Radiotherapy Techniques Research Articles

The current role of adjuvant radiotherapy in management of medullary thyroid carcinoma: A single institute analysis.

Medullary thyroid carcinoma (MTC) accounts for only about 5% of total thyroid cancers. It usually presents as an advanced disease carrying a poor prognosis than well-differentiated thyroid cancers. While the treatment of choice is surgery, the role of adjuvant radiotherapy is still unclear. This retrospective study aims to understand the role of adjuvant radiotherapy in MTC and its effect on survival. We did a retrospective two study to estimate the effect of adjuvant external beam radiotherapy (EBRT) on survival outcomes in MTC. A total of 30 patients who were diagnosed with nonmetastatic MTC during the period 2015 to 2020 were included in the study. Fifteen patients underwent only total thyroidectomy with cervical lymph node dissection. Rest 15 patients received adjuvant EBRT following surgery. A median dose of 60 Gy in 30 fractions, 2 Gy per fraction, 5 days per week, was given by conventional radiotherapy technique. Survival outcomes were estimated using Kaplan-Meier method. A univariate analysis using log rank test was performed to estimate the association of various prognostic factors including age, sex, tumor size, nodal involvement, and surgical resection status on survival outcomes. Median age of presentation in our study is 47 years (inter quartile range: 36-55 years). Median follow-up time is 4 years. Male to female ratio is 2:3-70% of patients presented with T3 lesions and 77% with N1b disease. There was no significant difference in overall survival (OS) in patients who received adjuvant RT following surgery in comparison to patients who underwent only surgery (92.9% vs. 71.4% P value = 0.202). Similarly, there was no improvement in locoregional recurrence-free survival (LRFS) (100% vs. 85.7%, P value-0.157), Distant metastasis-free survival (DMFS) (64.3% vs. 71.4%, P value = 0.725), and Disease-free survival (DFS) (64.3% vs. 64.3%, P value = 0.91). Age, gender, nodal involvement, and surgical resection status (R0, R1, R2) did not have any effect on survival outcomes. DFS (100% vs. 63.6% P value = 0.008), LRFS (100% vs. 94.7% P value = 0.002), and DMFS (100% vs. 63.2% P value = 0.006) were significantly better in T2 lesions compared to advanced lesions. Adjuvant EBRT failed to show any significant improvement in survival outcomes and locoregional control in MTC. Further prospective randomized clinical trials are needed to validate the role of EBRT in MTC. Clinicians should proceed with caution before advising adjuvant radiotherapy in MTC and make an informed decision after weighing the pros and cons of giving adjuvant EBRT.

Electrochemical cell for synchrotron nuclear resonance techniques.

Developing new materials for Li-ion and Na-ion batteries is a high priority in materials science. Such development always includes performance tests and scientific research. Synchrotron radiation techniques provide unique abilities to study batteries. Electrochemical cell design should be optimized for synchrotron studies without losing electrochemical performance. Such design should also be compatible with operando measurement, which is the most appropriate approach to study batteries and provides the most reliable results. The more experimental setups a cell can be adjusted for, the easier and faster the experiments are to carry out and the more reliable the results will be. This requires optimization of window materials and sizes, cell topology, pressure distribution on electrodes etc. to reach a higher efficiency of measurement without losing stability and reproducibility in electrochemical cycling. Here, we present a cell design optimized for nuclear resonance techniques, tested using nuclear forward scattering, synchrotron Mössbauer source and nuclear inelastic scattering.

Demonstration of an integrated-heating load frame for quantitatively assessing microscale tensile properties of copper and Zircaloy-2

Small-scale mechanical testing (SSMT) is of great interest in the nuclear materials community as it permits the use of surrogate irradiation techniques, such as ion beam irradiation when investigating the impact of irradiation damage on mechanical properties. The design of a micro-electro-mechanical-system (MEMS) micro-tensile stage is demonstrated to enable micron-sized specimen testing up to failure under ambient and reactor-relevant temperatures. Copper and Zircaloy-2 microscale specimens, having gauge lengths of 200 μm, gauge widths of 48 μm, and specimen-dependent constant gauge thicknesses of 10 μm to 26 μm, are fabricated using micro-wire electrical discharge machining and focused ion beam milling. From each gauge section, microstructure data is captured prior to testing using electron backscatter diffraction analysis, and an optimized digital image correlation speckle pattern is deposited on the specimen surface. The speckle pattern is tracked during deformation and post-processed to obtain strain-field evolution maps throughout deformation. Strain maps provide a means to account for and explain microstructure-dependent features observed in the captured stress-strain curves. The combination of using micro-wire electrical discharge machining, focused ion beam cleaning, and ion beam induced platinum deposition for micron-sized specimen preparation as well as utilizing microfabrication techniques to fabricate an integrated heating microtensile load frame reported herein serve as a demonstration of SSMT approaches that can be adopted to tackle challenging problems in nuclear materials research, including but not limited to the effects of ion beam irradiation on mechanical performance and providing experimental data to support small-scale modeling efforts of embrittling precipitates or radiation-induced segregation.

