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Sample records for seed implant retention

  1. 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.

  2. High Retention and Safety of Percutaneously Implanted Endovascular Embolization Coils as Fiducial Markers for Image-Guided Stereotactic Ablative Radiotherapy of Pulmonary Tumors

    International Nuclear Information System (INIS)

    Hong, Julian C.; Yu Yao; Rao, Aarti K.; Dieterich, Sonja; Maxim, Peter G.; Le, Quynh-Thu; Diehn, Maximilian; Sze, Daniel Y.; Kothary, Nishita; Loo, Billy W.

    2011-01-01

    Purpose: To compare the retention rates of two types of implanted fiducial markers for stereotactic ablative radiotherapy (SABR) of pulmonary tumors, smooth cylindrical gold 'seed' markers ('seeds') and platinum endovascular embolization coils ('coils'), and to compare the complication rates associated with the respective implantation procedures. Methods and Materials: We retrospectively analyzed the retention of percutaneously implanted markers in 54 consecutive patients between January 2004 and June 2009. A total of 270 markers (129 seeds, 141 coils) were implanted in or around 60 pulmonary tumors over 59 procedures. Markers were implanted using a percutaneous approach under computed tomography (CT) guidance. Postimplantation and follow-up imaging studies were analyzed to score marker retention relative to the number of markers implanted. Markers remaining near the tumor were scored as retained. Markers in a distant location (e.g., pleural space) were scored as lost. CT imaging artifacts near markers were quantified on radiation therapy planning scans. Results: Immediately after implantation, 140 of 141 coils (99.3%) were retained, compared to 110 of 129 seeds (85.3%); the difference was highly significant (p < 0.0001). Of the total number of lost markers, 45% were reported lost during implantation, but 55% were lost immediately afterwards. No additional markers were lost on longer-term follow-up. Implanted lesions were peripherally located for both seeds (mean distance, 0.33 cm from pleural surface) and coils (0.34 cm) (p = 0.96). Incidences of all pneumothorax (including asymptomatic) and pneumothorax requiring chest tube placement were lower in implantation of coils (23% and 3%, respectively) vs. seeds (54% and 29%, respectively; p = 0.02 and 0.01). The degree of CT artifact was similar between marker types. Conclusions: Retention of CT-guided percutaneously implanted coils is significantly better than that of seed markers. Furthermore, implanting coils is at

  3. Implant retention systems for implant-retained overdentures.

    Science.gov (United States)

    Laverty, D P; Green, D; Marrison, D; Addy, L; Thomas, M B M

    2017-03-10

    Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.

  4. Dense understory dwarf bamboo alters the retention of canopy tree seeds

    Science.gov (United States)

    Qian, Feng; Zhang, Tengda; Guo, Qinxue; Tao, Jianping

    2016-05-01

    Tree seed retention is thought to be an important factor in the process of forest community regeneration. Although dense understory dwarf bamboo has been considered to have serious negative effects on the regeneration of forest community species, little attention has been paid to the relationship between dwarf bamboo and seed retention. In a field experiment we manipulated the density of Fargesia decurvata, a common understory dwarf bamboo, to investigate the retention of seeds from five canopy tree species in an evergreen and deciduous broad-leaved mixed forest in Jinfoshan National Nature Reserve, SW China. We found that the median survival time and retention ratio of seeds increased with the increase in bamboo density. Fauna discriminately altered seed retention in bamboo groves of different densities. Arthropods reduced seed survival the most, and seeds removed decreased with increasing bamboo density. Birds removed or ate more seeds in groves of medium bamboo density and consumed fewer seeds in dense or sparse bamboo habitats. Rodents removed a greater number of large and highly profitable seeds in dense bamboo groves but more small and thin-husked seeds in sparse bamboo groves. Seed characteristics, including seed size, seed mass and seed profitability, were important factors affecting seed retention. The results suggested that dense understory dwarf bamboo not only increased seeds concealment and reduced the probability and speed of seed removal but also influenced the trade-off between predation and risk of animal predatory strategies, thereby impacting the quantity and composition of surviving seeds. Our results also indicated that dense understory dwarf bamboo and various seed characteristics can provide good opportunities for seed storage and seed germination and has a potential positive effect on canopy tree regeneration.

  5. 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

  6. 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

  7. 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

  8. First symposium seed implant 125I and high rate of prostate

    International Nuclear Information System (INIS)

    2012-01-01

    The First symposium seed implant 125 I and high rate of prostate, was organized by the Marie Curie Foundation, between the 12 to april 2012, in the Cordoba city of Argentina. In this event were presented several documents in different topics: patients selection for impacts of 125 I seeds; high doses radiation in radiotherapy; brachytherapy for prostate cancer; prostate implant technique with 125 I seeds; implant dosimetric aspects; radioprotection of 125 I seeds.

  9. 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

  10. Mandibular Overdentures Retained by Two Mini-Implants: A Seven-Year Retention and Satisfaction Study.

    Science.gov (United States)

    Catalán, Alfonso; Martínez, Alejandra; Marchesani, Francisco; González, Urcesino

    2016-07-01

    Patients with atrophic edentulous ridges generally have problems with retention, therapeutic satisfaction, and comfort with their complete dentures. An alternative treatment to assist in improving retention and stability involves the use of mini-implants. The aim of this study was to evaluate the retention of mandibular overdentures connected to two mini-implants and overall patient satisfaction with them. Seven patients with atrophic mandibular ridges (Type 4D Misch classification), aged 62 to 74 years old were rehabilitated with complete dentures. In each patient, two mini-implants measuring 15 or 13 mm in length and 1.8 mm in diameter were placed. After 15 days, overdentures were connected to the mini-implants with O-ring attachments. In each patient, retention of the overdentures was measured, and a survey of therapeutic satisfaction before and after connection to the mini-implants was administered. Prosthesis retention was measured with a digital dynamometer at 1 month, 6 months, and 2, 3, 5, and 7 years after mini-implant placement. Patient satisfaction was assessed with a survey. Data were analyzed with Student's t-test (satisfaction survey) and the Friedman test (retention measurements and satisfaction survey). The initial retention values (0.34 to 0.63 N without mini-implants) varied significantly (p ≤ 0.050). These values were less than the subsequent measurements of 3.92 to 9.64 N, taken after placement of the mini-implants and connecting them to the dentures. Satisfaction was good to very good over the 7-year observation period. Mucosa and peri-implant bone showed no pathological changes. In this limited sample size clinical study the results indicated that after connecting mandibular overdentures to two mini-implants, patient satisfaction significantly increased and retention significantly improved during the 7-year observation period. © 2015 by the American College of Prosthodontists.

  11. 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)

  12. Retentiveness of implant-supported metal copings using different luting agents

    Directory of Open Access Journals (Sweden)

    Farahnaz Nejatidanesh

    2012-01-01

    Full Text Available Background: With regard to potential retrievability of cement-retained implant restorations, the retentive strength of the luting agents is critical. The aim of this study was to evaluate the retention values of implant-supported metal copings using different luting agents. Materials and Methods: Twenty ITI implant analogs and solid abutments of 5.5-mm height were embedded vertically in autopolymerizing acrylic resin blocks. Metal copings with a loop on the occlusal surface were fabricated using base metal alloy (Rexillium III. The copings were luted using eight cements with different retention mechanisms (Panavia F2.0, Fuji Plus, Fleck′s, Poly F, Fuji I, Temp Bond, GC-free eugenol, and TempSpan under static load of 5 kg (n=10. All specimens were incubated at 37°C for 24 hours, conditioned in artificial saliva for 7 days and thermocycled for 5000 cycles (5-55°C. The dislodging force was measured using a universal testing machine at a crosshead speed of 5 mm/min. Statistical analyses were performed using Kruskal-Wallis (α=0.05 and Mann-Whitney tests with Bonferroni correction (α=0.001. Results: Fuji Plus and TempSpan had the highest and the least mean retentive strength, respectively (320.97±161.47, 3.39±2.33. There was no significant difference between Fuji Plus, Fleck′s, Ploy F, and Panavia F2.0. These cements were superior to provisional cements and Fuji I (P<0.001 which showed statistically same retentive strength. Conclusion: Within the conditions of this study, the resin modified glass ionomer, zinc phosphate, zinc polycarboxylate, and Panavia F2.0 had statistically the same retentive quality and are recommended for definitive cementation of single implant-supported restorations. The provisional cements and glass ionomer may allow retrievability of these restorations.

  13. Pulmonary embolization of permanently implanted radioactive palladium-103 seeds for carcinoma of the prostate

    International Nuclear Information System (INIS)

    Nag, Subir; Vivekanandam, Singhavajhala; Martinez-Monge, Rafael

    1997-01-01

    Purpose: It has been reported that permanently implanted iodine-125 seeds can embolize to the lungs. There is little data on the embolization of palladium-103 seeds. The purpose of this study is to collect and evaluate data on the embolization of Pd-103 seeds. Methods and Materials: The records of 112 patients implanted with Pd-103 for carcinoma of the prostate were reviewed to systemically study the incidence and dynamics of pulmonary embolism of Pd-103 seeds. Five patients had no postoperative chest radiograph and were thus excluded, leaving 107 patients for review. Results: Chest radiographs of 19 of the 107 patients showed embolized seeds in the lungs (18%). Two patients had three seeds each, nine patients had two seeds each; and in the remaining eight patients, a single seed migrated to the lungs. The seeds migrated mainly (84%) to the lower lobes. None of the eight patients who had their first postoperative chest radiograph on the day of the implant showed any embolized seeds. The embolized seed appeared only on subsequent chest radiographs taken 27 to 40 days later. Ten of the other 11 patients who had their first radiograph 1 to 97 days after brachytherapy had embolized seeds on their first chest radiograph. In the other patient, the embolized seed appeared only on a subsequent chest radiograph taken after 127 days. There were no clinical pulmonary or cardiac effects evident on routine follow-up of these patients with pulmonary embolized seeds. Conclusion: Embolization of Pd-103 seeds to the lungs after implantation for carcinoma of the prostate is an unusual event. In this study only 0.3% of the seeds implanted migrated to the lungs. Although it was previously thought that pulmonary seed migration mainly occurred on the day of brachytherapy, our experience shows that seeds usually migrated to the lungs after the day of the implant. There were no clinical pulmonary or cardiac effects attributable to embolized seeds in the lungs on routine follow-up

  14. 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)

  15. Dosimetry study of three-dimensional print template-guided precision 125I seed implantation

    Directory of Open Access Journals (Sweden)

    Zhang Hongtao

    2016-01-01

    Conclusions: The postplan and preplan dose parameters of 3D print template-guided seed implantation were nearly consistent. The dose parameters of template group superior to the traditional group. The seeds can be implanted accurately with 3D print template.

  16. Effects of seed migration on post-implant dosimetry of prostate brachytherapy

    International Nuclear Information System (INIS)

    Gao, M.; Wang, J. Z.; Nag, S.; Gupta, N.

    2007-01-01

    Brachytherapy using permanent seed implants has been an effective treatment for prostate cancer. However, seeds will migrate after implant, thus making the evaluation of post-implant dosimetry difficult. In this study, we developed a computer program to simulate seed migration and analyzed dosimetric changes due to seed migration at various migration amounts. The study was based on 14 patients treated with Pd-103 at the James Cancer Hospital. Modeling of seed migration, including direction, distance as well as day of migration, was based on clinical observations. Changes of commonly used dosimetric parameters as a function of migration amount (2, 4, 6 mm respectively), prostate size (from 20 to 90 cc), and prostate region (central vs peripheral) were studied. Change of biological outcome (tumor control probability) due to migration was also estimated. Migration reduced prostate D90 to 99±2% of original value in 2 mm migration, and the reduction increased to 94±6% in 6 mm migration. The reduction of prostate dose led to a 14% (40%) drop in the tumor control probability for 2 mm (6 mm) migration, assuming radiosensitive tumors. However, migration has less effect on a prostate implanted with a larger number of seeds. Prostate V100 was less sensitive to migration than D90 since its mean value was still 99% of original value even in 6 mm migration. Migration also showed a different effect in the peripheral region vs the central region of the prostate, where the peripheral mean dose tended to drop more significantly. Therefore, extra activity implanted in the peripheral region during pre-plan can be considered. The detrimental effects of migration were more severe in terms of increasing the dose to normal structures, as rectum V50 may be 70% higher and urethra V100 may be 50% higher in the case of 6 mm migration. Quantitative knowledge of these effects is helpful in treatment planning and post-implant evaluation

  17. 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)

  18. The surgical viability and radiological monitoring of brain implants of bioactive micro-seeds in an animal model

    International Nuclear Information System (INIS)

    Silva, Giane X.O.; Campos, Tarcisio Passos Ribeiro de; Siqueira, Savio Lana; Maciel, Marcelo B.

    2005-01-01

    The interstitial implant is a therapeutic modality in brachytherapy of the head and neck. Presently, the seeds implanted in tumors in the central nervous system are metallic I-125. After the full emission of the radionuclide, the seed remains inert in the implanted area. Bioactive ceramic seeds have been prepared for this research group incorporating Sm-152 to be active in Sm-153. The main goal of the present study is the development of a the surgical technique for implanting the biodegradable radioactive micro-seeds in the brains of rabbits, as well as the observation of the clinical reactions of the animal after implantation of two sets of three seeds. The surgical procedure consisted of performing two separate perforations 10 mm from each other in the skull, permitting the implantation of two groups of three seeds, totaling six seeds. The results of the pilot study showed the effectiveness of the surgical procedure and of the biocompatibility of the seeds and the lack of presence of adverse reactions, functional sequels, or inflammation in a follow up 50 days post-surgery. Such seeds of reduced volume, 0.2 x 1.6 mm, could be monitored by computerized tomography 30 days after implanting. (author)

  19. SU-F-T-39: Comparing Nomograms for Ordering of Palladium-103 Seeds for Dynamic Intraoperative Prostate Seed Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P; Wang, L; Riegel, A [Northwell Health, Lake Success, NY (United States)

    2016-06-15

    Purpose: Several nomograms exist for the purpose of ordering palladium- 103 seeds for permanent prostate seed implants. Excess seeds pose additional radiation safety risks and increase the cost of care. This study compared three seed ordering nomograms with seed counts from dynamic intra-operative PSI to determine (1) the cause of excess seeds and (2) the optimal nomogram for our institution. Methods: Pre-operative and intra-operative clinical data were collected for 100 Gy (n=151) and 125 Gy (n=224) prostate seed implants. The number of implanted seeds which would have given D90=100% was normalized to that criteria and seed strength of 2U. This was plotted against intra-operative prostate volume and compared to two previously published nomograms and an in-house nomogram. A linear fit was produced and confidence intervals were calculated. The causes of excess seeds were assessed by comparing pre- and intra-operative prostate volumes, variability of D90 around 100%, and variance of seed strength from 2U. Results: Of the 375 total cases, 97.6% had excess seeds. On average, 27.17±12.91% of ordered seeds were wasted. Of this percentage, 6.98±5.47% of excess seeds were due to overestimation of pre-operative prostate volume, 1.10±0.88% were due to D90<100%, 1.17±0.67% were due to seed strength over 2U, and 17.36±7.79% could not be directly attributed to a specific reason. The latter percentage may be due to overestimation of the in-house nomogram. Two of three nomograms substantially overestimated the number of seeds required. The third nomogram underestimated the required seed number for smaller prostate treatment volume. A linear fit to the clinical data was derived and 99.9% confidence intervals were calculated. Conclusion: Over 85% of clinical cases wasted over 15% of ordered seeds. Two of three nomograms overestimated the required number of seeds. The upper 99.9% C.I. of the clinical data may provide a more reasonable nomogram for Pd-103 seed ordering.

  20. SU-F-T-39: Comparing Nomograms for Ordering of Palladium-103 Seeds for Dynamic Intraoperative Prostate Seed Implantation

    International Nuclear Information System (INIS)

    Taylor, P; Wang, L; Riegel, A

    2016-01-01

    Purpose: Several nomograms exist for the purpose of ordering palladium- 103 seeds for permanent prostate seed implants. Excess seeds pose additional radiation safety risks and increase the cost of care. This study compared three seed ordering nomograms with seed counts from dynamic intra-operative PSI to determine (1) the cause of excess seeds and (2) the optimal nomogram for our institution. Methods: Pre-operative and intra-operative clinical data were collected for 100 Gy (n=151) and 125 Gy (n=224) prostate seed implants. The number of implanted seeds which would have given D90=100% was normalized to that criteria and seed strength of 2U. This was plotted against intra-operative prostate volume and compared to two previously published nomograms and an in-house nomogram. A linear fit was produced and confidence intervals were calculated. The causes of excess seeds were assessed by comparing pre- and intra-operative prostate volumes, variability of D90 around 100%, and variance of seed strength from 2U. Results: Of the 375 total cases, 97.6% had excess seeds. On average, 27.17±12.91% of ordered seeds were wasted. Of this percentage, 6.98±5.47% of excess seeds were due to overestimation of pre-operative prostate volume, 1.10±0.88% were due to D90<100%, 1.17±0.67% were due to seed strength over 2U, and 17.36±7.79% could not be directly attributed to a specific reason. The latter percentage may be due to overestimation of the in-house nomogram. Two of three nomograms substantially overestimated the number of seeds required. The third nomogram underestimated the required seed number for smaller prostate treatment volume. A linear fit to the clinical data was derived and 99.9% confidence intervals were calculated. Conclusion: Over 85% of clinical cases wasted over 15% of ordered seeds. Two of three nomograms overestimated the required number of seeds. The upper 99.9% C.I. of the clinical data may provide a more reasonable nomogram for Pd-103 seed ordering.

  1. 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)

  2. Retention Strength of Conical Welding Caps for Fixed Implant-Supported Prostheses.

    Science.gov (United States)

    Nardi, Diego; Degidi, Marco; Sighinolfi, Gianluca; Tebbel, Florian; Marchetti, Claudio

    This study evaluated the retention strength of welding caps for Ankylos standard abutments using a pull-out test. Each sample consisted of an implant abutment and its welding cap. The tests were performed with a Zwick Roell testing machine with a 1-kN load cell. The retention strength of the welding caps increased with higher abutment diameters and higher head heights and was comparable or superior to the values reported in the literature for the temporary cements used in implant dentistry. Welding caps provide a reliable connection between an abutment and a fixed prosthesis without the use of cement.

  3. Effect of Abutment Modification and Cement Type on Retention of Cement-Retained Implant Supported Crowns

    OpenAIRE

    Farzin, Mitra; Torabi, Kianoosh; Ahangari, Ahmad Hasan; Derafshi, Reza

    2014-01-01

    Objective: Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations. Materials and Method: Two prefabricated abutments were attached to their corresponding analogs and embedded in an ac...

  4. Biologically effective dose (BED) for interstitial seed implants containing a mixture of radionuclides with different half-lives

    International Nuclear Information System (INIS)

    Chen Zhe; Nath, Ravinder

    2003-01-01

    Purpose: To develop a tool for evaluating interstitial seed implants that contain a mixture of radionuclides with different half-lives and to demonstrate its utility by examining the clinical implications of prescribing to an isodose surface for such an implant. Methods and Materials: A linear-quadratic model for continuous low dose rate irradiation was developed for permanent implants containing a mixture of radionuclides. Using a generalized equation for the biologically effective dose (BED), the effects of cell proliferation and sublethal damage repair were examined systematically for implants containing a mixture of radionuclides. A head-and-neck permanent seed implant that contained a mixture of 125 I and 103 Pd seeds was used to demonstrate the utility of the generalized BED. Results: An equation of BED for implants containing a mixture of radionuclides with different half-lives was obtained. In such an implant, the effective cell kill was shown to depend strongly on the relative dose contributions from each radionuclide type; dose delivered by radionuclides with shorter half-life always resulted in more cell kill for any given sublethal damage repair and cell proliferation rates. Application of the BED formula to an implant containing a mixture of 125 I and 103 Pd seeds demonstrates that the conventional dose prescription to an isodose surface is not unique for such an implant. When the prescription dose was based on existing clinical experience of using 125 I seeds alone, mixing 103 Pd seeds with 125 I seeds would increase the cell kill. On the other hand, if the prescription dose were based on existing clinical experience of using 103 Pd seeds alone, mixing 125 I seeds with 103 Pd seeds in the same implant would create radiobiologically 'cold' spots (i.e., an increase in cell survival) at locations where a major portion of the prescription dose is contributed by the 125 I seeds. For fast-growing tumors, these 'cold' spots can become significant

  5. Lithium concentration dependence of implanted helium retention in lithium silicates

    Energy Technology Data Exchange (ETDEWEB)

    Szocs, D.E., E-mail: szocsd@rmki.kfki.h [KFKI Research Institute for Particle and Nuclear Physics, H-1525 Budapest, P.O. Box 49 (Hungary); Szilagyi, E.; Bogdan, Cs.; Kotai, E. [KFKI Research Institute for Particle and Nuclear Physics, H-1525 Budapest, P.O. Box 49 (Hungary); Horvath, Z.E. [Research Institute for Technical Physics and Materials Science, H-1525 Budapest, P.O. Box 49 (Hungary)

    2010-06-15

    Helium ions of 500 keV were implanted with a fluence of 1.4 x 10{sup 17} ion/cm{sup 2} into various lithium silicates to investigate whether a threshold level of helium retention exists in Li-containing silicate ceramics similar to that found in SiO{sub x} in previous work. The composition and phases of the as prepared lithium silicates were determined by proton backscattering spectrometry (p-BS) and X-ray diffraction (XRD) methods with an average error of {+-}10%. Electrostatic charging of the samples was successfully eliminated by wrapping the samples in Al foil. The amounts of the retained helium within the samples were determined by subtracting the non-implanted spectra from the implanted ones. The experimental results show a threshold in helium retention depending on the Li concentration. Under 20 at.% all He is able to escape from the material; at around 30 at.% nearly half of the He, while over 65 at.% all implanted He is retained. With compositions expressed in SiO{sub 2} volume percentages, a trend similar to those reported of SiO{sub x} previously is found.

  6. Investigation on curative efficacy for malignant tumor by implantation '125I permanent brachytherapy seeds

    International Nuclear Information System (INIS)

    Hu Shu; Gao Zhou; Jia Shaowei; Cheng Xianyi; Chen Junhui; Yin Weihua; Sun Desheng

    2011-01-01

    Twenty inpatients suffered from malignant tumors with twenty-four lesions were treated with 125 I permanent brachytherapy seed in Peking University Shenzhen Hospital, and the feasibility, curative effect and adverse effect of the treatment were observed. Before 125 I seeds implantation, the three-dimensional treatment planning was preconcerted. There were two methods to implant 125 I seeds. One was to insert the seeds in the location of residual focus and metastatic lesions of the tumors directly in ordinary operations or through laparoscopy under general anesthesia. The other w as to implant the seeds into the tumors through percutaneous needles by the guidance of CT scanning or color doppler ultrasonography under local anesthesia. The implantations for all of the 20 patients (24 lesions) were performed successfully. During and one week after the implantation, the distributions of the planted seeds were approximately the same as the scheduled three-dimensional treatment planning, and no seed migration was found. Adverse reactions during and after the operation were slight and recovered after correlative treatments. Clinical symptoms were palliated and ser um tumor marker decreased to a different extent among most patients. The complete remission (CR) rate is 20.00% (4/20 patients ), the partial emission (PR) rate is 35.00% (7/20 patients), the stable disease (SD) rate is 30.00% (6/20 patients), the progressive disease (PD) rate is 15.00% (3/20 patients), and the overall response rate (CR + PR) is 53.33% (8 patients). 125 I seeds implantation for targeted therapy is convenient, safe and effective on malignant tumor, and is well worth advanced application. (authors)

  7. A novel curvilinear approach for prostate seed implantation

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K.; Dicker, Adam P.; Hutapea, Parsaoran; Darvish, Kurosh; Yu Yan [Department of Radiation Oncology, Leo Jenkins Cancer Center, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834 (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Mechanical Engineering, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

    2012-04-15

    Purpose: A new technique called ''curvilinear approach'' for prostate seed implantation has been proposed. The purpose of this study is to evaluate the dosimetric benefit of curvilinear distribution of seeds for low-dose-rate (LDR) prostate brachytherapy. Methods: Twenty LDR prostate brachytherapy cases planned intraoperatively with VariSeed planning system and I-125 seeds were randomly selected as reference rectilinear cases. All the cases were replanned by using curved-needle approach keeping the same individual source strength and the volume receiving 100% of prescribed dose 145 Gy (V{sub 100}). Parameters such as number of needles, seeds, and the dose coverage of the prostate (D{sub 90}, V{sub 150}, V{sub 200}), urethra (D{sub 30}, D{sub 10}) and rectum (D{sub 5}, V{sub 100}) were compared for the rectilinear and the curvilinear methods. Statistical significance was assessed using two-tailed student's t-test. Results: Reduction of the required number of needles and seeds in curvilinear method were 30.5% (p < 0.001) and 11.8% (p < 0.49), respectively. Dose to the urethra was reduced significantly; D{sub 30} reduced by 10.1% (p < 0.01) and D{sub 10} reduced by 9.9% (p < 0.02). Reduction in rectum dose D{sub 5} was 18.5% (p < 0.03) and V{sub 100} was also reduced from 0.93 cc in rectilinear to 0.21 cc in curvilinear (p < 0.001). Also the V{sub 150} and V{sub 200} coverage of prostate reduced by 18.8% (p < 0.01) and 33.9% (p < 0.001), respectively. Conclusions: Significant improvement in the relevant dosimetric parameters was observed in curvilinear needle approach. Prostate dose homogeneity (V{sub 150}, V{sub 200}) improved while urethral dose was reduced, which might potentially result in better treatment outcome. Reduction in rectal dose could potentially reduce rectal toxicity and complications. Reduction in number of needles would minimize edema and thereby could improve postimplant urinary incontinence. This study indicates that the

  8. Factors predicting for postimplantation urinary retention after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Lee, Nancy; Wuu, C.-S.; Brody, Rachel; Laguna, Joe L.; Katz, Aaron E.; Bagiella, Emilia; Ennis, Ronald D.

    2000-01-01

    Purpose: Urinary retention requiring catheterization is a known complication among prostate cancer patients treated with permanent interstitial radioactive seed implantation. However, the factors associated with this complication are not well known. This study was conducted to determine these factors. Methods and Materials: Ninety-one consecutive prostate cancer patients treated with permanent interstitial implantation at our institution from 1996 to 1999 were evaluated. All patients underwent pre-implant ultrasound and postimplant CT volume studies. Isotopes used were 125 I (54 patients) or 103 Pd (37 patients). Twenty-three patients were treated with a combination of 45 Gy of external beam radiation therapy as well as seed implantation, of which only 3 patients were treated with 125 I. Mean pretreatment prostate ultrasound volume was 35.4 cc (range, 10.0-70.2 cc). The mean planning ultrasound target volume (PUTV) was 39.6 cc (range, 16.1-74.5 cc), whereas the mean posttreatment CT target volume was 55.0 cc (range, 20.2-116 cc). Patient records were reviewed to determine which patients required urinary catheterization for relief of urinary obstruction. The following factors were analyzed as predictors for urinary retention: clinical stage; Gleason score; prostate-specific antigen; external beam radiation therapy; hormone therapy; pre-implant urinary symptoms (asymptomatic/nocturia x 1 vs. more significant urinary symptoms); pretreatment ultrasound prostate volume; PUTV; PUTV within the 125%, 150%, 200%, 250%, 300% isodose lines; postimplant CT volume within the 125%, 150%, 200%, 250%, 300% isodose lines; D90; D80; D50; ratio of post-CT volume to the PUTV; the absolute change in volume between the CT volume and PUTV; number of needles used; activity per seed; and the total activity of the implant. Statistical analyses using logistic regression and χ2 were performed. Results: Eleven of 91 (12%) became obstructed. Significant factors predicting for urinary retention

  9. 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.

  10. Load-Bearing Capacity and Retention of Newly Developed Micro-Locking Implant Prosthetic System: An In Vitro Pilot Study

    Directory of Open Access Journals (Sweden)

    Jae-Won Choi

    2018-04-01

    Full Text Available The aim of this study was to introduce the newly developed micro-locking implant prosthetic system and to evaluate the resulting its characteristics. To evaluate load-bearing capacity, 25 implants were divided into five groups: external-hexagon connection (EH, internal-octagon connection (IO, internal-hexagon connection (IH, one-body implant (OB, micro-locking implant system (ML. The maximum compressive load was measured using a universal testing machine (UTM according to the ISO 14801. Retention was evaluated in two experiments: (1 a tensile test of the structure modifications of the components (attachment and implant and (2 a tensile test after cyclic loading (total 5,000,000 cycles, 100 N, 2 Hz. The load-bearing capacity of the ML group was not significantly different from the other groups (p > 0.05. The number of balls in the attachment and the presence of a hexagonal receptacle did not show a significant correlation with retention (p > 0.05, but the shape of the retentive groove in the implant post had a statistically significant effect on retention (p < 0.05. On the other hand, the retention loss was observed during the initial 1,000,000 cycles, but an overall constant retention was maintained afterward. Various preclinical studies on this novel micro-locking implant prosthetic system should continue so that it can be applied in clinical practice.

  11. Monte carlo simulation of penetration range distribution of ion beam with low energy implanted in plant seeds

    International Nuclear Information System (INIS)

    Huang Xuchu; Hou Juan; Liu Xiaoyong

    2009-01-01

    The depth and density distribution of V + ion beam implanted into peanut seed is simulated by the Monte Carlo method. The action of ions implanted in plant seeds is studied by the classical collision theory of two objects, the electronic energy loss is calculated by Lindhard-Scharff formulation. The result indicates that the depth of 200keV V + implanted into peanut seed is 5.57μm, which agrees with experimental results, and the model is appropriate to describe this interaction. This paper provides a computational method for the depth and density distribution of ions with low energy implanted in plant seeds. (authors)

  12. 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

  13. Dosimetric effects of edema in permanent prostate seed implants: a rigorous solution

    International Nuclear Information System (INIS)

    Chen Zhe; Yue Ning; Wang Xiaohong; Roberts, Kenneth B.; Peschel, Richard; Nath, Ravinder

    2000-01-01

    Purpose: To derive a rigorous analytic solution to the dosimetric effects of prostate edema so that its impact on the conventional pre-implant and post-implant dosimetry can be studied for any given radioactive isotope and edema characteristics. Methods and Materials: The edema characteristics observed by Waterman et al (Int. J. Rad. Onc. Biol. Phys, 41:1069-1077; 1998) was used to model the time evolution of the prostate and the seed locations. The total dose to any part of prostate tissue from a seed implant was calculated analytically by parameterizing the dose fall-off from a radioactive seed as a single inverse power function of distance, with proper account of the edema-induced time evolution. The dosimetric impact of prostate edema was determined by comparing the dose calculated with full consideration of prostate edema to that calculated with the conventional dosimetry approach where the seed locations and the target volume are assumed to be stationary. Results: A rigorous analytic solution on the relative dosimetric effects of prostate edema was obtained. This solution proved explicitly that the relative dosimetric effects of edema, as found in the previous numerical studies by Yue et. al. (Int. J. Radiat. Oncol. Biol. Phys. 43, 447-454, 1999), are independent of the size and the shape of the implant target volume and are independent of the number and the locations of the seeds implanted. It also showed that the magnitude of relative dosimetric effects is independent of the location of dose evaluation point within the edematous target volume. It implies that the relative dosimetric effects of prostate edema are universal with respect to a given isotope and edema characteristic. A set of master tables for the relative dosimetric effects of edema were obtained for a wide range of edema characteristics for both 125 I and 103 Pd prostate seed implants. Conclusions: A rigorous analytic solution of the relative dosimetric effects of prostate edema has been

  14. 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)

  15. The effect of inter-implant distance on retention and resistance to dislodging forces for mandibular implant-tissue-supported overdentures.

    Directory of Open Access Journals (Sweden)

    Farhad Tabatabaian

    2014-10-01

    Full Text Available The effect of inter-implant distance on retention and resistance of implant-tissue-supported overdentures is lacking in the literature. An in vitro study was performed to evaluate this effect for mandibular implant-tissue-supported overdentures retained by two ball attachments.An acrylic cast of an edentulous mandible was fabricated. Three pairs of implants were symmetrically placed at both sides of the midline. The inter-implant distance was 10, 25, and 35 millimeters in positions A, B and C, respectively. A framework simulating the overdenture was fabricated on the cast. Six attachment housings were placed within the overdenture. For each sample, two ball abutments were screwed onto the implant pairs and two pink nylon inserts were seated in their respective attachment housings. The samples were tested in three groups of 15 (A, B, and C. The testing machine applied tensile dislodging forces and peak loads were measured in three directions: vertical, oblique, and anterior-posterior. A one-way ANOVA followed by Tukey's HSD was used to determine groups that were significantly different. Tests were carried out at 0.05 level of significance.Peak loads for the anterior-posteriorly directed dislodging forces were significantly the highest for group C (P0.05.Inter-implant distance did not affect the vertical retention and oblique resistance of mandibular implant-tissue-supported overdentures; however, it affected anterior-posterior resistance.

  16. 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)

  17. Retention systems for extraoral maxillofacial prosthetic implants: a critical review.

    Science.gov (United States)

    Cobein, M V; Coto, N P; Crivello Junior, O; Lemos, J B D; Vieira, L M; Pimentel, M L; Byrne, H J; Dias, R B

    2017-10-01

    We describe the techniques available for retention of implant-supported prostheses: bar-clips, O-rings, and magnets. We present reported preferences and, although this is limited by the heterogeneity of methods used and patients studied, we hope we have identified the best retention systems for maxillofacial prosthetic implants. If practitioners know the advantages and disadvantages of each system, they can choose the most natural and comfortable prosthesis. We searched the PubMed and Scopus databases, and restricted our search to papers published 2001-13. MeSH terms used were Maxillofacial prosthesis and Craniofacial prosthesis OR Craniofacial prostheses. We found a total of 2630 papers, and after duplicates had been removed we analysed the rest and found 25 papers for review. Of these, 12 were excluded because they were case reports or non-systematic reviews. Of the remaining 13, 10 described group analyses and seemed appropriate to find practitioner's choices, as cited in the abstract (n=1611 prostheses). Three papers did not mention the type of prosthetic connection used, so were excluded. The most popular choices for different conditions were analysed, though the sites and retention systems were not specified in all 10 papers. The bar-clip system was the most used in auricular (6/10 papers) and nasal prostheses (4/10). For the orbital region, 6/10 favoured magnets. Non-osseointegrated mechanical or adhesive retention techniques are the least expensive and have no contraindications. When osseointegrated implants are possible, each facial region has a favoured system. The choice of system is influenced by two factors: standard practice and the abilities of the maxillofacial surgeon and maxillofacial prosthetist. Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Retention system for implant-supported dentures used by brazilian dentists who work in implant dentistry

    OpenAIRE

    Saturnino Aparecido Ramalho; Fábio Pontes Dantas

    2010-01-01

    Objective: To provide the dentists with support in the choice of the cement or screw type of retention for implant-supported dentures, according to the patient’s problem. Methods: An opinion questionnaire was applied to a sample of 468 participants, all dentists working in the field of Implant Dentistry, of whom 272 (58.1%) participated in the 4th International Congress of Osseointegration of APCD, held in São Paulo (SP) from 6 to 9 May 2004, 119 (25.4%) participated in the 2nd International ...

  19. Dosimetry consequences of the accuracy at the position of the seeds in a seeds implant of I-125 in prostate

    International Nuclear Information System (INIS)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-01-01

    The quality control of equipment used to carry out implants of seeds of low rate in prostate, van destined to watch, the activity of seeds and the calculation of planning both positioning them on the inside of the patient. The objective of this work is, using the Nucletron Spot Pro and SeedSelectron, rating dosimetry possible consequences related to the position of the seeds. (Author)

  20. Factors influencing upon the incidence of seed migration in I-125 seed transperineal prostate implantation

    International Nuclear Information System (INIS)

    Itami, Jun; Onishi, Kayoko; Kanemura, Mikio

    2005-01-01

    Transperineal I-125 seed brachytherapy for prostate cancer is rapidly expanding in Japan. Seed migrations to lung and abdomen are well known complication in the seed brachytherapy. The rate of incidence and the predisposing factors were studied. From April 2004 through January 2005, 36 patients underwent transperineal I-125 seed brachytherapy for prostate cancer. In all patients loose I-125 seeds were inserted with Mick applicator according to modified peripheral loading pattern. One day, 1 week, and 1 month after the procedure, posteroanterior and lateral chest X-rays and abdominal X-ray were performed. Abdominal and chest seed migrations were seen in 11 (30.6%) and 14 (38.9%) patients, respectively. In total, 20 patients (55.6%) showed seed migrations. Forty-two I-125 seeds migrated out of 2,508 implanted seeds. Most of the migrations were seen until 1 month after the procedure. The preplanned number of the extraprostatic seeds had a statistically significant influence upon the incidence of seed migration. Seed migration is not a rare phenomenon in transperineal I-125 seed brachytherapy for prostate cancer. To confirm seed migration, X-ray examinations 1 month after the procedure are suited. At the preplanning, the number of extraprostatic seeds should be limited to minimal to decrease the incidence of seed migration. In future, the introduction of linked I-125 seeds is preferred. (author)

  1. 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.

  2. Retention and Stability of Implant-Retained Mandibular Overdentures Using Different Types of Resilient Attachments: An In Vitro Study.

    Science.gov (United States)

    ELsyad, Moustafa Abdou; Agha, Nora Nory; Habib, Ahmed Ali

    2016-01-01

    The aim of this study was to evaluate and compare the retention and stability of mandibular implant overdentures using different types of resilient attachments. Two implant analogs were inserted in the canine areas of an acrylic edentulous mandibular model. A metal-reinforced experimental overdenture was constructed and connected to the implant analogs (on two occasions) using either resilient telescopic or Locator attachments. Locators were divided into three subgroups according to the degree of retention of the male nylon insert: Locator extra-light retention (blue insert), Locator light retention (pink insert), and Locator medium retention (transparent insert). Vertical and oblique (anterior, posterior, and lateral) dislodging forces were measured at the beginning of the study (initial retention) and after 540 cycles of denture insertion and removal (final retention). For all dislodging forces, Locator medium recorded the highest initial and final retention. Telescopic attachments recorded the lowest retention during vertical and anterior dislodging, and Locator extra-light recorded the lowest retention during lateral and posterior dislodging. For all types of Locator attachments, anterior dislodging recorded the highest initial and final retention, and lateral dislodging recorded the lowest retention. For the telescopic attachment, posterior dislodgment recorded the highest initial and final retention, and anterior dislodging recorded the lowest retention. After repeated denture insertions and removals, the highest retention and stability were recorded with Locator medium followed by Locator light. The lowest retention was recorded with resilient telescopic attachment, and the lowest stability was recorded with Locator extra-light.

  3. The temperature effect of low-energy ion beam implantation on seed

    International Nuclear Information System (INIS)

    Chang Shenghe; Su Mingjie; Qin Guangyong; Wu Yuping; Zhao Haizhen

    2005-01-01

    The temperature effects of low-energy ion beam implantation on the seed germination were studied. Maize dry seeds were covered with copy paper, aluminum foil and without cover, respectively. Results showed that the germination rate of the seeds covered with paper which was the bad heat transmitter was the highest among three treatments, while that covered with aluminum foil which can transmit heat energy well was the least. The germination rate of the seeds covered with nothing was the second. Temperature affected seeds germination markedly. Generally the temperature of the target room inhibited the seeds' germination. After minus the effects of the temperature in the target room, the germination rates of the seeds were modified in this paper. The modified germination rate curve was also provided. (authors)

  4. 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

  5. SU-F-19A-11: Retrospective Evaluation of Thermal Coverage by Thermobrachytherapy Seed Arrangements of Clinical LDR Prostate Implants

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-15

    Purpose: The superiority of a properly-administered combination of radiation therapy and hyperthermia over radiation alone in treatment of human cancers has been demonstrated in multiple studies examining radiobiology, local control, and survival. Unfortunately, hyperthermia is not yet a common modality in oncology practice, due in part to the technical difficulty of heating a deep-seated target volume to sufficient temperature. To address this problem, our group has invented a thermobrachytherapy (TB) seed based on a commonly-used low dose-rate permanent brachytherapy seed for implant in solid tumors. Instead of the tungsten radiographic marker of the standard seed, the TB seed contains one of a self-regulating ferromagnetic alloy. Placement of a patient implanted with such seeds in an oscillating magnetic field generates heat via induction of eddy currents. We present the results of studies of the capability of clinically-realistic TB seed arrangements to adequately heat defined target volumes. Methods: Seed distributions for several past LDR prostate permanent implant brachytherapy patients were reproduced in the finite element analysis software package COMSOL Multiphysics 4.4, with the difference that TB seeds were modelled, rather than the radiation-only seeds actually used for their treatments. The implant geometries were mainly of the modified peripheral loading type; a range of prostatic volumes and blood perfusion rates likely to be seen in a clinical setting were examined. Results: According to the simulations, when distributed to optimize radiation dose, TB seeds also produce sufficient heat to provide thermal coverage of the target given proper selection of the magnetic field strength. However, the thermal distributions may be improved by additional use of hyperthermia-only seeds. Conclusion: A dual-modality seed intended as an alternative to and using the same implantation apparatus and technique as the standard LDR permanent implant seed has been

  6. Effect of Abutment Modification and Cement Type on Retention of Cement-Retained Implant Supported Crowns

    Science.gov (United States)

    Farzin, Mitra; Torabi, Kianoosh; Ahangari, Ahmad Hasan; Derafshi, Reza

    2014-01-01

    Objective: Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations. Materials and Method: Two prefabricated abutments were attached to their corresponding analogs and embedded in an acrylic resin block. The first abutment (control group) was left intact without any modifications. The screw access channel for the first abutment was completely filled with composite resin. In the second abutment, (test group) the axial wall was partially removed to form an abutment with 3 walls. Wax models were made by CAD/CAM. Ten cast copings were fabricated for each abutment. The prepared copings were cemented on the abutments by Temp Bond luting agent under standardized conditions (n=20). The assemblies were stored in 100% humidity for one day at 37°C prior to testing. The cast crown was removed from the abutment using an Instron machine, and the peak removal force was recorded. Coping/abutment specimens were cleaned after testing, and the testing procedure was repeated for Dycal luting agent (n=20). Data were analyzed with two- way ANOVA (α=0.05). Results: There was no significant difference in the mean transformed retention (Ln-R) between intact abutments (4.90±0.37) and the abutments with 3 walls (4.83±0.25) using Dycal luting agent. However, in TempBond group, the mean transformed retention (Ln-R) was significantly lower in the intact abutment (3.9±0.23) compared to the abutment with 3 walls (4.13±0.33, P=0.027). Conclusion: The retention of cement-retained implant restoration can be improved by the type of temporary cement used. The retention of cast crowns cemented to implant abutments with TempBond is influenced by the wall removal. PMID:25628660

  7. Effect of abutment modification and cement type on retention of cement-retained implant supported crowns.

    Directory of Open Access Journals (Sweden)

    Mitra Farzin

    2014-06-01

    Full Text Available Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations.Two prefabricated abutments were attached to their corresponding analogs and embedded in an acrylic resin block. The first abutment (control group was left intact without any modifications. The screw access channel for the first abutment was completely filled with composite resin. In the second abutment, (test group the axial wall was partially removed to form an abutment with 3 walls. Wax models were made by CAD/CAM. Ten cast copings were fabricated for each abutment. The prepared copings were cemented on the abutments by Temp Bond luting agent under standardized conditions (n=20. The assemblies were stored in 100% humidity for one day at 37°C prior to testing. The cast crown was removed from the abutment using an Instron machine, and the peak removal force was recorded. Coping/abutment specimens were cleaned after testing, and the testing procedure was repeated for Dycal luting agent (n=20. Data were analyzed with two- way ANOVA (α=0.05.There was no significant difference in the mean transformed retention (Ln-R between intact abutments (4.90±0.37 and the abutments with 3 walls (4.83±0.25 using Dycal luting agent. However, in TempBond group, the mean transformed retention (Ln-R was significantly lower in the intact abutment (3.9±0.23 compared to the abutment with 3 walls (4.13±0.33, P=0.027.The retention of cement-retained implant restoration can be improved by the type of temporary cement used. The retention of cast crowns cemented to implant abutments with TempBond is influenced by the wall removal.

  8. Study of deuterium retention in/release from ITER-relevant Be-containing mixed material layers implanted at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, K., E-mail: kazuyoshi.sugiyama@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Porosnicu, C. [National Institute for Laser, Plasma and Radiation Physics, EURATOM-MEdC Association, 077125 Bucharest (Romania); Jacob, W.; Roth, J.; Dürbeck, Th. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Jepu, I.; Lungu, C.P. [National Institute for Laser, Plasma and Radiation Physics, EURATOM-MEdC Association, 077125 Bucharest (Romania)

    2013-07-15

    D implantation into Be-containing mixed material layers: Be, Be–W (W: ∼6 at.%) and Be–C (C: ∼50 at.%), was performed at elevated temperatures. The temperature dependence of D retention varied depending on the admixed element. D retention in Be and Be–W layers decreases with increasing implantation temperature, while the Be–C layers maintained rather high D retention in the present investigated temperature range (up to 623 K). D desorption behaviour from Be–C suggests the contribution of C–D bonds to D retention. W admixture into Be can significantly suppress D retention in Be. Long-term isothermal annealing at 513 and 623 K for D removal was also performed to simulate the ITER-wall-baking scenario. Even extended annealing at temperatures comparable to or lower than the implantation temperature does not lead to a significant release of retained D.

  9. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    International Nuclear Information System (INIS)

    Xu Gang; Wang Xiaoteng; Gan Cailing; Fang Yanqiong; Zhang Meng

    2012-01-01

    Highlights: ► We analyzed biological effects of N + implantation on dry Jatropha curcas seed. ► N + implantation greatly decreased seedling survival rate. ► At doses beyond 15 × 10 16 ion cm −2 , biological repair took place. ► CAT was essential for H 2 O 2 removal. POD mainly functioned as seed was severely hurt. ► HAsA–GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N + with energy of 25 keV was applied to treat the dry seed at six different doses. N + beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 10 16 to 15 × 10 16 ions cm −2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 10 16 ion cm −2 , biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 10 16 ions cm −2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA–GSH cycle appeared to be for regeneration of HAsA.

  10. Dosimetric response of radioactive bio glass seeds implants on rabbit brain; Resposta radiodosimetrica de implantes de sementes de biovidros radioativos no cerebro de coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, I.T.; Campos, T.P.R., E-mail: itemponi@yahoo.com.br, E-mail: campos@nuclear.ufmg.br [Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares - Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)

    2007-07-01

    Interstitial implants of radioactive seeds are used as an efficient way of treating brain tumors. Bio glasses is an interesting alternative to the metallic implanted materials, because they can be absorbed by the organism, reducing the possibilities of side effects. The present paper investigates the dosimetry by the implants performed on rabbit's brain on the NRI/UFMG research group. The spatial distribution of the specific ionizing energy deposited per unit of mass generated by Sm-153 seeds were evaluated. A computational model of the brain's region was built using the software SISCODES produced by the research group. The sections of the computer tomography of a rabbit, which was included on the experiment, were digitalized. Those were converted in a three dimensional voxel model, including the tissues, its chemical composition and density. A simulation of the particles transport is performed by the stochastic code MCNP5. The implants consist of 15 ceramic Ca-Si-Sm seeds enriched with Sm-153, with 1.1.6 mm of length and 0.3 mm diameter, implanted on the rabbit's brain. It was predicted on the model three ribbons of 5 seeds each, spaced by 1.1.2 mm, since the ribbons were in a triangular topology whose vertices were spaced by 8 mm. The activities were 120 MBq/seed. The results show isodose regions superposed over the rabbits' model, reproducing the spatial energy deposition on the brain region. The absorbed dose predicted was 3.2 Gy per 15 seed; however it was not enough to tumor control. The authors suggest to increase the number of seeds and activity, reduction of the space to 5-6 mm among ribbons, improving dose with the beta emitting. (author)

  11. The surgical viability and radiological monitoring of brain implants of bioactive micro-seeds in an animal model

    Directory of Open Access Journals (Sweden)

    Giane X. O. Silva

    2005-10-01

    Full Text Available The interstitial implant is a therapeutic modality in brachytherapy of the head and neck. Presently, the seeds implanted in tumors in the central nervous system are metallic I-125. After the full emission of the radionuclide, the seed remains inert in the implanted area. Bioactive ceramic seeds have been prepared for this research group incorporating Sm-152 to be active in Sm-153. The main goal of the present study is the development of a the surgical technique for implanting the biodegradable radioactive micro-seeds in the brains of rabbits, as well as the observation of the clinical reactions of the animal after implantation of two sets of three seeds. The surgical procedure consisted of performing two separate perforations 10 mm from each other in the skull, permitting the implantation of two groups of three seeds, totaling six seeds. The results of the pilot study showed the effectiveness of the surgical procedure and of the biocompatibility of the seeds and the lack of presence of adverse reactions, functional sequels, or inflammation in a follow up 50 days post-surgery. Such seeds of reduced volume, 0.2 x 1.6 mm, could be monitored by computerized tomography 30 days after implanting.Os implantes intersticiais podem ser utilizados em braquiterapia de cabeça e pescoço. Atualmente as sementes implantadas no CNS são de I-125 metálicas. Após o decaimento do radioisótopo, a semente fica inerte na região implantada. Sementes cerâmicas bioativas tem sido preparadas pelo grupo de pesquisa incorporando Sm-152. O presente estudo tem o objetivo de viabilizar a técnica cirúrgica de implantes de microsementes biodegradáveis não radioativas no cérebro de coelhos, bem como verificar as reações clínicas e funcionais do animal ao corpo estranho implantado. O procedimento cirúrgico compreendeu em proceder duas perfurações separadas em 10mm na calota craniana onde foi possível a implantação de dois conjuntos de três sementes

  12. Effect of noble gas ion pre-irradiation on deuterium retention in tungsten

    NARCIS (Netherlands)

    Cheng, L.; Zhao, Z. H.; De Temmerman, G.; Yuan, Y.; Morgan, T. W.; Guo, L. P.; Wang, B.; Zhang, Y.; Wang, B. Y.; Zhang, P.; Cao, X. Z.; Lu, G. H.

