125I Seeds Research Articles

Intra-luminal iodine-125 brachytherapy in patients with esophageal carcinoma and 3/4 dysphagia score: A feasibility study.

To evaluate the clinical results of nasal feeding nutritional tube (NFNT)-loaded iodine-125 (125I) seeds in intra-luminal brachytherapy (ILBT) for esophageal carcinoma (EC) patients with a 3/4 dysphagia score. From January 2019 to January 2020, 26 patients (female/male: 17/9, mean age: 75.3 years, dysphagia score 3/4: 6/20, mean Karnofsky score: 58.4) with EC underwent NFNT-loaded 125I seed placement for both nutrition and brachytherapy. Technical and clinical success, D90 (radiation dose received by 90% of tumor volume) and organ at risk (OAR) dose, complications, dysphagia-free time (DFT), and overall survival (OS) time were documented. Local tumor diameter, Karnofsky score, dysphagia score, and quality of life (QoL) were compared before and 6 weeks after tube placement. Technical and clinical success rates were 100% and 76.9%, respectively. The D90 and OAR doses were 39.7 Gy and 2.3 Gy, respectively. Eight cases (30.8%) experienced mild complications, but no seed loss, fistula, and massive bleeding were observed. Median DFT and OS were 3.1 months and 13.7 months, respectively. Tumor diameter and dysphagia score significantly decreased (p < 0.05), Karnofsky score significantly improved (p < 0.05), and QoL scores related to physical function, physical functioning, general health, vitality, and emotional functioning improved (p < 0.05). NFNT-loaded 125I brachytherapy for ILBT is technically a safe and effective strategy for EC patients with low Karnofsky scores, and can be a bridging therapy for advanced anti-cancer treatment.

Three-dimensional template combined with MR-guided iodine-125 brachytherapy for recurrent brain metastases.

Treatment of recurrent brain metastases is extremely challenging. Here, we evaluated the feasibility and efficacy of an individualized three-dimensional template combined with MR-guided iodine-125 (125I) brachytherapy in the treatment of recurrent brain metastases. Twenty-eight patients with recurrent 38 brain metastases underwent 125I brachytherapy from December, 2017 to January, 2021. A pre-treatment brachytherapy plan and three-dimensional template were generated according to isovoxel T1-weighted MR images. 125I seeds were implanted under the guidance of three-dimensional template and 1.0-T open MR imaging. Dosimetry verification was performed based on CT/MR fusion images. Pre-operative and post-operative dosimetry parameters of D90, V100, and conformity index (CI) were compared. Overall response rate (ORR), disease control rate (DCR) at 6 months, and 1-year survival rate were calculated. Median overall survival (OS) measured from the date of 125I brachytherapy was estimated using Kaplan-Meier method. No significant differences were observed between pre-operative and post-operative D90, V100, and CI values (p > 0.05). The ORR and DCR at 6 months were 91.3% and 95.7%, respectively. The 1-year survival rate was 57.1%. The median OS was 14.1 months. Two cases of minor hemorrhage and 5 cases of symptomatic brain edema were observed during the study. All clinical symptoms were alleviated after corticosteroid treatment applied for 7 to 14 days. A three-dimensional template combined with MR-guided 125I brachytherapy in the treatment of recurrent brain metastases is feasible, safe, and effective. This novel 125I brachytherapy strategy is an attractive alternative in the treatment of brain metastases.

Retracted: Analysis on the Efficacy of Bronchial Artery Chemoembolization Combined with 125I Seed Implantation in the Therapy of Advanced Non‐Small‐Cell Lung Cancer Based on the Medical Database

Retracted: Analysis on the Efficacy of Bronchial Artery Chemoembolization Combined with 125I Seed Implantation in the Therapy of Advanced Non‐Small‐Cell Lung Cancer Based on the Medical Database

CT-guided Radioactive 125I Seed Implantation for Abdominal Incision Metastases of Colorectal Cancer: Safety and Efficacy in 17 Patients

