Search

Aim: In this study, the effects of ionizing radiation and 5-fluorouracil (5-FU)-loaded triblock copolymer-coated magnetic nanoparticles (NPs) on the induction of apoptosis in HT-29 and HCT-116 were investigated. Materials & methods: The percentage of apoptotic cells and alteration of the expression of apoptotic-related proteins were evaluated in treated cells by flow cytometry and western blot analysis, respectively. Results: Combination treatment with 5-FU and radiation had a stronger effect on decreasing Bcl-2 expression and increasing expression of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP compared with each treatment alone. Conclusion: The combination of radiation and triblock copolymer-coated magnetic NPs as 5-FU drug carriers works by triggering apoptosis to improve in vitro treatment efficacy. Additional study may present the NPs as an effective approach for the treatment of colon cancer.

Radiomic features, clinical and dosimetric factors have the potential to predict radiation-induced toxicity. The aim of this study was to develop prediction models of radiotherapy-induced toxicities in prostate cancer patients based on computed tomography (CT) radiomics, clinical and dosimetric parameters. In this prospective study, prostate cancer patients were included, and radiotherapy-induced urinary and gastrointestinal (GI) toxicities were assessed by Common Terminology Criteria for adverse events. For each patient, clinical and dose volume parameters were obtained. Imaging features were extracted from pre-treatment rectal and bladder wall CT scan of patients. Stacking algorithm and elastic net penalized logistic regression were used in order to feature selection and prediction, simultaneously. The models were fitted by imaging (radiomics model) and clinical/dosimetric (clinical model) features alone and in combinations (clinical–radiomics model). Goodness of fit of the models and performance of classifications were assessed using Hosmer and Lemeshow test, − 2log (likelihood) and area under curve (AUC) of the receiver operator characteristic. Sixty-four prostate cancer patients were studied, and 33 and 52 patients developed ≥ grade 1 GI and urinary toxicities, respectively. In GI modeling, the AUC for clinical, radiomics and clinical–radiomics models was 0.66, 0.71 and 0.65, respectively. To predict urinary toxicity, the AUC for radiomics, clinical and clinical–radiomics models was 0.71, 0.67 and 0.77, respectively. We have shown that CT imaging features could predict radiation toxicities and combination of imaging and clinical/dosimetric features may enhance the predictive performance of radiotoxicity modeling.

Using a rectal retractor (RR) during salvage radiotherapy after radical prostatectomy is a promising approach for reducing dose to the rectum. The patient well tolerated the daily RR insertion. This area of research encourages researchers for a comprehensive evaluation of the role of the RR in postprostatectomy radiotherapy.

Here, the effects of combinatorial cancer therapy including radiotherapy (RT) and radiofrequency (RF) hyperthermia in the presence of gold-coated iron oxide nanoparticles (Au@IONPs), as a thermo-radio-sensitizer, are reported. The level of cell death and the ratio of Bax/Bcl2 genes, involved in the pathway of apoptosis, were measured to evaluate the synergistic effect of Au@IONPs-mediated RF hyperthermia and RT. MCF-7 human breast adenocarcinoma cells were treated with different concentrations of Au@IONPs. After incubation with NPs, the cells were exposed to RF waves (13.56 MHz; 100 W; 15 min). At the same time, thermometry was performed with an infrared (IR) camera. Then, the cells were exposed to 6 MV X-ray at various doses of 2 and 4 Gy. MTT (3-[4,5-dimethylthiazol-2-y1]-2,5-diphenyltetrazolium bromide) assay was performed to evaluate cell viability and quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expression ratio of Bax/Bcl2. Cellular uptake of nanoparticles was confirmed qualitatively and quantitatively. The results obtained from MTT assay and qRT-PCR studies showed that NPs and RF hyperthermia had no significant effect when applied separately, while their combination had synergistic effects on cell viability percentage and the level of apoptosis induction. A synergistic effect was also observed when the cancer cells were treated with a combination of NPs, RF hyperthermia, and RT. On the basis of the obtained results, it may be concluded that the use of magneto-plasmonic NPs in the process of hyperthermia and RT of cancer holds a great promise to develop a new combinatorial cancer therapy strategy.

