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Background: The treatment of recurrent tracheal adenoid cystic carcinoma (TACC), a rare pulmonary malignant tumor, typically involves bronchoscopic interventional therapy for patients ineligible for surgery or external radiotherapy. This report describes an innovative treatment approach for TACC, initially managed with interventional bronchoscopy and subsequently with a Y-shaped airway stent loaded with 125I seeds, following recurrence after 2 years. Case presentation: A 50-year-old man presented with intermittent coughing for 2 months and was admitted to the hospital after the discovery of TACC a month earlier. Preoperative bronchial artery embolization was performed to reduce the risk of bleeding, followed by bronchoscopic tumor resection in January 2017 using an electric loop at the base, complemented by argon plasma coagulation (APC) and cryotherapy. Although short-term outcomes were favorable, the long-term prognosis remained suboptimal. Due to tumor recurrence, airway tumor resection and implantation of the 125I seed stent were performed under bronchoscope guidance in early 2019. The stent was removed 5 months later. The patient tolerated the procedure well and exhibited no signs of relapse or progression during the 5-year postoperative follow-up period. This case illustrates the successful application of a stent loaded with 125I seeds for treating unresectable TACC. Conclusions: Treatment of TACC with a covered airway stent loaded with 125I seeds may be a safe, effective, and scalable method. [ABSTRACT FROM AUTHOR]

Bioimaging such as magnetic resonance is used to monitor atherosclerotic plaques consisting of foam cells, which are derived from macrophages that have ingested oxidized low-density lipoprotein (oxLDL). However, the current bioimaging techniques are not highly specific and sensitive in detecting foam cells, calling for the development of higher precision foam cell detection probes. Here, we investigated the utility of iodine-125-labeled oxLDL (125I-oxLDL) as a prototype radiotracer in the radioimaging of foam cells infiltrating atherosclerotic plaques. Mouse bone marrow-derived macrophages (BMDMs) were used to analyze oxLDL uptake. Atherosclerosis mouse model was injected with 125I-oxLDL and DiI-labeled oxLDL (DiI-oxLDL). Accumulation of 125I-oxLDL and DiI-oxLDL in foam cells infiltrating atherosclerotic plaques was examined using Oil Red O (ORO) staining, autoradiography, and fluorescent immunohistochemistry. BMDMs phagocytosed oxLDL/125I-oxLDL via CD36, but not LDL/125I-LDL. The radioactive signal from 125I-oxLDL phagocytosed by the BMDMs could be detected for at least 3 days. In atherosclerosis mouse model, atherosclerotic plaques formed in the aortic arches and valves. The radioactive signal of the injected 125I-oxLDL was detected in atherosclerotic plaques of the aortic arch, and its intensity was positively correlated with the lesion size. Furthermore, the DiI-oxLDL fluorescent signals were detected in foam cells accumulating in atherosclerotic plaques. Thus, we found that 125I-oxLDL can be used as a radiotracer in the radioimaging of foam cells in atherosclerotic plaques by autoradiography, suggesting its potential future applications in bioimaging methods such as single-photon emission computed tomography. [ABSTRACT FROM AUTHOR]

Stereotactic Brachytherapy Iodine-125 (SBT I-125) has been investigated by some studies for the treatment of lowgrade gliomas. We performed a meta-analysis to assess the efficacy and safety of SBT I-125 Brachytherapy for treatment of patients with Low-Grade Gliomas. PubMed, Cochrane, Web of Science, and EMBASE databases were searched for randomized and observational studies. This systematic review and meta-analysis was conducted according to the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement guidelines. We used relative risk (RR) with 95% confidence intervals and random effects model to compare the effects of I-125 SBT treatment on the interest outcomes. We evaluated heterogeneity using I2 statistics; we considered heterogeneity to be significant if the p-value was less than 0.05 and I2 was higher than 35%. We performed statistical analysis using the software R (version 4.2.3). A total of 20 studies with a cohort of 988 patients with low grade gliomas who received SBT I-125 as a treatment option. The pooled analysis evidenced: (1) Complication rate of 10% (95% CI: 7–12%; I² = 60%); (2) 5-year PFS of 66% (99% CI: 45-86%; I²= 98%); (3) 10-year PFS was 66% (99% CI: 45-86%; I²= 98%); (4) Malignant transformation rate of 26% (95% CI: 8–45%; I²=0); (5) Mortality of 33% (95% CI: 15–51%; I² = 0%). Our systematic review and meta-analysis of SBT I-125 for low-grade gliomas have revealed significant concerns regarding its safety and efficacy. Despite a proportion of patients remaining progression-free, elevated rates of complications and mortality cast doubt on the intervention's reliability. Future research should prioritize long-term follow-up studies, standardized protocols, and comparative effectiveness research. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to retrospectively assess the safety and efficacy of radioactive iodine-125 (I-125) seed implantation for liver malignancies in challenging locations. Materials and Methods: Between December 2015 and December 2021, 49 patients with 60 liver malignancies in challenging locations who underwent computed tomography (CT)-guided I-125 seed implantation were retrospectively analyzed. The primary endpoints included technical success rate and overall survival (OS), whereas the secondary endpoints included progression-free survival (PFS), disease control rate (DCR), objective response rate (ORR), and liver recurrence. Potential factors associated with liver recurrence were also evaluated. Results: The technical success rate was 100%. The median follow-up duration was 12 months (range, 2–68 months). The mean OS and PFS were 17.58 months (95% CI: 13.64–21.52 months) and 13.14 months (95% CI: 10.36–15.92 months), respectively. The 2-month, 6-month, and 1-year DCR and ORR were 97.96% and 93.88%, 93.75% and 77.08%, and 93.48% and 60.87%, respectively. The 6- and 12-month tumor recurrence rates were 20.41% and 28.26%, respectively. The Kaplan–Meier method was used to estimate the time of liver recurrence, with our results showing that patients with primary intrahepatic cholangiocarcinoma had an increased likelihood of having earlier liver recurrence. No major complications developed during follow-up. Conclusion: CT-guided radioactive I-125 implantation could be a safe and effective alternative with promising survival benefits and high local control rates for liver malignancies in challenging locations. [ABSTRACT FROM AUTHOR]

The incidence of pancreatic cancer is increasing worldwide. Approximately, 60% of patients with pancreatic cancer have distant metastases at the time of diagnosis, of which only 10% can be removed using standard resection. Further, patients derive limited benefits from chemotherapy or radiotherapy. As such, alternative methods to achieve local control have emerged, including permanent iodine-125 seed interstitial brachytherapy. In 2023, the Chinese College of Interventionalists, affiliated with the Chinese Medical Doctor Association, organized a group of multi-disciplinary experts to compose guidelines for this treatment modality. The aim of this conference was to standardize the procedure for permanent iodine-125 seed interstitial brachytherapy, including indications, contraindications, pre-procedural preparation, procedural operations, complications, efficacy evaluation, and follow-up. [ABSTRACT FROM AUTHOR]

