The complication rate following Neodymium-doped Yttrium Aluminum Garnet laser posterior capsulotomy for posterior capsular opacification in patients with and without comorbidities

Purpose: To study the complication rate following Nd: YAG posterior capsulotomy posterior capsular opacification (PCO) in patients with and without comorbid conditions. Methods: This was a prospective, interventional, comparative, and observational study. A total of 80 eyes, consisting of 40 eyes without ocular comorbidities (group A) and 40 eyes with ocular comorbidities (group B) that were being treated with Nd: YAG capsulotomy for PCO, were included. Visual outcome and complications of Nd: YAG capsulotomy were studied. Results: The mean age of group A patients was 61.65 ± 8.85 years and that of group B patients was 63 ± 10.46 years. Of the total, 38 (47.5%) were men and 42 (52.5%) were women. In group B, the ocular comorbidities were moderate nonproliferative diabetic retinopathy (NPDR) (n = 14 eyes; 14/40 = 35%), subluxated intraocular lens (IOL; <2 clock hours of subluxation; n = 6), age?related macular degeneration (ARMD; n = 6), post?uveitic eyes (having old signs of uveitis, no episode of uveitis since the last 1 year; n = 5), and operated cases of traumatic cataract (n = 4). The mean energy required in groups A and B was 46.95 ± 25.92 and 42.62 ± 21.85 mJ, respectively (P = 0.422). The average energy requirement in Grade 2, Grade 3, and Grade 4 PCO was 22.30, 41.62, and 79.52 mJ, respectively. An increase in intraocular pressure (IOP) of >5 mmHg from pre?YAG levels was observed in one patient in each group on day 1 postprocedure, for which medical treatment was given to both patients for 7 days. One patient in each group had IOL pitting. No patient had any other complications attributable to ND:YAG capsulotomy. Conclusion: Nd:YAG laser posterior capsulotomy is a safe procedure for PCO in patients with comorbidities. Visual outcomes were excellent after Nd:YAG posterior capsulotomy. Although a transient increase in IOP was noted, the response to treatment was good and a long?term increase in IOP was not observed

Effect of Neodymium-Doped Yttrium Aluminum Garnet Laser Combined With Desensitizing Toothpaste on Dentinal Tubule Occlusion Against Acid Challenge / 中国医学科学院学报

Objective To assess the effects of different application sequences of neodymium-doped yttrium aluminum garnet(Nd∶YAG)laser and the desensitizing toothpaste containing stannous fluoride on dentinal tubule occlusion.Methods Twelve intact third molars freshly extracted from human were selected and prepared into dentin slices with a thickness of 0.8 mm.Each dentin slice was subdivided into four small slices,three of which were etched with 6% citric acid and randomly assigned to the following three groups(n=12):(1)control group:no treatment;(2)Nd∶YAG+toothbrushing(TB)group:first irradiated with Nd∶YAG laser and then brushed with desensitizing toothpaste;(3)TB+Nd∶YAG group:first brushed with desensitizing toothpaste and then irradiated with Nd∶YAG laser.The Nd∶YAG laser irradiation were carried out at 1 W,15 pulses/s,and the pulse width of 150 μs for 10 s(for a total of 6 cycles).After the above treatment,the 12 dentin slices from the Nd∶YAG+TB and TB+Nd∶YAG groups were randomly assigned to four subgroups(n=3)and subjected to acid etching in the Coca-Cola solution for 0,5,10,and 15 min.A scanning electron microscope was used to observe and photograph the dentin slices in each group,and eight single-blinded examiners scored the slices according to uniform criteria.The analysis of variance was carried out to compared the scores between groups.Results Before acid etching,the dentin tubule occlusion scores of the Nd∶YAG+TB and TB+Nd∶YAG groups were(4.83±0.09) scores and(3.85±0.66) scores,respectively,which had no significant difference between each other(P=0.0590)and were higher than that[(0.10±0.07)scores]of the control group(both P<0.0001).The dentin tubule occlusion scores of the Nd∶YAG+TB group after acid etching for 5,10,and 15 min were(4.33±0.60)scores,(4.27±0.24)scores,and(3.63±0.07)scores,respectively,which were not significantly different from those[(4.04±0.10)scores,(3.76±0.59)scores,and(3.17±0.29)scores,respectively]of the TB+Nd∶YAG group(all P>0.05).In the Nd∶YAG+TB subgroup,the dentin tubule occlusion score after acid etching for 15 min was significantly lower than that before acid etching(P=0.0011).In the TB+Nd∶YAG group,there was no statistically significant difference in the score between before and after acid etching(P>0.05).Conclusions Nd∶YAG laser irradiation with appropriate parameters combined with the use of desensitizing toothpaste could produce an excellent occluding effect on dentinal tubules regardless of the sequence.However,brushing with desensitizing toothpaste followed by Nd∶YAG laser irradiation produced more consistent dentin sealing after acid etching.