IntroductionTo retrospectively evaluate the safety and efficacy of computed tomography (CT)-guided iodine-125 (125I) seed implantation for patients with abdominal incision metastases from colorectal cancer. Materials and MethodsData of patients with abdominal incision metastases of colorectal cancer from November 2010 to October 2020 were retrospectively reviewed. Each incisional metastasis was percutaneously treated with 125I seed implantation under CT guidance. Follow-up contrast-enhanced CT was reviewed, and the outcomes were evaluated in terms of objective response rate, complications, and overall survival. ResultsA total of 17 patients were enrolled in this study. The median follow-up was 18 months (range, 2.7-22.1 months). At 3, 6, 12, and 18 months after the treatment, objective response rate was 52.9%, 63.6%, 33.3%, and 0%, respectively. A small amount of local hematoma occurred in two patients and resolved spontaneously without any treatment. Two patients experienced a minor displacement of radioactive seeds with no related symptoms. Severe complications, such as massive bleeding and radiation injury, were not observed. No ≥ grade 3 adverse events were identified. By the end of follow-up, 14 patients died of multiple hematogenous metastases. The one-year overall survival rate was 41.6%, and the median overall survival was 8.6 months. ConclusionCT-guided 125I seed implantation brachytherapy is safe and feasible for patients with abdominal incision metastases from colorectal cancer.

PHSOR07 Presentation Time: 1:00 PM: Feasibility of Using Dual-Activity Seed Loading When Using Eye Physics Eye Plaques and Plaque Simulator Treatment Planning in Eye Plaque Brachytherapy

<h3>Purpose</h3> Uveal melanoma is a tumor of the eye commonly treated with the application of gold plaques loaded with radioactive I-125 seeds. This study evaluates the dosimetric impact of incorporating dual-activity seed loading in Eye Physics eye plaques under two clinical scenarios that may benefit from this dual-activity approach. <h3>Materials and Methods</h3> Plaque Simulator (Eye Physics, LLC, Los Alamitos, CA) was used to retrospectively re-plan 10 clinical cases for two clinical scenarios: 1) shallow (<5.5 mm) tumors with large base dimensions (16 mm - 19 mm) planned with the largest plaque available from Eye Physics (EP2342 in Fig.1), and 2) tumors very near the optic nerve planned with EP2029N notched plaque (Fig. 1). Five clinical plans were selected for each clinical scenario. The clinical plans chosen were prescribed to at least 2 mm deeper depth than the tumor apex in order to achieve target (base + 2 mm margin) coverage of at least 95%. In the replanning, some of seeds in the plaque were replaced with higher activity seeds. For Scenario 1), EP2342 plaques were planned with the outer ring of sources at twice the activity of the inner sources. For Scenario 2), EP2029N plaques were planned with the 6 seeds closest to the notch at twice the activity of the other sources. Seed loading was kept symmetric for ease of loading, QA, and plaque placement. Plans were based on retinal sketches rather than digitized directly from retinal imaging, so the exact dose to critical structures is an estimate, but the direction and approximate magnitude of the dose change can be analyzed. <h3>Results</h3> In all the cases of large shallow tumors for Scenario 1), the dual-activity plan was able to decrease the prescription depth by 0.8 mm to 1.3 mm. Therefore, doses to all critical structures were consistently lower in dual-activity plans: inner sclera -24.6% ± 1.6%, optic disc -6.5% ± 2.5%, fovea -6.0% ± 3.3% (average ± standard deviation). In 3 out of 5 tumors close to the optic nerve for Scenario 2), the dual-activity plan was able to decrease the prescription depth by 0.5 mm to 0.7 mm. In all 5 of these cases, dose to inner sclera was consistently lower in the re-plans by 20.9%±5.6% and dose to the optic disc and fovea were consistently higher by 19.3%±7% and 21.8%±11.4% respectively. <h3>Conclusions</h3> For large shallow tumors, critical structure dosimetrics were constantly improved due to shallower prescription depth by partially loading with higher activity seeds. The largest dose reduction occurs to the inner sclera since it is close to the plaque, but changes in other critical structures were patient-specific depending the location of the tumor in the eye. It may be beneficial to always plan tumors such as these with dual activities. As this is the largest plaque offered by Eye Physics, this planning approach may allow it to be used for larger tumors while still maintaining reasonable dose to critical structures. For tumors near the optic nerve, the results showed that although scleral dose was decreased, dose to optic disc and fovea were increased. As this difference is due to the location of the tumor relative to the optic nerve and the fovea, it may be beneficial to investigate dual activity plans on a case-by-case basis if scleral dose is a concern for that particular patient.

