Particle Implantation Research Articles

Synchronous primary gastric diffuse large B-cell lymphoma and multiple lung primary adenocarcinoma with pulmonary cryptococosis: a case report and literature review

BackgroundThe coexistence of non-Hodgkin’s lymphoma of the stomach and multiple primary lung adenocarcinomas with pulmonary cryptococcosis has rarely been reported.Case presentationWe herein present a 75-year-old man who was admitted to our hospital due to hematemesis. Gastroscopy and imaging revealed extensive stomach wall thickening and multiple lung lesions, including nodules and cavernous lesion. The patient was diagnosed with primary diffuse large B-cell lymphoma via gastroscopy and bilateral lung primary adenocarcinoma with cryptococcal infection via percutaneous CT-guided puncture biopsy. He subsequently underwent six cycles of R-CHOP regimen for gastric lymphoma, along with CT-guided radiofrequency ablation for the upper lobe of the right lung primary adenocarcinoma and radioactive particle implantation was performed on the lower lobe of the left lung primary adenocarcinoma, supplemented with antifungal therapy. After a definite diagnosis and systemic treatment, the patient was followed up for twenty-seven months with no tumor recurrence, progression or metastasis.ConclusionTo the best of our knowledge, the complex combination of multiple primary malignancies and pulmonary cryptococcal infection is extremely rare. The diagnosis is been confusing and challenging. CT-guided needle biopsy can help achieve pathological diagnosis, elucidate the type and stage of the tumor, and even change the clinical treatment strategy, which is necessary and beneficial.

Single-event burnout in β-Ga2O3 Schottky barrier diode induced by high-energy proton

Single-Event Burnout (SEB) can cause hard damage to devices, leading to permanent failure. However, previous studies have rarely explored the effects of high-energy proton irradiation-induced SEB in β-Ga2O3 Schottky Barrier Diode (SBD), and the underlying mechanisms remain largely unexplored. Experimental results indicate that the reverse bias voltage during irradiation is a critical factor influencing the failure of β-Ga2O3 SBD. Compared to 300 MeV proton irradiation without bias, the introduction of a 300 V reverse bias voltage results in a significant reduction in forward current density (JF). When the reverse bias voltage reaches 400 V or higher, the 300 MeV proton induces SEB in the device. The SEM image of the damaged region reveals that the irradiated device has “voids” formed due to the melting of the Ga2O3 material. Geant 4 and TCAD simulation results indicate that the burnout phenomenon is caused by the elevated lattice temperature inside the device, which results from the implantation of secondary particles under a high reverse bias voltage. As the reverse bias voltage increases, the maximum lattice temperature of β-Ga2O3 SBD also rises. When the reverse bias voltage is sufficiently high, the local lattice temperature inside the device reaches the melting point of Ga2O3 material, ultimately leading to SEB.

Application of radioactive iodine-125 microparticles in hepatocellular carcinoma with portal vein embolus.

Radioactive iodine-125 (125I) microparticle therapy is a new type of internal radiation therapy that has shown unique advantages in the treatment of malignant tumors, especially hepatocellular carcinoma. Patients with hepatocellular carcinoma frequently experience portal vein embolism, which exacerbates the difficulty and complexity of treatment. 125I particles, used in local radiotherapy, can directly act on tumor tissue and reduce damage to surrounding healthy tissue. Through retrospective analysis, this study discussed the efficacy and safety of radioactive 125I particles in portal vein embolization patients with hepatocellular carcinoma in order to provide more powerful evidence supporting clinical treatment. To investigate the effect of transcatheter arterial chemoembolization combined with portal vein 125I particle implantation in the treatment of primary liver cancer patients with portal vein tumor thrombus and its influence on liver function. The clinical data of 96 patients with primary liver cancer combined with portal vein tumor thrombus admitted to our hospital between January 2020 and December 2023 were retrospectively analyzed. Fifty-two patients received treatment with transcatheter arterial chemoembolization and implantation of 125I particles in the portal vein (combination group), while 44 patients received treatment with transcatheter arterial chemoembolization alone (control group). The therapeutic effects on tumor lesions, primary liver cancer, and portal vein tumor embolisms were compared between the two groups. Changes in relevant laboratory indexes before and after treatment were evaluated. The t test was used to compare the measurement data between the two groups, and the χ 2 test was used to compare the counting data between groups. The tumor lesion response rate in the combination group (59.62% vs 38.64%) and the response rate of patients with primary liver cancer complicated with portal vein tumor thrombus (80.77% vs 59.09%) were significantly greater than those in the control group (χ 2 = 4.196, 5.421; P = 0.041, 0.020). At 8 wk after surgery, the serum alpha-fetoprotein, portal vein main diameter, and platelet of the combined group were significantly lower than those of the control group, and the serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin were significantly greater than those of the control group (t = 3.891, 3.291, 2.330, 3.729, 3.582, 4.126; P < 0.05). The serum aspartate aminotransferase, alanine aminotransferase, and total bilirubin levels of the two groups were significantly greater than those of the same group 8 wk after surgery (P < 0.05), and the peripheral blood platelet, alpha-fetoprotein, and main portal vein diameter were significantly less than those of the same group before surgery (P < 0.05). In patients with primary liver cancer and a thrombus in the portal vein, transcatheter arterial chemoembolization plus portal vein 125I implantation is more effective than transcatheter arterial chemoembolization alone. However, during treatment it is crucial to pay attention to liver function injury caused by transcatheter arterial chemoembolization.

