Intensity modulated conformal radiotherapy of a jugulo-tympanic paraganglioma

Jugulo-tympanic paragangliomas are rare benign tumors arising from the neuroectodermal cells of the tympanic cavity and the dome of the jugular vein. Surgical resection has long been the first-line treatment. However, when this is not possible, radiotherapy remains a therapeutic alternative allowing local control with less morbidity. We report the case of a patient with an unresectable tympano-jugular paraganglioma, the symptomalagy was dominted by chronic headaches and right sided hypoacousie, and the treatment consisted of external radiation therapy with a total dose of 50 Gy in 25 fractions, one fraction per day, 2 Gy per fraction using the IMRT technique. The evolution was good with disappearance of clinical symptomatology, significant local control with less toxicity.

Consideration of the contribution of the natural background component during individual control of radiation doses to personnel

When ensuring radiation safety in the Russian Federation, there is a principle of separate independent assessment of doses from natural, medical, emergency and technogenic exposure. In practice, it is not always possible to comply with this principled approach. The established dose limits are related only to man-made radiation during normal operation of sources of ionizing radiation. However, during the formation of regional and federal databases on individual doses of personnel exposure, information is entered not on technogenic exposure, but on industrial exposure, that is, without subtracting the natural radiation background. The natural component of the individual dose at low radiation doses is quite significant. Failure to its subtraction leads to an overestimation of the individual dose of external exposure of personnel. Difficulties arise in the implementation of the subtraction of the natural radiation background: 1) in what cases it is necessary to subtract the background, 2) what value to choose for the subtracted background, 3) what method to measure the background, 4) at what stage of processing the measurement information to subtract the background. This article proposes a method for solving the problem of subtracting the natural background radiation from the values of individual doses of external exposure to personnel based on results of individual dosimetric control. Using the example of the city of St. Petersburg, the natural background radiation was measured by the thermoluminescent method of individual dosimetry at 50 control points for three consecutive years (2018-2020). To measure the natural background, we used individual thermoluminescent dosimeters of the same type as those used to measure individual equivalents of external radiation doses to personnel. The choice of using the thermoluminescent method as a predominant one for adjusting the average doses of external radiation from technogenic sources of ionizing radiation when subtracting the natural component of the dose has been substantiated. Comparison of official data on personnel exposure doses with the data obtained as a result of our own measurements is made. Recommendations are given on the use of the obtained values of the average natural radiation background in the formation of regional and federal databases on individual doses of personnel exposure.

The Effect of External Radiotherapy to the Left Ventricle Systolic Function in Locally Advanced Breast Cancer Patients

Background: Locoregional management in breast cancer patients includes surgery and radiation. Radiation increases the risk of the decreasing of cardiac ventricular performance and known as cardiotoxicity. This study aims to analyze the relationship between radiation exposure in locally advanced breast cancer patients with the left ventricular systolic function. Methods: The subjects in this study were patients with locally advanced breast cancer who underwent external radiation therapy after surgery procedure at Dr. Soetomo General Hospital in January 2021 – April 2021. Examination of left ventricular performance parameters was carried out using an invasive method, the transthoracic echocardiography. The performance parameters examined were left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). Results: A total of 45 patients were recruited in this study. Twenty-two patients (22/45; 48.9%) underwent radiation therapy from the left side and 23 patients (23/45; 51.1%) from the right side. After external radiation, the number of patients with left ventricular dilatation were increased. On the left side, there were 6 patients (6/22; 27.6%) who experienced dilatation compared to before radiation (3 patients), while on the right side of the body there were 8 patients (8/22; 34.8%) who experienced dilatation compared to before radiation (6 patients). There was an increase in the number of patients who experienced a decrease in EFT and EFB after radiation, although the association was not significant. Almost all patients experienced a decrease in GLS values ​​after radiation (44/45; 97.8%). Conclusion: There was an increase in the number of patients with left ventricular dilatation and decrease in EFT and EFB values after external radiation. Decreased GLS values ​​were found in almost all patients who underwent external radiation in this study. Keywords: Radiation, locally advanced breast cancer, LVID, ejection fraction, GLS.

