Brachytherapy with permanent seed implantation

The 45-month therapy outcomes of permanent seed implantation and radical prostatectomy for prostate cancer patients

Objective To compare the efficacy and safety-related outcomes after radical prostatectomy (RP) and permanent seed implantation (PI) using iodine-125 seeds in patients with prostate cancer. Method A retrospective analysis of 196 patients with biopsy-confirmed prostate cancer (T2-T3) was performed in this study. Forty-five patients who underwent PI using iodine-125 seeds combined with endocrine therapy or androgen deprivation therapy (ADT) were compared with 151 patients who underwent RP combined with endocrine therapy or adjuvant ADT. The efficacy and safety outcomes were compared using Kaplan–Meier curves and t-tests. Results Between the RP and PI treatment modalities, no significant difference (P > 0.05) in biochemical recurrence-free survival (BRFS) was observed using Kaplan–Meier curves, regardless of the combination of adjuvant treatment modalities. Furthermore, no significant differences were observed (P > 0.05) with respect to PSA fluctuations, albumin, leukocyte count, urinary and rectal symptoms, erectile function or quality of life (QoL) between the two therapy methods. However, significant differences in the maximum flow rate, average length of hospital stay and indwelling catheter time were observed between the two groups (P < 0.001). Conclusion Iodine-125 seed implantation significantly shortened the average length of hospital stay and indwelling catheter time compared with RP, and the haemoglobin level was significantly higher in the PI group than in the RP group; however, the maximum urine flow rate was lower after of PI than after RP. These two methods showed similar BRFS rates among prostate cancer patients.

Self-Expanding Anchors for Stabilizing Percutaneously Implanted Microdevices in Biological Tissues

Percutaneously implanted miniaturized devices such as fiducial markers, miniaturized sensors, and drug delivery devices have an important and expanding role in diagnosing and treating a variety of diseases. However, there is a need to develop and evaluate anchoring methods to ensure that these microdevices remain secure without dislodgement, as even minimal migration within tissues could result in loss of microdevice functionality or clinical complications. Here we describe two anchoring methods made from biocompatible materials: (1) a self-expanding nitinol mesh anchor and (2) self-expanding hydrogel particles contained within pliable netting. We integrate these anchors into existing drug-screening microdevices and experimentally measure forces required to dislodge them from varying tissues. We report similar dislodgement forces of 738 ± 37, 707 ± 40, 688 ± 29, and 520 ± 28 mN for nitinol-anchored microdevices, and 735 ± 98, 702 ± 46, 457 ± 47, and 459 ± 39 mN for hydrogel-anchored microdevices in liver, kidney, fat, and muscle tissues, respectively—significantly higher compared with 13 ± 2, 15 ± 3, 15 ± 2, and 15 ± 3 mN for non-anchored microdevices (p < 0.001 in all tissues). The anchoring methods increased resistance to dislodgement by a factor of 30–50× in all tissues, did not increase the required needle gauge for insertion, and were compatible with percutaneous implantation and removal. These results indicate that anchoring significantly improves microdevice stability and should reduce migration risk in a variety of biological tissues.

Feasibility and Clinical Value of CT-Guided 125I Brachytherapy for Pain Palliation in Patients With Breast Cancer and Bone Metastases After External Beam Radiotherapy Failure

Objectives: To evaluate the feasibility and clinical value of CT-guided iodine-125 (¹²⁵I) brachytherapy for pain palliation in patients with breast cancer and bone metastases after external beam radiotherapy failure. Methods: From January 2014 to July 2016, a total of 90 patients, who had received the standard therapies for bone metastases but still suffered moderate-to-severe pain, were retrospectively studied. About 42 patients were treated with both ¹²⁵I brachytherapy and bisphosphonates (Group A), and 48 patients were treated with bisphosphonates alone (Group B). Results: In Group A, 45 ¹²⁵I brachytherapy procedures were performed in 42 patients with 69 bone metastases; the primary success rate of ¹²⁵I seed implantation was 92.9%, without severe complications. Regarding pain progression of the two groups, Group A exhibited significant relief in "worst pain," "least pain," "average pain," and "present pain" 3-day after treatment and could achieve a 12-week-remission for "worst pain," "least pain," "average pain," and "present pain." The morphine-equivalent 24-h analgesic dose at 3 days, 4 weeks, 8 weeks, and 12 weeks was 91 ± 27, 53 ± 13, 31 ± 17, and 34 ± 12 mg for Group A, and 129 ± 21, 61 ± 16, 53 ± 15, and 105 ± 23 mg for Group B. Group A experienced a lower incidence of analgesic-related adverse events and better quality of life than Group B. Conclusion: The CT-guided ¹²⁵I brachytherapy is a feasible and an effective treatment for the palliation of pain caused by bone metastases from breast cancer after external beam radiotherapy failure.

