ESTRO 36 Abstract Book

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S982 ESTRO 36 2017
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Seventy-four H&N cancer patients were randomized to
three different types of immobilized pillow: 28 for routine
pillow (Silver Headrests, CIVCO, medical solution), 23 for
home-made customized alpha cradle pillow and 23 for
Moldcare pillow. On–board images (OBIs) during the first
23 treatment fractions were registered and fused with the
digitally reconstructed radiographs (DRRs). The angular
displacement of first to fifth cervical vertebrae were
recorded.
Results
There was no significant difference of the C1-C5 angular
displacement in three different types of pillows with 2.79
± 1.72 degrees in the routine pillow group, 2.54±1.68
degrees in home-made customized alpha cradle pillow
group, 3.17±2.32 degrees in Moldcare pillow group.
Conclusion
The patients in home-made customized alpha cradle
pillow group had smallest neck angular displacement.
However there were no significant difference and the
reproducibilities of all three pillow types were good.
Further evaluation about the clinical use of customized
pillows is needed.
EP-1817 Breast set-up: Assessing two immobilization
systems
V. Lancellotta1, A.M. Tini1, S. Saccia 1, S. Trinari1, S.
Dazzini1 , G. Verzini1, N. Mearelli 1, V. Bini1, A. Cavalli1, E.
Perrucci1 , C. Aristei1
1 Ospedale Santa Maria della Misericordia, Radiation
Oncology, Perugia, Italy
Purpose or Objective
In breast cancer radiotherapy, an optimal patient set-
up is essential to reduce the gap between personalized
treatment planning and uncertainties in irradiation
administration. In fact, several factors worsen
reproducibility, with the most important being poor
patient immobilization and lack of a quality assurance
system at all steps of the radiotherapy procedure.The aim
of our study was to investigate whether the breast board
or the arm shuttle provided the best support for a correct
patient set-up during irradiation to for breast cancer.
Material and Methods
Between November 2012 and December 2014, 28 women,
median age 62 years (range 34-88) underwent RT to
breast/chest wall plus level III and IV lymph nodes (2 Gy
single dose in 25 fractions for a total dose of 50 Gy ). Each
patient was placed in the same position i.e. supine with
arms raised. Thirteen were supported by a non-inclined
breast board and 15 by an arm shuttle. The breast board
has several adjustable features to allow for the
manipulation of patients arms, wrists, head and shoulders.
Furthermore, the presence of head and neck supports in
different heights and contours to attain the desired head
angulation and/or neck position. Multiple head rest
positions in the arm-shuttle provided flexible positions for
the head and arms without different heights and contours
to attain the desired head angulation and/or neck
position. Helical tomotherapy was used to treat all
patients. HT planning parameters were: 5 cm field width
(FW), 0.287 pitch, and 2.7 - 3 modulation factor
(MF). Daily use of CT-MV image-guided RT corrected set-
up errors. For each patient, we reported the pitch, yaw
and roll values and the x, y and z axis displacements.
Statistical analysis used the Mann-Witney test.
Results
Table 1 reports pitch, yaw and roll averages and the
average displacement on the X, Y and Z axes with the
breast board and arm shuttle as well as the significant
differences which emerged from the statistical analysis.
Conclusion
Compared with the arm shuttle, the breast board provided
a better set-up in breast cancer patients undergoing
HT irradiation to the breast/chest wall plus draining
nodes .Since these results are linked to breast board
configuration , its use is now standard in our RT Centre.
Electronic Poster: RTT track: Imaging acquisition and
registration, OAR and target definition
EP-1818 The rate of a doctor’s progress in a learning
curve in delineation of hippocampus
M. Konopka-Filippow1,2, E. Sierko 1,2,3, D. Hempel1, R.
Maksim1, T. Filipowski1, E. Rożkowska1, S. Jelski4, B.
Kasprowicz 4, E. Karbowska4, N. Samołyk1, M.Z.
Wojtukiewicz3
1Comprehensive Cancer Center in Bialystok- Poland,
Department of Radiotherapy, Bialystok, Poland
2Medical University of Bialystok- Poland, Department of
Oncology, Bialystok, Poland
3Comprehensive Cancer Center in Bialystok- Poland,
Department of Clinical Oncology, Bialystok, Poland
4Comprehensive Cancer Center in Bialystok- Poland,
Department of Radiology, Bialystok, Poland
Purpose or Objective
Brain radiotherapy (RT) is associated with damage of
neural progenitor cells situated in subgranular zone of the
hippocampus, which causes neurocognitive decline.
Sparing hippocampus during cranial RT could avoid this
complication in the group of cancer patients and improve
their quality of life (QoL).
Accurate hippocampus contouring is an essential for
appropriate brain RT planning with sparing this structure
and its an prerequisite of quality assurance in RT.
Material and Methods
Ten doctors (7 radiation oncologist and 3 radiologists)
delineated left and right hippocampus (LH and RH,
respectively) on the 10 patient’s virtual axial images of CT
brain fusion with the T1 sequence of MRI (1mm) according
to the RTOG 0933 atlas recommendations. Two hundred
contours of hippocampus were achieved. Deviations in the
spatial localization of the structure were described in the
three directions: right-left (X), cranio-caudal (Y), forward-
backward (Z) in relation to the most adequate contoured
hippocampus according to RTOG atlas references, which
was delineated by an experienced radiation oncologist.
Results
Variability of hippocampus body contouring concerned:
the spatial localization, shape, volume and the dimension
of the hippocampus in the X, Y and Z axes. The largest
differences were noted in the first three contoured cases:
the Z-axis deviation exceeded 5 mm in more than half of
hippocampus contours and hippocampal volume were
larger than in later defined seven cases. The volume of LH
in more than half hippocampus contours was slightly
bigger than the RH (1.9 cm3 vs. 1.8 cm 3). Most differences
in contouring of hippocampus ware observed in the area
of posterior horn of the lateral ventricle. Contrary, a large
number of hippocampal outlines overlapped with each
other near brainstem and anterior horn of the lateral
ventricle. The average dimension of the hippocampus
were 1.7 cm and 0.9 cm in the Z and X axes, respectively.
Conclusion
The proper contouring of hippocampus is difficult for the
beginner’s physicians. The training in delineating this
organ at risk under the supervision of experienced
radiation oncologist is strongly needed to achieve optimal
results in hippocampus sparing procedure, which in
consequence would result in improving QoL of the
patients.