Nuclear Oncology

Posts Tagged ‘Malignant tumor’

Intensity Modulated Radiotherapy (IMRT) is an advanced mode of high precision radiotherapy linear accelerators using x-ray computer-controlled for precise radiation doses to a malignant tumor or specific areas within the tumor. IMRT allows the radiation dose to conform more precisely to the three-dimensional (3-D) of the tumor by modulating (or control) the intensity of the radiation beam in several small volumes. IMRT also allows higher doses to focus on regions within the tumor while minimizing radiation exposure to surrounding normal critical structures. Treatment is carefully planned with the help of three-dimensional images of computed tomography (CT) or magnetic resonance imaging (MRI) of the patient, along with computerized dose calculations to determine the dose intensity pattern that best suits the shape of tumor. In general, combinations of multiple intensity modulated fields coming from different beam directions produce a radiation dose that maximizes individual dose to the tumor while minimizing doses to adjacent normal tissue.

Because IMRT the dose rate compared to normal tissue dose to tumor is minimized, can be given higher doses of radiation, effective and safe to tumors with fewer side effects compared to radiation therapy techniques conventional. IMRT also has the potential to reduce treatment toxicity, even at doses not increased. Because of its toxicity, IMRT compared with conventional radiotherapy, requires a slightly longer time of daily treatment, additional planning and security checks before the patient can begin treatment. Read the rest of this entry »

A brain tumor is a group of abnormal cells growing in the brain or around it. Tumors can directly destroy healthy brain cells. They can also indirectly damage to invade other parts of the brain and cause inflammation, brain swelling and pressure inside the skull.

Brain tumors can be malignant or benign. A malignant tumor, also called brain cancer, grows rapidly and often invades the healthy areas of the brain. Benign tumors do not contain cancer cells. Watching them look normal under a microscope, usually grow slowly.

Brain tumors can be of two types: primary or metastatic. Primary brain tumors originate in the brain, and metastatic cancer cells appear when another part of the body spread to the brain. Therefore, metastatic brain tumors are almost always malignant, while primary tumors may be benign or malignant.

Brain tumors are classified according to tumor location, type of tissue involved, if the tumor is benign or malignant, and other factors. If it is determined that a tumor is malignant, the cells are examined under a microscope to determine their degree of malignancy. According to this analysis, tumors classified by their degree of malignancy from least to most malignant. Some factors that determine tumor grade are the growth rate of cells, the amount of blood supplied to the cells, the presence of dead cells in the center of the tumor (necrosis), if cells are confined to a specific area, and the degree of similarity between cancer cells and normal cells. Read the rest of this entry »