Sub-Micrometer Au@PDA-125 I Particles as Theranostic Embolism Beads for Radiosensitization and SPECT/CT Monitoring

Au nanoparticles (3.8 ± 0.6 nm) are assembled to sub-micrometer Au particles (186.3 ± 20.4 nm) and covered with adhesive polydopamine (PDA) as embolism beads (198.8 ± 23.2 nm). Radioactive iodine-125 is labeled to Au@PDA to introduce the function of intra-irradiation. For the therapeutic effects of Au@PDA-¹²⁵ I, Au particles sensitize the radiation to MHCC97H hepatoma cells and tumor-bearing mice. At the cellular level, after being treated with a relatively low-dose (5 Gy) γ-ray, Au-sensitized radiotherapy (RT) leads to an immediate increase of intracellular reactive oxygen species, accompanying with an increase of cell apoptosis. Due to the intra-irradiation, self-healing of RT-leaded DNA double-strand breakage is suppressed, inducing a further increase of cell apoptosis after RT treatment. Likewise, 3 cycles of sensitized RT leads to a valid control of tumor volume growth, but Au@PDA-¹²⁵ I has no harm or radioactive residual on or in the radiosensitive organs, including the thyroid, heart, lungs, liver, and spleen. Additionally, photons emitted from ¹²⁵ I and high X-ray absorption of the Au element makes the beads suitable for single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Therefore, as theranostic embolism beads, Au@PDA-¹²⁵ I can both enhance the therapeutic effects of external RT, and provide a real-time SPECT/CT monitoring of therapeutic time window.

A comparative study on the efficacies of gonadotropin-releasing hormone (GnRH) agonist and GnRH antagonist in neoadjuvant androgen deprivation therapy combined with transperineal prostate brachytherapy for localized prostate cancer

Background

Neoadjuvant androgen deprivation therapy (ADT) has been suggested to confer several clinical benefits in patients with prostate cancer (PCa) undergoing transperineal prostate brachytherapy (TPPB). Unlike gonadotropin-releasing hormone (GnRH) receptor agonists, a GnRH antagonist such as degarelix can achieve castrate levels of testosterone without testosterone flare. However, normalization of serum testosterone levels following completion of neoadjuvant ADT in either form of treatment has never been compared in clinical trials.

Methods/Design

This is a single-center, open-label, randomized controlled study that will compare the efficacy and safety of degarelix with those of existing GnRH agonists combined with ¹²⁵I-TPPB. A total of 56 patients with low/intermediate-risk clinically localized PCa will be enrolled and randomized to one of two treatment groups: the GnRH agonist group and the degarelix group. Patients in the GnRH agonist group will receive leuprorelin acetate or goserelin acetate, and those in the degarelix group will receive the initial dose of 240 mg as 2 subcutaneous injections of 120 mg each, and then 80 mg of maintenance doses every 4 weeks for 12 weeks. Those randomly assigned to the 12-week intervention period will subsequently undergo 48-weeks of follow-up after ¹²⁵I-TPPB. The primary endpoint is defined as normalization of serum testosterone levels (>50 ng/dL) following completion of neoadjuvant ADT. All patients will be assessed every 4 weeks for the first 24 weeks, then every 12 weeks for the next 36 weeks after administrations of these drugs. Secondary endpoints are the proportion of normalized serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH), the percent reduction in prostate specific antigen (PSA) compared with pretreatment levels, the percent reduction in total prostate volume (TPV) during neoadjuvant ADT, the percent increase in TPV after ¹²⁵I-TPPB, the percent reduction in hemoglobin, serum alkaline phosphatase (ALP), changes in free testosterone and bone mineral content measurement, the proportion of patients who have serum testosterone levels over 50 ng/dL at 12 weeks following completion of neoadjuvant ADT, and the improvement of quality of life (QOL).

Discussion

The present study will provide additional insight regarding the benefit and potency of degarelix and will examine its potential as a new option for administration in neoadjuvant ADT.

