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Sample records for brachytherapy seed reconstruction

  1. Detection and correction of patient movement in prostate brachytherapy seed reconstruction

    Science.gov (United States)

    Lam, Steve T.; Cho, Paul S.; Marks, Robert J., II; Narayanan, Sreeram

    2005-05-01

    Intraoperative dosimetry of prostate brachytherapy can help optimize the dose distribution and potentially improve clinical outcome. Evaluation of dose distribution during the seed implant procedure requires the knowledge of 3D seed coordinates. Fluoroscopy-based seed localization is a viable option. From three x-ray projections obtained at different gantry angles, 3D seed positions can be determined. However, when local anaesthesia is used for prostate brachytherapy, the patient movement during fluoroscopy image capture becomes a practical problem. If uncorrected, the errors introduced by patient motion between image captures would cause seed mismatches. Subsequently, the seed reconstruction algorithm would either fail to reconstruct or yield erroneous results. We have developed an algorithm that permits detection and correction of patient movement that may occur between fluoroscopy image captures. The patient movement is decomposed into translational shifts along the tabletop and rotation about an axis perpendicular to the tabletop. The property of spatial invariance of the co-planar imaging geometry is used for lateral movement correction. Cranio-caudal movement is corrected by analysing the perspective invariance along the x-ray axis. Rotation is estimated by an iterative method. The method can detect and correct for the range of patient movement commonly seen in the clinical environment. The algorithm has been implemented for routine clinical use as the preprocessing step for seed reconstruction.

  2. Three-dimensional seed reconstruction for prostate brachytherapy using Hough trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Steve T [Department of Electrical Engineering, University of Washington, Seattle, WA 98195-2500 (United States); Cho, Paul S [Department of Electrical Engineering, University of Washington, Seattle, WA 98195-2500 (United States); MarksII, Robert J [Department of Engineering, Baylor University, Waco, TX 76798-7356 (United States); Narayanan, Sreeram [Department of Electrical Engineering, University of Washington, Seattle, WA 98195-2500 (United States)

    2004-02-21

    In order to perform intra-operative or post-implant dosimetry in prostate brachytherapy, the 3D coordinates of the implanted radioactive seeds must be determined. Film or fluoroscopy based seed reconstruction techniques use back projection of x-ray data obtained at two or three x-ray positions. These methods, however, do not perform well when some of the seed images are undetected. To overcome this problem we have developed an alternate technique for 3D seed localization using the principle of Hough transform. The Hough method utilizes the fact that, for each seed coordinate in three dimensions, there exists a unique trajectory in Hough feature space. In this paper we present the Hough transform parametric equations to describe the path of the seed projections from one view to the next and a method to reconstruct the 3D seed coordinates. The results of simulation and phantom studies indicate that the Hough trajectory method can accurately determine the 3D seed positions even from an incomplete dataset.

  3. Three-dimensional seed reconstruction for prostate brachytherapy using Hough trajectories

    Science.gov (United States)

    Lam, Steve T.; Cho, Paul S.; Marks, Robert J., II; Narayanan, Sreeram

    2004-02-01

    In order to perform intra-operative or post-implant dosimetry in prostate brachytherapy, the 3D coordinates of the implanted radioactive seeds must be determined. Film or fluoroscopy based seed reconstruction techniques use back projection of x-ray data obtained at two or three x-ray positions. These methods, however, do not perform well when some of the seed images are undetected. To overcome this problem we have developed an alternate technique for 3D seed localization using the principle of Hough transform. The Hough method utilizes the fact that, for each seed coordinate in three dimensions, there exists a unique trajectory in Hough feature space. In this paper we present the Hough transform parametric equations to describe the path of the seed projections from one view to the next and a method to reconstruct the 3D seed coordinates. The results of simulation and phantom studies indicate that the Hough trajectory method can accurately determine the 3D seed positions even from an incomplete dataset.

  4. Operator-free, film-based 3D seed reconstruction in brachytherapy

    International Nuclear Information System (INIS)

    In brachytherapy implants, the accuracy of dose calculation depends on the ability to localize radioactive sources correctly. If performed manually using planar images, this is a time-consuming and often error-prone process - primarily because each seed must be identified on (at least) two films. In principle, three films should allow automatic seed identification and position reconstruction; however, practical implementation of the numerous algorithms proposed so far appears to have only limited reliability. The motivation behind this work is to create a fast and reliable system for real-time implant evaluation using digital planar images obtained from radiotherapy simulators, or mobile x-ray/fluoroscopy systems. We have developed algorithms and code for 3D seed coordinate reconstruction. The input consists of projections of seed positions in each of three isocentric images taken at arbitrary angles. The method proposed here consists of a set of heuristic rules (in a sense, a learning algorithm) that attempts to minimize seed misclassifications. In the clinic, this means that the system must be impervious to errors resulting from patient motion as well as from finite tolerances accepted in equipment settings. The software program was tested with simulated data, a pelvic phantom and patient data. One hundred and twenty permanent prostate implants were examined (105125I and 15103Pd) with the number of seeds ranging from 35 to 138 (average 79). The mean distance between actual and reconstructed seed positions is in the range 0.03-0.11 cm. On a Pentium III computer at 600 MHz the reconstruction process takes 10-30 s. The total number of seeds is independently validated. The process is robust and able to account for errors introduced in the clinic. (author)

  5. Operator-free, film-based 3D seed reconstruction in brachytherapy.

    Science.gov (United States)

    Todor, D A; Cohen, G N; Amols, H I; Zaider, M

    2002-06-21

    In brachytherapy implants, the accuracy of dose calculation depends on the ability to localize radioactive sources correctly. If performed manually using planar images, this is a time-consuming and often error-prone process-primarily because each seed must be identified on (at least) two films. In principle, three films should allow automatic seed identification and position reconstruction; however, practical implementation of the numerous algorithms proposed so far appears to have only limited reliability. The motivation behind this work is to create a fast and reliable system for real-time implant evaluation using digital planar images obtained from radiotherapy simulators, or mobile x-ray/fluoroscopy systems. We have developed algorithms and code for 3D seed coordinate reconstruction. The input consists of projections of seed positions in each of three isocentric images taken at arbitrary angles. The method proposed here consists of a set of heuristic rules (in a sense, a learning algorithm) that attempts to minimize seed misclassifications. In the clinic, this means that the system must be impervious to errors resulting from patient motion as well as from finite tolerances accepted in equipment settings. The software program was tested with simulated data, a pelvic phantom and patient data. One hundred and twenty permanent prostate implants were examined (105 125I and 15 103Pd) with the number of seeds ranging from 35 to 138 (average 79). The mean distance between actual and reconstructed seed positions is in the range 0.03-0.11 cm. On a Pentium III computer at 600 MHz the reconstruction process takes 10-30 s. The total number of seeds is independently validated. The process is robust and able to account for errors introduced in the clinic. PMID:12118599

  6. Operator-free, film-based 3D seed reconstruction in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Todor, D.A.; Cohen, G.N.; Amols, H.I.; Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2002-06-21

    In brachytherapy implants, the accuracy of dose calculation depends on the ability to localize radioactive sources correctly. If performed manually using planar images, this is a time-consuming and often error-prone process - primarily because each seed must be identified on (at least) two films. In principle, three films should allow automatic seed identification and position reconstruction; however, practical implementation of the numerous algorithms proposed so far appears to have only limited reliability. The motivation behind this work is to create a fast and reliable system for real-time implant evaluation using digital planar images obtained from radiotherapy simulators, or mobile x-ray/fluoroscopy systems. We have developed algorithms and code for 3D seed coordinate reconstruction. The input consists of projections of seed positions in each of three isocentric images taken at arbitrary angles. The method proposed here consists of a set of heuristic rules (in a sense, a learning algorithm) that attempts to minimize seed misclassifications. In the clinic, this means that the system must be impervious to errors resulting from patient motion as well as from finite tolerances accepted in equipment settings. The software program was tested with simulated data, a pelvic phantom and patient data. One hundred and twenty permanent prostate implants were examined (105{sup 125}I and 15{sup 103}Pd) with the number of seeds ranging from 35 to 138 (average 79). The mean distance between actual and reconstructed seed positions is in the range 0.03-0.11 cm. On a Pentium III computer at 600 MHz the reconstruction process takes 10-30 s. The total number of seeds is independently validated. The process is robust and able to account for errors introduced in the clinic. (author)

  7. Reconstruction of brachytherapy seed positions and orientations from cone-beam CT x-ray projections via a novel iterative forward projection matching method

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Damodar; Murphy, Martin J.; Todor, Dorin A.; Weiss, Elisabeth; Williamson, Jeffrey F. [Department of Radiation Oncology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2011-01-15

    Purpose: To generalize and experimentally validate a novel algorithm for reconstructing the 3D pose (position and orientation) of implanted brachytherapy seeds from a set of a few measured 2D cone-beam CT (CBCT) x-ray projections. Methods: The iterative forward projection matching (IFPM) algorithm was generalized to reconstruct the 3D pose, as well as the centroid, of brachytherapy seeds from three to ten measured 2D projections. The gIFPM algorithm finds the set of seed poses that minimizes the sum-of-squared-difference of the pixel-by-pixel intensities between computed and measured autosegmented radiographic projections of the implant. Numerical simulations of clinically realistic brachytherapy seed configurations were performed to demonstrate the proof of principle. An in-house machined brachytherapy phantom, which supports precise specification of seed position and orientation at known values for simulated implant geometries, was used to experimentally validate this algorithm. The phantom was scanned on an ACUITY CBCT digital simulator over a full 660 sinogram projections. Three to ten x-ray images were selected from the full set of CBCT sinogram projections and postprocessed to create binary seed-only images. Results: In the numerical simulations, seed reconstruction position and orientation errors were approximately 0.6 mm and 5 deg., respectively. The physical phantom measurements demonstrated an absolute positional accuracy of (0.78{+-}0.57) mm or less. The {theta} and {phi} angle errors were found to be (5.7{+-}4.9) deg. and (6.0{+-}4.1) deg., respectively, or less when using three projections; with six projections, results were slightly better. The mean registration error was better than 1 mm/6 deg. compared to the measured seed projections. Each test trial converged in 10-20 iterations with computation time of 12-18 min/iteration on a 1 GHz processor. Conclusions: This work describes a novel, accurate, and completely automatic method for reconstructing

  8. Tomosynthesis-based localization of radioactive seeds in prostate brachytherapy

    International Nuclear Information System (INIS)

    Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Several methods have been developed to locate seeds from x-ray projection images, but they fail to detect completely-overlapping seeds, thus necessitating manual intervention. To overcome this limitation, we have developed a new method where (1) a three-dimensional volume is reconstructed from x-ray projection images using a brachytherapy-specific tomosynthesis reconstruction algorithm with built-in blur compensation and (2) the seeds are located in this reconstructed volume. In contrast to other projection-based methods, our method can detect completely overlapping seeds. Our simulation results indicate that we can locate all implanted seeds in the prostate using a tomosynthesis angle of 30 deg. and seven projection images. The mean localization error is 1.27 mm for a case with 100 seeds. We have also tested our method using a prostate phantom with 61 implanted seeds and succeeded in locating all seeds automatically. We believe this new method can be useful for the intraoperative quality assessment of prostate brachytherapy in the future

  9. Photoacoustic imaging of prostate brachytherapy seeds

    OpenAIRE

    Su, Jimmy L.; Bouchard, Richard R.; Karpiouk, Andrei B.; Hazle, John D.; Emelianov, Stanislav Y.

    2011-01-01

    Brachytherapy seed therapy is an increasingly common way to treat prostate cancer through localized radiation. The current standard of care relies on transrectal ultrasound (TRUS) for imaging guidance during the seed placement procedure. As visualization of individual metallic seeds tends to be difficult or inaccurate under TRUS guidance, guide needles are generally tracked to infer seed placement. In an effort to improve seed visualization and placement accuracy, the use of photoacoustic (PA...

  10. Radioactive seed immobilization techniques for interstitial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y. [Thomas Jefferson University, Department of Radiation Oncology, Philadelphia, PA (United States); Messing, E. [University of Rochester, Departments of Urology and Surgery, Rochester, NY (United States); Rubens, D. [University of Rochester, Departments of Imaging Science and Surgery, Rochester, NY (United States); Sarkar, N. [Vanderbilt University, Department of Mechanical Engineering, Nashville, TN (United States); Ng, W. [Nangyang Technical University, School of Mechanical and Aerospace Engineering, Singapore (Singapore)

    2008-06-15

    In prostate brachytherapy, seeds can detach from their deposited sites and move locally in the pelvis or migrate to distant sites including the pulmonary and cardiac regions. Undesirable consequences of seed migration include inadequate dose coverage of the prostate and tissue irradiation effects at the site of migration. Thus, it is clinically important to develop seed immobilization techniques. We first analyze the possible causes for seed movement, and propose three potential techniques for seed immobilization: (1) surgical glue, (2) laser coagulation and (3) diathermy coagulation. The feasibility of each method is explored. Experiments were carried out using fresh bovine livers to investigate the efficacy of seed immobilization using surgical glue. Results have shown that the surgical glue can effectively immobilize the seeds. Evaluation of the radiation dose distribution revealed that the non-immobilized seed movement would change the planned isodose distribution considerably; while by using surgical glue method to immobilize the seeds, the changes were negligible. Prostate brachytherapy seed immobilization is necessary and three alternative mechanisms are promising for addressing this issue. Experiments for exploring the efficacy of the other two proposed methods are ongoing. Devices compatible with the brachytherapy procedure will be designed in future. (orig.)

  11. Epoxy resins used to seal brachytherapy seed

    International Nuclear Information System (INIS)

    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)

  12. Radioactive seed migration after prostate brachytherapy with Iodine-125 using loose seeds versus stranded seeds

    International Nuclear Information System (INIS)

    Objectives: To assess the incidence and clinical parameters that could influence migration of seeds in localized prostate cancer patients treated by stranded versus loose sources by Iodine-125 brachytherapy. Materials and Methods: 100 patients were treated from January/1998 until December/2006. Age, PSA, clinical stage, Gleason, prostate volume, number of seeds, activity of radioactive seeds, and dosimetric parameters, such as V100, V150 and D90 were evaluated. Results: Mean follow-up was 79 months (18 - 120. CI 95%: 72 - 85). Overall, 6 of 100 patients experienced seed migration. Seed migration was found in 4/50 (8%) patients using loose seeds and in 2/50 (4%) treated by stranded seeds. Mean value dosimetric parameters for stranded seeds were greater than those for loose seeds (V100(%): 88.7/82, D90(Gy): 149.2/140.3, D90(%): 104.2/93.8, V150 (%): 53.8/47, respectively). No significant difference in migration of seeds was detected between loose and stranded seeds considering age (p = 0.33), PSA (p = 0.391), prostate volume (p 0.397), activity of radioactive seeds (p = 0.109), number of seeds (p 0.338), V100 (p = 0.332), although significant differences were measured in the values of D90 (% and Gy) (p = 0.022 and 0.011) and V150 (p = 0.023). Conclusions: Seed migration after brachytherapy might occur and it does affect post-implant dosimetry. (author)

  13. 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)

  14. Coherence-based photoacoustic imaging of brachytherapy seeds implanted in a canine prostate

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Song, Danny Y.; Boctor, Emad M.

    2014-03-01

    Visualization of individual brachytherapy seed locations assists with intraoperative updates to brachytherapy treatment plans. Photoacoustic imaging is advantageous when compared to current ultrasound imaging methods, due to its superior sensitivity to metal surrounded by tissue. However, photoacoustic images suffer from poor contrast with insufficient laser fluence. A short-lag spatial coherence (SLSC) beamformer was implemented to enhance these low-contrast photoacoustic signals. Photoacoustic imaging was performed with a transrectal ultrasound probe and an optical fiber surrounded by a light-diffusing sheath, placed at a distance of approximately 4-5 mm from the location of seeds implanted in an in vivo canine prostate. The average energy density through the tip of the sheath was varied from 8 to 167 mJ/cm2. When compared to a fast Fourier transform (FFT)- based reconstruction method, the mean contrast and signal-to-noise ratios were improved by up to 22 dB and a factor of 4, respectively, with the SLSC beamformer (12% of the receive aperture elements were included in the short-lag sum). Image artifacts that were spatially coherent had spatial frequency spectra that were quadrantally symmetric about the origin, while the spatial frequency spectra of the seed signals possessed diagonal symmetry. These differences were utilized to reduce artifacts by 9-14 dB after applying a bandpass filter with diagonal symmetry. Results indicate that advanced methods, such as SLSC beamforming or frequency-based filters, hold promise for intraoperative localization of prostate brachytherapy seeds

  15. 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

  16. Seed-based transrectal ultrasound-fluoroscopy registration method for intraoperative dosimetry analysis of prostate brachytherapy

    International Nuclear Information System (INIS)

    Prostate brachytherapy is an effective treatment option for early-stage prostate cancer. During a prostate brachytherapy procedure, transrectal ultrasound (TRUS) and fluoroscopy imaging modalities complement each other by providing good visualization of soft tissue and implanted seeds, respectively. Therefore, the registration of these two imaging modalities, which are readily available in the operating room, could facilitate intraoperative dosimetry, thus enabling physicians to implant additional seeds into the underdosed portions of the prostate while the patient is still on the operating table. It is desirable to register TRUS and fluoroscopy images by using the seeds as fiducial markers. Although the locations of all the implanted seeds can be reconstructed from three fluoroscopy images, only a fraction of these seeds can be located in TRUS images. It is challenging to register the TRUS and fluoroscopy images by using the identified seeds, since the correspondence between them is unknown. Furthermore, misdetection of nonseed structures as seeds can lead to the inclusion of spurious points in the data set. We developed a new method called iterative optimal assignment (IOA) to overcome these challenges in TRUS-fluoroscopy registration. By using the Hungarian method in an optimization framework, IOA computes a set of transformation parameters that yield the one-to-one correspondence with minimum cost. We have evaluated our registration method at varying noise levels, seed detection rates, and number of spurious points using data collected from 25 patients. We have found that IOA can perform registration with an average root mean square error of about 0.2 cm even when the seed detection rate is only 10%. We believe that IOA can offer a robust solution to seed-based TRUS-fluoroscopy registration, thus making intraoperative dosimetry possible

  17. Radiation pneumonitis caused by a migrated brachytherapy seed lodged in the lung

    International Nuclear Information System (INIS)

    We report a case of radiation pneumonitis caused by a migrated seed lodged in the lung after prostate brachytherapy. A 71-year-old man underwent transperineal interstitial permanent prostate brachytherapy for localized prostate cancer. On the day after brachytherapy, a routine postimplant chest X-ray revealed migration of one seed to the lower lobe of the left lung. After 1 month, pulmonary opacities were observed in the left lower lobe but not near the seed. He was diagnosed with bacterial pneumonia, and antibiotic therapy was commenced. Two months after brachytherapy, the patient's symptoms, laboratory data and pulmonary opacities improved; however, an abnormal shadow (consolidation) developed around the migrated seed. Lung consolidation disappeared almost completely 12 months after brachytherapy without any medical treatment. The abnormal shadow probably represented radiation pneumonitis. To the best of our knowledge, this is the first report of radiation pneumonitis caused by a migrated brachytherapy seed in the lung. (author)

  18. In vivo photoacoustic imaging of prostate brachytherapy seeds

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin; Boctor, Emad M.

    2014-03-01

    We conducted an approved canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. Brachytherapy seeds coated with black ink were inserted into the canine prostate using methods similar to a human procedure. A transperineal, interstitial, fiber optic light delivery method, coupled to a 1064 nm laser, was utilized to irradiate the prostate and the resulting acoustic waves were detected with a transrectal ultrasound probe. The fiber was inserted into a high dose rate (HDR) brachytherapy needle that acted as a light-diffusing sheath, enabling radial light delivery from the tip of the fiber inside the sheath. The axis of the fiber was located at a distance of 4-9 mm from the long axis of the cylindrical seeds. Ultrasound images acquired with the transrectal probe and post-operative CT images of the implanted seeds were analyzed to confirm seed locations. In vivo limitations with insufficient light delivery within the ANSI laser safety limit (100 mJ/cm2) were overcome by utilizing a short-lag spatial coherence (SLSC) beamformer, which provided average seed contrasts of 20-30 dB for energy densities ranging 8-84 mJ/cm2. The average contrast was improved by up to 20 dB with SLSC beamforming compared to conventional delay-and-sum beamforming. There was excellent agreement between photoacoustic, ultrasound, and CT images. Challenges included visualization of photoacoustic artifacts that corresponded with locations of the optical fiber and hyperechoic tissue structures.

  19. Brachytherapy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Brachytherapy What is Brachytherapy and how is it used? ... will I feel during this procedure? What is brachytherapy and how is it used? Brachytherapy is a ...

  20. In vivo visualization of prostate brachytherapy seeds with photoacoustic imaging

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin U.; Boctor, Emad M.

    2014-12-01

    We conducted a canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. A fiber coupled to a 1064-nm Nd:YAG laser was inserted into high-dose-rate brachytherapy needles, which diffused light spherically. These needles were inserted through the perineum into the prostate for interstitial light delivery and the resulting acoustic waves were detected with a transrectal ultrasound probe. Postoperative computed tomography images and ex vivo photoacoustic images confirmed seed locations. Limitations with insufficient light delivery were mitigated with short-lag spatial coherence (SLSC) beamforming, providing a 10-20 dB contrast improvement over delay-and-sum (DAS) beamforming for pulse energies ranging from 6.8 to 10.5 mJ with a fiber-seed distance as large as 9.5 mm. For the same distance and the same range of energy densities, signal-to-noise ratios (SNRs) were similar while the contrast-to-noise ratio (CNR) was higher in SLSC compared to DAS images. Challenges included visualization of signals associated with the interstitial fiber tip and acoustic reverberations between seeds separated by ≤2 mm. Results provide insights into the potential for clinical translation to humans.

  1. Automated treatment planning engine for prostate seed implant brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To develop a computer-intelligent planning engine for automated treatment planning and optimization of ultrasound- and template-guided prostate seed implants. Methods and Materials: The genetic algorithm was modified to reflect the 2D nature of the implantation template. A multi-objective decision scheme was used to rank competing solutions, taking into account dose uniformity and conformity to the planning target volume (PTV), dose-sparing of the urethra and the rectum, and the sensitivity of the resulting dosimetry to seed misplacement. Optimized treatment plans were evaluated using selected dosimetric quantifiers, dose-volume histogram (DVH), and sensitivity analysis based on simulated seed placement errors. These dosimetric planning components were integrated into the Prostate Implant Planning Engine for Radiotherapy (PIPER). Results: PIPER has been used to produce a variety of plans for prostate seed implants. In general, maximization of the minimum peripheral dose (mPD) for given implanted total source strength tended to produce peripherally weighted seed patterns. Minimization of the urethral dose further reduced the loading in the central region of the PTV. Isodose conformity to the PTV was achieved when the set of objectives did not reflect seed positioning uncertainties; the corresponding optimal plan generally required fewer seeds and higher source strength per seed compared to the manual planning experience. When seed placement uncertainties were introduced into the set of treatment planning objectives, the optimal plan tended to reach a compromise between the preplanned outcome and the likelihood of retaining the preferred outcome after implantation. The reduction in the volatility of such seed configurations optimized under uncertainty was verified by sensitivity studies. Conclusion: An automated treatment planning engine incorporating real-time sensitivity analysis was found to be a useful tool in dosimetric planning for prostate

  2. Deterministic calculations of radiation doses from brachytherapy seeds

    International Nuclear Information System (INIS)

    Brachytherapy is used for treating certain types of cancer by inserting radioactive sources into tumours. CDTN/CNEN is developing brachytherapy seeds to be used mainly in prostate cancer treatment. Dose calculations play a very significant role in the characterization of the developed seeds. The current state-of-the-art of computation dosimetry relies on Monte Carlo methods using, for instance, MCNP codes. However, deterministic calculations have some advantages, as, for example, short computer time to find solutions. This paper presents a software developed to calculate doses in a two-dimensional space surrounding the seed, using a deterministic algorithm. The analysed seeds consist of capsules similar to IMC6711 (OncoSeed), that are commercially available. The exposure rates and absorbed doses are computed using the Sievert integral and the Meisberger third order polynomial, respectively. The software also allows the isodose visualization at the surface plan. The user can choose between four different radionuclides (192Ir, 198Au, 137Cs and 60Co). He also have to enter as input data: the exposure rate constant; the source activity; the active length of the source; the number of segments in which the source will be divided; the total source length; the source diameter; and the actual and effective source thickness. The computed results were benchmarked against results from literature and developed software will be used to support the characterization process of the source that is being developed at CDTN. The software was implemented using Borland Delphi in Windows environment and is an alternative to Monte Carlo based codes. (author)

  3. Preparation of 103Pd brachytherapy seeds by electroless plating of 103Pd onto carbon bars

    International Nuclear Information System (INIS)

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

  4. Microfocus X-ray imaging of the internal geometry of brachytherapy seeds

    International Nuclear Information System (INIS)

    Precise and reliable geometrical data on the internal structure of seeds are indispensable for dosimetric calculation in brachytherapy. We used a novel microfocus X-ray imaging technique for observing the internal structure of brachytherapy seeds. Two popular 125I seed models were evaluated. Obtained high precision images enabled us to observe the internal structure of seeds qualitatively. Geometrical size parameters were evaluated quantitatively with uncertainty of 0.01–0.04 mm (k=2). - Highlights: • The internal geometry of brachytherapy seeds was evaluated nondestructively. • A novel microfocus X-ray imaging method was used for the first time for this purpose. • The two 125I seed models commercially available in Japan were evaluated. • The microfocus X-ray imaging method was found to be useful for this purpose. • Geometrical size parameters were obtained for the two seed models

  5. CT guided 125I seed brachytherapy for recurrent rectum cancer

    International Nuclear Information System (INIS)

    Objective: To investigate the technological feasibility, efficacy and morbidity of CT guided 125I seed implantation for recurrent rectum cancer. Methods: Twenty-three patients with recurrent rectum cancer were treated with CT guided interstitial 125I seed brachytherapy. In 20 patients the procedure was performed under epidural anesthesia and 3 patients under local anesthesia. Treatment planning system was used to calculate the number of seeds, the space distribution and the introduction of the seeding needles. Matched peripheral dose (MPD) of 121I seed implantation ranged from 90-120 Gy for patients who had had external radiotherapy, and 140- 160 Gy for those who had not. The planning target volume(PTV) was clinical target volume(CTV) plus 1 cm margin. The range of radioactivity of the 125I seeds was 18.5-25.9 MBq. All these 23 patients had CT scan at 5 mm intervals after implantation for quality evaluation, together with routine chest, pelvic X-ray films within 24-48 hours after seed implantation. Three patients received three-dimensional conformal radiation therapy(3DCRT) to a total dose of 45-50 Gy, with 2-3 Gy/f. Follow-up time was from 3 to 28 months. Results: All patients was able to tolerate seed implantation well. Complete pain relief was observed in 12/15, and partial relief in 2/15 and no response in 1/15, with a response rate of 93%. The local control rate was 87%. The 1- and 2-year survival rate was 93% and 50% respectively. Two of four patients have died of dissemination to the lung after 8 and 12 months. One seed has migrated into the pelvis without causing any untoward morbidity. Conclusion: CT guided 125I seed implantation for recurrent rectum cancer is safe, minimally invasive, causing only mild morbidity. It possesses a high efficacy, yet it should be given in combination with extemal beam radiation and chemotherapy, should distant metastasis be observed. (authors)

  6. 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

  7. Dosimetric study in iodine-125 seeds for brachytherapy application

    International Nuclear Information System (INIS)

    The demand for iodine-125 seeds for use in brachytherapy treatments has experienced an increase along recent years in Brazil and all over the world. All iodine-125 seed must have its operational parameters measured and/or calculated every time changes in the production process are carried out. A complete dosimetric measurement is very expensive, and it is recommended that this procedure must be repeated at least once a year. Thus, this work developed a methodology for the entire dosimetric process. This methodology is based on the scarce information available in the literature, once almost all the methodology used in large industrial laboratories is commercial secret. The proposed methodology was tested using seeds of Amersham-Oncura-Ge Healthcare, which is the largest seed manufactory in the world. In this new methodology, an automatic reader was employed in order to reduce the time required in the selection process of the TLD-100 dosimeters used and a postprocessing of the obtained spectra was carried out. A total of 142 dosimeters were used and only 29 have been selected using the new methodology. Measurements were performed using slabs of Solid Water RW1 to simulate measuring in the 'water', using three different experimental apparatus and each measurement was repeated at least three times. The TLD-100 calibration was performed using a Dermopan II - Siemens. The measured values showed a good agreement with the ones available in the literature. Finally, these measured values were compared with calculated ones obtained by a semiempirical simulation program, showing a good agreement and, therefore, demonstrating the validity of the proposed methodology regarding dosimetric calculations. (author)

  8. 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)

  9. Pedicle versus free flap reconstruction in patients receiving intraoperative brachytherapy.

    Science.gov (United States)

    Geiger, Erik J; Basques, Bryce A; Chang, Christopher C; Son, Yung; Sasaki, Clarence T; McGregor, Andrew; Ariyan, Stephan; Narayan, Deepak

    2016-08-01

    Introduction This study compared complication rates between pedicle flaps and free flaps used for resurfacing of intraoperative brachytherapy (IOBT) implants placed following head and neck tumour extirpation to help clarify the ideal reconstructive procedure for this scenario. Patients and methods A retrospective review of reconstructions with IOBT at our institution was conducted. Patient and treatment details were recorded, as were the number and type of flap complications, including re-operations. Logistic regressions compared complications between flap groups. Results Fifty free flaps and 55 pedicle flaps were included. On multivariate analysis, free flap reconstruction with IOBT was significantly associated with both an increased risk of having any flap complication (OR = 2.9, p = 0.037) and with need for operative revision (OR = 3.5, p = 0.048) compared to pedicle flap reconstruction. Conclusions In the setting of IOBT, free flaps are associated with an increased risk of having complications and requiring operative revisions. PMID:26983038

  10. A Prospective Quasi-Randomized Comparison of Intraoperatively Built Custom-Linked Seeds Versus Loose Seeds for Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To compare dosimetric parameters, seed migration rates, operation times, and acute toxicities of intraoperatively built custom-linked (IBCL) seeds with those of loose seeds for prostate brachytherapy. Methods and Materials: Participants were 140 patients with low or intermediate prostate cancer prospectively allocated to an IBCL seed group (n=74) or a loose seed group (n=66), using quasirandomization (allocated by week of the month). All patients underwent prostate brachytherapy using an interactive plan technique. Computed tomography and plain radiography were performed the next day and 1 month after brachytherapy. The primary endpoint was detection of a 5% difference in dose to 90% of prostate volume on postimplant computed tomography 1 month after treatment. Seed migration was defined as a seed position >1 cm from the cluster of other seeds on radiography. A seed dropped into the seminal vesicle was also defined as a migrated seed. Results: Dosimetric parameters including the primary endpoint did not differ significantly between groups, but seed migration rate was significantly lower in the IBCL seed group (0%) than in the loose seed group (55%; P<.001). Mean operation time was slightly but significantly longer in the IBCL seed group (57 min) than in the loose seed group (50 min; P<.001). No significant differences in acute toxicities were seen between groups (median follow-up, 9 months). Conclusions: This prospective quasirandomized control trial showed no dosimetric differences between IBCL seed and loose seed groups. However, a strong trend toward decreased postimplant seed migration was shown in the IBCL seed group

  11. Is a Loose-Seed Nomogram Still Valid for Prostate Brachytherapy in a Stranded-Seed Era?

    International Nuclear Information System (INIS)

    Purpose: To characterize the amount of activity required to treat the prostate with stranded 125I radioactive seeds and compare our stranded data with the amount of activity recommended when individual seeds are implanted using a Mick applicator. Methods and Materials: Data from two groups of patients at University of Texas M. D. Anderson Cancer Center who were treated with prostate brachytherapy as monotherapy were analyzed. The first group included 100 patients implanted with individual seeds in 2000 and 2001. The second group comprised 81 patients for whom stranded seeds were implanted in 2006 and 2007. Seeds in both groups were 125I seeds with an air kerma strength of 0.497 U per seed (0.391 mCi per seed). The prescribed dose to planning target volume was 145 Gy. Results: The total implanted activity and the number of seeds used were significantly lower in the second group (p 3 prostate and approximately 15% for a 60-cm3 prostate. With equivalent activity between the two groups, the stranded-seed treatment covered a larger treatment volume with the prescribed dose. Conclusions: The amount of activity required to effectively treat a prostate of a given volume was lower with stranded seeds than with loose seeds. Our experience suggests that prostate brachytherapy that uses stranded seeds leads to a more efficient implant with fewer seeds and lower overall activity, resulting in improved homogeneity

  12. Studies on the development of 169Yb-brachytherapy seeds: New generation brachytherapy sources for the management of cancer

    International Nuclear Information System (INIS)

    This paper describes development of 169Yb-seeds by encapsulating 0.6–0.65 mm (ϕ) sized 169Yb2O3 microspheres in titanium capsules. Microspheres synthesized by a sol–gel route were characterized by XRD, SEM/EDS and ICP-AES. Optimization of neutron irradiation was accomplished and 169Yb-seeds up to 74 MBq of 169Yb could be produced from natural Yb2O3 microspheres, which have the potential for use in prostate brachytherapy. A protocol to prepare 169Yb-brachytherapy sources (2.96–3.7 TBq of 169Yb) with the use of enriched targets was also formulated

  13. Incidence of seed migration to the chest, abdomen, and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds

    International Nuclear Information System (INIS)

    The aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds. We reviewed the records of 267 patients who underwent prostate brachytherapy with loose 125I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration. A total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration. We showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90

  14. WE-A-17A-11: Implanted Brachytherapy Seed Movement Due to Transrectal Ultrasound Probe-Induced Prostate Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D; Usmani, N; Sloboda, R [Cross Cancer Institute, Edmonton, Alberta (Canada); University of Alberta, Edmonton, Alberta (Canada); Meyer, T; Husain, S; Angyalfi, S [Tom Baker Cancer Centre, Calgary, Alberta (Canada); University of Calgary, Calgary, Alberta (Canada); Kay, I [Canterbury District Health Board, Christchurch (New Zealand)

    2014-06-15

    Purpose: To characterize the movement of implanted brachytherapy seeds due to transrectal ultrasound probe-induced prostate deformation and to estimate the effects on prostate dosimetry. Methods: Implanted probe-in and probe-removed seed distributions were reconstructed for 10 patients using C-arm fluoroscopy imaging. The prostate was delineated on ultrasound and registered to the fluoroscopy seeds using a visible subset of seeds and residual needle tracks. A linear tensor and shearing model correlated the seed movement with position. The seed movement model was used to infer the underlying prostate deformation and to simulate the prostate contour without probe compression. Changes in prostate and surrogate urethra dosimetry were calculated. Results: Seed movement patterns reflecting elastic decompression, lateral shearing, and rectal bending were observed. Elastic decompression was characterized by anterior-posterior expansion and superior-inferior and lateral contractions. For lateral shearing, anterior movement up to 6 mm was observed for extraprostatic seeds in the lateral peripheral region. The average intra-prostatic seed movement was 1.3 mm, and the residual after linear modeling was 0.6 mm. Prostate D90 increased by 4 Gy on average (8 Gy max) and was correlated with elastic decompression. For selected patients, lateral shearing resulted in differential change in D90 of 7 Gy between anterior and posterior quadrants, and increase in whole prostate D90 of 4 Gy. Urethra D10 increased by 4 Gy. Conclusion: Seed movement upon probe removal was characterized. The proposed model captured the linear correlation between seed movement and position. Whole prostate dose coverage increased slightly, due to the small but systematic seed movement associated with elastic decompression. Lateral shearing movement increased dose coverage in the anterior-lateral region, at the expense of the posterior-lateral region. The effect on whole prostate D90 was smaller due to the subset

  15. WE-A-17A-11: Implanted Brachytherapy Seed Movement Due to Transrectal Ultrasound Probe-Induced Prostate Deformation

    International Nuclear Information System (INIS)

    Purpose: To characterize the movement of implanted brachytherapy seeds due to transrectal ultrasound probe-induced prostate deformation and to estimate the effects on prostate dosimetry. Methods: Implanted probe-in and probe-removed seed distributions were reconstructed for 10 patients using C-arm fluoroscopy imaging. The prostate was delineated on ultrasound and registered to the fluoroscopy seeds using a visible subset of seeds and residual needle tracks. A linear tensor and shearing model correlated the seed movement with position. The seed movement model was used to infer the underlying prostate deformation and to simulate the prostate contour without probe compression. Changes in prostate and surrogate urethra dosimetry were calculated. Results: Seed movement patterns reflecting elastic decompression, lateral shearing, and rectal bending were observed. Elastic decompression was characterized by anterior-posterior expansion and superior-inferior and lateral contractions. For lateral shearing, anterior movement up to 6 mm was observed for extraprostatic seeds in the lateral peripheral region. The average intra-prostatic seed movement was 1.3 mm, and the residual after linear modeling was 0.6 mm. Prostate D90 increased by 4 Gy on average (8 Gy max) and was correlated with elastic decompression. For selected patients, lateral shearing resulted in differential change in D90 of 7 Gy between anterior and posterior quadrants, and increase in whole prostate D90 of 4 Gy. Urethra D10 increased by 4 Gy. Conclusion: Seed movement upon probe removal was characterized. The proposed model captured the linear correlation between seed movement and position. Whole prostate dose coverage increased slightly, due to the small but systematic seed movement associated with elastic decompression. Lateral shearing movement increased dose coverage in the anterior-lateral region, at the expense of the posterior-lateral region. The effect on whole prostate D90 was smaller due to the subset

  16. Iodine-125 thin seeds decrease prostate swelling during transperineal interstitial permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Prostate swelling following seed implantation is a well-recognised phenomenon. The purpose of this intervention was to assess whether using thinner seeds reduces post-implant swelling with permanent prostate brachytherapy. Eighteen consecutive patients eligible for prostate seed brachytherapy underwent seed implantation using iodine-125 (I-125) thin seeds. Operative time, dosimetry, prostate swelling and toxicity were assessed and compared with standard I-125 stranded seed controls, sourced from the department's brachytherapy database. A learning curve was noted with the thin seeds in terms of greater bending and deviation of needles from their intended path. This translated into significantly longer total operative time (88 vs 103 minutes; P=0.009, 95% confidence interval (CI) 4.1-24.3) and time per needle insertion (2.6 vs 3.7 minutes; P<0.001, 95% CI 0.5-1.3) for the thin seeds. Day 30 prostate volumes were significantly smaller in the thin seed group compared with standard seeds (40.9cc vs 46.8cc; P=0.001, 95% CI 1.5-5.6). The ratio of preoperative transrectal ultrasound to day 30 post-implant CT volume was also smaller in the thin seed group (1.2±0.1 for standard seeds vs 1.1±0.1 for thin seeds). Post-implant dosimetric parameters were comparable for both groups. No significant differences were seen in acute urinary morbidity or quality of life between the two groups. I-125 thin seeds are associated with an initial learning curve, with longer operative time, even for experienced brachytherapists. The significant reduction in day 30 prostate volumes with the thin seeds has useful implications in terms of optimising dose coverage to the prostate in the early period post-implantation, as well as improving the accuracy of post-implant dosimetric assessments.

  17. Production of Pd 103 seed from Rh targets for brachytherapy

    International Nuclear Information System (INIS)

    The suitability of a given radionuclide for brachytherapy is determined by its half-life, the type of energy, and abundance (number per decay) of its emission. The half-life of a radionuclide must be long enough to permit shipping and implant preparation with an acceptable loss of source strength due to decay, but it must also be short enough to permit source sizes sufficiently small for the intended application. Pd-103 is a low energy photon emitter available for permanent interstitial implantation. Pd-103 has energy and safety characteristics similar to I-125, but its initial peripheral dose rate is approximately three times greater. This may provide improved control of rapidly proliferating tumours. Although Pd-103 has been used for various kinds of cancers, it is almost exclusively used for prostate cancer, the most common cancer, and the death rate from this cancer is the highest. There are two cyclotron production routes for Pd-103, Ag (p,xn) 103 Pd and Rh (p,n) 103 Pd. For a cyclotron with low energy (such as 30Mev that we have in Iran, Karaj, NRCAM) only Rh target can be used. The target material should be deposited on a special designed Cu substrate and the separation process should isolate the desired radionuclide from target material as well as Cu. Our work plan for production of Pd 103 in Karaj, Iran, is as follows: In the first year of the CRP we are going to complete the literature survey of Pd production and perform the relevant experiments as described later. In the second year of the CRP we will construct suitable hot cells for Pd production and also do research for development of Pd seeds. In the last year of the CRP we are going to finalise all the work done during the last two years and propose the automation system for routine production

  18. [Brachytherapy].

    Science.gov (United States)

    Itami, Jun

    2014-12-01

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

  19. Preparation and deployment of indigenous 125I- seeds for the treatment of prostate cancer: dawn of prostate brachytherapy in India

    International Nuclear Information System (INIS)

    'Permanent seed implantation' using 125I- seeds represents an effective treatment modality for prostate cancer. An innovative strategy to prepare and deploy 125I- seeds for treatment of prostate cancer has been evolved. Seeds prepared by chemisorptions of 125I on palladium coated silver wires were characterized and encased in titanium tubes by ND:YAG laser. Several batches of critically evaluated seeds exhibiting release of 125I were supplied to P.D. Hinduja Hospital, Mumbai for treatment of prostate cancer patients. Successful deployment of indigenous seeds in prostate brachytherapy has opened a new window for making prostate brachytherapy affordable to needy cancer patients. (author)

  20. Investigation of palladium-103 production and IR07-103Pd brachytherapy seed preparation

    International Nuclear Information System (INIS)

    Highlights: → We report the cyclotron production of 103-palladium via 103Rh(p,n)103Pd reaction. → 103Pd was absorbed on resin beads for brachytherapy seed preparation. → The optimum absorption of 103Pd in resin was achieved at 0.5 M HCl. → Version 5 of MCNP code was employed to model a new 103Pd brachytherapy seed. - Abstract: In this study, design and fabrication of 103Pd brachytherapy seed was investigated. The excitation functions of 103Rh(p,n)103Pd and 103Rh(d,2n)103Pd reactions were calculated using EMPIRE (version 3.1 Rivoli), ALICE/ASH and TALYS-1.2 codes, the TENDL-2010 database and compared with the published data. Production of 103Pd was done via 103Rh(p,n)103Pd nuclear reaction. The target was bombarded with 18 MeV protons at 200 μA beam current for 15 h. After irradiation and radiochemical separation of the electroplated rhodium target, the optimum condition for absorption of 103Pd into Amberlite (registered) IR-93 resin was achieved at 0.5 M HCl. Version 5 of the (MCNP) Monte Carlo radiation transport code was employed to calculate the dosimetric parameters around the 103Pd brachytherapy seed. Finally the calculated results were compared with published results for other commercial sources.

  1. COMS eye plaque brachytherapy dosimetric sensitivity to source photon energy and seed design

    International Nuclear Information System (INIS)

    This study explores the influence of source photon energy on eye plaque brachytherapy dose distributions for a 16 mm COMS plaque filled with 103Pd, 125I, or 131Cs sources or monoenergetic photon emissions ranging from 12 keV to 100 keV. Dose distributions were similarly created for all permutations of three common brachytherapy seed designs. Within this range, sources with average energy ≤22 keV may reduce dose to the opposite eye wall by more than a factor of 2 while maintaining tolerable proximal sclera doses when prescribing to depths of 9 mm or less. Current commercially-available brachytherapy sources can exhibit up to 15% relative dosimetric sensitivity to seed design at regions within the eye. - Highlights: • Episcleral eye plaque brachytherapy utilizes low-energy photon-emitting sources. • Dose distribution sensitivity to source photon energy and seed design was examined. • Tumor dose conformity and critical structure sparing from ≤22 keV photons is preferred. • Ocular dose distributions varied by up to 15% with seed design permutations

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

    Science.gov (United States)

    Metyko, John; Erwin, William; Landsberger, Sheldon

    2016-06-01

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

  3. Iodine-125 Seed Implantation (Permanent Brachytherapy for Clinically Localized Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Saika,Takeshi

    2008-02-01

    Full Text Available From January 2004 to March 2007, 308 patients with clinically localized prostate cancer were treated using iodine-125 (125I seed implantation (permanent brachytherapy at Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences. We evaluated the treatment’s effi cacy and morbidity in 300 prostate cancer patients who were followed up for more than 1 month after brachytherapy. Based on the National Comprehensive Cancer Network (NCCN guidelines, patients with a prostate volume of less than 40 ml in transrectal ultrasound imaging were classifi ed as low or intermediate risk. The median patient age was 67 years (range 50 to 79 years, the median prostate-specific antigen (PSA value before biopsy was 6.95 ng/ml (range 1.13 to 24.7 ng/ml, and the median prostate volume was 24.33 ml (range 9.3 to 41.76 ml. The median follow-up was 18 months (range 1 to 36 months and the PSA levels decreased in almost all patients after brachytherapy. Although 194 of 300 patients (64.7% complained of diffi culty in urination, pollakisuria/urgency, miction pain, and/or urinary incontinence, all of which might be associated with radiation prostatitis during the fi rst month after brachytherapy, these symptoms gradually improved. 125I seed implantation brachytherapy is safe and eff ective for localized prostate cancer within short-term follow up.

  4. Migration of a strand of four seeds in low-dose-rate brachytherapy

    Science.gov (United States)

    Dedic-Hagan, Jasmina; Teh, Amy Y M; Liang, Eisen; Collett, Nicholas; Woo, Henry H

    2014-01-01

    We report a case of stranded-seed migration (one strand of four seeds), via the prostatic venous plexus to the internal pudendal vein, in low-dose-rate (LDR) prostate brachytherapy. A 70-year-old man with low-risk prostate adenocarcinoma underwent transperineal permanent seed implantation. A total of 93 iodine-125 seeds were implanted (91 stranded seeds and 2 loose seeds). Immediate postimplantation fluoroscopic image and day 1 postimplantation CT scan indicated all implanted seeds to be within the vicinity of the prostate as planned. Day 30 pelvic X-ray and CT scan revealed migration of a strand of four seeds to the right pelvis (adjacent to ischial spine). At 2 years postimplantation, the patient continues to have good disease control with prostate specific antigen level of 0.69 μg/L, and asymptomatic. To the best of our knowledge, this is the first report of migration of an entire strand of seeds following LDR prostate brachytherapy. PMID:24879735

  5. Computational Program of Isodose and TPS of 125I Seed for Brachytherapy

    International Nuclear Information System (INIS)

    Radioactive sources are widely used in several fields including for medical purposes. One use of radioactive sources in medical field is radiotherapy to cure the cancerous organs. Brachytherapy term is the radiotherapy where the radiation source is placed inside or as close as possible to the cancer needing treatment. In order to support the domestic application of 125I seeds in brachytherapy, a computational program for isodose and TPS (Treatment Planning System) calculation shall be available. The preparation of the such program has been successfully developed using Microsoft Visual Basic for Windows and its supporting tools. This program can display the two-dimensions-isodose contour of 1-20 125I seeds presented in direction of lateral, anterior (AP) and caodal. The dose rate at the distances of 1, 2, 3 and 4 cm from the center point assumed as (0,0) can also be calculated from 1 to 360 days after implantation of the 125I seeds. The entered data as well as the resulting calculation and the contour presentation can be saved and be quickly traced and redisplayed at any time necessarily. This computer program is hopefully able to assist physicians in the implementation of 125I seeds implantation for brachytherapy. (author)

  6. Fast radioactive seed localization in intraoperative cone beam CT for low-dose-rate prostate brachytherapy

    Science.gov (United States)

    Hu, Yu-chi; Xiong, Jian-ping; Cohan, Gilad; Zaider, Marco; Mageras, Gig; Zelefsky, Michael

    2013-03-01

    A fast knowledge-based radioactive seed localization method for brachytherapy was developed to automatically localize radioactive seeds in an intraoperative volumetric cone beam CT (CBCT) so that corrections, if needed, can be made during prostate implant surgery. A transrectal ultrasound (TRUS) scan is acquired for intraoperative treatment planning. Planned seed positions are transferred to intraoperative CBCT following TRUS-to-CBCT registration using a reference CBCT scan of the TRUS probe as a template, in which the probe and its external fiducial markers are pre-segmented and their positions in TRUS are known. The transferred planned seeds and probe serve as an atlas to reduce the search space in CBCT. Candidate seed voxels are identified based on image intensity. Regions are grown from candidate voxels and overlay regions are merged. Region volume and intensity variance is checked against known seed volume and intensity profile. Regions meeting the above criteria are flagged as detected seeds; otherwise they are flagged as likely seeds and sorted by a score that is based on volume, intensity profile and distance to the closest planned seed. A graphical interface allows users to review and accept or reject likely seeds. Likely seeds with approximately twice the seed volume are automatically split. Five clinical cases are tested. Without any manual correction in seed detection, the method performed the localization in 5 seconds (excluding registration time) for a CBCT scan with 512×512×192 voxels. The average precision rate per case is 99% and the recall rate is 96% for a total of 416 seeds. All false negative seeds are found with 15 in likely seeds and 1 included in a detected seed. With the new method, updating of calculations of dose distribution during the procedure is possible and thus facilitating evaluation and improvement of treatment quality.

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

    International Nuclear Information System (INIS)

    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 the isocenter as much as possible. This method could be used

  8. Iodine-125 prostate seed brachytherapy in renal transplant recipients: an analysis of oncological outcomes and toxicity profile

    OpenAIRE

    Beydoun, Nadine; Bucci, Joseph; Malouf, David

    2014-01-01

    Purpose Prostate cancer is among the most common non-cutaneous neoplasms affecting renal transplant recipients (RTRs). Available treatments including radical prostatectomy and external beam radiotherapy carry a risk of damage to the transplanted kidney, ureters, or bladder. We assessed the safety and efficacy of Iodine-125 (125I) prostate seed brachytherapy as an alternative to surgery and radiotherapy in these individuals. Material and methods We retrospectively reviewed our brachytherapy da...

  9. Permanent brachytherapy challenges and solutions : new plastic radioactive seeds and interseed effect correction for online prostate treatment dosimetry

    OpenAIRE

    Abboud, Fadi

    2011-01-01

    The overall subject of this work was the dosimetric study of new, low energy photon sealed sources made of polymer for clinical brachytherapy application. A key goal was to resolve the problem of inaccuracies in real-time dosimetry that occur as a result of self-shielding by seeds (interseed effect), which is neglected by current treatment planning systems (TPS). Permanent brachytherapy implantation has become a popular treatment option in the management of early stage prostate cancer. Adj...

  10. Seed loss in prostate brachytherapy. Operator dependency and impact on dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    El-Bared, Nancy; Sebbag, Natanel; Beliveau-Nadeau, Dominic; Hervieux, Yannick; Larouche, Renee; Taussky, Daniel; Delouya, Guila [Centre hospitalier de l' Universite de Montreal - Hopital Notre-Dame, Departement de Radio-Oncologie, Montreal, QC (Canada)

    2016-05-15

    The aim of our study was to review seed loss and its impact on dosimetry as well as the influence of the treating physician on seed loss and dosimetry in patients treated with prostate brachytherapy using permanent loose {sup 125}I implant. We analyzed 1087 consecutive patients treated by two physicians between July 2005 and April 2015 at a single institution. Pelvic fluoroscopic imaging was done 30 days post implant and a chest X-ray when seed loss was observed. Seed loss occurred in 19.4 % of patients: in 20.0 % of implants done by the most experienced physician and in 17.2 % by the less experienced physician (p = 0.4) and migration to the thorax occurred in 5.9 % (6.9 vs. 2.2 %, p = 0.004). The mean seed loss rate was 0.57 % [standard deviation (SD) 1.39] and the mean rate of seeds in the thorax was 0.14 % (SD 0.65). The most experienced physician had a higher mean number of seeds lost: 0.36 versus 0.25 (p = 0.055), and a higher mean number of seed migration to the thorax: 0.1 versus 0.02 (p < 0.001). When at least one seed was lost, a decrease of 4.2 Gy (p < 0.001) in the D90 and a decrease of 3.5 % (p = 0.002) in the V150 was observed. We found a significant decrease in V150 and D90 with the occurrence of seed loss. Furthermore, we found a difference in seed migration among the physicians demonstrating that seed loss is operator dependant. (orig.) [German] Wir analysierten den Prozentsatz des Seed-Verlusts sowie den Einfluss von Arzterfahrung und Seed-Abgang auf die Dosimetrie bei Patienten, die mit einer Prostata-Brachytherapie mit permanent beweglichen {sup 125}I-Implantaten behandelt wurden. Eingeschlossen in diese Studie wurden alle zwischen Juli 2005 und April 2015 an unserem Krankenhaus von zwei Aerzten konsekutiv behandelten 1087 Patienten. Anhand fluoroskopischer Bilder wurden noch vorhandene Seeds 30 Tage nach dem Eingriff gezaehlt. Bei unvollstaendiger Seed-Anzahl wurde ein Thorax-Roentgenbild angefertigt. In 19% der Patienten ging mindestens ein

  11. Dosimetric aspects of 166Ho brachytherapy biodegradable glass seed

    International Nuclear Information System (INIS)

    The purpose of this study is to perform absorbed dose calculations based on Monte Carlo simulations for a novel beta emitter bioglass Ho-166 seed which is proposed for treating small hepatocellular carcinomas (HCCs). The bioactive glass seed has been developed by use of the sol–gel method. Monte Carlo simulations were carried out for the seed using the version 5 of the (MCNP) Monte Carlo radiation transport code to investigate the dosimetric parameters recommended by the AAPM Task Group 60 (TG-60). Dose distributions due to the beta and photon radiation were obtained at different radial distances surrounding the source. The dose rate in water at the reference point was calculated to be 6.71±0.4 cGy h−1 μCi−1. The anisotropy function values ranging from 0.745 to 1.928 were obtained for radial distances of 0.3–8 mm and polar angles of 0°–90°. The 166Ho seed source can deliver high radiation doses to the tumor, while the short range of the beta particles limits damage to the adjacent normal tissue. - Highlights: ► A beta emitter bioglass Ho-166 seed has been proposed for treating small HCC tumors. ► The MCNP5 code was used to investigate dose distributions around the seed. ► The dosimetric parameters recommended by the AAPM Task Group 60 (TG-60) were calculated. ► The short range of the beta particles limits damage to the normal tissues

  12. Development of an Iridium-192 seed for use in ophthalmic brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Fabio R.; Rostelato, Maria Elisa C.M.; Zeituni, Carlos; Moura, Joao A.; Costa, Osvaldo L.; Feher, Anselmo; Moura, Eduardo S.; Souza, Carla D.; Peleias Junior, Fernando S., E-mail: frmattos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The Institute for Energy and Nuclear Research (IPEN), in partnership with the School or Medicine (UNIFESP), created a project that aims to develop and implement an ophthalmic therapeutic treatment for cancer with Iridium-192 seeds. The School of Medicine treats many cancer cases in the SUS (Brazilian Public Health System), and brachytherapy group of IPEN has extensive experience in prototype sources. The seed to be manufactured will perform as follows: a core of Iridium-192 is packaged inside small cylindrical seeds consist of a titanium capsule of 0.8 mm outer diameter, 0.05 mm wall thickness and 4 5 mm in length. The core is an alloy of platinum-iridium (20/80) of 3.0 mm in length and 0.3 mm in diameter. Material analysis, neutron activation and activity measurements were carried out. (author)

  13. Production of 125I seed sources for brachytherapy uses

    International Nuclear Information System (INIS)

    The production of radioactive sources of 125I, used mainly for the brachytherapy of prostate and ocular cancer, is a work that is being carried out in the plant of production of radioisotopes (PPR) of the Nuclear Center Racso of the IPEN. The employed methodology is based on the 125I physical-chemistry adsorption at silver wires coated with palladium. In the realization of the tests, it has been considered the procedure used by India and Iran participants of this CRP. In the execution of this work, the 131I radioisotope is been used simulating the 125I, because in the PPR-IPEN we produce the 131I. In total 50 samples were used, they were divided in ten groups. In first place with nine working groups, the optimum conditions for work for the coating of the silver wires with palladium were obtained, these being the following: simple method, employing PdCl2 0.1 m, pH of 5.5 to 6.5 and a temperature of 100 deg. C. Later on, a series of tests were carried out to determine the appropriate parameters for the adsorption of 131I in the previously treated wires, these being the following: carrier concentration of Ki 0.03 m, time of adsorption of 6 hours, and temperature of 70 deg. C. Finally, the percentage of 131I adsorption was obtained in the silver wires tried previously with palladium chloride solution of 98.24%. The control of leachability was made, having very good results. To confirm these previously mentioned parameters, a test was made with ten pieces of silver wires, corresponding to the group 10, giving the confirmation as a result of these. Also, samples of the titanium tube have been sent for test with microplasma welding to a French company: air welding liquidates export. With these results obtained, subsequently the production of these radioactive sources will be carried out employing 125I as a radioisotope. (author)

  14. Evaluation of physician eye lens doses during permanent seed implant brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Treatment of low grade prostate cancer with permanent implant of radioactive seeds has become one of the most common brachytherapy procedures in use today. The implant procedure is usually performed with fluoroscopy image guidance to ensure that the seeds are deployed in the planned locations. In this situation the physician performing the transperineal implant is required to be close to the fluoroscopy unit and dose to the eye lens may be of concern. In 1991 the International Commission on Radiological Protection (ICRP) provided a recommended dose limit of 150 mSv yr−1 for occupational exposures to the lens of the eye. With more long term follow-up data, this limit was revised in 2011 to 20 mSv yr−1. With this revised limit in mind, we have investigated the dose to the lens of the eye received by physicians during prostate brachytherapy seed implantation. By making an approximation of annual workload, we have related the dose received to the annual background dose. Through clinical and phantom measurements with thermoluminescent dosimeters, it was found that the excess dose to the physician’s eye lens received for a conservative estimate of annual workload was never greater than 100% of the annual background dose. (paper)

  15. 125I seed implant brachytherapy for the treatment of parotid gland cancers in children and adolescents

    International Nuclear Information System (INIS)

    Background and purpose: There is a lack of optimal treatment strategies for managing salivary gland cancers in children and adolescents. This study is aimed at assessing the effect of 125I seed implantation for the treatment of parotid cancers in children and adolescents. Patients and methods: A total of 12 patients younger than 16 years with parotid gland malignant tumors underwent 125I seed implant brachytherapy between October 2003 and November 2008. All patients were assessed after treatment and at the local tumor control appointments. Facial nerve function, maxillofacial development, and radioactive side-effects were assessed. Results: The follow-up period ranged from 41-104 months. One patient with T4b died of pulmonary metastasis. The other patients were alive during the follow-up period. There were no serious radiation-related complications. The treatment did not affect facial nerve function and dentofacial growth in any of the children. Conclusion: For parotid gland cancers in children, 125I seed implant brachytherapy may be an acceptable treatment without serious complications and with satisfactory short-term effects. (orig.)

