecological tumors.

  2. Patient effective dose from endovascular brachytherapy with 192Ir sources.

    Science.gov (United States)

    Perma, L; Bianchi, C; Nicolini, G; Novario, R; Tanzi, F; Conte, L

    2002-01-01

    The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with 112Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rqndo phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from cronary treatment were 2.4 x 10(-2) mSv.GBq(-1).min(-1) for lung, 0.9 x 10(-2) mSv.GBSq(-1).min(-1) for oesophagus and 0.48 x 10(-2) mS.GBq(-1).min(-1) for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2 x 10(-2) mS.GBq(-1).min(-1) for colon, 7.8 x 10(-2) mSv.GBq(-1).min(-1) for stomach and 1.7 x 10(-2) mSv.GBq(-1).min(-1) for liver. Coronary treatment iJnvlled an efl'fective dose of (0.046 mSv.GBq(-1).min(-1), whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq(-1).min(-1); there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low.

  3. Source geometry factors for HDR 192Ir brachytherapy secondary standard well-type ionization chamber calibrations

    Science.gov (United States)

    Shipley, D. R.; Sander, T.; Nutbrown, R. F.

    2015-03-01

    Well-type ionization chambers are used for measuring the source strength of radioactive brachytherapy sources before clinical use. Initially, the well chambers are calibrated against a suitable national standard. For high dose rate (HDR) 192Ir, this calibration is usually a two-step process. Firstly, the calibration source is traceably calibrated against an air kerma primary standard in terms of either reference air kerma rate or air kerma strength. The calibrated 192Ir source is then used to calibrate the secondary standard well-type ionization chamber. Calibration laboratories are usually only equipped with one type of HDR 192Ir source. If the clinical source type is different from that used for the calibration of the well chamber at the standards laboratory, a source geometry factor, ksg, is required to correct the calibration coefficient for any change of the well chamber response due to geometric differences between the sources. In this work we present source geometry factors for six different HDR 192Ir brachytherapy sources which have been determined using Monte Carlo techniques for a specific ionization chamber, the Standard Imaging HDR 1000 Plus well chamber with a type 70010 HDR iridium source holder. The calculated correction factors were normalized to the old and new type of calibration source used at the National Physical Laboratory. With the old Nucletron microSelectron-v1 (classic) HDR 192Ir calibration source, ksg was found to be in the range 0.983 to 0.999 and with the new Isodose Control HDR 192Ir Flexisource ksg was found to be in the range 0.987 to 1.004 with a relative uncertainty of 0.4% (k = 2). Source geometry factors for different combinations of calibration sources, clinical sources, well chambers and associated source holders, can be calculated with the formalism discussed in this paper.

  4. Comparison of the hypothetical 57Co brachytherapy source with the 192Ir source

    Science.gov (United States)

    Toossi, Mohammad Taghi Bahreyni; Rostami, Atefeh; Khosroabadi, Mohsen; Khademi, Sara; Knaup, Courtney

    2016-01-01

    Aim of the study The 57Co radioisotope has recently been proposed as a hypothetical brachytherapy source due to its high specific activity, appropriate half-life (272 days) and medium energy photons (114.17 keV on average). In this study, Task Group No. 43 dosimetric parameters were calculated and reported for a hypothetical 57Co source. Material and methods A hypothetical 57Co source was simulated in MCNPX, consisting of an active cylinder with 3.5 mm length and 0.6 mm radius encapsulated in a stainless steel capsule. Three photon energies were utilized (136 keV [10.68%], 122 keV [85.60%], 14 keV [9.16%]) for the 57Co source. Air kerma strength, dose rate constant, radial dose function, anisotropy function, and isodose curves for the source were calculated and compared to the corresponding data for a 192Ir source. Results The results are presented as tables and figures. Air kerma strength per 1 mCi activity for the 57Co source was 0.46 cGyh–1 cm 2 mCi–1. The dose rate constant for the 57Co source was determined to be 1.215 cGyh–1U–1. The radial dose function for the 57Co source has an increasing trend due to multiple scattering of low energy photons. The anisotropy function for the 57Co source at various distances from the source is more isotropic than the 192Ir source. Conclusions The 57Co source has advantages over 192Ir due to its lower energy photons, longer half-life, higher dose rate constant and more isotropic anisotropic function. However, the 192Ir source has a higher initial air kerma strength and more uniform radial dose function. These properties make 57Co a suitable source for use in brachytherapy applications. PMID:27688731

  5. A Monte Carlo study on dose distribution evaluation of Flexisource 192Ir brachytherapy source

    Science.gov (United States)

    Alizadeh, Majid; Ghorbani, Mahdi; Haghparast, Abbas; Zare, Naser; Ahmadi Moghaddas, Toktam

    2015-01-01

    Aim The aim of this study is to evaluate the dose distribution of the Flexisource 192Ir source. Background Dosimetric evaluation of brachytherapy sources is recommended by task group number 43 (TG. 43) of American Association of Physicists in Medicine (AAPM). Materials and methods MCNPX code was used to simulate Flexisource 192Ir source. Dose rate constant and radial dose function were obtained for water and soft tissue phantoms and compared with previous data on this source. Furthermore, dose rate along the transverse axis was obtained by simulation of the Flexisource and a point source and the obtained data were compared with those from Flexiplan treatment planning system (TPS). Results The values of dose rate constant obtained for water and soft tissue phantoms were equal to 1.108 and 1.106, respectively. The values of the radial dose function are listed in the form of tabulated data. The values of dose rate (cGy/s) obtained are shown in the form of tabulated data and figures. The maximum difference between TPS and Monte Carlo (MC) dose rate values was 11% in a water phantom at 6.0 cm from the source. Conclusion Based on dosimetric parameter comparisons with values previously published, the accuracy of our simulation of Flexisource 192Ir was verified. The results of dose rate constant and radial dose function in water and soft tissue phantoms were the same for Flexisource and point sources. For Flexisource 192Ir source, the results of TPS calculations in a water phantom were in agreement with the simulations within the calculation uncertainties. Furthermore, the results from the TPS calculation for Flexisource and MC calculation for a point source were practically equal within the calculation uncertainties. PMID:25949224

  6. Dosimetry audit on the accuracy of 192Ir brachytherapy source strength determinations in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson Tedgren, Aasa

    2007-11-15

    The absorbed dose delivered to the patient in brachytherapy is directly proportional to the source strength in terms of the reference air-kerma rate (RAKR). Verification of this quantity by the hospitals is widely recognized as an important part of a quality assurance program. An external audit was performed on behalf of the Secondary Standard Dosimetry Laboratory at the Swedish Radiation Protection Authority (SSI). The aim was to investigate how accurately the source-strength in 192Ir brachytherapy is determined at Swedish hospitals. The SSI reference well-type ion chamber and calibrated equipment were used to measure the RAKR of an 192Ir source in each of the 14 Swedish afterloading units. Comparisons with values determined by vendors and hospitals were made. Agreement in values of RAKR as determined by SSI, hospitals and vendors were in all cases within the +-3% uncertainty (at a coverage factor of k=2), typically guaranteed by the vendors. The good agreement reflects the robustness and easy handling of well-type chambers designed for brachytherapy in use by all Swedish hospitals. The 192Ir calibration service planned at SSI will solve the hospitals current problem with recalibration of equipment. SSI can also advise hospitals to follow the IAEA recommendations for measurement techniques and maintenance of equipment. It is worthwhile for the hospitals to establish their own ratio (or deviation) with the vendor and follow it as function of time. Such a mean-ratio embeds systematic differences of various origins and have a lower uncertainty than has the RAKR alone, making it useful for early detection of problems with equipment or routines. SSI could also define requirements for the agreement between source strengths as determined by hospitals and vendors and couple this to an action plan, dependent on level of disagreement, and some kind of reporting to SSI

  7. Film dosimetry calibration method for pulsed-dose-rate brachytherapy with an 192Ir source.

    Science.gov (United States)

    Schwob, Nathan; Orion, Itzhak

    2007-05-01

    192Ir sources have been widely used in clinical brachytherapy. An important challenge is to perform dosimetric measurements close to the source despite the steep dose gradient. The common, inexpensive silver halide film is a classic two-dimensional integrator dosimeter and would be an attractive solution for these dose measurements. The main disadvantage of film dosimetry is the film response to the low-energy photon. Since the photon energy spectrum is known to vary with depth, the sensitometric curves are expected to be dependent on depth. The purpose of this study is to suggest a correction method for silver halide film dosimetry that overcomes the response changes at different depths. Sensitometric curves have been obtained at different depths with verification film near a 1 Ci 192Ir pulsed-dose-rate source. The depth dependence of the film response was observed and a correction function was established. The suitability of the method was tested through measurement of the radial dose profile and radial dose function. The results were compared to Monte Carlo-simulated values according to the TG43 formalism. Monte Carlo simulations were performed separately for the beta and gamma source emissions, using the EGS4 code system, including the low-energy photon and electron transport optimization procedures. The beta source emission simulation showed that the beta dose contribution could be neglected and therefore the film-depth dependence could not be attributed to this part of the source radioactivity. The gamma source emission simulations included photon-spectra collection at several depths. The results showed a depth-dependent softening of the photon spectrum that can explain the film-energy dependence.

  8. Estimation of distance error by fuzzy set theory required for strength determination of HDR (192)Ir brachytherapy sources.

    Science.gov (United States)

    Kumar, Sudhir; Datta, D; Sharma, S D; Chourasiya, G; Babu, D A R; Sharma, D N

    2014-04-01

    Verification of the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm(3) is one of the recommended methods for measuring RAKR of HDR (192)Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR (192)Ir source strength measurement.

  9. On source models for (192)Ir HDR brachytherapy dosimetry using model based algorithms.

    Science.gov (United States)

    Pantelis, Evaggelos; Zourari, Kyveli; Zoros, Emmanouil; Lahanas, Vasileios; Karaiskos, Pantelis; Papagiannis, Panagiotis

    2016-06-07

    A source model is a prerequisite of all model based dose calculation algorithms. Besides direct simulation, the use of pre-calculated phase space files (phsp source models) and parameterized phsp source models has been proposed for Monte Carlo (MC) to promote efficiency and ease of implementation in obtaining photon energy, position and direction. In this work, a phsp file for a generic (192)Ir source design (Ballester et al 2015) is obtained from MC simulation. This is used to configure a parameterized phsp source model comprising appropriate probability density functions (PDFs) and a sampling procedure. According to phsp data analysis 15.6% of the generated photons are absorbed within the source, and 90.4% of the emergent photons are primary. The PDFs for sampling photon energy and direction relative to the source long axis, depend on the position of photon emergence. Photons emerge mainly from the cylindrical source surface with a constant probability over  ±0.1 cm from the center of the 0.35 cm long source core, and only 1.7% and 0.2% emerge from the source tip and drive wire, respectively. Based on these findings, an analytical parameterized source model is prepared for the calculation of the PDFs from data of source geometry and materials, without the need for a phsp file. The PDFs from the analytical parameterized source model are in close agreement with those employed in the parameterized phsp source model. This agreement prompted the proposal of a purely analytical source model based on isotropic emission of photons generated homogeneously within the source core with energy sampled from the (192)Ir spectrum, and the assignment of a weight according to attenuation within the source. Comparison of single source dosimetry data obtained from detailed MC simulation and the proposed analytical source model show agreement better than 2% except for points lying close to the source longitudinal axis.

  10. Investigation of Dosimetric Parameters of $^{192}$Ir MicroSelectron v2 HDR Brachytherapy Source Using EGSnrc Monte Carlo Code

    CERN Document Server

    Naeem, Hamza; Zheng, Huaqing; Cao, Ruifen; Pei, Xi; Hu, Liqin; Wu, Yican

    2016-01-01

    The $^{192}$Ir sources are widely used for high dose rate (HDR) brachytherapy treatments. The aim of this study is to simulate $^{192}$Ir MicroSelectron v2 HDR brachytherapy source and calculate the air kerma strength, dose rate constant, radial dose function and anisotropy function established in the updated AAPM Task Group 43 protocol. The EGSnrc Monte Carlo (MC) code package is used to calculate these dosimetric parameters, including dose contribution from secondary electron source and also contribution of bremsstrahlung photons to air kerma strength. The Air kerma strength, dose rate constant and radial dose function while anisotropy functions for the distance greater than 0.5 cm away from the source center are in good agreement with previous published studies. Obtained value from MC simulation for air kerma strength is $9.762\\times 10^{-8} \\textrm{UBq}^{-1}$and dose rate constant is $1.108\\pm 0.13\\%\\textrm{cGyh}^{-1} \\textrm{U}^{-1}$.

  11. Comparison of treatment planning on dosimetric differences between 192Ir sources for high-dose rate brachytherapy

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    Yang, Oh Nam [Dept. of Radiology, Mokpo Science University, Mokpo (Korea, Republic of); Shin, Seong Soo; Ahn, Woo Sang; KIm, Dae Yong; Choi, Won Sik [Dept. of Radiation Oncology, Gangenung Asan Hospital, University of Ulsan College of Medicine, Gangenung (Korea, Republic of); Kwon, Kyung Tae [Dept. of Radiologic Technology, Dongam Health University, Suwon (Korea, Republic of); Lim, Cheong Hwan [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Lee, Sang Ho [Dept. of Radiological Science, Seonam University, Namwon (Korea, Republic of)

    2016-06-15

    To evaluate whether the difference in geometrical characteristics between high-dose-rate (HDR) 192Ir sources would influence the dose distributions of intracavitary brachytherapy. Two types of microSelectron HDR 192Ir sources (classic and new models) were selected in this study. Two-dimensional (2D) treatment plans for classic and new sources were generated by using PLATO treatment planning system. We compared the point A, point B, and bladder and rectum reference points based on ICRU 38 recommendation. The radial dose function of the new source agrees with that of the classic source except difference of up to 2.6% at the nearest radial distance. The differences of anisotropy functions agree within 2% for r=1, 3, and 5 cm and 20°<θ<165°. The largest discrepancies of anisotropy functions reached up to 27% for θ<20° at r=0.25 cm and were up to 13%, 10%, and 7% at r=1, 3, and 5 cm for θ>170°, respectively. There were no significant differences in doses of point A, point B, and bladder point for the treatment plans between the new and classic sources. For the ICRU rectum point, the percent dose difference was on average 0.65% and up to 1.0%. The dose discrepancies between two treatment plans are mainly affected due to the geometrical difference of the source and the sealed capsule.

  12. Determination of the chemical yield on the Fricke dosimetry for {sup 192}Ir sources used in brachytherapy; Determinacao do rendimento quimico na dosimetria Fricke para fontes de {sup 192}Ir usadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    David, M.G.; Albuquerque, M.A.G.; Almeida, C.E. de, E-mail: marianogd08@gmail.com [Universidade do Estado do Rio de Janeiro (LCR/UERJ), Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas; Salata, C. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Rosado, P.H. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    With the aim of developing a primary standard for the absorbed dose to water, for the {sup 192}Ir sources used in high dose rate brachytherapy, this work focuses on the determination of the chemical yield, G(Fe{sup +3}), using Fricke dosimetry, for the energy of those sources . The G(Fe{sup +3}) were determined the for three qualities of x-ray beams (150, 250 and 300 kV ) and for {sup 60}Co energy. The G(Fe{sup +3}) value for the average energy of {sup 192}Ir was obtained by linear fit, the found value was 1,555 ± 0,015 μmol/J. (author)

  13. Comparative dosimetry of GammaMed Plus high-dose rate 192 Ir brachytherapy source

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    Patel N

    2010-01-01

    Full Text Available The comparative dosimetry of GammaMed (GM Plus high-dose rate brachytherapy source was performed by an experiment using 0.1-cc thimble ionization chamber and simulation-based study using EGSnrc code. In-water dose measurements were performed with 0.1-cc chamber to derive the radial dose function (r = 0.8 to 20.0 cm and anisotropy function (r = 5.0 cm with polar angle from 10° to 170°. The nonuniformity correction factor for 0.1-cc chamber was applied for in-water measurements at shorter distances from the source. The EGSnrc code was used to derive the dose rate constant (L, radial dose function g L (r and anisotropy function F(r, q of GM Plus source. The dosimetric data derived using EGSnrc code in our study were in very good agreement relative to published data for GM Plus source. The radial dose function up to 12 cm derived from measured dose using 0.1-cc chamber was in agreement within ±3% of data derived by the simulation study.

  14. Using LiF:Mg,Cu,P TLDs to estimate the absorbed dose to water in liquid water around an {sup 192}Ir brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, P. Avilés, E-mail: paz.aviles@ciemat.es; Aubineau-Lanièce, I.; Lourenço, V.; Vermesse, D.; Cutarella, D. [CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette (France)

    2014-01-15

    Purpose: The absorbed dose to water is the fundamental reference quantity for brachytherapy treatment planning systems and thermoluminescence dosimeters (TLDs) have been recognized as the most validated detectors for measurement of such a dosimetric descriptor. The detector response in a wide energy spectrum as that of an{sup 192}Ir brachytherapy source as well as the specific measurement medium which surrounds the TLD need to be accounted for when estimating the absorbed dose. This paper develops a methodology based on highly sensitive LiF:Mg,Cu,P TLDs to directly estimate the absorbed dose to water in liquid water around a high dose rate {sup 192}Ir brachytherapy source. Methods: Different experimental designs in liquid water and air were constructed to study the response of LiF:Mg,Cu,P TLDs when irradiated in several standard photon beams of the LNE-LNHB (French national metrology laboratory for ionizing radiation). Measurement strategies and Monte Carlo techniques were developed to calibrate the LiF:Mg,Cu,P detectors in the energy interval characteristic of that found when TLDs are immersed in water around an{sup 192}Ir source. Finally, an experimental system was designed to irradiate TLDs at different angles between 1 and 11 cm away from an {sup 192}Ir source in liquid water. Monte Carlo simulations were performed to correct measured results to provide estimates of the absorbed dose to water in water around the {sup 192}Ir source. Results: The dose response dependence of LiF:Mg,Cu,P TLDs with the linear energy transfer of secondary electrons followed the same variations as those of published results. The calibration strategy which used TLDs in air exposed to a standard N-250 ISO x-ray beam and TLDs in water irradiated with a standard{sup 137}Cs beam provided an estimated mean uncertainty of 2.8% (k = 1) in the TLD calibration coefficient for irradiations by the {sup 192}Ir source in water. The 3D TLD measurements performed in liquid water were obtained with a

  15. A simplified analytical approach to estimate the parameters required for strength determination of HDR 192Ir brachytherapy sources using a Farmer-type ionization chamber.

    Science.gov (United States)

    Kumar, Sudhir; Srinivasan, P; Sharma, S D; Mayya, Y S

    2012-01-01

    Measuring the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR (192)Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR (192)Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and M(s). The seven distance method was followed to record the ionization chamber readings for parameterization of f and M(s). Analytically calculated values of M(s) were used to determine the room scatter correction factor (K(sc)). The Monte Carlo simulations were also carried out to calculate f and K(sc) to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of K(sc) were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations.

  16. SU-E-T-102: Determination of Dose Distributions and Water-Equivalence of MAGIC-F Polymer Gel for 60Co and 192Ir Brachytherapy Sources

    Energy Technology Data Exchange (ETDEWEB)

    Quevedo, A; Nicolucci, P [University of Sao Paulo, Ribeirao Preto, SP (Brazil)

    2014-06-01

    Purpose: Analyse the water-equivalence of MAGIC-f polymer gel for {sup 60}Co and {sup 192}Ir clinical brachytherapy sources, through dose distributions simulated with PENELOPE Monte Carlo code. Methods: The real geometry of {sup 60} (BEBIG, modelo Co0.A86) and {sup 192}192Ir (Varian, model GammaMed Plus) clinical brachytherapy sources were modelled on PENELOPE Monte Carlo simulation code. The most probable emission lines of photons were used for both sources: 17 emission lines for {sup 192}Ir and 12 lines for {sup 60}. The dose distributions were obtained in a cubic water or gel homogeneous phantom (30 × 30 × 30 cm{sup 3}), with the source positioned in the middle of the phantom. In all cases the number of simulation showers remained constant at 10{sup 9} particles. A specific material for gel was constructed in PENELOPE using weight fraction components of MAGIC-f: wH = 0,1062, wC = 0,0751, wN = 0,0139, wO = 0,8021, wS = 2,58×10{sup −6} e wCu = 5,08 × 10{sup −6}. The voxel size in the dose distributions was 0.6 mm. Dose distribution maps on the longitudinal and radial direction through the centre of the source were used to analyse the water-equivalence of MAGIC-f. Results: For the {sup 60} source, the maximum diferences in relative doses obtained in the gel and water were 0,65% and 1,90%, for radial and longitudinal direction, respectively. For {sup 192}Ir, the maximum difereces in relative doses were 0,30% and 1,05%, for radial and longitudinal direction, respectively. The materials equivalence can also be verified through the effective atomic number and density of each material: Zef-MAGIC-f = 7,07 e .MAGIC-f = 1,060 g/cm{sup 3} and Zef-water = 7,22. Conclusion: The results showed that MAGIC-f is water equivalent, consequently being suitable to simulate soft tissue, for Cobalt and Iridium energies. Hence, gel can be used as a dosimeter in clinical applications. Further investigation to its use in a clinical protocol is needed.

  17. A simplified analytical approach to estimate the parameters required for strength determination of HDR {sup 192}Ir brachytherapy sources using a Farmer-type ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sudhir [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India); Srinivasan, P. [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sharma, S.D., E-mail: sdsharma_barc@rediffmail.com [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India); Mayya, Y.S. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Anushaktinagar, Mumbai 400094 (India)

    2012-01-15

    Measuring the strength of high dose rate (HDR) {sup 192}Ir brachytherapy sources on receipt from the vendor is an important component of a quality assurance program. Owing to their ready availability in radiotherapy departments, the Farmer-type ionization chambers are also used to determine the strength of HDR {sup 192}Ir brachytherapy sources. The use of a Farmer-type ionization chamber requires the estimation of the scatter correction factor along with positioning error (c) and the constant of proportionality (f) to determine the strength of HDR {sup 192}Ir brachytherapy sources. A simplified approach based on a least squares method was developed for estimating the values of f and M{sub s}. The seven distance method was followed to record the ionization chamber readings for parameterization of f and M{sub s}. Analytically calculated values of M{sub s} were used to determine the room scatter correction factor (K{sub sc}). The Monte Carlo simulations were also carried out to calculate f and K{sub sc} to verify the magnitude of the parameters determined by the proposed analytical approach. The value of f determined using the simplified analytical approach was found to be in excellent agreement with the Monte Carlo simulated value (within 0.7%). Analytically derived values of K{sub sc} were also found to be in good agreement with the Monte Carlo calculated values (within 1.47%). Being far simpler than the presently available methods of evaluating f, the proposed analytical approach can be adopted for routine use by clinical medical physicists to estimate f by hand calculations. - Highlights: Black-Right-Pointing-Pointer RAKR measurement of a brachytherapy source by 7 distance method requires the evaluation of 'f'. Black-Right-Pointing-Pointer A simplified analytical approach based on least square method to evaluate 'f' and 'M{sub s}' was developed. Black-Right-Pointing-Pointer Parameter 'f' calculated by proposed analytical

  18. Determination of air kerma standard of high dose rate {sup 192}Ir brachytherapy source; Determinacao da taxa de kerma no ar de referencia para {sup 192}Ir de alta taxa de dose para braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Pires, E.J.; Alves, C.F.E.; Leite, S.P.; Magalhaes, L.A.G.; David, M.G.; Almeida, C.E. de, E-mail: cfealves@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas; Di Prinzio, R. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This paper presents the methodology developed by the Laboratorio de Ciencias Radiologicas and presently in use for determining of the air kerma standard of {sup 192}Ir high dose rate sources to calibrate well-type chambers. Uncertainty analysis involving the measurements procedure are presented. (author)

  19. Determination of absorbed dose in water at the reference point d(r0, theta0) for an 192Ir HDR brachytherapy source using a Fricke system.

    Science.gov (United States)

    Austerlitz, C; Mota, H C; Sempau, J; Benhabib, S M; Campos, D; Allison, R; DeAlmeida, C E; Zhu, D; Sibata, C H

    2008-12-01

    A ring-shaped Fricke device was developed to measure the absolute dose on the transverse bisector of a 192Ir high dose rate (HDR) source at 1 cm from its center in water, D(r0, theta0). It consists of a polymethylmethacrylate (PMMA) rod (axial axis) with a cylindrical cavity at its center to insert the 192Ir radioactive source. A ring cavity around the source with 1.5 mm thickness and 5 mm height is centered at 1 cm from the central axis of the source. This ring cavity is etched in a disk shaped base with 2.65 cm diameter and 0.90 cm thickness. The cavity has a wall around it 0.25 cm thick. This ring is filled with Fricke solution, sealed, and the whole assembly is immersed in water during irradiations. The device takes advantage of the cylindrical geometry to measure D(r0, theta0). Irradiations were performed with a Nucletron microselectron HDR unit loaded with an 192Ir Alpha Omega radioactive source. A Spectronic 1001 spectrophotometer was used to measure the optical absorbance using a 1 mL quartz cuvette with 1.00 cm light pathlength. The PENELOPE Monte Carlo code (MC) was utilized to simulate the Fricke device and the 192Ir Alpha Omega source in detail to calculate the perturbation introduced by the PMMA material. A NIST traceable calibrated well type ionization chamber was used to determine the air-kerma strength, and a published dose-rate constant was used to determine the dose rate at the reference point. The time to deliver 30.00 Gy to the reference point was calculated. This absorbed dose was then compared to the absorbed dose measured by the Fricke solution. Based on MC simulation, the PMMA of the Fricke device increases the D(r0, theta0) by 2.0%. Applying the corresponding correction factor, the D(r0, theta0) value assessed with the Fricke device agrees within 2.0% with the expected value with a total combined uncertainty of 3.43% (k=1). The Fricke device provides a promising method towards calibration of brachytherapy radiation sources in terms of D(r0

  20. A generic high-dose rate {sup 192}Ir brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, Facundo, E-mail: Facundo.Ballester@uv.es [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Carlsson Tedgren, Åsa [Department of Medical and Health Sciences (IMH), Radiation Physics, Faculty of Health Sciences, Linköping University, Linköping SE-581 85, Sweden and Department of Medical Physics, Karolinska University Hospital, Stockholm SE-171 76 (Sweden); Granero, Domingo [Department of Radiation Physics, ERESA, Hospital General Universitario, Valencia E-46014 (Spain); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre and Royal Melbourne Institute of Technology, Melbourne, Victoria 3000 (Australia); Mourtada, Firas [Department of Radiation Oncology, Helen F. Graham Cancer Center, Christiana Care Health System, Newark, Delaware 19713 (United States); Fonseca, Gabriel Paiva [Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Zourari, Kyveli; Papagiannis, Panagiotis [Medical Physics Laboratory, Medical School, University of Athens, 75 MikrasAsias, Athens 115 27 (Greece); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Siebert, Frank-André [Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel 24105 (Germany); Sloboda, Ron S. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); and others

    2015-06-15

    Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) {sup 192}Ir source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR {sup 192}Ir source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic {sup 192}Ir source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra{sup ®} Brachy with advanced collapsed-cone engine (ACE) and BrachyVision ACUROS{sup TM}]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and PENELOPE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201){sup 3} voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR {sup 192}Ir source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by

  1. Water equivalent phantom materials for 192Ir brachytherapy

    Science.gov (United States)

    Schoenfeld, Andreas A.; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2015-12-01

    Several solid phantom materials have been tested regarding their suitability as water substitutes for dosimetric measurements in brachytherapy with 192Ir as a typical high energy photon emitter. The radial variations of the spectral photon fluence, of the total, primary and scattered photon fluence and of the absorbed dose to water in the transversal plane of the tested cylindrical phantoms surrounding a centric and coaxially arranged Varian GammaMed afterloading 192Ir brachytherapy source were Monte-Carlo simulated in EGSnrc. The degree of water equivalence of a phantom material was evaluated by comparing the radial dose-to-water profile in the phantom material with that in water. The phantom size was varied over a large range since it influences the dose contribution by scattered photons with energies diminished by single and multiple Compton scattering. Phantom axis distances up to 10 cm were considered as clinically relevant. Scattered photons with energies reaching down into the 25 keV region dominate the photon fluence at source distances exceeding 3.5 cm. The tested phantom materials showed significant differences in the degree of water equivalence. In phantoms with radii up to 10 cm, RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR phantoms show excellent water equivalence with dose deviations from a water phantom not exceeding 0.8%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene show deviations up to 2.6%. For larger phantom radii up to 30 cm, the deviations for RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR remain below 1.4%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene produce deviations up to 8.1%. PMMA plays a separate role, with deviations up to 4.3% for radii not exceeding 10 cm, but below 1% for radii up to 30 cm. As suggested by

  2. The non-uniformity correction factor for the cylindrical ionization chambers in dosimetry of an HDR 192Ir brachytherapy source

    Directory of Open Access Journals (Sweden)

    Majumdar Bishnu

    2006-01-01

    Full Text Available The aim of this study is to derive the non-uniformity correction factor for the two therapy ionization chambers for the dose measurement near the brachytherapy source. The two ionization chambers of 0.6 cc and 0.1 cc volume were used. The measurement in air was performed for distances between 0.8 cm and 20 cm from the source in specially designed measurement jig. The non-uniformity correction factors were derived from the measured values. The experimentally derived factors were compared with the theoretically calculated non-uniformity correction factors and a close agreement was found between these two studies. The experimentally derived non-uniformity correction factor supports the anisotropic theory.

  3. Comparison of air kerma standards of LNE-LNHB and NPL for 192Ir HDR brachytherapy sources: EUROMET project no 814.

    Science.gov (United States)

    Douysset, Guilhem; Sander, Thorsten; Gouriou, Jean; Nutbrown, Rebecca

    2008-03-21

    An indirect comparison has been made in the air kerma standards for high dose rate (HDR) 192Ir brachytherapy sources at the Laboratoire National Henri Becquerel (LNHB) and the National Physical Laboratory (NPL). The measurements were carried out at both laboratories between November and December 2004. The comparison was based on measurements using well-type transfer ionization chambers and two different source types, Nucletron microSelectron HDR Classic and version 2. The results show the reported calibration coefficients to agree within 0.47% to 0.63%, which is within the overall standard uncertainty of 0.65% reported by both laboratories at the time of this comparison. Following this comparison, some of the NPL primary standard correction factors were re-evaluated resulting in a change of +0.17% in the overall correction factor. The new factor was implemented in May 2006. Applying the revised chamber factor to the measurements reported in this comparison report will reduce the difference between the two standards by 0.17%.

  4. Optimization of deterministic transport parameters for the calculation of the dose distribution around a high dose-rate 192Ir brachytherapy source.

    Science.gov (United States)

    Gifford, Kent A; Price, Michael J; Horton, John L; Wareing, Todd A; Mourtada, Firas

    2008-06-01

    The goal of this work was to calculate the dose distribution around a high dose-rate 192Ir brachytherapy source using a multi-group discrete ordinates code and then to compare the results with a Monte Carlo calculated dose distribution. The unstructured tetrahedral mesh discrete ordinates code Attila version 6.1.1 was used to calculate the photon kerma rate distribution in water around the Nucletron microSelectron mHDRv2 source. MCNPX 2.5.c was used to compute the Monte Carlo water photon kerma rate distribution. Two hundred million histories were simulated, resulting in standard errors of the mean of less than 3% overall. The number of energy groups, S(n) (angular order), P(n) (scattering order), and mesh elements were varied in addition to the method of analytic ray tracing to assess their effects on the deterministic solution. Water photon kerma rate matrices were exported from both codes into an in-house data analysis software. This software quantified the percent dose difference distribution, the number of points within +/- 3% and +/- 5%, and the mean percent difference between the two codes. The data demonstrated that a 5 energy-group cross-section set calculated results to within 0.5% of a 15 group cross-section set. S12 was sufficient to resolve the solution in angle. P2 expansion of the scattering cross-section was necessary to compute accurate distributions. A computational mesh with 55 064 tetrahedral elements in a 30 cm diameter phantom resolved the solution spatially. An efficiency factor of 110 with the above parameters was realized in comparison to MC methods. The Attila code provided an accurate and efficient solution of the Boltzmann transport equation for the mHDRv2 source.

  5. Dosimetry audits in Brazil for {sup 192}Ir high dose rate brachytherapy systems

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, L.A.R. da; Paiva, E. de.; Goncalves, M.G.; Velasco, A.F.; Di Prinzio, R.; Dovales, A.C.M.; Freire, B.L.V.; Brito, R.R.A.; Giannoni, R.A.; Castelo, L.H.R. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Marechal, M.H.H. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao de Instalacoes Radiativas (CORAD)

    2005-03-15

    In Brazil, among 200 radiotherapy centres, 30 have high dose rate (HDR) {sup 192}Ir brachytherapy systems. In August 2001, the Brazilian National Nuclear Energy Commission (CNEN) started a biennial audit program to those centres having HDR systems. This program consists of visiting each centre in order to investigate the radiation protection aspects of the centres and also to measure the intensity of the brachytherapy source, in terms of air kerma strength, with a well type chamber specially designed for HDR {sup 192} Ir sources. The audit dosimetry results are compared to measurements carried out by the local institution physicist and to the source intensity value provided by the manufacturer. Two methods have been used by the Brazilian physicists for HDR {sup 192}Ir brachytherapy source dosimetry, namely the employment of a farmer type chamber calibrated according to the interpolation methodology and the use of a well type chamber to provide direct intercomparison. The larger difference obtained was 18.9% and it can be explained in terms of the lack of knowledge of the institution physicist about the interpolation methodology using the farmer type chamber. Another difference of 5.82% was found as being the lack of an updated calibration factor for the clinic well type chamber. On the basis of these results, CNEN is able to establish a maximum deviation value for the dosimetry of HDR system. Additionally, with this program the radiotherapy services have an opportunity to have their HDR {sup 192}Ir sources calibrated and to test the validity of the calibration factors for their own well type chambers, using their calibrated sources. (author)

  6. Calibration of well-type chambers in Brazil using {sup 192}Ir HDR sources

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Carlos Frederico Estrada; Pires, Evandro Jesus; David, Mariano Gazineu; Almeida, Carlos Eduardo de, E-mail: cfealves@gmail.com, E-mail: evjpires@gmail.com, E-mail: marianogd08@gmail.com, E-mail: cea71@yahoo.com.br [Universidade do Estado do Rio de Janeiro (UERJ/LCR), Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas; Di Prinzio, Renato, E-mail: rprinzio@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The results obtained by performing of a traceable calibration service for well-type reentrant ionization chamber for HDR 192Ir sources used in brachytherapy physical procedures at the Laboratorio de Ciencias Radiologicas from Universidade do Estado do Rio de Janeiro -LCR/UERJ are described. (author)

  7. Determination of absorbed dose in water at the reference point D(r{sub 0},{theta}{sub 0}) for an {sup 192}Ir HDR brachytherapy source using a Fricke system

    Energy Technology Data Exchange (ETDEWEB)

    Austerlitz, C.; Mota, H. C.; Sempau, J.; Benhabib, S. M.; Campos, D.; Allison, R.; Almeida, C. E. de; Zhu, D.; Sibata, C. H. [Department of Radiation Oncology, East Carolina University, Greenville, North Carolina 27834 (United States); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, 08028 Barcelona (Spain); Department of Radiation Oncology, East Carolina University, Greenville, North Carolina 27834 (United States); Laboratorio de Cie circumflex ncias Radiologicas, Universidade do Estado do Rio de Janeiro, 20550 Rio de Janeiro (Brazil); Department of Radiation Oncology, East Carolina University, Greenville, North Carolina 27834 (United States)

    2008-12-15

    A ring-shaped Fricke device was developed to measure the absolute dose on the transverse bisector of a {sup 192}Ir high dose rate (HDR) source at 1 cm from its center in water, D(r{sub 0},{theta}{sub 0}). It consists of a polymethylmethacrylate (PMMA) rod (axial axis) with a cylindrical cavity at its center to insert the {sup 192}Ir radioactive source. A ring cavity around the source with 1.5 mm thickness and 5 mm height is centered at 1 cm from the central axis of the source. This ring cavity is etched in a disk shaped base with 2.65 cm diameter and 0.90 cm thickness. The cavity has a wall around it 0.25 cm thick. This ring is filled with Fricke solution, sealed, and the whole assembly is immersed in water during irradiations. The device takes advantage of the cylindrical geometry to measure D(r{sub 0},{theta}{sub 0}). Irradiations were performed with a Nucletron microselectron HDR unit loaded with an {sup 192}Ir Alpha Omega radioactive source. A Spectronic 1001 spectrophotometer was used to measure the optical absorbance using a 1 mL quartz cuvette with 1.00 cm light pathlength. The PENELOPE Monte Carlo code (MC) was utilized to simulate the Fricke device and the {sup 192}Ir Alpha Omega source in detail to calculate the perturbation introduced by the PMMA material. A NIST traceable calibrated well type ionization chamber was used to determine the air-kerma strength, and a published dose-rate constant was used to determine the dose rate at the reference point. The time to deliver 30.00 Gy to the reference point was calculated. This absorbed dose was then compared to the absorbed dose measured by the Fricke solution. Based on MC simulation, the PMMA of the Fricke device increases the D(r{sub 0},{theta}{sub 0}) by 2.0%. Applying the corresponding correction factor, the D(r{sub 0},{theta}{sub 0}) value assessed with the Fricke device agrees within 2.0% with the expected value with a total combined uncertainty of 3.43%(k=1). The Fricke device provides a promising

  8. SU-E-T-787: Utility of the Two Candidate 192-Ir and 169-Yb HDR Sources for Use with a Novel Direction Modulated Brachytherapy Tandem Applicator for Cervical Cancer Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, H; Soliman, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States)

    2015-06-15

    Purpose: A novel tungsten alloy shielded, MRI-compatible, direction modulated brachytherapy (DMBT) concept tandem applicator, which enables unprecedented intensity modulation, was used to evaluate treatment plan quality improvement over a conventional tandem. The utility of the 192-Ir and 169-Yb HDR sources, for use with the DMBT applicator, was evaluated. Methods: The total diameter of the DMBT tandem applicator is 6.0 mm, which consists of 5.4-mm diameter tungsten alloy and 0.3 mm thick plastic sheath. The tandem has 6 symmetric peripheral 1.3-mm diameter grooves for the source to travel. MCNPX v.2.6 was used to simulate the 192-Ir and 169-Yb sources inside the DMBT applicator. First, TG-43 source parameters were evaluated. Second, 3D dose matrix with 1 mm3 resolution were imported into an in-house-coded inverse optimization treatment planning program to obtain optimal plans for 19 clinical cases. All plans were compared with the standard tandem and ring plans. Prescription dose was 15.0 Gy. All plans were normalized to receive the same HRCTV D90. Results: Generally, the DMBT tandem (and ring) plans were better than the conventional tandem and ring plans for 192-Ir and 169-Yb HDR sources. The mean data of D2cc for bladder, rectum, and sigmoid were 11.65±2.30 Gy, 7.47±3.05 Gy, and 9.84±2.48 Gy for Ir-192 DMBT tandem, respectively. These data for Yb-169 were 11.67±2.26 Gy, 7.44±3.02 Gy, and 9.83±2.38 Gy, respectively. The HR-CTV D98 and V100 were 16.37±1.86 Gy and 97.37 ± 1.92 Gy for Ir-192 DMBT, respectively. The corresponding values for Yb-169 were 16.43±1.86 Gy, and 97.51 ± 1.91 Gy. Plans with the 169-Yb source generally produced more favorable results where V100 increased by 13.65% while D2cc across all OARs reduced by 0.54% compared with the 192-Ir plans. Conclusion: For the DMBT tandem applicator, 169-Yb source seems to produce more directional beams resulting in increased intensity modulation capacity, thus resulting in more conformal plans.

  9. Ruby-based inorganic scintillation detectors for 192Ir brachytherapy

    Science.gov (United States)

    Kertzscher, Gustavo; Beddar, Sam

    2016-11-01

    We tested the potential of ruby inorganic scintillation detectors (ISDs) for use in brachytherapy and investigated various unwanted luminescence properties that may compromise their accuracy. The ISDs were composed of a ruby crystal coupled to a poly(methyl methacrylate) fiber-optic cable and a charge-coupled device camera. The ISD also included a long-pass filter that was sandwiched between the ruby crystal and the fiber-optic cable. The long-pass filter prevented the Cerenkov and fluorescence background light (stem signal) induced in the fiber-optic cable from striking the ruby crystal, which generates unwanted photoluminescence rather than the desired radioluminescence. The relative contributions of the radioluminescence signal and the stem signal were quantified by exposing the ruby detectors to a high-dose-rate brachytherapy source. The photoluminescence signal was quantified by irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and compared the ISDs to commonly used organic scintillator detectors (BCF-12, BCF-60). When the brachytherapy source dwelled 0.5 cm away from the fiber-optic cable, the unwanted photoluminescence was reduced from  >5% to  5% within 10 s from the onset of irradiation and after the source had retracted. The ruby-based ISDs generated signals of up to 20 times that of BCF-12-based detectors. The study presents solutions to unwanted luminescence properties of ruby-based ISDs for high-dose-rate brachytherapy. An optic filter should be sandwiched between the ruby crystal and the fiber-optic cable to suppress the photoluminescence. Furthermore, we recommend avoiding ruby crystals that exhibit significant time-dependent luminescence.

  10. Determination of the Fricke G value for HDR {sup 192}Ir sources using ionometric measurements

    Energy Technology Data Exchange (ETDEWEB)

    Franco, L.; Coelho, M.; Almeida, C.E. de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Lab. de Ciencias Radiologicas; Gavazza, S. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    High Dose Rate (HDR) brachytherapy using {sup 192}Ir is widely accepted as an important treatment option, and it thus requires an accurate dosimetry standard. However, a dosimetry standard for the direct measurement of absolute dose to water is currently not available. The dose to water conversion is calculated via the dose rate constant {Lambda} and several correction factors accounting for the scatter, attenuation, and anisotropy of the dose distribution, among other effects. Two potentially useful procedures have been reported, including one by Sarfehnia et al. [3,4], which used a water-based calorimeter with an uncertainty of 1.9% for k=1, and a second by Austerlitz et al. and de Almeida et al., which used Fricke dosimetry with estimated uncertainties of 3.9% for k=1 and 1.4% for k=1, respectively. Chemical dosimetry using a standard FeSO{sub 4} solution has shown potential to be a reliable standard of absorbed dose for the HDR {sup 192}Ir source. A major uncertainty is associated with the G values reported by Fregene, which had a numerical value of 1.1 %. However, that reference provided very little detail of the experimental procedures for the {sup 192}Ir source. The G value may be obtained by using a calorimeter or ionometric measurements. In the absence of calorimetric data, this paper makes an attempt to measure the G value for the HDR {sup 192}Ir sources using ionometric measurements and recommendations from dosimetry protocols. (author)

  11. Dedicated high dose rate 192Ir brachytherapy radiation fields for in vitro cell exposures at variable source-target cell distances: killing of mammalian cells depends on temporal dose rate fluctuation

    Science.gov (United States)

    Veigel, Cornelia; Hartmann, Günther H.; Fritz, Peter; Debus, Jürgen; Weber, Klaus-Josef

    2017-02-01

    Afterloading brachytherapy is conducted by the stepwise movement of a radioactive source through surgically implanted applicator tubes where at predefined dwell positions calculated dwell times optimize spatial dose delivery with respect to a planned dose level. The temporal exposure pattern exhibits drastic fluctuations in dose rate at a given coordinate and within a single treatment session because of the discontinuous and repeated source movement into the target volume. This could potentially affect biological response. Therefore, mammalian cells were exposed as monolayers to a high dose rate 192Ir source by utilizing a dedicated irradiation device where the distance between a planar array of radioactive source positions and the plane of the cell monolayer could be varied from 2.5 mm to 40 mm, thus varying dose rate pattern for any chosen total dose. The Gammamed IIi afterloading system equipped with a nominal 370 GBq (10 Ci) 192-Ir source was used to irradiate V79 Chinese hamster lung fibroblasts from both confluent and from exponential growth phase with dose up to 12 Gy (at room temperature, total exposure not exceeding 1 h). For comparison, V79 cells were also exposed to 6 MV x-rays from a clinical linear accelerator (dose rate of 2.5 Gy min‑1). As biological endpoint, cell survival was determined by standard colony forming assay. Dose measurements were conducted with a diamond detector (sensitive area 7.3 mm2), calibrated by means of 60Co radiation. Additionally, dose delivery was simulated by Monte Carlo calculations using the EGSnrc code system. The calculated secondary electron fluence spectra at the cell location did not indicate a significant change of radiation quality (i.e. higher linear energy transfer) at the lower distances. Clonogenic cell survival curves obtained after brachytherapy exhibited an altered biological response compared to x-rays which was characterized by a significant reduction of the survival curve shoulder when dose rate

  12. Calibration of a {sup 19} {sup 2}Ir source for high dose brachytherapy using various techniques; Calibracion de una fuente de {sup 192} Ir para braquiterapia de alta tasa de dosis mediante diversas tecnicas

    Energy Technology Data Exchange (ETDEWEB)

    Montilla Prieto, Tedicel C., E-mail: tcdicel@gmaiLcam [Instituto de Oncologia Dr. Miguel Perez Carreno, Barbula (Venezuela, Bolivarian Republic of). Departamento de Fisica y Dosimetria; Padron Rivero, Alvaro D., E-mail: alvarodpadronr@yahoo.com.ve [Universidad de Carabobo, Barbula (Venezuela, Bolivarian Republic of). Facultad de Ciencias de la Salud. Departamento de Ciencias Fisiologicas

    2013-10-01

    In this research we studied three experimental procedures for calibration of a source of {sup 192}Ir to high dose rate for clinical brachytherapy use, and thus were compared and analysis of the advantages and disadvantages of each. For this study we quantified the value of the current kerma rate reference in air by three procedures: source calibration using a well chamber, with an cylindrical ionization chamber in air, and a cylindrical ionization chamber on a phantom, and this magnitude was compared with the value provided by the manufacturer of the source and thereby obtaining the deviation corresponding . Thus, it was found that the deviation corresponding to the source calibration making use of a well chamber, remained within tolerance, while the cylindrical ionization chamber in air and on phantom exceeded the standards established in some documents. However, although both the measurement in air and in the phantom are the procedures for the final calibration source, these can be used to verify that the delivered dose are in tolerance.

  13. Evaluation of PC-ISO for customized, 3D printed, gynecologic 192Ir HDR brachytherapy applicators.

    Science.gov (United States)

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-01

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. PACS number: none.

  14. Evaluation of PC-ISO for customized, 3D Printed, gynecologic 192-Ir HDR brachytherapy applicators.

    Science.gov (United States)

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-08

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. 

  15. Qualification tests for {sup 192}Ir sealed sources

    Energy Technology Data Exchange (ETDEWEB)

    Iancso, Georgeta, E-mail: georgetaiancso@yahoo.com; Iliescu, Elena, E-mail: georgetaiancso@yahoo.com; Iancu, Rodica, E-mail: georgetaiancso@yahoo.com [National Institute of R and D for Physics and Nuclear Engineering Horia Hulubei, Magurele (Romania)

    2013-12-16

    This paper describes the results of qualification tests for {sup 192}Ir sealed sources, available in Testing and Nuclear Expertise Laboratory of National Institute for Physics and Nuclear Engineering 'Horia Hulubei' (I.F.I.N.-HH), Romania. These sources had to be produced in I.F.I.N.-HH and were tested in order to obtain the authorization from The National Commission for Nuclear Activities Control (CNCAN). The sources are used for gammagraphy procedures or in gammadefectoscopy equipments. Tests, measurement methods and equipments used, comply with CNCAN, AIEA and International Quality Standards and regulations. The qualification tests are: 1. Radiological tests and measurements: dose equivalent rate at 1 m; tightness; dose equivalent rate at the surface of the transport and storage container; external unfixed contamination of the container surface. 2. Mechanical and climatic tests: thermal shock; external pressure; mechanic shock; vibrations; boring; thermal conditions for storage and transportation. Passing all tests, it was obtained the Radiological Security Authorization for producing the {sup 192}Ir sealed sources. Now IFIN-HH can meet many demands for this sealed sources, as the only manufacturer in Romania.

  16. A feasibility study of Fricke dosimetry as an absorbed dose to water standard for 192Ir HDR sources.

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo deAlmeida

    Full Text Available High dose rate brachytherapy (HDR using 192Ir sources is well accepted as an important treatment option and thus requires an accurate dosimetry standard. However, a dosimetry standard for the direct measurement of the absolute dose to water for this particular source type is currently not available. An improved standard for the absorbed dose to water based on Fricke dosimetry of HDR 192Ir brachytherapy sources is presented in this study. The main goal of this paper is to demonstrate the potential usefulness of the Fricke dosimetry technique for the standardization of the quantity absorbed dose to water for 192Ir sources. A molded, double-walled, spherical vessel for water containing the Fricke solution was constructed based on the Fricke system. The authors measured the absorbed dose to water and compared it with the doses calculated using the AAPM TG-43 report. The overall combined uncertainty associated with the measurements using Fricke dosimetry was 1.4% for k = 1, which is better than the uncertainties reported in previous studies. These results are promising; hence, the use of Fricke dosimetry to measure the absorbed dose to water as a standard for HDR 192Ir may be possible in the future.

  17. A Feasibility Study of Fricke Dosimetry as an Absorbed Dose to Water Standard for 192Ir HDR Sources

    Science.gov (United States)

    deAlmeida, Carlos Eduardo; Ochoa, Ricardo; de Lima, Marilene Coelho; David, Mariano Gazineu; Pires, Evandro Jesus; Peixoto, José Guilherme; Salata, Camila; Bernal, Mario Antônio

    2014-01-01

    High dose rate brachytherapy (HDR) using 192Ir sources is well accepted as an important treatment option and thus requires an accurate dosimetry standard. However, a dosimetry standard for the direct measurement of the absolute dose to water for this particular source type is currently not available. An improved standard for the absorbed dose to water based on Fricke dosimetry of HDR 192Ir brachytherapy sources is presented in this study. The main goal of this paper is to demonstrate the potential usefulness of the Fricke dosimetry technique for the standardization of the quantity absorbed dose to water for 192Ir sources. A molded, double-walled, spherical vessel for water containing the Fricke solution was constructed based on the Fricke system. The authors measured the absorbed dose to water and compared it with the doses calculated using the AAPM TG-43 report. The overall combined uncertainty associated with the measurements using Fricke dosimetry was 1.4% for k = 1, which is better than the uncertainties reported in previous studies. These results are promising; hence, the use of Fricke dosimetry to measure the absorbed dose to water as a standard for HDR 192Ir may be possible in the future. PMID:25521914

  18. A dosimetric comparison of 169Yb and 192Ir for HDR brachytherapy of the breast, accounting for the effect of finite patient dimensions and tissue inhomogeneities.

    Science.gov (United States)

    Lymperopoulou, G; Papagiannis, P; Angelopoulos, A; Karaiskos, P; Georgiou, E; Baltas, D

    2006-12-01

    Monte Carlo simulation dosimetry is used to compare 169Yb to 192Ir for breast high dose rate (HDR) brachytherapy applications using multiple catheter implants. Results for bare point sources show that while 169Yb delivers a greater dose rate per unit air kerma strength at the radial distance range of interest to brachytherapy in homogeneous water phantoms, it suffers a greater dose rate deficit in missing scatter conditions relative to 192Ir. As a result of these two opposing factors, in the scatter conditions defined by the presence of the lung and the finite patient dimensions in breast brachytherapy the dose distributions calculated in a patient equivalent mathematical phantom by Monte Carlo simulations for the same implant of either 169Yb or 1921r commercially available sources are found comparable. Dose volume histogram results support that 169Yb could be at least as effective as 192Ir delivering the same dose to the lung and slightly reduced dose to the breast skin. The current treatment planning systems' approach of employing dosimetry data precalculated in a homogeneous water phantom of given shape and dimensions, however, is shown to notably overestimate the delivered dose distribution for 169Yb. Especially at the skin and the lung, the treatment planning system dose overestimation is on the order of 15%-30%. These findings do not undermine the potential of 169Yb HDR sources for breast brachytherapy relative to the most commonly used 192Ir HDR sources. They imply, however, that there could be a need for the amendment of dose calculation algorithms employed in clinical treatment planning of particular brachytherapy applications, especially for intermediate photon energy sources such as 169Yb.

  19. HDR {sup 192}Ir source speed measurements using a high speed video camera

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Viana, Rodrigo S. S.; Yoriyaz, Hélio [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Podesta, Mark [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Rubo, Rodrigo A.; Sales, Camila P. de [Hospital das Clínicas da Universidade de São Paulo—HC/FMUSP, São Paulo 05508-000 (Brazil); Reniers, Brigitte [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, Frank, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2015-01-15

    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  20. Stem signal suppression in fiber-coupled Al2O3:C dosimetry for 192Ir brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir; Andersen, Claus Erik; Edmund, J.M.

    2011-01-01

    was adapted for on-line in-vivo dosimetry using fiber-coupled carbon doped aluminum oxide (Al2O3:C). The technique involved a two-channel optical filtration of the radioluminescence (RL) emitted from a pre-irradiated Al2O3:C crystal with enhanced sensitivity. The system responded linearly in the absorbed dose......The stem signal, composed of fluorescence and Čerenkov light, becomes a significant source of uncertainty in fiber-coupled afterloaded brachytherapy dosimetry when the source dwells near the fiber cable but far from the detector. A stem suppression technique originally developed for scintillators...... range 0.05–50 Gy, as needed under high dose rate (HDR) conditions. The dosimeter was irradiated in a water phantom using a 37 GBq 192Ir source at source-to-crystal distances ranging from 0.5 cm to 6.7 cm. For irradiation conditions that generated a stem component in the range 4%–15% in the unfiltered...

  1. Characterization of TLD-100 in powders for dosimetric quality control of {sup 192} Ir sources used in brachytherapy of high dose rate; Caracterizacion de TLD-100 en polvo para control de calidad dosimetrico de fuentes de Ir{sup 192} usadas en braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P

    2007-07-01

    The Secondary Standard Dosimetric at the National Institute of Nuclear Research (ININ) calibrated a lot of powdered TLD-100 (LiF:Mg,Ti) in terms of absorbed dose to water D{sub w} for the energy of: {sup 60}Co, {sup 137C}s, X rays of 250 and 50 kVp. Later on, it is carried out an interpolation of the calibration for the energy of the {sup 192}Ir. This calibration is part of a dosimetric quality control program, to solve the problems of traceability for the measurements carried out by the users of {sup 192}Ir sources employed in the treatments of High Dose Rate Brachytherapy (HDR) at the Mexican Republic. The calibrations of the radiation beams are made with the following protocols: IAEA TRS-398 for the {sup 60}Co for D{sub w}, using a secondary standard ionization chamber PTW N30013 calibrated in D{sub w} by the National Research Council (NRC, Canada). AAPM TG-43 for D{sub w} in terms of the strength kerma Sk, calibrating this last one quantity for the {sup 137}Cs radioactive source, with a well chamber HDR 1000 PLUS traceable to the University of Wisconsin (US). AAPM TG-61 for X ray of 250 and 50 kVp for D{sub w} start to Ka using field standard a Farmer chamber PTW 30001 traceable to K for the Central Laboratory of Electric Industries (CLEI, France). The calibration curves (CC) they built for the response of the powder TLD: R{sub TLD} vs D{sub w}: For the energy of {sup 60}Co, {sup 137}Cs, X rays of 250 and 50 kVp. Fitting them with the least square method weighed by means of a polynomial of second grade that corrects the supra linearity of the response. iii. Each one of the curves was validated with a test by lack of fitting and for the Anderson Darling normality test, using the software MINITAB in both cases. iv. The sensibility factor (F{sub s}) for each energy corresponds to the slope of the CC, v. The F{sub s} for the two {sup 192}Ir sources used are interpolated: one for a Micro Selectron source and the other one a Vari Source source. Finally, a couple of

  2. Effects of Endovascular Brachytherapy with 192Ir Afterloading System on Expression of Type Ⅰ Collagen after Angioplasty

    Institute of Scientific and Technical Information of China (English)

    向定成; 杨传红; 候友贤; 龚志华; 易绍东; 邱建

    2003-01-01

    Objectives To investi-gate the effect and mechanism of endovascularbrachytherapy with 192Ir on expression of type Ⅰ collagen, metalloproteinases - 1 (MMP - 1) and the tissueinhibitor (TIMP- 1 ) after angioplasty. MethodsRestenotic model of domestic microswine was em-ployed and the iliac arteries were randomized to radi-ation group ( n = 12), which were treated with 20 ~ 25Gy of 192Ir, and non - radiation group ( n = 36) afterangioplasty. The target vessels were harvested in theend of 3 months and 6 months after angioplasty. Im-munohistochemistry and in situ hybridization were usedto detect proteins of type Ⅰ collagen, MMP-1 andTIMP- 1, and mRNA expression of type Ⅰ collagen.Results The protein and mRNA of type Ⅰ collagen,the ratios of TIMP-1/MMP-1 were significantlylower iu radiation group than in non- radiation group( P < 0.05 or 0.01 ). The peak of transcription of typeⅠ collagen mRNA was at 6 months and 3 months in non-radiation group and radiation group respectively.Conclusions Endovascular brachytherapy with192Ir might modify the metabolism of extracellular ma-trix after angioplasty by inhibiting the synthesis of typeⅠ collagen and the activities of MMP - 1 and TIMP - 1.

  3. Analysis of the Survival Rate with Cervical Cancer Using 137Cs and 192Ir Aftedoading Brachytherapy

    Institute of Scientific and Technical Information of China (English)

    GuixioZhou; GuoxiongChen; DemeiMa; JianpingSun; LinMa

    2004-01-01

    OBJECTIVE To analyze and compare the survival rate for stages Ⅱ and Ⅲ cervical cancer treated by external irradiation plus 137Cs or 192Ir. METHODS The patients with cervical cancer were treated by external irradiation plus 137Cs (group A, 427 patients) or plus 192Ir (group B, 156 patients). There were 170 stage Ⅱ cases and 413 stage Ⅲ cases. The number of cancer types were as follows: squamous cell carcinoma, 524; adenocarcinoma, 34; and adenosquamous cell carcinoma, 25. The two groups received the same external irradiation using 8 or 10 MV of X-ray. After the whole pelvis received 25-35 Gy, the focus was given a total of 45-55 Gy by four divided fields. Intracavitary irradiation was performed with one fraction of 6-7 Gy in reference dose at A point every week and a total dose of 40-60 Gy with 6-8 fractions for group A; every fraction of 5-6 Gy in reference dose of A point and total dose of 30-42 Gy with 5-7 fractions for group B.RESULTS The 5-year survival rate of stage Ⅱ and Ⅲ, and total were 82.9%, 62.2%, and 67.2% for group A respectively and 85.1%, 61.5% and 69.2% for group B respectively. There were significant differences between stage Ⅱ and Ⅲ in each group (P 0.05). The late complications of the therapy were rectitis and urocystitis and with an incidence rate of 7.3% and 6.3% for group A and 9.6% and 9.0% for group B (P> 0.05). CONCLUSION The long-term survival rate and complications of stages Ⅱ and Ⅲ cervical cancer are similar when treated with external irradiation plus 137Cs or plus 192Ir.

  4. The influence of different 192Ir sources geometries to the energy deposition

    Science.gov (United States)

    Santos, W. S.; Gonalves, P. E.; Belinato, W.; Caldas, L. V. E.; Perini, A. P.; Neves, L. P.

    2016-07-01

    In this paper, various simplifications of the HDR source Varian VariSource Classic model, in which 192Ir as a radionuclide is used, were compared. These simplifications were carried out by Monte Carlo simulations, using the MCNPX 2.7.0 code. The different sources were compared through a distribution of energy deposition in a water phantom. Our results indicated that small simplifications will present no influence on the source response, and the removal of the entire capsule surrounding the radionuclide will present a difference of just 0.53% in the final response.

  5. The influence of different {sup 192}Ir sources geometries to the energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Paulo Eduardo; Perini, Ana Paula; Neves, Lucio Pereira, E-mail: lucio.neves@ufu.br [Universidade Federal de Uberlandia (INFIS/UFU), MG (Brazil). Instituto de Fisica; Santos, William de Souza; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Belinato, Walmir [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Fisica

    2015-07-01

    In this paper, various simplifications of the HDR source Varian VariSource Classic model, in which {sup 192}Ir as a radionuclide is used, were compared. These simplifications were carried out by the simulation of Monte Carlo, using the MCNPX code. The different sources were compared through a distribution of energy deposition in a water phantom. Our results indicated that small simplifications will present no influence on the source response, and the removal of the entire capsule surrounding the radionuclide will present a difference of just 0.51% in the final response. (author)

  6. In vivo dosimetry in the urethra using alanine/ESR during (192)Ir HDR brachytherapy of prostate cancer--a phantom study.

    Science.gov (United States)

    Anton, Mathias; Wagner, Daniela; Selbach, Hans-Joachim; Hackel, Thomas; Hermann, Robert Michael; Hess, Clemens Friedrich; Vorwerk, Hilke

    2009-05-07

    A phantom study for dosimetry in the urethra using alanine/ESR during (192)Ir HDR brachytherapy of prostate cancer is presented. The measurement method of the secondary standard of the Physikalisch-Technische Bundesanstalt had to be slightly modified in order to be able to measure inside a Foley catheter. The absorbed dose to water response of the alanine dosimetry system to (192)Ir was determined with a reproducibility of 1.8% relative to (60)Co. The resulting uncertainty for measurements inside the urethra was estimated to be 3.6%, excluding the uncertainty of the dose rate constant Lambda. The applied dose calculated by a treatment planning system is compared to the measured dose for a small series of (192)Ir HDR irradiations in a gel phantom. The differences between the measured and applied dose are well within the limits of uncertainty. Therefore, the method is considered to be suitable for measurements in vivo.

  7. In vivo dosimetry in the urethra using alanine/ESR during 192Ir HDR brachytherapy of prostate cancer—a phantom study

    Science.gov (United States)

    Anton, Mathias; Wagner, Daniela; Selbach, Hans-Joachim; Hackel, Thomas; Hermann, Robert Michael; Hess, Clemens Friedrich; Vorwerk, Hilke

    2009-05-01

    A phantom study for dosimetry in the urethra using alanine/ESR during 192Ir HDR brachytherapy of prostate cancer is presented. The measurement method of the secondary standard of the Physikalisch-Technische Bundesanstalt had to be slightly modified in order to be able to measure inside a Foley catheter. The absorbed dose to water response of the alanine dosimetry system to 192Ir was determined with a reproducibility of 1.8% relative to 60Co. The resulting uncertainty for measurements inside the urethra was estimated to be 3.6%, excluding the uncertainty of the dose rate constant Λ. The applied dose calculated by a treatment planning system is compared to the measured dose for a small series of 192Ir HDR irradiations in a gel phantom. The differences between the measured and applied dose are well within the limits of uncertainty. Therefore, the method is considered to be suitable for measurements in vivo.

  8. In vivo dosimetry in the urethra using alanine/ESR during {sup 192}Ir HDR brachytherapy of prostate cancer-a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Anton, Mathias; Selbach, Hans-Joachim; Hackel, Thomas [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Wagner, Daniela; Hess, Clemens Friedrich; Vorwerk, Hilke [Department of Radiotherapy and Radiooncology, University Hospital Goettingen, Goettingen (Germany); Hermann, Robert Michael [Zentrum fuer Strahlentherapie und Radioonkologie, Bremen (Germany)], E-mail: mathias.anton@ptb.de

    2009-05-07

    A phantom study for dosimetry in the urethra using alanine/ESR during {sup 192}Ir HDR brachytherapy of prostate cancer is presented. The measurement method of the secondary standard of the Physikalisch-Technische Bundesanstalt had to be slightly modified in order to be able to measure inside a Foley catheter. The absorbed dose to water response of the alanine dosimetry system to {sup 192}Ir was determined with a reproducibility of 1.8% relative to {sup 60}Co. The resulting uncertainty for measurements inside the urethra was estimated to be 3.6%, excluding the uncertainty of the dose rate constant {lambda}. The applied dose calculated by a treatment planning system is compared to the measured dose for a small series of {sup 192}Ir HDR irradiations in a gel phantom. The differences between the measured and applied dose are well within the limits of uncertainty. Therefore, the method is considered to be suitable for measurements in vivo.

  9. [Risk factors of late complications after interstitial 192Ir brachytherapy in cancers of the oral cavity].

