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Purpose: Accurate knowledge about surface dose distribution is a critical issue in skin irradiation. This study was conducted to investigate the surface dose using the Eclipse Treatment Planning System (TPS) calculation and GAF chromic film measurement for breast cancer treatment. Materials and Methods: An inhomogeneous chest phantom was used in the present study. Irradiations were done with a 6 MV energy beam of a linear accelerator (Varian 2100C/D). TPS calculations and film measurements were compared for surface dose estimations. Results: The average difference between film measurements and TPS calculations was 7.1%. Surface doses were lower in TPS calculations in comparison with film measurements. Conclusion: TPS plays a significant role in radiotherapy. However, they have many errors in measuring surface doses. Because of the inaccuracy of the majority of treatment planning systems in calculating the surface dose, the need for practical measurements is essential.

Total body irradiation (TBI) is an external radiotherapy technique. Its aim is to deliver a therapeutic dose uniformly within ± 10% of the absorbed dose to the prescription point. In the present study, the TBI technique was implemented in anterior/posterior (AP/PA), and bilateral geometry with photons from a 6 $$\mathrm{MV}$$ and 18 $$\mathrm{MV}$$ accelerator. The TBI technique was implemented on an Alderson Rando phantom at 312 $$\mathrm{cm}$$ source surface distance. During bilateral fraction, rice bags were applied as tissue compensators. To reduce the lung’s absorbed dose to the acceptance level, in AP/PA geometry lung blocks made of Cerrobend were used. The required monitor unit (MU) for each fraction was calculated regarding depending on the prescribed dose and beam output. Gafchromic EBT3 films were used for dosimetry between the phantom layers in eight selected points. It is demonstrated that dose uniformity for AP/PA geometry with 6 $$\mathrm{MV}$$ and 18 $$\mathrm{MV}$$ photons was within ± 10%. In contrast, for the bilateral geometry the dose uniformity was not acceptable for both studied energies; However, the results for 18 $$\mathrm{MV}$$ were better than those for 6 $$\mathrm{MV}$$ . Dose accuracy for all measurements was within ± 5 of the prescribed dose. The absorbed dose to the lungs was successfully reduced using the lung blocks. By combining different therapeutic geometries and energies over six fractions, the results of uniformity and accuracy of dose delivery could be improved. It is concluded that the introduced TBI method achieved good dose accuracy and acceptable dose uniformity. Lungs absorbed dose was lower than 10 $$\mathrm{Gy}$$ using the lungs blocks. Based on these results, the TBI technique can now be implemented in radiotherapy at Tehran’s Imam Hospital. The approach developed in the present study can be used and adapted to match with the conditions at other hospitals.

Low-grade gliomas are responsible for approximately 15% of all adult primary intracranial tumors. The treatment strategy is still controversial. In this study, we aimed to evaluate the treatment outcomes and predictive factors for local control and overall survival in this population. We have reviewed 50 cases of adult patients with low-grade gliomas diagnosed from 2009 to 2019. All patients underwent surgical intervention followed by post-operative radiotherapy, and some also received chemotherapy. With a median follow-up of 21 months for surviving patients, the 2-year overall and progression-free survival rates were 83 and 82%, respectively. Only the different radiotherapy methods showed independent prognostic values for overall survival and disease-free survival of our patients. In this study, we found that only type of radiotherapy (2D vs. 3D) has prognostic value for 2-year PFS and overall survival rates. There need to be further efforts to optimize radiotherapy techniques and to integrate new therapeutic modalities.

