Background/objectives: Studies have shown that dose to the parotid gland stem cell rich (SCR) regions should be reduced to lower the risk of xerostomia after radiotherapy (RT). This study aimed to assess whether stem cell sparing (SCS)-RT can be adopted in routine clinical practice.
Methods: Multiple planning studies were performed to compare SCS-RT with standard (ST)-RT using 30 head and neck cancer patients.
Purpose: To assess the feasibility and benefit of NTCP optimized aspiration-prevention treatment planning by sparing specific aspiration related organs at risk, and to assess the impact of baseline complaints on the planning results.
Materials And Methods: This in silico planning study included 30 HNC patients who were previously treated with definitive radiotherapy. New fully automated plans, allowing for sparing specific aspiration related organs at risk, were optimised directly on normal tissue complication probability (NTCP) models for common toxicities: xerostomia and dysphagia.
Underwater noise data were collected from 84 pile drives during bridge construction at various sites in Florida. These data were used to develop an empirically based model for underwater transmission loss associated with root mean squared, peak, and sound exposure level values. The model was verified using readings from other datasets as well as data from this study, and it appeared to reproduce reported transmission loss coefficient values well when data were curated to match data used in the empirical model's development and limited to situations where robust data were used in model development.
View Article and Find Full Text PDFMost drugs that target the complement system are designed to inhibit the complement pathway at either the proximal or terminal levels. The use of a natural complement regulator such as factor H (FH) could provide a superior treatment option by restoring the balance of an overactive complement system while preserving its normal physiological functions. Until now, the systemic treatment of complement-associated disorders with FH has been deemed unfeasible, primarily due to high production costs, risks related to FH purified from donors' blood, and the challenging expression of recombinant FH in different host systems.
View Article and Find Full Text PDFBackground And Purpose: Recently, a comprehensive xerostomia prediction model was published, based on baseline xerostomia, mean dose to parotid glands (PG) and submandibular glands (SMG). Previously, PET imaging biomarkers (IBMs) of PG were shown to improve xerostomia prediction. Therefore, this study aimed to explore the potential improvement of the additional PET-IBMs from both PG and SMG to the recent comprehensive xerostomia prediction model (i.
View Article and Find Full Text PDFPurpose/objective: Chemo-radiotherapy can improve the oncological outcome of esophageal cancer (EC) patients, but may cause long term radiation-induced toxicity, including an increased risk of non-cancer related death. For lung cancer patients, a model to predict 2-year total mortality using mean heart dose (MHD) and gross tumor volume (GTV) has previously been developed and validated. This project aimed to externally validate this model in EC patients.
View Article and Find Full Text PDFFabry disease (FD, OMIM 301500) is a rare X-linked inherited lysosomal storage disorder associated with reduced activities of α-galactosidase A (aGal, EC 3.2.1.
View Article and Find Full Text PDFBackground And Purpose: Adaptive radiotherapy (ART) is workload intensive but only benefits a subgroup of patients. We aimed to develop an efficient strategy to select candidates for ART in the first two weeks of head and neck cancer (HNC) radiotherapy.
Materials And Methods: This study retrospectively enrolled 110 HNC patients who underwent modern photon radiotherapy with at least 5 weekly in-treatment re-scan CTs.
Purpose: Normal tissue complication probability (NTCP) models can be used to estimate the risk of radiation pneumonitis (RP). The aim of this study was to externally validate the most frequently used prediction models for RP, i.e.
View Article and Find Full Text PDFPurpose: Despite improvements to treatment, patients with head and neck cancer (HNC) still experience radiation-induced xerostomia due to salivary gland damage. The stem cells of the parotid gland (PG), concentrated in the gland's main ducts (stem cell rich [SCR] region), play a critical role in the PG's response to radiation. Treatment optimization requires a dose metric that properly accounts for the relative contributions of dose to this SCR region and the PG's remainder (non-SCR region) to the risk of xerostomia in normal tissue complication probability (NTCP) models for xerostomia.
View Article and Find Full Text PDFBackground: Normal-tissue complication probability (NTCP) models predict complication risk in patients receiving radiotherapy, considering radiation dose to healthy tissues, and are used to select patients for proton therapy, based on their expected reduction in risk after proton therapy versus photon radiotherapy (ΔNTCP). Recommended model evaluation measures include area under the receiver operating characteristic curve (AUC), overall calibration (CITL), and calibration slope (CS), whose precise relation to patient selection is still unclear. We investigated how each measure relates to patient selection outcomes.
View Article and Find Full Text PDFPurpose: In the Netherlands, oesophageal cancer (EC) patients are selected for intensity modulated proton therapy (IMPT) using the expected normal tissue complication probability reduction (ΔNTCP) when treating with IMPT compared to volumetric modulated arc therapy (VMAT). In this study, we evaluate the robustness of the first EC patients treated with IMPT in our clinic in terms of target and organs-at-risk (OAR) dose with corresponding NTCP, as compared to VMAT.
Materials And Methods: For 20 consecutive EC patients, clinical IMPT and VMAT plans were created on the average planning 4DCT.
Int J Radiat Oncol Biol Phys
November 2022
Stem cells are types of cells that have unique ability to self-renew and to differentiate into more than one cell lineage. They are considered building blocks of tissues and organs. Over recent decades, they have been studied and utilized for repair and regenerative medicine.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
July 2022
Background: Therapeutic apheresis (TA) is based on the principles of either removing dissolved pathogenic substances (e.g., antibodies) from the blood plasma or replacing plasma factors.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
April 2022
Selection of head and neck cancer (HNC) patients for proton therapy (PT) using plan comparison (VMAT vs. IMPT) for each patient is labor-intensive. Our aim was to develop a decision support tool to identify patients with high probability to qualify for PT, at a very early stage (immediately after delineation) to avoid delay in treatment initiation.
View Article and Find Full Text PDFBackground: Clinical prediction models are developed widely across medical disciplines. When predictors in such models are highly collinear, unexpected or spurious predictor-outcome associations may occur, thereby potentially reducing face-validity of the prediction model. Collinearity can be dealt with by exclusion of collinear predictors, but when there is no a priori motivation (besides collinearity) to include or exclude specific predictors, such an approach is arbitrary and possibly inappropriate.
View Article and Find Full Text PDFAims: Proton therapy is a radiation technique that yields less dose in normal tissues than photon therapy. In the Netherlands, proton therapy is reimbursed if the reduced dose to normal tissues is predicted to translate into a prespecified reduction in toxicity, based on nationally approved validated models. The aim of this paper is to present the development of a national indication protocol for proton therapy (NIPP) for model-based selection of breast cancer patients and to report on first clinical experiences.
View Article and Find Full Text PDFLogging causes changes in habitat structure, which can potentially lead to variations in taxonomic and functional richness of biodiversity. Studies on how functional traits in birds are affected by logging operations can provide an important element for the understanding of ecosystem processes. In this paper, we examined how logging in subtropical Andean forests influenced taxonomic and functional diversity of cavity-nesting birds.
View Article and Find Full Text PDF