125I Seeds Research Articles

Radioactive 125I Seed Inhibits Cell Migration and Invasion and Promotes Apoptosis by Inactivating the VEGFR2 Signaling Pathway in Cholangiocarcinoma.

To investigate the potential mechanisms of 125I seed implantation therapeutic treatment on inactivating the VEGFR2/PI3K/AKT pathway in cholangiocarcinoma. The human cholangiocarcinoma cell lines HCCC-9810 and HuCCT1 were purchased for in vitro studies. The BALB/c nude mice were obtained for in vivo studies. The proliferation of cells was detected by CCK-8, colony formation, and BrdU staining. The migration and invasion of cells were determined by wound healing assay and Transwell assay, respectively. Hematoxylin and eosin staining was utilized for histological evaluation. Protein expression was determined by western blotting and immunohistochemistry. Compared with the control group, .6mCi group and .8mCi group inhibited cholangiocarcinoma cells proliferation, invasion, migration, and promoted apoptosis, the protein expression of p-VEGFR2, VEGFR2, PI3K, p-AKT/AKT, cyclin B1, cyclin A, CDK1, and Bcl-2 was decreased. Similar results were obtained from in vitro experiments. However, when VEGF is overexpressed, the inhibitory effect of .8mCi was partially significantly reversed on cholangiocarcinoma cells. The in vivo studies further confirmed the inhibitory effects of .6mCi group and .8mCi group on cholangiocarcinoma. 125I seed irradiation could inhibit cholangiocarcinoma cells proliferation, migration, and invasion and promote apoptosis through inactivation of the VEGFR2/PI3K/AKT signaling pathway.

The efficacy and safety of 125I seeds combined with biliary stent placement versus stent placement alone for malignant biliary obstruction: a systematic review and meta-analysis.

Currently, it is unknown whether iodine-125 (125I) stent implantation has the same therapeutic effect on patients with malignant biliary obstruction (MBO) caused by different cancers. This meta-analysis aimed to investigate whether 125I implantation in patients with MBO is superior to biliary stent placement in efficacy and safety, and to further explore the difference in efficacy and safety of seed implantation in different patients through subgroup analysis. A systematic search of the PubMed, Wiley Online Library, Cochrane library, Google Scholar, the Web of Science, China National Knowledge Infrastructure (CNKI), VIP, and Wanfang databases was conducted to screen all relevant studies up to October 30, 2022. Articles were not subjected to language or geographical limitations, but were required to meet the inclusion and exclusion criteria for this study. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of articles. The primary endpoint was survival, which was defined as the interval between initial treatment and death or the end of study. Meta analysis was performed using Stata/SE15.0. A total of 12 eligible studies were enrolled including 679 patients. All the included studies were single-center studies carried out in China. The results showed that the death risk and stent occlusion risk in the 125I group was 0.441 times [95% confidence interval (CI): 0.315 to 0.619, P<0.001; I2=0%, fixed, IV] and 0.534 times (95% CI: 0.433to0.658, P=0.003; I2=45.4%, fixed, IV) lower than the control group, respectively. There was no significant statistical difference in the risk of complications between the 2 groups [risk ratio (RR) =1.024, 95% CI: 0.963to1.090, P=0.450; PQ=0.640; I2=0%]. The reduction level of total bilirubin [TBIL; weighted mean differences (WMDs) =-14.969, 95% CI: -28.670 to -1.267, P=0.032; PQ=0.409, I2=2.1%) and aspartate transaminase (AST; WMD =-14.653, 95% CI: -23.246 to -6.060, P=0.001; PQ=0.900, I2=0%) in the 125I group was higher than that in the control group 1 week after surgery. The efficacy and safety of 125I for MBO patients were found to be independent of the type of tumor causing MBO (P for meta regression >0.05). For patients with MBO caused by hilar tumor or other tumors, 125I seed implantation can reduce the death risk and stent occlusion risk, prolong the time of survival and stent patency, and does not increase the complication risk. Due to the limitations of the study population, these findings should be further validated in other populations and regions.

