Barrier films or dressings for the prevention of acute radiation dermatitis in breast cancer: a systematic review and network meta-analysis.

BACKGROUND: Barrier films or dressings were reported to be effective in preventing radiation dermatitis (RD) in breast cancer patients, but their comparative efficacy is unknown. METHODS: A systematic literature search was performed on Embase, MEDLINE and Cochrane CENTRAL Registry of Clinical Trials from inception to October 20, 2023. Randomised controlled trials (RCTs) comparing barrier films or dressings to the standard of care (SOC) or other interventions were included. We estimated summary odds ratios and mean differences using network meta-analysis with random effects. This study was registered with PROSPERO (ID: CRD42023475021). RESULTS: Fourteen RCTs met inclusion criteria. Six interventions were analysed: 3M™ Moisturizing Double Barrier Cream (MDBC), 3M™ No Sting Barrier Film (BF), Hydrofilm® (HF), Mepitel® Film (MF), Silver Leaf Nylon Dressing and StrataXRT®. HF, MF and StrataXRT® reduced the incidence of moist desquamation compared to SOC (HF: OR = 0.08; p = 0.02; MF: OR = 0.31 p < 0.01; StrataXRT®: OR = 0.22, p = 0.04). The ranking of agents from most to least effective in preventing moist desquamation according to P-scores was HF (92.5%), MF (78.5%), StrataXRT® (70.1%), BF (46.4%), Silver Leaf Nylon Dressing (24.9%), MDBC (22.9%) and SOC (14.7%). Only four RCTs on HF and MF included patient-reported outcome (PRO) assessments that allowed pooling for analysis. HF and MF were more effective in reducing pain, itchiness and burning sensation compared to SOC (p < 0.01 for all symptoms). CONCLUSION: HF and MF were effective in preventing RD in breast cancer. Future RCTs should compare these interventions to effective cream preparations, such as topical corticosteroids.

Mepitel film for the prevention of radiation dermatitis: A comprehensive review of its efficacy, side effects, physics measurements, patient- and clinician-reported outcomes.

Objective: This review aimed to summarize the benefits, side effects, physics measurements, and patient- and clinician-reported outcomes of Mepitel film (MF) in preventing radiation dermatitis (RD) for cancer patients. Methods: The online database PubMed was searched from inception to April 15, 2024 with the search terms "Mepitel film" or "Mepitel." Articles of any study design evaluating MF for the prevention of RD were included. Non-human studies were excluded. Results: The database search identified 119 articles and 13 of them were included in this review. Across these studies, MF was found to be beneficial in reducing RD and improved patient- and clinician-reported outcomes in breast and head and neck cancers. Side effects of MF included itchiness, acne, allergic reaction, tightness, discomfort, and poor film adherence, but patient dropouts were uncommon. MF did not cause a bolus effect or increased skin dose in physics measurements. Conclusions: MF is a safe and effective intervention for preventing acute RD. It should be recommended in breast cancer patients where the data is more robust. Further research is needed to evaluate MF's efficacy on patients with different skin tones, its cost-effectiveness, and identifying patients who most benefit from MF relative to other effective interventions.

Residual OXPHOS is required to drive primary and metastatic lung tumours in an orthotopic breast cancer model.

Background: Fast adaptation of glycolytic and mitochondrial energy pathways to changes in the tumour microenvironment is a hallmark of cancer. Purely glycolytic ρ0 tumour cells do not form primary tumours unless they acquire healthy mitochondria from their micro-environment. Here we explored the effects of severely compromised respiration on the metastatic capability of 4T1 mouse breast cancer cells. Methods: 4T1 cell lines with different levels of respiratory capacity were generated; the Seahorse extracellular flux analyser was used to evaluate oxygen consumption rates, fluorescent confocal microscopy to assess the number of SYBR gold-stained mitochondrial DNA nucleoids, and the presence of the ATP5B protein in the cytoplasm and fluorescent in situ nuclear hybridization was used to establish ploidy. MinION nanopore RNA sequence analysis was used to compare mitochondrial DNA transcription between cell lines. Orthotopic injection was used to determine the ability of cells to metastasize to the lungs of female Balb/c mice. Results: OXPHOS-deficient ATP5B-KO3.1 cells did not generate primary tumours. Severely OXPHOS compromised ρ0D5 cells generated both primary tumours and lung metastases. Cells generated from lung metastasis of both OXPHOS-competent and OXPHOS-compromised cells formed primary tumours but no metastases when re-injected into mice. OXPHOS-compromised cells significantly increased their mtDNA content, but this did not result in increased OXPHOS capacity, which was not due to decreased mtDNA transcription. Gene set enrichment analysis suggests that certain cells derived from lung metastases downregulate their epithelial-to-mesenchymal related pathways. Conclusion: In summary, OXPHOS is required for tumorigenesis in this orthotopic mouse breast cancer model but even very low levels of OXPHOS are sufficient to generate both primary tumours and lung metastases.