Simple Summary: Brain metastases are cancerous growths that spread to the brain from other parts of the body, causing severe health problems. This review explores brachytherapy, a treatment where radioactive sources are placed directly into or near tumors or tumor beds to deliver targeted radiation, with the goal of minimizing damage to healthy brain tissue. Here, we aim to summarize the history and recent advancements of brachytherapy techniques and clinical outcomes in brain metastasis treatment, showcasing its benefits and limitations and providing a clearer understanding of how brachytherapy may potentially improve quality of life for patients with brain metastases. Brain metastases pose a significant therapeutic challenge in the field of oncology, necessitating treatments that effectively control disease progression while preserving neurological and cognitive functions. Among various interventions, brachytherapy, which involves the direct placement of radioactive sources into or near tumors or into the resected cavity, can play an important role in treatment. Current literature describes brachytherapy's capacity to deliver targeted, high-dose radiation while minimizing damage to adjacent healthy tissues—a crucial consideration in the choice of treatment modality. Furthermore, advancements in implantation techniques as well as in the development of different isotopes have expanded its efficacy and safety profile. This review delineates the contemporary applications of brachytherapy in managing brain metastases, examining its advantages, constraints, and associated clinical outcomes, and provides a comprehensive understanding of advances in the use of brachytherapy for brain metastasis treatment, with implications for improved patient outcomes and enhanced quality of life. [ABSTRACT FROM AUTHOR]

BackgroundThe treatment of recurrent tracheal adenoid cystic carcinoma (TACC), a rare pulmonary malignant tumor, typically involves bronchoscopic interventional therapy for patients ineligible for surgery or external radiotherapy. This report describes an innovative treatment approach for TACC, initially managed with interventional bronchoscopy and subsequently with a Y-shaped airway stent loaded with 125I seeds, following recurrence after 2 years.Case presentationA 50-year-old man presented with intermittent coughing for 2 months and was admitted to the hospital after the discovery of TACC a month earlier. Preoperative bronchial artery embolization was performed to reduce the risk of bleeding, followed by bronchoscopic tumor resection in January 2017 using an electric loop at the base, complemented by argon plasma coagulation (APC) and cryotherapy. Although short-term outcomes were favorable, the long-term prognosis remained suboptimal. Due to tumor recurrence, airway tumor resection and implantation of the 125I seed stent were performed under bronchoscope guidance in early 2019. The stent was removed 5 months later. The patient tolerated the procedure well and exhibited no signs of relapse or progression during the 5-year postoperative follow-up period. This case illustrates the successful application of a stent loaded with 125I seeds for treating unresectable TACC.ConclusionsTreatment of TACC with a covered airway stent loaded with 125I seeds may be a safe, effective, and scalable method.

To develop and validate risk models incorporating clinical and/or imaging parameters based on three-dimensional treatment-planning systems (3D-TPS) to predict the occurrence of 125I seed migration and the number of migrated seeds <2/≥2 to the chest after brachytherapy for patients with malignant hepatic tumors. A total of 480 patients diagnosed with malignant liver tumors receiving 125I seed brachytherapy from July 2010 to May 2020 were retrospectively enrolled. Variables included 3D-TPS-based CT parameters, that is, the distance from the seed to the inferior vena cava (DSI), the distance from the seed to the second hepatic portal (DSP) and the angle from the seed to the second hepatic portal (ASP), and patients' clinical characteristics, that is, the number of seed implantation procedures (NSP), the maximum number of implanted seeds one time (MAX) and laboratory parameters within 1 week before treatment. Two sets of logistic regression models incorporating clinical and/or imaging variables were developed to predict the occurrence of seed migration and the number of migrated seeds <2/≥2. Model performance was assessed by ROC analysis and decision curve analysis. Compared with the clinical models, the combined model showed a higher discriminative ability for both the prediction of migration occurrence and number of migrated seeds ≥ 2/<2 to the chest (AUC, 0.879 vs. 0.668, p < 0.05; 0.895 vs. 0.701, p < 0.05). The decision curve analysis results indicated higher net benefits of combined models than clinical models. Variables, including DSI, NSP and pretreatment lymphocyte-to-neutrophil ratio, acted as the most important predictors in combined models. The proposed combined models based on 3D-TPS improved discriminative abilities for predicting 125I seed migration and number of migrated seeds <2/≥2 to the chest after hepatic brachytherapy, being promising to aid clinical decision-making. [ABSTRACT FROM AUTHOR]

Therapeutic antibodies for reducing Aβ plaque load in Alzheimer’s disease (AD) is currently making rapid progress. The diagnostic imaging of Aβ plaque load in AD has been underway and is now used in clinical studies. Here, we report our preliminary findings on imaging a therapeutic antibody, Lecanemab, in a postmortem AD brain anterior cingulate. [125I]5-iodo-3-pyridinecarboxamido-Lecanemab ([125I]IPC-Lecanemab) was prepared by coupling N-succinimidyl-5-([125I]iodo)-3-pyridinecarboxylate with Lecanemab in modest yields. The distinct binding of [125I]IPC-Lecanemab to Aβ-rich regions in postmortem human AD brains was higher in grey matter (GM) containing Aβ plaques compared to white matter (WM) (GM/WM was 1.6). Anti-Aβ immunostaining was correlated with [125I]IPC-Lecanemab regional binding in the postmortem AD human brains. [125I]IPC-Lecanemab binding was consistent with the binding of Aβ small molecules, [18F]flotaza and [125I]IBETA, in the same subjects. [18F]Flotaza and [125I]IBETA, however, exhibited significantly higher GM/WM ratios (>20) compared to [125I]IPC-Lecanemab. Our results suggest that radiolabeled [125I]IPC-Lecanemab retains the ability to bind to Aβ in human AD and may therefore be useful as a PET imaging radiotracer when labeled as [124I]IPC-Lecanemab. The ability to directly visualize in vivo a promising therapeutic antibody for AD may be useful in treatment planning and dosing and could be complimentary to small-molecule diagnostic imaging to assess outcomes of therapeutic interventions.

Therapeutic antibodies for reducing Aβ plaque load in Alzheimer's disease (AD) is currently making rapid progress. The diagnostic imaging of Aβ plaque load in AD has been underway and is now used in clinical studies. Here, we report our preliminary findings on imaging a therapeutic antibody, Lecanemab, in a postmortem AD brain anterior cingulate. [125I]5-iodo-3-pyridinecarboxamido-Lecanemab ([125I]IPC-Lecanemab) was prepared by coupling N-succinimidyl-5-([125I]iodo)-3-pyridinecarboxylate with Lecanemab in modest yields. The distinct binding of [125I]IPC-Lecanemab to Aβ-rich regions in postmortem human AD brains was higher in grey matter (GM) containing Aβ plaques compared to white matter (WM) (GM/WM was 1.6). Anti-Aβ immunostaining was correlated with [125I]IPC-Lecanemab regional binding in the postmortem AD human brains. [125I]IPC-Lecanemab binding was consistent with the binding of Aβ small molecules, [18F]flotaza and [125I]IBETA, in the same subjects. [18F]Flotaza and [125I]IBETA, however, exhibited significantly higher GM/WM ratios (>20) compared to [125I]IPC-Lecanemab. Our results suggest that radiolabeled [125I]IPC-Lecanemab retains the ability to bind to Aβ in human AD and may therefore be useful as a PET imaging radiotracer when labeled as [124I]IPC-Lecanemab. The ability to directly visualize in vivo a promising therapeutic antibody for AD may be useful in treatment planning and dosing and could be complimentary to small-molecule diagnostic imaging to assess outcomes of therapeutic interventions. [ABSTRACT FROM AUTHOR]

