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@ARTICLE{Hofmann:301572,
author = {T. Hofmann and M. Sammer and N. Kohlhase and D. Eftimova
and F. Ehret$^*$ and A. Santacroce and A. Muacevic and C.
Fürweger},
title = {{T}reatment {P}lan {C}omparison {B}etween
{S}elf-{S}hielding {G}yroscopic {R}adiosurgery and {R}obotic
{R}adiosurgery.},
journal = {Cureus},
volume = {17},
number = {4},
issn = {2168-8184},
address = {Palo Alto, Calif.},
publisher = {Cureus, Inc.},
reportid = {DKFZ-2025-01080},
pages = {e82990},
year = {2025},
abstract = {Stereotactic radiosurgery with established systems like the
Gamma Knife and CyberKnife (Accuray Inc., Madison, WI, USA)
is a well-characterized treatment concept. The novel ZAP-X®
platform (ZAP Surgical Systems Inc., San Carlos, CA, USA)
for vault-free, self-shielding gyroscopic radiosurgery (GRS)
promises high plan quality due to advantageous beam
properties. However, the clinically usable workspace in GRS
is reduced due to potential collisions with a spacious
headrest. A novel 'conformal' headrest was introduced to GRS
in December 2023 to remedy this, using narrower masks to
minimize collision zones and maximize the usable solid
angle. This study analyzes the GRS plan quality for 30
simple and complex cases, comparing GRS plans with the old
and new headrests to robotic radiosurgery (RRS) as an
established reference platform. The GRS system consists of a
3 MV linear accelerator mounted on coupled gimbals for
non-coplanar beam delivery, a collimator wheel for circular
beam shaping, and a kV image guidance system. The RRS system
is a full-body treatment platform with a 6 MV linear
accelerator on a robotic arm for non-coplanar,
non-isocentric beam delivery. A total of 30 clinical
single-fraction plans treated with the GRS system prior to
the headrest update is selected. Clinical GRS treatment
plans are created by manually placing isocenters within the
target volume and using an inverse optimization algorithm.
GRS plans are reoptimized using the new software and
headrest (further referred to as GRS*) for comparison. RRS
plans are generated using circular apertures and the VOLO™
optimization technique. Treatment plans from the GRS, GRS*,
and RRS platforms are compared with respect to quality
metrics, number of beams, total monitor units (MU), and
expected treatment time. The updated GRS* plans show a
significantly better new conformity index (nCI) and gradient
index (GI) than the clinical GRS plans. The volume of the
brainstem receiving 8 Gy or more is significantly reduced
with the GRS* platform. The number of beams, total MU, and
expected treatment time increase significantly with the new
GRS* treatment planning system. Compared to GRS* plans, the
nCI of RRS plans is better, but the GI is worse. The total
number of beams and MU were significantly lower with the RRS
platform, while the expected treatment times were
equivalent. The introduction of the new headrest design in
the GRS* system has led to a notable improvement in the
treatment plans of GRS. As a trade-off for the overall
improvement in dosimetric quality, the number of beams and
the expected treatment time increase. RRS and GRS* systems
now exhibit equivalent plan quality, with a trend of the
GRS* toward sharper dose gradients but lower conformity,
attributed to the specialized delivery design.},
keywords = {cyberknife (Other) / dosimetric evaluation (Other) /
gyroscopic radiosurgery (Other) / robotic radiosurgery
(Other) / single-fraction radiotherapy (Other) /
stereotactic radiosurgery (Other) / treatment plan
comparison (Other) / zap-x (Other)},
cin = {BE01},
ddc = {610},
cid = {I:(DE-He78)BE01-20160331},
pnm = {899 - ohne Topic (POF4-899)},
pid = {G:(DE-HGF)POF4-899},
typ = {PUB:(DE-HGF)16},
pubmed = {pmid:40416107},
pmc = {pmc:PMC12103933},
doi = {10.7759/cureus.82990},
url = {https://inrepo02.dkfz.de/record/301572},
}