927 resultados para Radiotherapy planning


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OBJECTIVE: To perform a critical review focusing on the applicability in clinical daily practice of data from three randomized controlled trials (RCTs): SWOG 8794, EORTC 22911, and ARO/AUO 96-02. METHODS AND MATERIALS: An analytical framework, based on the identified population, interventions, comparators, and outcomes (PICO) was used to refine the search of the evidence from the three large randomized trials regarding the use of radiation therapy after prostatectomy as adjuvant therapy (ART). RESULTS: With regard to the inclusion criteria: (1) POPULATION: in the time since they were designed, in two among three trial (SWOG 8794 and EORTC 22911) patients had a detectable PSA at the time of randomization, thus representing de facto a substantial proportion of patients who eventually received salvage RT (SRT) at non-normalised PSA levels rather than ART. (2) INTERVENTIONS: although all the trials showed the benefit of postoperative ART compared to a wait-and-see approach, the dose herein employed would be now considered inadequate; (3) COMPARATORS: the comparison arm in all the 3 RCTs was an uncontrolled observation arm, where patients who subsequently developed biochemical failure were treated in various ways, with up to half of them receiving SRT at PSA well above 1ng/mL, a level that would be now deemed inappropriate; (4) OUTCOMES: only in one trial (SWOG 8794) ART was found to significantly improve overall survival compared to observation, with a ten-year overall survival rate of 74% vs. 66%, although this might be partly the result of imbalanced risk factors due to competing event risk stratification. CONCLUSIONS: ART has a high level of evidence due to three RCTs with at least 10-year follow-up recording a benefit in biochemical PFS, but its penetrance in present daily clinics should be reconsidered. While the benefit of ART or SRT is eagerly expected from ongoing randomized trials, a dynamic risk-stratified approach should drive the decisions making process.

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Nursing discharge planning for elderly medical inpatients is an essential element of care to ensure optimal transition to home and to reduce post-discharge adverse events. The objectives of this cross-sectional study were to investigate the association between nursing discharge planning components in older medical inpatients, patients' readiness for hospital discharge and unplanned health care utilization during the following 30 days. Results indicated that no patients benefited from comprehensive discharge planning but most benefited from less than half of the discharge planning components. The most frequent intervention recorded was coordination, and the least common was patients' participation in decisions regarding discharge. Patients who received more nursing discharge components felt significantly less ready to go home and had significantly more readmissions during the 30-day follow-up period. This study highlights large gaps in the nursing discharge planning process in older medical inpatients and identifies specific areas where improvements are most needed.

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The government of Catalonia has developed a planning framework that seeks to establish the provision of cultural facilities throughout the country. The Cultural Facilities Plan of Catalonia (PECCAT) is based on an analysis of historical gaps and establishes a minimum spatial scheme. The plan responds to problems associated with the absence of a former similar instrument, which has led to an inconsistent and inappropriate cultural infrastructure that fails to fulfill its fundamental mission of securing the cultural rights of the population. The paper sets forth the aims of this policy and describes the objectives and basic characteristics of the plan and the expected outcomes. With the plan, the government of Catalonia seeks to rebalance the infrastructure within the territory and to ensure universal access to basic cultural services, while avoiding a logic of standardization and taking local communities into account. With the development of local plans in the municipalities, local governments encourage community participation processes to adapt and decide on priorities for action based on needs assessments and cultural opportunities for local sustainable development. The local plans focus on local cultural strengths, take advantage of opportunities, and aim to realize the cultural dynamics of a place through establishing an infrastructure that can best respond to the needs and cultural demands of the local communities, taking into account economic, social, and environmental sustainability.

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BACKGROUND AND PURPOSE: Compensation for respiratory motion is needed while administering radiotherapy (RT) to tumors that are moving with respiration to reduce the amount of irradiated normal tissues and potentially decrease radiation-induced collateral damages. The purpose of this study was to test a new ventilation system designed to induce apnea-like suppression of respiratory motion and allow long enough breath hold durations to deliver complex RT. MATERIAL AND METHODS: The High Frequency Percussive Ventilation system was initially tested in a series of 10 volunteers and found to be well tolerated, allowing a median breath hold duration of 11.6min (range 3.9-16.5min). An evaluation of this system was subsequently performed in 4 patients eligible for adjuvant breast 3D conformal RT, for lung stereotactic body RT (SBRT), lung volumetric modulated arc therapy (VMAT), and VMAT for palliative pleural metastases. RESULTS: When compared to free breathing (FB) and maximal inspiration (MI) gating, this Percussion Assisted RT (PART) offered favorable dose distribution profiles in 3 out of the 4 patients tested. PART was applied in these 3 patients with good tolerance, without breaks during the "beam on time period" throughout the overall courses of RT. The mean duration of the apnea-like breath hold that was necessary for delivering all the RT fractions was 7.61min (SD=2.3). CONCLUSIONS: This first clinical implementation of PART was found to be feasible, tolerable and offers new opportunities in the field of RT for suppressing respiratory motion.