PO51 Presentation Time: 10:00 AM: Permanent I-125 Seeds Prostate Cancer Mono-Brachytherapy: Outcomes in 273 Patients

<h3>Purpose</h3> Report outcomes of patients undergoing I-125 seeds permanent low-dose-rate (LDR) mono-brachytherapy (mBT) in terms of OS, biochemical failure-free survival (BFFS), recurrence-free survival (RFS) and GU-GI toxicities in localized prostate cancer (LPC). <h3>Materials and Methods</h3> Between 2001 and 2015, 273 patients, undergoing I-125 LDR mBT with no prior curable treatment, with a prostate volume (pV) ≤50cc, cT1 à cT2c (NCCN classification) et iPSA ≤ 20 ng/ml were included and examined. <h3>Results</h3> With a median followup of 68 months, a biochemical failure occurred in 8 patients (4%) patients. The 5 and 8y-BFFS, defined by the Phoenix criterion, were 98.2% and 88.9%, worse for intermediate risk (IR) as compared with low risk (LR), with a 8y-BFFS of 85.7% and 91.5% respectively (p-value=0.01). The 8y-RFS were 96% and 90% for LR and IR respectively. The only factor statistically significant on OS was the age ≤ 65y with a 5 and 8y-OS of 93%/83% vs 89%/73% for ≤ 65y or >65y patients (p-value: 0.031). Surprisingly, we found in a sub-group analysis that 8y-OS for Gleason score 7 disease (GS 4+3 or 3+4) was higher than ≤ Gleason score 6 (83% vs 62%). No difference in outcomes between IR vs LR and ≤ 65y vs >65y patients was observed in terms of 8y-distant metastasis-free survival (DMFS) and prostate cancer specific survival (pCSS). The toxicity profiles suggested, from a follow-up of at least 2 years, that ≥ G3 urinary, GI and sexual toxicities were 5.5%,0.7%, 0% respectively. <h3>Conclusion</h3> I-125 permanent seeds LDR mBT provided excellent outcomes in this study. 8y-local recurrence was 6.5%. Therefore, LDR brachytherapy can be considered and still proposed as an effective treatment option for IR and LR LPC patients.

Detection accuracy of I-125 seeds and needle tips, in MRI prostate tissue mimicking material: Phantom design, fabrication, and testing

• Novel phantom design provides a method of verifying geometric brachytherapy seed and needle tip positions in MRI. • Tests clinically relevant arrangements for seed placements in T1 MRI sequences within prostate tissue mimicking material. • Tests performed with Nitinol needles. • Demonstrates challenges meeting the required accuracy of seed and needle tip detection for brachytherapy in MRI. • Identifies seed placements to be avoided to improve overall accuracy in seed localisation. Accurately identifying needle tip and seed positions for low dose rate prostate brachytherapy on MRI images is challenging. Uncertainties in locating needle tip positions can lead to misplacement of seeds compared to planned coordinates. Furthermore uncertainty in establishing true seed positions on the images, leads to uncertainty in the dose distributions. In this study, a novel phantom has been designed for the analysis of I-125 seed and needle tip detection and tip image distortion. The phantom utilises a gel that mimics prostate tissue in MRI, to evaluate the uncertainty in establishing seed and needle tip positions. Reults are reported for the IsoSeed (Bebig) source, in clinically relevant seed arrangements, and for a novel nitinol needle. The choice of MRI sequence impacts the accuracy of detecting the needle tips and seeds. This is most prevelant when the seeds are in clusters, at the boundary of the prostate and at 90˚ to the long axis of the scanner. Detected needle tip position, when the MRI metal artefact correction algorithm was used, was measured consistently inferior to the actual position (mean tip at -2.3 ± 1.5 mm (k = 2), p = 0.03). We have demonstrated the design of a phantom that can be used to quantitatively assess seed and needle tip positions simultaneously, to establish the accuracy of detection, or presence of artefacts on MRI.