    2016-01-01

    Impurity seeding of noble gases is an effective way of decreasing the heat loads onto the divertor targets in fusion devices. To investigate the effect of noble gases on deuterium retention, tungsten targets have been implanted by different noble gas ions and subsequently exposed to deuterium

  13. 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)

  14. 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)

  15. Suggestions on technical guide of implantation of radioactive seeds

    International Nuclear Information System (INIS)

    Wang Zhongmin; Huang Gang; Lv Zhongwei; Liu Jianjun; Chen Kemin; Chen Yongde

    2009-01-01

    Implantation of radioactive seeds is an effective therapeutic option for the treatment of malignant tumors. With the development of imaging technique and the use of treatment planning system (TPS) it has been more and more employed in clinical settings. The technique has been widely practiced in various malignant tumors, such as prostate cancer, lung caner, pancreatic cancer, hepatocarcinoma, etc. In order to standardize the clinical application of this technology, the authors propose some suggestions concerning the management of radioactive seeds, the indications and contraindications as well as the method of operation as a technical guidance. (authors)

  16. Suggestions on technical guide of implantation of radioactive seeds

    Energy Technology Data Exchange (ETDEWEB)

    Zhongmin, Wang; Gang, Huang; Zhongwei, Lv; Jianjun, Liu [Department of Radiology, Luwan Branch of Ruijin Hospital, School of Medicine, Shanghai Jiaotong Univ., Shanghai (China); Kemin, Chen; Yongde, Chen

    2009-09-15

    Implantation of radioactive seeds is an effective therapeutic option for the treatment of malignant tumors. With the development of imaging technique and the use of treatment planning system (TPS) it has been more and more employed in clinical settings. The technique has been widely practiced in various malignant tumors, such as prostate cancer, lung caner, pancreatic cancer, hepatocarcinoma, etc. In order to standardize the clinical application of this technology, the authors propose some suggestions concerning the management of radioactive seeds, the indications and contraindications as well as the method of operation as a technical guidance. (authors)

  17. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Xu Gang, E-mail: xg335300@yahoo.com.cn [Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025 (China); Institute of Entomology, Guizhou University, Guiyang 550025 (China); Wang Xiaoteng [Department of Agricultural Resources and Environment, College of Agricultural, Guizhou University, Guiyang 550025 (China); Gan Cailing; Fang Yanqiong; Zhang Meng [College of Life Sciences, Guizhou University, Guiyang 550025 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyzed biological effects of N{sup +} implantation on dry Jatropha curcas seed. Black-Right-Pointing-Pointer N{sup +} implantation greatly decreased seedling survival rate. Black-Right-Pointing-Pointer At doses beyond 15 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place. Black-Right-Pointing-Pointer CAT was essential for H{sub 2}O{sub 2} removal. POD mainly functioned as seed was severely hurt. Black-Right-Pointing-Pointer HAsA-GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N{sup +} with energy of 25 keV was applied to treat the dry seed at six different doses. N{sup +} beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 Multiplication-Sign 10{sup 16} to 15 Multiplication-Sign 10{sup 16} ions cm{sup -2} severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 Multiplication-Sign 10{sup 16} ions cm{sup -2} may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  18. 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)

  19. Biological effects of ion implantation on processing tomato and eggplant seed

    International Nuclear Information System (INIS)

    Mao Peihong; Zeng Xianxian; Jin Xiang

    2004-01-01

    The seed of processing tomato '87-5' (Lycopersicon esculentum Mill) were implanted by the low energy nitrogen ion (N + ) with 6 different doses. The rate of emergence was little reduced in M1 generation, but the fruiting number per plant was increased and it's maturing earlier 20 days than the control. The precocity, disease resistance and stronger growth vigor were shown in M2 generation. Experimental results of two years showed that, according to synthetic analysis in factors such as precocity, disease resistance, high yield and quality, the N + dose of 6 x 10 16 cm -2 (60 times of pulse) for tomato seed '87-5' had been proved to have notable biological effects on M1 and M2 generation. The seed of eggplant 'Wuyeqie' (Solanum melongena L.) was also implanted by the low energy nitrogen ion (N + ) with 2 different doses. Multi-vertical channel fruits were obtained in variable M1 generation, which liked the pomelo without peel. The seed of these variable eggplants was taken and planted in the next year. The meaningful variable fruits, the characters of disease-resistance, purple-peel, small-navel, lantern-form, large-scale, etc. were obtained in beneficial M2 generation. The biggest single-fruit weight reached 1.53 kg, providing valuable germplasm resource for breeding. (authors)

  20. Radiobiologically based treatment plan evaluation for prostate seed implants

    Directory of Open Access Journals (Sweden)

    Sotirios Stathakis

    2011-07-01

    Full Text Available Purpose: Accurate prostate low dose-rate brachytherapy treatment plan evaluation is important for future care decisions. Presently, an evaluation is based on dosimetric quantifiers for the tumor and organs at risk. However, these do not account for effects of varying dose-rate, tumor repopulation and other biological effects. In this work, incorporation of the biological response is used to obtain more clinically relevant treatment plan evaluation.Material and methods: Eleven patients were evaluated. Each patient received a 145 Gy implant. Iodine-125 seeds were used and the treatment plans were created on the Prowess system. Based on CT images the post-implant plan was created. In the post-plan, the tumor, urethra, bladder and rectum were contoured. The biologically effective dose was used to determine the tumor control probability and the normal tissue complication probabilities for the urethra, bladder, rectum and surrounding tissue. Results: The average tumor control probability and complication probabilities for the urethra, bladder, rectum and surrounding tissue were 99%, 29%, 0%, 12% and 6%, respectively. These measures provide a simpler means for evaluation and since they include radiobiological factors, they provide more reliable estimation of the treatment outcome. Conclusions: The goal of this work was to create more clinically relevant prostate seed-implant evaluation by incorporating radiobiological measures. This resulted in a simpler descriptor of treatment plan quality and was consistent with patient outcomes.

  1. Dosimetry verification of radioactive seed implantation for malignant tumors assisted by 3D printing individual templates and CT guidance

    International Nuclear Information System (INIS)

    Ji, Zhe; Jiang, Yuliang; Guo, Fuxin; Sun, Haitao; Fan, Jinghong; Zhang, Lujing; Wang, Junjie

    2017-01-01

    Objective: We compared the dose distributions of postoperative plans with preoperative plans for 3D printing template-assisted radioactive seed implantations. Methods: A total of 14 patients with malignant tumors enrolled in the study. The dose parameters included D90, minimum peripheral dose, V100, V150, and V200. The statistical method was the paired t-test. Results: There was no significant difference in P values between the two groups for all parameters except for V100. Conclusions: The 3D printing guide template can provide good accuracy for radioactive seed implantation. - Highlights: • It is the first study we as for as we know to compare the preoperative and postoperative dosimetry results of 3D printing templates-assisted radioactive seeds implantation for malignant tumor. • 3D printing guide template can provide good accuracy for radioactive seeds implantation. • The actual dose distributions in postoperative validations were closed to the expectations of preoperative plans. • 3D printing template providing us an effective tool for the standardization and normalization of seed implantation, and having a good application prospect and worthy of further development and popularization.

  2. 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)

  3. Seeding of silicon by copper ion implantation for selective electroless copper plating

    Energy Technology Data Exchange (ETDEWEB)

    Bhansali, S.; Sood, D.K.; Zmood, R.B. [Microelectronic and Materials Technology Centre, Royal Melbourne Institute of Technolgy, Melbourne, VIC (Australia)

    1993-12-31

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm{sup 2} using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm{sup 2} for `seed` formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by `scotch tape test`. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs.

  4. Seeding of silicon by copper ion implantation for selective electroless copper plating

    Energy Technology Data Exchange (ETDEWEB)

    Bhansali, S; Sood, D K; Zmood, R B [Microelectronic and Materials Technology Centre, Royal Melbourne Institute of Technolgy, Melbourne, VIC (Australia)

    1994-12-31

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm{sup 2} using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm{sup 2} for `seed` formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by `scotch tape test`. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs.

  5. Seeding of silicon by copper ion implantation for selective electroless copper plating

    International Nuclear Information System (INIS)

    Bhansali, S.; Sood, D.K.; Zmood, R.B.

    1993-01-01

    We report on the successful use of copper(self) ion implantation into silicon to seed the electroless plating of copper on silicon (100) surfaces. Copper ions have been implanted to doses of 5E14-6.4E16 ions/cm 2 using a MEEVA ion implanter at extraction voltage of 40kV. Dose was varied in fine steps to determine the threshold dose of 2E15 Cu ions/cm 2 for 'seed' formation of copper films on silicon using a commercial electroless plating solution. Plated films were studied with Rutherford backscattering spectrometry, scanning electron microscopy, EDX and profilometry . The adhesion of films was measured by 'scotch tape test'. The adhesion was found to improve with increasing dose. However thicker films exhibited rather poor adhesion and high internal stress. SEM results show that the films grow first as isolated islands which become larger and eventually impinge into a continuous film as the plating time is increased. (authors). 5 refs., 1 tab., 3 figs

  6. RICE SEED TREATMENT AND RECOATING WITH POLYMERS: PHYSIOLOGICAL QUALITY AND RETENTION OF CHEMICAL PRODUCTS

    Directory of Open Access Journals (Sweden)

    LOVANE KLEIN FAGUNDES

    2017-01-01

    Full Text Available The use of chemical seed treatment is an important tool in the protection of seedlings and has contributed to the increase of rice yield (Oryza sativa L.. The objective of this study was to evaluate the physiological quality and quantify the retention of chemical products in rice seeds treated with insecticide and fungicide coated with polymers. Six seed treatments were used: control, phytosanitary treatment and phytosanitary treatment and coating with the polymers, Florite 1127®, GV5® Solid Resin, Polyseed CF® and VermDynaseed®. The physiological quality was evaluated by the test of germination and vigor by first count tests, germination speed index, shoot length, radicle length, seedling dry mass and sand emergence. To determine the retention of the active ingredients metalaxyl-M and thiamethoxam, an equipment called extractor was used. The experiment was organized in a completely randomized design (DIC and the averages were separated by the Scott Knott test (p≤0.05. Seed treatment with the fungicide and insecticide, coated with the polymers, Florite 1127®, Solid Resin GV5®, Polyseed CF® and VermDynaseed®, did not affect the physiological quality of rice seeds. Solid Resin GV5®, Polyseed CF® and VermDynaseed® polymers were efficient at retaining thiamethoxam in the rice seeds, preventing some of the active ingredients of the insecticide from being leached through the sand columns immediately after the simulated pluvial precipitation.

  7. Influence of cement film thickness on the retention of implant-retained crowns.

    Science.gov (United States)

    Mehl, Christian; Harder, Sönke; Steiner, Martin; Vollrath, Oliver; Kern, Matthias

    2013-12-01

    The main goal of this study was to establish a new, high precision procedure to evaluate the influence of cement film thickness on the retention of cemented implant-retained crowns. Ninety-six tapered titanium abutments (6° taper, 4.3 mm diameter, Camlog) were shortened to 4 mm. Computer-aided design was used to design the crowns, and selective laser sintering, using a cobalt-chromium alloy, was used to produce the crowns. This method used a focused high-energy laser beam to fuse a localized region of metal powder to build up the crowns gradually. Before cementing, preset cement film thicknesses of 15, 50, 80, or 110 μm were established. Glass ionomer, polycarboxylate, or resin cements were used for cementation. After 3 days storage in demineralized water, the retention of the crowns was measured in tension using a universal testing machine. The cement film thicknesses could be achieved with a high level of precision. Interactions between the factors cement and cement film thickness could be found (p ≤ 0.001). For all cements, crown retention decreased significantly between a cement film thickness of 15 and 50 μm (p ≤ 0.001). At 15 μm cement film thickness, the resin cement was the most retentive cement, followed by the polycarboxylate and then the glass ionomer cement (p ≤ 0.05). The results suggest that cement film thickness has an influence on the retentive strength of cemented implant-retained crowns. © 2013 by the American College of Prosthodontists.

  8. 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

  9. 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

  10. Do dual-thread orthodontic mini-implants improve bone/tissue mechanical retention?

    Science.gov (United States)

    Lin, Yang-Sung; Chang, Yau-Zen; Yu, Jian-Hong; Lin, Chun-Li

    2014-12-01

    The aim of this study was to understand whether the pitch relationship between micro and macro thread designs with a parametrical relationship in a dual-thread mini-implant can improve primary stability. Three types of mini-implants consisting of single-thread (ST) (0.75 mm pitch in whole length), dual-thread A (DTA) with double-start 0.375 mm pitch, and dual-thread B (DTB) with single-start 0.2 mm pitch in upper 2-mm micro thread region for performing insertion and pull-out testing. Histomorphometric analysis was performed in these specimens in evaluating peri-implant bone defects using a non-contact vision measuring system. The maximum inserted torque (Tmax) in type DTA was found to be the smallest significantly, but corresponding values found no significant difference between ST and DTB. The largest pull-out strength (Fmax) in the DTA mini-implant was found significantly greater than that for the ST mini-implant regardless of implant insertion orientation. Mini-implant engaged the cortical bone well as observed in ST and DTA types. Dual-thread mini-implant with correct micro thread pitch (parametrical relationship with macro thread pitch) in the cortical bone region can improve primary stability and enhanced mechanical retention.

  11. Implanted He retention and release from boronized layers

    International Nuclear Information System (INIS)

    Doyle, B.L.; Walsh, D.S.; Wampler, W.R.

    1992-01-01

    3 He has been implanted at an energy of 3 keV into amorphous hydrogenated boron-carbon (a-BC) films deposited by rf sputtering onto single crystal Si substrates. The initial composition of the films was analyzed by nuclear-enhanced backscattering spectrometry to be B 2 C with ∝20% H and ∝10% O. The areal density of the implanted and retained 3 He was measured in situ by a new ion beam analysis technique using the 3 He( 3 He, pp) three-body nuclear reaction. The He trapping or pumping efficiency at room temperature is only 3.4% for low fluence implants and the a-BC layer saturates with He at a fluence of 5x10 17 He/cm 2 . At this saturation fluence, only 3.1x10 15 He/cm 2 is retained in the film. Isochronal annealing of the implanted samples reveals a distributed release of implanted He at ∝200deg C, which corresponds to a trap activation energy of 1.65±0.25 eV. 3 He was trapped less efficiently at 250deg C than at room temperature and exhibited a saturated retention of 8.6x10 14 He/cm 2 . These results indicate that wall pumping should play only a minor role in the interpretation of the Textor He-pump experiment carried out earlier this year. The results also show that the unintentional deposition of a-Bc, onto He pumping plates could adversely affect the operation of such devices, and should therefore be avoided. (orig.)

  12. Retention Strength after Compressive Cyclic Loading of Five Luting Agents Used in Implant-Supported Prostheses

    Directory of Open Access Journals (Sweden)

    Angel Alvarez-Arenal

    2016-01-01

    Full Text Available The purpose of this study was to evaluate and compare the retention strength of five cement types commonly used in implant-retained fixed partial dentures, before and after compressive cyclic loading. In five solid abutments screwed to 5 implant analogs, 50 metal Cr-Ni alloy copings were cemented with five luting agents: resin-modified glass ionomer (RmGI, resin composite (RC, glass ionomer (GI, resin urethane-based (RUB, and compomer cement (CC. Two tensile tests were conducted with a universal testing machine, one after the first luting of the copings and the other after 100,000 cycles of 100 N loading at 0.72 Hz. The one way ANOVA test was applied for the statistical analysis using the post hoc Tukey test when required. Before and after applying the compressive load, RmGI and RC cement types showed the greatest retention strength. After compressive loading, RUB cement showed the highest percentage loss of retention (64.45%. GI cement recorded the lowest retention strength (50.35 N and the resin composite cement recorded the highest (352.02 N. The type of cement influences the retention loss. The clinician should give preference to lower retention strength cement (RUB, CC, and GI if he envisages any complications and a high retention strength one (RmGI, RC for a specific clinical situation.

  13. 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

  14. 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

  15. 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.

  16. 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

    Purpose/Objective: Image-based dose evaluation of permanent brachytherapy implants for prostate cancer is important for optimal patient management after implantation. Because of edema caused by the surgical procedure in the implantation, if the dose evaluation is based on the images obtained too early after implantation, dose coverage will usually be underestimated. Conversely, if the images are obtained too late, the dose coverage will be overestimated. This study uses a biomathematical model to simulate edema and its resolution on 29 patients, so that the optimum time to obtain image scans and perform dose evaluation can be investigated and estimated. Methods and Materials: Edema of a prostate and its resolution has been shown to follow an exponential function V(t) = V(0)(1 + ΔV[e -0.693t/Te - 1]) where ΔV is the initial relative increase in the prostate volume due to edema (and is related to edema magnitude), and T e (edema half-life) is the time for the edema to decrease by half in volume. In this study, edema was simulated by increasing the volume of preimplant prostate (obtained from ultrasound volume study) to a given magnitude of edema. Similarly, the locations of planned seeds were changed to their corresponding locations in the edematous prostate proportionally. The edema was then allowed to resolve according to the exponential function. The correct dose distribution was calculated by taking into account the dynamic variations of the prostate volume, seed locations, and source strengths with respect to time. Dose volume histograms (DVHs) were then generated from this dose distribution. The conventional postimplant DVHs, which assume the prostate volume and seed locations are as in the image scans and constant in time, were also calculated based on the simulated image scans for various days postimplantation. The conventional DVHs of prostate on various days after implantation were compared to the DVH calculated assuming dynamic conditions. The optimum

  17. Influence of Be seeding on microstructures of tungsten exposed to D–He mixture plasmas in PISCES and its impacts on retention properties

    International Nuclear Information System (INIS)

    Miyamoto, Mitsutaka; Nishijima, Daisuke; Baldwin, Matthew; Doerner, Russ; Ueda, Yoshio; Sagara, Akio

    2013-01-01

    Microstructural changes and their impacts on D retention properties in tungsten (W) are investigated due to mixed species D–Be–He plasma exposure. Be seeding to D + He mixture plasmas results in the suppression of high density He nano-bubbles, which are distinctive internal defects observed in He irradiated/exposed metals. In contrast, cavities appear in the near surface of W exposed to D + Be plasmas, when a thick Be deposition layer forms. Since bubbles are not generally observed in W exposed to D plasma, the cavities seem to be deuterium bubbles formed in the deposited Be layer. While D retention significantly decreases in W exposed to D + He plasma without Be, Be seeding to D + He mixture plasmas obstructs this He seeding effect. As a consequence, it is considered that Be seeding has a more dominant influence on microstructures and D retention in plasma-exposed W than He seeding

  18. Prostate brachytherapy postimplant dosimetry: Seed orientation and the impact of dosimetric anisotropy in stranded implants

    International Nuclear Information System (INIS)

    Chng, Nicholas; Spadinger, Ingrid; Rasoda, Rosey; Morris, W. James; Salcudean, Septimiu

    2012-01-01

    Purpose: In postimplant dosimetry for prostate brachytherapy, dose is commonly calculated using the TG-43 1D formalism, because seed orientations are difficult to determine from CT images, the current standard for the procedure. However, the orientation of stranded seeds soon after implantation is predictable, as these seeds tend to maintain their relative spacing, and orient themselves along the implant trajectory. The aim of this study was to develop a method for determining seed orientations from reconstructed strand trajectories, and to use this information to investigate the dosimetric impact of applying the TG-43 2D formalism to clinical postimplant analysis. Methods: Using in-house software, the preplan to postimplant seed correspondence was determined for a cohort of 30 patients during routine day-0 CT-based postimplant dosimetry. All patients were implanted with stranded-seed trains. Spline curves were fit to each set of seeds composing a strand, with the requirement that the distance along the spline between seeds be equal to the seed spacing within the strand. The orientations of the seeds were estimated by the tangents to the spline at each seed centroid. Dose distributions were then determined using the 1D and 2D TG-43 formalisms. These were compared using the TG-137 recommended dose metrics for the prostate, prostatic urethra, and rectum. Results: Seven hundred and sixty one strands were analyzed in total. Defining the z-axis to be cranial-positive and the x-axis to be left-lateral positive in the CT coordinate system, the average seed had an inclination of 21 deg. ± 10 deg. and an azimuth of -81 deg. ± 57 deg. These values correspond to the average strand rising anteriorly from apex to base, approximately parallel to the midsagittal plane. Clinically minor but statistically significant differences in dose metrics were noted. Compared to the 2D calculation, the 1D calculation underestimated prostate V100 by 1.1% and D90 by 2.3 Gy, while

  19. 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

  20. Fuel retention in impurity seeded discharges in JET after Be evaporation

    International Nuclear Information System (INIS)

    Brezinsek, S.; Esser, H.G.; Huber, A.; Kruezi, U.; Philipps, V.; Sergienko, G.; Loarer, T.; Krieger, K.; Eich, T.; McCormick, K.; Jachmich, S.; Tsalas, M.; Coffey, I.; Fundamenski, W.; Giroud, C.; Gruenhagen, S.; Knipe, S.; Maddison, G.P.; Meigs, A.G.; Morgan, Ph.

    2011-01-01

    Preparatory experiments for the ITER-Like Wall in JET were carried out to simulate the massive Be first wall by a thin Be layer, induced by evaporation of about 2.0 g Be, and to study its impact on fuel retention and divertor radiation with reduced C content and N seeding. Residual gas analysis reveals a reduction of hydrocarbons by one order of magnitude and of O by a factor of 5 in the partial pressure owing to the evaporation. The evolution of wall conditions, impurity fluxes and divertor radiation have been studied in ELMy H-mode plasmas (B t = 2.7 T, I p = 2.5 MA, P aux = 16 MW) whereas a non-seeded reference discharge was executed prior to the evaporation. The in situ measured Be flux at the midplane increased by about a factor of 40 whereas the C flux decreased by ∼50% in the limiter phase of the first discharge with respect to the reference, but erosion of the Be layer and partial coverage with C takes place quickly. To make best use of the protective Be layer, only the first four discharges were employed for a gas balance analysis providing a D retention rate of 1.94 x 10 21 D s -1 which is comparable to rates with C walls. But the Be evaporation provides a non-saturated surface with respect to D and short term retention is not negligible in the balance; the measured retention is overestimated with respect to steady-state conditions like that of the ILW. Moreover, C was only moderately reduced and co-deposition of fuel with eroded Be and C occurs. The lower C content leads to a minor reduction in divertor radiation as the reference phase prior to seeding indicates. N adds to the radiation of D and the remaining C, and the N content rises due to the legacy effect which has been quantified by gas balance to be 30% of the injected N. C radiation increases with exposure time, and both contributors cause an increase in the radiated fraction in the divertor from 50% to 70%. The radiation pattern suggests that N dominates the increase in the first discharges

  1. 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)

  2. Retention of seed trees fails to lifeboat ectomycorrhizal fungal diversity in harvested Scots pine forests.

    Science.gov (United States)

    Varenius, Kerstin; Lindahl, Björn D; Dahlberg, Anders

    2017-09-01

    Fennoscandian forestry has in the past decades changed from natural regeneration of forests towards replantation of clear-cuts, which negatively impacts ectomycorrhizal fungal (EMF) diversity. Retention of trees during harvesting enables EMF survival, and we therefore expected EMF communities to be more similar to those in old natural stands after forest regeneration using seed trees compared to full clear-cutting and replanting. We sequenced fungal internal transcribed spacer 2 (ITS2) amplicons to assess EMF communities in 10- to 60-year-old Scots pine stands regenerated either using seed trees or through replanting of clear-cuts with old natural stands as reference. We also investigated local EMF communities around retained old trees. We found that retention of seed trees failed to mitigate the impact of harvesting on EMF community composition and diversity. With increasing stand age, EMF communities became increasingly similar to those in old natural stands and permanently retained trees maintained EMF locally. From our observations, we conclude that EMF communities, at least common species, post-harvest are more influenced by environmental filtering, resulting from environmental changes induced by harvest, than by the continuity of trees. These results suggest that retention of intact forest patches is a more efficient way to conserve EMF diversity than retaining dispersed single trees. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Aspects of an automatic system of implants of radioactive seeds and anatomic object simulator for tests in prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Leonardo S.M.; Braga, Viviane V.B.; Campos, Tarcísio P. R. de, E-mail: leonardosantiago.lsms@gmail.com, E-mail: vitoriabraga06@gmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (PCTN/UFMG), Belo Horizonte (Brazil). Pós-Graduação em Ciências e Técnicas Nucleares. Departamento de Engenharia Nuclear

    2017-07-01

    This work presents the state of the art of the research and development of an automatic radioactive seed implantation system (PSIS). PSIS may assist in the procedure of testing permanent implants in the prostate. These tests will be important in measurements of absorbed doses in the pelvic structures, involving the organs and tissues at risk to improve planning, seed positioning and dosimetry. The automated Prostate Seed Implant System (PSIS) has been designed to meet operational needs, which offers the freedom of positioning of the brachytherapy needle within the treatment area and ensures repeatability and fidelity to the planned treatment. Both the ultrasound probe and the seed implant needle are driven by step motors, Atmega microcontroller, bearings, aluminum shafts and a GUI (Graphical User Interface). Movement of both the probe and the needle holder was performed by fixed spindle on a threaded rod rushing to the step motors by a coupling. The step motors used to move the system consist of step motors used in CNC (Computer Numeric Control) machine. The choice of these engines occurred due to the precision in the movements that can be obtained with these types of motors. The ultrasound probe serves to help, through the images acquired during the longitudinal movement, to monitor the application of the seeds. The parts that make up the system infrastructure were made of aluminum and translucent acrylic and cylindrical aluminum bars of different diameters. All these pieces were fixed and adjusted trough screws, washers, nuts and adhesive to metal, composing the final prototype of the PSIS. The project was developed and the PSIS prototype was assembled. The prototype presented acceptable operating characteristics for prostate implants. The advantage of this system is the automation of the application that provides an accurate positioning and movement of both probe and seed application. In addition to this study, seeds implantation tests will be performed, and

  4. Aspects of an automatic system of implants of radioactive seeds and anatomic object simulator for tests in prostate brachytherapy

    International Nuclear Information System (INIS)

    Silva, Leonardo S.M.; Braga, Viviane V.B.; Campos, Tarcísio P. R. de

    2017-01-01

    This work presents the state of the art of the research and development of an automatic radioactive seed implantation system (PSIS). PSIS may assist in the procedure of testing permanent implants in the prostate. These tests will be important in measurements of absorbed doses in the pelvic structures, involving the organs and tissues at risk to improve planning, seed positioning and dosimetry. The automated Prostate Seed Implant System (PSIS) has been designed to meet operational needs, which offers the freedom of positioning of the brachytherapy needle within the treatment area and ensures repeatability and fidelity to the planned treatment. Both the ultrasound probe and the seed implant needle are driven by step motors, Atmega microcontroller, bearings, aluminum shafts and a GUI (Graphical User Interface). Movement of both the probe and the needle holder was performed by fixed spindle on a threaded rod rushing to the step motors by a coupling. The step motors used to move the system consist of step motors used in CNC (Computer Numeric Control) machine. The choice of these engines occurred due to the precision in the movements that can be obtained with these types of motors. The ultrasound probe serves to help, through the images acquired during the longitudinal movement, to monitor the application of the seeds. The parts that make up the system infrastructure were made of aluminum and translucent acrylic and cylindrical aluminum bars of different diameters. All these pieces were fixed and adjusted trough screws, washers, nuts and adhesive to metal, composing the final prototype of the PSIS. The project was developed and the PSIS prototype was assembled. The prototype presented acceptable operating characteristics for prostate implants. The advantage of this system is the automation of the application that provides an accurate positioning and movement of both probe and seed application. In addition to this study, seeds implantation tests will be performed, and

  5. 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

  6. Distribution of implanted ions in seeds and roots of mung bean

    International Nuclear Information System (INIS)

    Liu Donghua; Wang Wei; Jiang Wusheng; Zhang Zhixiang; Hou Wenqiang; Guo Ximing; Li Yi

    1998-01-01

    Doses of 1 x 10 16 , and 2 x 10 16 cm -2 and 1 x 10 16 , 2 x 10 16 , 3 x 10 16 and 3.6 x 10 16 cm -2 for iron and copper ions are implanted in dry seeds of mung bean, respectively. The results show that the accumulated-copper and -iron ion amounts in the seeds and roots vary with different doses of ion beam, and the fresh and dry weights of the roots decrease progressively with increasing iron and copper doses, except the treatment of 1 x 10 16 Cu + ions/cm 2 , and the accumulated-copper and -iron ion amounts in the seeds of the different test groups can be correlated with the ion distribution in the roots

  7. Retention of implant-supported zirconium oxide ceramic restorations using different luting agents.

    Science.gov (United States)

    Nejatidanesh, Farahnaz; Savabi, Omid; Shahtoosi, Mojtaba

    2013-08-01

    The aim of this study was to evaluate the retention value of implant-supported zirconium oxide ceramic copings using different luting agents. Twenty ITI solid abutments of 5.5 mm height and ITI implant analogs were mounted vertically into autopolymerizing acrylic resin blocks. Ninety zirconium oxide copings (Cercon, Degudent) with a loop on the occlusal portion were made. All samples were airborne particle abraded with 110 μm Al₂O₃ and luted using different types of luting agents: resin cements (Clearfil SA, Panavia F2.0, Fuji Plus), conventional cements (Fleck's, Poly F, Fuji I), and temporary cements (Temp Bond, GC free eugenol, TempSpan) with a load of 5 Kg. (N = 10) All copings were incubated at 37°C for 24 h and conditioned in artificial saliva for 1 week, and thermal cycled for 5000 cycles 5-55°C with a 30-s dwell time. The dislodging force of the copings along the long axis of the implant-abutment complex was recorded using universal testing machine with 5 mm/min crosshead speed. Data were subjected to Kruskal-Wallis (α = 0.05) and Mann-Whitney tests with Bonferroni step down correction (α = 0.001). There was significant difference between the mean rank retention values of different luting agents (P zirconium oxide restorations. © 2011 John Wiley & Sons A/S.

  8. Factors influencing retention of visible implant tags by westslope cutthroat trout inhabiting headwater streams of Montana

    Science.gov (United States)

    Bradley B. Shepard; Jim Robison-Cox; Susan C. Ireland; Robert G. White

    1996-01-01

    Retention of visible implant (VI) tags by westslope cutthroat trout Oncorhynchus clarki lewisi inhabiting 20 reaches of 13 isolated headwater tributary drainages in Montana was evaluated during 1993 and 1994. In 1993, 2,071 VI tags were implanted in westslope cutthroat trout (100-324 mm fork length) and adipose tins were removed as a secondary mark to evaluate tag...

  9. 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.

  10. Retention system for implant-supported dentures used by brazilian dentists who work in implant dentistry

    Directory of Open Access Journals (Sweden)

    Saturnino Aparecido Ramalho

    2010-04-01

    Full Text Available Objective: To provide the dentists with support in the choice of the cement or screw type of retention for implant-supported dentures, according to the patient’s problem. Methods: An opinion questionnaire was applied to a sample of 468 participants, all dentists working in the field of Implant Dentistry, of whom 272 (58.1% participated in the 4th International Congress of Osseointegration of APCD, held in São Paulo (SP from 6 to 9 May 2004, 119 (25.4% participated in the 2nd International Congress of Implant Dentistry of Minas Gerais, between 10 and 12 June 2004 and 77 (16.5% were professors and specialization and master students from São Leopoldo Mandic. Results: The results showed that 254 participants opted for the screw-retained system while 214 opted for the cement-retained system. Conclusion: There was a preference for the use of the screw-retained system, and that both cemented and screw-retained systems have advantages and disadvantages, so that the dentist is left to decide and evaluate them in order to indicate and use them with confidence in different clinical cases.

  11. Implanted Deuterium Retention and Release in Carbon-Coated Beryllium

    Science.gov (United States)

    Anderl, R. A.; Longhurst, G. R.; Pawelko, R. J.; Oates, M. A.

    1997-06-01

    Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 Å. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 Å revealed that exposure to a temperature of 400°C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400°C and an incident deuterium flux of approximately 6 × 1019 D/m2-s), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples.

  12. Dosimetry consequences of the accuracy at the position of the seeds in a seeds implant of I-125 in prostate; Consecuencias dosimetricas de la exactitud en la posicion de las semilla en un implante de semillas de I-125 en prostata

    Energy Technology Data Exchange (ETDEWEB)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-07-01

    The quality control of equipment used to carry out implants of seeds of low rate in prostate, van destined to watch, the activity of seeds and the calculation of planning both positioning them on the inside of the patient. The objective of this work is, using the Nucletron Spot Pro and SeedSelectron, rating dosimetry possible consequences related to the position of the seeds. (Author)

  13. 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

  14. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Science.gov (United States)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  15. 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)

  16. SU-F-T-653: Radiation Exposure from Cs-131 Permanent Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Giaddui, T; Hardin, M; To, D; Kremmel, E; Peng, C; Hann, P; Richardson, S; Yu, Y; Harrison, A; Doyle, L [Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States)

    2016-06-15

    Purpose: Permanent seed implants have traditionally been used to treat prostate, lung and head or neck cancers using I-125 and Pd-103. Cs-131, which has higher dose rate is being used to treat brain, head and/or neck cancers in our clinic, therefore, we chose to monitor the dose received by surgeons during the extensive procedure. The aims of this work are to assess the level of radiation exposure to surgeons and the instantaneous exposure at bedside and 1 m from patients. Methods: Ten patients received Cs-131 implants for recurrent brain,head and/or neck cancer; the median implanted activity, number of implanted seeds and prescription dose at 0.5 cm from the perpendicular plane of the implant were: 54.3 mCi (14.52 – 77); 19 (4 – 24) and 60 Gy (range 42 – 60) respectively. Radiation exposure was recorded at bedside and 1 m from the patient using Victoreen ion chamber (Fluke Biomedical, Cleveland, OH). Exposure to surgeons was measured using TLD (Mirion Technologies (GDS), Inc., USA). Results: The median equivalent dose rate at 1 m and bedside immediately following implantation were 1.49×10-2 mSv/h (8.77×10-3–2.63×10-2) and 7.76×10-2 mSv/h (3.1×10-2– 1.53×10-1) respectively. Median equivalent dose to surgeons’ hands was 0.60 mSv (0.33 – 1.48) and no doses were detected for whole-body. Surgical reconstruction for one patient was performed 71 days post-implant and resulted in zero exposure to surgeons. Conclusion: The recorded exposure rates were low when compared with the literature. Post procedure surveys at bed site and 1 m indicated that all patients were within safe limits for discharge (< 0.05 mSv/h at 1 m). However, as a precautionary measure, patients were advised to avoid direct contact with children and pregnant women within four weeks of the implant and stay at least at 3 ft from other people. Surgeons doses were well within occupational dose limits.

  17. Atomic retention and near infrared photoluminescence from PbSe nanocrystals fabricated by sequential ion implantation and electron beam annealing

    International Nuclear Information System (INIS)

    Carder, D.A.; Markwitz, A.; Reeves, R.J.; Kennedy, J.; Fang, F.

    2013-01-01

    Nanocrystals of PbSe have been fabricated in a silicon dioxide matrix by sequential low energy ion implantation followed by an electron beam annealing step. Transmission electron microscopy reveals PbSe nanocrystals with typical sizes between 3 and 10 nm in the sub-surface region. Rutherford Backscattering Spectrometry has been used to study the total atomic retention, as a function of implanted atoms, following annealing. Photoluminescence was observed in various samples, at 4 K, as a broad peak between 1.4 and 2.0 μm, with observation of a dependence of the peak wavelength on annealing temperature. Room temperature photoluminescence was observed for samples with a high retention of implanted atoms, demonstrating the importance of nanocrystal density for achieving ambient temperature emission in these systems

  18. High dose, heavy ion implantation into metals: the use of sacrificial surface layers to enhance retention

    International Nuclear Information System (INIS)

    Clapham, L.

    1994-01-01

    While of considerable interest for the production of metallic alloys, high dose, heavy ion implantation is highly problematical, since the process is limited by sputtering effects. Sputtering is less significant, however, for light target materials, such as C and Al. This paper summarizes studies involving the use of light materials (such as C and Al) which act as slowly sputtering ''sacrificial layers'' when deposited on metallic targets prior to heavy ion implantation. The use of C and Al sacrificial coatings has enabled implanted ion retentions of 100% to be obtained in a number of ion-metal target systems, where the retentions in uncoated samples were as low as 20%. Ion implantation invariably leads to mixing at the sacrificial layer-metal target interface. This mixing may be detrimental in certain systems, so it is useful to be able to minimize or remove this mixed region. To achieve this, a number of techniques have been investigated: (1) removal of the mixed region in the latter stages of the implant; (2) using a barrier layer or chemical effects to minimize mixing at the sacrificial layer-metal interface; (3) choosing a sacrificial layer material which forms a mixed region which has desirable properties. The results of these investigations, for a number of different ion-target systems, are outlined in this paper. (orig.)

  19. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-15

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

  1. 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

    Objective: To explore the method for measuring and calculating both absorbed dose and effective dose received in organ and tissues of occupational workers by using TLDs for the implantation of 125 I seed sources. Methods The experiments with 60 Co γ-rays were carried out for the stability. A group of TLD chips was exposed to 125 I seed sources to establish standard dose curve for air kerma. During the 125 I seed implantation, the TLD chips were pasted to 13 locations like thyroid inside and outside the lead aprons worn by occupational workers to measure average absorbed dose and calculate the absorbed doses and effective to organs and tissues. Results: For 3 cases of prostate cancers with implantation of 125 I seeds, the worker's organs and tissues received the absorbed dose 0.02 -3.80 μ Gy and effective dose 0.06- 1.81 μSv outside lead aprons and the highest absorbed dose 2.35 μ Gy and effective 0.02 μSv inside lead aprons, respectively, with more than 65.9% of rays shielded. For 3 cases of brain cancers with implantation of 125 I seeds, the workers received the absorbed dose 0.23 - 11.31 μGy and effective dose 0.88-4.07 μSv outside lead aprons and the highest absorbed dose 2.22 μ Gy and effective dose 0.09 μSv inside lead aprons, respectively, with more than 54.5% of rays shielded. For 3 cases of lung cancers with implantation of 125 I seeds, the workers received the absorbed dose 0.03 - 14.78 μGy and effective dose 0.35 -7.59 μSv outside lead aprons and the highest absorbed dose 4.09 μGy and effective 0.22 μSv inside lead aprons, respectively, with more than 58.4% of rays shielded. For 2 cases of mediastinum cancers with implantation of 125 Iseeds, the workers received the absorbed dose 0.06 - 74.91 μGy and effective dose 0.83-17.96 μSv outside lead aprons and the highest absorbed dose 10.29 μGy and effective 0.5 μSv inside lead aprons, respectively, with more than 85% of rays shielded. For one case of ovary cancer with implantation of 125

  2. Cell Seeding Densities in Autologous Chondrocyte Implantation Techniques for Cartilage Repair.

    Science.gov (United States)

    Foldager, Casper Bindzus; Gomoll, Andreas H; Lind, Martin; Spector, Myron

    2012-04-01

    Cartilage repair techniques have been among the most intensively investigated treatments in orthopedics for the past decade, and several different treatment modalities are currently available. Despite the extensive research effort within this field, the generation of hyaline cartilage remains a considerable challenge. There are many parameters attendant to each of the cartilage repair techniques that can affect the amount and types of reparative tissue generated in the cartilage defect, and some of the most fundamental of these parameters have yet to be fully investigated. For procedures in which in vitro-cultured autologous chondrocytes are implanted under a periosteal or synthetic membrane cover, or seeded onto a porous membrane or scaffold, little is known about how the number of cells affects the clinical outcome. Few published clinical studies address the cell seeding density that was employed. The principal objective of this review is to provide an overview of the cell seeding densities used in cell-based treatments currently available in the clinic for cartilage repair. Select preclinical studies that have informed the use of specific cell seeding densities in the clinic are also discussed.

  3. Postimplantation Analysis Enables Improvement of Dose-Volume Histograms and Reduction of Toxicity for Permanent Seed Implantation

    International Nuclear Information System (INIS)

    Wust, Peter; Postrach, Johanna; Kahmann, Frank; Henkel, Thomas; Graf, Reinhold; Cho, Chie Hee; Budach, Volker; Boehmer, Dirk

    2008-01-01

    Purpose: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity. Patients and Methods: We evaluated 197 questionnaires completed by patients after permanent seed implantation (monotherapy between 1999 and 2003). For 70% of these patients, a computed tomography was available to perform postimplantation analysis. The index doses and volumes of the dose-volume histograms (DVHs) were determined and categorized with respect to the date of implantation. Differences in symptom scores relative to pretherapeutic status were analyzed with regard to follow-up times and DVH descriptors. Acute and subacute toxicities in a control group of 117 patients from an earlier study (June 1999 to September 2001) by Wust et al. (2004) were compared with a matched subgroup from this study equaling 110 patients treated between October 2001 and August 2003. Results: Improved performance, identifying a characteristic time dependency of DVH parameters (after implantation) and toxicity scores, was demonstrated. Although coverage (volume covered by 100% of the prescription dose of the prostate) increased slightly, high-dose regions decreased with the growing experience of the users. Improvement in the DVH and a reduction of toxicities were found in the patient group implanted in the later period. A decline in symptoms with follow-up time counteracts this gain of experience and must be considered. Urinary and sexual discomfort was enhanced by dose heterogeneities (e.g., dose covering 10% of the prostate volume, volume covered by 200% of prescription dose). In contrast, rectal toxicities correlated with exposed rectal volumes, especially the rectal volume covered by 100% of the prescription dose. Conclusion: The typical side effects occurring after permanent seed implantation can be reduced by improving the dose distributions. An improvement in dose distributions and a reduction of toxicities were identified with elapsed time between

  4. Implanted deuterium retention and release in carbon-coated beryllium

    International Nuclear Information System (INIS)

    Anderl, R.A.; Longhurst, G.R.; Pawelko, R.J.; Oates, M.A.

    1997-01-01

    Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 angstrom. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 angstrom revealed that exposure to a temperature of 400 degrees C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400 degrees C and an incident deuterium flux of approximately 6 X 10 19 D/m 2 sec), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples. 4 refs., 8 figs., 1 tab

  5. 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

  6. 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

  7. 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

  8. The Effect of Abutment Surface Roughness on the Retention of Implant-Supported Crowns Cemented with Provisional

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Abrisham

    2012-09-01

    Full Text Available Introduction: Surface roughness can increase the retention of castings by ridges and grooves that are microretentive. This study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement. Methods: Thirty solid abutments (ITI, 4 mm high, were divided into three groups randomly. In the first group, 10 abutments were roughened with sandblast (50-µm aluminum oxide and in the second group, 10 abutments were roughened with diamond bur. The third group had no surface treatment. Then, thirty implant fixture analogs (ITI were placed in the center of acrylic cylinders. After that a solid abutment was tightened on the each fixture analog with 35 N/cm force. Thirty base metal crowns were made on the 4 mm ITI abutment analogs using plastic coping. The prepared copings were cemented on the abutments by TempBond temporary cement and finally, crowns were pulled from the abutment in a universal test machine at a cross speed of 0.5cm/min. Results: The mean tensile strength in sandblasted, bur treated, and control group were 64.38±8, 91.37±7.19, and 58.61±1.93, respectively. Bur treated group showed higher tensile strength in comparison with two other groups. Conclusion: Surface modification of implant abutment by diamond bur may be an effective method to increase retention of crown when TempBond is used.

  9. Evaluation of dose-volume histograms after prostate seed implantation. 4-year experience

    International Nuclear Information System (INIS)

    Hoinkis, C.; Lehmann, D.; Winkler, C.; Herrmann, T.; Hakenberg, O.W.; Wirth, M.P.

    2004-01-01

    Background and purpose: permanent interstitial brachytherapy by seed implantation is a treatment alternative for low-volume low-risk prostate cancer and a complex interdisciplinary treatment with a learning curve. Dose-volume histograms are used to assess postimplant quality. The authors evaluated their learning curve based on dose-volume histograms and analyzed factors influencing implantation quality. Patients and methods: since 1999, 38 patients with a minimum follow-up of 6 months were treated at the authors' institution with seed implantation using palladium-103 or iodine-125, initially using the preplan method and later real-time planning. Postimplant CT was performed after 4 weeks. The dose-volume indices D90, V100, V150, the D max of pre- and postplans, and the size and position of the volume receiving the prescribed dose (high-dose volume) of the postplans were evaluated. In six patients, postplan imaging both by CT and MRI was used and prostate volumes were compared with preimplant transrectal ultrasound volumes. The first five patients were treated under external supervision. Results: patients were divided into three consecutive groups for analysis of the learning curve (group 1: n = 5 patients treated under external supervision; group 2: n = 13 patients; group 3: n = 20 patients). D90 post for the three groups were 79.3%, 74.2%, and 99.9%, the V100 post were 78.6%, 73.5%, and 88.2%, respectively. The relationship between high-dose volume and prostate volume showed a similar increase as the D90, while the relationship between high-dose volume lying outside the prostate and prostate volume remained constant. The ratio between prostate volumes from transrectal ultrasound and CT imaging decreased with increasing D90 post , while the preplanning D90 and V100 remained constant. The different isotopes used, the method of planning, and the implanted activity per prostate volume did not influence results. Conclusion: a learning curve characterized by an increase

  10. Patterns of failure after iodine-125 seed implantation for prostate cancer

    International Nuclear Information System (INIS)

    Lamb, David S.; Greig, Lynne; Russell, Grant L.; Nacey, John N.; Broome, Kim; Studd, Rod; Delahunt, Brett; Iupati, Douglas; Jain, Mohua; Rooney, Colin; Murray, Judy; Lamb, Peter J.; Bethwaite, Peter B.

    2014-01-01

    Purpose: To determine the site of relapse when biochemical failure (BF) occurs after iodine-125 seed implantation for prostate cancer. Materials and methods: From 2001–2009, 500 men underwent implantation in Wellington, New Zealand. Men who sustained BF were placed on relapse guidelines that delayed restaging and intervention until the prostate-specific antigen (PSA) was ⩾20 ng/mL. Results: Most implants (86%) had a prostate D90 of ⩾90%, and multivariate analysis showed that this parameter was not a variable that affected the risk of BF. Of 21 BFs that occurred, the site of failure was discovered to be local in one case and distant in nine cases. Restaging failed to identify the site of relapse in two cases. In nine cases the trigger for restaging had not been reached. Conclusions: If post-implant dosimetry is generally within the optimal range, distant rather than local failure appears to be the main cause of BF. Hormone treatment is therefore the most commonly indicated secondary treatment intervention (STI). Delaying the start of STI prevents the unnecessary treatment of men who undergo PSA ‘bounce’ and have PSA dynamics initially mimicking those of BF

  11. 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)

  12. 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

  13. 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.

  14. A greedy heuristic using adjoint functions for the optimization of seed and needle configurations in prostate seed implant

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Sua [Department of Radiation Oncology, Duke University Medical Center, Box 3295, Durham, NC 27710 (United States); Kowalok, Michael E [Department of Radiation Oncology, Virginia Commonwealth University Health System, 401 College St., PO Box 980058, Richmond, VA 23298-0058 (United States); Thomadsen, Bruce R [Department of Medical Physics, University of Wisconsin-Madison, 1530 MSC, 1300 University Ave., Madison, WI 53706 (United States); Henderson, Douglass L [Department of Engineering Physics, University of Wisconsin-Madison, 153 Engineering Research Bldg., 1500 Engineering Dr., Madison, WI 53706 (United States)

    2007-02-07

    We continue our work on the development of an efficient treatment-planning algorithm for prostate seed implants by incorporation of an automated seed and needle configuration routine. The treatment-planning algorithm is based on region of interest (ROI) adjoint functions and a greedy heuristic. As defined in this work, the adjoint function of an ROI is the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. Because seed positions are ranked in advance and because the greedy heuristic does not modify previously selected seed positions, the greedy heuristic constructs a complete seed configuration quickly. Isodose surface constraints determine the search space and the needle constraint limits the number of needles. This study additionally includes a methodology that scans possible combinations of these constraint values automatically. This automated selection scheme saves the user the effort of manually searching constraint values. With this method, clinically acceptable treatment plans are obtained in less than 2 min. For comparison, the branch-and-bound method used to solve a mixed integer-programming model took close to 2.5 h to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 100. This attribute makes this algorithm suitable for intra-operative real-time treatment planning.

