Survival Impact of Cardiac Dose Following Lung Stereotactic Body Radiotherapy.

INTRODUCTION: The purpose of this study was to determine the impact of radiation dose to substructures of the heart in lung stereotactic body radiotherapy (SBRT) patients on non-cancer-related deaths. METHODS: Patients treated with lung SBRT at a single institution from 2005 to 2013 were included. The heart and its substructures were contoured, and dose was calculated including mean, max, and max 10 cc dose. Clinical variables including stage, histology, age, gender, Charlson comorbidity index (CCI), preexisting cardiac disease, pulmonary function (forced expiratory volume in 1 second, diffusion capacity), and smoking status were explored for association with non-cancer-related deaths in univariable (UVA) and multivariable (MVA) analyses. Heart dosimetric parameters were correlated with the risk of radiation pneumonitis (RP) using UVA and MVA. RESULTS: A total of 189 patients were included with median age of 76 years (range, 48-93 years). Of these patients, 45.5% were female, 27.5% were T2, 16.9% were current smokers, 64% had preexisting cardiac risk factors, and 34.5% had CCI score of ≥ 3. Mean lung dose ± SD was 456 ± 231 cGy. Heart max, mean, and 10 cc doses were 1867 ± 1712 cGy, 265 ± 269 cGy, and 1150 ± 1075 cGy, respectively. There were 14 (7.4%) ≥ Grade 2 RP and 3 (1.6%) were ≥ Grade 3. The median overall survival was 37.3 months (95% confidence interval, 29.8-45.3 months). On UVA, female gender (P < .01), higher Eastern Cooperative Oncology Group (P = .01), cardiac risk (P < .01), CCI (P < .01), and bilateral ventricles max dose (P = .02) were associated with non-cancer-related deaths; on MVA, bilateral ventricles max dose was significant (P = .05). No heart parameters were associated with RP. CONCLUSIONS: Higher bilateral ventricles max dose is associated with poorer survival. Heart dose parameters should be considered when planning patients for SBRT.

Evaluating the Effectiveness of an Electronic Learning Tool for Volumetric Imaging Training-Perceptions of Radiation Therapy Professionals.

PURPOSE: Daily volumetric imaging through cone-beam computed tomography (CBCT) has greatly impacted the roles and responsibilities of radiation therapists (RTTs). A CBCT eLearning module was developed at our cancer centre to equip RTTs with critical thinking skills and clinical judgement required in a CBCT guidance environment. This study aims to evaluate the effectiveness of the electronic module and its impact on the learner's outcome from the perspectives of various radiation therapy professions and to assess the applicability of the eLearning module to RTTs, oncologists, and physicists. METHODS AND MATERIALS: The module "Myths in Cone-Beam Computed Tomography Practice" was evaluated by participants from our in-house accelerated education program. A 21-item questionnaire was developed to assess the module effectiveness. Two cohorts of attendees from the in-house accelerated education program (19 oncologists, 14 physicists, 14 therapists) were asked to voluntarily complete the survey following review of the module. Data analyses were performed between groups to determine differences in their perceptions. RESULTS: Twenty-one participants (5 oncologists, 3 physicists, 13 therapists) responded to the survey yielding a response rate of 44.68%. Survey responses indicate learners found the format user friendly, clear, and easy to navigate. All participants agreed that the electronic format of this module is conducive to learning with 60% agreement that this module is more useful than live sessions; 94.74% agreed that the module increases confidence in practicing image-guided radiation therapy. CONCLUSIONS: This module is a useful resource for all disciplines of radiation medicine. While the electronic format of this module may be useful worldwide in centres requiring training of their employees in volumetric image-guided radiation therapy, live interactive sessions should supplement this training.

ω-3 fatty acids suppress inflammatory cytokine production by macrophages and hepatocytes.

OBJECTIVE: Long-term total parenteral nutrition (TPN) in children is often complicated by parental nutrition-associated liver disease and may even lead to liver failure. Recently, the addition of ω-3 fatty acids to TPN has been shown to reduce the risk of parental nutrition-associated liver disease. The purpose of this study was to explore the anti-inflammatory effects of ω-3 fatty acids (eicosapentaenoic acid [EPA]) to demonstrate the protection of the liver against hepatic steatosis and damage. MATERIALS AND METHODS: Lipopolysaccharide (LPS) and prostaglandin E(2) (PGE(2)) were used to stimulate human macrophages and hepatocytes (THLE-3) to induce in vitro inflammatory condition. The cells were then incubated with either ω-3 (EPA) or ω-6 (arachidonic acid) fatty acids. Supernatants were collected at different time points for the measurement of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 10 (IL-10) using enzyme-linked immunosorbent assay. Furthermore, pretreated macrophages by LPS stimulation and after incubation with EPA were added to prestimulated hepatocytes for the subsequent measurement of cytokine response. RESULTS: Eicosapentaenoic acid effectively reduced LPS-induced or PGE(2)-induced TNF-α and IL-6 expression, and increased IL-10 expression significantly when compared with arachidonic acid. Furthermore, supernatant collected after co-culturing EPA with macrophages also suppressed the levels of TNF-α and IL-6 in hepatocytes. This would suggest that EPA not only had an anti-inflammatory effect on macrophages and hepatocytes directly, it could indirectly reduce hepatocyte inflammation through activated macrophages. CONCLUSIONS: The addition of ω-3 fatty acids in TPN suppresses the inflammatory response via direct and indirect routes. The findings may help explain the clinical benefits of EPA in pediatric patients receiving long-term TPN.