737 / 1096
S721
ESTRO 36
_______________________________________________________________________________________________
based SBRT was performed with Volumetric Modulated Arc
Therapy in its RapidArc form and flattening filter free
beams. The treatment schedule was 35 Gy in five fractions
delivered on alternate days. The PTV included the
prostate for low risk and prostate plus seminal vesicles for
intermediate risk, with a 5 mm margin in all other
directions. Toxicity was recorded according to CTCAE
criteria v4.0. Biochemical failure was calculated according
to the Phoenix definition. The Expanded Prostate Cancer
Index Composite questionnaire was used to record health-
related quality of life.
Results
From May 2012 to April 2016, 50 patients were enrolled.
Twenty-five patients were classified in low risk group and
25 in intermediate risk group. Mean age was 78 years old
(range 75 – 84); Gleason score was 6 in 26 and 7 in 24
patients. Median initial PSA was 6,43 (range 2,6 – 17).
Median follow-up was 26 months. Acute toxicity was mild.
Rectal toxicity was reported as grade 1 in 5 (10%) cases
and grade 2 in 1 (2%) cases; grade 1 and grade 2
genitourinary toxicity was described in 13 (26%) and 14
(28%) patients, respectively. In the late setting, 3 (6%)
patients reported rectal grade 1 toxicity. Genitourinary
late effects were reported as grade 1 in 13 (26%) patients
and grade 2 in 2 (4%) patient. Regarding outcome, median
nadir PSA was 0.51 ng/ml (range 0.01 – 3.12). Trend of PSA
is reported in Figure 1. No biochemical relapses were
observed during follow-up and all patients are alive at the
moment of the analysis.
Conclusion
Gantry-based SBRT with VMAT and FFFs can be considered
an effective, non-invasive and safe approach for elderly
patients affected by prostate cancer at low and
intermediate risk. Randomized trials comparing SBRT with
other approaches in this setting are necessary.
EP-1344 Long-term quality of life after high-dose-rate
brachytherapy boost for prostate cancer
W. Busser
1
, I. Korfage
2
, S. Aluwini
1
1
Erasmus MC Cancer Institute, Radiation Oncology,
Rotterdam, The Netherlands
2
Erasmus Medical Center, Public Health, Rotterdam, The
Netherlands
Purpose or Objective
Quality of life (QoL) of patients treated for prostate
cancer (PCa) is relevant because of the long survival of
these patients. We aimed to report late toxicity
incidences and generic and PCa-specific health-related
QoL and to investigate associations between toxicity and
QoL in patients treated with high-dose-rate brachytherapy
(HDR-BT) boost combined with external beam
radiotherapy (EBRT).
Material and Methods
264 low- and intermediate risk PCa patients were treated
between 2000-2007 with single implant HDR-BT boost (3x6
Gy) combined with EBRT (25x1.8 Gy). Of these, 171
patients with QoL data available with 6-10 years follow-up
(FU) were included. Late grade ≥2 gastrointestinal (GI) or
genitourinary (GU) toxicity was evaluated using physicians
charts and EORTC-RTOG toxicity questionnaire at 3, 6 and
12 months and yearly thereafter. The highest score of both
was used to identify toxicity.
Between
2010-2013,
validated
self-assessment
questionnaires, EORTC QLQ-C30 for health-related QoL
and EORTC PR-25 for PCa-specific QoL, were yearly sent
to all patients. All C30 functioning domains, global health
and fatigue and pain symptoms were evaluated. The
evaluated PR25 domains were sexual activity and
functioning, urinary and bowel symptoms, and
incontinence aid use. Raw scores of each domain were
linearly transformed into 0-100 scales. Higher functional
scores indicate higher functioning and better QoL, while
higher symptom scores indicate lower QoL.
Patients with toxicity were compared to patients without
late toxicity. A multi-level linear model was used to
statistically assess the QoL differences between the 2
groups over 6-10 years FU. Covariates were included in the
analysis to control for their influence: age, PSA, prostate
volume and FU time. Clinical relevance of the differences
was assessed by means of the minimally important
difference (MID): toxicity group mean scores ≥0.5 standard
deviation different from the non-toxicity group, were
considered clinically relevantly different.
Results
Late grade ≥2 toxicity was reported by 79 patients (46.2%),
of whom 57 (33.3%) had GU and 30 (17.5%) had GI
symptoms. Of both C30 and PR25, 364 questionnaires were
analysed (mean 2.1 per patient).
Generic QoL (C30)domains did not show any statistically
significant differences (Table 1). PR25 PCa-specific QoL
for both urinary and bowel symptoms showed clinically
relevant worse QoL scores for patients with grade ≥2
toxicity (p<0.001 and p=0.01, respectively). Of sexually
active patients, patients with toxicity reported better
sexual function (p=0.001); which was also clinically
relevant. The included covariates did not show any
associations
with
QoL
score
differences.
Conclusion
For patients treated with EBRT and HDR-BT boost, late
grade ≥2 toxicity was not associated with decreased QoL
for generic QoL domains, but associations between
toxicity and decreased PCa-specific QoL scores were
observed. The higher sexual functioning scores in the
toxicity group are hard to explain and worth more
investigation.
EP-1345 Dosimetric effect of seed-based prostate
localisation on Pelvic Lymph Nodes in High-Risk
Prostate Ca
R. Valentine
1
, E. Miguel Chumacero
2
1
NHS greater glasgow and clyde, Department of
Radiotherapy Physics, glasgow, United Kingdom
2
NHS greater glasgow and clyde- University of Glasgow,
Department of Radiotherapy Physics, Glasgow, United
Kingdom