Introduction: Glioblastoma is the most common intrinsic malignant brain tumor in adults and it has a dismal prognosis. This study aims to evaluate the impact of the TERTp mutation as an independent prognostic biomarker in glioblastoma patients. Materials and Methods: Newly diagnosed cases of glioblastoma who have undergone surgical treatment were enrolled from 2018 to 2020. All patients undergone maximal safe resection accompanied by adjuvant therapy. The preoperative clinical and paraclinical data were documented and then regularly during the follow up. The Genetic profiling of the tumors included IDH-1 and IDH-2 mutation, MGMT promotor methylation, EGFR gene amplification and TERTp mutation. Results: The mean age of patients under study was 42.01±11.36 years; 41 patients were male (57.70%). The overall mean OS and PFS were 14.45±5.13 months and 10.66±4.87 months. The biomarker assessment showed IDH1 and TERTp mutation in 56.34% and 30.98%. The preoperative KPS and EOR>95% were related with OS and PFS. The TERTp mutant group had a lower OS and PFS than TERTp wildtype group (P=0.00). In the TERT mutant group, those with concomitant IDH1 wildtype tumor had significantly shorter OS and PFS. In multivariate analysis, EOR>95%, preoperative KPS≥80, IDH-1 mutation and TERTp-wildtype were predictive of longer PFS. The OS was determined by IDH-1 mutation, TERTp mutation and preoperative KPS. Conclusion: this study reveals that TERTp mutant glioblastoma patients have shorter OS & PFS than the TERTp-wildtype independently. The worst prognostic biomarker constellation in this study was TERTp mutation and concomitant IDH1 wildtype tumors.

Background: Dose distribution can be obtained from total energy released per unit mass (TERMA) and inhomogeneous energy deposition kernel (EDK) convolution. Since inhomogeneous EDK data is location-dependent, it is calculated by employing the density scaling method rather than Monte Carlo based user code EDKnrc. Objective: The present study aimed at investigating EDK scaling formula accuracy in the presence of lung and bone inhomogeneities.Material and Methods: In this theoretical-practical study, six EDKs datasets with lung and bone inhomogeneity in different radii were generated using EDKnrc user code and density scaling formula. Then the scaling method data and corresponding EDKnrc-generated ones were compared to enhance the calculations, and some correction factors for error reduction were also derived to create more consistency between these data. Results: The study has shown that the errors in the theoretical method for calculating inhomogeneous EDKs were significantly reduced based on the attenuation coefficient and ραrel parameter, with α equal to 1.2 and 0.8 for bone and lung voxels, respectively. Conclusion: Although the density scaling method has acceptable accuracy, the error values are significant at the location of lung or bone voxels. By using the mentioned correction factors, the calculation inaccuracy of heterogeneous EDKs can be reduced down to 5%. However, the lung heterogeneity results corrected by the method are not as good as the bone cases.

Purpose:Total body irradiation (TBI) is an external beam radiation therapy in which large field size and extended source skin distances (SSDs) are applied to deliver a therapeutic dose to the whole body. As measurements in such situations are not common and have more uncertainties in comparison to standard dosimetry situations, it is more precise if calculated beam data can be used instead of measurements taken under TBI situations. The purpose of this study is to compare calculated beam data [percentage depth dose (PDD) and dose rate] with those obtained from simulated treatment measurements.Materials and methods:PDD and dose rates were measured for the 6- and 18-MV photon beams under TBI and standard conditions using 9,000 cm3 water phantom and ion chambers (Markus and Farmer). The results were then compared with the calculated PDD and dose rate data. The beam flatness was also measured under TBI and standard conditions for both 6- and 18-MV photon beams, and the results were then compared.Results:A comparison of the measurement and calculated beam data shows that the difference between calculated and measured PDD values is −6·97 and −4·14% for the 6- and 18-MV photon beams, respectively. The ratio of calculated to measured dose rate was 1·09 and 1·02 for the 6- and 18-MV photon beams, respectively. The beam flatness under TBI conditions was 4·59% for 6-MV and 5·37% for 18-MV photon beam, whereas under standard conditions, these values were 1·50 and 1·98% for 6- and 18-MV radiation beams, respectively.Findings:According to the results, due to a high error level in dose rate and PDD calculations, these parameters must be directly measured under TBI conditions; however, regarding the obtained results, direct measurement is not necessary for the 18-MV photon beam.