Trial registration

Identification number: UMIN000015519.

Registration date: October 24, 2014.

Iodine 125 Seed for Localization in Primary Hyperparathyroidism

Background. Preoperative localization of the parathyroid gland prior to a minimally invasive parathyroidectomy (MIP) is important because of varying locations of the parathyroid gland. Several methods have been described to localize the affected gland. One novel technique is the use of an iodine 125 (I-125) seed as a marker. The aim of this study is to evaluate the feasibility of using an I-125 seed in localizing the diseased parathyroid gland prior to MIP. Materials and methods. This is a pilot study of 10 patients performed in the Amphia Hospital, the Netherlands. Patients in whom primary hyperparathyroidism (PHPT) was diagnosed in combination with 1 enlarged parathyroid gland on ultrasound (US) and scintigraphy and who were eligible for MIP were included in this study. These patients underwent a preoperative US-guided I-125 seed placement in the affected parathyroid gland. The main study parameters were the feasibility of the placement, intraoperative localization of the diseased gland and complications. Results. A total of 10 patients were included. The US-guided I-125 placement in the affected parathyroid gland was technically feasible in the majority of cases. Because of the anatomical location of the gland, the placement was difficult in 2 patients, resulting in suboptimal position and possible misplacement of the marker. MIP was uncomplicated in most cases. Complications during surgery were mainly intraoperative bleeding. Conclusions. The use of an I-125 seed for preoperative localization in PHPT is a relatively safe technique in parathyroid surgery. More research is needed to compare this technique with other preoperative localization techniques.

Erectile function status is highly associated with prostate-specific antigen bounce in localized prostate cancer patients treated with permanent prostate brachytherapy

OBJECTIVES

To examine the relationship between erectile function status and prostate-specific antigen bounce after prostate brachytherapy for localized prostate cancer.

METHODS

We identified 154 patients who were followed up for at least 24 months after brachytherapy. Erectile function status was assessed prospectively before brachytherapy (baseline), and 3, 6, 12, 18, 24 and 36 months postoperatively using the International Index of Erectile Function-15 questionnaire. Prostate-specific antigen bounce was defined as an increase of at least 0.4 ng/mL from a previous prostate-specific antigen level with a subsequent decline equal to, or less than, the initial nadir without treatment. A logistic regression analysis was used to identify a significant set of independent predictors of prostate-specific antigen bounce after brachytherapy.

RESULTS

Prostate-specific antigen bounce was observed in 38 (24.7%) men. The prostate-specific antigen bounce group had a higher erectile function domain score, higher orgasmic function domain score, and higher total International Index of Erectile Function-15 score before (at baseline) and after brachytherapy (3, 6, 12, 18, 24 and 36 months after brachytherapy) than their counterparts (P < 0.05). Of the 77 patients who completed the International Index of Erectile Function-15 questionnaire 18 months after brachytherapy (the median time of prostate-specific antigen bounce), sexual desire and intercourse satisfaction domain scores, and total International Index of Erectile Function scores 18 months after brachytherapy correlated with the occurrence of prostate-specific antigen bounce. A multivariate analysis identified the intercourse satisfaction domain score 18 months after brachytherapy as an independent indicator for the occurrence of prostate-specific antigen bounce (P = 0.008).

CONCLUSIONS

International Index of Erectile Function-15 score seems to be correlated with the prostate-specific antigen bounce in prostate cancer patients undergoing brachytherapy, and an occurrence of prostate-specific antigen bounce seems to be more likely in those who are more sexually active.

Relationship between sexual function and prostate-specific antigen bounce after iodine-125 permanent implant brachytherapy for localized prostate cancer

OBJECTIVE

To analyze clinical and dosimetric factors involved in prostate-specific antigen bounce in patients who underwent permanent implant brachytherapy for localized prostate cancer, and to study the relationships among prostate-specific antigen bounce, age and sexual function.

METHODS

Between March 2007 and April 2012, 116 patients with localized prostate cancer underwent permanent implant, iodine-125 brachytherapy. Patients receiving external-beam radiotherapy or who used phosphodiesterase-5 inhibitor pre- or post-treatment were excluded. Prostate-specific antigen bounce was defined as an increase of ≥0.2 ng/mL and ≥0.4 ng/mL above an initial prostate-specific antigen nadir followed by a subsequent decline to or below the initial nadir without treatment. Clinical and dosimetric factors involved in prostate-specific antigen bounce were analyzed using multivariate logistic regression analysis with the forced entry method.

