Publications by authors named "Alexander Gemmel"
We propose a patient-specific planning target volume (PTV) to deal with interfractional variations, and test its feasibility in a retrospective treatment-planning study. Instead of using one planning image only, multiple scans are taken on different days. The target and organs at risk (OARs) are delineated on each images.
View Article and Find Full Text PDFArticle Synopsis
- The proposed method enables quick generation of treatment plans in ion beam therapy by utilizing a depth-modulation curve (DMC) derived from existing reference plans.
- The method was tested on prostate patients and digital phantoms, demonstrating the ability to produce plans with 97% dose coverage and no overdosage within one minute on a standard PC.
- Overall, the technique shows promise for incorporating plan adaptations both during treatment and in pre-treatment planning, while maintaining safety for surrounding organs.
Background: Scanned ion beam therapy of intra-fractionally moving tumors requires motion mitigation. GSI proposed beam tracking and performed several experimental studies to analyse the dosimetric precision of the system for scanned carbon beams.
Methods: A beam tracking system has been developed and integrated in the scanned carbon ion beam therapy unit at GSI.
The technical performance of an integrated three-dimensional carbon ion pencil beam tracking system that was developed at GSI was investigated in phantom studies. Aim of the beam tracking system is to accurately treat tumours that are subject to respiratory motion with scanned ion beams. The current system provides real-time control of ion pencil beams to track a moving target laterally using the scanning magnets and longitudinally with a dedicated range shifter.
View Article and Find Full Text PDFPurpose: To demonstrate mitigation of the interplay effects of scanned particle beams and residual target motion within a gating window by increased overlap of pencil beams.
Methods And Materials: Lateral overlap was increased by increasing the pencil beam widths or by decreasing the distance between the pencil beams (scan grid). Longitudinal overlap was increased by reducing the distance between iso-range slices.