Potential for boron neutron capture therapy (BNCT) with ASCT2-targeted boron agents.

233 Background: Boron Neutron Capture Therapy (BNCT) is a cutting-edge particle irradiation technique that utilizes the nuclear reaction triggered by the irradiation of non-radioactive boron-10 with thermal neutrons, selectively annihilating tumor cells that have incorporated boron. In the clinical arena, Boronophenylalanine (BPA), a phenylalanine compound targeting amino acid receptors, has been the cornerstone of BNCT. While BNCT has been effective against malignant gliomas, its dependency on BPA uptake has illuminated the existence of inherent resistance within specific cells, tissues, and cancer types. This study pivots towards the Alanine-serine-cysteine transporter 2 (ASCT2)—a transporter distinct from LAT1—investigating its potential as a gateway for the development of innovative boron carriers, with the aim of expanding the clinical applicability and effectiveness of BNCT. Methods: This research embarked on in vitro investigations to evaluate boron accumulation in F98 and C6 rat glioma cells, and 9L rat gliosarcoma, following 24 hours of exposure to BPA and GluB-2 (10 μg B/ml each). Complementary in vivo studies involved the intravenous administration of these compounds to an F98 rat brain tumor model, with the subsequent measurement of boron distribution at 2.5, 6, and 24 hours post-administration. The efficacy of these treatments was then ascertained through neutron irradiation experiments, gauging therapeutic outcomes via the survival periods of the subjects. Results: In vitro findings highlighted that GluB-2 facilitated a significantly higher intracellular boron concentration compared to BPA in F98 cells (p=0.02, Student's t-test). In vivo results indicated that the apex of boron biodistribution in tumors was achieved at 2.5 hours post-BPA treatment and at 6 hours post-GluB-2 treatment, with GluB-2 securing a superior maximum intratumor boron concentration. Survival analysis revealed a mean survival of 28.0±2.5 days for the neutron alone group, 37.7±5.0 days for the group receiving BPA IV + BNCT at 2.5 hours, 55.1±19.9 days for the group treated with GluB-2 IV + BNCT at 6 hours, and 25.3±1.4 days for the untreated group. Remarkably, the group treated with GluB-2 demonstrated significantly prolonged survival compared to the BPA-treated group (p<0.001, log-rank test). Conclusions: Combining BNCT with GluB-2 showed superior efficacy over BPA. Further research is needed to optimize boron concentration timing and ASCT2 expression levels, yet GluB-2 presents a promising advancement in BNCT, potentially transforming malignant brain tumor treatment.

Adaptive radiotherapy (up to 74 Gy) or standard radiotherapy (66 Gy) for patients with stage III non-small-cell lung cancer, according to [18F]FDG-PET tumour residual uptake at 42 Gy (RTEP7–IFCT-1402): a multicentre, randomised, controlled phase 2 trial

