Calculation of organ dose of 90Y TheraSphere in the treatment of pancreatic cancer / 中国辐射卫生

Objective To calculate the absorbed dose of 90Y TheraSphere in the pancreas and the surrounding sensitive organs after the administration in the treatment of pancreatic cancer through the establishment of an individual voxel model, and to provide technical support for the clinical application of 90Y TheraSphere in the treatment of pancreatic cancer. Methods An individualized voxel model was constructed in Geant4 software based on the CT images of the patient. 12 monoenergetic electron specific absorption fractions (SAFs) in the range of 0.01 to 1 MeV were calculated and validated against the ICRP data. The model and method were used to calculate the absorbed doses in the target organs under uniform and nonuniform distribution of 90Y microspheres in the pancreas. Results The relative errors between the SAF values calculated based on the individualized voxel model and the ICRP data after mass calibration were less than 3.89%. When 90Y was uniformly distributed in the pancreas, the absorbed dose in the pancreas was 4.69 × 10−7 Gy/Bq; the absorbed doses in the liver, kidneys, and spleen were 6.15 × 10−12, 6 × 10−12, and 1.65 × 10−11 Gy/Bq, respectively. When 90Y was distributed within the tumor, the absorbed dose in the tumor was 6.69 × 10−6 Gy/Bq and the absorbed dose in normal pancreas was 5.72 × 10−8 Gy/Bq. The fitted relationship between tumor volume V and administered activity A at the prescribed dose of 120 Gy was quadratic, with relatively low activity required for concentrated administration in the center of the tumor. Conclusion The Monte Carlo dose calculation method based on individual voxel model accurately predicted the absorbed doses in the surrounding sensitive organs (liver, kidneys, and spleen) when 90Y TheraSphere was used to treat pancreatic cancer. These results and the analysis of the factors affecting the drug delivery activity will provide data support for the clinical research of 90Y TheraSphere in pancreatic cancer.

Impact of radioactive impurity nuclides in 90Y microspheres on the therapeutic dose of pancreatic tumors / 中国辐射卫生

Objective To evaluate the effects of radioactive impurity nuclides in 90Y glass microsphere on therapeutic dose during radioembolization of pancreatic cancer. To provide a reference for correction of the dose calculated for individuals with different pancreatic tumors. Methods In this study, the radioactive impurity nuclide composition of 90Y glass microsphere samples was analyzed to determine the source term of Monte Carlo calculation. Then, according to the PET/CT medical imaging data of pancreatic cancer patients, the three-dimensional modeling software Solidworks 2020 was used to construct the real and personalized digital human digestive system model of pancreatic cancer patients at a resolution showing the vascular distribution in pancreas and tumor. Finally, the Monte Carlo program GATE 8.2 was used to simulate the three-dimensional radiation dose fields of radioactive impurity nuclides 91Y and 65Zn from 90Y glass microspheres in various tissues and organs. The three-dimensional dose fields were visualized to analyze the influence of radioactive impurity nuclides on therapeutic dose. Results The three-dimensional radiation dose fields of 91Y and 65Zn from 90Y glass microspheres demonstrated two dose extreme points. The maximum dose value of 91Y to tissue was 0.272 mGy and the maximum dose value of 65Zn to tissue was 9.34 μGy, with average statistical errors of less than 3.2%. Conclusion The impact of radioactive impurity nuclides 91Y and 65Zn in 90Y glass microsphere sample on therapeutic dose is minimal and can be neglected.

Measurement and analysis of 90Y radioactivity in urine of patients treated with 90Y resin microspheres / 中华放射医学与防护杂志

Objective:To evaluate 90Y activity concentration in renal excretions during the first 48 hours after being treated with 90Y resin microspheres seleceive internal radiation therapy(SIRI) and to provide advice on the management of patient excreta after surgery. Methods:After surgery, urine excreted from 3 patients during 0-24 h and 24-48 h was collected respectively, and the 90Y activity concentration in urine was tested and analyzed. Results:90Y radioctivity in the urine excreted from 3 patients after surgery was (1 266±258)kBq/GBq during 0-24 h and (140±106) kBq/GBq during 24-48 h, respectively, and 90Y activity concentration were (640±113) kBq/L during 0-24 h and (53±12) kBq/L during 24-48 h. Conclusions:90Y radioactivity in patient′s urine excreted at 1 d was about 10 times higher than that at 2 d. After surgery, patients can accelerate the reduction of free 90Y activity by increasing excretion. Urine excreted by the patients during hospitalization should be handled in accordance with the requirements of the national standard HJ 1188-2021 Radiation protection and safety requirements for nuclear medicine.