  16. Recognition of Radiological Protection of Ward Staff after Brachytherapy for Malignant Tumor with Radioiodine Seeds

    Directory of Open Access Journals (Sweden)

    HU Shu

    2016-02-01

    Full Text Available Through radiation measurement of the patients after brachytherapy with radioiodine seeds for malignant tumor at different distances and shielding condition, the importance, optimization and individualization of the radiological protection are well recognized. The 35 patients were randomly selected in the minimally invasive interventional ward of Peking University Shenzhen Hospital who underwent brachytherapy for malignant tumor with radioiodine seeds. Within 2 hours after the brachytherapy, the radiation of the patients without shielding, with 0.25 mmPb and 0.5 mmPb shielding were detected by an x-γ ray detector at different distances (equivalent dose rate. The results were analysed by SPSS19.0 t test. Annual equivalent dose was calculated by the average close contact time (two hours everyone per day. The average annual equivalent dose of the 35 patients without shielding was below 20 mSv at 0.5 meter, close to the public limit 1 mSv at 2 meters and equivalent to the background at 4 meters. Under 0.25 mmPb shielding, 6 patients’ radiation was still above the pubic limit, although the average radiation of the 35 patients was below the pubic limit; under 0.5 mmPb shielding, all patients’ radiation was nearly equivalent to the background at 0 meter. The results showed that among the time, distance and shielded protection, the individual radiological protection was especially important. The 0.25 mmPb lead cushion was the most commonly used shield. The 0.5 mmPb lead cushion also should be used in case of the large number of radioiodine seeds implantation and/or more superficial implant site, so as to ensure the individualization and optimization in radiological protection.

  17. Radiation exposure to operating room staff during prostate brachytherapy using iodine-125 seeds

    International Nuclear Information System (INIS)

    The French defense radiation protection service (SPRA) and the French national institute for research and safety (INRS) conducted a joint study to assess the radiation exposure to operating room staff during prostate brachytherapy using iodine-125 seeds at the Val-de-Grace military hospital. The purpose of the study was the assessment of the effective doses, the equivalent doses to the extremities and lens received by a novice team, the different ambient dose equivalent rates measurements and the delineation of areas. After six brachy-therapies, all the recorded doses with whole-body InLightR OSL and nanoDotR dosimeters remained below the detection limit for the whole staff. The dose rate measured at the end of implantation by an AT1123R survey meter is about 170 μSv/h at the perineum of the patient. The controlled area limit is estimated to be about 20 cm from the patient perineum. From these results, the authors propose recommendations for the categorization of workers, the delineation of areas and the dose monitoring procedures. This study demonstrates that real-time ultrasound-guided trans-perineal prostate brachytherapy delivers low dose to the operators because of the radioactive source characteristics and the instrumentation providing an effective radiation protection for the surgical team. (authors)

  18. Brachytherapy with Iodine-125 seeds in initial prostate cancer treatment: preliminary results and complications

    International Nuclear Information System (INIS)

    Low-dose rate brachytherapy as monotherapy is a treatment option for early stage prostate cancer. It consists of the permanent implantation of Iodine-125 seeds in the gland of patients with PSA≤ 10ng/ml, Gleason ≤ 6 and clinical stage from T1 until T2b. The 68 patients enrolled in this study were treated by the technique developed at the Northwest Pacific Hospital, Seattle, USA. Sixty four patients treated with low-dose rate brachytherapy were followed for 4-48 months (median = 32 months). The treatment results were based on the periodic evaluation of the total PSA values and it was found that, after this time, 55% of patients had total PSA equal or below 1ng/ml. Post-implant morbidities were evaluated, showing that 89% presented negligible or low grade side effects. Low-dose rate brachytherapy is an appealing option for the treatment of early stage prostate cancer because of its successful local control and low morbidity. (author)

  19. Späte Seed-Migration nach LDR-Brachytherapie der Prostata mit I125-Permanentimplantaten

    Directory of Open Access Journals (Sweden)

    Maletzki P

    2015-01-01

    Full Text Available Hintergrund: Nach einer „Lowdose-rate“- (LDR Brachytherapie der Prostata kommt es häufig zu einer Seed-Migration. Trotz mehrerer Arbeiten über eine Seed-Migration in der frühen postoperativen Phase nach Seed-Implantation gibt es bisher nur wenige Daten über eine Seed-Migration mehrere Jahre nach erfolgter Intervention. Unser Ziel war eine Datenerhebung zur Inzidenz, Lokalisation, Symptomatik und therapeutischen Konsequenz einer späten Seed-Migration 3 Jahre nach Seed-Implantation. Methoden: Wir untersuchten retrospektiv 63 unselektionierte Patienten, die mittels transrektaler, Ultraschall-gesteuerter, transperinealer interstitieller LDR-Brachytherapie der Prostata zwischen 2001 und 2010 behandelt wurden. Es wurden hierbei verknüpfte („stranded“ Seeds verwendet. Am ersten Tag nach der Intervention erfolgte eine Symphysenzielaufnahme und 6 Wochen postoperativ eine erneute Symphysenzielaufnahme in Kombination mit einem CT/MRI des Beckens mit Bildfusionstechnik zur dosimetrischen Untersuchung. Die radiologische Spätkontrolle wurde mehr als 3 Jahre postoperativ mittels einer Symphysenzielaufnahme und eines Thorax-Röntgens durchgeführt. Ergebnisse: Mehr als 3 Jahre nach Brachytherapie zeigten 36 der 63 Patienten (57 % einen Seed-Verlust. Die Anzahl fehlender Seeds lag zwischen 1 und 9. Neben einer frühen Seed-Migration zeigte sich eine späte Seed-Migration bei 2 der 36 Patienten (6 % mit Migration in die Lunge, Leber und das kleine Becken. Alle Spätmigrationen waren asymptomatisch und ohne therapeutische Konsequenz. Diskussion: Neben häufig auftretenden Seed-Verlusten scheint eine Seed-Migration mehrere Jahre nach erfolgter Implantation eine seltene Erscheinung zu sein. Langzeitkontrollen mit ergänzenden radiologischen Nachuntersuchungen könnten dennoch hilfreich zur Dokumentation einer relevanten Seed-Migration sein.

  20. Characterization of the susceptibility artifact around a prostate brachytherapy seed in MRI

    International Nuclear Information System (INIS)

    Magnetic distortions surrounding a typical brachytherapy seed (IMC6711, OncoSeedTM) within a clinical magnetic resonance imager were modeled for a number of different seed orientations with respect to the main magnetic field. From these distortion maps, simulated images were produced. The simulated images were then compared to images experimentally acquired using a spin echo technique on a Philips 1.5 T magnetic resonance imaging scanner. The modeled images were found to conform very well to those acquired experimentally, thus allowing one to establish where the seed is positioned within the complex image distortion patterns. The artifact patterns were dependent on the orientation of the seed with the main magnetic field, as well as the direction of the read encode gradient. While all imaging schemes which employ a unidirectional linear read encode trajectory should produce the artifacts modeled in this article, sequences other than spin echo may produce additional artifacts. Gradient echo and steady-state free precession imaging techniques were also performed on the seed for comparison

  1. Required treatment margin for coronary endovascular brachytherapy with iridium-192 seed ribbon

    International Nuclear Information System (INIS)

    Purpose: Preliminary clinical trials (SCRIPPS I, WRIST and Gamma 1) employing catheter-based endovascular brachytherapy (EVBT) with iridium-192 (Ir-192) seeds show promising results in reducing restenosis after coronary intervention. Failure analysis of these studies showed a significant number of restenosis at the treatment margin called ''edge effect.'' The objective of this study is to investigate the factors that contribute to the adequacy of treatment margin. Methods and materials: The factors contributing to the margins are penumbra effect at the end of the seed train, uncertainty in target localization, longitudinal seed movement during cardiac cycle and barotrauma due to stent deployment. The magnitudes of the penumbra effect, which refers to the tapering off the prescribed isodose line near the ends of the source train, were calculated for various source lengths of Ir-192 seed ribbon using AAPM TG-43 algorithm. Uncertainty in target localization refers to the fact that the visual estimation of proximal and distal extent of the injury is not accurate, and this can be obtained by comparing the 'estimate' from the interventional cardiologist with careful review of the cine-angiogram. Longitudinal seed movements relative to the coronary vessel during the cardiac cycle were determined by frame-by-frame reviewing cine-angiograms of 30 patients. The proximal and distal source points were measured in reference to branching vessels during the contrast phase of the cine-angiogram. The maximum proximal and distal longitudinal movement was captured and source displacement was measured from the closest proximal and distal branching vessel. Barotrauma, additional injury to the vessel arising from the stent deployment balloon, was obtained by reviewing specifications from commercially available stent delivery systems. Results: The penumbra effect ranges from 3.9 to 4.5 mm for 6-22 Ir-192 seed ribbons. The uncertainty in target localization is within 3 mm for our

  2. The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy

    International Nuclear Information System (INIS)

    Background and purpose: A geometric check procedure of the reconstruction techniques used in brachytherapy treatment planning systems was developed by the EQUAL (European Quality Laboratory) Laboratory in the framework of the ESTRO's (European Society for Therapeutic Radiology and Oncology) project 'ESQUIRE' (Education Science and QUality assurance In Radiotherapy in Europe [Baumann M, Brada M. Towards equity in turbulent Europe ESTRO, European cooperation and the European Commission. Radiother Oncol 2005;75:251-2. Heeren G. The bright but ephemeral life of a rainbow. A chronical of seventeen years of intensive ESTRO-EU cooperation. Radiother Oncol 2005;75:253-7]) by the task group Braphyqs (Brachytherapy physics quality system). Patients and methods: The check is performed by using the so-called 'Baltas' phantom, mailed to the participating centres in order to check the local technique of geometric reconstruction used in dose calculation. Results: To validate the procedures, the check was first tested among the members of the Braphyqs Network. Since November 2002, the system is open to other centres. Until now 152 reconstructions have been checked. Eighty-six percent of the results were within an acceptance level after the first check. For the remaining 14%, a second check has been proposed. The results of the re-checks are in most cases within an acceptance level, except for 2% of the reconstructions. Conclusions: The geometric check is available from the EQUAL Laboratory for all the brachytherapy centres. The decrease of the deviations observed between the two checks demonstrates the importance of this kind of external audit as some errors were revealed, which were not discovered before with techniques used in clinical quality control routines

  3. Dosimetry on ocular brachytherapy with ROPES plaque with Iodine-125 and Palladium-103 seeds

    International Nuclear Information System (INIS)

    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 model of ocular area was developed to simulate orbital irradiation with ROPES ophthalmologic plaque placed on the sclera surface filled to ten iodine-125 seeds, and palladium-103 seeds. 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 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. (author)

  4. Characterization of ceramic seeds with samarium-153 for use in brachytherapy

    Directory of Open Access Journals (Sweden)

    Eduardo Sarmento Valente

    2011-03-01

    Full Text Available Ceramic seeds were synthesized by the sol-gel technique with Si:Sm:Ca. One sample was irradiated in the TRIGA nuclear reactor IPR-R1. After irradiation, the seeds were submitted to instrumental neutron activation analysis to determine the 153Sm concentration in weight. The same irradiated seed sample was submitted to gamma spectrometry analysis to determine all existing radionuclides as well as its individual activities. A second sample was submitted to ICP-AES atomic emission spectrometry. A third sample was submitted to X-ray fluorescence spectrometry to determine qualitative chemical composition. The measured activity was due to 153Sm with a well-characterized gamma spectrum. The X-ray fluorescence spectrum demonstrates that there is no discrepancy in seed composition. Maximum range of beta particles from 153Sm were evaluated, as well as the total dose and dose rate on its range´s volume. The results are relevant for investigation of the viability of producing 153Sm radioactive seeds for use in brachytherapy.

  5. SU-E-J-233: Effect of Brachytherapy Seed Artifacts in T2 and Proton Density Maps in MR Images

    International Nuclear Information System (INIS)

    Purpose: This study aims at investigating the influence of brachytherapy seeds on T2 and proton density (PD) maps generated from MR images. Proton density maps can be used to extract water content. Since dose absorbed in tissue surrounding low energy brachytherapy seeds are highly influenced by tissue composition, knowing the water content is a first step towards implementing a heterogeneity correction algorithm using MR images. Methods: An LDR brachytherapy (IsoAid Advantage Pd-103) seed was placed in the middle of an agar-based gel phantom and imaged using a 3T Philips MR scanner with a 168-channel head coil. A multiple echo sequence with TE=20, 40, 60, 80, 100 (ms) with large repetition time (TR=6259ms) was used to extract T2 and PD maps. Results: Seed artifacts were considerably reduced on T2 maps compared to PD maps. The variation of PD around the mean was obtained as −97% to 125% (±1%) while for T2 it was recorded as −71% to 24% (±1%). Conclusion: PD maps which are required for heterogeneity corrections are susceptible to artifacts from seeds. Seed artifacts on T2 maps, however, are significantly reduced due to not being sensitive to B0 field variation

  6. SU-E-J-233: Effect of Brachytherapy Seed Artifacts in T2 and Proton Density Maps in MR Images

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S [Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); University of Toronto, Dept of Radiation Oncology, Toronto, Ontario (Canada); Fatemi-Ardekani, A [Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Sunnybrook Research Institute, Toronto, Ontario (Canada); Song, W [Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); University of Toronto, Dept of Radiation Oncology, Toronto, Ontario (Canada); Sunnybrook Research Institute, Toronto, Ontario (Canada)

    2015-06-15

    Purpose: This study aims at investigating the influence of brachytherapy seeds on T2 and proton density (PD) maps generated from MR images. Proton density maps can be used to extract water content. Since dose absorbed in tissue surrounding low energy brachytherapy seeds are highly influenced by tissue composition, knowing the water content is a first step towards implementing a heterogeneity correction algorithm using MR images. Methods: An LDR brachytherapy (IsoAid Advantage Pd-103) seed was placed in the middle of an agar-based gel phantom and imaged using a 3T Philips MR scanner with a 168-channel head coil. A multiple echo sequence with TE=20, 40, 60, 80, 100 (ms) with large repetition time (TR=6259ms) was used to extract T2 and PD maps. Results: Seed artifacts were considerably reduced on T2 maps compared to PD maps. The variation of PD around the mean was obtained as −97% to 125% (±1%) while for T2 it was recorded as −71% to 24% (±1%). Conclusion: PD maps which are required for heterogeneity corrections are susceptible to artifacts from seeds. Seed artifacts on T2 maps, however, are significantly reduced due to not being sensitive to B0 field variation.

  7. Study of dose deposition of 125I brachytherapy seeds in a solid water phantom

    International Nuclear Information System (INIS)

    Currently, many kinds of radioactive sources are used in brachytherapy for cancer treatment. The 125I seed used in this work is the model Onco Seed 6711, produced by Oncura, which is ranked among the best options for treating prostate cancer. This source emits gamma photons with average energy of 28 keV and has a half-life of 59.4 days. After the implants, the natural movement of the organ can cause the seeds undergo slight displacements relative to the position originally planned, which can cause changes in dose distribution in the tumor volume. This work seeks to compare the dose distribution in a solid water phantom of two symmetrical, but different arrangements of four seeds. For this study, the phantom was machined to accommodate the seeds and TLD-100 LiF rod type dosimeters. The study, using TLD dosimeters, was conducted up to 4 cm of the settings. In addition, an Ebt Gafchromic radiochromic film was positioned over the two configurations during a period of time enough for 1 Gy deposition on it, to observe possible changes in the shape of the isodose curves. The TLD results showed a difference up to 35.8% of the dose deposited in the center of the configurations and different doses were deposited at distances corresponding to 1 and 2 cm radius from the symmetrical seeds arrangements. After 3 cm radius, the dose discrepancy is no longer significant. Another important point is that despite the configurations are symmetric, different dose values were deposited at symmetrical points. The isodose qualitative curves shown by the films showed a difference in the shape of that curves. Thus, the different positions of the seeds proved decisive in dose deposition and this fact should be taken into consideration in planning treatment

  8. Prostate brachytherapy

    Science.gov (United States)

    Implant therapy - prostate cancer; Radioactive seed placement; Internal radiation therapy - prostate; High dose radiation (HDR) ... Brachytherapy takes 30 minutes or more, depending on the type of therapy you have. Before the procedure, ...

  9. Brachytherapy with permanent gold grain seeds for squamous cell carcinoma of the lip

    International Nuclear Information System (INIS)

    Purpose: To describe the use of radioactive gold grain implantation for squamous cell carcinoma of the lip. Methods: Retrospective review of 51 patients treated with permanent gold (198Au) grain implant brachytherapy. The seed arrangement delivered a dose of 5500 cGy at 0.5 cm from a single plane. Primary endpoints were local recurrence and cosmetic outcome. Results: Median follow-up was 27 months. Median age was 69 years. The majority (90%) were T1 lesions. None of the patients had evidence of regional lymph node or distant metastasis. Twelve patients had recurrent disease with prior surgery and five patients had previous head and neck radiation. Local control was achieved in 49 patients. Good cosmesis was achieved in 48 patients. Two-year actuarial estimates for local failure-free survival, disease-free survival and overall survival were 97.9%, 94.1% and 87.9%, respectively; no deaths were attributable to lip cancer. Conclusions: Gold grain interstitial low-dose rate brachytherapy provides excellent local control and cosmesis in patients with squamous cell carcinoma of the lip. This technique provides an excellent option for patients that are elder or live remotely. It is particularly useful for lesions that are small, in previously radiated areas, or treated with prior surgery.

  10. SU-E-T-362: Automatic Catheter Reconstruction of Flap Applicators in HDR Surface Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Buzurovic, I; Devlin, P; Hansen, J; O' Farrell, D; Bhagwat, M; Friesen, S; Damato, A; Lewis, J; Cormack, R [Dana-Farber/Brigham and Women' s Cancer Center, Harvard Medical School, Boston, MA (United States)

    2014-06-01

    Purpose: Catheter reconstruction is crucial for the accurate delivery of radiation dose in HDR brachytherapy. The process becomes complicated and time-consuming for large superficial clinical targets with a complex topology. A novel method for the automatic catheter reconstruction of flap applicators is proposed in this study. Methods: We have developed a program package capable of image manipulation, using C++class libraries of The-Visualization-Toolkit(VTK) software system. The workflow for automatic catheter reconstruction is: a)an anchor point is placed in 3D or in the axial view of the first slice at the tip of the first, last and middle points for the curved surface; b)similar points are placed on the last slice of the image set; c)the surface detection algorithm automatically registers the points to the images and applies the surface reconstruction filter; d)then a structured grid surface is generated through the center of the treatment catheters placed at a distance of 5mm from the patient's skin. As a result, a mesh-style plane is generated with the reconstructed catheters placed 10mm apart. To demonstrate automatic catheter reconstruction, we used CT images of patients diagnosed with cutaneous T-cell-lymphoma and imaged with Freiburg-Flap-Applicators (Nucletron™-Elekta, Netherlands). The coordinates for each catheter were generated and compared to the control points selected during the manual reconstruction for 16catheters and 368control point Results: The variation of the catheter tip positions between the automatically and manually reconstructed catheters was 0.17mm(SD=0.23mm). The position difference between the manually selected catheter control points and the corresponding points obtained automatically was 0.17mm in the x-direction (SD=0.23mm), 0.13mm in the y-direction (SD=0.22mm), and 0.14mm in the z-direction (SD=0.24mm). Conclusion: This study shows the feasibility of the automatic catheter reconstruction of flap applicators with a high

  11. Comparative dosimetry of prostate brachytherapy with I-125 and Pd-103 seeds via SISCODES/MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Bruno Machado; Falcao, Patricia Lima, E-mail: bmtrindade@yahoo.com [Nucleo de Radiacoes Ionizantes - Universidade Federal de Minas Gerais (NRI/UFMG), Belo Horizonte, MG (Brazil); Christovao, Marilia Tavares [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Trindade, Daniela de Fatima Maia [Centro Universitario Una, Belo Horizonte, MG (Brazil); Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2012-09-15

    Objective: The present paper is aimed at presenting a comparative dosimetric study of prostate brachytherapy with I-125 and Pd-103 seeds. Materials and Methods: A protocol for both implants with 148 seeds was simulated on a heterogeneous three-dimensional pelvic phantom by means of the SISCODES/MCNP5 codes. Dose-volume histograms on prostate, rectum and bladder, dose indexes D10, D30, D90, D0.5cc, D2cc and D7cc, and representations of the spatial dose distribution were evaluated. Results: For a D90 index equivalent to the prescription dose, the initial activity of each I-125 seed was calculated as 0.42 mCi and of Pd-103 as 0.94 mCi. The maximum dose on the urethra was 90% and 108% of the prescription dose for I-125 and Pd-103, respectively. The D2cc for I-125 was 30 Gy on the rectum and 127 Gy on the bladder; for Pd-103 was 29 Gy on the rectum and 189 Gy on the bladder. The D10 on the pubic bone was 144 Gy for I-125 and 66 Gy for Pd-103. Conclusion: The results indicate that Pd-103 and I-125 implants could deposit the prescribed dose on the target volume. Among the findings of the present study, there is an excessive radiation exposure of the pelvic bones, particularly with the I-125 protocol. (author)

  12. Development and characterisation of iridium-192 seeds for brachytherapy treatment of ocular tumors

    International Nuclear Information System (INIS)

    Even ocular tumors are not amongst the cases with a high incidence, they affect the population, particularly children. The Institute of Energy and Nuclear Research (IPEN-CNEN/SP) in partnership with Escola Paulista de Medicina (UNIFESP), created a project to develop an alternative treatment for ophthalmic cancer that uses iridium-192 seeds in brachytherapy. This work aims to study and develop a seed of iridium-192 from a platinum-iridium alloy The prototype seed has a 3.0 mm long core sealed by a titanium capsule of 0.8 mm of outer diameter, 0.05 mm of wall thickness and 4.5 mm long. We developed a methodology that covered: characterisation of the material used in the core, creation of a device for neutron activation of the cores and leakage tests. The results show that this methodology is feasible. As a suggestion for future work, studies regarding metrology and dosimetry of these sources should be carried out. (authors)

  13. Development of an encapsulation method using plasma arc welding to produce iodine-125 seeds for brachytherapy

    International Nuclear Information System (INIS)

    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)

  14. 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)

  15. Development of automated measurement system for radioactive intensities of sealed small radiation sources (iodine-125 seed source) for brachytherapy

    International Nuclear Information System (INIS)

    We have developed full automated measurement system for radioactive intensities of sealed small radiation sources (iodine-125 seed source) for brachytherapy in this work. Today, quality assurance (QA) of I-125 seed radioactive sources for brachytherapy following AAPM (American Association of Physicists in Medicine) Society's guideline is one of important subjects for hospitals that operate on patients for prostate cancer and medical companies that manufacture and sell these radioactive sources. In order to survey defective seed products into all the number of I-125 seed sources (there are usually fifteen seeds, one seed of dimensions is 0.8 mm φ × 4.5 mm length) within a cartridge, we have applied the method of single slit collimator with moving a radiation detector to measure each radioactive intensity of these I-125 seeds. As a result, it was found that our developed system in the present work has good performance of surveying the defective products manufactured with radioactive intensities out of about ±15% error (p < 0.05). (author)

  16. Determination of the accuracy of implant reconstruction and dose delivery in brachytherapy in The Netherlands and Belgium

    International Nuclear Information System (INIS)

    Purpose: To gain insight into the accuracy of brachytherapy treatments, the accuracy of implant reconstruction and dose delivery was investigated in 33 radiotherapy institutions in The Netherlands and Belgium. Materials and methods: The accuracy of the implant reconstruction method was determined using a cubic phantom containing 25 spheres at well-known positions. Reconstruction measurements were obtained on 41 brachytherapy localizers, 33 of which were simulators. The reconstructed distances between the spheres were compared with the true distances. The accuracy of the dose delivery was determined for high dose rate (HDR), pulsed dose rate (PDR) and low dose rate (LDR) afterloading systems using a polymethyl methacrylate cylindrical phantom containing a NE 2571 ionization chamber in its centre. The institutions were asked to deliver a prescribed dose at the centre of the phantom. The measured dose was compared with the prescribed dose. Results: The average reconstruction accuracy was -0.07 mm (±0.4 mm, 1 SD) for 41 localizers. The average deviation of the measured dose from the prescribed dose was +0.9% (±1.3%, 1 SD) for 21 HDR afterloading systems, +1.0% (±2.3%, 1 SD) for 12 PDR afterloaders, and +1.8% (±2.5%, 1 SD) for 15 LDR afterloaders. Conclusions: This comparison showed a good accuracy of brachytherapy implant reconstruction and dose delivery in The Netherlands and Belgium

  17. Dosimetric studies, spectrometric, radiographic, metallographic of a new argentinean seed of 125 I used in brachytherapy

    International Nuclear Information System (INIS)

    A new source of 125 I model BraquibacTM has been developed in Argentina for applications in interstitial brachytherapy. The AAPM Task Group 43 (TG-43) recommends that dosimetric characteristics of new sources of brachytherapy of Iodine-125 have been theoretically and experimentally determined before its clinical use. The objectives outlined in this work were the study of the design of the new seed, the calculation of dosimetric parameters and the photons spectra analysis. Its were carried out radiographic and metallographic studies to determine the physical characteristics of the source. For the realization of the dosimetric calculations it was used the Monte Carlo code MCNP5. Values of the radial dose function, g(r), of the constant of dose rate, Λ, of the function of anisotropy of two dimensions, F(r, θ), of the factor and constant of anisotropy its were obtained simulating the source in water according to the recommended methodology in TG-43. The constant of dose rate is similar to 0,880 ± 0,080 c Gy h-1 U-1. The kerma in air rate of reference, SK, was calculated as 1,036 c Gy cm2h-1 mCi-1 simulating the seed in dry air. Its were carried out spectrometric studies using a semiconductor planar detector of HPGe (high purity germanium). Photons spectra showed characteristic x-rays of 125 I with energies of 27,20 keV, 27,47 keV, 31 keV and 31,70 keV gamma photons of 35,5 keV, and x-ray fluorescent coming from the silver nucleus of 22,10 keV, 24,94 keV and 25,45 keV. The angular dependence of the intensity of photons around the seed and in air it was analyzed with the planar detector. This was carried out to study the anisotropy in the photons flow due to variation in the thickness of the titanium wall and of the welding, movements of the silver tube inside the source and deposition of the radioactive material on the silver tube. (Author)

  18. CT-guidance interstitial 125Iodine seed brachytherapy as a salvage therapy for recurrent spinal primary tumors

    OpenAIRE

    Cao, Qianqian; Wang, Hao; Meng, Na; Jiang, Yuliang; Jiang, Ping; Gao, Yang; Tian, Suqing; Liu, Chen; Yang, Ruijie; Wang, Junjie; Zhang, Kaixian

    2014-01-01

    Background Management of spinal neoplasms has relied on open surgery and external beam radiotherapy (EBRT). Although primary spinal tumors are rare, their treatment remains a pervasive problem. This analysis sought to evaluate the safety and efficacy of CT-guided 125I seed brachytherapy for recurrent paraspinous and vertebral primary tumors. Methods From November 2002 to June 2014, 17 patients who met the inclusion criteria were retrospectively reviewed. 14 (82.4%) had previously undergone su...

  19. Dosimetric results in implant and post-implant and low rate in brachytherapy prostate cancer with loose seeds and attached

    International Nuclear Information System (INIS)

    The objective is determine differences dosimetry statistics on the dosimetry of the implant and post-implant in brachytherapy of low rate with implants permanent in prostate using seed of 125-I loose and attached Both in lives and in the post-prostatic plans dosimetric coverage is good and restrictions in urethra and rectum for both groups of patients are met. Not migrating with joined is evident, as well as better dosimetric homogeneity. (Author)

  20. Long-term erectile function following permanent seed brachytherapy treatment for localized prostate cancer

    International Nuclear Information System (INIS)

    Background and purpose: Erectile function (EF) is commonly affected following prostate cancer treatment. We aim to evaluate the long-term EF following seed brachytherapy (BT) treatment. Materials and methods: The study consisted of 366 patients treated with BT at our institution, who completed the IIEF-5 questionnaire and reported no or mild erectile dysfunction (ED) pre-BT. The probability of EF preservation post-BT was estimated using the Kaplan–Meier methods. The difference in EF preservation by patient-, tumour- and treatment-related factors was assessed using the log-rank test. Multivariate Cox regression was used to estimate the effect of each factor on EF preservation. Results: Of the 366 patients, 277 (76%) reported normal EF, and 89 (24%) reported mild ED. The patients were followed-up for a median of 41 months (range: 3–124), and the 5-year actuarial rate of EF preservation was 59%. Age at BT seed implant, presence of medical comorbidities, Gleason score and the biologically effective dose (BED) are associated with EF preservation (P < 0.005). The association for these four factors remains statistically significant in multivariate analysis, with Gleason score having the strongest effect (HR = 3.7; 95% CI = 2.6–5.4). Conclusion: The 5-year actuarial rate of EF preservation post-BT in our cohort is 59%, and is influenced by multiple factors

  1. MAGNETIC RESONANCE IMAGING COMPATIBLE ROBOTIC SYSTEM FOR FULLY AUTOMATED BRACHYTHERAPY SEED PLACEMENT

    Science.gov (United States)

    Muntener, Michael; Patriciu, Alexandru; Petrisor, Doru; Mazilu, Dumitru; Bagga, Herman; Kavoussi, Louis; Cleary, Kevin; Stoianovici, Dan

    2011-01-01

    Objectives To introduce the development of the first magnetic resonance imaging (MRI)-compatible robotic system capable of automated brachytherapy seed placement. Methods An MRI-compatible robotic system was conceptualized and manufactured. The entire robot was built of nonmagnetic and dielectric materials. The key technology of the system is a unique pneumatic motor that was specifically developed for this application. Various preclinical experiments were performed to test the robot for precision and imager compatibility. Results The robot was fully operational within all closed-bore MRI scanners. Compatibility tests in scanners of up to 7 Tesla field intensity showed no interference of the robot with the imager. Precision tests in tissue mockups yielded a mean seed placement error of 0.72 ± 0.36 mm. Conclusions The robotic system is fully MRI compatible. The new technology allows for automated and highly accurate operation within MRI scanners and does not deteriorate the MRI quality. We believe that this robot may become a useful instrument for image-guided prostate interventions. PMID:17169653

  2. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc, E-mail: Luc.Beaulieu@phy.ulaval.ca [Département de physique, de génie physique et d’optique et Centre de recherche sur le cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de radio-oncologie et Axe Oncologie du Centre de recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Binnekamp, Dirk [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best 5680 DA (Netherlands)

    2015-03-15

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora{sup ®} Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators.

  3. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    International Nuclear Information System (INIS)

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora® Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators

  4. Iodine-125 seed brachytherapy for early stage prostate cancer: a single-institution review

    International Nuclear Information System (INIS)

    We are reporting the five-year biochemical control, toxicity profile and dosimetric parameters using iodine-125 low dose rate brachytherapy (BT) as monotherapy for early stage prostate cancer at a single institution. Between April 2006 and December 2010, 169 men with early stage prostate cancer were treated with BT. Biochemical failure was defined using the Phoenix definition (nadir + 2 ng/mL). Treatment-related morbidities, including urinary, rectal and sexual function, were measured, applying the International Prostate Symptom Score (IPSS), the 7-grade Quality of Life Scale (QoL) and medical status, the International Consultation on Incontinence Modular Questionnaire (ICIQ), the International Index of Erectile Function (IIEF-5) and the Common Terminology Criteria for Adverse Events (CTCAE v4.03). Seed migration and loss, dosimetric parameters and learning effects were also analyzed. Medium follow-up time was 50 months (range, 1–85 months). The five-year biochemical failure rate was 7%. Acute proctitis rates were 19% (grade 1) and 1% (grade 2), respectively. The overall incidence of incontinence was 19% (mild), 16% (moderate) and < 1% (severe). An increase in IPSS ≥ 5 points was detected in 59% of patients, with 38% regaining their baseline. Seed dislocation was found in 24% of patients and correlated with D90 and V100. A learning curve was found for seed migration, D90 and V100. QoL correlated with the general health condition of patient, incontinence symptoms and IPSS. BT for early stage prostate cancer offers excellent five-year biochemical control with low toxicities. QoL aspects are favorable. A learning curve was detected for procedural aspects but its impact on patient relevant endpoints remains inconclusive

  5. A neutron activation system for Ho, HoZr and Sm brachytherapy seeds for breast radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Wagner L., E-mail: wagner.leite@ifmg.edu.br [Instituto Federal de Minas Gerais (IFMG), Congonhas, MG (Brazil). Departamento de Fisica; Campos, Tarcisio P.R., E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2015-07-01

    This paper addresses a device designed for transmuting nuclides by means of neutron capture reactions. The device is composed by a neutron generator based on d-d reactions, a neutron moderator and a reflection system, enclosed by a radiation shield. The project was modeled on the CST electromagnetic code. Afterwards, a nuclear investigation was carried out by MCNP5 code, where the final activities of a large set of 0.5 x 1.8 mm cylindrical, biodegradable and biocompatible, Ho-165 (Ho and HoZr) and Sm-152 breast brachytherapy seeds were evaluated, considering the neutron capture reactions. The accelerator-head equipotential profiles and the optical beam of deuterons with its energy map were presented. The neutronic evaluation allowed estimating a neutron yield of 10{sup 13} n s{sup -1}. From the seed's group, an individual Ho-166 seed reached activity of 100 MBq in 58 h operation time. Moreover, Sm-153 seed reached 120 MBq during a period of 64 h of operation. The system shows to be able to provide the neutron activation of brachytherapy seeds with suitable individual specific activity able for controlling breast tumors. (author)

  6. Preparation and deployment of indigenous 125I-seeds for the treatment of prostate cancer. Dawn of prostate brachytherapy in India

    International Nuclear Information System (INIS)

    'Permanent seed implantation' using 125I- seeds has emerged as an effective treatment modality for management of prostate cancer. An indigenous technology for the production of 125I brachytherapy sources ('BARC 125I Ocu-Prosta seed') has been developed. In this current work, we describe an overview of our experience on large scale production of 125I brachytherapy sources, their quality assessment, in vivo bio-evaluation and initial experience on their journey from bench to bed-side for the treatment of prostate cancer. (author)

  7. Narrow safety range of intraoperative rectal irradiation exposure volume for avoiding bleeding after seed implant brachytherapy

    International Nuclear Information System (INIS)

    Rectal toxicity is less common after 125I seed implant brachytherapy for prostate cancer, and intraoperative rectal dose-volume constraints (the constraint) is still undetermined in pioneering studies. As our constraint failed to prevent grade 2 or 3 rectal bleeding (bled-pts) in 5.1% of patients, we retrospectively explored another constraint for the prevention of rectal bleeding. The study population consisted of 197 patients treated with the brachytherapy as monotherapy using real-time intraoperative transrectal ultrasound (US)-guided treatment at a prescribed dose of 145 Gy. Post-implant dosimetry was performed on Day 1 and Day 30 after implantation using computed tomography (CT) imaging. Rectal bleeding toxicity was classified by CTC-AE ver. 3.0 during a mean 29-month (range, 12-48 months) period after implantation. The differences in rV100s were compared among intraoperative, Day 1 and Day 30 dosimetry, and between that of patients with grade 2 or 3 rectal bleeding (the bled-pts) and of the others (the spared-pts). All patients were divided into groups based on provisional rV100s that were increased stepwise in 0.1-cc increments from 0 to 1.0 cc. The difference in the ratios of the bled-pts to the spared-pts was tested by chi-square tests, and their odds ratios were calculated (bled-OR). All statistical analyses were performed by t-tests. The mean values of rV100us, rV100CT-1, and rV100CT-30 were 0.31 ± 0.43, 0.22 ± 0.36, and 0.59 ± 0.68 cc, respectively. These values temporarily decreased (p = 0.020) on Day 1 and increased (p = 0.000) on Day 30. There was no significant difference in rV100s between the bled-pts and spared-pts at any time of dosimetry. The maximum bled-OR was identified among patients with an rV100us value above 0.1 cc (p = 0.025; OR = 7.8; 95% CI, 1.4-145.8); an rV100CT-1 value above 0.3 cc (p = 0.014; OR = 16.2; 95% CI, 3.9-110.7), and an rV100CT-30 value above 0.5 cc (p = 0.019; OR = 6.3; 95% CI, 1.5-42.3). By retrospective analysis

  8. A proteomics analysis for certain signature proteins of rabbit lacrimal passages after 125I seeds brachytherapy

    International Nuclear Information System (INIS)

    To search for certain signature proteins and the expression profiles in lacrimal passage stenosis, rabbit models of lacrimal passage stenosis were treated by 125I seed brachytherapy. All the signature proteins were separated by two-dimensional electrophoresis, and identified by mass spectrometry. The results show that the up-regulated proteins are peptidyl-prolyl cis-trans isomerase A (PPIase A), and epidermal fatty acid-binding protein (E-FABP), while the down-regulated proteins are myosin light chain 1 (isomer of skeletal muscle), myosin light polypeptide 6 (isomer 1 of smooth muscle and non-muscle), myosin light chain 1 (isomer of slow-twitch muscle A), isomer 2 of ERC protein 2, and α-crystalline family protein. The proteins may play a role in healing the wound and regulating synaptic active zone of neurons due to correlation to cell apoptosis, proliferation and migration of smooth muscle cell. These provide molecular mechanism for preventing stenosis and restenosis of lacrimal passage. (authors)

  9. Surface treatments of silver rods with enhanced iodide adsorption for I-125 brachytherapy seeds

    International Nuclear Information System (INIS)

    This study described an effective method to load 125I on silver rods for the preparation of a brachytherapy source. We tested various ligands on the silver rod surface to screen the one with the highest adsorption and specific radioactivity. In addition, we investigated the effect of surface etching to increase the adsorption capability followed by the extended surface area. We also found that the use of an oxidant during iodide adsorption can increase the loading significantly. The maximum activity of 137.90 MBq/rod (3.7269 mCi/rod) was achieved on the etched silver rods with phosphate ligand and hydrogen peroxide as an oxidant. In addition, this is 4.5-fold higher than that of the conventional chloride treatment method. - Highlights: • Surface treatment of silver rods with several ligands was investigated to find optimum ligand for production of I-125 seeds. • Activity of adsorbed iodide was increased up to 499% on HNO3-etched rods compared to H2O-washed rods. • When H2O2 was used as an oxidant for surface-modification, the amount of adsorbed iodide was increased up to 589%. • Activity of adsorbed iodide exhibited the highest value (137.90 MBq/rod) on rods etched and treated with PO43− and H2O2

  10. Conventional Versus Automated Implantation of Loose Seeds in Prostate Brachytherapy: Analysis of Dosimetric and Clinical Results

    Energy Technology Data Exchange (ETDEWEB)

    Genebes, Caroline, E-mail: genebes.caroline@claudiusregaud.fr [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France); Filleron, Thomas; Graff, Pierre [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France); Jonca, Frédéric [Department of Urology, Clinique Ambroise Paré, Toulouse (France); Huyghe, Eric; Thoulouzan, Matthieu; Soulie, Michel; Malavaud, Bernard [Department of Urology and Andrology, CHU Rangueil, Toulouse (France); Aziza, Richard; Brun, Thomas; Delannes, Martine; Bachaud, Jean-Marc [Radiation Oncology Department, Institut Claudius Regaud, Toulouse (France)

    2013-11-15

    Purpose: To review the clinical outcome of I-125 permanent prostate brachytherapy (PPB) for low-risk and intermediate-risk prostate cancer and to compare 2 techniques of loose-seed implantation. Methods and Materials: 574 consecutive patients underwent I-125 PPB for low-risk and intermediate-risk prostate cancer between 2000 and 2008. Two successive techniques were used: conventional implantation from 2000 to 2004 and automated implantation (Nucletron, FIRST system) from 2004 to 2008. Dosimetric and biochemical recurrence-free (bNED) survival results were reported and compared for the 2 techniques. Univariate and multivariate analysis researched independent predictors for bNED survival. Results: 419 (73%) and 155 (27%) patients with low-risk and intermediate-risk disease, respectively, were treated (median follow-up time, 69.3 months). The 60-month bNED survival rates were 95.2% and 85.7%, respectively, for patients with low-risk and intermediate-risk disease (P=.04). In univariate analysis, patients treated with automated implantation had worse bNED survival rates than did those treated with conventional implantation (P<.0001). By day 30, patients treated with automated implantation showed lower values of dose delivered to 90% of prostate volume (D90) and volume of prostate receiving 100% of prescribed dose (V100). In multivariate analysis, implantation technique, Gleason score, and V100 on day 30 were independent predictors of recurrence-free status. Grade 3 urethritis and urinary incontinence were observed in 2.6% and 1.6% of the cohort, respectively, with no significant differences between the 2 techniques. No grade 3 proctitis was observed. Conclusion: Satisfactory 60-month bNED survival rates (93.1%) and acceptable toxicity (grade 3 urethritis <3%) were achieved by loose-seed implantation. Automated implantation was associated with worse dosimetric and bNED survival outcomes.

  11. Permanent 125I-seed prostate brachytherapy: early prostate specific antigen value as a predictor of PSA bounce occurrence

    Directory of Open Access Journals (Sweden)

    Mazeron Renaud

    2012-03-01

    Full Text Available Abstract Purpose To evaluate predictive factors for PSA bounce after 125I permanent seed prostate brachytherapy and identify criteria that distinguish between benign bounces and biochemical relapses. Materials and methods Men treated with exclusive permanent 125I seed brachytherapy from November 1999, with at least a 36 months follow-up were included. Bounce was defined as an increase ≥ 0.2 ng/ml above the nadir, followed by a spontaneous return to the nadir. Biochemical failure (BF was defined using the criteria of the Phoenix conference: nadir +2 ng/ml. Results 198 men were included. After a median follow-up of 63.9 months, 21 patients experienced a BF, and 35.9% had at least one bounce which occurred after a median period of 17 months after implantation (4-50. Bounce amplitude was 0.6 ng/ml (0.2-5.1, and duration was 13.6 months (4.0-44.9. In 12.5%, bounce magnitude exceeded the threshold defining BF. Age at the time of treatment and high PSA level assessed at 6 weeks were significantly correlated with bounce but not with BF. Bounce patients had a higher BF free survival than the others (100% versus 92%, p = 0,007. In case of PSA increase, PSA doubling time and velocity were not significantly different between bounce and BF patients. Bounces occurred significantly earlier than relapses and than nadir + 0.2 ng/ml in BF patients (17 vs 27.8 months, p Conclusion High PSA value assessed 6 weeks after brachytherapy and young age were significantly associated to a higher risk of bounces but not to BF. Long delays between brachytherapy and PSA increase are more indicative of BF.

  12. Permanent 125I-seed prostate brachytherapy: early prostate specific antigen value as a predictor of PSA bounce occurrence

    International Nuclear Information System (INIS)

    To evaluate predictive factors for PSA bounce after 125I permanent seed prostate brachytherapy and identify criteria that distinguish between benign bounces and biochemical relapses. Men treated with exclusive permanent 125I seed brachytherapy from November 1999, with at least a 36 months follow-up were included. Bounce was defined as an increase ≥ 0.2 ng/ml above the nadir, followed by a spontaneous return to the nadir. Biochemical failure (BF) was defined using the criteria of the Phoenix conference: nadir +2 ng/ml. 198 men were included. After a median follow-up of 63.9 months, 21 patients experienced a BF, and 35.9% had at least one bounce which occurred after a median period of 17 months after implantation (4-50). Bounce amplitude was 0.6 ng/ml (0.2-5.1), and duration was 13.6 months (4.0-44.9). In 12.5%, bounce magnitude exceeded the threshold defining BF. Age at the time of treatment and high PSA level assessed at 6 weeks were significantly correlated with bounce but not with BF. Bounce patients had a higher BF free survival than the others (100% versus 92%, p = 0,007). In case of PSA increase, PSA doubling time and velocity were not significantly different between bounce and BF patients. Bounces occurred significantly earlier than relapses and than nadir + 0.2 ng/ml in BF patients (17 vs 27.8 months, p < 0.0001). High PSA value assessed 6 weeks after brachytherapy and young age were significantly associated to a higher risk of bounces but not to BF. Long delays between brachytherapy and PSA increase are more indicative of BF

  13. An innovative seeding technique for photon conversion reconstruction at CMS

    CERN Document Server

    Giordano, Domenico

    2012-01-01

    The conversion of photons into electron-positron pairs in the detector material is a nuisance in the event reconstruction of high energy physics experiments, since the measurement of the electromagnetic component of interaction products results degraded. Nonetheless this unavoidable detector effect can be also extremely useful. The reconstruction of photon conversions can be used to probe the detector material and to accurately measure soft photons that come from radiative decays in heavy flavor physics. In fact a converted photon can be measured with very high momentum resolution by exploiting the excellent reconstruction of charged tracks of a tracking detector as the one of CMS at LHC. The main issue is that photon conversion tracks are difficult to reconstruct for standard reconstruction algorithms. They are typically soft and very displaced from primary interaction vertex. An innovative seeding technique that exploits the peculiar photon conversion topology, successfully applied in the ...

  14. Development of computational models for the simulation of isodose curves on dosimetry films generated by iodine-125 brachytherapy seeds

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Adriano M.; Meira-Belo, Luiz C.; Reis, Sergio C.; Grynberg, Suely E., E-mail: amsantos@cdtn.b [Center for Development of Nuclear Technology (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The interstitial brachytherapy is one modality of radiotherapy in which radioactive sources are placed directly in the region to be treated or close to it. The seeds that are used in the treatment of prostate cancer are generally cylindrical radioactive sources, consisting of a ceramic or metal matrix, which acts as the carrier of the radionuclide and as the X-ray marker, encapsulated in a sealed titanium tube. This study aimed to develop a computational model to reproduce the film-seed geometry, in order to obtain the spatial regions of the isodose curves produced by the seed when it is put over the film surface. The seed modeled in this work was the OncoSeed 6711, a sealed source of iodine-125, which its isodose curves were obtained experimentally in previous work with the use of dosimetric films. For the films modeling, compositions and densities of the two types of dosimetric films were used: Agfa Personal Monitoring photographic film 2/10, manufactured by Agfa-Geavaert; and the model EBT radiochromic film, by International Specialty Products. The film-seed models were coupled to the Monte Carlo code MCNP5. The results obtained by simulations showed to be in good agreement with experimental results performed in a previous work. This indicates that the computational model can be used in future studies for other seeds models. (author)

  15. {sup 125}I seed implant brachytherapy for the treatment of parotid gland cancers in children and adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Zhang, J.; Song, T.; Zhang, J.; Yu, G.; Zhang, Y. [Peking University School and Hospital of Stomatology, Beijing (China). Dept. of Oral and Maxillofacial Surgery

    2013-05-15

    Background and purpose: There is a lack of optimal treatment strategies for managing salivary gland cancers in children and adolescents. This study is aimed at assessing the effect of {sup 125}I seed implantation for the treatment of parotid cancers in children and adolescents. Patients and methods: A total of 12 patients younger than 16 years with parotid gland malignant tumors underwent {sup 125}I seed implant brachytherapy between October 2003 and November 2008. All patients were assessed after treatment and at the local tumor control appointments. Facial nerve function, maxillofacial development, and radioactive side-effects were assessed. Results: The follow-up period ranged from 41-104 months. One patient with T4b died of pulmonary metastasis. The other patients were alive during the follow-up period. There were no serious radiation-related complications. The treatment did not affect facial nerve function and dentofacial growth in any of the children. Conclusion: For parotid gland cancers in children, {sup 125}I seed implant brachytherapy may be an acceptable treatment without serious complications and with satisfactory short-term effects. (orig.)

  16. The Quadrella: A novel approach to analyzing optimal outcomes after permanent seed prostate brachytherapy

    International Nuclear Information System (INIS)

    Background and purpose: To study a four-point combined analysis (Quadrella) of optimal outcome among patients treated with exclusive permanent seed prostate brachytherapy (PB), as defined by the likelihood of achieving disease control and preserving normal urinary, gastro-intestinal (GI) and sexual function. Materials and methods: 384 patients with localized prostate cancer underwent PB at our institution with 125I at a dose level of 144 Gy. Subjects with erectile dysfunction who did not respond to medication were excluded. 281 patients with minimum 3-year follow-up were evaluated. Patients with concurrent biochemical progression-free survival (bPFS), absent urinary and GI toxicities (grade 0 toxicities according to CTCAE v 3.0) and preserved sexual potency (with our without medication) were classified as the Quadrella group. Results: Among the 281 patients analyzed, the Quadrella was achieved in 49.1%, 48.0%, 50.4%, 41.7% and 65.2% in years 3–7, respectively. bPFS rates were 82.6–96.1%, corresponding potency rates were 63.6–82.3%, and normal urinary and GI function rates were 64.8–82.6% and 95–100%, respectively. By multivariate analysis, significant predictors of Quadrella were age (p = 0.015), baseline IPSS (p = 0.03) and time since PB (p = 0.02). Conclusion: Urinary and sexual toxicity remained the most common reasons for excluding patients from a perfect outcome (Quadrella), defined by strict criteria. This analysis can be useful for subsequent comparison between treatment modalities

  17. Urethra-Sparing, Intraoperative, Real-Time Planned, Permanent-Seed Prostate Brachytherapy: Toxicity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zilli, Thomas [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada); Taussky, Daniel, E-mail: daniel.taussky.chum@ssss.gouv.qc.ca [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada); Donath, David; Le, Hoa Phong; Larouche, Renee-Xaviere; Beliveau-Nadeau, Dominique; Hervieux, Yannick; Delouya, Guila [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal-Hopital Notre-Dame, Montreal, QC (Canada)

    2011-11-15

    Purpose: To report the toxicity outcome in patients with localized prostate cancer undergoing {sup 125}I permanent-seed brachytherapy (BT) according to a urethra-sparing, intraoperative (IO), real-time planned conformal technique. Methods and Materials: Data were analyzed on 250 patients treated consecutively for low- or intermediate-risk prostate cancer between 2005 and 2009. The planned goal was urethral V{sub 150} = 0. Acute and late genitourinary (GU), gastrointestinal (GI), and erectile toxicities were scored with the International Prostate Symptom Score (IPSS) questionnaire and Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time for patients with at least 2 years of follow-up (n = 130) was 34.4 months (range, 24-56.9 months). Results: Mean IO urethra V{sub 150} was 0.018% {+-} 0.08%. Mean prostate D{sub 90} and V{sub 100} on day-30 computed tomography scan were 158.0 {+-} 27.0 Gy and 92.1% {+-} 7.2%, respectively. Mean IPSS peak was 9.5 {+-} 6.3 1 month after BT (mean difference from baseline IPSS, 5.3). No acute GI toxicity was observed in 86.8% of patients. The 3-year probability of Grade {>=}2 late GU toxicity-free survival was 77.4% {+-} 4.0%, with Grade 3 late GU toxicity encountered in only 3 patients. Three-year Grade 1 late GI toxicity-free survival was 86.1% {+-} 3.2%. No patient presented Grade {>=}2 late GI toxicity. Of patients with normal sexual status at baseline, 20.7% manifested Grade {>=}2 erectile dysfunction after BT. On multivariate analysis, elevated baseline IPSS (p = 0.016) and high-activity sources (median 0.61 mCi) (p = 0.033) predicted increased Grade {>=}2 late GU toxicity. Conclusions: Urethra-sparing IO BT results in low acute and late GU toxicity compared with the literature. High seed activity and elevated IPSS at baseline increased long-term GU toxicity.

  18. Urethra-Sparing, Intraoperative, Real-Time Planned, Permanent-Seed Prostate Brachytherapy: Toxicity Analysis

    International Nuclear Information System (INIS)

    Purpose: To report the toxicity outcome in patients with localized prostate cancer undergoing 125I permanent-seed brachytherapy (BT) according to a urethra-sparing, intraoperative (IO), real-time planned conformal technique. Methods and Materials: Data were analyzed on 250 patients treated consecutively for low- or intermediate-risk prostate cancer between 2005 and 2009. The planned goal was urethral V150 = 0. Acute and late genitourinary (GU), gastrointestinal (GI), and erectile toxicities were scored with the International Prostate Symptom Score (IPSS) questionnaire and Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time for patients with at least 2 years of follow-up (n = 130) was 34.4 months (range, 24–56.9 months). Results: Mean IO urethra V150 was 0.018% ± 0.08%. Mean prostate D90 and V100 on day-30 computed tomography scan were 158.0 ± 27.0 Gy and 92.1% ± 7.2%, respectively. Mean IPSS peak was 9.5 ± 6.3 1 month after BT (mean difference from baseline IPSS, 5.3). No acute GI toxicity was observed in 86.8% of patients. The 3-year probability of Grade ≥2 late GU toxicity-free survival was 77.4% ± 4.0%, with Grade 3 late GU toxicity encountered in only 3 patients. Three-year Grade 1 late GI toxicity-free survival was 86.1% ± 3.2%. No patient presented Grade ≥2 late GI toxicity. Of patients with normal sexual status at baseline, 20.7% manifested Grade ≥2 erectile dysfunction after BT. On multivariate analysis, elevated baseline IPSS (p = 0.016) and high-activity sources (median 0.61 mCi) (p = 0.033) predicted increased Grade ≥2 late GU toxicity. Conclusions: Urethra-sparing IO BT results in low acute and late GU toxicity compared with the literature. High seed activity and elevated IPSS at baseline increased long-term GU toxicity.

  19. An innovative seeding technique for photon conversion reconstruction at CMS

    International Nuclear Information System (INIS)

    The conversion of photons into electron-positron pairs in the detector material is a nuisance in the event reconstruction of high energy physics experiments, since the measurement of the electromagnetic component of interaction products results degraded. Nonetheless this unavoidable detector effect can also be extremely useful. The reconstruction of photon conversions can be used to probe the detector material and to accurately measure soft photons that come from radiative decays in heavy flavor physics. In fact a converted photon can be measured with very high momentum resolution by exploiting the excellent reconstruction of charged tracks of a tracking detector as the one of CMS at LHC. The main issue is that photon conversion tracks are difficult to reconstruct for standard reconstruction algorithms. They are typically soft and very displaced from the primary interaction vertex. An innovative seeding technique that exploits the peculiar photon conversion topology, successfully applied in the CMS track reconstruction sequence, is presented. The performances of this technique and the substantial enhancement of photon conversion reconstruction efficiency are discussed. Application examples are given.

  20. Obtention of brachytherapy seeds by sealing process using polymer; Obtencao de sementes de braquiterapia pelo processo de selagem com polimero

    Energy Technology Data Exchange (ETDEWEB)

    Lana, Diogo Alberto P.D.; Ferraz, Wilmar B.; Santos, Ana Maria M., E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Carvalho, Luiz Claudio F.M. Garcia [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2012-08-15

    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. 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 (titanium or stainless steel tube), a radionuclide carrier, and X-ray marker. The usual sealing process of the seeds is done with laser welding, but this process can promote radionuclide volatilization. In this paper, we present a new sealing process using epoxy resin and characterizations of two epoxy resins. These resins were characterized by Fourier transform infrared spectroscopic (FTIR), ultraviolet-visible spectroscopy (UV-vis) and differential scanning calorimetry (DSC). Interactions of the resins and of the sealed seeds in a simulated body fluid (SBF) were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and by a counting gamma-rays. (author)

  1. Study of Dosimetric and Thermal Properties of a Newly Developed Thermo-brachytherapy Seed for Treatment of Solid Tumors

    Science.gov (United States)

    Gautam, Bhoj R.

