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1

Tumor intra-operative interstitial permanent implantation radiation therapy with 125I seeds  

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The therapy of tumor that permanent implantation with 125I seeds could supplied bigger radiation doses for fault tissue to suppress or destroy tissue of tumor effectively. It is a simple and safety treatment. The 125I seeds implantation by guided method mostly is widely used treating prostate cancer abroad today

2

125I seed implantation (permanent brachytherapy) for localized prostate prostate cancer  

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From 1/23/2004 to 11/9/2004, 60 patients with clinically localized prostate cancer were treated using pre-planned 125I Seed permanent transperineal implantation at Okayama University Graduate School of Medicine and Dentistry. We evaluated the efficacy and toxicity for 51 localized prostate cancer patients who were followed up for more than 1 month after 125I Seed implantation brachytherapy. The median patient age was 67 years (range, 53-77 years), the prostatic specific antigen (PSA) value was 8.17 ng/ml (range, 1.13-21.4 ng/ml) and the prostate volume was 23.02 cc (range, 9.3-36.58 cc). The PSA levels decreased in almost all the patients. Although 25 out of the 51 patients complained of difficulty in urination, pollakisuria and/or urinary urgency, which might be associated with radiation prostatitis during the first month after brachytherapy, these symptoms gradually improved. Based on the American Brachytherapy Society (ABS) guidelines, we defined the indications for 125I Seed implantation as low-risk group (PSA<10 ng/ml and Gleason score (GS)?6) or intermediate-risk group (PSA?10 ng/ml or GS?7), with a prostate volume of less than 30 cc by transabdominal ultrasound image. Prostate volume is the most important factor for brachytherapy, since the maximum number of seeds legally allowed is 100 and adequate needle insertion can not be performed in cases where the volume of the prostate is large. (author) (author)

3

Acute urinary morbidity after a permanent 125I implantation for localized prostate cancer  

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We evaluated the predictive factors of acute urinary morbidity (AUM) after prostate brachytherapy. From November 2005 to January 2007, 62 patients with localized prostate cancer were treated using brachytherapy. The 125Iodine (125I) seed-delivering method was a modified peripheral pattern. The prescribed dose was 144 Gy. Urinary morbidity was scored at 3 months after implantation. The clinical and treatment parameters were analysed for correlation with AUM. In particular, in this study, Du90 (the minimal dose received by 90% of the urethra), Dup90 (the minimal dose received by 90% of the proximal half of the urethra on the bladder side) and Dud90 (the minimal dose received by 90% of the distal half of the urethra on the penile side) were analysed. We found that 43 patients (69.4%) experienced acute urinary symptoms at 3 months after implantation. Of them, 40 patients had Grade 1 AUM, one patient had Grade 2 pain, and two patients had Grade 2 urinary frequency. None of the patients had ?Grade 3. Univariate and multivariate analysis revealed that Du90 and Dup90 were significantly correlated with AUM. In this study, Du90 and Dup90 were the most significant predictors of AUM after prostate brachytherapy. PMID:25062753

Ohga, Saiji; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Tatsugami, Katsunori; Sasaki, Tomonari; Nonoshita, Takeshi; Yoshitake, Tadamasa; Asai, Kaori; Hirata, Hideki; Naito, Seiji; Honda, Hiroshi

2014-01-01

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

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

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

2012-04-01

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Nursing care for elderly lung cancer patients treated with CT-guided permanent interstitial co-implantation of 125I seeds and slow-released fluorouracil  

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Objective: To investigate the specific measures and effect of the nursing care for elderly lung cancer patients who were receiving the treatment of CT-guided permanent interstitial co-implantation of 125I seeds and slow-released fluorouracil. Methods: Active care, including adequate preoperative preparation, proper support during operation and postoperative nursing,was carried out for fifty-three elderly patients with lung cancer during their treatment course of CT-guided permanent interstitial brachytherapy with co-implantation of 125I seeds and slow-released fluorouracil. Results: In order to ensure accurate puncture and the smooth particle implantation, the possible conditions which might happen after the procedure were informed to the patients before the surgery and useful advice was given to patients to guide their daily activities. All 53 patients showed no obvious fear before surgery and made good cooperation during the procedure, moreover, they well responded to the therapy and recovered pretty soon. Conclusion: CT-guided permanent interstitial co-implantation of 125I seeds and slow-released fluorouracil is a safe, minimally-invasive and newly-developed technique with reliable effect, which is especially suitable for aged patients. Active and adequate nursing care is essential during the whole therapeutic course. (authors)

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Permanent implantation of 125I seeds combined with GP scheme chemotherapy for non-small cell lung carcinoma in aged patients  

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Objective: To assess the feasibility, safety and curative effect of permanent implantation of 125I seeds combined with GP scheme chemotherapy for the treatment of non-small cell lung carcinoma (NSCLC) in aged patients. Methods: CT-guided permanent implantation of 125I seeds combined with GP scheme chemotherapy was performed in 46 patients with NSCLC, of whom 26 received primary treatment and 20 underwent renewed treatment. During the procedure, 125I seeds were embedded into the tumor in all the patients. Three to five days after the implantation, GP scheme chemotherapy started. GEM (1000 mg/m2) was given (intravenously dripping for 30 min.) on the 1st, 8th and 15th day; DDP (30 mg/m2) was employed on the 1st, 2nd and 3rd day, and recombinant human endostatin (Endostar, 7.5 mg / m2) was administered (intravenously dripping for 3 - 4 hours) from the 1st to the 14th day. Every 28 days completed one treatment course. Two months after 125I seed implantation, at this time the patient had received two courses of treatment, the short-term effect and the toxic side-effect were evaluated. Results: Two months after the 125I particles were embedded in the tumor, all the 46 cases were able to be evaluate for the curative effect. Of 46 patients, complete relief (CR) was seen in 12, partial relief (PR) in 24, stable (SD) in 6 and progression (PD) in 4, with an effective rate of 78.26%. Of 26 patients in thetive rate of 78.26%. Of 26 patients in the primary treatment group, CR was obtained in 7, PR in 15, SD in 3 and PD in 1, with an effective rate of 84.6%. Of 20 patients in the renewed treatment group, CR was seen in 5, PR in 9, SD in 3 and PD in 3, with an effective rate of 70.0%. Conclusion: Permanent implantation of 125I seeds combined with GP scheme chemotherapy is an effective, safe and feasible treatment for NSCLC in aged patients. (authors)

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

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Purpose: To compare the urethral and prostate absolute and biologic effective doses (BEDs) for 131Cs and 125I prostate permanent implant brachytherapy (PPI). Methods and Materials: Eight previously implanted manually planned 125I PPI patients were replanned manually with 131Cs, and re-planned using Inverse Planning Simulated Annealing. 131Cs activity and the prescribed dose (115 Gy) were determined from that recommended by IsoRay. The BED was calculated for the prostate and urethra using an ?/? ratio of 2 and was also calculated for the prostate using an ?/? ratio of 6 and a urethral ?/? ratio of 2. The primary endpoints of this study were the prostate D90 BED (pD90BED) and urethral D30 BED normalized to the maximal potential prostate D90 BED (nuD30BED). Results: The manual plan comparison (?/? = 2) yielded no significant difference in the prostate D90 BED (median, 192 Gy2 for both isotopes). No significant difference was observed for the nuD30BED (median, 199 Gy2 and 202 Gy2 for 125I and 131Cs, respectively). For the inverse planning simulated annealing plan comparisons (?/? 2), the prostate D90 BED was significantly lower with 131Cs than with 125I (median, 177 Gy2 vs. 187 Gy2, respectively; p = 0.01). However, the nuD30BED was significantly greater with 131Cs than with 125I (median, 192 Gy2 vs. 189 Gy2, respectively; p = 0.01). Both the manual and the inverse planning simulated annealing plans resulted in a significantly lower prostate D90 BED (p = 0.01) and significantly greater nuD30BED for 131Cs (p = 0.01), compared with 125I, when the prostate ?/? ratio was 6 and the urethral ?/? ratio was 2. Conclusion: This report highlights the controversy in comparing the dose to both the prostate and the organs at risk with different radionuclides

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

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

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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  

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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 (125I or 103Pd) 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 125I with activities ranging from 0.3 to 0.7 mCi, and for 103Pd 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 125I 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 t 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 103Pd, 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 125I than for 103Pd implants. Conclusions: For both isotopes, the lower activities studied systematically result in lower EIs. If seeds can be placed within approximately 0.5 cm of their intended position 103Pd should be preferred because its EI is lower than that of 125I. For all activities the coverage indices and D90 are within the required range. If seed placement uncertainties are larger than 0.5 cm, 125I provides slightly better target coverage; however, in terms of external volume (healthy tissue) covered, 103Pd is superior to 125I

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Implant quality and acute urinary toxicity with 125I permanent seed implantation for clinically localized prostate cancer. Results of the first 30 patients treated at PMCC  

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It is widely recognized that a steep learning curve exists for departments initiating a prostate low-dose radiation (LDR) implant service. Appropriate team credentialing, willingness to accept mentoring and attention toward ongoing QA initiatives are required to ensure that both clinical and dosimetric endpoints consistently achieve standards deemed appropriate. The department of urological services began a prostate seed service in 4/2002. All participating staff were suitably trained in Seattle, Washington with unit protocols based on standard trans-rectal sonographic pre-planning, modified peripheral loading, prescription dose 145Gy and 4 week CT based post implant dosimetry. Patient eligibility paralleled federal medicare guidelines with men presenting with favorable risk disease, gland volumes 15ml/sec) considered potential candidates. a) Presenting Demographics: (n=30) Median age 62 (41-73), T stage 1c:2a:2b:2c = 18:10:1:1, Median PSA 6.3ng/ ml (5.1ng/ml - 11.1ng/ml), Median IPSS 5 (0-12), Mean Qmax 18ml/s (10ml/s -35ml/s).; b) Acute toxicity: No significant peri-procedural complications. One patient developed urinary retention day 3 and was successfully trialed day 10. All patients experienced some degree of sub-acute urinary irritation although three patients followed for at least 12 months have returned to their baseline level of functioning. c) Post implant Dosimetry: Median D90 139Gy) Post implant Dosimetry: Median D90 139Gy (104Gy - 190Gy). 3 Patients received a D90 < 90% with one at 104Gy receiving additional 'top-up' external beam radiation (20Gy). A definable improvement in implant quality was observed over the 12 month study interval. Although acute toxicity was considered acceptable, patients do experience a sub-acute period of low grade albeit persistent urinary irritation and need to be cautioned appropriately. A high level of implant quality was achieved in the majority of patients. Despite 5 years HDR brachytherapy experience, considerable refinement in technique and approach was required in order to achieve consistent high level results

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The clinical application of 125I radionuclide implantation in tumor therapy  

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Objective: To investigate the safely and clinical efficacy of permanent implantation of 125I radioactive particle in the surgery of malignancies such as brain tumors, liver cancer, cholangiocarcinoma, lung cancer, prostate cancer and malignant teratoma. Methods: Thirty eight patients proved by puncture biopsy, histology or cytology were retrospectively analyzed. Three-D images of the tumor were reconstructed using treatment planning system (TPS), the number and the dose rate distribution of 125I seeds were calculated. The matched peripheral dose of 125I seeds implantation was 60?130 Gy, the number of 125I seeds implanted ranged from 6?40 per lesion, and the median amount of implanted 125I seeds were 23. Results: Twelve months followup after the therapy showed 9 cases of complete relief, 24 cases of partial relief and 5 cases of no change. The overall effective rate (complete relief + partial relief) of 12 months was 86.8%. Conclusion: Permanent implantation of 125I radioactive particle in the surgery of malignancies treatment is a safe, effective treatment for tumors. (authors)

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Spacing nomograph for interstitial implants of 125I seeds  

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Permanent implants of 125I seeds at Memorial Sloan-Kettering Cancer Center are performed by the method of ''dimension averaging'' to determine the total activity to be implanted; that is, the activity (in mCi) is taken to be five times the average dimension (in cm) of the target region. A nomograph has recently been developed to permit a rapid calculation of the seed spacing required for a uniform distribution of the number of seeds specified by dimension averaging. The number of seeds is also given by the nomograph. The spacing calculation performed with the nomograph, since it involves the two-thirds power of average dimension and the one-third power of seed strength, is well beyond the reach of mental arithmetic. Elongation and shape corrections are included. The nomograph spacing result is valid for an equipartition of measured volume among seeds but must be increased by an easily determined factor if peripheral seeds are considered to define the surface of the target region

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First symposium seed implant 125I and high rate of prostate  

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The First symposium seed implant 125I 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 125I seeds; high doses radiation in radiotherapy; brachytherapy for prostate cancer; prostate implant technique with 125I seeds; implant dosimetric aspects; radioprotection of 125I seeds.

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

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

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CT-Guided Radioactive 125I Seed Implantation Therapy of Symptomatic Retroperitoneal Lymph Node Metastases  

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PurposeThis study explored the clinical efficacy of CT-guided radioactive 125I seed implantation in treating patients with symptomatic retroperitoneal lymph node metastases.MethodsTwenty-five patients with pathologically confirmed malignant tumors received CT-guided radioactive 125I seed implantation to treat metastatic lymph nodes. The diameter of the metastatic lymph nodes ranged from 1.5 to 4.5 cm. Treatment planning system (TPS) was used to reconstruct the three-dimensional image of the tumor and then calculate the corresponding quantity and distribution of 125I seeds.ResultsFollow-up period for this group of patients was 2–30 months, and median time was 16 months. Symptoms of refractory pain were significantly resolved postimplantation (P 125I seed implantation, which showed good palliative pain relief with acceptable short-term effects, has proved in our study to be a new, safe, effective, and relatively uncomplicated treatment option for symptomatic retroperitoneal metastatic lymph nodes

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Comparison of 3 different postimplant dosimetry methods following permanent 125I prostate seed brachytherapy  

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

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

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

Marcu, Loredana G., E-mail: loredana@marcunet.com [Department of Medical Physics, Royal Adelaide Hospital, South Australia (Australia); Faculty of Science, University of Oradea (Romania); School of Chemistry and Physics, University of Adelaide, South Australia (Australia); Gowda, Raghu [Department of Radiation Oncology, Royal Adelaide Hospital, South Australia (Australia)

2013-10-01

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Evaluation of 125I seed implantation combined with arterial infusion chemotherapy in treating unresectable lung cancer  

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Objective: To assess the therapeutic effect of CT-guided 125I seed implantation combined with arterial infusion chemotherapy in treating unresectable lung cancer. Methods: Thirty patients with unresectable non-small call lung cancer were randomly divided into two groups. Group A (study group,n = 14)was receiving arterial infusion chemotherapy one week before and one week after 125I seed implantation. Group B (control group, n = 16) was receiving 125I seed implantation only. Two months after 125I seed implantation, follow-up checkup with thoracic CT scanning was carried out in all patients. The response to treatment was evaluated in accordance with RECIST criteria and the accumulated survival rate was analyzed by means of Kaplan-Meier. Results: Scheduled treatment was completed in all 30 patients. Under CT-guidance, 552 125I seeds were implanted in the patients of group A, while 603 125I seeds were implanted in the patients of group B. Nine patients in group A received two times of arterial infusion chemotherapy. Follow-up CT examination showed that the case number of complete remission, partial remission,stabilized disease and progressive disease in group A was 0, 10, 4 and 0 respectively, with an overall response rate of 71.43%. The corresponding data in group B was 0, 10, 5 and 1 respectively, with an overall response rate of 62.5%. The difference in the response rate between two groups was of no statnse rate between two groups was of no statistical significance (P > 0.05). The one-year survival rate of group A and B was 78.6% and 62.5% respectively, the difference between the two groups was statistically significant (P 125I seed implantation combined with arterial infusion chemotherapy is an effective treatment for unresectable lung cancer, it can significantly prolong the patient's survival time. (authors)

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Urethral dosimetry constraints in 125I permanent prostate brachytherapy used as boost to external radiotherapy; Restricciones dosimetricas de la uretra en el caso de braquiterapia permanente de prostata con 125I utilizada como complemento a radioterapia externa  

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With 125I monotherapy in permanent brachytherapy implants, the recommendation is to deliver to the urethra less than 150% of the prescribed dose, 145 Gy, that is a limit of 217.5 Gy. However, there are not recommendations in the case of the brachytherapy boost. At our hospitals, permanent brachytherapy implants are used as a 108 Gy boost in intermediate risk patients with prostate carcinoma, which have undergone an external beam radiotherapy course ranging between 45 and 50.4 Gy. The purpose of this work is to present a simple radiobiologically-based analysis performed in order to obtain the urethral dose limit in permanent prostate brachytherapy boost. The linear-quadratic model has been used to determine the biologically effective dose, analysing the results for different dose/fraction, t1/2 and a/b values. Assuming 46 Gy delivered by external beam radiotherapy, it is found that a limit value of 145 Gy, corresponding to the isodose level of 135% of the prescribed dose, is adequate. The results for a ten patients sample are shown in order to illustrate the values that are obtained in clinical practice. In conclusion, we present the method employed to find the urethral dose limit in the case of the combination of external beam radiotherapy and permanent 125I seeds brachytherapy boost implants (Author).

Lliso, F.; Perez-Calatayud, J.; Carmona, V.; Guirado, D.; Munoz, M.; Richart, J.; Ballester, F.; Granero, D.; Rodriguez, S.; Tormo, A.; Santos, M.

2010-07-01

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125I prostate implants: automatic optimization of dose distribution using fast simulated annealing  

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Purpose/Objective: To automatically determine seed and needle numbers and dispositions within the target volume to achieve optimized dose distribution of transperineal 125I permanent implants. Materials and Methods: Target volume is initially determined from a set of ultrasound (or CT) transverse slices. Clinical criteria describing implant quality are expressed by a mathematical cost function. The first term of cost function takes into account the minimum peripheral prescribed dose on the prostate contours. The second term insures dose uniformity throughout the volume. Finally, the third term, analogous to a cristal potential, governs the transverse needle scheme distribution and minimizes their numbers. The last term also adds penalties on needles located too close to each other or containing only one seed. To begin the optimization, the user defines all possible needle positions covering the entire prostate at each 0.5 cm on the transverse template, except in the vicinity of the urethra which is devoided of needles. Then, the program starts and an initial number of seeds is randomly distributed within the allowed needle positions. The simulated annealing algorithm allows seed and needle positions to be varied and their number reduced to optimize the cost function. Results: Proper weightings between the three terms of the cost function were determined emperically and use to perform the dose optimization. The optimization has been used in the planning of 5ization has been used in the planning of 50 patients with prostate volume ranging from 19 to 56 cc (median 33 cc). For an average size prostate, the optimization can be completed within 50000 iterations, approximately 45 minutes on a Sun SPARC5 workstation. The obtained dose distribution is characterized by the prescribed isodose following the shape of the prostate contours with a proper margin. The prostate DVH for the prescribed dose is generally larger than 98 %. Conclusion: The use of a cost function closely related to the clinical criteria and fast simulated annealing allow for consistent and automatic determination of seed and needle distributions resulting in an optimized dose distribution customized for each patient and independent of the dosimetrist experience. The algorithm has been fully implemented clinically and was used for the planning of 50 patients treated for prostate cancer with transperineal 125I permanent prostate implants. The outcome is a better dose distribution and obtained much faster than what can be achieved without automation

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CT-guided radioactive seed 125I implantation for the treatment of malignant adrenal neoplasms  

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Objective: To evaluate CT-guided radioactive seed 125I implantation in treating malignant adrenal neoplasms. Methods: CT-guided radioactive seed 125I implantation was performed in 9 cases of malignant adrenal neoplasms with a total of 9 lesions. The clinical data were retrospectively analyzed. Treatment plan system was used to design the distribution of 125I seeds for treatment. Under CT guidance, the 125I seeds of 29.6 MBq were implanted into the malignant adrenal neoplasms with an interval distance of 1.0-1.5 cm. A follow-up of 1-15 months was conducted. The postoperative efficacy was evaluated with enhanced CT scanning. Results: After the treatment, complete remission (CR) was obtained in 5 patients, partial remission (PR) in 3 patients and no change (NC) in 1 patients, with an overall effective rate of 88.9%. The main complication was slight bleeding (n=1). Conclusion: For the treatment of malignant adrenal neoplasms, CT-guided radioactive seed 125I implantation carries reliable short-term effectiveness, therefore, it is a safe, effective and minimally-invasive therapy. (authors)

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

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

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The clinic application of CT-guided interstitial 125I seeds implantation in curing lung cancer  

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Objective: To introduce the procedures and evaluate the clinic value of CT-guided interstitial 125I seeds implantation in treating lung cancer. Methods: Thirty-one cases patients with lung cancer underwent CT-guided interstitial 125I seeds implantation. All patients were scanned on multi-spiral CT (Philips, MX 8000) with optical navigating system (pinpoint), and treatment plan system, needle, and 125I seeds (Chinese Academy of Science) were used. First of all, according to the size of tumor, TPS calculated the optimal quantity of seeds. Then, under the guidance of CT, 125I seeds were percutaneously implanted into the tumors for interstitial radiotherapy. CT follow-up examinations were performed 1, 2, and 6 months after the therapy, respectively. According to the size of tumor, curative effects were graded as 4 grades: grade I: obvious relief (OR) (the size of tumor reduced up to 50%), grade II: relief (PR) (the size of tumor reduced by 25%-50%), grade III: slight relief (SD) (the size of tumor reduced by 1%-25%), and grade IV: no effect (PD) (the size of tumor did not reduce or increase, and clinic symptoms showed no relief). Results: At 1 month, 9 cases were classified as grade I, 6 as grade II, 13 as grade III, and 3 as grade IV, respectively. At 2 months, 17 cases were grade I, 8 grade II, 3 grade III, and 3 grade IV, respectively. At 6 months, 23 cases were grade I, 3 grade II, 2 grade III, and 3 grade IV, respectively. grade III, and 3 grade IV, respectively. Conclusion: CT-guided interstitial 125I seeds implanted was a safe, reliable, and effective curative method for lung cancer. (authors)

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Clinical impact of implementing the recommendations of AAPM Task Group 43 on permanent prostate brachytherapy using 125I  

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Purpose: To determine the clinical impact upon permanent interstitial prostate 125I brachytherapy after conversion to AAPM Task Group 43 (TG 43) guidelines. Methods: The value of quantities used in the calculation of dose from two institutions, Northwest Tumor Institute (NWTI) and Memorial Sloan-Kettering Cancer Center (MSKCC), which pioneered interstitial techniques for prostate brachytherapy were compared to those recently determined and published by TG 43 of the American Association of Physicists in Medicine (AAPM). Using two different weighting schemes, the change in the commonly prescribed reference dose of 160 Gy was determined and found to be in agreement with that recently suggested. Volumes encompassed by the reference isodose surface were determined from a single source implant and a regularly distributed implant to show the effect of change in reference dose. A comparative analysis on 10 patients was performed to show how this change affected common implant quality descriptors and the effect of changing the calculation formalism without changing the reference dose. Results: Both weighting schemes suggested a change in reference dose from 160 to 144 Gy. Single-source and distributed-source volumetric analysis confirmed this value. The effect on commonly used conformity and uniformity quantifiers for 10 implant patients was tabulated. Conclusion: Upon adopting the recommendations suggested by TG 43, institutions that perform permanent 125125I prostate implants using calculation methods adapted from the NWTI or MSKCC should revise their treatment prescriptions from 160 to 144 Gy so that the doses delivered to patients remain unaffected. Institutions using other techniques to calculate dose should conduct an analysis similar to the one detailed here

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

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

Mazeron Renaud

2012-03-01

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Comparison between two 125I brachytherapy implant techniques. Preplanning and intraoperative method. Dose escalation deteriorate acute morbidity?  

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We compared two world-widely used permanent 125I seed implant techniques preplanning and intraoperative planning, based on post-implant dosimetry and acute toxicity. We reported results of a detailed post-implant dosimetric evaluation and comparison of acute toxicities between 122 consecutive patients with prostate adenocarcinoma treated by the preplanning methodology and 122 patients treated with the intraoperative, interactive seed implant method according to Mount Sinai Medical Center. Baseline parameters were similar in both groups. On day 30 post-implant CT, mean D90, expressed as minimal dose covering 90% of the gland volume was 155 Gy for the preplanned group and 172 Gy for the intraoperative group (P<0.01). Based on day 1 and 30 post-implant CT, most of urethral and rectal dosimetric parameters were similar between two groups. Acute morbidity, assessed by the Common Terminology Criteria for Adverse Events v3.0, was minimal in both groups and did not correlate with the technique employed. This comparison of implant adequacy favors this particular intraoperative method. While dose parameters of prostate was significantly better with the intraoperative method, no increased short-term morbidity was noted. Longer-term clinical outcome should substantiate our contention of the superiority of the intraoperative method. (author)

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CT guided radioactive seed 125I implantation in treating hilar hepatic tumor and metastatic lymph nodes  

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Objective: To investigate the clinical value of CT guided radioactive seed 125I implantation in treating hilar hepatic tumor and metastatic lymph nodes. Methods: 32 patients with pancreatic cancer accepted CT guided radioactive seeds 125I implantation were enrolled in this study. The average tumor dimension was 4.2 cm. In this series, there were 8 cases of hepatocellular carcinoma, 12 cases of hilar cholangio carcinoma, 6 cases of hepatic metastasis and 6 of hepatic hilar tumor and metastatic lymph nodes. Among these patients, 14 cases had cholangiectasis and 22 cases had cirrhosis. Under CT guidance, 125I seeds of 0.6-0.9 mCi were implanted into the pancreatic cancer at a distance of 1.0-1.5 cm according to TPS. Results: Two cases died on account of metastasis and three died through liver function failure. Among CT followed-up of 32 patients in 2 months, 2 obtained CR, 20 obtained PR, 5 NC and 5 PD. The responsive rate was 68.8%. The side effects occurred during the procedure including pneumothorax in 1 case with lung compression less than 30%; 7 seeds migration in liver and 3 seeds in lung. WBC decreased slightly in 1 cases during 2 months follow up. No massive bleeding, biliary fistula, intestinal fistula, intestinal hemorrhage, acute pancreatitis, enterorrhagia and intra-abdominal abscess were encountered. Conclusions: CT guided radioactive seed 125I implantation procedure is a safe and effective method in treating hilarafe and effective method in treating hilar hepatic tumor and metastatic lymph nodes with good clinical effects of minimal damage and few complications. (authors)

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CT-guided 125I radioactive seeds implantation and chemical ablation for malignant retroperitoneal tumors  

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Objective: To explore the clinical value of CT-guided 125I radioactive seeds implantation and chemical ablation for malignant retroperitoneal tumors. Methods: Because of the rejection of the second surgery resection and insensitivity of chemotherapy and radiotherapy, nineteen patients with recurrent or metastasis malignant retroperitoneal tumors were treated by CT-guided 125I radioactive seeds implantation according to TPS or Halarism's experienced function, and percutaneous ethanol injection was performed if the way of punctuation was limited. The extent of pain relief was assessed one month later after therapy. All the patients received enhanced CT scan 6 months after the first treatment, and imaging evaluation was performed according to WHO criteria. Results: For the 19 patients, pain relief was achieved more or less in all patients. Imaging evaluation revealed complete relief, partial relief, no change in 10, 7, 2 cases respectively. All patients are still alive now. The longest followed span is 31 months, and the shortest is 7 months, the average followed span is 13.5 months. Conclusion: CT-guided 125I radioactive seeds implantation and chemical ablation are effective for malignant retroperitoneal tumors. (authors)

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

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

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Pathological impairments induced by interstitial implantation of 125I Seeds in spinal canal of banna mini-pigs  

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Background Use a banna mini-pig to set up 125I implantation model, and investigate the consequence of radiation-related impairments. Methods In present study, 125I seeds were implanted into spinal canal of T13 level of spine in banna mini-pigs. After operation, the pigs were raised up to 8 months, behavior changes were recorded within this period. After 8 months, spinal cords were collected for pathological analysis. Results In this study, a 125I brachytherapy animal model had been successfully established, in the model group, the banna pigs' Tarlov scale decreased from 5 to 2.57 ± 0.36, significant cellular impairments were noted by pathological analysis. Conclusions Without any protection and operation improvement, 125I implantation can cause serious histological impairments and moving difficulty for banna mini-pigs; this present research provides an alternative tool to study spinal 125I brachytherapy. PMID:22390740

2012-01-01

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Pathological impairments induced by interstitial implantation of 125I Seeds in spinal canal of banna mini-pigs  

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Full Text Available Abstract Background Use a banna mini-pig to set up 125I implantation model, and investigate the consequence of radiation-related impairments. Methods In present study, 125I seeds were implanted into spinal canal of T13 level of spine in banna mini-pigs. After operation, the pigs were raised up to 8 months, behavior changes were recorded within this period. After 8 months, spinal cords were collected for pathological analysis. Results In this study, a 125I brachytherapy animal model had been successfully established, in the model group, the banna pigs' Tarlov scale decreased from 5 to 2.57 ± 0.36, significant cellular impairments were noted by pathological analysis. Conclusions Without any protection and operation improvement, 125I implantation can cause serious histological impairments and moving difficulty for banna mini-pigs; this present research provides an alternative tool to study spinal 125I brachytherapy.

Yang Zuozhang

2012-03-01

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

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

Wang, Zhongmin, E-mail: wzm0722@hotmail.com [Shanghai Jiaotong University School of Medicine, Department of Nuclear Medicine, Renji Hospital (China); Lu, Jian; Gong, Ju; Zhang, Liyun [Shanghai Jiaotong University School of Medicine, Department of Radiology, Ruijin Hospital Luwan Branch (China); Xu, Yingjia [Shanghai Jiao Tong University, Department of Cardiology, Shanghai Chest Hospital (China); Song, Shaoli [Shanghai Jiaotong University School of Medicine, Department of Nuclear Medicine, Renji Hospital (China); Chen, Kemin [Shanghai Jiaotong University School of Medicine, Department of Radiology, Ruijin Hospital (China); Liu, Fenju [Soochow University, School of Radiation Medicine and Public Health (China); Gang, Huang, E-mail: huanggang0722@hotmail.com [Shanghai Jiaotong University School of Medicine, Department of Nuclear Medicine, Renji Hospital (China)

2013-04-12

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Linear 125I seeds strand implantation combined with biliary stenting for the treatment of malignant biliary obstruction  

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Objective: To evaluate the therapeutic efficacy of linear 125I seeds strand implantation combined with biliary stenting in treating malignant biliary obstruction. Methods: Linear 125I seeds strand implantation combined with biliary stenting was carried out in 28 patients with malignant biliary obstruction. The technical success rate, the clinical efficacy, the postoperative complications and the survival rate were analyzed. Results: Both biliary stenting and 125I seeds strand implantation were successfully accomplished in all patients. No serious complications occurred. After the procedure the biliary obstruction symptoms were markedly improved and the bilirubin level was significantly reduced (P125I seeds strand implantation together with biliary stenting is safe and effective although its long-term efficacy needs to be further studied. (authors)

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

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

Gan, Zhen; Jing, Jian; Zhu, Guangyu; Qin, Yonglin; Teng, Gaojun; Guo, Jinhe

2015-05-01

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

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

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

2015-01-01

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125I interstitial brachytherapy for primary malignant brain tumors: technical aspects of treatment planning and implantation methods  

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Use of interstitial radiation holds promise in the treatment of primary malignant brain tumors, but optimal technical factors have yet to be determined. We have developed a method of precise CT directed stereotactic placement of radioactive sources in a predetermined target volume. We use low activity (1-2 millicurie/speed) sources of 125I loaded in silastic catheters, which are positioned in a parallel array in the target. Positioning of such multiple sources toward the periphery of the volume enhances achievable dose homogeneity. Seeds of various activities can be differentially loaded into each catheter and the catheters can be positioned at various radii from the central target so that the treated volume corresponds to the identified (often irregular) target volume. Although the implant is designed to be permanent, the sources can be removed easily in a second procedure

37

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

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Objective: To evaluate the therapeutic effect and safety of CT-guided interstitial 125I seed implantation in treating intractable pelvic recurrence of rectal carcinomas. Methods: During the period from April 2010 to September 2010 CT-guided interstitial 125I 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 (P125I 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)

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

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Objective: to assess the clinical value of the combined treatment of transcatheter arterial chemoembolization (TACE), CT-guided radiofrequency ablation (RFA) and radioactive 125I 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 125I seed implantation. With the help of treat plan system (TPS), the radioactive 125I seed implantation was conducted to make additional management for the same lesion when RFA was finished, or the radioactive 125I 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 125I seeds in 1 case. Conclusion: The combined treatment of TACE and CT-guided RFA together with 125I seed implantation is a safe, reliable and effective therapy for HCC with excellent short-term result. (authors)

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Clinical application of CT-guided 125I seed interstitial implantation for recurrent rectum carcinoma  

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Objective: To explore the safety and clinical efficacy of CT-guided radioactive seed implantation in treating recurrent rectum carcinoma. Methods: CT-guided 125I radioactive seed implantation was carried out in 20 patients with recurrent rectal carcinoma. Treatment planning system was used preoperatively to reconstruct three dimensional image of the tumor and to calculate the estimated seed number and distribution. The tumor matched peripheral dose (MPD) of the radioactive seeds was 80-130 Gy. The radioactivity of the seeds was 0.5-0.8 mCi / seed and the median implanted seeds was 48(range 25-95) in number. CT scan was made immediately after the implantation to check the quality of the seeds. Change of pain score, tumor size and complications were recorded during the follow-up period. Results: Twenty cases composed of 12 males and 8 females,aged 38 to 78 years (median age of 62 years). The follow-up period lasted 2-28 months. On an average, 3 to 7 days after the procedure patients experienced significant pain relief. CT scan performed 2 months after the procedure revealed that complete relief (CR) of the tumor was seen in 2 cases, partial relief (PR) in 13 cases, no change (NC) in 3 cases and progression (PD) in 2 cases. The total effective rate (CR + PR) was 75%. The median survival time was 18.8 months. The survival rate of 1 and 2 years was 75% and 25% respectively. Two cases died of tumor deterioration and 3 cases died of extensive metastases. No complies died of extensive metastases. No complications such as frequent micturation, pain on urination and hematuria occurred during the follow-up period. Conclusion: CT-guided 125I radioactive seed implantation is a safe and effective interventional treatment for recurrent rectal carcinoma with reliable short-term efficacy and excellent anti-pain effect. (authors)

40

CT-guided 125I seed implantation for the treatment of advanced pancreatic carcinoma: a clinical therapeutic analysis  

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Objective: To explore the clinical efficacy of CT-guided 125I seed interstitial implantation for the treatment of advanced pancreatic carcinoma. Methods: During the period from June 2006 to June 2008 in authors' hospital, CT-guided 125I interstitial implantation was carried out in 14 patients (9 males and 5 females with a mean age of 69.5 years) with unresectable advanced pancreatic carcinoma. The clinical data were retrospectively analyzed. Before the procedure treatment planning system was used to reconstruct 3-dimensional images of the tumor and to calculate the quantity and total activity of 125I seeds needed for the individual. Under CT guidance 125I seeds were implanted into the pancreatic tumor. The activity of 125I seed used in treatment was (0.5-0.8) mCi, the interval distance between implanted seeds was (0.6-1.0) cm. When puncturing the tumor, the vessels, pancreatic duct, intestinal loop (especially colon) and adjacent important structures should be prevented from damage. A follow-up lasting for 2?18 months was conducted. The therapeutic results were analyzed. Results: Three to seven days after implantation the pain was relieved. Follow-up CT performed two months after implantation showed that complete remission (CR) was obtained in 1 case, partial remission (PR) in 8 cases, no change (NC) in 3 cases and progressive deterioration (PD) in 2 cases. The overall effective rate (CR+PR) was 64.3%. The survival time of patients ranged from 5 to 18 months, with a median survival time of 10 months. No serious complications, such as pancreatitis, intestinal hemorrhage, radiation colitis, etc. occurred. Conclusion: For the treatment of advanced pancreatic carcinoma, interstitial implantation of 125I seeds has reliable effect in reliving pain and quite satisfactory short-term efficacy. The another advantage of this technique is minimally-invasive with few complications. (authors)

41

Radiotoxicity of 125I-iododeoxyuridine in pre-implantation mouse embryos  

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The radiotoxicity of DNA incorporated 125I in cultured pre-implantation two-cell mouse embryos was investigated and compared with external ?-irradiation. The uptake of 125IdU in the two-cell stage embryos was determined as a function of incubation time and concentration of radioactivity (MBq/ml) in the medium. The absorbed dose to the embryos was calculated using conventional procedures. The embryos survival curves show that the dose at 37% survival is only about 15 cGy for 125IdU, whereas for 137Cs-photons it is 175 cGy. The extreme toxicity observed is thought to be due to the localized energy deposition of the numerous low energy Auger electrons emitted in the decay of 125I. These results are consistent with earlier observations in mouse testis and cultured cells and point to the need for assessing the radiation risk from incorporated Auger electron emitting radionuclides based on their subcellular distribution. (author)

42

125I seeds implant combined with internal iliac arterial infusion chemotherapy in the treatment of recurrence pelvic malignant tumors  

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Objective: To explore the clinical value of seeds implantation technique under CT guidance, combined with internal iliac arterial infusion chemotherapy in the treatment of recurrence pelvic tumors. Methods: Eight patients with recurrence pelvic tumors have been treated by 125I seeds implant combined with internal iliac arterial infusion chemotherapy. The chemotherapy scheme was based on the primary tumor type. Under CT guidance, 125I seeds were implanted into the pelvic tumors according to TPS or Halarism's experienced function: mCi = Da x 5 (Da means the average of length, width and height of the lesion). mCi is the total activity of 125I. The number of 125I seeds needed equals to that of total activities divided by the activity of single particle. Results: All the patients received PET-CT chest follow up two months later. CR, PR, NC, PD were abtained in 0, 5, 2, 1 cases respectively. Two patients died within one year, other 6 patients are still alive, the longest survival period was more than 15 months, the 1-year survival rates was 75%. Conclusions: 125I seeds implant combined with internal iliac arterial infusion chemotherapy is an effective method in the treatment of pelvic recurrence tumors. (authors)

43

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

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Objective: To discuss the nursing care strategy for patients with local recurrent rectal cancer who has been treated with CT-guided 125I 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 125I seed occurred. Conclusion: For patients with local recurrent rectal cancer occurred after CT-guided 125I seed implantation therapy, careful nursing can effectively relieve the pain and anxiety feeling,and the living quality can also be markedly improved. (authors)

44

Characterization of some dosimetric parameters of 125I seeds used for prostate implants using Monte Carlo simulations  

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In the prostate cancer treatment, there is an increasing interest in the permanent radioactive seeds implant technique, where 125I seeds are inserted into the patient's prostate, allowing the delivery of high doses and preserving nearby organs at risk. For the calculation of dose distributions, treatment planning systems (TPS) makes use of the calculation proposed by the protocol TG-43. According to the document, data of dose distribution should be made more precise, either experimentally or by computational simulations, to be used in the TPS. Several authors used Monte Carlo simulations to generate the parameters of brachytherapy sources (seeds) that are recommended by TG-43 protocol, which are used for dose calculations in the TPS. For a single seed, there are variations in the geometry chosen to calculate the dosimetric parameters recommended and in the medium where the dose distributions are calculated (liquid water or solid water) and also in the Monte Carlo code used. The TPS consider the sources as point entities and do not consider the attenuation effects among the seeds. In this work, computational simulations of the geometry of one of the most used seeds in permanent prostate implants, the Amersham model 6711, were performed through the Monte Carlo method using the MCNP5 code. The dosimetric parameters radial dose function g(r) and anisotropy function F(r,?) were simulated and the results show good agreement with other works. This model can be used in the future to study the impact of the approaches and other problems in the implant procedure. (author)

45

Safety evaluation in vicinity during and after 125I seeds implantation in head and neck region  

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Objective: To measure the radiation dose during and after 125I seeds implantation in head and neck region, and to evaluate the radiation safety in the vicinity. Methods: Forty patients who had 125I seeds implanted in head and neck region were divided into two groups as facial and neck group as well as intra-oral group. The radiation doses were measured at the distance of 30 cm in three different directions during operation and at the distances of 30, 50, and 100 cm after operation when the patients opened and closed their mouth, respectively. Results: The radiation dose rate on the treatment side [(2.60±0.37) ?Sv] was higher than that on the other two sides [(0.28±0.05) and (0.15±0.03 ?Sv)] during the operation, with the statistical difference (t=25.62, 29.51, P0.05). On the treated side at all the distances of 30, 50, and 100 cm, the radiation dose rates were higher in the facial and neck group [(66.28±3.31), (35.06±3.05) and (1.72±0.17) ?Sv/h] than those in the intra-oral group [(52.46±3.54), (20.78±2.01.46±3.54), (20.78±2.01) and (1.55±0.13) ?Sv/h], with the statistical difference (t=12.74, 15.51, 3.69, P<0.05). At the distance of 100 cm, the radiation dose rates were (1.72±0.17) ?Sv/h in facial and neck group, (1.55±0.13) ?Sv/h when which was safe for the public. Conclusions: Radiation exposure to the medical workers and the public from the patients is very low. It is easy to achieve the radiation safety by reducing the exposure time, increasing the distance and changing the exposure direction. (authors)

46

Prescription dose in permanent 131Cs seed prostate implants  

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Recently, 131Cs seeds have been introduced for prostate permanent seed implants. This type of seed has a relatively short half-life of 9.7 days and has its most prominent emitted photon energy peaks in the 29-34 keV region. Traditionally, 145 and 125 Gy have been prescribed for 125I and 103Pd seed prostate implants, respectively. Since both the half-life and dosimetry characteristics of 131Cs seed are quite different from those of 125I and 103Pd, the appropriate prescription dose for 131Cs seed prostate implant may well be different. This study was designed to use a linear quadratic radiobiological model to determine an appropriate dose prescription scheme for permanent 131Cs seed prostate implants. In this model, prostate edema was taken into consideration. Calculations were also performed for tumors of different doubling times and for other related radiobiological parameters of different values. As expected, the derived prescription dose values were dependent on type of tumors and types of edema. However, for prostate cancers in which tumor cells are relatively slow growing and are reported to have a mean potential doubling time of around 40 days, the appropriate prescription dose for permanent 131Cs seed prostate implants was determined to be: 127-12+5Gy if the experiences of 125I seed implants were followed and 121-3+0 were followed and 121-3+0Gy if the experiences of 103Pd seed implants were followed

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

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Objective: To research radiation protective nursing intervene and important notice of 125I 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, 125I 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 125I 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 125I 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)

48

Permanent and removable implants for the brachytherapy of brain tumors  

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

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The implantation of esophageal stent with radioactive 125I particles for advanced esophageal carcinomas: observation of therapeutic results  

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Objective: To investigate the therapeutic effect of the implantation of esophageal stent with radioactive 125I particles in treating advanced esophageal carcinomas in aged patients. Methods: During the period from Sep. 2009 to Dec. 2010, implantation of esophageal stent was used to treat 43 aged patients with advanced esophageal cancer. Based on the patient's free will, the patients were divided into study group (n=18) receiving stent with 125I particles and control group (n=25) receiving ordinary stent without 125I particles. No significant difference in the age, the lesion length, the degree of stenosis and the disease stage existed between the study group and the control group. The technical success rate, the remission rate of dysphagia, the occurrence of complications and the mean survival time were calculated and analyzed. The results were compared between the two groups. Results: The technical success rate was 100% in both groups. The short-term remission rate of dysphagia was also 100% in both groups. The mean survival time in the study group and in the control group was 9.8 months and 4.8 months respectively, the difference between the two groups was statistically significant (P0.05). Conclusion: This results of study indicate that for the treatment of advanced esophageal carcinomas the implantation of esophageal stent with radioactive 125I particles can surely and markedly prolong the patient's survival time and relive the symptom of dysphagia. This technique is safe, feasible and effective in clinical practice. The use of the stent with radioactive 125I particles is superior to the use of the traditional stent in treating patients with advanced esophageal cancer. (authors)

50

Comparison of methods for calculating rectal dose after 125I prostate brachytherapy implants  

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Purpose: To compare several different methods of calculating the rectal dose and examine how accurately they represent rectal dose surface area measurements and, also, their practicality for routine use. Methods and Materials: This study comprised 55 patients, randomly selected from 295 prostate brachytherapy patients implanted at the Vancouver Cancer Center between 1998 and 2000. All implants used a nonuniform loading of 0.33 mCi (NIST-99) 125I seeds and a prescribed dose of 144 Gy. Pelvic CT scans were obtained for each patient ?30 days after implantation. For the purposes of calculating the rectal dose, several structures were contoured on the CT images: (1) a 1-mm-thick anterior rectal wall, (2) the anterior half rectum, and (3) the whole rectum. Point doses were also obtained along the anterior rectal surface. The thin wall contour provided a surrogate for a dose-surface histogram (DSH) and was our reference standard rectal dose measurement. Alternate rectal dose measurements (volume, surface area, and length of rectum receiving a dose of interest [DOI] of ?144 Gy and 216 Gy, as well as point dose measures) were calculated using several methods (VariSeed software) and compared with the surrogate DSH measure (SADOI). Results: The best correlation with SA144Gy was the dose volumes (whole or anterior half rectum) (R = 0.949). The length of rectum receiving ?144 Gy also correlated well with SA144Gy (R ?0.898). Point144Gy (R ?0.898). Point dose measures, such as the average and maximal anterior dose, correlated poorly with SA144Gy (R ?0.649). The 216-Gy measurements supported these results. In addition, dose-volume measurements were the most practical (?6 min/patient), with our surrogate DSH the least practical (?20 min/patient). Conclusion: Dose-volume measurements for the whole or anterior half rectum, because they were the most practical measures and best represented the DSH measurements, should be considered a standard method of reporting the rectal dose when calculating the DSH is not practical. Average or maximal anterior rectal doses are not reliable indicators of surface area dosimetry

51

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

OpenAIRE

Abstract Background To investigate the feasibility, and safety of 125I seed permanent implantation for recurrent head and neck carcinoma under CT-guidance. Results A retrospective study on 14 patients with recurrent head and neck cancers undergone 125I seed implantation with different seed activities. The post-plan showed that the actuarial D90 of 125I 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 month...

Liu Chen; Sh, Yuan Hui; Jiang Ping; Wang Jun J; Meng Na; Jiang Yu L; Qu Ang; Yang Rui J

2010-01-01

52

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

Science.gov (United States)

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

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

2014-11-01

53

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

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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.)

