ESTRO 36 Abstract Book

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S720 ESTRO 36
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PSA dosage every 3 months after SBRT: considering the
pre-SBRT PSA as reference, a decrease in PSA of more than
10% identified responder patient, whereas an increase of
more than 10% identified a biochemical progression. The
other cases were classified as PSA stabilization. In case of
PSA increase during the follow-up, imaging was performed
to evaluate clinical progression. Toxicities were assessed
with clinical examination every 6-9 months: acute
toxicities were reported in the first 6 months after SBRT.
Results
A hundred twenty-seven lesions were treated in 95
patients with a median dose of 24 Gy given in 3 fractions.
Median pre-SBRT PSA was 3.5 ng/mL. Seventy patients
were treated for a single lesion, 25 for 2-4 lesions. In 9
patients SBRT was performed as a re-irradiation. In 35
patients androgen deprivation therapy (ADT) was added to
SBRT. Median follow-up was 18.5 months. One patient was
not valuable due to short follow-up. Biochemical
response, stabilization and progression were observed in
64 (68.1%), 10 (10.6%) and 20 (21.3%) out of 94 patients.
In the 57 patients treated with salvage SBRT alone (with
no concomitant therapy), biochemical response,
stabilization and progression were observed in 38 (66.7%),
9 (15.8%) and 10 (17.5%) cases, respectively. In 17 patients
(29.8%) with progressive disease after SBRT, ADT started
in a median time of 7.2 months (range 2.4–32.1). Clinical
progression was observed in 31 patients (33.0%) after 15
months (median time). In-field progression occurred in 12
lesions (9.4%). 2-year local control and PFS rates were 84%
and 30%, respectively (fig. 1-2). Age>75years correlated
with better biochemical response rate. Age>75years,
concomitant ADT administered up to 12 months and pelvic
LN involvement correlated with longer PFS. Acute toxicity
included urinary (6 and 1 G1 and G2 events, respectively)
and rectal events (1 G1 event). Late toxicity included
urinary (2 G1 and 3 G2 events). All toxicities were reported
in patients treated for pelvic LN. No toxicity were
reported in patients with extra-pelvic LN. At the time of
the analysis, 32 (34.0%) patients are alive with no
evidence of disease, 60 (63.8%) are alive with clinically
evident disease, 2 patients (2.1%) died.
Conclusion
SBRT is safe and offers excellent in-field control. At 2
years after SBRT, 1 out of 3 patients is progression-free.
Further investigation is warranted to identify patients who
may benefit most from SBRT and to define the optimal
combination with ADT
EP-1343 Is stereotactic body radiation therapy a viable
option for elderly patients with prostate cancer?
C. Franzese1, G. D'agostino1, L. Di Brina 1, L. Cozzi1, T.
Comito1, D. Franceschini1, F. De Rose1, P. Navarria1, E.
Clerici1, A. Ascolese1, A. Tozzi1, C. Iftode 1, S. Tomatis 1,
M. Scorsetti1
1Istituto Clinico Humanitas, Radiotherapy and
Radiosurgery, Rozzano Milan, Italy
Purpose or Objective
Data regarding the treatment of elderly patients with
prostate cancer show that Radiotherapy (RT) is
associated with a cancer specific mortality risk reduction
of 2.6% at 10 years, even after adjusting for several
confounders including 12 comorbid conditions. The aim
of the present study is to evaluate the efficacy and
toxicity of Stereotactic body radiation therapy (SBRT) in
a group of elderly patients affected by low and
intermediate risk prostate cancer.
Material and Methods
Patients aged ≥ 75 years, with biopsy-confirmed prostate
cancer were enrolled. Inclusion criteria were: initial
prostate-specific antigen (PSA) ≤ 20 ng/ml, Gleason Score
≤ 7, International Prostate Symptom Score ≤ 7. Gantry-