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Background: Treatment response in High-grade Glioma (HGG) patients changes based on their genetic and biological characteristics. MiRNAs, as important regulators of drug and radiation resistance, and the Apparent Diffusion Coefficients (ADC) value of tumor can be used as a prognostic predictor for glioma.Objective: This study aimed to identify some of the pre-treatment individual patient features for predicting the treatment response in HGG patients.Material and Methods: In this prospective study, 18 HGG patients, who were candidated for chemo-radiation treatment, participated after informed consent of the patients. The investigated features were the expression level of miR-222 and miR-205 in plasma, the ADC value of tumor, Body Mass Index (BMI), and age. Treatment response was assessed, and Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to obtain a model to predict the treatment response. Mann-Whitney U test was also applied to select the variables with a significant relationship with patients’ treatment response.Results: The LASSO coefficients for miR-205, miR-222, tumor’s mean ADC value, BMI, and age were 3.611, -1.683, 2.468, -0.184, and -0.024, respectively. Mann-Whitney U test results showed miR-205 and tumor’s mean ADC significantly related to treatment response (P-value˂0.05). Conclusion: The miR-205 expression level of the patient in plasma and tumor’s mean ADC value has the potential for prognostic predictors in HGG.

Abstract Background We focused on Differentiated pseudoprogression (PPN) of progression (PN) and the response to radiotherapy (RT) or chemoradiotherapy (CRT) using diffusion and metabolic imaging. Methods Seventy-five patients with glioma were included in this prospective study (approved by the Iranian Registry of Clinical Trials (IRCT) (IRCT20230904059352N1) in September 2023). Contrast-enhanced lesion volume (CELV), non-enhanced lesion volume (NELV), necrotic tumor volume (NTV), and quantitative values ​​of apparent diffusion coefficient (ADC) and magnetic resonance spectroscopy (Cho/Cr, Cho/NAA and NAA/Cr) were calculated by a neuroradiologist using a semi-automatic method. All patients were followed at one and six months after CRT. Results The results of the study showed statistically significant changes before and six months after RT-CRT for M-CELV in all glioma types (𝑝 < 0.05). In glioma cell types, the changes in M-ADC, M-Cho/Cr, and Cho/NAA indices for PN were incremental and greater for PPN patients. M-NAA/Cr ratio decreased after six months which was significant only on PN for GBM, and Epn (𝑝 < 0.05). A significant difference was observed between diffusion indices, metabolic ratios, and CELV changes after six months in all types (𝑝 < 0.05). None of the patients were suspected PPN one month after treatment. The DWI/ADC indices had higher sensitivity and specificity (98.25% and 96.57%, respectively). Conclusion The results of the present study showed that ADC values and Cho/Cr and Cho/NAA ratios can be used to differentiate between patients with PPN and PN, although ADC is more sensitive and specific.

Background: Glioma is the most common primary brain tumor, and early detection of tumors is important in the treatment planning for the patient. The precise segmentation of the tumor and intratumoral areas on the MRI by a radiologist is the first step in the diagnosis, which, in addition to the consuming time, can also receive different diagnoses from different physicians. The aim of this study was to provide an automated method for segmenting the tumor and intratumoral areas. Methods: This is a fundamental-applied study that was conducted from May 2020 to September 2021 using multimodal MRI images of 285 patients with glioma tumors from the BraTS 2018 Database. This database was collected from 19 different MRI imaging centers, including multimodal MRI images of 210 HGG patients, and 75 LGG patients. In this study, a 2D U-Net architecture was designed with a patch-based method for training, which comprises an encoding path for feature extraction and a symmetrical decoding path. The training of this network was performed in three separate stages, using data from high-grade gliomas (HGG), and low-grade gliomas (LGG), and combining two groups of 210, 75, and 220 patients, respectively. Results: The proposed model estimated the Dice Similarity Coefficient (DSC) results in HGG datasets 0.85, 0.85, 0.77, LGG datasets 0.80, 0.66, 0.51, and the combination of the two groups 0.88, 0.79, 0.77 for regions the whole tumor, tumor core, and enhancing region in the training dataset, respectively. The results related to Hussdorf Distance (HD) for HGG datasets were 8.24, 9.92, 4.43, LGG datasets 11.5, 11.31, 2.23, and the combination of the two groups 7.20, 8.82, 4.43 for regions the whole tumor, tumor core, and enhancing region in the training dataset, respectively. Conclusion: Using the U-Net network can help physicians in the accurate segmentation of the tumor and its various areas, as well as increase the survival rate of these patients and improve their quality of life through accurate diagnosis and early treatment.

Background: The goal of this study was to make a dosimetric comparison between the absorbed dose distribution of the prostate and the organ at risk (OAR) using two different approaches: three-dimensional conformal radiotherapy (3D-CRT) and Intensity-modulated radiotherapy (IMRT), assesed via treatment planning system (TPS) and thermoluminescence dosimetry (TLD). Methods: In this study, 35 patients with prostate cancer undergoing radiation therapy at Milad Hospital in Isfahan were included. Prostate as target and rectum, bladder and femoral head as healthy organ at risk (OAR) were contoured according to Radiation Therapy Oncology Group (RTOG) criteria. Two separate dosimetry programs IMRT and 3D-CRT have been developed for each patient in order to evaluate the dosimetric status of both methods comparatively. These results were then compared with those of the phantom. Findings: The doses to the bladder, rectum, and femoral head were 50.3, 58.6, and 16.4 in IMRT and 59.6, 68.8, and 34.8 in 3D-CRT, respectively. The dose measured by TLD in all organs in the phantom was higher than the dose calculated by TPS software in the phantom. Conclusion: The IMRT method is a better method than 3D-CRT due to better coverage of the target volume and reduction of the cumulative dose of organs at risk (OAR). The dose measured by TLDs was higher than the dose calculated by the treatment planning system, which may be due to the fact that the treatment planning system does not calculate the share of scattered radiation in the absorbed dose of organs.

