Magnetic resonance linear accelerator technology and adaptive radiation therapy: An overview for clinicians.

Radiation therapy (RT) continues to play an important role in the treatment of cancer. Adaptive RT (ART) is a novel method through which RT treatments are evolving. With the ART approach, computed tomography or magnetic resonance (MR) images are obtained as part of the treatment delivery process. This enables the adaptation of the irradiated volume to account for changes in organ and/or tumor position, movement, size, or shape that may occur over the course of treatment. The advantages and challenges of ART maybe somewhat abstract to oncologists and clinicians outside of the specialty of radiation oncology. ART is positioned to affect many different types of cancer. There is a wide spectrum of hypothesized benefits, from small toxicity improvements to meaningful gains in overall survival. The use and application of this novel technology should be understood by the oncologic community at large, such that it can be appropriately contextualized within the landscape of cancer therapies. Likewise, the need to test these advances is pressing. MR-guided ART (MRgART) is an emerging, extended modality of ART that expands upon and further advances the capabilities of ART. MRgART presents unique opportunities to iteratively improve adaptive image guidance. However, although the MRgART adaptive process advances ART to previously unattained levels, it can be more expensive, time-consuming, and complex. In this review, the authors present an overview for clinicians describing the process of ART and specifically MRgART.

Contemporary radiotherapy: present and future.

Oncology care is increasingly a multidisciplinary endeavour, and radiation therapy continues to have a key role across the disease spectrum in nearly every cancer. However, the field of radiation oncology is still one of the most poorly understood of the cancer disciplines. In this Review, we attempt to summarise and contextualise developments within the field of radiation oncology for the non-radiation oncologist. We discuss advancements in treatment technologies and imaging, followed by an overview of the interplay with advancements in systemic therapy and surgical techniques. Finally, we review new frontiers in radiation oncology, including advances within the metastatic disease continuum, reirradiation, and emerging types of radiation therapy.

A Century of Fractionated Radiotherapy: How Mathematical Oncology Can Break the Rules.

Radiotherapy is involved in 50% of all cancer treatments and 40% of cancer cures. Most of these treatments are delivered in fractions of equal doses of radiation (Fractional Equivalent Dosing (FED)) in days to weeks. This treatment paradigm has remained unchanged in the past century and does not account for the development of radioresistance during treatment. Even if under-optimized, deviating from a century of successful therapy delivered in FED can be difficult. One way of exploring the infinite space of fraction size and scheduling to identify optimal fractionation schedules is through mathematical oncology simulations that allow for in silico evaluation. This review article explores the evidence that current fractionation promotes the development of radioresistance, summarizes mathematical solutions to account for radioresistance, both in the curative and non-curative setting, and reviews current clinical data investigating non-FED fractionated radiotherapy.

Insights into the theranostic value of precision medicine on advanced radiotherapy to breast cancer.

Breast cancer is the most common cancer in women worldwide. "Breast cancer" encompasses a broad spectrum of diseases (i.e., subtypes) with significant epidemiological, clinical, and biological heterogeneity. Each of these subtypes has a different natural history and prognostic profile. Although tumour staging (TNM classification) still provides valuable information in the overall management of breast cancer, the current reality is that clinicians must consider other biological and molecular factors that directly influence treatment decision-making, including extent of surgery, indication for chemotherapy, hormonal therapy, and even radiotherapy (and treatment volumes). The management of breast cancer has changed radically in the last 15 years due to significant advances in our understanding of these tumours. While these changes have been extremely positive in terms of surgical and systemic management, they have also created significant uncertainties concerning integration of local and locoregional radiotherapy into the therapeutic scheme. In parallel, radiotherapy itself has also experienced major advances. Beyond the evident technological advances, new radiobiological concepts have emerged, and genomic data and other patient-specific factors must now be integrated into individualized treatment approaches. In this context, "precision medicine" seeks to provide an answer to these open questions and uncertainties. Although precision medicine has been much discussed in the last five years or so, the concept remains somewhat ambiguous, and it often appear to be used as a "catch-all" term. The present review aims to clarify the meaning of this term and, more importantly, to critically evaluate the role and impact of precision medicine on breast cancer radiotherapy. Finally, we will discuss the current and future of precision medicine in radiotherapy.

Radiotheranostics: a roadmap for future development.

Radiotheranostics, injectable radiopharmaceuticals with antitumour effects, have seen rapid development over the past decade. Although some formulations are already approved for human use, more radiopharmaceuticals will enter clinical practice in the next 5 years, potentially introducing new therapeutic choices for patients. Despite these advances, several challenges remain, including logistics, supply chain, regulatory issues, and education and training. By highlighting active developments in the field, this Review aims to alert practitioners to the value of radiotheranostics and to outline a roadmap for future development. Multidisciplinary approaches in clinical trial design and therapeutic administration will become essential to the continued progress of this evolving therapeutic approach.

