This study proposes a deep learning-based regression prediction method utilizing the PIDE3.4 radiation biological effects database for predicting Relative Biological Effectiveness (RBE). The method employs a matrix-based data processing pipeline, applying MinMax normalization to numerical features and One-Hot encoding to categorical features. The experimental dataset comprises 999 samples, with 800 allocated for training and 199 reserved as an independent test set. Results demonstrate that the method achieves high accuracy and stability in RBE prediction. During training, a 5-fold cross-validation approach yielded an average coefficient of determination (R²) of 0.8959 and a Mean Absolute Error (MAE) of 0.2935. Predicted values closely align with ground truth values within the primary RBE range of 0–7, providing a reliable data-driven tool for predicting radiation biological effects and optimizing particle therapy treatment planning. Furthermore, applying the method to a clinical nasopharyngeal carcinoma case in carbon ion radiotherapy, unlike existing RBE prediction methods that focus solely on a single biological endpoint, this method overcomes this limitation. By integrating physical parameters—such as physical dose and linear energy transfer—along with biological parameters like region-specific cell types, the method achieves spatially heterogeneous prediction of RBE. Additionally, this study innovatively constructs a cross-cell RBE prediction framework based on ten-dimensional continuous cell-biological features, enabling RBE prediction for cell types absent from the training data, and achieved a generalization performance of R² = 0.7600 and MAE = 0.4055 on unseen cell types. This provides a novel approach for precisely assessing biological effects on tumors and organs at risk and for optimizing individualized treatments.

Focused very-high-energy electron (VHEE) beams can produce localized dose enhancement at selected depths, but irradiation of a finite target requires coordinated control of multiple focal positions, incidence directions, and beam weights while limiting exposure of nearby organs at risk (OARs). We present Focal-Point Scanning (FPS), a dose delivery and optimization method developed for laser wakefield accelerator (LWFA)-driven VHEE beams. The method is based on a two-dipole focusing system that produces single-plane beam convergence and allows the focal position to be varied by changing the magnetic field strength. FPS distributes focal points throughout the planning target volume and determines focal-point-specific incidence sectors according to the geometry of nearby critical OARs. The method was evaluated using the AAPM TG119 C-shape benchmark and one previously treated lung radiotherapy case. At matched target coverage, FPS reduced the TG119 Core mean dose by approximately one half relative to parallel VHEE and intensity-modulated x-ray plans, approaching the single-field proton pencil-beam-scanning reference. In the lung case, FPS maintained target coverage comparable to the clinical volumetric modulated arc therapy reference while reducing the mean dose to every evaluated OAR; spinal-cord mean and maximum doses decreased by 93.2

BACKGROUND:Dosimetric studies of targeted alpha therapy (TAT) show that microscopic heterogeneity in geometry and source distribution strongly affects dose-effect relationships, underscoring the potential of microdosimetry. While Monte Carlo (MC) simulation is the gold standard for dose assessment, its application to TAT microdosimetry remains methodologically challenging and computationally inefficient. This necessitates a systematic and implementable methodology for microdosimetric simulation and analysis. PURPOSE:This study aimed to establish a quantitative MC simulation framework for TAT microdosimetry, in which heterogeneous conditions are analytically processed and Type A standard uncertainty of derived microdosimetric quantities can be estimated. METHODS:(1) Elementary-source events were defined under arbitrary microscopic conditions, and the raw moments of single-event microdosimetric quantities scored via MC simulation were identified for each event. The heterogeneous microdosimetric environments were modeled as weighted mixtures of elementary events. (2) Analytical error propagation was derived to explicitly quantify the standard error (SE) of mixture quantities. This enables, for the first time, a trace-back mechanism to identify error-dominating source components for optimized resource allocation. (3) A long-range radiation correction for α -emitting nuclides was developed to bridge microscopic energy deposition with macroscopic absorbed dose, enabling the acquisition of reliable results under affordable computational resources. RESULTS:A Geant4-based application implemented the framework in heterogeneous microscopic models. The validation against repeated direct sampling demonstrated consistency between the mixture framework and conventional repeated direct simulation. Subsequently, the MC SE of single-event dose-mean specific energy was adopted as the convergence criterion for simulation. Long-range radiation effects were effectively compensated, relaxing spatial-extent requirements for TAT MC geometries. The source-mixture scheme allowed reuse of elementary microdosimetric data, supporting efficient factor analysis for diverse heterogeneous conditions. Coupled with cell-line parameters and the non-Poisson-corrected microdosimetric kinetic model, the analytic results yielded dose-response characteristics consistent with prior studies of TAT. CONCLUSIONS:The framework enables trace-back variance analysis and microdosimetry-compatible variance reduction. This enables precision-controlled MC microdosimetry in TAT, and supports flexible analysis of heterogeneity factors and reliable microdosimetric assessment.

