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1

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

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

2

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)

3

A Comparison of Acute and Chronic Toxicity for Men With Low-Risk Prostate Cancer Treated With Intensity-Modulated Radiation Therapy or 125I Permanent Implant  

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Purpose: To compare the toxicity and biochemical outcomes of intensity-modulated radiation therapy (IMRT) and 125I transperineal permanent prostate seed implant (125I) for patients with low-risk prostate cancer. Methods and Materials: Between 1998 and 2004, a total of 374 low-risk patients (prostate-specific antigen 125I patients). Median follow-up was 43 months for IMRT and 48 months for 125I. The IMRT prescription dose ranged from 74-78 Gy, and 125I prescription was 145 Gy. Acute and late gastrointestinal (GI) and genitourinary (GU) toxicity was recorded by using a modified Radiation Therapy Oncology Group scale. Freedom from biochemical failure was defined by using the Phoenix definition (prostate-specific antigen nadir + 2.0 ng/ml). Results: Patients treated by using IMRT were more likely to be older and have a higher baseline American Urological Association symptom index score, history of previous transurethral resection of the prostate, and larger prostate volumes. On multivariate analysis, IMRT was an independent predictor of lower acute and late Grade 2 or higher GU toxicity and late Grade 2 or higher GI toxicity. Three-year actuarial estimates of late Grade 2 or higher toxicity were 2.4% for GI and 3.5% for GU by using IMRT compared with 7.7% for GI and 19.2% for GU for 125I, respectively. Four-year actuarial estimates of freedom from biochemical failure were 99.5% for IMRT and 93.5% for 125I (p = 0.09). Conclusions: The IMRT and 125I produce similar outcomes, although IMRT appears to have less acute and late toxicity

4

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

5

A theoretical investigation into the role of tumour radiosensitivity, clonogen repopulation, tumour shrinkage and radionuclide RBE in permanent brachytherapy implants of 125I and 103Pd  

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There is growing clinical interest in the use of 125I (half-life 59.4 days) and 103Pd (half-life 16.97 days) for permanent brachytherapy implants. These radionuclides pose interesting radiobiological challenges because, even with slowly growing tumours, significant tumour cell repopulation may occur during the long period taken to deliver the full radiation dose. This results in a considerable amount of the prescribed dose being wasted. There may also be changes in the tumour volume during treatment (due to oedema and/or shrinkage), thus altering the relative geometry of the implanted seeds and causing additional dose rate variations. This assessment examines the interaction between the above effects and additionally includes allowance for the influence of the relative biological effectiveness (RBE) of the radiations emitted by the two radionuclides. The results are presented in terms of the biologically effective doses (BEDs) and likely tumour control probabilities (TCPs) associated with the various parameter combinations. The overall BED enhancement due to the RBE effect is shown always to be greater than the RBE itself and is greatest in tumours which are radio-resistive and/or fast growing. The biological dose uncertainties are found to be less with 103Pd and the TCPs associated with this radionuclide are expected to be significantly higher in the treatment of some 'difficult' tumours. Using typically prescribed doses 125125I appears to be better for treating radiosensitive tumours with long doubling times and which shrink fairly rapidly. However, unless 125I doses are reduced, this advantage may well be offset by the greatly enhanced biological doses delivered to adjacent normal structures. (author)

6

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

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Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125I and 103Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T) = Vp (1 + M exp(-0.693T/Te)) where Vp is the prostate volume before implantation, M is the edema magnitude and Te is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. ?g(r) ?BED), where ? is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125I and 103Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of 50%, the edema increased tumour cell survival by about 1 and 2 orders of magnitude for 125I and 103Pd seed implants respectively. At the extreme (95% edema magnitude and an edema half-life of 30 days), the increase was more than 3 and 5 orders of magnitude for 125I and 103Pd seed implants respectively. The absolute increases were almost independent of TPDT and the prostate edema did not significantly change the effective treatment time. Tumour cell survival for prostate undergoing CLDRI using 125I or 103Pd seeds may be increased substantially due to the presence of edema caused by surgical trauma. This effect appears to be more pronounced for 103Pd than 125I because of the shorter half-life of 103Pd. If significant edema is observed post implantation, then a boost to the prostate using external beam radiotherapy may be considered as a part of the treatment strategy.

Yue, Ning; Chen, Zhe; Nath, Ravinder

2002-04-01

7

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

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Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both {sup 125}I and {sup 103}Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T)=V{sub p} (1+M exp(-0.693T/T{sub e})) where V{sub p} is the prostate volume before implantation, M is the edema magnitude and T{sub e} is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. D radical S{sub k}{delta}g(r) {phi}-bar{sub an}/r{sup 2}, where r is the distance between a seed and a given point. The distance r is now a function of time because of edema. The g(r) was approximated as 1/r{sup 0.4} and 1/r{sup 0.8} for {sup 125}I and {sup 103}Pd, respectively. By expanding the mathematical expression of the resultant dose rate in a Taylor series of exponential functions of time, the dose rate was made equivalent to that produced from multiple fictitious radionuclides of different decay constants and strengths. The biologically effective dose (BED) for an edematous prostate implant was then calculated using a generalized Dale equation. The cell surviving fraction was computed as exp(-{alpha}BED), where {alpha} is the linear coefficient of the survival curve. The tumour cell survival was calculated for both {sup 125}I and {sup 103}Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of 50%, the edema increased tumour cell survival by about 1 and 2 orders of magnitude for {sup 125}I and {sup 103}Pd seed implants respectively. At the extreme (95% edema magnitude and an edema half-life of 30 days), the increase was more than 3 and 5 orders of magnitude for {sup 125}I and {sup 103}Pd seed implants respectively. The absolute increases were almost independent of TPDT and the prostate edema did not significantly change the effective treatment time. Tumour cell survival for prostate undergoing CLDRI using {sup 125}I or {sup 103}Pd seeds may be increased substantially due to the presence of edema caused by surgical trauma. This effect appears to be more pronounced for {sup 103}Pd than {sup 125}I because of the shorter half-life of {sup 103}Pd. If significant edema is observed post implantation, then a boost to the prostate using external beam radiotherapy may be considered as a part of the treatment strategy. (author)

Yue Ning; Chen Zhe; Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States)

2002-04-01

8

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

International Nuclear Information System (INIS)

Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125I and 103Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T)=Vp (1+M exp(-0.693T/Te)) where Vp is the prostate volume before implantation, M is the edema magnitude and Te is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. D radical Sk?g(r) ?-baran/r2, where r is the distance between a seed and a given point. The distance r is now a function of time because of edema. The g(r) was approximated as 1/r0.4 and 1/r0.8 for 125I and 103Pd, respectively. By expanding the mathematical expression of the resultant dose rate in a Taylor series of exponential functions of time, the dose rate was made equivalent to that produced from multiple fictitious radionuclides of different decay constants and strengths. The biologically effective dose (BED) for an edematous prostate implant was then calculated using a generalized Dale equation. The cell surviving fraction was computed as exp(-?BED), where ? is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125I and 103Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of 50%, the edema increased tumour cell survival by about 1 and 2 orders of magnitude for 125I and 103Pd seed implants respectively. At the extreme (95% edema magnitude and an edema half-life of 30 days), the increase was more than 3 and 5 orders of magnitude for 125I and 103Pd seed implants respectively. The absolute increases were almost independent of TPDT and the prostate edema did not significantly change the effective treatment time. Tumour cell survival for prostate undergoing CLDRI using 125I or 103Pd seeds may be increased substantially due to the presence of edema caused by surgical trauma. This effect appears to be more pronounced for 103Pd than 125I because of the shorter half-life of 103Pd. If significant edema is observed post implantation, then a boost to the prostate using external beam radiotherapy may be considered as a part of the treatment strategy. (author)

9

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 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

10

CT-guided permanent 125I seed brachytherapy for vertebral metastatic cancer  

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dure of CT-guided permanent implanted 125I seeds brachytherapy for vertebral metastatic cancers is a safe effective and minimal invasive method with few complications. It is beneficial not only for pretherapeutic metastasis but also for recurrent tumors after radiotherapy; bearing rather high tolerance and safety. (authors)

11

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

12

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

13

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.

14

Value of CT guided 125I seeds implantation for vertebra metastasis  

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Objective: To evaluate the clinical value of 125I seeds implantation for vertebra metastasis. Methods: By CT guide, 125I seeds were implanted in 22 vertebra metastasis of 15 patients. 3-6 months later, pain and metastasis biggest diameter were observed to judge therapeutic effect. Results: In 22 spinal and paraspinal metastases after implantation of particles, complete remission of pain (O grade)14, partial remission (I grade) 6, a slight relief (II grade) 2, the total effective rate was 90.9% (u=5.41, P125I seed implantation in vertebra metastasis is safe, minimally invasive, and possesses a high efficacy. (authors)

15

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

16

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

17

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)

18

CT guided interstitial 125I seed implantation treatment of refractory lung cancer  

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Objective: To evaluate the clinical value of CT guided interstitial 125I seed implantation treatment of refractory lung cancer. Methods: A total of 35 cases of refractory lung cancer patients underwent 125I seed implantation treatment. Preoperative treatment planning system was used to calculate the distribution of radioactive source, then 2.855-3.087 MBq 125I seeds were implanted into the tumor tissues intraoperatively. Plane implantation of the particles were made every 0.5-1.0 cm. Matched peripheral dose was 150-180 Gy, and 10-130 particles were implanted for each patient, who would be followed up by CT to explore their efficacies two months later. Results: Of the 35 patients, there were complete remission 4 cases,partial remission 27 cases, stable disease 3 cases, and progressive disease 1 cases. The objective response rate was 88.57%. Serious intraoperative and postoperative pneumothorax occurred in 5 patients, among whom transference cure was found 3-10 days later after their closed thoracic drainage, and 7 mild pneumothorax patients healed without more treatment. After follow-up it was found that most toxic reactions were mild and tolerable, and no severe complications were reported like hemoptysis or radiation pneumonia. Conclusion: It is effective, less inasie and of low complication rate in CT guided interstitial 125I seed implantation treatment of advanced refractory lung cancer. (authors)

19

Replacing external beam irradiation with 125I seed implantation as brachytherapy for breast cancer  

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Objective: To investigate the feasibility of replacing post-operative external irradiation with intraoperative interstitial implantation of 125I radioactive seeds in patients with breast cancer. Methods: Twenty-four patients underwent modified radical mastectomy for breast cancer, intraoperative interstitial implantation of 125I seed was carded out evenly over the whole operative field. No post-operative external irradiation was applied. Results: All patients were followed. To date, no locoregional recurrence was observed, nor was any complication related to the treatment. Conclusion: The primary result was satisfactory. More experience is required for definite conclusion. (authors)

20

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

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es 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)

 
 
 
 
21

A dose table describing fractions of peripheral volume for 125I volume implants  

International Nuclear Information System (INIS)

A dose table that provides the dose as a function of fractions of peripheral volume for 125I implants is presented. The table is based on seed distributions from 50 actual patient implants. Computer dosimetry was used to determine peripheral doses and dose ranges within implant volumes. The effects of seed distributation were also examined. The patient data and a study of computer-generated randomized seed coordinates within a given volume suggest that matched doses do not depend strongly on the exact position of each seed. The table provides the means for planning an implant to obtain a desired peripheral dose that can be directly compared with the postimplant computer dose calculation

22

A dose table describing fractions of peripheral volume for 125I volume implants  

International Nuclear Information System (INIS)

A dose table that provides the dose as a function of fractions of peripheral volume for 125I implants is presented. The table is based on seed distributions from 50 actual patient implants. Computer dosimetry was used to determine peripheral doses and dose ranges within implant volumes. The effects of seed distribution were also examined. The patient data and a study of computer-generated randomized seed coordinates within a given volume suggest that matched doses do not depend strongly on the exact position of each seed. The table provides the means for planning an implant to obtain a desired peripheral dose that can be directly compared with the postimplant computer dose calculation

23

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)

24

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

25

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

Science.gov (United States)

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

26

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

International Nuclear Information System (INIS)

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)

27

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

International Nuclear Information System (INIS)

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

28

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)

29

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

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Purpose/Objective: Image-based dose evaluation of permanent brachytherapy implants for prostate cancer is important for optimal patient management after implantation. Because of edema caused by the surgical procedure in the implantation, if the dose evaluation is based on the images obtained too early after implantation, dose coverage will usually be underestimated. Conversely, if the images are obtained too late, the dose coverage will be overestimated. This study uses a biomathematical model to simulate edema and its resolution on 29 patients, so that the optimum time to obtain image scans and perform dose evaluation can be investigated and estimated. Methods and Materials: Edema of a prostate and its resolution has been shown to follow an exponential function V(t) = V(0)(1 + ?V[e-0.693t/Te- 1]) where ?V is the initial relative increase in the prostate volume due to edema (and is related to edema magnitude), and Te (edema half-life) is the time for the edema to decrease by half in volume. In this study, edema was simulated by increasing the volume of preimplant prostate (obtained from ultrasound volume study) to a given magnitude of edema. Similarly, the locations of planned seeds were changed to their corresponding locations in the edematous prostate proportionally. The edema was then allowed to resolve according to the exponential function. The correct dose distribution was calculated by taking into account the dynamic variations of the prostate volume, seed locations, and source strengths with respect to time. Dose volume histograms (DVHs) were then generated from this dose distribution. The conventional postimplant DVHs, which assume the prostate volume and seed locations are as in the image scans and constant in time, were also calculated based on the simulated image scans for various days postimplantation. The conventional DVHs of prostate on various days after implantation were compared to the DVH calculated assuming dynamic conditions. The optimum timing for conventional postimplant dose evaluation was identified as the time at which a minimum difference between the conventional DVH and the dynamic model DVH was achieved. The analysis was done on 29 prostate seed implant patients for both 125I and 103Pd. The edema magnitude was assumed to be 30%, 40%, 50%, 75%, and 100% of original prostate volume, and the half-life of edema was assumed to be 4, 7, 10, 15, 20, and 25 days. In this study, the original volume of prostate varied from 17 cm3 to 91 cm3, and number of seeds in the implants varied from 57 to 119. Results: The optimum timing was mainly dependent on the half-lives of edema and radionuclides, and varied slightly with edema magnitude, prostate volume, and number of seeds. It can be expressed as a function of edema half-life in the form of C0+ C1exp(-C2Te). However, if the dose evaluation was performed based on the image scans taken too early or too late, the error became larger, as the edema magnitude was larger. By averaging all 29 patients and various edemas, it was found that for 125I seed implants, if the postimplant dose evaluation is performed based on image scans taken between 5 and 9 weeks, the average error will be less than 5%, with a maximum possible error less than 10% in 80% coverage dose; for 103Pd seed implants, if the postimplant dose evaluation is performed based on image scans taken between 2 and 4 weeks, the average error will be less than 5%, with a maximum error less than 15% in 80% coverage dose. Because of edema, a conventional preimplant plan also overestimates dose coverage of prostate. On the average, a standard preimplant planning overestimates dose coverage by about 6% for 125I implants and 14% for 103Pd implants in our study. Conclusion: Based on the dynamic model, the optimum timing of image scans for postimplant dose evaluation of prostate seed implantation is 7 weeks postimplantation for 125I implants and about 3 weeks for 103Pd implants. The time-window for reasonable accuracy (± 5%) is ± 2 weeks for 125I a nd ± 1 week for 103Pd around the optimum timing. During preim

30

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

International Nuclear Information System (INIS)

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)

31

Dose verification with Monte Carlo technique for prostate brachytherapy implants with 125I sources  

International Nuclear Information System (INIS)

The Monte Carlo technique has been implemented to generate the dose distributions in a model prostate patient, implanted with iodine-125 (125I) brachytherapy sources. The results of these calculations are also compared with the dose distributions calculated by a commercially available treatment planning system. The comparison shows that with the source strength suggested by the Monte Carlo technique, the current clinical planning system is found to provide 100% coverage of the prostate with the prescription dose for the same implant pattern. However, the dose-volume histogram of this investigation shows that the VariSeedTM treatment planning system has a 29% and 136% larger dose coverage for the 150% and 200% isodose lines, respectively, than the Monte Carlo simulation. These differences are attributed to the oversimplification of the current planning system using the point source approximation, and also to the interseed effects from multisources that are neglected in the conventional planning systems. The results of this study provide evidence that supports the use of the Monte Carlo technique in treatment planning systems to provide accurate dose calculations in brachytherapy implants

32

Relative biologic effectiveness in terms of tumor response of 125I implants compared with 60Co gamma rays  

International Nuclear Information System (INIS)

Purpose: To measure the relative biologic effectiveness (RBE) for 125I seeds compared with external beam radiotherapy using a clinically relevant in vivo system. Methods and Materials: Photon emission from a detailed source model was simulated using the Monte Carlo code MCNP4C, sampling from a 125I spectrum. The mouse RIF-1 tumor was treated with either temporary implant of an 125I seed or with 60Co gamma rays. The tumors were always the same size at the initiation of treatment, and the endpoint was growth inhibition. Results: The dose-response curve for both modalities was close to linear and was independent of the initial 125I activity (dose rate) for the range investigated. Calculation of the RBE for tumor response requires assigning a unique value for the tumor dose that is not homogenous but depends on the distance from the 125I source. Because tumor regrowth will depend on the subpopulation of cells that have the greatest probability of survival (i.e., those at the greatest distance from the 125I source), one approach is to use the dose to this population. On this basis, the RBE for 125I compared with 60Co gamma rays is 1.5. If the 125I dose is computed as the average dose to the tumor, corrected for the dose that is wasted as overkill in the cell population closest to the center of the 125I seed, the RBE is 1.4. Conclusion: The result, an RBERBE is 1.4. Conclusion: The result, an RBE of 1.4-1.5 is similar to findings obtained by other methods, supporting the validity of this approach to derive an RBE with validity in a clinical context

33

Postimplant dosimetry for 125I prostate implants: definitions and factors affecting outcome  

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Objective: An analysis of CT-based dosimetry was performed to assess the efficacy of the real time method of prostate implantation, explore the relationship of various dose descriptions and determine implant factors affecting outcome. Methods and Materials: Between 7/95 and 8/99, 297 patients underwent 125I implants for T1-T2 prostate cancer and had CT-based dosimetry performed (TG43 formalism). Dosimetry was performed 1 month postimplant. Using a dose-volume histogram, doses delivered to 100%, 95%, 90%, and 80% of the prostate (D100, D95, D90, D80, respectively) as well as percentages of the gland receiving 240 Gy, 160 Gy, 140 Gy (V240, V160, V140, respectively) were reported. Correlations between the various dose parameters and D90 were generated. The effect of the number of seeds implanted, seeds/volume, prostate volume, experience as assessed by time (8/01/99--date of implant), ultrasound probe (mechanical sector vs. dual phased electronic), and the ratio of the CT dosimetry prostate volume/ultrasound implant volume (CT/US vol) were analyzed. Results: The median D100, D95, D90, and D80 values were 10,200 cGy, 15,655 cGy, 17,578 cGy, and 19,873 cGy, respectively. The median V240, V160, and V140 were 56%, 94%, and 98%, respectively. Correlations of dose descriptions found a close relationship of D95, D80, V240, V160, and V140 with D90 with r values of 0.928, 0.973, 0.911, 0.816, and 0.733, respectively. D100 correlated poorly with D90 (r = 0.099). Using a stepwise regression analysis, CT/US vol ratio, prostate volume, and seed number were the only significant factors affecting D90 with CT/US vol ratio having the greatest effect. The dual-phased electronic probe was associated with fewer D90 values of less than 140 Gy (2%) compared to the mechanical sector probe (14%) (p = 0.02). Conclusion: CT-based dosimetry results reveal the real-time implant technique to be an effective method of prostate implantation. Factors associated with more precise implantation, such as decreased postimplant edema, new technology, and increased number of seeds will lead to higher D90 values

34

Moessbauer effect studies following ion implantation of 125I and sup(125m)Te radioactivities in crystalline Ge  

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Moessbauer effect spectra of the sup(125m)Te and 125I sources were taken with a thin single line absorber (ZnTe) using a conventional spectrometer in which the source was moved. sup(125m)Te and 125I sources showed similar spectra, which consisted of two partially resolved peaks, and the positive velocity peak exhibited a somewhat larger intensity. The spectra were fitted to superposition of two Lorentzean line shapes. The interpretation of the present data, guided by previous two Te implantation results is the following: the two peaks in these spectra belong to two chemically inequivalent Te sites characterized by different IS's and negligible QI. (Auth.)

35

Results of biopsy after early stage prostatic cancer treatment by implantation of 125I seeds  

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Seventy-seven patients have been treated for clinically early stage carcinoma of the prostate, 9 stage A2, 63 stage B and 5 stage C, with direct implantation of 125I seeds into the prostate and pelvic lymphadenectomy. It is estimated that a minimum dose of 15,000 rad but a maximum dose of 35,000 rad is delivered to the prostate over several months. Of the 77 patients, 14 (18%) had metastatic disease in the pelvic lymph nodes. In 22 cases perineal needle biopsy was done 12 to 18 months after treatment and in 3 cases a second biopsy was performed after 2 to 3 years. Persistent tumor was present in 11 biopsies. Cytological changes were observed in 8 of these, primarily cytoplasmic vacuolation and nuclear pyknosis. There seemed to be no relationship between grade and stage of disease and histological evidence of persistence of tumor after radiation. One patient with persistent tumor in the postoperative biopsy has shown progression of disease after 2 years and another with a negative biopsy has a bony metastasis. The remaining 10 patients with persistent tumor have shown no sign of progression of disease during a 2 to 4-year interval

36

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

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the tumors showed completed relief (CR) in 3 cases, partial relief (PR) in 20 cases, no change (NC) in 14 cases and progression (PD) in 3 cases. The overall effective rate (CR + PR) was 57.5%. The median survival time for all patients was 10.2 months, while it was 14.7 months, 10.9 months and 7.1 months for patients in stage II, stage III and stage IV respectively. For patients in stage II, stage III and stage IV, the 6-month cumulative survival rate was 100%, 88% and 62% respectively, while the 12-month cumulative survival rate was 70% , 41% and 0% respectively. After the therapy, liver metastasis occurred in 5 cases and chemoembolization was employed. In three patients, immigration of four radioactive seeds to the liver was found. No serious complications, such as upper GI bleeding, pancreatitis, pancreatic fistula formation and radiation colitis, occurred during the follow-up period. Conclusion: CT- guided radioactive 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)

37

From manual to 3-D computerized treatment planning for 125I stereotactic brain implants  

International Nuclear Information System (INIS)

Aspects of planning for the treatment of high grade primary or recurrent brain tumors with stereotactically placed catheters afterloaded with high activity 125I seeds are discussed. At our institution, planning has evolved from a simple manual process, which assumed geometric symmetry, through a more advanced manual process, that took advantage of certain mechanical properties of the stereotactic frame used, into a sophisticated, computerized planning approach that includes optimization of the source distribution and 3-D displays. Use of the simple manual method is limited to the rare situations where target volumes are quite regular in shape. The advanced manual method provides some customization for irregularly shaped volumes, but is slow and tedious to implement. The interactive, computerized approach permits identification of target volumes directly on CT slices, reconstructions in arbitrary planes, and optimization of catheter placement, source separation along each catheter, and selection of source strengths from an available inventory. A multi-format display feature which includes a probe's eye view perspective is provided to aid in planning. Integral dose-volume histograms for the target volume point out the advantages in using sophisticated, 3-D, computerized planning systems for these implants

38

Observation on the therapeutic effect of 125I radioactive seeds interstitial implantation for treatment of advanced malignancies  

International Nuclear Information System (INIS)

Objective: To investigate the therapeutic efficacy of 125I radioactive seeds interstitial implantation for late malignancies. Methods: 125I seeds as source of brachytherapy were implanted interstitially into 35 patients with late malignancies not radically resectable (liver, pancreas, prostate cancers etc.) and the patients were closely followed. Results: To date, all patients survive. Three to six months after the procedure, the tumor disappeared totally in six cases (17%+) and diminished in size in 26 cases (74%+). Tumor size did not change in 2 cases, only in one case the tumor expanded further. Basically, pain was satisfactorily alleviated. Conclusion: As a part of adjuvant therapy for late malignancies, this method is safe and applicable with satisfactory therapeutic effect. (authors)

39

Identification of new collagen formation with 125I-labeled antibody in bovine pericardial tissue valves implanted in calves  

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Failure of bovine pericardial tissue valve used in young patients may be due to a slow rejection process. Polyclonal anticollagen (Type I) antibody (IgG) was made in rabbits and purified by protein A affinity column. Two milligrams of IgG was labeled with 2 mCi of 125I by the Iodogen method. Free iodide was separated by G-10 column. Affinity of 125I-IgG was checked by radioimmunoassay. Two hundred and fifty microcuries of 125I-IgG was injected in calves immediately after tissue valve implantation, and the calves were killed 4 h post-injection. After harvesting the valve, each of the three leaflets was separated into four zones, and radioactivity in each section was mapped with a ? counter. The radioactivity in tissue valve section was compared to that of normal aortic valve. The sections of tissue valve retain five to ten times more 125I-IgG than control aortic valve. Iodine-IgG thus provides a sensitive technique for determination of residual antigenicity in tissue valve. (author)

40

Permanent and removable implants for the brachytherapy of brain tumors  

International Nuclear Information System (INIS)

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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Clinical Investigations on the Spinal Osteoblastic Metastasis Treated by Combination of Percutaneous Vertebroplasty and 125I Seeds Implantation Versus Radiotherapy  

Science.gov (United States)

Abstract To investigate the clinical efficacy of combining digital subtraction angiography-guided percutaneous vertebroplasty (PVP) and 125I seeds implantation for the treatment of spinal osteoplastic metastasis. A combination of PVP and 125I implantation was conducted for 50 patients with spinal osteoplastic metastasis, while the other 50 patients who received regular radiation therapy were used as a comparison. Visual analogue pain scale (VAS) and score of life quality (EORTCQLQ-30) were determined for all the patients. Surgery was successful in 89 spinal segments of vertebral body in 50 patients. Each segment of vertebral body was injected with 1–5?mL (2.8?mL for thoracic and 3.1?mL for lumbar vertebral body on average) of bone cement. Postoperative X-ray and CT examination showed that all the patients in the PVP group achieved spinal stability. During the follow-up examination from 6 months to 5 years, 49 patients (98.0%) had significantly relieved back pain, and only 1 case (2.0%) had no obvious improvement. Postoperative VAS score and Karnofsky performance score (KPS) were significantly different from the preoperative scores (p<0.05); and compared to the regular treatment group, PVP combined 125I seeds showed much better clinical efficacy (p<0.05). PVP is a minimally invasive treatment with easy operation and less complications. PVP can effectively relieve the pain, stabilize the spine, improve the life quality, and reduce the occurrence of paraplegia in patients with spinal osteoplastic metastasis. Utilization of 125I seeds with PVP can enhance the clinical efficacy. PMID:23009581

Tan, Jing; Zhao, Ruilian; Wang, Jiaping; Sun, Hongpu; Wang, Xiaoxue; Xu, Lei; Jiang, Hua; Zhang, Jinlei

2013-01-01

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Clinical investigations on the spinal osteoblastic metastasis treated by combination of percutaneous vertebroplasty and (125)I seeds implantation versus radiotherapy.  

Science.gov (United States)

To investigate the clinical efficacy of combining digital subtraction angiography-guided percutaneous vertebroplasty (PVP) and (125)I seeds implantation for the treatment of spinal osteoplastic metastasis. A combination of PVP and (125)I implantation was conducted for 50 patients with spinal osteoplastic metastasis, while the other 50 patients who received regular radiation therapy were used as a comparison. Visual analogue pain scale (VAS) and score of life quality (EORTCQLQ-30) were determined for all the patients. Surgery was successful in 89 spinal segments of vertebral body in 50 patients. Each segment of vertebral body was injected with 1-5 mL (2.8 mL for thoracic and 3.1 mL for lumbar vertebral body on average) of bone cement. Postoperative X-ray and CT examination showed that all the patients in the PVP group achieved spinal stability. During the follow-up examination from 6 months to 5 years, 49 patients (98.0%) had significantly relieved back pain, and only 1 case (2.0%) had no obvious improvement. Postoperative VAS score and Karnofsky performance score (KPS) were significantly different from the preoperative scores (p<0.05); and compared to the regular treatment group, PVP combined (125)I seeds showed much better clinical efficacy (p<0.05). PVP is a minimally invasive treatment with easy operation and less complications. PVP can effectively relieve the pain, stabilize the spine, improve the life quality, and reduce the occurrence of paraplegia in patients with spinal osteoplastic metastasis. Utilization of (125)I seeds with PVP can enhance the clinical efficacy. PMID:23009581

Yang, Zuozhang; Tan, Jing; Zhao, Ruilian; Wang, Jiaping; Sun, Hongpu; Wang, Xiaoxue; Xu, Lei; Jiang, Hua; Zhang, Jinlei

2013-02-01

43

Study on dosimetry of 125I seed in-plane implantation  

International Nuclear Information System (INIS)

Objective: To study the dosimetry of different arrangements of 125I seeds in one plane. Methods: Nine different in-plane arrangements of 9 125I seeds (2.035 x 107 Bq/seed) were simulated according to distance (cm) along x (horizontal)- and y( longitudinal )-axis using the 3-dimensional treatment planning system (TPS) (3D-TPS): x0.5, y0.5; x0.5, y1.0; x0.5, y1.5; x1.0, y1.0; x1.0, y1.5; x1.5, y1.5; x0.5, y0.5 (2)1.0; x0.5, y1.0 (2)0.5; x1.0, y1.0 (2)0.5. The isodose curves of 40,80, 130, 145 and 200 Gy were created and the area, radius and medical cost under the 40, 80, 130, 145 and 200 Gy isodose curves were calculated. Results: The area, radius and medical cost under the same isodose curves were significantly different with each 125I seed arrangement. The arrangements which had the biggest area under curves of 40, 80, 130, 145 and 200 Gy isodose were x1.5, y1.5; x1.0, y1.0; x1.0,y1.0; x0.5, y1.0 and x0.5, y1.0, respectively. Conclusion: The matched peripheral dose and therapeutic effect were affected significantly by the geometric arrangement of 125I seeds. (authors)

44

Anti-tumor effects of 125I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice  

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Objective: To study the anti-tumor effects of 125I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice and clarify their anti-tumor mechanisms. Methods 120 nude mice transplantated with human breast cancer cells MCF-7 were randomly divided into 3 groups (n=40): 125I radioactive particles implanted group, non-radioactive particles implanted group and non-particles implanted group. The articles were implanted into mice according to Pairs system principle. The expressions of Fas mRNA and protein and the activaties of caspase-3 and caspase-8 enzyme were detected by RT-PCR and Western blotting. The changes of cell cycle were detected by flow cytometry. Results: Compared with non-radioactive particles implanted group and non-particles implanted group, the size of cancer tissues in 125I radioactive particles implanted group was reduced significantly (P0/G1 phase was significantly increased (P125I radioactive particles into transplantated tumor model of human breast cancer cells can kill tumor cells, inhibit the growth cycle of tumor cells and induce the apoptosis of tumor cells in nude mice. (authors)

45

The clinical application of 125I seeds implantation together with bronchial arterial infusion chemotherapy for the treatment of advanced lung cancer  

International Nuclear Information System (INIS)

Objective: To assess the clinical value of 125I seeds implantation combined with the bronchial arterial infusion chemotherapy in treating advanced lung cancer. Methods: 125I seeds implantation combined with the bronchial arterial infusion chemotherapy was performed in 30 patients with advanced lung cancer. About 3 -70 seeds of 125I (6711 type, 0.7 mCi / seed) were delivered in each patient. In all patients bronchial arterial infusion chemotherapy was carried out at the time of 7 days before the implantation and 30 and 60 days after the implantation. The results and complications were observed. The clinical data were retrospectively analyzed. The therapeutic efficacy was evaluated according to RECIST standards. Results: A total of 40 lesions were detected in all 30 patients and 125I seeds were successfully embedded in all lesions. No procedure-related complications occurred. All patients were followed up for 2 -24 months. The two-year survival rate was 86.6% (26 / 30). Therapeutic evaluation made at four months after the treatment showed that CR, PR, NC and PD was seen in 26, 10, 2 and 2 lesions respectively,with a total effective rate of 90%. Conclusion: 125I seeds implantation combined with the bronchial arterial infusion chemotherapy is a safe and effective therapy for advanced lung cancer with excellent clinical results. (authors)

46

Clinical efficacy of interstitial implantation of 125I seeds combined with chemotherapy in patients with non-small cell Lung carcinoma  

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To evaluate the clinical efficacy of 125I seed implantation combined with chemotherapy in the treatment of patients with non-small cell lung carcinoma(NSCLC). The patients with NSCLC (n=64) were received interstitially 125I seed implantation by CT-guided, and then were treated with NVB and DDP after three days. In control group (n=70), the patients were only treated with NVB and DDP. The therapeutic efficacy was observed after two,four and six months. The results showed that the effective rates (CR + PR) after two, four and six months of the treatment were 82.8%, 90.6%, 93.7%, respectively. The effective rates in the control group were 4.4%, 48.6%, 52.9%, respectively. The therapeutic effects had significant difference between two groups (P125I seed implantation and chemotherapy in patients with NSCLC to reduce tumor load in a short period and improve the therapeutic efficacy. (authors)

47

Dosimetric characteristics of three new design 125I brachytherapy sources  

International Nuclear Information System (INIS)

For roughly 25 years, 125I sources have been used in the treatment of various malignant diseases such as prostate cancer. Three new brachytherapy sources, IR01-125I, IR02-125I and IR03-125I, have been developed and are designed for permanent implant application. The Monte Carlo radiation transport code version MCNP 5 was used to calculate the dosimetry parameters around the sources in accordance with the updated report of the American Association of Physicists in Medicine (AAPM), Task Group No. 43. For each source, the dose rate constant ?, the radial dose function gL(r), and the anisotropy function F(r, ?), were obtained. The results indicated a dose rate constant of 0.932 ± 0.01, 0.934 ± 0.01 and 0.939 ± 0.01 Gy h-1 U-1 for the IR01-125I, IR02-125I and IR03-125I sources respectively. With the goal of determining an optimal design for a 125I source, each seed's parameters were compared with other seeds. In this study, the optimal source IR03-125I provides the most isotropic dose distribution in water. Finally, the results for optimal source were compared with published results for those of other commercial sources. (orig.)