    Studies on the curative effects of hyperthermia and radiation therapy on treatment of cancer show strong evidence of synergistic enhancement when both radiation and hyperthermia treatment modalities are applied simultaneously. A variety of tissue heating approaches developed to date still fail to overcome essential limitations such as inadequate temperature control, temperature non-uniformity, and prolonged time delay between hyperthermia and radiation treatments. We propose a new self-regulating Thermo-brachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent administration of brachytherapy and hyperthermia. The proposed seed is based on the BestRTM Iodine-125 seed model 2301, where the tungsten marker core and the air gap are replaced with ferromagnetic material. The ferromagnetic core produces heat when subjected to an alternating electromagnetic (EM) field and effectively shuts off after reaching the Curie temperature (TC) of the ferromagnetic material, thus establishing temperature self-regulation. The seed has a ferromagnetic Ni-Cu alloy core having a Curie transition at a temperature of 52 °C. This study summarizes the design and development of the self regulating ferromagnetic core TB seed for the concurrent hyperthermia and brachytherapy treatments. An experimental study of the magnetic properties of the Ni1-xCu x (0.28≤ x ≤0.3) alloys, and the simulation studies of radiation and thermal distribution properties of the seed have been performed. A preliminary experiment for the ferromagnetic induction heating of Ni-Cu needles has been carried out to ensure the practical feasibility of the induction heating. Radiation dose characterizing parameters (dose rate constant and other TG-43 factors) were calculated using the Monte Carlo method. For the thermal characteristics, we studied a model consisting of single or multiple seeds placed in the central region of a cylindrical phantom using a finite-element analysis method

  2. Development of an automation system for iodine-125 brachytherapy seed production by ND:YAG laser welding

    International Nuclear Information System (INIS)

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices. The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a Programmable Logic Controller, a stepper motor, an Nd:YAG laser welding machine and a supervisory. (author)

  3. Development of an automation system for Iodine-125 brachytherapy seed encapsulated by Nd:YAG laser welding

    International Nuclear Information System (INIS)

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at Institute for Nuclear and Energy Research, Sao Paulo, Brazil (IPEN-CNEN/SP) imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a programmable logic controller (PLC), a stepper motor, an Nd:YAG laser welding machine and a supervisory. The statistical repeatability of correctly encapsulated sealed sources with this automation system is greater than 95%. (authors)

  4. Histology study on the dorsal root ganglia of rats with 125I seed brachytherapy at intervertebral foramen

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of the histological changes on rat dorsal root ganglia (DRG) after 125I seed brachytherapy.Methods Twelve adult male Sprague-Dawley rats (150-180 g each) were randomly divided into 6 groups,125I seeds with different activities of 0 (Titanium shell), 14.8, 18.5, 22.2, 25.9 and 29.6 MBq were implanted to 6 groups of rats respectively and the behavioral changes of rats were observed. The rats were killed in different periods after implantation,the morphological changes in DRG and surrounding muscle tissue were observed with an Olympus BX51 optical microscope and then the irradiation doses were estimated. Results: After 125I seed implantation, the movement function of rats was not affected and the weight of rats gained after 7 days. After the titanium shell implantation, very few mild swelling was induced in neuroganglion cells that still had clear nucleolus and normal cytoplasm. At 14 days after 18.5 MBq seed implantation, cell swelling was more serious and cell dehydrating, nuclear condensation and nuclear fragmentation appeared after 30 days. At 60 days after 29.6 MBq of seed implantation, nuclear dissolution and cytoplasmic shrinkage were induced in a large number of cells.In general, the severity of fibrosis was aggravated with the time post-irradiation and the dose in the muscles around the ganglion. Conclusions: After 125I seed implantation,the injury degree of DRG tissue is dose-dependent, and the 125I seed irradiation would have analgesic effect on releasing intractable pain. (authors)

  5. Development of an automation system for iodine-125 brachytherapy seed production by ND:YAG laser welding

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices. The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a Programmable Logic Controller, a stepper motor, an Nd:YAG laser welding machine and a supervisory. (author)

  6. Development of an automation system for iodine-125 brachytherapy seed production by (Nd:YAG) laser welding

    International Nuclear Information System (INIS)

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by (Nd:YAG) laser welding, which has been used successfully in Low Dose Rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8mm in diameter and 4.5mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources becomes a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a largest number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with Good Manufacturing Practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing Programmable Logic Controller (PLC), stepper motors, drivers, (Nd:YAG) laser welding machine, photoelectric sensors and supervisory. (author)

  7. Postoperative [{sup 125}I] seed brachytherapy in the treatment of acinic cell carcinoma of the parotid gland. With associated risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Ming-hui; Zhang, Jian-Guo; Zhang, Jie; Zheng, Lei; Liu, Shu-ming; Huang, Ming-wei; Shi, Yan [Peking Univ. School and Hospital of Stomatology, Beijing (China). Dept. of Oral and Maxillofacial Surgery

    2014-11-15

    This retrospective study was undertaken to analyze data from patients receiving iodine-125 ([{sup 125}I]) seed brachytherapy postoperatively for the treatment of acinic cell carcinoma (ACC) of the parotid gland along with the following risk factors: residual tumor, recurrent tumor, facial nerve invasion, positive resection margins, advanced tumor stage, or tumor spillage. Twenty-nine patients with ACC (17 females, 12 males; age range, 13-73 years; median age, 37.3 years) were included. Median follow-up was 58.2 months (range, 14-122 months). Patients received [{sup 125}I] seed brachytherapy (median actuarial D90, 177 Gy) 3-41 days (median, 14 days) following surgery. Radioactivity was 18.5-33.3 MBq per seed, and the prescription dose was 80-120 Gy. The 3-, 5-, and 10-year rates of local control were 93.1, 88.7, and 88.7 %, respectively; overall survival was 96.6, 92, and 92 %; disease-free survival was 93.1, 88.4, and 88.4 %; and freedom from distant metastasis was 96.6, 91.2, and 91.2 %. Lymph node metastases were absent in all patients, although two patients died with distant metastases. Facial nerve recovery was quick, and no severe radiotherapy-related complications were noted. Recurrence history, local recurrence, and distant metastasis significantly affected overall survival. Postoperative [{sup 125}I] seed brachytherapy is effective in treating ACC and has minor complications. Patients with a history of recurrence showed poor prognosis and were more likely to experience disease recurrence and develop metastases. (orig.) [German] Diese retrospektive Studie wurde durchgefuehrt, um die Daten von Patienten zu analysieren, die postoperativ eine Seed-Brachytherapie mit Iod-125 ([{sup 125}I]) zur Behandlung von Azinuszellkarzinomen der Ohrspeicheldruese mit begleitenden Risikofaktoren, wie Residualtumor, Rezidivtumor, Invasion in den N. facialis, positive (= nicht tumorfreie) Resektionsraender, fortgeschrittenes Tumorstadium oder lokale Verbreitung von Tumorzellen

  8. Prostate cancer brachytherapy

    International Nuclear Information System (INIS)

    The transperineal brachytherapy with 125I/Pd103 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

  9. Accuracy of applicator tip reconstruction in MRI-guided interstitial 192Ir-high-dose-rate brachytherapy of liver tumors

    International Nuclear Information System (INIS)

    Background and purpose: To evaluate the reconstruction accuracy of brachytherapy (BT) applicators tips in vitro and in vivo in MRI-guided 192Ir-high-dose-rate (HDR)-BT of inoperable liver tumors. Materials and methods: Reconstruction accuracy of plastic BT applicators, visualized by nitinol inserts, was assessed in MRI phantom measurements and in MRI 192Ir-HDR-BT treatment planning datasets of 45 patients employing CT co-registration and vector decomposition. Conspicuity, short-term dislocation, and reconstruction errors were assessed in the clinical data. The clinical effect of applicator reconstruction accuracy was determined in follow-up MRI data. Results: Applicator reconstruction accuracy was 1.6 ± 0.5 mm in the phantom measurements. In the clinical MRI datasets applicator conspicuity was rated good/optimal in ⩾72% of cases. 16/129 applicators showed not time dependent deviation in between MRI/CT acquisition (p > 0.1). Reconstruction accuracy was 5.5 ± 2.8 mm, and the average image co-registration error was 3.1 ± 0.9 mm. Vector decomposition revealed no preferred direction of reconstruction errors. In the follow-up data deviation of planned dose distribution and irradiation effect was 6.9 ± 3.3 mm matching the mean co-registration error (6.5 ± 2.5 mm; p > 0.1). Conclusion: Applicator reconstruction accuracy in vitro conforms to AAPM TG 56 standard. Nitinol-inserts are feasible for applicator visualization and yield good conspicuity in MRI treatment planning data. No preferred direction of reconstruction errors were found in vivo

  10. SU-E-J-215: Towards MR-Only Image Guided Identification of Calcifications and Brachytherapy Seeds: Application to Prostate and Breast LDR Implant Dosimetry

    International Nuclear Information System (INIS)

    Purpose: To identify and analyze the appearance of calcifications and brachytherapy seeds on magnitude and phase MRI images and to investigate whether they can be distinguished from each other on corrected phase images for application to prostate and breast low dose rate (LDR) implant dosimetry. Methods: An agar-based gel phantom containing two LDR brachytherapy seeds (Advantage Pd-103, IsoAid, 0.8mm diameter, 4.5mm length) and two spherical calcifications (large: 7mm diameter and small: 4mm diameter) was constructed and imaged on a 3T Philips MR scanner using a 16-channel head coil and a susceptibility weighted imaging (SWI) sequence (2mm slices, 320mm FOV, TR/ TE= 26.5/5.3ms, 15 degree flip angle). The phase images were unwrapped and corrected using a 32×32, 2D Hanning high pass filter to remove background phase noise. Appearance of the seeds and calcifications was assessed visually and quantitatively using Osirix (http://www.osirix-viewer.com/). Results: As expected, calcifications and brachytherapy seeds appeared dark (hypointense) relative to the surrounding gel on the magnitude MRI images. The diameter of each seed without the surrounding artifact was measured to be 0.1 cm on the magnitude image, while diameters of 0.79 and 0.37 cm were measured for the larger and smaller calcifications, respectively. On the corrected phase images, the brachytherapy seeds and the calcifications appeared bright (hyperintense). The diameter of the seeds was larger on the phase images (0.17 cm) likely due to the dipole effect. Conclusion: MRI has the best soft tissue contrast for accurate organ delineation leading to most accurate implant dosimetry. This work demonstrated that phase images can potentially be useful in identifying brachytherapy seeds and calcifications in the prostate and breast due to their bright appearance, which helps in their visualization and quantification for accurate dosimetry using MR-only. Future work includes optimizing phase filters to best identify

  11. SU-E-J-215: Towards MR-Only Image Guided Identification of Calcifications and Brachytherapy Seeds: Application to Prostate and Breast LDR Implant Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Elzibak, A; Fatemi-Ardekani, A; Soliman, A; Mashouf, S; Safigholi, H; Ravi, A; Morton, G; Song, WY [Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Han, D [Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To identify and analyze the appearance of calcifications and brachytherapy seeds on magnitude and phase MRI images and to investigate whether they can be distinguished from each other on corrected phase images for application to prostate and breast low dose rate (LDR) implant dosimetry. Methods: An agar-based gel phantom containing two LDR brachytherapy seeds (Advantage Pd-103, IsoAid, 0.8mm diameter, 4.5mm length) and two spherical calcifications (large: 7mm diameter and small: 4mm diameter) was constructed and imaged on a 3T Philips MR scanner using a 16-channel head coil and a susceptibility weighted imaging (SWI) sequence (2mm slices, 320mm FOV, TR/ TE= 26.5/5.3ms, 15 degree flip angle). The phase images were unwrapped and corrected using a 32×32, 2D Hanning high pass filter to remove background phase noise. Appearance of the seeds and calcifications was assessed visually and quantitatively using Osirix (http://www.osirix-viewer.com/). Results: As expected, calcifications and brachytherapy seeds appeared dark (hypointense) relative to the surrounding gel on the magnitude MRI images. The diameter of each seed without the surrounding artifact was measured to be 0.1 cm on the magnitude image, while diameters of 0.79 and 0.37 cm were measured for the larger and smaller calcifications, respectively. On the corrected phase images, the brachytherapy seeds and the calcifications appeared bright (hyperintense). The diameter of the seeds was larger on the phase images (0.17 cm) likely due to the dipole effect. Conclusion: MRI has the best soft tissue contrast for accurate organ delineation leading to most accurate implant dosimetry. This work demonstrated that phase images can potentially be useful in identifying brachytherapy seeds and calcifications in the prostate and breast due to their bright appearance, which helps in their visualization and quantification for accurate dosimetry using MR-only. Future work includes optimizing phase filters to best identify

  12. Iodine-125 seed brachytherapy for early stage prostate cancer: a single-institution review

    OpenAIRE

    Zuber, Simon; Weiß, Susan; Baaske, Dieter; Schöpe, Michael; Stevens, Simon; Bodis, Stephan; Zwahlen, Daniel R.

    2015-01-01

    Purpose We are reporting the five-year biochemical control, toxicity profile and dosimetric parameters using iodine-125 low dose rate brachytherapy (BT) as monotherapy for early stage prostate cancer at a single institution. Material and methods Between April 2006 and December 2010, 169 men with early stage prostate cancer were treated with BT. Biochemical failure was defined using the Phoenix definition (nadir + 2 ng/mL). Treatment-related morbidities, including urinary, rectal and sexual fu...

  13. Iodine-125 seed brachytherapy for early stage prostate cancer: a single-institution review

    OpenAIRE

    Zuber, Simon; Weiß, Susan; Baaske, Dieter; Schöpe, Michael; Stevens, Simon; Bodis, Stephan; Zwahlen, Daniel R.

    2015-01-01

    PURPOSE: We are reporting the five-year biochemical control, toxicity profile and dosimetric parameters using iodine-125 low dose rate brachytherapy (BT) as monotherapy for early stage prostate cancer at a single institution. MATERIAL AND METHODS: Between April 2006 and December 2010, 169 men with early stage prostate cancer were treated with BT. Biochemical failure was defined using the Phoenix definition (nadir + 2 ng/mL). Treatment-related morbidities, including urinary, rectal and sexu...

  14. WE-A-17A-09: Exploiting Electromagnetic Technologies for Real-Time Seed Drop Position Validation in Permanent Implant Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To report on preliminary results validating the performance of a specially designed LDR brachytherapy needle prototype possessing both electromagnetic (EM) tracking and seed drop detection abilities. Methods: An EM hollow needle prototype has been designed and constructed in collaboration with research partner Philips Healthcare. The needle possesses conventional 3D tracking capabilities, along with a novel seed drop detection mechanism exploiting local changes of electromagnetic properties generated by the passage of seeds in the needle's embedded sensor coils. These two capabilities are exploited by proprietary engineering and signal processing techniques to generate seed drop position estimates in real-time treatment delivery. The electromagnetic tracking system (EMTS) used for the experiment is the NDI Aurora Planar Field Generator. The experiment consisted of dropping a total of 35 seeds in a prismatic agarose phantom, and comparing the 3D seed drop positions of the EMTS to those obtained by an image analysis of subsequent micro-CT scans. Drop position error computations and statistical analysis were performed after a 3D registration of the two seed distributions. Results: Of the 35 seeds dropped in the phantom, 32 were properly detected by the needle prototype. Absolute drop position errors among the detected seeds ranged from 0.5 to 4.8 mm with mean and standard deviation values of 1.6 and 0.9 mm, respectively. Error measurements also include undesirable and uncontrollable effects such as seed motion upon deposition. The true accuracy performance of the needle prototype is therefore underestimated. Conclusion: This preliminary study demonstrates the potential benefits of EM technologies in detecting the passage of seeds in a hollow needle as a means of generating drop position estimates in real-time treatment delivery. Such tools could therefore represent a potentially interesting addition to existing brachytherapy protocols for rapid dosimetry

  15. WE-A-17A-09: Exploiting Electromagnetic Technologies for Real-Time Seed Drop Position Validation in Permanent Implant Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Racine, E [Departement de Radio-Oncologie et Centre de Recherche du CHU de Quebec, Quebec, QC (Canada); Hautvast, G [Biomedical Systems, Philips Group Innovation, Eindhoven, North Brabant (Netherlands); Binnekamp, D [Integrated Clinical Solutions and Marketing, Philips Healthcare, Best, DA (Netherlands); Beaulieu, L [Centre Hospitalier University de Quebec, Quebec, QC (Canada)

    2014-06-15

    Purpose: To report on preliminary results validating the performance of a specially designed LDR brachytherapy needle prototype possessing both electromagnetic (EM) tracking and seed drop detection abilities. Methods: An EM hollow needle prototype has been designed and constructed in collaboration with research partner Philips Healthcare. The needle possesses conventional 3D tracking capabilities, along with a novel seed drop detection mechanism exploiting local changes of electromagnetic properties generated by the passage of seeds in the needle's embedded sensor coils. These two capabilities are exploited by proprietary engineering and signal processing techniques to generate seed drop position estimates in real-time treatment delivery. The electromagnetic tracking system (EMTS) used for the experiment is the NDI Aurora Planar Field Generator. The experiment consisted of dropping a total of 35 seeds in a prismatic agarose phantom, and comparing the 3D seed drop positions of the EMTS to those obtained by an image analysis of subsequent micro-CT scans. Drop position error computations and statistical analysis were performed after a 3D registration of the two seed distributions. Results: Of the 35 seeds dropped in the phantom, 32 were properly detected by the needle prototype. Absolute drop position errors among the detected seeds ranged from 0.5 to 4.8 mm with mean and standard deviation values of 1.6 and 0.9 mm, respectively. Error measurements also include undesirable and uncontrollable effects such as seed motion upon deposition. The true accuracy performance of the needle prototype is therefore underestimated. Conclusion: This preliminary study demonstrates the potential benefits of EM technologies in detecting the passage of seeds in a hollow needle as a means of generating drop position estimates in real-time treatment delivery. Such tools could therefore represent a potentially interesting addition to existing brachytherapy protocols for rapid dosimetry

  16. Quality assurance of I-125 seeds for prostate brachytherapy using an imaging plate

    International Nuclear Information System (INIS)

    Purpose: OncoSeed is delivered in a sterile environment in the form of a cartridge, so it is impractical to resterilize and reload seeds after calibration. We investigated a new method using an imaging plate dosimetry system to characterize all seeds in the OncoSeed cartridge in a sterile environment. Methods and Materials: Seeds within the cartridge were placed on an imaging plate, and the imaging plate irradiated. To remove scatter radiation, and improve spatial resolution of seed images, we used X-ray parallel cross grids. The irradiated imaging plate was scanned using a Bio-imaging Analyzer System, and radioactivity intensities of seed images were given in counts. Counts could be translated to profiles, and each seed within the cartridge was analyzed. Results: Results showed a good correlation between counts and total radioactivity of the seeds within the cartridge. Thus, using a least-squares line, it was possible to characterize a cartridge with unknown apparent activity. By analyzing the profiles, it was possible not only to detect a miscalibrated seed in the cartridge from its relative difference in counts, but also to identify its position in the cartridge. No significant changes in counts were seen between sterile and nonsterile environments. Conclusion: Using an imaging plate dosimetry system, all seeds in a cartridge could be characterized in a sterile environment

  17. Tumor seeding to the neck through percutaneous applicators of intersitinal high-does-rate brachytherapy for cancer of the tongue. A case report

    International Nuclear Information System (INIS)

    We report the case of a 46-year-old woman with cancer of the tongue. She underwent interstitial high-dose-rate brachytherapy of 50 Gy in 10 fractions for 5 days following telecobalt therapy of 20 Gy in 10 fractions for 2 weeks. Seven applicators were percutaneously implanted into the tongue. Radical neck dissection was carried out because a tumor rapidly developed on the neck 2.5 months after the treatment. Pathological examination revealed tumor seeding to the soft tissue of the neck where applicators were placed. To the best of our knowledge, there have been no reports presenting tumor seeding through percutaneous applicators of interstitial brachytherapy for head and neck tumor. (author)

  18. Characterization of ceramic seeds with samarium-153 for use in brachytherapy

    OpenAIRE

    Eduardo Sarmento Valente; Ethel Mizrahy Cuperschmid; Tarcísio Passos Ribeiro de Campos

    2011-01-01

    Ceramic seeds were synthesized by the sol-gel technique with Si:Sm:Ca. One sample was irradiated in the TRIGA nuclear reactor IPR-R1. After irradiation, the seeds were submitted to instrumental neutron activation analysis to determine the 153Sm concentration in weight. The same irradiated seed sample was submitted to gamma spectrometry analysis to determine all existing radionuclides as well as its individual activities. A second sample was submitted to ICP-AES atomic emission spectrometry. A...

  19. Layered mass geometry: a novel technique to overlay seeds and applicators onto patient geometry in Geant4 brachytherapy simulations

    International Nuclear Information System (INIS)

    A problem faced by all Monte Carlo (MC) particle transport codes is how to handle overlapping geometries. The Geant4 MC toolkit allows the user to create parallel geometries within a single application. In Geant4 the standard mass-containing geometry is defined in a simulation volume called the World Volume. Separate parallel geometries can be defined in parallel worlds, that is, alternate three dimensional simulation volumes that share the same coordinate system with the World Volume for geometrical event biasing, scoring of radiation interactions, and/or the creation of hits in detailed readout structures. Until recently, only one of those worlds could contain mass so these parallel worlds provided no solution to simplify a complex geometric overlay issue in brachytherapy, namely the overlap of radiation sources and applicators with a CT based patient geometry. The standard method to handle seed and applicator overlay in MC requires removing CT voxels whose boundaries would intersect sources, placing the sources into the resulting void and then backfilling the remaining space of the void with a relevant material. The backfilling process may degrade the accuracy of patient representation, and the geometrical complexity of the technique precludes using fast and memory-efficient coding techniques that have been developed for regular voxel geometries. The patient must be represented by the less memory and CPU-efficient Geant4 voxel placement technique, G4PVPlacement, rather than the more efficient G4NestedParameterization (G4NestedParam). We introduce for the first time a Geant4 feature developed to solve this issue: Layered Mass Geometry (LMG) whereby both the standard (CT based patient geometry) and the parallel world (seeds and applicators) may now have mass. For any area where mass is present in the parallel world, the parallel mass is used. Elsewhere, the mass of the standard world is used. With LMG the user no longer needs to remove patient CT voxels that would

  20. Comparison of Intraoperatively Built Custom Linked Seeds Versus Loose Seed Gun Applicator Technique Using Real-Time Intraoperative Planning for Permanent Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To report our dosimetric results using a novel push-button seed delivery system that constructs custom links of seeds intraoperatively. Methods and Materials: From 2005 to 2007, 43 patients underwent implantation using a gun applicator (GA), and from 2007 to 2008, 48 patientsunderwent implantation with a novel technique allowing creation of intraoperatively built custom links of seeds (IBCL). Specific endpoint analyses were prostate D90% (pD90%), rV100% > 1.3 cc, and overall time under anesthesia. Results: Final analyses included 91 patients, 43 GA and 48 IBCL. Absolute change in pD90% (ΔpD90%) between intraoperative and postoperative plans was evaluated. Using GA method, the ΔpD90% was −8.1Gy and −12.8Gy for I-125 and Pd-103 implants, respectively. Similarly, the IBCL technique resulted in a ΔpD90% of −8.7Gy and −9.8Gy for I-125 and Pd-103 implants, respectively. No statistically significant difference in ΔpD90% was found comparing methods. The GA method had two intraoperative and 10 postoperative rV100% >1.3 cc. For IBCL, five intraoperative and eight postoperative plans had rV100% >1.3 cc. For GA, the mean time under anesthesia was 75 min and 87 min for Pd-103 and I-125 implants, respectively. For IBCL, the mean time was 86 and 98 min for Pd-103 and I-125. There was a statistical difference between the methods when comparing mean time under anesthesia. Conclusions: Dosimetrically relevant endpoints were equivalent between the two methods. Currently, time under anesthesia is longer using the IBCL technique but has decreased over time. IBCL is a straightforward brachytherapy technique that can be implemented into clinical practice as an alternative to gun applicators.

  1. The seven-year preliminary results of brachytherapy with Iodine-125 seeds for localized prostate cancer treated at a Brazilian single-center

    Directory of Open Access Journals (Sweden)

    Carlos A. S. Franca

    2007-12-01

    Full Text Available OBJECTIVE: To report the seven-year preliminary results of a single-center on brachytherapy with Iodine-125 seeds, used in combination with external beam radiotherapy in selected patients with localized prostate cancer (T1-T2. MATERIALS AND METHODS: All 105 patients treated by brachytherapy with Iodine-125 seeds, from January/1998 to December/2004, were retrospectively analyzed. The prescribed dose was 144 Gy at the periphery of the prostate for isolated brachytherapy, and 110 Gy for the combination with external beam radiotherapy. The external beam radiotherapy dose was 45 Gy, at the prostatic bed. Neoadjuvant hormone therapy was indicated for selected patients, who received luteinizing hormone-releasing hormone (LH-RH and/or antiandrogens. For definition of biochemical relapse, it was adopted the American Society for Therapeutic Radiology and Oncology consensus. RESULTS: Of the 105 patients treated, 90 were followed for a mean period of 70 months. Biochemical disease control was achieved in 62 (69% and biochemical recurrence was manifested in 28 (31%. The analysis of each risk group showed biochemical disease control rates of 79%, 71% and 52% in the low, intermediate and high risk groups, respectively. The mean time for biochemical recurrence was 22 months. Genitourinary acute toxicity was classified as grade 0-2 (RTOG in 88.5% and in 94.2% for the late toxicity (RTOG/EORTC. Gastrointestinal acute toxicity was graded as 0-2 (RTOG in 100% and in 97.7% for the late morbidity. No grade 5 was detected. CONCLUSIONS: Brachytherapy with Iodine-125 seeds is an effective alternative treatment for early stage prostatic cancer, with good biochemical disease control rates and low to moderate toxicity. The best results were obtained in low and intermediate risk patients.

  2. BrachyView: multiple seed position reconstruction and comparison with CT post-implant dosimetry

    Science.gov (United States)

    Alnaghy, S.; Loo, K. J.; Cutajar, D. L.; Jalayer, M.; Tenconi, C.; Favoino, M.; Rietti, R.; Tartaglia, M.; Carriero, F.; Safavi-Naeini, M.; Bucci, J.; Jakubek, J.; Pospisil, S.; Zaider, M.; Lerch, M. L. F.; Rosenfeld, A. B.; Petasecca, M.

    2016-05-01

    BrachyView is a novel in-body imaging system utilising high-resolution pixelated silicon detectors (Timepix) and a pinhole collimator for brachytherapy source localisation. Recent studies have investigated various options for real-time intraoperative dynamic dose treatment planning to increase the quality of implants. In a previous proof-of-concept study, the justification of the pinhole concept was shown, allowing for the next step whereby multiple active seeds are implanted into a PMMA phantom to simulate a more realistic clinical scenario. In this study, 20 seeds were implanted and imaged using a lead pinhole of 400 μ m diameter. BrachyView was able to resolve the seed positions within 1–2 mm of expected positions, which was verified by co-registering with a full clinical post-implant CT scan.

  3. Physical and technical quality assurance and radiation protection in transperineal interstitial permanent prostate brachytherapy with 125-iodine seeds

    International Nuclear Information System (INIS)

    Background: Early stage prostate cancer can be treated successfully by intersitial brachytherapy with 125-iodine seeds. A quality-assurance programme is presented that was designed for this purpose for internal clinical use. Furthermore the requirements of the new German Ordinance Governing Radiation Protection (StrlSchV) that came into force on August 1, 2001, are taken into account. Material and Methods: For the 125-iodine monotherapy of the prostate we used RAPID STRANDS trademark (Amersham Health, Braunschweig, Germany). According to the guidelines of the new Ordinance Governing Radiation Protection, the determination of the body dose of the staff is made to rely on the new measurement quantities Hp(10) and Hp(0.07). The nominal air kerma rate of the seeds is measured with a calibrated well-chamber of the type HDR 1000 Plus and an electrometer of the type MAX 4000 (Standard Imaging Inc., USA). The ultrasound images of the prostate are produced by an ultrasound device of the type Falcon 2101 (B-K Medical, Denmark). For treatment planning the programme VariSeed (Varian, Darmstadt, Germany) was employed. Correct loading of the needles is controlled by autoradiography before implantation. After the implantation radiation-protection measurements in the operating room are carried out. Results: As regards the personnel, for the depth personal dose equivalent Hp(10) and relating to two applications each, measurement values between 0 μSv and 14 μSv resulted. The control of the radiation exposure of the hands revealed superficial personal dose values Hp(0.07) of up to 1 mSv. The nominal air kerma rates of the RAPID STRANDS trademark were all lying within the 95% confidence interval guaranteed by the producer. The autoradiographys documented - except for one case - the correct loading of the needles. The interstitial transperineal prostate implantation of the 125-iodine seeds succeeded as planned with all patients. Until now no contamination of the operating room was

  4. Preliminary Study on Palladium-103 Production By Neutron Activation Using G.A. Siwabessy Reactor For Brachytherapy Seed

    International Nuclear Information System (INIS)

    Palladium-103 (Pd-103) is one of the effective radionuclides for brachytherapy seed. Preliminary study on Palladium-103 production by calculations of Palladium irradiation in G.A. Siwabessy reactor has been carried out. The calculation was performed using natural and enriched Palladium metal with a length of 45 mm and a diameter of 0.8 mm at central irradiation position (neutron flux 1,3xl014 n.s-l.cm-2) and rabbit system (neutron flux 4xl013 n.s-1.cm-2). Calculation results showed that irradiation of natural Palladium at rabbit system for 12 hours resulted in Palladium-103 with radioactivity of 4.27 MBq at the end of irradiation (EOI), lower than the minimum radioactivity for seed (37 MBq). Irradiation of enriched Palladium (Pd-102 enrichment 89%) at rabbit system resulted in Pd-103 with radioactivity of 387 MBq at EOI. Radionuclide impurities of Pd-109 and Pd-111 were produced in the irradiation process. Radioactivity of Pd-111 decreased rapidly since the half life is very short (23.3 min). Radionuclide impurity of Pd-109 decreased to less that 0.1% of Pd-103 radioactivity after 6.3 days. The radioactivity of Pd-103 became 299 MBq 6.3 days after irradiation. Irradiation of natural Palladium at central irradiation position resulted in Pd-103 with radioactivity of 265 MBq at EOI. Radioactivity of Pd-109 was 4390 MBq at EOI and decreased to less than 0.1% of Pd-103 radioactivity after 8,3 days. The radioactivity of Pd-103 decreased to 189 MBq after the decay time. (author)

  5. Assessment of I-125 seed implant accuracy when using the live-planning technique for low dose rate prostate brachytherapy

    International Nuclear Information System (INIS)

    Low risk prostate cancers are commonly treated with low dose rate (LDR) brachytherapy involving I-125 seeds. The implementation of a ‘live-planning’ technique at the Royal Adelaide Hospital (RAH) in 2007 enabled the completion of the whole procedure (i.e. scanning, planning and implant) in one sitting. ‘Live-planning’ has the advantage of a more reliable delivery of the planned treatment compared to the ‘traditional pre-plan’ technique (where patient is scanned and planned in the weeks prior to implant). During live planning, the actual implanted needle positions are updated real-time on the treatment planning system and the dosimetry is automatically recalculated. The aim of this investigation was to assess the differences and clinical relevance between the planned dosimetry and the updated real-time implant dosimetry. A number of 162 patients were included in this dosimetric study. A paired t-test was performed on the D90, V100, V150 and V200 target parameters and the differences between the planned and implanted dose distributions were analysed. Similarly, dosimetric differences for the organs at risk (OAR) were also evaluated. Small differences between the primary dosimetric parameters for the target were found. Still, the incidence of hotspots was increased with approximately 20% for V200. Statistically significant increases were observed in the doses delivered to the OAR between the planned and implanted data; however, these increases were consistently below 3% thus probably without clinical consequences. The current study assessed the accuracy of prostate implants with I-125 seeds when compared to initial plans. The results confirmed the precision of the implant technique which RAH has in place. Nevertheless, geographical misses, anatomical restrictions and needle displacements during implant can have repercussions for centres without live-planning option if dosimetric changes are not taken into consideration

  6. Preimplant factors affecting postimplant CT-determined prostate volume and the CT/TRUS volume ratio after transperineal interstitial prostate brachytherapy with 125I free seeds

    International Nuclear Information System (INIS)

    The aim was to identify preimplant factors affecting postimplant prostate volume and the increase in prostate volume after transperineal interstitial prostate brachytherapy with 125I free seeds. We reviewed the records of 180 patients who underwent prostate brachytherapy with 125I free seeds for clinical T1/T2 prostate cancer. Eighty-one (45%) of the 180 patients underwent neoadjuvant hormonal therapy. No patient received supplemental external beam radiotherapy. Postimplant computed tomography was undertaken, and postimplant dosimetric analysis was performed. Univariate and multivariate analyses were performed to identify preimplant factors affecting postimplant prostate volume by computed tomography and the increase in prostate volume after implantation. Preimplant prostate volume by transrectal ultrasound, serum prostate-specific antigen, number of needles, and number of seeds implanted were significantly correlated with postimplant prostate volume by computed tomography. The increase in prostate volume after implantation was significantly higher in patients with neoadjuvant hormonal therapy than in those without. Preimplant prostate volume by transrectal ultrasound, number of needles, and number of seeds implanted were significantly correlated with the increase in prostate volume after implantation. Stepwise multiple linear regression analysis showed that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy were significant independent factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation. The results of the present study show that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy are significant preimplant factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation

  7. Anisotropy characterization of I-125 seed with attached encapsulated cobalt chloride complex contrast agent markers for MRI-based prostate brachytherapy.

    Science.gov (United States)

    Frank, Steven J; Tailor, Ramesh C; Kudchadker, Rajat J; Martirosyan, Karen S; Stafford, R Jason; Elliott, Andrew M; Swanson, David A; Sing, David; Choi, Jonathan; Mourtada, Firas; Ibbott, Geoffrey S

    2011-01-01

    We have developed a novel MRI marker for prostate brachytherapy. The purpose of this study was to evaluate the changes in anisotropy when cobalt chloride complex contrast agent encapsulated contrast agent markers (C4-ECAM) were placed adjacent to an iodine-125 (I-125) titanium seed, and to verify that the C4-ECAMs were visible on magnetic resonance imaging (MRI) after radiation exposure. Two C4-ECAMs were verified to be MRI visible in a phantom before radiation exposure. The C4-ECAMs were then attached to each end of a 12.7-U (10-mCi) I-125 titanium seed in a polymer tube. Anisotropy was measured and analyzed with the seed alone and with attached C4-ECAMs by suspending thermoluminescent dosimeters in a water phantom in 2 circles surrounding the radioactive source with radius of 1 or 2 cm. A T1-weighted MRI evaluation of C4-ECAMs was then performed after exposure to the amount of radiation typically delivered during 1 month of prostate brachytherapy. Measured values of the anisotropy function F(r, θ) for the I-125 seed with and without the C4-ECAMs were mutually statistically indistinguishable (standard error of the mean <4.2%) and agreed well with published TG-43 values for the bare seed. As expected, the anisotropy function ϕ(an)(r) for the 2 datasets (with and without C4-ECAMs) derived from the measured F(r, θ) did not exhibit statistically measurable difference. Both datasets showed agreement with the published TG-43 ϕ(an)(r) for the bare seed. The C4-ECAMs were well visualized by MRI after 1 month of radiation exposure. There were no changes in anisotropy when the C4-ECAMs were placed next to an I-125 radioactive seed, and the C4-ECAMs were visualized after radiation exposure. PMID:20537886

  8. An analysis of brachytherapy with computed tomography-guided permanent implantation of Iodine-125 seeds for recurrent nonkeratin nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Shen X

    2015-05-01

    Full Text Available Xinying Shen,1,2 Yong Li,2 Yanfang Zhang,2 Jian Kong,2 Yanhao Li1 1Department of Interventional Radiology, Nanfang Hospital, Southern Medical University, Guangzhou, 2Department of Interventional Radiology, Shenzhen People’s Hospital, The Second Clinical Medical College of Jinan University, Shenzhen, People’s Republic of China Background: 125I seed implantation is a new method in treatment of nasopharyngeal carcinoma (NPC, and it is worthwhile to evaluate its feasibility. In this study, we performed brachytherapy with computed tomography (CT-guided permanent implantation of 125I seeds in the treatment of patients with the recurrence of NPC.Methods: A total 30 patients (20 male and ten female at the median age of 55 (range 25–80 years were diagnosed with recurrent nonkeratin NPC, with a total 38 lesions and a short disease-free interval (median ~11 months after primary radiotherapy alone or combined with chemotherapy. Patients received CT scan, starting from 2 months after the treatment. Follow-up was conducted for ~2–38 months to observe the local control rate and overall survival rate. We also analyzed the possible correlation between survival periods and the status of recurrent tumors.Results: The local control rates at 6, 12, 24, 30, and 36 months after the procedure of 125I seed implantation were 86.8%, 73.7%, 26.3%, 15.8%, and 5.3%, respectively. The overall 1-, 2-, and 3-year survival rates were 80.0% (24/30, 30.0% (9/30, and 6.7% (2/30, respectively, with a median survival period of 18 months (17.6±8.6 months. Interestingly, the survival periods of the patients who had primary radiotherapy with or without chemotherapy were 15.8±7.9 and 24.3±7.9 months, respectively. Kaplan–Meier survival analysis demonstrated that χ2 (log rank was 7.555, with very significant difference (P<0.01. The survival periods of patients in tumor stages I, II, III, and IV were 25.4±8.7, 19.8±9.4, 16.1±4.5, and 12.8±7.8 months, respectively, with

  9. Anisotropy Characterization of I-125 Seed with Attached Encapsulated Cobalt Chloride Complex Contrast Agent Markers for MRI-Based Prostate Brachytherapy

    International Nuclear Information System (INIS)

    We have developed a novel MRI marker for prostate brachytherapy. The purpose of this study was to evaluate the changes in anisotropy when cobalt chloride complex contrast agent encapsulated contrast agent markers (C4-ECAM) were placed adjacent to an iodine-125 (I-125) titanium seed, and to verify that the C4-ECAMs were visible on magnetic resonance imaging (MRI) after radiation exposure. Two C4-ECAMs were verified to be MRI visible in a phantom before radiation exposure. The C4-ECAMs were then attached to each end of a 12.7-U (10-mCi) I-125 titanium seed in a polymer tube. Anisotropy was measured and analyzed with the seed alone and with attached C4-ECAMs by suspending thermoluminescent dosimeters in a water phantom in 2 circles surrounding the radioactive source with radius of 1 or 2 cm. A T1-weighted MRI evaluation of C4-ECAMs was then performed after exposure to the amount of radiation typically delivered during 1 month of prostate brachytherapy. Measured values of the anisotropy function F(r, θ) for the I-125 seed with and without the C4-ECAMs were mutually statistically indistinguishable (standard error of the mean an(r) for the 2 datasets (with and without C4-ECAMs) derived from the measured F(r, θ) did not exhibit statistically measurable difference. Both datasets showed agreement with the published TG-43 φan(r) for the bare seed. The C4-ECAMs were well visualized by MRI after 1 month of radiation exposure. There were no changes in anisotropy when the C4-ECAMs were placed next to an I-125 radioactive seed, and the C4-ECAMs were visualized after radiation exposure.

  10. Poster — Thur Eve — 42: Radiochromic film calibration for low-energy seed brachytherapy dose measurement

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the accuracy of radiochromic film calibration procedures used in external beam radiotherapy when applied to I-125 brachytherapy sources delivering higher doses, and to determine any necessary modifications to achieve similar accuracy in absolute dose measurements. GafChromic EBT3 film was used to measure radiation doses upwards of 35 Gy from 6 MV, 75 kVp and (∼28 keV) I-125 photon sources. A custom phantom was used for the I-125 irradiations to obtain a larger film area with nearly constant dose to reduce the effects of film heterogeneities on the optical density (OD) measurements. RGB transmission images were obtained with an Epson 10000XL flatbed scanner, and calibration curves relating OD and dose using a rational function were determined for each colour channel and at each energy using a non-linear least square minimization method. Differences found between the 6 MV calibration curve and those for the lower energy sources are large enough that 6 MV beams should not be used to calibrate film for low-energy sources. However, differences between the 75 kVp and I-125 calibration curves were quite small; indicating that 75 kVp is a good choice. Compared with I-125 irradiation, this gives the advantages of lower type B uncertainties and markedly reduced irradiation time. To obtain high accuracy calibration for the dose range up to 35 Gy, two-segment piece-wise fitting was required. This yielded absolute dose measurement accuracy above 1 Gy of ∼2% for 75 kVp and ∼5% for I-125 seed exposures

  11. 3D Surface Reconstruction of Plant Seeds by Volume Carving: Performance and Accuracies

    Science.gov (United States)

    Roussel, Johanna; Geiger, Felix; Fischbach, Andreas; Jahnke, Siegfried; Scharr, Hanno

    2016-01-01

    We describe a method for 3D reconstruction of plant seed surfaces, focusing on small seeds with diameters as small as 200 μm. The method considers robotized systems allowing single seed handling in order to rotate a single seed in front of a camera. Even though such systems feature high position repeatability, at sub-millimeter object scales, camera pose variations have to be compensated. We do this by robustly estimating the tool center point from each acquired image. 3D reconstruction can then be performed by a simple shape-from-silhouette approach. In experiments we investigate runtimes, theoretically achievable accuracy, experimentally achieved accuracy, and show as a proof of principle that the proposed method is well sufficient for 3D seed phenotyping purposes. PMID:27375628

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

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M., E-mail: manuel.rodriguez@rmp.uhn.ca [Carleton Laboratory for Radiotherapy Physics, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Rogers, D. W. O. [Carleton Laboratory for Radiotherapy Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada)

    2014-11-01

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

  13. Twelve-Month Prostate-Specific Antigen Values and Perineural Invasion as Strong Independent Prognostic Variables of Long-Term Biochemical Outcome After Prostate Seed Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To determine whether post-treatment prostate-specific antigen (ptPSA) values at 12 months and other clinical parameters predict long-term PSA relapse-free survival (PRFS) following prostate seed brachytherapy. Methods and Materials: Records of 204 hormone-naïve patients with localized adenocarcinoma of the prostate treated at St. Mary’s Regional Medical Center in Reno, NV, and at Carson Tahoe Regional Medical Center in Carson City, NV, between 1998 and 2003, using I-125 or Pd-103 seed brachytherapy, were retrospectively analyzed. Treatment planning was done using a preplanned, modified peripheral loading technique. A total of 185 of 204 patients had PSA records at 12 months after implant. Variables included were age, initial pretreatment PSA, Gleason score, T stage, National Comprehensive Cancer Network (NCCN) risk group (RG), perineural invasion (PNI), external beam boost, dose, and ptPSA levels at 12 months with cutpoints at ≤1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml. Results: Median follow-up was 80 months, and median age was 69 years. The numbers of patients stratified by NCCN low, intermediate, and high RG were 110:65:10, respectively. Monotherapy and boost prescription doses were 145 Gy and 110 Gy for I-125, and 125 Gy and 100 Gy for Pd-103 seeds, respectively. The median dose (D90) was 95.4% of the prescribed dose. The 5-year PRFS at the 12-months ptPSA levels of ≤1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml were 98.5%, 85.7%, 61.5%, and 22.2%, respectively. The 10-year PRFS at the 12-months ptPSA levels of ≤1 and 1.01 to 2.00 ng/ml were 90.5% and 85.7%, respectively. In multivariate analysis, both ptPSA and PNI were significant independent predictors of PRFS. Hazard ratios (HR) for ptPSA levels at ≤1, 1.01 to 2.00, 2.01 to 3.00, and >3.00 ng/ml at 12 months were 1, 4.96, 27.57, and 65.10, respectively. PNI had an HR of 6.1 (p = 0.009). Conclusions: Presence of PNI and ptPSA values at 12 months are strong prognostic variables for

  14. Prostate volume changes during permanent seed brachytherapy: an analysis of intra-operative variations, predictive factors and clinical implication

    International Nuclear Information System (INIS)

    To determine prostate volume (Pvol) changes at 3 different time points during the course of I125 permanent seed brachytherapy (PB). To assess the impact of these changes on acute urinary retention (AUR) and dosimetric outcome. We analyzed 149 hormone-naïve patients. Measurements of the prostate volume were done using three-dimensional transrectal ultrasound (3D-TRUS) in the operating room before insertion of any needle (V1), after the insertion of 2 fixation needles with a harpoon (V2) and upon completion of the implant (V3). The quality of the implant was analyzed with the D90 (minimum dose in Grays received by 90% of the prostate volume) at day 30. Mean baseline prostate volume (V1) was 37.4 ± 9.6 cc. A volume increase of >5% was seen in 51% between V1-V2 (mean = 2.5 cc, p < 0.01), in 42% between V2-V3 (mean = 1.9 cc, p < 0.01) and in 71% between V1-V3 (mean = 4.5 cc, p < 0.01). Pvol changes caused by insertion of the fixation needles were not statistically different than those caused by the implant itself (p = 0.23). In multivariate linear regression analysis, baseline Pvol is predictive of Pvol changes between V2 and V1 and V3 and V1 but not between V3 and V2. The extent of prostate swelling had an influence on D90. An increase of 10% in prostate volume between V1 and V2 results in an increase of D90 at Day 30 by 11.7%. Baseline Pvol (V1) was the only predictor of the duration of urinary retention in both univariate and multivariate (p = 0.04) regression analysis. A large part of intraoperative swelling occurs already after the insertion of the fixation needles. This early prostate swelling predicts for D90 but not for AUR

  15. Monte Carlo investigation of I-125 interseed attenuation for standard and thinner seeds in prostate brachytherapy with phantom validation using a MOSFET

    Energy Technology Data Exchange (ETDEWEB)

    Mason, J.; Al-Qaisieh, B.; Bownes, P. [Department of Medical Physics and Engineering, St. James' s Institute of Oncology, St. James' s University Hospital, Leeds, LS9 7TF (United Kingdom); Henry, A. [Clinical Oncology, St. James' s Institute of Oncology, St. James' s University Hospital, Leeds, LS9 7TF (United Kingdom); Thwaites, D. [Institute of Medical Physics, School of Physics, University of Sydney, NSW 2006, Australia and Academic Unit of Medical Physics, University of Leeds, LS2 9JT (United Kingdom)

    2013-03-15

    Purpose: In permanent seed implant prostate brachytherapy the actual dose delivered to the patient may be less than that calculated by TG-43U1 due to interseed attenuation (ISA) and differences between prostate tissue composition and water. In this study the magnitude of the ISA effect is assessed in a phantom and in clinical prostate postimplant cases. Results are compared for seed models 6711 and 9011 with 0.8 and 0.5 mm diameters, respectively. Methods: A polymethyl methacrylate (PMMA) phantom was designed to perform ISA measurements in a simple eight-seed arrangement and at the center of an implant of 36 seeds. Monte Carlo (MC) simulation and experimental measurements using a MOSFET dosimeter were used to measure dose rate and the ISA effect. MC simulations of 15 CT-based postimplant prostate treatment plans were performed to compare the clinical impact of ISA on dose to prostate, urethra, rectum, and the volume enclosed by the 100% isodose, for 6711 and 9011 seed models. Results: In the phantom, ISA reduced the dose rate at the MOSFET position by 8.6%-18.3% (6711) and 7.8%-16.7% (9011) depending on the measurement configuration. MOSFET measured dose rates agreed with MC simulation predictions within the MOSFET measurement uncertainty, which ranged from 5.5% to 7.2% depending on the measurement configuration (k= 1, for the mean of four measurements). For 15 clinical implants, the mean ISA effect for 6711 was to reduce prostate D90 by 4.2 Gy (3%), prostate V100 by 0.5 cc (1.4%), urethra D10 by 11.3 Gy (4.4%), rectal D2cc by 5.5 Gy (4.6%), and the 100% isodose volume by 2.3 cc. For the 9011 seed the mean ISA effect reduced prostate D90 by 2.2 Gy (1.6%), prostate V100 by 0.3 cc (0.7%), urethra D10 by 8.0 Gy (3.2%), rectal D2cc by 3.1 Gy (2.7%), and the 100% isodose volume by 1.2 cc. Differences between the MC simulation and TG-43U1 consensus data for the 6711 seed model had a similar impact, reducing mean prostate D90 by 6 Gy (4.2%) and V100 by 0.6 cc (1

  16. Brachytherapy with Iodine-125 seeds strand for treatment of main portal vein tumor thrombi: an experimental study in a rabbit model

    Science.gov (United States)

    Zhang, Wen; Luo, Jianjun; Liu, Qingxin; Ma, Jingqin; Qu, Xudong; Yang, Minjie; Yan, Zhiping; Wang, Jianhua

    2016-01-01

    This study aims to establish an animal model of implanted main portal vein tumor thrombus (MPVTT) and to evaluate safety and efficacy of brachy therapy with Iodine-125 (125I) seeds strand to treat MPVTT of rabbit. VX2 tumor thrombus was implanted in main portal vein (MPV) of 32 New Zealand white rabbits. These rabbits were randomly divided into treatment group (Group T, T1-T16) and control group (Group C, C1-C16). 125I seeds and blank seeds strand were implanted in MPV of rabbits in Group T and C, respectively. Changes of general condition, body weight and blood laboratory examination were monitored at every time point after procedure. 2 weeks later, 8 rabbits of each group were sacrificed for pathologic examination. The rest of rabbits were dissected postmortem, and therapeutic effects were evaluated on basis of multi-detector computed tomography and histopathology. Ki-67 labeling index (Ki-67 LI) and apoptosis index (AI) were compared between two groups. Overall survival period was recorded. At every time point after brachytherapy, more serious weight loss were detected in Group C. Results of liver function tests and blood cells counts showed no significant difference between two groups. Mean volume of tumor tissue within MPV were 565.40 ± 220.90 mm3 in Group T and 2269.90 ± 437.00 mm3 in Group C (P < 0.001). (Ki-67 LI) and AI were (4.14 ± 1.84)% and (6.51 ± 1.92)% in Group T, compared with (33.82 ± 6.07)% and (0.91 ± 0.26)% in Group C, respectively (P < 0.001). Media survival time of rabbits were 39.50 ± 2.37 days in Group T and 27.38 ± 1.22 days in Group C, respectively (P = 0.001). In conclusion, injecting and suspensory fixing VX2 tumor strip into MPV is a reliable method to establish MPVTT animal model. Brachytherapy with 125I seeds strand was safe and effective to treat VX2 tumor strand inoculated in the MPV of rabbit. PMID:27152237

  17. WE-A-17A-10: Fast, Automatic and Accurate Catheter Reconstruction in HDR Brachytherapy Using An Electromagnetic 3D Tracking System

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, E; Racine, E; Beaulieu, L [CHU de Quebec - Universite Laval, Quebec, Quebec (Canada); Binnekamp, D [Integrated Clinical Solutions and Marketing, Philips Healthcare, Best, DA (Netherlands)

    2014-06-15

    Purpose: In high dose rate brachytherapy (HDR-B), actual catheter reconstruction protocols are slow and errors prompt. The purpose of this study was to evaluate the accuracy and robustness of an electromagnetic (EM) tracking system for improved catheter reconstruction in HDR-B protocols. Methods: For this proof-of-principle, a total of 10 catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a Philips-design 18G biopsy needle (used as an EM stylet) and the second generation Aurora Planar Field Generator from Northern Digital Inc. The Aurora EM system exploits alternating current technology and generates 3D points at 40 Hz. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical CT system with a resolution of 0.089 mm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, 5 catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 seconds or less. This would imply that for a typical clinical implant of 17 catheters, the total reconstruction time would be less than 3 minutes. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.92 ± 0.37 mm and 1.74 ± 1.39 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be significantly more accurate (unpaired t-test, p < 0.05). A mean difference of less than 0.5 mm was found between successive EM reconstructions. Conclusion: The EM reconstruction was found to be faster, more accurate and more robust than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators. We would like to disclose that the equipments, used in this study, is coming from a collaboration with Philips Medical.

  18. The effectiveness of 125I seed interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice: an experiment in vivo

    International Nuclear Information System (INIS)

    Objective: To discuss the effectiveness and therapeutic mechanism of 125I interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice. Methods: The human pancreatic cell line Sw1990 was subcutaneously injected into the right lower limb partially dorsal area next to the groin of the immunodeficient BABL /c nude mice. The tumor was removed and cut into small pieces after it was formed,then the tumor pieces were inoculated in nude mice. The tumor developed to 8-10 mm in size after six weeks. A total of 16 nude mice with the suitable tumor size were used in this study. The 16 experimental mice were randomly and equally divided into two groups. The mice in study group (n = 8) were implanted with 125I seeds, while the mice in control group (n = 8) were implanted with ghost seeds. After the implantation both the long and short diameter of the tumors as well as the mouse body weight were measured every 4 days. The tumor weight was measured when the mouse was sacrificed. The paraffin-embedded samples were sent for histopathological examination. Apoptotic cells were checked with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Expression of proliferating cell nuclear antigen (PCNA) was detected with immuno-histochemical staining. Results: The tumor grew slowly in the study group, but rapidly in the control group. The tumor weight in the study group and the control group was (2.68 ± 0.70)g and (4.68 ± 1.45)g, respectively, the difference between two groups was statistically significant (P = 0.021). The tumor inhibition rate was about 42.66%. No significant difference in body weight of nude mice existed between two groups both before and after the treatment (P > 0.05). Marked tumor necrosis was seen in study group, but no obvious, or only a little, tumor necrosis could be observed in the control group. The apoptotic index checked with the TUENL method in the study group and control group was (23.2 ± 1.9)% and

  19. High-contrast pattern reconstructions using a phase-seeded point CGH method.

    Science.gov (United States)

    McWilliam, Richard; Williams, Gavin L; Cowling, Joshua J; Seed, Nicholas L; Purvis, Alan

    2016-03-01

    A major challenge encountered in digital holography applications is the need to synthesize computer-generated holograms (CGHs) that are realizable as phase-only elements while also delivering high quality reconstruction. This trade-off is particularly acute in high-precision applications such as photolithography where contrast typically must exceed 0.6. A seeded-phase point method is proposed to address this challenge, whereby patterns composed of fine lines that intersect and form closed shapes are reconstructed with high contrast while maintaining a phase-only CGH. The method achieves superior contrast to that obtained by uniform or random seeded-phase methods while maintaining computational efficiency for large area exposures. It is also shown that binary phase modulation achieves similar contrast performance with benefits for the fabrication of simpler diffractive optical elements. PMID:26974633

  20. About TLD-100 glow curve manipulation to achieve dosimetric parameters of I-125 seeds used for brachytherapy

    International Nuclear Information System (INIS)

    Brachytherapy with 125I sources is applied, mainly, to the treatment of prostate, cerebral and ophthalmologic cancers. For experimental measurements, thermoluminescence dosimeters (like TLD-100) are widely used for brachytherapy dosimetry requests. The TLD-100 is a LiF:Mg,Ti crystal and its thermoluminescence response, the glow curve, has some peaks registered during the reading. In order to establish the direct relationship between dose and TL response, the total or partial integration of the glow curve could be used, or simply the size of a peak. If not using the size of this peak, the integration of a temperature interval containing it, is normally used. The aim of this work is to analyze the influence on dosimetric properties whether the main peak is selected to the measurements or the entire integration of the glow curve. A batch of TLD-100 micro-cube, with dimensions 1 mm x 1 mm x 1 mm and a Harshaw 2000 A/B TLD reader were used. For TLD-100 irradiations and positioning, Iodine-125 sources and a Solid Water phantom were used. With the appropriate electronic acquisition devices, connected to the Harshaw 2000 A/B, it was possible to read each signal individually. Both measurements methods presented acceptable regularity in the results. Therefore, for the dosimeters positioned distant from the source, large relatives differences among selected region (55 - 70 %) were observed. (author)

  1. Comparative studies on permanent prostate brachytherapy: pre-plan and real-time transrectal ultrasound guided iodine-125 seed implants at Korle-Bu Teaching Hospital, Ghana

    International Nuclear Information System (INIS)

    This research was carried out to investigate and compare the real-time and pre-plan implant at the Radiotherapy Department of the Korle Bu Teaching Hospital, Ghana. Prowess Panther 4.5 treatment planning system and variseed 7.2 software were used for pre-plan and real-time implant respectively. The study was conducted for eighty three (83) patients treated for prostate cancer through real-time implant brachytherapy between september, 2008 to April, 2013. Thirty one patients (31) patients whose ultrasound images were available were selected for the pre-plan study. The slices of ultrasound images were re-drawn on transparent A-4 sheets and later on scanned, contoured and registered in the treatment planning system (prowess 4.5). After planning, the volume to be implanted, total number of needles, seeds and the total activity of the source were displayed. Comparison was done withe the pre-plan and real-time implant. In both cases the variation was below 5% as recommended in dosimetry. About 30% - 40% of the imported seeds were left un-used due to over-estimation of seeds ordered from the manufacturer (BARD Company-USA). Hence this work (pre-plan) aims to solve this problem. The comparison for dosimetric parameters was assessed for prostate, urethra and rectum as (V 95%, V 100%, V 150%, D90Gy, D90%), (D90Gy, D90%, D30Gy, D30% ) and (V 100%, D30Gy and D30%) respectively and the variation were within the limit of ± 5%. Comparison of dosimetric values for this work were done with other institutions, like Karolinska university hospital, Sweden, The institute of Curie/ hospital Cochin Group Paris-France and European recommendations. The values reported at Korle - Bu teaching hospital (this work) were in good agreement with the international guidelines. (au)

  2. Modelling and measurement of inter-speed attenuation effects on dosimetry of I-125 seed implants for prostate brachytherapy

    International Nuclear Information System (INIS)

    Full text: TG43 based dose calculations for prostate permanent 1-125 seed implants ignore the effects of inter-seed attenuation (lSA). This study investigates the magnitude of ISA effects in simple seed arrangements and clinical implants using Monte Carlo (MC) simulation techniques. MC results are verified with experimental dose measurements. lSA effects for Oncura model 6711 and Thinseed (9011) are compared. MC simulations were performed with MCNPX v2.5.0. Seed models 6711 and 9011 were simulated singly to verify the accuracy of the model by comparison to previously published data. Then simple two seed arrangements and full clinical implant arrangements were simulated to assess ISA effects and consequences for typical patient DYH parameters. Experimental dose measurements using a MOSFET in a PMMA phantom were used to validate MC simulation results. Close agreement with published data was achieved for both seed models. Two seed arrangements demonstrate significant attenuation along the source transverse axis with the 90 II being slightly less attenuating. Clinical simulations show that ISA has significant effects on clinical dose-volume histogram (DYH) parameters. Experimental dose measurements agree with MC simulation results. Conclusion The study demonstrates the need to take account of ISA effects in permanent 1-125 seed implant treatments for accurate dosimetry. Ongoing work will investigate post implant dosimetry using MC simulation to determine in which circumstances ISA effects are clinically significant.

  3. Improved dose calculation accuracy for low energy brachytherapy by optimizing dual energy CT imaging protocols for noise reduction using sinogram affirmed iterative reconstruction.