Objective: Low-kV radiotherapy is used to treat skin cancer and superficial benign conditions. This study aims to quantify the variations in the relative biological effectiveness (RBE) of 50 kV and 70 kV X-rays emitted from cone-shaped applicators and bare probes, using the Monte Carlo simulation in the water and skin tissue environments. No study has computationally examined the RBE of skin tissue within a realistic cellular context. Approach: To evaluate the RBE, a Monte Carlo model of the VF-80/mu XHP X-ray unit and various applicator diameters was built using the TOPAS Monte Carlo software. X-ray energy spectra from the surfaces of each applicator diameter and the bare probe at energies of 50 kV and 70 kV were analyzed to calculate the corresponding secondary electron energy spectra at different distances in the water phantom and skin tissue. Then, TOPAS-nBio Monte Carlo code was used to determine the RBE values, which were calculated based on the occurrence of double-strand breaks and single-strand breaks. Main results: The X-ray unit with a bare probe has about 4% higher RBE compared to one with the applicators. However, due to factors like depth-dose uniformity, protection of healthy tissue, clinical usability, and reproducibility, bare probe X-ray units are not suitable for the clinical applications. Variations in applicator diameter cause only a slight change, about 2.5%, in the RBE of X-rays emitted from each applicator's surface. The RBE value increases with distance from the applicator surface, rising by approximately 10% as the distance increases from 1 to 10 mm in water and from 50 to 3000 mu m in skin tissue. RBE values calculated within skin tissue are about 5.3% higher than those in water for 50 kV X-rays and about 4.7% higher for 70 kV X-rays. Significance: The open-ended cone applicators act as collimators, which influence the RBE of X-rays emitted from the VF-80/mu XHP X-ray unit. Since RBE values are higher in skin tissue compared to the water phantom, a lower prescribed dose would be better suited for accurate skin irradiation.

In medical image segmentation tasks, acquiring large amounts of high-quality annotated data is often difficult and costly. Therefore, automatic segmentation methods under few-shot learning settings hold significant research and practical value. Although Transformer-based models have achieved significant progress in medical image segmentation, the traditional multi-head attention mechanism struggles to effectively coordinate cross-scale features due to the substantial semantic granularity differences across feature levels. This limitation hinders models from fully integrating multi-granularity semantic information under sparse annotation conditions. Additionally, while Transformers excel at modeling global context, they face limitations in pixel-level modeling of local structures (e.g., minute blood vessels, tissue edges), further complicating the segmentation of subtle anatomical features in few-shot scenarios. To address these challenges, this paper proposes MGCAA-Net, a medical image segmentation model based on a multi-granularity gating mechanism and Channel-wise Adaptive Activation. Within its encoding network, MGCAA-Net effectively aggregates multi-scale high-level semantic features, enabling efficient cross-scale feature collaboration and enhancing pixel-level perception capabilities. This allows for accurate segmentation of minute targets and narrow regions within complex pathological areas. Our Experimental results demonstrate that the model achieves outstanding segmentation performance under single-modality training (CT or MRI). Furthermore, in few-shot cross-domain transfer tasks (CT -> MRI), it efficiently learns cross-modal features and delivers excellent segmentation performance, validating its exceptional generalization capability. On the Synapse datasets, MGCAA-Net achieved high average Dice scores. On the CHAOS-T2 dataset, it demonstrated excellent performance in zero-shot experiments and significant improvement in few-shot experiments.