125I seed implantation for lymph node metastasis from radioactive iodine-refractory differentiated thyroid carcinoma: a study on short-term efficacy and dosimetry.

To investigate the feasibility and evaluate the safety and effectiveness of Computed Tomography (CT) guided125I radioactive particle implantation for treating lymph node metastases in radioiodine-refractory differentiated thyroid cancer (RAIR-DTC). To verify the accuracy of the computerized three-dimensional treatment planning system (TPS) in treating lymph node metastasis using125I particle implantation at the dosimetric level. A retrospective analysis was conducted on 42 patients with RAIR-DTC and lymph node metastases who were admitted to the General Hospital of the Northern Theater Command between December 2016 and January 2019. During this analysis, physicians utilized preoperative CT images to design an intraoperative plan using TPS. The dosimetric parameters of the postoperative plan were then compared to the preoperative plan. Additionally, this study examined the changes in tumor size and tumor-related marker Thyroglobulin (Tg) values in patients at 2, 6, and 12 months after the operation. The number of125I radioactive particles implanted in 42 patients was 226, with an average of 14.5 (range 2.0-30.0) particles implanted per lesion. The local remission rates were 97.62% (41/42), 88.10% (37/42), and 85.71% (36/42) at 2, 6, and 12 months postoperatively, respectively. The volume of the lesions was (4.44 ± 1.57) cm3, (4.20 ± 1.70) cm3, and (4.23 ± 1.77) cm3at 2, 6, and 12 months after treatment, respectively, which significantly decreased from the preoperative baseline level of (6.87 ± 1.67) cm3(t-values: 9.466, 9.923, 7.566, all P<0.05). The Tg levels were 15.95 (5.45, 73.93) μg/L, 8.90 (2.20, 39.21) μg/L, and 6.00 (1.93, 14.18) μg/L at 2, 6, and 12 months after treatment, respectively, which were significantly lower than the preoperative baseline levels of 53.50 (20.94, 222.92) μg/L (Z values: -5.258, -5.009, -4.987, all P < 0.001). Postoperatively, Delivered to 90% of the GTV(D90) was slightly lower than the prescribed dose in 95.23% (40/42) of patients, but the difference was not statistically significant [(12,378.8 ± 3,182.0), (12,497.8 ± 1,686.4) cGy; t=0.251, P>0.05], and postoperative dose parameters delivered to 100% of the gross tumor volume (GTV)(D100) (6,881.5 ± 1,381.8) cGy, the volume percentages of GTV receiving 150% of the prescribed dose(V150) (58.5 ± 18.40)%) were lower than the preoperative plan D100 (8,085.8 ± 2,330.0) cGy, V150 (66.5 ± 17.70)%; t-value=8.913 and 3.032, both P<0.05; the remaining indicators were not significantly different from the preoperative plan (the differences in the number of implanted particles, Planning Target Volume(PTV), the volume percentages of GTV receiving 100% of the prescribed dose(V100), Homogeneity Index(HI)were not statistically significant (t/Z = -0.593, -1.604, 1.493, -0.663, all P>0.05). Referring to the TPS preoperative plan, the125I particle implantation therapy for RAIR-DTC lymph node metastasis can achieve the expected dose distribution, ensuring precise short-term local tumor control efficacy.

CT-guided Percutaneous Microwave Ablation Combined with Local Radiotherapy or Chemotherapy of Malignant Pulmonary Tumors.

