399 / 1082
S384
ESTRO 36 2017
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significant differences between WPRT and PORT for each
nodal risk group, either in terms of bDFS, DFS OS, age <70
years (p=0.077). Only OS curve showed a better prognosis
for WPRT, statistically significant in 15% and 20% nodal-
risk groups(Fig.2), but not confirmed by univariate
analysis.
Fig.1 LNI risk groups
Fig.2 OS stratified by LNI risk(WPRT blue and PORT red)
Conclusion
This long-term analysis failed to demonstrate a benefit for
elective WPRT compared to PORT. Due to retrospective
nature, small sample, long accrual and heterogeneity of
WPRT and PORT group, new studies need to create
performing tools for patients’ selection.
PO-0738 PET with 18F-Choline for evaluation of
prostate cancer patients with biochemical
relapse/persistence
H. Pérez Montero
1
, M.A. Cabeza
1
, A. Gómez
2
, S.G.
Guardado
1
, J.F. Pérez-Regadera
1
1
Hospital Universitario 12 de octubre, Radiation
Oncology, Madrid, Spain
2
Hospital Universitario 12 de octubre, Nuclear Medicine,
Madrid, Spain
Purpose or Objective
Current guidelines suggest 18F-choline-PET/CT imaging
(18F-Ch-PET) as a diagnostic test for the evaluation of
patients with recurrent prostate cancer (PCa). Although it
has been shown superior to conventional techniques, the
role of 18F-Ch-PET has not been established in clinical
practice.
The objective of this study was to evaluate the use of 18F-
Ch-PET to restage patients with biochemical relapse (BR)
or biochemical persistence (BP), which remains as a
controversial issue. Our main goal was to optimize the
selection of patients who may benefit the most from this
test.
Material and Methods
It is a prospective study (data collected between
February/2014 and October/2016). From the 110 scans
performed in our centre, we selected a cohort of 78.
We selected PCa patients with BR or BP after radiotherapy
and/or prostatectomy that fulfil certain conditions. Our
inclusion criteria were patients in NCCN high-risk group,
or also in intermediate risk group with unfavourable
features (primary Gleason≥4 and T≥2c). We also selected
patients with PSA doubling time (PSAdt) <8 months).
Pearson χ2 test was performed.
Results
The mean age of patients was 67 years (range 45–79).
Mean PSA was of 3.4 +/- 5.7 (0.01–38.8). Mean PSAdt was
13.4 +/- 24.7 months (0.7–158.9). Gleason was ≥7(4+3) in
50% of cases. Median follow-up after the test was 13 +/- 9
months.
Positive results were obtained in 48.7% of the scans. 57.9%
of them showed local and/or regional disease and 42.1%
had distant metastases. Tailored treatment was
performed in each case.
Scans were positive in 13.5% of patients with PSA<1 ng/mL
and in 80.5% of patients with PSA≥1 ng/mL. For this PSA
level, Sensibility and Specificity for obtaining a positive
18F-Ch-PET were 86.8 and 80% respectively (p<0.001).
In patients with DTPSA<3 months, the test was positive in
87.5% of cases (p=0.03). Additionally, 57.1% or them were
metastatic. Moreover, 82% of PSAdt>3 cases had negative
result or their recurrence were local and/or regional
(p=0.039).
We stratified 3 groups of patients according of PSA
velocity (PSAvel) and observed positivity in 23%, 52% and
81% of cases with PSAvel of 0, 0.1 and ≥ 0.2 ng/mL/month
respectively (p<0.001).
Results of the test were validated in 72% of the patients.
They were confirmed by histology in 14%, by another