Abstract Background Investigation of novel blood‐circulating agents as potential biomarkers for glioblastoma multiforme (GBM) patients’ diagnosis and monitoring has gained lots of attention, due to limitations of imaging modalities and invasive tissue biopsy procedures. The present study aims to assess the diagnostic and prognostic values of preoperative stem cell factor (SCF) plasma level in GBM patients. Methods Preoperative plasma samples from 58 GBM patients and 20 patients with nonglial tumors and 30 healthy controls were obtained. SCF levels were measured by employing the enzyme‐linked immunosorbent assay test and the values were compared between these three groups. Then, the association of SCF plasma level and tumor volume, progression‐free survival (PFS), and overall survival (OS) for the GBM patients were evaluated. Results Mean preoperative SCF plasma level of the GBM patients (2.80 ± 1.52 ng/ml) was significantly higher (p

Background: To date, different kinds of treatment methods have been proposed for radiotherapy of cancer patients. Choosing the kind of treatment method affects the quality of the patientchr('39')s treatment. This study aims to investigate the effect of the number of radiation treatment sessions on the dose received by the patient and the distribution of tumor dose and dose received by organs at risk in breast cancer radiation therapy. These results help us to select the appropriate treatment schedules for the treatment of left breast patients. Methods: This prospective cross-sectional study was performed on the treatment plans of 35 patients with left breast cancer who referred to Isfahan Milad Hospital between July 2019 and April 2020. They were candidates for left breast radiation therapy. Also, these patients had no history of surgery or chemotherapy, and no supraclavicular or axillary lymph nodes were involved. Patients were treated with a conventional fraction regimen (CF) or hypofractionated (HF) treatment schedule. Different dosimetry parameters for the target and organ at risks such as conformity index, homogeneity index and mean dose were obtained from the dose-volume histogram plot. Finally, the results of both plans were compared with each other. Results: The data obtained from this study indicate a decrease in the average dose of all organs in the hypo fractionated regimens compared to conventional plans. The differences between two plans were statistically significant for tumor, lung, and skin (P=0.0). Moreover, the maximum dose for the skin was also reduced when hypofractionated regimens were used. However, the values of the homogeneity index and conformity index of tumor in the two methods did not show a significant difference (P were 0.99 and 0.86, respectively). Conclusion: In general, the results of the current study indicate that the hypofractionated regimen leads to a reduction in dosimetric factors compared to conventional fraction plans. It seems that this method can be used as an alternative treatment plan for breast cancer radiation therapy due to the reduced duration of the treatment period.

Background: Intensity-Modulated Radiation Therapy (IMRT) is one of the best methods in the treatment of optic nerve sheath meningioma (ONSM) with tumor growth control and visual stabilization. In this study, various IMRT techniques were evaluated from the point of view of dose fall-off beyond the target boundaries to achieve the optimal technique. Methods: The optimization of 3 IMRT techniques was performed using 3, 5, and 7 fields with 6 MV photons in 15 patients with ONSM using Prowess Panther treatment planning system. To evaluate treatment plans, in addition to data extracted from dose-volume histogram (DVH) and evaluation of target coverage indices, differential and cumulative dose gradient indices (DGIs) were calculated and compared between the three techniques. Findings: The maximum and the mean dose received by the tumor increased with increasing number of IMRT fields. The uniformity (UI) and homogeneity (HI) indices were significantly different between the 3-field and 7-field techniques; and the conformity index (CI) was close to ideal value (0.99) in 7-field technique. Difference of differential dose gradient index (dDGI) was negligible between the three techniques, and only at the 45% isodose level, there was a significant difference between the 5- and 7-field techniques. Cumulative dose gradient index (cDGI) showed smaller values in 7-field technique than the other two techniques. Conclusion: The three IMRT techniques have no considerable statistical difference in dose fall-off rate beyond tumor boundaries; and their choice in the treatment of ONSM depends on the physician's discretion based on the whole patient's conditions.

