ESTRO 36 Abstract Book

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S699 ESTRO 36 2017
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All the 125 patients completed the planned treatment,
with good tolerance. After RT, the median follow-up was
15 months.Acute toxicities were recorded for the GU
[G0=45/125 (36%), G1=63/125 (50.4%); G2=16/125
(12.8%); G3=1/125 (0.8%)], the GI [G0=42/125 (33.6%);
G1=72/125 (57.6%); G2=11/125 (8.8%); no G3]. Analyzing
data according to RT intent, a higher rate of GU toxicity ≥
2 was found in the adjuvant setting (17.1%) respect to
salvage group (9.8%); p=0.01 at Fisher’s exact text.
Furthermore, at statistical analysis no difference was
found between the type of surgery (Robotic,Laparoscopic
or Open) and incidence of urinary incontinence (p=0.8).
The actuarial Kaplan-Meier for biochemical disease free
survival (BDFS) were 94% and 77% for adjuvant and salvage
RT, at 36 months.
Conclusion
moderate hypofractionated postoperative RT with VMAT
was feasible and safe with acceptable acute GU and GI
toxicities. Longer follow-up is needed to assess late
toxicity and clinical outcome
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EP-1317 PET-guided pelvic re-irradiation for nodal
recurrences of prostate cancer
P. Dirix1, G. De Kerf1, B. De Laere2, G. Buelens1, P.
Huget 1, D. Verellen1, P. Meijnders 1
1 Iridium Cancer Network, Department of Radiation
Oncology, Antwerp, Belgium
2 Iridium Cancer Network, Translational Cancer Research
Unit TRCU, Antwerp, Belgium
Purpose or Objective
To report our first cases of pelvic re-irradiation using
volumetric-modulated arc therapy (VMAT) with a
simultaneous integrated boost (SIB) on choline or
prostate-specific membrane antigen (PSMA) positron
emission tomography (PET) nodal uptake in recurrent
prostate cancer, after previous salvage radiotherapy
(SRT).
Material and Methods
Thirteen patients received re-irradiation for a nodal
relapse that occurred after initial radical prostatectomy
followed by SRT. All patients were initially operated for
high-risk prostate cancer between 2007-2014. The initial
SRT consisted of radiotherapy of the prostate bed and
obturator/iliac lymph nodes to 66.0/52.8 Gy in 33
fractions of 2.0/1.6 Gy, respectively, through intensity-
modulated radiotherapy (IMRT). All patients had a
consequent pelvic nodal relapse on choline (n = 6) or PSMA
(n = 7) PET-CT, without extra-pelvic disease. The location
of the pelvic recurrences is shown (Figure). The mean PSA
at time of nodal recurrence was 2.94 µg/L (range, 0.6 –
7.89 µg/L). Patients were deemed unfit for surgery and/or
surgically inoperable. The re-irradiation was initiated a
mean 46 months (range, 8 – 107 months) after SRT. All
patients received 66.0/50.0 Gy in 25 fractions of 2.64/2.0
Gy to the PET-positive lymph nodes and elective pelvic
nodal regions, respectively. Underdosage of the elective
planning target volume (PTV) was allowed (taking the
earlier SRT into account), but not of the high-dose PTV.
No androgen-deprivation therapy (ADT) was initiated. All
toxicity was prospectively scored according to the
common toxicity criteria (CTC) version 4.0.
Results
Acute toxicities were limited: no gastro-intestinal (GI) nor
genito-urinary (GU) acute toxicities ≥ grade 2 were
observed. Two patients suffered from mild grade 1
diarrhea until 2-3 weeks after radiotherapy, no acute GU
toxicities were observed. There was a mean follow-up of
17 months (range, 6 – 27 months) since re-irradiation.
Regarding late toxicity, one patient developed grade 1
hematuria at 1 year after re-irradiation which was due to
pathologically confirmed cystitis. No other late GI or GU
toxicities were observed. Regarding oncological outcome,
all patients developed an initial PSA response, defined as
a decline from baseline in PSA level of 80% or greater.
Currently, 11 patients remain controlled (without ADT) at
a mean of 16 months (range, 6 – 27 months) after re-
irradiation, with a mean PSA of 0.34 µg/l (range, 0.17 –
0.63 µg/L). Two patients progressed within 6 months after
the end of radiotherapy and currently receive (chemo-
)hormonal treatment. Interestingly, these 2 patients had
a PSA doubling time < 6 months. All the other patients had
a PSA doubling time > 11 months.
Conclusion
Pelvic re-irradiation with SIB to the PET-based nodal
recurrences is a safe and promising alternative to pelvic
lymph node dissection. However, patient selection is
crucial and could in the future be guided by biomarkers.
Also, concomitant ADT should now be considered based on
GETUG-AFU 16.
EP-1318 Is hypofractionation combined to WPRT
effective in high risk prostate cancer patients?
N.G. Di Muzio 1, A. Fodor1, C.L. Deantoni1, B. Noris
Chiorda1, S. Broggi 2, P. Mangili 2, I. Dell'Oca1, A. Chiara1,
P. Passoni 1, N. Slim1, M. Pasetti1, R. Calandrino1, C.
Cozzarini 1, C. Fiorino 1
1San Raffaele Scientific Institute, Department of
Radiotherapy, Milano, Italy
2San Raffaele Scientific Institute, Medical Physics,
Milano, Italy
Purpose or Objective
Several recent studies have concluded that
hypofractionation to prostate/seminal vesicles only
cannot be regarded as a standard in intermediate and
high-risk prostate cancer. We report here the 5 and 7
year clinical outcomes in high risk (HR) prostate cancer
(PCA) patients (pts) treated with hypofractionated
TomoTherapy (HT) and routine irradiation of pelvic
lymph-nodes (PLN).
Material and Methods
From April 2006-August 2015, 115 HR PCa pts were
treated with HT, within a phase I-II study. The dose to
PLN, was 51.8 Gy(1.85 Gy/fr), with simultaneous
integrated boost (SIB), to prostate and seminal vesicles,
up to 74.2Gy in 28 fr (2.65Gy/fr). Androgen deprivation
therapy (ADT) was prescribed to 104/115 pts for a
median of 26 (3-120) months (mos). Median age was 75
(57-90) years, median Gleason Score was 8 (5-10),
median initial PSA was 12.4 (1.7-206.0) ng/mL; clinical T
stage was: T1c-T2a in 62 pts, T2b-T2c in 35 pts, T3a-T3b
in 17 pts and T4 in 1 patient.
Results
With a median follow up of 68 (2-121) months, 19 pts
(16.5%) exhibited a biochemical relapse after a median
interval elapsed from the HT end of 64 (2-117) months.
Acute and late toxicity profile was acceptable and is
summarized in Table I. Median PSA at the last follow up
was 0.09 (0.0-900.0) ng/mL and only 7 pts had ongoing
AD. Thirteen pts (11.3%) presented clinical relapse: 2