Neurologic complications of melanoma.

Neurologic complications are common in patients with melanoma and are often associated with a poor prognosis. In an era with new, effective treatments, patients are living longer, and this has resulted in an increase in complications of both the disease and the therapy. A multidisciplinary approach to neurologic complications in patients with melanoma, with involvement from medical oncology, neuro-oncology, radiation oncology, and often neurosurgery, is necessary. In this review, neurologic complications of melanoma, including clinical implications and treatment strategies, are described.

Radiomics in radiation oncology-basics, methods, and limitations.

Over the past years, the quantity and complexity of imaging data available for the clinical management of patients with solid tumors has increased substantially. Without the support of methods from the field of artificial intelligence (AI) and machine learning, a complete evaluation of the available image information is hardly feasible in clinical routine. Especially in radiotherapy planning, manual detection and segmentation of lesions is laborious, time consuming, and shows significant variability among observers. Here, AI already offers techniques to support radiation oncologists, whereby ultimately, the productivity and the quality are increased, potentially leading to an improved patient outcome. Besides detection and segmentation of lesions, AI allows the extraction of a vast number of quantitative imaging features from structural or functional imaging data that are typically not accessible by means of human perception. These features can be used alone or in combination with other clinical parameters to generate mathematical models that allow, for example, prediction of the response to radiotherapy. Within the large field of AI, radiomics is the subdiscipline that deals with the extraction of quantitative image features as well as the generation of predictive or prognostic mathematical models. This review gives an overview of the basics, methods, and limitations of radiomics, with a focus on patients with brain tumors treated by radiation therapy.

Applications of radiomics and machine learning for radiotherapy of malignant brain tumors.

BACKGROUND: Magnetic resonance imaging (MRI) and amino acid positron-emission tomography (PET) of the brain contain a vast amount of structural and functional information that can be analyzed by machine learning algorithms and radiomics for the use of radiotherapy in patients with malignant brain tumors. METHODS: This study is based on comprehensive literature research on machine learning and radiomics analyses in neuroimaging and their potential application for radiotherapy in patients with malignant glioma or brain metastases. RESULTS: Feature-based radiomics and deep learning-based machine learning methods can be used to improve brain tumor diagnostics and automate various steps of radiotherapy planning. In glioma patients, important applications are the determination of WHO grade and molecular markers for integrated diagnosis in patients not eligible for biopsy or resection, automatic image segmentation for target volume planning, prediction of the location of tumor recurrence, and differentiation of pseudoprogression from actual tumor progression. In patients with brain metastases, radiomics is applied for additional detection of smaller brain metastases, accurate segmentation of multiple larger metastases, prediction of local response after radiosurgery, and differentiation of radiation injury from local brain metastasis relapse. Importantly, high diagnostic accuracies of 80-90% can be achieved by most approaches, despite a large variety in terms of applied imaging techniques and computational methods. CONCLUSION: Clinical application of automated image analyses based on radiomics and artificial intelligence has a great potential for improving radiotherapy in patients with malignant brain tumors. However, a common problem associated with these techniques is the large variability and the lack of standardization of the methods applied.

Molecular Imaging for Particle Therapy: Current Approach and Future Directions.

During the last decades, radiation oncology has been subject to a number of technological innovations. Particle therapy has evolved in parallel to the modern high-precision photon radiotherapy techniques and offers a superior dose distribution with decreased integral dose to healthy tissues. With advancing precision of treatment, the necessity for accurate and confident target volume delineation is rising. When morphological imaging reaches its limitations, molecular imaging can provide valuable information.

How rapid advances in imaging are defining the future of precision radiation oncology.

Imaging has an essential role in the planning and delivery of radiotherapy. Recent advances in imaging have led to the development of advanced radiotherapy techniques-including image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic body radiotherapy and proton beam therapy. The optimal use of imaging might enable higher doses of radiation to be delivered to the tumour, while sparing normal surrounding tissues. In this article, we review how the integration of existing and novel forms of computed tomography, magnetic resonance imaging and positron emission tomography have transformed tumour delineation in the radiotherapy planning process, and how these advances have the potential to allow a more individualised approach to the cancer therapy. Recent data suggest that imaging biomarkers that assess underlying tumour heterogeneity can identify areas within a tumour that are at higher risk of radio-resistance, and therefore potentially allow for biologically focussed dose escalation. The rapidly evolving concept of adaptive radiotherapy, including artificial intelligence, requires imaging during treatment to be used to modify radiotherapy on a daily basis. These advances have the potential to improve clinical outcomes and reduce radiation-related long-term toxicities. We outline how recent technological advances in both imaging and radiotherapy delivery can be combined to shape the future of precision radiation oncology.

