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Lehman M.,Southern Zone Radiation Oncology | Hickey B.,Materials Center
Breast | Year: 2010

The addition of conventional whole breast irradiation (WBI) to breast conserving surgery (BCS) reduces the risk of early breast cancer recurrence and leads to a statistically and clinically significant improvement in overall survival. However, the long duration of conventional WBI regimens negatively impacts on quality of life. This has led investigators to evaluate an alternative approach of delivering radiation to a limited volume of tissue around the tumour cavity only (partial breast irradiation) and delivering a larger than standard dose of radiation with each treatment (accelerated partial breast irradiation, APBI). This approach may be achieved by a number of techniques: interstitial brachytherapy, intracavitary brachytherapy using the Mammosite device, intraoperative techniques using electrons or low-energy photons, external beam radiotherapy or permanent seed implant. This articles will review the rationale for the less that whole breast radiotherapy approach and describe the techniques by which it can be achieved and the results obtained to date. Finally, the 7 prospective randomised controlled trials of conventional WBI versus APBI which are open and currently recruiting patients will be discussed. © 2010 Elsevier Ltd. Source


Foroudi F.,Peter MacCallum Cancer Institute | Foroudi F.,University of Melbourne | Pham D.,Peter MacCallum Cancer Institute | Rolfo A.,Peter MacCallum Cancer Institute | And 13 more authors.
Radiotherapy and Oncology | Year: 2014

Purpose To assess whether online adaptive radiotherapy for bladder cancer is feasible across multiple Radiation Oncology departments using different imaging, delivery and recording technology. Materials and methods A multi-centre feasibility study of online adaptive radiotherapy, using a choice of three "plan of the day", was conducted at 12 departments. Patients with muscle-invasive bladder cancer were included. Departments were activated if part of the pilot study or after a site-credentialing visit. There was real time review of the first two cases from each department. Results 54 patients were recruited, with 50 proceeding to radiotherapy. There were 43 males and 7 females with a mean age of 78 years. The tumour stages treated included T1 (1 patient), T2 (35), T3 (10) and T4 (4). One patient died of an unrelated cause during radiotherapy. The three adaptive plans were created before the 10th fraction in all cases. In 8 (16%) of the patients, a conventional plan using a 'standard' CTV to PTV margin of 1.5 cm was used for one or more fractions where the pre-treatment bladder CTV was larger than any of the three adaptive plans. The bladder CTV extended beyond the PTV on post treatment imaging in 9 (18%) of the 49 patients. Conclusions From a technical perspective an online adaptive radiotherapy technique can be instituted in a multi-centre setting. However, without further bladder filling control or imaging, a CTV to PTV margin of 7 mm is insufficient. © © 2014 Elsevier Ireland Ltd. All rights reserved. Source


News Article
Site: http://phys.org/chemistry-news/

A method of fabricating polymer membranes with nanometer-scale holes that overcomes some practical challenges has been demonstrated by KAUST researchers. Porous membranes can filter pollutants from a liquid, and the smaller the holes, the finer the particles the membrane can remove. The KAUST team developed a block copolymer membrane with pores as small as 1.5 nanometers but with increased water flux, the volume processed per hour by a membrane of a certain area. A nanofilter needs to be efficient at rejecting specific molecules, be producible on a large scale, filter liquid quickly and be resistant to fouling or the build-up of removed micropollutants on the surface. Block copolymers have emerged as a viable material for this application. Their characteristics allow them to self-assemble into regular patterns that enable the creation of nanoporous materials with pores as small as 10 nanometers. However, reducing the size further to three nanometers has only been possible by post-treating the membrane (depositing gold, for example). Moreover, smaller holes usually reduce the water flux. Klaus-Viktor Peinemann from the KAUST Advanced Membranes & Porous Materials Center and Suzana Nunes from the KAUST Biological and Environmental Science and Engineering Division formed a multidisciplinary team to find a solution. "We mixed two block copolymers in a casting solution, tuning the process by choosing the right copolymer systems, solvents, casting conditions," explained Haizhou Yu, a postdoctoral fellow in Peinemann's group. This approach is an improvement on alternatives because it doesn't require material post-treatment. Peinemann and colleagues blended polystyrene-b-poly(acrylic acid) and polystyrene-b-poly(4-vinylpyridine) in a ratio of six to one. This created a sponge-like layer with a 60 nanometer film on top. Material analysis showed that nanoscale pores formed spontaneously without the need for direct patterning. The researchers used their nanofiltration material to filter the biological molecule protoporphyrin IX from water. The filter simultaneously allowed another molecule, lysine, to pass through, demonstrating its molecular selectivity. The researchers were able to filter 540 liters per hour for every square meter of membrane, which is approximately 10 times faster than commercial nanofiltration membranes. The groups teamed up with Victor Calo from the University's Physical Science and Engineering Division to develop computer models to understand the mechanism of pore formation. They showed that the simultaneous decrease in pore size and increase in flux was possible because, while the pores are smaller, the pore density in the block copolymer is higher. "In the future, we hope to optimize membranes for protein separation and other applications by changing the copolymer composition, synthesizing new polymers and mixing with additives," said Nunes. Explore further: A nano-Solution to global water problem: Nanomembranes could filter bacteria More information: Haizhou Yu et al. Self-Assembled Asymmetric Block Copolymer Membranes: Bridging the Gap from Ultra- to Nanofiltration, Angewandte Chemie International Edition (2015). DOI: 10.1002/anie.201505663