48

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.

49

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-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

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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

51

Implantation of radioactive 125I seed strand and metallic stent combined with TACE for the treatment of HCC with IVC obstruction: initial results in 8 patients  

International Nuclear Information System (INIS)

Objective: To report the preliminary results of placing metallic stent and 125I seed strand combined with transcatheter arterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma(HCC) with inferior vena cava (IVC) obstruction. Methods: From March 2009 to June 2009, implantation of radioactive 125I seed strand and metallic stent combined with TACE treatment was performed in 8 cases of HCC with malignant IVC obstruction. All patients were males with a mean age of (60.6±9.6) years. 125I seed strand and Z-type self-expandable metallic stent were placed in the obstructive segment of IVC, which was followed by TACE. Before and after the treatment,the diameter of the obstructive segment of IVC, the pressure gradient between right atrium and distal end of obstructive segment of IVC, and the symptoms related to the obstruction were estimated and recorded, the results were compared individually. Clinical follow-up was conducted in all patients. Results: A total of 8 stents and 10 125I seed strands were placed in the obstructive segment of IVC. Altogether 138 125I seeds were implanted in 8 patients. Obvious clinical improvements were obtained after therapy. No complications occurred in all patients except one patient who experienced acute renal dysfunction at the second day after therapy. During a mean of (2.1±0.6) months follow-up, occlusion of IVC stent was detected in 1 patient. The remaining stents remained patent. Conclusion: Our initial results indicate that placement of 125I seed strand and metallic stent combined with TACE is a safe and feasible therapeutic option for advanced HCC with malignant IVC obstruction. (authors)

52

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

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

53

Sequential Changes of Serum Tumor Markers Before and After the Radioactive 125I-seed Implantation in the Treatment of Lung Cancer  

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Full Text Available Background and objective The brachytherapy with iodine seeds is characterized by radioactive 125I very close to or in contact with the target organ. This study is to evaluate the clinical value of implanted radioactive 125I-seed in the treatment of lung cancer patients. Methods Sixty-three cases of lung cancer were enrolled in this study, and in every case, 125I-seeds were planted into tumor mass guided by CT. Serum CEA, CA125, NSE and CYFRA21-1 weredetected by radioimmunoassay in lung cancer patients before and after planting. The therapeutic effect was evaluated by WHO standards. The relation between the therapeutic effect and the tumor markers levels was observed. Results Just one month after planting, the levels of serum CEA, CA125, NSE and CYFRA21-1 were induced significantly in all cases. There was no significant difference among 1 month, 3 month and 6 month in the levels of tumor markers after therapy. Conclusion 125I-seed could effectively decrease the level of tumor markers in the treatment of lung cancer patients.

Gang DAN

2009-02-01

54

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

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Purpose: To determine whether dose distribution achieved with treatment plans using high- and low-activity {sup 125}I 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) {sup 125}I 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-activity seeds for experienced teams. (orig.)

Pinkawa, M.; Maurer, U.; Mulhern, A.; Gagel, B.; Eble, M. [Dept. of Radiotherapy, Univ. Hospital, RWTH Aachen (Germany); Block, T. [Urologic Practice, Vaterstetten (Germany); Borchers, H. [Dept. of Urology, Univ. Hospital, RWTH Aachen (Germany); Grieger, J. [Inst. for Clinical Radiology, Radiation Clinic, Univ. Hospital, Mannheim (Germany); Henkel, T. [Outpatient Surgical Center (Ambulantes Operationszentrum im Ullsteinhaus GmbH), Berlin-Tempelhof (Germany)

2003-06-01

55

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

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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 ...

Saika, Takeshi; Takemoto, Mitsuhiro; Kobuke, Makoto; Kobayashi, Yasuyuki; Kobayashi, Tomoko; Manabe, Daisuke; Nose, Hiroyuki; Edamura, Kohei; Tanimoto, Ryuta; Katayama, Yoshihisa; Ebara, Shin; Nasu, Yasutomo; Kanazawa, Susumu; Kumon, Hiromi

2008-01-01

56

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

International Nuclear Information System (INIS)

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

57

Dosimetric characteristics of three new design {sup 125}I brachytherapy sources  

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For roughly 25 years, {sup 125}I sources have been used in the treatment of various malignant diseases such as prostate cancer. Three new brachytherapy sources, IR01-{sup 125}I, IR02-{sup 125}I and IR03-{sup 125}I, have been developed and are designed for permanent implant application. The Monte Carlo radiation transport code version MCNP 5 was used to calculate the dosimetry parameters around the sources in accordance with the updated report of the American Association of Physicists in Medicine (AAPM), Task Group No. 43. For each source, the dose rate constant {lambda}, the radial dose function g{sub L}(r), and the anisotropy function F(r, {theta}), were obtained. The results indicated a dose rate constant of 0.932 {+-} 0.01, 0.934 {+-} 0.01 and 0.939 {+-} 0.01 Gy h{sup -1} U{sup -1} for the IR01-{sup 125}I, IR02-{sup 125}I and IR03-{sup 125}I sources respectively. With the goal of determining an optimal design for a {sup 125}I source, each seed's parameters were compared with other seeds. In this study, the optimal source IR03-{sup 125}I provides the most isotropic dose distribution in water. Finally, the results for optimal source were compared with published results for those of other commercial sources. (orig.)

Khanmohammadi, Zahra [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Science and Research Branch; Sadeghi, Mahdi [Agricultural, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of). Nuclear Science and Technology Research Institute

2011-11-15

58

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

International Nuclear Information System (INIS)

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)

59

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

Rivard, M.J. [Tufts-New England Medical Center, Dept. of Radiation Oncology and Medical Physics, Boston, MA (United States); Butler, W.M.; Merrick, G.S. [Wheeling Jesuit Univ., Schiffler Cancer Center, WV (United States); Devlin, P.M. [Brigham and Women' s Hospital, Dept. of Radiation Oncology, Boston, MA (United States); Hayes, J.K. [Brigham and Women' s Hospital, Dept. of Radiation Oncology, Boston, MA (United States); Hearn, R.A. [Gamma West Brachytherapy, Salt Lake City, UT (United States); Lief, E.P. [Mount Sinai Medical Center, Dept. of Radiation Oncology, New York, NY (United States); Meigooni, A.S. [Kentucky Univ., Dept. of Radiation Medicine, Lexington, KY (United States); Williamson, J.F. [Medical College of Virginia, Dept. of Radiation Oncology, Richmond, VA (United States)

2008-01-15

60

A clinical method for real-time dosimetric guidance of transperineal 125i prostate implants using interventional magnetic resonance imaging  

International Nuclear Information System (INIS)

Purpose: The clinical utility of an interventional magnetic resonance (IMR)-guided implant technique with real-time dosimetric feedback is presented. Methods and Materials: The work was carried out at a IMR unit at Brigham and Women's Hospital. Planning and dosimetric feedback were provided by a software system that provides an interface to the IMR images, anatomy demarcation, template registration, dose calculation engine for planning, and evaluating the implant. Planning during the procedure permits the incorporation of actual needle trajectories in the dose calculations. Results: Fifteen patients were planned in the treatment position. During source placement, actual needle locations were incorporated into the dose calculations. After accounting for the observed needle trajectories of the planned needles, 14 of 15 patients (93%) required additional sources to achieve the desired coverage of the target volume. Conclusion: A brachytherapy implant procedure which provides clinically significant advances has been implemented. Specifically, the planning system allows dosimetric validation of the needle placement. This procedure is effective in delivering brachytherapy to the target volume and assuring that the implant is delivered in accordance with the preplan. The dosimetric feedback could be incorporated in ultrasound-guided implants

 
 
 
 
61

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

62

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

International Nuclear Information System (INIS)

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)

63

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.

Sutherland, J. G. H.; Furutani, K. M.; Thomson, R. M.

2013-10-01

64

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

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

65

Relationship of pretreatment transurethral resection of the prostate to survival without distant metastases in patients treated with /sup 125/I-implantation for localized prostatic cancer  

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The authors assessed the relationship between transurethral resection of the prostate (TURP) and the probability of survival without distant metastases (survival) in patients with clinically localized prostatic cancer. Fifty-eight patients with obstructive voiding symptoms who underwent TURP within 12 months before pelvic lymphadenectomy and /sup 125/I-implantation were compared with 131 patients who did not require TURP before implantation. None received other treatment for the tumor. The overall survivals for the two groups were not significantly different, P greater than 0.1. When stratified by tumor grade or the presence or absence of pelvic lymph node metastases, the survivals for the two groups were also similar, P . greater than 0.1. However, survival associated with Stage C tumors was greater in the No TURP than in the TURP group (P . 0.003), and survival associated with Stage C tumors was greater in the TURP than in the No TURP group (P . 0.005). These data fail to provide convincing evidence that transurethral resection of prostatic cancers has an unfavorable impact on disease progression.

Fowler, J.E. Jr.; Fisher, H.A.; Kaiser, D.L.; Whitmore, W.F. Jr.

1984-05-01

66

Relationship of pretreatment transurethral resection of the prostate to survival without distant metastases in patients treated with 125I-implantation for localized prostatic cancer  

International Nuclear Information System (INIS)

The authors assessed the relationship between transurethral resection of the prostate (TURP) and the probability of survival without distant metastases (survival) in patients with clinically localized prostatic cancer. Fifty-eight patients with obstructive voiding symptoms who underwent TURP within 12 months before pelvic lymphadenectomy and 125I-implantation were compared with 131 patients who did not require TURP before implantation. None received other treatment for the tumor. The overall survivals for the two groups were not significantly different, P greater than 0.1. When stratified by tumor grade or the presence or absence of pelvic lymph node metastases, the survivals for the two groups were also similar, P . greater than 0.1. However, survival associated with Stage C tumors was greater in the No TURP than in the TURP group (P . 0.003), and survival associated with Stage C tumors was greater in the TURP than in the No TURP group (P . 0.005). These data fail to provide convincing evidence that transurethral resection of prostatic cancers has an unfavorable impact on disease progression

67

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

68

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

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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

69

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

70

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

International Nuclear Information System (INIS)

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 (125I) 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 (Dp90, Vp100, and Vp400) were on average lower than the values of the CT postplan. Normalized to the CT postplan the following mean values were found: Dp90: 90.6% (standard deviation [SD]: 9.0%), Vp100: 86.1% (SD: 14.7%), and Vp400: 79.4% (SD: 14.4%). For three out of the eight patients the Dp90 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.)

71

Optimal drug release schedule for in-situ radiosensitization of image guided permanent prostate implants  

Science.gov (United States)

Planned in-situ radiosensitization may improve the therapeutic ratio of image guided 125I prostate brachytherapy. Spacers used in permanent implants may be manufactured from a radiosensitizer-releasing polymer to deliver protracted localized sensitization of the prostate. Such devices will have a limited drug-loading capacity, and the drug release schedule that optimizes outcome, under such a constraint, is not known. This work determines the optimal elution schedules for 125I prostate brachytherapy. The interaction between brachytherapy dose distributions and drug distribution around drug eluting spacers is modeled using a linear-quadratic (LQ) model of cell kill. Clinical brachytherapy plans were used to calculate the biologic effective dose (BED) for planned radiation dose distributions while adding the spatial distributions of radiosensitizer while varying the temporal release schedule subject to a constraint on the drug capacity of the eluting spacers. Results: The greatest increase in BED is achieved by schedules with the greatest sensitization early in the implant. Making brachytherapy spacers from radiosensitizer eluting polymer transforms inert parts of the implant process into a means of enhancing the effect of the brachytherapy radiation. Such an approach may increase the therapeutic ratio of prostate brachytherapy or offer a means of locally boosting the radiation effect without increasing the radiation dose to surrounding tissues.

Cormack, Robert A.; Nguyen, Paul L.; D'Amico, Anthony V.; Sridhar, Sri; Makrigiorgos, Mike

2011-03-01

72

Temporary inhibition of permanently implanted demand pacemakers.  

Science.gov (United States)

Temporary inhibition of permanently implanted demand pacemakers has been previously described. Demand pacemakers may be inhibited by waving a magnet over the region of the pacemaker generator or by chest wall stimulation. The former may not inhibit most of the bipolar pacemakers, whereas the latter may be time consuming and may casue patient discomfort. Another method is described which utilized a commercially available Cordis Omnicor Programmer, Model 166-B, to temporarily inhibit bipolar and unipolar pacemakers. By placing the programmer over the skin where the pacemaker generator is implanted and/or over the area of the subcutaneous pervenous lead and activating the programmer multiple times at a rate faster then the pacing rate, the demand pacemakers are inhibited. After testing the efficacy in vitro, the method was successfully tried on 45 patients. Fifteen of these patients had unipolar pacemakers. Pacemakers marketed by Medtronic, Cordis, Starr-Edwards, C.P.I., and Arco were tested. Temporary inhibition of permanent demand pacemakers is desirable under various clinical situations. The method herein described has the advantages of being simple, quick, painless, and is effective for both unipolar and bipolar pacemakers. PMID:830215

Latif, P; Ewy, G A

1977-01-01

73

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)

74

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.

75

Salvage low-dose-rate 125I partial prostate brachytherapy after dose-escalated external beam radiotherapy  

Science.gov (United States)

Purpose To report outcomes on 5 patients treated with salvage partial low-dose-rate (LDR) 125-iodine (125I) permanent prostate seed brachytherapy (BT) for biopsy-proven locally persistent prostate cancer, following failure of dose-escalated external beam radiotherapy (EBRT). Material and methods A retrospective review of the Fox Chase Cancer Center prostate cancer database identified five patients treated with salvage partial LDR 125I seed implant for locally persistent disease following dose-escalated EBRT to 76-84 Gy in 2 Gy per fraction equivalent. All patients had post-EBRT biopsies confirming unilateral locally persistent prostate cancer. Pre-treatment, EBRT and BT details, as well as post-treatment characteristics were documented and assessed. Results The median follow-up post-implant was 41 months. All five patients exhibited low acute genitourinary and gastrointestinal toxicities. Increased erectile dysfunction was noted in three patients. There were no biochemical failures following salvage LDR 125I seed BT to date, with a median post-salvage PSA of 0.4 ng/mL. Conclusions In carefully selected patients with local persistence of disease, partial LDR 125I permanent prostate seed implant appears to be a feasible option for salvage local therapy with an acceptable toxicity profile. Further study is needed to determine long-term results of this approach.

Chang, Lynn

2014-01-01

76

Image fusion techniques in permanent seed implantation  

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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

77

Femoral approach: an exceptional alternative for permanent pacemaker implantation.  

Science.gov (United States)

The classic transvenous implantation of a permanent pacemaker in a pectoral location may be precluded by obstruction of venous access through the superior vena cava or recent infection at the implant site. When these barriers to the procedure are bilateral and there are also contraindications or technical difficulties to performing a thoracotomy for an epicardial approach, the femoral vein, although rarely used, can be a viable alternative. We describe the case of a patient with occlusion of both subclavian veins and a high risk for mini-thoracotomy or videothoracoscopy, who underwent implantation of a permanent single-chamber pacemaker via the right femoral vein. PMID:24931177

Tereno Valente, Bruno; Conceição, José M; Nogueira da Silva, Manuel; M Oliveira, Mário; S Cunha, Pedro; Lousinha, Ana; Galrinho, Ana; C Ferreira, Rui

2014-05-01

78

Computer tomographic-guided stereotactic interstitial therapy of cerebral tumours by means of temporary or permanent implantation of 125iodine seeds  

International Nuclear Information System (INIS)

Therapy resistance of inoperable malignant gliomas is an unsolved problem for radiotherapy. A combination of interstitial therapy and percutaneous high voltage therapy is described which should improve the prognosis of brain tumours when it has been perfected. For all tumours of low malignancy we recommend the permanent implantation of 125iodine seeds of low activiy (10-60 mCi 125I, D sub(o)=6-10 rad/h.) as the primary form of treatment, possibly supplemented by high voltage therapy. For tumours of higher malignancy, temporary implantation of high activity 125I is indicated (more than 200 mCi, D sub(o) = 25-100 rad/h.) as local boost before or after total volume irradiation of brain. Our experience of 30 patients up to date is encouraging. (orig.)

79

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)

80

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 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

 
 
 
 
81

Permanent LDR implants in treatment of prostate cancer  

International Nuclear Information System (INIS)

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

82

Urethral dose and increment of international prostate symptom score (IPSS) in transperineal permanent interstitial implant (TPI) of prostate cancer  

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Purpose: to find the factors which influence the acute increment of international prostate symptom score (IPSS) after transperineal permanent interstitial implant (TPI) using {sup 125}I seeds. Patients and methods: from April 2004 through September 2006, 104 patients with nonmetastatic prostate cancer underwent TPI without external-beam irradiation. Median patient age was 70 years with a median follow-up of 13.0 months. 73 patients (70%) received neoadjuvant hormone therapy. The increment of IPSS was defined as the difference between pre- and postimplant maximal IPSS. Clinical, treatment, and dosimetric parameters evaluated included age, initial prostate-specific antigen, Gleason Score, neoadjuvant hormone therapy, initial IPSS, post-TPI prostatic volume, number of implanted seeds, prostate V{sub 100}, V{sub 150}, D{sub 90}, urethral D{sub max}, and urethral D{sub 90}. In order to further evaluate detailed urethral doses, the base and apical urethra were defined and the dosimetric parameters were calculated. Results: the IPSS peaked 3 months after TPI and returned to baseline at 12-15 months. Multivariate analysis demonstrated a statistically significant correlation of post-TPI prostatic volume, number of implanted seeds, and the dosimetric parameters of the base urethra with IPSS increment. Conclusion: the base urethra appears to be susceptible to radiation and the increased dose to this region deteriorates IPSS. It remains unclear whether the base urethral dose relates to the incidence of late urinary morbidities. (orig.)

Murakami, N.; Itami, J. [Dept. of Radiation Therapy and Oncology, International Medical Center of Japan, Tokyo (Japan); Div. of Radiation Therapy, National Cancer Center Hospital, Tokyo (Japan); Okuma, K.; Marino, H.; Ban, T.; Nakazato, M.; Kanai, K.; Naoi, K.; Fuse, M. [Dept. of Radiation Therapy and Oncology, International Medical Center of Japan, Tokyo (Japan); Nakagawa, K. [Dept. of Radiology, School of Medicine, Tokyo Univ. (Japan)

2008-10-15

83

Preparation of 125I-lipiodol  

International Nuclear Information System (INIS)

An isotopic exchange method has been used to label lipiodol with 125I. The labelling efficiency is more than 92% in the optimum condition (using ethanol as reaction medium, 100 degree C, 20 min) and the radiochemical purity of 125I-lipiodol is above 98% as determined by TLC and HPLC. The labelling process does not change the chemical structure of lipiodol. The 125I-lipiodol is stable at least in one month at room temperature

84

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

85

Temporary and permanent inferior vena cava filter combination in a young patient: to implant or not to implant?  

Science.gov (United States)

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. PMID:14753313

Kutlu, Ramazan; Alkan, Alpay; Sigirci, Ahmet; Altinok, Tayfun; Yildirim, Zeki

2003-01-01

86

Rectal injury during permanent seed implantation for prostate brachytherapy  

International Nuclear Information System (INIS)

Serious complications have not been previously reported during seed implantation for prostate brachytherapy. We present an unreported case of rectal injury caused by an ultrasound probe. A 67-year-old male presented with a serum prostate-specific antigen level of 5.50 ng/ml, a Gleason score of 7 (3+4) and clinical T2a adenocarcinoma of the prostate. A transperineal permanent prostate brachytherapy implantation was performed. The patient subsequently complained of abdominal pain postoperatively. A gastrointestinal perforation was suspected based on an abdominal X-ray obtained on the day after the brachytherapy. Rectal injury was recognized during an exploratory laparotomy, and a primary closure and temporary diversion ileostomy were performed. The healing of the injury was confirmed by colonoscopy and an ileostomy closure was performed 2 months after the temporary diversion. The investigating committee for this accident concluded that the ultrasound probe had perforated the rectum. This is the first case of a rectal injury during seed implantation for prostate brachytherapy. (author)

87

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

International Nuclear Information System (INIS)

Purpose: To determine the tumor cell damage effect with Auger-electron emitter 125I in different chemical states. Methods: (1) [Tyr3] octreotide (TOC) and UdR are labeled with 125I,respectively. (2) Receptor analysis of 125I-TOC on small cell lung cancer (SCLC) NCI-H446 cell lines is performed comparing with normal lymph cells. NCI-H446 cells added various dose of 125I-TOC are incubated for different time with 125I-Nal and non-labeled TOC as control. The capacity of NCI-H446 cell lines bound and internalization of 125I TOC are determined. The radiation damage of tumor cells is measured by MTF methods. (3) The killing effects of 125I-UdR in human pancreatic cancer cell line Bax-Pc and Sca-BER bladder carcinoma cells are evaluated with the similar methods. I-UdR penetrating into the Sca-BER cell nucleus is observed with confocal microscope. The grow suppression and clonogenic formation of Sca-BER cells after incubation with 125I-UdR are analyzed. Proliferation fraction and S phase cell fraction of Sca-BER cell added 125I-UdR is measured with flow cytometric analysis. Results: (1) Kd=(0.56?2.0) x 10-11 mol/L and Bmax=(1.17?2.0) x 105 cell site are obtained by receptor analysis of 125I-TOC on NCI-H446 cells. Comparatively, the difference between total binding and non-specific binding is low and there is no saturationding is low and there is no saturation of specific binding for normal lymphocyte. About 50% of 125I-TOC is internalized into the NCI-H446 cell nucleus at 24h after incubation. The damige of NCI-H446 cells by 125I-TOC is clearly observed. (2) The penetration amount of 125I-UdR into cell nucleus increases with the incubate time when the concentration of 125I-UdR is in the range of 10?500 kBq/mL and reaches the peak fraction of 94% at 36 h after incubation. The radioactivity of 125I-UdR is then achieved equelibration and no more increased with time. The linear correlation with ?=0.867?0.978 between the concentration of 125I-UdR in cell nucleus and the incubation time is observed before reaching peak value. As a control, very low radioactivities in cells and in neucleus are measured in Na 125I case. Incubating for 36 h, the amount of 125I-UdR entering into the cells and nucleus are 1000 times more than that with Na 125I. The 125I-UdR killing effect of 100 kBq to Bax-Pc cells is 60 times more than Na 125I after 36 h incubation. The Sca-BER bladder carcinoma cells growth cycle in the treatment group with 125I-UdR is suppressed and clonogenic formation is lower in experimental group than in control group. Proliferation fraction and S phase cell fraction decrease and apoptosis fraction increase with 125I-UdR treatment time. The results of confocal microscope shows the Sca-BER cells of treatment group at 48h after administration are entirely broken. Conclusion: 125I-TOC has a better specificity to the somatostatin positive tumors. 125I-UdR is a cell cycle dependent agent. It can be incorporated into DNA of Bax-Pc cells and can selectively kill tumor cells in S phase. Both 125I-TOC and 125I-UdR are more effective for killing tumor cells than Na 125I.

88

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)

89

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

90

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.

91

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)

92

Production and storage of (125-I) thyroxine and (125-I) triiodothyronine of high specific activity.  

Science.gov (United States)

High specific activity [125-I] triiodothyronine and [125-I] thyroxine have been produced regularly by the chloramine T radioiodination method. Simultaneous production of [125-I] triiodothyronine and [125-I] thyroxine is usual when diiodothyronine or triiodothyronine are employed as the starting materials. Specific activities reached vary with the starting compound (diiodothyronine, triiodothyronine, thyroxine) used, as both substitution and, less readily, exchange of iodine atoms take place. Starting with diiodothyronine specific activities of approximately 2400 and 5200 Ci/g were achieved for [125-I]triidothyronine and [125I] thyroxine, respectively, and, similarly, specific activities of approximately 1200 and 4000 Ci/g for [125I] triiodothyronine and [125I]-thyroxine, respectively, were reached when triiodothyronine was the starting material. [125-I] Triiodoacetic acid and [125I] tetraiodoacetic acid have been produced in the same way from triiodoacetic acid. By column chromatography on Sephadex G-25 (fine), eluting with alkaline phosphate buffer, good separation of the radioiodinated products has been readily achieved. Studies on the stability of the radioiodinated hormones showed that 50% methanol, ethanol, propanol and propylene glycol were all equivalent as preserving agents and, further, that the stability of the radioiodinated hormones was linearly related to the concentration of these preserving agents. PMID:238770

Kjeld, J M; Kuku, S F; Diamant, L; Fraser, T R; Joplin, G F; Mashiter, K

1975-06-20

93

False positive 125I fibrinogen test  

International Nuclear Information System (INIS)

125I fibrinogen test was performed in 20 selected patients who presented with symptoms suggestive of deep venous thrombosis. The incidence of a false positive study was found to be very high: 90%. An increased accumulation of fibrinogen was noted over recent, well-healed surgical incisions, diffuse or focal inflammatory sites, hematoma and also, following a venogram or arthrogram test. The large number of coincidental circumstances that result in an abnormal accumulation of 125I fibrinogen lead us to believe that venogram is the procedure of choice in patients with symptoms simulating thrombophlebitis

94

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)

95

A novel circular free-air-chamber for the realization of the french national dosimetric standard for prostate permanent implants  

International Nuclear Information System (INIS)

Full text of publication follows: Prostate permanent implants of 125-I and 103-Pd are an interesting alternative to surgery or conventional radiotherapy for the treatment of initial stages of prostate cancers. Its development has increased dramatically in North America during these last years and it is expected that a similar situation might occur in Europe and especially in France in the coming years. The Laboratoire National Henri Becquerel has started the development of the French national dosimetric standard for these sources. This will give a way to medical physicists to calibrate the sources before implantation and to guarantee therefore, as for conventional radiotherapy treatments, the precise knowledge of the delivered dose to patient. The sources are characterized by: their small size (cylinder: L = 5 mm, diam. 0.8 mm), a low energy and fast decaying isotope (21 to 28 keV, half-life = 59 to 17 d), a low individual activity of the seeds (<100 MBq), and a strong source anisotropy. Therefore only to large volume free air ionization chambers are able to measure, at the required precision level, the air -kerma delivered by a single source. A large volume circular (torus-shaped) free-air-chamber has been designed; the outer diameter of the chamber will be 1 m and the source will be located at the centre of the detector. This configuration will allow a large collecting volume combined with a large detected solid angle, a high sign al-to-noise ratio, and a self-compeh sign al-to-noise ratio, and a self-compensation of source anisotropy. Great care has been taken for the optimization of electric fields in order to ensure a good knowledge of the collected volume and to limit the magnitude of H.V. polarity effects. The detector will be described exhaustively together with the results of preliminary tests. (author)

96

Preparation of 125I-creatine phosphokinase-MM  

International Nuclear Information System (INIS)

125I-creatine phosphokinase-MM (125I-CPK-MM) was prepared by 125I-labelled Bolton-Hunter reagent (HPNS). Iodinating conditions of HPNS and its conjugation to protein were studied. 125I-CPK-MM with immune activity was obtained and used to establish the 125I-CPK-MM radioimmunoassay method by the General Hospital of PLA. 125I-CPK-MM in PBS-G solution containing 0.015 mol/l ethyl mercaptan at 4-10 deg C can be used for one month

97

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

98

Dosimetric and functional analysis of 227 patients treated by permanents prostate implants; Analyse dosimetrique et fonctionnelle de 227 patients traites par implants prostatiques permanents  

Energy Technology Data Exchange (ETDEWEB)

The brachytherapy of prostate by permanent implants is included in the armamentarium of localized prostate cancers with external radiotherapy and radical prostatectomy. The quality evaluation of implantation is essential for the patient and the team managing him. Our retrospective work consisted in analysing the whole of dosimetry data and urinary, digestive and sexual functional results of patients treated in our centers. conclusion: the post-implantation dosimetry analysis is essential to improve the technique and to understand the evolutions. The method of scanning evaluation is difficult but is currently the most used by its accessibility. The low urinary, rectal and sexual morbidity of the brachytherapy makes of this treatment an attractive technique for the patients should be well selected. (N.C.)

Champeaux-Orange, E.; Wachter, T. [CHR, 45 - Orleans (France); Le Floch, O.; Haillot, O.; Peneau, M.; Raynaud-Bougnoux, A. [CHU, 37 - Tours (France)

2009-10-15

99

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

100

Probability of late rectal morbidity in 125I prostate brachytherapy  

International Nuclear Information System (INIS)

Purpose: Rectal toxicity is a concern in prostate brachytherapy because it is difficult to avoid delivering a dose equal to, or greater than, the prescription dose to the anterior surface of the rectum. The purpose of this study was to define the probability that a patient will experience Grade 2 (bleeding/ulceration) late rectal morbidity after 125I prostate brachytherapy according to the rectal dosimetry. Methods and Materials: Ninety-eight consecutive patients who received monotherapy 125I prostate implants for treatment of Stage T1-T2, favorable-risk adenocarcinoma of the prostate were evaluated for Radiation Therapy Oncology Group Grade 2 late rectal morbidity. All reported incidences of late morbidity were retrospectively confirmed by colonoscopy. All patients had at least 15 months follow-up after implantation. The median follow-up was 32 months (range 15-54). The rectal dosimetry was based on a CT scan obtained at 3-9 weeks after implantation. The rectum was contoured on each CT image between the base and apex of the prostate. A dose-surface histogram was compiled for each implant, and the relative surface area that received a dose ?100, ?150, ?200, ?300, ?400, and ?500 Gy was recorded. The probability of developing late rectal toxicity was calculated by logistic regression analysis as a function of dose and the percentage of the rectal surface that received that dose. Results: Of the 98 patients, 10 developed Grade 2 late rec 10 developed Grade 2 late rectal morbidity. The percentage of the rectal surface that received 100, 150, 200, and 300 Gy was significantly greater (p ?0.02) for patients who experienced late rectal morbidity. The probability of late rectal morbidity increased with both the dose and the percentage of the rectal surface that received that dose. The probability was ?1% when 20%, 7%, and 0% of the rectal surface received 100, 150, and 200 Gy, respectively. The probability increased to ?5% when 31%, 19%, and 9% of the rectal surface received these doses. The probability of late rectal morbidity can also be expressed in terms of the maximal rectal dose. The probability of late morbidity was 0.4%, 1.2%, and 4.7% when the maximal rectal dose was 150, 200, and 300 Gy, respectively. Conclusion: The percentage of the rectal surface that receives a dose ?100 Gy is predictive of Grade 2 (bleeding/ulceration) late rectal morbidity after 125I prostate brachytherapy. The probability of late morbidity depends on both the dose and the percentage of the rectal surface that received that dose. Our results indicate that the rectum can tolerate doses of 100, 150, and 200 Gy to approximately 30%, 20%, and 10% of the rectal surface with a ?5% risk of late morbidity. Our results also indicate that the practical guideline for limiting the incidence of late morbidity to 1%, 3%, or 5% is to keep the maximal rectal dose to <200, 250, and 300 Gy, respectively

 
 
 
 
101

Determination of radiochemical purity of 125I-TOC and 125I-F-PGA  

International Nuclear Information System (INIS)

To explore whether there is accordance among three determination methods of the radiochemical purity of [Tyr3] octreotide (TOC) and folate-penicillin G amidase conjugate (F-PGA), which are both labeled with 125I by Iodogen method, the RCP of the labelings are determined by high performance liquid chromatography (HPLC), paper chromatography and trichloroacetic acid (TCA) precipitation, in which four different concentrations of proteins are used to investigate the effect of them on the determination of RCP. It is shown that both HPLC and paper chromatography can separate the labelings from free iodine efficiently, though HPLC is the most precise and reliable method to determinate RCP of such labelings. In TCA precipitation, the RCP measured with 0.2%BSA is the lowest, but those with three other concentrations of the BSA are similar (P>0.05). When RCP0.05), whereas higher than that with HPLC (P10%, the RCP of 125I-TOC obtained by TCA precipitation is a bit lower than those by two other methods (P0.05), and there are no significant differences to determinate the RCP of 125I-F-PGA (P>0.05). The three methods are correlated each other (r=0.0996-0.999, P<0.001). (authors)

102

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

103

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 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. 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).