Thoracic radiation intensification is debated in patients with stage III non-small-cell lung cancer (NSCLC). We aimed to assess the activity and safety of a boost radiotherapy dose up to 74 Gy in a functional sub-volume given according to on-treatment [18F]fluorodeoxyglucose ([18F]FDG)-PET results. In this multicentre, randomised, controlled non-comparative phase 2 trial, we recruited patients aged 18 years or older with inoperable stage III NSCLC without EGFR mutation or ALK rearrangement with an Eastern Cooperative Oncology Group performance status of 0-1, and who were affiliated with or a beneficiary of a social benefit system, with evaluable tumour or node lesions, preserved lung function, and who were amenable to curative-intent radiochemotherapy. Patients were randomly allocated using a central interactive web-response system in a non-masked method (1:1; minimisation method used [random factor of 0·8]; stratified by radiotherapy technique [intensity-modulated radiotherapy vs three-dimensional conformal radiotherapy] and by centre at which patients were treated) either to the experimental adaptive radiotherapy group A, in which only patients with positive residual metabolism on [18F]FDG-PET at 42 Gy received a boost radiotherapy (up to 74 Gy in 33 fractions), with all other patients receiving standard radiotherapy dosing (66 Gy in 33 fractions over 6·5 weeks), or to the standard radiotherapy group B (66 Gy in 33 fractions) over 6·5 weeks. All patients received two cycles of induction platinum-based chemotherapy cycles (paclitaxel 175 mg/m2 intravenously once every 3 weeks and carboplatin area under the curve [AUC]=6 once every 3 weeks, or cisplatin 80 mg/m2 intravenously once every 3 weeks and vinorelbine 30 mg/m2 intravenously on day 1 and 60 mg/m2 orally [or 30 mg/m2 intravenously] on day 8 once every 3 weeks). Then they concomitantly received radiochemotherapy with platinum-based chemotherapy (three cycles for 8 weeks, with once per week paclitaxel 40 mg/m2 intravenously and carboplatin AUC=2 or cisplatin 80 mg/m2 intravenously and vinorelbine 20 mg/m2 intravenously on day 1 and 40 mg/m2 orally (or 20 mg/m2 intravenously) on day 8 in 21-day cycles). The primary endpoint was the 15-month local control rate in the eligible patients who received at least one dose of concomitant radiochemotherapy. This RTEP7-IFCT-1402 trial is registered with ClinicalTrials.gov (NCT02473133), and is ongoing. From Nov 12, 2015, to July 7, 2021, we randomly assigned 158 patients (47 [30%] women and 111 [70%] men) to either the boosted radiotherapy group A (81 [51%]) or to the standard radiotherapy group B (77 [49%)]. In group A, 80 (99%) patients received induction chemotherapy and 68 (84%) received radiochemotherapy, of whom 48 (71%) with residual uptake on [18F]FDG-PET after 42 Gy received a radiotherapy boost. In group B, all 77 patients received induction chemotherapy and 73 (95%) received radiochemotherapy. At the final analysis, the median follow-up for eligible patients who received radiochemotherapy (n=140) was 45·1 months (95% CI 39·3-48·3). The 15-month local control rate was 77·6% (95% CI 67·6-87·6%) in group A and 71·2% (95% CI 60·8-81·6%) in group B. Acute (within 90 days from radiochemotherapy initiation) grade 3-4 adverse events were observed in 20 (29%) of 68 patients in group A and 33 (45%) of 73 patients in group B, including serious adverse events in five (7%) patients in group A and ten (14%) patients in group B. The most common grade 3-4 adverse events were febrile neutropenia (seven [10%] of 68 in group A vs 16 [22%] of 73 in group B), and anaemia (five [7%] vs nine [12%]). In the acute phase, two deaths (3%) occurred in group B (one due to a septic shock related to chemotherapy, and the other due to haemotypsia not related to study treatment), and no deaths occurred in group A. After 90 days, one additional treatment-unrelated death occurred in group A and two deaths events occurred in group B (one radiation pneumonitis and one pneumonia unrelated to treatment). A thoracic radiotherapy boost, based on interim [18F]FDG-PET, led to a meaningful local control rate with no difference in adverse events between the two groups in organs at risk, in contrast with previous attempts at thoracic radiation intensification, warranting a randomised phase 3 evaluation of such [18F]FDG-PET-guided radiotherapy dose adaptation in patients with stage III NSCLC. Programme Hospitalier de Recherche Clinique National 2014.

Dosimetric and radiobiological advantages from deep inspiration breath-hold and free breath technique for left-sided breast radiation using 3DCRT, IMRT and Rapid Arc methods-a complete assessment.

The verification and use of the best treatment approach using 3D conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and Rapid Arc methods for left breast radiation with dosimetric and radiobiological characteristics. The use of custom-built Python software for the estimation and comparison of volume, mean dose, maximum dose, monitor units and normal tissue integral dose along with radiobiological parameters such as NTCP, tumor control probability, equivalent uniform dose and LKB's effective volume from 3DCRT, IMRT and Rapid Arc planning with deep inspiration with breath holding (DIBH) and free breadth (FB) techniques. Volume growth of three-fourth in DIBH compared with FB causes a decrease in cardiac doses and complications because the left lung expands, pulling the heart away from the chest wall and the treatment area. A tiny area of the left lung was exposed during treatment, which reduced the mean dose. There was little difference in the treatment approaches because the spinal cord was immobile in both techniques. Rapid Arc is the unmatched modality for left-sided breast irradiation with significant patient breath-hold, as shown by the comparison of dosimetric and radiobiological parameters from treatment techniques with a deep inspiration breath-hold approach.

(Invited) Perspectives from in Situ spectroscopy on the Molecular-Level Interactions of Carbon Dioxide in Nanomaterials for Capture and Conversion