Patient-reported experience with the use of Mepitel Film for prevention of acute radiation dermatitis in breast cancer.

BACKGROUND AND PURPOSE: Mepitel Film (MF) has been demonstrated to reduce the severity of radiation dermatitis (RD) in patients receiving breast cancer radiotherapy (RT). The objective of this study was to characterize patient-reported experience with MF use, including its impact on daily activities and wellbeing. MATERIALS AND METHODS: This single-institution study analyzed anonymized responses to a questionnaire completed by patients who used MF for the prevention of RD during breast cancer RT. RESULTS: Of the 254 patients contacted, 192 patients completed the survey. Most patients disagreed or strongly disagreed that MF limited their ability to perform their daily activities, including household chores (88%, n = 169/191), their ability to work (83%, n = 157/189), or their ability to sleep (85%, n = 163/191). Furthermore, patients agreed or strongly agreed MF was comfortable on their skin (67%, n = 126/189) and protected their skin from rubbing against clothing (86%, n = 161/188). Some patients agreed or strongly agreed that MF affected their ability to shower (31%, n = 50/162), wear bras (28%, n = 51/185), and impacted their level of pruritus (35%, n = 67/189). However, most patients agreed or strongly agreed that their overall experience with MF was positive (92%, n = 173/189) and would recommend MF to a friend undergoing breast cancer RT (88%, n = 166/188). CONCLUSION: MF use is associated with positive patient-reported experience during breast RT with minimal impact on daily activities.

StrataXRT for the prevention and treatment of radiation dermatitis: a critical review.

PURPOSE: The primary objective is to systematically review primary studies, such as randomized control trials (RCTs), feasibility, exploratory, and case studies; and the secondary objective is to evaluate all secondary articles, such as reviews, guidelines, and editorials, relevant to the use of StrataXRT for the prevention and/or management of radiation dermatitis (RD) in cancer patients. METHODS: A literature search was conducted up to February 26, 2023, for articles investigating the use of StrataXRT for the prevention and treatment of RD, in the following databases: Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar. The keywords "StrataXRT", "dermatitis", "radiotherapy", and "radiation" were used to identify relevant articles. RESULTS: Twenty-seven articles from 2018 to 2022 were identified to fulfill the inclusion criteria of this review, of which nine are primary studies and 18 are secondary papers. Significant heterogeneity was observed in the current literature studying the effects of StrataXRT, making it difficult to make cross-trial comparisons. There is a suggestion of the efficacy of StrataXRT in the prevention and treatment of RD. CONCLUSION: The findings of this review recommend further adequately powered RCTs with robust methodology including patient and clinician assessments to determine the efficacy of StrataXRT in preventing and treating RD. This is essential to improve the quality of life of patients and identify which groups of patients would benefit most from StrataXRT.

Perceptions of healthcare professionals on the use of Mepitel Film for the prevention of acute radiation dermatitis in breast cancer.

