15 research outputs found
AIRO Breast Cancer Group Best Clinical Practice 2022 Update
Introduction: Breast cancer is the most common tumor in women and represents the leading cause of cancer death. Radiation therapy plays a key-role in the treatment of all breast cancer stages. Therefore, the adoption of evidence-based treatments is warranted, to ensure equity of access and standardization of care in clinical practice.Method: This national document on the highest evidence-based available data was developed and endorsed by the Italian Association of Radiation and Clinical Oncology (AIRO) Breast Cancer Group.We analyzed literature data regarding breast radiation therapy, using the SIGN (Scottish Intercollegiate Guidelines Network) methodology (www.sign.ac.uk). Updated findings from the literature were examined, including the highest levels of evidence (meta-analyses, randomized trials, and international guidelines) with a significant impact on clinical practice. The document deals with the role of radiation therapy in the treatment of primary breast cancer, local relapse, and metastatic disease, with focus on diagnosis, staging, local and systemic therapies, and follow up. Information is given on indications, techniques, total doses, and fractionations.Results: An extensive literature review from 2013 to 2021 was performed. The work was organized according to a general index of different topics and most chapters included individual questions and, when possible, synoptic and summary tables. Indications for radiation therapy in breast cancer were examined and integrated with other oncological treatments. A total of 50 questions were analyzed and answered.Four large areas of interest were investigated: (1) general strategy (multidisciplinary approach, contraindications, preliminary assessments, staging and management of patients with electronic devices); (2) systemic therapy (primary, adjuvant, in metastatic setting); (3) clinical aspects (invasive, non-invasive and micro-invasive carcinoma; particular situations such as young and elderly patients, breast cancer in males and cancer during pregnancy; follow up with possible acute and late toxicities; loco-regional relapse and metastatic disease); (4) technical aspects (radiation after conservative surgery or mastectomy, indications for boost, lymph node radiotherapy and partial breast irradiation).Appendixes about tumor bed boost and breast and lymph nodes contouring were implemented, including a dedicated web application. The scientific work was reviewed and validated by an expert group of breast cancer key-opinion leaders.Conclusions: Optimal breast cancer management requires a multidisciplinary approach sharing therapeutic strategies with the other involved specialists and the patient, within a coordinated and dedicated clinical path. In recent years, the high-level quality radiation therapy has shown a significant impact on local control and survival of breast cancer patients. Therefore, it is necessary to offer and guarantee accurate treatments according to the best standards of evidence-based medicine
Thermo-oxidative resistant nanocomposites containing novel hybrid-nanoparticles based on natural polyphenol and carbon nanotubes
Quercetin (Q), a natural antioxidant molecule, is physically immobilized onto multi-walled carbon nanotubes (CNTs) bearing covalently-linked long-chain alkyl functional groups, and the so obtained hybrid-nanoparticles are used to prepare Ultra High Molecular Weight PolyEthylene-based nanocomposite films with enhanced thermo-oxidation resistance. The effective immobilization of the Q molecules is confirmed by spectroscopic (micro-Raman, ATR-FTIR, and FTIR) and thermo-gravimetric analyses, and the influence of the nanoparticles on the rheological behaviour and thermo-oxidative stability of the nanocomposites are investigated. Rheological analyses (linear viscoelasticity and stress relaxation tests) and morphological observations reveal that the Q-functionalized CNTs disperse better than bare CNTs in the host matrix. Quercetin confirms to be an excellent antioxidant for polyethylene, but the study of the thermo-oxidation behaviour shows that a remarkable stabilizing action only emerges when Q is physically immobilized on the CNTs. In particular, a ten-fold increase of the onset of degradation phenomena in thermo-oxidative environment was found. Such an excellent result is due to a synergic effect stemming from the physical interaction between Q and CNTs, which cannot provide a similar stabilizing action if used separately. In particular, we argue that the process of physical immobilization of the Q molecules causes the formation of structural defects onto outer CNTs surfaces, thus remarkably improving the CNTs radical scavenging activity and probably promoting Q regeneration. In addition, CNTs seem acting as efficient nano-carriers for the quercetin molecules, improving the dispersion of the latter in the host matrix in spite of their poor solubility
Nano-hybrids based on quercetin and carbon nanotubes with excellent anti-oxidant activity
Multi-functional nano-hybrids based on Quercetin (Q), a natural antioxidant, and functionalized Carbon Nanotubes (CNTs) have been formulated and used to prepare Ultra High Molecular Weight PolyEthylene (UHMWPE)-based nanocomposites. The study of the nanocomposites rheological behaviour shows that the immobilization of Q molecules onto CNTs outer surface leads to a beneficial effect on the state of the interface between polymer and nanoparticles. Additionally, the investigation of the thermo- and photo- oxidation processes reveals that the hybrids nanoparticles are able to exert a remarkable stabilizing action, due to strong physical interaction between Q and CNTs. In particular, the presence of Q molecules causes the formation of CNTs structural defects, remarkably amplifying the intrinsic CNTs radical scavenging activit
Thermal stability of ammonium salts as compatibilizers in polymer/layered silicate nanocomposites
Thermal stability of alkyl and arylalkyl quaternary ammonium cation (onium) in starting chloride salt, in organoclay obtained after exchange with montmorillonite (MMT) and after mixing of the organoclay with isoprene rubber was examined using conventional TGA and by mass spectrometry pyrolysis/GC-MS. Degradation was observed to occur at T ≥ 170 °C for organoclays and the main volatile compounds were identified as tertiary amines, chloroalkanes and alkenes. Mechanisms for their formation are proposed and the role of residual onium chloride and basic centers of layered silicate is discussed
