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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

Evaluation of prostate coverage and calculation of TCP in permanent prostatic implants with 125I rapid strands  

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Localized prostate cancer can be treated by a permanent implant with 125I seeds. A major advantage of a permanent implant is the small planning target volume, which has to be significantly larger in external beam irradiation to accommodate for the less steep dose gradient, uncertainties in patient set up and for prostate movement. The aim of this work is to evaluate prostate coverage in permanent implants with 125I RAPID strands and to compare tumor control probability (TCP) achievable by external beam radiotherapy and by permanent implants

3

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

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

4

Prostatic edema in 125I permanent prostate implants: Dynamical dosimetry taking volume changes into account  

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The purpose of this study is to determine the impact of edema on the dose delivered to the target volume. An evaluation of the edema characteristics was first made, and then a dynamical dosimetry algorithm was developed and used to compare its results to a standard clinical (static) dosimetry. Source positions and prostate contours extracted from 66 clinical cases on images taken at different points in time (planning, implant day, post-implant evaluation) were used, via the mean interseed distance, to characterize edema [initial increase (?r0), half-life (?)]. An algorithm was developed to take into account the edema by summing a time series of dose-volume histograms (DVHs) with a weight based on the fraction of the dose delivered during the time interval considered. The algorithm was then used to evaluate the impact of edema on the dosimetry of permanent implants by comparing its results to those of a standard clinical dosimetry. The volumetric study yielded results as follows: the initial prostate volume increase was found to be 1.58 (ranging from 1.15 to 2.48) and the edema half-life, approximately 30 days (range: 3 to 170 days). The dosimetric differences in D90 observed between the dynamic dosimetry and the clinical one for a single case were up to 15 Gy and depended on the edema half-life and the initial volume increase. The average edema half-life, 30 days, is about 3 times longer than the previously reported 9 days. Dosimetric differencly reported 9 days. Dosimetric differences up to 10% of the prescription dose are observed, which can lead to differences in the quality assertion of an implant. The study of individual patient edema resorption with time might be necessary to extract meaningful clinical correlation or biological parameters in permanent implants

5

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

6

Implantation with 125I seeds for the treatment of tumor  

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The 125I with special biological and physical characters is available to interstitial brachytherapy. The 125I seeds implantation is widely used in treating malignant tumor abroad. Implantation with 125I seeds is an important and effective method in the treatment of prostate cancer, but it is performed as pilot study in the treatment of other tumors

7

Dosimetric consideration of individual 125I source strength measurement and a large-scale comparison of that measured with a nominal value in permanent prostate implant brachytherapy  

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We investigated the difference between measured and manufacturer's nominal source strength in a large sample of a single model of 125I seeds. Physical characteristics of single seed measurement by the well-type ionization chamber were also investigated to provide dosimetric data. A well-type ionization chamber with a single seed holder was used to measure source strength of all 1935 125I seeds implanted in the initial 28 patients in our hospital. Physical characteristics including linearity of readings for different integral time intervals, reproducibility, isotropy, and axial positional sensitivity were assessed. To calculate the source strength, the integral charge during 30s was measured and converted to air kerma strength. The nominal activity stated by the manufacturer was compared with the measured value. Linearity, reproducibility, and isotropy of the well-type ionization chamber were within 0.2%. Measured source strength was on average 2.1% (range -7.6% to +7.2%), lower than the nominal value. Standard deviation of all measured seeds was 2.0%. The maximum difference between the measured and the manufacturer's nominal source strength in each patient was -3.7%. The standard deviation averaged 1.6%. The nominal source strength of the 125I seeds agreed well with the measured value. Our study can be helpful as guidance for individual 125I seed source strength measurement. (author)

8

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

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Purpose: The dosimetric merit of a permanent prostate implant relies on two factors: the quality of the plan itself, and the fidelity of its implementation. The former factor depends on source type and on source strength, while the latter is a combination of skill and experience. The purpose of this study is to offer criteria by which to select a source type (125I or 103Pd) and activity. Methods and Materials: Given a prescription dose and potential seed positions along needles, treatment plans were designed for a number of seed types and activities, specifically for 125I with activities ranging from 0.3 to 0.7 mCi, and for 103Pd with activities in the range of 0.8 to 1.6 mCi. To avoid human planner bias, an automated computerized planning system based on integer programming was used to obtain optimal seed configurations for each seed type and activity. To simulate the effect of seed-placement inaccuracies, random seed-displacement 'errors' were generated for all plans. The displacement errors were assumed to be uniformly distributed within a cube with side equal to 2no. sigmano. The resulting treatment plans were assessed using two volumetric and two dosimetric indices. Results: For 125I implants a coverage index (CI) of 98.5% or higher can be achieved for all activities (CI is the fraction of the target volume receiving the prescribed or larger dose). The external volume index (EI) (i.e., the amount of healthy t index (EI) (i.e., the amount of healthy tissue, as percentage of the target volume, receiving the prescribed or larger dose) increases from 13.9% to 20% as the activity increases from 0.3 to 0.7 mCi. For implants using 103Pd, the external volume index increases from 10.2% to 13.9% whenever CI exceeds 98.5%. Volumetric and dosimetric indices (coverage index, external volume index, D90, and D80) are all sensitive to seed displacement, although the activity dependence of these indices is more pronounced for 125I than for 103Pd implants. Conclusions: For both isotopes, the lower activities studied systematically result in lower EIs. If seeds can be placed within approximately 0.5 cm of their intended position 103Pd should be preferred because its EI is lower than that of 125I. For all activities the coverage indices and D90 are within the required range. If seed placement uncertainties are larger than 0.5 cm, 125I provides slightly better target coverage; however, in terms of external volume (healthy tissue) covered, 103Pd is superior to 125I

9

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

10

Angular and radial dependence of the energy response factor for LiF-TLD micro-rods in 125I permanent implant source  

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EGSnrc Monte Carlo simulations were used to calculate the angular and radial dependence of the energy response factor for LiF-thermoluminescence dosemeters (TLDs) irradiated with a commercially available 125I permanent brachytherapy source. The LiF-TLDs were modelled as cylindrical micro-rods of length 6 mm and with diameters of 1 mm and 5 mm. The results show that for a LiF-TLD micro-rod of 1 mm diameter, the energy response relative to 60Co gamma rays is 1.406 ± 0.3% for a polar angle of 90 deg. and radial distance of 1.0 cm. When the diameter of the micro-rod is increased from 1 to 5 mm, the energy response decreases to 1.32 ± 0.3% at the same point. The variation with position of the energy response factor is not >5% in a 6 cm x 6 cm x 6 cm calculation grid for the 5 mm diameter micro-rod. The results show that there is a change in the photon spectrum with angle and radial distance, which causes the variation of the energy response. (authors)

11

The clinical application of 125I radionuclide implantation in tumor therapy  

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

12

125I seed fixity after implantation in parotid region  

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Objective: To observe the fixity of 125I seed after implantation in parotid region. Methods: Ten patients treated with 125I seed interstitial brachytherapy in parotid were randomly selected. Within one week after the treatment, two plane radiographs were taken by radiotherapy simulator and 125I seed was counted. All plane dosimetry analysis were performed by treatment planning system. The areas surrounded by 50%, 100% and 150% of prescription dose curve and dose equality index were calculated. Two months after the treatment, the same examination were repeated and were compared with t test. Results: The number of seeds was equal in two examination. There were no significant differences in two examinations either for the areas surrounded by 50%, 100% and 150% of prescription dose curve or for the dose equality index. Conclusions: The position of 125I seed after implantation in parotid region is quite fixable, which can ensure the curative effect. (authors)

13

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

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Objective: To compare the dosimetric differences of permanent prostate brachytherapy utilizing 131Cs, 125I and 103Pd seeds. Methods: Twenty-five patients with T1-T2c prostate cancer who had previously implanted with 125I seeds were randomly selected in our study. The patients were re-planned with 131Cs, 125I and 103Pd seeds by using the Prowess Brachytherapy 3.1 planning system to the prescription doses of 115 Gy, 145 Gy and 125 Gy, respectively. The seed strengths were 1.8 U,0.5 U and 1.8 U, respectively. The prostate, prostatic urethra and anterior wall of the rectum were contoured on trans-rectal ultrasound images. PTV was outlined based on the prostate volume with no margin applied. The attempted planning goals were that V100 (the percentage volume of the prostate receiving at least 100% of the prescription doses)= 95%, D90 (the minimum percentage dose covering 90% of the prostate volume) ?100%, and prostatic urethra UD10 (the maximum percentage dose receiving by 10% of the contoured urethra) ?150%. For the plan comparison, we also computed prostate V150, prostatic urethra UV120, rectum RV100, and the number of implanted seeds and needles. The significance of the differences was tested using one way analysis of variance. Results: The average V200 in the 103Pd, 125I the 103Pd, 125I and 131Cs plans were 28.7%, 20.9% and 19.6% (F=42.50, P=0.000); the average V150 were 51.9%, 42.1% and 39.4% (F=26.15, P=0.000); the average UV120 were 26.9%, 29.5% and 23.8% (F=0.37, P=0.691); and the average rectum RV100 were 0.31 cm3, 0.22 cm3 and 0.19 cm3 (F=0.43, P=0.652). For 103Pd, 125I and 131Cs, the average number of implanted seeds per cm3 prostate were 2.02, 2.01 and 1.87 (F=1.92, P=0.154), and the average number of needles were 33.6, 32.9 and 31.6 (F=0.26,P=0.772). Conclusions: Comparing to 125I and 103Pd seeds used in permanent prostate brachytherapy, 131Cs seeds has better dose homogeneity, and possible better sparing of the urethra and rectum, with comparable or less implanted seeds and needles. (authors)

14

CT-based dosimetry calculations for 125I prostate implants  

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Purpose: To evaluate the Monte Carlo code MCNP4B for low-energy brachytherapy calculations, including the effects of interseed attenuation and patient specific heterogeneities, on the calculated dose distribution from transperineal implantation of 125I. Methods and Materials: The Monte Carlo code MCNP4B was used to model and benchmark the absolute dose distribution from two 125I brachytherapy seeds (model 6711 and 6702). Based upon the physical source model, the total photon intensity and differential energy spectrum were evaluated as a function of angle from the transverse bisector of the source. These spectral and intensity data were reformatted to produce probability distributions for sampling from a virtual point source. The virtual source model and a modified version of MCNP4B is then used for simulating arbitrary brachytherapy source configurations within a homogeneous or heterogeneous patient specific computed tomography (CT)-based lattice geometry. Results and Conclusion: Comparison with TG-43 data and the Monte Carlo calculations is excellent with MCNP4B predicting the radial dose function for the 125I 6711 and 6702 sources within 6% for all data points tested. Attenuation effects from neighboring seeds were investigated for pre- and postimplant seed distributions and found to be negligible. Preliminary dosimetry analysis of postimplant seed distributions comparing homogeneous water versus heterogeneous CT simulation geometriersus heterogeneous CT simulation geometries indicates an average decrease of approximately 5.6% for the volume of tissue irradiated to a prescription isodose line of 144 Gy

15

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

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

16

Clinical application of transperineal 125I-seed implantation guided by ultrasonography in prostate cancer  

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Objective: To establish an optimal technological protocol, and to observe the short-term efficacy and morbidity of transperineal 125I-seed implantation guided by transrectal ultrasonography in prostate cancer. Method: Thirty-two patients were treated with transperineal 125I-seed brachytherapy guided by transrectal ultrasound. Among them 6 patients were treated with the seed implantation plus preor post-external beam radiotherapy (EBRT). Biochemical failure was defined as consecutive elevations of PSA level for three times during follow-up period and the biochemical progression-free was defined as biochemical control. Results: The pre- and post-implantation median serum PSA values of 14 patients were (52.14 ± 54.61) ng/ml and (4.26 ± 7.11) ng/ml, respectively (t=3.253, P=0.003). The biochemical control rate was 100%. The pre- and post-treatment median PSA values of 12 recurrent prostate cancer patients were (15.14 ± 20.80) ng/ml and (18.94 ± 35.25) ng/ml, respectively (t=-0.307, P=0.764). Their biochemical control rate was 75%. The pre- and post-implantation median PSA values of 5 patients with bone metastases were (120.03 ± 145.96) ng/ml and (75.53 ± 84.84) ng/ml, respectively (t=0.527, P=0.621). In 34.62% patients treated only with 125I-seed implication urinary complications were not experience and the incidences of Grade I, II, III, IV and V urinary side effects were 38.46%, 11.54%, 11.54%, 0 and 3.85%, respectively. The incide and 3.85%, respectively. The incidences of Grade I, II, III and IV urinary morbidity were 16.67%, 0, 0 and 16.67%, respectively for patients treated with seed implantation plus EBRT. Grade 1 rectal toxicity was noted in 3.12% patients. In 3.12% patients, one seed migration occurred. Conclusion: Transperineal permanent brachytherapy is safe, convenient, minimally invasive, with low urinary and rectal side effects. (authors)

17

125I Vicryl suture implants as a surgical adjuvant in cancer of the head and neck  

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Sixty-four intraoperative 125I seed implants using absorbable suture (Vicryl) carriers were performed in 53 patients with head and neck cancers at Stanford between 1975 and 1980. In previously untreated patients, local control in the implanted volume or in all head and neck sites was obtained in 79 and 71%, respectively. Of 34 patients with recurrent carcinomas, local control was obtained in the implant volume in 20 (59%), while 38% had no recurrence post-implantation in any head and neck site. The incidence of complications is correlated with 125I radiation doses, total millicuries inserted, seed strength used, and tissue volume implanted for both untreated patients and those with local recurrences. Guidelines for the optimal use of the above 4 parameters are also presented. The authors conclude that 125I seed Vicryl intraoperative suture implants are an effective surgical adjuvant in the treatment of advanced, previously untreated or recurrent head and neck cancers

18

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

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

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

2013-10-01

19

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

Science.gov (United States)

Postimplant dosimetry (PID) after Iodine-125 ((125)I) implant of the prostate should offer a reliable qualitative assessment. So far, there is no consensus regarding the optimum PID method, though the latest literature is in favor of magnetic resonance imaging (MRI). This study aims to simultaneously compare 3 PID techniques: (1) MRI-computed tomography (CT) fusion; (2) ultrasound (US)-CT fusion; and (3) manual target delineation on CT. The study comprised 10 patients with prostate cancer. CT/MR scans with urinary catheters in place for PID were done either on day 0 or day 1 postimplantation. The main parameter evaluated and compared among methods was target D90. The results show that CT-based D90s are lower than US-CT D90s (median difference,-6.85%), whereas MR-CT PID gives higher D90 than US-CT PID (median difference, 4.25%). Manual contouring on CT images tends to overestimate the prostate volume compared with transrectal ultrasound (TRUS) (median difference, 23.33%), whereas on US images the target is overestimated compared with MR-based contouring (median difference, 13.25%). Although there are certain differences among the results given by various PID techniques, the differences are statistically insignificant for this small group of patients. Any dosimetric comparison between 2 PID techniques should also account for the limitations of each technique, to allow for an accurate quantification of data. Given that PID after permanent radioactive seed implant is mandatory for quality assurance, any imaging method-based PID (MR-CT, US-CT, and CT) available in a radiotherapy department can be indicative of the quality of the procedure. PMID:23611630

Marcu, Loredana G; Gowda, Raghu

2013-01-01

20

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

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

 
 
 
 
21

Brachytherapy with permanent seed implantation  

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Permanent interstitial brachytherapy with iodine-125 (I-125) or palladium 103 (Pd-103) seeds is a common treatment option in the United States, and numerous articles on outcomes after long-term follow up have been published. With the treatment's apparent high efficacy and low morbidity, permanent seed implantation has become the most frequently employed procedure for localized prostate cancer and has replaced radical prostatectomy. Even taking into account the good features of the treatment, the performance of permanent seed implantation in Japan had not been allowed because of the country's strict laws on radiation safety. However, after a long period of discussion between Japanese medical associations and the government, permanent interstitial brachytherapy with I-125 was finally approved in Japan in July 2003. The guidelines for this treatment include several restrictions that should be followed by each institution that is to perform the treatment. Over 70 institutes around the country had started the treatment before the end of June 2007. With high expectations for this new radiation therapy, which may be effective, and less invasive than previous treatments and with a low incidence of treatment morbidity, brachytherapy for prostate cancer will become more common in Japan. For the purpose of improving the quality of seed implantation, which may lead to better clinical outcomes and radiation safety, medical conferences and technical training courses have been carritechnical training courses have been carried out regularly, and multi-institutional clinical studies have also been carried out countrywide. (author)

22

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

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

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

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

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

25

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

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

Mazeron Renaud

2012-03-01

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

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

27

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

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

28

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

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

29

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

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

Yang Zuozhang

2012-03-01

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Surgery and permanent 125I seed paraspinal brachytherapy for malignant tumors with spinal cord compression  

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Purpose: To evaluate the functional outcome, predictors of response, and toxicity from spinal surgery and 125I brachytherapy in patients with malignant tumors resulting in spinal cord compression. Methods and Materials: Between July 1985 and September 2001, after surgical resection, 30 patients underwent 31 intraoperative paraspinal brachytherapy procedures at Barrow Neurological Institute. Twenty-four (with 25 procedures) had follow-up at our clinic and form the basis for this report. Surgical procedures were based on the location of the impinging lesion: corpectomy or spondylectomy in 13 cases and laminectomy in 12. Permanent 125I seeds in absorbable suture were placed with open exposure after resection. Results: Spinal cord compression was cervical in 4 (16%), thoracic in 14 (56%), and lumbar in 7 (28%) of the 25 cases. One patient underwent two separate procedures at different spinal sites. Of the 25 brachytherapy sites, 22 also received external beam radiotherapy (EBRT): 5, EBRT with a planned brachytherapy boost; 4, brachytherapy and prompt EBRT after recovery; and 13, brachytherapy as salvage for local failure after prior EBRT. Three had no EBRT: 1 had lymphoma treated with chemotherapy, 1 had remote previous EBRT for a childhood tumor, and 1 refused EBRT. The mean follow-up was 19.8 months. The 2- and 3-year actuarial local control rate was 87.4% and 72.9%, respectively. Four sites (16.0%) experienced local failure. The mean time to recurnced local failure. The mean time to recurrence for these 4 patients was 20.3 months. Three of the four had failed prior EBRT, with surgery and brachytherapy used for salvage. The 2- and 3-year actuarial overall survival rates were 24.0% and 16.0%, mean 19.2 months. An ambulatory function score was assigned pre- and postoperatively: I, normal ambulation; II, abnormal not requiring assistance; III, abnormal requiring assistance; and IV, unable to ambulate. All patients with score I, 91% of those with score II, 67% of those with score III, and 67% of those with score IV were ambulatory after the procedure; 84% had either normal or improved ambulation postoperatively. Morbidity was restricted to four postoperative events: one cerebrospinal fluid leak, two wound infections treated in situ without removal of seeds or instrumentation, and one pulmonary embolus. No myelopathies or other neurologic sequelae were encountered. Conclusion: This is the largest series in the literature exploring surgery and 125I brachytherapy in the treatment of malignant spinal cord compression. We found this to be well tolerated and to result in durable local control and ambulatory function. Our results suggest a benefit to aggressive local therapy in selected patients with spinal cord compression

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

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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 ...