    Science.gov (United States)

    Landry, Guillaume; Gaudreault, Mathieu; van Elmpt, Wouter; Wildberger, Joachim E; Verhaegen, Frank

    2016-03-01

    The goal of this study was to evaluate the noise reduction achievable from dual energy computed tomography (CT) imaging (DECT) using filtered backprojection (FBP) and iterative image reconstruction algorithms combined with increased imaging exposure. We evaluated the data in the context of imaging for brachytherapy dose calculation, where accurate quantification of electron density ρe and effective atomic number Zeff is beneficial. A dual source CT scanner was used to scan a phantom containing tissue mimicking inserts. DECT scans were acquired at 80 kVp/140Sn kVp (where Sn stands for tin filtration) and 100 kVp/140Sn kVp, using the same values of the CT dose index CTDIvol for both settings as a measure for the radiation imaging exposure. Four CTDIvol levels were investigated. Images were reconstructed using FBP and sinogram affirmed iterative reconstruction (SAFIRE) with strength 1,3 and 5. From DECT scans two material quantities were derived, Zeff and ρe. DECT images were used to assign material types and the amount of improperly assigned voxels was quantified for each protocol. The dosimetric impact of improperly assigned voxels was evaluated with Geant4 Monte Carlo (MC) dose calculations for an (125)I source in numerical phantoms. Standard deviations for Zeff and ρe were reduced up to a factor ∼2 when using SAFIRE with strength 5 compared to FBP. Standard deviations on Zeff and ρe as low as 0.15 and 0.006 were achieved for the muscle insert representing typical soft tissue using a CTDIvol of 40 mGy and 3mm slice thickness. Dose calculation accuracy was generally improved when using SAFIRE. Mean (maximum absolute) dose errors of up to 1.3% (21%) with FBP were reduced to less than 1% (6%) with SAFIRE at a CTDIvol of 10 mGy. Using a CTDIvol of 40mGy and SAFIRE yielded mean dose calculation errors of the order of 0.6% which was the MC dose calculation precision in this study and no error was larger than ±2.5% as opposed to errors of up to -4% with FPB. This

  4. Improved dose calculation accuracy for low energy brachytherapy by optimizing dual energy CT imaging protocols for noise reduction using sinogram affirmed iterative reconstruction

    International Nuclear Information System (INIS)

    The goal of this study was to evaluate the noise reduction achievable from dual energy computed tomography (CT) imaging (DECT) using filtered backprojection (FBP) and iterative image reconstruction algorithms combined with increased imaging exposure. We evaluated the data in the context of imaging for brachytherapy dose calculation, where accurate quantification of electron density ρe and effective atomic number Zeff is beneficial. A dual source CT scanner was used to scan a phantom containing tissue mimicking inserts. DECT scans were acquired at 80 kVp/140Sn kVp (where Sn stands for tin filtration) and 100 kVp/140Sn kVp, using the same values of the CT dose index CTDIvol for both settings as a measure for the radiation imaging exposure. Four CTDIvol levels were investigated. Images were reconstructed using FBP and sinogram affirmed iterative reconstruction (SAFIRE) with strength 1,3 and 5. From DECT scans two material quantities were derived, Zeff and ρe. DECT images were used to assign material types and the amount of improperly assigned voxels was quantified for each protocol. The dosimetric impact of improperly assigned voxels was evaluated with Geant4 Monte Carlo (MC) dose calculations for an 125I source in numerical phantoms. Standard deviations for Zeff and ρe were reduced up to a factor ∝2 when using SAFIRE with strength 5 compared to FBP. Standard deviations on Zeff and ρe as low as 0.15 and 0.006 were achieved for the muscle insert representing typical soft tissue using a CTDIvol of 40 mGy and 3 mm slice thickness. Dose calculation accuracy was generally improved when using SAFIRE. Mean (maximum absolute) dose errors of up to 1.3% (21%) with FBP were reduced to less than 1% (6%) with SAFIRE at a CTDIvol of 10 mGy. Using a CTDIvol of 40mGy and SAFIRE yielded mean dose calculation errors of the order of 0.6% which was the MC dose calculation precision in this study and no error was larger than ±2.5% as opposed to errors of up to -4% with FPB. This

  5. 106Ruthenium Brachytherapy for Retinoblastoma

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy of 106Ru plaque brachytherapy for the treatment of retinoblastoma. Methods and Materials: We reviewed a retrospective, noncomparative case series of 39 children with retinoblastoma treated with 106Ru plaques at the Jules-Gonin Eye Hospital between October 1992 and July 2006, with 12 months of follow-up. Results: A total of 63 tumors were treated with 106Ru brachytherapy in 41 eyes. The median patient age was 27 months. 106Ru brachytherapy was the first-line treatment for 3 tumors (4.8%), second-line treatment for 13 (20.6%), and salvage treatment for 47 tumors (74.6%) resistant to other treatment modalities. Overall tumor control was achieved in 73% at 1 year. Tumor recurrence at 12 months was observed in 2 (12.5%) of 16 tumors for which 106Ru brachytherapy was used as the first- or second-line treatment and in 15 (31.9%) of 47 tumors for which 106Ru brachytherapy was used as salvage treatment. Eye retention was achieved in 76% of cases (31 of 41 eyes). Univariate and multivariate analyses revealed no statistically significant risk factors for tumor recurrence. Radiation complications included retinal detachment in 7 (17.1%), proliferative retinopathy in 1 (2.4%), and subcapsular cataract in 4 (9.7%) of 41 eyes. Conclusion: 106Ru brachytherapy is an effective treatment for retinoblastoma, with few secondary complications. Local vitreous seeding can be successfully treated with 106Ru brachytherapy

  6. AB012. Brachytherapy for localized prostate cancer

    Science.gov (United States)

    Xu, Yong; Yang, Yong

    2016-01-01

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

  7. The incidence of radioepidermitis and the dose-response relationship in parotid gland cancer patients treated with 125I seed brachytherapy. Incidence of radioepidermitis and the dose-response relationship

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Ming-Hui; Zheng, Lei; Gao, Hong; Zhang, Jie; Liu, Shu-ming; Huang, Ming-wei; Shi, Yan [Peking University School and Hospital of Stomatology, Department of Oral and Maxillofacial Surgery, Beijing (China); Zhang, Jian-Guo [Peking University School and Hospital of Stomatology, Department of Oral and Maxillofacial Surgery, Beijing (China); Fujian Provincial Hospital, Fujian (China)

    2014-09-09

    We studied the incidence and dose-response relationship of radioepidermitis in parotid gland carcinoma patients treated with [{sup 125}I] seed brachytherapy in the hopes of designing an optimized pre-implant treatment plan that would reduce the incidence and severity of radioepidermitis in patients receiving this therapy. Between January 2007 and May 2010, 100 parotid gland cancer patients were treated postoperatively with [{sup 125}I] seed brachytherapy. The matched peripheral dose (MPD) was 80-140 Gy, and [{sup 125}I] seed activity was 0.7-0.8 mCi. The mean dose delivered to the skin was calculated in the post-implant CT on day 0 following implantation. Grades of acute and late dermatitis were evaluated at 2, 6, 12, and 18 months post-implantation. Most patients experienced grade 0-2 acute and late skin side effects (86 and 97 %, respectively), though a small subset developed severe complications. Most grade 1-3 effects resolved within 6 months of implantation, though some grade 1-3 effects and all grade 4 effects remained unchanged throughout the 18-month follow-up period. Grade 3 and 4 effects were most prominent (75 and 25 %, respectively) with doses of 110-140 Gy; doses higher than 140 Gy produced only grade 4 effects. [{sup 125}I] seed brachytherapy produced acceptable levels of acute and late radioepidermitis with a good clinical outcome. A mean dose under 100 Gy delivered to the skin was safe, though doses of 110-140 Gy should be given with caution and extra monitoring; doses greater than 140 Gy are dangerous and likely to produce grade 4-5 effects. (orig.) [German] Wir untersuchten die Inzidenz und die Dosis-Wirkung-Beziehung bei Patienten mit Ohrspeicheldruesenkrebs, die mit [{sup 125}I]-Seed-Brachytherapie behandelt wurden, in der Hoffnung, eine optimierte praeimplantologische Behandlung zu entwickeln, welche die Inzidenz und Schwere der Radioepidermitis bei Patienten, die diese Therapie erhalten haben, reduziert. Zwischen Januar 2007 und Mai 2010

  8. Rice and foxtail millet cultivation reconstructed from weed seed assemblages in the Chengtoushan site, central China

    International Nuclear Information System (INIS)

    Full text: Crop weeds have been successfully used for evaluation of farming practices in archaeological sites and reconstruction of the environmental condition. In rice agricultural sites in East Asia, however, a few studies of crop remains have been attempted. We evaluated the crop husbandry based on plant macrofossils including crop grains and weed seeds in the Chengtoushan site, Hunan Province, central China, which is one of the oldest rice agricultural site around the Yangtze River Basin. In the moat surrounding the site that is located on a loess plateau that juts out into the alluvial plain, we recognized three cultural layers during the Daxi Culture. Plant macrofossils in silty clay deposits in the moat consist of abundant rice and foxtail millet grains with many weed seeds. Radiocarbon age of these fossils shows that rice and foxtail millet cultivation dated back to 6400 cal. years B.P. The weed seed composition characterizes farmland and ruderal environments in the site surrounded by the moat. We assumed foxtail millet and rice cultivation practiced within the site on loess plateau, along with a paddy style rice cultivation in the alluvial lowland outside of the site. (author)

  9. Statistical differences and systematic effect on measurement procedure in thermoluminescent dosimetry of the Iodine-125 brachytherapy seed

    International Nuclear Information System (INIS)

    In order to provide the dosimetry for Iodine-125 seed production in Brazil, Harshaw thermoluminescent dosimeters (TLD-100) will be used. Even if measurements with TLD-100 of the same batch of fabrication are performed, the response will not be the same. As a consequence, they must be measured one by one. These dosimeters are LiF type with a micro-cube (1 mm x 1 mm x 1 mm) shape. Irradiations were performed using Iodine-125 seeds to guarantee the same absorbed dose of 5 Gy in each dosimeter. It has been used a Solid Water Phantom with three concentrically circle with 20 mm, 50 mm and 70 mm diameters. The angle of positions used was 0 deg, 30 deg, 60 deg and 90 deg. Of course there are 2 positions in 0 deg and 90 deg and 4 positions in 30 deg and 60 deg. These complete procedures were carried out five times in order to compare the data and minimize the systematic error. The iodine-125 seed used in the experiment was take off in each measure and put again turning his position 180 deg to guarantee the systematic error was minimized. This paper presents also a little discussion about the statistical difference in the measurement and the calculation procedure to determine the systematic error in these measurements. (author)

  10. Improved dose calculation accuracy for low energy brachytherapy by optimizing dual energy CT imaging protocols for noise reduction using sinogram affirmed iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Landry, Guillaume [Maastricht University Medical Center (Netherlands). Dept. of Radiation Oncology (MAASTRO); Munich Univ. (Germany). Dept. of Medical Physics; Gaudreault, Mathieu [Maastricht University Medical Center (Netherlands). Dept. of Radiation Oncology (MAASTRO); Laval Univ., QC (Canada). Dept. de Radio-Oncologie et Centre de Recherche en Cancerologie; Laval Univ., QC (Canada). Dept. de Physique, de Genie Physique et d' Optique; Elmpt, Wouter van [Maastricht University Medical Center (Netherlands). Dept. of Radiation Oncology (MAASTRO); Wildberger, Joachim E. [Maastricht University Medical Center (Netherlands). Dept. of Radiology; Verhaegen, Frank [Maastricht University Medical Center (Netherlands). Dept. of Radiation Oncology (MAASTRO); McGill Univ. Montreal, QC (Canada). Dept. of Oncology

    2016-05-01

    The goal of this study was to evaluate the noise reduction achievable from dual energy computed tomography (CT) imaging (DECT) using filtered backprojection (FBP) and iterative image reconstruction algorithms combined with increased imaging exposure. We evaluated the data in the context of imaging for brachytherapy dose calculation, where accurate quantification of electron density ρ{sub e} and effective atomic number Z{sub eff} is beneficial. A dual source CT scanner was used to scan a phantom containing tissue mimicking inserts. DECT scans were acquired at 80 kVp/140Sn kVp (where Sn stands for tin filtration) and 100 kVp/140Sn kVp, using the same values of the CT dose index CTDI{sub vol} for both settings as a measure for the radiation imaging exposure. Four CTDI{sub vol} levels were investigated. Images were reconstructed using FBP and sinogram affirmed iterative reconstruction (SAFIRE) with strength 1,3 and 5. From DECT scans two material quantities were derived, Z{sub eff} and ρ{sub e}. DECT images were used to assign material types and the amount of improperly assigned voxels was quantified for each protocol. The dosimetric impact of improperly assigned voxels was evaluated with Geant4 Monte Carlo (MC) dose calculations for an {sup 125}I source in numerical phantoms. Standard deviations for Z{sub eff} and ρ{sub e} were reduced up to a factor ∝2 when using SAFIRE with strength 5 compared to FBP. Standard deviations on Z{sub eff} and ρ{sub e} as low as 0.15 and 0.006 were achieved for the muscle insert representing typical soft tissue using a CTDI{sub vol} of 40 mGy and 3 mm slice thickness. Dose calculation accuracy was generally improved when using SAFIRE. Mean (maximum absolute) dose errors of up to 1.3% (21%) with FBP were reduced to less than 1% (6%) with SAFIRE at a CTDI{sub vol} of 10 mGy. Using a CTDI{sub vol} of 40mGy and SAFIRE yielded mean dose calculation errors of the order of 0.6% which was the MC dose calculation precision in this study and

  11. Radiation exposure to operating room staff during prostate brachytherapy using iodine-125 seeds; Exposition radiologique de l'equipe operatoire au cours de curietherapies de prostate par implants permanents d'iode-125

    Energy Technology Data Exchange (ETDEWEB)

    Gagna, G.; Amabile, J.C.; Laroche, P. [Service de protection radiologique des armees (SPRA), 1 bis rue du Lieutenant Raoul Batany, 92141 Clamart Cedex (France); Gauron, C. [Institut national de recherche et de securite (INRS), Departement Etudes et Assistance Medicales, 30 rue Olivier Noyer, 75680 Paris Cedex 14 (France)

    2011-04-15

    The French defense radiation protection service (SPRA) and the French national institute for research and safety (INRS) conducted a joint study to assess the radiation exposure to operating room staff during prostate brachytherapy using iodine-125 seeds at the Val-de-Grace military hospital. The purpose of the study was the assessment of the effective doses, the equivalent doses to the extremities and lens received by a novice team, the different ambient dose equivalent rates measurements and the delineation of areas. After six brachy-therapies, all the recorded doses with whole-body InLight{sup R} OSL and nanoDot{sup R} dosimeters remained below the detection limit for the whole staff. The dose rate measured at the end of implantation by an AT1123{sup R} survey meter is about 170 {mu}Sv/h at the perineum of the patient. The controlled area limit is estimated to be about 20 cm from the patient perineum. From these results, the authors propose recommendations for the categorization of workers, the delineation of areas and the dose monitoring procedures. This study demonstrates that real-time ultrasound-guided trans-perineal prostate brachytherapy delivers low dose to the operators because of the radioactive source characteristics and the instrumentation providing an effective radiation protection for the surgical team. (authors)

  12. Brachytherapy with Iodine-125 seeds in initial prostate cancer treatment: preliminary results and complications; Braquiterapia com sementes de Iodo-125 no tratamento do cancer inicial de prostata: resultados e complicacoes preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Penna, Antonio Belmiro R. Campbell [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Programa de Pos-graduacao em Radiologia]. E-mail: info@radiobot.com.br; Bernabe, Antonio Jose S. [Sociedade Brasileira de Urologia, Rio de Janeiro, RJ (Brazil); Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia

    2005-07-01

    Low-dose rate brachytherapy as monotherapy is a treatment option for early stage prostate cancer. It consists of the permanent implantation of Iodine-125 seeds in the gland of patients with PSA{<=} 10ng/ml, Gleason {<=} 6 and clinical stage from T1 until T2b. The 68 patients enrolled in this study were treated by the technique developed at the Northwest Pacific Hospital, Seattle, USA. Sixty four patients treated with low-dose rate brachytherapy were followed for 4-48 months (median = 32 months). The treatment results were based on the periodic evaluation of the total PSA values and it was found that, after this time, 55% of patients had total PSA equal or below 1ng/ml. Post-implant morbidities were evaluated, showing that 89% presented negligible or low grade side effects. Low-dose rate brachytherapy is an appealing option for the treatment of early stage prostate cancer because of its successful local control and low morbidity. (author)

  13. Implementation and Performance of the Seeded Reconstruction for the ATLAS Event Filter Selection Software

    CERN Document Server

    Santamarina-Rios, C; Dos Anjos, A; Armstrong, S; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, J A C; Bosman, M; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Comune, G; Crone, G; Damazio, D; De Santo, A; Díaz-Gómez, M; Di Mattia, A; Ellis, Nick; Emeliyanov, D; Epp, B; Falciano, S; Garitaonandia, H; George, S; Gesualdi-Mello, A; Ghete, V; Goncalo, R; Haller, J; Kabana, S; Khomich, A; Kilvington, G; Kirkc, J; Konstantinidis, N P; Kootz, A; Lankford, AJ; Lowe, A; Luminari, L; Maeno, T; Masik, J; Meessen, C; Moore, R; Morettini, P; Negri, A; Nikitin, N; Nisati, A; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pérez-Réale, V; Pinfold, James L; Pinto, P; Qian, Z; Resconi, S; Rosati, S; Sánchez, C; Scannicchio, D A; Schiavi, C; Segura, E; De Seixas, J M; Sivoklokov, S Yu; Sobreira, A; Soluk, R A; Stefanidis, E; Sushkov, S; Sutton, M; Tapprogge, S; Tarem, S; Thomas, E; Touchard, F; Usai, G; Venda-Pinto, B; Ventura, A; Vercesi, V; Wengler, T; Werner, P; Wheeler, S J; Wickens, F J; Wiedenmann, W; Wielers, M; Zobernig, G; 14th IEEE-NPSS Real Time Conference 2005

    2007-01-01

    ATLAS is one of the four LHC experiments that will start data taking in 2007, designed to cover a wide range of physics topics. The ATLAS trigger system has to cope with a rate of 40 MHz and 23 interactions per bunch crossing. It is divided in three different levels. The first one (hardware based) provides a signature that is confirmed by the the following trigger levels (software based) by running a sequence of algorithms and validating the signal step by step, looking only to the region of the space indicated by the first trigger level (seeding). In this paper, the performance of one of these sequences that run at the Event Filter level (third level) and is composed of clustering at the calorimeter, track reconstruction and matching.

  14. 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.

  15. An image-guidance system for dynamic dose calculation in prostate brachytherapy using ultrasound and fluoroscopy

    International Nuclear Information System (INIS)

    Purpose: Brachytherapy is a standard option of care for prostate cancer patients but may be improved by dynamic dose calculation based on localized seed positions. The American Brachytherapy Society states that the major current limitation of intraoperative treatment planning is the inability to localize the seeds in relation to the prostate. An image-guidance system was therefore developed to localize seeds for dynamic dose calculation. Methods: The proposed system is based on transrectal ultrasound (TRUS) and mobile C-arm fluoroscopy, while using a simple fiducial with seed-like markers to compute pose from the nonencoded C-arm. Three or more fluoroscopic images and an ultrasound volume are acquired and processed by a pipeline of algorithms: (1) seed segmentation, (2) fiducial detection with pose estimation, (3) seed matching with reconstruction, and (4) fluoroscopy-to-TRUS registration. Results: The system was evaluated on ten phantom cases, resulting in an overall mean error of 1.3 mm. The system was also tested on 37 patients and each algorithm was evaluated. Seed segmentation resulted in a 1% false negative rate and 2% false positive rate. Fiducial detection with pose estimation resulted in a 98% detection rate. Seed matching with reconstruction had a mean error of 0.4 mm. Fluoroscopy-to-TRUS registration had a mean error of 1.3 mm. Moreover, a comparison of dose calculations between the authors’ intraoperative method and an independent postoperative method shows a small difference of 7% and 2% forD90 and V100, respectively. Finally, the system demonstrated the ability to detect cold spots and required a total processing time of approximately 1 min. Conclusions: The proposed image-guidance system is the first practical approach to dynamic dose calculation, outperforming earlier solutions in terms of robustness, ease of use, and functional completeness

  16. Seed migration after transperineal interstitial prostate brachytherapy by using loose seeds: Japanese prostate cancer outcome study of permanent iodine-125 seed implantation (J-POPS) multi-institutional cohort study

    International Nuclear Information System (INIS)

    The incidence and associated factors of loose seed migration were investigated in cohort 1 of the Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS). The study subjects were 2160 patients, consisting of 1641 patients who underwent permanent iodine-125 seed implantation (PI) and 519 patients who underwent PI combined with external beam radiation therapy (PI + EBRT). The presence or absence of seed migration to the chest and abdominal/pelvic region was determined. Seed migration was observed in 22.7 % of PI group patients and 18.1 % of PI + EBRT group patients (p = 0.0276). Migration to the lungs and abdominal/pelvic region was observed in 14.6 % and 11.1 % of the patients in the PI group, and 11.2 % and 8.5 % of the patients in the PI + EBRT group, respectively. In the PI group, the number of implanted seeds was associated with the seed migration incidence. Neither the PI nor the PI + EBRT group showed any difference in the volume of the prostate receiving 100 % of the prescribed dose (V100 [%]) or the minimal dose received by 90 % of the prostate volume (D90 [Gy]) between the patients with and without seed migration. This prospective cohort study investigating the largest number of past cases showed no difference in D90 (Gy) or V100 (%) between seed migration or the absence thereof in both the PI group and PI + EBRT group

  17. Development of an automation system for iodine-125 brachytherapy seed production by (Nd:YAG) laser welding; Automacao do processo de soldagem a laser (Nd:YAG) para confeccao das sementes de iodo-125 utilizadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir Luiz

    2010-07-01

    The aim of this work is to develop an automation system for iodine-125 radioactive seed production by (Nd:YAG) laser welding, which has been used successfully in Low Dose Rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8mm in diameter and 4.5mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at IPEN-CNEN/SP imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources becomes a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a largest number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with Good Manufacturing Practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing Programmable Logic Controller (PLC), stepper motors, drivers, (Nd:YAG) laser welding machine, photoelectric sensors and supervisory. (author)

  18. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy

    International Nuclear Information System (INIS)

    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 192Ir and 60Co sources, and permanent seed implants with 125I, 103Pd and 131Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with 125I, 106Ru, 90Sr) 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 dosimeter with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Moutinho, L.M., E-mail: moutinho@ua.pt [i3N, Physics Department, University of Aveiro (Portugal); Castro, I.F.C. [i3N, Physics Department, University of Aveiro (Portugal); Peralta, L. [Faculdade de Ciências da Universidade de Lisboa (Portugal); Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Abreu, M.C. [Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Veloso, J.F.C.A. [i3N, Physics Department, University of Aveiro (Portugal)

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40–50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25–100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  20. Brachytherapy dosimeter with silicon photomultipliers

    Science.gov (United States)

    Moutinho, L. M.; Castro, I. F. C.; Peralta, L.; Abreu, M. C.; Veloso, J. F. C. A.

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40-50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25-100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  1. Three-dimensional verification of 125I seed stability after permanent implantation in the parotid gland and periparotid region

    International Nuclear Information System (INIS)

    To evaluate seed stability after permanent implantation in the parotid gland and periparotid region via a three-dimensional reconstruction of CT data. Fifteen patients treated from June 2008 to June 2012 at Peking University School and Hospital of Stomatology for parotid gland tumors with postoperative adjunctive 125I interstitial brachytherapy were retrospectively reviewed in this study. Serial CT data were obtained during follow-up. Mimics and Geomagic Studio software were used for seed reconstruction and stability analysis, respectively. Seed loss and/or migration outside of the treated area were absent in all patients during follow-up (23–71 months). Total seed cluster volume was maximized on day 1 post-implantation due to edema and decreased significantly by an average of 13.5 % (SD = 9.80 %; 95 % CI, 6.82–17.68 %) during the first two months and an average of 4.5 % (SD = 3.60 %; 95 % CI, 2.29–6.29 %) during the next four months. Volume stabilized over the subsequent six months. 125I seed number and location were stable with a general volumetric shrinkage tendency in the parotid gland and periparotid region. Three-dimensional seed reconstruction of CT images is feasible for visualization and verification of implanted seeds in parotid brachytherapy

  2. SU-D-BRF-07: Ultrasound and Fluoroscopy Based Intraoperative Image-Guidance System for Dynamic Dosimetry in Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, N; Le, Y; Deguet, A; Prince, J; Song, D; Lee, J [Johns Hopkins University, Baltimore, MD (United States); Dehghan, E [Philips Research North America, Briarcliff Manor, NY (United States); Burdette, E [Acoustic MedSystems Inc., Savoy, IL (United States); Fichtinger, G [Queen' s University, Kingston, ON (Canada)

    2014-06-01

    Purpose: Prostate brachytherapy is a common treatment method for low-risk prostate cancer patients. Intraoperative treatment planning is known to improve the treatment procedure and the outcome. The current limitation of intraoperative treatment planning is the inability to localize the seeds in relation to the prostate. We developed an image-guidance system to fulfill this need to achieve intraoperative dynamic dosimetry in prostate brachytherapy. Methods: Our system is based on standard imaging equipments available in the operating room, including the transrectal ultrasound (TRUS) and the mobile C-arm. A simple fiducial is added to compute the C-arm pose. Three fluoroscopic images and an ultrasound volume of the seeds and the prostate are acquired and processed by four image processing algorithms: seed segmentation, fiducial detection with pose estimation, seed reconstruction, and seeds-to-TRUS registration. The updated seed positions allow the physician to assess the quality of implantation and dynamically adjust the treatment plan during the course of surgery to achieve improved exit dosimetry. Results: The system was tested on 10 phantoms and 37 patients. Seed segmentation resulted in a 1% false negative and 2% false positive rates. Fiducial detection with pose estimation resulted in a detection rate of 98%. Seed reconstruction had a mean reconstruction error of 0.4 mm. Seeds-to-TRUS registration had a mean registration error of 1.3 mm. The total processing time from image acquisition to registration was approximately 1 minute. Conclusion: We present an image-guidance system for intraoperative dynamic dosimetry in prostate brachytherapy. Using standard imaging equipments and a simple fiducial, our system can be easily adopted in any clinics. Robust image processing algorithms enable accurate and fast computation of the delivered dose. Especially, the system enables detection of possible hot/cold spots during the surgery, allowing the physician to address these

  3. SU-D-BRF-07: Ultrasound and Fluoroscopy Based Intraoperative Image-Guidance System for Dynamic Dosimetry in Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Prostate brachytherapy is a common treatment method for low-risk prostate cancer patients. Intraoperative treatment planning is known to improve the treatment procedure and the outcome. The current limitation of intraoperative treatment planning is the inability to localize the seeds in relation to the prostate. We developed an image-guidance system to fulfill this need to achieve intraoperative dynamic dosimetry in prostate brachytherapy. Methods: Our system is based on standard imaging equipments available in the operating room, including the transrectal ultrasound (TRUS) and the mobile C-arm. A simple fiducial is added to compute the C-arm pose. Three fluoroscopic images and an ultrasound volume of the seeds and the prostate are acquired and processed by four image processing algorithms: seed segmentation, fiducial detection with pose estimation, seed reconstruction, and seeds-to-TRUS registration. The updated seed positions allow the physician to assess the quality of implantation and dynamically adjust the treatment plan during the course of surgery to achieve improved exit dosimetry. Results: The system was tested on 10 phantoms and 37 patients. Seed segmentation resulted in a 1% false negative and 2% false positive rates. Fiducial detection with pose estimation resulted in a detection rate of 98%. Seed reconstruction had a mean reconstruction error of 0.4 mm. Seeds-to-TRUS registration had a mean registration error of 1.3 mm. The total processing time from image acquisition to registration was approximately 1 minute. Conclusion: We present an image-guidance system for intraoperative dynamic dosimetry in prostate brachytherapy. Using standard imaging equipments and a simple fiducial, our system can be easily adopted in any clinics. Robust image processing algorithms enable accurate and fast computation of the delivered dose. Especially, the system enables detection of possible hot/cold spots during the surgery, allowing the physician to address these

  4. BrachyView: Proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Petasecca, M.; Loo, K. J.; Safavi-Naeini, M.; Han, Z.; Metcalfe, P. E.; Lerch, M. L. F.; Qi, Y.; Rosenfeld, A. B. [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Meikle, S. [Brain and Mind Research Institute, University of Sydney, NSW 2006, Australia and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Pospisil, S.; Jakubek, J. [Institute of Experimental and Applied Physics, Czech Technical University of Prague, Prague (Czech Republic); Bucci, J. A. [St George Cancer Care Centre, St George Hospital, Kogarah, NSW 2217 (Australia); Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021 (United States)

    2013-04-15

    Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. Methods: BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. Results: The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5-3 mm for a 10-60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for real

  5. BrachyView: Proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. Methods: BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. Results: The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5–3 mm for a 10–60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for

  6. Sci—Fri PM: Topics — 08: The Role and Benefits of Electromagnetic Needle-Tracking Technologies in Brachytherapy

    International Nuclear Information System (INIS)

    In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm3). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications

  7. Sci—Fri PM: Topics — 08: The Role and Benefits of Electromagnetic Needle-Tracking Technologies in Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Beaulieu, L.; Racine, E.; Boutaleb, S.; Filion, O. [Département de Radio-Oncologie et Centre de Recherche du CHU de Québec, CHU de Québec, Québec (Québec), and Département de Physique, de Génie Physique et d' Optique et Centre de recherche en sur le Cancer, Université Laval, Québec (Québec) (Canada); Poulin, E.; Hautvast, G. [Biomedical Systems, Philips Group Innovation, High Tech Campus 34 (HTC 34), Eindhoven (Netherlands); Binnekamp, D. [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best (Netherlands)

    2014-08-15

    In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm{sup 3}). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications.

  8. 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

  9. Use of Integra® and Interval Brachytherapy in a Two-Staged Auricular Reconstruction Following Excision of a Recurrent Keloid

    OpenAIRE

    Alyssa J. Reiffel; Sohn, Allie M.; Henderson, Peter W.; Fullerton, Natalia; Spector, Jason A.

    2012-01-01

    Keloids present a formidable clinical challenge. Surgical excision in conjunction with radiation therapy may decrease the chance of keloid recurrence. Split-thickness skin grafts, however, are more prone to failure in the setting of radiation. In this report, we present a patient with a recurrent auricular keloid who underwent excision and immediate Integra® application, followed by high dose rate brachytherapy and interval split-thickness skin graft placement. A 23-year old female with a his...

  10. Dosimetric results in implant and post-implant and low rate in brachytherapy prostate cancer with loose seeds and attached; Resultados dosimetricos en el implante y post-impante en braquiterapia de baja tasa en cancer de prostata con semillas sueltas y unidas

    Energy Technology Data Exchange (ETDEWEB)

    Juan-Senabre, X. J.; Albert Antequera, M.; Lopez-Tarjuelo, J.; Santos Serra, A.; Perez-Mestre, M.; Sanchez Iglesias, A. L.; Conde Moreno, A. J.; Gonzalez Vidal, V.; Beltran Persiva, J.; Muelas Soria, R.; Ferrer Albiach, C.

    2015-07-01

    The objective is determine differences dosimetry statistics on the dosimetry of the implant and post-implant in brachytherapy of low rate with implants permanent in prostate using seed of 125-I loose and attached Both in lives and in the post-prostatic plans dosimetric coverage is good and restrictions in urethra and rectum for both groups of patients are met. Not migrating with joined is evident, as well as better dosimetric homogeneity. (Author)

  11. Monte Carlo calculation of dosimetric parameters of a {sup 125}I brachytherapy seed encapsulation with biocompatible polymer and a ceramic matrix as radiographic marker

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lucas P.; Santos, Adriano M.; Grynberg, Suely E., E-mail: lpr@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Dosimetria e Simulacao Computacional; Facure, Alessandro, E-mail: facure@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    For prostate cancer treatments, there is an increasing interest in the permanent radioactive seeds implant technique. Currently, in Brazil, the seeds are imported at high prices, which prohibit their use in public hospitals. One of the seed models that have been developed at CDTN has a ceramic matrix as a radioisotope carrier and a radiographic marker; the seed is encapsulated with biocompatible polymer. In this work, Monte Carlo simulations were performed in order to assess the dose distributions generated by the prototype seed model. The obtained data was assessed as described in the TG-43U1 report by the AAPM. The dosimetric parameters dose rate constant, {Lambda}, radial dose function, g{sub L}(r), and anisotropy function, F(r,{theta}), were derived from simulations using the MCNP5 code. The function g(r) shows that the seed has a lower decrease in dose rate on its transverse axis when compared to the 6711 model (one of the most used seeds in permanent prostate implants). F(r,{theta}) shows that CDTN's seed anisotropy curves are smoother than the 6711 model curves for {theta}{<=}20 deg and 0.25{<=}r{<=}1 cm. As well, the {Lambda} value is 15% lower than the {Lambda} value of 6711. The results show that CDTN's seed model can deposit a more isotropic dose. Because of the model's characteristics, the seeds can be impregnated with iodine of lower specific activity which would help reducing costs. (author)

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

    Science.gov (United States)

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

    2015-09-01

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

  13. Prostate brachytherapy

    Science.gov (United States)

    ... make you drowsy and numbing medicine on your perineum. This is the area between the anus and ... placed with needles or special applicators through your perineum. Placing the seeds may hurt a little (if ...

  14. Brachytherapy with Iodine-125 seeds strand for treatment of main portal vein tumor thrombi: an experimental study in a rabbit model

    OpenAIRE

    Zhang, Wen; Luo, Jianjun; Liu, Qingxin; Ma, Jingqin; Qu, Xudong; Yang, Minjie; Yan, Zhiping; Wang, Jianhua

    2016-01-01

    This study aims to establish an animal model of implanted main portal vein tumor thrombus (MPVTT) and to evaluate safety and efficacy of brachy therapy with Iodine-125 (125I) seeds strand to treat MPVTT of rabbit. VX2 tumor thrombus was implanted in main portal vein (MPV) of 32 New Zealand white rabbits. These rabbits were randomly divided into treatment group (Group T, T1-T16) and control group (Group C, C1-C16). 125I seeds and blank seeds strand were implanted in MPV of rabbits in Group T a...

  15. Rectal function following prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Quality of life following therapeutic intervention for carcinoma of the prostate gland has not been well documented. In particular, a paucity of data has been published regarding bowel function following prostate brachytherapy. This study evaluated late bowel function in 209 consecutive prostate brachytherapy patients via a one-time questionnaire administered 16-55 months postimplant. Materials and Methods: Two hundred nineteen consecutive patients underwent permanent prostate brachytherapy from April 1995 through February 1998 using either 125I or 103Pd for clinical T1c-T3a carcinoma of the prostate gland. Of the 219 patients, 7 had expired. Of the remaining 212 patients (median follow-up, 28 months), each patient was mailed a self-administered questionnaire (10 questions) with a prestamped return envelope; 209 (98.6%) surveys were returned. Clinical parameters evaluated for bowel dysfunction included patient age, diabetes, hypertension, history of tobacco consumption, clinical T-stage, elapsed time since implant, and prostate ultrasound volume. Treatment parameters included utilization of neoadjuvant hormonal manipulation, utilization of moderate dose external beam radiation therapy prior to implantation, choice of isotope (125I vs. 103Pd), rectal dose (average, median and maximum doses), total implanted seed strength, values of the minimum dose received by 90% of the prostate gland (D90), and the percent prostate volume receiving 100%, 150%, and 200% of the prescribed minimum peripheral dose (V100, V150 and V200, respectively). Because detailed baseline bowel function was not available for these patients, a cross-sectional survey was performed in which 30 newly diagnosed prostate cancer patients of comparable demographics served as controls. Results: The total rectal function scores for the brachytherapy and control patients were 4.3 and 1.6, respectively, out of a total 27 points (p 103Pd resulted in lower radiation doses to the rectum, the choice of

  16. Urethral reconstruction with a 3D porous bacterial cellulose scaffold seeded with lingual keratinocytes in a rabbit model.

    Science.gov (United States)

    Huang, Jian-Wen; Lv, Xiang-Guo; Li, Zhe; Song, Lu-Jie; Feng, Chao; Xie, Min-Kai; Li, Chao; Li, Hong-Bin; Wang, Ji-Hong; Zhu, Wei-Dong; Chen, Shi-Yan; Wang, Hua-Ping; Xu, Yue-Min

    2015-09-01

    The goal of this study was to evaluate the effects of urethral reconstruction with a three-dimensional (3D) porous bacterial cellulose (BC) scaffold seeded with lingual keratinocytes in a rabbit model. A novel 3D porous BC scaffold was prepared by gelatin sponge interfering in the BC fermentation process. Rabbit lingual keratinocytes were isolated, expanded, and seeded onto 3D porous BC. BC alone (group 1, N  =  10), 3D porous BC alone (group 2, N  =  10), and 3D porous BC seeded with lingual keratinocytes (group 3, N  =  10) were used to repair rabbit ventral urethral defects (2.0   ×   0.8 cm). Scanning electron microscopy revealed that BC consisted of a compact laminate while 3D porous BC was composed of a porous sheet buttressed by a dense outer layer. The average pore diameter and porosity of the 3D porous BC were 4.23   ±   1.14 μm and 67.00   ±   6.80%, respectively. At 3 months postoperatively, macroscopic examinations and retrograde urethrograms of urethras revealed that all urethras maintained wide calibers in group 3. Strictures were found in all rabbits in groups 1 and 2. Histologically, at 1 month postoperatively, intact epithelium occurred in group 3, and discontinued epithelium was found in groups 1 and 2. However, groups 2 and 3 exhibited similar epithelial regeneration, which was superior to that of group 1 at 3 months (p  <  0.05). Comparisons of smooth muscle content and endothelia density among the three groups revealed a significant increase at each time point (p  <  0.05). Our results demonstrated that 3D porous BC seeded with lingual keratinocytes enhanced urethral tissue regeneration. 3D porous BC could potentially be used as an optimized scaffold for urethral reconstruction. PMID:26358641

  17. Transperineal prostate brachytherapy, using I-125 seed with or without adjuvant androgen deprivation, in patients with intermediate-risk prostate cancer: study protocol for a phase III, multicenter, randomized, controlled trial

    Directory of Open Access Journals (Sweden)

    Miyakoda Keiko

    2010-10-01

    Full Text Available Abstract Background The optimal protocol for 125I-transperineal prostatic brachytherapy (TPPB in intermediate-risk prostate cancer (PCa patients remains controversial. Data on the efficacy of combining androgen-deprivation therapy (ADT with 125I-TPPB in this group remain limited and consequently the guidelines of the American Brachytherapy Society (ABS provide no firm recommendations. Methods/Design Seed and Hormone for Intermediate-risk Prostate Cancer (SHIP 0804 is a phase III, multicenter, randomized, controlled study that will investigate the impact of adjuvant ADT following neoadjuvant ADT and 125I-TPPB. Prior to the end of March, 2011, a total of 420 patients with intermediate-risk, localized PCa will be enrolled and randomized to one of two treatment arms. These patients will be recruited from 20 institutions, all of which have broad experience of 125I-TPPB. Pathological slides will be centrally reviewed to confirm patient eligibility. The patients will initially undergo 3-month ADT prior to 125I-TPPB. Those randomly assigned to adjuvant therapy will subsequently undergo 9 months of adjuvant ADT. All participants will be assessed at baseline and at the following intervals: every 3 months for the first 24 months following 125I-TPPB, every 6 months during the 24- to 60-month post-125I-TPPB interval, annually between 60 and 84 months post-125I-TPPB, and on the 10th anniversary of treatment. The primary endpoint is biochemical progression-free survival (BPFS. Secondary endpoints are overall survival (OS, clinical progression-free survival, disease-specific survival, salvage therapy non-adaptive interval, acceptability (assessed using the international prostate symptom score [IPSS], quality of life (QOL evaluation, and adverse events. In the correlative study (SHIP36B, we also evaluate biopsy results at 36 months following treatment to examine the relationship between the results and the eventual recurrence after completion of radiotherapy

  18. Transperineal prostate brachytherapy, using I-125 seed with or without adjuvant androgen deprivation, in patients with intermediate-risk prostate cancer: study protocol for a phase III, multicenter, randomized, controlled trial

    International Nuclear Information System (INIS)

    The optimal protocol for 125I-transperineal prostatic brachytherapy (TPPB) in intermediate-risk prostate cancer (PCa) patients remains controversial. Data on the efficacy of combining androgen-deprivation therapy (ADT) with 125I-TPPB in this group remain limited and consequently the guidelines of the American Brachytherapy Society (ABS) provide no firm recommendations. Seed and Hormone for Intermediate-risk Prostate Cancer (SHIP) 0804 is a phase III, multicenter, randomized, controlled study that will investigate the impact of adjuvant ADT following neoadjuvant ADT and 125I-TPPB. Prior to the end of March, 2011, a total of 420 patients with intermediate-risk, localized PCa will be enrolled and randomized to one of two treatment arms. These patients will be recruited from 20 institutions, all of which have broad experience of 125I-TPPB. Pathological slides will be centrally reviewed to confirm patient eligibility. The patients will initially undergo 3-month ADT prior to 125I-TPPB. Those randomly assigned to adjuvant therapy will subsequently undergo 9 months of adjuvant ADT. All participants will be assessed at baseline and at the following intervals: every 3 months for the first 24 months following 125I-TPPB, every 6 months during the 24- to 60-month post-125I-TPPB interval, annually between 60 and 84 months post-125I-TPPB, and on the 10th anniversary of treatment. The primary endpoint is biochemical progression-free survival (BPFS). Secondary endpoints are overall survival (OS), clinical progression-free survival, disease-specific survival, salvage therapy non-adaptive interval, acceptability (assessed using the international prostate symptom score [IPSS]), quality of life (QOL) evaluation, and adverse events. In the correlative study (SHIP36B), we also evaluate biopsy results at 36 months following treatment to examine the relationship between the results and the eventual recurrence after completion of radiotherapy. These two multicenter trials (SHIP0804 & SHIP36

  19. Methods for prostate stabilization during transperineal LDR brachytherapy

    International Nuclear Information System (INIS)

    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

  20. Cold spot mapping inferred from MRI at time of failure predicts biopsy-proven local failure after permanent seed brachytherapy in prostate cancer patients: Implications for focal salvage brachytherapy

    International Nuclear Information System (INIS)

    Background and purpose: (1) To establish a method to evaluate dosimetry at the time of primary prostate permanent implant (pPPI) using MRI of the shrunken prostate at the time of failure (tf). (2) To compare cold spot mapping with sextant-biopsy mapping at tf. Material and methods: Twenty-four patients were referred for biopsy-proven local failure (LF) after pPPI. Multiparametric MRI and combined-sextant biopsy with a central review of the pathology at tf were systematically performed. A model of the shrinking pattern was defined as a Volumetric Change Factor (VCF) as a function of time from time of pPPI (t0). An isotropic expansion to both prostate volume (PV) and seed position (SP) coordinates determined at tf was performed using a validated algorithm using the VCF. Results: pPPI CT-based evaluation (at 4 weeks) vs. MR-based evaluation: Mean D90% was 145.23 ± 19.16 Gy [100.0–167.5] vs. 85.28 ± 27.36 Gy [39–139] (p = 0.001), respectively. Mean V100% was 91.6 ± 7.9% [70–100%] vs. 73.1 ± 13.8% [55–98%] (p = 0.0006), respectively. Seventy-seven per cent of the pathologically positive sextants were classified as cold. Conclusions: Patients with biopsy-proven LF had poorer implantation quality when evaluated by MRI several years after implantation. There is a strong relationship between microscopic involvement at tf and cold spots

  1. Radiation Protection in Brachytherapy in the Next Decade

    International Nuclear Information System (INIS)

    Brachytherapy procedures are increasing in number, and account for an important share of radiation exposure in medicine at a time when there is a dramatic rise in cancer across the developing world. Important areas in relation to radiation safety in brachytherapy include that all efforts be made to ensure that protection in the treatment is optimized and all measures are taken to prevent accidental exposures from occurring. Historical and ongoing accidents that have resulted in patient and public doses or inappropriate medical outcomes represent opportunities for continuous improvement in radiation protection. Additionally, staff in brachytherapy treatment facilities may receive high radiation doses if radiological protection tools are not used properly. Brachytherapy uniquely presents the possibility for doses that require active management. In modern brachytherapy centres, radiation doses are incurred by staff (e.g. loading of seeds, plaques, caesium implants, associated fluoroscopy). There is also a large variation in the practice of brachytherapy on a global scale and several facilities still practise older techniques with significantly higher staff dose potential. In addition, technological developments and newer techniques present new radiation protection concerns and an increasing blurring of historical responsibilities that need to be addressed with specific recommendations for the practising medical community. Along with an increase in equipment and to safeguard resources, additional qualified and trained brachytherapy staff are required worldwide. (author)

  2. The dosimetry of brachytherapy-induced erectile dysfunction

    International Nuclear Information System (INIS)

    There is emerging evidence that brachytherapy-induced erectile dysfunction (ED) is technique-related and may be minimized by careful attention to source placement. Herein, we review the relationship between radiation doses to the prostate gland/surrounding structures and the development of brachytherapy-induced ED. The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness. Although the site-specific structure associated with brachytherapy-induced ED remains unknown, there is an increasing body of data implicating the proximal penis. With day 0 CT-based dosimetry, the dose to 50% (D50) and 25% (D25) of the bulb of the penis should be maintained below 40% and 60% mPD, respectively, while the crura D50 should be maintained below 28% mPD to maximize post-brachytherapy potency. To date, there is no data to suggest that either radiation doses to the neurovascular bundles or choice of isotope is associated with brachytherapy-induced ED, while conflicting data has been reported regarding radiation dose to the prostate and the use of supplemental external beam radiation therapy. Although the etiology of brachytherapy-induced ED is likely multifactorial, the available data supports the proximal penis as an important site-specific structure. Refinements in implant technique, including preplanning and intraoperative seed placement, will result in lower radiation doses to the proximal penis with potential improvement in potency preservation

  3. An algorithm for efficient metal artifact reductions in permanent seed implants

    Energy Technology Data Exchange (ETDEWEB)

    Xu Chen; Verhaegen, Frank; Laurendeau, Denis; Enger, Shirin A.; Beaulieu, Luc [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie, Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Cote du Palais, Quebec, Quebec G1R 2J6 (Canada) and Departement de Genie Electrique et Genie Informatique, Laboratoire de Vision et Systemes Numeriques, Universite Laval, Quebec, Quebec G1K 7P4 (Canada); Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands) and Oncology Department, Montreal General Hospital, McGill University, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Departement de Genie Electrique et Genie Informatique, Laboratoire de Vision et Systemes Numeriques, Universite Laval, Quebec, Quebec G1K 7P4 (Canada); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie, Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Co circumflex te du Palais, Quebec, Quebec G1R 2J6 (Canada); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie, Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Cote du Palais, Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada)

    2011-01-15

    Purpose: In permanent seed implants, 60 to more than 100 small metal capsules are inserted in the prostate, creating artifacts in x-ray computed tomography (CT) imaging. The goal of this work is to develop an automatic method for metal artifact reduction (MAR) from small objects such as brachytherapy seeds for clinical applications. Methods: The approach for MAR is based on the interpolation of missing projections by directly using raw helical CT data (sinogram). First, an initial image is reconstructed from the raw CT data. Then, the metal objects segmented from the reconstructed image are reprojected back into the sinogram space to produce a metal-only sinogram. The Steger method is used to determine precisely the position and edges of the seed traces in the raw CT data. By combining the use of Steger detection and reprojections, the missing projections are detected and replaced by interpolation of non-missing neighboring projections. Results: In both phantom experiments and patient studies, the missing projections have been detected successfully and the artifacts caused by metallic objects have been substantially reduced. The performance of the algorithm has been quantified by comparing the uniformity between the uncorrected and the corrected phantom images. The results of the artifact reduction algorithm are indistinguishable from the true background value. Conclusions: An efficient algorithm for MAR in seed brachytherapy was developed. The test results obtained using raw helical CT data for both phantom and clinical cases have demonstrated that the proposed MAR method is capable of accurately detecting and correcting artifacts caused by a large number of very small metal objects (seeds) in sinogram space. This should enable a more accurate use of advanced brachytherapy dose calculations, such as Monte Carlo simulations.

  4. 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.

    2012-06-01

    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.

  5. 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

  6. 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)

  7. Early voiding dysfunction associated with prostate brachytherapy.

    Science.gov (United States)

    Wagner; Nag; Young; Bahnson

    2000-12-15

    Introduction: Transperineal prostate brachytherapy is gaining popularity as a treatment for clinically localized carcinoma of the prostate. Very little prospective data exists addressing the issue of complications associated with this procedure. We present an analysis of the early voiding dysfunction associated with prostate brachytherapy. Materials and Methods: Forty-six consecutive patients who underwent Palladium-103 (Pd-103) seed placement for clinically localized prostate carcinoma were evaluated prospectively for any morbidity associated with the procedure. Twenty-three patients completed an International Prostate Symptom Score (IPSS) questionnaire preoperatively, at their first postoperative visit, and at their second postoperative visit. The total IPSS, each of the seven individual components, and the "bother" score were evaluated separately for each visit, and statistical significance was determined. Results: Urinary retention occurred in 7/46 patients (15%). Of these, 5 were able to void spontaneously after catheter removal. One patient is maintained with a suprapubic tube, and one patient is currently on continuous intermittent catheterization. Baseline IPSS was 7.1 and this went to 20.0 at the first postoperative visit (p<0.001). By the second postoperative visit, the IPSS was 8.0. Conclusions: In our experience, prostate brachytherapy for localized carcinoma of the prostate is associated with a 15% catheterization rate and a significant increase in the IPSS (7.1 to 20.0). This increase in the IPSS seems to be self-limited. Patients need to be educated on these issues prior to prostate brachytherapy. PMID:11113369

  8. Verification of ophthalmic brachytherapy treatment planning

    International Nuclear Information System (INIS)

    Ophthalmic brachytherapy dose calculations were performed as an independent verification of commercial dosimetry software (BEBIG Plaque Simulator). Excel spreadsheets were constructed to follow the formalism of the AAPM Task Group No. 43. As a software commissioning tool, TG43 seed-based coordinates were reformatted to be compatible with plaque-based BEBIG dose tables for centrally positioned seeds. Plaque central axis doses were also calculated for rings of seeds. Close agreement with BEBIG doses was obtained in both cases. Tailored spreadsheet versions were subsequently created to verify patient treatment plans. Treatment time and dose to a specified central-axis point are calculated for ROPES plaques fully loaded with I-125 model 6702 seeds. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  9. A Comparison of Spatio-Temporal Bayesian Models for Reconstruction of Rainfall Fields in a Cloud Seeding Experiment

    Directory of Open Access Journals (Sweden)

    Sujit k. sahu

    2005-01-01

    Full Text Available In response to the drought experienced in Southern Italy a rain seeding project has been setup and developed during the years 1989-1994. The initiative was taken with the purpose of applying existing methods of rain enhancement technology to regions of south Italy including Puglia. The aim of this study is to provide statistical support for the evaluation of the experimental part of the project. In particular our aim is to reconstruct rainfall fields by combining two data sources: rainfall intensity as measured by ground raingauges and radar reflectivity. A difficulty in modeling the rainfall data here comes from rounding of many recorded rainguages. The rounding of the rainfall measurements make the data essentially discrete and models based on continuous distributions are not suitable for modeling these discrete data. In this study we extend two recently developed spatio-temporal models for continuous data to accommodate rounded rainfall measurements taking discrete values with positive probabilities. We use MCMC methods to implement the models and obtain forecasts in space and time together with their standard errors. We compare the two models using predictive Bayesian methods. The benefits of our modeling extensions are seen in accurate predictions of dry periods with no positive prediction standard errors.

  10. Severe rectal complications after prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Some investigators have reported severe rectal complications after brachytherapy. Due to the low number of such events, their relationship to dosimetric parameters has not been well characterized. Methods and materials: A total of 3126 patients were treated with low dose rate brachytherapy from 1998 through 2010. 2464 had implant alone, and 313 had implant preceded by 44–46 Gy supplemental external beam radiation (EBRT). Post-implant dosimetry was based on a CT scan obtained on the day of implant, generally within 30 min of the procedure. Every patient’s record was reviewed for occurrence of rectal complications. Results: Eight of 2464 patients (0.32%) treated with brachytherapy alone developed a radiation-related rectal fistula. Average prostatic and rectal dose parameters were moderately higher for fistula patients than for patients without a severe rectal complication. For instance, the average R100 was 1.2 ± 0.75 cc for fistula patients, versus 0.37 ± 0.88 cc for non-fistula patients. However, the fistula patients’ values were well within the range of values for patients without a rectal complication. Four patients had some attempt at repair or reconstruction, but long-term functional outcomes were not favorable. Conclusions: Rectal fistulas are a very uncommon potential complication of prostate brachytherapy, which can occur even in the setting of acceptable day 0 rectal doses. Their occurrence is not easily explained by standard dosimetric or clinical factors

  11. American Brachytherapy Society (ABS) recommendations for transperineal permanent brachytherapy of prostate cancer

    International Nuclear Information System (INIS)

    Purpose/Objective: To develop and disseminate the American Brachytherapy Society (ABS) recommendations for the clinical quality assurance and guidelines of permanent transperineal prostate brachytherapy with 125I or 103Pd. Methods and Materials: The ABS formed a committee of experts in prostate brachytherapy to develop consensus guidelines through a critical analysis of published data supplemented by their clinical experience. The recommendations of the panels were reviewed and approved by the Board of Directors of the ABS. Results: Patients with high probability of organ-confined disease are appropriately treated with brachytherapy alone. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy (EBRT). Patient selection guidelines were developed. Dosimetric planning of the implant should be carried out for all patients before seed insertion. A modified peripheral loading is preferred. The AAPM TG-43 recommendations requiring a change in prescription dose for 125I sources should be universally implemented. The recommended prescription doses for monotherapy are 145 Gy for 125I and 115-120 Gy for 103Pd. The corresponding boost doses (after 40-50 Gy EBRT) are 100-110 Gy and 80-90 Gy, respectively. Clinical evidence to guide selection of radionuclide (103Pd or 125I) is lacking. Post implant dosimetry and evaluation must be performed on all patients. It is suggested that the dose that covers 90% (D90) and 100% (D100) of the prostate volume and the percentage of the prostate volume receiving the prescribed dose (V100) be obtained from a dose-volume histogram (DVH) and reported. Conclusion: Guidelines for appropriate patient selection, dose reporting, and improved quality of permanent prostate brachytherapy are presented. These broad recommendations are intended to be technical and advisory in nature, but the ultimate responsibility for the medical decisions rests with the treating

  12. Interstitial brachytherapy dosimetry update

    International Nuclear Information System (INIS)

    In March 2004, the American Association of Physicists in Medicine (AAPM) published an update to the AAPM Task Group No. 43 Report (TG-43) which was initially published in 1995. This update was pursued primarily due to the marked increase in permanent implantation of low-energy photon-emitting brachytherapy sources in the United States over the past decade, and clinical rationale for the need of accurate dosimetry in the implementation of interstitial brachytherapy. Additionally, there were substantial improvements in the brachytherapy dosimetry formalism, accuracy of related parameters and methods for determining these parameters. With salient background, these improvements are discussed in the context of radiation dosimetry. As an example, the impact of this update on the administered dose is assessed for the model 200 103Pd brachytherapy source. (authors)

  13. Brachytherapy optimal planning with application to intravascular radiation therapy

    DEFF Research Database (Denmark)

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

    1999-01-01

    We have been studying brachytherapy planning with the objective of manimizing the maximum deviation of the delivered dose from prescribed dose bounds for treatment volumes. A general framework for optimal treatment planning is presented and the minmax optimization is formulated as a linear program....... 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...

  14. Role of TPS in 125I brachytherapy for orbital tumors

    International Nuclear Information System (INIS)

    Objective: To investigate the role of TPS in 125I brachytherapy for orbital tumors. Methods: Sixty-six patients with orbital tumor treated with 125I seeds from 2005 to 2009 were retrospectively analyzed. Forty-three patients were treated using TPS guided brachytherapy and the prescribed dose was 140 Gy. Other 23 patients were treated without TPS but simply implanted with 125I seeds at 1 cm intervals in parallel with each other intraoperatively. CT and TPS quality verification were performed postoperatively in all patients. Also, CT and (or) MRI examination were performed at 3, 6, 12 and 24 months after brachytherapy for follow-up. χ2 test and Kaplan-Meier survival analysis with log-rank significance test were used with SPSS 17.0. Results: A total of 1070 125I seeds were implanted in 66 cases, on average, (16.2 ± 7.3) seeds for each patient. The satisfaction rates of postoperative quality verification in patients with and without TPS pre-plans were 79.07% (34/43) and 43.48% (10/23) respectively (χ2=8.542, P=0.003). Ten patients were lost in follow-up. Local recurrence rates in patients with favorable postoperative quality verification were 0 (0/37) in 3 months, 6.25% (2/32) in 6 months, 13.64% (3/22) in 12 months and 3/9 in 24 months respectively, which were significantly different from those (5.26% (1/19), 16.67% (3/18), 30.77% (4/13), 6/6) in the patients with inferior postoperative quality verification (χ2=9.017, P=0.0003). Conclusions: TPS plays an important role in 125I brachytherapy for orbital tumors. Also, postoperative quality verification by TPS may help predict the local recurrence after brachytherapy. (authors)

  15. Novel prostate brachytherapy technique: Improved dosimetric and clinical outcome

    International Nuclear Information System (INIS)

    Purpose: Erectile dysfunction following prostate brachytherapy is reported to be related to dose received by the penile bulb. To minimise this, whilst preserving prostate dosimetry, we have developed a technique for I-125 seed brachytherapy using both stranded seeds and loose seeds delivered with a Mick applicator, and implanted via the sagittal plane on trans-rectal ultrasound. Materials and methods: Post-implant dosimetry and potency rates were compared in 120 potent patients. In Group 1, 60 patients were treated using a conventional technique of seeds implanted in a modified-uniform distribution. From January 2005, a novel technique was developed using stranded seeds peripherally and centrally distributed loose seeds implanted via a Mick applicator (Group 2). The latter technique allows greater flexibility when implanting the seeds at the apex. Each patient was prescribed a minimum peripheral dose of 145 Gy. No patients received external beam radiotherapy or hormone treatment. There was no significant difference in age or pre-implant potency score (mean IIEF-5 score 22.4 vs. 22.6, p = 0.074) between the two groups. Results: The new technique delivers lower penile bulb doses (D25 as %mPD - Group 1: 61.2 ± 35.7, Group 2: 29.7 ± 16.0, p 50 as %mPD - Group 1: 45.8 ± 26.9, Group 2: 21.4 ± 11.7, p 90 - Group 1: 147 Gy ± 21.1, Group 2: 155 Gy ± 16.7, p = 0.03). At 2 years, the potency rate was also improved: Group 1: 61.7%; Group 2: 83.3% (p = 0.008). Conclusions: In this study, the novel brachytherapy technique using both peripheral stranded seeds and central loose seeds delivered via a Mick applicator results in a lower penile bulb dose whilst improving prostate dosimetry, and may achieve higher potency rates

  16. Navigation system for interstitial brachytherapy

    International Nuclear Information System (INIS)

    The purpose of the stud was to develop a computed tomography (CT) based electromagnetic navigation system for interstitial brachytherapy. This is especially designed for situations when needles have to be positioned adjacent to or within critical anatomical structures. In such instances interactive 3D visualisation of the needle positions is essential. The material consisted of a Polhemus electromagnetic 3D digitizer, a Pentium 200 MHz laptop and a voice recognition for continuous speech. In addition, we developed an external reference system constructed of Perspex which could be positioned above the tumour region and attached to the patient using a non-invasive fixation method. A specially designed needle holder and patient bed were also developed. Measurements were made on a series of phantoms in order to study the efficacy and accuracy of the navigation system. The mean navigation accuracy of positioning the 20.0 cm length metallic needles within the phantoms was in the range 2.0-4.1 mm with a maximum of 5.4 mm. This is an improvement on the accuracy of a CT-guided technique which was in the range 6.1-11.3 mm with a maximum of 19.4 mm. The mean reconstruction accuracy of the implant geometry was 3.2 mm within a non-ferromagnetic environment. We found that although the needles were metallic this did not have a significant influence. We also found for our experimental setups that the CT table and operation table non-ferromagnetic parts had no significant influence on the navigation accuracy. This navigation system will be a very useful clinical tool for interstitial brachytherapy applications, particularly when critical structures have to be avoided. It also should provide a significant improvement on our existing technique

  17. Restenosis: Intracoronary Brachytherapy.

    Science.gov (United States)

    Drachman, Douglas E.; Simon, Daniel I.

    2002-04-01

    Though interventional strategies have revolutionized the management of patients with symptomatic coronary artery disease, in-stent restenosis has emerged as the single most important limitation of long-term success following percutaneous coronary intervention. Once present, in-stent restenosis is extraordinarily difficult to treat, with conventional revascularization techniques failing in 50% to 80% of patients. Intracoronary radiation, or brachytherapy, targets cellular proliferation within the culprit neointima. Clinical trials have demonstrated that brachytherapy is a highly effective treatment for in-stent restenosis, reducing angiographic restenosis by 50% to 60% and the need for target vessel revascularization by 40% to 50%. The benefits of intracoronary brachytherapy may be particularly pronounced in certain patient subgroups (eg, those with diabetes, long lesions, or lesions in saphenous vein bypass grafts), but comes at the cost of an increased rate of late stent thrombosis and the need for extended antiplatelet therapy. The role of brachytherapy in the arsenal of the interventional cardiologist will continue to evolve, particularly in light of the unprecedented recent advances with the use of drug-eluting stents for restenosis prevention. PMID:11858773

  18. Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

    DEFF Research Database (Denmark)

    Hellebust, Taran Paulsen; Tanderup, Kari; Bergstrand, Eva Stabell; Knutsen, Bjørn Helge; Røislien, Jo; Olsen, Dag Rune

    2007-01-01

    The purpose of this study is to investigate whether the method of applicator reconstruction and/or the applicator orientation influence the dose calculation to points around the applicator for brachytherapy of cervical cancer with CT-based treatment planning. A phantom, containing a fixed ring...... reconstruction the uncertainties for all methods are low compared to other factors influencing the accuracy of brachytherapy. Udgivelsesdato: 2007-Aug-21...

