How to protect the proximal bronchial tree during stereotactic radiotherapy of ultracentral lung tumors: Lessons from MR-guided treatment.

Purpose: To use imaging data from stereotactic MR-guided online adaptive radiotherapy (SMART) of ultracentral lung tumors (ULT) for development of a safe non-adaptive approach towards stereotactic body radiotherapy (SBRT) of ULT.

Patients And Methods: Analysis is based on 19 patients with ULT who received SMART (10 × 5.0-5.

The sarcoma ring trial: a case-based analysis of inter-center agreement across 21 German-speaking sarcoma centers.

Purpose: The management of soft tissue sarcoma (STS) at reference centers with specialized multidisciplinary tumor boards (MTB) improves patient survival. The German Cancer Society (DKG) certifies sarcoma centers in German-speaking countries, promoting high standards of care. This study investigated the variability in treatment recommendations for localized STS across different German-speaking tertiary sarcoma centers.

Evaluation of Pelvic MRI-to-CT Deformable Registration for Adaptive MR-Guided Particle Therapy.

Purpose: We aim to assess the magnetic resonance imaging (MRI)-to-CT deformable image registration (DIR) quality of our treatment planning system in the pelvic region as the first step of an online MRI-guided particle therapy clinical workflow.

Materials And Methods: Using 2 different DIR algorithms, ANAtomically CONstrained Deformation Algorithm (ANACONDA), the DIR algorithm incorporated in RayStation, and Elastix, an open-source registration software, we retrospectively assessed the quality of the deformed CT (dCT) generation in the pelvic region for 5 patients. T1- and T2-weighted daily control MRI acquired prior to treatment delivery were used for the DIR.

Definition of a framework for volumetric modulated arc therapy plan quality assessment with integration of dose-, complexity-, and robustness metrics.

Background And Purpose: Conventionally, the quality of radiotherapy treatment plans is assessed through visual inspection of dose distributions and dose-volume histograms. This study developed a framework to evaluate plan quality using dose, complexity, and robustness metrics. Additionally, a method for predicting plan robustness metrics using dose and complexity metrics was introduced for cases where plan robustness evaluation is unavailable or impractical.

Detection of an internal density change in an anthropomorphic head phantom via tracking of charged nuclear fragments in carbon-ion radiotherapy.

Background: Carbon-ion radiotherapy provides steep dose gradients that allow the simultaneous application of high tumor doses as well as the sparing of healthy tissue and radio-sensitive organs. However, even small anatomical changes may have a severe impact on the dose distribution because of the finite range of ion beams.

Purpose: An in-vivo monitoring method based on secondary-ion emission could potentially provide feedback about the patient anatomy and thus the treatment quality.

Mixed- and multi-relative biological effectiveness model simultaneous optimization in carbon ion radiotherapy: A proof-of-concept.

Background And Purpose: In carbon ion radiotherapy (CIRT), different relative biological effectiveness (RBE) models have been used for calculating RBE-weighted dose (D). Conversion between current RBE predictions and introduction of novel approaches remains a challenging task. Our aim is to introduce a framework considering multiple RBE models simultaneously during CIRT plan optimization, easing the translation between D prescriptions.

Second Comment on 'Modeling for predicting survival fraction of cells after ultra-high dose rate irradiation'.

We comment on the reply by Shiraishito our comments regarding their recently published study 'Modeling for Predicting Survival Fraction of Cells after Ultra-High Dose Rate Irradiation'. While we appreciate the effort of the authors to consider our comments, we see ourselves compelled to add another short comment as we believe that some of our suggestions have been misrepresented. This may have resulted in a misguiding re-evaluation of the model.

Investigating LETd optimization strategies in carbon ion radiotherapy for pancreatic cancer: a dosimetric study using an anthropomorphic phantom.