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

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Treatment of Metastatic Spinal Tumors by Percutaneous Vertebroplasty versus Percutaneous Vertebroplasty Combined with Interstitial Implantation of 125I Seeds  

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Background: As the most frequent bone metastasis, spinal metastases cause severe pain and damage to vertebral bodies such as spinal osteolytic destruction and compression fractures. To avoid the trauma and complications of open surgery, a minimally invasive procedure, percutaneous vertebroplasty (PVP), has recently been developed to treat metastatic spinal tumors. Purpose: To analyze the treatment outcomes of metastatic spinal tumors by percutaneous vertebroplasty (PVP) alone or PVP combined with interstitial implantation of 125I seeds. Material and Methods: 80 patients with metastatic spinal tumors were randomized to receive PVP alone (40 cases) or PVP combined with 125I seed implantation (40 cases). Digital subtraction angiography (DSA)-guided vertebroplasty was performed under local anesthesia, and acrylic bone cement was injected into the vertebra through a bone trocar to the center of the lesion, with or without simultaneous interstitial implantation of 125I seeds. Results: At 6-month follow-up, PVP combined with 125I seed implantation resulted in zero cases with complete relief (CR), 36 with partial relief (PR), four with no changes (NC), and zero with progression of disease (PD), while PVP alone without seed implantation resulted in 0 CR, 31 PR, 7 NC, and 2 PD. While the combined-treatment group and the single-PVP group showed overall clinical benefit rates without significant difference (100% and 95.0%, respectively), their visual analogue pain scales (VAS; 2.26+-1.05 and 5.41+-0.94, respectively) and Karnofsky performance scores (KPS; 92.5+-7.1 and 87.7+-7.3, respectively) were significantly different after treatment (P = 0.028 and P = 0.009, respectively). Patients in both groups had 1-year follow-up, and the mean time to tumor progression (TTP) was 9.0 and 8.9 months, respectively (not significant). Conclusion: PVP is a minimally invasive procedure with small wounds and minor complications. It is effective in the alleviation of pain in metastatic spinal tumor patients, and its clinical outcomes can be enhanced by the combination of interstitial implantation of 125I seeds

Zuozhang Yang; Lin Xie; Yunchao Huang; Hongpu Sun; Pengjie Liu; Zhongxiong Wu (Dept. of Orthopedics, Tumor Hospital of Yunnan Province, Third Affiliated Hospital of Kunming Medical College, Kunming, Yunnan (China)). e-mail. yangzuozhang@163.com; Dakuan Yang (Second Affiliated Hospital of Kunming Medical College, Kunming Yunnan (China)); Yuqing Sun (Dept. of Orthopedic Oncology, Beijing Jishuitan Hospital, Beijing (China))

2009-12-15

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

Science.gov (United States)

The dosimetric characteristics were measured for two types of 125I low-energy photon-emitting sources by using a wide and highly sensitive thermoluminescent (TL) sheet film, which was developed for two-dimensional dose distribution measurements. The TL film is made of Teflon homogeneously mixed with small powders of thermoluminescence (BaSO4:Eu doped). Various dosimetric parameters (i.e., radial dose function, 2D and 1D anisotropy functions) of model 6711 and 6702 125I sources were obtained at various distances from the source surfaces to 15 mm. These parameters obtained with TL sheet were compared with the data recommended in the updated AAPM TG-43 report. The radial dose functions measured with TL sheet are in agreement with those established data of model 6711 125I seed and model 6702 125I seed at most of the distances within 5% and 7%, respectively. All the measured anisotropy functions showed symmetry about the longitudinal source axis. The anisotropy of dose distributions was clearly present in the immediate vicinity of the source edges. The measured 2D anisotropy function values at 1 cm are in reasonably good agreement with the recommended values. The differences at two points in the 1D anisotropy functions measured with TL sheet and the established data at 1 cm from source center were 0.7% and 1.9% for model 6711 and 6702 125I sources, respectively; the differences at 0.5 cm were 1.5% and 1.7% for model 6711 and 6702 125I sources, respectively. The relative dosimetric characteristics in the vicinity of actual interstitial brachytherapy sources containing 125I have been experimentally determined by using the TL sheet as a 2D dosimeter. PMID:15651623

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

2004-12-01

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A method for implementing the american association of physicists in medicine task group-43 dosimetry recommendations for 125I transperineal prostate seed implants on commercial treatment planning systems  

International Nuclear Information System (INIS)

Purpose: To present our experience implementing the American Association of Physicists in Medicine (AAPM) Task Group no. 43 (TG-43) recommendations for 125I dosimetry parameters utilizing two commercially available treatment planning systems. Methods and Materials: Single seed point source calculations were performed on two treatment planning systems and intercomparisons were conducted between known points of interest for (a) previously published data on each system, (b) TG-43 data on each system, and (c) hand calculations. Additional calculations and intercomparisons were performed for a typical 35 cm3 prostate volume implant with a prescribed dose of 160 Gy. Results: Intercomparisons of calculations for single seed point source approximations with previously published data and TG-43 data indicated good agreement between the two systems at a distance of 1 cm. Point source comparisons between previously published data and TG-43 recommendations show a difference in dose of 11% to the 1 cm point. Calculations for a 35 cm3 permanent interstitial prostate implant showed the 160 Gy isodose line pulled centrally toward the seeds 1-2 mm as a result of the 11% change. Conclusions: It is advisable for physicians, physicists, and dosimetrists to exercise caution when incorporating the TG-43 recommendations for 125I into treatment planning systems. The effects caused by differences in dosimetry parameters need to be understood and acco parameters need to be understood and accounted for when matching prescribed doses in order to ensure continuity of treatment and clinical results as reported in the current literature

57

Implantation of the linear 125I seed strand into portal venous trunk: an experimental study in rabbits  

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Objective: To evaluate the safety of implanting 125I seed strand into portal vein in experimental rabbits. Methods: Twenty New Zealand white rabbits were equally and randomly divided into experimental group (group T) and control group (group C), and all the rabbits were numbered. Three linear 125I seeds were sealed in a transparent catheter to form a seed strand. The seed strand was inserted into portal vein and rigidly suspended on the inner wall of portal vein in rabbits of group T, while only laparotomy with purse-string suture of portal vein was performed in rabbits of group C. Routine blood exam, liver function, CT scanning and direct portography were carried out at the 14th, 28th, 60th and 120th day after the treatment. Every two rabbits from both groups were sacrificed each time at the 14th, 28th and 60th day after the treatment, and the remaining rabbits were sacrificed at the 120th day after the treatment. Portal venous trunk, both neighboring and distant liver tissues and the duodenum were harvested for pathologic examination. Results: No irradiation related diarrhea, vomiting, body weight loss or death were observed in group T. Both MDCT and DSA showed that the blood flow in the portal vein was unobstructed. Macroscopically, no perforation, stricture or mural thrombus were found in the portal vein, and no adhesion of the implanted 125I seed strand to the inner wall of portal vein was observed. Microscopically, necrosis and e observed. Microscopically, necrosis and exfoliation of endothelial cells were seen, although no obvious pathological changes of tunicae media and adventitia were detected. Market necrosis of the liver tissue adjacent to 125I seed was well seen, while the liver tissue in the inferior area of the right hepatic lobe showed normal. No significant difference in the routine blood count and liver function existed between two groups (P > 0.05). Conclusion: Intraluminal implantation of linear 125I seed strand into portal venous trunk is safe and practicable. (authors)

58

125I implantation for carcinoma of the prostate: 5-year survival free of disease and incidence of local failure  

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Interstitial implantation with the iodine isotope, 125I has been used as definitive treatment in 115 patients with localized carcinoma of the prostate. The disease was staged surgically by bilateral pelvic lymphadenectomy in all of the patients. Followup has been for a minimum of 1 year and 64 patients have been followed for a minimum of 5 years. There has been no operative mortality in this series. Mean patient age at implantation was 63 years. Potency has been maintained in 31 of 46 patients (78 per cent) followed for a minimum of 5 years and 15 of 26 (58 per cent) followed for a minimum of 7 years. At 5 years the actuarial survival free of disease by surgical stage was 100, 81, 49 and 41 per cent for patients with stages A2, B, C and D1 disease, respectively. Local failure was defined as palpable evidence of prostatic enlargement or irregularity with biopsy confirmation of neoplasm. The actuarial probability of local failure at 5 years was 0, 13, 27 and 44 per cent for patients with surgical stages A2, B, C and D1 disease, respectively, and 5, 23 and 43 per cent for those with well, moderately and poorly differentiated tumors, respectively. Based on our experience, interstitial implantation with 125I is reserved for patients with well or moderately differentiated stage B lesions. The ultimate success of this treatment modality awaits 10 and 15 years of followup

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A new power law for determination of total 125I seed activity for ultrasound-guided prostate implants: clinical evaluations  

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Purpose: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total 125I activity required to deliver a prescription dose to a given prostate volume. Methods and Materials: Dose calculations were based on the new standards for 125I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of 125I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)2.00 where A is apparent activity in mCi, or A (U) = 1.69 d (cm)2.00 where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. Results: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D90 of these 40 patients was 172.0 Gy (SD ± 29 Gy). This matients was 172.0 Gy (SD ± 29 Gy). This means that on the average, 90% of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD ± 4.7). As a result, 94.7% of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD ± 0.21). Conclusion: This new and simple power law or a new mCi-volume look-up table for 125I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D90, CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach

60

Study of treatment using percutaneous acetabuloplasty and interstitial implantation of 125I seeds for patients with metastatic periacetabular tumors  

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Full Text Available Abstract Background The periacetabular area is one of the primary sites of metastatic tumors, which often present as osteolytic bone destruction. Bone destruction in the acetabulum caused by metastatic tumors will cause hip pain and joint dysfunction. It results in decreased quality of life for patients. The aim of our study was to explore the clinical effect of metastatic periacetabular tumors treated with percutaneous cementoplasty and interstitial implantation of 125I seeds. Methods A retrospective analysis was performed on 24 patients with metastatic periacetabular tumors who underwent combined therapy of percutaneous acetabuloplasty and interstitial implantation of 125I seeds between February 2003 and June 2011. There were 13 males and 11 females aged 19–80 years with a mean age of 57.3. The primary tumor site was the lung in eight cases, the breast in six, the prostate cancer in eight, and the liver in two. The amount of implanted 125I seeds was 12–20 seeds/person, with a mean of 16.5 seeds/person, and the matching peripheral dosage (MPD was 80~100Gy. Routine postoperative chemotherapy and other combined treatments were applied to patients after the surgical operation. Changes in the Karnofsky Score(KPS, Harris Hip Score(Harris, and Visual Analog Scale(VAS were observed during the follow-up period. Results The 24 patients’ operations were all successful. No major complications occurred. Complete pain relief was achieved in 58% (14 of 24 of patients, and pain reduction was achieved in the 42% remaining (10 patients. The mean duration of pain relief was 8.3 months. Pain recurred in one patient 3 months after surgery. Six patients had died and 18 patients were alive at the time of the 1-year follow-up. Comparing the KPS, Harris and VAS scores pre- and postoperativelyat 1, 6, and 12 months, the combined therapy method was significantly effective in metastatic periacetabular tumor patients (P Conclusions Percutaneous cementoplasty with interstitial implantation of 125I seeds is an effective treatment method for metastatic periacetabular tumor patients, providing tumor resistance, pain relief, increased bone stability, and improved quality of life for patients.

Zhang Jinlei

2012-11-01

61

125I interstitial implants in the RIF-1 murine flank tumor: an animal model for brachytherapy  

International Nuclear Information System (INIS)

The development of a model for interstitial brachytherapy that uses high-activity, removable 125I sources in the RIF-1 murine flank tumor is reported. Experimental end points are clonogenic cell and tumor regrowth delay assays. For the clonogenic cell assay, interestitial radiation is delivered at total doses of 500-10,000 rad at dose rates of 0.9-2.7 rad/min to cells in annuli of tissue in the tumor. Dose-survival curves are characterized by an initial shoulder followed by a straight (exponential) portion, with D0 similar to that of the curve obtained by external irradiation of the RIF-1 tumor in a self-contained cesium irradiator at similar dose rates. Tumor regrowth curves have been obtained for minimum tumor doses of 500-5000 rad; marked tumor regression has been observed with minimum tumor doses as low as 2000 rad, but results are not as reproducible as the results obtained with the clonogenic cell assay

62

Pharmacokinetics of 3-[{sup 125}I]iodo-{alpha}-methyl-L-tyrosine, a tumor imaging agent, after probenecid loading in mice implanted with colon cancer DLD-1 cells  

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Introduction: In order to improve tumor imaging, changes in the pharmacokinetics of 3-[{sup 123}I]iodo-{alpha}-methyl-L-tyrosine ([{sup 123}I]IMT), an artificial amino acid that exhibits high tumor accumulation, after probenecid (PBC) loading was studied in mice implanted with colon cancer DLD-1 cells using {sup 125}I-labeled IMT ([{sup 125}I]IMT). Methods: DLD-1-implanted KSN-slc nude male mice received 740 kBq of [{sup 125}I]IMT via the tail vein at 5 min after 50 mg/kg body weight PBC loading, and autoradiography was performed at 5, 15 and 30 min after injection. Male ddY mice then received 670 kBq of [{sup 125}I]IMT and 50 mg/kg 2-amino-bicyclo[2,2,1]heptane-2-carboxylic acid (BCH) or p-aminohippurate (PAH) via the tail vein, and kidney autoradiography was performed at 5 min after injection. In vitro inhibition study was then performed based on the accumulation mechanisms of [{sup 125}I]IMT in DLD-1, using 1 mM L-tyrosine, BCH, {alpha}-(methylamino)-isobutyric acid, N-benzoyl-{beta}-alanine, PBC, PAH, 2,4-dinitrophenol and sodium azide. Both Na{sup +}-dependent and Na{sup +}-independent uptake were investigated. Results: Higher tumor accumulation in PBC-loaded DLD-1-implanted mice was seen when compared to control mice. PAH and BCH, respectively, reduced renal accumulation in the tubule segment-2 (S2)-like and S1-like regions. We confirmed that [{sup 125}I]IMT transport is predominantly mediated by L-type amino acid transporter-1 in DLD-1 cells. Conclusions: [{sup 125}I]IMT uptake is mediated by organic anion and amino acid transporters in the kidney. Organic anion transporter inhibitors may yield better tumor images with good tumor/normal tissue radioactivity ratios if adequate administration plans are developed.

Nakajima, Syuichi [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Division of Health Science, Graduate School of Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 9200-942 (Japan); Shikano, Naoto [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan)], E-mail: sikano@ipu.ac.jp; Kotani, Takashi; Ogura, Masato [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Nishii, Ryuichi [Research Institute, Shiga Medical Center, 5-4-30 Moriyama, Moriyama-City, Shiga 524-8524 (Japan); Yoshimoto, Mitsuyoshi [Division of Health Science, Graduate School of Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 9200-942 (Japan); Yamaguchi, Naoto [Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Iwamura, Yukio [Center for Humanities and Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Kubota, Nobuo; Ishikawa, Nobuyoshi [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Kawai, Keiichi [Division of Health Science, Graduate School of Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 9200-942 (Japan)

2007-11-15

63

Pharmacokinetics of 3-[125I]iodo-?-methyl-L-tyrosine, a tumor imaging agent, after probenecid loading in mice implanted with colon cancer DLD-1 cells  

International Nuclear Information System (INIS)

Introduction: In order to improve tumor imaging, changes in the pharmacokinetics of 3-[123I]iodo-?-methyl-L-tyrosine ([123I]IMT), an artificial amino acid that exhibits high tumor accumulation, after probenecid (PBC) loading was studied in mice implanted with colon cancer DLD-1 cells using 125I-labeled IMT ([125I]IMT). Methods: DLD-1-implanted KSN-slc nude male mice received 740 kBq of [125I]IMT via the tail vein at 5 min after 50 mg/kg body weight PBC loading, and autoradiography was performed at 5, 15 and 30 min after injection. Male ddY mice then received 670 kBq of [125I]IMT and 50 mg/kg 2-amino-bicyclo[2,2,1]heptane-2-carboxylic acid (BCH) or p-aminohippurate (PAH) via the tail vein, and kidney autoradiography was performed at 5 min after injection. In vitro inhibition study was then performed based on the accumulation mechanisms of [125I]IMT in DLD-1, using 1 mM L-tyrosine, BCH, ?-(methylamino)-isobutyric acid, N-benzoyl-?-alanine, PBC, PAH, 2,4-dinitrophenol and sodium azide. Both Na+-dependent and Na+-independent uptake were investigated. Results: Higher tumor accumulation in PBC-loaded DLD-1-implanted mice was seen when compared to control mice. PAH and BCH, respectively, reduced renal accumulation in the tubule segment-2 (S2)-like and S1-like regions. We confirmed that [125I]IMT transport is predominantly mediated by L-type amino acid transporter-iated by L-type amino acid transporter-1 in DLD-1 cells. Conclusions: [125I]IMT uptake is mediated by organic anion and amino acid transporters in the kidney. Organic anion transporter inhibitors may yield better tumor images with good tumor/normal tissue radioactivity ratios if adequate administration plans are developed

64

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

International Nuclear Information System (INIS)

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

65

125I brachytherapy seeds implantation for inoperable low-grade leiomyosarcoma of inferior vena cava  

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A 60-year-old female presented with abdominal pain and tenderness of five-day duration. Contrast enhanced CT showed a mass of 9 x 6 x 5.5 cm in size with almost complete obliteration of the inferior vena cava and massive extension to the extravascular space. CT-guided biopsy demonstrated a low-grade leiomyosarcoma. The patient underwent 125Iodine seeds implantation in two sessions, and another balloon cavoplasty. Abdominal pain and tenderness gradually improved and the patient continues to remain as disease free state for three years after the procedures.

66

Intro-operative dosimetry of trans-rectal ultrasound guided 125I prostate implants using C-arm fluoroscopic images  

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Permanent implantation of radioactive seeds is a viable and effective therapeutic option widely used today for early-stage prostate cancer. The implant technique has improved considerably during the recent years due to the use of image guidance; however, real-time dose distributions would allow potential cold spots to be assessed and additional seeds added. In this study, we investigate the use of a conventional C-arm fluoroscopy unit for image acquisition and evaluation of dose distribution immediately after the implant. The phantom study indicates that it is possible to obtain seed positions within ±2 mm. A pilot study carried out with three patients indicated that it is possible to obtain seeds and calculate the dose distribution with C-arm fluoroscopy and about 95% of the seeds were reconstructed within ±2 mm. The results could be further improved with better digital imaging. (author)

67

Preliminary observations on the results of combined 125I seed implantation and external irradiation for carcinoma of the prostate  

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Fifty-seven patients with localized carcinoma of the prostate were treated with pelvic lymphadenectomy and a reduced 125I implant dosage, supplemented by a moderate dose of external beam radiotherapy to the whole pelvis delivered 4 to 6 weeks later. The incidence of pelvic nodal metastases was 28 per cent and the operative morbidity was 15 per cent. Late radiation sequelae developed in 18 patients, including 15 patients with radiation proctitis (29 per cent), among whom 2 (4.6 per cent) suffered rectal ulceration and required diverting colostomy. Followup has been 2 years or longer (median 33 months) in 26 patients, of whom 22 (85 per cent) are free of disease. Three patients are living with osseous metastases or local disease and there has been 1 death of prostatic carcinoma, for an absolute 2-year survival rate of 95 per cent. Of the 7 patients with poorly differentiated tumor and of the 8 patients with positive pelvic lymph nodes 5 and 6, respectively, remain free of disease after a minimum 2-year followup. Potency has been lost in 20 per cent and reduced significantly in 30 per cent of the patients followed 18 months or longer. Prostatic biopsies on 28 asymptomatic patients 12 to 30 months after completion of therapy showed no tumor in 21

68

Linear 125I seed strand implantation combined with portal vein stenting and TACE for the treatment of hepatocellular carcinoma with portal vein tumor thrombus  

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Objective: To evaluate the therapeutic efficacy of linear 125I seed strand implantation combined with portal vein stenting and transcatheter hepatic arterial chemoembolization (TACE) in treating hepatocellular carcinoma (HCC) with portal vein tumor thrombus. Methods: Seventeen HCC patients with tumor thrombus in the main branch of the portal vein received a combination therapy of linear 125I seed strand implantation with TACE. A total of 17 - 23 seeds of 125I (model 6711, 0.7 mCi) with a dosage of (73.51 ? 76.22) Gy on the first half-decay period was delivered to each patient. The postoperative complications, tumor response, stent patency rate and the successful rate of the procedure were all recorded, and the Kaplan-Meier method was used for analyzing the survival rate. Results: Stents and 125I seed strands were successfully placed in the portal veins in all patients. No serious complications occurred. The 60-, 180-and 360-day cumulative stent patency rates were 94%, 94% and 94% respectively, and the overall survival (OS) rates were 87%, 65% and 53% respectively. During a follow-up period of (2 - 13) months, twelve patients remained alive and five patients died of hepatic dysfunction (n = 4) or metastasis (n = 1). Conclusion: For the treatment of hepatocellular carcinoma with portal vein tumor thrombus, a combination of linear 125I seed strand implantation with portal vein stenting and TACE can increase the sten stenting and TACE can increase the stent patency rate, elongate the survival span, although its long-term efficacy needs to be further studied. (authors)

69

A digital model individual template and CT-guided 125I seed implants for malignant tumors of the head and neck  

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The purpose of this study was to enhance the accuracy of radioactive seed implants in the head and neck, a digital model individual template, containing information simultaneously on needle pathway and facial features, was designed to guide implantation with CT imaging. Thirty-one patients with recurrent and local advanced malignant tumors of head and neck after prior surgery and radiotherapy were involved in this study. Before 125I implants, patients received CT scans based on 0.75 mm thickness. And the brachytherapy treatment planning system (BTPS) software was used to make the implantation plan based on the CT images. Mimics software and Geomagic software were used to read the data containing CT images and implantation plan, and to design the individual template. Then the individual template containing the information of needle pathway and face features simultaneously was made through rapid prototyping (RP) technique. All patients received 125I seeds interstitial implantation under the guide of the individual template and CT. The individual templates were positioned easily and accurately, and were stable. After implants, treatment quality evaluation was made by CT and TPS. The seeds and dosages distribution (D90, V100, V150) were well meet the treatment requirement. Clinical practice confirms that this approach can facilitate easier and more accurate implantation. (author)or)

70

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

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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 103Pd than for 125I, 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 nners should avoid planning seeds at 5 mm or closer from the urethra. Special caution is indicated in prostates having about 20 cm3 or smaller volumes, and when 103Pd is used. Postimplant dosimetry is susceptible to the same errors

71

The evaluation of short term effect of CT guided radioactive seed 125I implantation in treating pulmonary metastases from gastrointestinal tumor  

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Objective: To investigate the short term effect of CT guided radioactive seed 125I implantation in treating pulmonary metastases from gastrointestinal tumor. Methods: 20 patients (male 13, female 7, the age range of 25 to 73, mean age 49±24) with pulmonary metastases from gastrointestinal tumor accepting CT guided radioactive seed 125I implantation were enrolled in this study. Among these patients, no more than 5 pulmonary metastases lesions occurred in any one case, diameters of all lesions were from 0.5 to 3.0 cm with. average 2.8 lesions per case, and the mean diameter of pulmonary metastases was 2.1 cm. 13 cases presented pulmonary metastases only unilaterally, and 7 others were found bilaterally. All primary tumors were confirmed by pathology, and pulmonary metastases were identified by CT or MRI and confirmed through pathology. Under CT guidance, 125I seeds were implanted into pulmonary metastases according to CT based computerized treatment planning in radio-oncology of the treatment planning system (TPS). All cases were observed two months after the treatment. Results: Among 56 pulmonary metastases in 20 patients, 32 obtained CR, 19 PR, 5 NC. The responsive rate was 91.1%. During follow up, no mortality occurred, but with complications of pneumothorax in 2 cases, bloody sputum in 2 cases, hemothorax in 1 case. Conclusions: CT guided radioactive seed 125I implantation procedure possesses satisfied clinical effects ine possesses satisfied clinical effects in treating pulmonary metastases from gastrointestinal tumor with minimal damage and few complications, especially in these patients with no more than 5 pulmonary metastases, and less than 3.0 cm in diameter. (authors)

72

CT-guided 125I seeds implantation combined with NP chemotherapy for the treatment of intractable central airway stenosis caused by NSCLC  

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Objective: To explore the clinical value of radioactive 125I seeds implantation combined with NP in treating intractable central airway stenosis caused by non-small cell cancer (NSCLC). Methods: A prospective cohort study of 80 patients, who were admitted to Beichen hospital (Tianjin, China) during the period from January 2004 to March 2010, were enrolled in this study. The patients were randomly divided into study group (n=42) and control group (n=38). Percutaneous CT-guided intratumoral implantation of 125I seeds was carried out in the patients of the study group. Treatment plan system (TPS) was used to design the distribution and the number of 125I seeds with PD=80-100 CY, and the source intensity was 0.8 mCi. Three days after operation the NP chemotherapy started and it was performed for 2 cycles. Only two cycles of NP chemotherapy was used for the patients in the control group. After the treatment, the cross area of the airway at its narrowest level was measured and the dyspnea index was evaluated. Results: All the patients were followed up for two months. The preoperative and postoperative stenosis rate of the airway in study group was 47.82%±17.55% and 15.76%±4.65%, respectively. The trachea was unobstructed and the dyspnea was markedly improved. The postoperative cross area of the airway at its narrowest level was significantly bigger than the preoperative one (P0.05). Conclusion: Radioactive 125I seeds implantation combined with NP chemotherapy is a safe and effective treatment for NSCLC. (authors)

73

Inverse automated treatment planning with and without individual optimization in interstitial permanent prostate brachytherapy with high- and low-activity 125I  

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Purpose: To determine whether dose distribution achieved with treatment plans using high- and low-activity 125I implants differs. Patients and Methods: Based on intraoperative transrectal ultrasound scans of 71 patients, inverse automated treatment plans (IATP) were performed with 15.5-kBq (0.42-mCi) and 25.2-kBq (0.68-mCi) 125I implants using a commercial 3-D planning system (Variseed trademark). A prescription dose of 145 Gy in 98% of the prostate volume (V100), a maximum dose to the urethra of 250 Gy (D1), and a maximum dose to 10% of the anterior rectal wall of 145 Gy (D10) were required. The plans were manually corrected, if necessary. Results: In the IATP, a better dose coverage of the prostate was found for high-activity seeds (V100 of 98% vs 84%). The prostate dose values increased with the prostate volume. After manual optimization, the differences were only marginal with a prostate V100 of 99% for both activities, a urethra D1 of 247 Gy and 239 Gy, and a rectum D10 of 135 Gy and 124 Gy for high- and low-activity seeds. Low-activity seeds required more sources (66 vs 47) and needles (24 vs 17; all numbers are median values). Conclusions: Concerning the prostate dose coverage, high-activity seeds are superior in the IATP. After manual adjustment, the dose values for the prostate and the organs at risk are similar. Considering a supposedly decreased toxicity and a shorter implantation time for a lower number of seeds, we recommend high-actwer number of seeds, we recommend high-activity seeds for experienced teams. (orig.)

74

Permanent Planar Iodine-125 Implants: The Dosimetric Effect of Geometric Parameters for Idealized Source Configurations  

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Purpose: To provide dosimetric information about permanent planar 125I implants in a manner that is useful to the brachytherapist in the operative setting. Methods and Materials: Reference planar permanent implants were simulated for a variety of areas with sources placed uniformly on a 1-cm grid. Implants having variable source spacing and curvature were simulated and compared with the reference implants. Dosimetric measures were calculated at 0.5 and 1.0 cm from the implant plane. Results: A method for calculating dosimetric statistics for permanent implants ranging from 5 x 5 cm to 13 x 13 cm is presented. A formula to predict the reference source strength needed to achieve a desired dosimetric quantity is also presented. The effect of adjusting strand spacing to compensate for source activity is presented and is shown to be an effective means to adjust implants to use source strengths other than the reference strength. The effect of implant curvature compared with flat implants on dosimetric statistics is presented as a function of radius of curvature. Conclusions: The results presented in this work may be used to provide information about dose delivered from planar permanent implants

75

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

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

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Evaluation of CT-guided 125I seed implantation combined with transcatheter arterial chemoembolization in treating portal vein tumor thrombus associated with hepatocellular carcinoma  

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Objective: To discuss the therapeutic effect of CT-guided 125I seed implantation combined with transcatheter arterial chemo embolization (TACE) for the treatment of portal vein tumor thrombus (PVTT) associated with hepatocellular carcinoma (HCC). Methods: A total of 58 patients with confirmed HCC accompanied by PVTT were enrolled in this study. Of the 58 patients, CT-guided 125I seed implantation together with TACE was performed in 26 (group A), while only TACE was employed in 32 (group B). The clinical data were retrospectively analyzed and the therapeutic results were compared between two groups. Results: For group A, the one-year and two-year survival rate was 42.3% and 23.0% respectively, with a mean survival time of 15.5 months. Of the 26 patients in group A, the complete remission (CR) was obtained in 3, partial remission (PR) in 9, with a total effective rate (CR + PR) of 46.2% (12 /26). While in group B, the one-year and two-year survival rate was 21.9% and 6.3% respectively, with a mean survival time of 7.5 months. And CR was obtained in 2 cases, PR in 6 cases,with a total effective rate (CR + PR) of 25% (8/32). Both the survival rate and the total effectiveness of group A were significant higher than that of group B (P 125I seed implantation combined with transcatheter arterial chemo embolization can markedly improveal chemo embolization can markedly improve the therapeutic effect for portal vein tumor thrombus associated with hepatocellular carcinoma. (authors)

77

Radiation protection after interstitial permanent prostate brachytherapy implants  

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Full text of publication follows: In this study we measure patients radiation exposure dose after interstitial 125I permanent prostate Brachytherapy implants, and correlate it with dose limits for public, total activity implanted, patient preoperative weight(1), distance between prostate walls and anterior skin surface. Methods and Material: We analyse 20 patients who were implanted with 125I seeds. The instrument used to measure radiation is a calibrated Berthold Umo LB 123 aco-plated to a LB 1236-H10 detector. Three measurements were taken: at the perineal and anterior pelvic zones on contact with the skin and at 1 m from the patient. The maximum value was taken for all measurements. The dose at a distance of one meter is obtained at anterior pelvic zone, perpendicular to the skin, according to the recommendations of A.A.P.M.(1). The distance between prostate walls was determined using post -operative CT images. Results: The doses at the perineal zone have determined an average of 186 ?Sv/h (range: 110 340 ?Sv/h) and at surface pelvic zone of 41 ?Sv/h (range: 15 103 ?Sv/h). The dose at a distance of 1 meter has an average value of 0.4 ?Sv/h (range: 0.2 1.0 ?Sv/h). The average total activity implanted was 25 mCi (range: 17 38 mCi). The distance between prostate walls and skin pelvic surface of the patients has an average value of 8.9 cm (range: 6.6 -11.5 cm). At a distance of 1 meter from the pelvic zone the dose measured is very low and b the dose measured is very low and below dose limits imposed by the European Directive EURATOM 2 and the Portuguese law. For general public to reach annual dose limit (EURATOM - 1 mSv/year) when contacting the pelvic zone, we extrapolate that 4 days (range: 1.6 11.1 days) would be needed, assuming a daily contact period of 6 hours. Conclusion: We established a correlation between the distance of prostate walls to the skin perineal surface and the total dose, but we find no correlation between measured doses, total activity implanted and patient weight. Our results show that recommendations to the patients must be very careful, stating that all contact must be as short as possible, at least in the first 125I half life period. References: (1) Yan Yu et all., 'Permanent prostate seed implant brachytherapy: report of the A.A.P.M. - TG 64', Med. Phys, 26 (10), pp. 2054-2076, 1999. (2) S. Smathers, et all., 'Radiation safety parameters following prostate brachytherapy', Int. J. Rad. Onc. Biol. Phys. Vol 45, no 2, pp. 397 -399, 1999. (3) Council Directive 97/43/EURATOM of 30 of June. (authors)

78

Radiation protection after interstitial permanent prostate brachytherapy implants  

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Full text of publication follows: In this study we measure patients radiation exposure dose after interstitial {sup 125}I permanent prostate Brachytherapy implants, and correlate it with dose limits for public, total activity implanted, patient preoperative weight(1), distance between prostate walls and anterior skin surface. Methods and Material: We analyse 20 patients who were implanted with {sup 125}I seeds. The instrument used to measure radiation is a calibrated Berthold Umo LB 123 aco-plated to a LB 1236-H10 detector. Three measurements were taken: at the perineal and anterior pelvic zones on contact with the skin and at 1 m from the patient. The maximum value was taken for all measurements. The dose at a distance of one meter is obtained at anterior pelvic zone, perpendicular to the skin, according to the recommendations of A.A.P.M.(1). The distance between prostate walls was determined using post -operative CT images. Results: The doses at the perineal zone have determined an average of 186 {mu}Sv/h (range: 110 340 {mu}Sv/h) and at surface pelvic zone of 41 {mu}Sv/h (range: 15 103 {mu}Sv/h). The dose at a distance of 1 meter has an average value of 0.4 {mu}Sv/h (range: 0.2 1.0 {mu}Sv/h). The average total activity implanted was 25 mCi (range: 17 38 mCi). The distance between prostate walls and skin pelvic surface of the patients has an average value of 8.9 cm (range: 6.6 -11.5 cm). At a distance of 1 meter from the pelvic zone the dose measured is very low and below dose limits imposed by the European Directive EURATOM 2 and the Portuguese law. For general public to reach annual dose limit (EURATOM - 1 mSv/year) when contacting the pelvic zone, we extrapolate that 4 days (range: 1.6 11.1 days) would be needed, assuming a daily contact period of 6 hours. Conclusion: We established a correlation between the distance of prostate walls to the skin perineal surface and the total dose, but we find no correlation between measured doses, total activity implanted and patient weight. Our results show that recommendations to the patients must be very careful, stating that all contact must be as short as possible, at least in the first {sup 125}I half life period. References: (1) Yan Yu et all., 'Permanent prostate seed implant brachytherapy: report of the A.A.P.M. - TG 64', Med. Phys, 26 (10), pp. 2054-2076, 1999. (2) S. Smathers, et all., 'Radiation safety parameters following prostate brachytherapy', Int. J. Rad. Onc. Biol. Phys. Vol 45, no 2, pp. 397 -399, 1999. (3) Council Directive 97/43/EURATOM of 30 of June. (authors)

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

2006-07-01

79

Monte Carlo calculated doses to treatment volumes and organs at risk for permanent implant lung brachytherapy  

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Iodine-125 (125I) and Caesium-131 (131Cs) brachytherapy have been used with sublobar resection to treat stage I non-small cell lung cancer and other radionuclides, 169Yb and 103Pd, are considered for these treatments. This work investigates the dosimetry of permanent implant lung brachytherapy for a range of source energies and various implant sites in the lung. Monte Carlo calculated doses are calculated in a patient CT-derived computational phantom using the EGsnrc user-code BrachyDose. Calculations are performed for 103Pd, 125I, 131Cs seeds and 50 and 100 keV point sources for 17 implant positions. Doses to treatment volumes, ipsilateral lung, aorta, and heart are determined and compared to those determined using the TG-43 approach. Considerable variation with source energy and differences between model-based and TG-43 doses are found for both treatment volumes and organs. Doses to the heart and aorta generally increase with increasing source energy. TG-43 underestimates the dose to the heart and aorta for all implants except those nearest to these organs where the dose is overestimated. Results suggest that model-based dose calculations are crucial for selecting prescription doses, comparing clinical endpoints, and studying radiobiological effects for permanent implant lung brachytherapy. (paper)

80

Permanent transvenous pacemaker implantation in forty dogs  

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Permanent transvenous cardiac pacemakers were implanted in 40 dogs. Electrocardiographic diagnoses included persistent atrial standstill (3 dogs), sick sinus syndrome (8 dogs), and high-grade second-degree or third-degree atrioventricular (AV) block (29 dogs). Thirteen dogs were alive and well 4 to 42 months after pacemaker implantation (mean, 16.9 months). The mean and median survival times of the 26 dogs that died or were euthanatized during the study were 17.9 months and 13 months, respectively. Most of these dogs succumbed to problems unrelated to the arrhythmia and pacemaker implant. One dog was lost to follow-up. Complications associated with permanent transvenous pacemaker implantation included lead dislodgement, infection, hematoma formation, skeletal muscle stimulation, ventricular arrhythmia, migration of the pulse generator, and skin erosion. Lead dislodgement was the most common complication, occurring in 7 of 9 dogs paced using untined electrode leads and in 6 of 30 dogs paced using tined leads. Lead dislodgement did not occur in the only dog paced using an actively fixed endocardial lead. It was concluded that permanent transvenous cardiac pacing is a feasible, less traumatic alternative to epimyocardial pacing in dogs, but that successful use of this technique requires careful implantation technique and anticipation of the potential complications

81

Permanent iodine-125 implants in malignant gliomas  

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Introduction: Permanent I-125 implants in the primary treatment of malignant gliomas have not been widely utilized in North America. This report summarizes the Detroit experience concerning survival, prognostic factors and toxicity following low dose rate, permanent I-125 implants in the primary treatment of malignant gliomas. Material and Methods: between 1988-1995, 91 patients; 51 non-glioblastoma malignant gliomas (NGM), 40 glioblastoma multiforme (GBM), were implanted as part of the initial treatment. Eighty-one patients received additional partial brain external beam radiation (50-60 Gy); following implant in 61 patients, preceding implant in 20 patients. Ten patients (9 NGM, 1 GBM) underwent implant without addition external beam radiation. Stereotactic treatment planning was used to encompass the contrast-enhancing rim of the tumor visualized by computerized tomography with an initial dose rate of 0.5 Gy/hr with iodine-125, delivering 100 Gy at 1 year and 103.68 Gy at infinity. Results: with a median follow-up of 30 months (range of 3 months to 7.25 years), the 1, 2 and 3 year survival for the NGMs was 79%, 68%, 63%; the 1 and 2 year survival for the GBMs was 35% and 21%. Second surgery in (42(91)) (49%) revealed primarily tumor recurrence in 26 (63%), radiation necrosis in 14 (33%), brain abscess 1 (2%) and skull necrosis in 1 (2%). Adverse prognostic factors identified were GBM pathology, deep tumor location in the corpus callosum or thalamus, and age greaterrpus callosum or thalamus, and age greater than 60. Conclusions: permanent I-125 implants are associated with a relatively high-quality, long-term survival

82

Combination chemotherapy of gemcitabine and cisplatin by double way plus implantation of radioactive seed 125I in treating stage ? non-small cell lung cancer  

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Objective: To assess the therapeutic effect of combination chemotherapy of gemcitabine and cisplatin by double way plus implantation of radioactive seed 125I implantation in treating stage ? non-small cell lung cancer. Methods: Sixty cases with stage ? non-small cell lung cancer were randomly divided into two groups with random number table. In group A (in interventional treatment group, n=30), the gemcitabine 1000 mg/m2 and one third of the cisplatin 100 mg/m2 was given using Seldinger technique for transcatheter bronchial arterial infusion chemotherapy on day 1. Two-thirds of the cisplatin 100 mg/m2 was infused in veins on day 2 and 3. The gemcitabine 1000 mg/m2 was infused in veins on day 8, 21 days for a period. In group B (interventional - 125I groups), the method of combination chemotherapy of gemcitabine and cisplatin was the same as in Group A. After ten days of arterial perfusion, 125I seeds were implanted, 21 days for a period. All patients received at least 2 cycles. The imaging evaluation of patients after treatment standards included complete remission (CR), partial remission (PR), stable (SD), progressive disease (PD), effective rate (CR + PR)/30 and clinical benefit rate (CR + PR + SD)/30. Non-parametric rank sum test was used to compare short-term effect of the two groups treatment of two cycles. ?2 test was used to compare year survival, Kaplan-Meier method was used to calculate median survival, log-rank test method was used to difference between the groups. Results: In group A, there were 17 PR, 9SD and 4 PD. The overall response rate was 56.7% (17/30) and clinical beneficial rate was 86.7% (26/ 30). In Group B, there were 2 CR, 21 PR, 7 SD. The overall response rate was 76.7% (23/30) and clinical beneficial rate was 100% (30/30). There was significant difference between the two groups (P= 0.036). In group A, the 1 year survival rate was 46.7% (14/30) and the 2 year survival rate was 36.7% (11/30), median survival time (MST) was 10 months. In group B, the 1 year survival rate was 76.7% (23/30) and the 2 year survival rate was 63.3% (19/30), median survival time (MST) was 27 months. There was a significant difference between two group in 1 year survival rate (P=0.017), 2 year survival rate (P=0.039) and median survival time (P=0.006). Conclusion: The treatment effects of ? stage non-small cell lung cancer by gemcitabine and cisplatin combination chemotherapy with double way plus radioactive seed 125I implantation was better than gemcitabine and cisplatin combination chemotherapy with double way. (authors)

83

Use of Cesium-131 radioactive seeds in prostate permanent implants  

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Permanent prostate seed implantation is a minimally invasive approach to implant low activity radioactive sources to the prostate gland with the guidance of transperineal ultrasound technique. Recently, a new Cesium-131 radioactive seed has been introduced in the clinical practice for permanent seed implants of early prostate cancer. Since being introduced in 2004, about 3000 prostate implants using 131Cs seeds have been performed

84

Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants  

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

85

Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants  

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

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

2006-07-01

86

Quality of life after permanent prostate implant  

International Nuclear Information System (INIS)

Purpose: To report on the quality of life in patients who have received a permanent transperineal ultrasound guide prostate implant. There is increasing recognition that prostate cancer therapy impacts significantly on the patients ability to pursue relational, occupational and social interests. With the substantially expanded patient role in directing treatment for prostate cancer, the importance of examining quality of life outcomes in addition to survival has been underscored. Materials and Methods: 51 sequential patients with clinically localized prostate cancer who underwent permanent prostate implantation from September 1995 to October 1996 were evaluated. All patients were clinically staged as T1c or T2a and received implant with Iodine 125 or Palladium 103 as definitive treatment. Data was collected using the EORTC genitourinary group questionnaire and supplemental questions during an interview. Results: Urinary symptoms such as nocturia, frequency and dysuria were the most pronounced in the first two months after implant and then decreased in the majority of patients. The EORTC questionnaire was administered at 6 months and examined urinary quality, sexual quality and perception of symptoms. With regard to urinary quality, 17% had mild dysuria at 6 months and 40% noted that they urinated more frequently than pre implant. No patient had hematuria and 0 % were incontinent. 3% stated that they had occasional loss of minimal urine with severe urgency. Only 2% reqmal urine with severe urgency. Only 2% required intermittent self catheterization after implant secondary to obstructive symptoms. Over 90% were on an alpha blocker post implant for a minimum of 6 weeks. 0% reported psychological distress and 3% noted a disruption in social or family life. 15% experienced some fatigue and 10% noted a decreased functional status but only 1% a decreased role function. Additional questions addressed lifestyle and work issues. 100% would have an implant again as definitive treatment and 98% would recommend the procedure to a friend. Of the patients who had full time employment (38), 96% returned to work after the implant and the majority returned within 5 days. Sexual quality was high in this short follow up after seed implant. 89% of potent patients retained sexual function after implant. 3% noted some discomfort with ejaculation. 12% noticed some decrease in sexual desire. Interestingly, 14% experienced an increase in sexual desire. 79% reported an excellent overall quality of life. Conclusions: While survival is clearly a central goal of treatment for prostate cancer, the nature of this malignancy compels clinical attention to the qualitative content of the patients life after treatment. Permanent prostate implant has a high degree of patient tolerance and patient acceptance. Sexual quality and function are maintained in the majority of patients and they have minimal interruption in their social and economic function. The low morbidity and high quality of life associated with implantation make it a viable treatment option

87

Methodology of quality control for brachytherapy 125I seeds  

International Nuclear Information System (INIS)

This paper presents the methodology of quality control of 125I seeds used for brachytherapy. The 125I 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 125I 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 125I 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)

88

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

89

In Vivo Dosimetry With a Linear MOSFET Array to Evaluate the Urethra Dose During Permanent Implant Brachytherapy Using Iodine-125  

International Nuclear Information System (INIS)

Purpose: To develop a technique to monitor the dose rate in the urethra during permanent implant brachytherapy using a linear MOSFET array, with sufficient accuracy and without significantly extending the implantation time. Methods and Materials: Phantom measurements were performed to determine the optimal conditions for clinical measurements. In vivo measurements were performed in 5 patients during the 125I brachytherapy implant procedure. To evaluate if the urethra dose obtained in the operating room with the ultrasound transducer in the rectum and the patient in treatment position is a reference for the total accumulated dose; additional measurements were performed after the implantation procedure, in the recovery room. Results: In vivo measurements during and after the implantation procedure agree very well, illustrating that the ultrasound transducer in the rectum and patient positioning do not influence the measured dose in the urethra. In vivo dose values obtained during the implantation are therefore representative for the total accumulated dose in the urethra. In 5 patients, the dose rates during and after the implantation were below the maximum dose rate of the urethra, using the planned seed distribution. Conclusion: In vivo dosimetry during the implantation, using a MOSFET array, is a feasible technique to evaluate the dose in the urethra during the implantation of 125I seeds for prostate brachytherapy.hytherapy.

90

Post implant dosimetric evaluation of I-125 permanent prostate implants  

International Nuclear Information System (INIS)

Purpose/Objective: To evaluate the dosimetric quality of ultrasound (US) guided I-125 permanent seed implants for prostate cancer planned using preimplant US images and reconstructed using postimplant CT images. Materials and Methods: Preimplant US images were used to calculate I-125 seed locations on a 0.5 cm grid with parallel needle positions, to obtain the prescription dose to a 5 mm margin around the prostate. Patients were implanted with I-125 seeds in the operating room using a Mick applicator and free hand guidance of the needles/seeds using a 0.5 cm grid template on the ultrasound images. The clearly visualized needle tip in the saggital images was used to determine the seed drop off position. Patients were simulated on a conventional and a CT simulator within 24 hours of the implant. Prostate contours were outlined on the CT images by the radiation oncologist. Seed positions reconstructed from CT images and verified with localization films were used to generate post implant dose distributions. Dose volume histograms of the implant and the prostate were used to obtain the following parameters which were subsequently used to evaluate the quality of the implants: (i) prostate volume covered by prescription dose (PVPD), (ii) implant volume of prescription dose (IVPD), (iii) minimum peripheral dose (MPD), and (iv) heterogeneity index (HI). Results: The table below lists the various dosimetric parameters used for evaluating the implants, for three representative cg the implants, for three representative cases. Conclusions: In spite of the observed deviations in the seed locations from the preplan, the implant volumes of the prescription dose were comparable in the pre and post plans. The postimplant CT volumes were consistently larger than the preimplant US volumes. Even though the implant volumes were consistently larger than the postimplant CT prostate volumes, the fraction of the prostate receiving the prescription dose ranged from 75% to 95%, which is consistent with other studies published in the literature. This could be due to either a difference in the US and CT prostate shapes and volumes, or a geometrical mispositioning of the seeds. The areas of the prostate receiving less than the prescribed dose were found to be randomly distributed in all cases. Our implant procedure, based on US based preplanning and CT based postplanning is seen to be comparable to those practised at other centers. Deviations from planned dose distributions most likely indicate the limitations of this concept, which could be overcome by on-line postimplant dose verification and correction in the OR or re-implantation at a later time

91

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

Energy Technology Data Exchange (ETDEWEB)

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 ({sup 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{sub p}90, V{sub p}100, and V{sub 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{sub p}90: 90.6% (standard deviation [SD]: 9.0%), V{sub p}100: 86.1% (SD: 14.7%), and V{sub p}400: 79.4% (SD: 14.4%). For three out of the eight patients the D{sub 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.)