Effect of I-125 Seed Implantation on Lung Cancer and Its Environmental Impact.

This paper compares the efficacy and adverse effects of iodine-125 ( 125 I) seed implantation and external beam radiotherapy (EBRT) in the treatment of lung cancer as well as impact of the 125 I radiation on the environment around the patients. A total of 40 patients who were admitted with lung cancer to our hospital from October 2017 to October 2018 were enrolled into this study. The patients were randomly assigned into study groups treated with 125 I seed implantation (20 patients) and a control group treated with EBRT (20 patients). The patients were followed up for 6 mo by CT scanning of the tumor size as well as measuring serum carcinoembryonic antigen (CEA), cytokeratin fragment (CYRA21-1), and neurospecific enolase (NSE) levels. The dose rate of 125 I at various distances and times after implantation was also measured. The local tumor control rate was higher in the study group than in the control group. CEA, NSE and CYFRA21-1 significantly decreased from the pre-treatment baseline in both groups (p < 0.05). Side effects of pneumothorax, hemoptysis, chest pain, and leukopenia occurred in the patients treated with 125 I seed implantation. Radiation of the 125 I isotope, which was correlated with the number of implanted 125 I seeds, decreased rapidly in a time- and distance-dependent manner. A lead apron could significantly block radiation of 125 I. Compared to EBRT, brachytherapy with 125 I seed implantation in the lung cancer had a better therapeutic outcome with fewer complications. A lead apron could protect members of patient's family as well as public from 125 I radiation.

I-125 seeds brachytherapy combined with immunotherapy for MET amplification in non-small cell lung cancer from clinical application to related lncRNA mechanism explore: a case report.

Advanced non-small cell lung cancer (NSCLC) with MET amplification primarily relies on MET inhibitors for treatment, but once resistance occurs, the available treatment options are limited and the prognosis is typically poor. A 57-year-old man with advanced NSCLC and C-MET amplification was initially treated with crizotinib but developed progressive disease. After the antirotinib treatment, he achieved a partial response for a year. Genetic testing showed high PD-L1 expression, and he was treated with pembrolizumab and chemotherapy for 3months, with partial response. Maintenance therapy with pembrolizumab and local I-125 seeds brachytherapy (ISB) was given after the lung lesion progressed but other lesions remained stable. The therapy resulted in significant resolution of the right upper lung lesion. It demonstrates the effectiveness of ISB-ICI combination in treating MET amplification advanced NSCLC. Ongoing research and treatment innovation are important in managing advanced NSCLC with complex genetic aberrations. To explore the candidate mechanism of ISB therapy response, we download public genetic data and conduct different expression Lncrnas analysis and pathway analysis to discover radiotherapy related sensitive or resistance lncRNAs and pathways, we found that AL654754.1 is a key lncRNA with radiotherapy response, and it also include in classical p53 and Wnt signaling pathway. Overall, the clinical case reports, combined with the exploration of underlying mechanisms, provide positive guidance for the precise treatment of lung cancer.

Biliary intervention combined with lenvatinib+ PD-1 inhibitor of Klatskin tumor complicated with malignant obstructive jaundice.