Purpose: To report 6 cases of diffuse choroidal hemangioma in children treated with iodine-125 plaque brachytherapy at a single tertiary care center. Methods: Retrospective case series. Results: Six pediatric patients diagnosed with diffuse choroidal hemangioma were included in the study. Preplaque visual acuity ranged from 20/150 to no light perception. All patients had extensive serous retinal detachment at presentation. An iodine-125 radioactive plaque was placed on the affected eye to administer a dose of 34.2-42.1 Gy to the tumor apex over a median of 4 days. Tumor regression and subretinal fluid resolution were observed in all eyes within 17 months of treatment. Visual acuity improved in two patients. Radiation-induced cataract and subretinal fibrosis were documented in one case, and one patient developed radiation retinopathy. No patients developed neovascular glaucoma within the follow-up time of 12-65 months. Conclusion: Iodine-125 plaque radiotherapy is an effective option for diffuse choroidal hemangioma, although there is a risk for radiation-induced complications. [ABSTRACT FROM AUTHOR]

To investigate the safety and efficacy of iodine-125 seed implantation in the treatment of abdomen-thorax desmoid tumors (DTs). Data from 14 DT patients who received brachytherapy with iodine-125 seeds were retrospectively collected from 2014 to 2020. The operation was completed using CT guidance and the treatment plan system (TPS). The number of lesions and the target dosimetry parameters were recorded. After brachytherapy, the lesions were evaluated using response evaluation criteria in solid tumors (RECIST). Fourteen patients with 18 lesions were enrolled in this study; eleven lesions were in the thorax, seven were in the abdomen, and the lesion gross tumor volume (GTV) was 82.10 cc (interquartile range [IQR]: 40.37, 203.42 cc). The median number of seeds was 88 (IQR: 35, 158), and the median prescription dose was 120 Gy (IQR: 115, 120 Gy). The D 90 was 123 ± 16.7 Gy, the V 90 was 97% (IQR: 95.00, 97.25%), and the V 200 was 27% (IQR: 14.50, 33.00%). The median follow-up time for each lesion was 34 (IQR: 23, 67) months, and the local response rate was 100%. Following brachytherapy, the overall survival was 52.3 ± 30.72 months. One year after brachytherapy, one patient experienced persistent worsening of a brachial plexus injury; another received a ureteral stent. No brachytherapy-related complications were observed in the remaining patients. Iodine-125 brachytherapy is a novel treatment option for DT of the abdomen and thorax. Although it is a safe and effective treatment, the radiation dose of iodine-125 brachytherapy for DT-embedded organs at risk must be investigated further. [ABSTRACT FROM AUTHOR]

In conducting dosimetric assays of seed sources containing iodine-125 (125I), several major guidelines require the medical physicist to verify the source strength before patient treatment. Japanese guidelines do not mandate dosimetric assays at medical facilities, but since 2017, three incidents have occurred in Japan wherein seeds with incorrect strengths were delivered to medical facilities. Therefore, this study aimed to survey the current situation and any barriers to conducting the dosimetric assay of iodine-125 seeds at medical facilities in Japan. We conducted a questionnaire-based survey from December 2020 to April 2021, to examine whether seed assay and verification of the number of seeds delivered were being performed. We found that only 9 facilities (16%) performed seed assay and 28 (52%) verified the number of seeds. None of the facilities used an assay method that ensured traceability. The reasons for not performing an assay were divided into two categories: lack of resources and legal issues. Lack of resources included lack of instruments, lack of knowledge of assay methods, shorthand, or all of the above, whereas legal issues included the inability to resterilize iodine-125 seeds distributed in Japan and/or purchase seeds dedicated to the assay. Dosimetric assays, including simple methods, are effective in detecting calibration date errors and non-radioactive seeds. The study findings suggest that familiarization of medical personnel with these assay methods and investigation of the associated costs of labor and equipment should be recommended, as these measures will lead to medical reimbursement for quality assurance. [ABSTRACT FROM AUTHOR]

Aim: Describe the results of brachytherapy in the prevention of recurrences in conjunctival melanoma (CM) and describe a dosimetric protocol. Methods: Retrospective and descriptive case report. Eleven consecutive patients with a confirmed histopathological diagnosis of CM treated with brachytherapy between 1992 and 2023 were reviewed. Demographic, clinical, and dosimetric characteristics as well as recurrences were recorded. Quantitative variables were represented by the mean, median, and standard deviation, and qualitative variables by frequency of distribution. Results: Of a total of 27 patients diagnosed with CM, 11 who were treated with brachytherapy were included in the study (7 female; mean age at time of treatment: 59.4 years). Mean follow-up was 58.82 months (range 11–141 months). Of a total of 11 patients, 8 were treated with ruthenium-106 and 3 with iodine-125. Brachytherapy was performed in 6 patients as adjuvant therapy after biopsy-proven CM on histopathology and in the other 5 patients after recurrence. The mean dose was 85 Gy in all cases. Recurrences outside of the previously irradiated area were observed in 3 patients, metastases were diagnosed in 2 patients, and one case of an ocular adverse event was reported. Conclusion: Brachytherapy is an adjuvant treatment option in invasive conjunctival melanoma. In our case report, only one patient had an adverse effect. However, this topic requires further research. Furthermore, each case is unique and should be evaluated by experts in a multidisciplinary approach involving ophthalmologists, radiation oncologists, and physicists. [ABSTRACT FROM AUTHOR]

Lung cancer is the second most common, and the deadliest, disease globally. Because it is often diagnosed late, surgical resection is not a viable treatment option for ∼75 % of patients, often resulting in a poor prognosis. Of the available treatments, radioactive iodine-125 (125-I) seed implantation therapy, or brachytherapy, has emerged as a promising option. In this procedure, small radioactive seeds are implanted inside tumor cells to produce sustained effects. Because of the short radial distance of this radiation, 125-I brachytherapy selectively and efficiently kills cancer cells while minimizing injury to adjacent cells. The present review describes the mechanism of 125-I seed implantation in the treatment of lung cancer, its efficacy and safety, and its combination with other therapies. We conclude that radioactive 125-I seed implantation and its use in combination with other therapies are good options for the management of local tumor growth, pain palliation, and improving the life span of patients suffering from lung cancers. This technique can enhance the clinical efficacy of treatment and improve the overall survival of patients with lung cancers. However, standardized dosage regimens and other procedures are still required to achieve treatment homogeneity and provide guidance for the clinical implementation of this technique.

Portal vein tumor thrombus (PVTT) seriously reduces the survival of patients with hepatocellular carcinoma (HCC). CT-guided iodine-125 (125I) brachytherapy has the advantage of a high local control rate and is minimally invasive. This study aims to evaluate the safety and efficacy of 125I brachytherapy for treating PVTT in HCC patients. Thirty-eight patients diagnosed with HCC complicated with PVTT and treated with 125I brachytherapy for PVTT were included in this retrospective study. The local tumor control rate, local tumor progression-free survival, and overall survival (OS) were analyzed. Cox proportional hazards regression analysis was performed to identify predictors affecting survival. The local tumor control rate was 78.9% (30/38). The median local tumor progression-free survival was 11.6 (95% confidence interval [ CI ]: 6.7, 16.5) months, and the median overall survival was 14.5 (95% CI : 9.2, 19.7) months. Multivariate Cox analysis showed that age <60 years (hazard ratio [ HR ] = 0.362; 95% CI : 0.136, 0.965; p = 0.042), type I+II PVTT (HR = 0.065; 95% CI : 0.019, 0.228; p < 0.001), and tumor diameter <5 cm (HR = 0.250; 95% CI : 0.084, 0.748; p = 0.013) were significant predictors of OS. There were no serious adverse events related to 125I seed implantation during the follow-up period. CT-guided 125I brachytherapy is effective and safe for treating PVTT of HCC, with a high local control rate and no severe adverse events. Patients younger than 60 years old with type I+II PVTT and a tumor diameter less than 5 cm have a more favorable OS. • The prognosis of HCC patients with PVTT is poor, and PVTT is the factor limiting current treatment. • 125I brachytherapy has a high LTCR in HCC patients with PVTT. • Patients aged <60 years, with type I+II PVTT, and with a tumor diameter <5 cm have a more favorable OS. • 125I brachytherapy is safe for treating PVTT of HCC. [ABSTRACT FROM AUTHOR]