Siebert, F.A.; Kohr, P.; Kovacs, G. [Clinic of Radiotherapy, Interdisciplinary Brachytherapy Center, Univ. Hospital of Schleswig-Holstein, Campus Kiel (Germany)

2006-02-01

92

Radiation protection procedures and dose to the staff in brachytherapy with permanent implant of the sources  

Energy Technology Data Exchange (ETDEWEB)

The treatment of intra capsular prostate cancers with the permanent implantation of low energy sealed radioactive sources (''103 Pd-''125I) offers the same probability of curing the tumours as surgery and external-beam radiotherapy with a minimum incidence of unwanted side-effects. The first attempts of using sealed sources for treating prostate cancers go back to 1917, when Barringer reported the results obtained with the implant of ''236Ra needles. Beginning from that period the interest for prostate brachytherapy has shown a fluctuating trend, due especially to the technological possibilities and to the status of the alternative treatment modalities (surgery, external radiotherapy). The main reason of the substantial failure of brachytherapy as compared to the two other treatment modalities had two main causes: the energy, too high ( E{approx_equal} 840 keV), of {gamma}-radiation emitted by ''226 Ra in equilibrium with its decay products and the lack of imaging techniques able to visualize with sufficient accuracy both the prostate and the arrangement, inside it, of the radioactive sources. The employ of low energy {gamma}-emitting radionuclides began in 1974, when Whitmore et al. working at the Sloan Kettering Memorial Cancer Hospital of New York suggested the use of ''125 I sealed sources for the realisation of interstitial permanent implants. Also this attempt, though reducing the side effects typical of the surgical intervention (incontinence, impotence), did non give the expected results in terms of local control of the disease and, as a consequence, of the survival's length. This partial failure was attributed to the fact that, in most cases the dose distribution inside the target volume was not homogeneous, due to the inadequacy of the available imaging techniques used for checking the real position of the sources, during their manual insertion in the tissues. In the last ten years,however, great progresses have been made in the US{sub i}maging techniques, in the manufacture of suitable sealed sources of ''103 Pd and ''125 I, in the development of computer programs able both to acquire US-images and to calculate and display in real time the dose distribution. In selected cases, the permanent implant of such sources has demonstrated of being alternative to the surgical intervention and even to external conformal radiotherapy. (Author)

Tosi, G.; Cattani, F.

2002-07-01

93

Permanent Breast Seed Implant Dosimetry Quality Assurance  

Energy Technology Data Exchange (ETDEWEB)

Purpose: A permanent breast seed implant is a novel method of accelerated partial breast irradiation for women with early-stage breast cancer. This article presents pre- and post-implant dosimetric data, relates these data to clinical outcomes, and makes recommendations for those interested in starting a program. Methods and Materials: A total of 95 consecutive patients were accrued into one of three clinical trials after breast-conserving surgery: a Phase I/II trial (67 patients with infiltrating ductal carcinoma); a Phase II registry trial (25 patients with infiltrating ductal carcinoma); or a multi-center Phase II trial for patients with ductal carcinoma in situ (3 patients). Contouring of the planning target volume (PTV) was done on a Pinnacle workstation and dosimetry calculations, including dose-volume histograms, were done using a Variseed planning computer. Results: The mean pre-implant PTV coverage for the V{sub 90}, V{sub 100}, V{sub 150}, and V{sub 200} were as follows: 98.8% {+-} 1.2% (range, 94.5-100%); 97.3% {+-} 2.1% (range, 90.3-99.9%), 68.8% {+-} 14.3% (range, 32.7-91.5%); and 27.8% {+-} 8.6% (range, 15.1-62.3%). The effect of seed motion was characterized by post-implant dosimetry performed immediately after the implantation (same day) and at 2 months after the implantation. The mean V{sub 100} changed from 85.6% to 88.4% (p = 0.004) and the mean V{sub 200} changed from 36.2% to 48.3% (p < 0.001). Skin toxicity was associated with maximum skin dose (p = 0.014). Conclusions: Preplanning dosimetry should aim for a V{sub 90} of approximately 100%, a V{sub 100} between 95% and 100%, and a V{sub 200} between 20% and 30%, as these numbers are associated with no local recurrences to date and good patient tolerance. In general, the target volume coverage improved over the duration of the seed therapy. The maximum skin dose, defined as the average dose over the hottest 1 Multiplication-Sign 1-cm{sup 2} surface area, should be limited to 90% of the prescription dose to minimize delayed skin toxicity.

Keller, Brian M., E-mail: Brian.Keller@sunnybrook.ca [Department of Medical Physics, Sunnybrook Health Sciences Center, Toronto, ON (Canada); Department of Radiation Oncology, University of Toronto, Sunnybrook Health Sciences Center, Toronto, ON (Canada); Ravi, Ananth [Department of Medical Physics, Sunnybrook Health Sciences Center, Toronto, ON (Canada); Sankreacha, Raxa [Carlo Fidani Regional Cancer Center, Mississauga, ON (Canada); Pignol, Jean-Philippe [Department of Radiation Oncology, University of Toronto, Sunnybrook Health Sciences Center, Toronto, ON (Canada)

2012-05-01

94

Permanent Breast Seed Implant Dosimetry Quality Assurance  

International Nuclear Information System (INIS)

Purpose: A permanent breast seed implant is a novel method of accelerated partial breast irradiation for women with early-stage breast cancer. This article presents pre- and post-implant dosimetric data, relates these data to clinical outcomes, and makes recommendations for those interested in starting a program. Methods and Materials: A total of 95 consecutive patients were accrued into one of three clinical trials after breast-conserving surgery: a Phase I/II trial (67 patients with infiltrating ductal carcinoma); a Phase II registry trial (25 patients with infiltrating ductal carcinoma); or a multi-center Phase II trial for patients with ductal carcinoma in situ (3 patients). Contouring of the planning target volume (PTV) was done on a Pinnacle workstation and dosimetry calculations, including dose–volume histograms, were done using a Variseed planning computer. Results: The mean pre-implant PTV coverage for the V90, V100, V150, and V200 were as follows: 98.8% ± 1.2% (range, 94.5–100%); 97.3% ± 2.1% (range, 90.3–99.9%), 68.8% ± 14.3% (range, 32.7–91.5%); and 27.8% ± 8.6% (range, 15.1–62.3%). The effect of seed motion was characterized by post-implant dosimetry performed immediately after the implantation (same day) and at 2 months after the implantation. The mean V100 changed from 85.6% to 88.4% (p = 0.004) and the mean V200 changed from 36.2% to 48.3% (p 90 of approximately 100%, a V100 between 95% and 100%, and a V200 between 20% and 30%, as these numbers are associated with no local recurrences to date and good patient tolerance. In general, the target volume coverage improved over the duration of the seed therapy. The maximum skin dose, defined as the average dose over the hottest 1 × 1-cm2 surface area, should be limited to 90% of the prescription dose to minimize delayed skin toxicity.

95

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

Directory of Open Access Journals (Sweden)

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

Saika,Takeshi

2008-02-01

96

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

International Nuclear Information System (INIS)

From January 2004 to March 2007, 308 patients with clinically localized prostate cancer were treated using iodine-125 (125I) seed implantation (permanent brachytherapy) at Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences. We evaluated the treatment's 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. 125I seed implantation brachytherapy is safe and effective for localized prostate cancer within short-term follow up. (author)

97

Tumor interventional therapy using 125I seed  

International Nuclear Information System (INIS)

Objective: To explore the feasibility, safety, and effect of interventional technology for inserting 125I seeds into tumor focus and to study the advantage or shortcome of different image equipment used in seed implantation. Methods: Fifteen cases of advanced stage tumor with metastasis and another 15 cases of advanced unresectable esophageal cancer were enrolled. Method of seed implantation was carried out by inserting 125I seeds into tumor foci through percutaneous puncture under ultrasound or CT guidance, and placed the esophageal stent binding with 125I seed to the diseased esophageal segment under DSA. Results: All 125I seeds were successfully released to the target places under ultrasound, CT and DSA guidance, except one seed was found to be lost from one esophageal 125I seed irradiated stent due to misoperation. A follow-up showed obvious improvement of clinical symptom, no significant changes of hemogram, immunity markers, and no complications including esophageal perforation, hemorrhage, and skin necrosis. No radiation seeds shedded during the releasing processes by ECT. One month follow-up by CT showed the target places were thinned in 13 cases, thickened in 2 cases. 3 cases had been followed-up for 13 months, CT revealed the obvious thinning of the foci. Three-month follow up with gastroendoscopy and biopsy demonstrated that the foci within the 125I seede binding stent placement segment resoleede binding stent placement segment resolved markedly, with no tumor cells found in biopsy for 3 of 5 cases. 15 cases by percutaneous puncture implantation had been followed-up for two months, showed the foci becoming obviously small under diagnostic imaging. Conclusions: It is feasible and safe to insert 125I seeds into tumor foci by interventional technology and the confirmed effect is favorable. (authors)

98

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

Science.gov (United States)

...Interim Enforcement Policy for Permanent Implant Brachytherapy Medical Event Reporting...occurring under an NRC licensee's permanent implant brachytherapy program. This interim policy...that are authorized to perform permanent implant brachytherapy. DATES: This policy...

2013-07-09

99

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

International Nuclear Information System (INIS)

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 125I, 103Pd, and 137Cs 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, ?, 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, REpreplan, in a 5x5x5 cm3 volume for 125I (Oncura 6711), olume for 125I (Oncura 6711), 103Pd (Theragenics 200), and 131Cs (IsoRay CS-1) seeds arranged in the Radiological Physics Center test case 2 configuration for a range of edema relative magnitudes (?=[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, REpreplan for our edema model indicated underdosage in the calculation volume with a clear dependence on seed and calculation point positions, and increased with increasing values of ? and T. Values of REpreplan were generally larger near the ends of the virtual prostate in the RPC phantom compared with more central locations. For edema characteristics similar to the population average values previously measured at our center, i.e., ?=0.2 and T=28 d, mean values of REpreplan in an axial plane located 1.5 cm from the center of the seed distribution were 8.3% for 131Cs seeds, 7.5% for 103Pd seeds, and 2.2% for 125I seeds. Maximum values of REpreplan in the same plane were about 1.5 times greater. Note that detailed results strictly apply only for loose seed implants where the seeds are fixed in tissue and move in synchrony with that tissue. Conclusions: A dose calculation method for permanent prostate implants incorporating spatially anisotropic linearly time-resolving edema was developed for which cumulative dose can be written in closed form. The method yields values for REpreplan that differ from those for spatially isotropic edema. The method is suitable for calculating pre- and postimplant dosimetry correction factors for clinical seed configurations when edema characteristics can be measured or estimated.

100

Permanent implants in treatment of prostate cancer  

International Nuclear Information System (INIS)

Low-dose rate brachytherapy (LDR - BT) is one of the radiation methods that is known for several years in treatment of localized prostate cancer. The main idea of this method is to implant small radioactive seeds as a source of radiation, 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, however not as a palliative treatment. The application of permanent seeds implants is a curative treatment alternative in patients with organ-confined cancer, without extracapsular extension of the tumour. Nowadays three kinds of radionuclide (I-125, Pd-103, Cs-131) are in use worldwide. This technique is particular favorite in United States, in Europe however, high-dose rate brachytherapy method (HDR BT) is more popular in early staged prostate cancer treatment ( as a boost). HDR-BT monotherapy for early stage prostate cancer is still an investigational treatment. As monotherapy LDR-BT seems to be a reliable choice for early stage prostate cancer, according to low morbidity rate good results and short hospitalization. It is curative alternative of radical prostatectomy or external beam radiation (i.e. 3D CRT, IMRT) with comparable long-term survival and biochemical control and most favorable toxicity. The aim of this publication is to describe methods, indications, complications and selected results of prostate cancerns and selected results of prostate cancer LDR brachytherapy. (author)

101

[125I]Iodopride  

International Nuclear Information System (INIS)

Substituted benzamides are currently among the most selective antagonists at dopamine D-2 receptors, and high affinity ligands have been developed by substituting halogens into the aromatic ring of the benzamides. The authors report the high affinity, stereoselective, reversible, and sodium dependent binding of a new iodine-substituted benzamide, called [125I]iodopride, to a membrane preparation from rat corpus striatum. 5 refs.; 1 figure

102

Experimental determination of dosimetry parameters for Sinko 125I seed source using a modified polystyrene phantom  

International Nuclear Information System (INIS)

Successful treatment for permanent implant brachytherapy is based on accurate measurement of dosimetry parameters for the seed sources. Literature describes the application of various types of phantom to determine the AAPM TG-43 dosimetry parameters for permanent implant seeds. Previously we created a new type of phantom used to measure the dosimetry parameters of a high dose-rate 192Ir source. In this study, we modified the phantom to suit to a common type of 125I seed source (Sinko BT-125-1). The dose-rate constant, radial dose function and anisotropy function of this source were measured in detail and compared with the published values of other similar in-design 125I seed sources. The experimental results exhibit fairly small measurement uncertainties and good self-consistency. The modified phantom is demonstrated on the measurement of dosimetry parameters for the Sinko BT-125-1 125I seed, however, it could easily be used for similar measurements of other permanent implantation seed sources.

103

Experimental determination of dosimetry parameters for Sinko (125)I seed source using a modified polystyrene phantom.  

Science.gov (United States)

Successful treatment for permanent implant brachytherapy is based on accurate measurement of dosimetry parameters for the seed sources. Literature describes the application of various types of phantom to determine the AAPM TG-43 dosimetry parameters for permanent implant seeds. Previously we created a new type of phantom used to measure the dosimetry parameters of a high dose-rate (192)Ir source. In this study, we modified the phantom to suit to a common type of (125)I seed source (Sinko BT-125-1). The dose-rate constant, radial dose function and anisotropy function of this source were measured in detail and compared with the published values of other similar in-design (125)I seed sources. The experimental results exhibit fairly small measurement uncertainties and good self-consistency. The modified phantom is demonstrated on the measurement of dosimetry parameters for the Sinko BT-125-1 (125)I seed, however, it could easily be used for similar measurements of other permanent implantation seed sources. PMID:22766686

Duan, Yuting; Zhang, Menglong; Wang, Gang; Du, Liqing

2012-09-01

104

Antibiotic prophylaxis in permanent pacemaker implantation: a prospective randomised trial.  

OpenAIRE

BACKGROUND--Pacemaker pocket infection is a potentially serious problem after permanent pacemaker implantation. Antibiotic prophylaxis is commonly prescribed to reduce the incidence of this complication, but current trial evidence of its efficacy is conflicting. A large prospective randomised trial was therefore performed of antibiotic prophylaxis in permanent pacemaker implantation. The intention was firstly to determine whether antibiotic prophylaxis is efficacious in these patients and sec...

Mounsey, J. P.; Griffith, M. J.; Tynan, M.; Gould, F. K.; Macdermott, A. F.; Gold, R. G.; Bexton, R. S.

1994-01-01

105

Image fusion techniques in permanent seed implantation  

Directory of Open Access Journals (Sweden)

Full Text Available Over the last twenty years major software and hardware developments in brachytherapy treatment planning, intraoperative navigation and dose delivery have been made. Image-guided brachytherapy has emerged as the ultimate conformal radiation therapy, allowing precise dose deposition on small volumes under direct image visualization. In thisprocess imaging plays a central role and novel imaging techniques are being developed (PET, MRI-MRS and power Doppler US imaging are among them, creating a new paradigm (dose-guided brachytherapy, where imaging is used to map the exact coordinates of the tumour cells, and to guide applicator insertion to the correct position. Each of these modalities has limitations providing all of the physical and geometric information required for the brachytherapy workflow.Therefore, image fusion can be used as a solution in order to take full advantage of the information from each modality in treatment planning, intraoperative navigation, dose delivery, verification and follow-up of interstitial irradiation.Image fusion, understood as the visualization of any morphological volume (i.e. US, CT, MRI together with an additional second morpholo gical volume (i.e. CT, MRI or functional dataset (functional MRI, SPECT, PET, is a well known method for treatment planning, verification and follow-up of interstitial irradiation. The term image fusion is used when multiple patient image datasets are registered and overlaid or merged to provide additional information. Fused images may be created from multiple images from the same imaging modality taken at different moments (multi-temporalapproach, or by combining information from multiple modalities. Quality means that the fused images should provide additional information to the brachythe rapy process (diagnosis and staging, treatment planning, intraoperative imaging, treatment delivery and follow-up that cannot be obtained in other ways. In this review I will focus on the role of image fusion for permanent seed implantation.

Alfredo Polo

2010-10-01

106

Model 3500 125I brachytherapy source dosimetric characterization  

International Nuclear Information System (INIS)

Low-energy gamma-emitting isotopes encapsulated for permanent implant are routinely applied in brachytherapy, most notably for prostate cancer. Before clinical use of a new source design, a full dosimetric analysis and standardized calibration are essential. Results of experimental measurement and analysis are reported here for the I-PlantTM (Implant Sciences Corporation) 125I source, model 3500. Dose measurements were made using standard methods employing thermoluminscent dosimeters in a water equivalent plastic phantom. Precision machined bores in the phantom located dosimeters and source(s) in a reproducible fixed geometry providing for transverse-axis and angular dose profiles over a range of distances from 0.17 to 10 cm. The data were analyzed in terms of parameters recommended by AAPM TG-43. The dose-rate constant, ?=1.01 cGy/h U (±6%) (1 U=1 cGy cm2 h-1), was evaluated with reference to a TG-51 calibrated 60Co standard, accounting for dosimeter response differences between 60Co and 125I photons. The radial dose function, g(r), the anisotropy function, F(r,?), the anisotropy factor, phian(r), and the point-source approximation anisotropy constant, phi-baran, were derived from one- and two-dimensional dose distribution data measured in the phantom, accounting for finite dosimeter volume and with attention to inter-chip effects. The results confirm prior dosimetrits. The results confirm prior dosimetric characterization of the model 3500, and indicate that the new source is comparable to the MED3631-A/M and 6702 source designs and may substitute for model 6711 in permanent implants for the treatment of prostate cancer

107

Model 3500 {sup 125}I brachytherapy source dosimetric characterization  

Energy Technology Data Exchange (ETDEWEB)

Low-energy gamma-emitting isotopes encapsulated for permanent implant are routinely applied in brachytherapy, most notably for prostate cancer. Before clinical use of a new source design, a full dosimetric analysis and standardized calibration are essential. Results of experimental measurement and analysis are reported here for the I-Plant{sup TM} (Implant Sciences Corporation) {sup 125}I source, model 3500. Dose measurements were made using standard methods employing thermoluminscent dosimeters in a water equivalent plastic phantom. Precision machined bores in the phantom located dosimeters and source(s) in a reproducible fixed geometry providing for transverse-axis and angular dose profiles over a range of distances from 0.17 to 10 cm. The data were analyzed in terms of parameters recommended by AAPM TG-43. The dose-rate constant, {lambda}=1.01 cGy/h U ({+-}6%) (1 U=1 cGy cm{sup 2} h{sup -1}), was evaluated with reference to a TG-51 calibrated {sup 60}Co standard, accounting for dosimeter response differences between {sup 60}Co and {sup 125}I photons. The radial dose function, g(r), the anisotropy function, F(r,{theta}), the anisotropy factor, phi{sub an}(r), and the point-source approximation anisotropy constant, phi-bar{sub an}, were derived from one- and two-dimensional dose distribution data measured in the phantom, accounting for finite dosimeter volume and with attention to inter-chip effects. The results confirm prior dosimetric characterization of the model 3500, and indicate that the new source is comparable to the MED3631-A/M and 6702 source designs and may substitute for model 6711 in permanent implants for the treatment of prostate cancer.

Wallace, Robert E. E-mail: wallace@radonc.ucla.edu

2002-04-01

108

MR and CT image fusion for postimplant analysis in permanent prostate seed implants  

International Nuclear Information System (INIS)

Purpose: To compare the outcome of two different image-based postimplant dosimetry methods in permanent seed implantation. Methods and materials: Between October 1999 and October 2002, 150 patients with low-risk prostate carcinoma were treated with 125I and 103Pd in our institution. A CT-MRI image fusion protocol was used in 21 consecutive patients treated with exclusive brachytherapy. The accuracy and reproducibility of the method was calculated, and then the CT-based dosimetry was compared with the CT-MRI-based dosimetry using the dose-volume histogram (DVH) related parameters recommended by the American Brachytherapy Society and the American Association of Physicists in Medicine. Results: Our method for CT-MRI image fusion was accurate and reproducible (median shift 100 = 82% vs. 88%, p 90 = 96% vs. 115%, p < 0.05. Those results depend on the institutional implant technique and reflect the importance of lowering inter- and intraobserver discrepancies when outlining prostate and organs at risk for postimplant dosimetry. Conclusions: Computed tomography-MRI fused images allow accurate determination of prostate size, significantly improving the dosimetric evaluation based on DVH analysis. This provides a consistent method to judge his provides a consistent method to judge a prostate seed implant's quality

109

Permanent 125iodine implants for recurrent malignant gliomas  

International Nuclear Information System (INIS)

Purpose: To determine the efficacy and toxicity of permanent 125iodine implants for recurrent malignant gliomas. Methods and Materials: Between January 1989 and January:, 59 patients with histologically confirmed recurrent malignant gliomas (22 nonglioblastoma malignant gliomas, 37 glioblastoma multiforme at the time of implant) received a permanent 125iodine implant. Patients ranged in age from 13-74 years. The median ages for the overall group, nonglioblastoma (nonGBM), and glioblastoma (GBM) groups was 47 years, 39 years, and 53 years, respectively. Results: With a median follow-up of 40 months, the median survival for the 59 total patients is 1.34 years; nonGBM 2.04 years, GBM 0.9 years. Factors predictive for poor prognosis were GBM histology, age 60 years or more, target volume 17 cc or more, and/or tumor location within the corpus callosum or thalamus. Reoperations have been performed in 24 (40%) patients; 15 (25%) for tumor progression; 3 (5%) for radiation necrosis; 2 (3%) for skull necrosis/infection, and 4 (7%) for other reasons (Ommaya reservoir insertion, catheter removal, hematoma evacuation). Conclusion: Permanent 125iodine implants in selected patients with recurrent malignant gliomas are associated with reasonable long-term survival and a low risk of complications. Given the low incidence of radiation necrosis, future plans are to increase dose rate and/or total dose delivered with the permanent implantwith the permanent implant

110

Development and initial testing of a permanently implantable centrifugal pump.  

Science.gov (United States)

To be able to salvage heart failure patients, the need for an economical permanent ventricular assist device is increasing. To meet this increasing demand, a miniaturized centrifugal blood pump has been developed as a permanently implantable device. The Gyro permanently implantable model (PI-601) incorporates a sealless design with a blood stagnation free structure. The pump impeller is magnetically coupled to the driver magnet in a sealless manner. This pump is atraumatic and antithrombogenic and incorporates a double pivot bearing system. A miniaturized actuator was utilized in this system in collaboration with the University of Vienna. The priming volume of this pump is 20 ml. The overall size of the pump actuator package is 53 mm in height and 65 mm in diameter, 145 ml of displacement volume, and 305 g in weight. Testing to date has included in vitro hydraulic performance and hemolysis. This pump can provide 5 L/min against a 110 mm Hg total pressure head at 2,000 rpm and 8 L/min against 150 mm Hg at 2,500 rpm. The normalized index of hemolysis (NIH) value of this pump was 0.0028 g/100 L at 5 L/min against 100 mm Hg. A preliminary anatomical study revealed the possibility of the implantability of 2 such systems in biventricular bypass at a preperitoneal location. This system is feasible for use as a permanently implantable biventricular assist device. PMID:9212924

Nakazawa, T; Takami, Y; Benkowski, R; Ohtsubo, S; Yukio, O; Tayama, E; Ohtsuka, G; Niimi, Y; Glueck, J; Sueoka, A; Schmallegger, H; Schima, H; Wolner, E; Nosé, Y

1997-07-01

111

Permanent and temporary pacemaker implantation after orthotopic heart transplantation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english PURPOSE:To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR) between March 1985 and [...] May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for pemanent pacing and the clinical follow-up. RESULTS: Fourteen of 114 (12%)heart transplant recipients required temporary pacing and 4 of 114 (3.5%) patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5%) and atrioventricular (AV) block in 3 patients (21.4%). The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75%) and atrioventricular (AV) block in 1 patient (25%). We observed rejection in 3 patients (21.4%) who required temporary pacing and in 2 patients (50%) who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4%) with temporary pacing. Seven of the 14 patients (50%) died during follow-up. CONCLUSION: Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.

Fernando, Bacal; Edimar A., Bocchi; Marcelo L. C., Vieira; Neusa, Lopes; Luiz Felipe, Moreira; Alfredo, Fiorelli; Roberto, Costa; Martino, Martinelli; Noedir A. G., Stolf; Giovanni, Bellotti; José Antonio F., Ramires.

2000-01-01

112

Permanent and temporary pacemaker implantation after orthotopic heart transplantation  

Directory of Open Access Journals (Sweden)

Full Text Available PURPOSE:To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for pemanent pacing and the clinical follow-up. RESULTS: Fourteen of 114 (12%heart transplant recipients required temporary pacing and 4 of 114 (3.5% patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5% and atrioventricular (AV block in 3 patients (21.4%. The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75% and atrioventricular (AV block in 1 patient (25%. We observed rejection in 3 patients (21.4% who required temporary pacing and in 2 patients (50% who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4% with temporary pacing. Seven of the 14 patients (50% died during follow-up. CONCLUSION: Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.

Fernando Bacal

2000-01-01

113

192Ir or 125I prostate brachytherapy as a boost to external beam radiotherapy in locally advanced prostatic cancer: A dosimetric point of view  

International Nuclear Information System (INIS)

Purpose: This work aims at comparing the dosimetric possibilities of 125I or 192Ir prostate brachytherapy (Bt) as a boost to external beam radiotherapy in the treatment of locally advanced adenocarcinoma. Methods and materials: From 1/1997 to 12/2002, 260 patients were treated. Until 12/2001 a low dose rate (LDR) treatment with 192Ir wires was used, later replaced by a high dose rate (HDR) delivered with an 192Ir stepping source technology. For the present work, we selected 40 patients including the last 20 treated, respectively, by LDR and HDR. The planning CT Scans of all these 40 patients were transferred into the 3D ProwessR system for 125I permanent implants design according to the Seattle method. The reference data for dosimetric comparisons were the V100 and the prescribed dose for 192Ir as well as the dose delivered with 125I techniques to the 192Ir V100. We compared V100-150 data as well as doses to the organs at risks (OR) and cold spots (CS). Results: The V100 is 85.3±8% for 192Ir LDR and 96±2% for HDR techniques (P125I, the 192Ir LDR mode induces higher hyperdosage volumes inside the CTV but also more CS, while maximal doses to urethra and rectum are, respectively, 17 and 39% less with 125I (P192Ir HDR mode, 125I Bt induces higher mode, 125I Bt induces higher hyperdosage volumes and slightly more CS deliberately planned around the bladder neck. If delivered doses to urethra are identical, those to the 20% anterior part of the rectum are 33% less with 125I (P125I Bt technique was only possible in 24 out of the 40 patients studied due to pelvic bone arch interference. Conclusions: At the present time, there is no evident dosimetric superiority of one Bt method when all the criteria are taken into account. However, improving Bt techniques to implant any prostatic size could found the superiority of the 125I or permanent implants. 125I indeed allows large hyperdosage volumes inside the CTV in comparison with 192Ir HDR techniques while lowering doses to OR and minimizing CS

114

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

International Nuclear Information System (INIS)

The purpose of this study was to evaluate the integrity of eight commercially-available low-activity Iodine-125 (125I) 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 125I sources included in this study were 125I Source 2301 (Best); I-Plant (MedTech), IoGold (Mentor), Oncura (Amersham Health), ProstaSeed (UroCor), SelectSeed (Nucletron), SourceTech (Bard), and Symmetra (UroMed). The sh (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 were determined to have the highest g(r) values, with ProstaSeed and SelectSeed having the lowest values. 125I Source 2301 and IoGold required less activity per seed to achieve the same dose to the V100-PTV due to the higher dose rate and anisotrophy constants (xwedge.phi). The seed types with silver were less penetrating and resulted in the production of characteristic x-rays that modified the energy spectrum and influenced the radial function. The seeds requiring the lowest activity showed the highest dose to the anterior rectal wall, a posterior adjacent structure; the urethra, an interior structure; and the bulb, an inferior structure. This study was designed to investigate the integrity of eight different commercially-available seed types, and their dependence on the g(r) in seed choice. It was determined that the dose rate constant and anisotropy factor determine the activity needed for implantation but a strong dependence on the radial function was found to effect the doses to the adjacent structures

115

The initial experience of 125I seeds brachytherapy for patients with oral carcinoma  

International Nuclear Information System (INIS)

Objective: To evaluate the efficacy of 125I radioactive seeds implantation and 125I plaque brachytherapy for oral carcinoma. Methods: Eighteen patients with oral carcinoma confirmed by cytology or histopathology were included in this study, Twelve patients with tongue cancer and six patients with gingival carcinoma, there were 20 ulcerative lesions and 10 metastatic cervical lymph nodes. The mean diameter is (2.3±0.7) cm and (2.8±1.7) cm respectively. The patients were treated with both interstitial implantation of 125I seeds and 125I plaque brachytherapy or with 125I plaque brachytherapy only according to patient's individual conditions. The metastatic cervical lymph nodes were treated with CT-guided interstitial implantation of 125I seeds. The sizes of ulcerative lesions and lymph nodes were observed at 1,3,6 months following treatment, and statistical analysis of the sizes of ulcerative lesions were evaluated by paired t-test. Results: After 1,3,6 months follow-up, The mean diameters of ulcerative lesions were (2.1 ± 0.6 )cm (t=3.559, P125I implantalapsed alter 125I implantation again. Patients were followed for 7 to 28 months, all patients were still alive. Conclusion: Interstitial 125I radioactive seeds implantation and 125I plaque brachytherapy provide an effective, sale treatment for oral cancer. (authors)

116

Permanent and temporary pacemaker implantation after orthotopic heart transplantation  

OpenAIRE

PURPOSE:To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR) between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for pemanent pacing and the clinical follow-up. RESULTS: Fourteen...

Fernando Bacal; Bocchi, Edimar A.; Vieira, Marcelo L. C.; Neusa Lopes; Luiz Felipe Moreira; Alfredo Fiorelli; Roberto Costa; Martino Martinelli; Stolf, Noedir A. G.; Giovanni Bellotti; Ramires, Jose? Antonio F.

2000-01-01

117

Calculated Micro-dosimetric characteristics of 125I and 103Pd brachytherapy seeds at different depths in water  

International Nuclear Information System (INIS)

Both 125I and 103Pd sources have been widely used in the permanent prostate implant. An important consideration for the choice of brachytherapy sources is the relative biological effectiveness (RBE) for the source/seed used in the implantation. As RBE is closely related to the Micro-dosimetric parameter, it is desirable to calculate the dose mean lineal energies for both 125I and 103Pd at various radial distances to the seed surface. Monte Carlo simulation was performed for photons emitted from 125I and 103Pd. Energy depositions from photons and all their secondary electrons were tracked. Dose distributions of lineal energy, d(y), were calculated for spheres of 1 ?m in diameter and at various radial distances to the seed surface. From the dose distribution of lineal energy, the dose mean lineal energy, yD, was derived. The results showed that the radiation qualities are constant in the distance range from 0.5 to 5 cm. In this distance range, the quality factor, relative to gamma rays from 60Co, is 2.2 for 125I and 2.5 for 103Pd. (authors)

118

125I therapy of hyperthyroidism  

International Nuclear Information System (INIS)

In recent years increasing interest is shown in the use of 125I for the therapy of hyperthyroidism, instead of the traditional 131I, based on the postulate that there is a relative sparing of the reproductive integrity of the thyroid follicular cell and a consequent possibility of smaller incidence of hypothyroidism after therapy. Dosimetric and radiobiological bases of this postulate are first described in this paper and then a brief review of the results of the pilot clinical trials conducted at different centers using 125I for the management of hyperthyroidism is given. (orig./MG)

119

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

Science.gov (United States)

The purpose of this study was to evaluate the integrity of eight commercially-available low-activity Iodine-125 (125I) 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), 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 (Delta) 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 were determined to have the highest g(r) values, with ProstaSeed and SelectSeed having the lowest values. 125I Source 2301 and IoGold required less activity per seed to achieve the same dose to the V100-PTV due to the higher dose rate and anisotrophy constants (Delta.phi). The seed types with silver were less penetrating and resulted in the production of characteristic x-rays that modified the energy spectrum and influenced the radial function. The seeds requiring the lowest activity showed the highest dose to the anterior rectal wall, a posterior adjacent structure; the urethra, an interior structure; and the bulb, an inferior structure. This study was designed to investigate the integrity of eight different commercially-available seed types, and their dependence on the g(r) in seed choice. It was determined that the dose rate constant and anisotropy factor determine the activity needed for implantation but a strong dependence on the radial function was found to effect the doses to the adjacent structures. PMID:15324917

Pickett, Barby; Pouliot, Jean

2004-01-01

120

Temporary and Permanent Inferior Vena Cava Filter Combination in a Young Patient: To Implant or Not to Implant?  

International Nuclear Information System (INIS)

The decision to implant vena cava filters, either temporary or permanent, is difficult in young patients. We present the case of a young man with pulmonary embolism in whom temporary and permanent inferior vena cava filters were implanted. The decision process is discussed in relation to the current literature

121

Inverse planning optimization for hybrid prostate permanent-seed implant brachytherapy plans using two source strengths.  

Science.gov (United States)

The purpose is to demonstrate the ability to generate clinically acceptable prostate permanent seed implant plans using two seed types which are identical except for their activity. The IPSA inverse planning algorithms were modified to include multiple dose matrices for the calculation of dose from different sources, and a selection algorithm was implemented to allow for the swapping of source type at any given source position. Five previously treated patients with a range of prostate volumes from 20-48 cm3 were re-optimized under two hybrid scenarios: (1) using 0.32 and 0.51 mGy m2 / h 125I, and (2) using 0.64 and 0.76 mGy m2 / h 125I. Isodose lines were generated and dosimetric indices , V150Prostate, D90Prostate, V150Urethra, V125Urethra, V120Urethra,V100Urethra, and D10Urethra were calculated. The algorithm allows for the generation of single-isotope, multi-activity hybrid brachytherapy plans. By dealing with only one radionuclide, but of different activity, the biology is unchanged from a standard plan. All V100Prostate were within 2.3 percentage points for every plan and always above the clinically desirable 95%. All V150Urethra were identically zero, and V120Urethra is always below the clinically acceptable value of 1.0 cm3. Clinical optimization times for the hybrid plans are still under one minute, for most cases. It is possible to generate clinically advantageous brachytherapy plans (i.e. obtain the same quality dose distribution as a standard single-activity plan) while incorporating leftover seeds from a previous patient treatment. This method will allow a clinic to continue to provide excellent patient care, but at a reduced cost. Multi-activity hybrid plans were equal in quality (as measured by the standard dosimetric indices) to plans with seeds of a single activity. Despite the expanded search space, optimization times for these studies were still under two minutes on a modern day laptop and can be reduced to below one minute in a clinical setting. With the typical cost of a set of PPI seeds on the order of thousands of dollars, it is possible to reduce the cost of brachytherapy treatments by allowing for easier use of seeds left over from a previous patient or unused due to a cancelled treatment. PMID:20717078

Cunha, J Adam M; Pickett, Barby; Pouliot, Jean

2010-01-01

122

PSA nadir after 125I prostate brachytherapy  

International Nuclear Information System (INIS)

The purpose of this study was to evaluate the prostate-specific antigen (PSA) kinetics and nadir of PSA failure after permanent 125I prostate brachytherapy. The study included 660 patients with a potential minimum follow-up of 5 years. Patients who met the Phoenix definition of PSA failure were identified. The PSA decreased gradually to less than 0.2 ng/mL even after 5 years for many patients. The median PSA nadir was 0.09 ng/mL. Neoadjuvant hormone therapy had little effect on PSA nadir. The PSA nadir <=0.2 ng/mL or current nadir <=0.4 ng/mL seemed to be a good marker as a successful treatment. (author)

123

Comparison of day 0 and day 14 dosimetry for permanent prostate implants using stranded seeds  

International Nuclear Information System (INIS)

Purpose: To determine, using MRI-based dosimetry (Day 0 and Day 14), whether clinically significant changes in the dose to the prostate and critical adjacent structures occur between Day 0 and 14, and to determine to what degree any changes in dosimetry are due to swelling or its resolution. Methods and Materials: A total of 28 patients with a permanent prostate implant using 125I rapid strands were evaluated at Days 0 and 14 by CT/MRI fusion. The minimal dose received by 90% of the target volume (prostate D9), percentage of volume receiving 100% of prescribed minimal peripheral dose (prostate V10), external sphincter D9, and 4-cm3 rectal volume dose were calculated. An acceptable prostate D9 was defined as D9 >90% of prescription dose. Prostate volume changes were calculated and correlated with any dosimetry change. A paradoxic dosimetric result was defined as an improvement in D9, despite increased swelling; a decrease in D9, despite decreased swelling; or a large change in D9 (>30 Gy) in the absence of swelling. Results: The D9 changed in 27 of 28 patients between Days 0 and 14. No relationship was found between a change in prostate volume and the change in D9 (R2 = 0.01). A paradoxic dosimetric result was noted in 11 of 28 patients. The rectal dose increased in 23 of 28 patients, with a >30-Gy change in 6. The external sphith a >30-Gy change in 6. The external sphincter D9 increased in 19 of 28, with a >50-Gy increase in 6. Conclusion: The dose to the prostate changed between Days 0 and 14 in most patients, resulting in a change in clinical status (acceptable or unacceptable) in 12 of 28 patients. Profound increases in normal tissue doses may make dose and toxicity correlations using Day 0 dosimetry difficult. No relationship was found between the prostate volume change and D9 change, and, in 11 patients, a paradoxic dosimetric result was noted. A differential z-axis shift of stranded seeds vs. prostate had a greater impact on final dosimetry and dose to critical adjacent tissues than did prostate swelling. These findings challenge the model that swelling is the principal cause of dosimetric changes after implantation. Stranded seeds may have contributed to this outcome. On the basis of these findings, a change in technique to avoid placement of stranded seeds inferior to the prostate apex has been adopted. These results may not apply to implants using single seeds within the prostate

124

Conformal prostate brachytherapy guided by realtime dynamic dose calculations using permanent 125iodine implants: technical description and preliminary experience  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: English Abstract in spanish Objetivo: El tratamiento con braquiterapia de baja tasa de dosis (LDR) con implantes permanentes de 125-I o 103Pb, constituyen en la actualidad una opción terapéutica en los pacientes con cáncer de próstata de bajo riesgo. La variación observada en el posicionamiento espacial de la próstata, así com [...] o en el volumen y contorno prostático entre las imágenes obtenidas durante la planificación y posteriormente durante la intervención, hacen dudar de la exactitud de dosificación, en los pacientes tratados con la técnica de preplanificación. Analizamos la técnica basada en la planificación previa, la planificación intraoperatoria interactiva, así como nuestro proceder actual de planificación intraoperatoria por cálculo dinámico en tiempo real y los motivos que nos llevaron a realizar este cambio de técnica. Métodos: Con el cálculo del volumen prostático preoperatorio por ecografía transrectal, determinamos la posibilidad de realizar el implante en base a las consideraciones anatómicas existentes y decidimos la actividad por semilla y la actividad total del implante. El día de la intervención comprobamos de nuevo la volumetría, obtenemos de nuevo las imágenes ecográficas de base a apex, ayudados por un stepper motorizado que va conectado con el ecógrafo y el planificador. Cada aguja que se coloca en la posición que deseamos y no en una coordenada obligada, se identifica en el planificador en la posición real, una vez colocadas todas las agujas y obtenidas unas primeras isodosis adecuadas, realizamos una cistoscopia flexible y a continuación sembramos, identificando todas y cada una de las semillas en la retirada de la aguja guía ecográficamente, con lo que nos permite obtener una postplanificación intraoperatoria en tiempo real y hacer las correcciones oportunas en el propio acto quirúrgico. Realizamos un implante periférico puro. Resultados: Iniciamos los tratamientos con braquiterapia de baja tasa de dosis en 1.999. Superadas las 700 intervenciones, hemos evaluado a los primeros 63 pacientes tratados con la técnica de cálculo dinámico de dosis en tiempo real por presentar un seguimiento mínimo de 10 meses. El tiempo medio del proceso fue de 90 minutos. La media de seguimiento para los 63 pacientes estudiados fue 20 meses con un rango entre 10 y 36 meses. Un 55% de los pacientes fueron estadiados como T1c, 36% T2a y 9% T2b. En el 81% de los pacientes el Gleason fue Abstract in english Objetive: Low dose rate (LDR) prostate brachytherapy (permanent 125I or 103Pd seeds) is an accepted treatment option for low risk prostate cancer patients. However, differences in prostate spatial location, volume and gland deformation between the images obtained during pre-planning and later on dur [...] ing the implant procedure prevent the pre-planned intended dose to be accurately delivered. We are reporting on a new technique based on interactive real-time dynamic intra-operative dose calculation with avoidance of post-implant CT for final dosimetry. The reasons leading us to implementing this new technique are discussed and preliminary results reported. Methods: A pre-planning TRUS for volumetric analysis is performed in all our patients prior to implantation. This TRUS accomplishes two objectives: 1) assessment of implantability of the gland, of organs at risk and anatomical considerations and 2) determination of seed activity and total number of seeds. On the day of the implant, new TRUS images from base to apex are obtained using a motorized stepper connected to the ultrasound and planning system. Each real time needle position placed on the target is identified and capture by the planning system in the true position. Once all real needle positions have been captured, dosimetry is performed intra-operatively and the physician approves the corresponding isodoses on real time. Flexible cystoscopy is then performed followed by seed placement. Each seed implanted is then identified upon withdrawing the needle using TRUS

Pedro J., Prada; German, Juan; José, Fernández; González-Suárez, H; Álvaro, Martínez; José, González; Ana, Alonso.

2006-11-01

125

Local nuclear orientation of 125I in tin and graphite using defect induced electric field gradients  

International Nuclear Information System (INIS)

Defect-induced field electric field gradients, generated by ion implantation of 125I in ?- and ?-Sn and in graphite, were used to obtain local nuclear orientation at low temperatures. The resulting nuclear orientation at the parent 125I state was detected by 125Te Moessbauer spectroscopy. From the measured nuclear quadrupole interaction strengths at the parent state, the electric field gradient and the cooling behavior of implanted atoms were studied. (orig.)

126

Filling carbon nanotubes with Na125I  

International Nuclear Information System (INIS)

Carbon nanotubes (CNTs) are filled with Na125I after purification and opening. The behaviour of filling, washing and release of Na125I from CNTs are investigated. CNTs samples filled with NaI under optimum filling condition are characterized by HREM, SEM and EDS. The results indicate that the Na125I are filled into the CNTs and can release slowly. It shows that the radioactive tracer technique is effective for the study of filling and release behaviour of CNTs

127

Long-term advantages of permanent expandable implants in breast aesthetic surgery.  

Science.gov (United States)

Permanent expandable implants are widely used in breast reconstructive surgery, but their use in aesthetic surgery is still uncommon. Previous reports on breast expansion-augmentation using permanent expandable implants focused on immediate and early advantages but failed to evaluate long-term benefits, because the reservoir was removed a few months after implantation and the ability to adjust the implant size was lost. Since 1986, we have used permanent expandable implants in 129 women for unilateral or bilateral breast augmentation using the following approach: implants were positioned submuscularly through a transaxillary incision; the filling port was placed a few centimeters below the incision and permanently retained; the implants were positioned underinflated and then overexpanded starting 2 weeks after implantation; after a period of overinflation, deflation to the preoperatively planned volume was scheduled; patients' suggestions regarding final volume adjustments were followed; the effects of repeated overinflations and deflations were investigated in several different conditions. Permanent expandable implants offer unique long-term technical and psychological advantages in the management of highly demanding patients and in the following clinical situations: pregnancy, impending capsular contracture, contralateral progressive ptosis, tubular breasts(s), difficult mammographic examination, spontaneous deflation, and rippling. Disadvantages include economical cost, port-related problems, and repeated requests by patients for volume changes. Saline permanent expandable implants allowed less flexibility in adjusting the breast size and caused discomfort when overexpanded. Permanent expandable implants in breast aesthetic surgery offer several advantages, and because patients can play an active role in deciding volume adjustments, compliance is very high. PMID:9623844

Berrino, P; Casabona, F; Santi, P

1998-06-01

128

Occupational exposure in prostate permanent implants with I-125 seeds  

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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)

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

129

Quality indicators for permanent I-125 prostate seed implants : seven years post implant dosimetry evaluation  

International Nuclear Information System (INIS)

Full text: The aim of the current work is to assess the progress of prostate implant quality via post implant dosimetry over a 7-year time period. The roles of post implant dosimetry (PID) after permanent 1-125 implant are to: identify suboptimal implants; assess the dosimetric quality indicators and evaluate dose to organs at risk. The 7-years PID learning-curve shows clear changes in dosimetric trend. Beside the expected improvement in technique the following factors were investigated: the replacement of the computed tomography (CT)-delineation based PID with ultrasound (US)-CT fusion based, and the evolution and influence of parameters such as 090 and V I 00. The correlation between dosimetric parameters and clinical outcome was also evaluated. Results A study on 30 patients showed manual target contouring on CT tends to overestimate the prostate volume when compared to ultrasound data (mean difference 38.3%), translating to CT based D90 values being lower than US-CT D90 by an average of 6%. There was 4.7% patient relapse and urinary retention was reported in 2.7% of the patients. CT-based PID was found less reliable than US-CT fusion due to target overestimation. This result shows the biased interpretation of low D90 based on CT targeting and may not relate to patient relapse data. The low urinary retention statistics are in accordance with the PID data for the organ, as only 5.2% of patients had their PID D I 0 >218 Gy, i.e. abovets had their PID D I 0 >218 Gy, i.e. above recommended GEC-ESTRO guidelines. Besides the 'learning' component, the 7-years PID D90 curve is influenced by PID technique.