  15. A greedy heuristic using adjoint functions for the optimization of seed and needle configurations in prostate seed implant

    International Nuclear Information System (INIS)

    Yoo, Sua; Kowalok, Michael E; Thomadsen, Bruce R; Henderson, Douglass L

    2007-01-01

    We continue our work on the development of an efficient treatment-planning algorithm for prostate seed implants by incorporation of an automated seed and needle configuration routine. The treatment-planning algorithm is based on region of interest (ROI) adjoint functions and a greedy heuristic. As defined in this work, the adjoint function of an ROI is the sensitivity of the average dose in the ROI to a unit-strength brachytherapy source at any seed position. The greedy heuristic uses a ratio of target and critical structure adjoint functions to rank seed positions according to their ability to irradiate the target ROI while sparing critical structure ROIs. Because seed positions are ranked in advance and because the greedy heuristic does not modify previously selected seed positions, the greedy heuristic constructs a complete seed configuration quickly. Isodose surface constraints determine the search space and the needle constraint limits the number of needles. This study additionally includes a methodology that scans possible combinations of these constraint values automatically. This automated selection scheme saves the user the effort of manually searching constraint values. With this method, clinically acceptable treatment plans are obtained in less than 2 min. For comparison, the branch-and-bound method used to solve a mixed integer-programming model took close to 2.5 h to arrive at a feasible solution. Both methods achieved good treatment plans, but the speedup provided by the greedy heuristic was a factor of approximately 100. This attribute makes this algorithm suitable for intra-operative real-time treatment planning

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-15

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

  17. Experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype for partial breast irradiation

    International Nuclear Information System (INIS)

    Ravi, Ananth; Caldwell, Curtis B.; Pignol, Jean-Philippe

    2008-01-01

    Previously, our team used Monte Carlo simulation to demonstrate that a gamma camera could potentially be used as an online image guidance device to visualize seeds during permanent breast seed implant procedures. This could allow for intraoperative correction if seeds have been misplaced. The objective of this study is to describe an experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype. The OGIPSI device is intended to be able to detect a seed misplacement of 5 mm or more within an imaging time of 2 min or less. The device was constructed by fitting a custom built brass collimator (16 mm height, 0.65 mm hole pitch, 0.15 mm septal thickness) on a 64 pixel linear array CZT detector (eValuator-2000, eV Products, Saxonburg, PA). Two-dimensional projection images of seed distributions were acquired by the use of a digitally controlled translation stage. Spatial resolution and noise characteristics of the detector were measured. The ability and time needed for the OGIPSI device to image the seeds and to detect cold spots was tested using an anthropomorphic breast phantom. Mimicking a real treatment plan, a total of 52 103 Pd seeds of 65.8 MBq each were placed on three different layers at appropriate depths within the phantom. The seeds were reliably detected within 30 s with a median error in localization of 1 mm. In conclusion, an OGIPSI device can potentially be used for image guidance of permanent brachytherapy applications in the breast and, possibly, other sites

  18. SLM Produced Porous Titanium Implant Improvements for Enhanced Vascularization and Osteoblast Seeding

    Directory of Open Access Journals (Sweden)

    Julia Matena

    2015-04-01

    Full Text Available To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF, high mobility group box 1 (HMGB1 and chemokine (C-X-C motif ligand 12 (CXCL12. As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI. Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release.

  19. SLM Produced Porous Titanium Implant Improvements for Enhanced Vascularization and Osteoblast Seeding

    Science.gov (United States)

    Matena, Julia; Petersen, Svea; Gieseke, Matthias; Kampmann, Andreas; Teske, Michael; Beyerbach, Martin; Murua Escobar, Hugo; Haferkamp, Heinz; Gellrich, Nils-Claudius; Nolte, Ingo

    2015-01-01

    To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release. PMID:25849656

  20. Bypassing the learning curve in permanent seed implants using state-of-the-art technology

    International Nuclear Information System (INIS)

    Beaulieu, Luc; Evans, Dee-Ann Radford; Aubin, Sylviane; Angyalfi, Steven; Husain, Siraj; Kay, Ian; Martin, Andre-Guy; Varfalvy, Nicolas; Vigneault, Eric; Dunscombe, Peter

    2007-01-01

    Purpose: The aim of this study was to demonstrate, based on clinical postplan dose distributions, that technology can be used efficiently to eliminate the learning curve associated with permanent seed implant planning and delivery. Methods and Materials: Dose distributions evaluated 30 days after the implant of the initial 22 consecutive patients treated with permanent seed implants at two institutions were studied. Institution 1 (I1) consisted of a new team, whereas institution 2 (I2) had performed more than 740 preplanned implantations over a 9-year period before the study. Both teams had adopted similar integrated systems based on three-dimensional (3D) transrectal ultrasonography, intraoperative dosimetry, and an automated seed delivery and needle retraction system (FIRST, Nucletron). Procedure time and dose volume histogram parameters such as D90, V100, V150, V200, and others were collected in the operating room and at 30 days postplan. Results: The average target coverage from the intraoperative plan (V100) was 99.4% for I1 and 99.9% for I2. D90, V150, and V200 were 191.4 Gy (196.3 Gy), 75.3% (73.0%), and 37.5% (34.1%) for I1 (I2) respectively. None of these parameters shows a significant difference between institutions. The postplan D90 was 151.2 Gy for I1 and 167.3 Gy for I2, well above the 140 Gy from the Stock et al. analysis, taking into account differences at planning, results in a p value of 0.0676. The procedure time required on average 174.4 min for I1 and 89 min for I2. The time was found to decrease with the increasing number of patients. Conclusion: State-of-the-art technology enables a new brachytherapy team to obtain excellent postplan dose distributions, similar to those achieved by an experienced team with proven long-term clinical results. The cost for bypassing the usual dosimetry learning curve is time, with increasing team experience resulting in shorter treatment times

  1. Small-diameter dental implants: An adjunct for retention, stability, and comfort for the edentulous patient

    Directory of Open Access Journals (Sweden)

    Antonio Scarano

    2012-10-01

    Full Text Available Aim: Studies have shown that mandibular implant overdentures significantly increase satisfaction and quality of life of edentulous elders. Improved chewing ability appears to have a positive impact on nutritional state. Materials and methods: Forty edentulous subjects received four permucosal mini-implants for overdentures in the interforamina region of the mandible. Almost all participants were still satisfied with their overdentures. Participant satisfaction concerning retention and stability of the mandibular overdenture was assessed. A micro invasive technique was adopted, without open flap and performed in one chirurgical step; this technique can be used also in the so-called “highrisk” patients (anticoagulant terapy, diabetes, etc. Results and conclusion: Results and conclusion The results suggest that a mandibular overdenture retained by 4 mini-implants may be the best treatment strategy for edentulous people with atrophic ridges. The use of mini-implants is in many cases a good clinical alternative to the use of larger diameter implants, in that they enable to reduce surgical time, bleeding, postoperative discomfort and healing time.

  2. 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 

  3. Quality control of system of imaging for rectal ultrasound for implants seed prostate low rate

    International Nuclear Information System (INIS)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-01-01

    In this work, the objective is the evaluation of the image system used in implants of prostate of low rate held at our hospital, for maximum control on the placement of the seeds in the patient and therefore carried out dosimetry. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. 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)

  6. Iodine-125 seed implantation (permanent brachytherapy) for clinically localized prostate cancer

    International Nuclear Information System (INIS)

    Ebara, Shin; Katayama, Yoshihisa; Tanimoto, Ryuta

    2008-01-01

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

  7. 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)

  8. Occupational exposure in prostate permanent implants with I-125 seeds

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    Liu, D; Usmani, N; Sloboda, R; Meyer, T; Husain, S; Angyalfi, S; Kay, I

    2014-01-01

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

  10. 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

  11. Evaluation of the Effect of Axial Wall Modification and Coping Design on the Retention of Cement-retained Implant-supported Crowns

    Science.gov (United States)

    Derafshi, Reza; Ahangari, Ahmad Hasan; Torabi, Kianoosh; Farzin, Mitra

    2015-01-01

    Background and aims. Because of compromised angulations of implants, the abutments are sometimes prepared. The purpose of this study was to investigate the effect of removing one wall of the implant abutment on the retention of cement-retained crowns. Materials and methods. Four prefabricated abutments were attached to analogues and embedded in acrylic resin blocks. The first abutment was left intact. Axial walls were partially removed from the remaining abutments to produce abutments with three walls. The screw access channel for the first and second abutments were completely filled with composite resin. For the third and fourth abutments, only partial filling was done. Wax-up models were made by CAD/CAM. Ten cast copings were fabricated for each abutment. The copings of fourth abutment had an extension into the screw access channel. Copings were cemented with Temp Bond. The castings were removed from the abutment using an Instron machine, and the peak removal force was recorded. A one-way ANOVA was used to test for a significant difference followed by the pairwise comparisons. Results. The abutments with opened screw access channel had a significantly higher retention than the two other abutments. The abutment with removed wall and no engagement into the hole by the castings exhibited the highest retention. Conclusion. Preserving the opening of screw access channel significantly increases the retention where one of the axial walls of implant abutments for cement-retained restorations is removed during preparation. PMID:25973152

  12. Evaluation of radioactive seeds implantation under PET-CT guidance for the treatment of central lung cancer with obstructive atelectasis

    International Nuclear Information System (INIS)

    Zhou Yi; Jiang Zhongpu; Wang Haiting; Zhang Yanjun; Jiang Qiang; Wang Jun; Ren Lijun; Xie Bin

    2010-01-01

    Objective: To evaluate percutaneous puncturing 125 I seed implantation by using PET-CT guided target localization technique in treating central lung cancer complicated by obstructive pulmonary atelectasis. Methods: A total of 30 patients with suspected central lung cancer complicated by obstructive pulmonary atelectasis on preoperative chest films were enrolled in this study. As no clear distinction existed between the tumor and the atelectatic consolidation shadow on plain chest films, CT scanning was carried out in all patients. If CT scan was still not able to determine the margin of the tumor, an additional PET-CT scanning was adopted. After ascertaining the location of the lung cancer, percutaneous puncturing implantation of 125 I seeds under PET-CT guidance was performed. The clinical data and the therapeutic results were evaluated. Results: A sharp distinction between the tumor and the atelectatic consolidation shadow was demonstrated on PET-CT scans in 21 cases. The mean volume of the targeted lesion reckoned from PET-CT scans was 26 cm 3 , and the 125 I seeds were implanted. The mean volume of the targeted lesion calculated on CT scans was 37 cm 3 . Six months after the treatment, the follow-up CT exam showed that the effective rate was 93% (28/30). The one-year survival rate was 100% . The complications included pneumothorax (n = 8), small amount of hemoptysis (n = 12) and fever (n = 2). No displacement or immigration of the implanted seeds occurred. Conclusion: PET-CT scanning is far superior to conventional CT scanning in determining the target area of the tumor in patients with central lung cancer complicated by obstructive pulmonary atelectasis. (authors)

  13. 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)

  14. The Effect of Abutment Surface Roughness on the Retention of Implant-Supported Crowns Cemented with Provisional Luting Cement

    Directory of Open Access Journals (Sweden)

    Jalil Ganbarzadeh

    2013-01-01

    Full Text Available Introduction: Surface roughness can increase the retention of castings by ridges and grooves that are microretentive. This study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement. Methods: Thirty solid abutments (ITI, 4 mm high, were divided into three groups randomly. In the first group, 10 abutments were roughened with sandblast (50-µm aluminum oxide and in the second group, 10 abutments were roughened with diamond bur. The third group had no surface treatment. Then, thirty implant fixture analogs (ITI were placed in the center of acrylic cylinders. After that a solid abutment was tightened on the each fixture analog with 35 N/cm force. Thirty base metal crowns were made on the 4 mm ITI abutment analogs using plastic coping. The prepared copings were cemented on the abutments by TempBond temporary cement and finally, crowns were pulled from the abutment in a universal test machine at a cross speed of 0.5cm/min. Results: The mean tensile strength in sandblasted, bur treated, and control group were 64.38±8, 91.37±7.19, and 58.61±1.93, respectively. Bur treated group showed higher tensile strength in comparison with two other groups. Conclusion: Surface modification of implant abutment by diamond bur may be an effective method to increase retention of crown when TempBond is used.

  15. Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded allograft

    Directory of Open Access Journals (Sweden)

    J O Eniwumide

    2007-08-01

    Full Text Available Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as controls and the experimental groups comprised autologous bone marrow derived stem cell seeded allograft, biphasic calcium phosphate (BCP and tricalcium phosphate (TCP, respectively. All implants were implanted in the back muscle of adult Dutch milk goats for 12 weeks. Micro-computed tomography (µCT analysis and histomorphometry was performed to evaluate and quantify ectopic bone formation. In good agreement, both µCT and histomorphometric analysis demonstrated a significant increase in bone formation by cell-seeded calcium phosphate scaffolds as compared to the autograft, allograft and cell-seeded allograft implants. An extensive resorption of the autograft, allograft and cell-seeded allograft implants was observed by histology and confirmed by histomorphometry. Cell-seeded TCP implants also showed distinct signs of degradation with histomorphometry and µCT, while the degradation of the cell-seeded BCP implants was negligible. These results indicate that cell-seeded calcium phosphate scaffolds are superior to autograft, allograft or cell-seeded allograft in terms of bone formation at ectopic implantation sites. In addition, the usefulness of µCT for the efficient and non-destructive analysis of mineralised bone and calcium phosphate scaffold was demonstrated.

  16. The metabolism of 32P-CP-PLLA seed implanted in the liver and its damage to the normal liver tissue: a study in the experimental dogs

    International Nuclear Information System (INIS)

    Tan Zhongbao; Liu Lu; Guo Jinhe; Zhu Guangyu; Wang Fuan; Nie Qi; Gao Hailin; Teng Gaojun

    2010-01-01

    Objective: To investigate the effects of intratumoral implantation of 32 P -CP-PLLA seeds on the normal canine liver tissue and to explore the metabolism of 32 P-CP-PLLA seeds implanted in the liver of experimental dogs. Methods: Twelve beagles were enrolled in this study. The dogs were randomly and equally divided into four groups: group A (185 MBq), group B (370 MBq), group C (740 MBq) and group D (0 MBq). By using laparotomy procedure 32 P-CP-PLLA seeds were implanted into dog's liver. CT scan was performed before operation as well as before the dog was sacrificed. All dogs were sacrificed three months after the implantation. Before the procedure and 1, 2, 4, 8 and 12 weeks after the procedure the blood tests and serum biochemical tests were conducted. One dog from group B and group C was selected respectively and was fed in a metabolic cage. Within one month after the procedure the cpm in feces and in urine was determined every 24 hours. One dog was picked out from each of the three groups and was punctured to get its liver tissue for pathologic exam each time at 1, 2, 4, 8 and 12 weeks after the implantation, and SPECT imaging was also performed at the same time. Pathologic study, both macroscopic and microscopic (including optical and electronic microscopy) was made to observe the liver damage after the dog was sacrificed. The statistical analysis was processed by using SPSS 13.0 software and the measuring data were expressed with mean ± standard deviation (x ± s). Results: Two months after the procedure, serological examination found that the serum alkaline phosphatase (BKP) in both group B and group C was significantly higher than that in other groups, the difference was statistically significant (P 32 P-CP-PLLA seeds was manifested as a spherical lesion which was encysted by a layer of fibrous tissue with an edematous zone peripherally. Conclusion: The implantation of 32 P-CP-PLLA seeds in dog's liver causes only localized hepatic damage with no general

  17. Patient retention and replacement trends after saline breast implants: are deflations inflationary?

    Science.gov (United States)

    Stevens, W Grant; Pacella, Salvatore J; Hirsch, Elliot; Stoker, David A

    2009-01-01

    This study aimed to examine serial operative trends with patients who have experienced surgical implant deflation. In addition, the economic impact of deflation on practice caseload was analyzed. A retrospective review was conducted to examine patients who experienced deflation from 2000 to 2007. Patient demographics, implant data, and the presence of secondary (performed at explantation) or tertiary (performed later) procedures were examined. Financial information was tabulated to determine the economic multiplier effect (i.e. the expected value of revenue from secondary and tertiary procedures divided by explantation cost) of taking on deflation cases in a practice. For this study, 285 patients with an average age of 38.4 years were identified. The average time to explantation was 50 months. Slightly more than half of the patients (55%) had both implants replaced at the time of explantation, whereas 59% switched to silicone implants and 41% continued with saline implants. A larger implant was chosen by 54% of the patients (average increase, 82 ml), whereas 18% underwent secondary procedures at the time of explantation including mastopexy (n = 22), facial rejuvenation (n = 8), liposuction (n = 7), or a combination of the two (n = 8). Tertiary procedures were performed for 31% of the patients after their explantation/reimplantation (average time frame, 13 months). The tertiary procedures included replacement with silicone (33.7%), liposuction (24.7%), abdominoplasty (11.2%), facial rejuvenation (13.5%), or nonsurgical rejuvenation using Botox, Restylane, or laser procedure (33.7%). Economic multiplier analysis showed that the financial impact of revenue derived from implant deflation on downstream practice revenue is 1.02. At the time of explantation, replacement with silicone after saline deflation is common (59% of patients). In this study, patients who chose replacement with saline had a significant tendency to replace with silicone (33%) as a tertiary procedure

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

    Directory of Open Access Journals (Sweden)

    Shen X

    2015-05-01

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

  19. Sci-Thur PM – Brachytherapy 02: Positional accuracy in Pd-103 permanent breast seed implant (PBSI) brachytherapy at the Tom Baker Cancer Centre (TBCC)

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, Amy; Watt, Elizabeth; Peacock, Michael; Husain, Siraj; Meyer, Tyler; Roumeliotis, Michael [University of Calgary, Tom Baker Cancer Centre (Canada)

    2016-08-15

    Purpose: This retrospective study aims to quantify the positional accuracy of seed delivery in permanent breast seed implant (PBSI) brachytherapy at the Tom Baker Cancer Centre (TBCC). Methods: Treatment planning and post-implant CT scans for 5 patients were rigidly registered using the MIM Symphony™ software (MIM Software, Cleveland, OH) and used to evaluate differences between planned and implanted seed positions. Total and directional seed displacements were calculated for each patient in a clinically relevant ‘needle coordinate system’, defined relative to the angle of fiducial needle insertion. Results: The overall average total seed displacement was 10±8 mm. Systematic seed displacements were observed in individual patients and the magnitude and direction of these offsets varied among patients. One patient showed a significant directional seed displacement in the shallow-deep direction compared with the other four patients. With the exception of this one patient outlier, no significant systematic directional displacements in the needle coordinate system were observed for this cohort; the average directional displacements were −1±5 mm, 2±3 mm, and −2±4 mm in the shallow-deep, up-down, and right-left directions respectively. Conclusion: With the exception of one patient outlier, the magnitude of seed displacements were relatively consistent among patients. The results indicate that the shallow-deep direction possesses the largest uncertainty for the seed delivery method used at the TBCC. The relatively large uncertainty in seed placement in this direction is expected, as this is the direction of needle insertion. Further work will involve evaluating deflections of delivered needle tracks from their planned positions.

  20. The biocompatibility of titanium cardiovascular devices seeded with autologous blood-derived endothelial progenitor cells: EPC-seeded antithrombotic Ti implants.

    Science.gov (United States)

    Achneck, Hardean E; Jamiolkowski, Ryan M; Jantzen, Alexandra E; Haseltine, Justin M; Lane, Whitney O; Huang, Jessica K; Galinat, Lauren J; Serpe, Michael J; Lin, Fu-Hsiung; Li, Madison; Parikh, Amar; Ma, Liqiao; Chen, Tao; Sileshi, Bantayehu; Milano, Carmelo A; Wallace, Charles S; Stabler, Thomas V; Allen, Jason D; Truskey, George A; Lawson, Jeffrey H

    2011-01-01

    Implantable and extracorporeal cardiovascular devices are commonly made from titanium (Ti) (e.g. Ti-coated Nitinol stents and mechanical circulatory assist devices). Endothelializing the blood-contacting Ti surfaces of these devices would provide them with an antithrombogenic coating that mimics the native lining of blood vessels and the heart. We evaluated the viability and adherence of peripheral blood-derived porcine endothelial progenitor cells (EPCs), seeded onto thin Ti layers on glass slides under static conditions and after exposure to fluid shear stresses. EPCs attached and grew to confluence on Ti in serum-free medium, without preadsorption of proteins. After attachment to Ti for 15 min, less than 5% of the cells detached at a shear stress of 100 dyne / cm(2). Confluent monolayers of EPCs on smooth Ti surfaces (Rq of 10 nm), exposed to 15 or 100 dyne/cm(2) for 48 h, aligned and elongated in the direction of flow and produced nitric oxide dependent on the level of shear stress. EPC-coated Ti surfaces had dramatically reduced platelet adhesion when compared to uncoated Ti surfaces. These results indicate that peripheral blood-derived EPCs adhere and function normally on Ti surfaces. Therefore EPCs may be used to seed cardiovascular devices prior to implantation to ameliorate platelet activation and thrombus formation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Effect of bar cross-section and female housing material on retention of mandibular implant bar overdentures: A comparative in vitro study

    Directory of Open Access Journals (Sweden)

    Elsayed A Abdel-Khalek

    2017-01-01

    Conclusions: Within the limitation of this in vitro study and for a similar period of service, heat-cured silicone female housing for Hader bar could maintain greater retention for two-implant-retained overdentures than provided by conventional plastic clip after 1.5 year. The oval bar recorded reasonable initial retention values and maintained these values for 1.5 years of service.

  2. 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)

  3. 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

  4. Role of wall implantation of charge exchange neutrals in the deuterium retention for Tore Supra long discharges

    International Nuclear Information System (INIS)

    Tsitrone, E.; Reiter, D.; Loarer, T.; Brosset, C.; Bucalossi, J.; Begrambekov, L.; Grisolia, C.; Grosman, A.; Gunn, J.; Hogan, J.; Mitteau, R.; Pegourie, B.; Ghendrih, P.; Reichle, R.; Roubin, P.

    2005-01-01

    In Tore Supra long pulses, particle balance gives evidence that a constant fraction of the injected gas (typically 50%) is retained in the wall for the duration of the shot, showing no sign of wall saturation after more than 6 min of discharge. During the discharge, the retention rate first decreases (phase 1), then remains constant throughout the pulse (phase 2). Phase 1 could be interpreted as implantation of particles combined with a constant codeposition rate, while phase 2 could correspond to codeposition alone, once the implanted surfaces are saturated with deuterium. This paper presents a possible contribution of charge exchange neutrals to the implantation process, based on modelling results with the Eirene neutral transport code. A complex pattern of particle implantation is evidenced, with saturation time constants ranging from less than one to several hundreds seconds, compatible with the experimental behaviour during phase 1

  5. 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)

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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)

  8. Description and features of a technique of seeds implantation with 3D real time planning connected to an automatic afterloading and quality control device

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Seidal, M.; Cantera de Frutos, C.

    2002-07-01

    According to statistics, 9% of males older than 50 years will develop prostate cancer and 33% of them will finally die of their disease. Detection can be based on digital rectal examination, tumoral markers measurements as PSA (Prostate Specific Antigen). CT/MR or Ultra sound imaging. Treatments may be radical prostatectomy (usually combined with chemotherapy), external radiation therapy, brachytherapy, or a combination of the former two techniques. In the last years permanent seed implantation is becoming an attractive alternative for treatment of prostate cancer at early stages, either as monotherapy (total prescribed dose of 145 Gy) or as an additional boost after external beam irradiation (95-100Gy after external beam delivery of 50Gy). But not all cases are suitable for seed treatment. Tumors must be at an early state and not very active (low tumoral markers values), without extra-capsular spreading and no metastasis in surrounding area. There must be no trans-urethral resection, no calcifications nor public arc interference and, finally, the volume should not be bigger than 50 cm''3. The technique consists on the permanent implantation of radioactive seeds into the prostate that, while decaying, will deliver the prescribed dose to the tumor. Isotopes mostly used are I-125 and Pd-103. Procedures for seed implantation vary but traditional ones generally imply two stages. The first one is the manual pre-loading of needles which can be performed either by composing loose seeds and spacers, either by cutting off strands of seeds and re absorbable spacers. This process can be done according to a previously approved pre plan or based on the accumulated experience about the number of needles and loading usually needed. Second stage consist on the implantation of these preloaded needles on the operation room. (Author)

  9. Influence of bone marrow-derived mesenchymal stem cells pre-implantation differentiation approach on periodontal regeneration in vivo.

    Science.gov (United States)

    Cai, Xinjie; Yang, Fang; Yan, Xiangzhen; Yang, Wanxun; Yu, Na; Oortgiesen, Daniel A W; Wang, Yining; Jansen, John A; Walboomers, X Frank

    2015-04-01

    The implantation of bone marrow-derived mesenchymal stem cells (MSCs) has previously been shown successful to achieve periodontal regeneration. However, the preferred pre-implantation differentiation strategy (e.g. maintenance of stemness, osteogenic or chondrogenic induction) to obtain optimal periodontal regeneration is still unknown. This in vivo study explored which differentiation approach is most suitable for periodontal regeneration. Mesenchymal stem cells were obtained from Fischer rats and seeded onto poly(lactic-co-glycolic acid)/poly(ɛ-caprolactone) electrospun scaffolds, and then pre-cultured under different in vitro conditions: (i) retention of multilineage differentiation potential; (ii) osteogenic differentiation approach; and (iii) chondrogenic differentiation approach. Subsequently, the cell-scaffold constructs were implanted into experimental periodontal defects of Fischer rats, with empty scaffolds as controls. After 6 weeks of implantation, histomorphometrical analyses were applied to evaluate the regenerated periodontal tissues. The chondrogenic differentiation approach showed regeneration of alveolar bone and ligament tissues. The retention of multilineage differentiation potential supported only ligament regeneration, while the osteogenic differentiation approach boosted alveolar bone regeneration. Chondrogenic differentiation of MSCs before implantation is a useful strategy for regeneration of alveolar bone and periodontal ligament, in the currently used rat model. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. 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

    Objective: To investigate the application value of early evaluation and monitoring of 125 I interstitial implantation in a pancreatic cancer xenograft. Methods: Xenograft models were created by subcutaneous injection of Sw 1990 human pancreatic cancer cell suspensions into the right hind limbs of the immunodeficient BABL/c nude mice. The tumors size were about 8-10 mm after two weeks. The mice were randomly divided into 3 groups,including control group (n=4), empty seed implantation group (n=4) and 125 I implantation group (n=4). Before treatment and one week after treatment, 18 F-FDG Micro-PET/CT scan was performed and then maximum standardized uptake values (SUV max ), mean standardized uptake values (SUV mean ), tumor size and necrosis rate were measured. HE staining and TK1 immunohistochemistry examination were carried out in the paraffin-embedded sample. Results: Before treatment the SUV max and SUV mean values of three groups did not reach statistical significance. One week after treatment the SUV max and SUV mean values of three groups were 3.53±1.20 and 0.57±0.26 vs. 3.83±2.13 and 0.59 ±0.24 vs. 0.29±0.23 and 0.016±0.001, respectively, with a significant difference (F=7.62, P=0.01; F=10.34, P=0.005). The SUV max and SUV mean values of 125 I implant group were significantly lower than empty seed implant group and control group and were significantly lower than before treatment. Before treatment, tumor necrosis rate of three groups were not significantly different. Immunohistochemical staining found the TK1 positive staining index of three groups were respectively (64.25±1.71)%, (62.25±2.22)% and (38.25±1.71)% with statistically significant difference (F=233.67, P<0.001). The TK1 positive staining index of 125 I implant group was significantly lower than empty seed implant group and control group. The SUV max values had some positive correlation with TK1 positive staining index (r=0.85, P=0.001). Conclusions: 18 F-FDG Micro-PET/CT may be useful as a

  11. SU-E-T-301: Dosimetric Comparison Between Adaptive and Rectilinear Template-Based Prostate Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Sugar, E Neubauer; Buzurovic, I; O’Farrell, D; Hansen, J; Devlin, P; Cormack, R; Nguyen, P [Brigham and Women’s Hospital, Boston, MA (United States)

    2015-06-15

    Purpose: To compare the dosimetry of a standard rectilinear and an adaptive technique used in I125 prostate seed implants. Methods: To achieve favorable dosimetry in prostate implants we used adaptive needle updates to match actual positions in real-time. The seed locations were optimized based on actual needle locations. The seeds were delivered automatically with a robotic device seedSelectron™ (Elekta Brachytherapy). In this study, we evaluated the former approach against the standard rectilinear technique in which the needles have a parallel distribution. The treatment plans for 10 patients were analyzed. For comparison, the actual treatment plans were revised so each needle was repositioned to its original parallel location through the template. The analysis was performed by comparing the target coverage and dose to the organs at risk. The comparison was done using the following planning goals: the target D90> 90%, V100% > 90%, V50% <70% and V200% <30%; the urethra V125% < 1cm3 and V150%= 0cm3; and the Rectum V100%<1cm3 and V69% < 8cm3. The prescription dose to the target was 145Gy. Results: The average target volume and number of seeds were 44.39cm3(SD=11.14) and 74(SD=12), respectively. The D90 for adaptive and rectilinear plans was 159.9Gy(SD=2.99) and 155.53Gy(SD=4.04) resulting in a 2.74% difference for the average target coverage. A similar difference (1.75%) was noticed in the target V100[%]. No significant difference was noticed in the dose to the urethra and rectum. All planning goals were met with both the adaptive and rectilinear approach for each plan. Conclusion: The study reveals enhanced coverage of the target when using the adaptive needle adjustments as compared to the rectilinear approach for the analyzed cases. However, the differences in dosimetry did not translate to meaningful clinical outcomes.

  12. An in vitro investigation into retention strength and fatigue resistance of various designs of tooth/implant supported overdentures.

    Science.gov (United States)

    Fatalla, Abdalbseet A; Song, Ke; Du, Tianfeng; Cao, Yingguang

    2012-02-01

    Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440

  13. 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

  14. SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W [Sunnybrook Health Sciences Center, Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Safigholi, H; Soliman, A [Sunnybrook Research Institute, Toronto, ON (Canada)

    2016-06-15

    Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

  15. SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

    International Nuclear Information System (INIS)

    Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W; Safigholi, H; Soliman, A

    2016-01-01

    Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

  16. A radioactive seed implant on a rabbit's liver following a voxel model representation for dosimetric proposals

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Tarcisio P.R.; Andrade, Joao Paulo Lopes de; Costa, Igor Temponi; Teixeira, Cleuza H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares]. E-mail: campos@nuclear.ufmg

    2005-07-01

    Animal models have been used in experimentation with ionizing radiation. The evaluation of the energy absorbed per unit tissue mass in vivo transported by nuclear particles is a task to be performed before experimentation. Stochastic or deterministic methodology can be applied, however the dosimetric protocols applied in radiotherapy center cannot be applied directly due to the inherent small geometry and chemical composition of the animal distinct from human. The present article addresses a method in development that will predict the dose distribution into the rabbit thorax based on the solution of the transport phenomena in a voxel model. The model will be applied to simulate a seed implant experiment on a rabbit. Herein, the construction of the three-dimensional voxel model anthropomorphic -anthropometrics to the rabbit is presented. The model is assembling from a set of computer tomography of the rabbit. The computational phantom of the thorax starts at the digitalisation of the CT images, tissue definition, and color image representation of each tissue and organ. The chemical composition and mass density of each tissue is evaluated as similar date presented by ICRU-44. To treat the images, a code namely SISCODES, developed in house, was used. The in vivo experiment that will be simulated is also described. That is a implant of five seeds of 1.6x2 mm performed in a rabbit's liver. The perspective of this work is the application of the model in dosimetric studies predicting the dose distribution around the seed's implanted in vivo experiments. (author)

  17. 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.

  18. Comparative Evaluation of Retentive Properties of Two Compatible Ball Attachments in Mandibular Implant-Retained Overdentures: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Maryam Memarian

    2018-02-01

    Full Text Available Objectives: The retentive properties of implant-retained overdentures (IRO may be influenced by the type of attachments. The aim of this research was to compare the retention of two dental implant systems with compatible ball attachments, namely Straumann® system (SS and Rhein83 SRL system (RS after fatigue testing.Materials and Methods: Two laboratory models consisting of two parallel Straumann® fixtures at a distance of 22 mm were prepared. Five pairs of each systems' ball attachments were examined (n=5. The samples were soaked in artificial saliva. The retention strength values (RSV were recorded before the fatigue test and after 1100, 2200, 3300, 4400, and 5500 insertion and removal cycles at a speed of 51 mm/minute with a 50-N load cell in a universal testing machine. The data were analyzed by repeated measures analysis of variance (ANOVA followed by independent sample t-test with Bonferroni corrections.Results: There was a decrease in the RSV in both systems after 5500 cycles of insertion and removal. There was a significant statistical difference between the RSV of the normal Sphero Block of the RS (17.52±0.68 N and that of the Spare Lamella retention inserts of the SS (19.72±0.74 N, P=0.001.Conclusions: Although the RSVs of the RS and SS were almost similar before the fatigue test, as the number of insertion and removal cycles increased, the RSV decreased more significantly in the RS compared to the SS.

  19. Retention of neon in graphite after ion beam implantation or exposures to the scrape-off layer plasma in the TEXTOR tokamak

    International Nuclear Information System (INIS)

    Kim, Y.M.; Philipps, V.; Rubel, M.; Vietzke, E.; Pospieszczyk, A.; Unterberg, B.; Jaspers, R.

    2002-01-01

    The interaction of neon ions with graphite was investigated for targets either irradiated with ion beams (2-10 keV range) or exposed to the scrape-off layer plasma in the TEXTOR tokamak during discharges with neon edge cooling. The emphasis was on the influence of the target temperature (300-1200 K) and the implantation dose on the neon retention and reemission. The influence of deuterium impact on the retention of neon implanted into graphite has also been addressed. In ion beam experiments saturation is observed above a certain ion dose with a saturation level, which decreases with increasing target temperature. The temperature dependence of the thermal desorption corresponds to an apparent binding energy of about 2.06 eV. The retention of neon (C Ne /C C ) decreases with increasing ion energy with values from 0.55 to 0.15 following irradiation with 2 and 10 keV ions, respectively. The reemission yield during the irradiation increases with target temperature and above 1200 K all impinging ions are reemitted instantaneously. The retention densities measured using the sniffer probe at the TEXTOR tokamak are less than 1% of the total neon fluence and are over one order of magnitude smaller than those observed in ion beam experiments. The results are discussed in terms of different process decisive for ion deposition and release under the two experimental conditions

  20. The Not-So-Good Prognosis of Streptococcal Periprosthetic Joint Infection Managed by Implant Retention : The Results of a Large Multicenter Study

    NARCIS (Netherlands)

    Lora-Tamayo, Jaime; Senneville, Éric; Ribera, Alba; Bernard, Louis; Dupon, Michel; Zeller, Valérie; Li, Ho Kwong; Arvieux, Cédric; Clauss, Martin; Uçkay, Ilker; Vigante, Dace; Ferry, Tristan; Iribarren, José Antonio; Peel, Trisha N; Sendi, Parham; Miksic, Nina Gorišek; Rodríguez-Pardo, Dolors; Del Toro, María Dolores; Fernández-Sampedro, Marta; Dapunt, Ulrike; Huotari, Kaisa; Davis, Joshua S; Palomino, Julián; Neut, Danielle; Clark, Benjamin M; Gottlieb, Thomas; Trebše, Rihard; Soriano, Alex; Bahamonde, Alberto; Guío, Laura; Rico, Alicia; Salles, Mauro J C; Pais, M José G; Benito, Natividad; Riera, Melchor; Gómez, Lucía; Aboltins, Craig A; Esteban, Jaime; Horcajada, Juan Pablo; O'Connell, Karina; Ferrari, Matteo; Skaliczki, Gábor; Juan, Rafael San; Cobo, Javier; Sánchez-Somolinos, Mar; Ramos, Antonio; Giannitsioti, Efthymia; Jover-Sáenz, Alfredo; Baraia-Etxaburu, Josu Mirena; Barbero, José María

    2017-01-01

    Background.: Streptococci are not an infrequent cause of periprosthetic joint infection (PJI). Management by debridement, antibiotics, and implant retention (DAIR) is thought to produce a good prognosis, but little is known about the real likelihood of success. Methods.: A retrospective,

  1. SU-G-JeP1-10: Feasibility of CyberKnife Tracking Using the Previously-Implanted Permanent Brachytherapy Seed Cloud

    International Nuclear Information System (INIS)

    Cheung, J; Cunha, J; Sudhyadhom, A; McGuinness, C; Roach, M; Descovich, M

    2016-01-01

    Purpose: Robotic radiosurgery is a salvage treatment option for patients with recurrent prostate cancer. We explored the feasibility of tracking the bolus of permanent prostate implants (PPI) using image recognition software optimized to track spinal anatomy. Methods: Forty-five inert iodine seeds were implanted into a gelatin-based prostate phantom. Four superficial gold seeds were inserted to provide ground-truth alignment. A CT scan of the phantom (120 kVp, 1 mm slice thickness) was acquired and a single-energy iterative metal artifact reduction (MAR) algorithm was used to enhance the quality of the DRR used for tracking. CyberKnife treatment plans were generated from the MAR CT and regular CT (no-MAR) using spine tracking. The spine-tracking grid was centered on the bolus of seeds and resized to encompass the full seed cloud. A third plan was created from the regular CT scan, using fiducial tracking based on the 4 superficial gold seeds with identical align-center coordinates. The phantom was initially aligned using the fiducial-tracking plan. Then the MAR and no-MAR spine-tracking plans were loaded without moving the phantom. Differences in couch correction parameters were recorded in the case of perfect alignment and after the application of known rotations and translations (roll/pitch of 2 degrees; translations XYZ of 2 cm). Results: The spine tracking software was able to lock on to the bolus of seeds and provide couch corrections both in the MAR and no-MAR plans. In all cases, differences in the couch correction parameters from fiducial alignment were <0.5 mm in translations and <1 degree in rotations. Conclusion: We were able to successfully track the bolus of seeds with the spine-tracking grid in phantom experiments. For clinical applications, further investigation and developments to adapt the spine-tracking algorithm to optimize for PPI seed cloud tracking is needed to provide reliable tracking in patients. One of the authors (MD) has received research

  2. SU-G-JeP1-10: Feasibility of CyberKnife Tracking Using the Previously-Implanted Permanent Brachytherapy Seed Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, J; Cunha, J; Sudhyadhom, A; McGuinness, C; Roach, M; Descovich, M [University of California San Francisco, San Francisco, CA (United States)

    2016-06-15

    Purpose: Robotic radiosurgery is a salvage treatment option for patients with recurrent prostate cancer. We explored the feasibility of tracking the bolus of permanent prostate implants (PPI) using image recognition software optimized to track spinal anatomy. Methods: Forty-five inert iodine seeds were implanted into a gelatin-based prostate phantom. Four superficial gold seeds were inserted to provide ground-truth alignment. A CT scan of the phantom (120 kVp, 1 mm slice thickness) was acquired and a single-energy iterative metal artifact reduction (MAR) algorithm was used to enhance the quality of the DRR used for tracking. CyberKnife treatment plans were generated from the MAR CT and regular CT (no-MAR) using spine tracking. The spine-tracking grid was centered on the bolus of seeds and resized to encompass the full seed cloud. A third plan was created from the regular CT scan, using fiducial tracking based on the 4 superficial gold seeds with identical align-center coordinates. The phantom was initially aligned using the fiducial-tracking plan. Then the MAR and no-MAR spine-tracking plans were loaded without moving the phantom. Differences in couch correction parameters were recorded in the case of perfect alignment and after the application of known rotations and translations (roll/pitch of 2 degrees; translations XYZ of 2 cm). Results: The spine tracking software was able to lock on to the bolus of seeds and provide couch corrections both in the MAR and no-MAR plans. In all cases, differences in the couch correction parameters from fiducial alignment were <0.5 mm in translations and <1 degree in rotations. Conclusion: We were able to successfully track the bolus of seeds with the spine-tracking grid in phantom experiments. For clinical applications, further investigation and developments to adapt the spine-tracking algorithm to optimize for PPI seed cloud tracking is needed to provide reliable tracking in patients. One of the authors (MD) has received research

  3. Implant rehabilitation of partial maxillectomy edentulous patien

    Directory of Open Access Journals (Sweden)

    Mahesh E Gowda

    2013-01-01

    Full Text Available Edentulous patients with maxillectomy defects present a significant challenge for prosthetic rehabilitation and the adaptive capabilities of the patient as retention is highly compromised. Hence, the option of using endosseous implants to increase obturator retention has been used. A patient of mucormycosis of the left maxilla was treated with surgical excision. After satisfactory healing, definitive implant supported magnet retained prosthesis was fabricated for the patient. Implants with magnetic units offer a practical method of improving the retention of obturators provided acceptable prosthetic protocols are followed for the rehabilitation.

  4. Implant rehabilitation of partial maxillectomy edentulous patient

    Science.gov (United States)

    Gowda, Mahesh E.; Mohan, Murali S.; Verma, Kamal; Roy, I. D.

    2013-01-01

    Edentulous patients with maxillectomy defects present a significant challenge for prosthetic rehabilitation and the adaptive capabilities of the patient as retention is highly compromised. Hence, the option of using endosseous implants to increase obturator retention has been used. A patient of mucormycosis of the left maxilla was treated with surgical excision. After satisfactory healing, definitive implant supported magnet retained prosthesis was fabricated for the patient. Implants with magnetic units offer a practical method of improving the retention of obturators provided acceptable prosthetic protocols are followed for the rehabilitation. PMID:24124314

  5. Iodine-125 seeds for cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  6. Evaluation of implanted gold seeds for breast radiotherapy planning and on treatment verification: A feasibility study on behalf of the IMPORT trialists

    International Nuclear Information System (INIS)

    Coles, Charlotte E.; Harris, Emma J.; Donovan, Ellen M.; Bliss, Peter; Evans, Philip M.; Fairfoul, Jamie; Mackenzie, Christine; Rawlings, Christine; Syndikus, Isabel; Twyman, Nicola; Vasconcelos, Joana; Vowler, Sarah L.; Wilkinson, Jenny S.; Wilks, Robin; Wishart, Gordon C.; Yarnold, John

    2011-01-01

    Background and purpose: We describe a feasibility study testing the use of gold seeds for the identification of post-operative tumour bed after breast conservation surgery (BCS). Materials and Methods: Fifty-three patients undergoing BCS for invasive cancer were recruited. Successful use was defined as all six seeds correctly positioned around the tumour bed during BCS, unique identification of all implanted seeds on CT planning scan and ≥3 seeds uniquely identified at verification to give couch displacement co-ordinates in 10/15 fractions. Planning target volume (PTV) margin size for four correction strategies were calculated from these data. Variability in tumour bed contouring was investigated with five radiation oncologists outlining five CT datasets. Results: Success in inserting gold seeds, identifying them at CT planning and using them for on-treatment verification was recorded in 45/51 (88%), 37/38 (97%) and 42/43 (98%) of patients, respectively. The clinicians unfamiliar with CT breast planning consistently contoured larger volumes than those already trained. Margin size ranged from 10.1 to 1.4 mm depending on correction strategy. Conclusion: It is feasible to implant tumour bed gold seeds during BCS. Whilst taking longer to insert than surgical clips, they have the advantage of visibility for outlining and verification regardless of the ionising radiation beam quality. Appropriate correction strategies enable margins of the order of 5 mm as required by the IMPORT trials however, tackling clinician variability in contouring is important.

  7. Complementary method of analyzing the quality of the implant I-125 seeds for prostate brachytherapy using ultrasound imaging post-implant

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Sugawara, Akitomo; Shigematsu, Naoyuki; Nakashima, Jun; Kunieda, Etsuo; Nagata, Hirohiko; Mizuno, Ryuichi; Seki, Satoshi; Shiraishi, Yutaka; Kouta, Ryuichi; Oya, Mototsugu

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Beydoun, Nadine; Bucci, Joseph A.; Chin, Yaw S.; Malouf, David

    2014-01-01

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

  10. A dynamic model for the estimation of optimum timing of computed tomography scan for dose evaluation of 125I or 103Pd seed implant of prostate

    International Nuclear Information System (INIS)

    Yue Ning; Dicker, Adam P.; Corn, Benjamin W.; Nath, Ravinder; Waterman, Frank M.

    1999-01-01

    Purpose/Objective: The dosimetric evaluation of permanent 125 I or 103 Pd prostate implant is based on the assumption that both prostate and seeds are static throughout the entire treatment time which lasts months. However, the prostate is often edematous after the surgical implantation of seeds. Therefore, both the volume of the prostate and the seed locations change dynamically as the edema resolves. This effect has impact on the validity of postimplant analysis based upon a CT scan. If a CT scan is taken too early after implantation while there is edema in the prostate, the dose delivered by the implant may be underestimated. If the imaging is delayed too long, the dose may be overestimated. The magnitude of this effect depends on both of the half-life of the isotope used and the half-life and magnitude of the edema. This study describes a dynamic biomathematical model which takes edema into account in calculating the dose delivered by the implant and is used to investigate the optimum time to obtain the postimplant CT scan. Materials and Methods: The dynamic biomathematical model is a numerical integration of the accumulated dose in which the prostate dimensions, the seed locations, and the source strength are all functions of time. The function which describes the change in prostate dimensions and seed locations as a function of time was determined in a separate study by analysis of serial postimplant CT scans. Dose-volume histograms (DVH) of the prostate for the total dose generated by the dynamic model are compared to DVHs generated by CT scans simulated for postimplant intervals ranging from 0 to 300 days after the implantation for 30 different combinations of the magnitude and duration of edema. Results: DVHs of the prostate calculated by taking edema into account show that the time of obtaining a CT scan for postimplant analysis is critical to the accuracy of dose evaluations. The comparison of the DVHs generated by the dynamic model to those generated by

  11. Deuterium retention in molten salt electrodeposition tungsten coatings

    International Nuclear Information System (INIS)

    Zhou, Hai-Shan; Xu, Yu-Ping; Sun, Ning-Bo; Zhang, Ying-Chun; Oya, Yasuhisa; Zhao, Ming-Zhong; Mao, Hong-Min; Ding, Fang; Liu, Feng; Luo, Guang-Nan

    2016-01-01

    Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

  12. Deuterium retention in molten salt electrodeposition tungsten coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hai-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xu, Yu-Ping [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Sun, Ning-Bo; Zhang, Ying-Chun [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Mao, Hong-Min [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Ding, Fang; Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of Chinese Academy of Science, Hefei (China)

    2016-12-15

    Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

  13. Assessment of microseeds biodegradability of Sm and Sm:Ba splenic implants in rabbits

    International Nuclear Information System (INIS)

    Siqueira, Savio Lana; Barroso, Thiago Vinicius Villar; Campos, Tarcisio P.R.

    2009-01-01

    The radioactive interstitial implants have applications in controlling neoplasm in several regions of the human body. Currently the permanent brachytherapy seeds implanted in the spleen and other organs are made of I-125 seeds. After the total emission of radiation, the metal encapsulated seed remains inert in the implanted area. Seeds of bioactive ceramics have been prepared with Sm-152 incorporation to be activated in Sm-153. This study aimed to develop surgical technique for implanting biodegradable micro-seeds in the spleen of the rabbit. Three micro-seeds were introduced by hypodermic needle in the spleen in eight rabbits by median laparotomy. Subsequently, there were clinical and functional reactions of the animal to the implanted foreign body. The other objective was to perform the animal monitoring by radiography, produced in time sequence, and pathological studies of a fragment of the spleens of rabbits. The results show the effectiveness of surgery, the identification of the implanted material by radiography in vivo, and the biocompatibility of micro-seeds most of Sm and Sm:Ba. These seeds of reduced volume, 0.3x 1.6 mm, could be monitored for radiological studies in 2 periods: early and later implant. On the later studies, radiography was taken at 60d post-implant. Biopsies were taken and radiographs of the samples were also performed for evidencing the degradation state of the seeds. The results of the two groups of four rabbits are presented. They show partial degradation of the seed verified by radiographic contrast which is related to the atomic number of the elements and mass density in the seed. The biopsy showed that the ceramic is clearly absorbed by the spleen tissue and form tissue-implant interface. The histological slides showed an inflammatory reaction with presence of fibrosis of the giant cell foreign body. In conclusion, the radiograph shows a suitable noninvasive technique for monitoring the degradation of micro-seed ceramics in vivo

  14. Assessment of microseeds biodegradability of Sm and Sm:Ba splenic implants in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Savio Lana; Barroso, Thiago Vinicius Villar [Faculdade de Ciencias Medicas de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Anatomia; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Ciencias e Tecnicas Nucleares

    2009-07-01

    The radioactive interstitial implants have applications in controlling neoplasm in several regions of the human body. Currently the permanent brachytherapy seeds implanted in the spleen and other organs are made of I-125 seeds. After the total emission of radiation, the metal encapsulated seed remains inert in the implanted area. Seeds of bioactive ceramics have been prepared with Sm-152 incorporation to be activated in Sm-153. This study aimed to develop surgical technique for implanting biodegradable micro-seeds in the spleen of the rabbit. Three micro-seeds were introduced by hypodermic needle in the spleen in eight rabbits by median laparotomy. Subsequently, there were clinical and functional reactions of the animal to the implanted foreign body. The other objective was to perform the animal monitoring by radiography, produced in time sequence, and pathological studies of a fragment of the spleens of rabbits. The results show the effectiveness of surgery, the identification of the implanted material by radiography in vivo, and the biocompatibility of micro-seeds most of Sm and Sm:Ba. These seeds of reduced volume, 0.3x 1.6 mm, could be monitored for radiological studies in 2 periods: early and later implant. On the later studies, radiography was taken at 60d post-implant. Biopsies were taken and radiographs of the samples were also performed for evidencing the degradation state of the seeds. The results of the two groups of four rabbits are presented. They show partial degradation of the seed verified by radiographic contrast which is related to the atomic number of the elements and mass density in the seed. The biopsy showed that the ceramic is clearly absorbed by the spleen tissue and form tissue-implant interface. The histological slides showed an inflammatory reaction with presence of fibrosis of the giant cell foreign body. In conclusion, the radiograph shows a suitable noninvasive technique for monitoring the degradation of micro-seed ceramics in vivo

  15. 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.

  16. Implant-based overdenture: A review in patient perspective

    Directory of Open Access Journals (Sweden)

    R Krishnaraj

    2016-01-01

    Full Text Available A review in affected person's attitude in abstract care of edentulous patients has to be a priority in elderly individuals. The development of complete dentures (CDs has been the selection of remedy retaining in mind the socioeconomic popularity, age, and nutritional elements. However, most of the patients complain of loss of retention in mandibular implant-supported overdentures (ODs, which compensated the downside of the loss of retention in complete dentures (CDs. Moreover, implant supported over dentures (ISOVDs supplied accurate exceptional of lifestyles, esthetics, progressed nutritional deficiencies, and provided good patient satisfaction. The place of dental implants and desire of retentive attachments for implant supported mandibular over dentures (ISOVD are selected on clinician preference and professional opinion. This text offers a fundamental statistics regarding implant placement, mode of treatment to be selected, and patient care. Two implants provide extraordinary long-term achievement and survival with improved oral capabilities. Single midline implant OD is costly, powerful, and may be a promising alternative. In maxilla, 4–6 implants splinted with bar have located to give true results.