  19. 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

  20. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    International Nuclear Information System (INIS)

    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 cm3 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 reduction

  1. Which modality for prostate brachytherapy; Quelle modalite de curietherapie prostatique?

    Energy Technology Data Exchange (ETDEWEB)

    Bossi, A. [Departement de radiotherapie, institut Gustave-Roussy, 94 - Villejuif (France)

    2010-10-15

    Brachytherapy techniques by permanent implant of radioactive sources or by temporary high-dose-rate (HDR) fractions are nowadays extensively used for the treatment of prostatic carcinoma. Long-term results (at 20 years) concerning large amount of patients have been published by major centers confirming both in terms of efficacy and toxicities that permanent implant of radioactive iodine-125 seeds yields at least the same good results of surgery and of external beam irradiation when proposed to patients affected by low-risk disease. For intermediate to high-risk tumors, HDR temporary implants are proposed as a boost for dose escalation. For both techniques, several topics still need to be clarified dealing with a recent enlargement of indications (HDR alone for low-risk, iodine-125 seeds boost for intermediate-high-risk cancers), or with technical aspects (loose seeds versus linked ones, number of fractions and dose for HDR protocols), while dosimetric issues have only recently been addressed by cooperatives groups. Last but not least, there is a real need to address and clearly characterize the correct definition of biochemical disease control both for iodine permanent implant and for HDR implant. New challenges are facing the prostate-brachytherapy community in the near future: local relapse after external beam radiotherapy are currently managed by several salvage treatments (prostatectomy, cryo, high intensity focused ultrasounds [HIFU]) but the role of reirradiation by brachytherapy is also actively investigated. Focal therapy has gained considerable interest in the last 5 years aiming at treating only the area of cancer foci inside the prostate and preserving nearby healthy tissues. Encouraging results have been obtained with the so-called 'minimally invasive' approaches and both permanent seed implantation and HDR brachytherapy techniques may be worthwhile testing in this setting because of their capability of exactly sculpting the dose inside the

  2. The use of nomograms in LDR-HDR prostate brachytherapy

    OpenAIRE

    Pujades, Ma Carmen; Camacho, Cristina; Perez-Calatayud, Jose; Richart, José; Gimeno, Jose; Lliso, Françoise; Carmona, Vicente; Ballester, Facundo; Crispín, Vicente; Rodríguez, Silvia; Tormo, Alejandro

    2011-01-01

    Purpose The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different...

  3. Penile brachytherapy: Results for 49 patients

    International Nuclear Information System (INIS)

    Purpose: To report results for 49 men with squamous cell carcinoma (SCC) of the penis treated with primary penile interstitial brachytherapy at one of two institutions: the Ottawa Regional Cancer Center, Ottawa, and the Princess Margaret Hospital, Toronto, Ontario, Canada. Methods and Materials: From September 1989 to September 2003, 49 men (mean age, 58 years; range, 22-93 years) had brachytherapy for penile SCC. Fifty-one percent of tumors were T1, 33% T2, and 8% T3; 4% were in situ and 4% Tx. Grade was well differentiated in 31%, moderate in 45%, and poor in 2%; grade was unspecified for 20%. One tumor was verrucous. All tumors in Toronto had pulsed dose rate (PDR) brachytherapy (n = 23), whereas those in Ottawa had either Iridium wire (n 22) or seeds (n = 4). Four patients had a single plane implant with a plastic tube technique, and all others had a volume implant with predrilled acrylic templates and two or three parallel planes of needles (median, six needles). Mean needle spacing was 13.5 mm (range, 10-18 mm), mean dose rate was 65 cGy/h (range, 33-160 cGy/h), and mean duration was 98.8 h (range, 36-188 h). Dose rates for PDR brachytherapy were 50-61.2 cGy/h, with no correction in total dose, which was 60 Gy in all cases. Results: Median follow-up was 33.4 months (range, 4-140 months). At 5 years, actuarial overall survival was 78.3% and cause-specific survival 90.0%. Four men died of penile cancer, and 6 died of other causes with no evidence of recurrence. The cumulative incidence rate for never having experienced any type of failure at 5 years was 64.4% and for local failure was 85.3%. All 5 patients with local failure were successfully salvaged by surgery; 2 other men required penectomy for necrosis. The soft tissue necrosis rate was 16% and the urethral stenosis rate 12%. Of 8 men with regional failure, 5 were salvaged by lymph node dissection with or without external radiation. All 4 men with distant failure died of disease. Of 49 men, 42 had an intact

  4. Glass microspheres for brachytherapy

    International Nuclear Information System (INIS)

    We developed the capacity to produce glass microspheres containing in their structure one or more radioactive isotopes useful for brachytherapy. We studied the various facts related with their production: (Rare earth) alumino silicate glass making, glass characterization, microspheres production, nuclear activation through (n,γ) nuclear reactions, mechanical characterization before and after irradiation. Corrosion tests in simulated human plasma and mechanical properties characterization were done before and after irradiation. (author)

  5. 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.

  6. β-Ray brachytherapy with 106Ru plaques for retinoblastoma

    International Nuclear Information System (INIS)

    Purpose: A retrospective analysis of 134 patients who received 106Ru brachytherapy for retinoblastomas (175 tumors in 140 eyes). Treatment and follow-up were analyzed with special emphasis on tumor control organ, preservation, and late complications. Results: Treated tumors had a mean height and diameter of 3.7 ± 1.4 mm and 5.0 ± 2.8 disk diameters, respectively. The radiation dose values were recalculated according to the calibration standard recently introduced by the National Institute of Standards and Technology. The recalculation revealed a mean applied dose of 419 Gy at the sclera (SD, 207 Gy) and 138 Gy (SD, 67 Gy) at the tumor apex. The 5-year tumor control rate was 94.4%. Tumor recurrence was more frequent in eyes with vitreous tumor cell seeding or fish-flesh regression. The estimated 5-year eye preservation rate was 86.5%. Previous treatment by brachytherapy or external beam radiotherapy, as well as a large tumor diameter, were significant factors for enucleation. The radiotherapy-induced complications after 5 years of follow-up were retinopathy (22%), optic neuropathy (21%), and cataract (17%). These complications were significantly more frequent after prior brachytherapy or external beam radiotherapy. Conclusion: Brachytherapy using 106Ru plaques is a highly efficient therapy with excellent local tumor control and an acceptable incidence of side effects

  7. Survey of isodose curves of Iodine-125 seeds using photographic films

    International Nuclear Information System (INIS)

    Brachytherapy is a form of radiotherapy where a radioactive source is placed in contact with the tissue to be treated. In interstitial brachytherapy, small radioactive sealed sources are used, which are called seeds. The development prototypes. In the case of new brachytherapy seeds during the early stages of their development is introduced. CDNT has partially developed a prototype for brachytherapy treatment consisting of a porous ceramic matrix capable of incorporating different radionuclides. The next step of developing a new type of seed is its dosimetric characterization, which must be performed in accordance with certain international standards. A practical methodology that uses photographic film was developed in a prior master's work accomplished at CDTN to characterize partially brachytherapy seeds and evaluate possible problems that can occur in the early stages of new seeds development, such as low incorporation rate, which translates in a low dose deposition or a inhomogeneous incorporation, resulting in a space radiation field deformation (anisotropy). This method has now been improved and use in obtaining the iodine-125 seed's curves, in the film calibration curve obtainment and dose values estimates as different seeds spatial distributions. In this work, it was used as reference, a commercial seed of iodine-125. The method was sensitive and can be used for seeds with low activity. The use of photographic film allows the visualization of radioactive material incorporation problems, if any, which can occur even in commercial seeds. Therefore, the method shows to be useful for a quick check of seeds before they are used in patients. (author)

  8. Salvage Brachytherapy for Biochemically Recurrent Prostate Cancer following Primary Brachytherapy

    Science.gov (United States)

    Lacy, John M.; Wilson, William A.; Bole, Raevti; Chen, Li; Meigooni, Ali S.; Rowland, Randall G.; Clair, William H. St.

    2016-01-01

    Purpose. In this study, we evaluated our experience with salvage brachytherapy after discovery of biochemical recurrence after a prior brachytherapy procedure. Methods and Materials. From 2001 through 2012 twenty-one patients treated by brachytherapy within University of Kentucky or from outside centers developed biochemical failure and had no evidence of metastases. Computed tomography (CT) scans were evaluated; patients who had an underseeded portion of their prostate were considered for reimplantation. Results. The majority of the patients in this study (61.9%) were low risk and median presalvage PSA was 3.49 (range 17.41–1.68). Mean follow-up was 61 months. At last follow-up after reseeding, 11/21 (52.4%) were free of biochemical recurrence. There was a trend towards decreased freedom from biochemical recurrence in low risk patients (p = 0.12). International Prostate Symptom Scores (IPSS) increased at 3-month follow-up visits but decreased and were equivalent to baseline scores at 18 months. Conclusions. Salvage brachytherapy after primary brachytherapy is possible; however, in our experience the side-effect profile after the second brachytherapy procedure was higher than after the first brachytherapy procedure. In this cohort of patients we demonstrate that approximately 50% oncologic control, low risk patients appear to have better outcomes than others. PMID:27092279

  9. Feasibility of salvage interstitial microwave thermal therapy for prostate carcinoma following failed brachytherapy: studies in a tissue equivalent phantom

    International Nuclear Information System (INIS)

    Thermal therapy is an experimental treatment to destroy solid tumours by heating them to temperatures ranging from 55 deg C to 90 deg C, inducing thermal coagulation and necrosis of the tumour. We are investigating the feasibility of interstitial microwave thermal therapy as a salvage treatment for prostate cancer patients with local recurrence following failed brachytherapy. Due to the electrical and thermal conductivity of the brachytherapy seeds, we hypothesized that the seeds could scatter the microwave energy and cause unpredictable heating. To investigate this, a 915 MHz helical antenna was inserted into a muscle-equivalent phantom with and without brachytherapy seeds. Following a 10 W, 5 s input to the antenna, the temperature rise was used to calculate absorbed power, also referred to as specific absorption rate (SAR). Plane wave models based on Maxwell's equations were also used to characterize the electromagnetic scattering effect of the seeds. In addition, the phantom was heated with 8 W for 5 min to quantify the effect of the seeds on the temperature distribution during extended heating. SAR measurements indicated that the seeds had no significant effect on the shape and size of the SAR pattern of the antenna. However, the plane wave simulations indicated that the seeds could scatter the microwave energy resulting in hot spots at the seed edges. Lack of experimental evidence of these hot spots was probably due to the complex polarization of the microwaves emitted by the helical antenna. Extended heating experiments also demonstrated that the seeds had no significant effect on the temperature distributions and rates of temperature rise measured in the phantom. The results indicate that brachytherapy seeds are not a technical impediment to interstitial microwave thermal therapy as a salvage treatment following failed brachytherapy

  10. A study of brachytherapy for intraocular tumor

    International Nuclear Information System (INIS)

    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)

  11. HDR endobronchial brachytherapy

    International Nuclear Information System (INIS)

    Introduction: This is a restrospective study to review the palliation rate, survival rate and complications of high dose rate (HDR) endobronchial brachytherapy in the treatment of airway obstruction of recurrent lung cancer or metastasis. Material and method: Between september 1992 and may 1995 it has been treated forty (40) patients with endobronchial lesions. 38 patients with unique endobronchial lesion and 2 patients with double lesions. 32 had primary lung carcinoma: 27 with epidermoid carcinoma (1 bilateral), 2 with adenocarcinoma, 1 with small cell carcinoma, 1 with undifferentiated carcinoma and 1 with primary double (adenocarcinoma and large cell carcinoma). 8 patients had endobronchial metastasis: 2 hypernefroma, 3 breast carcinoma, 1 colon cancer, 1 seminoma and 1 Ewing sarcoma. 33 patients were male (82.5%) and 7 female (17.5%). The treatment was carried out in three weekly fractions with a dose of 750 cGy per fraction at 1 cm from the source. An afterloaded equipment was used (microselectron HDR). The most frequent sites were: right main stem bronchus 9 patients (22.5%), left main stem bronchus 7 patients (17.5%), and right middle bronchus 5 patients (12.5%). Results and discussion: The endoscopic global response assessed after three weeks was of 70%. The symptomatic response was 95% hemoptysis control, 87% dysnea control, 80% obstructive pneumonia control and 70% cough control. The minimum follow up was one year. There were three cases of massive hemoptysis and three patients developed local recurrence (one received a second brachytherapy treatment). Conclusion: HDR brachytherapy offers an excellent long term palliation for any of the obstructing symptoms, being effective in more than 70% in patients with recurrence lung primary cancer or endobronchial metastasis with a low complication rate

  12. Intra coronary brachytherapy

    International Nuclear Information System (INIS)

    Despite the initial promise of vasculopathy intervention restenosis- a consequence of the (normal) would healing process-has emerged as a major problem. Angiographic restenosis has been reported in 40-60% of patients after successful P TCA. The basic mechanism of restenosis, (acute recoil, negative remodeling and neo intimal hyperplasia), are only partially counteracted by endovascular prosthetic devices (s tents). The rate of in-s tent restenosis, which is primarily caused by neo intimal hyperplasia due to the (micro) trauma of the arterial wall by the s tent struts, has been reduced to 18-32%. Ionizing (beta or gamma) radiations has been established as a potent treatment for malignant disorders. In recent years, there has also been increasing interest among clinicians in the management of benign lesions with radiation. Over the past several years, there has been a growing body of evidence that endovascular brachytherapy has a major impact on the biology of the restenosis. It must be underlined that understanding the biology and pathophysiology of restenosis and assessing various treatment options should preferably be a team effort, with the three gracesbeing interventional cardiologist, nuclear oncologist, and industrial partners. The vast amount of data in over 20000 patients from a wide range of randomized controlled trials, has shown that brachytherapy is the only effective treatment for in-s tent restenosis. We are learning more and more about how to improve brachytherapy. While the new coated s tents that we heard about today is fascinating and extremely promising, brachytherapy still has a very important place in difficult patients, such as those with total occlusions, osti al lesions, left main lesions, multivessel disease and diabetes. Regarding to above mentioned tips, we (a research team work, in the Nuclear Research Center Of the Atomic Energy Organization Of Iran), focused on synthesis and preparation of radioactive materials for use in I c-B T. We

  13. MRI/TRUS data fusion for brachytherapy

    CERN Document Server

    Daanen, V; Giraud, J Y; Fourneret, P; Descotes, J L; Bolla, M; Collomb, D; Troccaz, Jocelyne

    2006-01-01

    BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for tumour destruction under transrectal ultrasound imaging (TRUS) control. It requires prostate delineation from the images for dose planning. Because ultrasound imaging is patient- and operator-dependent, we have proposed to fuse MRI data to TRUS data to make image processing more reliable. The technical accuracy of this approach has already been evaluated. METHODS: We present work in progress concerning the evaluation of the approach from the dosimetry viewpoint. The objective is to determine what impact this system may have on the treatment of the patient. Dose planning is performed from initial TRUS prostate contours and evaluated on contours modified by data fusion. RESULTS: For the eight patients included, we demonstrate that TRUS prostate volume is most often underestimated and that dose is overestimated in a correlated way. However, dose constraints are still verified for those eight patients. CONCLUSIONS: This confirms our init...

  14. A simple technique for the generation of institution-specific nomograms for permanent prostate cancer brachytherapy

    OpenAIRE

    Lafata, Kyle J.; Bushe, Harry; Aronowitz, Jesse N.

    2014-01-01

    Purpose Nomograms once had a vital role in prostate brachytherapy practice. Although some of their functions have been assumed by computerized dosimetry, many programs still find them useful to determine the number and strength of seeds to be ordered in advance of the implant. As it has been demonstrated that brachytherapists differ in their implant practices and preferences (in regard to seed distribution and total implanted activity), we propose a simple technique for generating institution...

  15. The Effects of Metallic Implants on Electroporation Therapies: Feasibility of Irreversible Electroporation for Brachytherapy Salvage

    International Nuclear Information System (INIS)

    Purpose: Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments. Materials and Methods: This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions. Results: There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins. Conclusion: This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy

  16. The Effects of Metallic Implants on Electroporation Therapies: Feasibility of Irreversible Electroporation for Brachytherapy Salvage

    Energy Technology Data Exchange (ETDEWEB)

    Neal, Robert E., E-mail: robert.neal@alfred.org.au [The Alfred Hospital, Radiology Research Unit, Department of Radiology (Australia); Smith, Ryan L., E-mail: ryan.smith@wbrc.org.au [The Alfred Hospital, William Buckland Radiotherapy Centre (Australia); Kavnoudias, Helen, E-mail: H.Kavnoudias@alfred.org.au [The Alfred Hospital, Radiology Research Unit, Department of Radiology (Australia); Rosenfeldt, Franklin, E-mail: F.Rosenfeldt@alfred.org.au; Ou, Ruchong, E-mail: Ruchong.Ou@bakeridi.edu.au [Monash University, Department of Surgery (Australia); Mclean, Catriona A., E-mail: C.Mclean@alfred.org.au [The Alfred Hospital, Department of Anatomical Pathology (Australia); Davalos, Rafael V., E-mail: davalos@vt.edu [Virginia Tech, School of Biomedical Engineering and Sciences (United States); Thomson, Kenneth R., E-mail: K.Thomson@alfred.org.au [The Alfred Hospital, Radiology Research Unit, Department of Radiology (Australia)

    2013-12-15

    Purpose: Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments. Materials and Methods: This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions. Results: There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins. Conclusion: This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

  17. Iodine-125 brachytherapy for brain tumours - a review

    International Nuclear Information System (INIS)

    Iodine-125 brachytherapy has been applied to brain tumours since 1979. Even though the physical and biological characteristics make these implants particularly attractive for minimal invasive treatment, the place for stereotactic brachytherapy is still poorly defined. An extensive review of the literature has been performed, especially concerning indications, results and complications. Iodine-125 seeds have been implanted in astrocytomas I-III, glioblastomas, metastases and several other tumour entities. Outcome data given in the literature are summarized. Complications are rare in carefully selected patients. All in all, for highly selected patients with newly diagnosed or recurrent primary or metastatic tumours, this method provides encouraging survival rates with relatively low complication rates and a good quality of life

  18. Brachytherapy- past, present and future

    International Nuclear Information System (INIS)

    Discovery of radioactivity by Henry Becquerel and radium by Madame and Pierre Curie was probably the greatest event of 19th century in the field of medical science. Radium was used for brachytherapy as early as 1901. Today almost every organ is amenable to brachytherapy procedure. High dose rate remote afterloading systems have increased the patients comfort and complete radiation protection to the staff during treatment. Computers have not only improved the precision of treatment but also made 3 D conformal brachytherapy possible. As the goal of cancer management is changing from just life preservation to organ and function preservation without compromising cure rate, the role of brachytherapy is becoming more and more prominent. Intensive efforts will be needed to meet with the future challenges. (author). 13 refs

  19. A Monte Carlo investigation of lung brachytherapy treatment planning

    International Nuclear Information System (INIS)

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

  20. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    Science.gov (United States)

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

  1. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    International Nuclear Information System (INIS)

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10−6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. (paper)

  2. New Brachytherapy Standards Paradigm Shift

    International Nuclear Information System (INIS)

    The absorbed dose to water rate at short distances in water is the quantity of interest for dosimetry in radiotherapy, but no absorbed dose to water primary standards have been available to date for dosimetry of brachytherapy sources. Currently, the procedures to determine the absorbed dose imparted to the patient in brachytherapy treatments are based on measurements traceable to air kerma standards. These procedures are affected by an uncertainty that is larger than the limit recommended by the IAEA dosimetry protocol (IAEA TRS 398 (2000)). Based on this protocol, the goal for the uncertainty of the dose delivered to the target volume should be within 5% (at the level of one standard deviation) to assure the effectiveness of a radiotherapy treatment. The international protocols for the calibration of brachytherapy gamma ray sources are based on the reference air kerma rate or the air kerma strength. The absorbed dose to water, in water at the reference position around a brachytherapy source is then calculated by applying the formalism of the protocols based on a conversion constant, the dose rate constant Λ, specific for the characteristics and geometry of the brachytherapy source. The determination of this constant relies on Monte Carlo simulations and relative measurements performed with passive dosimeters, and therefore it is typically affected by large uncertainties, larger than 5% (at the level of one standard deviation). The conversion procedure needed for brachytherapy dosimetry is a source of additional uncertainty on the final value of the absorbed dose imparted to the patient. It is due to a lack of metrology standards that makes dosimetry of brachytherapy sources less accurate than dosimetry of external radiation beams produced by 60Co sources and accelerators currently used in external beam radiotherapy. This paper reviews the current developments of absorbed dose to water primary standards for brachytherapy and the rationale for the choice of the

  3. Brachytherapy in childhood rhabdomyosarcoma treatment

    International Nuclear Information System (INIS)

    A retrospective study of 21 children with rhabdomyosarcoma treated by brachytherapy to the primary site of the tumor at the Radiotherapy Department of the A.C.Camargo Hospital between january/1980 to june/1993 was undertaken. The main objectives were to comprove the utility of brachytherapy in childhood rhabdomyosarcoma, to evaluate the local control and survival, in association with chemotherapy, to analyze the late effects of the treatment and to determinate the preferential technique to each clinical situation. All patients received brachytherapy to the tumor site. The radioactive isotopes employed were Gold198, Cesium137 and Iridium192. The brachytherapy techniques depended on the tumor site, period of treatment, availability of the radioactive material and stage of the disease. Patients treated exclusively by brachytherapy received 40 Gy to 60 Gy. When brachytherapy was associated with external radiotherapy the dose ranged from 20 Gy to 40 Gy. Local control was achieved in 18 of 20 patients (90%). The global survival and local control survival rates were 61.9% (13/21 patients) and 72,2% (13/18 patients) respectively. (author)

  4. Inverse planning in brachytherapy from radium to high rate 192 iridium afterloading

    International Nuclear Information System (INIS)

    We consider the inverse planning problem in brachytherapy, i.e. the problem to determine an optimal number of catheters, number of sources for low-dose rate brachytherapy (LDR) and the optimal dwell times for high-dose rate brachytherapy (HDR) necessary to obtain an optimal as possible dose distribution. Starting from the 1930s, inverse planning for LDR brachytherapy used geometrically derived rules to determine the optimal placement of sources in order to achieve a uniform dose distribution of a specific level in planes, spheres and cylinders. Rules and nomograms were derived which still are widely used. With the rapid development of 3D imaging technologies and the rapidly increasing computer power we have now entered the new era of computer-based inverse planning in brachytherapy. The inverse planning is now an optimisation process adapted to the individual geometry of the patient. New inverse planning optimisation algorithms are anatomy-based that consider the real anatomy of the tumour and the organs at risk (OAR). Computer-based inverse planning considers various effects such as stability of solutions for seed misplacements which cannot ever be solved analytically without gross simplifications. In the last few years multiobjective (MO) inverse planning algorithms have been developed which recognise the MO optimisation problem which is inherent in inverse planning in brachytherapy. Previous methods used a trial and error method to obtain a satisfactory solution. MO optimisation replaces this trial and error process by presenting a representative set of dose distributions that can be obtained. With MO optimisation it is possible to obtain information that can be used to obtain the optimum number of catheters, their position and the optimum distribution of dwell times for HDR brachytherapy. For LDR brachytherapy also the stability of solutions due to seed migration can also be improved. A spectrum of alternative solutions is available and the treatment planner

  5. Acute urinary toxicity following transperineal prostate brachytherapy using a modified Quimby loading method

    International Nuclear Information System (INIS)

    Purpose: To examine the acute urinary toxicity following transperineal prostate implant using a modified Quimby loading method with regard to time course, severity, and factors that may be associated with a higher incidence of morbidity. Methods and Materials: One hundred thirty-nine patients with prostate adenocarcinoma treated with brachytherapy from 1997 through 1999 had follow-up records available for review. Patients considered for definitive brachytherapy alone included those with prostate specific antigen (PSA) ≤6, Gleason score (GS) ≤6, clinical stage 6, PSA>6, or Stage>T2a were treated with external beam radiation therapy followed by brachytherapy boost. Sources were loaded according to a modified Quimby method. At each follow-up, toxicity was graded based on a modified RTOG urinary toxicity scale. Results: Acute urinary toxicity occurred in 88%. Grade I toxicity was reported in 23%, grade II in 45%, and grade III in 20%, with 14% requiring prolonged (greater than 1 week) intermittent or indwelling catheterization. Overall median duration of symptoms was 12 months. There was no difference in duration of symptoms between patients treated with I-125 or Pd-103 sources (p=0.71). After adjusting for GS and PSA, multivariate logistic regression analysis showed higher incidence of grade 3 toxicity in patients with larger prostate volumes (p=0.002), and those with more seeds implanted (p<0.001). Higher incidence of prolonged catheterization was found in patients receiving brachytherapy alone (p=0.01), with larger prostate volumes (p=0.01), and those with more seeds implanted (p<0.001). Conclusion: Interstitial brachytherapy for prostate cancer leads to a high incidence of acute urinary toxicity, most of which is mild to moderate in severity. A prolonged need for catheterization can occur in some patients. Patients receiving brachytherapy alone, those with prostate volumes greater than 30 cc, and those implanted with a greater number of seeds have the highest

  6. Clinical efficacy of CT-guided 125I seed implantation therapy for advanced pancreatic cancer

    International Nuclear Information System (INIS)

    Objective: To discuss the clinical efficacy of CT-guided radioactive 125I seed implantation treatment for unresectable pancreatic cancer. Methods: Forty patients with inoperable pancreatic cancer were enrolled in this study, including 25 males and 15 females with an median age of 69 years (38-89 years). Treatment planning system (TPS) was used to reconstruct 3-dimensional images of pancreatic tumor and to define the quantity and distribution of 125I seeds. The radioactivity of 125I seeds was 0.5 - 0.8 mCi / seed. The seeds were implanted into pancreatic tumor under CT guidance at intervals of 1 cm and were kept away from vessels, pancreatic duct and other adjacent important organs. The tumor matched peripheral dose (MPD) was 60-140 Gy. The median amount of implanted 125I seeds was 36 (18-68) in number. CT scan was performed immediately after the procedure to check the quality of the seeds. In addition, 10 patients received concurrent chemotherapy with arterial infusion of gemcitabin and 5-fluororacil (5-Fu) for 3 to 4 therapeutic courses. Results: The median diameter of the tumors was 4.9 cm. The follow-up period was 2 to 28 months. After the treatment the refractory pain was significantly relieved (P 125I seed implantation is a safe, effective and minimally-invasive brachytherapy for unresectable pancreatic cancer with reliable short-term efficacy. It has an excellent anti-pain effect. The curative results can be further improved when chemotherapy is employed together. However, its long-term efficacy needs to be observed. (authors)

  7. 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)

  8. Measure of the uncertainty associated with the reconstruction of applicators in adaptive guided brachytherapy by resonance; Medida de la incertidumbre asociada a la reconstruccion de aplicadores en braquiterapia adaptativa guiada por resonancia

    Energy Technology Data Exchange (ETDEWEB)

    Torres Pozas, S.; Federico, M.; Perez Molina, J. L.; Marti Asenjo, J.; Sanchez Carrascal, M.; Macias verde, D.; Ruiz Egea, E.; Lara Jimenez, P.; Martin Oliva, R.

    2013-07-01

    The objective of this study is to assess the uncertainty introduced in the process to rebuild the catheters using three methods, manual reconstruction from a template elaborate service, auto-rebuild with the software included in the TPS and reconstruction from radiopaque mannequins in CT and subsequent merger. (Author)

  9. Medical physics aspects of ophthalmic brachytherapy

    International Nuclear Information System (INIS)

    Intraocular melanoma is the most common primary malignancy of the eye. Radiation therapy using ophthalmic plaque has proved successful in the management of various ocular lesions. Although a few centres were using 90Sr/90Y plaques for shallow turtlours some years ago, eye plaque therapy was not a common practice in India. A revived interest in the use of eye plaque therapy and very high cost of imported sources has led to the development and production of 125I seed sources by the Radiopharmaceuticals Division, BARC. This report presents a brief description on the clinical, dosimetry and radiation safety aspects of 90Sr/90Y and 106Ru/106Rh beta ray and 125I gamma ray eye plaque applicators. This report has been divided in five Sections. Section I presents general introduction of ophthalmic brachytherapy including the structure of a human eye, types of ophthalmic plaques and characteristics of radioisotopes commonly used in such applications. A brief review of sources, applicators and dosimetry of 90Sr/90Y and 106Ru/106Rh beta and 125I gamma ophthalmic plaques are given in Section II and Section III, respectively. Section IV contains the single seed dosimetry data of BARC OcuProsta 125I seed as well as dosimetry data of typical eye plaques loaded with BARC OcuProsta 125I seed. Quality assurance and radiation safety aspects of these eye applicators are described in Section V. A proforma of the application required to be filled in by the user institution for obtaining regulatory consent to start eye plaque therapy has also been appended to this report. (author)

  10. Development of prostate voxel models for brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Adriano M.; Reis, Lucas P.; Grynberg, Suely E., E-mail: amsantos@cdtn.b [Center for Development of Nuclear Technology (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The tools developed recently in the areas of computer graphics and animation movies to computer games allow the creation of new voxel anthropomorphic phantoms with better resolution and thus, more anatomical details. These phantoms can be used in nuclear applications, especially in radiation protection for estimating doses in cases of occupational or accidental radioactive incidents, and in medical and biological applications. For dose estimates, the phantoms are coupled to a Monte Carlo code, which will be responsible for the transport of radiation in this environment. This study aimed to develop a computational tool to estimate the isodose curves in the prostate after brachytherapy seed implants. For this, we have created a model called FANTPROST in the shape of a 48 mm side cube, with a standard prostate inserted in the center of this cube with different distributions of brachytherapy seeds in this volume. The prostate, according to this model, was obtained from the phantom voxels MASH2 developed by Numerical Dosimetry Group, Department of Nuclear Energy - Federal University of Pernambuco. The modeling of the seeds, added to FANTPROST, was done through the use of geometric information of Iodine-125 Amersham 6711 commercial seed. The simulations were performed by the code MCNP5 for spatial distributions containing different amounts of seeds within the FANTPROST. The obtained curves allowed an estimation of the behavior of the maximum dose that decreases with distance, showing that this tool can be used for a more accurate analysis of the effects produced by the presence of such seeds in the prostate and its vicinity. (author)

  11. Implementation of GaN based real-time source position monitoring in HDR brachytherapy

    International Nuclear Information System (INIS)

    For High Dose Rate (HDR) brachytherapy Quality Assurance (QA), we propose a seed position verification method by using two GaN dosimetric probes integrated in an instrumented phantom. As dose rate measured from one probe is related to the seed distance, seed position inside catheter can be determined. The proposed two-probe method extends measureable range and improves accuracy in comparison with the use of one single probe. One instrumented phantom implementing the method was designed, fabricated and tested in clinical conditions. The measureable range of the two-probe method is 105 mm compared to 36 mm using single probe. The validity of the method was experimentally verified. - Highlights: • A simple brachytherapy QA phantom has been instrumented. • Dwell positions have been estimated according to measured dose rate by GaN probes. • Measured dose rate shows 1% average deviation from calculated results. • Determined dwell position precision and measureable range was studied

  12. 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.)

  13. Iodine-125 orbital brachytherapy with a prosthetic implant in situ

    International Nuclear Information System (INIS)

    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.)

  14. Halo's production in vitro on brachytherapy experiments

    International Nuclear Information System (INIS)

    Since earlier of 1960, one of the most significant contributions of radiation biology has been the theory of cell killing as a function of increasing doses of a cytotoxic agent, as well as the demonstration of repair of sublethal or potentially lethal damage after irradiation. The impact of cellular and molecular radiobiology, by exploitation of cellular mechanisms related to apoptosis, may be the cell killing with irradiation by including changes other than unrepaired DNA damage. Based on the understanding of the tumor microenvironment and how growth factors and proteins produced by irradiated cells may alter cellular processes, improved combined-modality strategies may emerge. This effect was show since 1960's, but here we propose to demonstrate this phenomenon in Brachytherapy. The present goal is to verify the macroscopic response through the production and analysis of clonogenic control based on halos generation by radioactive seeds of Ho-165 and Sm-153, aiming to study the effect of this type of irradiation. Confluent cell culture flasks with HeLa cell line were subjected to radiation in a period up to five half-lives of radionuclide, respectively. Devices were introduced which set the polymer-ceramic Ho-165 and Sm-153 seeds in the vials. After a period of exposure, the flasks were stained with violet Gensiana. The results showed the formation of halos control of confluent cancer cells. This paper will describe these experiments in the current stage of the research and report the implications of this new way of therapy for cancer treatment. (author)

  15. 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

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

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

    International Nuclear Information System (INIS)

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  17. Erectile function after prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. Methods and materials: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of ≥13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V100/150/200); the dose delivered to 90% of the prostate gland (D90); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. Results: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal erections

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

    International Nuclear Information System (INIS)

    Purpose: To determine the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters (TLD-100) for 125I and 103Pd brachytherapy sources relative to 60Co. Methods: LiF:Mg,Ti TLDs were irradiated with low-energy brachytherapy sources and with a 60Co teletherapy source. The brachytherapy sources measured were the Best 2301 125I seed, the OncoSeed 6711 125I seed, and the Best 2335 103Pd 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 60Co 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 60Co irradiations. The measured and MC-calculated results for all irradiations were used to determine the TLD intrinsic energy dependence for 125I and 103Pd relative to 60Co. Results: The relative TLD intrinsic energy dependences (relative to 60Co) 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 125I and 103Pd sources relative to 60Co. TLD measurements of absolute dose around 125I and 103Pd brachytherapy sources should explicitly account for the relative TLD intrinsic energy dependence in order to improve dosimetric accuracy

  19. Intracavitary mould brachytherapy in malignant tumors of the maxilla

    International Nuclear Information System (INIS)

    Purpose: To integrate brachytherapy in the combined modality management of malignant tumors of the maxilla, as a means of increasing the radiotherapy dose to the tumor bed while avoiding high doses to the orbital contents. Materials and methods: Following a partial or total maxillectomy, a duplication of the interim surgical obturator was created using a wash of vinyl polysiloxane. This mould was used as a carrier for afterloading nylon catheters through which 192-Iridium seed-ribbons were inserted. Following brachytherapy, selected patients also received external beam irradiation. Results and discussion: After a median follow-up of 36 months, 9 out of 11 patients are alive and disease-free; 1 developed a local recurrence and another relapsed at another site in the oral cavity. Transient grade 1 - 2 mucositis at the implant site was observed in all patients. The review of computer isodose distributions showed that the average dose received by the homolateral eyeball was 10% (range 9,2 - 10.0) of the prescribed surface dose to the surgical cavity. Conclusions: Brachytherapy can be integrated in the management of patients with malignant tumors of the maxilla in the form of a custom-made intracavitary mould carrying 192-Iridium sources. We found this technique particularly useful in cases with close or positive surgical margins

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

    International Nuclear Information System (INIS)

    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 cm3. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm3. 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

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

    Science.gov (United States)

    Fendriani, Yoza; Haryanto, Freddy

    2015-09-01

    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 cm3. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm3. 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.

  2. Criteria for the evaluation of brachytherapy for malignant brain tumors

    International Nuclear Information System (INIS)

    Thirty two patients with recurrent or unresectable malignant brain tumors were treated by interstitial brachytherapy with Ir-192 seeds. After-loading catheters were stereotactically implanted under local anesthesia using a Brown-Roberts-wells (BRW) CT guided stereotactic system. The response to the therapy was followed by serial CT and MRI scans and evaluated three months after implantation by the standard criteria for the evaluation of chemotherapy because there is no set of criteria available for radiation therapy. After interstitial brachytherapy, the most commonly observed CT and MRI finding was central low attenuation, that is, the central enhanced tumor replaced by the radiation necrosis. Three months after the treatment, these findings were observed in 23 patients out of 32 patients on the CT and MRI. We observed complete response (CR) in 6 of 32 patients, partial response (PR) in 9, no change (NC) in 7 and progressive disease (PD) in 9. In 6 CR patients, the tumor disappeared by three months after treatment. In 15 patients of 17 NC and PD patients, the central low attenuation was observed and their prognosis was better than those without central necrosis. The results suggested the standard criteria for the evaluation of chemotherapy, such as CR, PR etc, cannot be applicable to our series because the tumor mass replaced by necrotic tissue and remained as a mass lesion in most cases and new criteria in consideration of this low attenuation on CT and MRI will be needed for the evaluation of brachytherapy on neuroimagings. (author)

  3. The value of MRI three-dimensional reconstruction in diagnosis and therapy of prostate cancer

    International Nuclear Information System (INIS)

    Objective: To evaluate three-dimensional reconstruction of MRI images in diagnosis and therapy of prostate cancer. Methods: Twenty-eight patients with proven prostate cancers were recruited in this study. Seventeen of them were diagnosed as having prostate cancer according to the ultrasound guided systemic biopsy. Their MR examinations showed fourteen lesions in the peripheral zone and three in the central gland of the prostate. The other eleven patients underwent MR examination after a period of treatment, including endocrinetherapy and brachytherapy. Using endorectal coil, a series of T2-weighted images were acquired on the axial plane. These source images were processed by 3D-Doctor software to reconstruct into three-dimensional images. Results: In the fourteen patients with peripheral zone cancer, reconstruction images could display the 3D regions of cancer and the involvement of capsular. The outspread of central gland and the compression of peripheral zone in patients with central gland cancer could be revealed in the same way. The volumetric changes of the lesion and the prostate after endocrinetherapy could also be perceived through these 3 D images. Similarly, radioactive seeds were revealed in a spatial manner that could be easily evaluated. Conclusion: Three-dimensional reconstruction images were obtained in all patients. They were able to provide stereotyped information about the lesions and their surrounding tissues. MRI three-dimensional reconstruction can be an adjunctive tool in the evaluation of prostate lesions. (authors)

  4. The role of long half-life isotopes for use in LDR brachytherapy. Report of the advisory group meeting (325-E3-AG-1086)

    International Nuclear Information System (INIS)

    Brachytherapy is a growing activity in the management of cancer. Where indications exist for brachytherapy, LDR still retains a significant but decreasingly important role in the overall management. It remains the preferred form of brachytherapy in a few sites such as the nose, lip, vagina and penis. It is well tested in the paediatric population where long-term sequelae are highly significant and have not yet been evaluated for mHDR. Prostatic cancer permanent seed implant boosts is currently the only application where LDR is receiving increasing clinical support. LDR still can play an equally effective role when brachytherapy is required in gynaecological, breast and head and neck cancer and soft tissue sarcomas. The meeting recognised the growing role of mHDR as the major modality in brachytherapy administration. It is further noted that changing circumstances and opinions regarding mHDR may exert a major influence on the continued future of LDR as a treatment modality. LDR brachytherapy special techniques are becoming less widely distributed and less frequently performed. Only a few centres remain where sufficient procedures are performed to give adequate training in a period of a few months. The meeting recommended that the Agency should promote the creation of regional training centres of excellence where the practice of LDR brachytherapy should be available. The meeting recommended that the Member States should continue support for LDR brachytherapy techniques beyond gynaecological techniques until such time as clear evidence is presented for discontinuation

  5. Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment

    Science.gov (United States)

    Miksys, N.; Xu, C.; Beaulieu, L.; Thomson, R. M.

    2015-08-01

    This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

  6. Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment

    International Nuclear Information System (INIS)

    This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

  7. Surface coating for prevention of metallic seed migration in tissues

    International Nuclear Information System (INIS)

    Purpose: In radiotherapy, metallic implants often detach from their deposited sites and migrate to other locations. This undesirable migration could cause inadequate dose coverage for permanent brachytherapy and difficulties in image-guided radiation delivery for patients. To prevent migration of implanted seeds, the authors propose a potential strategy to use a biocompatible and tissue-adhesive material called polydopamine. Methods: In this study, nonradioactive dummy seeds that have the same geometry and composition as commercial I-125 seeds were coated in polydopamine. Using scanning electron microscopy and x-ray photoelectron spectroscopy, the surface of the polydopamine-coated and noncoated seeds was characterized. The detachment stress between the two types of seeds and the tissue was measured. The efficacy of polydopamine-coated seed was investigated through in vitro migration tests by tracing the seed location after tissue implantation and shaking for given times. The cytotoxicity of the polydopamine coating was also evaluated. Results: The results of the coating characterization have shown that polydopamine was successfully coated on the surface of the seeds. In the adhesion test, the polydopamine-coated seeds had 2.1-fold greater detachment stress than noncoated seeds. From the in vitro test, it was determined that the polydopamine-coated seed migrated shorter distances than the noncoated seed. This difference was increased with a greater length of time after implantation. Conclusions: The authors suggest that polydopamine coating is an effective technique to prevent migration of implanted seeds, especially for permanent prostate brachytherapy

  8. Surface coating for prevention of metallic seed migration in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyunseok; Park, Jong In [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Won Seok; Park, Min [Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul 151-742 (Korea, Republic of); Son, Kwang-Jae [Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Bang, Young-bong [Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Choy, Young Bin, E-mail: ybchoy@snu.ac.kr, E-mail: sye@snu.ac.kr [Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul 110-744 (Korea, Republic of); Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul 110-744 (Korea, Republic of); Ye, Sung-Joon, E-mail: ybchoy@snu.ac.kr, E-mail: sye@snu.ac.kr [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2015-06-15

    Purpose: In radiotherapy, metallic implants often detach from their deposited sites and migrate to other locations. This undesirable migration could cause inadequate dose coverage for permanent brachytherapy and difficulties in image-guided radiation delivery for patients. To prevent migration of implanted seeds, the authors propose a potential strategy to use a biocompatible and tissue-adhesive material called polydopamine. Methods: In this study, nonradioactive dummy seeds that have the same geometry and composition as commercial I-125 seeds were coated in polydopamine. Using scanning electron microscopy and x-ray photoelectron spectroscopy, the surface of the polydopamine-coated and noncoated seeds was characterized. The detachment stress between the two types of seeds and the tissue was measured. The efficacy of polydopamine-coated seed was investigated through in vitro migration tests by tracing the seed location after tissue implantation and shaking for given times. The cytotoxicity of the polydopamine coating was also evaluated. Results: The results of the coating characterization have shown that polydopamine was successfully coated on the surface of the seeds. In the adhesion test, the polydopamine-coated seeds had 2.1-fold greater detachment stress than noncoated seeds. From the in vitro test, it was determined that the polydopamine-coated seed migrated shorter distances than the noncoated seed. This difference was increased with a greater length of time after implantation. Conclusions: The authors suggest that polydopamine coating is an effective technique to prevent migration of implanted seeds, especially for permanent prostate brachytherapy.

  9. AUTOMATIC SEGMENTATION OF PELVIS FOR BRACHYTHERAPY OF PROSTATE.

    Science.gov (United States)

    Kardell, M; Magnusson, M; Sandborg, M; Alm Carlsson, G; Jeuthe, J; Malusek, A

    2016-06-01

    Advanced model-based iterative reconstruction algorithms in quantitative computed tomography (CT) perform automatic segmentation of tissues to estimate material properties of the imaged object. Compared with conventional methods, these algorithms may improve quality of reconstructed images and accuracy of radiation treatment planning. Automatic segmentation of tissues is, however, a difficult task. The aim of this work was to develop and evaluate an algorithm that automatically segments tissues in CT images of the male pelvis. The newly developed algorithm (MK2014) combines histogram matching, thresholding, region growing, deformable model and atlas-based registration techniques for the segmentation of bones, adipose tissue, prostate and muscles in CT images. Visual inspection of segmented images showed that the algorithm performed well for the five analysed images. The tissues were identified and outlined with accuracy sufficient for the dual-energy iterative reconstruction algorithm whose aim is to improve the accuracy of radiation treatment planning in brachytherapy of the prostate. PMID:26567322

  10. Equivalent Biochemical Control and Improved Prostate-Specific Antigen Nadir After Permanent Prostate Seed Implant Brachytherapy Versus High-Dose Three-Dimensional Conformal Radiotherapy and High-Dose Conformal Proton Beam Radiotherapy Boost

    International Nuclear Information System (INIS)

    Purpose: Permanent prostate implant brachytherapy (PPI), three-dimensional conformal radiotherapy (3D-CRT), and conformal proton beam radiotherapy (CPBRT) are used in the treatment of localized prostate cancer, although no head-to-head trials have compared these modalities. We studied the biochemical control (biochemical no evidence of disease [bNED]) and prostate-specific antigen (PSA) nadir achieved with contemporary PPI, and evaluated it against 3D-CRT and CPBRT. Patients and Methods: A total of 249 patients were treated with PPI at the University of California, San Francisco, and the outcomes were compared with those from a 3D-CRT cohort and the published results of a high-dose CPBRT boost (CPBRTB) trial. For each comparison, subsets of the PPI cohort were selected with patient and disease criteria similar to those of the reference group. Results: With a median follow-up of 5.3 years, the bNED rate at 5 and 7 years achieved with PPI was 92% and 86%, respectively, using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, and 93% using the PSA nadir plus 2 ng/mL definition. Using the ASTRO definition, a 5-year bNED rate of 78% was achieved for the 3D-CRT patients compared with 94% for a comparable PPI subset and 93% vs. 92%, respectively, using the PSA nadir plus 2 ng/mL definition. The median PSA nadir for patients treated with PPI and 3D-CRT was 0.10 and 0.40 ng/mL, respectively (p < .0001). For the CPBRT comparison, the 5-year bNED rate after a CPBRTB was 91% using the ASTRO definition vs. 93% for a similar group of PPI patients. A greater proportion of PPI patients achieved a lower PSA nadir compared with those achieved in the CPBRTB trial (PSA nadir ≤0.5 ng/mL, 91% vs. 59%, respectively). Conclusion: We have demonstrated excellent outcomes in low- to intermediate-risk patients treated with PPI, suggesting at least equivalent 5-year bNED rates and a greater proportion of men achieving lower PSA nadirs compared with 3D-CRT or

  11. High Intensity Focused Ultrasound (HIFU) as a Salvage Treatment for Recurrent Prostate Cancer after Brachytherapy — a Feasibility Study

    Science.gov (United States)

    Chapman, Alexander T.; Rivens, Ian H.; Thompson, Alan C.; ter Haar, Gail R.

    2007-05-01

    HIFU may be an effective salvage treatment for patients who develop local recurrence after permanent low-dose brachytherapy. It has been suggested that the presence of seeds in the prostate may obstruct the HIFU beam or alter the heating characteristics of the prostate tissue. Acoustic field measurements were made using a membrane hydrophone and lesioning experiments were carried out in ex vivo bovine liver. These revealed a significant effect of the seeds on the HIFU focal region as well as a reduction in lesion length when seeds were placed in a pre-focal position. Further work is needed to evaluate the full effects of implanted brachytherapy seeds on the clinical delivery of HIFU.

  12. Salvage/Adjuvant Brachytherapy After Ophthalmic Artery Chemosurgery for Intraocular Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Jasmine H., E-mail: francij1@mskcc.org [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Barker, Christopher A.; Wolden, Suzanne L.; McCormick, Beryl; Segal, Kira; Cohen, Gil [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Gobin, Y. Pierre; Marr, Brian P. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York (United States); Brodie, Scott E. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Mount Sinai School of Medicine, New York, New York (United States); Dunkel, Ira J.; Abramson, David H. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York (United States)

    2013-11-01

    Purpose: To evaluate the efficacy and toxicity of brachytherapy after ophthalmic artery chemosurgery (OAC) for retinoblastoma. Methods and Materials: This was a single-arm, retrospective study of 15 eyes in 15 patients treated with OAC followed by brachytherapy at (blinded institution) between May 1, 2006, and December 31, 2012, with a median 19 months' follow-up from plaque insertion. Outcome measurements included patient and ocular survival, visual function, and retinal toxicity measured by electroretinogram (ERG). Results: Brachytherapy was used as adjuvant treatment in 2 eyes and as salvage therapy in 13 eyes of which 12 had localized vitreous seeding. No patients developed metastasis or died of retinoblastoma. The Kaplan-Meier estimate of ocular survival was 79.4% (95% confidence interval 48.7%-92.8%) at 18 months. Three eyes were enucleated, and an additional 6 eyes developed out-of-target volume recurrences, which were controlled with additional treatments. Patients with an ocular complication had a mean interval between last OAC and plaque of 2.5 months (SD 2.3 months), which was statistically less (P=.045) than patients without ocular complication who had a mean interval between last OAC and plaque of 6.5 months (SD 4.4 months). ERG responses from pre- versus postplaque were unchanged or improved in more than half the eyes. Conclusions: Brachytherapy following OAC is effective, even in the presence of vitreous seeding; the majority of eyes maintained stable or improved retinal function following treatment, as assessed by ERG.

  13. Salvage/Adjuvant Brachytherapy After Ophthalmic Artery Chemosurgery for Intraocular Retinoblastoma

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy and toxicity of brachytherapy after ophthalmic artery chemosurgery (OAC) for retinoblastoma. Methods and Materials: This was a single-arm, retrospective study of 15 eyes in 15 patients treated with OAC followed by brachytherapy at (blinded institution) between May 1, 2006, and December 31, 2012, with a median 19 months' follow-up from plaque insertion. Outcome measurements included patient and ocular survival, visual function, and retinal toxicity measured by electroretinogram (ERG). Results: Brachytherapy was used as adjuvant treatment in 2 eyes and as salvage therapy in 13 eyes of which 12 had localized vitreous seeding. No patients developed metastasis or died of retinoblastoma. The Kaplan-Meier estimate of ocular survival was 79.4% (95% confidence interval 48.7%-92.8%) at 18 months. Three eyes were enucleated, and an additional 6 eyes developed out-of-target volume recurrences, which were controlled with additional treatments. Patients with an ocular complication had a mean interval between last OAC and plaque of 2.5 months (SD 2.3 months), which was statistically less (P=.045) than patients without ocular complication who had a mean interval between last OAC and plaque of 6.5 months (SD 4.4 months). ERG responses from pre- versus postplaque were unchanged or improved in more than half the eyes. Conclusions: Brachytherapy following OAC is effective, even in the presence of vitreous seeding; the majority of eyes maintained stable or improved retinal function following treatment, as assessed by ERG

  14. Poster — Thur Eve — 77: Implanted Brachythearpy Seed Movement due to Transrectal Ultrasound Probe-Induced Prostate Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D; Usmani, N; Sloboda, R [Cross Cancer Institute, Edmonton, Alberta (Canada); University of Alberta, Edmonton, Alberta (Canada); Meyer, T; Husain, S; Angyalfi, S [Tom Baker Cancer Centre, Calgary, Alberta (Canada); University of Calgary, Calgary, Alberta (Canada); Kay, I [Canterbury District Health Board, Christchurch (New Zealand)

    2014-08-15

    The study investigated the movement of implanted brachytherapy seeds upon transrectal US probe removal, providing insight into the underlying prostate deformation and an estimate of the impact on prostate dosimetry. Implanted seed distributions, one obtained with the prostate under probe compression and another with the probe removed, were reconstructed using C-arm fluoroscopy imaging. The prostate, delineated on ultrasound images, was registered to the fluoroscopy images using seeds and needle tracks identified on ultrasound. A deformation tensor and shearing model was developed to correlate probe-induced seed movement with position. Changes in prostate TG-43 dosimetry were calculated. The model was used to infer the underlying prostate deformation and to estimate the location of the prostate surface in the absence of probe compression. Seed movement patterns upon probe removal reflected elastic decompression, lateral shearing, and rectal bending. Elastic decompression was characterized by expansion in the anterior-posterior direction and contraction in the superior-inferior and lateral directions. Lateral shearing resulted in large anterior movement for extra-prostatic seeds in the lateral peripheral region. Whole prostate D90 increased up to 8 Gy, mainly due to the small but systematic seed movement associated with elastic decompression. For selected patients, lateral shearing movement increased prostate D90 by 4 Gy, due to increased dose coverage in the anterior-lateral region at the expense of the posterior-lateral region. The effect of shearing movement on whole prostate D90 was small compared to elastic decompression due to the subset of peripheral seeds involved, but is expected to have greater consequences for local dose coverage.

  15. Physical basics and clinical realization of interstitial brachytherapy of the prostate with iodine 125; Physikalische Grundlagen und klinische Durchfuehrung der interstitiellen Brachytherapie der Prostata mit Jod-125

    Energy Technology Data Exchange (ETDEWEB)

    Kaulich, T.W.; Nuesslin, F. [Abt. Medizinische Physik, Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany); Lamprecht, U.; Bamberg, M. [Abt. Radioonkologie, Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany); Paulsen, F.; Loeser, W.; Bichler, K.H. [Universitaetsklinik fuer Urologie, Tuebingen (Germany); Kahmann, F.; Henkel, T.O. [Ambulantes OP-Zentrum im Ullsteinhaus, IFAP, Berlin (Germany); Maurer, U. [Klinik fuer Strahlentherapie, Universitaetsklinikum, RWTH Aachen (Germany)

    2002-10-01

    Background: Interstitial brachytherapy with I-125 seeds can be used for successful treatment of early stage prostate cancer. There is presented the technique of permanent transperineal implantation of I-125 seeds with intraoperative treatment planning which is suited for the treatment of prostate cancer up to the clinical stage of T2a. Material and methods: Some weeks before the implantation of the seeds the prostate volume is determined using transrectal ultrasound (TRUS) so as to estimate the required number of I-125 seeds. At the outset of the treatment the prostate is stabilized by two perineally inserted needles. Subsequently there is carried out an ultrasound guide treatment planning that allows to optimize the distribution of the seeds within the prostate. In interstitial brachytherapy we use RAPID STRANDs {sup trademark}, i.e. the I-125 seeds are embedded in vicryl suture at distances of 1 cm. During implantation of the I-125 seeds the transversal placement of the applicator needles is controlled by TRUS and the cranio-caudal placement of the applicator needles is controlled using the fluoroscopic unit as well as TRUS. About 4 weeks after the implantation of the seeds there is carried out a postoperative computation of the dose distribution of the implant using CT imaging. Results: The procedure possesses the advantage that ultrasound imaging, treatment planning and seed implantation are carried out with the prostate remaining in an unaltered position. During implantation the combined imaging of TRUS and fluoroscopy allows a safe placement of the seeds within the prostate. Conclusion: The methods for the calculation of the actually attained dose distribution must still be optimized, because the postoperative examination of the individual results has so far been possible only with difficulties resulting from methodological inconveniences. (orig.) [German] Hintergrund: Durch interstitielle Brachytherapie mit Jod-125-Seeds kann das lokal begrenzte

  16. In vivo dosimetry in brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Beddar, Sam; Andersen, Claus Erik; Kertzscher Schwencke, Gustavo Adolfo Vladimir; Cygler, Joanna E.

    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 the...

  17. Brachytherapy in coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Chun [Chonnam National University Medicine School, Gwangju (Korea, Republic of)

    2006-04-15

    Coronary artery disease is a leading cause of morbidity and mortality across the world. Percutaneous coronary intervention has become the major technique of revascularization. However, restenosis remains a major limitation of this procedure. Recently the need for repeat intervention due to restenosis, the most vexing long-term failure of percutaneous coronary intervention, has been significantly reduced owing to the introduction to two major advances, intracoronary brachytherapy and the drug-eluting stents, intracoronary brachytherapy has been employed in recent years to prevent restenosis lesions with effective results, principally in in-stent restenosis. Restenosis is generally considered as an excessive form of normal wound healing divided up in processes: elastic recoil, neointimal hyperplasia, and negative vascular remodeling. Restenosis has previously been regarded as a proliferative process in which neointimal thickening, mediated by a cascade of inflammatory mediators and other factors, is the key factor. Ionizing radiation has been shown to decrease the proliferative response to injury in animal models of restenosis. Subsequently, several randomized, double-blind trials have demonstrated that intracoronary brachytherapy can reduce the rates to both angiographic restenosis and clinical event rates in patients undergoing percutaneous coronary intervention for in-stent restenosis. Some problems, such as late thrombosis and edge restenosis, have been identified as limiting factors of this technique. Brachytherapy is a promising method of preventing and treating coronary artery restenosis.

  18. Dosimetry in intravascular brachytherapy

    International Nuclear Information System (INIS)

    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 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)

  19. Assessment of dose-volume histograms in brachytherapy 3D high-rate; Evaluacion de los histogramas dosis volumen en braquiterapia de alta tasa 3D

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Barrado, A.; Tripero Oter, J.; Sanchez Jimenez, E.; Sanchez-Reyes, A.

    2013-07-01

    The use of systems of treatment planning using 3D reconstruction algorithms are becoming more frequent in brachytherapy treatments. The implementation of these systems entails great qualitative and quantitative procedural changes in the way to evaluate the clinical dosimetry about the 2D classical systems. This paper describes the experience of our Centre in employment and prescription dose using histograms dose-volume in the treatment of brachytherapy of high rate. (Author)

  20. Dose optimization in simulated permanent interstitial implant of prostate brachytherapy

    International Nuclear Information System (INIS)

    Any treatment of cancer that uses some modality of radiotherapy is planned before being executed. In general the goal in radiotherapy is to irradiate the target to be treated minimizing the incidence of radiation in healthy surrounding tissues. The planning differ among themselves according to the modality of radiotherapy, the type of cancer and where it is located. This work approaches the problem of dose optimization for the planning of prostate cancer treatment through the modality of low dose-rate brachytherapy with Iodine 125 or Palladium 103 seeds. An algorithm for dose calculation and optimization was constructed to find the seeds configuration that better fits the relevant clinical criteria such as as the tolerated dose by the urethra and rectum and the desired dose for prostate. The algorithm automatically finds this configuration from the prostate geometry established in two or three dimensions by using images of ultrasound, magnetic resonance or tomography and from the establishment of minimum restrictions to the positions of the seeds in the prostate and needles in a template. Six patterns of seeds distribution based on clinical criteria were suggested and tested in this work. Each one of these patterns generated a space of possible seeds configurations for the prostate tested by the dose calculation and optimization algorithm. The configurations that satisfied the clinical criteria were submitted to a test according to an optimization function suggested in this work. The configuration that produced maximum value for this function was considered the optimized one. (author)

  1. Radiological protection of patients in brachytherapy

    International Nuclear Information System (INIS)

    Full text: The prefix 'brachy' means short-range, so brachytherapy is the administration of radiation therapy using small radioactive sources in the form of needles, tubes, wires or seeds, which are placed within the tumor -interstitial form- or very near of it, superficially or in an endo-cavity form. This technique, which was limited by the size of the primary tumor, has the advantage, that the radiation, can be adjusted to the size and shape of the tumor volume and the radioisotope used, - short range -, is selected with the criteria of getting the dose in the organs at risk, as low as possible, making what it is known as conformal radiotherapy. Radioactive sources may be permanent or temporary implants. The application of radioactive material, can be manually or automatically. In the first case, a major breakthrough from the radioprotection point of view, was the use of afterloading devices, methodology highly recommended to reduce the radiation exposure to staff. With the development of technology, remotely controlled afterloading devices were introduced, which in addition to complying with the above requirement, allow the source to move in different positions along catheters housed in one or more channels, making therapeutic brachytherapy treatments in tumor volumes possible, that due to its length, decades ago would have been an unthinkable deal. In all cases, sources, which may vary from the 3 mm in length, 125 Iodine or 198 Gold seeds, to extensive wires of 192 Iridium, are encapsulated for two main purposes: preventing leakage of radioactive material and absorption of unwanted radiation, alpha and beta, produced by the radioactive decay. Consequently, it should be highly unlikely that the radioactive material, could be lost or located in the patient, in a different place of the one that was planned. However, history shows us the opposite. Its is known the kind of deterministic effect that radiation is going to produce in the tumor, where the severity of

  2. Brachytherapy: Physical and clinical aspects

    International Nuclear Information System (INIS)

    Brachytherapy is a term used to describe the short distance treatment of cancer with radiation from small, encapsulated radionuclide sources. This type of treatment is given by placing sources directly into or near the volume to be treated. The dose is then delivered continuously, either over a short period of time (temporary implants) or over the lifetime of the source to a complete decay (permanent implants). Most common brachytherapy sources emit photons; however, in a few specialized situations b or neutron emitting sources are used. There are two main types of brachytherapy treatment: 1) Intracavitary, in which the sources are placed in body cavities close to the tumour volume; 2) Interstitial, in which the sources are implanted within the tumour volume. Intracavitary treatments are always temporary, of short duration, while interstitial treatments may be temporary or permanent. Temporary implants are inserted using either manual or remote afterloading procedures. Other, less common forms of brachytherapy treatments include surface plaque, intraluminal, intraoperative and intravascular source applications; for these treatments either g or b emitting sources are used. The physical advantage of brachytherapy treatments compared with external beam radiotherapy is the improved localized delivery of dose to the target volume of interest. The disadvantage is that brachytherapy can only be used in cases in which the tumour is well localized and relatively small. In a typical radiotherapy department about 10-20% of all radiotherapy patients are treated with brachytherapy. Several aspects must be considered when giving brachytherapy treatments. Of importance is the way in which the sources are positioned relative to the volume to be treated, and several different models have been developed over the past decades for this purpose. The advantage of using a well established model is that one benefits from the long experience associated with such models and that one can

  3. Physical basics and clinical realization of interstitial brachytherapy of the prostate with iodine 125

    International Nuclear Information System (INIS)

    Background: Interstitial brachytherapy with I-125 seeds can be used for successful treatment of early stage prostate cancer. There is presented the technique of permanent transperineal implantation of I-125 seeds with intraoperative treatment planning which is suited for the treatment of prostate cancer up to the clinical stage of T2a. Material and methods: Some weeks before the implantation of the seeds the prostate volume is determined using transrectal ultrasound (TRUS) so as to estimate the required number of I-125 seeds. At the outset of the treatment the prostate is stabilized by two perineally inserted needles. Subsequently there is carried out an ultrasound guide treatment planning that allows to optimize the distribution of the seeds within the prostate. In interstitial brachytherapy we use RAPID STRANDs trademark, i.e. the I-125 seeds are embedded in vicryl suture at distances of 1 cm. During implantation of the I-125 seeds the transversal placement of the applicator needles is controlled by TRUS and the cranio-caudal placement of the applicator needles is controlled using the fluoroscopic unit as well as TRUS. About 4 weeks after the implantation of the seeds there is carried out a postoperative computation of the dose distribution of the implant using CT imaging. Results: The procedure possesses the advantage that ultrasound imaging, treatment planning and seed implantation are carried out with the prostate remaining in an unaltered position. During implantation the combined imaging of TRUS and fluoroscopy allows a safe placement of the seeds within the prostate. Conclusion: The methods for the calculation of the actually attained dose distribution must still be optimized, because the postoperative examination of the individual results has so far been possible only with difficulties resulting from methodological inconveniences. (orig.)

