Radioactive Seed Localization for Nonpalpable Breast Lesions: Systematic Review and Meta-Analysis

BACKGROUND

This study is a systematic review with meta-analysis comparing radioactive seed localization (RSL) versus radio-guided occult lesion localization (ROLL) and wire-guided localization (WGL) for patients with impalpable breast cancer undergoing breast-conserving surgery and evaluating efficacy, safety, and logistical outcomes. The protocol is registered in PROSPERO with the number CRD42022299726.

METHODS

A search was conducted in the Embase, Lilacs, Pubmed, Scielo, Web of Science, and clinicaltrials.gov databases, in addition to a manual search in the reference list of relevant articles, for randomized clinical trials and cohort studies. Studies selected were submitted to their own data extraction forms and risk of bias analysis according to the ROB 2 and ROBINS 1 tools. A meta-analysis was performed, considering the random effect model, calculating the relative risk or the mean difference for dichotomous or continuous data, respectively. The quality of the evidence generated was analyzed by outcome according to the GRADE tool. Overall, 46 articles met the inclusion criteria and were included in this systematic review; of these, 4 studies compared RSL and ROLL with a population of 1550 women, and 43 compared RSL and WGL with a population of 19,820 women.

RESULTS

The results showed that RSL is a superior method to WGL in terms of surgical efficiency in the impalpable breast lesions' intraoperative localization, and it is at least equivalent to ROLL. Regarding security, RSL obtained results equivalent to the already established technique, the WGL. In addition to presenting promising results, RSL has been proven to be superior to WGL and ROLL technologies.

Could Light-Based Technologies Improve Stem Cell Therapy for Skin Wounds? A Systematic Review and Meta-Analysis of Preclinical Studies

Several diseases or conditions cause dermatological disorders that hinder the process of skin repair. The search for novel technologies has inspired the combination of stem cell (SC) and light-based therapies to ameliorate skin wound repair. Herein, we systematically revised the impact of photobiomodulation therapy (PBM) combined with SCs in animal models of skin wounds and quantitatively evaluated this effect through a meta-analysis. For inclusion, SCs should be irradiated in vitro or in vivo, before or after being implanted in animals, respectively. The search resulted in nine eligible articles, which were assessed for risk of bias. For the meta-analysis, studies were included only when PBM was applied in vivo, five regarding wound closure, and three to wound strength. Overall, a positive influence of SC+PBM on wound closure (MD: 9.69; 95%CI: 5.78 to 13.61, p<0.00001) and strength (SMD: 1.7, 95%CI: 0.68 to 2.72, p=0.001) was detected, although studies have shown moderate to high heterogeneity and a lack of information regarding some bias domains. Altogether, PBM seems to be an enabling technology able to be applied post-implantation of SCs for cutaneous regeneration. Our findings may guide future laboratory and clinical studies in hopes of offering wound care patients a better quality of life.

Environmental Tobacco Smoke During the Early Postnatal Period of Mice Interferes With Brain 18 F-FDG Uptake From Infancy to Early Adulthood - A Longitudinal Study

Exposure to environmental tobacco smoke (ETS) is associated with high morbidity and mortality, mainly in childhood. Our aim was to evaluate the effects of postnatal ETS exposure in the brain 2-deoxy-2-[¹⁸F]-fluoro-D-glucose (¹⁸F-FDG) uptake of mice by positron emission tomography (PET) neuroimaging in a longitudinal study. C57BL/6J mice were exposed to ETS that was generated from 3R4F cigarettes from postnatal day 3 (P3) to P14. PET analyses were performed in male and female mice during infancy (P15), adolescence (P35), and adulthood (P65). We observed that ETS exposure decreased ¹⁸F-FDG uptake in the whole brain, both left and right hemispheres, and frontal cortex in both male and female infant mice, while female infant mice exposed to ETS showed decreased ¹⁸F-FDG uptake in the cerebellum. In addition, all mice showed reduced ¹⁸F-FDG uptake in infancy, compared to adulthood in all analyzed VOIs. In adulthood, ETS exposure during the early postnatal period decreased brain ¹⁸F-FDG uptake in adult male mice in the cortex, striatum, hippocampus, cingulate cortex, and thalamus when compared to control group. ETS induced an increase in ¹⁸F-FDG uptake in adult female mice when compared to control group in the brainstem and cingulate cortex. Moreover, male ETS-exposed animals showed decreased ¹⁸F-FDG uptake when compared to female ETS-exposed in the whole brain, brainstem, cortex, left amygdala, striatum, hippocampus, cingulate cortex, basal forebrain and septum, thalamus, hypothalamus, and midbrain. The present study shows that several brain regions are vulnerable to ETS exposure during the early postnatal period and these effects on ¹⁸F-FDG uptake are observed even a long time after the last exposure. This study corroborates our previous findings, strengthening the idea that exposure to tobacco smoke in a critical period interferes with brain development of mice from late infancy to early adulthood.