To investigate efficacy of a rectal retractor (RR) on rectal dose during image-guided dose-escalated prostate three-dimensional conformal radiotherapy (3DCRT). In all, 21 patients with localized prostate cancer were treated with a RR for 3DCRT in 40 × 2 Gy. Patient underwent two scans for radiotherapy planning, without and with RR. RR was used for the first half of the treatment sessions. Two plans were created for each patient to compare the effect of RR on rectal doses. PTW-31014 Pinpoint chamber embedded within RR was used for in vivo dosimetry in 6 of 21 patients. The patient tolerance and acute rectal toxicity were surveyed during radiotherapy using Common Terminology Criteria for Adverse Events (CTCAE) v.4.0. Patients tolerated the RR well during 20 fractions with mild degree of anal irritation. Using a RR significantly reduced the rectal wall (RW), anterior RW and posterior RW dose–volume parameters. The average RW Dmean was 29.4 and 43.0 Gy for plans with and without RR, respectively. The mean discrepancy between the measured dose and planned dose was −3.8% (±4.9%). Grade 1 diarrhea, rectal urgency and proctitis occurred in 4, 2 and 3 cases, respectively. There were no grade ≥2 acute rectal toxicities during the treatment. Rectal retraction resulted in a significant reduction of rectal doses with a safe toxicity profile, which may reduce rectal toxicity. Dosimeter inserted into the RR providing a practical method for in vivo dosimetric verification. Further prospective clinical studies will be necessary to demonstrate the clinical advantage of RR.

Background. The standard treatment for breast cancer is breast-conserving surgery (BCS) with radiotherapy. If external beam radiation therapy (EBRT) can be safely replaced with intraoperative radiotherapy (IORT), it will help patients to save their breast and to have equivocal or better results in DFS and overall survival (OS). Methods. A total of 2022 patients with breast cancer treated during 6 years were enrolled in the current study. A total of 657, 376, and 989 patients received EBRT, radical, and boost dose by IORT, respectively, according to the IRIORT consensus protocol. The primary endpoint was recurrence and death. The secondary endpoint was the role of variables in recurrence and death. Results. With a mean follow-up of 34.5 and 40.18 months for the IORT and EBRT groups, respectively, there was a significant difference in DFS between electron boost and X-ray boost groups ( P = 0.037 ) and the electron radical group compared with EBRT ( P = 0.025 ), but there was no significant difference between other boost and radical groups in DFS and OS. Conclusions. IORT can be a preferred treatment modality because of its noninferior outcomes, and in some special conditions, it has superior outcomes compared to EBRT, particularly in delivering radical dose with IORT.

Objectives Metal artifacts are one of the major issues encountered in computed tomography (CT) images since they may make distinguishing healthy and tumor organs and computing dose distribution through radiotherapy very difficult. Accordingly, designing generative adversarial neural networks (GANs) will help reduce metal artifacts. Methods Training and validating images with and without metal artifacts were simulated in MATLAB. Then, these images were used as the input data for the GAN, while CT images of 30 patients with head and neck cancer were used as testing data for the GAN. Finally, the quality metrics of denoised images were compared with those of the noisy images. Results The images of patients with one dental implant have shown more improvement in the oral cavity area (16.81%), which is very important in treatment planning. Simulated images were used for the validation of the GAN's ability for metal artifact reduction. Moreover, the GAN was affected by the density and position of the metal artifacts in the CT images. Conclusions Corrected images allow us to improve the quality of the CT images of patients with metal artifacts.

Background: Radiotherapy plays an essential role in breast cancer treatment following breast conserving surgery even in good-risk patients with ductal carcinoma in situ (DCIS) histology. It can be delivered by many techniques, among which is intraoperative radiotherapy (IORT). In recent years, intraoperative radiation therapy has had the same outcome compared with EBRT. Objectives: We studied whether whole breast radiotherapy (WBRT) could safely be replaced by IORT and its ability to control local recurrence like EBRT in pure DCIS. Methods: We assigned 138 patients into the external beam radiotherapy (EBRT), radical, and boost groups. The patients were treated during the last 6 years in the Cancer Research Center of Shahid Beheshti University of Medical Sciences. A total of 57 patients received EBRT, 45 patients received the radical dose of radiotherapy by IORT (36 patients received intraoperative electron radiotherapy [IOeRT] and 9 patients received intraoperative X-ray radiotherapy [IOxRT]) according to the IRIORT consensus protocol, and 36 patients received the boost dose of radiotherapy by IORT (15 patients received IOeRT and 21 patients received IOxRT). The IORT and EBRT groups were compared. The primary endpoint was local recurrence and death and the secondary endpoint was the role of variables in local recurrence. Results: With the mean follow-up of 37 months for the IORT group and 40.1 months for the EBRT group, local recurrence occurred in 8.8% (5 patients), 13.9% (5 patients), and 2.2% (1 patient) of the patients in the EBRT, boost, and radical groups, respectively. Concerning the local recurrence, no significant difference was observed between the radical and EBRT groups (P = 0.058) and between the boost and EBRT groups (P = 0.12). Hazard ratios (HRs) of grade, hormone receptor (HR), tumor size, and age in disease-free survival were evaluated and none of these variables had a significant role in local recurrence. Conclusions: IORT is a good alternative for WBRT in DCIS patients because of its non-inferiority results in comparison with EBRT. Being careful about age, tumor size, biological markers, and margin status is of high importance when using IORT for DCIS.

