Validated prediction of xerostomia in a real-world population: a step toward model-guided radiotherapy.

Background And Purpose: The aim of this study is to validate an Normal Tissue Complication Probability (NTCP) model for xerostomia in a large quality-registry cohort, enabling its future use in individualized NTCP-based treatment planning.

Material And Methods: A model predicting grade ≥ 2 xerostomia (6 months post-radiotherapy) was selected for validation, including the mean dose to both the parotid and the submandibular glands, in addition to the baseline score for xerostomia, as predictors. Our local validation cohort consisted of 674 patients (204 events), treated between 2012 and 2024, with a median follow-up of 10.

Dose-response mapping of bladder and rectum in prostate cancer patients undergoing radiotherapy with and without baseline toxicity correction.

Background And Purpose: Radiotherapy dose-response maps (DRM) combine dose-surface maps (DSM) and toxicity outcomes to identify high-risk subregions in organ-at-risk. This study assesses the impact of baseline toxicity correction on the identification of high-risk subregions in dose-response modeling for prostate cancer patients undergoing radiotherapy.

Materials And Methods: The analysis included 1808 datasets, with 589 exclusions before toxicity-specific data removal.

Integrating genetic polymorphisms and clinical data to develop predictive models for skin toxicity in breast cancer radiation therapy.

Background: We aim to develop and validate predictive models for acute and late skin toxicity in breast cancer (BC) patients undergoing radiation therapy (RT). Models incorporate a genetic profile-comprising candidate single nucleotide polymorphisms (SNPs) in non-coding RNAs and previously reported toxicity-associated variants-combined with clinical variables.

Methods: The study involved 1979 BC patients monitored for two to eight years post-RT in a multi-centre study.

Patient-specific microvascular computational modeling for estimating radiotherapy outcomes.

This study presents a personalized computational framework for modeling the vascular microenvironment in head-and-neck cancer patients and evaluating the impact of microvasculature on radiotherapy outcomes. We first perform a population-based calibration of a microvascular model using data collected with a sublingual microscope from 62 patients, creating synthetic networks that capture microvascular features with a population-based approach. The calibrated models accurately reproduce key physiological parameters, such as red blood cells velocity, aligning with clinical data.

A Polygenic Risk Score for Late Bladder Toxicity Following Radiotherapy for Non-Metastatic Prostate Cancer.

Background: Late bladder toxicity is a concern for patients receiving prostate cancer radiotherapy and negatively affects survivors. Few risk factors are known beyond the radiation dose and volume of bladder exposed. A polygenic risk score (PRS) could identify susceptible patients.

New rectum dose surface mapping methodology to identify rectal subregions associated with toxicities following prostate cancer radiotherapy.

Background And Purpose: Growing evidence suggests that spatial dose variations across the rectal surface influence toxicity risk after radiotherapy. Existing methodologies employ a fixed, arbitrary physical extent for rectal dose mapping, limiting their analysis. We developed a method to standardise rectum contours, unfold them into 2D cylindrical surface maps, and identify subregions where higher doses increase rectal toxicities.

Association of radiation-induced normal tissue toxicity with a high genetic risk for rheumatoid arthritis.

Background: Overlapping genes are involved with rheumatoid arthritis (RA) and DNA repair pathways. Therefore, we hypothesized that patients with a high polygenic risk score for RA will have an increased risk of radiotherapy toxicity given the involvement of DNA repair.

Methods: Primary analysis was performed on 1494 prostate cancer, 483 lung cancer, and 1820 breast cancer patients assessed for development of radiotherapy toxicity in the REQUITE (validating pREdictive models and biomarkers of radiotherapy toxicity to reduce side effects and improve QUalITy of lifE in cancer survivors) study.

Professional-patient discrepancies in assessing lung cancer radiotherapy symptoms: An international multicentre study.

Background And Purpose: We investigate discrepancies in the assessment of treatment-related symptoms in lung cancer between healthcare professionals and patients, and factors contributing to these discrepancies.

Materials And Methods: Data from 515 participants in the REQUITE study were analysed. Five symptoms (cough, dyspnoea, bronchopulmonary haemorrhage, chest wall pain, dysphagia) were evaluated both before and after radiotherapy.

Training and temporally validating an NTCP model of acute toxicity after whole breast radiotherapy, including the impact of advanced delivery techniques.

Purpose: The aim is to train and validate a multivariable Normal Tissue Complication Probability (NTCP) model predicting acute skin reactions in patients with breast cancer receiving adjuvant Radiotherapy (RT).

Methods And Materials: We retrospectively reviewed 1570 single-institute patients with breast cancer treated with whole breast irradiation (40 Gy/15fr). The patients were divided into training (n = 878, treated with 3d-CRT, from 2009 to 2017) and validation cohorts (n = 692, treated from 2017 to 2021, including advanced RT techniques).

Fat necrosis after accelerated partial breast irradiation or hypofractionated whole breast irradiation: A case-control study.

Purpose: This study aimed to compare the incidence of fat necrosis after accelerated partial breast irradiation (APBI) vs hypofractionated whole breast irradiation (WBI) in patients with early-stage breast cancer.

