Introduction: Squamaus cell carcinoma is the most common tumor of head and neck. According to clinical stage of disease, radiotherapy and/or surgery is (are) used far treatment of these tumors. Although improvement of treatment results has been reported with chemoradiotherapy, still some controversy exists about the benefit of adding chemotherapy. This study-compares chemoradiotherapy vs radiotherapy alone. Materials and methods: One hundred and fifty patients with squamous cell carcinoma of head and neck were categorized into two groups randomly. The first group was designed to receive conventional fractionation radiation therapy (75 patients), ranging from 50 to 70 Gy (5 fractions per week and 2 Gy per fraction) and the other group was planned to get combined chemoradiotherapy (75 patients). Chemotherapy regimen consisted of cisplatin (100mg/m2) and 5-flluorouracil (750mg/m2), given every 3 weeks concurrent or after radiotherapy. Results: Initial response was seen in 69.4% following radiotherapy and 85.7% after chemoradiation (p=0.031). Recurrence (locoregional or distant) was seen in 46.7% and 26.2% of patients in radiotherapy and chemotherapy group, respectively. Mean time for recurrence after treatment was 8.58 and 7.17 months in 2 groups, respectively.Conclusion: Addition of chemotherapy to radiotherapy causes decrease in recurrence and increase in initial response rate in squamous cell cancers of head and neck.

Background: The selective treatment of internal mammary chain (IMC) in breast cancer is controversial. Previous randomized trials have not shown a benefit to IMC irradiation. The recent positive trials testing post mastectomy radiation that had included IMC irradiation has renewed interest in their irradiation. The purpose of this retrospective survey was to evaluate outcome as a function of IMC in a cohort of breast cancer patients treated with modified radical mastectomy (MRM) and radiation therapy (RT).Materials and Methods: From 1987 to 2001, the files of 215 patients with invasive breast cancer that were treated with MRM+RT were reviewed. The mean time of follow up was 74 months. All of the patients received chemotherapy and regional radiation (supraclavicular, axillary with or without IMC). The decision to use or not use a separate IMC field was the result of change in treatment policy over time. To evaluate the results, patients were divided into two groups: those who received IMC radiation (IMC group, 120 patients), and those without IMC radiation therapy (control group, 95 patients). Five years disease free survival rate, metastasis and loco regional recurrence was calculated in two groups. To determine the patients who can benefit from radiotherapy the metastasis in two groups was analyzed according to age, the location of tumor, the stage of disease and the situation of axillary lynph nodes.Results: Distant metastasis and loco regional recurrence occurred in 42(35%) and 10(8.3%) patients in IMC group and 37 (38.94%) and 7 (7.3%) patients in control group, respectively. These differences were not significant between 2 groups. Subset analysis showed that distant metastasis occurred less frequently in IMC group when the location of tumor was inner quadrant (42.85% vs 75%) and stage ?a was (38.2% vs 84.6%) (p<0.001). Five years disease free survival rate was 57% and 50% in IMC and control group respectively.Conclusion: Regards to the results of this retrospective analysis, it could be concluded that IMC radiation in breast cancer patients is not beneficial. This treatment should be considered only for those with inner quadrants and stage IIIa tumors.

Introduction: Endocrinopathy is a known consequence of external beam radiotherapy to the brain tumors. The aim of this study was to find out the incidence of hyperprolactinemia in brain tumor patients treated with radiotherapy, when radiation portals included whole of the hypothalamus and pituitary glands.Materials and Methods: This descriptive study was conducted from December 2004 to February 2006 on about 42 patients with brain tumors, who were referred to radiation oncology center of Hamadan to be treated with external beam radiotherapy, whose radiation portals included whole hypothalamus and pituitary glands. Serum prolactin levels were measured at the beginning of treatment, and at one month, three months, six months and one year after completion of radiotherapy. Data was introduced using descriptive statistics.Results: Of 42 patients 6 were excluded which one was because pf previous hypothalamus and pituitary radiotherapy, three because of nonadherence to follow up program and two because of previous endocrinopathy Of the patients attending the follow up clinic, 11% were found to have hyperprolactinemia at six months and 22 at one year. This condition in women and men was 37% and 15% respectively.Conclusion: Abnormality in prolactine secretion is a late complication of brain radiotherapy and a significant number of patients develop hyperprolactinoma following radiotherapy to the brain (hypothalamus and pituitary region). It seems this complication increases by increasing the radiation dose and is more prevalent in women.