    Science.gov (United States)

    Peiffert, D

    1997-01-01

    Brachytherapy has confirmed its prevailing role in conservative treatment of oral cavity carcinomas. To describe late toxicity in long-term surviving patients, comparisons with other series are necessary. Study of series of patients implanted for floor of the mouth or mobile tongue shows the need for more detailed data. Dental prophylaxy and lead protection of the mandibule, good indications and techniques of brachytherapy are necessary to avoid late complications. Some treatment factors have proved to be of good prognosis for late complications through multivariate analysis of large series treated with lr 192 wires, using the Paris system, eg, dose rate lower than 0.5 or 0.7 Gy/h, intersource spacing smaller than 1.2 or 1.5 cm, treated surface less than 12 cm2, lineic activity less than 1.5 mCi/cm, less than 1 cm diameter hyperdose, and use of mandibular lead protections. Tumor volume and location to the floor of mouth lead to higher risk of complications. Knowledge of treatment-related factors is important, with the development of new afterloading projectors allowing to control the dose rate and correct small inhomogeneities. High-dose rate exclusive brachytherapy is not recommended. More precise and reproducible classification should be used to report complications in series leading to publications in the future, thus allowing to compare results, reduce complication rates and improve the quality of life.

  10. The mean photon energy anti E{sub F} at the point of measurement determines the detector-specific radiation quality correction factor k{sub Q,M} in {sup 192}Ir brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chofor, Ndimofor; Harder, Dietrich; Selbach, Hans-Joachim; Poppe, Bjoern [University of Oldenburg and Pius-Hospital Oldenburg (Germany). Medical Radiation Physics Group

    2016-11-01

    The application of various radiation detectors for brachytherapy dosimetry has motivated this study of the energy dependence of radiation quality correction factor k{sub Q,M}, the quotient of the detector responses under calibration conditions at a {sup 60}Co unit and under the given non-reference conditions at the point of measurement, M, occurring in photon brachytherapy. The investigated detectors comprise TLD, radiochromic film, ESR, Si diode, plastic scintillator and diamond crystal detectors as well as ionization chambers of various sizes, whose measured response-energy relationships, taken from the literature, served as input data. Brachytherapy photon fields were Monte-Carlo simulated for an ideal isotropic {sup 192}Ir point source, a model spherical {sup 192}Ir source with steel encapsulation and a commercial HDR GammaMed Plus source. The radial source distance was varied within cylindrical water phantoms with outer radii ranging from 10 to 30 cm and heights from 20 to 60 cm. By application of this semiempirical method - originally developed for teletherapy dosimetry - it has been shown that factor k{sub Q,M} is closely correlated with a single variable, the fluence-weighted mean photon energy anti E{sub F} at the point of measurement. The radial profiles of anti E{sub F} obtained with either the commercial {sup 192}Ir source or the two simplified source variants show little variation. The observed correlations between parameters k{sub Q,M} and anti E{sub F} are represented by fitting formulae for all investigated detectors, and further variation of the detector type is foreseen. The herewith established close correlation of radiation quality correction factor k{sub Q,M} with local mean photon energy anti E{sub F} can be regarded as a simple regularity, facilitating the practical application of correction factor k{sub Q,M} for in-phantom dosimetry around {sup 192}Ir brachytherapy sources. anti E{sub F} values can be assessed by Monte Carlo simulation or

  11. 国产血管内192Ir线源的放射剂量测定%Dosimetry of a China-made 192Ir wire source

    Institute of Scientific and Technical Information of China (English)

    何昆仑; 王所亭; 高焱章; 周凯欣; 冯宁远; 邱学军

    2001-01-01

    目的对国产血管内192Ir线源的剂量分布进行评价,为动物实验和临床应用提供依据。方法采用Kodak X-omat V慢感光胶片,从平行和垂直于放射源长轴方向进行测量,径向测量时间为25、45、65和82 s,轴向测定时间为25 s,同时进行标准剂量的标定,通过胶片自动分析测量系统分析剂量分布和吸收剂量。参考AAPM TG No.60报告,采用Monte Carlo方法对放射源的辐射剂量进行理论计算,同时与采用AAPM TG No.43报告计算方法进行比较。结果国产血管内192Ir线源具有良好的剂量分布。AAPM TG No.43报告计算方法比Monte Carlo方法高估32%的辐射剂量。结论国产192Ir线源作为血管内放射源是可行的,采用慢感光胶片测定放射源的剂量分布是一种有效手段。%Objective To evaluate the dose releasing rate and the homogeneity of dose distribution of the Chine-made intravascular 192Ir wire source and to provide experimental data of animal study and clinical use. Methods Dosimetry of the 192Ir wire source was measured by Kodak X-omat V film in differents directions and in different exposure lengths.Dose releasing rate of our 192Ir wire source was calculated according to AAPM TG No.60 and Monte Carlo model,and compared with the results by traditional brachytherapy planning system(AAPM TG No.43) Results 192Ir wire source provided with a well-distributed dose around the source,no striking asymmetry was observed.Thirty two percent of dose rate was overestimated by traditional brachytherapy planning system(AAPM TG No.43)comparing with Monte Carlo method. Conclusions The China-made 192Ir wire source is reliable for intravascular radiation.It is an alternative method to measure the dose distribution with Kodak X-omat V film.The dose rate of 192Ir wire source can be estimated by traditional brachytherapy planning system (AAPM TG No.43) and Monte Carlo method.This study may provide a fundation for practicing

  12. Interstitial brachytherapy with 192-IR in treatment of recurrent malignant primary brain tumors. Braquiterapia intersticial con iridio-192 en el tratamiento de recidivas de tumores cerebrales tras cirugia y radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Cardenes, R.; Martinez, R.; Victoria, C.; Nuez, L.; Clavo, B.; Sancedo, G. (Clinica Puerta de Hierro. Madrid (Spain))

    1994-01-01

    Seven patients with recurrent malignant primary brain tumors after surgery and radiation therapy were treated at the Clinica Puerta de Hierro (Madrid) by interstitial brachytherapy with 192-Ir sources. Implantations were performed using computerized tomography and dose prescription were determined following the Paris system rules for interstitial implants. The means dose deliberated was 50 to 65 Gy to the reference isodoses. At the last follow-up all patients except for one are alive and without evidence of progression of the disease. (Author) 35 refs.

  13. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters; Proposta de um sistema postal para a calibracao de fontes de {sup 192} Ir, utilizadas em braquiterapia de alta taxa de dose, com dosimetros termoluminescentes de LiF: Mn: Ti

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V. [Instituto de Radioprotecao e Dosimetria. CNEN Caixa Postal 37750, 22780-160, Rio de Janeiro (Brazil)

    1998-12-31

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

  14. SU-E-T-580: On the Significance of Model Based Dosimetry for Breast and Head and Neck 192Ir HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Peppa, V; Pappas, E; Pantelis, E; Papagiannis, P [Medical Physics Laboratory, Medical School, University of Athens, Athens (Greece); Major, T; Polgar, C [National Institute of Oncology, Budapest (Hungary)

    2015-06-15

    Purpose: To assess the dosimetric and radiobiological differences between TG43-based and model-based dosimetry in the treatment planning of {sup 192}Ir HDR brachytherapy for breast and head and neck cancer. Methods: Two cohorts of 57 Accelerated Partial Breast Irradiation (APBI) and 22 head and neck (H&N) patients with oral cavity carcinoma were studied. Dosimetry for the treatment plans was performed using the TG43 algorithm of the Oncentra Brachy v4.4 treatment planning system (TPS). Corresponding Monte Carlo (MC) simulations were performed using MCNP6 with input files automatically prepared by the BrachyGuide software tool from DICOM RT plan data. TG43 and MC data were compared in terms of % dose differences, Dose Volume Histograms (DVHs) and related indices of clinical interest for the Planning Target Volume (PTV) and the Organs-At-Risk (OARs). A radiobiological analysis was also performed using the Equivalent Uniform Dose (EUD), mean survival fraction (S) and Tumor Control Probability (TCP) for the PTV, and the Normal Tissue Control Probability (N TCP) and the generalized EUD (gEUD) for the OARs. Significance testing of the observed differences performed using the Wilcoxon paired sample test. Results: Differences between TG43 and MC DVH indices, associated with the increased corresponding local % dose differences observed, were statistically significant. This is mainly attributed to their consistency however, since TG43 agrees closely with MC for the majority of DVH and radiobiological parameters in both patient cohorts. Differences varied considerably among patients only for the ipsilateral lung and ribs in the APBI cohort, with a strong correlation to target location. Conclusion: While the consistency and magnitude of differences in the majority of clinically relevant DVH indices imply that no change is needed in the treatment planning practice, individualized dosimetry improves accuracy and addresses instances of inter-patient variability observed. Research

  15. Long-term follow-up after accidental gamma irradiation from a {sup 192}Ir source in Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Mollah, A.S.; Begum, A.; Begum, R. [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

    2006-07-01

    A industrial radiographer was accidentally over -exposed to high dose of ionizing radiation from an {sup 192}Ir source pellet during radiograph y of weld-joints in gas pipe-lines on June 10, 1985 in Bangladesh. The source, housed in a portable exposure assembly, had an activity of about 1850 GBq. A guide -tube was used to control the transfer of the source from safe storage position to the exposure position and vice versa. For radiography, the ti p of the guide tube was to be fixed to the weld -joint while the source was cranked to the exposure position. Following the elapse of the preset exposure time the source had to be cranked back to the safe stor age position. This procedure was to be repeated for each radiographic exposure. Symptoms of high radiation exposure occurred immediately after the accident and skin erythema developed leading to progressive tissue deteriorations. Biological effects such as mild vomiting, malaise, nausea and diarrhea occurred within a short period after the accident. Skin erythema, swelling and tenderness of the palmar surfaces and the tips of the thumbs, index fingers and middle fingers of the both hands accompanied by severe pain and inflammation developed within 7 days of the mishap. The inflammatory changes characterized by redness and bullae spread over the affected fingers with severe pain and agony within a few days. The finger -tips developed abscesses with enormous pus formation and the affected finger nails fell off. He also developed toothache. At this stage a medical practitioner made some surgical dressings and prescribed antibiotics. During the first six months the most serious health disorder was local necroses of the skin and the deep layers of the palmar side of the affected fingers with sharply delineated injuries. The clinical findings were consistent with those reported elsewhere under similar accident conditions. The consequences of this over-exposure are being followed up to assess the long-term effects of

  16. Study of two different radioactive sources for prostate brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Neves, Lucio; Perini, Ana Paula [Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG (Brazil); Souza Santos, William de; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear, IPENCNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil); Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA (Brazil)

    2015-07-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a {sup 192}Ir and a {sup 125}I radioactive sources. The {sup 192}Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The {sup 125}I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of {sup 125}I and one of {sup 192}Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the {sup 192}Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the {sup 125}I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  17. Intercomparison of calibration procedures of high dose rate {sup 192} Ir sources in Brazil and a proposal of a new methodology; Intercomparacao de procedimientos de calibracao de fontes de {sup 192} Ir de alta taxa de dose no Brasil e proposta de uma nova metodologia

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, M.H.; Almeida, C.E. de [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes IRD/CNEN. Caixa Postal 37750 CEP 22780-160 Rio de Janeiro (Brazil)

    1998-12-31

    The objective of this paper is to report the results of an intercomparison of the calibration procedures for {sup 192} Ir sources presently in use in Brazil and to proposal a calibration procedure to derive the N{sub k} for a Farmer type ionization chamber for {sup 192} Ir energy by interpolating from a {sup 60} Co gamma-rays and 250 kV x-rays calibration factors. the intercomparison results were all within {+-} 3.0 % except one case where 4.6 % was observed and latter identified as a problem with N-k value for X-rays. The method proposed by the present work make possible the improvement of the metrological coherence among the calibration laboratories and their users once the N{sub k} values could then provided by any of the members of SSDL network. (Author)

  18. 192Ir intraluminal brachytherapy for the prevention of urethral re-stricture%192Ir腔内放疗预防男性尿道内切开术后再狭窄临床分析

    Institute of Scientific and Technical Information of China (English)

    马缠过; 郭辉; 杜春; 杨克强

    2008-01-01

    目的 探讨和评价尿道内切开或(和)瘢痕电切术后,192Ir腔内放疗预防男性尿道再狭窄的安全性和临床疗效.方法 2年余内共治疗48例,其中年龄18~81岁,狭窄长度为0.5~5.5cm,90%狭窄长度在3.0 cm以内.外伤性狭窄23例、前列腺增生术后狭窄19例、不明原因狭窄6例.经尿道造影或内窥镜检查确诊.26例首次治疗,22例再次治疗(首次治疗属非放疗疗法).放疗处方剂量为14~18 Gy.结果 48例平均随访10个月,有效率98%.治疗后无复发,无明显副作用.47例排尿均通畅,最大尿流率13.9~36.4(19.2±10.3)ml/s;1例出现轻度尿失禁,可能与多次扩张损伤尿道括约肌有关.结论 尿道内切开或(和)瘢痕电切术后腔内放疗有助于预防尿道再狭窄,明显优于现有其他治疗方法,且副作用小、简便易行.%Objective To evaluate the safety and efficacy of 192Ir intraluminal brachytherapy for the prevention of urethral re-stricture after transurethral incision or transurethral resection of scar. Methods From Mar. 2004 to Jun. 2006,48 patients aging 18-81 years were treated by 192Ir intraluminal brachytherapy. The length of stricture(0.5-5.5 era) was≤3.0 cm in 90% of the patients. The stricture was caused by trauma in 23 patients and prostate hyperplasia operation in 19 patients. The cause of remaining 6 patients was unclear. All patients were diagnosed by urethra photograph or endoscopy. Radiotherapy was the initial treatment in 26 patients and the second time treatment in 22. The irradiation dose was from 14 Gy to 18 Gy.Results The median follow up was 10 months,and the total response rate was 98%. Only one patient recurred and received transurethral incision again. The uresis was fluency in 47 patients and the maximum flow rate was 13.9-36.4(19.2±10.3) ml/s. No secondary urethral bleeding or urethral cancer was observed.Conclusions Being a safe and feasible treatment, ,192Ir intraluminal brachytherapy following transurethral

  19. Evaluation of 101Rh as a brachytherapy source

    Science.gov (United States)

    Ghorbani, Mahdi; Meigooni, Ali Soleimani

    2015-01-01

    Purpose Recently a number of hypothetical sources have been proposed and evaluated for use in brachytherapy. In the present study, a hypothetical 101Rh source with mean photon energy of 121.5 keV and half-life of 3.3 years, has been evaluated as an alternative to the existing high-dose-rate (HDR) sources. Dosimetric characteristics of this source model have been determined following the recommendation of the Task Group 43 (TG-43) of the American Association of the Physicist in Medicine (AAPM), and the results are compared with the published data for 57Co source and Flexisource 192Ir sources with similar geometries. Material and methods MCNPX Monte Carlo code was used for simulation of the 101Rh hypothetical HDR source design. Geometric design of this hypothetical source was considered to be similar to that of Flexisource 192Ir source. Task group No. 43 dosimetric parameters, including air kerma strength per mCi, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated for the 101Rh source through simulations. Results Air kerma strength per activity and dose rate constant for the hypothetical 101Rh source were 1.09 ± 0.01 U/mCi and 1.18 ± 0.08 cGy/(h.U), respectively. At distances beyond 1.0 cm in phantom, radial dose function for the hypothetical 101Rh source is higher than that of 192Ir. It has also similar 2D anisotropy functions to the Flexisource 192Ir source. Conclusions 101Rh is proposed as an alternative to the existing HDR sources for use in brachytherapy. This source provides medium energy photons, relatively long half-life, higher dose rate constant and radial dose function, and similar 2D anisotropy function to the Flexisource 192Ir HDR source design. The longer half-life of the source reduces the frequency of the source exchange for the clinical environment. PMID:26034499

  20. Source geometry factors for HDR ¹⁹²Ir brachytherapy secondary standard well-type ionization chamber calibrations.

    Science.gov (United States)

    Shipley, D R; Sander, T; Nutbrown, R F

    2015-03-21

    Well-type ionization chambers are used for measuring the source strength of radioactive brachytherapy sources before clinical use. Initially, the well chambers are calibrated against a suitable national standard. For high dose rate (HDR) (192)Ir, this calibration is usually a two-step process. Firstly, the calibration source is traceably calibrated against an air kerma primary standard in terms of either reference air kerma rate or air kerma strength. The calibrated (192)Ir source is then used to calibrate the secondary standard well-type ionization chamber. Calibration laboratories are usually only equipped with one type of HDR (192)Ir source. If the clinical source type is different from that used for the calibration of the well chamber at the standards laboratory, a source geometry factor, k(sg), is required to correct the calibration coefficient for any change of the well chamber response due to geometric differences between the sources. In this work we present source geometry factors for six different HDR (192)Ir brachytherapy sources which have been determined using Monte Carlo techniques for a specific ionization chamber, the Standard Imaging HDR 1000 Plus well chamber with a type 70010 HDR iridium source holder. The calculated correction factors were normalized to the old and new type of calibration source used at the National Physical Laboratory. With the old Nucletron microSelectron-v1 (classic) HDR (192)Ir calibration source, ksg was found to be in the range 0.983 to 0.999 and with the new Isodose Control HDR (192)Ir Flexisource k(sg) was found to be in the range 0.987 to 1.004 with a relative uncertainty of 0.4% (k = 2). Source geometry factors for different combinations of calibration sources, clinical sources, well chambers and associated source holders, can be calculated with the formalism discussed in this paper.

  1. Effect of tissue composition on dose distribution in brachytherapy with various photon emitting sources

    Science.gov (United States)

    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

  2. Calibration of TLD-100 powder for energies of {sup 60} Co, {sup 137} Cs, {sup 192} Ir and RX of 250, 50 kV{sub p} in absorbed dose in water with dosimetric quality control purposes for brachytherapy of high dose rate; Calibracion de polvo TLD-100 para energias de {sup 60} Co, {sup 137} Cs, {sup 192} Ir y RX de 250, 50 kVp en dosis absorbida en agua con fines de control de calidad dosimetrico para braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P. [Programa de Maestria en Fisica Medica, Universidad Autonoma del Estado de Mexico, Paseo Tollocan S/N, esquina con Jesus Carranza, Colonia Moderna de la Cruz, 50180 Toluca, Edo. de Mexico (Mexico); Alvarez R, J.T. [Laboratorio Secundario de Calibracion Dosimetrica LSCD, Departamento de Metrologia, ININ, Carretera Federal Mexico Toluca S/N, La Marquesa, 52750 Ocoyoacac, Edo. de Mexico (Mexico)

    2006-07-01

    To help solve the traceability and quality control dosimetric problems for the users of {sup 192} Ir sources in the Mexican Republic, the Secondary Standard Dosimetric Laboratory at ININ to calibrated a batch of powder TLD- 100 (LiF: Mg,Ti) in terms of absorbed dose to water D{sub w} for the following radiation sources: {sup 60} Co, {sup 137C}s and RX 250 and 50 k Vp. Later on, the calibration is interpolated to obtain the {sup 192} Ir. The calibration radiation field is carried out with the following protocols: For the {sup 60} Co, IAEA TRS 398 protocol employing a secondary standard Farmer chamber PTW N30013, calibrated on D{sub w} at the NRC (Canada). For {sup 137} Cs the AAPM TG 43 protocol is used, in terms of air kerma strength S{sub k} determined by the air kerma K{sub a}, measured with a secondary standard chamber type thimble NE2611 traceable to the NIST (USA). For Rays X 250 and 50 k Vp, the protocol AAPM TG 61 using a tertiary standard Farmer chamber PTW 30001, with traceability to the LCIE (France) on air kerma K{sub a}. The calibration curves are built for the TLD response R{sub TLD} vs D{sub w}, they are fitted by means of a least squares fit technique with a second degree polynomial that corrects the supra linearity response. The curves are validated by the lack of fit test, and the Anderson Darling normality test. Later on, the sensibility factors are interpolated for the sources of {sup 192} Ir: Micro Selectron and Vari Source. Two capsules are sent to two hospitals to verify a nominal D{sub w} = 2 Gy, in the first one an underestimate of the D{sub w} is obtained, and in other one an overestimation is presented. Finally, the expanded uncertainty associated to D{sub w} and the F{sub s} are calculated. (Author)

  3. Brachytherapy source characterization for improved dose calculations using primary and scatter dose separation.

    Science.gov (United States)

    Russell, Kellie R; Tedgren, Asa K Carlsson; Ahnesjö, Anders

    2005-09-01

    In brachytherapy, tissue heterogeneities, source shielding, and finite patient/phantom extensions affect both the primary and scatter dose distributions. The primary dose is, due to the short range of secondary electrons, dependent only on the distribution of material located on the ray line between the source and dose deposition site. The scatter dose depends on both the direct irradiation pattern and the distribution of material in a large volume surrounding the point of interest, i.e., a much larger volume must be included in calculations to integrate many small dose contributions. It is therefore of interest to consider different methods for the primary and the scatter dose calculation to improve calculation accuracy with limited computer resources. The algorithms in present clinical use ignore these effects causing systematic dose errors in brachytherapy treatment planning. In this work we review a primary and scatter dose separation formalism (PSS) for brachytherapy source characterization to support separate calculation of the primary and scatter dose contributions. We show how the resulting source characterization data can be used to drive more accurate dose calculations using collapsed cone superposition for scatter dose calculations. Two types of source characterization data paths are used: a direct Monte Carlo simulation in water phantoms with subsequent parameterization of the results, and an alternative data path built on processing of AAPM TG43 formatted data to provide similar parameter sets. The latter path is motivated of the large amounts of data already existing in the TG43 format. We demonstrate the PSS methods using both data paths for a clinical 192Ir source. Results are shown for two geometries: a finite but homogeneous water phantom, and a half-slab consisting of water and air. The dose distributions are compared to results from full Monte Carlo simulations and we show significant improvement in scatter dose calculations when the collapsed

  4. Brachytherapy

    Science.gov (United States)

    ... radiation sources used in brachytherapy are: Iodine, Palladium, Cesium and Iridium. In all cases of brachytherapy, the ... is a highly trained physician specializing in treating cancer with radiotherapy . top of page Is there any ...

  5. SU-F-BRA-05: Utility of the Combined Use of Two Types of HDR Sources with the Direction Modulation Brachytherapy (DMBT) Tandem Applicator for Cervical Cancer Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, H; Soliman, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, U of T, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States); Scanderbeg, D [UCSD Medical Center, La Jolla, CA (United States)

    2015-06-15

    Purpose: To maximize the dose to HRCTV while minimizing dose to the OARs, the combination of two HDR brachytherapy sources, 192-Ir and 169-Yb, used in combination with the recently-proposed novel direction modulated brachytherapy (DMBT) tandem applicator were examined. Methods: The DMBT tandem, made from nonmagnetic tungsten-alloy rod, with diameter of 5.4mm, has 6 symmetric peripheral holes of 1.3mm diameter. The 0.3mm thick bio-compatible plastic tubing wraps the tandem. MCNPX v.2.6 was used to simulate the mHDR 192-Ir V2 and 4140 HDR 169-Yb sources inside the DMBT applicator. Thought was by combining the higher energy 192-Ir (380keV) and lower energy 169-Yb (92.7keV) sources could create unprecedented level of dose conformality when combined with the high-degree intensity modulation capable DMBT tandem applicator. 3D dose matrices, with 1 mm3 resolution, were imported into an in-house-coded inverse optimization planning system to evaluate plan quality of 19 clinical patient cases. Prescription dose was 15Gy. All plans were normalized to receive the same HRCTV D90. Results: Generally, the use of dual sources produced better plans than using either of the sources alone, with significantly better performance in some patients. The mean D2cc for bladder, rectum, and sigmoid were 11.65±2.30Gy, 7.47±3.05Gy, and 9.84±2.48Gy for 192-Ir-only, respectively. For 169 -Yb-only, they were 11.67±2.26Gy, 7.44±3.02Gy, and 9.83±2.38Gy, respectively. The corresponding data for the dual sources were 11.51±2.24Gy, 7.30±3.00Gy, and 9.68 ±2.39Gy, respectively. The HRCTV D98 and V100 were 16.37±1.86Gy and 97.37±1.92Gy for Ir-192-only, respectively. For 169-Yb-only, they were 16.43±1.86Gy, and 97.51±1.91Gy, respectively. For the dual source, they were 16.42±1.87Gy and 97.47±1.93Gy, respectively. Conclusion: The plan quality improves, in some cases quite significantly, for when dual 192-Ir and 169-Yb sources are used in combination with highly intensity modulation capable

  6. Investigations into the Optimization of Multi-Source Strength Brachytherapy Treatment Procedures

    Energy Technology Data Exchange (ETDEWEB)

    D. L. Henderson; S. Yoo; B.R. Thomadsen

    2002-09-30

    The goal of this project is to investigate the use of multi-strength and multi-specie radioactive sources in permanent prostate implant brachytherapy. In order to fulfill the requirement for an optimal dose distribution, the prescribed dose should be delivered to the target in a nearly uniform dose distribution while simultaneously sparing sensitive structures. The treatment plan should use a small number of needles and sources while satisfying the treatment requirements. The hypothesis for the use of multi-strength and/or multi-specie sources is that a better treatment plan using fewer sources and needles could be obtained than by treatment plans using single-strength sources could reduce the overall number of sources used for treatment. We employ a recently developed greedy algorithm based on the adjoint concept as the optimization search engine. The algorithm utilizes and ''adjoint ratio'', which provides a means of ranking source positions, as the pseudo-objective function. It ha s been shown that the greedy algorithm can solve the optimization problem efficiently and arrives at a clinically acceptable solution in less than 10 seconds. Our study was inclusive, that is there was no combination of sources that clearly stood out from the others and could therefore be considered the preferred set of sources for treatment planning. Source strengths of 0.2 mCi (low), 0.4 mCi (medium), and 0.6 mCi (high) of {sup 125}I in four different combinations were used for the multi-strength source study. The combination of high- and medium-strength sources achieved a more uniform target dose distribution due to few source implants whereas the combination of low-and medium-strength sources achieved better sparing of sensitive tissues including that of the single-strength 0.4 mCi base case. {sup 125}I at 0.4 mCi and {sup 192}Ir at 0.12 mCi and 0.25 mCi source strengths were used for the multi-specie source study. This study also proved inconclusive , Treatment

  7. Balloon-based adjuvant radiotherapy in breast cancer: comparison between 99mTc and HDR 192Ir*

    Science.gov (United States)

    de Campos, Tarcísio Passos Ribeiro; de Lima, Carla Flavia; Cuperschmid, Ethel Mizrahy

    2016-01-01

    Objective To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR) 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice. PMID:27141131

  8. Balloon-based adjuvant radiotherapy in breast cancer: comparison between {sup 99m}Tc and HDR {sup 192}Ir

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Tarcisio Passos Ribeiro de; Lima, Carla Flavia de; Cuperschmid, Ethel Mizrahy, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2016-03-15

    Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with {sup 99m}Tc and balloon brachytherapy with high-dose-rate (HDR) {sup 192}Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and methods: simulations of implants with {sup 99m}Tc-filled and HDR {sup 192}Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: the {sup 99m}Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h{sup -1}.mCi{sup -1} and 0.190 cGyh{sup -1} at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh{sup -1}.mCi{sup -1}, respectively, for the HDR {sup 192}Ir balloon. An exposure time of 24 hours was required for the {sup 99m}Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR {sup 192}Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: temporary {sup 99m}Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR {sup 192}Ir balloon implantation, which is the current standard in clinical practice. (author)

  9. Application of the Cavity theory in the calibration of the powder TLD-100 for energies of {sup 60} Co, {sup 137} Cs, {sup 192} Ir and RX 50, 250 k Vp; Aplicacion de la Teoria de la Cavidad en la calibracion de polvo TLD-100 para energias de {sup 60} Co, {sup 137} Cs, {sup 192} Ir y RX 50, 250 kVp

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P. [UAEM, Programa de Maestria en Fisica Medica, 50180, Toluca, Estado de Mexico (Mexico); Alvarez R, J.T. [ININ, 52750, Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: sandraplc_04@yahoo.com.mx

    2006-07-01

    A powder lot TLD-100 (LiF:Mg,Ti) in absorbed dose terms in water D{sub w} for the following radiation sources: {sup 60} Co, {sup 137} Cs and RX 50 and 250 k Vp is calibrated; to continuation is made a lineal interpolation of the TLD response in function of the effective energy of the sources to calibrate a source of {sup 192} Ir. The calibration of those fields in D{sub w} are carried out with aid of the Bragg-Gray cavity theory, the one which finds implicit in the following protocols: IAEA-TRS 398 for the {sup 60} Co and the AAPM TG61 for X Rays of 50 and 250 k Vp. Additionally the AAPM protocol TG43 to determine the D{sub w} in function of the kerma intensity S{sub k} in the case of the {sup 137} Cs is used. The calibration curves for the response of the TLD-100 R{sub TLD} vs D{sub w}, corresponding to each one of the sources already mentioned are constructed. The R{sub TLD} vs D{sub w} by least heavy square by means of a second order polynomial that corrects the supralineality of the response is adjusted. The curves are validated by lack of LOF adjustment and by the Anderson Darling normality test. Later the factors of sensitivity (F{sub s}) for the sources of {sup 192} Ir: Micro Selectron and Vari Source are interpolated, used respectively in the A and B hospitals for treatments of brachytherapy of high dose rate (HDR), the expanded uncertainties associated to the D{sub w} and F{sub s} are also determined. Finally, an acrylic phantom and a couple of capsules are already sent to the hospitals mentioned, to verify a nominal D{sub w} of 2 Gy, in a case an underestimate in 5.5% in the imparted D{sub w} and in other an overestimation in a range of -1.5 to -8.0% was obtained. The obtained results in this work establish the bases for the development of a national dosimetric quality control program for brachytherapy of HDR with sources of {sup 192} Ir. (Author)

  10. 南京"5.7"192Ir源放射事故患者的营养治疗%Nutrition treatment scheme for a patient exposed to Nanjing "5.7" 192Ir source accident

    Institute of Scientific and Technical Information of China (English)

    陈学英; 刘玉龙; 王优优; 蔡梅芝; 黄威威; 洪秀秀; 赵斯迪

    2016-01-01

    目的 通过对南京“5.7”192Ir源放射事故患者全程救治中的营养治疗,探讨放射损伤患者的营养治疗方案.方法 在不同救治阶段,对患者进行膳食调查和监测相关营养指标包括体重、体质量指数(BMI)、血常规、血生化指标等,并使用代谢车测定患者静息能量消耗值,为患者制订不同的营养治疗方案.结果 患者入院时(受照后第5天)体重42.5 kg,受照后第172天(首次植皮术后)下降至最低为36 kg,此后逐渐回升,出院时(受照后第383天)体重基本恢复.血红蛋白入院时正常为135 g/L,受照后第172天降至最低为54 g/L,出院时恢复正常;淋巴细胞入院时偏低为0.5×109/L,受照后第58天恢复正常,受照后第172天降至最低为0.4 × 109/L,出院时恢复正常.血清白蛋白入院时正常为41.2 g/L,受照后第172天降到最低为25.3 g/L,出院时恢复正常;血清前白蛋白入院时正常为0.22 g/L,受照第248天降至最低为0.04 g/L,出院时基本恢复正常为0.17 g/L.肝功能指标入院时正常,胆红素指标略偏高,进行“全合一”肠外营养后约2.5个月后,肝功能指标和胆红素指标均逐渐升高,经调整营养治疗方案及保肝利胆等治疗后逐渐恢复正常.受照后第294、308和342天使用代谢车测得患者的静息能量消耗值,据此确定患者当日热能需要量.结论 合理营养治疗可以有效改善放射损伤患者的全身营养状况及临床疗效,是放射损伤临床救治的关键手段之一.%Objective To provide nutritional supportive scheme for patients with radiation injury through the treatment of the one exposed to Nanjing 192Ir source accident.Methods The reasonable nutrition treatment scheme was made on the basis of dietary survey and nutritional index monitoring during clinical stages of the patient,including body weight,body mass index(BMI),biochemical indexes,electrolyte,etc.,as well as metabolic cart determination of resting energy

  11. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the VSL and the BIPM

    DEFF Research Database (Denmark)

    Alvarez, J.T.; De Pooter, J.A.; Andersen, Claus E.

    2014-01-01

    An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate brachytherapy sources of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the VSL in November 2009. The comparison resu...

  12. Experimental determination of the energy response of alanine pellets in the high dose rate 192Ir spectrum

    Science.gov (United States)

    Schaeken, B.; Cuypers, R.; Goossens, J.; Van den Weyngaert, D.; Verellen, D.

    2011-10-01

    An experimental determination of the energy correction factor for alanine/paraffin pellets in the 192Ir spectrum at varying distances from the source is presented. Alanine dosimeters were irradiated in water under full scatter conditions with a high dose rate (HDR) 192Ir source (Flexisource), using a dedicated holder. Up to six line sources (catheters) fit in a regular pattern at fixed radial distances from the holder axis, the alanine detector being placed at the centre of the holder. The HDR source was stepping every 0.5 cm within a trocar needle within ± 3.0 cm around the medial plane through the detector in order to achieve dose homogeneity within the detector volume. The energy correction factor of alanine/paraffin pellets in 192Ir relative to 60Co was experimentally determined as the inverse ratio of the dose to water measured in water around the 192Ir source to the dose to water calculated in water using the TG-43 formalism. The pellets were read out with a Bruker EMXmicro spectrometer (X-band). The amplitude of the central line in the alanine absorption spectrum from pellets irradiated within the 192Ir spectrum was directly compared with the amplitude from 60Co-irradiated pellets. The energy correction factors of Harwell pellets irradiated in the 192Ir spectrum are 1.029 ± 0.02, 1.027 ± 0.02 and 1.045 ± 0.02 at a mean weighted source-detector distance of 2.0, 2.9 and 5.3 cm, respectively. The experimentally obtained values for the energy response are 1.3% lower compared to the theoretical values for radial distances smaller than 3 cm.

  13. 10 CFR 35.2406 - Records of brachytherapy source accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of brachytherapy source accountability. 35.2406... Records of brachytherapy source accountability. (a) A licensee shall maintain a record of brachytherapy source accountability required by § 35.406 for 3 years. (b) For temporary implants, the record...

  14. 10 CFR 35.406 - Brachytherapy sources accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Brachytherapy sources accountability. 35.406 Section 35....406 Brachytherapy sources accountability. (a) A licensee shall maintain accountability at all times... area. (c) A licensee shall maintain a record of the brachytherapy source accountability in...

  15. Dosimetry for the brachytherapy; Dosimetrie fuer die Brachytherapie

    Energy Technology Data Exchange (ETDEWEB)

    Ankerhold, Ulrike [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Fachbereich ' Dosimetrie fuer Strahlentherapie und Roentgendiagnostik' ; Schneider, Thorsten [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe ' Brachytherapie'

    2013-06-15

    The authors describe the calibration of high-dose-rate {sup 192}Ir sources for the use in brachytherapy by means of the air-kerma power, which is determined in the PTB by means of an ionization chamber. For this a primary normal for the representation of the water energy dose was constructed. Furthermore the representation of the reference air-kerma rate for low-dose-rate sources in the PTB by means of a large-volume parallel-plate extrapolation chamber is described. (HSI)

  16. SU-E-T-457: Design and Characterization of An Economical 192Ir Hemi-Brain Small Animal Irradiator

    Energy Technology Data Exchange (ETDEWEB)

    Grams, M; Wilson, Z; Sio, T; Beltran, C; Tryggestad, E; Gupta, S; Blackwell, C; McCollough, K; Sarkaria, J; Furutani, K [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: To describe the design and dosimetric characterization of a simple and economical small animal irradiator. Methods: A high dose rate 192Ir brachytherapy source from a commercially available afterloader was used with a 1.3 centimeter thick tungsten collimator to provide sharp beam penumbra suitable for hemi-brain irradiation of mice. The unit is equipped with continuous gas anesthesia to allow robust animal immobilization. Dosimetric characterization of the device was performed with Gafchromic film. The penumbra from the small animal irradiator was compared under similar collimating conditions to the penumbra from 6 MV photons, 6 MeV electrons, and 20 MeV electrons from a linear accelerator as well as 300 kVp photons from an orthovoltage unit and Monte Carlo simulated 90 MeV protons. Results: The tungsten collimator provides a sharp penumbra suitable for hemi-brain irradiation, and dose rates on the order of 200 cGy/minute were achieved. The sharpness of the penumbra attainable with this device compares favorably to those measured experimentally for 6 MV photons, and 6 and 20 MeV electron beams from a linear accelerator. Additionally, the penumbra was comparable to those measured for a 300 kVp orthovoltage beam and a Monte Carlo simulated 90 MeV proton beam. Conclusions: The small animal irradiator described here can be built for under $1,000 and used in conjunction with any commercial brachytherapy afterloader to provide a convenient and cost-effective option for small animal irradiation experiments. The unit offers high dose rate delivery and sharp penumbra, which is ideal for hemi-brain irradiation of mice. With slight modifications to the design, irradiation of sites other than the brain could be accomplished easily. Due to its simplicity and low cost, the apparatus described is an attractive alternative for small animal irradiation experiments requiring a sharp penumbra.

  17. Investigation of source position uncertainties & balloon deformation in MammoSite brachytherapy on treatment effectiveness.

    Science.gov (United States)

    Bensaleh, S; Bezak, E

    2010-03-01

    The MammoSite breast high dose rate brachytherapy is used in treatment of early-stage breast cancer. The tumour bed volume is irradiated with high dose per fraction in a relatively small number of fractions. Uncertainties in the source positioning and MammoSite balloon deformation will alter the prescribed dose within the treated volume. They may also expose the normal tissues in balloon proximity to excessive dose. The purpose of this work is to explore the impact of these two uncertainties on the MammoSite dose distribution in the breast using dose volume histograms and Monte Carlo simulations. The Lyman-Kutcher and relative seriality models were employed to estimate the normal tissues complications associated with the MammoSite dose distributions. The tumour control probability was calculated using the Poisson model. This study gives low probabilities for developing heart and lung complications. The probability of complications of the skin and normal breast tissues depends on the location of the source inside the balloon and the volume receiving high dose. Incorrect source position and balloon deformation had significant effect on the prescribed dose within the treated volume. A 4 mm balloon deformation resulted in reduction of the tumour control probability by 24%. Monte Carlo calculations using EGSnrc showed that a deviation of the source by 1 mm caused approximately 7% dose reduction in the treated target volume at 1 cm from the balloon surface. In conclusion, accurate positioning of the (192)Ir source at the balloon centre and minimal balloon deformation are critical for proper dose delivery with the MammoSite brachytherapy applicator. On the basis of this study, we suggest that the MammoSite treatment protocols should allow for a balloon deformation of < or = 2 mm and a maximum source deviation of < or = 1 mm.

  18. RESULTS OF 192IR CONTACT RADIATION THERAPY FOR CERVIX UTERI CANCER

    Directory of Open Access Journals (Sweden)

    O. A. Kravets

    2009-01-01

    Full Text Available The paper presents the results of treatment for locally advanced cervix uteri cancer, by applying a 192Ir radioactive source for contact radiation. Three- and five-year overall and relapse-free survival rates have been obtained for stages: 82.5 and 82.5%; 78.4 and 78.4% for Stage IIb; 57 and 52.3%; 41.6 and 41.6 for IIIb; 53.3 and 47.3%; 42.4 and 37.7% for IVb, respectively.

  19. The wall correction factor for a spherical ionization chamber used in brachytherapy source calibration

    Energy Technology Data Exchange (ETDEWEB)

    Piermattei, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Azario, L [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Fidanzio, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Viola, P [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Dell' Omo, C [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Iadanza, L [Centro di Riferimento Oncologico della Basilicata-Rionero in Vulture, Pz (Italy); Fusco, V [Centro di Riferimento Oncologico della Basilicata-Rionero in Vulture, Pz (Italy); Lagares, J I [Universidad de Sevilla, Facultad de Medicina, Dpto Fisiologia Medica y Biofisica, Sevilla (Spain); Capote, R [Universidad de Sevilla, Facultad de Medicina, Dpto Fisiologia Medica y Biofisica, Sevilla (Spain)

    2003-12-21

    The effect of wall chamber attenuation and scattering is one of the most important corrections that must be determined when the linear interpolation method between two calibration factors of an ionization chamber is used. For spherical ionization chambers the corresponding correction factors A{sub w} have to be determined by a non-linear trend of the response as a function of the wall thickness. The Monte Carlo and experimental data here reported show that the A{sub w} factors obtained for an Exradin A4 chamber, used in the brachytherapy source calibration, in terms of reference air kerma rate, are up to 1.2% greater than the values obtained by the linear extrapolation method for the studied beam qualities. Using the A{sub w} factors derived from Monte Carlo calculations, the accuracy of the calibration factor N{sub K,Ir} for the Exradin A4, obtained by the interpolation between two calibration factors, improves about 0.6%. The discrepancy between the new calculated factor and that obtained using the complete calibration curve of the ion-chamber and the {sup 192}Ir spectrum is only 0.1%.

  20. Calibration coefficient of reference brachytherapy ionization chamber using analytical and Monte Carlo methods.

    Science.gov (United States)

    Kumar, Sudhir; Srinivasan, P; Sharma, S D

    2010-06-01

    A cylindrical graphite ionization chamber of sensitive volume 1002.4 cm(3) was designed and fabricated at Bhabha Atomic Research Centre (BARC) for use as a reference dosimeter to measure the strength of high dose rate (HDR) (192)Ir brachytherapy sources. The air kerma calibration coefficient (N(K)) of this ionization chamber was estimated analytically using Burlin general cavity theory and by the Monte Carlo method. In the analytical method, calibration coefficients were calculated for each spectral line of an HDR (192)Ir source and the weighted mean was taken as N(K). In the Monte Carlo method, the geometry of the measurement setup and physics related input data of the HDR (192)Ir source and the surrounding material were simulated using the Monte Carlo N-particle code. The total photon energy fluence was used to arrive at the reference air kerma rate (RAKR) using mass energy absorption coefficients. The energy deposition rates were used to simulate the value of charge rate in the ionization chamber and N(K) was determined. The Monte Carlo calculated N(K) agreed within 1.77 % of that obtained using the analytical method. The experimentally determined RAKR of HDR (192)Ir sources, using this reference ionization chamber by applying the analytically estimated N(K), was found to be in agreement with the vendor quoted RAKR within 1.43%.

  1. Performance assessment of the BEBIG MultiSource high dose rate brachytherapy treatment unit.

    Science.gov (United States)

    Palmer, Antony; Mzenda, Bongile

    2009-12-21

    A comprehensive system characterisation was performed of the Eckert & Ziegler BEBIG GmbH MultiSource High Dose Rate (HDR) brachytherapy treatment unit with an (192)Ir source. The unit is relatively new to the UK market, with the first installation in the country having been made in the summer of 2009. A detailed commissioning programme was devised and is reported including checks of the fundamental parameters of source positioning, dwell timing, transit doses and absolute dosimetry of the source. Well chamber measurements, autoradiography and video camera analysis techniques were all employed. The absolute dosimetry was verified by the National Physical Laboratory, UK, and compared to a measurement based on a calibration from PTB, Germany, and the supplied source certificate, as well as an independent assessment by a visiting UK centre. The use of the 'Krieger' dosimetry phantom has also been evaluated. Users of the BEBIG HDR system should take care to avoid any significant bend in the transfer tube, as this will lead to positioning errors of the source, of up to 1.0 mm for slight bends, 2.0 mm for moderate bends and 5.0 mm for extreme curvature (depending on applicators and transfer tube used) for the situations reported in this study. The reason for these errors and the potential clinical impact are discussed. Users should also note the methodology employed by the system for correction of transit doses, and that no correction is made for the initial and final transit doses. The results of this investigation found that the uncorrected transit doses lead to small errors in the delivered dose at the first dwell position, of up to 2.5 cGy at 2 cm (5.6 cGy at 1 cm) from a 10 Ci source, but the transit dose correction for other dwells was accurate within 0.2 cGy. The unit has been mechanically reliable, and source positioning accuracy and dwell timing have been reproducible, with overall performance similar to other existing HDR equipment. The unit is capable of high

  2. Comparison of TG-43 dosimetric parameters of brachytherapy sources obtained by three different versions of MCNP codes.

    Science.gov (United States)

    Zaker, Neda; Zehtabian, Mehdi; Sina, Sedigheh; Koontz, Craig; Meigooni, Ali S

    2016-03-01

    Monte Carlo simulations are widely used for calculation of the dosimetric parameters of brachytherapy sources. MCNP4C2, MCNP5, MCNPX, EGS4, EGSnrc, PTRAN, and GEANT4 are among the most commonly used codes in this field. Each of these codes utilizes a cross-sectional library for the purpose of simulating different elements and materials with complex chemical compositions. The accuracies of the final outcomes of these simulations are very sensitive to the accuracies of the cross-sectional libraries. Several investigators have shown that inaccuracies of some of the cross section files have led to errors in  125I and  103Pd parameters. The purpose of this study is to compare the dosimetric parameters of sample brachytherapy sources, calculated with three different versions of the MCNP code - MCNP4C, MCNP5, and MCNPX. In these simulations for each source type, the source and phantom geometries, as well as the number of the photons, were kept identical, thus eliminating the possible uncertainties. The results of these investigations indicate that for low-energy sources such as  125I and  103Pd there are discrepancies in gL(r) values. Discrepancies up to 21.7% and 28% are observed between MCNP4C and other codes at a distance of 6 cm for  103Pd and 10 cm for  125I from the source, respectively. However, for higher energy sources, the discrepancies in gL(r) values are less than 1.1% for  192Ir and less than 1.2% for  137Cs between the three codes. PACS number(s): 87.56.bg.

  3. Effect of chemical composition and density of the pelvic structure in intracavitary brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chavez-Aguilera, N. [Coordinacion de Investigacion y Estudios de Posgrado, Facultad de Medicina, Universidad Autonoma del Estado de Mexico, Paseo Tollocan s/n Esquina con Jesus Carranza, 50180 Toluca (Mexico); Departamento de Fisica Medica, Instituto Estatal de Cancerologia ' Dr. Arturo Beltran Ortega' , Acapulco, Guerrero (Mexico); Torres-Garcia, E., E-mail: etorresg@uaemex.m [Coordinacion de Investigacion y Estudios de Posgrado, Facultad de Medicina, Universidad Autonoma del Estado de Mexico, Paseo Tollocan s/n Esquina con Jesus Carranza, 50180 Toluca (Mexico); Mitsoura, E. [Coordinacion de Investigacion y Estudios de Posgrado, Facultad de Medicina, Universidad Autonoma del Estado de Mexico, Paseo Tollocan s/n Esquina con Jesus Carranza, 50180 Toluca (Mexico)

    2011-03-15

    High dose rate (HDR) and low dose rate (LDR) intracavitary brachytherapies dosimetry in clinical practice are typically performed by commercial treatment planning systems. However, these systems do not fully consider the heterogeneities present in the real structure of the patient. The aim of this work is to obtain isodose curves and surfaces around the usual array of sources used in LDR ({sup 137}Cs) and HDR ({sup 192}Ir) intracavitary brachytherapy by Monte Carlo simulation, considering the real anatomic structure, density and chemical composition of media and tissues from the female pelvic region. The structural information was obtained from computed tomography images in the DICOM format. A voxel phantom (VP) was developed to perform ionizing radiation transport, considering the gamma spectrum of {sup 137}Cs and {sup 192}Ir. The absorbed dose was computed within each voxel of 2x2x3 mm{sup 3}. Four materials were considered in the VP-air, fat, muscle tissue and bone; however, one material per voxel was defined. Results show and quantify the effect of density and chemical composition of the medium on the absorbed dose distribution. According to them, the treatment planning systems underestimate the absorbed dose by 8% approximately for both radionuclides. In a heterogeneous medium, the absorbed dose distribution of {sup 192}Ir is more irregular than that of {sup 137}Cs but spatially better defined.

  4. Dosimetry of IRIDIUM-192 and CESIUM-137 Seed Sources.

    Science.gov (United States)

    Thomason, Cynthia

    The use of ^{192}Ir in brachytherapy implants both alone and in conjunction with other modalities for the treatment of various types of cancer has greatly increased in recent years. This increased usage has led to a greater need for detailed information concerning the dose distribution surrounding commerically available ^{192} Ir seed sources. This is especially truce since improvements in computer technology along with their increased availability and utilization have enabled more precise calculation of dose distributions. The radiation does distribution in water was measured using LiF thermoluminescent dosimeters for an ^{192}Ir seed source with platinum encapsulation, for an ^{192}Ir seed source with stainless steel encapsulation and for a ^{137}Cs seed source intended as a substitute for ^{192 }Ir. The Electron-Gamma-Shower (EGS) computer code, which is a package for doing Monte Carlo simulation of the transport of photons and electrons in any medium or geometry specified by the user, also was used to study the dose distribution around these seed sources. In addition, the exposure rate constant, exposure rate at 1 meter, transmission through the source capsule, f-factor, and energy distribution exiting the source capsule were evaluated by Monte Carlo simulation of these three sources. Good agreement was seen between the measured data and the Monte Carlo generated data. In addition to producing valuable dosimetric data, this study has demonstrated that Monte Carlo modeling of ^{192} Ir and ^{137}Cs seed sources using the EGS Monte Carlo code can provide an accurate means of evaluating these data.

  5. Reply to the comment on ‘Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation’

    Science.gov (United States)

    Villegas, F.; Ahnesjö, A.

    2016-07-01

    A discrepancy between the Monte Carlo derived relative standard deviation σ z\\text{rel} (microdosimetric spread) and experimental data was reported by Villegas et al (2013 Phys. Med. Biol. 58 6149-62) suggesting wall effects as a plausible explanation. The comment by Lindborg et al (2015 Phys. Med. Biol. 60 8621-4) concludes that this is not a likely explanation. A thorough investigation of the Monte Carlo (MC) transport code used for track simulation revealed a critical bug. The corrected MC version yielded σ z\\text{rel} values that are now within experimental uncertainty. Other microdosimetric findings are hereby communicated.

  6. Biological dosimetry for the victim accidentally exposed to 192Ir radiation source at "5.7" accident in Nanjing%南京“5.7”192Ir源放射事故患者的生物剂量估算

    Institute of Scientific and Technical Information of China (English)

    戴宏; 刘玉龙; 王优优; 冯骏超; 赵骅; 刘青杰; 郭凯琳

    2016-01-01

    Objective To use three different methods in attempt to estimate the biological dose of the patient partially exposed to 192Ir source at " 5.7" accident in Nanjing,so as to provide dosimetric information for clinical remedy of exposed patients in the emergency of a nuclear accident.Methods Peripheral blood samples were collected on days 5 after exposure.The biological dose was estimated by the yields of dicentrics plus rings (" dic + r"),cytokinesis-block micronuclei (CBMN) assay and nucleoplasmic bridge plus FHC (NPB + FHC).The homogeneity of radiation exposure was examined by Poisson distribution of dicentrics.Results By using three different methods,the whole body equivalent dose was "dic + r" estimated to be 1.51 Gy (95% CI 1.40-1.61),1.47 Gy (95% CI 1.36-1.60) by CBMN and 1.30 Gy (95% CI 1.00-1.60) by NPB + FHC,respectively.A non-poisson distribution was also detected,suggesting partial body radiation exposure.Conclusions The estimated whole body equivalent dose ot a non-uniform radiation exposure was consistent with clinical diagnosis,suggesting that the yields of " dic + r",CBMN,as well as NPB + FHC,are efficient approaches to the estimation of biological doses.%目的 用3种方法估算南京“5.7”192Ir源放射事故患者的生物剂量,为核与辐射事故受照者的临床救治提供剂量资料.方法 受照后第5天采集患者外周血,分别进行外周血淋巴细胞染色体“双着丝粒+环”(“dic+r”)畸变分析、胞质分裂阻滞微核(CBMN)分析、核质桥(NPB+FHC)分析,并估算生物剂量.用双着丝粒畸变在细胞间的泊松分布情况检验照射的均匀性.结果 3种方法估算的该患者受到的一次全身等效剂量分别为“dic+r”畸变分析1.51 Gy (95% CI1.40~1.61),CBMN分析1.47 Gy(95% CI 1.36~1.60),NPB+ FHC分析1.30 Gy(95% CI1.00~1.60).泊松分布检验结果显示,该患者“dic+r”畸变偏离泊松分布,受到了不均匀照射.结论 外周血淋巴细胞染色体“dic

  7. Dynamic analysis on three indexes of biological dose estimation of the victim exposed to 192Ir radiation source at "5.7" accident in Nanjing%南京“5.7”192Ir放射事故患者三种生物剂量估算指标的衰变规律探讨

    Institute of Scientific and Technical Information of China (English)

    戴宏; 刘玉龙; 王优优; 冯骏超; 赵骅; 刘青杰; 郭凯琳

    2016-01-01

    目的 观察南京“5.7”192Ir放射事故患者受照后不同采血时间对生物剂量估算的影响,探讨3种生物剂量估算指标在体内的自然衰减规律.方法 事故后5、40和280 d,采集患者的外周血,分别进行外周血淋巴细胞染色体“双着丝粒+环”(“dic+r”)畸变分析、胞质分裂阻滞微核(CBMN)分析、核质桥+融合+马蹄形+环(NPB +FHC)分析.观察受照后不同时间染色体“dic+r”畸变、微核、NPB+FHC衰变情况及对生物剂量估算结果的影响.结果 与事故后5d的估算剂量相比,在40和280 d,染色体“dic+r”畸变分析估算的剂量分别下降34%和49%,CBMN的估算结果分别下降48%和79%,NPB+FHC的估算结果分别下降48%和75%.结论 本例事故患者受照后3种生物剂量估算指标在体内呈进行性下降,染色体“dic+r”/细胞的半衰期为40 d,3个指标在40 d时剂量估算结果与5d时比较,相对偏差>20%.%Objective To explore the natural attenuation pattern of three biological dose estimation indexes in vivo by investigating the effect on biological dosimetry of peripheral blood sampling at different time points from the victim partially exposed to 192Ir radiation source at " 5.7" accident in Nanjing.Methods Peripheral blood of the patient was collected on days 5,40 and 280 after exposure,respectively.The yields of dicentrics plus rings chromosomes ("dic + r"),cytokinesis-block micronuclei (CBMN) and nucleoplasmic bridge + fusion + horse shoe + circular(NPB + FHC) were analyzed.The dynamic reduction and dose estimation were both observed using the biomarkers mentioned above after exposure.Results Compared to the estimates on days 5 after exposure,the dose values estimated on days 40 and 280 decreased by 34% and 49% for " dic + r" method,48% and 79% for the CBMN assay,and 48% and 75% for NPN + FHC method,respectively.Conclusions Three biological dose estimation indexes show a progressive decrease in vivo

  8. The dosimetric feasibility of gold nanoparticle-aided radiation therapy (GNRT) via brachytherapy using low-energy gamma-/x-ray sources.

    Science.gov (United States)

    Cho, Sang Hyun; Jones, Bernard L; Krishnan, Sunil

    2009-08-21

    The preferential accumulation of gold nanoparticles within tumors and the increased photoelectric absorption due to the high atomic number of gold cooperatively account for the possibility of significant tumor dose enhancement during gold nanoparticle-aided radiation therapy (GNRT). Among the many conceivable ways to implement GNRT clinically, a brachytherapy approach using low-energy gamma-/x-ray sources (i.e. E(avg) 40%) could be achievable using (125)I, 50 kVp and (169)Yb sources and gold nanoparticles. When calculated at 1.0 cm from the center of the source within a tumor loaded with 18 mg Au g(-1), macroscopic dose enhancement was 116, 92 and 108% for (125)I, 50 kVp and (169)Yb, respectively. For a tumor loaded with 7 mg Au g(-1), it was 68, 57 and 44% at 1 cm from the center of the source for (125)I, 50 kVp and (169)Yb, respectively. The estimated MDEF values for (169)Yb were remarkably larger than those for (192)Ir, on average by up to about 70 and 30%, for 18 mg Au and 7 mg Au cases, respectively. The current MC study also shows a remarkable change in the photoelectron fluence and spectrum (e.g. more than two orders of magnitude) and a significant production (e.g. comparable to the number of photoelectrons) of the Auger electrons within the tumor region due to the presence of gold nanoparticles during low-energy gamma-/x-ray irradiation. The radiation sources considered in this study are currently available and tumor gold concentration levels considered in this investigation are deemed achievable. Therefore, the current results strongly suggest that GNRT can be successfully implemented via brachytherapy with low energy gamma-/x-ray sources, especially with a high dose rate (169)Yb source.

  9. Third-party brachytherapy source calibrations and physicist responsibilities: report of the AAPM Low Energy Brachytherapy Source Calibration Working Group.

    Science.gov (United States)

    Butler, Wayne M; Bice, William S; DeWerd, Larry A; Hevezi, James M; Huq, M Saiful; Ibbott, Geoffrey S; Palta, Jatinder R; Rivard, Mark J; Seuntjens, Jan P; Thomadsen, Bruce R

    2008-09-01

    The AAPM Low Energy Brachytherapy Source Calibration Working Group was formed to investigate and recommend quality control and quality assurance procedures for brachytherapy sources prior to clinical use. Compiling and clarifying recommendations established by previous AAPM Task Groups 40, 56, and 64 were among the working group's charges, which also included the role of third-party handlers to perform loading and assay of sources. This document presents the findings of the working group on the responsibilities of the institutional medical physicist and a clarification of the existing AAPM recommendations in the assay of brachytherapy sources. Responsibility for the performance and attestation of source assays rests with the institutional medical physicist, who must use calibration equipment appropriate for each source type used at the institution. Such equipment and calibration procedures shall ensure secondary traceability to a national standard. For each multi-source implant, 10% of the sources or ten sources, whichever is greater, are to be assayed. Procedures for presterilized source packaging are outlined. The mean source strength of the assayed sources must agree with the manufacturer's stated strength to within 3%, or action must be taken to resolve the difference. Third party assays do not absolve the institutional physicist from the responsibility to perform the institutional measurement and attest to the strength of the implanted sources. The AAPM leaves it to the discretion of the institutional medical physicist whether the manufacturer's or institutional physicist's measured value should be used in performing dosimetry calculations.

  10. Fabrication of cesium-137 brachytherapy sources using vitrification technology.

    Science.gov (United States)

    Dash, Ashutosh; Varma, R N; Ram, Ramu; Saxena, S K; Mathakar, A R; Avhad, B G; Sastry, K V S; Sangurdekar, P R; Venkatesh, Meera

    2009-08-01

    137Cs source in solid matrix encapsulated in stainless-steel at MBq (mCi) levels are widely used as brachytherapy sources for the treatment of carcinoma of cervix uteri. This article describes the large-scale preparation of such sources. The process of fabrication includes vitrification of 137Cs-sodium borosilicate glass, its transformation into spheres of 5-6 mm diameter, casting of glass spheres into a cylinder of 1.5 mm (varphi) x 80 mm (l) in a platinum mould, cutting of the moulds into 5-mm-long pieces, silver coating on the sources, and finally, encapsulation in stainless steel capsules. Development of safety precautions used to trap 137Cs escaping during borosilicate glass preparation is also described. The leach rates of the radioactive sources prepared by the above technology were within permissible limits, and the sources could be used for encapsulation in stainless steel capsules and supplied for brachytherapy applications. This development was aimed at promoting the potential utility of 137Cs-brachytherapy sources in the country and reducing the user's reliance on imported sources. Since its development, more than 1000 such sources have been made by using 4.66 TBq(126 Ci) of 137Cs.

  11. Size Effects of Gold and Iron Nanoparticles on Radiation Dose Enhancement in Brachytherapy and Teletherapy: A Monte Carlo Study

    Directory of Open Access Journals (Sweden)

    Ahad Ollah Ezzati

    2014-08-01

    Full Text Available Introduction In this study, we aimed to calculate dose enhancement factor (DEF for gold (Au and iron (Fe nanoparticles (NPs in brachytherapy and teletherapy, using Monte Carlo (MC method. Materials and Methods In this study, a new algorithm was introduced to calculate dose enhancement by AuNPs and FeNPs for Iridium-192 (Ir-192 brachytherapy and Cobalt-60 (Co-60 teletherapy sources, using the MC method. In this algorithm, the semi-random distribution of NPs was used instead of the regular distribution. Diameters were assumed to be 15, 30, and 100 nm in brachytherapy and 15 and 30 nm in teletherapy. Monte Carlo MCNP4C code was used for simulations, and NP density values were 0.107 mg/ml and 0.112 mg/ml in brachytherapy and teletherapy, respectively. Results AuNPs significantly enhanced the radiation dose in brachytherapy (approximately 60%, and 100 nm diameter NPs showed the most uniform dose distribution. AuNPs had an insignificant effect on teletherapy radiation field, with a dose enhancement ratio of 3% (about the calculation uncertainty or less. In addition, FeNPs had an insignificant effect on both brachytherapy and teletherapy radiation fields. FeNPs dose enhancement was 3% in brachytherapy and 6% (about the calculation uncertainty or less in teletherapy. Conclusion It can be concluded that AuNPs can significantly increase the absorbed dose in brachytherapy; however, FeNPs do not have a noticeable effect on the absorbed dose

  12. Correction factors for source strength determination in HDR brachytherapy using the in-phantom method

    Energy Technology Data Exchange (ETDEWEB)

    Ubrich, Frank; Engenhart-Cabillic, Rita [University Hospital Giessen-Marburg, Marburg (Germany). Dept. of Radiotherapy and Radiation Oncology; Wulff, Joerg [University of Applied Sciences (THM) Giessen (Germany). Inst. of Medical Physics and Radiation Protection (IMPS); Zink, Klemens [University Hospital Giessen-Marburg, Marburg (Germany). Dept. of Radiotherapy and Radiation Oncology; University of Applied Sciences (THM) Giessen (Germany). Inst. of Medical Physics and Radiation Protection (IMPS)

    2014-09-01

    For the purpose of clinical source strength determination for HDR brachytherapy sources, the German society for Medical Physics (DGMP) recommends in their report 13 the usage of a solid state phantom (Krieger-phantom) with a thimble ionization chamber. In this work, the calibration chain for the determination of the reference air-kerma rate K{sub a,100} and reference dose rate to water D{sub w,1} by ionization chamber measurement in the Krieger-phantom was modeled via Monte Carlo simulations. These calculations were used to determine global correction factors k{sub tot}, which allows a user to directly convert the reading of an ionization chamber calibrated in terms of absorbed dose to water, into the desired quantity K{sub a,100} or D{sub w,1}. The factor k{sub tot} was determined for four available {sup 192}Ir sources and one {sup 60}Co source with three different thimble ionization chambers. Finally, ionization chamber measurements on three μSelectron V2 HDR sources within the Krieger-phantom were performed and K{sub a,100} was determined according to three different methods: (1) using a calibration factor in terms of absorbed dose to water wth the global correction factor (k{sub tot}){sub K{sub a{sub ,{sub 1{sub 0{sub 0}}}}}} according DGMP 13 (2) using a global correction factor calculated via Monte Carlo (3) using a direct reference air-kerma rate calibration factor determined by the national metrology institute PTB. The comparison of Monte Carlo based (k{sub tot}){sub K{sub a{sub ,{sub 1{sub 0{sub 0}}}}}} with those from DGMP 13 showed that the DGMP data were systematically smaller by about 2-2.5%. The experimentally determined (k{sub tot}){sub K{sub a{sub ,{sub 1{sub 0{sub 0}}}}}}, based on the direct K{sub a,100} calibration were also systematically smaller by about 1.5%. Despite of these systematical deviations, the agreement of the different methods was in almost all cases within the 1σ level of confidence of the interval of their respective

  13. Calculated organ doses using Monte Carlo simulations in a reference male phantom undergoing HDR brachytherapy applied to localized prostate carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, Cristian [Radioprotection Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Perez-Calatayud, Jose [Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Ballester, Facundo [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2013-03-15

    Purpose: The aim of this study was to obtain equivalent doses in radiosensitive organs (aside from the bladder and rectum) when applying high-dose-rate (HDR) brachytherapy to a localized prostate carcinoma using {sup 60}Co or {sup 192}Ir sources. These data are compared with results in a water phantom and with expected values in an infinite water medium. A comparison with reported values from proton therapy and intensity-modulated radiation therapy (IMRT) is also provided. Methods: Monte Carlo simulations in Geant4 were performed using a voxelized phantom described in International Commission on Radiological Protection (ICRP) Publication 110, which reproduces masses and shapes from an adult reference man defined in ICRP Publication 89. Point sources of {sup 60}Co or {sup 192}Ir with photon energy spectra corresponding to those exiting their capsules were placed in the center of the prostate, and equivalent doses per clinical absorbed dose in this target organ were obtained in several radiosensitive organs. Values were corrected to account for clinical circumstances with the source located at various positions with differing dwell times throughout the prostate. This was repeated for a homogeneous water phantom. Results: For the nearest organs considered (bladder, rectum, testes, small intestine, and colon), equivalent doses given by {sup 60}Co source were smaller (8%-19%) than from {sup 192}Ir. However, as the distance increases, the more penetrating gamma rays produced by {sup 60}Co deliver higher organ equivalent doses. The overall result is that effective dose per clinical absorbed dose from a {sup 60}Co source (11.1 mSv/Gy) is lower than from a {sup 192}Ir source (13.2 mSv/Gy). On the other hand, equivalent doses were the same in the tissue and the homogeneous water phantom for those soft tissues closer to the prostate than about 30 cm. As the distance increased, the differences of photoelectric effect in water and soft tissue, and appearance of other materials

  14. Verification of Oncentra brachytherapy planning using independent calculation

    Science.gov (United States)

    Safian, N. A. M.; Abdullah, N. H.; Abdullah, R.; Chiang, C. S.

