ESTRO 36 Abstract Book

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S292 ESTRO 36 2017
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Conclusion
Preliminary results of this trial demonstrate for both study
arms the feasibility, tolerance, and acceptable toxicity
profile of this treatment approach. Longer follow-up is
needed to assess the impact of OTT and urethra-sparing
on outcome, late toxicity, and QoL.
PV-0553 Prognostic significance of Testosteron Level
in prostate carcinoma patients treated with TAB and
RT
G. Ozyigit1, F. Akyol1
1 Hacettepe University- Faculty of Medicine, Department
of Radiation Oncology, Ankara, Turkey
Purpose or Objective
The aim of this study is to evaluate the prognostic
significance of testosterone levels measured during total
androgen blockade (TAB) in intermediate risk (IR) and high
risk (HR) non-metastatic prostate adenocarcinoma
patients treated with three dimensional conformal
radiotherapy (3D-CRT) or intensity modulated radiation
therapy (IMRT).
Material and Methods
The clinical data of 329 eligible T1-3N0M0 (AJCC 2010)
prostate adenocarcinoma patients treated at our
department between 1996-2011 with either 3D-CRT or
IMRT were evaluated. The median age was 67 years.
D'Amico 1998 risk classification was used, and 80 patients
were in IR, as 249 patients were in HR group, respectively.
The total 3D-CRT and IMRT dose was 70 Gy, 76 Gy
respectively in 2 Gy daily fraction doses. All patients
received TAB (combined LHRH agonist and bicalutamide),
and 61% of patients were given less than 12 months of TAB.
Total testosteron levels were measured in every 3 months
during hormonal therapy. The castration level for
testosteron was accepted as ≤20 ng/dL according to the
European Association of Urology (EAU) criteria; and
patients were categorized as castrated group (C) and non-
castrated group (nC), accordingly. Log-rank test was used
for univariate analyses (UVA), and Cox-regression model
was used for multivariate analyses (MVA).
Results
Median follow-up was 9.2 years. There were no
statistically significant differences between C and nC
groups in terms of age, RT technique, TAB duration, risk
group, Gleason score, PSA levels, T stage and RT dose.
Five and 10 year overall survival (OS) rates were 97%, 91%
for C group, and 90%, 75% for nC group (p<0.001). Five
and 10 year biochemical relapse free survival rates (BRFS)
were 87%, 83 % for C , and 71%, 51% for nC group
(p<0.001). MVA revealed that testosteron level above 20
ng/dL (p=0.001) and Gleason score of 8-10 (p0.01) were
found to be independent significant poor prognostic
factors in predicting OS and BRFS.
Conclusion
The prognostic significance of testosteron levels was
previously demonstrated in metastatic prostate cancer
patients receiving hormonal therapy, but not for non-
metastatic patients receiving TAB and radiotherapy . In a
median follow-up of 9.2 years, we found that non-castrate
levels of testosteron (>20 ng/dL) measured during TAB had
significant detrimental effects both on overall and
biochemical relapse free survival in intermediate-high risk
non-metastatic prostate cancer patients. Thus, we
recommend to continuously monitor testosteron levels
during TAB in order to measure the efficacy of castration.
PV-0554 Patient-reported outcomes from the phase III
prostate HYPRO trial: urinary toxicity
R.C. Wortel1, L. Incrocci1, F.J. Pos2, R.J. Smeenk3, A.D.G.
Krol 4, S. Aluwini1, M.G. Witte2, B.J.M. Heijmen1, W.D.
Heemsbergen2
1 Erasmus MC Cancer Institute, Radiation Oncology,
Rotterdam, The Netherlands
2 Netherlands Cancer Institute, Radiation Oncology,
Amsterdam, The Netherlands
3Radboud University Medical Center, Radiation Oncology,
Nijmegen, The Netherlands
4Leiden University Medical Center, Radiation Oncology,
Leiden, The Netherlands
Purpose or Objective
In the Dutch phase III HYPRO trial (39x 2 Gy vs. 19x 3.4
Gy), the postulated non-inferiority of the
hypofractionation arm with respect to the incidence of
grade ≥2 late urinary toxicity was not shown. Moreover, a
significant increase in grade ≥3 urinary toxicity was
observed. In the current analysis we evaluated patient-
reported urinary symptoms and possible relationships with
hypofractionation and hospital of treatment.
Material and Methods
Patients with intermediate or high-risk prostate cancer
from four hospitals applying image-guided IMRT protocols
and recruiting >70 patients were analyzed, excluding
patients with a baseline catheter. Long-term hormonal
treatment (36 months) was prescribed to high-risk
patients in hospital A-C but not in hospital D. A total of
561 patients (n=275 for standard fractionation (SF),
hypofractionation (HF) n=296) with ≥1 follow-up symptom
questionnaire were eligible (n=2355 total questionnaires).
Treatment arm was balanced within hospitals. Local
guidelines were applied for dose (in)homogeneity, margins
(5-8 mm), and optimization. One hospital used MRI for
prostate delineation (hospital A) and another hospital
applied a rectal balloon (D). Hospital B and C varied in the
applied safety margins of 5-6mm and 8mm, respectively.
The study protocol did not provide dose constraints for the
bladder; bladder delineation was done retrospectively.
We calculated bladder and urethra dose (EQD2) with α/β
ratios of 3 Gy and 5 Gy, and analyzed incidences of urinary
symptoms between 6 months and 5 year. The impact of
treatment arm and hospital on late urinary toxicity
endpoints was calculated in a multivariate model
including time and hormonal therapy.
Results
Dose to structures within the target volume (urethra, base
of trigone area) was 78 Gy for SF vs 82.7 Gy for HF with
α/β=3 Gy, and 78 Gy for both schedules with α/β=5.
Average mean bladder dose was 29.2 Gy (SF) vs 29.9 Gy
(HF) for α/β=3, (p=0.4), and 30.2 Gy vs 29.1 Gy (α/β=5,
p=0.2), for SF vs. HF, respectively. Planned dose to the
bladder varied significantly (p<0.05) between hospitals
and was relatively low for hospital A and D (≈25 Gy vs. ≈33
Gy for hospital B and C, based on α/β=3 Gy). Symptoms of
incontinence, straining, and weak stream were on average
significantly more reported in the HF arm during follow-
up ( FIG 1A-C) and varied significantly between hospitals
(FIG 2A-C). Hormonal treatment was not predictive in the
current models. We established that baseline levels of
urinary complaints were considerable as well (FIG 1).