Technological Advances In Radiotherapy Research Articles

Recent Technological Advances in Radiotherapy

Recent Technological Advances in Radiotherapy

Radiation-induced skin reactions: mechanism and treatment.

Radiotherapy (RT) is a major treatment for malignant tumors. The latest data show that >70% of patients with malignant tumors need RT at different periods. Skin changes can be experienced by up to 95% of patients who underwent RT. Inflammation and oxidative stress (OS) have been shown to be generally associated with radiation-induced skin reactions (RISRs). Inflammatory response and OS interact and promote each other during RISRs. Severe skin reactions often have a great impact on the progress of RT. The treatment of RISRs is particularly critical because advanced RT technology can also lead to skin reactions. RISRs are classified into acute and chronic reactions. The treatment methods for acute RISRs include steroid treatment, creams, ointments, and hydrocolloid dressings, depending on the reaction grading. Chronic RISRs includes chronic ulcerations, telangiectasias, and fibrosis of the skin, and advanced treatments such as mesenchymal stem cells, hyperbaric oxygen therapy, superoxide dismutase, and low-intensity laser therapy can be considered. Here, we review and summarize the important mechanisms that cause RISRs as well as the standard and advanced treatments for RISRs.

Predictors of Radiation Esophagitis in Locally Advanced Non-Small Cell Lung Cancer with Modern Radiation Therapy Planning

Radiation esophagitis (RE) is major side effect of concurrent chemoradiation (cCRT) for locally advanced non-small cell lung cancer (NSCLC). Advances in radiation technology allow for better esophageal sparing, potentially affording opportunities to reduce RE without compromising outcomes. Existing studies on RE largely do not include patients treated using intensity modulated radiation therapy (IMRT). In this study, we aimed to determine RE frequency and predictors with modern radiation planning. We retrospectively analyzed 594 NSCLC patients treated with definitive intent with cCRT using 3D-conformal RT (3D-CRT) or IMRT at one institution from 2001-2014. A mean esophageal dose constraint of 34 Gy was used in most cases. RE events were graded with the Radiation Therapy Oncology Group (RTOG) system. Predictors of RTOG grade ≥3 RE were analyzed with multivariable logistic regression using backward selection. Overall survival (OS) and progression free survival (PFS) were calculated with the Kaplan-Meier method. Median follow-up was 22.8 months (mo), median OS was 25.2 mo, and median PFS was 10.8 mo. Median age was 65.2 years and 49.8% of patients were male. At presentation, 8.4% were Stage II, 55.9% Stage IIIA, and 35.7% Stage IIIB. Adenocarcinoma made up 46.0% of cases, squamous cell carcinoma 30.0%, and NSCLC-NOS 24.1%. 3D-CRT was used in 75.1% of cases, and IMRT in 24.9%. Median prescribed dose was 66 Gy (range, 36-74 Gy) and median dose per fraction was 2 Gy (range, 1.8-3 Gy). Median maximum and mean esophageal doses were 64.7 Gy (range, 0.9-78.8 Gy) and 24.0 Gy (range, 0.4-56.8 Gy), respectively. Mean esophageal dose was >34 Gy in 95 (16.0%) of patients. Median esophageal V45, V55, and V60 were 28.7% (range, 0-82.7%), 17.0% (range, 0-73.7%), and 8.4% (range, 0-66.8%), respectively, and these values were higher in patients treated with IMRT (Table 1). Grade ≥3 RE was observed in 113 (19%) patients. On multivariable analysis, NSCLC-NOS histology (OR 2.08, 95% CI 1.23-3.53, p=0.006), IMRT (OR 0.36, 95% CI 0.20-0.63, p<0.001), and mean esophageal dose per Gy (OR 1.10, 95% CI 1.07-1.13, p<0.001) were associated with grade ≥3 RE.Abstract TU_26_3574; Table 13D-CRT and IMRT dose-volume metrics3D-CRT (n=446)IMRT (n=148)p-valuePrescribed dose, Gy (median, range)66 (36-74)66 (40-72)0.65Maximum esophageal dose, Gy63.2 (0.9-78.8)66.9 (7.5-77.5)0.0001Mean esophageal dose, Gy22.7 (0.4-56.8)27.5 (1.6-55.4)<0.0001Esophageal V45, %28.1 (0-77.8)33.2 (0-82.7)0.0002Esophageal V55, %16.0 (0-71.2)21.0 (0-73.7)0.0005Esophageal V60, %5.8 (0-66.8)16.0 (0-66.6)0.0003 Open table in a new tab Mean esophageal dose was the strongest dosimetric predictor of grade ≥3 RE. Even after controlling for higher mean esophageal dose, IMRT was associated with lower RE risk. This suggests that different dose-volume constraints may be important in 3D-CRT and IMRT plans.