e14620 Background: Hilar Cholangiocarcinoma (Klatskin tumor) is a rare and highly aggressive cancer that occurs at or near the junction of the right and left hepatic ducts. Gemcitabine + cisplatin has been established as an effective first-line treatment. However, this malignancy is commonly complicated by malignant biliary obstruction which may gradually damage patients’ liver function and may limit the chemotherapy. In addition, Cumulative clinical evidence showed that tyrosine kinase inhibitor (TKI) combined with immunotherapy is represented as a promising alternative. This study aimed to evaluate the clinical value of biliary intervention combined with the Lenvatinib+PD-1 inhibitor (Tislelizumab/Sintilimab) for the Klatskin tumor. Methods: From January 2020 to December 2022, 21 Klatskin tumor patients with malignant hilar biliary obstruction (MHBO) were included. All included patients received biliary decompression by metal stent + Iodine-125 seed strand (ISS) implantation. The number of 125I seeds to be implanted was determined according to the plan of the preoperative computerized treatment planning system (TPS). The procedure-related outcomes were evaluated regarding successful drainage and complications. In addition, the survival of patients who received successful biliary drainage and patients who received sequential systemic anticancer treatment were analyzed. Successful biliary drainage was defined as the serum total bilirubin level dropped by 75% of the preoperative value within 4 weeks. Major complications referred to those that result in death or serious adverse effects including sepsis, uncontrollable biliary or intestinal bleeding, and acute renal failure. The time between stent insertion and death was defined as patient survival. Results: 71.4% achieved successful drainage, significant improvements were observed from before to one month after the procedure in liver function values, including total bilirubin (TBIL), and direct bilirubin (DBIL) (all P&lt;0.001). Minor complications occurred in 5 patients (23.8%) in all patients, including 1 patient (4.8%) who experienced cholangitis, and 4 patients (19%) who suffered abdominal pain. No major procedure-related complication was observed. The median overall survival(mOS) of 21 patients was 6.1 months. Patients who received successful biliary drainage (n=15) had longer mOS than those who received unsuccessful biliary drainage(n=6) [7.4 months vs. 3.5 months, respectively, P&lt;0.001]. Patients who received sequential Lenvatinib+ Pembrolizumab after effective drainage(n=9) had longer mOS than those who only received palliative therapy(n=6) [7.4 months vs. 5.2 months, respectively, P=0.028]. Conclusions: Biliary intervention + ISS combined with the following Lenvatinib+ PD-1 inhibitor is safe and feasible for cholangiocarcinoma patients complicated with obstructive jaundice.

Efficacy and Safety of I125 Seed Implantation Combined with Surgery on Glioma: A Meta-analysis

Efficacy and Safety of I125 Seed Implantation Combined with Surgery on Glioma: A Meta-analysis

Computed tomography-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by non-small cell lung cancer.

Airway stenosis secondary to non-small cell lung cancer (NSCLC) is one of the severe complications that can lead to life-threatening outcomes. To investigate the clinical utility of computed tomography (CT)-guided interstitial implantation of radioactive I-125 seeds in the treatment of hilar airway stenosis caused by NSCLC. The cases of hilar airway stenosis caused by NSCLC in our hospital from 2017 to 2022 were collected and divided into observation and control groups. Both groups underwent conventional lung cancer treatment, and the observation group was treated with CT-guided interstitial implantation of radioactive I-125 seeds. The mean tumor diameter, hilar airway stenosis, and obstructive pneumonia scores at 3 months after treatment were compared between the two groups. After 3 months of treatment, the mean tumor diameter (28.8 ± 9.3 mm vs 49.33 ± 16.75 mm, P < 0.001), hilar airway stenosis (20.55 ± 30.36% vs 84.85 ± 26.19%, P < 0.001), and obstructive pneumonia score (2.19 ± 1.41 vs 3.48 ± 1.12, P < 0.001) of the observation group were significantly lower than those of the control group. CT-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by NSCLC can effectively reduce the tumor volume, relieve airway stenosis, and alleviate the associated obstructive pneumonia and has a certain value of application in the clinic.

Evaluation of dose perturbations around iodine-125 seed sources in supplemental external beam prostate radiotherapy.