104

Absorption of 125I and 3H in aquatic plants  

International Nuclear Information System (INIS)

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

105

Assessment of wrought ASTM F1058 cobalt alloy properties for permanent surgical implants.  

Science.gov (United States)

The behavior of the ASTM F1058 wrought cobalt-chromium-nickel-molybdenum-iron alloy (commonly referred to as Elgiloy or Phynox) is evaluated in terms of mechanical properties, magnetic resonance imaging, corrosion resistance, and biocompatibility. The data found in the literature, the experimental corrosion and biocompatibility results presented in this article, and its long track record as an implant material demonstrate that the cobalt superalloy is an appropriate material for permanent surgical implants that require high yield strength and fatigue resistance combined with high elastic modulus, and that it can be safely imaged with magnetic resonance. PMID:9283968

Clerc, C O; Jedwab, M R; Mayer, D W; Thompson, P J; Stinson, J S

1997-01-01

106

Labelling of ochratoxins with 3H or 125I  

International Nuclear Information System (INIS)

Catalytic hydrogenation of ochratoxin A by carrier-free tritium was used to prepare 3H-ochratoxin B with a high specific activity. Iodination of ochratoxin B by carrier-free Na 125I using the chloramine method yielded 125I-ochratoxin with a high specific activity. Another 125I-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)

107

The contamination on farm products from 125I  

International Nuclear Information System (INIS)

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

108

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

109

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

International Nuclear Information System (INIS)

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

110

Scattering of gaseous 125I from a bottle containing Na125I solution for iodination in a calm condition  

International Nuclear Information System (INIS)

Scattering of gaseous 125I from a bottle containing Na125I solution for iodination has been measured by distributing active charcoal granule at various heights on the inner surface of a plastic cylinder surrounding the bottle and counting the activities of granule samples. The result shows that about 70% of total scattered 125I exist below the level of mouth of the bottle. By drawing the air from the bottle of the cylinder through a tube filled with active charcoal, about 90% of scattered 125I collected. (author)

111

Synthesis and binding of [125I2]philanthotoxin-343, [125I2]philanthotoxin-343-lysine, and [125I2]philanthotoxin-343-arginine to rat brain membranes  

International Nuclear Information System (INIS)

125I2-iodinated philanthotoxin-343 (PhTX-343), [125I2]PhTX-343-arginine, and [125I2]PhTX-343-lysine were synthesized and evaluated as probes for glutamate receptors in rat brain synaptic membranes. It was found that these probes were not specific for the glutamate receptors but may be useful for investigating the polyamine binding site. Filtration assays with Whatman GF/B fiber glass filters were unsuitable because the iodinated PhTX-343 analogues exhibited high nonspecific binding to the filters, thus hindering detection of specific binding to membranes. When binding was measured by a centrifugal assay, [125I2]PhTX-343-lysine bound with low affinity (KD = 11.4 ± 2 microM) to a large number of sites (37.2 ± 9.1 nmol/mg of protein). The binding of [125I2]PhTX-343-lysine was sensitive only to the polyamines spermine and spermidine, which displaced [125I2]PhTX-343-lysine with Ki values of (3.77 ± 1.4) x 10(-5) M and (7.51 ± 0.77) x 10(-5) M, respectively. The binding was insensitive to glutamate receptor agonists and antagonists. Binding results with [125I2]PhTX-343-arginine were similar to those of [125I2]-PhTX-343-lysine. Considering the high number of toxin binding sites (10000-fold more than glutamate) in these membranes and the insensitivity of the binding to almost all drugs that bind to glutamate receptors, it is evident that most of the binding observed is not to glutamate receptors. On the other hand, PhTX analogues with photoaffinity labels may be useful in photoaffinity labels may be useful in the isolation/purification of various glutamate and nicotinic acetylcholine receptors; they could also be useful in structural studies of receptors and their binding sites

112

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

113

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

114

Synthesis and biodistribution of 125I labeled bivalent analogs of practolol as potential myocardial imaging agents  

International Nuclear Information System (INIS)

Iodinated bivalent ligands 3 and 4 and a monovalent ligand 5 were prepared from the cardioselective ?-antagonist, practolol. 125I-labeled 3, 4 and 5 were prepared by solid phase isotopic exchange reaction with carrier-free Na125I and examined in rats as potential receptor-site-directed myocardial imaging agents. Biodistribution of these agents in rats indicated that 125I-3 and 125I-4 were localized in the heart similarly to 125I-5 and the [125I]iodobenzoyl practolol (6) that was previously reported. Localization of 125I-3 and 125I-4 was more persistent in the heart than that of 125I-monovalent ligands 5 and 6. Heart-to-blood ratios of 125I-3 and 125I-4 were significantly lower than those of 125I-5 and 125I-6, due mainly to slow blood clearance rates of 125I-3 and 125I-4. (author)

115

Error tolerance of Pd-103 Vs I-125 in permanent implants for prostate carcinoma  

International Nuclear Information System (INIS)

Purpose: Permanent prostate implants use either Pd-103 and I-125 radioactive isotopes. Identical loading techniques are used to implant the prostate despite the difference in energy and half-life between the isotopes. While the differences in the initial dose rate of the isotopes are accounted for in the ideal pre-plans, their effect on placement errors and prostate swelling are not addressed. We have investigated four loading techniques and studied the impact of placement error and organ swelling on prostate volume coverage. Material and Methods: Four loading techniques were studied. a) Uniform loading on a 1 cm grid with 1 cm spacing between seeds in a needle. b) Differential loading on a 0.5 cm grid with variable spacing between seeds in a needle c) Peripheral loading and d) Spiked loading with greater activity in the lobes. Ideal plans were first developed to ensure that at least 99% of the prostate volume received a prescribed dose of 160 Gy and 120 Gy for I-125 and Pd-103 implants, respectively. Placement errors were introduced (1) into the ideal plan and the DVH for the prostate was calculated after enhancing the source activity by 15%. Finally, the ideal plan source strengths were enhanced by 30% to account for both placement error and prostate volume expansion that is associated with the implant procedure, and the plans evaluated for target (prostate volume + 0.5 cm margin) coverage and urethra dose. Results: Percentage of the prostate and target receiving thge of the prostate and target receiving the prescribed dose from various loading techniques. Conclusion: Peripheral loading best covers the target for both I-125 and Pd-103. Pd-103 implants are more sensitive to placement error due to sharp dose fall off. Arbitrarily enhancing the activity per source does not quite eliminate the effects of error and swelling for Pd-103 implants. Increasing the number of sources can reduce this effect, but raises the cost of the implant

116

Permanent biventricular ICD-implantation in a heart failure second re-do-CABG patient : a case report  

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Biventricular pacing has been suggested in end-stage heart failure. We present a 59-year-old patient undergoing second re-do CABG (coronary artery bypass graft) and carotid artery endarterectomy. Ejection fraction was 15%, QRS-width 175 ms. Following the carotid and CABG procedure, an implanted single-chamber ICD (implantable cardioverter defibrillator) was upgraded to permanent biventricular DDD pacing by implantation of one epicardial left ventricular and one epicardial atrial electrode. At...

Dzemali, Omer; Monsefi, Nadejda; Moritz, Anton; Kleine, Peter

2009-01-01

117

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)

118

Self-shielding effect of 125I brachytherapy seeds  

International Nuclear Information System (INIS)

In this work,the self-shielding effect of 125I seed source was investigated. Adopting the direct and indirect methods,the self-shielding coefficients of 125I seed source core, which were prepared under technical conditions of self-established palladium method, were measured. The results show that with certain surface areas of the adsorbing basal materials, the initial activities of adsorbing solution do not affect adsorbing rates of the basal materials, and the self-shielding coefficients of 125I seed source core are about 64%, and the addition of NaS2O3 makes the self-shielding effect coefficients decline greatly. (authors)

119

Stereotactic iodine-125 brachytherapy for brain tumors: temporary versus permanent implantation  

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Full Text Available Abstract Stereotactic brachytherapy (SBT has been described in several publications as an effective, minimal invasive and safe highly focal treatment option in selected patients with well circumscribed brain tumors 40?cGy/h in combination with adjuvant external beam radiation and/or chemotherapy for the treatment of malignant gliomas and metastases resulted in increased rates of radiation induced adverse tissue changes requiring surgical intervention. Vice versa, such effects have been only minimally observed in numerous studies applying low dose rate (LDR regiments (3–8?cGy/h for low grade gliomas, metastases and other rare indications. Besides these observations, there are, however, no data available directly comparing the long term incidences of tissue changes after HDR and LDR and there is, furthermore, no evidence regarding a difference between temporary or permanent LDR implantation schemes. Thus, recommendations for effective and safe implantation schemes have to be investigated and compared in future studies.

Ruge Maximilian I

2012-06-01

120

Permanent interstitial implantation of 125iodine in case of carcinomas of the oral and the oropharynx  

International Nuclear Information System (INIS)

The authors present their first experiences gained during the last year with the permanent implantation of 125iodine seeds in thirty patients suffering from carcinomas of the oral cavity and the oropharynx. The properties and advantages of 125iodine, the method of implantation, the dosimetry and the problems of radioprotection are particularly underlined. In every case, we apply pre- or postoperative external radiotherapy, i. e. we expose the primary tumor to a dose of 50 Gy fractionated in the usual manner over four or five weeks. This combined treatment is intended to overcome the resistance to therapy of ORL malignomas and to obtain a high local rate of tumor control and a low rate of functional and cosmetic troubles. (orig.)

 
 
 
 
121

Permanent-magnet type electron cyclotron resonance (ECR) ion source for heavy ion implanter  

International Nuclear Information System (INIS)

A new ECR ion-source has been designed to have a mirror field produced by permanent magnet for heavy ion implanter. A similar plasma-chamber size as normal-conducting ECR ion source was designed. Design aim of magnetic field is to in start a plasma chamber of 50 mm inner diameter and a hexapole magnet of 150 mm length with 12-14 GHz operation. We could to design near magnetic field of design aim for ECR ion source with 12-14 GHz operation. The new ECR ion source was first operated by 12-14 GHz. (author)

122

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

International Nuclear Information System (INIS)

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

123

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)

124

Response of LiF powder to 125I photons.  

Science.gov (United States)

125I seeds are being used to treat a variety of diseases, including brain tumors. However, the uncertainty in the energy response of LiF for 125I photons relative to megavoltage radiation limits the accuracy of dosimetry with this material. An array of 12 40-mCi 125I seeds was used to irradiate LiF powder in throwaway capsules, and an ion chamber was used to measure the absorbed dose. A comparison of the response of these LiF dosimeters with the response of capsules given a similar dose of 60Co radiation has yielded values of 1.39 +/- 0.03 (dose to water) and 1.32 +/- 0.03 (dose to muscle) for the LiF response for 125I relative to that for 60Co. Details of the procedure and sources of uncertainty are discussed. PMID:6513891

Weaver, K A

1984-01-01

125

Synthetic heparinoids labelled with 125I and 35S  

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The labelling of a water-soluble synthetic polyelectrolyte, having anticoagulant activity, has been studied. The polyelectrolyte is derived from cis-1,4-polyisoprene and contains N-sulfate and carboxylate groups. [125I]-Iodination of the polyelectrolyte, using the Chloramine-T method and an electrolytic method, resulted in a [125I]-labelled polyelectrolyte from which release of the label occurred. Resulfation of a partially desulfated polyelectrolyte with a [35S]-sulfur trioxide trimethylamin...

Sederel, L. C.; Kolar, Z.; Does, L.; Bantjes, A.

1982-01-01

126

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

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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; Agoston, Péter; Major, Tibor; Gõdény, Mária; Andi, Judit; Lengyel, Zsolt; Polgár, Csaba

2014-09-26

127

Study on preparation of 125I iodination labelling of leptin  

International Nuclear Information System (INIS)

125I-LEP was prepareded by 125I with indirect iodination and direct iodination respectively, to develop RIA for method comparison. For indirect iodination, BH agent was iodinated by ch-T , then conjugated with leptin. Specific radioactivity of 125I-LEP was 1.43 MBq/?g, to- tal labelling rate of 125I -37.8%. The Bmax of 125I-LEP-97.5%, NSB-6.7% and B0-43.7%. The sensitivity was 0.25 ?g/L , CV of within and between assay-7.8% and 12.90%, respectively. The recovery rate was 96.4%-103.2%, there was no cross-reaction with TSH, LH,FSH, PRL,GH and Ins, the correlation coefficient between results of indirect iodination method and that of Linco Kit was 0.951. Standard curve stability of 125I-LEP prepared by indirect iodination was much better than that by the direct iodination in 45 days, which can satisfy the needs in clinic use. (authors)

128

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

129

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

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The dose rate effect of radiation by 125I 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-1 while that in ten eyes with low activity plaques was 239.9 cGy hr-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, 125I 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)

130

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

131

Stereotactic iodine-125 brachytherapy for brain tumors: temporary versus permanent implantation.  

Science.gov (United States)

Stereotactic brachytherapy (SBT) has been described in several publications as an effective, minimal invasive and safe highly focal treatment option in selected patients with well circumscribed brain tumors technique is hindering the definition of a clear legitimation of SBT in modern brain tumor treatment. These controversies encompass the question of how intense the irradiation should be delivered into the target volume (dose rate). For instance, reports about the use of high does rate (HDR) implantation schemes (>40 cGy/h) in combination with adjuvant external beam radiation and/or chemotherapy for the treatment of malignant gliomas and metastases resulted in increased rates of radiation induced adverse tissue changes requiring surgical intervention. Vice versa, such effects have been only minimally observed in numerous studies applying low dose rate (LDR) regiments (3-8 cGy/h) for low grade gliomas, metastases and other rare indications. Besides these observations, there are, however, no data available directly comparing the long term incidences of tissue changes after HDR and LDR and there is, furthermore, no evidence regarding a difference between temporary or permanent LDR implantation schemes. Thus, recommendations for effective and safe implantation schemes have to be investigated and compared in future studies. PMID:22713629

Ruge, Maximilian I; Kickingereder, Philipp; Grau, Stefan; Treuer, Harald; Sturm, Volker; Voges, Juergen

2012-01-01

132

NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants  

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One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.

Thompson, S. A.; Fung, A. Y. C.; Zaider, M.

2002-08-01

133

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. 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

134

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

135

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)

136

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

International Nuclear Information System (INIS)

A comparative study of performance of 19-iodo cholesterol 125I 3-acetate and sodium iodide samples labeled with 125I 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 ?g 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 1 I 3-acetate samples in Tolue ne-alcohol and 0 .04% for Na 125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs

137

125I-ochratoxin and method of its preparation  

International Nuclear Information System (INIS)

The preparation is patented of a new compound whereby chlorine in position 5 in an ochratoxin molecule is replaced by the 125I radionuclide. Aradioligand is thus obtained of a high molar activity. The compound can be used as a radioligand in ochratoxin RIA in biological materials. (E.J.)

138

Preparation and purification of 125I-labeled iodospiroperidol  

International Nuclear Information System (INIS)

Iodine-125 labeled spiroperidol, a dopamine antagonist, has been synthesized by a simple, one-step procedure starting from spiroperidol. This synthesis employs 125I- and H2O2 in buffered acetic acid. This pH dependent reaction affords iodospiroperidol in 40% radiochemical yield and a specific activity, after HPLC purification, of ca. 1900 Ci/mmol. (author)

139

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

140

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

Science.gov (United States)

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 extracellular-signal-regulated kinase (ERK) pathway. Here we show that radioactive 125I seeds more effectively inhibit NPC cell growth through DNA damage and subsequent induction of apoptosis, compared with X-ray irradiation. Moreover, cell migration was effectively inhibited by 125I seed irradiation through VEGF-A/ERK inactivation. VEGF-A pretreatment significantly blocked 125I seed irradiation-induced inhibition of cell migration by recovering the levels of phosphorylated ERK (p-ERK) protein. Interestingly, in vivo study results confirmed that 125I seed irradiation was more effective in inhibiting tumor growth than X-ray irradiation. Taken together, these results suggest that radioactive 125I seeds exert novel anticancer activity by triggering DNA damage and inactivating VEGF-A/ERK signaling. Our finding provides evidence for the efficacy of 125I seeds for treating NPC patients, especially those with local recurrence. PMID:24040157

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

2013-01-01

 
 
 
 
141

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

Energy Technology Data Exchange (ETDEWEB)

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

142

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%

143

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

International Nuclear Information System (INIS)

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

144

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)

145

Preparation and evaluation of 125I-aflatoxin B1  

International Nuclear Information System (INIS)

Aflatoxin B1 (AfB1), present in fungus infested crops is highly carcinogenic and is measured by immunoassays. 125I labeled aflatoxin B1 is a key reagent for development of radioimmunoassay (RIA) which exhibits less interference and better sensitivity than other immunoassays. Since AfB1 lacks suitable functional groups for radiolabeling, an oxime derivative of AfB1 was synthesised and evaluated by UV-spectrophotometry and 1H NMR spectroscopy. 125I-histamine was conjugated to AfB1 oxime by mixed anhydride method and purified by solvent extraction followed by TLC. The tracer obtained was immunoreactive, stable as ethanolic solution and could be used in RIA. (author)

146

Preparation of [125I]thyroxine by isotopic exchange  

International Nuclear Information System (INIS)

The method is described of [125I]thyroxine preparation by isotopic exchange. Using the method, preparations were obtained of a specific activity of around 4,000 MBq/mg. The preparations are more pure and stable than those prepared by other methods using iodination agents which can cause product degradation. In actual conditions, the reaction yield ranged around 85%; discussed are the effects of the individual reaction conditions. Data on the preparation stability are shown. (author)

147

Comparative biological efficacy of 125I and 131I  

International Nuclear Information System (INIS)

An experimental study of comparative biological efficacy of 125I and 131I at equal absorbed doses (2.3 and 13 Gy) in the thyroid of rats showed that the blastomogenic effect of both radionuclides was almost the same. Sex differences were found in the development of delayed conseguences (20 mos. after drug administration): breast tumors developed in female rats and thyroid tumors in male rats

148

Detection of thrombocyte antibodies by 125I labeled protein A  

International Nuclear Information System (INIS)

Protein A from Staphylococcus aureus interacts in a specific manner with most subclasses of human IgG. In the present study a method is described which utilizes Protein A labeled with 125I for the detection of antibody sensitization of platelets. The clinical applicability of the test for detection of in vivo or in vitro sensitization is demonstrated in three patients with platelet antibodies. (author)

149

Production of 125I seed sources for brachytherapy uses  

International Nuclear Information System (INIS)

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)

150

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

151

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

Science.gov (United States)

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 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. PMID:18777938

Chiu-Tsao, Sou-Tung; Medich, David; Munro, John

2008-08-01

152

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%

153

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

154

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

International Nuclear Information System (INIS)

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)

155

Labeling Lanreotide with 125I and 188Re. China  

International Nuclear Information System (INIS)

Lanreotide (D-?-Nal-Cys-Try-D-Trp-Lys-Val-Cys-Thr-NH2) is a new somatostatin analogue. It can bind to human somatostatin receptor (hSSTR) subtype 2 through 5 with high affinity and to hSSTR subtype 1 with low affinity. We investigate labeling condition, quality control and stability in vitro of 125I-Lanreotide and 188Re-lanreotide respectively. (A) Lanreotide is labeled with 125I using Chloramine T. The effect of reaction condition (such as reaction time, pH value, Lanreotide amount, quantity of Chloramine T and reaction volume) on labeling yield is investigated in detail. (B) The labeling yield and radiochemical purity (RP) is measured with paper chromatography (PC) and Sep-Pak C18 Cartridge. For PC method, 125I-Lanreotide is spotted on the Whatman No.1 paper and developed in the mixture of CH3CH2CH2CH2OH and CH3CH2OH and NH4OH (v/v/v=5:2:1), the Rf value of every component in the mobile phase is given in table 1. For Sep-Pak C18 Cartridge methods each cartridge is washed with 10 ml of ethanol followed by 10 ml of iso-CH3CH2CH2OH solution. Aliquots of 0.1 mI sample is loaded onto the cartridge, unbound peptide (sodium iodine-125) is eluted with 5 ml of 0.5mol/L sodium acetate solution, 125I-Lanreotide is eluted with 5 mI of 95% aqueous ethanol solution. (C) The stability of 125I-Lanreotide in vitro is investigated by labeling compound incubating for 48 hours at 37 deg. C in the 0.9% sodium chloride solution and RP is tested by PC at specific time intervals. (D) Lanreotide is labeled directly with 188Re via the mixture of citrate and tartate using stannous chloride as reduced agent. The influence of reaction conditions such as pH, temperature, amount of stannous chloride, amount of Lanreotide and reaction time on labeling yield is investigated in detail. At the time, the stability in vitro quality control and animal test are evaluated

156

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

International Nuclear Information System (INIS)

The prostate cancer, which is the second cause of death by cancer in men, overcome only by lung cancer, is a problem of public health in Brazil. Brachytherapy is among the possible available treatments for prostate cancer, in which small seeds containing 125I 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 125I. 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 125I 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)

157

Experimental and theoretical determination of dosimetric characteristics of IsoAid ADVANTAGETM 125I brachytherapy source  

International Nuclear Information System (INIS)

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

158

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

159

Radiation effect of 125I UdR on growth of Sca-BER cells  

International Nuclear Information System (INIS)

Objective: To determine the inhibition effects of 125I UdR in human bladder cancer cell line Sca-BER. Methods: 125I UdR were added to the RPMI1640 culturing medium. The amount of 125I UdR uptaken by Sca-BER cells was evaluated through measuring the radioactivity per cell; the killing effects of 125I UdR on Sca-BER cells were estimated by colony forming method. To determine the co-inhibition effects of MTX, 125I UdR and MTX were added to medium, measuring the radioactivity per cell. Results: The amounts of 125I UdR uptaken by Sca-BER was growing up as function of 125I UdR dose in the medium (r=0.99). The surviving fraction was correlated with the concentration of 125I UdR (r=-0.9). The LD50 of 125I UdR group was (1.17 ± 0.27) kBq/ml and the surviving fraction of 125I UdR group was significantly lower than that of Na125I group (P125I UdR of the same concentration was added to the medium. With time elapsing, the amount of 125I UdR and MTX were added to medium, the amount of 125I UdR uptaken was increased for 10 times. Conclusions: 125I UdR can be incorporated into Sca-BER cells, and the concentration of 125I UdR in Sca-BER cells was influenced by 125I UdR dose in the medium. The inhibitory radiation effects of 125I UdR on Sca-BER cells are obvious. (aup>I UdR on Sca-BER cells are obvious. (authors)

160

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 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)

 
 
 
 
161

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)

162

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

International Nuclear Information System (INIS)

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)

163

Estimation and measurement of exposure doses to the circumstance and patients after Iodine-125 seeds permanent interstitial implanting  

International Nuclear Information System (INIS)

Objective: To measure the exposure doses to the personal after implanting Iodine-125 seeds into the simulated human-body, phantom. Methods: The exposure dose rates were detected by FD3101 gamma-dosimeter at the phantom surface and the locations at 30 cm and 100 cm from the phantom, respectively. Extensive dose equivalent measurements were performed at various organ locations in the phantom, using TLD dosimeters. Results: All results were listed in table 1 and table 2. Conclusion: Exposure doses have been measured and calculated after Iodine-125 seeds implant. They are much lower than those presented in national standards, it is believed that Iodine-125 seeds permanent interstitial implant is promising radiotherapeutic application

164

[Morbimortality of infective endocarditis associated with permanent cardiovascular implantable electronic devices].  

Science.gov (United States)

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 diagnosis, 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. PMID:24502180

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

2013-12-01

165

An algorithm for efficient metal artifact reductions in permanent seed implants  

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-01-15

166

An algorithm for efficient metal artifact reductions in permanent seed implants  

International Nuclear Information System (INIS)

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

167

Labelling and validation of progesterone-11-?-hydroxy hemisuccinate (125I)  

International Nuclear Information System (INIS)

Progesteron is a steroid hormone secreted by the corpus luteum and the adrenal cortex in the hypophise gland. The hormone can be used for monitoring pregnancy and even more for the assessment of the corpus luteum in fertile woman (4). The labelling of progesterone with 125I was carried out for tracer production in the preparation of Progesterone Kit used in the determination of the progesterone derivate has been done. The labelling was carried out in two steps reaction. First the progesterone derivate was activated using N-methyl morpholine and isobutylchloroformate. The second step was performed by conjugating the labelled 125I Histamin to the activated progesterone derivate. The labelled compound was purified with HPLC followed with the determination of the chemical purity using electrophorosis, the immunoreactivity controlled with the maximum binding of the zerro standard and the non specific binding using the Progesterone Kit. Experimental results showed that the iodination of Progesterone -11-?-hidroxy hemisuccinate (125I) yield 22.15%, chemical purity 92.30%, the radioimmunoreactivity 51% as maximum binding (for zero standard), with NSB 0.67%, and the spesific activity obtained 7.72 Ci/ g. Validation of the tracer using control (low, medium and high) shows the results as follows : (2.72 ± 0.49)nmol/L for low standard and control (1.2 - 2.5 nmol/L), (11.3 ± 1.15) nmol/L for medium standard and control (6-15 n/mol) and (15.95 ± 5.32 ) nmol/L for high standard and control (10-23 nmol/L). The sensitivity of the assay was (0.70 ± 0.024 nmol/L) for zero standard

168

Preparation and biological studies of 125I-DOTA-TATE  

International Nuclear Information System (INIS)

DOTA-TATE, a somatostatin analog was radiolabeled with 125I in good yields and high radiochemical purity. The product exhibited good stability in vitro. Pharmacokinetic studies in normal Swiss mice showed rapid blood clearance with low thyroid uptake. Biodistribution studies in murine melanoma showed 3.0±1.3% ID/g uptake in tumor at 3 h post injection (p.i.), with negligible reduction at 24 h p.i. Inhibition studies carried out in vivo using cold DOTA-TATE confirmed the tumor specificity of the product

169

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

170

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

Energy Technology Data Exchange (ETDEWEB)

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 {sup 125}I and {sup 103}Pd 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 {sup 125}I or {sup 103}Pd 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 {sup 125}I and {sup 103}Pd 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 are 129, 139, 150 and 161 Gy for {sup 125}I and 103, 112, 122 and 132 Gy for {sup 103}Pd 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 {sup 125}I and 125, 135, 145 and 155 for {sup 103}Pd 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.