간세포암종에서의 체부정위방사선치료

With recent remarkable technological advances in radiation therapy, stereotactic body radiation therapy (SBRT) is regarded as an alternative treatment option for hepatocellular carcinoma (HCC) that is not suitable for curative treatment. Several prospective and retrospective studies on the use of SBRT in patients with HCC showed promising results. Furthermore, on-going prospective studies are examining the role of SBRT as a single ablative modality or a combination treatment in patients with HCC. Here, we summarize previous studies and recent updates and discuss the future perspectives of SBRT for HCC.

Advanced radiation techniques for locally advanced non-small cell lung cancer: intensity-modulated radiation therapy and proton therapy.

Radiation therapy (RT) represents an integral part of a multimodality treatment plan in the definitive, preoperative and postoperative management of non-small cell lung cancer (NSCLC). Technological advances in RT have enabled a shift from two-dimensional radiotherapy to more conformal techniques. Three-dimensional conformal radiotherapy (3DCRT), the current minimum technological standard for treating NSCLC, allows for more accurate delineation of tumor burden by using computed tomography-based treatment planning instead of two-dimensional radiographs. Intensity-modulated RT (IMRT) and proton therapy represent advancements over 3DCRT that aim to improve the conformity of RT and provide the possibility for dose escalation to the tumor by minimizing radiation dose to organs at risk. Both techniques likely confer benefits to certain anatomic subgroups of NSCLC requiring RT. This article reviews pertinent studies evaluating the use of IMRT and proton therapy in locally advanced NSCLC, and outlines challenges, indications for use, and areas for future research.

Advances in the use of motion management and image guidance in radiation therapy treatment for lung cancer.

The development of advanced radiation technologies, including intensity-modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT) and proton therapy, has resulted in increasingly conformal radiation treatments. Recent evidence for the importance of minimizing dose to normal critical structures including the heart and lungs has led to incorporation of these advanced treatment modalities into radiation therapy (RT) for non-small cell lung cancer (NSCLC). While such technologies have allowed for improved dose delivery, implementation requires improved target accuracy with treatments, placing increasing importance on evaluating tumor motion at the time of planning and verifying tumor position at the time of treatment. In this review article, we describe issues and updates related both to motion management and image guidance in the treatment of NSCLC.

Gene expression profiling of breast cancer cell lines treated with proton and electron radiations.

Technological advances in radiation therapy are evolving with the use of hadrons, such as protons, indicated for tumors where conventional radiotherapy does not give significant advantages or for tumors located in sensitive regions, which need the maximum of dose-saving of the surrounding healthy tissues. The genomic response to conventional and non-conventional linear energy transfer exposure is a poor investigated topic and became an issue of radiobiological interest. The aim of this work was to analyze and compare molecular responses in term of gene expression profiles, induced by electron and proton irradiation in breast cancer cell lines. We studied the gene expression profiling differences by cDNA microarray activated in response to electron and proton irradiation with different linear energy transfer values, among three breast cell lines (the tumorigenic MCF7 and MDA-MB-231 and the non-tumorigenic MCF10A), exposed to the same sublethal dose of 9 Gy. Gene expression profiling pathway analyses showed the activation of different signaling and molecular networks in a cell line and radiation type-dependent manner. MCF10A and MDA-MB-231 cell lines were found to induce factors and pathways involved in the immunological process control. Here, we describe in a detailed way the gene expression profiling and pathways activated after electron and proton irradiation in breast cancer cells. Summarizing, although specific pathways are activated in a radiation type-dependent manner, each cell line activates overall similar molecular networks in response to both these two types of ionizing radiation. Advances in knowledge: In the era of personalized medicine and breast cancer target-directed intervention, we trust that this study could drive radiation therapy towards personalized treatments, evaluating possible combined treatments, based on the molecular characterization.