Background: Clinical carbon ion beams offer the potential to overcome hypoxia-induced radioresistance in pancreatic tumors, due to their high dose-averaged Linear Energy Transfer (LETd), as previous studies have linked a minimum LETd within the tumor to improved local control. Current clinical practices at the Heidelberg Ion-Beam Therapy Center (HIT), which use two posterior beams, do not fully exploit the LETd advantage of carbon ions, as the high LETd is primarily focused on the beams' distal edges. Different LETd-boosting strategies, such as Spot-scanning Hadron Arc (SHArc), could enhance LETd distribution by concentrating high-LETd values in potential hypoxic tumor cores while sparing organs at risk.

Bimodal intensity-modulated radiotherapy in combination with carbon ion therapy (C12) of mucosal melanomas - data of the last decade from Heidelberg University Hospital.

Introduction: Due to the rarity of mucosal melanomas, few recent studies can be found investigating the success and side effects of therapy for this entity with large numbers of patients. In this retrospective analysis, the efficacy and toxicity of combined intensity-modulated radiotherapy (IMRT) and carbon ion therapy (C12) of mucosal melanomas were analyzed to contribute to a better understanding of this rare disease.

Methods: Twenty-two patients were included from 2013 to 2022 in the Department of Radiation Oncology at Heidelberg University Hospital.

Spatio-temporal transcriptomics of chromothriptic SHH-medulloblastoma identifies multiple genetic clones that resist treatment and drive relapse.

Paediatric medulloblastomas with chromothripsis are characterised by high genomic instability and are among the tumours with the worst prognosis. However, the molecular makeup and the determinants of the aggressiveness of chromothriptic medulloblastoma are not well understood. Here, we apply spatial transcriptomics to profile a cohort of 13 chromothriptic and non-chromothriptic medulloblastomas from the same molecular subgroup.

Radiotherapy Effects on Airway Management in Patients with Nasopharyngeal Cancer.

: At present, there is a paucity of data in the literature pertaining to the impact of radiotherapy (RT) on the success of tracheal intubation in patients with nasopharyngeal cancer (NPC). The aim of this study is to investigate the frequency of difficult tracheal intubation in patients with NPC following RT. : Patients with NPC who underwent RT followed by surgery between 2012 and April 2024 at the University Hospital Heidelberg were retrospectively analyzed.

Oxygen consumption measurements at ultra-high dose rate over a wide LET range.

Background: The role of radiolytic oxygen consumption for the in-vitro "Ultra-High Dose Rate" (UHDR) sparing and in-vivo FLASH effect is subject to active debate, but data on key dependencies such as the radiation quality are lacking.

Purpose: The influence of "dose-averaged Linear Energy Transfer" (LETd) and dose rate on radiolytic oxygen consumption was investigated by monitoring the oxygen concentration during irradiation with electrons, protons, helium, carbon, and oxygen ions at UHDR and "Standard Dose Rates" (SDR).

Methods: Sealed "Bovine Serum Albumin" (BSA) 5% samples were exposed to 15 Gy of electrons and protons, and for the first time helium, carbon, and oxygen ions with LETd values of 1, 5.

Inhomogeneity detection within a head-sized phantom using tracking of charged nuclear fragments in ion beam therapy.

The highly conformal carbon-ion radiotherapy is associated with an increased sensitivity of the dose distributions to internal changes in the patient during the treatment course. Hence, monitoring methodologies capable of detecting such changes are of vital importance. We established experimental setup conditions to address the sensitivity of a monitoring approach based on secondary-fragment tracking for detecting clinically motivated air cavity dimensions in a homogeneous head-sized PMMA phantom in 40 mm depth.

A model-based risk-minimizing proton treatment planning concept for brain injury prevention in low-grade glioma patients.

Purpose: Late-occurring contrast-enhancing brain lesions (CEBLs) have been observed on MRI follow-up in low-grade glioma (LGG) patients post-proton therapy. Predictive risk-models for this endpoint identified a dose-averaged linear energy transfer (LET)-dependent proton relative biological effectiveness (RBE) effect on CEBL occurrence and increased radiosensitivity of the cerebral periventricular region (VP). This work aimed to design a stable risk-minimizing treatment planning (TP) concept addressing these intertwined risk factors through a classically formulated optimization problem.