In this study, the beam characteristics of a Euromechanics add-on MLC that has been installed on a Varian CLINAC 2100 C/D linear accelerator are presented. This was the first installation of 60-leaf PMLC from Euromechanics Company worldwide and all mechanical and dosimetric parameters were measured before clinical use of this kind of MLC. Mechanical tests were executed for different gantry and collimator angles. Leaf position accuracy and leaf gap reproducibility were checked with four different tests. The leaf transmissions, collimator (Sc), phantom (Sp), total (Sc,p) scatter factors, output of the machine, beam profiles for off-axis ratios, central axis depth dose, flatness, symmetry and penumbra have been measured for different field sizes pre and post MLC installation in 6 and 18 MV-mode. To evaluate the effect of new data on clinical plans, different beam setup configurations conformed with MLC and custom blocks were planned on CT images of thorax a CIRS phantom model 002LFC in the same treatment planning system. Leaf position in picket fence test found to be in range between 4.89–5.02 cm instead of nominal 5 cm, however the results of this test with EPIDs image and PIPSpro software showed the higher deviation rather than the results reported from the tests with EBT3 films. The measured data showed that on average Sc,p and Sc were increased 0.22% (P = 0.86) and 0.34% (P = 0.86) for 6 MV and 0.37% (P = 0.84) and 0.42% (P = 0.88) for 18 MV beams for different field sizes, respectively. Good agreement was observed between the PDD and profile curves pre and post MLC installation that was expected based on no changes in beam energy and geometry of the collimators. Based on the mechanical and dosimetry results which have been achieved from our different standard tests, it was found no significant differences between pre and post MLC installation values. This indicates, installation and using this system is clinically acceptable.

The aim of this study was the evaluation of induced DNA damages of human prostate cancer cells, DU-145, treated with a combination of radiofrequency capacitive hyperthermia (HT) and teletherapy (EBRT) compared to a combination of teletherapy with high-dose rate brachytherapy (BR).DU-145 cells were cultured as spheroids in 300 micron diameter. Then the following treatments were conducted: (a) EBRT at doses of either 2 Gy or 4 Gy of photon 15 MV, (b) HT for 0, 30, 60, and 90 minutes duration at 43 °C from a 13.56 MHz radiofrequency capacitive heating device (Celsius TCS), (c) BR with Ir-192 seed at doses of either 2 Gy or 5.5 Gy, (d) The mentioned HT followed by EBRT (HT + EBRT) and (e) EBRT followed by BR (EBRT + BR). Alkaline comet assay was performed to measure tail moment.The induced DNA damages of DU-145 cells treated by adding HT to EBRT compared with EBRT alone, showed a significant enhancement; 3.28 and 5.14 times respectively for 30 and 60 minutes HT. By plotting dose-response curves, we could find a range of doses, which create radiobiological iso-effect in HT + EBRT and EBRT + BR treatments.This study suggests that about DNA damages of DU-145 cells, HT + EBRT could partly be considered as an alternative to EBRT + BR.

Glioblastoma multiform (GBM) is the most prevalent and aggressive type of primary brain tumor. None of the current conventional treatment methods has improved treatment considerably. Therefore, in this study the effect of magnetic nanoparticles coated with poly (caprolactone)-poly (ethylene glycol) (PCL-PEG) as a 5-iodo 2'deoxyuridine (IUdR) carrier in the presence of hyperthermia and 6 MV (megavoltage) X-ray radiation, were investigated in a spheroid model of U87MG glioblastoma cell line using colony formation assay.First, the human glioblastoma cell line U87MG was cultured as a spheroid using the liquid overlay technique. Spheroids on day 10 with 100 mm diameters were treated with 1 µM IUdR or nanoparticles as IUdR carriers for one volume doubling time (VDT) of spheroids (67 h) and hyperthermia at 43 °C for 1 h, and then irradiated with 2 Gy of 6 MV X-ray in different groups. Finally, the effect of treatment on colony-forming ability was obtained by colony formation and alkaline assay.Our results revealed that hyperthermia in combination with radiation could significantly reduce the colony number of glioblastoma spheroid cells treated with IUdR or nanoparticles as IUdR carriers. However, the extent of reduction in colony number following treatment with IUdR-loaded nanoparticles in combination with hyperthermia and then X-ray radiation was significantly more than free IUdR.According to this study, PCL-PEG-coated magnetic nanoparticles are effective delivery vehicles for IUdR into cells. Moreover, they can act as a radiosensitizer and thermosensitizer in the treatment of the glioblastoma cell line.