Li, X Allen [Department of Radiation Oncology, University of Maryland, School of Medicine, 22 South Greene Street, Baltimore, MD 21201-1595 (United States); Wang, Jian Z [Department of Radiation Oncology, University of Maryland, School of Medicine, 22 South Greene Street, Baltimore, MD 21201-1595 (United States); Stewart, Robert D [School of Health Sciences, Purdue University, West Lafayette, IN 47907-1338 (United States); Di Biase, Steven J [Department of Radiation Oncology, University of Maryland, School of Medicine, 22 South Greene Street, Baltimore, MD 21201-1595 (United States)

2003-09-07

171

Monte carlo simulation of dosimetric parameters for the model 6711 125I brachytherapy source  

International Nuclear Information System (INIS)

The ?-radioactive seed brachytherapy source has been widely employed in the implantation therapy for the prostatic carcinoma and the ophthalmic lesions.In this study the dosimetric parameters for characterization of a low-energy interstitial brachytherapy source 125I were calculated according to dose calculation formalism recommended by AAPM TG-43U1. For data processing, a 0.28 cm active length was used for the geometry function. The dosimetry parameter air-Kerma strength, dose rate constant, radial dose function and anisotropy function were estimated by means of the EGS5 Monte Carlo code. The results obtained from this study are in good agreement with the corresponding values recommended by TG-43U1 and with the data reported by Dolan, et al. (authors)

172

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

173

Recovery of 125I-thyroxine and ribonuclease solutes  

International Nuclear Information System (INIS)

Adsorption losses onto surfaces of complex solutes functioning as analytes or reagents in chemical analysis eventually become a major problem as the amount of solute decreases to lower levels. This problem is one of the most important ones now facing ultratrace (below the ng level) organic and biological analysis. A better understanding and control of adsorption losses of ultratrace solutes onto surfaces is needed. This thesis investigates the recovery of two representative complex solutes from surfaces. The first solute is 125I-thyroxine, which is subjected to a soluble affinity chromatography technique potentially useful for sample cleanup at the ultratrace level. The recovery of 125I-thyroxine at the low pg level as a model analyte is optimized throughout several steps. Ribonuclease is the second ultratrace solute investigated with emphasis on the preparation and characterization of carrier ribonuclease as an inactive analog of the native enzyme. This carrier ribonuclease is successful, allowing an assay for ribonuclease to be extended from the mid to low pg level. The usefulness of this reagent is limited, however, by the presence of residual trace ribonuclease that itself has novel properties and is also characterized

174

125I iothalamate an ideal marker for glomerular filtration  

International Nuclear Information System (INIS)

The triiodinated angiographic contrast medium, iothalamate (usually labelled 125I), has been used extensively as a marker for glomerular filtration. The authors have studied the renal handling of 125I iothalamate (IOT) in vivo and in vitro in several species. In renal cortical slices from chicken, rabbit, rat, and monkey, the tissue-to-medium ratio of IOT was twice that of 51Cr-EDTA (EDTA) at 37 degrees C; a difference that was abolished at 0 degree C and markedly reduced by added o-iodohippurate or iodipamide. In five chickens the steady-state renal clearance of IOT (CIOT) was twice that of EDTA (CEDTA) or 3H inulin (C1); a difference that was abolished by administration of 100 mg/kg/hr of novobiocin, an organic anion transport inhibitor. CEDTA was similar to C1 before as well as after transport inhibition. Utilizing the Sperber technique the mean apparent tubular excretion fraction (ATEF) of IOT was 8%, while that of EDTA was 1%. After novobiocin coinfusion (new steady-state) ATEFIOT was significantly reduced and not different from that of EDTA (-1%). In the same animals the total urinary recovery of IOT was 84 and 57% before and after novobiocin, respectively, while corresponding values for EDTA was unchanged by the inhibitor. In seven rats the renal extraction of IOT was reduced from 29 to 17% by coinfusion of probenecid (5 mg/kg/hr). Corresponding extractions were 82 to 34% and 22% (unchanged) for PAH and EDTA, respectively

175

Radioactive labelling with 125 I of infectious pancreatic necrosis virus  

International Nuclear Information System (INIS)

In order to understand the interaction between a cellular receptor and a ligand the photochemical crosslinking method has been widely used. This method has been utilized as an approach to determine the presence or absence of virus receptors in susceptible cells. Successful detection of crosslinks is achieved if one of the components, in the crosslinked product, has been radioactively labeled. The incorporation of a radioactive isotope, in the virus-receptor complex, enables the identification of the receptor. To undertake this study in the future, in this communication the radioactive labeling of virus particles is presented. The infectious necrosis pancreatic virus (IPN virus) was the chosen moiety to be in vitro labeled with 125 I using a direct method. Three oxidizing agents were used in the iodination procedure for comparison: an enzyme, lactoperoxidase and two chemical reagents, N-Chloro-benceno-sulfonamide (Iodo-Beads) and 1,3,4,6-Tetra chloro-3a,6a-diphenyl glycouril (Iodo-Gen). The results are analysed to select the method which guarantee the incorporation of 125 I in the viral capsid protein, while preserving its full infectivity. (author)

176

Response of LiF-TLD micro-rods around 125I radioactive seed  

International Nuclear Information System (INIS)

The EGSnrc Monte Carlo system has been used to calculate the energy response of LiF-TLDs of different sizes around 125I permanent brachytherapy sources. The source model includes the effects of an encapsulation, self-absorption within the source and in the welded ends of the encapsulation. The LiF-TLD material has cylindrical geometry (micro-rod) with diameters ranging from 1 mm to 5 mm and a length of 6 mm. The energy response factor for a LiF-TLD calibrated in 60Co gamma-rays and then irradiated by an 125I permanent brachytherapy source varies between 1.32 ± 0.2% (1 SD) and 1.406 ± 0.2% (1 SD) for 5 mm and 1 mm diameter micro-rods, respectively. The energy response factor depends on the radius and the polar angle of the measurement point. For a LiF-TLD of diameter 1 mm calibrated at 1 cm on the transverse axis of the 125I source in water, the energy response factor decreases by a maximum of 3.5% within the 6 cm x 6 cm x 6 cm calculation region. For the 5 mm diameter LiF-TLD, the energy response factor decreases by a maximum of 5% in the same region. An examination of the photon energy spectra showed that the photon spectrum does not change significantly in water within the 3D calculation region (6 cm x 6 cm x 6 cm). The mass energy absorption coefficient ratio of water to LiF-TLDs does not vary by more than 0.5% in this calculation grid. The results, however, show that there is a change in the photon spectrum with distanhange in the photon spectrum with distance from the source and with polar angle for LiF-TLDs. This difference in the energy spectrum gives rise to a difference in the mass energy absorption coefficient ratio of water to LiF (calculated by taking into account the difference in photon fluence in water and LiF) and that calculated assuming that the photon spectrum in water and in the LiF-TLD is identical

177

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

Energy Technology Data Exchange (ETDEWEB)

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

178

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

International Nuclear Information System (INIS)

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)

179

Exclusive curietherapy by permanent iodine-125 implants: selection of patients and results after eight years; Curietherapie exclusive par implants permanents d'iode-125: selection des patients et resultats a huit ans  

Energy Technology Data Exchange (ETDEWEB)

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

Boutenbat, G.; Peiffert, D.; Bernier, V.; Moreau, J.L.; Boudran, G.; Noel, A.; Marchesi, V.; Huget, S. [Centre Alexis Vautrin, 54 - Vandoeuvre-Les-Nancy (France); Moreau, J.L. [Cabinet prive d' urologie, 54 - Nancy (France); Boudran, G. [Centre Hospitalier Universitaire de Brabois, 54 - Vandoeuvre-Les-Nancy (France)

2010-10-15

180

Tissue distribution of 125I-iRNA in liposome after intravenous injection in mice  

International Nuclear Information System (INIS)

The liposome containing 125I-iRNA of large unilamellar vesicles were prepared by the reverse phase evaporation method, with the encapsulation efficiency ranging from 32.5% to 38.2%. Through observation of 125I labelled iRNA after i.v. injection, the comparative distribution of iRNA in some of the chief organs in mice, including 125I-iRNA entrapped in liposome or free 125I-iRNA, was determined. The results showed that the spleen and the liver had high liposome uptake. The interaction time of iRNA in mice was increased with liposome containing 125I-iRNA

 
 
 
 
181

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

182

Standardisation of 125I using seven techniques for radioactivity measurement  

International Nuclear Information System (INIS)

Seven methods of radioactivity measurement were used to standardise an 125I solution within the frame of an international key comparison organised by BIPM: photon-photon coincidence counting with two NaI detectors, photon sum-peak counting in a NaI well detector and in a 4? CsI(Tl) sandwich spectrometer, total emission counting in a windowless 4? CsI(Tl) sandwich spectrometer, electron-X,? coincidence counting and electron-X,? sum counting in a pressurised proportional counter inside a NaI well detector and liquid scintillation counting with the CIEMAT/NIST method. The solid sources were prepared by quantitative drop deposition with addition of AgNO3. The measurement methods, the results and the applied corrections are described and discussed

183

[Evaluation of patients' satisfaction after breast reconstruction with latissimus dorsi myocutaneous flap and immediate permanent breast implant].  

Science.gov (United States)

Current surgical treatment modalities for breast reconstruction include latissimus dorsi mycotaneous flap with immediate permanent breast implant (LDI). The aim of the present study was to analyze reconstruction with LDI in terms of quality of life, cosmesis and patient satisfaction. A chart analysis was carried out with the first ten patients who underwent breast reconstruction with LDI. The patients were interviewed and self-assessment quality of life was administered. They also underwent assessment of satisfaction and cosmesis. The high satisfaction and cosmesis scores in the breast reconstruction group indicate the superior results that can be achieved with breast reconstruction. PMID:24747404

Bognár, Gábor; G?gh, Bettina; Novák, András; István, Gábor

2014-04-01

184

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

185

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

186

An improved synthesis of [125I]N-(diethylaminoethyl)-4-iodobenzamide: a potential ligand for imaging malignant melanoma  

International Nuclear Information System (INIS)

To improve the radiolabeling yield and the specific activity of [125I]N-(2-diethylaminoethyl)-4-iodobenzamide(DAB), the aryltributyltin precursor was synthesized from the N-(2-diethylaminoethyl)-4-bromobenzamide derivative by palladium catalyzed stannylation using bis(tributyltin). The radiolabeled product, [125I]DAB, was obtained by an iododestannylation reaction in high radiochemical yields (85-94%, radiochemical purity, > 98%) using chloramine-T as an oxidizing agent. The specific activity was greater than 1600 Ci/mmol. The biodistribution studies in nude mice implanted with human malignant melanoma xenograft showed a good tumor uptake (6.14% ID/g at 1 h, 2.81% ID/g at 6 h and 0.42% ID/g at 24 h) of [125I]DAB. Unfortunately, a high uptake in the non-target organs, such as liver and lung was found. At 1 h post-injection the activity level in liver and lung was 11.76 and 7.58% ID/g, respectively. A slow clearance of activity from liver and lung was observed at 6 h (3.43 and 0.49% ID/g). These results demonstrate that iodinated IDAB is a potential radiopharmaceutical for the management of patients with malignant melanoma. (Author)

187

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 | Language: Portuguese 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

188

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

189

125I-LSD: a high sensitivity ligand for serotonin receptors  

International Nuclear Information System (INIS)

125I-labeled receptor ligands offer unique advantages over their 3H-labeled counterparts. Carrier-free 125I-labeled ligands can be synthesized with specific activities of up to 2170 Ci/mmol while (mono) tritium labeled ligands are limited to 29 Ci/mmol. Therefore, 125I-labeled ligands can be approximately 70-fold more sensitive than 3H-labeled ligands in detecting receptor sites. In addition, 125I-labeled ligands emit relatively energetic X-rays and ?-rays which are readily detected by gamma counting equipment. The authors report here the serotonergic binding properties of 125I-LSD the first reported 125I-labeled ligand for serotonin receptors. (Auth.)

190

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.)

191

Binding and degradation of [125I]human growth hormone in rat adipocytes  

International Nuclear Information System (INIS)

Iodinated human growth hormone [( 125I]hGH) binds to both specific and nonspecific sites on the surface of adipocytes isolated from the epididymal fat of normal rats. When adipocytes were incubated at 37 C with 1 nM [125I]hGH, specific binding increased for 30-60 min and thereafter remained approximately constant as long as the hormone was present in the medium. About 90% of the 125I released was soluble in 5% trichloroacetic acid and was in the form of iodotyrosine. The rate of 125I release from specific binding sites decreased by a factor of 4 when the temperature was lowered from 37 to 17 C. Replacement of some of the sodium chloride in the buffer with 25 mM ammonium chloride had little or no effect on the amount on 125I that bound to cells when [125I]hGH was present in the medium, but completely blocked the release of 125I from cells transferred to hormone-free medium. Ammonium chloride also significantly reduced both the release of 125I from nonspecific binding sites and the amount of 125I recovered in trichloroacetic acid-soluble form. Cloroquine, leupeptin, or colchicine nearly doubled the specific binding of [125I]hGH after 180 min and markedly slowed the release of 125I when cells were transferred to hormone-free medium. All of these agents also significantly reduced the rate of release of 125I from nonspecific binding sites. Incubation of adipose tissue from hypophysectomized rats with ammonium chloride, leupeptin, or colchicine failed to alter the ability of GH to increase glucose oxidation, induce refractoriness, or promote lipolysis in the presence of theophylline

192

Substantiation of application of 125I sealed sources to interstitial radiothrapy  

International Nuclear Information System (INIS)

Substantiation of application of sealed sup(125)I sources to radiotherapy of small volume neoplasms. Sup(125)I are in titanium capsules sealed by pulse laser welding. Experimental models are neoplasms in mice mammary glands. Radiation doses to irradiated volume from point sup(125)I source depending on distance from and activity of the source are calculated as well as distances in tissue - equivalent medium corresponding to the doses from sup(125)I point souce (10-200 Gy) depending on source activity. Experimental results point out on practical correspondence of depth and extent of radiation injury of neoplasm tissue to calculated dose field in tissue - equivalent medium

193

Biodistribution of 125I labeled recombinant macrophage migration inhibitory factors in inflammatory model of mice  

International Nuclear Information System (INIS)

To evaluate 125I labeled recombinant macrophage migration inhibitory factors (rMIF) for the scintigraphic imaging of inflammation, rMIF was labeled with 125I by Iodo- gen method. 125I-rMIF was isolated by Sephadex G25 column. The stability, immune specificity of 125I-rMIF and its biodistribution in inflammatory model of mice were studied. The labeling yield of 125I-rMIF was 96.5%. It was stable within 48 h at room temperature. The biodistribution results showed that the 125I-rMIF was metabolized by the liver, the radioactivity clearance mainly happened in the kidney and the speed of the blood clearance was rapid. After caudal vein iniection with 125I-rMIF, the ratio of radioactivity uptake between inflammatory limb (target) and contra lateral healthy limb (non target)(T/NT) were 1.42, 1.35, 2.18 and 2.05 at 0.5, 1, 6, 24 h respectively. 125I-rMIF had the capability of locating the inflammatory foci. The advance of it is more obviously at the late stage than that at the early stage. 125I-rMIF may be a potential agent for the diagnosis of concealed and subacute inflammatory disease. (authors)

194

Pharmacokinetics of the in vivo distribution of 125I-TSH  

International Nuclear Information System (INIS)

A study of 125I-TSH pharmacokinetics in mice was performed in order to obtain more information on the peripheral tissues rich in thyrotropin receptors. By comparison with Na 125I-biodistribution, it was shown that 125I-TSH pharmacokinetics are quite different of that of free radioiodine. After 125I-TSH injection, an increased uptake is seen in thyroid, brain, eyes, pancreas and intestine and the pharmacokinetics of the radioactivity in these organs do not follow blood clearance. The results suggest thyrotropin receptors to be present in the above organs. (Author)

195

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

International Nuclear Information System (INIS)

Venous thrombosis is routinely diagnosed by the injection of around 3.7 MBq 125I-fibrinogen. 125I- is released from degrading 125I-fibrinogen (biological half-life approximately 4 days). About 300 mg KI is given daily for 1-2 weeks after the injection to prevent uptake of 125I- in the thyroid. The effects of such a ''blocking'' regime on the thyroid uptake using a 124 mm (diam) x 1.5 mm NaI(Tl) detector were studied. Accurate determinations of the 125I activity in the thyroid were carried out using coincident registrations of two 28 keV photons from the 125I decay. The accuracy in the determinations of the absolute activity was better than 10%, the reproducibility of measurements on the same patient being +-2%. From thyroid measurements 1-2 days after the injection (when the thyroid uptake of 125I can be neglected) the relation between the counting rate from activity circulating outside the thyroid and over the arm was derived and then used for background correction. The contribution from extra thyroid activity was then carefull). estimated from subsequent measurements of the thyroid. It was concluded that it is possible to make accurate determinations of the 125I uptake in the thyroid usinn coincident registrations of two 28 keV photons from the 125I decay and that 300 mg KI given daily gives a very good ''blocking'' effect. (H.K.)

196

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)

197

Monte Carlo radiation dose simulations and dosimetric comparison of the model 6711 and 9011 {sup 125}I brachytherapy sources  

Energy Technology Data Exchange (ETDEWEB)

Smaller diameter brachytherapy seeds for permanent interstitial implantation allow for use of smaller diameter implant needles. The use of smaller diameter needles may provide a lower incidence of healthy-tissue complications. This study determines the brachytherapy dosimetry parameters for the smaller diameter source (model 9011) and comments on the dosimetric comparison between this new source and the conventional brachytherapy seed (model 6711).

Rivard, Mark J. [Department of Radiation Oncology, Tufts Medical Center, Boston, Massachusetts 02111 (United States)

2009-02-15

198

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.

199

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

200

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

 
 
 
 
201

[{sup 125}I]{beta}-CIT-FE and [{sup 125}I]{beta}-CIT-FP are superior to [{sup 125}I]{beta}-CIT for dopamine transporter visualization: Autoradiographic evaluation in the human brain  

Energy Technology Data Exchange (ETDEWEB)

The binding of the three dopamine transporter radioligands ([{sup 125}I]{beta}-CIT, [{sup 125}I]{beta}-CIT-FE, and [{sup 125}I]{beta}-CIT-FP) was studied using whole-hemisphere autoradiography on postmortem human brains. The autoradiograms revealed an intense and homogeneous labeling of the nucleus caudatus and putamen but also to varying extent to serotonergic and noradrenergic transporters of neocortex and thalamus. The order of specificity estimated (striatum over neocortex ratios) was {beta}-CIT-FP > {beta}-CIT-FE >> {beta}-CIT, suggesting that {beta}-CIT-FE and {beta}-CIT-FP should be preferred for in vivo studies of the dopamine transporter in the human brain.

Guenther, Ilonka; Hall, Haakan; Halldin, Christer; Swahn, Carl-Gunnar; Farde, Lars; Sedvall, Goeran

1997-10-01

202

Radiobiology for eye plaque brachytherapy and evaluation of implant duration and radionuclide choice using an objective function  

International Nuclear Information System (INIS)

reduced prescription doses. Objective functions were created to evaluate the BEDVHs as a function of R and T. These objective functions are mathematically accessible and sufficiently general to be applied to temporary or permanent brachytherapy implants for a variety of disease sites. Results: Reducing T from 7 to 0.01 days for a 10 mm plaque produced an average BED benefit of 26%, 20%, and 17% for 103Pd, 125I, and 131Cs, respectively, for all P; 16 and 22 mm plaque results were more position-dependent. 103Pd produced a 16%–35% BED benefit over 125I, whereas 131Cs produced a 3%–7% BED detriment, independent of P, T, and plaque size. Additionally, corresponding organ at risk physical doses were lowest using 103Pd in all circumstances. Conclusions: The results suggest that shorter implant durations may correlate with more favorable outcomes compared to 7 day implants when treating small or medium intraocular lesions. The data also indicate that implant duration may be safely reduced if the prescription physical dose is likewise diminished and that 103Pd offers a substantial radiobiological benefit over 125I and 131Cs irrespective of plaque position, implant duration, and tumor size.

203

Changes in cell cycle, apoptosis and necrosis following the establishment of a 125I brachytherapy model in the spinal cord in Banna mini-pigs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Brachytherapy is regarded as the most effective method in the treatment of metastatic spinal tumors since little damage is caused to surrounding healthy tissue. However, this method may cause radiation myelopathy if an overdose occurs. In the present study, we established a Banna mini-pig 125I spinal cord implantation model to provide a tool for the study of how to reduce these types of side effects. Cell cycle alteration, apoptosis and necrosis of spinal cord neurons in the presence of vario...

Yang, Zuozhang; Jin, Congguo; Chen, Ting; Sun, Hongpu; Yang, Dakuan; Huang, Yunchao; Zhang, Jin; Zhao, Ruilian; Zhang, Jinlei

2012-01-01

204

Preparation, purification and characterization of 125I-glucagon used for radioimmunoassay  

International Nuclear Information System (INIS)

A method for the radioactive labelling of glucagon with Na125I with the help of chloramine T for the use in radioimmunoassay is described. The purification of 125I-glucagon with polyacrylamide gel electrophoresis, the characterization of the tracer, its stability and the immunological properties are described. (author)

205

Comparative biological effectiveness of 125I and 131I in experiments on rats  

International Nuclear Information System (INIS)

In experiments on rats, a study was made of the metabolism status, according to some of the biochemical indices, after administration of different amounts of 125I and 131I. A similar direction of metabolic changes and a comparatively equal biological effectiveness of 131I and 125I were demonstrated when the radionuclides were administered in the form of sodium salt

206

Labelling monoclonal antibody 10D9 with 125I using the iodogen method  

International Nuclear Information System (INIS)

To establish the method radiolabeled monoclonal antibody 10D9 against human costimulatory molecules CD80 with 125I, 10D9 was labeled with 125I using the Iodogen method at room temperature. The labeling efficiency and radiochemical purity were tested with TCA, and the immune activity and stability of the labeling product were analyzed. The optimum labeling condition was 10 ?g Iodogen, 20 ?g 10D9 and 22.2 MBq Na125I. The reaction time was 8 min at room temperature. The labeled yield was (84.10±3.18)%, and the radiochemical purity was (98.49±1.14)%. The radio-activity of 125I-10D9 was 933.51 MBq/mg. The specific binding efficiency of 125I-10D9 with Daudi cell was(23.21±1.14)%. The radiochemical purity of 125I-10D9 was over 90% after three weeks of mixing with PBS. In conclusion, the method is simple and easy to perform. The labeling efficiency and radiochemical purity is high. The stability of 125I-10D9 is fine in vitro and 125I-10D9 keeps its immune activity after Iodogen labeling. (authors)

207

5-[125I]iodo-2'-deoxyuridine in the radiotherapy of pancreatic cancer in mice  

International Nuclear Information System (INIS)

Objective: To investigate the distribution, therapeutic effect and safety of 5-[125I-iodo-2'-deoxyuridine (125I-UdR) in Balb/c nude mice bearing pancreatic cancer. Methods: After 125I-UdR was intratumourally injected, the distribution of 125I-UdR was estimated by SPECT scintigrams and the radioactivity of various organs was determined by ? well counter, the antineoplastic capabilities was demonstrated through estimating the gross pathological and cellular changes of tumour, as well as analyzing the survival rate; and the pharmic safety was evaluated by using hemogram, marrow cell and flow biochemistry indexes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr). Results: (1) intratumourally injected 125I-UdR was retained within the tumour tissue without serious leakage. (2) 125I-UdR could damage cancerous cell and distinctly extended the survival of tumour-bearing mice. (3) The changes of hemogram and biochemistry indexes were not observed, but the proliferation of marrow cells was suppressed within a short period (30 d) after intratumoral injection of 125I-UdR. Conclusion: 125I-UdR can selectively kill proliferative tumour cells, and distinctly extend the survival of tumour-bearing mice, but the proliferation of marrow cells is suppressed within a short period

208

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.)

209

Pharmacokinetics of 125I-recombinant human thrombopoietin in rats after i.v  

International Nuclear Information System (INIS)

Purpose of this work is to establish the analytic method and investigate the pharmacokinetics of 125I-rhTPO in rats receiving single injection of vein. 125I-rhTPO was prepared with Iodogen method. The radiochemical purity of 125I-rhTPO was determined both by HPLC and SDS-PAGE. In the test, 125I-rhTPO was injected via caudal vein at the dose of 2 ?g·kg-1 in rats. Blood samples were collected at different time after i.v., then the drug concentration was determined according to the radioactivity and the pharmacokinetic parameters were calculated. It is shown that radiochemical purity of 125I-rhTPO was above 98%, and the pharmacokinetics of 125I-rhTPO following i.v. with 2 ?g·kg-1 in rats was fit to two-compartment model. The T1/2(?) was (1.32 ± 0.35) h, T)1/2(?) was (24.55 ± 1.07) h and AUC0?t was (134.26 ± 22.99) ng·h·mL-1. 125I-rhTPO prepared with Iodogen method was accordant with original rhTPO at purity and molecular weight by SDS PAGE test. The stability of 125I-rhTPO was good in vitro. Half-lives were about 25 h. (authors)

210

Measurement of 125I K x and 35.5 keV photon emission probabilities  

International Nuclear Information System (INIS)

The K x ray and 35.5 keV gamma-ray emission probabilities of 125I has been determined. The photon spectra were measured with HP-Ge detector. The activity of 125I sources were measured by means of x-x, ? coincidence method using of fast-slow coincidence spectrometer. (author)

211

Effect of gold shielding on the dosimetry of an 125I seed at close range  

International Nuclear Information System (INIS)

Radioactive 125I plaques with gold shields have been used for the treatment of choroidal melanoma. The effect of the gold shield on the dosimetry of a single 125I seed (model 6711) has been investigated in this paper. Increases in dose at close range due to the presence of the shield are observed. Such enhancement is in agreement with Williamson's Monte Carlo calculations

212

Kinetics of micronucleus induction by 125I-labelled thyroid hormone in hormone-responsive cells  

International Nuclear Information System (INIS)

Two cell lines, CHO and GC, different in their tissue origin, were investigated with the aim of discovering the correlation between the level of 225I-T3 binding and chromosomal damage induced by 125I decay. A model of T3 receptor-dependent dose delivery to nuclei of GC cells continuously incubated with 125I-T3 is proposed. The frequency of micronuclei in the CHO cell line continuously incubated with 125I-T3 did not differ significantly from controls, whereas in the pulse-chase schedule the mean frequency of micronucleated binuclear cells was lower during 4 post-labelling doubling times than in controls. Incubation of GC cells with various activity concentrations in medium for four cell cycles resulted in a linear increase of 125I activity in cells and nuclei. The frequency of binuclear cells bearing micronuclei was linearly dependent on the nuclear 125I-T3 concentration. (Author)

213

N-(m-[125I]iodophenyl)maleimide: an agent for high yield radiolabeling of antibodies  

International Nuclear Information System (INIS)

In an effort to radiolabel antibodies, N-(m-[125I]iodophenyl)maleimide (m-[125I]IPM) was prepared by the demetallation of an N-[m-tri-(n-butyl)stannylphenyl]maleimide intermediate. The unlabeled intermediate was synthesized in ? 75% yield using a palladium catalyzed reaction of hexabutylditin with m-bromoaniline, followed by reaction with maleic anhydride and ring annulation. All products were confirmed by NMR and elemental analysis. Labeling with 125I was carried out in a biphasic mixture containing chloramine-T (radiochemical yield ? 70%). Rabbit IgG modified with the heterobifunctional crosslinking agent N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) and bovine serum albumin were conjugated with m-[125I]IPM (yield: 40 and 80%, respectively). In addition, m-[125I]IPM was conjugated to rabbit IgG subunits (HL) in 70% yield. The in vitro stability of the radiolabeled proteins in serum showed < 1% deiodination over 24h. (author)

214

Combination of bilateral pelvic lymphadenectomy, permanent iodine-125 implantation, and percutaneous irradiation of the locally confined prostatic cancer. Pt. 1  

International Nuclear Information System (INIS)

Since the beginning of 1981, 32 patients at an age of 52 to 72 years who suffered from a locally confined adenocarcinoma of the prostate were treated by permanent implantation of I-125 seeds. 25 patients were evaluated after a median observation period of 30 months. The first group consisting of 19 patients was submitted to a combined percutaneous and interstitial treatment, the other 6 patients were initially treated only by interstitial therapy because of severe complications observed in the meantime. After bilateral pelvic staging lymphadenectomy, permanent I-125 seeds were implanted into the patients of stage T1, T2, early T3 and pN0-1, in case of microscopic lymph node manifestation without capsular perforation also into patients of stage pN2 and pN4. 8 weeks later the patients received a moving beam irradiation with 10 MV photons at the linear accelerator. The centre of the prostate was faded out by a specially constructed H absorber in such a way that the prescribed target dose of 36 Gy in 4 weeks to the 90%-isodose was only applied to a spherical surface around the implant. 1 patient died perioperatively from an embolism due to phlebothrombosis of the thigh. 22 out of the other 24 patients are in complete remission, 1 patient had a local recurrence in the right seminal vesicle which appeared 28 months after primary therapy, and 1 patient developed skeletal metastases. The objective side effects al metastases. The objective side effects and late complications of our combined treatment are considerable with respect to their incidence as well as their severity: a slight or medium radioproctitis was found after a latent period of 1 to 2 years in 28% (5/18) of cases, after a latent time of about 1 1/2 to 2 years another 28% (5/18) developed subsequently to a proctitis an urethral stricture and an ulcer situated on the anterior rectum wall facing the prostate, and 4 patients presented finally a prostato-rectal fistula. (orig.)

215

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

216

Isolation of 125I-concanavalin A-labeled plasma membrane from unfertilized mouse eggs  

International Nuclear Information System (INIS)

A procedure was developed for isolation of plasma membrane (PM) preparations from unfertilized mouse eggs. Zona-free mouse eggs prepared by the method of Boldt and Wolf (Gamete Res 13:213-222, 1986) were labeled with 125I-concanavalin A (ConA) prior to sonication and fractionation on iso-osmotic self-generated Percoll density gradients. Experiments using the ConA-specific sugar alpha-methylmannoside (alpha MM) indicated that 125I-ConA bound specifically to the egg PM. Greater than 95% of 125I-ConA binding to zona-free eggs was blocked in the presence of 0.1 M alpha MM, and incubation of eggs in alpha MM after 125I-ConA labeling caused release of 85-90% of bound label. Fractionation of 125I-ConA-labeled eggs by Percoll density gradient centrifugation yielded a single radioactive peak at density = 1.025, corresponding to egg PM material. Prolonged incubation of 125I-ConA-labeled eggs or egg sonicates prior to fractionation did not alter the location of the radioactive peak, indicating that 125I-ConA did not label other organelles. As a control, human erythrocytes were labeled with 125I-ConA and fractionated under identical experimental conditions and yielded a single radioactive peak at density (1.020) comparable to that observed for 125I-ConA-labeled eggs. These results indicate that 125I-ConA can be used as a specific marker to support PM isolation from small numbers of zona-free mouse eggs

217

The brachytherapy by implants of iodine 125 in the localised prostate cancer; La curietherapie par implants permanents d'iode 125 dans le cancer de la prostate localise  

Energy Technology Data Exchange (ETDEWEB)

The brachytherapy by permanent iodine 125 implants is in the localised prostate cancer a clinical treatment well tolerated and characterized by a limited toxicity: the urinary flow before implantation is an important factor of evolution prediction of the acute urinary toxicity, especially with regard to acute urinary retention. The important number of gains implanted near urethra is responsible of the acute urinary toxicity. All patients were in a state of complete remission with a decrease in the concentration of serum P.S.A. to eight months. (N.C.)

Cecconi, A.; Guido, A.; Vicenzi, L.; Galuppi, A.; Barbieri, E. [U.O. Radioterapia, Policlinico S.-Orsola-Malpighi, Bologne (Italy)

2007-11-15

218

Isotope and Patient Age Predict for PSA Spikes After Permanent Prostate Brachytherapy  

International Nuclear Information System (INIS)

Purpose: To evaluate prostate-specific antigen (PSA) spikes after permanent prostate brachytherapy in low-risk patients. Methods and Materials: The study population consisted of 164 prostate cancer patients who were part of a prospective randomized trial comparing 103Pd and 125I for low-risk disease. Of the 164 patients, 61 (37.2%) received short-course androgen deprivation therapy. The median follow-up was 5.4 years. On average, 11.1 post-treatment PSA measurements were obtained per patient. Biochemical disease-free survival was defined as a PSA level of ?0.40 ng/mL after nadir. A PSA spike was defined as an increase of ?0.2 ng/mL, followed by a durable decline to prespike levels. Multiple parameters were evaluated as predictors for a PSA spike. Results: Of the 164 patients, 44 (26.9%) developed a PSA spike. Of the 46 hormone-naive 125I patients and 57 hormone-naive 103Pd patients, 21 (45.7%) and 8 (14.0%) developed a PSA spike. In the hormone-naive patients, the mean time between implantation and the spike was 22.6 months and 18.7 months for 125I and 103Pd, respectively. In patients receiving neoadjuvant androgen deprivation therapy, the incidence of spikes was comparable between isotopes (125I 28.1% and 103Pd 20.7%). The incidence of spikes was substantially different in patients 125I and/or <65 years of age. Differences in isotope-related spikes are most pronounced in hormone-naive patients

219

Implantation of permanent jugular catheters in patients on regular dialysis treatment: ten years' experience.  

Science.gov (United States)

Dual-lumen cuffed central venous catheter proved an important alternative vascular access compared to conventional arteriovenous (Cimino-Brescia) shunt in a selected group of patients on regular dialysis treatment. Typically, these catheters are used as bridging access, until fistula or graft is ready for use, or as permanent access when an arteriovenous fistula or graft is not planned (NKF-DOQI). We conducted a prospective study on IJV permanent catheter insertion and its related earlier and long-term complications. From February 1991 to February 2001 we inserted in 124 patients in end stage renal disease 135 cuffed catheters (130 in the right IJV and 5 in the left IJV), 92 of which were Permcath, 27 Vascath, and 16 Ash-Split. We performed the insertion of catheters by puncturing the IJV under ultrasonographic guid-ance in the lower side of the Sedillot triangle and checking the accurate position of the tip by endocavitary electrocardiography (EC-ECG). The duration of catheter use was from 60 to 1460 days, mean 345 days. The actuarial survival rate at 1 year was 82%, at 2 years 56%, at 3 years 42% and at 4 years 20%. The exit site infection and septicemia rates were 5.2 and 2.86 per 1000 catheter days respectively. Catheter sepsis was implicated in the death of three patients, all of whom had multiple medical problems. Several episodes of thrombosis (6% of dialyses) occurred which required urokinase treatment, and catheter replacement in 12 patients (9.6%). In 3 cases the catheters were displaced and correct repositioning was performed. Two catheters (Ash-Split) were replaced due to accidental damage of the external portion of catheters (alcoholic disinfectant). Catheter tip embolism occurred on one occasion during elective catheter exchange over guide-wire. One of the common problems encountered with cuffed tunneled catheters is poor blood flow, most often secondary to the formation of a fibrin sheath around the lumen. Even if we conducted a non-randomized study, in our experience, the higher rate of malfunctioning catheters was in the group with no anticoagulation therapy. Therefore, we suggest anticoagulation treatment in all patients wearing central vascular catheters with no contraindication. Just one year ago, we followed NKF-DOQI clinical practice guidelines for vascular access that indicated that for patients who have a primary AV fistula maturing, but need im-mediate hemodialysis, tunneled cuffed catheters are the access of choice and the preferred insertion site is the right IJV. Considering recent reports of permanent central venous stenosis or occlusion after IJV can-nulation, currently, our first choice is femoral vein cannulation with smooth silicone rubber catheters, tunneled if long-term utilization is needed (more the 3-4 weeks). In our opinion, the right IJV puncture is to be avoided as much as the venipuncture of arm veins suitable for vascular access placement, particularly the cephalic vein of the non-dominant arm. Our data confirm that permanent venous catheters might rep-resent an effective long-term vascular access for chronic hemodialysis, particularly for older patients with cardiovascular disease and for cancer patients. PMID:17638264

Ervo, S; Cavatorta, F; Zollo, A

2001-01-01

220

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

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

Shiraishi Yutaka

2011-10-01

 
 
 
 
221

Effect of random seed placement error in permanent transperineal prostate seed implant  

International Nuclear Information System (INIS)

Background and purpose: Random seed placement error may adversely effect dose distribution in transperineal prostate seed implants. In this study, we investigated the extent to which individual seed activity influences dose-distribution degradation due to random seed placement error. Patients and methods: Separate initial treatment plans were prepared for three prostate sizes, 27.3, 43.2 and 48.9 cc, using 0.35, 0.55 and 0.75 mCi iodine-125 seeds. All stated activities are understood to be apparent activities. The combinations produced a total of nine treatment plans. Each initial treatment plan was subjected to 1000 stochastic three-dimensional Gaussian perturbations of seed location, with a standard deviation of 4 mm for a total of 9000 treatment plans. The resulting plans were evaluated for target coverage and urethra involvement. Results: Satisfactory initial treatment plans were prepared for all prostate sizes and seed activities. All 9000 perturbed treatment plans showed acceptable target coverage under the D90/90 criterion. Some of the perturbed plans for the 27.3 and 43.2 cc prostates with 0.55 and 0.75 mCi seeds failed the V100/90 criterion. Some of the randomly perturbed seed distributions showed significantly increased doses to the urethra relative to the unperturbed treatment plan. This effect was more pronounced with greater seed activity. Conclusions: There may be a higher probability of unfavorable target coverage due to random seed placement error when performing transperineal iodine-125 prostate seed implants using seeds with activity greater than 0.35 mCi. There may also be a higher probability of unfavorable urethra involvement when using higher activity seeds

222

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

Energy Technology Data Exchange (ETDEWEB)

A carrier-free radioiodinated cocaine photoaffinity label, (-)-3-({sup 125}I)iodo-4-azidococaine (({sup 125}I)IACoc), has been synthesized and used as a probe for cocaine-binding proteins. Photoaffinity labeling with 0.5 nM ({sup 125}I)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. ({sup 125}I)IACoc labeling of the 26-kDa polypeptide was also inhibited by 10 {mu}M imipramine, amitriptyline, fluoxetine, benztropine, and tetrabenazine. The size of the ({sup 125}I)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-({sup 3}H)DTG. Kinetic analysis of ({sup 125}I)IACoc binding to rat liver microsomes revealed two sites with K{sub d} 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, ({sup 125}I)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.

