ESTRO 36 Abstract Book

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S706 ESTRO 36 2017
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Our experience with VMAT-based SBRT in low-and
intermediate–risk prostate cancer demonstrates favorable
efficacy in tumor control and toxicity profile with no
decrease in QOL as determined by I-PSS, IIEF. The general
good quality of the clinical outcome and the results
concerning GI and GU toxicities seem to confirm the
robustness of the dosimetric paradigm adopted. Longer
follow-up is needed to investigate complete safety and
efficacy of the stereotactic treatments.
EP-1330 Predictive factors for urinary toxicity in
patients treated with radical ebrt for prostate cancer
C. Pisani1, A. Galla1, D. Beldì1, G. Apicella 1, G. Loi2, M.
Krengli1
1 University Hospital Maggiore della Carità,
Radiotherapy, Novara, Italy
2 University Hospital Maggiore della Carità, Medical
Physics, Novara, Italy
Purpose or Objective
Acute and late toxicity scores in patients treated with
radical external beam radiotherapy (EBRT) for prostate
cancer were correlated with dosimetry and clinical data in
order to identify some predictors for urinary (GU) toxicity.
Material and Methods
This study enrolled 280 patients (pts) treated with EBRT
as primary treatment for prostate cancer in our University
Hospital. All patients had at least 24 months follow-up,
with a median of 47 months (range: 40-98).
According with NCCN risk classification, 18% of pts were at
low risk, while the others were at intermediate or high
risk. Prescribed dose was 74-78 Gy. Adjuvant androgen
deprivation consisting of a luteinizing hormone-releasing
hormone analog, was administered in 192 patients
(68.6%).
All patients completed a pre-EBRT questionnaire,
registering baseline GU symptoms and patients’ medical
history (diabetes,hypertension, previous surgery, and
smoking) and were assessed by International Prostatic
Symptom Score (IPSS). Toxicity was registered following a
grading system based on the Radiation Therapy Oncology
Group (RTOG). Acute toxicity was defined as toxicity
occurring during or within 3 months after the end of EBRT.
Late toxicity was defined as toxicity occurring for the first
time >3 months after the end of EBRT or as acute toxicity
lasting longer than 3 months. Acute and late GU toxicities
were correlated with dosimetry and clinical parameters
(age , presence of co-morbidities including previous TURP,
tumor stage, initial PSA and Gleason Score).
Results
Median age was 74 years (range: 64-83); performance
status according with Karnofsky scale was 90 (80-100).
Fifty percent of pts had cardiovascular disease and 13% of
them had undergone TURP before EBRT. Thirty-two
percent of pts were treated with IMRT and 20% with IGRT.
Median bladder volume at simulation was 263 cc. Thirty-
one percent of pts experienced acute G1 GU toxicity, 24%
G2 and 3% G3. No G4 GU acute toxicity was reported.
Fourteen percent of pts experienced G1 late toxicity and
3% G2. We did not report any G3 or G4 GU toxicity.
IPSS baseline value significantly correlated with acute GU
toxicity in univariate (p=0.009) and multivariate
(p=0.0002) analysis.
The presence of nicturia (p=0.002), bladder urgency
(p=0.024) and incontinence (p=0.024) also significantly
correlated with GU toxicity. Bladder volume <200 cc at
CT-simulation was also associated with toxicity (p=0.014),
while maximum dose to bladder was correlated with late
toxicity (p=0.014). The use of 3D-EBRT was significantly
associated both with increased acute (p=0.032) and late
(p=0.03) toxicity.
Conclusion
In our study pretreatment IPSS, nicturia, urgency and
urinary incontinence at diagnosis, bladder volume < 200 cc
during CT-simulation, the use of 3D-EBRT and maximum
dose to the bladder was predictive for specific moderate–
severe acute urinary symptoms.
EP-1331 Efficacy and safety of re-irradiation of locally
recurrent prostate cancer with FFF-VMAT
G.R. D'Agostino 1, C. Franzese1, L. Di Brina 1, S. Tomatis 1,
C. Iftode1, D. Franceschini1, E. Clerici1, G. Reggiori1, A.
Tozzi 1, P. Navarria1, M. Scorsetti1
1Istituto Clinico Humanitas, Radiotherapy and
Radiosurgery, Rozzano Milan, Italy
Purpose or Objective
Despite considerable advances in technologies, especially
with the introduction of IMRT, IGRT, and VMAT, re-
treatment of locally recurrent prostate cancer with
external beams radiation therapy remains controversial
because of fear of major complications or unbearable side
effects. In this study we report our experience on re-
irradiation in a sample of 17 patients previously irradiated
for prostate cancer.
Material and Methods
Patients affected by prostate cancer and previously
submitted to radiotherapy were included in this study,
provided that they had an increased PSA, diagnostic for
biochemical relapse, and a PET-Choline revealing the
presence of a local recurrence of disease. Re-irradiation
consisted of a stereotactic treatment delivered by FFF
IGRT-VMAT technology in 5 daily fractions. Clinical
response was evaluated with PSA and physical
examination. Toxicity assessment according to CTCAE (v.
4.01) criteria. During follow-up, PET-Choline was
performed in the cases of PSA rising.
Results
Between November, 2012 and May, 2016, 17
patients (median age 78 years, range 59-82) were
submitted to re-irradiation on prostate (n=10, 58.8%),
prostatic bed (n=5, 29.4%) or prostate and local
recurrence (n=2 seminal vesicle, ischium 11.8%). Previous
treatment consisted on a median total dose of 74 Gy on
prostate or prostatic bed (range 66-76). Ten patients had
also received radiotherapy on seminal vesicles, four
patients on pelvic lymph-nodes. Median time from
previous radiotherapy was 80 months (range 26-116).
Median PSA at the moment of recurrence was 3.1 ng/ml
(average 4, range 1.2-13.5). As a re-irradiation, a median
total dose of 25 Gy (range 25-30) was delivered in a
median number of 5 fractions (range 5-6). An immediate
biochemical response was observed in all cases. Median
PSA nadir after treatment was 0.77ng/ml (average 1.33,
range 0.19-6.0, p=0.0004)) The sole acute toxicity
reported was genito-urinary, mainly represented by
pollakiuria and dysuria grad e 1 (n=9, 52.9%) or grade 2
(n=2, 11.8%). One patient (5.9%) had a grade 3 hematuria,
was hospitalized and submitted to continuous bladder
irrigation. A late grade 1 GU toxicity was observed in 3
patients (17.7%). No other toxicities were observed. At a
median follow-up of 16 months (range 6-36, calculated
from the time of recurrence diagnosis) 8 patients (47.1%),
experienced a biochemical recurrence, confirmed by a
positive PET-choline in 5 cases (29.4%). Median BFS was 19
months, 1- and 2-year BFS was 84.6% and 32.2%,
respectively. Median LC was 24 months, 1- and 2-year LC
was 90.9% and 40.4%, respectively. All patients are still
alive, 5 of them with measurable disease. Median OS was
96 months from the initial diagnosis (range 59-151).
Conclusion
With the technological novelties offered by modern
radiotherapy, re-irradiation of patients affected by
prostate cancer, and previously treated with radiation
therapy, confirms its safety and efficacy. Therefore, it can
be considered a valuable option for local recurrence of
this disease.
EP-1332 Contouring variability with CT and MRI of
prostate cancer for radiation planning