مقدمه: کم شنوایی حسی- عصبی، از عوارض پرتودرمانی در بیماران مبتلا به تومورهای مغزی می‌باشد. سیستم شنوایی بیماران مبتلا به تومورهای مغزی درون میدان تابشی قرار می‌گیرد و دوز قابل توجهی از پرتو را دریافت می‌کند و شنوایی را کاهش می‌دهد. هدف از انجام این مطالعه، مقایسه‌ی مشخص کردن حجم (کانتور) و دوز محاسبه شده‌ی حلزون گوش و گوش داخلی در دو روش درمانی دو بعدی سنتی (Two-dimensional یا 2D) و سه بعدی تطبیقی (Three-dimensional یا 3D) در بیماران مبتلا به تومورهای مغزی بود. روش‌ها: در این مطالعه‌ی موردی- مقطعی، تصاویر Computed tomography scan (CT scan) 43 بیمار (23 مرد و 20 زن) مبتلا به تومور مغزی که در سال 1395 به مرکز پرتودرمانی بیمارستان میلاد اصفهان مراجعه کردند، مورد استفاده قرارگرفت. کانتور کردن حلزون گوش و گوش داخلی روی CT scan بیمار توسط پزشک انکولوژیست در نرم‌افزار طراحی درمان TiGRT انجام گرفت. هیستوگرام‌های دوز (Dose volume histogram یا DVH) روش‌های پرتودرمانی دو بعدی و سه بعدی محاسبه و مقایسه گردید. یافته‌ها: میانگین دوز رسیده در روش دو بعدی برای حلزون گوش برابر 7/338 ± 0/2624 و برای گوش داخلی 3/341 ± 0/2718 سانتی‌گری و در روش پرتودرمانی سه بعدی برای حلزون گوش 6/294 ± 0/2507 و برای گوش داخلی 6/295 ± 0/2581 سانتی‌گری بود. میانگین دوز حلزون گوش و گوش داخلی در روش سه بعدی به ترتیب 3/5 و 6/4 درصد کمتر از روش دو بعدی بود. در کل، اختلاف معنی‌داری بین دوز رسیده به حلزون گوش و گوش داخلی در روش دو بعدی (846/0 = P) و سه بعدی (859/0 = P) وجود نداشت. نتیجه‌گیری: با توجه به عدم وجود اختلاف معنی‌داری بین دوز رسیده به حلزون گوش و گوش داخلی در روش دو بعدی و سه بعدی در بررسی پارامترهای دوزیمتریک مربوط به سیستم شنوایی، در طراحی درمان این دو روش پرتودرمانی، می‌توان کانتور کردن گوش داخلی را جایگزین کانتور حلزون گوش نمود.

Background: Dosimetric accuracy in intensity-modulated radiation therapy (IMRT) is the main part of quality assurance program. Improper beam modeling of small fields by treatment planning system (TPS) can lead to inaccuracy in treatment delivery. This study aimed to evaluate of the dose delivery accuracy at small segments of IMRT technique using two-dimensional (2D) array as well as evaluate the capability of two TPSs algorithm in modeling of small fields. Methods: Irradiation were performed using 6 MV photon beam of Siemens Artiste linear accelerator. Dosimetric behaviors of two dose calculation algorithms, namely, collapsed cone convolution/superposition (CCCS) and full scatter convolution (FSC) in small segments of IMRT plans were analyzed using a 2D diode array and gamma evaluation. Results: Comparisons of measurements against TPSs calculations showed that percentage difference of output factors of small fields were 2% and 15% for CCCS and FSC algorithm, respectively. Gamma analysis of calculated dose distributions by TPSs against those measured by 2D array showed that in passing criteria of 3 mm/3%, the mean pass rate for all segment sizes is higher than 95% except for segment sizes below 3 cm × 3 cm optimized by TiGRT TPS. Conclusions: High pass rate of gamma index (95%) achieved in planned small segments by Prowess relative to results obtained with TiGRT. This study showed that the accuracy of small field modeling differs between two dose calculation algorithms.

Background: MapCHECK2 is a two-dimensional diode arrays planar dosimetry verification system. Dosimetric results are evaluated with gamma index. This study aims to provide comprehensive information on the impact of various factors on the gamma index values of MapCHECK2, which is mostly used for IMRT dose verification. Methods: Seven fields were planned for 6 and 18 MV photons. The azimuthal angle is defined as any rotation of collimators or the MapCHECK2 around the central axis, which was varied from 5 to −5°. The gantry angle was changed from −8 to 8°. Isodose sampling resolution was studied in the range of 0.5 to 4 mm. The effects of additional buildup on gamma index in three cases were also assessed. Gamma test acceptance criteria were 3%/3 mm. Results: The change of azimuthal angle in 5° interval reduced gamma index value by about 9%. The results of putting buildups of various thicknesses on the MapCHECK2 surface showed that gamma index was generally improved in thicker buildup, especially for 18 MV. Changing the sampling resolution from 4 to 2 mm resulted in an increase in gamma index by about 3.7%. The deviation of the gantry in 8° intervals in either directions changed the gamma index only by about 1.6% for 6 MV and 2.1% for 18 MV. Conclusion: Among the studied parameters, the azimuthal angle is one of the most effective factors on gamma index value. The gantry angle deviation and sampling resolution are less effective on gamma index value reduction.

Background: In this study, a comparison was performed between various intensity-modulated radiation therapy (IMRT) techniques for treatment of frontal area tumors in order to achieve the optimal treatment technique considering absorbed dose to the eye lens. Methods: Treatment planning and contouring were performed with TiGRT software for 20 patients with frontal area tumors. Three techniques were compared to each other. Finally, by comparing the dose volume histograms, the average dose received by each organ was determined and the best method was selected. Findings: In all three techniques, isodose curve of 30% passed through the eye, but the important point was that the curves were shifted towards the bottom of the eye with increasing the number of fields. Conclusion: The dose in the second technique was less than the other techniques. In this technique, there are five fields, and the path of the field does not go through the eye directly.

Background: In laparoscopy of colorectal tumors, titanium clips are used to close the surgery site. For post-operation treatment with radiation, the clips might change the dose distribution. In this study, the effect of titanium clips in isodose distribution of 6- and 18-MV photons was evaluated. Methods: Laparoscopy clips were placed on a phantom with material close to soft tissue. Computed tomography (CT) scan images of this phantom were imported in planning software and the percentage depth dose (PDD) and profiles of the dose were obtained for 6- and 18-MV photons. Findings: Calculated PDD showed weakening and backscattering of the dose of radiation in the path after the clips. Dose changes for the regions after the clips had a maximum of 1.7% and 1.1% for 6- and 8-MV photons, respectively. The amount of backscattering was up to 0.4% and 0.7% for 6- and 18-MV photons, respectively. Conclusion: Presence of the titanium clips in the path of radiation changes the depth dose and profiles. The changes for of a single clip are minor. However, for few clips beside each other, the effect of radiation attenuation is not negligible.