Understanding the molecular level foundations of CO2 capture and conversion might unveil design strategies for efficient materials for these key decarbonization technologies. The control over the reaction channel in the complex network of reactions to produce selectively and on-demand chemicals from CO2 via electrocatalysis is appealing to scientists worldwide on a fundamental and technological level. Operando techniques have become very popular to help achieve this goal as demonstrated by a flourishing number of dedicated studies [1-3] and other initiatives for discussion [4-6]. In this contribution, I will present recent work on the spectroscopic characterisation of the CO2 interaction with several prototypical nanostructural systems of relevance, [7-11] emphasising characteristic spectroscopic fingerprints and their critical assessment. This contribution aims to discuss opportunities and current limitations encountered in situ X-ray methods to extract mechanistic insights.[1] Y. Han, H. Zhang, Y. Yu, Z. Liu, In Situ Characterization of Catalysis and Electrocatalysis Using APXPS, ACS Catalysis, 11 (2021), 1464-1484.[2] V. Pfeifer, M. Hävecker, J. J. Velasco Vélez, A. Knop-Gericke, R. Schlögl, R. Arrigo, An in situ electrochemical cell for studying OER materials, Topics in Catalysis, 61 (2019), 2064-2084.[3] G. Held, F. Venturini, D. C. Grinter, P. Ferrer, R. Arrigo, L. Deacon, W. Quevedo Garzon, K. Roy, A. Large, C. Stephens, A. Watts, P. Larkin, M. Hand, H. Wang, L. Pratt, J. J. Mudd, T. Richardson, S. Patel, M. Hillman and S. Scott, Ambient-pressure end station of the Versatile Soft X-ray (VerSoX) beamline at Diamond Light Source, J. Synchrotron Rad., 27 (2020), 1153-1166.[4] R. Arrigo, A. Logsdail, L. Torrente-Murciano, Highlights from Faraday Discussion on Designing Nanoparticle Systems for Catalysis, London, UK, May 2018, (Conference Report) Chem. Commun., 2018, 54, 9385-9393DOI: 10.1039/C8CC90324G;[5] R. Arrigo et al., The challenges of characterising nanoparticulate catalysts: general discussion Faraday Discussion, 208 (2018), 339-394.[6] C. R. A. Catlow, P. wells, D. Gianolio Synchrotron radiation techniques in catalytic science, Phys. Chem. Chem. Phys., 22 (2020), 18745-18746.[7] R. Arrigo, R. Blume, V. Streibel, C. Genovese, A. Roldan, M. E. Schuster, C. Ampelli, S. Perathoner, J.-J. Velasco-Vélez, M. Hävecker, A. Knop-Gericke, R. Schlögl, G. Centi, Dynamics at Polarized, Carbon Dioxide/Iron Oxyhydroxide Interfaces Unveil the Origin of Multicarbon Product Formation, ACS Catalysis, 12 (2021) 411-430.[8] J.-J. Velasco-Vélez, T. Jones, D. Gao, E. Carbonio, R. Arrigo, C.-J. Hsu, Y.-C. Huang, C.-L. Dong, J.-M. Chen, J.-F. Lee, P. Strasser, B. Roldan Cuenya, R. Schlögl, A. Knop-Gericke, C.-H. Chuang, The Role ofthe Copper Oxidation State in the Electrocatalytic Reduction of CO2 into Valuable Hydrocarbons, ACS Sustainable Chem. Eng., 7 (2019), 1485–1492.[9] J.-J. Velasco-Vélez, C.-H. Chuang, D. Gao, Q. Zhu, D. Ivanov, H. S. Jeon, R. Arrigo, R. V. Mom, E. Stotz, H.-L. Wu, T. E. Jones, B. Roldan Cuenya, A. Knop-Gericke, R. Schlögl, On the activity/selectivity and phase stability of thermally grown copper oxides during the electrocatalytic reduction of CO2, ACS Catalysis, 10 (2020) 11510-11518.[10] J-J. Velasco-Velez, R.V. Mom, L.-E. Sandoval-Diaz, L. J. Falling, C.-H. Chuang, D. Gao, T. E. Jones, Q. Zhu, R. Arrigo, B. Roldan Cuenya, A. Knop-Gericke, T. Lunkenbein, R. Schlögl, Revealing the ActivePhase of Copper during the Electroreduction of CO2 in Aqueous Electrolyte by Correlating In Situ X-ray Spectroscopy and In Situ Electron Microscopy, ACS Energy Lett., 5 (2020), 2106–2111.[11] R. Arrigo, R. Blume, A. Large, J.-J. Velesco-Velez, M., Haevecker, A. Knop-Gericke, G. Held, Dynamics over a Cu-graphite electrode during the gas-phase CO2 reduction investigated by APXPS, Faraday Discuss., 236 (2022) 126-140.

Incorporating intensity modulated total body irradiation into a Children's Oncology Group trial: Rationale, techniques, and safeguards.

Historically, total body irradiation (TBI) has been delivered using static, parallel opposed photon beams (2D-TBI). Recently, centers have increasingly used intensity-modulated radiation therapy (IMRT) techniques for TBI. Relative to 2D-TBI, IMRT can reduce doses to critical organs (i.e., lungs and kidneys) while delivering myeloablative doses to the rest of the body, so it may decrease the risk of toxicity while maintaining oncologic outcomes. Despite these potential benefits, delivering TBI using IMRT introduces new challenges in treatment planning and delivery. We describe the extensive experience with IMRT-based TBI at Stanford University and City of Hope Cancer Center. These groups, and others, have reported favorable clinical outcomes and have developed methods to optimize treatment planning and delivery. A critical next step is to evaluate the broader adoption of this approach. Therefore, IMRT-based TBI will be incorporated into a prospective, multi-institutional Children's Oncology Group study with careful procedures and safeguards in place.