RESULTS

The median age was 66 years (range 51-80 years), and prostate-specific antigen bounce on a prostate-specific antigen rise of ≥0.2 ng/mL occurred in 47 of the 116 participants (40.5%). The median period before the prostate-specific antigen bounce was 17.5 months (range 8-36 months). Patients with prostate-specific antigen bounce were younger and had higher sexual function before treatment (P = 0.003) than those who not show prostate-specific antigen bounce. Regression analysis results showed that young age and a high level of pretreatment sexual function were significant predictive factors for prostate-specific antigen bounce (P = 0.028 and P = 0.048).

CONCLUSION

Sexual function seems to be associated with a prostate-specific antigen bounce in patients undergoing permanent implant brachytherapy for localized prostate cancer, and it can be preserved after treatment if it is well present before treatment. Highly maintained sexual function after treatment might influence prostate-specific antigen bounce.

Microfocus X-ray imaging of the internal geometry of brachytherapy seeds

Precise and reliable geometrical data on the internal structure of seeds are indispensable for dosimetric calculation in brachytherapy. We used a novel microfocus X-ray imaging technique for observing the internal structure of brachytherapy seeds. Two popular (125)I seed models were evaluated. Obtained high precision images enabled us to observe the internal structure of seeds qualitatively. Geometrical size parameters were evaluated quantitatively with uncertainty of 0.01-0.04 mm (k=2).

Radioactive seed implantation combined with prosthesis denture in treatment of oral and maxillofacial malignancy

We sought to evaluate the effect of (125)I radioactive seed implantation combined with prosthesis denture on the treatment of oral and maxillofacial malignancy. For this purpose, 10 patients with glandule palatine malignancy were selected and subjected to the treatment plan of radioactive seed implantation during CT examination. All patients were treated as follow. The tumor tissues were extracted first. After 2 weeks, radioactive seeds were implanted in the palatine tissue and the prosthesis denture was made and worn for the tissue defect. Several radioactive seeds were still embedded in the tissue surface of the prosthesis at the same time; 24-36 seeds (average: 28) were used for each patient. All patients were followed up for 3-16 months and the results were evaluated. We found no tumor recurrence or metastasis around the target area in all patients. Significant improvement was shown in terms of speech, mastication, and facial appearance in all cases. Therefore, we concluded that in patients with glandule palatine malignancy, tumorectomy followed by radioactive seed implantation and prosthesis denture are effective for preventing the recurrence and metastasis of malignancy and improving the quality of life.

Diffusion pattern of low dose rate brachytherapy for prostate cancer in Japan

Permanent implant brachytherapy for prostate cancer using iodine-125 seeds was adopted in Japan in 2003. Here, we report on the diffusion pattern of this treatment in Japan since 2003. We examined the annual numbers of prostate cancer patients per hospital in Japan, who were treated with iodine-125 seed implant brachytherapy with or without external beam radiation therapy between 2003 and 2011. The hospitals were excluded from the count if brachytherapy was begun in a hospital within the given year, and thus was only available for part of the year. In 2004, 269 patients were treated by brachytherapy at only two hospitals. However, the numbers increased rapidly. A total of 1412 patients were treated at 23 hospitals in 2005, 2783 patients were treated at 83 hospitals in 2008, and 3793 patients were treated at 109 hospitals in 2011. The mean/median numbers of patients treated per hospital were 61.4/42 in 2005, 33.5/25 in 2008, and 35.0/24 in 2011. The number of hospitals where 24 or fewer patients were treated in a year increased. On the other hand, the number of hospitals with a volume of >48 patients per year was stable. Because a relationship between provider volume and outcomes following oncological procedures was shown, a careful evaluation of the effectiveness of permanent implant brachytherapy for prostate cancer is needed.

Iodine-125 seeds strand for treatment of tumor thrombus in inferior vena cava: an experimental study in a rabbit model

OBJECTIVE

The purpose of this study was to establish an animal model of implanted inferior vena cava tumor thrombus (IVCTT) and to evaluate the effect of linear iodine-125 seeds strand in treating implanted IVCTT.