Background: In the vicinity of some of radiation therapy centers, measured exposure may not agree with calculated values due to the skyshine phenomenon. The aim of this study was to determine a computational model to predict the dose of radiation skyshine via Monte Carlo simulations. Methods: The simulation of linear accelerator head, skyshine geometry, and skyshine dose calculation at several heights and for different roof thicknesses was done using Monte Carlo N-Particle eXtended (MCNPX) code. The simulation results were validated via measuring and then were compared with the Council on Radiation Protection-151 (NCRP151) model results. Findings: The results of dose distribution in skyshine simulated model for all thicknesses of roof and every height from ground level showed an increase in the dose up to about 10 meters distance from the isocenter and then a decrease by distance from the isocenter; while the dose in the NCRP151 model, continuously decreases by distance. In addition, the amount of dose in each point was around 50 times larger than the simulated values. Dose reduction in both methods was proportional to the inverse-square. Conclusion: The model developed in this study can be used to predict the skyshine dose when designing a radiotherapy facility. The developed model is superior to the NCRP151 model due to its ability to calculate the dose in every point, inside and outside of treatment room, to investigate the influence parameters such as ceiling thickness and height from ground level and to determine the point with maximum dose.

Background: The aim of this study was to assess the effects of fractionated radiotherapy (RT) on expression of urothelial tight junction protein (occluding) in patients under prostate radiotherapy. Finding a correlation between occludin expression and bladder dose for patients undergoing prostate conformal external radiotherapy was the second aim. Methods: Urine samples of 64 patients under prostate radiotherapy were collected before and at regular intervals during and 3 months after radiotherapy. Occludin expression analysis of the collected urine samples was performed using chemical methods. The effective uniform dose to bladder was derived from the individually produced dose treatment plan of the patients. Findings: There was a significant change in urine occludin level after initiation of the radiotherapy course compared to the baseline urine samples (P = 0.040). The threshold bladder dose that caused significant change in occludin level was 25.5 Gy (P = 0.046). This bladder dose was occurred after the 15th radiotherapy session. In addition, change in urine occludin level was compatible with frequency, urgency, and dysuria (P < 0.050). Conclusion: Significant change in occludin expression occurred during prostate radiotherapy. Our findings suggest that increase in occludin expression level of the bladder wall can be used as early markers of bladder complications for patients under prostate radiotherapy.

Background: Hodgkin lymphoma is one of the treatable malignant diseases. The incidence of secondary cancers, especially breast cancer, and cardiovascular diseases after radiotherapy doubles the importance of patient treatment plan. In this study, some comparisons were made between a variety of treatments by using photon energy of 6 and 18 Mv on the treated areas of neck and mediastinum. Methods: The contouring of all sensitive organs and treatment volumes were performed for 18 female patients with Hodgkin lymphoma involving neck and mediastinum, using TiGRT software. Then, comparison between different anterior-posterior (AP-PA) treatments with different weights of 6 and 18 Mv was done. Findings: Using 18-Mv photon with the same weight of the anterior and posterior than conventional 6-Mv photon caused 2-9% reduction in mean dose to breast, heart, and lungs. Although changing the normalization (isocenter) point from the center of tumor to sternal notch reduced the mean dose of the studied organs, 9-13% reduction in the mean dose of treatment volume did not meet the criterion (prescribed dose ± 105%). Conclusion: For women with Hodgkin lymphoma involving mediastinum and neck, using 18-Mv photon with the same weight of the anterior and posterior is more appropriate to meet the design criteria of treatment (coating suitable treatment volume of prescribed dose ± 105%). Changing isocenter point from the center of the tumor to sternal notch causes a more favorable result. The better uniformity of the dose distribution in treatment volume is achieved by using 18-Mv photon.

Background: In this study, a comparison between various types of radiotherapy treatment for parotid gland cancer was performed to achieve the optimal treatment technique. Methods: Treatment planning and countering performed with TiGRT software for 15 patents with parotid gland cancer. Six techniques were performed and compared. Finally, by comparing the dose volume histograms (DVH), average dose received by each organ was determined and the best method was introduced. Techniques were as: 1. an ipsilateral wedge pair technique using 6 MV photons; 2. a 3-field anteroposterior (AP) (wedged) posteroanterior (PA) (wedged) and lateral portal technique using 6 MV photons; 3. a mixed beam technique using 6 MV photons and 12 MeV electrons (1:4 weighting); 4. a mixed beam technique using 6 MV photons and 15 MeV electrons (1:4 weighting); 5: four 6 MV photon beams with different gantry angles; and 6. similar to fifth technique with an additional small ring around the tumor tissue. Findings: Intensity-modulated arc therapy (IMRT) techniques five and six delivered maximum dose to the target and minimum dose to organ at risks (OAR). Among 3-D conformal radiotherapy techniques (CRT), technique number two delivered more amount of dose to the target than techniques number three and four. The dose delivered to the contrary parotid gland was negligible for intensity-modulated arc therapy techniques. Conclusion: Intensity-modulated arc therapy techniques are most appropriate methods for treating cancer of the parotid gland and the sixth technique delivered better dose distribution in the tumor and healthy tissues. Second D conformal radiotherapy technique delivered higher average dose to the target.