  17. Influence of breast composition and interseed attenuation in dose calculations for post-implant assessment of permanent breast 103Pd seed implant

    International Nuclear Information System (INIS)

    Afsharpour, Hossein; Beaulieu, Luc; Pignol, Jean-Philippe; Keller, Brian; Carrier, Jean-Francois; Reniers, Brigitte; Verhaegen, Frank

    2010-01-01

    The impact of tissue heterogeneity and interseed attenuation is studied in post-implant evaluation of five clinical permanent breast 103 Pd seed implants using the Monte Carlo (MC) dose calculation method. Dose metrics for the target (PTV) as well as an organ at risk (skin) are used to visualize the differences between a TG43-like MC method and more accurate MC methods capable of considering the breast tissue heterogeneity as well as the interseed attenuation. PTV dose is reduced when using a breast tissue model instead of water in MC calculations while the dose to the skin is increased. Furthermore, we investigate the effect of varying the glandular/adipose proportion of the breast tissue on dose distributions. The dose to the PTV (skin) decreases (increases) with the increasing adipose proportion inside the breast. In a complete geometry and compared to a TG43-like situation, the average PTV D 90 reduction varies from 3.9% in a glandular breast to 35.5% when the breast consists entirely of adipose. The skin D 10 increases by 28.2% in an entirely adipose breast. The results of this work show the importance of an accurate and patient-dependent breast tissue model to be used in the dosimetry for this kind of low energy implant.

  18. Gamma spectrometry and chemical characterization of bioactive glass seeds with Holmium-166 for oncological implants

    International Nuclear Information System (INIS)

    Valente, Eduardo S.

    2009-01-01

    Bioactive glass seeds synthesized by the sol-gel technique with Si:Ho:Ca composition with natural holmium incorporated were irradiated in the TRIGA type nuclear reactor IPR-R1 at 100kW, in the central thimble where the thermal neutron flux is 2.8x10 12 n/cm 2 .s and the epithermal neutron flux is 2.6 X 10 11 n/cm 2 .s . After an 8 hour irradiation time, with an induced activity close to 110MBq/seed, a set of seeds was submitted to Gamma Spectrometry Analysis in a counting system with an HPGe detector, ORTEC electronic instrumentation and a Camberra Multichannel Analyser, to determine all radionuclides present on the sample as well as its individual activities. Special attention was paid on the discrimination of Si, 40 Ca, 44 Ca, C and Ho as the other expected elements like 48 Ca, 2 H and 18 O were present in traces or have very short half-lives. The second sample was submitted to Plasma spectrometry to determine the 166 Ho concentration in weight. The third sample was submitted to an X-ray spectrometry in a JEOL-JXA-8900RL equipment to determine its qualitative chemical composition, in order to evaluate impurities and nominal composition. It was determined that most of the activity, after decaying of short half-life elements, was due to 166 Ho present on the sample, with a well characterized β and gamma spectra. The homogeneity of the seeds was tested on the X-ray spectrometry, and verified that there is no discrepancy in composition from distinct seeds or in a same seed. The results are relevant on the investigation of the viability of producing 166 Ho radioactive seeds for oncological implants. (author)

  19. Retention time variability as a mechanism for animal mediated long-distance dispersal.

    Directory of Open Access Journals (Sweden)

    Vishwesha Guttal

    Full Text Available Long-distance dispersal (LDD events, although rare for most plant species, can strongly influence population and community dynamics. Animals function as a key biotic vector of seeds and thus, a mechanistic and quantitative understanding of how individual animal behaviors scale to dispersal patterns at different spatial scales is a question of critical importance from both basic and applied perspectives. Using a diffusion-theory based analytical approach for a wide range of animal movement and seed transportation patterns, we show that the scale (a measure of local dispersal of the seed dispersal kernel increases with the organisms' rate of movement and mean seed retention time. We reveal that variations in seed retention time is a key determinant of various measures of LDD such as kurtosis (or shape of the kernel, thinkness of tails and the absolute number of seeds falling beyond a threshold distance. Using empirical data sets of frugivores, we illustrate the importance of variability in retention times for predicting the key disperser species that influence LDD. Our study makes testable predictions linking animal movement behaviors and gut retention times to dispersal patterns and, more generally, highlights the potential importance of animal behavioral variability for the LDD of seeds.

  20. Oxidative stability and alpha-tocopherol retention in soybean oil with lemon seed extract (Citrus limon) under thermoxidation.

    Science.gov (United States)

    Luzia, Débora Maria Moreno; Jorge, Neuza

    2009-11-01

    The synergistic effect of lemon seed extract with tert-butylhydroquinone (TBHQ) in soybean oil subjected to thermoxidation by Rancimat was investigated, and the influence of these antioxidants on a-tocopherol degradation in thermoxidized soybean oil. Control, LSE (2400 mg/kg Lemon Seed Extract), TBHQ (50 mg/kg), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were subjected to 180 degrees C for 20 h. Samples were taken at time 0, 5, 10, 15 and 20 h intervals and analysed for oxidative stability and alpha-tocopherol content. LSE and Mixtures 1 and 2 showed the capacity of retarding lipid oxidation when added to soya oil and also contributed to alpha-tocopherol retention in oil heated at high temperatures. However, Mixtures 1 and 2 added to the oil presented a greater antioxidant power, consequently proving the antioxidants synergistic effect.

  1. 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

  2. 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)

  3. First nitrogen-seeding experiments in JET with the ITER-like Wall

    Energy Technology Data Exchange (ETDEWEB)

    Oberkofler, M., E-mail: martin.oberkofler@ipp.mpg.de [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Douai, D. [CEA Centre de Cadarache, 13108 Saint Paul lez Durance, Cedex (France); Brezinsek, S.; Coenen, J.W. [Institut für Energie- und Klimaforschung, IEK-4, TEC, Association EURATOM-FZJ, 52425 Jülich (Germany); Dittmar, T. [Center for Energy Research, University of California–San Diego, 9500 Gilman Dr., San Diego, CA 92093-0417 (United States); Drenik, A. [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Romanelli, S.G. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Joffrin, E. [CEA Centre de Cadarache, 13108 Saint Paul lez Durance, Cedex (France); McCormick, K. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Brix, M. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Calabro, G. [Associazione EURATOM-ENEA sulla Fusione, Via E. Fermi 45 FRASCATI-Roma (Italy); Clever, M. [Institut für Energie- und Klimaforschung, IEK-4, TEC, Association EURATOM-FZJ, 52425 Jülich (Germany); Giroud, C. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kruezi, U. [Institut für Energie- und Klimaforschung, IEK-4, TEC, Association EURATOM-FZJ, 52425 Jülich (Germany); Lawson, K. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Linsmeier, Ch. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); and others

    2013-07-15

    In this contribution we present results from the first N{sub 2} seeding experiments in JET performed after installation of the ITER-like Wall. Gas balance measurements for seeded L-mode discharges indicate very strong N{sub 2} retention as well as a potential increase in D{sub 2} retention. The possible influence of ammonia production on this apparent retention is discussed. Plasma parameters and impurity content were monitored throughout the seeded discharges as well as during subsequent clean-up discharges. These experiments give first insight into phenomena related to the use of nitrogen as seeding gas in JET with the ITER-like Wall, such as ammonia production and nitrogen legacy.

  4. Moving toward focal therapy in prostate cancer: dual-isotope permanent seed implants as a possible solution.

    Science.gov (United States)

    Todor, Dorin A; Barani, Igor J; Lin, Peck-Sun; Anscher, Mitchell S

    2011-09-01

    To compare the ability of single- and dual-isotope prostate seed implants to escalate biologically effective dose (BED) to foci of disease while reducing prescription dose to the prostate. Nine plans, using 125I, 103Pd, and 131Cs alone and in combination were created retrospectively for 2 patients. Ultrasound and MRI/MRS datasets were used for treatment planning. Voxel-by-voxel BED was calculated for single- and dual-isotope plans. Equivalent uniform BED (EUBED) was used to compare plans. The MRS-positive planning target volumes (PTVi) were delineated along with PTV (prostate+5 mm), rectum, and urethra. Single-isotope implants, prescribed to conventional doses, were generated to achieve good PTV coverage. The PTVi were prospectively used to generate implants using mixtures of isotopes. For mixed-radioisotope implants, we also explored the impact on EUBED of lowering prescription doses by 15%. The EUBED of PTVi in the setting of primary 125I implant increased 20-66% when 103Pd and 131Cs were used compared with 125I boost. Decreasing prescription dose by 15% in mixed-isotope implants results in a potential 10% reduction in urethral EUBED with preservation of PTV coverage while still boosting PTVi (up to 80%). When radiobiologic parameters corresponding to more-aggressive disease are assigned to foci, faster-decaying isotopes used in mixed implants have the potential to preserve the equivalent biological effect of mono-isotope implants considering less-aggressive disease distributed in the entire prostate. This is a hypothesis-generating study proposing a treatment paradigm that could be the middle ground between whole-gland irradiation and focal-only treatment. The use of two isotopes concurrent with decreasing the minimal peripheral dose is shown to increase EUBED of selected subvolumes while preserving the therapeutic effect at the level of the gland. Copyright © 2011 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Kalolo, L.T.

    2013-06-01

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

  6. Intraoperative dynamic dosimetry for prostate implants

    Energy Technology Data Exchange (ETDEWEB)

    Todor, D A [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Zaider, M [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Cohen, G N [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Worman, M F [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States); Zelefsky, M J [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (United States)

    2003-05-07

    This paper describes analytic tools in support of a paradigm shift in brachytherapy treatment planning for prostate cancer - a shift from standard pre-planning to intraoperative planning using dosimetric feedback based on the actual deposited seed positions within the prostate. The method proposed is guided by several desiderata: (a) bringing both planning and evaluation in the operating room (i.e. make post-implant evaluation superfluous) therefore making rectifications - if necessary - still achievable; (b) making planning and implant evaluation consistent by using the same imaging system (ultrasound); and (c) using only equipment commonly found in a hospital operating room. The intraoperative dosimetric evaluation is based on the fusion between ultrasound images and 3D seed coordinates reconstructed from fluoroscopic projections. Automatic seed detection and registration of the fluoroscopic and ultrasound information, two of the three key ingredients needed for the intraoperative dynamic dosimetry optimization (IDDO), are explained in detail. The third one, the reconstruction of 3D coordinates from projections, was reported in a previous article. The algorithms were validated using a custom-designed phantom with non-radioactive (dummy) seeds. Also, fluoroscopic images were taken at the conclusion of an actual permanent prostate implant and compared with data on the same patient obtained from radiographic-based post-implant evaluation. To offset the effect of organ motion the comparison was performed in terms of the proximity function of the two seed distributions. The agreement between the intra- and post-operative seed distributions was excellent.

  7. 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

  8. Dosimetric effectiveness in implants with distinct HO166-seed distribution in prostate

    International Nuclear Information System (INIS)

    Braga, Viviane V. B.; Campos, Tarcísio P. R.

    2017-01-01

    Currently, there is a need to produce new therapeutic techniques for the treatment of prostate tumors, considering the high incidence of the disease and significant morbidity rates associated with surgery and radiotherapy. Simulations in brachytherapy produce essential information about the efficiency and dosimetric efficacy compared to other techniques. Computational simulation by Monte Carlo method has been used to evaluate the absorbed dose and effective dose in radiotherapy and radiology. Virtual, analytical or voxelized phantoms are useful in the internal assessment of the spatial distribution of absorbed dose. This study estimated the efficiency of dosimetry by parameters of merit generated from volumetric distributions of absorbed doses simulating various spatial distributions of Ho-166 seeds in a prostate model. A computer model of voxels was developed, using the code SISCODES (Computational System for Dosimetry by Neutrons and Photons by Stochastic Methods applied to radiology and radiotherapy), representative of a real physical simulator predefined as a calibration method. The virtual model reproduced a cubic box, filled with muscle equivalent tissue (TE), where a 5-cm diameter ball with TE-prostate was positioned 2-cm from the air interface. A Ho-166 seed distribution, produced by 16 filet-implants distributed regularly (10-mm pitch) containing 04 separate 8-mm seeds, was employed. Two pitch were considered: 9 and 10 mm, with same distance between seed in a fillet. Based on SISCODE database of chemical composition of tissues and nuclear data, The code allowed the association of nuclear and chemical data to the voxels of the model, by the selection of the tissue of each voxel, as well as the positioning of the sources and their spatial distribution and spectra. The code MCNP5 simulated the transport of photons and electrons in the model, generating the energy deposited per unit mass in each voxel for photons in MeV.g-1 and energy absorbed in MeV for beta

  9. Dosimetric effectiveness in implants with distinct HO166-seed distribution in prostate

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Viviane V. B.; Campos, Tarcísio P. R., E-mail: Vitoriabraga06@gmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    Currently, there is a need to produce new therapeutic techniques for the treatment of prostate tumors, considering the high incidence of the disease and significant morbidity rates associated with surgery and radiotherapy. Simulations in brachytherapy produce essential information about the efficiency and dosimetric efficacy compared to other techniques. Computational simulation by Monte Carlo method has been used to evaluate the absorbed dose and effective dose in radiotherapy and radiology. Virtual, analytical or voxelized phantoms are useful in the internal assessment of the spatial distribution of absorbed dose. This study estimated the efficiency of dosimetry by parameters of merit generated from volumetric distributions of absorbed doses simulating various spatial distributions of Ho-166 seeds in a prostate model. A computer model of voxels was developed, using the code SISCODES (Computational System for Dosimetry by Neutrons and Photons by Stochastic Methods applied to radiology and radiotherapy), representative of a real physical simulator predefined as a calibration method. The virtual model reproduced a cubic box, filled with muscle equivalent tissue (TE), where a 5-cm diameter ball with TE-prostate was positioned 2-cm from the air interface. A Ho-166 seed distribution, produced by 16 filet-implants distributed regularly (10-mm pitch) containing 04 separate 8-mm seeds, was employed. Two pitch were considered: 9 and 10 mm, with same distance between seed in a fillet. Based on SISCODE database of chemical composition of tissues and nuclear data, The code allowed the association of nuclear and chemical data to the voxels of the model, by the selection of the tissue of each voxel, as well as the positioning of the sources and their spatial distribution and spectra. The code MCNP5 simulated the transport of photons and electrons in the model, generating the energy deposited per unit mass in each voxel for photons in MeV.g-1 and energy absorbed in MeV for beta

  10. A Radiation Badge Survey for Family Members Living With Patients Treated With a 103Pd Permanent Breast Seed Implant

    International Nuclear Information System (INIS)

    Keller, Brian M.; Pignol, Jean-Philippe; Rakovitch, Eileen; Sankreacha, Raxa; O'Brien, Peter

    2008-01-01

    Purpose: Sixty-seven patients with early-stage breast cancer were treated in a Phase I/II clinical trial using a 103 Pd permanent breast seed implant as adjuvant radiotherapy after breast-conserving surgery. We report the dose received by family members living with these patients and compare measured doses with theoretical worst-case scenario estimates. Methods and Materials: Exposure-rate measurements were taken at 1 m from the patient by using a calibrated low-energy survey meter. Landauer (Landauer Inc., Glenwood, IL) Luxel badges, with sensitivity of 0.01 mSv, were given to family members to wear after the implantation. Badge readings for 33 spouses and 28 other family members were used to estimate effective doses, and these were compared with theory. Results: Average preimplantation planning target volume from computed tomography was 50.3 ml (range, 18.0-96.7 ml), and average preimplantation distance between the skin and the most anterior planning target volume margin was 0.57 cm. The average maximum exposure rate was measured to be 2.4 ± 1.1 mR/h, and average measured dose to a spouse was 0.99 ± 1.0 mSv. The calculated exposure rates and spousal doses using preimplantation computed tomography scan data overestimated those measured. Average measured family member dose (excluding spouses) was 0.20 ± 0.58 mSv. Conclusions: Based on measured and calculated spousal doses, a permanent breast seed implant using 103 Pd is safe for the public. However, it is recommended that extra precautions in the way of a breast patch be used when patients with an implant will be in the vicinity of toddlers or pregnant women

  11. Effects of abutment diameter, luting agent type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments.

    Science.gov (United States)

    Safari, Sina; Hosseini Ghavam, Fereshteh; Amini, Parviz; Yaghmaei, Kaveh

    2018-02-01

    The aim of this study was to evaluate the effects of abutment diameter, cement type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments. Sixty abutments with two different diameters, the height of which was reduced to 3 mm, were vertically mounted in acrylic resin blocks with matching implant analogues. The specimens were divided into 2 diameter groups: 4.5 mm and 5.5 mm (n=30). For each abutment a CAD/CAM metal coping was manufactured, with an occlusal loop. Each group was sub-divided into 3 sub-groups (n=10). In each subgroup, a different cement type was used: resin-modified glass-ionomer, resin cement and zinc-oxide-eugenol. After incubation and thermocycling, the removal force was measured using a universal testing machine at a cross-head speed of 0.5 mm/min. In zinc-oxide-eugenol group, after removal of the coping, the cement remnants were completely cleaned and the copings were re-cemented with resin cement and re-tested. Two-way ANOVA, post hoc Tukey tests, and paired t-test were used to analyze data (α=.05). The highest pulling force was registered in the resin cement group (414.8 N), followed by the re-cementation group (380.5 N). Increasing the diameter improved the retention significantly ( P =.006). The difference in retention between the cemented and recemented copings was not statistically significant ( P =.40). Resin cement provided retention almost twice as strong as that of the RMGI. Increasing the abutment diameter improved retention significantly. Re-cementation with resin cement did not exhibit any difference from the initial cementation with resin cement.

  12. Ultrasonically guided 125iodine seed implantation with external radiation in management of localized prostatic carcinoma

    DEFF Research Database (Denmark)

    Iversen, P; Bak, M; Juul, N

    1989-01-01

    Thirty-three patients with localized prostatic carcinoma (16 poorly differentiated) were treated with transperineal 125Iodine seed implantation (160 Gy) guided by transrectal ultrasonography and subsequent external beam irradiation (47.4 Gy). The observation time was six to sixty-eight months...... with a median follow-up of thirty-five months. Median change in prostatic volume was a reduction of 35 percent. Re-biopsy or transurethral resection of the prostate was performed in 25 patients after one to two years, revealing still malignant histology in 12 (48%). Development of distant metastases occurred...

  13. 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)

  14. 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

  15. Quality control of system of imaging for rectal ultrasound for implants seed prostate low rate; Control de calidad del sistem de imagen por ecografia rectal para implantes de semillas de prostata de baja tasa

    Energy Technology Data Exchange (ETDEWEB)

    Luquero Llopis, N.; Ferrer Gracia, C.; Huertas Martinez, C.; Huerga Cabrerizo, C.; Corredoira Silva, E.; Serrada Hierro, A.

    2013-07-01

    In this work, the objective is the evaluation of the image system used in implants of prostate of low rate held at our hospital, for maximum control on the placement of the seeds in the patient and therefore carried out dosimetry. (Author)

  16. 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

  17. Effects of abutment diameter, luting agent type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments

    Science.gov (United States)

    Safari, Sina; Amini, Parviz; Yaghmaei, Kaveh

    2018-01-01

    PURPOSE The aim of this study was to evaluate the effects of abutment diameter, cement type, and re-cementation on the retention of implant-supported CAD/CAM metal copings over short abutments. MATERIALS AND METHODS Sixty abutments with two different diameters, the height of which was reduced to 3 mm, were vertically mounted in acrylic resin blocks with matching implant analogues. The specimens were divided into 2 diameter groups: 4.5 mm and 5.5 mm (n=30). For each abutment a CAD/CAM metal coping was manufactured, with an occlusal loop. Each group was sub-divided into 3 sub-groups (n=10). In each subgroup, a different cement type was used: resin-modified glass-ionomer, resin cement and zinc-oxide-eugenol. After incubation and thermocycling, the removal force was measured using a universal testing machine at a cross-head speed of 0.5 mm/min. In zinc-oxide-eugenol group, after removal of the coping, the cement remnants were completely cleaned and the copings were re-cemented with resin cement and re-tested. Two-way ANOVA, post hoc Tukey tests, and paired t-test were used to analyze data (α=.05). RESULTS The highest pulling force was registered in the resin cement group (414.8 N), followed by the re-cementation group (380.5 N). Increasing the diameter improved the retention significantly (P=.006). The difference in retention between the cemented and recemented copings was not statistically significant (P=.40). CONCLUSION Resin cement provided retention almost twice as strong as that of the RMGI. Increasing the abutment diameter improved retention significantly. Re-cementation with resin cement did not exhibit any difference from the initial cementation with resin cement. PMID:29503708

  18. Role of hormonal therapy in the management of intermediate- to high-risk prostate cancer treated with permanent radioactive seed implantation

    International Nuclear Information System (INIS)

    Lee, Lucille N.; Stock, Richard G.; Stone, Nelson N.

    2002-01-01

    Purpose: To study the impact of hormonal therapy (HTx) on intermediate- to high-risk prostate cancer treated with permanent radioactive seed implantation. Methods and Materials: Patients with Stage T1b-T3bN0 prostate cancer, and Gleason score ≥7 or prostate-specific antigen (PSA) level >10 ng/mL were treated with seed implantation with or without HTx. Their disease was defined as intermediate risk (PSA 10-20, Gleason score 7, or Stage T2b) or high risk (two or more intermediate criteria, or PSA >20 ng/mL, Gleason score 8-10, or Stage T2c-T3). The median follow-up for 201 eligible patients was 42 months (range 18-110). Biochemical failure was defined as a rising PSA >1.0 ng/mL. Pretreatment disease characteristics, implant dose, and HTx were evaluated using univariate and multivariate analyses. Results: HTx significantly improved 5-year actuarial freedom from biochemical failure rate, 79% vs. 54% without HTx. In addition, high-dose, PSA ≤15 ng/mL, intermediate risk, and Stage T2a or lower significantly improved outcome in the univariate analyses. HTx was the most significant predictor of 5-year actuarial freedom from biochemical failure (p <0.0001) in a multivariate analysis. The best outcome was in the intermediate-risk patients treated with a high implant dose and HTx, resulting in a 4-year actuarial freedom from biochemical failure rate of 94%. Conclusion: In this retrospective review, HTx improved outcome in intermediate- to high-risk prostate cancer patients treated with brachytherapy. HTx was the most important prognostic factor in the univariate and multivariate analyses

  19. Gene expression profiling of the green seed problem in Soybean.

    Science.gov (United States)

    Teixeira, Renake N; Ligterink, Wilco; França-Neto, José de B; Hilhorst, Henk W M; da Silva, Edvaldo A A

    2016-02-01

    Due to the climate change of the past few decades, some agricultural areas in the world are now experiencing new climatic extremes. For soybean, high temperatures and drought stress can potentially lead to the "green seed problem", which is characterized by chlorophyll retention in mature seeds and is associated with lower oil and seed quality, thus negatively impacting the production of soybean seeds. Here we show that heat and drought stress result in a "mild" stay-green phenotype and impaired expression of the STAY-GREEN 1 and STAY-GREEN 2 (D1, D2), PHEOPHORBIDASE 2 (PPH2) and NON-YELLOW COLORING 1 (NYC1_1) genes in soybean seeds of a susceptible soybean cultivar. We suggest that the higher expression of these genes in fully mature seeds of a tolerant cultivar allows these seeds to cope with stressful conditions and complete chlorophyll degradation. The gene expression results obtained in this study represent a significant advance in understanding chlorophyll retention in mature soybean seeds produced under stressful conditions. This will open new research possibilities towards finding molecular markers for breeding programs to produce cultivars which are less susceptible to chlorophyll retention under the hot and dry climate conditions which are increasingly common in the largest soybean production areas of the world.

  20. Clinical implementation of stereotaxic brain implant optimization

    International Nuclear Information System (INIS)

    Rosenow, U.F.; Wojcicka, J.B.

    1991-01-01

    This optimization method for stereotaxic brain implants is based on seed/strand configurations of the basic type developed for the National Cancer Institute (NCI) atlas of regular brain implants. Irregular target volume shapes are determined from delineation in a stack of contrast enhanced computed tomography scans. The neurosurgeon may then select up to ten directions, or entry points, of surgical approach of which the program finds the optimal one under the criterion of smallest target volume diameter. Target volume cross sections are then reconstructed in 5-mm-spaced planes perpendicular to the implantation direction defined by the entry point and the target volume center. This information is used to define a closed line in an implant cross section along which peripheral seed strands are positioned and which has now an irregular shape. Optimization points are defined opposite peripheral seeds on the target volume surface to which the treatment dose rate is prescribed. Three different optimization algorithms are available: linear least-squares programming, quadratic programming with constraints, and a simplex method. The optimization routine is implemented into a commercial treatment planning system. It generates coordinate and source strength information of the optimized seed configurations for further dose rate distribution calculation with the treatment planning system, and also the coordinate settings for the stereotaxic Brown-Roberts-Wells (BRW) implantation device

  1. Neutral particle retention in the JET MK I divertor

    International Nuclear Information System (INIS)

    Ehrenberg, J.K.; Campbell, D.J.; Harbour, P.J.; Horton, L.D.; Loarte, A.; McCormick, G.K.; Monk, R.D.; Saibene, G.R.; Simonini, R.; Taroni, A.; Stamp, M.F.

    1997-01-01

    Retention of neutral deuterium and nitrogen in the JET MK I divertor has been investigated. Results show that ohmic plasma detachment reduces deuterium retention, that the magnetic divertor configuration has some influence on the achievable deuterium retention, and that nitrogen in nitrogen-seeded steady state detached H-mode discharges accumulates in the divertor. (orig.)

  2. Ecological correlates of seed survival after ingestion by Fallow Deer

    NARCIS (Netherlands)

    Mouissie, AM; Van der Veen, CEJ; Veen, GF; Van Diggelen, R

    1. The survival and retention of seeds was studied by feeding known quantities of seeds of 25 species to four captive Fallow Deer (Dama dama L.). To test for ecological correlates, plant species were selected to represent large variation in seed size, seed shape, seed longevity and habitat

  3. SU-E-J-166: Sensitivity of Clinically Relevant Dosimetric Parameters to Contouring Uncertainty During Post Implant Dosimetry of Prostate Permanent Seed Implants

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S [Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Ravi, A; Morton, G; Song, W [Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Sunnybrook Research Institute, Toronto, ON (Canada)

    2015-06-15

    Purpose: There is a strong evidence relating post-implant dosimetry for permanent seed prostate brachytherpy to local control rates. The delineation of the prostate on CT images, however, represents a challenge as it is difficult to confidently identify the prostate borders from soft tissue surrounding it. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to prostate contouring uncertainty. Methods: The post-implant CT images and plans for a cohort of 43 patients, who have received I–125 permanent prostate seed implant in our centre, were exported to MIM Symphony LDR brachytherapy treatment planning system (MIM Software Inc., Cleveland, OH). The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00mm, ±2.00mm, ±3.00mm, ±4.00mm and ±5.00mm (±0.01mm). The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: The mean value of V100 and D90 was obtained as 92.3±8.4% and 108.4±12.3% respectively (Rx=145Gy). V100 was reduced by −3.2±1.5%, −7.2±3.0%, −12.8±4.0%, −19.0±4.8%, − 25.5±5.4% for expanded contours of prostate with margins of +1mm, +2mm, +3mm, +4mm, and +5mm, respectively, while it was increased by 1.6±1.2%, 2.4±2.4%, 2.7±3.2%, 2.9±4.2%, 2.9±5.1% for the contracted contours. D90 was reduced by −6.9±3.5%, −14.5±6.1%, −23.8±7.1%, − 33.6±8.5%, −40.6±8.7% and increased by 4.1±2.6%, 6.1±5.0%, 7.2±5.7%, 8.1±7.3% and 8.1±7.3% for the same set of contours. Conclusion: Systematic expansion errors of more than 1mm may likely render a plan sub-optimal. Conversely contraction errors may Result in labeling a plan likely as optimal. The use of MRI images to contour the prostate should results in better delineation of prostate organ which increases the predictive value of post-op plans. Since observers tend to overestimate the prostate volume on CT, compared with MRI, the impact of the

  4. Lateral approach for maxillary sinus membrane elevation without bone materials in maxillary mucous retention cyst with immediate or delayed implant rehabilitation: case reports.

    Science.gov (United States)

    Han, Ji-Deuk; Cho, Seong-Ho; Jang, Kuk-Won; Kim, Seong-Gwang; Kim, Jung-Han; Kim, Bok-Joo; Kim, Chul-Hun

    2017-08-01

    This case series study demonstrates the possibility of successful implant rehabilitation without bone augmentation in the atrophic posterior maxilla with cystic lesion in the sinus. Sinus lift without bone graft using the lateral approach was performed. In one patient, the cyst was aspirated and simultaneous implantation under local anesthesia was performed, whereas the other cyst was removed under general anesthesia, and the sinus membrane was elevated in a second process, followed by implantation. In both cases, tapered 11.5-mm-long implants were utilized. With all of the implants, good stability and appropriate bone height were achieved. The mean bone level gain was 5.73 mm; adequate bone augmentation around the implants was shown, the sinus floor was moved apically, and the cyst was no longer radiologically detected. Completion of all of the treatments required an average of 12.5 months. The present study showed that sufficient bone formation and stable implantation in a maxilla of insufficient bone volume are possible through sinus lift without bone materials. The results serve to demonstrate, moreover, that surgical treatment of mucous retention cyst can facilitate rehabilitation. These techniques can reduce the risk of complications related to bone grafts, save money, and successfully treat antral cyst.

  5. 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

  6. Sacral root neuromodulation in idiopathic nonobstructive chronic urinary retention.

    Science.gov (United States)

    Shaker, H S; Hassouna, M

    1998-05-01

    Sacral root neuromodulation is becoming a superior alternative to the standard treatment of idiopathic nonobstructive urinary retention. We report results in 20 successive patients who underwent sacral foramen implantation to restore bladder function. After an initial, thorough baseline assessment 20 patients 19.43 to 55.66 years old with idiopathic nonobstructive urinary retention underwent percutaneous nerve evaluation. Response was assessed by a detailed voiding diary. Responders underwent implantation with an S3 foramen implant, and were followed 1, 3 and 6 months postoperatively, and every 6 months thereafter. Sacral root neuromodulation restored voiding capability in these patients. Bladders were emptied with minimal post-void residual urine, which decreased from 78.3 to 5.5 to 10.2% of the total voided volume from baseline to postoperative followup. These results were reflected in uroflowmetry and pressure-flow studies, which were almost normal after implantation. Furthermore, the urinary tract infection rate decreased significantly and associated pelvic pain improved substantially. The Beck depression inventory and SF-36 quality of life questionnaire indicated some improvement but reached significance in only 1 item. In addition, cystometrography showed no significant difference after 6 months of implantation compared with baseline values. Complications were minimal and within expectations. Sacral root neuromodulation is an appealing, successful modality for nonobstructive urinary retention. Only patients who have a good response to percutaneous nerve evaluation are candidates for implantation. The high efficacy in patients who undergo implantation, relative simplicity of the procedure and low complication rate make this a treatment breakthrough in this difficult group.

  7. Implant-retained maxillary overdentures.

    Science.gov (United States)

    Eckert, Steven E; Carr, Alan B

    2004-07-01

    Overdentures supported by osseointegrated implants overcome many of the complications observed with overdentures supported by natural teeth. Dental implants are free of biologic consequences associated with natural teeth, such as dental caries and periodontal disease. Bone undercuts adjacent to implants do not mimic those found adjacent to natural tooth roots. Implants are used to provide predictable retention, support, and stability for overdenture prostheses. When lip or facial support is required, the overdenture is the treatment of choice. Likewise the overdenture may improve phonetic deficiencies associated with alveolar bone loss.

  8. Clinical evaluation of sinus bone graft in patients with mucous retention cyst.

    Science.gov (United States)

    Kim, Seong-Beom; Yun, Pil-Young; Kim, Young-Kyun

    2016-12-01

    Mucous retention cyst refers to a cyst made by expansion due to the blockage of the salivary gland near the maxillary sinus, and it is surrounded by epithelial cells. Most of them are small; therefore, they cannot be found well and are frequently with antral polyp. The aim of this study was to evaluate the clinical prognosis of sinus bone graft in patients with mucous retention cyst. This study was performed retrospectively on 23 patients who had sinus bone graft. Group 1 was 8 patients (10 sinuses) who had a mucous retention cyst, and group 2 was 15 patients (17 sinuses) who had no pathologic history about the maxillary sinus. For these patients, sinus bone graft was performed using the lateral approach technique. The total 51 implants were placed 6.22 weeks on the average after sinus bone graft. Sinus membrane perforation during operation, postoperative complications, marginal bone loss after restorative function, implant success rate, and survival rate were analyzed. There was no complication in group 1, and there were three complications in group 2. In group 2, two cases of implants failed. The types of postoperative complications consisted of two minor infections and one wound dehiscence. Two implants of total 51 implants were removed, and the survival rate of implants was 96.08 % (group 1 100 %, group 2 93.5 %). The total success rate of implants was 92.2 % (group 1 95 %, group 2 90.3 %). The clinical prognosis was not affected by the presence of mucous retention cyst.

  9. Report on the Clinical Outcomes of Permanent Breast Seed Implant for Early-Stage Breast Cancers

    International Nuclear Information System (INIS)

    Pignol, Jean-Philippe; Caudrelier, Jean-Michel; Crook, Juanita; McCann, Claire; Truong, Pauline; Verkooijen, Helena A.

    2015-01-01

    Purpose: Permanent breast seed implant is an accelerated partial breast irradiation technique realizing the insertion of "1"0"3Pd seeds in the seroma after lumpectomy. We report the 5-year efficacy and tolerance for a cohort, pooling patients from 3 clinical trials. Methods and Materials: The trials accrued postmenopausal patients with infiltrating ductal carcinoma or ductal carcinoma in situ ≤3 cm and clear surgical margins, who were node negative, and had a planning target volume <120 cm"3. The outcomes included overall and disease-free survival and local and contralateral recurrence at 5 years. The true local recurrence rate was compared using 2-tailed paired t tests for estimates calculated using the Tufts University ipsilateral breast tumor recurrence and Memorial Sloan Kettering ductal carcinoma in situ nomograms. Results: The cohort included 134 patients, and the observed local recurrence rate at a median follow-up period of 63 months was 1.2% ± 1.2%, similar to the estimate for whole breast irradiation (P=.23), significantly better than for surgery alone (relative risk 0.27; P<.001), and significantly lower than contralateral recurrence (relative risk 0.33; P<.001). The 5-year overall survival rate was 97.4% ± 1.9%, and the disease-free survival rate was 96.4% ± 2.1%. At 2 months, 42% of the patients had erythema, 20% induration, and 16% moist desquamation. The rate of mainly grade 1 telangiectasia was 22.4% at 2 years and 24% at 5 years. The rate of asymptomatic induration was 23% at 2 years and 40% at 5 years. Conclusions: The 5-year data suggest that permanent breast seed implantation is a safe accelerated partial breast irradiation option after lumpectomy for early-stage breast cancer with a tolerance profile similar to that of whole breast irradiation.

  10. Report on the Clinical Outcomes of Permanent Breast Seed Implant for Early-Stage Breast Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Pignol, Jean-Philippe, E-mail: j.p.pignol@erasmusmc.nl [Radiation Oncology Department, University of Toronto at Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Radiation Oncology Department, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Caudrelier, Jean-Michel [Department of Radiation Medicine, The Ottawa Hospital Cancer Centre, Ottawa, Ontario (Canada); Crook, Juanita [Department of Radiation Oncology, BC Cancer Agency Center for the Southern Interior, Kelowna, British Columbia (Canada); McCann, Claire [Radiation Oncology Department, University of Toronto at Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Truong, Pauline [Radiation Oncology Department, BC Cancer Agency Vancouver Island Centre, Victoria, British Columbia (Canada); Verkooijen, Helena A. [Imaging Division, University Medical Centre Utrecht, Utrecht (Netherlands)

    2015-11-01

    Purpose: Permanent breast seed implant is an accelerated partial breast irradiation technique realizing the insertion of {sup 103}Pd seeds in the seroma after lumpectomy. We report the 5-year efficacy and tolerance for a cohort, pooling patients from 3 clinical trials. Methods and Materials: The trials accrued postmenopausal patients with infiltrating ductal carcinoma or ductal carcinoma in situ ≤3 cm and clear surgical margins, who were node negative, and had a planning target volume <120 cm{sup 3}. The outcomes included overall and disease-free survival and local and contralateral recurrence at 5 years. The true local recurrence rate was compared using 2-tailed paired t tests for estimates calculated using the Tufts University ipsilateral breast tumor recurrence and Memorial Sloan Kettering ductal carcinoma in situ nomograms. Results: The cohort included 134 patients, and the observed local recurrence rate at a median follow-up period of 63 months was 1.2% ± 1.2%, similar to the estimate for whole breast irradiation (P=.23), significantly better than for surgery alone (relative risk 0.27; P<.001), and significantly lower than contralateral recurrence (relative risk 0.33; P<.001). The 5-year overall survival rate was 97.4% ± 1.9%, and the disease-free survival rate was 96.4% ± 2.1%. At 2 months, 42% of the patients had erythema, 20% induration, and 16% moist desquamation. The rate of mainly grade 1 telangiectasia was 22.4% at 2 years and 24% at 5 years. The rate of asymptomatic induration was 23% at 2 years and 40% at 5 years. Conclusions: The 5-year data suggest that permanent breast seed implantation is a safe accelerated partial breast irradiation option after lumpectomy for early-stage breast cancer with a tolerance profile similar to that of whole breast irradiation.

  11. First report of a permanent breast 103Pd seed implant as adjuvant radiation treatment for early-stage breast cancer

    International Nuclear Information System (INIS)

    Pignol, Jean-Philippe; Keller, Brian; Rakovitch, Eileen; Sankreacha, Raxa; Easton, Harry; Que, William

    2006-01-01

    Purpose: A new technique of adjuvant partial breast irradiation using 103 Pd permanent breast seed implants (PBSI) is presented. The procedure is performed in a single 1-hour session under local anesthesia. Methods and Materials: Patients referred to a single institution for adjuvant radiotherapy after lumpectomy for an infiltrating ductal carcinoma ≤3 cm in diameter, surgical margin ≥2 mm, no extensive in situ carcinoma, no lymphovascular invasion, and minimal or negative lymph node involvement were offered a PBSI. Results: Between May and December 2004, 31 eligible patients underwent CT scan and ultrasound simulations assessing PBSI feasibility. Fifteen were excluded because of feasibility issues, and 16 received PBSI. A minimal peripheral dose of 90 Gy was prescribed to the planning target volume corresponding to the clinical target volume identified on the CT scan plus a margin of 1 cm. The procedure was well tolerated; 56% of the patients reported no pain during the procedure, and 46% of the patients developed National Cancer Institute Common Toxicity Criteria Grade 1 acute reaction. None experienced toxicity Grade 2 or 3. Conclusions: Permanent breast seed implantation seems feasible and well tolerated on these preliminary clinical data and represents an ultimate step in the reduction of treatment fraction for partial breast irradiation

  12. Tolerance and Acceptance Results of a Palladium-103 Permanent Breast Seed Implant Phase I/II Study

    International Nuclear Information System (INIS)

    Pignol, Jean-Philippe; Rakovitch, Eileen; Keller, Brian M.; Sankreacha, Raxa; Chartier, Carole

    2009-01-01

    Purpose: To test, in a prospective Phase I/II trial, a partial breast irradiation technique using a 103 Pd permanent breast seed implant (PBSI) realized in a single 1-h procedure under sedation and local freezing. Methods and Materials: Eligible patients had infiltrating ductal carcinoma ≤3 cm in diameter, surgical margin ≥2 mm, no extensive intraductal component, no lymphovascular invasion, and negative lymph nodes. Patients received a permanent seed implant, and a minimal peripheral dose of 90 Gy was prescribed to the clinical target volume, with a margin of 1.5 cm. Results: From May 2004 to April 2007, 67 patients received the PBSI treatment. The procedure was well tolerated, with 17% of patients having significant pain after the procedure. Only 1 patient (1.5%) had an acute skin reaction (Grade 3 according to the National Cancer Institute Common Toxicity Criteria). The rates of acute moist desquamation, erythema, and indurations were 10.4%, 42%, and 27%, respectively. At 1 year the rate of Grade 1 telangiectasia was 14%. The rate of skin reaction decreased from 65% to 28% when skin received less than the 85% isodose. According to a Radiation Therapy Oncology Group questionnaire, 80-90% of patients were very satisfied with their treatment, and the remainder were satisfied. One patient (1.5%) developed an abscess, which resolved after the use of antibiotics. There was no recurrence after a median follow-up of 32 months (range, 11-49 months). Conclusions: The feasibility, safety, and tolerability of PBSI compares favorably with that of external beam and other partial breast irradiation techniques.

  13. Rapid-relocation model for describing high-fluence retention of rare gases implanted in solids

    Science.gov (United States)

    Wittmaack, K.

    2009-09-01

    It has been known for a long time that the maximum areal density of inert gases that can be retained in solids after ion implantation is significantly lower than expected if sputter erosion were the only limiting factor. The difference can be explained in terms of the idea that the trapped gas atoms migrate towards the surface in a series of detrapping-trapping events so that reemission takes place well before the receding surface has advanced to the original depth of implantation. Here it is shown that the fluence dependent shift and shape of implantation profiles, previously determined by Rutherford backscattering spectrometry (RBS), can be reproduced surprisingly well by extending a simple retention model originally developed to account only for the effect of surface recession by sputtering ('sputter approximation'). The additional migration of inert gas atoms is formally included by introducing an effective shift parameter Yeff as the sum of the sputtering yield Y and a relocation efficiency Ψrel. The approach is discussed in detail for 145 keV Xe + implanted in Si at normal incidence. Yeff was found to increase with increasing fluence, to arrive at a maximum equivalent to about twice the sputtering yield. At the surface one needs to account for Xe depletion and the limited depth resolution of RBS. The (high-fluence) effect of implanted Xe on the range distributions is discussed on the basis of SRIM calculations for different definitions of the mean target density, including the case of volume expansion (swelling). To identify a 'range shortening' effect, the implanted gas atoms must be excluded from the definition of the depth scale. The impact-energy dependence of the relocation efficiency was derived from measured stationary Xe concentrations. Above some characteristic energy (˜20 keV for Ar, ˜200 keV for Xe), Y exceeds Ψrel. With decreasing energy, however, Ψrel increases rapidly. Below 2-3 keV more than 90% of the reemission of Ar and Xe is estimated

  14. Effect of pre-implanted oxygen in Si on the retention of implanted He

    Energy Technology Data Exchange (ETDEWEB)

    Manuaba, A. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Paszti, F. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)]. E-mail: paszti@rmki.kfki.hu; Ramos, A.R. [ITN - Instituto Tecnologico e Nuclear, Estrada Nacional 10, P-2686-953, Sacavem (Portugal); Khanh, N.Q. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Pecz, B. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Zolnai, Z. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Tunyogi, A. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Szilagyi, E. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)

    2006-08-15

    Buried SiO {sub x} layers, with different x values, were formed by implanting 80 keV O{sup +} ions with different fluences into single crystal Si samples at room temperature. Into each of these O pre-implanted layers, 20 keV He{sup +} was implanted up to the fluence of 1 x 10{sup 17} ion/cm{sup 2}. The He distribution profiles were determined by 2045 keV proton backscattering spectrometry. It was found that as the O content increases, the retained He gradually decreases at the beginning, then rapidly falls at x = 0.6 till it disappears at x = 1.3. The process that leads to this phenomenon is discussed.

  15. Repair of Avascular Meniscus Tears with Electrospun Collagen Scaffolds Seeded with Human Cells.

    Science.gov (United States)

    Baek, Jihye; Sovani, Sujata; Glembotski, Nicholas E; Du, Jiang; Jin, Sungho; Grogan, Shawn P; D'Lima, Darryl D

    2016-03-01

    The self-healing capacity of an injured meniscus is limited to the vascularized regions and is especially challenging in the inner avascular regions. As such, we investigated the use of human meniscus cell-seeded electrospun (ES) collagen type I scaffolds to produce meniscal tissue and explored whether these cell-seeded scaffolds can be implanted to repair defects created in meniscal avascular tissue explants. Human meniscal cells (derived from vascular and avascular meniscal tissue) were seeded on ES scaffolds and cultured. Constructs were evaluated for cell viability, gene expression, and mechanical properties. To determine potential for repair of meniscal defects, human meniscus avascular cells were seeded and cultured on aligned ES collagen scaffolds for 4 weeks before implantation. Surgical defects resembling "longitudinal tears" were created in the avascular zone of bovine meniscus and implanted with cell-seeded collagen scaffolds and cultured for 3 weeks. Tissue regeneration and integration were evaluated by histology, immunohistochemistry, mechanical testing, and magentic resonance imaging. Ex vivo implantation with cell-seeded collagen scaffolds resulted in neotissue that was significantly better integrated with the native tissue than acellular collagen scaffolds or untreated defects. Human meniscal cell-seeded ES collagen scaffolds may therefore be useful in facilitating meniscal repair of avascular meniscus tears.

  16. 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.

  17. Masticatory function with implant-supported overdentures

    NARCIS (Netherlands)

    van Kampen, FMC; van der Bilt, A; Cune, MS; Fontijn-Tekamp, FA; Bosman, F

    The type of attachment that is used in implant-supported mandibular overdentures may influence the retention and stability of the prosthesis and, thus, masticatory function. In this within- subject cross- over clinical trial, we examined the hypothesis that greater retention and stability of the

  18. Implante subcutáneo de un carcinoma hepatocelular tras la punción aspiración con aguja fina Subcutaneous seeding of hepatocellular carcinoma after fine-needle percutaneous biopsy

    Directory of Open Access Journals (Sweden)

    D. Martínez Ramos

    2007-06-01

    Full Text Available Los implantes subcutáneos son una complicación rara tras la punción aspiración con aguja fina de los carcinomas hepatocelulares. Los autores describen un caso de implante subcutáneo neoplásico en una mujer de 70 años con cirrosis hepática por virus C complicada con un carcinoma hepatocelular. Se efectuó una punción aspiración con aguja fina en el segmento II hepático. El implante tumoral se desarrolló en el trayecto de la punción aspiración. La tumoración subcutánea fue extirpada quirúrgicamente y el estudio anatomopatológico confirmó que se trataba de un carcinoma hepatocelular bien diferenciado.Subcutaneous tumor seeding after fine-needle percutaneous biopsy for hepatocellular carcinoma is a rarely seen complication. The authors describe a case of subcutaneous neoplastic seeding in a 70-year-old woman with chronic hepatitis C virus complicated by hepatocellular carcinoma. Ultrasonically guided fine-needle aspiration biopsy was performed in segment II of the liver. The neoplastic seeding developed along the needle track used to carry out the fine-needle biopsy. The subcutaneous tumor was excised, and histological examination revealed a well-differentiated hepatocellular carcinoma.

  19. 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

  20. Deuterium implantation into Y{sub 2}O{sub 3}-doped and pure tungsten: Deuterium retention and blistering behavior

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, M. [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, Garching 85748 (Germany); Jacob, W., E-mail: wolfgang.jacob@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, Garching 85748 (Germany); Manhard, A.; Gao, L.; Balden, M.; Toussaint, U. von [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, Garching 85748 (Germany); Zhou, Z. [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China)

    2017-04-15

    The blistering and near-surface deuterium retention of a Y{sub 2}O{sub 3}-doped tungsten (W) and two different pure W grades were studied after exposure to deuterium (D) plasma at elevated temperatures (370, 450 and 570 K). Samples were exposed to a deuterium fluence of 6 × 10{sup 24} D m{sup −2} applying a moderate ion flux of about 9 × 10{sup 19} D m{sup −2} s{sup −1} at an ion energy of 38 eV/D. Morphological modifications at the surface were analyzed by confocal laser scanning microscopy and scanning electron microscopy. The D depth profiles and the accumulated D inventories within the topmost 8 μm were determined by nuclear reaction analysis. Blistering and deuterium retention were strongly dependent on the implantation temperature. In addition, blistering was sensitively influenced by the used tungsten grade, although the total amount of retained D measured by nuclear reaction analysis was comparable. Among the three different investigated tungsten grades, Y{sub 2}O{sub 3}-doped W exhibited the lowest degree of surface modification despite a comparable total D retention. - Highlights: •Y{sub 2}O{sub 3}-doped W and 2 pure W were exposed to D plasma at 370, 450 and 570 K. •D retention in all 3 materials is comparable. •D plasma exposure leads to blister formation on all investigated W grades. •Blister morphology and size distribution depend strongly on W grade. •Y{sub 2}O{sub 3}-doped W shows the lowest degree of surface modification.

  1. Seed yield components and their potential interaction in grasses - to what extend does seed weigth influence yield?

    DEFF Research Database (Denmark)

    Boelt, B; Gislum, R

    2010-01-01

     In a first-year seed crop of red fescue (Festuca rubra L.) the degree of lodging was controlled by the use of Moddus (Trinexapac-ethyl). Seed weight was found to increase by the decreasing degree of lodging prior to harvest. The higher seed weights were accompanied by higher yields even though...... the number of reproductive tillers and floret site utilization (FSU) were unaffected by the treatments. Seed yield is affected by several yield components and reflects the interaction between the seed yield potential (e.g. number of reproductive tillers, number of spikelets and florets/spikelet per...... reproductive tiller), the utilization of the potential (e.g. seed set, seed weight) and the realization of the seed yield potential, defined as the number of florets forming a saleable seed. The realization of the seed yield potential is affected by seed retention, seed weight and other traits associated...

  2. Evaluation of permanent I-125 prostate implants using radiography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Moerland, Marinus A.; Wijrdeman, Harm K.; Beersma, Robert; Bakker, Chris J.G.; Battermann, Jan J.