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

2013-01-01

32

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

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

33

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)

34

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

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

35

Radiochemotherapy with interstitial implantation of 125I seeds and 5-FU slow-release seeds for recurrent thyroid cancer  

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Objective: To investigate the combined treatment technological feasibility, efficacy with interstitial implantation of 125I seeds and 5-FU slow-release seeds for recurrent thyroid cancer. Methods: From March 2002 to December 2003, 9 cases of recurrent thyroid cancer were treated with radiochemotherapy. They were all patients with recurrent thyroid cancer after operation and radiation. The authors implanted alternately 125I seeds and 5-FU slow-release seeds by guiding of treatment planning system. The MPD of 125I seed implantation were 60-90 Gy. The mean 8 granules of 125I seeds and 5-FU 200 mg were used in every patient. Results: Fully operating procedure was accomplished for all the patients. No operating complication occurred. No displacement of 125I seeds was found by cervical X-ray. CT scan showed that the reduced size of tumor changed in different degree. The CR was 11.11%(1/9). The PR was 66.66%(6/9). The NC was 22.22% (2/9). Following up 8-26 months, all patients survived. Conclusion: Using radiochemotherapy with interstitial implantation of 125I seeds and 5-Fu slow-release seeds is safe, minimally invasive and effective for treatment of recurrent thyroid cancer

36

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

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Full Text Available Abstract Purpose The present study aimed to explore the safety profile and clinical efficacy of CT-guided radioactive seed implantation in treating local recurrent rectal carcinoma. Materials and methods CT-guided 125I seed implantation was carried out in 20 patients with locally recurrent rectal carcinoma. 14 of the 20 patient had prior adjuvant external-beam radiation therapy (EBRT. The treatment planning system (TPS was used preoperatively to reconstruct three dimensional images of the tumor and to calculate the estimated seed number and distribution. The median matched peripheral dose (MPD was 120 Gy (range, 100-160 Gy. Results Of the 20 patients, 12 were male, 8 were female, and ages ranged from 38 to 78, with a median age of 62. Duration of follow-up was 3-34 months. The response rate of pain relief was 85% (17/20. Repeat CT scan 2 months following the procedure revealed complete response (CR of the tumor in 2 patients, partial response (PR in 13 patients, stable disease (SD in 3 patients, and progressive disease (PD in 2 patients. 75% of patients had either CR or PR. Median survival time was 18.8 months (95% CI: 3.5-22.4 months. 1 and 2 year survival rates were 75% and 25%, respectively. 4 patients died of recurrent tumor; 4 patients died of distant metastases; 9 patients died of recurrent tumor and distant metastases. 3 patients survived after 2 year follow up. Two patients were found to have mild hematochezia, which was reversible with symptomatic management. Conclusion CT-guided 125I seed implantation appeared to be a safe, useful and less complicated interventional treatment option for local recurrent rectal carcinoma.

Chen Kemin

2011-10-01

37

Radiochemotherapy with interstitial implantation of 125I seeds and 5-FU slow-released seeds for recurrent colorectal adenocarcinoma  

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Objective: To investigate the feasibility, security, and short-term efficacy of combined treatment of interstitial implantation of 125I seeds and 5-FU slow-released seeds for recurrent colorectal adenocarcinoma. Methods: From December 2001 to December 2005, 26 eases of recurrent colorectal adenocarcinoma underwent Mile's procedure were treated with the radiochemotherapy. We implanted alternately 125I seeds and 5-FU slow-released seeds following the treatment planning system. The matched peripheral dose (MPD) of 125I seed implantation was 90-130 Gy. Twelve granules of 125I seeds and 600 mg of 5-FU were administered in every patient on average. Results: No operation-related complication was occurred during the implantations for all the cases. No displacement of 125I seed was found by pelvic X-ray examination. Lenitive rate of the pain was 88.9% (16/18) .The relief has lasted for 5-10 days on average. CT scanning showed that the size of tumor reduced in various degree at 3-6 months after the implantation. The complete recovery rate was 7.7 % (2/26), the partial recovery rate was 73.1% (19/26). The PD was 15.4% (4/26).The median survival time was 29 months estimated by following these cases for 6-42 months. One case died of bone and lung metastases at 6 months after the implantation. Conclusion: Combined radiochemotherapy with interstitial implantation of 125I seeds and 5-FU slow-released seeds was a safe a and 5-FU slow-released seeds was a safe and effective microinvasive treatment for recurrent colorectal carcinoma. (authors)

38

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

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

39

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

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

40

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

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

Reis, Lucas P.; Cardoso, Simone C., E-mail: lpr@cdtn.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Fisica da Radiacao Gama; Facure, Alessandro, E-mail: facure@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Silva, Ademir X. da, E-mail: ademir@con.ufrj.b [Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

2009-07-01

 
 
 
 
41

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

International Nuclear Information System (INIS)

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

42

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

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

43

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

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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

44

Preparation of 125I seed sources for implantation therapy of prostate cancer  

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The scope of the research was to optimize the adsorption of 125I on core seeds using radiochemical techniques. The encapsulation, the Ag bar uniformity adsorption and self-shielding of 125I seed source were investigated. The chemical processing and TIG (tungsten inert gas) welding technology of 125I seed source bar were studied. Silver bar chlorination, iodination and self absorption of 125I were quantified; for example, reagent selection of chlorination and iodination, reagent quantity, reaction time, processing bar, reaction medium, reaction rate and temperature were measured. The quality control of 125I seed source was performed. The adsorption efficiency of 125I in a large batch production was found very high. The homogeneity and reproducibility of 125I seed source between batch and intra-batch was considered optimal. (author)

45

Radioactive seed 125I implantation plus Gemcitabine in treatment for peripheral non-small cell lung cancer  

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Objective: To investigate the clinical value of radioactive seed 125I implantation combined with Gemcitabine (GEM)in treatment for peripheral non-small cell lung cancer(NSCLC). Methods: 60 patients (male 35, female 27, mean age 73.3) with peripheral lung carcinoma were confirmed under CT-guided biopsy including 8 bronchoalveolar carcinomas and 17 squamous carcinomas, 6 in the stage I, 14 in the stage II, 34 in the stage III and 6 in the stage IV were designated under clinical staging. All patients were divided into two groups as GEM group and GEM-125I group. GEM group underwent chemotherapy with GEM only and GEM-125I group was treated under CT guided radioactive seed 125I implantation combined with Gemcitabine. Results: GEM group showed tumors under controlling as PR in 5, SD in 14, PD in 11 cases; the total effective rate was 16% and the total control rate was 63%. The median survival time was 7 months and one years survival rate was 26%. GEM-125I group revealed CR in 5, PR in 11, SD in 8, PD in 6 cases and the total effective rate reached 36% with total control rate as 80%. The median survival time was 12.3 months and one year survival rate was 50%. There was a significant difference (P125I implantation combined with Gemcitabinep>I implantation combined with Gemcitabine in treatment for the patients with peripheral non-small cell lung cancer (NSCLC)has fine clinical efficiency with minimal damage and few complications. (authors)

46

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

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

47

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

48

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

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

49

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

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

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

2014-11-01

50

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

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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)

51

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

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

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

2013-05-15

52

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

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

53

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

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

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

2009-12-15

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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)

55

Efficacy of 125I seed implantation as an adjunctive therapy for extrahepatic metastasis of primary hepatocellular carcinoma  

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Objective: To evaluate the efficacy of 125I seed implantation for extra-hepatic metastasis of primary hepatocellular carcinoma (HCC) treatment. Methods: The clinical records of 26 patients with primary HCC and extrahepatic metastasis were reviewed. Twenty six patients had 31 primary hepatic lesions, 14 patients had 32 lung metastasis, 6 had 8 bone metastasis and 6 had 8 hepatohilar or retroperitoneal lymphatic metastasis. The hepatic lesions were treated by combination of transcatheter arterial chemo- embolization(TACE) and radiofrequency ablation(RFA) or percutaneous ethanol injection (PEI) and were followed up by contrast-enhanced CT (CECT) after 1 month. The extra-hepatic lesions were treated by 125I seeds implantation and were followed up by CECT 3 months after treatment. The treatments were evaluated by imaging examinations. The patients were followed up every 1 month during the first half year, including CT examinations of chest, abdomen and lesions and chest films. Telephone follow-up were performed every 3 months after the 6th month till they were lost and the survival time were calculated. Results: Of the extra-hepatic lesions, 16 cases were complete response (CR), 3 cases were partial response (PR), 4 cases were stable disease (SD) and 3 were progressive diseases (PD). Of the hepatic lesions, 11 were CR, 4 were PR, 6 were SD and 5 PD. The 26 patients are survived at the time of end of follow-up (7.0 to 24.0 months). The median survival (7.0 to 24.0 months). The median survival duration was 14.5 months. Conclusions: 125I seed implantation integrated interventional and minimally invasive therapy could improve the life and survival and it is an effective adjunctive therapy for primary hepatocellular carcinoma with metastasis outside the liver. (authors)

56

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

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

57

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

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

Zhang Jinlei

2012-11-01

58

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 growlls can kill tumor cells, inhibit the growth cycle of tumor cells and induce the apoptosis of tumor cells in nude mice. (authors)

59

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

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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)

60

Dosimetric characteristics of three new design 125I brachytherapy sources  

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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.)

 
 
 
 
61

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

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

62

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

63

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

64

The effect of seed orientation deviations on the quality of 125I prostate implants  

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We quantified the effect of seed orientation deviations on five prostate seed implant cases at our institution. While keeping their positions fixed, the iodine-125 seeds were assigned orientations sampled from a realistic probability distribution derived from the post-implant radiographs of ten patients. Dose distributions were calculated with both a model that explicitly includes anisotropy (TG43 anisotropy function) and a point source model (TG43 anisotropy factor). Orientation deviations had only a small influence on prostate dose-volume histograms: the 95% confidence intervals on the volumes receiving 100%, 150% and 200% dose were at most ±0.8%, ±1.1% and ±0.6% of the prostate volume, respectively. The dose-volume histograms of anisotropic seed distributions were marginally better than those with isotropic point-source seeds. Anisotropy caused a displacement of cold spots (regions receiving <100% of the prescribed dose) in <1% of the prostate volume. Our results indicate no net benefit to prostate dosimetry in using more isotropic seeds. Furthermore, we propose a new 'weighted anisotropy function' to better account for the effects of anisotropy when seed orientation is unknown. Conceptually, the TG43 anisotropy factor described in AAPM TG43 averages the effect of anisotropy over all solid angles, with the implicit assumption that all seed orientations are equally probable. In prostate implants, however, seeds are preferentially oriented parallel to the needle aially oriented parallel to the needle axis. The proposed weighted anisotropy function incorporates this non-uniform probability. (author)

65

Comparison of therapeutic effects between CT-guided 125I seed implantation and chemotherapy with Gemcitabine for the treatment of unresectable pancreatic carcinoma  

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Objective: To compare the therapeutic effects of CT-guided 125I seed implantation with simple Gemcitabine chemotherapy for the treatment of unresectable pancreatic carcinoma. Methods: Forty-six untreated patients with unresectable advanced pancreatic carcinoma were randomly divided into two groups: group A (n=22), treated with 125I seed implantation and group B (n=24), treated with intravenous chemotherapy using Gemcitabine only. The clinical benefit response (CBR), objective tumor response (OTR), safety and the improvement of living quality were evaluated and analyzed. Results: Three months after the treatment, the OTR rate of group A and group B was 45.5% and 8.33% respectively (P 0.05). And also, the incidence of hematological toxicity and complication between two groups were of no significant difference. Conclusion: For the treatment of advanced unresectable pancreatic carcinoma, both simple Gemcitabine chemotherapy and 125I seed implantation are able to obtain a moderate objective response, although 125I seed implantation seems to be more effective than Gemcitabine in improving the living quality and survival rate. (authors)

66

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  

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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 stentsected 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)

67

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

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

68

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

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

69

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

70

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

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Purpose: To estimate the perturbation of seed position and urethral dose, subsequent to withdrawal of urethral catheters. Methods and Materials: A mathematical model based on the volume incompressibility of tissues was used to compute seed positions and doses following removal of the Foley. The model assumed that the central axis of the urethra remains stationary, and that prostate tissue and seeds move radially toward the center of the urethra to fill the void left by the catheter. Seed motion has also been measured using transrectal ultrasound. Results: Based on the computations, seeds located originally close to the urethra travel relatively large distances toward the urethra upon Foley removal, whereas seeds located further away move substantially less. This seed motion leads to higher urethral doses than shown in a standard treatment plan. Dose enhancements increase with catheter size, decrease with increasing prostate volume, are more pronounced for 103Pd than for 125I, and range between 3.5% and 32.4%. Postimplant dosimetry is equally affected if images are taken with urethral catheters in place, showing lower urethral doses than actually delivered. Preliminary ultrasound based measurements of seed motion agree with the theory. Conclusion: During the implantation procedure, 12 fr or smaller urethral catheters are preferable to larger diameter catheters if urine drainage is sufficient. Treatment planners should avoid planning seeds at 5 mm nners should avoid planning seeds at 5 mm or closer from the urethra. Special caution is indicated in prostates having about 20 cm3 or smaller volumes, and when 103Pd is used. Postimplant dosimetry is susceptible to the same errors

71

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

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

72

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)

73

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

74

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

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

75

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

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'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)

76

Permanent prostate implants: radiobiology & dosimetry  

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Localised prostate tumours can be treated with low dose rate brachytherapy. Radioactive sources (Iodine-125) are brought into the prostate. Postimplant dose calculations frequently show that the dose delivered to the prostate is lower than the prescribed dose. This problem is investigated by evaluation of the dose distribution of 130 patients four weeks after the implantation of the Iodine seeds (chapter 6). The research was focussed on two implantation techniques and two techniques for imag...

Gellekom, Maria Petronella Regina

2005-01-01

77

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

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

78

Radiation protection after interstitial permanent prostate brachytherapy implants  

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

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

2006-07-01

79

Radiation protection after interstitial permanent prostate brachytherapy implants  

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

80

Influence of 125I seeds para-tracheal implantation on serum level of inflammatory cytokines IL-1?, IL-6 and TNF-? in rabbits  

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Objective: To evaluate the influence of 125I seeds para-tracheal implant on serum level of inflammatory cytokines in rabbits. Methods: 30 rabbits were randomized to 5 groups, 4 study groups and control group. The activities of seeds in study groups ranged from 11.1 MBq (0.3 mCi) to 33.3 MBq (0.9 mCi), and D90 were 21.1 to 139.0 Gy. The false seeds were used in control group. Four seeds with equal activity were implanted between trachea and esophagus in each rabbit under general anesthesia. The seeds were arranged according to the Paris principle. Serum samples were collected prior to, 30, 60 and 90 days after implantation. IL-1?, IL-6 and TNF-? levels were measured by ELISA. Results: All rabbits were healthy and had weight gaining during study period except 5 died. Serum levels of IL-1?, IL-6 and TNF-? at the end of the first, second and third month were all slightly higher than those of pretreatment. However, there was no statistical significance among them except for group 2. Conclusions: Interstitial brachytherapy with 125I seeds might not significantly produce systematic inflammatory reaction on rabbits. (authors)

 
 
 
 
81

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

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

82

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

83

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

84

Use of Cesium-131 radioactive seeds in prostate permanent implants  

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

85

Occupational exposure of professionals during interstitial permanent prostate brachytherapy implants  

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

86

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

87

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

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

88

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

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

89

Post implant dosimetric evaluation of I-125 permanent prostate implants  

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

90

Methodology of quality control for brachytherapy 125I seeds  

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

91

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

92

The effect of local control on metastatic dissemination in carcinoma of the prostate: Long-term results in patients treated with 125I implantation  

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The study evaluates the effect of the locally recurring tumor on the incidence of metastatic disease in early stage carcinoma of the prostate. The probability of distant metastases was studied in 679 patients with Stage B-C/N0 carcinoma of the prostate treated at MSKCC between 1970 and 1985 (median follow-up of 97 months). Patients were staged with pelvic lymph node dissection and treated with retropubic 125I implantation. The actuarial distant metastases free survival (DMFS) for patients at risk at 15 years after initial therapy was 37%. Cox proportional hazard regression analysis of covariates affecting the metastatic outcome showed that local failure, used in the model as a time dependent variable, was the most significant covariate, although stage, grade, and implant volume were also found to be independent variables. The relative risk of metastatic spread subsequent to local failure was 4-fold increased compared to the risk without evidence of local relapse. The 15-year actuarial DMFS in 351 patients with local control was 77% compared to 24% in 328 patients who developed local relapses (p less than 0.00001). The relation of distant spread to the local outcome was observed regardless of stage, grade, or implant dose. Even stage B1/N0-Grade I patient with local control showed a 15-year actuarial DMFS of 82%, compared to 22% in patients with local relapse (p less than 0.00001). The median local relapse-free survival (LRFS) in the 268 patients with local recurrencesin the 268 patients with local recurrences who did not receive hormonal therapy before distant metastases were detected was 51 months, compared to a median of 71 months for DMFS in the same patients (p less than 0.001), consistent with the possibility that distant dissemination may develop secondary to local failure

93

Permanent Breast Seed Implant Dosimetry Quality Assurance  

International Nuclear Information System (INIS)

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

94

Permanent Breast Seed Implant Dosimetry Quality Assurance  

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-05-01

95

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

International Nuclear Information System (INIS)

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

96

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

Directory of Open Access Journals (Sweden)

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

Saika,Takeshi

2008-02-01

97

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 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)

98

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.

99

Standardization of 125I and 238Pu  

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A simple distance-variable detection table on which two detectors can be mounted and moved back and forth facing each other centred on a sample source has been constructed for photon-photon and ?-photon coincidence counting for 125I and 238Pu, respectively. Two NaI(Tl) detectors were used for the standardization of 125I. A Si detector and an NaI(Tl) detector were employed for the standardization of 238Pu. The NaI(Tl) detectors have a very thin aluminium window for measuring low-energy photons from 125I and 238Pu while the Si-detector is a usable-in-air ion-implanted detector for ? particles from 238Pu. A thin collodion film was used for 238Pu samples, whereas a thick polyester film was used for 125I samples to prevent 125I from leaking from the sample. The key comparison result of 125I showed good agreement, and the result of 238Pu was also compared with that of liquid scintillation counting

100

Image fusion techniques in permanent seed implantation  

Directory of Open Access Journals (Sweden)

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

Alfredo Polo

2010-10-01

 
 
 
 
101

Brachytherapy with 125I seeds for the treatment of tumor  

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The 125I is available for brachytherapy with its special biological and physical characters. At present, 125I brachytherapy seeds have been widely used for interstitial implants in several tumour species abroad, especially the prostate cancer. But there are also some problems to be resolved in the treatment

102

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

International Nuclear Information System (INIS)

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

103

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. PMID:25337135

Chang, Lynn

2014-01-01

104

Biological effects of 125I  

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A review of studies on the biological action of 125I is given. The contradiction of available data is noted. It has been found that the considerable after-effect of 125I is observed in cases when the radionuclide gets into the cell as desoxyuridin and becomes a part of DNA exceeding 2-17 times such dangerous nuclides as 131I and 3H in lethal and mutageneous action. From the data obtained it is seen that on 125I and 131I delivery into the organism in form of sodium salt 131I is marked by a higher toxicity. It should be noted that most of the effects were studied only in early periods after nuclide delivery. There is evidence, however, that 125I produces a higher blastomogenic effect as compared to 131I. In this connection, a systematized study of the effect of different 125I doses on the organism both in early and remote periods after its delivery is of interest. An estimation of the biological 125I effect is necessary to substantiate recommendations of maximum permissible levels, to estimate the risk of using 125I and the comparative efficiency of 125I and 131I

105

Permanent and temporary pacemaker implantation after orthotopic heart transplantation  

Scientific Electronic Library Online (English)

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

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

2000-01-01

106

Effects of permanent I-125 interstitial implantation on cortical bone  

International Nuclear Information System (INIS)

From 1973 to 1980, 1427 cancer patients were treated by the Brachytherapy Service, Radiation Oncology Department of Memoral Sloan-Kettering Cancer Center (MSKCC) with I-125 permanent interstitial implantation. Concern has been expressed with regard to the possible toxic effects of the low average photon energy 28 keV) of I-125 on bone, secondary to its increased absorption in these tissues because of the photoelectric effect. In an attempt to address this concern with respect to cortical bone, the authors reviewed pertinent data on those patients whose site of implant was at close proximity to osseous tissue in the pelvic, chest wall and head and neck regions. The review included 74 sites in 58 patients having no prior history or clinical evidence of any pathologic or metabolic bony disorder. Local control rate for the 74 implanted sites was 93%. The implanted activity ranged from 1.6 to 48.8 mCi and the implanted volume from 0.5 to 152 cm3. At this follow-up range, there appears to be no excessive osseous toxicity either clinically or radiologically with I-125 permanent implantation

107

Dosimetry of 125I seed interstitial brachytherapy  

International Nuclear Information System (INIS)