大部分用于辐射剂量学研究的辐照器都安装比活度较高的放射源，这类放射源只能采用合规的容器运输以完成现场装源。为了使国产辐照器能够更好地符合国内外放射源的运输及安装要求，研制了一种新型三重屏蔽辐照器，用于进行现场装源及开展后续工作。首先基于对辐照器的精确构建，开展了系统的模拟计算，分析了辐照器对射束的控制特性。然后结合模拟计算和分析，研究了开展辐射剂量学相关研究所关心的辐射场性能。本工作研制的新型三重屏蔽辐照器适用于现场装源，散射腔能够将射束中的散射成分减少25%。辐照器的三重屏蔽结构能够将常规工作区域的射线强度衰减约7个数量级，据此为辐照器的关键部件安装方案的优化提出了建议。准直器组对辐射野平面内能谱的影响约为0.2%。利用辐照器构建的辐射场计算了三种典型电离室的 60 Co γ空气比释动能绝对测量相关的壁修正因子，与早期发表的结果偏差小于0.2%。在现行要求下，该辐照器可作为支撑辐射剂量学相关工作的一个备选方案，其紧凑的结构可以扩展剂量率的动态范围，从而在相对较长周期提供服务。

Objective.To experimentally determine beam quality correction factors (kQ) for six cylindrical and four parallel-plate ionization chambers (ICs) in both spread-out Bragg peak (SOBP) and single-layer proton beam configurations.Approach.Water calorimetry was implemented to establish absorbed dose to water (Dw) at 10 g cm-2depth for SOBP and single-layer proton beams. IC measurements were performed under identical geometrical conditions as calorimetric measurements, with the exception of water temperature control in the phantom. Systematic evaluation of ion recombination and polarity effects was achieved through sequential measurements at operational voltages of -400 V, -300 V, -200 V, -150 V, and +400 V in scanned proton beams. All chambers were calibrated against the60CoDwstandard at the National Institute of Metrology to obtainDwcalibration coefficients (ND,w). ThekQvalues were determined through integrated water calorimetry and IC measurements.Main results.The relative standard uncertainties inDwdetermination were quantified as 0.43% for SOBP beams and 0.51% for single-layer beams. The experimentally determinedkQvalues demonstrated agreement with both TRS-398 reference data and published literature within declared measurement uncertainties.Significance.This work presents the first comprehensive determination ofkQfactors for SOBP and single-layer proton beams using water calorimetry. The obtainedkQvalues with reduced uncertainties (0.56%-0.63%) establish metrological traceability for ten clinical IC models, directly enhancing the accuracy of scanned proton beam dosimetry in radiotherapy practice.

