I-125 seed dose estimates in heterogeneous phantom

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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)

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

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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.

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

Science.gov (United States)

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

2014-12-01

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

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)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

Pirchio, R.; Saravi, M.; Banchik, D.; Munoz, C.

2006-01-01

A new source of 125 I model Braquibac TM 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, S K , was calculated as 1,036 c Gy cm 2 h -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)

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

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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

The Effect of Scattering from Leg Region on Organ Doses in Prostate Brachytherapy for 103Pd, 125I and 131Cs Seeds

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Seyed Milad Vahabi

2016-09-01

Full Text Available Introduction Dose calculation of tumor and surrounding tissues is essential during prostate brachytherapy. Three radioisotopes, namely, 125I, 103Pd, and 131Cs, are extensively used in this method. In this study, we aimed to calculate the received doses by the prostate and critical organs using the aforementioned radioactive seeds and to investigate the effect of scattering contribution for the legs on dose calculations. Materials and Methods The doses to organs of interest were calculated using MCNPX code and ORNL (Oak Ridge National Laboratory phantom. Results Doses to the prostate as a source of radiation for 125I, 103Pd, and 131Cs were approximately 108.9, 97.7, and 81.5 Gy, respectively. Bladder, sigmoid colon, and testes received higher doses than other organs due to proximity to the prostate. Differences between the doses when tallying with the legs intact and with the legs voided were significant for testes, sigmoid colon contents, and sigmoid colon wall because of their proximity to the prostate. There was also a good consistency between our results and the data published by Montefiore Medical Center and Albert Einstein College of Medicine for the prostate. Conclusion Scattering from leg region had a significant effect on doses to testes, sigmoid colon contents, and sigmoid colon wall in the pelvic region, and prostate and the other organs were unaffected. Brachytherapy treatment plans using 131Cs seeds allow for better sparing of critical tissues, with a comparable number of, or fewer, seeds required, compared to 125I seeds.

Postenucleation orbits in retinoblastoma: treatment with 125I brachytherapy

International Nuclear Information System (INIS)

Stannard, Clare; Sealy, Ross; Hering, Egbert; Hough, Jan; Knowles, Ruth; Lecuona, Karin; Reddi, V. Bala

2002-01-01

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. 125 I 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 125 I 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 125 I 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

Occupational exposure in prostate permanent implants with I-125 seeds

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Fdez Garcia, J.; Luna, V.; Sancho, J. M. g.; Martinez, J.; Galiano, P. S.; Jimenez, I.; Prada, P.; Juan, G.; Vivanco, J.

2002-07-01

Prostate brachytherapy is one of the techniques increasing faster in the environment of the radiotherapy and will probably go on increasing in the future. There are two forms in their use; by means of remote afterloading high dose rate (HDR) with Ir-192 radioactive sources or by means of permanent implant by manual/automatic afterloading of low dose rate (LDR) with seeds of I-125 or Pd-103. Iodine-125 has a half life of 59.4 days and it decays by electron capture with emissions of characteristic photons and electrons. The electrons are absorbed by the titanium wall of the I-125 seed. The principal photon emissions are 27.4 and 31.4 keV X-rays and a 35.5 keV gamma ray. Besides 22.1 and 25.2 keV fluorescent X-rays are also emitted resulting from interactions of the iodine-125 photons with the silver rod. The resulting average photon energy is approximately 27.4 keV. (Author)

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

International Nuclear Information System (INIS)

Issa, Fatma; Hugtenburg, Richard P.; Nisbet, Andrew; Bradley, David A.

2013-01-01

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 125 I 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 125 I 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 125 I source of 1 mm to 60 mm. • The TL of optical fibres accommodate high dose gradients and doses that reduce by a factor of 10 3 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

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

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Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin--Madison, Madison, Wisconsin 53705 (United States); Global Physics Solutions, St. Joseph, Michigan 49085 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

2009-01-15

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

COMS eye plaque brachytherapy dosimetry simulations for 103Pd, 125I, and 131Cs

International Nuclear Information System (INIS)

Melhus, Christopher S.; Rivard, Mark J.

2008-01-01

Monte Carlo (MC) simulations were performed to estimate brachytherapy dose distributions for Collaborative Ocular Melanoma Study (COMS) eye plaques. Brachytherapy seed models 200, 6711, and CS-1 Rev2 carrying 103 Pd, 125 I, and 131 Cs radionuclides, respectively, were modeled and benchmarked against previously published values. Calculated dose rate constants MC Λ were 0.684, 0.924, and 1.052 cGy h -1 U -1 (±2.6%, k=1 uncertainty) for models 200, 6711, and CS-1 Rev2, respectively. The seeds were distributed into 10, 12, 14, 16, 18, 20, and 22 mm-diameter COMS eye plaques. Simulations were performed in both heterogeneous and homogeneous environments, where the latter were in-water and the former included the silastic seed carrier insert and gold-alloy plaque. MC-based homogenous central axis dose distributions agreed within 2%±1% (±1 s.d.) to hand-calculated values. For heterogeneous simulations, notable photon attenuation was observed, with dose reduction at 5 mm of 19%, 11%, and 9% for 103 Pd, 125 I, and 131 Cs, respectively. A depth-dependent correction factor was derived to correct homogenous central-axis dose distributions for plaque component heterogeneities, which were found to be significant at short radial distances

Adjuvant iodine-125 brachytherapy for hepatocellular carcinoma after complete hepatectomy: a randomized controlled trial.

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Kaiyun Chen

Full Text Available BACKGROUND: Tumor recurrence is a major problem after curative resection of hepatocellular carcinoma (HCC. The current study evaluated the effects of adjuvant iodine-125 ((125I brachytherapy on postoperative recurrence of HCC. METHODOLOGY/PRINCIPAL FINDINGS: From July 2000 to June 2004, 68 HCC patients undergoing curative hepatectomy were randomly assigned into a (125I adjuvant brachytherapy group (n = 34 and a group of best care (n = 34. Patients in the (125I adjuvant brachytherapy group received (125I seed implantation on the raw surface of resection. Patients in the best care control group received identical treatments except for the (125I seed implantation. Time to recurrence (TTR and 1-, 3- and 5-year overall survival (OS were compared between the two groups. The follow-up ended in January 2010, and lasted for 7.7-106.4 months with a median of 47.6 months. TTR was significantly longer in the (125I group (mean of 60.0 months vs. 36.7 months in the control. The 1-, 3- and 5-year recurrence-free rates of the (125I group were 94.12%, 76.42%, and 73.65% vs. 88.24%, 50.00%, and 29.41% compared with the control group, respectively. The 1-, 3- and 5-year OS rates of the (125I group were 94.12%, 73.53%, and 55.88% vs. 88.24%, 52.94%, and 29.41% compared with the control group, respectively. The (125I brachytherapy decreased the risk of recurrence (HR = 0.310 and the risk of death (HR = 0.364. Most frequent adverse events in the (125I group included nausea, vomiting, arrhythmia, decreased white blood cell and/or platelet counts, and were generally mild and manageable. CONCLUSIONS/SIGNIFICANCE: Adjuvant (125I brachytherapy significantly prolonged TTR and increased the OS rate after curative resection of HCC. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12610000081011.

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

International Nuclear Information System (INIS)

Leal, Alexandre S.; Viana, Gustavo A.

2015-01-01

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 124 Xe atoms of the samples are converted into 125 Xe, according to the reaction: 124 Xe (n,γ) 125 Xe that, in turn, decays to the radioisotope 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)

Monte Carlo dosimetry for 125I and 103Pd eye plaque brachytherapy

International Nuclear Information System (INIS)

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

2008-01-01

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

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

International Nuclear Information System (INIS)

Wang Zhongmin; Lu Jian; Gong Ju; Zheng Yunfeng; Zhang Liyun; Huang Gang; Chen Kemin

2009-01-01

Objective: To discuss the clinical efficacy of CT-guided radioactive 125 I 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 125 I seeds. The radioactivity of 125 I 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 125 I 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 125 I 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)

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

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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.

Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources: an EGS4 Monte Carlo study

International Nuclear Information System (INIS)

Mainegra, Ernesto; Capote, Roberto; Lopez, Ernesto

1998-01-01

An exhaustive revision of dosimetry data for 192 Ir, 125 I, 103 Pd and 169 Yb brachytherapy sources has been performed by means of the EGS4 simulation system. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. The absorbed dose rate per unit contained activity in a medium at 1 cm in water and air-kerma strength per unit contained activity for each seed model were calculated, allowing the dose rate constant (DRC) Λ to be estimated. The influence of the calibration procedure on source strength for low-energy brachytherapy seeds is discussed. Conversion factors for 125 I and 103 Pd seeds to obtain the dose rate in liquid water from the dose rate measured in a solid water phantom with a detector calibrated for dose to water were calculated. A theoretical estimate of the DRC for a 103 Pd model 200 seed equal to 0.669±0.002 cGy h -1 U -1 is obtained. Comparison of obtained DRCs with measured and calculated published results shows agreement within 1.5% for 192 Ir, 169 Yb and 125 I sources. (author)

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

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Samia de Freitas Brandao

2013-07-01

Full Text Available Objective Comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and Methods Simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results Intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the I 1 and I 2 tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the I 1 and I 2 infiltration zones. Conclusion Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones.

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)

Song Qi; Liu Yu; Wang Zhongmin; Huang Wei; Lu Jian; Chen Kemin

2010-01-01

Objective: To discuss the effectiveness and therapeutic mechanism of 125 I 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 125 I 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

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

International Nuclear Information System (INIS)

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

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 125 I 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 125 I seeds, treated in our hospital, for a patient with ocular lesions. 125 I seeds were calibrated using well-type chamber. BrachyVision TPS was configured with Monte Carlo computed radial dose functions and anisotropy functions for 125 I sources. Dose calculated by TPS at different points in central axis and off axis was compared with manually calculated dose. Eye plaque was fabricated of 17 karat pure gold, locally. The seeds were arranged in an outer ring near the edge of the plaque and in concentric rings throughout the plaque. The sources were manually digitized on the TPS, and dose distribution was calculated in three dimensions. Measured activity using cross-calibrated well-type chamber was within ± 10% of the activity specified by the supplier. Difference in TPS-calculated dose and manually calculated dose was within 5%. Treatment time calculated by TPS was in concordance with published data for similar plaque arrangement. (author)

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

International Nuclear Information System (INIS)

Li Dandan; Liu Lin; Gao Shi; Qi Liangchen; Ma Qingjie; Jin Longyun

2010-01-01

To search for certain signature proteins and the expression profiles in lacrimal passage stenosis, rabbit models of lacrimal passage stenosis were treated by 125 I 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)

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

International Nuclear Information System (INIS)

Fan, Yi; Huang, Ming-Wei; Zheng, Lei; Zhao, Yi-Jiao; Zhang, Jian-Guo

2015-01-01

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 125 I 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. 125 I 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

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

Energy Technology Data Exchange (ETDEWEB)

Brandao, Samia de Freitas, E-mail: samiabrandao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

2013-06-15

Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively, on the healthy tissue, on the balloon periphery and on the /{sub 1} and /{sub 2} tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively on the healthy tissue, on the target tumor and on the /{sub 1} and /{sub 2} infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

Dosimetric study in iodine-125 seeds for brachytherapy application

International Nuclear Information System (INIS)

Zeituni, Carlos Alberto

2008-01-01

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)

Permanent Seed Implant Dosimetry (PSID)TM 4.5 version as isodose and Treatment Planning System (TPS) programme for brachytherapy

International Nuclear Information System (INIS)

Indra Saptiama; Moch Subechi; Anung Pujiyanto; Hotman Lubis; Herlan Setiawan

2014-01-01

The medical treatment using radiation therapy for cancer diseases is increasingly developed. One of the method used in radiotherapy is brachytherapy. Brachytherapy is radiation therapy method in which a radiation source is implanted in cancer cell directly so the dose accepted by cancer cell is the highest dose and the dose accepted by normal cell is the lowest dose. I-125 Seed have been made successfully in domestic. To support the implant of I-125 seed for brachytherapy needs computer programme for the isodose calculation and Treatment Planning System (TPS). Permanent Seed Implant Dosimetry (PSID) 4.5 is one of the isodose calculation and Treatment Planning System (TPS) programme that is owned by Center for Radioisotope and Radiopharmaceutical-BATAN. In isodose calculation, PSID 4.5 uses 1D formalism and 2D formalism based on AAPM-TG43 (Association of American Physicist in Medicine- Task Group No.43). Anisotropic function on 1D formalism depend on distance function while on 2D formalism count on distance and angle function therefore 2D formalism has isodose calculation better than 1D formalism usage. PSID 4.5 can display the isodose contour of the seed I-125 radiation source in 2 dimension (2D) and 3 dimension (3D). The computer programme of isodose calculation and TPS uses PSID 4.5 is expected able to help planning for seed I-125 implantation process for brachytherapy that used by paramedics and to support the usage of seed I-125 as domestic product. (author)

More accurate fitting of 125I and 103Pd radial dose functions

International Nuclear Information System (INIS)

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

2008-01-01

In this study an improved functional form for fitting the radial dose functions, g(r), of 125 I and 103 Pd brachytherapy seeds is presented. The new function is capable of accurately fitting radial dose functions over ranges as large as 0.05 cm≤r≤10 cm for 125 I seeds and 0.10 cm≤r≤10 cm for 103 Pd seeds. The average discrepancies between fit and calculated data are less than 0.5% over the full range of fit and maximum discrepancies are 2% or less. The fitting function is also capable of accounting for the sharp increase in g(r) (upturn) seen for some sources for r 125 I seeds and 9 103 Pd seeds using the EGSnrc Monte Carlo user-code BrachyDose. Fitting coefficients of the new function are tabulated for all 27 seeds. Extrapolation characteristics of the function are also investigated. The new functional form is an improvement over currently used fitting functions with its main strength being the ability to accurately fit the rapidly varying radial dose function at small distances. The new function is an excellent candidate for fitting the radial dose function of all 103 Pd and 125 I brachytherapy seeds and will increase the accuracy of dose distributions calculated around brachytherapy seeds using the TG-43 protocol over a wider range of data. More accurate values of g(r) for r<0.5 cm may be particularly important in the treatment of ocular melanoma

Iodine 125 seed migration after prostate brachytherapy: a study of 170 patients

International Nuclear Information System (INIS)

Chauveinc, L.; Osseili, A.; Rosenwald, J.C.; Cosset, J.M.; Flam, T.; Thiounn, N.; Savignoni, A.

2004-01-01

Purpose. To study the number of migrating seeds, the anatomical site of migration and possible predictive parameters of migration, after prostate cancer brachytherapy using a loose-seed (I125) implantation technique. Patients and methods. The charts of the 170 patients consecutively treated by the Institut Curie/Hospital Cochin/Hospital Necker Group between September 1, 2001 and August 31, 2002, were analysed. All seeds having migrated to the lungs and seen on the chest X-ray systematically performed at 2 months, have been recorded, as well as the seeds lost by the urines (after sieving) or in the sperm (condom). Results. Among 12,179 implanted seeds, 44 were found to have migrated (0.36%). Most of the migrating seeds (32/44; 73%), were found in the lungs. Overall, one or several seed migrations were observed in 35 patients (21% of the total number of patients in this series). In the majority of cases (77< r i. only one seed migrated. A significant relationship (P = 0.04) vs as found between the number of migrating seeds and the number of implanted ones (or with the prostate volume, but those two parameters were closely linked in our series). More specifically, a significant relationship (P = 0.02) could be demonstrated between the number of seeds implanted at the periphery of the prostate and the number of seeds migrating to the lungs. Conclusion. The percentage of migrating seeds observed in this series is low. actually one of the lowest found in the literature when using the loose-seed technique. There was no clinical consequences and the loss of-usually only one seed is very unlikely to alter the quality of the dose distribution. However, the predominance of pulmonary migrations in our series led us to slightly modify our implantation technique. We now try to avoid too 'peripheral' seed implantations, due to the risk of migration towards the peri-prostatic veins, and subsequently to the lungs. (author)

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

International Nuclear Information System (INIS)

Chen, Allen M.; Chang, Susan; Pouliot, Jean; Sneed, Penny K.; Prados, Michael D.; Lamborn, Kathleen R.; Malec, Mary K.; McDermott, Michael W.; Berger, Mitchell S.; Larson, David A.

2007-01-01

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 cm 3 (range, 4.4-41.2 cm 3 ). 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

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

International Nuclear Information System (INIS)

Somessari, Samir L.; Feher, Anselmo; Sprenger, Francisco E.; Rostellato, Maria Elisa C.M.; Costa, Fabio E.; Calvo, Wilson A.P.

2009-01-01

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)

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

International Nuclear Information System (INIS)

Somessari, Samir Luiz

2010-01-01

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)

High-resolution 3D dose distribution measured for two low-energy x-ray brachytherapy seeds: 125I and 103Pd

International Nuclear Information System (INIS)

Massillon-JL, G.; Minniti, R.; Mitch, M.G.; Soares, C.G.; Hearn, R.A.

2011-01-01

In this work, we have investigated the 3D absorbed dose distribution around 125 I and 103 Pd low-energy photon brachytherapy seeds using a high-spatial-resolution gel scanning system to address the current difficulty in measuring absorbed dose at close distances to these sources as a consequence of high dose rate gradient. A new version of BANG-gel coupled with a small format laser CT scanner has been used. Measurements were performed with 100 μm resolution in all dimensions. In particular, radial dose function and absorbed dose rate in the plane parallel to the sources longitudinal-axis were derived at radial distances smaller than or equal to 1 cm. In addition, the energy dependence was evaluated, finding that, within measurement uncertainties, the gel response is independent of the energy for energy photon values between 20 keV and 1250 keV. We have observed that at distances larger than 1.4 mm from the source, the delivered dose is similar to predictions from published Monte Carlo calculations (MC) for the 125 I seed. For distances between 1 mm and 3 mm, differences in magnitude and shape are significant for the 103 Pd seed, where an enhancement is observed. In the enhancement region, a difference of up to 70% in the radial dose function was obtained. Such observation suggests a contribution from other radionuclides emitting beta-particles or electrons, and not considered by MC. To understand the effect, spectrometry measurements were performed. A small contribution of 102 Rh/ 102m Rh radionuclide relative to 103 Pd was observed and its importance on the absorbed dose measured at close distances to the seed is time dependent and consequently, avoids reproducible measurements. Finally, the results obtained in this work underscore the importance of using high-spatial-resolution and water-equivalent detectors for measuring absorbed dose in low-energy photon radiation fields.

Permanent interstitial implantation of 125Iodine seed for thoracic malignant tumors

International Nuclear Information System (INIS)

Xu Zhongheng; Qian Yongyue; Wu Jinchang; Liu Zengli

2002-01-01

Objective: To observe effect of 125 Iodine sed on interstitial brachytherapy of patient with thoracic malignant tumor. Methods: 125 Iodine seed were inserted into the target tissue and permanent left there for brachytherapy in 6 cases of thoracic malignant tumors, which including lung cancer, Pancoast's tumour, mediastinal malignant schwannoma. Results: All cases were rehabilitated shortly after operation. The implanted lesions remained controlled now and in dead patients. No radiation-related and 125 Iodine seed-related complications occurred. Conclusion: Brachytherapy by implantation of 125 Iodine seeds of remained tumor tissue in patients with thoracic malignant tumor after operation has a satisfactory outcome. This therapy can control local recurrent of thoracic malignant tumor. But the results in long term should be studied further

Brazilian demand for Iodine-125 seeds in cancer treatment after a decade of medical procedures

Energy Technology Data Exchange (ETDEWEB)

Costa, Osvaldo L. da; Souza, Daiane C.B. de; Feher, Anselmo; Moura, João A.; Souza, Carla D.; Oliveira, Henrique B. de; Peleiras Junior, Fernando S.; Zeituni, CArlos A.; Rostelaro, Maria E.C.M., E-mail: olcosta@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-07-01

Iodine-125 and palladium-103 are radionuclides employed to made medical devices used in cancer treatment known as brachytherapy seeds. These radioactive sealed sources are applied in brain and ophthalmic cancer as a temporary implant to irradiate the tumor and in permanent implants to prostatic cancer. Brazilian Nuclear Energy Commission (CNEN) has the monopoly in Brazil of iodine-125 brachytherapy seeds distribution which is executed for Nuclear and Energy Research Institute (IPEN-CNEN/SP). Along a decade of use in Brazil more than 240 thousand seeds were implanted in patients or used to treat cancer tumors. In this article the Brazilian demand for iodine-125 brachytherapy seeds is analyzed. The demand behavior along a decade of using loose, strand, ophthalmic and brain brachytherapy seeds are shown. The annual quantity of seeds demanded by Brazil has dropped since 2012. The loose seeds which represented until 30% from total brachytherapy seeds used in Brazil decreased to less than 3%. The brain brachytherapy seeds had low demand along the decade and presented zero demand in several years. Concurrent treatment techniques are listed and main trends are discussed. The influence of Brazilian economic crisis and the demand behavior of the main hospitals and clinics that use Iodine-125 brachytherapy are shown. (author)

Brazilian demand for Iodine-125 seeds in cancer treatment after a decade of medical procedures

International Nuclear Information System (INIS)

Costa, Osvaldo L. da; Souza, Daiane C.B. de; Feher, Anselmo; Moura, João A.; Souza, Carla D.; Oliveira, Henrique B. de; Peleiras Junior, Fernando S.; Zeituni, CArlos A.; Rostelaro, Maria E.C.M.

2017-01-01

Iodine-125 and palladium-103 are radionuclides employed to made medical devices used in cancer treatment known as brachytherapy seeds. These radioactive sealed sources are applied in brain and ophthalmic cancer as a temporary implant to irradiate the tumor and in permanent implants to prostatic cancer. Brazilian Nuclear Energy Commission (CNEN) has the monopoly in Brazil of iodine-125 brachytherapy seeds distribution which is executed for Nuclear and Energy Research Institute (IPEN-CNEN/SP). Along a decade of use in Brazil more than 240 thousand seeds were implanted in patients or used to treat cancer tumors. In this article the Brazilian demand for iodine-125 brachytherapy seeds is analyzed. The demand behavior along a decade of using loose, strand, ophthalmic and brain brachytherapy seeds are shown. The annual quantity of seeds demanded by Brazil has dropped since 2012. The loose seeds which represented until 30% from total brachytherapy seeds used in Brazil decreased to less than 3%. The brain brachytherapy seeds had low demand along the decade and presented zero demand in several years. Concurrent treatment techniques are listed and main trends are discussed. The influence of Brazilian economic crisis and the demand behavior of the main hospitals and clinics that use Iodine-125 brachytherapy are shown. (author)

Radiation protective nursing intervene of 125I seed implantation in non-small cell lung carcinoma guided by CT

International Nuclear Information System (INIS)

Fu Li; Zhang Zuncheng; Yu Zhaochen; Zheng Guangjun; Tian Meirong

2009-01-01

Objective: To research radiation protective nursing intervene and important notice of 125 I seeds minimally invasive implantation in non-small cell lung carcinoma (NSCLC) by CT. Methods: Under the system of therapy planning system (TPS) and posologic validation, 125 I seeds were implanted in 89 cases of NSCLC patients. The consistent radiation protective nursing intervene was used in perioperative period management. The operative successful rate, therapeutic effect and complication rate, therapeutic effect and complication rate was observed. Results: The scientific radiation protective nursing intervene can ensure that the radioactive dose distribution of 125 I seed implantation brachytherapy is consistent with the principles of effective and minimally invasive. The operative successful rate was 100%. The local control rate and 1 year survival rate respectively was 97.4% and 92.2%. But the early and later incidence rate of radioactive damaging effect was 14.6% and 1.1% respectively. Leakage of radioactive contamination has not occurred. Conclusion: The consistent TPS and posologic validation 125 I seeds implantation integrated scientific radiation protective nursing intervene. It is very important to improve the therapeutic effect of NSCLC and reduce the incidence of complications. (authors)

Dosimetric studies, spectrometric, radiographic, metallographic of a new argentinean seed of {sup 125} I used in brachytherapy; Estudios dosimetricos, espectrometricos, radiograficos, metalograficos de una nueva semilla argentina de {sup 125}I empleada en braquiterapia

Energy Technology Data Exchange (ETDEWEB)

Pirchio, R.; Saravi, M.; Banchik, D.; Munoz, C. [CNEA, Pbro. J. Gonzalez y Aragon No. 15 (B1802AYA), Ezeiza, Buenos Aires (Argentina)]. e-mail: pirchio@cae.cnea.gov.ar

2006-07-01

A new source of {sup 125} I model Braquibac{sup TM} 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, {lambda}, of the function of anisotropy of two dimensions, F(r, {theta}), 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{sup -1} U{sup -1}. The kerma in air rate of reference, S{sub K}, was calculated as 1,036 c Gy cm{sup 2}h{sup -1} mCi{sup -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 {sup 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)

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

International Nuclear Information System (INIS)

Somessari, S.L.; Feher, A.; Sprenger, F.E.; Rostelato, M.E.C.M.; Costa, F.E. da; Calvo, W.A.P.

2011-01-01

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 0.8 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)

Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code

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Leonardo da Silva Boia

2014-03-01

decline for short distances.------------------------------Cite this article as: Boia LS, Junior J, Menezes AF, Silva AX. Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code. Int J Cancer Ther Oncol 2014; 2(2:02023.DOI: http://dx.doi.org/10.14319/ijcto.0202.3

Feasibility and clinical value of CT-guided {sup 125}I brachytherapy for metastatic soft tissue sarcoma after first-line chemotherapy failure

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Mo, Zhiqiang; Zhang, Yanling; Xiang, Zhanwang; Yan, Huzhen; Zhong, Zhihui; Gao, Fei; Zhang, Fujun [Sun Yat-Sen University Cancer Centre, State Key Laboratory of Oncology in South China, Collaborative Innovation Centre for Cancer Medicine, Guangzhou (China); Zhang, Tao [Guangzhou Medical University, Department of Interventional Radiology and Vascular Anomalies, Guangzhou Women and Children' s Medical Centre, Guangzhou (China)

2018-03-15

To evaluate the feasibility and usefulness of computed tomography (CT)-guided iodine{sup 125} ({sup 125}I) brachytherapy for patients with metastatic soft tissue sarcoma (STS) after first-line chemotherapy failure. We recruited 93 patients with metastatic STS who had received first-line chemotherapy 4-6 times but developed progressive disease, from January 2010 to July 2015; 45 patients who had combined {sup 125}I brachytherapy and second-line chemotherapy (Group A), and 48 patients who received second-line CT only (Group B). In Group A, 49 {sup 125}I seed implantation procedures were performed in 45 patients with 116 metastatic lesions; the primary success rate was 91.1% (41/45), without life-threatening complications. Local control rates at 3, 6, 12, 24 and 36 months were 71.1%, 62.2%, 46.7%, 28.9% and 11.1% for Group A, and 72.9%, 54.2%, 18.8%, 6.3% and 0% for Group B. Mean progression-free survival differed significantly (Group A: 7.1±1.3 months; Group B: 3.6 ±1.1 months; P<0.001; Cox proportional hazards regression analysis), but overall survival did not significantly differ (Group A: 16.9 ±5.1 months; Group B: 12.1 ± 4.8 months). Group A showed better symptom relief and quality of life than Group B. CT-guided {sup 125}I brachytherapy is a feasible and valuable treatment for patients with metastatic STS. (orig.)

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

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Moorrees Joshua

2012-11-01

Full Text Available Abstract Background 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. Methods 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. Results 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. Conclusions 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

Health-Related Quality of Life up to Six Years After 125I Brachytherapy for Early-Stage Prostate Cancer

International Nuclear Information System (INIS)

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

2010-01-01

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

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

International Nuclear Information System (INIS)

Mourao, Arnaldo P.; Campos, Tarcisio P.R.

2010-01-01

Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for departuring absorbed doses in tumor minimizing doses in the lens and the adjacent tissues of the eyeball (orbital region), avoiding deleterious effects. Thus, a three-dimensional computational 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)

Spectral CT with monochromatic imaging and metal artifacts reduction software for artifacts reduction of ¹²⁵I radioactive seeds in liver brachytherapy.

Science.gov (United States)

Yang, Qiuxia; Peng, Sheng; Wu, Jing; Ban, Xiaohua; He, Mingyan; Xie, Chuanmiao; Zhang, Rong

2015-11-01

To investigate the optimal monochromatic energy for artifacts reduction from (125)I seeds as well as image improvement in the vicinity of seeds on monochromatic images with and without metal artifacts reduction software (MARS) and to compare this with traditional 120-kVp images, so as to evaluate the application value of gemstone spectral imaging for reducing artifacts from (125)I seeds in liver brachytherapy. A total of 45 tumors from 25 patients treated with (125)I seed brachytherapy in the liver were enrolled in this study. Multiphasic spectral computed tomography (CT) scanning was performed for each patient. After a delay time of 15 s of portal vein phase, a traditional 120-kVp scan was performed, focusing on several planes of (125)I seeds only. The artifact index (AI) in the vicinity of seeds and the standard deviation (SD) of the CT density of region of interest in the outside liver parenchyma were calculated. Artifact appearance was evaluated and classified on reconstructed monochromatic S and 120-kVp images. Image quality in the vicinity of seeds of three data sets were evaluated using a 1-5 scale scoring method. The Friedman rank-sum test was used to estimate the scoring results of image quality. The greatest noise in monochromatic images was found at 40 keV (SD = 27.38, AI = 206.40). The optimal monochromatic energy was found at 75 keV, which provided almost the least image noise (SD = 10.01) and good performance in artifact reduction (AI = 102.73). Image noise and AI reduction at 75 keV was decreased by 63.44 and 50.23%, compared with at 40 keV. Near-field thick artifacts were obvious in all 45 lesions, in 120-kVp images, and 75-keV images, but basically reduced in 75 keV MARS images and artifacts completely invisible in 7 lesions. The number of diagnosable images (score ≥3) was significantly more in the 75-keV MARS group (28/45), and the 75-keV group (22/45) than in the 120-kVp group (11/45) (p improve image quality, even to a state of being

Long-Term Results of Brachytherapy With Temporary Iodine-125 Seeds in Children With Low-Grade Gliomas

International Nuclear Information System (INIS)

Korinthenberg, Rudolf; Neuburger, Daniela; Trippel, Michael; Ostertag, Christoph; Nikkhah, Guido

2011-01-01

Purpose: To retrospectively review the results of temporary I-125 brachytherapy in 94 children and adolescents with low-grade glioma. Methods and Materials: Treatment was performed in progressive tumors roughly spherical in shape with a diameter of up to 5 cm, including 79 astrocytomas, 5 oligodendrogliomas, 4 oligoastrocytomas, 1 ependymoma, and 5 other tumors. Location was suprasellar/chiasmal in 44, thalamic/basal ganglia in 18, hemispheric in 15, midbrain/pineal region in 13, and lower brainstem in 3. Initially, 8% of patients were free of symptoms, 47% were symptomatic but not disabled, and 30% were slightly, 6% moderately, and 3% severely disabled. Results: 5- and 10-year survival was 97% and 92%. The response to I-125 brachytherapy over the long term was estimated after a median observation period of 38.4 (range, 6.4-171.0) months. At that time, 4 patients were in complete, 27 in partial, and 18 in objective remission; 15 showed stable and 30 progressive tumors. Treatment results did not correlate with age, sex, histology, tumor size, location, or demarcation of the tumor. Secondary treatment became necessary in 36 patients, including 19 who underwent repeated I-125 brachytherapy. At final follow-up, the number of symptom-free patients had risen to 21%. Thirty-eight percent showed symptoms without functional impairment, 19% were slightly and 11% moderately disabled, and only 4% were severely disabled. Conclusions: Response rates similar to those of conventional radiotherapy or chemotherapy can be anticipated with I-125 brachytherapy in tumors of the appropriate size and shape. We believe it to be a useful contribution to the treatment of low-grade gliomas in children.

Prostate brachytherapy seed migration to the heart seen on cardiovascular computed tomographic angiography

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Shilpa Sachdeva, MD

2017-03-01

Full Text Available Brachytherapy consists of placing radioactive sources into or adjacent to tumors, to deliver conformal radiation treatment. The technique is used for treatment of primary malignancies and for salvage in recurrent disease. Permanent prostate brachytherapy seeds are small metal implants containing radioactive sources of I-125, Pd-103, or Cs-131 encased in a titanium shell. They can embolize through the venous system to the lungs or heart and subsequently be detected by cardiovascular computed tomography. Cardiovascular imagers should be aware of the appearance of migrated seeds, as their presence in the chest is generally benign, so that unnecessary worry and testing are avoided. We report a case of a patient who underwent brachytherapy for prostate cancer and developed a therapeutic seeds embolus to the right ventricle.

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

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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

Development of procedure using plasma welding process to produce 125I seeds

International Nuclear Information System (INIS)

Feher, Anselmo

2006-01-01

The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer, is a problem of public health in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing 125 I radioisotope are implanted in the prostate. 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 125 I. The plasma arc welding is one of the viable techniques for the sealing process. The equipment used in this technique is less costly than in other processes. The main objective of this work was the development and the validation of the welding procedure using plasma welding process and the elaboration of a sealing routine according to Good Manufacturing Practices. The development of this work has presented the following phases: cut and cleaning of the titanium material, determination of the welding parameters, development of a device for holding the titanium tube during the welding process, validation of sealed sources according to ISO 2919 Sealed Radioactive Sources - General Requirements and Classification, leakage test according to ISO 9978 Sealed Radioactive Sources - Leakage Test Methods and metallographic assays. The developed procedure, to seal 125 I seeds using plasma welding process, has shown to be efficient, satisfying all the established requirements of ISO 2919. The results obtained in this work have given the possibility to establish a routine production process according to the orientations presented in resolution RDC number 59 - Good Manufacturing Practices do Medical Products of the ANVISA - Brazilian Nacional Agency of Sanitary Surveillance. (author)

[Technique of intraoperative planning in prostatic brachytherapy with permanent implants of 125I or 103Pd].

Science.gov (United States)

Prada Gómez, Pedro José; Juan Rijo, Germán; Hevia Suarez, Miguel; Abascal García, José María; Abascal García, Ramón

2002-12-01

Prostatic brachytherapy with permanent 125I or 123Pd seeds implantation is a therapeutic option for organ-confined prostate cancer. We analyze the technique based on previous planning, our current intraoperative planning procedure and the reasons that moved us to introduce this change. Changes in prostate volume and spatial localization observed between previous planning and intraoperative images, and possible difficulties for seed implantation due to pubic arch interference are some of the reasons that induce us to change technique. Before the operation, we calculate the prostatic volume by transrectal ultrasound; with this information we determine the total implant activity following Wu's nomogram, and per-seed activity; therefore, it is an individual process for each patient. We perform a peripheral implant, placing 75-80% of the seeds within the peripheral prostatic zone, generally through 12-15 needles, the rest of the seeds are placed in the central prostatic zone using a maximum of 3-4 needles in high volume prostates. The day of intervention, after positioning and catheter insertion, volumetry is re-checked. Ultrasound images (from base to apex every 5 mm) are transferred to the planner were a suitable seed distribution is determined. Implantation is then performed placing all needles unloaded, and then intraoperative post-planning to allow us to check implant precision is performed after cistoscopically check that there is no urethral or bladder penetration by any needle. We finish with the insertion of seeds into the prostate. Total time for the procedure is around 90 minutes. Intraoperative planning is an additional step for the treatment of prostate cancer with permanent seeds brachytherapy, which avoids the disadvantages of previous planning and improves tumor inclusion in the ideal irradiation dose area, which will translate into better local disease control.

Implication for QOL after I-125 brachytherapy for prostate cancer

International Nuclear Information System (INIS)

Teishima, Jun; Yasumoto, Hiroaki; Inoue, Syogo; Masumoto, Hiroshi; Hasegawa, Yasuhisa; Matsubara, Akio

2009-01-01

The aim of this study is to evaluate the quality of life (QOL) of patients following prostate brachytherapy. Between July 2004 and May 2008, 139 patients underwent I-125 permanent brachytherapy. Among those patients, 69 who were followed up for more than one year using the Expanded Prostate Index Composite (EPIC), Japanese version v1 TM , were enrolled in this study. Urinary summary scores became worse temporarily at 1 month after the end of treatment, but then recovered gradually to the level before treatment. Sexual summary scores before treatment were 42.2±16.3. They became worse temporarily at 1 month after treatment but then recovered gradually in patients whose sexual summary scores were more than 40. Urinary morbidity scores after prostate brachytherapy were not so severe and recovered within a short period. Further long-term observation is thought to be required in the future. Sexual function scores of patients before treatment in the present study were lower compared with those recorded in previous studies. (author)

Iodine-125 seeds for cancer treatment

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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)

Exposure dose estimation of nursing personnel and visitors following "1"2"5I brachytherapy

International Nuclear Information System (INIS)

Nakazato, Kazuhisa; Kikuchi, Hirosumi; Hotta, Harumi; Nishizawa, Kunihide

2007-01-01

An automated access management system to the controlled sickrooms for "1"2"5I brachytherapy was developed. The system consists of access control and video surveillance units. The patients implanted "1"2"5I seeds were isolated for about 20 h after surgery in the controlled sickrooms. The maximum doses and dose rates of the nurses and visitors were estimated by using the legal upper limit activity of 1,300 MBq, the measured longest staying time, and the shortest distance between the patients and individuals. Video analysis revealed activities of the nurses, patients, and visitors in the controlled sickroom, and relationships between the access frequency and staying time. The nurses' measured doses ranged from 1 to 3 μSv, and averaged 1.6 μSv. The nurses' maximum dose and dose rate were 16 μSv and 5.6 nSv·h"-"1·MBq"-"1. The visitors' maximum dose and dose rate were 6 μSv and 2.6 nSv·h"-"1·MBq"-"1. The nurses and visitors' exposure doses per patient were estimated to be negligible compared with the annual limit of the public. (author)

Radiochromic film calibration for low-energy seed brachytherapy dose measurement

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Morrison, Hali, E-mail: hamorris@ualberta.ca; Menon, Geetha; Sloboda, Ron S. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

2014-07-15

Purpose: Radiochromic film dosimetry is typically performed for high energy photons and moderate doses characterizing external beam radiotherapy (XRT). The purpose of this study was to investigate the accuracy of previously established film calibration procedures used in XRT when applied to low-energy, seed-based brachytherapy at higher doses, and to determine necessary modifications to achieve similar accuracy in absolute dose measurements. Methods: Gafchromic EBT3 film was used to measure radiation doses upwards of 35 Gy from 75 kVp, 200 kVp, 6 MV, and (∼28 keV) I-125 photon sources. For the latter irradiations a custom phantom was built to hold a single I-125 seed. Film pieces were scanned with an Epson 10000XL flatbed scanner and the resulting 48-bit RGB TIFF images were analyzed using both FilmQA Pro software andMATLAB. Calibration curves relating dose and optical density via a rational functional form for all three color channels at each irradiation energy were determined with and without the inclusion of uncertainties in the measured optical densities and dose values. The accuracy of calibration curve variations obtained using piecewise fitting, a reduced film measurement area for I-125 irradiation, and a reduced number of dose levels was also investigated. The energy dependence of the film lot used was also analyzed by calculating normalized optical density values. Results: Slight differences were found in the resulting calibration curves for the various fitting methods used. The accuracy of the calibration curves was found to improve at low doses and worsen at high doses when including uncertainties in optical densities and doses, which may better represent the variability that could be seen in film optical density measurements. When exposing the films to doses > 8 Gy, two-segment piecewise fitting was found to be necessary to achieve similar accuracies in absolute dose measurements as when using smaller dose ranges. When reducing the film measurement

Ejaculatory Function After Permanent 125I Prostate Brachytherapy for Localized Prostate Cancer

International Nuclear Information System (INIS)

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

2009-01-01

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

Cooperation of Ad-hING4 and 125I seed in tumor-suppression on human pancreatic cancer xenograft in nude mice

International Nuclear Information System (INIS)

Zhai Hongyan; Fa Yihua; Su Chenghai; Yang Jicheng; Sheng Weihua; Xie Yufeng

2009-01-01

This work is to investigate the combined tumor-suppression effect of Adenovirus-mediated human ING4 (Ad-hING4) and 125 I seed on human pancreatic cancer xenograft and the possible mechanisms. Ad-hING4 recombinant adenovirus vector was transected into QBI-293A cells and high titre adenovirus was obtained. Subcutaneous tumor models were established with 25 nude mice with human pancreatic cancer cell line PANC-1. They were randomly divided into 5 groups: PBS control group, Ad carrier group, 125 I seed brachytherapy group, Ad-hING4 gene treatment group, combined 125 I seed and Ad-hING4 group. The tumor volumes were measured every 5 days after treatment, and were sacrificed on the 20th day. The tumors were measured and weighed to determine the ratio of tumor-suppression and Jin-Shi q value. Morphological changes of tumor cells,the tissue injury and apoptotic index AI were examined on pathological sections. MVD, Survivin and Caspase3 were tested in immunohistochemistry. The results show that the tumor-suppressive ratio of the 125 I seed group, Ad-hING4 group, combined treatment group were,respectively, 34.19%(P 0.05). It can be concluded that 125 I seed and Ad-hING4 inhibit the growth of PANC-1 pancreatic cancer on nude mice significantly. These indicate a synergy of the combined treatments in tumor-suppression and Ad-hING4 is a promising novel radiosensitizer. The mechanisms of tumor-suppressive may be multi-pathways such as down-regulation the expression of Survivin and up-regulation the expression of Caspase3 to induce apoptosis and inhibit angiogenesis. (authors)

Towards clinical application of RayStretch for heterogeneity corrections in LDR permanent 125I prostate brachytherapy.

