Irradiation Position Research Articles

Laser-induced nucleation of urea through the control of Insoluble Impurity

The mechanism of non-photochemical laser-induced nucleation (NPLIN) was investigated through the crystallization of urea crystals in supersaturated (151%) aqueous solutions. To detect the role of impurities in NPLIN, the effect of filtration, doping and laser irradiation position on nucleation probability were studied, respectively. As particles larger than the filter pore size in the solution were almost removed by syringe filter with poly (ether sulfone) membrane, the NPLIN probability was evidently suppressed by filtration when the pore sizes of filter were used from 1 μm to 0.45 μm. The inhibition of NPLIN after filtration could be reversed to varying degrees by adding several kinds and concentrations of impurities into the filtered solution; as the solid particles were extra added, age after cooling for samples was no longer necessary. The increase in the NPLIN probability with the irradiation height decreases was observed when samples were irradiated at different vertical positions within the sample vial. The experimental results were analyzed with reference to the known mechanisms. As nucleation probability through NPLIN can be controlled by pore size of syringe filter, doping or laser irradiation position, several functions were established to analyze the nucleation probability distribution under the effect of these three factors. These experimental results were discussed with reference to the known mechanisms proposed for NPLIN.

Three-dimensional radiation dosimetry of carbon ion beams using surfactant hydrogels: Fundamental investigation.

In carbon ion radiotherapy, accurate measurement of the three-dimensional (3D) absorbed dose distribution is critical for effectively targeting tumors. Although micellar gel dosimeters exhibit considerable potential for measuring 3D absorbed dose distributions, few studies have focused on radiotherapy using carbon ion beams. This study investigated the applicability of the surfactant hydrogel dosimeter (SHD), a micellar gel dosimeter, to measuring a 3D dose absorbed through carbon ion beam irradiation. A cubic target region of 34mm per side was established at a depth of 46mm below the upper surface of an SHD specimen. Scanning irradiation was performed using a pencil beam of carbon ions at the Ion-beam Radiation Oncology Center in Kanagawa ("i-ROCK"), Japan, under irradiation conditions set by the treatment planning system ("Monaco for Carbon", Ver. 5.20, Elekta AB, Sweden) to create a spread-out Bragg peak within the target. The physical dose was set to 10Gy at the isocenter, situated at the center of the target. The SHD responsiveness was measured twice using optical computed tomography (CT) ("Vista 15", Modus Medical Devices, Canada) for three irradiated specimens, and six types of measured optical attenuation coefficient (OAC) were obtained. To assess whether the OAC represented the absorbed dose expected in the treatment plan, we compared the relative distribution of the OAC and that of the absorbed dose. Relative fraction (RF) was used to measure the difference between the relative value of the OAC and that of the absorbed dose. Moreover, the distribution of OH radical (•OH) concentration obtained by Monte Carlo simulation ("PHITS" ver. 3.24 JAEA, Japan) and that of the OAC were compared. In the direction of beam travel, the relative distribution of the OAC was lower than that of the absorbed dose. This discrepancy could be attributed to a decrease in the concentration of •OH produced by irradiation owing to the recombination reaction, which does not accurately reflect the absorbed dose. By contrast, the distributions in the plane perpendicular to the beam travel were consistent. The RF increased from±3% to±13% along the beam travel direction. The small RF in the plane perpendicular to the beam travel could be attributed to the constant distribution of linear energy transfer, regardless of the irradiation position, and the generation of radicals proportionally to the absorbed dose. The increase in RF along the beam travel direction was ascribed to ring artifacts in the irradiated region. The measurement of the absorbed dose distribution in the beam travel direction should be improved. The observed discrepancy is attributed to the reduced reactivity of the SHD due to a high liner energy transfer near the Bragg peak. However, the absorbed dose distribution can be effectively evaluated in the plane perpendicular to the direction of beam travel.

Robot-Assisted Ocular Tumour Radiotherapy Positioning and Tracking System.

Precise dose position distribution is crucial for ocular proton therapy. A non-invasive eye positioning and tracking system with novel structure is designed to reduce eye movement and facilitate precise dose by guiding the direction of patients' gaze. The system helps to achieve gaze guidance by controlling the light source fixed on two turntables above the patient's face. Tracking of the eye is achieved by cameras attached to the end of a 6DOFs robotic arm to capture the image reflected from a mirror above the patient's face. After all operation steps, the accuracy of the robotic arm is 0.18mm (SD 0.25mm) and the accuracy of the turntables is 0.01° (SD 0.02°). The EPTS is tested to be remotely controlled in real time with sufficient precision and repeatability. The system is expected to improve the safety and efficiency of ocular proton therapy.