Purpose:The aim of this study was to produce a low-cost anatomical model of adult male including lower limbs to evaluate the three-dimensional dose distribution for dosimetry measurements, especially in total body irradiation (TBI) and total skin electron therapy (TSET).Materials and methods:Computed tomography (CT) scan images of the atomic energy organisation RANDO phantom and lower limb CT scan images of 20 healthy persons were averaged. Selections of different body tissues substitute materials and phantom validation were performed according to previous studies worked on construction of radiation therapy phantoms.Results:The dosimetry aspect of the selected substitute materials from all considered methods showed that they were in good agreement with real human tissue, especially bone, with a percentage error of 0·5%. The results show that the electron densities obtained from the linear attenuation coefficient (reDLAC) for the tissue equivalent material used in the phantom is a better option for validation.Conclusions:This validated phantom has numerous advantages over the origin type of RANDO phantom. Therefore, using it in TBI and TSET dosimetry is recommendable.

Background: Cyclo-oxygenase-2 (COX-2), an enzyme induced in pathological states, mediates the production of prostaglandins. Celecoxib as a selective COX-2 inhibitor may affect the outcome of treatments in several cancer types. Objectives: We conducted a randomized controlled double-blind clinical trial to evaluate the toxicity and efficacy of celecoxib administered concurrently with chemoradiation in locally advanced head and neck carcinomas. Methods: Patients with locally advanced head and neck carcinoma referred for definitive chemoradiation were eligible to enter the study. Celecoxib (100mg, qid, oral) or placebo was administered all over the chemoradiation period. Results: Totally, 122 patients were enrolled. Patients in the celecoxib group had a longer median time to onset of grade 2 mucositis (56 days vs. 28 days, P < 0.001) and a lower rate of grade 3 mucositis (1.6% vs. 21.3%, P = 0.001). The 4-year progression-free survival was significantly higher in the celecoxib group (P = 0.0013). Conclusions: This study revealed that utilizing celecoxib may lead to better tumor local control and delayed and reduced mucosal side effects of chemoradiation.

Background Awake Craniotomy (AC) is considered to achieve maximal safe resection of language eloquent gliomas. Impact of AC on the psychological status of patients (mainly anxiety, and post-traumatic stress disorder: PTSD) is a potential concern. Despite the studies reporting the early postoperative patient's perception after AC, this study has been performed to quantitatively evaluate the long term influence of AC on the level of anxiety/depression after surgery. Methods Patients who underwent AC for suspected language eloquent high-grade glioma were enrolled in this study. The anxiety, depression and PTSD of the patients were evaluated via hospital anxiety and depression scale (HADS) one week before and 1 and 6 months after the operation. PTSD symptoms were assessed according to the DSM-V checklist and confirmed by a structured clinical interview for DSM-V. Results Twenty-eight patients (22 men, 6 women) with the mean age of 39.2 years were enrolled. The mean preoperative depressive and anxiety score was 4.9±5.9 and 7.7±5.8 respectively. One month after surgery they were 6±4.9 and 7.4±6.2 and at 6 months' follow-up 5.5±5.1 and 5.4±4.2 respectively. There was no statistically significant trend for alterations of the anxiety/depression levels before and after surgery. Female patients, those suspected to have glioblastoma and patients presenting with speech disturbance had remarkably higher preoperative anxiety levels. Three patients had PTSD symptoms 3 months after AC while at 6 months there was no indication of PTSD. The decremental trend of PTSD score within 6 months was statistically significant. Conclusions Judicious application of AC is not associated with an escalation of the anxiety/depression level among the patients. Even patients with high preoperative anxiety levels could be managed with AC without severe psychological deterioration.