Effect of different mechanical surface treatments on flexural strength of repaired denture base / Efecto de diferentes tratamientos superficiales mecánicos sobre la resistencia a la flexión de la base de la dentadura reparada

Aim: To assess the effect of different mechanical surface treatments on flexural strength of repaired denture base. Material and Methods: Sixty bar-shaped specimens of heat-polymerized acrylic resin were fabricated, and divided into six groups (n=10). All specimens, except the positive control group (group PC), were sectioned into halves to create a 1-mm clearance. A negative control group with no surface treatment (group NC) was also considered. Other groups underwent different surface treatments: group Laser; treated with erbium: yttrium-aluminum-garnet (Er:YAG) laser, group APA; airborne-particle abrasion (APA), group APA plus Laser; a combination of laser and APA, and group Bur; bur grinding. After measuring surface roughness (Ra) with a profilometer, all sectioned specimens were repaired by auto-polymerizing acrylic resin, and thermocycled afterward. Three-point bending test was performed by a universal testing machine. Data were statistically analyzed (α=0.05). Results: The mean surface roughness of all experimental groups were significantly higher than that of group NC (p<0.05). The mean flexural strength of all groups was significantly lower than that of group PC (p<0.05). Group B had significantly higher flexural strength than the other surface-treated groups (p<0.05). Group Laser had significantly higher flexural strength than groups APA (p=0.043) and APA plus Laser (p=0.023). No significant difference was found between groups APA and APA plus Laser (p=0.684). Conclusion: All surface treatments increased the surface roughness and flexural strength compared with the untreated group. The highest flexural strength was observed in specimens treated by bur grinding and then laser, however, it was still significantly lower than intact specimens.

Objetivo: Evaluar el efecto de diferentes tratamientos superficiales mecánicos sobre la resistencia a la flexión de la base de la prótesis reparada. Material y Métodos: Se fabricaron sesenta especímenes en forma de barra de resina acrílica termo-polimerizada y se dividieron en seis grupos (n=10). Todas las muestras, excepto el grupo de control positivo (grupo PC), se seccionaron en mitades para crear un espacio libre de 1 mm. También se consideró un grupo de control negativo sin tratamiento superficial (grupo NC). Otros grupos se sometieron a diferentes tratamientos superficiales: grupo Láser; tratados con láser de erbio: itrio-aluminio-granate (Er:YAG), grupo APA; abrasión por partículas en el aire (APA), grupo APA más láser; una combinación de láser y APA, y grupo Bur; molienda de fresas. Después de medir la rugosidad de la superficie (Ra) con un perfilómetro, todas las muestras seccionadas se repararon con resina acrílica de autopolimerización y se sometieron a termociclado. La prueba de flexión de tres puntos se realizó con una máquina de prueba universal. Los datos se analizaron estadísticamente (α=0,05). Resultados: La rugosidad superficial media de todos los grupos experimentales fue significativamente mayor que la del grupo NC (p<0,05). La resistencia media a la flexión de todos los grupos fue significativamente menor que la del grupo PC (p<0,05). El grupo B tenía una resistencia a la flexión significativamente mayor que los otros grupos tratados en la superficie (p<0,05). El grupo Láser tuvo una resistencia a la flexión significativamente mayor que los grupos APA (p=0,043) y APA más Láser (p=0,023). No se encontró diferencia significativa entre los grupos APA y APA más Láser (p=0,684). Conclusión: Todos los tratamientos superficiales aumentan la rugosidad de la superficie y la resistencia a la flexión en comparación con el grupo sin tratar. La resistencia a la flexión más alta se observó en las muestras tratadas con fresado y luego con láser; sin embargo, aún era significativamente más baja que las muestras intactas.

The effectiveness of laser vitreolysis for vitreous floaters in posterior vitreous detachment