Research on the comprehensive child life intervention program (CCLIP) for adjusting medical fear in children with central nervous system (CNS) cancers: a randomized controlled trial study protocol

BackgroundMedical fear is a common psychological reaction in hospitalized children, especially during radiotherapy for central nervous system (CNS) cancers. This fear not only causes negative emotions such as anxiety and depression but also affects children’s quality of life and treatment outcomes. It is exacerbated by factors such as unfamiliar environments during radiation therapy and separation from parents. Child Life, as a professional service, offers physical and mental support to children through medical understanding and psychological preparation, addressing their social and psychological needs, among other things. This study aims to construct a comprehensive Child Life intervention program (CCLIP), consisting of four key components: psychological adjustment and preparation, therapeutic play, pain management and coping strategies, and family support. The integration of effective intervention methods aims to reduce medical fear in children undergoing radiotherapy, promote psychological well-being, improve treatment compliance, and enhance quality of life.MethodsThis study is a protocol for a randomized controlled trial. Using a random number table method, we plan to recruit 38 eligible children who meet the inclusion criteria and then randomize them into two distinct groups: the intervention group and the control group. The intervention group will receive the CCLIP, and the control group will receive standardized care. Data will be collected through questionnaires and on-site assessments during the one-month intervention period at four distinct time points: the day of admission (T0), the first radiotherapy positioning (T1), mid-radiotherapy (T2), and postradiotherapy (T3). The primary outcome measure is the effectiveness of the CCLIP in reducing medical fear among children receiving radiation treatment for CNS cancers. Secondary outcomes include anxiety, depression, radiation adherence, quality of life among children, and parental satisfaction.DiscussionThis study aims to alleviate medical fear among children with CNS tumors undergoing radiotherapy through the implementation of the CCLIP while enhancing their mental health and quality of life. The expected outcomes of this research include providing effective intervention strategies for clinical practice, improving the treatment experience and long-term prognosis of children, and having positive impacts on children and their families.Trial registrationThis study is registered at the Chinese Clinical Trial Registry, ChiCTR2400082622. Registered 2 April, 2024.

Progress on Pu-238 production at Idaho National Laboratory from February 2022 to July 2023

Idaho National Laboratory (INL) has continued to qualify irradiation positions in the Advanced Test Reactor (ATR) for Pu-238 production to support NASA deep space missions. Over the past year, INL qualified Np-237 targets for ATR’s North East Flux Trap (NEFT), Inner-A and H positions. Work has begun to requalify the South Flux Trap (SFT) and to qualify the East Flux Trap (EFT) for the ATR GEN I target and is midway through the qualification process. This paper gives an overview of operational and technical activities from February 2022 to July 2023.

Characterization of Neutron Irradiator as a Source of Reference Radiation Field for Calibrating Dosemeters and Doserate Meters at PSI Laboratory

A new neutron calibration laboratory has been installed at the Paul Scherrer Institute in Switzerland. The calibration laboratory has been equipped with a newly developed neutron irradiator with two calibration benches, remote control instruments and related ancillary equipment for calibrating dosemeters and doserate meters. The actual dimensions of the calibration laboratory are 2.0 m (H) X 6.8 m (W) X 12.6 m (L). On the steel grid at a height of 2 m from the basement floor, two calibration benches are installed. A transport channel is installed in the middle of the benches for the transfer of the radiation sources. The radiation sources are moved from the safe position of the irradiator to the reference irradiation position using an air pressure unit. The reference position is at a height of 1.2 m from the grid floor. The neutron irradiator is equipped with two Am-Be sources. Characterization of neutron radiation field has been calculated in detail by the MCNPX neutron transport code as well as energy distribution of neutrons and contribution of scattered neutrons. Experimentally, it was measured with a neutron/gamma digital spectrometric system equipped with a stilbene detector. The quality of the neutron radiation field has been characterized by ambient dose equivalent rate and the shape of the Am-Be spectra has been verified with the ISO-8529 standard.