Magnetic core mesoporous silica nanoparticles doped with dacarbazine and labelled with 99mTc for early and differential detection of metastatic melanoma by single photon emission computed tomography

Cancer is responsible for more than 12% of all causes of death in the world, with an annual death rate of more than 7 million people. In this scenario melanoma is one of the most aggressive ones with serious limitation in early detection and therapy. In this direction we developed, characterized and tested in vivo a new drug delivery system based on magnetic core-mesoporous silica nanoparticle that has been doped with dacarbazine and labelled with technetium 99 m to be used as nano-imaging agent (nanoradiopharmaceutical) for early and differential diagnosis and melanoma by single photon emission computed tomography. The results demonstrated the ability of the magnetic core-mesoporous silica to be efficiently (>98%) doped with dacarbazine and also efficiently labelled with 99mTc (technetium 99 m) (>99%). The in vivo test, using inducted mice with melanoma, demonstrated the EPR effect of the magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable when injected intratumorally and the possibility to be used as systemic injection too. In both cases, magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable showed to be a reliable and efficient nano-imaging agent for melanoma.

Abstract 2408: Melatonin action in xenograft model of breast cancer, comparing radiopharmaceuticals in the detection of intratumor heterogeneity by PET/CT confirmed by immunohistochemical markers

Breast cancer is the most common cancer among women and has a high mortality rate. The rapid tumor growth makes difficult the perfusion of O2 mainly in the tumor center, and this hypoxia in tumor microenvironment can exerts selective pressure on the tumor cells, selecting subpopulations with advantage for survival in adverse conditions, characterizing the intratumor heterogeneity. In this context, melatonin, a hormone naturally produced by the pineal gland, has shown antitumor activity, as immunomodulatory, antioxidant, pro-apoptotic, anti-proliferative, antimetastatic, antiangiogenic and with potencial effects in intratumor heterogeneity. The aims of this study was to evaluate the effectiveness of melatonin in a xenograft model of breast cancer, focusing on intratumor heterogeneity verified by PET/CT and by immunohistochemical markers of hypoxia. The tumors were developed by the implantation of 5 million triple-negative breast cancer cells (MDA-MB-231) into the flank of female Balb/c nude mice (n = 14). Treatment with melatonin (n = 7) or vehicle (n = 7) was initiated 10 days after tumor implantation and continued for 14 days. At the end, micro-PET/CT scanning was performed with 18F-FDG, which is an analogue of glucose, and with 18F-FAZA, a specific radiopharmaceutical for hypoxia detection. The radiopharmaceuticals were injected by retro-orbital via and the images were acquired using Albira PET/SPECT/CT Carestream Molecular Imaging. Then, markers of hypoxia were evaluated by immunohistochemistry in mammary tumors. The results showed that tumor growth in animals treated with melatonin was lower than those treated with vehicle (p&lt;0.05). There was tumor regression in one animal treated with melatonin, showing 18.72 mm3 at start of treatment and no longer being detected after seven days of treatment. 18F-FDG can be used as hypoxia marker, however, studies show that can occurs overlapping areas of aerobic and anaerobic glycolysis in the tumor, difficulting the identification of hypoxic areas. 18F-FAZA has a hypoxia-specific uptake mechanism and a better spread by the tumor. Results of PET/CT showed that 18F-FDG had homogeneous uptake in breast tumors. In some tumors with high volume, there was no uptake in the tumor center, corresponding to areas of necrosis. In addition, there was an intratumor 18F-FAZA uptake heterogeneity, indicating possible hypoxic areas. Also, PET/CT results showed that there was less hypoxic areas in animals treated with melatonin, which was confirmed by immunohistochemical markers. Taken together, our results showed an important action of melatonin, in control of mammary tumor growth, decreasing hypoxia areas and controlling cancer progression. Financial support: Fundação de Amparo à Pesquisa do Estado de São Paulo

Citation Format: André L. Mota, Bruna V. Jardim-Perassi, Thaiz F. Borin, Nathália M. Sonehara, Lorena Pozzo, Emerson S. Bernardes, Bruno Cogliati, Debora APC Zuccari. Melatonin action in xenograft model of breast cancer, comparing radiopharmaceuticals in the detection of intratumor heterogeneity by PET/CT confirmed by immunohistochemical markers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2408.