The study aimed to investigate the clinical efficacy of CT-guided microwave ablation (MWA) combined with 125I seed implantation or bronchial arterial infusion (BAI) chemotherapy in the treatment of malignant pulmonary tumors. A total of 56 patients who underwent MWA, MWA combined with 125I particle implantation, or MWA combined with BAI chemotherapy for advanced lung cancer or metastatic lung cancer from January 2015 to June 2021 in Guangdong Provincial People's Hospital were enrolled. Among them, 21 patients were treated with MWA (MWA), 18 with MWA combined with 125I seed implantation (MWA+125I), and 17 with MWA combined with BAI chemotherapy (MWA+BAI). The short-term outcomes, complications, Eastern Cooperative Oncology Group (ECOG) performance score (Zubrod-ECOG-WHO, ZPS), survival, and factors related to survival were compared between the three groups. The response rate of the MWA group (9.52%) was significantly lower than that of the MWA+125I group (50.00%) and MWA+BAI chemotherapy group (47.06%), and the differences were statistically significant (p < 0.05). The incidence of complications in the MWA, MWA+125I, and MWA+BAI chemotherapy groups was 47.62%, 55.56%, and 52.94%, respectively, with no significant difference (p > 0.05). Three months after the treatment, the ZPS of the MWA+125I and MWA+BAI chemotherapy groups was significantly lower than before treatment and significantly lower than that of the MWA group in the same period; the differences were statistically significant (p < 0.05). The median survival time of the MWA+125I group was 18 (9.983, 26.017) months and that of the MWA+BAI chemotherapy group was 21 (0.465, 41.535) months, both of which were higher than that of the MWA group [11 (6.686, 15.314) months]; the differences were statistically significant (p < 0.05). Cox regression analysis was performed on the factors related to survival and revealed treatment mode as a protective factor [HR = 0.433, 95% CI = (0.191, 0.984), p = 0.046]. Other factors, such as gender, age, and tumor size, did not independently affect survival. CT-guided MWA combined with 125I seed implantation and MWA combined with BAI chemotherapy are safe and effective for the treatment of advanced lung cancer and metastatic lung cancer, and can control tumor progression and prolong survival time.

Iodine-125 seed inhibits proliferation and promotes apoptosis of cholangiocarcinoma cells by inducing the ROS/p53 axis

With advances in radioactive particle implantation in clinical practice, Iodine-125 (125I) seed brachytherapy has emerged as a promising treatment for cholangiocarcinoma (CCA), showing good prognosis; however, the underlying molecular mechanism of the therapeutic effect of 125I seed is unclear. To study the effects of 125I seed on the proliferation and apoptosis of CCA cells. CCA cell lines, RBE and HCCC-9810, were treated with reactive oxygen species (ROS) scavenger acetylcysteine (NAC) or the p53 functional inhibitor, pifithrin-α hydrobromide (PFTα). Cell counting kit-8 (CCK-8) assay, 5-bromo-2-deoxy-uridine (BrdU) staining, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay and flow cytometry assay were performed to test the radiation-sensitivity of 125I seed toward CCA cells at different radiation doses (0.4 mCi and 0.8 mCi). 2,7-dichlorofluorescein diacetate (DCF-DA) assay, real-time quantitative polymerase chain reaction (RT-qPCR), and western blot analysis were performed to assess the effect of 125I seed on the ROS/p53 axis. A dose-dependent inhibitory effect of 125I seeds on the proliferation of CCA cells was observed. The 125I seed promoted apoptosis of CCA cells and induced the activation of the ROS/p53 pathway in a dose-dependent manner. NAC or PFTα treatment effectively reversed the stimulatory effect of 125I seed on the proliferation of CCA cells. NAC or PFTα suppressed apoptosis and p53 protein expression induced by the 125I seed. 125I seed can inhibit cell growth mainly through the apoptotic pathway. The mechanism may involve the activation of p53 and its downstream apoptotic pathway by up-regulating the level of ROS in cells.

Phantom study of a fully automatic radioactive seed placement robot for the treatment of skull base tumours

BackgroundInterstitial brachytherapy is a form of intensive local irradiation that facilitates the effective protection of surrounding structures and the preservation of organ functions, resulting in a favourable therapeutic response. As surgical robots can perform needle placement with a high level of accuracy, our team developed a fully automatic radioactive seed placement robot, and this study aimed to evaluate the accuracy and feasibility of fully automatic radioactive seed placement for the treatment of tumours in the skull base.MethodsA fully automatic radioactive seed placement robot was established, and 4 phantoms of skull base tumours were built for experimental validation. All the phantoms were subjected to computed tomography (CT) scans. Then, the CT data were imported into the Remebot software to design the preoperative seed placement plan. After the phantoms were fixed in place, navigation registration of the Remebot was carried out, and the automatic seed placement device was controlled to complete the needle insertion and particle placement operations. After all of the seeds were implanted in the 4 phantoms, postoperative image scanning was performed, and the results were verified via image fusion.ResultsA total of 120 seeds were implanted in 4 phantoms. The average error of seed placement was (2.51 ± 1.44) mm.ConclusionThis study presents an innovative, fully automated radioactive particle implantation system utilizing the Remebot device, which can successfully complete automated localization, needle insertion, and radioactive particle implantation procedures for skull base tumours. The phantom experiments showed the robotic system to be reliable, stable, efficient and safe. However, further research on the needle-soft tissue interaction and deformation mechanism of needle puncture is still needed.

