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6th ICHNO
page 55
6
th
ICHNO Conference
International Conference on innovative approaches in Head and Neck Oncology
16 – 18 March 2017
Barcelona, Spain
__________________________________________________________________________________________
markers in bioimaging may allow individualization of
treatment by dose painting and adaptive radiotherapy.
PO-114 Alterations in tumour hypoxia in serial F-
MISO/PET-CT during chemoradiation in HNSCC
H. Bunea
1
, A. Bunea
1
, L. Majerus
1
, C. Stoykow
2
, M. Mix
2
,
A.L. Grosu
1
1
Universitatsklinik Freiburg, Klinik für
Strahlenheilkunde, Freiburg, Germany
2
Universitatsklinik Freiburg, Klinik für Nuklearmedizin,
Freiburg, Germany
Purpose or Objective
Tumor hypoxia, a common feature of locally advanced
head and neck cancer (HNSCC), is associated with higher
malignancy and increased radioresistance. The decrease
of tumor hypoxia during fractionated radiation treatment
is assumed to be decisive for treatment success. [18F]-
Fluoro-Misonidazole PET (F-MISO-PET) allows noninvasive
assessment of hypoxia during treatment. The purpose of
the present study was to noninvasively assess the time
course of tumor hypoxia.
Material and Methods
A prospective serial imaging study was conducted in
patients undergoing definitive chemoradiation (dRCTx,
total dose 70Gy) for locally advanced HNSCC,
accompanied by cisplatin in weeks 1, 4 and 7. Tumor
hypoxia was assessed by F-MISO-PET by static scans
acquired 2.5 h p.i. Tumor volumes were determined for
FDG PET/CT scans and the coregistered F-MISO/CT scans.
At baseline MRI, FDG-PET/CT and F-MISO-PET were
acquired (week 0). Additional F-MISO-PET/CT scans were
acquired in treatment weeks 2 and 5. Normal sample
distribution was confirmed with Shapiro-Wilk test.
Unpaired
t-test
analysis
of
the
mean
SUVmax(tumor)/SUVmean(muscle) ratios of F-MISO-PET in
weeks 0, 2 and 5 were performed. Significance-level was
defined as p<0.005.
Results
Between 2012 and 2014 18 patients (16 men, two women,
mean age 60 years), treated for HNSCC with dRCTx were
included. All received a total dose of 70 Gy in 35 fractions.
Concomitant cisplatin chemotherapy was administered in
weeks 1, 4 and 7. 14 patients had all F-MISO-PET scans,
while 4 had two F-MISO-PET scans (week 0, 5). The mean
follow-up time was 14.6 months (range: 4 - 28 months).
Mean SUVmax(tumor)/SUVmean(muscle) in weeks 0, 2 and
5 were 1.9 (n=18, SD ± 0.1), 1.5 (n=14, SD ± 0.1) and 1.2
(n=18, SD ± 0.1), respectively. Unpaired t-test for
SUVmax(tumor)/SUVmean(muscle) between week 0 and 5
was performed, showing a singnificant decrease
(p<0.0001). Between weeks 0 and 2 (p=0.0346) and
between weeks 2 and 5 the decrease again was highly
significant (p=0.0113). In two patients no residual hypoxia
was measured in week two, resulting in
SUVmax(tumor)/SUVmean(muscle) =1.0. In week 5 this
was found in seven patients. In two patients hypoxia had
increased in week 2 but decreased in week 5 compared to
pre-treatment measurements. In one patient hypoxia had
increased by the end of treatment.
Conclusion
Differences in hypoxia between weeks 0-2, 2-5 and 0- 5,
respectively, show statistical significance. This is crucial
in the process of re-oxygenation. As concluded in previous
works, change of treatment strategy, e.g. by means of
dose escalation might be most efficient early during
treatment. However further analysis, with more patients
and correlation to disease-free and overall-survival are
needed.
PO-115
A [18F] FDG-PET adaptive thresholding
algorithm delineation of RT tumour volumes of head
and neck cancer
L. Deantonio
1
, M. Paolini
1
, L. Vigna
2
, G. Loi
2
, L. Masini
1
,
G. Sacchetti
3
, R. Matheoud
2
, M. Brambilla
2
, M. Krengli
1
1
University Hospital Maggiore della Carità,
Radiotherapy, Novara, Italy
2
University Hospital Maggiore della Carità, Medical
Physics, Novara, Italy
3
University Hospital Maggiore della Carità, Nuclear
Medicine, Novara, Italy
Purpose or Objective
The aim of this study was to evaluate a [18F] FDG-PET
adaptive thresholding algorithm (ATA) for the delineation
of the biological tumour volume for the radiotherapy (RT)
treatment planning of head and neck cancer patients.
Material and Methods
Thirty-eight patients, who underwent exclusive intensity
modulated RT with simultaneous integrated boost (IMRT-
SIB) for head-and-neck squamous cell carcinoma (3 oral
cavity, 9 nasopharynx, 19 oropharynx, 6 hypopharynx, and
1 larynx cancer) were included in the present study.
Thirty-five/38 patients presented a locally advanced
disease, and 33/38 received a concomitant
chemoradiotherapy treatment. For all patients [18F] FDG-
PET/CT was performed in treatment position with the
customized thermoplastic mask. Two radiation oncologists
defined the primary gross tumour volumes (GTV) using the
ATA implemented on the iTaRT workstation (Tecnologie
Avanzate, Italy). The algorithm used specific calibration
curves that depended on the lesion-to-background ratio
(LB ratio) and on the amplitude of reconstruction
smoothing filter (FWH). The reproducibility of ATA in
volume estimation was determined evaluating the volume
overlap of multiple segmentation of the same lesions by
different operators. Each primary tumour volume
segmented by the ATA (GTV
ATA
) was compared to the GTVs
contoured on two different sets. In the first, the two
radiation oncologist manually draw the standard GTV
(GTV
ST
) based on clinical information, CT simulation, and
magnetic resonance imaging (MRI); in the second, a fixed
image intensity threshold method (40% of maximum
intensity) of [18F] FDG-PET standardized uptake value was
used to define the GTV
40%SUV
.
Results
The ATA previously performed only in a phantom study
generate a GTV in all head and neck patients. The mean
value of volumes based on the three different methods are
reported in Table 1.
The GTV
ATA
was smaller than the GTV
ST
(17 vs 21 cc); the
similarity coefficient (DICE) was 0.7 (Sensibility 66%,
specificity 85%). GTV
ATA
is a part of the GTV
ST
.
The GTV
ATA
was bigger than the GTV
40%SUV
(17 vs 15 cc), the
DICE was 0.2.
Conclusion
The proposed ATA resulted robust and reproducible in a
clinical context. The ATA used in the present study allows
the delineation of a BTV for dose escalation. A IMRT-SIB
with a boost based on GTV
ATA
is feasible.
PO-116 Potential applications of spectral CT imaging in
patients with head and neck squamous cell carcinoma
B. Peltenburg
1
, J.W. Dankbaar
2
, M.J. Willemink
2
, R. De
Bree
3
, T. Leiner
2
1
UMC Utrecht, Radiation Oncology, Utrecht, The
Netherlands
2
UMC Utrecht, Radiology, Utrecht, The Netherlands
3
UMC Utrecht, Head and Neck Surgical Oncology,
Utrecht, The Netherlands