Anion exchange membrane with enhanced alkaline stability through radiation grafting of ETFE for solid polymer electrolytes

AbstractSolid polymer electrolyte membranes are considered as the nub of many electrochemical devices. Given the climate crisis and related concerns, the evolution of new membrane materials to support the sustainable systems is inevitable. Building on recent advances with the radiation technique and polymer chemistry, herein, anion exchange membranes (AEMs), ETFE‐g‐1VIm/4VP, were fabricated through graft copolymerization of vinyl heterocyclic monomer binary mixture, such as 1‐vinylimidazole (1‐VIm) and 4‐vinylpyridine (4‐VP) onto ethylene tetrafluoroethylene (ETFE), a main polymer backbone without aryl ether bonds. The grafting reaction was achieved at 60°C and then followed by quaternization as a subsequent step. The effects of various reaction grafting conditions were investigated. The ETFE‐g‐1VIm/4VP AEM were characterized w.r.t the morphological and structural features. The dense surface of the grafted membranes is proved by field emission‐scanning electron microscopy (FE‐SEM) images, which also show that the vinyl entities are clearly distributed in the prepolymer, which may lead to a continuous ion transport channel. AEMs processed from the highest graft yield showed good hydroxide conductivity at 90°C, reaching 16.9 mS/cm due to the presence of more transport sites. The same membrane has a relatively good alkaline stability, which is studied through weight percentage method and FT‐IR. Hence, we assume that the introduction of multi‐cationic moieties, pyridinium and imidazolium, contributes to the performance of anion exchange membranes and makes a perfect balance, especially the hydrophilicity and hydrophobicity. These data highlight the potential of the copolymer as an anion exchange membrane for wide spectra of electrochemical applications.Highlights AEMs based on ETFE‐g‐1VIm/4VP are developed via radiation grafting. The membrane exhibits remarkable alkaline stability. FT‐IR, SEM, and weight percentage methods were used to prove the alkaline stability. The membrane has the potential to be used for different electrochemical applications.

Effects of brain radiotherapy strategies on survival in the era of MRI for patients with limited stage small cell lung cancer

Background and purposeIn the context of the widespread availability of magnetic resonance imaging (MRI) and aggressive salvage irradiation techniques, there has been controversy surrounding the use of prophylactic cranial irradiation (PCI) for small-cell lung cancer (SCLC) patients. This study aimed to explore whether regular brain MRI plus salvage brain irradiation (SBI) is not inferior to PCI in patients with limited-stage SCLC (LS-SCLC).MethodsThis real-world multicenter study, which was conducted between January 2014 and September 2020 at three general hospitals, involved patients with LS-SCLC who had a good response to initial chemoradiotherapy and no brain metastasis confirmed by MRI. Overall survival (OS) was compared between patients who did not receive PCI for various reasons but chose regular MRI surveillance and followed salvage brain irradiation (SBI) when brain metastasis was detected and patients who received PCI.Results120 patients met the inclusion criteria. 55 patients received regular brain MRI plus SBI (SBI group) and 65 patients received PCI (PCI group). There was no statistically significant difference in median OS between the two groups (27.14 versus 33.00 months; P = 0.18). In the SBI group, 32 patients underwent whole brain radiotherapy and 23 patients underwent whole brain radiotherapy + simultaneous integrated boost. On multivariate analysis, only extracranial metastasis was independently associated with poor OS in the SBI group.ConclusionThe results of this real-world study showed that MRI surveillance plus SBI is not inferior to PCI in OS for LS-SCLC patients who had a good response to initial chemoradiotherapy.

Dosimetric Analyses of the Three Radiation Techniques Used in the EORTC 22922/10925 IM-MS Breast Cancer Trial

PurposeThe aim of the current study is to compare the dosimetry of 3 radiation therapy (RT) techniques used in the EORTC 22922/10925 trial for irradiating the internal mammary (IM) and medial supraclavicular nodes (MS) using a treatment planning system available nowadays for dose calculation. MethodsWe performed a retrospective dosimetry analysis of anonymised data; thus, ethics approval was not required. Ten cases of left-sided breast were randomly selected for RT planning to a total dose of 50 Gy in 25 fractions. The treatment planning was done according to the trial's protocol and under the supervision of the EORTC trial's coordinators. Doses to planning target volumes (PTV) and to organs at risk (OARs) are reported. Data is presented in descriptive statistics. ResultsA total of 10 cases and 40 treatment plans (4 plans per case: standard-plan A, modified standard-plan B, individualised-plan C and breast-only–plan D). For all planning techniques, the mean dose to the PTV of the left breast (plan A-D) and the PTV-MS (plan A-C) exceeded 95% of the prescribed dose (>47.5 Gy). The individualised technique (plan C) had a lower coverage for PTV-IM, with a mean of 87% of the prescribed dose compared to ∼102% for plans A and B. The dose to OARs varied between techniques, with the mean heart dose being higher in the standard and modified standard techniques (18.3 and 16.6 Gy, respectively) compared to the individualised technique (9.5 Gy). ConclusionsThe 3 RT techniques used in the trial varied in target coverage and OARs dose. Our results may help to understand the observed larger absolute benefit of individualised IM-MS treatment planning in terms of breast cancer outcomes.

