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ESTRO 36
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The non-parametric Wilcoxon and Spearman tests were
used to estimate the relationships. The data were
analyzed using SPSS version 22.
Results
The gross tumor volume (GTV-t) was greater by FDG-
PET/CT-simulation but differences were not statistically
significant. However, the gross node volume (GTV-n) and
the length of the esophageal tumor were greater by FDG-
PET/CT-simulation and these differences were
statistically significant (
Table 1
).
The analyzed of DSC showed a great similarity of GTV-t:
0.71 (0.13). A very low DSC was observed in GTV-n: 0.08
(0.47). Data are expressed as median and inter-quantile
range. Values greater than 0.7 are often regarded as an
excellent agreement.
Correlations between volume sizes for PET/CT and CT
were determined using a correlation coefficient. There
was a very high correlation (
0.82
) between CT and FDG-
PET/CT simulation (p=0.002) in the GTV-tumor volumes.
However, this correlation was very low (0.58) in the GTV-
node (p=0.01) and length of the esophageal tumor (0.67,
p=0.001).
Conclusion
Our study shows that the volume definition by FDG-
PET/CT and CT simulation in esophageal cancer differs,
especially with respect to GTV-node volume and tumor
length. FDG-PET/CT appears to have an impact on
treatment planning and management of esophageal
carcinoma.
Proffered Papers: Prostate 2
OC-0269 Single Dose Compared to Fractionated High-
Dose Rate Brachytherapy for Localised Prostate Cancer
P. Hoskin
1
, A. Rojas
1
, P. Ostler
1
, R. Hughes
1
, R. Alonzi
1
, G.
Lowe
1
1
Mount Vernon Hospital, Cancer Centre, Northwood
Middlesex, United Kingdom
Purpose or Objective
To evaluate late toxicity and freedom from biochemical
relapse (FFbR) after high-dose-rate brachytherapy (HDR-
BT) in localised prostate cancer.
Material and Methods
HDR-BT delivering 1 x 19 Gy, 1 x 20 Gy, 2 x 13 Gy, 3 x 10.5
Gy, 4 x 8.5 Gy and 4 x 9 Gy was given to patients with
predominantly intermediate or high-risk prostate cancer.
All patients were staged with at least pelvic MR and
isotope bone scan to exclude metastatic disease.
Transperineal-transrectal ultrasound guided implantation
was followed by MR based CTV definition following the
GEC ESTRO guidelines. Biochemical relapse was assessed
using the Phœnix definition (PSA nadir plus 2 µg/L). Late
urinary (GU) and gastrointestinal (GI) were assessed using
the RTOG and the International Prostate Symptom Score
(IPSS). Patients were evaluated prospectively from 6
months after implant and bi-annually thereafter.
Pearson’s Chi-square was used to test for significance
between prevalence of GI, GU catheter use and IPSS
events. Estimates of freedom from biochemical relapse,
disease-free survival (DFS) and overall survival (OS) and of
GI, GU and IPSS toxicity were calculated using the Kaplan-
Meier (K-M) method and the log-rank test to test for
significance.
Results
Median age is 69 (19, 26 and 31.5 Gy), 70 (20 Gy), 68 (34
Gy) and 67 years (36 Gy). For 19, 20, 26, 31.5, 34 and 36
Gy median PSA was 8.2, 10.7, 11, 12.4 11.1 and 10.5 µg/l,
Gleason Scores ≥ 8 were 4%, 31%, 11%, 6%, 11% and 13%,
proportion with T
3
disease was seen in 29%, 35%, 32%, 36%,
43% and 35% of patients, and median follow-up 54, 48, 62,
107, 129 and 121 months, respectively. Neo-adjuvant and
adjuvant androgen deprivation treatment was given to 76%
of all patients; intermediate risk patients were treated for
6 months and high risk for up to 3 years. K-M estimates of
FFbR, DFS and OS and p
Conclusion
The results indicate that large doses per fraction of high-
dose-rate brachytherapy are feasible and late adverse
events manageable. The incidence of severe urinary and
IPSS scores events is similar for all groups with no
significant difference in PSA control for single-dose versus
2 to 4 fractions of HDF-BT at this relatively early stage.
Whilst longer follow up is required a large single dose of
HDR brachytherapy appears both safe and effective.
OC-0270 QoL and toxicity of HDR prostate
brachytherapy as monotherapy 19Gy single
fraction:phase II trial
A. Gomez-Iturriaga
1,2
, F. Casquero
1
, P. Minguez
1
, J.
Espinosa
1
, A. Bueso
1
, J. Cacicedo
1
, L. Fernandez
1
, S.
Pedraza
1
, J. Garcia Escovedo
1
, P. Bilbao
1
1
Hospital de Cruces, Oncologia-Radioterapia, Baracaldo-
Vizcaya, Spain
2
Biocruces Health Research Institute, Radiation
Oncology, Barakaldo, Spain
Purpose or Objective
High-dose rate brachytherapy (HDR-BT) is an advanced
technology theorized to be more advantageous than Low
Dose Rate-BT (seeds) and External Beam Radiotherapy
(EBRT), to the patient himself, and in terms of resource
consumption.
Evidence supports the use of HDR-BRT as monotherapy for
selected patients with low- and intermediate-risk prostate
cancer when administered in 4 or more fractions. There is
limited data on the safety and efficacy of HDR given in a
single fraction.
The primary endpoint of this study is to evaluate the
safety, tolerance and impact on quality of life (QoL) of the
BT-HDR 19Gy administered in single fraction in patients
with low and intermediate risk prostate cancer. Secondary
endpoint is to measure the efficacy, in terms of cancer
control and satisfaction of the patients undergoing the
experimental treatment.
Material and Methods
From January 2014 to July 2016, 43 consecutive patients
have been treated with HDR-BT 19Gy administered in a
single fraction. Eligible patients had low or intermediate-
risk prostate cancer; IPSS lower than 15; prostate volume