Purpose: Within the STRA-MI-VT phase Ib/II trial (NCT04066517), the aim of this phantom study was to explore the feasibility of Cyberknife treatments on cardiac lesions by tracking as a single marker the lead tip of an implantable cardioverter defibrillator. The residual displacement of the lesion during the tracking was studied, planning margins were found and the dosimetric accuracy of the treatment was checked. Materials and methods: A lead was inserted into a phantom (EasyCube phantom, Sun Nuclear Co, USA) and then placed on the translating ExacTrac Gating System (BrainLAB AG, Germany). The phantom was rotated, a virtual lesion was identified and its displacement during the tracking was studied. Two plans were compared, calculated on the unrotated volume and on the envelope of the unrotated and the rotated volumes. The plans were delivered using the Cyberknife System (Accuray Inc, USA) and their dosimetric accuracy verified by gamma analysis with gafchromic films. Results: The residual margin increases enhancing the distance between the lead and the lesion. It is 4 mm for distance 0 cm and 5 mm for distance 5 cm. The coverage is reduced by 3.8% (interquartile range 2.5%-4.7%) when the dose is prescribed on the unrotated volume. All treatment plans are accurate and 3% 3 mm gamma analysis results are greater than 94%. Conclusions: Results showed that tracking with a single marker is feasible considering adequate residual planning margins. The volumes could be further reduced by using additional markers, for example by placing them on the patient's skin.

Background Ventricular tachycardia (VT) is a life-threatening condition, which usually implies the need of an implantable cardioverter defibrillator in combination with antiarrhythmic drugs and catheter ablation. Stereotactic body radiotherapy (SBRT) represents a common form of therapy in oncology, which has emerged as a well-tolerated and promising alternative option for the treatment of refractory VT in patients with structural heart disease. Objective In the STRA-MI-VT trial, we will investigate as primary endpoints safety and efficacy of SBRT for the treatment of recurrent VT in patients not eligible for catheter ablation. Secondary aim will be to evaluate SBRT effects on global mortality, changes in heart function, and in the quality of life during follow-up. Methods This is a spontaneous, prospective, experimental (phase Ib/II), open-label study (NCT04066517); 15 patients with structural heart disease and intractable VT will be enrolled within a 2-year period. Advanced multimodal cardiac imaging preceding chest CT-simulation will serve to elaborate the treatment plan on different linear accelerators with target and organs-at-risk definition. SBRT will consist in a single radioablation session of 25 Gy. Follow-up will last up to 12 months. Conclusions We test the hypothesis that SBRT reduces the VT burden in a safe and effective way, leading to an improvement in quality of life and survival. If the results will be favorable, radioablation will turn into a potential alternative option for selected patients with an indication to VT ablation, based on the opportunity to treat ventricular arrhythmogenic substrates in a convenient and less-invasive manner.

CyberKnife® Lung Optimized Treatment (LOT) allows the treatment of lung cancer without invasive fiducial implantation.The aim of this retrospective analysis was to evaluate the feasibility, toxicity and clinical outcome.One hundred fifteen patients (124 lesions) were treated with CyberKnife® using LOT.The median age was 72.6 years (range 31.8-90.3).From 124 treated lesions, 52 were with histopathological confirmation (41 primitive pulmonary cancers, 8 pulmonary metastases) and 72 as untyped tumors.For 5 patients (6 lesions) treatment was an in-field re-irradiation.Concomitant therapy was administered in 7 patients.Zero-View tracking was applied in 69 patients, 1-View in 33 patients, 2-View in 22 patients.The median total dose was 45 Gy (range 18-54), median dose/fraction was 15 Gy (range 4-18) with a median prescription isodose of 80% (range 68-85).The median planning target volume (PTV) was 25 cm 3 (range 3-195).The median followup was 20 months (range 7-47).Thirty-seven patients (32%) were alive with no evidence of disease, 39 patients (34%) were alive with clinically evident disease, and 38 patients (33%) died of the disease.The 1-and 2-year overall survival (OS) rate was 83% and 61%.The median time to progression was 19 months (95% confidence interval: 11-19 months), 1-and 2-year progression-free survival (PFS) rates were 62% and 41%, respectively.Smaller PTV was significantly associated with better OS, PFS and in-field PFS in univariate and multivariate analyses.Acute toxicity was observed in 36 patients (41%).Late toxicity was registered in 25 patients (29%).G3 late toxicity was observed in one patient (1.1%).Our data suggest that fiducial less-stereotactic body radiation therapy (SBRT) is a feasible, well-tolerated and potentially effective treatment with high compliance in the setting of inoperable patients due to concomitant disease or previous treatments.