Kahoun, J.R.; Ruoho, A.E. (Univ. of Wisconsin, Madison (United States))

1992-02-15

223

(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

224

Complicaciones del implante de marcapaso definitivo: ¿Un evento operador dependiente? Análisis de 743 pacientes consecutivos / Complications of permanent pacemaker: Event operator dependent? Analysis of 743 consecutive patients  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish La frecuencia de complicaciones relacionadas al implante de marcapasos, es variable y se encuentra entre 6% a 9 %, y existen diferentes factores relacionados con las mismas. Objetivos: Evaluar las distintas complicaciones relacionadas con el implante de marcapasos y determinar cuáles son los factore [...] s de riesgo independientes que las predisponen. Métodos: Análisis descriptivo, tipo casos-controles, retrospectivo y prospectivo, correspondiente a 743 consecutivos, con implante de marcapasos definitivo, entre enero de 2007 y abril de 2008. Resultados: Edad de 73.83 ± 12 años, 63.9% varones. Los pacientes con algún grado de cardiopatía estructural representaron 43%. No hubo muertes relacionadas al implante de marcapasos. Tuvieron complicaciones relacionadas con el implante 57 pacientes (7.67%); 34 casos (4.57%), requirieron de una re-intervención quirúrgica. Hubo complicaciones graves: un paciente presentó endocarditis infecciosa (0.13%) que motivó la extracción del dispositivo y otro paciente, luego de la punción venosa subclavia, presentó neumotórax con necesidad de drenaje pleural (0.13%). En el análisis multivariado, las variables independientes relacionadas fueron: un operador poco experimentado y la presencia de insuficiencia cardiaca previa al implante. Conclusiones: En esta serie consecutiva de pacientes con implante de marcapasos definitivo, la incidencia de complicaciones se correlacionó con 1) operador con poca experiencia y 2) la presencia de insuficiencia cardiaca previa al implante, se relacionaron con las mismas. Abstract in english The complications of permanent pacemaker implant, are found among 6%-9% of patients. Different factors are related. Objectives: We evaluated the complications related with pacemaker implants and which are the independent risk factors associated with them. Methods: Descriptive analysis, type case-con [...] trols, retrospective and prospective, including 743 consecutive patients, between January 2007 and April 2008. Results: Age: 73.83 ± 12 years, 63.9% male. 43% of the patients had some degree of structural cardiopathy. There were no deaths related to pacemaker implants. Implant procedure-related complications were observed in 57 patients (7.67%), requiring a surgical intervention in 34 patients (4.57%). The most serious complications included one device-related infective endocarditis (0.13%), the entire device system was extracted, and one pneumothorax following subclavian vein puncture with insertion of a chest tube. In the multivariate analysis, low level of operator experience and preimplant heart failure were independent predictors for complications. Conclusions: In this consecutive series of patients with permanent pacemaker implant, there was a low rate of complications, similar to the reported international series. A low level of operator experience and preimplant heart failure were related.

Francisco J., Femenía; Mauricio, Arce; Fernando, Peñafort; Martín, Arrieta; Daniel, Gutiérrez.

2010-06-01

225

Efficiency of grain-density autoradiographs with 125I for the light microscope  

International Nuclear Information System (INIS)

Efficiencies of grain-density autoradiographs with 125I for the light microscope were determined using Ilford L4 emulsion and Microdol X development. Calibrated layers of 125I-bovine serum albumin and polymer sections of autoradiographic [125I] micro-scales were used as reference sources. Efficiency was determined as a function of the radiation dose, source thickness and thickness of the absorber foils (e.g. non-radioactive material between the source and the emulsion), respectively. By describing the dependencies of these factors quantitatively this study provides a means for planning autoradiographic experiments. (author)

226

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

227

In vivo study about specific captation of 125 I-insulin by rat brain structures  

International Nuclear Information System (INIS)

The specific captation of 125 I-insulin was evaluated by brain structures, as olfactory bulbous, hypothalamus and cerebellum in rats, from in vivo experiences that including two different aspects: captation measure of 125 I-insulin after the intravenous injection of the labelled hormone, in fed rats and in rats with 48 h of fast or convulsion, procedure by the pentylene tetrazole; captation measure of 125 I-insulin after intra-cerebral-ventricular injection of the labelled hormone in fed rats. (C.G.C.)

228

m-[125I]iodoaniline: a useful reagent for radiolabeling biotin  

International Nuclear Information System (INIS)

Biotinyl-m-[125I]iodoanilide (BIA) was synthesized by coupling biotin to m-[125I]iodoaniline via a mixed anhydride reaction. m-[125I]Iodoaniline was produced from the tin precursor, which was prepared using a palladium catalyzed reaction of hexabutylditin with m-bromoaniline. The radioiodinated BIA derivative is characterized by a stable amide and/or intact ureido group on the biotin molecule, it may thus be a useful carrier for targeting radionuclides to avidin-conjugated antibodies previously localized on tumors. (author)

229

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

230

Effect of 1.5 tesla nuclear magnetic resonance imaging scanner on implanted permanent pacemakers.  

Science.gov (United States)

Patients with a permanent pacemaker are currently restricted from diagnostic nuclear magnetic resonance (NMR) imaging because of potential adverse effects on the pacemaker by the magnet. Previous work has shown that NMR imaging will result in asynchronous pacing of the pulse generator within a given distance of the magnet. The radiofrequency signal generated by the system may also result in rapid cardiac pacing, which may have deleterious effects. This study utilized a 1.5 tesla unit in an in vivo laboratory animal to evaluate the unit's effects on eight different pulse generators from two manufacturers. All pacemakers functioned in an asynchronous mode when placed within a certain distance of the magnet. In addition, transient reed switch inhibition was observed. Seven of the eight pulse generators paced rapidly when exposed to the radiofrequency signal and there was a dramatic decrease in arterial blood pressure. Whether effective rapid cardiac pacing would occur could not be predicted before exposure to the magnetic resonance unit. Nuclear magnetic resonance imaging with high magnetic fields in patients with a pacemaker should continue to be avoided until the mechanism of the rapid cardiac pacing can be further delineated and either predicted or prevented. PMID:3655146

Hayes, D L; Holmes, D R; Gray, J E

1987-10-01

231

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

232

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 administered just a little later (?3 or 4 days) after the start of LDR brachytherapy, when perfusion should be elevated

233

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

234

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)

235

Specific 125I labeling of D1 (herbicide-binding protein)  

International Nuclear Information System (INIS)

When 125I- was given as an artificial electron donor to non-O2-evolving thylakoids of spinach, a 29 kDa polypeptide was specifically tagged by 125I due to its photooxidation by PS II. The authors examined precisely the 125I-labeling pattern in comparison with azido[14C]atrazine photoaffinity labeling of D1 and immunoblotting with anti-D1 and anti-D2, and found that D1 (herbicide-binding protein) of PS II reaction center complex is specifically tagged by 125I in three different species of higher plants (spinach, pea and wheat) and a thermophilic cyanobacterium (Synechococcus vulcanus). It was suggested that D1 bears the photooxidation site or has a domain very close to the photooxidation site on the donor side of PS II, in addition to the well established binding site for QB and herbicides on the acceptor side of PS II. (Auth.)

236

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

237

Relationship between alveolar bone measured by 125I absorptiometry with analysis of standardized radiographs: 1. Magiscan  

International Nuclear Information System (INIS)

Previous studies have shown that 125I absorptiometry gives an accurate and sensitive measure of alveolar bone mass. The purpose of this study was to determine the relationship between alveolar bone mass determined by 125I absorptiometry and bone density obtained by analysis of standardized intraoral radiographs by the Magiscan System. A defect of increasing size was made at one site of the alveolar bone in a human skull. The amount of bone remaining at each step was calculated using 125I absorptiometry. Standardized radiographs were also taken at each step and the relative density in the area of the defect was determined by the Magiscan System. The Magiscan's System Computer Memory permits analysis of identical areas on a longitudinal series of films of the same alveolar bone location. The results indicate that in estimating amounts of alveolar bone the Magiscan analysis of standardized intraoral radiography is similar in sensitivity and accuracy to 125I absorptiometry

238

Microchemical synthesis of the serotonin receptor ligand, 125I-LSD  

International Nuclear Information System (INIS)

The synthesis and properties of 2-[125I]-lysergic acid diethylamide, the first 125I-labeled serotonin receptor ligand, are described. A novel microsynthesis apparatus was developed for this synthesis. The apparatus employs a micromanipulator and glass micro tools to handle microliter to nanoliter volumes on a microscope stage. This apparatus should be generally useful for the synthesis of radioligands and other compounds when limited amounts of material must be handled in small volumes

239

Comparative biological efficacy of sup(125)I and sup(131)I  

International Nuclear Information System (INIS)

The data on the study of comparati.ve biological efficiency of 125I and 131I according to the changes in the biochemical indices of blood serum and liver in rats are presented. It is shown that the biological effects induced by 125I and 131I are comparable and are determined by the level of tissue dose accumulated by the thyroid and by the period of radionuclide effect on the thyroid

240

Unlabelled iododeoxyuridine increases the rate of uptake of [125I]iododeoxyuridine in human xenografted glioblastomas  

International Nuclear Information System (INIS)

5-Iodo-2'-deoxyuridine (IdUrd), a thymidine (TdR) analogue, can be radiolabelled with iodine-125, an Auger radiation emitter, to provoke double-strand breaks once incorporated into DNA of cancer cells. We have previously shown that co-incubation of [125I]IdUrd with unlabelled IdUrd provided an additive cytotoxicity in two human glioblastoma cell lines. This observation was unexpectedly correlated with an increase in the rate of DNA incorporation of [125I]IdUrd. Here, we further evaluated the effects of unlabelled IdUrd on the uptake of [125I]IdUrd in vitro and in vivo in mice xenografted with three human glioblastoma lines. The results showed that, in these three glioblastoma lines, unlabelled IdUrd increased the rate of uptake of [125I]IdUrd in vitro by 2- to 4.4-fold and in vivo by 1.5- to 2.8-fold. The rate of uptake of [125I]IdUrd in normal rapidly dividing tissues was also increased by 1.3- to 2.8-fold. TdR completely blocked [125I]IdUrd uptake in tumours and tissues. Analogues of IdUrd, such as deoxyuridine and 5-iodo-1,3-dimethyuracil, did not reproduce the effect of IdUrd on the uptake of [125I]IdUrd, suggesting that it is not related to protection against [125I]IdUrd degradation. It is concluded that combined administration of unlabelled IdUrd may improve the use of radiolabelled IdUrd for cancer diagnosis or therapy. (orig.)

 
 
 
 
241

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)

242

The measurement of 125I-incorporation in radioimmunological laboratory personnel  

International Nuclear Information System (INIS)

The 125I accumulation in the thyroid of medical personnel working in RIA-laboratory and scintigraphic laboratory were measured and compared with control persons. No significant difference could be found between the two groups, whereas both of them differed significantly from the control group. However, the radiation exposition due to 125I accumulation did not exceed the value of 0.3 mGy per year. (L.E.)

243

Selective binding of 2-[125I]iodo-nisoxetine to norepinephrine transporters in the brain  

International Nuclear Information System (INIS)

A radioiodinated ligand, (R)-N-methyl-(2-[125I]iodo-phenoxy)-3-phenylpropylamine, [125I]2-INXT, targeting norepinephrine transporters (NET), was successfully prepared. A no-carrier-added product, [125I]2-INXT, displayed a saturable binding with a high affinity (Kd=0.06 nM) in the homogenates prepared from rat cortical tissues as well as from LLC-PK1 cells expressing NET. A relatively low number of binding sties (Bmax=55 fmol/mg protein) measured with [125I]2-INXT in rat cortical homogenates is consistent with the value reported for a known NET ligand, [3H]nisoxetine. Competition studies with various compounds on [125I]2-INXT binding clearly confirmed the pharmacological specificity and selectivity for NET binding sites. Following a tail-vein injection of [125I]2-INXT in rats, a good initial brain uptake was observed (0.56% dose at 2 min) followed by a slow washout from the brain (0.2% remained at 3 hours post-injection). The hypothalamus (a NET-rich region) to striatum (a region devoid of NET) ratio was 1.5 at 3 hours post-i.v. injection. Pretreatment of rats with nisoxetine significantly inhibited the uptake of [125I]2-INXT (70-100% inhibition) in locus coeruleus, hypothalamus and raphe nuclei, regions known to have a high density of NET; whereas escitalopram, a serotonin transporter ligand, did not show a similar effect. Ex vivo autoradiography ofsimilar effect. Ex vivo autoradiography of rat brain sections of [125I]2-INXT (at 3 hours after an i.v. injection) displayed an excellent regional brain localization pattern corroborated to the specific NET distribution in the brain. The specific brain localization was significantly reduced by a dose of nisoxetine pretreatment. Taken together, the data suggest that [123I]2-INXT may be useful for mapping NET binding sites in the brain

244

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

International Nuclear Information System (INIS)

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

245

Evidence for multiple pathways of 125I-insulin internalization in isolated rat hepatocytes  

International Nuclear Information System (INIS)

Insulin internalization has been characterized frequently as occurring by the coated pit pathway of receptor-mediated endocytosis. The present study in rat hepatocytes demonstrates that insulin internalization is, in part, receptor-mediated, but also occurs by nonreceptor-mediated or fluid-phase endocytosis. Endocytosis was probed with four perturbations: depletion of metabolic energy with anoxia, inhibition of endocytosis with phenylarsine oxide, disruption of coated pits with hyperosmolar sucrose, and inhibition of receptor recycling or ligand-receptor dissociation with monensin. Internalization of 125I-epidermal growth factor and 125I-asialofetuin was compared to 125I-insulin internalization. Pretreatment of cells with anoxia or hyperosmolarity inhibited 125I-insulin internalization by 40%; pretreatment with phenylarsine oxide resulted in inhibition by 54%. Monensin has no effect on uptake or degradation of a high insulin concentration, but inhibited degradation of a low insulin concentration resulting in intracellular accumulation of insulin. In contract, all four perturbations inhibited 125I-asialofetuin internalization by greater than 90%. Phenylarsine oxide almost completely abolished 125I-epidermal growth factor uptake; the other perturbations caused partial inhibition. Competition studies demonstrated that insulin internalization was receptor-mediated over a wide concentration range

246

Dose rate distribution on cultured cell exposed to 125I seed in vitro irradiation  

International Nuclear Information System (INIS)

Objective: To study the dose rate distribution on cultured cell plane and establish a reference dose rate table of in vitro cell line 125I seed irradiator. Methods: Thermoluminescence dosimetry (TLD) was used to measure the irradiation dose rate of a single 6711 model 125I seed with apparent activity of 10.323 MBq in water at point P. Meanwhile, the theoretic value of the irradiation dose rate at point P was calculated with theoretic formula. The difference between the calculated and observed values within 10% was set as standard to analyze the accuracy of the measurement. The irradiation dose rate ora single 6711 model 125I seed was measured in 1 mm- thick polystyrene + water medium at point P. The value was applied to differential m non-differential proof along with the value from water medium to study the effect of 1 mm thick polystyrene on distribution of irradiation dose in water. Finally, by simulating the 125I seed plane irradiator with nine 125I seeds, the distribution table of irradiation dose rate on the cultured cell plane was calculated with theoretical formula. Results: The observed value (n 10) of irradiation dose rate with one 125I seed in water at point P was(0.359 ± 0.023) eGy/h and the calculated value was 0.347 cGy/h, the difference was within 10%. The observed value (n=10) of irradiation dose of one 125I seed in 1 mm-thick polystyrene + water medium at point P was (0.350 ene + water medium at point P was (0.350±0.027) cGy/h, which showed no statistical difference from the observed value in water under differential and non-differential proof. The reference table on dose rate distribution for cells exposed to 125I seed irradiation in vitro was developed. Conclusions: 1 mm-thick polystyrene gives no significant effect on irradiation dose rate distribution flora 125I seeds in water. A reference table on the dose rate distribution for cells exposed to 125I seed irradiation in vitro has been developed, which can be used to determine an optimal irradiating strategy for future work. (authors)

247

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

International Nuclear Information System (INIS)

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), 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

248

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

249

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 básico 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 hospitalesObjective: 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 from 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

2011-03-01

250

¿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

251

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

International Nuclear Information System (INIS)

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)

252

Physical and radiobiological bases of the use of 125I in the management of thyrotoxicosis  

International Nuclear Information System (INIS)

Increasing interest is recently shown in the use of 125I as an alternative isotope to 131I for the management of thyrotoxicosis 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. A review of the dosimetric, radiobiological and clinical aspects of the use of 125I are presented here. For the same activity though 125I gives smaller mean gland dose than 131I, the dose computations at microscopic level have revealed that there is a preferential irradiation of the apical membrane compared to the nucleus of the follicular cell. The ratio of the dose to the apical membrane an that to the nucleus increases with the decrease of the percentage colloid mass of the gland. Radiobiological significance of this non-uniform dose distribution across a follicular cell, with 125I, is brought out using rat thyroid as the biological system. For the same mean gland dose the follicular cell survival is larger with 125I than with 131I. 24 h radioiodine uptake is reduced in case of 131I treatment whereas it is not affected with 125I. Pilot clinical trials using 125I for the management of thyrotoxicosis are underway in some centres. Preliminary results form centres using doses 3-4 times that of the conventional 131I dose are not very different from those with conventional 131I therapy. Centres that used doses same as or less than the conventional 131I doses, reported smaller incidence of hypothyroidism. (orig.)

253

In vitro characterization of the influx of 3-[125I]iodo-L-?-methyltyrosine and 2-[125I]iodo-L-tyrosine into U266 human myeloma cells: Evidence for System T transport  

International Nuclear Information System (INIS)

The aim of this study was to investigate the cellular uptake mechanisms responsible for the accumulation of 3-[125I]iodo-L-?-methyltyrosine (125I-3-IMT) and 2-[125I]iodo-L-tyrosine (125I-2-IT), two radiotracers for metabolic tumor imaging, using single-photon emission tomography, into U266 human myeloma cancer cells. Time course and concentration dependency of 125I-3-IMT uptake was assessed. Kinetic parameters were calculated using an Eadie Hofstee plot. A set of competitive inhibitors of the main amino acid transport systems was used for the discrimination of the transporters responsible for the uptake of 125I-3-IMT and 125I-2-IT. Protein incorporation of both tracers was determined using acid precipitation. The measured maximum velocity for 125I-3-IMT transport was 4.199 nmol per mg protein 20 s-1, and the Michaelis constant was 107.9 ?M. Addition of 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH), a competitive inhibitor of System L, reduced the influx by 39.0±3.3% for 125I-3-IMT and 66.3±0.9% for 125I-2-IT. The BCH-insensitive influx was further reduced by Tryptophan (Trp) by 43.8±3.5% for 125I-3-IMT and 15.3±1.3% for 125I-2-IT. This suggests involvement of System T transport. We measured 125I-3-IMT and 125I-2-IT into U266 human myeloma cells is mediated by both System L and System T amino acid transporters. The kinetic parameters suggest that elevated plasma levels of aromatic amino acids will reduce 123I-3-IMT uptake in myeloma patients. Both tracers do not enter protein synthesis significantly

254

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

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

Asakura Hirotaka

2010-09-01

255

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)

256

Labelling of antisense oligonucleotide with 125I and the experimental research of identification of the lymphoma cell by using 125I-FR-ASON  

International Nuclear Information System (INIS)

Objective: To establish a new method of labeling oligonucleotide with radioisotope of iodine and to investigate the possibility of using 125I-FR-ASON as imaging agent or therapeutic antisense radiopharmaceutical in lymphoma. Methods: A 18 mer oligonucleotide sequence was synthesized and grafted in 5' with a tyramine group. Radioiodination of the tyramine conjugated oligonucleotide with 125I was performed using the Chloramine T method. The Namalwa and HL-60 cell lines were transduced with DMRIE-C mediated 125I-ASON, then the transduction efficiency was calculated, authors also compared it with the transduction efficiency without DMRIE-C reagent. After incubation with serum, the tyramine-ASON was analysed by electrophoresis in 20% polyacrylamide gel. Results: The radiolabeling efficiency, radiochemical purity and specific activity were 80.7%, 98.7% and 100 kBq/?g, respectively. The transduction efficiency in Namalwa cell line reached (26.8 ±1.54)% that was as 18 times greater as that in transduction without mediation. The transduction efficiency in HL-60 cell line was only (13.6 ± 2.54)%, that was far lower than in Namalwa cell line. The gel electrophoresis showed that there wasn't any additional band at 2, 6 and 24 h post-incubation. Conclusions: The radioiodination method by conjugating the oligonucleotide with tyramine was very successful. The 125I-FR-ASON showed high specificity in Namalwa cell line and it could be used as an antisense imaging agent or antisense radiopharmaceutical in therapeutic research on lymphoma

257

[125I] radioiodinated metaraminol: A new platelet-specific labeling agent  

International Nuclear Information System (INIS)

In our search for a platelet-specific labeling agent, metaraminol (MA), a low-toxic pharmaceutical for the treatment of hypotension and cardiogenic shock, attracted our attention. Its active incorporation and accumulation by platelets have been recognized. At first, the preparation of 125I radioiodinated metaraminol (125I-MA) was carried out using the chloramine-T method. Then, upon the harvest of platelets as platelet-rich plasma (PRP), their labeling with this new radiopharmaceutical was easily performed by incubation for 10 min at 370C. The cell-labeling efficiency was dependent on cell density, reaching 63.0%+-3.1% at 2.4x109 cells/ml. The specific incorporation of 125I-MA by an active transport system similar to that of 5-hydroxytryptamine (5-HT) as well as by passive diffusion was demonstrated. In vitro studies, the unaltered state of 125I-MA-labeled platelets with their cellular functions fully retained was estimated. In vivo studies carried out in rabbits with induced thrombi in the femoral artery showed a rather rapid disappearance of the radioactivity from circulating blood, reaching a high thrombus-to-blood activity ratio of 19.8+-4.3 within 30 min of the administration of 125I-MA-labeled autologous platelets. Thus, with the potential availability of 123I, 123I-MA-labeled platelets appear to be a promising agent for thrombus imaging using single-emission computed tomography (CT) studies. (orig.)

258

Can [125I]-iodocyanopindolol label ß3-adrenoceptors in rat urinary bladder?  

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Full Text Available ?3-Adrenoceptors have been demonstrated to mediate urinary bladder smooth muscle relaxation but proof of their expression at the protein level has been missing because of lack of suitable antibodies or radioligands. As among various available radioligands [125I]-iodocyanopindolol ([125I]-ICYP exhibited the smallest problems in labelling cloned human ?3-adrenoceptors in previous studies, we have explored its suitability to label ?3-adrenoceptors in rat urinary bladder in saturation and competition radioligand binding experiments. Rat lung was used as an internal control and exhibited all characteristics expected from this tissue with regard to ?1/?2-adrenoceptor labelling. Saturation and competition binding studies with [125I]-ICYP in rat bladder yielded saturable binding sites with an affinity compatible with ?3-adrenoceptors. In competition experiments various agonists and antagonists largely exhibited a profile compatible with a population consisting largely of ?3-adrenoceptors. However, the binding competition properties of ICI 118,551 and SR 59,230A were not easily explained by the idea of labelling a homogeneous ?3-adrenoceptor population but interpretation of the data was limited by a high degree of non-specific binding in [125I]-ICYP concentrations required to label the receptors. We conclude that [125I]-ICYP can be used to label tissue ?3-adrenoceptors but results obtained with this ligand have to be interpreted with caution.

MartinChristianMichel

2010-10-01

259

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

260

Monte Carlo dosimetry for 125I and 60Co in eye plaque therapy  

International Nuclear Information System (INIS)

Monte Carlo calculations of radiation dosimetry using morse code are performed for 125I and 60Co point sources in a cylindrical head phantom that simulates the geometry of eye plaque therapy for choroidal melanoma. We obtain the dose variation in the eye at submillimeter intervals over distances as close as 1 mm and up to 2.5 cm from the source. The calculations for 125I are performed for the phantom media of water, protein, and a homogenized protein--water mixture simulating the composition of the eye. Relative dose functions for 125I for these phantom media are fitted to second-degree polynomials. Agreement is found with published results. The relative dose function for 60Co at eye position in the water head phantom is fitted to a third-degree polynomial and compared with that for 60Co at the center of a large water sphere. A boundary effect due to the head phantom--air interface on the dose distribution for 60Co is demonstrated. The dose falloff with distance is faster for the eye geometry compared with the bulk geometry. We also show that the relative dose distributions within the tumor are comparable for 125I and 60Co by comparing their relative dose functions. This result is consistent with the success of clinical trials of large melanoma treatments with 125I plaques

 
 
 
 
261

Studies with encapsulated 125I sources. I. Apparatus and dosimetry for determination of relative biological effectiveness  

International Nuclear Information System (INIS)

Apparatus and dosimetry techniques have been developed which make possible studies of the biological effects of radiation from encapsulated 125I sources at clinically relevant dose rates using mammalian cells attached to culture dishes. The variation of dose rate from 125I photons as a function of distance from the interface between different materials was investigated. A polystyrene substrate changes the mean dose rate in attached cells by about 21%, depending on cell thickness. To reduce dosimetry uncertainty caused by this effect, special petri dishes were made from polyvinylidene fluoride, which changes the mean dose in attached cells by only 10%. Chinese hamster ovary cells attached to these dishes were cultured in incubators which contained 125I and 137Cs sources, allowing the effects of various dose rates (.005 to 0.80 Gy/hr) of radiation from the two isotopes to be compared. The relative dose rates from these low- and high-energy photons were measured with an accuracy of +/- 7% or better using an air-equivalent ionization chamber designed to resemble one of our special petri dishes. Calculations of dose rates from 125I give values within 4% of the measured dose rates used to determine the relative biological effectiveness of 125I photons

262

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

263

/sup 125/I-spiperone: a novel ligand for D/sub 2/ dopamine receptors  

Energy Technology Data Exchange (ETDEWEB)

/sup 125/I-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 /sup 125/I-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 /sup 125/I-spiperone binding correlates well with that of /sup 3/H-spiperone binding, providing good evidence that /sup 125/I-spiperone labels D/sub 2/ dopamine receptors in striatal membranes. /sup 125/I-Spiperone, with its high specific activity (2200 Ci/mmol) may prove to be a useful ligand in studies examining D/sub 2/ dopamine receptors in soluble preparations and by autoradiography. Furthermore iodinated spiperone may be useful in radioreceptor assays of neuroleptic drug levels and, in a /sup 123/I-labeled form for imaging of dopamine receptors, in vivo, using single photon tomography. 18 references, 4 figures, 1 table.

Gundlach, A.L.; Largent, B.L.; Synder, S.H.

1984-11-05

264

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

265

Radioimmunoassay for etorphine in horses with a 125I analog of etorphine.  

Science.gov (United States)

To improve the sensitivity and specificity of screening for etorphine in horses, an 125I-labeled etorphine analog was synthesized and an antibody to etorphine was raised in rabbits. A radioimmunoassay (RIA) for etorphine was developed, using these reagents. Bound and free 125I-labeled etorphine was separated by a double-antibody method that reduced interference from materials associated with equine urine. The 125I-labeled etorphine binding was rarely greater than 250 pg of background etorphine equivalents/ml in raw urine and was 100 pg/ml in hydrolyzed urine. The 125I-RIA was capable of detecting etorphine equivalents in urine above these background values. Etorphine equivalents were detected in equine urine samples for about 7 days after 4 mares were dosed with 0.22 microgram of etorphine/kg of body weight, IV. The stability of etorphine in urine from these mares was evaluated. Urine from these dosed mares was held in constant -20 C storage, and aliquots were repeatedly frozen and thawed. When analyzed for etorphine equivalents using an 125I-RIA, etorphine and its metabolites in urine samples were stable for less than or equal to 38 days if continuously frozen and also were resistant to repeated freezing and thawing. PMID:3395007

Tai, C L; Wang, C; Weckman, T J; Popot, M A; Woods, W E; Yang, J M; Blake, J; Tai, H H; Tobin, T

1988-05-01

266

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

Energy Technology Data Exchange (ETDEWEB)

An iodinated ({sup 125}I/{sup 127}I) ethidium derivative (3,8-diamino-5-[6'-(p-iodobenzoylamino)-4'-azahexyl]-6 -phenylphenanthridinium chloride hydrochloride) was synthesized and characterized. The labeling yield of the {sup 125}I-labeled derivative was 75% for carrier-free {sup 125}I, 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, {sup 125}I/{sup 127}I-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 {sup 125}I-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 tumors in humans.