Purpose: To determine the effectiveness of laser vitreolysis in terms of contrast sensitivity function (CSF) and vision?related quality of life (VRQol) for symptomatic floaters due to posterior vitreous detachment (PVD). Materials: This is an interventional study that involved 57 eyes of 45 patients with symptomatic floaters for more than 3 months. Patients underwent one to three sessions of vitreolysis via Neodymiun?doped Yttrium Aluminum Garnet (Nd:YAG) laser. We examined the CSF using the computer programs Freiburg Acuity and Contrast Test (FrACT) and VRQoL survey using the National Eye Institute Visual Function Questionnaire?25 (NEI VFQ?25) before, and 1 month after, vitreolysis. Results: Twelve patients had both eyes lasered and 33 patients had one eye lasered. The mean CSF improved from 3.20 ± 0.85%W to 2.64 ± 0.63%W 1 month after vitreolysis. Each use of the laser showed a significant mean difference in CSF (%W) as analyzed by paired t?test before and after the first laser (0.29 ± 0.49%W [P ? 0.001]); after the first and second laser (0.35 ± 0.53%W [P = 0.01]); and after second and third laser (0.21 ± 0.31%W [P = 0.02]). There was improvement in the median of four subscales in NEI VFQ?25 scores post treatment: general vision (z = ?3.30, P = 0.001), near activity (z = 3.396, P = 0.001, distance activity (z = ?2.788, P = 0.005), and mental health (z = ?2.219, P = 0.026). The mean scores increased to 79.55 ± 9.45 from the baseline 75.06 ± 9.69 (P ? 0.001). No adverse events were recorded 1 month after the laser treatments. Conclusion: Vitreolysis by Nd:YAG laser improved the CFS and VRQoL in symptomatic PVD patients.

Chinese expert consensus on selective internal radiation therapy with yttrium-90 for primary and metastatic hepatocellular carcinoma / 中华肝脏病杂志

Liver malignant tumors are one of the most common causes of cancer-related deaths in China. Selective internal yttrium-90 radioembolization therapy ((90)Y-SIRT) is a kind of promising local minimally invasive method, and its effectiveness and safety has been confirmed in clinical application over the past two decades. Moreover, it has been approved by the U.S. National Comprehensive Cancer Network and other international guidelines for the topical treatment of patients with liver malignancies. Taking into account the complexity of the (90)Y-SIRT and the need for multidisciplinary collaboration to improve the safety and success rate of treatment, the Nuclear Medicine Expert Committee of the Chinese society of Clinical Oncology, along with Beijing Nuclear Medicine Quality Control and Improvement Center invited experts from surgical oncology, interventional medicine, nuclear medicine, and other related fields to discuss and form a consensus on the clinical diagnosis, treatment and management, which mainly included definition, indications and contraindications, treatment procedures, postoperative follow-up, adverse reactions and complications, radiation safety management, etc. Herein, we provide the reference guidance to establish (90)Y-SIRT standardized management and treatment system various units for relevant practitioners.

Hallazgos histológicos asociados a gingivectomía con láser de Er, Cr: YSGG (2780 nm) / Histological Findings' Associated with Gingivectomy with Er, Cr: YSGG (2780 nm) Laser

RESUMEN Introducción: Al realizar una intervención quirúrgica, el instrumento de corte utilizado cobra especial importancia, pues el mismo está vinculado a los signos y síntomas intra- y posoperatorios y al tiempo de reparación de los tejidos. En respuesta a esto, con el tiempo se han propuesto nuevos instrumentos, particularmente la tecnología láser ha venido sufriendo un avance rápido y significativo y en la actualidad se utiliza para un sinnúmero de tratamientos odontológicos. Al láser se le han atribuido diferentes ventajas en la cirugía estética periodontal: desde facilitar el proceso de hemostasia, hasta la estimulación del proceso de reparación tisular. Sin embargo, es pertinente realizar estudios que demuestren a nivel histológico los cambios que generan en la mucosa oral y obtener información que permita conocer de qué manera influye en el proceso de reparación del tejido. Objetivo: Describir los hallazgos histológicos asociados al corte con láser de Er, Cr: YSGG de 2780 nm en muestras de encía obtenidas mediante gingivectomía. Presentación del caso: Paciente femenina, de 21 años, sistémicamente sana. Asistió a la consulta por presentar por inconformidad estética al sonreír. Se diagnosticó con exposición de banda de encía queratinizada mayor que 4 mm. Como parte del plan de tratamiento se indicó gingivectomía con láser de Er, Cr: YSGG (2780 nm) (Waterlase®, BIOLASE®), el procedimiento se realizó solo bajo anestesia tópica. Se tomaron muestras histológicas de tejido gingival para análisis histológico. Conclusiones: El láser Er, Cr: YSGG (2780 nm) preservó la morfología de los fibroblastos después del corte, no hubo evidencia de carbonización, ni profundización de la lesión térmica en el tejido. Este instrumento fue una herramienta de gran utilidad para la ejecución del tratamiento en este caso. Tuvo ventajas importantes como la ausencia de dolor posoperatorio, buena hemostasia y la reparación epitelial casi completa en tan solo 4 días(AU)

