Radiation recall phenomenon after administration of the mRNA-1273 SARS-CoV-2 vaccine

Several types of SARS-CoV-2 vaccine have been developed. However, the relationship between SARS-CoV-2 vaccine and radiation therapy (RT) is unclear. Recently, there have been some reports of radiation recall phenomenon (RRP) caused by a SARS-CoV-2 vaccine. We report a case of RRP after administration of the mRNA-1273 SARS-CoV-2 vaccine. A 51-year-old female was diagnosed with breast cancer (cT4N1M0, cStage IIIB) and underwent breast total mastectomy with axillary lymph node dissection after neoadjuvant chemotherapy. After mastectomy, the patient received RT with 50 Gy in 25 fractions. An acute side effect of grade 2 dermatitis according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. occurred after RT. The patient had not started any new systemic medication after RT; however, the patient received the mRNA-1273 SARS-CoV-2 vaccine (Moderna) 1 month after the end of the initial RT. Seven days after vaccination, the patient had a skin reaction with burning sensation and redness. This skin reaction was induced in an area corresponding to the irradiation field of the chest wall. There was no skin reaction in areas other than that described. The reaction was cured within 1 week with topical hydrocortisone. This report is an interesting case report with a RPP after administration of the mRNA-1273 SARS-CoV-2 vaccine.

Progress on neutronic analysis for CFETR

The neutron induced irradiation field is a key problem in fusion reactor related to nuclear responses, shielding design, nuclear safety, and thermo-hydraulic analysis. To support the system design of China Fusion Engineering Test Reactor (CFETR), the comprehensive analysis of irradiation field has been conducted in support of many new developed advanced tools. The paper first summarizes the recent progress on related neutronics code development effort including the geometry conversion tool cosVMPT, Monte Carlo variance reduction technology ‘on-the-fly’ global variance reduction (GVR). Such developed tools have been fully validated and applied on the CFETR nuclear analysis. The neutron irradiation has been evaluated on CFETR Water Cooled Ceramic Breeder (WCCB) blanket, divertor, vacuum vessel, superconductive coils and four kinds of heating systems including the Electron Cyclotron Resonance Heating (ECRH), Ion Cyclotron Resonance Heating (ICRH), Low Hybrid Wave (LHW) and Neutral Beam Injection (NBI). The nuclear responses of tritium breeding ratio (TBR), heating, irradiation damage, Hydrogen/Helium (H/He) production rate of material have been analyzed. In case of neutron damage and overheating deposition on the superconductive coils and Vacuum Vessel (VV), the interface and shielding design among heating systems, blanket and other systems has been initialized. The results show the shielding design can meet the requirement of coil and VV after several iterated neutronics calculation.

Recurrence of Pemphigus Vulgaris after Bilateral Breast Irradiation: A Case Report and Review of the Literature

Pemphigus is a serious and rare chronic bullous autoimmune disease. It is characterized by mucocutaneous erosions secondary to autoantibodies directed against desmogleins 1 and 3, proteins involved in intercellular adhesion mechanisms. The occurrence of pemphigus is based on the triggering of genetic and external environmental factors such as drugs, infection, and more rarely radiotherapy. To date, only 16 cases of radiation-induced pemphigus are described in the context of breast cancer treatment. We present the case of a 76-year-old woman who had a recurrence of pemphigus vulgaris limited to the irradiation field after exposure to an adjuvant radiotherapy treatment for a bilateral triple-negative breast cancer. The onset was bilateral limited to the irradiation area and was treated effectively with local and systemic corticosteroids. After a rigorous review of the literature, only 16 cases of breast cancer radiation-induced pemphigus appeared. In contrast to several cases, the rash was limited to the irradiated area and improved with systemic corticosteroids. For more than three-quarters of the described cases in the literature, pemphigus occurs within 3 months following the end of treatment. After systemic immunosuppressive treatment, this disease disappears in the vast majority of the reported cases.