Design and Control of Ultrasound Image-guided Prostatic Brachytherapy Robot

Background:: With the continuous development of medical robots, they have become a powerful tool for surgery and treatment. A prostate brachytherapy robot is a kind of robot widely used in prostate cancer treatment; its main function is to accurately implant radioactive seeds into prostate tissue to kill cancer cells. Using prostate brachytherapy robots for surgery can reduce damage to surrounding tissue during surgery, thereby reducing the risk of external electrolysis and metastasis of tumor cells. Objective:: This study aimed to design a prostate brachytherapy robot that is more in line with practical usage needs, based on the method of manually performing prostate brachytherapy surgery in clinical practice. Finally, its feasibility has been demonstrated through brachytherapy experiments. Methods:: Firstly, the actual requirements for prostate particle implantation surgery have been analyzed, which has been followed by reviewing previous literature and patents to determine the design scheme of the robot. Finally, SOLIDWORKS software has been used for mechanical design of the robot, and the control system of the robot has been designed based on Arduino. Results:: A robotic arm type prostate particle implantation robot has been successfully designed. We have installed a visual module on the prostate particle implantation robot, which has enabled the robot system to have image transmission monitoring function to assist in the calibration of the puncture position before surgery. Finally, we have employed other sensors to complete the particle implantation experiment, and successfully confirmed its superiority through comparing errors. Conclusion:: This work has analyzed and studied the clinical process of prostate particle implantation surgery, and designed a prostate particle implantation robot, including the mechanical design and control system design of the robot. We have also simulated the scene of prostate particle implantation surgery in the human body through particle implantation experiments, and successfully and accurately implanted radioactive particles to the target. The experimental results have proven the feasibility of the robot. We have made improvements in execution efficiency by using a parallelogram-based robotic arm as the representation of the prostate particle implantation robot and equipped it with a visual module. The visual module collects a video stream of the puncture needle's perspective and provides feedback to the control end to assist in the calibration of the puncture position before surgery, greatly reducing the probability of secondary injury to patients.

Retrospective study of 70 cases with the head and neck non-parameningeal rhabdomyosarcoma

Objective: To analyze the treatment outcomes and prognoses of children with head and neck non-parameningeal rhabdomyosarcoma (HNnPM RMS). Methods: A retrospective analysis was performed on the clinical data of children with HNnPM RMS admitted to Beijing Children's Hospital from September 2012 to September 2022. The clinical features, comprehensive treatment modes and prognoses of the patients were analyzed. The overall survival rate (OS) and event free survival rate (EFS) were calculated using the Kaplan-Meier method, and univariate analysis was performed using the Log-rank test. Results: A total of 70 children were included in this study, 38 males and 32 females, with a median age of 47 months (2-210 months). Pathological subtypes including the embryonal in 27 cases, the alveolar in 36 cases and the spindle cell and sclerosing in 7 cases. Thirty children (83.3%) with alveolar type were positive for FOXO1 gene fusion. All 70 children underwent chemotherapy, including 38 with neoadjuvant chemotherapy and 32 with adjuvant chemotherapy. Sixty of 70 children underwent surgery, of whom, 10 underwent two or more surgeries. There were 63 children underwent radiotherapy, including 54 with intensity-modulated radiation therapy, 4 with particle implantation and 5 with proton therapy. The median follow-up was 45 (5-113) months, the 5-year OS was 73.2%, and the 5-year EFS was 57.7%. Univariate analysis showed lymph node metastasis (χ2=5.022, P=0.025), distant metastasis (χ2=8.258, P=0.004), and high Intergroup Rhabdomyosarcoma Study (IRS) group (χ2=9.859, P=0.029) as risk factors for poor prognosis. Before June 2016, the 5-year OS based on BCH-RMS-2006 scheme was 63.6%, and after 2016, the 5-year OS based on CCCG-RMS-2016 scheme was 79.6%. Conclusion: Multidisciplinary combined standardized treatment can offer good treatment outcome and prognosis for children with HNnPM RMS. Local control is a key to the efficacy of comprehensive treatment.

Clinical efficacy of iodine-125 radioactive particle implantation with deep hyperthermia in malignant tumor treatment: A retrospective analysis

Clinical efficacy of iodine-125 radioactive particle implantation with deep hyperthermia in malignant tumor treatment: A retrospective analysis

PO110: Prognostic Value of Neutrophil-Lymphocyte Ratio in Patients with Advanced Lung Cancer After Particle Implantation

PO110: Prognostic Value of Neutrophil-Lymphocyte Ratio in Patients with Advanced Lung Cancer After Particle Implantation

Preparation, characterization and biocompatibility of calcium peroxide-loaded polycaprolactone microparticles.