    2016-03-01

    This study was done to investigate the verification technique of treatment plan quality assurance for brachytherapy. It is aimed to verify the point doses in 192Ir high dose rate (HDR) brachytherapy between Oncentra Masterplan brachytherapy treatment planning system and independent calculation software at a region of rectum, bladder and prescription points for both pair ovoids and full catheter set ups. The Oncentra TPS output text files were automatically loaded into the verification programme that has been developed based on spreadsheets. The output consists of source coordinates, desired calculation point coordinates and the dwell time of a patient plan. The source strength and reference dates were entered into the programme and then dose point calculations were independently performed. The programme shows its results in a comparison of its calculated point doses with the corresponding Oncentra TPS outcome. From the total of 40 clinical cases that consisted of two fractions for 20 patients, the results that were given in term of percentage difference, it shows an agreement between TPS and independent calculation are in the range of 2%. This programme only takes a few minutes to be used is preferably recommended to be implemented as the verification technique in clinical brachytherapy dosimetry.

  15. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Alvarez, Paola; Lawyer, Ann [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2013-11-15

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm{sup 3} prototype phantom that had two slots capable of holding Al{sub 2}O{sub 3}:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all {sup 192}Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian {sup 192}Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k{sub L}= (−9.43 × 10{sup −5}× dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using {sup 60}Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian {sup 192}Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance

  16. Investigation of the gold nanoparticles effects on the prostate dose distribution in brachytherapy: gel dosimetry and Monte Carlo method

    Science.gov (United States)

    Hashemi, Bijan; Rahmani, Faezeh; Ebadi, Ahmad

    2016-01-01

    Purpose In this work, gold nanoparticles (GNPs) were embedded in the MAGIC-f polymer gel irradiated with the 192Ir brachytherapy sources. Material and methods At the first plexiglas phantom was made as the human pelvis. The GNPs were synthesized with 15 nm in diameter and 0.1 mM (0.0197 mg/ml) in concentration by using a chemical reduction method. Then, the MAGIC-f gel was synthesized. The fabricated gel was poured into the tubes located at the prostate (with and without the GNPs) locations of the phantom. The phantom was irradiated with 192Ir brachytherapy sources for prostate cancer. After 24 hours, the irradiated gels was read by using Siemens 1.5 Tesla MRI scanner. Following the brachytherapy practices, the absolute doses at the reference points and isodose curves were extracted and compared by experimental measurements and Monte Carlo (MC) simulations. Results The mean absorbed doses in the presence of the GNPs in prostate were 14% higher than the corresponding values without the GNPs in the brachytherapy. The gamma index analysis (between gel and MC) using 7%/7 mm was also applied to the data and a high pass rate achieved (91.7% and 86.4% for analysis with/without GNPs, respectively). Conclusions The real three-dimensional analysis shows the comparison of the dose-volume histograms measured for planning volumes and the expected one from the MC calculation. The results indicate that the polymer gel dosimetry method, which developed and used in this study, could be recommended as a reliable method for investigating the dose enhancement factor of GNPs in brachytherapy. PMID:27895684

  17. The dosimetric feasibility of gold nanoparticle-aided radiation therapy (GNRT) via brachytherapy using low-energy gamma-/x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Hyun; Jones, Bernard L [Nuclear/Radiological Engineering and Medical Physics Programs, Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States); Krishnan, Sunil [Department of Radiation Oncology, The University of Texas M D Anderson Cancer Center, 1515 Holcombe Blvd, Unit 97, Houston, TX 77030 (United States)], E-mail: scho@gatech.edu

    2009-08-21

    The preferential accumulation of gold nanoparticles within tumors and the increased photoelectric absorption due to the high atomic number of gold cooperatively account for the possibility of significant tumor dose enhancement during gold nanoparticle-aided radiation therapy (GNRT). Among the many conceivable ways to implement GNRT clinically, a brachytherapy approach using low-energy gamma-/x-ray sources (i.e. E{sub avg} < 100 keV) appears to be highly feasible and promising, because it may easily fulfill some of the technical and clinical requirements for GNRT. Therefore, the current study investigated the dosimetric feasibility of implementing GNRT using the following sources: {sup 125}I, 50 kVp and {sup 169}Yb. Specifically, Monte Carlo (MC) calculations were performed to determine the macroscopic dose enhancement factors (MDEF), defined as the ratio of the average dose in the tumor region with and without the presence of gold nanoparticles during the irradiation of the tumor, and the photo/Auger electron spectra within a tumor loaded with gold nanoparticles. The current study suggests that a significant tumor dose enhancement (e.g. >40%) could be achievable using {sup 125}I, 50 kVp and {sup 169}Yb sources and gold nanoparticles. When calculated at 1.0 cm from the center of the source within a tumor loaded with 18 mg Au g{sup -1}, macroscopic dose enhancement was 116, 92 and 108% for {sup 125}I, 50 kVp and {sup 169}Yb, respectively. For a tumor loaded with 7 mg Au g{sup -1}, it was 68, 57 and 44% at 1 cm from the center of the source for {sup 125}I, 50 kVp and {sup 169}Yb, respectively. The estimated MDEF values for {sup 169}Yb were remarkably larger than those for {sup 192}Ir, on average by up to about 70 and 30%, for 18 mg Au and 7 mg Au cases, respectively. The current MC study also shows a remarkable change in the photoelectron fluence and spectrum (e.g. more than two orders of magnitude) and a significant production (e.g. comparable to the number of

  18. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy; Proteccion radiologica en Braquiterapia. Informe del grupo de trabajo de Braquiterapia de la SEFM

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J.; Corredoira Silva, E.; Crispin Contreras, V.; Eudaldo Puell, T.; Frutos Baraja, J. de; Pino Sorroche, F.; Pujades Claumarchirant, M. C.; Richart Sancho, J.

    2015-07-01

    This document presents the report of the Brachytherapy Task Group of the Spanish Society of Medical Physics. It is dedicated to the radiation protection aspects involved in brachytherapy. The aim of this work is to include the more relevant aspects related to radiation protection issues that appear in clinical practice, and for the current equipment in Spain. Basically this report focuses on the typical contents associated with high dose rate brachytherapy with {sup 1}92Ir and {sup 6}0Co sources, and permanent seed implants with {sup 1}25I, {sup 1}03Pd and {sup 1}31Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with {sup 1}25I, {sup 1}06Ru, {sup 9}0Sr) is also included due to its availability in a significant number of spanish hospitals. The purpose of this report is to assist to the medical physicist community in establishing a radiation protection program for brachytherapy procedures, trying to solve some ambiguities in the application of legal requirements and recommendations in clinical practice. (Author)

  19. Brachytherapy optimal planning with application to intravascular radiation therapy

    DEFF Research Database (Denmark)

    Sadegh, Payman; Mourtada, Firas A.; Taylor, Russell H.;

    1999-01-01

    . Dose rate calculations are based on the sosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes...

  20. Monte Carlo studies on water and LiF cavity properties for dose-reporting quantities when using x-ray and brachytherapy sources

    Science.gov (United States)

    Soares Lopes Branco, Isabela; Guimarães Antunes, Paula Cristina; Paiva Fonseca, Gabriel; Yoriyaz, Hélio

    2016-12-01

    Model-based dose calculation algorithms (MBDCAs) are the current tools to estimate dose in brachytherapy, which takes into account heterogeneous medium, therefore, departing from water-based formalism (TG-43). One aspect associated to MBCDA is the choice of dose specification medium since it offers two possibilities to report dose: (a) dose to medium in medium, D m,m; and (b) dose to water in medium, D w,m. The discussion about the preferable quantity to be reported is underway. The dose conversion factors, DCF, between dose to water in medium, D w,m, and dose to medium in medium, D m,m, is based on cavity theory and can be obtained using different approaches. When experimental dose verification is desired using, for example, thermoluminescent LiF dosimeters, as in in vivo dose measurements, a third quantity is obtained, which is the dose to LiF in medium, D LiF,m. In this case, DCF to convert from D LiF,m to D w,m or D m,m is necessary. The objective of this study is to estimate DCFs using different approaches, present in the literature, quantifying the differences between them. Also, dose in water and LiF cavities in different tissue media and respective conversion factors to be able to convert LiF-based dose measured values into dose in water or tissue were obtained. Simple cylindrical phantoms composed by different tissue equivalent materials (bone, lung, water and adipose) are modelled. The phantoms contain a radiation source and a cavity with 0.002 69 cm3 in size, which is a typical volume of a disc type LiF dosimeter. Three x-rays qualities with average energies ranging from 47 to 250 keV, and three brachytherapy sources, 60Co, 192Ir and 137Cs, are considered. Different cavity theory approaches for DCF calculations and different cavity/medium combinations have been considered in this study. DCF values for water/bone and LiF/bone cases have strong dependence with energy increasing as the photon energy increases. DCF values also increase with energy for

  1. A Monte Carlo dosimetry study using Henschke applicator for cervical brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Pei-Chieh [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, 101 Sec. 2, Kung Fu Road, Hsinchu 30013, Taiwan (China); Department of Radiation Oncology, Cathay General Hospital, 280 Renai Rd. Sec.4, Taipei 106, Taiwan (China); Chao, Tsi-Chian [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, 5 Fu-Hsin Street, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Wu, Ching-Jung [Department of Radiation Oncology, Cathay General Hospital, 280 Renai Rd. Sec.4, Taipei 106, Taiwan (China); Tung, Chuan-Jong, E-mail: cjtung@mail.cgu.edu.t [Department of Medical Imaging and Radiological Science, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China)

    2010-07-21

    In recent years the Henschke applicator has been widely used for gynecologic patients treated by brachytherapy in Taiwan. However, the commercial brachytherapy planning system did not properly evaluate the dose perturbation caused by the Henschke applicator. Since the European Society for Therapeutic Radiology and Oncology advised that the effect of source shielding should be incorporated into the brachytherapy planning system, it required calculation and comparison of the dose distribution around the applicator. This study used the Monte Carlo MCNP code to simulate the dose distribution in a water phantom that contained the Henschke applicator with one tandem and two ovoids. Three dwell positions of a high dose rate {sup 192}Ir source were simulated by including and excluding the applicator. The mesh tally option of the MCNP was applied to facilitate the calculation of a large number of tallies in the phantom. The voxel size effect and the charge particle equilibrium were studied by comparing the results calculated with different tally options. The calculated results showed that the brachytherapy planning system overestimated the rectal dose and that the shielding material in the applicator contributed more than 40% to the rectal dose.

  2. Monte Carlo model for a prototype CT-compatible, anatomically adaptive, shielded intracavitary brachytherapy applicator for the treatment of cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Price, Michael J.; Gifford, Kent A.; Horton, John L. Jr.; Eifel, Patricia J.; Gillin, Michael T.; Lawyer, Ann A.; Mourtada, Firas [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1220 Holcombe Boulevard, Houston, Texas 77030 and Graduate School of Biomedical Sciences, University of Texas-Houston, 6767 Bertner Avenue, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1220 Holcombe Boulevard, Houston, Texas 77030 (United States); Division of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, 1220 Holcombe Boulevard, Houston, Texas 77030 and Graduate School of Biomedical Sciences, University of Texas-Houston, 6767 Bertner Avenue, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1220 Holcombe Boulevard, Houston, Texas 77030 and Graduate School of Biomedical Sciences, University of Texas-Houston, 6767 Bertner Avenue, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1220 Holcombe Boulevard, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1220 Holcombe Boulevard, Houston, Texas 77030 and Graduate School of Biomedical Sciences, University of Texas-Houston, 6767 Bertner Avenue, Houston, Texas 77030 (United States)

    2009-09-15

    Purpose: Current, clinically applicable intracavitary brachytherapy applicators that utilize shielded ovoids contain a pair of tungsten-alloy shields which serve to reduce dose delivered to the rectum and bladder during source afterloading. After applicator insertion, these fixed shields are not necessarily positioned to provide optimal shielding of these critical structures due to variations in patient anatomies. The authors present a dosimetric evaluation of a novel prototype intracavitary brachytherapy ovoid [anatomically adaptive applicator (A{sup 3})], featuring a single shield whose position can be adjusted with two degrees of freedom: Rotation about and translation along the long axis of the ovoid. Methods: The dosimetry of the device for a HDR {sup 192}Ir was characterized using radiochromic film measurements for various shield orientations. A MCNPX Monte Carlo model was developed of the prototype ovoid and integrated with a previously validated model of a v2 mHDR {sup 192}Ir source (Nucletron Co.). The model was validated for three distinct shield orientations using film measurements. Results: For the most complex case, 91% of the absolute simulated and measured dose points agreed within 2% or 2 mm and 96% agreed within 10% or 2 mm. Conclusions: Validation of the Monte Carlo model facilitates future investigations into any dosimetric advantages the use of the A{sup 3} may have over the current state of art with respect to optimization and customization of dose delivery as a function of patient anatomical geometries.

  3. Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX

    Science.gov (United States)

    Purwaningsih, Anik

    2014-09-01

    Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.

  4. Simulation of dose distribution for iridium-192 brachytherapy source type-H01 using MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Purwaningsih, Anik [Center for development of nuclear informatics, National Nuclear Energy Agency, PUSPIPTEK, Serpong, Banten 15310 (Indonesia)

    2014-09-30

    Dosimetric data for a brachytherapy source should be known before it used for clinical treatment. Iridium-192 source type H01 was manufactured by PRR-BATAN aimed to brachytherapy is not yet known its dosimetric data. Radial dose function and anisotropic dose distribution are some primary keys in brachytherapy source. Dose distribution for Iridium-192 source type H01 was obtained from the dose calculation formalism recommended in the AAPM TG-43U1 report using MCNPX 2.6.0 Monte Carlo simulation code. To know the effect of cavity on Iridium-192 type H01 caused by manufacturing process, also calculated on Iridium-192 type H01 if without cavity. The result of calculation of radial dose function and anisotropic dose distribution for Iridium-192 source type H01 were compared with another model of Iridium-192 source.

  5. A Scintillating Fiber Dosimeter for Radiology and Brachytherapy with photodiode readout

    CERN Document Server

    Rêgo, Florbela; Abreu, Maria da Conceição

    2011-01-01

    Purpose: For more than a decade that plastic optical fiber based dosimeters have been developed for medical applications. The feasibility of dosimeters using optical fibers that are almost Cherenkov light free has been demonstrated in some prototypes, particularly suitable for photon high-energy beams. In the energy range up to a few hundred keV, where the production of Cherenkov light by secondary electrons is negligible or small, the largest source of background are the fluorescence mechanisms. Methods: In recent years our group has developed an optical fiber dosimeter with photodiode readout named DosFib, which has small energy dependence in the range below 100 keV relevant for radiology. Photodiodes are robust photodetectors, presenting good stability over time and enough sensitivity to allow the use of an electrometer as a measuring device without extra electronics. Results: In-vitro tests using a High Dose Rate 192Ir source have demonstrated its suitability for brachytherapy applications using this impo...

  6. Pulsed dose rate (PDR) brachytherapy as salvage treatment of locally advanced or recurrent gynecologic cancer

    DEFF Research Database (Denmark)

    Jensen, P T; Roed, H; Engelholm, S A

    1998-01-01

    been treated with external irradiation, four-field box technique, to 46 Gy/23 fractions, 5 F/week and 192Ir-interstitial PDR-brachytherapy in pulses of 0.6 Gy, one pulse per hour to a total of 30 Gy. The Martinez Universal Perineal Interstitial Template applicator was used for all implantations...

  7. 南京“5.7”192Ir源放射事故患者的神经行为及心理健康改变%Nervous behavior and mental health changes in a case exposed to 192Ir source at "5.7" accident in Nanjing

    Institute of Scientific and Technical Information of China (English)

    陈炜博; 刘玉龙; 卞华慧; 王优优; 李元; 郑旭; 包明月; 郭凯琳

    2016-01-01

    Objective To explore the changes in nervous behavior and mental health caused by radiation damage,and to provide clinical data and experience for the similar cases,based on the treatment process of the patient exposed to Iridium-192 source accident in Nanjing,Methods The changes in the mental status of the patient was observed closely in a manner of " one to one",or " several to one",gave psychological intervention and drug treatment.The psychological evaluation for the patient was carried out by using Cattell 16 personality factors test (16PF),self-rating depression scale (SDS) and self-rating anxiety scale(SAS).The cognitive function assessment was carried out by using mini-mental state scale (MMSE) and Montreal cognitive assessment (MoCA) Beijing version.Results The patient showed tension,fear,upset,etc.,in hospital,and psychological evaluation results showed that he had the emotions such as anxiety,depression and worry.The mental health was improved after a positive psychological counseling and treatment by using sertraline and olanzapine.Cognitive function assessment results showed that he had moderate-severe cognitive dysfunction for a time,which gradually returned to normal with the improvement of general condition.Conclusions Attention should be paid to the synchronization of physical therapy and psychological treatment in the process of clinical treatment of patients with radiation injury.Improvement to psychological problems is possible using reasonable intervention and treatment,and the cause of neurobehavioral changes still need further research.%目的 结合南京“5.7”192Ir源放射事故患者的救治过程,探讨辐射损伤导致的神经行为及心理健康改变.方法 采用“一对一”、“多对一”的方法密切观察并记录患者精神状态变化,给予心理干预及药物治疗;采用卡特尔16种个性因素测验(16PF)、抑郁自评量表(SDS)、焦虑自评量表(SAS)对患者进行心理测评;采用简短精神状

  8. HDR Brachytherapy Dose Distribution is Influenced by the Metal Material of the Applicator

    OpenAIRE

    Chin-Hui Wu; Yi-Jen Liao; An-Cheng Shiau; Hsin-Yu Lin; Yen-Wan Hsueh Liu; Shih-Ming Hsu

    2015-01-01

    Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicator. The primary purpose of this study was to evaluate the HDR 192Ir dose distribution in cervical can...

  9. High dose-rate brachytherapy source position quality assurance using radiochromic film.

    Science.gov (United States)

    Evans, M D C; Devic, S; Podgorsak, E B

    2007-01-01

    Traditionally, radiographic film has been used to verify high-dose-rate brachytherapy source position accuracy by co-registering autoradiographic and diagnostic images of the associated applicator. Filmless PACS-based clinics that do not have access to radiographic film and wet developers may have trouble performing this quality assurance test in a simple and practical manner. We describe an alternative method for quality assurance using radiochromic-type film. In addition to being easy and practical to use, radiochromic film has some advantages in comparison with traditional radiographic film when used for HDR brachytherapy quality assurance.

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

    Science.gov (United States)

    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 (125)I 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.

  11. SU-E-T-786: Utility of Gold Wires to Optimize Intensity Modulation Capacity of a Novel Directional Modulated Brachytherapy Tandem Applicator for Image Guided Cervical Cancer Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Han, D [University of California, San Diego, La Jolla, CA (United States); Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Safigholi, H; Soliman, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Scanderbeg, D [University of California, San Diego, La Jolla, CA (United States); UCSD Medical Center, La Jolla, CA (United States); Liu, Z [University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To evaluate the impact of using gold wires to differentially fill various channels on plan quality compared with conventional T&R applicator, inside a novel directional modulated brachytherapy (DMBT) tandem applicator for cervical cancer brachytherapy. Materials and Methods: The novel DMBT tandem applicator has a 5.4-mm diameter MR-compatible tungsten alloy enclosed in a 0.3-mm thick plastic tubing that wraps around the tandem. To modulate the radiation intensity, 6 symmetric peripheral holes of 1.3-mm diameter are grooved along the tungsten alloy rod. These grooved holes are differentially filled with gold wires to generate various degrees of directional beams. For example, three different fill patterns of 1) all void, 2) all filled except the hole containing the 192-Ir source, and 3) two adjacent holes to the 192-Ir source filled were Monte Carlo simulated. The resulting 3D dose distributions were imported into an in-house-coded inverse optimization planning system to generate HDR brachytherapy clinical plans for 19 patient cases. All plans generated were normalized to the same D90 as the clinical plans and D2cc doses of OARs were evaluated. Prescription ranged between 15 and 17.5Gy. Results: In general, the plans in case 1) resulted in the highest D2cc doses for the OARs with 11.65±2.30Gy, 7.47±3.05Gy, and 9.84±2.48Gy for bladder, rectum, and sigmoid, respectively, although the differences were small. For the case 2), D2cc doses were 11.61±2.29Gy, 7.41±3.07Gy, and 9.75±2.45Gy, respectively. And, for the case 3), D2cc doses were 11.60±2.28Gy, 7.41±3.05Gy, and 9.74±2.45Gy, respectively. Difference between 1) and 2) cases were small with the average D2cc difference of <0.64%. Difference between 1) and 3) cases were even smaller with the average D2cc difference of <0.1%. Conclusions: There is a minimal clinical benefit by differentially filling grooved holes in the novel DMBT tandem applicator for image guided cervical cancer brachytherapy.

  12. TU-AB-201-08: Rotating Shield High Dose Rate Brachytherapy with 153Gd and 75Se Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, M; Seuntjens, J; Enger, S [McGill University, Montreal, Quebec (Canada); Flynn, R [University of Iowa Hospitals and Clinics, Iowa City, IA (United States)

    2015-06-15

    Purpose: To introduce rotating shield brachytherapy (RSBT) for different cancer sites with {sup 153}Gd and {sup 75}Se isotopes. RSBT is a form of intensity modulated brachytherapy, using shielded rotating catheters to provide a better dose distribution in the tumour while protecting healthy tissue. Methods: BrachySource, a Geant4-based Monte Carlo dose planning system was developed for investigation of RSBT with {sup 153}Gd and {sup 75}Se for different cancer sites. Dose distributions from {sup 153}Gd, {sup 75}Se and {sup 192}Ir isotopes were calculated in a 40 cm radius water phantom by using the microSelectron-v2 source model. The source was placed inside a cylindrical platinum shield with 1.3 mm diameter. An emission window coinciding with the active core of the source was created by removing half (180°) of the wall of the shield. Relative dose rate distributions of the three isotopes were simulated. As a proof of concept, a breast cancer patient originally treated with Mammosite was re-simulated with unshielded {sup 192}Ir and shielded {sup 153}Gd. Results: The source with the lowest energy, {sup 153}Gd, decreased the dose on the shielded side by 91%, followed by {sup 75}Se and {sup 192}Ir with 36% and 16% reduction at 1 cm from the source. The breast cancer patient simulation showed the ability of shielded {sup 153}Gd to spare the chest wall by a 90% dose reduction when only one emission window angle is considered. In this case, fully covering the PTV would require more delivery angles and the chest wall dose reduction would be less, however, the simulation demonstrates the potential of shielded {sup 153}Gd to selectively isolate organs at risk. Conclusion: Introducing {sup 153}Gd and {sup 75}Se sources combined with RSBT will allow escalation of dose in the target volume while maintaining low doses in radiation sensitive healthy tissue. Tailoring treatments to each individual patient by treating all parts of the tumour without over-irradiation of normal

  13. Establishment of Ge-doped optical fibres as thermoluminescence dosimeters for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Issa, Fatma, E-mail: f.issa@surrey.ac.uk [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Radiotherapy, Tripoli Medical Centre (TMC), Tripoli (Libya); Abdul Rahman, A.T. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); School of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi MARA Malaysia, Campus of Negeri Sembilan, 72000 Kuala Pilah (Malaysia); Hugtenburg, Richard P. [Department of Medical Physics and Clinical Engineering, Abertawe Bro Morgannwg UHB and School of Medicine, Swansea University, Swansea, SA2 8PP (United Kingdom); Bradley, David A. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Radiological Sciences, King Saud University, P.O. Box 10219, Riyadh 11432 (Saudi Arabia); Nisbet, Andrew [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, GU2 7XX (United Kingdom)

    2012-07-15

    This study aims to establish the sensitive, {approx}120 {mu}m high spatial resolution, high dynamic range Ge-doped optical fibres as thermoluminescence (TL) dosimeters for brachytherapy dose distribution. This requires investigation to accommodate sensitivity of detection, both for the possibility of short range dose deposition from beta components as well as gamma/x-mediated dose. In-air measurements are made at distances close to radionuclide sources, evaluating the fall off in dose along the transverse axis of {sup 133}Ba and {sup 60}Co radioactive sources, at distances from 2 mm up to 20 mm from their midpoints. Measurements have been compared with Monte Carlo code DOSRZnrc simulations for photon-mediated dose only, agreement being obtained to within 3% and 1% for the {sup 133}Ba and {sup 60}Co sources, respectively. As such, in both cases it is determined that as intended, beta dose has been filtered out by source encapsulation. - Highlights: Black-Right-Pointing-Pointer We seek to establish Ge-doped optical fibres as TLDs for brachytherapy. Black-Right-Pointing-Pointer Dose was evaluated along the central axis of {sup 133}Ba and {sup 60}Co, at 2 mm-20 mm. Black-Right-Pointing-Pointer We verify values using DOSRZnrc Monte Carlo code simulations. Black-Right-Pointing-Pointer Good agreement is between dose measurements and calculation to within 3% and 1%. Black-Right-Pointing-Pointer Methodology is to be used in obtaining doses around {sup 125}I and {sup 192}Ir sources.

  14. Current state of the art brachytherapy treatment planning dosimetry algorithms.

    Science.gov (United States)

    Papagiannis, P; Pantelis, E; Karaiskos, P

    2014-09-01

    Following literature contributions delineating the deficiencies introduced by the approximations of conventional brachytherapy dosimetry, different model-based dosimetry algorithms have been incorporated into commercial systems for (192)Ir brachytherapy treatment planning. The calculation settings of these algorithms are pre-configured according to criteria established by their developers for optimizing computation speed vs accuracy. Their clinical use is hence straightforward. A basic understanding of these algorithms and their limitations is essential, however, for commissioning; detecting differences from conventional algorithms; explaining their origin; assessing their impact; and maintaining global uniformity of clinical practice.

  15. An orthodontic device for retaining implanted radioactive sources during brachytherapy for cancer of the oral cavity

    Energy Technology Data Exchange (ETDEWEB)

    Masuko, Noriko; Katsura, Kouji [Niigata Univ. (Japan). School of Dentistry; Sugita, Tadashi; Sakai, Kunio; Sato, Katsurou; Kawana, Masahiro; Nonomura, Naobumi

    2000-03-01

    An orthodontic retainer was devised to keeping implanted radioactive sources in position and improve the quality of life during brachytherapy for cancer of the oral cavity. The retainer was used in 3 patients with oral cancer, one with cancer of the hard palate, one with cancer of the soft palate, and one with cancer of the floor of mouth, during brachytherapy using {sup 198}Au grains and {sup 137}Cs needles. These patients could speak freely. One with cancer of the hard palate could drink water and ingest semi-liquid food during treatment instead of nasal tube feeding. The plaster dental model obtained while making the retainer proved to be useful for training radiation oncologists. (author)

  16. A case of percutaneous high dose rate brachytherapy for superior pulmonary sulcus tumor

    Energy Technology Data Exchange (ETDEWEB)

    Asakura, Tamaki; Imamura, Masahiro; Murata, Takashi [Kansai Medical Univ., Moriguchi, Osaka (Japan)] [and others

    1996-07-01

    A 64-year-old man with advanced superior pulmonary sulcus tumor suffered severe unrelieved pain even after chemotherapy, external irradiation and hyperthermia. So we planned to introduce a percutaneous high dose rate brachytherapy using the microselectron HDR {sup 192}Ir. With the estimation using the Pain Score, satisfying pain relief was attainable with a combination of the percutaneous high dose rate brachytherapy and conventional treatment. So the percutaneous high dose rate brachytherapy had the possibility to contribute to the alleviation of the pain. (author)

  17. Development of an open source software module for enhanced visualization during MR-guided interstitial gynecologic brachytherapy.

    Science.gov (United States)

    Chen, Xiaojun; Egger, Jan

    2014-01-01

    In 2010, gynecologic malignancies were the 4th leading cause of death in U.S. women and for patients with extensive primary or recurrent disease, treatment with interstitial brachytherapy may be an option. However, brachytherapy requires precise insertion of hollow catheters with introducers into the tumor in order to eradicate the cancer. In this study, a software solution to assist interstitial gynecologic brachytherapy has been investigated and the software has been realized as an own module under (3D) Slicer, which is a free open source software platform for (translational) biomedical research. The developed research module allows on-time processing of intra-operative magnetic resonance imaging (iMRI) data over a direct DICOM connection to a MR scanner. Afterwards follows a multi-stage registration of CAD models of the medical brachytherapy devices (template, obturator) to the patient's MR images, enabling the virtual placement of interstitial needles to assist the physician during the intervention.

  18. CT-guided brachytherapy. A novel percutaneous technique for interstitial ablation of liver malignancies; CT-gesteuerte Brachytherapie. Eine neue perkutane Technik zur interstitiellen Ablation von Lebermetastasen

    Energy Technology Data Exchange (ETDEWEB)

    Ricke, J.; Wust, P.; Stohlmann, A.; Beck, A.; Cho, C.H.; Pech, M.; Wieners, G.; Spors, B.; Werk, M.; Rosner, C.; Haenninen, E.L.; Felix, R. [Klinik fuer Strahlenheilkunde, Charite Virchow-Klinikum, Humboldt-Univ. zu Berlin (Germany)

    2004-05-01

    Purpose: to assess safety and efficacy of CT-guided brachytherapy of liver malignancies. Patients and methods: 21 patients with 21 liver malignancies (19 metastases, two primary liver tumors) were treated with interstitial CT-guided brachytherapy applying a {sup 192}Ir source. In all patients, the use of image-guided thermal tumor ablation such as by radiofrequency or laser-induced thermotherapy (LITT) was impeded either by tumor size {>=} 5 cm in seven, adjacent portal or hepatic vein in ten, or adjacent bile duct bifurcation in four patients. Dosimetry was performed using three-dimensional CT data sets acquired after CT-guided positioning of the brachytherapy catheters. Results: the mean tumor diameter was 4.6 cm (2.5-11 cm). The mean minimal tumor dose inside the tumor margin amounted to 17 Gy (12-20 Gy). The proportion of the liver parenchyma exposed to > 5 gy was 18% (5-39%) of total liver parenchyma minus tumor volume. Nausea and vomiting were observed in six patients after brachytherapy (28%). One patient demonstrated obstructive jaundice due to tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. We commonly encountered asymptomatic increases of liver enzymes. Local control rates after 6 and 12 months were 87% and 70%, respectively. Conclusion: CT-guided brachytherapy is safe and effective. This technique displays broader indications compared to image-guided thermal ablation by radiofrequency or LITT with respect to tumor size or localization. (orig.) [German] Ziel: Analyse der Sicherheit und Effektivitaet CT-gesteuerter Brachytherapie zur Ablation von Lebermalignomen. Patienten und Methodik: 21 Patienten mit 21 Lebermalignomen (19 Metastasen, zwei primaere Lebermalignome) wurden mit perkutaner, CT-gesteuerter interstitieller Brachytherapie mit {sup 192}Ir behandelt. Alle Patienten wiesen Umstaende auf, die eine bildgefuehrte thermische Ablation mit Radiofrequenz oder laserinduzierter Thermotherapie (LITT) einschraenkten

  19. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Directory of Open Access Journals (Sweden)

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  20. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy

    Science.gov (United States)

    Campos, Luciana Tourinho; de Almeida, Carlos Eduardo Veloso

    2015-01-01

    Introduction The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®); it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86), which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21), which is also from BEBIG. Objective and Methods The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the

  1. Low dose rate caesium-137 implant time of intracavitary brachytherapy source of a selected oncology center in Ghana

    OpenAIRE

    John Owusu Banahene; Emmanuel Ofori Darko; Baffour Awuah

    2015-01-01

    Background: The treatment time taken for a radioactive source is found to be very important in intracavitary brachytherapy treatment. The duration of the treatment time depends on the prescribed dose requested to a reference point and the calculated dose rate to the same point. The duration of the treatment time of source is found to depend on the tumour stage. In this work, the treatment time of implant has been calculated for a Caesium-137 low dose rate brachytherapy source at an oncology f...

  2. Novel tools for stepping source brachytherapy treatment planning: Enhanced geometrical optimization and interactive inverse planning

    Energy Technology Data Exchange (ETDEWEB)

    Dinkla, Anna M., E-mail: a.m.dinkla@amc.uva.nl; Laarse, Rob van der; Koedooder, Kees; Petra Kok, H.; Wieringen, Niek van; Pieters, Bradley R.; Bel, Arjan [Department of Radiation Oncology, Academic Medical Center Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ (Netherlands)

    2015-01-15

    Purpose: Dose optimization for stepping source brachytherapy can nowadays be performed using automated inverse algorithms. Although much quicker than graphical optimization, an experienced treatment planner is required for both methods. With automated inverse algorithms, the procedure to achieve the desired dose distribution is often based on trial-and-error. Methods: A new approach for stepping source prostate brachytherapy treatment planning was developed as a quick and user-friendly alternative. This approach consists of the combined use of two novel tools: Enhanced geometrical optimization (EGO) and interactive inverse planning (IIP). EGO is an extended version of the common geometrical optimization method and is applied to create a dose distribution as homogeneous as possible. With the second tool, IIP, this dose distribution is tailored to a specific patient anatomy by interactively changing the highest and lowest dose on the contours. Results: The combined use of EGO–IIP was evaluated on 24 prostate cancer patients, by having an inexperienced user create treatment plans, compliant to clinical dose objectives. This user was able to create dose plans of 24 patients in an average time of 4.4 min/patient. An experienced treatment planner without extensive training in EGO–IIP also created 24 plans. The resulting dose-volume histogram parameters were comparable to the clinical plans and showed high conformance to clinical standards. Conclusions: Even for an inexperienced user, treatment planning with EGO–IIP for stepping source prostate brachytherapy is feasible as an alternative to current optimization algorithms, offering speed, simplicity for the user, and local control of the dose levels.

  3. Assessment of the risks associated with Iodine-125 handling production sources for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Daiane C.B.; Rostelato, Maria Elisa C.; Vicente, Roberto; Zeituni, Carlos A.; Tiezzi, Rodrigo; Costa, Osvaldo L.; Souza, Carla D.; Peleias Junior, Fernando S.; Rodrigues, Bruna T.; Souza, Anderson S.; Batista, Talita Q.; Melo, Emerson R.; Camargo, Anderson R., E-mail: dcsouza@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Karam Junior, Dib, E-mail: dib.karam@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2015-07-01

    In Brazil, prostate cancer is the second most frequent disease, with an estimated 68,800 new cases in 2013. This type of cancer can be treated with brachytherapy, which uses sealed sources of Iodine-125 implanted permanently in the prostate. These sources are currently imported at a high cost, making public treatment in large scale impractical. To reduce costs and to meet domestic demand, the laboratory for production of brachytherapy sources at the Nuclear and Energy Research Institute (IPEN) is currently nationalizing the production of this radioisotope. Iodine is quite volatile making the handling of its radioactive isotopes potentially dangerous. The aim of this paper is to evaluate the risks to which workers are exposed during the production and handling of the sources. The research method consisted initially of a literature review on the toxicity of iodine, intake limits, related physical risks, handling of accidents, generation of radioactive wastes, etc. The results allowed for establishing safety and radioprotection policies in order to ensure efficient and safe production in all stages and the implementation of good laboratory practices. (author)

  4. Dosimetry studies on prototype 241Am sources for brachytherapy.

    Science.gov (United States)

    Nath, R; Gray, L

    1987-06-01

    Sealed sources of 241Am emit primarily 60 keV photons which, because of multiple Compton scattering, produce dose distributions in water that are comparable to those from 226Ra or 137Cs. However, americium gamma rays can be shielded by thin layers of high atomic number materials since the half value layer thickness is only 1/8th of a mm of lead for americium gamma rays as compared to a value of 12 mm for 226Ra gamma rays. This may allow effective in vivo shielding of critical organs, for example; the bladder can be partially shielded by hypaque solution, and the rectum and sigmoid colon by barium sulfate. In addition, the exposure to medical personnel involved in intracavitary application and patient care may be reduced substantially by the use of relatively thin lead aprons and light weight, portable shields. To investigate the feasibility of 241Am sources for intracavitary irradiation, dosimetry studies on prototype 241Am sources have been performed and a computer model for the determination of dose distributions around encapsulated cylindrical sources of 241Am has been developed and tested. Results of dosimetry measurements using ionization chambers, lithium fluoride thermoluminescent dosimeters, a scanning scintillation probe, and film dosimetry, confirm theoretical predictions that these sources can deliver dose rates adequate for intracavitary irradiation. Further dosimetry measurements in simulated clinical situations using lead foils and test tubes filled with hypaque or barium sulfate, confirm the predicted effectiveness of in vivo shielding which can be readily achieved with 241Am sources.

  5. TG-43 U1 based dosimetric characterization of model 67-6520 Cs-137 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Meigooni, Ali S.; Wright, Clarissa; Koona, Rafiq A.; Awan, Shahid B.; Granero, Domingo; Perez-Calatayud, Jose; Ballester, Facundo [Department of Radiation Medicine, North Shore University Hospital, 300 Community Drive, Manhasset, New York 11030 and Department of Radiation Medicine, University of Kentucky Chandler Medical Center, Lexington, Kentucky 40536-0084 (United States); Department of Radiation Medicine, University of Kentucky Chandler Medical Center, Lexington, Kentucky 40536-0084 (United States); Department of Radiation Physics, ERESA, Hospital General Universitario, Avenida Tres Cruces, 2, E-46014 Valencia (Spain); Department of Oncology, Physics Section, ' ' La Fe' ' University Hospital, Avenida Campanar 21, E-46009 Valencia (Spain); Department of Atomic, Molecular and Nuclear Physics, University of Valencia, C/ Dr. Moliner 50, E-46100 Burjassot, Spain and Instituto de Fisica Corpuscular (IFIC), C/ Dr. Moliner 50, E-46100 Burjassot (Spain)

    2009-10-15

    Purpose: Brachytherapy treatment has been a cornerstone for management of various cancer sites, particularly for the treatment of gynecological malignancies. In low dose rate brachytherapy treatments, {sup 137}Cs sources have been used for several decades. A new {sup 137}Cs source design has been introduced (model 67-6520, source B3-561) by Isotope Products Laboratories (IPL) for clinical application. The goal of the present work is to implement the TG-43 U1 protocol in the characterization of the aforementioned {sup 137}Cs source. Methods: The dosimetric characteristics of the IPL {sup 137}Cs source are measured using LiF thermoluminescent dosimeters in a Solid Water phantom material and calculated using Monte Carlo simulations with the GEANT4 code in Solid Water and liquid water. The dose rate constant, radial dose function, and two-dimensional anisotropy function of this source model were obtained following the TG-43 U1 recommendations. In addition, the primary and scatter dose separation (PSS) formalism that could be used in convolution/superposition methods to calculate dose distributions around brachytherapy sources in heterogeneous media was studied. Results: The measured and calculated dose rate constants of the IPL {sup 137}Cs source in Solid Water were found to be 0.930({+-}7.3%) and 0.928({+-}2.6%) cGy h{sup -1} U{sup -1}, respectively. The agreement between these two methods was within our experimental uncertainties. The Monte Carlo calculated value in liquid water of the dose rate constant was {Lambda}=0.948({+-}2.6%) cGy h{sup -1} U{sup -1}. Similarly, the agreement between measured and calculated radial dose functions and the anisotropy functions was found to be within {+-}5%. In addition, the tabulated data that are required to characterize the source using the PSS formalism were derived. Conclusions: In this article the complete dosimetry of the newly designed {sup 137}Cs IPL source following the AAPM TG-43 U1 dosimetric protocol and the PSS

  6. Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Susan; Garcia-Ramirez, Jose; Lu Wei; Myerson, Robert J.; Parikh, Parag [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

    2012-11-15

    Purpose: To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent{sup Registered-Sign} Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Methods: Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. Results: The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy/min while the RT-50 is 10-12 Gy/min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately {+-}5.2%. Conclusions: The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

  7. Calculated neutron air kerma strength conversion factors for a generically encapsulated Cf-252 brachytherapy source

    CERN Document Server

    Rivard, M J; D'Errico, F; Tsai, J S; Ulin, K; Engler, M J

    2002-01-01

    The sup 2 sup 5 sup 2 Cf neutron air kerma strength conversion factor (S sub K sub N /m sub C sub f) is a parameter needed to convert the radionuclide mass (mu g) provided by Oak Ridge National Laboratory into neutron air kerma strength required by modern clinical brachytherapy dosimetry formalisms indicated by Task Group No. 43 of the American Association of Physicists in Medicine (AAPM). The impact of currently used or proposed encapsulating materials for sup 2 sup 5 sup 2 Cf brachytherapy sources (Pt/Ir-10%, 316L stainless steel, nitinol, and Zircaloy-2) on S sub K sub N /m sub C sub f was calculated and results were fit to linear equations. Only for substantial encapsulation thicknesses, did S sub K sub N /m sub C sub f decrease, while the impact of source encapsulation composition is increasingly negligible as Z increases. These findings are explained on the basis of the non-relativistic kinematics governing the majority of sup 2 sup 5 sup 2 Cf neutron interactions. Neutron kerma and energy spectra resul...

  8. Experimental dosimetry of a {sup 32}P catheter-based endovascular brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Piermattei, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Fidanzio, A [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Perrone, F [Azienda Ospedaliera Pisana, UO Fisica Sanitaria, Pisa (Italy); Azario, L [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Grimaldi, L [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Viola, P [Istituto di Fisica, Universita Cattolica S Cuore, Rome (Italy); Capote, R [Dpto Fisiologia Medica y Biofisica, Facultad de Medicina, Universidad de Sevilla, Avda Sanchez Pizjuan 4, E41009 Sevilla (Spain)

    2003-08-07

    The experimental dosimetry in a water phantom of a {sup 32}P linear source, 20 mm in length, used for the brachytherapy of coronary vessels is reported. The source content activity, A, was determined by means of a calibrated well ion-chamber and the value was compared with the contained activity reported in the manufacturer's certification. In this field of brachytherapy dosimetry, radiochromic film supplies a high enough spatial resolution. A highly sensitive radiochromic film, that presents only one active layer, was used in this work for the source dosimetry in a water phantom. The radiochromic film was characterized by electron beams produced by a clinical linac. A Monte Carlo calculation of beta spectra in water at different distances along the source transverse bisector axis allowed to take into account the low dependence of film response from the electron beam energy. The adopted experimental set-up, with the source in its catheter positioned on the film plane inside the water phantom, supplies accurate dosimetric information. The measured dose rate to water per unit of source activity at reference distance, D-dot (r{sub 0}, {theta}{sub 0})/A, in units of cGy s{sup -1} GBq{sup -1}, was in agreement with the value reported in the manufacturer's certification within the experimental uncertainty. The radial dose function, g(r), is in good agreement with the literature data. The anisotropy function F(r, {theta}) is also reported. The analysis of the dose profile obtained at 2 mm from the source longitudinal axis shows that the uniformity is within 10% along 75% of the 20 mm treatment length. The adopted experimental set-up seems to be adequate for the quality control procedure of the dose homogeneity distribution in the water medium.

  9. Dose heterogeneity correction for low-energy brachytherapy sources using dual-energy CT images.

    Science.gov (United States)

    Mashouf, S; Lechtman, E; Lai, P; Keller, B M; Karotki, A; Beachey, D J; Pignol, J P

    2014-09-21

    Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 [Formula: see text] formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions.

  10. Dose heterogeneity correction for low-energy brachytherapy sources using dual-energy CT images

    Science.gov (United States)

    Mashouf, S.; Lechtman, E.; Lai, P.; Keller, B. M.; Karotki, A.; Beachey, D. J.; Pignol, J. P.

    2014-09-01

    Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 × \\text{ICF} formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions.

  11. The feasibility study and characterization of a two-dimensional diode array in “magic phantom” for high dose rate brachytherapy quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, A.; Beeksma, B.; Petasecca, M.; Fuduli, I.; Porumb, C.; Cutajar, D.; Lerch, M. L. F.; Rosenfeld, A. B. [Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 (Australia); Corde, S.; Jackson, M. [Department of Radiation Oncology, Prince of Wales Hospital, New South Wales 2031 (Australia)

    2013-11-15

    Purpose: High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly {sup 192}Ir with an air KERMA strength range between 20 000 and 40 000 U, where 1 U = 1 μGy m{sup 2}/h in air) through applicators directly into the patient's prescribed region of treatment. Due to the obvious ramifications of incorrect treatment while using such an active source, it is essential that there are methods for quality assurance (QA) that can directly and accurately verify the treatment plan and the functionality of the remote afterloader. This paper describes the feasibility study of a QA system for HDR brachytherapy using a phantom based two-dimensional 11 × 11 epitaxial diode array, named “magic phantom.”Methods: The HDR brachytherapy treatment plan is translated to the phantom with two rows of 10 (20 in total) HDR source flexible catheters, arranged above and below the diode array “magic plate” (MP). Four-dimensional source tracking in each catheter is based upon a developed fast iterative algorithm, utilizing the response of the diodes in close proximity to the {sup 192}Ir source, sampled at 100 ms intervals by a fast data acquisition (DAQ) system. Using a {sup 192}Ir source in a solid water phantom, the angular response of the developed epitaxial diodes utilized in the MP and also the variation of the MP response as a function of the source-to-detector distance (SDD) were investigated. These response data are then used by an iterative algorithm for source dwelling position determination. A measurement of the average transit speed between dwell positions was performed using the diodes and a fast DAQ.Results: The angular response of the epitaxial diode showed a variation of 15% within 360°, with two flat regions above and below the detector face with less than 5% variation. For SDD distances of between 5 and 30 mm

  12. The collapsed cone algorithm for (192)Ir dosimetry using phantom-size adaptive multiple-scatter point kernels.

    Science.gov (United States)

    Tedgren, Åsa Carlsson; Plamondon, Mathieu; Beaulieu, Luc

    2015-07-07

    The aim of this work was to investigate how dose distributions calculated with the collapsed cone (CC) algorithm depend on the size of the water phantom used in deriving the point kernel for multiple scatter. A research version of the CC algorithm equipped with a set of selectable point kernels for multiple-scatter dose that had initially been derived in water phantoms of various dimensions was used. The new point kernels were generated using EGSnrc in spherical water phantoms of radii 5 cm, 7.5 cm, 10 cm, 15 cm, 20 cm, 30 cm and 50 cm. Dose distributions derived with CC in water phantoms of different dimensions and in a CT-based clinical breast geometry were compared to Monte Carlo (MC) simulations using the Geant4-based brachytherapy specific MC code Algebra. Agreement with MC within 1% was obtained when the dimensions of the phantom used to derive the multiple-scatter kernel were similar to those of the calculation phantom. Doses are overestimated at phantom edges when kernels are derived in larger phantoms and underestimated when derived in smaller phantoms (by around 2% to 7% depending on distance from source and phantom dimensions). CC agrees well with MC in the high dose region of a breast implant and is superior to TG43 in determining skin doses for all multiple-scatter point kernel sizes. Increased agreement between CC and MC is achieved when the point kernel is comparable to breast dimensions. The investigated approximation in multiple scatter dose depends on the choice of point kernel in relation to phantom size and yields a significant fraction of the total dose only at distances of several centimeters from a source/implant which correspond to volumes of low doses. The current implementation of the CC algorithm utilizes a point kernel derived in a comparatively large (radius 20 cm) water phantom. A fixed point kernel leads to predictable behaviour of the algorithm with the worst case being a source/implant located well within a patient

  13. The collapsed cone algorithm for 192Ir dosimetry using phantom-size adaptive multiple-scatter point kernels

    Science.gov (United States)

    Carlsson Tedgren, Åsa; Plamondon, Mathieu; Beaulieu, Luc

    2015-07-01

    The aim of this work was to investigate how dose distributions calculated with the collapsed cone (CC) algorithm depend on the size of the water phantom used in deriving the point kernel for multiple scatter. A research version of the CC algorithm equipped with a set of selectable point kernels for multiple-scatter dose that had initially been derived in water phantoms of various dimensions was used. The new point kernels were generated using EGSnrc in spherical water phantoms of radii 5 cm, 7.5 cm, 10 cm, 15 cm, 20 cm, 30 cm and 50 cm. Dose distributions derived with CC in water phantoms of different dimensions and in a CT-based clinical breast geometry were compared to Monte Carlo (MC) simulations using the Geant4-based brachytherapy specific MC code Algebra. Agreement with MC within 1% was obtained when the dimensions of the phantom used to derive the multiple-scatter kernel were similar to those of the calculation phantom. Doses are overestimated at phantom edges when kernels are derived in larger phantoms and underestimated when derived in smaller phantoms (by around 2% to 7% depending on distance from source and phantom dimensions). CC agrees well with MC in the high dose region of a breast implant and is superior to TG43 in determining skin doses for all multiple-scatter point kernel sizes. Increased agreement between CC and MC is achieved when the point kernel is comparable to breast dimensions. The investigated approximation in multiple scatter dose depends on the choice of point kernel in relation to phantom size and yields a significant fraction of the total dose only at distances of several centimeters from a source/implant which correspond to volumes of low doses. The current implementation of the CC algorithm utilizes a point kernel derived in a comparatively large (radius 20 cm) water phantom. A fixed point kernel leads to predictable behaviour of the algorithm with the worst case being a source/implant located well within a patient

  14. Study on the method to scale 192ir radioactivity%192Ir源两种刻度方法的比较

    Institute of Scientific and Technical Information of China (English)

    王晓红; 徐利明; 张沪生

    2000-01-01

    purpose: To calibrate the accurate value of 192Ir radioactivity again. materials and methods: To measure the dose rate of radioactivity in water and at air by ion chamber. results: To scale the activity of 192Ir radioactivity by air Kerma is agreement to the scaling method according to the JJG 773-92. conclusion: The investigation demonstrates that the accurate value of 192Ir radioactivity can be calibrated by the method of air Kerma.%目的:通过对192Ir源的再次刻度,校准源活度的精确值。材料与方法:用电离室法,分别测量源在水介质中和自由空气中的照射量率。结果:两种方法在刻度192Ir源活性上得到的结果是一致的。结论:利用空气比释动能法可以对192Ir源进行精确刻度。

  15. Investigations into the Optimization of Multi-Source Strength Brachytherapy Treatment Procedures

    CERN Document Server

    Henderson, D L; Yoo, S

    2002-01-01

    The goal of this project is to investigate the use of multi-strength and multi-specie radioactive sources in permanent prostate implant brachytherapy. In order to fulfill the requirement for an optimal dose distribution, the prescribed dose should be delivered to the target in a nearly uniform dose distribution while simultaneously sparing sensitive structures. The treatment plan should use a small number of needles and sources while satisfying the treatment requirements. The hypothesis for the use of multi-strength and/or multi-specie sources is that a better treatment plan using fewer sources and needles could be obtained than by treatment plans using single-strength sources could reduce the overall number of sources used for treatment. We employ a recently developed greedy algorithm based on the adjoint concept as the optimization search engine. The algorithm utilizes and ''adjoint ratio'', which provides a means of ranking source positions, as the pseudo-objective function. It ha s been shown that the gre...

  16. Dosimetric comparison between three dimensional treatment planning system, Monte Carlo simulation and gel dosimetry in nasopharynx phantom for high dose rate brachytherapy

    Directory of Open Access Journals (Sweden)

    Zeynab Fazli

    2013-01-01

    Full Text Available Purpose: For the treatment of nasopharnx carcinoma (NPC using brachytherapy methods and high-energy photon sources are common techniques. In the common three dimensional (3D treatments planning, all of the computed tomography images are assumed homogeneous. This study presents the results of Monte Carlo calculations for non-homogeneous nasopharynx phantom, MAGICA normoxic gel dosimetry and 3D treatment planning system (TPS. Materials and Methods: The head phantom was designed with Plexiglas cylinder, head bone, and nasopharynx brachytherapy silicon applicator. For the simulations, version 5 of the Monte Carlo N-particle transport code (MCNP5 was used. 3D treatment planning was performed in Flexiplan software. A normoxic radiosensitive polymer gel was fabricated under normal atmospheric conditions and poured into test tubes (for calibration curve and the head phantom. In addition, the head phantom was irradiated with Flexitron afterloader brachytherapy machine with 192 Ir source. To obtain calibration curves, 11 dosimeters were irradiated with dose range of 0-2000 cGy. Evaluations of dosimeters were performed on 1.5T scanner. Results: Two-dimensional iso-dose in coronal plan at distances of z = +0.3, –0.3 cm was calculated. There was a good accordance between 3D TPS and MCNP5 simulation and differences in various distances were between 2.4% and 6.1%. There was a predictable accordance between MAGICA gel dosimetry and MCNP5 simulation and differences in various distances were between 5.7% and 7.4%. Moreover, there was an acceptable accordance between MAGICA gel dosimetry and MCNP5 data and differences in various distances were between 5.2% and 9.4%. Conclusion: The sources of differences in this comparison are divided to calculations variation and practical errors that was added in experimental dosimetry. The result of quality assurance of nasopharynx high dose rate brachytherapy is consistent with international standards.

  17. Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Peleias Junior, Fernando S.; Zeituni, Carlos A.; Rostelato, Maria Elisa C.M., E-mail: fernandopeleias@gmail.com, E-mail: czeituni@ipen.br, E-mail: elisaros@ipen.br; and others

    2013-07-01

    Cancer is a term used generically to represent a group of more than 100 illnesses, including malignant tumors from different locations. According to World Health Organization (WHO), is a leading cause of death worldwide, accounted for 7.6 million deaths. Prostate cancer is the sixth most common type in the world, representing about 10% of all cases of cancer and its treatment may be by surgery, radiotherapy or even vigilant observation. A method of radiotherapy which has been extensively used in the early and intermediate stages of the illness is brachytherapy, where radioactive seeds are placed inside or next to the area requiring treatment, which reduces the probability of unnecessary damage to surrounding healthy tissues. Currently, the radioactive isotope Iodine-125, adsorbed on silver substrate, is one of the most used in prostate brachytherapy. The present study compares several deposition methods of radioactive Iodine on silver substrate, in order to choose the most suitable one to be implemented at the laboratory of radioactive sources production of IPEN. The methodology used was chosen based on the available infrastructure and experience of the researchers of the institute. Therefore, Iodine-131 was used for testing (same chemical behavior of Iodine -125). Three methods were selected: method 1 (test based on electrodeposition method, developed by David Kubiatowicz) which presented efficiency of 65.16% ; method 2 (chemical reaction based on the method developed by David Kubiatowicz -HCl) which presented efficiency of 70.80%; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80% . Based on the results, the second method is the suggested one to be implemented at the laboratory of radioactive sources production of IPEN. (author)

  18. Monte Carlo calculations and experimental measurements of dosimetric parameters of the IRA-103Pd brachytherapy source.

    Science.gov (United States)

    Sadeghi, Mahdi; Raisali, Gholamreza; Hosseini, S Hamed; Shavar, Arzhang

    2008-04-01

    This article presents a brachytherapy source having 103Pd adsorbed onto a cylindrical silver rod that has been developed by the Agricultural, Medical, and Industrial Research School for permanent implant applications. Dosimetric characteristics (radial dose function, anisotropy function, and anisotropy factor) of this source were experimentally and theoretically determined in terms of the updated AAPM Task group 43 (TG-43U1) recommendations. Monte Carlo simulations were used to calculate the dose rate constant. Measurements were performed using TLD-GR200A circular chip dosimeters using standard methods employing thermoluminescent dosimeters in a Perspex phantom. Precision machined bores in the phantom located the dosimeters and the source in a reproducible fixed geometry, providing for transverse-axis and angular dose profiles over a range of distances from 0.5 to 5 cm. The Monte Carlo N-particle (MCNP) code, version 4C simulation techniques have been used to evaluate the dose-rate distributions around this model 103Pd source in water and Perspex phantoms. The Monte Carlo calculated dose rate constant of the IRA-103Pd source in water was found to be 0.678 cGy h(-1) U(-1) with an approximate uncertainty of +/-0.1%. The anisotropy function, F(r, theta), and the radial dose function, g(r), of the IRA- 103Pd source were also measured in a Perspex phantom and calculated in both Perspex and liquid water phantoms.

  19. Monte Carlo modeling of 60 Co HDR brachytherapy source in water and in different solid water phantom materials

    Directory of Open Access Journals (Sweden)

    Sahoo S

    2010-01-01

    Full Text Available The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source-detector distance. A solid phantom can be precisely machined and hence source-detector distances can be accurately determined. In the present study, four different solid phantom materials such as polymethylmethacrylate (PMMA, polystyrene, Solid Water, and RW1 are modeled using the Monte Carlo methods to investigate the influence of phantom material on dose rate distributions of the new model of BEBIG 60 Co brachytherapy source. The calculated dose rate constant is 1.086 ± 0.06% cGy h−1 U−1 for water, PMMA, polystyrene, Solid Water, and RW1. The investigation suggests that the phantom materials RW1 and Solid Water represent water-equivalent up to 20 cm from the source. PMMA and polystyrene are water-equivalent up to 10 cm and 15 cm from the source, respectively, as the differences in the dose data obtained in these phantom materials are not significantly different from the corresponding data obtained in liquid water phantom. At a radial distance of 20 cm from the source, polystyrene overestimates the dose by 3% and PMMA underestimates it by about 8% when compared to the corresponding data obtained in water phantom.

  20. A Comparison of the Dosimetric Parameters of Cs-137 Brachytherapy Source in Different Tissues with Water Using Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    Sedigheh Sina

    2012-03-01

    Full Text Available Introduction After the publication of Task Group number 43 dose calculation formalism by the American Association of Physicists in Medicine (AAPM, this method has been known as the most common dose calculation method in brachytherapy treatment planning. In this formalism, the water phantom is introduced as the reference dosimetry phantom, while the attenuation coefficient of the sources in the water phantom is different from that of different tissues. The purpose of this study is to investigate the effects of the phantom materials on the TG-43 dosimetery parameters of the Cs-137 brachytherapy source using MCNP4C Monte Carlo code. Materials and Methods In this research, the Cs-137 (Model Selectron brachytherapy source was simulated in different phantoms (bone, soft tissue, muscle, fat, and the inhomogeneous phantoms of water/bone of volume 27000 cm3 using MCNP4C Monte Carlo code. *F8 tally was used to obtain the dose in a fine cubical lattice. Then the TG-43 dosimetry parameters of the brachytherapy source were obtained in water phantom and compared with those of different phantoms. Results The percentage difference between the radial dose function g(r of bone and the g(r of water phantom, at a distance of 10 cm from the source center is 20%, while such differences are 1.7%, 1.6% and 1.1% for soft tissue, muscle, and fat, respectively. The largest difference of the dose rate constant of phantoms with those of water is 4.52% for the bone phantom, while the differences for soft tissue, muscle, and fat are 1.18%, 1.27%, and 0.18%, respectively. The 2D anisotropy function of the Cs-137 source for different tissues is identical to that of water. Conclusion The results of the simulations have shown that dose calculation in water phantom would introduce errors in the dose calculation around brachytherapy sources. Therefore, it is suggested that the correction factors of different tissues be applied after dose calculation in water phantoms, in order to

  1. Material-specific Conversion Factors for Different Solid Phantoms Used in the Dosimetry of Different Brachytherapy Sources

    Directory of Open Access Journals (Sweden)

    Sedigheh Sina

    2015-07-01

    Full Text Available Introduction Based on Task Group No. 43 (TG-43U1 recommendations, water phantom is proposed as a reference phantom for the dosimetry of brachytherapy sources. The experimental determination of TG-43 parameters is usually performed in water-equivalent solid phantoms. The purpose of this study was to determine the conversion factors for equalizing solid phantoms to water. Materials and Methods TG-43 parameters of low- and high-energy brachytherapy sources (i.e., Pd-103, I-125 and Cs-137 were obtained in different phantoms, using Monte Carlo simulations. The brachytherapy sources were simulated at the center of different phantoms including water, solid water, poly(methyl methacrylate, polystyrene and polyethylene. Dosimetric parameters such as dose rate constant, radial dose function and anisotropy function of each source were compared in different phantoms. Then, conversion factors were obtained to make phantom parameters equivalent to those of water. Results Polynomial coefficients of conversion factors were obtained for all sources to quantitatively compare g(r values in different phantom materials and the radial dose function in water. Conclusion Polynomial coefficients of conversion factors were obtained for all sources to quantitatively compare g(r values in different phantom materials and the radial dose function in water.

  2. Dosimetric parameters of palladium-103 brachytherapy source with Monte Carlo simulation

    Institute of Scientific and Technical Information of China (English)

    WANG JianHua; LIU Wei; XU XunJiang; GU JiaHui; CAI Jun; HUA ZhengDong; XU JiaQiang

    2008-01-01

    Before clinical application of a new source, the dosimetric parameters of the source should be accu-rately determined. This work is dedicated to the Monte Carlo method to calculate dosimetric parameters as recommended by the American Association of Physicists in Medicine (AAPM) TG-43 guidelines for model ADVANTAGETM palladium-103 source and, through comparison with data from another published report for the same source, presents a suggested dataset for clinical applications. From these calcula-tions, tables are presented for the radial dose function and the anisotropy function of palladium-103 brachytherapy source. The dose rate constants are found to be 0.671 (cGyh-1U-1) in liquid water and 0.673 (cGyh-1U-1) in Solid WaterTM. And the anisotropy constants in liquid water and Solid WaterTM are found to be 0.864 and 0.865 respectively. Comparison with the previous study shows that our results of dosimetric parameters are in good agreement with those measured and calculated by Meigooni et al. (2006) both in Water and Solid WaterTM.

  3. Methodology study for fixation of radioactive iodine in polymeric substrate for brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruna T.; Rostelato, Maria Elisa C.M.; Souza, Carla D.; Tiezzi, Rodrigo; Souza, Daiane B. de; Benega, Marcos A.G.; Souza, Anderson S. de; Peleias Junior, Fernando S.; Zeituni, Calos A.; Fernandes, Vagner; Melo, Emerson Ronaldo de; Camargo, Anderson Rogerio de, E-mail: bteigarodrigues@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Cancer is now the second leading cause of death by disease in several countries, including Brazil. Prostate cancer is the most common among men. Brachytherapy is a modality of radiotherapy in which radioactive seeds are placed inside or in contact with the organ to be treated. The most widely used radioisotope in prostate brachytherapy is Iodine-125 which is presented fixated on a silver substrate that is subsequently placed inside a titanium capsule. A large dose of radiation is released only in the targeted tumor protecting healthy surrounding tissues. The technique requires the application of 80 - 120 seeds per patient. The implants of seeds have low impact and non-surgical procedures. Most patients can return to normal life within three days with little or no pain. This work proposes an alternative to the seeds that have already been developed, in order to reduce the cost by obtaining a better efficiency on fixing the radioactive iodine onto the epoxy resin. Methods have been developed to perform the fixation of Iodine-125 onto polymeric substrates. The parameters analyzed were the immersion time, type of static or dynamic reaction, concentration of the adsorption solution, the specific activity of the radioactive source, the need for carrier and chemical form of the radioactive Iodine. These experiments defined the most effective method to fixate the Iodine onto the polymeric material (epoxy resin), the Iodine activity in the polymeric substrate, the activity of the distribution of variation in a plot of polymeric cores and the efficiency of the epoxy resin to seal the seed. (author)

  4. Determination of dosimetric parameters for shielded 153Gd source in prostate cancer brachytherapy

    Science.gov (United States)

    Ghorbani, Mahdi; Ghatei, Najmeh; Mehrpouyan, Mohammad; Meigooni, Ali S.; Shahraini, Ramin

    2017-01-01

    Abstract Background Interstitial rotating shield brachytherapy (I-RSBT) is a recently developed method for treatment of prostate cancer. In the present study TG-43 dosimetric parameters of a 153Gd source were obtained for use in I-RSBT. Materials and methods A 153Gd source located inside a needle including a Pt shield and an aluminum window was simulated using MCNPX Monte Carlo code. Dosimetric parameters of this source model, including air kerma strength, dose rate constant, radial dose function and 2D anisotropy function, with and without the shields were calculated according to the TG-43 report. Results The air kerma strength was found to be 6.71 U for the non-shielded source with 1 GBq activity. This value was found to be 0.04 U and 6.19 U for the Pt shield and Al window cases, respectively. Dose rate constant for the non-shielded source was found to be 1.20 cGy/(hU). However, for a shielded source with Pt and aluminum window, dose rate constants were found to be 0.07 cGy/(hU) and 0.96 cGy/(hU), on the shielded and window sides, respectively. The values of radial dose function and anisotropy function were tabulated for these sources. Additionally, isodose curves were drawn for sources with and without shield, in order to evaluate the effect of shield on dose distribution. Conclusions Existence of the Pt shield may greatly reduce the dose to organs at risk and normal tissues which are located toward the shielded side. The calculated air kerma strength, dose rate constant, radial dose function and 2D anisotropy function data for the 153Gd source for the non-shielded and the shielded sources can be used in the treatment planning system (TPS). PMID:28265239

  5. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources

    Directory of Open Access Journals (Sweden)

    Vandana S

    2010-01-01

    Full Text Available Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR -1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR of a reference 137 Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference 137 Cs brachytherapy source (CDCSJ5, and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA, Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference 137 Cs source. All required correction factors were applied in the calculation of the RAKR of the 137 Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within ±0.5% for about three years after calibration/recalibration. However, it shows deviations larger than ±0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  6. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources.