Science.gov (United States)

Hueso-González, Fernando; Ballester, Facundo; Perez-Calatayud, Jose; Siebert, Frank-André; Vijande, Javier

RayStretch is a simple algorithm proposed for heterogeneity corrections in low-dose-rate brachytherapy. It is built on top of TG-43 consensus data, and it has been validated with Monte Carlo (MC) simulations. In this study, we take a real clinical prostate implant with 71 125 I seeds as reference and we apply RayStretch to analyze its performance in worst-case scenarios. To do so, we design two cases where large calcifications are located in the prostate lobules. RayStretch resilience under various calcification density values is also explored. Comparisons against MC calculations are performed. Dose-volume histogram-related parameters like prostate D 90 , rectum D 2cc , or urethra D 10 obtained with RayStretch agree within a few percent with the detailed MC results for all cases considered. The robustness and compatibility of RayStretch with commercial treatment planning systems indicate its applicability in clinical practice for dosimetric corrections in prostate calcifications. Its use during intraoperative ultrasound planning is foreseen. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

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

International Nuclear Information System (INIS)

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.

2011-01-01

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)

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)

Radial dose functions for 103Pd, 125I, 169Yb and 192Ir brachytherapy sources: an EGS4 Monte Carlo study

International Nuclear Information System (INIS)

Mainegra, E.

2000-01-01

Radial dose functions g(r) in water around 103 Pd, 125 I, 169 Yb and 192 Ir brachytherapy sources were estimated by means of the EGS4 simulation system and extensively compared with experimental as well as with theoretical results. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. Use of the point source approach produces reasonably accurate values of the radial dose function only at distances beyond 0.5 cm for 103 Pd sources. It is shown that binding corrections for Compton scattering have a negligible effect on radial dose function for 169 Yb and 192 Ir seeds and for 103 Pd seeds under 5.0 cm from the source centre and for the 125 I seed model 6702 under 8.0 cm. Beyond those limits there is an increasing influence of binding corrections on radial dose function for 103 Pd and 125 I sources. Results in solid water medium underestimate radial dose function for low-energy sources by as much as 6% for 103 Pd and 2.5% for 125 I already at 2 cm from source centre resulting in a direct underestimation of absolute dose rate values. It was found necessary to consider medium boundaries when comparing results for the radial dose function of 169 Yb and 192 Ir sources to avoid discrepancies due to the backscattering contribution in the phantom medium. Values of g(r) for all source types studied are presented. Uncertainties lie under 1% within one standard deviation. (author)

Application of 125I seed permanent plantation in osseous metastases

International Nuclear Information System (INIS)

Zhang Fujun; Wu Peihong; Lu Mingjian; Li Kui; Zhang Liang; Huang Jinhua; Fan Weijun; Zhao Ming; Gu Yangkui; Liu Jian; Wang Junjie

2007-01-01

Objective: To evaluate the value of 125 I permanent plantation in treating osseous metastases. Methods: Twenty-two patients with osseous metastases were accepted radioactive seeds 125 I permanent plantation. The curative effect was appraised according to the degree of ostalgia relieving and the changing of the radiology imaging in patients. Results: Accepted radioactive seeds 125 I permanent plantation, relief of pain was obtained and the effective rate is 91% (20/22). However none of the patients showed severe side-effect. Among 32 lesions in 22 cases followed-up by CT in 2 months, 4 obtained CR, 18 obtained PR, 10 NC and 0 PD. The responsive rate was 68.7%. Conclusion: 125 I permanent plantation procedure can be a safe and effective method in treating osseous metastases and obtaining good clinical effects with minimal damage and few complications. (authors)

Long term outcome and side effects in patients receiving low-dose I125 brachytherapy: a retrospective analysis

Directory of Open Access Journals (Sweden)

Pieter Logghe

Full Text Available ABSTRACT Objectives: To retrospectively evaluate the disease free survival (DFS, disease specific survival (DSS,overall survival (OS and side effects in patients who received low-dose rate (LDR brachytherapy with I125 stranded seeds. Materials and methods: Between july 2003 and august 2012, 274 patients with organ confined prostate cancer were treated with permanent I125 brachytherapy. The median follow-up, age and pretreatment prostate specific antigen (iPSA was 84 months (12-120, 67 years (50-83 and 7.8 ng/mL (1.14-38, respectively. Median Gleason score was 6 (3-9. 219 patients (80% had stage cT1c, 42 patients (15.3% had stage cT2a, 3 (1.1% had stage cT2b and 3 (1.1% had stage cT2c. The median D90 was 154.3 Gy (102.7-190.2. Results: DSS was 98.5%.OS was 93.5%. 13 patients (4.7% developed systemic disease, 7 patients (2.55% had local progression. In 139 low risk patients, the 5 year biochemical freedom from failure rate (BFFF was 85% and 9 patients (6.4% developed clinical progression. In the intermediate risk group, the 5 year BFFF rate was 70% and 5 patients (7.1% developed clinical progression. Median nPSA in patients with biochemical relapse was 1.58 ng/mL (0.21 – 10.46, median nPSA in patients in remission was 0.51 ng/mL (0.01 – 8.5. Patients attaining a low PSA nadir had a significant higher BFFF (p<0.05. Median D90 in patients with biochemical relapse was 87.2 Gy (51 – 143,1. Patients receiving a high D90 had a significant higher BFFF (p<0.05. Conclusion: In a well selected patient population, LDR brachytherapy offers excellent outcomes. Reaching a low PSA nadir and attaining high D90 values are significant predictors for a higher DFS.

Prostate cancer brachytherapy

International Nuclear Information System (INIS)

Abreu, Carlos Eduardo Vita; Silva, Joao L. F.; Srougi, Miguel; Nesrallah, Adriano

1999-01-01

The transperineal brachytherapy with 125 I/Pd 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

Evaluation of the dose distribution for prostate implants using various 125I and 103Pd sources

International Nuclear Information System (INIS)

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

2009-01-01

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

Development of procedure using plasma welding process to produce {sup 125}I seeds; Desenvolvimento de procedimento utilizando processo de soldagem plasma para confeccao de sementes de {sup 125}I

Energy Technology Data Exchange (ETDEWEB)

Feher, Anselmo

2006-07-01

The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer, is a problem of public health in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing {sup 125}I radioisotope are implanted in the prostate. 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 {sup 125}I. The plasma arc welding is one of the viable techniques for the sealing process. The equipment used in this technique is less costly than in other processes. The main objective of this work was the development and the validation of the welding procedure using plasma welding process and the elaboration of a sealing routine according to Good Manufacturing Practices. The development of this work has presented the following phases: cut and cleaning of the titanium material, determination of the welding parameters, development of a device for holding the titanium tube during the welding process, validation of sealed sources according to ISO 2919 Sealed Radioactive Sources - General Requirements and Classification, leakage test according to ISO 9978 Sealed Radioactive Sources - Leakage Test Methods and metallographic assays. The developed procedure, to seal {sup 125}I seeds using plasma welding process, has shown to be efficient, satisfying all the established requirements of ISO 2919. The results obtained in this work have given the possibility to establish a routine production process according to the orientations presented in resolution RDC number 59 - Good Manufacturing Practices do Medical Products of the ANVISA - Brazilian Nacional Agency of Sanitary Surveillance. (author)

Dosimetric intercomparison of permanent Ho-166 seed's implants and HDR Ir-192 brachytherapy in breast cancer.

Science.gov (United States)

de Campos, Tarcisio Passos Ribeiro; Nogueira, Luciana Batista; Trindade, Bruno; Cuperschmid, Ethel Mizrahy

2016-01-01

To provide a comparative dosimetric analysis of permanent implants of Ho(166)-seeds and temporary HDR Ir(192)-brachytherapy through computational simulation. Brachytherapy with Ir(192)-HDR or LDR based on temporary wires or permanent radioactive seed implants can be used as dose reinforcement for breast radiation therapy. Permanent breast implants have not been a practical clinical routine; although, I(125) and Pd(103)-seeds have already been reported. Biodegradable Ho(166)-ceramic-seeds have been addressed recently. Simulations of implants of nine Ho(166)-seeds and equivalent with HDR Ir(192)-brachytherapy were elaborated in MCNP5, shaped in a computational multivoxel simulator which reproduced a female thorax phantom. Spatial dose rate distributions and dose-volume histograms were generated. Protocol's analysis involving exposure time, seed's activities and dose were performed. Permanent Ho(166)-seed implants presented a maximum dose rate per unit of contained activity (MDR) of 1.1601 μGy h(-1) Bq(-1); and, a normalized MDR in standard points (8 mm, equidistant to 03-seeds - SP1, 10 mm - SP2) of 1.0% (SP1) and 0.5% (SP2), respectively. Ir(192)-brachytherapy presented MDR of 4.3945 × 10(-3) μGy h(-1) Bq(-1); and, 30% (SP1), and 20% (SP2). Therefore, seed's implant activities of 333 MBq (Ho(166)) and 259 GBq (Ir(192)) produced prescribed doses of 58 Gy (SP1; 5d) and 56 Gy (SP1, 5 fractions, 6 min), respectively. Breast Ho(166)-implants of 37-111 MBq are attractive due to the high dose rate near 6-10 mm from seeds, equivalent to Ir(192)-brachytherapy of 259 GBq (3 fractions, 6 min) providing similar dose in standard points at a week; however, with spatial dose distribution better confined. The seed positioning can be adjusted for controlling the breast tumor, in stages I and II, in flat and deep tumors, without any breast volumetric limitation.

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

Science.gov (United States)

Bakhshabadi, Mahdi; Ghorbani, Mahdi; Khosroabadi, Mohsen; Knaup, Courtney; Meigooni, Ali S

2016-02-01

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

Development of measurement method using TLD for workers occupation personally exposed to 125I seed source in the implant

International Nuclear Information System (INIS)

Luo Suming; He Zhijian; Yuan Jilong; Yue Baorong; Wei Kedao

2011-01-01

I seeds, the worker received the absorbed dose 0.09-14.29 μGy and effective dose 2.40-4.50 μSv outside lead aprons and the highest absorbed dose 7.77 μGy and effective 0.12 μSv inside lead aprons, respectively, with more than 34% of rays shielded. For one case of eye cancer with implantation of 125 I seeds, the workers received the absorbed dose 2.2-39.84 μGy and effective dose 4.48-10.06 μSv outside aprons and the highest absorbed dose 5.19 μGy and effective 0.16 μSv inside aprons, respectively, with more than 54.6 % of rays shielded. Conclusions: The method of using TLDs to measure the doses to the occupational workers in the course of the implantation of 125 I seed sources is simple and easy to operate. It would be an effective approach to protecting medical workers in the case of brachytherapy. (authors)

Seed-migration detector for embolized seeds to the lung in the context of permanent iodine-125 prostate brachytherapy

International Nuclear Information System (INIS)

Morrier, J.; Chretien, M.; Beaulieu, L.

2008-01-01

Full text: Purpose: To evaluate the efficacy of a seed-migration detector for embolized seeds to the lung in the context of permanent iodine-125 prostate brachytherapy and to compare its performance to fluoroscopy and to the postoperative chest radiographs generally recommended. Materials and Methods: A low energy gamma scintillation survey meter, Victoreen Model 425-110 was used together with a Victoreen count rate meter (model 190). It was converted to a seed-migration detector by adding a shield on the scintillation probe detection window, following the method proposed by Chen and Blair in 2003 [Med Phys 2003;30:785790]. The detector response to three seeds activities of iodine 125 (0.42, 0.22 and 0.06 mCi) was measured for different source-to-detector distances in air and in water. The detector was used to perform a chest evaluation on 579 patients at their first postoperative visit, for a total of 31 826 seeds. When the detector showed activity around a patients chest, it was confirmed by taking an antero-posterior chest radiograph and by looking at the region with fluoroscopy. Results: 79 patients (13.6%) present at least one embolized seed in the chest area. This account for 94 of the 31 826 seeds, that is a 0.30% seed migration rate. Sixty-eight, seven and four patients had respectively a single, two and three seeds embolization. In three cases, a seed had migrated in the kidney, which was confirmed with a CT scan. Of the 94 seeds, 67 (71%) were visible under fluoroscopy and 55 (59%) appeared on the chest radiograph. Rapid movement of the seeds in the chest area, due to breathing or to a location close to the heart or the diaphragm, makes nine seeds to be visible with fluoroscopy but not on the radiograph. This also explains why twenty-seven seeds were not visible with fluoroscopy neither with radiograph. In comparison to the seed-migration detector, detection based on fluoroscopy would have led to twenty-seven false-negative detections while the radiograph

Combination of multi-disciplinary techniques with 125I seeds in treating malignant obstructive jaundice

International Nuclear Information System (INIS)

Du Xueming; Xu Jianhui; Lang Jianhua; Tian Xiurong; Dong Wei

2008-01-01

Objective: To explore the effectiveness and safety of the combined multi-disciplinary techniques with 125 I seeds to treat the malignant obstructive jaundice. Methods: 18 cases:of malignant obstructive jaundice were divided into 2 groups. A group with ERBD technique followed by CT-guided interstitial 125 I seeds implantation, B group with 125 I seeds implantation during the operation and gallbladder-intestine anastomosis later on. After 2 months amelioration (CR, PR,SD, PD) of the obstructive jaundice was observed with inspection of liver functions. Results: All cases were ameliorated with 44% patients in group A and 56% patients in group B, showing no significant statistical difference (P>0.05); and the liver functions were also relieved in both groups with no statistical significance (P>0.05). Conclusion: Multi-disciplinary techniques combined with 125 I seeds implantation is effective in the management of the malignant obstructive jaundice. No significant difference for relief and liver function were found between CT-guided and during operation interstitial 125 I seeds implantations, but it seems more quickly relief or recovery was achieved in the latter. (authors)

Embolization of an iodine-125 radioactive seed from the prostate gland into the right ventricle: An unusual pattern of seed migration

International Nuclear Information System (INIS)

Schild, Michael H.; Wong, William W.; Vora, Sujay A.; Ward, Lynn D.; Nguyen, Ba D.

2009-01-01

Transperineal permanent brachytherapy using iodine-125 or palladium-103 seeds is a standard treatment modality for localized prostate cancer. Migration of seeds to the lungs is a common phenomenon, whereas migration of seeds to the right ventricle is a rare event. We report a case of iodine-125 seed migration to the right ventricle as demonstrated by chest CT scan and add to the very few published reports on this finding. These rare patients did not suffer adverse effects from such event.

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

Directory of Open Access Journals (Sweden)

Mahdi Bakhshabadi

2016-02-01

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

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)

Hospitalary inventory of prostatic sources of I-125; Inventario hospitalario de fuentes prostaticas de I-125

Energy Technology Data Exchange (ETDEWEB)

Barquero Sanz, R.; Anton, D.; Frutos Baraja, J. de.; Castillo Belmonte, A. del; Alonso, D.; Miquel, D. de; Lopez Lara-Martin, F.

2013-07-01

In accordance with the current regulations for radioactive facilities of brachytherapy, to carry out treatments of Prostate with I-125, must be a safety study involving evaluate maximum sources activity to use in the implants. In our installation was requested to perform implants permanent interstitial in prostate patients who tend to leaving the hospital in the hours following the intervention. The request which was prepared taking into account the maximum number predictable treatment (two per week), and to determine the activity to request, it was made the removal of seeds surplus by the supplier after each treatment. (Author)

American brachytherapy society recommends no change for prostate permanent implant dose prescriptions using iodine-125 or palladium-103

International Nuclear Information System (INIS)

Rivard, M.J.; Butler, W.M.; Merrick, G.S.; Devlin, P.M.; Hayes, J.K.; Hearn, R.A.; Lief, E.P.; Meigooni, A.S.; Williamson, J.F.

2008-01-01

Purpose - In 2004, the American Association of Physicists in Medicine (AAPM) issued a report outlining recommended 125 I and 103 Pd datasets for consistency in calculating brachytherapy dose distributions. In 2005, to aid evaluating the clinical impact of implementing these datasets, the AAPM assessed the historical dependence of how prescribed doses differed from administered doses for 125 I and 103 Pd for permanent implantation of the prostate. Consequently, the American Brachytherapy Society (ABS) considered the nature of these changes towards issuing recommended dose prescriptions for 125 I and 103 Pd interstitial brachytherapy implants for mono-therapy and standard boosts. Methods and materials - An investigation was performed of the 2005 AAPM analysis to determine changes in administered dose while affixing prescribed dose using 2004 AAPM 125 I and 103 Pd brachytherapy dosimetry datasets for prostate implants. For 125 I and 103 Pd, administered dose would change by +1.4% and +4.2%, respectively. The biological and societal impact of changing prescribed dose was considered. Results - Based on the need for clinical constancy and in recognition of overall uncertainties, the ABS recommends immediate implementation of the 2004 AAPM consensus brachytherapy dosimetry datasets and no changes to 125 I and 103 Pd dose prescriptions at this time. Conclusions - Radiation oncologists should continue to prescribe mono-therapy doses of 145 Gy and 125 Gy for 125 I and 105 Pd, respectively, and standard boost doses of 100-110 Gy and 90-100 Gy for 125 I and 103 Pd, respectively. (authors)

Staff dose of hospitalization in the treatment of patients in ophthalmic brachytherapy with 125 I

International Nuclear Information System (INIS)

Terron Leon, J. A.; Gomez Palacios, M.; Moreno Reyes, J. C.; Perales Molina, A.

2013-01-01

The objective of this work, therefore, has been the evaluation of the dose levels which nursing staff can receive in care for ophthalmic brachytherapy patients treated with 125 I from measurements made on the same, evaluating, in an experimental way, job security following the PR rules laid down for these treatments. (Author)

Efficacies of 125I seed implantation in advanced stage central lung cancer via fibrobronchoscope

International Nuclear Information System (INIS)

Liu Jianguo; An Liqing; Cheng Jinguang; Zhang Yufen; Guo Xiaokui

2009-01-01

Objective: To explore the temporal curative effect of 125 I seed implantation in advanced stage central type lung cancer. Methods: 125 I seed was implanted in 56 patients confirmed advanced stage central type lung cancer via fibrobronchoscope and all cases were fellow up in certain duration to explore their efficacies and the adverse reaction. Results: Total efficient rate was 76.78% in 56 patients. Lung reexpanded rate was 90.90%. Conclusion: The therapy of 125 I seed implantation in advanced stage central type lung cancer is safe and available. (authors)

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.)

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Leakage test evaluation used for qualification of iodine-125 seeds sealing

International Nuclear Information System (INIS)

Feher, Anselmo; Rostelato, Maria E.C.M.; Zeituni, Carlos A.; Calvo, Wilson A.P.; Somessari, Samir L.; Moura, Joao A.; Moura, Eduardo S.; Souza, Carla D.; Rela, Paulo R.

2009-01-01

The prostate cancer is a problem of public health in Brazil, and the second cause of cancer deaths in men, exceeded only by lung cancer. Among the possible treatments available for prostate cancer is brachytherapy, in which small seeds containing Iodine-125 radioisotope are implanted in the prostate. The seed consists of a sealed titanium tube measuring 0.8 mm external diameter and 4.5 mm in length, containing a central silver wire with adsorbed Iodine-125. The tube sealing is made with titanium at the ends, using electric arc welding or laser process. This sealing must be leakage-resistant and free of cracks, therefore avoiding the Iodine-125 to deposit in the silver wire to escape and spread into the human body. To ensure this problem does not occur, rigorous leakage tests, in accordance with the standard Radiation protection - Sealed Radioactive Sources - leakage Test Methods - 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 the 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 seeds leakage tests. Forty-eight seeds were welded for these tests. (author)

Dosimetry on ocular brachytherapy with ROPES plaque with Iodine-125 and Palladium-103 seeds; Dosimetria em braquiterapia ocular com placa ROPES contendo sementes de iodo-125 e paladium-103

Energy Technology Data Exchange (ETDEWEB)

Mourao, Arnaldo P. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET/MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar], e-mail: aprata@des.cefetmg.br; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares

2010-03-15

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)

SU-E-T-123: Anomalous Altitude Effect in Permanent Implant Brachytherapy Seeds

International Nuclear Information System (INIS)

Watt, E; Spencer, DP; Meyer, T

2015-01-01

Purpose: Permanent seed implant brachytherapy procedures require the measurement of the air kerma strength of seeds prior to implant. This is typically accomplished using a well-type ionization chamber. Previous measurements (Griffin et al., 2005; Bohm et al., 2005) of several low-energy seeds using the air-communicating HDR 1000 Plus chamber have demonstrated that the standard temperature-pressure correction factor, P TP , may overcompensate for air density changes induced by altitude variations by up to 18%. The purpose of this work is to present empirical correction factors for two clinically-used seeds (IsoAid ADVANTAGE™ 103 Pd and Nucletron selectSeed 125 I) for which empirical altitude correction factors do not yet exist in the literature when measured with the HDR 1000 Plus chamber. Methods: An in-house constructed pressure vessel containing the HDR 1000 Plus well chamber and a digital barometer/thermometer was pumped or evacuated, as appropriate, to a variety of pressures from 725 to 1075 mbar. Current measurements, corrected with P TP , were acquired for each seed at these pressures and normalized to the reading at ‘standard’ pressure (1013.25 mbar). Results: Measurements in this study have shown that utilization of P TP can overcompensate in the corrected current reading by up to 20% and 17% for the IsoAid Pd-103 and the Nucletron I-125 seed respectively. Compared to literature correction factors for other seed models, the correction factors in this study diverge by up to 2.6% and 3.0% for iodine (with silver) and palladium respectively, indicating the need for seed-specific factors. Conclusion: The use of seed specific altitude correction factors can reduce uncertainty in the determination of air kerma strength. The empirical correction factors determined in this work can be applied in clinical quality assurance measurements of air kerma strength for two previously unpublished seed designs (IsoAid ADVANTAGE™ 103 Pd and Nucletron selectSeed 125 I

SU-E-T-123: Anomalous Altitude Effect in Permanent Implant Brachytherapy Seeds

Energy Technology Data Exchange (ETDEWEB)

Watt, E; Spencer, DP; Meyer, T [University of Calgary and Tom Baker Cancer Centre, Calgary, AB (Canada)

2015-06-15

Purpose: Permanent seed implant brachytherapy procedures require the measurement of the air kerma strength of seeds prior to implant. This is typically accomplished using a well-type ionization chamber. Previous measurements (Griffin et al., 2005; Bohm et al., 2005) of several low-energy seeds using the air-communicating HDR 1000 Plus chamber have demonstrated that the standard temperature-pressure correction factor, P{sub TP}, may overcompensate for air density changes induced by altitude variations by up to 18%. The purpose of this work is to present empirical correction factors for two clinically-used seeds (IsoAid ADVANTAGE™ {sup 103}Pd and Nucletron selectSeed {sup 125}I) for which empirical altitude correction factors do not yet exist in the literature when measured with the HDR 1000 Plus chamber. Methods: An in-house constructed pressure vessel containing the HDR 1000 Plus well chamber and a digital barometer/thermometer was pumped or evacuated, as appropriate, to a variety of pressures from 725 to 1075 mbar. Current measurements, corrected with P{sub TP}, were acquired for each seed at these pressures and normalized to the reading at ‘standard’ pressure (1013.25 mbar). Results: Measurements in this study have shown that utilization of P{sub TP} can overcompensate in the corrected current reading by up to 20% and 17% for the IsoAid Pd-103 and the Nucletron I-125 seed respectively. Compared to literature correction factors for other seed models, the correction factors in this study diverge by up to 2.6% and 3.0% for iodine (with silver) and palladium respectively, indicating the need for seed-specific factors. Conclusion: The use of seed specific altitude correction factors can reduce uncertainty in the determination of air kerma strength. The empirical correction factors determined in this work can be applied in clinical quality assurance measurements of air kerma strength for two previously unpublished seed designs (IsoAid ADVANTAGE™ {sup 103}Pd and

Relative biological effectiveness of 125I seeds for low-dose-rate irradiation of PANC-1

International Nuclear Information System (INIS)

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

2008-01-01

Objective: To investigate the relative biological effectiveness(RBE) of National Model 6711 125 I seeds and the response patterns of PANC-1 exposed to 125 I seeds irradiation. Methods: PANC-1 cells in exponential growth were irradiated at initial dose rate of 2.59 cGy/h in vitro and exposed to 1, 2, 4, 6, 8 and 10 Gy. Meanwhile, the other part of cells were exposed to the same doses by 60 Co at dose rate of 2.21 Gy/min. After irradiation, the cells were stained by trypan blue to measure the cellular mortality rate and to compare the changes along with plating times of 12, 24, 48 and 72 h after 4 Gy. The colonies were counted to obtain the plating efficiencies by colony-forming assay and the cell surviving faction was calculated to plot cell survival curves, and RBE of 125 I seeds relative to 60 Co was determined. Results: The cell death rate for continuous low- dose-rate (LDR) irradiation by 125 I seeds was greater than 60 Co at the same doses above or equal to 4 Gy. After 4 Gy irradiation, the cellular mortality rates were increased with times. The difference was significant between 125 I seeds and 60 Co. The survival fractions of 125 I were lower than those of 60 Co, and the RBE of 125 I relative to 60 Co was determined to be 1.45. Conclusion: The cell-killing effects for continuous low-dose-rate (LDR) irradiation by 125 I seeds are greater than acute high-dose-rate of 60 Co. (authors)

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

International Nuclear Information System (INIS)

Stannard, Clare E.; Hering, Egbert; Hough, Jan; Knowles, Ruth; Munro, Roger; Hille, Jos

2004-01-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

Low-intensity radioactive sources emitting low-energy photons are used in the clinic for low dose-rate brachytherapy treatments of tumours. The dosimetry of these sources is based on reference air kerma rate measurements. The absorbed dose rate to water at the reference depth d 0 = 1 cm, D w , 1 cm, is then obtained by a conversion procedure with a large relative standard uncertainty of about 5%. This paper describes a primary standard developed at ENEA-INMRI to directly measure D w , 1 cm due to LDR sources. The standard is based on a large-angle and variable-volume ionization chamber, embedded in a graphite phantom and operating under 'wall-less air chamber' conditions. A set of correction and conversion factors, based on experiments and Monte Carlo simulations, are determined to obtain the value of D w , 1 cm from measurements of increment of ionization current with increasing chamber volume. The relative standard uncertainty on D w , 1 cm is 2.6%, which is appreciably lower than the current uncertainty. Characteristics of the standard, its associated uncertainty budget, and some experimental results are given for 125 I BEBIG I25.S16.C brachytherapy seeds. Finally, results of the experimental determination of the dose-rate constant 1 cm, traceable to the D w , 1 cm and the low-energy air kerma ENEA-INMRI standards, are given. The relative standard uncertainty on 1 cm is 2.9%, appreciably lower than the typical uncertainty (4.8%) of the values available in the literature. (authors)

Experimental and theoretical determination of dosimetric characteristics of IsoAid ADVANTAGETM125I brachytherapy source

International Nuclear Information System (INIS)

Meigooni, Ali S.; Hayes, Joshua L.; Zhang Hualin; Sowards, Keith

2002-01-01

125 I brachytherapy sources are being used for interstitial implants in tumor sites such as the prostate. Recently, the ADVANTAGE TM 125 I, Model IAI-125, source became commercially available for interstitial brachytherapy treatment. Dosimetric characteristics (dose rate constant, radial dose function, and anisotropy function) of this source were experimentally and theoretically determined, following the AAPM Task Group 43 recommendations. Derivation of the dose rate constant was based on recent NIST WAFAC calibration performed in accordance with their 1999 standard. Measurements were performed in Solid Water TM phantom using LiF thermoluminescent dosimeters. The theoretical calculations were performed in both Solid Water TM and water using the PTRAN Monte Carlo code. The results indicated that a dose rate constant of the new source in water was 0.98±0.03 cGy h -1 U -1 . The radial dose function of the new source was measured in Solid Water TM and calculated both in water and Solid Water TM at distances up to 10.0 cm. The anisotropy function, F(r,θ), of the new source was measured and calculated in Solid Water TM at distances of 2 cm, 3 cm, 5 cm, and 7 cm and also was calculated in water at distances ranging from 1 cm to 7 cm from the source. From the anisotropy function, the anisotropy factors and anisotropy constant were derived. The anisotropy constant of the ADVANTAGE TM 125 I source in water was found to be 0.97±0.03. The dosimetric characteristics of this new source compared favorably with those from the Amersham Health Model 6711 source. Complete dosimetric parameters of the new source are presented in this paper

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

International Nuclear Information System (INIS)

Mourao, A.P.; Campos, T.P.R.

2008-01-01

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)

Effect of 125I seeds and 103Pd stents on proliferation of vascular smooth muscle cells

International Nuclear Information System (INIS)

Zhu Jun; Zhu Ruisen

2004-01-01

To establish the theoretical and practical base for implementing radioactive stents aft PTCA in order to prevent restenosis, in vitro observation was taken over the effects of 12 '5I-seeds and 103 Pd-implanted stents on the vascular smooth muscle cell (VSMC) proliferation. In vitro VSMC model from guinea-pig aortic arteries was established using adherent cell culture methods. The effects of 125 I-seeds and 103 Pd-implanted stents on the VSMC proliferation, with or without fetal bovine serum (FCS), were investigated through cell counting methods and 3 H-TDR implementation tests. It was shown that (1) 10% FCS significantly promoted the DNA synthesis of VSMC (P 125 I-seeds and 103 Pd-implanted stents inhibited the VSMC DNA synthesis in dose-dependent manner, regardless of 10% FCS inducement. At lower radioactive doses, neither 125 I-seeds (18.5-74 kBq) nor 103 Pd-implanted stents (1.48-2.96 MBq) exhibited distinctive effects on the VSMC DNA synthesis (P>0.05); and (3) 48 hour exposure from 125 I-seeds at 128 kBq or 10 '3Pd-implanted stents at 7.4 MBq did not result in VSMC morphological alteration, but 125 I-seeds at 370 kBq caused cells' morphological changes. Therefore both 125 I-seeds and 103 Pd-implanted stents inhibit the in vitro VSMC DNA synthesis, and the inhibition effects are significantly related to their exposure duration and doses. (authors)

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Therapeutic value of 3-D printing template-assisted 125I-seed implantation in the treatment of malignant liver tumors

Directory of Open Access Journals (Sweden)

Han T

2017-07-01

Full Text Available Tao Han,1,* Xiaodan Yang,1,* Ying Xu,2,* Zhendong Zheng,1,* Ying Yan,2 Ning Wang2 1Department of Oncology, 2Department of Radiotherapy, General Hospital of Shenyang Military Region, Shenyang, China *These authors contributed equally to this work Objective: To explore the therapeutic value of 3-D printing template-assisted 125I-seed implantation in the treatment of malignant liver tumors.Materials and methods: Fifteen liver cancer patients with 47 total lesions were treated with 3-D printing template-assisted radioactive seed implantation (group A, and 25 liver-tumor patients with 66 total lesions were treated with 125I-seed implantation without a template auxiliary (group B. Operation time, in-hospital time, operation complications, dose distribution, and response rate (number were compared between the two groups. Results: Shorter operation times and better dose distribution were observed in group A than in group B, and the differences were statistically significant. The response rate after 2 months was 86.7% (13 of 15 in group A and 84% (21 of 25 in group B; differences between the two groups were not significant.Conclusion: Application of 3-D printing template-assisted radioactive seed implantation in the treatment of malignant liver tumors can help shorten operation time and optimize radiation-dose distribution, is worthy of further study, and has clinical significance. Keywords: brachytherapy, stereotactic techniques, iodine isotopes, liver, carcinoma 

Quality Assurance Procedure Development in Iodine-125 Seeds Production

International Nuclear Information System (INIS)

Moura, J.A.; Moura, E.S.; Sprenger, F.E.

2009-01-01

Brachytherapy using Iodine-125 seeds has been used in prostate cancer treatment. In the quality control routine during seed production, leak tests are made to detect any leakage of radioactive material from inside the titanium shield. Leak tests are made according to the International Standard Organization- Radiation protection - sealed radioactive sources - ISO 9978 standard, and require liquid transfer between recipients. If any leakage happens, there will be contamination of the liquid and tubing. This study aims to establish decontamination routines for tubing, allowing its repeated use, in the automated assay process

Dosimetric comparison of seed strength for I-125 prostate implants

International Nuclear Information System (INIS)

Elliott, S.; Droege, J.; Beaufort, C.

2004-01-01

Full text: The strength of 1-125 seeds for prostate brachytherapy has been a topic of increasing popularity in the literature over the last few years. Recent reports, which include planning and clinical studies, compare dosimetry between plans and implants using higher (0.5 - 0.8 U, where IU = I μGym 2 h -1 ) or lower (0.3 - 0.4 U) seed strength. The majority of these studies support higher seed strengths for obtaining optimal dosimetry. At the WBRC, a seed air kerma strength of just under 0.4 U is currently used for seed implants. The purpose of this work is to investigate the use of higher strength seeds for our prostate implants. Twenty-four patients were selected according to prostate size, and re-planned using a seed strength of 0.5 U or 0.6 U. Planning was performed following our standard preplanning guidelines as closely as possible; that is, manual planning using a modified Seattle approach and dosimetry limits for the target volume of D 100 : > 95 Gy, v 100 > 98 %, V 150 : 52 - 62 % and V 200 : 11 - 16 %. Dosimetry from the original preplans was then compared to the dosimetry from the re-planned cases. Satisfactory dosimetry was obtained using 0.5 U or 0.6 U strength seeds. Seed placement was typically around the periphery of the target on all slices, to avoid overdosing the urethra. The mean D 100 (Gy) is marginally improved with the higher seed strength. As expected, the V200 (%) is also higher. The mean number of seeds required per implant decreased by 16 % and 28 % for 0.5 U and 0.6 U seeds respectively. The mean number of needles decreased by 7 needles for 0.6 U seeds, however only by 3 needles for 0.5 U seeds. Rectal doses, when using the higher strength seeds, were easily constrained to less than the original preplan doses. Although there was no apparent trend in dosimetry statistics with volume size, as a function of seed strength, it was noted that the reduction in needle and seed number was most significant for medium and large target volumes. A

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

International Nuclear Information System (INIS)

Somessari, Samir L.; Feher, Anselmo; Sprenger, Francisco E.; Rostellato, Maria E.C.M.; Moura, Joao A.; Costa, Osvaldo L.; Calvo, Wilson A.P.

2011-01-01

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)

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)

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

International Nuclear Information System (INIS)

Santos, Adriano M.; Meira-Belo, Luiz C.; Reis, Sergio C.; Grynberg, Suely E.

2011-01-01

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)

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)

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

Hospitalary inventory of prostatic sources of I-125

International Nuclear Information System (INIS)

Barquero Sanz, R.; Anton, D.; Frutos Baraja, J. de.; Castillo Belmonte, A. del; Alonso, D.; Miquel, D. de; Lopez Lara-Martin, F.

2013-01-01

In accordance with the current regulations for radioactive facilities of brachytherapy, to carry out treatments of Prostate with I-125, must be a safety study involving evaluate maximum sources activity to use in the implants. In our installation was requested to perform implants permanent interstitial in prostate patients who tend to leaving the hospital in the hours following the intervention. The request which was prepared taking into account the maximum number predictable treatment (two per week), and to determine the activity to request, it was made the removal of seeds surplus by the supplier after each treatment. (Author)

1251 seed calibration using afterloading equipment Seed Selectron. Practical solution to meet the recommendations of the AAPM; Calibracion de semillas de {sup 1}25I usando el equipo de carga difereida SeedSelectron. Solucion practica para cumplir las recomendaciones de la AAPM

Energy Technology Data Exchange (ETDEWEB)

Perez-Calatayud, J.; Richart, J.; Perez-Garcia, J.; Guirado, D.; Ballester, F.; Rodriguez, S.; Santos, M.; Depiaggio, M.; Carmona, V.; Lliso, F.; Camacho, C.; Pujades, M. C.

2011-07-01

Seed Selectron is a system used in the after loader permanent implant brachytherapy seeds 1-125 interstitial prostate. Two aspects are critical when you can meet the recommendations of the AAPM: a practical difficulty to check the quantity of seed required, and the great uncertainty of all measured diodes. The purpose of this paper is to present a practical solution that has been adopted to implement the recommendations of the AAPM.

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

International Nuclear Information System (INIS)

Mourao, Arnaldo P.; Campos, Tarcisio P.R.

