TY  - JOUR
AU  - Qubala, Abdallah
AU  - Karger, Christian P
AU  - Horn, Julian
AU  - Winter, Marcus
AU  - Ellerbrock, Malte
AU  - Jäkel, Oliver
AU  - Henkner, Katrin
TI  - Patient-specific quality assurance at the Heidelberg Ion Beam Therapy Center: 10 years experience in treatment plan verification.
JO  - Medical physics
VL  - 53
IS  - 1
SN  - 0094-2405
CY  - Hoboken, NJ
PB  - Wiley
M1  - DKFZ-2025-03063
SP  - e70237
PY  - 2026
AB  - To ensure accurate, safe, and reproducible patient treatments, it is essential to have precise knowledge and a solid understanding of patient-specific quality assurance (PSQA). For many years, the delivery of doses to all patients has been verified using dosimetric measurements. However, these measurements require substantial work, and the reasons for the occasional deviations are unclear. For these reasons, alternative methods such as independent dose calculations (IDCs) and analysis of beam-monitor log files are increasingly discussed in the particle therapy community. Nevertheless, before replacing dose-verification measurements with other methods, existing measurement data should be thoroughly analyzed to determine what can be learned from them and how they compare with potential alternatives. These alternative methods are mentioned in this work only to provide context and to outline possible directions for future studies.To evaluate the dosimetric accuracy and efficiency of PSQA using a water phantom (WP) over a 10-year period at the Heidelberg Ion Beam Therapy Center (HIT).Between 2016 and 2025, 23014 treatment fields with protons, carbon, or helium ions were verified using a WP equipped with 24 pinpoint ionization chambers. The patient treatment plans were recalculated in the water phantom geometry and compared to measured absolute doses. The data were categorized by treatment room, ion species, treatment planning systems (TPS), range shifter (RaShi) use, indication, depth, and target volume, excluding measurements with human errors. Statistical analysis compared measured and calculated doses, focusing on mean, maximum, and minimum dose deviations. Furthermore, the workflow efficiency was assessed based on the beam time required for dosimetric verification, as well as the total time needed for preparation and analysis.Mean dose deviations were in general slightly negative (t-test, p < 0.01), within ±1 
KW  - Quality Assurance, Health Care
KW  - Humans
KW  - Radiotherapy Planning, Computer-Assisted: methods
KW  - Heavy Ion Radiotherapy
KW  - Time Factors
KW  - Radiotherapy Dosage
KW  - Phantoms, Imaging
KW  - Radiometry
KW  - dose measurements (Other)
KW  - dose verification (Other)
KW  - helium and carbon ion beam therapy (Other)
KW  - particle therapy (Other)
KW  - patient specific quality assurance (Other)
KW  - proton (Other)
KW  - spot scanning (Other)
KW  - water phantom (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:41452343
C2  - pmc:PMC12742551
DO  - DOI:10.1002/mp.70237
UR  - https://inrepo02.dkfz.de/record/307464
ER  -