125I Implantation Research Articles

Radioactive seed 125I implantation in treating recurrence and metastasis after liver transplantation in hepatoma

To investigate the clinical value of CT-guided radioactive seed (125)I implantation in treating recurrence and metastasis after liver transplantation in hepatoma. Eleven patients with recurrence and metastasis after liver transplantation for hepatoma, with 45 metastatic lesions, 2.5 cm in diameter on average totally 9 males and 2 females, aged 56 (35 approximately 68), underwent CT-guided radioactive seed 125I implantation for 33 man-times. 125I seeds of the radioactivity of 30 MBq at a distance of 0.5 approximately 1.0 cm were implanted into the recurrence and metastasis lesions according to TPS system before the operation. The matched peripheral dosage (MPD) was 100 approximately 150 Gy, and the number of radioactive seeds for one patient ranged 10 approximately 100. Among the 45 lesions, 17 obtained CR, 20 PR, 7 NC, and 1 PD. The response rate was 82.2%. Side effects occurred during the procedure including pneumothorax in 1 cases with the lung compressed less than 30 percent, bleeding in 3 cases, and blood in sputum and defervescence in 5 cases. Seeds migration 2 months after the operation occurred in 2 cases. WBC decreased slightly in 2 cases 2 weeks after the operation, with the WBC count >or= 3 x 10(9)/L. No other severe complications, such as massive hemorrhage, bile fistulae, and pancreatic fistula were seen. CT guided radioactive seed 125I implantation procedure has good clinical effects with minimal damage and few complications in treating recurrence and metastasis after liver transplantation in hepatoma.

Intraoperative permanent implantation of radioactive I-125 seed for local advanced non small lung cancer

Objective To study the clinical efficacy and methods of permanent implantation of radioactive I-125 seed in surgery for local advanced non small lung cancer (LANSCLC).

Nursing about 56 patients with prostatic carcinoma when cured by 125I implantation forever

前列腺癌是中老年男性生殖泌尿系统常见的恶性肿瘤.我国前列腺癌的发病率与欧美比较相对较低,但呈逐渐上升趋势[1].前列腺癌近距离治疗是一种新型手术方式,与传统的前列腺癌的治疗方法相比,它具有创伤小、出血少、疗效好等优点.2003年12月-2005年1月,我院开展碘间质植入近距离治疗前列腺癌56例,收到了满意的效果,现报道如下。

1005: Quality of Life After Monotherapy Treatment for Localized Prostate Cancer: Implant (I-125), Radical Prostatectomy, and High Dose External Beam Radiation Therapy

The purpose of this study is to assess health related quality of life (HRQOL) in patients treated for localized prostate cancer by a monotherapy approach with permanent brachytherapy I-125 implant (IMP), high dose external beam radiation therapy (HDRT), or radical prostatectomy (RP).

2258: Development of Acute and Late Rectal Toxicities Following I-125 Implantation for Prostate Cancer

2258: Development of Acute and Late Rectal Toxicities Following I-125 Implantation for Prostate Cancer

Low-dose rate prostate brachytherapy is well tolerated in patients with a history of inflammatory bowel disease

We report on the follow-up of 24 patients with a prior history of inflammatory bowel disease (IBD) treated with brachytherapy for early-stage prostate cancer. Twenty-four patients with a history of inflammatory bowel disease (17 with ulcerative colitis (UC), 7 with Crohn's disease [CD]) underwent prostate brachytherapy between 1992 and 2004. Fifteen patients were treated with I-125 implantation and 6 patients were treated with Pd-103 alone or in combination with 45 Gy external beam radiation. Charts were reviewed for all patients, and all living patients were contacted by phone. National Cancer Institute common toxicity scores for proctitis were assigned to all patients. Actuarial risk of late toxicity was calculated by the Kaplan-Meier method. Statistical analysis was performed using SPSS software. Follow-up ranged from 3 to 126 months (median, 48.5 months; mean, 56.8 months). None of the patients experienced Grade 3 or 4 rectal toxicity. Four patients experienced Grade 2 late rectal toxicity. The 5-year actuarial freedom from developing late Grade 2 rectal toxicity was 81%. At a median follow-up of 48.5 months, 23 patients were alive and had no evidence of disease with a median prostate-specific antigen for the sample of 0.1 ng/mL (range, <0.05-0.88 ng/mL). One patient died of other causes unrelated to his prostate cancer. Prostate brachytherapy is well tolerated in patients with a history of controlled IBD. Therefore, brachytherapy should be considered a viable therapeutic option in this patient population.