INTRODUCTION: Randomized clinical trials support Mepitel Film (MF) as a prophylactic treatment for radiation dermatitis (RD) in patients undergoing breast radiotherapy. Although several studies have canvassed the opinion of patients on using MF, no such studies have been done to investigate the perception of healthcare professionals (HCPs). The objective of this study was therefore to investigate the perceptions of HCPs on MF as a treatment option for RD. METHODS: Anonymized responses to a web-based survey sent to HCPs at a single institution managing patients using MF during breast radiotherapy were analyzed. RESULTS: Of the 28 HCPs contacted, 22 completed the survey, including 6 radiation oncologists (ROs), 11 radiation therapists (RTTs), and 5 nurses. Most HCPs reported MF was better at preventing severe RD than the standard of care and improved radiation-induced skin reactions (n = 20/22, 91%, and n = 19/22, 86%, respectively). MF was recommended for mastectomy patients without reconstruction (n = 15/21, 71%). The majority of HCPs believed that patients' families could be trained to apply and remove MF (n = 19/22, 86%). Many HCPs perceived that implementation of MF would be difficult in terms of maintaining patient flow and wide-scale implementation within their institution (n = 11/22, 50%, and n = 10/22, 46%, respectively). Most HCPs perceived that fewer than 50% of their patients could afford MF if priced at $100 CAD (n = 15/20, 75%). CONCLUSION: These findings provide insights into the possibility of MF to be incorporated into standard practice of care for RD. Although most HCPs were satisfied with MF as a prophylactic treatment for RD, there are concerns about its resource-intensive operationalization and financial accessibility to patients. Future research should focus on ways to improve HCP experience with MF and to improve its implementation into clinical settings as standard of care.

Polyphenol and glucosinolate-derived AhR modulators regulate GPR15 expression on human CD4+ T cells.

Diets high in fruit and vegetables are perceived to be beneficial for intestinal homeostasis, in health as well as in the context of inflammatory bowel diseases (IBDs). Recent breakthroughs in the field of immunology have highlighted the importance of the ligand-activated transcription factor aryl hydrocarbon receptor (AhR) as a critical regulator of mucosal immunity, including the intestinal trafficking of CD4+ helper T cells, an immune cell subset implicated in a wide range of homeostatic and pathogenic processes. Specifically, the AhR has been shown to directly regulate the expression of the chemoattractant receptor G Protein-Coupled Receptor 15 (GPR15) on CD4+ T cells. GPR15 is an important gut homing marker whose expression on CD4+ T cells in the peripheral circulation is elevated in patients suffering from ulcerative colitis, raising the possibility that, in this setting, the beneficial effect of a diet rich in fruits and vegetables may be mediated through the modulation of GPR15 expression. To address this, we screened physiologically-relevant polyphenol and glucosinolate metabolites for their ability to affect both AhR activity and GPR15 expression. Our complementary approach and associated findings suggest that polyphenol and glucosinolate metabolites can regulate GPR15 expression on human CD4+ T cells in an AhR-dependent manner.

Mepitel film for the prevention and treatment of acute radiation dermatitis in breast cancer: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: This systematic review and meta-analysis aimed to evaluate the efficacy of Mepitel film in preventing or treating acute radiation dermatitis (RD) in patients with breast cancer in randomized controlled trials (RCTs). METHODS: Embase, APA PsychInfo, Journals@Ovid Full Text, Ovid MEDLINE, PubMed, and Cochrane Trials were searched until December 12, 2022, to identify RCTs on the use of Mepitel film for preventing or treating acute RD from breast cancer radiotherapy. Per-protocol analysis was used to compare outcomes, calculate pooled effect sizes, odds ratio (OR), and 95% confidence intervals (CI), and to create forest plots using random effects analysis in RevMan 5.4. RESULTS: Three RCTs were included in this review. Mepitel film significantly reduced the incidence of grade 3 RD (OR 0.15 95% CI 0.06, 0.37, p<0.0001) and grade 2 or 3 RD (OR 0.16 95% CI 0.04, 0.65, p=0.01) as scored on either the CTCAE or the RTOG scale. Additionally, Mepitel film significantly reduced RISRAS mean scores assessed by patients and combined researcher and patient (standardized mean difference (SMD) -7.59, 95% CI -14.42, -0.76, p=0.03; SMD -15.36, 95% CI -30.01, -0.71 p=0.04) but not the researcher component of the assessment tool (SMD -17.55, 95% CI -36.94, 1.84, p=0.08). CONCLUSION: Mepitel film reduced the incidence of acute RD and improved patient-reported outcomes with minimal side effects, the main one being itchiness. Future research should assess the feasibility of Mepitel film with respect to specific patient-reported outcomes such as health-related quality of life issues associated with its use.