Radiological protection detection and dose assessment of selective internal radiotherapy with 90Y resin microspheres / 中华放射医学与防护杂志

Objective:To conduct radiation detection and dose assessment in selective internal radiotherapy with 90Y resin microspheres for the purpose of providing a reference for radiological protection. Methods:The dose rates from radiotherapy with 90Y resin microspheres were detected in the process of each operation at different distances from the body surface of patients the levels of dose to the persons concerned were compared with the relevant national regulations and standards. Results:The estimated dose rates were 1.12-454 μSv/h during 90Y resin microspheres dispensing and 2.06-58.2 μSv/h during surgical procedure. The dose rates at 0.5 h after surgery were 22.7-64.1 μSv/h at 5 cm and 0.82-2.55 μSv/h at 1 m from three patient′s body surface. Assuming treating 200 patients a year, the annual individual effective dose to the radiation workers was 0.12-1.03 mSv/year. The annual individual effective dose to the public, comforters and carers of patients was 0.02-0.24 mSv/year after release of a patient. Conclusions:During the treatment, nursing and release of patients, the radiation doses to workers, carers and the public are lower than the individual dose limit given in the GB18871-2002 basic standards for protection against ionizing radiation and for the safety of radiation sources and the management target value set by of the relevant medical institutions.

Observation on the effect of 90Sr-90Y application combined with corn paste in the treatment of corns / 中国辐射卫生

Objective To evaluate the clinical efficacy and satety of 90Sr-90Y application combined with corn paste in the treatment of corns. Methods 85 patients with corns in the First People's Hospital of Tianmen from September 2019 to December 2020 were selected and randomly divided into group A, group B and group C based on random number table. In group A, 28 cases were treated with simple 90Sr-90Y application; in group B, 27 cases were treated with 90Sr-90Y application plus intermittent corns paste; in group C, 30 cases were treated with 90Sr-90Y application plus continuous corns paste.The treatment effect, recovery time, recurrence rate and incidence of adverse reactions of the three groups were compared. Results The cure rates of the three groups were 78.57% (21/28), 81.48% (22/27) and 83.33% (25/30), with no significant difference (P > 0.05); the total effective rates were 92.86% (26/28), 92.59% (25/27) and 96.67% (29/30), the difference was not significant (P > 0.05); the cure time was (5.67 ± 1.80) weeks, (2.82 ± 1.11) weeks and (2.24 ± 1.05) weeks, the cure time of the B and C groups was significantly shorter than that of the A group (P < 0.05); The incidence of adverse reactions were 9.52% (2/21), 4.55% (1/22) and 4.00% (1/25), respectively, the difference was not significant (P > 0.05); the incidence of adverse reactions were 3.57% (1/28), 11.11% (3/27) and 26.67% (8/30), the incidence of adverse reactions in group C was higher than Group A (P < 0.05). Conclusion The combination of 90Sr-90Y application and intermittent corns paste in the treatment of corns has good curative effect, low recurrence rate, short cure time and few adverse reactions. It is worthy of clinical promotion.

Radioembolization for the treatment of hepatocellular carcinoma

Transarterial radioembolization (TARE) with yttrium 90 (⁹⁰Y), an intra-arterial procedure performed by interventional radiologists, has begun being utilized in managing hepatocellular carcinoma (HCC) in Korea. There are two available TARE products: glass and resin microspheres with different physical characteristics. All patients undergoing TARE must be assessed with clinical examination and laboratory tests as well as a thorough angiographic evaluation. TARE is safe and effective in the treatment of unresectable HCC, as it has longer time-to-progression, greater ability to downsize tumors for liver transplantation, less post-embolization syndrome, and shorter hospitalization compared with chemoembolization. TARE can also serve as an alternative to ablation, surgical resection, portal vein embolization, and sorafenib. The utility of TARE continues to expand with new insights in interventional oncology.

Preparation & in vitro evaluation of 90Y-DOTA-rituximab.