Adjuvant external beam radiotherapy combined with brachytherapy for intermediate-risk cervical cancer

ObjectivePatients with intermediate-risk cervical cancer receive external beam radiotherapy (EBRT) as adjuvant treatment. It is commonly administered with brachytherapy without proven benefits. Therefore, we evaluated the frequency of brachytherapy use,...

A Multicentric study on a dosimetric comparison of extended SSD technique, VMAT-Based and helical tomotherapy (HT) for total body irradiation (TBI)

PurposeIn study, it was aimed to evaluate the dose volume histograms (DVH) of extended SSD technique, VMAT-based, and helical tomotherapy plans dosimetrically in a multi-institutional context to achieve higher plan quality and to harmonize total body irradiation plans. MethodsFour different clinical centers participated in the study. The CT images of ten patients were used in this study. During the first phase, ten patients enrolled for TBI were planned by multiple centers according to a common protocol. During the second phase, all centers shared their plans’ DVHs. Treatment plans were evaluated according to the critical organ dose limits. Statistical analysis was performed in the SPSS (version 22.0) program (p < 0.05). ResultsIn study, the results indicated that there was a statistically significant and considerable difference in the dose coverage of PTV, beam delivery time and MU, lens doses, and kidney doses between the four techniques (p < 0.001). The mean lung doses of the four centers were below 10 Gy. No significant difference in maximum liver doses between plans was obtained. ConclusionIn conclusion, although four treatment techniques were suitable for TBI treatment, more homogeneous dose distribution, and lower critical organ doses were obtained with the tomotherapy technique. However, treatment time, MU, and dose rate for lung were disadvantages of the tomotherapy technique. When it comes to deciding on the TBI treatment method, it need to be reviewed some important points. It is needed to sufficient data on long-term results to be able to standardize TBI techniques between centers.

A comprehensive overview of radiation therapy impacts of various cancer treatments and pivotal role in the immune system.

The cancer treatment landscape is significantly evolving, focusing on advanced radiation therapy methods to maximize effectiveness and minimize the adverse effects. Recognized as a pivotal component in cancer and disease treatment, radiation therapy (RT) has drawn attention in recent research that delves into its intricate interplay with inflammation and the immune response. This exploration unveils the underlying processes that significantly influence treatment outcomes. In this context, the potential advantages of combining bronchoscopy with RT across diverse clinical scenarios, alongside the targeted impact of brachytherapy, are explored. Concurrently, radiation treatments serve multifaceted roles such as DNA repair, cell elimination, and generating immune stress signaling molecules known as damage-associated molecular patterns, elucidating their effectiveness in treating various diseases. External beam RT introduces versatility by utilizing particles such as photons, electrons, protons, or carbon ions, each offering distinct advantages. Advanced RT techniques contribute to the evolving landscape, with emerging technologies like FLASH, spatially fractionated RT, and others poised to revolutionize the field. The comprehension of RT, striving for improved treatment outcomes, reduced side effects, and facilitating personalized and innovative treatments for cancer and noncancer patients. After navigating these advancements, the goal is fixed to usher in a new era in which RT is a cornerstone of precision and effectiveness in medical interventions. In summarizing the myriad findings, the review underscores the significance of understanding the differential impacts of radiation approaches on inflammation and immune modulation, offering valuable insights for developing innovative therapeutic interventions that harness the immune system in conjunction with RT.

Prostate radiotherapy may cause fertility issues: a retrospective analysis of testicular dose following modern radiotherapy techniques

BackgroundProstate cancer in younger men is rare but not exceptional. Radiotherapy is a cornerstone of prostate cancer treatment and yet, its impact on fertility is scarcely reported in literature. Given the radiosensitivity of testicular tissue, this study aimed to determine the testicular dose using modern radiotherapy techniques for definitive prostate irradiation.MethodsOne hundred radiotherapy plans were reviewed. Testicles were contoured retrospectively without dosimetric optimization on testicles.ResultsThe median testicular dose was 0.58 Gy: 0.18 Gy in stereotactic plans, 0.62 Gy in Volumetric Modulated Arc Therapy plans and 1.50 Gy in Tomotherapy plans (p < 0.001). Pelvic nodal irradiation increased the median testicular dose to 1.18 Gy versus 0.26 Gy without nodal irradiation (p < 0.001). Weight and BMI were inversely associated with testicular dose (p < 0.005). 65% of patients reached the theoretical dose threshold for transient azoospermia, and 10% received more than 2 Gy, likely causing definitive azoospermia.ConclusionDespite being probably lower than doses from older techniques, the testicular dose delivered with modern prostate radiotherapy is not negligible and is often underestimated because the contribution of daily repositioning imaging is not taken into account and most Treatment Planning Systems underestimate the out of field dose. Radiation oncologists should consider the impact on fertility and gonadal endocrine function, counseling men on sperm preservation if they wish to maintain fertility.Trial registration: retrospectively registered.

