Home About us Contact
|
Home About us Contact | ||
|
|
||
Treatment Techniques (treatment + techniques)
Selected AbstractsSensitive chiral analysis by capillary electrophoresisELECTROPHORESIS, Issue 1 2006Carmen García-Ruiz Abstract In this review, an updated view of the different strategies used up to now to enhance the sensitivity of detection in chiral analysis by CE will be provided to the readers. With this aim, it will include a brief description of the fundamentals and most of the recent applications performed in sensitive chiral analysis by CE using offline and online sample treatment techniques (SPE, liquid,liquid extraction, microdialysis, etc.), on-column preconcentration techniques based on electrophoretic principles (ITP, stacking, and sweeping), and alternative detection systems (spectroscopic, spectrometric, and electrochemical) to the widely used UV-Vis absorption detection. [source] Comparison of intensity modulated radiation therapy (IMRT) treatment techniques for nasopharyngeal carcinomaINTERNATIONAL JOURNAL OF CANCER, Issue 2 2001Jason Chia-Hsien Cheng M.D. Abstract We studied target volume coverage and normal tissue sparing of serial tomotherapy intensity modulated radiation therapy (IMRT) and fixed-field IMRT for nasopharyngeal carcinoma (NPC), as compared with those of conventional beam arrangements. Twelve patients with NPC (T2-4N1-3M0) at Mallinckrodt Institute of Radiology underwent computed tomography simulation. Images were then transferred to a virtual simulation workstation computer for target contouring. Target gross tumor volumes (GTV) were primary nasopharyngeal tumor (GTVNP) with a prescription of 70 Gy, grossly enlarged cervical nodes (GTVLN) with a prescription of 70 Gy, and the uninvolved cervical lymphatics [designated as the clinical tumor volume (CTV)] with a prescription of 60 Gy. Critical organs, including the parotid gland, spinal cord, brain stem, mandible, and pituitary gland, were also delineated. Conventional beam arrangements were designed following the guidelines of Intergroup (SWOG, RTOG, ECOG) NPC Study 0099 in which the dose was prescribed to the central axis and the target volumes were aimed to receive the prescribed dose ± 10%. Similar dosimetric criteria were used to assess the target volume coverage capability of IMRT. Serial tomotherapy IMRT was planned using a 0.86-cm wide multivane collimator, while a dynamic multileaf collimator system with five equally spaced fixed gantry angles was designated for fixed-beam IMRT. The fractional volume of each critical organ that received a certain predefined threshold dose was obtained from dose-volume histograms of each organ in either the three-dimensional or IMRT treatment planning computer systems. Statistical analysis (paired t -test) was used to examine statistical significance. We found that serial tomotherapy achieved similar target volume coverage as conventional techniques (97.8 ± 2.3% vs. 98.9 ± 1.3%). The static-field IMRT technique (five equally spaced fields) was inferior, with 92.1 ± 8.6% fractional GTVNP receiving 70 Gy ± 10% dose (P < 0.05). However, GTVLN coverage of 70 Gy was significantly better with both IMRT techniques (96.1 ± 3.2%, 87.7 ± 10.6%, and 42.2 ± 21% for tomotherapy, fixed-field IMRT, and conventional therapy, respectively). CTV coverage of 60 Gy was also significantly better with the IMRT techniques. Parotid gland sparing was quantified by evaluating the fractional volume of parotid gland receiving more than 30 Gy; 66.6 ± 15%, 48.3 ± 4%, and 93 ± 10% of the parotid volume received more than 30 Gy using tomotherapy, fixed-field IMRT, and conventional therapy, respectively (P < 0.05). Fixed-field IMRT technique had the best parotid-sparing effect despite less desirable target coverage. The pituitary gland, mandible, spinal cord, and brain stem were also better spared by both IMRT techniques. These encouraging dosimetric results substantiate the theoretical advantage of inverse-planning IMRT in the management of NPC. We showed that target coverage of the primary tumor was maintained and nodal coverage was improved, as compared with conventional beam arrangements. The ability of IMRT to spare the parotid glands is exciting, and a prospective clinical study is currently underway at our institution to address the optimal parotid dose-volume needs to be spared to prevent xerostomia and to improve the quality of life in patients with NPC. © 2001 Wiley-Liss, Inc. [source] Lasers for facial rejuvenation: a reviewINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2003Evangelia Papadavid MD Background Different types of laser are used for resurfacing and collagen remodeling in cutaneous laser surgery. Methods A systematic review was performed of the different types of laser currently employed for skin rejuvenation. These systems are either ablative [high-energy pulsed or scanned carbon dioxide (CO2) laser emitting at a wavelength of 10,600 nm, single- or variable-pulse or dual ablative/coagulative mode erbium:yttrium aluminum garnet (Er:YAG) laser emitting at a wavelength of 2940 nm, or systems combining both 10,600 nm and 2940 nm wavelengths] or nonablative [Q-switched neodymium:yttrium aluminum garnet (Nd:YAG) laser emitting at a wavelength of 1064 nm, Nd:YAG laser emitting at a wavelength of 1320 nm, or diode laser emitting at a wavelength of 1450 nm]. Different protocols, patient selection, treatment techniques, and complications are discussed for each system. Results New-generation CO2 resurfacing lasers have been successful in the treatment of photodamaged skin and scarring, with a postoperative morbidity dependent on the depth of thermal damage. Because of its minimal penetration, the pulsed Er:YAG laser, usually used in the treatment of more superficial rhytides, produces less postoperative morbidity. Novel ablative systems have been developed and a further understanding of laser,tissue interaction has led to the design of nonablative systems for the treatment of rhytides, scarring, and photodamaged skin, the efficacy and profile of which remain to be evaluated in the long term. Conclusions There are several effective techniques for scar revision and the treatment of aged skin, but all have their drawbacks due to a lack of precise depth control and unwanted damage to the lower layers of the