Purpose:This study aims to compare the technical characteristics of TomoDirect (TD) radiotherapy and TomoHelical (HT) radiotherapy in total skin irradiation (TSI) applications. We conducted a comprehensive evaluation of dosimetric parameters and delivery efficiency in TD-based treatment planning to establish clinical guidelines for modality selection in mycosis fungoides. Materials and methods:This retrospective study analyzed eight mycosis fungoides patients treated with TSI between June 2020 and June 2023, utilizing a 5-mm-thick diving suit bolus to enhance the skin dose distribution with a prescription of 24 Gy delivered in 20 fractions (five fractions/week). Thermoplastic masks (3 mm in thickness) were used for head/neck and thorax/abdomen region immobilization, while the lower limbs were immobilized in a vacuum cushion. Comparative treatment planning employed both TD and HT techniques, with TD plans utilizing 7, 9, and 11 equally spaced coplanar beams (0°starting angle). Ring0, Ring1, Ring2, Ring3, and Ring4, which were 1-cm thick away from the planning target volume (PTV) at distances of 0, 1, 2, 3, and 4 cm, and other normal tissues (NT) were generated. The auxiliary structures were completely blocked during planning. The other plan parameters remained consistent. Plan quality assessment compared the target mean dose (PTVmean), homogeneity index (HI), conformity index (CI), and organ-at-risk (OAR) doses between techniques, with additional evaluation of treatment delivery efficiency through time comparisons. Results:When using NT, Ring4, and Ring3 auxiliary structures in complete-block mode, TD plans with more than nine beams demonstrate comparable PTVmean, HI, and CI-to-HT plans, whereas TD plans of less than nine beams exhibit inferior target coverage. Neither HT nor TD plans meet the clinical requirements when Ring2, Ring1, or Ring0 structures are fully blocked. Regarding OAR sparing, nine-beam TD and HT plans show equivalent maximum doses to optical structures (lenses, optic nerves, and chiasm) and mean doses to other OARs (oral cavity, salivary glands, lungs, heart, liver, and kidneys) with NT/Ring4/Ring3 blocking. However, both techniques fail to satisfy the OAR constraints when Ring2/Ring1/Ring0 are blocked. Treatment delivery times remain similar between modalities with NT/Ring4/Ring3 blocking, but the efficiency significantly decreases for both when deeper structures (Ring2/Ring1/Ring0) are included in the blocking protocol. Conclusion:When employing complete-block mode for NT, Ring4, and Ring3 structures, TD plans utilizing more than nine beams demonstrate comparable dosimetric performance to HT plans in terms of target coverage, OAR sparing, and treatment delivery efficiency. However, both modalities fail to meet the clinical dosimetric requirements when deeper-seated structures (Ring2/Ring1/Ring0) are included in the blocking protocol.

BACKGROUND:The clinical use of flattening filter free (FFF) radiotherapy has significantly increased in recent years due to its effective enhancement of dose rates and reduction of scatter dose. A proposal has been made to adjust the incident electron angle of the accelerator to expand the application of FFF beams in areas such as large planning target volumes (PTVs). However, the inherent softening characteristics and non-uniformity of lateral dose distribution in FFF beams inevitably lead to increased dosimetry errors, especially for ionization chambers widely used in clinical practice, which may result in serious accidents during FFF radiotherapy. PURPOSE:This study constructs a comprehensive Monte Carlo model that encompasses not only conventional FFF beams but also incorporates FFF beams with varying incident electron angles, to investigate dosimetry errors and correction methods in FFF radiotherapy. METHODS:We have innovatively introduced a FFF output correction factor ( k Q F F F , Q W F F ${k}_{{Q}_{FFF},{Q}_{WFF}}$ ) to address dosimetry errors in various ionization chambers under different incident electron angle conditions in FFF beams. The primary variations in k Q F F F , Q W F F ${k}_{{Q}_{FFF},{Q}_{WFF}}$ were analytically determined to result from changes in s w , a i r ${s}_{w,air}$ and the perturbation correction terms of the ionization chamber. RESULTS:Ionization chambers with smaller sensitive volumes typically exhibit reduced dosimetry errors. Our findings indicate that for ionization chambers with sensitive volumes ranging from 0.016  to 0.125 cm3, the dosimetry error under various FFF beam conditions consistently remains below 1.15%. This study provides crucial guidance for selecting appropriate ionization chambers in FFF radiotherapy. CONCLUSION:A correlation was established between the absorbed dose to water in beams with a flattening filter (WFF) and those without (FFF), defined by the FFF output factor ( O F Q F F F , Q W F F $O{F}_{{Q}_{FFF},{Q}_{WFF}}$ ). Using the proposed Monte Carlo model, the O F Q F F F , Q W F F $O{F}_{{Q}_{FFF},{Q}_{WFF}}$ can be derived and applied to theoretically calculate the absorbed dose to water in FFF beams at varying incident electron angles, with a relative standard uncertainty of 0.2. This study provides a valuable reference for clinical dose measurements and crucial support for establishing dose calibration standards in FFF radiotherapy.