To explore the physicochemical characteristics and biocompatibility of calcium peroxide (CPO)-loaded polycaprolactone (PCL) microparticle. The CPO/PCL particles were prepared. The morphology and elemental distribution of CPO, PCL and CPO/PCL particles were observed with scanning electron microscopy and energy dispersive spectroscopy, respectively. Rat adipose mesenchymal stem cells were isolated and treated with different concentrations (0.10%, 0.25%, 0.50%, 1.00%) of CPO or CPO/PCL particles. The mesenchymal stem cells were cultured in normal media or osteogenic differentiation media under the hypoxia/normoxia conditions, and the amount of released O2 and H2O2 after CPO/PCL treatment were detected. The gene expressions of alkaline phosphatase (ALP), Runt-associated transcription factor 2 (RUNX2), osteopontin (OPN) and osteocalcin (OCN) were detected by realtime RT-PCR. SD rats were subcutaneously injected with 1.00% CPO/PCL particles and the pathological changes and infiltration of immune cells were observed with HE staining and immunohistochemistry at day 7 and day 14 after injection. Scanning electron microscope showed that CPO particles had a polygonal structure, PCL particles were in a small spherical plastic particle state, and CPO/PCL particles had a block-like crystal structure. Energy dispersive spectroscopy revealed that PCL particles showed no calcium mapping, while CPO/PCL particles showed obvious and uniform calcium mapping. The concentrations of O2 and H2O2 released by CPO/PCL particles were lower than those of CPO group, and the oxygen release time was longer. The expressions of Alp, Runx2, Ocn and Opn increased with the higher content of CPO/PCL particles under hypoxia in osteogenic differentiation culture and normal culture, and the induction was more obvious under osteogenic differentiation conditions (all P<0.05). HE staining results showed that the muscle tissue fibers around the injection site were scattered and disorderly distributed, with varying sizes and thicknesses at day 7 after particle injection. Significant vascular congestion, widened gaps, mild interstitial congestion, local edema, inflammatory cell infiltration, and large area vacuolization were observed in some tissues of rats. At day 14 after microparticle injection, the muscle tissue around the injection site and the tissue fibers at the microparticle implantation site were arranged neatly, and the gap size was not thickened, the vascular congestion, local inflammatory cell infiltration, and vacuolization were significantly improved compared with those at day 7. The immunohistochemical staining results showed that the expressions of CD3 and CD68 positive cells significantly increased in the surrounding muscle tissue, and were densely distributed in a large area at day 7 after particle injection. At day 14 of microparticle injection, the numbers of CD3 and CD68 positive cells in peripheral muscle tissue and tissue at the site of particle implantation were lower than those at day 7 (all P<0.01). CPO/PCL particles have good oxygen release activity, low damage to tissue, and excellent biocompatibility.

Validation of calculation method for dose distribution around radioactive iodine-125 particles based on AAPM TG43 report

