Cost-benefit analysis of advanced CBCT imaging: Incremental costs and savings.

Advanced CBCT systems can replace separate CT scans for offline adaptive radiotherapy (RT) but require higher investments costs compared to conventional CBCT systems. Therefore, a vendor-independent cost-benefit analysis was conducted, presenting the number of offline adaptive RT fractions required to offset the additional ownership costs of advanced CBCT systems.

Increasing patient comfort in palliative radiotherapy with a newly developed mattress: a nonrandomized clinical trial.

Background: In palliative radiotherapy, many patients experience discomfort and pain during treatment, particularly while lying on flat, hard treatment couches that are considered essential for accurate treatment delivery. Thin foam matts, often used for palliative treatments, can somewhat reduce discomfort, but they are frequently insufficient.

Aim: In this study a mattress was developed and investigated, with the aim to reduce pain during radiotherapy treatments without affecting treatment quality.

NTCP models based on CT-guided online adaptive SBRT for abdominal lymph node oligometastases.

Background And Purpose: This study prospectively analyzed the correlation between dose and toxicity in CT-guided online adaptive stereotactic body radiotherapy for abdominal and pelvic lymph node (A-P LN) oligometastases. The aim was to design an NTCP model to predict acute gastrointestinal (GI) toxicity.

Materials And Methods: Patients with oligometastatic A-P LN received 45 Gy in five fractions.

Selection of patients for proton therapy to reduce risk of second primary lung and breast cancer.

Aim: We previously published selection criteria for proton therapy (PT) in the Netherlands for breast cancer (BC) and thoracic lymphoma patients, based upon the Absolute Excess Risk (AER) for acute coronary events. The aim of the current paper was to define additional criteria to select BC and thoracic lymphoma patients for PT, to reduce the risk of second primary BC and lung cancer (LC).

Methods: Based on a literature review, we identified Excess Relative Risks (ERR)/Gy mean organ dose of second primary BC and LC, for selected patient groups.

Stereotactic Radiation Therapy or Protons for Uveal Melanoma Patients? An Artificial Intelligence (AI)-Based Clinical Treatment Decision-Making Tool Predicting Doses To Radiation Therapy Constraints.

Purpose: For ocular melanoma, selecting between stereotactic radiation therapy (SRT) and protons requires a lengthy plan comparison process. The purpose of this brief report is to describe an artificial intelligence (AI) decision-making tool to predict dosimetric and clinical outcomes based on easy-to-access tumor characteristics.

Methods And Materials: The AI tool was based on a retrospective database of 66 patients with uveal melanoma treated in a single center with robotic SRT.

A Novel Live-Cell Microscopy Platform for Real-Time Visualization of 53BP1 Foci Dynamics and Accurate Dosimetry in Proton Therapy.

Background And Purpose: Proton-induced cell death is primarily driven by the induction and repair of DNA double strand breaks. While DNA damage dynamics have been extensively studied, the early cellular responses to proton irradiation remain underexplored. To address this, we developed a novel live-cell microscopy platform that enables real-time visualization of cellular responses to DNA damage induced by proton therapy.

Afterloader integrated EMT enables improved dwell position model definition and quality assurance in Venezia gynaecological brachytherapy applicators.

In brachytherapy for gynecological cancers using intracavitary applicators, implant reconstruction is commonly performed using applicator libraries. These libraries contain applicator geometry models as well as dwell position (DP) models defined in respect to the applicator geometry. In this study, we investigate whether an afterloader integrated electromagnetic tracking (EMT) system can be utilized for DP model definition and quality assurance in such applicators.

Challenges and opportunities to minimize the dose in the neurovascular bundles during prostate radiotherapy.

Background And Purpose: Radiation damage to the neurovascular bundles (NVB) has been linked to erectile dysfunction after prostate cancer radiotherapy (PCa). NVB sparing using coplanar and non-coplanar automated treatment planning is presented here in two settings: (1) without compromising target coverage, (2) allowing target coverage compromise.

Material And Methods: 20 previously treated patients with localized PCa.

A planning approach for online adaptive proton therapy to cope with cone beam computed tomography inaccuracies.