Background: Online Monte Carlo (MC) treatment planning is very crucial to increase the precision of intraoperative radiotherapy (IORT). However, the performance of MC methods depends on the geometries and energies used for the problem under study. Objective: This study aimed to compare the performance of MC N-Particle Transport Code version 4c (MCNP4c) and Electron Gamma Shower, National Research Council/easy particle propagation (EGSnrc/Epp) MC codes using similar geometry of an INTRABEAM® system.Material and Methods: This simulation study was done by increasing the number of particles and compared the performance of MCNP4c and EGSnrc/Epp simulations using an INTRABEAM® system with 1.5 and 5 cm diameter spherical applicators. A comparison of these two codes was done using simulation time, statistical uncertainty, and relative depth-dose values obtained after doing the simulation by each MC code. Results: The statistical uncertainties for the MCNP4c and EGSnrc/Epp MC codes were below 2% and 0.5%, respectively. 1e9 particles were simulated in 117.89 hours using MCNP4c but a much greater number of particles (5e10 particles) were simulated in a shorter time of 90.26 hours using EGSnrc/Epp MC code. No significant deviations were found in the calculated relative depth-dose values for both in the presence and absence of an air gap between MCNP4c and EGSnrc/Epp MC codes. Nevertheless, the EGSnrc/Epp MC code was found to be speedier and more efficient to achieve accurate statistical precision than MCNP4c. Conclusion: Therefore, in all comparisons criteria used, EGSnrc/Epp MC code is much better than MCNP4c MC code for simulating an INTRABEAM® system. Background:Online Monte Carlo (MC) treatment planning is very crucial to increase the precision of intraoperative radiotherapy (IORT). However, the performance of MC methods depends on the geometries and energies used for the problem under study. Objective: This study aimed to compare the performance of MC N-Particle Transport Code version 4c (MCNP4c) and Electron Gamma Shower, National Research Council/easy particle propagation (EGSnrc/Epp) MC codes using similar geometry of an INTRABEAM® system. Material and Methods: This simulation study was done by increasing the number of particles and compared the performance of MCNP4c and EGSnrc/Epp simulations using an INTRABEAM® system with 1.5 and 5 cm diameter spherical applicators. A comparison of these two codes was done using simulation time, statistical uncertainty, and relative depth-dose values obtained after doing the simulation by each MC code. Results: The statistical uncertainties for the MCNP4c and EGSnrc/Epp MC codes were below 2% and 0.5%, respectively. 1e9 particles were simulated in 117.89 hours using MCNP4c but a much greater number of particles (5e10 particles) were simulated in a shorter time of 90.26 hours using EGSnrc/Epp MC code. No significant deviations were found in the calculated relative depth-dose values for both in the presence and absence of an air gap between MCNP4c and EGSnrc/Epp MC codes. Nevertheless, the EGSnrc/Epp MC code was found to be speedier and more efficient to achieve accurate statistical precision than MCNP4c. Conclusion: Therefore, in all comparisons criteria used, EGSnrc/Epp MC code is much better than MCNP4c MC code for simulating an INTRABEAM® system.

Using the 50 kV INTRABEAM

Total body irradiation (TBI) is an external radiotherapy technique. Its aim is to deliver a therapeutic dose uniformly within ± 10% of the absorbed dose to the prescription point. In the present study, the TBI technique was implemented in anterior/posterior (AP/PA), and bilateral geometry with photons from a 6 [Formula: see text] and 18 [Formula: see text] accelerator. The TBI technique was implemented on an Alderson Rando phantom at 312 [Formula: see text] source surface distance. During bilateral fraction, rice bags were applied as tissue compensators. To reduce the lung's absorbed dose to the acceptance level, in AP/PA geometry lung blocks made of Cerrobend were used. The required monitor unit (MU) for each fraction was calculated regarding depending on the prescribed dose and beam output. Gafchromic EBT

Normal-pressure hydrocephalus (NPH) has rarely been reported to be associated with trigeminal neuralgia (TN). We report a case of NPH with trigeminal neuralgia, whose symptoms completely resolved after endoscopic third ventriculostomy. We will notify another surgical management of trigeminal neuralgia, considering the different pathophysiology of TN and a brief review of the literature.