2009-01-01

Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for departuring absorbed doses in tumor minimizing doses in the lens and the adjacent tissues of the eyeball (orbital region), avoiding deleterious effects. Thus, a three-dimensional computational voxel model and an analytical model were coupled, including the heterogeneous properties of the globe and the adjacent tissues. The analytical model was applied to define the thin structures of the ocular globe. This computational model is used to simulate orbital irradiation with ROPES and COMS ophthalmologic plaques placed on the sclera surface filled to ten and eight iodine-125 seeds, respectively. Simulations are performed on the MCNP5 code. The computational simulation allows evaluating how the dose rates are spatially distributed in the orbital volume. The results are normalized to 100% at the maximum dose on the tumor base, and by the applied source activity. The external globe structures receive 0.5% of the maximum internal dose. The crystalline lens dosimetry depends on the position and thickness of the tumor and the plaque diameters. On the present case, 12.75% of maximum dose is found on the lens. The maximum dose is found onto the eyeball, in the vitreous. The present model represents an advance in simulating and predicting absorbed dose on ocular brachytherapy, incorporating anthropomorphic and anthropometric features of the real eyeball. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Mourao, Arnaldo P. [Centro Federal de Educacao Tecnoloica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar], e-mail: aprata@des.cefetmg.br; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares], e-mail: campos@nuclear.ufmg.br

2009-07-01

Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for departuring absorbed doses in tumor minimizing doses in the lens and the adjacent tissues of the eyeball (orbital region), avoiding deleterious effects. Thus, a three-dimensional computational voxel model and an analytical model were coupled, including the heterogeneous properties of the globe and the adjacent tissues. The analytical model was applied to define the thin structures of the ocular globe. This computational model is used to simulate orbital irradiation with ROPES and COMS ophthalmologic plaques placed on the sclera surface filled to ten and eight iodine-125 seeds, respectively. Simulations are performed on the MCNP5 code. The computational simulation allows evaluating how the dose rates are spatially distributed in the orbital volume. The results are normalized to 100% at the maximum dose on the tumor base, and by the applied source activity. The external globe structures receive 0.5% of the maximum internal dose. The crystalline lens dosimetry depends on the position and thickness of the tumor and the plaque diameters. On the present case, 12.75% of maximum dose is found on the lens. The maximum dose is found onto the eyeball, in the vitreous. The present model represents an advance in simulating and predicting absorbed dose on ocular brachytherapy, incorporating anthropomorphic and anthropometric features of the real eyeball. (author)

CT-guided radioactive 125I-seed implantation for the treatment of pancreatic carcinoma: a clinical observation of 19 cases

International Nuclear Information System (INIS)

Lu Jian; Zheng Yunfeng; Zhang Huan; Wang Zhongmin; Chen Kemin

2010-01-01

Objective: To explore the dynamic changes of serum tumor markers after CT-guided radioactive 125 I-seed implantation treatment in patients with pancreatic carcinoma and to assess the therapeutic effectiveness of 125 I-seed implantation. Methods: CT-guided radioactive 125 I-seed implantation was performed in 19 patients with unresectable advanced pancreatic cancer. Treatment planning system was used to reconstruct 3-dimentional images of the tumor, and the quantity and distribution of 125 I-seeds to be implanted were thus determined. Under CT guidance 125 I-seeds were embedded into pancreatic cancer. Before and after the 125 I-seed implantation the levels of serum tumor markers, including CEA, CA19-9 and CA50, were determined by using radioimmunoassay method. The clinical effects were observed and the therapeutic results were statistically analyzed. Results: The pain stared to be relieved 2 to 5 days after implantation. The total effective rate (CR + PR) at one and three months after treatment was 68.42% (13 /19) and 63.16% (12 /19) respectively. One month after 125 I-seed implantation, the levels of serum CEA, CA19-9 and CA50 were significantly different to that determined before implantation in all cases (P 125 I-seed implantation is a safe and effective interventional treatment for advanced pancreatic cancer with reliable short-term result and remarkable pain-relieving effect. Moreover, this therapy can significantly lower the levels of many serum tumor markers, which play some suggestive roles in evaluating the clinical curativeness. (authors)

Self-expandable stent loaded with {sup 125}I seeds: Feasibility and safety in a rabbit model

Energy Technology Data Exchange (ETDEWEB)

Guo Jinhe [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Teng Gaojun [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China)]. E-mail: gjteng@vip.sina.com; Zhu Guangyu [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); He Shicheng [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Deng Gang [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); He Jie [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China)

2007-02-15

Objective: To evaluate technical feasibility and acute and subacute radiotolerance of a self-expandable stent loaded with {sup 125}I seeds in the rabbit esophagus. Methods: A self-expandable stent designed for esophageal application was made of 0.16 mm nitinol wire and loaded with {sup 125}I seeds (CIAE-6711). Twenty-seven stents with three different radioactive dosages (n = 9 in each dosage group) were implanted in the esophagus of healthy rabbits, while nine stents alone were used as controls. The stents were perorally deployed into the esophagus under fluoroscopic guidance. Radiological follow-up included plain chest film, CT scan, and barium esophagography which were undertaken in all rabbits of each group at 2, 4, and 8 weeks, respectively, which were correlated to histopathological findings. The stented esophageal segments along with their adjacent tissues were harvested for histopathological examinations. Results: The stent was successfully deployed into the targeted esophageal segment in all rabbits. Neither {sup 125}I seeds dislodged from the stent during the deployment, nor they did during the follow-up period. The greatest (16.2 Gy) absorbed dose was found in the tissue 10 mm from {sup 125}I seeds at 8 weeks. Slight epithelial hyperplasia on the stent surface and submucosal inflammatory process developed at 2 weeks, which reached the peak at 8 weeks after the procedure. Significant thickness of the esophageal muscular layer was found at 8 weeks only in the groups with {sup 125}I seeds. On radiologic follow-up, moderate strictures on both ends of the stents developed at 4 weeks and became severe at 8 weeks after the procedure in all groups. Conclusion: Deployment of a self-expandable stent loaded with {sup 125}I seeds is technically feasible and safe within the first 8 weeks. Acute and subacute radiotolerance of the treated esophagus and its adjacent tissues by {sup 125}I seeds is well preserved in a healthy rabbit model.

Microdosimetric evaluation of relative biological effectiveness for 103PD, 125I, 241AM, and 192IR brachytherapy sources

International Nuclear Information System (INIS)

Wuu, C.S.; Kliauga, P.; Zaider, M.; Amols, H.I.

1996-01-01

Purpose: To determine the microdosimetric-derived relative biological effectiveness (RBE) of 103 Pd, 125 I, 241 Am, and 192 Ir brachytherapy sources at low doses and/or low dose rates. Methods and Materials: The Theory of Dual Radiation Action can be used to predict expected RBE values based on the spatial distribution of energy deposition at microscopic levels from these sources. Single-event lineal energy spectra for these isotopes have been obtained both experimentally and theoretically. A grid-defined wall-less proportional counter was used to measure the lineal energy distributions. Unlike conventional Rossi proportional counters, the counter used in these measurements has a conducting nylon fiber as the central collecting anode and has no metal parts. Thus, the Z-dependence of the photoelectric effect is eliminated as a source of measurement error. Single-event spectra for these brachytherapy sources have been also calculated by: (a) the Monte Carlo code MCNP to generate the electron slowing down spectrum, (b) transport of monoenergetic electron tracks, event by event, with our Monte Carlo code DELTA, (c) using the concept of associated volume to obtain the lineal energy distribution f(y) for each monoenergetic electron, and (d) obtaining the composite lineal energy spectrum for a given brachytherapy source based on the electron spectrum calculated at step (a). Results: Relative to 60 Co, the RBE values obtained from this study are: 2.3 for 103 Pd, 2.1 for 125 I, 2.1 for 241 Am, and 1.3 for 192 Ir. Conclusions: These values are consistent with available data from in vitro cell survival experiments. We suggest that, at least for these brachytherapy sources, microdosimetry may be used as a credible alternative to time-consuming (and often uncertain) radiobiological experiments to obtain information on radition quality and make reliable predictions of RBE in low dose rate brachytherapy

Radioactive seed immobilization techniques for interstitial brachytherapy

International Nuclear Information System (INIS)

Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y.; Messing, E.; Rubens, D.; Sarkar, N.; Ng, W.

2008-01-01

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.)

The clinical application of TACE together with RFA and 125I seed implantation in treating hepatocellular carcinoma

International Nuclear Information System (INIS)

Xie Xiaoxi; Lu Yinxiang; Zhang Hongxin; Zhang Shengchu; Zhou Jianwei; Zhang Guodong; Wang Xiaowei; Yang Liping

2011-01-01

Objective: to assess the clinical value of the combined treatment of transcatheter arterial chemoembolization (TACE), CT-guided radiofrequency ablation (RFA) and radioactive 125 I seed implantation for hepatocellular carcinoma (HCC). Methods: During the period from March 2008 to Dec. 2010, 15 patients with HCC were admitted to the hospital. A total of 25 hepatic lesions were detected with the size of 1-8 cm. TACE was carried out first, which was followed by CT-guided RFA and radioactive 125 I seed implantation. With the help of treat plan system (TPS), the radioactive 125 I seed implantation was conducted to make additional management for the same lesion when RFA was finished, or the radioactive 125 I seeds were directly implanted into the areas where RFA could not reach. The radioactive dose was 60-100 Gy. All the patients were followed up and were kept under observation for the signs of related complications. The therapeutic results were evaluated. Results: The combined treatment was successfully accomplished in all patients. All patients were followed up for 3-28 months (mean of 10.6 months). The complete necrosis rate of the tumor was 96%. No serious complications occurred except the immigration of 125 I seeds in 1 case. Conclusion: The combined treatment of TACE and CT-guided RFA together with 125 I seed implantation is a safe, reliable and effective therapy for HCC with excellent short-term result. (authors)

Early therapy monitoring of 125I seed interstitial implant in a pancreatic cancer xenograft by 18F-FDG Micro-PET/CT

International Nuclear Information System (INIS)

Wang Zhongmin; Liu Yu; Chen Kemin; Lu Jian; Gong Ju; Zheng Yunfeng; Zhang Liyun; Liu Fenju

2011-01-01

noninvasive imaging modality to assess early response to 125 I seed brachytherapy in a pancreatic cancer xenograft. (authors)

125I brachytherapy of locally advanced non-small-cell lung cancer after one cycle of first-line chemotherapy：a comparison with best supportive care

Directory of Open Access Journals (Sweden)

Song J

2017-03-01

NSCLC and quality of life after one cycle of first-line chemotherapy compared with best supportive care. Keywords: non-small-cell lung cancer, CT-guided intervention, 125I seed, brachytherapy 

Staff dose of hospitalization in the treatment of patients in ophthalmic brachytherapy with 125 I; Dosis al personal de hospitalizacion en el tratamiento de pacientes de braquiterapia oftalmica con I-125

Energy Technology Data Exchange (ETDEWEB)

Terron Leon, J. A.; Gomez Palacios, M.; Moreno Reyes, J. C.; Perales Molina, A.

2013-07-01

The objective of this work, therefore, has been the evaluation of the dose levels which nursing staff can receive in care for ophthalmic brachytherapy patients treated with 125 I from measurements made on the same, evaluating, in an experimental way, job security following the PR rules laid down for these treatments. (Author)

Ropes eye plaque brachytherapy dosimetry for two models of 103Pd seeds

International Nuclear Information System (INIS)

Saidi, P.; Sadeghi, M.; Shirazi, A.; Tenreiro, C.

2011-01-01

Full text: Brachytherapy dose distributions are calculated for I5 m m ROPES eye plaque loaded with model Theragenics200 and IR06-103Pd seeds. The effects of stainless steel backing and Acrylic insert on dose distribution along the central axis of the eye plaque and at critical ocular structure are investigated. Monte Carlo simulation was carried out with the Version 5 of the MCNP. The dose at critical ocular structure by considering the eye composition was calculated. Results are compared with the calculated data for CaMS eye plaque loaded with Theragenics200 palladium-103 seeds and model 6711 iodine-125 seed. The air kerma strength of the IR06- 103Pd seed to deliver 85 Gy in apex of tumor in water medium was calculated to be 4.10 U/seed. Along the central axis of stainless steel plaque loaded with new 103Pd seeds in Acrylic insert, the dose reduction relative to water is 6.9% at 5 mm (apex). Removal of the Acrylic insert from the plaque (replacing with water) did not make significantly difference in dose reduction results (O.2%). The presence of the stainless steel backing results in dose enhancement near the plaque relative to water. Doses at points of interest are higher for ROPES eye plaque when compared to CaMS eye plaque. The dosimetric parameters calculated in this work for the new palladium seed, showed that in dosimetry point of view, the IR06-103Pd seed is suitable for use in brachytherapy. The effect of Acrylic insert on dose distribution is negligible and the main effect on dose reduction is due to the presence of stainless steel plaque backing. (author)

Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

International Nuclear Information System (INIS)

Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

2010-01-01

Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had 125 I and 638 patients had 103 Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline α-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm 3 , 25-45 cm 3 , 3 ; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline α-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

Side effects of permanent I125 prostate seed implants in 667 patients treated in Leeds

International Nuclear Information System (INIS)

Bottomley, David; Ash, Dan; Al-Qaisieh, Bashar; Carey, Brendan; Joseph, Joji; St Clair, Shaun; Gould, Kathy

2007-01-01

Purpose: To report the side effects and complications after I-125 seeds prostate implant after 8.5 years experience. Methods and materials: Six hundred and sixty seven (667) patients were treated between March 1995 and December 2001. The median follow up is 31 months with a maximum of 98.2 months. Morbidity data were collected from a review of patient case-notes. Patients also provided prospective data on urinary symptoms using the International Prostate Symptom Score (IPSS) scoring chart before treatment and at regular follow up. Patients were also sent a questionnaire detailing symptoms and side effects following their brachytherapy. This enabled them to record urinary, bowel and sexual function side effects independently. Logistic regression analysis was carried out to identify the risk of catheterisation in relation to the pre-implant prostate volume and potential implant factors such as the number of seeds and needles and implant dose. Result: The urinary symptom score rises in the first few months after implantation and returns to within one or two points of the pre-treatment score within one year. Nine patients reported incontinence prior to treatment and 15, 12 and 10 patients reported incontinence 6, 12 and 24 months after treatment, respectively. Catheterisation was reported in 97 (14.5%) patients. At six months 84.9% of patients reported no change in bowel function and 78.9% at 12 months. 6.4% of patients complained of some increased bowel frequency at 6 months and 5.7% at 12 months. 402 (77.2%) patients reported being fully potent before treatment and that this fell to 32.4% after treatment. Logistic regression showed that the most significant factors which correlate with the probability of catheterisation are the pre-treatment prostate volume and the number of seeds and needles implanted. Conclusion: The side effects and complications after prostate brachytherapy as reported here and elsewhere confirm that the treatment is not only convenient but also

Preparation and administration of I-125 labeled seeds for localization of nonpalpable breast lesions

DEFF Research Database (Denmark)

Langhans, Linnea; Klausen, Thomas Levin; Tvedskov, Tove Holst Filtenborg

2016-01-01

Radioactive seed localization (RSL) is a new technique for surgical identification of nonpalpable breast lesions. We describe the preparation of the needle with I-125 seeds for ultrasound-guided deposition in breast lesions. In a feasibility study we investigated the minimum activity amount needed...... for reliable gamma probe identification of the seeds and the levels of exposure to the staff. METHODS: 11 patients received a seed, which was manually placed in an 18 gauge needle with bone wax occluding the tip, and the radiologist introduced it into the breast tissue guided by ultrasound. The seed...... identified. The surgeon removed the seeds together with the breast lesions, and they were identified by the pathologist. There were no unexpected adverse drug reactions. Water bath studies suggest that 1-3 MBq I-125 was sufficient for precise identification, regardless of the presence of conventional Tc-99m...

Design and dosimetry of an eye plaque containing I-125 seeds: An improved dose distribution

International Nuclear Information System (INIS)

Detorie, N.A.; Tkacik, M.F.; Neglia, W.J.; Jenkins, D.; Shadday, J.

1986-01-01

To treat intraocular tumors, a temporarily implanted eye plaque, containing 24 I-125 seeds (3M model 6711), was fabricated from 0.6-mm-thick lead disk with a 1.5-cm diameter. The I-125 seeds were distributed in a particular geometric pattern to average the dose anisotropy of each individual seed. Water phantom measurements made with TLD chips (LiF) and film over the approximate depth range of 1-25 mm were compared with treatment planning computer calculations (Capintec RT-108). Data indicate that the specified geometry produces a dose distribution delivering a tumor dose of 10,000 rad to the tumor apex (7 mm) without exceeding a sclera dose (1 mm) of 40,000 rad. Information regarding fabrication, dosimetry, and radiation safety is presented

The direct biologic effects of radioactive 125I seeds on pancreatic cancer cells PANC-1, at continuous low-dose rates.

Science.gov (United States)

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

2009-08-01

The relative biologic effectiveness of model 6711 125I seeds (Ningbo Junan Pharmaceutical Technology Company,Ningbo, China) and their effects on growth, cell cycle, and apoptosis in human pancreatic cancer cell line PANC-1 were examined in the present study. PANC-1 cells were exposed to the absorbed doses of 1, 2, 4, 6, 8, and 10 Gyeither with 125I seeds (initial dose rate, 2.59 cGy=h) or with 60Co g-ray irradiation (dose rate, 221 cGy=min),respectively. Significantly greater numbers of apoptotic PANC-1 cells were detected following the continuouslow-dose-rate (CLDR) irradiation of 125I seeds, compared with cells irradiated with identical doses of 60Co g-ray. The D(0) for 60Co g-ray and 125I seed irradiation were 2.30 and 1.66, respectively. The survival fraction after 125Iseed irradiation was significantly lower than that of 60Co g-ray, with a relative biologic effectiveness of 1.39.PANC-1 cells were dose dependently arrested in the S-phase by 60Co g-rays and in the G2=M phase by 125I seeds,24 hour after irradiation. CLDR irradiation by 125I seeds was more effective in inducing cell apoptosis in PANC-1cells than acute high-dose-rate 60Co g irradiation. Interestingly, CLDR irradiation by 125I seeds can cause PANC-1cell-cycle arrest at the G2=M phase and induce apoptosis, which may be an important mechanism underlying 125Iseed-induced PANC-1 cell inhibition.

Seed loss through the urinary tract after prostate brachytherapy: examining the role of cystoscopy and urine straining post implant

International Nuclear Information System (INIS)

Stutz, Michael; Petrikas, James; Raslowsky, Michael; Lee, Plato; Gurel, Michelle; Moran, Brian

2003-01-01

This study describes one institution's experience with seed retrieval through the urinary tract and makes recommendations for cystoscopy and urine straining post prostate brachytherapy (PB). 1794 patients from two separate cohorts covering different time periods (early versus late) were analyzed. All patients were preplanned with a modified peripheral loading technique and implanted with preloaded needles ( 125 I or 103 Pd) under ultrasound guidance. A catheter was used to delineate the urethra during the volume study but was not used during the implant. All patients underwent post implant cystoscopy. All patients were instructed to strain their urine for seven days post implant and return any seeds to our center. In our experience, seed loss through the urinary tract is a common event after PB, occurring in 29.7% of patients and was more common in patients from the early cohort, those implanted with 125 I seeds or those patients with prior transurethral resection of the prostate. Average seed loss per case, however, represents only 0.58% of total activity. We continue to recommend routine post implant cystoscopy for seed retrieval and periprocedural management. We no longer recommend that patients strain their urine at home after documenting a low rate of seed loss after discharge

Dose rate constant and energy spectrum of interstitial brachytherapy sources

International Nuclear Information System (INIS)

Chen Zhe; Nath, Ravinder

2001-01-01

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

Study of percutaneous 125I seeds implantation guided by CT in elderly patients of stage I peripheral non-small cell lung cancer

International Nuclear Information System (INIS)

Ke Mingyao; Yong Yazhi; Luo Bingqing; Wu Xuemei; Chen Lingling; Xie Hongqi

2011-01-01

Objective: To evaluate the efficacy, feasibility and safety of CT guided percutaneous 125 I seeds implantation in elderly patients of stage I peripheral non-small cell lung cancer (NSCLC). Methods: Clinical data of 16 elderly peripheral stage I NSCLC patients (10 squamous carcinoma and 6 adenocarcinoma; 13 stage I A and 3 stage I B ) who received radioactive 125 I seeds implantation because of refusal or being unsuited to operation or external radiotherapy were retrospectively analyzed. Prescribed dose was 140 - 160 Gy. Under CT guidance, 125 I seeds were implanted percutaneously into tumors for interstitial radiotherapy according to treatment plan system. Results: Mean number of 125 I seeds each patient received was 21.1. 12 complete response (CR) and 4 partial response (PR) were achieved. Total response rate (CR + PR) was 100%. 100% patients completed 10 to 56 months of follow-up, 15, 13, 8 and 6 patients completed 1-, 2-, 3-and 4-years' follow-up, respectively. The median local progression free time was 14 months. The 1-, 2-, 3-and 4-year overall survival rate were 60%, 54%, 50% and 33%, respectively (median : 14 months). 7 cases died of non-tumor disease and 5 died of metastasis. No severe complications were observed. Conclusions: CT guided 125 I seeds implantation is a safe, reliable and effective radical treatment method for elderly stage I peripheral NSCLC patients, who refuse to or are unsuitable to operation or external radiotherapy. (authors)

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

International Nuclear Information System (INIS)

Moura, Eduardo Santana de

2011-01-01

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

Brachytherapy with 125-Iodine sources: transport and radiation protection

International Nuclear Information System (INIS)

Souza, Carla D.; Zeituni, Carlos A.; Moura, Joao A.; Moura, Eduardo S.; Nagatomi, Helio R.; Feher, Anselmo; Hilario, Katia F.; Rostelato, Maria Elisa C.M.

2009-01-01

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)

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

International Nuclear Information System (INIS)

Mourao, Arnaldo P.; Campos, Tarcisio

2009-01-01

Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for 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)

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

Energy Technology Data Exchange (ETDEWEB)

Zauls, A. Jason; Ashenafi, Michael S. [Department of Radiation Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States); Onicescu, Georgiana [Department of Biostatistics and Epidemiology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States); Clarke, Harry S. [Department of Urology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States); Marshall, David T., E-mail: marshadt@musc.edu [Department of Radiation Oncology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC (United States)

2011-11-15

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% ({Delta}pD90%) between intraoperative and postoperative plans was evaluated. Using GA method, the {Delta}pD90% was -8.1Gy and -12.8Gy for I-125 and Pd-103 implants, respectively. Similarly, the IBCL technique resulted in a {Delta}pD90% of -8.7Gy and -9.8Gy for I-125 and Pd-103 implants, respectively. No statistically significant difference in {Delta}pD90% 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.

Nursing care for patients with local recurrent rectal cancer after CT-guided 125I seed implantation therapy

International Nuclear Information System (INIS)

Yuan Li; Wei Fan; Ren Caifeng; Tu Mingmei; Qian Guixiang

2010-01-01

Objective: To discuss the nursing care strategy for patients with local recurrent rectal cancer who has been treated with CT-guided 125 I seed implantation therapy. Methods: Twenty patients with local recurrent rectal cancer received a series of nursing interventions, including comfort care and pain care. The clinical results were observed and analyzed. Results: The therapy was smoothly accomplished in all patients. The pain was remarkably relived and the anxiety was alleviated. No displacement of implanted 125 I seed occurred. Conclusion: For patients with local recurrent rectal cancer occurred after CT-guided 125 I seed implantation therapy, careful nursing can effectively relieve the pain and anxiety feeling,and the living quality can also be markedly improved. (authors)

Optimum timing for image-based dose evaluation of 125I and 103Pd prostate seed implants

International Nuclear Information System (INIS)

Yue Ning; Chen Zhe; Peschel, Richard; Dicker, Adam P.; Waterman, Frank M.; Nath, Ravinder

1999-01-01

timing for conventional postimplant dose evaluation was identified as the time at which a minimum difference between the conventional DVH and the dynamic model DVH was achieved. The analysis was done on 29 prostate seed implant patients for both 125 I and 103 Pd. The edema magnitude was assumed to be 30%, 40%, 50%, 75%, and 100% of original prostate volume, and the half-life of edema was assumed to be 4, 7, 10, 15, 20, and 25 days. In this study, the original volume of prostate varied from 17 cm 3 to 91 cm 3 , and number of seeds in the implants varied from 57 to 119. Results: The optimum timing was mainly dependent on the half-lives of edema and radionuclides, and varied slightly with edema magnitude, prostate volume, and number of seeds. It can be expressed as a function of edema half-life in the form of C 0 + C 1 exp(-C 2 T e ). However, if the dose evaluation was performed based on the image scans taken too early or too late, the error became larger, as the edema magnitude was larger. By averaging all 29 patients and various edemas, it was found that for 125 I seed implants, if the postimplant dose evaluation is performed based on image scans taken between 5 and 9 weeks, the average error will be less than 5%, with a maximum possible error less than 10% in 80% coverage dose; for 103 Pd seed implants, if the postimplant dose evaluation is performed based on image scans taken between 2 and 4 weeks, the average error will be less than 5%, with a maximum error less than 15% in 80% coverage dose. Because of edema, a conventional preimplant plan also overestimates dose coverage of prostate. On the average, a standard preimplant planning overestimates dose coverage by about 6% for 125 I implants and 14% for 103 Pd implants in our study. Conclusion: Based on the dynamic model, the optimum timing of image scans for postimplant dose evaluation of prostate seed implantation is 7 weeks postimplantation for 125 I implants and about 3 weeks for 103 Pd implants. The time-window for

Sequential evaluation of prostate edema after permanent seed prostate brachytherapy using CT-MRI fusion

International Nuclear Information System (INIS)

Taussky, Daniel; Austen, Lyn; Toi, Ants; Yeung, Ivan; Williams, Theresa; Pearson, Shannon; McLean, Michael; Pond, Gregory; Crook, Juanita

2005-01-01

Purpose: To analyze the extent and time course of prostate edema and its effect on dosimetry after permanent seed prostate brachytherapy. Methods and Materials: Twenty patients scheduled for permanent seed 125 I prostate brachytherapy agreed to a prospective study on postimplant edema. Implants were preplanned using transrectal ultrasonography. Postimplant dosimetry was calculated using computed tomography-magnetic resonance imaging (CT-MRI) fusion on the day of the implant (Day 1) and Days 8 and 30. The prostate was contoured on MRI, and the seeds were located on CT. Factors investigated for an influence on edema were the number of seeds and needles, preimplant prostate volume, transitional zone index (transition zone volume divided by prostate volume), age, and prostate-specific antigen level. Prostate dosimetry was evaluated by the percentage of the prostate volume receiving 100% of the prescribed dose (V 100 ) and percentage of prescribed dose received by 90% of the prostate volume (D 90 ). Results: Prostate edema was maximal on Day 1, with the median prostate volume 31% greater than preimplant transrectal ultrasound volume (range, 0.93-1.72; p 100 on Day 1 was 93.6% (range, 86.0-98.2%) and was 96.3% (range, 85.7-99.5%) on Day 30 (p = 0.079). Patients with a Day 1 V 100 >93% were less affected by edema resolution, showing a median increase in V 100 of 0.67% on Day 30 compared with 2.77% for patients with a V 100 100 >93%)

Ten cases of metastatic cervical cancer with the treatment of permanent 125I seeds interstitial implants

International Nuclear Information System (INIS)

Zhang Hongwei; Li Naibin; Li Qingxin; Liu Huiping; Meng Hui; Chao Dong

2011-01-01

Objective: To investigate the clinical effect of permanent 125 I seeds interstitial implants for metastatic cervical cancer. Methods: Under the guidance of the B-sonography, 125 I seeds were implanted into the eleven cervical lymph nodes of ten patients who had been given tumor resection. The pain relief and tumor size were observed in regular follow-up after one-month treatment. Results: All the patients were followed up for 6-14 months,and the postoperative recovery was good with no complication. One month after the implantation, the pain symptom was alleviated entirely in two nodes and partly in nine nodes. The tumor size shrank in ten nodes while there was no change in one node after one month. Conclusion: Permanent 125 I seeds interstitial implants for metastatic cervical cancer is a safe, minimally invasive and effective treatment. (authors)

Outcomes following iodine-125 prostate brachytherapy with or without neoadjuvant androgen deprivation

International Nuclear Information System (INIS)

Ohashi, Toshio; Yorozu, Atsunori; Saito, Shiro; Momma, Tetsuo; Toya, Kazuhito; Nishiyama, Toru; Yamashita, Shoji; Shiraishi, Yutaka; Shigematsu, Naoyuki

2013-01-01

Purpose: To report the biochemical failure-free survival (BFFS), cause-specific survival (CSS), and overall survival (OS) outcomes of patients treated with iodine-125 (I-125) brachytherapy for clinically localized prostate cancer. Methods and materials: Between 2003 and 2009, I-125 permanent prostate brachytherapy without supplemental external-beam radiotherapy was performed for 663 patients with low-risk and low-tier intermediate-risk (defined as organ-confined disease, PSA <10 ng/mL, and Gleason score 3 + 4 with biopsy positive core rate <33%) prostate cancer. Early in the study period, the preplanning method was used in the first 104 patients, and later the real-time planning method was used. Biochemical failure was determined using the American Society for Therapeutic Radiology Oncology (ASTRO) and Phoenix definitions. Results: The 7-year BFFS rates for the ASTRO and Phoenix definitions were 96.1% and 95.9%, respectively. The corresponding BFFS rates by risk group were 97.6% and 96.7% for low-risk, and 91.8% and 93.6% for low-tier intermediate-risk disease (p = 0.007 and 0.08, respectively). The median times to biochemical failure in those who failed were 29.5 and 43.9 months according to the ASTRO and Phoenix definitions, respectively. The 7-year CSS and OS were 99.1% and 96.4%. There was no significant difference in CSS or OS between the low-risk and low-tier intermediate-risk groups. In multivariate Cox regression analysis, risk group and prostate D90 were independent predictors of BFFS for the ASTRO definition, while only the prostate D90 was significant for the Phoenix definition. Conclusion: I-125 prostate brachytherapy results in excellent 7-year BFFS, CSS, and OS for low-risk and low-tier intermediate-risk prostate cancer

The effect of the radial function on I-125 seeds used for permanent prostate implantation

International Nuclear Information System (INIS)

Pickett, Barby; Pouliot, Jean

2004-01-01

The purpose of this study was to evaluate the integrity of eight commercially-available low-activity Iodine-125 ( 125 I) seeds for their radial function g(r) and its effect on the dose delivered to the adjacent critical structures when used in permanent prostate implants (PPI). Ten previously treated patients were retrospectively used in this comparison. The Amersham Health Oncura seed was used to peripherally design an isodose distribution with urethral and anterior rectal wall sparing. Plan criteria included minimum coverage of 144 Gy to the planning target volume (PTV), ≤ 70% dose to 150% of the PTV volume (V150-PTV), and the quantity of needles ≤ 70% of the size of the PTV, in cc. Upon completion of the Oncura plan, the seed type was changed and the activity was adjusted until the V100-PTV for each of the other 7 seed types matched the V100-PTV defined by the Oncura seed. Computed tomography (CT)-based postimplant dosimetry was used to determine the dose to 40% (D40) of the bulb of the penis (in Gy). Dose-volume histograms (DVH) were used to evaluate the differences to V100 (in %) and D40 (in Gy) of the anterior rectal wall and bulb of the penis, and V100 (in %) of the urethra. The data was tabulated. Radioactive 125 I sources included in this study were 125 I Source 2301 (Best); I-Plant (MedTech), IoGold (Mentor), Oncura (Amersham Health), ProstaSeed (UroCor), SelectSeed (Nucletron), SourceTech (Bard), and Symmetra (UroMed). The sizes of the PTV for the 10 patients ranged from 18.82 cc to 48.99 cc. The Oncura seed was used as the reference seed and all other seed types were normalized to it for data comparison. It was determined that the dose rate constant (xwedge) and anisotropy factor (phi) contribute to the activity needed to achieve comparable V100-PTV doses, but a strong dependence on the radial function g(r) was found to effect the doses to the critical structures studied. Values of g(r) at 4 cm were calculated and the IoGold and SourceTech seeds

Dose characterization of the new Bebig IsoSeed'' (registered) I25.S17 using polymer gel and MRI

Energy Technology Data Exchange (ETDEWEB)

Pantelis, Evaggelos [Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece)]. E-mail: vpantelis@phys.uoa.gr; Baltas, Dimos [Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece): Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach, 63069 Offenbach (Germany); Georgiou, Evaggelos [Medical Physics Department, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece); Karaiskos, Pantelis [Medical Physics Department, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece): Medical Physics Department, Hygeia Hospital, Kiffisias Avenue and 4 Erythrou Stavrou, Marousi, 151 23 Athens (Greece); Lymperopoulou, Georgia [Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece); Papagiannis, Panagiotis [Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece); Sakelliou, Loukas [Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece); Seimenis, Ioannis [Philips Hellas Medical Systems, 44 Kifissias Ave., Maroussi 151 25, Athens (Greece); Stilliaris, Efstathios [Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece): Institute of Accelerating Systems and Applications (IASA), P.O. Box 17214, GR-10024, Athens (Greece)

2006-12-20

A new, molybdenum core, {sup 125}I interstitial brachytherapy seed is marketed by Bebig GmbH (IsoSeed'' (registered) I25.S17) and our group has performed its Dosimetric characterization using Monte Carlo (MC) simulation and Thermoluminescence dosimetry (TLD) as recommended by the AAPM TG-43U1 prior to the clinical implementation of new low-energy seeds. This work presents the results of a supplementary experimental dosimetry study performed using PABIG polymer gel and Magnetic Resonance Imaging (MRI). One new I25.S17 seed and a commercially available, gold core, Bebig IsoSeed'' (registered) I25.S06 {sup 125}I seed were positioned at two different locations in a vial filled with water equivalent, PABIG-polymer gel. The gel with the sources in place was MR scanned in 3D at various time intervals after seed placement using a time efficient, 3D, dual echo Turbo Spin Echo pulse sequence. The consensus dosimetry parameters published in the TG-43U1 for the I25.S06 seed were used to derive the gel response calibration curve for each scanning session. The calibration data were then used to provide dosimetry results for the new I25.S17 seed. Experimental results for the new seed in the form of dose distributions as well as dosimetric quantities in the prevalent TG-43 dosimetric formalism were found to be in close agreement with corresponding MC and TLD results. This finding suggests that the polymer gel-MRI method could at least play a supplementary role to TLD dosimetry in the dose characterization of low energy/low dose rate brachytherapy sources, especially in view of its potential for measurements with a fine spatial resolution down to short distances which are inhibitory to conventional experimental techniques.

Rectourethral fistula following LDR brachytherapy.

Science.gov (United States)

Borchers, Holger; Pinkawa, Michael; Donner, Andreas; Wolter, Timm P; Pallua, Norbert; Eble, Michael J; Jakse, Gerhard

2009-01-01

Modern LDR brachytherapy has drastically reduced rectal toxicity and decreased the occurrence of rectourethral fistulas to <0.5% of patients. Therefore, symptoms of late-onset sequelae are often ignored initially. These fistulas cause severe patient morbidity and require interdisciplinary treatment. We report on the occurrence and management of a rectourethral fistula which occurred 4 years after (125)I seed implantation. Copyright 2009 S. Karger AG, Basel.

Clinical Study on Using 125I Seeds Articles Combined with Biliary Stent Implantation in the Treatment of Malignant Obstructive Jaundice.

Science.gov (United States)

Wang, Tao; Liu, Sheng; Zheng, Yan-Bo; Song, Xue-Peng; Sun, Bo-Lin; Jiang, Wen-Jin; Wang, Li-Gang

2017-08-01

Aim: To study the feasibility and curative effect of 125 I seeds articles combined with biliary stent implantation in the treatment of malignant obstructive jaundice. Patients and Methods: Fifty patients with malignant obstructive jaundice were included. Twenty-four were treated by biliary stent implantation combined with intraluminal brachytherapy by 125 I seeds articles as the experimental group, while the remaining 26 were treated by biliary stent implantation only as the control group. The goal of this study was to evaluate total bilirubin, direct bilirubin and tumor markers (cancer antigen (CA)-199, CA-242 and carcinoembryonic antigen (CEA)), as well as biliary stent patency status and survival time before and after surgery. Results: Jaundice improved greatly in both groups. The decreases of CA-199 and CA-242 had statistical significance (p=0.003 and p=0.004) in the experimental group. The ratio of biliary stent patency was 83.3% (20/24) in the experimental group and 57.7% (15/26) in the control group (p=0.048). The biliary stent patency time in the experimental group was 1~15.5 (mean=9.84) months. The biliary stent patency time in the control group was 0.8~9 (mean=5.57) months, which was statistically significant (p=0.018). The median survival time was 10.2 months in the experimental group, while 5.4 months in control group (pjaundice possibly by inhibiting the proliferation of vascular endothelial cells and the growth of tumor. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

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)

SU-F-I-19: MRI Positive Contrast Visualization of Prostate Brachytherapy Seeds Using An Integrated Laplacian-Based Phase Processing

Energy Technology Data Exchange (ETDEWEB)

Soliman, A; Safigholi, H [Sunnybrook Research Institute, Toronto, ON (Canada); Sunnybrook Health Sciences Center, Toronto, ON (Canada); Nosrati, R [Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ryerson University, Toronto, ON (Canada); Owrangi, A; Morton, G [Sunnybrook Health Sciences Center, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada); Song, W [Sunnybrook Research Institute, Toronto, ON (Canada); Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ryerson University, Toronto, ON (Canada); University of Toronto, Toronto, ON (Canada)

2016-06-15

Purpose: To propose a new method that provides a positive contrast visualization of the prostate brachytherapy seeds using the phase information from MR images. Additionally, the feasibility of using the processed phase information to distinguish seeds from calcifications is explored. Methods: A gel phantom was constructed using 2% agar dissolved in 1 L of distilled water. Contrast agents were added to adjust the relaxation times. Four iodine-125 (Eckert & Ziegler SML86999) dummy seeds were placed at different orientations with respect to the main magnetic field (B0). Calcifications were obtained from a sheep femur cortical bone due to its close similarity to human bone tissue composition. Five samples of calcifications were shaped into different dimensions with lengths ranging between 1.2 – 6.1 mm.MR imaging was performed on a 3T Philips Achieva using an 8-channel head coil. Eight images were acquired at eight echo-times using a multi-gradient echo sequence. Spatial resolution was 0.7 × 0.7 × 2 mm, TR/TE/dTE = 20.0/2.3/2.3 ms and BW = 541 Hz/pixel. Complex images were acquired and fed into a two-step processing pipeline: the first includes phase unwrapping and background phase removal using Laplacian operator (Wei et al. 2013). The second step applies a specific phase mask on the resulting tissue phase from the first step to provide the desired positive contrast of the seeds and to, potentially, differentiate them from the calcifications. Results: The phase-processing was performed in less than 30 seconds. The proposed method has successfully resulted in a positive contrast of the brachytherapy seeds. Additionally, the final processed phase image showed difference between the appearance of seeds and calcifications. However, the shape of the seeds was slightly distorted compared to the original dimensions. Conclusion: It is feasible to provide a positive contrast of the seeds from MR images using Laplacian operator-based phase processing.

Autoradiography for iodine-125 seeds

International Nuclear Information System (INIS)

Alberti, W.; Divoux, S.; Pothmann, B.; Tabor, P.; Hermann, K.P.; Harder, D.