Recent advances in gynecologic radiation oncology.

PURPOSE OF REVIEW: Radiation has long been a primary treatment modality in locally advanced gynecologic carcinomas and a tool for palliation of metastatic disease. Here we review advances in imaging and radiation technologies and the corresponding clinical evolution of the role for radiation oncology in the treatment of gynecologic malignancies. RECENT FINDINGS: Advances in MRI are impacting diagnosis, radiation target delineation, planning, treatment delivery, and response assessment. The combination of MRI and PET-computed tomography (PET-CT) has the potential to significantly change treatment recommendations as compared with a single imaging modality. Advances in radiation delivery including intensity modulated radiation therapy (IMRT) and stereotactic ablative radiotherapy (SABR) have expanded the role for radiation in the definitive treatment of high risk and oligometastatic ovarian cancer. Finally, global disparities in oncology resources has led to the development of resource stratified treatment guidelines for gynecologic malignancies. The use of ultrasound for brachytherapy planning may help improve access to this critical treatment modality. SUMMARY: As imaging and radiation technologies advance, the indications for radiation in the treatment of gynecologic malignancies continues to evolve. Here we review the changing landscape of radiation oncology in the multidisciplinary management of gynecologic cancers.

Trends in combined radio-chemotherapy for locally advanced rectal cancer: a survey among radiation oncology centers of Sicily region on behalf of AIRO.

AIM: To conduct a survey among Sicilian centers of radiation oncology belonging to Associazione Italiana di Radioterapia ed Oncologia Clinica (AIRO), to record the different methods of integration of radio-chemotherapy both in neoadjuvant and adjuvant settings, to evaluate surgical procedures in relation to the sphincter preservation and to report the different toxicity profiles of the treatment strategies. METHODS: A questionnaire was sent at the end of 2017 to all the radiation oncology centers of Sicily region in order to collect the data from individual centers and the treatment characteristics retrospectively over the previous 5 years, from 2012 to 2016. The required data were collected from 13 centers out of 17 which, in relation to the single catchment areas, correspond to approximately 85% of the Sicilian population. The requested data concerned the type of integrated treatment (neoadjuvant vs adjuvant vs radical), combination with chemotherapy (induction, concomitant, adjuvant), type of surgical intervention (sphincter-saving vs abdomino-perineal resection), disease stage, schedule and radiotherapy technique adopted, as well as toxicity detected over the treatment period. RESULTS: A total of 784 pts (M/F: 509/275) were treated between 2012 and 2016, with a median age of 67 years (range 25-92). The majority of patients was treated in the neoadjuvant phase (62% of the total) compared to the adjuvant phase (31%) and to those treated radically (7%). Twenty-five percent of patients did not receive combination chemotherapy mainly for cardiovascular problems. Chemotherapy used concomitantly to radiotherapy was single-agent capecitabine (73% of patients) or 5-fluorouracil (27%). The use of chemotherapy alone before concomitant treatment is more common for patients treated in the adjuvant phase (64% of this subgroup), while 14% of patients treated in the neoadjuvant phase received induction chemotherapy before the concomitant phase; in both cases of chemotherapy alone, the majority of patients (91%) received oxaliplatin-based protocols (FOLFOX/XELOX/CAPOX). Few patients (3%) received chemotherapy alone after the concomitant phase. Information on the surgical treatment received is available for 88% of the sample. Of these, 93% received a surgical treatment. The overall rate of sphincter-saving surgery (anterior resection) was 72%, but the contribution of neoadjuvant treatment allowed to reach a rate of 83% in this subgroup (against 65% found in the subgroup of patients treated in adjuvant phase). Traditional radiotherapy schedule (45-50 Gy in 25-28 fractions) was used in 90% of patients, of which an intensified treatment in neoadjuvant phase (45 Gy + boost of 9-10 Gy) was used in 11% of patients. A short-course regimen (25 Gy in 5 fraction) in neoadjuvant setting was opted rarely (7%). Three-dimensional conformal technique was preferred over intensity-modulated ones (73% vs 27%). Toxicity was mainly of grade I-II CTCAE (skin 23%, gastrointestinal 39%, genitourinary 14%) compared to grade III (gastrointestinal 4%, genitourinary and hematological < 1%). Interestingly, the toxicity rates were significantly higher in the adjuvant group compared to the neoadjuvant (GI: 58% vs 31%, GU: 21% vs 10%). CONCLUSION: The present survey shows that in the Sicily region integrated therapies for rectal cancer have allowed a neoadjuvant approach in the majority of patients, thus resulting in a greater use of sphincter conservative surgery. The toxicity has also been reported to be significantly less in this treatment setting.

