Clinical evaluation of synthetic computed tomography methods in adaptive proton therapy of lung cancer patients

Comparing different boost concepts and beam configurations for proton therapy of pancreatic cancer

“…Adaptive planning is an increasing concern in particle therapy [35] . However, the optimal method has not fully been established [36] , [37] . Through recalculation on vCTs, it may be necessary to conduct re-planning at the beginning of treatment in some cases.…”

A review of the clinical introduction of 4D particle therapy research concepts

“…Mobile in-room CT was shown to provide adequate acquisition time, geometric accuracy and image quality as well as SPR conversion as a basis for offline replanning and contour propagation [119] , [120] , [121] . Individual PT offline adaptive procedures can also be triggered by 2D orthogonal X-ray or (synthetic) CBCT in combination with in-house and commercial software tools [122] , [123] , [124] , which are both also relevant image modalities for 4D motion management. Most offline adaptive planning in photon and particle therapy occurs ad-hoc based on anatomical changes noted on control imaging (e.g., CBCT or diagnostic CT scanner installed in or outside the treatment room) or clinical observations by medical doctors, radiation therapy technologists or the patient.…”

Evaluating synthetic computed tomography images for adaptive radiotherapy decision making in head and neck cancer

“…Three main techniques have been proposed in the literature to use CBCTs for dose calculations: Bulk density assignment, [8] , [10] , [11] , [12] , [13] , [14] Hounsfield Unit (HU) correction, [3] , [8] , [9] , [15] and Deformable Image Registration (DIR) to map HUs from fan-beam CTs to CBCT geometry [2] , [4] , [5] , [6] , [7] , [16] , [23] . Bulk density assignment of air, tissue and bone provides an approximation while avoiding issues associated with image artefacts and non-uniform scatter but does not provide accurate heterogeneity corrections for dose calculation.…”