background: radiotherapy plays an important role in the management of most malignant and many benign primary central nervous system (cns) tumors. radiotherapy affects both tumor cells and uninvolved normal cells; so, it is important to estimate absorbed dose to organs at risk in this kind of treatment. the aim of this study was to determine the absorbed dose to chiasma, lens, optic nerve, retin...

Abstract One of the most challenges to effective treatment cancer is radiation resistance. Published data from a notably experiment performed examine ability compound therapy overcome resistance utilized. The chemotherapeutic drug used was vinblastine. included control tumors and which were treated with radiation, chemotherapy, or both. In this paper mathematical model developed. fits reported ...

Background: While randomized trials have established that palliative radiotherapy, especially to bone, can improve qualitative measures of pain, its quantitative relationship opioid prescribing patterns has remained underexplored. We aimed identify the association radiotherapy on prescriptions received among patients with metastatic cancer.

unfortunately, last winter, we lost one of the leaders of radiotherpy-oncology in iran, professor mohammad hossein salehi. he was an excellent teacher, a supportive friend and an experienced physician.professor salehi was born on april 21, 1941 in shirvan. after graduating from high school, he continued his education in mashhad medical school. in 1968 he completed medical school and began the r...

BACKGROUND To investigate the risk of second cancer and radiation induced second cancer following prostate cancer radiotherapy. METHODS We compared men with radiotherapy only with those treated with radical prostatectomy only and those with radiotherapy after radical prostatectomy. Cumulative incidences of second cancers were calculated. Cox analyses were performed to identify determinants in...

Introduction: Radiotherapy is one of the effective methods in the treatment of cancer. In the recent methods of radiotherapy, intensity modulated radiotherapy (IMRT) technique by compensators is used. when photon beam passes the compensator, scattered photons can be generated within the compensator. The presence of scattered photons may complicate the design of compensators as...

Background: In the radiotherapy of patients with esophagus and breast cancer, the heart receives a significant dose of radiation that might cause heart complications. Thefore, the aim of the current study was to evaluate the effects of esophagus and left breast cancer radiotherapy on the cardiac function and to determine the relationship between the dosimetric parameters and ejection fraction (...

background: craniospinal radiotherapy faces technical challenges which are due to the sensitivity of the location in which the gross tumor is, and to organs at risk around planning target volume. using modern treatment planning systems causes a reduction in the complexities of the treatment techniques. the most effective method to assess the dosimetric accuracy and the validity of the software ...

background : central nervous system tumors account for 2%-5% of all malignancies in humans. these tumors account for 2% of all pediatric cancers. the worldwide incidence of primary central nervous system tumors is estimated at 3.9 (males) and 3.2 (females) per 100000 person-years. the incidence of brain tumor cases has been reported as 3.67% of all malignancies and 4% of all cancer mortalities ...