Materials And Methods: Data from early-stage breast cancer patients who underwent breast-conserving surgery and adjuvant radiotherapy between 2009 and 2022 were retrospectively collected. Radiation therapy consisted of APBI of 30 Gy in 5 daily fractions (Fx) (delivered in one week, consecutively) to the tumour bed or WBI (42.

Impact of kV-cone beam computed tomography dose on DNA repair mechanisms: A pilot study.

Purpose: In head and neck squamous cell carcinoma (HNSCC), early complications of the radiotherapy (RT) are observed from the beginning of the treatment to a few months after its end. During external radiotherapy treatment, several patient-dependent parameters can cause a modification of the dose distribution compared to the planned distribution due to variation in patient positioning, anatomy, or intra-fractional movements for example. To verify these parameters during treatment sessions, one of the most commonly used solutions is the cone-beam computed tomography (CBCT).

Intestinal microbiota composition is predictive of radiotherapy-induced acute gastrointestinal toxicity in prostate cancer patients.

Background: The search for factors beyond the radiotherapy dose that could identify patients more at risk of developing radio-induced toxicity is essential to establish personalised treatment protocols for improving the quality-of-life of survivors. To investigate the role of the intestinal microbiota in the development of radiotherapy-induced gastrointestinal toxicity, the MicroLearner observational cohort study characterised the intestinal microbiota of 136 (discovery) and 79 (validation) consecutive prostate cancer patients at baseline radiotherapy.

Methods: Gastrointestinal toxicity was assessed weekly during RT using CTCAE.

Reporting Standards for Complication Studies of Radiation Therapy for Pediatric Cancer: Lessons From PENTEC.

The major aim of Pediatric Normal Tissue Effects in the Clinic (PENTEC) was to synthesize quantitative published dose/-volume/toxicity data in pediatric radiation therapy. Such systematic reviews are often challenging because of the lack of standardization and difficulty of reporting outcomes, clinical factors, and treatment details in journal articles. This has clinical consequences: optimization of treatment plans must balance between the risks of toxicity and local failure; counseling patients and their parents requires knowledge of the excess risks encountered after a specific treatment.

Pelvic bone marrow dose-volume predictors of late lymphopenia following pelvic lymph node radiation therapy for prostate cancer.

Background And Purpose: Given the substantial lack of knowledge, we aimed to assess clinical/dosimetry predictors of late hematological toxicity on patients undergoing pelvic-nodes irradiation (PNI) for prostate cancer (PCa) within a prospective multi-institute study.

Materials And Methods: Clinical/dosimetry/blood test data were prospectively collected including lymphocytes count (ALC) at baseline, mid/end-PNI, 3/6 months and every 6 months up to 5-year after PNI. DVHs of the Body, ileum (BMILEUM), lumbosacral spine (BMLS), lower pelvis (BMPELVIS), and whole pelvis (BMTOT) were extracted.

Comparing Performances of Predictive Models of Toxicity after Radiotherapy for Breast Cancer Using Different Machine Learning Approaches.

Purpose: Different ML models were compared to predict toxicity in RT on a large cohort (n = 1314).

Methods: The endpoint was RTOG G2/G3 acute toxicity, resulting in 204/1314 patients with the event. The dataset, including 25 clinical, anatomical, and dosimetric features, was split into 984 for training and 330 for internal tests.

Quality of Life Longitudinal Evaluation in Prostate Cancer Patients from Radiotherapy Start to 5 Years after IMRT-IGRT.

Purpose: The purpose of this study is to study the evolution of quality of life (QoL) in the first 5 years following Intensity-modulated radiation therapy (IMRT) for prostate cancer (PCa) and to determine possible associations with clinical/treatment data.

Material And Methods: Patients were enrolled in a prospective multicentre observational trial in 2010-2014 and treated with conventional (74-80 Gy, 1.8-2 Gy/fr) or moderately hypofractionated IMRT (65-75.

Improving Pediatric Normal Tissue Radiation Dose-Response Modeling in Children With Cancer: A PENTEC Initiative.

The development of normal tissue radiation dose-response models for children with cancer has been challenged by many factors, including small sample sizes; the long length of follow-up needed to observe some toxicities; the continuing occurrence of events beyond the time of assessment; the often complex relationship between age at treatment, normal tissue developmental dynamics, and age at assessment; and the need to use retrospective dosimetry. Meta-analyses of published pediatric outcome studies face additional obstacles of incomplete reporting of critical dosimetric, clinical, and statistical information. This report describes general methods used to address some of the pediatric modeling issues.

Worsening of 2-year patient-reported intestinal functionality after radiotherapy for prostate cancer including pelvic node irradiation.

Background And Purpose: To quantify patient-reported 2-year intestinal toxicity (IT) from pelvic nodal irradiation (PNI) for prostate cancer. The association between baseline/acute symptoms and 2-year worsening was investigated.

Materials And Methods: Patient-reported IT was prospectively assessed through the Inflammatory Bowel Disease Questionnaire (IBDQ), filled in at baseline, radiotherapy mid-point and end, at 3 and 6 months and every 6 months until 5 years.