A Four-dimensional Computed Tomography Generated Internal Target Volume Approach to Paediatric High Risk Neuroblastoma to Reduce Organ at Risk and Normal Tissue Irradiation

AimsThe magnitude of upper abdominal organ motion in children may be overestimated by current planning target volumes (PTV). A four-dimensional computed tomography (4DCT) – derived internal target volume (ITV) is frequently used in adult radiotherapy to take respiratory-related organ motion into account. In this study, the dosimetric consequences for target coverage and organs at risk from the use of an ITV approach compared to standard PTV margins in children with high-risk neuroblastoma were investigated. Materials and methods14 patients, median age 4.1 years, range 1.5 – 18.9 years, (9 midline targets, 5 lateralised) each had two dual arc volumetric modulated arc therapy (VMAT) plans (14 ×1.5 Gy) generated. One used an ITV-approach; motion information derived from 4DCT (PTV_itv) with a 5mm ITV to PTV expansion, and the other a PTV margin of 10mm from CTV to PTV (PTV_standard). Differences in absolute PTV volume and organ at risk doses are described. ResultsThe ITV approach resulted in a highly significant reduction in PTV size of 38% (p<0.0001). For midline targets, an ITV approach resulted in a small but statistically significant reduction in combined mean kidney dose of 0.8Gy, p 0.01. Mean heart and lung dose were reduced by an average of 1 Gy with an ITV approach. Non-PTV integral dose from 30.4 Gy L to 27.8 Gy L using an ITV approach. ConclusionAn ITV-approach to respiratory related organ motion management in children can significantly reduce absolute PTV volumes, maintain target coverage and reduce dose delivered to normal tissue in proximity to the target. This is an essential step to maximising the benefits of highly conformal radiotherapy techniques including VMAT for this patient group, and in the future with Proton Therapy.

Peer Review in Radiation Oncology: Where Does the Middle East, North Africa, and Türkiye Region Stand?

This study aims to assess the status of radiation oncology peer review procedures across the Middle East, North Africa, and Türkiye (MENAT) region. A cross-sectional electronic survey was conducted among radiotherapy centers in the MENAT region in March 2024. It assessed peer review practices, departmental demographics, perceived importance of peer review, and potential barriers. Data from 177 radiation oncology centers revealed varying peer review implementation across the MENAT region. Egypt had the highest participation (16.4%) among all responders. Most centers (31%) treated 500-1,000 cases annually. The majority (77.4%) implemented peer review, with varying levels between countries and across different centers. Advanced radiotherapy techniques significantly correlated with implementation of peer review (P < .05). Peer review meetings were mostly scheduled on a weekly basis (46%) and organized by radiation oncologists (84.7%). Target volume contouring (89%) and radiotherapy prescription (82%) were frequently peer-reviewed. Respondents with peer review at their institutions significantly valued peer review for education, adherence to guidelines, improving planning protocols, and reducing variation in practice institutions without peer review (P < .05). The most frequently reported barriers to peer review were having a high number of patients (56%) and shortage of time (54%). Peer review is essential for improving the quality of practice in radiation oncology. Despite some discrepancies, numerous obstacles, and challenges in implementation, it is instrumental in the improvement of patient care in most centers throughout the region. Raising awareness among radiation oncologists about the importance of peer review is paramount to lead to better outcomes.

CEREBRAL RADIONECROSIS IN PATIENTS IRRADIATED FOR CAVUM CANCER: RETROSPECTIVE STUDY OF 15 CASES

Introduction: Cerebral radionecrosis is a rare but a serious complication induced by radiotherapy of the nasopharyngeal cancer. Since nasopharyngeal cancer is common to have skull base infiltration, radiation fields cover inevitably the temporal lobes despite the use of the more advanced intensity-modulated radiotherapy (IMRT). Even though the development of imaging means and the systematic practice of CT and MRI in post-therapeutic monitoring, the diagnosis and treatment of cerebral remain challenging. Materiel and Method:A retrospective study including fifteen cases of cerebral radionecrosis occurring after radiotherapy of cavum cancer, based on data from 382 irradiated for cavum cancer during the period from January 2017 to January 2022 and who were regularly followed in post-therapeutic monitoring. Results: The incidence of cerebral radionecrosis in our patients was 3,9%. The average age of patients was 47.5 years (range 28 - 62 years), with a female predominance (sex ratio: 4M/11F = 0.36). All our patients were followed for locally advanced UCNT of the cavum (73% stage IVA and 27 % stage III). 80% of cases have benefited from conformal radiotherapy technique by intensity modulation (VMAT archtherapy). And all cases have had concomitant chemotherapy. Cerebral radionecrosis occurred after an average delay of 31.6 months (11-77 months) from the end of irradiation. The location of the cerebral radionecrosis lesions was temporal in all our patients. Exploring dosimetric data of our patients, we noted that in 58% of cases the dose constraint at the level of the temporal lobe affected by radionecrosis was not respected. Cerebral radionecrosis was initially discovered on MRI of the cavum, a brain MRI was subsequently requested to show areas of cerebral radionecrosis. Spectroscopy was carried out in 33% of patients. Cerebral radionecrosis was treated with corticosteroid therapy in 53% of cases. After a mean follow-up of 19.8 months (2-63 months) the evolution of cerebral radionecrosis in patients irradiated fornasopharyngeal cancer, was marked by radiological stability without the appearance of clinical symptoms in 53% of cases. Conclusion: Cerebral radionecrosis of radiation-treated cavum patients could be a devastating complication. Furthermore, the differential diagnosis remains challenging and may require the use of advanced imaging modalities. The intricate relationship between dose parameters and radionecrosis incidence requires large-scale longitudinal studies. Despite the fact that there is no definitive treatment for cerebral radionecrosis, bevacizumab has proven to be an encouraging treatment option.