1993-01-01

To study the interior design of model 6702 and 6711 iodine-125 seeds, contact autoradiographs were performed using mammography film. Improved resolution was obtained using a pin-hole camera with a hole of 0.1 mm x 0.1 mm. With these techniques, qualitative determination of the relative activity distribution within each seed was possible. The number of the activated resin spheres and the positions of the centers of these spheres can be exactly determined. A model calculation shows that variations in the arrangement of the activated spheres within a seed have a moderate influence on the dose distribution at source distances below 10 mm. Knowing the exact source configuration may be useful when comparing dose calculations with measured data for model 6702 125 I seeds which are currently employed in ophthalmic plaque and implant therapy of other tumors. 16 refs., 5 figs., 2 tabs

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.

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

Science.gov (United States)

Mason, J; Al-Qaisieh, B; Bownes, P; Henry, A; Thwaites, D

2013-03-01

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. 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. 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 (1.8%). ISA causes the delivered dose

Radiation complications and tumor control after 125I plaque brachytherapy for ocular melanoma

International Nuclear Information System (INIS)

Jensen, Ashley W.; Petersen, Ivy A.; Kline, Robert W.; Stafford, Scott L.; Schomberg, Paula J.; Robertson, Dennis M.

2005-01-01

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

Evolution of different reaction methods resulting in the formation of AgI125 for use in brachytherapy sources

International Nuclear Information System (INIS)

Souza, C.D.; Peleias Jr, F.S.; Rostelato, M.E.C.M.; Zeituni, C.A.; Benega, M.A.G.; Tiezzi, R.; Mattos, F.R.; Rodrigues, B.T.; Oliveira, T.B.; Feher, A.; Moura, J.A.; Costa, O.L.

2014-01-01

Prostate cancer represents about 10% of all cases of cancer in the world. Brachytherapy has been extensively used in the early and intermediate stages of the illness. The radiotherapy method reduces the damage probability to surrounding healthy tissues. The present study compares several deposition methods of iodine-125 on silver substrate (seed core), in order to choose the most suitable one to be implemented at IPEN. Four methods were selected: method 1 (assay based on electrodeposition) which presented efficiency of 65.16%; method 2 (assay based on chemical reactions, developed by David Kubiatowicz) which presented efficiency of 70.80%; method 3 (chemical reaction based on the methodology developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80%; new method developed by IPEN with 90.5% efficiency. Based on the results, the new method is the suggested one to be implemented. (authors)

Impact of target area selection in 125 Iodine seed brachytherapy on locoregional recurrence in patients with non-small cell lung cancer.

Science.gov (United States)

Yan, Wei-Liang; Lv, Jin-Shuang; Guan, Zhi-Yu; Wang, Li-Yang; Yang, Jing-Kui; Liang, Ji-Xiang

2017-05-01

Computed tomography (CT)-guided percutaneous implantation of 125 Iodine radioactive seeds requires the precise arrangement of seeds by tumor shape. We tested whether selecting target areas, including subclinical areas around tumors, can influence locoregional recurrence in patients with non-small cell lung cancer (NSCLC). We divided 82 patients with NSCLC into two groups. Target areas in group 1 (n = 40) were defined along tumor margins based on lung-window CT. Target areas in group 2 (n = 42) were extended by 0.5 cm in all dimensions outside tumor margins. Preoperative plans for both groups were based on a treatment plan system, which guided 125 I seed implantation. Six months later, patients underwent chest CT to evaluate treatment efficacy (per Response Evaluation Criteria in Solid Tumors version 1). We compared locoregional recurrences between the groups after a year of follow-up. We then used the treatment plan system to extend target areas for group 1 patients by 0.5 cm (defined as group 3 data) and compared these hypothetical group 3 planned seeds with the actual seed numbers used in group 1 patients. All patients successfully underwent implantation; none died during the follow-up period. Recurrence was significantly lower in group 2 than in group 1 ( P  area for 125 I seeds can decrease recurrence risk by eradicating cancerous lymph-duct blockades within the extended areas. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

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

International Nuclear Information System (INIS)

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

2002-01-01

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 (105 125 I and 15 103 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)

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)

A prospective analysis of long-term quality of life after permanent I-125 brachytherapy for localised prostate cancer

International Nuclear Information System (INIS)

Ash, Dan; Bottomley, David; Al-Qaisieh, Bashar; Carey, Brendan; Gould, Kath; Henry, Ann

2007-01-01

Background and purpose: To prospectively evaluate long-term urinary, bowel and sexual function after I-125 brachytherapy for localised prostate cancer using patient administered validated Quality of Life (QoL) instruments. Materials and methods: Between March 1995 and March 2004, 673 men underwent brachytherapy and recorded urinary symptoms prospectively using the International Prostate Symptom Score (IPSS). In addition, in a subgroup of 116 patients, the Expanded Prostate Cancer Index Composite (EPIC) was used to record QoL information on urinary, bowel and sexual function before treatment and at regular time intervals for at least two years. Results: Initially, there was a sharp rise in urinary symptoms which was most marked within the first three months. Scores then resolved slowly and returned to within one or two units of pre-treatment level at one year. Subsequently, there was no significant deterioration in urinary symptoms up to nine years following brachytherapy. Few had significant bowel symptoms. Sexual function deteriorated initially and then improved but failed to return to pre-treatment levels by two years. Patients requiring neo-adjuvant hormones experienced significantly more dysfunction. Conclusions: After an initial period of mild to moderate urinary symptoms prostate brachytherapy is well tolerated with relatively little deterioration in long-term quality of life. Long-term reduction in sexual function may be seen particularly in those requiring hormones

Epoxy resins used to seal brachytherapy seed

International Nuclear Information System (INIS)

Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos

2013-01-01

Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

Analysis of prostate-specific antigen bounce after I125 permanent seed implant for localised prostate cancer

International Nuclear Information System (INIS)

Mitchell, Darren M.; Swindell, Ric; Elliott, Tony; Wylie, James P.; Taylor, Cathy M.; Logue, John P.

2008-01-01

Background and purpose: To report on the incidence of benign prostate-specific antigen bounce following permanent I 125 prostate brachytherapy, to describe the associations in our population and review the relationship of bounce to subsequent biochemical failure. Materials and methods: From February 2000 to May 2005, 374 patients with localised prostate cancer were treated with I 125 permanent prostate brachytherapy at a single institution. A prospectively collected database was used to identify cases of prostate-specific antigen (PSA) bounce, defined as a rise of ≥0.2 ng/ml above an initial PSA nadir with subsequent decline to or below that nadir without treatment. The patients who received neo-adjuvant or adjuvant hormone manipulation were excluded. Biochemical failure was determined using the both the ASTRO consensus definition and Phoenix (nadir +2 ng/mL) definition. Results: Two hundred and five patients were identified with a median follow-up of 45 months (24-85). PSA bounce was noted in 79 (37%) men, occurring at a median of 14.8 months (1.7-40.6) following implant. The median peak PSA was 1.8 ng/ml (0.4-7.4) with a bounce magnitude of 0.91 ng/ml (0.2-5.8). When pre- and post-implant factors were assessed for association to bounce, only younger age was statistically significant (p = 0.002). The threshold for biochemical failure as defined by the ASTRO consensus definition (1997) was met in 4 (5%) patients after experiencing bounce as opposed to 19 (15%) non-bounce patients (p = 0.01). The threshold for Phoenix (nadir +2 ng/mL) was met in 6 (7.5%) patients following bounce versus 22 (17%) of non-bounce patients (p = 0.003). Both definitions are prone to false positive calls during bounce. Median PSA velocity during the bounce was 0.08 ng/mL/month (0.02-0.98) and was statistically significantly lower than the median velocity prior to the Phoenix biochemical failure at 0.28 ng/mL/month (0.07-2.04) (p = 0.0005). Conclusion: PSA bounce is a common finding in

Monte Carlo study of LDR seed dosimetry with an application in a clinical brachytherapy breast implant.

Science.gov (United States)

Furstoss, C; Reniers, B; Bertrand, M J; Poon, E; Carrier, J-F; Keller, B M; Pignol, J P; Beaulieu, L; Verhaegen, F

2009-05-01

A Monte Carlo (MC) study was carried out to evaluate the effects of the interseed attenuation and the tissue composition for two models of 125I low dose rate (LDR) brachytherapy seeds (Medi-Physics 6711, IBt InterSource) in a permanent breast implant. The effect of the tissue composition was investigated because the breast localization presents heterogeneities such as glandular and adipose tissue surrounded by air, lungs, and ribs. The absolute MC dose calculations were benchmarked by comparison to the absolute dose obtained from experimental results. Before modeling a clinical case of an implant in heterogeneous breast, the effects of the tissue composition and the interseed attenuation were studied in homogeneous phantoms. To investigate the tissue composition effect, the dose along the transverse axis of the two seed models were calculated and compared in different materials. For each seed model, three seeds sharing the same transverse axis were simulated to evaluate the interseed effect in water as a function of the distance from the seed. A clinical study of a permanent breast 125I implant for a single patient was carried out using four dose calculation techniques: (1) A TG-43 based calculation, (2) a full MC simulation with realistic tissues and seed models, (3) a MC simulation in water and modeled seeds, and (4) a MC simulation without modeling the seed geometry but with realistic tissues. In the latter, a phase space file corresponding to the particles emitted from the external surface of the seed is used at each seed location. The results were compared by calculating the relevant clinical metrics V85, V100, and V200 for this kind of treatment in the target. D90 and D50 were also determined to evaluate the differences in dose and compare the results to the studies published for permanent prostate seed implants in literature. The experimental results are in agreement with the MC absolute doses (within 5% for EBT Gafchromic film and within 7% for TLD-100

Medical physics aspects of ophthalmic brachytherapy

International Nuclear Information System (INIS)

Sharma, S.D.; Shanta, A.; Palani Selvam, T.; Tripathi, U.B.; Bhatt, B.C.

2004-11-01

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 90 Sr/ 90 Y 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 125 I seed sources by the Radiopharmaceuticals Division, BARC. This report presents a brief description on the clinical, dosimetry and radiation safety aspects of 90 Sr/ 90 Y and 106 Ru/ 106 Rh beta ray and 125 I 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 90 Sr/ 90 Y and 106 Ru/ 106 Rh beta and 125 I gamma ophthalmic plaques are given in Section II and Section III, respectively. Section IV contains the single seed dosimetry data of BARC OcuProsta 125 I seed as well as dosimetry data of typical eye plaques loaded with BARC OcuProsta 125 I 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)

Results of a dummy run of postimplant dosimetry between multi-institutional centers in prostate brachytherapy with 125I seeds

International Nuclear Information System (INIS)

Aoki, Manabu; Yorozu, Atsunori; Dokiya, Takushi

2009-01-01

The purpose of this study was to determine the reproducibility and precision of postimplant dosimetry following 125 I prostate brachytherapy (PB) and to evaluate the effects of learning and experience in CT-based postimplant dosimetry. One-month postimplant CT data from two patients who underwent PB alone or combined therapy (PB+external beam radiation therapy (EBRT)) were sent to 28 institutions for postimplant dosimetry and analyzed in 2006 (study 1). Similarly, 1-month postimplant CT data from two other patients were also analyzed in 2008 (study 2; 23 institutions). For both modalities in studies 1 and 2, the variance of the difference between CT-based D90 at each institution and CT/MRI fusion-based D90 was estimated. In monotherapy, F test and Mann-Whitney U test revealed no significant difference in the variance in studies 1 and 2 (P=0.72, 0.46). In combined therapy, the variance significantly converged in study 2 compared with study 1 (P<0.05). Even in the two studies, however, the difference between the median CT-based D90 and fusion-based D90 was at least 20-30 Gy. Marked interobserver variability was seen in the prostate volume and D90 with CT alone. The precision of postimplant dosimetry based on CT alone was revealed to be limited. (author)

Clinical analysis of 125I seed implants in worst-casts of the malignant tumors after radiography and chemotherapy

International Nuclear Information System (INIS)

Chen Zhijun; Tu Xinhua; Zhou Aiqing; Wang Xueqin

2006-01-01

Objective: To investigate the curative effect and side reaction after 125 I seed implanted among tissue were treated the malignant neoplasm by radiography and chemotherapy. Methods: Retrospective analysis the cancerous sufferer after the failure of radiography and chemotherapy, percutaneous puncture or intraoperative under gaze forward 125 I seed were implanted the bed of the tumour forever. Follow-up blood routine examination, symptom, sign, using USG or CT observe the change of the tumour and the distribution of the particles etc. Results: In 3 cases, treat 2 cases, tumour reduced obviously, symptoms improved obviously, the face of the ulcer cured, the particles did not shift, hemogram did not decline obviously. Conclusion: 125 I seed among the tissue implanted forever for the unsuccessful case after radiography and chemotherapy supply a new therapeutic methods. In the neat future curative effect is exactly, toxic reaction is small, which can remedy the deficiency of the treatment for radiography and chemotherapy. (authors)

{sup 125}I brachytherapy in younger prostate cancer patients. Outcomes in low- and intermediate-risk disease

Energy Technology Data Exchange (ETDEWEB)

Kindts, Isabelle; Stellamans, Karin; Lambrecht, Antoon [AZ Groeninge Hospital, Department of Radiation Oncology, Kortrijk (Belgium); Billiet, Ignace [AZ Groeninge Hospital, Department of Urology, Kortrijk (Belgium); Pottel, Hans [Catholic University Leuven Kulak, Biostatistics, Faculty of Medicine, Kortrijk (Belgium)

2017-09-15

To evaluate local recurrence in younger men treated with low-dose-rate (LDR) {sup 125}I brachytherapy (BT) for localized prostate cancer. A total of 192 patients (≤65-years-old) were treated with LDR {sup 125}I-BT ± hormone therapy. Local failure was defined as any prostate-specific antigen (PSA) rise leading to salvage treatment or biochemical failure according to the Phoenix definition. A bounce was defined as a rise in the nadir of ≥0.2 ng/mL followed by spontaneous return. Proportions were compared using Fisher's exact tests; continuous variables using the unpaired t-test or its non-parametric equivalent. Cox proportional hazards models were applied for multivariable survival analysis. Median follow-up was 66 months. The 5-year local recurrence-free survival was 96.1%. Biopsy-proven local recurrence developed in 13 patients, 4 had a Phoenix-defined recurrence at the last follow-up. Androgen deprivation therapy was started in 1 patient without proven recurrence. Univariable risk factors for local recurrence were: at least 50% positive biopsies, intermediate risk, treatment with neoadjuvant hormone therapy, low preimplantation volume receiving 100% of the prescribed dose, and no bounce development. Hormone-naive patients not attaining a PSA value <0.5 ng/mL during follow-up also had a higher risk of local recurrences. Cox regression demonstrated that the variables ''at least 50% positive biopsies'' and ''bounce'' significantly impacted local failure (hazard ratio, HR 1.02 and 11.59, respectively). A bounce developed in 70 patients (36%). Younger patients and those treated with a lower activity per volume had a higher chance of developing a bounce in the Cox model (HR 0.99 and 0.04, respectively). For younger men, LDR BT is a valid primary curative treatment option in low-risk and is to consider in intermediate-risk localized prostate cancer. (orig.) [German] Bestimmung der Lokalrezidivrate bei juengeren Patienten

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

Energy Technology Data Exchange (ETDEWEB)

Morrison, H; Menon, G; Sloboda, R [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

2014-08-15

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.

Self-expandable medical memorial metallic stent with 125I seeds for the treatment of esophageal carcinoma: a retrospective analysis

International Nuclear Information System (INIS)

Zhang Shuo; Lu Bin

2011-01-01

Objective: To discuss the curative effect and safety of the implantation of self-expandable medical memorial metallic stent with 125 I seeds for the treatment of advanced esophageal carcinomas. Methods: Implantation of self-expandable medical memorial metallic stent with 125 I seeds was performed in 32 patients with advanced esophageal canner. The clinical data were retrospectively analyzed. The technical success rate, the operation time, the immediate and mid-term effectiveness, the survival time, the complications, the body weight, the blood picture, the immune indexes, the average hospitalization days and hospitalization expenses were analyzed. Results: The average operation time was (18±5) minutes. Successful stent implantation was achieved in all 32 patients (100%). No 125 I seeds fell off during the procedure. The remission rate of dysphagia was 100%. Esophageal restenosis occurred in four patients, and displacement of the stent was seed in one patient. One month after the treatment, 90% of patients had a Karnofsky performance score over 60. The mean survival time was (8.7±6.6) months. The average hospitalization time was (7.8±3.7) days and the mean hospitalization cost was (12±3) thousand Chinese Yuan. Conclusion: For the treatment of esophageal carcinomas, the implantation of self-expandable medical memorial metallic stent with 125 I seeds is safe, effective and simple. This treatment can markedly improve the symptom of dysphagia and significantly prolong the patient's survival time. (authors)

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

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Ding, William, E-mail: billyding888@gmail.com [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, California (United States); Lee, John [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, California (United States); Chamberlain, David [Department of Radiation Oncology, St. Mary' s Regional Medical Center, Reno, Nevada (United States); Cunningham, James [Carson Urology, Carson City, Nevada (United States); Yang Lixi [Department of Radiation Oncology, California Pacific Medical Center, San Francisco, California (United States); Tay, Jonathan [Department of Radiation Oncology, St. Mary' s Regional Medical Center, Reno, Nevada (United States)

2012-11-15

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-naieve 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

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)

Ding, William; Lee, John; Chamberlain, David; Cunningham, James; Yang Lixi; Tay, Jonathan

2012-01-01

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

A traceability establishment for the 125I IsoSeed I25.S06 source from Bebig at the hospital level; Propuesta de obtencion de trazabilidad a nivel hospitalario para la fuente de 125I IsoSeed I25.S06 de Bebig

Energy Technology Data Exchange (ETDEWEB)

Perez-Calatayud, J.; Bejar, M.J.; Lliso, F.; Colmenares, R.; Fernandez, J.; Andrassy, M.; Carmona, V.; Ferrer, N.; Vivanco, J.

2010-07-01

The purpose of this work has been on one side to solve the traceability problem in hospitals for the I25.S06 seed users, already solved for other seeds, and on the other to design a holder in order to allow the measurement of the reference air-kerma rate for the strand by means of a well-type ionization chamber, widely used in brachytherapy in hospitals. At a joint calibration-measurement session of the involved institutions the following steps were performed: calibration of the HDR 1000 and SourceCheck detectors with a standard source from the Physikalisch-Technische Bundesanstalt (PTB); reference air-kerma rate measurements for the 5 seeds strand provided by Bebig with the SourceCheck detector and with the HDR 1000 detector and the new insert holder by SIHO (Spain); separation of the stranded seeds by the specialist from Bebig who dissolved the plastic; reference air-kerma rate measurement of each of the seeds of the strand with one of the of HDR 1000 detectors previously calibrated. We present the calibration factors obtained and the analysis of the uncertainties associated with the process. (Author).

CT-guided interstitial 125I seed implantation for intractable pelvic recurrence of rectal carcinomas

International Nuclear Information System (INIS)

Lin Zhenwen; Chu Hong; Kong Jian; Dou Yongchong

2011-01-01

Objective: To evaluate the therapeutic effect and safety of CT-guided interstitial 125 I seed implantation in treating intractable pelvic recurrence of rectal carcinomas. Methods: During the period from April 2010 to September 2010 CT-guided interstitial 125 I seed implantation was carried out in 11 patients with pelvic recurrence of rectal carcinoma which developed after the patients had received comprehensive treatments such as surgical resection, chemotherapy and/or radiotherapy. The clinical data were retrospectively analyzed. The clinical symptoms, the tumor size and the quality of life (QOL) before the treatment and at two and six months after the treatment were recorded, and the complications were observed. The results were compared. All the patients were followed up for six months. Results: At two and six months after the treatment, the improvement rate of the clinical symptoms was 100.0% (11/11) and 90.9% (10/11) respectively, while the effective reduction of the tumor size was 90.9% (10/11) and 81.8% (9/11) respectively. At two and six months after the treatment the QOL score was (56.0±3.66) and (54.4±5.41) respectively, both of which were higher than the QOL score determined before the treatment (42.5±6.93), the difference between them was statistically significant (P 125 I seed implantation has satisfactory short-term effect. This treatment is also quite safe and effective for patients who are unbearable to external radiation therapy due to the tissue dose restriction. (authors)

The biological effect of 125I seed continuous low dose rate irradiation in CL187 cells

Directory of Open Access Journals (Sweden)

Zhuang Hong-Qing

2009-01-01

Full Text Available Abstract Background To investigate the effectiveness and mechanism of 125I seed continuous low-dose-rate irradiation on colonic cell line CL187 in vitro. Methods The CL187 cell line was exposed to radiation of 60Coγ ray at high dose rate of 2 Gy/min and 125I seed at low dose rate of 2.77 cGy/h. Radiation responses to different doses and dose rates were evaluated by colony-forming assay. Under 125I seed low dose rate irradiation, a total of 12 culture dishes were randomly divided into 4 groups: Control group, and 2, 5, and 10 Gy irradiation groups. At 48 h after irradiation, apoptosis was detected by Annexin and Propidium iodide (PI staining. Cell cycle arrests were detected by PI staining. In order to investigate the influence of low dose rate irradiation on the MAPK signal transduction, the expression changes of epidermal growth factor receptor (EGFR and Raf under continuous low dose rate irradiation (CLDR and/or EGFR monoclonal antibodies were determined by indirect immunofluorescence. Results The relative biological effect (RBE for 125I seeds compared with 60Co γ ray was 1.41. Apoptosis rates of CL187 cancer cells were 13.74% ± 1.63%, 32.58% ± 3.61%, and 46.27% ± 3.82% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 1.67% ± 0.19%. G2/M cell cycle arrests of CL187 cancer cells were 42.59% ± 3.21%, 59.84% ± 4.96%, and 34.61% ± 2.79% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 26.44% ± 2.53%. P 2/M cell cycle arrest. After low dose rate irradiation, EGFR and Raf expression increased, but when EGFR was blocked by a monoclonal antibody, EGFR and Raf expression did not change. Conclusion 125I seeds resulted in more effective inhibition than 60Co γ ray high dose rate irradiation in CL187 cells. Apoptosis following G2/M cell cycle arrest was the main mechanism of cell-killing effects under low dose rate irradiation. CLDR could

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

Energy Technology Data Exchange (ETDEWEB)

Moura, Eduardo Santana de

2011-07-01

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

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

Science.gov (United States)

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

2014-09-21

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

The contamination on farm products from 125I

International Nuclear Information System (INIS)

Zhao Wenhu; Xu Shiming; Hou Lanxin

1990-02-01

The 125 I contamination on 15 farm products have been investigated. The effects of 12 farm crops (wheat, bean, eggplants and other vegetables) contaminated by 125 I during the growing stage on their fruits and seeds have been studied. The results show that the 125 I radioactive substance is mainly concentrated on the fruit surface, and the radioactivity rapidly decreased towards its kernel. The fruits and seeds would not be contaminated when plants were contaminated in the seedling stage

Comparison of CT- and radiograph-based post-implant dosimetry for transperineal 125I prostate brachytherapy using single seeds and a commercial treatment-planning software

International Nuclear Information System (INIS)

Siebert, F.A.; Kohr, P.; Kovacs, G.

2006-01-01

Background and purpose: the objective of this investigation was a direct comparison of the dosimetry of CT-based and radiograph-based postplanning procedures for seed implants. Patients and methods: CT- and radiograph-based postplans were carried out for eight iodine-125 ( 125 I) seed implant patients with a commercial treatment-planning system (TPS). To assess a direct comparison of the dosimetric indices (D90, V100, V400), the radiograph-based seed coordinates were transformed to the coordinate system of the CT postplan. Afterwards, the CT-based seed positions were replaced by the radiograph-based coordinates in the TPS and the dose distribution was recalculated. Results: the computations demonstrated that the radiograph-based dosimetric values for the prostate (D p 90, V p 100, and V p 400) were on average lower than the values of the CT postplan. Normalized to the CT postplan the following mean values were found: D p 90: 90.6% (standard deviation [SD]: 9.0%), V p 100: 86.1% (SD: 14.7%), and V p 400: 79.4% (SD: 14.4%). For three out of the eight patients the D p 90 decreased to 90% of the initial CT postplan values. The reason for this dosimetric difference is supposed to be evoked by an error of the reconstruction software used. It was detected that the TPS algorithm assigned some sources to wrong coordinates, partly out of the prostate gland. Conclusion: the radiograph-based postplanning technique of the investigated TPS should only be used in combination with CT postplanning. Furthermore, complex testing procedures of reconstruction algorithms are recommended to minimize calculation errors. (orig.)

A magazine for the implantation of I-125 seeds in interstitial therapy of cerebral tumors

International Nuclear Information System (INIS)

Bockermann, V.; Dieckmann, G.; Lott, H.

1988-01-01

A compact magazine has been developed allowing a quick and easy implantation of I-125 seeds in interstitial therapy of intracranial tumors. The magazine is made of steel and has the shape of a right parallelepiped. One seed can be put each time into a movable insert. The magazine is connected to a normal application canula. It is easy to handle and contributes much to radioprotection. (orig.) [de

The effect of interstitial 125I seeds implantation on intestinal wall: a pathological observation in experimental dogs

International Nuclear Information System (INIS)

Ning Houfa; Zhang Fenglian; Shen An; Cao Guiwen; Cui Xinjiang

2010-01-01

Objective: To observe the radiation injury of the bowel wall due to the implantation of interstitial 125 I seeds in experimental dogs. Methods: A total of 12 healthy male dogs were randomly and equally divided into 3 experimental groups and 1 control group, with 3 dogs in each group.In the experimental groups, two 125 I seeds with the active radiation dose of 0.8mCi were symmetrically implanted under the serous membrane of the dog's small intestinal wall. The dogs were fed for 14 days (group A), for one month (group B) and for two months (group C) respectively when the animals were scheduled to be sacrificed. The dogs' general condition was observed till they were sacrificed. The seed-implanting intestinal segments were then removed and dyed with HE staining method for electronic microscopic exam. The histopathologic findings were recorded and the results were compared between four groups. Results: No obvious histopathological changes were found in the dog's bowel wall 14 days after the implantation. One month after the procedure cellular injury was observed under electronic microscope, and two months after the operation partial fibrosis of the intestinal wall appeared but no ulceration or perforation occurred. Conclusion: The implantation of 125 I seeds can cause reversible cellular injuries of the intestinal wall in experimental dogs, the degree of the damage reaches its peak at one month after the implant when the partial fibrosis of bowel wall becomes evident. However, the seeds do not cause any serious complications, such as ulceration or perforation. (authors)

Effects of gold and silver backings on the dose rate around an 125I seed

International Nuclear Information System (INIS)

Cygler, J.; Szanto, J.; Soubra, M.; Rogers, D.W.

1990-01-01

Measurements of the effect of either gold or silver backing on the dose rate around an 125I seed were performed using a Therados RFA7 dosimetry system and a small diode detector which was 2.5 mm in diameter and 0.06 mm thick. It was found that the presence of the gold or silver backing modifies the diode response on the side of the 125I seed away from the backing. The effect depends on the backing material and the distance from the seed. There is a small increase close to the gold backing but a decrease further away. This decrease at distances greater than 10 mm from the seed is uniformly 10%, the same as found when the seed is backed by air. There is an increase of up to 25% observed with silver backing the seed and this increase remains significant more than 30 mm from the seed. When the response increases, the results are hard to interpret quantitatively because of variations in the diode response per unit dose with photon energy and extreme sensitivity to geometric changes. Nonetheless, except for the increase at close distances with the gold, the results are in agreement with EGS4 Monte Carlo photon transport simulations which are for a simplified geometry and account for x-ray fluorescence from the K-shell. Furthermore, the increase in the gold-backed case is qualitatively explained by Williamson's Monte Carlo calculations which take into account the L-shell fluorescent x-rays from gold

Bystander effects of exposure to low-dose-rate 125I seeds on human lung cancers cells in vitro

International Nuclear Information System (INIS)

Jia Rongfei; Chen Honghong; Yu Lei; Zhao Meijia; Shao Chunlin; Cheng Wenying

2007-01-01

The bystander effects induced by continuous low-dose-rate (LDR) 125 I seeds radiation on damage of human lung cancer cells were investigated. Human adenocarcinoma cell line A549 and human small cell lung cancer cell line NCI-H446, which have different sensitivities to high-dose rate (HDR) external irradiation, were exposed directly to 125 I seeds in vitro and co-cultured with unirradiated cells for 24 h. Using cytokinesis-blocking micronucleus method and γ H2AX fluorescence immunoassay, bystander effects induced by 2Gy and 4Gy 125 I seed irradiation on micronucleus formation and DNA double-strand breaks (DSBs) of human lung cancer cells were detected and evaluated. The results showed that irradiation with 125 I seeds can induce medium-mediated bystander effects in A549 cells and NCI-H446 cells, exhibiting that both micronuclei formation and γ H2AX focus formation in bystander cells were increased significantly compared with non-irradiated cells. The extent of DNA damage induced by bystander effects was correlated with accumulated radiation dose and radiosensitive of tumor cells. NCI-H446 cells that were sensitive to HDR γ irradiation were more sensitive to continuous LDR irradiation and bystander effects than A549. However, a comparison between the bystander effects and direct effects elicits the intensity of bystander responses of A549 cells was higher than that of NCI-H446 cells. A dose-related reduction in bystander responses was observed both in A549 cells and NCI-H446 cells, suggesting that the signaling factors involved in the bystander signaling pathways may decrease with the increase of cell damages. (authors)

Salvage stereotactic body radiotherapy for locally recurrent non-small cell lung cancer after sublobar resection and I125 vicryl mesh brachytherapy

Directory of Open Access Journals (Sweden)

Beant Singh Gill

2015-05-01

Full Text Available Purpose: Locally-recurrent non-small cell lung cancer (LR-NSCLC remains challenging treat, particularly in patients having received prior radiotherapy. Heterogeneous populations and varied treatment intent in existing literature result in significant limitations in evaluating efficacy of lung re-irradiation. In order to better establish the impact of re-irradiation in patients with LR-NSCLC following high-dose radiotherapy, we report outcomes for patients treated with prior sublobar resection and brachytherapy that subsequently underwent stereotactic body radiotherapy (SBRT.Methods: A retrospective review of patients initially treated with sublobar resection and I125 vicryl mesh brachytherapy, who later developed LR-NSCLC along the suture line, was performed. Patients received salvage SBRT with curative intent. Dose and fractionation was based on tumor location and size, with a median prescription dose of 48 Gy in 4 fractions (range 20-60 Gy in 1-4 fractions.Results: Thirteen consecutive patients were identified with median follow-up of 2.1 years (range 0.7-5.6 years. Two in-field local failures occurred at 7.5 and 11.1 months, resulting in 2-year local control of 83.9% (95% CI 63.5-100.0%. Two-year disease-free survival and overall survival estimates were 38.5% (95% CI 0.0-65.0% and 65.8% (95% CI, 38.2-93.4%. Four patients (31% remained disease-free at last follow-up. All but one patient who experienced disease recurrence developed isolated or synchronous distant metastases. Only one patient (7.7% developed grade ≥3 toxicity, consisting of grade 3 esophageal stricture following a centrally located recurrence previously treated with radiofrequency ablation.Conclusion: Despite high local radiation doses delivered to lung parenchyma previously with I125 brachytherapy, re-irradiation with SBRT for LR-NSCLC results in excellent local control with limited morbidity, allowing for potential disease cure in a subset of patients.

Study of two different radioactive sources for prostate brachytherapy treatment

International Nuclear Information System (INIS)

Pereira Neves, Lucio; Perini, Ana Paula; Souza Santos, William de; Caldas, Linda V.E.; Belinato, Walmir

2015-01-01

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

Study of two different radioactive sources for prostate brachytherapy treatment

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Loss of I-125 seeds after perineal implantation of the prostate

International Nuclear Information System (INIS)

Wopereis, A.J.M.; Moerland, M.A.; Koning, J.H.A.G. de; Battermann, J.J.

1996-01-01

Introduction: One of the treatment modalities of early stage prostate cancer is the permanent implantation of I-125 seeds. The aim of this study was to obtain insight in the loss of seeds after implantation. Methods and Materials: During the past 6 years, 100 patients were treated and examined. Radiographs of the prostate area were taken at discharge (after 2 or 3 days) and combined with a follow-up appointment, successively after 1, 3, 6, 12 and 24 months. 10 patients were excluded from this study because of a later performed prostatectomy or TURP. During the hospitalisation period the patient's excrements were examined for lost seeds. Furthermore patients were instructed to urinate through a tea-strainer in the first month following implantation in order to prevent seeds from entering the sewage system. Results: We observed an overall loss of 5% during the entire follow-up period of 2 years. Further analysis of the obtained data showed that most of the seeds (3% of the implanted seeds) were lost in the first 2 days after implantation. Due to special attention paid to safety measures, 94% of the lost seeds were retrieved during the admission period. Because of adequate instructions given to the patients, 70% of the seeds lost during the first month after discharge (0.5% of the total number of remaining implanted seeds) were also retrieved. Losing seeds during the first month after implantation did not increase the chance of further loss later on. A total of 13 seeds (in all patients) was lost after 1 month (of which 6 were lost after more then one year and are for radiation safety reasons not of importance). Conclusions: Most seeds are lost during the first days after implantation. Therefore, radiographs are indicated at discharge, after 1 month (for evaluation of safety precautions) and after 1 year as a conclusion to the treatment

Evaluation of material heterogeneity dosimetric effects using radiochromic film for COMS eye plaques loaded with 125I seeds (model I25.S16)

International Nuclear Information System (INIS)

Acar, Hilal; Chiu-Tsao, Sou-Tung; Özbay, İsmail; Kemikler, Gönül; Tuncer, Samuray

2013-01-01

Purpose: (1) To measure absolute dose distributions in eye phantom for COMS eye plaques with 125 I seeds (model I25.S16) using radiochromic EBT film dosimetry. (2) To determine the dose correction function for calculations involving the TG-43 formalism to account for the presence of the COMS eye plaque using Monte Carlo (MC) method specific to this seed model. (3) To test the heterogeneous dose calculation accuracy of the new version of Plaque Simulator (v5.3.9) against the EBT film data for this seed model. Methods: Using EBT film, absolute doses were measured for 125 I seeds (model I25.S16) in COMS eye plaques (1) along the plaque's central axis for (a) uniformly loaded plaques (14–20 mm in diameter) and (b) a 20 mm plaque with single seed, and (2) in off-axis direction at depths of 5 and 12 mm for all four plaque sizes. The EBT film calibration was performed at 125 I photon energy. MC calculations using MCNP5 code for a single seed at the center of a 20 mm plaque in homogeneous water and polystyrene medium were performed. The heterogeneity dose correction function was determined from the MC calculations. These function values at various depths were entered into PS software (v5.3.9) to calculate the heterogeneous dose distributions for the uniformly loaded plaques (of all four sizes). The dose distributions with homogeneous water assumptions were also calculated using PS for comparison. The EBT film measured absolute dose rate values (film) were compared with those calculated using PS with homogeneous assumption (PS Homo) and heterogeneity correction (PS Hetero). The values of dose ratio (film/PS Homo) and (film/PS Hetero) were obtained. Results: The central axis depth dose rate values for a single seed in 20 mm plaque measured using EBT film and calculated with MCNP5 code (both in ploystyrene phantom) were compared, and agreement within 9% was found. The dose ratio (film/PS Homo) values were substantially lower than unity (mostly between 0.8 and 0.9) for all

Dosimetry on ocular brachytherapy with ROPE plaque with iodine{sub 1}25 and palladium-103;Dosimetria em braquiterapia ocular com placa ROPES contando sementes de iodo-125 e paladio-103

Energy Technology Data Exchange (ETDEWEB)

Mourao, Arnaldo P. [Centro Federal de Educacao Tecnologica (CEFET/MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar; Campos, Tarcisio [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares

2009-07-01

Radiotherapy is an alternative to ocular enucleation. However, the irradiation of ocular region can bring deleterious effects due to the high doses, mainly in the lens, retina and in the bone structures in growth phase. Brachytherapy instead of teletherapy looks for 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)

EchoSeed Model 6733 Iodine-125 brachytherapy source: Improved dosimetric characterization using the MCNP5 Monte Carlo code

Energy Technology Data Exchange (ETDEWEB)

Mosleh-Shirazi, M. A.; Hadad, K.; Faghihi, R.; Baradaran-Ghahfarokhi, M.; Naghshnezhad, Z.; Meigooni, A. S. [Center for Research in Medical Physics and Biomedical Engineering and Physics Unit, Radiotherapy Department, Shiraz University of Medical Sciences, Shiraz 71936-13311 (Iran, Islamic Republic of); Radiation Research Center and Medical Radiation Department, School of Engineering, Shiraz University, Shiraz 71936-13311 (Iran, Islamic Republic of); Comprehensive Cancer Center of Nevada, Las Vegas, Nevada 89169 (United States)

2012-08-15

This study primarily aimed to obtain the dosimetric characteristics of the Model 6733 {sup 125}I seed (EchoSeed) with improved precision and accuracy using a more up-to-date Monte-Carlo code and data (MCNP5) compared to previously published results, including an uncertainty analysis. Its secondary aim was to compare the results obtained using the MCNP5, MCNP4c2, and PTRAN codes for simulation of this low-energy photon-emitting source. The EchoSeed geometry and chemical compositions together with a published {sup 125}I spectrum were used to perform dosimetric characterization of this source as per the updated AAPM TG-43 protocol. These simulations were performed in liquid water material in order to obtain the clinically applicable dosimetric parameters for this source model. Dose rate constants in liquid water, derived from MCNP4c2 and MCNP5 simulations, were found to be 0.993 cGyh{sup -1} U{sup -1} ({+-}1.73%) and 0.965 cGyh{sup -1} U{sup -1} ({+-}1.68%), respectively. Overall, the MCNP5 derived radial dose and 2D anisotropy functions results were generally closer to the measured data (within {+-}4%) than MCNP4c and the published data for PTRAN code (Version 7.43), while the opposite was seen for dose rate constant. The generally improved MCNP5 Monte Carlo simulation may be attributed to a more recent and accurate cross-section library. However, some of the data points in the results obtained from the above-mentioned Monte Carlo codes showed no statistically significant differences. Derived dosimetric characteristics in liquid water are provided for clinical applications of this source model.