dermis. The Er:YAG laser is the treatment of choice for fine lines and superficial scars, whereas the CO2 laser is better for deeper rhytides and scars. In the future, a combination of lasers may be used for facial rejuvenation. [source] Corn and rice waste: a comparative and critical presentation of methods and current and potential uses of treated wasteINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2008Ioannis S. Arvanitoyannis Summary Although corn and rice waste can be hardly classified among the most hazardous waste, their treatment is very important in view of the great volume of waste materials involved. In this review article, an update is provided for most of the waste treatment techniques (composting, pyrolysis, gasification, combustion) used to alter the physical, chemical or biological character of the waste, to reduce its volume and/or toxicity and to make the waste safer for disposal. Furthermore, all current and potential uses of treated corn and rice waste such as fertilisers, biomass and biogas/biofuel are summarised. Four comprehensive tables and six figures provide a thorough presentation of both waste treatment methods (characteristics, advantages and disadvantages) and uses of treated corn and rice waste. [source] The effect of thermocycling and dentine pre-treatment on the durability of the bond between composite resin and dentineJOURNAL OF ORAL REHABILITATION, Issue 5 2004M. S. Huang Summary, The high bond strength between restorative resin and dentine plays an important role in long-term performance of restorations in the oral environment. A variety of treatment techniques have been described to enhance the bond strength of composite resin to dentine. Unfortunately, few studies have reported available bond durability of adhesive resins to dentine. The purpose of this research was to study the shear bond strength of composite resin to dentine pre-treated with phosphoric acid, self-etching agent or Nd:YAP laser irradiation. The durability of bond strength between resin and dentine stored in the artificial saliva thermocycling between 5 and 55 °C was also evaluated. The scanning electron microscope was used to assess the treated-dentine surfaces. The mean value of the shear bond strength in the acid-etching group (18·2 ± 4·9 MPa) was the highest among the three dentine treatments (self-etching system: 12·6 ±3·0 MPa, Nd:YAP laser: 13·4 ± 3·3 MPa) prior to thermocycling. After thermocycling, shear strength values of all treated dentines decreased with increasing number of the cycles. When subjected to 3000 thermocycles, the mean bond strengths of these pre-treated samples to composite resin became 9·1 ± 1·4, 7·8 ± 1·8, and 8·1 ± 1·7 MPa for acid-etching, self-etching and laser-irradiation, respectively, with a significant reduction of 38,50%. [source] Popliteal artery injury: Royal Perth experience and literature reviewANZ JOURNAL OF SURGERY, Issue 10 2005Mazri M. Yahya Background: Popliteal artery injury is uncommon but poses a significant challenge in Australian trauma care. Blunt trauma and knee dislocations appear to be associated with higher amputation rates. The aim of the present study was to review the authors' experience with this condition and discuss the best approach to investigation and management. Methods: The medical records of all patients with popliteal artery injury (n = 19) who were entered prospectively onto the Royal Perth Hospital Trauma Registry from 1995 to 2003 were reviewed. Their demographic data, investigations, primary operative procedures, fasciotomy, primary and secondary amputation rates and mortality were determined. Results: There were 17 male and two female patients with a median age of 34 years (range 17,62 years). Most patients (84%) were under 40 years in age. Blunt trauma was the commonest cause of popliteal artery injury (68.4%), and 84.6% of the patients had associated skeletal injury. The amputation rate in the present study was 26.3% (5/19). There were no intraoperative or in-hospital deaths. Three of 13 patients (23%) with blunt trauma underwent amputation, compared to two of six (33.3%) with penetrating injury. Two of three amputee patients in the blunt trauma group had dislocated knees. Conclusion: Despite technical improvements in management of popliteal artery injury, a high amputation rate is still seen, especially in patients with one or more of the following factors: extensive soft-issue injury, associated skeletal trauma, knee dislocation, and prolonged ischaemia time. Measures to reduce the amputation rate, ranging from more prompt diagnosis to modified surgical treatment techniques, are discussed. [source] 2255: Inflammatory neovascular membraneACTA OPHTHALMOLOGICA, Issue 2010P NERI Purpose To describe the most common mistakes in the management of inflammatory choroidal neovascularization (CNV). Methods The current literature is reviewed and the experience of a tertiary referral centre is reported. Results CNV is a potentially sight-threatening sequela of uveitis. Several mistakes can be done during patients examination: CNV might not be recognized both at biomicroscopy and at fluorescein angiography (FA), for instance. Moreover, since some doctors are not aware of the importance of Indocyanine Green Angiography (ICGA), the choroidal involvement during inflammatory CNV might not be appreciated. These are just some examples of possible errors which can be done during the daily practice. The outcome of subfoveal CNV is poor if untreated: several procedures have been considered, even though there is lack of guidelines. The most important mistake can be represented by the lack of criticism on the treatment techniques: several methods have been proposed, albeit some of them should not be used on the basis of the treatment rationale and on the better knowledge of CNV pathophysiology. The presentation shows the most typical cases where the above mentioned mistakes have been done, suggesting some methods in order to avoid them. Conclusion CNV secondary to uveitis is a severe sequela, which can lead to significant visual impairment. Several mistakes can be done during both the diagnosis and the therapeutic procedures. Although no guideline is provided, the current medical literature can give the basis for a successful treatment strategy. [source] | ||||||||||