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S138

ESTRO 36 2017

_______________________________________________________________________________________________

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

THIS ABSTRACT FORMS PART OF THE MEDIA PROGRAMME

AND WILL BE AVAILABLE ON THE DAY OF ITS

PRESENTATION TO THE CONFERENCE.

OC-0271 The clinical outcome after high dose rate

brachytherapy as monotherapy in localized prostate

cancer

S. Kariya

1

, K. Kobayashi

1

, I. Yamasaki

2

, S. Ashida

2

, K.

Inoue

2

, T. Yamagami

1

1

Kochi Medical School, Department of Radiology,

Nankoku, Japan

2

Kochi Medical School, Department of Urology, Nankoku,

Japan

Purpose or Objective

The aim of this study is to report the clinical outcome

after a single implant, high dose rate (HDR) brachytherapy

in localized prostate cancer.

Material and Methods

Eighty-three patients, 2 with low-risk (T stage < or = 2a,

PSA < or = 10 ng/ml, and Gleason score (GS) < or = 6), 28

with intermediate-risk (T stage = 2b or 2c, PSA > 10 and <

or = 20 ng/ml, GS = 7), and 53 with high-risk (T stage > or