Fast cross-projection algorithm for reconstruction of seeds in prostate brachytherapy

International Nuclear Information System (INIS)

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

2002-01-01

A fast method of seed matching and reconstruction in prostrate brachytherapy is proposed. Previous approaches have required all seeds to be matched with all other seeds in other projections. The fast cross-projection algorithm for the reconstruction of seeds (Fast-CARS) allows for matching of a given seed with a subset of seeds in other projections. This subset lies in a proximal region centered about the projection of a line, connecting the seed to its source, onto other projection planes. The proposed technique permits a significant reduction in computational overhead, as measured by the required number of matching tests. The number of multiplications and additions is also vastly reduced at no trade-off in accuracy. Because of its speed, Fast-CARS can be used in applications requiring real-time performance such as intraoperative dosimetry of prostate brachytherapy. Furthermore, the proposed method makes practical the use of a larger number of views as opposed to previous techniques limited to a maximum use of three views

Exposure of treating physician to radiation during prostate brachytherapy using iodine-125 seeds. Dose measurements on both hands with thermoluminescence dosimeters

International Nuclear Information System (INIS)

Schiefer, Hans; Seelentag, Wolf; Plasswilm, Ludwig; Ries, Gerhard; Toggenburg, Friedrich von; Lenggenhager, Cornelius; Schmid, Hans-Peter; Leippold, Thomas; Engeler, Daniel; Prikler, Ladislav; Krusche, Bernd; Roth, Jakob

2009-01-01

Background and purpose: only sparse reports have been made about radiation exposure of the treating physician during prostate seed implantation. Therefore, thermoluminescence dosimeter (TLD) measurements on the index fingers and the backs of both hands were conducted. Material and methods: stranded iodine-125 seeds with a mean apparent activity of 27.4 MBq per seed were used. During application, the treating physician manipulated the loaded needle with the index fingers, partially under fluoroscopic control. Four physicians with varying experience treated 24 patients. The radiation exposure was determined with TLD-100 chips attached to the index fingertips and the backs of hands. Radiation exposure was correlated with the physician's experience. Results: the average brachytherapy duration by the most experienced physician was 19.2 min (standard deviation σ = 1.2 min; novices: 34.8 min [σ = 10.2 min]). The mean activity was 1,703 MBq (σ = 123 MBq), applied with 16.3 needles (σ = 2.5 needles; novices: 1,469 MBq [σ = 229 MBq]; 16.8 needles [σ = 2.3 needles ]). The exposure of the finger of the ''active hand'' and the back of the hand amounted to 1.31 mSv (σ = 0.54 mSv) and 0.61 mSv (σ = 0.23 mSv), respectively (novices: 2.07 mSv [σ = 0.86 mSv] and 1.05 mSv [σ = 0.53 mSv]). Conclusion: if no other radiation exposure needs to be considered, an experienced physician can perform about 400 applications per year without exceeding the limit of 500 mSv/year; for novices, the corresponding figure is about 200. (orig.)

Clinical application of permanent implantation of iodine 125 seeds for osseous metastases

International Nuclear Information System (INIS)

Li Jinxin; Zhang Qizhou; Li Guoliang

2010-01-01

Objective: To evaluate the clinical efficacy of permanent implantation of iodine 125 seeds in the treatment of osseous metastases. Methods: Radioactive iodine 125 seeds were implanted permanently in 32 lesions of 25 patients with osseous metastases of different origins. The ostalgia-relieving degree and the imaging alterations of the osseous metastasis lesions were observed. Results: The effective pain-relieving rate was 92% caused by permanent implantation of iodine 125 seeds. Of al 1 the patients, 15 patients achieved complete response, 8 patients obtained partial response (PR), and 2 patients had no change. The pain grade was decreased significantly after the treatment (P 125 I seeds has a definite effect on tumor metastasis and caused minimal damage and few complications. It is worthy of popularization in clinic. (authors)

CT-guided percutaneous vertebroplasty combined with 125I-seed implantation for metastatic vertebral carcinoma involving the spinal canal: analysis of 23 cases

International Nuclear Information System (INIS)

Xie Xiaoxi; Lu Yinxiang; Ji Yong; Wang Xiaowei; Zhang Guodong

2014-01-01

Objective: To evaluate the safety and efficacy of CT-guided percutaneous vertebroplasty (PVP) combined with 125 I-seed implantation for the treatment of metastatic vertebral carcinoma involving the spinal canal. Methods: A total of 28 involved vertebrae were detected in 23 patients with metastatic vertebral carcinoma. Each patient had 1-2 diseased vertebrae. The lesions included cervical vertebra (n=4), thoracic vertebra (n=13) and lumbar vertebra (n=11). Destroyed posterior vertebral wall was seen in all involved vertebrae. Thirteen vertebrae found in 12 patients showed involvement of the epidural space. According to treatment planning system (TPS) CT-guided implantation of 125 I seeds was carried out first for cervical lesions, which was followed by PVP. For the thoracic and lumbar lesions, unilateral or bilateral puncturing with several particle needles was employed to implant the 125 I seeds, then, PVP with bone cement injection was performed. The complications and the clinical efficacy were analyzed. Results: Successful operation was obtained in all patients. The number of implanted 125 I seeds ranged from 4 to 30 per vertebra, and the volume of injected bone cement was 1-6 ml per vertebra. After the operation the pain relief rate was 86.9% (n=20). The incidence of bone cement leakage was 17.8% (5/28). One patient had radicular pain caused by neuropore leakage, which was relieved after medication. No serious complications, such as spinal cord injury or radiation myelitis, occurred. Conclusion: CT-guided PVP combined with 125 I-seed implantation is effective and safe for the treatment of metastatic vertebral carcinoma involving the spinal canal. This therapy can effectively relieve the pain and control the deterioration of tumor, besides, the incidence of bone cement leakage is very low. (authors)

Effects of radioactive 125I seeds on A549 cell line and human embryonic lung diploid cell line 2BS cultivated in vitro and assessment of its clinical safety dose

International Nuclear Information System (INIS)

Bian Wenchao; Qi Liangchen

2012-01-01

Objective: To observe the cell count changes of A549 cell line and human embryonic lung diploid cell line 2BS after irradiated by 125 I seeds with different doses, and to study the growth inhibition of 125 I on this two kinds of cell lines, and to determine its clinical safety dose in treatment of non-small cell lung. Methods: 125 I seeds with different doses (low dose: 0.2 mCi, mediate dose: 0.4 mCi, high dose: 0.8 mCi) were chosen and put into A549 cells and human embryonic lung diploid cell line 2BS in vitro, the cells on the 2nd, 4th, 6th and 8th days after irradiation were collected, the alive cells were counted by cells dyeing experiments, then the growth curves were drawn, and the IC 50 of the radioactive 125 I seeds to both two cell lines were calculated. Results: Compared with blank and control groups, the cell proliferation trend of A549 cells in low dose group was not significantly influenced (P>0.05), but the growth of A549 cells in mediate and high dose groups were inhibited in a time-dependent manner, there were significant differences (P<0.05), the most obvious change was on the 6th day. The IC 50 of the radioactive 125 I seeds to A549 cells was about .04 mCi. While the growth inhibition of 125 I 2BS had no statistically significant differences between various dose groups (P>0.05), and the IC 50 of the radioactive 125 I seeds to 2BS cell line was about 1.65 mCi. Conclusion: 0.4 mCi of radioactive 125 I seeds has already had the obvious damage effect on A549 cell, 0.8 mCi of radioactive 125 I seeds has the stronger effect. The IC 50 of the radioactive 125 I seeds to 2BS cells is about 1.65 mCi, so the clinical safety dosage is 0.4-0.8 mCi. (authors)

SU-E-T-259: Particle Swarm Optimization in Radial Dose Function Fitting for a Novel Iodine-125 Seed

Energy Technology Data Exchange (ETDEWEB)

Wu, X [University of Alabama at Birmingham, Birmingham, Al (United States); Duan, J; Popple, R; Huang, M; Shen, S; Brezovich, I [University of Alabama Birmingham, Birmingham, AL (United States); Cardan, R [UAB University of Alabama, Birmingham, Birmingham, AL (United States); Benhabib, S [University of Alabama at Birmingham, Birmingham, AL (United States)

2014-06-01

Purpose: To determine the coefficients of bi- and tri-exponential functions for the best fit of radial dose functions of the new iodine brachytherapy source: Iodine-125 Seed AgX-100. Methods: The particle swarm optimization (PSO) method was used to search for the coefficients of the biand tri-exponential functions that yield the best fit to data published for a few selected radial distances from the source. The coefficients were encoded into particles, and these particles move through the search space by following their local and global best-known positions. In each generation, particles were evaluated through their fitness function and their positions were changed through their velocities. This procedure was repeated until the convergence criterion was met or the maximum generation was reached. All best particles were found in less than 1,500 generations. Results: For the I-125 seed AgX-100 considered as a point source, the maximum deviation from the published data is less than 2.9% for bi-exponential fitting function and 0.2% for tri-exponential fitting function. For its line source, the maximum deviation is less than 1.1% for bi-exponential fitting function and 0.08% for tri-exponential fitting function. Conclusion: PSO is a powerful method in searching coefficients for bi-exponential and tri-exponential fitting functions. The bi- and tri-exponential models of Iodine-125 seed AgX-100 point and line sources obtained with PSO optimization provide accurate analytical forms of the radial dose function. The tri-exponential fitting function is more accurate than the bi-exponential function.

CT-guided iodine-125 seed permanent implantation for recurrent head and neck cancers

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yu L; Meng, Na; Wang, Jun J; Jiang, Ping [Department of Radiation Oncology, Peking University Third Hospital, Beijing 100191 (China); Yuan, Hui SH; Liu, Chen [Department of Radiology, Peking University Third Hospital, Beijing, 100191 (China); Qu, Ang; Yang, Rui J [Department of Radiation Oncology, Peking University Third Hospital, Beijing 100191 (China)

2010-07-30

To investigate the feasibility, and safety of {sup 125}I seed permanent implantation for recurrent head and neck carcinoma under CT-guidance. A retrospective study on 14 patients with recurrent head and neck cancers undergone {sup 125}I seed implantation with different seed activities. The post-plan showed that the actuarial D90 of {sup 125}I seeds ranged from 90 to 218 Gy (median, 157.5 Gy). The follow-up was 3 to 60 months (median, 13 months). The median local control was 18 months (95% CI, 6.1-29.9 months), and the 1-, 2-, 3-, and 5- year local controls were 52%, 39%, 39%, and 39%, respectively. The 1-, 2-, 3-, and 5- survival rates were 65%, 39%, 39% and 39%, respectively, with a median survival time of 20 months (95% CI, 8.7-31.3 months). Of all patients, 28.6% (4/14) died of local recurrence, 7.1% (1/14) died of metastases, one patient died of hepatocirrhosis, and 8 patients are still alive to the date of data analysis. CT-guided {sup 125}I seed implantation is feasible and safe as a salvage or palliative treatment for patients with recurrent head and neck cancers.

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

International Nuclear Information System (INIS)

Crook, Juanita; Patil, Nikhilesh; Wallace, Kris; Borg, Jette; Zhou, David; Ma, Clement; Pond, Greg

2010-01-01

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.

A Novel Self-Expandable, Radioactive Airway Stent Loaded with 125I Seeds: A Feasibility and Safety Study in Healthy Beagle Dog.

Science.gov (United States)

Wang, Yong; Guo, Jin-He; Zhu, Guang-Yu; Zhu, Hai-Dong; Chen, Li; Lu, Jian; Wang, Chao; Teng, Gao-Jun

2017-07-01

Airway stent placement is an effective treatment for the immediate palliation of malignant airway obstruction. However, restenosis caused by tumor ingrowth and/or overgrowth after stenting is common. The purpose of this study was to investigate the feasibility and safety of a novel self-expandable stent loaded with 125 I seeds in healthy beagle dog. Under fluoroscopic guidance, forty-eight self-expandable airway stents loaded with 125 I seeds were perorally placed in the main trachea of 48 healthy beagle dogs, who were randomly divided into four groups (Group A: 0.3 mCi; Group B: 0.6 mCi; Group C: 0.9 mCi; Control group: 0 mCi). The estimated radiation dose was calculated using the isotropic point source approximation. Radiological follow-up examinations and histopathological examinations of stented tracheal segments and their adjacent organs and tissues were performed at 2, 4, 8, and 16 weeks following the stenting. All stents were successfully deployed in the targeted tracheal segment in the beagle dogs without procedure-related complications. Tracheal stenosis became severe gradually in all the four groups, which was not associated with the radioactivity of 125 I seeds (p > 0.05). The tracheal injury scores increased along with the higher dose of radioactive seeds which reached peak at 8 weeks and then turned back slightly at 16 weeks. The adjacent tissue did not show pathohistological changes under microscope, while mild and reversible ultrastructure changes were showed under electronic microscope. This study demonstrates that it is feasible and safe to insert this novel self-expandable airway stent loaded with 125 I seeds in healthy beagle dog.

Bystander Effects Induced by Continuous Low-Dose-Rate 125I Seeds Potentiate the Killing Action of Irradiation on Human Lung Cancer Cells In Vitro

International Nuclear Information System (INIS)

Chen, H.H.; Jia, R.F.; Yu, L.; Zhao, M.J.; Shao, C.L.; Cheng, W.Y.

2008-01-01

Purpose: To investigate bystander effects of low-dose-rate (LDR) 125 I seed irradiation on human lung cancer cells in vitro. Methods and Materials: A549 and NCI-H446 cell lines of differing radiosensitivity were directly exposed to LDR 125 I seeds irradiation for 2 or 4 Gy and then cocultured with nonirradiated cells for 24 hours. Induction of micronucleus (MN), γH2AX foci, and apoptosis were assayed. Results: After 2 and 4 Gy irradiation, micronucleus formation rate (MFR) and apoptotic rate of A549 and NCI-H446 cells were increased, and the MFR and apoptotic rate of NCI-H446 cells was 2.1-2.8 times higher than that of A549 cells. After coculturing nonirradiated bystander cells with 125 I seed irradiated cells for 24 hours, MFR and the mean number of γH2AX foci/cells of bystander A549 and NCI-H446 cells were similar and significantly higher than those of control (p 125 I seeds could induce bystander effects, which potentiate the killing action on tumor cells and compensate for the influence of nonuniform distribution of radiation dosage on therapeutic outcomes

Edema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants - a bio-mathematical model

International Nuclear Information System (INIS)

Yue Ning; Chen Zhe; Nath, Ravinder

2002-01-01

Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125 I and 103 Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T)=V p (1+M exp(-0.693T/T e )) where V p is the prostate volume before implantation, M is the edema magnitude and T e is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. D radical S k Δg(r) φ-bar an /r 2 , where r is the distance between a seed and a given point. The distance r is now a function of time because of edema. The g(r) was approximated as 1/r 0.4 and 1/r 0.8 for 125 I and 103 Pd, respectively. By expanding the mathematical expression of the resultant dose rate in a Taylor series of exponential functions of time, the dose rate was made equivalent to that produced from multiple fictitious radionuclides of different decay constants and strengths. The biologically effective dose (BED) for an edematous prostate implant was then calculated using a generalized Dale equation. The cell surviving fraction was computed as exp(-αBED), where α is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125 I and 103 Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days

Intraoperative ultrasound quided iodine-125 seed implantation for unresectable pancreatic carcinoma

International Nuclear Information System (INIS)

Wang Junjie; Liu Jiangping; Jiang Yuliang; Jiang Weijuan; Li Jinna; Xiu Dianrong; Ran Weiqiang

2007-01-01

Objective: To investigate the surgical technique, efficacy and side effects of intraoperative ultrasound quided 125 I seed interstitial implantation for pancreatic carcinoma. Methods: Twenty-seven patients with biopsy proven unresectable adenocarcinoma of pancreas were treated with 125 I implants during laparotomy. Eleven patients were treated by a combination of bypass surgery. Seed needles were implanted parallel to each other, at 1.0-1.5 cm apart and guided by ultrasound. Mick applicator was applied to each needle to implant seed at 1.0-1.5 cm apart. The radioactive activity ranged 0.40-0.70 mCi; the D 90 were 110-160 Gy. The mean number of 125 I seed were 11-78. Six patients also received external beam radiation at doses of 39-50 Gy. Five patients received 2-4 cycle DDP + gemCitabine chemotherapy also. Results: The incidence of perioperative mortality was 0%. Pain was complete relieved in 15 patients, partial relieved in two, but in the rest three patients there was no response. The response rate was 85%. The starting time of pain relief was 1-30 d, with a median of 5 days. The overall local control rate was 74%. Four patients have died of recurrence, 20 patients died of metastasis, 3 patients died of recurrence and metastasis. The median survival of II + III[ stage patients was 8 months, with a 1- and 2-year survival of 25% and 15%, respectively. The median survival time of IV stage patients was 5 months, with 1-year survival of 8%. The seeds immigrated into the liver in 3 patients. There are no serious side effects such as infection or pancreatic fistula. Conclusions: Intraoperative ultrasound quided 125 I seed implantation is safe, giving high local control, but minimal damage. It is a satisfactorily palliative for pain and causing little noticeable complications. (authors)

Urethral toxicity after LDR brachytherapy: experience in Japan.

Science.gov (United States)

Tanaka, Nobumichi; Asakawa, Isao; Hasegawa, Masatoshi; Fujimoto, Kiyohide

2015-01-01

Urinary toxicity is common after low-dose-rate (LDR) brachytherapy, and the resolution of urinary toxicity is a concern. In particular, urinary frequency is the most common adverse event among the urinary toxicities. We have previously reported that approximately 70% of patients experience urinary frequency during the first 6 months after seed implantation. Most urinary adverse events were classified as Grade 1, and Grade 2 or higher adverse events were rare. The incidence of urinary retention was approximately 2-4%. A high International Prostate Symptom Score before seed implantation was an independent predictor of acute urinary toxicity of Grade 2 or higher. Several previous reports from the United States also supported this trend. In Japan, LDR brachytherapy was legally approved in 2003. A nationwide prospective cohort study entitled Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation was initiated in July 2005. It is an important issue to limit urinary toxicities in patients who undergo LDR brachytherapy. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Effect of implanted radioactive 125I seeds on normal tissue structures of bronchus, esophagus, pulmonary artery, pulmonary vein and alveolus in dogs

International Nuclear Information System (INIS)

Qi Liangchen; Han Zhenguo; Yang Bin; Heersitai

2008-01-01

Objective: To investigate the effect of implanted radioactive 125 I seeds on normal tissue structures of bronchus, esophagus, pulmonary artery, pulmonary vein and alveolus in dogs. Methods: Nine healthy male dogs weighing 17-21 kg were randomly divided into three groups: 30 d, 60 d experimental groups and control group. Radioactive 125 I seeds (3.7 x 10 7 Bg, 1.0 mCi) were implanted into the sides of bronchus, esophagus, pulmonary artery, pulmonary vein respectively, the samples of bronchus, esophagus, pulmonary artery, pulmonary vein were taken 30 and 60 d after transplantation, HE staining was used to observe the pathologic changes of the tissues under light microscope. Results: The damages of normal bronchus, esophagus, pulmonary artery, pulmonary vein and alveolus after radioactive 125 I seeds implantation in 30 d group were weaker than those in control group and 60 d group, there were no complications such as perforation, hemorrhage, necrosis, etc. Histopathological score indicated that the scores of bronchus, esophagus and alveolar in 30 d group and 60 d group were higher than those in control group (P 0.05); there was no significant difference in histopathological score of pulmonary vein among all groups (P>0.05). Conclusion: The implanted radioactive 125 I seeds can damage all kinds of tissues at different degrees, but this kind of damage is reversible, the dog may repair the damage through its own repair ability, its clinical application is safe. (authors)

SU-E-T-378: Evaluation of An Analytical Model for the Inter-Seed Attenuation Effect in 103-Pd Multi-Seed Implant Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

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

2015-06-15

Purpose: Brachytherapy treatment planning systems based on TG-43 protocol calculate the dose in water and neglects the heterogeneity effect of seeds in multi-seed implant brachytherapy. In this research, the accuracy of a novel analytical model that we propose for the inter-seed attenuation effect (ISA) for 103-Pd seed model is evaluated. Methods: In the analytical model, dose perturbation due to the ISA effect for each seed in an LDR multi-seed implant for 103-Pd is calculated by assuming that the seed of interest is active and the other surrounding seeds are inactive. The cumulative dosimetric effect of all seeds is then summed using the superposition principle. The model is based on pre Monte Carlo (MC) simulated 3D kernels of the dose perturbations caused by the ISA effect. The cumulative ISA effect due to multiple surrounding seeds is obtained by a simple multiplication of the individual ISA effect by each seed, the effect of which is determined by the distance from the seed of interest. This novel algorithm is then compared with full MC water-based simulations (FMCW). Results: The results show that the dose perturbation model we propose is in excellent agreement with the FMCW values for a case with three seeds separated by 1 cm. The average difference of the model and the FMCW simulations was less than 8%±2%. Conclusion: Using the proposed novel analytical ISA effect model, one could expedite the corrections due to the ISA dose perturbation effects during permanent seed 103-Pd brachytherapy planning with minimal increase in time since the model is based on multiplications and superposition. This model can be applied, in principle, to any other brachytherapy seeds. Further work is necessary to validate this model on a more complicated geometry as well.

Development of irradiation support devices for production of brachytherapy seeds

International Nuclear Information System (INIS)

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.

2013-01-01

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)

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

International Nuclear Information System (INIS)

Zeituni, Carlos A.; Moura, Eduardo S.; Rostelato, Maria Elisa C.M.; Manzoli, Jose E.; Moura, Joao Augusto; Feher, Anselmo; Karam, Dib

2009-01-01

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)

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

Energy Technology Data Exchange (ETDEWEB)

Zeituni, Carlos A.; Moura, Eduardo S.; Rostelato, Maria Elisa C.M.; Manzoli, Jose E.; Moura, Joao Augusto; Feher, Anselmo, E-mail: czeituni@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Karam, Dib [Universidade de Sao Paulo (USP Leste), Sao Paulo, SP (Brazil). Escola de Artes, Ciencias e Humanidades

2009-07-01

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)

Study on interstitial brachytherapy using 103Pd seeds on tumor-bearing rats

International Nuclear Information System (INIS)

Feng Huiru; Zhang Jingming; Tian Jiahe; Ding Weimin; Bai Hongsheng; Jin Xiaohai

2003-01-01

The effects of low-dose-rate brachytherapy are investigated in tumor-bearing rat. Walker 256 cells are transplanted subcutaneously with a trocar in the left leg of rats (Wistar). Two weeks later, rats with a tumor of 10 mm in mean diameter are divided into three groups (10 per group). Two groups are given 1 seed and 2 seeds implantation of 103 Pd, respectively, the third group is as an untreated control. Tumor size is measured twice a week until the 25th day when the rats are killed. Tumor is monitored either by palpation or further confirmed by histopathology. Kaplan-Meier statistic method is performed for survival analysis. The results show that the average weight of rats in untreated group is lower than in radiation groups (P 0.05). Tumor volumes in all treatment groups increase more obviously than in control till 16 days post-implantation. Tumor regression rate in 1 seed group is higher than in control group and in 2 seeds group. Although survival analysis show that the median survival time in 1 seed, 2 seeds and control groups are 24±0, 21±2 and 19±2 days with survival rate of 80%, 60% and 50% respectively, no significant differences are seen in all groups. So, brachytherapy with 103 Pd seed is effective on tumor-bearing rats. The implantation of seed can cause tumor edema in a self-limited way. A reasonable doses chosen for brachytherapy may play a role in treatment success

SU-F-T-02: Estimation of Radiobiological Doses (BED and EQD2) of Single Fraction Electronic Brachytherapy That Equivalent to I-125 Eye Plaque: By Using Linear-Quadratic and Universal Survival Curve Models

International Nuclear Information System (INIS)

Kim, Y; Waldron, T; Pennington, E

2016-01-01

Purpose: To test the radiobiological impact of hypofractionated choroidal melanoma brachytherapy, we calculated single fraction equivalent doses (SFED) of the tumor that equivalent to 85 Gy of I125-BT for 20 patients. Corresponding organs-at-risks (OARs) doses were estimated. Methods: Twenty patients treated with I125-BT were retrospectively examined. The tumor SFED values were calculated from tumor BED using a conventional linear-quadratic (L-Q) model and an universal survival curve (USC). The opposite retina (α/β = 2.58), macula (2.58), optic disc (1.75), and lens (1.2) were examined. The % doses of OARs over tumor doses were assumed to be the same as for a single fraction delivery. The OAR SFED values were converted into BED and equivalent dose in 2 Gy fraction (EQD2) by using both L-Q and USC models, then compared to I125-BT. Results: The USC-based BED and EQD2 doses of the macula, optic disc, and the lens were on average 118 ± 46% (p 14 Gy). Conclusion: The estimated single fraction doses were feasible to be delivered within 1 hour using a high dose rate source such as electronic brachytherapy (eBT). However, the estimated OAR doses using eBT were 112 ∼ 118% higher than when using the I125-BT technique. Continued exploration of alternative dose rate or fractionation schedules should be followed.

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)

Moura, Joao Augusto

2009-01-01

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

Novel prostate brachytherapy technique: Improved dosimetric and clinical outcome

International Nuclear Information System (INIS)

Nobes, Jenny P.; Khaksar, Sara J.; Hawkins, Maria A.; Cunningham, Melanie J.; Langley, Stephen E.M.; Laing, Robert W.

2008-01-01

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 (D 25 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

Dynamic observation on changes of serum tumor markers levels after implantation of 125I radioactive seeds as treatment for several malignancies

International Nuclear Information System (INIS)

Sun Qihe; Yang Jiali; Gao Mingzhong

2005-01-01

Objective: To study the dynamic changes of serum levels of several tumor markers after implantation of 125 I seeds as treatment for breast, prostate and lung malignancies. Methods: Serum CA15-3 (in 48 cases of breast cancer), PSA (in 59 cases of prostate cancer) and CYFRA21-1 (in 59 cases of lung cancer) levels were measured with RIA both before and after implantation of 125 I seeds as treatment. Furthermore, dynamic observation on the serum markers levels was carried out every 3 months in ten patients in each category. Results: After treatment, levels of these markers dropped significantly. Dynamic observation revealed that in the 10 cases of breast cancer, the levels of CA15-3 dropped continually. However, in the 10 cases of prostatic cancer, the disease got worse and the PSA levels kept increasing. In the lung cancer group, the CYFRA21-1 levels rose markedly and all patients expired before 9 months. Conclusion: Dynamic observation on changes of serum tumor markers (CA15-3, PSA, CYFRA21-1) levels after 125 I seed implantation treatment was of definite prognostic value. (authors)

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

International Nuclear Information System (INIS)

Saidi, Pooneh; Sadeghi, Mahdi; Enferadi, Milad; Aslani, Gholamreza

2011-01-01

Highlights: → We report the cyclotron production of 103-palladium via 103 Rh(p,n) 103 Pd reaction. → 103 Pd was absorbed on resin beads for brachytherapy seed preparation. → The optimum absorption of 103 Pd in resin was achieved at 0.5 M HCl. → Version 5 of MCNP code was employed to model a new 103 Pd brachytherapy seed. - Abstract: In this study, design and fabrication of 103 Pd brachytherapy seed was investigated. The excitation functions of 103 Rh(p,n) 103 Pd and 103 Rh(d,2n) 103 Pd 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 103 Pd was done via 103 Rh(p,n) 103 Pd 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 103 Pd 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 103 Pd brachytherapy seed. Finally the calculated results were compared with published results for other commercial sources.

Sci-Sat AM(2): Brachy-07: Tomosynthesis-based seed reconstruction in LDR prostate brachytherapy: A clinical study.

Science.gov (United States)

Brunet-Benkhoucha, M; Verhaegen, F; Lassalle, S; Béliveau-Nadeau, D; Reniers, B; Donath, D; Taussky, D; Carrier, J-F

2008-07-01

To develop a tomosynthesis-based dose assessment procedure that can be performed after an I-125 prostate seed implantation, while the patient is still under anaesthesia on the treatment table. Our seed detection procedure involves the reconstruction of a volume of interest based on the backprojection of 7 seed-only binary images acquired over an angle of 60° with an isocentric imaging system. A binary seed-only volume is generated by a simple thresholding of the volume of interest. Seeds positions are extracted from this volume with a 3D connected component analysis and a statistical classifier that determines the number of seeds in each cluster of connected voxels. A graphical user interface (GUI) allows to visualize the result and to introduce corrections, if needed. A phantom and a clinical study (24 patients) were carried out to validate the technique. A phantom study demonstrated a very good localization accuracy of (0.4+/-0.4) mm when compared to CT-based reconstruction. This leads to dosimetric error on D90 and V100 of respectively 0.5% and 0.1%. In a patient study with an average of 56 seeds per implant, the automatic tomosynthesis-based reconstruction yields a detection rate of 96% of the seeds and less than 1.5% of false-positives. With the help of the GUI, the user can achieve a 100% detection rate in an average of 3 minutes. This technique would allow to identify possible underdosage and to correct it by potentially reimplanting additional seeds. A more uniform dose coverage could then be achieved in LDR prostate brachytherapy. © 2008 American Association of Physicists in Medicine.

Deterministic calculations of radiation doses from brachytherapy seeds

International Nuclear Information System (INIS)

Reis, Sergio Carneiro dos; Vasconcelos, Vanderley de; Santos, Ana Maria Matildes dos

2009-01-01

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 ( 192 Ir, 198 Au, 137 Cs and 60 Co). 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)

Effect of permanent 103Pd radioactive seed implantation on brachytherapy of malignant tumor

International Nuclear Information System (INIS)

Chen Ping; Wei Xianzhong; Liu Yanmin; Wu Kaijun; Liang Jianxin; Chen Hanzhang

2003-01-01

Objective: To investigate and assess the brachytherapeutic effectiveness of 103 Pd radioactive seeds in malignant tumor therapy. Methods: 196.1-2127.5 MBq 103 Pd seeds were implanted in 21 confirmed malignant tumor patients. The seeds were evenly scattered in 15/21 patients' tumors and peripherally in the remaining 6 cases' tumors. The size and shape, local recurrence and remote metastasis of the tumors were observed. Results: The brachytherapy of 103 Pd seeds in tumor patients resulted in obvious efficacy. No local recurrence and remote metastasis were observed. 19/21 (90.5%) patients scored 0 and 2/21 (9.5%) of them scored 1 in skin acute radiation morbidity scoring criteria within the observation period. Conclusion: The 103 Pd seeds can be safely used in brachytherapy of malignant tumors with lower or medium sensitivity to radiation therapy

SU-F-T-43: Prediction of Dose Increments by Brain Metastases Resection Cavity Shrinkage Model with I-125 and Cs-131 LDR Seed Implantations

Energy Technology Data Exchange (ETDEWEB)

Han, D; Braunstein, S; Sneed, P; McDermott, M; Ma, L [University of California San Francisco, San Francisco, CA (United States)

2016-06-15

Purpose: This work aims to determine dose variability via a brain metastases resection cavity shrinkage model (RC-SM) with I-125 or Cs-131 LDR seed implantations. Methods: The RC-SM was developed to represent sequential volume changes of 95 consecutive brain metastases patients. All patients underwent serial surveillance MR and change in cavity volume was recorded for each patient. For the initial resection cavity, a prolate-ellipsoid cavity model was suggested and applied volume shrinkage rates to correspond to 1.7, 3.6, 5.9, 11.7, and 20.5 months after craniotomy. Extra-ring structure (6mm) was added on a surface of the resection volume and the same shrinkage rates were applied. Total 31 LDR seeds were evenly distributed on the surface of the resection cavity. The Amersham 6711 I-125 seed model (Oncura, Arlington Heights, IL) and the Model Cs-1 Rev2 Cs-131 seed model (IsoRay, Richland, WA) were used for TG-43U1 dose calculation and in-house-programed 3D-volumetric dose calculation system was used for resection cavity rigid model (RC-RM) and the RC-SM dose calculation. Results: The initial resection cavity volume shrunk to 25±6%, 35±6.8%, 42±7.7%, 47±9.5%, and 60±11.6%, with respect to sequential MR images post craniotomy, and the shrinkage rate (SR) was calculated as SR=56.41Xexp(−0.2024Xt)+33.99 and R-square value was 0.98. The normal brain dose as assessed via the dose to the ring structure with the RC-SM showed 29.34% and 27.95% higher than the RC-RM, I-125 and Cs-131, respectively. The dose differences between I-125 and Cs-131 seeds within the same models, I-125 cases were 9.17% and 10.35% higher than Cs-131 cases, the RC-RM and the RC-SM, respectively. Conclusion: A realistic RC-SM should be considered during LDR brain seed implementation and post-implement planning to prevent potential overdose. The RC-SM calculation shows that Cs-131 is more advantageous in sparing normal brain as the resection cavity volume changes with the LDR seeds implementation.

Comparison of seed brachytherapy or external beam radiotherapy (70 Gy or 74 Gy) in 919 low-risk prostate cancer patients

Energy Technology Data Exchange (ETDEWEB)

Goldner, G.; Poetter, R.; Schmid, M.P.; Kirisits, C. [University Hospital of Vienna (Austria). Dept. of Radiotherapy and Radiobiology; Battermann, J.J.; Sljivic, S.; Vulpen, M. van [University Medical Center Utrecht (Netherlands). Dept. of Radiation Oncology

2012-04-15

The aim of this analysis was to compare the biochemical no evidence of disease (bNED) rates in low-risk prostate cancer patients treated at two centers of excellence using different approaches: seed brachytherapy (BT) and external beam radiotherapy (EBRT). Materials and methods: A total of 919 low-risk prostate cancer patients, treated from 1998-2008, were identified in the two databases. In Utrecht, 667 patients received I-125 BT applying a dose of 144 Gy. In Vienna, 252 patients were treated with EBRT, applying a local dose of 70 Gy in 82 patients and 74 Gy in 170 patients. bNED rates (Phoenix definition) were assessed. Results: The median follow-up was 46 months (range 1-148 months). The 5-year actuarial bNED rates were 94% for BT patients and 88% for EBRT patients (p = 0.002) - 84% for patients receiving 70 Gy and 91% for patients receiving 74 Gy, respectively. In the univariate analysis, patients receiving 70 Gy showed significantly worse outcome compared to BT (p = 0.001) and a difference close to significance compared to 74 Gy (p = 0.06). In the multivariate analysis including tumor stage, Gleason score, initial PSA, hormonal therapy, and dose, patients receiving 70 Gy EBRT showed significantly worse bNED rates compared to BT patients. Conclusion: Low-risk prostate cancer patients receiving 74 Gy by EBRT show comparable biochemical control rates to patients receiving seed brachytherapy, whereas patients receiving 70 Gy show significantly worse outcome. (orig.)

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)

Iodine-125 Seeds Strand for Treatment of Tumor Thrombus in Inferior Vena Cava: An Experimental Study in a Rabbit Model

International Nuclear Information System (INIS)

Zhang, Wen; Yan, Zhiping; Luo, Jianjun; Fang, Zhuting; Wu, Linlin; Liu, QingXin; Qu, Xudong; Liu, Lingxiao; Wang, Jianhua

2013-01-01

Objective: The purpose of this study was to establish an animal model of implanted inferior vena cava tumor thrombus (IVCTT) and to evaluate the effect of linear iodine-125 seeds strand in treating implanted IVCTT. Methods: Tumor cell line VX 2 was inoculated subcutaneously into New Zealand rabbit to develop the parent tumor. The tumor strip was inoculated into inferior vena cava (IVC) to establish the IVCTT model. The IVCTT was confirmed by multidetector computed tomography (MDCT) after 2 weeks. Twelve rabbits with IVCTT were randomly divided into two groups. Treatment group (group T; n = 6) underwent Iodine-125 seeds brachytherapy, and the control group (group C; n = 6) underwent blank seeds strand. The blood laboratory examination (including blood routine examination, hepatic and renal function), body weight, survival time, and IVCTT volume by MDCT were monitored. All rabbits were dissected postmortem, and the therapeutic effects were evaluated on the basis of histopathology. The proliferating cell nuclear antigen index (PI) and apoptosis index (AI) of IVCTT were compared between two groups. T test, Wilcoxon rank test, and Kaplan–Meier survival curve analysis were used. Results: The success rate of establishing IVCTT was 100 %. The body weight loss and cachexia of rabbits in group C appeared earlier than in group T. Body weight in the third week, the mean survival time, PI, AI in groups T and C were 2.23 ± 0.12 kg, 57.83 ± 8.68 days, (16.73 ± 5.18 %), (29.47 ± 7.18 %), and 2.03 ± 0.13 kg, 43.67 ± 5.28 days, (63.01 ± 2.01 %), (6.02 ± 2.93 %), respectively. There were statistically significant differences between group T and group C (P < 0.05). The IVCTT volume of group T was remarkably smaller than that of group C. Conclusions: Injecting and suspensory fixing VX2 tumor strip into IVC is a reliable method to establish IVCTT animal model. The linear Iodine-125 seeds strand brachytherapy was a safe and effective method for treating IVCTT in rabbit model

Iodine-125 Seeds Strand for Treatment of Tumor Thrombus in Inferior Vena Cava: An Experimental Study in a Rabbit Model

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wen; Yan, Zhiping; Luo, Jianjun; Fang, Zhuting; Wu, Linlin; Liu, QingXin; Qu, Xudong; Liu, Lingxiao; Wang, Jianhua [Fudan University, Department of Interventional Radiology, Zhongshan Hospital (China)

2013-10-15

Objective: The purpose of this study was to establish an animal model of implanted inferior vena cava tumor thrombus (IVCTT) and to evaluate the effect of linear iodine-125 seeds strand in treating implanted IVCTT. Methods: Tumor cell line VX{sub 2} was inoculated subcutaneously into New Zealand rabbit to develop the parent tumor. The tumor strip was inoculated into inferior vena cava (IVC) to establish the IVCTT model. The IVCTT was confirmed by multidetector computed tomography (MDCT) after 2 weeks. Twelve rabbits with IVCTT were randomly divided into two groups. Treatment group (group T; n = 6) underwent Iodine-125 seeds brachytherapy, and the control group (group C; n = 6) underwent blank seeds strand. The blood laboratory examination (including blood routine examination, hepatic and renal function), body weight, survival time, and IVCTT volume by MDCT were monitored. All rabbits were dissected postmortem, and the therapeutic effects were evaluated on the basis of histopathology. The proliferating cell nuclear antigen index (PI) and apoptosis index (AI) of IVCTT were compared between two groups. T test, Wilcoxon rank test, and Kaplan-Meier survival curve analysis were used. Results: The success rate of establishing IVCTT was 100 %. The body weight loss and cachexia of rabbits in group C appeared earlier than in group T. Body weight in the third week, the mean survival time, PI, AI in groups T and C were 2.23 {+-} 0.12 kg, 57.83 {+-} 8.68 days, (16.73 {+-} 5.18 %), (29.47 {+-} 7.18 %), and 2.03 {+-} 0.13 kg, 43.67 {+-} 5.28 days, (63.01 {+-} 2.01 %), (6.02 {+-} 2.93 %), respectively. There were statistically significant differences between group T and group C (P < 0.05). The IVCTT volume of group T was remarkably smaller than that of group C. Conclusions: Injecting and suspensory fixing VX2 tumor strip into IVC is a reliable method to establish IVCTT animal model. The linear Iodine-125 seeds strand brachytherapy was a safe and effective method for treating IVCTT

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)

Safety and efficacy of radioactive seed localization with I-125 prior to lumpectomy and/or excisional biopsy

International Nuclear Information System (INIS)

Sung, Janice S.; King, Valencia; Thornton, Cynthia M.; Brooks, Jennifer D.; Fry, Charles W.; El-Tamer, Mahmoud; Dauer, Lawrence T.; Brogi, Edi; St Germain, Jean M.; Morris, Elizabeth A.

