Radiation Attenuation

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M.i. Sayyed - One of the best experts on this subject based on the ideXlab platform.

  • Radiation Attenuation properties of bioactive glasses doped with NiO
    Ceramics International, 2020
    Co-Authors: Imed Boukhris, Amani Alalawi, M.s. Al-buriahi, Imen Kebaili, M.i. Sayyed
    Abstract:

    Abstract This paper focuses on the evaluation of the Radiation Attenuation properties of 15CaF2-10CaO-5B2O3-(65-x)P2O5-xNiO-5BaO (where 0 ≤ x ≤ 1.0 mol%) bioactive glasses. The Radiation Attenuation features of these glasses were investigated by determining different factors including mass Attenuation coefficient (μ/ρ), exposure and absorption buildup factors (EBF and EABF), neutron removal cross section (NRCS), and effective atomic number (Zeff) for photon, proton, and carbon ion interactions. Geant4 toolkit and Phy-X program were employed for simulations and calculations procedures. The results revealed that NiO content in the studied bioactive glasses has a significant effect on photon interaction and an insignificant effect on the charged particle interactions. The Zeff values of the studied glasses were observed in the range of 18–20 for photon interaction, 10.7–10.9 for proton interaction, and 10.0–10.7 for carbon ion interaction. The NRCS values were 0.087, 0.088, 0.089, 0.090, and 0.091 cm-1 for x = 0, 0.4, 0.6, 0.8 and 1.0 mol%, respectively. The studied bioactive glasses showed a good ability to attenuate gamma Radiation at energies of medical applications.

  • study on the Radiation Attenuation properties of locally available bees wax as a tissue equivalent bolus material in radiotherapy
    Radiation Physics and Chemistry, 2020
    Co-Authors: Sazirul Islam, M.i. Sayyed, K A Mahmoud, Bunyamin Alim, Mizanur Rahman, A S Mollah
    Abstract:

    Abstract In Radiation therapy field, bolus material is frequently utilized when treating different areas of a patient, like at the ears or nose, and to provide build-up of dose to the skin surface. The bolus material must be cost effective, suitably flexible to conform to the surface of the patient, and most importantly should be tissue equivalent. The main objective of this work was to estimate the photon Attenuation properties of locally available bees-wax and to assess the feasibility of using this bees-wax as a bolus material practice for treatment of cancer patient. The mass Attenuation coefficient (μ/ρ) values have been calculated by using MCNP5 simulation code over the wide range of photon energy (0.015–10 MeV). Some related parameters such as the effective atomic number and the mean free path were also calculated to understand the photon Attenuation ability of the investigated bolus material. The Attenuation properties were also computed for water, tissue and commercial bolus materials for comparison. Evaluation of the results showed that the Radiation Attenuation properties of locally available bees-wax have a good similarity to water/tissue. Referring to the results of this study, it is proposed that locally available bees-wax is a suitable substance to be used as bolus material practice for treat of cancer patient.

  • Radiation Attenuation properties of bi2o3 na2o v2o5 tio2 teo2 glass system using phy x psd software
    Ceramics International, 2020
    Co-Authors: Y Alhadeethi, M.i. Sayyed
    Abstract:

    Abstract The purpose of this work is to investigate the effect of increasing Bi2O3 mol% on the Radiation shielding parameters of tellurite glass system with the formula Bi2O3–Na2O– V2O5– TiO2–TeO2 by using Phy-X/PSD computer software between 15 keV and 10 MeV. The results showed that the Attenuation factor is very large at 15 keV. The mass Attenuation coefficient (μ/ρ) at 15 keV lies within the range of 55.96–67.03 cm2/g for the selected samples. The μ/ρ for the investigated samples at 10 MeV is in the range of 0.0365–0.0392 cm2/g. The results also revealed that the addition of Bi2O3 enhances the effective atomic number (Zeff) and the sample corresponding to the lowest and highest amount of Bi2O3 (coded as TeBTi1 and TeBTi6) has the lowest and highest Zeff. Moreover, Zeff has high values between 15 keV and 0.1 MeV and the maximum Zeff occurs at 0.1 MeV (equal to 61.01, 62.67, 64.10, 65.34, 66.44 and 67.41 for TeBTi1– TeBTi6 samples respectively). The half value layer (HVL) increased when the energy changes from 15 keV to 10 MeV and the lowest HVL occurs at 15 keV for the sample coded as TeBTi6 and equal to 0.0025 cm, while the HVL at this energy for TeBTi1 is 0.0056 cm. Also, we calculated the tenth value layer (TVL) for the present system and we found that TVL reduces with the increment of Bi2O3 content, and the sample corresponding to 22 and 0 mol% of Bi2O3 and TiO2 respectively namely TeBTi6 possesses the lowest value of TVL, thus has the best Radiation Attenuation performance in comparison to other selected glasses. Also, we evaluated the effective removal cross-sections of fast neutrons (∑R) for the investigated glass system and we found that the ∑R values increase with increase the concentration of Bi2O3.