Background: After the surgery, radiation therapy is the most important part of treating brain tumors. Thyroid cancer is the second most prevalent malignancy, as a result of radiation therapy of head and neck. Therefore, in whole-brain radiation therapy, determining the absorption dose of thyroid and the risk of secondary thyroid cancer is important. The aim of this study was to calculate the absorption dose of thyroid and the risk of secondary thyroid cancer in whole-brain radiation therapy. Methods: The study included 50 patients undergoing whole-brain radiation therapy, with a mean age of less than 30 years old, in Isfahan Milad Hospital, Iran, using the ONCOR accelerator and 6-MV photon. Thermoluminescence dosimeter (TLD) was used to determine the dose received by the thyroid. Then, to calculate the risk of secondary thyroid cancer, the method of calculating risk in Biological Effected of Ionizing Radiation Committee (BEIR VII) report and the suggested quantity of International Commission on Radiological Protection (ICRP), which means excessive relative risk (ERR), were used. Findings: The calculated mean absorbed dose was 1.976 ± 0.611 and 2.213 ± 1.041 cGy in women and men, respectively. The mean risk of secondary cancer of the thyroid 3, 5, 10, 15 and 20 years after whole-brain radiation therapy was 4.601 ± 1.614, 1.559 ± 0.595, 0.176 ± 0.063, 0.050 ± 0.018, and 0.022 ± 0.009, in women and 3.253 ± 1.721, 1.150 ± 0.516, 0.125 ± 0.066, 0.035 ± 0.019, 0.016 ± 0.008 in men, respectively. The absorption dose of thyroid was not related to age (P = 0.743). Conclusion: The risk of secondary cancer of the thyroid is associated with sex and is 1.4 times more in women. In addition, by increasing the age after radiation the mean risk of induced cancer had a reducing behavior.

Radiotherapy is one of the treatment options for locally advanced prostate cancer; however, with standard radiation doses, it is not always very effective. One of the strategies to improve the efficiency of radiotherapy is increasing the dose. In this study, to increase tumor local control rates, a new radiotherapy method, known as dose painting (DP), was investigated. To compare 3-dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) plans with DP for prostate cancer. Twenty-four consecutive patients with locally advanced prostate cancer who underwent an multiparametric-magnetic resonance imaging (MP-MRI) (T2w, diffusion weighted image, dynamic contrast enhancement, and MRS) scan before a diagnostic biopsy from September 2015 to April 2016 were invited to take part in this study. The tumor local control probability (TCP) values for 3D-CRT, IMRT, and DP techniques were 45, 56, and 77%, respectively. The DP technique had a 37.5 and 71% higher TCP than IMRT and 3D-CRT, and these differences were statistically significant (P = 0.001). The mean normal tissue complication probability (NTCP) values of the organ at risks for 3D-CRT, IMRT, and DP showed that there were statistically significant differences among them in three plans (P = 0.01). DP by contours using MP-MRI is technically feasible. This study evaluated biological modeling based on both MP-MRI defined subvolumes and pathologically defined subvolumes. The MP-MRI-guided DP results in better TCP/NTCP than 3D-CRT and IMRT.

مقدمه: بیماری هوچکین (Hodgkin’s disease) نوع خاصی از لنفوم یا سرطان می‌باشد که با رشد غیر طبیعی سلول‌ها در دستگاه لنفاوی همراه است. این مطالعه، جهت بررسی توزیع دز در طرح درمان‌های مختلف در زنان مبتلا به بیماری هوچکین انجام شد. به علت وجود اندام‌های حساس در این ناحیه و بروز بیماری‌ها و سرطان‌های ثانویه بعد از رادیوتراپی، بررسی طرح درمان‌های مختلف در این ناحیه حایز اهمیت است. روش‌ها: از اطلاعات Computed tomography scan (CT scan) 18 بیمار زن مبتلا به بیماری هوچکین با درگیری مدیاستن استفاده شد. در مرحله‌ی بعد، توسط نرم‌افزار طراحی درمان بیمارستان سیدالشهدای (ع) اصفهان، کانتورینگ تمام اندام‌های حساس داخل فیلد و حجم درمانی انجام گرفت. سپس، مقایسه‌هایی بین درمان رایج موازی- مخالف با انرژی 6 و 18 مگاولتاژ و تکنیک چهار میدان با وزن‌های مختلف صورت گرفت. یافته‌ها: ماکزیمم دز رسیده به پستان در تکنیک چهار فیلدی نسبت به تکنیک رایج دو فیلد مقابل، 33 درصد کاهش یافت. از طرفی، تکنیک چهار فیلدی دز میانگین رسیده به پستان را حدود 3 برابر افزایش می‌دهد. متوسط دز میانگین رسیده به حجم درمانی در تکنیک‌های دو فیلدی، 102-100 درصد و در تکنیک چهار فیلدی، 5/99 درصد بود. نتیجه‌گیری: برای زنان مبتلا به بیماری هوچکین با درگیری مدیاستن، استفاده از تکنیک دو فیلدی با فوتون 18 مگاولتاژ با وزن 5/1 از قدام و 5/0 از خلف، نسبت به فوتون 6 مگاولتاژ نتایج قابل قبول‌تری دارد و استفاده از تکنیک چهار فیلدی، منجر به کاهش V20 برای کل ریه و کاهش دز میانگین رسیده به مری،آئورت، نخاع و نیز V30 قلب می‌گردد.