Photo/thermal dual-responsive azobenzene-based photosensitive resin for 4D printing

4D printing, combining the advantages of 3D printing and stimuli-responsive materials, provides a precise and rapid fabrication method for complex-shaped smart objects. In this study, the photoisomerization characteristic of azobenzene is used to develop 4D printable resins composed of azobenzene-based acrylates (AZO) and other acrylate compounds, which can be UV-cured and 3D printed into objects with photo and thermal dual responsiveness. UV-curing kinetics reveal that AZO competes with the photoinitiator for photons during photopolymerization, reducing the generation of reactive oxygen species and subsequently affecting the mechanical properties of UV-cured resin. The optimum content of AZO in 4D printing resins is 0.5 wt%, producing 3D printed objects with excellent mechanical properties, including a maximum stress of 25.2 MPa and a strain of 100 %. This ensures the successful formation of complex-shaped objects in the 3D printing process. Moreover, the objects printed with this photosensitive resin demonstrate exceptional shape memory capabilities, achieving a 100 % shape recovery ratio over three cycles of thermal stimulation. The printed openwork spheroid with a concave shape can successfully revert to its original form after 48 s of irradiation with 365 nm UV light. The degree of shape recovery can be precisely controlled by adjusting the UV irradiation time and position. Therefore, these photo/thermal dual-responsive 4D objects show great application prospects in medical devices and smart materials.

An efficient protocol for commissioning radiophotoluminescence dosimeters for radiotherapy dosimetry audits

PurposeThe aim of this study was to develop an efficient protocol for the commissioning of 1000 radiophotoluminescence dosimeters (RPLDs) for use in postal dosimetry audits in radiotherapy. This involved the determination of correction factors necessary to reduce measurement uncertainty and ensure accurate dose measurements. MethodsThe commissioning process started with the RPLDs subjected to a series of controlled irradiations to determine their individual nominal response. Experiments were also conducted to assess the influence of irradiation position, reading position, and ambient temperature on the dosimeter readings all which were accounted for calculating individual sensitivity correction factors (SCFs) for each dosimeter. Statistical analysis was performed to evaluate the variability of SCFs depending on normalization group. An additional investigation simulating different dosimetry audit batches was conducted to study the effect of SCF variability on dosimetry audit measurements. ResultsThe adopted commissioning protocol required irradiation position correction factors (0.990–0.996), readout tray position correction factors (0.992–1.01) and room temperature corrections (∼0.4 % per ° C). This enabled the calculation of SCFs for a batch of 1000 RPLDs and the analysis found the majority of SCFs falling within the range of 0.985–1.015. The standard deviations of the SCF distributions were approximately 1% for all normalization groups. It was observed that SCFs normalized to the entire batch of 1000 dosimeters could be effectively used for smaller audit batches, with an additional uncertainty contribution of up to 0.2%. This minimal increase in uncertainty is acceptable within the context of dosimetry audits. ConclusionsThe developed protocol for commissioning RPLDs provides a reliable method for ensuring accurate dose measurements in postal radiotherapy dosimetry audits. The correction factors applied during the commissioning process were thoroughly described to effectively minimize measurement uncertainty. The findings support the use of SCFs normalized to large dosimeter batches for smaller audit groups, thereby streamlining the dosimetry audit process. Future research should focus on the long-term stability of SCFs to further enhance the reliability of RPLD-based dosimetry audits.

Local augmentation of phonon transport at GaInN/GaN heterointerface by introducing a graded variation of InN mole fraction

The pump and probe technique in Raman spectroscopy of the E2 (high) mode is exploited to uncover the enhancing factor of the phonon transport across Ga1−xInxN/GaN interfaces. Two samples are investigated: one with a uniform x of 0.09 and another one with a graded variation in x from 0.17 to 0 along the depth direction. Lateral phonon transport is obtained by scanning the 532-nm probing laser from the irradiation position of the 325-nm heating laser. No difference in the lateral diffusion length is observed between the two samples, while the transport probability across the interface is higher for the sample with the graded variation in x than the sample with the uniform x of 0.09. The microscopic images of the decrease in the mode energy or the increase in temperature of the GaN layer reveal that the local phonon transport across the heterointerface is enhanced in regions with low differences in the phonon mode energy between the GaN and GaInN rather than the difference in crystal quality.

The Current Position of Postoperative Radiotherapy for Salivary Gland Cancer: A Systematic Review and Meta-Analysis.