为测量小野输出因子,采用国际原子能机构(IAEA)出版的TRS483报告方法,测量了 Elekta Synergy直线加速器标称6 MV、10 MV辐射场的组织模体比(TPR20,10(10)),6 MV、10 MV能量TPR20,10(10)分别为0.683和0.735.通过计算电离室适用的最小半高宽验证了多种电离室可测射野范围,选用的电离室可测最小半高宽在3～4 cm之间.对探测器灵敏体积、测量剂量和剂量率线性、漏电流、重复性和稳定性进行比较,选择了 18种不同型号共21支探测器,在加速器TPR20,10(10)为0.683和0.735的辐射场,源皮距(SSD)分别为90 cm和100 cm的条件下计算1 cm×1 cm,2 cm×2cm,3 cm×3cm,4cm×4cm,5 cm×5cm 和8cm×8cm方野与 10cm×10cm 方野的探测器电荷比值得到未修正的射野输出因子,乘以TRS-483报告的修正系数后得到修正射野输出因子,修正后的射野输出因子与平均值最大差异小于2.5％.结果表明:使用TRS-483报告的修正因子可提高不同探测器测量小野剂量的一致性.

Objective:To study the influence of intensive magnet fields on radiation dose measurement, and to demonstrate the feasibility of measuring magnet field correction factor by a combination of medical linac with variable magnet fields in view of needing for accurate measurement of the doses from reference beam arising in MR image-guided radiotherapy.Methods:A photon radiation field and a variable field with 6 MV nominal high voltage were produced by using conventional medical electron linear accelerator equipped with a pair of electromagnets with magnetic field strength up to 1.5 T. Both PTW30013 and PTW31010 ionization chambers were used to test the responses of ionization chambers under different magnetic field strengths at four orientations in which the angles between ionization chamber axis and magnetic field direction were 0°, 180°, 90° and 270°, respectively. The magnetic factors, kB, M was calculated and compared with the reported values in literature. Results:The response of ionization chamber was proportional to the magnetic field strength before it reached to a peak around 1 T, and then fell down as the magnetic field continued to rise. When the magnetic field was 0.35 T, the magnetic factors of PTW31010 were 0.988 2±0.000 3 and 0.997 4±0.000 4 corresponding to 90° and 0° directions, the discrepancy between 0° scenario and literature was 0.05% ± 0.04%. When the magnetic field reached 1.5 T, the magnetic factor of PTW30013 was 0.958 9±0.000 5 at the situation of 90°, which was 0.60% ± 0.05% different from the literature value.Conclusions:Conventional 6 MV medical accelerator equipped with electromagnet can be used to measure the magnetic field factor of reference dosimetry for MRIgRT.

Several new glass vessels, thermistor probes, and water phantoms have been designed and built at the National Institute of Metrology (China) to upgrade and develop the existing water calorimeter. The increased plane-parallel vessels have shorter thermal stability times and shallower positioning depths (∼1.3 cm) than the previous cylindrical vessels, which makes them suitable for electron beams. The sensitivity of the new probes is 10% greater than the previous ones. In this study, detailed experimental and theoretical investigations of various factors affecting the new water calorimeter are performed. The system uncertainty of the water calorimeter is reduced and the robustness of the determination of the absorbed-dose-to-water D w is improved using a variety of geometric detector vessels and two kinds of high-purity water systems saturated with high-purity gases. This new calorimeter is employed as a primary standard for determining the D w , has achieved a combined standard uncertainty of 0.24% for a 60 Co beam, 0.27% for 6 MV and 10 MV photon beams and 0.30% for a 25 MV photon beam. The beam quality conversion factors k Q of ten cylindrical and three plane-parallel ionization chambers are measured using the new calorimeter to improve the reference dosimetry accuracy of high-energy clinical photon beams.

目的:探讨建立一种放射治疗全身器官剂量数据库平台的可行性.方法:使用基于深度学习的自动勾画软件DeepViewer?在1例食管癌患者的全身CT上勾画全身器官,然后利用基于GPU加速的蒙特卡罗软件ARCHER计算相应的器官剂量分布,最后利用Lyman-Kutcher-Burman(LKB)模型评估放疗患者正常组织并发症概率(NTCP).结果:针对该病例,成功建立基于DeepViewer?、ARCHER和LKB模型的全身器官剂量数据库,发现距离靶区越近的器官剂量越大,其中心脏与靶区间距离最小,剂量为14.11 Gy,但因其模型参数特殊,通过LKB模型计算的NTCP为0.00％;左、右肺的剂量分别为3.19和1.16 Gy,但是NTCP值却很大,分别为2.13％和1.60％.对于距离靶区较远的头颈部器官(视交叉、视神经和眼)和腹部器官(直肠、膀胱和股骨头)剂量分别约为9和2 mGy,并且NTCP均近似为0.00％.结论:研究结果证明通过自动勾画软件DeepViewer?、蒙特卡罗软件ARCHER和LKB模型建立全身器官剂量数据库的可行性.