Chest tumors: current trends of clinical practice

This review summarizes recent updates on the role and timing of radiotherapy (RT). Multidisciplinary case discussion and careful case selection before any treatment modality can avoid morbidity and mortality. Advances in RT technology include proton treatment, respiratory gating, immobilization, forward planning, intensity-modulated radiation (IMRT), volumetric-modulated arc therapy (VMAT), tomotherapy, image-guided radiation treatment (IGRT) and on-treatment cone-beam computerized axial tomography scan (CBCT). These allow decreased doses to organ at risk such as brachial plexus, ribs, spinal cord, contralateral esophagus (CE), lung, heart, and adjacent liver. We used mesothelioma and thymoma as an example to illustrate improvements in RT techniques in past decade.

Pharmacological modulation of radiation-induced oral mucosal complications

Radiation-induced mucositis is a common toxicity, especially in patients with head and neck cancers. Despite recent technological advances in radiation therapy, such as intensity-modulated radiotherapy, radiation-induced mucositis is still causing treatment disruptions, negatively affecting patients’ long and short term quality of life, and impacting medical resources use with economic consequences. The objective of this article was to review the latest updates in the management of radiation-induced mucositis, with a focus on pharmaceutical strategies for the prevention or treatment of mucositis. Although numerous studies analysing the prevention and management of oral radiation-induced mucositis have been conducted, there are still few reliable data to guide daily clinical practice. Furthermore, most of the tested drugs have shown no (anti-inflammatory cytokine, growth factors) or limited (palifermin) effect. Therapies for acute oral mucositis are predominantly focused on improving oral hygiene and providing symptoms control. Although low-level laser therapy proved efficient in preventing radiation-induced oral mucositis in patients with head and neck cancer, this intervention requires equipment and trained medical staff, and is therefore insufficiently developed in clinical routine. New effective pharmacological agents able to prevent or reverse radio-induced mucositis are required.

Cost-containment in hypofractionated radiation therapy: a literature review.

Recent technological advances in radiation therapy have allowed for greater accuracy in planning and treatment delivery. The development of hypofractionated radiation treatment regimens is an example, and has the potential to decrease the cost per episode of care, relative to conventional treatments. Our aim was to analyse published literature on the cost‐effectiveness and budgetary implications of hypofractionated radiation therapy. As such, this article will quantify the projected health care cost savings and address the optimal means of treatment delivery, associated patient outcomes, and implications arising from an increased use of hypofractionated regimens.

Beating 'Guangdong cancer': a review and update on nasopharyngeal cancer.

Once endemic in southern China, nasopharyngeal cancer is becoming less prevalent in Hong Kong. This is probably due to a better understanding of the risk factors associated with the disease, its genomic landscape, advances in radiotherapy technology, and development of effective systemic agents. More specifically, the close relationship between Epstein-Barr virus and nasopharyngeal cancer opens up the possibility of using Epstein-Barr virus DNA as a biomarker for early detection and monitoring of the disease. On the other hand, the looming genomic data for nasopharyngeal cancer aid in the development of powerful biomarkers and promising targeted therapy. Clinical use of a combination of radiotherapy and chemotherapy continues to increase, while the development of immunotherapy, such as checkpoint inhibitors, offers hope in improving treatment outcome.

Hypo-fractionated SBRT for localized prostate cancer: a German bi-center single treatment group feasibility trial

BackgroundFor prostate cancer treatment, treatment options with minimal side effects are desired. External beam radiation therapy (EBRT) is non-invasive, standard of care and delivered in either conventional fractionation over 8 weeks or with moderate hypo-fractionation over about 5 weeks. Recent advances in radiotherapy technology have made extreme hypo-fractionated stereotactic body radiation therapy (SBRT) of prostate cancer feasible, which has not yet been introduced as a standard treatment method in Germany. Initial results from other countries are promising, but long-term results are not yet available. The aim of this study is to investigate feasibility and effectiveness of SBRT for prostate cancer in Germany.Methods/designThis German bi-center single group trial (HYPOSTAT) is designed to evaluate feasibility and effectiveness, as measured by toxicity and PSA-response, respectively, of an extreme hypo-fractionated SBRT regimen with five fractions of 7 Gy in treatment of localized low and intermediate risk prostate cancer. The target volume includes the prostate with or without the base of seminal vesicles depending on risk stratification and uncertainty margins that are kept at 3–5 mm. SBRT treatment is delivered with the robotic CyberKnife system, which was recently introduced in Germany. Acute and late toxicity after one year will be evaluated according to Common Terminology Criteria for Adverse Events (CTCAE v. 4.0), Radiation Therapy Oncology Group (RTOG) and International Prostate Symptom Score (IPSS) Scores. The quality of life will be assessed before and after treatment with the EORTC QLQ C30 questionnaire. Hypothesizing that the proportion of patients with grade 2 side effects or higher is less or equal than 2.8%, thus markedly lower than the standard EBRT percentage (17.5%), the recruitment target is 85 patients.DiscussionThe HYPOSTAT trial aims at demonstrating short term feasibility of extreme hypo-fractioned SBRT for the treatment of prostate cancer and might be used as the pilot study for a multi-center multi-platform or for randomized-controlled trials comparing conventional radiotherapy with SBRT for localized prostate cancer in the future. The study concept of patient enrollment, follow up and evaluation by multiple public university clinics and actual patient treatment in dedicated private radiosurgery practices with high-tech radiation equipment is unique for clinical trials.Study statusThe study is ongoing and currently recruiting patients.Trial registrationRegistration number: NCT02635256 (clinicaltrials.gov). Registered 8 December 2015.