METHODS

Tumor cell line VX2 was inoculated subcutaneously into New Zealand rabbit to develop the parent tumor. The tumor strip was inoculated into inferior vena cava (IVC) to establish the IVCTT model. The IVCTT was confirmed by multidetector computed tomography (MDCT) after 2 weeks. Twelve rabbits with IVCTT were randomly divided into two groups. Treatment group (group T; n = 6) underwent Iodine-125 seeds brachytherapy, and the control group (group C; n = 6) underwent blank seeds strand. The blood laboratory examination (including blood routine examination, hepatic and renal function), body weight, survival time, and IVCTT volume by MDCT were monitored. All rabbits were dissected postmortem, and the therapeutic effects were evaluated on the basis of histopathology. The proliferating cell nuclear antigen index (PI) and apoptosis index (AI) of IVCTT were compared between two groups. T test, Wilcoxon rank test, and Kaplan-Meier survival curve analysis were used.

RESULTS

The success rate of establishing IVCTT was 100 %. The body weight loss and cachexia of rabbits in group C appeared earlier than in group T. Body weight in the third week, the mean survival time, PI, AI in groups T and C were 2.23 ± 0.12 kg, 57.83 ± 8.68 days, (16.73 ± 5.18 %), (29.47 ± 7.18 %), and 2.03 ± 0.13 kg, 43.67 ± 5.28 days, (63.01 ± 2.01 %), (6.02 ± 2.93 %), respectively. There were statistically significant differences between group T and group C (P < 0.05). The IVCTT volume of group T was remarkably smaller than that of group C.

CONCLUSIONS

Injecting and suspensory fixing VX2 tumor strip into IVC is a reliable method to establish IVCTT animal model. The linear Iodine-125 seeds strand brachytherapy was a safe and effective method for treating IVCTT in rabbit model.

Cryosurgery in combination with brachytherapy of iodine-125 seeds for pancreatic cancer

A major limit of cryoablation is incomplete destruction of cells in the border zone of the cryogenic lesion in which the tissue temperature is warmer than (-)20 °C. The use of iodine-125 seed implantation is likely to be complementary to cryosurgery for treatment of pancreatic cancer. The procedure of cryosurgery and iodine-125 seed implantation is performed with percutaneous approaches under guidance of ultrasound and/or CT. The number of iodine-125 seeds implanted for every patient was 34 in median. Forty-nine patients with locally advanced pancreatic cancer received cryosurgery with combination of iodine-125 seed implantation. During a median follow-up of 18 months, the median of over all survival was 16.2 months. The 6-, 12-, 24- and 36-month overall survival rates were 94.9%, 63.1%, 22.8% and 9.5%, respectively. Compared with patients with cryosurgery alone, combination treatment shows higher the 6- and 12-month survival rates and longer the median survival.

Damage to pig bile duct caused by intraluminal brachytherapy using a (125)I ribbon

BACKGROUND

Stent occlusion by tumor ingrowth or overgrowth is the main cause of jaundice recurrence after metal stent insertion in patients with malignant obstructive jaundice (MOJ). The application of intraluminal brachytherapy (ILBT) in patients with MOJ results in local control of malignant tumors, which prolong stent patency.

PURPOSE

To evaluate the safety of ILBT in pig bile ducts using ribbons of iodine-125 ((125)I) seeds.

MATERIAL AND METHODS

Sixteen healthy pigs were randomly assigned to four groups of four pigs each. A (125)I seed ribbon was implanted into the common bile duct of each animal through an incision in the duct wall, and was fixed by suturing. The four groups of animals were sacrificed at 15, 30, 60, and 120 days after ribbon implantation, respectively. Serum bilirubin concentrations, alanine aminotransferase concentrations, and white blood cell counts before and after implantation were compared within each group. Pathological changes to the bile duct wall were observed using a light microscope. Morphological changes in biliary epithelial cells and organelles were observed with electron microscopy.

RESULTS

(125)I ribbons were successfully implanted in all animals without surgery-related death. We found no significant difference in pre- and post-implant serum bilirubin, alanine aminotransferase, or white blood cell counts. Light and electron microscopy showed that the most severe bile duct damage occurred in the 15-day group, which exhibited necrosis and detachment of numerous epithelial cells, and infiltration of inflammatory cells. Repair and proliferation of the bile duct epithelium began 30 days after implantation and was nearly complete at 60 days.

CONCLUSION

This study demonstrated the safety of ILBT using a (125)I ribbon in the pig bile duct. (125)I seed ribbons may be used in the treatment of MOJ in humans.