Background: Radiation therapy is used to treat and control advanced ovarian cancer with spread to abdominal peritoneum. In this study, a comparison between various plans of radiation therapy within the abdomen and pelvis was performed in order to achieve an effective treatment response. Methods: Contouring and planning of 20 patients with CT-scan of the abdomen and pelvis were done by TiGRT software. In order to compare the different types of treatment planning for the selected site, some common criteria in radiotherapy and H-index were used. Findings: Among these methods, it was found that the two methods of anterior-posterior and lateral with 18 MV energy and same weight have same level of protection of organs at risk. While the tangent method do not produce a reasonable result. Moreover in anterior- posterior method can be shown that the changing in energy and beam weight give a various results from PTV covering and dose uniformity aspects. Conclusion: Among the various treatment planning were seen that AP/PA with AP = 6MV energy and weight 1, PA = 18 MV and weight 1.5, for covering whole abdomen give a better results.

The most prevalent type of soft tissue sarcoma is undifferentiated pleomorphic sarcoma (UPS) or previously known as malignant fibrous histiocytoma. It accounts over 20% of all soft tissue sarcomas and occurs most frequently in the extremities, trunk, and retroperitoneum. However, it has been rarely observed in the digestive system. Pancreas sarcoma represents less than 1% of all pancreatic tumors, and primary UPS of the pancreas is even rarer. It exhibits high recurrence and poor prognosis. In this case, a 72-year-old woman with a UPS tumor which was located in the pancreas head and neck without adhesion to the retroperitoneum will be discussed.

Clinical Practice for Radiation Therapy in Breast Cancer

مقدمه: پرسش‌نامه‌ی 29EORTC QLQ-CR توسط کارگروه کیفیت زندگی EORTC (European organisation for research and treatment of cancer) به طور اختصاصی برای بررسی کیفیت زندگی بیماران مبتلا به سرطان کولورکتال (CRC یا Colorectal cancer) طراحی شده است. مطالعه‌ی حاضر با هدف اعتبارسازی زبان شناختی پرسش‌نامه‌ی 29QLQ-CR (29Quality of life questionnaires-colorectal) و تعیین خصوصیات سایکومتریک آن در جامعه‌ی ایرانی فارسی زبان انجام شد.. روش‌ها: این مطالعه از نوع اعتباریابی زبانشناختی بود. ترجمه‌ی پرسش‌نامه‌ی 29QLQ-CR طبق روش استاندارد Forward-backward translation انجام شد. پس از انجام مطالعه‌ی راهنما در 15 بیمار، پرسش‌نامه‌ی 29QLQ-CR به همراه پرسش‌نامه‌های 30 EORTC QLQ-C و فهرست علایم ام. دی. اندرسون (MDASI یا M.D. Anderson symptom inventory) توسط 100 بیمار مبتلا به CRC تکمیل شد و خصوصیات سایکومتریک آن مورد بررسی قرار گرفت. یافته‌ها: تعداد 100 بیمار مبتلا به CRC در مطالعه‌ی اصلی شرکت کردند؛ میانگین سنی آن‌ها 9/13 ± 4/60 سال بود و 64 درصد آنان مذکر بودند. Cronbach's alpha کل پرسش‌نامه‌ی 29QLQ-CR برابر با 89/0 و Cronbach's alpha ابعاد پرسش‌نامه از 65/0 تا 98/0 متغیر بود. در تمامی شاخص‌های چند موردی، ضریب همبستگی هر مورد با شاخص مربوط بیش از 4/0 (9/0-7/0) بود. بین شاخص‌های عملکردی پرسش‌نامه‌ی 30QLQ-CR و 11 شاخص پرسش‌نامه‌ی 29QLQ-CR رابطه‌ی متوسط تا قوی و معنی‌داری وجود داشت (667/0 ≥ r ≥ 301/0). همچنین در بسیاری از موارد، بین شاخص‌های پرسش‌نامه‌ی 29QLQ-CR و نمره‌ی شدت علایم و نمره‌ی اثر علایم بر کیفیت زندگی از پرسش‌نامه‌ی MDASI رابطه وجود داشت (585/0 ≥ r ≥ 265/0). نتیجه‌گیری: طبق نتایج مطالعه‌ی حاضر، خصوصیات سایکومتریک نسخه‌ی فارسی ضمیمه‌ی 29EORTC QLQ-CR در جامعه‌ی ایرانی قابل قبول است و این پرسش‌نامه می‌تواند در مطالعات آینده جهت بررسی دقیق‌تر کیفیت زندگی بیماران مبتلا به CRC مورد استفاده قرار گیرد.

Background: In radiotherapy, the presence of metallic implants affects the dose distribution, depending on beam energy and type, size, material and position of the implant. In this study, the effect of spinal implants on dose distribution was evaluated by Monte Carlo simulation. Methods: Oncor accelerator and water phantom, Plexiglas phantom containing spine and Plexiglas phantom containing spine and rod implants were simulated using BEAMnrc and DOSXYZnrc user codes and were validated. The effect of the implant presence, its size material, and location on dose distribution was investigated. Findings: Comparison of dose distributions with and without implants showed an increase of 5.5% in dose up to 4 mm from metal surface, due to the back scattering of electrons. Maximum attenuation in titanium rods was 9%. When the rods were positioned closer to each other, an increase in attenuation was observed. However, dose in spine was increased, when the distance between rods and spine was reduced. Rods with smaller cross section had less effect on dose. Attenuation in vitallium and stainless steel implants were 2 times greater than titanium implants. Conclusion: Depending on the location of implant with respect to spine, dose perturbation due to implants can either increase or decrease the dose in spine. The effect of size and material of implant was more important when spine was located under the implant. Generally, the effect of spinal implant on dose distribution is a function of size, material and position of the implant. Therefore, it is recommended to evaluate the dose distribution for such patients individually.