Mepitel Film for the prevention of acute radiation dermatitis in head and neck cancer: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: This systematic review and meta-analysis evaluates the efficacy of Mepitel Film in preventing acute radiation dermatitis (RD) in patients with head and neck cancer (HNC) across randomized controlled trials (RCTs). METHODS: Embase, MEDLINE, and Cochrane Central Register of Controlled Trials were searched on 5 March 2023 to identify relevant RCTs. RD assessment tools and outcomes were compared across studies. Pooled effect sizes and 95% confidence intervals (CI) were estimated based on random-effects analysis using RevMan 5.4. RESULTS: Three RCTs conducted between 2018 and 2020 were included. Mepitel Film decreased RD severity when compared to Sorbolene or Biafine but not when compared to mometasone. A per-protocol analysis of two of the trials revealed that, overall, Mepitel Film significantly reduced the incidence of grade 2-3 RD (odds ratio (OR), 0.24; 95% CI, 0.09-0.65; p = 0.005) and moist desquamation (OR, 0.21; 95% CI, 0.10-0.46; p < 0.0001) and decreased average patient, researcher, and combined components of the Radiation-Induced Skin Reaction Assessment Scale (the standardized mean difference (SMD) for patient ratings, - 2.56; 95% CI, - 3.15 to - 1.96, p < 0.00001; SMD for researcher ratings, - 3.47; 95% CI, - 6.63 to - 0.31, p = 0.03; SMD for combined scores, - 3.68; 95% CI, - 6.43 to - 0.92, p = 0.009). Noted issues with Mepitel Film included itchiness and poor adherence. CONCLUSION: While there were discrepancies across studies, Mepitel Film demonstrated a decrease in the incidence of grade 2-3 RD and moist desquamation. These findings emphasize the need for further examining Mepitel Film's efficacy across diverse patient groups and the importance of standardizing RD severity assessment methodologies and control arms.

Bioenergetic and Metabolic Adaptation in Tumor Progression and Metastasis.

The ability of cancer cells to adjust their metabolism in response to environmental changes is a well-recognized hallmark of cancer. Diverse cancer and non-cancer cells within tumors compete for metabolic resources. Metabolic demands change frequently during tumor initiation, progression and metastasis, challenging our quest to better understand tumor biology and develop novel therapeutics. Vascularization, physical constraints, immune responses and genetic instability promote tumor evolution resulting in immune evasion, opportunities to breach basement membrane barriers and spread through the circulation and lymphatics. In addition, the unfolded protein response linked to the ubiquitin proteasome system is a key player in addressing stoichiometric imbalances between nuclear and mitochondrially-encoded protein subunits of respiratory complexes, and nuclear-encoded mitochondrial ribosomal protein subunits. While progressive genetic changes, some of which affect metabolic adaptability, contribute to tumorigenesis and metastasis through clonal expansion, epigenetic changes are also important and more dynamic in nature. Understanding the role of stromal and immune cells in the tumor microenvironment in remodeling cancer cell energy metabolism has become an increasingly important area of research. In this perspective, we discuss the adaptations made by cancer cells to balance mitochondrial and glycolytic energy metabolism. We discuss how hypoxia and nutrient limitations affect reductive and oxidative stress through changes in mitochondrial electron transport activity. We propose that integrated responses to cellular stress in cancer cells are central to metabolic flexibility in general and bioenergetic adaptability in particular and are paramount in tumor progression and metastasis.

Review of the Accident Compensation Corporation's radiation therapy injury claims, 1 July 2009-30 June 2019.

AIM: The aim of this study was to review and report on radiation therapy injury claims lodged with the Accident Compensation Corporation (ACC) in New Zealand in the last decade. METHODS: ACC's treatment injury database was used to identify injury claims decided between 1 July 2009 and 30 June 2019. The associated structured and unstructured data, including claim lodgement information and medical records, were reviewed. RESULTS: Of 121,168 treatment injuries, only 975 (0.8%) were radiation therapy injury claims, with 519 claims accepted for cover. Most declined claims were considered "ordinary consequences of treatment" rather than treatment injuries. Of the 519 accepted claims, ACC classified 21 as fatal and eight as serious, which indicates a need for lifelong ACC support. Injuries correlated with the age and gender of the most common cancers treated with radiation therapy in New Zealand. More treatment injury claims were submitted and accepted for New Zealand European patients compared with Maori and Pasifika patients. CONCLUSION: Radiation therapy injury claims make up a very small proportion of the total number of ACC treatment injury claims. A better understanding of the claim process may assist injured individuals better by improving appropriate claim lodgement and claim acceptance rates.