Multi-centre evaluation of accuracy and reproducibility of planar and SPECT image quantification: An IAEA phantom study

Accurate quantitation of activity provides the basis for internal dosimetry of targeted radionuclide therapies. This study investigated quantitative imaging capabilities at sites with a variety of experience and equipment and assessed levels of errors in activity quantitation in Single-Photon Emission Computed Tomography (SPECT) and planar imaging. Participants from 9 countries took part in a comparison in which planar, SPECT and SPECT with X ray computed tomography (SPECT-CT) imaging were used to quantify activities of four epoxy-filled cylinders containing ¹³³Ba, which was chosen as a surrogate for ¹³¹I. The sources, with nominal volumes of 2, 4, 6 and 23mL, were calibrated for ¹³³Ba activity by the National Institute of Standards and Technology, but the activity was initially unknown to the participants. Imaging was performed in a cylindrical phantom filled with water. Two trials were carried out in which the participants first estimated the activities using their local standard protocols, and then repeated the measurements using a standardized acquisition and analysis protocol. Finally, processing of the imaging data from the second trial was repeated by a single centre using a fixed protocol. In the first trial, the activities were underestimated by about 15% with planar imaging. SPECT with Chang's first order attenuation correction (Chang-AC) and SPECT-CT overestimated the activity by about 10%. The second trial showed moderate improvements in accuracy and variability. Planar imaging was subject to methodological errors, e.g., in the use of a transmission scan for attenuation correction. The use of Chang-AC was subject to variability from the definition of phantom contours. The project demonstrated the need for training and standardized protocols to achieve good levels of quantitative accuracy and precision in a multicentre setting. Absolute quantification of simple objects with no background was possible with the strictest protocol to about 6% with planar imaging and SPECT (with Chang-AC) and within 2% for SPECT-CT.

SUS in nuclear medicine in Brazil: analysis and comparison of data provided by Datasus and CNEN

Objective

To investigate the outpatient access to nuclear medicine procedures by means of the Brazilian Unified Health System (SUS), analyzing the correspondence between data provided by this system and those from Comissão Nacional de Energia Nuclear (CNEN) (National Commission of Nuclear Energy).

Materials and Methods

Data provided by Datasus regarding number of scintillation chambers, outpatient procedures performed from 2008 to 2012, administrative responsibility for such procedures, type of service providers and outsourced services were retrieved and evaluated. Also, such data were compared with those from institutions certified by CNEN.

Results

The present study demonstrated that the system still lacks maturity in terms of correct data input, particularly regarding equipment available. It was possible to list the most common procedures and check the growth of the specialty along the study period. Private centers are responsible for most of the procedures covered and reimbursed by SUS. However, many healthcare facilities are not certified by CNEN.

Conclusion

Datasus provides relevant data for analysis as done in the present study, although some issues still require attention. The present study has quantitatively depicted the Brazilian reality regarding access to nuclear medicine procedures offered by/for SUS.

Feeding a diet contaminated with ochratoxin A for broiler chickens at the maximum level recommended by the EU for poultry feeds (0.1 mg/kg). 2. Effects on meat quality, oxidative stress, residues and histological traits

The European Commission Recommendation 2006/576/EC indicates that the maximum tolerable level of ochratoxin A (OTA) in poultry feeds is 0.1 mg OTA/kg. Thirty-six 1-day-old male broiler chicks were divided into two groups, a control (basal diet) and an OTA (basal diet + 0.1 mg OTA/kg) group. The OTA concentration was quantified in serum, liver, kidney, breast and thigh samples. The thiobarbituric acid reactive substances (TBARS) content were evaluated in the liver, kidney, breast and thigh samples. The glutathione (GSH) content, and catalase (CAT) and superoxide dismutase (SOD) activity were measured in the liver and kidney samples. Histopathological traits were evaluated for the spleen, bursa of Fabricius and liver samples. Moreover, the chemical composition of the meat was analysed in breast and thigh samples. In the OTA diet-fed animals, a serum OTA concentration of 1.15 ± 0.35 ng/ml was found, and OTA was also detected in kidney and liver at 3.58 ± 0.85 ng OTA/g f.w. and 1.92 ± 0.21 ng OTA/g f.w., respectively. The TBARS content was higher in the kidney of the ochratoxin A group (1.53 ± 0.18 nmol/mg protein vs. 0.91 ± 0.25 nmol/mg protein). Feeding OTA at 0.1 mg OTA/kg also resulted in degenerative lesions in the spleen, bursa of Fabricius and liver. The maximum tolerable level of 0.1 mg OTA/kg, established for poultry feeds by the EU, represents a safe limit for the final consumer, because no OTA residues were found in breast and thigh meat. Even though no clinical signs were noticed in the birds fed the OTA-contaminated diet, moderate histological lesions were observed in the liver, spleen and bursa of Fabricius.