We investigated dose perturbations caused by 125I seeds in patients undergoing supplemental external beam radiotherapy (EBRT) for prostate cancer. We examined two types of nonradioactive seed models: model 6711 and model STM1251. All experiments were performed using a water-equivalent phantom. Radiochromic film was used to measure the dose distributions adjacent to the seeds upstream and downstream of the external beam source. Single and clusters of multiple seeds were placed in slots in a solid water (SW) slab to measure dose perturbations with separate versus dense seed placement at beam energies of 6 or 10 MV. Monte Carlo simulations (MCSs) were also performed to include the theoretical basis against film dosimetry. Distinct patterns of dose enhancement (buildup [BU]) were upstream, and dose reduction (builddown [BD]) were downstream of the radiation source. Model 6711 with lower photon beam energies produced larger dose perturbations of BU and BD than the model STM1251. The results showed the same tendency with different seed placements and beam energies. However, these differences were not observed in the rotational irradiation measurement, which replicated a clinical plan. Dose perturbations around seeds result in dose enhancement and dose reduction with varying impact depending on the photon beam energy and seed type. This has the potential to cancel out these perturbations using multiple beam direction fields.

Prognostic Value of Systemic Immune-Inflammation Index-Based Nomogram in Patients with Extrahepatic Cholangiocarcinoma Treated by Percutaneous Transhepatic Biliary Stenting Combined with 125I Seed Intracavitary Irradiation.

This study aimed to investigate the prognostic value of systemic immune-inflammation index (SII) in patients with extrahepatic cholangiocarcinoma (EHCC) treated by percutaneous transhepatic biliary stenting (PTBS) combined with 125I seed intracavitary irradiation and further develop a predictive model related to SII. A total of 145 patients with EHCC who received PTBS combined with 125I seed implantation were retrospectively analyzed. The optimal cut-off value of SII was identified by receiver operating characteristic (ROC) curve analysis. Kaplan-Meier curves and Cox regression were applied to estimate the prognostic value of SII and identify other significant factors of overall survival (OS). Additionally, a novel nomogram was constructed. The concordance index (C-index), calibration plots and decision curve analysis were used to evaluate the performance of the nomogram model. The optimal cut-off value for preoperative SII of 890.2 stratified the patients into High-SII (H-SII) and Low-SII (L-SII) groups. Univariate and multivariate analyses demonstrated that SII was an independent factor for OS. We also found that better therapeutic effect could be obtained with combined postoperative chemotherapy (P < 0.001). Moreover, we revealed that elevated preoperative CA19-9 (P = 0.038) and TBIL level (P = 0.024) were reason for poor prognosis of EHCC. A well-discriminated and calibrated nomogram was developed to predict the 1-year and 2-year OS of EHCC (C-index: 0.709). The SII may be a feasible and convenient prognosis predictor for EHCC. The comprehensive nomogram based on SII presented in this study is a promising model for predicting OS in EHCC patients after PTBS combined with 125I seed intracavitary irradiation.

Automatic numeration and localization of I-125 seeds in the post-implant prostate images based on CT and radiography image fusion

Automatic numeration and localization of I-125 seeds in the post-implant prostate images based on CT and radiography image fusion

Targeted Axillary Dissection with 125I Seed Placement Before Neoadjuvant Chemotherapy in a Danish Multicenter Cohort

BackgroundTargeted axillary dissection (TAD), with marking of the metastatic lymph node before neoadjuvant chemotherapy (NACT), is increasingly used for breast cancer axillary staging. In the case of axillary pathological complete response (ax-pCR), axillary lymph node clearance can be omitted. Several marking methods exist, most using re-marking before surgery. Feasibility, learning curve, and identification rate (IR) vary. Marking with 125I seed before NACT makes re-marking at surgery redundant, possibly increasing feasibility and IR. Here, TAD with 125I seed placed before NACT is evaluated in a Danish multicenter cohort.MethodsPatients staged with 125I TAD in Denmark between 1 January 2016 and 31 August 2021 were included. Patients were identified in radioactivity-emitting implant registries at the radiology departments and from the Danish Breast Cancer Group database. Data were extracted from patients’ medical records. Information on patient/tumor characteristics, 125I seed activity, marking period, TAD success, number of sentinel nodes (SNs), the histopathological status of excised nodes, and whether the marked lymph node (MLN) was an SN were registered.Results142 patients were included. The IR of the MLN was 99.3%, and the IR of the SLNB was 91.5%. TAD success was 91.5%. Minor challenges in marking or removal of the MLN were noted in three patients. In 72.3% of the patients, the MLN was a sentinel node. Overall, 40.8% had axillary pCR.ConclusionTAD with 125I seed marking before NACT is feasible without re-marking at surgery and with only minor surgical challenges. The IR is high. Staging with TAD spares 41% of breast cancer patients an axillary dissection.

