19 research outputs found
Comparison of helical and TomoDirect techniques with simultaneous integrated boost in early breast cancer patients
Background: The aim of the study was to perform dosimetric comparisons of helical (H) and TomoDirect (TD) plans for whole-breast irradiation (WBI) with simultaneous integrated boost (SIB) in early-stage breast cancer patients undergoing breast conserving surgery.
Materials and methods: Fifty patients, 25 with left-side and 25 with right-side tumors, were determined for a treatment planning system for a total dose of 50.4Gy in 1.8Gy per fraction to WBI, with a SIB of 2.3Gy per fraction delivered to the tumor bed. The planning target volume (PTV) doses and the conformity (CI) and homogeneity indices (HI) for PTVbreast and PTVboost, as well as organ-at-risk (OAR) doses and treatment times, were compared between the H and TD plans.
Results: All plans met the PTV coverage criteria for the H plan, except for mean V107 of PTVbreast for TD plan. The H plan yielded better homogeneity and conformity of dose distribution compared to the TD plan. The ipsilateral mean lung doses were not significantly different between the two plans. The TD plans is advantageous for mean doses to the heart, contralateral breast and lung, spinal cord, and esophagus than the H plans. In both the H and TD plans, the right-sided breast patients had lower heart dose parameters than the left-sided breast patients. The TD plan is superior to the H plan in sparing the contralateral breast and lung by decreasing low-dose volumes.
Conclusions: While the OAR dose advantages of TD are appealing, shorter treatment times or improved dose homogeneity and conformity for target volume may be advantageous for H plan
Comparison of conventional and CT-based planning for intracavitary brachytherapy for cervical cancer: target volume coverage and organs at risk doses
<p>Abstract</p> <p>Background</p> <p>To compare intracavitary brachytherapy (ICBT) planning methods for cervical cancer, based on either orthogonal radiographs (conventional plan) or CT sections (CT plan); the comparison focused on target volume coverage and dose volume analysis of organs at risk (OARs), by representing point doses defined by the International Commission on Radiation Units and Measurement (ICRU) and dose volume histograms (DVHs) from 3D planning.</p> <p>Methods</p> <p>We analyzed the dosimetric data for 62 conventional and CT-based ICBT plans. The gross tumor volume (GTV), clinical target volume (CTV) and organs at risk (OAR)s were contoured on the CT-plan. Point A and ICRU 38 rectal and bladder points were defined on reconstructed CT images.</p> <p>Results</p> <p>Patients were categorized on the basis of whether the >95% isodose line of the point-A prescription dose encompassed the CTV (group 1, n = 24) or not (group 2, n = 38). The mean GTV and CTV (8.1 cc and 20.6 cc) were smaller in group 1 than in group 2 (24.7 cc and 48.4 cc) (<it>P <</it>0.001). The mean percentage of GTV and CTV coverage with the 7 Gy isodose was 93.1% and 88.2% for all patients, and decreased with increasing tumor size and stage. The mean D2 and D5 rectum doses were 1.66 and 1.42 times higher than the corresponding ICRU point doses and the mean D2 and D5 bladder doses were 1.51 and 1.28 times higher. The differences between the ICRU dose and the D2 and D5 doses were significantly higher in group 2 than in group 1 for the bladder, but not for the rectum.</p> <p>Conclusion</p> <p>The CT-plan is superior to the conventional plan in target volume coverage and appropriate evaluation of OARs, as the conventional plan overestimates tumor doses and underestimates OAR doses.</p
Türkiye’de taşra onkoloji merkezlerinde radyoterapi gören hastaların günlük katettikleri mesafenin tespiti
Radiotherapy facilities after the Turkiye-Syria earthquakes: lessons from the tragedy
[No Abstract Available
INVESTIGATION OF THE PHYSICAL PROPERTIES OF MELTBLOWN NONWOVENS FOR AIR FILTRATION
WOS: 000322802700008Textile filters are industrial textiles used in filtration applications. Among textile materials, especially nonwovens are suitable for filtration applications, because of their complex structures and appropriate thickness. Nonwoven filters are used in various application areas of technical textiles such as medtech, mobiltech, protech, packtech and hometech. Meltblown nonwovens are a unique class of materials, characterized by high surface are, porosity, softness and absorbency due to their microstructure. In this study polypropylene meltblown nonwovens were produced for the purpose of air filtration. Physical properties, namely thickness, basis weight, tensile properties, air permeability, and fibre diameter of were measured and effect of various production parameters on the physical properties of PP meltblown nonwovens were investigated and possibility for using such materials in air filtration was discussed
Bilateral Choroidal Metastases from Lung Adenocarcinoma: A Case Report