Treatment of unresectable advanced gastric cancer using lodine-125 brachytherapy

OBJECTIVE The purpose of the study was to examine the efficacy of treating patients with advanced gastric cancer using iodine - 125 (125I) brachytherapy. METHODS Ten patients with unresectable advanced gastric cancer were selected based on their pattern of CT scans. We utilized a brachytherapy planning system to determine the distribution of the 125I seeds, their activity and quantity. The matched peripheral dose (MPD) was 110–135 Gy. 125I seeds were implanted in a single plane or biplane by an intraoperative small incision or percutaneous puncture. The postoperative hemogram, CT, KPS, pain-relieving period and survival period were recorded. RESULTS One patient developed a complete response (CR), 4 patients a partial response (PR), 3 patients showed no change (NC) and 2 patients developed progressive disease (PD). The overall response rate (CR+PR) was 50% (5/10). The pain-relieving rate was 89% (8/9). The patients’ appetite and KPS were improved. The longest survival period was 10 months and median life span was 4 months. There were 8 patients whose seeds fell off resulting in an expulsion rate of 3.8% (26/692). The patients showed 0–1 degree acute radio-therapeutic side-effects without other symptoms such as abdominal pain, vomitus cruentes or intestinal obstruction etc. CONCLUSION Applying 125I implantation to treat advanced gastric cancer with a reasonable seed distribution can significantly improve clinical symptoms and their quality of life. The radioactive damage is mild. This method can be used as an important supplementary treatment for unresectable advanced gastric cancer.

Examination of dosimetry accuracy as a function of seed detection rate in permanent prostate brachytherapy

The variation of permanent prostate brachytherapy dosimetry as a function of seed detection rates was investigated for I125 implants with seed activities commonly employed in contemporary practice. Post-implant imaging and radiation dosimetry data from nine patients who underwent PPB served as the basis of this simulation study. One-thousand random configurations of detected seeds were generated for each patient dataset using various seed detection levels from 30% to 99%. Dose parameters, including D90, were computed for each configuration and compared with the actual dosimetry data. A total of 108 000 complete sets of post-PPB dose volume statistics were computed. The results demonstrated that although the average D90 differed from the true value by less than 5% when 70% or more seeds were identified, the D90 of an individual case could deviate up to 13%. The 95% confidence interval (CI) of estimated D90 values differ by less than 5% from the actual value when 95% or more seeds are detected, or approximately a 7 Gy difference in the D90 value for a prescription dose of 144 Gy. Estimated target volume dose parameters tended to decrease with reduced seed detection rates. The most variable dose parameter was the prostate V100 in absolute scale while the urethral V100 was most variable in a relative sense. Based on this comprehensive simulation study, it is suggested that 95% or more seeds need to be localized in order to provide an accurate estimation of dose parameters for contemporary iodine 125 permanent prostate brachytherapy.

Reduction of pulmonary migration of permanent interstitial sources in patients undergoing prostate brachytherapy

Objectives To investigate a method to decrease the problem of seed migration after permanent prostate brachytherapy. Permanent prostate brachytherapy can be performed by a number of techniques using several different seed configurations. All have been associated with some degree of pulmonary seed migration, and no studies have clearly investigated a means of decreasing this problem. Methods A total of 238 patients underwent implantation with either iodine-125 (I-125; 146 patients) or palladium-103 (92 patients). The implant was performed in real time using an applicator, with the sources placed just underneath the prostatic capsule. Postimplant dosimetry was performed at 1 month. Routine chest x-ray was obtained a minimum of 4 months after implantation; 24 patients had a second chest x-ray taken. Results A total of 21,654 seeds were implanted (median 89, range 27 to 220). Postimplant chest x-rays were obtained at a median of 912 days (range 147 to 3023), and 4 patients (1.7%) experienced at least one seed embolus to the lung. Of the 21,654 seeds, 10 (0.005%) were found in the lungs. All 4 patients had received an I-125 implant, resulting in a pulmonary embolus rate for I-125 of 2.7% (4 of 146) and for palladium-103 of 0% (0 of 92). No patients experienced subsequent seed migration if it was not seen on the initial film. The median dose delivered to 90% of the prostate volume for all patients undergoing I-125 implantation was 172 Gy and for the 4 patients with seed migration it was 174 Gy. Conclusions Seed embolism to the lungs is a rare event when patients undergo implantation using the real-time method. Although in our series migration was slightly greater with I-125 than with palladium-103, no negative effect was seen on the postimplant dosimetry results.