Radioguided surgery of mesenchymal tumors with 125I seeds

IntroductionRadioguided surgery uses radioactive substances to identify and remove hard-to-locate lesions. Mesenchymal tumors constitute a heterogeneous group of neoplasms derived from the mesoderm, including benign lesions and malignant sarcomas. The aim of this study was to evaluate the ability of 125I radioactive seeds to guide intraoperative localization of mesenchymal tumors, analyzing the complication rates and evaluating the margins of the surgical specimens retrieved. MethodsRetrospective observational study of all consecutive patients undergoing radioguided surgery of a mesenchymal tumor with a 125I radioactive seed from January 2012 to January 2020 at a tertiary referral center in Spain. The seed was inserted percutaneously guided by ultrasound or computed tomography in an outpatient setting. ResultsFifteen lesions were resected in 11 interventions in 11 patients, recovering all lesions marked (100%) with a 125I seed. The lesions included areas of benign fibrosis (26.7%), cellular angiofibroma (6.7%), desmoid tumor (20%), solitary fibrous tumor (13.3%), chondrosarcoma (6.7%), and pleomorphic sarcoma (26.7%), with a high rate of recurrent tumors (60%). There was only one complication (6.7%) due to the seed falling within the surgical bed. According to the UICC classification of residual tumors, 80% of the lesions resulted in an R0 resection, 6.7% were R1 resections, and 13.3% were R2 resections. ConclusionRadioguided surgery is an accurate technique for the resection of hard-to-locate mesenchymal tumors.

Identification of a novel peptide targeting TIGIT to evaluate immunomodulation of 125I seed brachytherapy in HCC by near-infrared fluorescence.

Hepatocellular carcinoma (HCC) has very poor prognosis due to its immunosuppressive properties. An effective measure to regulate tumor immunity is brachytherapy, which uses 125I seeds planted into tumor. T cell immune receptors with immunoglobulin and ITIM domains (TIGIT) is highly expressed in HCC. The TIGIT-targeted probe is expected to be an effective tool for indicating immunomodulation of 125I seed brachytherapy in HCC. In this study, We constructed a novel peptide targeting TIGIT to evaluate the immune regulation of 125I seed brachytherapy for HCC by near-infrared fluorescence (NIRF). Expression of TIGIT by immunofluorescence (IF) and flow cytometry (FCM) in different part and different differentiated human liver cancer tissues was verified. An optical fluorescence probe (Po-12) containing a NIRF dye and TIGIT peptide was synthesized for evaluating the modulatory effect of 125I seed brachytherapy. Lymphocytes uptake by Po-12 were detected by FCM and confocal microscopy. The distribution and accumulation of Po-12 in vivo were explored by NIRF imaging in subcutaneous and orthotopic tumors. IHC and IF staining were used to verify the expression of TIGIT in the tumors. TIGIT was highly expressed in HCC and increased with tumor differentiation. The dye-labeled peptide (Po-12) retained a stable binding affinity for the TIGIT protein in vitro. Accumulation of fluorescence intensity (FI) increased with time extended in subcutaneous H22 tumors, and the optimal point is 1 h. TIGIT was highly expressed on lymphocytes infiltrated in tumors and could be suppressed by 125I seed brachytherapy. Accumulation of Po-12-Cy5 was increased in tumor-bearing groups while declined in 125I radiation group.