130

CT-guided 125I seed brachytherapy for abdominal metastatic lymph nodes  

International Nuclear Information System (INIS)

Objective: To investigate the safety and clinical efficacy of CT-guided radioactive seed 125I implantation in treating abdominal and retroperitoneal metastatic lymph nodes. Methods: Twenty-seven patients with pathologically proved abdominal malignancy (17 males and 10 females) were enrolled in this study. The primary tumors included liver cancer (n=13), pancreatic cancer (n=8) and gastric cancer (n=6). A total of 31 abdominal and peritoneal metastatic lymph nodes (diameter of 2.2-4.7 cm) were detected and CT-guided radioactive seed 125I implantation was carried out. Halarism 125I experience formula was used to design the distribution of seed 125I. Under CT guidance, 125I seeds were implanted into the metastatic lymph nodes at a distance interval of 1.0-1.5 cm. After implantation, CT scanning was immediately performed to check the distribution of 125I seeds to observe the possible complications. CT or PET-CT re-examination was performed at 3 months after 125I seed implantation. Results: Of the 27 patients, 125I seed implantation was successfully accomplished in 25 (92.6%) at the first time and the particle distribution met the radioactive requirements well. In the remaining 2 patients the particle distribution did not meet the requirements and replacement of 125I seed had to be made. In this group, 8 patients had severe pain before treatment and in six of them the pain was markedly relieved at 1-3 weeks after seed 125I implantation, with a response rate of 75.0%. The patients were followed up for three months and all the 27 patients survived. According to the results of CT or PET-CT re-examination, 12 of 27 patients (44.4%) achieved complete remission (CR), 8 (29.6%) achieved partial remission (PR), 4 (14.8%0 showed no change (NC) and 3 (11.1%) had progressive disease (PD). The overall response rate was 74.1% (20/27). No severe complications, such as acute pain, massive bleeding, infection and bone marrow suppression, occurred. Conclusion: For the treatment of abdominal and retroperitoneal metastatic lymph nodes CT-guided interstitial implantation of radioactive seed 125I is effective, minimal invasive and safe with few complications. (authors)

131

Absorbed dose determination for interstitial 125I boost therapy  

International Nuclear Information System (INIS)

Iodine-125 implants are being used to boost external beam treatments of unresectable pancreas and lung tumors. Calculations of the 125I activity required to achieve a specific average peripheral dose are presented as a function of the average tumor dimension for spherical, ellipsoidal, and cylindrical implants. Both uniform and random seed spacings are investigated. The results indicate that the average peripheral dose is relatively insensitive to the seed distribution as well as to the seed activity. The average tumor dose is typically 20% greater than the average peripheral dose

132

A permanent breast seed implant as partial breast radiation therapy for early-stage patients: A comparison of palladium-103 and iodine-125 isotopes based on radiation safety considerations  

International Nuclear Information System (INIS)

Purpose: A permanent breast seed implant (PBSI) technique has been developed as a new form of partial adjuvant radiation therapy for early-stage breast cancer. This study compares iodine-125 (125I) and palladium-103 (103Pd) isotopes by examining the exposure and effective dose (ED) to a patient's partner.Methods and Materials: A low-energy survey meter was used to measure exposure rates as a function of bolus thickness placed over 103Pd or 125I seeds. A general mathematical expression for the initial exposure rate at 1 m (xo,1m) from the skin surface as a function of the implant size, R, and the distance between the skin surface and the implant, d, was derived. Also, a second general equation is proposed to calculate the ED to the patient's partner.Results: The initial exposure rate at 1 meter and the ED are calculated as follows: xo,1m = (3?)/2R3·?3 [e-?(2R+d)(?R + 1) + e-?·d(?R - 1)], and ED = aRb · [e-c(2R+d) · (cR + 1) + e-cd -bar (cR - 1)]. For 125I, the parameters are: ? = 0.154409, ? = 0.388460, a = 197, b = -0.95, and c = 0.38846. For 103Pd, they are: ? = 0.06877, ? = 0.421098, a = 18.6, b -0.78, and c = 0.421098. For implant diameters varying from 2 to 6 cm and skin-to-implant distances varying from 0.7 to 4 cm, the ED is consistently below 2.6 mSv using the 103Pd isotope,he 103Pd isotope, but more than 5 mSv in many instances and possibly up to 20 mSv using 125I.Conclusions: PBSI using 103Pd seeds appears safe because the patient's partner ED is consistently below 5 mSv. The125I isotope is not recommended for PBSI

133

Sexual function after permanent seed implant prostate brachytherapy  

International Nuclear Information System (INIS)

The aim of this study was to evaluate the long-term effects of permanent seed implant prostate brachytherapy (BT) on sexual function (SF). From September 2003 to July 2005, 56 patients underwent radical retropubic prostatectomy (RRP) without any hormone therapy, while 353 patients had undergone BT without any adjuvant hormone therapy in a single institute. Out of these 353 patients in the BT group, 305 patients received neoadjuvant hormone therapy (BT NHT + group), while 48 did not (BT NHT - group). SF was prospectively evaluated using the UCLA Prostate Cancer Index (UCLA-PCI). Potency was defined as the UCLA-PCI Q26 point of ?3. The preimplant UCLA-PCI scores of SF for BT NHT - and BT NHT + groups were 50.9 and 13.4, respectively. The SF score of the NHT - group post operatively decreased to 38.9 within 6 months, but was maintained at the same level after that. With the recovery of the androgen, SF score of the NHT + group improved after BT: however, it did not reach up to that of the NHT - group. In the univariate analysis, patient's age was the only predictive factor for SF after BT. Thirty-four out of 48 patients in the BT NHT - group and 23 out of 56 patients in the RRP group showed adequate potency before surgery. Their 5-year potency preservation rate was 73.6% in the BT NHT - group and 4.3% in the RRP group. SF slightly decreased immediately after BT but was usually maintained during the course observation for 5 years. The 5-year SF preservation rate after B The 5-year SF preservation rate after BT was 73.6%. (author)

134

Preparation of 125I FSH hormone  

International Nuclear Information System (INIS)

Labelling of human FSH of pituitary origin with 125I and its purification are described. Suitable parameters are selected for the use of radioimmunologic technique for FSH dosage in human serum. (author)

135

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

International Nuclear Information System (INIS)

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 103Pd-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 125I-seeds and 103Pd-implanted stents on the VSMC proliferation, with or without fetal bovine serum (FCS), were investigated through cell counting methods and 3H-TDR implementation tests. It was shown that (1) 10% FCS significantly promoted the DNA synthesis of VSMC (P125I-seeds and 103Pd-implanted stents inhibited the VSMC DNA synthesis in dose-dependent manner, regardless of 10% FCS inducement. At lower radioactive doses, neither 125I-seeds (18.5-74 kBq) nor 103Pd-implanted stents (1.48-2.96 MBq) exhibited distinctive effects on the VSMC DNA synthesis (P>0.05); and (3) 48 hour exposure from 125I-seeds at 128 kBq or 10'3Pd-implanted stents at 7.4 MBq did not result in VSMC morphological alteration, but 125I-seeds at 370 kBq caused cells' morphological changes. Therefore both 125I-seeds and 103Pd-implanted stents inhibit the in vitro VSMC DNA synthesis, and the inhibition effects are significantly related to their efects are significantly related to their exposure duration and doses. (authors)

136

Moving Toward Focal Therapy in Prostate Cancer: Dual-Isotope Permanent Seed Implants as a Possible Solution  

International Nuclear Information System (INIS)

Purpose: 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. Methods and Materials: 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%. Results: 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-dive 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. Conclusions: 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.

137

Local relapses after prostatic curie-therapy by permanent implants: radio-resistant prostate cancers or bad quality implant; Rechutes locales apres curietherapie prostatique par implants permanents: cancers de prostate radioresistants ou mauvaise qualite de l'implantation?  

Energy Technology Data Exchange (ETDEWEB)

The assessment of the quality of a permanent implant of grains for a prostate cancer treatment is based on the dosimetric plan performed before the grain implantation or shortly after. The authors report a study of the correlation between 'under-dosed' areas assessed at the time of relapse, and intra-prostatic relapse sites. The study is based on 24 cases of proved intra-prostatic relapse. The prostatic volume has been divided into 12 areas, and three types of under-dosing have been defined. Parameters are the dose received by 90 per cent of the volume, and the volume receiving 100 per cent of the dose. A correlation appears between positive biopsies and 'under-dosing'. This corresponds to a bad quality implantation of grains for patients in a situation of prostatic relapse after implantation. Short communication

Crehange, G.; Krishnamurthy, D.; Cunha, A. J.; Gros, S.; Pickett, B.; Hsu, I.C.; Gottschalk, A.R.; Pouliot, J.; Roach III, M. [UCSF Radiation Oncology, San Francisco (United States)

2011-10-15

138

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

International Nuclear Information System (INIS)

Objective: To explore the effectiveness and safety of the combined multi-disciplinary techniques with 125I 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 125I seeds implantation, B group with 125I 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 125I 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 125I seeds implantations, but it seems more quickly relief or recovery was achieved in the latter. (authors)

139

Treatment planning for permanent and temporary percutaneous implants with custom made templates  

International Nuclear Information System (INIS)

Nine patients who were presented at MSKCC with primary or recurrent pelvic or head and neck tumors and for whom surgery or further external radiation were excluded, were treated with percutaneous permanent or temporary implants, with individual pre-treatment planning and custom made templates. The tumor dose distributions achieved were as good as for implants performed at the time of surgical exploration. No serious complications have been encountered

140

Relation of QRS Width in Healthy Persons to Risk of Future Permanent Pacemaker Implantation  

OpenAIRE

In the setting of acute myocardial infarction, prolongation of the QRS interval on an electrocardiogram identifies patients at risk of needing permanent pacemaker implantation. However, the implications of a prolonged QRS in healthy individuals are unclear, especially since the QRS prolongation encountered in this setting is typically mild. We studied the relation between QRS duration and incident pacemaker implantation in a community-based cohort of 8,311 individuals (mean age 54 years, 55% ...

Cheng, Susan; Larson, Martin G.; Keyes, Michelle J.; Mccabe, Elizabeth L.; Newton-cheh, Christopher; Levy, Daniel; Benjamin, Emelia J.; Vasan, Ramachandran S.; Wang, Thomas J.

2010-01-01

141

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

OpenAIRE

During the past decade, permanent radioactive source implantation of the prostate has become the standard of care for selected prostate cancer patients, and the techniques for implantation have evolved in many different forms. Although most implants use 125I or 103Pd sources, clinical use of 131Cs sources has also recently been introduced. These sources produce different dose distributions and irradiate the tumors at different dose rates. Ultrasound was used originally to guide the planning a...

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

2009-01-01

142

Effectiveness of Permanent Implantable Catheter (Polysite in Children with Cancer  

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Full Text Available AbstractBackground Totally implantable central venous access devices (ports have been available for over 10 years, but have not been achieved widespread use in pediatric oncology patients. Ports facilitate the administration of chemotherapy in children with cancer. Materials and Methods In this study, we investigated early complications of implantable central venous access devices in children who suffered from different type of cancer. All of the complications were recorded by staff nurses by checklist for one week. This study included 68 patients with different cancer (lymphoma-leukemia-sarcoma and wilms’ tumor who were treated between April 2007 and November 2011 in oncology department of Dr Sheikh hospital, Mashhad University of medical science. ResultsVenous ports were placed in 26 (38.2% girls and 42 (61.8% boys aged between 2 and 12 years (mean: 6 years.We implanted all of the venous ports in patients for chemotherapy, and port implantation procedures were performed by one experienced Pediatric Surgery. 3 cases (4.4% have needle access site infections which were controlled with starting of antibiotics. Catheter leakage in 3 cases (4.4%, port-catheter disconnection in 4(5.8% cases, Occlusion of the system in 5 cases (7.4%. In this period, there were no major complications.Conclusion With proper placement technique and adequate nursing care, they represent a definite improvement in child cancer therapy. Ports can provide satisfactory for the majority of pediatric oncology patients, with a low risk of line-related complications and a high degree of acceptability to children and their parents.

Hashemizadeh Hayede

2012-03-01

143

Continuous and low-energy 125I seed irradiation changes DNA methyltransferases expression patterns and inhibits pancreatic cancer tumor growth  

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Full Text Available Abstract Background Iodine 125 (125I seed irradiation is an effective treatment for unresectable pancreatic cancers. However, the radiobiological mechanisms underlying brachytherapy remain unclear. Therefore, we investigated the influence of continuous and low-energy 125I irradiation on apoptosis, expression of DNA methyltransferases (DNMTs and cell growth in pancreatic cancers. Materials and methods For in vitro 125I seed irradiation, SW-1990 cells were divided into three groups: control (0 Gy, 2 Gy, and 4 Gy. To create an animal model of pancreatic cancer, the SW 1990 cells were surgically implanted into the mouse pancreas. At 10 d post-implantation, the 30 mice with pancreatic cancer underwent 125I seed implantation and were separated into three groups: 0 Gy, 2 Gy, and 4 Gy group. At 48 or 72 h after irradiation, apoptosis was detected by flow cytometry; changes in DNMTs mRNA and protein expression were assessed by real-time PCR and western blotting analysis, respectively. At 28 d after 125I seed implantation, in vivo apoptosis was evaluated with TUNEL staining, while DNMTs protein expression was detected with immunohistochemical staining. The tumor volume was measured 0 and 28 d after 125I seed implantation. Results 125I seed irradiation induced significant apoptosis, especially at 4 Gy. DNMT1 and DNMT3b mRNA and protein expression were substantially higher in the 2 Gy group than in the control group. Conversely, the 4 Gy cell group exhibited significantly decreased DNMT3b mRNA and protein expression relative to the control group. There were substantially more TUNEL positive in the 125I seed implantation treatment group than in the control group, especially at 4 Gy. The 4 Gy seed implantation group showed weaker staining for DNMT1 and DNMT3b protein relative to the control group. Consequently, 125I seed implantation inhibited cancer growth and reduced cancer volume. Conclusion 125I seed implantation kills pancreatic cancer cells, especially at 4 Gy. 125I-induced apoptosis and changes in DNMT1 and DNMT3b expression suggest potential mechanisms underlying effective brachytherapy.

Gong Yan-fang

2011-04-01

144

Monte Carlo investigation of influence of Titanium k X-rays on air-kerma strength and dose rate constant of 125I brachytherapy sources  

International Nuclear Information System (INIS)

Recently the number of 125I brachytherapy sources and its applications has dramatically increased in the treatment of the eye, brain, head and neck region and in permanent implant for early stage prostate cancer. The active material of all these sources is in the form of silver rod or sphere, coated with radioactive layer and encapsulated in titanium tube. The photoelectric interaction of 125I photons with titanium (Ti) encapsulation generates K-shell characteristic x-rays of energy ?5 keV. These x-rays are totally absorbed in tissue within 1 mm of the source (mean free path in water is only 0.23 mm) and thus do not contribute to the dose rate constant ?. NIST in 1999, proposed that these x-rays should be excluded while determining air-kerma strength Sk. In the present work we investigate the influence of the above-mentioned x-rays on the calculated values of Sk and ? for few commercial models of 125I sources. The geometry details of the investigated sources are significantly different from each other. Monte Carlo-based MCNP code with updated photon cross-section library is used for this purpose

145

125I and 125I-glucagon metabolism in rat liver  

International Nuclear Information System (INIS)

This report suggests that the time course and enzymatic nature of 125I-insulin degradation in vivo correlates with major subcellular locations of autoradiographic grains during the course of endocytosis. 125I-insulin and hormone fragments were detected in liver extracts using reverse-phase high performance liquid chromatography (RP-HPLC). 125I-insulin was rapidly degraded in vivo. Comparison with autoradiographic studies suggests insulin degradation begins before substantial lysosomal localization is observed. Studies using an isolated perfused rat liver system suggest that the plasmalemma does not mediate rapid insulin degradation as observed in vivo. The author, therefore, sought to identify 125I-insulin fragments which typified the activities of the most-implicated intracellular degradative systems: acidic lysosomal proteolysis, a microsomal reductive system such as glutathione-insulin transhydrogenase (GIT), and a cytosolic neutral proteolytic system such as insulin protease. Significant GIT activity was not observed in vivo nor in vitro with liver homogenates. Purified liver insulin protease degraded 125I-insulin in a fashion similar to that observed in vivo. Lysosomal activity was observed only after a lag of approximately 10 minutes. Complete degradation of 125I-glucagon in vivo occurred within 1 minute of hormone injection

146

Preparation of 125I labelled compound  

International Nuclear Information System (INIS)

Iodinated compounds with 131I, 125I and 123I have been widely used for biochemical function studies. In conjunction with SPECT, [123I] labelled proteins have various diagnostic and therapeutic applications in nuclear medicine. In this study, synthesis and quality control of [18F]radiofluorinated and radioiodinated of some proteins and peptides as well as their biological behaviors are considered to be investigated. (author)

147

Biodistribution properties of two 125I labeled novel neurotensin analogues  

International Nuclear Information System (INIS)

Two novel neurotensin analogues NT1(Arg-Lys-Pro-Tyr-TLe-Leu) and NT2 (Lys-Arg-Pro-Tyr-TLe-Leu) are labeled with 125I by Chloramine T method. Biodistribution studies of 125I-NT1 and 125I-NT2 are carried out in ICR mice and Balb/c nude mice bearing HT29 xenografts. The results indicate that 125I-NT1 and 125I-NT2 have similar biodistribution and specific tumor targeting properties. 125I-NT2 shows promising properties and is worth of further investigation. (authors)

148

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

International Nuclear Information System (INIS)

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

149

Impact of differences in ultrasound and computed tomography volumes on treatment planning of permanent prostate implants  

International Nuclear Information System (INIS)

Purpose: Both ultrasound (US) and computerized tomography (CT) images have been used in the planning of prostate interstitial therapy. Ultrasound images more clearly define the apex and capsule of the prostate, while CT images define seed positions for postimplant dosimetry. Proper registration of the US volume with the CT volume is critical to the assessment of dosimetry. We therefore compared US and CT prostate volumes to determine if differences were significant. Methods and Materials: Ten consecutive patients entered in an interstitial implant program were studied by pretreatment US. In addition, pretreatment CT scans were obtained and three physicians independently outlined the dimensions of the prostate on these images. The patients subsequently underwent placement of radioactive 125I or 103Pd. Postimplant CT images were obtained the next day and the postimplant prostate volumes were outlined by the same three physicians. Seven of 10 patients underwent late CT scans 9-14 months postimplant for comparison of preimplant and immediate postimplant CT studies. Results: There were differences between US and CT volumes. Although the physician-to-physician variation was significant, the trends were consistent, with US prostate volume typically smaller (47%) than the preimplant CT volume and markedly smaller (120%) than the postimplant CT volume. Prostate volumes derived from late CT images did not consistently return to preimplant levels. Conclusiotly return to preimplant levels. Conclusions: Significant differences in volume of the prostate structure were found between US and CT images. The data suggests that: (a) Implants planned on CT tend to overestimate the size of the prostate and may lead to unnecessary implantation of the urogenital diaphragm and penile urethra. (b) Registration of initial US and postimplant CT prostate volumes required for accurate dosimetry is difficult due to the increased volume of prostate secondary to trauma. (c) Further study to determine the optimal time for the postimplant CT is necessary

150

Electrophoretic purification of 125I-gliadin  

International Nuclear Information System (INIS)

A sensitive RIA technique is introduced for the estimation of gliadins in foodstuffs allowing the detection of less than 1 mg gliadin per kg of food. 125I-gliadin succinylated is used as a tracer after purification by electrophoresis in polyacrylamide gel. The method can be used for an effective control of gluten-free foods. False positive results cannot be excluded completely, since interfering factors are extracted together with the gliadins from the sample material. Vegetable lectins are discussed as the most probable interfering factors. (author)

151

Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction  

International Nuclear Information System (INIS)

Purpose: The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. Methods: A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (Fr: with resensitization, Fn: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as ?, ?, and relative biological effectiveness for different types of tumors were used for the calculation. Results: Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (Fr) and without (Fn) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of Fr/Fn were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of Fr/Fn were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of Fr/Fn were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of Fr was 1.07/1.11 (rounded to 1.1), and the averaged value of Fn was 1.75/1.18. Fr of 1.1 has been applied to gynecological cancer implants with expected acute reactions and outcomes as expected based on extensive experience with permanent implants. The calculation also gave the average Cs-131 dose of 126 Gy converted from the I-125 dose of 144 Gy for prostate implants. Conclusions: Inclusion of an allowance for resensitization led to significant dose corrections for Cs-131 permanent implants, and should be applied to prescription dose calculation. The adjustment of the Cs-131 prescription doses with resensitization correction for gynecological permanent implants was consistent with clinical experience and observations. However, the Cs-131 prescription doses converted from other implant doses can be further adjusted based on new experimental results, clinical observations, and clinical outcomes

152

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

International Nuclear Information System (INIS)

Purpose: To investigate methods of generating accurate patient-specific computational phantoms for the Monte Carlo calculation of lung brachytherapy patient dose distributions. Methods: Four metallic artifact mitigation methods are applied to six lung brachytherapy patient computed tomography (CT) images: simple threshold replacement (STR) identifies high CT values in the vicinity of the seeds and replaces them with estimated true values; fan beam virtual sinogram replaces artifact-affected values in a virtual sinogram and performs a filtered back-projection to generate a corrected image; 3D median filter replaces voxel values that differ from the median value in a region of interest surrounding the voxel and then applies a second filter to reduce noise; and a combination of fan beam virtual sinogram and STR. Computational phantoms are generated from artifact-corrected and uncorrected images using several tissue assignment schemes: both lung-contour constrained and unconstrained global schemes are considered. Voxel mass densities are assigned based on voxel CT number or using the nominal tissue mass densities. Dose distributions are calculated using the EGSnrc user-code BrachyDose for125I, 103Pd, and 131Cs seeds and are compared directly as well as through dose volume histograms and dose metrics for target volumes surrounding surgical sutures. Results: Metallic artifact mitigation techniques vary in ability to reduce artifacts while preserving tissue detail. Notably, images corrected with the fan beam virtual sinogram have reduced artifacts but residual artifacts near sources remain requiring additional use of STR; the 3D median filter removes artifacts but simultaneously removes detail in lung and bone. Doses vary considerably between computational phantoms with the largest differences arising from artifact-affected voxels assigned to bone in the vicinity of the seeds. Consequently, when metallic artifact reduction and constrained tissue assignment within lung contours are employed in generated phantoms, this erroneous assignment is reduced, generally resulting in higher doses. Lung-constrained tissue assignment also results in increased doses in regions of interest due to a reduction in the erroneous assignment of adipose to voxels within lung contours. Differences in dose metrics calculated for different computational phantoms are sensitive to radionuclide photon spectra with the largest differences for103Pd seeds and smallest but still considerable differences for 131Cs seeds. Conclusions: Despite producing differences in CT images, dose metrics calculated using the STR, fan beam + STR, and 3D median filter techniques produce similar dose metrics. Results suggest that the accuracy of dose distributions for permanent implant lung brachytherapy is improved by applying lung-constrained tissue assignment schemes to metallic artifact corrected images

153

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-01-15

154

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

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

155

Impact of ultrasound and computed tomography prostate volume registration on evaluation of permanent prostate implants  

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Purpose: Ultrasound (US)-guided permanent prostate implants typically use US prostate volumes to plan the implant procedure and CT prostate volumes for 3D dosimetric evaluation of the implant. Such a protocol requires that CT and US prostate volumes be registered. We have studied the impact of prostate volume registration on postimplant dosimetry for patients with low-grade prostate cancer treated with combined US and fluoroscopic-guided permanent implants. Methods and Materials: A US image set was obtained with the patient in the lithotomy position to delineate the prostate volume that was subsequently used for treatment planning. Each plan was customized and optimized to ensure complete coverage of the US prostate volume. After implant, a CT scan was obtained for postimplant dosimetry with the patient lying supine. Sources were localized on CT by interactively creating orthogonal images of small cubes, whose dimensions were slightly larger than the source, to assure unique identification of each seed. Ultrasound and CT 3D surfaces were registered using either (a) the rectal surface and base of the prostate, or (b) the Foley balloon and urethra as the alignment reference. A dose distribution was assigned to the US prostate volume based on the CT source distribution, and the dose-volume histogram (DVH) was calculated. Result: Prostate volumes drawn from US images differ from those drawn from CT images with the CT volumes being typically larger than the US volumes. Ure typically larger than the US volumes. Urethral registration of the prostate volume based on aligning the prostatic urethra generates a dose distribution that best follows the preimplant plan and is geometrically the preferable choice for dosimetry. Conclusion: The dose distribution and the DVH for the US prostate is sensitive to the mode of registration limiting the ability to determine if acceptable dose coverage has been achieved

156

Brachytherapy dosimetry of 125I and 103Pd sources using an updated cross section library for the MCNP Monte Carlo transport code  

International Nuclear Information System (INIS)

Permanent implantation of low energy (20-40 keV) photon emitting radioactive seeds to treat prostate cancer is an important treatment option for patients. In order to produce accurate implant brachytherapy treatment plans, the dosimetry of a single source must be well characterized. Monte Carlo based transport calculations can be used for source characterization, but must have up to date cross section libraries to produce accurate dosimetry results. This work benchmarks the MCNP code and its photon cross section library for low energy photon brachytherapy applications. In particular, we calculate the emitted photon spectrum, air kerma, depth dose in water, and radial dose function for both 125I and 103Pd based seeds and compare to other published results. Our results show that MCNP's cross section library differs from recent data primarily in the photoelectric cross section for low energies and low atomic number materials. In water, differences as large as 10% in the photoelectric cross section and 6% in the total cross section occur at 125I and 103Pd photon energies. This leads to differences in the dose rate constant of 3% and 5%, and differences as large as 18% and 20% in the radial dose function for the 125I and 103Pd based seeds, respectively. Using a partially updated photon library, calculations of the dose rate constant and radial dose function agree with other published results. Further, the ush other published results. Further, the use of the updated photon library allows us to verify air kerma and depth dose in water calculations performed using MCNP's perturbation feature to simulate updated cross sections. We conclude that in order to most effectively use MCNP for low energy photon brachytherapy applications, we must update its cross section library. Following this update, the MCNP code system will be a very effective tool for low energy photon brachytherapy dosimetry applications

157

125I Measurements for Occupational Exposure Assessment  

International Nuclear Information System (INIS)

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

158

Decline of dose coverage between intraoperative planning and post implant dosimetry for I-125 permanent prostate brachytherapy: Comparison between loose and stranded seed implants  

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Background and purpose: In permanent prostate brachytherapy the dose distributions 4 weeks post implant differ from the intraoperative dose distributions. The purpose of this study is to compare intraoperative planning and post implant dosimetry for loose and stranded seed implants. Materials and methods: This study investigates prostate dose coverage in 389 patients with stage T1 or T2 prostate cancer treated in the years 2005, 2006 and 2007. The patients received either a loose seed or a stranded seed implant. All patients had US-based intraoperative planning and CT/MRI-based post implant dosimetry after 4 weeks. Results: Intraoperative and post implant D90 values amounted 183 ± 13 Gy (mean ± standard deviation) and 161 ± 30 Gy, respectively. Decline of D90 values (mean and 95% confidence interval) between intraoperative planning and post implant dosimetry for RAPID strand (n = 67), Intersource strand (n = 136) and loose selectSeeds (n = 186) implants amounted to -40 (-45 to -34) Gy, -25 (-28 to -21) Gy and -15 (-18 to -21) Gy, respectively. Conclusions: The patients treated in the period 2005-2007 with stranded or loose seed implants had on average adequate D90 values of 161 ± 30 Gy. Post implant D90 values were 22 ± 27 Gy lower compared to intraoperative planning. Decline of dose coverage between intraoperative planning and post implant dosimetry was significantly larger for the stranded seed implants.stranded seed implants.

159

Calculation of the dose equivalent around a patient receiving treatment with {sup 125}I seeds  

Energy Technology Data Exchange (ETDEWEB)

Interstitial brachytherapy with {sup 125}I seeds for treatment of prostate cancer is being carried out successfully in Europe and U.S.A. However, its widespread use in Japan has been limited by regulations governing the exposure of individuals. Basic radiation protection data are required to promote the use of {sup 125}I seed sources. In preparation for implementing this new modality, we carried out a series of measurements to determine the 1 cm dose equivalent in a caregiver located 1 m from the implanted patient. These measurements were compared with published recommendations of acceptable doses, and may be used to develop guidelines for discharge of the patient. The 1 cm dose equivalent was measured 1 m from the source under clinically relevant conditions by placing 50 {sup 125}I seeds (437.5 MBq) into the portion of a humanoid phantom that corresponds to the prostate. The 1 cm dose equivalent was 0.0014 {mu}Sv{center_dot}m{sup 2}{center_dot}MBq{sup -1}{center_dot}h{sup -1} 1 m from the surface of the phantom. The calculated dose to a caregiver based on this figure is well below the 5 mSv value recommended by the IAEA as a constraint dose for the caregiver. These measurements and calculations suggest that {sup 125}I seed implants of outpatients should be permissible. (author)

Sasaki, Toru; Dokiya, Takushi; Toya, Kazuhito; Kawase, Takatsugu [National Tokyo Medical Center Hospital (Japan); Hashimoto, Mitsuyasu

2001-03-01

160

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

International Nuclear Information System (INIS)

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

161

Advances in the therapy of pancreatic carcinoma with 125I seeds  

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Radioactive seeds have been used to treat pancreatic carcinoma in the early twenty centries. Advances in the therapy of pancreatic carcinoma with radioactive seeds is slow because of the limitations of radiobiology and radiophysics, unsoundness of implantation technique and implantation plan system. As the radioactive seeds 125I have been used since the late 1960s and radiobiology and radiophysics of radionuclide has been studied profoundly, fast development of three-dimensional tratment plan system, useness of ultrasonically guided percutaneous implantation therapy for pancreatic carcinoma with radioactive seeds rise again. (authors)

162

Exclusive curietherapy by permanent iodine-125 implants: selection of patients and results after eight years  

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The authors report a retrospective study which assesses the results obtained over eight years and the toxicity of an exclusive curietherapy by permanent iodine-125 implants performed at the Nancy centre of struggle against cancer. More than five hundred patients have been treated between December 1999 and December 2007, a first group comprising patients suffering from a low risk cancer and a second group suffering from a medium risk cancer. The authors discuss the survival rates, the existence of side effects, and rectal toxicity results. Short communication

163

Absorption of 125I and 3H in aquatic plants  

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The absorption of 125I and 3H in four aquatic plants was studied by solution cultivation. The results showed that arrowhead (Sagittaria pygmaea Miq.) was the fastest in absorbing 125I among the four tested aquatic plants and its concentration factor for 125I was the highest (85.79). The alligator alternanthera (Alternanthera philoxeroides) was the slowest in absorbing 125I and its concentration factor was the lowest. However, the absorption of 3H in alligator alternanthera was the fastest among the four aquatic plants. After being absorbed by aquatic plants, the 125I could be transferred to the shoot. In arrowhead, about 75% of 125I remained in the root, 25% being transferred to the shoot

164

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

International Nuclear Information System (INIS)

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 125I and 103Pd 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 125I and 103Pd 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 exisen the prescription dose was based on existing clinical experience of using 125I seeds alone, mixing 103Pd seeds with 125I seeds would increase the cell kill. On the other hand, if the prescription dose were based on existing clinical experience of using 103Pd seeds alone, mixing 125I seeds with 103Pd 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 125I seeds. For fast-growing tumors, these 'cold' spots can become significant. Conclusions: Total dose alone is no longer sufficient for a complete characterization of a permanent seed implant containing a mixture of radionuclides with different half-lives due to the presence of cell proliferation and sublethal damage repair in the protracted dose delivery. BED provides a tool for evaluating the radiobiologic effects of mixing different type of radionuclides in the same implant. When radionuclides of different half-lives are mixed in a permanent implant, using the dose prescription established from existing clinical experience of implants with the longer half-life radionuclide would help to avoid radiobiologic 'cold' spots

165

[Experience with 125I brachytherapy as a radical treatment for prostate cancer at the Russian X-ray Radiology Research Center].  

Science.gov (United States)

Prostate cancer is one of the most common malignancies among males. 125I brachytherapy is a current, effective, comparatively safe, and easy-to-reproduce treatment. The Russian X-ray Radiology Research Center has implanted 125I microsources in patients with localized and locally advanced prostate cancer since 2003; 689 125I implantations were performed in the past year. Tumor-specific survival after brachytherapy did not differ greatly from that following radical prostatectomy. Thus, brachytherapy is a current high-tech treatment for prostate cancer. This therapy shows fewer adverse postradiation effects than radiation teletherapy. PMID:21598469

Kaprin, A D; Milenin, K N; Ivanov, S A; Tsybul'ski?, A D; Gerasimov, A A

2011-01-01

166

The labelling of recombinant L-asparaginase with 125I  

International Nuclear Information System (INIS)

Recombinant L-asparaginase is labelled with 125I by the method of Chloramine-T. After purification using Sephadex G-25, 125I-recombinant L-asparaginase is separated by RP-HPLC and determined by ?-counter. The radiochemical purity of 125I-recombinant L-asparaginase is more than 95%. 125I-recombinant L-asparaginase is analysed by double immunological diffusion and is demonstrated. The results show that the biological activity is the same as recombinant L-asparaginase

167

Radiolabeling of paclitaxel with 125I  

International Nuclear Information System (INIS)

The modified Ch-T labeling method has been investigated. Firstly, the paclitaxel was reacted with non-radioactive Nal. Then the mixture was radiolabeled with 125I by modified Ch-T method. The radiolabeling yield was analyzed by thin paper chromatography and HPLC. After purified, the radiochemical purity and stability of the radiolabeled compounds were tested in vitro under different conditions, such as temperature or solvent and the final labeled compound was identified by infrared spectra. The radiolabeled yield of the com- pound produced by the modified Ch-T method was compared with those produced by the nitric acid oxidization method and the common Ch-T method. The radiolabeling yield of the labeled compound produced by the modified Ch-T method was about 63.1% ±5.7% and the radiochemieal purity was about 96.3% ± 1.3% . After 24 hours stored in NS or alcohol sys- tem at 4 degree C, the radioehemical purity of the product was above 95%, and 90% after 120 h. The labeled product was also stable in serum, after 24 h stored at 4 degree C and 37 degree C, the radiochemical purities were 92.3%±0.4% and 89.5%±0.6% respectively. The modified Ch-T method was simple and convenient. The radiolabeling yield was high and the labeled compound was stable. It was qualified for the isotopic tracing experiment in vivo. (authors)

168

Decontamination of 125I in medical laboratory  

International Nuclear Information System (INIS)

A radiological laboratory for diagnoses was contaminated by 125I. A large-scale survey of gammaradiation has been made in different locations of the floors and walls of the lab to determine the contaminated area and its activity. The activity level before decontamination for the wall and floor was 1400 and 2000 Bq/cm2 respectively. Decontamination was carried out by using ethyl alcohol, potassium permanganate, ethylene diamine tetracetic acid and tissue papers. Decontamination factor has been calculated and it was 175 and 200 for the wall and floor respectively. D and D computer code has been used to calculate Total Effective Dose Equivalent (TEDE). TEDE from the wall and floor before decontamination were 3.05 and 4.35 (mSv/yr) while after decontamination were 18 and 23 ?Sv/yr respectively. These results are lower than the Egyptian and the international regulations (10 mSv/y for the public ) according to International Atomic Energy agency, IAEA, Safety Series, SS, no. 115 (1994). (author)

169

Case report on extensive left atrial myxoma removal with permanent pacemaker implantation  

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Full Text Available Aim: To represent a case report of extensive left atrial myxoma removal with permanent pacemaker implantation. Methods: A 56-year old female patient admitted to the Bakulev Center of Cardiovascular Surgery with cardiac evaluation. She noted progressive chest pain associated with dyspnea and fatigue. After physical examination, transthoracic echocardiography and other methods of evolution confirmed the diagnosis: Tumor of the left atrium. Left atrial dilatation. Left ventricle hypertrophy. Arterial hypertension 2 stage of high risk. Circulatory failure 2 stage (by Strazhesko-Vasilenko, functional class II by NYHA. The huge tumor was successfully excised with closure of atrial septal defect by patch. Results: Transthoracic echocardiography in postoperative period showed a normal left and right ventricular function and no residual shunts. The presence of conduction abnormalities in early postoperative period predicted the need for permanent pacemaker implantation. Conclusions: It must be noted rare occurrence of a huge tumor (myxoma filling left atrium. Large left atrial tumor is approached by biatrial incision with further excision. It is believed that the case can be beneficial in huge cardiac tumors management. Early detection and surgical treatment of heart tumors can reduce the risk of heart failure, systemic embolization, syncope and sudden cardiac death.

Bokeria L.A.

2013-06-01

170

Sinus node dysfunction requiring permanent pacemaker implantation in a young adult with klinefelter syndrome.  

Science.gov (United States)

Background Klinefelter syndrome is the most common genetic cause of male infertility and affects approximately 1 in 500 live births. Although accompanying cardiac disorder is not a specific feature of Klinefelter syndrome, rarely associated anomalies such as mitral valve prolapse, atrial septal defect, ventricular septal defect, tetralogy of Fallot, patent ductus arteriosus, and hypertrophic obstructive cardiomyopathy have been reported. A clear association between Klinefelter syndrome and arrhythmic disorders has not yet been demonstrated. Case Report We report a case of a sinus node dysfunction that required permanent pacemaker implantation in a young adult with Klinefelter syndrome. The patient was consulted to cardiology clinic due to bradycardia. On physical examination, no cardiac abnormality was detected except for bradycardia. Holter results showed sinus arrhythmia with a minimum heart rate of 33 bpm and maximum of 154 Bpm. There were 3612 ventricular premature beats, 30 ventricular pairs, 804 supraventricular premature beats, 7 supraventricular pairs, and 4 supraventricular runs, the longest of which was 5 beats. The patient had defined dizziness and nausea during Holter monitoring. Electrophysiological study (EPS) was planned because existing findings indicated risk of cardiac syncope. Findings of EPS were interpreted as sinus node dysfunction. A permanent pacemaker implantation was performed and the patient has been free of symptoms since. Conclusions This concomitance should be kept in mind when examining patients with Klinefelter syndrome with bradycardia and/or syncope. It is easily mistaken for epilepsy, which is a commonly encountered abnormality in Klinefelter syndrome. PMID:25744562

Karagöz, Ahmet; Dikba?, O?uz; Teker, Erhan; Vural, Asl?; Günayd?n, Zeki Yüksel; Bekta?, Osman

2015-01-01

171

Installation of radiochromatography for testosterone-3-carboxymethyloxime-tyramine-125 I (T-3-CMO-Ty-125 I)  

International Nuclear Information System (INIS)

The paper presents a device for radiochromatography of testosterone-3-carboxymethyloxime-tyramine-125 I (T-3-CMO-Ty-125 I), a reagent used as marker in radioimmunoassays (RIA) of steroid hormones. One of the most adequate technique of analyzing the steroid hormones is RIA (radioimmunoassay) due to its sensitivity and specificity. This technique requires advanced purification of the sample. In the view of developing a sensitive RIA technique for assaying the steroid hormones an installation for radiochromatography of testosterone-3-carboxymethyloxime-tyramine-125 I (T-3-CMO-Ty-125 I) is necessary. (authors)

172

Sinus Node Dysfunction Requiring Permanent Pacemaker Implantation in a Young Adult with Klinefelter Syndrome  

Science.gov (United States)

Patient: Male, 22 Final Diagnosis: Sinus node dysfunction Symptoms: Bradycardia • lassitude Medication: — Clinical Procedure: Pacemaker implantation Specialty: Cardiology Objective: Unusual clinical course Background: Klinefelter syndrome is the most common genetic cause of male infertility and affects approximately 1 in 500 live births. Although accompanying cardiac disorder is not a specific feature of Klinefelter syndrome, rarely associated anomalies such as mitral valve prolapse, atrial septal defect, ventricular septal defect, tetralogy of Fallot, patent ductus arteriosus, and hypertrophic obstructive cardiomyopathy have been reported. A clear association between Klinefelter syndrome and arrhythmic disorders has not yet been demonstrated. Case Report: We report a case of a sinus node dysfunction that required permanent pacemaker implantation in a young adult with Klinefelter syndrome. The patient was consulted to cardiology clinic due to bradycardia. On physical examination, no cardiac abnormality was detected except for bradycardia. Holter results showed sinus arrhythmia with a minimum heart rate of 33 bpm and maximum of 154 Bpm. There were 3612 ventricular premature beats, 30 ventricular pairs, 804 supraventricular premature beats, 7 supraventricular pairs, and 4 supraventricular runs, the longest of which was 5 beats. The patient had defined dizziness and nausea during Holter monitoring. Electrophysiological study (EPS) was planned because existing findings indicated risk of cardiac syncope. Findings of EPS were interpreted as sinus node dysfunction. A permanent pacemaker implantation was performed and the patient has been free of symptoms since. Conclusions: This concomitance should be kept in mind when examining patients with Klinefelter syndrome with bradycardia and/or syncope. It is easily mistaken for epilepsy, which is a commonly encountered abnormality in Klinefelter syndrome. PMID:25744562

Karagöz, Ahmet; Dikba?, O?uz; Teker, Erhan; Vural, Asl?; Günayd?n, Zeki Yüksel; Bekta?, Osman

2015-01-01

173

Immunoreactivity of 125I-papain labelled by different methods  

International Nuclear Information System (INIS)

Three different methods of papain iodination (with chloramine-T, lactoperoxidase and conjugation with Bolton-Hunter reagent) have been compared. The highest yield of 125I-papain could be obtained using lactoperoxidase which enabled to achieve the highest immunoreactivity. 125I-papain, labelled this way, is suitable for the radioimmunoassay of papain. (author)

174

Quality asurance of iodinated (125 I) human fibrinogen  

International Nuclear Information System (INIS)

The radiopharmaceutical iodinated (125 I) human fibrinogen is currently used for the detection of deep vein thrombosis in the legs, a fairly common post-surgical complication. A comprehensive quality assurance programme for (125 I) - human fibrinogen has been determined for routine use at the Australian Radiation Laboratory, with adaptions necessary for hospital quality control testing

175

A radioimmunoassay for plasma androstenedione using 125I tracer  

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A radioimmunoassay for plasma androst-4-en-3,17-dione is described using ether extracts of plasma and 125I radioligand. The reagent is easily prepared by an established radiochemical method from androst-4-en-3,17-dione-6?-(carboxymethyl) thioether and 125I-histamine. (Auth.)

176

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

International Nuclear Information System (INIS)

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 T1-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 ± 101% (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. Conclusions: Registration of the reconstructed seed distribution and the MR images enabled evaluation of target coverage, which amounted to 60 ± 10%. The discrepancy between prescribed dose and realized dose was caused by underestimation of the preimplant prostate volume due to the ellipsoidal approximation, postimplant prostate swelling at the time of evaluation, and inaccuracies in seed placement

177

Treatment of prostate adenocarcinoma permanent implants with I 125: first experience in Uruguay  

International Nuclear Information System (INIS)

Full text: Objective: To report on the treatment done, toxicity and development of a group of adenocarcinoma patients with localized prostate brachytherapy implants permanent I125. Material and Methods. 37 patients were treated in the period 2001 to 2004 at the Military Hospital Central by this treatment modality. All of them were performed before implantation planning, which consisted of the volumetric calculation and calculation prostate dosimetry that included transrectal prostate ultrasound 3-5 weeks before the procedure. all patients had pathological confirmation of the lesion showed PSA values less than 11 ng / ml and Gleason score less than 7. 70% of patients received neo-adjuvant hormone therapy. In 5 patients an interactive planning system was performed computerized dosimetry, using sequential ultrasound imaging planes, allowed the dosimetric analysis before terminate the procedure and make necessary adjustments if the dose distribution did not conform. This additional dosimetric study we have not been described by other authors. Prescribed in the first 10 patients was dose 144 Gy and 160 Gy in subsequent. All patients underwent post implant CT waffle grid after 15 days of the procedure. analyzed the dose volume histogram (HDV) and D90 values??. Clinical follow-up was performed and PSA biochemical .. Preliminary Results: 33 patients were in local control without biochemical failure. Currently 4 patients presented biochemical recurrence with PSA values ??between 4 and 6 ng / ml. In neither disease was found at a distance and then raises confirmation tumor biopsy active presence will undergo surgical treatment protocols localized prostate cancer. HDV values ??D90 and are consistent with the informed by the international literature will be presented. No patient required hospitalization prolonged (greater than 24 hours) or use of higher analgesics. 2 patients had acute urinary retention (G II complication) between the tenth and twentieth day, the rest of the patients had minor complications (G I), hematuria spontaneously fell to fourth day of treatment (1), mild perineal hematoma (1). Most patients dysuria presented from the first week I was treated with alpha-blockers.Conclusions: Prostate brachytherapy with permanent implants is a procedure I125 well tolerated, minimally invasive, Given the short follow-up time of regard them as preliminary results in this selected patient population

178

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

International Nuclear Information System (INIS)

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 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

179

Effect of 125I interstitial radiotherapy on blood-brain barrier function in normal canine brain  

International Nuclear Information System (INIS)

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

180

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

International Nuclear Information System (INIS)

Objective: To discuss the curative effect and safety of the implantation of self-expandable medical memorial metallic stent with 125I seeds for the treatment of advanced esophageal carcinomas. Methods: Implantation of self-expandable medical memorial metallic stent with 125I 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 125I 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 125I seeds is safe, effective and simple. This treatment can markedly improve the symptom of dysphagia and significantly prolong the patient's survival time. (authors)

181

Erectile function one year after permanent I-125 seed implantation for prostate cancer  

International Nuclear Information System (INIS)

We assess erectile function after prostate brachytherapy. A total of 217 patients with permanent I-125 seed implantation for prostate cancer had erectile function assessed before and after treatment. Erectile function was assessed using the scoring system of 0; complete inability, 1; insufficient for intercourse, 2; suboptimal and 3; normal erectile function. Ages had a significant impact on pretreatment function. In 127 patients (56%) who were potent with a score 2 or greater before treatment the preservation of potency, with a score 2 or greater, was 74% for patients treated with radiotherapy alone and 67% for patient treated with neoadjuvant hormonal treatment. The potency rate gradually recovered within one year after hormonal treatment. (author)

182

Systemic administration of kainic acid induces selective time dependent decrease in [125I]insulin-like growth factor I, [125I]insulin-like growth factor II and [125I]insulin receptor binding sites in adult rat hippocampal formation  

International Nuclear Information System (INIS)

Administration of kainic acid evokes acute seizure in hippocampal pathways that results in a complex sequence of functional and structural alterations resembling human temporal lobe epilepsy. The structural alterations induced by kainic acid include selective loss of neurones in CA1-CA3 subfields and the hilar region of the dentate gyrus followed by sprouting and permanent reorganization of the synaptic connections of the mossy fibre pathways. Although the neuronal degeneration and process of reactive synaptogenesis have been extensively studied, at present little is known about means to prevent pathological conditions leading to kainate-induced cell death. In the present study, to address the role of insulin-like growth factors I and II, and insulin in neuronal survival as well as synaptic reorganization following kainate-induced seizure, the time course alterations of the corresponding receptors were evaluated. Additionally, using histological preparations, the temporal profile of neuronal degeneration and hypertrophy of resident astroglial cells were also studied. [125I]Insulin-like growth factor I binding was found to be decreased transiently in almost all regions of the hippocampal formation at 12 h following treatment with kainic acid. The dentate hilar region however, exhibited protracted decreases in [125I]insulin-like growth factor I receptor sites throughout (i.e. 30 days) the study. [125I]Insulin-like growth factor II receptsup>I]Insulin-like growth factor II receptor binding sites in the hippocampal formation were found to be differentially altered following systemic administration of kainic acid. A significant decrease in [125I]insulin-like growth factor II receptor sites was observed in CA1 subfield and the pyramidal cell layer of the Ammon's horn at all time points studied whereas the hilar region and the stratum radiatum did not exhibit alteration at any time. A kainate-induced decrease in [125I]insulin receptor binding was noted at all time points in the molecular layer of the dentate gyrus whereas binding in CA1-CA3 subfields and discrete layers of the Ammon's horn was found to be affected only after 12 h of treatment. These results, when analysed with reference to the observed histological changes and established neurotrophic/protective roles of insulin-like growth factors and insulin, suggest possible involvement of these growth factors in the cascade of neurotrophic events that is associated with the reorganization of the hippocampal formation observed following kainate-induced seizures. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

183

Permanent implantation of peripheral nerve stimulator for combat injury-related ilioinguinal neuralgia.  