    1997-01-01

    Purpose: The aim of this study is the evaluation of permanent I-125 prostate implants using radiography and magnetic resonance imaging (MRI). Methods and Materials: Twenty-one patients underwent radiography on the simulator and MRI 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 seed-induced signal voids on MRI provided the seed positions in relation to the prostate. The prostate was contoured on the transversal magnetic resonance images, and dose-volume histograms were computed to evaluate the implants. The validity of the ellipsoidal prostate volume approximation, as applied in preimplant dose calculation, was assessed by comparison of ellipsoidal volumes given by prostate width, height, and length and prostate volumes obtained by a slice-by-slice contouring method, both on postimplant MRI. Prostate volume changes due to postimplant prostate swelling were assessed from radiographs taken at 3 days and 1 month after the implantation. Results: The seeds were readily identified on T 1 -weighted spin-echo images and matched with the seed distribution reconstructed from the isocentric radiographs. The matching error, averaged over 21 patients, amounted to 1.8 ± 0.4 mm (mean ± standard deviation). The fractions of the prostate volumes receiving the prescribed matched peripheral dose (MPD) ranged from 32 to 71% (mean ± standard deviation: 60 ± 10%). Prostate volumes, obtained by the contouring method on postimplant MRI, were a factor 1.5 ± 0.3 larger than the ellipsoidal volumes given by the prostate dimensions on postimplant MRI. Prostate volumes 3 days after the implantation were a factor 1.3 ± 0.2 larger than the prostate volumes 1 month after the implantation. Registration of the reconstructed seed distribution and the MR images showed inaccuracies in seed placement, for example, two or more seeds clustering together or seeds outside the prostate

  3. 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)

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  5. 15N tracer technique for studying efficiency of deep placed fertilizer through nutriseed holder in direct seeded rice

    International Nuclear Information System (INIS)

    Asha, V.S.; Arulmozhiselvan, K.

    2006-01-01

    In order to estimate N use efficiency in deep placement of NPK straight fertilizers, two pot experiments were conducted in high clay soil with direct seeded rice. 15 N urea was used as a tracer. A newly designed 'Nutriseed Holder' was used for simultaneous deep placement of fertilizers and sowing of seeds. Each holder had two cavities, one on top for holding seed and another one at bottom for holding fertilizer material. By implanting a holder in puddled soil, a rice hill was established. The length (5 or 10 cm) and width (8 or 12 mm) of nutriseed holder was standardized while evaluating the effect of Azolla, neem and seed inoculants. Appreciably, deep placement of plain NPK fertilizer in 12 mm holder placed at 5 cm depth recorded the highest grain yield with a yield increase of 81.8 per cent during rabi 2002 (cv CO 43) and 84.8 per cent during summer 2003 (cv CO 47) over broadcast application. Further, it increased recovery of added JSN in grain + straw to the tune of 57.1 per cent in rabi and 54.7 per cent in summer as compared to broadcast application (26.1% in rabi, 34.2 in summer). Deep placement enhanced more retention in soil (up to 9.0% in rabi, 14.6% in summer) whereas broadcast application enhanced more retention in Azolla biomass that was grown in floodwater (up to 2.3 % in rabi, 4.3 % in summer). Use of 12 mm width nutriseed holder aiding deep placement at 5 cm depth was found suitable for deriving high yield and N use efficiency. (author)

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

    International Nuclear Information System (INIS)

    Zhang Wenyi; Wang Huixing; Ding Yanqiu; Qu Ximei; Wang Liqin; Liu Zhongchao; Cui Songye; Jiao Ling

    2012-01-01

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

  7. 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)

  8. Image fusion techniques in permanent seed implantation

    Directory of Open Access Journals (Sweden)

    Alfredo Polo

    2010-10-01

    image fusion for permanent seed implantation.

  9. Mini-implants: alternative for oral rehabilitation of a child with ectodermal dysplasia.

    Science.gov (United States)

    Mello, Bianca Zeponi Fernandes; Silva, Thiago Cruvinel; Rios, Daniela; Machado, Maria Aparecida Andrade Moreira; Valarelli, Fabrício Pinelli; Oliveira, Thais Marchini

    2015-01-01

    Ectodermal dysplasia is a rare congenital disease that affects several structures of ectodermal origin. The most commonly related oral characteristics are hypodontia, malformed teeth and underdeveloped alveolar ridges. New alternative treatments are needed due to the failure of the conventional prosthesis retention. This case report outlines the oral rehabilitation treatment of a 9-year-old girl with ectodermal dysplasia. The treatment was performed with conventional prosthesis upon mini-implants. The mini-implants provided prosthetic retention. The patient reported a good adaptation of the dental prosthesis and satisfaction with the treatment. The increased self-esteem improved the socialization skills of the girl. In this case report, use of prosthesis with mini-implants was satisfactory for prosthetic retention. However, clinical studies with long-term follow-up are needed to test the mini-implants as an alternative for oral rehabilitation of children with ectodermal dysplasia.

  10. Genetics analysis of mutagenic effect on M1 and M2 of arabidopsis thaliana derived from the seeds implanted by low energy ion

    International Nuclear Information System (INIS)

    Chen Donghua; Liang Qianjin; Zhang Genfa; Zhang Wenjun; Zhang Xiangqi

    2001-01-01

    Ameliorated RAPD technique was used to analyze the variations and their genetic stability of the gene pool DNAs of M 1 generation of different ion implanted (into seeds) Arabidopsis thaliana and the individual plant DNAs of generations M 1 and M 2 . The analysis of the gene pool DNAs of generation M 1 suggested that: 53 of 178 random primers amplified differential fragments, and multiplication experiments testified that the PCR results of some primers showed considerable stability. The results revealed that variation percentages, within a certain limit, relates to implanting dosage. Particularly, the genetic stability analysis of generation M 2 certificates that: performing PCR analysis by means of the same primers of generation M 1 brought about variation bands identical with that of generation M 1 , so it is possible that variations induced by ion implanting may be truly hereditary

  11. Tooth Retained Implant: No More an Oxymoron

    Directory of Open Access Journals (Sweden)

    Divya Bhat

    2011-03-01

    Full Text Available Introduction: Periodontally af-fected teeth are treated in one of the two ways. (1 Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2 Tooth extrac-tion and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth becomes difficult to restore. Placing an implant within the root can make the retained root restorable. At the same time, as the implant is placed within the root surface it achieves a periodontal integration which dampens occlusal forces better than osseointegration. Therefore, such a “tooth retained implant” may serve as an additional treatment option with significant benefits over tooth retention and implant placement alone. The hypothesis: Implants placed within retained roots have shown cementum deposition and attachment of periodontal ligament fibers over their surface. This periodontal attachment may be able to dam-pen forces better than in an osseointegrated implant. Moreover, since an implant is being placed, the crown of the tooth can be resected and submerged. This prevents epithelial migration, allows for the periodontal ligament cells to populate the wound and favors regeneration.Evaluation of the hypothesis: The technique of placing implants within cavities prepared in the root and then submerging them are simple for any practitioner placing implants routinely.

  12. Role of nano-range amphiphilic polymers in seed quality enhancement of soybean and imidacloprid retention capacity on seed coatings.

    Science.gov (United States)

    Adak, Totan; Kumar, Jitendra; Shakil, Najam A; Pandey, Sushil

    2016-10-01

    Nano-size and wide-range solubility of amphiphilic polymers (having both hydrophilic and hydrophobic blocks) can improve uniformity in seed coatings. An investigation was carried out to assess the positive effect of amphiphilic polymers over hydrophilic or hydrophobic polymers as seed coating agents and pesticide carriers. Amphiphilic polymers with 127.5-354 nm micelle size were synthesized in the laboratory using polyethylene glycols and aliphatic di-acids. After 6 months of storage, germination of uncoated soybean seeds decreased drastically from 97.80 to 81.55%, while polymer-coated seeds showed 89.44-95.92% germination. Similarly, vigour index-1 was reduced from 3841.10 to 2813.06 for control seeds but ranged from 3375.59 to 3844.60 for polymer-coated seeds after 6 months. The developed imidacloprid formulations retained more pesticide on soybean seed coatings than did a commercial formulation (Gaucho(®) 600 FS). The time taken for 50% release of imidacloprid from seed coatings in water was 7.12-9.11 h for the developed formulations and 0.41 h for the commercial formulation. Nano-range amphiphilic polymers can be used to protect soybean seeds from ageing. Formulations as seed treatments may produce improved and sustained efficacy with minimum environmental contamination. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  13. Anatomic Customization of Root-Analog Dental Implants With Cone-Beam CT and CAD/CAM Fabrication: A Cadaver-Based Pilot Evaluation.

    Science.gov (United States)

    Evans, Zachary P; Renne, Walter G; Bacro, Thierry R; Mennito, Anthony S; Ludlow, Mark E; Lecholop, Michael K

    2018-02-01

    Existing root-analog dental implant systems have no standardized protocols regarding retentive design, surface manipulation, or prosthetic attachment design relative to the site's unique anatomy. Historically, existing systems made those design choices arbitrarily. For this report, strategies were developed that deliberately reference the adjacent anatomy, implant and restorable path of draw, and bone density for implant and retentive design. For proof of concept, dentate arches from human cadavers were scanned using cone-beam computed tomography and then digitally modeled. Teeth of interest were virtually extracted and manipulated via computer-aided design to generate root-analog implants from zirconium. We created a stepwise protocol for analyzing and developing the implant sites, implant design and retention, and prosthetic emergence and connection all from the pre-op cone-beam data. Root-analog implants were placed at the time of extraction and examined radiographically and mechanically concerning ideal fit and stability. This study provides proof of concept that retentive root-analog implants can be produced from cone-beam data while improving fit, retention, safety, esthetics, and restorability when compared to the existing protocols. These advancements may provide the critical steps necessary for clinical relevance and success of immediately placed root-analog implants. Additional studies are necessary to validate the model prior to clinical trial.

  14. Glioblastoma with spinal seeding

    International Nuclear Information System (INIS)

    Fakhrai, N.; Fazeny-Doerner, B.; Marosi, C.; Czech, T.; Diekmann, K.; Birner, P.; Hainfellner, J.A.; Prayer, D.

    2004-01-01

    Background: extracranial seeding of glioblastoma multiforme (GBM) is very rare and its development depends on several factors. This case report describes two patients suffering from GBM with spinal seeding. In both cases, the anatomic localization of the primary tumor close to the cerebrospinal fluid (CSF) was the main factor for spinal seeding. Case reports: two patients with GBM and spinal seeding are presented. After diagnosis of spinal seeding, both patients were highly symptomatic from their spinal lesions. Case 1 experienced severe pain requiring opiates, and case 2 had paresis of lower limbs as well as urinary retention/incontinence. Both patients were treated with spinal radiation therapy. Nevertheless, they died 3 months after diagnosis of spinal seeding. Results: in both patients the diagnosis of spinal seeding was made at the time of cranial recurrence. Both tumors showed close contact to the CSF initially. Even though the patients underwent intensive treatment, it was not possible to keep them in a symptom-free state. Conclusion: because of short survival periods, patients deserve optimal pain management and dedicated palliative care. (orig.)

  15. Glioblastoma with spinal seeding

    Energy Technology Data Exchange (ETDEWEB)

    Fakhrai, N.; Fazeny-Doerner, B.; Marosi, C. [Clinical Div. of Oncology, Dept. of Medicine I, Univ. of Vienna (Austria); Czech, T. [Dept. of Neurosurgery, Univ. of Vienna (Austria); Diekmann, K. [Dept. of Radiooncology, Univ. of Vienna (Austria); Birner, P.; Hainfellner, J.A. [Clinical Inst. for Neurology, Univ. of Vienna (Austria); Prayer, D. [Dept. of Neuroradiology, Univ. of Vienna (Austria)

    2004-07-01

    Background: extracranial seeding of glioblastoma multiforme (GBM) is very rare and its development depends on several factors. This case report describes two patients suffering from GBM with spinal seeding. In both cases, the anatomic localization of the primary tumor close to the cerebrospinal fluid (CSF) was the main factor for spinal seeding. Case reports: two patients with GBM and spinal seeding are presented. After diagnosis of spinal seeding, both patients were highly symptomatic from their spinal lesions. Case 1 experienced severe pain requiring opiates, and case 2 had paresis of lower limbs as well as urinary retention/incontinence. Both patients were treated with spinal radiation therapy. Nevertheless, they died 3 months after diagnosis of spinal seeding. Results: in both patients the diagnosis of spinal seeding was made at the time of cranial recurrence. Both tumors showed close contact to the CSF initially. Even though the patients underwent intensive treatment, it was not possible to keep them in a symptom-free state. Conclusion: because of short survival periods, patients deserve optimal pain management and dedicated palliative care. (orig.)

  16. Dose reduction in LDR brachytherapy by implanted prostate gold fiducial markers.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Lutgens, Ludy; Murrer, Lars; Afsharpour, Hossein; de Haas-Kock, Danielle; Visser, Peter; van Gils, Francis; Verhaegen, Frank

    2012-03-01

    The dosimetric impact of gold fiducial markers (FM) implanted prior to external beam radiotherapy of prostate cancer on low dose rate (LDR) brachytherapy seed implants performed in the context of combined therapy was investigated. A virtual water phantom was designed containing a single FM. Single and multi source scenarios were investigated by performing Monte Carlo dose calculations, along with the influence of varying orientation and distance of the FM with respect to the sources. Three prostate cancer patients treated with LDR brachytherapy for a recurrence following external beam radiotherapy with implanted FM were studied as surrogate cases to combined therapy. FM and brachytherapy seeds were identified on post implant CT scans and Monte Carlo dose calculations were performed with and without FM. The dosimetric impact of the FM was evaluated by quantifying the amplitude of dose shadows and the volume of cold spots. D(90) was reported based on the post implant CT prostate contour. Large shadows are observed in the single source-FM scenarios. As expected from geometric considerations, the shadows are dependent on source-FM distance and orientation. Large dose reductions are observed at the distal side of FM, while at the proximal side a dose enhancement is observed. In multisource scenarios, the importance of shadows appears mitigated, although FM at the periphery of the seed distribution caused underdosage (LDR brachytherapy seed implant dose distributions. Therefore, reduced tumor control could be expected from FM implanted in tumors, although our results are too limited to draw conclusions regarding clinical significance.

  17. 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.

  18. Estimating adhesive seed-dispersal distances : field experiments and correlated random walks

    NARCIS (Netherlands)

    Mouissie, AM; Lengkeek, W; van Diggelen, R

    1. In this study we aimed to estimate distance distributions of adhesively dispersed seeds and the factors that determine them. 2. Seed attachment and detachment were studied using field experiments with a real sheep, a sheep dummy and a cattle dummy. Seed-retention data were used in correlated

  19. 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.)

  20. 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.

  1. Study of CT-guided iodine-125 implantation in the treatment of rabbit VX2 tumor

    International Nuclear Information System (INIS)

    He Kewu; Gao Bin; Li Jiajia

    2008-01-01

    Objective: To evaluate the effect of CT-guided iodine-125 seed( 125 I) implantation to rabbit model VX2 tumor cell apoptosis. Methods: VX2 tumor cells were implanted into muscle of 40 rabbits legs, 3 weeks later, as the diameter of tumor reached 2 cm available for test. Randomly selected the sampling tumor on one leg of rabbit as for the test team and tumor on the contralateral leg as for control team. Under CT guidance, 125 I seeds were implanted into 20 tumor lesions of the test team, and hollow seeds were implanted into 20 tumor lesions of the control team. Instantly, 72 h, 1, 2, 3 w after operation, percutaneous tumor tissue sampling was done 0.5-1.0 cm and 1.0-1.5 cm away from seed implanted site under CT guidance; and apoptosis was investigated by FCM. Results: Instantly, 72 h, 1, 2, 3 w after treatment with iodine-125 ( 125 I) implantation, the tissue sampling away from seed 0.5-1.0 cm showed the apoptosis rates of control team and test team were respectively as follows: (5.43±0.67)% and (5.48±0.66)%, (P>0.05), (5.45±0.58)% and (11.60±0.87)%, (P O.05)of the control team and test team. Conclusions: 125 I seeds implantation can induce tumor cell apoptosis, beginning at 72 h and reached peak at 2 w and kept the high level here afterword. The apoptosis rate descended rapidly along with the increase of distance away from the 125 I seedling. (authors)

  2. 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

  3. CT-assisted transcutaneous interstitial implantation of thoracic tumors: Early experience

    International Nuclear Information System (INIS)

    Heelan, R.T.; Hilaris, B.S.; Anderson, L.; Caravelli, J.F.; Nori, D.; Martini, N.; Watson, R.C.; Linares, L.

    1986-01-01

    The authors have transcutaneously implanted I-125 radioactive seeds in six patients with thoracic tumors (three with lung cancer; three with metastases) to determine the feasibility of this procedure. In four patients the thoracic tumors were localized without evidence of distant metastases, but these patients were not candidates for resection because of chronic pulmonary disease. Tumor volume was measured on CT scans (with sagittal and coronal reconstructions) and the required number of seeds was determined based on tumor volume. Between 6 and 11 needles were placed in the tumor and the seeds were implanted as the needle was withdrawn. Between 40 and 60 seeds were implanted in each patient, under local anesthesia. In this preliminary series all patients were found to have tumor attached to pleura. Four of the six patients underwent implantation during a day-time admission to the institution's Adult Day Hospital. No patient suffered any complication as a result of the procedure. Four patients experienced a symptomatic relief of pain and a decrease in size of tumor bulk (local control). Two patients eventually exhibited renewed tumor growth in the edges of the implanted mass after 6 months; the authors plan to supplement future implantations with external radiation therapy. One patient underwent implantation after local recurrence of tumor, returned to work the day following the procedure, and is without evidence of local recurrence 18 months later. They are encouraged by these preliminary results, for several reasons: the lack of morbidity, the achievement of local control of tumor while avoiding surgery and its potential complications, and avoidance of hospital stay (with consequent financial savings). The intent is to expand this series to include patients with lung tumors not attached to pleura

  4. The analysis of proteome changes in sunflower seeds induced by N ...

    Indian Academy of Sciences (India)

    Madhu

    Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese ... ion, a proteomic analysis of N+ ion implantation seeds was developed. ... implantation were validated in course of plant development,.

  5. Mutation effect of ion implantation on tomato breeding

    International Nuclear Information System (INIS)

    Wu Baoshan; Ling Haiqiu; Mao Peihong; Jin Xiang; Zeng Xianxian

    2003-01-01

    The mutation effects of N + ion implantation on cultivated tomato, Catchup type and Eatable type were studied. The result show that the mutation ranges of single-fruit weight and fruit number per plant were increased and their mutation frequencies were high, however the effect of ion implantation on germination rate of seed and quality of fruit was very weak. Using doses of 4 x 10 16 and 6 x 10 16 N + /cm 2 , the yield was greatly improved. The optimum mutation dosage was slightly different for seed of 2 tomato lines

  6. Mandibular Two Mini Implants Overdenture Using Magnetic Attachments: A Case Report

    Directory of Open Access Journals (Sweden)

    Anna Miyayasu

    2017-12-01

    Full Text Available Many patients with an edentulous mandible struggle to use complete dentures. The instability of such dentures caused by the lack of retention, often causes discomfort, as well as functional and psychosocial problems, which can be signifcantly improved using implant overdentures with retentive attachments. This case report describes a successful case of a mandibular implant overdenture using two mini implants and magnetic attachments for an elderly edentulous patient. Case Report: A 62-year-old female with a thin mandibular bone ridge presented with complaints of pain caused by an unstable and unretentive complete mandibular denture. This patient received two mini implants (diameter: 2.6 mm; length: 12 mm with magnetic attachments. After three months, magnetic assemblies with magnetic attraction of 400 gf were incorporated into the intaglio surface of her mandibular overdenture. At 11 months, magnetic attraction was changed from 400 gf to 600 gf to provide a stronger magnetic force for improving the retention of this denture. Conclusion: Based on a two-year follow-up period, the mandibular two mini implants overdenture with magnetic attachments was successful in improving the patient’s general satisfaction with her dentures

  7. Implanted-tritium permeation experiments

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Holland, D.F.; Casper, L.A.; Hsu, P.Y.; Miller, L.G.; Schmunk, R.E.; Watts, K.D.; Wilson, C.J.; Kershner, C.J.; Rogers, M.L.

    1982-04-01

    In fusion reactors, charge exchange neutral atoms of tritium coming from the plasma will be implanted into the first wall and other interior structures. EG and G Idaho is conducting two experiments to determine the magnitude of permeation into the coolant streams and the retention of tritium in those structures. One experiment uses an ion gun to implant deuterium. The ion gun will permit measurements to be made for a variety of implantation energies and fluxes. The second experiment utilizes a fission reactor to generate a tritium implantation flux by the 3 He(n,p) 3 H reaction. This experiment will simulate the fusion reactor radiation environment. We also plan to verify a supporting analytical code development program, in progress, by these experiments

  8. Comparison of intraoperative dosimetric implant representation with postimplant dosimetry in patients receiving prostate brachytherapy.

    Science.gov (United States)

    Stone, Nelson N; Hong, Suzanne; Lo, Yeh-Chi; Howard, Victor; Stock, Richard G

    2003-01-01

    To compare the results of intraoperative dosimetry with those of CT-based postimplant dosimetry in patients undergoing prostate seed implantation. Seventy-seven patients with T1-T3 prostate cancer received an ultrasound-guided permanent seed implant (36 received (125)I, 7 (103)Pd, and 34 a partial (103)Pd implant plus external beam radiation therapy). The implantation was augmented with an intraoperative dosimetric planning system. After the peripheral needles were placed, 5-mm axial images were acquired into the treatment planning system. Soft tissue structures (prostate, urethra, and rectum) were contoured, and exact needle positions were registered. Seeds were placed with an applicator, and their positions were entered into the planning system. The dose distributions for the implant were calculated after interior needle and seed placement. Postimplant dosimetry was performed 1 month later on the basis of CT imaging. Prostate and urethral doses were compared, by using paired t tests, for the real-time dosimetry in the operating room (OR) and the postimplant dosimetry. The mean preimplant prostate volume was 39.8 cm(3), the postneedle planning volume was 41.5 cm(3) (psystem provides a close match to the actual delivered doses. These data support the use of this system to modify the implant during surgery to achieve more consistent dosimetry results.

  9. 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)

  10. 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)

  11. 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.

  12. [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.

  13. Implant-Retained Auricular Prosthesis: A Case Report

    OpenAIRE

    Ozturk, A. Nilgun; Usumez, Aslihan; Tosun, Zekeriya

    2010-01-01

    Extraoral implant retained prosthesis have been proven to be a predictable treatment option for maxillofacial rehabilitation. This case report describes the clinical and laboratory procedures for fabricating an auricular prosthesis. In this case report, an auricular prosthesis was fabricated for a patient who lost the left and right external ear in an electrical burn. Extraoral implants and bar-and-clip retention for the proper connection of the auricular prosthesis to implant were used. This...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-01-01

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

  15. Physical Properties of Silicone Gel Breast Implants.

    Science.gov (United States)

    Jewell, Mark L; Bengtson, Bradley P; Smither, Kate; Nuti, Gina; Perry, TracyAnn

    2018-04-28

    Surgical applications using breast implants are individualized operations to fill and shape the breast. Physical properties beyond shape, size, and surface texture are important considerations during implant selection. Compare form stability, gel material properties, and shell thickness of textured shaped, textured round, and smooth round breast implants from 4 manufacturers: Allergan, Mentor, Sientra, and Establishment Labs through bench testing. Using a mandrel height gauge, form stability was measured by retention of dimensions on device movement from a horizontal to vertical supported orientation. Dynamic response of gel material (gel cohesivity, resistance to gel deformation, energy absorption) was measured using a synchronized target laser following application of graded negative pressure. Shell thickness was measured using digital thickness gauge calipers. Form stability, gel material properties, and shell thickness differed across breast implants. Of textured shaped devices, Allergan Natrelle 410 exhibited greater form stability than Mentor MemoryShape and Sientra Shaped implants. Allergan Inspira round implants containing TruForm 3 gel had greater form stability, higher gel cohesivity, greater resistance to gel deformation, and lower energy absorption than those containing TruForm 2 gel and in turn, implants containing TruForm 1 gel. Shell thickness was greater for textured versus smooth devices, and differed across styles. Gel cohesivity, resistance to gel deformation, and energy absorption are directly related to form stability, which in turn determines shape retention. These characteristics provide information to aid surgeons choosing an implant based on surgical application, patient tissue characteristics, and desired outcome.

  16. Esthetic, functional, and prosthetic outcomes with implant-retained finger prostheses.

    Science.gov (United States)

    Aydin, Cemal; Nemli, Secil Karakoca; Yilmaz, Handan

    2013-04-01

    Traumatic amputation of fingers results in a serious impairment of hand function and affects the psychological status of the patients. The implant-retained finger prostheses are an alternative treatment. The aim of this case report is to represent the use of osseointegrated implants for retention of finger prostheses in a patient with amputated thumb and index finger. Dental implants were placed in the residual bone of the fingers using two-stage surgery. Custom-made attachments were used to provide retention between implants and silicone prostheses. Prosthetic fingernails were made of composite resin material. After 6 months, implants were clinically successful, and the patient was satisfied with the appearance and the function of the prostheses. The complications of broken prosthetic nail and mild discoloration were observed. Reconstruction of amputated fingers with implant-retained prosthesis is a worthwhile treatment providing esthetic, functional, and psychological benefits, although some complications might be experienced. Clinical relevance Implant-retained finger prostheses are an acceptable treatment modality for patients with amputated fingers. Evaluating implant prognosis, functional results and prosthetic results of the patients are necessary to address the benefits and complications of the treatment.

  17. Hydrogen retention studies on lithiated tungsten exposed to glow discharge plasmas under varying lithiation environments using Thermal Desorption Spectroscopy and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Castro, A. de, E-mail: alfonso.decastro@ciemat.es [Fusion National Laboratory-CIEMAT, Av Complutense 40, 28040 Madrid (Spain); Valson, P. [Max-Planck-Institut für Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald (Germany); Tabarés, F.L. [Fusion National Laboratory-CIEMAT, Av Complutense 40, 28040 Madrid (Spain)

    2017-04-15

    For the design of a Fusion Reactor based on a liquid lithium divertor target and a tungsten first wall at high temperature, the interaction of the wall material with plasmas of significant lithium content must be assessed, as issues like fuel retention, tungsten embrittlement and enhanced sputtering may represent a showstopper for the selection of the first wall material compatible with the presence of liquid metal divertor. In this work we address this topic for the first time at the laboratory level, hot W samples (100 °C) have been exposed to Glow Discharges of H{sub 2} or Li-seeded H{sub 2} followed by in situ thermal desorption studies (TDS) of the uptake of H{sub 2} on the samples. Pure and pre-lithiated tungsten was investigated in order to evaluate the differential effect of Li ion implantation on H retention. Global particle balance was also used for the determination of trapped H into the full W wall of the plasma chamber. A factor of 3-4 lower retention was deduced for samples and main W wall exposed to H/Li plasma than that measured on pre-lithiated W.

  18. Effect of modifying the screw access channels of zirconia implant abutment on the cement flow pattern and retention of zirconia restorations.

    Science.gov (United States)

    Wadhwani, Chandur; Chung, Kwok-Hung

    2014-07-01

    The effect of managing the screw access channels of zirconia implant abutments in the esthetic zone has not been extensively evaluated. The purpose of this study was to determine the effect of an insert placed within the screw access channel of an anterior zirconia implant abutment on the amount of cement retained within the restoration-abutment system and on the dislodging force. Thirty-six paired zirconia abutments and restorations were fabricated by computer-aided design and computer-aided manufacturing and were divided into 3 groups: open abutment, with the screw access channel unfilled; closed abutment, with the screw access channel sealed; and insert abutment, with a thin, tubular metal insert projection continuous with the screw head and placed into the abutment screw access channel. The restorations were cemented to the abutments with preweighed eugenol-free zinc oxide cement (TempBond NE). Excess cement was removed, and the weight of the cement that remained in the restoration-abutment system was measured. Vertical tensile dislodging forces were recorded at a crosshead speed of 5 mm/min after incubation in a 37°C water bath for 24 hours. The specimens were examined for the cement flow pattern into the screw access channel after dislodgement. Data were analyzed with ANOVA, followed by multiple comparisons by using the Tukey honestly significant difference test (α = .05). The mean (standard deviation) of retentive force values ranged from 108.1 ± 29.9 N to 148.3 ± 21.0 N. The retentive force values differed significantly between the insert abutment and both the open abutment (P abutment groups (P abutment and insert abutment being greater than closed abutment (P abutment with a metal insert significantly affected both the cement retained within the abutment itself and the retention capabilities of the zirconia restoration cemented with TempBond NE cement. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier

  19. Implant retained auricular prosthesis with a modified hader bar: a case report.

    Science.gov (United States)

    Lovely, M; Dathan, Pradeep C; Gopal, Dinesh; George, Biji Thomas; Chandrasekharan Nair, K

    2014-06-01

    Auricular prostheses for defects of external ear are retained either by mechanical means or implants. All implant retained prostheses are retained by various means such as bar and clip, magnetic attachments or a combination of bar, clip and magnets. The commonest problem encountered with the bar and clip system is loosening of the clip after 3-4 months. When magnets are used as retaining component they tend to corrode over a period of time. So various alternative retention methods which possess good retentive qualities, ease of reparability and patient friendly were tried. In the present case a newly modified Hader bar design which can act as an additional retentive feature apart from the clip is employed to increase retention. The major advantages in the modified Hader bar system were that only two implants were employed, the additional loops in the Hader bar prevented micro movements and the retentive acrylic locks were easy to repair if broken. The modified Hader bar has anti-rotational slots which prevents the sliding or rotation of the prosthesis which gave new confidence to the patient who was otherwise worried of inadvertent displacement of the ear prosthesis while playing.

  20. 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.

  1. SU-F-J-167: Use of MR for Permanent Prostate Implant Preplanning

    Energy Technology Data Exchange (ETDEWEB)

    Narayana, V; McLaughlin, P [Assarian Cancer Center, Novi, MI (United States); University of Michigan, Ann Arbor, MI (United States); Yao, B [Assarian Cancer Center, Novi, MI (United States)

    2016-06-15

    Purpose: To study the feasibility using MR imaging to improve target definition on ultrasound during permanent prostate implants and aid in source strength determination for treatment planning in the OR. Methods: Patients who receive permanent prostate implants undergo MR and CT imaging prior to the implant procedure to determine the volume of the prostate, bony restriction to the procedure, bladder extension, external sphincter length and neurovascular bundle. The volume of the prostate is generally used to order seeds for the procedure. In 10 patients, the MR was used as the preplanning study with the PTV defined as a 2 mm expansion of the MR prostate in all directions except the posterior. Various dose volume parameters for the MR prostate and the PTV were compared to the actual preplan developed and executed in the OR. In addition, there parameters were compared to the post implant dosimetry performed 3 weeks after the implant procedure. Results: The results show that the number of seeds used using MR and US (ultrasound) planning was generally with 2 seeds and the maximum difference was 7 seeds. There is no significant difference between any of the dose index parameters of V100, V150, V200, D99 and D90 parameters between MR planning, US planning and postimplant evaluation There was a significant difference between planned D99 (avg of 105%) and achieved D99 (avg 91%). Conclusion: MR imaging is an invaluable tool to improve target definition for permanent prostate implants. Use of MR images for preplanning improves the confidence with which source can be ordered for the procedure that is OR planned. Ordering a maximum of 10 seeds more than planned would be sufficient to deliver a plan in the OR using US. Moving ahead to non-rigid registration between MR ad US images could further increase the confidence level of MR planning.

  2. 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)

  3. 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)

  4. Seed displacements after permanent brachytherapy for prostate cancer in dependence on the prostate level

    International Nuclear Information System (INIS)

    Pinkawa, M.; Gagel, B.; Asadpour, B.; Piroth, M.D.; Klotz, J.; Eble, M.J.; Borchers, H.; Jakse, G.

    2008-01-01

    Purpose: to evaluate seed displacements after permanent prostate brachytherapy considering different prostate levels. Patients and methods: in 61 patients, postimplant CT scans were performed 1 day and 1 month after an implant with stranded seeds. Seed and prostate surface displacements were determined relative to pelvic bones. Four groups of seed locations were selected: seeds at the base (n = 305; B), at the apex (n = 305; A), close to the urethra (n = 306; U), and close to the rectal wall (n = 204; R). The length of two strands (always containing four seeds) per patient was measured in all CT scans and compared. Results: the largest inferior seed displacements were found at the base: mean 5.3 mm (B), 2.2 mm (A), 2.7 mm (U), 3.3 mm (R; p 3 vs. 41 cm 3 ; p < 0.001), a mean caudal prostate base displacement of 3.9 mm was found, whereas the mean inward displacement ranged from 1.2 to 1.6 mm at the remaining borders (lateral, anterior, posterior, apical). The analysis of the strand lengths revealed an implant compression between day 1 and 30 (mean 1.7 mm; p < 0.001). Conclusion: the largest prostate tissue and seed displacements were observed at the prostate base, associated with an implant compression. Predominantly inferior and posterior displacements implicate consequential smaller preplanning margins at the apex and the posterior prostate. (orig.)

  5. 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

  6. Automated matching of corresponding seed images of three simulator radiographs to allow 3D triangulation of implanted seeds

    Science.gov (United States)

    Altschuler, Martin D.; Kassaee, Alireza

    1997-02-01

    To match corresponding seed images in different radiographs so that the 3D seed locations can be triangulated automatically and without ambiguity requires (at least) three radiographs taken from different perspectives, and an algorithm that finds the proper permutations of the seed-image indices. Matching corresponding images in only two radiographs introduces inherent ambiguities which can be resolved only with the use of non-positional information obtained with intensive human effort. Matching images in three or more radiographs is an `NP (Non-determinant in Polynomial time)-complete' problem. Although the matching problem is fundamental, current methods for three-radiograph seed-image matching use `local' (seed-by-seed) methods that may lead to incorrect matchings. We describe a permutation-sampling method which not only gives good `global' (full permutation) matches for the NP-complete three-radiograph seed-matching problem, but also determines the reliability of the radiographic data themselves, namely, whether the patient moved in the interval between radiographic perspectives.

  7. Deuterium trapping in ion implanted and co-deposited beryllium oxide layers

    International Nuclear Information System (INIS)

    Markin, A.V.; Gorodetsky, A.E.; Zakharov, A.P.; Wu, C.H.

    2000-01-01

    Deuterium trapping in beryllium oxide films irradiated with 400 eV D ions has been studied by thermal desorption spectroscopy (TDS). It has been found that for thermally grown BeO films implanted in the range 300 - 900 K the total deuterium retention doesn't depend whereas TDS spectra do markedly on irradiation temperature. For R.T. implantation the deuterium is released in a wide range from 500 to 1100 K. At implantation above 600 K the main portion of retained deuterium is released in a single peak centered at about 1000 K. The similar TDS peak is measured for D/BeO co-deposited layer. In addition we correlate our implantation data on BeO with the relevant data on beryllium metal and carbon. The interrelations between deuterium retention and microstructure are discussed. (orig.)

  8. Chlorophyll b Reductase Plays an Essential Role in Maturation and Storability of Arabidopsis Seeds1[W

    Science.gov (United States)

    Nakajima, Saori; Ito, Hisashi; Tanaka, Ryouichi; Tanaka, Ayumi

    2012-01-01

    Although seeds are a sink organ, chlorophyll synthesis and degradation occurs during embryogenesis and in a manner similar to that observed in photosynthetic leaves. Some mutants retain chlorophyll after seed maturation, and they are disturbed in seed storability. To elucidate the effects of chlorophyll retention on the seed storability of Arabidopsis (Arabidopsis thaliana), we examined the non-yellow coloring1 (nyc1)/nyc1-like (nol) mutants that do not degrade chlorophyll properly. Approximately 10 times more chlorophyll was retained in the dry seeds of the nyc1/nol mutant than in the wild-type seeds. The germination rates rapidly decreased during storage, with most of the mutant seeds failing to germinate after storage for 23 months, whereas 75% of the wild-type seeds germinated after 42 months. These results indicate that chlorophyll retention in the seeds affects seed longevity. Electron microscopic studies indicated that many small oil bodies appeared in the embryonic cotyledons of the nyc1/nol mutant; this finding indicates that the retention of chlorophyll affects the development of organelles in embryonic cells. A sequence analysis of the NYC1 promoter identified a potential abscisic acid (ABA)-responsive element. An electrophoretic mobility shift assay confirmed the binding of an ABA-responsive transcriptional factor to the NYC1 promoter DNA fragment, thus suggesting that NYC1 expression is regulated by ABA. Furthermore, NYC1 expression was repressed in the ABA-insensitive mutants during embryogenesis. These data indicate that chlorophyll degradation is induced by ABA during seed maturation to produce storable seeds. PMID:22751379

  9. Prosthetic implant treatment of the edentulous maxilla with overdenture.

    Science.gov (United States)

    Inversini, M

    2006-10-01

    The literature concerning the success of prosthetic implant treatment with maxillary overdenture is reviewed, and variables affecting treatment from the implant and prosthetic standpoint are analysed. Guidelines for the fabrication of maxillary overimplants comparable to those for mandibular overimplants are still lacking, as are evidence-based prosthetic design concepts. Individual methods and techniques have been described, but evaluation standards for the outcome of maxillary prosthetic-implant treatment are lacking or individually interpreted. The biomechanics involved in the proposed system are described, together with the advantages of telescopic crowns for the retention of removable partial prosthesis supported by maxillary implants. The positive influence, in terms of long-term prognosis, of the perio-protective design of removable partial prostheses supported by maxillary overimplants is also discussed. The proposed system not only provides stability, support and retention for removable partial prostheses supported by maxillary implants, but also enables implant survival rates to be improved, both for biomechanical reasons and due to improved oral hygiene. The simplification of fabrication procedures, repair, rebasing and re-operating also reduce the cost of follow-up and improve the cost/benefit ratio. However, additional studies are needed to clarify the number and most appropriate distribution of implants, as well as the most favourable prosthetic designs for maxillary overimplants.

  10. Urinary morbidity following ultrasound-guided transperineal prostate seed implantation

    International Nuclear Information System (INIS)

    Gelblum, Daphna Y.; Potters, Louis; Ashley, Richard; Waldbaum, Robert; Wang Xiaohong; Leibel, Steven

    1999-01-01

    Purpose: To assess the urinary morbidity experienced by patients undergoing ultrasound-guided, permanent transperineal seed implantation for adenocarcinoma of the prostate. Methods and Materials: Between September 1992 and September 1997, 693 consecutive patients presented with a diagnosis of clinically localized adenocarcinoma of the prostate, and were treated with ultrasound-guided transperineal interstitial permanent brachytherapy (TPIPB). Ninety-three patients are excluded from this review, having received neoadjuvant antiandrogen therapy. TPIPB was performed with 125 I in 165 patients and with 103 Pd in 435 patients. Patients treated with implant alone received 160 Gy with 125 I (pre TG43) or 120 Gy with 103 Pd. One hundred two patients received preimplant, pelvic external beam radiation (XRT) to a dose of either 41.4 or 45 Gy because of high-risk features including PSA ≥ 10 and/or Gleason score ≥ 7. Combined modality patients received 120 Gy and 90 Gy, respectively for 125 I or 103 Pd. All patients underwent postimplant cystoscopy and placement of an indwelling Foley catheter for 24-48 h. Follow-up was at 5 weeks after implant, every 3 months for the first 2 years, and then every 6 months for subsequent years. Patients completed AUA urinary symptom scoring questionnaires at initial consultation and at each follow-up visit. Urinary toxicity was classified by the RTOG toxicity scale with the following adaptations; grade 1 urinary toxicity was symptomatic nocturia or frequency requiring none or minimal medical intervention such as phenazopyridine; grade 2 urinary toxicity was early obstructive symptomatology requiring alpha-blocker therapy; and grade 3 toxicity was considered that requiring indwelling catheters or posttreatment transurethral resection of the prostate for symptom relief. Log-rank analysis and Chi-square testing was performed to assess AUA score, prostate size, isotope selection, and the addition of XRT as possible prognosticators of

  11. Mandibular implant-supported overdentures: attachment systems, and number and locations of implants--Part I.

    Science.gov (United States)

    Warreth, Abdulhadi; Alkadhimi, Aslam Fadel; Sultan, Ahmed; Byrne, Caroline; Woods, Edel

    2015-01-01

    The use of dental implants in replacing missing teeth is an integral part of restorative dental treatment. Use of conventional complete dentures is associated with several problems such as lack of denture stability, support and retention. However, when mandibular complete dentures were used with two or more implants, an improvement in the patients' psychological and social well-being could be seen. There is general consensus that removable implant-supported overdentures (RISOs) with two implants should be considered as the first-choice standard of care for an edentulous mandible. This treatment option necessitates the use of attachment systems that connect the complete denture to the implant. Nevertheless, each attachment system has its inherent advantages and disadvantages, which should be considered when choosing a system. The first part of this article provides an overview on options available to restore the mandibular edentulous arch with dental implants. Different types of attachment systems, their features and drawbacks are also reviewed.

  12. Comparative analysis of adherence, viability, proliferation and morphology of umbilical cord tissue-derived mesenchymal stem cells seeded on different titanium-coated expanded polytetrafluoroethylene scaffolds

    International Nuclear Information System (INIS)

    Hollweck, Trixi; Marschmann, Michaela; Hartmann, Isabel; Akra, Bassil; Meiser, Bruno; Reichart, Bruno; Eissner, Guenther; Eblenkamp, Markus; Wintermantel, Erich

    2010-01-01

    Umbilical cord tissue comprises an attractive new source for mesenchymal stem cells. Umbilical cord tissue-derived mesenchymal stem cells (UCMSC) exhibit self-renewal, multipotency and immunological naivity, and they can be obtained without medical intervention. The transfer of UCMSC to the ischemic region of the heart may have a favorable impact on tissue regeneration. Benefit from typical cell delivery by injection to the infarcted area is often limited due to poor cell retention and survival. Another route of administration is to use populated scaffolds implanted into the infarcted zone. In this paper, the seeding efficiency of UCMSC on uncoated and titanium-coated expanded polytetrafluoroethylene (ePTFE) scaffolds with different surface structures was determined. Dualmesh (registered) (DM) offers a corduroy-like surface in contrast to the comparatively planar surface of cardiovascular patch (CVP). The investigation of adherence, viability and proliferation of UCMSC demonstrates that titanium-coated scaffolds are superior to uncoated scaffolds, independent of the surface structure. Microscopic images reveal spherical UCMSC seeded on uncoated scaffolds. In contrast, UCMSC on titanium-coated scaffolds display their characteristic spindle-shaped morphology and a homogeneous coverage of CVP. In summary, titanium coating of clinically approved CVP enhances the retention of UCMSC and thus offers a potential cell delivery system for the repair of the damaged myocardium.

  13. Comparative analysis of adherence, viability, proliferation and morphology of umbilical cord tissue-derived mesenchymal stem cells seeded on different titanium-coated expanded polytetrafluoroethylene scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Hollweck, Trixi; Marschmann, Michaela; Hartmann, Isabel; Akra, Bassil; Meiser, Bruno; Reichart, Bruno; Eissner, Guenther [Department of Cardiac Surgery, University of Munich, Marchioninistrasse 15, 81377 Munich (Germany); Eblenkamp, Markus; Wintermantel, Erich, E-mail: Guenther.Eissner@med.uni-muenchen.d [Chair of Medical Engineering, Technische Universitaet Muenchen, Boltzmannstrasse 15, 85748 Garching (Germany)

    2010-12-15

    Umbilical cord tissue comprises an attractive new source for mesenchymal stem cells. Umbilical cord tissue-derived mesenchymal stem cells (UCMSC) exhibit self-renewal, multipotency and immunological naivity, and they can be obtained without medical intervention. The transfer of UCMSC to the ischemic region of the heart may have a favorable impact on tissue regeneration. Benefit from typical cell delivery by injection to the infarcted area is often limited due to poor cell retention and survival. Another route of administration is to use populated scaffolds implanted into the infarcted zone. In this paper, the seeding efficiency of UCMSC on uncoated and titanium-coated expanded polytetrafluoroethylene (ePTFE) scaffolds with different surface structures was determined. Dualmesh (registered) (DM) offers a corduroy-like surface in contrast to the comparatively planar surface of cardiovascular patch (CVP). The investigation of adherence, viability and proliferation of UCMSC demonstrates that titanium-coated scaffolds are superior to uncoated scaffolds, independent of the surface structure. Microscopic images reveal spherical UCMSC seeded on uncoated scaffolds. In contrast, UCMSC on titanium-coated scaffolds display their characteristic spindle-shaped morphology and a homogeneous coverage of CVP. In summary, titanium coating of clinically approved CVP enhances the retention of UCMSC and thus offers a potential cell delivery system for the repair of the damaged myocardium.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  15. Six-year clinical outcome of single implant-retained mandibular overdentures--a pilot study.

    Science.gov (United States)

    Passia, Nicole; Wolfart, Stefan; Kern, Matthias

    2015-10-01

    The aim of this prospective pilot study was to evaluate the prosthodontic maintenance as well as the implant outcome of single implant-retained mandibular overdentures over an observation period of 6 years. Eleven edentulous patients received one single implant in the midline of the mandible. Denture bases were temporarily relined and 2 months later provided with a ball attachment for implant retention. Implant related parameters and prosthodontic maintenance interventions were assessed 4 weeks after implant loading and then once a year. Over a mean observation period of 75.9 months, no implant was lost. The most frequent prosthetic maintenance intervention was activation of the matrix due to loss of retention, followed by exchange of the female part. Eight denture bases had to be repaired after a fracture in the midline area. Within the limitations of this preliminary clinical study, the concept of a single midline implant to retain a mandibular complete denture was a successful treatment option for elderly edentulous patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Randomized study on the effect of single-implant versus two-implant retained overdentures on implant loss and muscle activity: a 12-month follow-up report.

    Science.gov (United States)

    Alqutaibi, A Y; Kaddah, A F; Farouk, M

    2017-06-01

    The objective was to evaluate and compare single- and two-implant retained overdentures for the rehabilitation of the edentulous mandible. Fifty-six edentulous subjects were eligible for inclusion. Using a random sampling system, a single implant or two implants were placed in the mandible. After 3 months, locator attachments were connected to the implants and the denture delivered with the retentive components incorporated in the denture base. Implant failure and muscle activity were evaluated at the 3-, 6-, and 12-month follow-up examinations. The study sample comprised 56 patients (32 male, 24 female), with a mean age of 58.2 years. A total of 84 implants were placed (28 in the single-implant group and 56 in the two-implant group). All patients completed the 12 months of follow-up. No significant differences were found between subjects in the two groups with respect to implant failure. With regard to improvements in muscle activity, the two-implant group showed statistically significant but perhaps not clinically important differences. Single-implant mandibular overdentures may be suggested as an alternative treatment modality for the rehabilitation of edentulous patients who cannot afford the cost of a two-implant overdenture. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  17. Retention/Diffusivity Studies in Free-Surface Flowing Liquid Lithium

    International Nuclear Information System (INIS)

    R.A. Stubbers; G.H. Miley; M. Nieto; W. Olczak; D.N. Ruzic; A. Hassanein

    2004-01-01

    FLIRE was designed to measure the hydrogen and helium retention and diffusivity in a flowing stream of liquid lithium, and it has accomplished these goals. Retention coefficients for helium in the flowing liquid stream were 0.1-2% for flow speeds of 44 cm/s and implantation energies between 500 and 2000 eV. The energy dependence of retention is linear for the energy range considered, as expected, and the dependence of retention on flow velocity fits the expected square-root of flow speed dependence. Estimates of the helium diffusion coefficient in the flowing lithium stream were ∼ 4 x 10 -7 cm 2 /s, and are independent of implantation energy. This value is much lower than expected, which could be due to several factors, such as mixing, bubble formation or surface film formation. In the case of hydrogen, long term retention and release mechanisms are of greatest importance, since this relates to tritium inventory in flowing lithium PFCs for fusion applications. The amount of hydride formation was measured for flowing lithium exposed to neutral deuterium gas. Thermal desorption spectroscopy (TDS) measurements indicate that the hydride concentration was between 0.1 and 0.2% over a wide range of pressures (6.5 x 10 -5 to 1 Torr). This result implies that the deuterium absorption rate is limited by the surface dissociation rate, since deuterium (hydrogen/tritium) is absorbed in its atomic form, not its molecular form

  18. Retention/Diffusivity Studies in Free-Surface Flowing Liquid Lithium

    Energy Technology Data Exchange (ETDEWEB)

    R.A. Stubbers; G.H. Miley; M. Nieto; W. Olczak; D.N. Ruzic; A. Hassanein

    2004-12-14

    FLIRE was designed to measure the hydrogen and helium retention and diffusivity in a flowing stream of liquid lithium, and it has accomplished these goals. Retention coefficients for helium in the flowing liquid stream were 0.1-2% for flow speeds of 44 cm/s and implantation energies between 500 and 2000 eV. The energy dependence of retention is linear for the energy range considered, as expected, and the dependence of retention on flow velocity fits the expected square-root of flow speed dependence. Estimates of the helium diffusion coefficient in the flowing lithium stream were {approx} 4 x 10{sup -7} cm{sup 2}/s, and are independent of implantation energy. This value is much lower than expected, which could be due to several factors, such as mixing, bubble formation or surface film formation. In the case of hydrogen, long term retention and release mechanisms are of greatest importance, since this relates to tritium inventory in flowing lithium PFCs for fusion applications. The amount of hydride formation was measured for flowing lithium exposed to neutral deuterium gas. Thermal desorption spectroscopy (TDS) measurements indicate that the hydride concentration was between 0.1 and 0.2% over a wide range of pressures (6.5 x 10{sup -5} to 1 Torr). This result implies that the deuterium absorption rate is limited by the surface dissociation rate, since deuterium (hydrogen/tritium) is absorbed in its atomic form, not its molecular form.