ABSTRACT Introduction: When performing a surgical intervention, the cutting instrument used is especially important, since it is associated with intraoperative and postoperative signs and symptoms and to the time of tissue repair. In response to this, new instruments have been proposed over time, particularly laser technology has been undergoing rapid and significant advancement and is currently used for countless dental treatments. Laser has been attributed different advantages in periodontal cosmetic surgery: from facilitating the hemostasis process, to stimulating the tissue repair process. However, it is pertinent to carry out studies that prove, at histological level, the changes in the oral mucosa and obtain information that allows us to know how it influences the tissue repair process. Objective: To describe the histological findings associated with the Er, Cr: YSGG (2780 nm) laser cut in gum samples obtained by gingivectomy. Case presentation: Female patient, 21 years old, systemically healthy. She attended the consultation for presenting aesthetic dissatisfaction when smiling. She was diagnosed with exposure of keratinized gum band greater than 4 mm. As part of the treatment plan, Er, Cr: YSGG (Waterlase®, BIOLASE®, 2780 nm) laser gingivectomy was indicated. The procedure was performed only under topical anesthesia. Histological samples of gingival tissue were taken for histological analysis. Conclusions: The Er, Cr: YSGG (2780 nm) laser preserved the morphology of the fibroblasts after the cut. There was no evidence of carbonization or deepening of the thermal injury in the tissue. In this case, this instrument was a very useful tool for the performance of the treatment. It had important advantages, such as the absence of postoperative pain, good hemostasis, and almost complete epithelial repair in just four days(AU)

25 años de CENTIS. Pandemia y Radiofármacos / 25 years of CENTIS. Pandemic and Radiopharmaceuticals

Resumen Próximo a su 25 aniversario CENTIS reflexiona sobre su quehacer en el contexto de los trastornos que causa la COVID-19. Con ese propósito se examinan el estado de la medicina nuclear y la radiofarmacia antes y durante la epidemia y sus perspectivas de desarrollo. La producción global de radiofármacos continúa siendo una industria consolidada y aunque la pandemia afecta a esta esfera, la presencia de otras enfermedades no cesa, por lo que los servicios de medicina nuclear esenciales y críticos siguen siendo necesarios. Se espera su paulatina reapertura y que se retome con más fuerza la investigación, dado que la COVID-19 es tan compleja y se asocia a tantos factores que constituye, en perspectiva, terreno virgen para las técnicas diagnósticas en medicina nuclear. Ha de permanecer asimismo el papel de los radiofármacos terapéuticos en un grupo importante de enfermedades, en cáncer sobre todo. El Centro de Isótopos pone por ello énfasis tanto en la consolidación, bajo buenas prácticas, de la producción y el suministro de radiofármacos, como en el desarrollo de nuevos productos. Ambos aspectos se basan principalmente en dos radionúclidos: Tc-99m e Y-90.

Abstract Close to its 25th anniversary, CENTIS evaluates its work in the context of the disorders triggered by COVID-19. For this purpose, the situation of nuclear medicine and radiopharmacy, before and during the epidemic and their current development prospects is examined. The production of radiopharmaceuticals continues to be a consolidated global industry and although the pandemic affects this area, the presence of other diseases does not cease, so essential and critical nuclear medicine services are still needed, therefore its gradual reopening is expected. In addition, research will be taken with more strength, given that COVID-19 is so complex and associated with so many factors that it constitutes virgin terrain in perspective for diagnostic techniques in nuclear medicine. The role of therapeutic radiopharmaceuticals in an important set of diseases, especially cancer, will also remain. As a result, the Isotope Center focus its attention under good management practices, on the consolidation of the production and distribution of radiopharmaceuticals and in the development of new products. Both aspects are mainly based on two radionuclides: Tc-99m and Y-90.

Effect of Er: YAG laser irradiation on the bonding strength of permanent teeth / 口腔疾病防治

@#The concept of “minimally invasive dentistry” aims to provide conservative treatment of cavities in which sound dentin is removed. Because the Er: YAG laser can selectively remove caries, the smear layer is removed, dentin tubules are exposed after the preparation of substrate conditioning, and its advantages of precision, safety and painlessness are deeply valued. At the same time, the bonding strength between the prepared dentin surface and the filling material is different due to the different parameters of the Er: YAG laser. In this paper, the principle of dentin bonding, the mechanism of Er: YAG laser action, after treatment of dentin with different parameters (power, energy density, pulse duration, and irradiation distance), whether there is thermal damage to pulp tissue, the ultramicro morphology of dentin surface, the bonding properties of different bonding systems and the filling materials between irradiated hard tissues were reviewed. An appropriate parameter range (power ≤ 10 Hz, energy density ≤ 60 mJ, and pulse duration ≤ 50 μs) combined with water spray cooling will not cause thermal damage to the pulp tissue, while the higher power, energy density and pulse duration of laser treatment for dentin will lead to melting, carbonization, cracks, narrowing of the gap between collagen fibers, etc., which will limit the penetration of adhesives and have a negative impact on bonding. However, whether the adhesive systems based on the smear layer are suitable for dentin after laser treatment needs to be further explored.