2013-01-01

Purpose: To evaluate the safety and efficacy of pre-operative I-125 radioactive seed localization (RSL) as an alternative to wire localization (WL). Methods: A waiver was granted by the institutional review board for this HIPAA compliant study. Review of 356 consecutive single site nonpalpable mammographic and ultrasound guided I-125 RSLs done between November 2011 and April 2012 was conducted. Preoperative mammograms and specimen radiographs were reviewed for seed-target distance, lesion location, and target/seed removal. During a brief surgical training period, 35 of 356 women had both RSL and wire localization (WL) of the same lesion. Chi-square and single sample t-tests were used to compare margin status and duration of procedures. Results: Of the 356 RSLs, 303 (85.1%) were performed ≥1 day before surgery. Mammographic guidance was used in 330 (93%) and ultrasound in 26 (7%). Mean seed to target distance was 1 mm (range 0–20 mm); all targeted lesions were retrieved. In 31 women in whom mammographic guidance was used for both RSL and WL, median procedure time was not significantly different (RSL 9.0 min; WL 7.0 min; p = 0.91), and median seed migration distance was <1 mm (range 0–15 mm). No difference was detected between margin status with RSL alone versus WL (p = 0.40 and p = 0.65 for positive and <1 mm margins, respectively). Two adverse events occurred requiring an additional wire/surgery. Conclusion: RSL ≥ 1 day before surgery is a safe effective procedure for pre-operative localization, with few adverse events and surgical outcomes comparable to those achieved with wire localization

Computed tomographic-guided iodine-125 interstitial implants for malignant thoracic tumors

Energy Technology Data Exchange (ETDEWEB)

Huang, Qiming [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China); The Department of Radiology, Second Affiliated Hospital of Fujian Medical University, 34 Zhongshan Bei Road, Quanzhou 362000 (China); Chen, Jin; Chen, Qunlin [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China); Lai, Qingquan; Cai, Siqing [The Department of Radiology, Second Affiliated Hospital of Fujian Medical University, 34 Zhongshan Bei Road, Quanzhou 362000 (China); Luo, Kaidong [The Department of Radiology, Longyan Hosptial of Traditional Chinese Medical, 59 Longteng Middle Road, Longyan 364000 (China); Lin, Zhengyu, E-mail: linsinlan@yahoo.com.cn [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China)

2013-11-01

Purpose: To evaluate the feasibility and efficacy of percutaneous interstitial brachytherapy using iodine-125 ({sup 125}I) radioactive seeds under computed tomographic (CT) guidance for malignant thoracic tumors. Materials and methods: Forty-one patients (34 males, 7 females; 18–90 years; mean, 63.7 years) with 77 lesions (3 in the mediastinum, 7 in the chest wall, 67 in the lung) underwent percutaneous interstitial implantation of {sup 125}I radioactive seeds under CT guidance. A treatment planning system (TPS) was employed to calculate the number and distribution of seeds preoperatively. An 18-G needle was inserted into the lesions under CT guidance and send the seeds according to TPS. Two patients with mediastinal lesions undergoing seed implantation received an artificial pneumothorax. One patient with lung carcinoma adjacent to the anterior mediastinum underwent seed implantation through the sternum. Follow-up CT was done every 2 months postoperatively. Results: The procedure was successful in all patients. No major procedure-associated death occurred. The mean duration of follow-up was 19.4 ± 1.3 months (3–49 months). A complete response (CR) was seen in 49 lesions (63.6%), partial response (PR) in 9 lesions (11.7%), stable disease (SD) in 12 lesions (12.8%), and progressive disease (PD) in 7 lesions (7.4%). The overall response rate (CR + PR) was 75.3%; the local control rate (CR + PR + SD) was 90.9%. The 1-, 2- and 3-year progression-free rates for local tumors were 91%, 88% and 88%, respectively. The 1-, 2- and 3-year survival rates were 87%, 74% and 68%, respectively. Conclusion: Implantation of CT-guided {sup 125}I seeds is feasible and effective for patients with malignant thoracic tumors.

Iodine-125 seed implantation for unresectable pancreatic carcinoma guided by intraoperative ultrasound

International Nuclear Information System (INIS)

Wang Junjie; Xiu Dianrong; Ran Weiqiang; Bai Jing; Zhu Lihong; Liu Jiangping

2005-01-01

Objective: To investigate the surgical technique, efficacy and side effects of 125 I seed interstitial implantation for pancreatic carcinoma. Methods: A total of 22 patients with biopsy proven unresectable adenocarcinoma of pancreas were treated with 125 I implants during laparotomy. Of them 11 patients were treated previously by a combination of bypass surgery. The stent was implanted in 2 cases 2 weeks before and 4 weeks after seed implantation. Seed needles were implanted parallelly to each other, with 1-1.5 cm apart. Mick applicator was being connected to each needle to implant seed. The radioactive activity ranged 0.40-0.70 mCi, the matched peripheral doses were 65-145 Gy. The mean number of 125 I seed was 11-78. Five cases received external beam irradiation with 3D-CRT, the doses were 39-70 Gy and 5 patients received 2 cycle of gemcitabine chemotherapy at 1000 mg/m 2 on dl and d8. Results: Pain was completely relieved in 12 cases, partially relieved in 2 cases, and no response was noted in one case, so the response rate was 93.33%. The median time was 2-3 d. Altogethe 27.27% of the cases died from local recurrence of pancreatic carcinoma and 50% from metastasis. The median survival time in these patients was 6 months, with a 2-year survival rate of 9.09%. The seed immigrated to liver in 3 cases. There were no serious side effects such as infection, pancreatitis, pancreatic fistula, etc. Conclusion: Radioactive seed implantation was safe, high local control, minidamage, satisfactory palliation of pain and without significant complications. (authors)

Comparison of Dosimetric and Biologic Effective Dose Parameters for Prostate and Urethra Using 131Cs and 125I for Prostate Permanent Implant Brachytherapy

International Nuclear Information System (INIS)

Sahgal, Arjun; Jabbari, Siavash; Chen, Josephine; Pickett, Barbie; Roach, Mack; Weinberg, Vivian; Hsu, I-C.; Pouliot, Jean

2008-01-01

Purpose: To compare the urethral and prostate absolute and biologic effective doses (BEDs) for 131 Cs and 125 I prostate permanent implant brachytherapy (PPI). Methods and Materials: Eight previously implanted manually planned 125 I PPI patients were replanned manually with 131 Cs, and re-planned using Inverse Planning Simulated Annealing. 131 Cs activity and the prescribed dose (115 Gy) were determined from that recommended by IsoRay. The BED was calculated for the prostate and urethra using an α/β ratio of 2 and was also calculated for the prostate using an α/β ratio of 6 and a urethral α/β ratio of 2. The primary endpoints of this study were the prostate D 90 BED (pD 90 BED) and urethral D 30 BED normalized to the maximal potential prostate D 90 BED (nuD 30 BED). Results: The manual plan comparison (α/β = 2) yielded no significant difference in the prostate D 90 BED (median, 192 Gy 2 for both isotopes). No significant difference was observed for the nuD 30 BED (median, 199 Gy 2 and 202 Gy 2 for 125 I and 131 Cs, respectively). For the inverse planning simulated annealing plan comparisons (α/β 2), the prostate D 90 BED was significantly lower with 131 Cs than with 125 I (median, 177 Gy 2 vs. 187 Gy 2 , respectively; p = 0.01). However, the nuD 30 BED was significantly greater with 131 Cs than with 125 I (median, 192 Gy 2 vs. 189 Gy 2 , respectively; p = 0.01). Both the manual and the inverse planning simulated annealing plans resulted in a significantly lower prostate D 90 BED (p = 0.01) and significantly greater nuD 30 BED for 131 Cs (p = 0.01), compared with 125 I, when the prostate α/β ratio was 6 and the urethral α/β ratio was 2. Conclusion: This report highlights the controversy in comparing the dose to both the prostate and the organs at risk with different radionuclides

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.

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

International Nuclear Information System (INIS)

Genebes, Caroline; Filleron, Thomas; Graff, Pierre; Jonca, Frédéric; Huyghe, Eric; Thoulouzan, Matthieu; Soulie, Michel; Malavaud, Bernard; Aziza, Richard; Brun, Thomas; Delannes, Martine; Bachaud, Jean-Marc

2013-01-01

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

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.

Dosimetric and volumetric criteria for selecting a source activity and a source type (125I or 103Pd) in the presence of irregular seed placement in permanent prostate implants

International Nuclear Information System (INIS)

Wuu, C.-S.; Ennis, Ronald D.; Schiff, Peter B.; Lee, Eva K.; Zaider, Marco

2000-01-01

Purpose: The dosimetric merit of a permanent prostate implant relies on two factors: the quality of the plan itself, and the fidelity of its implementation. The former factor depends on source type and on source strength, while the latter is a combination of skill and experience. The purpose of this study is to offer criteria by which to select a source type ( 125 I or 103 Pd) and activity. Methods and Materials: Given a prescription dose and potential seed positions along needles, treatment plans were designed for a number of seed types and activities, specifically for 125 I with activities ranging from 0.3 to 0.7 mCi, and for 103 Pd with activities in the range of 0.8 to 1.6 mCi. To avoid human planner bias, an automated computerized planning system based on integer programming was used to obtain optimal seed configurations for each seed type and activity. To simulate the effect of seed-placement inaccuracies, random seed-displacement 'errors' were generated for all plans. The displacement errors were assumed to be uniformly distributed within a cube with side equal to 2no. sigmano. The resulting treatment plans were assessed using two volumetric and two dosimetric indices. Results: For 125 I implants a coverage index (CI) of 98.5% or higher can be achieved for all activities (CI is the fraction of the target volume receiving the prescribed or larger dose). The external volume index (EI) (i.e., the amount of healthy tissue, as percentage of the target volume, receiving the prescribed or larger dose) increases from 13.9% to 20% as the activity increases from 0.3 to 0.7 mCi. For implants using 103 Pd, the external volume index increases from 10.2% to 13.9% whenever CI exceeds 98.5%. Volumetric and dosimetric indices (coverage index, external volume index, D90, and D80) are all sensitive to seed displacement, although the activity dependence of these indices is more pronounced for 125 I than for 103 Pd implants. Conclusions: For both isotopes, the lower activities

SU-G-201-02: Application of RayStretch in Clinical Cases: A Calculation for Heterogeneity Corrections in LDR Permanent I-125 Prostate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Hueso-Gonzalez, F [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Dresden (Germany); Vijande, J [University of Valencia, Burjassot and IFIC (CSIC-UV) (Spain); Ballester, F [University of Valencia, Burjassot (Spain); Perez-Calatayud, J [Hospital Clinica Benidorm, Benidorm, and Hospital Universitari i Politecnic La Fe, Valencia (Spain); Siebert, F [Clinic of Radiotherapy (Radiooncology), Kiel (Germany)

2016-06-15

Purpose: Tissue heterogeneities and calcifications have significant impact on the dosimetry of low energy brachytherapy (BT). RayStretch is an analytical algorithm developed in our institution to incorporate heterogeneity corrections in LDR prostate brachytherapy. The aim of this work is to study its application in clinical cases by comparing its predictions with the results obtained with TG-43 and Monte Carlo (MC) simulations. Methods: A clinical implant (71 I-125 seeds, 15 needles) from a real patient was considered. On this patient, different volumes with calcifications were considered. Its properties were evaluated in three ways by i) the Treatment planning system (TPS) (TG-43), ii) a MC study using the Penelope2009 code, and iii) RayStretch. To analyse the performance of RayStretch, calcifications located in the prostate lobules covering 11% of the total prostate volume and larger calcifications located in the lobules and underneath the urethra for a total occupied volume of 30% were considered. Three mass densities (1.05, 1.20, and 1.35 g/cm3) were explored for the calcifications. Therefore, 6 different scenarios ranging from small low density calcifications to large high density ones have been discussed. Results: DVH and D90 results given by RayStretch agree within 1% with the full MC simulations. Although no effort has been done to improve RayStretch numerical performance, its present implementation is able to evaluate a clinical implant in a few seconds to the same level of accuracy as a detailed MC calculation. Conclusion: RayStretch is a robust method for heterogeneity corrections in prostate BT supported on TG-43 data. Its compatibility with commercial TPSs and its high calculation speed makes it feasible for use in clinical settings for improving treatment quality. It will allow in a second phase of this project, its use during intraoperative ultrasound planning. This study was partly supported by a fellowship grant from the Spanish Ministry of

SU-F-T-02: Estimation of Radiobiological Doses (BED and EQD2) of Single Fraction Electronic Brachytherapy That Equivalent to I-125 Eye Plaque: By Using Linear-Quadratic and Universal Survival Curve Models

Energy Technology Data Exchange (ETDEWEB)

Kim, Y; Waldron, T; Pennington, E [University Of Iowa, College of Medicine, Iowa City, IA (United States)

2016-06-15

Purpose: To test the radiobiological impact of hypofractionated choroidal melanoma brachytherapy, we calculated single fraction equivalent doses (SFED) of the tumor that equivalent to 85 Gy of I125-BT for 20 patients. Corresponding organs-at-risks (OARs) doses were estimated. Methods: Twenty patients treated with I125-BT were retrospectively examined. The tumor SFED values were calculated from tumor BED using a conventional linear-quadratic (L-Q) model and an universal survival curve (USC). The opposite retina (α/β = 2.58), macula (2.58), optic disc (1.75), and lens (1.2) were examined. The % doses of OARs over tumor doses were assumed to be the same as for a single fraction delivery. The OAR SFED values were converted into BED and equivalent dose in 2 Gy fraction (EQD2) by using both L-Q and USC models, then compared to I125-BT. Results: The USC-based BED and EQD2 doses of the macula, optic disc, and the lens were on average 118 ± 46% (p < 0.0527), 126 ± 43% (p < 0.0354), and 112 ± 32% (p < 0.0265) higher than those of I125-BT, respectively. The BED and EQD2 doses of the opposite retina were 52 ± 9% lower than I125-BT. The tumor SFED values were 25.2 ± 3.3 Gy and 29.1 ± 2.5 Gy when using USC and LQ models which can be delivered within 1 hour. All BED and EQD2 values using L-Q model were significantly larger when compared to the USC model (p < 0.0274) due to its large single fraction size (> 14 Gy). Conclusion: The estimated single fraction doses were feasible to be delivered within 1 hour using a high dose rate source such as electronic brachytherapy (eBT). However, the estimated OAR doses using eBT were 112 ∼ 118% higher than when using the I125-BT technique. Continued exploration of alternative dose rate or fractionation schedules should be followed.

Radiation exposure after permanent prostate brachytherapy

International Nuclear Information System (INIS)

Cattani, Federica; Vavassori, Andrea; Polo, Alfredo; Rondi, Elena; Cambria, Raffaella; Orecchia, Roberto; Tosi, Giampiero

2006-01-01

Background and purpose: Limited information is available on the true radiation exposure and associated risks for the relatives of the patients submitted to prostate brachytherapy with permanent implant of radioactive sources and for any other people coming into contact with them. In order to provide appropriate information, we analyzed the radiation exposure data from 216 prostate cancer patients who underwent 125 I or 103 Pd implants at the European Institute of Oncology of Milan, Italy. Patients and methods: Between October 1999 and October 2004, 216 patients with low risk prostate carcinoma were treated with 125 I (200 patients) or 103 Pd (16 patients) permanent seed implantation. One day after the procedure, radiation exposure measurements around the patients were performed using an ionization chamber survey meter (Victoreen RPO-50) calibrated in dose rate at an accredited calibration center (calibration Centre SIT 104). Results: The mean dose rate at the posterior skin surface (gluteal region) following 125 I implants was 41.3 μSv/h (range: 6.2-99.4 μSv/h) and following 103 Pd implants was 18.9 μSv/h (range 5.0-37.3 μSv/h). The dose rate at 50 cm from the skin decreased to the mean value of 6.4 μSv/h for the 125 I implants and to the mean value of 1.7 μSv/h for the 103 Pd implants. Total times required to reach the annual dose limit (1 mSv/year) recommended for the general population by the European Directive 96/29/Euratom and by the Italian law (Decreto Legislativo 241/2000) at a distance of 50 cm from the posterior skin surface of the implanted patient would be 7.7 and 21.6 days for 125 I and for 103 Pd. Good correlation between the measured dose rates and both the total implanted activity and the distance between the most posteriorly implanted seed and the skin surface of the patients was found. Conclusions: Our data show that the dose rates at 50 cm away from the prostate brachytherapy patients are very low and that the doses possibly absorbed by the

Prostate-Specific Antigen Bounce After Permanent Iodine-125 Prostate Brachytherapy-An Australian Analysis

International Nuclear Information System (INIS)

Zwahlen, Daniel R.; Smith, Ryan; Andrianopoulos, Nick; Matheson, Bronwyn; Royce, Peter; Millar, Jeremy L.

2011-01-01

Purpose: To report on prostate-specific antigen (PSA) 'bounces' after 125 I prostate brachytherapy to review the relationship to biochemical control and correlate both clinical and dosimetric variables. Methods and Materials: We analyzed 194 hormone-naive patients with a follow-up of ≥3 years. Four bounce definitions were applied: an increase of ≥0.2 ng/mL (definition I), ≥0.4 ng/mL (definition II), ≥15% (definition III), and ≥35% (definition IV) of a previous value with spontaneous return to the prebounce level or lower. Results: Using definition I, II, III, and IV, a bounce was detected in 50%, 34%, 11%, and 9% of patients, respectively. The median time to onset was 14-16 months, the duration was 12-21.5 months, and the magnitude of the increase was 0.5-2 ng/mL. A magnitude of >2 ng/mL, fulfilling the criteria for biochemical failure (BF) according to the American Society for Therapeutic Radiology and Oncology Phoenix definition, was detected in 11.3%, 16.9%, 47.6%, and 50% using definitions I, II, III, and IV, respectively; 11 patients (5.7%) had true BF. The PSA bounces occurred earlier than BF (p < 0.001). The prediction of BF remains controversial and is probably unrelated to biochemical control. The only statistically significant factor predictive of a PSA bounce was younger age (definitions I and II). Conclusion: PSA bounces are common after brachytherapy. All definitions resulted in a high number of false-positive calls for BF during the first 2 years. The definition of an increase of ≥0.2 ng/mL should be preferred because of the lowest number of false-positive results for BF. Patients experiencing a PSA bounce during the first 2 years after brachytherapy should undergo surveillance every 3-6 months. Additional investigations are recommended for elevated postimplant PSA levels that have not corrected by 3 years of follow-up.

A theoretical derivation of the nomograms for permanent prostate brachytherapy

International Nuclear Information System (INIS)

Wang Xiaohong; Potters, Louis

2001-01-01

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=cxd n 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

A study on image reconstruction for seed localization for permanent prostate brachytherapy

International Nuclear Information System (INIS)

Hong, Ju Young; Rah, Jeong Eun; Suh, Tae Suk

2007-01-01

This study was to design and fabricate a phantom for prostate cancer brachytherapy to validate a developed program applying a 3-film technique, and to compare it with the conventional 2-film technique for determining the location of an implanted seed. The images were obtained from overlapped seeds by randomly placing a maximum of 63 seeds in the interior-posterior (AP) position and at -30 .deg. to 30 .deg. at 15 .deg. intervals. Images obtained by use of the phantom were applied to the image processing procedure, and were then processed into the development program for seed localization. In this study, cases were set where one seed overlapped, where two seeds overlapped and where none of the three views resolved all seeds. The distance between the centers of each seed to the reference seed was calculated in a prescribed region. This distance determined the location of each seed in a given band. The location of the overlapped seeds was compared with that of the 2-film technique. With this program, the detection rate was 92.2% (at ± 15 .deg. ), 94.1% (at ± 30 .deg.) and 70.6% (compared to the use of the 2-film technique). The overlaps were caused by one or more than two seeds that overlapped; the developed program can identify the location of each seed perfectly. However, for the third case the program was not able to resolve the overlap of the seeds. This program can be used to improve treatment outcome for the brachytherapy of prostate cancer by reducing the number of errors in the process of reconstructing the locations of perfectly overlapped seeds

Simulation of measurement absorbed dose on prostate brachytherapy with radius of prostate 2 cm using MCNP5 with seed implant model isoaid AdvantageTM IAPd-103A

International Nuclear Information System (INIS)

Poundra Setiawan; Suharyana; Riyatun

2015-01-01

Simulation of measurement absorbed dose on prostate brachytherapy with radius of prostate 2 cm using MCNP5 with seed implant model IsoAid Advantage TM IAPd-103A has been conducted. 103 Pd used as a radioactive source in the seed implant and it has energy gamma emission 20,8 keV with half live 16,9 days and has activity 4 mCi. The prostate cancer is modeled with spherical and it has radius 3 cm, after planting the seed implant 103 Pdover 24,4 days, prostate cancer has absorbed dose 2,172Gy. Lethal dose maximum use 103 Pd is 125 Gy and it was reached with 59 seeds. (author)

Killing effect of EGFR-TKI combined with 125I seed implantation therapy on ⅢB-Ⅳ stage lung cancer tissue

Directory of Open Access Journals (Sweden)

Ai-Sheng Xiang

2016-12-01

Full Text Available Objective: To analyze the killing effect of EGFR-TKI combined with 125I seed implantation therapy on ⅢB-Ⅳ stage lung cancer tissue. Methods: A total of 78 patients with ⅢB-Ⅳ stage lung cancer were randomly divided into observation group and control group (n=39, control group received EGFR-TKI treatment and observation group received EGFR-TKI combined with 125I seed implantation therapy. Differences in apoptosis gene, invasion gene and autophagy gene expression in lung tissue were compared between two groups after 1 month of treatment. Results: Apoptosis genes PDCD5, bax and bcl-xS mRNA expression levels in lung tissue of observation group after 1 month of treatment were higher than those of control group while Bag-1, survivin and bcl-xL mRNA expression levels were lower than those of control group; invasion genes CD147, EGFR and DDX17 mRNA expression levels were lower than those of control group while Bin1, E-cadherin and Ovol2 mRNA expression levels were higher than those of control group; autophagy genes ARHI, Beclin1, Atg5, LC3B, pULK and PI3KC3 mRNA expression levels were higher than those of control group. Conclusions: EGFR-TKI combined with 125I seed implantation therapy can enhance the tumor killing effect on patients with ⅢB-Ⅳ stage lung cancer, and contribute to the optimization of overall condition and the extension of survival time.

WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

International Nuclear Information System (INIS)

Warrell, G; Shvydka, D; Parsai, E I

2016-01-01

Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapy seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that

WE-DE-201-12: Thermal and Dosimetric Properties of a Ferrite-Based Thermo-Brachytherapy Seed

Energy Technology Data Exchange (ETDEWEB)

Warrell, G; Shvydka, D; Parsai, E I [University of Toledo Medical Center, Toledo, OH (United States)

2016-06-15

Purpose: The novel thermo-brachytherapy (TB) seed provides a simple means of adding hyperthermia to LDR prostate permanent implant brachytherapy. The high blood perfusion rate (BPR) within the prostate motivates the use of the ferrite and conductive outer layer design for the seed cores. We describe the results of computational analyses of the thermal properties of this ferrite-based TB seed in modelled patient-specific anatomy, as well as studies of the interseed and scatter (ISA) effect. Methods: The anatomies (including the thermophysical properties of the main tissue types) and seed distributions of 6 prostate patients who had been treated with LDR brachytherapy seeds were modelled in the finite element analysis software COMSOL, using ferrite-based TB and additional hyperthermia-only (HT-only) seeds. The resulting temperature distributions were compared to those computed for patient-specific seed distributions, but in uniform anatomy with a constant blood perfusion rate. The ISA effect was quantified in the Monte Carlo software package MCNP5. Results: Compared with temperature distributions calculated in modelled uniform tissue, temperature distributions in the patient-specific anatomy were higher and more heterogeneous. Moreover, the maximum temperature to the rectal wall was typically ∼1 °C greater for patient-specific anatomy than for uniform anatomy. The ISA effect of the TB and HT-only seeds caused a reduction in D90 similar to that found for previously-investigated NiCu-based seeds, but of a slightly smaller magnitude. Conclusion: The differences between temperature distributions computed for uniform and patient-specific anatomy for ferrite-based seeds are significant enough that heterogeneous anatomy should be considered. Both types of modelling indicate that ferrite-based seeds provide sufficiently high and uniform hyperthermia to the prostate, without excessively heating surrounding tissues. The ISA effect of these seeds is slightly less than that

In vivo dosimetry using a linear Mosfet-array dosimeter to determine the urethra dose in 125I permanent prostate implants.

Science.gov (United States)

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

2009-01-01

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

WE-AB-BRA-11: Improved Imaging of Permanent Prostate Brachytherapy Seed Implants by Combining an Endorectal X-Ray Sensor with a CT Scanner

International Nuclear Information System (INIS)

Steiner, J; Matthews, K; Jia, G

2016-01-01

Purpose: To test feasibility of the use of a digital endorectal x-ray sensor for improved image resolution of permanent brachytherapy seed implants compared to conventional CT. Methods: Two phantoms simulating the male pelvic region were used to test the capabilities of a digital endorectal x-ray sensor for imaging permanent brachytherapy seed implants. Phantom 1 was constructed from acrylic plastic with cavities milled in the locations of the prostate and the rectum. The prostate cavity was filled a Styrofoam plug implanted with 10 training seeds. Phantom 2 was constructed from tissue-equivalent gelatins and contained a prostate phantom implanted with 18 strands of training seeds. For both phantoms, an intraoral digital dental x-ray sensor was placed in the rectum within 2 cm of the seed implants. Scout scans were taken of the phantoms over a limited arc angle using a CT scanner (80 kV, 120–200 mA). The dental sensor was removed from the phantoms and normal helical CT and scout (0 degree) scans using typical parameters for pelvic CT (120 kV, auto-mA) were collected. A shift-and add tomosynthesis algorithm was developed to localize seed plane location normal to detector face. Results: The endorectal sensor produced images with improved resolution compared to CT scans. Seed clusters and individual seed geometry were more discernable using the endorectal sensor. Seed 3D locations, including seeds that were not located in every projection image, were discernable using the shift and add algorithm. Conclusion: This work shows that digital endorectal x-ray sensors are a feasible method for improving imaging of permanent brachytherapy seed implants. Future work will consist of optimizing the tomosynthesis technique to produce higher resolution, lower dose images of 1) permanent brachytherapy seed implants for post-implant dosimetry and 2) fine anatomic details for imaging and managing prostatic disease compared to CT images. Funding: LSU Faculty Start-up Funding

WE-AB-BRA-11: Improved Imaging of Permanent Prostate Brachytherapy Seed Implants by Combining an Endorectal X-Ray Sensor with a CT Scanner

Energy Technology Data Exchange (ETDEWEB)

Steiner, J; Matthews, K; Jia, G [Louisiana State University, Baton Rouge, LA (United States)

2016-06-15

Purpose: To test feasibility of the use of a digital endorectal x-ray sensor for improved image resolution of permanent brachytherapy seed implants compared to conventional CT. Methods: Two phantoms simulating the male pelvic region were used to test the capabilities of a digital endorectal x-ray sensor for imaging permanent brachytherapy seed implants. Phantom 1 was constructed from acrylic plastic with cavities milled in the locations of the prostate and the rectum. The prostate cavity was filled a Styrofoam plug implanted with 10 training seeds. Phantom 2 was constructed from tissue-equivalent gelatins and contained a prostate phantom implanted with 18 strands of training seeds. For both phantoms, an intraoral digital dental x-ray sensor was placed in the rectum within 2 cm of the seed implants. Scout scans were taken of the phantoms over a limited arc angle using a CT scanner (80 kV, 120–200 mA). The dental sensor was removed from the phantoms and normal helical CT and scout (0 degree) scans using typical parameters for pelvic CT (120 kV, auto-mA) were collected. A shift-and add tomosynthesis algorithm was developed to localize seed plane location normal to detector face. Results: The endorectal sensor produced images with improved resolution compared to CT scans. Seed clusters and individual seed geometry were more discernable using the endorectal sensor. Seed 3D locations, including seeds that were not located in every projection image, were discernable using the shift and add algorithm. Conclusion: This work shows that digital endorectal x-ray sensors are a feasible method for improving imaging of permanent brachytherapy seed implants. Future work will consist of optimizing the tomosynthesis technique to produce higher resolution, lower dose images of 1) permanent brachytherapy seed implants for post-implant dosimetry and 2) fine anatomic details for imaging and managing prostatic disease compared to CT images. Funding: LSU Faculty Start-up Funding

1251 seed calibration using afterloading equipment SeedSelectron. Practical solution to meet the recommendations of the AAPM

International Nuclear Information System (INIS)

Perez-Calatayud, J.; Richart, J.; Perez-Garcia, J.; Guirado, D.; Ballester, F.; Rodriguez, S.; Santos, M.; Depiaggio, M.; Carmona, V.; Lliso, F.; Camacho, C.; Pujades, M. C.

2011-01-01

SeedSelectron is a system used in the afterloader permanent implant brachytherapy seeds 1-125 interstitial prostate. Two aspects are critical when you can meet the recommendations of the AAPM: a practical difficulty to check the quantity of seed required, and the great uncertainty of all measured diodes. The purpose of this paper is to present a practical solution that has been adopted to implement the recommendations of the AAPM

Automatic seed picking for brachytherapy postimplant validation with 3D CT images.

Science.gov (United States)

Zhang, Guobin; Sun, Qiyuan; Jiang, Shan; Yang, Zhiyong; Ma, Xiaodong; Jiang, Haisong

2017-11-01

Postimplant validation is an indispensable part in the brachytherapy technique. It provides the necessary feedback to ensure the quality of operation. The ability to pick implanted seed relates directly to the accuracy of validation. To address it, an automatic approach is proposed for picking implanted brachytherapy seeds in 3D CT images. In order to pick seed configuration (location and orientation) efficiently, the approach starts with the segmentation of seed from CT images using a thresholding filter which based on gray-level histogram. Through the process of filtering and denoising, the touching seed and single seed are classified. The true novelty of this approach is found in the application of the canny edge detection and improved concave points matching algorithm to separate touching seeds. Through the computation of image moments, the seed configuration can be determined efficiently. Finally, two different experiments are designed to verify the performance of the proposed approach: (1) physical phantom with 60 model seeds, and (2) patient data with 16 cases. Through assessment of validated results by a medical physicist, the proposed method exhibited promising results. Experiment on phantom demonstrates that the error of seed location and orientation is within ([Formula: see text]) mm and ([Formula: see text])[Formula: see text], respectively. In addition, the most seed location and orientation error is controlled within 0.8 mm and 3.5[Formula: see text] in all cases, respectively. The average process time of seed picking is 8.7 s per 100 seeds. In this paper, an automatic, efficient and robust approach, performed on CT images, is proposed to determine the implanted seed location as well as orientation in a 3D workspace. Through the experiments with phantom and patient data, this approach also successfully exhibits good performance.

Monte Carlo-aided dosimetry of the new Bebig IsoSeed registered 103Pd Interstitial Brachytherapy Seed

International Nuclear Information System (INIS)

Daskalov, George M.; Williamson, J.F.

2001-01-01

A new model 103 Pd interstitial brachytherapy source, the IsoSeed registered 103 Pd, was recently introduced by Bebig Isotopentechnik und Umweltdiagnostik GmbH for permanent implant applications. This study presents the first quantitative theoretical study of the seed's dosimetric quantities. Monte Carlo photon transport (MCPT) simulation techniques have been used to evaluate the dose-rate distributions around the model IsoSeed registered 103 Pd source in liquid water and air phantoms. These results have been used to calculate and tabulate the anisotropy function, F(r,θ), radial dose function, g(r), and anisotropy factors, φ(r), and dose-rate constant as defined by AAPM Task Group 43 (TG-43) Report. Cartesian 'away' and 'along' tables, giving the dose rates per unit air-kerma strength in water in the range 0.1-3 cm distance around the seed have also been tabulated. The dose-rate constant, Λ, was evaluated by simulating the wide-angle, free-air chamber (WAFAC) calibration geometry recently implemented by NIST (National Institute of Standards and Technology) to realize the primary standard of air-kerma strength (S K,N99 ) for low-energy photon-emitting brachytherapy sources. The dose-rate constant has been found to be Λ=0.660±0.017 in units of dose-rate per unit air-kerma strength (cGy·h-1·U-1)

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.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Experimental radiotherapy of the R1H rhabdomyosarcoma of the rat: combined use of interstitial iodine-125-brachytherapy and fractionated X-irradiation

International Nuclear Information System (INIS)

Doll, D.

1995-01-01

The study described here investigated into the therapeutic effects that split-dose x-radiation combined with interstitial iodine-125 brachytherapy would have on two different lines of the R1H rhabdomyosarcoma of the rat. The following parameters were examined: local tumour control rate; growth delay; net growth delay; position, movement and loss of seeds; tumour shape. The following results were obtained: The local tumour control rate for tumours externally treated with two seeds was by 42 Gy higher than that determined for the group treated with external irradiation alone. A procedure was developed to calculate the most appropriate distance for the seeds on the basis of tumour axes and volumes. The relationship between growth delay and mean maximum distance of the seed from the tumour margin could be ascertained on a quantitative basis. The influence of the tumour shape on the result of treatment was confirmed. Although the seeds were still active at the time of recidivation and treatment was not yet terminated, it was possible to show that the tumour bed effect, which tends to distort the growth delay calculations and may even occur in externally treated seed animals, could largely be avoided in the evaluation of this study. (orig./MG) [de

Optimization of 125I ophthalmic plaque brachytherapy

International Nuclear Information System (INIS)

Astrahan, M.A.; Luxton, G.; Jozsef, G.; Liggett, P.E.; Petrovich, Z.

1990-01-01

Episcleral plaques containing 125 I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged

Effect of edema, relative biological effectiveness, and dose heterogeneity on prostate brachytherapy

International Nuclear Information System (INIS)

Wang, Jian Z.; Mayr, Nina A.; Nag, Subir; Montebello, Joseph; Gupta, Nilendu; Samsami, Nina; Kanellitsas, Christos

2006-01-01

Many factors influence response in low-dose-rate (LDR) brachytherapy of prostate cancer. Among them, edema, relative biological effectiveness (RBE), and dose heterogeneity have not been fully modeled previously. In this work, the generalized linear-quadratic (LQ) model, extended to account for the effects of edema, RBE, and dose heterogeneity, was used to assess these factors and their combination effect. Published clinical data have shown that prostate edema after seed implant has a magnitude (ratio of post- to preimplant volume) of 1.3-2.0 and resolves exponentially with a half-life of 4-25 days over the duration of the implant dose delivery. Based on these parameters and a representative dose-volume histogram (DVH), we investigated the influence of edema on the implant dose distribution. The LQ parameters (α=0.15 Gy -1 and α/β=3.1 Gy) determined in earlier studies were used to calculate the equivalent uniform dose in 2 Gy fractions (EUD 2 ) with respect to three effects: edema, RBE, and dose heterogeneity for 125 I and 103 Pd implants. The EUD 2 analysis shows a negative effect of edema and dose heterogeneity on tumor cell killing because the prostate edema degrades the dose coverage to tumor target. For the representative DVH, the V 100 (volume covered by 100% of prescription dose) decreases from 93% to 91% and 86%, and the D 90 (dose covering 90% of target volume) decrease from 107% to 102% and 94% of prescription dose for 125 I and 103 Pd implants, respectively. Conversely, the RBE effect of LDR brachytherapy [versus external-beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy] enhances dose effect on tumor cell kill. In order to balance the negative effects of edema and dose heterogeneity, the RBE of prostate brachytherapy was determined to be approximately 1.2-1.4 for 125 I and 1.3-1.6 for 103 Pd implants. These RBE values are consistent with the RBE data published in the literature. These results may explain why in earlier modeling studies

Iodine-125 brachytherapy as upfront and salvage treatment for brain metastases. A comparative analysis

Energy Technology Data Exchange (ETDEWEB)

Romagna, Alexander; Schwartz, Christoph; Tonn, Joerg-Christian; Kreth, Friedrich-Wilhelm [Ludwig-Maximilians-University, Department of Neurosurgery, Munich (Germany); Egensperger, Rupert [Ludwig-Maximilians-University, Center for Neuropathology and Prion Research, Munich (Germany); Watson, Juliana; Belka, Claus; Nachbichler, Silke Birgit [Ludwig-Maximilians-University, Department of Radiation-Oncology, Munich (Germany)

2016-11-15

stereotaktischer Rebestrahlungsstrategien zerebraler Metastasen sind kaum publiziert worden. Wir verglichen Risiko-Effizienz-Profile der Jod-125 Brachytherapie (SBT) als Primaertherapie kleiner Metastasen und als Rezidivtherapie nach vorausgegangener Bestrahlung. Voraussetzung fuer eine SBT war immer eine histologische Sicherung der Diagnose. Dieses einheitliche Vorgehen erlaubte, zusaetzlich den Stellenwert bioptischer Verfahren zu analysieren. Patienten mit kleinen unbehandelten (n = 20) oder vorbestrahlen (n = 28) metastasensuspekten Laesionen wurden konsekutiv eingeschlossen. Implantiert wurden temporaere Jod-125-Seeds (mediane Referenzdosis: 50 Gy, mediane Energiedosisleistung: 15 cGy/h). Fuer Risikoanalysen berechneten wir die kumulative biologische effektive Dosis (BED). Die Klassifikation der Neurotoxizitaet erfolgte entsprechend den Kriterien der RTOG/EORTC (Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer). SBT als Initialtherapie wurde bei 20 Patienten und als Rezidivtherapie bei 23 Patienten durchgefuehrt. Fuenf Patienten der Rezidivgruppe wiesen radiogene Gewebsveraenderungen auf, sodass keine Behandlung erfolgte. Patienten mit Primaer- und Rezidivtherapie waren bezueglich ihrer klinischen Parameter mit Ausnahme des Tumorvolumens vergleichbar (geringfuegig kleinere Tumoren in der Rezidivgruppe). Die lokale/distante Einjahrestumorkontrollrate nach Primaer- und Rezidiv-SBT war aehnlich (94 %/64 % vs. 87 %/57 %, p = 0,45). Eine Toxizitaet vom Grad I/II fand sich bei 2 Patienten (kumulative BED: 192,1 Gy{sub 3} und 249,6 Gy{sub 3}). SBT verbindet diagnostische Genauigkeit mit effektiver Behandlung. Die niedrige Toxizitaetsrate unterstreicht die protektiven radiobiologischen Eigenschaften kontinuierlicher Bestrahlung mit niedriger Energiedosisleistung. SBT als Primaer- und Rezidivtherapie ist sicher und effektiv. Die Indikation zur histologischen Reevaluation sollte nach vorausgegangener Bestrahlung immer erwogen werden, um Unter

Study and methodologies for fixing epoxy resin in radioactive sources used for brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Bruna T.; Rostelato, Maria E.C.M.; Souza, Carla D.; Tozetti, Cíntia A.; Zeituni, Carlos A.; Nogueira, Beatriz R.; Silva, José T.; Júnior, Dib K.; Fernandes, Vagner; Souza, Raquel V.; Abreu, Rodrigo T., E-mail: bteigarodrigues@gmail.com, E-mail: elisaros@ipen.br, E-mail: carladdsouza@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil)

2017-07-01

The World Health Organization (WHO) estimates that the number of new cancer cases worldwide will reach 15 million by 2020. The disease is already the second leading cause of death worldwide, being behind only cardiovascular disease. It is unquestionable that it is a public health problem, especially among developing countries. Prostate cancer is the most common among men, approximately 28.6%. The choice of type of treatment for prostate cancer should consider several factors such as: tumor size and extent, apparent aggressiveness (pathological characteristics), age, health. Among the methods applied, brachytherapy has been used in the initial and intermediate stages of the disease. Brachytherapy is a safe and effective treatment for localized prostate cancer. Brachytherapy is a form of radiotherapy in which radioactive seeds are placed in contact with or within the organ being treated. This technique allows a large dose of radiation to be released only on the target tumor that protects healthy surrounding tissues. Sources may have different shapes and sizes, but the one used for prostate cancer is usually 4.5 mm in length and 0.8 mm in diameter. About 80 to 120 seeds can be used per patient. Iodine-125 is the radioisotope most used in brachytherapy of the prostate, it emits 35,49keV X-rays in 100% of the decays, with average energy of 29 keV. The treatment of prostate cancer with permanent implantation of iodine-125 seeds has grown dramatically in the world in recent years. Most patients can return to normal life within three days with little or no pain. (author)

Study and methodologies for fixing epoxy resin in radioactive sources used for brachytherapy

International Nuclear Information System (INIS)

Rodrigues, Bruna T.; Rostelato, Maria E.C.M.; Souza, Carla D.; Tozetti, Cíntia A.; Zeituni, Carlos A.; Nogueira, Beatriz R.; Silva, José T.; Júnior, Dib K.; Fernandes, Vagner; Souza, Raquel V.; Abreu, Rodrigo T.

