ESTRO 36 Abstract Book

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S263 ESTRO 36 2017
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difference in overall survival (OS), Quality of Life or use of
dexamethasone. These unexpected results were criticized
because OS was poorer (2 months) than the alleged
survival in common radiotherapy practice, suggesting
selection bias. Indeed, only 6% of included patients had a
favorable RPA class 1. Furthermore, patients with a more
favorable primary tumor such as breast cancer, could
perhaps benefit more from WBRT. Therefore, we
compared the QUARTZ data with survival after WBRT in
‘common radiotherapy practice’ from a large multicenter
retrospective cohort in the Netherlands.
Material and Methods
Survival data from all patients with brain metastases from
NSCLC or any type of breast cancer treated with WBRT
between 2000 and 2014 were analyzed. Patients were
treated in seven different institutes (both academic and
non-academic covering 33% of Dutch radiotherapy
practices). All patients were treated with 5 fractions of 4
Gy. Survival was calculated from the first day of
radiotherapy until the day of death or last follow-up. Date
of death was retrieved from the Dutch Municipal Personal
Records Database.
Results
Between 2000 and 2014, 3270 patients were identified,
2384 with brain metastases from NSCLC (73%) and 886
from primary breast cancer (27%). The median OS was 2.7
months for the NSCLC group and 3.8 months for the breast
cancer group (p<0.001). At time of analysis, 97% of all
patients was deceased. There was no difference between
academic and non-academic centres. No correlation
between the year of treatment and OS was found.
Conclusion
The survival of patients after WBRT for brain metastases
from NSCLC treated in Dutch ‘common radiotherapy
practice’ is practically the same as in patients treated in
the British QUARTZ study. Survival for patients with brain
metastases from breast cancer is only marginally better.
Our analysis supports the conclusion from the QUARTZ
study that there is insufficient evidence to consider WBRT
the standard of care for patients with multiple brain
metastases. We advocate more studies in this patient
population and recommend a more restrictive use of WBRT
in daily radiotherapy practice.
PV-0505 Association between the diagnosis-to-
treatment interval and overall survival in Taiwan OSCC
C.T. Liao 1, Y.W. Wen2, S.H. Ng 3, L.Y. Lee4, C.Y. Lin5,
H.M. Wang6, C.H. Lin7, T.C. Yen8
1 Chang Gung Memorial Hospital, Otorhinolaryngology-
Head and Neck Surgery, Taoyuan, Taiwan
2 Chang Gung University, Clinical Informatics and Medical
Statistics Research Center, Taoyuan, Taiwan
3 Chang Gung Memorial Hospital, Diagnostic Radiology,
Taoyuan, Taiwan
4 Chang Gung Memorial Hospital, Pathology, Taoyuan,
Taiwan
5 Chang Gung Memorial Hospital, Radiation Oncology,
Taoyuan, Taiwan
6 Chang Gung Memorial Hospital, Medical Oncology,
Taoyuan, Taiwan
7 Chang Gung Memorial Hospital, Plastic and
Reconstructive Surgery, Taoyuan, Taiwan
8 Chang Gung Memorial Hospital, Nuclear Medicine,
Taoyuan, Taiwan
Purpose or Objective
To investigate the association between the diagnosis-to-
treatment interval (DTI) and overall survival (OS) in
patients with oral cavity squamous cell carcinoma (OSCC).
Material and Methods
A total of 18,677 patients with first primary OSCC
identified in the Taiwanese Cancer Registry Database
between 2004 and 2010 were examined. The effect of DTI
on 5-year OS rates was investigated with multivariate Cox
regression analysis. After the identification of the optimal
cutoff for DTI based on the 5-year OS rates, DTI was
classified in the following 20-day groups: ≤20 days (57% of
the study patients), 21−45 days (34%), 46−90 days (6%),
and ≥91 days (3%). In additional exploratory analyses, DTI
was reclassified in the following 30-day interval groups:
≤30 days (81% of the study patients), 31−60 days (14%),
61−90 days (2%), and ≥91 days (3%).
Results
Multivariate analyses identified DTI (≤20 days vs. other
subgroups), sex (female vs. male), age (<65 vs. ≥65 years),
clinical stage (p-Stage I vs. p-Stage II, III, IV), and
treatment modality (initial surgery vs. initial non-surgery)
as independent prognostic factors for 5-year OS.
Compared with a DTI ≤20 days, the DTI categories ≥91 days
(hazard ratio [HR]: 1.28, P <0.001), 46−90 days (HR: 1.25,
P <0.001), and 21−45 days (HR: 1.07, P =0.007) were
independently associated with a higher risk of 5-year
mortality. Similar results were obtained for DTI ≤30 days
groups.
Conclusion
DTI is independently associated with 5-year OS in OSCC
patients. A DTI longer than 30 days or even 20 days may
potentially decrease survival.
PV-0506 Comparison of Clinical Behavior of Viral
Related Oropharyngeal and Nasopharyngeal Carcinoma
S.H. Huang1, J. Waldron2, J. Su3, S. Bratman 2, J. Kim2, A.
Bayley2, J. Ringash2, M. Giuliani2, A. Hope2, J. Cho 2, A.
Hansen4, R. Jang4, J. De Almeida5, B. Perez-Ordonez6, I.
Weinreb6, L. Tong2, W. Xu3, B. O'Sullivan2
1Princess Margaret Cancer Centre University Health
Network, 2B-Radiation Therapy, Toronto, Canada
2Princess Margaret Cancer Centre / University of
Toronto, Radiation Oncology, Toronto, Canada
3Princess Margaret Cancer Centre / University of
Toronto, Biostatistics, Toronto, Canada
4Princess Margaret Cancer Centre / University of
Toronto, Division of Medical Oncology, Toronto, Canada
5Princess Margaret Cancer Centre / University of
Toronto, Otolaryngology - Head & Neck Surgery,
Toronto, Canada
6Princess Margaret Cancer Centre / University of
Toronto, Pathology, Toronto, Canada
Purpose or Objective
To compare clinical behavior between viral related
oropharyngeal (OPC) and nasopharyngeal carcinoma (NPC)
at a western institution.
Material and Methods
We reviewed all newly diagnosed viral related OPC and
NPC treated with IMRT from 2005-2014. Viral etiology was
confirmed by p16 immunohistochemistry staining for HPV
and EBER in situ hybridization for EBV. Demographics, the
new HPV+ OPC specific UICC/AJCC TNM (ICON-S) and