Background & objectives: Radioimmunotherapy is extensively being used for the treatment of non-Hodgkin’s lymphoma (NHL). Use of rituximab, a chimeric anti-CD20 antibody directed against the CD20 antigen in combination with suitable beta emitters is expected to result in good treatment response by its cross-fire and bystander effects. The present work involves the conjugation of p-isothiocyanatobenzyl DOTA (p-SCN-Bn-DOTA) to rituximab, its radiolabelling with 90Y and in vitro and in vivo evaluation to determine its potential as a radioimmunotherapeutic agent. Methods: Rituximab was conjugated with p-SCN-Bn-DOTA at 1:1 antibody: DOTA molar ratio. The number of DOTA molecules linked to one molecule of rituximab was determined by radioassay and spectroscopic assay. Radiolabelling of rituximab with 90Y was carried out and its in vitro stability was evaluated. In vitro cell binding studies were carried out in Raji cells expressing CD20 antigen. Biodistribution studies were carried out in normal Swiss mice. Results: Using both radioassay and spectroscopic method, it was determined that about five molecules of DOTA were linked to rituximab. Radiolabelling of the rituximab conjugate with 90Y and subsequent purification on PD-10 column gave a product with radiochemical purity (RCP) > 98 per cent which was retained at > 90 per cent up to 72 h when stored at 37°C. In vitro cell binding experiments of 90Y-DOTA-rituximab with Raji cells exhibited specific binding of 20.7 ± 0.1 per cent with 90Y-DOTA-rituximab which reduced to 15.5 ± 0.2 per cent when incubated with cold rituximab. The equilibrium constant Kd for 90Y-DOTA-Rituximab was determined to be 3.38 nM. Radiolabelled antibody showed clearance via hepatobiliary and renal routes and activity in tibia was found to be quite low indicating in vivo stability of 90Y-DOTA-rituximab. Interpretation & conclusions: p-SCN-Bn-DOTA was conjugated with rituximab and radiolabelling with 90Y was carried out. In vitro studies carried out in Raji cells showed the specificity of the radiolabelled conjugate suggesting the potential uitability of the formulation as a radiopharmaceutical for therapy of NHL.

Influence of age factor on treating cutaneous hemangioma with 90 Sr-90Y applicator / 中华医学美学美容杂志

Objective To explore the influence of age factor on the treatment of cutaneous hemangioma with (90Sr-90Y) applicator.Methods A total of 224 babies and children of different ages with cutaneous hemangioma were treated by using 90Sr-90 Y applicator.Then,the relation between their therapeutic effects and ages were analyzed respectively.Results The differences in the therapeutic effect between group of one month to less than one year and group of one to less than five years,and group of one month to less than one year and group of five to ten years,and between group of one to less than five ages and group of five to ten years (P＜0.05),were statistically significant.With an increase of the age,the recovery rate gradually decreased,but their effective rate,improvement rate and ineffective rate increased.In the 199 well-healed or effective patients,the differences in the distribution of treatment course between group of one month to less than one year and group of one to less than five years,and group of one month to less than one year and group of five to ten years,were statistically significant (P＜0.05); but the difference in the distribution of treatment course between group of one to less than five ages and group of five to ten years was not statistically significant (P＞0.05).The number of treatment course presented an increased tendency with an increase of the age for patients.Conclusions The age of patients is a factor influencing the therapeutic effect on cutaneous hemangioma with 90 Sr-90Y applicator.The younger the patients,the better their therapeutic effects,the shorter their courses of treatment,and the smaller the adverse reaction of beta ray.

Effect of 90Sr-90Y ophthalmic applicator on corneal neovascularization after alkali burn / 中华实验眼科杂志

Background Corneal neovascularization ( CNV ) is a complication of many ocular surface diseases.It often worsen the pathological course.Effective therapy for CNV is still researching. Objective This study was to investigate the inhibitory effect of irradiation on CNV. Methods CNV models were established in 70 right eyes of 70 clean Wistar rats by corneal alkali burning.The models were randomized into β ray 10 Gy once irradiation group( 2 eyes),β ray 7 Gy multiple irradiation group( 17 eyes),β ray 10 Gy multiple irradiation group( 17 eyes),1％ cyclosporin A ( CsA ) eye drops group ( 17 eyes) and model group ( 17 eyes),and 6 matched normal rats were used as normal controls.All treatments started from the first day of the corneal alkali burning.CNV length and area were measured under the slit lamp every day.Corneal samples and homogenate were prepared 3,5,7 days after corneal alkali burning.The expressions of bcl-2,bax,vascular endothelial growth factor(VEGF) in rat corneas were detected by immunochemistry,VEGF proteins and VEGF mRNA were detected by Western blot and reverse transcription polymerase chain reaction (RT-PCR),respectively. Results Corneal ulceration was found in the βray 10 Gy once irradiation group and β ray 10 Gy multiple irradiation group.CNV length and area were much less in the β ray 7 Gy multiple irradiation group and 1％ CsA eye drops group compared with the model group on the seventh day after experiment( length:q=14.40,24.20,P＜0.01 ;area:q=17.80,14.00,P＜0.01 ).Immunochemistry revealed that compared with the model group,expressions of bcl-2 and VEGF proteins were weaker,but the expression of bax protein was stronger in the β ray 7 Gy multiple irradiation group and 1％ CsA eye drops group.RT-PCR showed that the expression of VEGF mRNA in cornea was lower in the β ray 10 Gy multiple irradiation group,β ray 7 Gy multiple irradiation group and 1％ CsA eye drops group in comparison with that in model group,and the results from Western blot showed the same pattern as RT-PCR. Conclusions Low dose irradiation of 90Sr-90Y ophthalmic applicator inhibits CNV formation after alkali burn.The study provide a new understanding of the irradiation for the treatment of CNV.

