Recommendations for radiation therapy in oligometastatic prostate cancer:An ESTRO-ACROP Delphi consensus

Background and purpose: Oligometastatic prostate cancer is a new and emerging treatment field with only few prospective randomized studies published so far. Despite the lack of strong level I evidence, metastasis-directed therapies (MDT) are widely used in clinical practice, mainly based on retrospective and small phase 2 studies and with a large difference across centers. Pending results of ongoing prospec-tive randomized trials, there is a clear need for more consistent treatment indications and radiotherapy practices.Material and methods: A European Society for Radiotherapy and Oncology (ESTRO) Guidelines Committee consisting of radiation oncologists' experts in prostate cancer was asked to answer a dedicated question-naire, including 41 questions on the main controversial issues with regard to oligometastatic prostate cancer.Results: The panel achieved consensus on patient selection and routine use of prostate-specific mem-brane antigen positron emission tomography (PSMA PET) imaging as preferred staging and restaging imaging. MDT strategies are recommended in the de novo oligometastatic, oligorecurrent and oligopro-gressive disease setting for nodal, bone and visceral metastases. Radiation therapy doses, volumes and techniques were discussed and commented.Conclusion: These recommendations have the purpose of providing standardization and consensus to optimize the radiotherapy treatment of oligometastatic prostate cancer until mature results of random-ized trials are available.AT would like to acknowledge the support of Cancer Research UK (C33589/A28284 and C7224/A28724) . This project represents independent research supported by the National Institute for Health research (NIHR) Biomedical Research Centre at The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research, London. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care

Delineation of the Prostate Bed: The “Invisible Target” Is Still an Issue?

For pathological high-risk prostate cancer, adjuvant irradiation has shown a survival benefit. Phase III studies have highlighted that half men would face biochemical relapse and would be candidate for radiotherapy at adjuvant or salvage times. Despite at least four published international contouring guidelines from different collaborative groups, discrepancies remain for volumes, delineation, and margins to be considered in order to optimize radiotherapy planning. This article from “Groupe d’Etude des Tumeurs UroGénitales (GETUG)” members will focus on controversies to help clinicians to create best volume delineation for adjuvant or salvage post prostatectomy radiotherapy

Radiomics and Machine Learning in Anal Squamous Cell Carcinoma: A New Step for Personalized Medicine?

Anal squamous cell carcinoma (ASCC) is an uncommon yet rising cancer worldwide. Definitive chemo-radiation (CRT) remains the best curative treatment option for non-metastatic cases in terms of local control, recurrence-free and progression-free survival. Still, despite overall good results, with 80% five-year survival, a subgroup of ASCC patients displays a high level of locoregional and/or metastatic recurrence rates, up to 35%, and may benefit from a more aggressive strategy. Beyond initial staging, there is no reliable marker to predict recurrence following CRT. Imaging, mostly positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI), bears an important role in the diagnosis and follow-up of ASCC. The routine use of radiomics may enhance the quality of information derived from these modalities. It is thought that including data derived from radiomics into the input flow of machine learning algorithms may improve the prediction of recurrence. Although some studies have shown glimmers of hope, more data is needed before offering practitioners tools to identify high-risk patients and enable extensive clinical application, especially regarding the matters of imaging normalization, radiomics process standardization and access to larger patient databases with external validation in order to allow results extrapolation. The aim of this review is to present a critical overview from this data

Use of metrics to quantify IMRT and VMAT treatment plan complexity: A systematic review and perspectives

International audiencePurpose: Fixed-field intensity modulated radiation therapy (FF-IMRT) or volumetric modulated arc therapy (VMAT) beams complexity is due to fluence fluctuation. Pre-treatment Quality Assurance (PTQA) failure could be linked to it. Several plan complexity metrics (PCM) have been published to quantify this complexity but in a heterogeneous formalism. This review proposes to gather different PCM and to discuss their eventual PTQA failure identifier abilities. Methods and materials: A systematic literature search and outcome extraction from MEDLINE/PubMed (National Center for Biotechnology Information, NCBI) was performed. First, a list and a synthesis of available PCM is made in a homogeneous formalism. Second, main results relying on the link between PCM and PTQA results but also on other uses are listed. Results: A total of 163 studies were identified and n = 19 were selected after inclusion and exclusion criteria application. Difference is made between fluence and degree of freedom (DOF)-based PCM. Results about the PCM potential as PTQA failure identifier are described and synthesized. Others uses are also found in quality, big data, machine learning and audit procedure. Conclusions: A state of the art is made thanks to this homogeneous PCM classification. For now, PCM should be seen as a planning procedure quality indicator although PTQA failure identifier results are mitigated. However limited clinical use seems possible for some cases. Yet, addressing the general PTQA failure prediction case could be possible with the big data or machine learning help