  19. Biological effect of 20 keV N+ ion implantation on Stevia rebaudianum

    International Nuclear Information System (INIS)

    Su Tingting; Yang Tingting; Ji Guohong; Xiang Xingjia; Chen Xuetao; Wang Yu; Wu Yaojin

    2010-01-01

    The germinability and gemination rate of Stevia rebaudianum seeds implanted with 20 keV N + ions in doses of 0 (CK), 100 x 2500, 400 x 2500 and 1000 x 2500 N + /cm 2 were studied by analyzing the differences in seed germinability and gemination rate between the groups. By statistical analysis, the germinability and gemination rate were affected at the level of α=0.05 by the implantation dose. The results showed that the germinability and gemination rate increased with the dose first and then decreased. At 400 x 2500 N + /cm 2 , the seeds had the largest germinability and the gemination rate. (authors)

  20. WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Park, S; Song, D; Lee, J [Johns Hopkins University, Baltimore, MD (United States); Le, Y [Indiana University, Indianapolis, IN (United States)

    2016-06-15

    Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed by geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of prostate D

  1. WE-AB-BRA-12: Post-Implant Dosimetry in Prostate Brachytherapy by X-Ray and MRI Fusion

    International Nuclear Information System (INIS)

    Park, S; Song, D; Lee, J; Le, Y

    2016-01-01

    Purpose: For post-implant dosimetric assessment after prostate brachytherapy, CT-MR fusion approach has been advocated due to the superior accuracy on both seeds localization and soft tissue delineation. However, CT deposits additional radiation to the patient, and seed identification in CT requires manual review and correction. In this study, we propose an accurate, low-dose, and cost-effective post-implant dosimetry approach based on X-ray and MRI. Methods: Implanted seeds are reconstructed using only three X-ray fluoroscopy images by solving a combinatorial optimization problem. The reconstructed seeds are then registered to MR images using an intensity-based points-to-volume registration. MR images are first pre-processed by geometric and Gaussian filtering, yielding smooth candidate seed-only images. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine followed by local deformable registrations. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. Results: We tested our algorithm on twenty patient data sets. For quantitative evaluation, we obtained ground truth seed positions by fusing the post-implant CT-MR images. Seeds were semi-automatically extracted from CT and manually corrected and then registered to the MR images. Target registration error (TRE) was computed by measuring the Euclidean distances from the ground truth to the closest registered X-ray seeds. The overall TREs (mean±standard deviation in mm) are 1.6±1.1 (affine) and 1.3±0.8 (affine+deformable). The overall computation takes less than 1 minute. Conclusion: It has been reported that the CT-based seed localization error is ∼1.6mm and the seed localization uncertainty of 2mm results in less than 5% deviation of prostate D

  2. Volume study pre and post-implant brachytherapy prostate for establishment of PTV margins; Estudio de volumenes pre y post-implante en braquiterapia de prostata para establecimiento de margenes del PTV

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

    Treatment of prostate cancer by permanent implantation of radioactive seeds is now a good alternative to radical surgery or radiotherapy, as it provides a good tumor control while the risk is reduced by a lower complication irradiation of adjacent healthy organs. The large volume change during seed implantation occurs in the prostate of the patient, makes it important to consider margins around the organs of interest both to ensure optimal coverage and minimal tumor irradiation of healthy tissue. Analyze how the volume varies during and after implantation and establish a margin around the prostate to the practice of our hospital are the two objectives of this work.

  3. 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

  4. Fabricating a Mandibular Implant Supported Overdenture with a Suspended Framework

    OpenAIRE

    Ahuja, Swati; Jain, Vinay; Cagna, David; Wicks, Russell

    2012-01-01

    The introduction of implant-supported overdentures as a clinical alternative has improved the quality of life of the edentulous population. Implant-supported overdentures have diminished many of the problems associated with conventional dentures by providing improved retention, stability, function, esthetics and physical and emotional health. Greater support and stability of the implant borne prosthesis is associated with improved bite force and oral function for overdentures when compared to...

  5. The effect of seed morphology on the potential dispersal of aquatic macrophytes by the common carp (Cyprinus carpio)

    NARCIS (Netherlands)

    Pollux, B.J.A.; de Jong, M.D.E.; Steegh, A.; Ouborg, N.J.; Van Groenendael, J.M.; Klaassen, M.R.J.

    2006-01-01

    1. The potential for seed dispersal by fish (ichthyochory) will vary among aquatic plants because of differences in seed size and morphology. 2. To examine how seed morphology influences the probability of dispersal by the common carp (Cyprinus carpio), we studied seed ingestion, retention time and

  6. 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.

  7. Ectopic bone formation in nude rats using human osteoblasts seeded poly(3)hydroxybutyrate embroidery and hydroxyapatite-collagen tapes constructs.

    Science.gov (United States)

    Mai, Ronald; Hagedorn, Manolo Gunnar; Gelinsky, Michael; Werner, Carsten; Turhani, Dritan; Späth, Heike; Gedrange, Tomas; Lauer, Günter

    2006-09-01

    The aim of this study was to evaluate the ectopic bone formation using tissue engineered cell-seeded constructs with two different scaffolds and primary human maxillary osteoblasts in nude rats over an implantation period of up to 96 days. Collagen I-coated Poly(3)hydroxybutyrate (PHB) embroidery and hydroxyapatite (HAP) collagen tapes were seeded with primary human maxillary osteoblasts (hOB) and implanted into athymic rnu/run rats. A total of 72 implants were placed into the back muscles of 18 rats. 24, 48 and 96 days after implantation, histological and histomorphometric analyses were made. The osteoblastic character of the cells was confirmed by immunocytochemistry and RT-PCR for osteocalcin. Histological analysis demonstrated that all cell-seeded constructs induced ectopic bone formation after 24, 48 and 96 days of implantation. There was more mineralized tissue in PHB constructs than in HAP-collagen tapes (at day 24; p embroidery or HAP-collagen tapes can induce ectopic bone formation. However, the amount of bone formed decreased with increasing length of implantation.

  8. Fabrication of a Customized Ball Abutment to Correct a Nonparallel Implant Abutment for a Mandibular Implant-Supported Removable Partial Prosthesis: A Case Report

    OpenAIRE

    Hossein Dasht; Mohammadreza Nakhaei; Nafiseh teimouri

    2017-01-01

    Introduction: While using an implant-supported removable partial prosthesis, the implant abutments should be parallel to one another along the path of insertion. If the implants and their attachments are placed vertically on a similar occlusal plane, not only is the retention improved, the prosthesis will also be maintained for a longer period. Case Report: A 65-year-old male patient referred to the School of Dentistry in Mashhad, Iran with complaints of discomfort with the removable partial ...

  9. 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.

  10. Comparison of Three Attachments in Implant-Tissue Supported Overdentures: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    F. Alaie

    2010-09-01

    Full Text Available Objective: Retention and resistance of the implant-tissue supported overdenture may be affected by the type of attachment. The aim of this research was to compare the retention and resistance of Nobel Biocare Ball (NBB, Nobel Biocare Bar and Clip (NBBC andSterngold ERA Red (ERAR attachments on an implant-tissue supported overdenture model.Materials and Methods: The attachment samples were divided into 3 groups of NBB,NBBC, and ERAR (5 samples in each group. Two parallel Nobel Biocare Branemark implants were placed symmetrically at the symphysis region of a mandibular test model. A metallic overdenture was fabricated precisely adapted to the model and attached to aZwick testing machine (crosshead speed of 51 mm/min. Dislodging tensile forces were applied in three vertical, oblique, anterior-posterior directions and two situations, at the beginning and after 100 times of insertion/removal of the overdenture, for each sample.The maximum dislodging force was measured. A One-way ANOVA test was employed followed by Tukey’s test.Results: ERAR was the most retentive and resistant in both situations. NBB and NBBC showed the same anterior-posterior resistance at the beginning. All test groups representeda large amount of retention and resistance loss after the insertion/removal of the overdenture,while NBBC showed a higher loss of anterior-posterior resistance than NB.Conclusion: A highest level of retention and resistance was seen in ERAR. The retention and resistance were affected by the wear of attachments.

  11. Estimation of the tritium retention in ITER tungsten divertor target using macroscopic rate equations simulations

    Science.gov (United States)

    Hodille, E. A.; Bernard, E.; Markelj, S.; Mougenot, J.; Becquart, C. S.; Bisson, R.; Grisolia, C.

    2017-12-01

    Based on macroscopic rate equation simulations of tritium migration in an actively cooled tungsten (W) plasma facing component (PFC) using the code MHIMS (migration of hydrogen isotopes in metals), an estimation has been made of the tritium retention in ITER W divertor target during a non-uniform exponential distribution of particle fluxes. Two grades of materials are considered to be exposed to tritium ions: an undamaged W and a damaged W exposed to fast fusion neutrons. Due to strong temperature gradient in the PFC, Soret effect’s impacts on tritium retention is also evaluated for both cases. Thanks to the simulation, the evolutions of the tritium retention and the tritium migration depth are obtained as a function of the implanted flux and the number of cycles. From these evolutions, extrapolation laws are built to estimate the number of cycles needed for tritium to permeate from the implantation zone to the cooled surface and to quantify the corresponding retention of tritium throughout the W PFC.

  12. Local evolution of seed flotation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Susana Saez-Aguayo

    2014-03-01

    Full Text Available Arabidopsis seeds rapidly release hydrophilic polysaccharides from the seed coat on imbibition. These form a heavy mucilage layer around the seed that makes it sink in water. Fourteen natural Arabidopsis variants from central Asia and Scandinavia were identified with seeds that have modified mucilage release and float. Four of these have a novel mucilage phenotype with almost none of the released mucilage adhering to the seed and the absence of cellulose microfibrils. Mucilage release was modified in the variants by ten independent causal mutations in four different loci. Seven distinct mutations affected one locus, coding the MUM2 β-D-galactosidase, and represent a striking example of allelic heterogeneity. The modification of mucilage release has thus evolved a number of times independently in two restricted geographical zones. All the natural mutants identified still accumulated mucilage polysaccharides in seed coat epidermal cells. Using nuclear magnetic resonance (NMR relaxometry their production and retention was shown to reduce water mobility into internal seed tissues during imbibition, which would help to maintain seed buoyancy. Surprisingly, despite released mucilage being an excellent hydrogel it did not increase the rate of water uptake by internal seed tissues and is more likely to play a role in retaining water around the seed.

  13. Survival benefit of chemoembolization plus Iodine125 seed implantation in unresectable hepatitis B-related hepatocellular carcinoma with PVTT: a retrospective matched cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Mingsheng; Wang, Haofan; Chen, Junwei; Bai, Mingjun; Wang, Long; Zhu, Kangshun; Jiang, Zaibo; Guan, Shouhai; Li, Zhengran; Qian, Jiesheng; Li, Mingan; Pang, Pengfei; Shan, Hong [Sun Yat-sen University, Department of Radiology, the Third Affiliated Hospital, Guangzhou (China); Sun Yat-Sen University, Department of Interventional Radiology, Ling-nan Hospital, Guangzhou (China); Sun Yat-sen University, Interventional Radiology Institute, Guangzhou (China); Lin, Qu [Sun Yat-sen University, Department of Oncology, the Third Affiliated Hospital, Guangzhou (China)

    2016-10-15

    To investigate the survival benefit of transarterial chemoembolization (TACE) plus Iodine125 seed implantation (TACE-Iodine125) in hepatitis B-related HCC patients with portal vein tumour thrombus (PVTT) and the underlying prognostic factors. A retrospective matched cohort study was performed on consecutive HCC patients with PVTT from January 2011 to June 2014. Seventy patients (TACE-Iodine125 group) who underwent TACE-Iodine125 were compared with a historical case-matched control group of 140 patients (TACE group) who received TACE alone. The survival of patients and the underlying prognostic factors were analysed. The median survival times of the TACE-Iodine125 and TACE groups were 11.0 and 7.5 months, respectively (p < 0.001). The survival probability at 12, 24, and 36 months was 50 %, 14.5 %, and 14.5 % vs. 25 %, 9 %, and 5 % in the TACE-Iodine125 and TACE groups, respectively (p < 0.001). The PVTT responders had better survival than the PVTT non-responders (p < 0.001). For the PVTT non-responders, there were no differences in the survival curves between the groups (p = 0.353). Multivariate analysis showed that type III PVTT (p < 0.001) and APS (p < 0.001) were independent predictors of poor prognosis. In contrast, the treatment modality of TACE-Iodine125 (p < 0.001) and PVTT response (p = 0.001) were favourable prognostic features. TACE combined with Iodine125 seed implantation may be a good choice for selected HB-HCC patients with PVTT. (orig.)

  14. Dose calculation for permanent prostate implants incorporating spatially anisotropic linearly time-resolving edema

    International Nuclear Information System (INIS)

    Monajemi, T. T.; Clements, Charles M.; Sloboda, Ron S.

    2011-01-01

    Purpose: The objectives of this study were (i) to develop a dose calculation method for permanent prostate implants that incorporates a clinically motivated model for edema and (ii) to illustrate the use of the method by calculating the preimplant dosimetry error for a reference configuration of 125 I, 103 Pd, and 137 Cs seeds subject to edema-induced motions corresponding to a variety of model parameters. Methods: A model for spatially anisotropic edema that resolves linearly with time was developed based on serial magnetic resonance imaging measurements made previously at our center to characterize the edema for a group of n=40 prostate implant patients [R. S. Sloboda et al., ''Time course of prostatic edema post permanent seed implant determined by magnetic resonance imaging,'' Brachytherapy 9, 354-361 (2010)]. Model parameters consisted of edema magnitude, Δ, and period, T. The TG-43 dose calculation formalism for a point source was extended to incorporate the edema model, thus enabling calculation via numerical integration of the cumulative dose around an individual seed in the presence of edema. Using an even power piecewise-continuous polynomial representation for the radial dose function, the cumulative dose was also expressed in closed analytical form. Application of the method was illustrated by calculating the preimplant dosimetry error, RE preplan , in a 5x5x5 cm 3 volume for 125 I (Oncura 6711), 103 Pd (Theragenics 200), and 131 Cs (IsoRay CS-1) seeds arranged in the Radiological Physics Center test case 2 configuration for a range of edema relative magnitudes (Δ=[0.1,0.2,0.4,0.6,1.0]) and periods (T=[28,56,84] d). Results were compared to preimplant dosimetry errors calculated using a variation of the isotropic edema model developed by Chen et al. [''Dosimetric effects of edema in permanent prostate seed implants: A rigorous solution,'' Int. J. Radiat. Oncol., Biol., Phys. 47, 1405-1419 (2000)]. Results: As expected, RE preplan for our edema model

  15. Attachment of clips in a bar-retained maxillary implant overdenture : a clinical report

    NARCIS (Netherlands)

    Slot, J.W.A.; Raghoebar, G.M.; Dijk, G. van; Meijer, H.J.A.

    Implant-supported overdentures are a good alternative for patients with conventional dentures that lack retention and stability. The most common prosthetic complications in mandibular and maxillary implant-supported overdentures are fracture and loosening of the attachment system. This clinical

  16. Comparison of Separation of Seed Oil Triglycerides Containing Isomeric Conjugated Octadecatrienoic Acid Moieties by Reversed-Phase HPLC

    OpenAIRE

    Anh Van Nguyen; Victor Deineka; Lumila Deineka; Anh Vu Thi Ngoc

    2017-01-01

    Relative retention analysis and increment approach were applied for the comparison of triglycerides (TGs) retention of a broad set of plant seed oils with isomeric conjugated octadecatrienoic acids (CLnA) by reversed-phase HPLC for “propanol-2-acetonitrile” mobile phases and Kromasil 100-5C18 stationary phase with diode array detection (DAD) and mass spectrometric (MS) detection. The subjects of investigation were TGs of seed oils: Calendula officinalis, Catalpa ovata, Jacaranda mimosifolia, ...

  17. TRANSPLANTATION OF CRYOPRESERVED FETAL LIVER CELLS SEEDED INTO MACROPOROUS ALGINATE-GELATIN SCAFFOLDS IN RATS WITH LIVER FAILURE

    Directory of Open Access Journals (Sweden)

    D. V. Grizay

    2015-01-01

    Full Text Available Aim. To study the therapeutic potential of cryopreserved fetal liver cells seeded into macroporous alginategelatin scaffolds after implantation to omentum of rats with hepatic failure.Materials and methods.Hepatic failure was simulated by administration of 2-acetyl aminofl uorene followed partial hepatectomy. Macroporous alginate-gelatin scaffolds, seeded with allogenic cryopreserved fetal liver cells (FLCs were implanted into rat omentum. To prevent from colonization of host cells scaffolds were coated with alginate gel shell. Serum transaminase activity, levels of albumin and bilirubin as markers of hepatic function were determined during 4 weeks after failure model formation and scaffold implantation. Morphology of liver and scaffolds after implantation were examined histologically. Results. Macroporous alginate-gelatin scaffolds after implantation to healthy rats were colonized by host cells. Additional formation of alginate gel shell around scaffolds prevented the colonization. Implantation of macroporous scaffolds seeded with cryopreserved rat FLCs and additionally coated with alginate gel shell into omentum of rats with hepatic failure resulted in signifi cant improvement of hepatospecifi c parameters of the blood serum and positive changes of liver morphology. The presence of cells with their extracellular matrix within the scaffolds was confi rmed after 4 weeks post implantation.Conclusion. The data above indicate that macroporous alginate-gelatin scaffolds coated with alginate gel shell are promising cell carriers for the development of bioengineered liver equivalents.

  18. Computational and Experimental Evaluations of a Novel Thermo-Brachytherapy Seed for Treatment of Solid Tumors

    Science.gov (United States)

    Warrell, Gregory R.

    Hyperthermia has long been known as a radiation therapy sensitizer of high potential; however successful delivery of this modality and integrating it with radiation have often proved technically difficult. We present the dual-modality thermobrachytherapy (TB) seed, based on the ubiquitous low dose-rate (LDR) brachytherapy permanent implant, as a simple and effective combination of hyperthermia and radiation therapy. Heat is generated from a ferromagnetic or ferrimagnetic core within the seed, which produces Joule heating by eddy currents. A strategically-selected Curie temperature provides thermal self-regulation. In order to obtain a uniform and sufficiently high temperature distribution, additional hyperthermia-only (HT-only) seeds are proposed to be used in vacant spots within the needles used to implant the TB seeds; this permits a high seed density without the use of additional needles. Experimental and computational studies were done both to optimize the design of the TB and HT-only seeds and to quantitatively assess their ability to heat and irradiate defined, patient-specific targets. Experiments were performed with seed-sized ferromagnetic samples in tissue-mimicking phantoms heated by an industrial induction heater. The magnetic and thermal properties of the seeds were studied computationally in the finite element analysis (FEA) solver COMSOL Multiphysics, modelling realistic patient-specific seed distributions. These distributions were derived from LDR permanent prostate implants previously conducted at our institution; various modifications of the seeds' design were studied. The calculated temperature distributions were analyzed by generating temperature-volume histograms, which were used to quantify coverage and temperature homogeneity for a range of blood perfusion rates, as well as for a range of seed Curie temperatures and thermal power production rates. The impact of the interseed attenuation and scatter (ISA) effect on radiation dose distributions

  19. In vitro retention force measurement for three different attachment systems for implant-retained overdenture

    Directory of Open Access Journals (Sweden)

    Kareem Mohammed Reda

    2016-01-01

    Conclusion: Regardless of the initial retention level of overdenture attachment, gradual loss of retention values is inevitable. However, the rate of retention loss in overdenture attachments is higher in types which comprised plastic parts within their components, rather than those totally made up of noble metals.

  20. Neuromodulation by implant for treating lower urinary tract symptoms and dysfunction.

    Science.gov (United States)

    Bemelmans, B L; Mundy, A R; Craggs, M D

    1999-08-01

    Patients with irritative micturition complaints, pelvic pain, involuntary urine loss or urinary retention are sometimes difficult to treat. The advent of direct sacral nerve stimulation offers a therapeutic alternative if conservative measures fail and surgery is considered. This paper reviews therapeutic neuromodulation by implant for treating lower urinary tract symptoms and dysfunction. The international literature is reviewed on topics such as the physiological basis of neuromodulation, techniques of acute testing and chronic implantation, and clinical results. Future developments and ways for possible improvement are discussed. The mode of action of neuromodulation is probably through restoring the correct balance between excitatory and inhibitory impulses from and to the pelvic organs at a sacral and supra-sacral level. Depending on the predefined success criteria, average success rates of definitive implants vary from 50 to 70%. From the data it seems that patients with urge incontinence and urinary retention are the best candidates for neuromodulation. In the literature the lack of standardisation of selection criteria, stimulation parameters and definitions of success is striking. Neuromodulation by implant is a useful therapeutic alternative. It should at least be considered in patients with therapy-resistant urge incontinence and urinary retention before proceeding to surgery. Issues such as underlying physiology, methodological standardisation, technical improvements, and patient selection must be addressed in future research.

  1. Class solution for inversely planned permanent prostate implants to mimic an experienced dosimetrist

    International Nuclear Information System (INIS)

    Lessard, Etienne; Kwa, Stefan L. S.; Pickett, Barby; Roach, Mach III; Pouliot, Jean

    2006-01-01

    The purpose of this paper is to present a method for the selection of inverse planning parameters and to establish a set of inverse planning parameters (class solution) for the inverse planning included in a commercial permanent prostate implant treatment planning system. The manual planning of more than 750 patients since 1996 led to the establishment of general treatment planning rules. A class solution is tuned to fulfill the treatment planning rules and generate equivalent implants. For ten patients, the inverse planning is compared with manual planning performed by our experienced physicist. The prostate volumes ranged from 17 to 51 cc and are implanted with low activity I-125 seeds. Dosimetric indices are calculated for comparison. The inverse planning needed about 15 s for each optimization (400 000 iterations on a 2.5 GHz PC). In comparison, the physicist needed about 20 min to perform each manual plan. A class solution is found that consistently produces dosimetric indices equivalent or better than the manual planning. Moreover, even with strict seed placement rules, the inverse planning can produce adequate prostate dose coverage and organ at risk protection. The inverse planning avoids implant with seeds outside of the prostate and too close to the urethra. It also avoids needles with only one seed and needles with three consecutive seeds. This reduces the risk of complication due to seed misplacement and edema. The inverse planning also uses a smaller number of needles, reducing the cause of trauma. The quality of the treatment plans is independent of the gland size and shape. A class solution is established that consistently and rapidly produces equivalent dosimetric indices as manual planning while respecting severe seed placement rules. The class solution can be used as a starting point for every patient, dramatically reducing the time needed to plan individual patient treatments. The class solution works with inverse preplanning, intraoperative

  2. Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study.

    Science.gov (United States)

    Rodríguez-Pardo, D; Pigrau, C; Lora-Tamayo, J; Soriano, A; del Toro, M D; Cobo, J; Palomino, J; Euba, G; Riera, M; Sánchez-Somolinos, M; Benito, N; Fernández-Sampedro, M; Sorli, L; Guio, L; Iribarren, J A; Baraia-Etxaburu, J M; Ramos, A; Bahamonde, A; Flores-Sánchez, X; Corona, P S; Ariza, J

    2014-11-01

    We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; pInfection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

  3. Effects of high-dose hydrogen implantation on defect formation and dopant diffusion in silver implanted ZnO crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yaqoob, Faisal [Department of Physics, State University of New York at Albany, Albany, New York 12222 (United States); Huang, Mengbing, E-mail: mhuang@sunypoly.edu [College of Nanoscale Science and Engineering, State University of New York Polytechnic Institute, Albany, New York 12203 (United States)

    2016-07-28

    This work reports on the effects of a deep high-dose hydrogen ion implant on damage accumulation, defect retention, and silver diffusion in silver implanted ZnO crystals. Single-crystal ZnO samples were implanted with Ag ions in a region ∼150 nm within the surface, and some of these samples were additionally implanted with hydrogen ions to a dose of 2 × 10{sup 16 }cm{sup −2}, close to the depth ∼250 nm. Rutherford backscattering/ion channeling measurements show that crystal damage caused by Ag ion implantation and the amount of defects retained in the near surface region following post-implantation annealing were found to diminish in the case with the H implantation. On the other hand, the additional H ion implantation resulted in a reduction of substitutional Ag atoms upon post-implantation annealing. Furthermore, the presence of H also modified the diffusion properties of Ag atoms in ZnO. We discuss these findings in the context of the effects of nano-cavities on formation and annihilation of point defects as well as on impurity diffusion and trapping in ZnO crystals.

  4. Retention characteristics of hydrogen isotopes in JT-60U

    International Nuclear Information System (INIS)

    Masaki, K.; Sugiyama, K.; Hayashi, T.; Ochiai, K.; Gotoh, Y.; Shibahara, T.; Hirohata, Y.; Oya, Y.; Miya, N.; Tanabe, T.

    2005-01-01

    Erosion/deposition distribution and hydrogen isotope behavior in the JT-60U plasma-facing wall were investigated. Distribution of the tritium, which was produced by D-D nuclear reaction, was not correlated with erosion/deposition distribution. The tritium distribution can be explained by the distribution of high-energy tritium ion-implantation due to ripple loss. Deuterium distribution in the divertor region was different from the tritium distribution and not well correlated with the deposition. The highest D/C was ∼0.05 at the bottom of the outer dome wing, which is much less than that observed in other tokamaks. For the deuterium retention, at least two retention processes (ion-implantation and co-deposition) were found on the dome region. The systematic dust collection gave the small amount of dust (∼7 g: 0.2 mg/s production) in the whole vessel of JT-60U. Deposition was observed at the remote area of the outer divertor region

  5. Bone-anchored titanium implants for auricular rehabilitation: case report and review of literature.

    Science.gov (United States)

    Gumieiro, Emne Hammoud; Dib, Luciano Lauria; Jahn, Ricardo Schmitutz; Santos Junior, João Ferreira dos; Nannmark, Ulf; Granström, Gösta; Abrahão, Márcio

    2009-01-01

    Osseointegrated implants have acquired an important role in the prosthetic rehabilitation of patients with craniofacial defects. The main indications are lack of local tissue for autogenous reconstruction, previous reconstruction failure and selection of this technique by the patient. This paper presents a clinical case and discusses indications and advantages of the osseointegrated implant technique for retention of auricular prostheses. Case report, Universidade Federal de São Paulo (UNIFESP). A female patient received three auricular implants after surgical resection of a hemangioma in her left ear. The time taken for osseointegration of the temporal bone was three months. After fabrication of the implant-retained auricular prosthesis, the patient was monitored for 12 months. The clinical parameters evaluated showed good postoperative healing, healthy peri-implant tissue, good hygiene and no loss of implants. Good hygiene combined with thin and immobile peri-implant soft tissues resulted in minimal complications. Craniofacial implant integration appears to be site-dependent; increasing age affects osseointegration in the temporal bone. The frequency of adverse skin reactions in peri-implant tissues is generally low. The surgical technique for rehabilitation using implant-retained auricular prostheses seems to be simple. It is associated with low rates of adverse skin reactions and long-term complications. Prostheses anchored by osseointegrated implants seem to provide better retention than do prostheses supported on spectacle frames, less risk of discoloration through the use of adhesives and better esthetic results than do prostheses anchored in the surgical cavity.

  6. The effects of metallic implants on electroporation therapies: feasibility of irreversible electroporation for brachytherapy salvage.

    Science.gov (United States)

    Neal, Robert E; Smith, Ryan L; Kavnoudias, Helen; Rosenfeldt, Franklin; Ou, Ruchong; Mclean, Catriona A; Davalos, Rafael V; Thomson, Kenneth R

    2013-12-01

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

  7. Seed displacements after permanent brachytherapy for prostate cancer in dependence on the prostate level

    Energy Technology Data Exchange (ETDEWEB)

    Pinkawa, M.; Gagel, B.; Asadpour, B.; Piroth, M.D.; Klotz, J.; Eble, M.J. [Dept. of Radiotherapy, RWTH Aachen (Germany); Borchers, H.; Jakse, G. [Dept. of Urology, RWTH Aachen (Germany)

    2008-10-15

    Purpose: to evaluate seed displacements after permanent prostate brachytherapy considering different prostate levels. Patients and methods: in 61 patients, postimplant CT scans were performed 1 day and 1 month after an implant with stranded seeds. Seed and prostate surface displacements were determined relative to pelvic bones. Four groups of seed locations were selected: seeds at the base (n = 305; B), at the apex (n = 305; A), close to the urethra (n = 306; U), and close to the rectal wall (n = 204; R). The length of two strands (always containing four seeds) per patient was measured in all CT scans and compared. Results: the largest inferior seed displacements were found at the base: mean 5.3 mm (B), 2.2 mm (A), 2.7 mm (U), 3.3 mm (R; p < 0.001). Posterior displacements predominated both at the base and the central region: mean 2.2 mm (B), 2.0 mm (U), 0.8 mm (A), -0.6 mm (R; p < 0.001). With a decreasing edema between day 1 and 30 (mean prostate volume of 51 cm{sup 3} vs. 41 cm{sup 3}; p < 0.001), a mean caudal prostate base displacement of 3.9 mm was found, whereas the mean inward displacement ranged from 1.2 to 1.6 mm at the remaining borders (lateral, anterior, posterior, apical). The analysis of the strand lengths revealed an implant compression between day 1 and 30 (mean 1.7 mm; p < 0.001). Conclusion: the largest prostate tissue and seed displacements were observed at the prostate base, associated with an implant compression. Predominantly inferior and posterior displacements implicate consequential smaller preplanning margins at the apex and the posterior prostate. (orig.)

  8. RAPD analysis of alfalfa DNA mutation via N+ implantation

    International Nuclear Information System (INIS)

    Li Yufeng; Huang Qunce; Yu Zengliang; Liang Yunzhang

    2003-01-01

    Germination capacity of alfalfa seeds under low energy N + implantation manifests oscillations going down with dose strength. From analyzing alfalfa genome DNA under low energy N + implantation by RAPD (Random Amplified Polymorphous DNA), it is recommended that 30 polymorphic DNA fragments be amplified with 8 primers in total 100 primers, and fluorescence intensity of the identical DNA fragment amplified by RAPD is different between CK and treatments. Number of different polymorphic DNA fragments between treatment and CK via N + implantation manifests going up with dose strength

  9. Debridement, antibiotics, irrigation, and retention (DAIR) of the prosthesis after hip hemiarthroplasty infections. Does it work?

    Science.gov (United States)

    Kazimoglu, Cemal; Yalcin, Nadir; Onvural, Burak; Akcay, Serkan; Agus, Haluk

    2015-08-01

    Debridement, antibiotic, and implant retention (DAIR) is an attractive treatment modality after hip hemiarthroplasty (HA) infections. Data about the success of the procedure after acute onset infections is lacking. The aim of this study was to analyze the clinical outcome and associated risk factors. A multicenter, retrospective cohort study was designed, including 39 patients with acute onset prosthetic infection who had undergone debridement and irrigation with prosthesis retention. The primary outcome measure was infection eradication without prosthesis removal. We also analyzed how the success rate was influenced by the length of the interval between implantation of the prosthesis and the beginning of the treatment. The overall success rate was 41%. Sedimentation rate over 60 mm/h and the longer duration (2 weeks) after prosthesis implantation were found as factors negatively influencing the success rate. Our results indicated limited success to DAIR- treated patients with infected HA. The high failure rate of DAIR treatment after 2 weeks from the implantation should be taken into consideration.

  10. A Sequential Approach to Implant-Supported Overdentures.

    Science.gov (United States)

    Kosinski, Timothy

    2016-03-01

    Fabrication of implant-supported maxillary or mandibular overdentures can seem to be difficult procedures. Many things could go wrong and/or unnoticed until the fabrication has been completed. Implants must be correctly surgically placed in viable bone at the proper angulation and spacing within an arch. The type of attachment must be considered and future treatment of the appliance should be simple and efficient. The appliance must function not only initially but also for many years to come. The author has found the use of the GPS attachment to be an ideal tool to achieve the goals of retention and stability. Careful planning is the most important part of this process, and understanding the benefits and risks of creating overdentures should be well understood by the dentists. By sequentially planning and treating these types of cases, the patient is able to function reasonably during the stages of implant healing. The final prosthesis is created and remaining teeth that held the transitional appliance in place are remove on the day of final seating. This is an excellent simplified retentive system option for those patients who are anxious about losing their teeth, even those teeth that are diseased and ugly.

  11. Fabrication of a Customized Ball Abutment to Correct a Nonparallel Implant Abutment for a Mandibular Implant-Supported Removable Partial Prosthesis: A Case Report

    Directory of Open Access Journals (Sweden)

    Hossein Dasht

    2017-12-01

    Full Text Available Introduction: While using an implant-supported removable partial prosthesis, the implant abutments should be parallel to one another along the path of insertion. If the implants and their attachments are placed vertically on a similar occlusal plane, not only is the retention improved, the prosthesis will also be maintained for a longer period. Case Report: A 65-year-old male patient referred to the School of Dentistry in Mashhad, Iran with complaints of discomfort with the removable partial dentures for his lower mandible. Due to the lack of parallelism in the supporting implants, prefabricated ball abutment could not be used. As a result, a customized ball abutment was fabricated in order to correct the non-parallelism of the implants. Conclusion: Using UCLA abutments could be a cost-efficient approach for the correction of misaligned implant abutments in implant-supported overdentures.

  12. Temperature dependence of deuterium retention mechanisms in tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Roszell, J.P. [University of Toronto Institute for Aerospace Studies, 4925 Dufferin Street, Toronto, Ontario, M3H 5T6 (Canada); Davis, J.W., E-mail: jwdavis@starfire.utias.utoronto.ca [University of Toronto Institute for Aerospace Studies, 4925 Dufferin Street, Toronto, Ontario, M3H 5T6 (Canada); Haasz, A.A. [University of Toronto Institute for Aerospace Studies, 4925 Dufferin Street, Toronto, Ontario, M3H 5T6 (Canada)

    2012-10-15

    The retention of 500 eV D{sup +} was measured as a function of implantation temperature in single- (SCW) and poly-crystalline (PCW) tungsten. The results show a decrease in retention of {approx}2 orders of magnitude over the temperature range of 350-550 K in SCW and a decrease of an order of magnitude over the temperature range of 600-700 K in PCW. Inspection of the TDS spectra showed a shift in peak location from 600 to 800 K as temperature was increased above 350 K in SCW and above 450 K in PCW specimens. TMAP modeling showed that the change in peak location corresponds to a change in trapping energy from 1.3 eV for the 600 K peak to 2.1 eV for the 800 K peak. It is proposed that for implantations performed above 350 K in SCW and 450 K in PCW, deuterium-containing vacancies are able to diffuse and combine to create stable nano-bubbles within the crystal lattice. The formation of nano-bubbles due to the annihilation of deuterium-vacancy complexes results in a change in the trapping energy from 1.3 to 2.1 eV as well as a decrease in retention as some of the deuterium-vacancy complexes will be destroyed at surfaces or grain boundaries, decreasing the number of trapping sites available.

  13. Temperature dependence of deuterium retention mechanisms in tungsten

    International Nuclear Information System (INIS)

    Roszell, J.P.; Davis, J.W.; Haasz, A.A.

    2012-01-01

    The retention of 500 eV D + was measured as a function of implantation temperature in single- (SCW) and poly-crystalline (PCW) tungsten. The results show a decrease in retention of ∼2 orders of magnitude over the temperature range of 350–550 K in SCW and a decrease of an order of magnitude over the temperature range of 600–700 K in PCW. Inspection of the TDS spectra showed a shift in peak location from 600 to 800 K as temperature was increased above 350 K in SCW and above 450 K in PCW specimens. TMAP modeling showed that the change in peak location corresponds to a change in trapping energy from 1.3 eV for the 600 K peak to 2.1 eV for the 800 K peak. It is proposed that for implantations performed above 350 K in SCW and 450 K in PCW, deuterium-containing vacancies are able to diffuse and combine to create stable nano-bubbles within the crystal lattice. The formation of nano-bubbles due to the annihilation of deuterium-vacancy complexes results in a change in the trapping energy from 1.3 to 2.1 eV as well as a decrease in retention as some of the deuterium-vacancy complexes will be destroyed at surfaces or grain boundaries, decreasing the number of trapping sites available.

  14. Temperature dependence of deuterium retention mechanisms in tungsten

    Science.gov (United States)

    Roszell, J. P.; Davis, J. W.; Haasz, A. A.

    2012-10-01

    The retention of 500 eV D+ was measured as a function of implantation temperature in single- (SCW) and poly-crystalline (PCW) tungsten. The results show a decrease in retention of ˜2 orders of magnitude over the temperature range of 350-550 K in SCW and a decrease of an order of magnitude over the temperature range of 600-700 K in PCW. Inspection of the TDS spectra showed a shift in peak location from 600 to 800 K as temperature was increased above 350 K in SCW and above 450 K in PCW specimens. TMAP modeling showed that the change in peak location corresponds to a change in trapping energy from 1.3 eV for the 600 K peak to 2.1 eV for the 800 K peak. It is proposed that for implantations performed above 350 K in SCW and 450 K in PCW, deuterium-containing vacancies are able to diffuse and combine to create stable nano-bubbles within the crystal lattice. The formation of nano-bubbles due to the annihilation of deuterium-vacancy complexes results in a change in the trapping energy from 1.3 to 2.1 eV as well as a decrease in retention as some of the deuterium-vacancy complexes will be destroyed at surfaces or grain boundaries, decreasing the number of trapping sites available.

  15. Sci-Sat AM(2): Brachy-05: Dosimetry effects of the TG-43 approximations for two iodine seeds in LDR brachytherapy.

    Science.gov (United States)

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

    2008-07-01

    This work consists of studying the interseed and tissue composition effects for two model iodine seeds: the IBt Interseed-125 and the 6711 model seed. Three seeds were modeled with the MCNP MC code in a water sphere to evaluate the interseed effect. The dose calculated at different distances from the centre was compared to the dose summed when the seeds were simulated separately. The tissue composition effect was studied calculating the radial dose function for different tissues. Before carrying out post-implant studies, the absolute dose calculated by MC was compared to experiment results: with LiF TLDs in an acrylic breast phantom and with an EBT Gafchromic film placed in a water tank. Afterwards, the TG-43 approximation effects were studied for a prostate and breast post-implant. The interseed effect study shows that this effect is more important for model 6711 (15%) than for IBt (10%) due to the silver rod in 6711. For both seed models the variations of the radial dose function as a function of the tissue composition are quasi similar. The absolute dose comparisons between MC calculations and experiments give good agreement (inferior to 3% in general). For the prostate and breast post-implant studies, a 10% difference between MC calculations and the TG-43 is found for both models of seeds. This study shows that the differences in dose distributions between TG43 and MC are quite similar for the two models of seeds and are about 10% for the studied post-implant treatments. © 2008 American Association of Physicists in Medicine.

  16. One-Piece Implant-Retained Mandibular Overdentures By Pre-Fabricated Titanium Telescopic Attachments and Frictional Varnish: A Two-Year Prospective Study.

    Science.gov (United States)

    Nik, Shahram Namjoy; Nejatian, Touraj

    2016-12-01

    Clinical efficiency of one-piece screw-type implants with telescopic were attachments evaluated in this study. Twenty-four patients received a mandibular implant-supported overdenture and maxillary complete denture. Ninety-six one-piece implants were inserted in the inter-foraminal area. Implants were immediately loaded with an implant-retained overdenture and telescopic attachments which had frictional retention elements. There was 0.25±0.24 mm, 0.32±0.25 mm, 0.43±0.30 mm, 0.61±0.30 mm and of bone resorption after 3, 6, 12 and 24 months, respectively. The need to activate the frictional retention was the most common complication. Treatment outcomes for prefabricated telescopic retained overdentures on one-piece implants are similar to that obtained in cases of delayed loading. Copyright© 2016 Dennis Barber Ltd.

  17. Implant Mandibular Overdentures Retained by Immediately Loaded Implants: A 1-Year Randomized Trial Comparing the Clinical and Radiographic Outcomes Between Mini Dental Implants and Standard-Sized Implants.

    Science.gov (United States)

    Zygogiannis, Kostas; Aartman, Irene Ha; Parsa, Azin; Tahmaseb, Ali; Wismeijer, Daniel

    The aim of this 1-year randomized trial was to evaluate and compare the clinical and radiographic performance of four immediately loaded mini dental implants (MDIs) and two immediately loaded standard-sized tissue-level (STL) implants, placed in the interforaminal region of the mandible and used to retain mandibular overdentures (IODs) in completely edentulous patients. A total of 50 completely edentulous patients wearing conventional maxillary dentures and complaining about insufficient retention of their mandibular dentures were divided into two groups; 25 patients received four MDIs and 25 patients received two STL implants. The marginal bone loss (MBL) at the mesial and distal sides of each implant was assessed by means of standardized intraoral radiographs after a period of 1 year. Implant success and survival rates were also calculated. Immediate loading was possible for all patients in the first group. In the second group, an immediate loading protocol could not be applied for 10 patients. These patients were treated with a delayed loading protocol. A mean MBL of 0.42 ± 0.56 mm for the MDIs and 0.54 ± 0.49 mm for the immediately loaded STL implants was recorded at the end of the evaluation period. There was no statistically significant difference between the MDIs and the immediately loaded STL implants. Two MDIs failed, resulting in a survival rate of 98%. The success rate was 91%. For the immediately loaded conventional implants, the survival rate was 100% and the success rate 96.7% after 1 year of function. However, in 10 patients, the immediate loading protocol could not be followed. Considering the limitations of this short-term clinical study, immediate loading of four unsplinted MDIs or two splinted STL implants to retain mandibular overdentures seems to be a feasible treatment option. The marginal bone level changes around the MDIs were well within the clinically acceptable range.

  18. Deformable registration of x-ray to MRI for post-implant dosimetry in prostate brachytherapy

    Science.gov (United States)

    Park, Seyoun; Song, Danny Y.; Lee, Junghoon

    2016-03-01

    Post-implant dosimetric assessment in prostate brachytherapy is typically performed using CT as the standard imaging modality. However, poor soft tissue contrast in CT causes significant variability in target contouring, resulting in incorrect dose calculations for organs of interest. CT-MR fusion-based approach has been advocated taking advantage of the complementary capabilities of CT (seed identification) and MRI (soft tissue visibility), and has proved to provide more accurate dosimetry calculations. However, seed segmentation in CT requires manual review, and the accuracy is limited by the reconstructed voxel resolution. In addition, CT deposits considerable amount of radiation to the patient. In this paper, we propose an X-ray and MRI based post-implant dosimetry approach. Implanted seeds are localized using three X-ray images by solving a combinatorial optimization problem, and the identified seeds are registered to MR images by an intensity-based points-to-volume registration. We pre-process the MR images using geometric and Gaussian filtering. To accommodate potential soft tissue deformation, our registration is performed in two steps, an initial affine transformation and local deformable registration. An evolutionary optimizer in conjunction with a points-to-volume similarity metric is used for the affine registration. Local prostate deformation and seed migration are then adjusted by the deformable registration step with external and internal force constraints. We tested our algorithm on six patient data sets, achieving registration error of (1.2+/-0.8) mm in < 30 sec. Our proposed approach has the potential to be a fast and cost-effective solution for post-implant dosimetry with equivalent accuracy as the CT-MR fusion-based approach.

  19. Mutagenic effects of ion implantation on stevia

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Chen Qiufang; Lu Ting; Shu Shizhen

    1998-01-01

    Dry seeds of Stevia were implanted by 75 keV nitrogen and carbon ions with various doses. The biological effects in M 1 and mutation in M 2 were studied. The results showed that ion beam was able to induce variation on chromosome structure in root tip cells. The rate of cells with chromosome aberration was increased with ion beam dose. The rate of cells with chromosomal aberration was lower than that induced with γ-rays. Frequency of the mutation induced by implantation of N + and C + ions were higher than those induced by γ-rays. The rate of cell with chromosome aberration and in M 2 useful mutation induced by implantation of C + ion was higher than those induced by implantation of N + ion. Mutagenic effects Feng 1 x Riyuan and Riyuan x Feng 2 by implantation of N + and C + were higher than that of Jining and Feng 2

  20. Magnet-retained implant-supported overdentures: review and 1-year clinical report.

    Science.gov (United States)

    Ceruti, Paola; Bryant, S Ross; Lee, Jun-Ho; MacEntee, Michael I

    2010-01-01

    Open-field aluminum-nickle-cobalt magnets have been used in prosthodontics for many years, but success has been limited because these magnets are susceptible to corrosion by the saliva and because their retentive force is weak relative to the initial retention offered by mechanical attachments. More recently, magnets have been made from alloys of the rare earth elements samarium and neodymium, which provide stronger magnetic force per unit size. In addition, a new generation of laser-welded containers has improved protection from salivary corrosion. The current resurgence of interest in this type of attachment appears justified because, unlike mechanical attachments, magnets have potential for unlimited durability and might therefore be superior to mechanical ball or bar attachments for the retention of removable prostheses on implants. To date, no long-term prospective trials have been conducted to confirm the clinical durability of this new generation of magnets for retaining dentures on either teeth or implants. The aim of this study was to document initial clinical experiences and levels of satisfaction among edentulous patients treated with mandibular implant-supported overdentures retained using a new generation of rare-earth magnetic attachments. At the outset, all but one of the 17 patients had had several years of experience with implant-supported overdentures. During the first year, the mean overall satisfaction among these 17 patients increased from less than 70 to over 90 out of 100 (standardized visual analogue scale). No unusual difficulties were encountered in rendering the treatment or maintaining the attachments. This report offers preliminary evidence of the excellent potential of these magnets for retaining mandibular implant-supported overdentures.

  1. Bone-anchored titanium implants for auricular rehabilitation: case report and review of literature

    Directory of Open Access Journals (Sweden)

    Emne Hammoud Gumieiro

    Full Text Available CONTEXT AND OBJECTIVE: Osseointegrated implants have acquired an important role in the prosthetic rehabilitation of patients with craniofacial defects. The main indications are lack of local tissue for autogenous reconstruction, previous reconstruction failure and selection of this technique by the patient. This paper presents a clinical case and discusses indications and advantages of the osseointegrated implant technique for retention of auricular prostheses. TYPE OF STUDY: Case report, Universidade Federal de São Paulo (UNIFESP. METHODS: A female patient received three auricular implants after surgical resection of a hemangioma in her left ear. The time taken for osseointegration of the temporal bone was three months. After fabrication of the implant-retained auricular prosthesis, the patient was monitored for 12 months. RESULTS: The clinical parameters evaluated showed good postoperative healing, healthy peri-implant tissue, good hygiene and no loss of implants. Good hygiene combined with thin and immobile peri-implant soft tissues resulted in minimal complications. Craniofacial implant integration appears to be site-dependent; increasing age affects osseointegration in the temporal bone. The frequency of adverse skin reactions in peri-implant tissues is generally low. CONCLUSION: The surgical technique for rehabilitation using implant-retained auricular prostheses seems to be simple. It is associated with low rates of adverse skin reactions and long-term complications. Prostheses anchored by osseointegrated implants seem to provide better retention than do prostheses supported on spectacle frames, less risk of discoloration through the use of adhesives and better esthetic results than do prostheses anchored in the surgical cavity

  2. Sinking and fit of abutment of locking taper implant system

    Science.gov (United States)

    Moon, Seung-Jin; Kim, Hee-Jung; Son, Mee-Kyoung

    2009-01-01

    STATEMENT OF PROBLEM Unlike screw-retention type, fixture-abutment retention in Locking taper connection depends on frictional force so it has possibility of abutment to sink. PURPOSE In this study, Bicon® Implant System, one of the conical internal connection implant system, was used with applying loading force to the abutments connected to the fixture. Then the amount of sinking was measured. MATERIAL AND METHODS 10 Bicon® implant fixtures were used. First, the abutment was connected to the fixture with finger force. Then it was tapped with a mallet for 3 times and loads of 20 kg corresponding to masticatory force using loading application instrument were applied successively. The abutment state, slightly connected to the fixture without pressure was considered as a reference length, and every new abutment length was measured after each load's step was added. The amount of abutment sinking (mm) was gained by subtracting the length of abutment-fixture under each loading condition from reference length. RESULTS It was evident, that the amount of abutment sinking in Bicon® Implant System increased as loads were added. When loads of 20 kg were applied more than 5 - 7 times, sinking stopped at 0.45 ± 0.09 mm. CONCLUSION Even though locking taper connection type implant shows good adaption to occlusal force, it has potential for abutment sinking as loads are given. When locking taper connection type implant is used, satisfactory loads are recommended for precise abutment location. PMID:21165262

  3. Trapping behaviour of deuterium ions implanted into tungsten simultaneously with carbon ions

    International Nuclear Information System (INIS)

    Kobayashi, Makoto; Suzuki, Sachiko; Wang, Wanjing; Kurata, Rie; Kida, Katsuya; Oya, Yasuhisa; Okuno, Kenji; Ashikawa, Naoko; Sagara, Akio; Yoshida, Naoaki

    2009-01-01

    The trapping behaviour of deuterium ions implanted into tungsten simultaneously with carbon ions was investigated by thermal desorption spectroscopy (TDS) and x-ray photoelectron spectroscopy (XPS). The D 2 TDS spectrum consisted of three desorption stages, namely desorption of deuterium trapped by intrinsic defects, ion-induced defects and carbon with the formation of the C-D bond. Although the deuterium retention trapped by intrinsic defects was almost constant, that by ion-induced defects increased as the ion fluence increased. The retention of deuterium with the formation of the C-D bond was saturated at an ion fluence of 0.5x10 22 D + m -2 , where the major process was changed from the sputtering of tungsten with the formation of a W-C mixture to the formation of a C-C layer, and deuterium retention as the C-D bond decreased. It was concluded that the C-C layer would enhance the chemical sputtering of carbon with deuterium with the formation of CD x and the chemical state of carbon would control the deuterium retention in tungsten under C + -D 2 + implantation.

  4. Round window electrode insertion potentiates retention in the scala tympani.

    Science.gov (United States)

    Connor, Stephen E J; Holland, N Julian; Agger, Andreas; Leong, Annabelle C; Varghese, Re Ajay; Jiang, Dan; Fitzgerald O'Connor, Alec

    2012-09-01

    The round window membrane (RWM)-intentioned approach is superior to the traditional bony cochleostomy (BC) approach in obtaining electrode placement within the scala tympani (ST). Cochlear implant outcome is influenced by several factors, including optimal placement and retention of the electrode array within the ST. The present study aimed to assess whether the RWM route is superior to a traditional BC for placement and retention of the electrode array in the ST. This was a prospective consecutive non-randomized comparison study. All patients were implanted with the Advanced Bionics 1J electrode array. The RWM approach (n = 32) was compared with a traditional BC group (n = 33). The outcome measure was the electrode position as judged within the scalar chambers at four points along the basal turn using postoperative computed tomography (CT). When the mean position scores were compared, the RWM-intentioned group had significantly more electrodes directed towards the ST compartment than the BC group (p scala vestibuli.