Development of an irradiation method for superficial tumours using a hydrogel bolus in an accelerator-based BNCT

The aim of this study is the development of an irradiation method for the treatment of superficial tumours using a hydrogel bolus to produce thermal neutrons in accelerator-based Boron Neutron Capture Therapy (BNCT). To evaluate the neutron moderating ability of a hydrogel bolus, a water phantom with a hydrogel bolus was irradiated with an epithermal neutron beam from a cyclotron-based epithermal neutron source. Phantom simulating irradiation to the plantar position was manufactured using three-dimensional printing technology to perform an irradiation test of a hydrogel bolus. Thermal neutron fluxes on the surface of a phantom were evaluated and the results were compared with the Monte Carlo-based Simulation Environment for Radiotherapy Applications (SERA) treatment planning software. It was confirmed that a hydrogel bolus had the same neutron moderating ability as water, and the calculation results from SERA aligned with the measured values within approximately 5%. Furthermore, it was confirmed that the thermal neutron flux decreased at the edge of the irradiation field. It was possible to uniformly irradiate thermal neutrons by increasing the bolus thickness at the edge of the irradiation field, thereby successfully determining uniform dose distribution. An irradiation method for superficial tumours using a hydrogel bolus in the accelerator-based BNCT was established.

Photothermal Conversion of Biodegradable Fluids And Carbon Black Nanofluids

The paper is devoted to the topic of direct absorption solar collectors (DASCs). The main focus is on comparing two kinds of working fluids that can be used in DASCs, namely carbon black nanofluids and biodegradable coffee colloids. At first, the fluids were tested by exposing them to artificial light (indoor experiments) and real solar irradiation (field experiments). The indoor experiments used a system of relatively large geometry, so most of the heat absorption occurred close to the irradiated surface. This resulted in a similar performance by both fluids. The field experiments involved a smaller system, and the light was concentrated by a solar collector. Here the nanofluid outperformed the coffee colloids. Next, the process was analysed using a theoretical analysis that gave good correspondence with the experiments. Finally, we extended the theoretical analysis to a DASC with a flowing fluid. The model was validated against results from the literature, but it also supported our experimental findings.

Palliative radiation treatment used for multiple purposes in a single irradiation field

In this case report, radiation therapy was performed for bilateral hydronephrosis developed during multiple bone metastases of breast cancer and ileus due to peritoneal dissemination. The patient’s preirradiation creatinine level was 8.2 mg/dL, which decreased by the fourth day after starting irradiation therapy. Creatinine level ultimately decreased to 0.6 mg/dL. Pain due to lumbar spine metastasis alleviated and ileus was resolved, allowing the patient to live at home for approximately 5 weeks. The effect of radiotherapy for bilateral hydronephrosis and gastrointestinal obstruction was rapid and good. Palliative radiation treatment can be used for multiple purposes, and in the present patient, we were able to prolong the vital prognosis.

Development of a Quantitative Method Based on the Hill-Shading Technique for Assessing Morphological Changes in the Bone During Image-Guided Radiotherapy for Bone Metastasis

We hypothesized that positioning corrections matching the image in image-guided radiotherapy (IGRT) for bone metastasis contain information on temporal structural changes in irradiated bone metastatic lesions during the treatment period. To extract and quantify these changes, a hill-shading technique was used to emphasize the characteristics of the structure. Spatial frequency components of the bone lesions were described based on hill-shading transformations of the images, and a quantification method was suggested. The matching images of 11 patients who received IGRT for lytic bone metastases were evaluated retrospectively. The hill-shading technique was applied to images of both metastatic lesions and normal bone outside the irradiation field. Outlined bone microstructures were analyzed by a two-dimensional power spectrum using fast Fourier transformation, and the frequency components were quantified. Correlations between the frequency components and cumulative radiation doses were analyzed between the irradiated metastatic bone and normal bone outside the irradiation field. The high-frequency components of the metastatic bone lesion images decreased by a mean of 7% (minimum: -0.2%, maximum: -13.2%) following cumulative irradiation doses of 20-30 Gy versus 0-10 Gy. In the normal bone outside the irradiation field, high-frequency components increased by a mean of 0.07% (minimum: -2.0%, maximum: +4.4%) following irradiation doses of 20-30 Gy versus 0-10 Gy. High-frequency components were significantly different between the normal bone and bone metastases following radiotherapy (p < 0.0001). Hill-shading transformation of matching images obtained during the treatment period enabled adaptation and evaluation of irradiation-induced changes in the microstructure of bone metastatic lesions.