Zirconia in Dental and Other Biomedical Applications: An Overview

An extensive range of biocompatible materials has been used in patients. Diverse biomedical applications demand different properties of materials, implicating mechanical, physical, chemical, and biochemical properties. Amongst biocompatible ceramics, zirconia-based biomaterials are considered as a biomaterial for retexture of hard tissues related to their excellent mechanical properties and good biological and chemical compatibilities. Zirconia is used in dentistry and in orthopedics, specifically in the area of femoral heads for total hip replacements.

The contribution of ceramic thickness and adhesive type on the de-bonding strength of dental ceramic veneers using Er, Cr: YSGG laser / La contribución del espesor de la cerámica y el tipo de adhesivo a la resistencia de desunión de las carillas dentales de cerámica con láser Er, Cr: YSGG

Purpose: De-bonding strength of ceramic veneers by laser use needs to be evaluated in detail. The aim of this study, is to determine the contribution of ceramic thickness and cementing agents to the de-bonding strength of ceramic veneers using Er,Cr:YSGG laser. Methods: A total of 120 maxillary central incisors specimens were randomly divided into twelve groups on the basis of disc thickness, cementing agent, and Er,Cr:YSGG laser use. Under laboratory conditions, 120 IPS Empress II system discs 0.5mm, 1mm, and 2mm in thickness were applied to the tooth surfaces, for laser use. An Er,Cr:YSGG laser system was applied to the central surface of the IPS Empress II discs on specimens in all laser groups (Groups 1,3,5,7,9,11). Then the shear bond strength (SBS) for all specimens were tested with a testing machine at a speed of 0.5mm/min. The SBS values were considered as the de-bonding strength. Results: The mean de-bonding strength values for Groups 9 and 11 (0,5 mm disc thickness + laser application) have the lowest median load (0.000 N), while Group 4 (2mm disc thickness + no laser) has the highest median load (573.885 N). The de-bonding strengths of all the groups without laser application were higher than those of all groups with laser use. When laser is applied, the mean de-bonding strength decreases with decreasing disc thickness, and it reaches zero at 0.5mm thickness of discs cemented by self- or total-etch adhesives. Conclusions: The de-bonding strength decreases with laser use, and decreasing disc thickness. In the absence of laser, the mean de-bonding values of discs cemented by a total etch adhesive system are always higher than those of discs cemented with a self-etch adhesive system. Without any extra load, all 0.5mm thick discs were dislodged from teeth while applying or testing the laser.

Propósito: La resistencia de desunión de las carillas de cerámica mediante el uso del láser debe evaluarse en detalle. El objetivo de este estudio es determinar la contribución del espesor de la cerámica y los agentes de cementación a la resistencia de desunión de las carillas de cerámica utilizando el láser Er, Cr: YSGG. Métodos: Un total de 120 incisivos centrales maxilares se dividieron al azar en doce grupos según el grosor del disco, el agente de cementación y el uso del láser Er, Cr: YSGG. En condiciones de laboratorio, se aplicaron en las superficies de los dientes 120 discos del sistema IPS Empress II de 0,5mm, 1mm y 2mm de grosor, para uso con láser. Se aplicó un sistema láser Er, Cr: YSGG a la superficie central de los discos IPS Empress II en muestras de todos los grupos de láser (Grupos 1,3,5,7,9,11). Luego, la resistencia de la unión al cizallamiento (SBS) para todas las muestras se probó con una máquina de prueba a una velocidad de 0.5mm/min. Los valores de SBS se consideraron como la fuerza de desunión. Resultados: Los valores medios de resistencia de desunión para los Grupos 9 y 11 (espesor de disco de 0,5mm + aplicación de láser) demostró la carga media más baja (0,000 N), mientras que el Grupo 4 (espesor de disco de 2 mm + sin láser) tuvo la carga media más alta (573.885 N). Las fuerzas de desunión de todos los grupos sin aplicación de láser fueron superiores a las de todos los grupos con uso de láser. Cuando se aplica el láser, la fuerza media de desunión disminuye al disminuir el grosor del disco, y llega a cero con el grosor de 0,5mm de los discos cementados, para ambos adhesivos de grabado. Conclusiones: la fuerza de desunión disminuye con el uso del láser y disminuye con el grosor del disco. En ausencia de láser, los valores medios de desunión de los discos cementados con un sistema de adhesivo de grabado total son siempre más altos que los de los discos cementados con un sistema de adhesivo de autograbado. Sin ninguna carga adicional, todos los discos de 0,5mm de grosor se desprendieron de los dientes al aplicar el láser.