81 Transperineal I-125 implants for early prostate cancer: Rambam Medical Center, Israel

81 Transperineal I-125 implants for early prostate cancer: Rambam Medical Center, Israel

THYROID UPTAKE OF 125IODINE AFTER PROSTATE PERMANENT BRACHYTHERAPY

To decrease the seed migration rate after 125I prostate brachytherapy and improve the quality of implants to our knowledge we report for the first time the detection of thyroid uptake, possibly from a damaged seed, in a patient after 125I implantation. Seed migration detection is routinely offered to our patients at the post-evaluation visit. A seed migration detector and comprehensive investigation procedure have been developed for the task. Chest radiographs are ordered to document the location of the detected seed. A fluoroscopic study may be performed if intracardiac radioactivity is detected. Since November 2001, 246 patients have been studied for seed migration. A total of 23,184 125I seeds were implanted, of which 75 were lost through the urethra and 25 migrated to the thorax. In the routine survey of a patient on February 13, 2003 radioactivity in the chest-neck region was sensed. Repeat radiographs and fluoroscopic examinations were negative for seed migration. Using a gamma camera butterfly-shaped uptake was noted in the thyroid region. The energy peak of the uptake matched the spectrum of the 125I source. The patient denied any intake of other iodine medication. The results suggested possible 125I leakage from at least 1 seed implanted in the prostatic region. Improved control of seed migration has been achieved. The detection of thyroid uptake is reported. Detection techniques and subsequent actions are described.

541 poster Transperineal I-125 implants for early prostate cancer: first results of Rambam Medical Center

541 poster Transperineal I-125 implants for early prostate cancer: first results of Rambam Medical Center

The impact of technological advances on the evolution of 3D conformal brachytherapy for early prostate cancer.

Permanent implantation of I-125 and Pd-103 seeds is one of the widely used treatment options for the early stage prostate cancer with minimum normal tissue complications and long-term local control of the tumor. This is possible because of several technological advances made in the past decade to better understand the procedural aspects of implantations with the desired clinical outcome and with acceptable morbidities. In addition, with the widespread use of PSA testing, more widely disseminated information about prostate cancer and increased patient awareness, over 70% of patients are diagnosed early with localized disease and therefore are candidates for definitive local therapy. Delineation of soft tissue structures including the prostate, rectum, urethra and bladder has become more accurate with the use of imaging modalities including Ultrasound and MRI, with or without the CT. A re-evaluation of the dosimetric parameters of the radioactive sources has lead to a more precise estimate of the dose delivered to the prostate and the associated critical normal structures. Technological improvements in the post implant dosimetry have helped to understand the factors, which makes an implant a "good implant" or a "poor implant". Intraoperative treatment planning with on line dosimetry is emerging as one of the best approaches for prostate brachytherapy. In addition, better software is now available producing dose-volume histograms with 3D target and normal tissue reconstruction. The combination of seed implant followed by IMRT would provide scope for differentially boosting the regions under-dosed because of uncontrollable and unexpected reasons during the implant and unsuspected micro extensions of the tumor.

108 oral Effect of multiple variables on acute urinary morbidity following permanent I-125 implantation of the prostate: insights from a prospective, randomized trial

108 oral Effect of multiple variables on acute urinary morbidity following permanent I-125 implantation of the prostate: insights from a prospective, randomized trial

Assessment of radiation safety instructions to patients based on measured dose rates following prostate brachytherapy