La cirugía radioguiada emplea fuentes radioactivas para identificar y extirpar lesiones de difícil localización. Los tumores mesenquimales constituyen un grupo heterogéneo de neoplasias derivados del mesodermo, incluyendo lesiones benignas y sarcomas malignos. El objetivo de este estudio fue evaluar la capacidad de la semilla radioactiva de 125I para guiar la localización intraoperatoria de tumores mesenquimales, analizando sus tasas de complicación y evaluando los márgenes de las piezas quirúrgicas recuperadas. Estudio observacional retrospectivo de todos los pacientes consecutivos sometidos a cirugía radioguiada de un tumor mesenquimal con semilla radioactiva de 125I desde enero de 2012 hasta enero de 2020 en un centro de referencia terciario en España. La semilla fue insertada mediante punción percutánea guiada con ecografía o tomografía computarizada de forma ambulatoria. Se extirparon 15 lesiones en 11 cirugías a 11 pacientes, recuperando todas las lesiones marcadas (100%) con semilla de 125I. Las lesiones incluyeron áreas de fibrosis benigna (26,7%), angiofibroma celular (6,7%), tumor desmoide (20%), tumor fibroso solitario (13,3%), condrosarcoma (6,7%) y sarcoma pleomórfico (26,7%), con una tasa elevada de tumores recurrentes (60%). Solo hubo una complicación (6,7%) por caída de la semilla dentro del lecho quirúrgico. Según la clasificación de la Union for International Cancer Control de tumor residual, el 80% de las lesiones resultaron en una resección R0, el 6,7% fueron una resección R1 y el 13,3% fueron una resección R2. La cirugía radioguiada fue una técnica precisa para la extirpación de tumores mesenquimales de difícil localización. Radioguided 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 the 125I radioactive seed to guide intraoperative localization of mesenchymal tumors, analyzing its complication rates and evaluating the margins of the surgical specimens retrieved. Retrospective 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 on an outpatient setting. Fifteen lesions were removed in 11 surgeries on 11 patients, recovering all marked lesions (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 tumor, 80% of the lesions resulted in an R0 resection, 6.7% were an R1 resection, and 13.3% were an R2 resection. Radioguided surgery was a precise technique for the removal of hard-to-locate mesenchymal tumors. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to examine the usefulness of seed density as a predictor of seed migration in patients with prostate cancer who received brachytherapy using Iodine-125 loose seed. Methods: From May 2006 to April 2016, 320 patients with localized prostate cancer underwent transperineal brachytherapy using iodine-125 loose seeds. Among them, 202 (63.1%) patients received brachytherapy monotherapy and 118 (36.9%) received combined brachytherapy and external beam radiotherapy. Seed density was calculated using the following formula: seed density = implanted seed number/prostate volume. All patients underwent radiography of the chest, abdomen and pelvis, and computed tomography at 1 day, 1 month, and 1 year after brachytherapy to evaluate the presence of seed migration. Results: In total, the number of implanted seeds was 21,876. Seed migration was detected in 92 (28.8%) patients. Of a total of 21,876 seeds, 144 (0.66%) showed migration. The number of needles, number of seeds, and seed density were significantly higher in the group with migration than in the group without migration (p = 0.05). The ROC cutoff values for prostate volume, number of needles, number of seeds, and seed density were 20.9 cc, 21, 65, and 3.0, respectively. In the univariate analysis, prostate volume, number of needles, number of seeds, seed density, and treatment modality were all significant factors in predicting migration (p = 0.05). In the multivariate analysis, seed density and treatment modality were significant factors in predicting migration (p = 0.05). Conclusion: Seed density is useful for predicting seed migration. In cases with seed density > 3.0, it is necessary to take measures such as considering the use of stranded seeds.

This work focuses on the synthesis and preliminary biological evaluation of [125I]iodoprocainamide ([125I]iodoPA) as a potential heart-imaging agent. [125I]iodoPAwas synthesized by procainamide labeling with [125I]iodide in high radiochemical yield and high radiochemical purity of both ≥98%. These results were obtained under optimized reaction conditions using chloramine-T as oxidizing agent within 30 min incubation period at pH 8 and 37°C reaction temperature. Ahigh uptake of 37.33 ± 0.15 percentage injected dose/g organ (%ID/ g) was found in the heart which confirmed the suitability of [125I]iodoPA as a potential radiotracer for heart imaging. [ABSTRACT FROM AUTHOR]

Aim: To investigate the role of iodine‐125 (125I) combined with epirubicin (EPI) in inhibiting hepatocellular carcinoma (HCC) growth and promoting apoptosis. Methods: Both in vivo and in vitro experiments were conducted. CCK‐8 assay was performed to determine the cells viability after EPI treatment. HepG2 and SMMC7721 cells were treated with EPI or 125I or in combination. Colony formation assays were performed to verify the antiproliferation effect. Annexin V–FITC/PI, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, and western blotting were performed to analyze cellular apoptosis. Scratch wound healing assays and transwell assays were used to examine migration following different treatments. An isobaric tag for relative and absolute quantitation analysis was used to detect changes in protein expression after 125I treatment, identifying the potential mediating protein cathelicidin (LL‐37). LL‐37 protein and WNT pathway‐related proteins were detected by western blotting in SMMC7721 and HepG2 cells. Mice were treated with 125I and EPI to evaluate whether EPI enhanced the antitumor effect of 125I. Results: EPI promoted 125I‐induced apoptosis and reduced the proliferation of HepG2 and SMMC7721 cells. EPI also prevented the migration of HepG2 and SMMC7721 cells. EPI combined with 125I may interfere with the WNT signaling pathway by decreasing LL‐37 to inhibit HCC development. The antitumor effects of EPI with 125I were verified in mice. Conclusion: EPI combined with 125I induced apoptosis and inhibited the proliferation of HCC cells by LL‐37 downregulating the WNT pathway. [ABSTRACT FROM AUTHOR]