Autologous noncultured melanocyte-keratinocyte transplantation in stable vitiligo: A randomized comparative study of recipient site preparation by two techniques

Background: Accurate preparation of recipient area is a critical step in melanocyte-keratinocyte transplantation procedure for vitiligo. It is an important potential step for adaptation in the quest to achieve better results and ablative lasers potentially offer excellent precision over margin and depth control in achieving that. Objective: To compare between the two techniques used for recipient site preparation: Er:YAG laser ablation and mechanical dermabrasion for melanocyte-keratinocyte transplantation procedure in terms of re-pigmentation achieved and adverse effects seen. Methods: A randomized comparative trial was performed among 32 patients of stable vitiligo undergoing melanocyte-keratinocyte transplantation procedure. In Group A (n = 15), recipient site preparation was done with Er:YAG laser, and in Group B (n = 17), it was done with a motorized dermabrader. Patients of both groups were objectively assessed for re-pigmentation at 1, 3 and 6 months. Results: A total of 253.696 cm2 of depigmented surface was operated upon and re-pigmentation of 125.359 cm2 (49.4%) was achieved. On comparison between two groups, no statistical difference was found with respect to total re-pigmentation achieved (Group A: 54.67% vs Group B: 48.841%, P = 0.663) and grades of re-pigmentation achieved (P = 0.796). Occurrence of adverse events was also statistically similar in both the groups. Conclusion: This study did not reveal any statistically different outcome (in terms of re-pigmentation and adverse effects) between the two methods of recipient site preparation – motorized dermabrasion and Er:YAG ablation. Limitations: This study is small and larger studies are needed to ascertain the benefit of Er:YAG for recipient site preparation. Future studies may also ascertain variables such as time taken to prepare the recipient area, nature of bleeding, postoperative healing, difficulties in specific area, cost of the procedure, patient comfort and ease of the surgeon, rather than comparing the re-pigmentation alone.

Yttrium-90 radioembolization for unresectable liver metastases of melanoma: efficacy and safety / 中华肝胆外科杂志

Studies correlated with yttrium-90 (90Y) radioembolization for unresectable liver metastases of melanoma (LMM) were analyzed during January 1st, 1991 to September 1st, 2018. A total of 9 reports involving 207 patients were included for the analysis. The most common primary site of melanoma was choroid, followed by cutaneous and rectal. A total of 199 cases were followed-up, and in 181 patient the complete response rate was 1.1%(2/181), partial response rate was 18.2%(33/181), stable disease rate was 46.4%(84/181), and cancer control rate was 65.7%(119/181). The median survival was 10 months. Complications were found in 42 cases (21.5%, 42/195), including radioembolization induced liver disease (n=39), gastric ulceration (n=2), cholecystitis (n=1), and liver failure (n=3). Adverse reaction included fatigue (14.3%~44.0%), nausea (6.3%~23.0%), and abdominal pain (7.0%~38.0%). 90Y radioembolization is a promising alternative therapy for the treatment of unresectable LMM, with encouraging effects on disease control and survival. Some complications can occur, and adverse reaction are frequent but mild.

Efficacy and safety of yttrium-90 radioembolization for unresectable hepatocellular carcinoma: A systematic review and meta analysis / 解放军医学杂志

Objective To compare the efficacy and safety of yttrium-90 (Y-90 or 90Y) radioembolization for unresectable HCC using randomized clinical trials. Methods We reviewed data from the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase to collect randomized controlled trials about Y-90 radioembolization for unresectable HCC. We also checked reference lists of primary original studies and review manually-searched articles for further related articles up to September 30, 2018. Summarized odds ratio (OR) or hazard ratio (HR) with 95% confidence intervals (CI) were used to assess the differences in outcomes. Results A total of 6 randomized controlled trials containing 956 patients with unresectable HCC were included in this analysis. Y-90 microsphere radioembolisation was associated with a higher response rate (OR=1.76, 95% CI 1.07- 2.90, P=0.03), and showed a significantly larger decrease in haemorrhage (OR=0.26, 95% CI 0.11-0.61, P=0.02), hypertension (OR=0.17, 95% CI 0.08-0.38, P0.05). Conclusions Y-90 microsphere radioembolisation seems to be a safe and effective treatment for patients with unresectable hepatocellular carcinoma due to its higher response rate and reduced the adverse event rates as haemorrhage, hypertension and infection. However, further randomized clinical trials are mandatory to better assess the potential beneficial and harmful outcomes of Y-90 microsphere by arterial radioembolisation in the patients with unresectable hepatocellular carcinoma.