Radiotherapy plays an essential role in the management of breast cancer. Three-dimensional conformal radiation therapy (3D-CRT) is applied based on 3D image information of anatomy of patients. In 3D-CRT for breast cancer one of the common techniques is tangential technique. In this project, various parameters of tangential and supraclavicular fields are optimized. This project has been done on computed tomography images of 100 patients in Isfahan Milad Hospital. All patients have been simulated and all the important organs have been contoured by radiation oncologist. Two techniques in supraclavicular region are evaluated including: 1-A single field (Anterior Posterior [AP]) with a dose of 200 cGy per fraction with 6 MV energy. This is a common technique. 2-Two parallel opposed fields (AP-Posterior Anterior [PA]). The dose of AP was 150 cGy with 6 MV energy and PA 50 cGy with 18 MV. In the second part of the project, the tangential fields has been optimized with change of normalization point in five points: (1) Isocenter (Confluence of rotation gantry axis and collimator axis) (2) Middle of thickest part of breast or middle of inter field distance (IFD) (3) Border between the lung and chest wall (4) Physician′s choice (5) Between IFD and isocenter. Dose distributions have been compared for all patients in different methods of supraclavicular and tangential field. In parallel opposed fields average lung dose was 4% more than a single field and the maximum received heart dose was 21.5% less than a single field. The average dose of planning tumor volume (PTV) in method 2 is 2% more than method 1. In general AP-PA method because of a better coverage of PTV is suggested. In optimization of the tangential field all methods have similar coverage of PTV. Each method has spatial advantages and disadvantages. If it is important for the physician to reduce the dose received by the lung and heart, fifth method is suggested since in this method average and maximum received dose to heart and lung have been reduced few percent in comparison to other methods. If a better coverage of PTV is important for the physician second method can be an optimized method. In this method, average and maximum received dose to PTV have been increased few percent in comparisons of physician′s choice method and three other methods. In optimizing of supraclavicular field AP-PA method due to better coverage of PTV is suggested. In optimizing of tangential all methods are similar. Each method has special advantages and disadvantages. The physicians can change the depth of the normalization point in the breast to get the desired average dose.

The Monte Carlo method is the most accurate method for simulation of radiation therapy equipment. The linear accelerators (linac) are currently the most widely used machines in radiation therapy centers. In this work, a Monte Carlo modeling of the Siemens ONCOR linear accelerator in 6 MV and 18 MV beams was performed. The results of simulation were validated by measurements in water by ionization chamber and extended dose range (EDR2) film in solid water. The linac′s X-ray particular are so sensitive to the properties of primary electron beam. Square field size of 10 cm Χ 10 cm produced by the jaws was compared with ionization chamber and film measurements. Head simulation was performed with BEAMnrc and dose calculation with DOSXYZnrc for film measurements and 3ddose file produced by DOSXYZnrc analyzed used homemade MATLAB program. At 6 MV, the agreement between dose calculated by Monte Carlo modeling and direct measurement was obtained to the least restrictive of 1%, even in the build-up region. At 18 MV, the agreement was obtained 1%, except for in the build-up region. In the build-up region, the difference was 1% at 6 MV and 2% at 18 MV. The mean difference between measurements and Monte Carlo simulation is very small in both of ONCOR X-ray energy. The results are highly accurate and can be used for many applications such as patient dose calculation in treatment planning and in studies that model this linac with small field size like intensity-modulated radiation therapy technique.

Introduction Intensity Modulated Radiation Therapy (IMRT) has made a significant progress in radiation therapy centers in recent years. In this method, each radiation beam is divided into many subfields that create a field with a modulated intensity. Considering the complexity of this method, the quality control for IMRT is a topic of interest for researchers. This article is about the various steps of planning and quality control of Siemens linear accelerators for IMRT, using film dosimetry. This article in addition to review of the techniques, discusses the details of experiments and possible sources of errors which are not mentioned in the protocols and other references. Materials and Methods This project was carried out in Isfahan Milad hospital which has two Siemens ONCOR linear accelerators. Both accelerators are equipped with Multi-Leaf Collimators (MLC) which enables us to perform IMRT delivery in the step-and-shoot method. The quality control consists of various experiments related to the sections of radiation therapy. In these experiments, the accuracy of some components such as treatment planning system, imaging device (CT), MLC, control system of accelerator, and stability of the output are evaluated. The dose verification is performed using film dosimetry method. The films were KODAK-EDR2, which were calibrated before the experiments. One of the important steps is the comparison of the calculated dose with planning system and the measured dose in experiments. Results The results of the experiments in various steps have been acceptable according to the standard protocols. The calibration of MLC and evaluation of the leakage through the leaves of MLC was performed by using the film dosimetry and visual check. In comparison with calculated and measured dose, more that 80% of the points have to be in agreement within 3% of the value. In our experiments, between 85 and 90% of the points had such an agreement with IMRT delivery. Conclusion The EDR2 films are suitable for quality control of IMRT. According to complexity of the quality control for IMRT, the physicists of each center have to develop specific guidelines according to their equipments and limitations. An accurate treatment planning system with capability of inverse planning is an essential need for IMRT. The result of the planning system has to be compared with experiments in various situations.