Practical Approach To Explore the Effects of Polyphenols on Aryl Hydrocarbon Receptor Regulated Immune Function.

The ligand-activated aryl hydrocarbon receptor (AhR) is an important molecular regulator of immune function, whose activity can be modulated by dietary glucosinolate- and tryptophan-derived metabolites. In contrast, the potential use of polyphenols as dietary regulators of AhR-dependent immunity remains unclear. In this perspective, we discuss how cellular metabolism may alter the net effect of polyphenols on AhR, thus potentially reconciling some of the conflicting observations reported in the literature. We further provide a methodological roadmap, across the fields of immunology, metabolomics, and gut microbial ecology, to explore the potential effects of polyphenol-rich diets on AhR-regulated immune function in humans.

A simple indirect colorimetric assay for measuring mitochondrial energy metabolism based on uncoupling sensitivity.

PURPOSE: Cancer cells rapidly adjust their balance between glycolytic and mitochondrial ATP production in response to changes in their microenvironment and to treatments like radiation and chemotherapy. Reliable, simple, high throughput assays that measure the levels of mitochondrial energy metabolism in cells are useful determinants of treatment effects. Mitochondrial metabolism is routinely determined by measuring the rate of oxygen consumption (OCR). We have previously shown that indirect inhibition of plasma membrane electron transport (PMET) by the mitochondrial uncoupler, FCCP, may also be a reliable measure of mitochondrial energy metabolism. Here, we aimed to validate these earlier findings by exploring the relationship between stimulation of oxygen consumption by FCCP and inhibition of PMET. METHODS: We measured PMET by reduction of the cell impermeable tetrazolium salt WST-1/PMS. We characterised the effect of different growth conditions on the extent of PMET inhibition by FCCP. Next, we compared FCCP-mediated PMET inhibition with FCCP-mediated stimulation of OCR using the Seahorse XF96e flux analyser, in a panel of cancer cell lines. RESULTS: We found a strong inverse correlation between stimulation of OCR and PMET inhibition by FCCP. PMET and OCR were much more severely affected by FCCP in cells that rely on mitochondrial energy production than in cells with a more glycolytic phenotype. CONCLUSION: Indirect inhibition of PMET by FCCP is a reliable, simple and inexpensive high throughput assay to determine the level of mitochondrial energy metabolism in cancer cells.

Mitochondrial DNA Affects the Expression of Nuclear Genes Involved in Immune and Stress Responses in a Breast Cancer Model.

Tumor cells without mitochondrial (mt) DNA (ρ0 cells) are auxotrophic for uridine, and their growth is supported by pyruvate. While ATP synthesis in ρ0 cells relies on glycolysis, they fail to form tumors unless they acquire mitochondria from stromal cells. Mitochondrial acquisition restores respiration that is essential for de novo pyrimidine biosynthesis and for mitochondrial ATP production. The physiological processes that underpin intercellular mitochondrial transfer to tumor cells lacking mtDNA and the metabolic remodeling and restored tumorigenic properties of cells that acquire mitochondria are not well understood. Here, we investigated the changes in mitochondrial and nuclear gene expression that accompany mtDNA deletion and acquisition in metastatic murine 4T1 breast cancer cells. Loss of mitochondrial gene expression in 4T1ρ0 cells was restored in cells recovered from subcutaneous tumors that grew from 4T1ρ0 cells following acquisition of mtDNA from host cells. In contrast, the expression of most nuclear genes that encode respiratory complex subunits and mitochondrial ribosomal subunits was not greatly affected by loss of mtDNA, indicating ineffective mitochondria-to-nucleus communication systems for these nuclear genes. Further, analysis of nuclear genes whose expression was compromised in 4T1ρ0 cells showed that immune- and stress-related genes were the most highly differentially expressed, representing over 70% of those with greater than 16-fold higher expression in 4T1 compared with 4T1ρ0 cells. The monocyte recruiting chemokine, Ccl2, and Psmb8, a subunit of the immunoproteasome that generates MHCI-binding peptides, were the most highly differentially expressed. Early monocyte/macrophage recruitment into the tumor mass was compromised in 4T1ρ0 cells but recovered before mtDNA could be detected. Taken together, our results show that mitochondrial acquisition by tumor cells without mtDNA results in bioenergetic remodeling and re-expression of genes involved in immune function and stress adaptation.