Radioembolization for the Treatment of Primary and Metastatic Liver Cancers / 대한핵의학회잡지

Radioembolization using ⁹⁰Y microspheres (glass or resin) has been introduced as an effective intraarterial therapy for unresectable primary and metastatic liver cancers. Although the basic therapeutic effect of chemoembolization results from ischemia, the therapeutic efficacy of radioembolization comes from radiation. Furthermore, compared with surgical resection and local ablation therapy, radioembolization is available with less limitation on the sites or number of liver cancers. The radioisotope ⁹⁰Y is a β-radiation emitter without γ-radiation, with the emission of secondary bremsstrahlung photons and small numbers of positrons. Administration of ⁹⁰Y microspheres into the hepatic artery can deliver a high dose of radiation selectively to the target tumor with limited radiation exposure to the surrounding normal parenchyma, and has low systemic toxicity. In general, radioembolization has been considered for patients with unresectable primary or metastatic liver-only or liver-dominant cancers with no ascites or other clinical signs of liver failure, life expectancy of > 12 weeks, and good performance status. Here, we review the current radioactive compounds, pretreatment assessment, and indications for radioembolization in patients with hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and liver metastases from colorectal cancer.

Effect of ME Collimator Characteristic, Energy Window Width, and Reconstruction Algorithm Selection on Imaging Performance of Yttrium-90: Simulation Study / 대한핵의학회잡지

PURPOSE: The treatment efficiency of ⁹⁰Y and providing reliable estimates of activity are evaluated by SPECT imaging of bremsstrahlung radiation released during beta therapy. In this technique, the resulting spectrum from ⁹⁰Y is very complex and continuous, which creates difficulties on the imaging protocol. Moreover, collimator geometry has an impressive effect on the spatial resolution, system sensitivity, image contrast, and the signal-to-noise ratio (SNR), which should be optimized.METHODS: We evaluated the effect of energy window width, reconstruction algorithms, and different geometries of a medium-energy (ME) parallel-hole collimator on the image contrast and SNR of ⁹⁰Y SPECT images. The Siemens E.Cam gamma camera equipped with a ME collimator and a digital Jaszczak phantom were simulated by SIMIND Monte Carlo program to generate the ⁹⁰Y bremsstrahlung SPECT images.RESULTS: Our results showed that optimal image quality can be acquired by the reconstruction algorithm of OS-EM in the energy window width of 60 to 400 keV for ⁹⁰Y bremsstrahlung SPECT imaging. Furthermore, the optimal values of the hole diameter and hole length of a ME collimator were obtained 0.235 and 4.4 cm, respectively.CONCLUSIONS: The acquired optimal ME collimator and energy window along with using a suitable reconstruction algorithm lead to improved contrast and SNR of ⁹⁰Y bremsstrahlung images of hot spheres of the digital Jaszczak phantom. This can improve the accuracy and precision of the ⁹⁰Y activity distribution estimation after radioembolization in targeted radionuclide therapy.

Current Status and Growth of Nuclear Theranostics in Singapore / 대한핵의학회잡지

The concept of theranostics, where individual patient-level biological information is used to choose the optimal therapy for that individual, has become more popular in the modern era of ‘personalised’ medicine. With the growth of theranostics, nuclear medicine as a specialty is uniquely poised to grow along with the ever-increasing number of concepts combining imaging and therapy. This special report summarises the status and growth of Theranostic Nuclear Medicine in Singapore.We will cover our experience with the use of radioiodine, radioiodinated metaiodobenzylguanidine, peptide receptor radionuclide therapy, prostate specific membrane antigen radioligand therapy, radium-223 and yttrium-90 selective internal radiation therapy.We also include a section on our radiopharmacy laboratory, crucial to our implementation of theranostic principles. Radionuclide theranostics has seen tremendous growth and we hope to be able to grow alongside to continue to serve the patients in Singapore and in the region.

Yttrium-90 radioembolization for unresectable liver metastases of melanoma:efficacy and safety / 中华肝胆外科杂志

Studies correlated with yttrium-90 ( 90 Y) radioembolization for unresectable liver metasta-ses of melanoma ( LMM) were analyzed during January 1st, 1991 to September 1st, 2018. A total of 9 reports involving 207 patients were included for the analysis. The most common primary site of melanoma was choroid, followed by cutaneous and rectal. A total of 199 cases were followed-up, and in 181 patient the complete response rate was 1. 1％(2/181), partial response rate was 18. 2％(33/181), stable disease rate was 46. 4％ ( 84/181 ) , and cancer control rate was 65. 7％ ( 119/181 ) . The median survival was 10 months. Complications were found in 42 cases (21. 5％, 42/195), including radioembolization induced liver disease ( n =39 ) , gastric ulceration ( n =2 ) , cholecystitis ( n =1 ) , and liver failure ( n =3 ) . Adverse reaction included fatigue ( 14. 3％ ～44. 0％) , nausea ( 6. 3％ ～23. 0％) , and abdominal pain (7. 0％ ～38. 0％). 90Y radioembolization is a promising alternative therapy for the treatment of unresectable LMM, with encouraging effects on disease control and survival. Some complications can occur, and adverse reaction are frequent but mild.