Objective: To calibrate and assess the dose distribution of 125I seed brachytherapy. Methods: Twenty 125I seeds, each with activity of 12.2 MBq, were implanted on the circumference of a circle 15 mm across in a phantom. Into a designed prostate model, 70 125I seeds were implanted in four planes. The absorbed dose rate of the target volume was monitored by Farmar-2570 dosimeter and thermoluminescence dosimeters (TLD) with the isodose curves drawn on Kodak films. Results: The central dose rates of the circular target volume assessed by Farmar-2570 and TLD were 8.4, 7.9 cGy/h in the phantom and 12.0, 11.1 cGy/h in the prostate model. For the target volume of the prostate model, the total absorbed dose was 24219 cGy. The dose rate 4 cm from the prostate cancer as shown by the isodose curves was only 10% of the central dose rate. Conclusion: The central dose rate of target volume measured by the two methods are similar

108

Placement of 125I implants with the da Vinci robotic system after video-assisted thoracoscopic wedge resection: A feasibility study  

International Nuclear Information System (INIS)

Purpose: To evaluate the feasibility of using the da Vinci robotic system for radioactive seed placement in the wedge resection margin of pigs' lungs. Methods and materials: Video-assisted thoracoscopic wedge resection was performed in the upper and lower lobes in pigs. Dummy 125I seeds embedded in absorbable sutures were sewn into the resection margin with the aid of the da Vinci robotic system without complications. In the 'loop technique,' the seeds were placed in a cylindrical pattern; in the 'longitudinal,' they were above and lateral to the resection margin. Orthogonal radiographs were taken in the operating room. For dose calculation, Variseed 66.7 (Build 11312) software was used. Results: With looping seed placement, in the coronal view, the dose at 1 cm from the source was 97.0 Gy; in the lateral view it was 107.3 Gy. For longitudinal seed placement, the numbers were 89.5 Gy and 70.0 Gy, respectively. Conclusion: Robotic technology allows direct placement of radioactive seeds into the resection margin by endoscopic surgery. It overcomes the technical difficulties of manipulating in the narrow chest cavity. With the advent of robotic technology, new options in the treatment of lung cancer, as well as other malignant tumors, will become available

109

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

International Nuclear Information System (INIS)

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

110

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)

111

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

International Nuclear Information System (INIS)

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

112

Prophylactic urethral stenting with Memokath® 028SW in prostate cancer patients undergoing prostate 125I seed implants: phase I/II study  

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Full Text Available Purpose: To study the feasibility/toxicity of urethral stenting with the Memokath® 028SW stent in patients undergoing prostate implant (PI for prostate adenocarcinoma. Material and methods: An Investigational Device Exemption from the Food and Drug Administration (FDA and institutional review board (IRB approval were obtained. Twenty patients enrolled. Baseline American Urological Association (AUA score was obtained prior to PI. Follow-up information was obtained with weekly phone calls for the first 12 weeks and biweekly calls for the next 12 weeks to assess toxicity and AUA score. Removal of the stent was planned at six months after PI, or earlier due to excessive toxicity/patient request. Results: Median age was 66.5 years. The median prostate volume was 39 cc (range: 10-90. The median baseline AUA score was 7.5 (range: 1-21. Three patients required intermittent self-catheterization (ISC within 3 days after PI. No patients required ISC beyond day 3 after PI. The median duration of ISC was 1 day (range: 1-2. AUA scores returned to baseline values 6 weeks after PI. The week 6 AUA score was 10 (range: 4-16. Seven patients (35% underwent early removal because of patient preference. The reasons were: incontinence (n = 3, discomfort (n = 2, hematuria (n = 1, and obstructive symptoms (n = 1. The median time of stent removal in these patients was 13.9 weeks (range: 0.9-21.4. Thirteen patients (65% had ISC and/or urinary catheterization post stent removal. Median time for ISC use was 10 days (range: 1-90. Conclusions: Urethral stenting with Memokath® in patients undergoing PI was feasible, but resulted in relatively high rate of urinary incontinence and discomfort. Given the adverse effects experienced by patients of this study, further studies should focus only on patients with highest risk of urinary obstruction from PI or those with obstruction needing ISC.

Samuel T. Chao

2011-03-01

113

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)

114

Interstitial radiotherapy of meningiomas treated with permanent I-125 implantation  

International Nuclear Information System (INIS)

Introduction: Microsurgical removal is usually the best treatment modality for intracranial meningiomas and they are usually cured by complete removal. Paracellar and clival meningiomas located near critical structure are difficult to treat surgically. In old patients surgical mortality and morbidity is considerably increased. Stereotactic radiosurgery and interstitial radiotherapy are adjunct treatment methods. Material and methods: We treated 25 paracellar/clival meningiomas (median age 56 y) and 19 meningiomas in the elderly (median age 77 y) with I-125 seeds using stereotactic implantation. I-125 seeds were implanted permanently in 80 target points within 44 tumours. Seven implantations were made under CT control. The average dose to the tumour margin was between 100-150 Gy. The total dose to the optic nerve was between 50-100 Gy and the surface dose to the pons was limited to 100 Gy. In two cases CT scan showed a misplaced seed, located near the tumour surface. Results and discussion: Meningiomas responded by slow reduction, but none disappeared during a median follow-up of 19 months. In the aged the median relative tumour volume was 73% at 3 months, 66% at 6 months and 46% at 12 months. Of 22 paracellar/clival meningiomas with CT follow-up data at ? 6 months, 4 had shrunk moderately, 13 slightly and 5 not at all. Conclusion: Stereotactic implantation of I-125 seeds into intracranial meningiomas is a simple and mini-invasive procedure. CT-scans showed that mostive procedure. CT-scans showed that most meningiomas responded by shrinking slowly but the follow-up time is so far too short to evaluate long-term outcome

115

PSA nadir after 125I prostate brachytherapy  

International Nuclear Information System (INIS)

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

116

Cell scale 125I microdosimetry  

International Nuclear Information System (INIS)

The full text of the publication follows. The aim of this study is to derive microdosimetric data from 125I Auger electron irradiation at cellular and subcellular scales within the context of Radioimmunotherapy (RIT). 125I decays through electronic capture and internal conversion processes, resulting in the emission of Auger electron cascades at the end of the process. The energy of 125I Auger electrons is mainly between some eV and 1 keV, resulting in a short path length in biological matter (from about 2 nm to 500 nm) when compared to average cell dimensions. Preclinical cell experiments performed at IRCM [1][2] showed strong differences in cellular response depending on the position of 125I labeled antibodies. This may be due to large statistical fluctuations of energy deposition within the target cell and, consequently, within radiosensitive organelles like nucleus, membrane or mitochondria. To understand the fundamental mechanisms of radiation damage at the cellular scale in the context of RIT, we decided to use Monte-Carlo methods to give account of the stochastic nature of energy deposition from Auger electrons at the subcellular scale. The first part of our study will compare three Monte-Carlo codes at low energy electrons: -) Geant4DNA, a recent extension of the general Monte-Carlo code Geant4 for very low energies, from a few eV to TeV [3]; -) CPA100, a step-by-step Monte-Carlo code developed by Terrissol in Toulouarlo code developed by Terrissol in Toulouse down to 10 eV [4]; -) PENELOPE version 2008.1 for energies from 50 eV to 1 GeV [5]. Then, realistic cells and sources configurations will be modeled for a realistic 125I Auger electron emission spectrum in Geant4DNA in order to derive microdosimetric parameters such as specific or lineal energy. References: [1] Pouget J.P., Santoro L., Raymond L., Chouin N., Bardies M., Bascoul-Mollevi C., Huguet H., Azria D., Kotzki P.O., Pelegrin M., Vives E. and Pelegrin A., 'Cell membrane is a more sensitive target than cytoplasm to dense ionization produced by Auger electrons', Radiat. Res., vol. 170(2), p. 192-200 (2008); [2] Santoro L., Boutaleb S., Garambois V., Bascoul-Mollevi C., Boudousq V., Kotzki P.O., Pelegrin M., Navarro-Teulon I., Pelegrin A., Pouget J.P., 'Non-internalizing monoclonal antibodies are suitable candidates for 125I radioimmunotherapy of small-volume peritoneal carcinomatosis', J. Nucl Med, vol. 50(12), p. 2033-2041 (2009); [3] Chauvie S., Francis Z., Guatelli S., Incerti B., Mascialino B., Moretto P., Nieminen P., Pia M.G., 'Geant4 Physics Processes for Microdosimetry Simulation: Design Foundation and Implementation of the First Set of Models', IEE Trans. Nucl. Sc., vol.54(6), P. 2619-2628 (2007); [4] Terrissol M., Beaudre A., 'Simulation of space and time evolution of radiolytic species induced by electrons in water', Rad. Prot. Dos., vol.31(1), p.175-177 (1990); [5] Baro J., Sempau J., Fernandez-Varea J.M., Salvat F., 'PENELOPE: An algorithm for Monte Carlo simulation of the penetration and energy loss of electrons and positrons in matter', Nucl. Instr. And Meth. Phys. Res., vol.100(1), p.31-46 (1995). (authors)

117

PSA bounce after permanent implant prostate brachytherapy may mimic a biochemical failure  

International Nuclear Information System (INIS)

Purpose. To assess the frequency of the PSA 'bouncing' phenomenon after a significant follow-up in a series of patients treated by j permanent implant brachytherapy for a prostate cancer. To look for the clinical and dosimetric parameters possibly linked to this transitory secondary PSA increase. To evaluate in which percentage of cases this bouncing could have mimicked a biochemical relapse according to the ASTRO consensus criteria. Patients and methods. From January 1999, to December 2001, 295 patients were treated by a permanent prostate implantation (real-time technique, with free 125I seeds- Isoseed Bebig-) by the Institut Curie-Hopital Cochin-Hopital Necker Paris group. The mean follow-up is 40.3 months (9--66 months). The PSA level was regularly checked, at least every 6 months. We defined as a 'bouncing' all increase in PSA, starting at 0.1 ng/ml, subsequently followed by a spontaneous (without any treatment) decrease, with return to the previous level or lower. We particularly focused on the patients fulfilling the criteria for a biochemical relapse according to the ASTRO consensus (Three successive increases in PSA). A multivariate analysis tried to identify independent factors among the usual clinical and dosimetric parameters. Results. In our series, 161 patients (55%) showed a transitory PSA increase (bouncing) of at least 0.1 ng/ml; 145 patients (49%) a bouncing of 0.2 ng/ml, 93 patients (32%) a bouncing of 0.4 ng/ml and 43 patients (15%) a bong of 0.4 ng/ml and 43 patients (15%) a bouncing of at least 1 ng/ml. Mean PSA bounce was 0.8 ng/ml (0.1 .1), and mean time to bounce was 19 months. Thirty-two patients (11% of the total number) presented three successive PSA increases with a significant (3 months) interval between the dosages, and therefore were to be considered as being in biochemical relapse according to the ASTRO consensus criteria. Actually, among those 32 patients, 18 (56%) subsequently showed a complete normalization of their PSA, without any treatment. Ten patients went on increasing their PSA, and were considered to be really in biochemical relapse. For the last 4 patients, the situation still remains ambiguous. In multivariate analysis, age 200 Gy (P 200 Gy were found to be independent factors predicting for such a secondary transitory increase in PSA. Interestingly, among 32 patients fulfilling the classical criteria of the ASTRO for a biochemical relapse, 18 (560/0) subsequently showed a spontaneous PSA decrease, demonstrating that the ASTRO consensus is not well adapted to the biochemical follow-up of our patients undergoing permanent implant prostate Brachytherapy. (authors)

118

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

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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

119

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

120

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

International Nuclear Information System (INIS)

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

 
 
 
 
121

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

Science.gov (United States)

...Permanent Implant Brachytherapy Medical Event Reporting AGENCY: Nuclear Regulatory...violations of regulations for reporting medical events occurring under an NRC licensee's...SECY-05-0234, ``Adequacy of Medical Event Definitions in 10 CFR...

2013-07-09

122

Absorbed dose determination for interstitial 125I boost therapy  

International Nuclear Information System (INIS)

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

123

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)

124

CT guided 125I seed brachytherapy for recurrent rectum cancer  

International Nuclear Information System (INIS)

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

125

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)

126

Effectiveness of Permanent Implantable Catheter (Polysite) in Children with Cancer  

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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 b...

Hashemizadeh Hayede; Hiradfar M; Borumand Hale

2012-01-01

127

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

International Nuclear Information System (INIS)

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

128

125I decay in synthetic oligodeoxynucleotides  

International Nuclear Information System (INIS)

The availability of synthetic oligodeoxynucleotides provides the opportunity to study the effects of 125I in DNA with added precision and detail, compared to an earlier study (Martin and Haseltine, Science 214, 296, 1981). The authors have designed a template/primer system which enables incorporation of 125IdC into a defined location in a 31mer. The main advantage of this approach is that relatively large amounts (a few ?Ci) of DNA with both 32P and 125I can be produced quite easily. Consequently, when 125I-induced DNA damage is analyzed on DNA sequencing gels, the distribution of 32P-labeled cleavage products can be determined more accurately, following accumulation of decay events under various conditions (e.g. temperature, buffer components, free radical scavengers). The results of preliminary experiments suggest that the yield of DNA strand breaks per decay approaches one, at least for the 125I labeled strand. Extension of this experimental approach will also enable investigation of the nature of the terminii (e.g. phophoryl-versus phophorylglycollate) at either side of 125I decay-induced DNA strand breaks. The question of energy migration is also being investigated in the oligodeoxynucleotide system, by studying the effects of inclusion of BrUdR nucleotides at various distances from the 125IdC

129

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)

130

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

131

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

132

Dosimetry of 125I seed eye plaques  

International Nuclear Information System (INIS)

The ability of a brachytherapy treatment-planning computer program to calculate accurately the dose from 125I seeds at distances relevant to eye plaque therapy was investigated. Thermoluminescent dosimetry measurements were made in a plastic phantom at depths of 0.5, 0.97, and 1.5 cm, and results were corrected for finite dosimeter size and phantom effects. Doses were calculated at the same depths with an 125I seed linear source model that accounted for dose anisotropy. Measurements and calculations were found to agree within their mutual uncertainties. The presence of a gold plaque was found to reduce the dose at all measured depths by 8%

133

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

International Nuclear Information System (INIS)

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

134

Influence of Prostatic Edema on 131CS Permanent Prostate Seed Implants: A Dosimetric and Radiobiological Study  

International Nuclear Information System (INIS)

Purpose: To study the influence of prostatic edema on postimplant physical and radiobiological parameters using 131Cs permanent prostate seed implants. Methods and Materials: Thirty-one patients with early prostate cancer who underwent 131Cs permanent seed implantation were evaluated. Dose-volume histograms were generated for each set of prostate volumes obtained at preimplantation and postimplantion days 0, 14, and 28 to compute quality indices (QIs) and fractional doses at level x (FDx). A set of equations for QI, FDx, and biologically effective doses at dose level Dx (BEDx) were defined to account for edema changes with time after implant. Results: There were statistically significant differences found between QIs of pre- and postimplant plans at day 0, except for the overdose index (ODI). QIs correlated with postimplant time, and FDx was found to increase with increasing postimplant time. With the effect of edema, BED at different dose levels showed less improvement due to the short half-life of 131Cs, which delivers about 85% of the prescribed dose before the prostate reaches its original volume due to dissipation of edema. Conclusions: Results of the study show that QIs, FDx, and BEDs at the level of Dx changed from preneedle plans to postimplant plans and have statistically significant differences (p 131C seed implantation, the effect of edema must be accounted for when defining the seed positions, to avoid the possibility of poor dosimetric and radiobiologic results for 131Cs seed implants.

135

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

Energy Technology Data Exchange (ETDEWEB)

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

Ravi, Ananth [Department of Medical Biophysics, University of Toronto (Canada); Caldwell, Curtis B [Department of Medical Biophysics, University of Toronto (Canada); Keller, Brian M [Medical Physics, Sunnybrook Health Sciences Centre (Canada); Reznik, Alla [Department of Medical Biophysics, University of Toronto (Canada); Pignol, Jean-Philippe [Department of Medical Biophysics, University of Toronto (Canada)

2007-09-21

136

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

Science.gov (United States)

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

Ravi, Ananth; Caldwell, Curtis B.; Keller, Brian M.; Reznik, Alla; Pignol, Jean-Philippe

2007-09-01

137

Current prospects for 125I in tumour therapy  

International Nuclear Information System (INIS)

To evaluate 125I as a tool in tumour therapy, microdosimetric data, results from animal experiments and information obtained from clinical applications are presented. Numbers and energies of electrons and photons emitted were calculated to determine the energy deposition in critical biological targets (spheres of 20 nm diameter) after incorporation of 125IUdR. The total energy deposited per decay includes the energy imparted to Auger electrons (0.96 keV) and the ionization potential (1.07 keV) which is built up in consequence of the electron cascade. The latter will be locally absorbed. Thus, 125I acts like a high-LET radiator. In animal experiments tumour bearing mice were continuously injected intravenously with cold IUdR and 125IUdR. Tumour regression improved from 10% for the controls to 25% after infusion of 2x10-4mol/L IUdR and to 31% after infusion of 200 ?Ci of 125IUdR per mouse, respectively. In clinical applications two patients with advanced squamous carcinomas of the tongue and buccal cavity were locally intra-arterially perfused with 125IUdR. To the first patient 50 ?Ci 125IUdR were administered via the arteria lingualis every 12 h followed at day 12 by 500 ?Ci 125IUdR per 12 h period. In the second patient 'interport' catheters were implanted in the arteria carotis externa. Twenty-five ?Ci were infused 10-18 h daily for 44 days, to a total of 1080 ?Ci. for 44 days, to a total of 1080 ?Ci. Retained activities remained below the expected levels in both patients and the treatments were discontinued. To render more promising the application of 125I in tumour therapy it appears necessary to specifically augment 125IUdR uptake in tumour DNA. (author)

138

Preparation of 125I labelled compound  

International Nuclear Information System (INIS)

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

139

Biodistribution properties of two 125I labeled novel neurotensin analogues  

International Nuclear Information System (INIS)

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

140

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

Energy Technology Data Exchange (ETDEWEB)

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

Luo, Wei, E-mail: wei.luo@uky.edu; Molloy, Janelle; Aryal, Prakash; Feddock, Jonathan; Randall, Marcus [Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536 (United States)

2014-02-15

 
 
 
 
141

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

International Nuclear Information System (INIS)

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

142

Results of a phase II trial of transrectal ultrasound-guided permanent radioactive implantation of the prostate for definitive management of localized adenocarcinoma of the prostate (Radiation Therapy Oncology Group 98-05)  

International Nuclear Information System (INIS)

Purpose: To evaluate the effectiveness of transrectal ultrasound-guided permanent radioactive 125I implantation of the prostate for organ-confined adenocarcinoma of the prostate compared with historical data of prostatectomy and external beam radiotherapy within a cooperative group setting. Methods and Materials: Patients accrued to this study had histologically confirmed, locally confined, adenocarcinoma of the prostate with clinical Stage T1b, T1c, or T2a, no nodal or metastatic disease, prostate-specific antigen level of ?10 ng/mL, and Gleason score of ?6. All patients underwent transrectal ultrasound-guided radioactive 125I permanent seed implantation into the prostate. The prescribed dose was 145 Gy to the prostate planning target volume. Results: A total of 27 institutions accrued a total of 101 patients to this protocol, with no institution accruing >8 patients. Six patients were ineligible, leaving 95 properly entered as eligible in the study. The median follow-up was 5.3 years (range, 0.4-6.5 years). At 5 years, 5 patients had local failure, 1 had evidence of distant failure, and 6 (6%) had biochemical failure. The overall survival rate at 5 years was 96.7%. At last follow-up, no patient had died of prostate cancer or related toxicities. Eight patients had a maximal acute toxicity level of 3, and no patient had Grade 4 or 5 acute toxicity. During follow-up, 2 patients had maximal Grade 3 toxicity, both related to bladder issues, and , both related to bladder issues, and no patient experienced Grade 4 or 5 toxicity. Conclusion: The results of this clinical protocol (a multi-institutional trial of brachytherapy for localized adenocarcinoma of the prostate) have demonstrated that this type of trial can be successfully completed through Radiation Therapy Oncology Group. Biochemical disease-free survival was comparable with other brachytherapy published series and with the results after surgery and external beam radiotherapy

143

Postenucleation orbits in retinoblastoma: treatment with 125I brachytherapy  

International Nuclear Information System (INIS)

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

144

Concurrent versus sequential application of ferromagnetic hyperthermia and 125I brachytherapy of melanoma in an animal model.  

