ESTRO 36 Abstract Book

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S591 ESTRO 36
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a decrease in the cellularity in the tumour & tumour
response. Thus, a rising ADC value during treatment versus
Pretreatment ADC values may be used to predict
outcomes.
The aim of this study was to investigate the role of
diffusion weighted MRI derived parameters like ADC, as an
imaging biomarker, to predict response to RT in locally
advanced squamous cell carcinoma of the larynx and
hypopharynx.
Material and Methods
From May 2014 to August 2015, 19 patients with locally
advanced laryngeal & hypopharyngeal malignancies,
treated with organ preservation intent with concurrent
radiotherapy with Cisplatin (n=14), radiotherapy with
Nimotuzumab (n=2) and radical radiotherapy (n=3) were
recruited. The patients were all male with predominantly
T3 stage. They were assessed for treatment response with
dWMRI at baseline, first week, fourth week during RT and
at the time of first response assessment at 6 to 8 weeks
after RT. The ADC values were compared at different time
points and correlated with the treatment response.
Results
All the 19 patients in the study showed an increasing trend
in the ADC values over the chosen 4 different time points.
It was observed that an abrupt rise from the pretreatment
ADC to the first week ADC was characteristic of complete
response while a gradual rise of ADC over the different
points suggested a partial treatment response. The
patients who responded to chemoradiation therapy had a
higher pretreatment ADC than patients with partial
response. At the last follow up, 12 patients were disease
free, while 5 patients developed recurrence. Four patients
with recurrence had shown a partial response while only
one had exhibited a complete response during RT. One
patient died during treatment of aspiration pneumonia
while undergoing CRT & another did not follow up after
completion of treatment.
Conclusion
This study suggests that an abrupt rise in the ADC value in
the tumour after one week of treatment may predict
complete response & long term tumour control. However
this finding needs to be investigated in a larger cohort of
patients over a longer follow up before dWMRI can be
utilised in clinical practice.
EP-1076 toxicity of concomitant chemotherapy and
IMRT in locally advanced OPSCC: sequential vs SIB
technique
G. Abate1, F. De Felice1, A. Galdieri1, G. Gravina2, F.
Marampon 3, D. Musio1 , V. Tombolini1
1 Policlinico Umberto I- “Sapienza” University of Rome,
radiotherapy, Roma, Italy
2 University of L'Aquila, Department of Biotechnological
and Applied Clinical Sciences- Laboratory of
Radiobiology, L'Aquila, Italy
3 University of L’Aquila-, Department of Biotechnological
and Applied Clinical Sciences- Laboratory of
Radiobiology, L'Aquila, Italy
Purpose or Objective
Concurrent radiochemotherapy is the standard of care for
locally advanced oropharingeal squamous cell carcinoma
(OPSCC) patients. Due to a substantial locoregional
recurrence rate especially in human papilloma virus (HPV)
negative disease, an improvement in treatment outcome
is desirable.
Treatment intensification with radiation dose escalation
could represent a valid option by applying accelerated
radiotherapy with higher dose for fraction and non-
uniform dose distribution with simultaneous integrated
boost (SIB). Even if radiobiological and clinical data
suggest that accelerated fractionation with higher dose
per fraction given in GTV may produce better locoregional
control, a higher toxicity is expected especially with
concomitant platinum 100 mg/mq based chemotherapy.
A comparison between sequential IMRT (S-IMRT) and SIB-
IMRT was planned. The aim was to evaluate the
tolerability and safety of SIB regimen in HPV negative
patients with locally advanced OPSCC
Material and Methods
Patients with histologically proven HPV negative OPSCC,
staged T3-4 with or without involved lymph nodes at
diagnosis, who received primary CRT, were included. S-
IMRT was defined as radiotherapy equivalent to 70 Gy (2
Gy/fraction). SIB-IMRT was administered to a total dose
of 67.5 Gy (2.25 Gy/fraction) to high dose volume and
60 (2 Gy/fraction) and 54 Gy (1.8 Gy/fraction) to high risk
and low risk volumesrespectively..
Fusion CT–MR imaging with a deformable registration
software was performed to accurately localize target
volumes and organs at risk.
Concomitant cisplatin (100mg/m2 on day 1 and day 22 day
of treatment) was used.
Results
A total of 46 patients (31 males, 15 females) with
a median age of 64 years (range 41-75) were examined
between February 2009 and March 2016. All patients
completed the programmed CRT treatment. No patients
suspended planned chemotherapy and all patients
received the IMRT prescribed total dose. No severe life
risking complications occurred and no significant
differences between S-IMRT and SIB-IMRT were observed
in term of major acute toxicities. Details are shown in
table 1
Conclusion
Our data shows that IMRT-SIB with 2.25 Gy/fraction with
concurrent platinum-100- based chemotherapy is a safe
treatment approach without increasing toxicities. This
regimen is therefore acceptable for the therapy of locally
advanced oropharyngeal cancer and patients with poor
prognosis as HPV negative OPSCC could benefit from it. A
longer follow up is needed to fully evaluate late toxicity
and survival.
EP-1077 Predictive modeling for radiation-induced
acute dysphagia in head and neck cancer patients.
D. Alterio1, M. Gerardi1, L. Cella 2, V. D'Avino2, G. Palma2,
D. Ciardo1, E. Rondi3, A. Ferrari1, M. Muto4, R. Spoto4, R.
Pacelli 5, R. Orecchia6, B. Jereczek7
1European Institute of Oncology, Radiation Oncology,
Milan, Italy
2National Council of Research, Biostructures and
Bioimaging, Naples, Italy
3European Institute of Oncology, Medical Physics, Milan,
Italy
4European Institute of Oncology - University of Milan,
Radiation Oncology -Oncology and Hemato-oncology,
Milan, Italy
5Federico II- University school of Medicine, Advanced
Biomedical Sciences, Naples, Italy
6European Institute of Oncology - University of Milan,
Medical Imaging and Radiation Sciences - Oncology and
Hemato-oncology, Milan, Italy
7European Institute of Oncology - University of Milan,