    Science.gov (United States)

    Vandana, S; Sharma, S D

    2010-04-01

    Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR)-1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR) of a reference (137)Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference (137)Cs brachytherapy source (CDCSJ5), and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA), Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference (137)Cs source. All required correction factors were applied in the calculation of the RAKR of the (137)Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within +/-0.5% for about three years after calibration/recalibration. However, it shows deviations larger than +/-0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  7. Effectiveness Evaluation of Skin Covers against Intravascular Brachytherapy Sources Using VARSKIN3 Code

    Directory of Open Access Journals (Sweden)

    Baghani HR

    2013-12-01

    Full Text Available Background and Objective: The most common intravascular brachytherapy sources include 32P, 188Re, 106Rh and 90Sr/90Y. In this research, skin absorbed dose for different covering materials in dealing with these sources were evaluated and the best covering material for skin protection and reduction of absorbed dose by radiation staff was recognized and recommended. Method: Four materials including polyethylene, cotton and two different kinds of plastic were proposed as skin covers and skin absorbed dose at different depths for each kind of the materials was calculated separately using the VARSKIN3 code. Results: The results suggested that for all sources, skin absorbed dose was minimized when using polyethylene. Considering this material as skin cover, maximum and minimum doses at skin surface were related to 90Sr/90Y and 106Rh, respectively. Conclusion: polyethylene was found the most effective cover in reducing skin dose and protecting the skin. Furthermore, proper agreement between the results of VARSKIN3 and other experimental measurements indicated that VRASKIN3 is a powerful tool for skin dose calculations when working with beta emitter sources. Therefore, it can be utilized in dealing with the issue of radiation protection.

  8. SU-F-BRA-12: End-User Oriented Tools and Procedures for Testing Brachytherapy TPSs Employing MBDCAs

    Energy Technology Data Exchange (ETDEWEB)

    Peppa, V; Pappas, E; Lahanas, V; Pantelis, E; Papagiannis, P [Medical Physics Laboratory, Medical School, University of Athens (Greece)

    2015-06-15

    Purpose: To develop user-oriented tools for commissioning and dosimetry testing of {sup 192}Ir brachytherapy treatment planning systems (TPSs) employing model based dose calculation algorithms (MBDCAs). Methods: A software tool (BrachyGuide) has been developed for the automatic generation of MCNP6 input files from any CT based plan exported in DICOM RT format from Elekta and Varian TPSs. BrachyGuide also facilitates the evaluation of imported Monte Carlo (MC) and TPS dose distributions in terms of % dose differences and gamma index (CT overlaid colormaps or relative frequency plots) as well as DVHs and related indices. For users not equipped to perform MC, a set of computational models was prepared in DICOM format, accompanied by treatment plans and corresponding MCNP6 generated reference data. BrachyGuide can then be used to compare institutional and reference data as per TG186. The model set includes a water sphere with the MBDCA WG {sup 192}Ir source placed centrically and in two eccentric positions, a water sphere with cubic bone and lung inhomogeneities and a five source dwells plan, and a patient equivalent model with an Accelerated Partial Breast Irradiation (APBI) plan. Results: The tools developed were used for the dosimetry testing of the Acuros and ACE MBDCAs implemented in BrachyVision v.13 and Oncentra Brachy v.4.5, respectively. Findings were consistent with previous results in the literature. Besides points close to the source dwells, Acuros was found to agree within type A uncertainties with the reference MC results. Differences greater than MC type A uncertainty were observed for ACE at distances >5cm from the source dwells and in bone. Conclusion: The tools developed are efficient for brachytherapy MBDCA planning commissioning and testing. Since they are appropriate for distribution over the web, they will be put at the AAPM WG MBDCA’s disposal. Research co-financed by the ESF and Greek funds. NSRF operational Program: Education and Lifelong

  9. Dosimetric evaluation of newly developed well-type ionization chamber for use in the calibration of brachytherapy sources

    Directory of Open Access Journals (Sweden)

    Sathiyan Saminathan

    2016-01-01

    Full Text Available The well-type ionization chamber has been designed for convenient use in brachytherapy source strength calibration. The chamber has a volume of 240 cm 3 , weight of 2.5 kg, and is open to atmospheric conditions. The well-type ionization chamber dosimetric characteristics such as leakage current, stability, scattering effect, ion collection efficiency, and nominal response with energy were studied. The evaluated dosimetric characteristics of well-type ionization chamber were compared with two other commercially available well-type ionization chambers. The study shows that the newly developed well-type ionization chamber is reliable for air-kerma strength calibration. The results obtained confirm that this chamber can be used for the calibrations of high-dose rate brachytherapy sources.

  10. Dosimetric evaluation of newly developed well-type ionization chamber for use in the calibration of brachytherapy sources.

    Science.gov (United States)

    Saminathan, Sathiyan; Godson, Henry Finlay; Ponmalar, Retna; Manickam, Ravikumar; Mazarello, James

    2016-01-01

    The well-type ionization chamber has been designed for convenient use in brachytherapy source strength calibration. The chamber has a volume of 240 cm(3), weight of 2.5 kg, and is open to atmospheric conditions. The well-type ionization chamber dosimetric characteristics such as leakage current, stability, scattering effect, ion collection efficiency, and nominal response with energy were studied. The evaluated dosimetric characteristics of well-type ionization chamber were compared with two other commercially available well-type ionization chambers. The study shows that the newly developed well-type ionization chamber is reliable for air-kerma strength calibration. The results obtained confirm that this chamber can be used for the calibrations of high-dose rate brachytherapy sources.

  11. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, E.; Sosa, M. A.; Gil V, A. [Universidad de Guanajuato, Division de Ciencias e Ingenierias, Av. Insurgentes 2354, 37150 Leon, Guanajuato (Mexico); Monzon, E., E-mail: eric_1985@fisica.ugto.mx [IMSS, Unidad Medica de Alta Especialidad No. 1, Av. Adolfo Lopez Mateos 1813, 37340 Leon, Guanajuato (Mexico)

    2015-10-15

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  12. Low dose rate caesium-137 implant time of intracavitary brachytherapy source of a selected oncology center in Ghana

    Directory of Open Access Journals (Sweden)

    John Owusu Banahene

    2015-01-01

    Full Text Available Background: The treatment time taken for a radioactive source is found to be very important in intracavitary brachytherapy treatment. The duration of the treatment time depends on the prescribed dose requested to a reference point and the calculated dose rate to the same point. The duration of the treatment time of source is found to depend on the tumour stage. In this work, the treatment time of implant has been calculated for a Caesium-137 low dose rate brachytherapy source at an oncology facility in Ghana. Objective: The objective was to determine how the treatment time of tumours depends on the dose rate to the reference point prescribed by the Oncologists and the dose rate determined by the dosimetrists at the facility. Materials and Method: Depending upon the stage of the cancer, the Oncologist determines the type of treatment modality, source configuration for the cancer patient and positions of both tandem and ovoids in the cervix. Depending also on the tumour stage, two orthogonal radiographic X-ray films are taken using a simulator machine. The treatment machine used in the study is AMRA-Curietron. The maximum activity of the source was 259GBq. It has five channels which is a manual remote afterloader. In clinical practice, the treatment time t is very short(only some few days for such low dose rate brachytherapy source like Cs-137 which lasts only for some few days in comparison with the half life of the Cs-137 source. The mathematical equation for the calculation of treatment time is written as t=D/D. Hence t is the treatment time of the radioactive source of patients undergoing intracavitary brachytherapy treatment, D is prescribed dose to a reference point and D is the dose rate to the same reference point. Results: The calculated treatment time of the Cs-137 brachytherapy source for different source arrangements or channels used in clinical practice at the brachytherapy Centre have been determined. Also provided, are the

  13. Dosimetry parameters calculation of two commercial iodine brachytherapy sources using SMARTEPANTS with EPDL97 library

    Directory of Open Access Journals (Sweden)

    Navid Ayoobian

    2012-01-01

    Conclusion: The good agreement between the results of this study and previous reports and high computational speed suggest that SMARTEPANTS could be extended to a real-time treatment planning system for 125 I brachytherapy treatments.

  14. Theoretical and experimental determination of dosimetric characteristics for ADVANTAGE{sup TM} Pd-103 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Meigooni, Ali S. [Department of Radiation Medicine, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536 (United States)]. E-mail: alimeig@uky.edu; Dini, Sharifeh A. [Department of Radiation Medicine, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536 (United States); Awan, Shahid B. [Department of Radiation Medicine, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536 (United States); Dou, Kai [Department of Radiation Medicine, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536 (United States); Koona, Rafiq A. [Department of Radiation Medicine, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536 (United States)

    2006-08-15

    ADVANTAGE{sup TM} Pd-103 brachytherapy source has been recently introduced by IsoAid{sup TM} for prostate permanent implants. Dosimetric characteristics (Dose rate constant, radial dose function, 2D-, and 1D-anisotropy functions) of this source model have been determined using both theoretical and experimental methods, following the updated TG-43U1 protocol. Derivation of the dose rate constant was based on recent NIST WAFAC calibration performed in accordance with the 1999 Standards. Measurements were performed in Solid Water{sup TM} using LiF TLD chips and the theoretical calculations were performed in Solid Water{sup TM} and liquid water phantom materials using PTRAN Monte Carlo code. The results of the Monte Carlo simulation have shown a dose rate constant of 0.69 cGy h{sup -1} U{sup -1} in liquid water and 0.67 cGy h{sup -1} U{sup -1} in Solid Water{sup TM} medium. The measured dose rate constant in Solid Water{sup TM} was found to be 0.68{+-}8% cGy h{sup -1} U{sup -1}, which is in a good agreement (within {+-}5%) to the Monte Carlo simulated data. The 2D- and 1D-anisotropy functions of the ADVANTAGE{sup TM} Pd-103 source were calculated for radial distances ranging from 0.5 to 5.0 cm. Radial dose function was determined for radial distances ranging from 0.2 to 8.0 cm using line source approximation. All these calculations are based on L {sub eff} equal to 3.61 cm, calculated following TG-43U1 recommendations. The tabulated data for 2D-anisotropy function, 1D-anisotropy function, dose rate constant and radial dose function have been produced for clinical application of this source model.

  15. Effect of Uniform and Non-uniform High-z Nanoparticles Distribution in Tumor Volume on Dose Enhancement Factor During 192Ir Brachytherapy

    Directory of Open Access Journals (Sweden)

    M Zabihzadeh

    2013-12-01

    Conclusion: increase of atomic number and concentrations of NPs enhance the absorbed dose due to increased possibility of photoelectric phenomena. Non-uniform distribution of NPs underestimated dose compared to uniform distribution; therefore, considering accurate NPs distribution inside the tumor volume is crucial to calculation of dose enhancement. Targeted labeling of NPs for the maximum absorption by tumor and for the minimal penetration into peripheral tissues has potential to increase radiation therapeutic ratio.

  16. Dose calculation formalisms and consensus dosimetry parameters for intravascular brachytherapy dosimetry: recommendations of the AAPM Therapy Physics Committee Task Group No. 149.

    Science.gov (United States)

    Chiu-Tsao, Sou-Tung; Schaart, Dennis R; Soares, Christopher G; Nath, Ravinder

    2007-11-01

    Since the publication of AAPM Task Group 60 report in 1999, a considerable amount of dosimetry data for the three coronary brachytherapy systems in use in the United States has been reported. A subgroup, Task Group 149, of the AAPM working group on Special Brachytherapy Modalities (Bruce Thomadsen, Chair) was charged to develop recommendations for dose calculation formalisms and the related consensus dosimetry parameters. The recommendations of this group are presented here. For the Cordis 192Ir and Novoste 90Sr/90Y systems, the original TG-43 formalism in spherical coordinates should be used along with the consensus values of the dose rate constant, geometry function, radial dose function, and anisotropy function for the single seeds. Contributions from the single seeds should be added linearly for the calculation of dose distributions from a source train. For the Guidant 32P wire system, the modified TG-43 formalism in cylindrical coordinates along with the recommended data for the 20 and 27 mm wires should be used. Data tables for the 6, 10, 14, 18, and 22 seed trains of the Cordis system, 30, 40, and 60 mm seed trains of the Novoste system, and the 20 and 27 mm wires of the Guidant system are presented along with our rationale and methodology for selecting the consensus data. Briefly, all available datasets were compared with each other and the consensus dataset was either an average of available data or the one obtained from the most densely populated study; in most cases this was a Monte Carlo calculation.

  17. A novel optical calorimetry dosimetry approach applied to an HDR Brachytherapy source

    Science.gov (United States)

    Cavan, A.; Meyer, J.

    2013-06-01

    The technique of Digital Holographic Interferometry (DHI) is applied to the measurement of radiation absorbed dose distribution in water. An optical interferometer has been developed that captures the small variations in the refractive index of water due to the radiation induced temperature increase ΔT. The absorbed dose D is then determined with high temporal and spatial resolution using the calorimetric relation D=cΔT (where c is the specific heat capacity of water). The method is capable of time resolving 3D spatial calorimetry. As a proof-of-principle of the approach, a prototype DHI dosimeter was applied to the measurement of absorbed dose from a High Dose Rate (HDR) Brachytherapy source. Initial results are in agreement with modelled doses from the Brachyvision treatment planning system, demonstrating the viability of the system for high dose rate applications. Future work will focus on applying corrections for heat diffusion and geometric effects. The method has potential to contribute to the dosimetry of diverse high dose rate applications which require high spatial resolution such as microbeam radiotherapy (MRT) or small field proton beam dosimetry but may potentially also be useful for interface dosimetry.

  18. Dependence with air density of the response of the PTW SourceCheck ionization chamber for low energy brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Tornero-López, Ana M.; Guirado, Damián; Ruiz-Arrebola, Samuel [Servicio de Radiofísica y Protección Radiológica, Hospital Universitario San Cecilio, E-18012 Granada (Spain); Perez-Calatayud, Jose [Servicio de Radioterapia, Unidad de Radiofísica, Hospital Universitario y Politécnico La Fe, E-46026 Valencia (Spain); Simancas, Fernando; Lallena, Antonio M. [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain); Gazdic-Santic, Maja [Department of Medical Physics and Radiation Safety, Clinical Centre of Sarajevo University, 71000 Sarajevo (Bosnia and Herzegovina)

    2013-12-15

    Purpose: Air-communicating well ionization chambers are commonly used to assess air kerma strength of sources used in brachytherapy. The signal produced is supposed to be proportional to the air density within the chamber and, therefore, a density-independent air kerma strength is obtained when the measurement is corrected to standard atmospheric conditions using the usual temperature and pressure correction factor. Nevertheless, when assessing low energy sources, the ionization chambers may not fulfill that condition and a residual density dependence still remains after correction. In this work, the authors examined the behavior of the PTW 34051 SourceCheck ionization chamber when measuring the air kerma strength of {sup 125}I seeds.Methods: Four different SourceCheck chambers were analyzed. With each one of them, two series of measurements of the air kerma strength for {sup 125}I selectSeed{sup TM} brachytherapy sources were performed inside a pressure chamber and varying the pressure in a range from 747 to 1040 hPa (560 to 780 mm Hg). The temperature and relative humidity were kept basically constant. An analogous experiment was performed by taking measurements at different altitudes above sea level.Results: Contrary to other well-known ionization chambers, like the HDR1000 PLUS, in which the temperature-pressure correction factor overcorrects the measurements, in the SourceCheck ionization chamber they are undercorrected. At a typical atmospheric situation of 933 hPa (700 mm Hg) and 20 °C, this undercorrection turns out to be 1.5%. Corrected measurements show a residual linear dependence on the density and, as a consequence, an additional density dependent correction must be applied. The slope of this residual linear density dependence is different for each SourceCheck chamber investigated. The results obtained by taking measurements at different altitudes are compatible with those obtained with the pressure chamber.Conclusions: Variations of the altitude and

  19. Automation system for quality control in manufacture of iodine-125 sealed sources used in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir L.; Feher, Anselmo; Sprenger, Francisco E.; Rostellato, Maria E.C.M.; Moura, Joao A.; Costa, Osvaldo L.; Calvo, Wilson A.P., E-mail: somessar@ipen.b, E-mail: afeher@ipen.b, E-mail: sprenger@ipen.b, E-mail: elisaros@ipen.b, E-mail: olcosta@ipen.b, E-mail: wapcalvo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The objective of this work is to develop an automation system for Quality Control in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding. These sources, also known as Iodine-125 seeds are used, successfully, in the treatment of cancer by brachytherapy, with low-dose rates. Each small seed is composed of a welded titanium capsule with 0.8 mm diameter and 4.5 mm in length, containing Iodine-125 adsorbed on an internal silver wire. The seeds are implanted in the human prostate to irradiate the tumor and treat the cancerous cells. The technology to automate the quality control system in the manufacture of Iodine-125 seeds consists in developing and associate mechanical parts, electronic components and pneumatic circuits to control machines and processes. The automation technology for Iodine-125 seed production developed in this work employs programmable logic controller, step motors, drivers of control, electrical-electronic interfaces, photoelectric sensors, interfaces of communication and software development. Industrial automation plays an important role in the production of Iodine-125 seeds, with higher productivity and high standard of quality, facilitating the implementation and operation of processes with good manufacturing practices. Nowadays, the Radiation Technology Center at IPEN-CNEN/SP imports and distributes 36,000 Iodine-125 seeds per year for clinics and hospitals in the whole country. However, the Brazilian potential market is of 8,000 Iodine-125 seeds per month. Therefore, the local production of these radioactive seeds has become a priority for the Institute, aiming to reduce the price and increase the supply to the population in Brazil. (author)

  20. Overview on the dosimetric uncertainty analysis for photon-emitting brachytherapy sources, in the light of the AAPM Task Group No 138 and GEC-ESTRO report

    Science.gov (United States)

    DeWerd, Larry A.; Venselaar, Jack L. M.; Ibbott, Geoffrey S.; Meigooni, Ali S.; Stump, Kurt E.; Thomadsen, Bruce R.; Rivard, Mark J.

    2012-10-01

    In 2011, the American Association of Physicists in Medicine (AAPM) and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) published a report pertaining to uncertainties in brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization's Guide to the Expression of Uncertainty in Measurement and Technical Note 1297 by the National Institute of Standards and Technology are taken as reference standards for uncertainty formalism. Uncertainties involved in measurements or Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is given with uncertainties in each of the brachytherapy dosimetry parameters of the AAPM TG-43 dose-calculation formalism. For low-energy and high-energy brachytherapy sources of low dose-rate and high dose-rate, a combined dosimetric uncertainty AAPM and GEC-ESTRO for their members, and may also be used as guidance to manufacturers and regulatory agencies in developing good manufacturing practices for conventional brachytherapy sources used in routine clinical treatments.

  1. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229 (United States); Cheng, Chih-Yao, E-mail: shic@uthscsa.ed [Radiation Oncology Department, Oklahoma University Health Science Center, Oklahoma, OK 73104 (United States)

    2010-09-21

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V{sub 100} reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as

  2. Dosimetric characterization of the M-15 high-dose-rate Iridium-192 brachytherapy source using the AAPM and ESTRO formalism.

    Science.gov (United States)

    Ho Than, Minh-Tri; Munro Iii, John J; Medich, David C

    2015-05-08

    The Source Production & Equipment Co. (SPEC) model M-15 is a new Iridium-192 brachytherapy source model intended for use as a temporary high-dose-rate (HDR) brachytherapy source for the Nucletron microSelectron Classic afterloading system. The purpose of this study is to characterize this HDR source for clinical application by obtaining a complete set of Monte Carlo calculated dosimetric parameters for the M-15, as recommended by AAPM and ESTRO, for isotopes with average energies greater than 50 keV. This was accomplished by using the MCNP6 Monte Carlo code to simulate the resulting source dosimetry at various points within a pseudoinfinite water phantom. These dosimetric values next were converted into the AAPM and ESTRO dosimetry parameters and the respective statistical uncertainty in each parameter also calculated and presented. The M-15 source was modeled in an MCNP6 Monte Carlo environment using the physical source specifications provided by the manufacturer. Iridium-192 photons were uniformly generated inside the iridium core of the model M-15 with photon and secondary electron transport replicated using photoatomic cross-sectional tables supplied with MCNP6. Simulations were performed for both water and air/vacuum computer models with a total of 4 × 109 sources photon history for each simulation and the in-air photon spectrum filtered to remove low-energy photons belowδ = 10 keV. Dosimetric data, including D·(r,θ), gL(r), F(r,θ), φan(r), and φ-an, and their statistical uncertainty were calculated from the output of an MCNP model consisting of an M-15 source placed at the center of a spherical water phantom of 100 cm diameter. The air kerma strength in free space, SK, and dose rate constant, Λ, also was computed from a MCNP model with M-15 Iridium-192 source, was centered at the origin of an evacuated phantom in which a critical volume containing air at STP was added 100 cm from the source center. The reference dose rate, D·(r0,θ0) ≡ D· (1cm

  3. A comparison of the relative biological effectiveness of low energy electronic brachytherapy sources in breast tissue: a Monte Carlo study

    Science.gov (United States)

    White, Shane A.; Reniers, Brigitte; de Jong, Evelyn E. C.; Rusch, Thomas; Verhaegen, Frank

    2016-01-01

    Electronic brachytherapy sources use low energy photons to treat the tumor bed during or after breast-conserving surgery. The relative biological effectiveness of two electronic brachytherapy sources was explored to determine if spectral differences due to source design influenced radiation quality and if radiation quality decreased with distance in the breast. The RBE was calculated through the number of DNA double strand breaks (RBEDSB) using the Monte Carlo damage simulator (MCDS) in combination with other Monte Carlo electron/photon spectrum calculations. 50kVp photons from the Intrabeam (Carl Zeiss Surgical) and Axxent (Xoft) through 40-mm spherical applicators were simulated to account for applicator and tissue attenuation in a variety of breast tissue compositions. 40kVp Axxent photons were also simulated. Secondary electrons (known to be responsible for most DNA damage) spectra at different distance were inputted into MCDS to calculate the RBEDSB. All RBEDSB used a cobalt-60 reference. RBEDSB data was combined with corresponding average photon spectrum energy for the Axxent and applied to model-based average photon energy distributions to produce an RBEDSB map of an accelerated partial breast irradiation (APBI) patient. Both Axxent and Intrabeam 50kVp spectra were shown to have a comparable RBEDSB of between 1.4 and 1.6 at all distances in spite of progressive beam hardening. The Axxent 40kVp also demonstrated a similar RBEDSB at distances. Most RBEDSB variability was dependent on the tissue type as was seen in rib (RBEDSB  ≈  1.4), gland (≈1.55), adipose (≈1.59), skin (≈1.52) and lung (≈1.50). RBEDSB variability between both sources was within 2%. A correlation was shown between RBEDSB and average photon energy and used to produce an RBEDSB map of a dose distribution in an APBI patient dataset. Radiation quality is very similar between electronic brachytherapy sources studied. No significant reductions in RBEDSB were observed with

  4. A fibre optic scintillator dosemeter for absorbed dose measurements of low-energy X-ray-emitting brachytherapy sources.

    Science.gov (United States)

    Sliski, Alan; Soares, Christopher; Mitch, Michael G

    2006-01-01

    A newly developed dosemeter using a 0.5 mm diameter x 0.5 mm thick cylindrical plastic scintillator coupled to the end of a fibre optic cable is capable of measuring the absorbed dose rate in water around low-activity, low-energy X-ray emitters typically used in prostate brachytherapy. Recent tests of this dosemeter showed that it is possible to measure the dose rate as a function of distance in water from 2 to 30 mm of a (103)Pd source of air-kerma strength 3.4 U (1 U = 1 microGy m(2) h(-1)), or 97 MBq (2.6 mCi) apparent activity, with good signal-to-noise ratio. The signal-to-noise ratio is only dependent on the integration time and background subtraction. The detector volume is enclosed in optically opaque, nearly water-equivalent materials so that there is no polar response other than that due to the shape of the scintillator volume chosen, in this case cylindrical. The absorbed dose rate very close to commercial brachytherapy sources can be mapped in an automated water phantom, providing a 3-D dose distribution with sub-millimeter spatial resolution. The sensitive volume of the detector is 0.5 mm from the end of the optically opaque waterproof housing, enabling measurements at very close distances to sources. The sensitive detector electronics allow the measurement of very low dose rates, as exist at centimeter distances from these sources. The detector is also applicable to mapping dose distributions from more complex source geometries such as eye applicators for treating macular degeneration.

  5. Neutron dosimetry for low dose rate Cf-252 AT sources and adherence to recent clinical dosimetry protocol for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, M.J.; Wierzbicki, J.G.; Van den Heuvel, F. [Wayne State Univ., Detroit, MI (United States). Dept. of Radiation Oncology; Martin, R.C. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.

    1997-12-01

    In 1995, the American Association of Physicists in Medicine Task Group 43 (AAPM TG-43) published a protocol obsoleting all mixed-field radiation dosimetry for Cf-252. Recommendations for a new brachytherapy dosimetry formalism made by this Task Group favor quantification of source strength in terms of air kerma rather than apparent Curies or other radiation units. Additionally, representation of this dosimetry data in terms of radial dose functions, anisotropy functions, geometric factors, and dose rate constants are in an angular and radial (spherical) coordinate system as recommended, rather than the along-away dosimetry data (Cartesian coordinate system) currently available. This paper presents the initial results of calculated neutron dosimetry in a water phantom for a Cf-252 applicator tube (AT) type medical source soon available from Oak Ridge National Laboratory (ORNL).

  6. Evaluation of wall correction factor of INER's air-kerma primary standard chamber and dose variation by source displacement for HDR ¹⁹²Ir brachytherapy.

    Science.gov (United States)

    Lee, J H; Wang, J N; Huang, T T; Su, S H; Chang, B J; Su, C H; Hsu, S M

    2013-01-01

    The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR) ¹⁹²Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan). The Monte Carlo method established in this paper was also employed to respectively simulate wall correction factors of the ¹⁹²Ir air-kerma standard chambers used at the National Institute of Standards and Technology (NIST, USA) and the National Physical Laboratory (NPL, UK) for comparisons and verification. The chamber wall correction calculation results will be incorporated into INER's HDR ¹⁹²Ir primary standard in the future. For the brachytherapy treatment in the esophagus or in the bronchi, the position of the isotope may have displacement in the cavity. Thus the delivered dose would differ from the prescribed dose in the treatment plan. We also tried assessing dose distribution due to the position displacement of HDR ¹⁹²Ir brachytherapy source in a phantom with a central cavity by the Monte Carlo method. The calculated results could offer a clinical reference for the brachytherapy within the human organs with cavity.

  7. Chemonuclear studies for identification for new production routes for the therapeutically useful radionuclides {sup 140}Nd, {sup 192}Ir, {sup 191}Pt, {sup 193m}Pt, und {sup 195m}Pt; Kernchemische Studien zur Entwicklung neuerer Produktionsverfahren fuer die therapierelevanten Radionuklide {sup 140}Nd, {sup 192}Ir, {sup 191}Pt, {sup 193m}Pt, und {sup 195m}Pt

    Energy Technology Data Exchange (ETDEWEB)

    Hilgers, K.

    2005-12-15

    New production routes for the therapeutically useful radionuclides {sup 140}Nd, {sup 192}Ir, {sup 191}Pt, {sup 193m}Pt and {sup 195m}Pt were investigated. Cross section data were measured using the stacked-foil technique and compared with theoretical calculations. A production method for the platinum nuclides was developed. The {sup 141}Pr(p, 2n){sup 140}Nd and {sup nat}Ce({sup 3}He, xn){sup 140}Nd reactions were investigated for production of {sup 140}Nd. Cross section data of nuclear reactions leading to the side products {sup 141}Nd, {sup 139}Nd and {sup 139}Ce could also be achieved. The experimental data were compared with theoretical calculations using the code ALICE-IPPE. A comparison of the calculated thick target yields showed that the {sup 141}Pr(p, 2n){sup 140}Nd reaction gives a higher yield. The {sup 192}Os(p, n){sup 192}Ir reaction was examined in the context of the production of {sup 192}Ir. Cross section data were determined and compared with theoretical calculations using the codes ALICE-IPPE and EMPIRE II. The yield of this reaction was compared with the yield of the reactor production of this nuclide. The reactor production seems to be more suitable because of a higher purity and yield. Cross section data were measured for the {sup 192}Os({alpha}, n){sup 195m}Pt, {sup 192}Os({alpha}, 3n){sup 193m}Pt and {sup 192}Os({sup 3}He, 4n){sup 191}Pt reactions. The activity of {sup 193m}Pt and {sup 195m}Pt was determined by X-ray spectroscopy after a chemical separation procedure. The ALICE-IPPE code was found to be inappropriate to reproduce the experimental values. The calculated yields were compared with the yields of other reactions, especially the reactor production of {sup 195m}Pt. The yield of the {sup 192}Os({alpha}, n){sup 195m}Pt reaction is lower compared to the yield of the reactor production, but offers lower target costs and higher specific activity. A production method for {sup 193m}Pt and {sup 195m}Pt was developed. Batch yields of 0.9 MBq

  8. Investigation of the Effects of Tissue Inhomogeneities on the Dosimetric Parameters of a Cs-137 Brachytherapy Source using the MCNP4C Code

    Directory of Open Access Journals (Sweden)

    Mehdi Zehtabian

    2010-09-01

    Full Text Available Introduction: Brachytherapy is the use of small encapsulated radioactive sources in close vicinity of tumors. Various methods are used to obtain the dose distribution around brachytherapy sources. TG-43 is a dosimetry protocol proposed by the AAPM for determining dose distributions around brachytherapy sources. The goal of this study is to update this protocol for presence of bone and air inhomogenities.  Material and Methods: To update the dose rate constant parameter of the TG-43 formalism, the MCNP4C simulations were performed in phantoms composed of water-bone and water-air combinations. The values of dose at different distances from the source in both homogeneous and inhomogeneous phantoms were estimated in spherical tally cells of 0.5 mm radius using the F6 tally. Results: The percentages of dose reductions in presence of air and bone inhomogenities for the Cs-137 source were found to be 4% and 10%, respectively. Therefore, the updated dose rate constant (Λ will also decrease by the same percentages.   Discussion and Conclusion: It can be easily concluded that such dose variations are more noticeable when using lower energy sources such as Pd-103 or I-125.

  9. A dosimetry method for low dose rate brachytherapy by EGS5 combined with regression to reflect source strength shortage

    Science.gov (United States)

    Tanaka, Kenichi; Tateoka, Kunihiko; Asanuma, Osamu; Kamo, Ken-ichi; Sato, Kaori; Takeda, Hiromitsu; Takagi, Masaru; Hareyama, Masato; Takada, Jun

    2014-01-01

    The post-implantation dosimetry for brachytherapy using Monte Carlo calculation by EGS5 code combined with the source strength regression was investigated with respect to its validity. In this method, the source strength for the EGS5 calculation was adjusted with the regression, so that the calculation would reproduce the dose monitored with the glass rod dosimeters (GRDs) on a water phantom. The experiments were performed, simulating the case where one of two 125I sources of Oncoseed 6711 was lacking strength by 4–48%. As a result, the calculation without regression was in agreement with the GRD measurement within 26–62%. In this case, the shortage in strength of a source was neglected. By the regression, in order to reflect the strength shortage, the agreement was improved up to 17–24%. This agreement was also comparable with accuracy of the dose calculation for single source geometry reported previously. These results suggest the validity of the dosimetry method proposed in this study. PMID:24449715

  10. Comparison and Evaluation of the Effects of Rib and Lung Inhomogeneities on Lung Dose in Breast Brachytherapy using a Treatment Planning System and the MCNPX Code

    Directory of Open Access Journals (Sweden)

    Hossein Salehi Yazdi

    2010-09-01

    Full Text Available Introduction: This study investigates to what extent the computed dose received by lung tissue in a commercially available treatment planning system (TPS for 192Ir high-dose-rate breast brachytherapy is accurate in view of tissue inhomogeneities and presence of ribs. Materials and Methods: A CT scan of the breast was used to construct a patient-equivalent phantom in the clinical treatment planning system. An implant involving 13 plastic catheters and 383 programmed source dwell positions were simulated using the MCNPX code. Results: The results were compared with the corresponding commercial TPS in the form of isodoses and cumulative dose–volume histogram in breast, lung and ribs. The comparison of Monte Carlo results and TPS calculation showed that the isodoses greater than 62% in the breast that were located rather close to the implant or away from the breast curvature surface and lung boundary were in good agreement. TPS calculations, however, overestimated dose in the lung for lower isodose contours and points that were lying near the breast-air boundary and relatively away from the implant. Discussion and Conclusions: Taking into account the ribs and entering the actual data for breast, rib and lung, revealed an average overestimation of dose in lung in the TPS calculation.

  11. Determination of surface dose rate of indigenous (32)P patch brachytherapy source by experimental and Monte Carlo methods.

    Science.gov (United States)

    Kumar, Sudhir; Srinivasan, P; Sharma, S D; Saxena, Sanjay Kumar; Bakshi, A K; Dash, Ashutosh; Babu, D A R; Sharma, D N

    2015-09-01

    Isotope production and Application Division of Bhabha Atomic Research Center developed (32)P patch sources for treatment of superficial tumors. Surface dose rate of a newly developed (32)P patch source of nominal diameter 25 mm was measured experimentally using standard extrapolation ionization chamber and Gafchromic EBT film. Monte Carlo model of the (32)P patch source along with the extrapolation chamber was also developed to estimate the surface dose rates from these sources. The surface dose rates to tissue (cGy/min) measured using extrapolation chamber and radiochromic films are 82.03±4.18 (k=2) and 79.13±2.53 (k=2) respectively. The two values of the surface dose rates measured using the two independent experimental methods are in good agreement to each other within a variation of 3.5%. The surface dose rate to tissue (cGy/min) estimated using the MCNP Monte Carlo code works out to be 77.78±1.16 (k=2). The maximum deviation between the surface dose rates to tissue obtained by Monte Carlo and the extrapolation chamber method is 5.2% whereas the difference between the surface dose rates obtained by radiochromic film measurement and the Monte Carlo simulation is 1.7%. The three values of the surface dose rates of the (32)P patch source obtained by three independent methods are in good agreement to one another within the uncertainties associated with their measurements and calculation. This work has demonstrated that MCNP based electron transport simulations are accurate enough for determining the dosimetry parameters of the indigenously developed (32)P patch sources for contact brachytherapy applications.

  12. CT-guided high-dose-rate brachytherapy of unresectable hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, Federico; Schreiber, Nadja; Schnapauff, Dirk; Denecke, Timm; Hamm, Bernd; Gebauer, Bernhard [ChariteUniversitaetsmedizin Berlin, Department of Diagnostic and Interventional Radiology, Berlin (Germany); Wust, Peter [ChariteUniversitaetsmedizin Berlin, Department of Radiation Oncology, Berlin (Germany); Schott, Eckart [Universitaetsmedizin Berlin, Department of Gastroenterology, Berlin (Germany)

    2015-05-01

    The purpose of the present study was to evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) in patients with unresectable hepatocellular carcinoma (HCC). Over a 6-year period, 98 patients with 212 unresectable HCC underwent CT-HDRBT applying a {sup 192}Ir source at our institution. Magnetic resonance imaging (MRI) follow-up was performed 6 weeks after the intervention and then every 3 months. The primary endpoint was local tumor control (LTC); secondary endpoints included progression-free survival (PFS) and overall survival (OS). Patients were available for MRI evaluation for a mean follow-up of 23.1 months (range 4-64 months; median 20 months). Mean tumor diameter was 5 cm (range 1.8-12 cm). Eighteen of 212 (8.5 %) tumors showed local progression after a mean LTC of 21.1 months. In all, 67 patients (68.4 %) experienced distant tumor progression. The mean PFS was 15.2 months. Forty-six patients died during the follow-up period. Median OS was 29.2 months. Actuarial 1-, 2-, and 3-year OS rates were 80, 62, and 46 %, respectively. CT-HDRBT is an effective therapy to attain local tumor control in patients with unresectable HCC. Prospective randomized studies comparing CT-HDRBT with the standard treatments like Radiofrequency ablation (RFA) and chemoembolization (TACE) are mandatory. (orig.) [German] Zweck der vorliegenden Arbeit war die Analyse der klinischen Effektivitaet der CT-gesteuerten Hochdosis-Brachytherapie (CT-HDRBT) bei Patienten mit inoperablem hepatozellulaeren Karzinom (HCC). Ueber einen Zeitraum von 6 Jahren, wurden an unserer Klinik 98 Patienten mit 212 inoperablen HCC mittels CT-HDRBT mit {sup 192}Ir behandelt. MRT-Verlaufskontrollen erfolgten 6 Wochen nach der Intervention und dann alle 3 Monate. Primaerer Endpunkt der Studie war die lokale Tumorkontrolle (LTC); sekundaere Endpunkte waren das progressionsfreie Ueberleben (PFS) und Gesamtueberleben (OS). Die mittlere Nachbeobachtungszeit betrug 23,1 Monate (Spanne 4

  13. SU-E-T-171: Characterization of the New Xoft Axxent Electronic Brachytherapy Source Using PRESAGE Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, A; Followill, D; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States); Adamovics, J [John Adamovics, Skillman, NJ (United States)

    2015-06-15

    Purpose: To characterize the Xoft Axxent electronic brachytherapy source using PRESAGE™ dosimeters to obtain independent confirmation of TG-43U1 dosimetry values from previous studies and ascertain its reproducibility in HDR brachytherapy. Methods: PRESAGE™ dosimeters are solid, polyurethane-based dosimeters doped with radiochromic leucodyes that produce a linear optical-density response when exposed to radiation. Eight 1-kg dosimeters were scanned prior to irradiation on an optical-CT scanner to eliminate background signal and any optical imperfections from each dosimeter. To quantify potential imaging artifacts due to oversaturated responses in the immediate range of the source, half of the eight dosimeters were cast with a smaller channel diameter of 5.4 mm, and the other half were cast with a larger channel diameter of 15mm. During irradiation, the catheters were placed in the center of each channel. Catheters fit the 5.4mm diameters channels whereas polyurethane plugs were inserted into the larger channels to create a sturdy, immobile catheter which allowed uniform dose distributions. Two dosimeters of each 5.4mm and 15mm were irradiated at either 1517.3 cGy or 2017.5 cGy. Post-irradiation scans were performed within 48 hours of irradiation. A 3D reconstruction based on subtraction of these two images and the relative dose measurements were made using in-house software. Results: Comparing measured radial dose rates with previous results revealed smaller percent errors when PRESAGE™ irradiations were at lower maximum dose. The dosimeters showed small deviations in radial dose function, g{sub p} (r), from previous studies. Among the dosimeters irradiated at 1517.3 cGy, the g{sub p}(r) compared to previous studies fluctuated from 0.0043 to 0.3922. This suggests small fluctuations can drastically change radial dose calculations. Conclusion: The subtraction of pre-irradiation and post-irradiation scans of PRESAGE™ dosimeters using an optical-CT scanner

  14. A Customized Finger Brachytherapy Carrier

    OpenAIRE

    Wadhwa, Supneet Singh; Duggal, Nidhi

    2013-01-01

    In recent years, radiation therapy has been used with increasing frequency in the management of neoplasms of the head and neck region. Brachytherapy is a method of radiation treatment in which sealed radioactive sources are used to deliver the dose a short distance by interstitial (direct insertion into tissue), intracavitary (placement within a cavity) or surface application (molds). Mold brachytherapy is radiation delivered via a custom-fabricated carriers, designed to provide a more consta...

  15. Quantification of iodine in porous hydroxyapatite matrices for application as radioactive sources in brachytherapy

    Directory of Open Access Journals (Sweden)

    Kássio André Lacerda

    2007-07-01

    Full Text Available In this study, non-radioactive iodine was incorporated in two types of biodegradable hydroxyapatite-based porous matrices (HA and HACL through impregnation process from sodium iodine aqueous solutions with varying concentrations (0.5 and 1.0 mol/L . The results revealed that both systems presented a high capacity of incorporating iodine into their matrices. The quantity of incorporated iodine was measured through Neutron Activation Analysis (NAA. The porous ceramic matrices based on hydroxyapatite demonstrated a great potential for uses in low dose rate (LDR brachytherapy.Materiais cerâmicos porosos à base de compostos de fosfatos de cálcio (CFC vêm sendo estudados e desenvolvidos para várias aplicações biomédicas tais como implantes, sistemas para liberação de drogas e fontes radioativas para braquiterapia. Dois tipos de matrizes porosas biodegradáveis de hidroxiapatita (HA e HACL foram avaliadas em termos da capacidade de incorporação de iodo em suas estruturas. Resultados revelaram que as matrizes porosas a base de hidroxiapatita apresentaram alta capacidade de incorporar iodo em sua estrutura. A quantidade de iodo foi mensurada através da técnica de Análise por Ativação Nêutronica (AAN. As matrizes cerâmicas porosas à base de hidroxiapatita demostraram ter grande potencial para aplicação em braquiterapia de baixa taxa de dose (LDR - Low Dose Rate.

  16. Intraoperative HDR Brachytherapy: Present and Future

    NARCIS (Netherlands)

    I.-K.K. Kolkman-Deurloo (Inger-Karina)

    2007-01-01

    textabstractRadiotherapy is one of the most effective modalities in cancer treatment, and can be applied either by external beam radiotherapy or by brachytherapy. Brachytherapy is a treatment modality in which tumors are irradiated by positioning radioactive sources very close to or in the tumor vol

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J. L., E-mail: jlreed2@wisc.edu; Micka, J. A.; Culberson, W. S.; DeWerd, L. A. [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 (United States); Rasmussen, B. E. [Department of Radiation Oncology, UP Health System Marquette, 580 West College Avenue, Marquette, Michigan 49855 (United States); Davis, S. D. [Department of Medical Physics, McGill University Health Centre, Montreal General Hospital (L5-112), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada)

    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.

  18. HDR Brachytherapy Dose Distribution is Influenced by the Metal Material of the Applicator.

    Science.gov (United States)

    Wu, Chin-Hui; Liao, Yi-Jen; Shiau, An-Cheng; Lin, Hsin-Yu; Hsueh Liu, Yen-Wan; Hsu, Shih-Ming

    2015-12-11

    Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicator. The primary purpose of this study was to evaluate the HDR (192)Ir dose distribution in cervical cancer patients when performing brachytherapy using a metal-containing applicator. Thermoluminescent dosimeter (TLD) measurements and Monte Carlo N-Particle eXtended (MCNPX) code were used to explore the doses to the rectum and bladder when using a Henschke applicator containing metal during brachytherapy. When the applicator was assumed to be present, the absolute dose difference between the TLD measurement and MCNPX simulation values was within approximately 5%. A comparison of the MCNPX simulation and TPS calculation values revealed that the TPS overestimated the International Commission of Radiation Units and Measurement (ICRU) rectum and bladder reference doses by 57.78% and 49.59%, respectively. We therefore suggest that the TPS should be modified to account for the shielding effects of the applicator to ensure the accuracy of the delivered doses.

  19. Well-Type Ionization Chamber for 192Ir Source Calibration%用于校准192Ir医用源的阱型电离室

    Institute of Scientific and Technical Information of China (English)

    郭文; 罗素明; 魏可新; 李景云

    2007-01-01

    研制了一种用于校准医用192Ir源的阱型电离室.该电离室的灵敏体积约为271 cm3,在极化电压为300 V时,电离室的离子收集效率约为99.96%,总位置灵敏度变化小于0.3%.该阱型电离室对192Ir的响应因子为0.230 nA/GBq,其相对合成不确定度为1.5%,与IAEA校准过的阱型电离室比对,在不确定度范围内一致.

  20. Specification of absorbed dose to water using model-based dose calculation algorithms for treatment planning in brachytherapy.

    Science.gov (United States)

    Tedgren, Åsa Carlsson; Carlsson, Gudrun Alm

    2013-04-21

    Model-based dose calculation algorithms (MBDCAs), recently introduced in treatment planning systems (TPS) for brachytherapy, calculate tissue absorbed doses. In the TPS framework, doses have hereto been reported as dose to water and water may still be preferred as a dose specification medium. Dose to tissue medium Dmed then needs to be converted into dose to water in tissue Dw,med. Methods to calculate absorbed dose to differently sized water compartments/cavities inside tissue, infinitesimal (used for definition of absorbed dose), small, large or intermediate, are reviewed. Burlin theory is applied to estimate photon energies at which cavity sizes in the range 1 nm-10 mm can be considered small or large. Photon and electron energy spectra are calculated at 1 cm distance from the central axis in cylindrical phantoms of bone, muscle and adipose tissue for 20, 50, 300 keV photons and photons from (125)I, (169)Yb and (192)Ir sources; ratios of mass-collision-stopping powers and mass energy absorption coefficients are calculated as applicable to convert Dmed into Dw,med for small and large cavities. Results show that 1-10 nm sized cavities are small at all investigated photon energies; 100 µm cavities are large only at photon energies <20 keV. A choice of an appropriate conversion coefficient Dw, med/Dmed is discussed in terms of the cavity size in relation to the size of important cellular targets. Free radicals from DNA bound water of nanometre dimensions contribute to DNA damage and cell killing and may be the most important water compartment in cells implying use of ratios of mass-collision-stopping powers for converting Dmed into Dw,med.

  1. Impact of Heterogeneity-Based Dose Calculation Using a Deterministic Grid-Based Boltzmann Equation Solver for Intracavitary Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mikell, Justin K. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas (United States); Klopp, Ann H. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gonzalez, Graciela M.N. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kisling, Kelly D. [Department of Radiation Physics-Patient Care, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas (United States); Price, Michael J. [Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, Louisiana, and Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana (United States); Berner, Paula A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Eifel, Patricia J. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mourtada, Firas, E-mail: fmourtad@christianacare.org [Department of Radiation Physics-Patient Care, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Experimental Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Helen F. Graham Cancer Center, Newark, Delaware (United States)

    2012-07-01

    Purpose: To investigate the dosimetric impact of the heterogeneity dose calculation Acuros (Transpire Inc., Gig Harbor, WA), a grid-based Boltzmann equation solver (GBBS), for brachytherapy in a cohort of cervical cancer patients. Methods and Materials: The impact of heterogeneities was retrospectively assessed in treatment plans for 26 patients who had previously received {sup 192}Ir intracavitary brachytherapy for cervical cancer with computed tomography (CT)/magnetic resonance-compatible tandems and unshielded colpostats. The GBBS models sources, patient boundaries, applicators, and tissue heterogeneities. Multiple GBBS calculations were performed with and without solid model applicator, with and without overriding the patient contour to 1 g/cm{sup 3} muscle, and with and without overriding contrast materials to muscle or 2.25 g/cm{sup 3} bone. Impact of source and boundary modeling, applicator, tissue heterogeneities, and sensitivity of CT-to-material mapping of contrast were derived from the multiple calculations. American Association of Physicists in Medicine Task Group 43 (TG-43) guidelines and the GBBS were compared for the following clinical dosimetric parameters: Manchester points A and B, International Commission on Radiation Units and Measurements (ICRU) report 38 rectal and bladder points, three and nine o'clock, and {sub D2cm3} to the bladder, rectum, and sigmoid. Results: Points A and B, D{sub 2} cm{sup 3} bladder, ICRU bladder, and three and nine o'clock were within 5% of TG-43 for all GBBS calculations. The source and boundary and applicator account for most of the differences between the GBBS and TG-43 guidelines. The D{sub 2cm3} rectum (n = 3), D{sub 2cm3} sigmoid (n = 1), and ICRU rectum (n = 6) had differences of >5% from TG-43 for the worst case incorrect mapping of contrast to bone. Clinical dosimetric parameters were within 5% of TG-43 when rectal and balloon contrast were mapped to bone and radiopaque packing was not overridden

  2. Absorbed dose distribution of brachytherapy sources through Fricke xylenol gel dosimetry; Distribuicao da dose absorvida de fontes braquiterapicas atraves da dosimetria bidimensional Fricke xylenol gel

    Energy Technology Data Exchange (ETDEWEB)

    Mangueira, T.F.; Almeida, A. de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Departamento de Fisica e Matematica; Costa, J.J.L., E-mail: lucas@ifg.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Goias (IFG), Inhumas, GO (Brazil); Caldas, Linda V.E.; Oliveira, L.N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Moreira, M.V. [Instituto Ribeiraopretano de Combate ao Cancer (IRPCC), Ribeirao Preto, SP (Brazil)

    2013-07-15

    brachytherapy techniques used throughout the world is derived, or has as a principle the method Paterson-Parker (PP), which ensures the homogeneity of 10% of the treatment plan (target volume), the distance 'h' from the plane formed the source distribution brachytherapy irradiation. Thus, the method ensures that the maximum dose does not exceed 10% of the dose set to satisfy the criteria for uniformity. In this study, we evaluated the method PP measures in dose distribution, having as the Fricke Xylenol Gel dosimeter (FXG), which was irradiated with an orderly distribution of sources of treatment. The distribution was made with eight sources of {sup 137}Cs, distributed in the rules of the PP method, with h = 5.75 mm. The phantom was a distribution of 5 x 5 cm{sup 2} standard spectrophotometer cuvettes (each 1.25 x 1.25 x 3.5 cm{sup 3} optical path length) FXG filled with a total volume of 5 x 5 x 3.5 cm{sup 3}. The phantom was irradiated in a time of 3.3 h resulting in an absorbed dose of 10 Gy in the treatment plan. Then, the FXG was read in a monospectrophotometer and their results were processed in a routine MATLAB Registered-Sign thereby obtaining the dose distribution. The homogeneity was calculated at 7.8% in the treatment plan, which is in accordance with the protocols of IAEA-TECDOC-602. (author)

  3. Characteristics and locations of sources

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, J.; Poellaenen, R.; Toivonen, H. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-12-31

    Ten artificial radiation sources were placed in the terrain in order to test the capability of airborne measuring teams to detect them. One of the sources was a line source, others were point sources (three of them collimated). The radionuclides used in the sources were {sup 60}Co, {sup 137}Cs, {sup 99m}Tc and {sup 192}Ir. The source activities ranged from about 26 MBq (one of the cobalt sources) to 0.56 TBq (iridium). (au).

  4. Interstitial prostate brachytherapy. LDR-PDR-HDR

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, Gyoergy [Luebeck Univ. (Germany). Interdiscipliary Brachytherapy Unit; Hoskin, Peter (ed.) [London Univ. College (United Kingdom). Mount Vernon Cancer Centre

    2013-07-01

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  5. Calculating Error Percentage in Using Water Phantom Instead of Soft Tissue Concerning 103Pd Brachytherapy Source Distribution via Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    OL Ahmadi

    2015-12-01

    Full Text Available Introduction: 103Pd is a low energy source, which is used in brachytherapy. According to the standards of American Association of Physicists in Medicine, dosimetric parameters determination of brachytherapy sources before the clinical application was considered significantly important. Therfore, the present study aimed to compare the dosimetric parameters of the target source using the water phantom and soft tissue. Methods: According to the TG-43U1 protocol, the dosimetric parameters were compared around the 103Pd source in regard with water phantom with the density of 0.998 gr/cm3 and the soft tissue with the density of 1.04 gr/cm3 on the longitudinal and transverse axes using the MCNP4C code and the relative differences were compared between the both conditions. Results: The simulation results indicated that the dosimetric parameters depended on the radial dose function and the anisotropy function in the application of the water phantom instead of soft tissue up to a distance of 1.5 cm,  between which a good consistency was observed. With increasing the distance, the difference increased, so as within 6 cm from the source, this difference increased to 4%. Conclusions: The results of  the soft tissue phantom compared with those of the water phantom indicated 4% relative difference at a distance of 6 cm from the source. Therefore, the results of the water phantom with a maximum error of 4% can be used in practical applications instead of soft tissue. Moreover, the amount of differences obtained in each distance regarding using the soft tissue phantom could be corrected.

  6. Brachytherapy for the prevention of neointimal hyperplasia in the canine inferior vena cava after stent placement

    Energy Technology Data Exchange (ETDEWEB)

    Isota, Masayuki; Kaminou, Toshio; Sakai, Yukimasa; Nakamura, Kenji; Yamada, Ryusaku [Osaka City Univ. (Japan). Medical School

    2002-06-01

    The aim of this study was to evaluate the efficacy of brachytherapy for preventing neointimal hyperplasia in the inferior vena cava (IVC) after stent placement. Sixteen beagles underwent Z-stent placement in the IVC and the aorta. For 8 of 16 beagles, irradiation (15 Gy) was delivered endoluminally to the stented segments of each vessel immediately after stent placement using the {sup 192}Ir. All animals were sacrificed after 6 weeks for morphometric and histopathologic examination. Morphometrically, neointimal thickness in the IVC of the radiation group was significantly decreased compared with the control group as well as that in the aorta (p<0.05). Histopathologic findings showed the neointima in the IVC of the control group contained markedly organization of thrombus and neovascularization though that in the IVC of the radiation group consisted mainly of smooth muscle cells without organization of thrombus and neovascularization. From these data intravenous irradiation may prevent clinical restenosis after stent placement. (author)

  7. Brachytherapy applications and techniques

    CERN Document Server

    Devlin, Phillip M

    2015-01-01

    Written by the foremost experts in the field, this volume is a comprehensive text and practical reference on contemporary brachytherapy. The book provides detailed, site-specific information on applications and techniques of brachytherapy in the head and neck, central nervous system, breast, thorax, gastrointestinal tract, and genitourinary tract, as well as on gynecologic brachytherapy, low dose rate and high dose rate sarcoma brachytherapy, vascular brachytherapy, and pediatric applications. The book thoroughly describes and compares the four major techniques used in brachytherapy-intraca

  8. A novel approach for the adsorption of iodine-125 on silver wire as matrix for brachytherapy source for the treatment of eye and prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, C.; Majali, M.A. E-mail: mythili@magnum.barc.ernet.in; Balakrishnan, S.A

    2002-09-01

    The adsorption of iodine-125 on silver wire bits coated with palladium to be sealed in titanium capsules as brachytherapy sources was studied. A method was optimized to obtain quantitative adsorption of {sup 125}I on the palladium treated silver wires. A comparative evaluation of palladium coated and uncoated (bare) silver wires on the adsorption of {sup 125}I was made. While, the adsorption of bare silver wires showed low, inconsistent uptake ({approx}60%) of {sup 125}I with high leachability ({approx}4%), the Pd coated silver wires showed quantitative and consistent uptake of {sup 125}I ({approx}90%) and exhibited low leachability (0.01%). {sup 125}I adsorbed on Pd coated silver wires could be used as a matrix for the preparation of interstitial sources in eye and prostate cancer therapy.

  9. Clinical outcome of high-dose-rate interstitial brachytherapy in patients with oral cavity cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Uk; Cho, Kwan Ho; Moon, Sung Ho; Choi, Sung Weon; Park, Joo Yong; Yun, Tak; Lee, Sang Hyun; Lim, Young Kyung; Jeong, Chi Young [National Cancer Center, Goyang (Korea, Republic of)

    2014-12-15

    To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.

  10. A robotic device for MRI-guided prostate brachytherapy

    NARCIS (Netherlands)

    Lagerburg, V.

    2008-01-01

    One of the treatment options for prostate cancer is brachytherapy with iodine-125 sources. In prostate brachytherapy a high radiation dose is delivered to the prostate with a steep dose fall off to critical surrounding organs. The implantation of the iodine sources is currently performed under ultra

  11. Combined transperineal radiofrequency (RF) interstitial hyperthermia and brachytherapy for localized prostate cancer (PC)

    Energy Technology Data Exchange (ETDEWEB)

    Urakami, Shinji; Gonda, Nobuko; Kikuno, Nobuyuki [Shimane Medical Univ., Izumo (Japan)] (and others)

    2001-05-01

    Hyperthermia has been used effectively as a radiation sensitizer. Interstitial hyperthermoradiotherapy has been therefore utilized as a minimal invasive therapy in attempts to improve local tumor control for various cancers, but not for urological cancer. The purpose of this study was to investigate the safety and feasibility of transperineal hyperthermoradiotherapy for localized PC. Based on our basic study of hyperthermoradiotherapy, we devised the procedure of combined transperineal RF interstitial hyperthermia and brachytherapy for localized prostate cancer. Two patients with localized PC underwent transperineal RF interstitial hyperthermia combined with brachytherapy operation the 192-Ir remote after-loading system (RALS). Under transrectal ultrasound guidance, a total number of 12-18 stainless steel needles for 192-Ir RALS were implanted into the prostatic gland and seminal vesicles (SV) in an optimized pattern. Eight of the needles were used as electrodes for hyperthermia, and were electrically insultated using the vinyl catheter along the length of the subdermal fatty tissue to protect from overheating. Three other needles were utilized for continuous temperature mapping in the prostate. Rectal temperature was also monitored. Total radiation doses of 70 Gy to the prostate and SV were planned as a combination of brachytherapy (24 Gy/4 fraction) and external irradiation using a four-field box technique (46 Gy/23 fraction). Hyperthermic treatment (goal of 42 to 43 deg C for 60 minutes) was performed twice following the 1st and 4th brachytherapy at an interval of more than 48 hours for the recovery of cancer cells from thermotolerance. Both patients reached the treatment goal of all intraprostatic temperatures >43.0 deg C, which was considered favorable for hyperthermia, and the rectal temperatures of both patients remained <38 deg C during hyperthermia. In serial PSA measurements of both patients, serum PSA was less than 1.0 ng/ml within 3 months and has since

  12. Influence of radioactive sources discretization in the Monte Carlo computational simulations of brachytherapy procedures: a case study on the procedures for treatment of prostate cancer; Influencia da discretizacao das fontes radioativas nas simulacoes computacionais Monte Carlo de procedimentos de braquiterapia: um estudo de caso sobre os procedimentos para tratamento do cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Antonio Konrado de Santana; Vieira, Jose Wilson [Instituto Federal de Educacao, Ciencia e Tecnologia (IFPE), Recife, PE (Brazil); Costa, Kleber Souza Silva [Faculdade Integrada de Pernambuco (FACIPE), Recife, PE (Brazil); Lima, Fernando Roberto de Andrade, E-mail: falima@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    Radiotherapy computational simulation procedures using Monte Carlo (MC) methods have shown to be increasingly important to the improvement of cancer fighting strategies. One of the biases in this practice is the discretization of the radioactive source in brachytherapy simulations, which often do not match with a real situation. This study had the aim to identify and to measure the influence of radioactive sources discretization in brachytherapy MC simulations when compared to those that do not present discretization, using prostate brachytherapy with Iodine-125 radionuclide as model. Simulations were carried out with 108 events with both types of sources to compare them using EGSnrc code associated to MASH phantom in orthostatic and supine positions with some anatomic adaptations. Significant alterations were found, especially regarding bladder, rectum and the prostate itself. It can be concluded that there is a need to discretized sources in brachytherapy simulations to ensure its representativeness. (author)

  13. The role of brachytherapy in radiation and isotopes centre of Khartoum (RICK)

    CERN Document Server

    Ali, A M

    2000-01-01

    As there are many efforts devoted in order to manage the cancer, here the researcher handle one of these efforts that play a major part in treating the cancer internationally, it is a brachytherapy system. Brachytherapy was carried out mostly with radium sources, but recently some artificial sources are incorporated in this mode of treatment such as Cs-137, Ir-192, Au-198, P-32, Sr-90 and I-125. The research cover history of brachytherapy and radioactive sources used in, techniques of implementation, radiation protection and methods of brachytherapy dose calculation, as well as brachytherapy in radiation and isotopes centre in Khartoum.

  14. Comprehensive brachytherapy physical and clinical aspects

    CERN Document Server

    Baltas, Dimos; Meigooni, Ali S; Hoskin, Peter J

    2013-01-01

    Modern brachytherapy is one of the most important oncological treatment modalities requiring an integrated approach that utilizes new technologies, advanced clinical imaging facilities, and a thorough understanding of the radiobiological effects on different tissues, the principles of physics, dosimetry techniques and protocols, and clinical expertise. A complete overview of the field, Comprehensive Brachytherapy: Physical and Clinical Aspects is a landmark publication, presenting a detailed account of the underlying physics, design, and implementation of the techniques, along with practical guidance for practitioners. Bridging the gap between research and application, this single source brings together the technological basis, radiation dosimetry, quality assurance, and fundamentals of brachytherapy. In addition, it presents discussion of the most recent clinical practice in brachytherapy including prostate, gynecology, breast, and other clinical treatment sites. Along with exploring new clinical protocols, ...

  15. SU-F-BRA-09: New Efficient Method for Xoft Axxent Electronic Brachytherapy Source Calibration by Pre-Characterizing Surface Applicators

    Energy Technology Data Exchange (ETDEWEB)

    Pai, S [iCAD Inc., Los Gatos, CA (United States)

    2015-06-15

    Purpose: The objective is to improve the efficiency and efficacy of Xoft™ Axxent™ electronic brachytherapy (EBT) calibration of the source & surface applicator using AAPM TG-61 formalism. Methods: Current method of Xoft EBT source calibration involves determination of absolute dose rate of the source in each of the four conical surface applicators using in-air chamber measurements & TG61 formalism. We propose a simplified TG-61 calibration methodology involving initial characterization of surface cone applicators. This is accomplished by calibrating dose rates for all 4 surface applicator sets (for 10 sources) which establishes the “applicator output ratios” with respect to the selected reference applicator (20 mm applicator). After the initial time, Xoft™ Axxent™ source TG61 Calibration is carried out only in the reference applicator. Using the established applicator output ratios, dose rates for other applicators will be calculated. Results: 200 sources & 8 surface applicator sets were calibrated cumulatively using a Standard Imaging A20 ion-chamber in accordance with manufacturer-recommended protocols. Dose rates of 10, 20, 35 & 50mm applicators were normalized to the reference (20mm) applicator. The data in Figure 1 indicates that the normalized dose rate variation for each applicator for all 200 sources is better than ±3%. The average output ratios are 1.11, 1.02 and 0.49 for the 10 mm,35 mm and 50 mm applicators, respectively, which are in good agreement with the manufacturer’s published output ratios of 1.13, 1.02 and 0.49. Conclusion: Our measurements successfully demonstrate the accuracy of a new calibration method using a single surface applicator for Xoft EBT sources and deriving the dose rates of other applicators. The accuracy of the calibration is improved as this method minimizes the source position variation inside the applicator during individual source calibrations. The new method significantly reduces the calibration time to less

  16. A revised dosimetric characterization of the model S700 electronic brachytherapy source containing an anode-centering plastic insert and other components not included in the 2006 model

    Energy Technology Data Exchange (ETDEWEB)

    Hiatt, Jessica R. [Department of Radiation Oncology, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903 (United States); Davis, Stephen D. [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec H3G 1A4 (Canada); Rivard, Mark J., E-mail: mark.j.rivard@gmail.com [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2015-06-15

    Purpose: The model S700 Axxent electronic brachytherapy source by Xoft, Inc., was characterized by Rivard et al. in 2006. Since then, the source design was modified to include a new insert at the source tip. Current study objectives were to establish an accurate source model for simulation purposes, dosimetrically characterize the new source and obtain its TG-43 brachytherapy dosimetry parameters, and determine dose differences between the original simulation model and the current model S700 source design. Methods: Design information from measurements of dissected model S700 sources and from vendor-supplied CAD drawings was used to aid establishment of an updated Monte Carlo source model, which included the complex-shaped plastic source-centering insert intended to promote water flow for cooling the source anode. These data were used to create a model for subsequent radiation transport simulations in a water phantom. Compared to the 2006 simulation geometry, the influence of volume averaging close to the source was substantially reduced. A track-length estimator was used to evaluate collision kerma as a function of radial distance and polar angle for determination of TG-43 dosimetry parameters. Results for the 50 kV source were determined every 0.1 cm from 0.3 to 15 cm and every 1° from 0° to 180°. Photon spectra in water with 0.1 keV resolution were also obtained from 0.5 to 15 cm and polar angles from 0° to 165°. Simulations were run for 10{sup 10} histories, resulting in statistical uncertainties on the transverse plane of 0.04% at r = 1 cm and 0.06% at r = 5 cm. Results: The dose-rate distribution ratio for the model S700 source as compared to the 2006 model exceeded unity by more than 5% for roughly one quarter of the solid angle surrounding the source, i.e., θ ≥ 120°. The radial dose function diminished in a similar manner as for an {sup 125}I seed, with values of 1.434, 0.636, 0.283, and 0.0975 at 0.5, 2, 5, and 10 cm, respectively. The radial dose

  17. Synthesis and characterization of hydroxyapatite porous matrixes for application as radiation sources in brachytherapy; Sintese e caracterizacao de matrizes porosas de hidroxiapatita para aplicacao como fontes radioativas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Kassio Andre; Lameiras, Fernando Soares; Silva, Viviane Viana [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: kassiolacerda@yahoo.com.br

    2006-04-15

    Porous ceramic materials based on calcium phosphate compounds (CPC) have been studied aiming at different biomedical applications such as implants, drug delivery systems and radioactive sources for brachytherapy. Two kinds of hydroxyapatite (HAp) powders and their ceramic bodies were characterized by a combination of different techniques (X-rays diffraction and fluorescence, infrared spectrophotometry, BET method, thermal analysis, and scanning electron microscopy) to evaluate their physico-chemical and microstructural characteristics in terms of chemical composition, segregated phases, microstructure, porosity, and chemical and thermal stability. The results revealed that these systems presented potential for use as porous biodegradable radioactive sources able to be loaded with a wide range of radionuclides for cancer treatment by the brachytherapy technique. (author)

  18. In vivo dosimetry HDR brachytherapy prostate with source CO-60: Results of measures in a point urethra; Dosimetria in vivo en braquiterapia HDR de prostate con fuente de CO-60: Resultados de medidas en un punto de uretra

    Energy Technology Data Exchange (ETDEWEB)

    Latorre, D.; Fernandez, J.; Rivero, G.; Crelgo, D.; Gonzalez, J. M.; Sanchez, P.; Villace, A.; Sanchez, E.; Arroyo, M. A.; Garcia, E.; Trabanco, E.