Science.gov (United States)

A peripheral nerve stimulator (PNS) can be an alternative for long-term pain relief refractory to conventional therapeutic modalities. We present a case of chronic incapacitating ilioinguinal neuralgia, which was successfully managed with permanent implantation of a peripheral nerve stimulator. A 26-year-old active duty African American man was referred to the University Pain Clinic with left ilioinguinal neuralgia due to shrapnel injury during his military service 6 years prior to his visit. Most of the shrapnel were surgically removed, but the patient subsequently developed left lower abdominal pain. Multiple surgeries, including inguinal herniorrhaphy, varicocelectomy, and orchiectomy, failed to provide satisfactory relief of his neuralgia. Other therapies tried resulting in limited outcomes were multiple ilioinguinal nerve blocks and cryoanalgesia. A trial of PNS was successful and the implantation of permanent leads was carried out. At his 3-month visit, the patient reported to have minimal pain, was tapered off oral analgesics, was able to return to work, and had resumed his normal daily activities. Recent technological advances in programming software and surgical techniques have led to renewed interest in PNS for the treatment of chronic refractory peripheral nerve injury. Despite our limited understanding of its exact mechanism of action, it can be considered as a therapeutic potential for a few carefully selected, intractable cases. Its minimally invasive and reversible features make PNS a favorable option for these patients. The stringent and rigorous screening procedures for suitable candidacy, documentation of previously failed treatments, psychiatric evaluation, and 3-5 days of preplacement trial, improve the success rate. PMID:24284860

Banh, Diem Phuc T; Moujan, Pablo M; Haque, Quazi; Han, Tae-Hyung

2013-01-01

184

Recommendations of the American Association of Physicists in Medicine regarding the Impact of Implementing the 2004 Task Group 43 Report on Dose Specification for 103Pd and 125I Interstitial Brachytherapy  

International Nuclear Information System (INIS)

In March 2004, the recommendations of the American Association of Physicists in Medicine (AAPM) on the interstitial brachytherapy dosimetry using 125I and 103Pd were reported in Medical Physics [TG-43 Update: Rivard et al., 31, 633-674 (2004)]. These recommendations include some minor changes in the dose-calculation formalism and a major update of the dosimetry parameters for eight widely used interstitial brachytherapy sources. A full implementation of these recommendations could result in unintended changes in delivered dose without corresponding revisions in the prescribed dose. Because most published clinical experience with permanent brachytherapy is based upon two widely used source models, the 125I Model 6711 and 103Pd Model 200 sources, in this report we present an analysis of the dosimetric impact of the 2004 TG-43 dosimetry parameters on the history of dose delivery for these two source models. Our analysis indicates that the currently recommended prescribed dose of 125 Gy for Model 200 103Pd implants planned using previously recommended dosimetry parameters [AAPM 103Pd dose prescription: Williamson et al., Med. Phys. 27, 634-642 (2000)] results in a delivered dose of 120 Gy according to dose calculations based on the 2004 TG-43 update. Further, delivered doses prior to October 1997 varied from 113 to 119 Gy for a prescribed dose of 115 Gy compared to 124 Gy estimated by the AAPM 2000 report. 124 Gy estimated by the AAPM 2000 report. For 125I implants using Model 6711 seeds, there are no significant changes (less than 2%). Practicing physicians should take these results into account when selecting the clinically appropriate prescribed dose for 103Pd interstitial implant patients following implementation of the 2004 TG-43 update dose-calculation recommendations. The AAPM recommends that the radiation oncology community review this report and consider whether the currently recommended dose level (125 Gy) needs to be revised

185

Recommendations of the American Association of Physicists in Medicine regarding the impact of implementing the 2004 task group 43 report on dose specification for 103Pd and 125I interstitial brachytherapy.  

Science.gov (United States)

In March 2004, the recommendations of the American Association of Physicists in Medicine (AAPM) on the interstitial brachytherapy dosimetry using 125I and 103Pd were reported in Medical Physics [TG-43 Update: Rivard et al., 31, 633-674 (2004)]. These recommendations include some minor changes in the dose-calculation formalism and a major update of the dosimetry parameters for eight widely used interstitial brachytherapy sources. A full implementation of these recommendations could result in unintended changes in delivered dose without corresponding revisions in the prescribed dose. Because most published clinical experience with permanent brachytherapy is based upon two widely used source models, the 125I Model 6711 and 103Pd Model 200 sources, in this report we present an analysis of the dosimetric impact of the 2004 TG-43 dosimetry parameters on the history of dose delivery for these two source models. Our analysis indicates that the currently recommended prescribed dose of 125 Gy for Model 200 103Pd implants planned using previously recommended dosimetry parameters [AAPM 103Pd dose prescription: Williamson et al., Med. Phys. 27, 634-642 (2000)] results in a delivered dose of 120 Gy according to dose calculations based on the 2004 TG-43 update. Further, delivered doses prior to October 1997 varied from 113 to 119 Gy for a prescribed dose of 115 Gy compared to 124 Gy estimated by the AAPM 2000 report. For 125I implants using Model 6711 seeds, there are no significant changes (less than 2%). Practicing physicians should take these results into account when selecting the clinically appropriate prescribed dose for 103Pd interstitial implant patients following implementation of the 2004 TG-43 update dose-calculation recommendations. The AAPM recommends that the radiation oncology community review this report and consider whether the currently recommended dose level (125 Gy) needs to be revised. PMID:15984693

Williamson, Jeffrey F; Butler, Wayne; Dewerd, Larry A; Huq, M Saiful; Ibbott, Geoffrey S; Mitch, Michael G; Nath, Ravinder; Rivard, Mark J; Todor, Dorin

2005-05-01

186

Antithrombogenicity of the Gyro permanently implantable pump with the RPM dynamic suspension system for the impeller.  

Science.gov (United States)

In 1995, a group at Baylor College of Medicine started to develop the NEDO biventricular assist device (BVAD) using two Gyro permanently implantable (PI) centrifugal pumps. This pump consists of a sealless pump housing and an impeller supported with a double pivot bearing. In May 2001, an RPM dynamic suspension system (RPM-DS) for the impeller was developed to improve durability and antithrombogenicity without a complex magnetic suspension system. From March 2000 to March 2002, eight BVAD bovine experimental studies were performed for more than 1 month. Two pumps were implanted in two cases without the RPM-DS (group A) and in six cases with the RPM-DS (group B). In group A, the survival period was 45 and 50 days. The primary reason for termination was an increase in the requiring power, which was related to deposition of white thrombus on the bottom bearing. In group B, the survival period was 37, 48, 51, 60, 80, and 90 days. The reasons for termination were not related to thrombus formation. No thrombus was observed in the pumps except for one right pump. In that experiment, the thrombus formation may have occurred when that pump had a low flow rate at a level of 1 L/min for 6 hr. These studies demonstrate the apparent antithrombogenic effect of RPM-DS. The NEDO BVAD is ready to move into a 3-month preclinical system evaluation. PMID:14616527

Ichikawa, Seiji; Nonaka, Kenji; Motomura, Tadashi; Ishitoya, Hiroshi; Watanabe, Kuniyoshi; Ashizawa, Satoshi; Shinohara, Toshiyuki; Sumikura, Hirohito; Ichihashi, Fumiyuki; Oestmann, Daniel; Nosé, Yukihiko

2003-10-01

187

Preparation and evaluation of serotonin labelled with 125I  

International Nuclear Information System (INIS)

Radiolabelled serotonin is an important tool for studying serotonin receptors and estimating serotonin levels in plants and animals. In this paper we report the synthesis of serotonin - 125I. Tyrosine Methyl Ester (TME) was first labelled with 125I using chloramine-T method. 125I-TME was then conjugated with serotonin using carbodimide. The labelled conjugate was purified using gel filtration. Yield and radiochemical purity were estimated using electrophoresis and ITLC in different solvent systems. The binding of the purified tracer to serotonin receptors and serotonin antibodies was studied. (author)

188

Quality control of 125I-brachytherapy seeds  

International Nuclear Information System (INIS)

An indigenous technology for the production of 125I brachytherapy sources has been developed for the management of intraocular cancer. This indigenous method of producing 125I seeds represents a new paradigm, and a thorough quality evaluation of the seeds in accordance with Atomic Energy Regulatory Board (AERB) of India was carried to ensure their safety during therapy. In this current work, we describe an overview of our experience, the efforts made in establishing enviable quality analysis of 125I seeds to ensure their safety in episcleral plaque brachytherapy. (author)

189

Factors influencing risk of acute urinary retention after TRUS-guided permanent prostate seed implantation  

International Nuclear Information System (INIS)

Purpose: To look for factors predictive of acute urinary retention (AUR) after permanent seed prostate brachytherapy. Methods and Materials: From March 1999 to February 2001, 150 permanent seed prostate implants were performed at Princess Margaret Hospital (Stage T1c, n = 113; T2a, n = 37; mean prostate-specific antigen level 5.9 ng/mL, prescription dose 145 Gy per Task Group No. 43). ?-Blockers were used routinely after implantation. Dosimetry was based on the 1-month postimplant CT scan. The International Prostate Symptom Score (IPSS) and catheterization were recorded at 1 month and 3 months and then every 3 months. The following variables were examined: age, baseline IPSS, prior androgen ablation, prostate transrectal ultrasound volume, number of seeds, D90, V100, V200, and urethral dose. Results: Twenty patients (13%) experienced AUR. No difference was seen in the mean D90 (149 Gy vs. 152 Gy, p=0.6), V100 (90% vs. 91%, p=0.6), V200 (23% vs. 25% p=0.4), IPSS (6.4 vs. 5.9, p=0.8), or maximal urethral dose (204 Gy vs. 210 Gy, p=0.5). The prostate volume was significantly larger in men with AUR (39.8 cm3 vs. 34.3 cm3, p=0.003), and the mean number of seeds was higher (112 vs. 103, p=0.006). Of the 20 patients experiencing AUR, 11 (55%) had received prior antiandrogen therapy to downsize their prostates vs. 35 (27%) of the 130 who did not have AUR (p=0.02). Multivariate analysis shve AUR (p=0.02). Multivariate analysis showed prostate volume and prior hormone use to be independent predictors of AUR. Conclusions: Implant quality as determined by D90, V100, V200, and urethral dose did not predict AUR. Prostate size was the major determinant of AUR. For any given prostate size, prior androgen ablation increased the risk of AUR. Men with larger prostates should be aware of the increased risk when contemplating brachytherapy

190

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

Science.gov (United States)

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

Taschereau, Richard; Roy, René; Pouliot, Jean

2002-07-01

191

125I-labelled cobalamin derivative compatible with intrinsic factor  

International Nuclear Information System (INIS)

A 125I-labelled derivative of cobalamin (vitamin B12) is described which is compatible with intrinsic factor in binding assays. The derivative, [125I]cyanocobalamin-d-iodohistamide, can be readily prepared with a specific activity of 1400 Ci/g. Used as a substitute for [57Co]cyanocobalamin in binding assays, the new derivative can reduce counting times and decrease costs in such assays. (Auth.)

192

Quality control of 125I-brachy therapy seeds  

International Nuclear Information System (INIS)

BARC 125I- Ocuprosta seeds are used in ocular brachytherapy for the treatment of malignant ocular lesions. In order to achieve the overall protection goals set by the regulatory authorities and for safer brachytherapy applications, Quality Assurance (QA) of indigenously produced 125I-seeds have been carried out. Ten batches of sources were subjected to quality validation to ensure compliance with the safety standard of AERB, India and ISO- 2919

193

Preparation of 125I-oestradiol-6-oxime-iodohistamine  

International Nuclear Information System (INIS)

Using oestradiol-17? as a starting material, oestradiol-6-oxime-histamine and 125I-oestradiol-6-oxime-iodohistamine are synthetized. Purified by thin layer chromatography (T.L.C) plate at a specific acivity about 74 MBq/?g determined by self-displacement method, 125I-oestradiol-6-oxime-iodohistamine shows a high stability and a fine immunoreactivity tested by excess antibody binding. Its suitability is suitable for the tracer of radioimmunoassay (RIA)

194

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

Science.gov (United States)

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

Gesztesi, László; Ágoston, Péter; Major, Tibor; G?dény, Mária; Andi, Judit; Lengyel, Zsolt; Polgár, Csaba

2014-09-01

195

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

International Nuclear Information System (INIS)

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 numb 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 inverse preplanning, and intraoperative real-time planning. This technology is not intended to replace the physicist but to accelerate the planning process, making intraoperative treatment planning more effective

196

A comparative study of 19-iodocholesterol-''125I 3-acetate and Na''125I in liquid scintillation measurements  

International Nuclear Information System (INIS)

A comparative study of performance of 19-iodocholesterol-''125I 3-acetate and sodium iodine samples labelled with ''125 I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I''-concentration of 0-90 ug and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol-''125I 3-acetate samples in Toluene-alcohol and 0.04% for Na''125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs

197

Cytotoxicity of 125I-labelled DNA ligand  

International Nuclear Information System (INIS)

Full text: The highly localised radiochemical damage arising from the decay of Auger electron emitting isotopes such as 125I is well known, as is the potential to exploit this phenomenon in cancer therapy, by targeting the effect to the DNA of tumour cells. Most studies have focussed on incorporating the isotope into DNA, for example by using a labelled DNA precursor such as l25I-iododeoxyuridine. On average, each decay of 125I in DNA results in DNA double-stranded breaks, and only 30-100 such events correspond to a lethal lesion. Detailed analysis of the DNA strand breakage in 125I-oligoDNA have shown that the DNA strand containing the covalently attached 125I sustains more damage than the 'opposite' strand. There are some limitations to the use of precursors such as 125I-iododeoxyuridine, and l25I-labeled DNA ligands represent an alternative way to target the Auger emitting isotope to DNA. However, the lower level of damage in the unlabelled strand of 125I-DNA, suggests that the cytotoxic potency of 125I-labeled DNA ligands may be somewhat less than that of 125I-decays in DNA labelled with 125-iododeoxyuridine. Accordingly, the cytotoxicity of 125I-labeled iodoHoechst 33258 has been investigated in K562 cells, by clonogenic survival in soft agar. Incubation of cells in 5 ?M 125I-iodoHoechst 33258 and subsequent measurement ooechst 33258 and subsequent measurement of l25I in washed cells established that 50% of the drug was taken-up by the cells. Similarly, measurement of 125I in washed nuclei prepared by treatment with neutral detergent indicated that 60% of the cellular drug was in the nucleus. 125I decays were accumulated in the labeled cells for extended periods at -70 deg C in 10% DMSO, or for shorter periods at 0.3 deg C , ±DMSO. These storage conditions compromise the clonogenic survival of control (no 125I-ligand ) cells. Compared to cells not exposed to the cold, which have a cloning efficiency of about 55%, it was reduced to 32% and 12% for cells stored at -70 deg C for 48 hours and 96 hours, respectively. Similarly, storage at 0.3 deg C for 8 hours and 48 hours reduced cloning efficiency to 20% and 8% in the absence of DMSO. Cloning efficiency was reduced to 36% and 22% after storage at 0.3 deg C for 8 hours and 48 hours, respectively, in the presence of 10% DMSO. Using the relevant cloning controls, survival curves were obtained in which the dose was expressed as 125I decays per cell. From this data, D37 values of 200 decays per cell, 150 decays per cell and 115 decays per cell were obtained for the frozen and 0.3 deg C conditions, with and without DMSO, respectively

198

The experimental study of 125I seed brachytherapy in human hepatocellular carcinoma bearing nude mice  

International Nuclear Information System (INIS)

Objective: To explore the effect and influence of tumor growth, cell proliferation and apoptosis related protein of 125I seed brachytherapy in human hepatocellular carcinoma (HHC) bearing nude mice. Methods: Twelve HHC BEL-7402 cells bearing nude mice were equally divided into treated and control group. One 125I seed with 33.3 MBq was implanted into each mouse in treated group. Afterward the dimensions of tumor in both groups were measured every 3-4 d and also the tumor volume inhibition rates were calculated. Twenty-one days later, nude mice sacrificed and routine pathological examination proceeded. The expression of proliferating cell nuclear antigen (PCNA), bcl-2 and bax were detected by immunohistochemical methods. Results: The maximum tumor inhibition rate of treated group was 49.2%. Routine pathological examination found degenerative necrosis at the site was nearby the seed but the alive tumor cell still presented faraway from the seed. The expression of PCNA and the ratio of bcl-2/bax in treated group were lower than those in control group. Conclusion: The sustained irradiation of 125I seed brachytherapy can direct kill the HHC cell in nude mice or inhibit the proliferation of tumor cells. (authors)

199

Permanent Left Ventricular Assistance for Outpatients through Surgical Implantation of a Modified Intra-aortic Balloon Pump  

OpenAIRE

There is a large population of patients in end-stage congestive heart failure who cannot be treated by means of conventional cardiac surgery, cardiac transplantation, or chronic catecholamine infusions. In 2 such patients, we provided permanent left ventricular assistance on an outpatient basis by surgically implanting a modified intra-aortic balloon pump. A Dacron-velour graft to the common iliac artery served as a covering for the extravascular portion of the balloon's pneumatic tubing, whi...

Phillips, Steven J.; Kreamer, Robert; Kongtahworn, Chamnahn; Skinner, James R.; Toon, Richard S.; Grignon, Andre?; Kennerly, R. Michael; Zeff, Robert H.; Spector, Mark

1989-01-01

200

Effect of organic matter on 125I diffusion in bentonite  

International Nuclear Information System (INIS)

Through-diffusion method was conducted to investigate the diffusion behavior of 125I in bentonite in present of organic matter, such as polyaminopolycarboxylate EDTA, oxalic acid, hydrazine and humic acid HA. The effective diffusion coefficient De value and rock capacity factor ? were (2.32.6) × 10-11 m2/s and 0.040-0.052, respectively. The small difference showed that iodine was preferentially associated with silicoaluminate mineral as an inorganic form. In present of HA, the Da value of 125I was almost two orders of magnitude higher than that of HA and humic substances HS. The De and ? derived from the experiments were used to simulate its diffusion in the designed bentonite obstacle of high-level radioactive waste repository and the results showed that 125I can be transported from 30 to 50 cm thickness of bentonite to the far-field of repository in several years. (author)

201

Long chain fatty acid uptake in vivo: comparison of [125I]-BMIPP and [3H]-bromopalmitate.  

Science.gov (United States)

Insulin resistance is characterized by increased metabolic uptake of fatty acids. Accordingly, techniques to examine in vivo shifts in fatty acid metabolism are of value in both clinical and experimental settings. Partially metabolizable long chain fatty acid (LCFA) tracers have been recently developed and employed for this purpose: [9,10-3H]-(R)-2-bromopalmitate ([3H]-BROMO) and [125I]-15-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid ([125I]-BMIPP). These analogues are taken up like native fatty acids, but once inside the cell do not directly enter beta-oxidation. Rather, they become trapped in the slower processes of omega and alpha-oxidation. Study aims were to (1) simultaneously assess and compare [3H]-BROMO and [125I]-BMIPP and (2) determine if tracer breakdown is affected by elevated metabolic demands. Catheters were implanted in a carotid artery and jugular vein of Sprague-Dawley rats. Following 5 days recovery, fasted animals (5 h) underwent a rest (n = 8) or exercise (n = 8) (0.6 mi/h) protocol. An instantaneous bolus containing both [3H]-BROMO and [125I]-BMIPP was administered to determine LCFA uptake. No significant difference between [125I]-BMIPP and [3H]-BROMO uptake was found in cardiac or skeletal muscle during rest or exercise. In liver, rates of uptake were more than doubled with [3H]-BROMO compared to [125I]-BMIPP. Analysis of tracer conversion by TLC demonstrated no difference at rest. Exercise resulted in greater metabolism and excretion of tracers with approximately 37% and approximately 53% of [125I]-BMIPP and [3H]-BROMO present in conversion products at 40 min. In conclusion, [3H]-BROMO and [125I]-BMIPP are indistinguishable for the determination of tissue kinetics at rest in skeletal and cardiac muscle. Exercise preferentially exacerbates the breakdown of [3H]-BROMO, making [125I]-BMIPP the analogue of choice for prolonged (>30 min) experimental protocols with elevated metabolic demands. PMID:18481132

Shearer, Jane; Coenen, Kimberly R; Pencek, R Richard; Swift, Larry L; Wasserman, David H; Rottman, Jeffrey N

2008-08-01

202

Brain necrosis after permanent low-activity iodine-125 implants. Case report and review of toxicity from focal radiation  

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Focal irradiation has emerged as a useful modality in the management of malignant brain tumors. Its main limitation is radiation necrosis. We report on the radiation dose distribution in the cerebellum of a patient who developed imaging and autopsy diagnosis of radiation necrosis after permanent iodine-125 implants for a solitary osseous plasmacytoma of her left occipital condyle. A 55-year-old woman initially presented with neck and occipital pain and a lytic lesion of her left occipital condyle. A cytological diagnosis of solitary osseous plasmacytoma was made by transpharyngeal needle biopsy. After an initial course of external beam radiation, the patient required further treatment with systemic chemotherapy 21 months later for clinical and radiographic progression of her disease. She ultimately required subtotal surgical resection of an ana-plastic plasmacytoma with intracranial extension. Permanent low-activity iodine-125 seeds were implanted in the tumor cavity. Satisfactory local control was achieved. However, clinical and imaging signs of radiation damage appeared 28 months after iodine-125 seed implantation. Progressive systemic myeloma led to her death 11 years after presentation and 9 years after seed implantation. Radiation dose distribution is described, with a discussion of toxicity from focal radiation dose escalation. (author)

203

Double Intervention in Single Sitting: Percutaneous Device Closure and Permanent Pacemaker Implantation in a Patient with Atrial Septal Defect  

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Full Text Available Context: Atrial septal defect may rarely be associated with other cardiac diseases such as arrhythmia, and may require additional intervention. Case report: A 16-year-old boy presented with effort dyspnea, tiredness, and fatigue. The electrocardiograph revealed right bundle branch block, atrioventricular block, and left axis deviation. Ostium secundum type of atrial septal defect was detected by transthoracic echocardiography and was confirmed by transesophageal echocardiography. The patient was advised to undergo percutaneous device closure. Permanent pacemaker implantation was also suggested considering the risk of fatal arrhythmias associated with atrioventricular block. Consequently, patient underwent percutaneous atrial septal defect closure and implantation of pacemaker in a single sitting. Both the procedures were successful, after which the patient showed remarkable symptomatic improvement. Conclusion: In atrial septal defect patients with unexplained atrioventricular block, closure of atrial septal defect and implantation of pacemaker in single sitting appear to be an attractive modality.

Raghu Cherukupalli

2014-11-01

204

Computer assisted treatment planning for 125I ophthalmic plaque radiotherapy  

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This paper describes a computer program for planning the treatment of ocular tumors with 125I plaques. The program permits the input of the tumor configuration into a model eye and facilitates the viewing of the relative geometry of the tumor and various eye structures in different perspectives. Custom-designed 125I plaques can be localized onto the globe, and dose distributions can be calculated and superimposed on the eye structures in any plane or on the inner eye surface. The program allows efficient evaluation of the plaque design in terms of radiation dose distribution relative to the tumor and critical structures

205

Dosimetric characterization of the GammaClip™{sup 169}Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection  

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Purpose: A novel {sup 169}Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed {sup 169}Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including S{sub K}, D-dot (r,?), ?, g{sub L}(r), F(r, ?), ?{sub an}(r), and ?{sub an} were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h{sup ?1} U{sup ?1}. The uncertainty in the dose to water calculations, D-dot (r,?), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, ?{sub an}, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r{sup ?2}. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose values were fit to a fifth order polynomial and dual exponential regression. Since the source is not axially symmetric, angular Monte Carlo calculations were performed at 1 cm which determined that the maximum azimuthal anisotropy was less than 8%.Conclusions: With a higher photon energy, shorter half-life and higher initial dose rate {sup 169}Yb is an interesting alternative to {sup 125}I for the treatment of nonsmall cell lung cancer.

Currier, Blake [Medical Physics, University of Massachusetts Lowell, 1 University Avenue, Lowell, Massachusetts 01854 (United States); Munro, John J. III [Source Production and Equipment Co., Inc., 113 Teal Street, St. Rose, Louisiana 70087 (United States); Medich, David C. [Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609 (United States)

2013-08-15

206

Dosimetric characterization of the GammaClip™169Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection  

International Nuclear Information System (INIS)

Purpose: A novel 169Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed 169Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including SK, D-dot (r,?), ?, gL(r), F(r, ?), ?an(r), and ?an were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h?1 U?1. The uncertainty in the dose to water calculations, D-dot (r,?), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, ?an, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r?2. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose values were fit to a fifth order polynomial and dual exponential regression. Since the source is not axially symmetric, angular Monte Carlo calculations were performed at 1 cm which determined that the maximum azimuthal anisotropy was less than 8%.Conclusions: With a higher photon energy, shorter half-life and higher initial dose rate 169Yb is an interesting alternative to 125I for the treatment of nonsmall cell lung cancer

207

An algorithm for efficient metal artifact reductions in permanent seed implants  

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

208

Dose escalation in permanent brachytherapy for prostate cancer: dosimetric and biological considerations  

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No prospective dose escalation study for prostate brachytherapy (PB) with permanent implants has been reported. In this work, we have performed a dosimetric and biological analysis to explore the implications of dose escalation in PB using 125I and 103Pd implants. The concept of equivalent uniform dose (EUD), proposed originally for external-beam radiotherapy (EBRT), is applied to low dose rate brachytherapy. For a given 125I or 103Pd PB, the EUD for tumour that corresponds to a dose distribution delivered by EBRT is calculated based on the linear quadratic model. The EUD calculation is based on the dose volume histogram (DVH) obtained retrospectively from representative actual patient data. Tumour control probabilities (TCPs) are also determined in order to compare the relative effectiveness of different dose levels. The EUD for normal tissue is computed using the Lyman model. A commercial inverse treatment planning algorithm is used to investigate the feasibility of escalating the dose to prostate with acceptable dose increases in the rectum and urethra. The dosimetric calculation is performed for five representative patients with different prostate sizes. A series of PB dose levels are considered for each patient using 125I and 103Pd seeds. It is found that the PB prescribed doses (minimum peripheral dose) that give an equivalent EBRT dose of 64.8, 70.2, 75.6 and 81 Gy with a fraction size of 1.8 Gy and 81 Gy with a fraction size of 1.8 Gy are 129, 139, 150 and 161 Gy for 125I and 103, 112, 122 and 132 Gy for 103Pd implants, respectively. Estimates of the EUD and TCP for a series of possible prescribed dose levels (e.g., 145, 160, 170 and 180 Gy for 125I and 125, 135, 145 and 155 for 103Pd implants) are tabulated. The EUD calculation was found to depend strongly on DVHs and radiobiological parameters. The dosimetric calculations suggest that the dose to prostate can be escalated without a substantial increase in both rectal and urethral dose. For example, increasing the PB prescribed dose from 145 to 180 Gy increases EUD for the rectum by only 3%. Our studies indicate that the dose to urethra can be kept within 100-120% of the prescription dose for all the dose levels studied. In conclusion, dose escalation in permanent implant for localized prostate cancer may be advantageous. It is dosimetrically possible to increase dose to prostate without a substantial increase in the dose to the rectum and urethra. Based on the results of our studies, a prospective dose escalation trial for prostate permanent implants has been initiated at our institution

209

Preparation of 125I-labeled monoclonal antibody of bladder neoplasm using lactoperoxidase  

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125I-labelled monoclonal antibody of bladder neoplasm (125I-L4B4) is prepared using lactoperoxidase. The in-vivo radioactive distribution of 125I-L4B4 in bare mice shows that 125I-L4B4 concentrates in the tumour

210

Quality of permanent prostate implants using automated delivery with seedSelectronTM versus manual insertion of RAPID StrandsTM  

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Background and purpose: To compare the quality of manually inserted RAPID Strand implants with automatically inserted selectSeed implants using volumetric and dosimetric parameters. Patients and methods: Patients with T1 to T2 prostate carcinoma were treated with brachytherapy. The 125I seeds were implanted in the prostate in three different ways: manual insertion of RAPID Strands (R); insertion of selectSeeds using the seedSelectron (S); a combination of both techniques: manual insertion of RAPID Strands in the left half of the prostate and insertion of selectSeeds with the seedSelectron in the right half of the prostate (RS). The comparison is based on implant and target specific parameters. The implant specific parameters, V100, homogeneity index (HI), and natural dose ratio (NDR), were determined at the time of implantation and four weeks later. MR images taken four weeks after the implantation were used for the calculation of the target specific parameters: D90, HI, external index (EI), and conformation number (CN). Results: We found no significant difference between the groups of implants (R, S, RS) for the implant specific parameters V100, HI, and NDR at t0 and neither at t4w. For each group, the V100 values decreased significantly with time between t0 and t4w. The target specific parameters D90, HI, EI and CN were not significantly different between there not significantly different between the groups. For the group of patients with both RAPID Strands and selectSeeds, we found a significant difference in D90 between both halves of the prostate. Conclusions: The dosimetry parameters of a newly introduced implant technique using an automatic seed afterloader were not significantly different from the parameters of a manual insertion technique using RAPID Strands. Since either technique has its advantages and disadvantages regarding seed migration, physics quality assurance, efficiency, logistics, and ease of use, it was decided to use both techniques and to continue evaluations

211

Chemical influence on the decay constant of 125I  

International Nuclear Information System (INIS)

The chemical influence on the electron capture decay of 125I has been studied. The decay constant difference between NaIO3 and Na2H3IO6 has been assessed and measured. The results obtained are discussed in terms of the isomer shift of Moessbauer iodine isotopes

212

Preclinical pharmacological study on 125 I-IPPA  

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Myocardial uptake of 125I-IPPA in rats showed a peak of 4.4% of injected dose per gram. The half elimination time of myocardium was 3.8 min and the maximal uptake of thyroid is only 0.005%ID/organ at 120 min. The initial half time of 2.7 min in rabbits was obtained from the elimination curve of radioactivity in blood. In vitro binding test for 125I-IPPA to HSA showed rather constant level of activation during tow hours. The second peak of extraction was observed in major organs of rats, in rabbits' elimination of radioactivity and in binding test for 125I-IPPA to albumin in vivo. Toxicity trial was up to standard. The tolerance of a mouse to IPPA was 560 times as high as that of a person to IPPA. It demonstrated that 125I-IPPA could be quickly extracted by myocardium, and its catabolite were excreted in the urine with almost no iodine loss. All the results were found to agree with the expectations based on the principal metabolic path of phenyl fatty acid

213

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

International Nuclear Information System (INIS)

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

214

Dose rate effect of [sup 125]I irradiation on normal rabbit eyes and experimental choroidal melanoma  

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The dose rate effect of radiation by [sup 125]I plaque on choroidal melanoma and normal intraocular tissue was studied. In the first part of the experiment, high activity plaques (HAP) and low activity plagues (LAP) were implanted on rabbit eyes with experimental Greene choroidal melanoma to deliver a total dose of 10 000 cGy to the tumor apex. The mean dose rate calculated at 0.5 mm from the inner sclera in eight eyes with high activity plaques was 3341.5 cGy hr[sup -1] while that in ten eyes with low activity plaques was 239.9 cGy hr[sup -1]. For tumors less than 1.0 mm in height, both groups showed complete tumor regression at the tumor implantation site after plaque treatment. For tumours more than 1.0 mm in height, two out of two eyes in the low activity plaque group and one of four eyes in the high activity plaque group failed to show complete tumor regression. In the second part of the experiment, [sup 125]I plaques were implanted on the sclera of 12 normal rabbits' eyes. Six received high dose rate plaque treatment, while the other six received low dose rate plaque treatment. Clinical and histologic examinations demonstrated more damaging effects to the normal chorioretinal tissues at the plaque implantation site in the high dose rate plaque group. These results suggest that high dose rate plaques are more effective than low dose rate plaques when tumor height is statistically controlled. (Author).

Yang, C.M.; Olsen, K.R. (Bascom Palmer Eye Inst., Miami, FL (United States)); Schwade, J.G.; Houdek, P.V.; Markoe, A.M.; Pisciotta, V.; Xiaodong Wu (Miami Univ., FL (United States). School of Medicine)

1993-11-01

215

Quality assurance calibration of 125I rapid strand in a sterile environment  

International Nuclear Information System (INIS)

Purpose: 125I seeds encased in stiffened absorbable suture material, commercially available from Amersham Healthcare as 125I Rapid Strand, are not readily calibrated because of the necessity of maintaining the sterility and integrity of the Rapid Strand. A method is proposed to verify the activity of 125I seeds in Rapid Strand in a sterile environment and to provide quality assurance of the resultant loading by autoradiographing loaded needles. Methods and Materials: A sterilizable insert for a Standard Imaging HDR 1000 Plus well chamber was designed to accommodate Amersham's plastic spacing jig that holds the strand. The insert has a cylindrical lead sleeve allowing five of the 10 seeds in the jig to be exposed within the well chamber. A grooved tray for holding a batch of 30 needles was designed for autoradiographing the implant set. Results: Position-dependent calibration factors for each of the seed wells in the jig were determined; then these individual factors were combined into a single chamber factor of 21.6 pA/mCi. Starting from the most distal spacing jig slot, relative position factors were 0.99, 1.00, 0.99, 0.93, 0.73, and 0.13 for the six positions which produced a nonnegligible signal. Anisotropy in the chamber factor was determined by rotating the well in 30 deg. increments about the seeds in the jig. The chamber factor showed only a 0.2% variation with rotational angle. Attenuation due to the Vicryl suture cladding mateion due to the Vicryl suture cladding material was 0.2% and was measured by stripping the Vicryl from the strand and remeasuring the chamber factor with the seeds in their original orientation. In the operating room, charge was collected from sterile Rapid Strands for a fixed time between 30 and 50 s and the measured ion chamber current was compared with the value predicted from Amersham's nominal activity. The average deviation between nominal and measured activity of 73 Rapid Strands tested was +0.5% ± 2.2%. For single measurements, the maximum and minimum deviations observed were +4.8% and -3.7%, respectively. Autoradiographs taken of the entire implant set on an aluminum tray milled to hold the needles confirmed the actual seed loadings. Conclusions: The Rapid Strand calibration procedure described maintains the sterility and integrity of 125I Rapid Strands and verifies that the manufacturer's stated activity is accurate to within 5%

216

Monte Carlo-aided dosimetry of the Symmetra model I25.S06 125I, interstitial brachytherapy seed.  

Science.gov (United States)

A dosimetric study of a new 125I seed for permanent prostate implant, the Symmetra 1251 Seed model I25.S06, has been undertaken utilizing Monte Carlo photon transport calculations. All dosimetric quantities recommended by the AAPM Task Group 43 (TG-43) report have been calculated. Quantities determined are dose rate constant, radial dose function, anisotropy function, anisotropy factor, and anisotropy constant. The recently (January 1999) revised NIST (National Institute of Standards and Technology) 1251 standard for air kerma strength calibration was taken into account as well as updated interaction cross-section data. Calculations were done for the competing model 6702 source for the purpose of comparison. The calculated dose-rate constants for the two seeds are 1.010 and 1.016 cGyh(-1)U(-1) for the Symmetra and model 6702 seeds, respectively. The latter value deviates from the value, 1.039 cGyh(-1)U(-1), recommended in the TG-43 report. The calculated radial dose function for the Symmetra new seed is more penetrating than that of the model 6711 seed (by 20% at 5 cm distance) but agrees closely (within statistical errors) with that of the model 6702 seed up to distances of 10 cm. The anisotropy function for the seed is also close to that for the 6702 seed with a tendency of somewhat more pronounced anisotropy (lower values at small angles from the longitudinal axis). Compared to the model 6711 seed, the Symmetra new seed is more isotropic. The anisotropy constants (the anisotropy function averaged with respect to angle and distance) for the three seed models are within 2%. PMID:10841412

Hedtjärn, H; Carlsson, G A; Williamson, J F

2000-05-01

217

The use of new GAFCHROMIC EBT film for 125I seed dosimetry in Solid Water phantom  

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Radiochromic film dosimetry has been extensively used for intravascular brachytherapy applications for near field within 1 cm from the sources. With the recent introduction of new model of radiochromic films, GAFCHROMIC EBT, with higher sensitivity than earlier models, it is promising to extend the distances out to 5 cm for low dose rate (LDR) source dosimetry. In this study, the use of new model GAFCHROMIC EBT film for 125I seed dosimetry in Solid Water was evaluated for radial distances from 0.06 cm out to 5 cm. A multiple film technique was employed for four 125I seeds (Implant Sciences model 3500) with NIST traceable air kerma strengths. Each experimental film was positioned in contact with a 125I seed in a Solid Water phantom. The products of the air kerma strength and exposure time ranged from 8 to 3158 U-h, with the initial air kerma strength of 6 U in a series of 25 experiments. A set of 25 calibration films each was sequentially exposed to one 125I seed at about 0.58 cm distance for doses from 0.1 to 33 Gy. A CCD camera based microdensitometer, with interchangeable green (520 nm) and red (665 nm) light boxes, was used to scan all the films with 0.2 mm pixel resolution. The dose to each 125I calibration film center was calculated using the air kerma strength of the seed (incorporating decay), exposure time, distance from seed center to film center, and TG43U1S1 recommended dosimetric parameters. Based on tommended dosimetric parameters. Based on the established calibration curve, dose conversion from net optical density was achieved for each light source. The dose rate constant was determined as 0.991 cGy U-1 h-1 (±6.9%) and 1.014 cGy U-1 h-1 (±6.8%) from films scanned using green and red light sources, respectively. The difference between these two values was within the uncertainty of the measurement. Radial dose function and 2D anisotropy function were also determined. The results obtained using the two light sources corroborated each other. We found good agreement with the TG43U1S1 recommended values of radial dose function and 2D anisotropy function, to within the uncertainty of the measurement. We also verified the dosimetric parameters in the near field calculated by Rivard using Monte Carlo method. The radial dose function values in Solid Water were lower than those in water recommended by TG43U1S1, by about 2%, 3%, 7%, and 14% at 2, 3, 4, and 5 cm, respectively, partially due to the difference in the phantom material composition. Radiochromic film dosimetry using GAFCHROMIC EBT model is feasible in determining 2D dose distributions around low dose rate 125I seed. It is a viable alternative to TLD dosimetry for 125I seed dose characterization

218

Prostate dose calculations for permanent implants using the MCNPX code and the Voxels phantom MAX  

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This paper presents the modeling of 80, 88 and 100 of 125I seeds, punctual and volumetric inserted into the phantom spherical volume representing the prostate and prostate phantom voxels MAX. Starting values of minimum and maximum activity, 0.27 mCi and 0.38 mCi, respectively, were simulated in the Monte Carlo code MCNPX in order to determine whether the final dose, according to the integration of the equation of decay at time t = 0 to t = ? corresponds to the default value set by the AAPM 64 which is 144 Gy. The results showed that consider sources results in doses exceeding the percentage discrepancy of the default value of 200%, while volumetric consider sources result in doses close to 144 Gy. (author)

219

Prostate dose calculations for permanent implants using the MCNPX code and the Voxels phantom MAX  

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This paper presents the modeling of 80, 88 and 100 of {sup 125}I seeds, punctual and volumetric inserted into the phantom spherical volume representing the prostate and prostate phantom voxels MAX. Starting values of minimum and maximum activity, 0.27 mCi and 0.38 mCi, respectively, were simulated in the Monte Carlo code MCNPX in order to determine whether the final dose, according to the integration of the equation of decay at time t = 0 to t = {infinity} corresponds to the default value set by the AAPM 64 which is 144 Gy. The results showed that consider sources results in doses exceeding the percentage discrepancy of the default value of 200%, while volumetric consider sources result in doses close to 144 Gy. (author)

Reis Junior, Juraci Passos dos; Silva, Ademir Xavier da, E-mail: jjunior@con.ufrj.b, E-mail: Ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Facure, Alessandro N.S., E-mail: facure@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2010-07-01

220

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

International Nuclear Information System (INIS)

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 103Pd 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 brachythe for image guidance of permanent brachytherapy applications in the breast and, possibly, other sites

221

Thermoluminescent dosimetry of the SourceTech Medical model STM1251 125I seed  

International Nuclear Information System (INIS)

Many new models of 125I seeds are being introduced, mainly due to the increase in prostate seed implants. We have evaluated the SourceTech Medical (STM), model STM1251, 125I seed using thermoluminescent dosimeters (TLDs) in a solid water phantom. TLD cubes, LiF TLD-100, with dimension 1 mm on each edge, were irradiated at various distances, 1, 2, 3, and 5 cm, at angles ranging from 0 deg. to 90 deg. in 10 deg. increments. Sensitivity calibration of the TLDs was achieved by irradiation to 10 cGy with 6 MV x rays from a clinical linear accelerator, Clinac 600C. Concurrent with the 125I seed exposures, several TLDs were also exposed to 10 cGy with the 600C as a control set. Dose rates per unit air kerma strength were determined based on the 1999 NIST traceable standard for the STM1251 seed. They are presented as a function of distance r and angle ?. The TG-43 parameters, including the dose rate constant, ?, anisotropy function, F(r,?), radial dose function, g(r), anisotropy factor, ?an(r), and anisotropy constant, ?, were obtained for use in radiation treatment planning software. The value of ? was determined as 1.07±5.5% cGy U-1 h-1, which is comparable to model 6702 and to the value determined using the point extrapolation method by Kirov and Williamson. We also find agreement between our TLD data and their Monte Carlo results for g(r), F(r,?), ?an(r), and ?. Additionally, agreement and ?. Additionally, agreement is found with the TLD data of Li and Williamson for ? and g(r)

222

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

International Nuclear Information System (INIS)

Purpose: Sixty-seven patients with early-stage breast cancer were treated in a Phase I/II clinical trial using a 103Pd 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 103Pd is safe for the public. Howe03Pd 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

223

Commercial production of 125I-fibrinogen injection  

International Nuclear Information System (INIS)

In 1975 Health Protection Branch approval was received to distribute 125I-Fibrinogen Injection. Since that time over 30.000 vials of this drug have been prepared and used in the detection of venous thrombosis. Diagnosis of venous thrombosis with fibrinogen leg scanning depends on the incorporation of 125I-Fibrinogen into the thrombus, which is then detected by measuring the consequent increase of overlying surface radioactivity using a small Na(Tl) detector. The preparation of the drug relies on careful donor selection to minimize the chance of transmitting hepatitis. Careful separation of the fibrinogen is necessary to ensure that a high concentration of clottable protein is available for iodination. Fibrinogen having a clottable protein content in excess of 80% is iodinated usino. the ICl method. This product must have a consistent high quality. The control procedures used to examine the quality of each batch are described. (author)

224

Amino acid tolerance test using L-?-phenylalanine-125I  

International Nuclear Information System (INIS)

An amino acid tolerance test is described. L-?-phenylalanine-125I was used as representative of L-amino acids. The change in radioactivity of the blood after giving a test dose of tagged L-?-phenylalanine was also investigated. L-?-phenylalanine-125I tolerance curves were found to be irreproducible when the test dose was given without a carrier. The addition of 2.5 g untagged phenylalanine as a carrier to the test dose allowed a reproducible and precise type of tolerance curves. Metformin in a dose of 0.5 g t.d.s. for three days induced an inhibitory effect on amino acid absorption in normal persons. (author)

225

Minimally invasive implantation of an extracorporeal membrane oxygenation circuit used as a temporary left ventricular assist device: a new concept for bridging to permanent cardiac support.  