Radiation hardness of dsipm sensors in a proton therapy radiation environment

In vivo verification of dose delivery in proton therapy by means of positron emission tomography (PET) or prompt gamma imaging is mostly based on fast scintillation detectors. The digital silicon photomultiplier (dSiPM) allows excellent scintillation detector timing properties and is thus being considered for such verification methods. We present here the results of the first investigation of radiation damage to dSiPM sensors in a proton therapy radiation environment. Radiation hardness experiments were performed at the AGOR cyclotron facility at the KVI-Center for Advanced Radiation Technology, University of Groningen. A 150-MeV proton beam was fully stopped in a water target. In the first experiment, bare dSiPM sensors were placed at 25 cm from the Bragg peak, perpendicular to the beam direction, a geometry typical for an in situ implementation of a PET or prompt gamma imaging device. In the second experiment, dSiPM-based PET detectors containing lutetium yttrium orthosilicate scintillator crystal arrays were placed at 2 and 4 m from the Bragg peak, perpendicular to the beam direction; resembling an in-room PET implementation. Furthermore, the experimental setup was simulated with a Geant4-based Monte Carlo code in order to determine the angular and energy distributions of the neutrons and to determine the 1-MeV equivalent neutron fluences delivered to the dSiPM sensors. A noticeable increase in dark count rate (DCR) after an irradiation with about 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> 1-MeV equivalent neutrons/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> agrees with observations by others for analog SiPMs, indicating that the radiation damage occurs in the single photon avalanche diodes and not in the electronics integrated on the sensor chip. It was found that in the in situ location, the DCR becomes too large for successful operation after the equivalent of a few weeks of use in a proton therapy treatment room (about 5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> protons). For PET detectors in an in-room setup, detector performance was unchanged even after an irradiation equivalent to three years of use in a treatment room (3 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> protons).

Evidence-based Peer Review for Radiation Therapy – Updated Review of the Literature with a Focus on Tumour Subsite and Treatment Modality

Technological advances in radiation therapy permit steep dose gradients from the target to spare normal tissue, but increase the risk of geographic miss. Suboptimal target delineation adversely affects clinical outcomes. Prospective peer review is a method for quality assurance of oncologists' radiotherapy plans. Published surveys suggest it is widely implemented. However, it may not be feasible to review every case before commencement of radiation therapy in all departments. The rate of plan changes following peer review of cases without a specific subsite or modality is typically around 10%. Stereotactic body radiation therapy, head and neck, gynaecological, gastrointestinal, haematological and lung cases are associated with higher rates of change of around 25%. These cases could thus be prioritised for peer review. Other factors may limit peer review efficacy including organisational culture, time constraints and the physical environment in which sessions are held. Recommendations for peer review endorsed by the American Society for Radiation Oncology were made available in 2013, but a number of relevant studies have been published since. Here we review and update the literature, and provide an updated suggestion for the implementation of peer review to serve as an adjunct to published guidelines. This may help practitioners evaluate their current processes and maximise the utility and effectiveness of peer review sessions.

