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Both gating and tracking can mitigate the deteriorating dosimetric impact of intrafraction translation during prostate stereotactic body radiotherapy (SBRT). However, their ability to manage intrafraction rotation has not yet been thoroughly investigated. The dosimetric accuracy of gating, MLC tracking and couch tracking to manage intrafraction prostate rotation was investigated.

Treatment plans for end-to-end tests of prostate SBRT with focal boosting were generated for a dynamic anthropomorphic pelvis phantom. The phantom applied internal lateral rotation (up to 25°) and coupled vertical and longitudinal translation of a radiochromic film stack that was used for dose measurements. Dose was delivered for each plan while the phantom applied motion according to three typical prostate motion traces without compensation (i), with gating (ii), with MLC tracking (iii) or with couch tracking (iv). Measured doses for the four motion compensation strategies were compared with the planned dose in terms of γ-index ues improved the dosimetric accuracy, but residual motion-related dose errors remained due to the lack of rotation correction.

Dose prediction using deep learning networks prior to radiotherapy might lead tomore efficient modality selections. The study goal was to predict proton and photon dose distributions based on the patient-specific anatomy and to assess their clinical usage for paediatric abdominal tumours.

Data from 80 patients with neuroblastoma or Wilms’ tumour was included. Pencil beam scanning (PBS) (5mm/ 3%) and volumetric-modulated arc therapy (VMAT) plans (5mm) were robustly optimized on the internal target volume (ITV). Separate 3-dimensional patch-based U-net networks were trained to predict PBS and VMAT dose distributions. Doses, planning-computed tomography images and relevant optimization masks (ITV, vertebra and organs-at-risk) of 60 patients were used for training with a 5-fold cross validation. The networks’ performance was evaluated by computing the relative error between planned and predicted dose-volume histogram (DVH) parameters for 20 inference patients. In addition, the organs-at-risk mean dose differen identifying the optimal radiotherapy technique when experience and/or resources are unavailable.

Comprehensive dosimetric analysis is required prior to the clinical implementation of pelvic MR-only sites, other than prostate, due to the limited number of site specific synthetic-CT (sCT) dosimetric assessments in the literature. This study aims to provide a comprehensive assessment of a deep learning-based, conditional generative adversarial network (cGAN) model for a large ano-rectal cancer cohort. The following challenges were investigated; T2-SPACE MR sequences, patient data from multiple centres and the impact of sex and cancer site on sCT quality.

RT treatment position CT and T2-SPACE MR scans, from two centres, were collected for 90 ano-rectal patients. A cGAN model trained using a focal loss function, was trained and tested on 46 and 44 CT-MR ano-rectal datasets, paired using deformable registration, respectively. VMAT plans were created on CT and recalculated on sCT. Dose differences and gamma indices assessed sCT dosimetric accuracy. A linear mixed effect (LME) model assessed the impact of centre, sex and cancer site.

A mean PTV D95% dose difference of 0.1% (range -0.5% to 0.7%) was found between CT and sCT. All gamma index (1%/1mm threshold) measurements were >99.0%. The LME model found the impact of modality, cancer site, sex and centre was clinically insignificant (effect ranges -0.4% and 0.3%). The mean dose difference for all OAR constraints was 0.1%.

Focal loss cGAN models using T2-SPACE MR sequences from multiple centres can produce generalisable, dosimetrically accurate sCTs for ano-rectal cancers.

Focal loss cGAN models using T2-SPACE MR sequences from multiple centres can produce generalisable, dosimetrically accurate sCTs for ano-rectal cancers.

To describe differences in healthcare resource utilization between patients treated with bilateral vs. unilateral neck radiation therapy (RT) for lateralized oropharyngeal cancer.

A propensity score matching strategy was used to identify two otherwise clinically similar cohorts of tonsillar cancer patients treated with either bilateral or unilateral neck RT. Cohorts were matched based on similar propensity scores for age, sex, ECOG performance status, pack-year smoking history, cT-category, cN-category, HPV-status, and use of concurrent chemotherapy. Selleckchem Olaparib Short term (from start of RT to 3months following end of RT) resource utilization included 1) outpatient supportive care visits, 2) hospital admission, and 3) interventions (feeding tube insertion and outpatient intravenous hydration). Long-term resource utilization included feeding tube dependency at 1-year.

Among 559 patients with tonsillar cancer treated between 2004-2017, propensity score matching identified a unilateral neck RT cohort (n=81) and bilateral neck RT cohort (n=81) with similar clinical and treatment characteristics. Bilateral neck RT was associated with a higher likelihood of hospitalization (33% vs 12%, p<0.01), outpatient IV hydration (33% vs 17%, p=0.03), and feeding tube insertion (33% vs 10%, p<0.001); a greater number of total days of hospitalization (110 vs 47days, p<0.01) and outpatient IV hydration (135 vs 72days, p=0.02); and higher total number of supportive clinic visits (1226 vs 1053days, p=0.04). In the long-term, bilateral RT was associated with higher rate of feeding tube dependency at 1-year (7% vs 0%, p<0.001).

Bilateral RT for tonsillar cancer resulted in significant increase in health resource utilization.

Bilateral RT for tonsillar cancer resulted in significant increase in health resource utilization.Basal stem cells fuel development, homeostasis, and regeneration of the epidermis. The proliferation and fate decisions of these cells are highly regulated by their microenvironment, including the basement membrane and underlying mesenchymal cells. Basal progenitors give rise to differentiated progeny that generate the epidermal barrier. Here, we present data that differentiated progeny also regulate the proliferation, differentiation, and migration of basal progenitor cells. Using two distinct mouse lines, we found that increasing contractility of differentiated cells resulted in non-cell-autonomous hyperproliferation of stem cells and prevented their commitment to a hair follicle lineage. This increased contractility also impaired movement of basal progenitors during hair placode morphogenesis and diminished migration of melanoblasts. These data suggest that intra-tissue tension regulates stem cell proliferation, fate decisions, and migration and that differentiated epidermal keratinocytes are a component of the stem cell niche that regulates development and homeostasis of the skin.