Mepitel Film is superior to Biafine cream in managing acute radiation-induced skin reactions in head and neck cancer patients: a randomised intra-patient controlled clinical trial.

INTRODUCTION: We previously showed that Mepitel Film decreased the severity of acute radiation-induced skin reactions in head and neck cancer patients. In the current study, we compared the effect of Mepitel Film and Biafine cream on skin reaction severity in a larger cohort of head and neck cancer patients. METHODS: A total of 44 head and neck cancer patients were recruited with 39 patients contributing full data sets for analysis. Patients received a dose of 50 Gy in 25 fractions to the bilateral lymph nodes in the neck. Left and right lymph node areas were randomised to either Mepitel Film or Biafine cream, applied prophylactically. Skin reaction severity was measured using Radiation-Induced Skin Reaction Assessment Scale (RISRAS) and expanded Radiation Oncology group (RTOG) grades. Skin dose was measured using gafchromic Film. RESULTS: Skin reaction severity (combined RISRAS score) underneath Mepitel Film was decreased by 30% (P < 0.001) and moist desquamation rates by 41% (P < 0.001). Skin dose underneath Mepitel Film and Biafine cream was similar (P = 0.925) and unlikely to have affected skin reaction severity. The vast majority (80%) of patients preferred Mepitel Film over Biafine cream. Negative aspects of Mepitel Film included poor adherence (11/39) and discomfort (16/39) during hot weather and showering and itchy skin underneath Mepitel Film (12/39). CONCLUSIONS: Mepitel Film was superior to Biafine cream in reducing the severity of acute radiation-induced skin reactions and moist desquamation incidence in our head and neck patient cohort.

Cranberry capsules are not superior to placebo capsules in managing acute non-haemorrhagic radiation cystitis in prostate cancer patients: A phase III double blinded randomised placebo controlled clinical trial.

PURPOSE: Acute radiation cystitis affects the quality of life of many prostate cancer patients. A previous pilot study suggested that cranberry capsules may decrease some of the symptoms of acute radiation cystitis. Here we further test their effectiveness in a multicentre double blinded placebo-controlled clinical trial. MATERIAL AND METHODS: A total of 108 prostate cancer patients were recruited at three New Zealand hospitals between September 2016 and January 2019. Out of this cohort, 101 patients provided datasets for analysis (51 men on cranberry capsules and 50 men on beetroot-containing placebo capsules). Patients took two capsules each morning during RT and for 2 weeks after completion of RT. Three measures were used to assess cystitis severity: modified RTOG, O'Leary interstitial cystitis scale and a sensitive novel radiation induced cystitis assessment scale (RICAS). Cystitis severity was scored at baseline and weekly thereafter during RT and for two weeks after completion of RT. Radiation protocols were stratified to conventional fractionation or hypo-fractionated radiation therapy (CHHiP) to the prostate or radiation to the prostate bed. RESULTS: Cranberry capsules performed significantly worse than placebo capsules with respect to day time frequency and bladder control, using the more sensitive RICAS scale. No significant difference in cystitis severity was seen between patients receiving hypofractionation and those receiving conventional fractionation to the prostate gland. CONCLUSION: Cranberry capsules were not superior to beetroot-containing placebo capsules in managing radiation cystitis in our prostate patient cohort. RICAS may be a useful tool for measuring radiation cystitis in future studies.

Mepitel Film and Mepilex Lite for the prophylaxis and treatment of skin toxicities from breast radiation.