Radio-luminescent imaging for rapid, high-resolution eye plaque loading verification.

Eye plaque brachytherapy is currently an optimal therapy for intraocular cancers. Due to the lack of an effective and practical technique to measure the seed radioactivity distribution, current quality assurance (QA) practice according to the American Association of Physicists in Medicine TG129 only stipulates that the plaque assembly be visually inspected. Consequently, uniform seed activity is routinely adopted to avoid possible loading mistakes of differential seed loading. However, modulated dose delivery, which represents a general trend in radiotherapy to provide more personalized treatment for a given tumor and patient, requires differential activities in the loaded seeds. In this study, a fast and low-cost radio-luminescent imaging and dose calculating system to verify the seed activity distribution for differential loading was developed. A proof-of-concept system consisting of a thin scintillator sheet coupled to a camera/lens system was constructed. A seed-loaded plaque can be placed directly on the scintillator surface with the radioactive seeds facing the scintillator. The camera system collects the radioluminescent signal generated by the scintillator on its opposite side. The predicted dose distribution in the scintillator's sensitive layer was calculated using a Monte Carlo simulation with the planned plaque loading pattern of I-125 seeds. Quantitative comparisons of the distribution of relative measured signal intensity and that of the relative predicted dose in the sensitive layer were performed by gamma analysis, similar to intensity-modulated radiation therapy QA. Data analyses showed high gamma (3%/0.3 mm, global, 20% threshold) passing rates for correct seed loadings and low passing rates with distinguished high gamma value area for incorrect loadings, indicating that possible errors may be detected. The measurement and analysis only required a few extra minutes, significantly shorter than the time to assay the extra verification seeds the physicist already must perform as recommended by TG129. Radio-luminescent QA can be used to facilitate and assure the implementation of intensity-modulated, customized plaque loading.

The efficacy and safety of 125I brachytherapy combined with pre-operative transarterial chemoembolization in patients with locally advanced head and neck cancer.

ObjectiveTo evaluate the safety and effectiveness of Iodine-125 ( 125I) brachytherapy combined with pre-operative transarterial chemoembolization in patients with locally advanced head and neck cancer.MethodsIn this study, a total of thirty-seven individuals suffering from locally advanced head and neck cancer were involved. The patients were subjected to transarterial chemoembolization as well as implantation of 125I seeds under the guidance of CT and ultrasonography. Follow-up was conducted for 36 months to study the following parameters: the local control rate, survival rate, and clinical complications.ResultsIn total, thirty-six patients at the end of three months showed an objective response rate of 69.8% and disease control rate of 93.0%, respectively. The 1, 2, and 3-year cumulative overall survival rate was 89.2%, 73.0%, and 45.9%, respectively. The adverse events of the treatment included infection (n=1, Grade III), radiation brachial plexus injury (n=1, Grade III), leukopenia (n=1, Grade III), cerebrovascular embolism (n=1, Grade IV).ConclusionThe combination of 125I brachytherapy and pre-operative transarterial chemoembolization was safe and effective in patients with locally advanced head and neck cancer.

EP08.05-003 Evaluation of Dose Changes in Different Periods after 125I Seed Implantation in Lung Cancer

125I seed brachytherapy has the characteristics of sustainable, low dose rate and low damage to peripheral organs in the treatment of non-small cell lung cancer, and it is a better choice for local treatment of lung cancer patients. According to the location and size of the target volume, the preoperative plan simulates the seed implantation situation that achieves the optimal dose, and the postoperative verification plan evaluates the quality of the seed implantation. The number of seeds, the angle of needle insertion and the distribution of seeds in the monolayer implant surface are all determinants of dose.