  • Radiation Attenuation properties of Bi2O3–Na2O– V2O5– TiO2–TeO2 glass system using Phy-X / PSD software
    Ceramics International, 2020
    Co-Authors: Yas Al-hadeethi, M.i. Sayyed
    Abstract:

    Abstract The purpose of this work is to investigate the effect of increasing Bi2O3 mol% on the Radiation shielding parameters of tellurite glass system with the formula Bi2O3–Na2O– V2O5– TiO2–TeO2 by using Phy-X/PSD computer software between 15 keV and 10 MeV. The results showed that the Attenuation factor is very large at 15 keV. The mass Attenuation coefficient (μ/ρ) at 15 keV lies within the range of 55.96–67.03 cm2/g for the selected samples. The μ/ρ for the investigated samples at 10 MeV is in the range of 0.0365–0.0392 cm2/g. The results also revealed that the addition of Bi2O3 enhances the effective atomic number (Zeff) and the sample corresponding to the lowest and highest amount of Bi2O3 (coded as TeBTi1 and TeBTi6) has the lowest and highest Zeff. Moreover, Zeff has high values between 15 keV and 0.1 MeV and the maximum Zeff occurs at 0.1 MeV (equal to 61.01, 62.67, 64.10, 65.34, 66.44 and 67.41 for TeBTi1– TeBTi6 samples respectively). The half value layer (HVL) increased when the energy changes from 15 keV to 10 MeV and the lowest HVL occurs at 15 keV for the sample coded as TeBTi6 and equal to 0.0025 cm, while the HVL at this energy for TeBTi1 is 0.0056 cm. Also, we calculated the tenth value layer (TVL) for the present system and we found that TVL reduces with the increment of Bi2O3 content, and the sample corresponding to 22 and 0 mol% of Bi2O3 and TiO2 respectively namely TeBTi6 possesses the lowest value of TVL, thus has the best Radiation Attenuation performance in comparison to other selected glasses. Also, we evaluated the effective removal cross-sections of fast neutrons (∑R) for the investigated glass system and we found that the ∑R values increase with increase the concentration of Bi2O3.

  • the influence of pbo on the Radiation Attenuation features of tellurite glass
    Ceramics International, 2019
    Co-Authors: Y Alhadeethi, M.i. Sayyed
    Abstract:

    Abstract Tellurite based glasses have been of considerable interest in the last decades due to their interesting mechanical, physical and chemical features. Presently, different investigators and engineers are being devoted for developing the Tellurite based glasses to be used as effective Radiation shielding materials. Our aim is to study the energy as well as PbO content dependence on the gamma rays Attenuation behavior of lead tellurite glasses when the PbO content changes from 0 to 30 mol% between 0.356 and 2.506 MeV photon energies. This was achieved by considering the lead tellurite glass system with the composition x(PbO)-(100-x)(TeO2). The photon Attenuation factors of the lead tellurite glasses were evaluated at five energies utilizing Monte Carlo simulation (Geant4 code). The reative difference values between Geant4 and XCOM data for the six glasses are less than 7% and this validates the accuracy of the obtained results. The mass Attenuation coefficient (μ/ρ) reduces with an increase in the energy whereas it increases when TeO2 is replaced by PbO. The influence of PbO on the μ/ρ is significant only at 0.356 and 0.511 MeV, but at the other energies it is found that PbO slightly affects the Attenuation factor. The linear Attenuation coefficient of 30PbO–70TeO2 (coded as TePb6) is higher than the other samples. The effective atomic number has the maximum value at 0.356 MeV (in the range of 27.76–41.25). We compared the mean free path for the tellurite glasses with RS-520 and RS-360, Osmani, nasir and PHP glasses. The results reveal that the lead tellurite glasses (especially the samples with high PbO content) are a candidate as protection materials from hazardous Radiation and have better Attenuation in comparison to some nuclear engineering materials.

