Azza Helal - Academia.edu (original) (raw)
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Papers by Azza Helal
Practical radiation oncology, Jan 2, 2017
When treating breast cancer with radiation therapy, the impact of treatment position on heart and... more When treating breast cancer with radiation therapy, the impact of treatment position on heart and lung dose-volume parameters (DVPs) is largely dependent on the maximal heart distance (MHD) and central lung distance (CLD). We evaluate how much heart and lung sparing can be achieved using the semilateral decubitus (SLD) position without and with breath hold compared with the standard supine position for left-sided breast cancer patients. A secondary aim was to investigate the impact of MHD and CLD on heart and lung DVPs. Thirty-five left-sided breast cancer patients were simulated in supine, free breathing SLD, and SLD with breath hold positions. A dosimetry plan was developed for each of these and 3 plans were compared for target coverage and organs at risk sparing. A correlation between CLD, MHD, and planning target volume, and heart and ipsilateral lung DVPs was tested. SLD breath hold position showed a significant reduction in percentage of heart receiving ≥5 Gy (V), V, VV, mean ...
Introduction: The dose distribution of 3DCRT planning depends on number of beams, geometry of tar... more Introduction: The dose distribution of 3DCRT planning depends on number of beams, geometry of target volume, number and tolerance of surrounding organs at risk (OARs). Aim: To study the interacting effects of target volume, OAR geometry and planning parameters on the resulting dose distribution in the target volume and OARs for 3DCRT plans for patients with advanced non metastatic hepatocellular carcinoma (HCC). It also aims at identifying which combination of these factors influencing the dose volume parameters and dose distribution and the selection of beam number among patients with HCC. Methods: CT studies of 30 patients with unresectable HCC were planned using different number, direction and energy of photon fields. The volume and length of planning target volume (PTV), volume of whole and healthy liver and the ratio of the volume of PTV to whole liver volume were calculated. Linear regression was used to identify which combination of the anatomic factors influences the dose di...
Alexandria Journal of Medicine, 2013
Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radi... more Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radiotherapy techniques. However they irradiate differently the surrounding organs at risk (OARs) in particular the cochlea, oral cavity & contralateral parotid causing significant increase in the risk of oral mucositis, xerostomia, and hearing deficits on the irradiated side. Objectives: The aim of this study was to compare radiation doses received by target volume and different surrounding OARs using three different parotid irradiation techniques aiming to achieve the optimum technique which shows adequate target coverage and sparing of surrounding OARs during postoperative 3DCRT treatment of parotid gland cancer patients. Methodology: Ten patients diagnosed as having parotid cancer were included in this study. They were subjected to CT simulation and scans were transferred to the treatment planning system. Target volumes and contralateral parotid, oral cavity, cochlea, spinal cord, brain stem, eyes, lenses and optic nerves were contoured. Three plans were done using (a) ipsilateral oblique wedged photon
Practical radiation oncology, Jan 2, 2017
When treating breast cancer with radiation therapy, the impact of treatment position on heart and... more When treating breast cancer with radiation therapy, the impact of treatment position on heart and lung dose-volume parameters (DVPs) is largely dependent on the maximal heart distance (MHD) and central lung distance (CLD). We evaluate how much heart and lung sparing can be achieved using the semilateral decubitus (SLD) position without and with breath hold compared with the standard supine position for left-sided breast cancer patients. A secondary aim was to investigate the impact of MHD and CLD on heart and lung DVPs. Thirty-five left-sided breast cancer patients were simulated in supine, free breathing SLD, and SLD with breath hold positions. A dosimetry plan was developed for each of these and 3 plans were compared for target coverage and organs at risk sparing. A correlation between CLD, MHD, and planning target volume, and heart and ipsilateral lung DVPs was tested. SLD breath hold position showed a significant reduction in percentage of heart receiving ≥5 Gy (V), V, VV, mean ...
Introduction: The dose distribution of 3DCRT planning depends on number of beams, geometry of tar... more Introduction: The dose distribution of 3DCRT planning depends on number of beams, geometry of target volume, number and tolerance of surrounding organs at risk (OARs). Aim: To study the interacting effects of target volume, OAR geometry and planning parameters on the resulting dose distribution in the target volume and OARs for 3DCRT plans for patients with advanced non metastatic hepatocellular carcinoma (HCC). It also aims at identifying which combination of these factors influencing the dose volume parameters and dose distribution and the selection of beam number among patients with HCC. Methods: CT studies of 30 patients with unresectable HCC were planned using different number, direction and energy of photon fields. The volume and length of planning target volume (PTV), volume of whole and healthy liver and the ratio of the volume of PTV to whole liver volume were calculated. Linear regression was used to identify which combination of the anatomic factors influences the dose di...
Alexandria Journal of Medicine, 2013
Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radi... more Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radiotherapy techniques. However they irradiate differently the surrounding organs at risk (OARs) in particular the cochlea, oral cavity & contralateral parotid causing significant increase in the risk of oral mucositis, xerostomia, and hearing deficits on the irradiated side. Objectives: The aim of this study was to compare radiation doses received by target volume and different surrounding OARs using three different parotid irradiation techniques aiming to achieve the optimum technique which shows adequate target coverage and sparing of surrounding OARs during postoperative 3DCRT treatment of parotid gland cancer patients. Methodology: Ten patients diagnosed as having parotid cancer were included in this study. They were subjected to CT simulation and scans were transferred to the treatment planning system. Target volumes and contralateral parotid, oral cavity, cochlea, spinal cord, brain stem, eyes, lenses and optic nerves were contoured. Three plans were done using (a) ipsilateral oblique wedged photon