    2015-07-01

    In this study we present and analyze the results of the in vivo dosimetry made a point of urethra with a group of 30 patients treated with brachytherapy prostate high rate with Co-60 source. Taking into account the uncertainties, the results and integration, globally evaluate this system DIV. This DIV system, due to its ease of calibration and use, and provides a relatively simple integration way to avoid serious errors in administering treatment. (Author)

  19. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems

    Energy Technology Data Exchange (ETDEWEB)

    Chang Liyun; Ho, Sheng-Yow; Chui, Chen-Shou; Du, Yi-Chun; Chen Tainsong [Institute of Biochemical Engineering, National Cheng-Kung University, Tainan 701, Taiwan (China) and Department of Radiation Oncology, Sinlau Christian Hospital, Tainan 701, Taiwan (China); Department of Radiation Oncology, Sinlau Christian Hospital, Tainan 701, Taiwan (China); Department of Medical Physics, Sun Yat-Sen Cancer Center, Taipei 112, Taiwan (China); Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 701, Taiwan (China)

    2009-09-15

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: ''The institution should verify the full process of any reconstruction technique employed clinically.'' Error modeling was also performed to analyze seed-position errors. The ''isocentric beam checker'' device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roueet al. [''The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy,'' Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 deg. reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to

  20. A BrachyPhantom for verification of dose calculation of HDR brachytherapy planning system

    Energy Technology Data Exchange (ETDEWEB)

    Austerlitz, C. [Clinica Diana Campos, Recife, PE 52020-030 (Brazil); Campos, C. A. T. [Pontifícia Universidade Católica do Rio de Janeiro, RJ 22451-900 (Brazil)

    2013-11-15

    Purpose: To develop a calibration phantom for {sup 192}Ir high dose rate (HDR) brachytherapy units that renders possible the direct measurement of absorbed dose to water and verification of treatment planning system.Methods: A phantom, herein designated BrachyPhantom, consists of a Solid Water™ 8-cm high cylinder with a diameter of 14 cm cavity in its axis that allows the positioning of an A1SL ionization chamber with its reference measuring point at the midheight of the cylinder's axis. Inside the BrachyPhantom, at a 3-cm radial distance from the chamber's reference measuring point, there is a circular channel connected to a cylindrical-guide cavity that allows the insertion of a 6-French flexible plastic catheter from the BrachyPhantom surface. The PENELOPE Monte Carlo code was used to calculate a factor, P{sub sw}{sup lw}, to correct the reading of the ionization chamber to a full scatter condition in liquid water. The verification of dose calculation of a HDR brachytherapy treatment planning system was performed by inserting a catheter with a dummy source in the phantom channel and scanning it with a CT. The CT scan was then transferred to the HDR computer program in which a multiple treatment plan was programmed to deliver a total dose of 150 cGy to the ionization chamber. The instrument reading was then converted to absorbed dose to water using the N{sub gas} formalism and the P{sub sw}{sup lw} factor. Likewise, the absorbed dose to water was calculated using the source strength, S{sub k}, values provided by 15 institutions visited in this work.Results: A value of 1.020 (0.09%, k= 2) was found for P{sub sw}{sup lw}. The expanded uncertainty in the absorbed dose assessed with the BrachyPhantom was found to be 2.12% (k= 1). To an associated S{sub k} of 27.8 cGy m{sup 2} h{sup −1}, the total irradiation time to deliver 150 cGy to the ionization chamber point of reference was 161.0 s. The deviation between the absorbed doses to water assessed with

  1. Study of the Dose Distribution of 192Ir、 125I Seed in Different Tissue in Brachytherapy%不同人体组织中192Ir、125I粒子源的剂量分布研究

    Institute of Scientific and Technical Information of China (English)

    汤晓斌; 陈飞达; 谢芹; 刘云鹏; 耿长冉; 陈达

    2011-01-01

    目的:计算分析近距离放疗中不同粒子源、不同插植部位的剂量分布.方法:利用蒙特卡罗粒子输运工具包Geant4,计算近距离放疗中192Ir、125I两种粒子源在不同介质中剂量分布的差异,并根据美国医学物理学会43号工作组报告推荐的近距离放疗剂量计算公式(AAPM TG-43)对其重要参数进行修正.结果:计算得到192Ir源、125I源在三种不同组织等效材料中的径向剂量函数、各项异性函数.结论:(1)径向剂量函数决定于介质对光子的线能量衰减系数.衰减系数越大,径向剂量函数下降越快,反之越平缓;125I粒子源的径向剂量函数随距源距离增大而衰减的趋势远大于192Ir粒子源.(2)随着距源距离增大,骨、水等效组织中各向异性函数曲线趋于平坦,肺等效组织则没有变化.%Objective: The dose distribution is one of the most essential questions in brachytherapy. The dose varies largely between different seed and different phantom materials so accurate simulation is needed. Methods: In this paper, a Monte Carlo simulation program toolkits-Geant4 has been used to calculate the dose distribution in different phantom materials around two kinds of brachytherapy source: 192Ir and 125I, respectively. Results: The radial dose function and anisotropy function has been calculated and analyzed detailedly based on the formula recommended by the American Association of Physics in Medicine Report of the Working Group 43(AAPM TG-43). Conclusions: (1) The radial dose function depends on p, en of photon in materials and the radial dose function of I25I fall down much more sharply than 192Ir. (2) The curves of the anisotropy function in water and bone phantom materials become more plain than in lung phantom while the radial distance increases. This phenomenon reflects a law that more attenuation and scatter in materials, the curve of anisotropy function is more plain.

  2. Development of a phantom to validate high-dose-rate brachytherapy treatment planning systems with heterogeneous algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S., E-mail: emoura@wisc.edu [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 and Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Micka, John A.; Hammer, Cliff G.; Culberson, Wesley S.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 (United States); Rostelato, Maria Elisa C. M.; Zeituni, Carlos A. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil)

    2015-04-15

    Purpose: This work presents the development of a phantom to verify the treatment planning system (TPS) algorithms used for high-dose-rate (HDR) brachytherapy. It is designed to measure the relative dose in a heterogeneous media. The experimental details used, simulation methods, and comparisons with a commercial TPS are also provided. Methods: To simulate heterogeneous conditions, four materials were used: Virtual Water™ (VM), BR50/50™, cork, and aluminum. The materials were arranged in 11 heterogeneity configurations. Three dosimeters were used to measure the relative response from a HDR {sup 192}Ir source: TLD-100™, Gafchromic{sup ®} EBT3 film, and an Exradin™ A1SL ionization chamber. To compare the results from the experimental measurements, the various configurations were modeled in the PENELOPE/penEasy Monte Carlo code. Images of each setup geometry were acquired from a CT scanner and imported into BrachyVision™ TPS software, which includes a grid-based Boltzmann solver Acuros™. The results of the measurements performed in the heterogeneous setups were normalized to the dose values measured in the homogeneous Virtual Water™ setup and the respective differences due to the heterogeneities were considered. Additionally, dose values calculated based on the American Association of Physicists in Medicine-Task Group 43 formalism were compared to dose values calculated with the Acuros™ algorithm in the phantom. Calculated doses were compared at the same points, where measurements have been performed. Results: Differences in the relative response as high as 11.5% were found from the homogeneous setup when the heterogeneous materials were inserted into the experimental phantom. The aluminum and cork materials produced larger differences than the plastic materials, with the BR50/50™ material producing results similar to the Virtual Water™ results. Our experimental methods agree with the PENELOPE/penEasy simulations for most setups and dosimeters. The

  3. High dose rate brachytherapy using custom made superficial mould applicators and Leipzig applicators for non melanoma localized skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, A. Cassio A.; Miziara, Daniela; Lima, Flavia Pedroso de; Miziara, Miguel

    2014-07-01

    Purpose: advances in technology and the commercial production of Leipzig applicators allowed High Dose Rate after-load brachytherapy (HDR-BT) to address a number of the challenges associated with the delivery of superficial radiation to treat localized non melanoma skin cancer (NMSK). We reviewed our uni-institutional experience on the treatment of NMSK with HDR-BT. Methods: data were collected retrospectively from patients attending the Radiation Oncology Department at AV Carvalho Insitute, Sao Paulo, Brazil. HDR-BT was done using the stepping source HDR 192Ir Microselectron (Nucletron BV). The planning target volume consisted of the macroscopic lesion plus a 5mm to 10mm margin.The depth of treatment was 0.5 cm in smaller (< 2.0 cm) tumors and 10 to 15 mm for lesions bigger than that. Results: Thirteen patients were treated with HDR-BT from June, 2007 to June 2013. The median age and follow up time were 72 (38-90) years old and 36 (range, 7-73) months, respectively. There a predominance of males (61.5%) and of patients referred for adjuvant treatment due positive surgical margins or because they have had only a excision biopsy without safety margins (61.5%). Six (46.2%) patients presented with squamous cell carcinoma and 7 (53.8%) patients presented with basal cell carcinoma. The median tumor size was 20 (range, 5-42) mm. Patients were treated with a median total dose of 40 Gy (range, 20 -60), given in 10 (range, 2-15) fractions, given daily or twice a week. All patients responded very well to treatment and only one patient has failed locally so far, after 38 months of the end of the irradiation. The crude and actuarial 3-year local control rates were 100% and 80%, respectively. Moist desquamation, grade 2 RTOG, was observed in 4 (30.8%) patients. Severe late complication, radiation-induced dyspigmentation, occurred in 2 patients and 1 of the patients also showed telangiectasia in the irradiated area. The cosmetic result was considered good in 84% (11/13) patients

  4. Irradiate Experiment of 192Ir in CARR

    Institute of Scientific and Technical Information of China (English)

    JIANG; Jun

    2013-01-01

    There is no possibility of occurrence on ebullition of subcooled nucleate in external surface that we designed,meantime temperature of internal component reach the designed is achieved in motion of the atomic reactor in steady-state,which is the critical requirements of China Advanced Research Reactor

  5. SU-E-T-212: Comparison of TG-43 Dosimetric Parameters of Low and High Energy Brachytherapy Sources Obtained by MCNP Code Versions of 4C, X and 5

    Energy Technology Data Exchange (ETDEWEB)

    Zehtabian, M; Zaker, N; Sina, S [Shiraz University, Shiraz, Fars (Iran, Islamic Republic of); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    Purpose: Different versions of MCNP code are widely used for dosimetry purposes. The purpose of this study is to compare different versions of the MCNP codes in dosimetric evaluation of different brachytherapy sources. Methods: The TG-43 parameters such as dose rate constant, radial dose function, and anisotropy function of different brachytherapy sources, i.e. Pd-103, I-125, Ir-192, and Cs-137 were calculated in water phantom. The results obtained by three versions of Monte Carlo codes (MCNP4C, MCNPX, MCNP5) were compared for low and high energy brachytherapy sources. Then the cross section library of MCNP4C code was changed to ENDF/B-VI release 8 which is used in MCNP5 and MCNPX codes. Finally, the TG-43 parameters obtained using the MCNP4C-revised code, were compared with other codes. Results: The results of these investigations indicate that for high energy sources, the differences in TG-43 parameters between the codes are less than 1% for Ir-192 and less than 0.5% for Cs-137. However for low energy sources like I-125 and Pd-103, large discrepancies are observed in the g(r) values obtained by MCNP4C and the two other codes. The differences between g(r) values calculated using MCNP4C and MCNP5 at the distance of 6cm were found to be about 17% and 28% for I-125 and Pd-103 respectively. The results obtained with MCNP4C-revised and MCNPX were similar. However, the maximum difference between the results obtained with the MCNP5 and MCNP4C-revised codes was 2% at 6cm. Conclusion: The results indicate that using MCNP4C code for dosimetry of low energy brachytherapy sources can cause large errors in the results. Therefore it is recommended not to use this code for low energy sources, unless its cross section library is changed. Since the results obtained with MCNP4C-revised and MCNPX were similar, it is concluded that the difference between MCNP4C and MCNPX is their cross section libraries.

  6. MO-D-BRD-00: Electronic Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  7. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette Benedicte;

    2006-01-01

    BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

  8. Interstitial brachytherapy for eyelid carcinoma. Outcome analysis in 60 patients

    Energy Technology Data Exchange (ETDEWEB)

    Krengli, M.; Deantonio, L. [University Hospital ' ' Maggiore della Carita' ' , Division of Radiotherapy, Novara (Italy); University of ' ' Piemonte Orientale' ' , Department of Translational Medicine, Novara (Italy); Masini, L.; Filomeno, A.; Gambaro, G. [University Hospital ' ' Maggiore della Carita' ' , Division of Radiotherapy, Novara (Italy); Comoli, A.M. [University Hospital Maggiore della Carita, Ophthalmology, Novara (Italy); Negri, E. [University Hospital Maggiore della Carita, Medical Physics, Novara (Italy)

    2014-03-15

    Eyelid cancer is a therapeutic challenge due to the cosmetic and functional implications of this anatomical region and the objectives of therapy are tumor control, functional and cosmetic outcome. The present study was performed to analyze local control, toxicity, functional and cosmetic results in patients with eyelid carcinoma treated by interstitial brachytherapy. In this study 60 patients with eyelid carcinoma were treated by interstitial brachytherapy using iridium ({sup 192}Ir) wires with a linear activity of 1.2-1.7 mCi/cm. The prescription dose was 51-70 Gy (mean 65 Gy, median 66 Gy). Of the 60 patients 51 (85.0 %) had received no prior treatment, 4 (6.7 %) had received previous surgery with positive or close margins and 5 (8.3 %) had suffered local recurrence after surgery. Of the tumors 52 (86.7 %) were basal cell carcinoma, 7 (11.7 %) squamous cell carcinoma and 1 (1.7 %) Merkel cell carcinoma. Clinical stage of the 51 previously untreated tumors was 38 T1N0, 12 T2N0 and 1 T3N0. Mean follow-up was 92 months (range 6-253 months). Local control was maintained in 96.7 % of patients. Late effects higher than grade 2 were observed in 3.0 % of cases. Functional and cosmetic outcomes were optimal in 68.4 % of patients. Interstitial brachytherapy for carcinoma of the eyelid can achieve local control, cosmetic and functional results comparable to those of surgery. (orig.) [German] Das Karzinom des Augenlids stellt aufgrund der funktionellen und kosmetischen Beeintraechtigungen dieser anatomischen Region eine therapeutische Herausforderung dar. Ziele der Therapie sind sowohl die Tumorkontrolle als auch ein gutes funktionelles und kosmetisches Ergebnis. Lokale Kontrolle, Toxizitaet sowie funktionelle und kosmetische Ergebnisse bei Patienten mit Karzinom des Augenlids, die mit interstitieller Brachytherapie behandelt wurden, sollten analysiert werden. Sechzig Patienten mit Karzinom des Augenlids wurden mit interstitieller Brachytherapie mit Iridium-192-Draehten

  9. Divergence of Cs-137 sources fluence used in brachytherapy; Divergencia da fluencia de fontes de Cs-137 usadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Vianello, E.A.; Almeida, C.E. de [Laboratorio de Ciencias Radiologicas- LCR-DBB (UERJ). R. Sao Francisco Xavier, 524- Pav. HLC, sala 136 terreo- CEP 20.550- 013. Rio de Janeiro (Brazil)

    1998-12-31

    In this work the experimental determination of correction factor for fluence divergence (kln) of linear Cs-137 sources CDCS J4, with Farmer ionization chamber model 2571 in a central and perpendicular plan to source axis, for distances range from 1 to 7 cm., has been presented. The experimental results were compared to calculating by Kondo and Randolph (1960) isotropic theory and Bielajew (1990) anisotropic theory. (Author)

  10. Patient release criteria for low dose rate brachytherapy implants.

    Science.gov (United States)

    Boyce, Dale E; Sheetz, Michael A

    2013-04-01

    A lack of consensus regarding a model governing the release of patients following sealed source brachytherapy has led to a set of patient release policies that vary from institution to institution. The U.S. Nuclear Regulatory Commission has issued regulatory guidance on patient release in NUREG 1556, Volume 9, Rev. 2, Appendix U, which allows calculation of release limits following implant brachytherapy. While the formalism presented in NUREG is meaningful for the calculation of release limits in the context of relatively high energy gamma emitters, it does not estimate accurately the effective dose equivalent for the common low dose rate brachytherapy sources Cs, I, and Pd. NUREG 1556 states that patient release may be based on patient-specific calculations as long as the calculation is documented. This work is intended to provide a format for patient-specific calculations to be used for the consideration of patients' release following the implantation of certain low dose rate brachytherapy isotopes.

  11. Design and optimization of a brachytherapy robot

    Science.gov (United States)

    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. Shielding hospital rooms for brachytherapy patients: design, regulatory and cost/benefit factors.

    Science.gov (United States)

    Gitterman, M; Webster, E W

    1984-03-01

    The current regulations of the U.S. Nuclear Regulatory Commission (NRC) normally require limitation of radiation exposure in any part of unrestricted occupied areas to 2 mrem in any one hour and to 100 mrem in 7 days. To meet these limits when patients are treated therapeutically with radioactive materials, it is advisable to designate specific rooms in a hospital and often necessary to incorporate substantial costly shielding into one or more walls and the room door. Plans have been formulated for shielding existing hospital rooms housing brachytherapy patients receiving 192Ir and 137Cs therapy in order to meet the above NRC requirements for adjacent corridors and rooms. Typical shielding thicknesses required are 4-6 in. of concrete for certain walls and 1/4 in. of lead in the doors. Shielding costs are approx. $6000 per room for one shielded wall and a shielded door. Applying recent estimates of the cancer risk from low-level gamma radiation, the cost of shielding per cancer fatality averted has been estimated to range from $1.8 million to $10.9 million. Cost/benefit comparisons with many other life-saving activities suggest that these costs and the application of the 2 mrem/hr limit which necessitated them are not justified.

  13. Radiation transmission data for radionuclides and materials relevant to brachytherapy facility shielding.

    Science.gov (United States)

    Papagiannis, P; Baltas, D; Granero, D; Pérez-Calatayud, J; Gimeno, J; Ballester, F; Venselaar, J L M

    2008-11-01

    To address the limited availability of radiation shielding data for brachytherapy as well as some disparity in existing data, Monte Carlo simulation was used to generate radiation transmission data for 60Co, 137CS, 198Au, 192Ir 169Yb, 170Tm, 131Cs, 125I, and 103pd photons through concrete, stainless steel, lead, as well as lead glass and baryte concrete. Results accounting for the oblique incidence of radiation to the barrier, spectral variation with barrier thickness, and broad beam conditions in a realistic geometry are compared to corresponding data in the literature in terms of the half value layer (HVL) and tenth value layer (TVL) indices. It is also shown that radiation shielding calculations using HVL or TVL values could overestimate or underestimate the barrier thickness required to achieve a certain reduction in radiation transmission. This questions the use of HVL or TVL indices instead of the actual transmission data. Therefore, a three-parameter model is fitted to results of this work to facilitate accurate and simple radiation shielding calculations.

  14. Verification and analysis of the positioning of a source of brachytherapy high dose within an applicator gynecological interstitial fletcher Utrecht TC/RM; Verificacion y analysis del posicionamiento de una fuente de braquiterapia de alta tasa de dosis dentro de un aplicador ginecologico fletcher intersticial UTRECHT TC/RM

    Energy Technology Data Exchange (ETDEWEB)

    Panedo Cobos, J. M.; Garcia castejon, M. A.; Huertas Martinez, C.; Gomez-Tejedor Alonso, S.; Rincon Perez, M.; Luna Tirado, J.; Perez Casas, A. M.

    2013-07-01

    Applicators are guides that circulate and are located within the patient brachytherapy sources. Applicators can suffer mechanical deformations due to processes of sterilization or shock, which may result in that the source do not place within these very precise and coincides with the planned. In these cases the planned treatment deviate actually managed. The object of this study is to verify that the position of the source into the dispenser coincides with the planned position, with a procedure that is described. (Author)

  15. [Edge effect and late thrombosis -- inevitable complications of vascular brachytherapy?].

    Science.gov (United States)

    Schiele, T M; Staber, L; Kantlehner, R; Pöllinger, B; Dühmke, E; Theisen, K; Klauss, V

    2002-11-01

    Restenosis is the limiting entity after percutaneous coronary angioplasty. Vascular brachytherapy for the treatment of in-stent restenosis has been shown to reduce the repeat restenosis rate and the incidence of major adverse events in several randomized trials. Besides the beneficial effects, brachytherapy yielded some unwanted side effects. The development of new stenoses at the edges of the target lesion treated with radiation is termed edge effect. It occurs after afterloading brachytherapy as well as after implantation of radioactive stents. It is characterized by extensive intimal hyperplasia and negative remodeling. As contributing factors the axial dose fall-off, inherent to all radioactive sources, and the application of vessel wall trauma by angioplasty have been identified. The combination of both factors, by insufficient overlap of the radiation length over the injured vessel segment, has been referred to as geographic miss. It has been shown to be associated with a very high incidence of the edge effect. Avoidance of geographic miss is strongly recommended in vascular brachytherapy procedures. Late thrombosis after vascular brachytherapy is of multifactorial origin. It comprises platelet recruitment, fibrin deposition, disturbed vasomotion, non-healing dissection and stent malapposition predisposing to turbulent blood flow. The strongest predictors for late thrombosis are premature discontinuation of antiplatelet therapy and implantation of new stents during the brachytherapy procedure. With a consequent and prolonged antiplatelet therapy, the incidence of late thrombosis has been reduced to placebo levels. Edge effect and late thrombosis represent unwanted side effects of vascular brachytherapy. By means of a thorough treatment planning and prolonged antiplatelet therapy their incidences can be largely reduced. With regard to the very favorable net effect, they do not constitute relevant limitations of vascular brachytherapy.

  16. Development of a multi-electrode extrapolation chamber as a prototype of a primary standard for the realization of the unit of the absorbed dose to water for beta brachytherapy sources

    CERN Document Server

    Bambynek, M

    2002-01-01

    The prototype of a primary standard has been developed, built and tested, which enables the realization of the unit of the absorbed dose to water for beta brachytherapy sources. In the course of the development of the prototype, the recommendations of the American Association of Physicists in Medicine (AAPM) Task Group 60 (TG60) and the Deutsche Gesellschaft fuer Medizinische Physik (DGMP) Arbeitskreis 18 (AK18) were taken into account. The prototype is based on a new multi-electrode extrapolation chamber (MEC) which meets, in particular, the requirements on high spatial resolution and small uncertainty. The central part of the MEC is a segmented collecting electrode which was manufactured in the clean room center of PTB by means of electron beam lithography on a wafer. A precise displacement device consisting of three piezoelectric macrotranslators has been incorporated to move the wafer collecting electrode against the entrance window. For adjustment of the wafer collecting electrode parallel to the entranc...

  17. Dosimetric analysis and comparison of IMRT and HDR brachytherapy in treatment of localized prostate cancer.

    Science.gov (United States)

    Murali, V; Kurup, P G G; Mahadev, P; Mahalakshmi, S

    2010-04-01

    Radical radiotherapy is one of the options for the management of prostate cancer. In external beam therapy, 3D conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT) are the options for delivery of increased radiation dose, as vital organs are very close to the prostate and a higher dose to these structures leads to an increased toxicity. In brachytherapy, low dose rate brachytherapy with permanent implant of radioactive seeds and high dose rate brachytherapy (HDR) with remote after loaders are available. A dosimetric analysis has been made on IMRT and HDR brachytherapy plans. Ten cases from each IMRT and HDR brachytherapy have been taken for the study. The analysis includes comparison of conformity and homogeneity indices, D100, D95, D90, D80, D50, D10 and D5 of the target. For the organs at risk (OAR), namely rectum and bladder, V100, V90 and V50 are compared. In HDR brachytherapy, the doses to 1 cc and 0.1 cc of urethra have also been studied. Since a very high dose surrounds the source, the 300% dose volumes in the target and within the catheters are also studied in two plans, to estimate the actual volume of target receiving dose over 300%. This study shows that the prescribed dose covers 93 and 92% of the target volume in IMRT and HDR brachytherapy respectively. HDR brachytherapy delivers a much lesser dose to OAR, compared to the IMRT. For rectum, the V50 in IMRT is 34.0cc whilst it is 7.5cc in HDR brachytherapy. With the graphic optimization tool in HDR brachytherapy planning, the dose to urethra could be kept within 120% of the target dose. Hence it is concluded that HDR brachytherapy may be the choice of treatment for cancer of prostate in the early stage.

  18. Dosimetric analysis and comparison of IMRT and HDR brachytherapy in treatment of localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Murali V

    2010-01-01

    Full Text Available Radical radiotherapy is one of the options for the management of prostate cancer. In external beam therapy, 3D conformal radiotherapy (3DCRT and intensity modulated radiotherapy (IMRT are the options for delivery of increased radiation dose, as vital organs are very close to the prostate and a higher dose to these structures leads to an increased toxicity. In brachytherapy, low dose rate brachytherapy with permanent implant of radioactive seeds and high dose rate brachytherapy (HDR with remote after loaders are available. A dosimetric analysis has been made on IMRT and HDR brachytherapy plans. Ten cases from each IMRT and HDR brachytherapy have been taken for the study. The analysis includes comparison of conformity and homogeneity indices, D100, D95, D90, D80, D50, D10 and D5 of the target. For the organs at risk (OAR, namely rectum and bladder, V100, V90 and V50 are compared. In HDR brachytherapy, the doses to 1 cc and 0.1 cc of urethra have also been studied. Since a very high dose surrounds the source, the 300% dose volumes in the target and within the catheters are also studied in two plans, to estimate the actual volume of target receiving dose over 300%. This study shows that the prescribed dose covers 93 and 92% of the target volume in IMRT and HDR brachytherapy respectively. HDR brachytherapy delivers a much lesser dose to OAR, compared to the IMRT. For rectum, the V50 in IMRT is 34.0cc whilst it is 7.5cc in HDR brachytherapy. With the graphic optimization tool in HDR brachytherapy planning, the dose to urethra could be kept within 120% of the target dose. Hence it is concluded that HDR brachytherapy may be the choice of treatment for cancer of prostate in the early stage.

  19. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy; Preparacion y determinacion del kerma de fuentes de iridio-192 de baja tasa de dosis para braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Tendilla, J.I.; Tovar M, V.; Mitsoura, E.; Aguilar H, F.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045-1, Salazar, Esrado de Mexico, D.F. (Mexico)

    2000-07-01

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 {+-} 0.531 M Bq and kerma in air 0.03200 {+-} 0.00006 m Gy m/h A. (Author)

  20. Importance of the neutrons kerma coefficient in the planning of Brachytherapy treatments with Cf-252 sources; Importancia del coeficiente de kerma de neutrones en la planeacion de tratamientos de Braquiterapia con fuentes de Cf-252

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Balcazar G, M. [ININ, 52045 Ocoyocac, Estado de Mexico (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana, 09000 Mexico D.F. (Mexico); Francois L, J.L. [UNAM, 04500 Mexico D.F. (Mexico)]. e-mail: lpg@nuclear.inin.mx

    2006-07-01

    The Cf-252 is a fast neutrons emitting radioisotope by spontaneous fission that can be used as sealed source in medicine applications, industry and research. Commercially its offer sources of different sizes, compact and with a fast neutrons emission of the order of 10{sup 6} n/s-{mu}g and an energy spectra that presents respectively maxim and average energy in 2.1 MeV and 0.7 MeV. In medicine new applications are being developed for the treatment of patient with hypoxic and voluminous tumors, where the therapy with photons has not given positive results, as well as for the protocols of therapy treatment by boron neutron capture, where very small sources of Cf-252 will be used with the interstitial brachytherapy technique of high and low dose rate. In this work an analysis of how the small differences that exist in the elementary composition of 4 wicked tumors, 4 ICRU healthy tissues and 3 substitute materials of ICRU tissue used in dosimetry are presented, its generate changes in the neutrons kerma coefficient in function of the energy and consequently in the absorbed dose in the interval of 11 eV to 29 MeV. These differences can produce maximum variations of the neutron kerma coefficients ratio for E{sub n} > 1 keV of the one: 15% tumor/ICRU guest healthy tissue, 12% ICRU tumor/muscle, 12% ICRU healthy tissues ICRU/ICRU muscle, 22% substitutes tissue/tumor and 22% ICRU substitutes tissue/muscle. Also, it was found that the average value of the neutrons kerma coefficient for the 4 wicked tumors is from 6% to 7% smaller that the average value for the soft tissue in the interval energy of interest for therapy with fast neutrons with E{sub n} > 1 MeV. These results have a special importance during the planning process of brachytherapy treatments with sources of {sup 252}Cf, to optimize and to individualize the patients treatments. (Author)

  1. Avaliação da biodegradação de matrizes porosas à base de hidroxiapatita para aplicação como fontes radioativas em braquiterapia Evaluation of the biodegradation of porous hydroxyapatite matrices for application as radioactive sources in brachytherapy

    Directory of Open Access Journals (Sweden)

    Kássio André Lacerda

    2009-01-01

    Full Text Available Porous ceramic materials based on calcium phosphate compounds (CPC have been studied aiming at different biomedical applications such as implants, drug delivery systems and radioactive sources for brachytherapy. Two kinds of hydroxyapatite (HAp powders and their ceramic bodies were characterized by a combination of different techniques (XRF, BET method, SEM, ICP/AES and neutron activation analysis - NAA to evaluate their physico-chemical and microstructural characteristics in terms of chemical composition, segregated phases, microstructure, porosity, chemical and thermal stability, biodegradation and incorporation of substances in their structures. The results revealed that these systems presented potential for use as porous biodegradable radioactive sources able to be loaded with a wide range of radionuclides for cancer treatment by the brachytherapy technique.

  2. Validation of GPUMCD for low-energy brachytherapy seed dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hissoiny, Sami; Ozell, Benoit; Despres, Philippe; Carrier, Jean-Francois [Ecole polytechnique de Montreal, Departement de genie informatique et genie logiciel, 2500 chemin de Polytechnique, Montreal, QC, H3T 1J4 (Canada); Departement de radio-oncologie, Centre hospitalier universitaire de Quebec (CHUQ), 11 Cote du Palais, Quebec, QC, G1R 2J6 (Canada); Departement de physique, Universite de Montreal, Montreal, QC (Canada) and Departement de radio-oncologie and Centre de recherche du CHUM, Centre hospitalier de l' Universite de Montreal (CHUM), Montreal, QC, H2L 4M1 (Canada)

    2011-07-15

    Purpose: To validate GPUMCD, a new package for fast Monte Carlo dose calculations based on the GPU (graphics processing unit), as a tool for low-energy single seed brachytherapy dosimetry for specific seed models. As the currently accepted method of dose calculation in low-energy brachytherapy computations relies on severe approximations, a Monte Carlo based approach would result in more accurate dose calculations, taking in to consideration the patient anatomy as well as interseed attenuation. The first step is to evaluate the capability of GPUMCD to reproduce low-energy, single source, brachytherapy calculations which could ultimately result in fast and accurate, Monte Carlo based, brachytherapy dose calculations for routine planning. Methods: A mixed geometry engine was integrated to GPUMCD capable of handling parametric as well as voxelized geometries. In order to evaluate GPUMCD for brachytherapy calculations, several dosimetry parameters were computed and compared to values found in the literature. These parameters, defined by the AAPM Task-Group No. 43, are the radial dose function, the 2D anisotropy function, and the dose rate constant. These three parameters were computed for two different brachytherapy sources: the Amersham OncoSeed 6711 and the Imagyn IsoStar IS-12501. Results: GPUMCD was shown to yield dosimetric parameters similar to those found in the literature. It reproduces radial dose functions to within 1.25% for both sources in the 0.5< r <10 cm range. The 2D anisotropy function was found to be within 3% at r = 5 cm and within 4% at r = 1 cm. The dose rate constants obtained were within the range of other values reported in the literature.Conclusion: GPUMCD was shown to be able to reproduce various TG-43 parameters for two different low-energy brachytherapy sources found in the literature. The next step is to test GPUMCD as a fast clinical Monte Carlo brachytherapy dose calculations with multiple seeds and patient geometry, potentially providing

  3. Uncertainty analysis in MCNP5 calculations for brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gerardy, I., E-mail: gerardy@isib.be [Institut Superieur Industriel de Bruxelles, 150, Rue Royale, B-1000 Brussels (Belgium); Rodenas, J.; Gallardo, S. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia (Spain)

    2011-08-15

    The Monte Carlo (MC) method can be applied to simulate brachytherapy treatment planning. The MCNP5 code gives, together with results, a statistical uncertainty associated with them. However, the latter is not the only existing uncertainty related to the simulation and other uncertainties must be taken into account. A complete analysis of all sources of uncertainty having some influence on results of the simulation of brachytherapy treatment is presented in this paper. This analysis has been based on the recommendations of the American Association for Physicist in Medicine (AAPM) and of the International Standard Organisation (ISO).

  4. Irradiation and dosimetry of Nitinol stent for renal artery brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Arbabi, Azim [Science and Research Campus, Islamic Azad University, P.O. Box 14515-775, Tehran (Iran, Islamic Republic of); Shahid Beheshti Medical University, P.O. Box 14335-1419, Tehran (Iran, Islamic Republic of); Sadeghi, Mahdi [Science and Research Campus, Islamic Azad University, P.O. Box 14515-775, Tehran (Iran, Islamic Republic of); Nuclear Medicine Research Group, Agricultural, Medical and Industrial Research School, P.O. Box 31485-498, Karaj (Iran, Islamic Republic of)], E-mail: msadeghi@nrcam.org; Joharifard, Mahdi [Science and Research Campus, Islamic Azad University, P.O. Box 14515-775, Tehran (Iran, Islamic Republic of)

    2009-01-15

    This study was conducted to assess the suitability of {sup 48}V radioactive stent for use in renal artery brachytherapy. A nickel-titanium alloy Nitinol stent was irradiated over the proton energy range of up to 8.5 MeV, to obtain {sup 48}V. The depth dose distribution analysis of the activated stent was done with TLD-700GR in a Perspex phantom. We investigated a unique mixed gamma/beta brachytherapy source of {sup 48}V. For a 10 mm outer-diameter {sup 48}V stent, the average measured dose rate to vessel was 37 mGy/h. The dosimetry results of the {sup 48}V stent suggest that the stent is suitable for use in renal artery brachytherapy.

  5. Determination of the dose around an ovoid for treatments in intracavitary brachytherapy Hdr; Determinacion de la dosis alrededor de un ovoide para tratamientos en braquiterapia intracavitaria HDR

    Energy Technology Data Exchange (ETDEWEB)

    Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Velasco V, R. A. E. [Hospital Central Militar, Periferico y Ejercito Nacional s/n, Lomas de Sotelo, 11200 Mexico D. F. (Mexico); Serrano F, A. K. [Hospital Juarez de Mexico, Av. Instituto Politecnico Nacional No. 5190, Col. Magdalena de las Salinas, 03220 Mexico D. F. (Mexico); Azorin N, J., E-mail: trivera@ipn.m [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2010-09-15

    On this work the results of the dosimetric measurements are presented around an ovoid of 2 cm diameter. The measurements were carried out using a water mannequin, an ovoid, a radiation gamma source of {sup 192}Ir and thermoluminescent dosemeters. The dosimetry was realized in the direction of the rectum and bladder. To know the effect of the shielding of the devices type Manchester in the dose, the thermoluminescent dosemeters were irradiated to a radiation gamma source of {sup 192}Ir contained in the Gamma med Plus equipment. The planning was realized normalizing the calculation to 2.5 cm from the applicator center on the transverse plane (2.5, 0, 0). The results show that the dose distribution for an ovoid without shielding is more uniform in the transversal plane to the source axis. The results were compared with the calculated results by means of the planning system BrachyVision. While the absorbed dose distribution around an ovoid with shielding is completely anisotropic. This anisotropic is due to the shielding. (Author)

  6. Multihelix rotating shield brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States); Kim, Yusung; Flynn, Ryan T., E-mail: ryan-flynn@uiowa.edu [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Wu, Xiaodong [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 and Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States)

    2015-11-15

    Purpose: To present a novel brachytherapy technique, called multihelix rotating shield brachytherapy (H-RSBT), for the precise angular and linear positioning of a partial shield in a curved applicator. H-RSBT mechanically enables the dose delivery using only linear translational motion of the radiation source/shield combination. The previously proposed approach of serial rotating shield brachytherapy (S-RSBT), in which the partial shield is rotated to several angular positions at each source dwell position [W. Yang et al., “Rotating-shield brachytherapy for cervical cancer,” Phys. Med. Biol. 58, 3931–3941 (2013)], is mechanically challenging to implement in a curved applicator, and H-RSBT is proposed as a feasible solution. Methods: A Henschke-type applicator, designed for an electronic brachytherapy source (Xoft Axxent™) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles and 116° asymmetric zenith angle, is proposed. The interior wall of the applicator contains six evenly spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. For each patient, the total number of emission angles was held nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. Treatment delivery time and tumor coverage (D{sub 90} of HR-CTV) were the two metrics used as the basis for evaluation and

  7. Use of Monte Carlo Methods in brachytherapy; Uso del metodo de Monte Carlo en braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Granero Cabanero, D.

    2015-07-01

    The Monte Carlo method has become a fundamental tool for brachytherapy dosimetry mainly because no difficulties associated with experimental dosimetry. In brachytherapy the main handicap of experimental dosimetry is the high dose gradient near the present sources making small uncertainties in the positioning of the detectors lead to large uncertainties in the dose. This presentation will review mainly the procedure for calculating dose distributions around a fountain using the Monte Carlo method showing the difficulties inherent in these calculations. In addition we will briefly review other applications of the method of Monte Carlo in brachytherapy dosimetry, as its use in advanced calculation algorithms, calculating barriers or obtaining dose applicators around. (Author)

  8. Developing a Verification and Training Phantom for Gynecological Brachytherapy System

    Directory of Open Access Journals (Sweden)

    Mahbobeh Nazarnejad

    2012-03-01

    Full Text Available Introduction Dosimetric accuracy is a major issue in the quality assurance (QA program for treatment planning systems (TPS. An important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. In brachytherapy (BT of gynecological (Gyn cancer it is usual to insert a combination of tandem and ovoid applicators with a complicated geometry which makes their dosimetry verification difficult and important. Therefore, evaluation and verification of dose distribution is necessary for accurate dose delivery to the patients. Materials and Methods The solid phantom was made from Perspex slabs as a tool for intracavitary brachytherapy dosimetric QA. Film dosimetry (EDR2 was done for a combination of ovoid and tandem applicators introduced by Flexitron brachytherapy system. Treatment planning was also done with Flexiplan 3D-TPS to irradiate films sandwiched between phantom slabs. Isodose curves obtained from treatment planning system and the films were compared with each other in 2D and 3D manners. Results The brachytherapy solid phantom was constructed with slabs. It was possible to insert tandems and ovoids loaded with radioactive source of Ir-192 subsequently. Relative error was 3-8.6% and average relative error was 5.08% in comparison with the films and TPS isodose curves. Conclusion Our results showed that the difference between TPS and the measurements is well within the acceptable boundaries and below the action level according to AAPM TG.45. Our findings showed that this phantom after minor corrections can be used as a method of choice for inter-comparison analysis of TPS and to fill the existing gap for accurate QA program in intracavitary brachytherapy. The constructed phantom also showed that it can be a valuable tool for verification of accurate dose delivery to the patients as well as training for brachytherapy residents and physics students.

  9. Long term effect of cervix carcinoma treated by HDR 192 Ir afterloding intracavitory radiotherapy combined with external irradiation.%高剂量率192Ir后装腔内加外照射治疗宫颈癌的远期疗效分析

    Institute of Scientific and Technical Information of China (English)

    王青; 侯晓玲; 赵淑红

    2001-01-01

    Objective To analyze retrosrectively long- term effect of cervix carcinona treated by HDR 192Ir afterloading intracavitory radiotherapy combined with external irradiation. Methods From Mar 1993 to Dec 1994, 128 cases of cervix cancer(age from 29 years to 80 years) were treated with combination of external irradiation and HDR 192Ir afterloading intracavitory radiotherapy. 47 cases were stage Ⅱ and 81 were stage Ⅲ. The dose of external radiotherapy was 40 Gy or 50 Gy and afterloading irradiation was given in 6 or 7 fractions of 8 Gy. Results The overall local tumor control was 94.5%, the 1,3,5 year survival rates were 91.61%, 81.89%and 67.36%. The 1,3,5 year survival rates of stage Ⅱ and stage Ⅲ cases were 95.28% and 89. 47%, 87.19% and 79.50%, 72.76% and 64.95% (P>0.05). The rate of severe complications was 7.03% (9/128). Conclusion HDR 192Ir afterloading intracavitory radiotherapy combined with external irradiation for cervix carcinoma is effective and less side effects.%目的分析高剂量率192Ir后装腔内加外照射治疗宫颈癌的远期疗效及并发症。方法对128例Ⅱ、Ⅲ期放疗后宫颈癌进行了回顾分析。其中Ⅱ期47例,Ⅲ期81例。全盆腔外照射Dr20Gy/10次,全盆中间挡铅4cmDr20Gy~30Gy/10次~15次;后装A点剂量48Gy~56Gy/6次~7次。结果 1、3、5年生存率分别为91.61%、81.8%和67.36%;Ⅱ、Ⅲ期1、3、5年生存率无统计学差异(P>0.05);远期严重并发症的发生率7.03%(9/128)。结论高剂量率192Ir后装腔内加外照射治疗宫颈癌疗效肯定,并发症少。盆腔局部复发仍是放疗失败的主要原因。

  10. SU-E-J-270: Study of PET Response to HDR Brachytherapy of Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, R; Le, Y; Armour, E; Efron, J; Azad, N; Wahl, R; Gearhart, S; Herman, J [Johns Hopkins University, Baltimore, MD (United States)

    2014-06-01

    Purpose: Dose-response studies in radiation therapy are typically using single response values for tumors across ensembles of tumors. Using the high dose rate (HDR) treatment plan dose grid and pre- and post-therapy FDG-PET images, we look for correlations between voxelized dose and FDG uptake response in individual tumors. Methods: Fifteen patients were treated for localized rectal cancer using 192Ir HDR brachytherapy in conjunction with surgery. FDG-PET images were acquired before HDR therapy and 6–8 weeks after treatment (prior to surgery). Treatment planning was done on a commercial workstation and the dose grid was calculated. The two PETs and the treatment dose grid were registered to each other using non-rigid registration. The difference in PET SUV values before and after HDR was plotted versus absorbed radiation dose for each voxel. The voxels were then separated into bins for every 400 cGy of absorbed dose and the bin average values plotted similarly. Results: Individual voxel doses did not correlate with PET response; however, when group into tumor subregions corresponding to dose bins, eighty percent of the patients showed a significant positive correlation (R2 > 0) between PET uptake difference in the targeted region and the absorbed dose. Conclusion: By considering larger ensembles of voxels, such as organ average absorbed dose or the dose bins considered here, valuable information may be obtained. The dose-response correlations as measured by FDG-PET difference potentially underlines the importance of FDG-PET as a measure of response, as well as the value of voxelized information.

  11. Preparation of (103)Pd brachytherapy seeds by electroless plating of (103)Pd onto carbon bars.

    Science.gov (United States)

    Li, Zhong-Yong; Gao, Hui-Bo; Deng, Xue-Song; Zhou, Leng; Zhang, Wen-Hui; Han, Lian-Ge; Jin, Xiao-Hai; Cui, Hai-Ping

    2015-09-01

    A method for preparing (103)Pd brachytherapy seeds is reported. The key of the method was to deposit (103)Pd onto carbon bars by electroless plating so as to prepare source cores. After each carbon bar with (103)Pd was sealed in a titanium capsule, the (103)Pd seeds were fabricated. This paper provides valuable experiences and data for the preparation of (103)Pd brachytherapy seeds.

  12. Direction-Modulated Brachytherapy for High-Dose-Rate Treatment of Cervical Cancer. I: Theoretical Design

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dae Yup [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California (United States); Webster, Matthew J. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Department of Physics, University of California San Diego, La Jolla, California (United States); Scanderbeg, Daniel J.; Yashar, Catheryn; Choi, Dongju; Song, Bongyong [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Devic, Slobodan [Medical Physics Unit, McGill University, Montréal, Québec (Canada); Department of Radiation Oncology, Jewish General Hospital, Montréal, Québec (Canada); Ravi, Ananth [Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Song, William Y., E-mail: wyjsong@gmail.com [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Department of Medical Physics, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)

    2014-07-01

    Purpose: To demonstrate that utilization of the direction-modulated brachytherapy (DMBT) concept can significantly improve treatment plan quality in the setting of high-dose-rate (HDR) brachytherapy for cervical cancer. Methods and Materials: The new, MRI-compatible, tandem design has 6 peripheral holes of 1.3-mm diameter, grooved along a nonmagnetic tungsten-alloy rod (ρ = 18.0 g/cm{sup 3}), enclosed in Delrin tubing (polyoxymethylene, ρ = 1.41 g/cm{sup 3}), with a total thickness of 6.4 mm. The Monte Carlo N-Particle code was used to calculate the anisotropic {sup 192}Ir dose distributions. An in-house-developed inverse planning platform, geared with simulated annealing and constrained-gradient optimization algorithms, was used to replan 15 patient cases (total 75 plans) treated with a conventional tandem and ovoids (T and O) applicator. Prescription dose was 6 Gy. For replanning, we replaced the conventional tandem with that of the new DMBT tandem for optimization but left the ovoids in place and kept the dwell positions as originally planned. All DMBT plans were normalized to match the high-risk clinical target volume V100 coverage of the T and O plans. Results: In general there were marked improvements in plan quality for the DMBT plans. On average, D2cc for the bladder, rectum, and sigmoid were reduced by 0.59 ± 0.87 Gy (8.5% ± 28.7%), 0.48 ± 0.55 Gy (21.1% ± 27.2%), and 0.10 ± 0.38 Gy (40.6% ± 214.9%) among the 75 plans, with best single-plan reductions of 3.20 Gy (40.8%), 2.38 Gy (40.07%), and 1.26 Gy (27.5%), respectively. The high-risk clinical target volume D90 was similar, with 6.55 ± 0.96 Gy and 6.59 ± 1.06 Gy for T and O and DMBT, respectively. Conclusions: Application of the DMBT concept to cervical cancer allowed for improved organ at risk sparing while achieving similar target coverage on a sizeable patient population, as intended, by maximally utilizing the anatomic information contained in 3-dimensional

  13. Radiological protection on interstitial brachytherapy and dose determination and exposure rate of an Ir-192 source through the MCNP-4B; Proteccion radiologica en braquiterapia intersticial y determinacion de la dosis y tasa de exposicion de una fuente de Ir-192 mediante el MCNP-4B

    Energy Technology Data Exchange (ETDEWEB)

    Morales L, M.E. [INEN, Av. Angamos Este 2520- Surquillo, Lima (Peru)

    2006-07-01

    The present work was carried out in the Neurological Sciences Institute having as objective to determine the dose and the rate of exhibition of the sources of Iridium 192, Iodine 125 and Palladium 103; which are used to carry out implant in the Interstitial Brachytherapy according to the TG43. For it we carry out a theoretical calculation, its are defined in the enter file: the geometry, materials of the problem and the radiation source, etc; in the MCNP-4B Monte Carlo code, considering a punctual source and for the dose determination we simulate thermoluminescent dosemeters (TLD): at 5 cm, 50 cm, 100 cm and 200 cm of the source. Our purpose is to analyze the radioprotection measures that should take into account in this Institute in which are carried out brain biopsies using a Micro mar stereotactic mark, and in a near future with the collaboration of a doctor and a cuban physique seeks to be carried out the Interstitial Brachytherapy technique with sources of Ir-192 for patient with tumors like glioblastoma, astrocytoma, etc. (Author)

  14. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  15. Brachytherapy in Gynecologic Cancers: Why Is It Underused?

    Science.gov (United States)

    Han, Kathy; Viswanathan, Akila N

    2016-04-01

    Despite its established efficacy, brachytherapy is underused in the management of cervical and vaginal cancers in some parts of the world. Possible reasons for the underutilization of brachytherapy include the adoption of less invasive techniques, such as intensity-modulated radiotherapy; reimbursement policies favoring these techniques over brachytherapy; poor physician or patient access to brachytherapy; inadequate maintenance of brachytherapy skills among practicing radiation oncologists; transitioning to high-dose-rate (HDR) brachytherapy with increased time requirements; and insufficient training of radiation oncology residents.

  16. Brachytherapy for prostate cancer: Comparative characteristics of procedures

    Directory of Open Access Journals (Sweden)

    S. V. Kanaev

    2015-01-01

    Full Text Available The introduction of interstitial radiation sources is the «youngest» of the radical method of treatment of patients with prostate cancer (PC. The high level of efficiency comparable to prostatectomy at a significantly lower rate of complications causes rapid growth of clinical use of brachytherapy (BT. Depending on the radiation source and the mode of administration into the prostate gland are two types BT – high-dose rate (temporary (HDR-BT and low-dose rate (permanent (LDR-BT brachytherapy. At the heart of these two methods are based on a single principle of direct effect of the quantum gamma radiation on the area of interest. However, the differences between the characteristics of isotopes used and technical aspects of the techniques cause the difference in performance and complication rates for expression HDR-BT and LDR-BT.

  17. In vivo dosimetry in brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Beddar, Sam; Andersen, Claus Erik;

    2013-01-01

    In vivo dosimetry (IVD) has been used in brachytherapy (BT) for decades with a number of different detectors and measurement technologies. However, IVD in BT has been subject to certain difficulties and complexities, in particular due to challenges of the high-gradient BT dose distribution and th...

  18. SU-E-T-462: Impact of the Radiochromic Film Energy Response On Dose Measurements of Low Energy Electronic Brachytherapy Sources

    Energy Technology Data Exchange (ETDEWEB)

    Liang, L; Bekerat, H; Tomic, N; DeBlois, F; Devic, S [Jewish General Hospital, Medical Physics Unit, McGill University, Montreal, QC (Canada); Morcos, M [Vantage Oncology, Corona, CA (United States); Popovic, M; Watson, P; Seuntjens, J [Montreal General Hospital, Medical Physics Unit, McGill University, Montreal, QC (Canada)

    2015-06-15

    Purpose: We investigated the effect of the EBT3 GafChromicTM film model absorbed dose energy response when used for percent depth dose (PDD) measurements in low-energy photon beams. Methods: We measured PDDs in water from a Xoft 50 kVp source using EBT3 film, and compared them to PDD measurements acquired with a PTW-TN34013 parallel-plate ionization chamber. For the x-ray source, we simulated spectra using the EGSnrc (BEAMnrc) Monte Carlo code, and calculated Half Value Layer (HVL) at different distances from the source in water. Pieces of EBT3 film were irradiated in air and calibration curves were created in terms of air-kerma in air ((Kair)air) for different beam qualities. Pieces of EBT3 film were positioned at distances of 2–6 cm from the Xoft source in a water phantom using a custom-made holder, and irradiated at the same time. As scatter is incorporated in the measured film signal in water, measured (Kair)wat was subsequently converted into absorbed dose to water by the ratio of mass energy absorption coefficients following the AAPM TG-61 dosimetry protocol. Results: Our results show that film calibration curves obtained at beam qualities near the effective energy of the Xoft 50 kVp source in water lead to variation in absorbed dose energy dependence of the response of around 3%. However, if the calibration curve was established at MV beam quality, the error in absorbed dose could be as large as 15%. We observed agreement within 1% between PDD measurements using EBT3 film model (using a calibration curve obtained at 80 kVp, HVL=2.18 mm Al, Eeff=29.5 keV) and the parallel-plate ionization chamber. Conclusion: Accurate dose measurements using radiochromic films at low photon energies require that the radiochromic film dosimetry system be calibrated at corresponding low energies, as large absorbed dose errors are expected for calibrations performed at MV beam qualities.

  19. Paddle-based rotating-shield brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunlong; Xu, Weiyu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung; Bhatia, Sudershan K.; Buatti, John M. [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center, Iowa City, Iowa 52242 (United States); Wu, Xiaodong, E-mail: xiaodong-wu@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2015-10-15

    Purpose: The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC), consisting of retractable paddles, to achieve intensity modulation in high-dose-rate brachytherapy. Methods: Five cervical cancer patients using an intrauterine tandem applicator were considered to assess the potential benefit of the P-RSBT method. The P-RSBT source used was a 50 kV electronic brachytherapy source (Xoft Axxent™). The paddles can be retracted independently to form multiple emission windows around the source for radiation delivery. The MLC was assumed to be rotatable. P-RSBT treatment plans were generated using the asymmetric dose–volume optimization with smoothness control method [Liu et al., Med. Phys. 41(11), 111709 (11pp.) (2014)] with a delivery time constraint, different paddle sizes, and different rotation strides. The number of treatment fractions (fx) was assumed to be five. As brachytherapy is delivered as a boost for cervical cancer, the dose distribution for each case includes the dose from external beam radiotherapy as well, which is 45 Gy in 25 fx. The high-risk clinical target volume (HR-CTV) doses were escalated until the minimum dose to the hottest 2 cm{sup 3} (D{sub 2cm{sup 3}}) of either the rectum, sigmoid colon, or bladder reached their tolerance doses of 75, 75, and 90 Gy{sub 3}, respectively, expressed as equivalent doses in 2 Gy fractions (EQD2 with α/β = 3 Gy). Results: P-RSBT outperformed the two other RSBT delivery techniques, single-shield RSBT (S-RSBT) and dynamic-shield RSBT (D-RSBT), with a properly selected paddle size. If the paddle size was angled at 60°, the average D{sub 90} increases for the delivery plans by P-RSBT on the five cases, compared to S-RSBT, were 2.2, 8.3, 12.6, 11.9, and 9.1 Gy{sub 10}, respectively, with delivery times of 10, 15, 20, 25, and 30 min/fx. The increases in HR-CTV D{sub 90}, compared to D-RSBT, were 16

  20. Intravascular brachytherapy for peripheral vascular disease

    Directory of Open Access Journals (Sweden)

    Hagen, Anja

    2008-09-01

    Full Text Available Scientific background: Percutaneous transluminal angioplasties (PTA through balloon dilatation with or without stenting, i.e. vessel expansion through balloons with or without of implantation of small tubes, called stents, are used in the treatment of peripheral artery occlusive disease (PAOD. The intravascular vessel irradiation, called intravascular brachytherapy, promises a reduction in the rate of repeated stenosis (rate of restenosis after PTA. Research questions: The evaluation addresses questions on medical efficacy, cost-effectiveness as well as ethic, social and legal implications in the use of brachytherapy in PAOD patients. Methods: A systematic literature search was conducted in August 2007 in the most important medical electronic databases for publications beginning from 2002. The medical evaluation included randomized controlled trials (RCT. The information synthesis was performed using meta-analysis. Health economic modeling was performed with clinical assumptions derived from the meta-analysis and economical assumptions derived from the German Diagnosis Related Groups (G-DRG-2007. Results: Medical evaluation: Twelve publications about seven RCT on brachytherapy vs. no brachytherapy were included in the medical evaluation. Two RCT showed a significant reduction in the rate of restenosis at six and/or twelve months for brachytherapy vs. no brachytherapy after successful balloon dilatation, the relative risk in the meta-analysis was 0.62 (95% CI: 0.46 to 0.84. At five years, time to recurrence of restenosis was significantly delayed after brachytherapy. One RCT showed a significant reduction in the rate of restenosis at six months for brachytherapy vs. no brachytherapy after PTA with optional stenting, the relative risk in the meta-analysis was 0.76 (95% CI: 0.61 to 0.95. One RCT observed a significantly higher rate of late thrombotic occlusions after brachytherapy in the subgroup of stented patients. A single RCT for brachytherapy

  1. On the question of 3D seed reconstruction in prostate brachytherapy: the determination of x-ray source and film locations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Mutian [Radiation Safety Office, Columbia University Medical Center, 722 West 168th Street, New York, NY 10032 (United States); Zaider, Marco [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Worman, Michael [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Cohen, Gilad [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States)

    2004-10-07

    Inaccuracy in seed placement during permanent prostate implants may lead to significant dosimetric deviations from the intended plan. In two recent publications (Todor et al 2002 Phys. Med. Biol. 47 2031-48, Todor et al 2003 Phys. Med. Biol. 48 1153-71), methodology was described for identifying intraoperatively the positions of seeds already implanted, thus allowing re-optimization of the treatment plan and correcting for such seed misplacement. Seed reconstruction is performed using fluoroscopic images and an important (and non-trivial) component of this approach is the ability to accurately determine the position of the gantry relative to the treatment volume. We describe the methodology for acquiring this information, based on the known geometry of six markers attached to the ultrasound probe. This method does not require the C-arm unit to be isocentric and films can be taken with the gantry set at any arbitrary position. This is significant because the patient positioning on the operating table (in the lithotomy position) restricts the range of angles at which films can be taken to a quite narrow (typically {+-}10{sup 0}) interval and, as a general rule, the closer the angles the larger the uncertainty in the seed location reconstruction along the direction from the x-ray source to the film. (note)

  2. Afterloading: The Technique That Rescued Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Aronowitz, Jesse N., E-mail: jesse.aronowitz@umassmemorial.org

    2015-07-01

    Although brachytherapy had been established as a highly effective modality for the treatment of cancer, its application was threatened by mid-20th century due to appreciation of the radiation hazard to health care workers. This review examines how the introduction of afterloading eliminated exposure and ushered in a brachytherapy renaissance.

  3. Study of dose calculation on breast brachytherapy using prism TPS

    Energy Technology Data Exchange (ETDEWEB)

    Fendriani, Yoza; Haryanto, Freddy [Nuclear Physics and Biophysics Research Division, FMIPA Institut Teknologi Bandung, Physics Buildings, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    PRISM is one of non-commercial Treatment Planning System (TPS) and is developed at the University of Washington. In Indonesia, many cancer hospitals use expensive commercial TPS. This study aims to investigate Prism TPS which been applied to the dose distribution of brachytherapy by taking into account the effect of source position and inhomogeneities. The results will be applicable for clinical Treatment Planning System. Dose calculation has been implemented for water phantom and CT scan images of breast cancer using point source and line source. This study used point source and line source and divided into two cases. On the first case, Ir-192 seed source is located at the center of treatment volume. On the second case, the source position is gradually changed. The dose calculation of every case performed on a homogeneous and inhomogeneous phantom with dimension 20 × 20 × 20 cm{sup 3}. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm{sup 3}. The results of dose calculations using PRISM TPS were compared to literature data. From the calculation of PRISM TPS, dose rates show good agreement with Plato TPS and other study as published by Ramdhani. No deviations greater than ±4% for all case. Dose calculation in inhomogeneous and homogenous cases show similar result. This results indicate that Prism TPS is good in dose calculation of brachytherapy but not sensitive for inhomogeneities. Thus, the dose calculation parameters developed in this study were found to be applicable for clinical treatment planning of brachytherapy.

  4. A Multi-Institutional Study of Feasibility, Implementation, and Early Clinical Results With Noninvasive Breast Brachytherapy for Tumor Bed Boost

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Subarna, E-mail: shamid@tuftsmedicalcenter.org [Department of Radiation Oncology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA (United States); Department of Radiation Oncology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI (United States); Rocchio, Kathy [Department of Radiation Oncology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI (United States); Arthur, Douglas; Vera, Robyn [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States); Sha, Sandra; Jolly, Michele [Central Florida Cancer Institute, Davenport, FL (United States); Cavanaugh, Sean; Wooten, Eric [Atlanta Oncology Associates, Hawkinsville, GA (United States); Benda, Rashmi; Greenfield, Brad [Department of Radiation Oncology, Boca Raton Community Hospital, Boca Raton, FL (United States); Prestidge, Bradley [Texas Cancer Clinic, San Antonio, TX (United States); Ackerman, Scot [First Coast Oncology, Jacksonville, FL (United States); Kuske, Robert; Quiet, Coral; Snyder, Margaret [Arizona Breast Cancer Specialists, Phoenix, AZ (United States); Wazer, David E. [Department of Radiation Oncology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA (United States); Department of Radiation Oncology, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI (United States)

    2012-08-01

    Purpose: To evaluate the feasibility, implementation, and early results of noninvasive breast brachytherapy (NIBB) for tumor bed boost with whole breast radiation therapy (WBRT). Methods and Materials: NIBB is a commercially available (AccuBoost, Billerica, MA) mammography-based, brachytherapy system in which the treatment applicators are centered on the planning target volume (PTV) to direct {sup 192}Ir emissions along orthogonal axes. A privacy-encrypted online data registry collected information from 8 independent academic and community-based institutions. Data were from 146 consecutive women with early-stage breast cancer after lumpectomy and WBRT receiving boost with NIBB between July 2007 and March 2010. Toxicity and cosmesis were graded according to the Common Toxicity Criteria (v. 3.0) and the Harvard scale. Median follow-up was 6 months (1-39 months). Results: Grade 1-2 skin toxicity was observed in 64%, 48%, and 21% during the acute (1-3 weeks), intermediate (4-26 weeks), and late-intermediate (>26 weeks) periods. There was no Grade 4 toxicity. At 6 months, for the entire cohort, cosmesis was excellent/good in 62%/38%. The subset receiving NIBB before WBRT had cosmetic scores of 32% and 63%, whereas during WBRT, 58% and 37% were rated as excellent and good, respectively. Breast compression was scored as 'uncomfortable' in 12%, 29%, and 59% when NIBB was delivered before, during, or after WBRT. For each patient, the fraction-to-fraction variability in PTV was low. Skin flash was associated with a higher proportion of excellent cosmesis (58% vs. 42%) relative to having the applicator all within breast tissue. Conclusions: These data indicate that NIBB is feasible and can be consistently implemented in a broad array of practice settings. Preliminary evaluation suggests that NIBB is associated with acceptably mild normal tissue toxicity and favorable early cosmesis. The application of NIBB before WBRT may be associated with better patient tolerance

  5. Interstitial rotating shield brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Quentin E., E-mail: quentin-adams@uiowa.edu; Xu, Jinghzu; Breitbach, Elizabeth K.; Li, Xing; Rockey, William R.; Kim, Yusung; Wu, Xiaodong; Flynn, Ryan T. [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Enger, Shirin A. [Medical Physics Unit, McGill University, 1650 Cedar Ave, Montreal, Quebec H3G 1A4 (Canada)

    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

  6. Extended (5-year) Outcomes of Accelerated Partial Breast Irradiation Using MammoSite Balloon Brachytherapy: Patterns of Failure, Patient Selection, and Dosimetric Correlates for Late Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Vargo, John A.; Verma, Vivek; Kim, Hayeon; Kalash, Ronny; Heron, Dwight E.; Johnson, Ronald; Beriwal, Sushil, E-mail: beriwals@upmc.edu

    2014-02-01

    Purpose: Accelerated partial breast irradiation (APBI) with balloon and catheter-based brachytherapy has gained increasing popularity in recent years and is the subject of ongoing phase III trials. Initial data suggest promising local control and cosmetic results in appropriately selected patients. Long-term data continue to evolve but are limited outside of the context of the American Society of Breast Surgeons Registry Trial. Methods and Materials: A retrospective review of 157 patients completing APBI after breast-conserving surgery and axillary staging via high-dose-rate {sup 192}Ir brachytherapy from June 2002 to December 2007 was made. APBI was delivered with a single-lumen MammoSite balloon-based applicator to a median dose of 34 Gy in 10 fractions over a 5-day period. Tumor coverage and critical organ dosimetry were retrospectively collected on the basis of computed tomography completed for conformance and symmetry. Results: At a median follow-up time of 5.5 years (range, 0-10.0 years), the 5-year and 7-year actuarial incidences of ipsilateral breast control were 98%/98%, of nodal control 99%/98%, and of distant control 99%/99%, respectively. The crude rate of ipsilateral breast recurrence was 2.5% (n=4); of nodal failure, 1.9% (n=3); and of distant failure, 0.6% (n=1). The 5-year and 7-year actuarial overall survival rates were 89%/86%, with breast cancer–specific survival of 100%/99%, respectively. Good to excellent cosmetic outcomes were achieved in 93.4% of patients. Telangiectasia developed in 27% of patients, with 1-year, 3-year, and 5-year actuarial incidence of 7%/24%/33%; skin dose >100% significantly predicted for the development of telangiectasia (50% vs 14%, P<.0001). Conclusions: Long-term single-institution outcomes suggest excellent tumor control, breast cosmesis, and minimal late toxicity. Skin toxicity is a function of skin dose, which may be ameliorated with dosimetric optimization afforded by newer multicatheter brachytherapy

  7. MO-D-BRD-03: Radiobiology and Commissioning of Electronic Brachytherapy for IORT

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. [Oregon Health & Science Univ (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  8. MO-D-BRD-01: Clinical Implementation of An Electronic Brachytherapy Program for the Skin

    Energy Technology Data Exchange (ETDEWEB)

    Ouhib, Z. [Lynn Regional Cancer Center (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  9. MO-D-BRD-02: Radiological Physics and Surface Lesion Treatments with Electronic Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fulkerson, R.