A retrospective analysis of radiation oncology related scientific articles in the journal Veterinary Radiology and Ultrasound: Trends over 40 years (1976-2015).

The journal Veterinary Radiology & Ultrasound is a veterinary specialty journal devoted to the fields of veterinary diagnostic imaging and radiation oncology. The purpose of this retrospective, observational study is to evaluate progressive trends in radiation oncology articles published in Veterinary Radiology & Ultrasound during the 40-year period (1976-2015) and describe a shift of trends through several viewpoints. This 40-year period was divided into four subperiods: Period 1 (1976-1985), Period 2 (1986-1995), Period 3 (1996-2005), and Period 4 (2006-2015). These articles were divided into six categories based on the nature of the study: 1) studies related to teletherapy with endpoints being patient outcome, 2) radiation therapy dosimetry/planning, 3) patient setup, 4) reviews, 5) case reports, and 6) others. The number of radiation oncology articles in Veterinary Radiology & Ultrasound has increased over the 40-year period. The number of authors per article has increased between Periods 1 and 3. The number of articles related to linear accelerator has increased between Periods 3 and 4. The median number of treated patients per clinical article related to teletherapy ranged from 15 to 21, which has not changed significantly over the 40-year period. The most commonly used radiation therapy protocols during Periods 2 and 3 were fine-fractionated protocols (defined as 10 or more fractions), whereas coarse-fractionated protocols were more common during Periods 1 and 4. Findings from this study highlight the notable changes of trends in veterinary radiation oncology articles published in Veterinary Radiology & Ultrasound, which clearly reflect changes in the field of veterinary radiation oncology during the past 40 years.

The state of survivorship care in radiation oncology: Results from a nationally distributed survey.

BACKGROUND: Survivorship care has become an increasingly critical component of oncologic care as well as a quality practice and reimbursement metric. To the authors' knowledge, the current climate of survivorship medicine in radiation oncology has not been investigated fully. METHODS: An institutional review board-approved, Internet-based survey examining practices and preparedness in survivorship care was distributed to radiation oncology practices participating in the American College of Radiology Radiation Oncology Practice Accreditation program between November 2016 and January 2017. A total of 78 surveys were completed. Among these, 2 were nonphysicians, resulting in 76 evaluable responses. RESULTS: Radiation oncologists (ROs) frequently reported that they are the primary provider in the evaluation of late toxicities and the recurrence of primary cancer. Although approximately 68% of ROs frequently discuss plans for future care with survivors, few provide a written survivorship care plan to their patients (18%) or the patients' primary care providers (24%). Patient prognosis, disease site, and reimbursement factors often influence the provision of survivorship care. Although ROs report that several platforms offer training in survivorship medicine, the quality of these resources is variable and extensive instruction is rare. Fewer than one-half of ROs believe they are expertly trained in survivorship care. CONCLUSIONS: ROs play an active role within the multidisciplinary team in the cancer-related follow-up care of survivors. Investigation of barriers to the provision of survivorship care and optimization of service delivery should be pursued further. The development of high-quality, easily accessible educational programming is needed so that ROs can participate more effectively in the care of cancer survivors. Cancer 2018;124:2653-60. © 2018 American Cancer Society.

Recent advances in radiation oncology: multimodal targeting of high risk and recurrent prostate cancer.

PURPOSE OF REVIEW: The overview summarizes recent developments in radiation oncology for high risk and recurrent prostate cancer. RECENT FINDINGS: A number of well known phase III prostate hypofractionated radiation therapy (HFxRT) trials were finally published with long-term follow-ups. These trials demonstrate patterns of equivalent tumor control with several showing worse toxicity rates. The ASCENDE-RT randomized trial demonstrated the superiority of brachytherapy boost in intermediate and high-risk prostate cancer. Important randomized trials show a clear benefit to androgen deprivation therapy (ADT) in both intermediate-risk prostate cancer and postprostatectomy patients with rising PSA. Finally, the first randomized trial of metastasis-directed therapy showed a delay in time to ADT and biochemical failures in oligometastatic prostate cancer. SUMMARY: The use of brachytherapy boost in high-risk disease and ADT in locally recurrent cancer after prostatectomy are practice changing given the magnitude of benefit seen in the randomized trials. The benefit of metastasis-directed therapy in oligometastatic prostate cancer must be validated in a larger randomized trial. However, hypofractionated radiation therapy requires further long-term follow-up so that late toxicity risk can be accurately assessed before it becomes a standard of care in prostate cancer.