Science.gov (United States)

The implantation of cardiac assist devices is associated with poor outcome in patients with multiple organ failure and unknown neurologic status. Therefore, temporary left ventricular assist devices (LVAD) using, for example, extracorporeal centrifugal pumps may provide the chance to further evaluate the patient's clinical course and a potential qualification for implantable LVAD therapy. On the other hand, a main disadvantage of the temporary LVAD implantation is the need for redo surgery, increasing the risk of the final LVAD Implantation. To minimize this drawback of the temporary LVAD implantation, we implanted the temporary LVAD using a minimally invasive technique. The operation was done without cardiopulmonary bypass support, and the temporary LVAD was implanted through upper hemisternotomy and left anterior mini-thoracotomy. The patient recovered from multiple organ failure and was successfully bridged to a permanent LVAD therapy. PMID:25370719

Saito, Shunsuke; Fleischer, Bernhard; Maeß, Christoph; Baraki, Hassina; Kutschka, Ingo

2015-03-01

226

Preparation of 19-iodocholesterol labelled with 125 I  

International Nuclear Information System (INIS)

In this paper a new method of synthesis of 19-iodo cholesterol labelled with ''125 I, from commercial cholesterol, is described. Its high chemical (96%) and radiochemical (99.9%) purities high yield and short time of preparation permit us to dispose or a more accessible labelled compound, which results appropriates for clinical investigations and in the diagnosis of disturbances of the suprarenal glands. (Author) 9 refs

227

Absolute measurement of the 125I desintegration rate  

International Nuclear Information System (INIS)

The procedure followed by the Laboratorio de Metrologia Nuclear at the IPEN (Instituto de Pesquisas Energeticas e Nucleares), Sao Paulo - Brazil, for the absolute determination of the 125I desintegration rate by means of the X-(X,?) Coincidence and Sum-Peak methods is described. The results were submitted to the BIPM (Bureau International des Poids et Mesures), France, for an International Comparison of this radionuclide. (author)

228

Killing effect of 125I-UdR on human lymphoma Raji and Daudi cell lines  

International Nuclear Information System (INIS)

Objective: To evaluate the killing effect and the uptake of 125I-UdR on human lymphoma Raji and Daudi cell lines. Methods: The amount of 125I-UdR in the cells and cell nuclei were determined after incubation of different time in RPMI 1640 culturing medium containing different concentrations of 125I-UdR. The killing effects of 125I-UdR on Raji and Daudi cell lines were estimated through MTT assay and cell cycle was analyzed by propidium iodide (PI) staining. Results: The amounts of 125I-UdR in Raji and Daudi cells and cell nuclei were much higher than that of Na125I( P125I-UdR in Raji and Daudi cells were 14 414 ± 95 and (6916 ± 53.69) Bq/106 cell when the concentration was 100 kBq/ml. The amounts of Na125I were 68±3.8 and (324±32.8) Bq/106 cell. The uptake of 125I-UdR in Raji and Daudi cells and cell nuclei increased with the 125I-UdR concentration and incubated time. The cell surviving fractions of 125I-UdR groups was much lower than that of Na125I groups (P125I-UdR groups were (19.78±1.39)% and (43.17±2.69)%; those of Na125I groups were(79.10±1.79)% and (80.36±6.12)%. The surviving fi:actions of 125I-UdR groups reduced with the sup>I-UdR groups reduced with the 125I-UdR concentration. Conclusions: 125I-UdR can Be specially ingested by Raji and Daudi cells and incorporated into DNA, then the cells will be killed. The uptake of 125I-UdR is dose and time dependent. (authors)

229

The pharmacokinetics of 125I-r-Sak in rats  

International Nuclear Information System (INIS)

The purpose is to measure the pharmacokinetic parameters of r-Sak in rats as well as the biodistribution and the excretion of r-Sak in rats. 125I-r-Sak was applied for the purpose. The results showed that the pharmacokinetics of 125I-r-Sak following intravenous injection with two doses (70 ?g/kg and 840 ?g/kg) in rats was in correspondence with 2-compartment-model. The T1/2(?) were 5.47 +- 2.13 and 8.45 +- 4.50 min and T1/2(?) were 96.15 +- 22.29 and 58.78 +- 32.79 min for the two dose groups. AUC were 0.895 +- 0.455 and 38.36 +- 5.181 ?g·min·mL-1. There were no marked differences of T1/2(?) and T1/2(?) between the two dose groups (P > 0.05), but the AUC increased markedly with the dose increasing (P 125I-r-Sak was wide in rats. Radioactivity wa highest in kidney, followed in order by plasma, liver, lung, spleen, heart and brain. Excretion experiment showed that the sum of the accumulative excretion of the ratio-material plus the enrichment of the ratio-material in thyroid was approximately 80% in 96 h

230

Range of high LET effects from 125I decays  

International Nuclear Information System (INIS)

Track structure techniques are applied to calculate energy depositions in cylindrical targets 20 A in diameter (simulating the DNA duplex) containing, or near, 125I decays. Two problems are examined: (1) The possible effects of incorporated versus nonincorporated 125I are evaluated; (2) the extent of the radiological damage along the DNA is described and discussed for individual decays taking place in the DNA. The results of three different calculations are presented: (1) The distribution of the total energy deposited in the target per decay: Here it is shown that the 125I decays deposit considerably more energy than 5-MeV alpha particles when the decay occurs on the central axis of the cylinder. When the decay occurs at 40 A from the axis, the energy depositions are small and infrequent, showing that the iodine decay must occur within this distance to produce a high LET-like effect. (2) The distribution of average energy depositions around a curved cylinder simulating the DNA duplex encircling the nucleosome: There is a rapid decrease in the energy deposited in elements (of size resembling a base pair) away from the location of the decay. At approximately 17 A (approximately 5 bp) from the decay the mean energy deposited in an element is reduced by a factor of 10. (3) The energy deposited in individual elements of the cylinder is presented for single decays: The smooth decrease in average energy depositions with distance from the decay ((2) above) is not reflected in individual decays

231

125I Labelling of Protein Using Immobilized Enzyme  

International Nuclear Information System (INIS)

For an effective solid-phase labelling of protein with 125I, studies on the immobilization of lactoperoxidase (LPO) on the inner wall of polystyrene tubes were carried out. Labelling of bovine serum albumin (BSA) and insulin was also practiced using the LPO immobilized tubes. The immobilized enzyme of about 2.5 ? g/tube was sufficient for small scale labelling since the results of radio-paper chromatography of the labelling mixture of insulin indicated that the yields were sufficiently high (80%) even in the reactions conducted at room temperature for 60 sec. The results of the Sephadex column chromatography indicated that the labelled products were not contaminated with LPO-125I, and the radiochemical purity of the products was more than 90%. In considering the general trend that the 125I labelled protein obtained by using LPO maintains its intactness better than those obtained by using chloramine-T, together with the tendency of yield enhancing with increase of reactants-concentration, the LPO immobilized tube method is estimated to be one of the simple methods of labelling. The product might be applicable without further purification.

232

Labelling of ?-endorphin (?-END) and ?-lipotropin (?-LPH) by 125I  

International Nuclear Information System (INIS)

5 ?g of human ?-endorphin were labelled with 2 mCi 125I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ?Ci/?g.Kept at + 40C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a 125I ?-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-?-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ?g of human ?-lipotropin were labelled with 0.5 mCi 125I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ?Ci/?g was obtained. It remained utilizable for 30 days when kept at + 40C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ?-LPH was 32% for an anti-?-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%

233

Collective excitations in the 123 125I nuclei  

International Nuclear Information System (INIS)

The odd-proton nulei 123I and 125I have been studied in the reactions 121Sb(?, 2n)123I and 123Sb(?, 2n)125I, respectively. The level schemes, spin and parity assignments are based on results obtained from singles ?-ray spectra (Esub(?)=27 MeV) and excitation functions, from measurements of delayed ?-rays, ?-? coincidences, internal conversion electrons and ?-ray angular distributions. High-spin positive- and negative-parity bands with energies up to 2948 keV and spins up to 23/2 in 123I and with energies up to 3775 keV and spins up to 27/2 in 125I have been established. In the decay schemes of both nuclei two separated structures of levels have been observed. One group of levels shows a strong ?J=2 quasirotational pattern predicted by the particle-vibration coupling model. The ?J=1 sequence on a 9/2+ state is assigned as a rotational structure built on the axially symmetric deformed state 9/2+[404]. In 123I a 28 ns isonmer at 2660.0 keV has been found. (Auth.)

234

Validation of K-edge 125I brachytherapy enhancement with silver compounds  

International Nuclear Information System (INIS)

Brachytherapy with radioactive seeds implanted within the tumour volume has demonstrated good success rates in treating certain cancers. In an effort to improve the curative rates in cancer patients, ongoing research is being conducted to enhance the amount of radiation dose that is absorbed within the tumour volume while minimizing the dose absorbed by the surrounding normal tissue. One method for enhancing tumour dose absorption with 125I brachytherapy seeds is to increase the number of photoelectric atomic interactions within the tumour volume by introducing small quantities of a silver compound, taking advantage of the K-edge effect. Because low-energy electrons and Auger electrons are the primary sources of brachytherapy dose enhancement, acquiring accurate experimental measurements of absorbed dose increases is a major challenge. To circumvent this problem, an x-ray fluorescence excitation spectroscopy dosimetry technique supplemented with clinically accepted dosimetry calculations was developed to estimate relative absorbed dose increases in a water phantom containing up to 7.5 mM of silver. Excellent agreement was observed between theoretically derived Monte Carlo dosimetric predictions and experimental measurements. These results successfully demonstrated that K-edge enhanced 125I brachytherapy is indeed possible with future development of a non-toxic silver chelate. (author)

235

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

International Nuclear Information System (INIS)

Purpose: A new technique of adjuvant partial breast irradiation using 103Pd 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

236

Preparation of 19-iodo cholesterol labelled with 125 I; Preparacion del 19-yodocolesterol marcado con 125 I  

Energy Technology Data Exchange (ETDEWEB)

In this paper a new method of synthesis of 19-iodo cholesterol labelled with ''125 I, from commercial cholesterol, is described. Its high chemical (96%) and radiochemical (99.9%) purities high yield and short time of preparation permit us to dispose or a more accessible labelled compound, which results appropriates for clinical investigations and in the diagnosis of disturbances of the suprarenal glands. (Author) 9 refs.

Rodriguez, L.; Rebollo, D. V.; Ruiz, J. M.

1986-07-01

237

Synthesis and radioimmunological characterization of testosterone-3-carboxymethyloxime-tyramine-125 I (T-3-Cmo-Ty-125 I)  

International Nuclear Information System (INIS)

The paper presents the synthesis and radioimmunological characterization of testosterone-3-carboxymethyloxime-tyramine-15 I (T-3-CMO-Ty-125 I), a reagent used as marker in radioimmunoassay (RIA) of steroid hormones. Some of the most adequate techniques of analyzing the steroid hormones are RIA and ELISA (enzyme linked immunosorbent assay) due to their sensitivity and specificity. These techniques do not require advanced purification of the sample. In the view of developing a sensitive RIA technique for assaying the testosterone-3-carboxymethyloxime-tyramine-125 I it is necessary to obtain the reagents as anti-testosterone antibody and radioactive labeled testosterone. The carboxy derivative of the steroid hormone was activated with ethylchloroformiate and tributylamine in dioxan and coupled with tyramine-125 I. Tyramine was labelled by chloramine method. The marker was purified by thin layer chromatography and extracted in methylic alcohol. Radioimmunological characterization of the marker was carried out with the help of the anti testosterone antibody obtained in our laboratory. (authors)

238

Implante de marcapasso definitivo em gestante portadora de valvopatia mitral reumática Implante de marcapaso definitivo en gestante portadora de valvulopatía mitral reumática Permanent pacemaker implantation in a pregnant woman with rheumatic mitral valve disease  

Directory of Open Access Journals (Sweden)

Full Text Available Descrevemos um caso raro de implante de marcapasso definitivo em gestante, portadora de valvopatia mitral reumática, previamente submetida à valvoplastia percutânea por cateter-balão. A paciente apresentava bloqueio atrioventricular de grau avançado, de causa não-reversível, sintomático e manifesto no 3º trimestre da gestação.Describimos un caso raro de implante de marcapaso definitivo en gestante, portadora de valvulopatía mitral reumática, previamente sometida a valvuloplastia percutánea por catéter balón La paciente presentaba bloqueo atrioventricular en grado avanzado, de causa irreversible, sintomático y manifiesto en el 3º trimestre de gestación.We describe a rare case of permanent pacemaker implantation in a pregnant woman with rheumatic mitral valve disease previously undergoing percutaneous balloon valvuloplasty. She presented symptomatic advanced atrioventricular block of non-reversible cause and manifest in the third trimester of gestation.

Rodrigo Barbosa Esper

2009-05-01

239

Implante de marcapasso definitivo em gestante portadora de valvopatia mitral reumática / Permanent pacemaker implantation in a pregnant woman with rheumatic mitral valve disease / Implante de marcapaso definitivo en gestante portadora de valvulopatía mitral reumática  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese, Spanish Abstract in portuguese Descrevemos um caso raro de implante de marcapasso definitivo em gestante, portadora de valvopatia mitral reumática, previamente submetida à valvoplastia percutânea por cateter-balão. A paciente apresentava bloqueio atrioventricular de grau avançado, de causa não-reversível, sintomático e manifesto [...] no 3º trimestre da gestação. Abstract in spanish Describimos un caso raro de implante de marcapaso definitivo en gestante, portadora de valvulopatía mitral reumática, previamente sometida a valvuloplastia percutánea por catéter balón La paciente presentaba bloqueo atrioventricular en grado avanzado, de causa irreversible, sintomático y manifiesto [...] en el 3º trimestre de gestación. Abstract in english We describe a rare case of permanent pacemaker implantation in a pregnant woman with rheumatic mitral valve disease previously undergoing percutaneous balloon valvuloplasty. She presented symptomatic advanced atrioventricular block of non-reversible cause and manifest in the third trimester of gesta [...] tion.

Rodrigo Barbosa, Esper; Remo Holanda de Mendonça, Furtado; Flávio, Tarasoutchi; Guilherme Sobreira, Spina; Max, Grinberg; Walkiria Samuel, Ávila.

2009-05-01

240

Precipitation of (125I) iodothyronins by ethacridine (Preprint No. CT-61)  

International Nuclear Information System (INIS)

The use of a new reagent ethacridine (Rivanolsup(TM)), an acridine dye, for precipitation of thyroid hormones (125I) triiodothyronine (125I-T3) and 125I) thyroxin (125I-T4) has been described. Effect of pH, time and concentration of ethacridine has been studied. The use of ethacridine for rapid radiochemical (RC) purity determination is also studied. (author)

241

125I-progesterone radioimmunoassay for fertility control in cows  

International Nuclear Information System (INIS)

A 125I RIA has been developed for progesterone determination in full-cream milk, skimmed milk and blood plasma. Because of its specificity, accuracy and practicability it is particularly suitable for routine work. First experience has been gained in field studies on fertility control of cows. As early as one estrous cycle after insemination, non-pregnant cows can be distinguished from presumably pregnant ones with a high degree of certainty, so that a timely re-insemination of those animals is rendered possible. Insemination outside the estrous cycle was found to be one reason for supposed fertility disorders

242

Production of 125I seed sources for brachytherapy uses  

International Nuclear Information System (INIS)

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

243

Treatment of hyperthyroidism: use of 131I and 125I  

International Nuclear Information System (INIS)

Factors related to late hypothyroidism following the use of 131I for treatment of hyperthyroidism are discussed with regard to age of patient, size of dose, previous surgery, immune status, and others. Possible reasons for the post-therapeutic hypothyroidism are discussed with regard to effects of radiation on the reproductive capacity of thyroid cells, effects of radiation on blood vessels, and dose distribution of radioiodine. The following therapeutic strategies are discussed: reduction of initial dose; multiple small doses; high dose radioiodine followed by replacement therapy; the use of external beam irradiation; and the use of 125I

244

Localization of linked 125I seeds in postimplant TRUS images for prostate brachytherapy dosimetry  

International Nuclear Information System (INIS)

Purpose: To demonstrate that 125I seeds can be localized in transrectal ultrasound (TRUS) images obtained with a high-resolution probe when the implant is performed with linked seeds and spacers. Adequate seed localization is essential to the implementation of TRUS-based intraoperative dosimetry for prostate brachytherapy. Methods and Materials: Thirteen preplanned peripherally loaded prostate implants were performed using 125I seeds and spacers linked together in linear arrays that prevent seed migration and maintain precise seed spacing. A set of two-dimensional transverse images spaced at 0.50-cm intervals were obtained with a high-resolution TRUS probe at the conclusion of the procedure with the patient still under anesthesia. The image set extended from 1.0 cm superior to the base to 1.0 cm inferior to the apex. The visible echoes along each needle track were first localized and then compared with the known construction of the implanted array. The first step was to define the distal and proximal ends of each array. The visible echoes were then identified as seeds or spacers from the known sequence of the array. The locations of the seeds that did not produce a visible echo were interpolated from their known position in the array. A CT scan was obtained after implantation for comparison with the TRUS images. Results: On average, 93% (range, 86-99%) of the seeds were visible in the TRUS images. However, it was possible to localize 100% of the , it was possible to localize 100% of the seeds in each case, because the locations of the missing seeds could be determined from the known construction of the arrays. Two factors complicated the interpretation of the TRUS images. One was that the spacers also produced echoes. Although weak and diffuse, these echoes could be mistaken for seeds. The other was that the number of echoes along a needle track sometimes exceeded the number of seeds and spacers implanted. This was attributed to the overall length of the array, which was approximately 0.5 cm longer than the center-to-center distance between the first and last seed owing to the finite length of the seeds at the ends of the array. When this occurred, it was necessary to disregard either the most distal or most proximal echo, which produced a 0.5-cm uncertainty in the location of the array in the axial direction. For these reasons, simply localizing the visible echoes in the TRUS images did not guarantee the reliable identification of the seeds. Conclusion: Our results have demonstrated that a high percentage (>85%) of the implanted 125I seeds can be directly visualized in postimplant TRUS images when the seeds and spacers are linked to preclude seed migration and rotation and when the images are obtained with a high-resolution TRUS probe. Moreover, it is possible to localize 100% of the seeds with the mechanism of linked seeds because the locations of the missing seeds can be determined from the known construction of the arrays

245

Transiliac permanent pacemaker implantation after extraction of infected pectoral pacemaker systems.  

Science.gov (United States)

Infected pectoral pacemaker systems were extracted in 5 patients and new pacemakers were reimplanted in a pelvic pocket through the iliac veins. In patients who have infected pectoral pacemaker systems, this easy and safe technique provides an alternate route for reimplantation of permanent pacemakers. PMID:10468093

Erdogan, O; Augostini, R; Saliba, W; Juratli, N; Wilkoff, B L

1999-08-15

246

Postimplantation dosimetric analysis of permanent transperineal prostate implantation: improved dose distributions with an intraoperative computer-optimized conformal planning technique  

International Nuclear Information System (INIS)

Purpose: To compare the target coverage and dose to normal tissues after I-125 transperineal permanent implantation (TPI) of the prostate in 90 patients treated with one of three different transperineal techniques. Methods and Materials: Detailed postimplant dosimetric evaluations of permanent I-125 implantation procedures were performed on 30 consecutive patients treated between 1995-1996 who underwent TPI using a preplanning CT-based technique, on 30 consecutive patients treated in 1997-1998 who underwent an ultrasound-guided approach with intraoperative determination of seed distribution based on an I-125 nomogram, and on 30 consecutive patients in 1998-1999 who underwent TPI with intraoperative computer-based 3-dimensional conformal optimization. For all three techniques, postimplant CT scans were obtained 4-6 hours after TPI. Dosimetric parameters included V100, V90, V150, D100, D90, D80, as well as maximal and average doses to the urethra and rectal wall. These parameter outcomes are reported as a percentage of the prescription dose. Results: The intraoperative 3D-optimized technique (I-3D) provided superior target coverage with the prescription dose for all dosimetric variables evaluated compared to the other treatment techniques. The median V100, V90, and D90 values for the I-3D technique were 96%, 98%, and 116%, respectively. In contrast, the V100, V100, V90, and D90 values for the CT preplan and ultrasound manual optimization approaches were 86%, 89%, and 88%, respectively and 88%, 92%, and 94%, respectively (I-3D versus other techniques: p < 0.001). The superior target coverage with the I-3D technique was also associated with a higher cumulative implant activity required by the optimization program. A multivariate analysis determined that the treatment technique (I-3D versus other approaches) was an independent predictor of improved target coverage for each parameter analyzed (p < 0.001). In addition, higher cumulative implant activities and smaller prostate target volumes were independent predictors of improved target coverage. The maximum and average urethral doses were significantly lower with the I-3D technique compared to the other techniques; a modest increase in the average rectal dose was also observed with this approach. Conclusion: Three-dimensional intraoperative computer optimized TPI consistently provided superior target coverage with the prescription dose and significantly lower urethral doses compared to two other techniques used. These data provide proof-of-principle that improved therapeutic ratios can be achieved with the integration of more sophisticated intraoperative planning for TPI and may potentially have a profound impact on the outcome of patients treated with this modality

247

Practical application of /sup 125/I-fibrinogen leg scanning  

Energy Technology Data Exchange (ETDEWEB)

The diagnosis of venous thrombosis by radioiodine-labeled fibrinogen scanning depends upon the incorporation of circulating labeled fibrinogen into a developing or established thrombus which is then detected by measuring the increase of overlying surface radioactivity with an isotope detector. The scanning procedure is simple and rapid, and one technician can screen 15 to 20 patients daily. A single intravenous injection of 100 ..mu..Ci of /sup 125/I-fibrinogen enables scanning to be performed for approximately 7 days. leg scanning has been a valuable research tool and is also useful for the clinical management of patients with venous thrombosis. Its limitations are its insensitivity to iliac vein thrombosis and relative insensitivity to thrombi in the upper thigh, and when used diagnostically in patients with clinically suspected venous thrombosis there is a delay of up to 2 days before a positive result is obtained. For these reasons leg scanning should not be used alone in patients with clinically suspected venous thrombosis. The practical indications for using /sup 125/I-fibrinogen leg scanning are (1) for diagnosis of clinically suspected venous thrombosis when used in combination with impedance plethysmography; (2) detection of acute venous thrombosis in patients with chronic venous insufficiency; (3) screening patients who develop calf vein thrombosis when there is contraindication to anticoagulant therapy; and (4) screening certain high-risk patients and patient groups in whom the prophylaxis is either contraindicated or ineffective.

Hull, R.D. (Chedoke-McMaster Hospitals, Hamilton, Ontario, Canada); Hirsh, J.

1981-07-01

248

Practical application of 125I-fibrinogen leg scanning  

International Nuclear Information System (INIS)

The diagnosis of venous thrombosis by radioiodine-labeled fibrinogen scanning depends upon the incorporation of circulating labeled fibrinogen into a developing or established thrombus which is then detected by measuring the increase of overlying surface radioactivity with an isotope detector. The scanning procedure is simple and rapid, and one technician can screen 15 to 20 patients daily. A single intravenous injection of 100 ?Ci of 125I-fibrinogen enables scanning to be performed for approximately 7 days. leg scanning has been a valuable research tool and is also useful for the clinical management of patients with venous thrombosis. Its limitations are its insensitivity to iliac vein thrombosis and relative insensitivity to thrombi in the upper thigh, and when used diagnostically in patients with clinically suspected venous thrombosis there is a delay of up to 2 days before a positive result is obtained. For these reasons leg scanning should not be used alone in patients with clinically suspected venous thrombosis. The practical indications for using 125I-fibrinogen leg scanning are (1) for diagnosis of clinically suspected venous thrombosis when used in combination with impedance plethysmography; (2) detection of acute venous thrombosis in patients with chronic venous insufficiency; (3) screening patients who develop calf vein thrombosis when there is contraindication to anticoagulant therapy; and (4) screening certain high-risk patients and screening certain high-risk patients and patient groups in whom the prophylaxis is either contraindicated or ineffective

249

Measurement of mucosal blood flow by assay of absorption of 125I from the intestinal lumen  

International Nuclear Information System (INIS)

A method which utilized the absorption of 125I as a measure of intestinal mucosal blood flow was developed. In the pentobarbital anesthetized dog a segment of mid-jejunum was isolated from adjacent vasculature and perfused with 125I solution. Superior mesenteric artery flow, blood flow to the isolated segment of intestine and 125I absorption were measured. Changes in 125I absorption were found to correlated closely with changes in blood flow (r . 0.95). Using an autoradiographic technique 125I absorption was found to be localized to the intestinal mucosa

250

The Effect of Radiation on Complication Rates and Patient Satisfaction in Breast Reconstruction using Temporary Tissue Expanders and Permanent Implants.  

Science.gov (United States)

The optimal method of reconstruction following mastectomy for breast cancer patients receiving radiation therapy (RT) is controversial. This study evaluated patient satisfaction and complication rates among patients who received implant-based breast reconstruction. The specific treatment algorithm analyzed included patients receiving mastectomy and immediate temporary tissue expander (TE), followed by placement of a permanent breast implant (PI). If indicated, RT was delivered to the fully expanded TE. Records of 218 consecutive patients with 222 invasive (85%) or in situ (15%) breast lesions from the Salt Lake City region treated between 1998 and 2009 were retrospectively reviewed, 28% of whom received RT. Median RT dose was 50.4 Gy, and 41% received a scar boost at a median dose of 10 Gy. Kaplan-Meier analyses were performed to evaluate the cumulative incidence of surgical complications, including permanent PI removal. Risk factors associated with surgical events were analyzed. To evaluate cosmetic results and patient satisfaction, an anonymous survey was administered. Mean follow-up was 44 months (range 6-144). Actuarial 5-year PI removal rates for non-RT and RT patients were 4% and 22%, respectively. On multivariate analysis (MVA), the only factor associated with PI removal was RT (p = 0.009). Surveys were returned describing the outcomes of 149 breasts. For the non-RT and RT groups, those who rated their breast appearance as good or better were 63% versus 62%, respectively. Under 1/3 of each group was dissatisfied with their reconstruction. RT did not significantly affect patient satisfaction scores, but on MVA RT was the only factor associated with increased PI removal. This reconstruction technique may be considered an acceptable option even if RT is needed, but the increased complication risk with RT must be recognized. PMID:25772601

Anker, Christopher J; Hymas, Richard V; Ahluwalia, Ravinder; Kokeny, Kristine E; Avizonis, Vilija; Boucher, Kenneth M; Neumayer, Leigh A; Agarwal, Jayant P

2015-05-01

251

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

International Nuclear Information System (INIS)

Purpose: To test, in a prospective Phase I/II trial, a partial breast irradiation technique using a 103Pd 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). Conclusionnths (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.

252

Permanent left ventricular assistance for outpatients through surgical implantation of a modified intra-aortic balloon pump.  

Science.gov (United States)

There is a large population of patients in end-stage congestive heart failure who cannot be treated by means of conventional cardiac surgery, cardiac transplantation, or chronic catecholamine infusions. In 2 such patients, we provided permanent left ventricular assistance on an outpatient basis by surgically implanting a modified intra-aortic balloon pump. A Dacron-velour graft to the common iliac artery served as a covering for the extravascular portion of the balloon's pneumatic tubing, which was stabilized by routing it through the iliac crest. The tubing was then carried ventrally to exit through a stoma just above the inguinal ligament. Before hospital discharge, each patient underwent a 5-day regimen of alternate pumping and ambulation. The patient was then permitted to go home, but returned daily as an outpatient in accordance with individual need, for approximately 6 hours of hemodynamic support. The 1st patient lived 3 months after pump insertion, and the 2nd patient for 38 days. Although the 1st patient developed a fever of unknown origin that prompted us to remove the intra-aortic balloon pump unnecessarily, there was no evidence of infection upon surgical exploration and subsequent tissue culturing; she died, rather, of intractable ventricular fibrillation, apparently consequent to her 36-hour loss of hemodynamic support. The 2nd patient also died of a cause unrelated to the presence of the pump, and on autopsy showed good evidence of healing and absence of infection. On the evidence of this pilot study, we conclude that intermittent left ventricular assistance, through periodic activation of a permanently implanted intra-aortic balloon pump during outpatient visits, warrants further study as an alternative for selected patients with end-stage heart disease, when medical and other surgical options have been exhausted. PMID:15227381

Phillips, S J; Kreamer, R; Kongtahworn, C; Skinner, J R; Toon, R S; Grignon, A; Kennerly, R M; Zeff, R H; Spector, M

1989-01-01

253

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

International Nuclear Information System (INIS)

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 mo 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 has a low risk of serious long term side effects

254

Distal movement of upper permanent molars using midpalatal mini-implant  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese OBJETIVO: verificar se o mini-implante no palato é eficaz como ancoragem direta para distalização dos molares superiores. MÉTODOS: foi utilizado um modelo em acrílico da arcada superior. Após a confecção da canaleta na região correspondente aos alvéolos dentários, os dentes em acrílico foram fixados [...] com cera #7, montado aparelho ortodôntico com a técnica Edgewise e inserido um mini-implante (SIN, São Paulo) no local correspondente à rafe palatina. Foram colocados arco 0,19" x 0,25" e barra transpalatina, soldados na barra dois ganchos para retenção de dois elásticos em cadeia de dois elos, a uma carga de 150g/f de cada lado (Unitek), que se estenderam dos ganchos até o mini-implante. O modelo da maxila foi mergulhado 40 vezes em banheira e fotografado após cada mergulho para observação da movimentação dentária. Os dados foram analisados pela análise da variânçia (ANOVA) e teste de Tukey. RESULTADOS: os molares deslocaram-se distalmente 3,1mm, em média, com inclinação distal entre 3 e 5mm. CONCLUÕES: a movimentação dos molares ocorreu pela inclinação distal, com leve rotação, mas sem efeito extrusivo. Abstract in english OBJECTIVE: To assess whether palatal mini-implants are effective as direct anchorage for distal movement of the upper molars. METHODS: It was used an acrylic model of the upper dental arch. After making a groove in the region corresponding to dental alveolus, acrylic teeth were fixed in groove with [...] #7 wax, with the roots being previously immersed in adhesive wax. The orthodontic appliance was placed according to the Edgewise technique and then a mini-implant (SIN, São Paulo, Brazil) was inserted at the site corresponding to the palatal raphe. A 0.019 x 0.025-in stainless steel archwire was made and attached to the upper arch with elastics. A transpalatal arch bar (0.019 x 0.025in) was mounted and two hooks were soldered to it in order to retain chain elastics (Unitek, Brazil) to be connected to the mini-implant under a force of 1.5 N on each side. The maxillary model was immersed in water 40 times and photographed after each immersion, for observation of dental movements. Analysis of variance (ANOVA) and Tukey's test were employed for analyzing the obtained data. RESULTS: Molars displaced distally 3.1 mm, in average, with distal inclination ranging from 3 to 5 mm. CONCLUSIONS: Molar movements occurred due to distal inclination, with a slight rotation and no extrusive effect.

Ana de Lourdes Sá de, Lira; Sávio, Prado; Mônica Tirre, Araújo; Eduardo Franzotti, Sant' Anna; Antonio Carlos de Oliveira, Ruellas.

2013-04-01

255

Purification of 125I-vasoactive intestinal peptide by reverse-phase HPLC  

International Nuclear Information System (INIS)

VIP was labeled with sodium [125I]iodide, and 125I-VIP was purified by reverse-phase high performance liquid chromatography. Optimal separations of 125I-VIP and unlabeled VIP were obtained using two C18- Novapak columns in series and a gradient of acetonitrile in triethylamine phosphate for elution. The specific activity of the 125I-VIP was 1.99 +/- 0.21 Ci/mumole, approaching the maximum specific activity of monoiodinated VIP (2.26 Ci/mumole). Radioimmunoassay and radioreceptorassay for VIP were more sensitive (2.6-fold, and 2.5-fold, respectively) using 125I-VIP purified by HPLC compared to 125I-VIP obtained from an open-end cellulose column. These results demonstrate the advantage of preparing purified 125I-VIP by HPLC for the accurate assay of VIP and VIP-receptors in tissues and biological fluids

256

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1987-10-01

257

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

International Nuclear Information System (INIS)

125I-Proinsulin or 125I-tyrosylated-C-peptide (125I-tyr-CP) was administered to pregnant Rhesus monkeys by bolus followed by constant infusion to examine placental transfer of these peptides. At the end of each infusion, fetuses were exsanguinated in situ via the umbilical vein. The bolus-constant infusion technique produced a steady state in maternal plasma of immunoprecipitable label, measured using excess insulin or C-peptide antiserum. In animals infused with 125I-proinsulin, analysis of umbilical venous plasma revealed no apparent transfer to the fetus of immunoprecipitable label. In animals infused with 125I-tyr-CP, 3-13% of the umbilical venous plasma radioactivity was immunoprecipitable, representing 1.4-5.8% of the immunoprecipitable radioactivity in maternal plasma at delivery. Gel filtration chromatography of umbilical venous plasma revealed that the immunoprecipitated moiety was a fragment of 125I-tyr-CP. Analysis of maternal plasma showed that the predominant peak of radioactivity represented intact C-peptide. A peak corresponding to the fetal immunoprecipitable peak was also present. Analysis of simultaneous maternal arterial and uterine vein plasma samples showed that degradation of 125I-tyr-CP occurred across the uterus. Studies in one nonpregnant and three postpartum animals indicated that pregnancy increased the rate of metabolism of 125I-tyr-CP. When 125125I-tyr-CP. When 125I-tyr-CP was incubated with trophoblastic cells in culture, degradation to a species corresponding on gel filtration to the immunoprecipitable fetal metabolite was found. We conclude that proinsulin, like insulin, does not traverse the placenta. Immunoreactive fragments of C-peptide do cross, however, and pregnancy alters the metabolism of 125I-tyr-CP, probably owing to placental degradation

258

Clinical research on the treatment effects of radioactive (125)I seeds interstitial brachytherapy on children with primary orbital rhabdomyosarcoma.  

Science.gov (United States)

Rhabdomyosarcoma (RMS) is one of the most common primary orbital malignancies. However, orbital RMS is a very rare disease, especially in childhood, and the tumor has a high degree of malignancy and rapid development. The objective of the present study was to investigate the clinical treatment effects of radioactive (125)I seeds interstitial brachytherapy on children with primary orbital RMS, which may provide a new method for treating RMS in clinical applications. Radioactive (125)I seeds were used in the present study. Primary lesions from ten children with orbital RMS, including three male and seven female patients, were selected as the targeted areas. The activity, number and spatial location of the seeds were optimized and simulated by applying computer three-dimensional treatment planning system (TPS) software. The interstitial implantation of the radioactive (125)I seeds was conducted on children under general anesthesia according to the TPS simulation results. Quality verifications of the operation were conducted by orbital computed tomography and X-ray plain film at the early stage after operation, and the children were followed up. The patients were followed up by October 2012 with an average follow-up time of 57 ± 17.43 months and a median follow-up time of 55 months. Nine cases achieved complete remission, and one case achieved partial remission, resulting in a total efficiency and survival rate of 100.0 % (10/10). Most patients recovered after treatment or had no radiotherapy side effect after the operations, though 20.0 % of the patients (2/10) experienced corneal opacity, eyeball movement disorder, or loss of sight. Radioactive (125)I seeds interstitial brachytherapy was an effective treatment for children with primary orbital RMS. Results from this study may provide a new clinical approach for the treatment of child patients with primary orbital RMS. PMID:25092038

Ge, Xin; Ma, Jianmin; Dai, Haojie; Ren, Ling; Li, Quan; Shi, Jitong

2014-09-01

259

106Ru and 125I radiation dose rate gauge  

International Nuclear Information System (INIS)

Pulse count rate from plastic scintillator is a measure of the dose rate. Low dead time of measured channel and digital processing of measuring head signal with compensation of dead time enables correct registration of very high pulse count rate. The radiation source is set with an accuracy not worse than 0.1 mm in relation to the scintillator, and the movement of the source in horizontal and vertical direction is done with the accuracy of 0.01 mm. Additionally the gauge permits to measure the source activity and to check the uniform distribution of the radioactive material on the source surface. Random error due to pulse count rate fluctuation is negligible. The error due to instability of PTM gain is approx. 1,5% for 106Ru and 5% for 125I. (author)

260

Fragment analysis of DSB induced by 125I  

International Nuclear Information System (INIS)

Recent data suggest that the contribution of small fragments must be considered in the estimation of double-strand breaks (DSB) following high-LET irradiation. The objective of this study was to quantify the correct number of double-strand breaks induced by the Auger emitter 125-I, incorporated into DNA in cells. Also, the correlation between DSB induction and chromatin organization was studied by using different labelling protocols. Hamster V79 cells were either labelled with 125-iodo-deoxyuridine during two cell cycles (asynchronous culture) or by a short pulse in early S-phase (synchronized culture). The cells were frozen after labelling for accumulation of decays at -70 deg C. Cells were then thawed and analysed for DSB induction using PFGE. DNA fragments in the size range of 5 kbp to 5700 kbp were separated. The yields obtained by fragmentation analysis were compared with the yields obtained by conventional FAR assay not including smaller fragments. Fragmentation analysis revealed that incorporation at 'random' positions in the genome (asynchronous cells) resulted in a distribution of DNA fragments similar to low-LET irradiation. The number of DSB/decay was found to be 1.3. Using conventional FAR assay assuming a true random distribution, only 0.9 DSB/decay was found. Analysis of synchronized cells, frozen immediately after pulse-labelling or chased for 3.5 h, resulted in a different pattern. Pulse-chase labelling significantly increased the non-random fraction ocantly increased the non-random fraction of fragments after the same number of decays compared to asynchronous irradiation. Also, the DSB induction in cells irradiated in late S-phase was higher compared to cells in early s-phase, implicating a role of chromatin maturation in initial damage. Results obtained with the fragmentation analysis show that 125-I irradiation induces an excess of smaller DNA fragments. Therefore, conventional FAR assay will underestimate the number of DSB produced

261

Pharmacokinetics and organ distribution of 125I-aprindine  

International Nuclear Information System (INIS)

An attempt was made to label aprindine hydrochloride with I-125 by means of an exchange reaction. Organ distribution was determined in 10 rats where radioactivity was measured in the lung, heart, liver, kidney, spleen, brain, transverse muscle tissue and bone sections 5, 10, 30 and 60 min following i.v. injection. The high organ concentration was found in the lung, and also the maximum ratio organ: blood radioactivity was found for this organ. Whole body activity measurements revealed a half-life of nearly 6 hr. Excretion occurred primarily via the faeces. The pharmacokinetic properties of 14C- and 125I-aprindine hydrochloride do not therefore differ significantly. A whole body scintiscanning was carried out on an additional 12 rats and 6 rabbits. This revealed a marked enrichment in the lung compared to other organs in the time period 5 to 10 min. An image of relatively good quality was obtained compared to that of conventional perfusion scintiscanning with 131I-HSA. It is assumed that 125I-aprindine hydrochloride is concentrated in the lung parenchyma and is therefore largely unaffected by the immediate perfusion conditions. This is also confirmed in preliminary studies with 131I-aprindine in the scintiscanning of rabbits where voids of pneumonia activity are shown in the aprindine scintigram whereas with the perfusion method these are not. As expected, the reverse was shown to be true following experimental pulmonary embolism where voids were seen in the perfusion scintigram whilst the 131I-aprindine scintigram revealed hardly any areas of drops in activity. These properties possibly offer an improved diagnostic procedure for differentiating between pneumonia and lung infarct by combination with perfusion scintiscanning. (orig./MG)

262

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

International Nuclear Information System (INIS)

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

263

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

Energy Technology Data Exchange (ETDEWEB)

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

Wang, Haofan; Pullambhatla, Mrudula [Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, MD 21231 (United States); Guilarte, Tomas R. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Mease, Ronnie C. [Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, MD 21231 (United States); Pomper, Martin G., E-mail: mpomper@jhmi.edu [Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, MD 21231 (United States); Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)

2009-11-06

264

Synthesis of [125I]iodoDPA-713: A new probe for imaging inflammation  

International Nuclear Information System (INIS)

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

265

Influence of glucose and urea on 125I transport across an anion exchange paper membrane  

International Nuclear Information System (INIS)

In order to study the influence of glucose and urea on the 125I transport across an anion exchange paper membrane, the transmembrane potential, the fluxes, and the concentrations of 125I, glucose and urea within the membrane were measured in the Na125I concentration-cell system containing glucose or urea. Glucose and urea increased the membrane/solution distribution of the iodide ion, but scarcely affected the diffusion process of iodide ion within the membrane

266

Intraperitoneal (125I) insulin absorption during intermittent and continuous peritoneal dialysis  

International Nuclear Information System (INIS)

The authors have measured intraperitoneal (125I) insulin absorption during intermittent and continuous peritoneal dialysis in order to study the following: insulin regulation of blood glucose when administered continuously via dialysate during continuous ambulatory peritoneal dialysis (CAPD) versus when given intermittently and subcutaneously before CAPD; the degree of (125I) insulin retention in plastic CAPD bags, after complete drainage of the dialysis fluid; absorption of (125I) insulin from the dialysate in the peritoneal cavity of diabetic and non-diabetic patients. (Auth.)

267

Labelling of human red cell superoxide dismutase with 125I by the conjugation method  

International Nuclear Information System (INIS)

Human superoxide dismutase (SOD) was labelled with high specific radioactivity by conjugating to an 125I-iodinizated acylating agent. Radiochemical purity of 125I-SOD was more than 96% and its specific activity was 0.74-1.15 MBq/?g. Radioimmunoassay showed that the tracer had a higher radioimmunoactivity. The 125I-SOD antigen was able to combine with its SOD antibody specifically. The binding rate was 56% at the antiserum dilution of 1:10000

268

Model-based dose calculations for 125I lung brachytherapy  

International Nuclear Information System (INIS)

Purpose: Model-baseddose calculations (MBDCs) are performed using patient computed tomography (CT) data for patients treated with intraoperative 125I lung brachytherapy at the Mayo Clinic Rochester. Various metallic artifact correction and tissue assignment schemes are considered and their effects on dose distributions are studied. Dose distributions are compared to those calculated under TG-43 assumptions. Methods: Dose distributions for six patients are calculated using phantoms derived from patient CT data and the EGSnrc user-code BrachyDose. 125I (GE Healthcare/Oncura model 6711) seeds are fully modeled. Four metallic artifact correction schemes are applied to the CT data phantoms: (1) no correction, (2) a filtered back-projection on a modified virtual sinogram, (3) the reassignment of CT numbers above a threshold in the vicinity of the seeds, and (4) a combination of (2) and (3). Tissue assignment is based on voxel CT number and mass density is assigned using a CT number to mass density calibration. Three tissue assignment schemes with varying levels of detail (20, 11, and 5 tissues) are applied to metallic artifact corrected phantoms. Simulations are also performed under TG-43 assumptions, i.e., seeds in homogeneous water with no interseed attenuation. Results: Significant dose differences (up to 40% for D90) are observed between uncorrected and metallic artifact corrected phantoms. For phantoms created with metallic artifact corhantoms created with metallic artifact correction schemes (3) and (4), dose volume metrics are generally in good agreement (less than 2% differences for all patients) although there are significant local dose differences. The application of the three tissue assignment schemes results in differences of up to 8% for D90; these differences vary between patients. Significant dose differences are seen between fully modeled and TG-43 calculations with TG-43 underestimating the dose (up to 36% in D90) for larger volumes containing higher proportions of healthy lung tissue. Conclusions: Metallic artifact correction is necessary for accurate application of MBDCs for lung brachytherapy; simpler threshold replacement methods may be sufficient for early adopters concerned with clinical dose metrics. Rigorous determination of voxel tissue parameters and tissue assignment is required for accurate dose calculations as different tissue assignment schemes can result in significantly different dose distributions. Significant differences are seen between MBDCs and TG-43 dose distributions with TG-43 underestimating dose in volumes containing healthy lung tissue.

269

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2002-07-01

270

A Monte Carlo evaluation of the dosimetric characteristics of the Best[reg] Model 2301 {sup 125}I brachytherapy source  

Energy Technology Data Exchange (ETDEWEB)

Recently a new design of a {sup 125}I brachytherapy source was introduced for interstitial seed implants, particularly for prostate seed implants. This new source is the Best[reg] Model 2301 brachytherapy source. Due to the differences in source design and manufacturing process from one new source to the next, their dosimetric parameters should be determined according to the AAPM TG-43 guidelines. As per AAPM recommendation (Med. Phys. 25 (12) (1998) 2269), it is required to perform the seed dosimetry using at least one experimental study and one Monte Carlo simulation, preferably done by two separate investigators. Other investigators have experimentally determined the dosimetric parameters of this new source. In this project, the Monte Carlo simulated dosimetric parameters of the Best[reg] Model 2301 {sup 125}I source have been provided. The results of this evaluation indicate the value of dose rate constant of 1.01{+-}3% cGy h{sup -1} U{sup -1} in liquid water, which is in good agreement with 1.02{+-}8% cGy h{sup -1} U{sup -1} reported by Nath and Yue, 2002. The anisotropy constant was found to be 0.98 in liquid water.

Sowards, K.T.Keith T.; Meigooni, A.S.Ali S. E-mail: alimeig@uky.edu

2002-09-01

271

A Monte Carlo evaluation of the dosimetric characteristics of the Best Model 2301 125I brachytherapy source.  

Science.gov (United States)

Recently a new design of a 125I brachytherapy source was introduced for interstitial seed implants, particularly for prostate seed implants. This new source is the Best Model 2301 brachytherapy source. Due to the differences in source design and manufacturing process from one new source to the next, their dosimetric parameters should be determined according to the AAPM TG-43 guidelines. As per AAPM recommendation (Med. Phys. 25 (12) (1998) 2269), it is required to perform the seed dosimetry using at least one experimental study and one Monte Carlo simulation, preferably done by two separate investigators. Other investigators have experimentally determined the dosimetric parameters of this new source. In this project, the Monte Carlo simulated dosimetric parameters of the Best Model 2301 125I source have been provided. The results of this evaluation indicate the value of dose rate constant of 1.01 +/- 3% cGyh-1U-1 in liquid water, which is in good agreement with 1.02 +/- 8% cGyh-1U-1 reported by Nath and Yue, 2002. The anisotropy constant was found to be 0.98 in liquid water. PMID:12201138

Sowards, Keith T; Meigooni, Ali S

2002-09-01

272

Binding of in vivo administrated 125-I-triiodothyronine by the rat liver mitochondria  

International Nuclear Information System (INIS)

In vivo administrated 125I-triiodothyronine (125I-T3) was bound by the rat liver mitochondria. About 10 % of hormone was bound with external mitochondrial membrane while the remaining part with matrix and inner mitochondrial membrane. The highest accumulation of 125I-T3 in mitochondria was observed 30 min after injection while in the whole liver homogenate the highest hormone accumulation appeared 15 min post injection. Mitochondrial binding sites have a great capacity for T3 which makes impossible estimation of the kinetic parameters of triiodothyronine-mitochondrium interaction by means of saturation and displacement of 125I-T3. (author)

273

Characterization of two new ETB selective radioligands, [125I]-BQ3020 and [125I]-[Ala1,3,11,15]ET-1 in human heart.  