Celiac plexus block combined with 125I seeds for refractory epigastric pain from abdominal malignancies: a retrospective case-control study.

To evaluate the clinical efficacy of celiac plexus block (CPB) combined with 125I seeds implantation (ISI) for refractory epigastric pain from abdominal malignancies. The data of 81 patients with refractory epigastric pain [visual analog scale (VAS) score ≥ 4] from abdominal malignancies were collected in this retrospective case-control study. Group A (n = 40) was treated with CPB alone, while Group B (n = 41) underwent CPB combined with ISI. The primary study endpoints were the VAS score, quality of life (QoL), and local tumor control (LTC) rate. The secondary endpoints were complications, progression-free survival (PFS), and overall survival (OS). The VAS scores at week 2 (T2), week 4 (T4), week 8 (T8), and week 12 (T12) in both groups were significantly lower compared with the pretreatment values (all P < 0.01). VAS scores in Group B showed a sustained decrease, especially for "mild pain" and "moderate pain," while the VAS scores in Group A rebounded at T8 and T12 (both P < 0.01). The QoL in Group B improved significantly from T4 until T12, which better than that at T12 in Group A (all P < 0.01). The LTC rates at T8 were 35.0% and 92.7% in Groups A and B, respectively, with a significant difference (P < 0.01). Group B had a slightly lower complication rate and a slightly longer median PFS/OS than group A, but neither was statistically different (P = 0.09 and P = 0.99, respectively). CPB combined with ISI performs more sustained pain relief (up to 12weeks) compared to CPB alone, and ultimately improves the patients' QoL.

ASO Author Reflections: Feasibility of 125I Seed Targeted Axillary Dissection.

ASO Author Reflections: Feasibility of 125I Seed Targeted Axillary Dissection.

PD15-07 PROSTATE BRACHYTHERAPY CASE VOLUME IN THE COMMUNITY SETTING DOES NOT AFFECT ONCOLOGIC OUTCOMES

You have accessJournal of UrologyCME1 Apr 2023PD15-07 PROSTATE BRACHYTHERAPY CASE VOLUME IN THE COMMUNITY SETTING DOES NOT AFFECT ONCOLOGIC OUTCOMES Kevin Chang, Lufan Wang, Janet Cowan, Osama Mohamad, Peter Carroll, and Matthew Cooperberg Kevin ChangKevin Chang More articles by this author , Lufan WangLufan Wang More articles by this author , Janet CowanJanet Cowan More articles by this author , Osama MohamadOsama Mohamad More articles by this author , Peter CarrollPeter Carroll More articles by this author , and Matthew CooperbergMatthew Cooperberg More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003262.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Prostate cancer brachytherapy (BT) is a treatment modality that has been declining in usage. The goal of this study is to describe the relationship between facility BT case volume and cancer-specific outcomes in patients with localized prostate cancer (PCa). METHODS: We identified patients in CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) diagnosed with localized PCa between 1999-2007 and treated with BT. Only community sites had sufficient recorded cases for inclusion. BT case volume of each facility was based on its number of BT-treated PCa patients, with those above the 75th percentile categorized as high-volume. Our primary outcome is the effect of case volume on biochemical failure based on the Phoenix definition or receipt of salvage treatment after primary BT to account for a large proportion of missing PSA follow-up values in our cohort. Secondary outcomes included patient-reported UCLA Prostate Cancer Index scores for urinary, sexual, and bowel function and bother. RESULTS: We identified 1,282 BT-treated patients with localized PCa with median follow-up of 9 years (3.8 years based on last PSA) across 18 community sites with a median of 210 BT cases. Overall, 92% of patients were National Comprehensive Cancer Network low- or intermediate-risk and 98% received low dose rate BT. 722 patients (56.3%) received BT at high-volume (>210 cases) community facilities and 560 patients (43.7%) at low-volume (10-210 cases) facilities. High-volume facilities predominantly used Pd-103 seeds while low-volume facilities predominantly used I-125 seeds (p<0.01). A greater proportion of patients at low-volume facilities had pre-BT hormone therapy (p<0.01). High-volume facility status was not associated with improved rates of biochemical failure (10-year cumulative incidence 10.3% vs 12.5%, log-rank p=0.27, Figure 1A) or prostate cancer specific mortality (10-year cumulative incidence 4.0% vs 4.5%, log-rank p=0.62). Patient-reported scores of urinary, sexual, and bowel bother at 6 months following BT were comparable (Figure 1B). CONCLUSIONS: BT-treated patients with localized PCa at high-volume community facilities have similar rates of biochemical failure, prostate cancer specific mortality, and trends in quality of life outcomes compared to those treated at low-volume community facilities. Source of Funding: UCSF Goldberg-Benioff Program in Translational Cancer Biology © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e421 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kevin Chang More articles by this author Lufan Wang More articles by this author Janet Cowan More articles by this author Osama Mohamad More articles by this author Peter Carroll More articles by this author Matthew Cooperberg More articles by this author Expand All Advertisement PDF downloadLoading ...