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  10. MO-D-BRD-04: NIST Air-Kerma Standard for Electronic Brachytherapy Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Mitch, M. [Nat’l Institute of Standards & Technology (United States)

    2015-06-15

    Electronic brachytherapy (eBT) has seen an insurgence of manufacturers entering the US market for use in radiation therapy. In addition to the established interstitial, intraluminary, and intracavitary applications of eBT, many centers are now using eBT to treat skin lesions. It is important for medical physicists working with electronic brachytherapy sources to understand the basic physics principles of the sources themselves as well as the variety of applications for which they are being used. The calibration of the sources is different from vendor to vendor and the traceability of calibrations has evolved as new sources came to market. In 2014, a new air-kerma based standard was introduced by the National Institute of Standards and Technology (NIST) to measure the output of an eBT source. Eventually commercial treatment planning systems should accommodate this new standard and provide NIST traceability to the end user. The calibration and commissioning of an eBT system is unique to its application and typically entails a list of procedural recommendations by the manufacturer. Commissioning measurements are performed using a variety of methods, some of which are modifications of existing AAPM Task Group protocols. A medical physicist should be familiar with the different AAPM Task Group recommendations for applicability to eBT and how to properly adapt them to their needs. In addition to the physical characteristics of an eBT source, the photon energy is substantially lower than from HDR Ir-192 sources. Consequently, tissue-specific dosimetry and radiobiological considerations are necessary when comparing these brachytherapy modalities and when making clinical decisions as a radiation therapy team. In this session, the physical characteristics and calibration methodologies of eBt sources will be presented as well as radiobiology considerations and other important clinical considerations. Learning Objectives: To understand the basic principles of electronic

  11. High-dose-rate brachytherapy with local injection of bleomycin for N0 oral tongue cancer. Possibilities of the control of tumor implant by inserting applicators and the decrease in tumor dose

    Energy Technology Data Exchange (ETDEWEB)

    Ohga, Saiji; Uehara, Satoru [National Kyushu Medical Center Hospital, Fukuoka (Japan); Miyoshi, Makoto [Kitakyushu Municipal Medical Center Hospital, Fukuoka (Japan); Jingu, Kenichi [Fukuoka Univ. (Japan). School of Medicine

    2003-01-01

    Twenty-eight patients with N0 oral tongue cancer were treated with high-dose-rate (HDR) interstitial brachytherapy combined with local injection of bleomycin between December 1997 and June 2001 at the Department of Radiology, National Kyushu Medical Center Hospital. A median dose of 5 mg of bleomycin was injected locally, and 16-20 Gy was delivered to the area surrounding applicators for control of the tumor implant during the initial two days. The two-year local recurrence-free survival rate was 96% [T1, 2: 100% (8/8, 15/15), T3: 80% (4/5)]. The two-year secondary neck node metastasis rate was 7.1% [T1: 12.5% (1/8), T2: 6.7% (1/15), T3: 0% (0/5)]. There were no tumor implants in any patients. We tried to decrease the minimal tumor dose step by step. The groups with median minimal tumor doses of 60 Gy, 50 Gy, and 40 Gy had local recurrence rates of 12.5% (1/8), 0% (0/14), and 0% (0/6), respectively. Local recurrence rates were not increased by decreasing the minimal tumor dose. Two patients (7%) had secondary neck node metastasis. Late adverse effects were tongue ulcer: 11% (3/28), oral floor ulcer: 4% (1/28), and osteonecrosis: 4% (1/28). These results suggest that control of the tumor implant and the decrease in minimal tumor dose below 60 Gy may be possible with the local injection of bleomycin and delivery of doses to the area surrounding the applicators when N0 tongue cancer is treated using {sup 192}Ir-HDR brachytherapy. (author)

  12. Study and development of methodology for radioactive iodine fixation in polymeric substrate for manufacturing sources used in brachytherapy; Estudo e desenvolvimento de metodologia para fixacao de iodo radioativo em substrato polimerico para confeccao de fontes utilizadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruna T.; Souza, Carla D.; Benega, Marcos A.G. and others, E-mail: bteigarodrigues@gmail.com, E-mail: carladdsouza@yahoo.com.br, E-mail: marcosagbenega@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes

    2014-07-01

    According global estimates of Globocan 2012 project of the International Agency for Research of Cancer, of the World Health Organization, there were 14,1 million new cases of cancer and a total of 8,2 million deaths from cancer. Also show that in 2030, the overall load will be 21,4 million new cases and 13,2 million cancer deaths. One of the prostate cancer therapy is brachytherapy, used in early and middle stages of the disease. It is made with the introduction of seeds with radioactive material within the tumor or in nearby regions, affecting the minimum surrounding tissues. The aim of this work is the study and developing the deposition of radioactive iodine on the polymeric substrate method, and an analysis relating the efficiency of the method to implementation in the laboratory of brachytherapy from IPEN. Iodine-125 is adsorbed on an epoxy resin solution. The objective of this study is to offer a new proposal for seeds. The results will give the data for the radiation protection and the procedures for radioactive waste management.

  13. Preliminary experience on the implementation of computed tomography (CT)-based image guided brachytherapy (IGBT) of cervical cancer using high-dose-rate (HDR) Cobalt-60 source in University of Malaya Medical Centre (UMMC)

    Science.gov (United States)

    Jamalludin, Z.; Min, U. N.; Ishak, W. Z. Wan; Malik, R. Abdul

    2016-03-01

    This study presents our preliminary work of the computed tomography (CT) image guided brachytherapy (IGBT) implementation on cervical cancer patients. We developed a protocol in which patients undergo two Magnetic Resonance Imaging (MRI) examinations; a) prior to external beam radiotherapy (EBRT) and b) prior to intra-cavitary brachytherapy for tumour identification and delineation during IGBT planning and dosimetry. For each fraction, patients were simulated using CT simulator and images were transferred to the treatment planning system. The HR-CTV, IR-CTV, bladder and rectum were delineated on CT-based contouring for cervical cancer. Plans were optimised to achieve HR-CTV and IR-CTV dose (D90) of total EQD2 80Gy and 60Gy respectively, while limiting the minimum dose to the most irradiated 2cm3 volume (D2cc) of bladder and rectum to total EQD2 90Gy and 75Gy respectively. Data from seven insertions were analysed by comparing the volume-based with traditional point- based doses. Based on our data, there were differences between volume and point doses of HR- CTV, bladder and rectum organs. As the number of patients having the CT-based IGBT increases from day to day in our centre, it is expected that the treatment and dosimetry accuracy will be improved with the implementation.

  14. Brachytherapy in breast cancer: an effective alternative

    Directory of Open Access Journals (Sweden)

    Janusz Skowronek

    2014-03-01

    Full Text Available Breast conserving surgery (BCS with following external beam radiation therapy (EBRT of the conserved breast has become widely accepted in the last decades for the treatment of early invasive breast cancer. The standard technique of EBRT after BCS is to treat the whole breast up to a total dose of 42.5 to 50 Gy. An additional dose is given to treated volume as a boost to a portion of the breast. In the early stage of breast cancer, research has shown that the area requiring radiation treatment to prevent the cancer from local recurrence is the breast tissue that surrounds the area where the initial cancer was removed. Accelerated partial breast irradiation (APBI is an approach that treats only the lumpectomy bed plus a 1-2 cm margin rather than the whole breast and as a result allows accelerated delivery of the radiation dose in four to five days. There has been a growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy (3D-EBRT and intra-operative radiation therapy (IORT. Balloon-based brachytherapy approaches include MammoSite, Axxent electronic brachytherapy, Contura, hybrid brachytherapy devices. Another indication for breast brachytherapy is reirradiation of local recurrence after mastectomy. Published results of brachytherapy are very promising. We discuss the current status, indications, and technical aspects of breast cancer brachytherapy.

  15. [Endobronchial brachytherapy: state of the art in 2013].

    Science.gov (United States)

    Derhem, N; Sabila, H; Mornex, F

    2013-04-01

    Endobronchial brachytherapy is an invasive technique, which allows localizing radioactive sources at the tumour contact. Therefore, high doses are administered to tumour while healthy tissues can be spared. Initially dedicated to a palliative setting, improvements helped reaching 60 to 88% symptoms alleviation and 30 to 100% of endoscopic macroscopic response. New diagnostic techniques and early diagnosis extended the indications to a curative intent: endoluminal primitive tumour, post radiation endobronchial recurrence, inoperable patients. CT-based dosimetry is a keypoint to optimize treatment quality and to minimize potential side effects, making this treatment a safe and efficient technique for specific indications.

  16. Brachytherapy for early oral tongue cancer: low dose rate to high dose rate.

    Science.gov (United States)

    Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Furukawa, Souhei; Kakimoto, Naoya; Shimizutani, Kimishige; Inoue, Toshihiko

    2003-03-01

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n = 341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer.

  17. Dose volume analysis in brachytherapy and stereotactic radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Tozer-Loft, S.M

    2000-12-01

    A brief introduction to three branches of radiotherapy is given: interstitial brachytherapy, external beam megavoltage radiotherapy, and stereotactic radiosurgery. The current interest in issues around conformity, uniformity and optimisation is explained in the light of technical developments in these fields. A novel method of displaying dose-volume information, which mathematically suppresses the inverse-square law, as first suggested by L.L. Anderson for use in brachytherapy is explained in detail, and some improvements proposed. These 'natural' histograms are extended to show the effects of real point sources which do not exactly follow the inverse-square law, and to demonstrate the in-target dose-volume distribution, previously unpublished. The histograms are used as a way of mathematically analysing the properties of theoretical mono-energetic radionuclides, and for demonstrating the dosimetric properties of a potential new brachytherapy source (Ytterbium-169). A new modification of the Anderson formalism is then described for producing Anderson Inverse-Square Shifted (AISS) histograms for the Gamma Knife, which are shown to be useful for demonstrating the quality of stereotactic radiosurgery dose distributions. A study is performed analysing the results of Gamma Knife treatments on 44 patients suffering from a benign brain tumour (acoustic neuroma). Follow-up data is used to estimate the volume shrinkage or growth of each tumour, and this measure of outcome is compared with a range of figures of merit which express different aspects of the quality of each dose distributions. The results are analysed in an attempt to answer the question: What are the important features of the dose distribution (conformality, uniformity, etc) which show a definite relationship with the outcome of the treatment? Initial results show positively that, when Gamma Knife radiosurgery is used to treat acoustic neuroma, some measures of conformality seem to have a surprising

  18. Value of diffusion weighted MR imaging as an early surrogate parameter for evaluation of tumor response to high-dose-rate brachytherapy of colorectal liver metastases

    Directory of Open Access Journals (Sweden)

    Röhl Friedrich-Wilhelm

    2011-04-01

    Full Text Available Abstract Background To assess the value of diffusion weighted imaging (DWI as an early surrogate parameter for treatment response of colorectal liver metastases to image-guided single-fraction 192Ir-high-dose-rate brachytherapy (HDR-BT. Methods Thirty patients with a total of 43 metastases underwent CT- or MRI-guided HDR-BT. In 13 of these patients a total of 15 additional lesions were identified, which were not treated at the initial session and served for comparison. Magnetic resonance imaging (MRI including breathhold echoplanar DWI sequences was performed prior to therapy (baseline MRI, 2 days after HDR-BT (early MRI as well as after 3 months (follow-up MRI. Tumor volume (TV and intratumoral apparent diffusion coefficient (ADC were measured independently by two radiologists. Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation. Results At early MRI no changes of TV and ADC were found for non-treated colorectal liver metastases. In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (p = 0.054 while mean tumor ADC decreased significantly by 11.4% (p p = 0.027 without significant change of mean ADC values. In contrast, mean TV of treated lesions decreased by 47.0% (p = 0.026 while the mean ADC increased inversely by 28.6% compared to baseline values (p Conclusions DWI is a promising imaging biomarker for early prediction of tumor response in patients with colorectal liver metastases treated with HDR-BT, yet the optimal interval between therapy and early follow-up needs to be elucidated.

  19. Methodology for commissioning a brachytherapy treatment planning system in the era of 3D planning.

    Science.gov (United States)

    Dempsey, Claire

    2010-12-01

    To describe the steps undertaken to commission a 3D high dose rate (HDR) brachytherapy treatment planning system (TPS). Emphasis was placed on validating previously published recommendations, in addition to checking 3D parameters such as treatment optimization and dose volume histogram (DVH) analysis. Commissioning was performed of the brachytherapy module of the Nucletron Oncentra MasterPlan treatment planning system (version 3.2). Commissioning test results were compared to an independent external beam TPS (Varian Eclipse v 8.6) and the previously commissioned Nucletron Plato (v 14.3.7) brachytherapy treatment planning system, with point doses also independently verified using the brachytherapy module in RadCalc (v 6.0) independent point dose calculation software. Tests were divided into eight categories: (i) Image import accuracy, (ii) Reconstruction accuracy, (iii) Source configuration data check, (iv) Dose calculation accuracy, (v) Treatment optimization validation, (vi) DVH reproducibility, (vii) Treatment export check and (viii) Printout consistency. Point dose agreement between Oncentra, Plato and RadCalc was better than 5% with source data and dose calculation protocols following the American Association of Physicists in Medicine (AAPM) guidelines. Testing of image accuracy (import and reconstruction), along with validation of automated treatment optimization and DVH analysis generated a more comprehensive set of testing procedures than previously listed in published recommendations.

  20. Tandem-ring dwell time ratio in Nigeria: dose comparisons of two loading patterns in standard high-dose-rate brachytherapy planning for cervical cancer

    OpenAIRE

    2015-01-01

    Purpose In high-dose-rate (HDR) brachytherapy (BT), the source dwell times and dwell positions are essential treatment planning parameters. An optimal choice of these factors is fundamental to obtain the desired target coverage with the lowest achievable dose to the organs at risk (OARs). This study evaluates relevant dose parameters in cervix brachytherapy in order to assess existing tandem-ring dwell time ratio used at the first HDR BT center in Nigeria, and compare it with an alternative s...

  1. Brachytherapy dose measurements in heterogeneous tissues

    Energy Technology Data Exchange (ETDEWEB)

    Paiva F, G.; Luvizotto, J.; Salles C, T.; Guimaraes A, P. C.; Dalledone S, P. de T.; Yoriyaz, H. [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Rubo, R., E-mail: gabrielpaivafonseca@gmail.com [Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, 05403-900 Sao Paulo (Brazil)

    2014-08-15

    Recently, Beau lieu et al. published an article providing guidance for Model-Based Dose Calculation Algorithms (MBDCAs), where tissue heterogeneity considerations are addressed. It is well-known that T G-43 formalism which considers only water medium is limited and significant dose differences have been found comparing both methodologies. The aim of the present work is to experimentally quantify dose values in heterogeneous medium using different dose measurement methods and techniques and compare them with those obtained with Monte Carlo simulations. Experiments have been performed using a Nucletron micro Selectron-Hdr Ir-192 brachytherapy source and a heterogeneous phantom composed by PMMA and different tissue equivalent cylinders like bone, lungs and muscle. Several dose measurements were obtained using tissue equivalent materials with height 1.8 cm and 4.3 cm positioned between the radiation source and the detectors. Radiochromic films, TLDs and MOSFET S have been used for the dose measurements. Film dosimetry has been performed using two methodologies: a) linearization for dose-response curve based on calibration curves to create a functional form that linearize s the dose response and b) 177 multichannel analysis dosimetry where the multiple color channels are analyzed allowing to address not only disturbances in the measurements caused by thickness variation in the film layer, but also, separate other external influences in the film response. All experiments have been simulated using the MCNP5 Monte Carlo radiation transport code. Comparison of experimental results are in good agreement with calculated dose values with differences less than 6% for almost all cases. (Author)

  2. On the Development of a Miniature Neutron Generator for the Brachytherapy Treatment of Cancer

    Science.gov (United States)

    Forman, L.

    2009-03-01

    Brachytherapy refers to application of an irradiation source within a tumor. 252Cf needles used in brachytherapy have been successfully applied to treatment of some of the most virulent cancers but it is doubtful that it will be widely used because of difficulty in dealing with unwanted dose (source cannot be turned off) and in adhering to stringent NRC regulations that have been exacerbated in our post 911 environment. We have been working on the development of a miniature neutron generator with the reaction target placed at the end of a needle (tube) for brachytherapy applications. Orifice geometries are most amenable, e.g. rectum and cervix, but interstitial use is possible with microsurgery. This paper dicusses the results of a 30 watt DD neutron generator SBU project that demonstrates that sufficient hydrogen isotope current can be delivered down a small diameter needle required for a DT neutron treatment device, and, will summarize the progress of building a commercial device pursued by the All Russian Institute for Automatics (VNIIA) supported by the DOE's Industrial Proliferation Prevention Program (IPP). It is known that most of the fast neutron (FN) beam cancer treatment facilities have been closed down. It appears that the major limitation in the use of FN beams has been damage to healthy tissue, which is relatively insensitive to photons, but this problem is alleviated by brachytherapy. Moreover, recent clinical results indicate that fast neutrons in the boost mode are most highly effective in treating large, hypoxic, and rapidly repopulating diseases. It appears that early boost application of FN may halt angiogenesis (development and repair of tumor vascular system) and shrink the tumor resulting in lower hypoxia. The boost brachytherapy application of a small, low cost neutron generator holds promise of significant contribution to the treatment of cancer.

  3. High dose rate interstitial brachytherapy in soft tissue sarcomas: technical aspect

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Mi Son; Kang, Seung Hee; Kim, Byoung Suck; Oh, Young Taek [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    1999-03-01

    To discuss the technical aspect of interstitial brachytherapy including method of implant, insertion time of radioactive source, total radiation dose, and complication, we reviewed patients who had diagnoses of soft tissue sarcoma and were treated by conservative surgery, interstitial implant and external beam radiation therapy. Between May 1995 and Dec. 1997, the patients with primary or recurrent soft tissue sarcoma underwent surgical resection (wide margin excision) and received radiotherapy including interstitial brachytherapy. Catheters were placed with regular intervals of 1-1.5 cm immediately after tumor removal and covering the critical structures, such as neurovascular bundle or bone, with gelform, muscle, or tissue expander in the cases where the tumors were close to those structures. Brachytherapy consisted of source axis with 2-2.5 Gy/fraction, twice a day, starting on 6th day after the surgery. Within one month after the surgery, total dose of 50-55 Gy was delivered to the tumor bed with wide margin by the external beam radiotherapy. All patients completed planned interstitial brachytherapy without acute side effects directly related with catheter implantation such as infection or bleeding. With median follow up duration of 25 months (range 12-41 months), no local recurrences were observed. And there was no severe form of chromic complication (RTOG/EORTC grade 3 or 4). The high dose rate interstitial brachytherapy is easy and safe way to minimize the radiation dose delivered to the adjacent normal tissue and to decrease radiation induced chronic morbidity such as fibrosis by reducing the total dose of external radiotherapy in the management of soft tissue sarcoma with conservative surgery.

  4. Brachytherapy Application With In Situ Dose Painting Administered by Gold Nanoparticle Eluters

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Neeharika [Department of Sciences, Wentworth Institute of Technology, Boston, Massachusetts (United States); Cifter, Gizem [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Sajo, Erno [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Kumar, Rajiv; Sridhar, Srinivas [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Electronic Materials Research Institute and Department of Physics, Northeastern University, Boston, Massachusetts (United States); Nguyen, Paul L.; Cormack, Robert A.; Makrigiorgos, G. Mike [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Ngwa, Wilfred, E-mail: wngwa@lroc.harvard.edu [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    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

  5. Calculating of Dose Distribution in Tongue Brachytherapy by Different Radioisotopes using Monte Carlo Simulation and Comparing by Experimental Data

    Directory of Open Access Journals (Sweden)

    Banafsheh Zeinali Rafsanjani

    2011-06-01

    Full Text Available Introduction: Among different kinds of oral cavity cancers, the frequency of tongue cancer occurrence is more significant. Brachytherapy is the most common method to cure tongue cancers. Long sources are used in different techniques of tongue brachytherapy. The objective of this study is to asses the dose distribution around long sources, comparing different radioisotopes as brachytherapy sources, measuring the homogeneity of delivered dose to treatment volume and also comparing mandible dose and dose of tongue in the regions near the mandible with and without using shield. Material and Method: The Monte Carlo code MCNP4C was used for simulation. The accuracy of simulation was verified by comparing the results with experimental data. The sources like Ir-192, Cs-137, Ra-226, Au-198, In-111 and Ba-131 were simulated and the position of sources was determined by Paris system. Results: The percentage of mandible dose reduction with use of 2 mm Pb shield for the sources mentioned above were: 35.4%, 20.1%, 86.6%, 32.24%, 75.6%, and 36.8%. The tongue dose near the mandible with use of shied did not change significantly. The dose homogeneity from the most to least was obtained from these sources: Cs-137, Au-198, Ir-192, Ba-131, In-111 and Ra-226. Discussion and Conclusion: Ir-192 and Cs-137 were the best sources for tongue brachytherapy treatment but In-111 and Ra-226 were not suitable choices for tongue brachytherapy. The sources like Au-198 and Ba-131 had rather the same performance as Ir-192

  6. Interstitial hyperthermia in combination with brachytherapy.

    Science.gov (United States)

    Coughlin, C T; Douple, E B; Strohbehn, J W; Eaton, W L; Trembly, B S; Wong, T Z

    1983-07-01

    Flexible coaxial cables were modified to serve as microwave antennas operating at a frequency of 915 MHz. These antennas were inserted into nylon afterloading tubes that had been implanted in tumors using conventional interstitial implantation techniques for iridium-192 seed brachytherapy. The tumor volume was heated to 42-45 degrees C within 15 minutes and heating was continued for a total of 1 hour per treatment. Immediately following a conventional brachytherapy dose and removal of the iridium seeds the tumors were heated again in a second treatment. This interstitial technique for delivering local hyperthermia should be compatible with most brachytherapy methods. The technique has proved so far to be practical and without complications. Temperature distributions obtained in tissue phantoms and a patient are described.

  7. High dose rate versus low dose rate brachytherapy for oral cancer--a meta-analysis of clinical trials.

    Directory of Open Access Journals (Sweden)

    Zhenxing Liu

    Full Text Available OBJECTIVE: To compare the efficacy and safety of high dose rate (HDR and low dose rate (LDR brachytherapy in treating early-stage oral cancer. DATA SOURCES: A systematic search of MEDLINE, EMBASE and Cochrane Library databases, restricted to English language up to June 1, 2012, was performed to identify potentially relevant studies. STUDY SELECTION: Only randomized controlled trials (RCT and controlled trials that compared HDR to LDR brachytherapy in treatment of early-stage oral cancer (stages I, II and III were of interest. DATA EXTRACTION AND SYNTHESIS: Two investigators independently extracted data from retrieved studies and controversies were solved by discussion. Meta-analysis was performed using RevMan 5.1. One RCT and five controlled trials (607 patients: 447 for LDR and 160 for HDR met the inclusion criteria. The odds ratio showed no statistically significant difference between LDR group and HDR group in terms of local recurrence (OR = 1.12, CI 95% 0.62-2.01, overall mortality (OR = 1.01, CI 95% 0.61-1.66 and Grade 3/4 complications (OR = 0.86, CI 95% 0.52-1.42. CONCLUSIONS: This meta-analysis indicated that HDR brachytherapy was a comparable alternative to LDR brachytherapy in treatment of oral cancer. HDR brachytherapy might become a routine choice for early-stage oral cancer in the future.

  8. Applicator Attenuation Effect on Dose Calculations of Esophageal High-Dose Rate Brachytherapy Using EDR2 Film

    Directory of Open Access Journals (Sweden)

    Seyed Mohsen Hosseini Daghigh

    2012-03-01

    Full Text Available Introduction Interaluminal brachytherapy is one of the important methods of esophageal cancer treatment. The effect of applicator attenuation is not considered in dose calculation method released by AAPM-TG43. In this study, the effect of High-Dose Rate (HDR brachytherapy esophageal applicator on dose distribution was surveyed in HDR brachytherapy. Materials and Methods A cylindrical PMMA phantom was built in order to be inserted by various sizes of esophageal applicators. EDR2 films were placed at 33 mm from Ir-192 source and irradiated with 1.5 Gy after planning using treatment planning system for all applicators. Results The results of film dosimetry in reference point for 6, 8, 10, and 20 mm applicators were 1.54, 1.53, 1.48, and 1.50 Gy, respectively. The difference between practical and treatment planning system results was 0.023 Gy (

  9. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

    Science.gov (United States)

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-03-01

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  10. Dosimetric optimization of a conical breast brachytherapy applicator for improved skin dose sparing

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yun; Rivard, Mark J. [Biomedical Engineering and Biotechnology, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2010-11-15

    Purpose: Both the AccuBoost D-shaped and round applicators have been dosimetrically characterized and clinically used to treat patients with breast cancer. While the round applicators provide conformal dose coverage, under certain clinical circumstances the breast skin dose may be higher than preferred. The purpose of this study was to modify the round applicators to minimize skin dose while not substantially affecting dose uniformity within the target volume and reducing the treatment time. Methods: In order to irradiate the intended volume while sparing critical structures such as the skin, the current round applicator design has been augmented through the addition of an internal truncated cone (i.e., frustum) shield. Monte Carlo methods and clinical constraints were used to design the optimal cone applicator. With the cone applicator now defined as the entire assembly including the surrounding tungsten-alloy shell holding the HDR {sup 192}Ir source catheter, the applicator height was reduced to diminish the treatment time while minimizing skin dose. Monte Carlo simulation results were validated using both radiochromic film and ionization chamber measurements based on established techniques. Results: The optimal cone applicators diminished the maximum skin dose by 15%-32% (based on the applicator diameter and breast separation) with the tumor dose reduced by less than 3% for a constant exposure time. Furthermore, reduction in applicator height diminished the treatment time by up to 30%. Radiochromic film and ionization chamber dosimetric results in phantom agreed with Monte Carlo simulation results typically within 3%. Larger differences were outside the treatment volume in low dose regions or associated with differences between the measurement and Monte Carlo simulation environments. Conclusions: A new radiotherapy treatment device was developed and dosimetrically characterized. This set of applicators significantly reduces the skin dose and treatment time while

  11. Study and parameters survey for iodine-125 source dosimetry to be applied in brachytherapy; Estudo e levantamentos de parametros para dosimetria de fontes de iodo-125 aplicadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo Santana de

    2011-07-01

    The use of brachytherapy technique with iodine-125 seeds to prostate cancer treatment has been used for decades with good clinical outcomes. To aim the Brazilian population necessities, IPEN-CNEN/SP developed the iodine-125 seed prototype with national technology. The objectives of this work are the development and the study of dosimetric procedures associates with the experimental acquisition of the useful parameters for the iodine-125 dosimetric characterization and to evaluate if the developed procedures, in this work, have the basic conditions to determinate the dosimetric analysis, that are fundamental for clinical procedures. The dosimeters selected for the analysis are the TLD-100 (LiF:Mg,Ti), initially these dosimeters were submitted for two selection steps to choose the dosimeters more reproducible for the dosimetric analysis. The two steps were the selection by the mass of the dosimeters and the reproducibility after four irradiation series in a Cobalt-60 irradiator (CTR-IPEN). Afterwards these steps, the dosimeters were irradiated in linear accelerator with 6 MV energy (Service of Radiotherapy - Hospital Israelita Albert Einstein) to yield the individual calibration factors to each dosimeter. After, the dosimeters were used to the irradiations with iodine-125 seed, 6711 model, (GE-Healthcare). The irradiations and others analysis with iodine-125 seeds yield the useful values for the determination of the parameters suggested by the AAPM (American Association of Physicists in Medicine): constant of dose rate, geometry function, dose radial function and anisotropy function. The results showed good agreement with the values published by the literature, for the same iodine- 125 model, this fact confirms that the realized parameters will be able to be used for the IPEN-CNEN iodine-125 seeds dosimetry and quality control. (author)

  12. CT-based interstitial HDR brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kolotas, C.; Baltas, D.; Zamboglou, N. [Staedtische Kliniken Offenbach (Germany). Strahlenklinik

    1999-09-01

    Purpose: Development, application and evaluation of a CT-guided implantation technique and a fully CT-based treatment planning procedure for brachytherapy. Methods and Materials: A brachytherapy procedure based on CT-guided implantation technique and CT-based treatment planning has been developed and clinical evaluated. For this purpose a software system (PROMETHEUS) for the 3D reconstruction of brachytherapy catheters and patient anatomy using only CT scans has been developed. An interface for the Nucletron PLATO BPS treatment planning system for optimization and calculation of dose distribution has been devised. The planning target volume(s) are defined as sets of points using contouring tools and are used for optimization of the 3D dose distribution. Dose-volume histogram based analysis of the dose distribution (COIN analysis) enables a clinically realistic evaluation of the brachytherapy application to be made. The CT-guided implantation of catheters and the CT-based treatment planning procedure has been performed for interstitial brachytherapy and for different tumor sites in 197 patients between 1996 and 1997. Results: The accuracy of the CT reconstruction was tested using first a quality assurance phantom and second, a simulated interstitial implant of 12 needles. These were compared with the results of reconstruction using radiographs. Both methods gave comparable results with regard to accuracy, but the CT based reconstruction was faster. Clinical feasibility was proved in pre-irradiated recurrences of brain tumors, in pretreated recurrences or metastatic disease, and in breast carcinomas. The tumor volumes treated were in the range 5.1 to 2,741 cm{sup 3}. Analysis of implant quality showed a slightly significant lower COIN value for the bone implants, but no differences with respect to the planning target volume. Conclusions: The Offenbach system, incorporating the PROMETHEUS software for interstitial HDR brachytherapy has proved to be extremely valuable

  13. Portfolio of prospective clinical trials including brachytherapy: an analysis of the ClinicalTrials.gov database

    OpenAIRE

    Cihoric, Nikola; Tsikkinis, Alexandros; Miguelez, Cristina Gutierrez; Strnad, Vratislav; Soldatovic, Ivan; Ghadjar, Pirus; Jeremic, Branislav; Dal Pra, Alan; Aebersold, Daniel M; Lössl, Kristina

    2016-01-01

    Background To evaluate the current status of prospective interventional clinical trials that includes brachytherapy (BT) procedures. Methods The records of 175,538 (100 %) clinical trials registered at ClinicalTrials.gov were downloaded on September 2014 and a database was established. Trials using BT as an intervention were identified for further analyses. The selected trials were manually categorized according to indication(s), BT source, applied dose rate, primary sponsor type, location, p...

  14. Portfolio of prospective clinical trials including brachytherapy: an analysis of the ClinicalTrials.gov database

    OpenAIRE

    Cihoric, Nikola; Tsikkinis, Alexandros; Gutierrez Miguelez, Cristina; Strnad, Vratislav; Soldatovic, Ivan; Ghadjar, Pirus; Jeremic, Branislav; Dal Pra, Alan; Aebersold, Daniel M; Lössl, Kristina

    2016-01-01

    Background To evaluate the current status of prospective interventional clinical trials that includes brachytherapy (BT) procedures. Methods The records of 175,538 (100 %) clinical trials registered at ClinicalTrials.gov were downloaded on September 2014 and a database was established. Trials using BT as an intervention were identified for further analyses. The selected trials were manually categorized according to indication(s), BT source, applied dose rate, primary sponsor type,...

  15. Automated intraoperative calibration for prostate cancer brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kuiran Chen, Thomas; Heffter, Tamas; Lasso, Andras; Pinter, Csaba; Abolmaesumi, Purang; Burdette, E. Clif; Fichtinger, Gabor [Queen' s University, Kingston, Ontario K7L 3N6 (Canada); University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Acoustic MedSystems, Inc., Champaign, Illinois 61820-3979 (United States); Queen' s University, Kingston, Ontario K7L 3N6 (Canada) and Johns Hopkins University, Baltimore, Maryland 21218-2682 (United States)

    2011-11-15

    Purpose: Prostate cancer brachytherapy relies on an accurate spatial registration between the implant needles and the TRUS image, called ''calibration''. The authors propose a new device and a fast, automatic method to calibrate the brachytherapy system in the operating room, with instant error feedback. Methods: A device was CAD-designed and precision-engineered, which mechanically couples a calibration phantom with an exact replica of the standard brachytherapy template. From real-time TRUS images acquired from the calibration device and processed by the calibration system, the coordinate transformation between the brachytherapy template and the TRUS images was computed automatically. The system instantly generated a report of the target reconstruction accuracy based on the current calibration outcome. Results: Four types of validation tests were conducted. First, 50 independent, real-time calibration trials yielded an average of 0.57 {+-} 0.13 mm line reconstruction error (LRE) relative to ground truth. Second, the averaged LRE was 0.37 {+-} 0.25 mm relative to ground truth in tests with six different commercial TRUS scanners operating at similar imaging settings. Furthermore, testing with five different commercial stepper systems yielded an average of 0.29 {+-} 0.16 mm LRE relative to ground truth. Finally, the system achieved an average of 0.56 {+-} 0.27 mm target registration error (TRE) relative to ground truth in needle insertion tests through the template in a water tank. Conclusions: The proposed automatic, intraoperative calibration system for prostate cancer brachytherapy has achieved high accuracy, precision, and robustness.

  16. Study and methodology development for quality control in the production process of iodine-125 radioactive sealed sources applied to brachytherapy; Estudo e desenvolvimento de metodologia para controle de qualidade em processo de producao de fontes seladas de iodo-125 para aplicacao em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Joao Augusto

    2009-07-01

    Today cancer is the second cause of death by disease in several countries, including Brazil. Excluding skin cancer, prostate cancer is the most incident in the population. Prostate tumor can be treated by several ways, including brachytherapy, which consists in introducing sealed radioactive sources (Iodine - 125 seeds) inside the tumor. The target region of treatment receives a high radiation dose, but healthy neighbor tissues receive a significantly reduced radiation dose. The seed is made of a welding sealed titanium capsule, 0.8 mm external diameter and 4.5 mm length, enclosing a 0.5 mm diameter silver wire with Iodine-125 adsorbed. After welded, the seeds have to be submitted to a leak test to prevent any radioactive material release. The aims of this work were: (a) the study of the different leakage test methods applied to radioactive seeds and recommended by the ISO 997820, (b) the choice of the appropriate method and (c) the flowchart determination of the process to be used during the seeds production. The essays exceeded the standards with the use of ultra-sound during immersion and the corresponding benefits to leakage detection. Best results were obtained with the immersion in distilled water at 20 degree C for 24 hours and distilled water at 70 degree C for 30 minutes. These methods will be used during seed production. The process flowchart has all the phases of the leakage tests according to the sequence determined in the experiments. (author)

  17. Prostate cancer brachytherapy; Braquiterapia de cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Carlos Eduardo Vita; Silva, Joao L. F. [Hospital Sirio Libanes, Sao Paulo, SP (Brazil). Centro de Oncologia. Dep. de Radioterapia; Srougi, Miguel; Nesrallah, Adriano [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina (EPM). Disciplina de Urologia]. E-mail: cevitabr@mandic.com.br

    1999-07-01

    The transperineal brachytherapy with {sup 125}I/Pd{sup 103} seed implantation guided by transurethral ultrasound must be presented as therapeutical option of low urinary morbidity in patients with localized prostate cancer. The combined clinical staging - including Gleason and initial PSA - must be encouraged, for definition of a group of low risk and indication of exclusive brachytherapy. Random prospective studies are necessary in order to define the best role of brachytherapy, surgery and external beam radiation therapy.

  18. Verification of the calculation program for brachytherapy planning system of high dose rate (PLATO); Programa de verificacion del calculo para un sistema de planificacion de braquiterapia de alta tasa de dosis (PLATO)

    Energy Technology Data Exchange (ETDEWEB)

    Almansa, J.; Alaman, C.; Perez-Alija, J.; Herrero, C.; Real, R. del; Ososrio, J. L.

    2011-07-01

    In our treatments are performed brachytherapy high dose rate since 2007. The procedures performed include gynecological intracavitary treatment and interstitial. The treatments are performed with a source of Ir-192 activity between 5 and 10 Ci such that small variations in treatment times can cause damage to the patient. In addition the Royal Decree 1566/1998 on Quality Criteria in radiotherapy establishes the need to verify the monitor units or treatment time in radiotherapy and brachytherapy. All this justifies the existence of a redundant system for brachytherapy dose calculation that can reveal any abnormality is present.

  19. State-of-the-art: prostate LDR brachytherapy.

    Science.gov (United States)

    Voulgaris, S; Nobes, J P; Laing, R W; Langley, S E M

    2008-01-01

    This article on low dose rate (LDR) prostate brachytherapy reviews long-term results, patient selection and quality of life issues. Mature results from the United States and United Kingdom are reported and issues regarding definitions of biochemical failure are discussed. Latest data comparing brachytherapy with radical prostatectomy or no definitive treatment and also the risk of secondary malignancies after prostate brachytherapy are presented. Urological parameters of patient selection and quality of life issues concerning urinary, sexual and bowel function are reviewed. The position of prostate brachytherapy next to surgery as a first-line treatment modality is demonstrated.

  20. Plastic optical fibre sensor for in-vivo radiation monitoring during brachytherapy

    Science.gov (United States)

    Woulfe, P.; Sullivan, F. J.; Lewis, E.; O'Keeffe, S.

    2015-09-01

    An optical fibre sensor is presented for applications in real-time in-vivo monitoring of the radiation dose a cancer patient receives during seed implantation in Brachytherapy. The sensor is based on radioluminescence whereby radiation sensitive scintillation material is embedded in the core of a 1mm plastic optical fibre. Three scintillation materials are investigated: thallium-doped caesium iodide (CsI:Tl), terbium-doped gadolinium oxysulphide (Gd2O2S:Tb) and europium-doped lanthanum oxysulphide (La2O2S:Eu). Terbium-doped gadolinium oxysulphide was identified as being the most suitable scintillator and further testing demonstrates its measureable response to different activities of Iodine-125, the radio-active source commonly used in Brachytherapy for treating prostate cancer.

  1. EVALUATION OF BRACHYTHERAPY FACILITY SHIELDING STATUS IN KOREA OBTAINED FROM RADIATION SAFETY REPORTS

    Directory of Open Access Journals (Sweden)

    MI HYUN KEUM

    2013-10-01

    Full Text Available Thirty-eight radiation safety reports for brachytherapy equipment were evaluated to determine the current status of brachytherapy units in Korea and to assess how radiation oncology departments in Korea complete radiation safety reports. The following data was collected: radiation safety report publication year, brachytherapy unit manufacturer, type and activity of the source that was used, affiliation of the drafter, exposure rate constant, the treatment time used to calculate workload and the HVL values used to calculate shielding design goal values. A significant number of the reports (47.4% included the personal information of the drafter. The treatment time estimates varied widely from 12 to 2,400 min/week. There was acceptable variation in the exposure rate constant values (ranging between 0.469 and 0.592 (R-m2/Ci·hr, as well as in the HVLs of concrete, steel and lead for Iridium-192 sources that were used to calculate shielding design goal values. There is a need for standard guidelines for completing radiation safety reports that realistically reflect the current clinical situation of radiation oncology departments in Korea. The present study may be useful for formulating these guidelines.

  2. Tissue modeling schemes in low energy breast brachytherapy.

    Science.gov (United States)

    Afsharpour, Hossein; Landry, Guillaume; Reniers, Brigitte; Pignol, Jean-Philippe; Beaulieu, Luc; Verhaegen, Frank

    2011-11-21

    Breast tissue is heterogeneous and is mainly composed of glandular (G) and adipose (A) tissues. The proportion of G versus A varies considerably among the population. The absorbed dose distributions in accelerated partial breast irradiation therapy with low energy photon brachytherapy sources are very sensitive to tissue heterogeneities. Current clinical algorithms use the recommendations of the AAPM TG43 report which approximates the human tissues by unit density water. The aim of this study is to investigate various breast tissue modeling schemes for low energy brachytherapy. A special case of breast permanent seed implant is considered here. Six modeling schemes are considered. Uniform and non-uniform water breast (UWB and NUWB) consider the density but neglect the effect of the composition of tissues. The uniform and the non-uniform G/A breast (UGAB and NUGAB) as well the age-dependent breast (ADB) models consider the effect of the composition. The segmented breast tissue (SBT) method uses a density threshold to distinguish between G and A tissues. The PTV D(90) metric is used for the analysis and is based on the dose to water (D(90(w,m))). D(90(m,m)) is also reported for comparison to D(90(w,m)). The two-month post-implant D(90(w,m)) averaged over 38 patients is smaller in NUWB than in UWB by about 4.6% on average (ranging from 5% to 13%). Large average differences of G/A breast models with TG43 (17% and 26% in UGAB and NUGAB, respectively) show that the effect of the chemical composition dominates the effect of the density on dose distributions. D(90(w,m)) is 12% larger in SBT than in TG43 when averaged. These differences can be as low as 4% or as high as 20% when the individual patients are considered. The high sensitivity of dosimetry on the modeling scheme argues in favor of an agreement on a standard tissue modeling approach to be used in low energy breast brachytherapy. SBT appears to generate the most geometrically reliable breast tissue models in this

  3. The Preliminary Prototype of Medium Dose Rate Brachytherapy Equipment

    Directory of Open Access Journals (Sweden)

    A. Satmoko

    2013-08-01

    Full Text Available A preliminary prototype of a brachytherapy equipment has been constructed. The work started by developing conceptual design, followed by basic design and detailed design. In the conceptual design, design requirements are stated. In the basic design, technical specifications for main components are determined. In detailed design, general drawings are discussed. The prototype consists of three main systems: a mechanical system, an instrumentation system, and a safety system. The mechanical system assures the movement mechanism of the isotope source position beginning from the standby position until the applicators. It consists of three main modules: a position handling module, a container module, and a channel distribution module. The position handling module serves to move the isotope source position. As shielding, the second module is to store the source when the equipment is in standby position. The prototype provides 12 output channels. The channel selection is performed by the third module. The instrumentation system controls the movement of source position by handling motor operations. It consists of several modules. A microcontroller module serves as a control center whose task includes both controlling motors and communicating with computer. A motor module serves to handle motors. 10 sensors, including their signal conditionings, are introduced to read the environment conditions of the equipment. LEDs are used to display these conditions. In order to facilitate the operators’ duty, communication via RS232 is provided. The brachytherapy equipment can therefore be operated by using computer. Interface software is developed using C# language. To complete both mechanical and instrumentation systems performance, a safety system is developed to make sure that the safety for operator and patients from receiving excessive radiation. An interlock system is introduced to guard against abnormal conditions. In the worst case, a manual intervention

  4. CT-Based Brachytherapy Treatment Planning using Monte Carlo Simulation Aided by an Interface Software

    Directory of Open Access Journals (Sweden)

    Vahid Moslemi

    2011-03-01

    Full Text Available Introduction: In brachytherapy, radioactive sources are placed close to the tumor, therefore, small changes in their positions can cause large changes in the dose distribution. This emphasizes the need for computerized treatment planning. The usual method for treatment planning of cervix brachytherapy uses conventional radiographs in the Manchester system. Nowadays, because of their advantages in locating the source positions and the surrounding tissues, CT and MRI images are replacing conventional radiographs. In this study, we used CT images in Monte Carlo based dose calculation for brachytherapy treatment planning, using an interface software to create the geometry file required in the MCNP code. The aim of using the interface software is to facilitate and speed up the geometry set-up for simulations based on the patient’s anatomy. This paper examines the feasibility of this method in cervix brachytherapy and assesses its accuracy and speed. Material and Methods: For dosimetric measurements regarding the treatment plan, a pelvic phantom was made from polyethylene in which the treatment applicators could be placed. For simulations using CT images, the phantom was scanned at 120 kVp. Using an interface software written in MATLAB, the CT images were converted into MCNP input file and the simulation was then performed. Results: Using the interface software, preparation time for the simulations of the applicator and surrounding structures was approximately 3 minutes; the corresponding time needed in the conventional MCNP geometry entry being approximately 1 hour. The discrepancy in the simulated and measured doses to point A was 1.7% of the prescribed dose.  The corresponding dose differences between the two methods in rectum and bladder were 3.0% and 3.7% of the prescribed dose, respectively. Comparing the results of simulation using the interface software with those of simulation using the standard MCNP geometry entry showed a less than 1

  5. Brachytherapy for the treatment of prostate cancer.

    Science.gov (United States)

    Cesaretti, Jamie A; Stone, Nelson N; Skouteris, Vassilios M; Park, Janelle L; Stock, Richard G

    2007-01-01

    Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. Largely due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. The reason that brachytherapy results are reproducible in several different practice settings is because numerous implant quality factors have been defined over the last 20 years, which can be applied objectively to judge the success of the intervention both during and after the procedure. In addition, recent long-term follow-up studies have clarified that the secondary cancer incidence of brachytherapy is not clinically meaningful. In terms of future directions, the study of radiation repair genetics may allow for the counseling physician to better estimate any given patients risk for side effects, thereby substantially reducing the therapeutic uncertainties faced by patients choosing a prostate cancer intervention.

  6. A fibre optic dosimeter customised for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Suchowerska, N. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia)], E-mail: Natalka@email.cs.nsw.gov.au; Lambert, J.; Nakano, T. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia); Law, S. [School of Physics, University of Sydney, NSW 2006 (Australia); Optical Fibre Technology Centre, University of Sydney, 206 National Innovation Centre, Australian Technology Park, Eveleigh, NSW 1430 (Australia); Elsey, J. [Bandwidth Foundry Pty Ltd, Australian Technology Park, NSW, 1430 (Australia); McKenzie, D.R. [School of Physics, University of Sydney, NSW 2006 (Australia)

    2007-04-15

    In-vivo dosimetry for brachytherapy cancer treatment requires a small dosimeter with a real time readout capability that can be inserted into the patient to determine the dose to critical organs. Fibre optic scintillation dosimeters, consisting of a plastic scintillator coupled to an optical fibre, are a promising dosimeter for this application. We have implemented specific design features to optimise the performance of the dosimeter for specific in-vivo dosimetry during brachytherapy. Two sizes of the BrachyFOD{sup TM} scintillation dosimeter have been developed, with external diameters of approximately 2 and 1 mm. We have determined their important dosimetric characteristics (depth dose relation, angular dependence, energy dependence). We have shown that the background signal created by Cerenkov and fibre fluorescence does not significantly affect the performance in most clinical geometries. The dosimeter design enables readout at less than 0.5 s intervals. The clinical demands of real time in-vivo brachytherapy dosimetry can uniquely be satisfied by the BrachyFOD{sup TM}.

  7. Transradial coronary brachytherapy with the Novoste Beta-Rail system.

    Science.gov (United States)

    Bertrand, Olivier F; De Larochellière, Robert; Gleeton, Onil; Plante, Sylvain; Tessier, Michel; Guimond, Jean

    2002-03-01

    We report our initial experience in 10 consecutive patients who underwent transradial coronary brachytherapy for in-stent restenosis using a 90Sr/Y source and the Novoste Beta-Rail system. In all patients, procedures were successfully completed using a right transradial approach. We performed the procedures with the Beta-Rail catheter using 7 Fr (Zuma II, Medtronic, MN; n = 5) or 8 Fr (Cordis, Miami, FL; n = 5) guiding catheters. All lesions were successfully dilated and no additional stent was inserted. We used a 40 mm source (n = 3) or a 60 mm source (n = 7) with manual stepping in four cases. In three cases, we did one stepping, and in one case, we did three steppings. The mean dwell time was 195 plus minus 44 sec. The mean delivered dose was 23 +/- 3 Gy at 2 mm distance from the source. No radiation treatment was interrupted. Mean fluoroscopy time was 26 +/- 13 min. Procedural success was achieved in all patients. Three patients had mild CK elevations (< 3 times upper normal limit). All patients were pretreated with clopidogrel (300 mg) and combined treatment with aspirin + clopidogrel is to be continued for at least 1 year. Clinical follow-up up to 3 months has not yielded any complication and all patients have remained free from angina.

  8. SU-E-T-564: Multi-Helix Rotating Shield Brachytherapy for Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, H; Wu, X [University of Iowa, Iowa City, IA (United States); Flynn, R; Kim, Y [University of Iowa Hospitals and Clinics, Iowa City, IA (United States)

    2015-06-15

    Purpose: To present a novel and practical brachytherapy technique, called multi-helix rotating shield brachytherapy (H-RSBT), for the precise positioning of a partial shield in a curved applicator. H-RSBT enables RSBT delivery using only translational motion of the radiation source/shield combination. H-RSBT overcomes the challenges associated with previously proposed RSBT approaches based on a serial (S-RSBT) step-and-shoot delivery technique, which required independent translational and rotational motion. Methods: A Fletcher-type applicator, compatible with the combination of a Xoft Axxent™ electronic brachytherapy source and a 0.5 mm thick tungsten shield, is proposed. The wall of the applicator contains six evenly-spaced helical keyways that rigidly define the emission direction of the shield as a function of depth. The shield contains three protruding keys and is attached to the source such that it rotates freely. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients representative of a wide range of high-risk clinical target volume (HR-CTV) shapes and applicator positions. The number of beamlets used in the treatment planning process was nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. For all the treatment plans the EQD2 of the HR-CTV was escalated until the EQD{sub 2cc} tolerance of either the bladder, rectum, or sigmoid colon was reached. Results: Treatment times for H-RSBT tended to be shorter than for S-RSBT, with changes of −38.47% to 1.12% with an average of −8.34%. The HR-CTV D{sub 90} changed by −8.81% to 2.08% with an average of −2.46%. Conclusion: H-RSBT is a mechanically feasible technique in the curved applicators needed for cervical cancer brachytherapy. S-RSBT and H-RSBT dose distributions were clinically equivalent for all patients

  9. American Society for Therapeutic Radiology and Oncology (ASTRO) Emerging Technology Committee report on electronic brachytherapy.

    Science.gov (United States)

    Park, Catherine C; Yom, Sue S; Podgorsak, Matthew B; Harris, Eleanor; Price, Robert A; Bevan, Alison; Pouliot, Jean; Konski, Andre A; Wallner, Paul E

    2010-03-15

    The development of novel technologies for the safe and effective delivery of radiation is critical to advancing the field of radiation oncology. The Emerging Technology Committee of the American Society for Therapeutic Radiology and Oncology appointed a Task Group within its Evaluation Subcommittee to evaluate new electronic brachytherapy methods that are being developed for, or are already in, clinical use. The Task Group evaluated two devices, the Axxent Electronic Brachytherapy System by Xoft, Inc. (Fremont, CA), and the Intrabeam Photon Radiosurgery Device by Carl Zeiss Surgical (Oberkochen, Germany). These devices are designed to deliver electronically generated radiation, and because of their relatively low energy output, they do not fall under existing regulatory scrutiny of radioactive sources that are used for conventional radioisotope brachytherapy. This report provides a descriptive overview of the technologies, current and future projected applications, comparison of competing technologies, potential impact, and potential safety issues. The full Emerging Technology Committee report is available on the American Society for Therapeutic Radiology and Oncology Web site.

  10. Variability of marker-based rectal dose evaluation in HDR cervical brachytherapy.

    Science.gov (United States)

    Wang, Zhou; Jaggernauth, Wainwright; Malhotra, Harish K; Podgorsak, Matthew B

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  11. Optical fibre luminescence sensor for real-time LDR brachytherapy dosimetry

    Science.gov (United States)

    Woulfe, P.; Sullivan, F. J.; O'Keeffe, S.

    2016-05-01

    An optical fibre sensor for monitoring low dose radiation is presented. The sensor is based on a scintillation material embedded within the optical fibre core, which emits visible light when exposed to low level ionising radiation. The incident level of ionising radiation can be determined by analysing the optical emission. An optical fibre sensor is presented, based on radioluminescence whereby radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 250μm of a 500μm plastic optical fibre. The sensor is designed for in-vivo monitoring of the radiation dose during radio-active seed implantation for brachytherapy, in prostate cancer treatment, providing oncologists with real-time information of the radiation dose to the target area and/or nearby critical structures. The radiation from the brachytherapy seeds causes emission of visible light from the scintillation material through the process of radioluminescence, which penetrates the fibre, propagating along the optical fibre for remote detection using a multi-pixel photon counter. The sensor demonstrates a high sensitivity to Iodine-125, the radioactive source most commonly used in brachytherapy for treating prostate cancer.

  12. Prospective multi-center trial utilizing electronic brachytherapy for the treatment of endometrial cancer

    Directory of Open Access Journals (Sweden)

    Thropay John P

    2010-07-01

    Full Text Available Abstract Background A modified form of high dose rate (HDR brachytherapy has been developed called Axxent Electronic Brachytherapy (EBT. EBT uses a kilovolt X-ray source and does not require treatment in a shielded vault or a HDR afterloader unit. A multi-center clinical study was carried out to evaluate the success of treatment delivery, safety and toxicity of EBT in patients with endometrial cancer. Methods A total of 15 patients with stage I or II endometrial cancer were enrolled at 5 sites. Patients were treated with vaginal EBT alone or in combination with external beam radiation. Results The prescribed doses of EBT were successfully delivered in all 15 patients. From the first fraction through 3 months follow-up, there were 4 CTC Grade 1 adverse events and 2 CTC Grade II adverse events reported that were EBT related. The mild events reported were dysuria, vaginal dryness, mucosal atrophy, and rectal bleeding. The moderate treatment related adverse events included dysuria, and vaginal pain. No Grade III or IV adverse events were reported. The EBT system performed well and was associated with limited acute toxicities. Conclusions EBT shows acute results similar to HDR brachytherapy. Additional research is needed to further assess the clinical efficacy and safety of EBT in the treatment of endometrial cancer.

  13. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Torres H, F. [Universidad de Cordoba, Materials and Applied Physics Group, 230002 Monteria, Cordoba (Colombia); De la Espriella V, N. [Universidad de Cordoba, Grupo Avanzado de Materiales y Sistemas Complejos, 230002 Monteria, Cordoba (Colombia); Sanchez C, A., E-mail: franciscotorreshoyos@yahoo.com [Universidad de Cordoba, Departamento de Enfermeria, 230002 Monteria, Cordoba (Colombia)

    2014-07-01

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  14. Radiation protection for an intraoperative X-ray source compared to C-arm fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Frank; Clausen, Sven; Jahnke, Anika; Steil, Volker; Wenz, Frederik [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Radiation Oncology; Bludau, Frederic; Obertacke, Udo [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Trauma Surgery; Suetterlin, Marc [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Obstetrics and Gynaecology

    2014-10-01

    Background: Intraoperative radiotherapy (IORT) using the INTRABEAM {sup registered} system promises a flexible use regarding radiation protection compared to other approaches such as electron treatment or HDR brachytherapy with {sup 192}Ir or {sup 60}Co. In this study we compared dose rate measurements of breast- and Kypho-IORT with C-arm fluoroscopy which is needed to estimate radiation protection areas. Materials and Methods: C-arm fluoroscopy, breast- and Kypho-IORTs were performed using phantoms (silicon breast or bucket of water). Dose rates were measured at the phantom's surface, at 30 cm, 100 cm and 200 cm distance. Those measurements were confirmed during 10 Kypho-IORT and 10 breast-IORT patient treatments. Results: The measured dose rates were in the same magnitude for all three paradigms and ranges from 20 μSv/h during a simulated breast-IORT at two meter distance up to 64 mSv/h directly at the surface of a simulated Kypho-IORT. Those measurements result in a circle of controlled area (yearly doses > 6 mSv) for each paradigm of about 4 m ± 2 m. Discussion/Conclusions: All three paradigms show comparable dose rates which implies that the radiation protection is straight forward and confirms the flexible use of the INTRABEAM {sup registered} system. (orig.)

  15. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Georg, Dietmar, E-mail: Dietmar.Georg@akhwien.at [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hopfgartner, Johannes [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Gòra, Joanna [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kuess, Peter [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kragl, Gabriele [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Berger, Daniel [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hegazy, Neamat [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Goldner, Gregor; Georg, Petra [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria)

    2014-03-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ({sup 192}Ir) and LDR-BT ({sup 125}I) were D{sub 90%} ≥34 Gy in 8.5 Gy per fraction and D{sub 90%} ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D{sub mean} around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques

  16. Suitability of point kernel dose calculation techniques in brachytherapy treatment planning

    Directory of Open Access Journals (Sweden)

    Lakshminarayanan Thilagam

    2010-01-01

    Full Text Available Brachytherapy treatment planning system (TPS is necessary to estimate the dose to target volume and organ at risk (OAR. TPS is always recommended to account for the effect of tissue, applicator and shielding material heterogeneities exist in applicators. However, most brachytherapy TPS software packages estimate the absorbed dose at a point, taking care of only the contributions of individual sources and the source distribution, neglecting the dose perturbations arising from the applicator design and construction. There are some degrees of uncertainties in dose rate estimations under realistic clinical conditions. In this regard, an attempt is made to explore the suitability of point kernels for brachytherapy dose rate calculations and develop new interactive brachytherapy package, named as BrachyTPS, to suit the clinical conditions. BrachyTPS is an interactive point kernel code package developed to perform independent dose rate calculations by taking into account the effect of these heterogeneities, using two regions build up factors, proposed by Kalos. The primary aim of this study is to validate the developed point kernel code package integrated with treatment planning computational systems against the Monte Carlo (MC results. In the present work, three brachytherapy applicators commonly used in the treatment of uterine cervical carcinoma, namely (i Board of Radiation Isotope and Technology (BRIT low dose rate (LDR applicator and (ii Fletcher Green type LDR applicator (iii Fletcher Williamson high dose rate (HDR applicator, are studied to test the accuracy of the software. Dose rates computed using the developed code are compared with the relevant results of the MC simulations. Further, attempts are also made to study the dose rate distribution around the commercially available shielded vaginal applicator set (Nucletron. The percentage deviations of BrachyTPS computed dose rate values from the MC results are observed to be within plus/minus 5

  17. Characteristics of the radiochromic film Gafchromictm EBT3 model for use in brachytherapy; Caracterizacao do filme radiocromico Gafchromictm modelo EBT3 para uso em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Luvizotto, Jessica

    2015-07-01

    Brachytherapy is a radiotherapy treatment modality using radioactive sealed sources within walking distance of the tumor, reducing the risk of applying an unwanted dose to adjacent healthy tissues. For brachytherapy is reliable, it is necessary to establish a dosimetric practices program aimed at determining the optimal dose of radiation for this radiotherapy practice. This paper presents the application of two methodologies for the dosimetry using radiochromic films. Experimental measurements were performed with EBT3 films in phantoms consisting of homogeneous and heterogeneous material (lung, bone and soft tissue) built especially for dose measurements in brachytherapy. The processing and analysis of the resulting images of the experimental procedure were performed with ImageJ software and MATLAB. The results were evaluated from comparisons dose of experimental measurements and simulations obtained by the Monte Carlo method. (author)

  18. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: report of Task Group 192.

    Science.gov (United States)

    Podder, Tarun K; Beaulieu, Luc; Caldwell, Barrett; Cormack, Robert A; Crass, Jostin B; Dicker, Adam P; Fenster, Aaron; Fichtinger, Gabor; Meltsner, Michael A; Moerland, Marinus A; Nath, Ravinder; Rivard, Mark J; Salcudean, Tim; Song, Danny Y; Thomadsen, Bruce R; Yu, Yan

    2014-10-01

    mimic the real operating procedure as closely as possible. Additional recommendations on robotic brachytherapy systems include display of the operational state; capability of manual override; documented policies for independent check and data verification; intuitive interface displaying the implantation plan and visualization of needle positions and seed locations relative to the target anatomy; needle insertion in a sequential order; robot-clinician and robot-patient interactions robustness, reliability, and safety while delivering the correct dose at the correct site for the correct patient; avoidance of excessive force on radioactive sources; delivery confirmation of the required number or position of seeds; incorporation of a collision avoidance system; system cleaning, decontamination, and sterilization procedures. These recommendations are applicable to end users and manufacturers of robotic brachytherapy systems.

  19. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K., E-mail: tarun.podder@uhhospitals.org [Department of Radiation Oncology, University Hospitals, Case Western Reserve University, Cleveland, Ohio 44122 (United States); Beaulieu, Luc [Department of Radiation Oncology, Centre Hospitalier Univ de Quebec, Quebec G1R 2J6 (Canada); Caldwell, Barrett [Schools of Industrial Engineering and Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Cormack, Robert A. [Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Crass, Jostin B. [Department of Radiation Oncology, Vanderbilt University, Nashville, Tennessee 37232 (United States); Dicker, Adam P.; Yu, Yan [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Fenster, Aaron [Department of Imaging Research, Robarts Research Institute, London, Ontario N6A 5K8 (Canada); Fichtinger, Gabor [School of Computer Science, Queen’s University, Kingston, Ontario K7L 3N6 (Canada); Meltsner, Michael A. [Philips Radiation Oncology Systems, Fitchburg, Wisconsin 53711 (United States); Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht, 3508 GA (Netherlands); Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Salcudean, Tim [Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Song, Danny Y. [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Thomadsen, Bruce R. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2014-10-15

    should mimic the real operating procedure as closely as possible. Additional recommendations on robotic brachytherapy systems include display of the operational state; capability of manual override; documented policies for independent check and data verification; intuitive interface displaying the implantation plan and visualization of needle positions and seed locations relative to the target anatomy; needle insertion in a sequential order; robot–clinician and robot–patient interactions robustness, reliability, and safety while delivering the correct dose at the correct site for the correct patient; avoidance of excessive force on radioactive sources; delivery confirmation of the required number or position of seeds; incorporation of a collision avoidance system; system cleaning, decontamination, and sterilization procedures. These recommendations are applicable to end users and manufacturers of robotic brachytherapy systems.

