Introduction: In external beam radiotherapy each effort is done to deliver 3D dose distribution onto the tumor volume uniformly, while minimizing the dose to healthy organs at the same time. Radiation treatment of tumors located at thorax region such as lung and liver has a challenging issue during target localization since these tumors move mainly due to respiration. There are...

Background: Respiratory motion causes thoracic movement and reduces targeting accuracy in radiotherapy. Objective: This study proposes an approach to generate a model to track lung tumor motion by controlling dynamic multi-leaf collimators. Material and Methods: All slices which contained tumor were contoured in the 4D-CT images for...

Introduction: In radiation therapy, determining the location of the tumor accurately during irradiation is one of the most important requirements. However, lung tumors are not fixed in a single location and move during irradiation due to respiratory motion. Due to limitations in assessing such movements, using a lung phantom can be useful and operational for their fast, easy an...

Introduction: In radiotherapy with external surrogates, exact information of tumor position is one of the key factors that improves treatment delivery. Many dynamic tumors in thorax region of patient move mainly due to respiration and are known as intra-fractional motion error that must be compensated, as well. One of clinical strategy is using Stereotactic Body Radiation Thera...

The most common cause of cancer death in both men and women is lung cancer. External Beam Radiation Therapy (EBRT) is one of the primary treatment methods used for lung cancer. However, dosimetric accuracy is often compromised due to respiration-induced tumor motion. Real-time tumor tracking is a common approach for lung tumor motion compensation as it allows for fast and accurate radiation del...

PURPOSE For lung cancer patients with poor pulmonary function because of emphysema or fibrosis, it is important to predict the amplitude of internal tumor motion to minimize the irradiation of the functioning lung tissue before undergoing stereotactic body radiotherapy. METHODS AND MATERIALS Two board-certified diagnostic radiologists independently assessed the degree of pulmonary emphysema a...

malignant fibrous histiocytoma (mfh) is the most common soft-tissue sarcoma which predominantly surfaces in the retro-peritoneum and extremity. mfh of lung is a very rare condition. the diagnosis is essentially through histologic examination. however, the invasion of the chest wall or other organs might help establish the malignant nature.we report a case of a 77-year-old man who had been prese...

Lung tumor motion due to respiration poses a challenge in the application of modern three-dimensional conformal radiotherapy. Direct tracking of the lung tumor during radiation therapy is very difficult without implanted fiducial markers. Indirect tracking relies on the correlation of the tumor's motion and the surrogate's motion. The present paper presents an analysis of the correlation betwee...

objective(s): considering the fact that the standardized uptake value (suv) of a normal lung tissue is expressed as x±sd, x+3×sd could be considered as the threshold value to outline the internal tumor volume (itv) of a lung neoplasm. methods: three hollow models were filled with 55.0 kbq/ml fluorine18- fluorodeoxyglucose (18f-fdg) to represent tumors. the models were fixed to a barrel filled w...

introduction bronchial adenoma is rare in primary tumors of the lung and produce non-specific respiratory symptoms. case presentation a 4-year-old boy referred to our clinic with chronic cough and wheezing. foreign body aspiration was recommended for him on the base of radiologic and clinical manifestation. in bronchoscopy, foreign body was not detected, but an obstructing tumor was found at le...