Y Alhadeethi - One of the best experts on this subject based on the ideXlab platform.

  • Radiation Attenuation properties of bi2o3 na2o v2o5 tio2 teo2 glass system using phy x psd software
    Ceramics International, 2020
    Co-Authors: Y Alhadeethi, M.i. Sayyed
    Abstract:

    Abstract The purpose of this work is to investigate the effect of increasing Bi2O3 mol% on the Radiation shielding parameters of tellurite glass system with the formula Bi2O3–Na2O– V2O5– TiO2–TeO2 by using Phy-X/PSD computer software between 15 keV and 10 MeV. The results showed that the Attenuation factor is very large at 15 keV. The mass Attenuation coefficient (μ/ρ) at 15 keV lies within the range of 55.96–67.03 cm2/g for the selected samples. The μ/ρ for the investigated samples at 10 MeV is in the range of 0.0365–0.0392 cm2/g. The results also revealed that the addition of Bi2O3 enhances the effective atomic number (Zeff) and the sample corresponding to the lowest and highest amount of Bi2O3 (coded as TeBTi1 and TeBTi6) has the lowest and highest Zeff. Moreover, Zeff has high values between 15 keV and 0.1 MeV and the maximum Zeff occurs at 0.1 MeV (equal to 61.01, 62.67, 64.10, 65.34, 66.44 and 67.41 for TeBTi1– TeBTi6 samples respectively). The half value layer (HVL) increased when the energy changes from 15 keV to 10 MeV and the lowest HVL occurs at 15 keV for the sample coded as TeBTi6 and equal to 0.0025 cm, while the HVL at this energy for TeBTi1 is 0.0056 cm. Also, we calculated the tenth value layer (TVL) for the present system and we found that TVL reduces with the increment of Bi2O3 content, and the sample corresponding to 22 and 0 mol% of Bi2O3 and TiO2 respectively namely TeBTi6 possesses the lowest value of TVL, thus has the best Radiation Attenuation performance in comparison to other selected glasses. Also, we evaluated the effective removal cross-sections of fast neutrons (∑R) for the investigated glass system and we found that the ∑R values increase with increase the concentration of Bi2O3.

  • the influence of pbo on the Radiation Attenuation features of tellurite glass
    Ceramics International, 2019
    Co-Authors: Y Alhadeethi, M.i. Sayyed
    Abstract:

    Abstract Tellurite based glasses have been of considerable interest in the last decades due to their interesting mechanical, physical and chemical features. Presently, different investigators and engineers are being devoted for developing the Tellurite based glasses to be used as effective Radiation shielding materials. Our aim is to study the energy as well as PbO content dependence on the gamma rays Attenuation behavior of lead tellurite glasses when the PbO content changes from 0 to 30 mol% between 0.356 and 2.506 MeV photon energies. This was achieved by considering the lead tellurite glass system with the composition x(PbO)-(100-x)(TeO2). The photon Attenuation factors of the lead tellurite glasses were evaluated at five energies utilizing Monte Carlo simulation (Geant4 code). The reative difference values between Geant4 and XCOM data for the six glasses are less than 7% and this validates the accuracy of the obtained results. The mass Attenuation coefficient (μ/ρ) reduces with an increase in the energy whereas it increases when TeO2 is replaced by PbO. The influence of PbO on the μ/ρ is significant only at 0.356 and 0.511 MeV, but at the other energies it is found that PbO slightly affects the Attenuation factor. The linear Attenuation coefficient of 30PbO–70TeO2 (coded as TePb6) is higher than the other samples. The effective atomic number has the maximum value at 0.356 MeV (in the range of 27.76–41.25). We compared the mean free path for the tellurite glasses with RS-520 and RS-360, Osmani, nasir and PHP glasses. The results reveal that the lead tellurite glasses (especially the samples with high PbO content) are a candidate as protection materials from hazardous Radiation and have better Attenuation in comparison to some nuclear engineering materials.

Cornelis H C Dejong - One of the best experts on this subject based on the ideXlab platform.