Background: Glioblastoma (GBM) is the most common and invasive form of primary malignant brain tumors, with a survival rate of about 1 year. Transforming growth factor-β1 (TGF- β 1) plays a very important role in tissue homeostasis and cancers. It seems that polymorphism of T29C (L10P, rs1982073, or rs1800470), which has been studied in various cancers such as breast and colon, creates the significant differences plays an important role in GBM prognosis and treatment. In this study, we evaluated the effect of T29C (rs1982073) polymorphism of TGF-β1 gene in GBM. Materials and Methods: This study was conducted on 100 cases of GBM including 47 paraffin-embedded brain tissue samples and 53 blood samples from another 53 GBM patients, who was under therapy, and 150 were controls. The TGF-β rs1982073 single-nucleotide polymorphism (SNP) was identified by the NCBI and genotyping was performed by high-resolution melt (HRM) assay. Melt curves from HRM which suspected to SNP were selected and subjected to direct sequencing. Finally, the collected data were entered into the SPSS software (Version. 20) and mean ± standard deviation or n (%) was used to show the data. Results: The mean age in GBM group was 51.63 ± 13.27 years. Accordingly, the two groups were matched in terms of age and gender (P > 0.05). The frequency of GG genotype was significantly higher in GBM patients. In contrast, although the frequency of AG genotype was higher in GBM group, it was not statistically significant. Furthermore, the presence of G allele was significantly more frequent than A allele in GBM patients. Conclusion: Findings of the present study supports that the Pro10Leu, rs1982073, or rs1800470 SNP in TGF- β 1 is found to be expressed significantly more in GBM patients as it was found in breast cancer.

Background: In radiation therapy, computed tomography (CT) simulation is used for treatment planning to define the location of tumor. Magnetic resonance imaging (MRI)-CT image fusion leads to more efficient tumor contouring. This work tried to identify the practical issues for the combination of CT and MRI images in real clinical cases. The effect of various factors is evaluated on image fusion quality. Materials and Methods: In this study, the data of thirty patients with brain tumors were used for image fusion. The effect of several parameters on possibility and quality of image fusion was evaluated. These parameters include angles of the patient's head on the bed, slices thickness, slice gap, and height of the patient's head. Results: According to the results, the first dominating factor on quality of image fusion was the difference slice gap between CT and MRI images (cor = 0.86, P < 0.005) and second factor was the angle between CT and MRI slice in the sagittal plane (cor = 0.75, P < 0.005). In 20% of patients, this angle was more than 28° and image fusion was not efficient. In 17% of patients, difference slice gap in CT and MRI was> 4 cm and image fusion quality was

Background: One of the standard equipment in medical linear accelerators is multi-leaf collimators (MLCs); which is used as a replacement for lead shielding. MLC's advantages are a reduction of the treatment time, the simplicity of treatment, and better dose distribution. The main disadvantage of MLC is the radiation leakages from the edges and between the leaves. The purpose of this study was to determine the effect of various treatment parameters in the magnitude of MLC leakage in linear accelerators. Materials and Methods: This project was performed with ONCOR Siemens linear accelerators. The amount of radiation leakage was determined by film dosimetry method. The films were Kodak-extended dose range-2, and the beams were 6 MV and 18 MV photons. In another part of the experiment, the fluctuation of the leakage was measured at various depths and fields. Results: The amount of leakage was generally up to 1.5 ± 0.2% for both energies. The results showed that the level of the leakage and the amount of dose fluctuation depends on the field size and depth of measurement. The amount of the leakage fluctuations in all energies was decreased with increasing of field size. The variation of the leakage versus field size was similar to the inverse of scattering collimator factor. Conclusions: The amount of leakage was more for 18 MV compare to 6 MV The percentage of the leakage for both energies is less than the 5% value which is recommended by protocols. The fluctuation of the MLC leakage reduced by increasing the field size and depth.

Background: The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans, both pretreatment and in vivo. The aim of this study is to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in vivo as well. Materials and Methods: Dose distributions were reconstructed from EPID images using a 2D EPID dosimetry algorithm inside a homogenous slab phantom for a simple 10 × 10 cm2 box technique, 3D conformal (prostate, head-and-neck, and lung), and intensity-modulated radiation therapy (IMRT) prostate plans inside an anthropomorphic (Alderson) phantom and in the patients (one fraction in vivo) for 3D conformal plans (prostate, head-and-neck and lung). Results: The planned and EPID dose difference at the isocenter, on an average, was 1.7% for pretreatment verification and less than 3% for all in vivo plans, except for head-and-neck, which was 3.6%. The mean γ values for a seven-field prostate IMRT plan delivered to the Alderson phantom varied from 0.28 to 0.65. For 3D conformal plans applied for the Alderson phantom, all γ1% values were within the tolerance level for all plans and in both anteroposterior and posteroanterior (AP-PA) beams. Conclusion: The 2D EPID-based dosimetry algorithm provides an accurate method to verify the dose of a simple 10 × 10 cm2 field, in two dimensions, inside a homogenous slab phantom and an IMRT prostate plan, as well as in 3D conformal plans (prostate, head-and-neck, and lung plans) applied using an anthropomorphic phantom and in vivo. However, further investigation to improve the 2D EPID dosimetry algorithm for a head-and-neck case, is necessary.