Ho Nanhui; Tumeh, Paul C.; Kassis, Amin I. E-mail: amin_kassis@hms.harvard.edu

2001-11-01

267

Radioimmunoassay for etorphine in horses with a 125I analog of etorphine  

International Nuclear Information System (INIS)

To improve the sensitivity and specificity of screening for etorphine in horses, an 125I-labeled etorphine analog was synthesized and an antibody to etorphine was raised in rabbits. A radioimmunoassay (RIA) for etorphine was developed, using these reagents. Bound and free 125I-labeled etorphine was separated by a double-antibody method that reduced interference from materials associated with equine urine. The 125I-labeled etorphine binding was rarely greater than 250 pg of background etorphine equivalents/ml in raw urine and was 100 pg/ml in hydrolyzed urine. The 125I-RIA was capable of detecting etorphine equivalents in urine above these background values. Etorphine equivalents were detected in equine urine samples for about 7 days after 4 mares were dosed with 0.22 microgram of etorphine/kg of body weight, IV. The stability of etorphine in urine from these mares was evaluated. Urine from these dosed mares was held in constant -20 C storage, and aliquots were repeatedly frozen and thawed. When analyzed for etorphine equivalents using an 125I-RIA, etorphine and its metabolites in urine samples were stable for less than or equal to 38 days if continuously frozen and also were resistant to repeated freezing and thawing

268

Beta-irradiation (106RU 106RH) versus gamma-irradiation (125I): a comparative study on the normal rabbit eye  

International Nuclear Information System (INIS)

Objective: To compare the clinical and histological effects of brachytherapy using 125I and 106Ru 106Rh on normal rabbit eyes with doses similar to those recommended in man for choroidal melanoma treatment. Methods: Fourteen pigmented rabbit eyes were treated with a 12 mm applicator either loaded with 125I, either 106Ru 106Rh, or inactive (control). In the 125I group, the eyes received 100 Gy at 5 mm (COMS recommendations). In the 106Ru 106Rh group, the eyes received 100 Gy a 3,5 mm (apex of a theoretical melanoma with a 3 mm height). The doses at different points of the sclera, retina, optic disc, lens, were calculated using two softwares. The radiation effects were evaluated by clinical and histological examination after 4 days, 4 weeks, 3, 6, 9 months and one year. Results: Although the mean total dose at the external sclera and the irradiated volume were always more important in the 125I group, the observed damaging effects were much more important in the 106Ru106 Rh group. At the plaque implantation site, in the 125I group, the fundus lesions were invisible until the sixth month and then appeared as a very discrete pigmentation without any gross vascular modification. In the 106Ru 106Rh group, there was a retinal necrosis after a few days, followed by an atrophic chorioretinal scar. The retinal and choroidal vessels were destroyed. A cataract was observed in one eye of each group after six months. One explanation of the differences in the biological responses observed for comparable macroscopic doses could be the different distributions of the ionizations at a microscopic scale. Conclusions: The choice of the best isotope able to deliver a sterilizing dose to a choridal melanoma while reducing the radiation damages to the normal ocular structure is still in discussion. In our study on normal ocular tissues, with a follow-up limited to one year. 125I demonstrated to be less damaging than 106Ru 106Rh

269

The experimental study of 125I seeds interstitial brachytherapy combined with external beam radiotherapy for lewis lung cancer in C57BL/6 mice  

International Nuclear Information System (INIS)

Objective: The purpose of this study was to investigate the efficacy of 125I seeds interstitial brachytherapy combined with external beam radiotherapy for lung neoplasm. Methods: Each set of six C57BL/6 mice bearing Lewis tumor was stratified into four groups on day 1:vehicle control, 125I seeds interstitial brachytherapy alone, external beam radiotherapy (15 Gy) alone, and combination of 125I seeds interstitial brachytherapy with external beam radiotherapy (8 Gy). After treatment.the volulne of the tumors was measured every 3 days. The animals were executed, the weight of tumors was measured.tumor control rate was calculated and pathological examination was performed on day 15. The intratumoral micro-vaseular density (MVD) in each group was evaluated by inmmnohistochemical methads. Tumor volume.weight and MVD were compared by one-way ANOVA, student. newlnan-keuls (SNK) -q analysis. Results: Comparing with control group, the other three groups had significant inhibiting effect on the growth of lewis tumor (q=11.06, 17.13, 16.31, all P125I seeds interstitial brachytherapy group (28.6%). while the difference of tumor weisht was not significant between the former two groups (q=0.50. P>0.05). Immunohistochemistry analysis showed that the MVD value in the four groups wag (23.33 ± 4.84). ( in the four groups wag (23.33 ± 4.84). (17.50 ± 3.67), (11.83 ± 2.14) and (12.67 ± 3.39) / (high power field x 200) regpectively. The MVD value of 125I seeds interstitial brachytherapy alone group was much lower than that of control group, and higher than combination group (q=3.92 and 3.25, both P0.05). Conclusions: Radiotherapy can. significantly reduce the MVD values of tumor and inhibit tumor growth through the mechanisms of antiangiogenesis. The combined treatment of lung tumors with implanted 125I seeds and external beam irradiation can decrease the total dose of the external beam irradiation and, hence, offer the possibility of considerable dose sparing of normal tissues without compromising local tumor control rates. (authors)

270

Experimental study on the killing effect of 125I seeds to Hela cells  

International Nuclear Information System (INIS)

Objective: To investigate the rules of apoptosis and proliferation of Hela cells in vitro irradiated with 125I seeds and the killing effect to tumor cells. Methods: The proliferation reaction and morphological change of Hela cells with low energy ? ray 125I irradiation in different dose and duration were observed. Results: The apoptosis segments of Hela cells irradiated with 125I appeared was on stage II b. However, significant increase in the cell apoptosis ratio related to the dose accumulation and apoptosis reached peak level at a total dose of 5 Gy. meanwhile, the results of the cell clones generally correlated negatively with apoptosis and demonstrated a significant reduction. A reverve dose rate effect was also found. Conclusion: The therapeutic effect of 131I seeds irradiation probably may be the inhibition of cell proliferation in early stage, and apoptosis of large amount of tumor cells in later stage. (authors)

271

Preparation and Evaluation of (125I) Daunorubicin as a Potential Agent for Tumor Detection and radiotherapy  

International Nuclear Information System (INIS)

In this study, the optimization of daunorubicin labeling with iodine-125 and its biological evaluation were described. Daunorubicin was labeled via direct electrophilic substitution using chloramine-T as oxidizing agent. The optimum amounts of reactants were: 40?g daunorubicin, 30?g Chloramine-T and ? 19 KBq carrier free Na125I. The labeled daunorubicin was stable for more than 24 hours. Results of the in-vivo evaluation revealed that the tracer, [125I] daunorubicin, tends to localize in tissues with high proliferation rate with preferential accumulation in cancerous tissues. Imaging should be carried at 3 hours post injection. The in-vitro cell growth inhibition assay showed that the effect of [125I] Daunorubicin was stronger than the effect of cold daunorubicin which strongly suggested that its cytotoxicity was mainly due to radiotoxicity rather than chemotherapeutic activity.

272

Preparation of 125I-protein A usable for up to 10 months in immunoassays  

International Nuclear Information System (INIS)

Chloramine-T iodination of protein A from Staphylococcus aureus and gel electrophoretic purification of the iodination mixture results in a stable tracer of high specific and functional activity. Following repeated gel electrophoresis of the tracer only a single component was observed. The specific activity of the 125I-protein A was between 30 and 55 ?Ci/?g. The binding of 125I-protein A to rabbit immunoglobulin exceeded 90% and the tracer competed effectively with unlabelled protein A in binding to cells incubated with sera containing surface antibodies. Storage of the tracer for up to 46 weeks resulted in a moderate decrease in maximal binding to immunoglobulin (from 91% to 64%), in TCA precipitable radioactivity (from 97% to 80%) and an approx. 30% decrease in the ability to detect cell bound immunoglobulin. It is concluded that gel electrophoretic purification of 125I-protein A produces a tracer with a very long shelf life. (Auth.)

273

Binding of 125I-hCG to rainbow trout (Salmo gairdneri) testis in vitro  

International Nuclear Information System (INIS)

Homogenates of maturing rainbow trout testes show specific binding sites for 125I-labeled hCG (. 125I-labeled hCG). The binding is competitively inhibited by unlabeled hCG and by a hypophyseal extract of rainbow trout. It could be demonstrated that the tissue 125I-hCG binding specificity is restricted to the gonadal preparation. The trout testis was characterized by determining affinity and capacity from Scatchard plot analysis giving a high constant of dissociation Kd 3.65 x 10(-10)/M and a low binding capacity of 0.88 x 10(-15) M/mg tissue. The test system is markedly dependent on temperature, incubation-time, and pH. The maximum binding was found at 37 degrees during 2 hr of incubation in a buffer of pH 7.5

274

A novel 125I-labeled phenylpiperidine radiotracer for ?1 receptor imaging  

International Nuclear Information System (INIS)

Objective: Development of radioligands with high affinity and selectivity for ?1 receptors provides sensitive molecular probes to the early diagnosis of central nervous system (CNS) diseases. Method: [125I]1-(4-iodobenzyl)-4-cyano-4-phenylpiperidine ([125I]Pp-CN-I) was designed and synthesized via an iododestannylation reaction. Its biological evaluations in vitro and in vivo were carried out. Results: The Ki values of Pp-CN-I for ?1 and ?2 receptors were 2.14±0.44nM and 1.71±0.65?M, respectively. The radio-chemical purity (RCP) of [125I]Pp-CN-I was higher than 99.9 % by HPLC analysis after purification. The biodistribution results in normal mice showed that [125I] Pp-CN-I exhibited high initial brain uptake and quick washout from blood. But the radioactivity accumulation was also washed out quickly from the brain. Administration of haloperidol 5 min prior to injection of [125I]Pp-CN-I significantly reduced the concentration of radioactivity in organs known to contain ?1 receptors. SPECT imaging in SD rat also demonstrated high initial brain uptake of the radiotracer and quick washout from the brain. The LC-MS results of Pp-CN-I and its metabolites in rat brain indicated that oxidation is the major metabolic pathway. Conclusion: [125I]Pp-CN-I possesses high affinity and selectivity to ?1 receptors and binds to ?1 receptors specifically in vivo. The fast metabolic degradation in brain limits its further applications in clinic. (authors)

275

Binding and degradation of 125I-insulin by renal glomeruli and tubules isolated from rats  

International Nuclear Information System (INIS)

Isolated rat renal glomeruli and tubules were shown to exhibit specific binding of 125I-insulin and enzymatic degradation of the hormone. Binding to both renal fractions reached a plateau by 1 h at 220C and increased linearly with increasing protein concentrations. Binding was inhibited in both preparations by insulin and its analogues in the order of relative potency: insulin > despentapeptide insulin > proinsulin, but insulin was ten times more potent in inhibiting 125I-insulin binding to glomeruli than that to tubules, indicating a different affinity of receptors for the hormone in the two renal fractions (about 17 versus 210 ?g unlabelled insulin/1 inhibiting 50% of the 125I-insulin binding to glomeruli and tubules, respectively). Bound 125I-insulin dissociated at a faster rate from tubules than from glomeruli; this release was accelreated by unlabelled insulin in both renal fractions, but to a greater extent in glomeruli than in tubules. Two-thirds of the total bound material released from glomeruli was found to be intact insulin as measured by trichloroacetic acid precipitation, whereas only one-third of the material released from tubules was intact. No direct relationship beteen binding and degradation of 125I-insulin in these renal fractions could be demonstrated, however, because of the release of proteolytic enzymes into the incubation medium resulting in almost all degradation being extracellular. Although differing in their affinity for 125I-insulin the high affinity glomerular insulin receptor and the lower affinity tubular insulin receptor have characteristics similar to those of insulin receptors in insulin responsive tissues. (orig.)

276

Simple detection of hepatitis C virus using 125I-2'-deoxyuridine triphosphate and gamma counter  

International Nuclear Information System (INIS)

Hepatitis C Virus (HCV) is the major cause of post transfusion and sporadic non A, non B hepatitis. Current infection of HCV can be detected by PCR method. Using PCR, it has been possible to detect HCV viremia prior to immunological sero-conversion and to detect fluctuation of viremia in antibody-positive chronic HCV patients undergoing therapy with interferon. In this study, we established the simple method to detect HCV DNA by incorporation of 125I-deoxyuridine triphosphate(dUTP) into DNA during the PCR, and counted the radioactivity of PCR product by gamma counter. 125I-2'-deoxyuridine 5'-triphosphate was prepared, and incorporated into DNA during PCR. dUTP was radiolabeled by the iododemercuration of 5-mercuri intermediate. Iododemercuration labeling was completed with 98% yield and the obtained product was incorporated into DNA without further purification. After incorporation, covalently bonded radioiodine substituent was remained stable during PCR procedure HCV positive standard and positive patient sera in immunological assay were centrifuged. HCV RNA is isolated from by GTC(Guanidine Thiocyanate) and phenol/chloroform extraction method and synthesized complementary DNA by using reverse transcriptase. The '125I-dUTP was incorporated into HCV C DNA during PCR. PCR product purified by fiber matrix column and counted by gamma counter. PCR products were electrophoresized, and autoradiography image obtained. Amplified HCV DNA by 125I-dUTP PCR obtained the band on the gel by electrophoresis and autoradiography at the same position. In patient sera, radioactivity of HCV positive sample was 8 times higher than HCV negative viremia sample. We established HCV detection method using 125I-dUTP. 125I-dUTP PCR detection of HCV is convenient and reporducible

277

Use of 2-[125I]iodomelatonin to characterize melatonin binding sites in chicken retina  

International Nuclear Information System (INIS)

2-[125I]Iodomelatonin binds with high affinity to a site possessing the pharmacological characteristics of a melatonin receptor in chicken retinal membranes. The specific binding of 2-[125I]iodomelatonin is stable, saturable, and reversible. Saturation experiments indicated that 2-[125I]iodomelatonin labeled a single class of sites with an affinity constant (Kd) of 434 +/- 56 pM and a total number of binding sites (Bmax) of 74.0 +/- 13.6 fmol/mg of protein. The affinity constant obtained from kinetic analysis was in close agreement with that obtained in saturation experiments. Competition experiments showed a monophasic reduction of 2-[125I]iodomelatonin binding with a pharmacological order of indole amine affinities characteristic of a melatonin receptor: 2-iodomelatonin greater than 6-chloromelatonin greater than or equal to melatonin greater than or equal to 6,7-dichloro-2-methylmelatonin greater than 6-hydroxymelatonin greater than or equal to 6-methoxymelatonin much greater than N-acetyltryptamine greater than N-acetyl-5-hydroxytryptamine greater than 5-methoxytryptamine greater than 5-hydroxytryptamine (inactive). The affinities of these melatonin analogs in competing for 2-[125I]iodomelatonin binding sites were correlated closely with their potencies for inhibition of the calcium-dependent release of [3H]dopamine from chicken and rabbit retinas, indicating association of the binding site with a functional response regulated by melatonin. The results indicate that 2-[125I]iodomelatonin is a selective, high-affinity radioligand for the identification and characterization of melatonin receptor sites

278

Comparison of carcinogenicity of 131I and 125I in tyroid gland of the rat  

International Nuclear Information System (INIS)

To determine whether there was a difference in the carcinogenicity of 131I and 125I for the thyroid gland, groups of 40 rats on a low-iodine diet were injected with various doses of one of the nuclides. The doses of 131I injected were 125, 50, 20, 8 and 3.2 ?Ci; doses of 125I were four times higher. The surviving rats were killed two years after injection and autopsies with complete histopathological examinations were performed. The results of survival and thyroid function studies revealed that the dose ranges in ?Ci for the two nuclides could not be directly compared and that each dose of 125I could best be compared with a 10- to 25-fold lower dose of 131I. The morphological findings in the follicular epithelium of the thyroid gland showed that the peak of induction of hyperplasia, cysts and tumours by 125I occurred in the group injected with 80 ?Ci, whereas comparable changes after 131I administration were observed in the group injected with the lowest dose (3.2 ?Ci). The peak of tumour induction by 125I in the parafollicular epithelium was found in the group injected with 32 ?Ci; the peak with 131I was probably missed, since the comparable dose for this nuclide was below the range of doses injected. The highest incidence of tumours of these parafollicular cells was 2.5 times the spontaneous incidence in control rats. However, extrapolation of these results to man seems unreliable, since the spontaneous incidence of tumours of the parafollicular cells is much higher in rats than in man. It may be concluded that 125I does not induce more tumours of the follicular cells than does 131I as has been suggested by others. (author)

279

Improved radial dose function estimation using current version MCNP Monte-Carlo simulation: Model 6711 and ISC3500 125I brachytherapy sources  

International Nuclear Information System (INIS)

Improved cross-sections in a new version of the Monte-Carlo N-particle (MCNP) code may eliminate discrepancies between radial dose functions (as defined by American Association of Physicists in Medicine Task Group 43) derived from Monte-Carlo simulations of low-energy photon-emitting brachytherapy sources and those from measurements on the same sources with thermoluminescent dosimeters. This is demonstrated for two 125I brachytherapy seed models, the Implant Sciences Model ISC3500 (I-Plant) and the Amersham Health Model 6711, by simulating their radial dose functions with two versions of MCNP, 4c2 and 5

280

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

International Nuclear Information System (INIS)

Objective: To discuss the effectiveness and therapeutic mechanism of 125I interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice. Methods: The human pancreatic cell line Sw1990 was subcutaneously injected into the right lower limb partially dorsal area next to the groin of the immunodeficient BABL /c nude mice. The tumor was removed and cut into small pieces after it was formed,then the tumor pieces were inoculated in nude mice. The tumor developed to 8-10 mm in size after six weeks. A total of 16 nude mice with the suitable tumor size were used in this study. The 16 experimental mice were randomly and equally divided into two groups. The mice in study group (n = 8) were implanted with 125I seeds, while the mice in control group (n = 8) were implanted with ghost seeds. After the implantation both the long and short diameter of the tumors as well as the mouse body weight were measured every 4 days. The tumor weight was measured when the mouse was sacrificed. The paraffin-embedded samples were sent for histopathological examination. Apoptotic cells were checked with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Expression of proliferating cell nuclear antigen (PCNA) was detected with immuno-histochemical staining. Results: The tumor grew slowly in the study group, but rapidly in the control group. The tumor weight in the study group and the control group was (2.68 ± 0.70)g and 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)

 
 
 
 
281

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)

282

Protection of 125I-glucagon from damage during the purification procedure in presence of gelatine  

International Nuclear Information System (INIS)

To produce a suitable radioiodinated glucagon for radioimmunoassay, the influence of various kinds of albumins and gelatine on the stability of iodoglucagon during the purification procedure was studied. The destruction of 125I-glucagon during the purification in presence of commercial albumin could not be prevented either after Trasylol treating, whereas gelatine did not cause any damage of 125I-glucagon which had the immunoreactivity suitable for radioiummunoassay. The sensitivity for RIA calculated as the standard deviation derived values of radioactivity corresponding to zero concentration of hormone was +-12 pg per ml. (T.I.)

283

Increased /sup 125/I-labelled concanavalin A binding to erythrocytes in diabetes mellitus  

Energy Technology Data Exchange (ETDEWEB)

Percentage binding of /sup 125/I-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 < 0.001). Insulin-dependent diabetic patients showed significantly higher concanavalin A binding than non-insulin-dependent diabetic subjects (15.0 +- 1.4 versus 11.4 +- 2.5%, p < 0.01). There was a highly significant correlation between percentage binding of /sup 125/I-labelled concanavalin A and glycosylated haemoglobin.

Okada, Y.; Arima, T.; Okazaki, S.; Nakata, K.; Nagashima, H.; Yamabuki, T.

1982-03-01

284

Selective binding of 2-[{sup 125}I]iodo-nisoxetine to norepinephrine transporters in the brain  

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A radioiodinated ligand, (R)-N-methyl-(2-[{sup 125}I]iodo-phenoxy)-3-phenylpropylamine, [{sup 125}I]2-INXT, targeting norepinephrine transporters (NET), was successfully prepared. A no-carrier-added product, [{sup 125}I]2-INXT, displayed a saturable binding with a high affinity (K{sub d}=0.06 nM) in the homogenates prepared from rat cortical tissues as well as from LLC-PK{sub 1} cells expressing NET. A relatively low number of binding sties (B{sub max}=55 fmol/mg protein) measured with [{sup 125}I]2-INXT in rat cortical homogenates is consistent with the value reported for a known NET ligand, [{sup 3}H]nisoxetine. Competition studies with various compounds on [{sup 125}I]2-INXT binding clearly confirmed the pharmacological specificity and selectivity for NET binding sites. Following a tail-vein injection of [{sup 125}I]2-INXT in rats, a good initial brain uptake was observed (0.56% dose at 2 min) followed by a slow washout from the brain (0.2% remained at 3 hours post-injection). The hypothalamus (a NET-rich region) to striatum (a region devoid of NET) ratio was 1.5 at 3 hours post-i.v. injection. Pretreatment of rats with nisoxetine significantly inhibited the uptake of [{sup 125}I]2-INXT (70-100% inhibition) in locus coeruleus, hypothalamus and raphe nuclei, regions known to have a high density of NET; whereas escitalopram, a serotonin transporter ligand, did not show a similar effect. Ex vivo autoradiography of rat brain sections of [{sup 125}I]2-INXT (at 3 hours after an i.v. injection) displayed an excellent regional brain localization pattern corroborated to the specific NET distribution in the brain. The specific brain localization was significantly reduced by a dose of nisoxetine pretreatment. Taken together, the data suggest that [{sup 123}I]2-INXT may be useful for mapping NET binding sites in the brain.

Kung, M.-P.; Choi, Seok-Rye; Hou, Catherine; Zhuang, Z.-P.; Foulon, Catherine; Kung, Hank F. E-mail: kunghf@sunmac.spect.upenn.edu

2004-07-01

285

p-[125I]iodoclonidine is a partial agonist at the alpha 2-adrenergic receptor  

International Nuclear Information System (INIS)

The binding properties of p-[125I]iodoclonidine [( 125I]PIC) to human platelet membranes and the functional characteristics of PIC are reported. [125I]PIC bound rapidly and reversibly to platelet membranes, with a first-order association rate constant (kon) at room temperature of 8.0 +/- 2.7 x 10(6) M-1 sec-1 and a dissociation rate constant (koff) of 2.0 +/- 0.8 x 10(-3) sec-1. Scatchard plots of specific [125I]PIC binding (0.1-5 nM) were linear, with a Kd of 1.2 +/- 0.1 nM. [125I]PIC bound to the same number of high affinity sites as the alpha 2-adrenergic receptor (alpha 2-AR) full agonist [3H] bromoxidine (UK14,304), which represented approximately 40% of the sites bound by the antagonist [3H]yohimbine. Guanosine 5'-(beta, gamma-imido)triphosphate greatly reduced the amount of [125I]PIC bound (greater than 80%), without changing the Kd of the residual binding. In competition experiments, the alpha 2-AR-selective ligands yohimbine, bromoxidine, oxymetazoline, clonidine, p-aminoclonidine, (-)-epinephrine, and idazoxan all had Ki values in the low nanomolar range, whereas prazosin, propranolol, and serotonin yielded Ki values in the micromolar range. Epinephrine competition for [125I]PIC binding was stereoselective. Competition for [3H]bromoxidine binding by PIC gave a Ki of 1.0 nM (nH = 1.0), whereas competition for [3H]yohimbine could be resolved into high and low affinity components, with Ki values of 3.7 and 84 nM, respectively. PIC had minimal agonist activity in inhibiting adenylate cyclase in platelet membranes, but it potentiated platelet aggregation induced by ADP with an EC50 of 1.5 microM. PIC also inhibited epinephrine-induced aggregation, with an IC50 of 5.1 microM. Thus, PIC behaves as a partial agonist in a human platelet aggregation assay. [125I]PIC binds to the alpha 2B-AR in NG-10815 cell membranes with a Kd of 0.5 +/- 0.1 nM

286

An instrument for measurement of 125I with automatic efficiency correction  

International Nuclear Information System (INIS)

Counting efficiencies for 125I are often uncertain because of self-absorption of the low-energy radiation. A special purpose instrument, AEP-5285, has been designed to simplify the measurement of 125I activities using a known technique in which the observed counting rate is compensated for self-absorption and any other uncertainties in the counting efficiency by making use of the coicidence properties of the radiation. The instrument contains pulse amplifiers, discriminators to define the energy regions of interest, and operational amplifier circuits to perform the necessary calculations automatically, and it displays an estimate of the source activity in becquerels. (auth)

287

Labeling of Annexin V with 125I and its biodistribution in mice  

International Nuclear Information System (INIS)

Annexin V is labeled with 125I by using Iodogen method and the biodistribution of which in mice is investigated. The labeling yield of 125I-Annexin V is 94.9% and its radio-chemical purity is over 99% after purification. The radioactivity uptake is the highest in kidney, followed in order by blood, liver, heart, lung and spleen; no uptake in brain; the lower in muscle and bone; The uptake of the selected tissues is decreased rapidly at 1 hour after injection except blood. The results show that it is a excellent imaging agent for diagnoses. (authors)

288

Tissue distribution of /sup 125/I-labelled bovine superoxide dismutase (SOD) in the rat  

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Bovine copper/zink superoxide dismutase (SOD) was labelled with /sup 125/I using the chloramine-T method. The tissue distribution of /sup 125/I-SOD (dose of SOD 5 mg/kg) was studied with whole-body and microautoradiography at various times after an intravenous injection. The distribution of /sup 125/I-SOD showed a remarkable organ specificity in that the localization of the enzyme to the kidneys and the urinary tract completely dominated the autoradiograms. The time pattern of localization of /sup 125/I-SOD also gives a clear picture of the renal handling of the enzyme in that, as a consequence of the renal elimination, the enzyme rapidly disappears from the circulation with an elimination half time of about 6 min. Up to 20 min. after the injection, there were high concentrations of /sup 125/I-SOD in the renal pelvis, ureter and urinary bladder showing that in addition to renal uptake there was an initial substantial urinary excretion of the enzyme. From the microautoradiography it is clear that the grains were exclusively localized over proximal tubular cells and tended to be concentrated at the luminal rather than the peritubular side of tubule. This would be compatible with renal uptake secondary to glomerular filtration of /sup 125/I-SOD, which is what one would expect from the renal handling of a protein with a molecular weight around 31,000 and an isoelectric point around pH 5.4. Pretreatment with a large dose of SOD (88 mg/kg) tended to competitively decrease the renal uptake of labelled SOD after 5 min. and apparently further increase its renal excretion. However, a noticable renal uptake of /sup 125/I-SOD was still apparent. The radioactivity in the kidneys subsided gradually, from 4 hours up to 48 hours with a parallel increase in the radioactivity in the thyroid, indicating metabolic degradation of /sup 125/I-SOD by tubular cells and suggesting ''retention'' by the kidney of at least some of the enzyme and/or its end products.

Odlind, B.; Appelgren, L.-E.; Bayati, A.; Wolgast, M.

1988-01-01

289

Optimization of the synthesis of a high specific activity 125 I-labelled hapten for radioimmunoassays  

International Nuclear Information System (INIS)

In this first report it is described the synthesis, separation and purification of the 2-radioiodinated histamine ''125 I-labelled histamine by a mixed anhydride reaction. About 75% incorporation of I''1125, from Na''125, I, was achieved with a molecular ratio of 1:1 mixed anhydride:histamine. The radiochemical purity of the conjugate by TLC was >99% and its theoretical specific activity, 3850 mu Ci/mug. Dissolved in ethanol and held at -20 degree centigree under darkness decomposition on storage did not exceed 1% per month

290

Synthesis of 4-[2-(4-azidophenyl)-5-(3-iodo-125I-phenyl)-1H-imidazol-4-yl]py ridine (SB 20678-[125I]), a pyridinyl imidazole cytokine inhibitor  

International Nuclear Information System (INIS)

The pyridinyl imidazole cytokine-suppressing anti-inflammatory drug (CSAID), SB 206718 (1) was required in 125I-labeled form for photoaffinity ligand studies. The target compound (SB 206718-[125I], [125I)1) was obtained via conversion of the highly functionalized 1 to a tributylstannyl derivative. Radioiododestannylation using Na125I in the presence of chloramine-T gave good radiochemical yields of the title compound (42-69%, four radiosyntheses) at high radiochemical purity (> 98%) after HPLC purification at specific activities of 1670-1736 Ci/mmol. (author)

291

Development of a high specific activity radioligand, 125I-LSD, and its application to the study of serotonin receptors  

International Nuclear Information System (INIS)

125I-Labeled receptor ligands can be synthesized with specific activities exceeding 2000 Ci/mmol, making them nearly 70-fold more sensitive in receptor site assays than (mono) tritiated ligands. We have synthesized and characterized 125I-lysergic acid diethylamide (125I-LSD), the first radioiodinated ligand for serotonin receptor studies. The introduction of 125I at the 2 position of LSD increased both the affinity and selectivity of this compound for serotonin 5-HT2 receptors in rat cortex. The high specific activity of 125I-LSD and its high ratio of specific to nonspecific binding make this ligand especially useful for autoradiographic studies of serotonin receptor distribution. We have found that 125I-LSD binds with high affinity to a class of serotonin receptors in the CNS of the marine mollusk Aplysia californica

292

Comparison of cyclosporine determinations in whole blood by three different methods. HPLC, 125I RIA and 3H RIA  

International Nuclear Information System (INIS)

The authors have analyzed and compared the cyclosporine concentrations in whole blood specimens from pediatric renal transplant patients using three different methods: high-performance liquid chromatography (HPLC) (5u C18 reverse-phase column), 3H radioimmunoassay (RIA), and 125I RIA (substituted 3H-tracer in Sandoz Kit with 125I tracer. Results obtained by the 125I RIA correlated well with results obtained by the 3H RIA. Both RIA methods had similar correlation with the HPLC method. The 125I RIA method showed higher sensitivity and greater precision than the 3H RIA method. The authors conclude that the 125I RIA method can be used for cyclosporine determination in whole blood specimens. The use of the 125I RIA provides a simple and rapid method with higher counting efficiency and less background quenching than the 3H RIA method, which requires cumbersome liquid scintillation counting procedures

293

Reduction of in Vivo Deiodination of Radioiodinated Antibodies Using N-Succinimidyl-4-[125I] Lodobenzoate  

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Full Text Available Human nonspecific polyclonal IgG was labeled with125I through direct and indirect labeling methods using chloramine-T and a non-Phenolic radioiodinated intermediate N-Succinimidyl-4-[125I] iodobenzoate (125I-SIB, respectively. Tissue distribution of radioiodinated IgG was assessed in normal and induced inflammation mice. Although, radioiodinated IgG accumulated in the inflammatory area, results showed decreased thyroid and stomach activity and improved inflammatory thigh-to-normal tissue ratios with the indirect labeling method (125I-IB-IgG compared with direct labeling method (125I-IgG, indicating reduced in vivo deiodination. These results indicate that the 125I-SIB is probably a preferable approach for labeling antibodies with iodine radioisotopes.

A Khalaj

2002-07-01

294

Spironolactone-associated digoxin radioimmunoassay interference. [/sup 3/H, /sup 125/I tracer techniques  

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Apparent digoxin was measured in the serum of 21 patients receiving spironolactone and in 21 controls, by use of a sequential-saturation /sup 3/H-radioimmunoassay (RIA) and an equilibrium /sup 125/I-RIA. No patient had been given digoxin for at least four weeks. ''Digoxin'' values in the former group were significantly (p < 0.05) higher than in the control group, and often were in or near the ''therapeutic'' range by the equilibrium /sup 125/I-RIA, but not by the sequential-saturation /sup 3/H-RIA. Canrenone (a major active metabolite of spironolactone) in the serum of the former group was measured by a newly developed liquid-chromatographic technique and correlated (r = 0.73) with ''digoxin'' concentrations by the /sup 125/I-RIA. However, external addition of canrenone to control serum in comparable concentrations did not cause appreciable ''digoxin'' values by the /sup 125/I-RIA. These findings suggest that other metabolites of spironolactone are responsible for the assay interference, the degree of which appears to depend on antibody specificity. Therefore, assay specificity should be established in clinical laboratories by using digoxin-free serum from patients ingesting spironolactone, and not by using spironolactone- or canrenone-fortified digoxin-free serum.

Silber, B.; Sheiner, L.B.; Powers, J.L.; Winter, M.E.; Sadee, W.