Purpose To validate radiation safety instructions to patients and to evaluate the potential radiation doses to members of the public after 125I or 103Pd prostate implantation. Methods and materials Radiation dose rate measurements were made in the immediate postoperative period on 636 consecutive patients with stage T1-T2 prostate cancer who underwent transperineal 125I or 103Pd implantation at Memorial Sloan-Kettering Cancer Center during the period from August 1995 through January 2003. Results The mean radiation dose rate at the anterior skin surface following a prostate implant was 37 μSv/hr for 125I and 8 μSv/hr for 103Pd. At 30 cm from the anterior skin surface, these dose rates were reduced to 6 μSv/hr for 125I and 3 μSv/hr for 103Pd. At 1 m from the anterior skin surface the dose rates from both types of implants were reduced to less than 1 μSv/hr. The effect of body weight on dose rates from 125I sources was examined for a select sub-group of patients and the measured dose rate was found to decrease with increasing body weight. In another group of patients, dose rate measurements were made on both lateral skin surfaces and were less than 16.8 μSv/hr in all cases. Assuming a 33% occupancy factor and utilizing the mean measured dose rate for 125I, the time required to reach an effective dose equivalent limit of 5 mSv for caregivers was estimated to be 19 days on contact with the skin surface. Using a similar calculation, the lifetime doses for 125I at a distance of 30 cm from the anterior skin surface, as well as the lifetime doses for 103Pd on contact with the skin surface and at 30 cm from the anterior skin surface can be shown to be less than 5 mSv. Conclusions The large number of cases available for this study permits a validation of radiation safety recommendations and provides concrete information from which the permitted exposure times following implantation can be estimated. The data support the conclusion that patients treated with these implants do not represent a radiation risk to members of the public.

Selective identification of different brachytherapy sources, ferromagnetic seeds, and fiducials in the prostate using an automated seed sorting algorithm

Purpose Routine permanent prostate brachytherapy (PPB) includes CT-based postimplant dosimetry (PID). A method of identifying different source types from CT data in the same implant volume is described. Methods and materials A previously described automatic method for seed localization using CT data is used in this study. Two cases were analyzed: a PPB case with 103Pd followed by salvage 125I implantation, both performed at another institution, and a cadaver case where 4 different seed types, including ferromagnetic seeds, and fiducials were implanted. Results Automatic segregation of different seed types with minimal manual correction is demonstrated using the described localization algorithm. The process is confirmed accurate by comparison of plain film radiographs to CT data and digitally reconstructed radiographs. Conclusion Unique identification of different source types, including PPB seeds, fiducial markers, and ferromagnetic seeds in permanent implants is possible and permits dosimetric analyses that are spatially coincident.

Influence of prostate volume on dosimetry results in real-time 125I seed implantation

Purpose Achieving a minimal dose of 140 Gy to 90% of the prostate (D 90) on postimplant dosimetry has been shown to yield improved biochemical control by 125I brachytherapy, and a D 90 >180 Gy can be associated with increased long-term toxicity of seed implantation. Significant enlargement of the prostate on postimplant CT compared with the ultrasound (US) volume at implantation (CT/US ratio) has been associated with lower dose results, but other factors predicting for high or low doses are not well established. We determined whether the prostate size at implantation influenced the CT/US ratio results affecting postimplant dosimetry or predicted for D 90 values <140 or >180 Gy in patients implanted with 125I in a community hospital setting. Methods and materials The dosimetry results from 501 patients from 33 community hospitals were analyzed after full dose 125I implantation. Implant radioactivity was obtained from reference tables relating millicuries to prostate volume (PV). Seeds were placed under real-time US guidance with peripheral weighting in a uniform method for all prostate sizes. CT-based dosimetry was performed 1 month after implantation. Dose–volume histogram parameters were analyzed for volume effects, including D 90, the dose to 10% and 30% of the rectal wall, and the dose to 30% of the urethra and bladder. The PV was defined as small (<25 cm 3), medium (25 to <40 cm 3), or large (≥40 cm 3). Results The PV ranged from 9 to 79 cm 3 (median 32.7). A D 90 ≥140 Gy was achieved in 452 patients (90%). The median D 90 was 164 Gy (range 90–230) and increased from 149.5 Gy in small prostates to 164 Gy in medium ( p <0.001) and 176 Gy in large ( p <0.001) prostates. A D 90 <140 Gy occurred in 20% of small vs. 9% of medium and 3% of large prostates ( p = 0.003). A D 90 >180 Gy occurred in 7% of small and 10% of medium vs. 25% of large glands ( p <0.001). The rectal dose increased significantly with an enlarging PV. The bladder and urethral doses increased from the small to medium PVs, although did not increase further in the large glands. The median CT/US ratios showed a significant volume relationship, decreasing with enlarging PVs, but were not associated with a D 90 <140 or >140 Gy. The D 90 results for <140 Gy and >140 Gy occurred at equal activities per volume. Conclusion Ninety percent of patients implanted by community-level practitioners using reference tables and real-time US-guided implantation achieved a D 90 outcome of ≥140 Gy. Significant differences in dose outcomes <140 Gy and >180 Gy occurred related to PV. Those with prostates <25 cm 3 had a 20% frequency of D 90 <140 Gy, unrelated to excessive postimplant volume enlargement or insufficient activity per reference table, suggesting that the activity-to-volume recommendations may not allow for much variance in final seed position. Such seed displacement may contribute to lower doses, most commonly in small glands. One may consider increasing the activity implanted in small prostates, because a D 90 >180 Gy occurred in only 7% of these cases. Patients with glands >40 cm 3 were 25% likely to have a D 90 result >180 Gy and were at only 3% risk of a D 90 <140 Gy. These patients may benefit from intraoperative dosimetry or a reduction in implant activity.