Background And Purpose: In online-adaptive proton therapy planning based on cone beam computed tomography (CBCT), CT number errors can pose challenges. We propose an approach for coping with CT number uncertainties by increasing range robustness settings (RRS) in online-adaptive planning. This was compared to our trigger-based offline (TB-Offline) adaptive approach, and to daily replanning using in-room CT-on-rails (CTOR).

Requirements and Study Design for the Next Proton FLASH Clinical Trials: an International Multidisciplinary Delphi Consensus.

Purpose: The FLASH effect, defined as normal tissue sparing while maintaining tumor control with ultra-high dose-rate irradiation, has been demonstrated preclinically in different tumors and tissues. Although the biological mechanisms are unclear, there is a need for clinical trials investigating the value of proton FLASH irradiation (pFLASH). The purpose of this study was to establish an expert consensus regarding prerequisites, study design, and endpoints for the next clinical trials exploring the clinical potentials of pFLASH.

Reducing Number of Treatment Fractions for Patients With Abdominal Lymph Node Oligometastases: The Need for Online Adaptive Radiation Therapy to Provide Personalized Adaptive Fractionation.

Purpose: The aim of this in silico trial was to explore using online adaptive radiation therapy (OART) for isotoxic personalized fractionation and in-treatment dose adaptation for patients with abdominal-pelvic lymph node oligometastases. We hypothesized that this method could significantly reduce treatment fractions, increase treatment capacity, and improve patient comfort.

Methods And Materials: Twenty patients with abdominal-pelvic lymph node metastases from a phase 2 study (STEAL, NL58442.

Computed Tomography Guided Online Adaptive Stereotactic Body Radiation Therapy for Lymph Node Oligometastases: Impact on Dose to Target and Organs at Risk.

Purpose: This study investigates the radiation dose in abdominal and pelvic lymph node oligometastases (A-P LN) and gastrointestinal organs (GIOs) of patients undergoing computed tomography (CT) guided online adaptive stereotactic body radiation therapy in a phase 2 study. The study aimed to increase the dose to the target iso-toxically.

Methods And Materials: Patients with oligometastatic A-P LN received 45 Gy in 5 fractions on the CyberKnife.

A deep learning model for inter-fraction head and neck anatomical changes in proton therapy.

To assess the performance of a probabilistic deep learning based algorithm for predicting inter-fraction anatomical changes in head and neck patients.A probabilistic daily anatomy model (DAM) for head and neck patients DAM (DAM) is built on the variational autoencoder architecture. The model approximates the generative joint conditional probability distribution of the repeat computed tomography (rCT) images and their corresponding masks on the planning CT images (pCT) and their masks.

Neurovascular bundle sparing in hypofractionated radiotherapy maintained with realistic treatment uncertainties.

Background And Purpose: Erectile dysfunction is a common side effect of radiotherapy for prostate cancer. To mitigate this toxicity, it has been suggested to limit the dose to critical nerves and vessels. We investigated the feasibility of sparing the neuro-vascular bundles (NVBs) in stereotactic body radiotherapy under the impact of realistic treatment uncertainties.

Treatment-related toxicity, utility and patient-reported outcomes of head and neck cancer patients treated with proton therapy: A longitudinal study.

Objective: In comparison to current standard photon irradiation, proton therapy (PT) significantly reduces dose to the surrounding normal tissue and therefore is expected to reduce toxicity and improve health related quality of life (HRQoL). Despite the high expectations of PT, there is very limited data on patients' HRQoL after radiotherapy. This study evaluated HRQoL in head and neck cancer (HNC) patients receiving PT and established a robust benchmark for future comparison of PT and the radiotherapy advancements.

First-in-Men Online Adaptive Robotic Stereotactic Body Radiation Therapy: Toward Ultrahypofractionation for High-Risk Prostate Cancer Patients.

Purpose: Ultrahypofractionation presents challenges for a subset of high-risk prostate cancer patients due to the large planning target volume (PTV) margin required for the seminal vesicles. Online adaptive radiation therapy could potentially reduce this margin. This paper focuses on the development, preclinical validation, and clinical testing of online adaptive robotic stereotactic body radiation therapy for this patient group.