On the Possibility to Use the Charge Imbalance in Patients Undergoing Radiotherapy: A New Online, In Vivo, Noninvasive Dose Monitoring System

This paper describes a new real-time, in vivo, noninvasive, biasless detector system acting as a beam monitoring and relative dose measurement system. The detector is based on the idea that when a beam current is injected into the body of a patient undergoing a charged particle therapy, the current itself can be collected using a conductive electrode in contact with the patient’s skin. This new approach was studied in vitro using an electrically isolated water tank irradiated with monoenergetic proton beams. The conductive electrode was immersed in water and positioned outside the irradiation field. The detection system performance was evaluated by comparing its response against a SEM (Secondary Emission Monitor) detector, used as a reference beam current monitor, and an Advanced Markus ionization chamber. Short-, mid- and long-term reproducibility, current monitoring capability, field size dependence, electrode position and environment temperature dependence, linearity with dose, and dose rate dependence were investigated. Few preliminary in vivo tests were also performed that demonstrated the possibility to apply the system in clinical practice. The potential of the proposed method is considerable, representing a simple and economical system for online, in vivo, and noninvasive monitoring of the beam current and relative released dose into the patient during treatment, without perturbing the irradiation field. The system presented in this work is protected with both a National Italian (N. 102017000087851) and an International N. WO 2019/025933 patent.

Dosimetric characteristics of a thin bolus made with real time variable shape tungsten rubber for photon radiotherapy

In this study, we aim to clarify the dosimetric characteristics of a real time variable shape rubber containing tungsten (STR) as a thin bolus in 6-MV photon radiotherapy. The percentage depth doses (PDDs) and lateral dose profiles (irradiation field = 10 × 10 cm2) in the water-equivalent phantom were measured and compared between no bolus, a conventional 5-mm gel bolus, and 1-, 2-, and 3-mm STR boluses. The characteristics of the PDDs were evaluated according to relative doses at 1 mm depth (D1mm) and depth of maximum dose (dmax). The water-equivalent thicknesses of the STR boluses were determined by shifting the distance of the PDD’s build-up curve until it overlaid that with no bolus. The penumbra size and width of the 50% dose were evaluated using lateral dose profiles. The D1mm with no bolus, 5-mm gel bolus, and 1-, 2-, and 3-mm STR boluses were 47.6%, 91.5%, 86.6%, 89.3%, and 89.4%, respectively, and the respective dmax values were 15, 10, 12, 11, and 10 mm. The water-equivalent thicknesses of the 1-, 2-, and 3-mm STR boluses were 4.4, 4.9, and 5.1 mm, respectively. There were no differences for those in lateral dose profiles. The 1-mm-thick STR thin bolus shifted the depth dose profile by 4.4 mm and could be used as a customized bolus for photon radiotherapy.

Analysis of Dose Load on a Pregnant patient in Radiotherapy of Oropharal Cancer

Purpose: The assessment of the dose load on a pregnant patient during irradiation of the oropharyngeal tumor at different distances from the border of the irradiated field, including at the level corresponding to the position of the fetus, based on phantom measurements.Material and methods: To calculate the exposure plan, the ECLIPSE planning system with the AAA algorithm was used. Irradiation was performed on a LinacClinaciX (Varian, USA) with a nominal photon energy of 6 MeV. The tissue equivalent phantom Alderson–Rando was used to assess the dose load on the fetus.Results and conclusions: It was shown that the total absorbed dose at the level and below the diaphragm (the level of the fetus) at a distance of more than 40 cm from the border of the irradiation field for the entire course of radiation therapy turned out to be significantly less than the permissible limits indicated in the literature and amounted from 41.71 to 14.03 mGy.