ESTRO 36 Abstract Book

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S719 ESTRO 36
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period were retrospectively collected. Dosimetric data
were captured including method of treatment delivery:
static intensity modulated radiotherapy (IMRT) or
volumetric modulated arc therapy (VMAT); dose to
prostate and pelvic node volume, as well as a single dose
level indicating normal tissue exposure (V50 to bowel,
rectum and bladder, that is volume of normal tissue of
each receiving ≥50Gy).
Results
The median age was 64 years. 88.1% of patients had
Gleason grade ≥8 cancer and 78.6% had local staging ≥T3a.
52.4% of patients were N0 with the remaining 47.6% N1; 1
patient had M1a disease. Treatment was by IMRT in 61.9%
of patients and by VMAT in 38.1%. All patients received 74
Gy to prostate. Dose to pelvic nodes was 60Gy in 78.6%,
55Gy in 19% and 56Gy in 1 patient. There was no
significant difference in nodal dose received by IMRT vs
VMAT groups. All patients had neo-adjuvant and adjuvant
hormone therapy. Median follow up was 37 months. Acute
bowel toxicity (RTOG) was <2 in 73.8% and maximally =2
in 26.2%. Late bowel toxicity was <2 in 83.3%, and
maximally =2 in 16.7% Acute urinary toxicity was <2 in
85.7%, =2 in 7.1% and maximally 3 in 7.1%. Late urinary
toxicity was <2 in 59.5%, =2 in 35.7% and maximally 3 in
4.8%. Endoscopy rates during follow up were low: 7
patients had lower GI endoscopy with radiation proctitis
confirmed in 5; 8 patients had cystoscopy with radiation
related mucosal changes in 3. 14.3% of patients have
experienced biochemical failure during follow up.
V50 rectum and bladder are significantly lower in patients
treated by VMAT versus IMRT; V50 rectum by VMAT =
48.81% vs by IMRT = 56.19% p=0.017; V50 bladder by VMAT
= 46.88% vs by IMRT = 58.85% p=0.010. This has not
translated into any significant difference in acute or late
toxicities between the groups split by treatment modality.
No significance difference was seen between V50 bowel in
VMAT vs IMRT treated patients.
Conclusion
In high-risk N0 and N1 prostate cancer, treatment by
advanced conformal radiotherapy to prostate and pelvis is
associated with acceptable levels of toxicity and good
biochemical control at 37 months. There is evidence of a
dosimetric advantage with VMAT over static field IMRT.
EP-1341 Pelvic SABR with HDR boost in intermediate
and high risk prostate cancer (spare): early results
H.B. Musunuru1, A. Deabreu1, M. Davidson1, A. Ravi1, J.
Hlou1, L. Ho1, P. Cheung1, D. Vesprini1, S. Liu1, W. Chu1,
H. Chung 1, L. Zhang1, A. Loblaw1
1 Odette Cancer Centre- Sunnybrook Hospital- University
of Toronto, Radiation Oncology, Toronto, Canada
Purpose or Objective
ASCENDE-RT has provided level 1 evidence supporting the
use of androgen deprivation therapy (ADT), external beam
radiotherapy and brachytherapy boost in intermediate-
and high-risk prostate cancer. The objectives of this study
are to report early toxicity and quality of life (QOL)
outcomes in patients treated on a hybrid protocol using
five-fraction pelvic stereotactic ablative radiotherapy
(SABR) with a MRI dose painted HDR brachytherapy boost
(HDR-BT).
Material and Methods
A phase I/II study was performed where intermediate (IR)
and high-risk (HR) prostate cancer patients received HDR-
BT 15Gy in single fraction to the prostate and up to 22.5Gy
to the MRI nodule. Gantry-based 25Gy SABR was delivered
to pelvis, seminal vesicles and prostate in 5 weekly
fractions. ADT was used for 6-18 months. Common
Terminology Criteria for Adverse Events version 3.0 was
used to assess toxicities. QOL was captured using EPIC
questionnaire at 3months 6months and then every 6
months. A minimally clinically important change (MCIC)
definition was triggered if the EPIC QOL score at each time
point decreases > 0.5 SD, where SD is the standard
deviation of baseline scores.
Results
Thirty-three patients (NCCN 6.0% low IR, 45.5% high IR and
48.5% HR) completed the planned treatment with a
median follow-up of 13.8 months (IQR 12.1, 18.8). The
incidence of worst toxicities is shown in Table 1. The 3
grade 3 GU patients were due to temporary urinary
catheterization in the acute period following HDR-BT.
Mean (95% SD) EPIC urinary QOL scores were 82.5 (16.5),
83.2 (12.9) and 83.7 (16.3) at baseline, 3 months and 12
months and the bowel scores were 95.9 (3.8), 92.6(8.2)
and 90.5 (8.3), respectively. Proportion of patients
experiencing MCIC at 3 months and 12 months were 20.8%
and 14.3% for urinary domain, 47.8% and 53.9% for bowel
domain; respectively.
DOMAIN TIMING
GRADE
2(%)
GRADE
3(%)
QOL
MCIC(%)
GENIOURINARY Acute 45.2% 9.7% 20.8%
Late 12.9% 0% 14.3%
GASTROINTESTINAL Acute 9.7% 0% 47.8%
Late 0% 0% 53.9%
Conclusion
This novel treatment protocol incorporating MRI dose
painted HDR brachytherapy boost and SABR pelvic
radiation for intermediate- and high-risk prostate cancer
in combination with ADT is feasible and well tolerated in
the acute setting.
EP-1342 Salvage stereotactic body radiotherapy for
lymph node oligorecurrent prostate cancer
G. Fanetti1, C. Fodor2, D. Ciardo 2, L. Santoro3, C.M.
Francia1, M. Muto4, A. Surgo4, D. Zerini2, G. Marvaso2, G.
Timon5, P. Romanelli2, E. Rondi6, S. Comi6, F. Cattani6,
D.V. Matei7, M. Ferro7, G. Musi7, F. Nolè8, O. De Cobelli7,
P. Ost9, R. Orecchia10, B.A. Jereczek-Fossa1
1European Institute of Oncology - University of Milan,
Department of Radiation Oncology, Milan, Italy
2European Institute of Oncology, Department of
Radiation Oncology, Milan, Italy
3European Institute of Oncology, Department of
Epidemiology and Statistics affiliation at the time of the
study, Milan, Italy
4European Institute of Oncology - University of Milan,
Department of Radiation Oncology affiliation at the time
of the study, Milan, Italy
5European Institute of Oncology, Department of
Radiation Oncology affiliation at the time of the study,
Milan, Italy
6European Institute of Oncology, Unit of Medical Physics,
Milan, Italy
7European Institute of Oncology, Department of Urology,
Milan, Italy
8European Institute of Oncology, Department of Medical
Oncology- Division of Urogenital and Head & Neck
Tumours, Milan, Italy
9Ghent University Hospital, Department of Radiation
Oncology, Ghent, Belgium
10European Institute of Oncology - University of Milan,
Department of Medical Imaging and Radiation Science,
Milan, Italy
Purpose or Objective
To evaluate the PSA response, progression free survival
(PFS), local control and toxicity of stereotactic body
radiotherapy (SBRT) for lymph-node (LN) oligorecurrent
prostate cancer.
Material and Methods
We retrospectively reviewed 95 patients with LN
oligorecurrent prostate cancer treated between 05/2012
and 10/2015. We evaluated biochemical response with