ESTRO 36 Abstract Book

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S710 ESTRO 36 2017
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was observed in 7 patients (30%) with a G2 urinary
frequency observed in two of these patients (9%); in only
one patient a G2 urinary retention was observed and it was
treated with transient catheterization and oral and rectal
medications. No acute gastrointestinal ≥ G2 or genito-
urinary ≥ G3 toxicity was found. No other toxicities were
observed. At a median FUP of 16 months (range 7-27, from
the time of diagnosis), only one patient presented an
outfield relapse of disease, that was treated with
androgen deprivation therapy (ADT). No other biochemical
recurrence or progression of disease was observed.
Conclusion
Preliminary findings show that our schedule
of hypofractionated radiotherapy, delivered with FFF-
VMAT and gated using beacon transponders, is a valid
option for intermediate risk PC. Early results in terms of
feasibility, toxicity profile and disease control are
encouraging to warrant the pursuance of the study.
EP-1338 High precision radiotherapy for early
prostate cancer with concomitant boost to the
dominant lesion.
G. Riva1 , G. Timon1 , D. Ciardo1, A. Bazani2, D. Maestri2,
D. De Lorenzo3, F. Pansini2, R. Cambria2, F. Cattani2, G.
Marvaso 1, D. Zerini1, D.P. Rojas1, S. Volpe1, F. Golino1, V.
Scroffi 1, C. Fodor 1, G. Petralia4, O. De Cobelli5, R.
Orecchia6, B.A. Jereczek-Fossa7
1 Istituto Europeo di Oncologia - IEO, Radiotherapy,
MIlan, Italy
2 Istituto Europeo di Oncologia - IEO, Medical Physics,
MIlan, Italy
3 Istituto Europeo di Oncologia - IEO, Scientific Direction,
MIlan, Italy
4 Istituto Europeo di Oncologia - IEO, Radiology, MIlan,
Italy
5 Istituto Europeo di Oncologia - IEO, Urology, MIlan, Italy
6 Istituto Europeo di Oncologia - IEO, Medical Imaging and
Radiation Sciences, MIlan, Italy
7 Istituto Europeo di Oncologia - IEO- Università degli
Studi di Milano, Radiotherapy, MIlan, Italy
Purpose or Objective
To report preliminary results, in terms of acute toxicity,
of an innovative hypofractionated treatment with
concomitant boost to the dominant lesion for patients
with early stage prostate cancer (PCa).
Material and Methods
This prospective phase II trial, supported by AIRC
(Associazione Italiana per la Ricerca sul Cancro), started
in June 2015. Patients with low- and intermediate-risk PCa
who met the inclusion criteria underwent
hypofractionated radiotherapy (RT) to the prostate with a
total dose of 36.25 Gy in 5 fractions (biologically
equivalent to a 90.6 Gy, considering a α/β ratio of 1.5 Gy)
and a simultaneous integrated boost (SIB) to the dominant
intraprostatic lesion (DIL) of 37.5 Gy in 5 fractions
(biologically equivalent to a 96.4 Gy, considering a α/β
ratio of 1.5 Gy). The DIL was identified by a
multiparamentric magnetic resonance imaging (mpMRI)
co-registered with planning CT. The treatment was
delivered using a Varian TrilogyTM with RapidArc®
technology. Toxicity was assessed according to CTCAE v4.0
and RTOG/EORTC criteria. The preliminary evaluation of
the first 13 patients was required to assess the feasibility
of the treatment before completing the enrollment of 65
patients.
Results
The first 13 patients completed the treatment between
June 2015 and February 2016. Patients’ characteristics are
reported in Table 1. An example of dosimetric distribution
is shown in Figure 1. With a median clinical follow-up of
5.9 months, ranging from 1 to 6 months, no grade 3 or 4
acute toxicity was reported. At the end of RT, only one
patient experienced G2 gastrointestinal (GI) toxicity, and
4 patients had G1 genitourinary (GU) events. After one
month, G1 GI toxicity was reported in 2 patients and G1
GU in 4 patients; no toxicity higher than G2 has been
recorded. At 6 months from the end of treatment, 8
patients have been evaluated and no events higher than
G2 have been experienced: 1 patient had G1 GI toxicity
and 3 patients had G1 GU toxicity.
Conclusion
Up to October 2016, 42 patients have completed the
treatment. More mature results seem to confirm the
presented preliminary ones. Our preliminary data show
the feasibility of an extremely hypofractionated schedule
with concomitant boost on the mpMRI-identified DIL. The
higher number of patients expected for the trial and a
longer follow-up are needed to confirm these results. The
secondary endpoints of the study, namely the evaluation
of late toxicity, patient free survival, overall survival,
quality of life and pattern of failure will be investigated
when more mature follow-up data will be available.
EP-1339 Feasibility and efficacy of moderately
hypofractionated radiotherapy in high risk prostate
cancer
G. Marvaso1, G. Riva2, C. Bassi2, C. Fodor2, D. Ciardo2, D.
Zerini2, G. Timon2, A. Surgo3, A. Maucieri3, F. Pansini4, P.
De Marco 5, F. Cattani6, O. De Cobelli 7, R. Orecchia8, B.
Jereczek-Fossa 9
1European Insitute of Oncology, radiation oncologist,
Milan, Italy
2European Institute of Oncology, Radiotherapy, Milan,
Italy
3IEO-University of Milan, Radiotherapy, Milan, Italy
4European Insitute of Oncology, Medical Physics, Milan,
Italy
5IEO- University of Milan, Medical Physics, Milan, Italy
6European institute of Oncology, Medical Physics, Milan,
Italy
7IEO- Univesity of Milan, Urology, Milan, Italy
8IEO, Scientific Direction, Milan, Italy
9IEO- University of Milan, Radiotherapy, Milan, Italy
Purpose or Objective
Prostate cancer (PCa) is the second most common male
cancer. The prognosis for patients with a diagnosis of high-
risk PCa is poor. No consensus exists on the most effective
treatment. In the last decade, hadrontherapy with carbon
ions has been considered a suitable strategy for high-risk
PCa, in terms of the dose delivery with a resulting