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OBJECTIVE: To determine the efficacy of concurrent versus sequential ferromagnetic hyperthermia (FMH), combined with Iodine-125 (125I) brachytherapy, in the treatment of uveal melanoma in a rabbit model. MATERIALS AND METHODS: A Greene melanoma cell line was implanted in rabbit eyes to establish a tumor model comparable to a uveal melanoma. Seventy-one tumor-containing rabbit eyes were treated with 125I brachytherapy at 20, 25, 35, 45, or 55 Gray (Gy)(38 eyes), and with either concurrent (15 ...

Mieler, W. F.

1997-01-01

145

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

International Nuclear Information System (INIS)

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

146

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

International Nuclear Information System (INIS)

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

147

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

International Nuclear Information System (INIS)

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

148

Dispersion of iodine (125I) and trapping of dispersed 125I by charcoal cartridges  

International Nuclear Information System (INIS)

The dispersal rates of 125I defined here as a dispersed activity in Bq per hour divided by the total activity contained in a solution, and the collection efficiency of dispersed 125I by charcoal cartridges were measured under the various pH conditions in the solution. The values of dispersal rate observed under working conditions in common biochemical procedures were (3.74±1.19) x 10-4 (h-1), (4.27±1.90) x 10-4 (h-1) and (6.31±2.05) x 10-4 (h-1) for alkaline, neutral and acidic conditions of the solution, respectively. And those values obtained by the evaporation of solution to dryness were elevated more than 100 to 1000 times independent of pH of the solution. Under the case of common biochemical procedures, nearly 90% of the dispersed 125I was trapped on the 1st charcoal cartridge which was inserted between dispersal part and exhaust part. NO 125I was detected in the following 2nd and 3rd charcoal cartridges. (author)

149

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.)

150

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

151

Permanent interstitial implantation of 125Iodine seed for thoracic malignant tumors  

International Nuclear Information System (INIS)

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

152

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)

153

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

International Nuclear Information System (INIS)

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

154

Radiobiological effect induced by different activities of 125I seed brachytherapy in a hepatocellular carcinoma model  

Science.gov (United States)

Background: Iodine 125 (125I) seed irradiation is an effective non-surgical treatment for unresectable hepatocellular carcinoma (HCC) patients. However, the safety and tolerability of 125I seed sequential irradiation therapy remain unclear, there is no unified standard of brachytherapy radiation dose, and further study on the basic radiobiology of continuous rate irradiation is necessary. Methods: Forty Kunming-mice (KM-mice, China) were injected with suspensions of human hepatocellular carcinoma cells (H22) to create an animal model and mimic 125I seed implantation. The survival rates of mice, curative effect, pathological impairments including apoptosis and necrosis were investigated. The mice were randomly divided into four groups, A, B, C and D. In group A, 0.78 mCi 125I seeds were implanted into the tumor focus. In groups B and C, 0.58 mCi and 0.38 mCi 125I seeds were inserted at the same location, respectively. Group D was a control group, without any treatment. After 28 days of therapy, the survival rates and the tumor size were measured, and pathological impairments was measured by light or electron microscopy. Results: The tumor volume inhibition rate was 68.21% ± 3.21%, 51.38% ± 4.96%, and 35.71% ± 2.79% after 0.78 mCi, 0.58 mCi, and 0.38 mCi 125I seeds irradiation, respectively. However, radiation-related side effects were also observed in the high-dose group. Pathological results showed that radiation effect was closely associated with radiation dose, as the increase of radiation dose, an increase in apoptosis and necrosis was detected. Significant cellular impairments were noted by pathological analysis under electron microscopy. Conclusions: Our results demonstrate that the Kunming-mouse is an ideal animal to study 125I brachytherapy, and the curative effect was closely associated with radiation dose. High-dose of brachytherapy may effectively increase apoptosis and necrosis in liver cells in KM-mice. A dose of 0.58 mCi 125I radioactive particles may be a safe, effective and minimally invasive therapeutic option for liver cancer. PMID:25664029

Qin, Qing-Hong; Huang, Bai-Sha; Tan, Qi-Xing; Yang, Wei-Ping; Lian, Bin; Wei, Chang-Yuan

2014-01-01

155

Intraoperative modification method in the transperineal permanent implant of I-125 seed in prostate cancer  

International Nuclear Information System (INIS)

In the Department of Radiation Therapy and Oncology, International Medical Center of JAPAN, transperineal permanent implant (TPI) of I-125 seeds have been performed since April 2004. In April the planning method was changed from the preplanning to the intraoperative modification method in April 2006. Various dose parameters were compared between the 106 patients treated by preplanning and the 42 patients undergoing the intraoperative modification. The mean operation time was 84 minutes in the preplanned method and 92 minutes in the intraoperative modification. The prostatic volume reduced at the postplanning, compared to the preplanning. Dosimetric parameters of prostate (V100, V150, and D90%) diminished at the time of postplanning with a statistical significance, while the degree of the reductions was greater in the patients treated by the preplanned method. The mean prostate V100 of the preplanning and the intraoperative modification was 89% and 93.3%, respectively, and the mean prostate D90% was 100% and 111%, respectively, both with a statistically significant difference. In contrast, urethral and rectal dose parameters were the same in both methods. The intraoperative modification method was useful to attain the high quality permanent implant of I-125 seeds. (author)

156

Preliminary results with iodine-125 seeds for permanent implantation in patients with localized prostatic cancer  

International Nuclear Information System (INIS)

Since August 1981, a permanent implantation with iodine-125 seeds has been performed in 41 patients with localized prostatic cancer. The seeds are implanted through a suprapubic incision. This gives the opportunity also to perform a diagnostic dissection of the regional lymph nodes. In five patients, the nodes were positive. In 4 out of these 5 patients bone metastases became manifest within one year. Two patients died of disseminated tumor, the first also had a local recurrence. Two other patients died shortly after treatment because of heart failure, while a third patient also died of heart failure, 2 years after implantation. Out of 31 patients with a follow-up period of 6 months or longer, distant metastases were found in four, in 2 followed by a local recurrence in the prostate. It is concluded that the preliminary results of this technique are encouraging with only three local recurrences in 41 patients. The prognostic value of positive lymph nodes was once again established. 10 refs.; 2 figs.; 1 table

157

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

Science.gov (United States)

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

158

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

159

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)

160

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)

 
 
 
 
161

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).

162

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

International Nuclear Information System (INIS)

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

163

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

164

Experimental study on H22 hepatoma treated by 125I seeds interstitial brachytherapy  

International Nuclear Information System (INIS)

Objective: To evaluate the effectiveness of 125I seeds interstitial brachytherapy in the treatment of H22 hepatoma in mice and to observe the influence on the surrounding tissues and organs. Methods: Twenty days after the establishment of H22 hepatoma in mice models (n=20), all mice were anesthetized by intraperitoneal injection of 10% chloral hydrate (0.4 g/kg), and the tumor mass measured after laparotomy was about 0.49 cm in average diameter. 125I seeds were implanted into the tumors and then irradiated the tumors for 10 d. Then mice were anesthetized again and the 125I seeds were removed. The size of tumors was re-measured. Whole blood counts, liver function tests, pathologic examinations and electronic microscope of tumor tissues, surrounding liver and intestine tissues were performed. The expression of proliferating cell nuclear antigen (PCNA) was evaluated by immunohistochemical method. Results: After irradiation all mice were alive, and the average diameter of tumors was about 0.23 cm [P0.05, as compared with normal group (n= 10)]; Hb, RBC and PLT had no distinct change, but WBC decreased obviously (P125I seed interstitial brachytherapy is a feasible and effective method for the treatment of H22 hepatoma in mice, but also has certain influence on the surrounding tissues and organs. (authors)

165

Radiation exposure after permanent prostate brachytherapy  

International Nuclear Information System (INIS)

Background and purpose: Limited information is available on the true radiation exposure and associated risks for the relatives of the patients submitted to prostate brachytherapy with permanent implant of radioactive sources and for any other people coming into contact with them. In order to provide appropriate information, we analyzed the radiation exposure data from 216 prostate cancer patients who underwent 125I or 103Pd implants at the European Institute of Oncology of Milan, Italy. Patients and methods: Between October 1999 and October 2004, 216 patients with low risk prostate carcinoma were treated with 125I (200 patients) or 103Pd (16 patients) permanent seed implantation. One day after the procedure, radiation exposure measurements around the patients were performed using an ionization chamber survey meter (Victoreen RPO-50) calibrated in dose rate at an accredited calibration center (calibration Centre SIT 104). Results: The mean dose rate at the posterior skin surface (gluteal region) following 125I implants was 41.3 ?Sv/h (range: 6.2-99.4 ?Sv/h) and following 103Pd implants was 18.9 ?Sv/h (range 5.0-37.3 ?Sv/h). The dose rate at 50 cm from the skin decreased to the mean value of 6.4 ?Sv/h for the 125I implants and to the mean value of 1.7 ?Sv/h for the 103Pd implants. Total times required to reach the annual dose limit (1 mSv/year) recommended for the general populr) recommended for the general population by the European Directive 96/29/Euratom and by the Italian law (Decreto Legislativo 241/2000) at a distance of 50 cm from the posterior skin surface of the implanted patient would be 7.7 and 21.6 days for 125I and for 103Pd. Good correlation between the measured dose rates and both the total implanted activity and the distance between the most posteriorly implanted seed and the skin surface of the patients was found. Conclusions: Our data show that the dose rates at 50 cm away from the prostate brachytherapy patients are very low and that the doses possibly absorbed by the relatives and other members of the general population coming into contact with the treated patients are well below the dose limit set by the European Directive and by the Italian regulation. However, in order to meet the recommendation of the ALARA principle (As Low As Reasonably/Readily Achievable), some advice to the patients should be given, such as to maintain a minimum distance from the patient of 1 m, at least for a period equal to one half life of used radionuclide (60 days for 125I and 15 days for 103Pd)

166

Monitoring of 125I in saliva of workers internally contaminated with 125I  

International Nuclear Information System (INIS)

Monitoring of workers who did iodination of protein was performed for 5 months on 10 persons. The activity in saliva was evaluated following the sum peak method by using a NaI(Tl) detector and a 400-channel analyzer. The concentration of 125I in saliva ranged 4.65 +- 2.1cBq (1.26 +- 0.57 pCi)/ml to 135 +- 2.7 cBq (36.45 +- 0.73 pCi)/ml and the average was 20.8 +- 1.9cBq (5.62 +- 0.51pCi)/ml. The ratio of concentration in saliva to used activity ranged (2.2 +- 0.64) x 10-9 to (3.6 +- 0.073) x 10-8 and the average was (8.1 +- 1.1) x 10-9. The thyroidal uptake per iodination ranged 146 Bq (3.94nCi) to 2700 Bq (72.9nCi). The ratio of the uptake to the used activity ranged from 7.3 x 10-5 to 5.4 x 10-6. The thyroidal absorbed dose ranged from 378 ?Gy (37.8 mrad) to 4740 ?Gy (474mrad). Monitoring of 125I in saliva was proved to be a useful method to investigate the internal contamination of workers doing iodination. (author)

167

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

International Nuclear Information System (INIS)

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

168

Quality control of 125I-brachytherapy seeds  

International Nuclear Information System (INIS)

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

169

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)

170

Heterogeneity of 125I-labeled human thyroglobulin preparations  

International Nuclear Information System (INIS)

This study was undertaken to evaluate the heterogeneity and stability of 125I-labeled human thyroglobulin (Tg) tracers. Tg, labeled with 125I by either a Chloramine T (CT) or a Glucose Oxidase/Lactoperoxidase (GO) method, showed considerable heterogeneity of labeled components, the relative proportions of which were a function of the Tg preparation and the iodination method used. Definitive purification and repurification of [125I]Tg tracers before use is necessary in order to remove degradation products with the potential to compromise the accuracy and specificity of serum Tg radioimmunoassay (RIA) measurement. (Auth.)

171

CT-guided 125I brachytherapy on pulmonary metastases after resection of colorectal cancer: A report of six cases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Colorectal cancer (CRC) is one of the most common malignancies in the world and distant metastasis is the main cause of cancer-related mortality. Percutaneous computed tomography (CT) guided radioactive 125I seed implantation (CTRISI) is a minimally invasive technique used to treat pulmonary metastases in CRC patients. In the present study, following colorectal cancer resection, six patients with pulmonary metastases were treated with computed tomography (CT)-guided percutaneous implantation ...

Shi, Shuyuan; Yang, Jingkui; Sun, Daqiang

2014-01-01

172

Synthesis and comparison of different 125I-estradiol analog for estrogen radio receptor assay  

International Nuclear Information System (INIS)

Radio Receptor Assay (RRA) for the Estrogen Receptor (ER) is important in cancer diagnostic and drug designation. 7 kinds of 125I-Estradiol analogs: 125I-Estradiol-6-CMO-His, 125I-Estradiol-3-CME-His, 125I-Estradiol-17-HS-His, 2-125I-Estradiol, 4-I-Estradiol, 2, 4-2 125I-Estradiol, 16? 125I-Estradiol were synthesized and compared for Estrogen Radio Receptor Assay. It was found that 16? 125I-Estradiol was better than 3H-Estradiol and other 125I-Estradiol analogs mentioned above for the RRA of Estrogen Receptor. (authors)

173

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

International Nuclear Information System (INIS)

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)

174

Quality control of 125I-brachy therapy seeds  

International Nuclear Information System (INIS)

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

175

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

Science.gov (United States)

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

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

2014-09-01

176

Radiolabeling FAU with 125I and its biodistribution in mice  

International Nuclear Information System (INIS)

Objective: The aim of this study was to label 2'-fluoro-2'-deoxy-l-?-D-arabinofuranosyluracil (FAU) with 125I, and to investigate the characteristics of the labeled compound as well as its bio-distribution in mice. Methods: FAU was radiolabeled with Na125I using the Iodogen method. The Sep-Pak C18 reverse phase column was used to purify the labeled product. The labeling efficiency, radiochemical purity, the in vitro stability and its biodistribution in mice were observed. Results: FAU was successfully labeled with Na125I with the labeling efficiency of (63.12±5.01)%. The radiochemical purity was (98.60 ± 0.52)%. 125I-5-iodo-FAU (FIAU) was stable in PBS and fresh human serum under 37 degree C and the radio-chemical purity remained more than 95.04% after 24 h. Mouse experiment showed that the radiolabeled product was washed out from blood quickly. The uptake expressed as percentage activity of injected dose per gram of tissue (% ID/g) was (4.33±1.00)% ID/g at 0.5 h and (0.71±0.06)% ID/g at 2 h after injection. The 125I-FIAU was mainly excreted through kidney. Conclusions: 125I-FIAU could be obtained by labeling FAU with the Iodogen method with satisfactory labeling efficiency, radiochemical purity and stability. Mouse biodistribution experiment showed it was mainly excreted through kidney. (authors)

177

PSA bounce after brachytherapy with permanent seed implantation for prostate cancer  

International Nuclear Information System (INIS)

The purpose of this study was to evaluate prostate specific antigen (PSA) bounce that may occur as a time PSA rise phenomenon during follow up period after brachytherapy (BT) with permanent seed implantation for prostate cancer. Seven hundred and forty-six patients had undergone BT from November 2003 to April 2007 in a single institute, and of 130 patients who did not receive hormone therapy and had minimal 3-year follow up are analyzed. PSA bounce was defined as a rise of at least 0.4 ng/ml with spontaneous return to pre-bounce level or lower. Among the 130 patients, 40 patients (30.8%) developed PSA bounce, and median time to PSA bounce was 18 months after the BT. With univariate analysis, younger patients (P=0.027) and larger prostate (P=0.030) had statistically significant correlation with PSA bounce. With multivariate analysis, younger patients were identified as only independent factor for predicting PSA bounce. Eight patients out of 130 patients (6.2%) triggered the Phoenix definition (nadir +2 ng/ml) of PSA failure, however, clinical failure was seen only in 3 patients, and other 5 patients were considered as PSA bounce. PSA bounce is likely to occur in younger patients within 3 years after BT. It is clinically important to distinguish PSA bounce from PSA failure during following period after BT. (author)

178

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

179

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-02-15

180

Evaluation of radio- and chemotoxic effects of /sup 125/I-UdR on tumour growth and host survival  

Energy Technology Data Exchange (ETDEWEB)

The toxicity of 5-iodo-2'-deoxyuridine (U-UdR) was assayed in male C57 BL/6J mice bearing the syngeneic mammary adenocarcinoma EO 771 by injecting different doses of ''cold'' I-UdR or 125-iodine labelled I-UdR. Host survival, tumour growth, DNA-precursor incorporation, whole-body retention and tumour activity loss rates were chosen as biological end points. There was no measurable effect on host survival up to doses of 5 ..mu..g I-UdR or 50 ..mu..Ci /sup 125/I-UdR per mouse during a mean life-span of 25 days. Adjusted to a constant amount of 0.55 ..mu..g I-UdR/mouse, radiotoxicity of /sup 125/I-UdR on tumour growth (up to 17 days after implantation), tracer incorporation, whole-body and tumour retention (up to 12 days after /sup 125/I-UdR injection) could be excluded up to a dosage of 50 ..mu..Ci /sup 125/I-UdR/mouse. It is concluded that in situ evaluation of tumour activity loss rates in carcinoma EO 771 is not disturbed by toxic effects of I-UdR or /sup 125/I-UdR within the dose limits mentioned.

Porschen, R.; Porschen, W.; Muehlensiepen, H.; Feinendegen, L.E.

1985-07-01

 
 
 
 
181

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

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

Raghu Cherukupalli

2014-11-01

182

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

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

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

2013-08-15

183

An algorithm for efficient metal artifact reductions in permanent seed implants  

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

184

An algorithm for efficient metal artifact reductions in permanent seed implants  

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

185

Dosimetry of ophthalmic applications using 125I seed sources  

International Nuclear Information System (INIS)

Intraocular melanoma is the most common primary malignancy of the eye and radiation therapy using ophthalmic plaque has proved successful for its management. The dose prescription point recommended for 125I eye plaque therapy is usually 5 mm from tumour base centre for tumours with 5 mm or less height and tumour apex, otherwise. A computational programme was written to generate data for the dosimetry of eye plaque therapy using 125I seeds. Variation of central axis depth dose and isodose distributions at reference depth have been studied for different diameter plaques. The reference dose rate chosen for a clinical application, based on treatment planning software, was compared with that derived from the data generated in the present study. The dosimetry data generated and presented in this paper will help pre-planning of ophthalmic applications, using 125I seeds. (author)

186

Effect of organic matter on 125I diffusion in bentonite  

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

187

Computer assisted treatment planning for 125I ophthalmic plaque radiotherapy  

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

188

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

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

189

Infections associated with permanent pacemakers and implanted cardioverter-defibrillator devices. A 10-year regional study in Denmark.  

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Endocarditis and localized pocket infections are recognized as serious adverse events in patients with implanted cardiac impulse generators. We have undertaken a 10-y retrospective study in North Denmark Region (population 0.5 million) in order to elucidate the clinical spectrum, causative microorganisms, management and outcome. Infections associated with permanent pacemakers (PPM) and implanted cardioverter-defibrillator (ICD) devices were identified by searching hospital databases. Ninety-one incident cases were recorded in 1999 through 2008: 26 patients had endocarditis, 39 patients had a localized pocket infection, and 9 patients developed surgical sepsis with or without local signs immediately after implantation or reoperation; the device was the likely but unconfirmed focus of infection in 17 patients with bacteraemia. Staphylococcus aureus, coagulase-negative staphylococci and other Gram-positive bacteria were the predominant causative agents; only 6 cases were culture-negative. Management included device and lead extraction and individualized antibiotic therapy. The all-cause 30-day case-fatality was 11%. Only 3 recurrences were recorded during 2 y of follow-up. In conclusion, infections associated with permanent impulse generators have a broader clinical spectrum than often reported in the literature. Most cases are culture-positive with staphylococcal predominance. The short-term mortality is notably high, but the risk of recurrence is low. PMID:20465488

Smit, Jesper; Korup, Eva; Schønheyder, Henrik C

2010-09-01

190

125I-ochratoxin and method of its preparation  

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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.)

191

Dosimetric characteristics of the Pharma Seed model BT-125-I source.  