The most common malignancy of the eye is metastatic tumors, with choroidal metastases being the majority of them. In women, breast cancer is the most common cause of orbital metastases, and in men, it is lung cancer. Despite the fact that there are efficient treatment options for orbital metastases, the benefit of procedures to detect choroidal metastases is debatable due to the quick progression and poor prognosis of lung cancer. In choroidal metastases resulting from lung cancer, patients are usually presented with decreased sight. Defects in the field of vision, flashes of light and floating bodies generally follow. Treatment options of choroidal metastases include many methods including laser photocoagulation, cryotherapy, chemotherapy, radiotherapy, surgical resection, enucleation and photodynamic therapy. There are reports emphasizing radiotherapy as the most efficient treatment option. In this case report, we sum up the case of a male patient presenting with blurry vision in both eyes, who was subsequently detected to have bilateral choroidal metastatic tumor and was diagnosed with primary lung adenocarcinoma. (C) 2016 The Author(s) Published by S. Karger AG, Base
The impact of serum albumin-to-alkaline phosphatase ratio in cervical cancer patients treated with definitive chemoradiotherapy
We retrospectively analysed the prognostic significance of serum albumin, alkaline phosphatase (ALP) and albumin to ALP ratio (AAPR) and other prognostic factors affecting the overall survival (OS) and progression-free survival (PFS) in 200 cervical cancer patients treated with definitive chemoradiotherapy (CRT). The prognostic factors for OS and DFS, in addition to the predictive factors of albumin, ALP and AAPR, were investigated. Older age, lymph node metastasis, non-complete response (CR) to treatment and low serum albumin levels emerged as predictors of poor OS and PFS in multivariate analysis. However, with a cut-off value of 0.51, AAPR was not a significant prognostic factor of survival in multivariable analysis. There were no significant differences in clinicopathological factors between patients with low and high AAPR, except for lymph node metastasis, where lymph node metastasis rate was significantly higher in patients with a low AAPR compared to those with a high AAPR. Patients with CR had a significantly higher serum albumin level and AAPR compared to patients without CR. The pre-treatment serum albumin level was independent predictive for survival; therefore, it could be a suitable biomarker to guide systemic therapy and predict patient outcomes. Impact Statement What is already known on this subject? Two major determinants of tumour progression are nutritional status and inflammation. The albumin-to-alkaline phosphatase ratio (AAPR), which was originally proposed as a marker for nutritional status and immune response, was recently discovered to be a prognostic factor for various cancer types. However, its utility in the treatment of cervical cancer has not been established. What do the results of this study add? Low serum albumin levels were associated with a significantly shorter OS and PFS in cervical cancer patients treated definitively with CRT. AAPR, on the other hand, was not a significant prognostic factor for survival with a cut-off value of 0.51. Regional lymph node metastasis was significantly more common in patients with a low AAPR than in those with a high AAPR. What are the implications of these findings for clinical practice and/or further research? Patients with multiple clinicopathological risk factors and low serum albumin levels had an increased risk of disease recurrence and a poorer prognosis, highlighting the importance of additional adjuvant treatment strategies in these patients. Due to the preliminary nature of our findings, additional research is required to corroborate them
Outcome of loco-regional radiotherapy in metastatic castration-resistant prostate cancer patients treated with abiraterone acetate
Purpose To evaluate the potential benefit of curative radiotherapy (RT) to the primary tumor in metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone.
Materials and methods The clinical parameters of 106 mCRPC patients treated with abiraterone were retrospectively evaluated. Patients were either oligometastatic (<= 5 metastases) at diagnosis or became oligometastatic after the systemic treatment was analyzed. Local RT to the primary tumor and pelvic lymphatics was delivered in 44 patients (41%), and 62 patients (59%) did not have RT to the primary tumor. After propensity match analysis, a total of 92 patients were analyzed.
Resultsn Median follow-up time was 14.2 months (range: 2.3-54.9 months). Median overall survival (OS) was higher in patients treated with local RT to the primary tumor than in those treated without local RT with borderline significance (24.1 vs. 21.4 months; p=0.08). Local RT to the prostate and pelvic lymphatics significantly diminished the local recurrence rate (16 patients, 31% vs. 2 patients, 5%; p=0.003). In multivariate analysis, the prostate specific antigen (PSA) response >= 50% of the baseline obtained 3 weeks after abiraterone therapy was the only significant prognostic factor for better OS and progression-free survival (PFS). Patients treated with primary RT to the prostate had significantly less progression under abiraterone and a longer abiraterone period than those treated without local prostate RT.
Conclusions Local prostate RT significantly improved OS and local control in mCRPC patients treated with abiraterone. The patients treated with primary RT had significantly less progression under abiraterone and a longer abiraterone period than those treated without local prostate RT