Thermoluminescence Analysis of the Clay Core of Bronze Statues: A Re-Appraisal of the Case Studies of Lupa Capitolina and Other Masterpieces in Rome

In this work, we present some new results in applying thermoluminescence (TL) dating to the clay core of bronze statues. This is very important, due to the impossibility of directly dating a metal. Very few cases of indirect dating of clay cores by TL are reported in the literature. We re-considered three cases of dating of clay core from important bronzes in Rome. The parameters to be considered were not easy to calculate in the case of the Lupa Capitolina. However, its traditionally reported Etruscan origin is definitely ruled out, even if the accuracy in the dating is too low to precisely propose a date of the casting. The comparison with radiocarbon results shows good agreement for a Medieval dating. Two other bronze statues were analysed in order to date their casting by TL; a horse from Musei Capitolini resulted to have been cast in the Greek classical period, excluding its casting in the Rome imperial period. A third study shows that, in particularly favourable situations, TL dating of clay core can give rather precise results. This is the case where in the clay core are present materials that behave like good dosimeters, as generally happens in dating ceramics. Furthermore, the possibility of measuring all the parameters influencing the calculation of the dose rate is essential; both the external radiation sources and the radiation reduction by the water content must be taken into account. This was the case of Saint Peter in the Vatican that turned out to be a cast from the beginning of the XIV century.

A Study to Assess Effect of Information Booklet on Knowledge Regarding Side Effect Management in the Patients of Head and Neck Cancer Undergoing External Radiation Therapy in Selected Hospital

Objectives: - To evaluate the effectiveness of informational booklet regarding side effects management in patient undergoing external radiation therapy. Methods: Quasi experimental pre test post test design was used in the study at radiation therapy department in cancer institute. 35 patients of head and neck cancer undergoing external radiation therapy received information booklet regarding side effect management of external radiation therapy in their first week of treatment. Knowledge regarding side effect management of external radiation therapy was assessed one week later. Results: - In pre test there was 51.1% patients with poor knowledge, 48.6% had average knowledge and no one had good knowledge whereas the post test scores are increased by 85.7% with good knowledge, 14.3% had average knowledge and no one had poor knowledge. There is significant difference of knowledge score between pre and post test as P<0.0001 i.e. knowledge score significantly increased after administering information booklet. Sociodemographic variable age, gender, educational status, family income & type of treatment were found to have no association with knowledge score regarding management of side effects. Conclusion: - Radiation therapy is one of the important treatments for cancer but can also cause side effects. These Side effects of radiation therapy are very common and can affect the quality of life of the cancer patients. There was significant impact of information booklet on knowledge regarding side effects management of radiation therapy among head and neck cancer patients. Hence using information booklet as an education material can be helpful in teaching patients self care behaviours, prevent the side effects of radiation therapy and improve the quality of life. Key words: Information booklet, external radiation therapy, head and neck cancer, side effect management.

Smoldering and Flaming of Disc Wood Particles Under External Radiation: Autoignition and Size Effect

Wildfires are global issues that cause severe damages to the society and environment. Wood particles and firebrands are the most common fuels in wildfires, but the size effect on the flaming and smoldering ignitions as well as the subsequent burning behavior is still poorly understood. In this work, a well-controlled experiment was performed to investigate smoldering and flaming ignitions of stationary disc-shaped wood particles with different diameters (25–60 mm) and thicknesses (15–25 mm) under varying radiant heat flux. The ignition difficulty, in terms of the minimum heat flux, increases from smoldering ignition to piloted flaming ignition and then to flaming autoignition. As the sample thickness increases, the minimum heat flux, ignition temperature, and burning duration for flaming autoignition all increase, while the peak burning flux decreases, but they are insensitive to the sample diameter. During ignition and burning processes, the disc particle is deformed due to the interaction between chemical reactions and thermomechanical stresses, especially for smoldering. The characteristic thickness of the smoldering front on wood is also found to be 10–15 mm. This study sheds light on the size effect on the ignition of wood particles by wildfire radiation and helps understand the interaction between flaming and smoldering wildfires.

Management of Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma is a tumor that arises as a result of differentiation of the cholangiocytes and can develop from anywhere in the biliary tree. Subtypes of cholangiocarcinoma are differentiated based on their location in the biliary tree. If diagnosed early these can be resected, but most cases of intrahepatic cholangiocarcinoma present late in the disease course where surgical resection is not an option. In these patients who are poor candidates for resection, a combination of chemotherapy, locoregional therapies like ablation, transarterial chemo and radioembolization, and in very advanced and metastatic disease, external radiation are the available options. These modalities can improve overall disease-free and progression-free survival chances. In this review, we will discuss the risk factors and clinical presentation of intrahepatic cholangiocarcinoma, diagnosis, available therapeutic options, and future directions for management options.

Phase 1 dose-escalation trial using convection-enhanced delivery of radiolabeled monoclonal antibody for diffuse intrinsic pontine glioma following external radiation therapy.

