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Highlights • There is a dosimetric advantage for IMPT over VMAT in patients receiving radiation treatment for pilocytic astrocytoma. • The novel RPSS is a practical scoring system making translation of dose differences into clinically relevant endpoints possible. • Following the lower RPSS toxicity scores for IMPT, less toxicity is likely to be expected in patients treated with IMPT vs VMAT in this pilocytic astrocytoma cohort., Background and purpose Proton therapy is expected to outperform photon-based treatment regarding organs at risk (OAR) sparing but to date there is no method to practically measure clinical benefit. Here, we introduce the novel ROCOCO Performance Scoring System (RPSS) translating dose differences into clinically relevant endpoints and apply this to a treatment plan comparison of volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) in 20 pilocytic astrocytoma patients. Material and methods The RPSS was developed on the basis of expert-based weighting factors and toxicity scores per OAR. The imaging datasets of 20 pilocytic astrocytoma patients having undergone radiotherapy were included in this in silico dosimetric comparison trial as proof of principle. For each of these patients, treatment plans to a total dose of 54 Gy (RBE) were generated for VMAT and IMPT and these were compared regarding radiation dose to the clinical target volume (CTV) and OARs. The RPSS was calculated for each treatment plan comparing VMAT and IMPT. Results In 40 analysed treatment plans, the average and low dose volumes to various OARs were significantly reduced when using IMPT compared to VMAT (p

Stereotactic body radiation therapy (SBRT) has emerged as a treatment modality for selected patients with oligometastatic non-small-cell lung cancer (NSCLC). The objectives of this systematic review were to explore the benefits and risks of SBRT for extracranial oligometastatic NSCLC. The MEDLINE, Embase, PubMed, and CENTRAL databases were searched for relevant articles from January 1, 2000 to July 23, 2019. Fully published phase III or phase II trials of any sample size were included. Retrospective series published in manuscript form with at least 50 patients were also included. Four prospective phase II randomized trials (total, 188 participants), 4 prospective non-randomized studies (total, 140 participants), and eleven retrospective studies (total, 1288 participants) were included in this systematic review. A variety of dose fractionation schemes were used. The median overall survival (OS) ranged from 13.5 to 55 months. Progression-free survival (PFS) ranged from 4.4 to 14.7 months. Quality of life outcomes were reported in 2 studies. None of the studies reported symptom control outcomes. There are no fully completed phase III randomized trials that clarify the risks and benefits of SBRT for oligometastatic NSCLC. Higher PFS and OS with SBRT were reported in 4 phase II randomized studies. The results from mature phase III randomized data regarding whether SBRT for oligometastatic NSCLC benefits patients in terms of OS, PFS, quality of life, and symptom control are needed.

Eekers et al. have recently proposed a neuro-oncology atlas, which was co-authored by most centers associated in the European Proton Therapy Network (EPTN; Figure 1). With the introduction of new treatment techniques, such as integrated magnetic resonance imaging and linear accelerators (MR-linac) or particle therapy, the prediction of clinical efficacy of these more costly treatment modalities becomes more relevant. One of the side-effects of brain irradiation, being cognitive decline, is one of the toxicities most difficult to measure and predict. In order to validly compare different treatment modalities, 1) a uniform nomenclature of the organs at risk (OARs), 2) uniform atlas-based delineation [e.g., Eekers et al.], 3) long-term follow-up data with standardized cognitive tests, 4) a large patient population, and 5) (thus derived) validated normal tissue complication probability (NTCP) models are mandatory. Apart from the Gondi model, in which the role of the dose to 40% of both hippocampi (HC) proves to be significantly related to cognition in 18 patients, no similar models are available. So there is a strong need for more NTCP models, on HC, brain tissue and possible other relevant brain structures. In this review we summarize the available evidence on the role of the posterior cerebellum as a possible new organ at risk for cognition, which is deemed relevant for irradiation of brain and head and neck tumors. (C) 2017 The Authors. Published by Elsevier Ireland Ltd on behalf of European Society for Radiotherapy and Oncology.