Purpose or ObjectiveRadiation therapy of sinonasal carcinoma (SNC) is challenging to treat due to the tumors' location close to the brain and optical pathways.Proton therapy (PT) may be beneficial, as normal tissue may be spared, and the radiation-induced sequelae thus reduced.In order to perform proper patient selection and evaluate the effect of future PT, we aimed to objectively assess and record the organ-specific late sequelae and quality of life (QoL) in patients treated with intensity modulated radiotherapy (IMRT) for SNC. Material and MethodsA cross sectional study of all patients who were alive without recurrence and had received IMRT for SNC in the period January 2008 -January 2017 was performed.Of 26 eligible patients, 18 were enrolled in the study.They had been treated with either primary or postoperative RT with or without concomitant chemotherapy.Sequelae were evaluated with an objective ophthalmologic examination encompassing all parts of the eye and the visual pathway, blood samples visualizing all axes including synachten test, and the Brief Smell Identification Test (BSIT).QoL was assessed via EORTC QLQ-C30, EORTC QLQ-BN20, SNOT-22 and Hospital Anxiety the Depression Scale (HADS).In addition, diffusion weighted MRI scans of the brain and tests of neuropsychological function were performed, results of those tests are not yet available.Results 18 patients were enrolled, 13 males and 5 females.Median age was 70.5 years (range 47-83).They were treated with IMRT to a prescribed dose of 60-68 Gray (Gy) to T-sites in the nasal cavity (n=11) or the maxillary sinus (n=7).A significant correlation between max dose to the chiasm and grade 3 visual acuity impairment (p=0.046)(CTCAE ver.4.0) was revealed.Analysis of the function of the pituitary gland did not present any significant correlations; however, a clear tendency of higher doses related to more affected levels of hormones of the pituitary gland were present for all axes.BSIT showed impaired smell identification (≤ 8 points) in 15/18 patients.In the analysis of global QoL (EORTC QLQ-C30 and QLQ-BN20), social-, emotional-, and physical function were the most affected domains, whereas drowsiness and fatigue was the highest scoring symptoms.HADS revealed no abnormal depression scores, but 15/18 in the study population reported anxiety exceeding the norm.Anxiety was related to a poorer outcome in the global QoL score (p=0.029).Symptoms from the sinonasal area and the impact on the QoL were measured with the Sinonasal Outcome Test (SNOT-22).The median total score was 18 (range 6-77).The areas that affected the quality of life most were lack of smell or taste, thick nasal discharge, need to blow the nose, and blocked nose. ConclusionThe results of the study indicate substantial late radiation induced morbidity with a significant impact on the quality of life.Due to these findings, a larger nationwide study is now intended.

Purpose or ObjectivePENH is a recently coded module for simulation of proton transport in conjunction with the Monte Carlo (MC) code PENELOPE [1].The purpose of this work is to benchmark this module.PENH uses calculated differential cross sections for proton elastic collisions that include electron screening effects as well as nuclear structure effects.Proton-induced nuclear reactions are simulated from information in the ENDF-6 database [2], or from alternative nuclear databases in ENDF format (e.g., TENDL-2017). Material and MethodsResults from simulations with PENH are compared with simulation data obtained from TOPAS MC v3.1p2 [3] and RayStation 6 MC [4].In all simulations a measurementderived Fermi-Eyges [5] beam model, with nominal energy 225 MeV, was used.The beam model reproduced the phase-space of an IBA pencil beam (PB) scanning dedicated nozzle.The simulated geometry consisted of a water phantom with a 50 cm-thick layer of air upstream of it.Simulated dose results were compared to experimental data obtained with the MatriXX PT 2D detector (IBA Dosimetry) [6]. ResultsDepth dose profiles taken at varying radius from the central axis are shown in figure 1.The radial distance from the central axis at which the profiles are plotted appears above of each subfigure.All plots shown are normalized to the central axis dose at a depth of 3 cm.Excellent agreement is observed among the evaluated codes with the experimental data up to 3 cm from the central axis, that is, at the halo region where the dose drops three orders of magnitude from the maximum dose.Results from RayStation MC were smoothed with a moving average filter.Results from TOPAS MC coincide with experimental data up to six orders of magnitude below the maximum.Results from both RayStation and PENH qualitatively reproduce the experimental behavior in the low dose regions from three to six orders of magnitude below the maximum.