  • Low thoracic muscle Radiation Attenuation is associated with postoperative pneumonia following partial hepatectomy for colorectal metastasis.
    Hpb, 2019
    Co-Authors: Gregory Van Der Kroft, David P J Van Dijk, Sander S Rensen, Cornelis H C Dejong, Frank H. Van Tiel, Bianca T. A. De Greef, Malcolm A. West, Kristoffer Ostridge, Ulf P. Neumann, Steven W.m. Olde Damink
    Abstract:

    Abstract Background Low skeletal muscle Radiation Attenuation (SM-RA) is indicative of myosteatosis and diminished muscle function. It is predictive of poor outcome following oncological surgery in several cancer types. Postoperative pneumonia is a known risk factor for increased postoperative mortality. We hypothesized that low SM-RA of the respiratory muscles at the 4th thoracic-vertebra (T4) is associated with postoperative pneumonia following liver surgery. Methods Postoperative pneumonia was identified using prospective infection control data. Computed tomography body composition analysis was performed at the L3-and T4 level to determine SM-RA. Body composition variables were corrected for confounders and related to postoperative pneumonia and admission time by multivariable logistic regression. Results Body composition analysis of 180 patients was performed. Twenty-one patients developed postoperative pneumonia (11.6%). Multivariable analysis showed that low T4 SM-RA as well as low L3 SM-RA were significantly associated with postoperative pneumonia (OR 3.65, 95% CI 1.41–9.49, p  Conclusion Low SM-RA at either the L3-or T4-level is associated with a higher risk of postoperative pneumonia following CLRM resection.

  • Myosteatosis predicts survival after surgery for periampullary cancer: a novel method using MRI.
    Hpb, 2018
    Co-Authors: David P J Van Dijk, Sander S Rensen, Cornelis H C Dejong, Frans C. H. Bakers, Sebastian Sanduleanu, Rianne D. W. Vaes, Regina G. H. Beets-tan, Steven W.m. Olde Damink
    Abstract:

    Abstract Background Myosteatosis, characterized by inter- and intramyocellular fat deposition, is strongly related to poor overall survival after surgery for periampullary cancer. It is commonly assessed by calculating the muscle Radiation Attenuation on computed tomography (CT) scans. However, since magnetic resonance imaging (MRI) is replacing CT in routine diagnostic work-up, developing methods based on MRI is important. We developed a new method using MRI-muscle signal intensity to assess myosteatosis and compared it with CT-muscle Radiation Attenuation. Methods Patients were selected from a prospective cohort of 236 surgical patients with periampullary cancer. The MRI-muscle signal intensity and CT-muscle Radiation Attenuation were assessed at the level of the third lumbar vertebra and related to survival. Results Forty-seven patients were included in the study. Inter-observer variability for MRI assessment was low (R2 = 0.94). MRI-muscle signal intensity was associated with short survival: median survival 9.8 (95%-CI: 1.5–18.1) vs. 18.2 (95%-CI: 10.7–25.8) months for high vs. low intensity, respectively (p = 0.038). Similar results were found for CT-muscle Radiation Attenuation (low vs. high Radiation Attenuation: 10.8 (95%-CI: 8.5–13.1) vs. 15.9 (95%-CI: 10.2–21.7) months, respectively; p = 0.046). MRI-signal intensity correlated negatively with CT-Radiation Attenuation (r=−0.614, p  Conclusions Myosteatosis may be adequately assessed using either MRI-muscle signal intensity or CT-muscle Radiation Attenuation.

  • low skeletal muscle Radiation Attenuation and visceral adiposity are associated with overall survival and surgical site infections in patients with pancreatic cancer
    Journal of Cachexia Sarcopenia and Muscle, 2017
    Co-Authors: David P J Van Dijk, Maikel Bakens, Marielle M E Coolsen, Sander S Rensen, Martijn J L Bours, Matty P Weijenberg, Cornelis H C Dejong
    Abstract:

    Background Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in relation to survival, post-operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas. Methods A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle Radiation Attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex-specific cut-offs were determined at the lower tertile for muscle Radiation Attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post-operative complications (Dindo–Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox-regression analysis and multivariable logistic regression analysis, respectively. Results Low muscle Radiation Attenuation was associated with shorter survival in comparison with moderate and high muscle Radiation Attenuation [median survival 10.8 (95% CI: 8.8–12.8) vs. 17.4 (95% CI: 14.7–20.1), and 18.5 (95% CI: 9.2–27.8) months, respectively; P < 0.008]. Patient subgroups with high muscle Radiation Attenuation combined with either low visceral adipose tissue or age <70 years had longer survival than other subgroups (P = 0.011 and P = 0.001, respectively). Muscle Radiation Attenuation was inversely correlated with intermuscular adipose tissue (rp = −0.697, P < 0.001). High visceral adipose tissue was associated with an increased surgical site infection rate, OR: 2.4 (95% CI: 1.1–5.3; P = 0.027). Conclusions Low muscle Radiation Attenuation was associated with reduced survival, and high visceral adiposity was associated with an increase in surgical site infections. The strong correlation between muscle Radiation Attenuation and intermuscular adipose tissue suggests the presence of ectopic fat in muscle, warranting further investigation. CT image analysis could be implemented in pre-operative risk assessment to assist in treatment decision-making.

  • Low skeletal muscle Radiation Attenuation and visceral adiposity are associated with overall survival and surgical site infections in patients with pancreatic cancer.
    Journal of Cachexia Sarcopenia and Muscle, 2016
    Co-Authors: David P J Van Dijk, Maikel Bakens, Marielle M E Coolsen, Sander S Rensen, Martijn J L Bours, Matty P Weijenberg, Cornelis H C Dejong, Steven W.m. Olde Damink
    Abstract:

    Background Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in relation to survival, post-operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas. Methods A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle Radiation Attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex-specific cut-offs were determined at the lower tertile for muscle Radiation Attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post-operative complications (Dindo–Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox-regression analysis and multivariable logistic regression analysis, respectively. Results Low muscle Radiation Attenuation was associated with shorter survival in comparison with moderate and high muscle Radiation Attenuation [median survival 10.8 (95% CI: 8.8–12.8) vs. 17.4 (95% CI: 14.7–20.1), and 18.5 (95% CI: 9.2–27.8) months, respectively; P 

R R Avezov - One of the best experts on this subject based on the ideXlab platform.

David P J Van Dijk - One of the best experts on this subject based on the ideXlab platform.

  • Low thoracic muscle Radiation Attenuation is associated with postoperative pneumonia following partial hepatectomy for colorectal metastasis.
    Hpb, 2019
    Co-Authors: Gregory Van Der Kroft, David P J Van Dijk, Sander S Rensen, Cornelis H C Dejong, Frank H. Van Tiel, Bianca T. A. De Greef, Malcolm A. West, Kristoffer Ostridge, Ulf P. Neumann, Steven W.m. Olde Damink
    Abstract:

    Abstract Background Low skeletal muscle Radiation Attenuation (SM-RA) is indicative of myosteatosis and diminished muscle function. It is predictive of poor outcome following oncological surgery in several cancer types. Postoperative pneumonia is a known risk factor for increased postoperative mortality. We hypothesized that low SM-RA of the respiratory muscles at the 4th thoracic-vertebra (T4) is associated with postoperative pneumonia following liver surgery. Methods Postoperative pneumonia was identified using prospective infection control data. Computed tomography body composition analysis was performed at the L3-and T4 level to determine SM-RA. Body composition variables were corrected for confounders and related to postoperative pneumonia and admission time by multivariable logistic regression. Results Body composition analysis of 180 patients was performed. Twenty-one patients developed postoperative pneumonia (11.6%). Multivariable analysis showed that low T4 SM-RA as well as low L3 SM-RA were significantly associated with postoperative pneumonia (OR 3.65, 95% CI 1.41–9.49, p  Conclusion Low SM-RA at either the L3-or T4-level is associated with a higher risk of postoperative pneumonia following CLRM resection.

