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Intensity Modulated Radiation Therapy is one of the most commonly used procedures of delivering radiation to cancerous tissues, with the aim of reaching the prescripted dose in the target volume while minimizing damage to nearby healthy organs. Two decisions are of fundamental importance: to select the beam angles and calculate the beam intensities. Beam Angle selection (Beam Angle Optimization) is an important problem. Due to the large amounts of computational time, beam angles are often selected manually based on human experience and intuition. In this study, three optimization methods –Simulated Annealing, Branch & Prune and Local Neighborhood Search- that are selected among known methods... 

external radiation therapy is a methods of cancer treatment or improvement of cancer-related complications. various techniques have been developed for external beam radiation therapy. Among which, Intensity Modulated Radiation Therapy (IMRT), due to its ability to adjust the intensity of radiation beams, has a higher capacity to generate appropriate dose distribution based on tumor size and volume. Intensity Modulated Radiation Therapy is one of the most commonly used procedures of delivering radiation to cancerous tissues, with the aim of reaching the prescripted dose in the target volume while minimizing damage to nearby healthy organs. Two decisions are of fundamental importance: to... 

MC Simulation is considered to be one of the most accurate methods for transport of radiation in various media. Computational speed is the limiting factor to apply the MC method in clinical settings. One of the methods to increase the speed in MC simulations is the use of phase space file (PSF). PSF is generated by transporting the particles through the linear accelerator head. The characteristics of these particles crossing a reference plane are stored in the PSF file. The PSF can be used in subsequent simulations as a radiation source. The use of PSF is effective but has a drawback of having latent variance. Latent variance is a problem inherent in using phase space files. Latent variance... 

Intensity Modulated Radiation Therapy is one of the common methods for treating cancer patients because of the ability to transfer high doses of radiation to the tumor and minimize damage to surrounding healthy organs. In this method, the patient is placed in a special bed, while a linear accelerator directs the beams to radiation to the target's size. Patient treatment requires a unique treatment plan, and optimization of the treatment plan involves two basic decisions: (1) selecting the beam angles; (2) calculating the beams intensity. In the radiation therapy process, there are various uncertainty factors, such as patient setup, tumor volume definition, tumor growth or movement, and the... 

As a method of cancer treatment or improvement of cancer-related complications, external radiation therapy is prescribed by physicians, in case of detection of a tumor in a region of patient’s body. Over time, various techniques have been developed for external beam radiation therapy. Among which, Intensity Modulated Radiation Therapy (IMRT), due to its ability to adjust the intensity of radiation beams, has a higher capacity to generate appropriate dose distribution based on tumor size and volume and it is one of the most widely used techniques in cancer treatment centers.The core process in treatment planning is using appropriate computer algorithms which results in posing enough damage to... 

Nowadays, radiation therapy is one of the most common methods for the cancer treatment. Intensity Modulated Radiation Therapy(IMRT) is a novel technique of radiation therapy that aims to delivere sufficient dose to cancerous tissues while sparing healthy organs. There are various uncertainties in radiation therapy problems, including uncertainty about device setup, device errors, interfraction and intrafraction motions. One of the most important uncertainties is the movement of the tumor during the treatment process(intrafraction motion), as this displacement may cause the cancer tissue to not receive sufficient dose and also to damage the healthy tissue due to a violation of their dose... 

Today, cancer is one of the leading causes of death globally, killing millions of people around the world every year. This indicates the need for more attention to the treatment of this disease. Cancer can be prevented from growing by being diagnosed at an early stage and choosing the proper treatment. Among cancer treatment methods, radiation therapy is one of the most widely used methods, and Intensity-Modulated Radiation Therapy (IMRT) is one of the most efficient and resilient methods of radiation therapy. In the IMRT treatment plan, the optimal choice of radiation intensity is of particular importance abd the mathematical modeling problems related to determining the intensity of beams...