Laser-induced periodic surface structures (LIPSSs) are a universal phenomenon that can be observed on a variety of materials, including metals, semiconductors, and dielectrics, upon irradiation with ultrafast laser pulses. It has found various potential applications in the fields of optics, biologics, and mechatronics due to its efficient and flexible fabrication process and subwavelength quasi-periodic property. However, LIPSSs face the challenge of uniformity control because the formation of micro-/nanostructures induced by ultrafast laser is a complex process involving multiple interacting factors, including laser energy deposition, phase change, light scattering, and instantaneous local changes of material properties and their feedback mechanisms. Recently, there has been some significant progress regarding the control of LIPSS uniformity. In this work, we review recent experimental and methodological advances on this topic from three aspects: 1) laser-induced modified-LIPSS, 2) feedback mechanism of LIPSS formation, and 3) ultrafast laser pulse shaping. This review can stimulate further investigations into the uniformity control of LIPSSs to support and accelerate the industrial applications of uniform LIPSSs.

Proton radiotherapy has gradually become a precision radiotherapy technique owing to the characteristic of Bragg Peak on the depth-dose distribution. This paper introduces the details of three proton beam reference dosimetry methods as well as the corresponding limitations in clinical proton modalities. Further discussions on the correction terms and improvement methods of measurements combined with Monte Carlo techniques have been proposed. Finally, the state-of-the-art determination on microdosimetry of proton beams has been summarized, which provides a reference for research on proton beam water absorption dose measurement.

Flash放射治疗(Flash-RT)具有独特的放射生物学特性及潜在临床优势,已成为放射治疗领域的研究热点,但目前关于Flash-RT原理及临床转化等研究仍处于初步阶段.本文对Flash-RT相关研究进展进行综述.

Linear energy transfer (LET), a key parameter of relative biological effectiveness (RBE) in proton therapy, is not easy to measure or simulate in a standardized protocol. A multi-centric analysis of dose-averaged LET (LETd) and track-averaged LET (LETt) including individual particle contributions, scoring slab thickness, inhomogeneous medium and clinical beam configurations are investigated using the Monte Carlo code TOPAS. Primary and secondary protons are scored separately within the simulation. It is found that the primary protons are the major contribution to LET at the dose plateau and Bragg Peak (BP) regions, whilst the secondary protons have complete contribution to the tail-LET beyond the BP. The calculated LETt is always lower than LETd, nearly a factor of two lower in the region distal to the BP. Varying the scoring slab thickness shows a negligible influence on LETt, whereas, there is up to 26% discrepancy in LETd at 5-cm depth with thicknesses varying from 0.1 mm to 2 mm for 153.3 MeV proton beam. Moreover, smaller scoring thickness of 0.1 mm results in large fluctuations for tail LETd. LETd distributions with 3-cm thick bone-and lung-slab at the entrance of water phantom against primary and secondary protons' contribution are derived. A small trough appears at the position of inserted inhomogeneous material and large spikes which could account for the changes of cross section in nuclear interactions by secondary protons display on the tail of LETd curve. Regarding the modulated beams, substantial-high LET values are obtained at both-sides along the beam path which should gain more attention when calculating LET in clinical applications. In conclusion, the selection of Monte Carlo simulation schemes indeed affects the calculated LET values, more procedures should be considered when building bridges between LET and radiological effectiveness.