Source strength assay of iodine-125 seeds sealed within sterile packaging

Early‐stage prostate cancer is widely treated by iodine‐125 (I‐125) seed implantation. While quality assurance methods are in place to assure consistency in I‐125 seed source strength, current methods involve the breaking of the sterilization package, raising issues concerning sterility and time limitations. The purpose of this study was to develop a method of characterizing the total source strength of I‐125 seeds within a cartridge that has been sealed within a sterilization package and to evaluate the probability of detecting an out‐of‐calibration seed (aberrant seed). We defined a protocol to determine the ability of a well‐type ionization chamber to detect aberrant I‐125 seeds within a cartridge sealed in the sterilization package. A novel jig for a well‐type ionization chamber was designed to accommodate the sterilization package. One seed was chosen randomly from two cartridges containing five or 15 seeds (0.544 U source strength) and was exchanged with aberrant seeds of six different source strengths. The source strength was measured at each position within the cartridge. The results indicated that the response of the well chamber was sensitive to changes in the aberrant seed position within the cartridge and the source strength of the aberrant seed. The correlation coefficient between single seed and batch assay results was high (0.998). A novel jig and a measurement method using a well ionization chamber were developed, which allowed for a batch assay characterization of the total source strength of I‐125 seeds within a cartridge sealed within sterilization package. This method is simple, time‐saving, and offers greater practical application.

PACS number: D6.20.Dk

Tri-Modality therapy with I-125 brachytherapy, external beam radiation therapy, and short- or long-term hormone therapy for high-risk localized prostate cancer (TRIP): study protocol for a phase III, multicenter, randomized, controlled trial

Background

Patients with high Gleason score, elevated prostate specific antigen (PSA) level, and advanced clinical stage are at increased risk for both local and systemic relapse. Recent data suggests higher radiation doses decrease local recurrence and may ultimately benefit biochemical, metastasis-free and disease-specific survival. No randomized data is available on the benefits of long-term hormonal therapy (HT) in these patients. A prospective study on the efficacy and safety of trimodality treatment consisting of HT, external beam radiation therapy (EBRT), and brachytherapy (BT) for high-risk prostate cancer (PCa) is strongly required.

Methods/Design

This is a phase III, multicenter, randomized controlled trial (RCT) of trimodality with BT, EBRT, and HT for high-risk PCa (TRIP) that will investigate the impact of adjuvant HT following BT using iodine-125 (¹²⁵I-BT) and supplemental EBRT with neoadjuvant and concurrent HT. Prior to the end of September 2012, a total of 340 patients with high-risk PCa will be enrolled and randomized to one of two treatment arms. These patients will be recruited from more than 41 institutions, all of which have broad experience with ¹²⁵I-BT. Pathological slides will be centrally reviewed to confirm patient eligibility. The patients will commonly undergo 6-month HT with combined androgen blockade (CAB) before and during ¹²⁵I-BT and supplemental EBRT. Those randomly assigned to the long-term HT group will subsequently undergo 2 years of adjuvant HT with luteinizing hormone-releasing hormone agonist. All participants will be assessed at baseline and every 3 months for the first 30 months, then every 6 months until 84 months from the beginning of CAB.

The primary endpoint is biochemical progression-free survival. Secondary endpoints are overall survival, clinical progression-free survival, disease-specific survival, salvage therapy non-adaptive interval, and adverse events.

Discussion

To our knowledge, there have been no prospective studies documenting the efficacy and safety of trimodality therapy for high-risk PCa. The present RCT is expected to provide additional insight regarding the potency and limitations of the addition of 2 years of adjuvant HT to this trimodality approach, and to establish an appropriate treatment strategy for high-risk PCa.

Trial registration

UMIN000003992

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

Background

The aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose ¹²⁵I seeds.

Methods

We reviewed the records of 267 patients who underwent prostate brachytherapy with loose ¹²⁵I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration.

Results

A total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration.

Conclusion

We showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90.