Purpose In previous studies, methylthymol-blue and benzoic acid have been introduced as a diffuser limiter and sensitivity enhancer in the gel dosimeter composition, respectively. This work focused on analyzing a formulation of the Fricke gel dosimeter consisting of methylthymol-blue and benzoic acid through magnetic resonance imaging. Methods The gel dosimeter samples were irradiated using 6, 10, and 15 MV photons with different levels of doses and read using a 1.5 T scanner in order to evaluate the dose–response sensitivity and to study the effect of benzoic acid concentration, diffusion coefficient and temperature and to determine the temporal stability of the gel dosimeter. Results Inspection of radiological properties revealed that this gel dosimeter can be considered as a tissue equivalent medium. Within the dose range 0 to 1000 cGy, the R1 sensitivity and R2 sensitivity of the gel dosimeter equaled 0.058 ± 0.003 and 0.092 ± 0.004 s−1Gy−1, respectively. The diffusion coefficient was less than 0.85 ± 0.02mm2h−1 for doses higher than 200 cGy. In addition, by changing the temperature from 15C to 25, the R1 sensitivity and R2 sensitivity decreased about 5 and 11%, respectively. Further, no significant energy and dose rate dependence were observed over photon energies of 6, 10, and 15 MV and over the range 65 to 525 cGy min−1. Conclusions Based on our observation, the ferrous benzoic acid methylthymol-blue gel dosimeter can be suggested to measure the dose distribution. Further analysis is required to clarify its performance in clinical situations.

Background and purpose.Accurate volume delineation plays an essential role in radiotherapy. Contouring is a potential source of uncertainties in radiotherapy treatment planning that could affect treatment outcomes. Therefore, reducing the degree of contouring uncertainties is crucial. The role of utilized imaging modality in the organ delineation uncertainties has been investigated. This systematic review explores the influential factors on inter-and intra-observer uncertainties of target volume and organs at risk (OARs) delineation focusing on the used imaging modality for these uncertainties reduction and the reported subsequent histopathology and follow-up assessment.Methods and materials.An inclusive search strategy has been conducted to query the available online databases (Scopus, Google Scholar, PubMed, and Medline). 'Organ at risk', 'target', 'delineation', 'uncertainties', 'radiotherapy' and their relevant terms were utilized using every database searching syntax. Final article extraction was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Included studies were limited to the ones published in English between 1995 and 2020 and that just deal with computed tomography (CT) and magnetic resonance imaging (MRI) modalities.Results.A total of 923 studies were screened and 78 were included of which 31 related to the prostate 20 to the breast, 18 to the head and neck, and 9 to the brain tumor site. 98% of the extracted studies performed volumetric analysis. Only 24% of the publications reported the dose deviations resulted from variation in volume delineation Also, heterogeneity in studied populations and reported geometric and volumetric parameters were identified such that quantitative synthesis was not appropriate.Conclusion.This review highlightes the inter- and intra-observer variations that could lead to contouring uncertainties and impede tumor control in radiotherapy. For improving volume delineation and reducing inter-observer variability, the implementation of well structured training programs, homogeneity in following consensus and guidelines, reliable ground truth selection, and proper imaging modality utilization could be clinically beneficial.

The goal of this study is to examine the effect of contrast agent (CA) dose and diffusion coefficient on the estimation of vessel size index (VSI). Three groups of four participants were enrolled in this study and two different experiments were performed. Different dose of CA, namely 0.1 mmol/kg and 0.05 mmol/kg were assessed in two groups of normal subjects. Diffusion coefficient effect was assessed in the third group with high-grade glioma. Imaging included gradient echo and spin-echo DSC and DTI on a 3-T MR Scanner. VSI estimation using half of standard dose of CA showed higher values compared to the application of standard, with a ratio of 2 for the WM and 1.5 for the GM. VSI estimates for tumor tissues (22 µm) were considerably higher compared to contra-lateral Normal-Appearing WM (NAWM, 4 µm, P