OpenAIRE

Two new endothelin receptor radioligands, [125I]-BQ3020 and [125I]-[Ala1,3,11,15]ET-1, were characterized in tissue sections of human right atrium and left ventricle. Both radioligands had high affinity ([125I]-BQ3020 right atrium: KD = 0.145 +/- 0.037 nM, left ventricle: KD = 0.107 +/- 0.004 nM; [125I]-[Ala1,3,11,15]ET-1 right atrium: KD = 0.239 +/- 0.036 nM, left ventricle: KD = 0.199 +/- 0.027 nM). Competition binding experiments were performed in the left ventricle. The selective ETA rece...

Molenaar, P.; Kuc, R. E.; Davenport, A. P.

1992-01-01

274

125I-hippuran absorption from the human renal pelvis  

International Nuclear Information System (INIS)

The absorption of 125I-hippuran from human renal pelvis was studied peroperatively in 18 patients with obstruction at the pelviureteric junction. Three types of experiment were included: absorption during induced diuresis, absorption at a constant intrapelvic pressure of 30 cm. H2O, and excretion of the indicator by the contralateral kidney. Total and separate glomerular filtration rate were measured using 51Cr-EDTA clearance technique and isotope renography. Distal tubular function was evaluated as maximum concentration ability. During induced diuresis the intrapelvic pressure increased to an average maximum value of 31.6 cm. H2O. The excretion of isotope from the contralateral kidney varied from one to 44% of the given dose. A significant correlation (r = 0.87) between the maximum intrapelvic pressure obtained and the amount of isotope excreted from the contralateral kidney was demonstrated. At a constant intrapelvic pressure of 30 cm. H2O the excretion of isotope from the contralateral kidney varied from two to 26% of the dosage given. The low value probably depended on the impaired function of the obstructed kidney. Our results show the existence of a significant reflux from the renal pelvis of small molecules, which was affected by renal function, intrapelvic pressure and volume

275

Decontamination of 125I in a medical laboratory  

International Nuclear Information System (INIS)

A radiological laboratory for diagnoses was contaminated by 125I. A large-scale survey of gamma-radiation has been made in different locations of the floors and walls of the lab to determine the contaminated area and its activity. The activity level before decontamination for the wall and floor was 1400 and 2000 Bq/cm2 respectively. Decontamination was carried out by using ethyl alcohol, potassium permanganate, ethylene diamine tetracetic acid and tissue papers. The decontamination factor has been calculated and it was 175 and 200 for the wall and floor respectively. The D and D computer code has been used to calculate Total Effective Dose Equivalent (TEDE). The TEDE from the wall and floor before decontamination were 3.05 and 4.35 ( mSv/yr ) while after decontamination were 18 and 23 ?Sv/yr, respectively. These results are lower than the Egyptian and the international regulations (10 mSv/y for the public) according to International Atomic Energy agency, IAEA, Safety Series, SS, no. 115 (1994). (author)

276

Radioactive 125I Seed Inhibits the Cell Growth, Migration, and Invasion of Nasopharyngeal Carcinoma by Triggering DNA Damage and Inactivating VEGF-A/ERK Signaling  

OpenAIRE

Although radiotherapy technology has progressed rapidly in the past decade, the inefficiency of radiation and cancer cell resistance mean that the 5-year survival rate of patients with nasopharyngeal carcinoma (NPC) is low. Radioactive 125I seed implantation has received increasing attention as a clinical treatment for cancers. Vascular endothelial growth factor-A (VEGF-A) is one of the most important members of the VEGF family and plays an important role in cell migration through the extrace...

Tian, Yunhong; Xie, Qiang; Tian, Yunming; Liu, Ying; Huang, Zuoping; Fan, Cundong; Hou, Bing; Sun, Dan; Yao, Kaitai; Chen, Tianfeng

2013-01-01

277

Preparation of 1-phenyl 3-methyl 4-nitro 5-125I-pyrazole (5-125I-MNPP) as a possible cannabinoid receptor imaging agent  

International Nuclear Information System (INIS)

A rapid method for labelling of 1-phenyl 3-methyl 4-nitro 5-chloro pyrazole (5-Cl-MNPP) with radioactive iodide Na125I via 125I-for-Cl exchange has been reported. This method has been done in dry state (without catalyst and in presence of acetamide), in dimethyl formamide (DMF) as a solvent (without catalyst and in presence of tetrabutyl ammonium bromide (TBAB) as phase transfer catalyst (PTC)). In dry state, a trial to reduce the reaction temperature from 170 to 120 deg C for the reaction between 5-Cl-MNPP and Na125I in presence of acetamide as a molten medium was tested. Using some organic solvents such as ethanol, dimethyl sulfoxide (DMSO), acetonitrile, and DMF, it was found that DMF gave low radiochemical yield of 5-125I-MNPP (25%) within 30 min. However, the addition of 1 mg of TBAB to DMF increased the radiochemical yield of 5-125I-MNPP from 25 to 95 within 30 minutes. The product 5-125I-MNPP was purified by reverse phase, high performance liquid chromatography (HPLC), with radiochemical purity of greater than 98.0%. The biodistribution of 5-125I-MNPP was demonstrated in normal mice through intravenous injection in the tail vein. High uptake in the target organs equal to 2.5±0.22, 10.5±0.21, 4.3±0.27, 3.2±0.18 and 48.5±0.26 for brain, intestines, heart, kidneys and liver respectively was shown. This indicates that, 5-125I-MNPP can be freely penetrate the blood brain bar freely penetrate the blood brain barrier (B.B.B.) and can be expected its usefulness in the quantitative determination of cannabinoid receptor in the brain. (author)

278

Changes in the tumor microenvironment during low-dose-rate permanent seed implantation iodine-125 brachytherapy  

International Nuclear Information System (INIS)

Purpose: There is a lack of data regarding how the tumor microenvironment (e.g., perfusion and oxygen partial pressure [pO2]) changes in response to low-dose-rate (LDR) brachytherapy. This may be why some clinical issues remain unresolved, such as the appropriate use of adjuvant external beam radiation therapy (EBRT). The purpose of this work was to obtain some basic preclinical data on how the tumor microenvironment evolves in response to LDR brachytherapy. Methods and Materials: In an experimental mouse tumor, pO2 (measured by electron paramagnetic resonance) and perfusion (measured by dynamic contrast-enhanced magnetic resonance imaging) were monitored as a function of time (0-6 days) and distance (0-2 mm and 2-4 mm) from an implanted 0.5 mCi iodine-125 brachytherapy seed. Results: For most of the experiments, including controls, tumors remained hypoxic at all times. At distances of 2-4 mm from radioactive seeds (?1.5 Gy/day), however, there was an early, significant increase in pO2 within 24 h. The pO2 in that region remained elevated through Day 3. Additionally, the perfusion in that region was significantly higher than for controls starting at Day 3. Conclusion: It may be advantageous to give adjuvant EBRT shortly (?1 to 2 days) after commencement of clinical LDR brachytherapy, when the pO2 in the spatial regions between seeds should be elevated. If chemotherapy is given adjuvantly, it may best be adminiiven adjuvantly, it may best be administered just a little later (?3 or 4 days) after the start of LDR brachytherapy, when perfusion should be elevated

279

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

International Nuclear Information System (INIS)

Background and purpose: To report on the incidence of benign prostate-specific antigen bounce following permanent I125 prostate brachytherapy, to describe the associations in our population and review the relationship of bounce to subsequent biochemical failure. Materials and methods: From February 2000 to May 2005, 374 patients with localised prostate cancer were treated with I125 permanent prostate brachytherapy at a single institution. A prospectively collected database was used to identify cases of prostate-specific antigen (PSA) bounce, defined as a rise of ?0.2 ng/ml above an initial PSA nadir with subsequent decline to or below that nadir without treatment. The patients who received neo-adjuvant or adjuvant hormone manipulation were excluded. Biochemical failure was determined using the both the ASTRO consensus definition and Phoenix (nadir +2 ng/mL) definition. Results: Two hundred and five patients were identified with a median follow-up of 45 months (24-85). PSA bounce was noted in 79 (37%) men, occurring at a median of 14.8 months (1.7-40.6) following implant. The median peak PSA was 1.8 ng/ml (0.4-7.4) with a bounce magnitude of 0.91 ng/ml (0.2-5.8). When pre- and post-implant factors were assessed for association to bounce, only younger age was statistically significant (p = 0.002). The threshold for biochemical failure as defined by the ASTRO consensus definition (1997) was met in 4 (5%) patients after experiencing bounce as opposients after experiencing bounce as opposed to 19 (15%) non-bounce patients (p = 0.01). The threshold for Phoenix (nadir +2 ng/mL) was met in 6 (7.5%) patients following bounce versus 22 (17%) of non-bounce patients (p = 0.003). Both definitions are prone to false positive calls during bounce. Median PSA velocity during the bounce was 0.08 ng/mL/month (0.02-0.98) and was statistically significantly lower than the median velocity prior to the Phoenix biochemical failure at 0.28 ng/mL/month (0.07-2.04) (p = 0.0005). Conclusion: PSA bounce is a common finding in our population and is associated with a lower rate of subsequent biochemical failure. The noted differences in PSA velocity will require verification in a future analysis to reduce the influence of median follow-up on this finding. Patients should be advised of the potential of bounce in PSA follow-up after permanent I125 prostate brachytherapy and physicians involved in follow-up of prostate brachytherapy patients should be aware of this phenomenon, allowing them to commit to appropriate PSA surveillance, avoiding the premature and inappropriate initiation of salvage therapy during PSA bounce

280

Evaluation of murine placental degradation and transfer of [125I]iodo-epidermal growth factor  

International Nuclear Information System (INIS)

Since epidermal growth factor (EGF) has been postulated to play a role in embryonic and fetal growth, a study was undertaken to assess the placental degradation and transfer of maternally administered EGF. Approximately 5 ng of purified [125I]iodo-EGF were injected iv into day 10, day 13, or day 17 pregnant CD-1 mice; radioactivity in plasma, placentas, and conceptuses was measured up to 2 h after injection. The time course analysis revealed an initial rapid decline in total plasma radioactivity followed by an increase that was maximal by approximately 30 min. Gel filtration (G-15, G-50) chromatography of plasma revealed that by 5 min, radioactivity was associated with free 125I and with material much larger than EGF. No apparent degradation of [125I]iodo-EGF occurred after direct incubation with maternal plasma. Placental radioactivity had an initial phase of decay between 1 and 5 min followed by an increase that became maximal between 30 and 60 min. Extracts of placentas made with 4 M urea in 0.2 M Tris-HCl, pH 8.0, and taken 1-30 min after injection revealed radioactivity coeluting predominantly with [125I]iodo-EGF at 1 min but shifting to mostly free 125I by 30 min. Uptake of radioactivity by conceptuses was not evident until about 15 min, and only free 125I was detected in extracts; the same results were obtained when 5 micrograms unlabeled EGF were injected simultaneously with [125I]iodd simultaneously with [125I]iodo-EGF. Incubation of placental mince with [125I]iodo-EGF yielded [125I]MIT as the apparent major radioactive degradation product. Formation of [125I]MIT in vitro was both time- and temperature-dependent. At 37 C, marked formation of [125I]MIT was observed; at 22 C, only a negligible amount was formed after incubation of mince with [125I]iodo-EGF for 60 min. Incubation of [125I]iodo-EGF with kidney mince yielded predominantly free 125I

281

Progestin receptors in brain and pituitary of 20-day-old fetal mice: an autoradiographic study using [125I]progestin  

International Nuclear Information System (INIS)

The distribution of progestin target sites in the brain and pituitary of estrogen-primed 20-day-old fetal mice was investigated by thaw-mount autoradiography. Three pregnant mice were each implanted sc with a Silastic tube containing estrogen on day 17 and ovariectomized on day 19 of gestation. Twenty-four hours after ovariectomy 10 fetuses (5 males and 5 females) were collected and each injected sc with 0.33 microgram/100 g BW [125I]progestin (SA, 2200 Ci/mM). For competition, two additional fetuses were injected with 20 micrograms R5020 1 h before (Z)-17 beta-hydroxy-17 alpha-(2[125I]iodovinyl)4-estren-3-one [(125I]Progestin) to demonstrate that nuclear uptake and retention of radioactivity were specific for progestin. Two hours after injection of [125I]Progestin all fetuses were mounted, frozen, and sectioned in a cryostat. After 1-37 days of exposure, sections were developed and scanned for labeled cells. Cells with nuclear concentration were found in the male and female preoptic area, within certain nuclear groups in the basal hypothalamus, in the central gray of the midbrain, and in the pituitary. No labeling was detected in the cortex or amygdala. The results indicate that cells in certain regions of the brain and pituitary express progestin receptors at the end of gestation and suggest that progesterone is important for the normal development of these cells

282

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

Energy Technology Data Exchange (ETDEWEB)

The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer, is a problem of public health in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing {sup 125}I radioisotope are implanted in the prostate. The seed consists of a titanium sealed capsule with 0.8 mm external diameter and 4.5 mm length, containing a central silver wire with adsorbed {sup 125}I. The plasma arc welding is one of the viable techniques for the sealing process. The equipment used in this technique is less costly than in other processes. The main objective of this work was the development and the validation of the welding procedure using plasma welding process and the elaboration of a sealing routine according to Good Manufacturing Practices. The development of this work has presented the following phases: cut and cleaning of the titanium material, determination of the welding parameters, development of a device for holding the titanium tube during the welding process, validation of sealed sources according to ISO 2919 Sealed Radioactive Sources - General Requirements and Classification, leakage test according to ISO 9978 Sealed Radioactive Sources - Leakage Test Methods and metallographic assays. The developed procedure, to seal {sup 125}I seeds using plasma welding process, has shown to be efficient, satisfying all the established requirements of ISO 2919. The results obtained in this work have given the possibility to establish a routine production process according to the orientations presented in resolution RDC number 59 - Good Manufacturing Practices do Medical Products of the ANVISA - Brazilian Nacional Agency of Sanitary Surveillance. (author)

Feher, Anselmo

2006-07-01

283

Autoradiographic evidence of 125I-?-endorphin binding sites in the articular cartilage of the rat  

International Nuclear Information System (INIS)

After 125I-?-endorphin was intravenously injected to rats, an autoradiographic study of distal femur articular cartilage was performed. Results show a specific binding of 125I-?-endorphin to chondrocytes, suggesting the possible existence of an opiate modulation of articular cartilage

284

Quality assurance and classification performance testing of 125I - brachytherapy seeds  

International Nuclear Information System (INIS)

125I-seeds are extensively used in ocular and interstitial brachytherapy for the treatment of various malignant lesions. Quality assurance and classification performance testing of indigenously produced 125I-seeds were carried out for ensuring their safety in different brachytherapy applications. The sources were found to qualify Class -43211 specifications, in accordance with AERB SS-3 and ISO-2919. (author)

285

Increased 125I-labelled concanavalin a binding to erythrocytes in diabetes mellitus  

International Nuclear Information System (INIS)

Percentage binding of 125I-labelled concanavalin A to erythrocytes in diabetic patients was significantly higher than that in normal subjects (12.2 +- 2.8 versus 8.1 +- 1.8%, mean +- SD, p 125I-labelled concanavalin A and glycosylated haemoglobin. (orig.)

286

Experimental and clinical treatment of bladder cancer with 125I-iododeoxyuridine  

International Nuclear Information System (INIS)

Radionuclide can cause auger effect through disintegration low-energy electron (125I-iododeoxyuridine (125I-UdR) is an efficient carrier inducting 125I to cell nucleolus, it is incorporated into DNA specificity only in S-phase cells. A series of studies show that 125I can absorb more likely to tumor cells, instead of the normal cell division, thus effectively splitting radiotherapy of malignant lesions. As bladder is a natural lumen, it has a unique easy perfusion and observational. 125I-UdR can kill effiently and selectively the cells of bladder turnout, reducing markedly the ratio of its recurrence of surgical treatment of patients with bladder cancer, so as to improve the survival rate. It can be used as a surgical adjuvant treatment method, is expected to be a safe, efficient and less adverse reaction the new therapies for bladder cancer treatment. (authors)

287

Neuropeptide Y receptor binding sites in rat brain: differential autoradiographic localizations with 125I-peptide YY and 125I-neuropeptide Y imply receptor heterogeneity  

International Nuclear Information System (INIS)

Neuropeptide Y (NPY) receptor binding sites have been localized in the rat brain by in vitro autoradiography using picomolar concentrations of both 125I-NPY and 125I-peptide YY (PYY) and new evidence provided for differentially localized receptor subtypes. Equilibrium binding studies using membranes indicate that rat brain contains a small population of high-affinity binding sites and a large population of moderate-affinity binding sites. 125I-PYY (10 pM) is selective for high-affinity binding sites (KD = 23 pM), whereas 10 pM 125I-NPY labels both high- and moderate-affinity sites (KD = 54 pM and 920 pM). The peptide specificity and affinity of these ligands in autoradiographic experiments match those seen in homogenates. Binding sites for 125I-PYY are most concentrated in the lateral septum, stratum oriens, and radiatum of the hippocampus, amygdala, piriform cortex, entorhinal cortex, several thalamic nuclei, including the reuniens and lateral posterior nuclei, and substantia nigra, pars compacta, and pars lateralis. In the brain stem, 125I-PYY sites are densest in a variety of nuclei on the floor of the fourth ventricle, including the pontine central grey, the supragenual nucleus, and the area postrema. 125I-NPY binding sites are found in similar areas, but relative levels of NPY binding and PYY binding differ regionally, suggesting differences in sites labeled by the two ligands. These receptor localizations resemble the distribution of endogenous NPY in some areasstribution of endogenous NPY in some areas, but others, such as the hypothalamus, contain NPY immunoreactivity but few binding sites

288

Neuropeptide Y receptor binding sites in rat brain: differential autoradiographic localizations with sup 125 I-peptide YY and sup 125 I-neuropeptide Y imply receptor heterogeneity  

Energy Technology Data Exchange (ETDEWEB)

Neuropeptide Y (NPY) receptor binding sites have been localized in the rat brain by in vitro autoradiography using picomolar concentrations of both 125I-NPY and 125I-peptide YY (PYY) and new evidence provided for differentially localized receptor subtypes. Equilibrium binding studies using membranes indicate that rat brain contains a small population of high-affinity binding sites and a large population of moderate-affinity binding sites. 125I-PYY (10 pM) is selective for high-affinity binding sites (KD = 23 pM), whereas 10 pM 125I-NPY labels both high- and moderate-affinity sites (KD = 54 pM and 920 pM). The peptide specificity and affinity of these ligands in autoradiographic experiments match those seen in homogenates. Binding sites for 125I-PYY are most concentrated in the lateral septum, stratum oriens, and radiatum of the hippocampus, amygdala, piriform cortex, entorhinal cortex, several thalamic nuclei, including the reuniens and lateral posterior nuclei, and substantia nigra, pars compacta, and pars lateralis. In the brain stem, 125I-PYY sites are densest in a variety of nuclei on the floor of the fourth ventricle, including the pontine central grey, the supragenual nucleus, and the area postrema. 125I-NPY binding sites are found in similar areas, but relative levels of NPY binding and PYY binding differ regionally, suggesting differences in sites labeled by the two ligands. These receptor localizations resemble the distribution of endogenous NPY in some areas, but others, such as the hypothalamus, contain NPY immunoreactivity but few binding sites.

Lynch, D.R.; Walker, M.W.; Miller, R.J.; Snyder, S.H. (Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA))

1989-08-01

289

¿Es más eficiente el implante de marcapasos permanentes en hospitales de nivel I? / Is the permanent pacemaker implant more efficient in level 1 hospital?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Objetivo: Determinar si el implante de marcapasos permanentes (MPP) y cambio de generador resultan más eficientes en hospitales pequeños. Diseño: Análisis de costeefectividad. Estudio retrospectivo, transversal y observacional de cinco GDR. Ámbito: Los datos son procedentes del conjunto mínimo básic [...] o de datos (CMBD) nacional del año 2007, facilitado por el Ministerio de Sanidad. Pacientes: Son el total de los pacientes que requirieron asistencia en algún hospital nacional por 5 GRD: 115, complicación bradiarrítmica durante la fase aguda de un síndrome coronario, insuficiencia cardíaca o shock; 116, trastorno de conducción sintomático aislado; 117, revisión pero sin cambio de batería; 118, aplicación de una nueva, y 549, implantación o revisión pero con complicaciones graves. Variables de interés principales: Se analizaron variables demográficas, clínicas (número de diagnósticos secundarios (NDS), de procedimientos (NP), mortalidad) y de gestión (estancia total y preoperatoria (Epo), forma de acceso y alta, tamaño de hospital), definiendo ineficiente una estancia superior 2 días a la media. Resultados: 23.154 episodios (5,3% en hospitales Abstract in english Objective: To determine if permanent pacemaker implants (PPM) interventions and change of generator are more efficient in small hospitals. Design: A cost-effective analysis and retrospective, cross-sectional and observational study of diagnostic related groups (DRG). Setting: The data was obtained f [...] rom the national Minimum Basic Data Set (MBDS) for the year 2007 provided by the Health Ministry. Patients: This includes the total number of patients who required treatment in all national hospitals for 5 DRG: 115 - bradyarrhythmic complication during the acute coronary syndrome, heart failure or shock; 116 -symptomatic isolated conduction defects; 117 -revisions, but without changing the battery, 118- application of a new one, 549 - implementation or revision but with serious complications. Principal variables of interest: demographic, clinical (number of secondary diagnoses (NSD) and procedures (NP), mortality) and management (total and preoperative length of stay (LOS), access, discharge, hospital size), defining inefficient stays as those exceeding 2 days on the average. Results: 23,154 episodes, 5.3% small hospitals. The comparative bivariate study between small hospitals and the rest, not discriminated by DRG, showed a mean LOS of 7.87±8.78 days vs 11.01±12.95 (p=0.005, 95% CI for mean difference [0.17, 1.65]) and also lower than preoperatively (3.62±6.14 vs. 4.22±6.68 days (p=0.015)) without greater comorbidity, as measured by proxy through the NSD (5.23±2.88 vs 5.42±3.28 (p=0.055)) and NP as proxy of diagnostic and therapeutic effort (3.79±2.50 vs 3.55±2.69 (p=0.002)). A total of 24.1% were inefficient, there being an association with preoperative stay, NDS, NP and emergency access. Conclusion: Pacemaker implantation and generator change in small hospitals is more efficient, with internal consistency by subgroups.

E., Moreno-Millán; J.M., García-Torrecillas; J., Villegas-del Ojo; F., Prieto-Valderrey.

2011-03-01

290

Impact of different dose distribution of 125I seeds interstitial brachytherapy on the effects in human gastric carcinoma bearing nude mice  

International Nuclear Information System (INIS)

Objective: 125I seeds interstitial brachytherapy has been clinically used for years. How- ever, how the dose distribution affects the therapeutic response remains to be elucidated. The present study was undertaken to investigate the impact of different dose distribution on the effects of 125I seeds interstitial brachytherapy. Methods: Thirty-two human gastric carcinoma bearing nude mice were randomly divided in- to three treated groups and one control group with eight mice in each group. 125I seeds were implanted in the treated groups with the same total activity (33.30 MBq). Based on the dose distribution and activity of single seed, the treated groups were classified to high activity group (33.30 MBq x 1), moderate activity group (16.65 MBq x 2) and low activity group (11.10 MBq x 3). The control group was implanted radioactivity-free seeds. The evaluation parameters were obtained after 30 d, which included survival rate, body weight, volume inhibitory rate, histological tumor regression and regional skin reaction. Analysis of variance and Kruskal-Wallis H test were used for data statistical analysis. Results: All mice survived during the observation period. There was no significant difference of the body weight among the groups after 125I seeds implantation (F=2.23, P>0.05). The volume inhibitory rates in high, moderate and low activity groups were 92.47%, 97.15% and 89.01%, respectively. After treatment the average tumorctively. After treatment the average tumor volume was (138.85 ± 16.45) mm3 in high activity group, (52.52 ± 30.54) mm3 in moderate activity group, (202.72 ± 126.97) mm3 in low activity group and (1843.99 ± 447.63) mm3 in control group. In all treated groups, the average tumor volume was significantly smaller than that in control group (t=3.092, 3.376, 3.269, all P125I seed and the dose distribution may exert critical impact on the therapeutic effects and radiation injury in 125I seeds interstitial brachytherapy. (authors)

291

Relationship between isotope half-life and prostatic edema for optimal prostate dose coverage in permanent seed implants.  

Science.gov (United States)

The robustness of treatment planning to prostatic edema for three different isotopes (125I, 103Pd, and 131Cs) is explored using dynamical dose calculations on 25 different clinical prostate cases. The treatment plans were made using the inverse planning by simulated annealing (IPSA) algorithm. The prescription was 144, 127, and 125 Gy for 125I, 131Cs, and 103Pd, respectively. For each isotope, three dose distribution schemes were used to impose different protection levels to the urethra: V120 = 0%, V150 = 0%, and V150 = 30%. Eleven initial edema values were considered ranging from 1.0 (no edema) to 2.0 (100%). The edema was assumed to resolve exponentially with time. The prostate volume, seed positions, and seed activity were dynamically tracked to produce the final dose distribution. Edema decay half-lives of 10, 30, and 50 days were used. A total of 675 dynamical calculations were performed for each initial edema value. For the 125I isotope, limiting the urethra V120 to 0% leads to a prostate D90 under 140 Gy for initial edema values above 1.5. Planning with urethra V150 at 0% provides a good response to the edema; the prostate D90 remains higher than 140 Gy for edema values up to 1.8 and a half-life of 30 days or less. For 103Pd, the prostate D90 is under 97% of the prescription dose for approximately 66%, 40%, and 30% of edema values for urethra V120 = 0%, V150 = 0%, and V150 = 30%, respectively. Similar behavior is seen for 131Cs and the center of the prostate becomes "cold" for almost all edema scenarios. The magnitude of the edema following prostate brachytherapy, as well as the half-life of the isotope used and that of the edema resorption, all have important impacts on the dose distribution. The 125I isotope with its longer half-life is more robust to prostatic edema. Setting up good planning objectives can provide an adequate compromise between organ doses and robustness. This is even more important since seed misplacements will contribute to further degrade dose coverage. PMID:18561673

Villeneuve, Maxime; Leclerc, Ghyslain; Lessard, Etienne; Pouliot, Jean; Beaulieu, Luc

2008-05-01

292

Relationship between isotope half-life and prostatic edema for optimal prostate dose coverage in permanent seed implants  

International Nuclear Information System (INIS)

The robustness of treatment planning to prostatic edema for three different isotopes (125I, 103Pd, and 131Cs) is explored using dynamical dose calculations on 25 different clinical prostate cases. The treatment plans were made using the inverse planning by simulated annealing (IPSA) algorithm. The prescription was 144, 127, and 125 Gy for 125I, 131Cs, and 103Pd, respectively. For each isotope, three dose distribution schemes were used to impose different protection levels to the urethra: V120=0%, V150=0%, and V150=30%. Eleven initial edema values were considered ranging from 1.0 (no edema) to 2.0 (100%). The edema was assumed to resolve exponentially with time. The prostate volume, seed positions, and seed activity were dynamically tracked to produce the final dose distribution. Edema decay half-lives of 10, 30, and 50 days were used. A total of 675 dynamical calculations were performed for each initial edema value. For the 125I isotope, limiting the urethra V120 to 0% leads to a prostate D90 under 140 Gy for initial edema values above 1.5. Planning with urethra V150 at 0% provides a good response to the edema; the prostate D90 remains higher than 140 Gy for edema values up to 1.8 and a half-life of 30 days or less. For 103Pd, the prostate D90 is under 97% of the prescription dose for approximat7% of the prescription dose for approximately 66%, 40%, and 30% of edema values for urethra V120=0%, V150=0%, and V150=30%, respectively. Similar behavior is seen for 131Cs and the center of the prostate becomes 'cold' for almost all edema scenarios. The magnitude of the edema following prostate brachytherapy, as well as the half-life of the isotope used and that of the edema resorption, all have important impacts on the dose distribution. The 125I isotope with its longer half-life is more robust to prostatic edema. Setting up good planning objectives can provide an adequate compromise between organ doses and robustness. This is even more important since seed misplacements will contribute to further degrade dose coverage

293

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

International Nuclear Information System (INIS)

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

294

Usefulness of nano-zirconia for purification and concentration of 125I solution for medical applications  

International Nuclear Information System (INIS)

This paper described the utility of tetragonal nano-zirconia (t-ZrO2) to remove trace levels of 134Cs and 137Cs contaminants from 125I solution obtained from neutron irradiation of natural Xe target. A careful scrutiny of the adsorption parameters of t-ZrO2 was considered worthwhile investigating to arrive at the optimum conditions to perform the purification as well as concentration of 125I solution. The procedure proposed herein provides 125I of acceptable purity and radioactive concentration for clinical application. The compatibility of the separated product in the preparation of 125I brachytherapy sources was found to be satisfactory. - Highlights: • Utility of nano-zirconia sorbent for purification and concentration of 125I is proposed. • The process was demonstrated up to 3.7 GBq (100 mCi) activity level. • Radiocesium impurities could be completely removed from the 125I solution. • Greater than 10 fold increase in the radioactive concentration of 125I was achieved. • Iodine-125 obtained was found suitable for preparation of brachytherapy sources

295

The distribution of 125I-metrizamide and 125I-diatrizoate between blood, brain and cerebrospinal fluid in the rabbit  

International Nuclear Information System (INIS)

The entry of 125I-metrizamide and of 125I-diatrizoate from blood into brain has been studied in rabbits. The blood-brain barrier is very tight to both molecules, all cerebral regions having spaces between 0.5 and 2% after maintenance of constant blood levels for 4 h. In extraneural tissues both compounds appear to distribute in extracellular fluid except for accumulation of metrizamide by the liver and perhaps the small intestine. Profiles of radioactivity through cerebral gray matter have been obtained following ventriculocisternal perfusion of artificial cerebrospinal fluid containing 125I-metrizamide. The nature of these profiles and their behaviour with time suggest that metrizamide passes through gray matter by simple diffusion, that it is largely distributed in the extracellular fluid and that back movement across the blood-brain barrier is small. (orig.)

296

Comparative affinities of human adrenomedullin for 125I-labelled human alpha calcitonin gene related peptide ([125I]hCGRP alpha) and 125I-labelled Bolton-Hunter rat amylin ([125I]BHrAMY) specific binding sites in the rat brain.  

Science.gov (United States)

Adrenomedullin (ADM) is a recently identified peptide that shows some homology (approximately 25%) with calcitonin gene related peptide (CGRP) and is now considered to be a new member of this peptide family. Because it shares biological effects with CGRP, we evaluated the possible affinity of human adrenomedullin (hADM) for 125I-labelled human CGRP alpha ([125I]hCGRP alpha) binding sites in the rat brain. Moreover, we evaluated the potential existence of cross-reactivity for 125I-labelled Bolton-Hunter rat amylin ([125I]BHrAMY), another member of this peptide family. In all brain areas investigated, hADM only competed with relatively low affinities for both [125I]hCGRP alpha and [125I]BHrAMY binding sites, with IC50 values generally in the high nanomolar-low micromolar range, the lowest affinity being observed for [125I]BHrAMY binding sites. Interestingly, the lowest affinities of hADM against both radioligands were detected in the nucleus accumbens and ventral striatum. These areas are known to be enriched with atypical CGRP - salmon calcitonin - amylin sensitive sites. It thus appears that hADM is unlikely to bind to this atypical site. Moreover, hADM demonstrated limited affinity for either [125I]hCGRP alpha or [125I]BHrAMY binding sites in the rat brain. This suggests that the potential biological effects of ADM in the brain could be mediated through a different class of receptors with higher affinity for this newly isolated peptide. PMID:8846406

van Rossum, D; Ménard, D P; Chang, J K; Quirion, R

1995-07-01

297

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

International Nuclear Information System (INIS)

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

298

inhibition effects of 125I-UdR on the growth of HepG2 cells  

International Nuclear Information System (INIS)

Objective: To determine the inhibition effects of 125I-UdR on the growth of human hepatoma cell line HepG2 and the influencing factors. Methods: 125I-UdR was added to the HepG2 culture medium. The amount of 125I-UdR uptake by HepG2 cells was evaluated through measuring the radioactivity per cell; the inhibiting effects of 125I-UdR on HepG2 growth were estimated by clonal forming method. Results: The amounts of 125I-UdR uptaken by HepG2 increased with the dose of 125I-UdR escalating in the culture medium (r=0.99). The uptake of 125I-UdR by HepG2 cells was higher than that of Na125I. As the 125I-UdR concentration in HepG2 escalating, the inhibition effects became stronger (r=-0.943) and the LD50 was (0.87 +- 0.29) kBq/mL. The survival fraction of 125I-UdR group was significantly lower than that of Na125I group. Conclusions: The inhibition effects of 125I-UdR on HepG2 cell growth were obvious. 125I-UdR may be incorporated inside the HepG2 cells and the uptake of HepG2 was dose dependent

299

Morbimortalidad de la endocarditis infecciosa asociada a dispositivos electrónicos implantables permanentes / Morbimortality of infective endocarditis associated with permanent cardiovascular implantable electronic devices  

Scientific Electronic Library Online (English)

Full Text Available La endocarditis infecciosa (EI) asociada a dispositivos electrónicos implantables permanentes (DEIP) es una complicación de baja frecuencia pero alta mortalidad sin el tratamiento adecuado. El avance sobre el conocimiento de esta patología y el desarrollo de estrategias terapéuticas como el diagnóst [...] ico precoz, manejo de antibióticos, técnicas de extracción, entre otras, han mejorado el pronóstico de estos pacientes. Los objetivos de este estudio fueron evaluar la morbimortalidad intrahospitalaria y alejada y analizar algunos factores que justifican las diferencias con los datos de la mortalidad publicada. Se estudiaron en forma retrospectiva pacientes entre marzo/2002 y marzo/2011 con diagnóstico de EI asociada a DEIP. Se analizaron características basales, diagnósticas, terapéuticas, evolución intrahospitalaria y alejada. Se incluyeron 26 casos atendidos en nuestro hospital, 23 de los cuales fueron remitidos desde otros centros para su diagnóstico y tratamiento. La edad promedio fue de 67,5 años. Todos los pacientes recibieron antibióticos durante seis semanas y se les retiró el sistema en forma completa; en el 95% de los pacientes por vía percutánea y en 2 pacientes se requirió estereotomía mediana, atriotomía y colocación de marcapasos epicardíaco. La mortalidad fue del 4% y en el seguimiento fue nula. La morbilidad intrahospitalaria fue del 31%. En el seguimiento alejado no hubo reinfecciones u otra complicación. Como conclusión la EI es un cuadro grave que presenta una morbilidad elevada con estadías hospitalarias prolongadas, pero la mortalidad es baja. La explicación podría estar en las técnicas percutáneas, experiencia, extracción completa, el tiempo del reimplante del nuevo dispositivo y el tratamiento precoz, entre otros factores. Abstract in english Infective endocarditis (IE) associated with permanent cardiovascular implantable electronic devices (CIEDs) is a complication of low frequency, but high mortality without adequate treatment. Progress on the knowledge of this disease and the development of therapeutic strategies such as early diagnos [...] is, antibiotic management and better extraction techniques, among others, have improved the prognosis of these patients. The objectives of this study were to evaluate the in-hospital and out-of-hospital morbidity, and analyze some factors that explain the differences among the published mortality data. Patients diagnosed with IE associated with CIEDs were studied, retrospectively, between March/2002 and March/2011. We analyzed baseline, diagnostic and therapeutic characteristics, and in-hospital and out-of-hospital courses of the disease. We included 26 cases treated in our hospital, 23 of whom were referred from other centers for diagnosis and treatment. The average age of the patients was 67.5 years. All patients received antibiotics for six weeks and underwent complete removal of the device system, in 95% of patients by percutaneous extraction and 2 patients required a median sternotomy, atriotomy and epicardial pacemaker placement. Mortality was 4% and the follow up mortality was zero. The in-hospital morbidity was 31%. In the follow-ups there were no reinfections or other complications. In conclusion, IE is a serious condition that has a high morbidity with prolonged hospital stays, but with a low mortality. The explanation may lie in the use percutaneous extraction techniques, experience, complete extraction of the device system, the time of reimplantation of the new device and early treatment, among other factors.

Gabriel, Pérez-Baztarrica; Flavio, Salvaggio; Norberto, Blanco; Héctor, Mazzetti; Ricardo, Levin; Alejandro, Botbol; Rafael, Porcile.

2013-12-01

300

Exploration of dopamine transporter and D2 receptors in morphine dependent rats through 125I-?-CTT, 125I-IBZM cerebral autoradiography and the biodistribution study  

International Nuclear Information System (INIS)

Objective: To explore the variation of cerebral dopamine (DA) transmitting system in morphine dependent (MD) rats using dopamine transporter (DAT) and D2 receptors imaging agent. Methods: MD model rats were established by using a two-compartment (C1 and C2-morphine conditioned compartment) apparatus for assessing morphine conditioned place preferences in rats. 125I-2?-carbomethoxy-3?-(4-iodophenyl) tropane (125I-?-CIT) and 125I-3-iodo-2-hydroxy-6-methoxy-N[(1-ethyl-2-pyrrolidinyl) methyl] benzamide (125I-IBZM) cerebral DAT and D2 receptor autoradiography and biodistribution study were used to evaluate the variation of DAT and D2 receptors in morphine dependent rats. Results: The mean time of MD rats entering from C1 to C2 was (0.84 +- 0.50) min after 6 days' conditioned place preference training, shorter than that of the control group [(2.40 +- 1.10) min, P 125I-?-CIT uptake ratio of striatum (ST)/cerebellum (CB) and nucleus acumens (NAC)/CB in MD group were 4.76 +- 0.92 and 2.72 +- 0.96, significantly lower than that of control group (5.92 +- 0.67 and 4.16 +- 0.56, P 125I-IBZM uptake ratio in MD group were 4.11 +- 0.56 and 2.64 +- 0.25, lower than that in control group (5.43 +- 0.74 and 3.49 +- 0.65, P 125I-?-CIT, 125I-IBZM biodistribution study also sp>I-IBZM biodistribution study also showed that the DAT and D2 binding sites were reduced in ST of MD group by (21.68 +- 11.11)% and (18.69 +- 9.97)% comparing to the controls, respectively. Conclusions: The DAT and D2 receptors in both ST and NAC were all involved and reduced to some extent in morphine dependent model rats, the DAT and D2 receptor imaging agent could reflect the variation of DAT and D2receptors, this would afford the theoretical basis for D2 receptors and DAT imaging in study on preventing drug addiction and on its abstinence

301

Labelling of ochratoxins with sup 3 H or sup 125 I  

Energy Technology Data Exchange (ETDEWEB)

Catalytic hydrogenation of ochratoxin A by carrier-free tritium was used to prepare {sup 3}H-ochratoxin B with a high specific activity. Iodination of ochratoxin B by carrier-free Na {sup 125}I using the chloramine method yielded {sup 125}I-ochratoxin with a high specific activity. Another {sup 125}I-derivative of ochratoxin A was prepared by iodination of an ochratoxin A - L-tyrosine-methylester conjugate. All three radioactive preparations were found to be useful for radioimmunoassay. (author).

Schmiedova, D.; Veres, K.; Cerny, B. (Ceskoslovenska Akademie Ved, Prague (Czechoslovakia). Ustav Nuklearni Biologie a Radiochemie); Ruprich, J. (Institut Hygieny a Epidemiologie, Prague (Czechoslovakia)); Nemecek, J. (Slovak Academy of Sciences, Prague (Czechoslovakia). Inst. of Microbiology)

1989-01-01

302

Labeling of IgG molecules with 125I  

International Nuclear Information System (INIS)

Full text: Limiting Chloramine-T Method. Chloramine-T in aqueous solutions is rapidly decomposed when present in very low concentrations. Most techniques recommend the use of 0.5 - 1.0 mg/ml of reagent. Of this a small amount is used for labeling (for instance 10 ?l solution corresponding to 50-100 ?g reagent). Limiting chloramine-T method uses 1.2 ?g reagent and thus the solution is by far more unstable. The methodology is based on the use of a very small amount of Chloramine-T and leave the reaction to proceed until total exhaustion of the oxidant. A stock solution is prepared fresh at the moment to start labeling and a dilution is performed to get the correct amount of reagent into labeling vial. 150 mg Chloramine-T are dissolved with 5 ml freshly distilled water. Stock concentration is 30 mg/ml. It must be used immediately. Just before use 0.1 ml (3 mg) of this stock are diluted 1 in 250 with phosphate buffer 0.05 M and 10 ?l are added to the labeling vial where the IgG, concentrated buffer and activity have been added already. IgG molecules (most monoclonal antibodies) in phosphate buffer 0.05 M pH 7.4 or glycerol: phosphate 1:1 in 10-50 ?g amount per 10-50 ?g amount per 10-50 ?l are pipetted into an eppendorf tube (capacity 1.5 ml). 10-15 ?l of phosphate buffer 0.5 M pH 7.5. Approximately 500 ? Ci 125I are added. 10 ?l (containing 1.2 ?g) of diluted solution of Chloramine-T in phosphate buffer. Mix by gentle agitation during a couple of minutes. Determine labeling yield by nonspecific precipitation of proteins with trichloroacetic acid solution 20% concentration (TCA). Take a 1 ?l aliquot and mix it with 100 ?l of bovine serum albumin solution 5% into an eppendorf tube. Add 0.9 ml TCA, cup the tube and vortex mix. Centrifuge 3-5 minutes at 3000 rpm. Eppendorf Minifuges are recommended. For an immunoglobulin (150.000 dalton) the activity needed to get an incorporation of 1 atom iodine per IgG molecule with a 50% yield is approximately 300 ?Ci. An excess iodine is added to be sure the reaction proceeds correctly. If yield is lower than expected, another aliquot of freshly prepared chloramine-T solution may be prepared and added following the same steps as before. Determine yield by TCA method again. Purification of labeled molecule by gel-permeation with Sephadex G-25 prepackaged columns Pharmacia PD-10 using PBS-BSA 0.2% as eluent and collecting 0.5 ml fractions. Labeled IgG is recovered in fraction 6 to 8 and iodine is seen at fraction 13 to 18

303

Experimental study on differential diagnosis of tumor from inflammation by using /sup 125/I labeled Pisum sativum agglutinin  

Energy Technology Data Exchange (ETDEWEB)

We have reported that Pisum sativum agglutinin (PSA), a plant lectin which recognizes mannosyl residues, accumulates markedly in Ehrlich solid tumor (EST) and suggested the possibility of applying PSA to tumor imaging radiopharmaceuticals. In the present work, an inflammation was induced by implantation of cotton thread in the left rear leg skeletal muscle of ddY mice and Ehrlich ascites tumor cells were inoculated into the right rear leg. /sup 67/Ga-citrate accumulated in the tumor tissue and the inflammatory lesion to almost equal extents. On the other hand, /sup 125/I-PSA preferentially accumulated in tumor tissues in mice bearing both tumor and inflammation. The results suggest that differential diagnosis of tumor from inflammation using radiolabeled PSA may be possible.

Kojima, Shuji; Jay, M.

1987-12-01

304

An experimental study on differential diagnosis of tumor from inflammation by using 125I labeled Pisum sativum agglutinin  

International Nuclear Information System (INIS)

We have reported that Pisum sativum agglutinin (PSA), a plant lectin which recognizes mannosyl residues, accumulates markedly in Ehrlich solid tumor (EST) and suggested the possibility of applying PSA to tumor imaging radiopharmaceuticals. In the present work, an inflammation was induced by implantation of cotton thread in the left rear leg skeletal muscle of ddY mice and Ehrlich ascites tumor cells were inoculated into the right rear leg. 67Ga-citrate accumulated in the tumor tissue and the inflammatory lesion to almost equal extents. On the other hand, 125I-PSA preferentially accumulated in tumor tissues in mice bearing both tumor and inflammation. The results suggest that differential diagnosis of tumor from inflammation using radiolabeled PSA may be possible. (orig.)

305

Bioevaluation studies of 125I-Bakuchiol in tumor bearing animals  

International Nuclear Information System (INIS)

Bakuchiol, a meroterpene phenol is abundant in seeds and leaves of the plant Psoralea corylifolia. Bakuchiol is widely used in Indian as well as Chinese medicine to treat a variety of diseases and possesses anti-tumor, anti-bacterial, cytotoxic and anti-helmenthic properties. The cytotoxicity of bakuchiol is mainly due to its DNA polymerase 1 inhibiting activity. 125I, an auger electron emitter is an effective radiotherapeutic agent when targeted close to DNA. The incorporation of 125I in bakuchiol might augment its cytotoxic activity is envisaged and had reported the radiolabelling of bakuchiol with 125I and its in vitro evaluation in lymphosarcoma and lymphoma. The current paper describes the in vitro and in vivo evaluation of 125I-bakuchiol in fibrosarcoma cells

306

In vitro cell-mediated immunity assay using 125I-iododeoxyuridine  

International Nuclear Information System (INIS)

We investigated an in vitro cell-mediated immunity assay using incorporation of 125I-iododeoxyuridine as an indicator of lymphocyte responsiveness to mitogen stimulation. The system permits the use of whole-blood cultures in rats and dogs

307

Preparation and characterization of 125I-labelled proinsulin for radioimmunoassay (Preprint No. CT-62)  

International Nuclear Information System (INIS)

Bovine proinsulin is iodinated with 125I. The labelled proinsulin was purified over sephadex. The preparation was characterized for stability and immunoreactivity. A radioimmunoassay was standardized using this labelled preparation. (author)

308

Measurements of the effects of 'thyroid blocking' in patients investigated with 125I-fibrinogen  

International Nuclear Information System (INIS)

The diagnosis of venous thromboses with around 4 MBq of 125I-labelled fibrinogen is a routine investigation. At the degradation of the 125I-fibrinogen, 125I is released and is available for thyroid uptake. The biological half-life of fibrinogen is around four days. In Swedish hospitals it has been found that a thyroid blocking agent using 300 mg KI daily for 10-12 days after injection of 125I-fibrinogen gives a very efficient reduction of the thyroid uptake. After cessation of the blocking, the uptake increases. Studies of the effect of longer blocking periods with smaller daily amounts of KI are in progress. (U.K.)