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125I brachytherapy sources are being used with increasing frequency for interstitial implants in tumor sites, especially the prostate. Recently, a new 125I source design has become commercially available for clinical applications. Dosimetric characteristics (i.e., dose rate constant, radial dose function, and anisotropy function) of this source were experimentally and theoretically determined following the AAPM Task Group 43 (TG-43) recommendations and were related to the 1999 NIST calibration assigned to this source [S(k), 99std]. Measurements were performed in a Solid Water phantom using LiF thermoluminescent dosimeters. The measured data were used to validate the Monte Carlo simulations that were performed in Solid Water using the PTRAN code. The Monte Carlo calculations were then performed in liquid water to obtain the dosimetric information for clinical applications in accordance with TG-43 recommendations. The results indicated that the dose rate constant, lambda, of the Pharma Seed model BT-125-I 125I source was 0.90 +/- 0.06 cGy h(-1) U(-1) using thermoluminescent dosimeter (TLD) measurements and 0.92 +/- 0.03 cGy h(-1) U(-1) using Monte Carlo simulations in Solid Water. The calculated value in liquid water was found to be 0.95 +/- 0.03 cGy h(-1) U(-1). The radial dose function, g(r), of the new 125I source was measured at distances ranging from 0.5 to 10 cm using LiF TLD in Solid Water phantom material. The Monte Carlo simulations were performed for distances ranging from 0.1 to 10 cm from the source center in Solid Water and liquid water. The anisotropy function, F(r, theta), was measured at distances of 2, 5, and 7 cm from the source center and calculated at distances of 0.5, 1, 2, 3, 5, and 7 cm from the source center. The anisotropy constant, phi(an), of the Pharma Seed source in water was found to be 0.975. Complete dosimetric data are described in this manuscript. Per TG-43, the values reported in water should be used for clinical treatment planning systems. PMID:11011748

Popescu, C C; Wise, J; Sowards, K; Meigooni, A S; Ibbott, G S

2000-09-01

192

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

International Nuclear Information System (INIS)

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

193

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)

194

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

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

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

2010-07-01

195

Feasibility study of using MOSFET detectors for in vivo dosimetry during permanent low-dose-rate prostate implants  

International Nuclear Information System (INIS)

Purpose: To investigate the feasibility of using new micro-MOSFET detectors for QA and in vivo dosimetry of the urethra during transperineal interstitial permanent prostate implants (TIPPB). Methods and materials: This study involves measurements for several patients who have undergone the implant procedure with iodine-125 seeds. A new micro-MOSFET detector is used as a tool for in vivo measurement of the initial dose rate within the urethra. MOSFETs are calibrated using a single special order calibration seed. The angular response is investigated in a 100 kVp X-ray beam. Results: micro-MOSFETs are found to have a calibration factor of 0.03 cGy/mV for low energy X-rays and a high isotropic response (within 2.5%). Prostate volume and shape changes during TIPPB due to edema caused by the trauma of needle insertion, making it difficult to achieve the planned implant geometry and hence the desired dose distribution. MOSFET measurements help us to evaluate the overall quality of the implant, by analyzing the maximum dose received by urethra, the prostate base coverage, the length of the prostatic urethra that is irradiated, and the apex coverage. Conclusions: We demonstrate that ease of use, quick calibration and the instantaneous reading of accumulated dose make micro-MOSFETs feasible for in vivo dosimetry during TIPPB

196

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%

197

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

International Nuclear Information System (INIS)

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

198

Synthesis of [2-{(4-chlorophenyl) (4-[125I]iodophenyl)} methoxyethyl]-1-piperidine-3-carboxylic acid, [125I] CIPCA: a potential radiotracer for GABA uptake sites  

International Nuclear Information System (INIS)

The synthesis of racemic [2-{(4-Chlorophenyl)(4-iodophenyl)} methoxyethyl]-1-piperidine-3-carboxylic acid, (CIPCA) and its radioiodinated analog [125I]CIPCA is described. CIPCA was synthesized from 4-iodobenzoyl chloride in five steps in 16% overall yield. Ammonium sulfate catalyzed solid-state isotopic exchange of CIPCA with Na125I provided [125I]CIPCA in 34% isolated radiochemical yield at a specific activity of 118 Ci/mmol. [125I]CIPCA demonstrated moderate brain extraction and good in vivo radiostability in preliminary biodistribution studies conducted in CD-1 mice. [125I]CIPCA is a potentially useful radiotracer for study of the GABA uptake system. (author)

199

Hydrophobic labelling of membrane-embedded proteins with lipophilic reagents. Incorporation of [125I]INA and [125I]TID into B lymphocyte membrane immunoglobulins.  

Science.gov (United States)

Hydrophobic labelling is frequently used in the study of membrane-inserted domains of intrinsic proteins. However, the published procedures, fail to incorporate sufficient radioactivity into membrane immunoglobulins of B lymphocytes to permit investigation of their subunit structures and associations with other proteins. In order to increase the specific radioactivity of [125I]iodonaphthylazide ([125I]INA), an improved method for the synthesis of the reagent was developed. In addition, the optimal conditions for labelling B lymphocytes with [125I]INA and the commercially available reagent 3-(trifluoromethyl)-3-(3'-[125I]iodophenyl)diazirine ([125I]TID) were elaborated. Under these optimized conditions, Ig molecules labelled with [125I]INA and [125I]TID were isolated and analysed in detail by SDS-PAGE. The usefulness of the two reagents for the investigation of lipid-embedded domains of membrane proteins is discussed. PMID:2783713

Vogel, L; Hildebrand, A; Tschammer, T; Haustein, D

1989-01-01

200

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

International Nuclear Information System (INIS)

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

 
 
 
 
201

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

International Nuclear Information System (INIS)

The impact of tissue heterogeneity and interseed attenuation is studied in post-implant evaluation of five clinical permanent breast 103Pd seed implants using the Monte Carlo (MC) dose calculation method. Dose metrics for the target (PTV) as well as an organ at risk (skin) are used to visualize the differences between a TG43-like MC method and more accurate MC methods capable of considering the breast tissue heterogeneity as well as the interseed attenuation. PTV dose is reduced when using a breast tissue model instead of water in MC calculations while the dose to the skin is increased. Furthermore, we investigate the effect of varying the glandular/adipose proportion of the breast tissue on dose distributions. The dose to the PTV (skin) decreases (increases) with the increasing adipose proportion inside the breast. In a complete geometry and compared to a TG43-like situation, the average PTV D90 reduction varies from 3.9% in a glandular breast to 35.5% when the breast consists entirely of adipose. The skin D10 increases by 28.2% in an entirely adipose breast. The results of this work show the importance of an accurate and patient-dependent breast tissue model to be used in the dosimetry for this kind of low energy implant.

202

Thermoluminescent dosimetry of the SourceTech Medical model STM1251 125I seed  

International Nuclear Information System (INIS)

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

203

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

Science.gov (United States)

125I brachytherapy sources are being used for interstitial implants in tumor sites such as the prostate. Recently, the ADVANTAGE 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 Water phantom using LiF thermoluminescent dosimeters. The theoretical calculations were performed in both Solid Water and water using the PTRAN Monte Carlo code. The results indicated that a dose rate constant of the new source in water was 0.98 +/- 0.03 cGy h(-1) U(-1). The radial dose function of the new source was measured in Solid Water and calculated both in water and Solid Water at distances up to 10.0 cm. The anisotropy function, F(r, theta), of the new source was measured and calculated in Solid Water at distances of 2 cm, 3 cm, 5 cm, and 7 cm and also was calculated in water at distances ranging from 1 cm to 7 cm from the source. From the anisotropy function, the anisotropy factors and anisotropy constant were derived. The anisotropy constant of the ADVANTAGE 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. PMID:12349937

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

2002-09-01

204

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

205

Thermoluminescent dosimetry of the SourceTech Medical model STM1251 125I seed.  

Science.gov (United States)

Many new models of 125I seeds are being introduced, mainly due to the increase in prostate seed implants. We have evaluated the SourceTech Medical (STM), model STM1251, 125I seed using thermoluminescent dosimeters (TLDs) in a solid water phantom. TLD cubes, LiF TLD-100, with dimension 1 mm on each edge, were irradiated at various distances, 1, 2, 3, and 5 cm, at angles ranging from 0 degrees to 90 degrees in 10 degrees increments. Sensitivity calibration of the TLDs was achieved by irradiation to 10 cGy with 6 MV x rays from a clinical linear accelerator, Clinac 600C. Concurrent with the 125I seed exposures, several TLDs were also exposed to 10 cGy with the 600C as a control set. Dose rates per unit air kerma strength were determined based on the 1999 NIST traceable standard for the STM1251 seed. They are presented as a function of distance r and angle theta. The TG-43 parameters, including the dose rate constant, lambda, anisotropy function, F(r,theta), radial dose function, g(r), anisotropy factor, phian(r), and anisotropy constant, phi, were obtained for use in radiation treatment planning software. The value of lambda was determined as 1.07 +/- 5.5% cGy U(-1) h(-1), which is comparable to model 6702 and to the value determined using the point extrapolation method by Kirov and Williamson. We also find agreement between our TLD data and their Monte Carlo results for g(r), F(r,theta), phian(r), and phi. Additionally, agreement is found with the TLD data of Li and Williamson for lambda and g(r). PMID:12906190

Chiu-Tsao, Sou-Tung; Duckworth, Tamara L; Hsiung, Chih-Yun; Li, Zuofeng; Williamson, Jeffrey; Patel, Neil S; Harrison, Louis B

2003-07-01

206

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)

207

Commercial production of 125I-fibrinogen injection  

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

208

Adsorption of 125I on palladium coated silver wire  

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The adsorption of 125I on palladium coated silver wires was studied in this paper. The experimental conditions, e.g., reaction volume, carrier concentration, reaction time, reaction temperature, pH of the reaction mixture, were systematically optimized to obtain quantitative adsorption of 125I on palladium coated silver wires. The experiments were performed using potassium iodide 8-9 ?g as carrier in a reaction volume of 100 ?L incubated in ? 50 deg C water bath for ? 1 h, and the pH of the reaction system was controlled at 2-2.5. The distribution of activity on palladium coated silver wire was uniform, and the source cores can be easily sealed by laser welding into titanium capsules. (author)

209

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

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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)

210

Preparation of 19-iodocholesterol labelled with 125 I  

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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

211

Comparative biological efficacy of 125I and 131I  

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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

212

125I-neuropeptide Y and 125I-peptide YY bind to multiple receptor sites in rat brain  

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We describe the preparation of monoiodinated neuropeptide Y (Tyr1-125I-NPY) and monoiodinated peptide YY (Tyr36-125I-PYY). Using these ligands, we detected high, moderate, and low affinity receptor populations in rat brain. Only high and moderate affinity binding sites were suggested by saturation binding studies. Tyr1-125I-NPY bound to 8 +/- 3% of the sites with a Kd of 54 pM (Bmax = 19.4 fmol/mg of protein) and to 92 +/- 3% of the sites with a Kd of 0.92 nM (Bmax = 220.0 fmol/mg of protein). Tyr36-125I-PYY bound to 14 +/- 3% of the sites with a Kd of 23.5 pM (Bmax = 36.4 fmol/mg of protein) and to 86 +/- 3% of the sites with a Kd of 1.9 nM (Bmax = 220.1 fmol/mg of protein). The fragments NPY 13-36 and PYY 13-36 were able to compete with 10 pM Tyr1-125I-NPY for essentially all the binding sites. The fragments were 1 to 2 orders of magnitude less potent than the native peptides. Approximately 50% of the moderate affinity sites, but not the high affinity sites, were reversibly lost in the presence of 5'-guanylyl imidophosphate [Gpp(NH)p], a nonhydrolyzable analog of GTP. Kinetic studies revealed that Tyr1-125I-NPY dissociation could be best described by three dissociation rates. The proportions of slow and intermediate dissociation matched the proportions of moderate and high affinity binding sites, respectively, as suggested by equilibrium studies. There also existed a phase of fast dissociation. When Gpp(NH)p was added during dissociation, the proportion of slow diss dissociation, the proportion of slow dissociation decreased to the same extent that the fast dissociation was increased. However, the proportion of intermediate dissociation did not change. We propose that rat brain contains a minor population of high affinity NPY binding sites with an intermediate dissociation rate and no sensitivity to Gpp(NH)p

213

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

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

214

Labeling Lanreotide with 125I and 188Re. China  

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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

215

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

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

216

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

217

New material for low-dose brachytherapy seeds: Xe-doped amorphous carbon films with post-growth neutron activated 125I.  

Science.gov (United States)

We report a novel material for use in (125)I brachytherapy that consists of amorphous carbon films grown by ion-beam-assisted deposition and doped with Xe (5 at%) by implantation. Samples of these films grown on Si substrates were irradiated with neutrons in a TRIGA-I nuclear reactor for the production (125)Xe, and latter characterized by gamma spectroscopy. The results indicate that the (124)Xe was efficiently converted into (125)Xe, the precursor of (125)I, and support the activity calculations for a model brachytherapy seed. PMID:20729094

Gonçalves, R G F; Pinheiro, M V B; Lacerda, R G; Ferlauto, A S; Ladeira, L O; Krambrock, K; Leal, A S; Viana, G A; Marques, F C

2011-01-01

218

New material for low-dose brachytherapy seeds: Xe-doped amorphous carbon films with post-growth neutron activated 125I  

International Nuclear Information System (INIS)

We report a novel material for use in 125I brachytherapy that consists of amorphous carbon films grown by ion-beam-assisted deposition and doped with Xe (5 at%) by implantation. Samples of these films grown on Si substrates were irradiated with neutrons in a TRIGA-I nuclear reactor for the production 125Xe, and latter characterized by gamma spectroscopy. The results indicate that the 124Xe was efficiently converted into 125Xe, the precursor of 125I, and support the activity calculations for a model brachytherapy seed.

219

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 ± 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

220

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

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

 
 
 
 
221

Histopathological comparison of biodegradable polymer and permanent polymer based sirolimus eluting stents in a porcine model of coronary stent implantation.  

Science.gov (United States)

Biodegradable stent coatings were recently introduced as a potential solution to overcome sustained inflammatory responses observed with permanent polymer-based drug-eluting stents. In a preliminary study, selected biodegradable or permanent polymer-based sirolimus-eluting stent (SES) formulations were screened for effectiveness in comparison to bare metal stents (BMS) at 28 days. Subsequently, the most favourable SES formulation was compared to commercially available SES (Cypher™) at 28, 90 and 180 days to investigate the histopathologic response as well as tissue, blood and organ pharmacokinetics. Overlapping SES implantation was conducted to evaluate vascular healing at 28 days in this particular setting. SES with biodegradable poly (L-lactide) polymer (PLLA) or poly(lactide-co-glycolide) showed the most favourable outcome with regards to reductions in neointimal area in comparison to BMS at 28 days. The PLLA SES showed a similar reduction in neointimal area compared to Cypher™ at 28 days, with significant greater reductions at 90 and 180 days (1.7 ± 0.7 mm² vs. 3.1 ± 1.5 mm², p=0.03 and 1.8 ± 1.2 mm² vs. 3.0 ± 1.5 mm², p=0.01, respectively). Sirolimus vascular tissue concentrations were detectable up to 90 days following implantation. Overlapping stented segments showed favourable histopathologic results with respect to fibrin deposition and endothelialisation at 28 days. In conclusion, the use of PLLA as drug-eluting matrix resulted in mild inflammatory responses in the presence of effective sirolimus tissue concentrations. The greater efficacy observed at long-term follow-up in PLLA SES compared to Cypher™ may be a multifactorial result of stent design, polymer biocompatibility and improved release kinetics. PMID:22535188

Koppara, Tobias; Joner, Michael; Bayer, Gerd; Steigerwald, Kristin; Diener, Tobias; Wittchow, Eric

2012-06-01

222

Five-year outcome of intraoperative conformal permanent I-125 interstitial implantation for patients with clinically localized prostate cancer  

International Nuclear Information System (INIS)

Purpose: To report the 5-year tumor control and toxicity outcomes for patients with localized prostate treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique. Methods and Materials: Between January 1998 and June 2002, 367 patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning which incorporated inverse planning optimization was used. The median follow-up time was 63 months. Results: The median V100 and D90 were 96% and 173 Gy, respectively. In 96% of cases a D90 of >140 Gy was achieved. The median urethral and rectal doses were 100% and 33% of the prescription doses, respectively. The 5-year PSA relapse-free survival outcomes for favorable and intermediate risk patients according to the ASTRO definition were 96% and 89%, respectively. In these patients no dosimetric parameter was identified which influenced the biochemical outcome. Of 38% who developed acute Grade 2 urinary symptoms, 63% had resolution of their symptoms within a median time of 6 months. The incidence of late rectal and urinary Grade 3 or higher toxicities were 1% and 4%, respectively. Seven percent (n = 27) developed late rectal bleeding (Grade 2) and 19% experienced late Grade 2 urinary symptoms. Conclusion: Real-time intraoperative planning consistently achieved optimal coverage of the prostate with the prescription dose withe prostate with the prescription dose with concomitant low doses delivered to the urethra and rectum. Biochemical control outcomes were excellent at 5 years and late toxicity was unusual. These data demonstrate that real-time planning methods can consistently and reliably deliver the intended dose distribution to achieve an optimal therapeutic ratio between the target and normal tissue structures

223

125I-progesterone radioimmunoassay for fertility control in cows  

International Nuclear Information System (INIS)

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

224

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

225

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

226

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

International Nuclear Information System (INIS)

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

227

Metabolism of (125I)tyramine cellobiose-labeled low density lipoproteins in squirrel monkeys  

International Nuclear Information System (INIS)

Low density lipoproteins labeled with (125I)tyramine cellobiose ((125I)TC-LDL) were removed from the circulation of squirrel monkeys at a similar but slightly slower rate than LDLs labeled with 125I, (125I)hydroxypenyl propionic acid, or (3H)leucine. After the simultaneous injection of ((125I)TC-LDL) and (131I)LDL labeled with 131ICI, the 125I was also removed at a slightly slower rate than 131I. Most of the radioactivity was retained in tissues and not excreted during the 24 h after injection of (125I)TC-LDL. This finding supports the claim of Pittman et al. (18) that (125I)TC-LDL can be used to determine the irreversible uptake of LDL by different tissues. The liver cleared more LDL than any other organ, but the adrenals and ovaries were more active per gram. Trichloroacetic acid (TCA) precipitated more than 80% of the radioactivity in the tissues that had low 125I uptake, but only about 50% of the 125I in more active tissues (liver, adrenals, ovaries and spleen). Only a small percentage of 125I in urine and bile was TCA-precipitable. In the dual label experiment with (125I)TC-LDL and (131I)LDL there was a selective retention of 125I in samples from liver, spleen, adrenals, and perhaps testes, and an almost complete selectivity for 125I in bile and feces. The ar 125I in bile and feces. The aortic intima plus inner media (AIM) cleared much less LDL than other tissues, but the uptake by the entire AIM was proportional to the cholesterol concentration and weight of the total AIM. There was, however, no correlation between either of the latter two measurements and the uptake of LDL per pram of AIM. (author)

228

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.)

229

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

230

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

231

Comparison of [125I]HIPDm and [125I]iodoantipyrine in quantifying regional cerebral blood flow in rats  

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We determined regional cerebral blood flow (rCBF) using [125I]HIPDm [N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamin e] and [125I]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

232

Studies on the adsorption of 125I on bromide coated silver rods for the preparation of 125I-seeds for brachytherapy applications  

International Nuclear Information System (INIS)

This paper describes a method for the preparation of 125I brachytherapy sources. The process consist of surface oxidation of a silver rods [0.5 mm (?) x 3 mm (1)], formation of a thin silver bromide over layer and finally replacement of bromide ions by 125I- ions. The effect of various parameters such as 125I feed activity, iodide carrier concentration and reaction time were examined and optimized for maximum impregnation of 125I activity on the substrate. Sources containing 74-111 MBq (2-3 mCi) 125I on a silver matrix could be prepared and encapsulated in titanium capsules [0.8 mm (?) x 4.75 mm (1)] using Nd: YAG laser. Quality assurance tests to ensure nonleachability, uniform distribution of activity and leak tightness that are necessary before application were evaluated. (author)

233

CT-guided (125)I brachytherapy on pulmonary metastases after resection of colorectal cancer: A report of six cases.  