Using the 50 kV INTRABEAM® IORT system after breast-conserving surgery: tumor recurrence and organs at risk (OARs), such as the lung and heart, long-term complications remain the challenging problems for breast cancer patients. So, the objective of this study was to address these two problems with the help of high atomic number nanoparticles (NPs). A Monte Carlo (MC) Simulation type EGSnrc C++ class library (egspp) with its Easy particle propagation (Epp) user code was used. The simulation was validated against the measured depth dose data found in our previous study (Tegaw, et al 2020 Dosimetric characteristics of the INTRABEAM ® system with spherical applicators in the presence of air gaps and tissue heterogeneities, Radiat. Environ. Biophys. (10.1007/s00411-020-00835-0)) using the gamma index and passed 2%/2 mm acceptance criteria in the gamma analysis. Gold (Au) NPs were selected after comparing Dose Enhancement Ratios (DERs) of bismuth (Bi), Au, and platinum (Pt) NPs which were calculated from the simulated results. As a result, 0.02, 0.2, 2, 10, and 20 mg-Au/g-breast tissue were used throughout this study. These particles were not distributed in discrete but in a uniform concentration. For 20 mg-Au/g-breast tissue, the DERs were 3.6, 0.420, and 0.323 for breast tissue, lung, heart, respectively, using the 1.5 cm-diameter applicator (AP) and 3.61, 0.428, and 0.335 forbreast tissue, lung, and heart using the 5 cm-diameter applicator, respectively. DER increased with the decrease in the depth of tissues and increase in the effective atomic number (Zeff) and concentration of Au NPs, however, there was no significant change as AP sizes increased. Therefore, Au NPs showed dual advantages such as dose enhancement within the tumor bed and reduction in the OARs (heart and lung).

Despite the advantages of the Fricke gel dosimeter, the use of this tool is associated with limitations in the patient-specific quality assurance due to high uncertainty in the measurement of low dose levels. The present study aimed to develop a Fricke-based gel dosimeter that is sensitive to low dose levels. For this purpose, benzoic acid was added to the ferrous methylthymol-blue gel dosimeter, and the concentration of components was changed. The irradiation of samples was performed using the linear accelerator machine. The ultraviolet–visible spectrophotometer was employed to quantify the dose-responses, auto-oxidation rate, and energy and dose rate dependency. The diffusion rate was measured with magnetic resonance imaging. The maximum difference in absorbance occurred at 439 and 619 nm between un-irradiated and irradiated samples. The sensitivity of the gel dosimeter decreased with an increase in the concentration of methylthymol-blue. The dose-response curve of the gel dosimeter at 439 nm demonstrated high sensitivity in the dose range 0–200 cGy. The auto-oxidation and diffusion rates of the gel dosimeter equaled 0.00106 ± 0.00006 h−1 and 0.845 ± 0.013 mm2 h-1, respectively. The optimized formulation was capable to measure the low dose levels with sufficient confidence. Future studies are needed to evaluate the performance of the optimized formulation in clinical situations.

We performed a cross-sectional multicentre study to assess the prevalence of lymphedema after breast cancer treatment in Iran. All female breast cancer patients who attended our follow-up clinics four or more years after their surgery with no sign of disease were asked to participate in this study. Lymphedema was defined as an increase of 10% in the circumference of the arm on the involved side compared to the opposite arm. The total number of patients participating in this study was 355. The prevalence of lymphedema in the study patients was 17.5%, with the rate varying significantly (between 4 and 21%) among the three study centres (p = 0.007). The mean number of months post surgery was larger for patients with lymphedema (84 months) than for those without (79 months), though this was not statistically significant (p > 0.1). The relationships of various treatment factors and the education levels of the patients to the presence of lymphedema were also evaluated. None of the observed differences were statistically significant aside from those for the type of surgery (mastectomy vs. conservative surgery, p = 0.055), treatment with radiotherapy (p = 0.099), and prescription of a supraclavicular radiation field (p = 0.057), which were only just significant. The rate of lymphedema in our patients was 17.5%, ranging from 4 to 21% in different study centres. Time post surgery, treatment with radiotherapy and the technique used, and nodal radiation seem to be factors that are related to this large variation.