  20. The application of Geant4 simulation code for brachytherapy treatment

    CERN Document Server

    Agostinelli, S; Garelli, S; Paoli, G; Nieminen, P; Pia, M G

    2000-01-01

    Brachytherapy is a radiotherapeutic modality that makes use of radionuclides to deliver a high radiation dose to a well-defined volume while sparing surrounding healthy structures. At the National Institute for Cancer Research of Genova a High Dose Rate remote afterloading system provides Ir(192) endocavitary brachytherapy treatments. We studied the possibility to use the Geant4 Monte Carlo simulation toolkit in brachytherapy for calculation of complex physical parameters, not directly available by experiment al measurements, used in treatment planning dose deposition models.

  1. Construction of a anthropomorphic phantom for dose measurement in hands in brachytherapy procedures; Construccion de un fantoma antropomorfico para mediciones de dosis en manos en procedimientos de braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Papp, Cinthia M., E-mail: cinthia_papp@yahoo.com.ar [Comision Nacional de Energia Atomica (IH/UNCUYO/CNEA), Mendoza (Argentina). Universidad Nacional de Cuyo. Instituto Balseiro; Ortiz, Arnulfo; Alvarez, Guillermo, E-mail: arnot@gmail.com, E-mail: galvarez@fuesmen.edu.ar [Fundacion Escuela de Medicina Nuclear (FUESMEN), Mendoza (Argentina)

    2013-11-01

    The main objective of this work was to show the differences between the dose value measured by dosimeter endpoint and the values measured in different points inside the hand during brachytherapy procedures. For this, the procedures involved in the handling of sources were analyzed and the simulated using an anthropomorphic phantom hand.

  2. Applicability of a prototype for determination of absorbed dose using brachytherapy equipment with Ir-192 sources; Aplicabilidade de um prototipo para determinacao da dose absorvida utilizando equipamentos de braquiterapia com fontes de IR-192

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vivianne Lucia Bormann; Almeida, Mayara Gabriella Oliveira de; Vieira, Rafaela Etelvina de Amorim; Silva, Waldecy Ananias da; Nascimento, Rizia Keila, E-mail: vlsouza@cnen.gov.br, E-mail: mayaradqf@hotmail.com, E-mail: rodriguesss@hootmail.com, E-mail: waldecy@cnen.gov.br, E-mail: riziakeila@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2014-07-01

    This work aims at the development and improvement of a device to perform the absolute dosimetry sources of Ir-192 using the Fricke solution contained in a flask. The Fricke solution used was prepared using amounts of ferrous ammonium sulfate, sodium chloride and sulfuric acid, diluted with water tri distilled pre-established in the literature. The spectrophotometer used was a UV-VIS spectrophotometer (Beckman DU-640 Counter) for measuring the optical density at wavelength 304 nm. The calculation for determining the radial dose takes into account the radial distance and the angle formed with the transverse axis of the source. As the results obtained can be seen that the states of Pernambuco, Ceara, Paraiba e Piaui are in accordance with the recommendations of international standards of the International Atomic Energy Agency (IAEA), which considers not acceptable a difference greater than 5% of prescribed dose and measured dose.

  3. LOW POWER BRACHYTHERAPY IN COMBINED TREATMENT IN PATIENTS WITH INTERMEDIATE RISK OF LOCALIZED PROST ATE CANCER

    Directory of Open Access Journals (Sweden)

    V. A. Biryukov

    2014-01-01

    Full Text Available Objective. Estimation of the effectiveness of low power brachytherapy sources I-125 in the combined treatment in group of patients of intermediate risk of localized prostate cancer.Material and methods. The study included 126 patients with prostate cancer of intermediate risk. 104 patients (83,9% were conducted low power brachytherapy I‑125 in combination with hormone therapy by analogues of LHWG. 22 patients (16.1% received external beam irradiation in combination with brachytherapy I‑125 and hormonal treatment. Relapse-free survival of patients was evaluated in accordance with the criteria Phoenix (Nadir PSA + ng/ml. Evaluation of side effects of radiation treatment were carried out according to the RTOG criteria.Results. PSA relapse-free survival in the group of brachytherapy and hormone treatment at the time of observation 5 years amounted to 97.1%. In the group of combined radiation therapy with brachytherapy, and hormonal treatment PSA relapse-free survival rate was 95.5%.In both groups, relapse-free survival was noted in 96,8% of cases. Tumor-specific and overall survival in bothgroups was 100%. The major complications of treatment in both groups were radiation urethritis 1 to 2 degrees in 9.5% of cases (12 patients, urethral stricture in 5 patients (3.9% of cases, acute urinary retention in 1 patient (0.8% of cases and late radiation rectitis of 2 degree in 1.58% of cases (2 patients.Conclusions. It is possible to draw tentative conclusions about the high rate of survival without progression in both treatment groups on the background of the relatively low frequency of adverse reactions. It is necessary further follow-up for patients with estimating of survival for a longer period.

  4. Development of irradiation support devices for production of brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Fabio R.; Rostelato, Maria Elisa C.M.; Zeituni, Carlos A.; Souza, Carla D.; Moura, Joao A.; Peleias Junior, Fernando S.; Karan Junior, Dib; Feher, Anselmo; Oliveira, Tiago B.; Benega, Marcos A.G., E-mail: tiagooliveira298@gmail.com, E-mail: mattos.fr@gmail.com, E-mail: elisaros@ipen.br, E-mail: czeituni@ipen.br, E-mail: carladdsouza@yahoo.com.br, E-mail: jamoura@ipen.br, E-mail: ernandopeleias@gmail.com, E-mail: s, E-mail: dib.karan@usp.br, E-mail: afeher@ipen.br, E-mail: marcosagbenega@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Ophthalmic tumors treatment with brachytherapy sources has been widely used as a primary or secondary therapy for non-malignant or malignant tumors, for example, choroid melanoma, and retinoblastoma. Ruthenium-106, Iodine-125, Palladium -103, Gold-198 and Iridium-192, are some radionuclides that can be applied for treatment of ocular tumors. These sources are in small sizes (a few millimeters) and different shapes (rods, wires, disks). To ensure high accuracy during treatment, they are positioned in eye applicators, specially designed to fit on the surface of tumor. The Nuclear and Energy Research Institute (IPEN/CNEN) in a partnership with Paulista Medicine School (UNIFESP) created a project that aims to develop a prototype of Iridium-192 seeds for treatment of eye cancer. This seed consists in a core of Ir -Pt alloy (20%-80%) with a length of 3 mm, to be activated in IPEN's IEA-R1 Reactor, and a titanium capsule sealing the core. It was imperative to develop a sustainer device for irradiation. This piece is used to avoid overlapping of one cores and, therefore, avoiding the 'shadow effect' that does not allow full activation of each core due to the high density. (author)

  5. Application of spherical micro diodes for brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Broisman, Andrey, E-mail: andreybr@ariel.ac.i [Medical Physics, Ariel University Center, Ariel 40700 (Israel); Shani, Gad [Biomedical Engineering, Ben Gurion University, P.O. Box 653, Beer Sheva 84105 (Israel)

    2011-03-15

    The research presented in this paper demonstrates the feasibility and the advantages of using spherical micro diodes for radiation dosimetry. The spherical symmetry of the diode response is demonstrated, compared to that of planar diodes. The application of the spherical diode described here is for radiotherapy dosimetry, particularly brachytherapy. Measurements were done in PMMA phantoms. The advantage of the spherical diode is that it can be used for radiation measurement in a 4{pi} geometry, it was demonstrated by measurements in both axial and azimuthal planes. The diodes were found to respond equally to radiation coming from all directions, directly from the source or due to scattered radiation within the medium. In the present work 1.8 mm diameter silicone diodes were used. The small size of these spherical diodes provides local dose measurement and can be used for in situ dosimetry while treatment takes place. Treatment planning correction can be made accordingly. Commercially available seeds of the isotopes I{sup 125} and Pd{sup 103} were used as radiation sources. The spherical diodes response was compared with that of planar diodes XRB generally used for UV and X-ray dosimetry, and with TLD measurements. We have also compared the measured results with Monte Carlo simulation, applying the MCNP code and with calculations shown in the TG-43 report.

  6. A study of brachytherapy for intraocular tumor

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yung Hoon; Lee, Dong Han; Ko, Kyung Hwan; Lee, Tae Won; Lee, Sung Koo; Choi, Moon Sik [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Seoul (Korea, Republic of)

    1994-12-01

    Our purpose of this study is to perform brachytherapy for intraocular tumor. The result were as followed. 1. Eye model was determined as a 25 mm diameter sphere. Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15 mm, 17 mm and 20 mm in diameter, and 1.5 mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5 mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within {+-}10% and distance deviations are within 0.4 mm. Maximum error is -11.3% and 0.8 mm, respectively. 7 figs, 2 tabs, 28 refs. (Author).

  7. Image-Based Brachytherapy for the Treatment of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harkenrider, Matthew M., E-mail: mharkenrider@lumc.edu; Alite, Fiori; Silva, Scott R.; Small, William

    2015-07-15

    Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy.

  8. Brachytherapy in thetreatment of the oral and oropharyngeal cancer

    Directory of Open Access Journals (Sweden)

    A. M. Zhumankulov

    2015-01-01

    Full Text Available Background. One of the methods of radiotherapy of malignant tumors of oral cavity and oropharyngeal region today is interstitial radiation therapy – brachytherapy, allowing you to create the optimum dose of irradiation to the tumor, necessary for its destruction, without severe radiation reactions in the surrounding tissues unchanged. Brachytherapy has the following advantages: high precision – the ability of the local summarization of high single doses in a limited volume of tissue; good tolerability; a short time of treatment. At this time, brachytherapy is the method of choice used as palliative therapy and as a component of radical treatment.Objective: The purpose of this article is a literature review about the latest achievements of interstitial brachytherapy in malignant tumors of the oral cavity and oropharynx.

  9. Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

    CERN Document Server

    Lemoigne, Yves

    2009-01-01

    This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

  10. Ocular Brachytherapy Dosimetry for 103Pd and 125I in The Presence of Gold Nanoparticles: Monte Carlo Study

    CERN Document Server

    Asadi, S; Vahidian, M; Marghchouei, M; Masoudi, S Farhad

    2015-01-01

    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 have been taken into account for both mentioned brachytherapy sources. Also, in a certain point 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 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 results show that the calculated dose enhancement factor in the tumor for 125I is higher tha...

  11. The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

    Energy Technology Data Exchange (ETDEWEB)

    D.L. Henderson; S. Yoo; M. Kowalok; T.R. Mackie; B.R. Thomadsen

    2001-10-30

    The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-metere from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a minimum.

  12. Review of advanced catheter technologies in radiation oncology brachytherapy procedures

    OpenAIRE

    Zhou J.; Zamdborg L; Sebastian E

    2015-01-01

    Jun Zhou,1,2 Leonid Zamdborg,1 Evelyn Sebastian1 1Department of Radiation Oncology, Beaumont Health System, 2Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA Abstract: The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy ...

  13. Electromagnetic tracking for treatment verification in interstitial brachytherapy

    Science.gov (United States)

    Kellermeier, Markus; Tanderup, Kari

    2016-01-01

    Electromagnetic tracking (EMT) is used in several medical fields to determine the position and orientation of dedicated sensors, e.g., attached to surgical tools. Recently, EMT has been introduced to brachytherapy for implant reconstruction and error detection. The manuscript briefly summarizes the main issues of EMT and error detection in brachytherapy. The potential and complementarity of EMT as treatment verification technology will be discussed in relation to in vivo dosimetry and imaging. PMID:27895688

  14. Intraluminal brachytherapy in the treatment of bile duct carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Leung, J.T. [Adelaide Radiotherapy Centre, Adelaide, SA (Australia); Kuan, R. [Sir Charles Gairdner Hospital, Nedlands, Perth, WA (Australia)

    1997-05-01

    Patients with carcinoma of the biliary tract have a poor prognosis because the disease is often unresectable at diagnosis. Intraluminal brachytherapy has been reported as an effective treatment for localized cholangiocarcinoma of the biliary tract. The purpose of our study was to analyse the survival of patients treated with brachytherapy and make some recommendations regarding its use. Fifteen patients underwent brachytherapy via a trans-hepatic approach at the Royal Prince Alfred Hospital from 1983 to 1993. Eleven patients had low-dose rate brachytherapy and four patients had high-dose rate treatment. There were nine males and six females. The median age was 64 years. Other treatment included bypass procedures in two patients, endoscopic stents in 14 patients and external beam irradiation in one patient. The median survival was 12.5 months and 47% of the patients survived 1 year. The only complication reported was cholangitis which was seen in one patient. There did not seem to be any difference in survival or complications between low- and high-dose rate brachytherapy. It is concluded that the addition of intraluminal brachytherapy after biliary drainage prolongs survival and is a safe and effective treatment, but patients still have a high rate of local failure, and further studies will be needed to address this problem. (authors). 28 refs., 3 figs.

  15. 78 FR 41125 - Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting

    Science.gov (United States)

    2013-07-09

    ... COMMISSION Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting AGENCY... Commission (NRC) is issuing an interim Enforcement Policy that allows the staff to exercise enforcement...'s permanent implant brachytherapy program. This interim policy affects NRC licensees that...

  16. A review of the clinical experience in pulsed dose rate brachytherapy.

    Science.gov (United States)

    Balgobind, Brian V; Koedooder, Kees; Ordoñez Zúñiga, Diego; Dávila Fajardo, Raquel; Rasch, Coen R N; Pieters, Bradley R

    2015-01-01

    Pulsed dose rate (PDR) brachytherapy is a treatment modality that combines physical advantages of high dose rate (HDR) brachytherapy with the radiobiological advantages of low dose rate brachytherapy. The aim of this review was to describe the effective clinical use of PDR brachytherapy worldwide in different tumour locations. We found 66 articles reporting on clinical PDR brachytherapy including the treatment procedure and outcome. Moreover, PDR brachytherapy has been applied in almost all tumour sites for which brachytherapy is indicated and with good local control and low toxicity. The main advantage of PDR is, because of the small pulse sizes used, the ability to spare normal tissue. In certain cases, HDR resembles PDR brachytherapy by the use of multifractionated low-fraction dose.

  17. Dosimetry in intravascular brachytherapy; Calculos dosimetricos em braquiterapia intravascular

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Laelia Pumilla Botelho

    2000-03-01

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing {sup 32} P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  18. Accuracy Evaluation of Oncentra™ TPS in HDR Brachytherapy of Nasopharynx Cancer Using EGSnrc Monte Carlo Code

    Directory of Open Access Journals (Sweden)

    Hadad K

    2015-03-01

    Full Text Available Background: HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS is particularly important. Common methods used in TPS dosimetry are based on computations in a homogeneous phantom. Heterogeneous phantoms, especially patient-specific voxel phantoms can increase dosimetric accuracy. Materials and Methods: In this study, using CT images taken from a patient and ctcreate-which is a part of the DOSXYZnrc computational code, patient-specific phantom was made. Dose distribution was plotted by DOSXYZnrc and compared with TPS one. Also, by extracting the voxels absorbed dose in treatment volume, dosevolume histograms (DVH was plotted and compared with Oncentra™ TPS DVHs. Results: The results from calculations were compared with data from Oncentra™ treatment planning system and it was observed that TPS calculation predicts lower dose in areas near the source, and higher dose in areas far from the source relative to MC code. Absorbed dose values in the voxels also showed that TPS reports D90 value is 40% higher than the Monte Carlo method. Conclusion: Today, most treatment planning systems use TG-43 protocol. This protocol may results in errors such as neglecting tissue heterogeneity, scattered radiation as well as applicator attenuation. Due to these errors, AAPM emphasized departing from TG-43 protocol and approaching new brachytherapy protocol TG-186 in which patient-specific phantom is used and heterogeneities are affected in dosimetry

  19. Braquiterapia guiada por imagen Image-guided brachytherapy

    Directory of Open Access Journals (Sweden)

    E. Villafranca

    2009-01-01

    calculation possible. In recent years there have been changes affecting two aspects of brachytherapy. In the first place, the incorporation of imaging techniques such as echography, computerised tomography (CT and magnetic resonance (MR, indispensable for diagnosis and tumoural staging. Their use when the implant is being done helps in guiding and carrying out the operation with greater precision. In the second place, the use of CT, MR and echography makes better coverage of the tumour possible, or reduces the dose to healthy organs. They are used in inverse planning systems, which carry out dose calculation on the basis of the doses to be administered to the tumour and healthy organs. In these planning programs it is possible to make calculations more rapidly, taking account of the placement of the source at each moment in time. This technique, called real-time planning, is starting to show advantages in the treatment of prostate cancer. Incorporation of imaging techniques and improvements in calculation systems mean that brachytherapy is currently playing an important role in treating cancer of the prostate, cervix, breast, head and neck tumours, bronchial tubes or oesophagus.

  20. Toward endobronchial Ir-192 high-dose-rate brachytherapy therapeutic optimization

    Energy Technology Data Exchange (ETDEWEB)

    Gay, H A [Department of Radiation Oncology, Brody School of Medicine at East Carolina University, Greenville, NC (United States); Allison, R R [Department of Radiation Oncology, Brody School of Medicine at East Carolina University, Greenville, NC (United States); Downie, G H [Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, NC (United States); Mota, H C [Department of Radiation Oncology, Brody School of Medicine at East Carolina University, Greenville, NC (United States); Austerlitz, C [Department of Radiation Oncology, Brody School of Medicine at East Carolina University, Greenville, NC (United States); Jenkins, T [Department of Radiation Oncology, Brody School of Medicine at East Carolina University, Greenville, NC (United States); Sibata, C H [Department of Radiation Oncology, Brody School of Medicine at East Carolina University, Greenville, NC (United States)

    2007-06-07

    A number of patients with lung cancer receive either palliative or curative high-dose-rate (HDR) endobronchial brachytherapy. Up to a third of patients treated with endobronchial HDR die from hemoptysis. Rather than accept hemoptysis as an expected potential consequence of HDR, we have calculated the radial dose distribution for an Ir-192 HDR source, rigorously examined the dose and prescription points recommended by the American Brachytherapy Society (ABS), and performed a radiobiological-based analysis. The radial dose rate of a commercially available Ir-192 source was calculated with a Monte Carlo simulation. Based on the linear quadratic model, the estimated palliative, curative and blood vessel rupture radii from the center of an Ir-192 source were obtained for the ABS recommendations and a series of customized HDR prescriptions. The estimated radius at risk for blood vessel perforation for the ABS recommendations ranges from 7 to 9 mm. An optimized prescription may in some situations reduce this radius to 4 mm. The estimated blood perforation radius is generally smaller than the palliative radius. Optimized and individualized endobronchial HDR prescriptions are currently feasible based on our current understanding of tumor and normal tissue radiobiology. Individualized prescriptions could minimize complications such as fatal hemoptysis without sacrificing efficacy. Fiducial stents, HDR catheter centering or spacers and the use of CT imaging to better assess the relationship between the catheter and blood vessels promise to be useful strategies for increasing the therapeutic index of this treatment modality. Prospective trials employing treatment optimization algorithms are needed.

  1. Endovascular brachytherapy from Re-188-filled balloon catheter to prevent restenosis following angioplasty; Endovaskulaere Brachytherapie mit einem Re-188-gefuellten Ballonkatheter zur Praevention der Restenose nach Angioplastie

    Energy Technology Data Exchange (ETDEWEB)

    Kotzerke, J. [Ulm Univ. (Germany). Abt. Nuklearmedizin; Kropp, J. [Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2001-12-01

    Stent implantation and endovascular brachytherapy are the single effective methods to reduce restenosis after angioplasty. Gamma- and beta-emitter can be applied. The use of a liquid beta-emitter filled balloon catheter allows nuclear medicine to participate in this new concept of therapy due to the unsealed source. From various beta-emitters Re-188-perrhenate seems to be the most attractive one regarding logistic, radiation protection and costs. Feasibility of the method was demonstrated by several groups. Interim analysis of ECRIS-2 demonstrate an effectiveness comparable to the best of other irradiation data. (orig.) [German] Die endovaskulaere Brachytherapie ist neben der Stentimplantation bisher die einzige Methode, mit der die Restenoserate nach Angioplastie (PTCA) deutlich reduziert werden kann. Sowohl Gamma- wie auch Betastrahler sind einsetzbar. Die Anwendung eines fluessigen Betastrahlers in einem Ballonkatheter erlaubt dem Nuklearmediziner, an diesem Therapiekonzept zu partizipieren, da es sich um die Anwendung eines offenen radioaktiven Isotops handelt. Von den diversen moeglichen Betastrahlern erscheint Re-188-Perrhenat am geeignetsten zu sein im Hinblick auf die Logistik, den Strahlenschutz und die Kosten. Die Praktikabilitaet dieser Methode wurde von mehreren Zentren bestaetigt. Eine Zwischenauswertung der ECRIS-2-Studie aus Ulm ergibt Daten, die grossen amerikanischen Studien keineswegs nachstehen. (orig.)

  2. A dynamic dosimetry system for prostate brachytherapy

    Science.gov (United States)

    Kuo, Nathanael; Dehghan, Ehsan; Deguet, Anton; Song, Danny Y.; Prince, Jerry L.; Lee, Junghoon

    2013-03-01

    The lack of dynamic dosimetry tools for permanent prostate brachytherapy causes otherwise avoidable problems in prostate cancer patient care. The goal of this work is to satisfy this need in a readily adoptable manner. Using the ubiquitous ultrasound scanner and mobile non-isocentric C-arm, we show that dynamic dosimetry is now possible with only the addition of an arbitrarily configured marker-based fiducial. Not only is the system easily configured from accessible hardware, but it is also simple and convenient, requiring little training from technicians. Furthermore, the proposed system is built upon robust algorithms of seed segmentation, fiducial detection, seed reconstruction, and image registration. All individual steps of the pipeline have been thoroughly tested, and the system as a whole has been validated on a study of 25 patients. The system has shown excellent results of accurately computing dose, and does so with minimal manual intervention, therefore showing promise for widespread adoption of dynamic dosimetry.

  3. Interstitial brachytherapy in carcinoma of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, A.J.; Ghosh, S.; Bhalavat, R.L. [Tata Memorial Hospital, Mumbai (India). Dept. of Radiation Oncology; Kulkarni, J.N. [Tata Memorial Hospital, Mumbai (India). Dept. of Surgery; Sequeira, B.V.E. [Tata Memorial Hospital, Mumbai (India). Dept. of Medical Physics

    1999-01-01

    Aim: Keeping in line with the increasing emphasis on organ preservation, we at the Tata Memorial Hospital have evaluated the role of Ir-192 interstitial implant as regards local control, functional and cosmetic outcome in early as well as locally recurrent carcinoma of the distal penis. Patients and Methods: From October 1988 to December 1996, 23 patients with histopathologically proven cancer of the penis were treated with radical radiation therapy using Ir-192 temporary interstitial implant. Our patients were in the age group of 20 to 60 years. The primary lesions were T1 and 7, T2 in 7 and recurrent in 9 patients. Only 7 patients had palpable groin nodes at presentation, all of which were pathologically negative. The median dose of implant was 50 Gy (range 40 to 60 Gy), using the LDR afterloading system and the Paris system of implant rules for dosimetry. Follow-up ranged from 4 to 117 months (median 24 months). Results: At last follow-up 18 of the 23 patients remained locally controlled with implant alone. Three patients failed only locally, 2 locoregionally and 1 only at the groin. Of the 5 patients who failed locally, 4 were successfully salvaged with partial penectomy and remained controlled when last seen. Local control with implant alone at 8 years was 70% by life table analysis. The patients had excellent functional and cosmetic outcome. We did not record any case of skin or softtissue necrosis. Only 2 patients developed meatal stenosis, both of which were treated endoscopically. Conclusion: Our results lead us to interpret that interstitial brachytherapy with Ir-192 offers excellent local control rates with preservation of organ and function. Penectomy can be reserved as a means for effective salvage. (orig.) [Deutsch] Ziel: Das Prinzip des Organerhalts gewinnt in der Onkologie zunehmend an Bedeutung. Ziel dieser Untersuchung war es, die Rolle der interstitiellen Brachytherapie mit Ir-192 zur Behandlung des fruehen und rezidivierten Peniskarzinoms zu

  4. Epoxy resins used to seal brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos, E-mail: nccf@cdtn.br, E-mail: ferrazw@cdtn.br, E-mail: reissc@cdtn.br, E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, BH (Brazil)

    2013-07-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  5. egs_brachy: a versatile and fast Monte Carlo code for brachytherapy

    Science.gov (United States)

    Chamberland, Marc J. P.; Taylor, Randle E. P.; Rogers, D. W. O.; Thomson, Rowan M.

    2016-12-01

    egs_brachy is a versatile and fast Monte Carlo (MC) code for brachytherapy applications. It is based on the EGSnrc code system, enabling simulation of photons and electrons. Complex geometries are modelled using the EGSnrc C++ class library and egs_brachy includes a library of geometry models for many brachytherapy sources, in addition to eye plaques and applicators. Several simulation efficiency enhancing features are implemented in the code. egs_brachy is benchmarked by comparing TG-43 source parameters of three source models to previously published values. 3D dose distributions calculated with egs_brachy are also compared to ones obtained with the BrachyDose code. Well-defined simulations are used to characterize the effectiveness of many efficiency improving techniques, both as an indication of the usefulness of each technique and to find optimal strategies. Efficiencies and calculation times are characterized through single source simulations and simulations of idealized and typical treatments using various efficiency improving techniques. In general, egs_brachy shows agreement within uncertainties with previously published TG-43 source parameter values. 3D dose distributions from egs_brachy and BrachyDose agree at the sub-percent level. Efficiencies vary with radionuclide and source type, number of sources, phantom media, and voxel size. The combined effects of efficiency-improving techniques in egs_brachy lead to short calculation times: simulations approximating prostate and breast permanent implant (both with (2 mm)3 voxels) and eye plaque (with (1 mm)3 voxels) treatments take between 13 and 39 s, on a single 2.5 GHz Intel Xeon E5-2680 v3 processor core, to achieve 2% average statistical uncertainty on doses within the PTV. egs_brachy will be released as free and open source software to the research community.

  6. Methods for prostate stabilization during transperineal LDR brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun; Yu Yan [Department of Radiation Oncology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Sherman, Jason [Department of Medical Physics, University of Buffalo, Buffalo, NY 14260 (United States); Rubens, Deborah; Strang, John [Departments of Imaging Science and Surgery, University of Rochester, Rochester, NY 14642 (United States); Messing, Edward [Departments of Urology and Surgery, University of Rochester, Rochester, NY 14642 (United States); Ng, Wan-Sing [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2008-03-21

    In traditional prostate brachytherapy procedures for a low-dose-rate (LDR) radiation seed implant, stabilizing needles are first inserted to provide some rigidity and support to the prostate. Ideally this will provide better seed placement and an overall improved treatment. However, there is much speculation regarding the effectiveness of using regular brachytherapy needles as stabilizers. In this study, we explored the efficacy of two types of needle geometries (regular brachytherapy needle and hooked needle) and several clinically feasible configurations of the stabilization needles. To understand and assess the prostate movement during seed implantation, we collected in vivo data from patients during actual brachytherapy procedures. In vitro experimentation with tissue-equivalent phantoms allowed us to further understand the mechanics behind prostate stabilization. We observed superior stabilization with the hooked needles compared to the regular brachytherapy needles (more than 40% in bilateral parallel needle configuration). Prostate movement was also reduced significantly when regular brachytherapy needles were in an angulated configuration as compared to the parallel configuration (more than 60%). When the hooked needles were angulated for stabilization, further reduction in prostate displacement was observed. In general, for convenience of dosimetric planning and to avoid needle collision, all needles are desired to be in a parallel configuration. In this configuration, hooked needles provide improved stabilization of the prostate. On the other hand, both regular and hooked needles appear to be equally effective in reducing prostate movement when they are in angulated configurations, which will be useful in seed implantation using a robotic system. We have developed nonlinear spring-damper model for the prostate movement which can be used for adapting dosimetric planning during brachytherapy as well as for developing more realistic haptic devices and

  7. Preparation of a program for the independent verification of the brachytherapy planning systems calculations; Confeccion de un programa para la verificacion independiente de los calculos de los sistemas de planificacion en braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    V Carmona, V.; Perez-Calatayud, J.; Lliso, F.; Richart Sancho, J.; Ballester, F.; Pujades-Claumarchirant, M.C.; Munoz, M.

    2010-07-01

    In this work a program is presented that independently checks for each patient the treatment planning system calculations in low dose rate, high dose rate and pulsed dose rate brachytherapy. The treatment planning system output text files are automatically loaded in this program in order to get the source coordinates, the desired calculation point coordinates and the dwell times when it is the case. The source strength and the reference dates are introduced by the user. The program allows implementing the recommendations about independent verification of the clinical brachytherapy dosimetry in a simple and accurate way, in few minutes. (Author).

  8. SU-E-P-05: Electronic Brachytherapy: A Physics Perspective On Field Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Pai, S; Ayyalasomayajula, S; Lee, S [iCAD Inc., Los Gatos, CA (United States)

    2015-06-15

    Purpose: We want to summarize our experience implementing a successful program of electronic brachytherapy at several dermatology clinics with the help of a cloud based software to help us define the key program parameters and capture physics QA aspects. Optimally developed software helps the physicist in peer review and qualify the physical parameters. Methods: Using the XOFT™ Axxent™ electronic brachytherapy system in conjunction with a cloud-based software, a process was setup to capture and record treatments. It was implemented initially at about 10 sites in California. For dosimetric purposes, the software facilitated storage of the physics parameters of surface applicators used in treatment and other source calibration parameters. In addition, the patient prescription, pathology and other setup considerations were input by radiation oncologist and the therapist. This facilitated physics planning of the treatment parameters and also independent check of the dwell time. From 2013–2014, nearly1500 such calculation were completed by a group of physicists. A total of 800 patients with multiple lesions have been treated successfully during this period. The treatment log files have been uploaded and documented in the software which facilitated physics peer review of treatments per the standards in place by AAPM and ACR. Results: The program model was implemented successfully at multiple sites. The cloud based software allowed for proper peer review and compliance of the program at 10 clinical sites. Dosimtery was done on 800 patients and executed in a timely fashion to suit the clinical needs. Accumulated physics data in the software from the clinics allows for robust analysis and future development. Conclusion: Electronic brachytherapy implementation experience from a quality assurance perspective was greatly enhanced by using a cloud based software. The comprehensive database will pave the way for future developments to yield superior physics outcomes.

  9. Utilization and Outcomes of Breast Brachytherapy in Younger Women

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Grace L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Huo, Jinhai [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hunt, Kelly K. [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-09-01

    Purpose: To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger. Methods and Materials: Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n=3134) or whole-breast irradiation (n=42,750). We stratified patients into risk groups according to age (Age<50 vs Age≥50) and endocrine therapy status (Endocrine− vs Endocrine+). “Endocrine+” patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression. Results: Brachytherapy utilization increased from 2003 to 2010: in patients Age<50, from 0.6% to 4.9%; patients Age≥50 from 2.2% to 11.3%; Endocrine− patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age<50 versus 32% of WBI patients (P<.001); whereas 41% of brachytherapy patients were Endocrine–versus 44% of WBI patients (P=.003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine−/Age<50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine−/Age≥50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age<50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age≥50 (4.2% vs 2

  10. Feasibility and safety of outpatient brachytherapy in 37 patients with brain tumors using the GliaSite Radiation Therapy System.

    Science.gov (United States)

    Chino, Kazumi; Silvain, Daniel; Grace, Ana; Stubbs, James; Stea, Baldassarre

    2008-07-01

    Temporary, low dose rate brachytherapy to the margins of resected brain tumors, using a balloon catheter system (GliaSite Radiation Therapy System) and liquid I-125 radiation source (Iotrex), began in 2002 at the University of Arizona Medical Center. Initially, all patients were treated on an inpatient basis. For patient convenience, we converted to outpatient therapy. In this article we review the exposure data and safety history for the 37 patients treated as outpatients. Proper patient selection and instruction is crucial to having a successful outpatient brachytherapy program. A set of evaluation criteria and patient instructions were developed in compliance with the U.S. Nuclear Regulatory Commission's document NUREG-1556 Volume 9 (Appendix U) and Arizona State Nuclear regulatory guidelines, which specify acceptable exposure rates for outpatient release in this setting. Of the 37 patients monitored, 26 patients were treated for recurrent glioblastoma multiforme (GBM), six for primary GBM, and five for metastatic brain tumors. All 37 patients and their primary caregivers gave signed agreement to follow a specific set of instructions and were released for the duration of brachytherapy (3-7 days). The typical prescription dose was 60 Gy delivered at 0.5 cm from the balloon surface. Afterloaded activities in these patients ranged from 90.9 to 750.0 mCi and measured exposure rates at 1 m from the head were less than 14 mR/h. The mean exposure to the caretaker measured by personal radiation Landauer Luxel + whole body dosimeters for 25 caretakers was found to be 9.6 mR, which was significantly less than the mean calculated exposure of 136.8 mR. For properly selected patients, outpatient brachytherapy is simple and can be performed within established regulatory guidelines.

  11. Fundamental approach to the design of a dose-rate calculation program for use in brachytherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Cassell, K.J. (Saint Luke' s Hospital, Guildford (UK))

    1983-02-01

    A method, developed from the Quantisation Method, of calculating dose-rate distributions around uniformly and non-uniformly loaded brachytherapy sources is described. It allows accurate and straightforward corrections for oblique filtration and self-absorption to be made. Using this method, dose-rate distributions have been calculated for sources of radium 226, gold 198, iridium 192, caesium 137 and cobalt 60, all of which show very good agreement with existing measured and calculated data. This method is now the basis of the Interstitial and Intracavitary Dosimetry (IID) program on the General Electric RT/PLAN computerised treatment planning system.

  12. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science and Engineering Group, San Diego, CA (United States)] [and others

    1995-05-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error.

  13. Combined experimental and Monte Carlo verification of brachytherapy plans for vaginal applicators

    Science.gov (United States)

    Sloboda, Ron S.; Wang, Ruqing

    1998-12-01

    Dose rates in a phantom around a shielded and an unshielded vaginal applicator containing Selectron low-dose-rate sources were determined by experiment and Monte Carlo simulation. Measurements were performed with thermoluminescent dosimeters in a white polystyrene phantom using an experimental protocol geared for precision. Calculations for the same set-up were done using a version of the EGS4 Monte Carlo code system modified for brachytherapy applications into which a new combinatorial geometry package developed by Bielajew was recently incorporated. Measured dose rates agree with Monte Carlo estimates to within 5% (1 SD) for the unshielded applicator, while highlighting some experimental uncertainties for the shielded applicator. Monte Carlo calculations were also done to determine a value for the effective transmission of the shield required for clinical treatment planning, and to estimate the dose rate in water at points in axial and sagittal planes transecting the shielded applicator. Comparison with dose rates generated by the planning system indicates that agreement is better than 5% (1 SD) at most positions. The precision thermoluminescent dosimetry protocol and modified Monte Carlo code are effective complementary tools for brachytherapy applicator dosimetry.

  14. SU-E-T-635: Process Mapping of Eye Plaque Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, J; Kim, Y [University of Arizona, Tucson, AZ (United States)

    2015-06-15

    Purpose: To apply a risk-based assessment and analysis technique (AAPM TG 100) to eye plaque brachytherapy treatment of ocular melanoma. Methods: The role and responsibility of personnel involved in the eye plaque brachytherapy is defined for retinal specialist, radiation oncologist, nurse and medical physicist. The entire procedure was examined carefully. First, major processes were identified and then details for each major process were followed. Results: Seventy-one total potential modes were identified. Eight major processes (corresponding detailed number of modes) are patient consultation (2 modes), pretreatment tumor localization (11), treatment planning (13), seed ordering and calibration (10), eye plaque assembly (10), implantation (11), removal (11), and deconstruction (3), respectively. Half of the total modes (36 modes) are related to physicist while physicist is not involved in processes such as during the actual procedure of suturing and removing the plaque. Conclusion: Not only can failure modes arise from physicist-related procedures such as treatment planning and source activity calibration, but it can also exist in more clinical procedures by other medical staff. The improvement of the accurate communication for non-physicist-related clinical procedures could potentially be an approach to prevent human errors. More rigorous physics double check would reduce the error for physicist-related procedures. Eventually, based on this detailed process map, failure mode and effect analysis (FMEA) will identify top tiers of modes by ranking all possible modes with risk priority number (RPN). For those high risk modes, fault tree analysis (FTA) will provide possible preventive action plans.

  15. A newly developed MR simulation system for intracavitary brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ebe, Kazuyu; Matsunaga, Naofumi [Yamaguchi Univ., Ube (Japan). School of Medicine

    1997-03-01

    We have developed a prototype system for a magnetic resonance (MR) simulation to accurately estimate radiation doses to the tumor and surrounding normal tissues during brachytherapy for cervical cancer. Six patients with cervical cancer underwent MR simulation prior to intracavitary high-dose-rate brachytherapy using Co-60 sources. Tandem and ovoid applicators filled with tap-water were placed in the uterine cavity and vaginal fornix, then MR imaging examinations were performed. Frontal and lateral images of maximum intensity projection (MIP) of applicators generated from a data set of half-Fourier single shot turbo spin-echo (HASTE) images were chosen for processing by the treatment planning computer system. Then, isodose curves on the coronal or sagittal plane of the tandem section were superimposed on corresponding T2-weighted images derived from a turbo spin-echo technique. Doses to the tumor, the posterior wall of the urinary bladder, the anterior wall of the rectum, and the urethra were read from isodose curves superimposed on the T2-weighted sagittal image. Phantom experiments were done to evaluate geometrical errors. The possible distortion of the lattice image on the phantom was small. This system promises to be useful in customizing the dose distribution corresponding to the tumor and surrounding normal tissues. (author)

  16. Dosimetry on ocular brachytherapy with I-125 ophthalmologic ROPES and COMS plaques

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, Arnaldo P. [Centro Federal de Educacao Tecnoloica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar], e-mail: aprata@des.cefetmg.br; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares], e-mail: campos@nuclear.ufmg.br

    2009-07-01

    Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for departuring absorbed doses in tumor minimizing doses in the lens and the adjacent tissues of the eyeball (orbital region), avoiding deleterious effects. Thus, a three-dimensional computational voxel model and an analytical model were coupled, including the heterogeneous properties of the globe and the adjacent tissues. The analytical model was applied to define the thin structures of the ocular globe. This computational model is used to simulate orbital irradiation with ROPES and COMS ophthalmologic plaques placed on the sclera surface filled to ten and eight iodine-125 seeds, respectively. Simulations are performed on the MCNP5 code. The computational simulation allows evaluating how the dose rates are spatially distributed in the orbital volume. The results are normalized to 100% at the maximum dose on the tumor base, and by the applied source activity. The external globe structures receive 0.5% of the maximum internal dose. The crystalline lens dosimetry depends on the position and thickness of the tumor and the plaque diameters. On the present case, 12.75% of maximum dose is found on the lens. The maximum dose is found onto the eyeball, in the vitreous. The present model represents an advance in simulating and predicting absorbed dose on ocular brachytherapy, incorporating anthropomorphic and anthropometric features of the real eyeball. (author)

  17. Brachytherapy on restenosis. {sup 32}P radioisotope in animal model

    Energy Technology Data Exchange (ETDEWEB)

    Bergoc, R.; Rivera, E.; Cocca, C.; Martin, G.; Cricco, G. [Buenos Aires Univ. (Argentina). School of Pharmacy and Biochemistry; Croci, M.; Guzman, L.

    2000-05-01

    Despite a notorious decline in age-adjusted death rates for cardiovascular pathologies, coronary artery disease still remains as the main cause of mortality above the age of 40 in men and 60 in women. More than 25% of death in persons over the age of 35 are due to coronary disease. In about 50% of men and 30% of women, the first manifestation of the disease is an acute myocardial infarction and 10% a sudden cardiac death. In Argentina it is estimated that in 1998 about 100.000-115.000 people suffered as first manifestation of coronary illness a myocardial acute infarct. Angioplasty has an important and well established site in the treatment of the coronary illness and restenosis represents the principal complication of this method for myocardial re-vascularization. About a 35-40% of treated arteries present restenosis within the first six month the intervention with the concomitant need of re-interventions, re-hospitalizations, by-pass surgery, work discontinuity and the high cost for the health system. A number of drugs were tested as anti-restenosis: anticoagulants, aspirin, antispasmodics and lipid-lowering agents but none was clearly efficient; also, experimental studies in which intravascular irradiation with different source types and energies, radiation doses and doses rate to prevent restenosis was utilized; however, there is no consensus in many aspects of this intravascular brachytherapy. The first step in this work was to induce the experimental model in rabbits. Afterwards, by means of the balloon methodology and stent implantation, brachytherapy experiments were carried out to evaluate the biological effect on different layers of arteries, with different Doses using a beta particle emitting radioisotope ({sup 32}P). The arteriosclerotic lesions were induced in New Zealand rabbits through the administration of a diet with high cholesterol content. Angioplastic interventions on femoral arteries were done with balloon methodology and controlled by

  18. Epimacular brachytherapy for wet AMD: current perspectives.

    Science.gov (United States)

    Casaroli-Marano, Ricardo P; Alforja, Socorro; Giralt, Joan; Farah, Michel E

    2014-01-01

    Age-related macular degeneration (AMD) is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic) and wet (neovascular or exudative). Geographic atrophy accounts for approximately 85%-90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT) seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD.

  19. Experiences of high dose rate interstitial brachytherapy for carcinoma of the mobile tongue

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Hiroshi; Inoue, Toshihiko; Yamazaki, Hideya (Osaka Univ. (Japan). Faculty of Medicine) (and others)

    1994-03-01

    Interstitial brachytherapy was conducted for mobile tongue carcinoma using a high dose rate remote afterloading machine with small [sup 192]I source. Detailed method, named as 'linked double-botton technique', is to approach from submandibular skin by an open-ended stainless steel needles to the tongue lesion, and to replace each needle into flexible nylon tube from the oral cavity. Delivered dose was 60 Gy/10 Fr./5-6 days at the distance 5 mm from the source plane. Ten patients with mobile tongue carcinoma Tl-2N0 were treated with this method from October 1991 through August 1992. Local was uncontrolled in one patient, in whom the lesion was combined with leukoplakia at both lateral borders of the tongue. This was in accordance with the result in low dose rate treatment. This can be a substitute to low dose rate system for treatment of mobile tongue carcinoma. (author).

  20. Monte Carol-Based Dosimetry of Beta-Emitters for Intravascular Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, C.K.

    2002-06-25

    Monte Carlo simulations for radiation dosimetry and the experimental verifications of the simulations have been developed for the treatment geometry of intravascular brachytherapy, a form of radionuclide therapy for occluded coronary disease (restenosis). Monte Carlo code, MCNP4C, has been used to calculate the radiation dose from the encapsulated array of B-emitting seeds (Sr/Y-source train). Solid water phantoms have been fabricated to measure the dose on the radiochromic films that were exposed to the beta source train for both linear and curved coronary vessel geometries. While the dose difference for the 5-degree curved vessel at the prescription point of f+2.0 mm is within the 10% guideline set by the AAPM, however, the difference increased dramatically to 16.85% for the 10-degree case which requires additional adjustment for the acceptable dosimetry planning. The experimental dose measurements agree well with the simulation results

  1. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  2. Posttraumatic Stress Disorder After High-Dose-Rate Brachytherapy for Cervical Cancer With 2 Fractions in 1 Application Under Spinal/Epidural Anesthesia: Incidence and Risk Factors

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, Kathrin, E-mail: kathrin.kirchheiner@meduniwien.ac.at [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria); Czajka-Pepl, Agnieszka [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Ponocny-Seliger, Elisabeth [Department of Psychology, Sigmund Freud Private University Vienna, Vienna (Austria); Scharbert, Gisela; Wetzel, Léonore [Department of Anaesthesia, General Intensive Care and Pain Management, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Nout, Remi A. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Sturdza, Alina [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Dimopoulos, Johannes C. [Metropolitan Hospital, Athens (Greece); Dörr, Wolfgang; Pötter, Richard [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria)

    2014-06-01

    Purpose: To investigate the psychological consequences of high-dose-rate brachytherapy with 2 fractions in 1 application under spinal/epidural anesthesia in the treatment of locally advanced cervical cancer. Methods and Materials: In 50 patients with locally advanced cervical cancer, validated questionnaires were used for prospective assessment of acute and posttraumatic stress disorder (ASD/PTSD) (Impact of Event Scale–Revision), anxiety/depression (Hospital Anxiety and Depression Scale), quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30/Cervical Cancer 24), physical functioning (World Health Organization performance status), and pain (visual analogue scale), before and during treatment and 1 week and 3 months after treatment. Qualitative interviews were recorded in open format for content analysis. Results: Symptoms of ASD occurred in 30% of patients 1 week after treatment; and of PTSD in 41% 3 months after treatment in association with this specific brachytherapy procedure. Pretreatment predictive variables explain 82% of the variance of PTSD symptoms. Helpful experiences were the support of the treatment team, psychological support, and a positive attitude. Stressful factors were pain, organizational problems during treatment, and immobility between brachytherapy fractions. Conclusions: The specific brachytherapy procedure, as performed in the investigated mono-institutional setting with 2 fractions in 1 application under spinal/epidural anesthesia, bears a considerable risk of traumatization. The source of stress seems to be not the brachytherapy application itself but the maintenance of the applicator under epidural anesthesia in the time between fractions. Patients at risk may be identified before treatment, to offer targeted psycho-social support. The patients' open reports regarding helpful experiences are an encouraging feedback for the treatment team; the reported stressful

  3. History of dose specification in Brachytherapy: From Threshold Erythema Dose to Computational Dosimetry

    Science.gov (United States)

    Williamson, Jeffrey F.

    2006-09-01

    This paper briefly reviews the evolution of brachytherapy dosimetry from 1900 to the present. Dosimetric practices in brachytherapy fall into three distinct eras: During the era of biological dosimetry (1900-1938), radium pioneers could only specify Ra-226 and Rn-222 implants in terms of the mass of radium encapsulated within the implanted sources. Due to the high energy of its emitted gamma rays and the long range of its secondary electrons in air, free-air chambers could not be used to quantify the output of Ra-226 sources in terms of exposure. Biological dosimetry, most prominently the threshold erythema dose, gained currency as a means of intercomparing radium treatments with exposure-calibrated orthovoltage x-ray units. The classical dosimetry era (1940-1980) began with successful exposure standardization of Ra-226 sources by Bragg-Gray cavity chambers. Classical dose-computation algorithms, based upon 1-D buildup factor measurements and point-source superposition computational algorithms, were able to accommodate artificial radionuclides such as Co-60, Ir-192, and Cs-137. The quantitative dosimetry era (1980- ) arose in response to the increasing utilization of low energy K-capture radionuclides such as I-125 and Pd-103 for which classical approaches could not be expected to estimate accurate correct doses. This led to intensive development of both experimental (largely TLD-100 dosimetry) and Monte Carlo dosimetry techniques along with more accurate air-kerma strength standards. As a result of extensive benchmarking and intercomparison of these different methods, single-seed low-energy radionuclide dose distributions are now known with a total uncertainty of 3%-5%.

  4. Verification of dosimetry planning in brachytherapy in format Dicom and EUD calculation of Risk in bodies; Verificacion de la planificacion dosimetria en braquiterapia en formato Dicom y calculo del EUD en organos de riesgo

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Hernandez, M. J.; Sendon del Rio, J. R.; Ayala Lazaro, R.; Jimenez Rojas, M. R.; Gomez Cores, S.; Polo Cezon, R.; Lopez Bote, M. A.

    2013-07-01

    This work Describes a program that automates the verification of the schedules in brachytherapy (configuration and dosimetric treatment parameters) for sources of Ir-192 (mHDR v2) and Co-60 (Co0.A86) from the plan exported in DICOM format data. (Author)

  5. Calculation Monte Carlo equivalent dose to organs in a treatment of prostate with Brachytherapy of high rate; Calculo Monte Carlo de dosis equivalente a organos en un tratamiento de prostata con braquiterapia de alta tasa

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C.; Vijande, J.; Granero, D.; Ballester, F.; Perez-Calatayud, J.; Rivard, M. J.

    2013-07-01

    The objective of this study was to obtain equivalent dose to radiosensitive organs when applies brachytherapy high dose (HDR) with sources of 60 Co or 192 Go to a localized carcinoma of the prostate. The results are compared with those reported in the literature on treatment with protons and intensity modulated (IMRT) radiation therapy. (Author)

  6. Initial application of digital tomosynthesis to improve brachytherapy treatment planning

    Science.gov (United States)

    Baydush, Alan H.; Mirzaei McKee, Mahta; King, June; Godfrey, Devon J.

    2007-03-01

    We present preliminary investigations that examine the feasibility of incorporating volumetric images generated using digital tomosynthesis into brachytherapy treatment planning. The Integrated Brachytherapy Unit (IBU) at our facility consists of an L-arm, C-arm isocentric motion system with an x-ray tube and fluoroscopic imager attached. Clinically, this unit is used to generate oblique, anterior-posterior, and lateral images for simple treatment planning and dose prescriptions. Oncologists would strongly prefer to have volumetric data to better determine three dimensional dose distributions (dose-volume histograms) to the target area and organs at risk. Moving the patient back and forth to CT causes undo stress on the patient, allows extensive motion of organs and treatment applicators, and adds additional time to patient treatment. We propose to use the IBU imaging system with digital tomosynthesis to generate volumetric patient data, which can be used for improving treatment planning and overall reducing treatment time. Initial image data sets will be acquired over a limited arc of a human-like phantom composed of real bones and tissue equivalent material. A brachytherapy applicator will be incorporated into one of the phantoms for visualization purposes. Digital tomosynthesis will be used to generate a volumetric image of this phantom setup. This volumetric image set will be visually inspected to determine the feasibility of future incorporation of these types of images into brachytherapy treatment planning. We conclude that initial images using the tomosynthesis reconstruction technique show much promise and bode well for future work.

  7. Electromagnetic tracking for treatment verification in interstitial brachytherapy

    DEFF Research Database (Denmark)

    Bert, Christoph; Kellermeier, Markus; Tanderup, Kari

    2016-01-01

    Electromagnetic tracking (EMT) is used in several medical fields to determine the position and orientation of dedicated sensors, e.g., attached to surgical tools. Recently, EMT has been introduced to brachytherapy for implant reconstruction and error detection. The manuscript briefly summarizes...

  8. Photoacoustic imaging of prostate brachytherapy seeds in ex vivo prostate

    Science.gov (United States)

    Kuo, Nathanael; Kang, Hyun Jae; DeJournett, Travis; Spicer, James; Boctor, Emad

    2011-03-01

    The localization of brachytherapy seeds in relation to the prostate is a key step in intraoperative treatment planning (ITP) for improving outcomes in prostate cancer patients treated with low dose rate prostate brachytherapy. Transrectal ultrasound (TRUS) has traditionally been the modality of choice to guide the prostate brachytherapy procedure due to its relatively low cost and apparent ease of use. However, TRUS is unable to visualize seeds well, precluding ITP and producing suboptimal results. While other modalities such as X-ray and magnetic resonance imaging have been investigated to localize seeds in relation to the prostate, photoacoustic imaging has become an emerging and promising modality to solve this challenge. Moreover, photoacoustic imaging may be more practical in the clinical setting compared to other methods since it adds little additional equipment to the ultrasound system already adopted in procedure today, reducing cost and simplifying engineering steps. In this paper, we demonstrate the latest efforts of localizing prostate brachytherapy seeds using photoacoustic imaging, including visualization of multiple seeds in actual prostate tissue. Although there are still several challenges to be met before photoacoustic imaging can be used in the operating room, we are pleased to present the current progress in this effort.

  9. In vivo dosimetry: trends and prospects for brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher, Gustavo; Rosenfeld, A.; Beddar, S.

    2014-01-01

    The error types during brachytherapy (BT) treatments and their occurrence rates are not well known. The limited knowledge is partly attributed to the lack of independent verification systems of the treatment progression in the clinical workflow routine. Within the field of in vivo dosimetry (IVD)...

  10. Remote Afterloading High Dose Rate Brachytherapy AMC EXPERIANCES

    Energy Technology Data Exchange (ETDEWEB)

    Park, Su Gyong; Chang, Hye Sook; Choi, Eun Kyong; Yi, Byong Yong [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1992-12-15

    Remote afterloading high dose rate brachytherapy(HDRB) is a new technology and needs new biological principle for time and dose schedule. Here, authors attempt to evaluate the technique and clinical outcome in 116 patients, 590 procedures performed at Asan Medical Center for 3 years. From Sep. 1985 to Aug 1992, 471 procedures of intracavitary radiation in 55 patients of cervical cancer and 26 of nasopharyngeal cancer, 79 intraluminal radiation in 12 of esophageal cancer, 11 of endobronchial cancer and 1 Klatskin tumor and 40 interstitial brachytherapy in 4 of breast cancer, 1 sarcoma and 1 urethral cancer were performed. Median follow-up was 7 months with range 1-31 months. All procedures except interstitial were performed under the local anesthesia and they were all well tolerated and completed the planned therapy except 6 patients. 53/58 patients with cervical cancer and 22/26 patients with nasopharynx cancer achieved CR. Among 15 patients with palliative therapy, 80% achieves palliation. We will describe the details of the technique and results in the text. To evaluate biologic effects of HDRB and optimal time/dose/fractionation schedule, we need longer follow-up. But authors feel that HDRB with proper fractionation schedule may yield superior results compared to the low dose rate brachytherapy considering the advantages of HDRB in safety factor for operator, better control of radiation dose and volume and patients comfort over the low dose brachytherapy.

  11. Brachytherapy treatment planning algorithm applied to prostate cancer

    Science.gov (United States)

    Herrera-Rodríguez, M. R.; Martínez-Dávalos, A.

    2000-10-01

    An application of Genetic Algorithms (GAs) for treatment planning optimization in prostate brachytherapy is presented. The importance of multi-objective selection criteria based on the contour of the volume of interest and radiosensitive structures such as the rectum and urethra is discussed. First results are obtained for a simple test case which presents radial symmetry.

  12. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Samia de Freitas, E-mail: samiabrandao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-06-15

    Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively, on the healthy tissue, on the balloon periphery and on the /{sub 1} and /{sub 2} tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively on the healthy tissue, on the target tumor and on the /{sub 1} and /{sub 2} infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

  13. Epimacular brachytherapy for wet AMD: current perspectives

    Directory of Open Access Journals (Sweden)

    Casaroli-Marano RP

    2014-08-01

    Full Text Available Ricardo P Casaroli-Marano,1,2 Socorro Alforja,1 Joan Giralt,1 Michel E Farah2 1Instituto Clínic de Oftalmología (Hospital Clínic de Barcelona, University of Barcelona, Barcelona, Spain; 2Department of Ophthalmology and Visual Sciences, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, Sao Paulo, Brazil Abstract: Age-related macular degeneration (AMD is considered the most common cause of blindness in the over-60 age group in developed countries. There are basically two forms of presentation: geographic (dry or atrophic and wet (neovascular or exudative. Geographic atrophy accounts for approximately 85%–90% of ophthalmic frames and leads to a progressive degeneration of the retinal pigment epithelium and the photoreceptors. Wet AMD causes the highest percentage of central vision loss secondary to disease. This neovascular form involves an angiogenic process in which newly formed choroidal vessels invade the macular area. Today, intravitreal anti-angiogenic drugs attempt to block the angiogenic events and represent a major advance in the treatment of wet AMD. Currently, combination therapy for wet AMD includes different forms of radiation delivery. Epimacular brachytherapy (EMBT seems to be a useful approach to be associated with current anti-vascular endothelial growth factor agents, presenting an acceptable efficacy and safety profile. However, at the present stage of research, the results of the clinical trials carried out to date are insufficient to justify extending routine use of EMBT for the treatment of wet AMD. Keywords: macular degeneration, radiation, vascular endothelial growth factor, combined therapy, intravitreal therapy, vitrectomy

  14. Progress on system for applying simultaneous heat and brachytherapy to large-area surface disease (Invited Paper)

    Science.gov (United States)

    Stauffer, Paul R.; Schlorff, Jaime L.; Juang, Titania; Neuman, Daniel G., Jr.; Johnson, Jessi E.; Maccarini, Paolo F.; Pouliot, Jean

    2005-04-01

    Laboratory experiments have shown that thermal enhancement of radiation response increases substantially for higher thermal dose (approaching 100 CEM43) and when hyperthermia and radiation are delivered simultaneously. Unfortunately, equipment capable of delivering uniform doses of heat and radiation simultaneously has not been available to test the clinical potential of this approach. We present recent progress on the clinical implementation of a system that combines the uniform heating capabilities of flexible printed circuit board microwave array applicators with an array of brachytherapy catheters held a fixed distance from the skin for uniform radiation of tissue deep with a scanning high dose rate (HDR) brachytherapy source. The system is based on the Combination Applicator which consists of an array of up to 32 Dual Concentric Conductor (DCC) apertures driven at 915 MHz for heating tissue, coupled with an array of 1 cm spaced catheters for HDR therapy. Efforts to optimize the clinical interface and move from rectangular to more complex shape applicators that accommodate the entire disease in a larger number of patients are described. Improvements to the system for powering and controlling the applicator are also described. Radiation dosimetry and experimental performance results of a prototype 15 x 15 cm dual-purpose applicator demonstrate dose distributions with good homogeneity under large contoured surfaces typical of diffuse chestwall recurrence of breast carcinoma. Investigations of potential interaction between heat and brachytherapy components of a Combination Applicator demonstrate no perceptible perturbation of the heating field from an HDR source or leadwire, no perceptible effect of a scanning HDR source on fiberoptic thermometry, and heat and radiation simultaneously for maximum synergism of modalities, this dual therapy system should expand the number of patients that can benefit from effective thermoradiotherapy treatments.

  15. Design and Implementation of a Complementary Treatment Planning Software for the GZP6 HDR Brachytherapy System (GZP6 CTPS

    Directory of Open Access Journals (Sweden)

    Sanaz Hariri Tabrizi

    2011-03-01

    Full Text Available Introduction: Brachytherapy is one of the most common treatment modalities for gynecological cancer. The GZP6 brachytherapy system is one of the devices utilized in Iran. It has been considered particularly due to its low cost compared to other more complete and established systems. This system has some deficiencies including lack of a treatment planning software for non-predefined treatments, inability to change the gradually changeable dosimetric variables and using a point source estimation in dose calculation. This report presents a complementary treatment planning software (CTPS to the system’s own dedicated program. Material and Methods: First, the dosimetric characteristics of three GZP6 sources were calculated based on the TG-43 protocol using the MCNP4C Monte Carlo code. Then, the calculated dose distribution around the implanted applicators, based on the selected dwell positions and dwell times, was shown in a graphical user interface (GUI written using the MATLAB software. Results: The computation uncertainty in the resulting TG-43 parameters was about 1% and the calculated parameters were in good agreement with similar studies on cobalt-60 source dosimetry. Furthermore, the GUI is prepared as a user-friendly executable file which can be installed on any operating system. Discussion and Conclusion: Since different patients have distinct anatomy and physical conditions, a program for non-predefined situations of source arrangement is necessary. Using GZP6 CTPS can satisfy this requirement.

  16. A study of optimization techniques in HDR brachytherapy for the prostate

    Science.gov (United States)

    Pokharel, Ghana Shyam

    Several studies carried out thus far are in favor of dose escalation to the prostate gland to have better local control of the disease. But optimal way of delivery of higher doses of radiation therapy to the prostate without hurting neighboring critical structures is still debatable. In this study, we proposed that real time high dose rate (HDR) brachytherapy with highly efficient and effective optimization could be an alternative means of precise delivery of such higher doses. This approach of delivery eliminates the critical issues such as treatment setup uncertainties and target localization as in external beam radiation therapy. Likewise, dosimetry in HDR brachytherapy is not influenced by organ edema and potential source migration as in permanent interstitial implants. Moreover, the recent report of radiobiological parameters further strengthen the argument of using hypofractionated HDR brachytherapy for the management of prostate cancer. Firstly, we studied the essential features and requirements of real time HDR brachytherapy treatment planning system. Automating catheter reconstruction with fast editing tools, fast yet accurate dose engine, robust and fast optimization and evaluation engine are some of the essential requirements for such procedures. Moreover, in most of the cases we performed, treatment plan optimization took significant amount of time of overall procedure. So, making treatment plan optimization automatic or semi-automatic with sufficient speed and accuracy was the goal of the remaining part of the project. Secondly, we studied the role of optimization function and constraints in overall quality of optimized plan. We have studied the gradient based deterministic algorithm with dose volume histogram (DVH) and more conventional variance based objective functions for optimization. In this optimization strategy, the relative weight of particular objective in aggregate objective function signifies its importance with respect to other objectives

  17. A study on room design and radiation safety around room for Co-60 after loading HDR brachytherapy unit converted from room for Ir-192 after loading HDR brachytherapy unit

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2015-01-01

    Full Text Available Context: Use of Co-60 source in place of Ir-192 in high dose rate brachytherapy unit (HDR unit has come for discussion in recent publications. Co-60 based system has been advocated for centers which have fewer brachytherapy procedures as it has comparative economically and administrative advantage. This study has direct practical application for such institutions, which are at the cusp of moving from Ir-192 to Co-60 based brachytherapy. Aims: Conversion of Ir-192 HDR room to Co-60 HDR room and to analyze radiation safety around the room. Materials and Methods: Uniform thickness of 15 cm concrete was added to all walls (except one wall adjoining to linear accelerator bunker to convert existing room forIr-192 HDR unit to suitable room for Co-60 HDR unit. Radiation survey around room was done. Actual and calculated wall thicknesses were compared. Results: Radiation survey data indicates that modified room is suitable for Co-60 HDR unit and all values are in full conformity to annual dose limits mentioned in Safety Code for Radiation Therapy Sources (SCRTS, Atomic Energy Regulatory Body (AERB; the regulatory body in India. Also, modified wall thicknesses are appropriate for annual design dose limits mentioned in Safety Report Series No. 47 of International Atomic Energy Agency (IAEA. However, console wall thickness (0.45 m is less than the calculated thickness (0.53 m for instantaneous dose rate (IDR design dose limit (7.5 ΅Sv/h as perabove safety report of IAEA. Conclusions: The modified wall thicknesses are appropriate for annual design dose limits. However, console wall thickness is less than the required thickness for IDR design dose limit. It has been suggested to add 2.64 cm steel on console wall. It has been found that design dose limits should be considered while making room layout plan and regulatory body should add these constraints inSCRTS.

  18. Influence of metal of the applicator on the dose distribution during brachytherapy.

    Science.gov (United States)

    Wu, Chin-Hui; Shiau, An-Cheng; Liao, Yi-Jen; Lin, Hsin-Yu; Liu, Yen-Wan Hsueh; Hsu, Shih-Ming

    2014-01-01

    This study explores how the metal materials of the applicator influence the dose distribution when performing brachytherapy for cervical cancer. A pinpoint ionization chamber, Monte Carlo code MCNPX, and treatment planning system are used to evaluate the dose distribution for a single Ir-192 source positioned in the tandem and ovoid. For dose distribution in water with the presence of the tandem, differences among measurement, MCNPX calculation and treatment planning system results are MCNPX result agrees with the measurement. But the doses calculated from treatment planning system are overestimated by up to a factor of 4. This is due to the shielding effect of the metal materials in the applicator not being considered in the treatment planning system. This result suggests that the treatment planning system should take into account corrections for the metal materials of the applicator in order to improve the accuracy of the radiation dose delivered.