A Comprehensive Analysis of Radiosensitization Properties of Metallic Nanoparticles in Brachytherapy of Gastric Adenocarcinoma by I-125 Seed: A Simulation Study by MCNPX and MCNP6 Codes

Purpose: In the current study, we aimed to look into the macroscopic and microscopic dose enhancement effect of metallic nanoparticles in interstitial brachytherapy of gastric adenocarcinoma by Iodine-125 source using a nano-lattice model in MCNPX (2.7) and MCNP6.1 codes. Materials and methods: Based on a nano-lattice simulation model containing a radiation source and a tumor tissue with cellular compartments loaded with 7 mg/g spherical nanoparticles, the microscopic and macroscopic levels of energy deposition by the secondary electrons was estimated. Results: The results show that the values of macroscopic DEF are higher than microscopic DEF values and the macroscopic DEF values decrease by increasing the distance from the surface of brachytherapy source. Accordingly, it could be noted that gold nanoparticles have the highest radiosensitization effect among the other nanoparticles and the related DEF value is close to the resultant DEF values for bismuth nanoparticles. Moreover, the results revealed a remarkable discrepancy between the DEF and secondary electron spectra calculated by MCNPX (2.7) and MCNP6.1 codes, which could be justified by the difference in energy cut-off and electron transport algorithms of two codes. Conclusions: According to the both MCNPX (2.7) and MCNP6.1 outputs, it could be concluded that the presence of metallic nanoparticles in the tumor tissue of gastric adenocarcinoma increases the physical effectiveness of brachytherapy by I-125 source. This study aims to provide recommendations for future preclinical studies. Actually, the results presented herein give a physical view of radiosensitization potential of different metallic nanoparticles and could be considered in design of analytical and experimental radiosensitization studies in tumor regions using various radiotherapy modalities in the presence of heavy nanomaterials.

Measured, calculated, and egs_brachy I-125 dose distributions in a gold plaque for retinoblastoma treatment.

This study measured and calculated dose distributions around a unique gold plaque for whole-eye radiotherapy (to treat retinoblastoma). The applicator consists of a pericorneal ring attached to the four extraocular muscles and four legs, each loaded with I-125 seeds. They are inserted beneath the conjunctiva in-between each pair of muscles and attached anteriorly to the ring. The applicator was designed in such a way that the dose is directed toward the middle of the eye while sparing surrounding tissues. (I) To compare the measured and calculated data obtained by thermoluminescent dosimeters (TLDs) in a solid-water phantom, a Gafchromic film in a solid-water phantom, the treatment planning systems, and Monte Carlo simulations; (II) to use Monte Carlo simulations for the determination of the dose to the organs at risk by taking the gold shielding and the anisotropy into account. The dose around the applicator was measured using TLDs and Gafchromic EBT2 film in eye-shaped solid-water phantoms. Dose calculations were performed with the TheraPlan Plus and BrachyVision planning system and Monte Carlo simulations with egs_brachy code. A computer-aided design drawing of the applicator was created and used to create the input file for the Monte Carlo simulations. Monte Carlo calculated dose to the optic nerve is 64.8% of the central dose in the eye, whereas the planned dose is 93.7%. The Monte Carlo lens dose varies from 72.0% to 86.1%, whereas the planned dose varies from 73.0% to 84.3%. Monte Carlo-calculated dose to the bony orbit is 11.3%, whereas the planned dose is as high as 54.7% compared to the dose in the center region of the eye. The measured and Monte Carlo-simulated dose distributions matched well, whereas planned dose distributions showed discrepancies in some areas of the eye and outside of the eye due to their ignorance of the shielding effects of the plaque.

Prognostic Evaluation of CT Imaging Big Data-Assisted Arterial Chemoembolization Combined with 125I Seed Implantation for Non-Small-Cell Lung Cancer.