Feeding a diet contaminated with ochratoxin A for chickens at the maximum level recommended by the EU for poultry feeds (0.1 mg/kg). 1. Effects on growth and slaughter performance, haematological and serum traits

The European Commission Recommendation 2006/576/EC, suggests that the maximum level of Ochratoxin A (OTA) in poultry feeds should be set at 0.1 mg OTA/kg. Thirty-six one-day-old male Hubburd broiler chickens were divided into two groups, a Control (basal diet) and an Ochratoxin A (basal diet + 0.1 mg OTA/kg) group. The growth and slaughter performance traits were recorded. The liver, spleen, bursa of Fabricius and thymus weights were measured. The erythrocyte and leukocyte numbers were assayed in blood samples, and the heterophils to lymphocytes (H/L) ratio was determined. Alpha-1-acid glycoprotein (AGP), lysozyme, the total protein and the electrophoretic pattern were evaluated in serum samples. Liver enzymes (alanino aminotransferase, ALT and aspartate aminotransferase, AST) and kidney function parameters (uric acid and creatinine) were quantified. The results revealed that feeding a 0.1 mg OTA/kg contaminated diet to chicks caused a decrease in the absolute thymus weight (p < 0.05) and a lower total protein (p < 0.01), albumin (p < 0.01), alpha (p < 0.05), beta (p = 0.001) and gamma (p = 0.001) globulins serum concentration in the Ochratoxin A group. Moreover, the albumin-to-globulin (A/G) ratio of the OTA-treated animals resulted to be higher (p < 0.05). Feeding broiler chickens, a diet contaminated with the maximum level admitted by the European Commission Recommendation (0.1 mg OTA/kg), did not affect the animal performance, slaughter traits, organ weights, haematological parameters, liver enzyme or renal function parameters concentrations but had an overall immunosuppressant effect, with reduction in the thymus weight and of the total serum protein, albumin, alpha, beta and gamma globulins concentration.

Effects of N,N-dimethylglycine sodium salt on apparent digestibility, vitamin E absorption, and serum proteins in broiler chickens fed a high- or low-fat diet

The objective of this study was to assess the effect of supplementation with sodium salt of N,N-dimethylglycine (DMG-Na) on apparent digestibility (AD) in broiler chickens fed low- and high-fat diets. Twenty-eight 1-d-old broiler chickens were fed one of the dietary treatments: a low-fat diet (LF) or a high-fat diet (HF) supplemented with or without 1,000 mg/kg of DMG-Na. Body weight and feed consumption were recorded at 14 and 35 d of age. Average daily growth, daily feed intake, and feed conversion ratio were calculated. The AD of DM, organic matter (OM), CP, total fat (TF), and α-tocopheryl-acetate were assessed by 2 digestibility trials (at 18-21 and 32-35 d, respectively). Serum protein and plasma α-tocopherol concentrations were assessed at 35 d of age. Final BW, feed intake, carcass, breast, and spleen weight were higher in groups fed LF than HF diets (P = 0.048, P = 0.002, P = 0.039, P < 0.001, P = 0.007, respectively). Liver weight was increased in DMG-Na-unsupplemented groups (P = 0.011) for both fat levels. During the first digestibility trial (18-21 d), the AD of DM (P = 0.023), OM (P = 0.033), CP (P = 0.030), and α-tocopheryl-acetate (P = 0.036) was higher in the DMG-Na-supplemented group than control. Digestibility of total fat was increased by DMG-Na supplementation in the LF groups (P = 0.038). A trend for improvement of digestibility was observed during the second digestibility trial (32-35 d) for DM (P = 0.089), OM (P = 0.051), and CP (P = 0.063) in DMG-Na groups. Total serum proteins (and relative fractions) were positively influenced by DMG-Na supplementation both in LF and HF diets (P = 0.029). Plasma α-tocopherol concentration was higher in groups fed LF than HF diets (P < 0.001).