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BACKGROUND: To compare the prognostic value of different anatomical and functional metabolic parameters determined using [(18)F]FDG-PET/CT with other clinical and pathological prognostic parameters in cervical cancer (CC). METHODS: Thirty-eight patients treated with standard curative doses of chemo-radiotherapy (CRT) underwent pre- and post-therapy [(18)F]FDG-PET/CT. [(18)F]FDG-PET/CT parameters including mean tumor standardized uptake values (SUV), metabolic tumor volume (MTV) and tumor glycolytic volume (TGV) were measured before the start of CRT. The post-treatment tumor metabolic response was evaluated. These parameters were compared to other clinical prognostic factors. Survival curves were estimated by using the Kaplan-Meier method. Cox regression analysis was performed to determine the independent contribution of each prognostic factor. RESULTS: After 37 months of median follow-up (range, 12-106), overall survival (OS) was 71 % [95 % confidence interval (CI), 54-88], disease-free survival (DFS) 61 % [95 % CI, 44-78] and loco-regional control (LRC) 76 % [95 % CI, 62-90]. In univariate analyses the [(18)F]FDG-PET/CT parameters unfavorably influencing OS, DFS and LRC were pre-treatment TGV-cutoff ≥562 (37 vs. 76 %, p = 0.01; 33 vs. 70 %, p = 0.002; and 55 vs. 83 %, p = 0.005, respectively), mean pre-treatment tumor SUV cutoff ≥5 (57 vs. 86 %, p = 0.03; 36 vs. 88 %, p = 0.004; 65 vs. 88 %, p = 0.04, respectively) and a partial tumor metabolic response after treatment (9 vs. 29 %, p = 0.0008; 0 vs. 83 %, p < 0.0001; 22 vs. 96 %, p < 0.0001, respectively). After multivariate analyses a partial tumor metabolic response after treatment remained as an independent prognostic factor unfavorably influencing DFS and LRC (RR 1:7.7, p < 0.0001, and RR 1:22.6, p = 0.0003, respectively) while the pre-treatment TGV-cutoff ≥562 negatively influenced OS and DFS (RR 1:2, p = 0.03, and RR 1:2.75, p = 0.05). CONCLUSIONS: Parameters capturing the pre-treatment glycolytic volume and metabolic activity of [(18)F]FDG-positive disease provide important prognostic information in patients with CC treated with CRT. The post-therapy [(18)F]FDG-PET/CT uptake (partial tumor metabolic response) is predictive of disease outcome.

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Abstract Objective: To determine whether low-level laser therapy can prevent salivary hypofunction after radiotherapy and chemotherapy in head and neck cancer patients. Materials and Methods: We evaluated 23 head and neck cancer patients, of whom 13 received laser therapy and 10 received clinical care only. An InGaAlP laser was used intra-orally (at 660 nm and 40 mW) at a mean dose of 10.0 J/cm2 and extra-orally (at 780 nm and 15 mW) at a mean dose of 3.7 J/cm2, three times per week, on alternate days. Stimulated and unstimulated sialometry tests were performed before the first radiotherapy and chemotherapy sessions (N0) and at 30 days after the end of treatment (N30). Results: At N30, the mean salivary flow rates were significantly higher among the laser therapy patients than among the patients who received clinical care only, in the stimulated and unstimulated sialometry tests (p = 0.0131 and p = 0.0143, respectively). Conclusion: Low-level laser therapy, administered concomitantly with radiotherapy and chemotherapy, appears to mitigate treatment-induced salivary hypofunction in patients with head and neck cancer.

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Abstract Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR) 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods: Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice.

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Coverage Path Planning (CPP) is the task of determining a path that passes over all points of an area or volume of interest while avoiding obstacles. This task is integral to many robotic applications, such as vacuum cleaning robots, painter robots, autonomous underwater vehicles creating image mosaics, demining robots, lawn mowers, automated harvesters, window cleaners and inspection of complex structures, just to name a few. A considerable body of research has addressed the CPP problem. However, no updated surveys on CPP reflecting recent advances in the field have been presented in the past ten years. In this paper, we present a review of the most successful CPP methods, focusing on the achievements made in the past decade. Furthermore, we discuss reported field applications of the described CPP methods. This work aims to become a starting point for researchers who are initiating their endeavors in CPP. Likewise, this work aims to present a comprehensive review of the recent breakthroughs in the field, providing links to the most interesting and successful works

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The aim of this Thesis is to study how to manage the front-end of the offering planning process. This includes actual process development and methods to gather and analyze information to achieve the best outcome in customer oriented product offering. Study is carried out in two parts: theoretical part and company related part. Theoretical framework is created introducing different types of approaches to manage product planning processes. Products are seen as platforms and they are broken down to subsystems to show different parts of the development. With the help of the matrix-based approaches product platform related information is gathered and analyzed. In this kind of analysis business/market drivers and cus-tomer/competitor information are connected with product subsystems. This gives possibilities to study product gaps/needs and possible future ideas/scenarios in different customer segments. Company related part consists of offering planning process development in real company environment. Process formation includes documents and tools that guide planning from the information gathering to the prioritization and decision making.