Mechanistic in silico models can provide insight into biological mechanisms and highlight uncertainties for experimental investigation. Radiation-induced double-strand breaks (DSBs) are known to be toxic lesions if not repaired correctly. Non-homologous end joining (NHEJ) is the major DSB-repair pathway available throughout the cell cycle and, recently, has been hypothesised to consist of a fast and slow component in G0/G1. The slow component has been shown to be resection-dependent, requiring the nuclease Artemis to function. However, the pathway is not yet fully understood. This study compares two hypothesised models, simulating the action of individual repair proteins on DSB ends in a step-by-step manner, enabling the modelling of both wild-type and protein-deficient cell systems. Performance is benchmarked against experimental data from 21 cell lines and 18 radiation qualities. A model where resection-dependent and independent pathways are entirely separated can only reproduce experimental repair kinetics with additional restraints on end motion and protein recruitment. However, a model where the pathways are entwined was found to effectively fit without needing additional mechanisms. It has been shown that DaMaRiS is a useful tool when analysing the connections between resection-dependent and independent NHEJ repair pathways and robustly matches with experimental results from several sources.

Purpose: The present work aimed to evaluate organ doses and related risk for cancer from external beam radiation treatment (EBRT) and high-dose-rate (HDR) brachytherapy (BT) involving Co-60 source for patients with cervical carcinoma in Tanzania based on Monte Carlo methods and to evaluate the secondary cancer risks in their lifetime. Methods: EBRT and HDR-BR were modelled by using the MCNPX Monte Carlo (MC) code. The MC simulations were performed by using validated models and isocentric irradiation of an adult female computational phantom. The organ doses and cancer risks estimates were obtained. Results: The highest absorbed doses of 6.98 x 10(-2) and 5.74 x 10(-2) Sv/Gy were recorded in the bladder for BT and EBRT. The higher risk was found for colon at 1.06 x 10(-3) in the HDR-BT and 9.75 x 10(-5) in the EBRT per 100,000 population at exposure age of 35 years than in the other organs. The risk magnitude decreased with increasing age at exposure. In general, the secondary cancer risks in all sites considered from EBRT and HDR-BR for cervical cancer patient were lower than the baseline risks. Conclusions: The chances of developing secondary cancer take years following radiation therapy are extremely low, but the results of present study can support to establish a future database on secondary cancer risks involving radiation therapy in patients with cervical cancer by using HDR-BR and EBRT with Co-60 source in Tanzania and other developing countries.

A cloud-based software, VirtualDose-IR (Virtual Phantoms Inc., Albany, New York, USA), designed to report organ doses and effective doses for a diverse patient population from interventional radiology (IR) procedures has been developed and tested. This software is based on a comprehensive database of Monte Carlo-generated organ dose built with a set of 21 anatomically realistic patient phantoms. The patient types included in this database are both male and female people with different ages reflecting reference adults, obese people with different BMIs and pregnant women at different gestational stages. Selectable parameters such as patient type, tube voltage, filtration thickness, beam direction, field size, and irradiation site are also considered in VirtualDose-IR. The software has been implemented using the 'Software as a Service (SaaS)' delivery concept permitting simultaneous multi-user, multi-platform access without requiring local installation. The patient doses resulting from different target sites and patient populations were reported using the VirtualDose-IR system. The patient doses under different source to surface distances (SSD) and beam angles calculated by VirtualDose-IR and Monte Carlo simulations were compared. For most organs, the dose differences between VirtualDose-IR results and Monte Carlo results were less than 0.3 mGy at 15 000 mGy * cm2 kerma-area product (KAP). The organ dose results were compared with measurement data previously reported in literatures. The doses to organs that were located within the irradiation field match closely with experimental measurement data. The differences in the effective dose values between calculated using VirtualDose-IR and those measured were less than 2.5%. The dose errors of most organs between VirtualDose-IR and literature results were less than 40%. These results validate the accuracy of organ doses reported by VirtualDose-IR. With the inclusion of pre-specified clinical IR examination parameters (such as beam direction, target location, field of view and beam quality) and the latest anatomically realistic patient phantoms in Monte Carlo simulations, VirtualDose-IR provides users with accurate dose information in order to systematically compare, evaluate, and optimize IR plans.