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Peach/nectarine is an important fruit tree crop in Europe and indeed world-wide. The registration of new cultivars, either for Plant Breeders' Rights or National Listing (PBR/NL) purposes in the European Union (EU), requires the completion of a distinctness, uniformity and stability (DUS) test in one of the EU Member States. The number of candidate cultivars and potentially required example cultivars entered for DUS testing is steadily increasing annually. Moreover, DUS testing of this type of tree crops requires the maintenance of large orchards, particularly with the aim of having a complete reference collection. In France, Hungary, Spain and Italy, peach tree breeding activity is characterized by an important number of cultivars available and a short turn-over of the cultivars. This situation will extend to new EU members states in the coming years, with the development of the European trade. However, although the diversification increases the number of segments, for each segment, new released cultivars are genetically closer and closer. The consequence is that it is now difficult in some cases to distinguish between cultivars. Clearly, developing means of "managing" reference collections is highly desirable in order to be able to compare candidate cultivars with the closest cultivars of common knowledge in the reference collections prior to planting them, and so reduce the number of cultivars that need to be grown, without eroding the strength of PBR and the relevance of DUS tests. Effective means of such a management include the definition of a standardised way to compare phenotypic data and to use molecular markers to eliminate the reference cultivars which do not need to be compared to the candidate cultivars. In peach tree, various molecular markers such as DNA microsatellites (SSR) have been developed and evaluated, but they have not yet been used for the characterization of large collections. Therefore, this project will generate a database compiling both phenotypic data, including standardised morphological descriptions and digital pictures, and a large data set of DNA profiles for 522 peach tree cultivars selected among the EU granted and listed cultivars.

Purpose: To aid the clinical implementation of a hybrid system of both in house and ‘off the shelf’ commercial components for stereotactic body radiation therapy (SBRT), utilizing the latest image-guided techniques. Materials and Methods: A new Elekta Synergy accelerator with Beam Modulator (4 mm leaves and maximum field size 21 × 16 cm2) was commissioned in the Pinnacle3® treatment planning system v.8.0d for routine patient care. Additionally, both imaging systems (MV and kV) were fully commissioned for routine portal imaging and cone beam CT. The Pinnacle3® system does not contain an algorithm that recognizes the fiducial markers of the stereotactic body, therefore custom software was written. The clinical implementation was undertaken in the following sequence: (1) volunteers (who received no radiation) were used to familiarize staff with the SBRT fitting and derive a simulation procedure; (2) a phantom was used to check that a point determined from the planning CT could be aligned on the linear accelerator using cone beam CT; (3) an enhanced Winston Lutz test was devised and performed to determine the coincidence of the rotation center points of the imaging equipment and the linear accelerator gantry, and (4) finally an ‘end-to-end’ test was performed to confirm the overall SBRT system performance. Results: Initial studies yielded a robust simulation procedure which placed limits on the maximum patient size that could be accommodated in the SBRT frame and the diaphragm compression that could be used for tumor immobilization. The maximum shift needed to bring two separate points in the stereotactic space into alignment by the cone beam CT system, determined using the grey value alignment algorithm, were 0.5 and 1.2 mm, respectively. The initial Winston Lutz test based on the room lasers alone found a maximum shift of 1.4 mm. By employing an enhanced alignment technique, standard for the CBCT system, the average difference was reduced to < 0.3 mm. Finally the ‘end-to-end’ test was successfully performed with a test phantom from an independent testing center. Conclusion: The commissioning of SBRT was greatly enhanced and accelerated by utilizing the MV and kV onboard imaging capabilities of a modern linear accelerator, e.g. EPID and CBCT, respectively. Cone beam CT validated that the isocenter transfer from the planning CT system to the stereotactic coordinate system of the SBRT frame was accurate and the enhanced MV imaging software gave an improvement to a well-established isocenter test (Winston Lutz).

International audience; Among fruit species, apricot (Prunus armeniaca L.) is characterized by a large increase in the number of registered and/or granted cultivars over the last decades, and by an effective interest at the European level. At the same time, an evolution concerning fruit quality attributes was observed globally among registered cultivars. In order to characterize this tendency, 172 cultivars in collection were observed. Representative fruit samples have been collected and their quality attributes such as fruit weight, firmness, colour, soluble solids content, and titratable acidity were considered. The impacts of genetic and geographic origin factors were evaluated. A significant increase in fruit firmness and colour, as well as a decrease in fruit acidity, was observed. No evolution on sugar content was noticed.

Purpose: To report the results of commissioning tests and the development of a quality assurance program for the commercial version (i.e., non‐research model) Elekta Synergy Cone Beam CT(CBCT) system. Methods and Materials: Our institution was one of the first sites in the US to install a commercial version of the Elekta Synergy Cone Beam CT system. A commissioning procedure was developed consisting of six parts: (1) System safety, (2) Geometric accuracy (i.e., agreement of MV and kV beam isocenters), (3) Image quality, (4) Algorithm accuracy, (5) Dose to patient, and (6) Quality assurance procedures. Results: The system passed all safety tests and agreement of MV/kV isocenters was found to be within 1 mm. Using a precisely moved skull phantom, reconstruction and alignment algorithm was found to be accurate within 1mm and 1 degree in each dimension. For 12 measurement points spanning a 9×9×15cm3 volume in a RANDO phantom, average agreement in x, y, and z coordinates was 0.010cm, −0.012cm, 0.022cm (SD: 0.021cm, 0.055cm, 0.021cm; Largest deviations: 0.06cm, 0.10cm, 0.05cm, respectively). Larger deviation for the y‐component can be partially attributed to CT slice thickness of 1 mm along that direction. Dose to patient depends on machine settings and was found not to exceed 6.3cGy in the highest setting used in our clinic (120kVp, 40mA, 40ms per frame, 360 degree scan, S20 field of view). A more typical dose for a full 360 degree scan is 4cGy. Conclusions: The procedures discussed in this presentation were applied to the Elekta Synergy CBCT system. They have been useful in identifying difficulties with the CBCT operation operation, including data transfer issues. System safety, geometric accuracy, and image quality checks are recommended to be performed on a monthly basis; algorithm accuracy and dose to patient checks are recommended to be performed annually.

Purpose: To demonstrate the strength of kV cone beam CT(CBCT) over MV portal imaging in the detection and quantification of pitch errors in prostate patients without use of internal fiducial markers. Additionally the cause and subsequent correction of large pitch variations was investigated as the daily use of CBCT had highlighted a small number of patients with deviations is set‐up of more than three degrees. Method and Materials: By using CBCT six variables can be corrected — three translations in the orthogonal axes as well as pitch, yaw, and roll. Five patients and RANDO phantom were studied, with significant differences being seen in pitch angle for two patients in the same direction as couch sag. Slight alterations were made in the position of the patients' knees and ankles in an attempt to reduce the pitch deviations. For all patients right lateral MV portal images and corresponding digitally reconstructedradiographs(DRR) were shown to the attending physician and a senior therapist with the question to determine if pitch greater than 3 degrees could be determined. Results: The deviation needed to create a pitch angle of 5 degrees in the RANDO phantom is significant so couch sag does not explain the deviations seen in a small population of the prostate patients imaged with CBCT. MV images were judged as showing insufficient information to determine pitch and Conclusion: Our clinical practice is that when any angular deviation over 3 degrees is observed in a patient set‐up the attending physician is called to decide how to proceed — treat or set‐up again. The phantom work demonstrated that a pitch variation in a patient set‐up cannot be attributed to couch sag and patient studies show that a few centimeters difference in knee separation lead to up to 3 degrees increase in pitch angle.