Despite the prevalence of radiation dermatitis in breast cancer patients, current practice guidelines for its treatment are limited. We aimed to discuss the quality of evidence for the barrier-forming Mepitel Film for prophylaxis of radiation dermatitis, and argue for further investigation into evidence-based management of skin toxicities. Two studies assessing Mepitel Film were critically evaluated. Both reported that Mepitel Film decreased radiation dermatitis; moreover, patient-reported outcomes significantly favoured Mepitel Film. However, there has not been global adoption of barrier-forming films such as Mepitel, in part due to the absence of multi-centred randomised trials and the heterogeneity of study designs.

Intercellular Communication in Tumor Biology: A Role for Mitochondrial Transfer.

Intercellular communication between cancer cells and other cells in the tumor microenvironment plays a defining role in tumor development. Tumors contain infiltrates of stromal cells and immune cells that can either promote or inhibit tumor growth, depending on the cytokine/chemokine milieu of the tumor microenvironment and their effect on cell activation status. Recent research has shown that stromal cells can also affect tumor growth through the donation of mitochondria to respiration-deficient tumor cells, restoring normal respiration. Nuclear and mitochondrial DNA mutations affecting mitochondrial respiration lead to some level of respiratory incompetence, forcing cells to generate more energy by glycolysis. Highly glycolytic cancer cells tend to be very aggressive and invasive with poor patient prognosis. However, purely glycolytic cancer cells devoid of mitochondrial DNA cannot form tumors unless they acquire mitochondrial DNA from adjacent cells. This perspective article will address this apparent conundrum of highly glycolytic cells and cover aspects of intercellular communication between tumor cells and cells of the microenvironment with particular emphasis on intercellular mitochondrial transfer.

VERT, a virtual clinical environment, enhances understanding of radiation therapy planning concepts.

INTRODUCTION: The ability to understand treatment plan dosimetry and apply this understanding clinically is fundamental to the role of the radiation therapist. This study evaluates whether or not the Virtual Environment for Radiotherapy Training (VERT) contributes to teaching treatment planning concepts to a cohort of first-year radiation therapy students. METHODS: We directly compared a custom-developed VERT teaching module with a standard teaching module with respect to the understanding of treatment planning concepts using a cross-over design. Students self-reported their understanding of specific concepts before and after delivery of the VERT and standard teaching modules and evaluated aspects of VERT as a learning experience. In addition, teaching staff participated in a semi-structured interview discussing the modules from an educational perspective. RESULTS: Both the standard teaching module and VERT teaching module enhanced conceptual understanding and level of confidence in the student cohort after both teaching periods. The proportion of students reporting a perceived increase in knowledge/confidence was similar for the VERT teaching module for all but two scenarios. We propose that an integrated approach, providing a strong theoretical conceptual framework, followed by VERT to situate this framework in the (simulated) clinical environment combines the best of both teaching approaches. CONCLUSION: This study has established for the first time a clear role for a tailored VERT teaching module in teaching RT planning concepts because of its ability to visualise conceptual information within a simulated clinical environment.

Review of the patient positioning reproducibility in head-and-neck radiotherapy using Statistical Process Control.

BACKGROUND AND PURPOSE: A remarkable improvement in patient positioning was observed after the implementation of various process changes aiming to increase the consistency of patient positioning throughout the radiotherapy treatment chain. However, no tool was available to describe these changes over time in a standardised way. This study reports on the feasibility of Statistical Process Control (SPC) to highlight changes in patient positioning accuracy and facilitate correlation of these changes with the underlying process changes. MATERIALS AND METHODS: Metrics were designed to quantify the systematic and random patient deformation as input for the SPC charts. These metrics were based on data obtained from multiple local ROI matches for 191 patients who were treated for head-and-neck cancer during the period 2011-2016. RESULTS: SPC highlighted a significant improvement in patient positioning that coincided with multiple intentional process changes. The observed improvements could be described as a combination of a reduction in outliers and a systematic improvement in the patient positioning accuracy of all patients. CONCLUSION: SPC is able to track changes in the reproducibility of patient positioning in head-and-neck radiation oncology, and distinguish between systematic and random process changes. Identification of process changes underlying these trends requires additional statistical analysis and seems only possible when the changes do not overlap in time.