2017-01-01

The World Health Organization (WHO) estimates that the number of new cancer cases worldwide will reach 15 million by 2020. The disease is already the second leading cause of death worldwide, being behind only cardiovascular disease. It is unquestionable that it is a public health problem, especially among developing countries. Prostate cancer is the most common among men, approximately 28.6%. The choice of type of treatment for prostate cancer should consider several factors such as: tumor size and extent, apparent aggressiveness (pathological characteristics), age, health. Among the methods applied, brachytherapy has been used in the initial and intermediate stages of the disease. Brachytherapy is a safe and effective treatment for localized prostate cancer. Brachytherapy is a form of radiotherapy in which radioactive seeds are placed in contact with or within the organ being treated. This technique allows a large dose of radiation to be released only on the target tumor that protects healthy surrounding tissues. Sources may have different shapes and sizes, but the one used for prostate cancer is usually 4.5 mm in length and 0.8 mm in diameter. About 80 to 120 seeds can be used per patient. Iodine-125 is the radioisotope most used in brachytherapy of the prostate, it emits 35,49keV X-rays in 100% of the decays, with average energy of 29 keV. The treatment of prostate cancer with permanent implantation of iodine-125 seeds has grown dramatically in the world in recent years. Most patients can return to normal life within three days with little or no pain. (author)

On the feasibility of polyurethane based 3D dosimeters with optical CT for dosimetric verification of low energy photon brachytherapy seeds

Energy Technology Data Exchange (ETDEWEB)

Adamson, Justus, E-mail: justus.adamson@duke.edu; Yang, Yun; Juang, Titania; Chisholm, Kelsey; Rankine, Leith; Yin, Fang Fang; Oldham, Mark [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Adamovics, John [Department of Chemistry, Rider University, Lawrenceville, New Jersey 08648 (United States)

2014-07-15

Purpose: To investigate the feasibility of and challenges yet to be addressed to measure dose from low energy (effective energy <50 keV) brachytherapy sources (Pd-103, Cs-131, and I-125) using polyurethane based 3D dosimeters with optical CT. Methods: The authors' evaluation used the following sources: models 200 (Pd-103), CS-1 Rev2 (Cs-131), and 6711 (I-125). The authors used the Monte Carlo radiation transport code MCNP5, simulations with the ScanSim optical tomography simulation software, and experimental measurements with PRESAGE{sup ®} dosimeters/optical CT to investigate the following: (1) the water equivalency of conventional (density = 1.065 g/cm{sup 3}) and deformable (density = 1.02 g/cm{sup 3}) formulations of polyurethane dosimeters, (2) the scatter conditions necessary to achieve accurate dosimetry for low energy photon seeds, (3) the change in photon energy spectrum within the dosimeter as a function of distance from the source in order to determine potential energy sensitivity effects, (4) the optimal delivered dose to balance optical transmission (per projection) with signal to noise ratio in the reconstructed dose distribution, and (5) the magnitude and characteristics of artifacts due to the presence of a channel in the dosimeter. Monte Carlo simulations were performed using both conventional and deformable dosimeter formulations. For verification, 2.8 Gy at 1 cm was delivered in 92 h using an I-125 source to a PRESAGE{sup ®} dosimeter with conventional formulation and a central channel with 0.0425 cm radius for source placement. The dose distribution was reconstructed with 0.02 and 0.04 cm{sup 3} voxel size using the Duke midsized optical CT scanner (DMOS). Results: While the conventional formulation overattenuates dose from all three sources compared to water, the current deformable formulation has nearly water equivalent attenuation properties for Cs-131 and I-125, while underattenuating for Pd-103. The energy spectrum of each source is

Photon energy-fluence correction factor in low energy brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Antunes, Paula C.G.; Yoriyaz, Hélio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo, E-mail: pacrisguian@gmail.com [Department of Atomic, Molecular, and Nuclear Physics and Instituto de Física Corpuscular (UV-CSIC), University of Valencia (Spain)

2017-07-01

The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D{sub tis}) and dose-to-water (D{sub w}). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the {sup 125}I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

Photon energy-fluence correction factor in low energy brachytherapy

International Nuclear Information System (INIS)

Antunes, Paula C.G.; Yoriyaz, Hélio; Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo

2017-01-01

The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D tis ) and dose-to-water (D w ). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the 125 I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

Evaluation of permanent I-125 prostate implants using radiographs and MRI

International Nuclear Information System (INIS)

Moerland, M.A.; Beersma, R.; Bhagwandien, R.; Wijrdeman, H.K.; Battermann, J.J.

1995-01-01

Introduction: Localized prostatic cancer is managed by radical prostatectomy, external beam irradiation or a permanent implant with I-125 seeds. Permanent implants are indicated for small tumours (T1-T2) with a well to moderate histological differentiation. The technique used is a transrectal ultrasound guided transperineal implantation technique, which aims for a seed and dose distribution such that the initial doserate line of 7.8 cGy/h encompasses the prostate resulting in an accumulated dose of 160 Gy. Up till now the seed and dose distribution is evaluated from isocentric radiographs, which do not show the relation with the prostate. Objectives: The aim of this study is the development of a technique to reconstruct and evaluate the seed and dose distribution within the prostate. Methods: Twenty patients underwent radiography on the simulator and scanning on a whole body NMR system within 3 days after implantation of the I-125 seeds. Isocentric radiographs were used for reconstruction of the seed distribution, after which registration with the MR images provided the seed positions in relation to the prostate. Volume dose histograms were used to evaluate the implants. Results: The I-125 seeds and the prostate anatomy were well depicted on T1-weighted spin echo images with minimal read out gradient strength. To date, ten implants were evaluated. According to our method, the prostate volumes receiving the prescribed dose of 160 Gy ranged from 30 to 70% of the total prostate volumes. Conclusion: The combination of isocentric radiographs and MRI enables reconstruction of the seed and dose distribution in relation to the prostate and the computation of dose volume histograms, which may be of value in the evaluation of implant quality

Spectroscopic characterization of low dose rate brachytherapy sources

Science.gov (United States)

Beach, Stephen M.

The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

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

Energy Technology Data Exchange (ETDEWEB)

Landry, Guillaume; Reniers, Brigitte; Murrer, Lars; Lutgens, Ludy; Bloemen-Van Gurp, Esther; Pignol, Jean-Philippe; Keller, Brian; Beaulieu, Luc; Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie, de l' Universite Laval, CHUQ, Pavillon L' Hotel-Dieu de Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, 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 Medical Physics Unit, McGill University, Montreal General Hospital, Montreal, Quebec H3G 1A4 (Canada)

2010-10-15

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: {sup 125}I, {sup 103}Pd, {sup 131}Cs, 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 D{sub w,m} as opposed to dose to a small mass of medium in medium D{sub m,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 {sup 125}I 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 D{sub 90} values. (3) Dose calculations for four clinical breast LDR brachytherapy permanent seed implants using {sup 103}Pd 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 D{sub 90} 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

The difference of scoring dose to water or tissues in Monte Carlo dose calculations for low energy brachytherapy photon sources.

Science.gov (United States)

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

2011-03-01

The goal of this work is to compare D(m,m) (radiation transported in medium; dose scored in medium) and D(w,m) (radiation transported in medium; dose scored in water) obtained from Monte Carlo (MC) simulations for a subset of human tissues of interest in low energy photon brachytherapy. Using low dose rate seeds and an electronic brachytherapy source (EBS), the authors quantify the large cavity theory conversion factors required. The authors also assess whether ap plying large cavity theory utilizing the sources' initial photon spectra and average photon energy induces errors related to spatial spectral variations. First, ideal spherical geometries were investigated, followed by clinical brachytherapy LDR seed implants for breast and prostate cancer patients. Two types of dose calculations are performed with the GEANT4 MC code. (1) For several human tissues, dose profiles are obtained in spherical geometries centered on four types of low energy brachytherapy sources: 125I, 103Pd, and 131Cs seeds, as well as an EBS operating at 50 kV. Ratios of D(w,m) over D(m,m) are evaluated in the 0-6 cm range. In addition to mean tissue composition, compositions corresponding to one standard deviation from the mean are also studied. (2) Four clinical breast (using 103Pd) and prostate (using 125I) brachytherapy seed implants are considered. MC dose calculations are performed based on postimplant CT scans using prostate and breast tissue compositions. PTV D90 values are compared for D(w,m) and D(m,m). (1) Differences (D(w,m)/D(m,m)-1) of -3% to 70% are observed for the investigated tissues. For a given tissue, D(w,m)/D(m,m) is similar for all sources within 4% and does not vary more than 2% with distance due to very moderate spectral shifts. Variations of tissue composition about the assumed mean composition influence the conversion factors up to 38%. (2) The ratio of D90(w,m) over D90(m,m) for clinical implants matches D(w,m)/D(m,m) at 1 cm from the single point sources, Given

Prospective evaluation of quality of life after permanent prostate brachytherapy with I-125: Importance of baseline symptoms and of prostate-V150

International Nuclear Information System (INIS)

Vordermark, Dirk; Noe, Michael; Markert, Klaus; Wulf, Joern; Mueller, Gerd; Bratengeier, Klaus; Beckmann, Gabriele; Baier, Fabian; Guckenberger, Matthias; Schiefelbein, Frank; Schoen, Georg; Flentje, Michael; Baier, Kurt

2009-01-01

Background and purpose: Detailed knowledge of quality of life (QoL) after permanent I-125 brachytherapy may aid in counselling patients with early-stage prostate cancer. Materials and methods: Seventy-four consecutive patients with low-risk prostate cancer were asked to complete the EORTC QLQ-C30 questionnaire with the prostate-specific PR25 module before implant, four weeks and one year after implant (response rates 97%, 88% and 89%, respectively). Implant characteristics were correlated with QoL scores. Results: Global QoL was stable from pre-treatment to one year after implant and similar to age-adjusted scores of healthy controls. Significant changes versus baseline in QLQ-C30 domains were worsened social function at four weeks, increased constipation at four weeks and at one year and improved emotional function at one year. PR25 urinary symptoms were significantly increased at four weeks and, despite some improvement, at one year; bowel symptoms were slightly increased. Both types of symptoms were most strongly related with pre-treatment symptom scores. Prostate-V150 was the only implant parameter significantly associated with both urinary and bowel symptoms at four weeks and one year. Conclusions: Limiting the high-dose subvolume in the prostate may be beneficial to reduce urinary and bowel symptoms but the major determinant of symptoms after I-125 implant is the baseline symptom level.

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.

Optimal matching for prostate brachytherapy seed localization with dimension reduction.

Science.gov (United States)

Lee, Junghoon; Labat, Christian; Jain, Ameet K; Song, Danny Y; Burdette, Everette C; Fichtinger, Gabor; Prince, Jerry L

2009-01-01

In prostate brachytherapy, x-ray fluoroscopy has been used for intra-operative dosimetry to provide qualitative assessment of implant quality. More recent developments have made possible 3D localization of the implanted radioactive seeds. This is usually modeled as an assignment problem and solved by resolving the correspondence of seeds. It is, however, NP-hard, and the problem is even harder in practice due to the significant number of hidden seeds. In this paper, we propose an algorithm that can find an optimal solution from multiple projection images with hidden seeds. It solves an equivalent problem with reduced dimensional complexity, thus allowing us to find an optimal solution in polynomial time. Simulation results show the robustness of the algorithm. It was validated on 5 phantom and 18 patient datasets, successfully localizing the seeds with detection rate of > or = 97.6% and reconstruction error of < or = 1.2 mm. This is considered to be clinically excellent performance.

Tumor therapy with 125I-octreotide and 125I-UdR

International Nuclear Information System (INIS)

Fan, W.; Zhu, R.; Yang, C.; Sun, J.J.; Xu, Y.J.; Zhang, Y.J.; Wu, M.J.; Wang, D.J.

2005-01-01

Purpose: To determine the tumor cell damage effect with Auger-electron emitter 125 I in different chemical states. Methods: (1) [Tyr 3 ] octreotide (TOC) and UdR are labeled with 125 I,respectively. (2) Receptor analysis of 125 I-TOC on small cell lung cancer (SCLC) NCI-H446 cell lines is performed comparing with normal lymph cells. NCI-H446 cells added various dose of 125 I-TOC are incubated for different time with 125 I-Nal and non-labeled TOC as control. The capacity of NCI-H446 cell lines bound and internalization of 125 I TOC are determined. The radiation damage of tumor cells is measured by MTF methods. (3) The killing effects of 125 I-UdR in human pancreatic cancer cell line Bax-Pc and Sca-BER bladder carcinoma cells are evaluated with the similar methods. I-UdR penetrating into the Sca-BER cell nucleus is observed with confocal microscope. The grow suppression and clonogenic formation of Sca-BER cells after incubation with 125 I-UdR are analyzed. Proliferation fraction and S phase cell fraction of Sca-BER cell added 125 I-UdR is measured with flow cytometric analysis. Results: (1) Kd=(0.56∼2.0) x 10 -11 mol/L and B max =(1.17∼2.0) x 10 5 cell site are obtained by receptor analysis of 125 I-TOC on NCI-H446 cells. Comparatively, the difference between total binding and non-specific binding is low and there is no saturation of specific binding for normal lymphocyte. About 50% of 125 I-TOC is internalized into the NCI-H446 cell nucleus at 24h after incubation. The damige of NCI-H446 cells by 125 I-TOC is clearly observed. (2) The penetration amount of 125 I-UdR into cell nucleus increases with the incubate time when the concentration of 125 I-UdR is in the range of 10∼500 kBq/mL and reaches the peak fraction of 94% at 36 h after incubation. The radioactivity of 125 I-UdR is then achieved equelibration and no more increased with time. The linear correlation with γ=0.867∼0.978 between the concentration of 125 I-UdR in cell nucleus and the incubation time

Permanent I-125 interstitial implant in the management of high grade CNS malignancies in children

International Nuclear Information System (INIS)

Vaishampayan, N.; Zamorano, L.; Aronin, P.; Gaspar, L.; Canady, A.; Lattin, P.; Ezzell, G.; Yakar, D.; Chungbin, S.; Fontanesi, J.

1996-01-01

Purpose/Objective: To evaluate the efficacy and complications associated with the use of permanent I-125 interstitial implants in children with high grade CNS malignancies. Materials and Methods: Between May of 1990 and September of 1994, fourteen children received permanent I-125 interstitial implant brachytherapy as initial therapy (n=8) or at time of recurrence (n=6). Histologies included Glioblastoma Multiforme (n=2), Anaplastic Astrocytoma (n=9) and others (n=3). Pre-implant surgical procedures included: Gross Total Resection (n=2), Subtotal Resection (n=8) or Biopsy alone (n=4). Six patients received pre-implant external beam irradiation (dose range 3,500-6500 cGy) and three patients received post-implant external beam irradiation (dose range 5,040-5,060 cGy). Implant dose range was 8,294-10,368 cGy over the lifetime of the implant (median 10,368 cGy). Results: At last follow-up (median 17.5 months; range 4-56 months), eight children were alive. Six out of the eight had no evidence of disease progression while the remaining had radiologic evidence of progression. Implant complications (n=2) included skin necrosis and bone flap infection. Conclusions: Based on this initial review, we continue to investigate the use of permanent I-125 interstitial brachytherapy in the treatment of high grade CNS malignancies in children and will discuss and compare these results with those of other 'Boost' series

Seed Placement in Permanent Breast Seed Implant Brachytherapy: Are Concerns Over Accuracy Valid?

Energy Technology Data Exchange (ETDEWEB)

Morton, Daniel, E-mail: dmorton@bccancer.bc.ca [Department of Medical Physics, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia (Canada); Hilts, Michelle [Department of Medical Physics, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia (Canada); Batchelar, Deidre [Department of Medical Physics, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada); Crook, Juanita [Department of Radiation Oncology, BC Cancer Agency, Centre for the Southern Interior, Kelowna, British Columbia (Canada)

2016-07-01

Purpose: To evaluate seed placement accuracy in permanent breast seed implant brachytherapy (PBSI), to identify any systematic errors and evaluate their effect on dosimetry. Methods and Materials: Treatment plans and postimplant computed tomography scans for 20 PBSI patients were spatially registered and used to evaluate differences between planned and implanted seed positions, termed seed displacements. For each patient, the mean total and directional seed displacements were determined in both standard room coordinates and in needle coordinates relative to needle insertion angle. Seeds were labeled according to their proximity to the anatomy within the breast, to evaluate the influence of anatomic regions on seed placement. Dosimetry within an evaluative target volume (seroma + 5 mm), skin, breast, and ribs was evaluated to determine the impact of seed placement on the treatment. Results: The overall mean (±SD) difference between implanted and planned positions was 9 ± 5 mm for the aggregate seed population. No significant systematic directional displacements were observed for this whole population. However, for individual patients, systematic displacements were observed, implying that intrapatient offsets occur during the procedure. Mean displacements for seeds in the different anatomic areas were not found to be significantly different from the mean for the entire seed population. However, small directional trends were observed within the anatomy, potentially indicating some bias in the delivery. Despite observed differences between the planned and implanted seed positions, the median (range) V{sub 90} for the 20 patients was 97% (66%-100%), and acceptable dosimetry was achieved for critical structures. Conclusions: No significant trends or systematic errors were observed in the placement of seeds in PBSI, including seeds implanted directly into the seroma. Recorded seed displacements may be related to intrapatient setup adjustments. Despite observed seed

The use of anisotropic data in 125I prostate implants

International Nuclear Information System (INIS)

Fox, R.A.; Haworth, A.; Mina, L.L.

1997-01-01

The report recently published by the American Association of Physicists in Medicine (AAPM) Task Group 43 (TG43) recommends the use of a two dimensional dose distribution function for the dosimetry associated with 125 I, 192 Ir and 103 Pd sources. For commercial planning systems that cannot be readily adapted to use a two dimensional function, a point source approximation is provided. The dose distribution around an array of 125 I seeds has been calculated using the two dimensional model and the point source approximation. Isodose distributions through selected planes and dose volume histograms of selected cubic volumes show that differences between the two models for this array are insignificant, particularly in view of the uncertainties associated with using the data which is provided by TG43 for the two dimensional anisotropy function and that it should be retained for planning prostrate treatments with 125 I seeds. It is recommended that each application must be examined separately to establish the extent to which an isotropic dose distribution is applicable

Short-lag spatial coherence beamforming of photoacoustic images for enhanced visualization of prostate brachytherapy seeds

OpenAIRE

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

2013-01-01

Prostate brachytherapy, administered by implanting tiny radioactive seeds to treat prostate cancer, currently relies on transrectal ultrasound imaging for intraoperative visualization of the metallic seeds. Photoacoustic (PA) imaging has been suggested as a feasible alternative to ultrasound imaging due to its superior sensitivity to metal surrounded by tissue. However, PA images suffer from poor contrast when seeds are distant from the light source. We propose a transperineal light delivery ...

The side effects and complications of percutaneous iodine-125 seeds implantation under CT-guide for patients with advanced pancreatic cancer.

Science.gov (United States)

Lv, Wei-Fu; Lu, Dong; Xiao, Jing-Kun; Mukhiya, Gauri; Tan, Zhong-Xiao; Cheng, De-Lei; Zhou, Chun-Ze; Zhang, Xing-Min; Zhang, Zheng-Feng; Hou, Chang-Long

2017-12-01

The present study investigates the side effects and complications of computed tomography (CT)-guided percutaneous iodine-125 (I-125) seeds implantation for advanced pancreatic cancer. The clinical data were retrospectively analyzed for patients treated with implantation of I-125 seeds under CT-guide in our hospital from May 2010 to April 2015. The side effects and complications were collected and their possible reasons were analyzed. A total of 78 patients were enrolled. The side effects were categorized as fever in 29 cases (37.18%), abdominal pain in 26 cases (33.33%), nausea and vomiting in 9 cases (11.54%), diarrhea in 5 cases (6.41%), and constipation in 4 cases (5.13%). Complications were composed of pancreatitis in 9 cases (11.54%), infection in 5 cases (6.41%), seed migration in 2 cases (2.56%), intestinal perforation in 1 case (1.28%), and intestinal obstruction in 1 case. The incidence of complication was 23.08% (18/78). The difference in incidence of complication was statistically significant between patients implanted with ≤27 seeds and those with >27 seeds (P = .032). The side effects and complications frequently occur in implantation of I-125 seeds for patients with advanced pancreatic cancer. More concern should be given to the patients treated by this technique. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Fifteen-Year Biochemical Relapse-Free Survival, Cause-Specific Survival, and Overall Survival Following I125 Prostate Brachytherapy in Clinically Localized Prostate Cancer: Seattle Experience

International Nuclear Information System (INIS)

Sylvester, John E.; Grimm, Peter D.; Wong, Jason; Galbreath, Robert W.; Merrick, Gregory; Blasko, John C.

2011-01-01

Purpose: To report 15-year biochemical relapse-free survival (BRFS), cause-specific survival (CSS), and overall survival (OS) outcomes of patients treated with I 125 brachytherapy monotherapy for clinically localized prostate cancer early in the Seattle experience. Methods and Materials: Two hundred fifteen patients with clinically localized prostate cancer were consecutively treated from 1988 to 1992 with I 125 monotherapy. They were prospectively followed as a tight cohort. They were evaluated for BRFS, CSS, and OS. Multivariate analysis was used to evaluate outcomes by pretreatment clinical prognostic factors. BRFS was analyzed by the Phoenix (nadir + 2 ng/mL) definition. CSS and OS were evaluated by chart review, death certificates, and referring physician follow-up notes. Gleason scoring was performed by general pathologists at a community hospital in Seattle. Time to biochemical failure (BF) was calculated and compared by Kaplan-Meier plots. Results: Fifteen-year BRFS for the entire cohort was 80.4%. BRFS by D'Amico risk group classification cohort analysis was 85.9%, 79.9%, and 62.2% for low, intermediate, and high-risk patients, respectively. Follow-up ranged from 3.6 to 18.4 years; median follow-up was 15.4 years for biochemically free of disease patients. Overall median follow-up was 11.7 years. The median time to BF in those who failed was 5.1 years. CSS was 84%. OS was 37.1%. Average age at time of treatment was 70 years. There was no significant difference in BRFS between low and intermediate risk groups. Conclusion: I 125 monotherapy results in excellent 15-year BRFS and CSS, especially when taking into account the era of treatment effect.

Use of brachytherapy with permanent implants of iodine-125 in localized prostate cancer; La curietherapie par implants permanents d'I-125 dans le cancer localise de la prostate

Energy Technology Data Exchange (ETDEWEB)

Bladou, F.; Serment, G. [Hopital Salvador, Service d' Urologie, 13 - Marseille (France); Salem, N.; Simonian, M. [Hopital Salvador, Dept. de Radiotherapie, 13 - Marseille (France); Rosello, R.; Ternier, F. [Institut Paoli-Calmettes, Dept. de Radiologie, 13 - Marseille (France)

2002-07-01

Approximately 15,000 cases of early stage prostate cancer T1 and T2 are diagnosed every year in France by testing for PSA and performing prostatic biopsies. The treatment of these localized forms is based in most cases on radical prostatectomy or nn external beam radiotherapy. Although the ontological results obtained by these two therapeutic methods are satisfactory and equivalent in the long term, the side effects can be important. For a number of years, trans-perineal brachytherapy using permanent implants of iodine -125 or palladium-103 has proved itself as an alternative therapy with equivalent medium to long-term results. The low urinary, digestive and sexual side effects of prostate brachytherapy are important reasons for the enthusiasm among patients and the medical community for this therapy and the growing number of applications and centres which practice it. In September 1998 we started the prostate brachytherapy programmes- in Marseilles with close collaboration between the department of urology of the Hopital Salvator, and the departments of radiotherapy, medical imaging and medical physics of the Institut Paoli-Calmettes. To date, around 250 patients with localized adenocarcinoma of the prostate have benefited from this alternative therapy in our centre. Preliminary results, with a 3 year-follow-up, are comparable to results published in the literature by pioneer teams. (authors)

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

International Nuclear Information System (INIS)

Souza, Carla Daruich

2012-01-01

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 131 I was used for testing (same chemical behavior as 131 I). 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)

Optimization of sup 125 I ophthalmic plaque brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Astrahan, M.A.; Luxton, G.; Jozsef, G.; Liggett, P.E.; Petrovich, Z. (Univ. of Southern California School of Medicine, Los Angeles (USA))

1990-11-01

Episcleral plaques containing {sup 125}I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged.

Three-dimensional seed reconstruction from an incomplete data set for prostate brachytherapy

International Nuclear Information System (INIS)

Narayanan, Sreeram; Cho, Paul S; MarksII, Robert J

2004-01-01

Intra-operative dosimetry in prostate brachytherapy requires 3D coordinates of the implanted, radioactive seeds. Since CT is not readily available during the implant operation, projection x-rays are commonly used for intra-operative seed localization. Three x-ray projections are usually used. The requirement of the current seed reconstruction algorithms is that the seeds must be identified on all three projections. However, in practice this is often difficult to accomplish due to the problem of heavily clustered and overlapping seeds. We have developed an algorithm that permits seed reconstruction from an incomplete data set. Instead of all three projections, the new algorithm requires only one of the three projections to be complete. Furthermore, even if all three projections are incomplete, it can reconstruct 100% of the implanted seeds depending on how the undetected seeds are distributed among the projections. The method utilizes the principles of epipolar imaging geometry and pseudo-matching of the undetected seeds. The algorithm was successfully applied to a large number of clinical cases where seeds imperceptibly overlap in some projections

Study of dosimetric parameters for iodine-125 brachytherapy sources development from IPEN-CNEN/SP using Monte Carlo method

International Nuclear Information System (INIS)

Oliveira, Tiago Batista de

2016-01-01

Expectations of the World Health Organization for the year 2030 are that the number of cancer deaths is approximately 13.2 million, reflecting the high proportion of this disease in global health issue. With respect to prostate cancer, according to the National Cancer Institute, the number of cases diagnosed worldwide in 2012 was approximately 1.1 million, while in Brazil the data demonstrated the incidence of 68,000 new cases. The treatment of cancer can be performed with surgery (prostatectomy) or radiation therapy. Among radiotherapy, we can highlight the brachytherapy technique, which consists in the introduction of small radioactive sources (seeds) within the prostate, which is delivered a high dose value in the treatment volume and low dose in the surrounding tissues. In Brazil, the medical profession estimates a demand of approximately 8000 seeds / month, and the unit cost of each seed at least US $ 26.00. The AAPM protocol TG-43 recommend the dose-rate constant, radial dose function and anisotropy function for dosimetric analysis LDR brachytherapy seeds. In this work, Monte Carlo simulations were performed in order to assess the dosimetric parameters of the OncoSeed-6711, manufactured by Oncura-GEHealthcare, and a seed developed by Radiation Technology Center, using the MCNP5 code. A 6711 seed, an IPEN seed and the 30 x 30 x 30cm 3 phantom filled with water were modeled to simulate the dose distribution. The 6711 seed parameters were compared with literature, and the results presented relative error less than 0.1% for Λ. In comparison with the 6711 seed, the IPEN model seed dosimetric parameters were similar, account the statistical uncertainty. (author)

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

International Nuclear Information System (INIS)

Shao, Y; Shen, D; Chen, R; Wang, A; Lian, J

2014-01-01

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

Effect of Foley catheters on seed positions and urethral dose in 125I and 103Pd prostate implants

International Nuclear Information System (INIS)

Brezovich, Ivan A.; Pareek, Prem N.; Duan, Jun; Fiveash, John

2001-01-01

Purpose: To estimate the perturbation of seed position and urethral dose, subsequent to withdrawal of urethral catheters. Methods and Materials: A mathematical model based on the volume incompressibility of tissues was used to compute seed positions and doses following removal of the Foley. The model assumed that the central axis of the urethra remains stationary, and that prostate tissue and seeds move radially toward the center of the urethra to fill the void left by the catheter. Seed motion has also been measured using transrectal ultrasound. Results: Based on the computations, seeds located originally close to the urethra travel relatively large distances toward the urethra upon Foley removal, whereas seeds located further away move substantially less. This seed motion leads to higher urethral doses than shown in a standard treatment plan. Dose enhancements increase with catheter size, decrease with increasing prostate volume, are more pronounced for 103 Pd than for 125 I, and range between 3.5% and 32.4%. Postimplant dosimetry is equally affected if images are taken with urethral catheters in place, showing lower urethral doses than actually delivered. Preliminary ultrasound based measurements of seed motion agree with the theory. Conclusion: During the implantation procedure, 12 fr or smaller urethral catheters are preferable to larger diameter catheters if urine drainage is sufficient. Treatment planners should avoid planning seeds at 5 mm or closer from the urethra. Special caution is indicated in prostates having about 20 cm 3 or smaller volumes, and when 103 Pd is used. Postimplant dosimetry is susceptible to the same errors

Synthesis of (125) I-lamivudine and (125) I-lamivudine-ursodeoxycholic acid codrug.

Science.gov (United States)

Motaleb, M A; Abo-Kul, M; Ibrahim, Samy M; Saad, Shokry M; Arafat, Muhammad

2016-09-01

The preparation of (125) I-lamivudine ((125) I-3TC) and (125) I-lamivudine-ursodeoxycholic acid codrug ((125) I-3TC-UDCA), suitable for comparative biodistribution studies, is described. The synthesis of the unlabeled precursor 3TC-UDCA proceeds in an 11.6% yield, and the radiolabelling yields for (125) I-3TC and (125) I-3TC-UDCA were 89 and 92%, respectively. The final products are radiochemically pure (greater than 98%). Copyright © 2016 John Wiley & Sons, Ltd.

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.

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

International Nuclear Information System (INIS)

Thaker, Nikhil G.; Kudchadker, Rajat J.; Swanson, David A.; Albert, Jeffrey M.; Mahmood, Usama; Pugh, Thomas J.; Boehling, Nicholas S.; Bruno, Teresa L.; Prestidge, Bradley R.; Crook, Juanita M.; Cox, Brett W.; Potters, Louis; Moran, Brian J.; Keyes, Mira; Kuban, Deborah A.; Frank, Steven J.

2014-01-01

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 ( 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

Radiation safety and protection of close contacts from radiators after implantation of radioactive 125I seeds

International Nuclear Information System (INIS)

Sui Aixia; Li Jianmin; Tang Fulong; Zhang Hongtao; Ren Ju'na; Pang Linbin; Xia Haishui; Gao Zhen; Wu Lili; Wang Juan

2012-01-01

Objective: To study the effective dose and precaution time of the irradiation of the close contact from the radiators who underwent implantation of radioactive 125 I seeds so as to guide scientifically people how to avoid radiation damage. Methods: Twenty patients with different types of cancer underwent implantation of radioactive 125 I seeds with the median value of implantation depth of 2.16 cm. Within 24 h after the operations the dose rates 30 cm and 100 cm from the skin were measured with pocket-size radiometer so as to imitate the situations of the close contacts. The effective doses and precaution times of different persons were calculated according to relevant formula. Results: The dose rate a person received at the same time points (1, 54, 78, and 109 d, respectively) decreased along with the increase of the distance from the skin (t=5.962, 5.961, 5.961, 5.962, P<0.05), and the dose rate a person received at the same distance from the skin decreased along with the extension of time (30 cm: t=6.236, 6.236, 6.235, P<0.05; 100 cm: t=7.310, 7.315, 7.314, P<0.05). At different time points, the dose rates at 30 cm distance point were all significant higher than those at the 100 cm point (P <0.05). The adult living together, minors and pregnant women sharing the room, colleagues,adults who slept together with the patients began to reach the 50% dose constraint values 0, 54, 78 and 109 days after the operation. Conclusions: After their precaution time, it's safe to contact with the patients for the groups; otherwise, it's necessary to take some protect works within the precaution time. (authors)

Biochemical disease-free survival following I-125 prostate implantation

International Nuclear Information System (INIS)

Beyer, David C.; Priestley, Joseph B.

1995-01-01

Purpose/Objective: To assess the five-year clinical and biochemical results of ultrasound-guided permanent I-125 brachytherapy in early prostate cancer. Biochemical disease-free survival (BDFS) is reported, using PSA follow-up and is compared to the surgical and radiation therapy literature. Materials and Methods: From 12/88 through 12/93, ultrasound-guided brachytherapy was preplanned with I-125 and delivered 16,000 cGy as the sole treatment in 499 patients. All were clinically staged as T1 or T2 - N0M0 adenocarcinoma of the prostate. Within the first year, 19 patients were lost to follow-up and have been excluded from further study. The remaining 480 patients form the basis of this report. Clinical status and PSA values were systematically recorded before and after treatment. Results: With a median follow-up of 35 months (3-70) the actuarial clinical local control is 83%. Both stage and grade are shown to predict for this endpoint. Actuarial BDFS is also correlated with stage, grade, and PSA at presentation. Biochemical disease-free survival at five years is 94% for T1, 70% for unilateral T2, and 34% for T2c tumors. Grade is also predictive, ranging from 85% in low-grade tumors to 30% in high-grade tumors. In a multivariate analysis, the pretreatment PSA is most highly correlated (p 10 had a BDFS of 40%. Complications have been few, with severe urinary urgency or dysuria in 4% and both incontinence and proctitis seen in 1%. Conclusion: While biochemical disease-free survival reports in the literature are immature and have short follow-up, our data compares favorably with studies following radical prostatectomy or radiation therapy. Further follow-up of this cohort is required. The complication rate is low and patient acceptance excellent. Permanent implantation of I-125 as the sole treatment for early prostate cancer is a viable alternative for patients with early stage and low- to moderate-grade cancers. The PSA provides significant prognostic information and

Biochemical disease-free survival following I-125 prostate implantation

Energy Technology Data Exchange (ETDEWEB)

Beyer, David C; Priestley, Joseph B

1995-07-01

Purpose/Objective: To assess the five-year clinical and biochemical results of ultrasound-guided permanent I-125 brachytherapy in early prostate cancer. Biochemical disease-free survival (BDFS) is reported, using PSA follow-up and is compared to the surgical and radiation therapy literature. Materials and Methods: From 12/88 through 12/93, ultrasound-guided brachytherapy was preplanned with I-125 and delivered 16,000 cGy as the sole treatment in 499 patients. All were clinically staged as T1 or T2 - N0M0 adenocarcinoma of the prostate. Within the first year, 19 patients were lost to follow-up and have been excluded from further study. The remaining 480 patients form the basis of this report. Clinical status and PSA values were systematically recorded before and after treatment. Results: With a median follow-up of 35 months (3-70) the actuarial clinical local control is 83%. Both stage and grade are shown to predict for this endpoint. Actuarial BDFS is also correlated with stage, grade, and PSA at presentation. Biochemical disease-free survival at five years is 94% for T1, 70% for unilateral T2, and 34% for T2c tumors. Grade is also predictive, ranging from 85% in low-grade tumors to 30% in high-grade tumors. In a multivariate analysis, the pretreatment PSA is most highly correlated (p < 0.0001). Patients with a normal pretreatment PSA enjoyed 93% BDFS, while those presenting with PSA > 10 had a BDFS of 40%. Complications have been few, with severe urinary urgency or dysuria in 4% and both incontinence and proctitis seen in 1%. Conclusion: While biochemical disease-free survival reports in the literature are immature and have short follow-up, our data compares favorably with studies following radical prostatectomy or radiation therapy. Further follow-up of this cohort is required. The complication rate is low and patient acceptance excellent. Permanent implantation of I-125 as the sole treatment for early prostate cancer is a viable alternative for patients with

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

Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation.

Science.gov (United States)

Villegas, Fernanda; Tilly, Nina; Ahnesjö, Anders

2013-09-07

The stochastic nature of ionizing radiation interactions causes a microdosimetric spread in energy depositions for cell or cell nucleus-sized volumes. The magnitude of the spread may be a confounding factor in dose response analysis. The aim of this work is to give values for the microdosimetric spread for a range of doses imparted by (125)I and (192)Ir brachytherapy radionuclides, and for a (60)Co source. An upgraded version of the Monte Carlo code PENELOPE was used to obtain frequency distributions of specific energy for each of these radiation qualities and for four different cell nucleus-sized volumes. The results demonstrate that the magnitude of the microdosimetric spread increases when the target size decreases or when the energy of the radiation quality is reduced. Frequency distributions calculated according to the formalism of Kellerer and Chmelevsky using full convolution of the Monte Carlo calculated single track frequency distributions confirm that at doses exceeding 0.08 Gy for (125)I, 0.1 Gy for (192)Ir, and 0.2 Gy for (60)Co, the resulting distribution can be accurately approximated with a normal distribution. A parameterization of the width of the distribution as a function of dose and target volume of interest is presented as a convenient form for the use in response modelling or similar contexts.

Dosimetric comparison of interactive planned and dynamic dose calculated prostate seed brachytherapy

International Nuclear Information System (INIS)

Meijer, Gert J.; Berg, Hetty A. van den; Hurkmans, Coen W.; Stijns, Pascal E.; Weterings, Jan H.