Objectives: Orbital lymphoma is one of the most common adult orbital malignancies, accounting for approximately 10% of all orbital tumors. This study aimed to analyze the effects of surgical resection and orbital iodine-125 brachytherapy implantation for orbital lymphoma. Patients and methods: This was a retrospective study. Clinical data of 10 patients were collected from October 2016 to November 2018 and followed up to March 2022. Patients underwent the primary surgery for maximal safe removal of the tumor. After a pathologic diagnosis of a primary orbital lymphoma was established, iodine-125 seed tubes were designed based on the tumor size and invasion range, and direct vision was placed into the nasolacrimal canal or/and under the orbital periosteum around the resection cavity during the secondary surgery. Then, follow-up data, including the general situation, ocular condition, and tumor recurrence, were recorded. Results: Of the 10 patients, the pathologic diagnoses included extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (6 cases), small lymphocytic lymphoma (1 case), mantle cell lymphoma (2 cases), and diffuse large B-cell lymphoma (1 case). The number of seeds implanted ranged from 16 to 40. The follow-up period ranged between 40 and 65 months. All patients in this study were alive and well had tumors that were completely controlled. No tumor recurrences or metastases occurred. Three patients had dry eye syndrome and two patients had abnormal facial sensation. No patient had radiodermatitis involving the skin around the eye, and no patient had radiation-related ophthalmopathy. Conclusions: Based on preliminary observations, iodine-125 brachytherapy implantation appeared to be a reasonable alternative to external irradiation for orbital lymphoma. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer associated with a poor prognosis. ICC accounts for about 10% of primary liver malignancies but with increasing incidence in recent years. Recently, some studies suggested that minimally interventional therapy can be used in the treatment of ICC. However, there are few references on interventional therapy for the clinical treatment of ICC. Herein we reported a case of a 48-year-old man who suffered from ICC. The patient was diagnosed with ICC by computerized tomography scan and pathological biopsy. The patient was completely cured by minimally interventional therapy with iodine-125 seed implantation. These results provide an important reference for the treatment option of ICC.

Aim: This study aimed to examine the usefulness of seed density as a predictor of seed migration in patients with prostate cancer who received brachytherapy using Iodine-125 loose seed. Methods: From May 2006 to April 2016, 320 patients with localized prostate cancer underwent transperineal brachytherapy using iodine-125 loose seeds. Among them, 202 (63.1%) patients received brachytherapy monotherapy and 118 (36.9%) received combined brachytherapy and external beam radiotherapy. Seed density was calculated using the following formula: seed density = implanted seed number/prostate volume. All patients underwent radiography of the chest, abdomen and pelvis, and computed tomography at 1 day, 1 month, and 1 year after brachytherapy to evaluate the presence of seed migration. Results: In total, the number of implanted seeds was 21,876. Seed migration was detected in 92 (28.8%) patients. Of a total of 21,876 seeds, 144 (0.66%) showed migration. The number of needles, number of seeds, and seed density were significantly higher in the group with migration than in the group without migration (p = 0.05). The ROC cutoff values for prostate volume, number of needles, number of seeds, and seed density were 20.9 cc, 21, 65, and 3.0, respectively. In the univariate analysis, prostate volume, number of needles, number of seeds, seed density, and treatment modality were all significant factors in predicting migration (p = 0.05). In the multivariate analysis, seed density and treatment modality were significant factors in predicting migration (p = 0.05). Conclusion: Seed density is useful for predicting seed migration. In cases with seed density > 3.0, it is necessary to take measures such as considering the use of stranded seeds. [ABSTRACT FROM AUTHOR]

To investigate the consistency between preoperative and postoperative dosimetry when 125I brachytherapy for brain tumors is performed with magnetic resonance (MR) guidance and a three-dimensional non co-planar template (3DNPT). Thirty patients with brain tumors (metastatic or gliomas) underwent radioactive 125I seed implantation. A preoperative treatment plan was determined with MR imaging, and the operation was done under 3DNPT assistance and MR guidance. The dosimetry was verified postoperatively based on postoperative CT–MR fusion images. Postoperative dosimetric parameters and implant quality indices were defined and compared with those in the preoperative treatment plan. Furthermore, a comparison of preoperative and postoperative doses to normal brain tissues and organs at risk was also performed. All mean postoperative dosimetries were calculated. Target coverage parameters D90, D100, %CTV100, %CTV150, and %CTV200 were 143.6 cGy, 76.6 cGy, 88.2%, 63.1%, and 41.4%, respectively. The values of implant quality indices CI, EI, and HI were 0.75, 0.14, and 0.28, respectively. No significant differences between most preoperative and postoperative dosimetric parameters were found (p > 0.05). The differences were also insignificant for organs at risk. Postoperative %CTV150 and %CTV200 were higher than the preoperative, whereas postoperative HI was significantly lower than in the treatment plan. Magnetic resonance guidance combined with 3DNPT allows accurate positioning and direction in 125I brachytherapy for brain tumors. However, seed distribution and dose homogeneity require further improvement. [ABSTRACT FROM AUTHOR]

Purpose: Radioguided localization can assist the surgery of hard-to-find lesions. The aim was to evaluate the results of the 125I Radioactive Seed Localization (RSL) technique to guide a margin-free tumoral resection of mesenchymal tumours compared to conventional surgery and its influence in oncological outcomes. Methods: Retrospective observational study of all consecutive patients who underwent 125I RSL for the surgery of a mesenchymal tumour from January 2012 to January 2020 in a tertiary referral centre in Spain. The control group was formed by patients with conventional surgery in the same period and centre. A Propensity Score matching at 1:4 ratio selected the cases for analysis. Results: A total of 10 lesions excised in 8 radioguided surgeries were compared to 40 lesions excised in 40 conventional surgeries, with equal proportion of histological subtypes in each group. There was a higher proportion of recurrent tumours in the RSL group (80 % [8/10] vs. 27.5 % [11/40]; p: 0.004). An R0 was achieved in 80 % (8/10) of the RSL group and 65 % (26/40) of the conventional surgery group. The R1 rate was 0 % and 15 % (6/40), and the R2 rate was 20 % (2/10 and 8/40) in the RSL group and conventional surgery group, respectively (p: 0.569). No differences were detected in disease-free or overall survival between the different histological subtypes in the subgroup analysis. Conclusion: The 125I RSL technique of a challenging sample of mesenchymal tumours achieved a similar margin-free tumoral resection and oncological outcomes as conventional surgery. [ABSTRACT FROM AUTHOR]

Radioiodinated imaging agents for Aβ amyloid plaque imaging in Alzheimer's disease (AD) patients have not been actively pursued. Our previous studies employed the "diaza" derivatives [11C]TAZA and [18F]flotaza in order to develop successful positron emission tomography (PET) imaging agents for Aβ plaques. There is a need for radioiodinated imaging agents for Aβ plaques for single photon emission computed tomography (SPECT) and PET imaging. We report our findings on the preparation of [124/125I]IAZA, a "diaza" analog of [11C]TAZA and [18F]flotaza, and the evaluation of binding to Aβ plaques in the postmortem human AD brain. The binding affinity of IAZA for Aβ plaques was Ki = 10.9 nM with weak binding affinity for neurofibrillary tangles (Ki = 3.71 μM). Both [125I]IAZA and [124I]IAZA were produced in >25% radiochemical yield and >90% radiochemical purity. In vitro binding of [125I]IAZA and [124I]IAZA in postmortem human AD brains was higher in gray matter containing Aβ plaques compared to white matter (ratio of gray to white matter was >7). Anti-Aβ immunostaining strongly correlated with [124/125I]IAZA in postmortem AD human brains. The binding of [124/125I]IAZA in postmortem human AD brains was displaced by the known Aβ plaque imaging agents. Thus, radiolabeled [124/123I]IAZA may potentially be a useful PET or SPECT radioligand for Aβ plaques in brain imaging studies. [ABSTRACT FROM AUTHOR]