Internal radiotherapy techniques using radiolanthanide praseodymium-142: a review of production routes, brachytherapy, unsealed source therapy

Radionuclides of rare earth elements are gaining importance as emerging therapeutic agents in nuclear medicine. β(-)-particle emitter 142Pr [T (1/2) = 19.12 h, E(-)β = 2.162 MeV (96.3%), Eγ = 1575 keV (3.7%)] is one of the praseodymium-141 (100% abundant) radioisotopes. Production routes and therapy aspects of 142Pr will be reviewed in this paper. However, 142Pr produces via 141Pr(n, γ) 142Pr reaction by irradiation in a low-fluence reactor; 142Pr cyclotron produced, could be achievable. 142Pr due to its high β(-)-emission and low specific gamma γ-emission could not only be a therapeutic radionuclide, but also a suitable radionuclide in order for biodistribution studies. Internal radiotherapy using 142Pr can be classified into two sub-categories: (1) unsealed source therapy (UST), (2) brachytherapy. UST via 142Pr-HA and 142Pr-DTPA in order for radiosynovectomy have been proposed. In addition, 142Pr Glass seeds and 142Pr microspheres have been utilized for interstitial brachytherapy of prostate cancer and intraarterial brachytherapy of arteriovenous malformation, respectively.

Dose to fingertips of staff preparing stranded iodine-125 seeds for permanent prostate implants

The aim of this study is to measure radiation dose to the fingertips of occupationally exposed workers handling stranded iodine-125 seeds during prostate implants. The doses were measured by thermoluminescence dosimetry at the nail of the index finger of both hands in three hospitals in the Netherlands. In all hospitals, measurements were carried out during the preparation of stranded IBt seeds, type Intersource(®) 1251L. The fingertip doses per procedure (mean ± SD) to the fingertip for workers from the three hospitals were estimated to be 0.29 ± 0.15 mSv (n = 6), <0.03 ± <0.02 mSv (n = 8) and 0.31 ± 0.16 mSv (n=16), respectively. The lower doses found for the hospital 2 workers are presumably related to the heavier shielding and longer utensils used in that hospital. Even in the case of hundreds of implant procedures per year, dose to the fingertips for occupationally exposed workers preparing stranded seeds is expected to be well below the annual limit for extremities of 500 mSv.

Endoscope-assisted brachytherapy for pancreatic cancer: From tumor killing to pain relief and drainage

Locally advanced or metastatic pancreatic cancer has been a long-term challenge to clinicians, due to the poor overall survival rate compared with that of other gastrointestinal malignancies. Recently, with the emerging applications of therapeutic endoscopic ultrasonography (EUS), EUS- guided fine needle injection with antitumor agents is considered a promising modality. In this review, we summarize recently published data on the efficacy of endoscope guided interventional procedures with radioactive seeds. Firstly, EUS-guided iodine-125 seed implantation was reported to have a short-term efficacy on pancreatic cancer, with a three-month partial remission rate of 13.6% to 27%. Thereafter, feasibility of celiac ganglion radiation was tested in animal models to achieve pain relief. Recently, a seed-based stent has been introduced in the endoscopic retrograde cholangio-pancreatography (ERCP) drainage of biliary obstruction caused by pancreatic cancer, with a response rate of 72.7%. In addition, we discuss the potential of radioactive seed-based, endoscope-assisted interventional treatment of patients with locally advanced pancreatic cancer. Further studies should focus on the precise amount and distribution of seeds with the aim to improve the survival rate as well as the quality of life.

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

Background

The aim was to identify preimplant factors affecting postimplant prostate volume and the increase in prostate volume after transperineal interstitial prostate brachytherapy with ¹²⁵I free seeds.

Methods

We reviewed the records of 180 patients who underwent prostate brachytherapy with ¹²⁵I free seeds for clinical T1/T2 prostate cancer. Eighty-one (45%) of the 180 patients underwent neoadjuvant hormonal therapy. No patient received supplemental external beam radiotherapy. Postimplant computed tomography was undertaken, and postimplant dosimetric analysis was performed. Univariate and multivariate analyses were performed to identify preimplant factors affecting postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

Results

Preimplant prostate volume by transrectal ultrasound, serum prostate-specific antigen, number of needles, and number of seeds implanted were significantly correlated with postimplant prostate volume by computed tomography. The increase in prostate volume after implantation was significantly higher in patients with neoadjuvant hormonal therapy than in those without. Preimplant prostate volume by transrectal ultrasound, number of needles, and number of seeds implanted were significantly correlated with the increase in prostate volume after implantation. Stepwise multiple linear regression analysis showed that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy were significant independent factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

Conclusions

The results of the present study show that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy are significant preimplant factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

Biochemical and biological characterization of a new oxidized avidin with enhanced tissue binding properties