2006-01-01

Purpose: To compare the dosimetrical results of an interactive planning procedure and a procedure based on dynamic dose calculation for permanent prostate brachytherapy. Materials and methods: Between 6/2000 and 11/2005, 510 patients underwent 125 I implants for T1-T2 prostate cancer. Before 4/2003, 187 patients were treated using an interactive technique that included needle updating. After that period, 323 patients were treated with a more refined dynamic technique that included constant updating of the deposited seed position. The comparison is based on postimplant dose-volume parameters such as the V 100 and d 90 for the target, V 100 r for the rectum and d 10 u for the urethra. Furthermore, the target volume ratios (TVR=V 100 body /V 100 ), and the homogeneity indices (HI=[V 100 -V 150 ]/V 100 ) were calculated as additional quality parameters. Results: The dose outside the target volume was significantly reduced, the V 100 r decreased from 1.4cm 3 for the interactive technique to 0.6cm 3 for the dynamic technique. Similarly the mean TVR reduced from 1.66 to 1.44. In addition, the mean V 100 increased from 92% for the interactive procedure to 95% for the dynamic procedure. More importantly, the percentage of patients with a V 100 10 u (136% vs. 140%) and the HI (0.58 vs. 0.51). Conclusion: The dynamic implant procedure resulted in improved implants. Almost ideal dose coverage was achieved, while minimizing the dose outside the prostate

Focal salvage iodine-125 brachytherapy for prostate cancer recurrences after primary radiotherapy: A retrospective study regarding toxicity, biochemical outcome and quality of life

International Nuclear Information System (INIS)

Peters, Max; Maenhout, Metha; Voort van Zyp, Jochem R.N. van der; Moerland, Marinus A.; Moman, Maaike R.; Steuten, Lotte M.G.; Deursen, Marijke J.H. van; Vulpen, Marco van

2014-01-01

Purpose: Whole-gland salvage for recurrent prostate cancer (PCa) shows high failure and toxicity rates. Early and adequate localization of recurrences enables focal salvage, thereby potentially improving functional outcomes, while maintaining cancer control. Materials and methods: Retrospective analysis yielded 20 focal salvage I125 brachytherapy patients for locally recurrent PCa after primary radiotherapy. Tumor was defined by multiparametric MRI and correspondence with transrectal biopsies. Dose data were obtained intra-operatively. The tumor was prescribed ⩾144 Gy. Toxicity was scored by the Common Terminology Criteria for Adverse Events version 4 (CTCAE-4). Biochemical failure (BF) was defined using the Phoenix criteria (PSA-nadir + 2.0 ng/ml). Quality of life (QoL) was measured by SF-36 Health Survey and European Organization of Research and Treatment of Cancer (EORTC) C30+3 and PR25 questionnaires. Results: With a median follow-up of 36 months (range 10–45), six patients experienced BF, of which three had no initial response. Grade 3 genitourinary (GU) toxicity occurred in one patient (a urethral stricture). The five previously potent patients retained erectile function. QoL remained decreased with regard to urinary symptoms. Conclusion: Focal salvage I125 brachytherapy showed one grade 3 GU toxicity in the 20 treated patients. Biochemical response and QoL were acceptable

Production of Pd 103 seed from Rh targets for brachytherapy

International Nuclear Information System (INIS)

Afarideh, H.; Ardaneh, K.; Sadeghi, M.

2000-01-01

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

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

International Nuclear Information System (INIS)

Sinha, Neeharika; Cifter, Gizem; Sajo, Erno; Kumar, Rajiv; Sridhar, Srinivas; Nguyen, Paul L.; Cormack, Robert A.; Makrigiorgos, G. Mike; Ngwa, Wilfred

2015-01-01

Purpose: Recent studies show promise that administering gold nanoparticles (GNP) to tumor cells during brachytherapy could significantly enhance radiation damage to the tumor. A new strategy proposed for sustained administration of the GNP in prostate tumors is to load them into routinely used brachytherapy spacers for customizable in situ release after implantation. This in silico study investigated the intratumor biodistribution and corresponding dose enhancement over time due to GNP released from such GNP-loaded brachytherapy spacers (GBS). Method and Materials: An experimentally determined intratumoral diffusion coefficient (D) for 10-nm nanoparticles was used to estimate D for other sizes by using the Stokes-Einstein equation. GNP concentration profiles, obtained using D, were then used to calculate the corresponding dose enhancement factor (DEF) for each tumor voxel, using dose painting-by-numbers approach, for times relevant to the considered brachytherapy sources' lifetimes. The investigation was carried out as a function of GNP size for the clinically applicable low-dose-rate brachytherapy sources iodine-125 (I-125), palladium-103 (Pd-103), and cesium-131 (Cs-131). Results: Results showed that dose enhancement to tumor voxels and subvolumes during brachytherapy can be customized by varying the size of GNP released or eluted from the GBS. For example, using a concentration of 7 mg/g GNP, significant DEF (>20%) could be achieved 5 mm from a GBS after 5, 12, 25, 46, 72, 120, and 195 days, respectively, for GNP sizes of 2, 5, 10, 20, 30, and 50 nm and for 80 nm when treating with I-125. Conclusions: Analyses showed that using Cs-131 provides the highest dose enhancement to tumor voxels. However, given its relatively longer half-life, I-125 presents the most flexibility for customizing the dose enhancement as a function of GNP size. These findings provide a useful reference for further work toward development of potential new brachytherapy application

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-02-01

Purpose: Recent studies show promise that administering gold nanoparticles (GNP) to tumor cells during brachytherapy could significantly enhance radiation damage to the tumor. A new strategy proposed for sustained administration of the GNP in prostate tumors is to load them into routinely used brachytherapy spacers for customizable in situ release after implantation. This in silico study investigated the intratumor biodistribution and corresponding dose enhancement over time due to GNP released from such GNP-loaded brachytherapy spacers (GBS). Method and Materials: An experimentally determined intratumoral diffusion coefficient (D) for 10-nm nanoparticles was used to estimate D for other sizes by using the Stokes-Einstein equation. GNP concentration profiles, obtained using D, were then used to calculate the corresponding dose enhancement factor (DEF) for each tumor voxel, using dose painting-by-numbers approach, for times relevant to the considered brachytherapy sources' lifetimes. The investigation was carried out as a function of GNP size for the clinically applicable low-dose-rate brachytherapy sources iodine-125 (I-125), palladium-103 (Pd-103), and cesium-131 (Cs-131). Results: Results showed that dose enhancement to tumor voxels and subvolumes during brachytherapy can be customized by varying the size of GNP released or eluted from the GBS. For example, using a concentration of 7 mg/g GNP, significant DEF (>20%) could be achieved 5 mm from a GBS after 5, 12, 25, 46, 72, 120, and 195 days, respectively, for GNP sizes of 2, 5, 10, 20, 30, and 50 nm and for 80 nm when treating with I-125. Conclusions: Analyses showed that using Cs-131 provides the highest dose enhancement to tumor voxels. However, given its relatively longer half-life, I-125 presents the most flexibility for customizing the dose enhancement as a function of GNP size. These findings provide a useful reference for further work toward development of potential new brachytherapy application

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

Computational model of Amersham I-125 source model 6711 and Prosper Pd-103 source model MED3633 using MCNP

Energy Technology Data Exchange (ETDEWEB)

Menezes, Artur F.; Reis Junior, Juraci P.; Silva, Ademir X., E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Rosa, Luiz A.R. da, E-mail: lrosa@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Facure, Alessandro [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Cardoso, Simone C., E-mail: Simone@if.ufrj.b [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Nuclear

2011-07-01

Brachytherapy is used in cancer treatment at shorter distances through the use of small encapsulated source of ionizing radiation. In such treatment, a radiation source is positioned directly into or near the target volume to be treated. In this study the Monte Carlo based MCNP code was used to model and simulate the I-125 Amersham Health source model 6711 and the Pd-103 Prospera source model MED3633 in order to obtain the dosimetric parameter dose rate constant ({Lambda}) . The sources geometries were modeled and implemented in MCNPX code. The dose rate constant is an important parameter prostate LDR brachytherapy's treatments planning. This study was based on American Association of Physicists in Medicine (AAPM) recommendations which were produced by its Task Group 43. The results obtained were 0.941 and 0.65 for the dose rate constants of I-125 and Pd-103 sources, respectively. They present good agreement with the literature values based on different Monte Carlo codes. (author)

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.

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)

Rectal and urinary morbidity in patients undergoing prostate I-125 implant

International Nuclear Information System (INIS)

Hu, Kenneth; Wallner, Kent

1997-01-01

PURPOSE: To determine the risk of urinary incontinence or severe rectal complications in patients who have TURP/TUIP or rectal bleeding after I-125 prostate brachytherapy. MATERIAL AND METHODS: One hundred nine patients with T1-T2 prostatic carcinoma were treated with I-125 implantation from 1988 through 1994. Ten patients underwent TURP/TUIP after brachtherapy to relieve urinary obstruction refractory to non-surgical management. Twenty-two developed rectal morbidity and were subsequently followed with endoscopy and serial clinical evaluation. RESULTS: Permanent urinary incontinence following TURP/TUIP developed in seven of 10 patients. Urinary incontinence was mild in three patients (LENT score = 1) and severe in 4 additional patients (LENT score = 3). There was no relationship between the degree of incontinence and the use of TURP versus TUIP, mass of tissue resected, or time between brachytherapy and TURP/TUIP. Urethral doses were higher than we generally recommend (> 140 Gy) in the 5 patients for whom detailed urethral radiation dose information was available, Rectal morbidity developed in twenty-two patients. Twenty experienced radiation proctitis-related bright red blood per rectum (BRBPR), the majority of which ((15(20))) were mild (RTOG score = 1) and treated with medical management. The other 5 developed either a rectal ulcer ((3(5))) or fistula ((2(5))). The two patients without significant BRBPR developed a fistula and ulcer. Two of three patients with fistulas had predisposing conditions (pre-implant history of fistula and previous pelvic radiation for rectal cancer). All four rectal ulcers healed with conservative management. CONCLUSION: Permanent urinary incontinence is common in patients who require a TURP/TUIP after prostate brachytherapy. Its cause is multifactorial and may include surgically-related damage to the urinary sphincters and radiation dose to the uretha. Rectal morbidity after prostate brachtherapy is mild in the majority of cases and

Directional interstitial brachytherapy from simulation to application

Science.gov (United States)

Lin, Liyong

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

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

International Nuclear Information System (INIS)

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.

2011-01-01

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)

SU-E-T-259: Development of a Primary Standard for LDR Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Shen, H; McEwen, M [National Research Council, Ottawa, ON (Canada)

2015-06-15

Purpose: The National Research Council initiated a program in 2012 to develop a primary standard to calibrate I-125 and Pd-103 sources used for LDR brachytherapy and disseminate this through calibration services to Canadian users. This will simplify procedures as Canadian cancer centres currently have to ship instruments to the US. Methods: The standard is based on a commercial version of the wide-angle free air chamber (WAFAC) pioneered by NIST. Significant enhancements were implemented to improve signal-to-noise and measurement reproducibility and eliminate electric field effects. Validation of this ionization chamber was then carried out in a low-energy X -ray beam (∼ 31 keV) where the dose rate had been previously established using the existing NRC primary standard free-air chamber. As a final component of this initial testing, measurements were made with a set of I-125 seeds (with air kerma strength traceable to NIST). Results: Excellent agreement of the two NRC free-air chambers was obtained within the combined standard uncertainty of 0.5 %. However, it was found that the WAFAC response is very sensitive to the beam geometry (distance from the source, diameter of the beam-defining aperture, etc) and Monte Carlo calculations, carried out to evaluate these geometry corrections, have confirmed the experimental results. The results for the seed measurements indicated a precision of better than 1 % is achievable for a reasonable acquisition time and the air kerma strength agreed with the manufacturer (NIST-traceable) value within 2 %. Conclusion: The prototype primary standard for LDR brachytherapy has met accuracy target of 3 % for the determination of air kerma strength. Work is ongoing to refine operation of the device and develop the calibration protocol for clinical users, with an anticipated launch of a calibration service in late 2015.

Automated treatment planning engine for prostate seed implant brachytherapy

International Nuclear Information System (INIS)

Yu Yan; Zhang, J.B.Y.; Brasacchio, Ralph A.; Okunieff, Paul G.; Rubens, Deborah J.; Strang, John G.; Soni, Arvind; Messing, Edward M.

1999-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1984-09-01

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

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

International Nuclear Information System (INIS)

Tétreault-Laflamme, Audrey; Zilli, Thomas; Meissner, Aliza; Larrivée, Sandra; Sylvestre, Marie-Pierre; Delouya, Guila

2014-01-01

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 125 I 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

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

International Nuclear Information System (INIS)

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

2015-01-01

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)

Treatment of hepatocellular carcinoma adjacent to large blood vessels using 1.5T MRI-guided percutaneous radiofrequency ablation combined with iodine-125 radioactive seed implantation

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Lin, Zheng-Yu, E-mail: linsinlan@yahoo.com.cn [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China); Chen, Jin, E-mail: snow8968851@163.com [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China); Deng, Xiu-Fen, E-mail: dxf197286@yahoo.com.cn [The Department of Radiology, First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou 350005 (China)

2012-11-15

Objective: The objective is to study the technology associated with and feasibility of the treatment of hepatocellular carcinoma (HCC) adjacent to large blood vessels using 1.5T MRI-guided radiofrequency ablation combined with iodine-125 (I-125) radioactive seed implantation. Methods: Sixteen patients with a total of 24 HCC lesions (average maximum diameter: 2.35 {+-} 1.03 cm) were pathologically confirmed by biopsy or clinically diagnosed received 1.5T MRI-guided percutaneous radiofrequency ablation (RFA) treatment. Each patient had one lesion adjacent to large blood vessels ({>=}3 mm); after the ablation, I-125 radioactive seeds were implanted in the portions of the lesions that were adjacent to the blood vessels. Results: All the ablations and I-125 radioactive seed implantations were successful; a total of 118 seeds were implanted. The ablated lesions exhibited hypointense signals on the T2WI sequence with a thin rim of hyperintense signals; they also exhibited significant hyperintense signals on the T1WI sequence with clear boundaries. The average follow-up period was 11.1 {+-} 6.2 months. There were 23 complete responses and one partial response in the 24 lesions. The alpha-fetoprotein (AFP) levels of the patients significantly decreased. Conclusion: The 1.5T MRI-guided RFA combined with I-125 radioactive seed implantation for the treatment of HCC adjacent to large blood vessels is an effective technology.

Use of brachytherapy with permanent implants of iodine-125 in localized prostate cancer

International Nuclear Information System (INIS)

Bladou, F.; Serment, G.; Salem, N.; Simonian, M.; Rosello, R.; Ternier, F.

2002-01-01

Approximately 15,000 cases of early stage prostate cancer T1 and T2 are diagnosed every year in France by testing for PSA and performing prostatic biopsies. The treatment of these localized forms is based in most cases on radical prostatectomy or nn external beam radiotherapy. Although the ontological results obtained by these two therapeutic methods are satisfactory and equivalent in the long term, the side effects can be important. For a number of years, trans-perineal brachytherapy using permanent implants of iodine -125 or palladium-103 has proved itself as an alternative therapy with equivalent medium to long-term results. The low urinary, digestive and sexual side effects of prostate brachytherapy are important reasons for the enthusiasm among patients and the medical community for this therapy and the growing number of applications and centres which practice it. In September 1998 we started the prostate brachytherapy programmes- in Marseilles with close collaboration between the department of urology of the Hopital Salvator, and the departments of radiotherapy, medical imaging and medical physics of the Institut Paoli-Calmettes. To date, around 250 patients with localized adenocarcinoma of the prostate have benefited from this alternative therapy in our centre. Preliminary results, with a 3 year-follow-up, are comparable to results published in the literature by pioneer teams. (authors)

A new human eye model for ophthalmic brachytherapy dosimetry

International Nuclear Information System (INIS)

Yoriyaz, H.; Sanchez, A.; Dos Santos, A.

2005-01-01

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 125 I seeds and 60 Co 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)

Development of prostate voxel models for brachytherapy treatment

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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)

Evaluating the Phoenix definition of biochemical failure after (125)I prostate brachytherapy: Can PSA kinetics distinguish PSA failures from PSA bounces?

Science.gov (United States)

Thompson, Anna; Keyes, Mira; Pickles, Tom; Palma, David; Moravan, Veronika; Spadinger, Ingrid; Lapointe, Vincent; Morris, W James

2010-10-01

To evaluate the prostate-specific antigen (PSA) kinetics of PSA failure (PSAf) and PSA bounce (PSAb) after permanent (125)I prostate brachytherapy (PB). The study included 1,006 consecutive low and "low tier" intermediate-risk patients treated with (125)I PB, with a potential minimum follow-up of 4 years. Patients who met the Phoenix definition of biochemical failure (nadir + 2 ng/mL(-1)) were identified. If the PSA subsequently fell to ≤0.5 ng/mL(-1)without intervention, this was considered a PSAb. All others were scored as true PSAf. Patient, tumor and dosimetric characteristics were compared between groups using the chi-square test and analysis of variance to evaluate factors associated with PSAf or PSAb. Median follow-up was 54 months. Of the 1,006 men, 57 patients triggered the Phoenix definition of PSA failure, 32 (56%) were true PSAf, and 25 PSAb (44%). The median time to trigger nadir + 2 was 20.6 months (range, 6-36) vs. 49 mo (range, 12-83) for PSAb vs. PSAf groups (p < 0.001). The PSAb patients were significantly younger (p < 0.0001), had shorter time to reach the nadir (median 6 vs. 11.5 months, p = 0.001) and had a shorter PSA doubling time (p = 0.05). Men younger than age 70 who trigger nadir +2 PSA failure within 38 months of implant have an 80% likelihood of having PSAb and 20% chance of PSAf. With adequate follow-up, 44% of PSA failures by the Phoenix definition in our cohort were found to be benign PSA bounces. Our study reinforces the need for adequate follow-up when reporting PB PSA outcomes, to ensure accurate estimates of treatment efficacy and to avoid unnecessary secondary interventions. 2010. Published by Elsevier Inc. All rights reserved.

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

International Nuclear Information System (INIS)

Thompson, Anna; Keyes, Mira; Pickles, Tom

2010-01-01

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

Dosimetric comparison of interactive planned and dynamic dose calculated prostate seed brachytherapy.

Science.gov (United States)

Meijer, Gert J; van den Berg, Hetty A; Hurkmans, Coen W; Stijns, Pascal E; Weterings, Jan H

2006-09-01

To compare the dosimetrical results of an interactive planning procedure and a procedure based on dynamic dose calculation for permanent prostate brachytherapy. Between 6/2000 and 11/2005, 510 patients underwent (125)I implants for T1-T2 prostate cancer. Before 4/2003, 187 patients were treated using an interactive technique that included needle updating. After that period, 323 patients were treated with a more refined dynamic technique that included constant updating of the deposited seed position. The comparison is based on postimplant dose - volume parameters such as the V(100) and d(90) for the target, V(100)(r) for the rectum and d(10)(u) for the urethra. Furthermore, the target volume ratios (TVR identical with V(100)(body)/V(100)), and the homogeneity indices (HI identical with [V(100)-V(150)]/V(100)) were calculated as additional quality parameters. The dose outside the target volume was significantly reduced, the V(100)(r) decreased from 1.4 cm(3) for the interactive technique to 0.6 cm(3) for the dynamic technique. Similarly the mean TVR reduced from 1.66 to 1.44. In addition, the mean V(100) increased from 92% for the interactive procedure to 95% for the dynamic procedure. More importantly, the percentage of patients with a V(100) < 80% reduced from 5% to 1%. A slight decline was observed with regard to the d(10)(u) (136% vs. 140%) and the HI (0.58 vs. 0.51). The dynamic implant procedure resulted in improved implants. Almost ideal dose coverage was achieved, while minimizing the dose outside the prostate.

Monte Carlo simulation of the dose distribution around the 125I model 6711 seed as function of radius of the silver cylinder using the Penelope code

International Nuclear Information System (INIS)

Nerio, U.; Chica, L.; Paul, A.

2004-01-01

The Monte Carlo method is applied to find the dose rates distribution in tissue around 125 I seeds model 6711 as a function of the silver cylinder radius, R sc (0.017, 0.021, 0.025, 0.029 and 0.033) cm are used as radius values. It is found here that the dose rate at any point within the tissue decreases as R sc increases. The relative difference of dose rate that produced by the standard R sc seed, is less than 5%, for seeds with Rsc between 0.017 and 0.033 cm. (author)

Iodine 125 Brachytherapy With Vitrectomy and Silicone Oil in the Treatment of Uveal Melanoma: 1-to-1 Matched Case-Control Series

International Nuclear Information System (INIS)

McCannel, Tara A.; McCannel, Colin A.

2014-01-01

Purpose: We initially reported the radiation-attenuating effect of silicone oil 1000 centistokes for iodine 125. The purpose of this report was to compare the clinical outcomes in case patients who had iodine 125 brachytherapy with vitrectomy and silicone oil 1000 centistokes with the outcomes in matched control patients who underwent brachytherapy alone. Methods and Materials: Consecutive patients with uveal melanoma who were treated with iodine 125 plaque brachytherapy and vitrectomy with silicone oil with minimum 1-year follow-up were included. Control patients who underwent brachytherapy alone were matched for tumor size, location, and sex. Baseline patient and tumor characteristics and tumor response to radiation, final visual acuity, macular status, central macular thickness by ocular coherence tomography (OCT), cataract progression, and metastasis at last follow-up visit were compared. Surgical complications were also determined. Results: Twenty case patients met the inclusion criteria. The average follow-up time was 22.1 months in case patients and 19.4 months in control patients. The final logMAR vision was 0.81 in case patients and 1.1 in control patients (P=.071); 8 case patients and 16 control patients had abnormal macular findings (P=.011); and the average central macular thickness by OCT was 293.2 μm in case patients and 408.5 μm in control patients (P=.016). Eleven case patients (55%) and 1 control patient (5%) had required cataract surgery at last follow-up (P=.002). Four patients in the case group and 1 patient in the control group experienced metastasis (P=.18). Among the cases, intraoperative retinal tear occurred in 3 patients; total serous retinal detachment and macular hole developed in 1 case patient each. There was no case of rhegmatogenous retinal detachment, treatment failure, or local tumor dissemination in case patients or control patients. Conclusions: With up to 3 years of clinical follow-up, silicone oil during brachytherapy

Iodine 125 Brachytherapy With Vitrectomy and Silicone Oil in the Treatment of Uveal Melanoma: 1-to-1 Matched Case-Control Series

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McCannel, Tara A., E-mail: TMcCannel@jsei.ucla.edu; McCannel, Colin A.

2014-06-01

Purpose: We initially reported the radiation-attenuating effect of silicone oil 1000 centistokes for iodine 125. The purpose of this report was to compare the clinical outcomes in case patients who had iodine 125 brachytherapy with vitrectomy and silicone oil 1000 centistokes with the outcomes in matched control patients who underwent brachytherapy alone. Methods and Materials: Consecutive patients with uveal melanoma who were treated with iodine 125 plaque brachytherapy and vitrectomy with silicone oil with minimum 1-year follow-up were included. Control patients who underwent brachytherapy alone were matched for tumor size, location, and sex. Baseline patient and tumor characteristics and tumor response to radiation, final visual acuity, macular status, central macular thickness by ocular coherence tomography (OCT), cataract progression, and metastasis at last follow-up visit were compared. Surgical complications were also determined. Results: Twenty case patients met the inclusion criteria. The average follow-up time was 22.1 months in case patients and 19.4 months in control patients. The final logMAR vision was 0.81 in case patients and 1.1 in control patients (P=.071); 8 case patients and 16 control patients had abnormal macular findings (P=.011); and the average central macular thickness by OCT was 293.2 μm in case patients and 408.5 μm in control patients (P=.016). Eleven case patients (55%) and 1 control patient (5%) had required cataract surgery at last follow-up (P=.002). Four patients in the case group and 1 patient in the control group experienced metastasis (P=.18). Among the cases, intraoperative retinal tear occurred in 3 patients; total serous retinal detachment and macular hole developed in 1 case patient each. There was no case of rhegmatogenous retinal detachment, treatment failure, or local tumor dissemination in case patients or control patients. Conclusions: With up to 3 years of clinical follow-up, silicone oil during brachytherapy

Optical fibre luminescence sensor for real-time LDR brachytherapy dosimetry

Science.gov (United States)

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

2018-02-01

An optical fibre sensor for monitoring low dose radiation is presented. The sensor is based on a scintillation material embedded within the optical fibre core, which emits visible light when exposed to low level ionising radiation. The incident level of ionising radiation can be determined by analysing the optical emission. An optical fibre sensor is developed, based on radioluminescence whereby radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 700μm of a 1mm plastic optical fibre. The sensor is designed for in-vivo monitoring of the radiation dose during radio-active seed implantation for low dose rate (LDR) brachytherapy, in prostate cancer treatment, providing radiation oncologists with real-time information of the radiation dose to the target area and/or nearby organs at risk (OARs). The radiation from the brachytherapy seeds causes emission of visible light from the scintillation material through the process of radioluminescence, which penetrates the fibre, propagating along the optical fibre for remote detection using a multi-pixel photon counter. The sensor demonstrates a high sensitivity to 0.397mCi of Iodine125, the radioactive source most commonly used in brachytherapy for treating prostate cancer.

Relationship between two year PSA nadir and biochemical recurrence in prostate cancer patients treated with iodine-125 brachytherapy

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Carlos Antônio da Silva Franca

2014-04-01

Full Text Available Objective To evaluate the relationship between two year PSA nadir (PSAn after brachytherapy and biochemical recurrence rates in prostate cancer patients. Materials and Methods In the period from January 1998 to August 2007, 120 patients were treated with iodine-125 brachytherapy alone. The results analysis was based on the definition of biochemical recurrence according to the Phoenix Consensus. Results Biochemical control was observed in 86 patients (71.7%, and biochemical recurrence, in 34 (28.3%. Mean PSAn was 0.53 ng/ml. The mean follow-up was 98 months. The patients were divided into two groups: group 1, with two year PSAn < 0.5 ng/ml after brachytherapy (74 patients; 61.7%, and group 2, with two year PSAn ≥ 0.5 ng/ml after brachytherapy (46 patients; 38.3%. Group 1 presented biochemical recurrence in 15 patients (20.3%, and group 2, in 19 patients (43.2% (p < 0.02. The analysis of biochemical disease-free survival at seven years, stratified by the two groups, showed values of 80% and 64% (p < 0.02, respectively. Conclusion Levels of two year PSAn ≥ 0.5 ng/ml after brachytherapy are strongly correlated with a poor prognosis. This fact may help to identify patients at risk for disease recurrence.

Dosimetric study of a new polymer encapsulated palladium-103 seed

International Nuclear Information System (INIS)

Bernard, S; Vynckier, S

2005-01-01

The use of low-energy photon emitters for brachytherapy applications, as in the treatment of prostate or ocular tumours, has increased significantly over the last few years. Several new seed models utilizing 103 Pd and 125 I have recently been introduced. Following the TG43U1 recommendations of the AAPM (American Association of Physicists in Medicine) (Rivard et al 2004 Med. Phys. 31 633), dose distributions around these low-energy photon emitters are characterized by the dose rate constant, the radial dose function and the anisotropy function in water. These functions and constants can be measured for each new seed in a solid phantom (i.e. solid water such as WT1) using high spatial resolution detectors such as very small thermoluminescent detectors. These experimental results in solid water must then be converted into liquid water by using Monte Carlo simulations. This paper presents the dosimetric parameters of a new palladium seed, OptiSeed TM (produced by International Brachytherapy (IBt), Seneffe, Belgium), made with a biocompatible polymeric shell and with a design that differs from the hollow titanium encapsulated seed, InterSource 103 , produced by the same company. A polymer encapsulation was chosen by the company IBt in order to reduce the quantity of radioactive material needed for a given dose rate, and to improve the symmetry of the radiation field around the seed. The necessary experimental data were obtained by measurements with LiF thermoluminescent dosimeters (1 mm 3 ) in a solid water phantom (WT1) and then converted to values in liquid water using Monte Carlo calculations (MCNP-4C). Comparison of the results with a previous study by Reniers et al (2002 Appl. Radiat. Isot. 57 805) shows very good agreement for the dose rate constant and for the radial dose function. In addition, the results also indicate an improvement in isotropy compared to a conventional titanium encapsulated seed. The relative dose (anisotropy value relative to 90 deg.) from

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

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

International Nuclear Information System (INIS)

Souza, Daiane C.B.; Rostelato, Maria Elisa C.; Vicente, Roberto; Zeituni, Carlos A.; Tiezzi, Rodrigo; Costa, Osvaldo L.; Souza, Carla D.; Peleias Junior, Fernando S.; Rodrigues, Bruna T.; Souza, Anderson S.; Batista, Talita Q.; Melo, Emerson R.; Camargo, Anderson R.; Karam Junior, Dib

2015-01-01

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

Gold nanoparticle-based brachytherapy enhancement in choroidal melanoma using a full Monte Carlo model of the human eye.

Science.gov (United States)

Asadi, Somayeh; Vaez-zadeh, Mehdi; Masoudi, S Farhad; Rahmani, Faezeh; Knaup, Courtney; Meigooni, Ali S

2015-09-08

The effects of gold nanoparticles (GNPs) in 125I brachytherapy dose enhancement on choroidal melanoma are examined using the Monte Carlo simulation technique. Usually, Monte Carlo ophthalmic brachytherapy dosimetry is performed in a water phantom. However, here, the compositions of human eye have been considered instead of water. Both human eye and water phantoms have been simulated with MCNP5 code. These simulations were performed for a fully loaded 16 mm COMS eye plaque containing 13 125I seeds. The dose delivered to the tumor and normal tissues have been calculated in both phantoms with and without GNPs. Normally, the radiation therapy of cancer patients is designed to deliver a required dose to the tumor while sparing the surrounding normal tissues. However, as the normal and cancerous cells absorbed dose in an almost identical fashion, the normal tissue absorbed radiation dose during the treatment time. The use of GNPs in combination with radiotherapy in the treatment of tumor decreases the absorbed dose by normal tissues. The results indicate that the dose to the tumor in an eyeball implanted with COMS plaque increases with increasing GNPs concentration inside the target. Therefore, the required irradiation time for the tumors in the eye is decreased by adding the GNPs prior to treatment. As a result, the dose to normal tissues decreases when the irradiation time is reduced. Furthermore, a comparison between the simulated data in an eye phantom made of water and eye phantom made of human eye composition, in the presence of GNPs, shows the significance of utilizing the composition of eye in ophthalmic brachytherapy dosimetry Also, defining the eye composition instead of water leads to more accurate calculations of GNPs radiation effects in ophthalmic brachytherapy dosimetry.

The relative biological effectiveness of I-125 and Pd-103

International Nuclear Information System (INIS)

Ling, C. Clifton; Li, William X.; Anderson, Lowell L.

1995-01-01

Purpose: To determine the relative biological effectiveness (RBE) of I-125 and Pd-103 relative to Co-60. Methods and Materials: A cell line REC:ras, derived from rat embryo cells, was used. Cells in exponential or plateau phase were irradiated at dose rates of about 0.07 Gy/h and 0.14 Gy/h. To circumvent the interface effect, cells were grown and irradiated on membranes made of cellulose acetate, which has an effective Z of 7.5. I-125 and Pd-103 seeds were placed in a custom designed template that yielded a homogeneous dose distribution in the plane of the cell culture. The dose rates of irradiation were measured by calibrated thermoluminescence dosimetry (TLD) chips. Results and Conclusions: Our measurements yielded an RBE of about 1.4 for I-125 at dose rates of about 0.07 Gy/h, and an RBE of about 1.9 for Pd-103 at dose rates of about 0.07 Gy/h and 0.14 Gy/h. The RBE of I-125 is similar to those measured by other investigators, the RBE for Pd-103 is being reported for the first time

The american brachytherapy society recommendations for permanent prostate brachytherapy postimplant dosimetric analysis

International Nuclear Information System (INIS)

Nag, Subir; Bice, William; Wyngaert, Keith de; Prestidge, Bradley; Stock, Richard; Yu Yan

2000-01-01

Purpose: The purpose of this report is to establish guidelines for postimplant dosimetric analysis of permanent prostate brachytherapy. Methods: Members of the American Brachytherapy Society (ABS) with expertise in prostate dosimetry evaluation performed a literature review and supplemented with their clinical experience formulated guidelines for performing and analyzing postimplant dosimetry of permanent prostate brachytherapy. Results: The ABS recommends that postimplant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy for optimal patient care. At present, computed tomography (CT)-based dosimetry is recommended, based on availability cost and the ability to image the prostate as well as the seeds. Additional plane radiographs should be obtained to verify the seed count. Until the ideal postoperative interval for CT scanning has been determined, each center should perform dosimetric evaluation of prostate implants at a consistent postoperative interval. This interval should be reported. Isodose displays should be obtained at 50%, 80%, 90%, 100%, 150%, and 200% of the prescription dose and displayed on multiple cross-sectional images of the prostate. A dose-volume histogram (DVH) of the prostate should be performed and the D 90 (dose to 90% of the prostate gland) reported by all centers. Additionally, the D 80, D 100, the fractional V 80, V 90, V 100, V 150, and V 200, (i.e., the percentage of prostate volume receiving 80%, 90%, 100%, 150%, and 200% of the prescribed dose, respectively), the rectal, and urethral doses should be reported and ultimately correlated with clinical outcome in the research environment. On-line real-time dosimetry, the effects of dose heterogeneity, and the effects of tissue heterogeneity need further investigation. Conclusion: It is essential that postimplant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy. Guidelines were established for the performance

Disease-related effects of perioperative blood transfusions associated with 125I seed implantation for prostate carcinoma

International Nuclear Information System (INIS)

Petersen, J.P.; Schellhammer, P.F.; el-Mahdi, A.M.

1990-01-01

In some retrospective studies perioperative transfusions during oncologic surgery have been shown to decrease the time interval between surgery and local and/or distant recurrence of cancer. This study examines the disease-related effect, if any, of perioperative blood transfusions among 108 patients with localized carcinoma of the prostate treated by radioactive iodine-125 seed implantation of the prostate and lymphadenectomy. When all subjects were analyzed, there was no statistical difference of local and distant failure between the transfused and nontransfused groups. Patients with well-differentiated tumors had statistically fewer local recurrences (0% vs 22%, p = 0.036) if they were transfused perioperatively. However, the difference in distant metastases (0% vs 11%) was not statistically significant (p = 0.21). In contrast, patients with moderately and poorly differentiated disease receiving transfusions had more local recurrences and metastases, though this was not statistically significant. Our data suggest that there is no obvious evidence that perioperative blood transfusions have an adverse effect on local recurrence or distant metastases for iodine-125 seed implantation of carcinoma of the prostate

SU-E-T-12: A Comparative Dosimetric Study of Pre and Post Prostate Iodine-125 Permanent Seed Implants

Energy Technology Data Exchange (ETDEWEB)

Liu, X; Rahimian, J; Goy, B; Cosmatos, H; Qian, Y [Kaiser Permanente, Los Angeles, CA (United States)

2015-06-15

Purpose: Post-implant dosimetry has become the gold standard for prostate implant evaluation. The goal of this research is to compare the dosimetry between pre-plan and post-plan in permanent prostate seed implant brachytherapy. Methods: A retrospective study of 91 patients treated with Iodine-125 prostate seed implant between year 2012∼2014 were performed. All plans were created using a VariSeed 8.0 planning system. Pre-plan ultrasound images were acquired using 0.5 cm slice thickness. Post-plan CT images acquired about 1–4 weeks after implant, fused with the preplan ultrasound images. The prostate and urethra contours were generated using the fusion of ultrasound and CT images. Iodine-125 seed source activities varied between 0.382 to 0.414 mCi per seed. The loading patterns varied slightly between patients depending on the prostate size. Statistical analysis of pre and post plans for prostate and urethra volumes, V100%, V150% and D90, and urethra D10 were performed and reported. Results: The pre and post implant average prostate size was 36.90cc vs. 38.58cc; V100% was 98.33% vs. 96.89%; V150% was 47.09% vs. 56.95%; D90 was 116.35Gy vs. 116.12Gy, urethra volume was 1.72cc vs. 1.85cc, urethra D10% was 122.0% vs. 135.35%, respectively. There was no statistically significant difference between the pre and post-plan values for D90(p-value=0.43). However, there are significant differences between other parameters most likely due to post surgical edema; prostate size (p-value= 0.00015); V100% (p-value=3.7803E-07); V150% (p-value=1.49E-09); urethra volume (p-value= 2.77E-06); Urethra D10 (p-value=7.37E-11). Conclusion: The post-plan dosimetry using CT image set showed similar D90 dose coverage to the pre-plan using the ultrasound image dataset. The study showed that our prostate seed implants have consistently delivered adequate therapeutic dose to the prostate while sparing urethra. Future studies to correlate dose versus biochemical response using patients’ PSA

Source strength verification and quality assurance of preloaded brachytherapy needles using a CMOS flat panel detector

Energy Technology Data Exchange (ETDEWEB)

Golshan, Maryam, E-mail: maryam.golshan@bccancer.bc.ca [Department of Physics, University of British Columbia, Vancouver, British Columbia V6T1Z1, Canada and Department of Medical Physics, Vancouver Center, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4E6 (Canada); Spadinger, Ingrid [Department of Medical Physics, Vancouver Center, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4E6 (Canada); Chng, Nick [Department of Medical Physics, Center for the North, British Columbia Cancer Agency, Prince George, British Columbia V2M 7E9 (Canada)

2016-06-15

Purpose: Current methods of low dose rate brachytherapy source strength verification for sources preloaded into needles consist of either assaying a small number of seeds from a separate sample belonging to the same lot used to load the needles or performing batch assays of a subset of the preloaded seed trains. Both of these methods are cumbersome and have the limitations inherent to sampling. The purpose of this work was to investigate an alternative approach that uses an image-based, autoradiographic system capable of the rapid and complete assay of all sources without compromising sterility. Methods: The system consists of a flat panel image detector, an autoclavable needle holder, and software to analyze the detected signals. The needle holder was designed to maintain a fixed vertical spacing between the needles and the image detector, and to collimate the emissions from each seed. It also provides a sterile barrier between the needles and the imager. The image detector has a sufficiently large image capture area to allow several needles to be analyzed simultaneously.Several tests were performed to assess the accuracy and reproducibility of source strengths obtained using this system. Three different seed models (Oncura 6711 and 9011 {sup 125}I seeds, and IsoAid Advantage {sup 103}Pd seeds) were used in the evaluations. Seeds were loaded into trains with at least 1 cm spacing. Results: Using our system, it was possible to obtain linear calibration curves with coverage factor k = 1 prediction intervals of less than ±2% near the centre of their range for the three source models. The uncertainty budget calculated from a combination of type A and type B estimates of potential sources of error was somewhat larger, yielding (k = 1) combined uncertainties for individual seed readings of 6.2% for {sup 125}I 6711 seeds, 4.7% for {sup 125}I 9011 seeds, and 11.0% for Advantage {sup 103}Pd seeds. Conclusions: This study showed that a flat panel detector dosimetry system

The preparation of 125I - gastrin I and 125 - minigastrin for medical diagnostics

International Nuclear Information System (INIS)

Byszewska-Szpocinska, E.; Markiewicz, A.

2002-01-01

Gastrin I G-17 and minigastrin G-13 were iodinated using direct methods with chloramin T and iodogen procedures and by indirect method with Bolton-Hunter reagent. 125 I - gastrin and 1 25 I - minigastrin were isolated from the iodination mixtures by gel filtration on Sephadex G-10 and Sephadex G-25 (PD-10 column) and by HPLC system (Lichrospher WP-300-RP-18 column). Radiochemical purity was shown by HPLC also. It was confirmed that iodogen procedure is the best for iodination of these peptides. 125 I - gastrin I obtained by this method with specific activity 80 μCi/nmol was homogeneous but iodination to higher specific activity (440μCi/nmol) caused appearance of two subfractions. 125 I - minigastrin with high and low specific activity were isolated by HPLC as the two forms (subfractions). It was shown that high performance liquid chromatography (HPLC) was the best method for isolation and purification of 125 I - gastrin I and 125 I - minigastrin. (author)