1979-01-01

295

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

International Nuclear Information System (INIS)

Intraocular malignant lesions are frequently encountered in clinical practice. Plaque brachytherapy represents an effective means of treatment for intraocular lesions. Recently Radiopharmaceutical Division, BARC, Mumbai, has indigenously fabricated reasonable-cost 125I sources. Here we are presenting the preliminary experience of dosimetry of sources, configuration of treatment planning system (TPS) and quality assurance (QA) for eye plaque therapy with Occu-Prosta 125I seeds, treated in our hospital, for a patient with ocular lesions. 125I seeds were calibrated using well-type chamber. BrachyVision TPS was configured with Monte Carlo computed radial dose functions and anisotropy functions for 125I sources. Dose calculated by TPS at different points in central axis and off axis was compared with manually calculated dose. Eye plaque was fabricated of 17 karat pure gold, locally. The seeds were arranged in an outer ring near the edge of the plaque and in concentric rings throughout the plaque. The sources were manually digitized on the TPS, and dose distribution was calculated in three dimensions. Measured activity using cross-calibrated well-type chamber was within ± 10% of the activity specified by the supplier. Difference in TPS-calculated dose and manually calculated dose was within 5%. Treatment time calculated by TPS was in concordance with published data for similar plaque arrangement. (author)

296

Photoaffinity labelling of the rat liver nuclear thyroid hormone receptor with [125I]triiodothyronine  

International Nuclear Information System (INIS)

[125I]Triiodothyronine (T3) was used as a photoreactive probe for the thyroid hormone nuclear receptor in photoaffinity labelling experiments. Autoradiograms of photolysis products electrophoresed on either one or two-dimensional gels showed that [125I]T3 covalently, but nonspecifically, labelled many proteins in the partially purified receptor preparations used. However, one of these proteins with an estimated molecular weight of 47,000 and an isoelectric point of approximately 6.2 +/- 0.5 pH units appears to be the thyroid hormone receptor, since, in contrast to the other proteins, its photoinduced labelling was blocked by concentrations of T3 and thyroxine (T4) similar to those that inhibit binding of [125I]T3 by the receptor in equilibrium binding assays. In addition, the isoelectric point of the photolabelled protein agrees with that determined in separate equilibrium isoelectric focusing studies. These results indicate that [125I]T3 can serve as a photoreactive probe for the thyroid hormone nuclear receptor, and they suggest that this receptor is a single polypeptide chain of molecular weight 47,000 with an isoelectric point of 6.2 +/- 0.5 pH units

297

Binding of 125I-human growth hormone to specific receptors in human cultured lymphocytes  

International Nuclear Information System (INIS)

The interaction of human growth hormone with human lymphocytes from an established culture (IM-9) was studied using 125I- human growth hormone. The binding of 125I-human growth hormone was rapid; with human growth hormone at 0.1 nM a steady state was observed in 90 min at 300. Bound labeled human growth hormone was dissociated rapidly by addition of excess unlabeled human growth hormone. Binding of 125I-human growth hormone to cultured lymphocytes was relatively insensitive to alterations in the pH and in the concentrations of Ca2+, Mg2+, EDTA. At 800 there was very little degradation of labeled human growth hormone or of the specific receptor sites. Tryptic digestion destroyed the capacity of cells to bind human growth hormone. The IM-9 cells bound all human growth hormone preparations but not unrelated hormones or nonprimate growth hormones. The binding of 125I-human growth hormone was inhibited 10 to 14 percent with 1 to 2 ng per ml of unlabeled human growth hormone and 50 percent with 30 to 40 ng per ml, well within the range of hormone concentrations in vivo. Analysis of steady state data revealed a single order of binding sites with an affinity constant of 1.3 x 109 M-1 and about 4000 binding sites per cell. Numerous human growth hormone preparations were assayed by use of this receptor system as well as by immunoassay and by bioassay in vivo. The po

298

Absorbed fractions for photons of 125I and 129I in the thyroid  

International Nuclear Information System (INIS)

Absorbed fractions for the thyroid have been calculated by Monte-Carlo simulation for the energies of photons emitted in the decay of 125I and 129I in the thyroid. A regression relation is provided which permits accurate calculation of these absorbed fractions for thyroid masses between 18 and 40 g, and photon energies between 27 and 40 keV. (author)

299

Examination of the method for measuring plasma cortisol by 125I-cortisol radioimmunoassay  

International Nuclear Information System (INIS)

The radioimmunoassay kit using 125I-cortisol for plasma cortisol was basically examined and was confirmed to have an excellent sensitivity, specificity, and reproducibility and to be very convenient. The present method was compared with the conventional flourescent method (Clark's method) and competitive protein binding analysis (CPBA), and a satisfactory correlation was obtained with both of them. (Chiba, N.)

300

Cortisol decreases 2[125I] iodomelatonin binding sites in the duck thymus  

International Nuclear Information System (INIS)

The immunosuppressive effect of chronic glucocorticoid treatment on 2[125I] iodomelatonin binding in the duck thymus was studied. Two-week-old ducks were injected intraperitoneally with either 1 mg of cortisol per day (experimental group) or an equivalent volume of vehicle (control group) in the middle of the light period for seven days. 2[125I] iodomelatonin binding assays were performed on thymic membranes. Cortisol injection reduced the body weight gain, size of the bursa of Fabricius and absolute weights of the primary lymphoid organs but had no effect on the spleen weights. The relative weights of the spleen were increased while those of the primary lymphoid organs were unchanged. The density of the thymus 2[125I] iodomelatonin binding sites was decreased while the affinity was not affected. The modulation of the thymic 2[125I] iodomelatonin binding sites by changes in the immune status of the duck suggests that these binding sites represent physiologically relevant melatonin receptors and that melatonin exerts its action on the lymphoid tissues directly. The authors findings support the hypothesis that the thymus is the target site for the immunomodulatory interactions between the pineal melatonin and the adrenal steroids. A possible inhibitory influence of adrenal steroids on the immuno-enhancing effect of melatonin is also suggested. 34 refs., 3 tabs

 
 
 
 
301

Human platelet ( sup 125 I)R-DOI binding sites. Characterization by in vitro autoradiography  

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We quantified binding sites for 2,5-dimethoxy-4-iodo-phenylisopropylamine (DOI), a 5-HT2 agonist and hallucinogen, in human platelets. We incubated sections from human platelet pellets with ({sup 125}I)R-DOI with or without 1 mumol/L ketanserin, followed by autoradiography and computerized microdensitometry. We corrected the values of binding density by the protein content of each section with a densitometric protein assay. The present method revealed a single class of high affinity binding sites for ({sup 125}I)R-DOI, with a Kd of 6.4 +/- 0.7 nmol/L and a Bmax of 100 +/- 10 fmol/mg protein. Kd and Bmax for ({sup 125}I)R-DOI determined by the classical membrane binding assay, were 2.7 +/- 0.4 nmol/L and 100 +/- 10 fmol/mg protein, respectively. The present method is precise, very sensitive, and allows the characterization of ({sup 125}I)R-DOI binding in sections obtained from as little as 3 ml of blood. Standardization is possible after correction by the protein content of each individual section.

Himeno, A.; Saavedra, J.M. (National Institute of Mental Health, Bethesda, MD (USA))

1990-02-01

302

Absolute intensity of internal bremsstrahlung from the electron capture decay of 125I  

International Nuclear Information System (INIS)

The absolute intensity of the internal bremsstrahlung spectrum accompanying the electron capture decay of 125I has been measured and compared to the recent calculation of Suric et al. The measured intensity above the 1s end point is found to be (86±10)% of the calculated intensity

303

Degradation of thyroxine 125I in normal Wistar AG rats, Atrichis mutants and haired hybrids  

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Several experiments conducted in male as well as castrated females rats have shown that the degradation of Thyroxine 125I is much faster in Atrichis as compared to haired normal and hybrid. The present study confirms earlier data on the reduced biological half-life of labeled thyroid hormone

304

OPTIMIZATION OF LABELLING CONDITIONS AND BIODISTRIBUTION OF 125I-SECNIDAZOLE AS A TARGETED AGENT  

International Nuclear Information System (INIS)

Secnidazole was effectively labelled with125I. The labelling process was performed through electrophilic substitution reaction of a proton in the imidazole ring with iodonium ion (I +). The iodonium ion was produced by the oxidation of iodide ion using chloramine-T as oxidizing agent. A maximum yield of 125I-secnidazole was obtained at 450C for 30 minutes and pH 7. The reaction was found strongly dependent on the reaction temperature. The 12'5I-secnidazole was able to localize bacterial and sterile inflammations induced by Escherichia coli and turpentine oil, which suggest that its accumulation is due to increase of blood flow together with enhancement of vascular permeability in inflamed muscle either septic or sterile. The target to non-target muscle ratios were 2.6, 3.3 and 6.5 at 2, 6 and 24 hours, respectively, indicting a higher binding affinity of 12'5I-secnidazole to the inflammation induced with bacteria

305

Distribution of 125I-thyroxine in different organs and tissues of dietically obese rats  

International Nuclear Information System (INIS)

The distribution of 125I-thyroxine (% dose/g tissue; tissue/plasma radioactivity ratio) was investigated in different tissues of 28-week-old obese Wistar rats. Obesity was induced by high-fat diet (HFD) and confirmed by carcass analysis; in heavy obese animals the relative and absolute fat content is increased twofold and threefold, respectively, compared to control rats fed on a low-fat diet (LFD). Heavy HFD rats exhibit diminished 125I-T4 distribution in the 'slow pool' (fat tissue, muscle) and unchanged values in the 'fast pool' (liver, kidneys) in comparison with LFD rats with low body weight. The differences in distribution presented here are not caused by the diet per se, but they are the consequence of the obesity of the animal, because no differences in the 125I-T4 distribution were found in the 125I-T4 between HFD and LFD rats with relatively equal body weight and body composition. The reduced T4 distribution in the fat tissue of obese rats is discussed in connection with possibly decreased lipolysis in this tissue and possible causal participation in the beginning of obesity. (author)

306

Tyrosine A14[125I]monoiodoinsulin: preparation, biologic properties, and long-term stability  

International Nuclear Information System (INIS)

grated with insulin when subjected to gel filtration on Sephadex G-50, 4% was in the void volume, and nothing in the total column volume or later. Binding to receptors was indistinguishable from that obtained at time zero. It is concluded that Tyr A14[125I]monoiodoinsulin represents an advance in biologic work as compared with previous tracers for insulin

307

Solid-phase receptor binding assay for 125I-hCG  

International Nuclear Information System (INIS)

A solid-phase radioligand-receptor assay (RRA) to measure the binding of 125I-labelled human chorionic gonadotropin (125I-hCG) to target cell membranes has been developed. The binding of 125I-hCG to membranes immobilized on the wells of microtitration plates reached a maximum at about 3 hours at 37 degrees C, was saturable, displayed a high affinity (Ka = 2.4 X 10(9) M-1) and was specifically inhibited by unlabelled hCG. In comparison with RRAs carried out with membranes in suspension, the solid-phase RRA is significantly simpler and much faster to perform as it avoids centrifugation or filtration procedures. The solid-phase RRA was adapted profitably to process large numbers of samples at the same time. It proved particularly useful as a screening assay to detect anti-hCG monoclonal antibodies with high inhibitory activity for binding of 125I-hCG to its receptors

308

Research on apoptosis of MCF-7 cells induced by continuous irradiation by 125I seeds  

International Nuclear Information System (INIS)

Objective: To detect the apoptotic rate and the changes of expressions of Bcl-2 and Bax in MCF-7 cells continuously irradiated with low dose rate ?-rays from 125I seeds. Methods: MCF-7 cells were exposed to the radiation for 72 hours from model 6711 125I seeds with an apparent activity of 27.75 MBq. Then, RT-PCR and Western blot were used to detect the expressions of Bcl-2 and Bax in MCF-7 cells. FCM and Annexin V assay were performed to detect the apoptotic rate of MCF-7 cells. Results: Higher expression of Bcl-2 and lower expression of Bax in irradiated MCF-7 cells compared to those in the control cells were detected. FCM and Annexin V assay showed a significant increase of apoptotic rate in MCF-7 cells after continuous irradiation by 125I seeds. Conclusion: Continuous irradiation with 125I increases the apoptotic rate of MCF-7 cells, and this increase may be induced by decreased ratio of Bcl-2/Bax. (authors)

309

Determination of bone density via 125I-densitometry in idiophathic scoliosis  

International Nuclear Information System (INIS)

The aim of the present study was to find out whether idiopathic scoliosis is associated with a general reduction of the calcium salt content of the bones. The study was conducted in a scoliosis patient group of 48 individuals, using 125I densitometry. (orig.)

310

Interaction of /sup 125/I-protein a with erythrocyte-bound IgG  

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The molar combining ratio of /sup 125/I-PrA to RBC-bount /sup 125/I-labeled IgG anti-D was 0.72 +/- 0.044. There was a significant decrease in the PrA-to-IgG combining ratio when anti-D was bound to protease-modified RBCs or to unmodified RBCs sensitized at low ionic strength, 0.49 +/- 0.034 and 0.56 +/- 0.006, respectively. These findings indicate that the interaction of RBC-bound IgG with PrA may be influenced by alterations in membrane structure, surface density, and distribution of the IgG receptor and possibly other steric factors. The quantity of RBC-bound IgG on RBCs sensitized with unlabeled serum anti-D and anti-Kell could be quantitatively assessed and correlated with antiglobulin agglutinability. Unlabeled alloantibodies were detected with the /sup 125/I-PrA at IgG densities lower than those detectable with the standard antiglobulin test. /sup 125/I-PrA, in contrast to the antiglobulin reaction, has the potential of providing increased sensitivity as well as quantitative data in assessing IgG alloantibody- or autoantibody-sensitized RBCs.

Gray, L.S.; Masouredis, S.P.

1982-03-01

311

Interaction 125I-protein A with erythrocyte-bound IgG  

International Nuclear Information System (INIS)

The molar combining ratio of 125I-PrA to RBC-bound 125I-labeled IgG anti-D was 0.72 +/- 0.044. There was a significant decrease in the PrA-to-IgG combining ratio when anti-D was bound to protease-modified RBCs or to unmodified RBCs sensitized at low ionic strength, 0.49 +/- 0.034 and 0.56 +/- 0.006, respectively. These findings indicate that the interaction of RBC-bound IgG with PrA may be influenced by alterations in membrane structure, surface density, and distribution of the IgG receptor and possibly other steric factors. The quantity of RBC-bound IgG on RBCs sensitized with unlabeled serum anti-D and anti-Kell could be quantitatively assessed and correlated with antiglobulin agglutinability. Unlabeled alloantibodies were detected with the 125I-PrA at IgG densities lower than those detectable with the standard antiglobulin test. 125I-PrA, in contrast to the antiglobulin reaction, has the potential of providing increased sensitivity as well as quantitative data in assessing IgG alloantibody- or autoantibody-sensitized RBCs

312

Interaction of 125I-protein a with erythrocyte-bound IgG  

International Nuclear Information System (INIS)

The molar combining ratio of 125I-PrA to RBC-bount 125I-labeled IgG anti-D was 0.72 +/- 0.044. There was a significant decrease in the PrA-to-IgG combining ratio when anti-D was bound to protease-modified RBCs or to unmodified RBCs sensitized at low ionic strength, 0.49 +/- 0.034 and 0.56 +/- 0.006, respectively. These findings indicate that the interaction of RBC-bound IgG with PrA may be influenced by alterations in membrane structure, surface density, and distribution of the IgG receptor and possibly other steric factors. The quantity of RBC-bound IgG on RBCs sensitized with unlabeled serum anti-D and anti-Kell could be quantitatively assessed and correlated with antiglobulin agglutinability. Unlabeled alloantibodies were detected with the 125I-PrA at IgG densities lower than those detectable with the standard antiglobulin test. 125I-PrA, in contrast to the antiglobulin reaction, has the potential of providing increased sensitivity as well as quantitative data in assessing IgG alloantibody- or autoantibody-sensitized RBCs

313

Interaction /sup 125/I-protein A with erythrocyte-bound IgG  

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The molar combining ratio of /sup 125/I-PrA to RBC-bound /sup 125/I-labeled IgG anti-D was 0.72 +/- 0.044. There was a significant decrease in the PrA-to-IgG combining ratio when anti-D was bound to protease-modified RBCs or to unmodified RBCs sensitized at low ionic strength, 0.49 +/- 0.034 and 0.56 +/- 0.006, respectively. These findings indicate that the interaction of RBC-bound IgG with PrA may be influenced by alterations in membrane structure, surface density, and distribution of the IgG receptor and possibly other steric factors. The quantity of RBC-bound IgG on RBCs sensitized with unlabeled serum anti-D and anti-Kell could be quantitatively assessed and correlated with antiglobulin agglutinability. Unlabeled alloantibodies were detected with the /sup 125/I-PrA at IgG densities lower than those detectable with the standard antiglobulin test. /sup 125/I-PrA, in contrast to the antiglobulin reaction, has the potential of providing increased sensitivity as well as quantitative data in assessing IgG alloantibody- or autoantibody-sensitized RBCs.

Gray, L.S.; Masouredis, S.P.

1982-03-01

314

Effects of age and sex on 125I-?-CIT binding to DAT  

International Nuclear Information System (INIS)

Objective: To investigate effects of age and sex on 125I-?-CIT binding to dopamine transporter (DAT). Methods: Detection of the differences in 125I-?-CIT binding kinetics in vivo between 6 week and 6 month old KM mice, and the differences of in vivo binding between female and male, and between 3 month and 12 month old SD rats.The animals were sacrificed 2 h after injection. Results: Uptake of 125I-?-CIT in the striatum, frontal cortex, parietal cortex, temporal cortex, occipital cortex, hippocampus, brain stem and whole brain in 6 week old mice was higher than that in 6 month old mice, and similar uptake pattern happened in between 3 month old and in 12 month old SD rats. In 12 months old SD rats, female rats had higher uptake in the striatum than male rats did. Conclusions: Young mice and rats have a higher uptake of 125I-?-CIT in the striatum than aged ones and female rats have a higher uptake than male ones do. This result indicates that the density of DAT in rat or mouse striatum may be reduced with aging

315

Preparation of 125I labelled nerve growth factor and study of its pharmacokinetics  

International Nuclear Information System (INIS)

125I-Nerve growth factor (125I-NGF) with more than 95% of radiochemical purity is prepared by chloramine-T method. After I.V. and I.M. injection of 125I-NGF, pharmacokinetics of NGF in mice is determined by SDS-PAGE method. The results show that concentration-time curves after I.V. injection are fitted to a 2-compartment model are those after I.M. injection are fitted to a 1-compartment model. After I.V. injection of 25 ?g/kg, the elimination half life (t1/2(?)) is 3.65 h. After I.M. injection of 75, 25, 10, 3.3 ?g/kg, t1/2(?) is 1.79, 2.25, 2.30, 3.24 h, respectively. The mean plasma clearance (CLs) is 0.37 L/(h·kg), the appearance volume of distribution (Vd) is 1.18 L/kg and the mean residence time (tr-bar) in mice is 2.78 h. The pharmacokinetics of 125I-NGF in mice is useful for clinical trial

316

Binding and degradation of 125I-gastrin by plasma membranes from homogenized rat gastric mucosa  

International Nuclear Information System (INIS)

a of the stomach could bind 125I-gastrin specifically and with a Ksub(d) of 0.8 nM (Scatchard analysis). However, micromolar concentrations of unlabelled gastrin were required to inhibit half maximal binding of the tracer. The tracer binding was unaffected by secretin, slightly reduced by a CCK-9 analogue, and more markedly reduced by pentagastrin

317

Synthesis of the 123I- and 125I-labeled cholinergic nerve marker (-)-5-iodobenzovesamicol  

International Nuclear Information System (INIS)

The highly toxic curaremimetic and cholinergic neuron marker (-)-5-iodobenzovesamicol (IBVM) has been labeled with iodine-125 and iodine-123. [125I]IBVM, suitable for animal distribution and ex vivo autoradiographic studies, was synthesized by solid-state exchanger; isolated yields were 65-89% with specific activities in the range of 130-200 Ci/mmol. The synthesis of no-carrier-added (-)-5-[125I]IBVM from the corresponding chiral (-)-5-(tri-n-butyltin) derivative using Na125I was evaluated using the oxidants H2O2, peracetic acid and chloramine-T. Both peracetic acid and chloramine-T gave good yields (70-95%). However, when Na123I was utilized, acceptable yields of [123I]IBVM were obtained only with chloramine-T. Distribution analyses of [125I]IBVM and [123I]IBVM in mice 4 h following intravenous administration show essentially equivalent concentrations of the two tracers in the four brain regions sampled. The exceptionally high specific activity of [123I]IBVM has made possible the evaluation of this radiotracer in humans. (Author)

318

Preparation of 125I labelled progesterone-11?-hemisuccinate tyrosine methyl esther  

International Nuclear Information System (INIS)

Progesterone assay in serum samples is best carried out by radioimmunoassay due to its high sensitivity, specificity and simplicity. An essential reagent for the assay is 125I-labelled progesterone. Labeling of progesterone-11?-hemisuccinate-TME is carried out using the lactoperoxidase method by reacting progesteron 11 alpha hemisuccinate TME and Na125I with LPO in the presence of trace amount of hydrogen peroxide as the catalyst. The labelling efficiency obtained was (88.8%±4.7)% with a specific activity of about 400 ?Ci/?g. Purification by thin layer chromatography yielded a radiochemical purity of more than 90%. Determination of immunonoreactivity showed that the bound fraction was (56.3±3.9)%. The 125I labelled compound in ethanolic solution was shown to be stable for 3 months when stored at -20oC based on evaluation of its immunoreactivity and the non specific binding value. 125I labeled progesterone solution is phosphate buffer ready-for-use in radioimmunoassay were stable for 14 days when stored at 0oC. (author). 4 refs., 3 tabs., 3 figs

319

In vitro root caries progression measured by 125I absorptiometry: comparison with chemical analysis  

International Nuclear Information System (INIS)

Radiation from a 125I source and a non-image-forming detector was used for non-destructive measurements of root caries progression. Blocks were cut parallel to the cementum surface of unexposed human roots. These blocks were then individually demineralized in under-saturated calcium phosphate solutions over an 84-hour period. In order for the in vitro root surface demineralization to be followed, the changes in transmission (delta T) through the blocks were measured, by 125I absorptiometry, eight times during the course of the experiment. Chemical analyses of the calcium output (delta Ca) from the blocks into the demineralizing solutions were also performed, and the rate of demineralization (Vdem) was calculated from these values. The precision of 125I absorptiometry was calculated from 176 duplicate transmission measurements, and the coefficient of variation was found to be 0.20%. The correlation coefficient between delta T and total delta Ca for each of 22 cementum/dentin blocks ranged between r = 0.934 and r = 0.998. The progression of root hard-tissue lesions observed by these two methods and by the calculated Vdem was found to be proportional to the square and cubic roots of time. The study shows that 125I absorptiometry can be used for continuous non-destructive measurements of root hard-tissue demineralization in vitro

320

Apparent volumes of distribution of 125I-lothalamate and inulin in chickens (38781)  

International Nuclear Information System (INIS)

The suitability of utilizing 125I-iothalamate to estimate the volume of extracellular fluid was assessed in ureterally ligated chickens. Subsequent to intravenous administration the movement of labeled iothalamate from the plasma compartment follows closed two-compartment kinetics and equilibration between vascular and extravascular phases is attained in about 20 minutes. The volume of distribution of 125I-iothalamate prior to and following the infusion of 0.15 M NaCl (equal to 15 percent of the estimated ECFV) averaged 23.6 +- 0.61 and 28.4 +- 0.22 percent of the body weight, respectively. The observed postsaline labeled iothalamate space did not differ statistically from the expected value. When administered simultaneously inulin penetrates into an apparent volume that is 75 percent of the labeled iothalamate space after 60 minutes. The content of 125I-iothalamate is relatively high in liver and kidney tissue and suggests that these are major sites where removal of the indicator from plasma occur. It is suggested that 125I-iothalamate, under appropriate conditions, could be used to measure the plasma volume and the extravascular fluid with which plasma is in rapid diffusion equilibrium. (U.S.)

 
 
 
 
321

Highly sensitive determination of alkenylglycerophospholipids using radioactive triiodide ion (125I3-)  

International Nuclear Information System (INIS)

Although several methods for determination of alkenyl type glycerophospholipids (i.e., plasmalogens) have been reported so far, any methods were insufficient because of complicated procedure and from accurate and sensitive point of view. It was also impossible by the former methods to measure intact alkenyl type glycerophospholipids separating from other glycerophospholipids such as diacyl type glycerophospholipids. In the present study, for the purpose of developing highly sensitive and convenient determination of alkenyl type glycerophospholipids, we investigated HPLC method using radioactive iodine, based on the fact that triiodide (I-) ion (I3-) specifically reacts with vinyl ether bonds (-CH2-O-CH=CH-) of alkenyl type glycerophospholipids in methanol solution. A commercial radioactive iodine (125I-) could be safely (almost 100% recovery) and efficiently (70-80%) converted to radioactive triiodide (I-) ion (125I3-), which is capable of binding to alkenyl type glycerophospholipids, by oxidizing 125I- with hydrogen peroxide (H2O2) in methanol under acid condition (pH 5.5 - 6.0). I3- reacted with alkenyl type glycerophospholipids at the molar ratio of 1:1, and one or two moles of vinyl ether bonds were involved in binding with iodine per one mole of iodine atom. We could detect alkenyl type glycerophospholipids at high sensitivity such that the lower detection limit of concentration is several ten pmol using 125I reagents (1.85 MBq/mL) prepared in this study. (author)

322

Cortisol decreases 2[[sup 125]I] iodomelatonin binding sites in the duck thymus  

Energy Technology Data Exchange (ETDEWEB)

The immunosuppressive effect of chronic glucocorticoid treatment on 2[[sup 125]I] iodomelatonin binding in the duck thymus was studied. Two-week-old ducks were injected intraperitoneally with either 1 mg of cortisol per day (experimental group) or an equivalent volume of vehicle (control group) in the middle of the light period for seven days. 2[[sup 125]I] iodomelatonin binding assays were performed on thymic membranes. Cortisol injection reduced the body weight gain, size of the bursa of Fabricius and absolute weights of the primary lymphoid organs but had no effect on the spleen weights. The relative weights of the spleen were increased while those of the primary lymphoid organs were unchanged. The density of the thymus 2[[sup 125]I] iodomelatonin binding sites was decreased while the affinity was not affected. The modulation of the thymic 2[[sup 125]I] iodomelatonin binding sites by changes in the immune status of the duck suggests that these binding sites represent physiologically relevant melatonin receptors and that melatonin exerts its action on the lymphoid tissues directly. The authors findings support the hypothesis that the thymus is the target site for the immunomodulatory interactions between the pineal melatonin and the adrenal steroids. A possible inhibitory influence of adrenal steroids on the immuno-enhancing effect of melatonin is also suggested. 34 refs., 3 tabs.

Poon, A.M.S.; Liu, Z.M.; Tang, F.; Pang, S.F. (Univ. of Hong Kong (China))

1994-03-01

323

Preclinical pharmacological study on 125I-ADAM as a serotonin transporter ligand  

International Nuclear Information System (INIS)

etabolism. Toxicity trial showed that the dose per kilogram administered to mice was 1000 times greater than that to humans, assuming a weight of 50 kg. Conclusion: These data suggest that 125I-ADAM may be useful for SPECT imaging of SERT binding sits in the brain. (authors)

324

The preparation of 125I-labelled bile acid ligands for use in the radioimmunoassay of bile acids  

International Nuclear Information System (INIS)

A general method for the preparation of 125I-labelled bile acid-histamine or 125I-labelled bile acid-tyramine conjugates is presented. The method is simple, quick and produces ligands in good yield (30%). The characteristics of a radioimmunoassay for conjugated chenodeoxycholic acid, based on an 125I-labelled ligand prepared by the method, are also described. The assay produces values for fasting serum concentrations of conjugated chenodeoxycholic acid that agree well with previous data. (Auth.)

325

Dosimetric analysis of 123I, 125I and 131I in thyroid follicle models  

Science.gov (United States)

Background Radioiodine is routinely used or proposed for diagnostic and therapeutic purposes: 123I, 125I and 131I for diagnostics and 125I and 131I for therapy. When radioiodine-labelled pharmaceuticals are administered to the body, radioiodide might be released into the circulation and taken up by the thyroid gland, which may then be an organ at risk. The aim of this study was to compare dosimetric properties for 123I, 125I and 131I in previously developed thyroid models for man, rat and mouse. Methods Dosimetric calculations were performed using the Monte Carlo code MCNPX 2.6.0 and nuclear decay data from ICRP 107. Only the non-radiative transitions in the decays were considered. The S value was determined for the cell nuclei in species-specific thyroid follicle models for mouse, rat and man for different spatial distributions of radioiodine. Results For the species-specific single follicle models with radioiodine homogeneously within the follicle lumen, the highest S value came from 131I, with the largest contribution from the ? particles. When radioiodine was homogeneously distributed within the follicle cells or the follicle cell nucleus, the highest contribution originated from 125I, about two times higher than 123I, with the largest contribution from the Auger electrons. The mean absorbed dose calculated for our human thyroid multiple follicle model, assuming homogenous distribution of for 123I, 125I, or 131I within the follicle lumens and follicle cells, was 9%, 18% and 4% higher, respectively, compared with the mean absorbed dose according to Medical Internal Radiation Dose (MIRD) formalism and nuclear decay data. When radioiodine was homogeneously distributed in the follicle lumens, our calculations gave up to 90% lower mean absorbed dose for 125I compared to MIRD (20% lower for 123I, and 2% lower for 131I). Conclusions This study clearly demonstrates the importance of using more detailed dosimetric methods and models than MIRD formalism for radioiodine, especially 123I and 125I, in the thyroid. For radioiodine homogeneously distributed in the follicle lumens our calculations for the human multiple follicle models gave up to 90% lower mean absorbed dose compared with MIRD formalism. PMID:25006543

2014-01-01

326

Estado da arte do procedimento percutâneo: paciente octogenário submetido com sucesso, em apenas uma sessão, a valvotomia pulmonar, implante de stent coronário e implante de marcapasso definitivo / State of the art percutaneous procedure: octogenarian patient successfully submitted, in a single session, to a pulmonary valvotomy, coronary stent implant and permanent pacemaker implant  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese É relatado caso de paciente de 82 anos, portador de insuficiência renal leve, estenose valvar pulmonar (EVP) severa, estenose severa de artéria descendente anterior e bloqueio atrioventricular total, submetido a angioplastia coronária com implante de stent coronário, valvotomia pulmonar e implante d [...] e marcapasso definitivo no mesmo procedimento, com sucesso. Abstract in english This report describes a case involving an 82 year old patient with mild renal insufficiency, severe pulmonary valve stenosis (PVS), severe anterior descending artery stenosis and complete atrioventricular block, who successfully underwent, in a single session, coronary angioplasty and a stent implan [...] t, pulmonary valvotomy and a permanent pacemaker implant.

Wilson Albino, Pimentel Filho; Milton de Macedo, Soares Neto; Gil Vicente, Cividanis; Rubens Vaz, Feijó Júnior.

327

Anti-tumor effects of Egr-IFN ? gene therapy combined with 125I-UdR radionuclide therapy  

International Nuclear Information System (INIS)

Objective: To explore the anti-tumor effects of Egr-IFN? gene therapy combined with 125I-UdR radionuclide therapy in mice bearing H22 hepatocarcinoma and its mechanism. Methods: The recombinant plasmid pcDNAEgr-IFN? mixed with liposome was injected into tumor. 48 h later, 370 kBq 125I-UdR was injected into tumor. The tumor growth rates at different times were observed. After 3 d gene-radionuclide therapy, the concentration of IFN? in cytoplasm of H22 cells and cytotoxic activities of splenic CTL of the mice in different groups were examined. Results: The tumor growth rates of pcDNAEgr-IFN? + 125I-UdR group were obviously lower than those of control group, 125I-UdR group and pcDNAEgr-1 + 125I-UdR group 6-15 d after gene-radionuclide therapy. IFN? protein was found in cytoplasm of H22 cells in pcDNAEgr-IFN? + 125I-UdR group after 3 d gene-radionuclide therapy. Cytotoxic activity of splenic CTL in pcDNAEgr-IFN? + 125I-UdR group was significantly higher than that in the other groups (P125I-UdR radionuclide therapy are better than those of 125I-UdR therapy. (authors)

328

Cytotoxic effects of 125I-labeled PBZr ligand PK 11195 in prostatic tumor cells: therapeutic implications  

International Nuclear Information System (INIS)

The effect of [125I]PK 11195 was examined in human prostatic tumor cells (DU 145) in culture and compared with Na[125I] and non-radioactive PK 11195. [125I]PK 11195 was clearly cytocidal. The data for dose-related cell survival with [125I]PK 11195 showed a linear relationship. Na[125I] or non-labeled PK 11195 at similar concentrations did not lead to any cell killing. The uptake of [125I]PK 11195 and [3H]PK 11195 in cells was very similar. Fragmentation of DNA measured by agarose gel electrophoresis showed that exposure of DU 145 cells to [125I]PK 11195 for 1, 4 or 24 h caused no fragmentation. These results indicate that nuclear DNA is not the prime binding site for [125I]PK 11195, which is consistent with the presence of specific peripheral benzodiazepine receptors (PBZr) in the mitochondria. The cell killing effect of [125I]PK 11195 suggests the use of PBZr ligand for radiotherapy

329

[125I]protein A: a tracer for general use in immunoassay  

International Nuclear Information System (INIS)

An immunoassay method was developed in which 125I-labeled Protein A ([125I]PA) of high specific activity (100 Ci/mmole) and functional activity >= 85%) served as a general tracer. Antigen (or hapten) was immobilized by covalent binding to a solid bead support. Aliquots of the appropriate beads were incubated with antibody (either purified IgG fraction or whole antiserum), washed with buffer, then incubated with [125I]PA. The amount of [125I]PA bound to the antibody-coated beads was a measure of antibody binding. The ability of antigen (or hapten) in the fluid phase to inhibit the binding of antibody under optimal conditions, measured as inhibition of [125I]PA binding, served as the basis for quantification in the assay. The method was applied to 3 antigens (human chorionic gonadotropin (HCG), human immunoglobulin M (IgM) and goat immunoglobulin G (IgG)) and to methotrexate as an example of a hapten. Optimal assay conditions were developed and, in each case, picomole levels or less of the homologous ligand could be detected. Antibody specificity was determined by measuring the ability of compounds related to the antigen or hapten to act as inhibitors. Levels of HCG in urine from pregnant women and levels of IgM in normal human sera were determined by this method. The assay required only approximately 3 h to perform, gave accurate reproducible results, and was at least as sensitive as other available immunoassay methods (e.g. radioimmunoassay). (Auth.)