Objective: According to the formula provided by the TG43 report [AAPM TG43 (2004)] proposed by the American Association of Physicists in Medicine (AAPM) in 2004, we calculated the dose distribution around the radioactive iodine-125 particles, and verified the calculation accuracy of the radioactive iodine-125 particles treatment planning system. Methods: AAPM TG43 (2004) report provides two calculation methods when calculating the dose around a single radioactive source. The calculation method that does not consider the geometric structure of the radioactive source is called point source calculation method, and the calculation method that considers the geometric structure of the radioactive source is called line source calculation method. Assuming a single Amersham 6711 radioactive iodine-125 particle with an activity of 100 U, the following point doses were calculated according to the two calculation methods provided by AAPM TG43 (2004) report, at 0°, 90° directions, distances 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6 cm; In the direction of 45°, the doses at 0.71, 1.41, 2.12, 2.83, 3.54, 4.24, 4.95, 5.66, 6.36, 7.07, 7.78 and 8.49 cm. On the clinically used brachytherapy planning system variseeds 8.0, the above two calculation methods are used to calculate the corresponding activity and the dose around the corresponding type of radioactive iodine-125 particles, and the function of capturing points to templates built in the planning system is used to accurately find the above corresponding point position, using a single measurement of the above corresponding point dose; and comparation of the results were performed to see if there is a statistical difference. Results: The AAPM TG43 report uses point source calculation method to calculate the dose of single Amersham 6711 radioactive iodine-125 particles with activity of 100 U at 0° and 90° directions. The points with the same distance and the same dose are 8 082.18, 1 870.08, 756.58, 381.47, 217.11, 131.91, 86.55, 58.32, 39.97, 27.42, 19.74, 14.13 Gy, respectively, at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6 cm away from them. In the 45° direction, the doses at the distances of 0.71, 1.41, 2.12, 2.83, 3.54, 4.24, 4.95, 5.66, 6.36, 7.07, 7.78 and 8.49 cm are 3 957.37, 865.83, 329.99, 155.69, 84.10, 48.50, 28.49, 17.80, 11.37, 7.38, 4.98 and 3.39 Gy, respectively; For line source calculation method, radioactive particles are at the same distance as above. The doses at each point in the direction of 0° are 3 128.71, 755.44, 330.30, 180.53, 107.74, 68.56, 46.40, 32.22, 22.70, 16.00, 11.51, 8.24 Gy, respectively. The doses at each point in the direction of 90° are 8 306.46, 1 981.01, 802.74, 405.38, 230.60, 140.03, 91.83, 61.84, 42.36, 29.05, 20.91, 14.97 Gy; In the 45° direction, the dose at the corresponding distance as above is 4 020.78, 877.43, 333.49, 156.93, 84.69, 48.81, 28.65, 17.89, 11.42, 7.41, 4.99 and 3.40 Gy, respectively. The maximum dose difference (0.3%) between the two methods is 7.78 cm in the 45° direction, the maximum difference (-0.3%) between the two methods is 8.49 cm in the 45° direction, and the value of other sampling points is less than 0.3%. The closer the Amersham 6711 iodine-125 particles are to the source in the directions of 0°, 45°, and 90°, the faster the dose will drop, and the dose will drop gradually as the distance increases. Conclusion: The brachytherapy planning system variseeds 8.0 and the AAPM TG43 report calculate a maximum dose difference of 0.3%, which can accurately calculate the dose distribution around radioactive iodine-125 seeds, and provide a reliable tool for the clinical implementation of radioactive iodine-125 particles implantation for tumor treatment.

Increased UHMWPE Particle-Induced Osteolysis in Fetuin-A-Deficient Mice.

Particle-induced osteolysis is a major cause of aseptic prosthetic loosening. Implant wear particles stimulate tissue macrophages inducing an aseptic inflammatory reaction, which ultimately results in bone loss. Fetuin-A is a key regulator of calcified matrix metabolism and an acute phase protein. We studied the influence of fetuin-A on particle-induced osteolysis in an established mouse model using fetuin-A-deficient mice. Ten fetuin-A-deficient (Ahsg−/−) mice and ten wild-type animals (Ahsg+/+) were assigned to test group receiving ultra-high molecular weight polyethylene (UHMWPE) particle implantation or to control group (sham surgery). After 14 days, bone metabolism parameters RANKL, osteoprotegerin (OPG), osteocalcin (OC), alkaline phosphatase (ALP), calcium, phosphate, and desoxypyridinoline (DPD) were examined. Bone volume was determined by microcomputed tomography (μCT); osteolytic regions and osteoclasts were histomorphometrically analyzed. After particle treatment, bone resorption was significantly increased in Ahsg−/− mice compared with corresponding Ahsg+/+ wild-type mice (p = 0.007). Eroded surface areas in Ahsg−/− mice were significantly increased (p = 0.002) compared with Ahsg+/+ mice, as well as the number of osteoclasts compared with control (p = 0.039). Fetuin-A deficiency revealed increased OPG (p = 0.002), and decreased levels of DPD (p = 0.038), OC (p = 0.036), ALP (p < 0.001), and Ca (p = 0.001) compared with wild-type animals. Under osteolytic conditions in Ahsg−/− mice, OPG was increased (p = 0.013), ALP (p = 0.015) and DPD (p = 0.012) were decreased compared with the Ahsg+/+ group. Osteolytic conditions lead to greater bone loss in fetuin-A-deficient mice compared with wild-type mice. Reduced fetuin-A serum levels may be a risk factor for particle-induced osteolysis while the protective effect of fetuin-A might be a future pathway for prophylaxis and treatment.

Copper incorporation by low-energy ion implantation in PEO-coated additively manufactured Ti6Al4V ELI: Surface microstructure, cytotoxicity and antibacterial behavior

The purpose of this study is to investigate, for the first time, the biocompatibility and antibacterial behavior of coatings obtained by plasma electrolytic oxidation (PEO) on the Ti6Al4V ELI alloy manufactured through the direct metal laser sintering (DMLS) additive manufacturing technique, implanted with two different concentrations of Cu ions by ion plating diversified (IPD). The surface morphology, elemental composition, and phase characteristics of the PEO coatings were investigated by SEM/EDS, GDOES, XRD, and XPS. The cytotoxicity in stem cells and the antibacterial effect were evaluated. The XPS analysis confirmed the successful incorporation of Cu at both concentrations, which appeared in the form of two different chemical components: CuO (92%) and Cu2O (8%). Stem cells were able to adhere and spread on the surface of the Ti6Al4V ELI alloy, with or without PEO coatings and ionic implantation of Cu particles; the materials and coatings were not cytotoxic. Quantitative cell viability assays for Staphylococcus aureus and Pseudomonas aeruginosa bacteria did not show significant differences. However, the staining of the viability wells, mainly for S. aureus, indicates a change in the behavior of these bacteria in coatings that contained the implantation of Cu oxides. This research demonstrated the potential that the union of the properties of the substrate manufactured in additive manufacturing (great versatility), PEO coatings (wear resistance and cell viability), and IPD ion implanted Cu particles can have in different applications.