Because of the rarity, heterogeneous histology, and diverse anatomical sites of salivary gland cancer (SGC), there are a limited number of clinical studies on its management. This study reports the cumulative evidence of postoperative radiotherapy (PORT) for SGC of the head and neck. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, Embase, Cochrane Library, and Web of Science databases between 7th and 10th November 2023. A total of 2962 patients from 26 studies between 2007 and 2023 were included in this meta-analysis. The median RT dose was 64 Gy (range: 56-66 Gy). The median proportions of high-grade, pathological tumor stage 3 or 4 and pathological lymph node involvement were 42% (0-100%), 40% (0-77%), and 31% (0-75%). The pooled locoregional control rates at 3, 5, and 10 years were 92% (95% confidence interval [CI], 89-94%), 89% (95% CI, 86-93%), and 84% (95% CI, 73-92%), respectively. The pooled disease-free survival (DFS) rates at 3, 5, and 10 years were 77% (95% CI, 70-83%), 67% (95% CI, 60-74%), and 61% (95% CI, 55-67%), respectively. The pooled overall survival rates at 3, 5, and 10 years were 84% (95% CI, 79-88%), 75% (95% CI, 72-79%), and 68% (95% CI, 62-74%), respectively. Severe late toxicity ≥ grade 3 occurred in 7% (95% CI, 3-14%). PORT showed favorable long-term efficacy and safety in SGC, especially for patients with high-grade histology. Considering that DFS continued to decrease, further clinical trials exploring treatment intensification are warranted.

Advances in research on organ-at-risk protection in pelvic tumor external beam radiotherapy

The simultaneous objectives of destroying tumor cells while protecting normal pelvic organs present a dual clinical and technical challenge within the realm of pelvic tumor radiotherapy. This article reviews the latest literatures, focusing on technological innovations in key aspects of radiotherapy such as positioning, planning, and delivery. These include positioning fixation techniques, organ-at-risk avoidance irradiation, non-coplanar irradiation techniques, as well as organ displacement protection and image-guided adaptive techniques. It summarizes and discusses the research progress made in the protection of critical organs during pelvic tumor radiotherapy. The paper emphasizes technological advancements in the protection of critical organs throughout the processes of radiotherapy positioning, planning, and implementation, aiming to provide references for further research on the protection of critical organs in the external irradiation treatment of pelvic tumors.

Efficient production and purification of 32P radioisotope from sulfur by dry distillation: A practical approach with high radiochemical purity

The 32P radioisotope, with a half-life of 14.3 days and an energy level of 1.71 MeV, has diverse applications in medicine and research. Consequently, producing a carrier-free 32P radioisotope characterized by high radiochemical and radionuclide purity is imperative. Two primary methods for generating 32P radioisotopes exist: irradiating phosphorus through the nuclear reaction (n,γ) or irradiating sulfur through the nuclear reaction (n,p). Using sulfur as a target material provides several advantages. Besides the fact that the chemical element produced after irradiation (32P) differs from the irradiated element (32S), it also produces a32P radioisotope with a higher specific activity than using 31P as the target. The production of the radioisotope 32P from sulfur employs the dry distillation method, capitalizing on sulfur's easily sublimated nature. The volatility of sulfur when heated makes it easy to separate the resulting sulfur and radioisotope 32P without the need for additional reagents. This research aims to establish a practical method for producing the 32P radioisotope using the dry distillation technique. The dry distillation method utilizes a quartz ampoule containing a mixture of 32P and 35S radionuclides, a distillation tube wrapped with heating tape, and a condenser to collect the distilled sulfur. Sulfur, serving as the target material, undergoes irradiation in the reactor at the Central Irradiation Position (CIP) through the 32S(n,p)32P nuclear reaction with a fast neutron flux of 5.380 × 1013 n/cm2.sec. Separation is achieved through distillation at a temperature of 440 °C. The residual separation products are then dissolved in a 0.1 N HCl solution. The purification process involves using an AG50 WX8 cation exchange resin column, which is pre-conditioned with 0.1 N HCl. The resulting eluate contains the 32P radioisotope. The radiochemical purity of the 32P radioisotope is analyzed using thin-layer chromatography (TLC). In this analysis, a PEI Cellulose plate serves as the stationary phase, and a KH2PO4 solution acts as the mobile phase. This vacuum-free distillation method successfully separates the 32P radioisotope from sulfur, achieving a separation efficiency of 55.1 ± 9.9% (n = 7). The average activity produced after the purification process is 5.690E+10 Bq. Purifying the 32P radioisotope results in a radiochemical purity of 99.97% at Rf 0.7110, as orthophosphate, the radionuclide purity exceeds 99%.