Science.gov (United States)

Colorectal cancer (CRC) is one of the most common malignancies in the world and distant metastasis is the main cause of cancer-related mortality. Percutaneous computed tomography (CT) guided radioactive (125)I seed implantation (CTRISI) is a minimally invasive technique used to treat pulmonary metastases in CRC patients. In the present study, following colorectal cancer resection, six patients with pulmonary metastases were treated with computed tomography (CT)-guided percutaneous implantation of radioactive (125)I seeds. At six months following seed implantation, CT examination was performed and compared with the images captured prior to the treatment. Of the total 13 lesions, four had disappeared, eight were reduced by >50% and one was enlarged, indicating that the local control rate was 92.3% (12/13). Overall, two patients developed intraoperative pneumothorax and one experienced hemoptysis subsequent to the procedure. Following a median follow-up period of 31 months, no local recurrence was observed in 12 of the metastatic lesions. The mean survival time was 32.7 months and the median survival time was 31 months. PMID:25435995

Shi, Shuyuan; Yang, Jingkui; Sun, Daqiang

2015-01-01

234

Consumption of 125I labelled fibrinogen in normal subjects  

International Nuclear Information System (INIS)

The metabolism of iodine-125 labeled human fibrinogen is studied by using three different sets of the radiopharmaceutical (0.9, 1.3 and 1.84 iodine atoms/fibrinogen molecule ratios) in 19 normal subjects. An aliquot of 40 ?Ci of fibrinogem-125I is injected in each subject, on normal dietary conditions and blood samples are withdrawn at 30, 60, 180, 36 and 720 minutes after the injection and, thereafter, one daily sample during 10 days. The compartmental distribution of the tracer is defined by plotting plasma and serum sample counts on a semilogarithmic graph paper. A rapid phase and 3 compartments are obtained. A 'rapid' consumption half-life and a 'real' consumption half-life are defined. The fibrinogen clottability is followed up to the last blood sample by checking the ratios of serum and plasma radioactivities

235

106Ru and 125I radiation dose rate gauge  

International Nuclear Information System (INIS)

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

236

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 whenge 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

237

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, respecti22% (unchanged) for PAH and EDTA, respectively

238

Pharmacokinetics and organ distribution of 125I-aprindine  

International Nuclear Information System (INIS)

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

239

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

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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

240

Factors predicting for postimplantation urinary retention after permanent prostate brachytherapy  

International Nuclear Information System (INIS)

Purpose: Urinary retention requiring catheterization is a known complication among prostate cancer patients treated with permanent interstitial radioactive seed implantation. However, the factors associated with this complication are not well known. This study was conducted to determine these factors. Methods and Materials: Ninety-one consecutive prostate cancer patients treated with permanent interstitial implantation at our institution from 1996 to 1999 were evaluated. All patients underwent pre-implant ultrasound and postimplant CT volume studies. Isotopes used were 125I (54 patients) or 103Pd (37 patients). Twenty-three patients were treated with a combination of 45 Gy of external beam radiation therapy as well as seed implantation, of which only 3 patients were treated with 125I. Mean pretreatment prostate ultrasound volume was 35.4 cc (range, 10.0-70.2 cc). The mean planning ultrasound target volume (PUTV) was 39.6 cc (range, 16.1-74.5 cc), whereas the mean posttreatment CT target volume was 55.0 cc (range, 20.2-116 cc). Patient records were reviewed to determine which patients required urinary catheterization for relief of urinary obstruction. The following factors were analyzed as predictors for urinary retention: clinical stage; Gleason score; prostate-specific antigen; external beam radiation therapy; hormone therapy; pre-implant urinary symptoms (asymptomatic/nocturia x 1 vs. more significant urinary symptoms); pretreatment gnificant urinary symptoms); pretreatment ultrasound prostate volume; PUTV; PUTV within the 125%, 150%, 200%, 250%, 300% isodose lines; postimplant CT volume within the 125%, 150%, 200%, 250%, 300% isodose lines; D90; D80; D50; ratio of post-CT volume to the PUTV; the absolute change in volume between the CT volume and PUTV; number of needles used; activity per seed; and the total activity of the implant. Statistical analyses using logistic regression and ?2 were performed. Results: Eleven of 91 (12%) became obstructed. Significant factors predicting for urinary retention were the total number of needles used (p < 0.038); the pretreatment ultrasound prostate volume (p < 0.048); the PUTV (p < 0.02); and the posttreatment CT volume (p < 0.021). Two of 51 patients (3.9%) requiring 33 or fewer needles (median) experienced obstruction vs. 9 of 40 (22.5%) requiring more than 33 (p < 0.007). If the pretreatment ultrasound prostate volume was 35 cc or less (median), 3 of 43 (7%) vs. 8 of 36 (22%) with a volume greater than 35 cc experienced obstruction (p < 0.051). Conclusion: The number of needles required (perhaps related to trauma to the prostate) and the prostate volumes were significant factors predicting for urinary retention after permanent prostate seed implantation.

 
 
 
 
241

125I seed irradiation induces up-regulation of the genes associated with apoptosis and cell cycle arrest and inhibits growth of gastric cancer xenografts  

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Full Text Available Abstract Background Iodine 125 (125I seed irradiation can be used as an important supplementary treatment for unresectable advanced gastric cancer. Here, we aim to comprehensively elucidate the biological effects induced by 125I seed irradiation in human gastric cancer xenograft model by using global expression and DNA methylation analyses. Methods The 48 mice bearing NCI-N87 gastric cancer xenografts were randomly separated into 2 groups: sham seeds (O mCi were implanted into the control group (n?=?24; 125?l seeds (0.9?mCi were implanted into the treatment group (n?=?24. The mitotic index and apoptotic index were evaluated by quantitative morphometric analysis of the expression of proliferating cell nuclear antigen (PCNA and in situ terminal transferase-mediated fluorescein deoxy- UTP nick end labeling (TUNEL, respectively. Global gene expression changes induced by 125I seed irradiation were analyzed by using Nimblegen Human gene expression array. DNA methylation profile in the tumors from control group was investigated with methylated DNA immunoprecipitation (MeDIP and Nimblegen CpG promoter microarrays. The changes in the methylation status of selected genes were further investigated by using MeDIP-PCR. Results 125I seed irradiation suppresses the growth of gastric cancer xenografts in nude mice. PCNA staining and tissue TUNEL assays showed that both inhibition of cell proliferation and induction of apoptosis contribute to the 125I-induced tumor suppression in nude mouse model. Gene expression profiles revealed that the expression levels of several hundred genes, many of which are associated with apoptosis or cell cycle arrest, including BMF, MAPK8, BNIP3, RFWD3, CDKN2B and WNT9A, were upregulated following 125I seed irradiation. Furthermore, the up-regulation of some of these genes, such as BNIP3 and WNT9A, was found to be associated with irradiation-induced DNA demethylation. Conclusions This study revealed that 125I seed irradiation could significantly induce the up-regulation of apoptosis- and cell cycle-related genes in human gastric cancer xenografts. And some of the up-regulation might be attributed to 125I-irradiation induced demethylation in gene promoter regions. Collectively, these findings provided evidence for the efficacy of this modality for the treatment of gastric cancer.

Ma Zhen-Huan

2012-07-01

242

125I disk source using charcoal activated polyurethane foam rubber mat  

International Nuclear Information System (INIS)

Uniform 125I disk sources were prepared as a reference source to calibrate NaI(Tl) scintillation detector to measure 125I activity on a filter of air monitor in a laboratory. The base of the disk source was a charcoal activated polyurethane foam rubber mat of 75 mm in diameter, 2 mm in thickness. 125I disk sources of approximate 0.5 kBq, 1 kBq, and 10 kBq were obtained through immersing disks in ethanol solution containing Na125I of 0.5 kBq/ml, 1 kBq/ml and 10 kBq/ml, respectively, and then drying up them. The uniformity of the distribution of 125I on the disk source was estimated by analyzing the autoradiograph of the disk source using an imaging analyzer. The radioactivity of 125I was distributed uniformly on the surface of the disk source within an uncertainty of about 10%. (author)

243

In vivo molecular imaging of [125I]-labeled 3-iodothyronamine: A hibernation-inducing agent  

International Nuclear Information System (INIS)

The present investigation was carried out with the objective of studying in vivo imaging of 3-iodothyronamine (T1AM) compound in mice. A simple and efficient synthesis of [125I]–T1AM was established, and a molecular imaging study was performed using micro-SPECT/CT at 1 h post-injection of [125I]–T1AM. Imaging studies revealed the activity in the gastrointestinal tract and liver, indicating that [125I]–T1AM was distributed primarily in the liver, and excreted into the gastrointestinal tract through a bile duct. - Highlights: ? A SPECT/CT imaging of [125I]–T1AM has been performed in a mouse. ? A radiochemical yield of [125I]–T1AM was 40%, and the radiochemical purity was >99%. ? T1AM was also synthesized to compare with [125I]–T1AM

244

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

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

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

2009-11-06

245

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

International Nuclear Information System (INIS)

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

246

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

International Nuclear Information System (INIS)

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

247

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.)

248

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

International Nuclear Information System (INIS)

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

249

Bystander effects caused by nonuniform distributions of DNA-incorporated 125I  

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A three-dimensional tissue culture model was used to investigate the biological effects of nonuniform distributions of DNA-incorporated 125I in mammalian cells. Chinese hamster V79 cells were labeled with 125I-iododeoxyuridine, mixed with unlabeled cells, and multicellular clusters (~ 1.7 mm in diameter) were formed by gentle centrifugation. The highly localized energy deposition caused by 125I decays results in very high equivalent doses delivered to the labeled cells and low equivalent dose...

Howell, Roger W.; Bishayee, Anupam

2002-01-01

250

Binding and degradation of (/sup 125/I)human growth hormone in rat adipocytes  

Energy Technology Data Exchange (ETDEWEB)

Iodinated human growth hormone (( /sup 125/I)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 (/sup 125/I)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 /sup 125/I released was soluble in 5% trichloroacetic acid and was in the form of iodotyrosine. The rate of /sup 125/I 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 /sup 125/I that bound to cells when (/sup 125/I)hGH was present in the medium, but completely blocked the release of /sup 125/I from cells transferred to hormone-free medium. Ammonium chloride also significantly reduced both the release of /sup 125/I from nonspecific binding sites and the amount of /sup 125/I recovered in trichloroacetic acid-soluble form. Cloroquine, leupeptin, or colchicine nearly doubled the specific binding of (/sup 125/I)hGH after 180 min and markedly slowed the release of /sup 125/I when cells were transferred to hormone-free medium. All of these agents also significantly reduced the rate of release of /sup 125/I 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.

Gorin, E.; Grichting, G.; Goodman, H.M.

1984-08-01

251

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. Inc/sup>I 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

252

Chemical form of the radioactive excretion products after intravenous application of 125I-orthoiodohippurate to rats  

International Nuclear Information System (INIS)

100 ?Ci 125I-orthoiodohippurate were injected i.v. to 2 Wistar rats. Urine and faeces were analysed by means of thin-layer chromatography and high-pressure liquid chromatography. The metabolites found were 125I-orthoiodobenzoic acid, 125I-orthoiodohippuric acid, and 125I-iodide. (orig./MG)

253

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)

254

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.)

255

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)

256

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

257

Synthesis of [125I]IodoDPA-713, a New Probe for Imaging Inflammation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

[125I]IodoDPA-713 [125I]1, which targets the translocator protein (TSPO, 18 KDa), was synthesized in seven steps from methyl-4-methoxybenzoate as a tool for quantification of inflammation in preclinical models. Preliminary in vitro autoradiography and in vivo small animal imaging were performed using [125I]1 in a neurotoxicant-treated rat and in a murine model of lung inflammation, respectively. The radiochemical yield of [125I]1 was 44 ± 6% with a specific radioactivity of 51.8 GBq/?mol (1...

Wang, Haofan; Pullambhatla, Mrudula; Guilarte, Tomas R.; Mease, Ronnie C.; Pomper, Martin G.

2009-01-01

258

Binding cells of 125I-iodoamphetamine in rat liver  

International Nuclear Information System (INIS)

We recently reported that transrectal or intestinal portal scintigraphy with 123I-iodoamphetamine (IMP) could be a useful method for the non-invasive and quantitative evaluation of the portosystemic shunt in portal hypertension, but what cells in the liver trap IMP has not been clarified. This study was aimed at elucidating whether IMP was extracted by parenchymal cells, sinusoidal endothelial cells, Kupffer cells or fat storing cells. Each type of liver cell was isolated from rats and cultured. The cells were incubated with 125I-IMP and the radioactivity of the lysate was determined. Nonspecific binding was assessed in the presence of an excess of unlabeled IMP, and specific binding was determined by subtracting the nonspecific from total binding. Specific binding observed in parenchymal cells, endothelial cells and Kupffer cells was 70.2±0.4, 4.2±1.4 and 2.3±0.8 pmol/well, respectively, but no specific binding was observed in fat storing cells. The binding in parenchymal cells was much higher than that in endothelial cells or Kupffer cells (p<0.005). In addition, the binding to parenchymal cells reached equilibrium within 20 min and was not saturable over the concentration range tested (0.5-10 ?M). These findings indicate that IMP is mostly extracted by parenchymal cells in the liver. (author)

259

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)

260

Reutilization of 125I-UdR during growth of a solid mammary carcinoma: Implications for the 125I-UdR loss technique  

International Nuclear Information System (INIS)

Reutilization of thymidine (TdR) and 5-iodo-2'-deoxyuridine (I-UdR) released by dying tumour cells as assayed in the syngeneic adenocarcinoma EO 771 by injecting heat killed, labelled tumour cells into tumours. 3H and 125I liberation from labelled breakdown products was measured in tumours of various sizes without or with separation of tumours into viable and necrotic portions. Internal reutilization of 3H-TdR was considerably greater than that of 125I-UdR. 125I-UdR released by dying tumour cells was reutilized at about 10%. There was no significant increase in 125I-UdR reutilization during tumour growth. It is concluded that measurements of radioactivity loss by the 125I-UdR technique can result in underestimating the real cell loss depending on the amount of internal reutilization by the tumours investigated. Compared with 3H-TdR 125I-UdR is the tracer of choice for long term studies of cell loss. (orig.)

 
 
 
 
261

Reutilization of /sup 125/I-UdR during growth of a solid mammary carcinoma: Implications for the /sup 125/I-UdR loss technique  

Energy Technology Data Exchange (ETDEWEB)

Reutilization of thymidine (TdR) and 5-iodo-2'-deoxyuridine (I-UdR) released by dying tumour cells as assayed in the syngeneic adenocarcinoma EO 771 by injecting heat killed, labelled tumour cells into tumours. /sup 3/H and /sup 125/I liberation from labelled breakdown products was measured in tumours of various sizes without or with separation of tumours into viable and necrotic portions. Internal reutilization of /sup 3/H-TdR was considerably greater than that of /sup 125/I-UdR. /sup 125/I-UdR released by dying tumour cells was reutilized at about 10%. There was no significant increase in /sup 125/I-UdR reutilization during tumour growth. It is concluded that measurements of radioactivity loss by the /sup 125/I-UdR technique can result in underestimating the real cell loss depending on the amount of internal reutilization by the tumours investigated. Compared with /sup 3/H-TdR /sup 125/I-UdR is the tracer of choice for long term studies of cell loss.

Porschen, B.; Porschen, W.; Muehlensiepen, H.; Feinendegen, L.E.

1987-11-01

262

¿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

263

¿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

264

Impact of target volume coverage with Radiation Therapy Oncology Group (RTOG) 98-05 guidelines for transrectal ultrasound guided permanent Iodine-125 prostate implants  

International Nuclear Information System (INIS)

Purpose: Despite the wide use of permanent prostate implants for the treatment of early stage prostate cancer, there is no consensus for optimal pre-implant planning guidelines that results in maximal post-implant target coverage. The purpose of this study was to compare post-implant target volume coverage and dosimetry between patients treated before and after Radiation Therapy Oncology Group (RTOG) 98-05 guidelines were adopted using several dosimetric endpoints. Materials and methods: Ten consecutively treated patients before the adoption of the RTOG 98-05 planning guidelines were compared with ten consecutively treated patients after implementation of the guidelines. Pre-implant planning for patients treated pre-RTOG was based on the clinical target volume (CTV) defined by the pre-implant TRUS definition of the prostate. The CTV was expanded in each dimension according to RTOG 98-05 and defined as the planning target volume. The evaluation target volume was defined as the post-implant computed tomography definition of the prostate based on RTOG 98-05 protocol recommendations. Implant quality indicators included V100, V90, V100, and Coverage Index (CI). Results: The pre-RTOG median V100, V90, D90, and CI values were 82.8, 88.9%, 126.5 Gy, and 17.1, respectively. The median post-RTOG V100, V90, D90, and CI values were 96.0, 97.8%, 169.2 Gy, and 4.0, respectively. These8%, 169.2 Gy, and 4.0, respectively. These differences were all statistically significant. Conclusions: Implementation of the RTOG 98-05 implant planning guidelines has increased coverage of the prostate by the prescription isodose lines compared with our previous technique, as indicated by post-implant dosimetry indices such as V100, V90, D90. The CI was also improved significantly with the protocol guidelines. Our data confirms the validity of the RTOG 98-05 implant guidelines for pre-implant planning as it relates to enlargement of the CTV to ensure adequate margin between the CTV and the prescription isodose lines

265

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

266

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

International Nuclear Information System (INIS)

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

267

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

268

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)

269

Digital monitor of 125I in thyroid glands of human being  

International Nuclear Information System (INIS)

A new digital monitor of 125I in thyroid glands is described. This instrument is used to measure the activity of 125I in thyroid glands of human being directly, rapidly, and accurately. Furthermore, it can calculate and display the intake, committed dose equivalent and committed effective dose equivalent

270

Synthesis and biodistribution of 125I-labelled benzothiazole derivatives as ?-amyloid imaging agents  

International Nuclear Information System (INIS)

In order to develop 123I labelled probe for SPECT imaging of A ? plaques in Alzheimer's disease. Four 125I labelled benzothiazole derivative are synthesized and their radiochemical purity are more than 95%. The biodistribution results in normal mice indicate that the radiolabelled probes have higher initial brain uptake: 10.28, 3.62, 3.33 and 3.71%/g at 2 min post i.v. injection for 3'-125I-BTA, 3'-125I-CBTA, 3'-125I-BTA-Ac and 3'-125I-CBTA-Ac respectively. Brain uptake ratios at 2 min to 60 min of 3'-125I-BTA, 3'-125I-BTA-Ac and 3'-125I-CBTA-Ac are 7.3, 6.2 and 5.7 respectively. The results reveal that 3'-123I-BTA is a very potential agent for SPECT imaging of A ? plaques in Alzheimer's disease

271

Incineration system for the disposal of 125I-radioimmunoassay test tube wastes  

International Nuclear Information System (INIS)

Before incineration of disposed RIA test tubes, residual 125I radioactivity should be measured for the purpose of radiation safety. This confirmation method has been carried out according to the followings: (1) Residual 125I radioactivity of test tubes in the plastic bag was measured from outside with the low-energy ?-ray survey meter (S1371, Ohyo Kohken Co., Ltd.) newly developed by one of the authors. (2) Gaseous 125I released from the residual 125I-compounds in test tubes by radiation self decomposition was adsorbed by the activated carbon fiber filter(ACFF), and was measured. From the above 2 methods, the minimum detectable concentration of residual 125I in waste tubes would be reached under a level of about 100mBq/g (2.8x10-6?Ci/g). (author)

272

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

International Nuclear Information System (INIS)

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

273

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

International Nuclear Information System (INIS)

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

274

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

International Nuclear Information System (INIS)

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

275

Effectiveness of the I-125 seed permanent implant for localized prostate cancer with the intraoperative planning technique. Comparison with pre-planning technique  

International Nuclear Information System (INIS)

The purpose of this study was to report the effectiveness of the I-125 seed permanent implantation for localized prostate cancer with an intraoperative planning method. With one retrospectively compared the two techniques using post-implant CT-based evaluations: a pre-planning method and an intraoperative planning method. Two hundred forty four patients with T2b or less localized prostate cancer underwent the permanent seed implant between September 2003 and March 2006. One hundred twenty two patients were treated with a pre-planning method while the other half patients were treated with an intraoperative planning. Baseline parameters closely resemble in both groups. However, there were important differences in preoperative prostate volume, source activities, needles and operation time of both groups. Based on a month post-implant CT, patients treated with the pre-planning method marked 155.3 Gy in median prostate D90 (minimal dose covering 90% of the prostate volume) and 92.1% in V100 (percent prostate volume receiving 100% of the prescribed dose). While the intraoperative group marked 169.4 Gy and 97.1%, respectively (p<0.01). Prostate D90 and V100 in the intraoperative group was noted as meaningful improvement. Postoperative dosimetry of the urethra and the rectum followed and conducted as planned. Seed implantation with an intraoperative planning method was more effective than the one with a preoperative planning method. We plan to expand its use of the treatment e plan to expand its use of the treatment in the future. (author)

276

Implants  

Science.gov (United States)

... success of all implants is a process called osseointegration. This is how the bone in the jaw ... years. Many implant systems are available from various dental manufacturers. Success Studies indicate that surgical placement of root-form implants is successful more than 90% of the time. ...