  5. Rehabilitation with ear prosthesis linked to osseointegrated implants.

    Science.gov (United States)

    Goiato, Marcelo C; dos Santos, Daniela M; Haddad, Marcela F; Moreno, Amália

    2012-06-01

    The absence of an ear, which can be the result of a congenital malformation, surgical tumour resection or traumatic injury, is a significant aesthetic problem. Attachment of ear prostheses with adhesives can cause local irritation for the wearer and affect the colour of the prostheses. Use of implants in craniofacial reconstruction can improve the retention and stability of prostheses giving to patient greater comfort and security relative to adhesive attachment. The aim of this report was to present a clinical case of a mutilated patient who was rehabilitated by means of installing an ear prosthesis fixed through osseointegrated implants. The patient had two implants installed in the mastoid region that were linked by a bar, and a clip-type system was used. The ear prosthesis was constructed from medical-use silicone, pigmented to match the patient's skin colour and linked to the retention system. The patient's rehabilitation was satisfactory from both a functional and an aesthetic point of view, making it possible for the patient to return to a normal social life and regain lost self-esteem. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  6. Dosimetric study of permanent prostate brachytherapy utilizing 131Cs, 125I and 103Pd seeds

    International Nuclear Information System (INIS)

    Yang Ruijie; Wang Junjie; Zhang Hongzhi

    2009-01-01

    Objective: To compare the dosimetric differences of permanent prostate brachytherapy utilizing 131 Cs, 125 I and 103 Pd seeds. Methods: Twenty-five patients with T 1 -T 2 c prostate cancer who had previously implanted with 125 I seeds were randomly selected in our study. The patients were re-planned with 131 Cs, 125 I and 103 Pd seeds by using the Prowess Brachytherapy 3.1 planning system to the prescription doses of 115 Gy, 145 Gy and 125 Gy, respectively. The seed strengths were 1.8 U,0.5 U and 1.8 U, respectively. The prostate, prostatic urethra and anterior wall of the rectum were contoured on trans-rectal ultrasound images. PTV was outlined based on the prostate volume with no margin applied. The attempted planning goals were that V 100 (the percentage volume of the prostate receiving at least 100% of the prescription doses)= 95%, D 90 (the minimum percentage dose covering 90% of the prostate volume) ≥100%, and prostatic urethra UD 10 (the maximum percentage dose receiving by 10% of the contoured urethra) ≤150%. For the plan comparison, we also computed prostate V 150 , prostatic urethra UV 120 , rectum RV 100 , and the number of implanted seeds and needles. The significance of the differences was tested using one way analysis of variance. Results: The average V 200 in the 103 Pd, 125 I and 131 Cs plans were 28.7%, 20.9% and 19.6% (F=42.50, P=0.000); the average V 150 were 51.9%, 42.1% and 39.4% (F=26.15, P=0.000); the average UV 120 were 26.9%, 29.5% and 23.8% (F=0.37, P=0.691); and the average rectum RV 100 were 0.31 cm 3 , 0.22 cm 3 and 0.19 cm 3 (F=0.43, P=0.652). For 103 Pd, 125 I and 131 Cs, the average number of implanted seeds per cm 3 prostate were 2.02, 2.01 and 1.87 (F=1.92, P=0.154), and the average number of needles were 33.6, 32.9 and 31.6 (F=0.26,P=0.772). Conclusions: Comparing to 125 I and 103 Pd seeds used in permanent prostate brachytherapy, 131 Cs seeds has better dose homogeneity, and possible better sparing of the urethra and rectum

  7. [Esthetic analysis on immediate single-tooth implant restoration in anterior maxilla].

    Science.gov (United States)

    Li, Shao-wei; Wang, Guo-shi; Sha, Yan-zhi

    2015-10-01

    To evaluate the esthetic outcomes of immediate single-tooth implant restoration in anterior maxilla with the pink esthetic score (PES). Nine patients were treated with 9 Straumann implants by immediate single-tooth implant restoration in anterior maxilla. Assessment of PES after crown placement at 1 week (baseline) and 6 months after implantation was conducted. Statistical analysis was performed using SPSS 16.0 software package. Nine implants achieved a retention rate of 100%. PES for single-tooth implant was 10.33 ± 1.50 at 1 week and 11.44 ± 0.88 at 6 months after crown placement. The difference was significant(P=0.021). This study indicates that immediate single-tooth implant restoration in anterior maxilla is predictable. Immediate single-tooth implantation can result in good clinical esthetic results in most patients with single-tooth missing in anterior maxilla.

  8. Clinical application and validation of an iterative forward projection matching algorithm for permanent brachytherapy seed localization from conebeam-CT x-ray projections

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

    Purpose: To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from postoperatively acquired 2D conebeam-CT (CBCT) projection images. Methods: The iterative forward projection matching (IFPM) algorithm finds the 3D seed geometry that minimizes the sum of the squared intensity differences between computed projections of an initial estimate of the seed configuration and radiographic projections of the implant. In-house machined phantoms, containing arrays of 12 and 72 seeds, respectively, are used to validate this method. Also, four {sup 103}Pd postimplant patients are scanned using an ACUITY digital simulator. Three to ten x-ray images are selected from the CBCT projection set and processed to create binary seed-only images. To quantify IFPM accuracy, the reconstructed seed positions are forward projected and overlaid on the measured seed images to find the nearest-neighbor distance between measured and computed seed positions for each image pair. Also, the estimated 3D seed coordinates are compared to known seed positions in the phantom and clinically obtained VariSeed planning coordinates for the patient data. Results: For the phantom study, seed localization error is (0.58{+-}0.33) mm. For all four patient cases, the mean registration error is better than 1 mm while compared against the measured seed projections. IFPM converges in 20-28 iterations, with a computation time of about 1.9-2.8 min/iteration on a 1 GHz processor. Conclusions: The IFPM algorithm avoids the need to match corresponding seeds in each projection as required by standard back-projection methods. The authors' results demonstrate {approx}1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from the measured 2D projections. This algorithm also successfully localizes overlapping clustered and highly migrated seeds in the implant.

  9. Clinical application and validation of an iterative forward projection matching algorithm for permanent brachytherapy seed localization from conebeam-CT x-ray projections.

    Science.gov (United States)

    Pokhrel, Damodar; Murphy, Martin J; Todor, Dorin A; Weiss, Elisabeth; Williamson, Jeffrey F

    2010-09-01

    To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from postoperatively acquired 2D conebeam-CT (CBCT) projection images. The iterative forward projection matching (IFPM) algorithm finds the 3D seed geometry that minimizes the sum of the squared intensity differences between computed projections of an initial estimate of the seed configuration and radiographic projections of the implant. In-house machined phantoms, containing arrays of 12 and 72 seeds, respectively, are used to validate this method. Also, four 103Pd postimplant patients are scanned using an ACUITY digital simulator. Three to ten x-ray images are selected from the CBCT projection set and processed to create binary seed-only images. To quantify IFPM accuracy, the reconstructed seed positions are forward projected and overlaid on the measured seed images to find the nearest-neighbor distance between measured and computed seed positions for each image pair. Also, the estimated 3D seed coordinates are compared to known seed positions in the phantom and clinically obtained VariSeed planning coordinates for the patient data. For the phantom study, seed localization error is (0.58 +/- 0.33) mm. For all four patient cases, the mean registration error is better than 1 mm while compared against the measured seed projections. IFPM converges in 20-28 iterations, with a computation time of about 1.9-2.8 min/ iteration on a 1 GHz processor. The IFPM algorithm avoids the need to match corresponding seeds in each projection as required by standard back-projection methods. The authors' results demonstrate approximately 1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from the measured 2D projections. This algorithm also successfully localizes overlapping clustered and highly migrated seeds in the implant.

  10. Elders with implant overdentures: a 22-year clinical report.

    Science.gov (United States)

    Alsabeeha, Nabeel H M

    2012-09-01

    To report on the long-term survival and prosthodontic maintenance of two edentulous adults with mandibular overdentures supported by hydroxyapatite (HA)-coated implants. Mandibular implant overdentures are a successful treatment option with positive impact on the quality of life of elderly edentulous adults. Long-term survival of the implants requires continued rigorous prosthodontic maintenance. Two elderly edentulous adults with mandibular overdentures supported by 2 HA-coated implants were presented for prosthodontic rehabilitation after 22 years of placement. The implants were osseo-integrated and surviving at presentation based on accepted criteria. The mandibular implant overdentures suffered recurrent loss of retention and stability. Prosthodontic treatment involving the replacement of defective attachment systems and construction of new sets of mandibular implant overdentures opposing complete maxillary dentures is presented. The long-term survival of mandibular 2-implant overdentures requires continued prosthodontic maintenance. A conservative approach in the rehabilitation of two older edentulous adults with mandibular 2-implant overdentures was described including proper selection of attachment systems. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  11. Bar versus ball attachments for implant-supported overdentures in complete edentulism: A systematic review.

    Science.gov (United States)

    Anas El-Wegoud, Marwah; Fayyad, Ahmed; Kaddah, Amal; Nabhan, Ashraf

    2018-04-01

    Implant-supported overdenture is one of the most predictable treatment options used in complete edentulism. However, differences have been reported between bar and ball attachments used to retain overdentures in terms of patient satisfaction and prosthesis retention. The purpose of this study is to compare the effectiveness of bar and ball attachments for conventionally loaded implant-supported overdentures in completely edentulous patients to improve patient satisfaction and prosthesis retention. We conducted the review according to the Cochrane methods and following MECIR standards. We searched Cochrane Oral Health Group Trial register, Cochrane Central Register of Controlled Trials, MEDLINE, and the WHO ICTRP (March 31, 2017). Two review authors assessed trials for inclusion and risk of bias, extracted data, and checked for accuracy. We have expressed results as risk ratio or mean differences, together with their 95% confidence intervals. We included 10 trials (465 participants). After 5 y, one trial reported higher patient satisfaction when bar attachment was used (MD 1.30, 95% CI 0.20-2.40), and reported no difference between both systems in prosthesis retention (MD -0.90, 95% CI -1.90 to 0.10). Two trials reported no implant failures after 1 and 5 y in both attachments. Downgrading of evidence was based on the unclear risk of bias of included studies and the wide CI crossing the line of no effect. There is insufficient evidence to support bar or ball attachment to be used with implant-supported overdentures in completely edentulous patients to improve patient satisfaction and prosthesis retention (PROSPERO 2014:CRD42014014594). © 2017 Wiley Periodicals, Inc.

  12. 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)

  13. Maxillary implant-retained partial overdenture with Dolder bar attachment: a clinical report.

    Science.gov (United States)

    Kim, Hyeongil; Buhite, Robert J; Monaco, Edward A

    2015-03-01

    This article describes a technique for maintaining a maxillary Kennedy III partial removable dental prosthesis design in a patient who had non-restorable failing abutments by replacing the abutments with dental implants. Two implants were placed immediately after extraction of the abutment teeth in the anterior maxilla. After the implants were fully integrated, a Dolder bar attachment was fitted onto the implants. A new maxillary partial removable dental prosthesis was fabricated using the implants and the remaining natural teeth as abutments to restore function and esthetics. With the aid of dental implants, this Kennedy III maxillary removable dental prosthesis design could provide additional retention and support by promoting cross-arch stability and tissue, implant and tooth support. The patient's satisfaction was significantly increased.

  14. Zinc and phosphorus co-implantation in indium phosphide

    International Nuclear Information System (INIS)

    Yu, K.M.; Ridgway, M.C.

    1998-01-01

    Electrical activation and dopant diffusion in Zn-implanted InP after rapid thermal annealing have been investigated. For an as-implanted Zn concentration of ∼4x10 19 thinspcm -3 , only ∼7% of the implanted Zn atoms formed electrically active shallow acceptors following a 950thinsp degree C/5 s annealing cycle. The low activation was the result of rapid Zn out-diffusion emdash only ∼14% of the implanted dopant was retained after annealing. A significant enhancement in electrical activation and a reduction in Zn loss were achieved in Zn+P co-implanted samples which yielded a net hole concentration of ≤6x10 18 thinspcm -3 and >50% Zn retention. The saturation of the free hole concentration in Zn+P co-implanted samples was attributed to the formation of Zn interstitial donors and Group-V-related donor-type native defects. For comparison, Zn+Al and Zn+Al+P co-implanted samples were also examined to distinguish the relative influences of implantation-induced disorder and nonstoichiometry on electrical activation and dopant diffusion. For the given implant conditions, we found that nonstoichiometry was the dominant influence. copyright 1998 American Institute of Physics

  15. Zinc phosphate as a definitive cement for implant-supported crowns and fixed dentures

    Directory of Open Access Journals (Sweden)

    Flanagan D

    2017-11-01

    Full Text Available Dennis Flanagan Private Practice, Willimantic, CT, USA Abstract: Implant-supported dental prostheses can be retained by a screw or cement. Implant-supported fixed partial dentures have a passive fit. A passive fit means there is an internal gap between the abutment surface and the intaglio of the retainer to insure that there is no lateral pressure on the supporting implants or friction upon seating of the prosthesis. This gap is filled with cement for retention of the prosthesis. Any lateral pressure may cause marginal bone loss or periimplantitis. Also, there is usually a microscopic gap at the margin of a crown retainer that exposes the cement to oral fluids. The solubility of zinc phosphate (ZOP cement is a definite liability due to the risk for cement dissolution. In fixed prostheses, the dissolution of the cement of one or more retainers would cause a transfer of the occlusal load to the retained unit(s. The resulting rotation and lifting of the cement-retained implants from occlusal and parafunctional loads could cause loss of osseointegration of the abutment-retained implant(s. ZOP cement may not be indicated for implant-supported fixed partial dentures or splints. Cement dissolution in single unit probably only involves re-cementation, if the patient does not swallow or aspirate the crown. Keywords: passive fit, retention, film thickness, fixed, marginal gap 

  16. Clinical Significance of Accounting for Tissue Heterogeneity in Permanent Breast Seed Implant Brachytherapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, Shahram [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Fleury, Emmanuelle [Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Lai, Priscilla [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Merino, Tomas [Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Radiotherapy Unit, School of Medicine, Departamento de Hemato-oncologia, Pontificia Universidad Católica de Chile, Santiago (Chile); Lechtman, Eli [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Kiss, Alex [Sunnybrook Research Institute, Toronto, Ontario (Canada); McCann, Claire [Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Pignol, Jean-Philippe, E-mail: j.p.pignol@erasmusmc.nl [Medical Biophysics Department, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, Ontario (Canada); Radiation Oncology Department, Erasmus Medical Center, Cancer Institute, Rotterdam (Netherlands)

    2016-03-15

    Purpose: The inhomogeneity correction factor (ICF) method provides heterogeneity correction for the fast calculation TG43 formalism in seed brachytherapy. This study compared ICF-corrected plans to their standard TG43 counterparts, looking at their capacity to assess inadequate coverage and/or risk of any skin toxicities for patients who received permanent breast seed implant (PBSI). Methods and Materials: Two-month postimplant computed tomography scans and plans of 140 PBSI patients were used to calculate dose distributions by using the TG43 and the ICF methods. Multiple dose-volume histogram (DVH) parameters of clinical target volume (CTV) and skin were extracted and compared for both ICF and TG43 dose distributions. Short-term (desquamation and erythema) and long-term (telangiectasia) skin toxicity data were available on 125 and 110 of the patients, respectively, at the time of the study. The predictive value of each DVH parameter of skin was evaluated using the area under the receiver operating characteristic (ROC) curve for each toxicity endpoint. Results: Dose-volume histogram parameters of CTV, calculated using the ICF method, showed an overall decrease compared to TG43, whereas those of skin showed an increase, confirming previously reported findings of the impact of heterogeneity with low-energy sources. The ICF methodology enabled us to distinguish patients for whom the CTV V{sub 100} and V{sub 90} are up to 19% lower compared to TG43, which could present a risk of recurrence not detected when heterogeneity are not accounted for. The ICF method also led to an increase in the prediction of desquamation, erythema, and telangiectasia for 91% of skin DVH parameters studied. Conclusions: The ICF methodology has the advantage of distinguishing any inadequate dose coverage of CTV due to breast heterogeneity, which can be missed by TG43. Use of ICF correction also led to an increase in prediction accuracy of skin toxicities in most cases.

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  19. Permanent LDR implants in treatment of prostate cancer

    International Nuclear Information System (INIS)

    Skowronek, J.; Kanikowski, M.; Chichel, A.; Zwierzchowski, G.

    2009-01-01

    Low-dose rate brachytherapy (LDR-BT) is a radiation method known for several years in the treatment of localized prostate cancer. The main idea of this method is to implant small radioactive seeds directly into the prostate gland. LDR brachytherapy is applied as a monotherapy and also used along with external beam radiation therapy (EBRT) as a boost. In most cases it is used as a sole radical treatment modality, but not as a palliative treatment. The application of permanent seed implants is a curative treatment alternative in patients with organ- confined cancer, without extracapsular extension of the tumour. This technique is particularly popular in the United States. In Europe, however, high-dose rate brachytherapy (HDR-BT) is more popular in early-stage prostate cancer treatment (as a boost). The aim of this publication is to describe methods, indications, complications and selected results of prostate cancer LDR brachytherapy. (authors)

  20. 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 ...

  1. Structural changes of cotton seeds due to fast neurons-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Osiris, W G [Biophysics Department, Faculty of Science, Cairo University, Giza, (Egypt)

    1997-12-31

    The effect of irradiation with different fast neutron fluences in the range 10{sub 5}- 10{sub 8} n/cm{sup 2} were studied on one egyptian cotton seeds (Dandara, Giza 31). Both pre-and post-irradiated seeds were implanted and the effects of fast neutrons on the first generation were investigated through the use of: X-ray fluorescence analysis, infrared spectral,combustion technique, analysis as well as scanning electron microscopy. The changes in cellulose and heme cellulose contents in the seeds relative to the unirradiated one were also detected. From the obtained results,it was found that significant structural changes are indicated which may be attributed to the variation in the internal mechanisms that occurred by the radiation effect on thr structure of seeds. In conclusion, irradiation with fast neutrons may cause genetic changes in seeds. 4 figs., 5 tabs.

  2. Use of an Implant O-Ring Attachment for the Tooth Supported Mandibular Overdenture: A Clinical Report

    Science.gov (United States)

    Guttal, Satyabodh S.; Tavargeri, Anand K.; Nadiger, Ramesh K.; Thakur, Srinath L.

    2011-01-01

    Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. The same design principles holds true for both implant-retained and tooth-retained methods of anchoring the bar and stud attachment. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. When few firm teeth still remain in a compromised dentition, preservation of these teeth for overdentures can improve retention and stability. The authors present a clinical report of a patient treated with a mandibular tooth-borne overdenture with bar and O-ring attachment. A splinted bar supported the prosthesis and an O-ring retained the denture. PMID:21769276

  3. Use of an implant o-ring attachment for the tooth supported mandibular overdenture: a clinical report.

    Science.gov (United States)

    Guttal, Satyabodh S; Tavargeri, Anand K; Nadiger, Ramesh K; Thakur, Srinath L

    2011-07-01

    Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. The same design principles holds true for both implant-retained and tooth-retained methods of anchoring the bar and stud attachment. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. When few firm teeth still remain in a compromised dentition, preservation of these teeth for overdentures can improve retention and stability. The authors present a clinical report of a patient treated with a mandibular tooth-borne overdenture with bar and O-ring attachment. A splinted bar supported the prosthesis and an O-ring retained the denture.

  4. Demonstration of a forward iterative method to reconstruct brachytherapy seed configurations from x-ray projections

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Martin J; Todor, Dorin A [Department of Radiation Oncology, Virginia Commonwealth University, Richmond VA 23298 (United States)

    2005-06-07

    By monitoring brachytherapy seed placement and determining the actual configuration of the seeds in vivo, one can optimize the treatment plan during the process of implantation. Two or more radiographic images from different viewpoints can in principle allow one to reconstruct the configuration of implanted seeds uniquely. However, the reconstruction problem is complicated by several factors: (1) the seeds can overlap and cluster in the images; (2) the images can have distortion that varies with viewpoint when a C-arm fluoroscope is used; (3) there can be uncertainty in the imaging viewpoints; (4) the angular separation of the imaging viewpoints can be small owing to physical space constraints; (5) there can be inconsistency in the number of seeds detected in the images; and (6) the patient can move while being imaged. We propose and conceptually demonstrate a novel reconstruction method that handles all of these complications and uncertainties in a unified process. The method represents the three-dimensional seed and camera configurations as parametrized models that are adjusted iteratively to conform to the observed radiographic images. The morphed model seed configuration that best reproduces the appearance of the seeds in the radiographs is the best estimate of the actual seed configuration. All of the information needed to establish both the seed configuration and the camera model is derived from the seed images without resort to external calibration fixtures. Furthermore, by comparing overall image content rather than individual seed coordinates, the process avoids the need to establish correspondence between seed identities in the several images. The method has been shown to work robustly in simulation tests that simultaneously allow for unknown individual seed positions, uncertainties in the imaging viewpoints and variable image distortion.

  5. Effect of processing on nutrients and fatty acid composition of garden cress (Lepidium sativum) seeds.

    Science.gov (United States)

    Jain, Tanu; Grover, Kiran; Kaur, Gurpreet

    2016-12-15

    Garden cress seeds were undergone for different processing methods and analyzed for its nutritional composition. Effect of processing on nutrient retention was evaluated to attain the best processed form of seeds with maximum amount of nutrients. Soaking improved protein and ash by 2.10 and 2.48 percent respectively. Boiling improved fat and fibre by 1.66 and 8.32 percent respectively. Maximum retention of iron and zinc was found with roasting. It also improved calcium by 3.18 percent. Percent ionizable iron and bioavailability was found maximum with boiling (13.59 and 6.88% respectively). In vitro starch and protein digestibility were found maximum on boiling (57.98 and 32.39% respectively) with a decrease of 9.65 and 14.13 percent in phytin phosphorus and oxalate respectively. Amino acids and fatty acids were decreased with heat treatment and maximum retention was found with soaking. Overall improvement in nutrient composition and maximum nutrient retention was found with boiling method. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Evaluating the potential for weed seed dispersal based on waterfowl consumption and seed viability.

    Science.gov (United States)

    Farmer, Jaime A; Webb, Elisabeth B; Pierce, Robert A; Bradley, Kevin W

    2017-12-01

    Migratory waterfowl have often been implicated in the movement of troublesome agronomic and wetland weed species. However, minimal research has been conducted to investigate the dispersal of agronomically important weed species by waterfowl. The two objectives for this project were to determine what weed species are being consumed by ducks and snow geese, and to determine the recovery rate and viability of 13 agronomic weed species after passage through a duck's digestive system. Seed recovered from digestive tracts of 526 ducks and geese harvested during a 2-year field study had 35 020 plants emerge. A greater variety of plant species emerged from ducks each year (47 and 31 species) compared to geese (11 and 3 species). Viable seed from 11 of 13 weed species fed to ducks in a controlled feeding study were recovered. Viability rate and gut retention times indicated potential dispersal up to 2900 km from the source depending on seed characteristics and variability in waterfowl dispersal distances. Study results confirm that waterfowl are consuming seeds from a variety of agronomically important weed species, including Palmer amaranth, which can remain viable after passage through digestive tracts and have potential to be dispersed over long distances by waterfowl. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Microstructure evolution in carbon-ion implanted sapphire

    International Nuclear Information System (INIS)

    Orwa, J. O.; McCallum, J. C.; Jamieson, D. N.; Prawer, S.; Peng, J. L.; Rubanov, S.

    2010-01-01

    Carbon ions of MeV energy were implanted into sapphire to fluences of 1x10 17 or 2x10 17 cm -2 and thermally annealed in forming gas (4% H in Ar) for 1 h. Secondary ion mass spectroscopy results obtained from the lower dose implant showed retention of implanted carbon and accumulation of H near the end of range in the C implanted and annealed sample. Three distinct regions were identified by transmission electron microscopy of the implanted region in the higher dose implant. First, in the near surface region, was a low damage region (L 1 ) composed of crystalline sapphire and a high density of plateletlike defects. Underneath this was a thin, highly damaged and amorphized region (L 2 ) near the end of range in which a mixture of i-carbon and nanodiamond phases are present. Finally, there was a pristine, undamaged sapphire region (L 3 ) beyond the end of range. In the annealed sample some evidence of the presence of diamond nanoclusters was found deep within the implanted layer near the projected range of the C ions. These results are compared with our previous work on carbon implanted quartz in which nanodiamond phases were formed only a few tens of nanometers from the surface, a considerable distance from the projected range of the ions, suggesting that significant out diffusion of the implanted carbon had occurred.

  8. Post-operative hemimaxillectomy rehabilitation using prostheses supported by zygoma implants and remaining natural teeth

    Directory of Open Access Journals (Sweden)

    Xing Zhou Qu

    Full Text Available OBJECTIVES: This study aimed to evaluate the stability of prostheses supported by zygoma implants and remaining teeth for subjects who had undergone hemi-maxillectomy. METHODS: Ten patients were included in the study. Oral rehabilitation was performed using a temporary prosthesis that was supported by remaining teeth for the first three months. Then, a zygoma implant was placed to provide support for a final prosthesis in addition to the remaining teeth. Each prosthesis was tailor-made according to biomechanical three-dimensional finite element analysis results. The patients were assessed using the prosthesis functioning scale of the Memorial Sloan-Kettering Cancer Center. In addition, retention and bite force were recorded for both the temporary prosthesis and the final prosthesis. RESULTS: The mean bite force of the prosthetic first molar was increased to 69.2 N. The mean retentive force increased to 13.5 N after zygoma implant insertion. The bite force on the prosthetic first molar was improved to 229.3 N. CONCLUSION: Bite force increased significantly with the support of a zygoma implant. The use of zygoma implants in the restoration of maxillary defects improved functional outcome and patient satisfaction.

  9. 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.

  10. Influence of ion implanted helium on deuterium trapping in Kh18N10T stainless steel

    International Nuclear Information System (INIS)

    Tolstolutskaya, G.D.; Ruzhitskij, V.V.; Kopanets, I.E.

    2004-01-01

    The results are presented on evolution of distribution profiles and helium and deuterium thermal desorption ion implanted in steel 18Cr10NiTi. Accumulation, trapping, retention and microstructure evolution are studied; effect helium and hydrogen simultaneous implantation on these processes is also studied

  11. Opportunities and challenges for harvest weed seed control in global cropping systems.

    Science.gov (United States)

    Walsh, Michael J; Broster, John C; Schwartz-Lazaro, Lauren M; Norsworthy, Jason K; Davis, Adam S; Tidemann, Breanne D; Beckie, Hugh J; Lyon, Drew J; Soni, Neeta; Neve, Paul; Bagavathiannan, Muthukumar V

    2017-11-28

    The opportunity to target weed seeds during grain harvest was established many decades ago following the introduction of mechanical harvesting and the recognition of high weed-seed retention levels at crop maturity; however, this opportunity remained largely neglected until more recently. The introduction and adoption of harvest weed seed control (HWSC) systems in Australia has been in response to widespread occurrence of herbicide-resistant weed populations. With diminishing herbicide resources and the need to maintain highly productive reduced tillage and stubble-retention practices, growers began to develop systems that targeted weed seeds during crop harvest. Research and development efforts over the past two decades have established the efficacy of HWSC systems in Australian cropping systems, where widespread adoption is now occurring. With similarly dramatic herbicide resistance issues now present across many of the world's cropping regions, it is timely for HWSC systems to be considered for inclusion in weed-management programs in these areas. This review describes HWSC systems and establishing the potential for this approach to weed control in several cropping regions. As observed in Australia, the inclusion of HWSC systems can reduce weed populations substantially reducing the potential for weed adaptation and resistance evolution. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Fuel retention under elevated wall temperature in KSTAR with a carbon wall

    Science.gov (United States)

    Cao, B.; Hong, S. H.

    2018-03-01

    The fuel retention during KSTAR discharges with elevated wall temperature (150 °C) has been studied by using the method of global particle balance. The results show that the elevated wall temperature could reduce the dynamic retention via implantation and absorption, especially for the short pulse shots with large injected fuel particles. There is no signature changing of long-term retention, which related to co-deposition, under elevated wall temperature. For soft-landing shots (normal shots), the exhausted fuel particles during discharges is larger with elevated wall temperature than without, but the exhausted particles after discharges within 90 s looks similar. The outgassing particles because of disruption could be exhausted within 15 s.

  13. [Effect of image fusion technology of radioactive particles implantation before and after the planning target and dosimetry].

    Science.gov (United States)

    Jiang, Y L; Yu, J P; Sun, H T; Guo, F X; Ji, Z; Fan, J H; Zhang, L J; Li, X; Wang, J J

    2017-08-01

    Objective: To compare the post-implant target volumes and dosimetric evaluation with pre-plan, the gross tumor volume(GTV) by CT image fusion-based and the manual delineation of target volume in CT guided radioactive seeds implantation. Methods: A total of 10 patients treated under CT-guidance (125)I seed implantation during March 2016 to April 2016 were analyzed in Peking University Third Hospital.All patients underwent pre-operative CT simulation, pre-operative planning, implantation seeds, CT scanning after seed implantation and dosimetric evaluation of GTV.In every patient, post-implant target volumes were delineated by both two methods, and were divided into two groups. Group 1: image fusion pre-implantation simulation and post-operative CT image, then the contours of GTV were automatically performed by brachytherapy treatment planning system; Group 2: the contouring of the GTV on post-operative CT image were performed manually by three senior radiation oncologists independently. The average of three data was sets. Statistical analyses were performed using SPSS software, version 3.2.0. The paired t -test was used to compare the target volumes and D(90) parameters in two modality. Results: In Group 1, average volume of GTV in post-operation group was 12-167(73±56) cm(3). D(90) was 101-153 (142±19)Gy. In Group 2, they were 14-186(80±58)cm(3) and 96-146(122±16) Gy respectively. In both target volumes and D(90), there was no statistical difference between pre-operation and post-operation in Group 1.The D(90) was slightly lower than that of pre-plan group, but there was no statistical difference ( P =0.142); in Group 2, between pre-operation and post-operation group, there was a significant statistical difference in the GTV ( P =0.002). The difference of D(90) was similarly ( P manual delineation of target volume by maximum reduce the interference from artificial factor and metal artifacts. Further work and more cases are required in the future.

  14. 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)

  15. Two-Implant-Supported Mandibular Overdentures: Do Clinical Denture Quality and Inter-Implant Distance Affect Patient Satisfaction?

    Science.gov (United States)

    Alfadda, Sara A; Al Amri, Mohammad D; Al-Ohali, Amal; Al-Hakami, Arwa; Al-Madhi, Noura

    To investigate the following three null hypotheses in patients rehabilitated with a mandibular overdenture supported by two unsplinted implants: (1) patient satisfaction is not related to the clinical quality of the dentures; (2) inter-implant distance (IID) has no effect on the clinical quality of the dentures; and (3) IID does not influence patient satisfaction. Forty edentulous patients who were rehabilitated with a two-implant-supported mandibular overdenture participated in the study. Independent investigators evaluated the dentures on the basis of five clinical criteria using the validated Denture Quality Evaluation Form, and the patients completed the validated Denture Satisfaction Scale. Irreversible hydrocolloid impressions of the mandible were made and poured immediately in die stone. The IID was measured by adapting an orthodontic wire to the mandibular alveolar ridge crest, extending from the center of one implant to the center of the other. Spearman correlation analyses were used to identify possible correlations, with a significance level set at P overdenture and of the maxillary conventional complete denture was significantly related to satisfaction (r = 0.389 and r = 0.44, respectively). Significant associations were found between the mandibular stability items and satisfaction with both maxillary and mandibular dentures. The stability of the maxillary denture was significantly associated with patient satisfaction with mandibular denture retention, stability, and comfort. None of the 12 denture satisfaction items were significantly associated with IID. Similarly, IID did not have an effect on the quality of either denture in terms of retention, stability, or occlusion. Denture stability was the feature that had the most influence on patient satisfaction with the mandibular overdenture and with the maxillary conventional denture. IID had no effect on the clinical quality of either denture and did not influence patient satisfaction.

  16. SU-E-J-214: MR Protocol Development to Visualize Sirius MRI Markers in Prostate Brachytherapy Patients for MR-Based Post-Implant Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lim, T; Wang, J; Frank, S; Stafford, R; Bruno, T; Bathala, T; Mahmood, U; Pugh, T; Ibbott, G; Kudchadker, R [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: The current CT-based post-implant dosimetry allows precise seed localization but limited anatomical delineation. Switching to MR-based post-implant dosimetry is confounded by imprecise seed localization. One approach is to place positive-contrast markers (Sirius) adjacent to the negative-contrast seeds. This patient study aims to assess the utility of a 3D fast spoiled gradient-recalled echo (FSPGR) sequence to visualize Sirius markers for post-implant dosimetry. Methods: MRI images were acquired in prostate implant patients (n=10) on Day 0 (day-of-implant) and Day 30. The post-implant MR protocol consisted of 3D T2-weighted fast-spin-echo (FSE), T2-weighted 2D-FSE (axial) and T1-weighted 2D-FSE (axial/sagittal/coronal). We incorporated a 3D-FSPGR sequence into the post-implant MR protocol to visualize the Sirius markers. Patients were scanned with different number-of-excitations (6, 8, 10), field-of-view (10cm, 14cm, 18cm), slice thickness (1mm, 0.8mm), flip angle (14 degrees, 20 degrees), bandwidth (122.070 Hz/pixel, 325.508 Hz/pixel, 390.625 Hz/pixel), phase encoding steps (160, 192, 224, 256), frequency-encoding direction (right/left, anterior/posterior), echo-time type (minimum-full, out-of-phase), field strength (1.5T, 3T), contrast (with, without), scanner vendor (Siemens, GE), coil (endorectal-coil only, endorectal-and-torso-coil, torsocoil only), endorectal-coil filling (30cc, 50cc) and endorectal-coil filling type (air, perfluorocarbon [PFC]). For post-implant dosimetric evaluation with greater anatomical detail, 3D-FSE images were fused with 3D-FSPGR images. For comparison with CT-based post-implant dosimetry, CT images were fused with 3D-FSPGR images. Results: The 3D-FSPGR sequence facilitated visualization of markers in patients. Marker visualization helped distinguish signal voids as seeds versus needle tracks for more definitive MR-based post-implant dosimetry. On the CT-MR fused images, the distance between the seed on CT to MR images was 3

  17. SU-E-J-214: MR Protocol Development to Visualize Sirius MRI Markers in Prostate Brachytherapy Patients for MR-Based Post-Implant Dosimetry

    International Nuclear Information System (INIS)

    Lim, T; Wang, J; Frank, S; Stafford, R; Bruno, T; Bathala, T; Mahmood, U; Pugh, T; Ibbott, G; Kudchadker, R

    2015-01-01

    Purpose: The current CT-based post-implant dosimetry allows precise seed localization but limited anatomical delineation. Switching to MR-based post-implant dosimetry is confounded by imprecise seed localization. One approach is to place positive-contrast markers (Sirius) adjacent to the negative-contrast seeds. This patient study aims to assess the utility of a 3D fast spoiled gradient-recalled echo (FSPGR) sequence to visualize Sirius markers for post-implant dosimetry. Methods: MRI images were acquired in prostate implant patients (n=10) on Day 0 (day-of-implant) and Day 30. The post-implant MR protocol consisted of 3D T2-weighted fast-spin-echo (FSE), T2-weighted 2D-FSE (axial) and T1-weighted 2D-FSE (axial/sagittal/coronal). We incorporated a 3D-FSPGR sequence into the post-implant MR protocol to visualize the Sirius markers. Patients were scanned with different number-of-excitations (6, 8, 10), field-of-view (10cm, 14cm, 18cm), slice thickness (1mm, 0.8mm), flip angle (14 degrees, 20 degrees), bandwidth (122.070 Hz/pixel, 325.508 Hz/pixel, 390.625 Hz/pixel), phase encoding steps (160, 192, 224, 256), frequency-encoding direction (right/left, anterior/posterior), echo-time type (minimum-full, out-of-phase), field strength (1.5T, 3T), contrast (with, without), scanner vendor (Siemens, GE), coil (endorectal-coil only, endorectal-and-torso-coil, torsocoil only), endorectal-coil filling (30cc, 50cc) and endorectal-coil filling type (air, perfluorocarbon [PFC]). For post-implant dosimetric evaluation with greater anatomical detail, 3D-FSE images were fused with 3D-FSPGR images. For comparison with CT-based post-implant dosimetry, CT images were fused with 3D-FSPGR images. Results: The 3D-FSPGR sequence facilitated visualization of markers in patients. Marker visualization helped distinguish signal voids as seeds versus needle tracks for more definitive MR-based post-implant dosimetry. On the CT-MR fused images, the distance between the seed on CT to MR images was 3

  18. Use of the frontal process of the maxillary bone for implant placement to retain a nasal prosthesis: a clinical report.

    Science.gov (United States)

    Proussaefs, Periklis

    2004-01-01

    Implant placement to provide support and retention for nasal prostheses has been described in the literature. The anatomic sites that have been utilized for implant placement are the nasal bones, the premaxillary area through the nasal fossae, and the anterior wall of the frontal sinus. In the patient described, after a presurgical computerized tomography scan to determine adequacy of bone volume, 1 conventional threaded hydroxyapatite-coated root-form implant, created for intraoral use, was placed in the frontal process of the maxillary bone and 2 additional conventional implants were placed in the premaxillary area through the nasal fossa. Six months after implant placement, second-stage surgery was completed. A single bar connecting the 3 implants was fabricated. The removable nasal prosthesis was retained on the bar with 2 clips. An examination 1 year postsurgery revealed no clinical signs of pathosis. Long-term clinical follow-up of this case should continue and a sufficient number of additional cases should be investigated before use of the frontal process of the maxillary bone for implant retention can be recommended on a routine basis.

  19. Cytological effect of nitrogen ion implantation into Stevia

    International Nuclear Information System (INIS)

    Shen Mei; Wang Cailian; Chen Qiufang; Lu Ting; Shu Shizhen

    1997-01-01

    Dry seeds of Stevia were implanted by 35∼150 keV nitrogen ion with various doses. The cytological effect on M 1 was studied. The results showed that nitrogen ion beam was able to induce variation on chromosome structure in root tip cells. The rate of cells with chromosome aberration was increased with the increased with the increase of ion beam energy and dose. However, there was no significant linear regression relationship between ion dose and aberration rate. The cytological effect of nitrogen ion implantation was lower than that of γ-rays

  20. Method of electroplating a conversion electron emitting source on implant

    Science.gov (United States)

    Srivastava, Suresh C [Setauket, NY; Gonzales, Gilbert R [New York, NY; Adzic, Radoslav [East Setauket, NY; Meinken, George E [Middle Island, NY

    2012-02-14

    Methods for preparing an implant coated with a conversion electron emitting source (CEES) are disclosed. The typical method includes cleaning the surface of the implant; placing the implant in an activating solution comprising hydrochloric acid to activate the surface; reducing the surface by H.sub.2 evolution in H.sub.2SO.sub.4 solution; and placing the implant in an electroplating solution that includes ions of the CEES, HCl, H.sub.2SO.sub.4, and resorcinol, gelatin, or a combination thereof. Alternatively, before tin plating, a seed layer is formed on the surface. The electroplated CEES coating can be further protected and stabilized by annealing in a heated oven, by passivation, or by being covered with a protective film. The invention also relates to a holding device for holding an implant, wherein the device selectively prevents electrodeposition on the portions of the implant contacting the device.

  1. Remedy for Repeated Implant Retained Denture Fracture-A Challenging Case Report

    Science.gov (United States)

    Reddy M, Ramu; Metta, Kiran Kumar; Charry N, Sudheer; B, Chittaranjan

    2014-01-01

    The most common site of fracture in a maxillary or a mandibular complete denture is along an anteroposterior line that coincides with the labial notch in in the denture which used to provide the frenum relief. Osseointegrated implants have been a boon to the patients who are completelly edentulous and are not satisfied with the conventional removable complete denture approach.Implant supported dentures have proven to provide superior retention and support for removable complete dentures. Nevertheless, fracture of the denture bases is a common complication of implant-supported mandibular overlay dentures,ecspecially when the artificial denture is opposing natural dentition. This article describes and illustrates a method of reinforcing implant-supported mandibular overdentures to overcome this problem. PMID:25584333

  2. Observations of suppressed retention and blistering for tungsten exposed to deuterium-helium mixture plasmas

    International Nuclear Information System (INIS)

    Miyamoto, M.; Morito, S.; Ono, K.; Nishijima, D.; Doerner, R.P.; Baldwin, M.J.; Hanna, J.; Ueda, Y.; Kurishita, H.

    2009-01-01

    Blister formation and D retention in W have been investigated for low energy (∼55 ± 15 eV), high flux (∼10 22 m -2 s -1 ), high fluence (≤4.5 x 10 26 m -2 ) ion bombardment at moderate temperature (∼573 K) in mixed species D+He plasmas in the linear divertor plasma simulator PISCES-A. The amount of D retained in W is found to decrease significantly when compared with that in W exposed to pure D plasmas, as measured with high resolution thermal desorption spectroscopy. Scanning electron microscopy observations reveal the suppression of the blisters, a surface feature known to drive up retention, in the D + He mixture plasma exposed W samples. Reduced D retention is accompanied by the formation of nano-sized high density He bubbles in the near surface, observed with a transmission electron microscope (TEM). It is believed that the nano-bubbles act as a diffusion barrier to implanted D atoms and consequently reduce the amount of uptake in the W material. This newly observed effect implies that current predictions of D retention in W, in actual fusion devices, may be overestimated, since there will be He ash in fusion plasma. Toughness enhanced, fine-grained (grain size of ∼1 μm) W-TiC samples, exposed to pure D plasma conditions, also show little or no evidence of blistering. The measured D retention in the W-TiC samples was approximately 1 x 10 19 D m -2 corresponding to about 2 x 10 -7 of the implanted D fluence, and is very low compared with the retention in pure stress relieved W, which exhibited surface blisters and had a D retention of about 1 x 10 21 D m -2 .

  3. Gene expression profiling of the green seed problem in Soybean

    NARCIS (Netherlands)

    Nogueira Teixeira, Renake; Ligterink, Wilco; B. França-Neto, de José; Hilhorst, H.W.M.; Silva, da E.A.A.

    2016-01-01

    Background: Due to the climate change of the past few decades, some agricultural areas in the world are now experiencing new climatic extremes. For soybean, high temperatures and drought stress can potentially lead to the "green seed problem", which is characterized by chlorophyll retention in

  4. Implant R100 Predicts Rectal Bleeding in Prostate Cancer Patients Treated with IG-IMRT to 45 Gy and Pd-103 Implant

    OpenAIRE

    Matthew Packard; Vladimir Valakh; Russell Fuhrer

    2014-01-01

    Purpose. To define factors associated with rectal bleeding in patients treated with IG-IMRT followed by Pd-103 seed implant. Methods and Materials. We retrospectively reviewed 61 prostate adenocarcinoma patients from 2002 to 2008. The majority (85.2%) were of NCCN intermediate risk category. All received IG-IMRT to the prostate and seminal vesicles followed by Pd-103 implant delivering a mean D90 of 100.7 Gy. Six patients received 45 Gy to the pelvic nodes and 10 received androgen deprivation...

  5. Implantation of a biodegradable rectum balloon implant: Tips, Tricks and Pitfalls

    Directory of Open Access Journals (Sweden)

    Ben G. L. Vanneste

    Full Text Available ABSTRACT Introduction: A rectum balloon implant (RBI is a new device to spare rectal structures during prostate cancer radiotherapy. The theoretical advantages of a RBI are to reduce the high radiation dose to the anterior rectum wall, the possibility of a post-implant correction, and their predetermined shape with consequent predictable position. Objective: To describe, step-by-step, our mini-invasive technique for hands-free transperineal implantation of a RBI before start of radiotherapy treatment. Materials and Methods: We provide step-by-step instructions for optimization of the transperineal implantation procedure performed by urologists and/or radiation oncologists experienced with prostate brachytherapy and the use of the real-time bi-plane transrectal ultrasonography (TRUS probe. A RBI was performed in 15 patients with localised prostate cancer. Perioperative side-effects were reported. Results: We provide ‘tips and tricks’ for optimizing the procedure and proper positioning of the RBI. Please watch the animation, see video in https://vimeo.com/205852376/789df4fae4. The side-effects included mild discomfort to slight pain at the perineal region in 8 out of 15 patients. Seven patients (47% had no complaints at all. Two patients developed redness of the skin, where prompt antibiotic regimen was started with no further sequelae. One patient revealed a temporary urine retention, which resolved in a few hours following conservative treatment. Further no perioperative complications occurred. Conclusion: This paper describes in detail the implantation procedure for an RBI. It is a feasible, safe and very well-tolerated procedure.

  6. A simple ion implanter for material modifications in agriculture and gemmology

    Science.gov (United States)

    Singkarat, S.; Wijaikhum, A.; Suwannakachorn, D.; Tippawan, U.; Intarasiri, S.; Bootkul, D.; Phanchaisri, B.; Techarung, J.; Rhodes, M. W.; Suwankosum, R.; Rattanarin, S.; Yu, L. D.

    2015-12-01

    In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X-Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

  7. A simple ion implanter for material modifications in agriculture and gemmology

    International Nuclear Information System (INIS)

    Singkarat, S.; Wijaikhum, A.; Suwannakachorn, D.; Tippawan, U.; Intarasiri, S.; Bootkul, D.; Phanchaisri, B.; Techarung, J.; Rhodes, M.W.; Suwankosum, R.; Rattanarin, S.; Yu, L.D.

    2015-01-01

    In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X–Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

  8. A simple ion implanter for material modifications in agriculture and gemmology

    Energy Technology Data Exchange (ETDEWEB)

    Singkarat, S. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Wijaikhum, A. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Suwannakachorn, D.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Intarasiri, S. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Bootkul, D. [Department of General Science, Faculty of Science, Srinakharinwirot University, Bangkok 10110 (Thailand); Phanchaisri, B.; Techarung, J. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Rhodes, M.W.; Suwankosum, R.; Rattanarin, S. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2015-12-15

    In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X–Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

  9. Application of ion implantation in stevia breeding

    International Nuclear Information System (INIS)

    Wang Cailian; Chen Qiufang; Jin Wei; Lu Ting; Shu Shizhen

    1999-08-01

    Dry seed of stevia were implanted with 60-100 keV nitrogen ion and 75 keV carbon ion of various doses, and the effects of the composition and yield of stevioside were studied. The results showed that ion beam could induce variation in total stevioside yield and the composition of the plant. The best treatment was 75 keV nitrogen ion with 5 x 10 14 N + /cm 2 , the stevioside yield and Rebaudioside A (R-A) content were increased by 4.74% and 14.08% respectively. The effects induced by implantation of carbon ion were higher than those induced by implantation of nitrogen ion. Effects of Feng 1 x Ri Yuan and Ri Yuan x Feng 2 are higher than those of Ji Ning and Feng 2 . Seven mutation lines were selected from the mutation progenies. The stevioside composition of these lines were previously improved. The results suggest a potential application of ion implantation in stevia breeding

  10. THE THERAPEUTIC USE OF RADIOACTIVE GOLD SEEDS IN NEOPLASMS

    Energy Technology Data Exchange (ETDEWEB)

    Lachance, Paul; Vallee, A. F.

    1963-06-15

    A method and the apparatus for the treatment of neoplasms with Au/sup 198/ seeds are described. The introducer or gun is loaded with a magazine or cartridge containing 15 radioactive gold grains and then irradiated. The grains are cylinders made of gold encased in Pt with measurements of: length, 2.1 mm; diameter, 0.4 mm; weight, 25 mgm; platinum casing, 0.2 mm. The seeds are ready for use 7 to 10 days after irradiation or when gamma activity is around 3 to 4.5 mC per seed. A permanent implant gives to the tumor an approximate dose of 6000- 7000 r in 4 to 5 days. The effectiveness and advantages of the method are also discussed. (P.C.H.)

  11. Hydrogen retention in ion irradiated steels

    International Nuclear Information System (INIS)

    Hunn, J.D.; Lewis, M.B.; Lee, E.H.

    1998-01-01

    In the future 1--5 MW Spallation Neutron Source, target radiation damage will be accompanied by high levels of hydrogen and helium transmutation products. The authors have recently carried out investigations using simultaneous Fe/He,H multiple-ion implantations into 316 LN stainless steel between 50 and 350 C to simulate the type of radiation damage expected in spallation neutron sources. Hydrogen and helium were injected at appropriate energy and rate, while displacement damage was introduced by nuclear stopping of 3.5 MeV Fe + , 1 microm below the surface. Nanoindentation measurements showed a cumulative increase in hardness as a result of hydrogen and helium injection over and above the hardness increase due to the displacement damage alone. TEM investigation indicated the presence of small bubbles of the injected gases in the irradiated area. In the current experiment, the retention of hydrogen in irradiated steel was studied in order to better understand its contribution to the observed hardening. To achieve this, the deuterium isotope ( 2 H) was injected in place of natural hydrogen ( 1 H) during the implantation. Trapped deuterium was then profiled, at room temperature, using the high cross-section nuclear resonance reaction with 3 He. Results showed a surprisingly high concentration of deuterium to be retained in the irradiated steel at low temperature, especially in the presence of helium. There is indication that hydrogen retention at spallation neutron source relevant target temperatures may reach as high as 10%

  12. Synergistic effects of iodine and silver ions co-implanted in 6H–SiC

    International Nuclear Information System (INIS)

    Kuhudzai, R.J.; Malherbe, J.B.; Hlatshwayo, T.T.; Berg, N.G. van der; Devaraj, A.; Zhu, Z.; Nandasiri, M.