Health services research in German radiation oncology: new opportunities to advance cancer care.

BACKGROUND: Health services research (HSR) is of increasing relevance to scientists, health-care providers, and clinicians. Complex population-based secondary data are a key source of information for analyses of health-care effects in radiation oncology. METHODS: In this short paper, we examine potential applications of secondary data focusing on statistics from the diagnosis-related groups (DRG). This data set incorporating all hospitalized cases in Germany is based on claims of reimbursements and is provided by the Research Data Centers (RDC) of the Federal Statistical Office and the Statistical Offices of the federal states. A short outlook regarding other data sources is also presented. RESULTS: In radiation oncology, secondary data such as the DRG statistics have rarely been used to examine health-care effects, despite their great potential for reporting effects in a broad population-based setting. Furthermore, for most data sources, the application to use these data is accessible with minor effort. However, data concerning outpatient care are difficult to analyze on a comparable level. CONCLUSION: DRG statistics and related secondary data provide a remarkable source of information for analyses of health-care-related effects in radiation oncology.

Biological imaging for individualized therapy in radiation oncology: part II medical and clinical aspects.

Positron emission tomography and multiparametric MRI provide crucial information concerning tumor extent and normal tissue anatomy. Moreover, they are able to visualize biological characteristics of the tumor, which can be considered in the radiation treatment planning and monitoring. In this review we discuss the impact of biological imaging positron emission tomography and multiparametric MRI for radiation oncology, based on the data of the literature and on the experience of our own institution in this field.

Biological imaging for individualized therapy in radiation oncology: part I physical and technical aspects.

Recently, there has been an increase in the imaging modalities available for radiotherapy planning and radiotherapy prognostic outcome: dual energy computed tomography (CT), dynamic contrast enhanced CT, dynamic contrast enhanced magnetic resonance imaging (MRI), diffusion-weighted MRI, positron emission tomography-CT, dynamic contrast enhanced ultrasound, MR spectroscopy and positron emission tomography-MR. These techniques enable more precise gross tumor volume definition than CT alone and moreover allow subvolumes within the gross tumor volume to be defined which may be given a boost dose or an individual voxelized dose prescription may be derived. With increased plan complexity care must be taken to immobilize the patient in an accurate and reproducible manner. Moreover the physical and technical limitations of the entire treatment planning chain need to be well characterized and understood, interdisciplinary collaboration ameliorated (physicians and physicists within nuclear medicine, radiology and radiotherapy) and image protocols standardized.

The rise of reimbursement-based medicine: the case of bone metastasis radiation treatment.

It has been hypothesised that the reimbursement system pertaining to radiotherapy is influencing prescription practices for patients with cancer with bone metastases. In this paper, we present and discuss the results of an empirical study that was undertaken on patient records, referred to radiotherapy for the treatment of bone metastases, in a medium-size city, in southern Brazil, during the period of March 2006 to March 2014. Our findings seem to confirm this hypothesis: after a change in the reimbursement method, radiation prescriptions were adapted accordingly, in order to maximise profits. Once such patients become highly vulnerable due to their diagnoses, they also become susceptible to a subtle form of exploitation; physicians let patients believe that more radiation will be better for their health, and they do so despite knowing otherwise, and as it seems, out of pecuniary interests.

Checkpoint inhibitors and radiation treatment in Hodgkin's lymphoma : New study concepts of the German Hodgkin Study Group.

BACKGROUND: Patients with classical Hodgkin's lymphoma (cHL) have a good prognosis even in advanced stages. However, combined chemo- and radiotherapy, as the standard of care, is also associated with treatment-related toxicities such as organ damage, secondary neoplasias, infertility, or fatigue and long-term fatigue. Many patients suffer from this burden although their cHL was cured. Therefore, the efficacy of immune checkpoint inhibitors like anti-PD1/PD-L1 antibodies in the treatment of solid cancers and also in HL offers new options. A remarkable and durable response rate with a favorable toxicity profile was observed in heavily pretreated cHL patients. METHODS: Planning to perform prospective randomized clinical trials in the content of radio-immune treatment in patients with Hodgkin's lymphoma (HL), we transferred the results of preliminary clinical studies and basic research in clinical relevant study concepts. RESULTS: Based on these promising early phase trial data, the German Hodgkin Study Group (GHSG) will investigate innovative treatment regimens in upcoming phase II trials. CONCLUSION: The therapeutic efficacy and potential synergies of anti-PD1 antibodies in combination with chemo- or radiotherapy will be investigated in various settings of HL.