Advanced nano-hybrids for thermo-oxidative-resistant nanocomposites
In the present work, trisilanol phenyl polyhedral olygomeric silsesquiosane (TSPh-POSS) has been physically immobilized onto carbon nanotubes (CNTs) bearing covalently linked Br-terminated long-alkyl chain (Br-alkyl-f-CNTs), and the so obtained hybrid nanoparticles (Br-alkyl-f-CNTs/TSPh-POSS) have been used to prepare ultra-high molecular weight polyethylene (UHMWPE)-based nanocomposites with enhanced thermo-oxidative resistance. The effective immobilization of the TSPh-POSS molecules has been confirmed by pectroscopic and thermo-gravimetric analyses. Besides, the influence of the hybrid nanoparticles on the rheological and mechanical behaviour and morphology of the nanocomposites have been fully investigated. The obtained results show that the rheological and thermo-mechanical behaviour of UHMWPE/Br-alkyl-f- CNTs/TSPh-POSS nanocomposite is affected by two different opposite contributions: reinforcement effect of CNTs and plasticizing action induced by TSPh-POSS molecules. The unexpected excellent thermo-oxidative resistance of the nanocomposite containing hybrid nanoparticles seems to be due to a synergistic effect of TSPh-POSS and CNTs. Moreover, TSPh-POSS molecules, upon thermooxidative treatment, are able to migrate toward film surface, forming a TSPh-POSS-rich protective layer that hinders the oxygen diffusion
Immobilization of natural anti-oxidants on carbon nanotubes and aging behavior of ultra-high molecular weight polyethylene-based nanocomposites
The use of natural antioxidants is an attractive way to formulate nanocomposites with extended durability and with potential applications in bio-medical field. In this work, Vitamin E (VE) in the form of α-tocopherol and Quercetin
(Q) are physically immobilized on the outer surface of multi-walled carbon nanotubes (CNTs). Afterward, the CNTs-VE and CNTs-Q are used to formulate thermally stable ultra high molecular weight polyethylene based nanocomposites. The obtained results in the study of the thermo-oxidation behavior suggest a beneficial effect of the natural anti-oxidant carbon nanotubes systems. The unexpected excellent thermo-resistance of the nanocomposites seems to be due to a synergistic effect of the natural anti-oxidant and carbon nanotubes, i.e. strong interaction between CNT surface and antioxidant molecules. Particularly, these interactions cause the formation of structural defects onto outer CNT surfaces, which, in turn, increase the CNT radical scavenging activit
Multi-functional Polyhedral Oligomeric Silsesquioxane-functionalized Carbon Nanotubes for photo-oxidative stable Ultra-High Molecular Weight Polyethylene-based Nanocomposites
Nanohybrid (phPOSS-f-CNTs) based on Carbon Nanotubes (CNTs) and Phenyl Polyhedral Olygomenric Silsesquioxane (phPOSS) have been synthesized to be used as multifunctional filler for polymer nanocomposites. The success of the functionalization procedure has been demonstrated via accurate spectroscopic, spectrometric and thermo-gravimetric analyses. The results reveal that a large portion of phPOSS is covalently linked to CNTs, while a small amount of phPOSS remains physically adsorbed due to the strong interactions coming from π electron coupling between the CNTs and phenyl rings in phPOSS. Small amounts (1 wt.%) of phPOSS-f-CNTs have been dispersed in Ultra High Molecular Weight Polyethylene (UHMWPE), aiming at improving the photo-stability of the resulting nanocomposite. The rheological and thermo-mechanical behaviour of UHMWPE/phPOSS-f-CNTs nanocomposite reflects two different opposite contributions:, namely the reinforcement effect of CNTs and the plasticizing action of phPOSS molecules. Concerning the photo-oxidative behaviour, phPOSS-f-CNTs show a remarkable protective ability, which is absolutely much higher than those exerted by CNTs and phPOSS molecules when added one by one. Such unexpected results could be explained considering (i) a synergic effect between phPOSS and CNTs, (ii) the possibility of phPOSS to act at the polymer-nanoparticles interface, which is a critical region for the degradation processes, and (iii) the formation of a phPOSS-rich layer that may hinder the oxygen diffusion within the polymeric matrix
Thermo-oxidative resistant nanocomposites containing novel hybrid-nanoparticles based on natural polyphenol and carbon nanotubes
Quercetin (Q), a natural antioxidant molecule, is physically immobilized onto multi-walled carbon nanotubes (CNTs) bearing covalently-linked long-chain alkyl functional groups, and the so obtained hybrid-nanoparticles are used to prepare Ultra High Molecular Weight PolyEthylene-based nanocomposite films with enhanced thermo-oxidation resistance. The effective immobilization of the Q molecules is confirmed by spectroscopic (micro-Raman, ATR-FTIR, and FTIR) and thermo-gravimetric analyses, and the influence of the nanoparticles on the rheological behaviour and thermo-oxidative stability of the nanocomposites are investigated. Rheological analyses (linear viscoelasticity and stress relaxation tests) and morphological observations reveal that the Q-functionalized CNTs disperse better than bare CNTs in the host matrix. Quercetin confirms to be an excellent antioxidant for polyethylene, but the study of the thermo-oxidation behaviour shows that a remarkable stabilizing action only emerges when Q is physically immobilized on the CNTs. In particular, a ten-fold increase of the onset of degradation phenomena in thermo-oxidative environment was found. Such an excellent result is due to a synergic effect stemming from the physical interaction between Q and CNTs, which cannot provide a similar stabilizing action if used separately. In particular, we argue that the process of physical immobilization of the Q molecules causes the formation of structural defects onto outer CNTs surfaces, thus remarkably improving the CNTs radical scavenging activity and probably promoting Q regeneration. In addition, CNTs seem acting as efficient nano-carriers for the quercetin molecules, improving the dispersion of the latter in the host matrix in spite of their poor solubility