Auger emitters exhibit interesting features due to their emission of a cascade of short-range Auger electrons. Maximum DNA breakage efficacy is achieved when decays occur near DNA. Studies of double-strand breaks (DSBs) yields in plasmids revealed cutoff distances from DNA axis of 10.5 Å–12 Å, beyond which the mechanism of DSBs moves from direct to indirect effects, and the yield decreases rapidly. Some authors suggested that the average energy deposited in a DNA cylinder could explain such cutoffs. We aimed to study this hypothesis in further detail. Using the Monte Carlo code CELLDOSE, we investigated the influence of the 125I atom position on energy deposits and absorbed doses per decay not only in a DNA cylinder, but also in individual strands, each modeled as 10 spheres encompassing the fragility sites for phosphodiester bond cleavage. The dose per decay decreased much more rapidly for a sphere in the proximal strand than for the DNA cylinder. For example, when moving the 125I source from 10.5 Å to 11.5 Å, the average dose to the sphere dropped by 43%, compared to only 13% in the case of the cylinder. Explaining variations in DSBs yields with 125I position should consider the probability of inducing damage in the proximal strand (nearest to the 125I atom). The energy received by fragility sites in this strand is highly influenced by the isotropic (4π) emission of 125I low-energy Auger electrons. The positioning of Auger emitters for targeted radionuclide therapy can be envisioned accordingly. [ABSTRACT FROM AUTHOR]

Ionizing radiation causes various types of DNA damage e.g. single strand breaks (SSB) and double strand breaks (DSB), whereby the SSB/DSB ratio is shifted toward the DSB with increasing LET. For the DNA-incorporated Auger electron emitter Iodine-125 a SSB/DSB ratio of 5.4:1 is calculated based on computer simulations. In the presented work the SSB/DSB ratio of DNA-incorporated Iodine-125 was experimentally determined and compared to external homogenous γ-irradiation. Iodine-125-iododeoxyuridine (I-125-UdR) was incorporated into the DNA of SCL-II cells and cells were subsequently frozen for decay accumulation. Accordingly, external γ-irradiation (Cs-137) experiments were performed in frozen cells. After exposure the neutral or alkaline Comet Assay was performed to quantify DSB or DSB and SSB, respectively. Automated quantification of the comets was performed using the Olive Tail Moment (Metafer CometScan; MetaSystems). Calculation of absorbed dose for Auger electrons on cellular level is extremely biased due to the exclusive DNA localization of I-125-UdR. To avoid dose calculation the γ-H2AX assay was used in order to allow the comparison of the Comet Assay data between both investigated radiation qualities. For low-LET γ-radiation, a SSB/DSB ratio of 10:1 was determined. In contrast, a lower SSB/DSB ratio of 6:1 was induced by DNA-incorporated Iodine-125 which compares very well to the calculated values of Pomplun and co-authors DNA-incorporated Iodine-125 induces a high-LET type DNA damage pattern in respect to SSB/DSB ratio. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study is to evaluate the safety and efficacy of iodine-125 brachytherapy for newly diagnosed brain metastasis in patients with non-small cell lung cancer (NSCLC). Materials and methods: The study included 158 NSCLC patients diagnosed with brain metastasis from December 2003 to August 2017. Ninety-nine patients underwent external beam radiotherapy (EBRT group), and 59 patients received iodine-125 brachytherapy (125I group). In addition, the 6- and 12-month progression-free survival (PFS) rates and the 12- and 24-month overall survival (OS) rates were compared between the EBRT group and the 125I group. Median OS and PFS were analyzed using the Kaplan−Meier method with a log-rank test. Results: The 6-month PFS rate was significantly higher in the 125I group (p = 0.002) than in the EBRT group, while no differences were found in the 12- month PFS rate (p = 0.184). Additionally, the 12- (p = 0.839) and 24-month (p = 0.284) OS rates were not significantly different between the two groups. No significant differences in median OS (p = 0.525) or PFS (p = 0.425) were found between the two groups. Conclusions: Iodine-125 brachytherapy is an alternative therapy for patients unable to undergo surgical resection. [ABSTRACT FROM AUTHOR]

The Hemi-Ablative Prostate Brachytherapy (HAPpy) trial evaluated hemi-gland (HG) low-dose-rate prostate brachytherapy (LDR-PB) as a focal approach to control unilateral localized prostate cancer and reduce treatment-related toxicity at 2-years postimplant. Herewith we present further outcomes with a minimum of 5 years post-implant follow-up. Outcomes of 30 HG implants and 362 whole-gland (WG) brachytherapy controls were monitored with IPSS, urinary Quality-of-Life (QoLU), GI component of EORTC-PR25 (QoLB), and IIEF-5 instruments, and PSA values. The median (range) follow-up for HG and WG cases was 72 (60–96) months and 84 (24–144) months respectively. The IPSS was significantly reduced in HG relative to WG patients and trends indicating improved bowel QoL and erectile function were observed. The mean of change in PSA from baseline to last follow-up was -5.6 and -6.5 in HG and WG respectively (p = 0.1). The mean time to nadir was 4.2 and 4.8 years in HG and WG respectively (p = 0.06). Over time PSA in HG patients mirrored the sustained decline observed in WG cases but levels were higher by an average 0.5 ng/ml over WG controls (p < 0.001). Treatment failure occurred in 2 (6.7%) HG patients and in 20 (5.5%) WG cases. Five-year relapse-free survival was 97% in both groups (p = 0.7). At 5 years postimplant HG LDR-PB was as effective as WG treatment for control of unilateral localized prostate cancer with moderate improvement in treatment-related symptoms. Importantly, PSA is a valuable marker to assess disease control in this form of focal therapy. [ABSTRACT FROM AUTHOR]

A method of iodine-125 deposition on a surface of microsource silver supports for brachytherapy of prostate cancer was reported, which includes preparing the support surface by sequentially treating them with nitric acid and thiourea solutions, followed by chlorination of the support surface with a chlorinating agent to form silver chloride on the support surface, and substitution of chlorine atoms for 125I atoms by placing supports containin silver chloride on the surface in a solution with 125I ions to create a 125I layer on the support surface. The method described allows fixing 125I on supports with a low activity distribution on each activity-carrying support. [ABSTRACT FROM AUTHOR]

Objectives: To determine if dynamic CT can differentiate local progression from radioactive seed-induced peritumoral reaction (RSIPR) after brachytherapy with iodine-125 radioactive seeds (BIRS) for advanced hepatic malignancies.Methods: Enhanced CT images of seed-implanted lesions between 2006 and 2018 were retrospectively evaluated. Hounsfield units of peritumoral parenchyma were measured and assessed quantitatively. The classification, conversion, consequences, and serological indicators during follow-up were recorded and quantified. Statistical differences were analyzed using a Pearson χ2 test.Results: RSIPR was observed in 201 of 290 (69.3%) lesions (161 patients; median age, 55 years; range, 26-79 years), while local progression occurred in 53 lesions. The low density of local progression was much lower than that of RSIPR (p < 0.001), and the former did not exhibit iso-/high density in the portal or equilibrium phase. Ring-like enhancement in progressive lesions was also quite different from RSIPR. Local progression rate was lower for lesions with RSIPR than for those without RSIPR (14.9% vs 25.8%; p = 0.03), and their doses were different (397.2 Gy vs 120.3 Gy, p < 0.001).Conclusions: Radioactive seed-induced peritumoral reaction has characteristic manifestations on CT images, which is associated with a higher dose of lesions and lower local progression rate. Notably, the enhancement pattern of local progression was distinct from RSIPR and was clearly distinguishable on dynamic-enhanced CT.Key Points: • Radioactive seed-induced peritumoral reaction after brachytherapy with 125I seeds for liver malignancies has characteristic manifestations on CT images, which is associated with a higher dose of lesions (397.2 Gy vs 120.3 Gy, p < 0.001), as a focal radiation injury. • Lesions with RSIPR were less likely to develop local progression, while those without RSIPR had a higher rate of local progression (14.9% vs 25.8%; p = 0.03). • The enhancement pattern of local progression after brachytherapy was distinct from radioactive seed-induced peritumoral reaction and was clearly distinguishable on dynamic-enhanced CT. [ABSTRACT FROM AUTHOR]