Home > Press > Faster, finer filtration: The right blend of polymers enables rapid and molecule-selective filtering of tiny particles from water Abstract: A method of fabricating polymer membranes with nanometer-scale holes that overcomes some practical challenges has been demonstrated by KAUST researchers. Porous membranes can filter pollutants from a liquid, and the smaller the holes, the finer the particles the membrane can remove. The KAUST team developed a block copolymer membrane with pores as small as 1.5 nanometers but with increased water flux, the volume processed per hour by a membrane of a certain area. A nanofilter needs to be efficient at rejecting specific molecules, be producible on a large scale, filter liquid quickly and be resistant to fouling or the build-up of removed micropollutants on the surface. Block copolymers have emerged as a viable material for this application. Their characteristics allow them to self-assemble into regular patterns that enable the creation of nanoporous materials with pores as small as 10 nanometers. However, reducing the size further to three nanometers has only been possible by post-treating the membrane (depositing gold, for example2). Moreover, smaller holes usually reduce the water flux. Klaus-Viktor Peinemann from the KAUST Advanced Membranes & Porous Materials Center and Suzana Nunes from the KAUST Biological and Environmental Science and Engineering Division formed a multidisciplinary team to find a solution. "We mixed two block copolymers in a casting solution, tuning the process by choosing the right copolymer systems, solvents, casting conditions," explained Haizhou Yu, a postdoctoral fellow in Peinemann's group. This approach is an improvement on alternatives because it doesn't require material post-treatment. Peinemann and colleagues blended polystyrene-b-poly(acrylic acid) and polystyrene-b-poly(4-vinylpyridine) in a ratio of six to one. This created a sponge-like layer with a 60 nanometer film on top. Material analysis showed that nanoscale pores formed spontaneously without the need for direct patterning1. The researchers used their nanofiltration material to filter the biological molecule protoporphyrin IX from water. The filter simultaneously allowed another molecule, lysine, to pass through, demonstrating its molecular selectivity. The researchers were able to filter 540 liters per hour for every square meter of membrane, which is approximately 10 times faster than commercial nanofiltration membranes. The groups teamed up with Victor Calo from the University's Physical Science and Engineering Division to develop computer models to understand the mechanism of pore formation. They showed that the simultaneous decrease in pore size and increase in flux was possible because, while the pores are smaller, the pore density in the block copolymer is higher. "In the future, we hope to optimize membranes for protein separation and other applications by changing the copolymer composition, synthesizing new polymers and mixing with additives," said Nunes. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


Morgan G.W.,Northern Sydney Cancer Center | Barton M.,University of New South Wales | Atkinson C.,Christchurch Hospital | Millar J.,Radiation Oncology | And 2 more authors.
Journal of Medical Imaging and Radiation Oncology | Year: 2010

Aim: In this study we estimated (a) the number of linear accelerators required in Australia and New Zealand to achieve a 52.3% treatment rate; (b) the 'GAP' between the actual and required number of linear accelerators; c) the number of persons not treated (PNT), premature deaths (PD) and years of life lost (YLL) as a result of the 'GAP'; and (d) to review the actions being taken by health jurisdictions in Australia and in New Zealand to address the 'GAP' and reach the 52.3% treatment rate. Material and Methods: The actual number of fully staffed and operating linear accelerators (A) in Australian and New Zealand was obtained from a survey of radiotherapy facilities in December 2009. The required number of linear accelerators (R) was calculated from the projected cancer incidence figures for 2009 and was based on 1.6 linear accelerators being required per 1000 new cancer patients. The 'GAP' in Radiotherapy services (G) was R minus A. The maximum treatment capacity (MTC) was the ratio of A over R multiplied by 52.3%, assuming that all linear accelerators were operating at 100% capacity. As each linear accelerator can treat 331 new patients each year, the number of new cancer PNT is G × 331. The estimated 5-year survival benefit from radiotherapy is 16%, and the average survival for all patients receiving radiotherapy (radical and palliative) is 0.76 year. Hence, the number of PD attributed to the 'GAP' is PNT × 16%, and the YLL to cancer is PNT × 0.76. A literature search and local knowledge of health department Radiotherapy Plans in all jurisdictions were used to determine the action being taken to achieve a 52.3% treatment rate. Results: In 2009, the 'GAP' was 50 linear accelerators in Australia and the MTC was 38%, the same as it was in 1999, but there has been an increase in PNT each year from 7419 in 1999 to 16 550 in 2009, and PD each year increased from 1187 in 1999 to 2649 in 2009, and YLL each year increased from 5638 in 1999 to 12 585 in 2009. In New Zealand in 2009, the 'GAP' was nine linear accelerators and the MTC was 38%. An estimated 3310 persons did not receive radiotherapy in 2009 in New Zealand, and as a result, there were 523 PD and 2266 YLL. The review showed that new and replacement machines were being installed in all jurisdictions in Australia and in New Zealand. Only Victoria and Queensland have a Radiotherapy Plan beyond 2010, but both have underestimated the projected cancer incidence. Conclusion: Urgent action is needed by health departments and governments on both sides of the Tasman to improve access and equity to this essential cancer treatment. There is merit in the Baume Report recommendation of establishing a national body to oversee radiotherapy services in all jurisdictions in Australia. A similar central body should also be considered for New Zealand. © 2010 The Royal Australian and New Zealand College of Radiologists. Source

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