Glioma is one of the most common malignant cancers of the central nervous system (CNS). Radiatherapy and chemotherapy may be used to slow the growth of tumors that cannot be removed with surgery. The current study developed a combination therapy tool using Nanographene oxide (NGO) functionalized with poly lactic-co-glycolic acid (PLGA) as a carrier of 5-iodo-2-deoxyuridine (IUdR) for glioma cancer treatment. U87MG cells were treated in different groups with IUdR, PLGA-coated Nanographene oxide (PLGA-NGO), IUdR-loaded PLGA-coated Nanographene oxide (IUdR-PLGA-NGO), 2 Gy 6 MV X-ray radiation, and near-infrared region (NIR) laser radiation. PLGA-NGO showed excellent biocompatibility, high storage capacity for IUdR and high photothermal conversion efficiency. It was effectively employed to create cell damage in the U87MG cell line in the presence of X-ray (6 MV) and NIR laser. Moreover, IUdR-PLGA-NGO + X-ray + NIR laser significantly reduced the plating efficiency of the cells in comparison with IUdR-PLGA-NGO + X-ray and IUdR-PLGA-NGO + NIR laser. Furthermore, Prussian blue staining showed that IUdR-PLGA-NGO-SPIONs were delivered into glioblastoma cells. The PLGA-NGO loaded with IUdR under NIR and X-ray radiation exhibited the highest cytotoxicity toward U87MG cells when compared with other treatment methods, indicating efficient radio-photothermal targeted therapy.

Objectives Immediately or after head-and-neck (H&N) cancer chemoradiotherapy (CRT), patients may undergone significant sensorineural hearing loss (SNHL) which could affect their quality of life. Radiomic feature analysis is proposed to predict SNHL induced by CRT. Material and methods 490 image features of 94 cochlea from 47 patients treated with three dimensional conformal RT (3DCRT) for different H&N cancers were extracted from CT images. Different machine learning (ML) algorithms and also least absolute shrinkage and selection operator (LASSO) penalized logistic regression were implemented on radiomic features for feature selection, classification and prediction. Also, LASSO penalized logistic model was used for outcome modelling. Results The predictive power of ten ML methods was more than 70% (in accuracy, precision and area under the curve of receiver operating characteristic curve (AUC)). According to the LASSO penalized logistic modelling, 10 of the 490 radiomic features selected as the associated features with SNHL status. All of the 10 features were statistically associated with SNHL (all of adjusted P-values Conclusion CT radiomic analysis proposed in this study, could help in the prediction of hearing loss induced by chemoradiation. Our study also, demonstrates that combination of radiomic features with clinical and dosimetric variables can model radiotherapy outcome such as SNHL.

The present study aims to calculate the received dose by lungs and heart, as organs at risk (OAR), during intraoperative electron radiotherapy (IOERT) of left breast cancer at the presence and absence of shielding disk using Monte Carlo (MC) simulation. LIAC 12, a dedicated IOERT Linac, and an anthropomorphic phantom were considered in this study to simulate particle tracks of 6, 8, 10, and 12 MeV nominal electron energies using EGSnrc MC particle transport simulation code. The results showed that for increasing electron beam energies in the absence of shielding disk, left lung and heart dose would also be increasing so that, maximum left lung and heart dose respectively increases from 0.512 to 9.920 Gy and from 0 to 0.506 Gy with increment of electron energy from 6 to 12 MeV. Employing the shielding disk in 6 and 8 MeV energy can reduce the heart and left lung maximum dose to zero. On the other hand, this dose reduction at 10 and 12 MeV energy was respectively about 99% and 93.5% for heart and 99.9% and 92.9% for left lung. Right lung did not receive a remarkable dose both in presence and absence of shielding disk. From the results, it can be concluded that employing the shielding disk can effectively reduce the received dose to OARs.

Background and Objective: Prostate cancer is the second cause of death in men worldwide. In this study, the cytotoxic effects of PLGA polymer-coated gold Magnetic Nanoparticles (MGNPs), as a novel treatment to enhance radiation and thermal sensitivity in the presence of hyperthermia (43°C) and electron beam, on DU145 prostate cancer cells were investigated. Methods: Nanoparticles were characterized using TEM, DLS, XRD and SAED methods. MGNPs entrance into the cells was determined using Prussian blue staining and TEM. Furthermore, the cytotoxic effects of combinatorial treatment modalities were assessed by applying colony and sphere formation assay. Results: Our results revealed that the decrease of colony and sphere numbers after combinatorial treatment of hyperthermia and radiation in the presence of nanoparticles was significantly higher than the other treatment groups (P Conclusion: According to the study, magnetic gold nanoparticles, in addition to having a high atomic number, can effectively transmit heat produced inside them to the adjacent regions under hyperthermia, which increases the effects of radio-thermosensitivity, respectively.