The alpha particle-emitting radionuclide astatine-211 (211At) is of interest for targeted radiotherapy; however, low in vivo stability of many 211At-labeled cancer-targeting molecules has limited its potential. As an alternative labeling method, we evaluated whether a specific type of astatinated aryl compound that has the At atom in a higher oxidation state might be stable to in vivo deastatination. In the research effort, para-iodobenzoic acid methyl ester and dPEG4-amino acid methyl ester derivatives were prepared as HPLC standards. The corresponding para-stannylbenzoic acid derivatives were also prepared and labeled with 125I and 211At. Oxidization of the [125I]iodo- and [211At]astato-benzamidyl-dPEG4-acid methyl ester derivatives provided materials for in vivo evaluation. A biodistribution was conducted in mice with coinjected oxidized 125I- and 211At-labeled compounds. The oxidized radioiodinated derivative was stable to in vivo deiodination, but unfortunately the oxidized [211At]astatinated benzamide derivative was found to be unstable under the conditions of isolation by radio-HPLC (post animal injection). Another biodistribution study in mice evaluated the tissue concentrations of coinjected [211At]NaAtO3 and [125I]NaIO3. Comparison of the tissue concentrations of the isolated material from the oxidized [211At]benzamide derivative with those of [211At]astatate indicated the species obtained after isolation was likely [211At]astatate. [ABSTRACT FROM AUTHOR]

Colorectal cancer liver metastasis (CCLM) in anatomically challenging locations is difficult to treat. This retrospective study aimed to evaluate the effectiveness and safety of permanent 125I seeds implantation (ISI) for treatment of CCLM in anatomically challenging locations after failure of systemic chemotherapy. A total of 31 liver metastases (in 25 patients) were treated by ISI under computerized tomography guidance from January 2011 to December 2017. Post-treatment follow-up was for 40 months. Adverse events were classified using the National Cancer Institute's Common Terminology Criteria for Adverse Events. Tumor response was evaluated by the mRECIST criteria. Objective response rate, overall survival rate, and complications were retrospectively analyzed. All ISI procedures were performed successfully. Most patients only complained of fatigue and mild pain after ISI. Only one patient had liver rupture during the procedure. Serum alanine aminotransferase and aspartate aminotransferase levels at 1 month after ISI were not significantly different from pre-procedure levels (p > 0.05). Computed tomography at 6 months after ISI treatment showed completed response in 11 (11/31, 35.5%) lesions, partial response in 14 (14/31, 45.2%) lesions, stable disease in 4 (4/31, 12.9%) lesions, and disease progression in 2 (2/31, 6.5%) lesions; thus, the objective response rate was 80.6%. Median survival was for 12 months. The 1 and 2 year overall survival rates were 52.0% and 20.0%, respectively. 125I seeds implantation for CCLM in anatomically challenging locations is safe and effective. Survival benefit is limited in the salvage setting where patients have high intrahepatic tumor load after failed systemic chemotherapy. [ABSTRACT FROM AUTHOR]

Purpose: The pH (low) insertion peptide (pHLIP) family can target the tumor microenvironment (TME). If pHLIP can be labeled with radioiodine, the imaging and treatment of tumors can be considered. However, tyrosine and tryptophan can bind with iodine in the insertion region of pHLIP, and radioiodine labeling may affect the formation of α-helix structures in acidic environments; therefore, it is necessary to adjust the structure of pHLIP. This study aims to develop an 125I-labeled pH (low) insertion peptide variant 7-like peptide (pHLIP (Var7) LP) for imaging the TME in MDA-MB-231 triple-negative breast cancer (TNBC) xenograft tumor models.Procedures: Based on pHLIP (Var7), a new peptide sequence, pHLIP (Var7) LP, was obtained by the sequence modification method and then characterized. The binding of pHLIP (Var7) LP to MDA-MB-231 cells was analyzed. pHLIP (Var7) LP was labeled with 125I by the iodogen iodination method. Serial biodistribution studies and small-animal single photon emission computed tomography (SPECT)/computed tomography (CT) imaging in subcutaneous MDA-MB-231 TNBC-bearing mice were performed using [125I] I-pHLIP (Var7) LP.Results: A novel peptide, pHLIP (Var7) LP, has the characteristics of an α-helix structure, electronegativity, and amphiphilicity. Circular dichroism (CD) spectroscopy showed that the peptide presented a typical pH-dependent transition from an unstructured conformation to an α-helix structure when the pH was reduced from 8.0 to 4.0. The relative fluorescence intensities of 5-carboxytetramethylrhodamine (5-TAMRA)-pHLIP(var7) LP at pH = 6.0, 6.6, and 7.4 were 100.00 ± 5.98%, 72.10 ± 4.65%, and 13.72 ± 1.41%, respectively. The distribution of [125I] I-pHLIP (Var7) LP in tumors reached the highest level (8.7 ± 1.6% ID/g) at 2 h after injection, and the tumor-to-muscle ratios and tumor-to-blood ratios increased with time. Of the measured off-target organs, the stomach, kidney, and bladder showed higher uptake levels. SPECT imaging revealed rapid and sustained tumor uptake of [125I] I-pHLIP (Var7) LP in breast cancer-bearing mice.Conclusions: This study showed that [125I]I-pHLIP (Var7)LP had rapid and sustained tumor uptake in MDA-MB-231 TNBC and provided a new method for TNBC imaging and further treatment. [ABSTRACT FROM AUTHOR]

Abstract Background Treatment for radioiodine refractory differentiated thyroid carcinoma (RR-DTC) is challenging. The purpose of this study was to assess the efficacy and safety of ultrasound-guided implantation of radioactive 125I-seed in radioiodine refractory differentiated thyroid carcinoma. Methods Thirty-six cervical metastatic lymph nodes (CMLNs) diagnosed with RR-DTC from 18 patients were enrolled in this retrospective study. US and contrast-enhanced ultrasound (CEUS) examinations were performed before implantation. Follow-up comprised US, CEUS, thyroglobulin (Tg) level and routine hematology at 1–3, 6, 9 and 12 months and every 6 months thereafter. The volumes of the nodules were compared before implantation and at each follow-up point. The volume reduction rate (VRR) of nodules was also recorded. Results The median volume of the nodules was 523 mm3 (148, 2010mm3) initially, which decreased significantly to 53mm3 (0, 286mm3) (P