The Brain Tumor Cooperative Group NIH Trial 87-01: A Randomized Comparison of Surgery, External Radiotherapy, and Carmustine versus Surgery, Interstitial Radiotherapy Boost, External Radiation Therapy, and Carmustine

Abstract OBJECTIVE The objective of the Brain Tumor Cooperative Group NIH Trial 87-01 trial was to investigate the effect of additional implanted radiation therapy in newly diagnosed patients with pathologically confirmed malignant gliomas. METHODS The study involved a randomized comparison of surgery, external beam radiotherapy, and carmustine (BCNU) versus surgery, external beam therapy, interstitial radiotherapy boost, and BCNU in newly diagnosed malignant gliomas. 125I was chosen as best suited for this effort because it allowed preimplantation planning and postimplantation quality assurance review. Two hundred ninety-nine patients met the eligibility criteria and were randomized into the two arms of the study between December 1987 and April 1994. Follow-up continued for an additional 3 years. Twenty-nine patients were identified as having committed protocol violations and were excluded, resulting in 270 subjects in the Valid Study Group. One hundred thirty-seven patients received external beam radiation and BCNU, and 133 underwent the 125I implantation plus external beam radiation and BCNU therapy. RESULTS The overall median survival for the Valid Study Group was 64.3 weeks. The median survival for patients receiving additional therapy of 125I was 68.1 weeks, and median survival for those receiving only external beam radiation and BCNU was 58.8 weeks. The cumulative proportion surviving between the two treatment groups was not statistically significantly different (log-rank test, P = 0.101). As in other studies in the literature, age, Karnofsky score, and pathology were predictors of mortality. Additional analyses incorporating an adjustment for these prognostic variables, either in a stratified analysis or Cox proportional hazards model, did not result in statistically significant differences in the cumulative proportion of patients surviving between the two treatment groups. CONCLUSION We conclude that there is no long-term survival advantage of increased radiation dose with 125I seeds in newly diagnosed glioma patients.

The Brain Tumor Cooperative Group NIH Trial 87-01: A Randomized Comparison of Surgery, External Radiotherapy, and Carmustine versus Surgery, Interstitial Radiotherapy Boost, External Radiation Therapy, and Carmustine

The objective of the Brain Tumor Cooperative Group NIH Trial 87-01 trial was to investigate the effect of additional implanted radiation therapy in newly diagnosed patients with pathologically confirmed malignant gliomas. The study involved a randomized comparison of surgery, external beam radiotherapy, and carmustine (BCNU) versus surgery, external beam therapy, interstitial radiotherapy boost, and BCNU in newly diagnosed malignant gliomas. (125)I was chosen as best suited for this effort because it allowed preimplantation planning and postimplantation quality assurance review. Two hundred ninety-nine patients met the eligibility criteria and were randomized into the two arms of the study between December 1987 and April 1994. Follow-up continued for an additional 3 years. Twenty-nine patients were identified as having committed protocol violations and were excluded, resulting in 270 subjects in the Valid Study Group. One hundred thirty-seven patients received external beam radiation and BCNU, and 133 underwent the (125)I implantation plus external beam radiation and BCNU therapy. The overall median survival for the Valid Study Group was 64.3 weeks. The median survival for patients receiving additional therapy of (125)I was 68.1 weeks, and median survival for those receiving only external beam radiation and BCNU was 58.8 weeks. The cumulative proportion surviving between the two treatment groups was not statistically significantly different (log-rank test, P = 0.101). As in other studies in the literature, age, Karnofsky score, and pathology were predictors of mortality. Additional analyses incorporating an adjustment for these prognostic variables, either in a stratified analysis or Cox proportional hazards model, did not result in statistically significant differences in the cumulative proportion of patients surviving between the two treatment groups. We conclude that there is no long-term survival advantage of increased radiation dose with (125)I seeds in newly diagnosed glioma patients.

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

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.