Y-TZP surface treatments and their effects on the bond strength to resin cement

Aim: This study evaluated the effect of surface treatments of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics on their bond strength to a resin cement. Methods: Seventy zirconia blocks (6 × 6 × 2 mm3, IPS e.max ZirCAD) were assigned into 7 groups (n=10) ­ as-sintered (AS), no treatment; tribochemical silica coating + silanization (TBS; Cojet-sand; ProSil); airabrasion with 45 µm alumina particles + universal primer (AAP; Monobond®Plus); fusion sputtering (FS); SiO2 nanofilm + silanization (SN; ProSil); FS+SN+ silanization (FSSN; ProSil); FS+SN+Universal Primer (FSSNP; Monobond®Plus). Afterwards, a resin cement (RelyX™ ARC) was applied inside cylinders (Ø = 0.96 mm × 1 mm height) placed on the zirconia surfaces. Microshear bond strength tests (µSBS) were carried out (1 mm/min). Failure and phase transformation analysis were performed. Bond strength data (MPa) were subjected to Kruskal-Wallis/Mann Whitney tests. Results: TBS (27 ± 1.2) and AAP (24.7 ± 0.8) showed higher bond strengths than the other groups, followed by FSSNP (15.5 ± 4.2) and FSSN (13.3 ± 3.6). FS (3.4 ± 0.44) and SN (9.5 ± 2.7) showed the lowest values (p < 0.001). Most of the specimens exhibited an adhesive failure. Conclusion: Air-abrasion by silica-coated alumina particles followed by silanization or by alumina particles followed by universal primer resulted in the highest resin bond strength to zirconia. Fusion sputtering and silica nanofilm deposition induced low strengths. However, when these methods are applied in combination and with a primer (FSSN and FSSNP), higher bond strengths may be achieved. Low bond strengths are obtained when no zirconia treatment is performed

Evaluation of Early Response to Treatment of Hepatocellular Carcinoma with Yttrium-90 Radioembolization Using Quantitative Computed Tomography Analysis

OBJECTIVE: To identify an imaging predictor for the assessment of early treatment response to yttrium-90 transarterial radioembolization (TARE) in patients with hepatocellular carcinoma (HCC), using a quantitative assessment of dynamic computed tomography (CT) images. MATERIALS AND METHODS: Dynamic contrast-enhanced CT was obtained pre- and 4 weeks post-TARE in 44 patients (34 men, 10 women; mean age, 60 years) with HCC. Computer software was developed for measuring the percentage increase in the combined delayed-enhancing area and necrotic area (pD + N) and the percentage increase in the necrotic area (pNI) in the tumor-containing segments pre- and post-TARE. Local progression-free survival (PFS) was compared between patient groups using Cox regression and Kaplan-Meier analyses. RESULTS: Post-TARE HCC with pD + N ≥ 35.5% showed significantly longer PFS than those with pD + N < 35.5% (p = 0.001). The local tumor progression hazard ratio was 17.3 (p = 0.009) for pD + N < 35.5% versus pD + N ≥ 35.5% groups. HCCs with a high pNI tended to have longer PFS, although this difference did not reach statistical significance. CONCLUSION: HCCs with a larger pD + N are less likely to develop local progression after TARE.

Hepatocellular Carcinoma with Segmental Portal Vein Invasion Exhibiting a Complete Response after Transarterial Radioembolization

The treatment options available for patients with hepatocellular carcinoma (HCC) with portal vein invasion (PVI) include sorafenib, transarterial radioembolization (TARE), radiation therapy (RT), transarterial chemoembolization with RT, and proton beam irradiation. Herein, we present a case of HCC with segmental PVI that was managed via TARE. The patient had a 4 cm HCC that invaded the segment VIII portal vein branch without extrahepatic spread. Liver function was Child-Pugh grade A, and performance status was good. TARE was performed without any adverse events, and a radiological complete response (CR) was achieved. Thereafter, the patient was followed-up every 3–6 months without any further treatment, and the CR was maintained for >3 years. Therefore, TARE may be a useful alternative therapeutic option for patients with HCC exhibiting segmental PVI.