  19. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G [Laboratory for Percutaneous Surgery, School of Computing, Queen' s University, Kingston, Ontario (Canada); Joshi, C P; Falkson, C; Schreiner, L John [CCSEO, Kingston General Hospital and Department of Oncology, Queen' s University, Kingston, Ontario (Canada)

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  20. Nanoparticle-Based Brachytherapy Spacers for Delivery of Localized Combined Chemoradiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajiv, E-mail: r.kumar@neu.edu [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Belz, Jodi [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Markovic, Stacey [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Jadhav, Tej; Fowle, William [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Niedre, Mark [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Cormack, Robert; Makrigiorgos, Mike G. [Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Sridhar, Srinivas [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States)

    2015-02-01

    Purpose: In radiation therapy (RT), brachytherapy-inert source spacers are commonly used in clinical practice to achieve high spatial accuracy. These implanted devices are critical technical components of precise radiation delivery but provide no direct therapeutic benefits. Methods and Materials: Here we have fabricated implantable nanoplatforms or chemoradiation therapy (INCeRT) spacers loaded with silica nanoparticles (SNPs) conjugated containing a drug, to act as a slow-release drug depot for simultaneous localized chemoradiation therapy. The spacers are made of poly(lactic-co-glycolic) acid (PLGA) as matrix and are physically identical in size to the commercially available brachytherapy spacers (5 mm × 0.8 mm). The silica nanoparticles, 250 nm in diameter, were conjugated with near infrared fluorophore Cy7.5 as a model drug, and the INCeRT spacers were characterized in terms of size, morphology, and composition using different instrumentation techniques. The spacers were further doped with an anticancer drug, docetaxel. We evaluated the in vivo stability, biocompatibility, and biodegradation of these spacers in live mouse tissues. Results: The electron microscopy studies showed that nanoparticles were distributed throughout the spacers. These INCeRT spacers remained stable and can be tracked by the use of optical fluorescence. In vivo optical imaging studies showed a slow diffusion of nanoparticles from the spacer to the adjacent tissue in contrast to the control Cy7.5-PLGA spacer, which showed rapid disintegration in a few days with a burst release of Cy7.5. The docetaxel spacers showed suppression of tumor growth in contrast to control mice over 16 days. Conclusions: The imaging with the Cy7.5 spacer and therapeutic efficacy with docetaxel spacers supports the hypothesis that INCeRT spacers can be used for delivering the drugs in a slow, sustained manner in conjunction with brachytherapy, in contrast to the rapid clearance of the drugs when

  1. Sources

    OpenAIRE

    2015-01-01

    SOURCES MANUSCRITES Archives nationales Rôles de taille 1768/71 Z1G-344/18 Aulnay Z1G-343a/02 Gennevilliers Z1G-340/01 Ivry Z1G-340/05 Orly Z1G-334c/09 Saint-Remy-lès-Chevreuse Z1G-344/18 Sevran Z1G-340/05 Thiais 1779/80 Z1G-391a/18 Aulnay Z1G-380/02 Gennevilliers Z1G-385/01 Ivry Z1G-387b/05 Orly Z1G-388a/09 Saint-Remy-lès-Chevreuse Z1G-391a/18 Sevran Z1G-387b/05 Thiais 1788/89 Z1G-451/18 Aulnay Z1G-452/21 Chennevières Z1G-443b/02 Gennevilliers Z1G-440a/01 Ivry Z1G-452/17 Noiseau Z1G-445b/05 ...

  2. Collision-kerma conversion between dose-to-tissue and dose-to-water by photon energy-fluence corrections in low-energy brachytherapy

    Science.gov (United States)

    Giménez-Alventosa, Vicent; Antunes, Paula C. G.; Vijande, Javier; Ballester, Facundo; Pérez-Calatayud, José; Andreo, Pedro

    2017-01-01

    The AAPM TG-43 brachytherapy dosimetry formalism, introduced in 1995, has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations, except in the vicinity of the source capsule. Subsequent dosimetry developments, based on Monte Carlo calculations or analytical solutions of transport equations, do not rely on the CPE assumption and determine directly the dose to different tissues. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seeds is proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences. State-of-the art Monte Carlo calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone), which in all cases include a realistic modelling of low-energy brachytherapy sources in order to benchmark the formalism proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases (e.g. bone tissue).

  3. Biological Shielding Design Effectiveness of the Brachytherapy Unit at the Korle Bu Teaching Hospital in Ghana Using Mcnp5 Monte Carlo Code

    Directory of Open Access Journals (Sweden)

    C.C. Arwui

    2011-05-01

    Full Text Available Design objectives for brachytherapy treatment facilities require sufficient shielding to reduce primary and scatter radiation to design limit in order to limit exposure to patients, staff and the general public. The primary aim of this study is to verify whether shielding of the brachytherapy unit at the Korle Bu teaching Hospital in Ghana provides adequate protection in order to assess any radiological health and safety impact and also test the suitability of other available sources. The study evaluates the effectiveness of the biological shielding design of a Cs-137 brachytherapy unit at the Korle-Bu Teaching Hospital in Ghana using MCNP5. The facility was modeled based on the design specifications for LDR Cs-137, MDR Cs-137, HDR Co-60 and HDR Ir-192 treatment modalities. The estimated dose rate ranged from (0.01-0.15 μSv/h and (0.37-3.05 μSv/h for the existing initial and decayed activities of LDR Cs-137 for the public and controlled areas respectively, (0.03-0.57 μSv/h and (1.53-8.06 μSv/h for MDR Cs-137, (7.47-59.46 μSv/h and (144.87-178.74 μSv/h for HDR Co- 60, (0.13-6.95 μSv/h and (19.47-242.98 μSv/h for HDR Ir-192 for the public and controlled areas respectively. The results were verified by dose rates measurement for the current LDR setup at the Brachytherapy unit and agreed quiet well. It was also compared with the reference values of 0.5 μSv/h for public areas and 7.5 μSv/h for controlled areas respectively. It can be concluded that the shielding is adequate for the existing source.

  4. Review of advanced catheter technologies in radiation oncology brachytherapy procedures.

    Science.gov (United States)

    Zhou, Jun; Zamdborg, Leonid; Sebastian, Evelyn

    2015-01-01

    The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy procedures using magnetic resonance images and electromagnetic tracking. The accuracy of catheter reconstruction, imaging artifacts, and other notable properties of plastic and titanium applicators in gynecologic treatments are reviewed. The accuracy, noise performance, and limitations of electromagnetic tracking for catheter reconstruction are discussed. Several newly developed applicators for accelerated partial breast irradiation and gynecologic treatments are also reviewed. New hypofractionated high dose rate treatment schemes in prostate cancer and accelerated partial breast irradiation are presented.

  5. Brachytherapy seed localization using geometric and linear programming techniques.

    Science.gov (United States)

    Singh, Vikas; Mukherjee, Lopamudra; Xu, Jinhui; Hoffmann, Kenneth R; Dinu, Petru M; Podgorsak, Matthew

    2007-09-01

    We propose an optimization algorithm to solve the brachytherapy seed localization problem in prostate brachytherapy. Our algorithm is based on novel geometric approaches to exploit the special structure of the problem and relies on a number of key observations which help us formulate the optimization problem as a minimization integer program (IP). Our IP model precisely defines the feasibility polyhedron for this problem using a polynomial number of half-spaces; the solution to its corresponding linear program is rounded to yield an integral solution to our task of determining correspondences between seeds in multiple projection images. The algorithm is efficient in theory as well as in practice and performs well on simulation data (approximately 98% accuracy) and real X-ray images (approximately 95% accuracy). We present in detail the underlying ideas and an extensive set of performance evaluations based on our implementation.

  6. Compound dual radiation action theory for 252Cf brachytherapy.

    Science.gov (United States)

    Wang, C K; Zhang, X

    2004-01-01

    The existing dosimetry protocol that uses the concept of RBE for 252Cf brachytherapy contains large uncertainties. A new formula has been developed to correlate the biological effect (i.e. cell survival fraction) resulting from a mixed n + gamma radiation field with two physical quantities and two biological quantities. The formula is based on a pathway model evolved from that of the compound-dual-radiation-action (CDRA) theory, previously proposed by Rossi and Zaider. The new model employs the recently published data on radiation-induced DNA lesions. The new formula is capable of predicting quantitatively the synergistic effect caused by the interactions between neutron events and gamma ray events, and it is intended to be included into a new dosimetry protocol for future 252Cf brachytherapy.

  7. Distortions induced by radioactive seeds into interstitial brachytherapy dose distributions.

    Science.gov (United States)

    Zhou, Chuanyu; Inanc, Feyzi; Modrick, Joseph M

    2004-12-01

    In a previous article, we presented development and verification of an integral transport equation-based deterministic algorithm for computing three-dimensional brachytherapy dose distributions. Recently, we have included fluorescence radiation physics and parallel computation to the standing algorithms so that we can compute dose distributions for a large set of seeds without resorting to the superposition methods. The introduction of parallel computing capability provided a means to compute the dose distribution for multiple seeds in a simultaneous manner. This provided a way to study strong heterogeneity and shadow effects induced by the presence of multiple seeds in an interstitial brachytherapy implant. This article presents the algorithm for computing fluorescence radiation, algorithm for parallel computing, and display results for an 81-seed implant that has a perfect and imperfect lattice. The dosimetry data for a single model 6711 seeds is presented for verification and heterogeneity factor computations using simultaneous and superposition techniques are presented.

  8. Dose volume analysis in brachytherapy and stereotactic radiosurgery

    CERN Document Server

    Tozer-Loft, S M

    2000-01-01

    compared with a range of figures of merit which express different aspects of the quality of each dose distributions. The results are analysed in an attempt to answer the question: What are the important features of the dose distribution (conformality, uniformity, etc) which show a definite relationship with the outcome of the treatment? Initial results show positively that, when Gamma Knife radiosurgery is used to treat acoustic neuroma, some measures of conformality seem to have a surprising, but significant association with outcome. A brief introduction to three branches of radiotherapy is given: interstitial brachytherapy, external beam megavoltage radiotherapy, and stereotactic radiosurgery. The current interest in issues around conformity, uniformity and optimisation is explained in the light of technical developments in these fields. A novel method of displaying dose-volume information, which mathematically suppresses the inverse-square law, as first suggested by L.L. Anderson for use in brachytherapy i...

  9. Cataract extraction after brachytherapy for malignant melanoma of the choroid

    Energy Technology Data Exchange (ETDEWEB)

    Fish, G.E.; Jost, B.F.; Snyder, W.I.; Fuller, D.G.; Birch, D.G. (Texas Retina Associates, Dallas (USA))

    1991-05-01

    Thirteen eyes of 55 consecutive patients treated with brachytherapy for malignant melanoma of the choroid developed postirradiation cataracts. Cataract development was more common in older patients and in patients with larger and more anterior tumors. Eleven eyes had extracapsular cataract extraction and intraocular lens implantation. Initial visual improvement occurred in 91% of eyes, with an average improvement of 5.5 lines. Visual acuity was maintained at 20/60 or better in 55% of the eyes over an average period of follow-up of 24 months (range, 6 to 40 months). These data suggest that, visually, cataract extraction can be helpful in selected patients who develop a cataract after brachytherapy for malignant melanoma of the choroid.

  10. 3T MR-Guided Brachytherapy for Gynecologic Malignancies

    CERN Document Server

    Kapur, Tina; Damato, Antonio; Schmidt, Ehud J; Viswanathan, Akila N; 10.1016/j.mri.2012.06.003

    2013-01-01

    Gynecologic malignancies are a leading cause of death in women worldwide. Standard treatment for many primary and recurrent gynecologic cancer cases includes a combination of external beam radiation, followed by brachytherapy. Magnetic Resonance Imaging (MRI) is benefitial in diagnostic evaluation, in mapping the tumor location to tailor radiation dose, and in monitoring the tumor response to treatment. Initial studies of MR-guidance in gynecologic brachtherapy demonstrate the ability to optimize tumor coverage and reduce radiation dose to normal tissues, resulting in improved outcomes for patients. In this article we describe a methodology to aid applicator placement and treatment planning for 3 Tesla (3T) MR-guided brachytherapy that was developed specifically for gynecologic cancers. This has been used in 18 cases to date in the Advanced Multimodality Image Guided Operating suite at Brigham and Women's Hospital. It is comprised of state of the art methods for MR imaging, image analysis, and treatment plann...

  11. Brachytherapy in Lip Carcinoma: Long-Term Results

    Energy Technology Data Exchange (ETDEWEB)

    Guibert, Mireille, E-mail: mireilleguib@voila.fr [Department of Head and Neck Surgery, Larrey Hospital, Toulouse (France); David, Isabelle [Department of Radiation Oncology, Claudius Regaud Institut, Toulouse (France); Vergez, Sebastien [Department of Head and Neck Surgery, Larrey Hospital, Toulouse (France); Rives, Michel [Department of Radiation Oncology, Claudius Regaud Institut, Toulouse (France); Filleron, Thomas [Department of Epidemiology, Claudius Regaud Institut, Toulouse (France); Bonnet, Jacques; Delannes, Martine [Department of Radiation Oncology, Claudius Regaud Institut, Toulouse (France)

    2011-12-01

    Purpose: The aim of this study was to evaluate the effectiveness of low-dose-rate brachytherapy for local control and relapse-free survival in squamous cell and basal cell carcinomas of the lips. We compared two groups: one with tumors on the skin and the other with tumors on the lip. Patients and methods: All patients had been treated at Claudius Regaud Cancer Centre from 1990 to 2008 for squamous cell or basal cell carcinoma. Low-dose-rate brachytherapy was performed with iridium 192 wires according to the Paris system rules. On average, the dose delivered was 65 Gy. Results: 172 consecutive patients were included in our study; 69 had skin carcinoma (squamous cell or basal cell), and 92 had squamous cell mucosal carcinoma. The average follow-up time was 5.4 years. In the skin cancer group, there were five local recurrences and one lymph node recurrence. In the mucosal cancer group, there were ten local recurrences and five lymph node recurrences. The 8-year relapse-free survival for the entire population was 80%. The 8-year relapse-free survival was 85% for skin carcinoma 75% for mucosal carcinoma, with no significant difference between groups. The functional results were satisfactory for 99% of patients, and the cosmetic results were satisfactory for 92%. Maximal toxicity observed was Grade 2. Conclusions: Low-dose-rate brachytherapy can be used to treat lip carcinomas at Stages T1 and T2 as the only treatment with excellent results for local control and relapse-free survival. The benefits of brachytherapy are also cosmetic and functional, with 91% of patients having no side effects.

  12. Image-guided high dose rate endorectal brachytherapy.

    Science.gov (United States)

    Devic, Slobodan; Vuong, Té; Moftah, Belal; Evans, Michael; Podgorsak, Ervin B; Poon, Emily; Verhaegen, Frank

    2007-11-01

    Fractionated high dose rate endorectal brachytherapy (HDR-EBT) using CT-based treatment planning is an alternative method for preoperative down-sizing and down-staging of advanced rectal adeno-carcinomas. The authors present an image guidance procedure that was developed to ensure daily dose reproducibility for the four brachytherapy treatment fractions. Since the applicator might not be placed before each treatment fraction inside the rectal lumen in the same manner as it was placed during the 3D CT volume acquisition used for treatment planning, there is a shift along the catheter axis that may have to be performed. The required shift is determined by comparison of a daily radiograph with the treatment planning digitally-reconstructed radiograph (DRR). A procedure is developed for DRR reconstruction from the 3D data set used for the treatment planning, and two possible daily longitudinal shifts are illustrated: above and below the planning dose distribution. The authors also describe the procedure for rotational alignment illustrated on a clinical case. Reproduction of the treatment planned dose distribution on a daily basis is crucial for the success of fractionated 3D based brachytherapy treatments. Due to the cylindrical symmetry of the applicator used for preoperative HDR-EBT, two types of adjustments are necessary: applicator rotation and dwell position shift along the applicator's longitudinal axis. The impact of the longitudinal applicator shift prior to treatment delivery for 62 patients treated in our institution is also assessed.

  13. A compilation of current regulations, standards and guidelines in remote afterloading brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, J.P.; Simion, G.P.; Kozlowski, S.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-10-01

    Over a dozen government and professional organizations in the United States and Europe have issued regulations and guidance concerning quality management in the practice of remote afterloading brachytherapy. Information from the publications of these organizations was collected and collated for this report. This report provides the brachytherapy licensee access to a broad field of quality management information in a single, topically organized document.

  14. SU-E-T-141: Automated Dose Point Placement for Cervical Cancer Brachytherapy Using Tandem and Ovoid Applicators

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H; Padilla, L; Hasan, Y; Al-Hallaq, H [The University of Chicago, Chicago, IL (United States)

    2015-06-15

    Purpose: To develop a standalone application, which automatically and consistently calculates the coordinates of points A and H based solely on the implanted applicator geometry for cervical cancer HDR brachytherapy. Methods: Manchester point A and ABS point H are both located 2cm lateral from the central tandem plane. While both points are located 2cm above the cervical os, surrogates for the os differ. Point A is defined relative to the anatomical cervical os. Point H is defined relative to the intersection of the tandem with the superior aspects of the ovoids. The application takes an input text file generated by the treatment planning system (TPS, BrachyVision, Varian) that specifies the source geometries. It then outputs the 3D coordinates of points A and H in both the left and right directions. The algorithm was implemented and tested on 34 CT scans of 7 patients treated with HDR brachytherapy delivered using tandem and ovoids. A single experienced user retrospectively and manually placed points A and H on the CT scans, whose coordinates were used as the gold standard for the comparison to the automatically calculated points. Results: The automatically calculated coordinates of points A and H agree within 0.7mm with the gold standard. The averages and standard deviations of the 3D coordinate difference between points placed by the two methods are 0.3±0.1 and 0.4±0.1mm for points A and H, respectively. The maximum difference in 3D magnitude is 0.7mm. Conclusion: The algorithm consistently calculates dose point coordinates independently of the planner for cervical cancer brachytherapy treated with tandem and ovoids. Automated point placement based on the geometry of the implanted applicators agrees in sub-millimeter with careful manual placements by an experienced user. This algorithm expedites the planning process and eliminates dependencies on either user input or TPS visualization tools.

  15. Feasibility study of patient-specific quality assurance system for high-dose-rate brachytherapy in patients with cervical cancer

    Science.gov (United States)

    Lee, Boram; Ahn, Sung Hwan; Kim, Hyeyoung; Han, Youngyih; Huh, Seung Jae; Kim, Jin Sung; Kim, Dong Wook; Sim, Jina; Yoon, Myonggeun

    2016-04-01

    This study was conducted for the purpose of establishing a quality-assurance (QA) system for brachytherapy that can ensure patient-specific QA by enhancing dosimetric accuracy for the patient's therapy plan. To measure the point-absorbed dose and the 2D dose distribution for the patient's therapy plan, we fabricated a solid phantom that allowed for the insertion of an applicator for patient-specific QA and used an ion chamber and a film as measuring devices. The patient treatment plan was exported to the QA dose-calculation software, which calculated the time weight of dwell position stored in the plan DICOM (Digital Imaging and Communications in Medicine) file to obtain an overall beam quality correction factor, and that correction was applied to the dose calculations. Experiments were conducted after importing the patient's treatment planning source data for the fabricated phantom and inserting the applicator, ion chamber, and film into the phantom. On completion of dose delivery, the doses to the ion chamber and film were checked against the corresponding treatment plan to evaluate the dosimetric accuracy. For experimental purposes, five treatment plans were randomly selected. The beam quality correction factors for ovoid and tandem brachytherapy applicators were found to be 1.15 and 1.10 - 1.12, respectively. The beam quality correction factor in tandem fluctuated by approximately 2%, depending on the changes in the dwell position. The doses measured by using the ion chamber showed differences ranging from -2.4% to 0.6%, compared to the planned doses. As for the film, the passing rate was 90% or higher when assessed using a gamma value of the local dose difference of 3% and a distance to agreement of 3 mm. The results show that the self-fabricated phantom was suitable for QA in clinical settings. The proposed patient-specific QA for the treatment planning is expected to contribute to reduce dosimetric errors in brachytherapy and, thus, to enhancing treatment

  16. 3D-printed surface mould applicator for high-dose-rate brachytherapy

    Science.gov (United States)

    Schumacher, Mark; Lasso, Andras; Cumming, Ian; Rankin, Adam; Falkson, Conrad B.; Schreiner, L. John; Joshi, Chandra; Fichtinger, Gabor

    2015-03-01

    In contemporary high-dose-rate brachytherapy treatment of superficial tumors, catheters are placed in a wax mould. The creation of current wax models is a difficult and time consuming proces.The irradiation plan can only be computed post-construction and requires a second CT scan. In case no satisfactory dose plan can be created, the mould is discarded and the process is repeated. The objective of this work was to develop an automated method to replace suboptimal wax moulding. We developed a method to design and manufacture moulds that guarantee to yield satisfactory dosimetry. A 3D-printed mould with channels for the catheters designed from the patient's CT and mounted on a patient-specific thermoplastic mesh mask. The mould planner was implemented as an open-source module in the 3D Slicer platform. Series of test moulds were created to accommodate standard brachytherapy catheters of 1.70mm diameter. A calibration object was used to conclude that tunnels with a diameter of 2.25mm, minimum 12mm radius of curvature, and 1.0mm open channel gave the best fit for this printer/catheter combination. Moulds were created from the CT scan of thermoplastic mesh masks of actual patients. The patient-specific moulds have been visually verified to fit on the thermoplastic meshes. The masks were visually shown to fit onto the thermoplastic meshes, next the resulting dosimetry will have to be compared with treatment plans and dosimetry achieved with conventional wax moulds in order to validate our 3D printed moulds.

  17. Impact of dose rate on clinical course in uveal melanoma after brachytherapy with ruthenium-106

    Energy Technology Data Exchange (ETDEWEB)

    Mossboeck, G.; Rauscher, T.; Langmann, G. [Medical Univ. of Graz (Austria). Dept. of Opthalmology; Winkler, P.; Kapp, K.S. [Medical Univ. of Graz (Austria). Dept. of Therapeutic Radiology and Oncology

    2007-10-15

    Background and Purpose: It has been suggested that the actual dose rate of an irradiating source may be a distinct influencing factor for the biological effect after brachytherapy with ruthenium-106 for uveal melanoma. The purpose of this study was to investigate a hypothesized impact of the dose rate on the clinical and echographic course after brachytherapy. Patients and Methods: In total, 45 patients were included in this retrospective study. According to the actual dose rate, two groups were defined: group 1 with a dose rate < 4 Gy/h and group 2 with a dose rate {>=} 4 Gy/h. Regarding age, tumor height, basal diameter, scleral and apical dose, differences between the groups were not significant. Clinical parameters, including early and late side effects, and echographic courses were compared. Results: A significantly lower metastatic rate was found in group 2. Using univariate Cox proportional hazards regression, only dose rate predicted metastatic spread significantly (p < 0.05), while in a multivariate analysis, using age at the time of treatment, greatest tumor height and greatest basal diameter as covariates, the variable dose rate was of borderline significance (p = 0.077). Patients in group 2 had more early side effects and more pronounced visual decline, but these differences were of borderline significance with p-values of 0.072 and 0.064, respectively. Conclusion: These data suggest that a higher dose rate may confer a lower risk for metastatic spread, but may be associated with more side effects and more pronounced visual decline. (orig.)

  18. Measurement uncertainty analysis of low-dose-rate prostate seed brachytherapy: post-implant dosimetry.

    Science.gov (United States)

    Gregory, Kent J; Pattison, John E; Bibbo, Giovanni

    2015-03-01

    The minimal dose covering 90 % of the prostate volume--D 90--is arguably the most important dosimetric parameter in low-dose-rate prostate seed brachytherapy. In this study an analysis of the measurement uncertainties in D 90 from low-dose-rate prostate seed brachytherapy was conducted for two common treatment procedures with two different post-implant dosimetry methods. The analysis was undertaken in order to determine the magnitude of D 90 uncertainty, how the magnitude of the uncertainty varied when D 90 was calculated using different dosimetry methods, and which factors were the major contributors to the uncertainty. The analysis considered the prostate as being homogeneous and tissue equivalent and made use of published data, as well as original data collected specifically for this analysis, and was performed according to the Guide to the expression of uncertainty in measurement (GUM). It was found that when prostate imaging and seed implantation were conducted in two separate sessions using only CT images for post-implant analysis, the expanded uncertainty in D 90 values were about 25 % at the 95 % confidence interval. When prostate imaging and seed implantation were conducted during a single session using CT and ultrasound images for post-implant analysis, the expanded uncertainty in D 90 values were about 33 %. Methods for reducing these uncertainty levels are discussed. It was found that variations in contouring the target tissue made the largest contribution to D 90 uncertainty, while the uncertainty in seed source strength made only a small contribution. It is important that clinicians appreciate the overall magnitude of D 90 uncertainty and understand the factors that affect it so that clinical decisions are soundly based, and resources are appropriately allocated.

  19. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    Science.gov (United States)

    Balvert, Marleen; Gorissen, Bram L.; den Hertog, Dick; Hoffmann, Aswin L.

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2-5 cc. However, this comes at a cost of a reduction in D90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D90% against uncertainty in dwell positions for both models.

  20. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy.

    Science.gov (United States)

    Afsharpour, H; Landry, G; D'Amours, M; Enger, S; Reniers, B; Poon, E; Carrier, J-F; Verhaegen, F; Beaulieu, L

    2012-06-07

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  1. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qaisieh, Bashar [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Mason, Josh, E-mail: joshua.mason@nhs.net [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Bownes, Peter; Henry, Ann [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Dickinson, Louise [Division of Surgery and Interventional Science, University College London, London (United Kingdom); Department of Radiology, Northwick Park Hospital, London North West NHS Trust, London (United Kingdom); Ahmed, Hashim U. [Division of Surgery and Interventional Science, University College London, London (United Kingdom); University College London Hospital, London (United Kingdom); Emberton, Mark [University College London Hospital, London (United Kingdom); Langley, Stephen [St Luke' s Cancer Centre, Guildford (United Kingdom)

    2015-07-15

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable

  2. Three dimensional intensity modulated brachytherapy (IMBT): Dosimetry algorithm and inverse treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Shi Chengyu; Guo Bingqi; Cheng, Chih-Yao; Esquivel, Carlos; Eng, Tony; Papanikolaou, Niko [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States); Department of Radiation Oncology, Oklahoma University Health Science Center, Oklahoma City, Oklahoma 73104 (United States); Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 (United States)

    2010-07-15

    Purpose: The feasibility of intensity modulated brachytherapy (IMBT) to improve dose conformity for irregularly shaped targets has been previously investigated by researchers by means of using partially shielded sources. However, partial shielding does not fully explore the potential of IMBT. The goal of this study is to introduce the concept of three dimensional (3D) intensity modulated brachytherapy and solve two fundamental issues regarding the application of 3D IMBT treatment planning: The dose calculation algorithm and the inverse treatment planning method. Methods: A 3D IMBT treatment planning system prototype was developed using the MATLAB platform. This system consists of three major components: (1) A comprehensive IMBT source calibration method with dosimetric inputs from Monte Carlo (EGSnrc) simulations; (2) a ''modified TG-43'' (mTG-43) dose calculation formalism for IMBT dosimetry; and (3) a physical constraint based inverse IMBT treatment planning platform utilizing a simulated annealing optimization algorithm. The model S700 Axxent electronic brachytherapy source developed by Xoft, Inc. (Fremont, CA), was simulated in this application. Ten intracavitary accelerated partial breast irradiation (APBI) cases were studied. For each case, an ''isotropic plan'' with only optimized source dwell time and a fully optimized IMBT plan were generated and compared to the original plan in various dosimetric aspects, such as the plan quality, planning, and delivery time. The issue of the mechanical complexity of the IMBT applicator is not addressed in this study. Results: IMBT approaches showed superior plan quality compared to the original plans and the isotropic plans to different extents in all studied cases. An extremely difficult case with a small breast and a small distance to the ribs and skin, the IMBT plan minimized the high dose volume V{sub 200} by 16.1% and 4.8%, respectively, compared to the original and the

  3. Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

    Science.gov (United States)

    Palmer, Antony L.; Lee, Chris; Ratcliffe, Ailsa J.; Bradley, David; Nisbet, Andrew

    2013-10-01

    A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

  4. Automatic analysis of intrinsic positional verification films brachytherapy using MATLAB; Analisis automatico de peliculas de verificacion posicional intrinsica en braqueterapia mediante MATLAB

    Energy Technology Data Exchange (ETDEWEB)

    Quiros Higueras, J. D.; Marco Blancas, N. de; Ruiz Rodriguez, J. C.

    2011-07-01

    One of the essential tests in quality control of brachytherapy equipment is verification auto load intrinsic positional radioactive source. A classic method for evaluation is the use of x-ray film and measuring the distance between the marks left by autoradiography of the source with respect to a reference. In our center has developed an automated method of measurement by the radiochromic film scanning and implementation of a macro developed in Matlab, in order to optimize time and reduce uncertainty in the measurement. The purpose of this paper is to describe the method developed, assess their uncertainty and quantify their advantages over the manual method. (Author)

  5. The Real-Time Dose Measurement Scintillating Fiber Array for Brachytherapy Procedures

    Science.gov (United States)

    Tynes, Lawrence

    2007-03-01

    Brachytherapy is a treatment modality that uses tiny radioactive sources (few mm in length) by delivering enough doses to kill cancer tumors or plaque build-up. The type of sources used in hospitals include both gamma and beta emitters. Presently, the technique suffers from not having a single detector with the capability of providing accurate dose distribution information within sub-mm accuracy. The current standard is based primarily on well chambers and film dosimetry. The Center for Advanced Medical Instrumentation (CAMI) at Hampton University is developing a Scintillating Fiber Based Beta Detector prototype in collaboration with the National Institute for Standards and Technology (NIST) to address this problem. The device is composed of an array of 1x1 mm^2 scintillating fibers optically coupled to photo-multiplier tubes for photon-to-current conversion. A CAMAC LabView based data acquisition system is used for real time data collection and histogramming, data analysis. A set of data were collected at the nearby Bon Secours DePaul Medical Center using a GammaMed 12i HDR after-loader housing a 6.62 mCi Ir-192 source. Preliminary comparison between our device and film dosimetry will be discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ishiyama, Hiromichi, E-mail: hishiyam@kitasato-u.ac.jp [Department of Radiology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan); Nakamura, Ryuji [Department of Radiology, Iwate Medical University, Morioka, Iwate (Japan); Satoh, Takefumi [Department of Urology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan); Tanji, Susumu [Department of Urology, Iwate Medical University, Morioka, Iwate (Japan); Teh, Bin S. [Department of Radiation Oncology, The Methodist Hospital, Houston, TX (United States); Uemae, Mineko [Division of Radiation Oncology, Kitasato University Hospital, Sagamihara, Kanagawa (Japan); Baba, Shiro [Department of Urology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan); Hayakawa, Kazushige [Department of Radiology, Kitasato University School of Medicine, Sagamihara, Kanagawa (Japan)

    2012-04-01

    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.

  7. Three-dimensional brachytherapy optimization techniques in the treatment of patients with cervix cancer; Apport des techniques de curietherapie optimisee grace a l'imagerie tridimensionnelle dans la prise en charge des patientes atteintes d'un cancer du col uterin

    Energy Technology Data Exchange (ETDEWEB)

    Haie-Meder, C.; Mazeron, R.; Verezesan, O.; Monnier, L.; Vieillot, S. [Institut Gustave-Roussy, Service de Curietherapie, 94 - Villejuif (France); Dumas, I. [Institut Gustave-Roussy, Service de Physique, 94 - Villejuif (France); Lhomme, C. [Institut Gustave-Roussy, Service d' Ooncologie Gynecologique, 94 - Villejuif (France); Morice, P. [Institut Gustave-Roussy, Service de Chirurgie Oncologique, 94 - Villejuif (France); Barillot, I. [Centre Regional Universitaire de Cancerologie Henry-S.-Kaplan, Hopital Bretonneau, CHU de Tours, 37 - Tours (France); Universite Francois-Rabelais, 37 - Tours (France)

    2009-10-15

    Traditionally, prescription and treatment planning in intracavitary brachytherapy for cervix cancer have used either reference points (mainly points A and B) or reference isodoses (60 Gy according to ICRU recommendations) to report doses to the target volume. Doses to critical organs were reported at bladder and rectum ICRU points. This practice has been supported by a long-standing clinical experience that has yielded an acceptable therapeutic ratio. The recent development of imaging has contributed to the improvement in target and organs at risk knowledge. In 2005 and 2006, the European group of brachytherapy -European Society for therapeutic radiology and oncology (GEC-E.S.T.R.O.) recommendations publications on 3-D based image brachytherapy have defined the different volumes of interest. These recommendations have been validated with intercomparison delineation studies. With the concomitant development of remote after-loading projectors, provided with miniaturized sources, it is now possible to plan radiation doses by adjusting dwell positions and relative dwell time values. These procedures allow better coverage of the targets while sparing O.A.R.. The recent literature data evidence a significant improvement in local control with no increase in complications. Further studies are needed to better define the dose recommended in both tumour and organs at risk. This is one of the goals of the European study on MRI-guided brachytherapy in locally advanced cervical cancer (E.M.B.R.A.C.E.) protocol (meaning of acronym: an international study on MRI-guided brachytherapy in locally advanced cervical cancer). (authors)

  8. Novel treatment options for nonmelanoma skin cancer: focus on electronic brachytherapy

    Directory of Open Access Journals (Sweden)

    Kasper ME

    2015-11-01

    Full Text Available Michael E Kasper,1,2 Ahmed A Chaudhary3 1Department of Radiation Oncology, Lynn Cancer Institute at Boca Raton Regional Hospital, Boca Raton, 2Charles E. Schmidt College of Medicine, Florida Atlantic University, FL, 3North Main Radiation Oncology, Warren Alpert School of Medicine, Brown University, RI, USA Abstract: Nonmelanoma skin cancer (NMSC is an increasing health care issue in the United States, significantly affecting quality of life and impacting health care costs. Radiotherapy has a long history in the treatment of NMSC. Shortly after the discovery of X-rays and 226Radium, physicians cured patients with NMSC using these new treatments. Both X-ray therapy and brachytherapy have evolved over the years, ultimately delivering higher cure rates and lower toxicity. Electronic brachytherapy for NMSC is based on the technical and clinical data obtained from radionuclide skin surface brachytherapy and the small skin surface applicators developed over the past 25 years. The purpose of this review is to introduce electronic brachytherapy in the context of the history, data, and utilization of traditional radiotherapy and brachytherapy. Keywords: electronic brachytherapy, superficial radiotherapy, skin surface brachytherapy, electron beam therapy, nonmelanoma skin cancer, basal cell carcinoma, squamous cell carcinoma

  9. The transit dose component of high dose rate brachytherapy: Direct measurements and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Bastin, K.T.; Podgorsak, M.B.; Thomadsen, B.R. (Univ. of Wisconsin Hospitals and Clinics, Madison, WI (United States))

    1993-07-15

    The purpose was to measure the transit dose produced by a moving high dose rate brachytherapy source and assess its clinical significance. The doses produced from source movement during Ir-192 HDR afterloading were measured using calibrated thermoluminescent dosimeter rods. Transit doses at distances of 0.5-4.0 cm from an endobronchial applicator were measured using a Lucite phantom accommodating 1 x 1 x 6 mm thermoluminescent rods. Surface transit dose measurements were made using esophageal and endobronchial catheters, a gynecologic tandem, and an interstitial needle. No difference was detected in thermoluminescent dosimeter rod responses to 4 MV and Ir-192 spectra (427 nC/Gy) in a range of dose between 2 and 300 cGy. The transit dose at 0.5 cm from an endobronchial catheter was 0.31 cGy/(Curie-fraction) and followed an inverse square fall-off with increasing distance. Surface transit doses ranged from 0.38 cGy/(Curie-fraction) for an esophageal catheter to 1.03 cGy/(Curie-fraction) for an endobronchial catheter. Source velocity is dependent on the interdwell distance and varies between 220-452 mm/sec. A numeric algorithm was developed to calculate total transit dose, and was based on a dynamic point approximation for the moving high dose rate source. This algorithm reliably predicted the empirical transit doses and demonstrated that total transit dose is dependent on source velocity, number of fractions, and source activity. Surface transit doses are dependent on applicator diameter and wall material and thickness. Total transit doses within or outside the desired treatment volume are typically <100 cGy, but may exceed 200 cGy when using a large number of fractions with a high activity source. 9 refs., 8 figs., 1 tab.

  10. High brachytherapy doses can counteract hypoxia in cervical cancer—a modelling study

    Science.gov (United States)

    Lindblom, Emely; Dasu, Alexandru; Beskow, Catharina; Toma-Dasu, Iuliana

    2017-01-01

    Tumour hypoxia is a well-known adverse factor for the outcome of radiotherapy. For cervical tumours in particular, several studies indicate large variability in tumour oxygenation. However, clinical evidence shows that the management of cervical cancer including brachytherapy leads to high rate of success. It was the purpose of this study to investigate whether the success of brachytherapy for cervical cancer, seemingly regardless of oxygenation status, could be explained by the characteristics of the brachytherapy dose distributions. To this end, a previously used in silico model of tumour oxygenation and radiation response was further developed to simulate the treatment of cervical cancer employing a combination of external beam radiotherapy and intracavitary brachytherapy. Using a clinically-derived brachytherapy dose distribution and assuming a homogeneous dose delivered by external radiotherapy, cell survival was assessed on voxel level by taking into account the variation of sensitivity with oxygenation as well as the effects of repair, repopulation and reoxygenation during treatment. Various scenarios were considered for the conformity of the brachytherapy dose distribution to the hypoxic region in the target. By using the clinically-prescribed brachytherapy dose distribution and varying the total dose delivered with external beam radiotherapy in 25 fractions, the resulting values of the dose for 50% tumour control, D 50, were in agreement with clinically-observed values for high cure rates if fast reoxygenation was assumed. The D 50 was furthermore similar for the different degrees of conformity of the brachytherapy dose distribution to the tumour, regardless of whether the hypoxic fraction was 10%, 25%, or 40%. To achieve 50% control with external RT only, a total dose of more than 70 Gy in 25 fractions would be required for all cases considered. It can thus be concluded that the high doses delivered in brachytherapy can counteract the increased

  11. [Permanent implant prostate cancer brachytherapy: 2013 state-of-the art].

    Science.gov (United States)

    Cosset, J-M; Hannoun-Lévi, J-M; Peiffert, D; Delannes, M; Pommier, P; Pierrat, N; Nickers, P; Thomas, L; Chauveinc, L

    2013-04-01

    With an experience of more than 25 years for the pioneers (and more than 14 years in France), permanent implant brachytherapy using iodine 125 seeds (essentially) is now recognized as a valuable alternative therapy for localized low-risk prostate cancer patients. The possible extension of the indications of exclusive brachytherapy towards selected patients in the intermediate-risk group has now been confirmed by several studies. Moreover, for the other patients in the intermediate-risk group and for the patients in the high-risk group, brachytherapy, as an addition to external radiotherapy, could represent one of the best ways to escalate the dose. Different permanent implant brachytherapy techniques have been proposed; preplanning or real-time procedure, loose or stranded seeds (or both), manual or automatic injection of the seeds. The main point here is the ability to perfectly master the procedure and to comply with the dosimetric constraints, which have been recently redefined by the international societies, such as the GEC-ESTRO group. Mid- and long-term results, which are now available in the literature, indicate relapse-free survival rates of about 90% at 5-10 years, the best results being obtained with satisfactory dosimetric data. Comparative data have shown that the incontinence and impotence rates after brachytherapy seemed to be significantly inferior to what is currently observed after surgery. However, a risk of about 3 to 5% of urinary retention is usually reported after brachytherapy, as well as an irritative urinary syndrome, which may significantly alter the quality of life of the patients, and last several months. In spite of those drawbacks, with excellent long-term results, low rates of incontinence and impotence, and emerging new indications (focal brachytherapy, salvage brachytherapy after localized failure of an external irradiation), permanent implant prostate brachytherapy can be expected to be proposed to an increasing number of patients

  12. Dosimetric characterization of the Cobal-60 bebig Co0.A86 source, using Monte Carlo simulation; Caracterizacion dosimetric de la fuentes de cobalto-60 bebig Co0.A86 mediante simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Almansa Lopez, J.; Guerrero Alcalde, R.; Torres Donaire, J.; Lallena Rojo, A.

    2013-07-01

    They nourish the leading brachytherapy planning systems. The objective of this work is, for the source of Co-60 BEBIG Co0.A86 of HDR, calculating the dosimetry in water and get parameters and functions described in the Protocol TG-43. using PENELOPE and Geant4 simulation codes, previously used for the simulation of sources of brachytherapy, incorporating the recommendations given in the 229 of the AAPM report. (Author)

  13. Use of Monte Carlo Methods for determination of isodose curves in brachytherapy; Uso de tecnicas Monte Carlo para determinacao de curvas de isodose em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Jose Wilson

    2001-08-01

    Brachytherapy is a special form of cancer treatment in which the radioactive source is very close to or inside the tumor with the objective of causing the necrosis of the cancerous tissue. The intensity of cell response to the radiation varies according to the tissue type and degree of differentiation. Since the malign cells are less differentiated than the normal ones, they are more sensitive to the radiation. This is the basis for radiotherapy techniques. Institutes that work with the application of high dose rates use sophisticated computer programs to calculate the necessary dose to achieve the necrosis of the tumor and the same time, minimizing the irradiation of tissues and organs of the neighborhood. With knowledge the characteristics of the source and the tumor, it is possible to trace isodose curves with the necessary information for planning the brachytherapy in patients. The objective of this work is, using Monte Carlo techniques, to develop a computer program - the ISODOSE - which allows to determine isodose curves in turn of linear radioactive sources used in brachytherapy. The development of ISODOSE is important because the available commercial programs, in general, are very expensive and practically inaccessible to small clinics. The use of Monte Carlo techniques is viable because they avoid problems inherent to analytic solutions as, for instance , the integration of functions with singularities in its domain. The results of ISODOSE were compared with similar data found in the literature and also with those obtained at the institutes of radiotherapy of the 'Hospital do Cancer do Recife' and of the 'Hospital Portugues do Recife'. ISODOSE presented good performance, mainly, due to the Monte Carlo techniques, that allowed a quite detailed drawing of the isodose curves in turn of linear sources. (author)

  14. Salvage robot-assisted radical prostatectomy after brachytherapy: our experience

    Directory of Open Access Journals (Sweden)

    A. V. Govorov

    2014-01-01

    Full Text Available In case of recurrence of prostate cancer after radiation therapy patient may be offered salvage radical prostatectomy (both open and laparoscopic/robotic, hormone therapy, and a number of alternative techniques such as salvage cryoablation, HIFU-therapy and brachytherapy. Results of monitoring of patients for 10 years after salvage treatment of prostate cancer are known only after salvage prostatectomy. Technically radical prostatectomy after radiation therapy is associated with a large number of complications if compared with primary radical prostatectomy. The most frequent complications after salvage prostatectomy include incontinence, stricture formation of urethrovesical anastomosis, rectal injury, acute urinary retention and infectious complications.

  15. Prosper: image and robot-guided prostate brachytherapy

    CERN Document Server

    Baumann, Michael; Daanen, Vincent; Descotes, Jean-Luc; Giraud, Jean-Yves; Hungr, Nikolai; Leroy, Antoine; Long, Jean-Alexandre; Martin, Sébastien; Troccaz, Jocelyne

    2011-01-01

    Brachytherapy for localized prostate cancer consists in destroying cancer by introducing iodine radioactive seeds into the gland through hollow needles. The planning of the position of the seeds and their introduction into the prostate is based on intra-operative ultrasound (US) imaging. We propose to optimize the global quality of the procedure by: i) using 3D US; ii) enhancing US data with MRI registration; iii) using a specially designed needle-insertion robot, connected to the imaging data. The imaging methods have been successfully tested on patient data while the robot accuracy has been evaluated on a realistic deformable phantom.

  16. Growth delay effect of combined interstitial hyperthermia and brachytherapy in a rat solid tumor model.

    Science.gov (United States)

    Papadopoulos, D; Kimler, B F; Estes, N C; Durham, F J

    1989-01-01

    The rat mammary AC33 solid tumor model was used to investigate the efficacy of interstitial hyperthermia and/or brachytherapy. Subcutaneous flank tumors were heated with an interstitial microwave (915 MHz) antenna to a temperature of 43 +/- 0.5 degrees C for 45 min for two treatments, three days apart, and/or implanted with Ir-192 seeds for three days (-25 Gy tumor dose). Following treatments, tumors were measured 2 to 3 times per week. Hyperthermia alone produced a modest delay in tumor volume regrowth, while brachytherapy was substantially more effective. The combination produced a improvement in tumor regrowth delay compared to brachytherapy alone.

  17. Study of factors influencing dose distribution of brachytherapy in cervical cancer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective To study the factors which influence the dose distribution of brachytherapy in cervical cancer.Methods Ninety-five patients with cervical cancer Ⅱ-Ⅲb received fundamental radiation therapy including brachytherapy in our department from Aug.2004 to Nov.2005.The deviation of isodose curve of brachytherapy was based on A-B reference system,and the deviation of dose was defined by measuring in a practical standard body model.Results The factors influencing isodose offset significantly were parametrial...

  18. LOW-DOSE RATE BRACHYTHERAPY FOR PROSTATE CANCER: DIFFERENT INDICATIONS – DIFFERENT RESULTS

    Directory of Open Access Journals (Sweden)

    V. A. Biryukov

    2014-07-01

    Full Text Available In Russia, there is presently a growing interest in low-dose intratissue radiotherapy (brachytherapy for locally advanced prostate cancer (PC. Since its inception, current brachytherapy has undergone a number of significant changes in terms of improved visualization and better treatment planning and monitoring, which is sure to have affected the higher quality of their performance and better long-term results. The main purpose of the given paper is to generalize the data of foreign investigators who have the greatest experience with brachytherapy for its further use in the treatment of patients with locally advanced PC under the conditions of Russian clinics.

  19. High dose brachytherapy in pediatric oncology; Braquiterapia com alta taxa de dose em oncologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Ferrigno, Robson; Codjaian, Osanna Esther; Novaes, Paulo Eduardo R.S.; Trippe, Nivaldo [Fundacao Antonio Prudente, Sao Paulo, SP (Brazil). Hospital A.C. Camargo. Dept. de Radioterapia

    1995-05-01

    Brachytherapy is a kind of radiotherapy that has been used in the multidisciplinary approach of some pediatric tumors, such as soft tissue sarcomas of the extremities, head and neck and urogenital tract. Recent technological advances in this area lead to development of computerized high dose rate remote afterloading brachytherapy. This type of treatment has some advantages compared to low dose rate brachytherapy traditionally used. This article describes not only the characteristics and advantages of this kind of treatment, but also the preliminary results of the first seven children treated with high dose rate at the Hospital A.C.Camargo. (author) 10 refs., 8 figs.

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

    Science.gov (United States)

    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

  1. The role of brachytherapy in the definitive management of prostate cancer; Place de la curietherapie dans le traitement du cancer prostatique localise

    Energy Technology Data Exchange (ETDEWEB)

    Crook, J. [British Columbia Cancer Agency, Center for the Southern Interior, 399, Royal Avenue, Kelowna, British Columbia, V1Y 5L33 (Canada)

    2011-06-15

    Over the past two decades, brachytherapy has played an ever expanding role in the definitive radiotherapy of prostate cancer. Brachytherapy surpasses external beam radiotherapy in its ability to deliver intense intra-prostatic dose escalation. Although initially low dose rate permanent seed brachytherapy was favored for favorable risk prostate cancers, and high dose rate temporary brachytherapy for intermediate and advanced disease, both types of brachytherapy now have a place across all the risk groups of localized prostate cancer. This article will review indications and patient selection, planning and technical aspects, toxicity and efficacy for both low and high dose rate prostate brachytherapy. (author)

  2. A new technique in brachytherapy for the putting in operation of the radiation protection principle named ''ALARA': the P.D.R. (acronym for Pulsed Dose Rate); Une nouvelle technique en curietherapie pour la mise en oeuvre du principe de radioprotection dit ''ALARA'': le PDR

    Energy Technology Data Exchange (ETDEWEB)

    Hoffstetter, S.; Aletti, P.; Bellut, F.; Peiffert, D. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France)

    1998-07-01

    This article presents successively the different techniques of brachytherapy and gives the radiation doses received in 1995 at the beginning of the use of the projector of iridium source and in 1997 with its partial utilization. On this base, an estimation of the number of applications using this type of apparatus and then a reduction of doses received is equally proposed. (N.C.)

  3. Dose-rate distribution of {sup 32}P-glass microspheres for intra-arterial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Carla C.; Moralles, Mauricio; Sene, Frank F.; Martinelli, Jose R. [Centro de Ciencia e Tecnologia de Materiais, IPEN, Av. Lineu Prestes 2242, Sao Paulo, Sao Paulo 05508-000 (Brazil); Centro do Reator de Pesquisas, Energy and Nuclear Research Institute, IPEN/CNEN, CP 11049, CEP 05422-970, Sao Paulo, Sao Paulo (Brazil); Centro de Ciencia e Tecnologia de Materiais, IPEN, Av. Lineu Prestes 2242, Sao Paulo, Sao Paulo 05508-000 (Brazil)

    2010-02-15

    Purpose: The intra-arterial administration of radioactive glass microspheres is an alternative therapy option for treating primary hepatocellular carcinoma, the main cause of liver cancer death, and metastatic liver cancer, another important kind of cancer induced in the liver. The technique involves the administration of radioactive microspheres in the hepatic artery, which are trapped preferentially in the tumor. Methods: In this work the GEANT4 toolkit was used to calculate the radial dose-rate distributions in water from {sup 32}P-loaded glass microspheres and also from {sup 90}Y-loaded glass microspheres. To validate the toolkit for this application, the authors compared the dose-rate distribution of {sup 32}P and {sup 90}Y point sources in water with data from the International Commission on Radiation Units and Measurements report 72. Results: Tables of radial dose-rate distributions are provided for practical use in brachytherapy planning with these microspheres. Conclusions: The simulations with the microspheres show that the shape of the beta ray energy spectra with respect to the {sup 32}P and {sup 90}Y sources is significantly modified by the glass matrix.

  4. Development of an encapsulation method using plasma arc welding to produce iodine-125 seeds for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Feher, Anselmo; Calvo, Wilson A.P.; Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Somessari, Samir L.; Costa, Osvaldo L.; Moura, Joao A.; Moura, Eduardo S.; Souza, Carla D.; Rela, Paulo R., E-mail: afeher@ipen.b, E-mail: wapcalvo@ipen.b, E-mail: elisaros@ipen.b, E-mail: somessar@ipen.b, E-mail: olcosta@ipen.b, E-mail: esmoura@ipen.b, E-mail: cdsouza@ipen.b, E-mail: prela@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer is public health problem in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing Iodine-125 radioisotope are implanted into the prostate gland. The seed consists of a titanium sealed capsule with 0.8 mm external diameter and 4.5 mm length, containing a central silver wire with adsorbed Iodine-125. The Plasma Arc Welding (PAW) is one of the viable techniques for sealing process. The equipment used in this technique is less costly than in other processes, such as, Laser Beam Welding (LBW). The main purpose of this work was the development of an encapsulation method using PAW. The development of this work has presented the following phases: cutting and cleaning titanium tube, determination of the welding parameters, development of a titanium tube holding device for PAW, sealed sources validation according to ISO 2919 - Sealed Radioactive Sources - General Requirements and Classification, and metallographic assays. The developed procedure to seal Iodine-125 seeds using PAW has shown high efficiency, satisfying all the established requirements of ISO 2919. The results obtained in this work will give the possibility to establish a routine production process according to the orientations presented in resolution RDC 17 - Good Manufacturing Practices to Medical Products defined by the ANVISA - National Agency of Sanitary Surveillance. (author)

  5. Review of advanced catheter technologies in radiation oncology brachytherapy procedures

    Directory of Open Access Journals (Sweden)

    Zhou J

    2015-07-01

    Full Text Available Jun Zhou,1,2 Leonid Zamdborg,1 Evelyn Sebastian1 1Department of Radiation Oncology, Beaumont Health System, 2Oakland University William Beaumont School of Medicine, Royal Oak, MI, USA Abstract: The development of new catheter and applicator technologies in recent years has significantly improved treatment accuracy, efficiency, and outcomes in brachytherapy. In this paper, we review these advances, focusing on the performance of catheter imaging and reconstruction techniques in brachytherapy procedures using magnetic resonance images and electromagnetic tracking. The accuracy of catheter reconstruction, imaging artifacts, and other notable properties of plastic and titanium applicators in gynecologic treatments are reviewed. The accuracy, noise performance, and limitations of electromagnetic tracking for catheter reconstruction are discussed. Several newly developed applicators for accelerated partial breast irradiation and gynecologic treatments are also reviewed. New hypofractionated high dose rate treatment schemes in prostate cancer and accelerated partial breast irradiation are presented. Keywords: catheter technologies, catheter reconstruction, electromagnetic tracking, hypofractionated high dose rate treatment, accelerated partial breast irradiation

  6. Iodine-125 orbital brachytherapy with a prosthetic implant in situ

    Energy Technology Data Exchange (ETDEWEB)

    Stannard, Clare [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Radiation Oncology; Maree, Gert; Munro, Roger [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Medical Physics; Lecuona, Karin [Groote Schuur Hospital and Cape Town Univ. (South Africa). Dept. of Ophthalmology; Sauerwein, Wolfgang [Universitaetsklinikum Essen (Germany). Strahlenklinik, NCTeam

    2011-05-15

    Purpose: Brachytherapy is one method of irradiating the orbit after enucleation of an eye with a malignant tumor that has a potential to recur. It consists of 6 trains of I-125 seeds placed around the periphery of the orbit, a shorter central train, and a metal disc, loaded with seeds, placed beneath the eyelids. The presence of a prosthetic orbital implant requires omission of the central train and adjustment of the activity of the seeds in the anterior orbit around the prosthesis. Patients and Methods: This is a retrospective review of the technical modifications and outcome of 12 patients treated in this manner: 6 with retinoblastoma, 5 with malignant melanoma, and 1 with an intraocular rhabdomyosarcoma. The median dose was 35.5 Gy in 73 hours for retinoblastoma and 56 Gy in 141 hours for malignant melanoma. Patients with retinoblastoma and rhabdomyosarcoma also received chemotherapy. Results: The tubes can be placed satisfactorily around the prosthesis. The increased activity in the anterior half of the tubes produced comparable dose distributions. There have been no orbital recurrences, no extrusion of the prosthesis, and cosmesis is good. Conclusion: Insertion of a prosthetic implant at the time of enucleation greatly enhances the subsequent cosmetic appearance. This should be encouraged unless there is frank tumor in the orbit. Orbital brachytherapy without the central train continues to give excellent local control. The short treatment time and good cosmesis are added advantages. The patient is spared the expense and inconvenience of removing and replacing the prosthetic implant. (orig.)

  7. Methodology of quality control for brachytherapy {sup 125}I seeds

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S.; Zeituni, Carlos A.; Manzoli, Jose E.; Rostelato, Maria Elisa C.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: esmoura@ipen.br

    2007-07-01

    This paper presents the methodology of quality control of {sup 125}I seeds used for brachytherapy. The {sup 125}I seeds are millimeter titanium capsules widely used in permanent implants of prostate cancer, allowing a high dose within the tumour and a low dose on the surrounding tissues, with very low harm to the other tissues. Besides, with this procedure, the patients have a low impotence rate and a small incidence of urinary incontinence. To meet the medical standards, an efficient quality control is necessary, showing values with the minimum uncertainness possible, concerning the seeds dimensions and their respective activities. The medical needles are used to insert the seeds inside the prostate. The needles used in brachytherapy have an internal diameter of 1.0 mm, so it is necessary {sup 125}I seeds with an external maximum diameter of 0.85 mm. For the seeds and the spacer positioning on the planning sheet, the seeds must have a length between 4.5 and 5.0 mm. The activities must not vary more than 5% in each batch of {sup 125}I seeds. For this methodology, we used two ionization chamber detectors and one caliper. In this paper, the methodology using one control batch with 75 seeds manufactured by GE Health care Ltd is presented. (author)

  8. Observations on rotating needle insertions using a brachytherapy robot

    Energy Technology Data Exchange (ETDEWEB)

    Meltsner, M A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Ferrier, N J [Department of Mechanical Engineering, University of Wisconsin, Madison, WI 53706 (United States); Thomadsen, B R [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2007-09-21

    A robot designed for prostate brachytherapy implantations has the potential to greatly improve treatment success. Much of the research in robotic surgery focuses on measuring accuracy. However, there exist many factors that must be optimized before an analysis of needle placement accuracy can be determined. Some of these parameters include choice of the needle type, insertion velocity, usefulness of the rotating needle and rotation speed. These parameters may affect the force at which the needle interacts with the tissue. A reduction in force has been shown to decrease the compression of the prostate and potentially increase the accuracy of seed position. Rotating the needle as it is inserted may reduce frictional forces while increasing accuracy. However, needle rotations are considered to increase tissue damage due to the drilling nature of the insertion. We explore many of the factors involved in optimizing a brachytherapy robot, and the potential effects each parameter may have on the procedure. We also investigate the interaction of rotating needles in gel and suggest the rotate-cannula-only method of conical needle insertion to minimize any tissue damage while still maintaining the benefits of reduced force and increased accuracy.

  9. SU-E-T-477: An Efficient Dose Correction Algorithm Accounting for Tissue Heterogeneities in LDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S; Lai, P [University of Toronto, Medical Biophysics Dept., Toronto, ON (Canada); Karotki, A; Keller, B; Beachey, D; Pignol, J [Sunnybrook Health Sciences Centre, Toronto, ON (Canada)

    2014-06-01

    Purpose: Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose surrounding the brachytherapy seeds is based on American Association of Physicist in Medicine Task Group No. 43 (TG-43 formalism) which generates the dose in homogeneous water medium. Recently, AAPM Task Group No. 186 emphasized the importance of accounting for tissue heterogeneities. This can be done using Monte Carlo (MC) methods, but it requires knowing the source structure and tissue atomic composition accurately. In this work we describe an efficient analytical dose inhomogeneity correction algorithm implemented using MIM Symphony treatment planning platform to calculate dose distributions in heterogeneous media. Methods: An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG-43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. Results: The dose distributions obtained through applying ICF to TG-43 protocol agreed very well with those of Monte Carlo simulations as well as experiments in all phantoms. In all cases, the mean relative error was reduced by at least 50% when ICF correction factor was applied to the TG-43 protocol. Conclusion: We have developed a new analytical dose calculation method which enables personalized dose calculations in heterogeneous media. The advantages over stochastic methods are computational efficiency and the ease of integration into clinical setting as detailed source structure and tissue segmentation are not needed. University of Toronto, Natural Sciences and

  10. Brachytherapy, A viable option of globe salvage in treatment of large ciliary body melanocytoma

    Directory of Open Access Journals (Sweden)

    Mahesh P Shanmugam

    2014-01-01

    Full Text Available We report a case of large histopathologically proven melanocytoma of the ciliary body in a 15-year-old male, presented with rapid extraocular growth following incisional biopsy with scleral patch graft. We chose brachytherapy with Ruthenium 106 plaque over enucleation as the later was refused by the parents. The initial apical height of the tumor was 14.2 mm on ultrasonography. Two weeks after brachytherapy, the mass regressed to a size of 8.1 mm and 1 year later to 6.7 mm. This is the first case report showing the response of brachytherapy to ciliary body melanocytoma, which results in ocular and visual acuity salvation with considerable decreased in size of the tumor. The authors conclude that brachytherapy is an option in the management of non-resectable melanocytoma of the ciliary body.

  11. Penile cancer brachytherapy HDR mould technique used at the Holycross Cancer Center

    OpenAIRE

    Matys, Robert; Kubicka-Mendak, Iwona; Łyczek, Jarosław; Pawłowski, Piotr; Stawiarska, Iwona; Miedzinska, Joanna; Banatkiewicz, Paweł; Łaskawska-Wiatr, Aldona; Wittych, Justyna

    2011-01-01

    The aim of this pictorial essay is to present the mould based HDR brachytherapy technique used at the Holycross Cancer Center for penile cancer patients. We use images to describe this method step by step.

  12. Penile cancer brachytherapy HDR mould technique used at the Holycross Cancer Center.

    Science.gov (United States)

    Matys, Robert; Kubicka-Mendak, Iwona; Lyczek, Jarosław; Pawłowski, Piotr; Stawiarska, Iwona; Miedzinska, Joanna; Banatkiewicz, Paweł; Laskawska-Wiatr, Aldona; Wittych, Justyna

    2011-12-01

    The aim of this pictorial essay is to present the mould based HDR brachytherapy technique used at the Holycross Cancer Center for penile cancer patients. We use images to describe this method step by step.

  13. Study of factors influencing dose distribution of brachytherapy in cervical cancer

    Institute of Scientific and Technical Information of China (English)

    Liu Zi; Gao Ying; Luo Wei; Wang Guoqing; Wang Ruihua; Zheng Wei; Liu Rui

    2008-01-01

    Objective To study the factors which influence the dose distribution of brachytherapy in cervical cancer. Methods Ninety-five patients with cervical cancer Ⅱ - Ⅲ b received fundamental radiation therapy including brachytherapy in our department from Aug. 2004 to Nov. 2005. The deviation of isodose curve of brachytherapy was based on A-B reference system, and the deviation of dose was defined by measuring in a practical standard body model. Results The factors influencing isodose offset significantly were parametrial infiltrating degree, and anatomy factor of cervical cancer and operating skill. The degree of isodose offset could not be lowered with the increased frequency of brachytherapy. Conclusion Making simulation in cervical brachythecapy is necessary not only for the identification of the deviation of isodose curve but also for adjusting the dose distribution and revising the plan of radiotherapy.

  14. Monte Carlo study of the impact of a magnetic field on the dose distribution in MRI-guided HDR brachytherapy using Ir-192

    Science.gov (United States)

    Beld, E.; Seevinck, P. R.; Lagendijk, J. J. W.; Viergever, M. A.; Moerland, M. A.

    2016-09-01

    In the process of developing a robotic MRI-guided high-dose-rate (HDR) prostate brachytherapy treatment, the influence of the MRI scanner’s magnetic field on the dose distribution needs to be investigated. A magnetic field causes a deflection of electrons in the plane perpendicular to the magnetic field, and it leads to less lateral scattering along the direction parallel with the magnetic field. Monte Carlo simulations were carried out to determine the influence of the magnetic field on the electron behavior and on the total dose distribution around an Ir-192 source. Furthermore, the influence of air pockets being present near the source was studied. The Monte Carlo package Geant4 was utilized for the simulations. The simulated geometries consisted of a simplified point source inside a water phantom. Magnetic field strengths of 0 T, 1.5 T, 3 T, and 7 T were considered. The simulation results demonstrated that the dose distribution was nearly unaffected by the magnetic field for all investigated magnetic field strengths. Evidence was found that, from a dose perspective, the HDR prostate brachytherapy treatment using Ir-192 can be performed safely inside the MRI scanner. No need was found to account for the magnetic field during treatment planning. Nevertheless, the presence of air pockets in close vicinity to the source, particularly along the direction parallel with the magnetic field, appeared to be an important point for consideration.

  15. 6th Annual Conference of Indian Brachytherapy Society 2016 (IBSCON 2016) Proceedings

    OpenAIRE

    Srinivasan, Venkatesan; Kuppusamy, Thayalan; Bhalavat, Rajendra L.; ,; Prahlad H Yathiraj; Kumar, Uday P.; Sharan, Krishna; Singh, Anshul; Reddy, Anusha; Fernandes, Donald; Vidyasagar, M.S.; Kumar, Rishabh; Kala, Prachi; Mandal, Sanjeet; Vibhay, Pareek

    2016-01-01

    Purpose To report the incidence, severity, and time of onset of late toxicities in patients of endometrial adenocarcinoma (EA) treated with external beam radiotherapy (EBRT) + brachytherapy (BT), or vaginal brachytherapy (VBT) alone. Material and methods Archives of a single institution from 2008-2015 were studied. The indications for EBRT and VBT were based on standard recommendations. EBRT was planned to 50 Gy/25 fractions/5 weeks/3DCRT with 4-field ‘box’ technique on a dual energy linear a...

  16. Highly efficient method for production of radioactive silver seed cores for brachytherapy.

    Science.gov (United States)

    Cardoso, Roberta Mansini; de Souza, Carla Daruich; Rostelato, Maria Elisa Chuery Martins; Araki, Koiti

    2017-02-01

    A simple and highly efficient (shorter reaction time and almost no rework) method for production of iodine based radioactive silver seed cores for brachytherapy is described. The method allows almost quantitative deposition of iodine-131 on dozens of silver substrates at once, with even distribution of activity per core and insignificant amounts of liquid and solid radioactive wastes, allowing the fabrication of cheaper radioactive iodine seeds for brachytherapy.

  17. Study of the effect of usual heterogeneities in brachytherapy using Monte Carlo simulation; Estudio del efecto de heterogeneidades usuales en braquiterapia mediante simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Vera Sanchez, J. A.; Ruiz Morales, C.; Tobarra Gonzalez, B. M.

    2013-07-01

    The majority of current planning in brachytherapy systems don't count the composition of materials they form applicators, or the characteristics of the main interfaces present in the treatments. The objective of this study It is to compare the dosimetry distributions obtained by Monte Carlo simulations in geometric mannequins that they represent general features of the treatments that we find in our clinical practice, with results calculated according to the TG-43 formalism based on the existing consensus data for Ir-192 mHDR-v2 source. (Author)

  18. Brachytherapy in childhood rhabdomyosarcoma treatment; Braquiterapia no tratamento do rabdomiossarcoma da infancia