PURPOSE The objective of this study was to evaluate the dosimetric feasibility of using hippocampus (HPC) sparing intensity-modulated radiotherapy (IMRT) in patients with locally advanced nasopharyngeal carcinoma (NPC). MATERIALS/METHODS Eight cases of either T3 or T4 NPC were selected for this study. Standard IMRT treatment plans were constructed using the volume and dose constraints for the...

This study evaluated the dosimetric difference between volumetric-modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (cIMRT) in whole-ventricular irradiation. Computed tomography simulation data for 13 patients were acquired to create plans for VMAT and cIMRT. In both plans, the same median dose (100% = 24 Gy) was prescribed to the planning target volume ...

Newer treatment techniques help in reducing dose to small bowel (SB) which is an organ at risk (OAR) for pelvic radiotherapy (RT). However, instead of SB, bag contoured routinely and constraints are given. In this retrospective case series, we compared the received by SB while using intensity modulated radiation therapy (IMRT) volumetric-modulated arc (VMAT) patients receiving adjuvant RT endom...

BACKGROUND Spine stereotactic body radiation therapy (SBRT) is becoming widely accepted as first-line treatment of oligometastatic spine disease as well as in the postoperative setting. The reported incidence of myelopathy is very low and guidelines vary widely on the maximum tolerable dose of the spinal cord and thecal sac. METHODS AND MATERIALS Between April 2008 and December 2010, radiatio...

Background: Breast cancer is becoming more frequently diagnosed at early stages with improved long term outcomes. Radiation-related heart disease and lung cancer can occur following radiotherapy for breast cancer. The aim of this study was to evaluate some dosimetric parameters of heart and lung during whole breast radiotherapy. Methods:Twenty five consecutive...

background: in radiation treatment of moving targets located in thorax region of patient body, the delivered dose does not match with the planned treatment, resulting in some over and under dosage in the tumor volume, as a function of motion magnitude and frequency. several efforts have been done to investigate the target motion effects on dose distribution in the target and surrounding normal ...

Unit quaternion is an ideal parameterization for joint rotations. However, due to the complexity of the geometry of S group, it’s hard to specify meaningful joint constraints with unit quaternion. In this paper, we have proposed an effective and accurate method to specify the rotation limits for joints parameterized with the unit quaternion. Joint constrains constructed with our method are adeq...

Abstract Recent advances to preserve neurocognitive function in patients treated for brain metastases include stereotactic radiosurgery (SRS), hippocampal avoidance whole radiation therapy (HA-WBRT), and memantine administration. The hippocampus, corpus callosum, fornix, amygdala are key substructures with a low propensity metastases. Herein, we report our preliminary experience using “memory-a...

The dose-volume histogram (DVH) is a clinically relevant criterion to evaluate the quality of a treatment plan. It is hence desirable to incorporate DVH constraints into treatment plan optimization for intensity modulated radiation therapy. Yet, the direct inclusion of the DVH constraints into a treatment plan optimization model typically leads to great computational difficulties due to the non...