Purpose To evaluate outcome in patients with base of skull meningiomas treated with modern high precision radiation therapy (RT) techniques. Patients and methods 927 patients from three centers were treated with either radiosurgery or fractionated high-precision RT for meningiomas. Treatment planning was based on CT and MRI following institutional guidelines. For radiosurgery, a median dose of 13 Gy was applied, for fractionated treatments, a median dose of 54 Gy in 1.8 Gy single fractions was prescribed. Follow-up included a clinical examination as well as contrast-enhanced imaging. All patients were followed up prospectively after radiotherapy in the three departments within a strict follow-up regimen. The median follow-up time was 81 months (range 1–348 months). Results Median local control was 79 months (range 1–348 months). Local control (LC) was 98% at 1 year, 94% at 3 years, 92% at 5 years and 86% at 10 years. There was no difference between radiosurgery and fractionated RT. We analyzed the influence of higher doses on LC and could show that dose did not impact LC. Moreover, there was no difference between 54 Gy and 57.6 Gy in the fractionated group. Side effects were below 5% in both groups without any severe treatment-related complications. Discussion Based on the pooled data analysis this manuscript provides a large series of meningiomas of the skull base treated with modern high precision RT demonstrating excellent local control and low rates of side effects. Such data support the recommendation of RT for skull base meningiomas in the interdisciplinary tumor board discussions. The strong role of RT must influence treatment recommendations keeping in mind the individual risk–benefit profile of treatment alternatives.

In this retrospective evaluation, we correlated radiation dose parameters with occurrence of optical radiation-induced toxicities. 213 meningioma patients received radiation between 2000 and 2013. Radiation dose and clinical data were extracted from planning systems and patients' files. The range of follow-up period was 2-159 months (median 75 months). Median age of patients was 60 years (range 23-86). There were 163 female and 50 male patients. In 140 cases, at least one of the neuro-optic structures (optic nerves and chiasm) was inside the irradiated target volumes. We found 15 dry eye (7 %) and 24 cataract (11.2 %) cases. Median dose to affected lachrymal glands was 1.47 Gy and median dose to affected lenses was 1.05 Gy. Age and blood cholesterol level in patients with cataract were significantly higher. Patients with dry eye were significantly older. Only two patients with visual problems attributable to radiation treatment were seen. They did not have any risk factors. Maximum and median delivered doses to neuro-optic structures were not higher than 57.30 and 54.60 Gy respectively. Low percentages of cases with radiation induced high grade optic toxicities show that modern treatment techniques and doses are safe. In very few patients with optic side effects, doses to organs at risk were higher than the defined constraint doses. This observation leads to the problem of additional risk factors coming into play. The role of risk factors and safety of higher radiation doses in high grade meningiomas should be investigated in more comprehensive studies.

In 20 patients with high-grade gliomas, we compared two methods of planning for volumetric-modulated arc therapy (VMAT): simultaneous integrated boost (SIB) vs. sequential boost (SEB). The investigation focused on the analysis of dose distributions in the target volumes and the organs at risk (OARs). After contouring the target volumes [planning target volumes (PTVs) and boost volumes (BVs)] and OARs, SIB planning and SEB planning were performed. The SEB method consisted of two plans: in the first plan the PTV received 50 Gy in 25 fractions with a 2-Gy dose per fraction. In the second plan the BV received 10 Gy in 5 fractions with a dose per fraction of 2 Gy. The doses of both plans were summed up to show the total doses delivered. In the SIB method the PTV received 54 Gy in 30 fractions with a dose per fraction of 1.8 Gy, while the BV received 60 Gy in the same fraction number but with a dose per fraction of 2 Gy. All of the OARs showed higher doses (Dmax and Dmean) in the SEB method when compared with the SIB technique. The differences between the two methods were statistically significant in almost all of the OARs. Analysing the total doses of the target volumes we found dose distributions with similar homogeneities and comparable total doses. Our analysis shows that the SIB method offers advantages over the SEB method in terms of sparing OARs.