ESTRO 36 Abstract Book

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S715 ESTRO 36 2017
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After a median follow-up (FU) after ENRT of 44 mo (range,
2-133), 27 pts (51%) showed PSA progression, with a 5-yr
biochemical disease free-survival of 43±8.3%. The 5-yr
distant progression-free survival (DPFS) rate was
58.2±8.5% (n=19 pts with clinical progression). Pts with a
PSA DT at relapse <3 mo showed a worse 5-yr DPFS
compared to pts with a PSA DT ≥ 3mo (36.8% vs. 63.6%,
p=0.029), while a trend towards significance was observed
for pts with 1 vs ≥ 2 recurrent nodes (71.8% vs. 44.9%,
p=0.089). Overall survival rate at 5-yr was 86.4±6.9% (2
over 4 pts died from PCa). Ten of 19 clinically relapsing
pts presented a new oligometastatic progression (7
nodal/2 bone/1 combined). One patient presented a local
relapse in the previously untreated prostate bed. Eight out
10 pts were treated with a new RT course, with 3 pts in
complete remission at last FU. Only 2 pts presented with
a CTCAE v3.0 Grade ≥2 genitourinary toxicity.
Conclusion
ENRT combined with concomitant short-course AD is a safe
and effective salvage modality for patients with
oligorecurrent nodal PCa, able to better delay distant
progression compared to historical series using focal SBRT.
Prospective randomized studies comparing focal SBRT vs
ENRT are warranted to define the best treatment strategy
for oligorecurrent nodal PCa.
EP-1347 Treatment outcomes with hypofractionated
high-dose radiation therapy for prostate cancer
D. Candini 1, F. López Campos1, C. Vallejo Ocaña1, M.
Martín Martín1, A. Hervás Morón1
1 Hospital Ramon y Cajal, Radiation Oncology, Madrid,
Spain
Purpose or Objective
To report treatment results, genitourinary (GU) and lower
gastro-intestinal (GI) toxicity of a retrospective cohort of
prostate cancer patients treated with hypofractionated
radiotherapy (hypo-RT) with a high equivalent biological
effective dose (BED).
Material and Methods
From April 2014 to October 2015, 35 patients with
histologically confirmed intermediate risk prostate cancer
defined by National Comprehensive Cancer Network
(NCCN) risk group were assigned to receive hypo-RT with
a total dose of 63,4 Gy/20 fractions. Use of image-guided
techniques (IGRT) with fiducial markers was required. All
patients were given radiotherapy with 6 months of
neoadjuvant and concurrent androgen suppression. GI and
GU toxicity were prospectively evaluated according to
modified RTOG criteria. Toxicity was considered “acute”
if occurred during and/or within 3 months after the
treatment and “sub-acute” if occurred between 3 and 12
months after the treatment. Biochemical recurrence was
defined as a PSA concentration superior than nadir plus 2
ng/mL.
Results
35 patients with a median age of 76 years (range 61-86
years) were treated in the defined period receiving hypo-
RT. The median follow-up was 20.3 months (range 12 – 30
months).
Acute GU toxicity grade I occurred in 20 patients (57.1%),
grade II in 2 patients (5.7%). Acute GI toxicity grade I were
observed in 6 patients (17.1%), grade II in 3 patients
(8.6%). None developed acute GU or GI toxicity grade III or
IV.
Sub-acute GU toxicity occurred as follows: grade I in 9
patients (25.7%) and grade II in 1 patients (2.9%). Sub-
acute GI toxicity grade I was observed in 6 patients (17.1%)
and grade II in 3 patients (8.6%). No late grade III-IV GU or
GI toxicity was detected. For one patient a TURP was
planned at 8 months after treatment, for urethral
stricture.
Only 1 patient (3%) developed biochemical recurrence
after a follow-up of 27 months.
Conclusion
Hypo-RT (63,4 Gy/20 fractions) with a high equivalent BED
(EQD2Gy_tumor = 85 Gy) produces aceptable acute and
sub-acute toxicity rates with excellent outcomes of
biochemical control for intermediate risk prostate cancer.
Longer term follow-up should be analyzed to confirm
these data.
EP-1348 Set-up errors in prostate cancer radiotherapy
based on cone-beam computed tomography.
M. Trignani1, G. Caponigro1, M. Di Biase 1, P. Bagalà1, M.D.
Falco 1, A. Vinciguerra1, A. Augurio1, M. Di Tommaso1, L.
Caravatta1, D. Genovesi1
1Ospedale Clinicizzato S.S. Annunziata, Radiotherapy,
Chieti, Italy
Purpose or Objective
To evaluate set-up accuracy using cone-beam computed
tomography (CBCT) in patients with prostate cancer
receiving VMAT (volumetric modulated arc therapy) or
IMRT (intensity modulated radiation therapy) techniques.
Material and Methods
From January 2015 to September 2016, 1199 CBCT
referred to 98 prostate cancer patients received radiation
treatment at our Institution using Elekta Synergy Agility
Linear Accelerator were acquired, recorded and
evaluated.
All patients underwent to planning computed tomography
(CT) in supine position; knees and ankles were placed in a
steady and comfortable position using a footrest. CT scans
with slices at 5 mm were acquired at 2 mm in condition of
fully bladder (0.75 liter of water, 45 minutes prior to CT
scan) and empty rectum. Planning CT was sent to
Oncentra Master Plan planning system and then via DICOM
to XVI software for co-registration with the CBCT scans.
For the CBCT acquisition we used the “pelvis M15”; the
Grey level algorithm was employed to obtain 3D-3D co-
registration with CT planning. An internal protocol was
adopted to reduce interfraction set-up errors and to
correct systematic errors. This protocol consisted in the
execution of 5 consecutively CBCT during first week of
treatment and once weekly CBCT during RT course. On the
basis of literature data an on-line correction protocol was
adopted: the tolerance level was 3 mm for translation
displacements and 3° for rotations; translation
displacements were applied in case of values >3 mm, while
for rotation >3° patients were repositioned. Then an
offline correction was applied with the mean of first 5
scans used to correct systematic errors with 3 mm. Means
(m) and standard deviations (SD) of all translational (x, y,
z) and rotational displacements were calculated in
relation to the first 5 and the following CBCTs. The
Wilxocon test was used to evaluate statistically significant
differences between displacements related to first 5
CBCTs and to the following CBCTs.
Results
Results are summarized in Table 1. Median values were <3
mm for all CBCTs, for both the first five and following
CBCTs, mean values were within 5mm. Greater shifts were
observed on z axis. Wilcoxon test showed a statistically
significant correlation only for the x (p value = 0.001).
Conclusion
In our study, we have analyzed translational set-up
uncertainties in prostate cancer treatments using CBCT
and we found that all the displacements were within 5
mm, well within the offset established. The action level
of 3 mm currently adopted at our center results safe and
it constitutes a good start point to reduce margin CTV-
PTV.
EP-1349 Adjuvant hypofractionated radiotherapy for
prostate cancer: acute toxicity
S. Saldi1, R. Bellavita2, I. Palumbo3, C. Mariucci1, E.
Arena1, M. Lupattelli2, M. Mendichi1, M. Tenti1, F.
Tamburi2, V. Bini4, C. Aristei3
1University of Perugia, Radiation Oncology Section,