Objective To investigate the prognostic impact of computed tomography (CT) imaging big data-assisted arterial chemoembolization combined with iodine 125 (125I) seed implantation on patients with non-small-cell lung cancer (NSCLC). Methods A total of 116 patients with intermediate and advanced NSCLC hospitalized in our hospital from August 2019 to August 2020 were selected and divided into a control group and an experiment group (58 cases in each group) by random number table method for the study. The patients in the experiment group were treated with CT imaging big data-assisted arterial chemoembolization combined with 125I seed implantation, while the patients in the control group were treated with arterial chemoembolization alone, with the use of gemcitabine combined with cisplatin (GP) in chemotherapy. The prognostic impact was determined by analyzing recent efficacy; the incidence of adverse effects; tumor size and CT perfusion parameters including blood volume (BV), blood flow (BF), and permeability surface (PS); frailty state and quality of life; and the levels of serum tumor markers including carcinoembryonic antigen (CEA), glycoconjugate antigen 125 (CA125), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), microRNA- (miRNA-) 137, and miR-379-5p. In addition, frailty status was evaluated using the Fried frailty phenotype (FP) scale, and quality of life was determined according to Karnofsky Performance Status (KPS) score. Kaplan-Meyer (KM) method was used to analyze the survival rate of NSCLC patients after a 12-month follow-up. Results The remission rate in the experiment group (77.59%) was higher than that in the control group (56.90%) (P < 0.05). Tumor size, BV, BF, PS, serum CEA and CA125 levels, and FP value in both groups were dramatically reduced after treatment compared with before treatment, especially in the experiment group after 1 and 3 months of treatment (P < 0.05). Meanwhile, the serum miR-137 and miR-379-5p levels and KPS scores in both groups were higher after treatment than before treatment, especially in the experiment group after 1 and 3 months of treatment (P < 0.05). However, there was no significant difference in the incidence of nausea and vomiting, alopecia, diarrhea, myelosuppression, and hemoptysis of NSCLC patients in both groups after treatment (P > 0.05). Further, the 12-month survival rate of NSCLC patients was higher in the experiment group (84.21%) than in the control group (64.29%) (P < 0.05). Conclusion CT imaging big data-assisted arterial chemoembolization combined with 125I seed implantation for NSCLC can improve recent efficacy and the prognosis of NSCLC patients by inhibiting tumor progression with a certain degree of safety.

Comparing the inter-seed effect for some iodine-125 brachytherapy sources through a Monte Carlo simulation approach

Background and ObjectiveOne of the principal deficits of TG-43(U1) dosimetry protocol is ignoring the attenuation effect of each seed during the multiseed brachytherapy implants. To take into account this shadowing effect, a parameter known as the inter-seed effect (ISE) has been introduced. Current study aims to evaluate and compare the ISE for some I-125 brachytherapy seeds through a Monte Carlo (MC) simulation approach. MethodsFive different models of I-125 seeds including 6711, ProstaSeed, STM 1251, 3500, and IAI-125A were simulated by MCNPX MC Code. Validity of simulated seed models was confirmed through comparing the corresponding dosimetric parameters such as radial dose function and anisotropy function with those reported by relevant literature. Then, the ISE for each seed at different distances was determined in three seeds implant configuration. Additionally, the relevant attenuation factors (AF) were also determined for each brachytherapy source. ResultsThe obtained results demonstrated that minimum inter-seed attenuation belongs to the ProstaSeed. In return, the maximum inter-seed attenuation was found for 3500 brachytherapy seed. The mean attenuation factor for 6711, ProstaSeed, STM 1251, 3500, and IAI-125A seed models was equal to 0.764, 0.829, 0.785, 0.594, and 0.772, respectively. ConclusionsIt can be concluded that the considered I-125 brachytherapy seeds show different inter-seed effects and mean AF values for the same multiseed implant arrangement. This finding can be attributed to discrepancies in internal seed design and configuration.

Analysis on the Efficacy of Bronchial Artery Chemoembolization Combined with 125I Seed Implantation in the Therapy of Advanced Non-Small-Cell Lung Cancer Based on the Medical Database.