Stereotactic Radiosurgery for 1-10 Brain Metastases to avoid Whole-Brain Radiotherapy - Results of the CYBER-SPACE Randomized Phase 2 Trial.

Background: Stereotactic Radiosurgery (SRS) is an emerging alternative to whole-brain radiotherapy (WBRT) for treating multiple brain metastases (BM), reducing toxicity and improving tumor control. The CYBER-SPACE trial compared SRS based on either SPACE or MPRAGE MRI sequence for avoiding or delaying WBRT in patients with 1-10 BM.

Methods: Patients with 1-10 untreated BM were randomized 1:1 to receive SRS of all lesions based on either SPACE or MPRAGE MRI sequences.

Experimental validation of a FLUKA Monte Carlo simulation for carbon-ion radiotherapy monitoring via secondary ion tracking.

Background: In-vivo monitoring methods of carbon ion radiotherapy (CIRT) includes explorations of nuclear reaction products generated by carbon-ion beams interacting with patient tissues. Our research group focuses on in-vivo monitoring of CIRT using silicon pixel detectors. Currently, we are conducting a prospective clinical trial as part of the In-Vivo Monitoring project (InViMo) at the Heidelberg Ion Beam Therapy Center (HIT) in Germany.

MR-linac based radiation therapy in gastrointestinal cancers: a narrative review.

Background And Objective: Magnetic resonance guided radiotherapy (MRgRT) is an emerging technological innovation with more and more institutions gaining clinical experience in this new field of radiation oncology. The ability to better visualize both tumors and healthy tissues due to excellent soft tissue contrast combined with new possibilities regarding motion management and the capability of online adaptive radiotherapy might increase tumor control rates while potentially reducing the risk of radiation-induced toxicities. As conventional computed tomography (CT)-based image guidance methods are insufficient for adaptive workflows in abdominal tumors, MRgRT appears to be an optimal method for this tumor site.

Carbon Ion Beam Radiation Therapy as Part of a Trimodal Therapy for Non-small Cell Superior Sulcus Tumors: The INKA Study.

Purpose: Superior sulcus tumors are frequently treated with neoadjuvant chemoradiation therapy (nCRT) followed by surgery via a trimodal approach. The INKA study evaluated the replacement of photon irradiation by carbon ion radiation therapy (C12-RT) in this regimen.

Methods And Materials: The prospective INKA study included patients with locally advanced non-small cell superior sulcus tumors ( View Article and Find Full Text PDF

Early circulating tumor DNA changes predict outcomes in head and neck cancer patients under re-radiotherapy.

Local recurrence after radiotherapy is common in locally advanced head and neck cancer (HNC) patients. Re-irradiation can improve local disease control, but disease progression remains frequent. Hence, predictive biomarkers are needed to adapt treatment intensity to the patient's individual risk.

Impact of Radiotherapy on Endotracheal Intubation Quality Metrics in Patients with Esophageal Cancer: A Challenge for Advanced Airway Management?

(1) Background: Currently, no data are available in the literature investigating the influence of radiotherapy (RT) on endotracheal intubation success in patients with esophageal cancer. This study aims to evaluate the impact of RT on endotracheal intubation quality metrics in patients with esophageal cancer. (2) Methods: Patients with esophageal cancer who underwent RT followed by surgery between 2012 and 2023 at the University Hospital Heidelberg, Germany, were retrospectively analyzed.

Carbon ion beam dosimetry in magnetic fields using Farmer-type ionization chambers of different radii: measurements and simulations.

To investigate magnetic field effects on the dose distribution and ionization chambers response in carbon ion reference fields and determine magnetic field correction factors for chambers of different volumes.The response of six Farmer-type chambers with varying radii (1-6 mm, termed as R1-R6) was measured in magnetic fields up to 1 T in 0.1 T increments using an experimental electromagnet and compared with Monte Carlo simulations.

Particle arc therapy: Status and potential.

There is a rising interest in developing and utilizing arc delivery techniques with charged particle beams, e.g., proton, carbon or other ions, for clinical implementation.