  4. Online gamma-camera imaging of 103Pd seeds (OGIPS) for permanent breast seed implantation

    International Nuclear Information System (INIS)

    Permanent brachytherapy seed implantation is being investigated as a mode of accelerated partial breast irradiation for early stage breast cancer patients. Currently, the seeds are poorly visualized during the procedure making it difficult to perform a real-time correction of the implantation if required. The objective was to determine if a customized gamma-camera can accurately localize the seeds during implantation. Monte Carlo simulations of a CZT based gamma-camera were used to assess whether images of suitable quality could be derived by detecting the 21 keV photons emitted from 74 MBq 103Pd brachytherapy seeds. A hexagonal parallel hole collimator with a hole length of 38 mm, hole diameter of 1.2 mm and 0.2 mm septa, was modeled. The design of the gamma-camera was evaluated on a realistic model of the breast and three layers of the seed distribution (55 seeds) based on a pre-implantation CT treatment plan. The Monte Carlo simulations showed that the gamma-camera was able to localize the seeds with a maximum error of 2.0 mm, using only two views and 20 s of imaging. A gamma-camera can potentially be used as an intra-procedural image guidance system for quality assurance for permanent breast seed implantation

  5. Physical aspects of radioisotope brachytherapy

    International Nuclear Information System (INIS)

    The present report represents an attempt to provide, within a necessarily limited compass, an authoritative guide to all important physical aspects of the use of sealed gamma sources in radiotherapy. Within the report, reference is made wherever necessary to the more extensive but scattered literature on this subject. While this report attempts to cover all the physical aspects of radioisotope 'brachytherapy' it does not, of course, deal exhaustively with any one part of the subject. 384 refs, 3 figs, 6 tabs

  6. Risk analysis of brachytherapy events

    International Nuclear Information System (INIS)

    For prevention radiological events it is necessary to identify hazardous situation and to analyse the nature of committed errors. Though the recommendation on the classification and prevention of radiological events: Radiological accidents has been prepared in the framework of Czech Society of Radiation Oncology, Biology and Physics and it was approved by Czech regulatory body (SONS) in 1999, only a few reports have been submitted up to now from brachytherapy practice. At the radiotherapy departments attention has been paid more likely to the problems of dominant teletherapy treatments. But in the two last decades the usage of brachytherapy methods has gradually increased because .nature of this treatment well as the possibilities of operating facility have been completely changed: new radionuclides of high activity are introduced and sophisticate afterloading systems controlled by computers are used. Consequently also the nature of errors, which can occurred in the clinical practice, has been changing. To determine the potentially hazardous parts of procedure the so-called 'process tree', which follows the flow of entire treatment process, has been created for most frequent type of applications. Marking the location of errors on the process tree indicates where failures occurred and accumulation of marks along branches show weak points in the process. Analysed data provide useful information to prevent medical events in brachytherapy .The results strength the requirements given in Recommendations of SONS and revealed the need for its amendment. They call especially for systematic registration of the events. (authors)

  7. Iodine-125 interstitial brachytherapy for experimental liver cancer

    Institute of Scientific and Technical Information of China (English)

    ZHOU Fei-guo; YAN Jian-jun; HUANG Liang; LIU Cai-feng; ZHANG Xiang-hua; ZHOU Wei-ping; YAN Yi-qun

    2007-01-01

    Objective:To study the effect of iodine-125 interstitial brachytherapy on liver cancer.Methods:Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into the flank of BALB/c nude mice.Nude mice with tumor of 5 mm in diameter were randomly divided into 2 groups(n=10).One iodine-125 seed of apparent activity 0.8 mCi was implanted into the center of tumor in treatment group,whereas an inactive seed was implanted in control group.The other 20 nude mice with tumor reaching 10 mm in diameter were also treated as above.The size of tumor was determined weekly after implantation,and pathological examination and blood routine were taken on the 28th day.Results:Tumor growth was obviously inhibited in treatment group of tumor of 5 mm in diameter,and there was statistically significant difference in tumor volume between treatment and control groups(P<0.01).Around iodine-125 seed,apparent necrosis of tumor was shown in treatment group,accompanied by karyopyknosis and reduced plasma in residual tumor cells microscopically.Tumor growth was not inhibited in either treatment or control group of tumor of 10 mm in diameter.There was no obvious adverse effect except for decreased white blood cells in treatment groups.Conclusion:There is certain effect of iodine-125 interstitial brachytherapy on liver cancer,which is associated with the size of tumor.

  8. 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.

  9. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    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.

  10. Dynamic rotating-shield brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process.Methods: A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D90 for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and 192Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D2cc of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with α/β= 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively.Results: For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes/fraction (min/fx) assuming a 10 Ci192Ir source, and the average HR-CTV D90 was 78.9 Gy. In order to match the HR-CTV D90 of IS + ICBT, D-RSBT required an average of 10.1 min/fx more delivery time, and S-RSBT required 6.7 min/fx more. If an additional 20 min/fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D90 above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively.Conclusions: For cervical cancer patients, D

  11. Dynamic rotating-shield brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunlong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Yang, Wenjun [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Wu, Xiaodong [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)

    2013-12-15

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

  12. A brachytherapy model-based dose calculation algorithm -AMIGOBrachy

    International Nuclear Information System (INIS)

    Brachytherapy treatments have been performed based on TG-43U1 water dose formalism which neglects human tissues density and composition, body interfaces and applicator effects. As these effects could be relevant for brachytherapy energy range, modern treatment planning systems (TPS) are now available that are based on model-based dose calculation algorithms (MBDCA) enabling heterogeneity corrections, which are needed to replace the TG-43U1 water dose formalism for a more accurate approach. The recently published AAPM TG-186 report is the first step towards to a TPS taking into account heterogeneities, applicators and human body complexities. This report presents the current status, recommendations for clinical implementation and specifies research areas where considerable efforts are necessary to move forward with MBDCA. Monte Carlo (MC) codes are an important part of the current algorithms due their flexibility and accuracy, although, almost all MC codes present no interface to process the large amount of data necessary to perform clinical cases simulations, which may include hundreds of dwell positions, inter-seed attenuation, image processing and others time consuming issues that can make MC simulation unfeasible without a pre-processing interface. This work presents the AMIGOBrachy interface tool (Algorithm for Medical Image-based Generating Object - Brachytherapy module) which provides all the pre-processing task needed for the simulation. This software can import and edit treatments plans from BrachyVision™ (Varian Medical Systems, Inc., Palo Alto, CA) and ONCENTRA™ (Elekta AB, Stockholm, Sweden), and also create a new plan through contouring resources, needle recognition, HU segmentation, combining voxels phantoms with analytical geometries to define applicators and other resources used to create MCNP5 input and analyze the results. This work presents some results used to validate the software and to evaluate the heterogeneities impact in a clinical case

  13. 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.

  14. High dose rate brachytherapy for oral cancer

    International Nuclear Information System (INIS)

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

  15. I-125 seed dose estimates in heterogeneous phantom

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Isabela S.L.; Antunes, Paula C.G.; Cavalieri, Tassio A.; Moura, Eduardo S.; Zeituni, Carlos A.; Yoriyaz, Helio, E-mail: isabela.slbranco@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Brachytherapy plays an important role in the healing process involving tumors in a variety of diseases. Several studies are currently conducted to examine the heterogeneity effects of different tissues and organs in brachytherapy clinical situations and a great effort has been made to incorporate new methodologies to estimate doses with greater accuracy. The objective of this study is to contribute to the assessment of heterogeneous effects on dose due to I-125 brachytherapy source in the presence of different materials with different densities and chemical compositions. The study was performed in heterogeneous phantoms using materials that simulate human tissues. Among these is quoted: breast, fat, muscle, lungs (exhaled and inhaled) and bones with different densities. Monte Carlo simulations for dose calculation in these phantoms were held and subsequently validated. The model 6711 I-125 seed was considered because it is widely used as a brachytherapy permanent implant and the one used in clinics and hospitals in Brazil. Thermoluminescent dosimeters TLD-700 (LiF: Mg, Ti) were simulated for dose assess. Several tissue configurations and positioning of I-125 sources were studied by simulations for future dose measurements. The methodology of this study so far shall be suitable for accurate dosimetric evaluation for different types of brachytherapy treatments, contributing to brachytherapy planning systems complementation allowing a better assessment of the dose actually delivered to the patient. (author)

  16. A fully actuated robotic assistant for MRI-guided prostate biopsy and brachytherapy

    Science.gov (United States)

    Li, Gang; Su, Hao; Shang, Weijian; Tokuda, Junichi; Hata, Nobuhiko; Tempany, Clare M.; Fischer, Gregory S.

    2013-03-01

    Intra-operative medical imaging enables incorporation of human experience and intelligence in a controlled, closed-loop fashion. Magnetic resonance imaging (MRI) is an ideal modality for surgical guidance of diagnostic and therapeutic procedures, with its ability to perform high resolution, real-time, high soft tissue contrast imaging without ionizing radiation. However, for most current image-guided approaches only static pre-operative images are accessible for guidance, which are unable to provide updated information during a surgical procedure. The high magnetic field, electrical interference, and limited access of closed-bore MRI render great challenges to developing robotic systems that can perform inside a diagnostic high-field MRI while obtaining interactively updated MR images. To overcome these limitations, we are developing a piezoelectrically actuated robotic assistant for actuated percutaneous prostate interventions under real-time MRI guidance. Utilizing a modular design, the system enables coherent and straight forward workflow for various percutaneous interventions, including prostate biopsy sampling and brachytherapy seed placement, using various needle driver configurations. The unified workflow compromises: 1) system hardware and software initialization, 2) fiducial frame registration, 3) target selection and motion planning, 4) moving to the target and performing the intervention (e.g. taking a biopsy sample) under live imaging, and 5) visualization and verification. Phantom experiments of prostate biopsy and brachytherapy were executed under MRI-guidance to evaluate the feasibility of the workflow. The robot successfully performed fully actuated biopsy sampling and delivery of simulated brachytherapy seeds under live MR imaging, as well as precise delivery of a prostate brachytherapy seed distribution with an RMS accuracy of 0.98mm.

  17. SU-E-J-263: Dosimetric Analysis On Breast Brachytherapy Based On Deformable Image Registration

    International Nuclear Information System (INIS)

    Purpose: To quantitatively compare and evaluate the dosimetry difference between breast brachytherapy protocols with different fractionation using deformable image registration. Methods: The accumulative dose distribution for multiple breast brachytherapy patients using four different applicators: Contura, Mammosite, Savi, and interstitial catheters, under two treatment protocols: 340cGy by 10 fractions in 5 days and 825cGy by 3 fractions in 2days has been reconstructed using a two stage deformable image registration approach. For all patients, daily CT was acquired with the same slice thickness (2.5mm). In the first stage, the daily CT images were rigidly registered to the initial planning CT using the registration module in Eclipse (Varian) to align the applicators. In the second stage, the tissues surrounding the applicator in the rigidly registered daily CT image were non-rigidly registered to the initial CT using a combination of image force and the local constraint that enforce zero normal motion on the surface of the applicator, using a software developed in house. We calculated the dose distribution in the daily CTs and deformed them using the final registration to convert into the image domain of the initial planning CT. The accumulative dose distributions were evaluated by dosimetry parameters including D90, V150 and V200, as well as DVH. Results: Dose reconstruction results showed that the two day treatment has a significant dosimetry improvement over the five day protocols. An average daily drop of D90 at 1.3% of the prescription dose has been observed on multiple brachytherapy patients. There is no significant difference on V150 and V200 between those two protocols. Conclusion: Brachytherapy with higher fractional dose and less fractions has an improved performance on being conformal to the dose distribution in the initial plan. Elongated brachytherapy treatments need to consider the dose uncertainty caused by the temporal changes of the soft tissue

  18. The use of TLDs for brachytherapy dosimetry

    International Nuclear Information System (INIS)

    Thermoluminescent dosimeters (TLDs) are routinely used to measure the dose around brachytherapy sources due to their small size and high precision. This work presents a concise overview of the use of LiF:Mg,Ti TLDs for brachytherapy dosimetry including the experimental procedures required to achieve high-precision measurements as well as new results regarding the intrinsic energy dependence with some of the commonly used brachytherapy sources. Equations to correct TLD light output to air kerma are outlined and a description of the method to determine the intrinsic energy dependence is presented. For the intrinsic energy dependence investigation, a review of previously published results is presented as well as new experimental results using 125I, 103Pd, 192Ir, and miniature x-ray brachytherapy sources at the University of Wisconsin Medical Radiation Research Center (UWMRRC). The results of these experiments are consistent with previous work and give valuable insight to investigators using TLDs for brachytherapy measurements. - Highlights: • Brachytherapy measurements with LiF:Mg,Ti TLDs performed. • Intrinsic energy dependence for several brachytherapy sources determined. • New LiF:Mg,Ti energy dependence results compared with previous data for x-ray beams. • Uncertainty of LiF:Mg,Ti TLD measurements reviewed

  19. The Transition from 2-D Brachytherapy to 3-D High Dose Rate Brachytherapy

    International Nuclear Information System (INIS)

    Brachytherapy is a major treatment modality in the treatment of common cancers including cervical cancer. This publication addresses the recent technological change in brachytherapy treatment planning with better access to 3-D volumetric patient imaging modalities including computed tomography (CT) and magnetic resonance (MR) as opposed to traditional 2-D planar images. In the context of 2-D and 3-D brachytherapy, the publication provides definitions, clinical indications, transitioning milestones, commissioning steps, quality assurance measures, and a related questionnaire. Staff training and resourcing are also addressed. The publication will serve as a guide to radiotherapy departments in Member States who wish to make the transition from 2-D to 3-D brachytherapy

  20. The PROSPER robot for prostate brachytherapy: design, development and preclinical evaluation

    International Nuclear Information System (INIS)

    Objectives: reporting the design, development and experiments of a new robotic system for prostate brachytherapy including prostate tracking and MRI to Ultrasound registration. Material and methods: a robot for trans-perineal needle insertion has been developed. It includes the ability to track the prostate position and shape. Experiments on 90 targets inside 9 deformable phantoms have been conducted. A feasibility on 2 cadavers has also been performed. The robot had to place glass seeds simulating brachytherapy seeds as close as possible to physical targets included into the phantom or inside the prostates. A post-operative CT scan of the phantom or prostate was performed in order to measure the accuracy of the system. Results: the median accuracy was 2.73 mm with a median prostate motion of 5.46 mm. The accuracy in the base region was superior to the accuracy in the apex region (2.28 mm vs 3.83 mm, p≤0.01) and was not significantly different for horizontal or oblique needles (2.7 vs 2.82 mm, p=0.18). Cadaver experiments demonstrated that the approach was feasible and that the robot could be used in a real clinical environment. Conclusion: the robot for prostate brachytherapy is the first system enabling prostate tracking. Targets can be accurately reached despite prostate motion and deformation. It could be applied to focal therapy for prostate cancer. (author)

  1. Synthesis of phosphosilicate matrix for application to brachytherapy sources

    International Nuclear Information System (INIS)

    Brachytherapy with beta sources can be useful for in situ radiotherapy of cancers where tiny radioactive seeds are injected directly into the tumor. Phosphorus 31P can be activated to b-emitter 32P by neutron activation with a half-life of 14.3 days. In this work, phosphosilicate matrices were synthesized through sol-gel process by hydrolysis and condensation of the tetraethylorthosilicate (TEOS) under two different conditions of synthesis. In both conditions the phosphoric acid and drying control chemical additives (DCCA's) were the same. Three drying control chemical additives were utilized: propylene carbonate, N,N-dimethylformamide and ethylene glycol. The casting solutions were prepared with phosphorus content of 3.2 wt.% and xerogels were thermally treated at 900 deg C. Different microstructures were observed under different conditions of synthesis. The microstructures of phosphosilicate matrices obtained with ethylene glycol and without DCCA's have shown the presence of a globular structure regions with large amount of phosphorous. (author)

  2. A new human eye model for ophthalmic brachytherapy dosimetry

    International Nuclear Information System (INIS)

    The present work proposes a new mathematical eye model for ophthalmic brachytherapy dosimetry. This new model includes detailed description of internal structures that were not treated in previous works, allowing dose determination in different regions of the eye for a more adequate clinical analysis. Dose calculations were determined with the MCNP-4C Monte Carlo particle transport code running n parallel environment using PVM. The Amersham CKA4 ophthalmic applicator has been chosen and the depth dose distribution has been determined and compared to those provide by the manufacturer. The results have shown excellent agreement. Besides, absorbed dose values due to both 125I seeds and 60Co plaques were obtained for each one of the different structures which compose the eye model and can give relevant information in eventual clinical analyses. (authors)

  3. Use of Monte Carlo Methods in brachytherapy

    International Nuclear Information System (INIS)

    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)

  4. Definition study of the project Dosimetry Brachytherapy

    International Nuclear Information System (INIS)

    The purpose of the research project Dosimetry Brachytherapy is the standardization of calibration methods and quality control procedures used for Brachytherapy sources. Proposals to develop measurement standards and methods for calibrating these sources are presented. Brachytherapy sources will be calibrated in terms of reference airkerma rate or in terms of absorbed dose in water. Therefore, in this project, special attention will be given to the in-phantom measurement method described by Meertens and the use of re-entrant ionisation chambers as transfer standards. In this report, a workplan and time schedule is included. (author). 19 refs.; 1 fig

  5. CT based HDR brachytherapy for intracavitary applications

    International Nuclear Information System (INIS)

    Brachytherapy is most commonly used in combination with external radiotherapy for gynecological cancers of cervix, vagina and endometrium. The characteristic rapid fall off of the dose in brachytherapy makes it useful to deliver a localized high dose to tumor. In gynecological applications the dose limiting critical structures are bladder and rectum. The dose received by rectum and bladder has been an interesting issue all these decades. This work presents the dosimetric and planning aspects of CT based High Dose Rate brachytherapy for intracavitary applications

  6. SU-E-T-397: Include Organ Deformation Into Dose Calculation of Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Prostate brachytherapy is an important curative treatment for patients with localized prostate cancer. In brachytherapy, rectal balloon is generally needed to adjust for unfavorable prostate position for seed placement. However, rectal balloon causes prostate deformation, which is not accounted for in dosimetric planning. Therefore, it is possible that brachytherapy dosimetry deviates significantly from initial plan when prostate returns to its non-deformed state (after procedure). The goal of this study is to develop a method to include prostate deformation into the treatment planning of brachytherapy dosimetry. Methods: We prospectively collected ultrasound images of prostate pre- and post- rectal balloon inflation from thirty five consecutive patients undergoing I-125 brachytherapy. Based on the cylinder coordinate systems, we learned the initial coordinate transformation parameters between the manual segmentations of both deformed and non-deformed prostates of each patient in training set. With the nearest-neighbor interpolation, we searched the best transformation between two coordinate systems to maximum the mutual information of deformed and non-deformed images. We then mapped the implanted seeds of five selected patients from the deformed prostate into non-deformed prostate. The seed position is marked on original pre-inflation US image and it is imported into VariSeed software for dose calculation. Results: The accuracy of image registration is 87.5% as quantified by Dice Index. The prostate coverage V100% dropped from 96.5±0.5% of prostate deformed plan to 91.9±2.6% (p<0.05) of non-deformed plan. The rectum V100% decreased from 0.44±0.26 cc to 0.10±0.18 cc (p<0.05). The dosimetry of the urethra showed mild change but not significant: V150% changed from 0.05±0.10 cc to 0.14±0.15 cc (p>0.05) and D1% changed from 212.9±37.3 Gy to 248.4±42.8 Gy (p>0.05). Conclusion: We have developed a deformable image registration method that allows

  7. Brachytherapy with 125-Iodine sources: transport and radiation protection

    International Nuclear Information System (INIS)

    The estimates for the year 2009 show that 466,730 new cancer cases will occur in Brazil. Prostate cancer is the second most incident type. Brachytherapy, a type of radiotherapy, with Iodine-125 sources are an important form of treatment for this kind of cancer. The Instituto de Pesquisas Energeticas e Nucleares (IPEN) created a project to develop a national prototype of these sources and is implementing a facility for local production. The seeds manufacture in Brazil will allow to diminish the treatment cost and make it possible for a larger number of patients. While the laboratory is not ready, the IPEN import and it distributes seeds. This work aim is to present and evaluate the transport procedures and the radiological protection applied to imported sources in order to assist the procedures for the new laboratory implementation. Before sending to hospitals, the seeds are packed by a radioprotector supervisor, in accordance with CNEN NE 5.01 standard 'Radioactive Material Transport'. Despite Iodine-125 presents low energy photons, around 29 keV, local and personal dosimeters are used during the transport process, as described in CNEN NN 3.01 standard 'Radiological Protection Basic Guideline'. All the results show no contamination and very low exposure, proving the method to be valid. The transport procedure used is correct, according to the regulations. As an result of this work, a new dosimeter should be installed and evaluate in future study. (author)

  8. MRI/TRUS data fusion for prostate brachytherapy. Preliminary results

    CERN Document Server

    Reynier, Christophe; Fourneret, Philippe; Dusserre, André; Gay-Jeune, Cécile; Descotes, Jean-Luc; Bolla, Michel; Giraud, Jean-Yves

    2008-01-01

    Prostate brachytherapy involves implanting radioactive seeds (I125 for instance) permanently in the gland for the treatment of localized prostate cancers, e.g., cT1c-T2a N0 M0 with good prognostic factors. Treatment planning and seed implanting are most often based on the intensive use of transrectal ultrasound (TRUS) imaging. This is not easy because prostate visualization is difficult in this imaging modality particularly as regards the apex of the gland and from an intra- and interobserver variability standpoint. Radioactive seeds are implanted inside open interventional MR machines in some centers. Since MRI was shown to be sensitive and specific for prostate imaging whilst open MR is prohibitive for most centers and makes surgical procedures very complex, this work suggests bringing the MR virtually in the operating room with MRI/TRUS data fusion. This involves providing the physician with bi-modality images (TRUS plus MRI) intended to improve treatment planning from the data registration stage. The pape...

  9. Seed quality in informal seed systems

    NARCIS (Netherlands)

    Biemond, P.C.

    2013-01-01

    Keywords:     informal seed systems, seed recycling, seed quality, germination, seed pathology, seed health, seed-borne diseases, mycotoxigenic fungi, Fusarium verticillioides, mycotoxins, Vigna unguiculata, Zea mays, Nigeria.   Seed is a crucial input for agricultural producti

  10. The development of a human eye model for ophthalmic iodine-125 brachytherapy dosimetry

    International Nuclear Information System (INIS)

    Full text: Radiotherapy is used to treat malign tumors. Radiotherapy is an alternative to enucleation in ocular tumors. However, the irradiation of ocular region can bring damages due high doses, mainly in the crystalline lens and in the bone tissue in growth phase. Brachytherapy instead of teletherapy looks for reducing doses in the crystalline lens and the adjacent tissues of the ocular globe (orbital region), minimizing side effects. Herein, some encapsulated radioisotopes in radioactive seeds applied to the ocular brachytherapy are available. Thus, a three-dimensional computational voxel model of the ocular region with its heterogeneous tissues, globe and adjacent tissues is developed. This computational model is used to simulate orbital irradiation with radioactive seeds positioned on the sclera surface through the MCNP5 code. The computational simulation allows evaluating how doses are spatially distributed in the orbital volume in treatments with the radioactive seeds of iodine-125. Therefore, the results allow comparing the spatial doses distribution obtained through the MCNP5 simulation for those two distinct types of radioactive seeds. Bench markets from literature validates the proposed simulations. (author)

  11. Potential brachytherapy nuclides of future

    International Nuclear Information System (INIS)

    In the past there were relatively few radionuclides available for brachytherapy. But the situation is rapidly changing with the development of many new sources with properties that may be advantageous in certain clinical situations. In the choice of an acceptable, rather than an ideal radionuclide, it is important to consider the physical dose distribution, radiobiological effectiveness, ease of radiation protection, logistics and cost. Taking into account these factors, a number of radionuclides have been tried and more are being considered for specific type of applications. Presently, 137Cs is the most commonly used radionuclide for intracavitary therapy and 192Ir for interstitial therapy. 125I has more or less replaced 198Au for permanent implants. Clinical studies are being carried out to assess the feasibility of replacing 137Cs with 241Am for intracavitary applications and 125I with 103Pd and/or 169Yb for interstitial permanent implants. Other radionuclides being considered are 75Fe and 145Sm. Neutron induced brachytherapy is a new technique being tried to ensure complete radiation safety. (author). 1 tab

  12. 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.

  13. Isodose curve determination of prostate for the treatment of brachytherapy using MCNPX code

    Energy Technology Data Exchange (ETDEWEB)

    Reis Junior, J.P.; Menezes, A.F.; Medeiros, J.A.C.C., E-mail: jjunior@con.ufrj.br, E-mail: ademir@con.ufrj.br, E-mail: amenezes@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ/COPPE/PEN), RJ (Brazil). Coord. dos Programas de Pos-Graduacao em Engenharia. Programa de Engenharia Nuclear; Salmom, H.A., E-mail: heliosalmom@coinet.com.br [MD.X Barra Medical Center, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); Facure, A.N.S.S., E-mail: facure@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Silva, A.X. [Universidade Federal do Rio de Janeiro (UFRJ/DEN), Rio de Janeiro, RJ (Brazil). Escola Politecnica. Dept. de Engenharia Nuclear

    2011-07-01

    Using voxel phantom MAX 06 coupled to the code MCNPX it possible to plot the isodose curves for the main levels involved in the treatment of prostate brachytherapy, V100 and V150 which are, respectively corresponding curves 144 and 216 Gy to curves are indicative of the quality of the existing implant of prostate brachytherapy. The number of 79 seeds {sup 125}I, were placed in the voxels simulator MAX 06, in the slices x = 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 with the calculation model used in MCNPX in all voxels present in a matrix, it was possible to trace the isodose curves for MATLAB. For comparison and using own routines MCNPX it was possible to trace the same curves using mesh tallies. The results showed agreement with predicted values in the planning system prowess 3D. (author)

  14. Study of dose deposition for different configurations of seeds OncoSeed 6711

    International Nuclear Information System (INIS)

    Prostate cancer is the second most common cancer among men. lodine-125 brachytherapy seeds are presented as a form of treatment. In prostate cancer therapy 80-120 iodine-125 seeds are implanted in the organ following a previous planning. During positioning and after it, the implanted seeds can undergo slight displacements relative to the original position. These deviations may cause changes in dose distribution in the tumor volume. This work has made a dosimetry study for iodine-125 seeds used in low dose rate brachytherapy. In the first stage, we performed a one seed dosimetric parameters study following the TG-43 protocol recommendations with the objective of validating our methodology. Then a quantitative study of the variation in dose distribution for three configurations of four seeds OncoSeed 6711 was conducted with two configurations using the seeds in symmetrical positions and the other presenting small displacements. A soft tissue phantom and TLD dosimeters were used. Then a qualitative study of isodose curves of the configurations was performed using radiochromic film, Gafchromic model. This method was used to complement the study of the crystals. The seed's dosimetric parameters obtained in this work showed excellent agreement with the TG-43 consensual values, thus validating the methodology used in this work. The results obtained with radiochromic film and thermoluminescent dosimeters have shown that there is a significant difference in dose distribution when there is a change in the positioning of the seeds. The use of these two methods simultaneously is efficient since the crystals bring a point view and the film has a global view of the dose distribution. (author)

  15. 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, ...

  16. Investigating the dosimetric and tumor control consequences of prostate seed loss and migration

    International Nuclear Information System (INIS)

    Purpose: Low dose-rate brachytherapy is commonly used to treat prostate cancer. However, once implanted, the seeds are vulnerable to loss and movement. The goal of this work is to investigate the dosimetric and radiobiological effects of the types of seed loss and migration commonly seen in prostate brachytherapy. Methods: Five patients were used in this study. For each patient three treatment plans were created using Iodine-125, Palladium-103, and Cesium-131 seeds. The three seeds that were closest to the urethra were identified and modeled as the seeds lost through the urethra. The three seeds closest to the exterior of prostatic capsule were identified and modeled as those lost from the prostate periphery. The seed locations and organ contours were exported from Prowess and used by in-house software to perform the dosimetric and radiobiological evaluation. Seed loss was simulated by simultaneously removing 1, 2, or 3 seeds near the urethra 0, 2, or 4 days after the implant or removing seeds near the exterior of the prostate 14, 21, or 28 days after the implant. Results: Loss of one, two or three seeds through the urethra results in a D90 reduction of 2%, 5%, and 7% loss, respectively. Due to delayed loss of peripheral seeds, the dosimetric effects are less severe than for loss through the urethra. However, while the dose reduction is modest for multiple lost seeds, the reduction in tumor control probability was minimal. Conclusions: The goal of this work was to investigate the dosimetric and radiobiological effects of the types of seed loss and migration commonly seen in prostate brachytherapy. The results presented show that loss of multiple seeds can cause a substantial reduction of D90 coverage. However, for the patients in this study the dose reduction was not seen to reduce tumor control probability.

  17. Computed tomography-guided permanent brachytherapy for locoregional recurrent gastric cancer

    International Nuclear Information System (INIS)

    Locoregional recurrence is the typical pattern of recurrence in gastric cancer, and cannot be removed by surgery in most of the patients. We aimed to evaluate the feasibility and efficacy of computed tomography (CT)-guided brachytherapy for patients with locoregional recurrent gastric cancer. We reviewed the case histories of 28 patients with locoregional recurrent gastric cancer that were selected for CT- guided brachytherapy by a multidisciplinary team. The clinical data of the patients including patient characteristics, treatment parameters, short-term effects, and survival data were collected and analyzed. 15-75 125I seeds were implanted into each patient to produce a minimal peripheral dose (MPD) 100-160 Gy. Median day 0 dosimetry was significant for the following: V100 (the volume treated with the prescription dose) 95.8% (90.2-120.5%) and D90 (prescription dose received by at least 90% of the volume) 105.2% (98.0-124.6%) of prescription dose. No serious complications occurred during the study. Two months after brachytherapy, complete response, partial response and progressive disease were observed in 50.0%, 28.6% and 21.4% of patients, respectively. The median survival time was 22.0 ± 5.2 months, and the 1, 2,and 3-year survival rate was 89 ± 6%, 52 ± 10% and 11 ± 7%, respectively. A univariate analysis showed that the tumor size was a significant predictor of overall survival (P = 0.034). Patients with tumors <3 cm had relatively higher complete response rate (66.7%), compared to those with tumors >3 cm (30.8%). The PTV (planning target volume) smaller than 45 cm3 was significantly correlated with achieving complete tumor eradication in the treated region (P = 0.020). For selected patients with limited locoregional recurrent gastric cancer, CT-guided brachytherapy using 125I seeds implantation can provide a high local control rate, with minimal trauma

  18. The American Brachytherapy Society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

    International Nuclear Information System (INIS)

    Purpose: This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. Methods: Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. Results: The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or

  19. Intraluminal brachytherapy in treatment of malignant obstructive jaundice

    International Nuclear Information System (INIS)

    Objective: To study the practicability and preliminary effect of intraluminal brachytherapy in treatment of malignant obstructive jaundice. Methods: Intraluminal brachytherapy was performed in 4 patients who had been treated with biliary stent implantation. Results: No complications related to intraluminal brachytherapy had happened. One patient was followed up by means of CT, showing reduction in tumor size. Conclusion: Intraluminal brachytherapy is a safe and effective method in treating malignant tumor causing obstructive jaundice

  20. Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate whether the method of applicator reconstruction and/or the applicator orientation influence the dose calculation to points around the applicator for brachytherapy of cervical cancer with CT-based treatment planning. A phantom, containing a fixed ring applicator set and six lead pellets representing dose points, was used. The phantom was CT scanned with the ring applicator at four different angles related to the image plane. In each scan the applicator was reconstructed by three methods: (1) direct reconstruction in each image (DR) (2) reconstruction in multiplanar reconstructed images (MPR) and (3) library plans, using pre-defined applicator geometry (LIB). The doses to the lead pellets were calculated. The relative standard deviation (SD) for all reconstruction methods was less than 3.7% in the dose points. The relative SD for the LIB method was significantly lower (p < 0.05) than for the DR and MPR methods for all but two points. All applicator orientations had similar dose calculation reproducibility. Using library plans for applicator reconstruction gives the most reproducible dose calculation. However, with restrictive guidelines for applicator reconstruction the uncertainties for all methods are low compared to other factors influencing the accuracy of brachytherapy

  1. Brachytherapy next generation: robotic systems.

    Science.gov (United States)

    Popescu, Tiberiu; Kacsó, Alex Cristian; Pisla, Doina; Kacsó, Gabriel

    2015-12-01

    In a field dominated by external beam radiation therapy (EBRT), both the therapeutic and technical possibilities of brachytherapy (BT) are underrated, shadowed by protons and intensity modulated radiotherapy. Decreasing expertise and indications, as well as increasing lack of specific BT training for radiation therapy (RT) residents led to the real need of shortening its learning curve and making it more popular. Developing robotic BT devices can be a way to mitigate the above issues. There are many teams working at custom-made robotic BT platforms to perfect and overcome the limitations of the existing systems. This paper provides a picture of the current state-of-the-art in robotic assisted BT, as it also conveys the author's solution to the problem, a parallel robot that uses CT-guidance. PMID:26816510

  2. Production of 125I from amorphous films of Si doped with 124Xe and evaluation of its potential use in brachytherapy

    International Nuclear Information System (INIS)

    This work describes the simulation of a new material that can be used in the brachytherapy treatment. The material consists of xenon-incorporated amorphous silicon (Xe@a-Si). The irradiated 124Xe atoms of the samples are converted into 125Xe, according to the reaction: 124Xe (n,γ) 125Xe that, in turn, decays to the radioisotope 125I. A set of simulations performed using the MCNP5 code, shows that, in principle, the material proposed can be used in the seed of brachytherapy in the clinical treatment. (author)

  3. Production of {sup 125}I from amorphous films of Si doped with {sup 124}Xe and evaluation of its potential use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Alexandre S., E-mail: asleal@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Viana, Gustavo A., E-mail: gviana@eletronuclear.gov.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin; Siqueira, Paulo T.D.; Saiki, Mitiko, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This work describes the simulation of a new material that can be used in the brachytherapy treatment. The material consists of xenon-incorporated amorphous silicon (Xe@a-Si). The irradiated {sup 124}Xe atoms of the samples are converted into {sup 125}Xe, according to the reaction: {sup 124}Xe (n,γ) {sup 125}Xe that, in turn, decays to the radioisotope {sup 125}I. A set of simulations performed using the MCNP5 code, shows that, in principle, the material proposed can be used in the seed of brachytherapy in the clinical treatment. (author)

  4. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.432 Calibration measurements of brachytherapy sources. (a) Before the first medical use of...

  5. 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 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.406 Brachytherapy sources accountability. (a) A licensee shall maintain accountability at all...

  6. Aktuelle Entwicklungen in der Strahlentherapie des Prostatakarzinoms: HDR-Brachytherapie

    Directory of Open Access Journals (Sweden)

    Knocke-Abulesz TH

    2004-01-01

    Full Text Available In der primären Therapie des Prostatakarzinoms ist die Seed-Implantation neben der radikalen Prostatektomie und der konformalen 3D-geplanten Teletherapie in den letzten Jahren insbesondere bei den lokal begrenzten Tumoren die dritte etablierte Behandlungstechnik geworden. In den USA werden bereits fast ein Drittel der Patienten mit dieser Technik behandelt. Im Gegensatz hierzu wurde in der Strahlentherapie in den letzten beiden Jahrzehnten die Langzeit-Implantation von Nukliden bei den meisten Tumoren zugunsten der fraktionierten Afterloading-Bestrahlung in "high dose rate" (HDR- Technik ersetzt – wobei partiell für HNO- und gynäkologische Tumoren die HDR-Technik als "pulse-dose-rate" (PDR- Verfahren modifiziert wird, um die biologischen Vorteile der LDR- und die technologischen Vorteile der HDR-Anwendung zu vereinen. Vorteile der Methode im Vergleich zur Seed-Implantation sind: – Niedrigere Kosten, allgemeine Verfügbarkeit, – Idealer Strahlenschutz, – Zuverlässige Dosisverteilung, – Keine Migration von Seeds, – Durchführbar auch nach TURP, – Durchführbar bei manifesten Lokalrezidiven. Allerdings liegen bisher nur vereinzelte klinische Ergebnisse beim Prostatakarzinom vor, die zeigen, daß eine lokale Dosiserhöhung in Kombination mit der Teletherapie eine Verbesserung der lokalen Kontrolle bei kapselüberschreitenden Tumoren ermöglicht. Inwieweit der Einsatz der Technik bei Lokalrezidiven zu langandauernden Remissionen führen kann, ist Gegenstand von laufenden Untersuchungen. Der Ersatz der Seed-Implantation durch eine 2-tägige fraktionierte Brachytherapie mit vier Bestrahlungen ist derzeit Gegenstand einer prospektiven Studie, deren erste Langzeitergebnisse in diesem Jahr erwartet werden.

  7. Iodine-125 seeds for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Feher, Anselmo; Moura, Joao A.; Moura, Eduardo S.; Nagatomi, Helio R.; Manzoli, Jose E.; Souza, Carla D., E-mail: elisaros@ipen.b, E-mail: czeituni@pobox.co, E-mail: afeher@ipen.b, E-mail: jmoura31@yahoo.com.b, E-mail: esmoura@ipen.b, E-mail: hrnagato@ipen.b, E-mail: jemanzoli@ipen.b, E-mail: cdsouza@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Karam, Dib, E-mail: dib.karan@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Escola de Artes, Ciencias e Humanidades

    2009-07-01

    In Brazil, cancer has become one of the major public health problems. An estimate by the Health Ministry showed that 466,430 people had the disease in the country in 2008. The prostate cancer is the second largest death cause among men. The National Institute of Cancer estimated the occurrence of 50,000 new cases for 2009. Some of these patients are treated with Brachytherapy, using Iodine-125 seeds. By this technique, small seeds with Iodine-125, a radioactive material, are implanted in the prostate. The advantages of radioactive seed implants are the preservation of healthy tissues and organs near the prostate, besides the low rate of impotence and urinary incontinence. The Energy and Nuclear Research Institute - IPEN, which belongs to the Nuclear Energy National Commission - CNEN, established a program for the development of the technique and production of Iodine-125 seeds in Brazil. The estimate for the 125-Iodine seeds demand is of 8,000 seeds/month and the laboratory to be implanted will need this production capacity. The purpose of this paper is to explain the project status and show some data about the seeds used in the country. The project will be divided in two phases: technological development of a prototype and a laboratory implementation for the seeds production. (author)

  8. Iodine-125 seeds for cancer treatment

    International Nuclear Information System (INIS)

    In Brazil, cancer has become one of the major public health problems. An estimate by the Health Ministry showed that 466,430 people had the disease in the country in 2008. The prostate cancer is the second largest death cause among men. The National Institute of Cancer estimated the occurrence of 50,000 new cases for 2009. Some of these patients are treated with Brachytherapy, using Iodine-125 seeds. By this technique, small seeds with Iodine-125, a radioactive material, are implanted in the prostate. The advantages of radioactive seed implants are the preservation of healthy tissues and organs near the prostate, besides the low rate of impotence and urinary incontinence. The Energy and Nuclear Research Institute - IPEN, which belongs to the Nuclear Energy National Commission - CNEN, established a program for the development of the technique and production of Iodine-125 seeds in Brazil. The estimate for the 125-Iodine seeds demand is of 8,000 seeds/month and the laboratory to be implanted will need this production capacity. The purpose of this paper is to explain the project status and show some data about the seeds used in the country. The project will be divided in two phases: technological development of a prototype and a laboratory implementation for the seeds production. (author)

  9. Treatment of localized prostate cancer with brachytherapy: six years experience

    International Nuclear Information System (INIS)

    The usage of ultrasound scan to perform prostate biopsy punctures, the new radiation therapies and the more accurate selection of patients has allowed brachytherapy to play an important role in the treatment of the localized pathology. The objective of this paper is to review the results obtained when treating the localized prostate cancer by using brachytherapy with mud 125. Materials and methods: Between December 1999 and July 2006, 100 prostate cancer patients were treated at the Hospital Italiano de Buenos Aires, using brachytherapy with mud 125. One of the patients was treated with a combined therapy (brachytherapy + external radiotherapy). For that reason, the patient was not taken into consideration for this paper. The average age was 65.95 (52-79). The tumoral stages were T1c in 81% of the patients and T2a in 19% of them. The PSA was always below 15 ng/ml, with an average of 8.92 ng/ml; inferior to 10 ng/ml in 72 patients and between 10 and 15 ng/m ml in 28 of them. The average prostate volume was 34.68 c.c. (18.70 c.c.-58.00 c.c.). The combined Gleason score was below 6 (except for three patients with Gleason 7 who had a PSA below 10, stage T1c). The dose used was 16,000 cGy as recommended by the TG43. The energy charge of each seed was between 0.28 and 0.40 mci. Thirty days later, a prostate axial computer tomography was carried out every 3 mm. with a scanning set every 5 mm. to perform a dosimetric control of the implant. Results: The average age was 65.95 (52-79). The control computer tomography showed an adequate dosimetric coverage for the entire prostate volume, with a maximum urethral dose not above 400 Gy and a maximum rectal dose below 100 Gy. The PSA of all patients decreased to a normal level 6 months after the treatment started. The average follow-up of the 71 patients able to be tested from an oncological perspective lasted 31.15 months, with a minimum of 18 and a maximum of 72 months. Currently, seven patients of those tested (9.86%) manifest

  10. Risk factors for acute urinary retention requiring temporary intermittent catheterization after prostate brachytherapy: a prospective study

    International Nuclear Information System (INIS)

    Purpose: We prospectively investigated prognostic factors for men undergoing transperineal radioactive seed implantation for prostate cancer at the University of Washington. Methods and Materials: Between February and April, 1998, 62 consecutive unselected patients were prospectively followed after brachytherapy for early-stage prostate adenocarcinoma. Pretreatment variables included age, American Urological Association (AUA) score, uroflowimetry, and prostate volume by ultrasound. Nonrandomized variables included hormonal therapy, seed type, and use of pelvic radiotherapy. Patients were contacted by phone at one week postoperatively and at one-month intervals thereafter. Follow-up continued until all patients provided the date of last catheterization. Results: Urinary retention rate at one week was 34% (21 of 63 patients). At one month, 29%; at three months, 18%; and at six months, 10%. Preoperative flow rate and post-void residual did not predict for retention (p=.48 and p=.58). Use of alpha blockers, hormonal therapy, type of seed (103Pd or 1251), or external beam radiotherapy had no impact on risk of retention at any followup point. Preimplant volume and AUA score predicted for retention on univariate analysis, but on multivariate analysis only postimplant volume remained significant (p=.02) for predicting retention risk and duration. Conclusion: Patients with large prostate size (>36 g) and higher AUA score (>10) appear to be at greater risk of risk of retention as well as duration of retention as defined in our study. Further investigation will be needed to clarify the risk of urinary retention for men undergoing brachytherapy

  11. Postenucleation orbits in retinoblastoma: treatment with 125I brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Children with retinoblastoma that extends into or through the choroid, sclera, or optic nerve are at risk of developing orbital disease, as well as metastases. Previously, these enucleated orbits were treated with external beam radiotherapy in addition to chemotherapy. 125I brachytherapy for tumors in and around the eye was pioneered by Sealy in Cape Town, South Africa, in 1974. In 1983, he developed a technique to irradiate the contents of the orbit while limiting the dose to the bony orbit and eyelids. Methods and Materials: Six nylon tubes containing 125I seeds were implanted through the eyelids around the periphery of the orbit. Each contained a metal gutter that screens the outer part of the seeds from the bony orbit. A seventh unscreened tube was placed in the center, and a metal disc with 125I seeds on its posterior surface was secured beneath the eyelids. Between 1983 and 2000, 57 orbits were treated in 56 children with retinoblastoma. Thirty-six were treated prophylactically and 21, with tumor at the resection line of the nerve, extrascleral tumor, or metastases, were treated therapeutically. They received a median dose of 34 Gy in 70 h; 30 also received chemotherapy. Children with tumor at the resection line of the nerve also received treatment to the craniospinal axis. Results: The median follow-up of the 35 patients treated prophylactically was 35 months (range 0-187). Seven patients died, 6 of metastases, at a median of 10 months (range 4-29) after the implant. Eight of the 13 patients with microscopic extraocular tumor survived a median of 29 months (range 5-156). None of the 8 patients presenting with orbital tumor or metastases survived. No orbital recurrences developed in any of the patients. Cosmesis was considerably improved compared with previous forms of irradiation. Conclusion: Orbital brachytherapy is an effective method of irradiating the orbit to prevent recurrent tumor, the treatment time is short, and the cosmesis is much more

  12. Study of isodose curves of an eye brachytherapy plaque

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Marcos R.O.; Mourao, Arnaldo P., E-mail: marcos.robertto@hotmail.com, E-mail: seg@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Grynberg, Suely E., E-mail: aprata@des.cefetmg.br [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar

    2015-07-01

    The use eye plaque brachytherapy for intraocular tumors treatment is a process designed to protect healthy eye structures, as well as visual functions. It replaces enucleation when possible. The knowledge of the dose spatial distribution inside the eyeball and adjacent structures is very important to obtain the therapeutic dose, minimize the side effects and ensure efficiency in the process. Small variations in positioning the plaque on the ocular surface may generate a less effective treatment. Thus, in this work an eyeball phantom and a seed accommodation system similar to a commercially eye plaque model ROPES with diameter of 15 mm, were developed both in solid water Gammex 457 to conduct the study of the possible variation in the dose deposition inside the eye phantom. Radiochromic films were used to record isodose curves of two orthogonal plans within the simulator. The results showed that there is a difference in the dose deposition for the two orthogonal plans studied. This difference is 8.33% higher for the maximum dose value. Thus, a difference in dose that occurs due to the asymmetrical distribution of seeds on the eye plaque may interfere with the treatment, making it less effective. (author)

  13. Design of an ultrasound-guided robotic brachytherapy needle insertion system

    CERN Document Server

    Hungr, Nikolai; Zemiti, Nabil; Tripodi, Nathanael

    2009-01-01

    In this paper we describe a new robotic brachytherapy needle-insertion system that is designed to replace the template used in the manual technique. After a brief review of existing robotic systems, we describe the requirements that we based our design upon. A detailed description of the proposed system follows. Our design is capable of positioning and inclining a needle within the same workspace as the manual template. To help improve accuracy, the needle can be rotated about its axis during insertion into the prostate. The system can be mounted on existing steppers and also easily accommodates existing seed dispensers, such as the Mick Applicator.

  14. ACPSEM brachytherapy working group recommendations for quality assurance in brachytherapy

    International Nuclear Information System (INIS)

    The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) Radiation Oncology Specialty Group (ROSG) formed a series of working groups in 2011 to develop recommendation papers for guidance of radiation oncology medical physics practice within the Australasian setting. These recommendations are intended to provide guidance for safe work practices and a suitable level of quality control without detailed work instructions. It is the responsibility of the medical physicist to ensure that locally available equipment and procedures are sufficiently sensitive to establish compliance to these recommendations. The recommendations are endorsed by the ROSG, have been subject to independent expert reviews and have also been approved by the ACPSEM Council. For the Australian audience, these recommendations should be read in conjunction with the Tripartite Radiation Oncology Practice Standards. This publication presents the recommendations of the ACPSEM Brachytherapy Working Group (BTWG) and has been developed in alignment with other international associations. However, these recommendations should be read in conjunction with relevant national, state or territory legislation and local requirements, which take precedence over the ACPSEM recommendation papers. It is hoped that the users of this and other ACPSEM recommendation papers will contribute to the development of future versions through the Radiation Oncology Specialty Group of the ACPSEM.

  15. Local anesthesia for prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To demonstrate the technique and feasibility of prostate brachytherapy performed with local anesthesia only. Methods and Materials: A 5 by 5 cm patch of perineal skin and subcutaneous tissue is anesthetized by local infiltration of 10 cc of 1% lidocaine with epinephrine, using a 25-gauge 5/8-inch needle. Immediately following injection into the subcutaneous tissues, the deeper tissues, including the pelvic floor and prostate apex, are anesthetized by injecting 15 cc lidocaine solution with approximately 8 passes of a 20-gauge 1.0-inch needle. Following subcutaneous and peri-apical lidocaine injections, the patient is brought to the simulator suite and placed in leg stirrups. The transrectal ultrasound (TRUS) probe is positioned to reproduce the planning images and a 3.5- or 6.0-inch, 22-gauge spinal needle is inserted into the peripheral planned needle tracks, monitored by TRUS. When the tips of the needles reach the prostatic base, about 1 cc of lidocaine solution is injected in the intraprostatic track, as the needle is slowly withdrawn, for a total volume of 15 cc. The implants are done with a Mick Applicator, inserting and loading groups of two to four needles, so that a maximum of only about four needles are in the patient at any one time. During the implant procedure, an additional 1 cc of lidocaine solution is injected into one or more needle tracks if the patient experiences substantial discomfort. The total dose of lidocaine is generally limited to 500 mg (50 ml of 1% solution). Results: To date, we have implanted approximately 50 patients in our simulator suite, using local anesthesia. Patients' heart rate and diastolic blood pressure usually showed moderate changes, consistent with some discomfort. The time from first subcutaneous injection and completion of the source insertion ranged from 35 to 90 minutes. Serum lidocaine levels were below or at the low range of therapeutic. There has been only one instance of acute urinary retention in the

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

    International Nuclear Information System (INIS)

    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)

  17. 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)

  18. The brachytherapy with low dose-rate iridium for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Momma, Tetsuo; Saito, Shiro; Ohki, Takahiro; Satoh, Hiroyuki; Toya, Kazuhito; Dokiya, Takushi [National Tokyo Medical Center (Japan); Murai, Masaru

    2000-11-01

    Brachytherapy as an option for the treatment of prostate cancer has been commonly performed in USA. As the permanent seeding of the radioactive materials is strictly restricted by the law in Japan, brachytherapy must be performed by the temporary implant. This treatment has been performed at a few facilities in Japan mostly using high dose-rate iridium. Only our facility has been using low dose-rate iridium (LDR-Ir) for prostate cancer. This study evaluates the clinical results of the treatment. Since December 1997 to December 1999, 26 patients with histologically diagnosed as prostate cancer (Stage B, 92%; Stage C, 8%) underwent brachytherapy. Twenty-two patients received brachytherapy alone, three were treated with a combination of brachytherapy and external beam radiotherapy (ERT) and one was treated with a combination of brachytherapy and neoadjuvant endocrine therapy. Patients ranged in age from 61 to 84 (median 76) years old. Treatment was initiated with perineal needle placement. From 10 to 14 needles were placed through the holes on the template which was fixed to the stabilizer of the transrectal ultrasound probe. After the needle placement, CT scan was performed to draw distribution curves for the treatment planning. LDR-Ir wires were introduced to the sheath and indwelled during the time calculated from dosimetry. Peripheral dose was 70 Gy for the monotherapy of brachytherapy. For the combination therapy, 40 Gy was given by brachytherapy and 36 Gy with ERT afterwards. LDR-Ir wires were removed after completion of the radiation and patients were followed with serum PSA level and annual biopsy. During 2 to 26 (median 12) months follow-up, 8 out of 9 patients with initial PSA level above 20 ng/ml showed PSA failure. All 13 patients with initial PSA level lower than 20 ng/ml were free from PSA failure. Eight out of 11 patients with Gleason's score 7 or higher showed PSA failure, and all 14 patients (including three patients with combined therapy) with

  19. Novel high resolution 125I brachytherapy source dosimetry using Ge-doped optical fibres

    International Nuclear Information System (INIS)

    The steep dose gradients close to brachytherapy sources limit the ability to obtain accurate measurements of dose. Here we use a novel high spatial resolution dosimeter to measure dose around a 125I source and compare against simulations. Ge-doped optical fibres, used as thermoluminescent dosimeters, offer sub-mm spatial resolution, linear response from 10 cGy to >1 kGy and dose-rate independence. For a 125I brachytherapy seed in a PMMA phantom, doses were obtained for source-dosimeter separations from 0.1 cm up to several cm, supported by EGSnrc/DOSRZznrc Monte Carlo simulations and treatment planning system data. The measurements agree with simulations to within 2.3%±0.3% along the transverse and perpendicular axes and within 3.0%±0.5% for measurements investigating anisotropy in angular dose distribution. Measured and Veriseed™ brachytherapy treatment planning system (TPS) values agreed to within 2.7%±0.5%. Ge-doped optical fibre dosimeters allow detailed dose mapping around brachytherapy sources, not least in situations of high dose gradient. - Highlights: • We evaluate fall-off in dose for distances from an 125I source of 1 mm to 60 mm. • The TL of optical fibres accommodate high dose gradients and doses that reduce by a factor of 103 across the range of separations. • We verify measured values using DOSRZnrc Monte Carlo code simulations and the Variseed™ Treatment Planning System. • Measured radial and angular dose are obtained with ≤3% uncertainty

  20. 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

    2015-01-01

    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.  PMID:25679174

  1. Brachytherapy on treatment of childhood rhabdomyosarcoma

    International Nuclear Information System (INIS)

    A retrospective study of 21 children with rhabdomyosarcoma treated by brachytherapy to the primary site of the tumor between january/1980 to june/1993 was undertaken. The main objectives were: to comprove the utility of brachytherapy in childhood rhabdomyosarcoma, to evaluate the local control and survival in association with chemotherapy, to analyze the late effects of the treatment and to determinate the preferencial technique to each clinical situation. Seventeen patients were female and four male with a median age of five years (range of 3 months to 15 years). Seven children showed head and neck tumors, seven in extremities, five genital, one perineal and one in trunk. Four patients were group II, fifteen group III and two group IV according the Intergroup Rhabdomyosarcoma Study (IRS) classification. The histologic type presented eighteen embryonary rhabdomyosarcoma, one alveolar rhabdomyosarcoma and in two patients was not possible to be determined. The therapeutic approach included induction chemotherapy followed by radiotherapy to the primary site in association or not with surgical ressection and maintenance chemotherapy. All patients received brachytherapy to the tumor site. The radioactive isotopes employed were: Gold198, Cesium137 and Iridium192. The brachytherapy techniques depended on the tumor site, period of treatment, availability of the radioactive material and stage of the disease. Patients treated exclusively by brachytherapy received 40Gy to 60Gy. When brachytherapy was associated with external radiotherapy the dose ranged from 20Gy to 40Gy. Local control was achieved in 18 of 20 patients (90%). The global survival and local control survival rates were 61.9% ((13(21)) patients) and 72.2% ((13(18)) patients) respectively. Staging and age showed statistic significance for survival. Distant metastasis occurred in seven patients (33.3%), mainly to the lungs. Patients treated with total radiation dose higher than 45Gy showed more incidence of

  2. Dosimetric calculus in intravascular brachytherapy

    International Nuclear Information System (INIS)

    Among the cardiovascular diseases, the most common is acute myocardial infarction, which occurs because of the occlusion of one or more coronary arteries. Balloon angioplasty has been a popular treatment which is less invasive than 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). 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 order to study the radiation dosimetry in the patient and radiological protection for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, 0.30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several radionuclides. Two stent sources employing 32P are also simulated. Advantages and disadvantages of the radionuclides and source geometries are discussed and the dosimetry developed here will aid in the realization of the benefits obtained in patients. (author)

  3. Seed proteomics

    Science.gov (United States)

    Seeds comprise a protective covering, a small embryonic plant, and a nutrient-storage organ. Seeds are protein-rich, and have been the subject of many mass spectrometry-based analyses. Seed storage proteins (SSP), which are transient depots for reduced nitrogen, have been studied for decades by cel...

