18 research outputs found
Effectiveness of Repeat Radiotherapy for Painful Bone Metastases in Clinical Practice : A 10 Year Historical Cohort Study
Aims: Repeat radiotherapy for palliation of painful bone metastases is often prescribed to non-responders or those with recurrent pain, although studies on retreatment remain scarce. We assessed the effectiveness of retreatment for painful bone metastases in terms of pain relief in everyday clinical practice and identified factors associated with response. Materials and methods: We carried out a single-institution 10 year retrospective cohort study among 247 patients retreated for painful bone metastases. Response was defined as a decrease in pain between 2 and 12 weeks after retreatment. The overall pain response rate was calculated in an evaluable-patients-only analysis and a worst-case analysis. Multivariate logistic regression analyses were used to identify factors associated with pain response. Results: A follow-up of >= 2 weeks was available in 162 of 247 patients (65%). The overall pain response was 66% (95% confidence interval 58-73%) in an evaluable-patients-only analysis and 43% (95% confidence interval 37-50%) in a worst-case analysis. Response to first irradiation (odds ratio 2.16, P = 0.049) and use of systemic therapy (odds ratio 0.39, P = 0.037) were independently associated with the response to retreatment. The median overall survival was 7.1 months. Conclusion: In everyday clinical practice, retreatment for painful bone metastases leads to pain reduction in 66% of evaluable patients and 43% of patients in a worst-case analysis. Patients who responded to initial radiotherapy were more likely to respond again and those on systemic therapy were less likely to respond. Overall, repeat radiotherapy should be considered in patients with persisting bone pain. (C) 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved
Effectiveness of Repeat Radiotherapy for Painful Bone Metastases in Clinical Practice : A 10 Year Historical Cohort Study
Aims: Repeat radiotherapy for palliation of painful bone metastases is often prescribed to non-responders or those with recurrent pain, although studies on retreatment remain scarce. We assessed the effectiveness of retreatment for painful bone metastases in terms of pain relief in everyday clinical practice and identified factors associated with response. Materials and methods: We carried out a single-institution 10 year retrospective cohort study among 247 patients retreated for painful bone metastases. Response was defined as a decrease in pain between 2 and 12 weeks after retreatment. The overall pain response rate was calculated in an evaluable-patients-only analysis and a worst-case analysis. Multivariate logistic regression analyses were used to identify factors associated with pain response. Results: A follow-up of >= 2 weeks was available in 162 of 247 patients (65%). The overall pain response was 66% (95% confidence interval 58-73%) in an evaluable-patients-only analysis and 43% (95% confidence interval 37-50%) in a worst-case analysis. Response to first irradiation (odds ratio 2.16, P = 0.049) and use of systemic therapy (odds ratio 0.39, P = 0.037) were independently associated with the response to retreatment. The median overall survival was 7.1 months. Conclusion: In everyday clinical practice, retreatment for painful bone metastases leads to pain reduction in 66% of evaluable patients and 43% of patients in a worst-case analysis. Patients who responded to initial radiotherapy were more likely to respond again and those on systemic therapy were less likely to respond. Overall, repeat radiotherapy should be considered in patients with persisting bone pain. (C) 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved
Registration of CT to pre-treatment MRI for planning of MR-HIFU ablation treatment of painful bone metastases
MR-HIFU is a new non-invasive treatment modality that can be used for palliation in patients with painful bone metastases. Since treatment strategies are mainly focused on the ablation of periosteal nerves, information on the presence and geometry of cortical bone influences the treatment strategy, both in determining the acoustic power and in avoiding safety issues related to far-field heating. Although MRI is available for imaging during treatment, CT is best used for examining the cortical bone. We present a registration method for registering CT and MR images of patients with bone metastases prior to therapy. CT and MRI data were obtained from nine patients with metastatic bone lesions at varying locations. A two-step registration approach was used, performing simultaneous rigid registration of all available MR images in the first step and an affine and deformable registration with an additional bone metric in the second step. The performance was evaluated using landmark annotation by clinical observers. An average registration error of 4.5 mm was obtained, which was comparable to the slice thickness of the data. The performance of the registration algorithm was satisfactory, even with differences in MRI acquisition parameters and for various anatomical sites. The obtained CT overlay is useful for treatment planning, as it allows an assessment of the integrity of the cortical bone. CT-MR registration is therefore recommended for HIFU treatment planning of patients with bone metastases
Prothrombotic coagulation defects and cardiovascular risk factors in young women with acute myocardial infarction
