ESTRO 36 Abstract Book

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S585 ESTRO 36
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Other = 23) were tested for HPV infection. Furthermore,
the clinical outcome for all tumor sides was examined with
uni and multivariate analysis. We analyzed p16 in all
tumor tissues as a surrogate marker for HPV infection with
immunohistochemistry. Moreover, risk factors such as
nicotine, alcohol abuse, location of the tumour, resection
margin of the tumour tissue, histology, lymph nodes
involvement, extracapsular spread, tumour stage, and the
treatment of the tumour (surgery, chemo and radiation
therapy) were examined for local tumour control and
overall survival for all patients.
Results
The prevalence of HPV infection in oropharynx-carcinoma
patients in Dusseldorf was 33%. Patients with HPV-positive
oropharyngeal carcinomas showed a tendency towards
longer survival time, (p = 0.76, HR: 2.42, 95% CI 0.91 -
6.44) compared to HPV-negative tumours. This association
was independent from alcohol and nicotine abuse. Other
tumour locations like larynx or hypopharynx carcinoma
showed no association between HPV infection and clinical
outcome. As expected the tumour stage in all tumour
locations was significant in the uni and multivariate
analysis for local control and overall survival.
Conclusion
The HPV infection in Dusseldorf was lower than
anticipated. Furthermore, in our study it seems that p 16
positive oropharyngeal carcinoma patients have a better
clinical outcome than p 16 negative patients. In this
patient group p 16 can be used as a prognostic biomarker.
This was independent from alcohol and nicotine abuse.
But for other tumor localizations we could not find a
better clinical outcome.
EP-1064 Does parotid sparing adaptive radiotherapy
(PSART) benefit patients? Interim results of PARITY
study
M. Arunsingh 1, C. Nallathambi 1, S. Prasath1, A.
Balakrishnan 1, R.K. Shrimali1, R. Achari1, I. Mallick1, S.
Chatterjee1
1 Tata Medical Center, Department of Radiation
Oncology, Kolkata, India
Purpose or Objective
Intensity Modulated Radiotherapy (IMRT) to the head and
neck cancer has been proven to reduce the incidence of
long-term xerostomia and thereby improve quality of life
(QOL) of survivors. However, it is also well known that
there are ongoing changes in the dose intended to the
parotids during radiotherapy often resulting in higher
parotid doses. Parotid sparing adaptive radiotherapy
(PSART) provides dosimetric corrections for such
unintended higher doses. Our study evaluates the clinical
benefits of PSART and also calculates the resource
intensiveness.
Material and Methods
Thirty-nine of the planned 90 patients of head and neck
cancer were screened if to at least one or both parotid
(index parotid/s) were receiving a mean dose (MD) of
between 25 to 30Gy and were recruited. The index parotid
was delineated on the verification images acquired on 14 th
and 19 th day and the MD was determined by overlaying the
fused verification image on the planned CT. Dosimetric
comparison was done using adaptive planning. If the MD
had increased by 2% of the initial intended dose, an
adaptive plan (AP) was attempted with an aim to reduce
MD by 2% without compromising PTV coverage; this plan
was then used to deliver the remaining treatment. The
time required and number of personnel involved during
each step was recorded and person hours (PH) were
calculated using the formula: (Minutes x Personnel
involved)/60. Xerostomia was assessed by a questionnaire
(XeQOLS) at baseline, at 3 and 9 months after completion
of treatment.
Results
Eighteen patients underwent radical radiotherapy with
remaining receiving adjuvant treatment. Thirty were
treated on Tomotherapy whilst others were treated on
Novalis Tx. The median increase in parotid dose was 1.1Gy
corresponding to a median reduction in the parotid volume
of 1.1cc. Twenty-three patients required an AP with
fifteen requiring it after the 14th day. An acceptable
adaptive plan, which met the criteria as described above,
was achieved for 19 of these 23 patients. A median of 7.5
fractions were delivered with the adaptive plans. Median
PH required for normal RT of a patient was 26PH while an
additional 14.34PH was required in those undergoing
PSART. All components of the XeQOLS (physical, pain,
social and personal) were worse at 3 months compared to
baseline and improved over time at 9 months in all
patients irrespective of whether they underwent PSART or
not (Figure 1). However, early data does not reveal any
significant difference in QOL for those who underwent
PSART. (Table 1)
XeQOLS
Score at 9
months
No PSART
Patients(Medi
an Score)
PSART
Patients(Medi
an Score)
Significanc
e, p(Mann-
Whitney)
Physical
Domain 1.00 2.00 0.64
Pain
Domain
1.00 2.00 0.64
Physiologic
al Domain 1.00
2.13 0.92
Social
Domain 0.67 2.17 0.64
Total Score 0.93 2.07 0.77
Conclusion
The results confirm that PSART, which is resource
intensive procedure, definitely reduces dose to the
parotid. However, it is still unclear if such plans improve
clinical QOL parameters further to the planned IMRT
plans. Completion of this study could give us further
confirmation on the clinical benefits of PSART.
EP-1065 Prediction of Dysphagia and Xerostomia
based on CT imaging features of HNSCC Patients
K. Pilz 1,2, S. Leger1, A. Zwanenburg 1, C. Richter1,2,3,4, M.
Krause 1,2,3,4,5, M. Baumann 1,2,3,4,5, S. Löck1,2,4, E.G.C.
Troost1,2,3,4,5
1OncoRay - National Center for Radiation Research in
Oncology, Faculty of Medicine and University Hospital
Carl Gustav Carus- Technische Universität Dresden-
Helmholtz-Zentrum Dresden – Rossendorf, Dresden,
Germany
2Department of Radiation Oncology, Faculty of Medicine
and University Hospital Carl Gustav Carus- Technische
Universität Dresden, Dresden, Germany
3German Cancer Research Center DKFZ, Germany and
German Cancer Consortium DKTK partner site Dresden,
Dresden, Germany
4Helmholtz-Zentrum Dresden – Rossendorf, Institute of
Radiooncology, Dresden, Germany