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The purpose of radiation therapy is to use ionizing radiation, x, or gamma rays, to eradicate tumor cells, or more precisely to stop their growth without seriously damaging normal tissue. This is a difficult task since it is impossible to deliver dose solely to the target volume without affecting healthy tissues, especially when deep seated tumors are treated with external beams. In patients treated with conventional radiotherapy, the primary obstacles to achieving the maximum possible therapeutic advantage are the uncertainties in the true extent of the disease, inadequate knowledge of the...

Megavoltage electron beams are an important treatment modality used in modern radiotherapy. They often provide a unique option in treatment of superficial tumors that are less than 5 cm deep. The most clinically useful electron beams have energies ranging from 6 MeV to 15 MeV. The principal applications of electrons are: (a) in the treatment of skin and lip cancers; (b) in chest wall irradiation for breast cancer; (c) in administering boost doses to nodes; and (d) in the treatment of head and neck cancers.This work focuses on the commissioning and QA of two types of treatment planning systems...

The development of three dimensional conformal radiotherapy (3D-CRT), in which the high-dose volume matches the target volume and avoids normal tissues, has been a major theme for improving the physical basis of radiotherapy. Intensity modulated radiation therapy (IMRT) is the most advanced form of 3D-CRT. As with medical imaging, its development requires the professional activity of physicists and engineers. This study carried out in Ayadi Almostkbal Oncology Center - Alexandria, Egypt. All Dosimetric measurements were carried on siemens linear accelerator (ARTISTE) which produces photons...