  • Myosteatosis predicts survival after surgery for periampullary cancer: a novel method using MRI.
    Hpb, 2018
    Co-Authors: David P J Van Dijk, Sander S Rensen, Cornelis H C Dejong, Frans C. H. Bakers, Sebastian Sanduleanu, Rianne D. W. Vaes, Regina G. H. Beets-tan, Steven W.m. Olde Damink
    Abstract:

    Abstract Background Myosteatosis, characterized by inter- and intramyocellular fat deposition, is strongly related to poor overall survival after surgery for periampullary cancer. It is commonly assessed by calculating the muscle Radiation Attenuation on computed tomography (CT) scans. However, since magnetic resonance imaging (MRI) is replacing CT in routine diagnostic work-up, developing methods based on MRI is important. We developed a new method using MRI-muscle signal intensity to assess myosteatosis and compared it with CT-muscle Radiation Attenuation. Methods Patients were selected from a prospective cohort of 236 surgical patients with periampullary cancer. The MRI-muscle signal intensity and CT-muscle Radiation Attenuation were assessed at the level of the third lumbar vertebra and related to survival. Results Forty-seven patients were included in the study. Inter-observer variability for MRI assessment was low (R2 = 0.94). MRI-muscle signal intensity was associated with short survival: median survival 9.8 (95%-CI: 1.5–18.1) vs. 18.2 (95%-CI: 10.7–25.8) months for high vs. low intensity, respectively (p = 0.038). Similar results were found for CT-muscle Radiation Attenuation (low vs. high Radiation Attenuation: 10.8 (95%-CI: 8.5–13.1) vs. 15.9 (95%-CI: 10.2–21.7) months, respectively; p = 0.046). MRI-signal intensity correlated negatively with CT-Radiation Attenuation (r=−0.614, p  Conclusions Myosteatosis may be adequately assessed using either MRI-muscle signal intensity or CT-muscle Radiation Attenuation.

  • low skeletal muscle Radiation Attenuation and visceral adiposity are associated with overall survival and surgical site infections in patients with pancreatic cancer
    Journal of Cachexia Sarcopenia and Muscle, 2017
    Co-Authors: David P J Van Dijk, Maikel Bakens, Marielle M E Coolsen, Sander S Rensen, Martijn J L Bours, Matty P Weijenberg, Cornelis H C Dejong
    Abstract:

    Background Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in relation to survival, post-operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas. Methods A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle Radiation Attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex-specific cut-offs were determined at the lower tertile for muscle Radiation Attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post-operative complications (Dindo–Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox-regression analysis and multivariable logistic regression analysis, respectively. Results Low muscle Radiation Attenuation was associated with shorter survival in comparison with moderate and high muscle Radiation Attenuation [median survival 10.8 (95% CI: 8.8–12.8) vs. 17.4 (95% CI: 14.7–20.1), and 18.5 (95% CI: 9.2–27.8) months, respectively; P < 0.008]. Patient subgroups with high muscle Radiation Attenuation combined with either low visceral adipose tissue or age <70 years had longer survival than other subgroups (P = 0.011 and P = 0.001, respectively). Muscle Radiation Attenuation was inversely correlated with intermuscular adipose tissue (rp = −0.697, P < 0.001). High visceral adipose tissue was associated with an increased surgical site infection rate, OR: 2.4 (95% CI: 1.1–5.3; P = 0.027). Conclusions Low muscle Radiation Attenuation was associated with reduced survival, and high visceral adiposity was associated with an increase in surgical site infections. The strong correlation between muscle Radiation Attenuation and intermuscular adipose tissue suggests the presence of ectopic fat in muscle, warranting further investigation. CT image analysis could be implemented in pre-operative risk assessment to assist in treatment decision-making.

  • Low skeletal muscle Radiation Attenuation and visceral adiposity are associated with overall survival and surgical site infections in patients with pancreatic cancer.
    Journal of Cachexia Sarcopenia and Muscle, 2016
    Co-Authors: David P J Van Dijk, Maikel Bakens, Marielle M E Coolsen, Sander S Rensen, Martijn J L Bours, Matty P Weijenberg, Cornelis H C Dejong, Steven W.m. Olde Damink
    Abstract:

    Background Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in relation to survival, post-operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas. Methods A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle Radiation Attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex-specific cut-offs were determined at the lower tertile for muscle Radiation Attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post-operative complications (Dindo–Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox-regression analysis and multivariable logistic regression analysis, respectively. Results Low muscle Radiation Attenuation was associated with shorter survival in comparison with moderate and high muscle Radiation Attenuation [median survival 10.8 (95% CI: 8.8–12.8) vs. 17.4 (95% CI: 14.7–20.1), and 18.5 (95% CI: 9.2–27.8) months, respectively; P