Objective To investigate the use and the efficacy of bronchial artery chemoembolization combined with 125I seed implantation in advanced non-small-cell lung cancer (NSCLC) therapy based on the medical database. Methods A total of 102 patients with advanced NSCLC were randomly divided into two groups. The control group was treated with 125I seed implantation, and the observation group was treated with bronchial artery chemoembolization (BACE) combined with 125I seed implantation based on medical database. The clinical efficacy, carcinoembryonic antigen (CEA), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), glycan antigen 125 (CA125), peripheral blood CD3+, CD8+, CD4+/CD8+ T cells, insulin-like growth factor type 1 receptor (IGF-1R), S100 calcium-binding protein A2 (S100A2), long-term efficacy (time to disease progression, six-month survival rate, and one-year survival rate), and safety were then analyzed. Result The disease remission rate in the observation group was 62.75%, which was higher than that in the control group (41.18%). After 1 month and 3 months of treatment, the levels of serum CYFRA21-1, CEA, CA125, and IGF-1R were lower, while serum S100A2 was higher in the observation group than in the control group (P < 0.05). For safety assessment, we found that the incidences of neutropenia, thrombocytopenia, and gastrointestinal reactions had no statistical differences between two groups. The time to disease progression in the observation group was 129.85 d longer than that in the control group, 89.74 d, and the six-month survival rate and 1-year survival rate were higher in the observation group relative to the control group. Conclusion Medical database-based BACE combined with 125I seed implantation in the therapy of advanced NSCLC patients has definite efficacy with certain safety, which can enhance antitumor effect and prolong survival rate in advanced NSCLC patients.

Salvage 125I brachytherapy for liver metastases of colorectal cancer in anatomically challenging locations after failure of systemic chemotherapy—A retrospective study

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.

Deep learning-based quantitative susceptibility mapping (QSM) in the presence of fat using synthetically generated multi-echo phase training data.

To enable a fast and automatic deep learning-based QSM reconstruction of tissues with diverse chemical shifts, relevant to most regions outside the brain. A UNET was trained to reconstruct susceptibility maps using synthetically generated, unwrapped, multi-echo phase data as input. The RMS error with respect to synthetic validation data was computed. The method was tested on two in vivo knee and two pelvis data sets. Comparisons were made to a conventional fat-water separation pipeline by applying a commonly used graph-cut algorithm, both without and with an extended mask for background field removal (FWS-CONV-QSM and FWS-MASK-CONV-QSM, respectively). Several regions of interest were segmented and compared. Furthermore, the approach was tested on a prostate cancer patient receiving low-dose-rate brachytherapy, to detect and localize the seeds by MRI. The RMS error was 0.292ppm with FWS-CONV-QSM and 0.123ppm for the UNET approach. Susceptibility maps were reconstructed much faster (< 10s) and completely automatically (no background masking needed) by the UNET compared with the other applied techniques (5min 51 s and 22 min 44 s for CONV-QSM and FWS-MASK-CONV-QSM, respectively. Background artifacts, fat-water swaps, and hypointense artifacts between I-125 seeds of a patient receiving low-dose brachytherapy in the prostate were largely reduced in the UNET approach. Deep learning-based QSM reconstruction, trained solely with synthetic data, is well-suited to rapidly reconstructing high-quality susceptibility maps in the presence of fat without needing masking for background field removal.

Encuesta del Grupo de Trabajo de Cirugía Radioguiada (GTCRG) de la Sociedad Española de Medicina Nuclear e Imagen Molecular (SEMNIM): localización radioguiada de lesiones no palpables de mama con o sin indicación de biopsia selectiva de ganglio centinela: ROLL, SNOLL y semillas de 125I