Purpose: Some cancer patients who receive radiation therapy have metal objects in their body. There is a difference between atomic numbers of these metal objects and body tissues. This creates artifacts in images and creates large difference in CT numbers and errors in the calculations. This study was performed to evaluate the effect of correcting metal artifact on images and compare the absorbed dose estimated by ISOgray treatment planning system (TPS) and measurement. Methods: Homogeneous cylindrical phantom was prepared from Perspex material to simulate human body conditions. Cavities were created for Farmer dosimeter and titanium metal rods acting as prosthesis. CT images of phantom were acquired in the presence and absence of metal rods. The correction of metal artifact was performed using Metal Detection Technique (MDT) and CT control softwares. Dose calculation was done at the phantom center for 100 MU at the photon mode with the energies of 6, 10 and 15 MV at ISOgray TPS. The results were compared with Farmer dosimeter. Results: The results show that there is no significant difference in absorbed dose calculated for different images corrected using two softwares by ISOgray TPS. The lowest and highest errors are 0. 1% and 1. 09% related to the images corrected by MDT software with the slice thickness of 3. 0 cm and the distance of 2. 5 cm and photon energies of 6 and 15 MV, respectively. Conclusion: The correction of artifacts in CT images does not have a significant effect on the dose calculated by ISOgray.

The major aim of radiotherapy is the definite therapy of the tumor while remaining the surrounding tissue intact. To meet this demand, the difference of administered dosage and transferred dosage should be less than 2%. To calculate the tumor dosage, radiotherapy instrument's output is measured for a reference field (10x10 cm2). This study has been carried out with the aim of surveying the necessity of using the scatter coefficient to convert the reference field output to other fields output used in radiotherapy.Total scatter coefficient, Scp, collimator, Sc, and phantom Sp were determined. Sc was measured in a cylindrical phantom prepared in this research, however, Scp was measured in a water phantom. Sp was calculated regarding Sc and Scp amounts. When the amount of collimator field was differing from that of phantom field, the accuracy of Scp separation method into Sc and Sp was assessed by comparing the amounts of Scp measured in blocked fields.Results have revealed that in case of not using scatter coefficient, for Satren linear accelerating beam of 12mv,the transferred dosage would differ from the administered dosage in a range of +15% ( in the biggest field) to -6% (in the smallest field). For calculating the dosage in blocked fields, the accuracy of separation method of Scp to Sc for collimator field and Sp for phantom field was confirmed (maximum deviation of experimental measurement was 1.3%). When using phantom field for Scp selection, the tumor dosage was 2.4-7.8% (27-90% for block) higher than the administered dosage for the beam of 12mv (error increased by block increasing or approximating the block to the center).

Background: There is considerable controversy in scientific literature regarding the need to monitor the complete blood count of patients undergoing radiation therapy. While some advocate weekly examination of the peripheral blood, others deem it unnecessary. Since reduction in the number of blood cells has considerable effect on the treatment outcome, this study evaluates the effect of pelvic radiation therapy on the number of blood cells. Methods and Materials: This study designed as a cohort study of pre- and post-treatment evaluation. After excluding patients who didn’t complete treatment or had problem in first blood count, 51 patients who had received radiation therapy in pelvis area selected, evaluated by taking a blood sample before and 24-48 hours after completion of the radiation course, thus comparing the mean count of the circulating blood cells before and after therapy. The average of hemoglobin and white blood cell count compared by t-test and after stratified patients according to dose and volume to “low”, “moderate” and “high” groups, averages compared by ANOVA. Results: Fifty-one patients included 25 male and 26 female evaluated. The mean of white blood cells, red blood cells and platelets decreased. However, a significant difference in white and red blood cells was found. Conclusions: In despite of significance difference between means of red and white blood cells, there is no need for blood transfusion or increase risk of infection due to this reduction, so this reduction isn’t clinically significant. It is recommended that weekly monitoring of CBC in patients with normal CBC before radiotherapy is non necessary.