Tratamiento de tumores neuroendocrinos (TNE) con péptidos análogos de la somatostatina marcados con radionucleidos / Treatment of neuroendocrine tumors (NET) with radiolabelled somatostatin analogues

Propósito. Los TNE avanzados tienen escasa respuesta a radioterapia o quimioterapia, el tratamiento sistémico con análogos de la SST radiactivos es una herramienta promisoria en su tratamiento. Presentamos nuestra experiencia, pionera en Latinoamérica, utilizando análogos de SST marcados con 90Y ó 177Lu. Material. Evaluamos 40 pacientes (50.3 años, rango 12-74) con TNE confirmados histológicamente y sobre-expresión de receptores de SST demostrada mediante imágenes. SPECT (111In-DOTATOC) ó PET/CT (68Ga-DOTATATE). Se evaluó respuesta clínica, laboratorio, imágenes con 111In-DOTATATE, post-terapia con 90Y ó 177Lu, 68Ga-DOTATATE PET/CT o TAC. Resultados. Observamos progresión de enfermedad en 10 (25.0 por ciento), remisión parcial en 25 (62.5 por ciento), enfermedad estable en 3 (7.5 por ciento) y remisión completa en 2 (5.0 por ciento). Hubo escasa toxicidad sin deterioro renal significativo. Observamos reducción tumoral y mejoría de calidad de vida en la mayoría de los pacientes. Conclusión. La terapia con radiopéptidos es un procedimento seguro y efectivo en el tratamiento de TNE avanzados.

Purpose. Advanced NETs have little response to radiotherapy or chemotherapy, systemic treatment with radioactive SST analogous is a promissory tool in its treatment. We present our pioneering experience in Latin America using analogous of SST labeled either with 90Y or 177Lu. Materials. We evaluated 40 patients (50.3 years, range 12-74) with histological proved NET and SST receptors over-expression demonstrated by SPECT or PET/CT images with 111In-DOTATOC or 68Ga-DOTATATE. We evaluated clinical response, laboratory test, images with 111In-DOTATATE, 90Y, 177Lu, and 68Ga-DOTATATE PET/CT or CT. Results. We observed progression of disease in 10 (7,5 percent), partial remission in 25 (62,5 percent), stable disease in 3 (7,5 percent) and complete remission in 2 (5,0 percent). There was little toxicity without significant renal deterioration. We observed tumor mass reduction and improvement of quality of life in most of the patients. Conclusion. The therapy with radiopeptides is a safe and effective procedure in the treatment of advanced NET.

Experimental study of intratumor injection of ~(90)Y-SAg for the treatment of liver cancer in mice / 医学研究生学报

0.05).The differences of necrosis rates of tumors in all the three groups(0.36?0.18 in group A,0.11?0.09 in group B and 0.10?0.06 in group C) had statistically shown the same results mentioned above. Conclusion: Intratumor injection of ~(90)Y-SAg is a safe,feasible and effective method to treat liver cancer in mice.

Experiment Study of Radioactive Distribution of Intrahepatically Injected ~(90)Y Glass Microsphere / 中华超声影像学杂志

Different doses of ~(90)Y glass microspheres weres injected into the livers of rabbits under ultrasound guidance to observe the distribution of isotope in the body and the histologic alteration in the liver. The result showed that the isotope microspheres were only limited at the injected areas. The areas o.f bremsstrahlung ranged 4.1～12.55cm~2(mean 8.45cm~2). Whole body scanning revealed that the isotope was not observed outside the liver and no injury of non-target organ was present. When the dose was 35 mci, complete necrosis appeared in the hepatic cells within the bremsstrahlung areas. The study indicales that intrahepatic injection of ~(90)Y glass microspheres is accurmuate in locallization, produces high local iradiation energy and may become a non-surgical way for treating carcinoma of liver.