Use of 125I seeds in the surgical management of a complex oncological case

Use of 125I seeds in the surgical management of a complex oncological case

Effect of prostate brachytherapy case volume in the community setting on oncologic outcomes.

339 Background: A volume-outcome relationship has not yet been comprehensively established for prostate cancer brachytherapy, a treatment modality that is declining in usage, with regard to cancer-specific outcomes. The goal of this study is to describe the relationship between facility brachytherapy case volume and cancer-specific outcomes in patients with localized prostate cancer. Methods: We identified patients in CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) diagnosed with localized prostate cancer between 1999-2007 and treated with brachytherapy. Only community hospital settings had sufficient documented cases for inclusion. The brachytherapy case volume of each facility was based on its total number of brachytherapy-treated prostate cancer patients with facilities above the 75th percentile categorized as high-volume facilities. The primary outcome was biochemical failure based on the Phoenix definition or receipt of salvage treatment after primary brachytherapy. We used logistic regression to compute a propensity score for on high vs low volume facility based on demographic, clinical, and treatment variables. Cumulative incidence of biochemical failure and prostate cancer specific mortality of patients were assessed with lifetable estimates, log-rank test, and Cox proportional hazards regression, adjusted for propensity score and case volume. Secondary outcomes included patient-reported UCLA Prostate Cancer scores for urinary, sexual, and bowel function and bother. Results: We identified 1,282 patients with localized prostate cancer treated with brachytherapy between 1999-2007 across 18 community facilities with median follow-up of 9 years. The median number of brachytherapy cases over the 8 study years was 210. 722 patients (56.3%) received brachytherapy at high-volume (&gt;210 cases) community facilities and 560 patients (43.7%) at low-volume (10-210 cases) facilities. High-volume facilities predominantly used Pd-103 seeds while low-volume facilities predominantly used I-125 seeds. A greater proportion of patients at low-volume facilities had pre-brachytherapy hormone therapy (47% vs 26%; p&lt;0.01). Cumulative incidence of biochemical failure at 10 years was 10.3% for high-volume facilities and 12.5% for low-volume facilities (p=0.27). Cumulative incidence of prostate cancer specific mortality at 10 years was 4.0% for high-volume facilities and 4.5% for low-volume facilities (p=0.62). Patient-reported scores of urinary, sexual, and bowel bother at 6 months following brachytherapy were comparable between the two groups. Conclusions: Patients with localized prostate cancer treated with brachytherapy at high-volume community facilities have similar rates of biochemical failure, prostate cancer specific mortality, and trends in quality of life outcomes compared to those treated at low-volume community facilities.

Monte Carlo Dosimetric Study of Percutaneous Vertebroplasty and Brachytherapy for the Treatment of Spinal Metastases.