The potential of polymer gel dosimeters for 3D MR-IGRT quality assurance

Advances in radiotherapy technology have enabled more accurate delivery of radiation doses to anatomically complex tumor volumes, while sparing surrounding tissues. The most recent advanced treatment modality combines a radiation delivery system (either Cobalt-60 therapy heads or linear accelerator) with a diagnostic magnetic resonance (MR) scanner to perform MR-image guided radiotherapy (MR-IGRT). For a radiation treatment plan to be delivered successfully with MR-IGRT the compliance with previously established criteria to validate the passing of such plans has to be confirmed. Due to the added strong magnetic field a new set of quality assurance standards has to be developed. Ideal detectors are MR-compatible, can capture complex dose distributions and can be read out with MRI. Polymer gels were investigated as potential three dimensional MR-IGRT quality assurance detectors.

Adoption of Radiation Technology Among Privately Insured Nonelderly Patients With Cancer in the United States, 2008 to 2014: A Claims-Based Analysis

Despite enthusiasm for advanced radiation technologies, understanding of their adoption in recent years is limited. The aim of this study was to elucidate utilization trends of conventional radiation, intensity-modulated radiotherapy (IMRT), brachytherapy, proton radiotherapy, stereotactic body radiotherapy (SBRT), and stereotactic radiosurgery (SRS) using a large convenience sample of irradiated patients with cancer identified from private insurance claims in the United States. The unit of analysis was a claim corresponding to a fraction of delivered radiotherapy from 2008 to 2014. Each claim was assigned a disease site on the basis of the diagnosis code and a radiation technology on the basis of the procedure code. In 2014, conventional radiation and IMRT constituted 56% and 39% of all radiation treatment claims, respectively, while brachytherapy constituted 2%, proton radiotherapy 1%, SBRT 1%, and SRS <1%. Compared with the first quarter of 2008, the proportional contribution of conventional radiation and brachytherapy to all radiation claims each decreased by 16% in the fourth quarter of 2014. In contrast, proportional contribution increased by 32% for IMRT, 83% for proton radiotherapy, 124% for SRS, and 309% for SBRT. Prostate cancer constituted 60% of all proton claims in 2008 but declined to 37% by 2014. SBRT was used to treat a variety of disease sites, most commonly primary lung (25%), prostate (12%), secondary bone (9%), and secondary lung (9%), in 2014. In this claims-based analysis of younger patients with private insurance, conventional radiation and IMRT were the most commonly used technologies from 2008 to 2014, while SBRT showed the most robust growth over the study period.

Dysphagia-optimised Intensity-modulated Radiotherapy Techniques in Pharyngeal Cancers: Is Anyone Going to Swallow it?

Dysphagia after primary chemoradiotherapy or radiation alone in pharyngeal cancers can have a devastating impact on a patient’s physical, social and emotional state. Establishing and validating efficient dysphagia-optimised radiotherapy techniques is, therefore, of paramount importance in an era where health-related quality of life measures are increasingly influential determinants of curative management strategies, particularly as the incidence of good prognosis, human papillomavirus-driven pharyngeal cancer in younger patients continues to rise. The preferential sparing achievable with intensity-modulated radiotherapy (IMRT) of key swallowing structures implicated in post-radiation dysfunction, such as the pharyngeal constrictor muscles (PCM), has generated significant research into toxicity-mitigating strategies. The lack of randomised evidence, however, means that there remains uncertainty about the true clinical benefits of the dosimetric gains offered by technological advances in radiotherapy. As a result, we feel that IMRT techniques that spare PCM cannot be incorporated into routine practice. In this review, we discuss the swallowing structures responsible for functional impairment, analyse the studies that have explored the dose–response relationship between these critical structures and late dysphagia, and consider the merits of reported dysphagia-optimised IMRT (Do-IMRT) approaches, thus far. Finally, we discuss the dysphagia/aspiration-related structures (DARS) study (ISRCTN 25458988), which is the first phase III randomised controlled trial designed to investigate the impact of swallow-sparing strategies on improving long-term function. To maximise patient benefits, improvements in radiation delivery will need to integrate with novel treatment paradigms and comprehensive rehabilitation strategies to eventually provide a patient-centric, personalised treatment plan.