Background and Purpose: As a feasible approach, radiotherapy has a great role in prostate cancer (Pca) management. However, Pca patients have an increased risk of femoral head damages including fractures after radiotherapy. The mechanisms of these complications are unknown and time of manifestations is too long; however, they may be predicted by early imaging. The main purpose of this study was to assess the early changes in femoral heads in Pca patients treated with intensity-modulated radiation therapy (IMRT) using multiparametric magnetic resonance imaging (mpMRI) radiomic feature analysis. Materials and Methods: Thirty Pca patients treated with IMRT were included in the study. All patients underwent two mpMRI pre- and postradiotherapy. Thirty-four robust radiomic features were extracted from T1, T2, and apparent diffusion coefficient (ADC) obtained from diffusion-weighted images. Wilcoxon signed-rank test was performed to assess the significance of the change in the mean T1, T2, and ADC radiomic features postradiotherapy relative to preradiotherapy values. The percentage change values were normalized based on the natural logarithm base ten. Features were also ranked based on their median changes. Results: Sixty femoral heads were analyzed. All radiomic features have undergone changes. Significant postradiotherapy radiomic feature changes were observed in 20 and 5 T1- and T2-weighted radiomic features, respectively (P < 0.05). ADC features did not vary significantly postradiotherapy. The mean radiation dose received by femoral heads was 40 Gy. No fractures were observed within the follow-up time. Different features were found as high ranked among T1, T2, and ADC images. Conclusion: Early structural change analysis using radiomic features may contribute to predict postradiotherapy fracture in Pca patients. These features can be identified as being potentially important imaging biomarkers for predicting radiotherapy-induced femoral changes.

Aim Verification of dose distributions for gynecological (GYN) brachytherapy implants using EBT Gafchromic film. Background One major challenge in brachytherapy is to verify the accuracy of dose distributions calculated by a treatment planning system. Materials and methods A new phantom was designed and fabricated using 90 slabs of 18 cm × 16 cm × 0.2 cm Perspex to accommodate a tandem and Ovoid assembly, which is normally used for GYN brachytherapy treatment. This phantom design allows the use of EBT Gafchromic films for dosimetric verification of GYN implants with a cobalt-60 HDR system or a LDR Cs-137 system. Gafchromic films were exposed using a plan that was designed to deliver 1.5 Gy of dose to 0.5 cm distance from the lateral surface of ovoids from a pair of ovoid assembly that was used for treatment vaginal cuff. For a quantitative analysis of the results for both LDR and HDR systems, the measured dose values at several points of interests were compared with the calculated data from a commercially available treatment planning system. This planning system was utilizing the TG-43 formalism and parameters for calculation of dose distributions around a brachytherapy implant. Results The results of these investigations indicated that the differences between the calculated and measured data at different points were ranging from 2.4% to 3.8% for the LDR Cs-137 and HDR Co-60 systems, respectively. Conclusion The EBT Gafchromic films combined with the newly designed phantom could be utilized for verification of the dose distributions around different GYN implants treated with either LDR or HDR brachytherapy procedures.

BackgroundIntraoperative radiotherapy is a method of choice to deliver a critical radiation dose to the tumour bed immediately after surgical excision.AimThe purpose of this work is to check the dose delivered to the patients during intraoperative electron beam radiation therapy (IOERT) in the conservative treatment of breast cancer, by means of reference dose measurement using radiochromic (EBT-2) films.Material and methodsNinety patients with early-stage breast cancer underwent exclusive IOERT to the tumour bed using a LIAC linear accelerator. Absolute dose measurements were done with film pieces. After irradiation, the pixel values of the films were obtained via MATLAB and ImageJ softwares. Calibration curve was also used for calculating net optical density. Expected dose was compared to the patient delivered dose.ResultsThe mean deviation of the delivered dose from the expected one was 2·56% that is well in the accepted criteria. Only in one case, there was a larger deviation due to barometer miscalibration.FindingsEBT-2 film response is independent from dose-per-pulse and as it was shown in this study it can be robustly used during breast IOERT for dosimetric and also positioning verifications.

Introduction Glioblastoma multiform (GBM) is the most common malignant primary brain tumor in humans. Current conventional treatment could not effectively increase the survival rate of patients who suffered from GBM. In clinical view, some experiments which can mimic in vivo conditions to evaluate anticancer agent effects on tumors are very useful. We can fairly reach to this goal using 3-dimentional spheroids rather than monolayer culture. The aim of this study was to determine the cytotoxicity caused by Navelbine, hyperthermia and radiation on glioma spheroids. Methods The spheroid cells were separately or simultaneously treated with the doses of 7.5 μg/ml Navelbine for 50.3 h, irradiated with 2 Gy and incubated at 43 °C for 1 h. Comet and colony formation assays were applied to assess the DNA damages and survival rate of the cells. Results In both comet and colony formation assays, cell damage in all treated groups was significantly higher in comparison with control group ( P 0.05). Moreover, the synergistic effect of combined groups such as: hyperthermia and radiotherapy, Navelbine and radiotherapy and combination of Navelbine-hyperthermia-radiotherapy was observed. Conclusions Combined agents with low concentration can cause a synergistic effect on treatment procedure and increased damages in multicellular spheroids.