Analysis of the trigger characteristics for a pseudospark switch triggered by nanosecond focused laser

Clarifying the trigger characteristics of pseudospark switch triggered by laser (backlight thyratron, BLT) is crucial for optimizing the trigger performance under different conditions. This paper investigates the electron and ion emission characteristics of metal irradiated by nanosecond focused laser, and tests the trigger characteristics of BLT triggered from the back of the cathode (CBLT) and the back of anode (ABLT) with different targets (Mg, Ti, Cu, Mo, W), and discusses the trigger mechanism. The trigger characteristics of CBLT depends on the emission of prompt electrons e1 and the expansion of ultrafast electrons e2. When the laser energy ε is less than 0.3 mJ, there will be no e1 emission, and low-density metals (e.g. Mg and Ti) are prone to ablation, resulting in large e2 amplitude and short trigger delay td. Due to the slow speed of e2, td of CBLT has an exponential relationship with the laser irradiation position. When ε is increased to above 1 mJ, different metals can be fully heated, and the emission of e1 will be enhanced and play a major role in trigger. In this case, metals with high melting and boiling points will produce more e1, so the trigger performance of Mg is the worst and W is the best. Due to the fast speed of e1, the sensitivity of td of CBLT triggered by e1 to the laser irradiation position is low, and the trigger lifetime can be improved by fine-tuning the laser irradiation position. The trigger of ABLT depends on the expansion of fast ions i2, and heavy metal ions diffuse easily in the background gas, so the laser irradiation area where ABLT can be stably triggered is larger, and the corresponding trigger performance of ABLT is better.

Development of a phantom for assessing the precision of setup in skin mark-less surface-guided radiotherapy.

Surface-guided radiotherapy (SGRT) is adopted by several institutions; however, reports on the phantoms used to assess the precision of the SGRT setup are limited. The purpose of this study was to develop a phantom to verify the accuracy of the irradiation position during skin mark-less SGRT. An acrylonitrile butadiene styrene (ABS) plastic cube phantom with a diameter of 150mm on each side containing a dummy target of 15mm and two types of body surface-shaped phantoms (breast/face shape) that could be attached to the cube phantom were fabricated. Films can be inserted on four sides of the cubic phantom (left, right, anterior and posterior), and the center of radiation can be calculated by irradiating the dummy target with orthogonal MV beams. Three types of SGRT using a VOXELAN-HEV600M (Electronics Research&Development Corporation, Okayama, Japan) were evaluated using this phantom: (i) SGRTCT-a SGRT set-up based solely on a computed tomography (CT)-reference image. (ii) SGRTCT + CBCT-a method where cone beam computed tomography (CBCT) matching was performed after SGRTCT. (iii) SGRTScan-a resetup technique using a scan reference image obtained after completing the (ii) step. Both the breast and face phantoms were recognized in the SGRT system without problems. SGRTScan ensure precision within 1mm/1° for breast and face verification, respectively. All SGRT methods showed comparable rotational accuracies with no significant disparities. The developed phantom was useful for verifying the accuracy of skin mark-less SGRT position matching. The SGRTScan demonstrated the feasibility of achieving skin-mark less SGRT with high accuracy, with deviations of less than 1mm. Additional research is necessary to evaluate the suitability of the developed phantoms for use in various facilities and systems. This phantom could be used for postal surveys in the future.

Adaptive relative orbit control considering laser ablation uncertainty

This study proposes a relative orbit control law for laser debris removal missions considering the uncertainties of laser ablation and atmospheric drag. A removal spacecraft irradiates laser pulses to a target debris to generate the ablation force for deorbiting. The deorbiting force lowers the target altitude, and the removal spacecraft must follow it to maintain its relative position for continuous laser irradiation. The difficulty stems from uncertainties of the magnitude of laser ablation and external disturbances such as atmospheric drag. To tackle this problem, this study derives an adaptive control method using the Gaussian process regression to cancel the uncertainties with a nonparametric regression model. Numerical simulations verify the proposed control law under the uncertainties of laser ablation and atmospheric drag. The proposed control law can contribute to the realization of a safer and more secure mission not only for laser debris removal missions, but also for other on-orbit services.

A Light-Powered Micropump with Dynamic Collective Behavior for Reparation.