Clinical efficacy analysis of radioactive 125I particle implantation for the treatment of pelvic local recurrence of cervical cancer after radiotherapy.

To explore the efficacy of CT-guided iodine-125 (125I) radioactive particle implantation for the treatment of pelvic local recurrence of cervical cancer after radiotherapy. To analyze clinical data of 46 patients with pelvic local recurrence of cervical cancer after radiotherapy, who underwent 125I particle implantation, post-operative follow-up using Kaplan-Meier method to calculate the rate of local control, and observation of complications. Univariate and multi-factorial analyses were performed with log-rank test and Cox regression statistical method to observe changes in serum SCC-Ag and CEA levels. A total of 57 lesions in 46 patients had a short-term local control rate of 87.72% (50/57) and effective rate of 68.42% (39/57). As of the end of follow-up, the median local progression-free survival time of 46 patients was 12.2 (range, 3.5-32) months, the median overall survival time was 16.3 (range, 3.5-40) months, with 1-year and 2-year OS of 63.04% and 41.30%. Univariate and multi-factorial analyses suggested that local recurrent mass size and recurrence site were the main factors affecting survival. Loco-regional progression-free survival (LPFS) time was 15.5 and 11.25 months in cases with recurrent mass diameter < 3 cm and ≥ 3 cm, respectively (χ2 = 10.83, p = 0.001 < 0.05). In patients with pelvic wall recurrence and central recurrence, the time to LPFS was 15.80 and 10.00 months, respectively (χ2 = 8.833, p = 0.0030 < 0.05). Tumor markers serum SCC-Ag and CEA decreased to different degrees after treatment, and the difference was statistically significant. The median LPFS in the SCC-Ag ≤ 3.5 ng/ml group was significantly higher than that in the SCC-Ag > 3.5 ng/ml group (χ2 = 4.241, p = 0.036 < 0.05). No serious post-operative complications were observed. CT-guided 125I seed implantation has significant short-term efficacy in the treatment of pelvic local recurrence of cervical cancer after radiotherapy. It can improve the effective rate in patients with initial clinical stage II, especially in those with locally recurrent masses < 3 cm and in those with a recurrence in the pelvic wall.

Longitudinal in vivo biodistribution of nano and micro sized hydroxyapatite particles implanted in a bone defect.

Hydroxyapatite (HA) has been widely used as a bone substitute and more recently as a carrier for local delivery of bone targeted drugs. Majority of the approved HA based biomaterials and drug carriers comprise of micrometer sized particulate HA (mHA) or granules and can therefore only be used for extracellular drug release. This shortcoming could be overcome with the use of cell penetrating HA nanoparticles (nHA) but a major concern with the clinical use of nHA is the lack of data on its in vivo biodistribution after implantation. In this study, we aimed to study the in vivo biodistribution of locally implanted nHA in a clinically relevant tibial void in rats and compare it with mHA or a combination of mHA and nHA. To enable in vivo tracking, HA particles were first labelled with 14C-zoledronic acid (14C-ZA), known to have a high binding affinity to HA. The labelled particles were then implanted in the animals and the radioactivity in the proximal tibia and vital organs was detected at various time points (Day 1, 7 and 28) post-implantation using scintillation counting. The local distribution of the particles in the bone was studied with micro-CT. We found that majority (>99.9%) of the implanted HA particles, irrespective of the size, stayed locally at the implantation site even after 28days and the findings were confirmed using micro-CT. Less than 0.1% radioactivity was observed in the kidney and the spleen at later time points of day 7 and 28. No pathological changes in any of the vital organs could be observed histologically. This is the first longitudinal in vivo HA biodistribution study showing that the local implantation of nHA particles in bone is safe and that nHA could potentially be used for localized drug delivery.

