Strahlentherapie und Onkologie最新文献

Background: Cardiac tumors are exceedingly rare with metastatic involvement representing the most frequent form of malignancy within the heart. In patients presenting with inoperable primary or recurrent malignant cardiac sarcomas or cardiac/epicardial/pericardial metastases, stereotactic body radiotherapy (SBRT) serves as an alternative local treatment to surgery or may, in some cases, constitute the sole viable local treatment modality. To date, there are only case reports or small retrospective studies assessing SBRT dose and toxicity for cardiac SBRT. The goal of this prospective multicentric observational study is to systematically evaluate the feasibility, toxicity and outcome of magnetic resonance-guided stereotactic body radiation therapy (MRgSBRT) in the management of primary and secondary cardiac malignancies.

Methods: The treatment is performed using MR-guided SBRT in five fractions on non-consecutive days (6-8 Gy per fraction prescribed to the 80% isodose). Four study centers participate in this prospective phase II trial (Heidelberg, Munich, Rome, Zurich). Eligible patients who consent to participate in the study will undergo treatment as indicated and approved by an interdisciplinary tumor board. Primary objective is to assess the feasibility and safety of online adaptive MRgSBRT; secondary endpoints are local control and survival outcome, acute and late toxicity, patient-reported outcome as well as technical feasibility of treatment.

Discussion: The findings from this study may serve as a foundation for the future integration of cardiac SBRT into clinical practice guidelines for the management of cardiac malignancies.

Melanoma presents significant challenges to treatment due to its complex tumor microenvironment (TME) and the development of various resistance mechanisms in cancer cells. Radiotherapy is one of the main treatment modalities for melanoma. It acts by generating reactive oxygen species (ROS) and inducing DNA damage in melanoma cancer cells. However, these malignant cells develop DNA damage responses (DDRs) to resist ionizing radiation (IR). In addition, tumor cells engage in constant dialogue with surrounding stromal cells, immune cells, and extracellular matrix (ECM) components. These interactions shape tumor progression, metastasis, and resistance to different antitumor agents, including radiotherapy. Key players in this cellular orchestra include stromal cells, macrophages, myeloid cells, and different subsets of T cells. In addition, a unique vascular system and subsequent hypoxia in some regions of the tumor can further stimulate resistance to radiotherapy. Emerging research highlights the role of immune checkpoints, hypoxia, growth factors, and growth factor receptors in modulating tumor responses to radiation. Recent studies have uncovered promising molecular targets such as DNA repair inhibitors, immune checkpoint inhibitors (ICIs), tyrosine kinase inhibitors (TKIs), and hypoxia modulators to sensitize melanoma to radiotherapy. This review aims to synthesize current knowledge on melanoma tumor interactions, providing a comprehensive overview of promising targets for improving radiotherapy outcomes in melanoma patients.

Background and purpose: Radiation oncology (RO) is a key component of cancer care and should be adequately represented in undergraduate medical education. In light of medical training reforms in German medical education and rising expectations for competency-based, practice-oriented learning, this nationwide survey explored medical students' perspectives on RO teaching and its future development.

Materials and methods: A cross-sectional online survey was conducted from 2023 to 2025 across all 38 German medical faculties. Developed by the Working Group on Teaching of the German Society for Radiation Oncology (DEGRO), the 49-item questionnaire addressed curriculum structure, teaching quality, preferred formats, and interest in RO.

Results: Among 1112 participants, 739 completed the survey. Although 96% viewed RO as being essential to cancer care, 62% felt it was underrepresented in the curriculum. Students called for more interdisciplinary and patient-centered teaching and showed high interest in digital and hybrid learning formats. Notably, 60.5% favored interdisciplinary oncology formats including RO, and nearly half expressed interest in elective RO courses.

Conclusion: Despite its recognized importance, RO remains inconsistently represented in medical education. Embedding RO in interdisciplinary oncology modules and expanding digital, longitudinal, and flexible teaching formats could enhance its visibility and relevance. Given students' strong interest in more in-depth exposure, optional and elective formats should be further developed to meet modern educational expectations.

Purpose: This study developed an efficient methodology for in-house 3D-printed vaginal cylinders for gynecologic tumor treatment by evaluating their radiation attenuation, geometric accuracy, and efficacy. Ultimately, we aim to establish a simple, cost-effective approach that facilitates broad clinical adoption.

Methods: Patient-specific vaginal cylinders were designed based on anatomical contours from the treatment planning system (TPS) using CAD software. The process was optimized to minimize manpower and time costs. Radiation attenuation of the 3D printer material was compared with that of water using the Monte Carlo method. Geometric accuracy was automatically analyzed via an in-house MATLAB program. Efficacy was assessed in cases of postoperative vaginal stump recurrence and vaginal cancer with paravaginal invasion.

Results: The tumor shape, delineated by TPS, was imported into CAD software, and the catheter pathway model, designed via subtraction processing, was placed at the optimal position and angle. The design process took approximately 15 min, and the entire workflow was completed within a week, demonstrating its practicality for clinical use. The radiation attenuation error was < 3% compared with water, and the geometric accuracy error was < 0.2 mm. The patient-specific vaginal cylinder provided a favorable dose distribution and was effective in complex cases.

Conclusion: A feasible workflow was established, allowing in-house design and manufacturing with reduced manpower and time costs. With no material or processing issues, this approach is safe, practical, and promising for widespread adoption in personalized brachytherapy.

Purpose: The precise mechanisms underlying radiation-induced cataractogenesis remain incompletely understood. Increased oxidative stress is known to play a central role in cataract pathogenesis. The vitreous humor contributes to maintaining the hypoxic environment of the lens by regulating oxygen pressure and containing antioxidants. This study aims to explore the effect of radiation-induced changes in the vitreous humor on lens health, with a particular focus on its cataractogenic potential.

Methods: In this experimental study, 12 New Zealand rabbits were utilized. A single 20-Gy dose of radiation was administered to the left eye's vitreous humor with a lens-sparing technique, while the right eye served as a control. Monthly ophthalmological evaluations were conducted over a 3-month period. At the end of the follow-up, orbital magnetic resonance imaging (MRI) was performed. Vitreous humor samples were analyzed using spectrophotometric methods to determine total oxidant and antioxidant levels.

Results: Cataract formation was observed in two of the eight irradiated eyes (25%). The MRI analysis revealed a significant reduction in signal intensity within the left eye's aqueous humor in non-contrast sequences (p = 0.03), while an increase in signal intensity was observed in late post-contrast sequences (p = 0.04). Spectrophotometric analysis indicated that total oxidant levels (p = 0.04) and the oxidative stress index (p = 0.04) were significantly lower in the treatment group.

Conclusion: These findings suggest that radiation-induced changes in the vitreous humor and posterior ocular structures may influence the anterior chamber, contributing to the development of radiation-induced cataracts.