Percutaneous vertebroplasty employs bone cement for injecting into the fractured vertebral body (VB) caused by spinal metastases. Radioactive bone cement and also brachytherapy seeds have been utilized to suppress the tumor growth in the VB. This study aims to investigate the dose distributions of low-energy brachytherapy seeds, and to compare them to those of radioactive bone cement, by Monte Carlo simulation. In this simulation study, nine CT scan images were imported in Geant4. For the simulation of brachytherapy, I-125, Cs-131, or Pd-103 seeds were positioned in the VB, and for the simulation of vertebroplasty, the VB was filled by a radioactive cement loaded by P-32, Ho-166, Y-90, or Sm-153 radioisotopes. The dose-volume histograms of the VB, and the spinal cord (SC) were obtained after segmentation, considering that the reference dose is the minimum dose covered 95% of the VB. The SC sparing was improved by using beta-emitting cement because of their steep gradient dose distribution. I-125 seeds and Y-90 radioisotope showed better VB coverage for brachytherapy and vertebroplasty techniques, respectively. Pd-103 seeds and P-32 radioisotope showed better SC sparing for brachytherapy and vertebroplasty, respectively. The minimum mean doses that covered 100% of the VB were 62.0%, 56.5%, and 45.0% for I-125, Cs-131, and Pd-103 seeds, and 28.3%, 28.6%, 32.9%, and 17.7%, for P-32, Ho-166, Y-90, and Sm-153 sources, respectively. I-125 and Cs-131 seeds may be useful for large tumors filling the entire VB, and also for the extended tumors invading multiple vertebrae. Beta-emitting bone cement is recommended for tumors located near the SC.

Technical Report: Quality Assurance for 125I Seed Sources in Permanent Prostate Brachytherapy

This technical report provides useful information on the current status and issues of quality control in 125I seed source strength measurement for Permanent Prostate Brachytherapy in Japan.With the spread of 125I seed brachytherapy, the traceability of source strength measurements with the single-seed assay was established in Japan. This allows medical facilities to measure reference air kerma rate of 125I seeds with their own well-type of ionization chamber. However, it is difficult to maintain the traceability chain because the 125I reference air kerma rate standards have been hardly utilized by medical facilities so far. Meanwhile, some serious incidents of contamination of the different source strengths and dead seeds were reported in Japan.To address the specific issues in Japan, JASTRO Brachytherapy Subcommittee established a working group (WG) in 2021. The goal of this WG is to investigate the management methods of source strength measurement used in medical facilities, and to discuss the ideal and practicable methods of source management such as verifying the number of seeds and source strength. Initially, a questionnaire survey was conducted to facilities offering 125I seed brachytherapy in Japan. Sixty-seven out of 95 facilities responded (response rate 70.5%). This survey revealed that 41% of facilities did not perform either confirmation of the number of seeds or measurement of source strength. There are several reasons why the source strength was not measured in those facilities. For example, 125I seeds are provided under the sterilized conditions; quality assurance by source suppliers is reliable; and there is not sufficient staff.The single-seed assay is regarded as an internationally standardized and the most reliable measurement method. Therefore, it is an essential measurement technique to ensure traceability of source strength measurements. However, our survey found that most Japanese facilities do not perform single-seed assays. Meanwhile, some facilities have performed batch assay as an alternative method, in which all of the multiple sources in a batch are measured while loaded into sterilized cartridges. Although the measurement by the batch assay is less accurate than the one by the single-seeded assay, the batch assay does not require re-sterilization of the source and can be performed quickly. It might be useful to detect unexpected errors such as differences in the number of sources and abnormalities in source strength.In this report, we will introduce several methods of source strength measurement that have been implemented in medical facilities. The quality assurance of 125I seed sources in prostate interstitial brachytherapy should be provided not only by the source suppliers but also by the medical facilities that use sources to treat patients. We hope that medical facilities will refer to this technical report and use it as an aid to quality assurance in their own facilities.