PURPOSE The effectiveness of IMPT may be significantly diminished by range and patient setup uncertainties. The purpose of this presentation is to evaluate the ability of robust optimization methods to desensitize H&N IMPT plans to uncertainties and their impact on plan optimality. METHODS We use a robust optimization method, in which the objective function value for a given iteration is comp...

Over the last few years, computed tomography (CT) has developed into a standard clinical test for a variety of cardiovascular conditions. The emergence of cardiovascular CT during a period of dramatic increase in radiation exposure to the population from medical procedures and heightened concern about the subsequent potential cancer risk has led to intense scrutiny of the radiation burden of th...

The treatment planning software TRiP98 [1, 2, 3] is successfully used in the ion therapy project at GSI. A crucial part of the treatment planning is the particle number optimization in order to achieve a target dose distribution as close as possible to the prescribed biological dose distribution. The optimization task can be expressed mathematically by the minimization of a multidimensional obj...

From 1997 until 2008 about 440 cancer patients were successfully treated in the ion therapy project at GSI. The patient treatment planning was performed with the software TRiP [1, 2]. A crucial part of the treatment planning is the particle number optimization with the goal to achieve a target dose distribution as close as possible to the prescribed biological dose distribution. The optimizatio...

background: megavoltage beams used in radiotherapy are contaminated with secondary electrons. different parts of linac head and air above patient act as a source of this contamination. this contamination can increase damage to skin and subcutaneous tissue during radiotherapy.  monte carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...

The software TRiP98 [1, 2, 3] is successfully used for patient treatment planning in the GSI pilot project. A crucial part of the treatment planning is the particle number optimization. The main goal of optimization is to achieve a target dose distribution as close as possible to the prescribed biological dose distribution. Multiple field optimization (MFO) allows a better target conformity and...

background: skin cancer can be treated by various methods. electron radiotherapy has been a useful therapeutic modality in the treatment of skin cancers in areas which are difficult to cure by other methods. depth dose distribution of 166ho using varskin2 code is presented in this work. material and methods: depth dose distribution of 166ho was calculated, using varskin2 code by adding of 166ho...

background: monte carlo method (mc) has played an important role in design and optimization of medical linacs head and beam modeling. the purpose of this study was to compare photon beam features of two commercial linacs, varian 21ex and elekta sl-25 using mcnp4c mc code. materials and methods: the 6mv photon beams of varian 21ex and elekta sl-25 linacs were simulated based on manufacturers pro...

introduction: the relation between patient body mass index (bmi) and the external dose rate of thyroid cancer patients treated with 131i has been investigated. methods: a total of 183 patients treated with 131i were selected randomly and divided according to their administrated activity into three groups: 3.7gbq, 5.5gbq and 7.4gbq. they were also stratified into three groups according to their...