Challenges in radiobiology – technology duality as a key for a risk-free α/β ratio

International audienceSince radiotherapy discovery, prediction of biological response to ionizing radiation remains a major challenge. Indeed, several radiobiological models appeared through radiotherapy history. Nominal single dose so popular in the 1970s, was tragically linked to the dark years in radiobiology by underestimating the late toxicity of the high-dose fractions. The actual prominent linear-quadratic model continues to prove to be an effective tool in radiobiology. Mainly with its pivotal α/β ratio, which gives a reliable estimate of tissues sensitivity to fractions. Despite these arguments, this model experiences limitations with substantial doubts of α/β ratio values. Interestingly, the story of radiobiology since X-ray discovery is truly instructive and teaches modern clinicians to refine fractionation schemes. Many fractionation schemes have been tested with successes or dramas. This review retraces radiobiological models’ history, and confronts these models to new fractionation schemes, drawing a preventive message

Radiation Therapy in Resectable Intrathoracic Sarcomas. A Rare Cancer Network Study

This clinical study examines the use of adjuvant radiation therapy for resected intrathoracic sarcomas. Adjuvant radiation therapy was associated with improved local control. The impact of these results on long-term survival requires further evaluation in prospective clinical studies

Adaptive radiotherapy in routine: The radiation oncologist's point of view

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PET/CT-Based Salvage Radiotherapy for Recurrent Prostate Cancer After Radical Prostatectomy: Impact on Treatment Management and Future Directions

Biochemical recurrence is a clinical situation experienced by 20 to 40% of prostate cancer patients treated with radical prostatectomy (RP). Prostate bed (PB) radiation therapy (RT) remains the mainstay salvage treatment, although it remains non-curative for up to 30% of patients developing further recurrence. Positron emission tomography with computed tomography (PET/CT) using prostate cancer-targeting radiotracers has emerged in the last decade as a new-generation imaging technique characterized by a better restaging accuracy compared to conventional imaging. By adapting targeting of recurrence sites and modulating treatment management, implementation in clinical practice of restaging PET/CT is challenging the established therapeutic standards born from randomized controlled trials. This article reviews the potential impact of restaging PET/CT on changes in the management of recurrent prostate cancer after RP. Based on PET/CT findings, it addresses potential adaptation of RT target volumes and doses, as well as use of androgen-deprivation therapy (ADT). However, the impact of such management changes on the oncological outcomes of PET/CT-based salvage RT strategies is as yet unknown

International consensus guidelines for adjuvant radiation therapy for bladder cancer after radical cystectomy : update from an IBIS workgroup

PURPOSE: In 2016, international consensus clinical target volume (CTV) guidelines for adjuvant radiation treatment after radical cystectomy in patients with muscle-invasive bladder cancer with high risk for locoregional failure (LRF) were published. A subsequent external validation study recommended several CTV optimizations (CTV-OPT). This study aimed to update international consensus guidelines based on new clinical experiences. METHODS AND MATERIALS: Phase 1 (delineation interobserver variability): Four observers delineated the CTV of 9 patients post radical cystectomy, as in clinical practice. Interobserver agreement in contouring was evaluated using volume- and κ-statistics. Phase 2 (pattern of failure analysis): Among a prospective cohort of 72 patients treated with adjuvant radiation treatment, 11 developed LRF (10 available for review). LRFs were mapped in predefined pelvic subsites (ie, common, external and internal iliac, obturator and presacral node regions, and cystectomy bed), and their distance to CTV-OPT was measured. The actual delivered dose at each relapse site was calculated. Phase 3 (review CTV): Based on the results of phase 1 and 2, 5 senior radiation-oncologists (International Bladder Investigator Society) reviewed the published CTV borders and provided an update when indicated. RESULTS: Phase 1: The mean overall κ-value was 0.66 (range, 0.60-0.70), indicating substantial overall agreement per Landis-Koch criteria. Specific κ-values per area indicated for the common iliac and obturator node regions only slight and moderate variability, respectively. Phase 2: Thirteen out of 16 LRFs centers were not included in the CTV-OPT. Ten LRF sites received a median dose \u3c45 Gy, of which 6 were located in the cystectomy bed that was not included in the CTV because of negative radical cystectomy margins. Phase 3: Key recommendations by the panel were to include the entire common iliac node region and the cystectomy bed regardless of surgical margin status and a reaffirmation to not crop the CTV out of bowel. CONCLUSIONS: International consensus guidelines were updated