Background: The aim of radiation therapy is to deliver a precisely measured dose of irradiation to a defended tumor volume. Simulation has been used instances to document the configuration of the portal and target volume to be irradiated accurately. Unfortunately, there is non-Conventional simulation in most of cancer centers in Iran. There fore in this study, it was tried to estimate pelvic inlet from inrerspinous diameter (distance between two Ant. Sup. Iliac spine) of the aforementioned patients in Radiotherapy – Oncology Department in Imam Hossein hospital. Materials and methods: Interspious diameter on the surface kin (X) and pelvic inlet (Y) on simulation in the 44 men and 61 women were determined, coefficient (r) in men and women rm=0.8841 rw=0.8141 and linear regression analysis the following equation was obtained. Y=0.525X-0.339 R2=0.7815 for men Y=0.326 X+5.18 R2=0.6626 for women Conclusion: It was concluded that in both men and women, it is possible to estimate pelvic Inlet diameter from Interspinous diameter. But the coefficient of determination (Rsq) is lower in women than men.

Background and objectives: Accuracy of the delivered dose to the patient is one of the most important and effective factors in radiotherapy. In vivo dosimetry is used to evaluate the accuracy of delivered dose in radiotherapy. Therefore, in this study the accuracy of delivered dose to the patients was verified using in vivo dosimetry in radiotherapy department of Tabriz Imam Hospital.Materials and Methods: Entrance doses of 320 fields treated by Cobalt-60 machine and linear accelerator including head and neck, trunk, pelvis, and extremities were measured using in vivo dosimetry system. Difference between measured entrance dose and prescribed dose for each field was determined. For all fields and also for each specific group of fields, average error and standard deviation of its distribution were determined.Results: For whole fields, the average error of 1.34% with standard deviation (SD) of 7.12%, for 60Co fields the average error of -0.17% with SD of 5.98% and for Linac fields, the average error of -3.56% and 7.17% were seen. In head and neck fields, the average error of -0.37% with SD of 4.73%; for trunk fields the average error of %-1.88 with SD of 7.27%, and for pelvis and extremities, the average error of -2.49% with SD of 7.79% were seen.Conclusion: The results show an acceptable systematic error in radiotherapy department.But standard deviation of 7.12% is slightly higher than the recommended value of 5%. It is possible to lower the uncertainty in delivered dose to recommended value by optimization of Linac function, regular quality control, and workload reduction.

The major goal of radiation therapy is the delivery of a prescribed radiation to target volume and preserving normal tissue. There are several geometric factors, which tend to compromise this goal. Geometric errors (field placement errors) cause the treatment fields not to be reproducible during the treatment course. In this study geometric errors of radiotherapy fields determined by portal films. Proper film and thickness of cassette front screen to produce the highest contrast were selected in radiotherapy by CO60 gamma rays and 12MV X-rays. 20 patients with head and neck and pelvis region tumors were chosen for our study. On average 4 portal films were taken for each patient during their treatment course. A total of 82 portal films were obtained. For each patient portal films compared with the simulator film and fields placement error were measured for each case. Average systematic and random errors as well as angle of rotation were calculated. The Calculated values were 10.3±6.8 mm along X-axis, 11.3± 13 along Y-axis and angle of rotation was 3.8±3.9. Field placement errors, considering 5 mm as a tolerance limit was 60% along X-axis and 64% along Y-axis. Results of this study shows that systematic and random errors were higher than values previously suggested by other investigations. The problem seems to exist due to lack of immobilization devices, positioning lasers and portal imaging.