330

99mTc-albumin can replace 125I-albumin to determine plasma volume repeatedly  

DEFF Research Database (Denmark)

OBJECTIVE: Plasma volume assessment may be of importance in several disorders. The purpose of the present study was to compare the reliability of plasma volume measurements by technetium-labeled human serum albumin ((99m)Tc-HSA) with a simultaneously performed plasma volume determination with iodine-labeled human serum albumin ((125)I-HSA). MATERIALS AND METHODS: In 15 healthy volunteers, simultaneous plasma volume measurements with (99m)Tc-HSA and (125)I-HSA were performed after ½ hour in the supine position. Blood samples were obtained 10, 15, 20, and 30 minutes after the injection for accurate retropolation from the plasma counts to time zero to correct for leakage of the isotopes from the circulation. RESULTS: The mean difference (bias) between plasma volume measured with (125)I-albumin and (99m)Tc-albumin was 8 ml (0.1 ml/kg) with limits of agreement (bias ±1.96 SD) ranging from -181-196 ml (-2.3-2.5 ml/kg). The tracer disappearance rate was significantly higher with (99m)Tc-albumin (-23.1±7.1%/h) thanwith (125)I-albumin (-6.7±3.6%/h) (p <0.001). CONCLUSION: This study demonstrates that (99m)Tc-HSA can replace (125)I-HSA for single measurements of plasma volume in healthy volunteers. It needs to be emphasized however, that repeated blood sampling for 1/2 hour after injection of the tracer is required to correct for the disappearance of (99m)Tc and (99m)Tc-HSA from the circulation.

Bonfils, Peter K; Damgaard, Morten

2012-01-01

331

Fragmentation of Nimotuzumab for Preparation of 125I-F(ab’2-Nimotuzumab as a Precursor for Preparing 125I-F(ab’2-Nimotuzumab-NLS Radiopharmaceutical for Cancer Therapy  

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Full Text Available Nimotuzumab is an anticancer agent which belongs to the inhibitor group of Epidermal Growth Factor Receptor (EGFR. This monoclonal antibody has a relatively high molecular weight which makes slow penetration on tumor cell, as concequence, it is less attractive in imaging kinetics, and potentially elicits antibodies respons. Therefore in this study nimotuzumab was fragmented to form bivalent antibody [F(ab’2] and then labeled with 125I to form 125I-F(ab’2-nimotuzumab which can be used further as a precursor for preparing 125I-F(ab’2-nimotuzumab-NLS (NLS = nuclear localizing sequences radiopharmaceutical for radioimmunotherapy. The aims of this study were to obtain characteristics of 125I-F(ab’2-nimotuzumab by comparing with the 125I labeled-intact nimotuzumab (125I-nimotuzumab. This study was initiated by purifying nimotuzumab by mean of dialysis. The purified nimotuzumab was then fragmented by using pepsin. The F(ab'2-nimotuzumab formed was then purified from its by-products which formed in fragmentation process by using a PD-10 column (consisted Sephadex G25. The intact nimotuzumab and its F(ab’2 fragment were then labeled with the 125I to form 125I-nimotuzumab and 125I-F(ab’2-nimotuzumab. The radiochemical purity are 98.27 % and 93.24 % ,respectively. Stability test results show that, both of 125I-nimotuzumab and 125I-F(ab’2-nimotuzumab more stable at 4 °C than at room temperature storage and 37 °C

R.D. Haryuni

2014-04-01

332

Comparison of (/sup 125/I)HIPDm and (/sup 125/I)iodoantipyrine in quantifying regional cerebral blood flow in rats  

Energy Technology Data Exchange (ETDEWEB)

We determined regional cerebral blood flow (rCBF) using (/sup 125/I)HIPDm (N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamin e) and (/sup 125/I)iodoantipyrine autoradiography under control and pathologic conditions (hypercapnia (acidosis), hypocapnia (alkalosis), and disrupted blood-brain barrier) conditions in 35 rats. In control rats, HIPDm rCBF (indicator fractionation method, n = 5) was lower than the corresponding IAP rCBF (diffusible indicator method, n = 4), most notably in the infratentorial regions and subcortical nuclei. In hypercapnia, rCBF increased by 100% and 37% in the HIPDm (n = 5) and IAP (n = 5) groups, respectively. In hypocapnia, IAP rCBF (n = 4) decreased 34% but HIPDm rCBF (n = 4) did not change. Following disruption of the blood-brain barrier by intracarotid infusion of mannitol in eight rats, both radiotracers (HIPDm n = 4, IAP n = 4) showed decreased rCBF to regions of disruption as defined by trypan blue extravasation. Our work indicates that modeling HIPDm uptake to quantify rCBF using the indicator fractionation method will underestimate blood flow and that HIPDm kinetics are influenced by compartmental pH dynamics that will limit the accuracy of this method in quantifying rCBF in pathologic conditions.

Albright, R.E. Jr.; Friedman, A.H.; Fram, E.K.; Harbury, O.L.; Molter, B.A.; Skatoff, J.H.; Harris, C.C.; Coleman, R.E.; Drayer, B.P.

1988-11-01

333

In vivo binding of 125I-LSD to serotonin 5-HT2 receptors in mouse brain  

International Nuclear Information System (INIS)

The binding of 125I-LSD (2-[125I]-lysergic acid diethylamide) was studied in various mouse brain regions following intravenous injection of the radioligand. The high specific activity of 125I-LSD enabled the injection of low mass doses (14ng/kg), which are well below the threshold for induction of any known physiological effect of the probe. The highest levels of 125I-LSD binding were found in the frontal cortex, olfactory tubercles, extra-frontal cortex and striatum while the lowest level was found in the cerebellum. Binding was saturable in the frontal cortex but increased linearly in the cerebellum with increasing doses of 125I-LSD. Serotonergic compounds potently inhibited 125I-LSD binding in cortical regions, olfactory tubercles, and hypothalamus but had no effect in the cerebellum. Dopaminergic compounds caused partial inhibition of binding in the striatum while adrenergic compounds were inactive. From these studies the authors conclude that 125I-LSD labels serotonin 5-HT2 receptor sites in cortical regions with no indication that other receptor sites are labeled. In the olfactory tubercles and hypothalamus, 125I-LSD labeling occurs predominantly or entirely at serotonic 5-HT2 sites. In the striatum, 125I-LSD labels approximately equal proportions of serotonergic and dopaminergic sites. These data indicate that 125I-LSD labels serotcate that 125I-LSD labels serotonin receptors in vivo and suggests that appropriate derivatives of 2I-LSD may prove useful for tomographic imaging of serotonin 5-HT2 receptors in the mammalian cortex

334

In vitro characterization of the influx of 3-[{sup 125}I]iodo-L-{alpha}-methyltyrosine and 2-[{sup 125}I]iodo-L-tyrosine into U266 human myeloma cells: Evidence for System T transport  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study was to investigate the cellular uptake mechanisms responsible for the accumulation of 3-[{sup 125}I]iodo-L-{alpha}-methyltyrosine ({sup 125}I-3-IMT) and 2-[{sup 125}I]iodo-L-tyrosine ({sup 125}I-2-IT), two radiotracers for metabolic tumor imaging, using single-photon emission tomography, into U266 human myeloma cancer cells. Time course and concentration dependency of {sup 125}I-3-IMT uptake was assessed. Kinetic parameters were calculated using an Eadie Hofstee plot. A set of competitive inhibitors of the main amino acid transport systems was used for the discrimination of the transporters responsible for the uptake of {sup 125}I-3-IMT and {sup 125}I-2-IT. Protein incorporation of both tracers was determined using acid precipitation. The measured maximum velocity for {sup 125}I-3-IMT transport was 4.199 nmol per mg protein 20 s{sup -1}, and the Michaelis constant was 107.9 {mu}M. Addition of 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH), a competitive inhibitor of System L, reduced the influx by 39.0{+-}3.3% for {sup 125}I-3-IMT and 66.3{+-}0.9% for {sup 125}I-2-IT. The BCH-insensitive influx was further reduced by Tryptophan (Trp) by 43.8{+-}3.5% for {sup 125}I-3-IMT and 15.3{+-}1.3% for {sup 125}I-2-IT. This suggests involvement of System T transport. We measured <2% of radioactivity in the acid precipitable fractions of both tracers with no increase in time. We conclude that the influx of {sup 125}I-3-IMT and {sup 125}I-2-IT into U266 human myeloma cells is mediated by both System L and System T amino acid transporters. The kinetic parameters suggest that elevated plasma levels of aromatic amino acids will reduce {sup 123}I-3-IMT uptake in myeloma patients. Both tracers do not enter protein synthesis significantly.

Lahoutte, T. E-mail: nucglet@az.vub.ac.be; Caveliers, V.; Dierickx, L.; Vekeman, M.; Everaert, H.; Mertens, J.; Bossuyt, A

2001-02-01

335

Monte Carlo dosimetry for 125I and 103Pd eye plaque brachytherapy with various seed models  

International Nuclear Information System (INIS)

Purpose: Dose distributions are calculated for various models of 125I and 103Pd seeds in the standardized plaques of the Collaborative Ocular Melanoma Study (COMS). The sensitivity to seed model of dose distributions and dose distributions relative to TG-43 are investigated. Methods: Monte Carlo simulations are carried out with the EGSnrc user-code BrachyDose. Brachytherapy seeds and eye plaques are fully modeled. Simulations of one seed in the central slot of a 20 mm Modulay (gold alloy) plaque backing with and without the Silastic (silicone polymer) insert and of a 16 mm fully loaded Modulay/Silastic plaque are performed. Dose distributions are compared to those calculated under TG-43 assumptions, i.e., ignoring the effects of the plaque backing and insert and interseed attenuation. Three-dimensional dose distributions for different 125I and 103Pd seed models are compared via depth-dose curves, isodose contours, and tabulation of doses at points of interest in the eye. Results are compared to those of our recent BrachyDose study for COMS plaques containing model 6711 (125I) or 200 (103Pd) seeds [R. M. Thomson et al., Med. Phys. 35, 5530-5543 (2008)]. Results: Along the central axis of a plaque containing one seed, variations of less than 1% are seen in the effect of the Modulay backing alone for different seed models; for the Modulay/Silastic combination, variations are 2%. For a 16 mm plaque fully loaded with 125I (103Pd) seeds, dose decreases relative to TG-43 doses are 11%-12% (19%-20%) and 14%-15% (20%) at distances of 0.5 and 1 cm from the inner sclera along the plaque's central axis, respectively. For the same prescription dose, doses at points of interest vary by up to 8% with seed model. Doses to critical normal structures are lower for all 103Pd seed models than for 125I with the possible exception of the sclera adjacent to the plaque; scleral doses vary with seed model and are not always higher for 103Pd than for 125I. Conclusions: Dose decreases relative to doses calculated under TG-43 assumptions vary slightly with seed model (for each radionuclide). Dose distributions are sensitive to seed model; however, variations are generally no larger than the magnitudes of other systematic uncertainties in eye plaque therapy.

336

Synthesis and binding characteristics of N-(1-naphthyl)-N'-(3-[{sup 125}I]-iodophenyl)-N'-methylguanidine ([{sup 125}I]-CNS 1261): a potential SPECT agent for imaging NMDA receptor activation  

Energy Technology Data Exchange (ETDEWEB)

N-(1-Naphthyl)-N'-(3-[{sup 125}I]-iodophenyl)-N'-methylguanidine ([{sup 125}I]-CNS 1261) was synthesized as a potential radioligand to image N-methyl-D-aspartate (NMDA) receptor activation. [{sup 125}I]-CNS 1261 was prepared by radioiodination of N-(1-naphthyl)-N'-(3-tributylstannylphenyl)-N'-methylguanidine using Na{sup 125}I and peracetic acid. [{sup 125}I]-CNS 1261 uptake in vivo reflected NMDA receptor distribution in normal rat brain, whereas in ischemic rat brain, uptake was markedly increased in areas of NMDA receptor activation. Radiolabeled CNS 1261 appears to be a good candidate for further development as a single photon emission computed tomography tracer in the investigation of NMDA receptor activation in cerebral ischemia.

Owens, Jonathan E-mail: j.owens@clinmed.gla.ac.uk; Tebbutt, Andrew A.; McGregor, Ailsa L.; Kodama, K.; Magar, Sharad S.; Perlman, Michael E.; Robins, David J.; Durant, Graham J.; McCulloch, James

2000-06-01

337

Photolabeling and radioligand binding of human erythrocyte NaK-ATPase with 125I-derivatives of cymarin and digitoxigenin  

International Nuclear Information System (INIS)

NaK-ATPase is an enzyme which maintains Na+ and K+ gradients across the plasma membrane of eukaryotic cells, and is specifically inhibited by cardiac glycosides. The cardiac glycoside binding site is located primarily on the catalytic ? subunit but the glycoprotein ? and proteolipid-? subunits may also contribute to the structure of the site. In order to label the cardiac glycoside binding site of human erythrocytes, four photoaffinity ligands with very high specific radioactivity were synthesized. The compounds, which are abbreviated [125I]AISC, [125I]AIPP-GluD, [125I]AIPP-GalD and [125I]IA-GalD, were all effective photolabels for NaK-ATPase as shown by ouabain-protectable, covalent labeling of the ?, ?, and proteolipid-? subunits. In order to study the possible existence of a very high affinity binding site in erythrocyte NaK-ATPase, a carrier-free radioligand, [125I]I-TASC, was synthesized; this compound had the same structure as [125I]AISC except that a light-sensitive azide group was replaced with a hydroxyl group. Competitive binding assays with cymarin against 0.2 nM [125I]I-TASC suggested two classes of erythrocyte binding sites. Scatchard analysis of direct [125I]I-TASC binding indicated that the very high affinity, low capacity class of erythrocyte bindings sites had a KD of 54 pM and a Bmax of 23 fmol/mg proteinsub> of 23 fmol/mg protein

338

Measurement of hepatic blood flow in the unanesthetized rabbit using 198Au and 125I rose bengal clearance technique  

International Nuclear Information System (INIS)

Hepatic blood flow was measured in the unanesthetized rabbit using the clearance technique of 198Au and 125I RB. The values are: 71.82+-16.24ml.min-1.kg-1 for 198Au, and 60.21+-9.94ml.min-1.kg-1 for 125I RB (P198Au

339

Retrograde axonal transport of 125I-nerve growth factor in rat ileal mesenteric nerves. Effect of streptozocin diabetes  

International Nuclear Information System (INIS)

NGF in the ileal mesenteric nerves of animals that had been diabetic for 11-13 mo demonstrated decreased amounts of 125I-NGF in transit in unligated paravascular nerve fascicles. There was, however, no evidence for focal retardation of transported 125I-NGF at the sites of dystrophic axonal lesions

340

Behaviour of homologous 125I fibrinogen after thrombin and ancrod infusion in rabbits  

International Nuclear Information System (INIS)

The behaviour of radioactively labelled fibrinogen after infusion of thrombin or ancrod is investigated. Common factors and differences in the behaviour of fibrinogen after infusion of these two enzymes, which act proteolytically on the fibrinogen, are dealt with. Rabbits received an i.v. injection of homologous 125I-fibrinogen 3 days before ancrod or thrombin infusion. On the day of the experiments, one group of animals received an ancrod infusion (1.5 U/kg body weight for 30 minutes), the other a thrombin infusion (600 U/kg body weight for 60 minutes). Intravenous ancrod and thrombin infusions lowered the fibrinogen level to 30% or 50% of the initial value due to intravascular coagulation. About 50% of the 125I fibrinogen was transformed after ancrod exposure into a non-coagulating fraction of fibrinogen derivatives which produces no fibrinolytic decomposition products. (orig./AJ)

 
 
 
 
341

Tissue localization of [125I]triiodothyronine in the periorbital area of mice: a microautoradiographic study  

International Nuclear Information System (INIS)

A significant retention of [125I]triiodothyronine ([125I]T3] in the retrobulbar orbital area of mice has been previously shown. The present study was initiated to determine tissue and intracellular localization of the thyroid hormone in the above area which is concerned in human Graves' disease of the thyroid. In conclusion, after in vivo injection, the thyroid hormone rapidly penetrates the cells of fat glandular and muscular tissues in the orbital area. Intracellularly, the affinity of the hormone for the secretory vesicles, rough endoplasmic reticulum, mitochondria and nucleus suggest that T3 could play a role in secretory and metabolic functions of the tissues in the retrobulbar orbital area. (Author)

342

Human growth hormone radioiodination using different batches of 125I of various ages  

International Nuclear Information System (INIS)

The reproducibility and the influence of the batch and decay level of Na125I on the radioiodination of human growth hormone (hGH) were examined by a polyacrylamide gel electrophoresis (PAGE) technique. The between-day coefficient of variation (CV) exhibited a value of 11.9% for labelling yields and 14.3% for antibody specific binding. The within-day variation for different shipments and isotope decay-levels was similar to that for the control experiment, carried out under the same conditions, using Na125I from a single lot. The results indicate that the decay-level and batch do not significantly influence either the yields or the immunological properties of the labelled product. The suitability of this PAGE technique as a control test for radioiodinated proteins is established by comparison with gel chromatography on Sephadex G-100. (Auth.)

343

Clinical application of esophageal stent loaded with 125I seeds: recent progress in research  

International Nuclear Information System (INIS)

Esophageal cancer is a common malignant tumor. Most patients have already in the late stage of the disease when the diagnosis is confirmed and have lost the surgery chance. In recent years, esophageal stent has been widely applied in the treatment of esophageal stenosis caused by esophageal cancer. The clinical experience shows that the esophageal stent can effectively solve the problem of dysphagia. However, the ordinary esophageal stent has no therapeutic effect on the esophagus tumor. The esophageal stent loaded with 125I seeds can not only solve the dysphagia problem but also can treat the primary esophagus cancer with its brachytherapy effect. This article aims to review the clinical application and the up-to-date research progress of the esophageal stent loaded with 125I seeds. (authors)

344

Monte-Carlo simulation of uncertainty in the estimation of 125I in the thyroid  

International Nuclear Information System (INIS)

23 to 1.06 x 10-2 counts per photon for detector distance of 3-12 cm and from 7.53 to 3.66 x 10-2 counts per photon for OTT varying from 0.6 to 2.0 cm keeping the detector at a distance of 3 cm. This study shows that the variations in OTT constitute a major source of uncertainty. The computed uncertainties due to various parameters should be taken into account while estimating the thyroidal burden of 125I in the radiation workers. The feasibility of using coincidence method for absolute determination of the 125I activity in the thyroid is also discussed in this paper. (authors)

345

125I-radioimmunotherapy with carbohydrate-based linkers coupling radioiodinated molecules to IgG  

International Nuclear Information System (INIS)

Electrophilically radioiodinated IgG's for in vivo radioimmunotherapy are fraught with difficulties; enzymatic dehalogenation, failure to deliver enough radionuclide to effectively destroy the cell, release of radionuclide from the cytoplasm before an effective disintegration can occur and binding avidity loss by the IgG for its target antigen. Many of these problems are solved by avoiding direct radioiodination of the IgG. The authors studies use carbohydrate moieties, including dextran derivatives and cellobiose, as linker/spacers to increase the amount of 125I-labelled species (tyramine or pyrimidines) a single IgG can deliver. The approach appears to increase residence time of the radionuclide within the cell. Syntheses, labeling, assembly, uptake and release rates for 125I-immunoconjugates of MAb 425 (targeted to human glioma tumor cells) are discussed

346

Genetic effects of 131I and 125I in mouse male germ cells  

International Nuclear Information System (INIS)

A study was made of the genetic effects of iodine radioactive isotopes in male germ cells of (CBAxC57B1)F1 hybrid mice. After a single intraperitoneal administration of Na131I(1.48 to 740 kBq/g) or Na125I (148 to 7400 kBq/g) to males the occurrence of dominant lethal mutations (DLM), reciprocal translocations (RT), and abnormal sperm heads (ASH) was studied. The radioactie iodine isotopes induced DLM at the postmeiotic spermatogenesis stages only. After the effect of the isotopes, the frequency of RT increased insgnificantly with dose. The frequency of ASH was only increased with the highest 131I dose. Relative biological effectiveness of 131I and 125I was less than 1 with a reference to the indices under study

347

Myocardial fatty acid metabolism in diabetic mice with 125I-BMIPP  

International Nuclear Information System (INIS)

In patients with diabetes mellitus, the existence of diabetic cardiomyopathy was substantiated. This study was undertaken to evaluate the myocardiac fatty acid metabolism of diabetic mice (n=21) and controls (n=21) in 125I-BMIPP in fasted and unfasted states. 125I-BMIPP of 370 kBq was given and thirty minutes later, animals from both groups were killed. Samples of hearts, liver and other organs were removed, weighed and then counted in a scintillation counter. The percent injected dose/g of hearts of diabetic mice was significantly reduced compared to controls in unfasted (p<0.05) and fasted (p<0.01) groups. These findings may reflect impaired fatty acid utilization of the hearts in diabetic mice compared to controls. (author)

348

Synthesis and biological evaluation of 125I-erythropoietin as a potential radiopharmaceutical agent for tumours  

International Nuclear Information System (INIS)

Erythropoietin (EPO) is a glycoprotein hormone responsible for regulating erythropoiesis. Expression of EPO and EPO receptors (EPOr) has recently been demonstrated in some neoplastic cell lines and tumours, suggesting a potential new target for therapy. In this work, EPO was labeled with iodine-125 using the lactoperoxidase method, known to prevent damage to protein during radioiodination, and labeling conditions were optimized. In vitro stability studies have shown that 125I-EPO is radiochemically stable for 20 days after radiolabeling. In vitro cell binding studies have demonstrated very low binding (125I-EPO. In mice with induced melanoma, only a residual fixation in the tumour was evident. Further studies are warranted on other tumoral cell lines to better understand the binding process and internalization into cells. Studies on EPO labeled with carbon-11 could be valuable, since there is a greater chance of preserving the biological activity of the protein using this method. (author)

349

Immobilization of viral antigens on filter paper for a [125I] staphylococcal protein A immunoassay  

International Nuclear Information System (INIS)

A new technique is described for the rapid detection and quantitation of herpes simplex virus (HSV) antigens and antiviral antibodies. It involves immobilization of HSV antigens on filter paper discs and subsequent analysis by 125I-labelled staphylococcal protein A (SPA) radioimmunoassay. A specially designed 96-well filtration device is employed which serves both as an incubation chamber and as a filtration manifold. It is rapid, simple, sensitive and specific, and requires only small volumes of antiserum and few target cells. The results may be readily and objectively quantitated. This technique permits the simultaneous assay of a large number of specimens in less than 1h. Its sensitivity is considerably greater than that of other currently used immunologic techniques, and it is amenable to automation. These characteristics suggest that this [125 I]SPA immunofiltration technique may be applicable to the rapid diagnosis of viral infections. (Auth.)

350

Quantitative determination of islet cell surface antibodies using 125I-protein A  

International Nuclear Information System (INIS)

A quantitative method to measure islet cell surface antibodies in human patients has been developed using 125I-protein A. Isolated, dispersed, viable rat islet cells prepared by collagenase digestion were fixed in 4% paraformaldehyde to allow storage for up to 7 wk at 4 degrees C. Human sera, heat inactivated and adsorbed with rat liver and kidney powder (100 mg/ml), were incubated with the fixed cells (50 x 10(3)) for 60 min at 37 degrees C. Thereafter the cells were washed and exposed to 5 x 10(5) cpm 125I-protein A, which binds to IgG attached to the cell surface. Assay precision (14%) and reproducibility (16%) were established by repeated analysis of pooled sera from healthy individuals and IDDM patients using pooled batches of islet cells. Using this method, islet cell surface antibodies were detected in 35% of insulin-dependent diabetic patients

351

Radiohalodestannylation: synthesis of 125I-labeled 17?-E-iodovinylestradiol  

International Nuclear Information System (INIS)

17?-E-Iodovinylestradiol and its iodine-125-labeled analog were prepared by halodestannylation. The synthesis of the unlabeled compound was achieved from estrone in two steps with an overall yield of 30%. The tributylstannylvinylestradiol intermediate reacted with sodium [125I]iodide (specific activity = 2200 Ci/mmol) in the presence of hydrogen peroxide and acetic acid to give the 17?-E-[125I]iodovinylestradiol in 40-60% yield after isolation by reversed phase column chromatography. The radiochemical purity was greater than 98% and no other u.v. active components could be detected by HPLC. The ease of preparation and isolation of this radioligand suggests that radiohalodestannylation may be the method of choice for this and structurally similar compounds. (author)

352

Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources  

International Nuclear Information System (INIS)

An exhaustive revision of dosimetry data of 192Ir, 125I, 103Pd, and 169Yb brachytherapy sources has been performed by mean of the EGS4 Simulation System. DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were included in the calculations. Absorbed dose rate per unit contained activity in medium at 1 cm in water and air-kerma strength per contained activity for each seed model were calculated, allowing specific dose rate constant (DRC) Ao to be estimated. The influence of calibration procedure on source strength for low energy seeds is discussed. A theoretical estimate of the DRC for 103Pd model 200 seed equal to 0.669 +- 0.002 is achieved. Comparison of the obtained DRC with measured and calculated publish results agreement within 1.5% for 192Ir, 169Yb and 125I sources

353

Preparation of 125I-Ochratoxin and its biodistribution in rats  

International Nuclear Information System (INIS)

Ochratoxin was successfully labelled with 125I in presence of chloramine-T (Ch-T) as an oxidizing agent. The effects of different reaction parameters such as reaction time, oxidizing agent concentration, ph and concentration of ochratoxin have been investigated. Separation and identification of the labelled products were achieved by means of thin layer chromatography (TLC) and gel chromatography using sephadex G-25 column. The labelled product was orally administrated to rats and the accumulation of radioactivity in the body at definite time intervals was examined. The accumulation of the radioactivity was pronounced at the kidney, the liver, the blood and digestive intestinal tract. The produced 125I-ochratoxin was found stable in-vivo against biological decomposition

354

Study on permeability of ?-NGF through blood brain barrier by 125I tracing  

International Nuclear Information System (INIS)

?-NGF is extracted from fetus brain by centrifugation, dialysing and ion-exchange chromatography. The molecular weight of ?-NGF is 13 kD detected by SDS-PAGE electrophoresis; the isoelectric point of ?-NGF are 9.0, 9.2 and 9.3 respectively detected by isoelectric focusing electrophoresis; the ?-NGF shows the effect of stimulating neurite growth by PC12 cells culture. Using the 125I tracing technique, the animal experiments indicate (2.41 +- 0.12)% of injected 125I-?-NGF could go through the blood brain barrier at 15 min, and increase to (4.20 +- 0.07)% at 30 min. The results provides scientific basis for research of ?-NGF in clinical therapeutic application

355

Preparation of [123I]- and [125I]epidepride: a dopamine D-2 receptor antagonist radioligand  

International Nuclear Information System (INIS)

(S)-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[123I] iodo-2,3-dimethoxybenzamide (TDP 517) (proposed generic name, [123I]epidepride) is the iodine-123 substituted analogue of isoremoxipride (FLB 457), both of which are very potent dopamine D-2 antagonists (epidepride KD 0.024 nM). [123I] Epidepride was radioiodinated in 60-70% radiochemical yields in 35 min from the corresponding 5-(tributyltin) derivative using Na123I with a specific radioactivity of 3000 Ci/mmol, and oxidized in situ with chloramine-T. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. Alternatively, using no carrier-added Na125I as the radioisotope, [125I] epidepride at 2000 Ci/mmol specific radioactivity was prepared in 86% radiochemical yield and 99% radiochemical purity after purification by reverse phase HPLC in ethanolic phosphate buffer. (author)

356

Specific binding of 125I-labeled human follicle stimulating hormone to testicular slice  

International Nuclear Information System (INIS)

A simple radioreceptor-assay technique for human follicle stimulating hormone (hFSH) with use of rat testicular slice and enzymatically 125I-labeled hFSH was described. It was shown that 125K-hFSH bound to the testicular slice (30 mg) was approximately 2% of the total amount added to the tube (2 ng/tube), half of which was displaceable in the presence of 1 ?g/tube of unlabeled hFSH. Although only small amount of 125I-hFSH was bound specifically to the tissue, the binding was not inhibited by other peptide hormones tested. The testicular receptor for hFSH had high affinity constant (2.5x109 M-1) and hormonal specificity, suggesting a possibility of the physiological application of this radioreceptor assay for the measurement of hFSH in body fluids. (author)

357

125I-iomazenil - benzodiazepine receptor binding and serum corticosterone level during psychological stress in a rat model  

International Nuclear Information System (INIS)

To test the hypothesis that benzodiazepine receptor density decreases in response to stress, we correlated 125I-iomazenil (125I-IMZ) binding with serum corticosterone levels in a rat model. Wistar male rats were divided into four groups; control group (CON, 10 rats), no physical or psychological stress; and one-, three-, and five-day stress groups of 12 rats each (1-DAY, 3-DAY, and 5-DAY, respectively), receiving psychological stress for the given number of days. Psychological stress were given to rats with a communication box. The standardized uptake value (SUV) of 125I-iomazenil of the 3-DAY and 5-DAY showed that 125I-iomazenil - benzodiazepine receptor binding was significantly reduced in the cortices, accumbens nuclei, amygdala and caudate putamen (p125I-IMZ is a useful radioligand to reflect received stress and its binding in the cortices, accumbens nuclei, amygdala and caudate putamen is strongly affected by psychological stress

358

Comparison of the accumulation of 125I and 144Ce in the growing oocytes of the Japanese quail  

International Nuclear Information System (INIS)

Japanese quail were doubly-labeled with 125I (carrier free, as sodium iodide) and 144Ce (.015 micromol/100 g, as trichloride). by 1 hr after administration, the growing oocytes and the ova had accumulated 29% of the 125I and 21% of the 144Ce. By 18 hr, the accumulations were 30% of the 125I and 79% of the 144Ce. Lanthanum (15 micromol/100 g, as trichloride), given iv 5 min before the radionuclides, resulted in 1-hr accumulations of 4% for 125I and 23% for 144Ce. On fractionation of the oocyte yolk, 86% of the 125I present in the yolk was found in the low density fraction and 69% of the 144Ce remained with the phosvitin fraction. These results were consistent with the suggestion of Schjeide and Prahlad (1977) that, in plasma, iodide becomes associated with the calcium-containing vitellogenin complex

359

Effect of body size on accumulation and distribution of 125I in the green mussel (Perna Viridis)  

International Nuclear Information System (INIS)

Effect of body size on accumulation and distribution of 125I in the green mussel (Perna Viridis), has been studied. The results showed that concentration capacity of every part in smaller mussels was higher than that in larger ones. Concentration factors of 125I in byssus (about 0.5 x 103?1.5 x 103), the highest in all parts of the mussels, were 30?200 times as that in soft tissues, 200?600 times as that in feet, 600?1000 times as that in shells. Although wet weight of byssus was no more than 1% of whole body's wet weight, the content of 125I accumulated in it accounted for as high as 75% of total 125I content. The relationship between concentration factor of 125I in byssus and whole body's wet weight (or shell length) can be described as a negative power function. (16 refs., 2 figs., 3 tabs.)

360

Effects of hypothyroidism on vascular /sup 125/I-albumin permeation and blood flow in rats  

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Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease.

Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

1989-05-01

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