277

Determination of the prescription dose for biradionuclide permanent prostate brachytherapy  

International Nuclear Information System (INIS)

A model based on the linear quadratic model that has been corrected for repopulation, sublethal cell damage repair, and RBE effect has been used to determine the prescription dose for prostate permanent brachytherapy using seeds loaded with a mixture of 103Pd and 125I or a mixture of 103Pd and 131Cs. The prescription dose was determined by comparing the tumor cell survival fractions between the considered biradionuclide seed implant and one monoradionuclide seed implant chosen from 103Pd, 125I, and 131Cs. Prostate edema is included in the model. The influence of the value of the radiobiological parameters and RBE were also investigated. Two mixtures of radionuclides were considered: 103Pd0.75-125I0.25 and 103Pd0.25-131Cs0.75, where the subscripts indicate the fractions of total initial internal activity in the biradionuclide seed. These fractions were selected in order to obtain a dose distribution that lies between that of 103Pd and 125I/131Cs. As expected, the computed prescription dose values are dependent on the model parameters (edema half-life and magnitude, radiobiogical parameters, and RBE). The radionuclide used as a benchmark also has a strong impact on the derived prescribed dose. The large uncertainties in the radiobiological parameters and RBE values produce bigical parameters and RBE values produce big errors in the computed prescribed dose. Averaged over the range of all the parameters and depending on the radionuclide used as a benchmark (in subscript), the derived prescription dose for the first mixture (PdI) would be: DPdPdI=142-16+15 Gy and DIPdI=142-8+6 Gy; and DPdPdCs=128-13+13 Gy and DCsPdCs=115-7+6 Gy for the PdCs mixture. The uncertainties could be reduced if the radiobiological parameters and RBE value were known more accurately. However, as edema characteristics are patient dependent and can be obtained only after the treatment, an unpredictable error is unavoidable.

278

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

International Nuclear Information System (INIS)

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

279

Development of 125I seed source for treatment of eye and prostate cancer  

International Nuclear Information System (INIS)

The adsorption of 125I on silver bits coated with palladium was studied. The adsorbed 125I on Pd coated silver wires could be used as matrix for the preparation of interstitial source. Effective parameters on adsorption of 125I such as temperature, time and carrier volume and concentration were investigated. These experiences showed quantitative and consistent uptake (83%) of 125I and exhibited low leach ability (0.06%). The method is under optimization to obtain higher adsorption of 125I on the palladium treated silver wires. A laser welding machine used for welding of titanium capsules and welding parameters were investigated. Dosimetric parameters of solid core 125I were determined by radiochromic MD-55-2 GAFCHEROMIC film dosimetry. The results of the film dosimetry indicate that nonuniformity of activity around the core is about 8%, also the dose rate at distance of 1cm for active core was 1.133 cGy/hr/mCi. Iso-dose curves around of 125I core have been plotted for 90, 70, 50, 30 and 10 percents using simple image processing software. The results indicated that uniformity of coated activity was good. Production of 192Ir for HDR machine was carried out. 10 Ci 192Ir source with the size of 4.6 mm outer diameter and 6.5 mm length connected to flexible cable by TIG welding was fabricated and sent to hospital for further investigation. (author)ion. (author)

280

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

International Nuclear Information System (INIS)

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

 
 
 
 
281

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

International Nuclear Information System (INIS)

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

282

Labeling of IgG molecules with 125I  

International Nuclear Information System (INIS)

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

283

The origin of 125I and 129I in sheep thyroids from Birmingham, UK  

International Nuclear Information System (INIS)

In this paper the recently reported presence of 125I and 129I in Birmingham slaughtered sheep in 1993 is confirmed. This can be adequately explained by earlier work showing the presence of 125I and 129I in more limited areas than the report would suggest. The 129I must derive from grass grazed in an area centred on the nuclear reprocessing work at Sellafield, Cumbria and extending out to at least 96 km. Iodine-125 derives from water drunk either directly from rivers mainly in the east Midlands and Thames Valley contaminated with low levels of waste 125I, or from mains water extracted from these rivers. (author)

284

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.)

285

Studies with encapsulated 125I sources: dosimetry for determination of relative biological effectiveness  

International Nuclear Information System (INIS)

During the past year, members of this laboratory have measured the Relative Biological Effectiveness (RBE) of photons from encapsulated 125I sources (mean energy = 28.33 keV) using 661.6 keV 137Cs gamma rays as a standard for comparison. These experiments were performed at clinically relevant dose rates and used reduction of the reproductive viability of mammalian cells as an endpoint. This section will discuss how dosimetry problems special to 125I influence the design of the apparatus and will describe the ionization chamber to be used for measuring dose rates from both 125I and 137Cs photons

286

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

287

Effect of fentanyl on 125I-?-CIT uptake in mice brain  

International Nuclear Information System (INIS)

Objective: To investigate the effect of fentanyl on 125I-2?-carbomethoxy-3?-(4-iodophenyl) tropane (125I-?-CIT) uptake in mice brain. Methods: 1) KM mice groups of five were given different doses of fentanyl, and 10 min or 1 h later were given a dose of 125I-?-CIT. 2)Two groups of animals were killed at 2 h after injection of 125I-?-CIT. 3)One group of animals were killed at 1 h after injection of 125I-?-CIT. Results: 1)In the striatum, frontal cortex, hippocampus, brain stem, cerebellum and whole brain, a dose-dependent increase in uptake (%ID/g or %ID) of 125I-?-CIT was detected at the fentanyl doses ranging from 125 to 300 ?g/kg, and the uptakes of hippocampus and cerebellum were higher than that of the controls. There was a great difference in the value of %ID/g or %ID between the group treated with 250 ?g/kg fentanyl and the control group; while at the doses from 12.5 to 100 ?g/kg, a dose-dependent decrease in uptake in the same regions was observed and all the uptake levels were lower (hippocampus: except 62.5 and 12.5 ?g/kg groups; brain stem: except 62.5 ?g/kg group) than that of the controls. 2)The uptakes of 125I-?-CIT in the striatum, frontal cortex, hippocampus, brain stem, cerebellum and whole brain in the groups injected with 125I-?-CIT 10 min after fentanyl treatment were higher than that in the groups injected with 125I-?-CIT 1 h after fent/sup>I-?-CIT 1 h after fentanyl treatment. 3)The binding of 125I-?-CIT in the striatum, frontal cortex, hippocampus, brain stem, cerebellum and whole brain in the groups killed at 1 h after injection of 125I-?-CIT was higher than that in the control group, but without significant difference. Conclusion: Fentanyl may have different effects on 125I-?-CIT at various time points and doses

288

High-sensitivity measurement of 125I in cyclotron-produced 123I  

International Nuclear Information System (INIS)

A Compton suppression spectrometer, constructed from a central Si(Li) detector and a NaI(Tl) scintillator, has been used to determine 125I impurity in 123I for activity ratios D(125I)/D(123I)>=1.2x10-3. The sensitivity afforded by use of this spectrometer permits quantitation of 125I impurity at levels >=3x10-4 relative to 123I prior to release of radioiodinated chemicals or pharmaceuticals for use in manufacturing, research, or medical applications. (author)

289

Measurement of 125I-low density lipoprotein uptake in selected tissues of the squirrel monkey by quantitative autoradiography.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A recently developed technique of absolute quantitative light microscopic autoradiography of 125I-labeled proteins in biologic specimens was used to measure 125I-low density lipoprotein (125I-LDL) concentration levels in various tissues of the squirrel monkey after 30 minutes of in vivo LDL circulation. Liver and adrenal cortex exhibited high 125I-LDL concentrations, presumably because of binding to specific cell surface receptors and/or internalization in vascular beds with high permeability...

Tompkins, R. G.; Schnitzer, J. J.; Yarmush, M. L.; Colton, C. K.; Smith, K. A.

1988-01-01

290

Study of o-125I-benzoate excretion mechanisms in the rabbit  

International Nuclear Information System (INIS)

An analysis of the mechanisms of renal clearance of o-125I-benzoate in the rabbit based on the inhibition of the secretory transport by probenecid showed that o-125I-benzoate was eliminated in the kidneys not only by glomerular filtration but also by tubular secretion. The total amount of the drug excreted in the urine was affected by tubular resorption (apparently by the process of passive diffusion), which exceeded tubular secretion. A comparison of the chromatograms of the plasma and the urine before and after the competitive inhibition of the tubular active transport by probenecid revealed a higher amount of o-125I-benzoylglucuronide in the urine in the case of inhibition. The results suggest that the kidneys participated in the total biotransformation of o-125I-benzoate. The excretion of the original drug and metabolites in the bile contributed less than 1% to the total clearance in rabbits. (author). 3 figs., 3 tabs., 10 refs

291

Tissue uptake and catabolic studies of 125I SS-B (La) injected into mice  

International Nuclear Information System (INIS)

The radiolabeled soluble cellular antigen 125I SS-B (La) has a plasma half-life of 3 min following iv injection into BALB/C mice. Uptake by Kupffer cells (KC) and proximal renal tubular (PRT) cells was demonstrated by autoradiography (ARG). That trichloracetic acid (TCA)-soluble products of 125I SS-B appeared in plasma within 1 min of iv injection suggests rapid in vivo breakdown. Activated peritoneal macrophages (APM) degraded 125I SS-B in a time- and cell-dose-dependent fashion. These findings suggest that the plasma clearance and catabolism of 125I SS-B may be dependent on its interaction with phagocytic cells. This rapid antigen elimination may protect against harmful autoantibody responses

292

Feasibility study of 125I brachytherapy in Indonesia  

International Nuclear Information System (INIS)

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

293

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

International Nuclear Information System (INIS)

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

294

Surface redistribution of 125I-insulin in cultured human lymphocytes  

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The cultured human lymphocyte (IM-9) binds 125I-insulin by a receptor- mediated process; the receptor, in turn, is regulated by the ligand. In the present study we have examined quantitatively the morphologic events involved in 125I-insulin interaction with the surface of the lymphocyte. At 2 min of incubation of 15 degrees or 37 degrees C, the ligand localizes preferentially at the villous surface of the cell, whereas with longer periods of incubation, the ligand distributes indistinguishabl...

1981-01-01

295

Synthesis of 3-[125I]-iodo-phencyclidine for biological studies  

International Nuclear Information System (INIS)

After verification of the biological activity of 3-iodo-phencyclidine (PCP) by binding studies to the N-methyl D-aspartate gated channel, 3-[125I]iodo-PCP was prepared by reaction of sodium iodide with a triazene precursor. The radiochemical yield was optimized and after HPLC purification, 3-[125I]iodo-PCP was obtained with a high radiochemical purity. (author)

296

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

Energy Technology Data Exchange (ETDEWEB)

The synthesis and properties of 2-(/sup 125/I)-lysergic acid diethylamide, the first /sup 125/I-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.

Hartig, P.R.; Krohn, A.M.; Hirschman, S.A.

1985-02-01

297

Synthesis of 123I- and 125I-labelled 5-iodo-6-nitroquipazine  

International Nuclear Information System (INIS)

The syntheses of the potent and selective serotonin reuptake complex radioligands [123I]- and 125I]5-iodo-6-nitroquipazine (5-iodo-6-nitro-2-piperazinylquinoline) are reported. A seven step synthetic sequence provided the BOC-protected 5-tributyltin-6-nitroquipazine precursor for radioiodination. End of sy nthesis radioiodination yields of ? 40% for 123I and ? 60% for 125I were achieved resulting in labelled products with high specific activities (> 4000 and > 2000 Ci/mmol, respectively) and radiochemical purities (> 98%). (author)

298

Radiolabeling of EGCG with 125I and its biodistribution in mice  

International Nuclear Information System (INIS)

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

299

Estrogen receptor assay of mammary cancer by 16 alpha-125I-estradiol  

International Nuclear Information System (INIS)

125I-labeled estradiol (16-?-125I-estradiol-17?) was synthesized from 16-?-Br-estradiol by halogen exchange reaction and purified by high-performance liquid chromatography. The comparative studies of estrogen receptor assays using 125I-E2 and 3H-E revealed that 125I-E2 had the high affinity to cytoplasmic estrogen receptors in rat uteri and human mammary tumor tissues (about 60% of estradiol-17?) and 8S and 4S of estrogen-receptor complexes determined by sucrose density gradient method were identical between 125I-E2 and 3H-E2. The strong coincided rate on the positivity and the negativity of estrogen receptors in human mammary tumor tissues was 97.9% (94/96) and the correlation coefficiency of the binding sites among estrogen receptor assays was r = 0.951 in 41 cases of receptor positive subjects. It made possible to assay estrogen receptor using relatively small amounts of tissues because of the higher radiospecific activity of 125I-E2 than that of 3H-E2. (author)

300

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

Energy Technology Data Exchange (ETDEWEB)

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 {sup 125}I-epidermal growth factor and {sup 125}I-asialofetuin was compared to {sup 125}I-insulin internalization. Pretreatment of cells with anoxia or hyperosmolarity inhibited {sup 125}I-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 {sup 125}I-asialofetuin internalization by greater than 90%. Phenylarsine oxide almost completely abolished {sup 125}I-epidermal growth factor uptake; the other perturbations caused partial inhibition. Competition studies demonstrated that insulin internalization was receptor-mediated over a wide concentration range.

Moss, A.L.

1988-01-01

 
 
 
 
301

DNA strand breakage by 125I-decay in oligoDNA  

International Nuclear Information System (INIS)

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

302

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

International Nuclear Information System (INIS)

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

303

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)

304

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 chhic 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

305

Comparison of sperm abnormalities of mice induced by 125I and 131I  

International Nuclear Information System (INIS)

A comparison of effects of 125I and 131I on the rate of abnormal sperm and the radioactivity in testicles of mice was described. In the experiment, different doses of 125I and 131I was injected intraperitoneally into male ICR mice, respectively. The results show that for mice into which 0.185, 370 and 555 kBq of 125I was injected, rates of abnormal sperm were 9.0%, 9.6%, 11.6% and 13.9% at 4 and 5 weeks after injection, and that for animals into which the above-mentioned doses of 131I were injected, the same parameter was 8.5%, 12.5%, 14.7% and 15.5% respectively. No significant difference (x2 test, p > 0.05) was found in the rate of abnormal sperm of mice between 125I and 131I. For 125I and 131I, the results also show a similar pattern of change in the radioactivity of testicle tissue at 2 hrs and up to 7 days after injection: a peak of radioactivity in testicle tissue was found at 2 hrs after injection and the activity per gram of testicle tissue was 0.72% (for 125I) and 0.50% (for 131I) of the original, then the activity per gram of testicle tissue decreased quickly and only 0.035%(for 125I) and 0.011% (for 131I) of the original at the end of first week after injection

306

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

International Nuclear Information System (INIS)

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

307

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

International Nuclear Information System (INIS)

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

308

Investigation of internalization and cytotoxicity of 125I-[Tyr3]-octreotide in NCI-H446 cell line  

International Nuclear Information System (INIS)

Objective: To investigate the [Tyr3]-octreotide (TOC) internalizing capacity of NCI-H446 cell line, and the cytotoxicity of 125I-TOC in NCI-H446 cell line. To assess the therapeutic radiopharmaceutical potentiality of 125I-TOC for the somatostatin receptor (SSTR) positive tumor. Methods: NCI-H446 cells were incubated together with 125I-TOC for different periods of time, the amount of internalized 125I-TOC and the 125I-TOC bound on the cellular nucleus were detected with ? counter, respectively. The viability of the cells was analyzed by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at different time points with various doses of 125I-TOC, free 125I and TOC. Results: 125I-TOC was internalized into the nucleus and bound on the nucleus in a time-dependent manner. 125I-TOC bound on the nucleus increased to the highest level at 24 h, the amount of nucleus bound 125I-TOC at 24 h was 7 times higher than that at 0.5 h. Cytotoxicity of 125I-TOC in SSTR positive NCI-H446 cells was also dose- and time-dependent. The supreme effect of cytotoxicity was found at 96 h with 74 kBq 125I-TOC, the survival ratio of cells was reduced to (44.8 ± 7.2)%. Conclusions: 125I-TOC can be internalized into SSTR positive cells mediated by SSTR. The NCI-H446 cells can be killed by Auger electron emitting from 125by Auger electron emitting from 125I-TOC. Effect of cytotoxicity showed dose- and time-dependent

309

50th Anniversary of the first successful permanent pacemaker implantation in the United States: historical review and future directions.  

Science.gov (United States)

June 2010 marks the 50th anniversary of the first successful human cardiac pacemaker implantation in the United States. On June 6, 1960, in Buffalo, New York, Dr. William Chardack implanted a pacemaker, designed and built by Wilson Greatbatch, an electrical engineer and inventor, in a 77-year old man with complete atrioventricular block, extending the patient's life by 18 months. This landmark event ushered in a new era of implantable cardiac pacemakers with batteries and leads of high reliability and increasing durability. Over the past half century, the field of electrophysiology and implantable devices for the management of cardiac conduction disturbances has evolved dramatically. Today's pacemakers include increasingly complex features such as telemetry monitoring, auto programmability, and hemodynamic sensors. New-generation leads present a sophisticated design with improved geometry and steroid-eluting tips to reduce chronic inflammation, maintaining a low pacing threshold and high sensing capability. The lithium iodide battery remains the mainstay of implantable pacemaker systems, exhibiting a multiple-year lifespan, slow terminal decay, and a reduced size and cost of production. Although Greatbatch's first successful pacemaker implantation remains a seminal scientific contribution to modern cardiovascular disease management, emerging developments in this field may challenge its preeminence. Important challenges such as imaging compatibility, lead durability, and infection prevention are being addressed. Novel concepts such as leadless and biologic pacing are under active investigation. In conclusion, Greatbatch's historic achievement 50 years ago reminds us that technologic progress is timeless, as efforts to enhance clinical outcomes and the quality of life continue unimpeded into the 21st century. PMID:21391322

Beck, Hiroko; Boden, William E; Patibandla, Sushmitha; Kireyev, Dmitriy; Gutpa, Vipul; Campagna, Franklin; Cain, Michael E; Marine, Joseph E

2010-09-15

310

EGSnrc-based calculation of energy response correction factors for various detector materials for 125I and 169Yb brachytherapy sources  

International Nuclear Information System (INIS)

125I and 169Yb are promising radionuclides for brachytherapy implants. Measurement-based dosimetry for these sources involves the use of various solid detectors used (for example LiF, Li2B2O4, diamond etc). These detectors are generally calibrated against 60Co beam from a telecobalt machine. As the response of the detectors depends on photon energy the measured response requires energy response correction factor. In the present work we derive the correction factors for different detectors for the above-mentioned sources using Monte Carlo methods

311

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

International Nuclear Information System (INIS)

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

312

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)

313

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

International Nuclear Information System (INIS)

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

314

Preparation of 125I-cytarabine and its radiochemical evaluation. Model of radio-therapeutic agent  

International Nuclear Information System (INIS)

Development of a new radiopharmaceutical for cancer imaging and therapy is described. The optimization of the labeling of thymidine analogous, cytarabine, with 125I is described. High radiochemical yield and purity ?98% was obtained by reacting 50 ?g cytarabine with 125I in the presence of iodogen as oxidizing agent and 0.5M phosphate buffer of pH 7 at 65 deg C for 30 minutes. Preliminary in-vivo study was done in non-tumor bearing mice. The results revealed that this new tracer, 125I-cytarabine, has a high affinity to be localized in tissues of high proliferation rate, e.g., bone marrow ?10%, 60-minute post administration. Also, the labeled compound was cleared quickly from most of the body organs and concentrated in bladder ?55%, 60-minute post administration. These findings suggest that 125I-cytarabine, allows imaging and treatment of cancer. 125I-cytarabine meets most of the requirements to be used as a successful diagnostic and therapeutic agent: it is a low molecular weight molecule that diffuses readily in tissues, it well not induce an antibody response, thereby leading itself to repeated injection or continuous infusion. (author)

315

Synthesis and evaluation of serotonin transporter imaging agent [125I]-ADAM  

International Nuclear Information System (INIS)

Synthesis of a new ligand: 2-((2-((Dimethylamino)methyl)phenyl)thio)-5-iodophenylamine (125I-ADAM) as a serotonin imaging agent is reported. The radioiodinated ligand was prepared by iododestannylation reaction using hydrogen proxide. The chemical structure of the labeling precursor (5-(tributylstannyl)-2-((2-((dimethylamino)methyl)phenyl)thio)phenylamine) and all intermediates were verified by IR, HNMR and MS. The radiochemical purity of 125I-ADAM was above 95% determined by TLC. Biodistribution studies in rats showed that the initial uptake of 125I-ADAM in the brain was high, and consistently the highest binding appeared in hypothalamus, a region with the highest density of SERT. The specific binding ((T/CB)-1) of 125I-ADAM in hypothalamus were 3.38, 3.62 and 4.36 at 60 min, 120 min and 240 min postinjection, respectively. These data suggest that 125I-ADAM may be useful for SPECT imaging of SERT binding sites in the brain. (authors)

316

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

317

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

International Nuclear Information System (INIS)

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

318

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

International Nuclear Information System (INIS)

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

319

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

International Nuclear Information System (INIS)

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

320

Biological effects of 131I and 125I isotopes of iodine in the rat.  