Inspired by the collective behaviors of active systems in nature, the collective behavior of micromotors has attracted more and more attention in recent years. However, little attention has been paid to the collective behavior of the immobilized micromotor, i.e., the micropump. In this paper, a unique pentacene-based micropump is reported, which demonstrates dynamic collective behavior activated by white light irradiation. The light irradiation may generate the photochemical reactions between pentacene and water, leading to the electroosmotic flow. As a result, this micropump is capable of pumping the surrounding solution inward along the substrate surface based on the electroosmosis mechanism. Intriguingly, the inward pumping causes the agglomeration of the tracer particles on the surface of the micropump. In addition, the aggregation can migrate following the change in the light irradiation position between two adjacent micropumps. Based on the aggregating and migrating behaviors of this pentacene-based micropump, we have achieved the conductivity restoration of the cracked circuit.

Ultrafast, self-powered monolithic pressure sensing technology induced by piezo-pyrophototronics

Pressure sensing is a pivotal aspect of modern technology that has been extensively explored, but still presents significant challenges. This work introduces an innovative ultrafast self-powered pressure sensing technology by harnessing the lateral photovoltaic effect (LPE) in a CIGS heterojunction via piezo-pyrophototronics. By utilizing non-uniform irradiation, a surface gradient of charge carriers is induced, resulting in the generation of a lateral photovoltage (LPV) that contributes to the excellent self-powered characteristic of the sensor. This gradient is then coupled with external pressure through the piezo-phototronic effect, enabling the sensing capability of the device. The enhancement of LPV, which is dependent on the irradiation position, power and wavelength, exhibits an extremely linear relationship with the applied external pressure ranging from 0 to 2.0 MPa. Besides, the pyroelectric field generated by transient temperature variations introduces an additional modulation to the pressure sensing effect, leading to an impressive pressure sensitivity of 64.25 mV/MPa, and a rapid response speed of 7.8/8.9 μs. This work highlights the benefits of the lateral photovoltaic effect, piezo-phototronic effect, and pyroelectric modulation in developing highly sensitive and ultrafast self-powered pressure sensors.

UV Light-Mediated Hydrolytic Reaction to Develop Magnetic Hydrogel Actuators with Spatially Distributed Ferriferous Oxide Microparticles.

Magnetic hydrogel actuators are developed by incorporating magnetic fillers into the hydrogel matrix. Regulating the distribution of these fillers is key to the exhibited functionalities but is still challenging. Here a facile way to spatially synthesize ferrosoferric oxide(Fe3O4) microparticles in situ in a thermal-responsive hydrogel is reported. This method involves the photo-reduction of Fe3+ ions coordinated with carboxylate groups in polymer chains, and the hydrolytic reaction of the reduced Fe2+ ions with residual Fe3+ ions. By controlling the irradiation time and position, the concentration of Fe3O4 microparticles can be spatially controlled, and the resulting Fe3O4 pattern enables the hydrogel to exhibit complex locomotion driven by magnet, temperature, and NIR light. This method is convenient and extendable to other hydrogel systems to realize more complicated magneto-responsive functionalities.

Classification of direct optical signal inputs by Ag2S island network reservoir

We have reported that a physical reservoir with a silver sulfide island network can classify simple patterns of an irradiated light without converting it to a voltage signal input. In this study, we conducted experiments to verify whether the detection of dynamical change in an irradiating light, e.g., moving in a reservoir layer, can be available. We also investigated the possibility that the reservoir could detect a position of light exposure, in addition to the dependence on the wavelength and the exposure time. The technique was applied to a task of whether character-shaped light patterns could be recognized even if the irradiated position was changed.

Radiation protection aspects in the design of a Boron Neutron Capture Therapy irradiation room

Boron Neutron Capture Therapy (BNCT) is a radiotherapy whose effect is due to the combination of low-energy neutron irradiation prior chemical targeting of tumour tissues with boron-10. The context of this work is the design of a clinical BNCT facility based on a Radio-Frequency Quadrupole proton accelerator, manufactured by the Italian National Institute of Nuclear Physics (INFN). Such a machine can provide a neutron beam suitable for the treatment of deep-seated tumours when coupled to a beryllium target and a Beam Shaping Assembly whose main constituent is densified lithiated aluminium fluoride. This paper refines the design of the facility, already addressed in preliminary studies, from the point of view of dosimetric quantities in the room and in the patient. The presented calculations have been performed with different Monte Carlo codes, and assess the time evolution of the dose due to the neutron activation of the irradiated materials. A comprehensive evaluation of the dose absorbed in the healthy organs of the patient is provided, with focus on the residual radioactivity of the patient urine, for three different treatment positions. Borated concrete is confirmed to be the best material for constructing the walls of the treatment room. A lead shielding at the beam-port is proposed to reduce the gamma dose at the irradiation position due to the activation of the Beam Shaping Assembly.