2010 Background: The prognosis of diffuse intrinsic pontine glioma (DIPG) is dire with a median overall survival less than one-year. 124I-omburtamab is a radiolabeled monoclonal antibody that targets B7-H3 epitope. We evaluated the safety of administering escalating doses and volumes of 124I-omburtamab via convection-enhanced delivery (CED) in children with DIPG. Methods: MSKCC 11-011 trial is a standard 3+3 phase 1, open-label, dose escalation study in patients with non-progressive DIPG. CED of 124I-omburtamab was performed between 4-14 weeks post-external radiation therapy. Nine dose levels of a single injection of 124I-omburtamab (Y-mAbs Therapeutics, USA) (range 0.25 to 8.0 mCi; and volume of infusion (Vi) from 250 to 8,000 µl) have been evaluated so far. Patients were assessed weekly for 30 days. Results: 46 children were evaluable for primary and secondary endpoints. The median age at enrolment was 6.5 years (range 2-17). Two patients have experienced AEs CTCAE grade 3 that were categorized as dose limiting toxicities (DLTs), which led to inclusion of three more patients at both the 4 and 6 mCi dose levels. Eight patients have reported transient AEs of grade 3 considered related to 124I-omburtamab. The acute grade 3 AEs were generally indicative of nervous system effects due to volume intolerance or radiation injury, and included hemiparesis (n = 3), dysarthria (n = 3), ataxia (n = 3), dysphagia (n = 2), muscular weakness (n = 2) and gait disturbance (n = 1). There were no related AEs CTCAE grade 4 or 5. Estimations of distribution volumes based on T2-weighted imaging were linearly related to volume with a mean volume of distribution/volume of infusion ratio (Vd/Vi) between 3 and 3.5. The mean ratio of lesion-to-whole body absorbed dose was ̃1000. Median overall survival from diagnosis across all cohorts was 14.8 months (n = 46, 95% CI 11.5, 16.8) and the survival rate estimates (with 95% confidence intervals) at 1, 2, 3 and 5 years were 0.63 (0.46;0.76); 0.13 (0.05;0.26); 0.08 (0.02;0.19); and 0.04 (0.00;0.16), respectively. Four patients have survived > 3 years; two remain alive at 46 and 96 months and two have died at 43 and 53 months, both with CNS disease outside of the treatment field and one with extra-CNS metastases. Conclusions: 124I-omburtamab via CED into the brain stem of children with DIPG and previously irradiated provides a possibility for improved treatment of DIPG. A dose of 8mCi and an infusion volume of 8,000 µl is considered safe and may provide a distribution volume large enough to cover tumor volumes up to 20 cm3. The median overall survival of all patients included in the trial appears to be increased with 3-4 months compared to historical control data from consortia trials. A phase 2 trial aiming at investigating the efficacy of radiolabeled omburtamab administered via CED is being planned. Clinical trial information: NCT01502917.

The Role of Bak1 Methylation in the Induction of Chromosomal Aberrations under Chronic Low-Intensity External Radiation

Purpose: To study the relationship between the methylation status of the Bаk1 promoter and the frequency of chromosomal aberrations in human blood lymphocytes under chronic low-intensity external ionizing radiation. Material and methods: The study was performed on 41 people (31 men and 10 women, aged from 36 to 83 years) who are former or current employees of the Siberian Group of Chemical Enterprises, who have been exposed or haven't been exposed to chronic low-intensity external radiation in the course of their professional activities. The workers included in the study were divided into two groups: the first – 15 people who did not have exposure, the second – 26 people who had external exposure (gamma radiation, total dose 89–716 mSv). Whole blood was used to isolate DNA and evaluate chromosomal aberrations in lymphocytes. The methylation status of the Bаk1 promoter was determined using methylsensitive PCR, which was performed after pretreatment of the isolated DNA with methylsensitive AoxI restrictase. The obtained quantitative data were analyzed using the Statistica 10. The differences were considered statistically significant at p ≤ 0.05. Results: The methylation status of the Bаk1 promoter in the study groups does not differ (p = 0.18). The study of the effect of external radiation dose on the methylation status of the Bak1 promoter showed that the unmethylated promoter prevails in workers with an average radiation dose of 273.37 ± 43.82 mSv, while the methylated promoter – in workers with an average radiation dose of 183.63 ± 20.58 mSv (p = 0.03). The unmethylated promoter Bаk1 is associated with an increased frequency of chromatid fragments in the blood lymphocytes of group 2 workers (p = 0.03). Conclusion: The status of methylation of the Bаk1 promoter in human blood lymphocytes under chronic low-intensity ionizing radiation does not change, but it is observed to depend on the radiation dose and is associated with an increased frequency of chromosomal aberrations (chromatid fragments). Thus, the unmethylated Bаk1 promoter prevails when the external radiation dose is increased. An increase in the frequency of chromatid fragments is associated with an unmethylated Bаk1 promoter. In addition, exposure to chronic low-intensity external radiation is accompanied by a decrease in the frequency of chromosomal fragments in the blood lymphocytes of workers of the Siberian Group of Chemical Enterprises.