Chicken avidin and bacterial streptavidin are widely employed in vitro for their capacity to bind biotin, but their pharmacokinetics and immunological properties are not always optimal, thereby limiting their use in medical treatments. Here we investigate the biochemical and biological properties of a new modified avidin, obtained by ligand-assisted sodium periodate oxidation of avidin. This method allows protection of biotin-binding sites of avidin from inactivation caused by the oxidation step and delay of avidin clearance from injected tissue by generation of aldehyde groups from avidin carbohydrate moieties. Oxidized avidin shows spectroscopic properties similar to that of native avidin, indicating that tryptophan residues are spared from oxidation damage. In strict agreement with these results, circular dichroism and isothermal titration calorimetry analyses confirm that the ligand-assisted oxidation preserves the avidin protein structure and its biotin binding capacity. In vitro cell binding and in vivo tissue residence experiments demonstrate that aldehyde groups provide oxidized avidin the property to bind cellular and interstitial protein amino groups through Schiff's base formation, resulting in a tissue half-life of 2 weeks, compared with 2 h of native avidin. In addition, the efficient uptake of the intravenously injected (111)In-BiotinDOTA (ST2210) in the site previously treated with modified avidin underlines that tissue-bound oxidized avidin retains its biotin binding capacity in vivo. The results presented here indicate that oxidized avidin could be employed to create a stable artificial receptor in diseased tissues for the targeting of biotinylated therapeutics.

OXavidin for tissue targeting biotinylated therapeutics

Avidin is a glycoprotein from hen egg white that binds biotin with very high affinity. Here we describe OXavidin, a product containing aldehyde groups, obtained by ligand-assisted sugar oxidation of avidin by sodium periodate. OXavidin chemically reacts with cellular and tissue proteins through Schiff's base formation thus residing in tissues for weeks while preserving the biotin binding capacity. The long tissue residence of OXavidin as well as that of OXavidin/biotinylated agent complex occurs in normal and neoplastic tissues and immunohistochemistry shows a strong and homogenous stromal localization. Once localized in tissue/tumor, OXavidin becomes an “artificial receptor” for intravenous injected biotin allowing tumor targeting with biotinylated therapeutics like radioisotopes or toxins. Moreover, present data also suggest that OXavidin might be useful for the homing of biotinylated cells. Overall, OXavidin exhibits a remarkable potential for many different therapeutic applications.

Health-related quality of life using SF-8 and EPIC questionnaires after treatment with radical retropubic prostatectomy and permanent prostate brachytherapy

OBJECTIVE

The health-related quality of life (HRQOL) after treatment of prostate cancer is examined using a new HRQOL tool. HRQOL, based on the expanded prostate cancer index composite (EPIC) and SF-8 questionnaires, was prospectively compared after either a radical retropubic prostatectomy (RRP) or a permanent prostate brachytherapy (PPB) at a single institute.

METHODS

Between October 2005 and June 2007, 96 patients were treated by an RRP and 88 patients were treated by a PPB. A HRQOL survey was completed at baseline, and at 1, 3, 6 and 12 months after treatment, prospectively.

RESULTS

The general HRQOL in the RRP and PPB groups was not different after 3 months. However, at baseline and 1 month after treatment, the mental component summary was significantly better in the PPB group than in the RRP group. Moreover, the disease-specific HRQOL was worse regarding urinary and sexual functions in the RRP group. Urinary irritative/obstructive was worse in the PPB group, but urinary incontinence was worse in the RRP group and had not recovered to baseline after 12 months. The bowel function and bother were worse in the PPB group than in the RRP group after 3 months. In the RRP group, the patients with nerve sparing demonstrated the same scores in sexual function as the PPB group.

CONCLUSIONS

This prospective study revealed the differences in the HRQOL after an RRP and PPB. Disease-specific HRQOL is clarified by using EPIC survey. These results will be helpful for making treatment decisions.

Prostate-specific antigen bounce after prostate brachytherapy: review of a confusing phenomenon

Prostate brachytherapy is a commonly used modality for the treatment of prostate cancer. After prostate brachytherapy, the prostate-specific antigen (PSA) level may fluctuate and increase temporarily without a clear reason in 30-40% of successfully treated men. This phenomenon is called "PSA bounce" and engenders anxiety on the part of the patient and physician. Having reviewed the literature we found 19 articles and summarized in the current review to delineate the facts of this relatively common and ambiguous phenomenon. Although several patient and treatment related factors were assessed by studies, only age remained as the most consistent predictor.