ObjectiveTo know the current status of the technique of radioguided localisation of non-palpable breast lesions with or without indication for selective sentinel node biopsy -ROLL, SNOLL and 125I seeds- by conducting a national survey developed by the Working Group on Radioguided Surgery (GTCRG) of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). Material and methodsIn October 2020, the form was sent in digital format to the different nuclear medicine services in Spain. A response time of 2months with an overtime of 15 days was given. The number of ROLL/SNOLL procedures in each centre and the methodology used were obtained, including important technical details. In addition, a specific section on 125I seeds was included. The results were automatically downloaded into an Excel 2007 spreadsheet for subsequent analysis with the same program. ResultsThe survey was answered by 55 centres; 21 use wire-guided localisation while the remaining 34 use different radioguided surgery techniques (RGS) for the localisation of non-palpable breast lesions, with the results itemized into thirteen sections. The commonly used tracer dose is 111 MBq for the ROLL technique and 222 MBq for the SNOLL technique, with a volume of 0.2ml. The most common protocol is the two-day protocol. 26% of centres performing CRG use 125I seeds for both breast lesion and suspicious/pathological node detection, with the time between implantation and removal being about 3 days, with subsequent radiological control in most cases. ConclusionThe survey shows the relevance of radioguided surgery in the management of breast cancer patients at different stages of the disease, with disparity in the implementation of new techniques and tools, which responds to the multiple healthcare realities of Nuclear Medicine services.

Survey of the Radioguided Surgery Working Group (GTCRG-RGSWG) of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM): Radioguided localization of non-palpable breast lesions with or without indication for selective sentinel node biopsy: ROLL, SNOLL and 125I seeds

ObjectiveTo know the current status of the technique of radioguided localisation of non-palpable breast lesions with or without indication for selective sentinel node biopsy -ROLL, SNOLL and 125I seeds- by conducting a national survey developed by the Working Group on Radioguided Surgery (GTCRG) of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). Material and methodsIn October 2020, the form was sent in digital format to the different nuclear medicine services in Spain. A response time of 2 months with an overtime of 15 days was given. The number of ROLL/SNOLL procedures in each centre and the methodology used were obtained, including important technical details. In addition, a specific section on 125I seeds was included. The results were automatically downloaded into an Excel 2007 spreadsheet for subsequent analysis with the same program. ResultsThe survey was answered by 55 centres; 21 use wire-guided localisation while the remaining 34 use different radioguided surgery techniques (RGS) for the localisation of non-palpable breast lesions, with the results itemized into thirteen sections. The commonly used tracer dose is 111 MBq for the ROLL technique and 222 MBq for the SNOLL technique, with a volume of 0.2 ml. The most common protocol is the two-day protocol. 26% of centres performing CRG use 125I seeds for both breast lesion and suspicious/pathological node detection, with the time between implantation and removal being about 3 days, with subsequent radiological control in most cases. ConclusionThe survey shows the relevance of radioguided surgery in the management of breast cancer patients at different stages of the disease, with disparity in the implementation of new techniques and tools, which responds to the multiple healthcare realities of Nuclear Medicine services.

I-125 seeds brachytherapy with transcatheter arterial chemoembolization for subcapsular hepatocellular carcinoma

BackgroundI-125 seeds brachytherapy (ISB) has been used to improve the clinical effectiveness of transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). We aim to appraise the safety and clinical efficacy of combined ISB and TACE for the treatment of subcapsular HCC.Materials and methodsA retrospective investigative study extending from January 2017 to December 2020, involved individuals suffering from subcapsular HCC, who were subjected to TACE treatment with or without ISB in our center. The clinical effectiveness was compared between 2 groups.ResultsSixty-four patients, in total, with subcapsular HCC had to undergo TACE with (n = 32) or without (n = 32) ISB in our center. After CT-guided ISB, only 2 (6.3%) patients experienced a self-limited pneumothorax. Combined treatment resulted in a significantly higher complete response (56.3% vs. 18.8%, P = 0.002) and total response (90.7% vs. 59.4%, P = 0.004) rates than that of TACE alone. In comparison to the TACE alone group, the median progression-free survival was substantially longer in the combined treatment group (11 months vs. 5 months, P = 0.016). Further, 15 and 28 patients in combined and TACE alone groups respectively died within the follow-up. The median OS was comparable between combined and TACE alone groups (22 months vs. 18 months, P = 0.529).ConclusionsCombined TACE and ISB therapy is a safe treatment method for individuals suffering from subcapsular HCC. When compared, combined treatment had significantly enhanced clinical efficacy as a subcapsular HCC therapy, in comparison to TACE alone.