Results of a Single-Arm Phase 2 Clinical Trial: Online Adaptive Stereotactic Body Radiation Therapy for Abdominal-Pelvic Oligometastases.

Purpose: This study reports on the clinical outcomes of the single-arm phase-2 STEAL trial investigating online adaptive stereotactic body radiation therapy (SBRT) for abdominal-pelvic lymph node (A-P LN) oligometastases.

Methods And Materials: Patients with oligometastatic A-P LN were enrolled and treated to a total dose of 45 Gy in 5 fractions on the CyberKnife. For each patient, a library of 3 plans was created using a pretreatment diagnostic computed tomography (CT) scan and the treatment planning CT scan.

Margin and robustness settings for a library-of-plans IMPT strategy for locally advanced cervical cancer.

This study aims to determine a margin and robustness setting for treating locally advanced cervical cancer (LACC) with a library-of-plans (LoP) based online-adaptive intensity-modulated proton therapy (IMPT).We analyzed 13 LACC patients with delineated planning and weekly repeat CT scans (reCTs). For each patient, 120 IMPT treatments of 25 fractions were simulated with a LoPs approach.

Evaluating and reporting LET and RBE-weighted dose in proton therapy for glioma - The Dutch approach.

Background And Purpose: With proton therapy, the relative biological effectiveness (RBE) accounts for increased DNA damage caused by higher linear energy transfer (LET) compared to photons. However, the LET and hence the RBE varies along the proton range, particularly at the Bragg peak, introducing challenges in proton treatment planning for brain tumors. The aim of this paper is to standardize evaluating and reporting LET and RBE in proton therapy for patients with grade 2 and 3 IDH mutant gliomas among the Dutch proton therapy centers.

Stereotactic body radiation therapy on abdominal-pelvic lymph node oligometastases: a systematic review on toxicity.

Background And Purpose: To review available data on toxicity during and/or after treatment of abdominal-pelvic lymph node oligometastases (A-P LN) with stereotactic body radiation therapy (SBRT) and to provide an overview of adverse events and its relation to dose or fractionation.

Material And Methods: For this systematic review, we searched MEDLINE, Embase, Web of Science Core Collection, and CINAH for studies published between the database inception and October 3rd, 2023. Inclusion criteria were (1) patients with 1-5 A-P LN oligometastases, (2) treatment with SBRT to a median prescribed dose of ≥55 Gy BED10, and (3) description of acute and/or late toxicity.

Dosimetric advantages of adaptive IMPT vs. Enhanced workload and treatment time - A need for automation.

Introduction: In head-and-neck IMPT, trigger-based offline plan adaptation (Offline) is often used. Our goal was to compare this to four alternative adaptive strategies for dosimetry, workload and treatment time, considering also foreseen further technological advancements, including anticipated automation.

Materials And Methods: Alternative strategies included weekly offline re-planning (Offline), daily plan selection from a library (Library and Library) and a fast, approximate daily online re-optimization approach (Online).

Assessment of integrated electromagnetic tracking for dwell position monitoring in a clinical HDR brachytherapy setting for prostate cancer.

Background: Electromagnetic Tracking (EMT) technology has been integrated in a prototype high-dose-rate brachytherapy (HDR-BT) afterloading device. Its potential for dwell position (DP) monitoring has earlier been demonstrated in prostate phantoms. However, its performance for prostate BT in the clinical setting remains to be assessed.

A probabilistic evaluation of the Dutch robustness and model-based selection protocols for Head-and-Neck IMPT: A multi-institutional study.

Background And Purpose: In the Netherlands, 2 protocols have been standardized for PT among the 3 proton centers: a robustness evaluation (RE) to ensure adequate CTV dose and a model-based selection (MBS) approach for IMPT patient-selection. This multi-institutional study investigates (i) inter-patient and inter-center variation of target dose from the RE protocol and (ii) the robustness of the MBS protocol against treatment errors for a cohort of head-and-neck cancer (HNC) patients treated in the 3 Dutch proton centers.

Materials And Methods: Clinical treatment plans of 100 HNC patients were evaluated.