MTE06.02 Radiotherapy Techniques in Lung Cancer

Dose escalation with conventional fractionation and concurrent platin-based chemotherapy within the RTOG 0617 trial has failed to show a survival benefit. Proton therapy has failed to show a reduction in radiation pneumonitis in comparison to intensity modulated photon radiotherapy at the same total dose according to the NCT 00915005 trial. Randomized trials for comparison of IMRT and 3D conformal radiotherapy are lacking. While randomized trials conducted so far failed to show an increment in survival by newer radiotherapy concepts on one hand, the old standard of giving 60 Gy with conventional fractionation and concurrent chemotherapy consolidated on the other. So where does the hope come from that technological advances in radiotherapy lead to an improved survival in locally advanced lung cancer, if not from randomized trials? It comes from many small precious components that can lead to an increase of loco-regional control by radiotherapy in locally advanced NSCLC, the primary goal of radiotherapy. First of all, the determination of tumor spread has been substantially improved by the introduction of FDG-PET/CT, by systematic mediastinal evaluation with EBUS-TBNA, and by brain MRI. The determination of tumor position during irradiation has been improved by stereoscopic KV imaging during irradiation or real-time magnetic resonance imaging and therefore tumor targeting can be optimized. Volumetric modulated arc therapy can deliver conformal dose distributions within a breath hold of 20 s. With hyperfractionated acceleration and concurrent chemotherapy, high biologically effective doses can be given for patients with locally advanced NSCLC resulting in similar survival and local control rates than with trimodality treatment. Integrated boost radiotherapy controlling dose gradients form gross tumor volume towards organs at risk as the contra-lateral bronchial wall or the esophagus has become feasible and is tested within prospective trials. Immunotherapy and molecular targeted therapies are upcoming as combination partners with radiotherapy in selected tumors. Proper patient selection criteria resulted long term survival as high as 30-45% in multicenter prospective trials in locally advanced NSCLC. These advantages have to be bundled into new radiotherapeutic concepts and tested against the standard of conventional fractionated radiotherapy up to 60 Gy and simultaneous chemotherapy in future well designed randomized trials. dose painting, dose escalation, image guidence, IMRT

Promoting the Appropriate Use of Advanced Radiation Technologies in Oncology: Summary of a National Cancer Policy Forum Workshop

Leaders in the oncology community are sounding a clarion call to promote "value" in cancer care decisions. Value in cancer care considers the clinical effectiveness, along with the costs, when selecting a treatment. To discuss possible solutions to the current obstacles to achieving value in the use of advanced technologies in oncology, the National Cancer Policy Forum of the National Academies of Sciences, Engineering, and Medicine held a workshop, "Appropriate Useof Advanced Technologies for Radiation Therapy and Surgery in Oncology" in July 2015. The present report summarizes the discussions related to radiation oncology. The workshop convened stakeholders, including oncologists, researchers, payers, policymakers, and patients. Speakers presented on key themes, including the rationale for a value discussion on advanced technology use in radiation oncology, the generation of scientific evidence for value of advanced radiation technologies, the effect of both scientific evidence and "marketplace" (or economic) factors on the adoption of technologies, and newer approaches to improving value in the practice of radiation oncology. The presentations were followed by a panel discussion with dialogue among the stakeholders. Challenges to generating evidence for the value of advanced technologies include obtaining contemporary, prospective, randomized, and representative comparative effectiveness data. Proposed solutions include the use of prospective registry data; integrating radiation oncology treatment, outcomes, and quality benchmark data; and encouraging insurance coverage with evidence development. Challenges to improving value in practice include the slow adoption of higher value and the de-adoption of lower value treatments. The proposed solutions focused on engaging stakeholders in iterative, collaborative, and evidence-based efforts to define value and promote change in radiation oncology practice. Recent examples of ongoing or successful responses to the discussed challenges were provided. Discussions of "value" have increased as a priority in the radiation oncology community. Practitioners in the radiation oncology community can play a critical role in promoting a value-oriented framework to approach radiation oncology treatment.

Twist1 promotes radioresistance in nasopharyngeal carcinoma.

With the development of advanced imaging and radiation technologies, radiotherapy has been employed as the principal treatment approach for nasopharyngeal carcinoma (NPC). So far, a number of patients still suffer from the failure of this treatment due to the acquired radioresistance, but the underlying mechanisms are still poorly defined. In this study, we found that Twist1, participating in a variety of cell biological process, was associated with the malignancy of NPC and could induce NPC radioresistance in vitro and in vivo. Mechanically, Twist1 could promote the accumulation of DNA damage repair and inhibit the apoptosis of NPC cells. Therefore, our study not only elucidates the significant role of Twist1 in radioresistance of NPC, but also highlights Twist1 as a potential therapeutic target for NPC.