Conventional cancer treatment methods suffer from many limitations such as non-specificity in discrimination between healthy and malignant cells. The aim of this study was to investigate the role of polymeric gold-photoactive nanoparticles (PGPNPs) conjugated with folic acid (FA) as theranostic nanoparticles for active targeting, real-time fluorescence tracing and radiosensitivity inducition in LNCaP prostate cancer cells.The cellular uptake and cytotoxicity effect of gold nanoparticles (PGPNPs and PGPNPs-FA) after 2 and 24 h treatment were evaluated in in both cancer (LNCaP) and normal (HUVEC) cells using fluorescent microscopy, Induced coupled plasma optical emission spectrometry (ICP-OES) and Tetrazolium bromide dye (MTT), respectively. The therapeutic efficacy was analyzed on the LNCaP cells. For this purpose, LNCaP cells were treated by nanoparticles and ionizing radiation, and the synergistic effect of treatment methods were evaluated by colony formation assay (CFA) and Flow cytometry analysis.The results of fluorescence imaging and ICP-OES data showed that the LNCaP cells absorbed PGPNP-FA nanoparticles more than PGPNP (P 0.001). Also, the uptake of nanoparticles was significantly greater in cancer cells than in healthy ones (P 0.01). MTT assay results indicated higher cytotoxic effect of nanoparticles conjugated with FA in folate-receptor overexpressing LNCaP cancer cells compared to HUVEC normal cells (P 0.01). Furthermore, CFA and Flow cytometry results demonstrated that combinatorial therapy of polymeric gold nanoparticles with/without FA and ionizing radiation at various doses (2, 4 and 6 Gy) had a synergistic effect on survival fraction and induction of apoptotic and necrotizing cell death (P 0.01).PGPNPs-FA nanoparticles led to higher and more specific uptake and accumulation of nanoparticles in LNCaP cells, thereby increasing the ability of gold nanoparticles as radio-sensitizer.

Single fraction nature of intraoperative radiotherapy highly demands a quality assurance procedure to qualify both beam setup and treatment delivery. The aim of this study is to evaluate the treatment setup during breast intraoperative electron radiotherapy (IOERT) and in-vivo dose delivery verification.Twenty-five breast cancer patients were enrolled and setup verification for each case was performed using C-arm imaging. The received dose by surface and distal end of target was measured by EBT2 film. The significance level of difference between obtained dosimetry results and predicted ones was evaluated by the T statistical test.Acquired C-arm images in two different oblique views revealed any misalignment between the applicator and shielding disk. The mean difference between the measured surface dose and expected one was 1.8% ± 1.2 (p = 0.983) while a great disagreement, 11.1% ± 1.5 (p 0.001), was observed between the measured distal end dose and expected one. This discrepancy is mainly correlated to the backscattering effect from the shielding disk. Target depth nonuniformities can also contribute to this remarkable difference.Employing the intraoperative imaging for IOERT setup verification can considerably improve the treatment quality. Therefore, it is suggested to implement this imaging procedure as a part of treatment quality assurance. Favorable agreement between the predicted and measured surface doses demonstrates the applicability of EBT2 film for dose delivery verification. The results of in-vivo dosimetry showed that the electron backscattering from employed shielding disk can affect the received dose by the distal end of tumor bed.

To develop different radiomic models based on the magnetic resonance imaging (MRI) radiomic features and machine learning methods to predict early intensity-modulated radiation therapy (IMRT) response, Gleason scores (GS) and prostate cancer (Pca) stages. Thirty-three Pca patients were included. All patients underwent pre- and post-IMRT T2-weighted (T2 W) and apparent diffusing coefficient (ADC) MRI. IMRT response was calculated in terms of changes in the ADC value, and patients were divided as responders and non-responders. A wide range of radiomic features from different feature sets were extracted from all T2 W and ADC images. Univariate radiomic analysis was performed to find highly correlated radiomic features with IMRT response, and a paired t test was used to find significant features between responders and non-responders. To find high predictive radiomic models, tenfold cross-validation as the criterion for feature selection and classification was applied on the pre-, post- and delta IMRT radiomic features, and area under the curve (AUC) of receiver operating characteristics was calculated as model performance value. Of 33 patients, 15 patients (45%) were found as responders. Univariate analysis showed 20 highly correlated radiomic features with IMRT response (20 ADC and 20 T2). Two and fifteen T2 and ADC radiomic features were found as significant (P-value ≤ 0.05) features between responders and non-responders, respectively. Several cross-combined predictive radiomic models were obtained, and post-T2 radiomic models were found as high predictive models (AUC 0.632) followed by pre-ADC (AUC 0.626) and pre-T2 (AUC 0.61). For GS prediction, T2 W radiomic models were found as more predictive (mean AUC 0.739) rather than ADC models (mean AUC 0.70), while for stage prediction, ADC models had higher prediction performance (mean AUC 0.675). Radiomic models developed by MR image features and machine learning approaches are noninvasive and easy methods for personalized prostate cancer diagnosis and therapy.