Immunotherapy with radiotherapy fails to improve prognosis of patients with stage IV non-small cell lung cancer: a retrospective cohort analysis of the THUNDER-2 study

Radiotherapy (RT) may enhance the systemic antitumor reaction to immunotherapy (IT). Currently, the effect of RT in stage IV non-small cell lung cancer (NSCLC) patients treated with IT is uncertain. This study aimed to confirm the role of RT in these patients. We enrolled 120 stage IV NSCLC patients who had been treated with IT and had received external beam radiation therapy (EBRT) or radioactive particle implantation (RPI) at 3 oncology centers in Shandong province between 2019 and 2021. We assessed relevant clinical factors and regular follow-up was conducted via electronic medical records and telephone. The primary endpoint was overall survival (OS). Different combination models in various populations were compared by generating Kaplan-Meier curves and Cox regression analysis. The OS for the overall population was 5 months (range, 0-31 months) and the overall survival rate was 47.5%. Patients receiving IT with RPI had the least favorable prognostic trend (median survival: 2 months) compared to those receiving IT without RT (median survival: 9 months) and IT with EBRT (median survival: 10 months), but this difference was not significant (P=0.148). In subgroup analysis, patients treated with IT with RPI appeared to have a worse prognosis in some specific cohorts, such as males [hazard ratio (HR) =2.433, P=0.031], non-squamous carcinoma histologies (HR =2.680, P=0.034), patients with oligometastases (HR =7.967, P=0.024), patients with liver metastases (HR =10.808, P=0.011) or brain metastases (HR =20.087, P=0.005), and those with Eastern Cooperative Oncology Group (ECOG) performance score ≥2 (HR =2.769, P=0.043). Multivariate Cox analysis of total population revealed that ECOG score and IT stage were the independent prognostic factors. IT combined with EBRT did not have a significant survival benefit in all subgroups. Concurrent IT with RT and first-line and second-line IT combined with RT trended toward improved long-term prognosis. While the robustness of the present conclusions is limited by relatively small sample size and retrospective nature of this research, the addition of EBRT or RPI to IT did not significantly improve patients' OS in stage IV NSCLC. Early combination IT after RT may benefit patients with long-term survival.

Highlighting the Implantation of Metal Particles into Hollow Cavity Yeast-Based Carbon for Improved Electrochemical Performance of Lithium–Sulfur Batteries

The introduction of metal particles into microbe-based carbon materials for application to lithium–sulfur (Li–S) batteries has the three major advantages of pore formation, chemisorption for polysulfides, and catalysis of electrochemical reactions. Metal particles and high specific surface area are often considered to enhance the properties of Li–S batteries. However, there are few data to support the claim that metal particles implanted in microbe-based carbon hosts can improve Li–S battery performance without interfering with the specific surface area. In this work, hollow-cavity cobalt-embedded yeast-based carbon (HC–Co–YC) with low specific surface area was successfully produced by impregnating yeast cells with a solution containing 0.075 M CoCl2 (designated as HC–Co–YC–0.075M). Cobalt particles implanted in yeast carbon (YC) could improve the conductive properties, lithium-ion diffusion, and cycling stability of the sulfur cathode. Compared to previously reported counterpart electrodes without metal particles, the HC–Co–YC–0.075M/S electrode in this study had a high initial specific capacity of 1061.9 mAh g−1 at 0.2 C, maintained a reversible specific capacity of 504.9 mAh g−1 after 500 cycles, and showed a capacity fading rate of 0.1049% per cycle. In conclusion, the combination of cobalt particles and YC with low specific surface area exhibited better cycle stability, emphasizing the importance of implantation of metal particles into carbon hosts for improving the electrochemical properties of Li–S batteries.

Surface microstructures of lunar soil returned by Chang’e-5 mission reveal an intermediate stage in space weathering process

The lunar soils evolution over time is mainly caused by space weathering that includes the impacts of varying-sized meteoroids and charged particles implantation of solar/cosmic winds as well. It has long been established that space weathering leads to the formation of outmost amorphous layers (50–200 nm in thickness) embedded nanophase iron (npFe0) around the mineral fragments, albeit the origin of the npFe0 remains controversial . The Chang’e-5 (CE-5) mission returned samples feature the youngest mare basalt and the highest latitude sampling site , providing an opportunity to seek the critical clues for understanding the evolution of soils under space weathering. Here, we report the surface microstructures of the major minerals including olivine, pyroxene, anorthite, and glassy beads in the lunar soil of CE-5. Unlike the previous observations, only olivine in all crystals is surrounded by a thinner outmost amorphous SiO2 layer (∼10 nm thick) and embedded wüstite nanoparticles FeO (np-FeO, 3–12 nm in size) instead of npFe0. No foreign volatile elements deposition layer and solar flare tracks can be found on the surface or inside the olivine and other minerals. This unique rim structure has not been reported for any other lunar, terrestrial, Martian, or meteorite samples so far. The observation of wüstite FeO and the microstructures support the existence of an intermediate stage in space weathering for lunar minerals by thermal decomposition.