Potential Use of Irradiation Techniques in Life Cycle Assessment of Polyethylene Terephthalate (PET) Plastic Waste

Plastic waste generation makes the second largest contribution of 18.6% to the total generation of municipal solid waste. Plastic waste often becomes a problem in the environment because it does not decompose easily. Polyethylene terephthalate (PET) is one type of plastic waste. This paper aims to provide a general review of the potential for using nuclear energy in the form of irradiation techniques in assessing the life cycle of PET plastic waste. The research method used is a literature study based on several related studies. The life cycle assessment method can be used to analyze potential uses and their impacts. Life cycle assessment consists of the stages of determining objectives and scope, life cycle inventory analysis, life cycle impact assessment, and interpretation. A SWOT analysis of the PET sorting program from generation sources is needed as a complement to the life cycle assessment analysis. The potential for PET irradiation techniques is in two ways, namely direct and indirect. The first way, is PET plastic waste is exposed to a certain dose of radiation directly to degrade the material properties of PET plastic waste. The second way, PET plastic waste is substituted into other products, and then a certain dose of radiation is given. At the stage of determining life cycle goals, for example, measuring the impact of irradiation techniques on the reuse or recycling of PET plastic waste. The scope is limited to “gate to gate”, from receiving PET plastic to PET irradiation. The functional unit as a basic unit can be used based on 1 kg of PET plastic. The use of nuclear power through irradiation techniques has the potential to be used in processing PET plastic. Keywords: irradiation, polyethylene terephthalate (PET), life cycle assessment

Enhanced 3D dose prediction for hypofractionated SRS (gamma knife radiosurgery) in brain tumor using cascaded-deep-supervised convolutional neural network.

Gamma Knife radiosurgery (GKRS) is a well-established technique in radiation therapy (RT) for treating small-size brain tumors. It administers highly concentrated doses during each treatment fraction, with even minor dose errors posing a significant risk of causing severe damage to healthy tissues. It underscores the critical need for precise and meticulous precision in GKRS. However, the planning process for GKRS is complex and time-consuming, heavily reliant on the expertise of medical physicists. Incorporating deep learning approaches for GKRS dose prediction can reduce this dependency, improve planning efficiency and homogeneity, streamline clinical workflows, and reduce patient lagging times. Despite this, precise Gamma Knife plan dose distribution prediction using existing models remains a significant challenge. The complexity stems from the intricate nature of dose distributions, subtle contrasts in CT scans, and the interdependence of dosimetric metrics. To overcome these challenges, we have developed a "Cascaded-Deep-Supervised" Convolutional Neural Network (CDS-CNN) that employs a hybrid-weighted optimization scheme. Our innovative method incorporates multi-level deep supervision and a strategic sequential multi-network training approach. It enables the extraction of intra-slice and inter-slice features, leading to more realistic dose predictions with additional contextual information. CDS-CNN was trained and evaluated using data from 105 brain cancer patients who underwent GKRS treatment, with 85 cases used for training and 20 for testing. Quantitative assessments and statistical analyses demonstrated high consistency between the predicted dose distributions and the reference doses from the treatment planning system (TPS). The 3D overall gamma passing rates (GPRs) reached 97.15% ± 1.36% (3mm/3%, 10% threshold), surpassing the previous best performance by 2.53% using the 3D Dense U-Net model. When evaluated against more stringent criteria (2mm/3%, 10% threshold, and 1mm/3%, 10% threshold), the overall GPRs still achieved 96.53% ± 1.08% and 95.03% ± 1.18%. Furthermore, the average target coverage (TC) was 98.33% ± 1.16%, dose selectivity (DS) was 0.57 ± 0.10, gradient index (GI) was 2.69 ± 0.30, and homogeneity index (HI) was 1.79 ± 0.09. Compared to the 3D Dense U-Net, CDS-CNN predictions demonstrated a 3.5% improvement in TC, and CDS-CNN's dose prediction yielded better outcomes than the 3D Dense U-Net across all evaluation criteria. The experimental results demonstrated that the proposed CDS-CNN model outperformed other models in predicting GKRS dose distributions, with predictions closely matching the TPS doses.