Abstract Background 125I seed implantation has been found to show good therapeutic effects on tumors. Recent studies showed that three-dimensional (3D) print template-assisted 125I seed implantation can optimize radiation dose distribution. This study aimed to compare the dose distribution differences in 125I seed implantation among 3D print noncoplanar template- (3DPNCT), 3D print coplanar template- (3DPCT) assisted implantation and traditional free-hand implantation. Methods We systematically searched the PubMed, EMbase, Cochrane Library, Wan Fang Med Online, China National Knowledge Infrastructure (CNKI) from the earliest to November 2020 without time or language restrictions. And the references of primary literature were also searched. The outcome measures were dosimetry and operation time. This meta-analysis was carried out using Stata 12.0. Results A total of 16 original articles were selected for inclusion. The differences of D90, D100, V90, and V100 values pre- and post-implantation with traditional free-hand implantation showed statistically significant (p 0.05). Compared with traditional free-hand implantation without any templates, 3D print template could improve postoperative D90 (Standard mean difference, SMD = 0.67, 95% confidence interval (CI) = 0.35 to 0.98, p 0.05). However, in 3DPNCT group, V150 and V200 were increased (SMD = 0.35, 0.49; 95%CI = 0.04 to 0.67, 0.02 to 0.96; p = 0.028, 0.043); the number of through bone needles was reduced (SMD = − 1.03, 95%CI = − 1.43 to − 0.64, p

Abstract Background The treatment of recurrent mediastinal lymph node metastasis (MLNMs) is challenging. We conducted this study to evaluate the effectiveness and safety of computed tomography (CT)‐guided percutaneous iodine‐125 brachytherapy for MLNMs. Methods We retrospectively analyzed 33 patients with recurrent MLNMs treated with CT‐guided interstitial implantation of iodine‐125 seeds. Regular contrast‐enhanced CT was conducted to evaluate the tumor response. Follow‐up survival, quality of life, and adverse events were analyzed. Results The number of implanted seeds was 16–85 (median, 40). The matched peripheral dose was 110–160 Gy. The patients were followed up for 5–24 months (median, 14 months). At the last follow‐up or death, complete response to therapy was achieved in 11 patients (33.3%) and partial response in 18 patients (54.5%). The median survival time of this cohort was 15.2 months (95% confidence interval [CI], 9.9–20.5 months); the estimated one‐ and two‐year survival rates were 68.6% and 31.1%, respectively. The Karnofsky performance score increased significantly after the procedure (p = 0.007). Pneumothorax with pulmonary compression of 30% to 40% occurred in five (15.2%) patients and was cured after drainage. No severe complications occurred. Conclusions CT‐guided iodine‐125 brachytherapy provided a safe and effective choice for recurrent mediastinal lymph node metastasis with significant local therapeutic effects and minor complications, especially for patients who were not eligible for surgical resection and had failed to benefit from systemic therapy.

Objectives: To explore the clinical efficacy and survival of CT-guided Iodine-125 radioactive seed implantation in the treatment of stage Ⅳ primary hepatocellular carcinoma. Methods: A retrospective study of 62 patients with primary hepatocellular carcinoma in our hospital from January 2017 to December 2018 [60 males, 2 females, age (52.76 ​± ​10.82) years old], All patients were implanted with Iodine-125 radioactive seeds under CT guidance, followed up regularly after operation to observe the clinical efficacy, including comparison of changes in cancer size before and after treatment, tumor marker AFP, and improvement in complications such as abdominal pain and ascites. Follow-up 3–36 months to assess patient survival. Results: Among the 62 patients, 3 months after Iodine-125 radioactive seed implantation, 5 cases (8.1%) had complete remission of cancer, 33 cases (53.2%) had partial remission, 12 cases (19.4%) had stable lesions, and 12 cases (19.4%) had disease progression. The effective rate was 61.3%. The tumor volume (31.44 ​± ​14.51cm3) was significantly smaller than before (50.96 ​± ​30.13cm3) (t ​= ​5.303, p ​

Several fluorine-18-labeled PET β-amyloid (Aβ) plaque radiotracers for Alzheimer's disease (AD) are in clinical use. However, no radioiodinated imaging agent for Aβ plaques has been successfully moved forward for either single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. Radioiodinated pyridyl benzofuran derivatives for the SPECT imaging of Aβ plaques using iodine-123 and iodine-125 are being pursued. In this study, we assess the iodine-124 radioiodinated pyridyl benzofuran derivative 5-(5-[124I]iodobenzofuran-2-yl)-N,N-dimethylpyridin-2-amine ([124I]IBETA) (Ki = 2.36 nM) for utilization in PET imaging for Aβ plaques. We report our findings on the radioiododestannylation reaction used to prepare [124/125I]IBETA and evaluate its binding to Aβ plaques in a 5 × FAD mouse model and postmortem human AD brain. Both [125I]IBETA and [124I]IBETA are produced in >25% radiochemical yield and >85% radiochemical purity. The in vitro binding of [125I]IBETA and [124I]IBETA in transgenic 5 × FAD mouse model for Aβ plaques was high in the frontal cortex, anterior cingulate, thalamus, and hippocampus, which are regions of high Aβ accumulation, with very little binding in the cerebellum (ratio of brain regions to cerebellum was >5). The in vitro binding of [125I]IBETA and [124I]IBETA in postmortem human AD brains was higher in gray matter containing Aβ plaques compared to white matter (ratio of gray to white matter was >5). Anti-Aβ immunostaining strongly correlated with [124/125I]IBETA regional binding in both the 5 × FAD mouse and postmortem AD human brains. The binding of [124/125I]IBETA in 5 × FAD mouse and postmortem human AD brains was displaced by the known Aβ plaque imaging agent, Flotaza. Preliminary PET/CT studies of [124I]IBETA in the 5 × FAD mouse model suggested [124I]IBETA was relatively stable in vivo with a greater localization of [124I]IBETA in the brain regions with a high concentration of Aβ plaques. Some deiodination was observed at later time points. Therefore, [124I]IBETA may potentially be a useful PET radioligand for Aβ plaques in brain studies. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy and safety of computed tomography-guided radioactive iodine-125 (125I) seed implantation for oligo-recurrence soft tissue sarcomas following surgical resection. Materials and Methods: Patients with oligo-recurrence soft tissue sarcomas after curative surgical resection between June 2013 and December 2020 were included. The primary outcome measure was objective response rate according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1). The secondary outcomes included progression-free survival, overall survival, and safety profiles. Results: Twenty-nine patients receiving computed tomography-guided 125I seed implantation were included in the study. The objective response rates at 2-, 6- and 12-month follow-up were 48.3%, 65.5% and 40.9%, respectively. The median progression-free survival was 11.3 months. The median overall survival was 25.1 months, with a 1- and 2-year overall survival rate of 81.5% and 50.0%, respectively. No severe treatment-related adverse effects occured. Conclusion: 125I seed implantation has the potential to be an effective and safe treatment for oligo-recurrence soft tissue sarcomas after surgical resection. [ABSTRACT FROM AUTHOR]

The current study is an attempt to confirm the possibility of using rafoxanide (Raf) for diagnostic or radiotherapeutic purpose based on the radioiodine used in the labeling process. The isotopic exchange reaction was performed to radiolabel Raf. The maximum radiochemical yield of [125I]Raf (90%) was obtained when 20 μL of Na[125I]I (7.4 MBq (200 μCi)) in the reaction flask was added to 100 μg of Raf (0.799 mM) within 20 min at 140 °C. High pressure liquid chromatography was used to purify the labeled product of [125I]Raf. The activation energy was calculated experimentally in both ethyl acetate and methanol as reaction medium and found to be 22.82 kJ/mol and 24.43 kJ/mol, respectively. Furthermore, Gaussian 09 used the density function theory (DFT) to calculate the activation energy of the reaction in the two solvents. [ABSTRACT FROM AUTHOR]