    2015-01-01

    Motivated by the aim of understanding the release of fission products through the SiC coating of fuel kernels in modern high temperature nuclear reactors, a fundamental investigation is conducted to understand the synergistic effects of implanted silver (Ag) and iodine (I) in 6H–SiC. The implantation of the individual species, as well as the co-implantation of 360 keV ions of I and Ag at room temperature in 6H–SiC and their subsequent annealing behaviour has been investigated by Secondary Ion Mass Spectrometry (SIMS), Atom Probe Tomography (APT) and X-ray Photoelectron Spectroscopy (XPS). SIMS and APT measurements indicated the presence of Ag in the co-implanted samples after annealing at 1500 °C for 30 h in sharp contrast to the samples implanted with Ag only. In samples implanted with Ag only, complete loss of the implanted Ag was observed. However, for I only implanted samples, some iodine was retained. APT of annealed co-implanted 6H–SiC showed clear spatial association of Ag and I clusters in SiC, which can be attributed to the observed I assisted retention of Ag after annealing. Such detailed studies will be necessary to identify the fundamental mechanism of fission products migration through SiC coatings. - Highlights: • Co-implantation of Ag and I ions in 6H–SiC was performed. • Clear spatial association of Ag and I clusters observed after annealing. • Complete loss of Ag after high temperature annealing of silver only sample. • Iodine was retained in iodine only sample after high temperature annealing. • Iodine was found to play a role in the retention of Ag in the co-implanted samples.

  13. Pulmonary heart valve replacement using stabilized acellular xenogeneic scaffolds; effects of seeding with autologous stem cells

    Directory of Open Access Journals (Sweden)

    Harpa Marius Mihai

    2015-12-01

    Full Text Available Background: We hypothesized that an ideal heart valve replacement would be acellular valve root scaffolds seeded with autologous stem cells. To test this hypothesis, we prepared porcine acellular pulmonary valves, seeded them with autologous adipose derived stem cells (ADSCs and implanted them in sheep and compared them to acellular valves.

  14. Surface modifications of dental implants.

    Science.gov (United States)

    Stanford, C M

    2008-06-01

    Dental implant surface technologies have been evolving rapidly to enhance a more rapid bone formation on their surface and hold a potential to increase the predictability of expedited implant therapy. While implant outcomes have become highly predictable, there are sites and conditions that result in elevated implant loss. This paper reviews the impact of macro-retentive features which includes approaches to surface oxide modification, thread design, press-fit and sintered-bead technologies to increase predictability of outcomes. Implant designs that lead to controlled lateral compression of the bone can improve primary stability as long as the stress does not exceed the localized yield strength of the cortical bone. Some implant designs have reduced crestal bone loss by use of multiple cutting threads that are closely spaced, smoothed on the tip but designed to create a hoop-stress stability of the implant as it is completely seated in the osteotomy. Following the placement of the implant, there is a predictable sequence of bone turnover and replacement at the interface that allows the newly formed bone to adapt to microscopic roughness on the implant surface, and on some surfaces, a nanotopography (<10(-9) m scale) that has been shown to preferably influence the formation of bone. Newly emerging studies show that bone cells are exquisitely sensitive to these topographical features and will upregulate the expression of bone related genes for new bone formation when grown on these surfaces. We live in an exciting time of rapid changes in the modalities we can offer patients for tooth replacement therapy. Given this, it is our responsibility to be critical when claims are made, incorporate into our practice what is proven and worthwhile, and to continue to support and provide the best patient care possible.

  15. Bilateral implant-retained auricular prosthesis for a patient with congenitally missing ears. A clinical report.

    Science.gov (United States)

    Kumar, Preeti Satheesh; Satheesh Kumar, K S; Savadi, Ravindra C

    2012-06-01

    Microtia is a major congenital anomaly of the external ear. It includes a spectrum of deformities from a grossly normal but small ear to the absence of the entire external ear. These deformities account for three in every 10,000 births, with bilaterally missing ears seen in fewer than 10% of all cases. Congenital abnormalities of the ear are unlikely to result in the complete absence of the ears, but the patient presented in this article had bilateral congenitally missing ears. There was loss of anatomic landmarks and alteration of normal bony architecture. Minimal tissue was available for retention; therefore, conventional techniques could not be used for achieving retention. A two-implant-supported auricular prosthesis was planned, but the patient was found to have deficient bone in the implant site. Hence the implants were placed posterior to these sites, and the superstructure was modified to accommodate for this change in position of the implant to ensure the esthetic positioning of the prosthesis. © 2012 by the American College of Prosthodontists.

  16. Lupin seed meal (Lupinus albus cv. Buttercup) as a source of ...

    African Journals Online (AJOL)

    (teen 'n 8%-insluitingspell) as gedeeltelike vervanger vir volvetsojabone, te evalueer. Die ... lupins, digestibility, N retention, growth, alkaloids, pigs. Introduction. Lupin-seed has been used extensively in pig diets ... meal, but at higher levels both growth rate and feed conversion efficiency were significantly depressed. Feed.

  17. Methodology of quality control for brachytherapy {sup 125}I seeds

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Eduardo S.; Zeituni, Carlos A.; Manzoli, Jose E.; Rostelato, Maria Elisa C.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: esmoura@ipen.br

    2007-07-01

    This paper presents the methodology of quality control of {sup 125}I seeds used for brachytherapy. The {sup 125}I seeds are millimeter titanium capsules widely used in permanent implants of prostate cancer, allowing a high dose within the tumour and a low dose on the surrounding tissues, with very low harm to the other tissues. Besides, with this procedure, the patients have a low impotence rate and a small incidence of urinary incontinence. To meet the medical standards, an efficient quality control is necessary, showing values with the minimum uncertainness possible, concerning the seeds dimensions and their respective activities. The medical needles are used to insert the seeds inside the prostate. The needles used in brachytherapy have an internal diameter of 1.0 mm, so it is necessary {sup 125}I seeds with an external maximum diameter of 0.85 mm. For the seeds and the spacer positioning on the planning sheet, the seeds must have a length between 4.5 and 5.0 mm. The activities must not vary more than 5% in each batch of {sup 125}I seeds. For this methodology, we used two ionization chamber detectors and one caliper. In this paper, the methodology using one control batch with 75 seeds manufactured by GE Health care Ltd is presented. (author)

  18. Extremely long-distance seed dispersal by an overfished Amazonian frugivore.

    Science.gov (United States)

    Anderson, Jill T; Nuttle, Tim; Saldaña Rojas, Joe S; Pendergast, Thomas H; Flecker, Alexander S

    2011-11-22

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337-552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700-2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.

  19. Telescopic crowns as attachments for implant supported restorations: a case series.

    Science.gov (United States)

    Hoffmann, Oliver; Beaumont, Christian; Tatakis, Dimitris N; Zafiropoulos, Gregory-George

    2006-01-01

    The use of dental implants to support mandibular or maxillary overdentures is a widely used treatment modality. Advantages are an increase in retention, an increase in chewing ability, and easy access for oral hygiene procedures. While telescopic and conical crowns have been used for decades to connect natural teeth to overdentures, not many cases have been reported in the literature of telescopic crowns placed on implants to support overdentures. This article describes 7 patients with overdentures supported by telescopic crowns who received 65 implants (ITI Straumann). The cases presented in this report have been in function for up to 4.5 years. During that time no adverse events were reported. The use of telescopic crowns as attachments for implant-supported overdentures may be a viable treatment option.

  20. Biomechanical implant treatment complications: a systematic review of clinical studies of implants with at least 1 year of functional loading.

    Science.gov (United States)

    Hsu, Yung-Ting; Fu, Jia-Hui; Al-Hezaimi, Khalid; Wang, Hom-Lay

    2012-01-01

    The aim of this article is to discuss the current literature available on the etiology and management of biomechanical complications of dental implant treatment. An electronic search of the PubMed database for English-language articles published before May 31, 2011, was performed based on a focus question: "How can biomechanical implant treatment complications be managed and identified?" The key words used were "dental implant," "etiology," "management," "excessive occlusal forces," "occlusal forces," "occlusion," "parafunctional habits," "biomechanical failure," "biomechanical complications," and "occlusal overloading." Clinical trials with a minimum of 10 implants followed for at least 1 year after functional loading were included. The initial electronic search identified 2,087 publications, most of which were eliminated, as they were animal studies, finite element analyses, bench-top studies, case reports, and literature reviews. After the titles, abstracts, and full text of 39 potentially eligible publications were reviewed, 15 studies were found to fulfill the inclusion criteria. Occlusal overloading was thought to be the primary etiologic factor in biomechanical implant treatment complications, which commonly included marginal bone loss, fracture of resin/ceramic veneers and porcelain, retention device or denture base fracture of implant-supported overdentures, loosening or fracture of abutment screws, and even implant failure. Occlusal overloading was positively associated with parafunctional habits such as bruxism. An appreciation of the intricacy of implant occlusion would allow clinicians to take a more preventive approach when performing implant treatment planning, as avoidance of implant overloading helps to ensure the long-term stability of implant-supported prostheses.

  1. Interaction of implanted deuterium and helium with beryllium: radiation enhanced oxidation

    International Nuclear Information System (INIS)

    Langley, R.A.

    1979-01-01

    The interaction of implanted deuterium and helium with beryllium is of significant interest in the application of first wall coatings and other components of fusion reactors. Electropolished polycrystalline beryllium was first implanted with an Xe backscatter marker at 1.98 MeV followed by either implantation with 5 keV diatomic deuterium or helium. A 2.0 MeV He beam was used to analyze for impurity buildup; namely oxygen. The oxide layer thickness was found to increase linearly with increasing implant fluence. A 2.5 MeV H + beam was used to depth profile the D and He by ion backscattering. In addition the retention of the implant was measured as a function of the implant fluence. The mean depth of the implant was found to agree with theoretical range calculations. Scanning electron microscopy was used to observe blister formation. No blisters were observed for implanted D but for implanted He blisters occurred at approx. 1.75 x 10 17 He cm -2 . The blister diameter increased with increasing implant fluence from about 0.8 μm at 10 18 He cm -2 to 5.5 μm at 3 x 10 18 He cm -2

  2. Factors influencing success of cement versus screw-retained implant restorations: a clinical review

    Directory of Open Access Journals (Sweden)

    Ahmad Manawar

    2012-10-01

    Full Text Available Aim: As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw retained prosthesis to be the best choice. Discussion: In screw-retained restorations, the fastening screw provides a solid joint between the restoration and the implant abutment, while in cement-retained prostheses the restorative screw is eliminated to enhance esthetics, occlusal stability, and passive fit of the restorations. The factors that influence the type of fixation of the prostheses to the implants like passivity of the framework, ease of fabrication, occlusion, esthetics, accessibility, retention and retrievability are discussed in this article with scientific studies demonstrating superior outcomes of one technique over another. Screwretained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained subgingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminate unesthetic screw access holes, have passive fit of castings, reduced complexity of clinical and lab procedures, enhanced esthetics, reduced cost factors and non disrupted morphology of the occlusal table. Conclusion: This article compares the advantages, potential disadvantages and limitations of screw and cement retained restorations and their specific implications in the most common clinical situation.

  3. 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.)

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

    Science.gov (United States)

    Pokhrel, Damodar; Murphy, Martin J; Todor, Dorin A; Weiss, Elisabeth; Williamson, Jeffrey F

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-15

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

  6. A Qualitative Study on Patients' Perceptions of Two Types of Attachments for Implant Overdentures.

    Science.gov (United States)

    Pisani, Marina; Bedos, Christophe; da Silva, Cláudia Helena Lovato; Fromentin, Olivier; de Albuquerque, Rubens F

    2017-12-01

    The aim of this qualitative study was to gain a deeper understanding of patient perceptions of wearing implant-retained overdentures with ball-shaped or cylindrical attachment systems. Twenty-two wearers of implant-supported overdentures participated in this qualitative study based on a randomized crossover clinical trial that aimed to compare a cylindrical attachment and a ball attachment. In phase I of the study, group A experienced ball attachments (n = 11) and group B Locator attachments (n = 11) for 1 year. Afterward, in phase II, the attachments were changed; group A received Locator attachments and group B received ball attachments. One week after the attachment's replacement, semistructured individual interviews were conducted. All interviews were audiotaped and transcribed. The analysis was guided by thematic content analysis. Most of the patients from both groups preferred the attachment they received in phase II, regardless the type. A major theme raised by the participants to justify their preference between the attachment types was prosthesis retention/stability, sometimes considered as a positive and other times as a negative factor. Other themes were also explored: oral function, pain, hygiene, previous experiences, confidence on the dentist's work, and esthetic. Aspects related to the retention/stability of the overdentures are the main concerns associated with the perceptions of most patients treated with implant overdentures regardless of the type of attachment. Adequate retention level should be identified and adjusted on an individual basis and maintained overtime as possible. Therefore, follow-up appointments should be planned for readjustment of the attachment's retention. Overretention should be avoided.

  7. Prostate implant reconstruction from C-arm images with motion-compensated tomosynthesis

    International Nuclear Information System (INIS)

    Dehghan, Ehsan; Moradi, Mehdi; Wen, Xu; French, Danny; Lobo, Julio; Morris, W. James; Salcudean, Septimiu E.; Fichtinger, Gabor

    2011-01-01

    Purpose: Accurate localization of prostate implants from several C-arm images is necessary for ultrasound-fluoroscopy fusion and intraoperative dosimetry. The authors propose a computational motion compensation method for tomosynthesis-based reconstruction that enables 3D localization of prostate implants from C-arm images despite C-arm oscillation and sagging. Methods: Five C-arm images are captured by rotating the C-arm around its primary axis, while measuring its rotation angle using a protractor or the C-arm joint encoder. The C-arm images are processed to obtain binary seed-only images from which a volume of interest is reconstructed. The motion compensation algorithm, iteratively, compensates for 2D translational motion of the C-arm by maximizing the number of voxels that project on a seed projection in all of the images. This obviates the need for C-arm full pose tracking traditionally implemented using radio-opaque fiducials or external trackers. The proposed reconstruction method is tested in simulations, in a phantom study and on ten patient data sets. Results: In a phantom implanted with 136 dummy seeds, the seed detection rate was 100% with a localization error of 0.86 ± 0.44 mm (Mean ± STD) compared to CT. For patient data sets, a detection rate of 99.5% was achieved in approximately 1 min per patient. The reconstruction results for patient data sets were compared against an available matching-based reconstruction method and showed relative localization difference of 0.5 ± 0.4 mm. Conclusions: The motion compensation method can successfully compensate for large C-arm motion without using radio-opaque fiducial or external trackers. Considering the efficacy of the algorithm, its successful reconstruction rate and low computational burden, the algorithm is feasible for clinical use.

  8. Prostate implant reconstruction from C-arm images with motion-compensated tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Dehghan, Ehsan; Moradi, Mehdi; Wen, Xu; French, Danny; Lobo, Julio; Morris, W. James; Salcudean, Septimiu E.; Fichtinger, Gabor [School of Computing, Queen' s University, Kingston, Ontario K7L-3N6 (Canada); Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T-1Z4 (Canada); Vancouver Cancer Centre, Vancouver, British Columbia V5Z-1E6 (Canada); Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T-1Z4 (Canada); School of Computing, Queen' s University, Kingston, Ontario K7L-3N6 (Canada)

    2011-10-15

    Purpose: Accurate localization of prostate implants from several C-arm images is necessary for ultrasound-fluoroscopy fusion and intraoperative dosimetry. The authors propose a computational motion compensation method for tomosynthesis-based reconstruction that enables 3D localization of prostate implants from C-arm images despite C-arm oscillation and sagging. Methods: Five C-arm images are captured by rotating the C-arm around its primary axis, while measuring its rotation angle using a protractor or the C-arm joint encoder. The C-arm images are processed to obtain binary seed-only images from which a volume of interest is reconstructed. The motion compensation algorithm, iteratively, compensates for 2D translational motion of the C-arm by maximizing the number of voxels that project on a seed projection in all of the images. This obviates the need for C-arm full pose tracking traditionally implemented using radio-opaque fiducials or external trackers. The proposed reconstruction method is tested in simulations, in a phantom study and on ten patient data sets. Results: In a phantom implanted with 136 dummy seeds, the seed detection rate was 100% with a localization error of 0.86 {+-} 0.44 mm (Mean {+-} STD) compared to CT. For patient data sets, a detection rate of 99.5% was achieved in approximately 1 min per patient. The reconstruction results for patient data sets were compared against an available matching-based reconstruction method and showed relative localization difference of 0.5 {+-} 0.4 mm. Conclusions: The motion compensation method can successfully compensate for large C-arm motion without using radio-opaque fiducial or external trackers. Considering the efficacy of the algorithm, its successful reconstruction rate and low computational burden, the algorithm is feasible for clinical use.

  9. Covering the screw-access holes of implant restorations in the esthetic zone: a clinical report.

    Directory of Open Access Journals (Sweden)

    Abolfazl Saboury

    2014-12-01

    Full Text Available Screw-retained implant restorations have an advantage of predictable retention as well as retrievability, and obviate the risk of excessive sub-gingival cement commonly associated with cement retained implant restorations. Screw-retained restorations generally have screw access holes, which can compromise esthetics and weaken the porcelain around the holes. The purpose of this study is to describe the use of a separate overcasting crown design to cover the screw access hole of implant screw-retained prosthesis for improved esthetics.

  10. Comparison of cotton square and boll damage and resulting lint and seed loss caused by verde plant bug, Creontiades signatus

    Science.gov (United States)

    Retention of bolls and squares (referred to as fruit retention), boll damage, and resulting cotton lint and seed weight loss were assessed when two (2010) and three (2011) age classes of sympodial fruiting branches with different ages of squares and bolls where exposed to verde plant bug, Creontiade...

  11. BrachyView: Combining LDR seed positions with transrectal ultrasound imaging in a prostate gel phantom.

    Science.gov (United States)

    Alnaghy, S; Cutajar, D L; Bucci, J A; Enari, K; Safavi-Naeini, M; Favoino, M; Tartaglia, M; Carriero, F; Jakubek, J; Pospisil, S; Lerch, M; Rosenfeld, A B; Petasecca, M

    2017-02-01

    BrachyView is a novel in-body imaging system which aims to provide LDR brachytherapy seeds position reconstruction within the prostate in real-time. The first prototype is presented in this study: the probe consists of a gamma camera featuring three single cone pinhole collimators embedded in a tungsten tube, above three, high resolution pixelated detectors (Timepix). The prostate was imaged with a TRUS system using a sagittal crystal with a 2.5mm slice thickness. Eleven needles containing a total of thirty 0.508U 125 I seeds were implanted under ultrasound guidance. A CT scan was used to localise the seed positions, as well as provide a reference when performing the image co-registration between the BrachyView coordinate system and the TRUS coordinate system. An in-house visualisation software interface was developed to provide a quantitative 3D reconstructed prostate based on the TRUS images and co-registered with the LDR seeds in situ. A rigid body image registration was performed between the BrachyView and TRUS systems, with the BrachyView and CT-derived source locations compared. The reconstructed seed positions determined by the BrachyView probe showed a maximum discrepancy of 1.78mm, with 75% of the seeds reconstructed within 1mm of their nominal location. An accurate co-registration between the BrachyView and TRUS coordinate system was established. The BrachyView system has shown its ability to reconstruct all implanted LDR seeds within a tissue equivalent prostate gel phantom, providing both anatomical and seed position information in a single interface. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Use of an Implant O-Ring Attachment for the Tooth Supported Mandibular Overdenture: A Clinical Report

    OpenAIRE

    Guttal, Satyabodh S.; Tavargeri, Anand K.; Nadiger, Ramesh K.; Thakur, Srinath L.

    2011-01-01

    Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. The same design principles holds true for both implant-retained and tooth-retained methods of anchoring the bar and stud attachment. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. When few firm teeth still remain in a compromised dentition, pres...

  13. Influence of implantoplasty on stress distribution of exposed implants at different bone insertion levels

    Directory of Open Access Journals (Sweden)

    João Paulo Mendes TRIBST

    2017-12-01

    Full Text Available Abstract This study evaluated the effect of implantoplasty on different bone insertion levels of exposed implants. A model of the Bone Level Tapered implant (Straumann Institute, Waldenburg, Switzerland was created through the Rhinoceros software (version 5.0 SR8, McNeel North America, Seattle, WA, USA. The abutment was fixed to the implant through a retention screw and a monolithic crown was modeled over a cementation line. Six models were created with increasing portions of the implant threads exposed: C1 (1 mm, C2 (2 mm, C3 (3 mm, C4 (4 mm, C5 (5 mm and C6 (6 mm. The models were made in duplicates and one of each pair was used to simulate implantoplasty, by removing the threads (I1, I2, I3, I4, I5 and I6. The final geometry was exported in STEP format to ANSYS (ANSYS 15.0, ANSYS Inc., Houston, USA and all materials were considered homogeneous, isotropic and linearly elastic. To assess distribution of stress forces, an axial load (300 N was applied on the cusp. For the periodontal insert, the strains increased in the peri-implant region according to the size of the exposed portion and independent of the threads’ presence. The difference between groups with and without implantoplasty was less than 10%. Critical values were found when the inserted portion was smaller than the exposed portion. In the exposed implants, the stress generated on the implant and retention screw was higher in the models that received implantoplasty. For the bone tissue, exposure of the implant’s thread was a damaging factor, independent of implantoplasty. Implantoplasty treatment can be safely used to control peri-implantitis if at least half of the implant is still inserted in bone.

  14. The medically compromised patient: Are dental implants a feasible option?

    Science.gov (United States)

    Vissink, A; Spijkervet, Fkl; Raghoebar, G M

    2018-03-01

    In healthy subjects, dental implants have evolved to be a common therapy to solve problems related to stability and retention of dentures as well as to replace failing teeth. Although dental implants are applied in medically compromised patients, it is often not well known whether this therapy is also feasible in these patients, whether the risk of implant failure and developing peri-implantitis is increased, and what specific preventive measures, if any, have to be taken when applying dental implants in these patients. Generally speaking, as was the conclusion by the leading review of Diz, Scully, and Sanz on placement of dental implants in medically compromised patients (J Dent, 41, 2013, 195), in a few disorders implant survival may be lower, and the risk of a compromised peri-implant health and its related complications be greater, but the degree of systemic disease control outweighs the nature of the disorder rather than the risk accompanying dental implant treatment. So, as dental implant treatment is accompanied by significant functional benefits and improved oral health-related quality of life, dental implant therapy is a feasible treatment in almost any medically compromised patient when the required preventive measures are taken and follow-up care is at a high level. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.

  15. Ammonia production in nitrogen seeded plasma discharges in ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, V., E-mail: Volker.Rohde@ipp.mpg.de; Oberkofler, M.

    2015-08-15

    In present tokamaks nitrogen seeding is used to reduce the power load onto the divertor tiles. Some fraction of the seeded nitrogen reacts with hydrogen to form ammonia. The behaviour of ammonia in ASDEX Upgrade is studied by mass spectrometry. Injection without plasma shows strong absorption at the inner walls of the vessel and isotope exchange reactions. During nitrogen seeding in H-mode discharges the onset of a saturation of the nitrogen retention is observed. The residual gas consists of strongly deuterated methane and ammonia with almost equal amounts of deuterium and protium. This confirms the role of surface reactions in the ammonia formation. The results are consistent with findings in previous investigations. A numerical decomposition of mass spectra is under development and will be needed for quantitative evaluation of the results obtained.

  16. In Vitro and In Vivo Osteogenic Activity of Titanium Implants Coated by Pulsed Laser Deposition with a Thin Film of Fluoridated Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Luyuan Chen

    2018-04-01

    Full Text Available To enhance biocompatibility, osteogenesis, and osseointegration, we coated titanium implants, by krypton fluoride (KrF pulsed laser deposition, with a thin film of fluoridated hydroxyapatite (FHA. Coating was confirmed by scanning electron microscopy (SEM and scanning probe microscopy (SPM, while physicochemical properties were evaluated by attenuated reflectance Fourier transform infrared spectroscopy (ATR-FTIR. Calcium deposition, osteocalcin production, and expression of osteoblast genes were significantly higher in rat bone marrow mesenchymal stem cells seeded on FHA-coated titanium than in cells seeded on uncoated titanium. Implantation into rat femurs also showed that the FHA-coated material had superior osteoinductive and osseointegration activity in comparison with that of traditional implants, as assessed by microcomputed tomography and histology. Thus, titanium coated with FHA holds promise as a dental implant material.

  17. Collagen-coated polylactic-glycolic acid (PLGA) seeded with neural-differentiated human mesenchymal stem cells as a potential nerve conduit.

    Science.gov (United States)

    Sulong, Ahmad Fadzli; Hassan, Nur Hidayah; Hwei, Ng Min; Lokanathan, Yogeswaran; Naicker, Amaramalar Selvi; Abdullah, Shalimar; Yusof, Mohd Reusmaazran; Htwe, Ohnmar; Idrus, Ruszymah Bt Hj; Haflah, Nor Hazla Mohamed

    2014-01-01

    Autologous nerve grafts to bridge nerve gaps pose various drawbacks. Nerve tissue engineering to promote nerve regeneration using artificial neural conduits has emerged as a promising alternative. To develop an artificial nerve conduit using collagen-coated polylactic-glycolic acid (PLGA) and to analyse the survivability and propagating ability of the neuro-differentiated human mesenchymal stem cells in this conduit. The PLGA conduit was constructed by dip-molding method and coated with collagen by immersing the conduit in collagen bath. The ultra structure of the conduits were examined before they were seeded with neural-differentiated human mesenchymal stem cells (nMSC) and implanted sub-muscularly on nude mice thighs. The non-collagen-coated PLGA conduit seeded with nMSC and non-seeded non-collagen-coated PLGA conduit were also implanted for comparison purposes. The survivability and propagation ability of nMSC was studied by histological and immunohistochemical analysis. The collagen-coated conduits had a smooth inner wall and a highly porous outer wall. Conduits coated with collagen and seeded with nMSCs produced the most number of cells after 3 weeks. The best conduit based on the number of cells contained within it after 3 weeks was the collagen-coated PLGA conduit seeded with neuro-transdifferentiated cells. The collagen-coated PLGA conduit found to be suitable for attachment, survival and proliferation of the nMSC. Minimal cell infiltration was found in the implanted conduits where nearly all of the cells found in the cell seeded conduits are non-mouse origin and have neural cell markers, which exhibit the biocompatibility of the conduits. The collagen-coated PLGA conduit is biocompatible, non-cytotoxic and suitable for use as artificial nerve conduits.

  18. The role of endorectal coil MRI in patient selection and treatment planning for prostate seed implants

    International Nuclear Information System (INIS)

    Clarke, Daniel H.; Banks, Stephen J.; Wiederhorn, A. Roger; Klousia, John W.; Lissy, Jeanne M.; Miller, Michelle; Able, Arnold M.; Artiles, Carlos; Hindle, William V.; Blair, Deborah N.; Houk, Russell R.; Sheridan, Michael J.

    2002-01-01

    Purpose: To assess the role of endorectal coil magnetic resonance imaging (MRI) staging for patients undergoing seed implantation (SI) with or without external beam radiotherapy (EBRT). Methods and Materials: Between October 1994 and December 1998, 390 patients underwent prostate SI (98% Pd-103, 2% I-125). Seventy-six percent of patients had a prostate serum antigen (PSA) 20. Ten percent of patients had a Gleason score (GS) of 4-5, 54% had GS 6, 29% had GS 7, and 7% had GS ≥ 8. Monotherapy was employed in 46% of patients, and the remaining 54% received combined EBRT and SI. Three hundred twenty-seven were staged by high-resolution phased array pelvic coil, or in most cases, an endorectal coil MRI. The MRI findings were used to guide stage-appropriate treatment recommendations, and to assist in the preplanning and optimization of seed distributions. The criteria utilized to determine MRI-based stage were founded on the reported literature from the University of Pennsylvania. All MRI studies were reviewed by C.A., D.B., or W.H., who were unaware of clinical stage at the time of their review. The biopsy report was available to them as the only clinical correlate. Results: Of the 327 patients staged by MRI, 70% were upstaged from the digital rectal examination-based clinical stage; 26% of T 1 , T 2 patients were upstaged to T 3 . Perineural invasion and the percentage of positive cores predicted for T 3 MRI stage (p 3 intermediate-risk group patients treated by combined therapy with a previous study of T 3 intermediate-risk group treated by radical prostatectomy (RP) at the University of Pennsylvania. Our 36-month PSA FFP was 94% compared with 21% for the previous study's RP patients. Conclusion: MRI is a valuable staging procedure for prostate cancer patients treated by SI. PSA FFP results appear to be improved by MRI staging. MRI T 3 disease can be treated more effectively by SI + EBRT than by RP

  19. Preparation of Bioactive Titanium Surfaces via Fluoride and Fibronectin Retention

    Directory of Open Access Journals (Sweden)

    Carlos Nelson Elias

    2012-01-01

    Full Text Available Statement of Problem. The chemical or topographic modification of the dental implant surface can affect bone healing, promote accelerated osteogenesis, and increase bone-implant contact and bonding strength. Objective. In this work, the effects of dental implant surface treatment and fibronectin adsorption on the adhesion of osteoblasts were analyzed. Materials and Methods. Two titanium dental implants (Porous-acid etching and PorousNano-acid etching followed by fluoride ion modification were characterized by high-resolution scanning electron microscopy, atomic force microscopy, and X-ray diffraction before and after the incorporation of human plasma fibronectin (FN. The objective was to investigate the biofunctionalization of these surfaces and examine their effects on the interaction with osteoblastic cells. Results. The evaluation techniques used showed that the Porous and PorousNano implants have similar microstructural characteristics. Spectrophotometry demonstrated similar levels of fibronectin adsorption on both surfaces (80%. The association indexes of osteoblastic cells in FN-treated samples were significantly higher than those in samples without FN. The radioactivity values associated with the same samples, expressed as counts per minute (cpm, suggested that FN incorporation is an important determinant of the in vitro cytocompatibility of the surfaces. Conclusion. The preparation of bioactive titanium surfaces via fluoride and FN retention proved to be a useful treatment to optimize and to accelerate the osseointegration process for dental implants.

  20. A technique for accurate planning of stereotactic brain implants prior to head ring fixation

    International Nuclear Information System (INIS)

    Ulin, Kenneth; Bornstein, Linda E.; Ling, Marilyn N.; Saris, Stephen; Wu, Julian K.; Curran, Bruce H.; Wazer, David E.

    1997-01-01

    Purpose: A two-step procedure is described for accurate planning of stereotactic brain implants prior to head-ring fixation. Methods and Materials: Approximately 2 weeks prior to implant a CT scan without the head ring is performed for treatment-planning purposes. An entry point and a reference point, both marked with barium and later tattooed, facilitate planning and permit correlation of the images with a later CT scan. A plan is generated using a conventional treatment-planning system to determine the number and activity of I-125 seeds required and the position of each catheter. I-125 seed anisotropy is taken into account by means of a modification to the treatment planning program. On the day of the implant a second CT scan is performed with the head ring affixed to the skull and with the same points marked as in the previous scan. The planned catheter coordinates are then mapped into the coordinate system of the second CT scan by means of a manual translational correction and a computer-calculated rotational correction derived from the reference point coordinates in the two scans. Results: The rotational correction algorithm was verified experimentally in a Rando phantom before it was used clinically. For analysis of the results with individual patients a third CT scan is performed 1 day following the implant and is used for calculating the final dosimetry. Conclusion: The technique that is described has two important advantages: 1) the number and activity of seeds required can be accurately determined in advance; and 2) sufficient time is allowed to derive the best possible plan

  1. Long-term survival rate of implant-supported overdentures with various attachment systems: A 20-year retrospective study

    Directory of Open Access Journals (Sweden)

    Hao-Sheng Chang

    2015-03-01

    Conclusion: The overall survival rate of dental implants with overdenture rehabilitation was 95.3% (91.3% in maxillae vs. 96.4% in mandibles within the past 20 years. With careful treatment planning, implant-supported overdenture is an interesting treatment alternative with better esthetic, retention, stability, and good hygienic maintenance for patients with severe ridge resorption.

  2. Impurity effects of hydrogen isotope retention on boronized wall in LHD

    International Nuclear Information System (INIS)

    Oya, Yasuhisa; Okuno, Kenji; Ashikawa, Naoko; Nishimura, Kiyohiko; Sagara, Akio

    2010-11-01

    The impurity effect on hydrogen isotopes retention in the boron film deposited in LHD was evaluated by means of XPS and TDS. It was found that the impurity concentrations in boron film were increased after H-H main plasma exposure in LHD. The ratio of hydrogen retention trapped by impurity to total hydrogen retention during H-H main plasma exposure was reached to 70%, although that of deuterium retention by impurity in D 2 + implanted LHD-boron film was about 35%. In addition, the dynamic chemical sputtering of hydrogen isotopes with impurity as the form of water and / or hydrocarbons was occurred by energetic hydrogen isotopes irradiation. It was expected that the enhancement of impurity concentration during plasma exposure in LHD would induce the dynamic formation of volatile molecules and their re-emission to plasma. These facts would prevent stable plasma operation in LHD, concluding that the dynamic impurity behavior in boron film during plasma exposure is one of key issues for the steady-state plasma operation in LHD. (author)

  3. 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.

  4. Erosion behaviour of ultrathin carbon layers and hydrogen retention in beryllium

    International Nuclear Information System (INIS)

    Reinelt, Matthias

    2008-01-01

    Plasma-wall-interaction plays an important role on the way to technical feasibility of thermonuclear fusion. In this context, the erosion behavior of few nanometer thin amorphous carbon layers on different metallic substrates by energetic deuterium and helium ions is investigated. Several aspects of the interaction are distinguishable by XPS. Ion induced carbide formation is governed by kinematic intermixing of carbon and metal substrate. Several methods of quantification of XPS measurements are developed and discussed. Comparison of results from these methods with NRA measurements show that surface roughness and implantation of particles into the carbon layer and intermixing zone influence the XPS measurements, which are sensitive to parameters such as material density. The retention of 1 keV deuterium ions implanted into single crystalline and cleaned beryllium at room temperature is investigated by temperature programmed desorption (TPD). The residual BeO coverage was 0.2 ML. The retention is 78% at low fluences and saturates above a bombardment with a fluence of 2.10 17 cm -2 . The retained maximum areal density is 2.10 17 cm -2 . Above 900 K, no deuterium is retained in the sample. An onset of self diffusion is observed at this temperature and metallic beryllium from the bulk segregates though thin BeO layers on the surface. From deuterium desorption traces, retention mechanisms are obtained. The measured TPDspectra are modeled by TMAP7 and rate equations to obtain activation energies for the release processes. From these, binding energies for the system Be-D are derived. Up to a implantation fluence of 1.10 17 cm -2 , deuterium is trapped in ion induced defects in the beryllium lattice with binding energies of 1.69 eV and 1.86 eV and release temperatures of 770 K and 840 K, respectively. The occupation of these states shows a different isotope behavior for 1 H and 2 H. The states are filled by diffusion of deuterium at the end of its implantation trajectory

  5. Indirect Effects of Field Management on Pollination Service and Seed Set in Hybrid Onion Seed Production.

    Science.gov (United States)

    Gillespie, Sandra; Long, Rachael; Williams, Neal

    2015-12-01

    Pollination in crops, as in native ecosystems, is a stepwise process that can be disrupted at any stage. Healthy pollinator populations are critical for adequate visitation, but pollination still might fail if crop management interferes with the attraction and retention of pollinators. Farmers must balance the direct benefits of applying insecticide and managing irrigation rates against their potential to indirectly interfere with the pollination process. We investigated these issues in hybrid onion seed production, where previous research has shown that high insecticide use reduces pollinator attraction. We conducted field surveys of soil moisture, nectar production, pollinator visitation, pollen-stigma interactions, and seed set at multiple commercial fields across 2 yr. We then examined how management actions, such as irrigation rate (approximated by soil moisture), or insecticide use could affect the pollination process. Onions produced maximum nectar at intermediate soil moisture, and high nectar production attracted more pollinators. Insecticide use weakly affected pollinator visitation, but when applied close to bloom reduced pollen germination and pollen tube growth. Ultimately, neither soil moisture nor insecticide use directly affected seed set, but the high correlation between pollinator visitation and seed set suggests that crop management will ultimately affect yields via indirect effects on the pollination process. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Sunflower seed allergy

    Science.gov (United States)

    Ukleja-Sokołowska, Natalia; Gawrońska-Ukleja, Ewa; Żbikowska-Gotz, Magdalena; Bartuzi, Zbigniew; Sokołowski, Łukasz

    2016-01-01

    Sunflower seeds are a rare source of allergy, but several cases of occupational allergies to sunflowers have been described. Sunflower allergens on the whole, however, still await precise and systematic description. We present an interesting case of a 40-year-old male patient, admitted to hospital due to shortness of breath and urticaria, both of which appeared shortly after the patient ingested sunflower seeds. Our laryngological examination revealed swelling of the pharynx with retention of saliva and swelling of the mouth and tongue. During diagnostics, 2 months later, we found that skin prick tests were positive to mugwort pollen (12/9 mm), oranges (6/6 mm), egg protein (3/3 mm), and hazelnuts (3/3 mm). A native prick by prick test with sunflower seeds was strongly positive (8/5 mm). Elevated concentrations of specific IgE against weed mix (inc. lenscale, mugwort, ragweed) allergens (1.04 IU/mL), Artemisia vulgaris (1.36 IU/mL), and Artemisia absinthium (0.49 IU/mL) were found. An ImmunoCap ISAC test found an average level of specific IgE against mugwort pollen allergen component Art v 1 - 5,7 ISU-E, indicating an allergy to mugwort pollen and low to medium levels of specific IgE against lipid transfer proteins (LTP) found in walnuts, peanuts, mugwort pollen, and hazelnuts. Through the ISAC inhibition test we proved that sunflower seed allergen extracts contain proteins cross-reactive with patients’ IgE specific to Art v 1, Art v 3, and Jug r 3. Based on our results and the clinical pattern of the disease we confirmed that the patient is allergic to mugwort pollen and that he had an anaphylactic reaction as a result of ingesting sunflower seeds. We suspected that hypersensitivity to sunflower LTP and defensin-like proteins, both cross-reactive with mugwort pollen allergens, were the main cause of the patient’s anaphylactic reaction. PMID:27222528

  7. Interaction of implanted deuterium and helium with beryllium: radiation enhanced oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Langley, R.A.

    1979-01-01

    The interaction of implanted deuterium and helium with beryllium is of significant interest in the application of first wall coatings and other components of fusion reactors. Electropolished polycrystalline beryllium was first implanted with an Xe backscatter marker at 1.98 MeV followed by either implantation with 5 keV diatomic deuterium or helium. A 2.0 MeV He beam was used to analyze for impurity buildup; namely oxygen. The oxide layer thickness was found to increase linearly with increasing implant fluence. A 2.5 MeV H/sup +/ beam was used to depth profile the D and He by ion backscattering. In addition the retention of the implant was measured as a function of the implant fluence. The mean depth of the implant was found to agree with theoretical range calculations. Scanning electron microscopy was used to observe blister formation. No blisters were observed for implanted D but for implanted He blisters occurred at approx. 1.75 x 10/sup 17/ He cm/sup -2/. The blister diameter increased with increasing implant fluence from about 0.8 ..mu..m at 10/sup 18/ He cm/sup -2/ to 5.5 ..mu..m at 3 x 10/sup 18/ He cm/sup -2/.

  8. Mini dental implants retaining mandibular overdentures: A dental practice-based retrospective analysis.

    Science.gov (United States)

    Schwindling, Franz Sebastian; Schwindling, Franz-Peter

    2016-07-01

    The purpose of this study was to assess the survival of mini dental implants (MDI) and to measure prosthetic maintenance needs in a dental practice-based setting. Patients with mandibular removable dentures were provided with MDI to improve denture retention. Complications and maintenance were analyzed by use of patient records and evaluated with Kaplan-Meier curves and the log rank test at a significance level of 0.05. Ninety-nine MDI were placed in 25 patients (mean age: 72 years). Two MDI fractured during placement and eight implants failed during the first weeks. No more implants were lost for up to seven years, resulting in 92% survival. Implant survival differed significantly depending on whether the maxilla was provided with complete dentures (94.9%) or with partial dentures (81%). All prostheses were in use at the time of data extraction. Denture base fractures were observed in six cases, an incidence of fractures of 24%. Some minor intervention was necessary: one resin tooth fractured, retention rings were changed in five cases, and repeated relining was required for 16% of the dentures. After mid-term observation, survival of MDI was good. However, the incidence of denture base fractures and of minor prosthetic complications should not be under-estimated. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. The healing of bony defects by cell-free collagen-based scaffolds compared to stem cell-seeded tissue engineered constructs.

    LENUS (Irish Health Repository)

    Lyons, Frank G

    2010-12-01

    One of the key challenges in tissue engineering is to understand the host response to scaffolds and engineered constructs. We present a study in which two collagen-based scaffolds developed for bone repair: a collagen-glycosaminoglycan (CG) and biomimetic collagen-calcium phosphate (CCP) scaffold, are evaluated in rat cranial defects, both cell-free and when cultured with MSCs prior to implantation. The results demonstrate that both cell-free scaffolds showed excellent healing relative to the empty defect controls and somewhat surprisingly, to the tissue engineered (MSC-seeded) constructs. Immunological analysis of the healing response showed higher M1 macrophage activity in the cell-seeded scaffolds. However, when the M2 macrophage response was analysed, both groups (MSC-seeded and non-seeded scaffolds) showed significant activity of these cells which are associated with an immunomodulatory and tissue remodelling response. Interestingly, the location of this response was confined to the construct periphery, where a capsule had formed, in the MSC-seeded groups as opposed to areas of new bone formation in the non-seeded groups. This suggests that matrix deposited by MSCs during in vitro culture may adversely affect healing by acting as a barrier to macrophage-led remodelling when implanted in vivo. This study thus improves our understanding of host response in bone tissue engineering.

  10. On the use of Kodak CR film for quality assurance of needle loading in I-125 seed prostate brachytherapy.

    Science.gov (United States)

    Fog, L S; Nicholls, R; van Doom, T

    2007-09-01

    Low dose rate brachytherapy using implanted I-125 seeds as a monotherapy for prostate cancer is now in use in many hospitals. In contrast to fractionated brachytherapy treatments, where the effect of incorrect positioning of the source in one treatment fraction can be diminished by correcting the position in subsequent fractions, the I-125 seed implant is permanent, making correct positioning of the seeds in the prostate essential. The seeds are inserted into the prostate using needles. Correct configuration of seeds in the needles is essential in order to deliver the planned treatment. A comparison of an autoradiograph obtained by exposing film to the seed-loaded needles with the patient treatment plan is a valuable quality assurance tool. However, the time required to sufficiently expose Kodak XOMAT V film, currently used in this department is significant. This technical note presents the use of Kodak CR film for acquisition of the radiograph. The digital radiograph can be acquired significantly faster, has superior signal-to-noise ratio and contrast and has the usual benefits of digital film, e.g. a processing time which is shorter than that required for non-digital film, the possibility of image manipulation, possibility of paper printing and electronic storage.

  11. How Low Can You Go? Determining a Size Threshold for Implantation of a New Acoustic Transmitter in Age-0 White Sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    Ashton, Neil K.; Liss, Stephanie A.; Walker, Ricardo W.; Brown, Richard S.; Klassen, Cheryl; Backhouse, Stephanie; Bates, Phil; Townsend, Richard L.

    2017-01-01

    Telemetry studies are often used to investigate sturgeon habitat use and movement patterns; however, existing acoustic transmitters are generally too large to implant into age-0 sturgeon without harming the fish. Recent development of a miniaturized acoustic transmitter (cylindrical, 0.7 g in air, 24.2 mm long, 5.0 mm diameter) with up to 365 d battery life has the potential to advance our understanding of age-0 sturgeon ecology in rivers and lakes. Prior to use in field studies, it is essential to conduct experiments evaluating potential adverse transmitter effects on fish. We tested transmitter retention, fish survival, and growth of a broad size range of age-0 white sturgeon (Acipenser transmontanus; 158–277 mm fork length; 26–126 g; 0.6–2.6% transmitter burden) in an 84 d laboratory study, with an ultimate goal of determining a minimum size threshold of sturgeon that can be implanted with this acoustic transmitter. At 84 d post-implantation, transmitter retention and fish survival were 100%. Specific growth rates were reduced at 7 and 14 d post-implantation, resulting in minimum fork length thresholds of 250 and 171 mm, respectively. Juveniles implanted with transmitters regained their growth potential by 28 d post-implantation and no size differences were detected in comparisons with unmarked control fish. This study demonstrates the ability to implant small age-0 sturgeon with high transmitter retention and fish survival, and only minor growth effects. Use of new miniaturized acoustic transmitters may give researchers a means to address questions about young-of-the-year fish recruitment, ecological patterns, and potentially advance conservation management of sturgeon populations.

  12. 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.

  13. Physiologic quality of sweet maize seeds according to thickness and width

    Directory of Open Access Journals (Sweden)

    Claudemir Zucareli

    2014-03-01

    Full Text Available Sweet maize seeds present lower physiologic quality, when compared to regular maize seeds, due to the influence of several features, such as the seed size and shape. Thus, this study aimed at evaluating the seed physiologic quality of two sweet maize cultivars (BR-401 and BR-402, separately classified according to thickness, by using slotted screen sieves (8/64" x 3/4, 9/64" x 3/4, 10/64" x 3/4, 11/64" x 3/4, 12/64" x 3/4 and 13/64" x 3/4, and width, with round screen sieves (17/64", 18/64", 19/64", 20/64", 21/64" and 22/64". For each cultivar, sorted lots were compared with the unrated batch, following a completely randomized design, in a 2x7 factorial scheme, with four replications. The biometric parameters evaluated were sieve retention, 100 seeds weight and water content. The physiologic quality was determined according to the first counting, germination, cold test, accelerated aging, electric conductivity and seedling emergence in the field. The classification with sieves improved the physiologic quality of sweet maize seeds. Seeds with intermediate thickness, for both cultivars, generally presented greater vigor. Concerning width, larger seeds, for the BR-401 cultivar, and intermediate seeds, for the BR-402 cultivar, showed better physiologic quality.

  14. 125I implants as an adjuvant to surgery and external beam radiotherapy in the management of locally advanced head and neck cancer

    International Nuclear Information System (INIS)

    Martinez, A.; Goffinet, D.R.; Fee, W.; Goode, R.; Cox, R.S.

    1983-01-01

    125 I seeds either individually placed or inserted into absorbable Vicryl suture carriers were utilized in conjunction with surgery and external beam radiotherapy in an attempt to increase local control rates in patients with advanced oropharyngeal and laryngopharyngeal cancers (T3-T4, N2-N3), massive cervical lymphadenopathy (N3) and an unknown primary site and locally recurrent head and neck cancers. Forty-eight patients were treated with 55 implants. The carotid artery was implanted in 15 patients, while seven patients had seeds inserted into the base of the skull region, and another three patients had implants near cranial nerves. Eighteen of the 48 patients were treated for cure. The actuarial survival at five years in this subgroup was 50%. The overall local control in the head and neck area was 58%. In this group no patients to date have had a local failure in the implanted volume. Seventeen patients with comparable stage of disease treated prior to 1974 with curative intent without 125 I implants were analyzed retrospectively for comparison with the implanted patients. The actuarial survival of these patients was 18% and the overall head and neck control was 21%. These differences are statistically significant at a P value of 0.01 and 0.007, respectively. Seventeen patients received implants for local recurrence. The local control in the head and neck area was 50%; however, the 2.5 year actuarial survival was only 17%. The complication rate was 11% (six of 55 implants). The improved survival, the high local control, and the minimal complication rates in this series makes the intraoperative implantation of 125 I seeds and effective adjunctive treatment to surgery and external beam irradiation

  15. The Role of Multichannel Marketing in Customer Retention and Loyalty: Study in Emerald Bank Customer in Indonesia

    OpenAIRE

    Ambarwati Ambarwati; Djumilah Zain Hadiwidjojo; Achmad Sudiro; Fatchur Rohman

    2015-01-01

    Attention on the relationship between customer retention, customer loyalty, and customer satisfaction that serves as "seed" of customer loyalty highlight the important factors for multichannel management. With the growing trends of people in investing their money in bank for securities need to be responded by the marketing department to create better marketing strategies. The purpose of this study is to examine and explain the effect of a multichannel bank on emerald customers retention   in ...

  16. Magnetic resonance imaging investigation of the bone conduction implant - a pilot study at 1.5 Tesla.

    Science.gov (United States)

    Jansson, Karl-Johan Fredén; Håkansson, Bo; Reinfeldt, Sabine; Rigato, Cristina; Eeg-Olofsson, Måns

    2015-01-01

    The objective of this pilot study was to investigate if an active bone conduction implant (BCI) used in an ongoing clinical study withstands magnetic resonance imaging (MRI) of 1.5 Tesla. In particular, the MRI effects on maximum power output (MPO), total harmonic distortion (THD), and demagnetization were investigated. Implant activation and image artifacts were also evaluated. One implant was placed on the head of a test person at the position corresponding to the normal position of an implanted BCI and applied with a static pressure using a bandage and scanned in a 1.5 Tesla MRI camera. Scanning was performed both with and without the implant, in three orthogonal planes, and for one spin-echo and one gradient-echo pulse sequence. Implant functionality was verified in-between the scans using an audio processor programmed to generate a sequence of tones when attached to the implant. Objective verification was also carried out by measuring MPO and THD on a skull simulator as well as retention force, before and after MRI. It was found that the exposure of 1.5 Tesla MRI only had a minor effect on the MPO, ie, it decreased over all frequencies with an average of 1.1±2.1 dB. The THD remained unchanged above 300 Hz and was increased only at lower frequencies. The retention magnet was demagnetized by 5%. The maximum image artifacts reached a distance of 9 and 10 cm from the implant in the coronal plane for the spin-echo and the gradient-echo sequence, respectively. The test person reported no MRI induced sound from the implant. This pilot study indicates that the present BCI may withstand 1.5 Tesla MRI with only minor effects on its performance. No MRI induced sound was reported, but the head image was highly distorted near the implant.

  17. 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)

  18. A study on gumbo seed grown in Congo Brazzaville for its food and ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-12-18

    Dec 18, 2006 ... I