Science.gov (United States)

From the differences in radiation profiles between 131I and 125I isotopes of iodine it would be expected that they would show different effects on thyroid function. The differences should lead to lower rates of thyroid gland destruction with 125I and hence less post-irradiation hypothyroidism. This difference in biological effect has been demonstrated in rats by indirect assessment of thyroid function. In this report the long-term effects of a range of similar doses of 131I and 125I were compared, in male and female rats, by direct assessment of thyroid function. Seventeen months after receiving 25 and 125 muCi of 131I, male and female rats showed significant elevation of serum TSH concentration and a reduction in 3 h radioiodine uptake. Rats receiving 1 and 5 muCi of 131I and all doses of 125I showed no significant changes in thyroid function. These findings confirm the previously reported differences in effect between the 131I and 125I isotopes of iodine in the rat. PMID:978110

Doniach, I; Shale, D J

1976-10-01

 
 
 
 
321

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

322

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

International Nuclear Information System (INIS)

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

323

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

324

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

International Nuclear Information System (INIS)

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

325

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)

326

Coincidence sum peak assay of 125I activity using solid-state detectors  

International Nuclear Information System (INIS)

The use of solid-state detectors in the coincidence sum peak technique of 125I activity assay has been studied. The improved energy resolution of these detectors allows distinct resolution of the K?, K?, and ? peaks, and four sum peaks resulting from the coincident detection of the different X and ? photons. Theoretical considerations yield three separate equations, each of which can be used, in conjunction with the experimental sum peak spectrum, to give the activity of the 125I sample in question. This method is suitable for calibration of 125I activities in the range of 0.01--0.5 ?Ci (1 Ci=3.7 x 1010 Bq) with precisions of 2%--3%

327

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.

328

Distribution and disappearance of exogenous (/sup 125/I) big renin in the newborn puppy  

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The distribution and metabolism of infused exogenous (/sup 125/I) inactive plasma big renin, molecular weight 56,000 was studied in five newborn puppies. The animals were sacrificed and the organs removed and studied by chromatography, along with periodic blood samples taken during the 120-min study, for evidence of conversion of high-molecular-weight renin to low-molecular-weight renin. The decay curve suggested an initial rapid distribution (alpha) phase followed by a slower elimination (beta) phase. The liver, kidneys, and lungs had the highest % of (/sup 125/I)-big renin at the termination of the study. There was no chromatographic evidence of a change in molecular weight of the (125I)-big renin. These data show that big renin has a two-compartment disappearance curve and that there is no evidence of conversion of high-molecular-weight renin to low-molecular-weight renin systemically or in the tissues of the newborn canine puppy.

Siegel, S.R.; Parkhill, T.

1983-05-01

329

Radiolabelling and assay of Chinese agkistrodon acutus venom with carrier-free Na 125I  

International Nuclear Information System (INIS)

Chinese agkistrodon acutus venom (CAAV) was radiolabelled with carrier-free Na125I by the method of Iodogen. The specific activity and radiochemical purity for radiolabelled products were 4236.5 x 1010 Bq/mmol and 98%, respectively. Each CAAV molecule carried 0.52 125I atom. Physical and chemical characterization of radiolabelled CAAV was similar to unradiolabelled CAAV. Binding analysis showed that 125I-CAAV was bound to platelet in a saturable manner. Binding sites per platelet were 13255 +-6292/platelet. The dissociation constant (Kd) was 3.2 +- 0.69 x 10-10 mol/L. These results are similar to binding sites of other snake venom on platelet. The investigation showed that radiolabelled CAAV made by our laboratory was useful for radioligand binding assay

330

Experimental study of the dose distribution of 125I seeds sources brachytherapy prostate cancer  

International Nuclear Information System (INIS)

Objective: To study the dose distribution of 125I seeds in interstitial brachytherapy prostate cancer. Methods: Tumour phantom (?50 x 15 mm) was used by employing. 3-D the treatment planning system (3-D TPS) in the experiment simulation. Dose distribution of prostate cancer was determined in tumor phantom using thermoluminescence dosimetry method (TLD). Results: The experimental results indicated that dose distribution wa nonuniform. The authors find the dose distributions of prostate cancer was relied with geometric configuration and the number of 125I seeds. Conclusion: The dose of 125I seed source over the surface is the highest which attenuated very rapidly with distance. The narrower the interstitial space of seeds, the higher the dose in the cancer. (authors)

331

Optimized method for measuring cyclosporin A with 125I-labeled cyclosporin  

International Nuclear Information System (INIS)

We evaluated the use of the new iodinated ligand for the in vitro measurement of cyclosporin A by radioimmunoassay (RIA). Substitution of the iodinated cyclosporin (125I-CyA) for the corresponding tritium-labeled analog (3H-CyA) considerably simplifies and accelerates the currently available RIA, and improves its precision. Analysis of the respective dose-response curves showed that the 50% B0 value was lower for the 125I-CyA assay than for the 3H-CyA assay (37 vs 77 micrograms/L). Use of whole-blood specimens minimized interferences from temperature and hematocrit. We conclude that the use of 125I-CyA in a commercially available RIA for whole-blood specimens is accessible to most laboratories and provides rapid, reproducible data for management of transplant patients

332

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.)

333

Preparations of ginsenoside Rg1 immnogen and125I-labeled antigen  

International Nuclear Information System (INIS)

This work began with the side chain of ginsenoside Rg1 which was acetylized with Ac2O-Pyr and oxidized by OsO4 and NaIO4 to give ginsenoside Rg1 aldehyde, which was further converted into an unsaturated ester by Wittig-Horner reaction. The unsaturated ester was teated with N2H4 and HNO2 to yield Rg1 azide which was directly conjugated with BSA to give immunogen: ginsenoside Rg1BSA conjugate. This azide was conjugated with tyramine to give ginsenoside Rg1 tyramine conjugate which was labelled with free Na125I by CH-T to yield 125I-labeled antigen: ginsenoside Rg1-125I-tyramin. The labelling rate was 40%-50% and specific activity was 1.0-4.0MBq/?g. (author). 6 refs

334

Double-strand breaks from 125I incorporated in the DNA and cell death  

International Nuclear Information System (INIS)

Track structure calculations of the local energy deposition by electrons emitted during the decay of 125I are used to demonstrate that the range of high energy deposition is small (125I is incorporated into the DNA of synchronized CHO cells during a pulse and decays are allowed to accumulate a given time after the incorporation is described. Here it is shown that damage from 125I decays in newly replicated DNA (cells frozen for decay accumulation within 1 h after labelling) are relatively non-toxic whereas decays in mature DNA (cells frozen 5 h after labelling) are highly lethal. It is suggested that during DNA maturation the labelled DNA becomes associated with (or reorganized into) a radiosensitive nuclear structure and that damage to this structure is the primary cause of radiation-induced cell death. (Author)

335

Variation in 125I-insulin absorption and blood glucose concentration  

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The absorption of monocomponent porcine 125I-insulin Monotard and Isophane was studied in six insulin dependent diabetic patients over a period of 12 days. The absorption of insulin was measured as the disappearance of radioactivity from sites of injection. The daily 125I-insulin doses ranged from 20 to 48 IU between patients. The insulin absorbed varied considerably within and between patients. The range of individual daily absorbed insulin varied from 19 to 104 per cent of the 125I-insulin dose. A significant correlation (p less than 0.05) was found between insulin absorption and blood glucose concentration. Insulin absorption rates were relatively high before all hypoglycaemic episodes and reactive hyperglycaemia was only observed when relatively low insulin absorption rates followed the hypoglycaemic attack. The results show that lability in some insulin dependent diabetics is explained by variation in insulin absorption.

Lauritzen, Torsten; Faber, O K

1979-01-01

336

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

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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 res. 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)

337

Biological toxicity of /sup 125/I as a function of time after incorporation into DNA  

International Nuclear Information System (INIS)

Chinese hamster ovary (CHO) cells were synchronized by mitotic selection, plated on Falcon plastic 25-cm/sup 2/ T-flasks and resynchronized at the beginning of the S phase by an 8-hour treatment with aphidicolin (5 ?g/ml). Thirty minutes after release from the aphidicolin block, the cell were subjected to a 10 min labelling pulse with /sup 125/I-iododeoxyuridine, followed by harvesting of cell samples at time intervals ranging from 0 to 10 hrs after labeling. The labeled cells were then stored for various time periods at -950C for accumulation of /sup 125/I decays, and the viability of the cells was evaluated by standard colony assay. Cells harvested and frozen immediately after labeling were very resistant to /sup 125/I decays, exhibiting a D/sub o/ of --330 /sup 125/I decays/cell. Cells harvested at longer time intervals after labeling exhibited gradually increasing sensitivity to /sup 125/I decays until a constant D/sub o/ of about 70 decays/cell was reached for cells harvested 4 hrs after pulse labeling or later. Two alternate interpretations for these findings can be envisioned: a) If nucleoprotein is assumed to be the sole target for radiation death, the results indicate that DNA maturation increases the radiosensitivity of nucleoprotein; b) If radiation death involves a second target, the findings would suggest that /sup 125/I decays reach full toxic potential only after transfer of the labeled DNA segments from the replication site to the site of trom the replication site to the site of the second target

338

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

339

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 ron 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

340

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

International Nuclear Information System (INIS)

Bovine copper/zink superoxide dismutase (SOD) was labelled with 125I using the chloramine-T method. The tissue distribution of 125I-SOD (dose of SOD 5 mg/kg) was studied with whole-body and microautoradiography at various times after an intravenous injection. The distribution of 125I-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 125I-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 125I-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 125I-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) tendt 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 125I-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 125I-SOD by tubular cells and suggesting ''retention'' by the kidney of at least some of the enzyme and/or its end products. (author)

 
 
 
 
341

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

342

The effect of [125I]thyroglobulin tracer heterogeneity on serum Tg RIA measurement  

International Nuclear Information System (INIS)

Comparative serum thyroglobulin radioimmunoassay (Tg RIA) studies were used to evaluate the contamination of 125I-19S Tg (B) (670,000 Da) with a smaller partially immunoactive degradation product (C) (530,000 Da). Contamination of 125I-19S Tg (B) by its breakdown product C, has potential to lower absolute serum Tg values and produce non-parallelism in diluted high Tg sera which results in aberrantly low Tg RIA values. This problem potentially limits the clinical application and relevance of serum Tg measurements in thyroid cancer patients, especially those with metastases associated with high serum Tg levels. (Auth.)

343

Automated seed detection and three-dimensional reconstruction. II. Reconstruction of permanent prostate implants using simulated annealing  

International Nuclear Information System (INIS)

We present an algorithm, based on simulated annealing, for automatic seed matching and three-dimensional spatial coordinate reconstruction using either three radiographic films or three fluoroscopic images taken from different perspectives. The matching problem is defined in the framework of combinatorial optimization, which allows robust reconstruction in presence of calibration imprecision, patient movements, and isometric distortions. Furthermore, by using a global criterion to select the correct matching, we evade common problems of the three-film method and its variants in presence of noise. The algorithm has been tested on 112 clinical cases and 100 simulated implants and used clinically on more than 100 cases. Simulated implants were reconstructed with an average error of 0.21 mm. For clinical cases, comparison of the precision is performed between results obtained with this new method and results obtained using the three-film technique. Compared to the latter technique, the reconstruction precision was improved in 62% of the clinical cases

344

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

345

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

346

Reduction of in vivo deiodination of radioiodinated antibodies using N-Succinimidyl-4-[125i]iodobenzoate  

International Nuclear Information System (INIS)

Human nonspecific polyclonal IgG was labeled with 125I through direct and indirect labeling methods using chloramin-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 inflammatory area, results showed decreased thyroid and stomach activity and improved inflammatory thigh-to-normal tissue ratios with indirect labeling method (125I-IB-IgG) compared with direct labeling method (125I-IgG), indicating reduced in vivo deiodination. Results demonstrate that the 125I-SIB is probably the preferable approach for labeling antibodies with iodine radioisotopes

347

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

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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 T/sub 1/, T/sub 2/, early T/sub 3/ and pN/sub 0-1/, in case of microscopic lymph node manifestation without capsular perforation also into patients of stage pN/sub 2/ and pN/sub 4/. 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 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.

Thiel, H.J.; Mueller, R.; Schrott, K.M.

1987-03-01

348

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.)

349

Study of a hydrophobic site on bovine alpha-lactalbumin by labeling with (125I)-TID  

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The hydrophobic, photoreactive probe 3-(trifluoromethyl)-3-(m-(/sup 125/I)iodophenyl) diazirine ((/sup 125/I)TID) labels apo-bovine alpha-lactalbumin but much less his Ca2+-form. The labeling of the apo-form is strong at protein concentrations of 0.5 mg ml-1 and increases with increasing concentration. Furthermore, increasing concentrations of NaCl, decrease the labeling of apo-alpha-lactalbumin with (/sup 125/I)TID.

Van Ceunebroeck, J.C.; Krebs, J.; Hanssens, I.; Van Cauwelaert, F.

1986-07-31

350

Study of a hydrophobic site on bovine alpha-lactalbumin by labeling with [125I]-TID  

International Nuclear Information System (INIS)

The hydrophobic, photoreactive probe 3-(trifluoromethyl)-3-(m-[125I]iodophenyl) diazirine ([125I]TID) labels apo-bovine alpha-lactalbumin but much less his Ca2+-form. The labeling of the apo-form is strong at protein concentrations of 0.5 mg ml-1 and increases with increasing concentration. Furthermore, increasing concentrations of NaCl, decrease the labeling of apo-alpha-lactalbumin with [125I]TID

351

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)

352

Results of the in vivo application of /sup 125/I-labelled Pasteurella multocida antigens  

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In in vivo experiments iodine was separated rapidly from /sup 125/I-labelled Pasteurella multocida germs. By means of direct radioactivity measurement as well as by autoradiography could be demonstrated that the iodine was enriched in the thyroid following application of labelled antigen to mice.

Flossmann, K.D.; Heilmann, P.; Mueller, G. (Akademie der Landwirtschaftswissenschaften der DDR, Jena. Inst. fuer Bakterielle Tierseuchenforschung)

1981-09-01

353

Results of the in vivo application of 125I-labelled Pasteurella multocida antigens  

International Nuclear Information System (INIS)

In in vivo experiments iodine was separated rapidly from 125I-labelled Pasteurella multocida germs. By means of direct radioactivity measurement as well as by autoradiography could be demonstrated that the iodine was enriched in the thyroid following application of labelled antigen to mice

354

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

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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

355

Stability of 125I label after intragastric or intravenous administration of radioiodinated latexes to mice  

International Nuclear Information System (INIS)

The stability of 125I tracer bound to styrene-butadiene copolymer latexes was determined by administering the latexes intragastrically or i.v. to mice. Some of the latexes had been given an additional coating of polystyrene after iodination. Latex particle sizes were 0.17 to 0.25 ?m; coatings were 0.01 to 0.02 ?m. 125I found in the urine after latex administration was not bound to latex particles and was used as a measure of deiodination. Styrene: butadiene ratios used for latex preparation and percent of administered radioactivity recovered in the urine one day after intragastric administration were as follows: (a) 95:5 uncoated latex, 32.8%; (b) 84:16 uncoated latex, 56.3%; (c) 84:16 coated latex, 27.0%; (d) 60:40 uncoated latex, 14.0%; (e) 60:40 coated latex, 8.9%. Following i.v. administration of latexes, similar amounts of 125I were excreted in the urine during the first day. The remainder of i.v. administered radioactivity was retained in the liver with only slight loss in 5 days. Because of the instability of the label, radioiodinated latexes could not be used to quantitate latex absorption by the intestine; however, the data indicate that a small fraction (125I loss from radioiodinated styrene-butadiene copolymer latexes is inevitable because of the lability of the C-itable because of the lability of the C-I chemical bond

356

Myocardial uptake of 125I-BMIPP in rats treated with adriamycin  

International Nuclear Information System (INIS)

The ability of 125I-BMIPP in assessing myocardial mitochondrial function was investigated in rats treated with adriamycin (ADR). Intraperitoneal administration of ADR (4 mg/kg) for 6 days significantly decreased a ratio of heart/body weight as compared with the control rats. The light and electron microscopic analysis showed that ADR produced histological damages mainly in the mitochondria with minimal changes in the myofibril and nucleus. In the study of mitochondrial respiratory function, oxygen consumption with adding ADP, respiratory control ratio and ADP/O ratio were significantly lower in ADR rats than control rats. While myocardial uptake of 201TlCl was not different between the two groups, the uptake of 125I-BMIPP corrected by blood counts was significantly reduced in ADR rats (3.1±0.4 vs. 2.3±0.8, p125I-BMIPP. The observation suggests that 125I-BMIPP myocardial scintigraphy could be a useful method for determining mitochondrial function in patients with myocardial diseases. (author)

357

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)

358

Identification and subclassification of rat adipocyte ?-adrenoceptors using (+-)-[125I]cyanopindolol  

International Nuclear Information System (INIS)

The ligand binding characteristics of ?-adrenoceptors on membranes derived from rat whole fat pads and isolated adipocytes have been compared to those present on lung membranes using the specific ligand (+-)-[125I]cyanopindolol ([125I]CYP). The equilibrium dissociation constant (Ksub(D)) of [125I]CYP was similar in all three preparations, whilst the degree of stereospecificity displayed by the isomers of propranolol varied between lung and isolated adipocyte membranes. The rank order of potency in displacing [125I]CYP binding was isoprenaline > adrenaline > noradrenaline in lung and whole fat pads, suggesting an overall ?2-receptor subtype, and isoprenaline > noradrenaline > adrenaline in isolated adipocytes, suggesting a ?1-receptor. In view of the high proportion of ?2-receptors on whole fat pad membranes, the overall amount of ?2-receptors on isolated adipocytes may reflect contamination from other cell types. The nature of the ?1-receptors present on fat cells is discussed in relation to the apparently atypical ?-receptor involved in mediating functional lipolytic response. (Auth.)

359

Identification and subclassification of rat adipocyte. beta. -adrenoceptors using (+-)-(/sup 125/I)cyanopindolol  

Energy Technology Data Exchange (ETDEWEB)

The ligand binding characteristics of ..beta..-adrenoceptors on membranes derived from rat whole fat pads and isolated adipocytes have been compare