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In this paper we review the physics opportunities at linear \\(e^+e^-\\) colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the various accelerator technologies available or under development and, for the first time, discuss how a facility first equipped with a technology mature today could be upgraded with technologies of tomorrow to reach much higher energies and/or luminosities. In addition, we will discuss detectors and alternative collider modes, as well as opportunities for beyond-collider experiments and R\\&D facilities as part of a linear collider facility (LCF). The material of this paper will support all plans for \\(e^+e^-\\) linear colliders and additional opportunities they offer, independently of technology choice or proposed site, as well as R\\&D for advanced accelerator technologies. This joint perspective on the physics goals, early technologies and upgrade strategies has been developed by the LCVision team based on an initial discussion at LCWS2024 in Tokyo and a follow-up at the LCVision Community Event at CERN in January 2025. It heavily builds on decades of achievements of the global linear collider community, in particular in the context of CLIC and ILC.

Purpose This study quantitatively evaluates bladder changes and their dosimetric impact during the on‐couch adaptive process on a commercial CBCT‐based online adaptive radiotherapy (CT‐gART) platform. Methods Data from 183 fractions of ten patients receiving online ART for pelvic cancers were analyzed retrospectively. Bladder contours were automatically generated and revised by an expert for each pair of planning and verification CBCTs. Bladder shape changes were assessed using geometric and boundary distance metrics. A deformable image registration (DIR) workflow was implemented to obtain spatial motion characteristics, validated by the dice similarity coefficient between bladder contours. Dosimetric parameters were quantified by warping ’intended’ dose distributions to the verification CBCT anatomy using DIR to evaluate coverage and OAR objectives. Results Bladder volume changed noticeably during the on‐couch adaptation process (19.7 ± 3.3 min). Day‐to‐day bladder expansion showed an average increase of 3.4 cc/min ± 1.5 cc/min for the full bladder and 0.8 cc/min ± 0.3 cc/min for empty bladder protocols. Deformation occurred mainly in the superior region and was more pronounced for the full bladder protocol. Displacements over 5 mm in cranial‐caudal and anterior‐posterior directions averaged 16% and 5% of the volume for full bladders and 5% and 4% for empty bladders, respectively. CTV coverage (V100%) was maintained when the bladder was the target, but PTV V95% was reduced by an average of 7%. For non‐bladder treatments, bladder constraints increased slightly for supine subjects (0.5 Gy/fx), with prone subjects almost unaffected. Conclusions A framework using auto‐segmentation and DIR was developed to evaluate the intra‐fractional motion of the bladder during CTgART. Results suggest that reducing the isotropic PTV margin to less than 7 mm may be feasible for oART, allowing patient‐specific anisotropic margins while maintaining the quality of the adaptive plan.