309

Radioiodination of ibuprofen with 125I and its biological behavior in mice  

International Nuclear Information System (INIS)

A procedure for radioiodination of Ibuprofen with iodine-125 is carried out via an electrophilic substitution reaction. The reaction parameters were studied Ibuprofen concentration, pH of the reaction mixture, reaction time temperature, and different oxidizing agents to optimize the conditions for the labeling of Ibuprofen to abstain a high radiochemical yield of 125I-Ibuprofen (125I-Ib up). Using 3.7 MBq of of Na 125I, 100?g of ibuprofen as substrate and 100?g of iodogen as oxidizing agent in ethanol at 60 OC for 10 min, a maximum radiochemical yield of 125I-Ib up (78%) was obtained. The labeled compound was separated and purified from inactive Ibuprofen by means of high-pressure liquid chromatography (HPLC). The biological distribution in normal and inflamed mice indicates the suitability of radioiodinated Ibuprofen for imaging of inflammation only induced with turpentine oil. (Author)

310

Proteolytic activity of beef liver determined by natural 125I-labelled substrates  

International Nuclear Information System (INIS)

The method of determining the enzymatic activity of acid proteinases is described. The method is based on the use of 125I-labelled natural protein substrates. 125I-labelled albumin, 125I-globulin and 125I-insulin were tested for the determination of activities. All the substrates were hydrolyzed with the enzymes of the supernatant fraction (106,000 g) of beef liver homogenate in the acid pH zone. Optimum enzymatic reaction conditions were tested, the dependence of the reaction on the enzyme concentration, time and temperature was determined, pH optimum was ascertained for the individual substrates, and pH stability was determined. The results show that the method is suitable for determining the enzymatic activity of proteinases of cathepsin character. (author)

311

Distribution and levels of [125I]IGF-I, [125I]IGF-II and [125I]insulin receptor binding sites in the hippocampus of aged memory-unimpaired and -impaired rats  

International Nuclear Information System (INIS)

The insulin-like growth factors (IGF-I and IGF-II) and insulin are localized within distinct brain regions and their respective functions are mediated by specific membrane receptors. High densities of binding sites for these growth factors are discretely and differentially distributed throughout the brain, with prominent levels localized to the hippocampal formation. IGFs and insulin, in addition to their growth promoting actions, are considered to play important roles in the development and maintenance of normal cell functions throughout life. We compared the anatomical distribution and levels of IGF and insulin receptors in young (five month) and aged (25 month) memory-impaired and memory-unimpaired male Long-Evans rats as determined in the Morris water maze task in order to determine if alterations in IGF and insulin activity may be related to the emergence of cognitive deficits in the aged memory-impaired rat. In the hippocampus, [125I]IGF-I receptors are concentrated primarily in the dentate gyrus (DG) and the CA3 sub-field while high amounts of [125I]IGF-II binding sites are localized to the pyramidal cell layer, and the granular cell layer of the DG. [125I]insulin binding sites are mostly found in the molecular layer of the DG and the CA1 sub-field. No significant differences were found in [125I]IGF-I, [125I]IGF-II or [125I]insulin binding levels in any regions or laminae of the hippocampus of yoegions or laminae of the hippocampus of young vs aged rats, and deficits in cognitive performance did not relate to altered levels of these receptors in aged memory-impaired vs aged memory-unimpaired rats. Other regions, including various cortical areas, were also examined and failed to reveal any significant differences between the three groups studied.It thus appears that IGF-I, IGF-II and insulin receptor sites are not markedly altered during the normal ageing process in the Long-Evans rat, in spite of significant learning deficits in a sub-group (memory-impaired) of aged animals. Hence, recently reported changes in IGF-I receptor messenger RNA levels in aged memory-impaired rats [42] are apparently not reflected at the level of the translated protein. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

312

Feasibility study of 125I brachytherapy in Indonesia  

International Nuclear Information System (INIS)

Cancer is a term for diseases in which abnormal cells divide without control. Many cancer treatments such as chemotherapy or immunotherapy, as well as radiotherapy, are intended to kill tumor cells. Brachytherapy can be performed by using tiny titanium cylinders which contain a small amount of radioactive material such as radioisotopes I1'25. These seeds are used as implants for prostate cancer or breast cancer. This Study is to develop and produce innovative radioisotopic products as brachytherapy seeds. Research reactor in Serpong Indonesia has been producing radioisotopes I125 from the mid year 2005 through 4 time irradiation. From these radioisotopes the research would continue to produce I125 brachystherapy. This study is focused on the technology producing of I125 brachystherapy production, for Indonesian people who has a cancer. (author)

313

Determination of 125I and 131I in the presence of inorganic salts  

International Nuclear Information System (INIS)

Variations in the salt concentration (KBr, CsCl or CsBr) of samples labelled with 125I, or with 125I and 131I together, lead to counting attenuations as high as 60% when measuring radioactivity. In order to overcome this attenuation problem without having to eliminate the salts, one may either dilute the samples, when feasible, or develop correction curves relating counting efficiency to salt concentration. (author)

314

Molecular characterization of 125I decay and X-ray-induced HPRT mutants in CHO cells  

International Nuclear Information System (INIS)

The predominant initial lesion induced by 125I decay in DNA is a double-strand DNA break comprising a 'mini deletion' of up to several base pairs (bp). However, Southern analysis of the structure of 125I decay-induced HPRT mutants in Chinese hamster ovary cells revealed that most of the mutants are deletions of thousands of bps. A similar predominance of substantial deletions was also found in X-ray-induced mutants. (author)

315

Purification of monoiodinated vasointestinal peptide (M125I-VIP) by high pressure liquid chromatography (HPLC)  

International Nuclear Information System (INIS)

In our developed reverse phase high performance liquid chromatography, four forms of M125I-VIP have been isolated free from unlabeled VIP and other iodinated components. The quicker eluting M125I-VIP forms (oxidised and reduced) have a consistently and significantly low non-specific binding with specific target cells of VIP (HT-29) as compared to the late eluting forms of VIP. The retention time is considerably increased when the molecule of VIP is fully iodinated

316

Preparation and isolation of a homogeneous 125I-cortisol derivative  

International Nuclear Information System (INIS)

Tracer specificity plays an important role in the radioimmunoassay (RIA) of steroid hormones. In this paper, we describe the preparation and purification of 125I-labeled cortisol derivative with a carboxymethyloxime-histamine bridge. The investigation on the method of purification showed that HPLC could be adopted for the routine preparation of a pure, homogeneous tracer. The retention time observed in HPLC for 125I-histamine-CMO-cortisol conjugate could be used as an index for qualitative and quantitative assessments. (author)

317

Inhibition effects of 125I-triplex forming oligonucleotide to hepatoma cells  

International Nuclear Information System (INIS)

Objective: Triplex forming oligonucleotide (TFO) has been reported as a new antigene strategy. The purpose of this study was to observe the inhibition effects of 125I-TFO on hepatoma cells and to investigate the possibility of using 125I-TFO as an antigene radiotherapy technique for hepatocellular carcinoma (HCC) related to HBV. Methods: TFO complementary to the initiator of S gene of HBV was synthesized and labeled with 125I. HepG2.2.15 cells, in which HBV genome was integrated, were incubated with 125I-TFO, TFO and 125I respectively. After incubation, hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) of each group were assayed with ELISA and the survival rate of cells in each group was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTT) reduction assay. Results: 125I-TFO showed a high stability with a radiolabeling rate of >93%. The radiochemical purity of labeled compound was 90.8%, 81.1% and 73.2% respectively after 12, 48 and 72 h at 37 degree C. The peak inhibition effect of 125I-TFO on synthesizing HBsAg and HBeAg by HepG2.2.15 cells were found at 48 h after transfection, with significantly the highest inhibition rate of 45.2% for HBsAg and 74.5% for HBeAg expression among the three groups(P125I-TFO may inhibit the antigen expressisup>I-TFO may inhibit the antigen expression of HBV and the growth of hepatocarcinoma cells, thus it may provide a new approach to develop gene-based radiotherapeutic pharmaceuticals for anti-HBV and HCC. (authors)

318

Intracellular modification of 125I-labeled epidermal growth factor by normal human foreskin fibroblasts  

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

319

Heparin blocks 125I-calmodulin internalization by isolated rat renal brush border membrane vesicles  

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

320

Separation of 125I from radioactive waste with anion-exchange membrane treated with trimethylhydroxypropylamino group  

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The membrane characteristics controlling 125I and 36Cl transport across anion exchange paper membranes are examined using four different ion exchange capacities paper membranes treated with trimethylhydroxypropylamino group. Non-equilibrium thermodynamic analyses for the paper membrane transport process are carried out based on transmembrane potential, membrane conductance, and ion flux measurements. The electroconductive membrane, permeabilities representing the solution/membrane ion distribution due to electrostatic effects, and the diffusional membrane permeabilities, representing the migration speed of ions within the membrane phase, for 125I are higher than those for 36Cl in all cases. In the paper membrane treated with trimethylhydroxypropylamino group, 125I diffusion or 125I solution/membrane distribution process can be improved by increasing the concentration of anion exchange sites in the paper membrane. These findings indicate the potential utility of paper membranes prepared in this way for separating 125I from radioactive waste that has been contaminated with chloride ions. The 125I transport performance of such systems may be improved with the use of other anion-exchange groups. (author)

321

Radiolabeling of EGCG with 125I and its biodistribution in mice  

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The aim of the present study was to label EGCG with 125I and to determine its radiopharmaceutical potential in mice. EGCG was labeled with 125I using the iodogen method. The labeling yield and the radiochemical purity of 125I-EGCG were determined by radio thin-layer chromatography (RTLC). The Labeling yield was approximately 89.4 %. The radiochemical purity was approximately 96.4 %. The biodistribution studies of the labeled compound (specific activity; 0.47 TBq/?g) were performed in male Kunming mice. The uptakes of 125I-EGCG in some organs were determined at different time after injection to the mice. The radioactivity in each organ was counted and the percentage of injected activity per gram of tissue weight (%ID/g) for each organ and blood was calculated. Incorporation of radioactivity in the various tissue/organ was confirmed by microautoradiography. 125I-EGCG uptake in the stomach and salivary gland was higher than other organ/tissue. The black silver grains was concentrated in the nucleus, cytoplasm, intercellular substance and capillaries of that various organs, and its unevenly distributed. Thus, 125I-EGCG may be radiopharmaceutical for the imaging of the stomach and salivary gland. (author)

322

Plasmid DNA breakage by decay of DNA associated isotopes 123I and 125I  

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The biological consequences of decay of DNA-associated 125I have been extensively investigated using a variety of systems. It is well established that decay of the isotope in close proximity to DNA produces a DSB with an efficiency close to 1. Much less information is available for another iodine isotope - 123I. It is a 'weaker' Auger emitter than 125I, and has much shorter half-life; 13.2 hours compared to 60 days for 125I. Cell culture studies indicate that decay of 123I is more than two times less efficient in killing V79 cells than decay of 125I, and produces from 0.45 to 0.74 DSB per decay in the cell nucleus. The Monte Carlo simulation of 123I decay and DSB induction has generated a value of 0.4 DSB per decay of incorporated isotope. We have adapted the plasmid DNA assay to compare strand breakage by decay of DNA-associated 125I and 125I, exploiting DNA minor groove binding ligand Hoechst 33258 labelled with either of these isotopes. Application of the plasmid assay to this study highlighted a range of important factors, which were taken into account to ensure a valid outcome. These factors involve the statistical implications of the nature of the breakage events (such as multiple breaks arising from a single decay event), two different sources of damage, namely internal (from DNA-associated decay events) and external (from decays occurring anywhere in solution), a decays occurring anywhere in solution), and consideration of the fraction of DNA-bound ligand. In our experiments, we incubated pBR322 plasmid with [125I]-iodoHoechst 33258 or with mixture of ligands labelled with 123I and 125I. The latter approach allows measurement of the ratio of probabilities of DSB formation per decay for the two isotopes, with much higher precision than determination of the individual breakage probabilities for each isotope. We obtained for the probability (per decay) of induction of DSB by the 125I-labeled ligand a value of 0.82 ± 0.05. Inclusion of DMSO as a radical scavenger, reduces this value to 0.65 ± 0.05 DSB per decay. The ratio of DSB probability per decay of 123I to that of 125I is 0.63 ± 0.03, with little change with inclusion of DMSO; namely to 0.65 ± 0.03

323

DNA strand breakage by 125I-decay in oligoDNA  

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Full text: A double-stranded oligodeoxynucleotide containing 125I-dC in a defined location, with 5'- or 3'-32P-end-labelling of either strand, was used to investigate DNA strand breakage resulting from 125I decay. Samples of the 32P-end-labelled and 125I-dC containing oligoDNA were incubated in 20 mM phosphate buffer (PB), or PB + 2 M dimethylsulphoxide (DMSO) at 4 deg during 18-20 days. The 32P-end-labelled DNA fragments produced by 125I decays were separated on denaturing polyacrylamide gels, and the 3P activity in each fragment was determined by scintillation counting after elution from the gel. The fragment size distribution was then converted to a distribution of single stranded break probabilities at each nucleotide position. The results indicate that each 125I decay event produces at least one break in the 125I-dC containing strand, and causes breakage of the opposite strand in 75-80% of events. Thus, the double stranded break is produced by 125I decay with probability ?0.8. Most of single stranded breaks (around 90%) occurred within 5-6 nucleotides of the 125I-dC, however DNA breaks were detected up to 18-20 nucleotides from the decay site. The average numbers of single stranded breaks per decay are 3.7 (PB) and 3.3 (PB+DMSO) in 125I-dC containing strand, and 1.5 (PB) and 1.3 (PB+DMSO) in the opposite strand. Deconvolution of strand break probabilities as a function of separation from the 125I, in terms of both distance (to target deoxyribosyl carbon atoms, in B-DNA) and nucleotide number, show that the latter is an important parameter for the shorter-range damage. This could indicate a role for attenuation/dissipation of damage through the stacked bases. In summary, the results represent a much more extensive set of data than available from earlier experiments on DNA breakage from l25I-decay, and may provide new mechanistic insights

324

Targeted radiotherapy of multicell neuroblastoma spheroids with high specific activity [125I]meta-iodobenzylguanidine  

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Purpose: Iodine-125 induces cell death by a mechanism similar to that of high linear energy transfer (high-LET) radiation. This study investigates the cytotoxicity of high-specific-activity [125I]meta-iodobenzylguanidine (125I-mIBG) in human SK-N-MC neuroblastoma cells grown as three-dimensional multicellular spheroids. Materials and Methods: Spheroids were incubated with high-specific-activity 125I-mIBG (6 mCi/?g, 1000 times that of the conventional specific activity used for autoradiography). Cytotoxicity was assessed by fluorescence viability markers and confocal microscopy for intact spheroids, fluorescence-activated cell sorting and clonogenic assay, and clonogenic assays for dispersed whole spheroids. Distribution of radioactive mIBG was determined by quantitative light-microscope autoradiography of spheroid cryostat sections. Dose estimation was based on temporal knowledge of the retained radioactivity inside spheroids, and of the radiolabel's emission characteristics. Findings were compared with those of spheroids treated under the same conditions with 131I-mIBG, cold mIBG, and free iodine-125. Results: 125I-mIBG exerted significant cell killing. Complete spheroids were eradicated when they were treated with 500 ?Ci of 125I-mIBG, while those treated with 500 ?Ci or 1000 ?Ci of 131I-mIBG were not. The observed difference in cytotoxicity between treatments with 125I- and treatments with 125I- and 131I-mIBG could not be accounted for by the absorbed dose of spheroid alone. The peripheral, proliferating cell layer of the spheroids remained viable at the moderate radioactivity of 100 ?Ci for both isotopes. Cytotoxicity induced by 125I-mIBG was quantitatively comparable by the peripheral rim thickness to that of 131I-mIBG at the dose of 100 ?Ci. The peripheral rim thickness decreased most significantly in the first 17 hours after initial treatment. There was no statistical decrease in the rim thickness identified afterwards for the second, third, and fourth days of incubation. Conclusion: The cytotoxic effect of high-specific-activity 125I-mIBG appears to be comparable to, if not more efficient than that of conventionally used 131I-mIBG at the same level of total radioactivity. 125I-mIBG may improve the therapeutic index over that of 131I-mIBG in the clinical management of metastatic neuroblastoma due to the short range of Auger electrons

325

The pharmacokinetics and tumor uptake of 125I-recombinant Human plasminogen kringle 5  

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Objective: To establish the method of 125I-labeled recombinant human plasminogen kringle 5 (rhK5), analyze the pharmacokinetics of rhK5 in rats receiving single injection of vein, obtain the biodistribution data from human lung cancer-bearing Bab1/C nude mice. Methods: rhK5 was 125I labeled using the Iodogen method, the radiochemical purity of 125I-K5 was determined by HPLC. Detect the function of 125I-K5 binding to endothelial cells by competition binding study, Assay the bioactivity of 125I-K5 by MTT. 125I-K5 was injected via caudal vein at the dose of 4?g/kg respectively in rats(n=6). Blood samples were collected at different time, then record the radioactivity and analyze the pharmacokinetics parameters according to the 3p87 program. 125I-K5 was also injected via caudal vein at the dose of 4?g/kg in human lung cancer-bearing Bab1/C nude mice(n=12), then collected blood and tissues samples at different time, recoded the radioactivity and analyzed the biodistribution data. Results: The labeling rate of 125I-K5 was above 80%, radiochemical purity was above 95% and which was also above 95% after stored at 40 degree C for 100 hours. Competition binding studies showed a dose-dependent inhibition of 125I-K5 binding to endothelial cells (ECV304) by excess unlabeled K5. MTT showed the proliferation of ECV304 was inhibited by 125I-K5 at ED50 4? g/ml. The pharmaco/sup>I-K5 at ED50 4? g/ml. The pharmacokinetics of 125I-K5 in rats was in correspondence with two-compartment-model, The T1/2(?) was 0.31±0.03 h, T1/2(?) was 14.48±0.73 h and AUC was 436.58±34.6(ng/ml)*h. Biodistribution data showed high uptake in the thyroid gland,kidneys, stomach, liver and lungs. Tumor uptake was respectively 3.84±0.21, 2.39±0.11, 1.94±0.13, 1.48±0.09%ID/g at 2 h, 4 h, 8 h and 12 h after injection. Tumor to muscle count ratio increased from 2.56±0.11 at 2 h to 3.21±0.28 at 8 h, 4.94±0.89 at 12 h. Conclusion: 125I-K5 prepared with Iodogen had high purity and stability, the bioactivity was accordant with unlabeled K5. Half-lives in rats received single injection of vein was about 15 h. The tumor high uptake 125I-K5 by virtue of specially binding to endothelial cells, which was the basis of target therapy for tumor.The accumulation of 125I-K5 in the tumor lay the foundation for the imaging diagnosis. (authors)

326

Clinical and physical determinants for toxicity of 125-I seed prostate brachytherapy  

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Background and purpose: To assess acute as well as long-term toxicity after permanent prostate seed implantation. To find predictive clinical or dosimetric factors for side effects in order to work out strategies for improvement. Patients and methods: A group of 174 patients with localised prostate cancer was treated with permanent seed implantation between 1999 and 2001, either alone (140 patients) or in combination with external radiotherapy (34 patients). For the majority (114/174, i.e. 66%) a CT was performed four weeks after implantation and analysed in the planning system VariSeed. In the postimplant analysis, dosimetric descriptors (doses, volumes) were determined for the prostate and rectum and compared with the intraoperative values. In addition, a questionnaire was sent to all patients to assess and quantify acute and chronic toxicity (urinary, rectal, sexual) and the impact on subjective acceptance and quality of life (return rate of questionnaires 83%). The derived score changes were correlated with clinical and dosimetric factors. Results: In the mono-brachytherapy group 14% (16/140) required a bladder catheter, of them 8% (9/140) with a manifest urinary obstruction. Long-term rectal toxicity (50>240 Gy), which appears to be attributed to unnecessarily high numbers of seeds (for a fixed activity per seed) and needles. The rectal toxicity is correlated with the high dose regions in the rectum (?145 Gy). Urinary toxicity is lower for combined-brachytherapy, while rectal toxicity and impairment of potency are slightly higher. Conclusions: Toxicity spectrum and quality of life after permanent seed implantation for early prostate cancer are acceptable for nearly all patients (98%). To further improve tolerance we should attempt to achieve a better dose homogeneity, i.e. by reducing D50. Therefore, special attention should be given to D50 during the real-time planning process. The necessity of more homogeneous dose distributions might imply a reduction of the activity per seed, e.g. from 0.7 mCi down to 0.6 mCi

327

Selecting Patients for Exclusive Permanent Implant Prostate Brachytherapy: The Experience of the Paris Institut Curie/Cochin Hospital/Necker Hospital Group on 809 Patients  

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Purpose: The aim of this study was to analyze overall and relapse-free survival in a cohort of 809 patients, 34% of whom corresponded to a higher-risk group than American Brachytherapy Society (ABS) criteria. Methods and Materials: Between January 1999 and September 2004, 809 patients were treated with permanent loose 125 iodine seed implantation (IsoSeed Bebig, Eckert and Ziegler) by the Paris Institut Curie, Cochin Hospital, and Necker Hospital group. Of these 809 patients, 533 (65.9%) corresponded exactly to ABS criteria. Two hundred and seventy-six patients (34.1%) had a prostate-specific antigen (PSA) level between 10 and 15, or a Gleason score of 7, or both (non-ABS group). Results: Overall 5-year survival was 98%, with no difference between the ABS group and the non-ABS patient subgroups (p 0.62).Five-year relapse-free survival was 97% in the ABS group; it was significantly lower (p = 0.001) in the non-ABS group but remained satisfactory at 94%. On subgroup analysis, the results appeared to be better for the subgroup of patients with PSA 10-15 than for the subgroup with a Gleason score of 7. Conclusions: Our results suggest that selected patients in the intermediate-risk group of localized prostate cancers can be safely proposed as recipients of permanent implant brachytherapy as monotherapy

328

Preliminary study of correction of original metal artifacts due to I-125 seeds in postimplant dosimetry for prostate permanent implant brachytherapy  

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We investigated a subtraction-based reprojection approach to reduce CT metal artifacts due to I-125 seeds and evaluated the clinical implications in postimplant dosimetry for prostate permanent implant brachytherapy. The raw projection data were used to reduce metal artifacts due to I-125 seeds. CT images of the metal parts only were separated from the original CT images by setting the threshold for pixel value to that of the I-125 seeds. Using these images, sinograms of CT images with and without seeds were obtained by inverse Radon transform (iRT), and the sinogram of the metal image was subtracted from that of the original image. Finally, the image was reconstructed using the sinogram by Radon transform (RT). This technique was applied to a prostate phantom and to a patient undergoing prostate permanent implant brachytherapy. Metal artifacts from I-125 seeds were reduced in both the phantom and patient studies. This technique decreased the density of the inner region of seeds but enhanced the density of the seed edge, thereby facilitating the identification of seed number, orientation, and location. This method reduces metal artifacts from I-125 seeds, and has potential for decreasing the time required for and improving the accuracy of postimplant dosimetry. (author)

329

Study on preparation and brain distribution of 125I-?-CIT  

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Objective: To develop a relatively simpler and faster method for the routine preparation of 125I-?-CIT and animal brain distribution of 125I-?-CIT. Methods: Peracetic acid or Iodogen as an oxidant was used to prepare 125I-?-CIT and comparison was made between them. The HPLC purification technique was used to identify the labeled tracer. Stability and safety of the radioiodinated ?-CIT were also studied. Groups of mice (n=5) were injected i.v. into the tail vein with 125I-?-CIT . Animals were killed at 5, 15, 30 and 45 minutes, and 1, 2, 4, 6, 8 and 24 hours. Autoradiography was performed on brains of mice at 4 hours after injection. Results: Two kinds of labeling methods using Iodogen or peracetic acid produced 125I-?-CIT of radiochemical yields 91.10% ± 8.09%, 54.70 ± 9.81% respectively, with high radiochemical purity (RCP) 99.33% ± 0.15%, 18-25 degree C and pH 1 or 2 is the best for Iodogen preparation. The labeled product was stable for at least 23 days when kept in room temperature, and stable for at least 10 weeks when kept in -4 degree C refrigerator. The peak time of uptake of 125I-?-CIT in striatum was at four hours after injection and the highest value was 22.93% ± 3.11% ID/g. It's highest uptake rate is 20.09 ± 2.11. Conclusions: The Iodogen preparation method is simpler and has a higher labeling yield than peracetic acid labeling method and the labeling yield is higher than which ng yield is higher than which ever reported abroad. The labeled radiopharmaceutical is stable. 125I-?-CIT showed the highest accumulation in striatum with high densities of dopamine transporters in brain

330

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

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

331

[125I]Aminobenzyladenosine, a new radioligand with improved specific binding to adenosine receptors in heart  

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

332

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

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Objective: To discuss the effectiveness and therapeutic mechanism of 125I interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice. Methods: The human pancreatic cell line Sw1990 was subcutaneously injected into the right lower limb partially dorsal area next to the groin of the immunodeficient BABL /c nude mice. The tumor was removed and cut into small pieces after it was formed,then the tumor pieces were inoculated in nude mice. The tumor developed to 8-10 mm in size after six weeks. A total of 16 nude mice with the suitable tumor size were used in this study. The 16 experimental mice were randomly and equally divided into two groups. The mice in study group (n = 8) were implanted with 125I seeds, while the mice in control group (n = 8) were implanted with ghost seeds. After the implantation both the long and short diameter of the tumors as well as the mouse body weight were measured every 4 days. The tumor weight was measured when the mouse was sacrificed. The paraffin-embedded samples were sent for histopathological examination. Apoptotic cells were checked with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Expression of proliferating cell nuclear antigen (PCNA) was detected with immuno-histochemical staining. Results: The tumor grew slowly in the study group, but rapidly in the control group. The tumor weight in the study group and the control group was (2.68 ± 0.70)g and the control group was (2.68 ± 0.70)g and (4.68 ± 1.45)g, respectively, the difference between two groups was statistically significant (P = 0.021). The tumor inhibition rate was about 42.66%. No significant difference in body weight of nude mice existed between two groups both before and after the treatment (P > 0.05). Marked tumor necrosis was seen in study group, but no obvious, or only a little, tumor necrosis could be observed in the control group. The apoptotic index checked with the TUENL method in the study group and control group was (23.2 ± 1.9)% and (8.1 ± 1.5)%, respectively, and the difference between two groups was statistically significant (P 125I interstitial brachytherapy is an effective treatment for transplantation tumor of human pancreatic carcinoma in nude mice. Its mechanisms include directly killing the tumor cells, inducing tumor cell apoptosis and reducing cell proliferation. Additionally, 125I seeds implantation in vivo tumor is safe for the surrounding organs. (authors)

333

Development of miniature 125I sources for the treatment of eye and prostate cancers  

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The aim of the present work was to develop a technology for the fabrication of 125I brachytherapy sources for their potential application in the treatment of eye and prostrate cancers. Several methods of incorporating the 125I activity in solid core were investigated and the best among them, in terms of low leachability, ease of preparation and encapsulation in titanium capsules and reproducibility was chosen. Two kinds of cores, namely rod/cylinder shaped wires and spherical balls, were envisaged for introduction into the titanium capsule. Two procedures for depositing the 125I activity on rod shaped core were explored; namely anodic deposition of 125I on silver wire and physicochemical adsorption of 125I on palladium chloride coated silver wire. Similarly, two methods for depositing 125I on spherical source cores were studied. In the first case, alumina microspheres were used as the core on which 125I was impregnated as iodate (IO-3) using a solid-solution interface technique. In the second, 125I was adsorbed on palladium coated silver beads of 0.5 mm. Various physical and chemical parameters were optimized to obtain quantitative uptake of 125I and firm adsorption that would result in negligible iodine leachability (? 0.01%). The source cores prepared by various methods were encapsulated in indigenously fabricated titanium capsules [4.5mm (l) 0.bricated titanium capsules [4.5mm (l) 0.8mm (OD) and 0.05mm (thickness)]. These capsules were in accordance with the ISO specifications for use as low energy brachytherapy sources. The welding of the capsules was optimized by changing welding parameters such as energy, frequency and pulse duration to obtain neat and leak-proof welded capsules. Integrity of the welding was ascertained by metallographic examination and leak testing. Quality assurance tests such as leak testing and dosimetry that are essential before clinical use were conducted. All the above methods were compared and the one which was easy to prepare in large scale was adopted for preparation of the sources for clinical trials. (author)

334

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

International Nuclear Information System (INIS)

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

335

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

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

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

2013-02-15

336

Preparation of a 125I labelled [1,3H]imidazole: 2-n-butyl-4(5)-125I-iodo-5(4)-hydroxymethylene imidazole  

International Nuclear Information System (INIS)

A method for the introduction of 125I in a substituted imidazole has been devised. 2-n-Butyl-4(5)-hydroxymethylene imidazole undergoes rapid and selective electrophilic substitution on the ring when treated with a halogenating agent such as, i.a., N-chlorosuccinimide. This reaction has been adapted to the preparation of 2-n-butyl-4(5)-125I-iodo-5(4)-hydroxymethylene imidazole by treatment of 2-n-butyl-4(5)-hydroxymethylene imidazole by chloramine-T in the presence of sodium iodide. The radiolabelled product purified and isolated by HPLC is obtained at a high specific activity (2200Ci/mmol) with good chemical and radiochemical yields (?70%). (author)

337

125I-iomazenil-benzodiazepine receptor binding during psychological stress in rats  

International Nuclear Information System (INIS)

We investigated the changes in 125I-iomazenil (125I-IMZ) benzodiazepine receptor (BZR) binding with psychological stress in a rat model. Six male Wistar rats were placed under psychological stress for 1 hour by using a communication box. No physical stress was not received. 1.85 MBq of 125I-IMZ was injected into the lateral tail vein and the rat was killed 3 hours later. Twenty-micormeter-thick sections of the brain were collected and % injected dose per body weight (% ID/BW) of eleven regions (frontal, parietal, temporal, occipital cortices, caudate putamen, accumubens nuclei, globus pallidus, amygdala, thalamus, hippocampus and hypothalamus) were calculated by autoradiography. The %ID/BW of rats which were placed under psychological stress was compared with that of 6 control rats. The %ID/BW of rats which were placed under psychological stress diffusely tended to show a reduction in 125I-IMZ-BZR binding. A significant decrease in BZR binding was observed in the hippocampus of the rats which were placed under psychological stress. 125I-IMZ-BZR binding tended to decrease throughout the brain. (author)

338

{sup 125}I-iomazenil-benzodiazepine receptor binding during psychological stress in rats  

Energy Technology Data Exchange (ETDEWEB)

We investigated the changes in {sup 125}I-iomazenil ({sup 125}I-IMZ) benzodiazepine receptor (BZR) binding with psychological stress in a rat model. Six male Wistar rats were placed under psychological stress for 1 hour by using a communication box. No physical stress was not received. 1.85 MBq of {sup 125}I-IMZ was injected into the lateral tail vein and the rat was killed 3 hours later. Twenty-micormeter-thick sections of the brain were collected and % injected dose per body weight (% ID/BW) of eleven regions (frontal, parietal, temporal, occipital cortices, caudate putamen, accumubens nuclei, globus pallidus, amygdala, thalamus, hippocampus and hypothalamus) were calculated by autoradiography. The %ID/BW of rats which were placed under psychological stress was compared with that of 6 control rats. The %ID/BW of rats which were placed under psychological stress diffusely tended to show a reduction in {sup 125}I-IMZ-BZR binding. A significant decrease in BZR binding was observed in the hippocampus of the rats which were placed under psychological stress. {sup 125}I-IMZ-BZR binding tended to decrease throughout the brain. (author)

Fukumitsu, Nobuyoshi; Tsuchida, Daisuke; Ogi, Shigeyuki; Uchiyama, Mayuki; Mori, Yutaka [Jikei Univ., Tokyo (Japan). School of Medicine

2002-05-01

339

Development of a {sup 125}I source for its application in bone densitometry  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a method for the preparation of {sup 125}I sources for their use in bone densitometer. The process consists of preparation of silver pellets of size {approx}2.5 mm ({phi}) Multiplication-Sign 0.6 mm (l) by 'Cold die compaction technique', palladium coating of the silver pellets, adsorption of {sup 125}I on the palladium coated silver pellets and encapsulation source matrix in a titanium capsule [ 3 mm ({phi}) Multiplication-Sign 10 mm(l)] using Nd:YAG laser. The texture and morphology of the source matrix were examined by SEM and EDS analyses. Encapsulated sources containing {sup 125}I activity up to {approx}1.85 GBq (50 mCi) were prepared. Quality control tests that were necessary before application were performed and gave satisfactory results. - Highlights: Black-Right-Pointing-Pointer Development of technology for the preparation of {sup 125}I sources for bone densitometer. Black-Right-Pointing-Pointer Silver pellets of size {approx}2.5 mm ({phi}) Multiplication-Sign 0.6 mm (l) were prepared by 'cold die compaction technique'. Black-Right-Pointing-Pointer The process consists of palladium coating of silver pellets followed by adsorption of {sup 125}I. Black-Right-Pointing-Pointer The source is encapsulated in a titanium capsule using Nd:YAG laser. Black-Right-Pointing-Pointer The technical feasibility and source quality has been demonstrated.

Saxena, Sanjay Kumar; Kumar, Yogendra [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Pillai, K.T. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Dash, Ashutosh, E-mail: adash@barc.gov.in [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2012-03-15

340

In vivo autoradiographic benzodiazepine receptor imaging with 125I-Iomazenil (Ro 16-0154)  

International Nuclear Information System (INIS)

The biodistribution of 125I-Iomazenil (Ro 16-0154), a benzodiazepine receptor antagonist, was examined using in vivo autoradiography of gerbil brain. 125I-Iomazenil was administrated i.v. into male gerbils, and autoradiography was prepared from coronary sections of the animals decapitated at 5, 60, 120 and 180 min after injection. Initial uptake images (5 min) of 125I-Iomazenil were thought to show blood flow distribution. On the images obtained 120-180 min after administration, high activity of 125I-Iomazenil was observed in the cerebral cortex, amygdala, hippocampus, globus pallidus, thalamus, hypothalamus, superior colliculus, substantia nigra and cerebellar cortex in the areas of which benzodiazepine receptor concentration was reported to be high. However, low activity was observed in the caudate-putamen. Accumulation of 125I-Iomazenil was blocked by pre-administration of flumazenil. 123I-Ro 16-0154 has a high potentiality for benzodiazepine receptor mapping by SPECT. (author)

341

125I-spiperone: a novel ligand for D2 dopamine receptors  

International Nuclear Information System (INIS)

125I-Spiperone binds with high affinity K/sub D/ 0.3 nM) to a single specific site (B/sub max/ 34 pmole/g wet weight) in homogenates of rat corpus striatum. Specific binding is about 40-60 percent of total binding and is displaced stereo-specifically by butaclamol and clopenthixol. Neuroleptic drugs of various classes are potent inhibitors of 125I-spiperone binding (/sub i/'s 1-10 nM). Selective dopamine antagonists such as sulpiride (K/sub i/ 50 nM) and dopamine agonists such as apomorphine (K/sub i/ 200 nM) are also potent inhibitors. The drugs specificity of 125I-spiperone binding correlates well with that of 3H-spiperone binding, providing good evidence that 125I-spiperone labels D2 dopamine receptors in striatal membranes. 125I-Spiperone, with its high specific activity (2200 Ci/mmol) may prove to be a useful ligand in studies examining D2 dopamine receptors in soluble preparations and by autoradiography. Furthermore iodinated spiperone may be useful in radioreceptor assays of neuroleptic drug levels and, in a 123I-labeled form for imaging of dopamine receptors, in vivo, using single photon tomography. 18 references, 4 figures, 1 table

342

Studies of the distribution of intrathecally injected 125I-tetanus antitoxin-F(ab')2  

International Nuclear Information System (INIS)

Overall F(ab')2 and antitetanus-f(ab')2 - fragments were labelled with 125I and injected i.th. into normal juvenile cats and adult rats. One group of rats was normal; in the other, unilateral local tetanus had been induced by injection of tetanus toxin into a M. gastrocnemius. The animals were sacrificed 24 h after the i.th. injection, and tissue samples were taken for histoautoradiography. 125I-antitetanus-F(ab')2 permeated into the extracellular space of the spinal cord, roots, and ganglia but not into the neuronal intracellular space. 125I-overall-F(ab') showed identical permeation behaviour. 125I-antitetanus-F(ab')2 reacted with tetanus toxin issuing from the motoneurons after i.th. injection, forming an immunocomplex around the motorneurons. The immunocomplex was not formed around pseudo-unipolar ganglian cells in the spinal ganglia even though some of the ganglian cells contained tetanus toxin, and 125I-antitetanus-F(ab')2 was present in the extracellular space. As an explanation, it was suggested that tetanus toxin does not permeate into the extracellular space through the membrane of the pseudo-unipolar ganglian cells so that immune reactions will not occur. These findings help to explain the widely divergent results of tetanus therapy by means of i.th. injection of tetanus antitoxin. Recommendations for future therapy measures are derived from the findings. (orig./MG)

343

Critical analysis of [131I]- and [125I]human thyroglobulin labels for radioimmunoassay use  

International Nuclear Information System (INIS)

[125I]- and [131I]thyroglobin (Tg) tracer obtained by two different oxidation methods, chloramine-T (ChlT) and lactoperoxidase (LP-ase), were analyzed to assess their suitability in the development of a RIA. Pairs of tracers which were prepared on a single day using these methods with a single source of 131I and 125I were compared. The following conclusions were reached. (1) Both 131I and 125I isotopes, using Chl-T or LP-ase as oxidants, produce suitable tracers. (2) [131I]Tg can be used repeatedly for 2 weeks without repurification. (3) [125I]Tg, in contrast, has to be rechromatographed weekly on sephadex G-200 to maintain assay sensitivity and adequate maximal binding. (4) Under these conditions, 2- or 9-day tracers with either isotope using Chl-T or LP-ase give similar Tg determinations in the serum. (5) The LP-ase-chromatographed 125I tracer seems to lead to higher maximal binding in the assay than the Chl-T-repurified tracer

344

Synthesis and biologic studies of iodinated (125I/127I) ethidium  

International Nuclear Information System (INIS)

An iodinated (125I/127I) ethidium derivative (3,8-diamino-5-[6'-(p-iodobenzoylamino)-4'-azahexyl]-6 -phenylphenanthridinium chloride hydrochloride) was synthesized and characterized. The labeling yield of the 125I-labeled derivative was 75% for carrier-free 125I, with a radiochemical purity of 95%. The incubation of iodoethidium with calf thymus DNA resulted in a substantial enhancement of fluorescence yield, indicating the intercalation of this compound into DNA. In the presence of iodoethidium, the nuclei of methanol-treated mammalian cells fluoresced, while those of viable cells did not (since the plasma membrane is impermeable to iodoethidium). When viable cells were incubated with the reduced form of the derivative, 125I/127I-dihydroethidium traversed the plasma membrane, was oxidized in the cytoplasm, and intercalated into nuclear DNA. Finally, we tested the hypothesis that larger malignant solid tumors, containing a relatively greater percentage of degenerating permeable cells, can be targeted with 125I-ethidium. In-vivo studies demonstrated a small but positive correlation (R = 0.72) between tumor volume and the uptake of the derivative. Because of the ubiquitous presence of abnormal permeable cells and necrosis in tumors, our results support the belief that radiolabeled DNA-intercalating or DNA-binding molecules may be of diagnostic and therapeutic value for a variety of solid tumorspeutic value for a variety of solid tumors in humans

345

Uptake and binding of 125I-calmodulin by isolated rat renal brush border membrane vesicles  

International Nuclear Information System (INIS)

The authors have investigated the interaction of 125I-calmodulin with isolated rat renal brush border membrane vesicles (BBV) using an experimental protocol which allows us to distinguish between ligand binding to the outside of the vesicles vs. uptake and possible binding to the vesicle interior. By examining the association of 125I-calmodulin with BBV as a function of medium osmolarity (300-1100 mosm) to alter intravesicular space, virtually all ligand interaction with BBV was found to represent uptake of intact 125I-calmodulin into the intravesicular space. Uptake appeared specific by the following criteria: (1) it was largely calcium dependent (2) it was inhibited in a dose dependent fashion by calmodulin and the homologous protein troponin C, but not by unrelated proteins (lysozyme, cytochrome C, insulin) (3) it was inhibited by known calmodulin antagonists (calmidazolium, mellitin, trifluoperazine). Calmodulin uptake may be followed by binding of 125I-calmodulin to intravesicular BBV proteins; calmodulin-binding proteins in BBV with molecular weights of 143K, 118K, 50K, 47.5K, 46.5K and 35K were identified by Western blotting techniques. The specific association of 125I-calmodulin with isolated BBV is of interest in regard to the possible role of this calcium regulatory protein in the protein reabsorptive and ion transport functions of this renal tubular membrane fraction

346

Measurement of cytosol estrogen receptor in human breast cancer using 16?-125I-estradiol  

International Nuclear Information System (INIS)

A radioreceptor assay (RRA) kit using 16?-125I-estradiol-17? (125I-E2) was used to measure cytosol estrogen receptor (ER) in 64 breast cancer patients. The binding of 125I-E2 to breast cancer cytosols yielded a saturation curve and a linear scatchard plot. Satisfactory results for ER number and Kd value were obtained with concentrations of 3.0 - 5.6 mg/ml of cytosol protein. Estrogen receptor activity remained stable during 7 days of tissue storage at -20 deg to -80 deg C. Reproducibility was also satisfactory. There was a significant positive correlation (r = 0.826, p 125I-E2 and conventional assay with 3H-E2. The concordance rate between the two types of assay was 90 %. The results indicate that the RRA kit with 125I-E2 would be of value for routine use in terms of simple procedure and the lack of need for liquid scintillator. (Namekawa, K.)

347

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

International Nuclear Information System (INIS)

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

348

Pathological observations on carcinogenic effects of 125I on rat thyroid  

International Nuclear Information System (INIS)

The results observed on male Wistar rats injected intraperitoneally with 125I of different intensity are described. Animals of six dose groups were subjected to 187, 129, 94, 56, 18.8 and 9.3 Gy respectively. Experimental results showed that 18.8?94 Gy were considered to be the optimal carcinogenic dose range of 125I, and the optimal carcinogenic dose of 125I seemed to be 56 Gy. There was no significant difference between the group with absorbed dose of 9.3 Gy and the control group, suggesting that there might exist a dose limit lower than 18.8 Gy of 125I, below which cancer would not be induced. When the absorbed dose was higher than 129 Gy, the epithelial cells of the thyroid exhiabited degeneration. 125I induced mainly follicular carcinoma and medullary carcinoma. Electron microscopy revealed that all benign and malignant tumors originated from thyroid parenchymal follicular epithelial cells except thyroid medullary carcinoma which derived from parafollicular cells (C cell)

349

Radiation protection of persons living close to patients with radioactive implants  

International Nuclear Information System (INIS)

Background: Permanent interstitial brachytherapy is - in certain cases - a very successful therapeutic option, but application of radioactive implants always results in only gradually diminishing radiation exposure of persons in the patient's immediate surroundings. Material and Methods: Using patients with clinically localized prostate cancer treated with iodine-125 (125I) or palladium-103 (103Pd) as an example, it is shown how a patient, if necessary or wished by him, can, by wearing commercially available X-ray protection shorts, reduce radiation exposure of family members in such a way that at a distance r from the patient a given dose per year is not exceeded. Results: The computational procedures necessary for the determination of the individual periods of wearing X-ray protection clothing are provided in the form of formulae and graphics. All considerations and calculations can also be applied to other radiotherapeutic interventions involving the use of 125I, 103Pd or other ?-sources. Conclusion: If necessary, a patient with permanent radioactive implants can reduce radiation exposure of family members by wearing special X-ray protection clothing for a limited period of time. This kind of radiation protection is very efficient and considerably simpler to accomplish than a reduction of exposure time or an increase of the distance between the patient and family members. (orig.)

350

Affinity of binding of radiolabelled (125I) heparin and low molecular weight heparin fraction CY 222 to endothelium in culture  

International Nuclear Information System (INIS)

Binding of 125I-heparin and its low molecular weight fraction CY 222 to human and porcine cultured endothelium was investigated. The binding was measured over a wide range of heparin or CY 222 concentration in culture medium, from less than 20 times up to more than 30 times of the therapeutic heparin level. A relatively small fraction (less than 1%) of tested products was bound to the endothelium. The process of binding was temperature-independent. A comparable number of endothelial binding sites (approx. 1012/cm2) for both 125I-heparin and 125I-CY 222 was calculated. About 40% totally bound 125I-heparin and 30% of 125I-CY 222 was found in the extracellular matrix of cultured endothelium. The endothelium exhibited a 2.4 times lower affinity for 125I-CY 222 (Kd = 5.59 ± 1.77 ?M) than for 125I-heparin (Kd = 2.35 ± 0.78 ?M). A similar affinity of human and porcine endothelium for 125I-heparin was demonstrated. Cultured endothelium exhibited the same affinity for unlabelled heparin as for 125I-heparin. The endothelium depleted of sialic acid residues bound 1.5 times more of 125I-CY 222 than the control endothelium in culture. (author)

351

Experimental determination of the TG-43 dosimetric characteristics of EchoSeedTM model 6733 125I brachytherapy source  

International Nuclear Information System (INIS)

Recently an improved design of a 125I brachytherapy source has been introduced for interstitial seed implants, particularly for prostate seed implants. This design improves the in situ ultrasound visualization of the source compared to the conventional seed. In this project, the TG-43 recommended dosimetric characteristics of the new brachytherapy source have been experimentally determined in Solid Water trade mark sign phantom material. The measured dosimetric characteristics of the new source have been compared with data reported in the literature for other source designs. The measured dose rate constant, ?, in Solid Water was multiplied by 1.05 to extract the dose rate constant in water. The dose rate constant of the new source in water was found to be 0.99±8% cGy h-1 U-1. The radial dose function was measured at distances between 0.5 and 10 cm using LiF TLDs in Solid Water trade mark sign phantom. The anisotropy function, F(r,?), was measured at distances of 2, 3, 5, and 7 cm

352

Development of a 125I source for its application in bone densitometry.  

Science.gov (United States)

This paper describes a method for the preparation of (125)I sources for their use in bone densitometer. The process consists of preparation of silver pellets of size ?2.5 mm (?) × 0.6 mm (l) by 'Cold die compaction technique', palladium coating of the silver pellets, adsorption of (125)I on the palladium coated silver pellets and encapsulation source matrix in a titanium capsule [ 3 mm (?) × 10 mm(l)] using Nd:YAG laser. The texture and morphology of the source matrix were examined by SEM and EDS analyses. Encapsulated sources containing (125)I activity up to ?1.85 GBq (50 mCi) were prepared. Quality control tests that were necessary before application were performed and gave satisfactory results. PMID:22104498

Saxena, Sanjay Kumar; Kumar, Yogendra; Pillai, K T; Dash, Ashutosh

2012-03-01