  4. Physics and quality assurance of low dose rate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: The purpose of this course is to review the physical principles underlying design, clinical application and execution of interstitial and intracavitary implants in the classical low dose-rate (LDR) range. This year, the course will focus on quality assurance of sources, applicators and treatment planning software. In addition, development of procedures and QA checks designed optimize treatment delivery accuracy and patient safety during each individual procedure will be reviewed. The level of presentation will be designed to accommodate both physicists and physicians. Implementation of recently published AAPM Task Group reports (no. 40, 'Comprehensive Quality Assurance' and No. 43, 'Dosimetry of Interstitial Brachytherapy Sources') will be reviewed. Outline: (A) General Principles (1) QA endpoints: temporal accuracy, positional accuracy, dose delivery accuracy, and safety of the patient, personnel, and the institution (2) QA procedure development: forms, checklists, test development and design of treatment delivery procedures (B) QA of treatment delivery devices (1) Source acceptance testing and QA a) calibration and source strength specification standards b) leakage tests and source geometry verification (2) Applicator acceptance testing and QA (3) Remote afterloading devices (4) Treatment planning systems a) graphic input/output devices, implant geometry reconstruction, and graphical display b) dose calculation accuracy i) review of brachytherapy dose calculation algorithms ii) dosimetric benchmarks available: Task Group 43 report (C) Procedure-specific QA 1) Organization of treatment delivery team 2) Preplanning and preparation 3) Applicator insertion 4) Radiographic examination of the implant, prescription, and treatment calculation 5) Source insertion 6) Treatment planning and physicist review of treatment plans 7) QA during patient treatment and removal of sources and applicators

  5. Peripheral nerve reconstruction with epsilon-caprolactone conduits seeded with vasoactive intestinal peptide gene-transfected mesenchymal stem cells in a rat model

    Science.gov (United States)

    Hernández-Cortés, P.; Toledo-Romero, M. A.; Delgado, M.; Sánchez-González, C. E.; Martin, F.; Galindo-Moreno, P.; O'Valle, F.

    2014-08-01

    Objective. Attempts have been made to improve nerve conduits in peripheral nerve reconstruction. We investigated the potential therapeutic effect of a vasoactive intestinal peptide (VIP), a neuropeptide with neuroprotective, trophic and developmental regulatory actions, in peripheral nerve regeneration in a severe model of nerve injury that was repaired with nerve conduits. Approach. The sciatic nerve of each male Wistar rat was transected unilaterally at 10 mm and then repaired with Dl-lactic-ɛ-caprolactone conduits. The rats were treated locally with saline, with the VIP, with adipose-derived mesenchymal stem cells (ASCs) or with ASCs that were transduced with the VIP-expressing lentivirus. The rats with the transected nerve, with no repairs, were used as untreated controls. At 12 weeks post-surgery, we assessed their limb function by measuring the ankle stance angle and the percentage of their muscle mass reduction, and we evaluated the histopathology, immunohistochemistry and morphometry of the myelinated fibers. Main results. The rats that received a single injection of VIP-expressing ASCs showed a significant functional recovery in the ankle stance angle (p = 0.049) and a higher number of myelinated fibers in the middle and distal segments of the operated nerve versus the other groups (p = 0.046). Significance. These results suggest that utilization of a cellular substrate, plus a VIP source, is a promising method for enhancing nerve regeneration using Dl-lactic-ɛ-caprolactone conduits and that this method represents a potential useful clinical approach to repairing peripheral nerve damage.

  6. High beta and electron dose from 192Ir: implications for 'gamma' intravascular brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Trains of multiple 192Ir seeds are used in many clinical trials for intravascular brachytherapy. 192Ir source is commonly considered as a gamma emitter, despite the understanding that this radionuclide also emits a wide range of electron and beta energies, with a similar range of energy. The high dose from betas and electrons in the submillimeter range due to unsealed ends of seed sources should be precisely quantified to fully understand the backdrop for complications associated with 192Ir coronary artery brachytherapy. Methods and Materials: Monte Carlo simulations (MCNP4C code) were performed for a model 5-seed 192Ir train used in SCRIPPS, GAMMA, and the Washington Radiation for In-Stent Restenosis (WRIST) randomized clinical trials. A stack of radiochromic films was also used to measure the dose distributions for an actual 6-seed train. Results: In the submillimeter range very close to the source, Monte Carlo results show that betas and electrons deposit a higher dose than 192Ir photons (gamma and X-rays) over the interseed gap. A high luminal dose from the combined effects of betas, electrons, and photons emitted from 192Ir can be deposited, particularly between seeds. When prescribing 15 Gy at 2 mm, the combined dose can be as high as 160 Gy at 0.5 mm. Different peak doses near the interseed gaps were noted, which may be due to variability of seed-end surfaces and nonuniformity of seed activity within a real multiseed train. Dose-volume histograms (DVH) of lumen surfaces were evaluated for an eccentric seed train. The DVH parameters indicating the extent of hot spots in the lumen wall, DV10, DV5, DV2, and DV1 (dose received by 10, 5, 2, 1% respectively of the total lumen surface), can be as high as 55, 76, 81, and 155 Gy for a lumen with 3-mm diameter, and 75, 80, 110, and 158 Gy for a narrow 2-mm lumen. Conclusion: 192Ir multiple seed trains used in the SCRIPPS, GAMMA, and WRIST trials can deposit a very high dose to the luminal wall. A particularly

  7. A multicentre ‘end to end’ dosimetry audit for cervix HDR brachytherapy treatment

    International Nuclear Information System (INIS)

    Purpose: To undertake the first multicentre fully ‘end to end’ dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures. Materials and methods: A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems. Deviations between plan and measurement were quantified at prescription Point A and using gamma analysis. Local procedures were also discussed. Results: The mean difference between planned and measured dose at Point A was −0.6% for plastic applicators and −3.0% for metal applicators, at standard uncertainty 3.0% (k = 1). Isodose distributions agreed within 1 mm over a dose range 2–16 Gy. Mean gamma passing rates exceeded 97% for plastic and metal applicators at 3% (local) 2 mm criteria. Two errors were found: one dose normalisation error and one applicator library misaligned with the imaged applicator. Suggestions for quality improvement were also made. Conclusions: The concept of ‘end to end’ dosimetry audit for HDR brachytherapy has been successfully implemented in a multicentre environment, providing evidence that a high level of accuracy in brachytherapy dosimetry can be achieved

  8. 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)

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

    International Nuclear Information System (INIS)

    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)

  10. Sensitivity of low energy brachytherapy Monte Carlo dose calculations to uncertainties in human tissue composition

    International Nuclear Information System (INIS)

    Purpose: The objective of this work is to assess the sensitivity of Monte Carlo (MC) dose calculations to uncertainties in human tissue composition for a range of low photon energy brachytherapy sources: 125I, 103Pd, 131Cs, and an electronic brachytherapy source (EBS). The low energy photons emitted by these sources make the dosimetry sensitive to variations in tissue atomic number due to the dominance of the photoelectric effect. This work reports dose to a small mass of water in medium Dw,m as opposed to dose to a small mass of medium in medium Dm,m. Methods: Mean adipose, mammary gland, and breast tissues (as uniform mixture of the aforementioned tissues) are investigated as well as compositions corresponding to one standard deviation from the mean. Prostate mean compositions from three different literature sources are also investigated. Three sets of MC simulations are performed with the GEANT4 code: (1) Dose calculations for idealized TG-43-like spherical geometries using point sources. Radial dose profiles obtained in different media are compared to assess the influence of compositional uncertainties. (2) Dose calculations for four clinical prostate LDR brachytherapy permanent seed implants using 125I seeds (Model 2301, Best Medical, Springfield, VA). The effect of varying the prostate composition in the planning target volume (PTV) is investigated by comparing PTV D90 values. (3) Dose calculations for four clinical breast LDR brachytherapy permanent seed implants using 103Pd seeds (Model 2335, Best Medical). The effects of varying the adipose/gland ratio in the PTV and of varying the elemental composition of adipose and gland within one standard deviation of the assumed mean composition are investigated by comparing PTV D90 values. For (2) and (3), the influence of using the mass density from CT scans instead of unit mass density is also assessed. Results: Results from simulation (1) show that variations in the mean compositions of tissues affect low energy

  11. Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants

    International Nuclear Information System (INIS)

    Full text of publication follows: Introduction: In this study we present dose measurements for professionals exposed during interstitial 125 I permanent prostate brachytherapy implants. Methods and Materials: The implant technique used was intra operative real time using strand and loose seeds. The professionals inside the operating room are an oncologist, a radiologist, a physicist, a nurse and an anesthesiologist. The oncologist and the physicist contact directly the loaded needle with radioactive seeds and two types of measurements were taken: total body and extremities (finger) dose. The rest of the team operates at long distances, but measurements were made. To measure total body equivalent dose we use a Berthold Umo LB 123 coupled with a LB 1236-H10 detector, and we recorded dose, time and distance from implant location. Finger dosemeters are thermo -luminescent dosimeter (TLD) rings that were controlled over one month. Results: 50 cases (average number of applications per year) were analysed for extremities measurements and 9 cases for total body measurements (in this case, the results were extrapolated for 50 cases), with an average of 26.1 mCi total activity per implant (in a range of 17.4 - 40.3 mCi). The finger dose was 1.8 mSv for the oncologist and 1.9 mSv for the physicist. The interpolation of total body equivalent dose for the oncologist was 24 mSv, for the radiologist 6 mSv and 9 mSv for the physicist. The rest of the team did not receive anything but background radiation. The annual national limit dose for workers is 20 mSv for total body irradiation, and 500 mSv for extremities. Conclusion: In conclusion we may say that during interstitial permanent prostate brachytherapy implants, total doses received for all groups are not significant when compared to annual limits for Portuguese laws 1. Even so, our main goal is always to get the less possible dose (ALARA principle). References: 1. Decreto Lei n. 180/2002 de 8 de Agosto. (authors)

  12. Seed quality in informal seed systems

    OpenAIRE

    Biemond, P.C.

    2013-01-01

    Keywords:     informal seed systems, seed recycling, seed quality, germination, seed pathology, seed health, seed-borne diseases, mycotoxigenic fungi, Fusarium verticillioides, mycotoxins, Vigna unguiculata, Zea mays, Nigeria.   Seed is a crucial input for agricultural production. Approximately 80% of the smallholder farmers in Africa depend for their seed on the informal seed system, consisting of farmers involved in selection, production and dissemination of seed. The la...

  13. SU-E-T-366: Clinical Implementation of MR-Guided Vaginal Cylinder Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To evaluate the accuracy of MR-based vaginal brachytherapy source localization using an in-house MR-visible marker versus the alignment of an applicator model to MR images. Methods: Three consecutive patients undergoing vaginal HDR brachytherapy with a plastic cylinder were scanned with both CT and MRI (including T1- and T2- weighted images). An MR-visible source localization marker, consisting of a sealed thin catheter filled with either water (for T2 contrast) or Gd-doped water (for T1 contrast), was assembled shortly before scanning. Clinically, the applicator channel was digitized on CT with an x-ray marker. To evaluate the efficacy of MR-based applicator reconstruction, each MR image volume was aligned locally to the CT images based on the region containing the cylinder. Applicator digitization was performed on the MR images using (1) the MR visible marker and (2) alignment of an applicator surface model from Varian's Brachytherapy Planning software to the MRI images. Resulting source positions were compared with the original CT digitization. Results: Although the source path was visualized by the MR marker, the applicator tip proved difficult to identify due to challenges in achieving a watertight seal. This resulted in observed displacements of the catheter tip, at times >1cm. Deviations between the central source positions identified via aligning the applicator surface model to MR and using the xray marker on CT ranged from 0.07 – 0.19 cm and 0.07 – 0.20 cm on T1- weighted and T2-weighted images, respectively. Conclusion: Based on the current study, aligning the applicator model to MRI provides a practical, current approach to perform MR-based brachytherapy planning. Further study is needed to produce catheters with reliably and reproducibly identifiable tips. Attempts are being made to improve catheter seals, as well as to increase the viscosity of the contrast material to decrease fluid mobility inside the catheter

  14. The case for focal brachytherapy for the management of low grade prostate cancer

    International Nuclear Information System (INIS)

    Full text: Radical therapy of low to intermediate prostate cancer patients can cause substantial adverse events relating to genitourinary and rectal toxicity. Yet there is little evidence that such treatment results in increased life expectancy. On the other hand, watchful waiting is associated with active surveillance and the patient must accept that the cancer remains untreated and has a risk of progression. Focal therapy of low grade prostate cancer provides an intermediate approach to the management of this cancer. The approach is to treat only those positive segments on biopsy and so reduce the likelihood of adverse events. However, continued surveillance is required because of the increased risk of disease progression. Focal therapy needs to be evaluated using available ablative therapies. Recent studies of focal HIFU for 20 patients showed PSA reduced from 7.3 to 1.5 ng/mL at 12 months. 1/20 patients had inadequate erections and 2120 required pads. 17/19 had no histological evidence of cancer and none had evidence of high volume or Gleason = 7 cancer in the treated lobe. Seed brachytherapy is commonly used for radical prostate treatment of low volume disease. As the same template can be used for seed therapy as is used for biopsy, the technique is ideally suited for focal brachytherapy. As any treatment involving less than the entire gland involves the risk of leaving viable cancer cells outside the treatment zone, a phase 3 randomised clinical trial between radical and focal brachytherapy is advocated to demonstrate the efficacy and safety of the latter relative to radical therapy.

  15. A Phase III Randomized Trial of the Timing of Meloxicam With Iodine-125 Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Nonsteroidal anti-inflammatory medication is used to reduce prostate edema and urinary symptoms following prostate brachytherapy. We hypothesized that a cyclooxygenase-2 (COX-2) inhibitor regimen started 1 week prior to seed implant might diminish the inflammatory response, thus reducing edema, retention rates, and symptom severity. Methods and Materials: From March 2004 to February 2008, 316 men consented to an institutional review board-approved randomized study of a 4-week course of meloxicam, 7.5 mg orally twice per day, starting either on the day of implant or 1 week prior to implant. Brachytherapy was performed using iodine-125 seeds and was preplanned and performed under transrectal ultrasound (TRUS) and fluoroscopic guidance. Prostate volume obtained by MR imaging at 1 month was compared to baseline prostate volume obtained by TRUS planimetry and expressed as an edema factor. The trial endpoints were prostate edema at 1 month, International Prostate Symptom Score (IPSS) questionnaire results at 1 and 3 months, and any need for catheterization. Results: Results for 300 men were analyzed. Median age was 61 (range, 45-79 years), and median TRUS prostate volume was 35.7 cc (range, 18.1-69.5 cc). Median IPSS at baseline was 5 (range, 0-24) and was 15 at 1 month, 16 at 3 months, and 10 at 6 months. Catheterization was required for 7% of patients (6.2% day 0 arm vs. 7.9% day -7 arm; p = 0.65). The median edema factor at 1 month was 1.02 (range, 0.73-1.7). 1.01 day 0 arm vs. 1.05 day -7 arm. Baseline prostate volume remained the primary predictor of postimplant urinary retention. Conclusions: Starting meloxicam 1 week prior to brachytherapy compared to starting immediately after the procedure did not reduce 1-month edema, improve IPSSs at 1 or 3 months, or reduce the need for catheterization.

  16. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

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

    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...

  17. Dose calculation in brachytherapy with microcomputers

    International Nuclear Information System (INIS)

    The computer algorithms, that allow the calculation of brachytherapy doses and its graphic representation for implants, using programs developed for Pc microcomputers are presented. These algorithms allow to localized the sources in space, from their projection in radiographics images and trace isodose counter. (C.G.C.)

  18. Dosimetry on ocular brachytherapy with ROPE plaque with iodine125 and palladium-103

    International Nuclear Information System (INIS)

    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 departing 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 model of ocular area was developed to simulate orbital irradiation with ROPES ophthalmologic plaque placed on the sclera surface filled to ten iodine-125 seeds, and palladium-103 seeds. 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 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. (author)

  19. Effects of insertion speed and trocar stiffness on the accuracy of needle position for brachytherapy

    International Nuclear Information System (INIS)

    Purpose: In prostate brachytherapy, accurate positioning of the needle tip to place radioactive seeds at its target site is critical for successful radiation treatment. During the procedure, needle deflection leads to seed misplacement and suboptimal radiation dose to cancerous cells. In practice, radiation oncologists commonly use high-speed hand needle insertion to minimize displacement of the prostate as well as the needle deflection. Effects of speed during needle insertion and stiffness of trocar (a solid rod inside the hollow cannula) on needle deflection are studied. Methods: Needle insertion experiments into phantom were performed using a 22 factorial design (2 parameters at 2 levels), with each condition having replicates. Analysis of the deflection data included calculating the average, standard deviation, and analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: The stiffer tungsten carbide trocar is effective in reducing the average and standard deviation of needle deflection. The fast insertion speed together with the stiffer trocar generated the smallest average and standard deviation for needle deflection for almost all cases. Conclusions: The combination of stiff tungsten carbide trocar and fast needle insertion speed are important to decreasing needle deflection. The knowledge gained from this study can be used to improve the accuracy of needle insertion during brachytherapy procedures.

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

    International Nuclear Information System (INIS)

    Among the different ways to treat prostate cancer, brachytherapy with iodine- 125 seeds is an option that provides good results and fewer side effects. In the present study several deposition methods of radioactive iodine in a silver substrate were compared in order to choose the most suitable alternative for the routine production to be implemented at IPEN's laboratory. The methodology used was chosen based on the available infrastructure and experience of the researchers present. Therefore, the 131I was used for testing (same chemical behavior as 131I). Four methods were selected: Method 1 (test based on electrodeposition method developed by D.Kubiatowicz) presented 65.16% efficiency; Method 2 (chemical reaction based on the method developed by D. Kubiatowicz - HCl) with the result of 70.80% efficiency; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) with 55.80% efficiency; Method 4 (IQ-IPEN) resulted in 99% efficiency. Since this method has more radioactive material fixation (which represents virtually the entire cost of the seed), the final price is the cheapest. This method is the suggested one to be implemented in the IPEN's laboratory for brachytherapy sources production. Besides, the method is the fasted one. (author)

  1. A simplified analytical dose calculation algorithm accounting for tissue heterogeneity for low-energy brachytherapy sources.

    Science.gov (United States)

    Mashouf, Shahram; Lechtman, Eli; Beaulieu, Luc; Verhaegen, Frank; Keller, Brian M; Ravi, Ananth; Pignol, Jean-Philippe

    2013-09-21

    The American Association of Physicists in Medicine Task Group No. 43 (AAPM TG-43) formalism is the standard for seeds brachytherapy dose calculation. But for breast seed implants, Monte Carlo simulations reveal large errors due to tissue heterogeneity. Since TG-43 includes several factors to account for source geometry, anisotropy and strength, we propose an additional correction factor, called the inhomogeneity correction factor (ICF), accounting for tissue heterogeneity for Pd-103 brachytherapy. This correction factor is calculated as a function of the media linear attenuation coefficient and mass energy absorption coefficient, and it is independent of the source internal structure. Ultimately the dose in heterogeneous media can be calculated as a product of dose in water as calculated by TG-43 protocol times the ICF. To validate the ICF methodology, dose absorbed in spherical phantoms with large tissue heterogeneities was compared using the TG-43 formalism corrected for heterogeneity versus Monte Carlo simulations. The agreement between Monte Carlo simulations and the ICF method remained within 5% in soft tissues up to several centimeters from a Pd-103 source. Compared to Monte Carlo, the ICF methods can easily be integrated into a clinical treatment planning system and it does not require the detailed internal structure of the source or the photon phase-space. PMID:23965939

  2. Chemical digestion and radionuclidic assay of TiNi-encapsulated 32P intravascular brachytherapy sources

    International Nuclear Information System (INIS)

    A very quantitative, destructive assay procedure was devised for accurately measuring the 32P activity content of TiNi-encapsulated intravascular brachytherapy sources and was applied to four different sources (termed 'seeds') which were developed and provided by Guidant Intravascular Intervention (formerly NeoCardia). These seeds are intended for use in the prophylactic treatment of restenosis following balloon angioplasty in heart-disease patients. The assays involved the dissolution of the TiNi jacket, extraction of the activity from the internal 32P-containing source material, quantitative solution transfers, and a gravimetrically-based dilution; followed by liquid scintillation (LS) spectrometry of the resulting master solution with 3H-standard efficiency tracing using composition-matched LS cocktails. The LS spectrometry utilized a previously-developed method for resolving the always-present 33P impurity. The protocol included provisions for accounting for all possible losses of 32P in the digestion procedure (based on radiochemical tracing experiments), for any unrecovered activity in the remaining source material, and for any residual activity in the solution-transfer and containing vessels. Sections of the TiNi jackets adjacent to the cut-off active seed portions were also assayed for any contained activity. Such destructive assays were required for relating measurements of the absorbed dose spatial distribution for the seeds to theoretic dose modelling and for establishing calibration factors for subsequent non-destructive radionuclidic measurements on the seeds

  3. Intercomparison of ionisation chamber measurements from {sup 125}I seeds

    Energy Technology Data Exchange (ETDEWEB)

    Davies, J.B. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Building 23, Lucas Heights, NSW 2234 (Australia); Institute of Medical Physics, University of Sydney, NSW 2006 (Australia); E-mail: jbd@ansto.gov.au; Enari, K.F. [Cancer Care Centre, St George Hospital, Kogarah, NSW 2217 (Australia); Baldock, C. [Institute of Medical Physics, University of Sydney, NSW 2006 (Australia)

    2007-05-15

    The reference air kerma rates of a set of individual {sup 125}I seeds were calculated from current measurements of a calibrated re-entrant ionisation chamber. Single seeds were distributed to seven Australian brachytherapy centres for the same measurement with the user's instrumentation. Results are expressed as the ratio of the reference air kerma rate measured by the Australian Nuclear Science and Technology Organisation (ANSTO) to the reference air kerma rate measured at the centre. The intercomparison ratios of all participants were within {+-}5% of unity.

  4. Langzeitergebnisse bei Aderhautmelanom nach 106Ruthenium-Brachytherapie

    OpenAIRE

    Krause, Nona

    2015-01-01

    Introduction: 106Ruthenium-brachytherapy (106Ru-brachytherapy) is an established therapy for small and medium-sized uveal melanomas. The aim of this study was to examine the long-time results in regard to recurrence rate, complication rate, ocular preservation, metastasis rate and survival with malignant uveal and ciliary body melanoma, as well as relevant prognosis factors, subsequent to 106Ru-brachytherapy. Methodology: In this retrospective study of all cases with uveal or with ciliary ...

  5. Low dose rate Ir-192 interstitial brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Yosuke; Dokiya, Takushi; Yorozu, Atsunori; Suzuki, Takayuki; Saito, Shiro; Monma, Tetsuo; Ohki, Takahiro [National Tokyo Medical Center (Japan); Murai, Masaru; Kubo, Atsushi

    2000-04-01

    From December 1997 through January 1999, fifteen prostatic cancer patients were treated with low dose rate Ir-192 interstitial brachytherapy using TRUS and perineal template guidance without external radiotherapy. Up to now, as no apparent side effects were found, the safety of this treatment is suggested. In the future, in order to treat prostatic cancer patients with interstitial brachytherapy using I-125 or Pd-103, more investigation for this low dose rate Ir-192 interstitial brachytherapy is needed. (author)

  6. Radiation protection after interstitial permanent prostate brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Pirraco, R.; Pereira, A.; Cavaco, A. [Instituto Portugues de Oncologia Francisco Gentil - Centro R egional de Oncologia do Porto, SA, Porto (Portugal)

    2006-07-01

    Full text of publication follows: In this study we measure patients radiation exposure dose after interstitial {sup 125}I permanent prostate Brachytherapy implants, and correlate it with dose limits for public, total activity implanted, patient preoperative weight(1), distance between prostate walls and anterior skin surface. Methods and Material: We analyse 20 patients who were implanted with {sup 125}I seeds. The instrument used to measure radiation is a calibrated Berthold Umo LB 123 aco-plated to a LB 1236-H10 detector. Three measurements were taken: at the perineal and anterior pelvic zones on contact with the skin and at 1 m from the patient. The maximum value was taken for all measurements. The dose at a distance of one meter is obtained at anterior pelvic zone, perpendicular to the skin, according to the recommendations of A.A.P.M.(1). The distance between prostate walls was determined using post -operative CT images. Results: The doses at the perineal zone have determined an average of 186 {mu}Sv/h (range: 110 340 {mu}Sv/h) and at surface pelvic zone of 41 {mu}Sv/h (range: 15 103 {mu}Sv/h). The dose at a distance of 1 meter has an average value of 0.4 {mu}Sv/h (range: 0.2 1.0 {mu}Sv/h). The average total activity implanted was 25 mCi (range: 17 38 mCi). The distance between prostate walls and skin pelvic surface of the patients has an average value of 8.9 cm (range: 6.6 -11.5 cm). At a distance of 1 meter from the pelvic zone the dose measured is very low and below dose limits imposed by the European Directive EURATOM 2 and the Portuguese law. For general public to reach annual dose limit (EURATOM - 1 mSv/year) when contacting the pelvic zone, we extrapolate that 4 days (range: 1.6 11.1 days) would be needed, assuming a daily contact period of 6 hours. Conclusion: We established a correlation between the distance of prostate walls to the skin perineal surface and the total dose, but we find no correlation between measured doses, total activity implanted

  7. Brachytherapy in the treatment of genitourinary rhabdomyosarcoma in children

    International Nuclear Information System (INIS)

    Brachytherapy has been widely used at the Institut Gustave Roussy since 1972 in pediatric oncology. In genitourinary rhabdomyosarcoma, because of its ballistic and physical characteristics, it represents the optimal treatment whenever irradiation is required and brachytherapy feasible. Between 1976 and 1998, 23 children with bladder or prostate rhabdomyosarcoma were treated with a protocol including brachytherapy, with five of them treated with a salvage brachytherapy. All but one brachytherapy was performed during the surgery. Among the 18 brachy-therapies performed as a first-line treatment, eight presented a tumoral evolution: five presented a local evolution, one a local and nodal evolution and two a nodal evolution. Brachytherapy allowed a conservative treatment among ten out of 11 children alive with no evidence of disease. Among the five patients with salvage brachytherapy, two presented a second recurrence. Sequelae were minimal, consisting of one grade I rectitis and one asymptomatic vesical and ureteral reflux. These results are consistent with the published data using more radical treatment. Brachytherapy can represent an alternative to radical surgery, when indications are clearly defined in bladder or prostate rhabdomyosarcoma. This type of treatment can be performed only integrated with other treatments, more particularly with surgery. This approach requires a close cooperation between the different specialists: pediatricians, surgeons and brachy-therapists. (authors)

  8. Implementation of High Dose Rate Brachytherapy in Limited Resource Settings

    International Nuclear Information System (INIS)

    Brachytherapy is an essential component of the curative treatment of cervical cancer, a disease with high incidence in many developing countries The IAEA supports the use of high dose rate brachytherapy for centres with a large number of patients with this disease. HDR brachytherapy is also used in other common cancers such as breast cancer, lung, oesophagus and prostate. This publication provides guidance to radiation oncologists, medical physicists and planners on establishing and operating a high dose rate brachytherapy unit with modern standards and presents the main issues to be addressed for its effective and safe operation

  9. Cost effective method of manual afterloading 192Ir brachytherapy

    International Nuclear Information System (INIS)

    Full text: In radiotherapy, brachytherapy mode of treatment has equal importance like the external beam radiotherapy. In our hospital we have manual afterloading 137Cs kit supplied by BRIT for intracavitary treatment of carcinoma cervix and vaginal cases. In July 1999, we also started afterloading 192Ir brachytherapy. For a hospital like ours, where funds are minimal, it is impossible to procure remote afterloading brachytherapy unit, which is very costly. So we have developed the cost-effective 192Ir manual brachytherapy and so far we have done 60 cases which include intraluminal and interstitial cases

  10. Experimental dosimetry of Ho-166 bioglass seed polymer-protected

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Luciana B.; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This study aims to develop experimental dosimetry of Ho-166 bio glass seed for brachytherapy studies using GAFCHROMIC EBT2 radio chromium films. The methodology consists of placement of radio chromium films in a compressed breast phantom, along with bio glass polymer-protected seeds of [Si: Ca: Ho] and [Si: Ca: Ho: Zr]. The bio glass seeds were encapsulated with polyvinyl alcohol, before being activated and used in the study. The bio glass seeds were introduced into the breast phantom, along with radio chromium films for a period of 2 hours. After the exposure time, radio chromium films were removed from phantom and digitized for analysis in ImageDIG 2.0 program, which quantifies the intensity of RGB (Red, Green, Blue). The dose calculation was evaluated by Monte Carlo technique. Experimental and theoretical data were used to calibrate the dose distribution. The results were plotted on graphs and dose iso curves were obtained. As conclusion it is possible to perform dosimetry in Ho-166 seed brachytherapy using radio chromium films, limited to a short exposure time and small activity. (author)

  11. Evaluation of hela cell lineage response to β radiation from Holmium-166 embedded in ceramic seeds

    Directory of Open Access Journals (Sweden)

    Eduardo Sarmento Valente

    2011-10-01

    Full Text Available This work studied the effects of β radiation of Ho-166 embedded in ceramic seeds on HeLa cells. Methodology consisted in the production of ceramic seeds with holmium-165 by sol-gel route. Chemical and physical characterizations of the seeds were performed. Subsequently, nuclear characterization was performed by gamma spectrometry. Experimental and theoretical activities were defined and initial dose rate were evaluated by MIRD (Medical Internal Radiation Dose Committee methodology. The seeds were placed in confluent culture flasks and remained for six radionuclide half-lives. Biological results were represented by a clean 6 mm diameter area around the seed where the tumour cells were killed. The initial dose rate was 15.5 Gy. h-1. The maximum absorbed dose was 591.3 Gy. The features of the Ho-166 seeds suggested that such ceramic seeds were suitable for high dose rate brachytherapy.

  12. A comparison of complications between ultrasound-guided prostate brachytherapy and open prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Prostate brachytherapy has reemerged during the 1990s as a treatment for clinically localized prostate cancer. The renewed popularity of prostate brachytherapy is largely due to the use of transrectal ultrasound of the prostate, which allows for more accurate isotope placement within the prostate when compared to the open approach. The present study investigates whether this improved cancer control is at the expense of increased morbidity by comparing the morbidity after transrectal ultrasound-guided prostate brachytherapy to the morbidity after prostate brachytherapy performed via an open approach. Methods and Materials: All men in the Medicare population who underwent prostate brachytherapy in the year 1991 were identified. These men were further stratified into those men who underwent prostate brachytherapy via an open approach and the men who underwent prostate brachytherapy with ultrasound guidance. All subsequent inpatient, outpatient, and physician (Part B) Medicare claims for these men from the years 1991-1993 were then analyzed to determine outcomes. Results: In the year 1991, 2124 men in the Medicare population underwent prostate brachytherapy. An open approach was used in 715 men (33.7%), and ultrasound guidance was used in 1409 men (66.3%). Mean age for both cohorts was 73.7 years with a range of 50.7-92.8 years for the ultrasound group and 60.6-92.1 years for the open group. A surgical procedure for the relief of bladder outlet obstruction was performed in 122 men (8.6%) in the ultrasound group and in 54 men (7.6%) in the open group. An artificial urinary sphincter was placed in 2 men (0.14%) in the ultrasound group and in 2 men (0.28%) in the open group. A penile prosthesis was implanted in 10 men (0.71%) in the ultrasound group and in 4 men (0.56%) in the open group. A diagnosis code for urinary incontinence was carried by 95 men (6.7%) in the ultrasound group and by 45 men (6.3%) in the open group. A diagnosis code for erectile dysfunction

  13. A reappraisal of local anesthesia for prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Faced with rapidly increasing patient numbers, the authors adopted and modified a technique to perform prostate implants under local anesthesia in a radiation oncology facility. Our reasons for assembling the current report detailing 20 consecutive, unselected patients are to show how patients tolerate brachytherapy without the use of sedatives, to provide more technical detail regarding the procedure's practical aspects, and to summarize the time needed to complete its components. Materials and methods: No pre-operative medication is given. The patient is placed in the lithotomy position, using stirrups mounted on the end of the simulator table. A 5-cmx5-cm patch of perineal skin and subcutaneous tissue is anesthetized by local infiltration of 3--5 cm3 of 0.5% lidocaine, using a 25-gauge 1.5-inch needle. Immediately following injection into the subcutaneous tissues, the deeper tissues, of the pelvic floor are anesthetized by injecting 5 cm3 lidocaine solution with approximately 16 passes of a 25-gauge 1.5-inch needle entering perpendicular to the skin surface. The transrectal ultrasound (TRUS) probe of a Siemens SONOLINE Prima ultrasound machine (6.0 MHz) and a Winston-Barzell stepper unit is next positioned to reproduce the planning images and a 3.5-inch, 22-gauge spinal needle is inserted into the peripheral and a few central tracks. About 0.5 cm3 of lidocaine solution is injected into each intraprostatic track, as the needle is slowly advanced. Finally, a 7-inch 22-gauge spinal needle inserted through the skin via a 3.5-inch 18-gauge needle, is used to anesthetize to the base of the prostate under TRUS and fluoroscopic guidance. Seed placement is done with a Mick ApplicatorTM, inserting and loading one needle at a time. The number of seeds placed ranged from 60 to 118 (average: 87) and the number of needles used ranged from 14 to 20 (average: 18). For the purpose of this study, prior to walking to the simulator suite, patients were asked to rate the

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

    International Nuclear Information System (INIS)

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

  15. Development of a Brachytherapy Software Nomogram Equivalent

    International Nuclear Information System (INIS)

    The main objective of this project is developing a software nomogram equivalent. A nomogram is a graph typically comprised of three parallel lines. Each of the lines is graduated for a different variable, often in a non-linear scale. The lines are oriented in such a manner that if a straight line is drawn connecting two of the three variables, the value of the third variable is uniquely determined by the intersection of the connecting line and the graduated line of the third variable. The value of the third variable is determined by reading the graduated scale at the point of intersection. A nomogram as applied in brachytherapy is used for determining the required amount of radioactive material to be implanted in a diseased site. A typical brachytherapy nomogram relates the average dimension of a site, the air kerma strength per source and the number of sources required for yielding a therapeutic radiation dose to the site. More sophisticated nomograms also provide scales for recommending source and needle spacings. For decades the nomogram has been clinically employed as a brachytherapy treatment planning tool. Imaging modalities such as CT and ultrasound ushered in modern image-based brachytherapy treatment planning. These modern imaging techniques dramatically advanced the state of the art of brachytherapy, often obviating the use of nomograms. Although the routine use of nomograms has decreased, there are clinical situations where nomograms still prove useful for brachytherapy treatment planning. Often times the dimensions of a tumor or tumor bed are not known prior to surgery and delineated images of the site are not available. In such situations the tumor dimensions can be measured in the OR and a nomogram applied for rapid treatment planning. By definition a nomogram is a graphical tool, which is fixed and cannot be modified. Differences of opinion and treatment philosophies exist among physicians and institutions. These varying approaches can lead to

  16. Decline in urinary retention incidence in 805 patients after prostate brachytherapy: The effect of learning curve?

    International Nuclear Information System (INIS)

    Purpose: To evaluate the incidence and factors predictive of acute urinary retention (AUR) in 805 consecutive patients treated with prostate brachytherapy monotherapy and to examine the possible effect of a learning curve. Methods and Materials: Between July 1998 and November 2002, 805 patients were treated with prostate brachytherapy. Low-risk patients (Gleason Score (GS) ≤6; prostate specific antigen (PSA) ≤10, and ≤ T2b [UICC 1997]) received implant alone. Patients with prostate volume of 50 cc or more, GS = 7, or PSA = 10 to 15 received 6 months of androgen suppression (AS) with brachytherapy. Patient, treatment, and dosimetric factors examined include baseline prostate symptom score (IPSS), diabetes, vascular disease, PSA, Gleason score, clinical stage, AS, ultrasound planning target volume (PUTV), postimplant prostate volume (obtained with 'Day 30' postimplant CT), CT:PUTV ratio (surrogate for postimplant edema), number of seeds, number of needles, number of seeds per needle, dosimetric parameters (V100, V150, and D90), date of implant (learning curve), and implanting oncologists. Univariate and multivariate analyses were carried out. Results: Acute urinary retention in the first 200 patients was 17% vs. 6.3% in the most recently treated 200 patients (p = 0.002). Overall AUR was 12.7%, and prolonged urinary obstruction incidence (>20 days) was 5%. On multivariate analysis, factors predictive of any AUR include baseline IPSS (p = 20 days) on multivariate analysis include IPSS (p < 0.01), number of needles (p < 0.001), diabetes mellitus (p = 0.048), and CT:PUTV ratio (p < 0.001) Conclusion: Over the years, our AUR rate has fallen significantly (from 17% to 6.3%). On multivariate analysis, highly significant factors include IPSS, PUTV, CT:PUTV ratio (i.e., degree of prostate edema), and order of implant (learning curve). Over the course of the program, we have deliberately reduced the number of needles and OR time per patient, which have potentially

  17. Gold marker displacement due to needle insertion during HDR-brachytherapy for treatment of prostate cancer: A prospective cone beam computed tomography and kilovoltage on-board imaging (kV-OBI) study

    International Nuclear Information System (INIS)

    To evaluate gold marker displacement due to needle insertion during HDR-brachytherapy for therapy of prostate cancer. 18 patients entered into this prospective evaluation. Three gold markers were implanted into the prostate during the first HDR-brachytherapy procedure after the irradiation was administered. Three days after marker implantation all patients had a CT-scan for planning purpose of the percutaneous irradiation. Marker localization was defined on the digitally-reconstructed-radiographs (DRR) for daily (VMAT technique) or weekly (IMRT) set-up error correction. Percutaneous therapy started one week after first HDR-brachytherapy. After the second HDR-brachytherapy, two weeks after first HDR-brachtherapy, a cone-beam CT-scan was done to evaluate marker displacement due to needle insertion. In case of marker displacement, the actual positions of the gold markers were adjusted on the DRR. The value of the gold marker displacement due to the second HDR-brachytherapy was analyzed in all patients and for each gold marker by comparison of the marker positions in the prostate after soft tissue registration of the prostate of the CT-scans prior the first and second HDR-brachytherapy. The maximum deviation was 5 mm, 7 mm and 12 mm for the anterior-posterior, lateral and superior-inferior direction. At least one marker in each patient showed a significant displacement and therefore new marker positions were adjusted on the DRRs for the ongoing percutaneous therapy. Needle insertion in the prostate due to HDR-brachytherapy can lead to gold marker displacements. Therefore, it is necessary to verify the actual position of markers after the second HDR-brachytherapy. In case of significant deviations, a new DRR with the adjusted marker positions should be generated for precise positioning during the ongoing percutaneous irradiation

  18. 10 CFR 35.400 - Use of sources for manual brachytherapy.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Use of sources for manual brachytherapy. 35.400 Section 35.400 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.400 Use of sources for manual brachytherapy. A licensee shall use only brachytherapy sources...

  19. Radiochromic dye film studies for brachytherapy applications.

    Science.gov (United States)

    Martínez-Dávalos, A; Rodríguez-Villafuerte, M; Díaz-Perches, R; Arzamendi-Pérez, S

    2002-01-01

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200 with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. PMID:12382798

  20. Radiochromic dye film studies for brachytherapy applications

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Davalos, A.; Rodriguez-Villafuerte, M.; Diaz-Perches, R.; Arzamendi-Perez, S

    2002-07-01

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate {sup 137}Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200) with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. (author)

  1. Radiochromic dye film studies for brachytherapy applications

    International Nuclear Information System (INIS)

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200) with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. (author)

  2. The evolution of brachytherapy treatment planning

    International Nuclear Information System (INIS)

    Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

  3. The evolution of brachytherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, Mark J.; Venselaar, Jack L. M.; Beaulieu, Luc [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Department of Medical Physics, Instituut Verbeeten, P.O. Box 90120, 5000 LA Tilburg (Netherlands); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Cote du Palais, Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada)

    2009-06-15

    Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

  4. Sexual function after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To determine the incidence of potency preservation following permanent prostate brachytherapy and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. Materials and Methods: 425 patients underwent permanent prostate brachytherapy from April 1995 to October 1999. 209 patients who were potent prior to brachytherapy and currently not receiving hormonal manipulation were mailed an International Index of Erectile Function (IIEF) questionnaire with a pre-addressed stamped envelope. 180 patients completed and returned the questionnaire. Median patient follow-up was 39 months (range 18-74 months). Pre-implant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Post-implant potency was defined as an IIEF score >11. Clinical parameters evaluated for sexual function included patient age, clinical T stage, elapsed time since implantation, hypertension, diabetes mellitus, and tobacco consumption. Evaluated treatment parameters included the utilization of neoadjuvant hormonal manipulation and the choice of isotope. The efficacy of sildenafil citrate in brachytherapy induced erectile dysfunction (ED) was also evaluated. Results: A pre-treatment erectile function score of 2 and 1 were assigned to 126 and 54 patients respectively. With 6 year follow up, 39% of patients maintained potency following prostate brachytherapy with a plateau on the curve. Post-implant preservation of potency (IIEF>11) correlated with pre-implant erectile function (50% versus 14% for pre-implant scores of 2 and 1 respectively, p≤0.0001), patient age (56%, 38%, and 23% for patients <60 years of age, 60-69 years of age, and ≥70 years of age respectively, p=0.012) and a history of diabetes mellitus

  5. Evolution of dose distribution calculations in brachytherapy

    International Nuclear Information System (INIS)

    In this report the evolution of dose distribution calculations is revised in detail, considering the simplest case (a point source in free space) and the more complex situation of a real encapsulated line source embedded in a scattering medium. The most recent formalism to perform the dosimetry of interstitial brachytherapy sources is presented, where measured or measurable dose rates from actual sources in a tissue equivalent phantom are required as input data

  6. Brachytherapy in treatment of vaginal cancer

    OpenAIRE

    A. D. Kaprin; V. N. Galkin; S. A. Ivanov; V. A. Solodkiy; V. A. Titova

    2016-01-01

    Characteristics of diagnosis and treatment of different types of primary vaginal cancer are highlighted, the role and place of brachytherapy as independent method or combined treatment modality for this pathology is shown in the review. Epidemiological data on incidence of vaginal cancer in Russia are represented, presumptive mechanisms for development of the disease, risk factors, histological types, features of the course, clinical presentation, diagnostic algorithm are described. Treatment...

  7. Procedures for calibration of brachytherapy sources

    International Nuclear Information System (INIS)

    Brachytherapy source strength verification is a responsibility of the user of these source, in fact of the Medical Physicists in charge of this issue in a Radiotherapy Service. The calibration procedures in the users conditions are shown. Specifics methods for source strength determination are recommended, both for High Dose Rate (HDR) sources with Remote Afterloading equipment and for Low Dose Rate sources. The The results of the calibration of HDR Remote After loaders are indicated

  8. Erectile Function Durability Following Permanent Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To evaluate long-term changes in erectile function following prostate brachytherapy. Methods and Materials: This study included 226 patients with prostate cancer and preimplant erectile function assessed by the International Index of Erectile Function-6 (IIEF-6) who underwent brachytherapy in two prospective randomized trials between February 2001 and January 2003. Median follow-up was 6.4 years. Pre- and postbrachytherapy potency was defined as IIEF-6 ≥ 13 without pharmacologic or mechanical support. The relationship among clinical, treatment, and dosimetric parameters and erectile function was examined. Results: The 7-year actuarial rate of potency preservation was 55.6% with median postimplant IIEF of 22 in potent patients. Potent patients were statistically younger (p = 0.014), had a higher preimplant IIEF (p < 0.001), were less likely to be diabetic (p = 0.002), and were more likely to report nocturnal erections (p = 0.008). Potency preservation in men with baseline IIEF scores of 29-30, 24-28, 18-23, and 13-17 were 75.5% vs. 73.6%, 51.7% vs. 44.8%, 48.0% vs. 40.0%, and 23.5% vs. 23.5% in 2004 vs. 2008. In multivariate Cox regression analysis, preimplant IIEF, hypertension, diabetes, prostate size, and brachytherapy dose to proximal penis strongly predicted for potency preservation. Impact of proximal penile dose was most pronounced for men with IIEF of 18-23 and aged 60-69. A significant minority of men who developed postimplant impotence ultimately regained erectile function. Conclusion: Potency preservation and median IIEF scores following brachytherapy are durable. Thoughtful dose sparing of proximal penile structures and early penile rehabilitation may further improve these results.

  9. Magnetite nanoparticles for nonradionuclide brachytherapy1

    OpenAIRE

    Safronov, Victor; Sozontov, Evgeny; Polikarpov, Mikhail

    2015-01-01

    Magnetite nanoparticles possess several properties that can make them useful for targeted delivery of radiation to tumors for the purpose of brachytherapy. Such particles are biodegradable and magnetic and can emit secondary radiation when irradiated by an external source. In this work, the dose distribution around a magnetite particle of 10 nm diameter being irradiated by monochromatic X-rays with energies in the range 4–60 keV is calculated.

  10. Dosimetry in high dose rate endoluminal brachytherapy

    International Nuclear Information System (INIS)

    In endoluminal brachytherapy for the tracheobronchial tree, esophagus, and bile duct, a reference point for dose calculation has been often settled at 1 cm outside from the middle of source travel path. In the current study, a change in the ratio of the reference point dose on the convex to concave side (Dq/Dp) was calculated, provided the source travel path bends as is the case in most endoluminal brachytherapies. Point source was presumed to move stepwise at 1 cm interval from 4 to 13 locations. Retention time at each location was calculated by personal computer so as to deliver equal dose at 1 cm from the linear travel path. With the retention time remaining constant, the change of Dq/Dp was assessed by bending the source travel path. Results indicated that the length of the source travel path and radius of its curve influenced the pattern of change in Dq/Dp. Therefore, it was concluded that the difference in reference dose on the convex and concave side of the curved path is not negligible under certain conditions in endoluminal brachytherapy. In order to maintain the ratio more than 0.9, relatively greater radius was required when the source travel path was decreased. (author)

  11. Paraspinal tumors: Techniques and results of brachytherapy

    International Nuclear Information System (INIS)

    Because of their proximity to nerve roots and the spinal cord, it is frequently difficult to achieve complete resection of paraspinal tumors. We have used brachytherapy in an attempt to prevent local recurrence and its associated neurological sequelae. This report analyzes our experience with 35 patients to determine the feasibility, optimal techniques, and efficacy of this approach. The tumor types were non small-cell lung cancer (18), sarcomas (9), and other tumor types (8). Temporary, single plane implants using Ir-192 (median minimum peripheral dose 3000 cGy) were used in 21 patients, and permanent I-125 implants were used in 14 cases (median matched peripheral dose 12,500 cGy). Local control was achieved in 51% (18/35). However, local control was poor when lung cancers were implanted and in cases where the dura was exposed. Radiation myelitis did not occur despite the combined effects of previous external beam radiotherapy (N = 21) and brachytherapy. Our experience demonstrates that combined surgery and paraspinal brachytherapy can be performed with acceptable toxicity and is reasonably effective in preventing local relapse and its neurologic sequelae, particularly for tumors other than lung cancers

  12. Brachytherapy treatment with high dose rate

    International Nuclear Information System (INIS)

    Retrospectively analyze results and prognostic factors of cervical cancer patients treated with radio concomitant cisplatin-based chemotherapy, radiation therapy combined modality. Methods: From January 2003 to December 2007, 198 patients with invasive cervical cancer were treated at the Oncology Department of Hospital Robau Celestino Hernandez (brachytherapy performed at INOR). The most common age group was 31 to 40 years. The histology in squamous cell carcinoma accounted for 84.3% of cases. The treatment consisted of external pelvic irradiation and vaginal brachytherapy, high dose rate. Concomitant chemotherapy consisted of cisplatin 40 mg/m2 weekly with a maximum of 70 mg for 5 weeks. Results: 66.2% of patients completed 5 cycles of chemotherapy. The median overall survival was 39 months, overall survival, disease-free survival and survival free of locoregional recurrence at 5 years of 78%, 76% and 78.6% respectively .. We found that clinical stage, histological type (adenocarcinoma worst outcome) were statistically related to level of response. Conclusions: Treatment with external pelvic radiation, brachytherapy and concurrent weekly cisplatin in patients with stage IIIB cervical cancer is feasible in the Chilean public health system, well tolerated and results comparable to international literature. (Author)

  13. Establishing High-Quality Prostate Brachytherapy Using a Phantom Simulator Training Program

    Energy Technology Data Exchange (ETDEWEB)

    Thaker, Nikhil G. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kudchadker, Rajat J. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Swanson, David A. [Department of Urology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Albert, Jeffrey M. [Department of Radiation Oncology, Banner Health, Loveland/Greeley, Colorado (United States); Mahmood, Usama; Pugh, Thomas J.; Boehling, Nicholas S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Bruno, Teresa L. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Prestidge, Bradley R. [Department of Radiation Oncology, Bon Secours Health System, Norfolk, Virginia (United States); Crook, Juanita M. [Department of Radiation Oncology, Cancer Center for the Southern Interior, Kelowna, British Columbia (Canada); Cox, Brett W.; Potters, Louis [Department of Radiation Medicine, North Shore-LIJ Health System, New Hyde Park, New York (United States); Moran, Brian J. [Chicago Prostate Center, Westmont, Illinois (United States); Keyes, Mira [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver Center, Vancouver, British Columbia (Canada); Kuban, Deborah A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Frank, Steven J., E-mail: sjfrank@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-11-01

    Purpose: To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education. Methods and Materials: Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 ({sup 125}I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parameters were compared and correlated using regression analysis. Results: Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process. Conclusions: Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB.

  14. Establishing High-Quality Prostate Brachytherapy Using a Phantom Simulator Training Program

    International Nuclear Information System (INIS)

    Purpose: To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education. Methods and Materials: Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 (125I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parameters were compared and correlated using regression analysis. Results: Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process. Conclusions: Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB

  15. Radiation Exposure Reduction to Brachytherapy Staff By Using Remote Afterloading

    International Nuclear Information System (INIS)

    The radiation exposures to the personnel staff from patients with brachytherapy implants in a brachytherapy service were reviewed. Exposures to the brachytherapy personnel, as determined by Thermoluminescence Dosimeter (TLD) monitors, indicates a four-fold reduction in exposures after the implantation of the use of remote afterloading devices. Quarterly TLD monitor data for seven quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the brachytherapy staff of 2543 Μ Sv. After the implantation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per person of 153 Μ Sv. This is 76% reduction in exposure to brachytherapy personnel with the use of these devices

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: wwang21@partners.org [Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115 and Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Viswanathan, Akila N.; Damato, Antonio L.; Cormack, Robert A. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Chen, Yue; Tse, Zion [Department of Engineering, The University of Georgia, Athens, Georgia 30602 (United States); Pan, Li [Siemens Healthcare USA, Baltimore, Maryland 21287 (United States); Tokuda, Junichi; Schmidt, Ehud J. [Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Seethamraju, Ravi T. [Siemens Healthcare USA, Boston, Massachusetts 02115 (United States); Dumoulin, Charles L. [Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio 45229 (United States)

    2015-12-15

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

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

    International Nuclear Information System (INIS)

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

  18. Predictive Factors and Management of Rectal Bleeding Side Effects Following Prostate Cancer Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Price, Jeremy G. [Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York (United States); Stone, Nelson N. [Department of Urology, Icahn School of Medicine at Mount Sinai, New York, New York (United States); Stock, Richard G., E-mail: Richard.Stock@mountsinai.org [Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York (United States)

    2013-08-01

    Purpose: To report on the incidence, nature, and management of rectal toxicities following individual or combination brachytherapy following treatment for prostate cancer over a 17-year period. We also report the patient and treatment factors predisposing to acute ≥grade 2 proctitis. Methods and Materials: A total of 2752 patients were treated for prostate cancer between October 1990 and April 2007 with either low-dose-rate brachytherapy alone or in combination with androgen depletion therapy (ADT) or external beam radiation therapy (EBRT) and were followed for a median of 5.86 years (minimum 1.0 years; maximum 19.19 years). We investigated the 10-year incidence, nature, and treatment of acute and chronic rectal toxicities following BT. Using univariate, and multivariate analyses, we determined the treatment and comorbidity factors predisposing to rectal toxicities. We also outline the most common and effective management for these toxicities. Results: Actuarial risk of ≥grade 2 rectal bleeding was 6.4%, though notably only 0.9% of all patients required medical intervention to manage this toxicity. The majority of rectal bleeding episodes (72%) occurred within the first 3 years following placement of BT seeds. Of the 27 patients requiring management for their rectal bleeding, 18 underwent formalin treatment and nine underwent cauterization. Post-hoc univariate statistical analysis revealed that coronary artery disease (CAD), biologically effective dose, rectal volume receiving 100% of the prescription dose (RV100), and treatment modality predict the likelihood of grade ≥2 rectal bleeding. Only CAD, treatment type, and RV100 fit a Cox regression multivariate model. Conclusions: Low-dose-rate prostate brachytherapy is very well tolerated and rectal bleeding toxicities are either self-resolving or effectively managed by medical intervention. Treatment planning incorporating adjuvant ADT while minimizing RV100 has yielded the best toxicity-free survival following

  19. Development of a patient-reported questionnaire for collecting toxicity data following prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To improve a questionnaire used to collect patient-reported outcomes from patients with early stage prostate cancer treated with brachytherapy. A secondary aim was to adapt the Late Effects of Normal Tissue (LENT) subjective toxicity questionnaire for use to collect Common Terminology Criteria for Adverse Events (CTCAE) data, the current preferred platform for assessing radiation toxicity. Materials and methods: Three hundred and seventy-seven patients were treated with permanent iodine-125 seed implant brachytherapy for early prostate cancer. Toxicity data were collected before and at nine time points post-treatment (0-36 months). Compliance rates for patients completing individual items and item-subsection correlation coefficients were calculated. A factor analysis was carried out to analyse responses to the questionnaire and identify less informative questions, which could be removed. Cronbach's α coefficient was used to measure reliability. Results: Two thousand one hundred and eighty-eight questionnaires were analysed. There was poor compliance for questions specifically relating to operations and bowel medication. We found that the division of the questionnaire into subsections based on anatomical site was reasonable and that certain items could be safely removed. The high mean value for Cronbach's α across all questionnaires (0.752; 95% CI: 0.726-0.779) indicated that the questionnaire was reliable. Fifteen of the 44 questions were removed from the original questionnaires. Questions on urinary incontinence severity, management of urinary and bowel incontinence, effects of reduced flow of urine and the effects of symptoms on activity of daily living and change in sexual function were required to adapt the LENT subjective questionnaire for use to collect CTCAE data. Conclusions: A questionnaire, validated over 6 years to collect LENT subjective data were adapted and is a reliable approach for collecting CTCAE data after prostate brachytherapy.