Background:Currently, the potential application of gold nanoparticles (AuNPs) to increase the efficiency of radiation therapy has been widely investigated. However, lack of an appropriate method to estimate the dose distribution in a nanoparticle-laden tissue limits the applicability of nanoparticles in radiotherapy clinics. Polymer gel dosimetry provides an accurate and precise system that facilitates the measurement of dose distribution in full three dimensions.Objective: In this study, the effect of radiation dose enhancement of AuNPs was assessed through gel dosimetry analysis.Material and Methods: For this purpose, AuNPs were integrated in MAGIC_f polymer gel dosimeter and irradiated by 6 Mv X-ray beam. The irradiated gel was then evaluated through two modalities of magnetic resonance imaging (MRI) and optical computed tomography (OCT).Result: MRI and OCT scanning of MAGIC_f gels containing 0.1 mM AuNPs demonstrated dose enhancements of 7.8% and 6.8%, respectively.Conclusion: Polymer gel dosimetry has the potential to provide a new platform for the investigation and optimization of the applicability of nanoparticles in radiation therapy.

Background The main purpose of this study was to assess the structural changes in the bladder wall of prostate cancer patients treated with intensity-modulated radiation therapy using magnetic resonance imaging texture features analysis and to correlate image texture changes with radiation dose and urinary toxicity. Methods Ethical clearance was granted to enroll 33 patients into this study who were treated with intensity-modulated radiation therapy for prostate cancer. All patients underwent two magnetic resonance imagings before and after radiation therapy (RT). A total of 274 radiomic features were extracted from MR-T2W–weighted images. Wilcoxon singed rank-test was performed to assess significance of the change in mean radiomic features post-RT relative to pre-RT values. The relationship between radiation dose and feature changes was assessed and depicted. Cystitis was recorded as urinary toxicity. Area under receiver operating characteristic curve of a logistic regression–based classifier was used to find correlation between radiomic features with significant changes and radiation toxicity. Results Thirty-three bladder walls were analyzed, with 11 patients developing grade ≥2 urinary toxicity. We showed that radiomic features may predict radiation toxicity and features including S5.0SumVarnc, S2.2SumVarnc, S1.0AngScMom, S0.4SumAverg, and S5. _5InvDfMom with area under receiver operating characteristic curve 0.75, 0.69, 0.65, 0.63, and 0.62 had highest correlation with toxicity, respectively. The results showed that most of the radiomic features were changed with radiation dose. Conclusion Feature changes have a good correlation with radiation dose and radiation-induced urinary toxicity. These radiomic features can be identified as being potentially important imaging biomarkers and also assessing mechanisms of radiation-induced bladder injuries.

Background: Transfusion-associated graft-versus-host disease is a complication being mortal in 90% of cases. Today, Co-60 devices are utilized for the suppression of the lymphocytes to prevent this complication. Due to problems such as radioactive source age, problems in source replacement, and protection risks, we sought to replace a linear accelerator for this purpose and carefully determinate the X-ray dose and other settings. Methods: First, the venous blood of the right-handed people with blood group O+ was exposed to different radiation doses of Linac and diluted. The proliferative responses of the exposed cells were examined by MTT assay and TB in comparison with controls after 48h. The average percentage of cell survival at each delivered dose and the required dose of radiation for the inhibition of lymphocyte proliferation were checked and the optimal dose of radiation was obtained as 25 Gy in a special radiation condition. Results: The results indicated that the irradiation with 25 Gy at 3.5 Gy/min in the internal mid-plan by compact 6MV for 30*30-field size at an 8 cm-distance of the samples to the source and 1370-monitor unit could completely suppress the lymphocytes. Under the same condition and 1096-monitor unit for total 20 Gy, we did not find optimal results. Conclusions: In this research, we found that a linear accelerator in a specific exposure condition is a suitable alternative for Cobalt-60 sources and the above-mentioned condition of irradiation can be used to overcome the GVHD concern.

Cancer stem cells (CSCs) have been identified as the main center of tumor therapeutic resistance. They are highly resistant against current cancer therapy approaches particularly radiation therapy (RT). Recently, a wide spectrum of physical methods has been proposed to treat CSCs, including high energetic particles, hyperthermia (HT), nanoparticles (NPs) and combination of these approaches. In this review article, the importance and benefits of the physical CSCs therapy methods such as nanomaterial-based heat treatments and particle therapy will be highlighted.