We investigated the effect of prothrombotic coagulation defects in combination with smoking and other conventional risk factors on the risk of myocardial infarction in young women. In 217 women with a first myocardial infarction before the age of 50 years and 763 healthy control women from a population-based case-control study, factor V Leiden and prothrombin 20210A status were determined. Data on major cardiovascular risk factors and oral contraceptive use were combined with the presence or absence of these prothrombotic mutations, and compared between patients and controls. The overall odds ratio for myocardial infarction in the presence of a coagulation defect was 1.1 [95% confidence interval (CI) 0.6-1.9]. The combination of a prothrombotic mutation and current smoking increased the risk of myocardial infarction 12-fold (95% CI 5.7-27) compared with non-smokers without a coagulation defect. Among women who smoked cigarettes, factor V Leiden presence versus absence increased the risk of myocardial infarction by 2.0 (95% CI 0.9-4.6), and prothrombin 20210A presence versus absence had an odds ratio of 1.0 (95% CI 0.3-3.5). We conclude that factor V Leiden and prothrombin 20210A do not add substantially to the overall risk of myocardial infarction in young women. However, in women who smoke, the presence of factor V Leiden increased the risk of myocardial infarction twofold
Simultaneous R2 *, R2 , and R2 ' quantification by combining S0 estimation of the free induction decay with a single spin echo : A single acquisition method for R2 insensitive quantification of holmium-166-loaded microspheres
PURPOSE: To present a new method, S0 estimation of the free induction decay combined with a single spin echo measurement (SOFIDSE), that enables simultaneous measurements of R2 *, R2 , and R2 ' in order to quantify the local concentration of holmium microspheres (Ho-MS) for radioembolization. THEORY AND METHODS: SOFIDSE estimates R2 * and the signal magnitude at time point 0, S0 , from a multigradient echo readout of the free induction decay and subsequently estimates R2 using S0 and a single spin echo, from which R2 ' is deducted. The method was evaluated by comparing SOFIDSE R2 values with values obtained from shifted spin echo (SSE) measurements on a phantom setup containing Ho-MS and from dual spin echo measurements on a healthy volunteer. RESULTS: On average, SOFIDSE showed a small overestimation of R2 values compared with SSE independent of the microsphere concentration. R2 ' values determined by subtraction of either SOFIDSE R2 or SSE R2 from R2 * showed excellent agreement (correlation coefficient = 1; P = 9 · 10(-11) ). The Ho-MS-induced R2 ' values obtained by SOFIDSE were insensitive to the R2 value of the tissue in which they resided. CONCLUSION: SOFIDSE enables quantification of Ho-MS, in media with spatially or temporally varying R2 values, in a single acquisition. Magn Reson Med 73:273-283, 2015. © 2014 Wiley Periodicals, Inc
Simultaneous R2 *, R2 , and R2 ' quantification by combining S0 estimation of the free induction decay with a single spin echo : A single acquisition method for R2 insensitive quantification of holmium-166-loaded microspheres
PURPOSE: To present a new method, S0 estimation of the free induction decay combined with a single spin echo measurement (SOFIDSE), that enables simultaneous measurements of R2 *, R2 , and R2 ' in order to quantify the local concentration of holmium microspheres (Ho-MS) for radioembolization. THEORY AND METHODS: SOFIDSE estimates R2 * and the signal magnitude at time point 0, S0 , from a multigradient echo readout of the free induction decay and subsequently estimates R2 using S0 and a single spin echo, from which R2 ' is deducted. The method was evaluated by comparing SOFIDSE R2 values with values obtained from shifted spin echo (SSE) measurements on a phantom setup containing Ho-MS and from dual spin echo measurements on a healthy volunteer. RESULTS: On average, SOFIDSE showed a small overestimation of R2 values compared with SSE independent of the microsphere concentration. R2 ' values determined by subtraction of either SOFIDSE R2 or SSE R2 from R2 * showed excellent agreement (correlation coefficient = 1; P = 9 · 10(-11) ). The Ho-MS-induced R2 ' values obtained by SOFIDSE were insensitive to the R2 value of the tissue in which they resided. CONCLUSION: SOFIDSE enables quantification of Ho-MS, in media with spatially or temporally varying R2 values, in a single acquisition. Magn Reson Med 73:273-283, 2015. © 2014 Wiley Periodicals, Inc
Arterial and portal venous liver perfusion using selective spin labelling MRI
Purpose\u3cbr/\u3eTo investigate the feasibility of selective arterial and portal venous liver perfusion imaging with spin labelling (SL) MRI, allowing separate labelling of each blood supply.\u3cbr/\u3e\u3cbr/\u3eMethods\u3cbr/\u3eThe portal venous perfusion was assessed with a pulsed EPISTAR technique and the arterial perfusion with a pseudo-continuous sequence. To explore precision and reproducibility, portal venous and arterial perfusion were separately quantified in 12 healthy volunteers pre- and postprandially (before and after meal intake). In a subgroup of 6 volunteers, the accuracy of the absolute portal perfusion and its relative postprandial change were compared with MRI flow measurements of the portal vein.\u3cbr/\u3e\u3cbr/\u3eResults\u3cbr/\u3eThe portal venous perfusion significantly increased from 63 ± 22 ml/100g/min preprandially to 132 ± 42 ml/100g/min postprandially. The arterial perfusion was lower with 35 ± 22 preprandially and 22 ± 30 ml/100g/min postprandially. The pre- and postprandial portal perfusion using SL correlated well with flow-based perfusion (r2 = 0.71). Moreover, postprandial perfusion change correlated well between SL- and flow-based quantification (r2 = 0.77). The SL results are in range with literature values.\u3cbr/\u3e\u3cbr/\u3eConclusion\u3cbr/\u3eSelective spin labelling MRI of the portal venous and arterial blood supply successfully quantified liver perfusion. This non-invasive technique provides specific arterial and portal venous perfusion imaging and could benefit clinical settings where contrast agents are contraindicated.\u3cbr/\u3