  20. Erectile function after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To determine the incidence of potency preservation after permanent prostate brachytherapy using a validated patient-administered questionnaire and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. Methods and Materials: Four hundred twenty-five patients underwent permanent prostate brachytherapy from April 1995 to October 1999. Two hundred nine patients who were potent before brachytherapy and who at the time of the survey were not receiving hormonal therapy were mailed the specific erectile questions of the International Index of Erectile Function (IIEF) questionnaire with a self-addressed stamped envelope. The questionnaire consisted of 5 questions, with a maximal score of 25. Of the 209 patients, 181 (87%) completed and returned the questionnaire. The mean and median follow-up was 40.4±14.9 and 40.6 months, respectively (range 19-75). Preimplant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Postimplant potency was defined as an IIEF score ≥11. The clinical parameters evaluated for erectile function included patient age, preimplant potency, clinical T-stage, pretreatment prostate-specific antigen level, Gleason score, elapsed time after implantation, hypertension, diabetes mellitus, and tobacco consumption. Treatment parameters included radiation dose to the prostate gland, use of hormonal manipulation, use of supplemental external beam radiotherapy (EBRT), choice of isotope, prostate volume, and planning volume. The efficacy of sildenafil citrate in brachytherapy-induced erectile dysfunction (ED) was also evaluated. Results: Pretreatment erectile function scores of 2 and 1 were assigned to 125 and 56 patients, respectively. With a 6-year follow

  1. A theoretical derivation of the nomograms for permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    This study calculates the required minimum radioactivity to deliver a prescribed dose of radiation to a target using radioisotopes in permanent prostate brachytherapy. Assuming the radioactivity to be in a continuous form, an integral equation -- Fredholm equation of the first kind, can be formulated with the radioactivity density used as the variable. The density distribution to produce a uniform volume dose rate is determined using a quadrature method and the radial profile behaves smoothly from the zero radius, and peaks sharply approaching the volume boundary. The density for Pd-103 is about 1.5 times that of I-125 due to its higher spatial attenuation. A nomogram is the relationship between the total activity per unit dose (A) and the dimension of the volume (d). Expressing the nomogram as A=cxdn U/Gy, then (c,n)= [(0.0098, 2.09) I-125] and [(0.031, 2.25) Pd-103]. Compared with the Memorial nomogram, (c,n)=[(0.011,2.2) I-125] and [(0.036,2.56) Pd-103], or that quoted by AAPM TG64, (c,n)=[(0.014,2.05) I-125] and [(0.056,2.22) Pd-103], our calculation determined an average 33% and 35% decrease for I-125, and 89% and 77% decrease for Pd-103, respectively. Two reasons for the extra total activity found in the Memorial and AAPM nomograms are: (a) An imperfect clinical situation limited by the restraints of implant techniques (e.g., use of templates) associated with the presence of adjacent normal organs, and (b) source discretization into seeds. When radioactivity is clumped as discrete seeds, higher activity is needed because of 'wastage' in two aspects: (a) Dose cold-spots at intersource spaces, (b) hot-spots around the sources. Thus in theory, use of lower activity seeds will require less total activity to deliver a prescribed dose. Based on our study, Pd-103 delivers a higher therapeutic ratio and a lower integral dose to the patient compared to I-125

  2. New brachytherapy standards paradigm shift

    International Nuclear Information System (INIS)

    Full text: The absorbed dose rate to water at short distances (1 cm typically) in water, is the quantity of interest for dosimetry in radiotherapy treatments. Moreover, the dose imparted to cancer patients must be known within a narrow band of uncertainty to avoid either damage to the healthy tissue resulting from exceeding international accepted tolerance levels or lack of tumor control due to a low dose delivered to the target volume. The goal for the uncertainty of the dose delivered to the target volume would be around 5% (at the level of one standard deviation), to assure the effectiveness of the radiotherapy treatment. This also takes into account the uncertainties in dose calculation algorithms. In current brachytherapy (BT) treatments, the procedures to determine the absorbed dose imparted to the patient are not based on absorbed dose standards, but are based on measurements traceable to air kerma standards. In fact, the recommended quantity for the calibration of BT gamma ray sources is the reference air kerma rate, KR, defined as the kerma rate to air, in air, at the reference distance of 1 m from the radioactive source, corrected for air attenuation and scattering. The absorbed dose around a BT source is currently calculated by applying the formalism of the international AAPM Task Group 43 protocol and its update. This protocol is based on the air kerma strength, SK, a quantity that is numerically equivalent to KR, at a distance of 1 m from the source. The dose rate constant Λ converts the air-kerma strength SK to the absorbed dose rate to water, D.(r0,θ0), in water at the reference position: D.(r0,θ0) = SK·A (1). Recently, a lower limit of 2,50 % was obtained for the estimated overall uncertainty (at the level of one standard deviation) on measurements of D.(r0,θ0) due to a HDR 192I BT source based on equation (1). However, in most cases the determination of 5K is typically affected by an uncertainty within 0,8 % (at the level of one standard

  3. Study and methodology development for quality control in the production process of iodine-125 radioactive sealed sources applied to brachytherapy

    International Nuclear Information System (INIS)

    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)

  4. Dosimetry on ocular brachytherapy with I-125 ophthalmologic ROPES and COMS plaques

    International Nuclear Information System (INIS)

    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)

  5. Hybrid dosimetry: Feasibility of mixing angulated and parallel needles in planning prostate brachytherapy

    International Nuclear Information System (INIS)

    Pubic arch interference (PAI) often caused inadequate prostate coverage during transperineal brachytherapy using all parallel needles. In this paper, a hybrid implantation approach is presented in which additional angulated needles can be used to avoid PAI. This approach can be applied in prostate brachytherapy using a robotic assisted device. To examine the feasibility of this approach, volume data from three prostate seed implant patients were selected, which represent small, medium, and large prostates. As the blocking area was artificially increased simulating pubic arch overlap, the dosimetry outcomes and ratio of number of angulated needles to the total number of needles were analyzed. The hybrid dosimetry broke down when blocking is over 42%. As the percent of blocking increased, the ratio of the number of angulated needles to the total number of needles increased, while the dosimetry outcomes only had a slight trend of worsening. When close to the breakdown point, the dosimetry outcomes worsen drastically. Therefore, for moderate PAI the hybrid dosimetry is feasible

  6. 125I brachytherapy combined with chemotherapy for patients with inoperable stage III non-small cell lung cancer

    International Nuclear Information System (INIS)

    Objective: To assess the therapeutic effect of radioactive seed 125I brachytherapy combined with GP chemotherapy regimen (gemcitabine 1000 mg/m2, cisplatin 75 mg/m2) for inoperable stage III non-small cell lung cancer (NSCLC). Methods: Thirty-nine documented inoperable stage III NSCLC patients, enrolled between January 2005 and June 2008 for the study group, were treated with the combination of 125I brachytherapy and GP regimen. The brachytherapy methods were conducted according to TPS and each patient was treated under those patients were treated with standard GP regimen. Chest CT scans were performed every three months post-procedurally, until disease progression or recurrence. The follow-up time was up to twenty four months after treatment. In the control group, equal amount of III stage NSCLC patients were treated with standard GP regimen alone. Chi-square test and survival analysis with Kaplan-Meier and Log-rank were used to compare the differences of recent (3 months after therapy) efficiency, survival rate, survival time between two groups. Results: The re-cent effective rates of the study group (71.8%, 28/39) and control group (61.5%, 24/39) were not statistical different (χ2=0.93, P>0.05), yet the tumor CR rates in two groups showed significant disparity (χ2=4.48, P2=1.57, P>0.05). However, significant differences (χ2=4.07, 4.63,both P125I brachytherapy combined with GP regimen chemotherapy could be an effective treatment method and could improve the tumor CR rate and survival rate for patients with inoperable stage III NSCLC. (authors)

  7. Phase I Trial of Gross Total Resection, Permanent Iodine-125 Brachytherapy, and Hyperfractionated Radiotherapy for Newly Diagnosed Glioblastoma Multiforme

    International Nuclear Information System (INIS)

    Purpose: To evaluate the feasibility of gross total resection and permanent I-125 brachytherapy followed by hyperfractionated radiotherapy for patients with newly diagnosed glioblastoma. Methods and Materials: From April 1999 to May 2002, 21 patients with glioblastoma multiforme were enrolled on a Phase I protocol investigating planned gross total resection and immediate placement of permanent I-125 seeds, followed by postoperative hyperfractionated radiotherapy to a dose of 60 Gy at 100 cGy b.i.d., 5 days per week. Median age and Karnofsky performance status were 50 years (range, 32-65 years) and 90 (range, 70-100), respectively. Toxicity was assessed according to Radiation Therapy Oncology Group criteria. Results: Eighteen patients completed treatment according to protocol. The median preoperative tumor volume on magnetic resonance imaging was 18.6 cm3 (range, 4.4-41.2 cm3). The median brachytherapy dose measured 5 mm radially outward from the resection cavity was 400 Gy (range, 200-600 Gy). Ten patients underwent 12 reoperations, with 11 of 12 reoperations demonstrating necrosis without evidence of tumor. Because of high toxicity, the study was terminated early. Median progression-free survival and overall survival were 57 and 114 weeks, respectively, but not significantly improved compared with historical patients treated at University of California, San Francisco, with gross total resection and radiotherapy without brachytherapy. Conclusions: Treatment with gross total resection and permanent I-125 brachytherapy followed by hyperfractionated radiotherapy as performed in this study results in high toxicity and reoperation rates, without demonstrated improvement in survival

  8. Leakage test evaluation used for qualification of Iodine-125 seeds sealing

    International Nuclear Information System (INIS)

    Brachytherapy is one of the possible treatments with ionizing radiation available for prostate cancer, in which small seeds containing iodine-125 radioisotope are implanted directly into the prostate. The seed consists of a sealed titanium tube containing a central silver wire with adsorbed iodine-125. The tube sealing is made with titanium at the ends, using plasma arc-welding (PAW) or laser process. This sealing must be leakage-resistant and free of cracks, therefore avoiding iodine-125 to deposit in the silver wire to escape and spread into the human body. To ensure that this problem is not occurring, rigorous leakage tests in accordance with the standard ISO-9978 should be applied. The aim of this study is to determine, implement and evaluate the leakage test to be used in the iodine-125 seeds production, in order to qualify the sealing procedure. The standard ISO-9978 presents a list of tests to be carried out according to the type of source. The preferential methods for brachytherapy sources are soaking and helium. To assess the seeds leakage, the method of immersion test at room temperature was applied. The seeds are considered leakage-free if the detected activity does not exceed 185 Bq (5 nCi). An iodine standard was prepared and its value determined in a sodium iodide detector. A liquid scintillation counter was calibrated with the standard for seed leakage tests. Forty-eight seeds were plasma arc-welded for these tests. (authors)

  9. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    OpenAIRE

    Samia de Freitas Brandao; Tarcisio Passos Ribeiro de Campos

    2013-01-01

    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 int...

  10. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir; Andersen, Claus E.; Tanderup, Kari

    2014-01-01

    Purpose:This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of...... identify all false errors represented by mispositioned dosimeters contrary to an error detection algorithm relying on the original reconstruction. Conclusions:The study demonstrates that the AEDA error identification during HDR/PDR BT relies on a stable dosimeter position rather than on an accurate...... dosimeter reconstruction, and the AEDA’s capacity to distinguish between true and false error scenarios. The study further shows that the AEDA can offer guidance in decision making in the event of potential errors detected with real-time in vivo point dosimetry....

  11. Caudal epidural anesthesia during intracavitary brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    It has been suggested that pain control during intracavitary brachytherapy for cervical cancer is insufficient in most hospitals in Japan. Our hospital began using caudal epidural anesthesia during high-dose-rate (HDR) intracavitary brachytherapy in 2011. The purpose of the present study was to retrospectively investigate the effects of caudal epidural anesthesia during HDR intracavitary brachytherapy for cervical cancer patients. Caudal epidural anesthesia for 34 cervical cancer patients was performed during HDR intracavitary brachytherapy between October 2011 and August 2013. We used the patients' self-reported Numeric Rating Scale (NRS) score at the first session of HDR intracavitary brachytherapy as a subjective evaluation of pain. We compared NRS scores of the patients with anesthesia with those of 30 patients who underwent HDR intracavitary brachytherapy without sacral epidural anesthesia at our hospital between May 2010 and August 2011. Caudal epidural anesthesia succeeded in 33 patients (97%), and the NRS score was recorded in 30 patients. The mean NRS score of the anesthesia group was 5.17 ± 2.97, significantly lower than that of the control group's 6.80 ± 2.59 (P = 0.035). The caudal epidural block resulted in no side-effects. Caudal epidural anesthesia is an effective and safe anesthesia option during HDR intracavitary brachytherapy for cervical cancer. (author)

  12. Multihelix rotating shield brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    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 (D90 of HR-CTV) were the two metrics used as the basis for evaluation and

  13. 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

  14. Iridium-192 sources production for brachytherapy use

    International Nuclear Information System (INIS)

    The incidence of cancer increases every year in Brazil and turns out to be one of the most important causes of mortality. Some of the patients are treated with brachytherapy, a form of lesion treatment which is based on the insertion of sources into tumors, in this particular case, activated iridium wires. During this process, the ionizing radiation efficiently destroys the malignant cells. These iridium wires have a nucleus made out of an iridium-platinum alloy 20-30/70-80 of 0,1 mm in diameter either coated by platinum or encased in a platinum tube. The technique consists in irradiating the wire in the reactor neutron flux in order to produce iridium-192. The linear activity goes from 1 mCi/cm to 4 mCi/cm and the basic characteristic, which is required, is the homogeneity of the activation along the wire. It should not present a dispersion exceeding 5% on a wire measuring 50 cm in length, 0.5 mm or 0.3 mm in diameter. Several experiments were carried out in order to define the activation parameters. Wires from different origins were analyzed. It was concluded that United States of America and France wires were found to be perfectly adequate for brachytherapy purposes and have therefore been sent to specialized hospitals and successfully applied to cancer patients. Considering that the major purpose of this work is to make this product more accessible in Brazil, at a cost reflecting the Brazilian reality, the IPEN is promoting the preparation of iridium-192 sources to be used in brachytherapy, on a national level. (author)

  15. Perioperative interstitial brachytherapy for recurrent keloid scars

    International Nuclear Information System (INIS)

    Purpose: Evaluation of the results of perioperative interstitial brachytherapy with low dose-rate (L.D.R.) Ir-192 in the treatment of keloid scars. Patients and methods: We performed a retrospective analysis of 73 histologically confirmed keloids (from 58 patients) resistant to medico surgical treated by surgical excision plus early perioperative brachytherapy. All lesions were initially symptomatic. Local control was evaluated by clinical evaluation. Functional and cosmetic results were assessed in terms of patient responses to a self-administered questionnaire. Results: Median age was 28 years (range 13-71 years). Scars were located as follows: 37% on the face, 32% on the trunk or abdomen, 16% on the neck, and 15% on the arms or legs. The mean delay before loading was four hours (range, 1-6 h). The median dose was 20 Gy (range, 15-40 Gy). Sixty-four scars (from 53 patients) were evaluated. Local control was 86% (follow-up, 44.5 months; range, 14-150 months). All relapses occurred early within 2 years posttreatment. At 20 months, survival without recurrence was significantly lower when treated lengths were more than 6 cm long. The rate was 100% for treated scars below 4.5 cm in length, 95% (95% CI: 55-96) for those 4.5-6 cm long, and 75% (95% CI: 56-88) beyond 6 cm (p = 0.038). Of the 35 scars (28 patients) whose results were reassessed, six remained symptomatic and the esthetic results were considered to be good in 51% (18/35) and average in 37% (13/35) (median follow-up, 70 months; range, 16-181 months). Conclusion: Early perioperative L.D.R. brachytherapy delivering 20 Gy at 5 mm reduced the rate of recurrent keloids resistant to other treatments and gave good functional results. (authors)

  16. Stereotactic interstitial brachytherapy for the treatment of oligodendroglial brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    El Majdoub, Faycal; Neudorfer, Clemens; Maarouf, Mohammad [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University of Witten/Herdecke, Department of Stereotaxy and Functional Neurosurgery, Center of Neurosurgery, Cologne-Merheim Medical Center (CMMC), Cologne (Germany); Blau, Tobias; Deckert, Martina [University Hospital of Cologne, Department of Neuropathology, Cologne (Germany); Hellmich, Martin [University Hospital of Cologne, Institute of Statistics, Informatics and Epidemiology, Cologne (Germany); Buehrle, Christian [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Sturm, Volker [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University Hospital of Wurzburg, Department of Neurosurgery, Wuerzburg (Germany)

    2015-12-15

    We evaluated the treatment of oligodendroglial brain tumors with interstitial brachytherapy (IBT) using {sup 125}iodine seeds ({sup 125}I) and analyzed prognostic factors. Between January 1991 and December 2010, 63 patients (median age 43.3 years, range 20.8-63.4 years) suffering from oligodendroglial brain tumors were treated with {sup 125}I IBT either as primary, adjuvantly after incomplete resection, or as salvage therapy after tumor recurrence. Possible prognostic factors influencing disease progression and survival were retrospectively investigated. The actuarial 2-, 5-, and 10-year overall and progression-free survival rates after IBT for WHO II tumors were 96.9, 96.9, 89.8 % and 96.9, 93.8, 47.3 %; for WHO III tumors 90.3, 77, 54.9 % and 80.6, 58.4, 45.9 %, respectively. Magnetic resonance imaging demonstrated complete remission in 2 patients, partial remission in 13 patients, stable disease in 17 patients and tumor progression in 31 patients. Median time to progression for WHO II tumors was 87.6 months and for WHO III tumors 27.8 months. Neurological status improved in 10 patients and remained stable in 20 patients, while 9 patients deteriorated. There was no treatment-related mortality. Treatment-related morbidity was transient in 11 patients. WHO II, KPS ≥ 90 %, frontal location, and tumor surface dose > 50 Gy were associated with increased overall survival (p ≤ 0.05). Oligodendroglioma and frontal location were associated with a prolonged progression-free survival (p ≤ 0.05). Our study indicates that IBT achieves local control rates comparable to surgery and radio-/chemotherapy treatment, is minimally invasive, and safe. Due to the low rate of side effects, IBT may represent an attractive option as part of a multimodal treatment schedule, being supplementary to microsurgery or as a salvage therapy after chemotherapy and conventional irradiation. (orig.) [German] Die Behandlung oligodendroglialer Hirntumoren durch die interstitielle Brachytherapie

  17. Experiences with alanine dosimetry in afterloading brachytherapy

    International Nuclear Information System (INIS)

    At the present, the most commonly used dosimetry for radiotherapy applications are ionisation chambers and thermoluminescent dosimeters (TLD). However, there are some undesirable characteristics of these dosimetry systems, such as large detection volume (ionisation chamber) as well as fading of the radiation induced signal with time and destructive readout (TLG). The present study is an investigation into the use of the alanine/ESR dosimetry in fractionated afterloading brachytherapy during the whole radiotherapy course. There are some qualities which make alanine dosimetry attractive. These are the linear energy response, low fading under standard conditions, and the nondestructive readout. Thus the alanine dosimetry makes possible cumulative dose measurements during the radiotherapy course and an archival storage. By ionizing radiation (gamma, e, n, p, charged particles) free radicals (unpaired electrons) are produced in the amino acid alanine. The continuous wave electron spin resonance (ESR) spectroscopy is used to determine the number of free radicals, which is proportional to the absorbed dose and the alanine content of the dosimeter. The ESR measurements were made at room temperature using a Bruker EPR analyzer EMS-104. The dosimeters used in the test are alanine pellets (23.72 mg weight, 4.9 mm diameter, 1 mm height) as well as flexible alanine film dosimeters (thickness about 500 μm). The dosimeters consist of a blend of L-alpha-alanine and a binder. The alanine content of the pellets and the film dosimeters is about 88 % and 50 % by weight, respectively. The dosimeters for the calculation of the dose-effect-relationship were irradiated at the Physical-Technical Bundesanstalt in Braunschweig by a standard 60Co source. The maximum deviation from the calculated linear function is about 0.12 Gy in the dose range up to 80 Gy. The goal of medical applications was the superficial dose measurement in afterloading brachytherapy during the radiotherapy course in

  18. 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

  19. Stereotactic interstitial brachytherapy for the treatment of oligodendroglial brain tumors

    International Nuclear Information System (INIS)

    We evaluated the treatment of oligodendroglial brain tumors with interstitial brachytherapy (IBT) using 125iodine seeds (125I) and analyzed prognostic factors. Between January 1991 and December 2010, 63 patients (median age 43.3 years, range 20.8-63.4 years) suffering from oligodendroglial brain tumors were treated with 125I IBT either as primary, adjuvantly after incomplete resection, or as salvage therapy after tumor recurrence. Possible prognostic factors influencing disease progression and survival were retrospectively investigated. The actuarial 2-, 5-, and 10-year overall and progression-free survival rates after IBT for WHO II tumors were 96.9, 96.9, 89.8 % and 96.9, 93.8, 47.3 %; for WHO III tumors 90.3, 77, 54.9 % and 80.6, 58.4, 45.9 %, respectively. Magnetic resonance imaging demonstrated complete remission in 2 patients, partial remission in 13 patients, stable disease in 17 patients and tumor progression in 31 patients. Median time to progression for WHO II tumors was 87.6 months and for WHO III tumors 27.8 months. Neurological status improved in 10 patients and remained stable in 20 patients, while 9 patients deteriorated. There was no treatment-related mortality. Treatment-related morbidity was transient in 11 patients. WHO II, KPS ≥ 90 %, frontal location, and tumor surface dose > 50 Gy were associated with increased overall survival (p ≤ 0.05). Oligodendroglioma and frontal location were associated with a prolonged progression-free survival (p ≤ 0.05). Our study indicates that IBT achieves local control rates comparable to surgery and radio-/chemotherapy treatment, is minimally invasive, and safe. Due to the low rate of side effects, IBT may represent an attractive option as part of a multimodal treatment schedule, being supplementary to microsurgery or as a salvage therapy after chemotherapy and conventional irradiation. (orig.)

  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. Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part I. Electronic brachytherapy source

    International Nuclear Information System (INIS)

    Purpose: Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR)192Ir sources, as well as electronic brachytherapy sources. Part I of this paper will discuss the applicators used with electronic brachytherapy sources; Part II will discuss those used with HDR 192Ir sources. Although the use of these applicators has gained in popularity, the dosimetric characteristics including depth dose and surface dose distributions have not been independently verified. Additionally, there is no recognized method of output verification for quality assurance procedures with applicators like these. Existing dosimetry protocols available from the AAPM bookend the cross-over characteristics of a traditional brachytherapy source (as described by Task Group 43) being implemented as a low-energy superficial x-ray beam (as described by Task Group 61) as observed with the surface applicators of interest. Methods: This work aims to create a cohesive method of output verification that can be used to determine the dose at the treatment surface as part of a quality assurance/commissioning process for surface applicators used with HDR electronic brachytherapy sources (Part I) and192Ir sources (Part II). Air-kerma rate measurements for the electronic brachytherapy sources were completed with an Attix Free-Air Chamber, as well as several models of small-volume ionization chambers to obtain an air-kerma rate at the treatment surface for each applicator. Correction factors were calculated using MCNP5 and EGSnrc Monte Carlo codes in order to determine an applicator-specific absorbed dose to water at the treatment surface from the measured air-kerma rate. Additionally, relative dose

  2. Post-operative treatment of malignant salivary gland tumours of the palate with iodine-125 brachytherapy

    International Nuclear Information System (INIS)

    Background and purpose: Malignant minor salivary gland tumours are usually small and clinically indistinguishable from benign lesions. Surgery is the treatment of choice with post-operative radiotherapy for involved margins or unfavourable histology. We assessed the results of a series of such patients treated with iodine-125 brachytherapy in the form of a temporary applicator or implant. Patients and methods: There were nine patients with T1/T2 tumours of the hard and/or soft palate that had been excised. All had close or involved margins. Six were treated with a dental applicator alone, two with an applicator and additional I-125 seeds in tubes and one with an implant alone. The applicator consists of two layers of plastic made from a dental impression enclosing a predetermined number of I-125 seeds, 9-39, glued to one surface and a layer of ash metal to protect the tongue. It was inserted 1-3 months post-operatively and delivered 35-62 Gy, median 56 Gy, at 5-7 mm depth over 58-156 h, median 120 h, at 0.26-0.67 Gy/h, median 0.45 Gy/h. Results: The patients have been followed up for 32-158 months, median 50 months, and there were no recurrences. The applicator was well tolerated. A confluent mucositis developed which lasted 3-4 weeks. One patient developed a mucosal ulcer which healed spontaneously. Conclusions: Brachytherapy is an effective way of delivering post-operative radiotherapy to the hard and soft palate in patients with malignant salivary gland tumours that have been incompletely excised or have unfavourable histology. Local control is excellent, treatment time is short and morbidity is minimal

  3. Metallic artifact mitigation and organ-constrained tissue assignment for Monte Carlo calculations of permanent implant lung brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J. G. H.; Miksys, N.; Thomson, R. M., E-mail: rthomson@physics.carleton.ca [Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Furutani, K. M. [Department of Radiation Oncology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905 (United States)

    2014-01-15

    Purpose: To investigate methods of generating accurate patient-specific computational phantoms for the Monte Carlo calculation of lung brachytherapy patient dose distributions. Methods: Four metallic artifact mitigation methods are applied to six lung brachytherapy patient computed tomography (CT) images: simple threshold replacement (STR) identifies high CT values in the vicinity of the seeds and replaces them with estimated true values; fan beam virtual sinogram replaces artifact-affected values in a virtual sinogram and performs a filtered back-projection to generate a corrected image; 3D median filter replaces voxel values that differ from the median value in a region of interest surrounding the voxel and then applies a second filter to reduce noise; and a combination of fan beam virtual sinogram and STR. Computational phantoms are generated from artifact-corrected and uncorrected images using several tissue assignment schemes: both lung-contour constrained and unconstrained global schemes are considered. Voxel mass densities are assigned based on voxel CT number or using the nominal tissue mass densities. Dose distributions are calculated using the EGSnrc user-code BrachyDose for{sup 125}I, {sup 103}Pd, and {sup 131}Cs seeds and are compared directly as well as through dose volume histograms and dose metrics for target volumes surrounding surgical sutures. Results: Metallic artifact mitigation techniques vary in ability to reduce artifacts while preserving tissue detail. Notably, images corrected with the fan beam virtual sinogram have reduced artifacts but residual artifacts near sources remain requiring additional use of STR; the 3D median filter removes artifacts but simultaneously removes detail in lung and bone. Doses vary considerably between computational phantoms with the largest differences arising from artifact-affected voxels assigned to bone in the vicinity of the seeds. Consequently, when metallic artifact reduction and constrained tissue

  4. BrachyView, a novel in-body imaging system for HDR prostate brachytherapy: Experimental evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Safavi-Naeini, M.; Han, Z.; Alnaghy, S.; Cutajar, D.; Petasecca, M.; Lerch, M. L. F.; Rosenfeld, A. B., E-mail: anatoly@uow.edu.au [Centre for Medical Radiation Physics, University of Wollongong, Wollongong 2522 (Australia); Franklin, D. R. [Faculty of Engineering and Information Technology, University of Technology, Sydney 2007 (Australia); Bucci, J. [St George Hospital Cancer Care Centre, Kogarah 2217 (Australia); Carrara, M. [Fondazione IRCCS Istituto Nazionale dei Tumori, Milan 20133 (Italy); Zaider, M. [Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States)

    2015-12-15

    Purpose: This paper presents initial experimental results from a prototype of high dose rate (HDR) BrachyView, a novel in-body source tracking system for HDR brachytherapy based on a multipinhole tungsten collimator and a high resolution pixellated silicon detector array. The probe and its associated position estimation algorithms are validated and a comprehensive evaluation of the accuracy of its position estimation capabilities is presented. Methods: The HDR brachytherapy source is moved through a sequence of positions in a prostate phantom, for various displacements in x, y, and z. For each position, multiple image acquisitions are performed, and source positions are reconstructed. Error estimates in each dimension are calculated at each source position and combined to calculate overall positioning errors. Gafchromic film is used to validate the accuracy of source placement within the phantom. Results: More than 90% of evaluated source positions were estimated with an error of less than one millimeter, with the worst-case error being 1.3 mm. Experimental results were in close agreement with previously published Monte Carlo simulation results. Conclusions: The prototype of HDR BrachyView demonstrates a satisfactory level of accuracy in its source position estimation, and additional improvements are achievable with further refinement of HDR BrachyView’s image processing algorithms.

  5. BrachyView, a novel in-body imaging system for HDR prostate brachytherapy: Experimental evaluation

    International Nuclear Information System (INIS)

    Purpose: This paper presents initial experimental results from a prototype of high dose rate (HDR) BrachyView, a novel in-body source tracking system for HDR brachytherapy based on a multipinhole tungsten collimator and a high resolution pixellated silicon detector array. The probe and its associated position estimation algorithms are validated and a comprehensive evaluation of the accuracy of its position estimation capabilities is presented. Methods: The HDR brachytherapy source is moved through a sequence of positions in a prostate phantom, for various displacements in x, y, and z. For each position, multiple image acquisitions are performed, and source positions are reconstructed. Error estimates in each dimension are calculated at each source position and combined to calculate overall positioning errors. Gafchromic film is used to validate the accuracy of source placement within the phantom. Results: More than 90% of evaluated source positions were estimated with an error of less than one millimeter, with the worst-case error being 1.3 mm. Experimental results were in close agreement with previously published Monte Carlo simulation results. Conclusions: The prototype of HDR BrachyView demonstrates a satisfactory level of accuracy in its source position estimation, and additional improvements are achievable with further refinement of HDR BrachyView’s image processing algorithms

  6. Study and parameters survey for iodine-125 source dosimetry to be applied in brachytherapy

    International Nuclear Information System (INIS)

    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)

  7. Study and development of methodology for radioactive iodine fixation in polymeric substrate for manufacturing sources used in brachytherapy

    International Nuclear Information System (INIS)

    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

  8. The Activity Check of Brachytherapy Isotope

    International Nuclear Information System (INIS)

    An isotope Ir-192, which is used in brachytherapy depends on import in whole quantities. There are a few ways for its activity. measurement using Welltype chamber or the way to rely on authentic decay table of manufacturer. In-air dosimetry using Farmer Chamber, etc. In this paper, let me introduce the way using Farmer chamber which is easier and simple. With the Farmer chamber and source calibration jig, take a measurement the activity of an isotope Ir-192 and compare the value with the value from decay table of manufacturer and check the activity of source. The result of measurement, compared the value from decay table, by ±2.1. (which belongs to recommendable value for AAPM ±5% as difference of error range). It is possible to use on clinical medicine. With the increase in use of brachytherapy, the increase of import is essential. And an accurate activity check of source is compulsory. For the activity check of source, it was possible to use Farmer chamber and source calibration jig without additional purchase of Well type chamber.

  9. Samarium-145: a new brachytherapy source

    International Nuclear Information System (INIS)

    A new radiation source has been produced for brachytherapy, with radiation energies slightly above those of 125I, and a Tsub(1/2) of 340 d. This source, 145Sm, is produced by neutron irradiation of 144Sm (96.5% enriched). Decay is by electron capture with 140 K x-rays per 100 disintergrations in the energy region between 38-45 keV, plus 13 γ-rays at 61 keV. These sources are encapsulated in Ti tubes, approx. 0.8 mm x 4.5 mm, and have been developed for temporary implantation in brain and ocular tumours. The 38-61 keV photons should make such sources easy to shield, while providing a dose distribution from source arrays somewhat more homogeneous than that from 125I. In addition, the 340 d half life of 145Sm permits its use for times significantly longer than that of 60 d 125I. While the 145Sm sources have been designed primarily for implantation in a brain tumour, they should be useful for almost any conventional brachytherapy application. (author)

  10. Implementation of three-dimensional planning in brachytherapy of high dose rate for gynecology therapies

    International Nuclear Information System (INIS)

    This work aims to implement the three-dimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators do not have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the license's library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D2cc and ICRUBladder dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D2cc was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D2cc and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D2cc for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the implementation of a viable brachytherapy 3

  11. 125iodine brachytherapy for colorectal adenocarcinoma recurrent in the pelvis and paraortics

    International Nuclear Information System (INIS)

    Purpose: To evaluate the results of 125I brachytherapy in colorectal cancers recurrent in the pelvis and paraortics. Methods and Materials: From September 1989 to January 1997, 29 patients with colorectal adenocarcinoma recurrent in the pelvis or the paraortic nodes were treated intraoperatively with permanent 125iodine seed implantation at the James Cancer Center of The Ohio State University (OSU). All patients had undergone prior surgery; 72% had prior EBRT. The implanted residual tumor volume was microscopic in 38% and gross in 62%. The implanted area (median 25 cc) received a median minimal peripheral dose of 140 Gy to total decay. An omental pedicle was used to minimize irradiation of the bowel. Five patients received additional postimplant EBRT (20-50 Gy; median 30 Gy). Results: The 1-, 2-, and 4-year actuarial local-regional control rates were 38%, 17%, and 17%, respectively, with a median time to local failure of 11 months (95% CI 10-12 months). The first manifestation of disease progression in 52% of the patients was local-regional. In addition, 22 patients (75%) developed distant metastases. The 1-, 2-, and 4-year actuarial overall survival rates were 70%, 35%, and 21%, (median = 18 months; 95% CI: 14-22 months). Overall survival was better for patients smaller volume implants (p = 0.007), with a lower total activity implanted (p = 0.0003), with a smaller number of implanted sites (p = 0.004), and with microscopic residual disease (p = 0.01). Patients receiving additional EBRT also had a better prognosis (p = 0.005). Local tumor progression was the cause of death in 34% of the patients who have died at the time of this report and 56% died of distant metastases. Of the patients, 13 (45%) experienced 15 toxic events, including 3 patients (10%) with enteric fistula. Neuropathy was not observed. Conclusions: 125I brachytherapy can be successfully used for salvage in patients with recurrent colorectal cancer. Patients with isolated, microscopic, or minimal

  12. Project SEED.

    Science.gov (United States)

    Chemical and Engineering News, 1986

    1986-01-01

    Reports on Project SEED (Summer Educational Experience for the Disadvantaged) a project in which high school students from low-income families work in summer jobs in a variety of academic, industrial, and government research labs. The program introduces the students to career possibilities in chemistry and to the advantages of higher education.…

  13. Manual on brachytherapy. Incorporating: Applications guide, procedures guide, basics guide

    International Nuclear Information System (INIS)

    In addition to a basic guide to the principles of the production of ionizing radiation and to methods of radiation protection and dosimetry, this booklet includes information about radiation protection procedures for brachytherapy

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

    International Nuclear Information System (INIS)

    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

  15. Nursing intervention in gynecologic brachytherapy under general anesthesia

    International Nuclear Information System (INIS)

    We reconsidered our nursing intervention in gynecologic intracavitary brachytherapy as general anesthesia was introduced. We recognized that safety, comfort, privacy protection and relief of anxiety of the patients were important points for nursing with corporation of other medical staffs. (author)

  16. 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.

  17. 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.

  18. 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...

  19. Brachytherapy. Pulsed dose rate brachytherapy - Radiation protection: medical sheet ED 4250

    International Nuclear Information System (INIS)

    After having indicated the required authorization to implement brachytherapy techniques, this document presents the various aspects and measures related to radiation protection when performing pulsed-dose-rate brachytherapy treatments. It presents the concerned personnel, describes the operational process, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks (biological risk, handling and posture, handling of heavy loads, mental workload, chemical risk)

  20. Use of alpha-1 adrenoceptor antagonists in patients who underwent low-dose-rate brachytherapy for prostate cancer - a randomized controlled trial of silodosin versus naftopidil -

    International Nuclear Information System (INIS)

    To evaluate the effect of two different alpha-1 adrenoceptor antagonists on lower urinary tract symptoms in patients who underwent LDR-brachytherapy. A total of 141 patients who had been clinically diagnosed with localized prostate cancer and underwent LDR-brachytherapy were enrolled. Patients were randomized and allocated to two groups (silodosin 8 mg vs. naftopidil 75 mg). The primary endpoint was a change in the international prostate symptom score (IPSS) at 3 months after seed implantation. Secondary endpoints included the recovery rate of IPSS at 12 months after seed implantation, the change in IPSS and overactive bladder symptom score, uroflowmetric parameters, and frequency volume chart (FVC). To determine independent variables that can predict IPSS recovery, logistic regression analysis was carried out. The mean change in the IPSS at 3 months after seed implantation in both groups was ⊿10.6 (naftopidil) and ⊿10.4 (silodosin), respectively. There was not a significant difference between the two groups (p=0.728). An increase in urinary frequency and a decrease in total urinated volume and mean voided volume were observed in FVC for 12 months after seed implantation. Multivariate analysis revealed that the urethral dose (UD30) was an independent predictive parameter of IPSS recovery. Patients with UD30 < 200Gy showed a higher recovery rate of IPSS at 12 months after seed implantation. There was no significant difference of serial change in IPSS between silodosin and naftopidil during the first year after seed implantation. A lower dose on the urethra was an independent predictor of IPSS recovery at 12 months after seed implantation

  1. HDR brachytherapy with surface applicators: technical considerations and dosimetry.

    Science.gov (United States)

    Sabbas, Albert M; Kulidzhanov, Fridon G; Presser, Joseph; Hayes, Mary K; Nori, Dattatreyudu

    2004-06-01

    HDR surface molds offer an alternative radiotherapy modality to electrons for the treatment of skin lesions. Treatment planning and dosimetry are discussed for two types of surface molds used in our clinic. Standard rectangular applicators are used on a variety of sites where surface curvature is minimal. In these cases an idealized planar geometry is used for treatment planning dose calculations. The calculations yield treatment dose uniformity at the prescription depth in tissue as well as skin dose, as a percentage of the treatment dose, and its dose uniformity. The availability of optimization techniques results in superior dose uniformity at depth but the dose at the skin has to be carefully evaluated. We have studied the dependence of these dosimetric parameters on the size of the surface mold and the type of optimization procedure used in the dosimetry calculations. The second type of surface applicator involves the use of a customized silicone rubber mold attached to a thermoplastic mask of the patient. We have used them to treat lesions of the face where surface curvatures are appreciable and reproducibility of setup is more critical. In these cases a CT data set is used for reconstruction of the catheters, activation of relevant dwell positions and dosimetry, including optimization. Towards establishing effective methods for quality assurance of the optimized HDR surface mold planning calculations, we have compared their dosimetry to both a classical brachytherapy system and to one based on an analytical model of the applicator. The classical system yields an independent verification of the integrated activity used in the planning calculations, whereas the analytical model is used to evaluate depth dose dependence on mold size and optimization. PMID:15161319

  2. The investigation of prostatic calcifications using μ-PIXE analysis and their dosimetric effect in low dose rate brachytherapy treatments using Geant4

    Science.gov (United States)

    Pope, D. J.; Cutajar, D. L.; George, S. P.; Guatelli, S.; Bucci, J. A.; Enari, K. E.; Miller, S.; Siegele, R.; Rosenfeld, A. B.

    2015-06-01

    Low dose rate brachytherapy is a widely used modality for the treatment of prostate cancer. Most clinical treatment planning systems currently in use approximate all tissue to water, neglecting the existence of inhomogeneities, such as calcifications. The presence of prostatic calcifications may perturb the dose due to the higher photoelectric effect cross section in comparison to water. This study quantitatively evaluates the effect of prostatic calcifications on the dosimetric outcome of brachytherapy treatments by means of Monte Carlo simulations and its potential clinical consequences. Four pathological calcification samples were characterised with micro-particle induced x-ray emission (μ-PIXE) to determine their heavy elemental composition. Calcium, phosphorus and zinc were found to be the predominant heavy elements in the calcification composition. Four clinical patient brachytherapy treatments were modelled using Geant4 based Monte Carlo simulations, in terms of the distribution of brachytherapy seeds and calcifications in the prostate. Dose reductions were observed to be up to 30% locally to the calcification boundary, calcification size dependent. Single large calcifications and closely placed calculi caused local dose reductions of between 30-60%. Individual calculi smaller than 0.5 mm in diameter showed minimal dosimetric impact, however, the effects of small or diffuse calcifications within the prostatic tissue could not be determined using the methods employed in the study. The simulation study showed a varying reduction on common dosimetric parameters. D90 showed a reduction of 2-5%, regardless of calcification surface area and volume. The parameters V100, V150 and V200 were also reduced by as much as 3% and on average by 1%. These reductions were also found to relate to the surface area and volume of calcifications, which may have a significant dosimetric impact on brachytherapy treatment, however, such impacts depend strongly on specific factors

  3. The investigation of prostatic calcifications using μ-PIXE analysis and their dosimetric effect in low dose rate brachytherapy treatments using Geant4

    International Nuclear Information System (INIS)

    Low dose rate brachytherapy is a widely used modality for the treatment of prostate cancer. Most clinical treatment planning systems currently in use approximate all tissue to water, neglecting the existence of inhomogeneities, such as calcifications. The presence of prostatic calcifications may perturb the dose due to the higher photoelectric effect cross section in comparison to water. This study quantitatively evaluates the effect of prostatic calcifications on the dosimetric outcome of brachytherapy treatments by means of Monte Carlo simulations and its potential clinical consequences.Four pathological calcification samples were characterised with micro-particle induced x-ray emission (μ-PIXE) to determine their heavy elemental composition. Calcium, phosphorus and zinc were found to be the predominant heavy elements in the calcification composition. Four clinical patient brachytherapy treatments were modelled using Geant4 based Monte Carlo simulations, in terms of the distribution of brachytherapy seeds and calcifications in the prostate. Dose reductions were observed to be up to 30% locally to the calcification boundary, calcification size dependent. Single large calcifications and closely placed calculi caused local dose reductions of between 30–60%. Individual calculi smaller than 0.5 mm in diameter showed minimal dosimetric impact, however, the effects of small or diffuse calcifications within the prostatic tissue could not be determined using the methods employed in the study. The simulation study showed a varying reduction on common dosimetric parameters. D90 showed a reduction of 2–5%, regardless of calcification surface area and volume. The parameters V100, V150 and V200 were also reduced by as much as 3% and on average by 1%. These reductions were also found to relate to the surface area and volume of calcifications, which may have a significant dosimetric impact on brachytherapy treatment, however, such impacts depend strongly on specific

  4. Dosimetry and treatment planning of Occu-Prosta I-125 seeds for intraocular lesions

    OpenAIRE

    Chaudhari Suresh; Deshpande Sudesh; Anand Vivek; Sandeep; Saxena Sanjay; Dash A; Basu Mahua; Samant Preetam; Kannan V

    2008-01-01

    Intraocular malignant lesions are frequently encountered in clinical practice. Plaque brachytherapy represents an effective means of treatment for intraocular lesions. Recently Radiopharmaceutical Division, BARC, Mumbai, has indigenously fabricated reasonable-cost I-125 sources. Here we are presenting the preliminary experience of dosimetry of sources, configuration of treatment planning system (TPS) and quality assurance (QA) for eye plaque therapy with Occu-Prosta I-125 seeds, treated in ou...

  5. CT-guided 125I brachytherapy for mediastinal metastatic lymph nodes recurrence from esophageal carcinoma: Effectiveness and safety in 16 patients

    International Nuclear Information System (INIS)

    Objectives: To retrospectively evaluate effectiveness and safety of CT-guided 125I brachytherapy in 16 patients with mediastinal metastatic lymph nodes recurrence from esophageal carcinoma. Materials and methods: Sixteen metastatic lymph nodes in 16 patients were percutaneously treated in 19 125I brachytherapy sessions. Each metastatic lymph node was treated with computed tomographic (CT) guidance. Follow-up contrast material-enhanced CT or positron emission tomographic (PET) scans were reviewed and the treatment's effectiveness was evaluated. Results: Months are counted from the first time of 125I brachytherapy and the median duration of follow-up was 11 months (range, 5–16 months). The local control rates after 3, 6, 10 and 15 months were 75.0, 50.0, 42.9 and 33.3% respectively. At the time of writing, four patients are alive without evidence of recurrence at 16, 9, 16 and 9 months. The 4 patients presented good control of local tumor and no systemic recurrence, and survived throughout the follow-up period. The other 12 patients died of multiple hematogenous metastases 5–15 months after brachytherapy. A small amount of local hematoma occurred in 2 patients that involved applicator insertion through the lung. Two patients presented pneumothorax with pulmonary compression of 30 and 40% after the procedure and recovered after drainage. One patient had minor displacement of radioactive seeds. Severe complications such as massive bleeding and radiation pneumonitis did not occur. Conclusion: 125I radioactive seed implantation is effective and may be safely applied to mediastinal metastatic lymph nodes recurrence from esophageal carcinoma

  6. CT-guided {sup 125}I brachytherapy for mediastinal metastatic lymph nodes recurrence from esophageal carcinoma: Effectiveness and safety in 16 patients

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Fei, E-mail: gaof@sysucc.org.cn [State Key Laboratory of Oncology in South China, Guangzhou 510060 (China); Department of Interventional Radiology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060 (China); Li, Chuanxing, E-mail: licx@sysucc.org.cn [State Key Laboratory of Oncology in South China, Guangzhou 510060 (China); Department of Interventional Radiology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060 (China); Gu, Yangkui, E-mail: guyk@sysucc.org.cn [State Key Laboratory of Oncology in South China, Guangzhou 510060 (China); Department of Interventional Radiology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060 (China); Huang, Jinhua, E-mail: huangjh@sysucc.org.cn [State Key Laboratory of Oncology in South China, Guangzhou 510060 (China); Department of Interventional Radiology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060 (China); Wu, Peihong, E-mail: vivian-link@163.com [State Key Laboratory of Oncology in South China, Guangzhou 510060 (China); Department of Interventional Radiology, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Guangzhou 510060 (China)

    2013-02-15

    Objectives: To retrospectively evaluate effectiveness and safety of CT-guided {sup 125}I brachytherapy in 16 patients with mediastinal metastatic lymph nodes recurrence from esophageal carcinoma. Materials and methods: Sixteen metastatic lymph nodes in 16 patients were percutaneously treated in 19 {sup 125}I brachytherapy sessions. Each metastatic lymph node was treated with computed tomographic (CT) guidance. Follow-up contrast material-enhanced CT or positron emission tomographic (PET) scans were reviewed and the treatment's effectiveness was evaluated. Results: Months are counted from the first time of {sup 125}I brachytherapy and the median duration of follow-up was 11 months (range, 5–16 months). The local control rates after 3, 6, 10 and 15 months were 75.0, 50.0, 42.9 and 33.3% respectively. At the time of writing, four patients are alive without evidence of recurrence at 16, 9, 16 and 9 months. The 4 patients presented good control of local tumor and no systemic recurrence, and survived throughout the follow-up period. The other 12 patients died of multiple hematogenous metastases 5–15 months after brachytherapy. A small amount of local hematoma occurred in 2 patients that involved applicator insertion through the lung. Two patients presented pneumothorax with pulmonary compression of 30 and 40% after the procedure and recovered after drainage. One patient had minor displacement of radioactive seeds. Severe complications such as massive bleeding and radiation pneumonitis did not occur. Conclusion: {sup 125}I radioactive seed implantation is effective and may be safely applied to mediastinal metastatic lymph nodes recurrence from esophageal carcinoma.

  7. Parameterization of brachytherapy source phase space file for Monte Carlo-based clinical brachytherapy dose calculation

    International Nuclear Information System (INIS)

    A common approach to implementing the Monte Carlo method for the calculation of brachytherapy radiation dose deposition is to use a phase space file containing information on particles emitted from a brachytherapy source. However, the loading of the phase space file during the dose calculation consumes a large amount of computer random access memory, imposing a higher requirement for computer hardware. In this study, we propose a method to parameterize the information (e.g., particle location, direction and energy) stored in the phase space file by using several probability distributions. This method was implemented for dose calculations of a commercial Ir-192 high dose rate source. Dose calculation accuracy of the parameterized source was compared to the results observed using the full phase space file in a simple water phantom and in a clinical breast cancer case. The results showed the parameterized source at a size of 200 kB was as accurate as the phase space file represented source of 1.1 GB. By using the parameterized source representation, a compact Monte Carlo job can be designed, which allows an easy setup for parallel computing in brachytherapy planning. (paper)

  8. Parameterization of brachytherapy source phase space file for Monte Carlo-based clinical brachytherapy dose calculation

    Science.gov (United States)

    Zhang, M.; Zou, W.; Chen, T.; Kim, L.; Khan, A.; Haffty, B.; Yue, N. J.

    2014-01-01

    A common approach to implementing the Monte Carlo method for the calculation of brachytherapy radiation dose deposition is to use a phase space file containing information on particles emitted from a brachytherapy source. However, the loading of the phase space file during the dose calculation consumes a large amount of computer random access memory, imposing a higher requirement for computer hardware. In this study, we propose a method to parameterize the information (e.g., particle location, direction and energy) stored in the phase space file by using several probability distributions. This method was implemented for dose calculations of a commercial Ir-192 high dose rate source. Dose calculation accuracy of the parameterized source was compared to the results observed using the full phase space file in a simple water phantom and in a clinical breast cancer case. The results showed the parameterized source at a size of 200 kB was as accurate as the phase space file represented source of 1.1 GB. By using the parameterized source representation, a compact Monte Carlo job can be designed, which allows an easy setup for parallel computing in brachytherapy planning.

  9. Complementary method of analyzing the quality of the implant I-125 seeds for prostate brachytherapy using ultrasound imaging post-implant; Metodo complementario de analisis de la calidad del implante de semillas de I-125 para braquiterapia de prostata mediante la adquisicion de imagenes ecograficas post-implante

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Dominguez, M.; Carrasco Herrera, M.; Baeza Trujillo, M.; Herrador Cordoba, M.

    2011-07-01

    In this paper we propose a complementary method based on Longitudinal mode ultrasound images acquired the same day of surgery, at the end of the implant. This option will allow us to evaluate the dosimetry end of treatment with the patient in the same position he was planning and to the rectum and bladder just as full. This will permit the identification of bodies and the seeds of interest more easily and will have a reference with which to compare one month later, when the CT images can also detect whether there has been some migration.

  10. Intraluminal brachytherapy in the treatment of bile duct carcinoma

    International Nuclear Information System (INIS)

    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)

  11. Penile reconstruction

    OpenAIRE

    Garaffa, Giulio; Sansalone, Salvatore; Ralph, David J.

    2012-01-01

    During the most recent years, a variety of new techniques of penile reconstruction have been described in the literature. This paper focuses on the most recent advances in male genital reconstruction after trauma, excision of benign and malignant disease, in gender reassignment surgery and aphallia with emphasis on surgical technique, cosmetic and functional outcome.

  12. Penile reconstruction

    Institute of Scientific and Technical Information of China (English)

    Giulio Garaffa; Salvatore Sansalone; David J Ralph

    2013-01-01

    During the most recent years,a variety of new techniques of penile reconstruction have been described in the literature.This paper focuses on the most recent advances in male genital reconstruction after trauma,excision of benign and malignant disease,in gender reassignment surgery and aphallia with emphasis on surgical technique,cosmetic and functional outcome.

  13. Predictors of Metastatic Disease After Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To identify predictors of metastatic disease after brachytherapy treatment for prostate cancer. Methods and Materials: All patients who received either brachytherapy alone (implant) or brachytherapy in combination with external beam radiation therapy for treatment of localized prostate cancer at The Mount Sinai Hospital between June 1990 and March 2007 with a minimum follow-up of 2 years were included. Univariate and multivariable analyses were performed on the following variables: risk group, Gleason score (GS), clinical T stage, pretreatment prostate-specific antigen level, post-treatment prostate-specific antigen doubling time (PSA-DT), treatment type (implant vs. implant plus external beam radiation therapy), treatment era, total biological effective dose, use of androgen deprivation therapy, age at diagnosis, and race. PSA-DT was analyzed in the following ordinate groups: 0 to 90 days, 91 to 180 days, 180 to 360 days, and greater than 360 days. Results: We included 1,887 patients in this study. Metastases developed in 47 of these patients. The 10-year freedom from distant metastasis (FFDM) rate for the entire population was 95.1%. Median follow-up was 6 years (range, 2–15 years). The only two significant predictors of metastatic disease by multivariable analyses were GS and PSA-DT (p < 0.001 for both variables). Estimated 10-year FFDM rates for GS of 6 or less, GS of 7, and GS of 8 or greater were 97.9%, 94.3%, and 76.1%, respectively (p < 0.001). Estimated FFDM rates for PSA-DT of 0 to 90 days, 91 to 180 days, 181 to 360 days, and greater than 360 days were 17.5%, 67.9%, 74%, and 94.8%, respectively (p < 0.001). Estimated 10-year FFDM rates for the low-, intermediate-, and high-risk groups were 98.6%, 96.2%, and 86.7%, respectively. A demographic shift to patients presenting with higher-grade disease in more recent years was observed. Conclusions: GS and post-treatment PSA-DT are both statistically significant independent predictors of metastatic

  14. Real-time monitoring and verification of in vivo high dose rate brachytherapy using a pinhole camera

    International Nuclear Information System (INIS)

    We investigated a pinhole imaging system for independent in vivo monitoring and verification of high dose rate (HDR) brachytherapy treatment. The system consists of a high-resolution pinhole collimator, an x-ray fluoroscope, and a standard radiographic screen-film combination. Autofluoroscopy provides real-time images of the in vivo Ir-192 HDR source for monitoring the source location and movement, whereas autoradiography generates a permanent record of source positions on film. Dual-pinhole autoradiographs render stereo-shifted source images that can be used to reconstruct the source dwell positions in three dimensions. The dynamic range and spatial resolution of the system were studied with a polystyrene phantom using a range of source strengths and dwell times. For the range of source activity used in HDR brachytherapy, a 0.5 mm diameter pinhole produced sharp fluoroscopic images of the source within the dynamic range of the fluoroscope. With a source-to-film distance of 35 cm and a 400 speed screen-film combination, the same pinhole yielded well recognizable images of a 281.2 GBq (7.60 Ci) Ir-192 source for dwell times in the typical clinical range of 2 to 400 s. This 0.5 mm diameter pinhole could clearly resolve source positions separated by lateral displacements as small as 1 mm. Using a simple reconstruction algorithm, dwell positions in a phantom were derived from stereo-shifted dual-pinhole images and compared to the known positions. The agreement was better than 1 mm. A preliminary study of a patient undergoing HDR treatment for cervical cancer suggests that the imaging method is clinically feasible. Based on these studies we believe that the pinhole imaging method is capable of providing independent and reliable real-time monitoring and verification for HDR brachytherapy

  15. 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

  16. Harmony search optimization for HDR prostate brachytherapy

    Science.gov (United States)

    Panchal, Aditya

    In high dose-rate (HDR) prostate brachytherapy, multiple catheters are inserted interstitially into the target volume. The process of treating the prostate involves calculating and determining the best dose distribution to the target and organs-at-risk by means of optimizing the time that the radioactive source dwells at specified positions within the catheters. It is the goal of this work to investigate the use of a new optimization algorithm, known as Harmony Search, in order to optimize dwell times for HDR prostate brachytherapy. The new algorithm was tested on 9 different patients and also compared with the genetic algorithm. Simulations were performed to determine the optimal value of the Harmony Search parameters. Finally, multithreading of the simulation was examined to determine potential benefits. First, a simulation environment was created using the Python programming language and the wxPython graphical interface toolkit, which was necessary to run repeated optimizations. DICOM RT data from Varian BrachyVision was parsed and used to obtain patient anatomy and HDR catheter information. Once the structures were indexed, the volume of each structure was determined and compared to the original volume calculated in BrachyVision for validation. Dose was calculated using the AAPM TG-43 point source model of the GammaMed 192Ir HDR source and was validated against Varian BrachyVision. A DVH-based objective function was created and used for the optimization simulation. Harmony Search and the genetic algorithm were implemented as optimization algorithms for the simulation and were compared against each other. The optimal values for Harmony Search parameters (Harmony Memory Size [HMS], Harmony Memory Considering Rate [HMCR], and Pitch Adjusting Rate [PAR]) were also determined. Lastly, the simulation was modified to use multiple threads of execution in order to achieve faster computational times. Experimental results show that the volume calculation that was

  17. 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

  18. Balloon brachytherapy: how I do it

    International Nuclear Information System (INIS)

    To describe the technical aspects of insertion of MammoSite Radiation System, cosmetic issues, patients selection for the procedure and their satisfaction. Seventy patients underwent brachytherapy after insertion of the MammoSite catheter and received a boost HDR totaling 1500 cGy in six fractions over a three day period. Each patient then received 5 weeks of external beam radiotherapy to the whole breast. Only T1-2 patients were treated. All patients had excellent cosmetic results. The complications (minimal skin erythema, hematoma, balloon leak, seroma, were minimal. The safety and effectiveness of the MammoSite Radiation Therapy System as a replacement for whole breast irradiation in the treatment of breast cancer has not yet been established. (author)

  19. Human error in remote Afterloading Brachytherapy

    International Nuclear Information System (INIS)

    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

  20. Blob-enhanced reconstruction technique

    Science.gov (United States)

    Castrillo, Giusy; Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso

    2016-09-01

    A method to enhance the quality of the tomographic reconstruction and, consequently, the 3D velocity measurement accuracy, is presented. The technique is based on integrating information on the objects to be reconstructed within the algebraic reconstruction process. A first guess intensity distribution is produced with a standard algebraic method, then the distribution is rebuilt as a sum of Gaussian blobs, based on location, intensity and size of agglomerates of light intensity surrounding local maxima. The blobs substitution regularizes the particle shape allowing a reduction of the particles discretization errors and of their elongation in the depth direction. The performances of the blob-enhanced reconstruction technique (BERT) are assessed with a 3D synthetic experiment. The results have been compared with those obtained by applying the standard camera simultaneous multiplicative reconstruction technique (CSMART) to the same volume. Several blob-enhanced reconstruction processes, both substituting the blobs at the end of the CSMART algorithm and during the iterations (i.e. using the blob-enhanced reconstruction as predictor for the following iterations), have been tested. The results confirm the enhancement in the velocity measurements accuracy, demonstrating a reduction of the bias error due to the ghost particles. The improvement is more remarkable at the largest tested seeding densities. Additionally, using the blobs distributions as a predictor enables further improvement of the convergence of the reconstruction algorithm, with the improvement being more considerable when substituting the blobs more than once during the process. The BERT process is also applied to multi resolution (MR) CSMART reconstructions, permitting simultaneously to achieve remarkable improvements in the flow field measurements and to benefit from the reduction in computational time due to the MR approach. Finally, BERT is also tested on experimental data, obtaining an increase of the

  1. 10 CFR 35.490 - Training for use of manual brachytherapy sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Training for use of manual brachytherapy sources. 35.490 Section 35.490 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.490 Training for use of manual brachytherapy sources. Except as provided in § 35.57, the...

  2. 10 CFR 35.2432 - Records of calibration measurements of brachytherapy sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of calibration measurements of brachytherapy... Records § 35.2432 Records of calibration measurements of brachytherapy sources. (a) A licensee shall maintain a record of the calibrations of brachytherapy sources required by § 35.432 for 3 years after...

  3. Seed Treatment. Bulletin 760.

    Science.gov (United States)

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  4. Treatment technique evolution and dosimetry trends over seven years of prostate brachytherapy at the Royal Adelaide Hospital

    International Nuclear Information System (INIS)

    Full text: Prostate brachytherapy treatments began at the RAH in September of 2004 with over 280 patients treated to date with a cure rate of approximately 96%. This presentation will focus on the evolution of treatment technique since 2004 showing how significant time savings have been achieved for staff and patients, and how procedural improvements have enabled timely diagnosis of underdose and scheduling of top-up treatments for sub-optimum implants. In addition, dosimetry trends over this period will be presented. Methods Low dose rate brachytherapy employs Iodine-125 seeds which are permanently implanted into the prostate to deliver a target dose of 145 Gy. Treatments are planned on 3D trans-rectal ultrasound images using Nucletron SPOT PRO treatment planning system. Oncura Rapid Strand seeds are implanted with Rx preloaded needles that are deployed with ultra-sound guidance. The switch from manual loading of seeds to preloaded needles and the change from a two-step preplanning procedure to live planning have realized the greatest time savings with I FTE physics day and I patient day saved per treatment. Dosimetric parameters have also improved with implant D90s rising from 166 to 180 Gy. This reflects staff learning and also improvements in technique. With larger doses delivered to the target there is a trend to increase the urethra dose, with urethra D I Os rising from approximately 172-202 Gy. This result remains below the GEC-ESTRO limit, as is the mean rectum dose (02 cc of 79 Gy). Patient top-up treatments have recorded large 090 improvements, with a mean increase of 68%.

  5. Dosimetric and technical aspects of intraoperative I-125 brachytherapy for stage I non-small cell lung cancer

    International Nuclear Information System (INIS)

    Initial treatment outcome data from our institution for stage I non-small cell lung cancer (NSCLC) patients have shown that sublobar resection in combination with iodine-125 (I-125) brachytherapy is associated with recurrence rates of 2.0%, compared to 18.6% with sublobar resection alone. In this work, the technical and dosimetric aspects required to execute this procedure from the radiation oncology perspective as well as an analysis of the dose distributions of patients treated with this technique are presented. In this treatment technique, I-125 seeds in vicryl suture are embedded into vicryl mesh and surgically inserted providing a 2.0 cm margin on each side of the resection staple line. A nomogram is developed to determine the suture spacing in the vicryl mesh, as a function of seed activity in order to deliver 120 Gy at a distance of 0.5 cm above and below the seed array. Post-operative dosimetry consists of a CT-based planning and dose volume analysis. Dose distributions, dose volume histograms and mean dose data for lung are analysed in a group of patients. Dosimetric results show significant lung sparing with only a small volume of lung irradiated for all patients with mean lung dose values ranging from 1.5 Gy to 5.4 Gy. Lung brachytherapy with I-125 at the time of sublobar resection is a highly conformal option of dose delivery for stage I NSCLC patients with compromised physiologic reserve. Patient-related toxicity clinically measured by loss of pulmonary function and radiation-induced pneumonitis have not been linked to this procedure

  6. Dosimetric and technical aspects of intraoperative I-125 brachytherapy for stage I non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Mark [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Colonias, Athanasios [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Parda, David [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Trombetta, Mark [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Gayou, Olivier [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Reitz, Bodo [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Miften, Moyed [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States)

    2007-03-07

    Initial treatment outcome data from our institution for stage I non-small cell lung cancer (NSCLC) patients have shown that sublobar resection in combination with iodine-125 (I-125) brachytherapy is associated with recurrence rates of 2.0%, compared to 18.6% with sublobar resection alone. In this work, the technical and dosimetric aspects required to execute this procedure from the radiation oncology perspective as well as an analysis of the dose distributions of patients treated with this technique are presented. In this treatment technique, I-125 seeds in vicryl suture are embedded into vicryl mesh and surgically inserted providing a 2.0 cm margin on each side of the resection staple line. A nomogram is developed to determine the suture spacing in the vicryl mesh, as a function of seed activity in order to deliver 120 Gy at a distance of 0.5 cm above and below the seed array. Post-operative dosimetry consists of a CT-based planning and dose volume analysis. Dose distributions, dose volume histograms and mean dose data for lung are analysed in a group of patients. Dosimetric results show significant lung sparing with only a small volume of lung irradiated for all patients with mean lung dose values ranging from 1.5 Gy to 5.4 Gy. Lung brachytherapy with I-125 at the time of sublobar resection is a highly conformal option of dose delivery for stage I NSCLC patients with compromised physiologic reserve. Patient-related toxicity clinically measured by loss of pulmonary function and radiation-induced pneumonitis have not been linked to this procedure.

  7. Climate Reconstructions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Paleoclimatology Program archives reconstructions of past climatic conditions derived from paleoclimate proxies, in addition to the Program's large...

  8. Laryngopharyngeal reconstruction

    OpenAIRE

    Kazi, Rehan A

    2006-01-01

    There is a high incidence of hypopharyngeal cancer is our country due to the habits of tobacco and alcohol. Moreover these cases are often detected in the late stages thereby making the issue of reconstruction very tedious and unpredictable. There are a number of options for laryngopharyngeal reconstruction available now including the use of microvascular flaps depending upon the patient’s fitness, motivation, technical expertise, size and extent of the defect. This article reviews the differ...

  9. Utilization and Outcomes of Breast Brachytherapy in Younger Women

    International Nuclear Information System (INIS)

    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. 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