The aim of this study was to generate the dose-response curves by six normal tissue complication probability (NTCP) models and ranking the models for prediction of radiation induced sensorineural hearing loss (SNHL) caused by head and neck radiation therapy (RT).Pure tone audiometry (PTA) was performed on 70 ears of patients for 12 months after the completion of RT. The SNHL was defined as a threshold shift ≤15 dB at two contiguous frequencies according to the common toxicity criteria for adverse events scoring system. The models evaluated were: Lyman and Logit; Mean Dose; relative seriality (RS); Individual critical volume (CV); and population CV models. Maximum likelihood analysis was used to fit the models to experimental data. The appropriateness of the fit was determined by the two-sample Kolmogorov-Smirnov test. Ranking of the models was made according to Akaike's information criterion.The dose of 50% complication rate (DCochlea shows a different behavior against different NTCP models; it may be due to its small size.

Background: Advanced quantitative information such as radiomics features derived from magnetic resonance (MR) image may be useful for outcome prediction, prognostic models or response biomarkers in Glioblastoma (GBM), knowledge about their Reproducibility and robustness is essential. The purpose of this study was to investigate the reproducible and non-redundant radiomics texture features in oncological GBM MRI based on test-retest setup. Methods: Thirteen patients with recurrent GBM who underwent repeated MR imaging approximately two day interval were subjected to this study. Lesions were segmented using competitive region-growing based algorithm. Following delineation and segmentation of lesions, 158 quantitative 3D features based on intensity histograms (IH), gray level run-length (GLRLM), gray level co-occurrence (GLCM), gray level size-zone texture matrices (GLSZM), neighborhood-difference matrices (NDM), and geometric features were extracted from the 3D-tumor volumes of each lesion. For every radiomics feature, test-retest was assessed with the intra-class correlation coefficient (ICC) and the concordance correlation coefficient (CCC) and finally the most reproducible and robust radiomics features were selected. Results: Results shows that the 74% of assessed radiomics features had a high test-retest stability in terms of their ICC. There were 107 radiomics features with CCC >0.95 and 49 radiomics features were non-redundant after grouping features with R2Bet ? 0.95. Conclusions: Test-retest and correlation analyses have identified non-redundant radiomics features and this feature are prone to errors if they employed as quantitative biomarker for GBM image analysis. However when we use robust and redundant feature, quantitative image radiomics features are informative and prognostic biomarkers for GBM Magnetic resonance imaging.

Many combined therapies have been proposed to enhance radiotherapy outcome, but they have several limitations. As a new feasible strategy, combination of radiotherapy with bacteria showed a significant positive impact on the tumor treatment and metastasis inhibition. Although probiotic bacteria and radiotherapy alone can be effective in the treatment of different cancers, the combination of these two therapies seems to enhance therapeutic outcome and is cost-effective. Bacterial cells can act as therapeutic/gene/drug delivery vehicles as well as theranostic agents. In this communication, we reviewed current evidences, studies, suggestions, and future-based directions on combination of radiotherapy and bacteria. In another sections, an overview on tumor hypoxia, bacteria in cancer therapy, and combination of radiotherapy and bacteria is presented. A brief overview on trials and animal studies which used bacteria to protect normal tissues against radiotherapy-induced complications is also included.

The aim of this study was to investigate the effect of hyperthermia, 6 MeV electron radiation and combination of these treatments on cancer cell line DU145 in both monolayer culture and spheroids enriched for prostate cancer stem cells (CSCs). Flowcytometric analysis of the expression of molecular markers CD133+/CD44+ was carried out to determine the prostate CSCs in cell line DU145 grown as spheroids in serum-free medium. Following monolayer and spheroid culture, DU145 cells were treated with different doses of hyperthermia, electron beam and combination of them. The survival and self-renewing of the cells were evaluated by colony formation assay (CFA) and spheroid formation assay (SFA). Flowcytometry results indicated that the percentage of CD133+/CD44+ cells in spheroid culture was 13.9-fold higher than in the monolayer culture. The SFA showed significant difference between monolayer and spheroid culture for radiation treatment (6 Gy) and hyperthermia (60 and 90 min). The CFA showed significantly enhanced radiosensitivity in DU145 cells grown as monolayer as compared to spheroids, but no effect of hyperthermia. In contrast, for the combination of radiation and hyperthermia the results of CFA and SFA showed a reduced survival fraction in both cultures, with larger effects in monolayer than in spheroid culture. Thus, hyperthermia may be a promising approach in prostate cancer treatment that enhances the cytotoxic effect of electron radiation. Furthermore, determination and characterization of radioresistance and thermoresistance of CSCs in the prostate tumor is the key to develop more efficient therapeutic strategies.

Aims The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue. Material and methods Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters. Results The mean CTDIvol was 1.34 mGy ± 0.19 and the mean SSDE was 1.7 mGy ± 0.16. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter. Conclusion The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks.