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S300
ESTRO 36 2017
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to analyze clinical outcomes of patients treated with APBI
using multi-catheter interstitial brachytherapy (MIB-APBI)
stratified as per GEC-ESTRO and ASTRO guidelines for
patient selection and to correlate and analyze
appropriateness of these criteria for grouping patients to
predict clinical outcomes.
Material and Methods
Two hundred and forty two women underwent MIB-APBI
during July 2000- March 2013. Comparison of patient
selection criteria as per GEC-ESTRO and ASTRO guidelines
and their clinical outcomes was done on a prospectively
maintained database. Median age was 56 years, and
median pathological tumor size was 2 cm. ER, PR and HER
2 receptor positivity was seen 58.3%, 53.7% and 10.7%
patients respectively. Median number of planes was 3 and
median dose of APBI was 34 Gy. Kaplan Meier survival
analysis was done for local control (LC), disease free
survival (DFS), cause specific survival (CSS) and overall
survival (OS) after sub grouping as per both GEC-ESTRO
and ASTRO consensus guidelines.
Results
As per analyses with ASTRO consensus for patient
selection, our cohort consisted of 32 (13.2%), 143 (59.1%)
and 67(27.7%) patients belonging to suitable, cautionary
and unsuitable group, respectively. According to ESTRO
guidelines, 148(61.2%), 54(22.3%) and 40 (16.5%) patients
were categorized as low, intermediate and high risk group,
respectively. At a median follow up of 90 months, 7 year
overall LC, DFS, CSS and OS were 94.3%, 88%, 97% and
92.2% respectively for the entire group. There was no
statistically significant difference in the LC rates for both
ASTRO and ESTRO consensus groups (Table1 ). Thirty five
patients (14%) had disease failure out of which 12 patients
failed loco-regionally. The DFS (p=0.008), CSS (p=0.004)
and OS (p=0.007) rates were significantly correlated with
GEC-ESTRO consensus guidelines for patient selection
while none of our outcomes correlated with ASTRO
consensus guidelines. Variable cut off for age, tumor size
and weightage for presence of lymphovascular emboli in
these two guidelines mainly led to differences in the
distribution of risk stratification.
Conclusion
Patient selection as per both ESTRO and ASTRO consensus
guidelines do not have any impact on local control rates
for patients treated with APBI using interstitial
brachytherapy at long term follow up.
Symposium with Proffered Papers: Novel approaches in
poor tumour control sites
SP-0570 Radiopharmaceuticals in pancreatic cancer:
imaging and therapy
B. Cornelissen
1
1
University of Oxford- CRUK/MRC Oxford Institute for
Radiation Oncology, Radiopharmaceuticals and Molecular
Imaging Group, Oxford, United Kingdom
The potential of nuclear medicine imaging and therapy
will be discussed, with a focus on pancreatic cancer.
Pancreas cancer patients, most of which present with late
stage therapy-resistant pancreatic ductal adenocarcinoma
(PDAC), still have a very poor prognosis. A mere five
percent will survive for five years after being diagnosed.
Throughout all stages of pancreatic cancer, from
oncogenesis
to
treatment
follow-up,
using
radiopharmaceuticals with PET or SPECT imaging can have
significant impact on the management of pancreatic
cancer patients. An overview of PET and SPECT imaging
techniques will be presented, combining reports from the
literature with our own recent work. Some are already in
clinical use; some very novel agents have shown promise
in the preclinical stage. A small segment will be dedicated
to the use of therapeutic radiopharmaceuticals.
SP-0571 State of the art precision medicine for benign
and malignant brain tumours
G. Zadeh
1
1
University Health Network, Toronto, Canada
Abstract not received
SP-0572 Circulating tumour DNA, a new tool for the
early detection of poor outcome
F.C. Bidard
1
1
Institut Curie, Paris Cedex 05, France
Owing to the development of techniques that can detect
rare variants, circulating tumor DNA is now approved or
under investigation as a circulating tumor biomarker for
several applications in clinical oncology. ctDNA can be
used as “liquid biopsy”, surrogate to tissue biopsy (such as
in e.g. NSCLC for
EGFR
mutation detection), but is also
investigated as a dynamic marker of tumor load which may
be relevant for early detection of relapse or resistance to
therapy.
This presentation will focus on how ctDNA can be used to
detect early relapse/resistance, with examples
from studies initiated by our group:
-
TP53
mutation detection: results obtained in locally
advanced triple negative breast cancer (Riva
et al
, in
press) and ongoing "CirCA-01" study testing the early
detection of relapse and new tumor growth in BRCA01
mutation carriers (NCT02608346)
- HPV detection: results obtained in metastatic patients
and ongoing "CirCA-HPV" study testing the early detection
of relapse in cervix and anal canal cancers
-
ESR1
mutation detection: ongoing PADA-1 phase III trial
testing the utility of ESR1 mutation detection in
metastatic HR+ breast cancer
OC-0573 Development of hypoxia gene signatures as
biomarkers for treatment stratification
C. West
1
, L. Yang
1
, D. Roberts
1
, B. Bibby
1
, L. Forker
1
, S.
Haider
2
, F. Buffa
2
, A. Choudhury
3
1
The University of Manchester, Translational
Radiobiology Group, Manchester, United Kingdom
2
University of Oxford, Computational Biology and
Integrative Genomics, Oxford, United Kingdom
3
Christie Hospital NHS Trust, Clinical Oncology,
Manchester, United Kingdom
Purpose or Objective
A promising area for the development of biomarkers for
radiotherapy stratification is gene expression profiling to
predict benefit from hypoxia modification. Advantages of
RNA signatures versus other approaches are their good
repeatability and ability to minimise intra-tumour
variability. The rationale for focusing on hypoxia is that
interventions are available with proven benefit when
added to radiotherapy. This work investigated the
transferability of published signatures across tumour types
and the benefit of deriving tumour specific profiles.
Material and Methods
Work focused on bladder and prostate cancers and soft
tissue sarcoma. Published hypoxia signatures were tested
by analysing transcriptomic data from public databases.