ESTRO 36 Abstract Book

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S696 ESTRO 36 2017
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2 Good Samaritan Hospital Medical Center, Urology, West
Islip, USA
Purpose or Objective
Radiation technique for prostate cancer has continuously
evolved over the past several decades. We describe the
effect of utilizing prostate MRI, implementation of strict
dose-volume constraints and reducing dose to the
uninvolved prostate to <80 Gy on radiation dosimetry and
patient outcomes.
Material and Methods
From 1/10 to 4/12, 48 consecutive patients were treated
with standard prostate IMRT (S-IMRT) to 81 Gy. From 5/12
to 4/15, 50 consecutive patients were treated with
modern IMRT (M-IMRT) treating the entire prostate to 75.6
to 79.2 Gy while using prostate MRI fusion, dose volume
constraints prioritizing normal tissue avoidance above PTV
coverage and boosting any dominant intraprostatic masses
to 79.2 to 81 Gy. We compared rectal Dmax, V75, V60,
V65, V50 and bladder Dmax, V75, V70 and V65 and acute
and late toxicity between the S-IMRT and M-IMRT groups.
Results
The median follow-up for the S-IMRT group was 61 months
compared to 26 months (p<0.001). Patient characteristics
were well matched except for a higher percentage of
NCCN low risk patients in the S-IMRT group. M-IMRT
resulted in a significant reduction in median rectal Dmax,
rectal V75, rectal V70, rectal V65, bladder Dmax, bladder
V75, bladder V70 and bladder V65 (p<0.01 for all). There
was no significant difference in rectal V50. There were no
significant differences in acute GI or GU toxicity. The 2-
year rate of late grade >=2 rectal bleeding was 13% with
S-IMRT vs. 3% with M-IMRT (p=0.03). The 2-year rate of
late grade >=2 genitourinary toxicity was 11% for S-IMRT
vs. 5% for M-IMRT (p=0.21). There were no differences in
biochemical control or overall survival.
Conclusion
While modern MR-guided IMRT for prostate cancer
requires increased resources, there is a clear benefit in
terms of reduced toxicity without sacrificing disease
control implying improved therapeutic ratio.
EP-1312 Long terms outcome in prostate cancer with
image guided and intensity modulated radiation
therapy.
C. Salas1, L. Gutiérrez1, S. Garduño1, M. Macias1, L.
Ingunza1, I. Villanego1, V. Díaz1, E. Gonzalez1, L. Díaz1, A.
Ureña 2, L. Quiñones2, J. Jaén1
1 Hospital Universitario Puerta del Mar, Comprehensive
Care Department Cancer- Radiation Oncology Service-
University Hospital Puerta del Mar, Cadiz, Spain
2 Hospital Universitario Puerta del Mar, Clinical
management unit Hospital Radiophysics and Radiation
Protection- University Hospital Puerta del Mar, Cadiz,
Spain
Purpose or Objective
The use of gold seeds as radiopaque fiducials (MF)
intraprostatic indirectly to locate and visualize the
prostate treatment with RT dose escalation, it`s called
Image Guided Radiation Therapy (IGRT). Combined with
Intensity Modulated Radiation Therapy (IMRT), we
increased technical precision and high dose to the target
volume with dose limiting to the rectum and bladder
(OAR).
To report long-term tumor control and late
gastrointestinal (GI) and genitourinary (GU) toxicity rates
in low, intermediate and high risk prostate cancer (PC)
patients, treated with IGRT with fiducial markers
and IMRT.
Material and Methods
Between January 2012 and April 2015, 104 men with PC
(T1c-T3a), prostate-specific antigen [PSA] 5-20 ng/dL, or
Gleason score [GS] 6 and 7, received normofractionated
external radiation therapy and IGRT. 30% received short
androgen deprivation (AD) and 70% without AD. The dose
was 76 Gy at least 98% the planning target volume in 38 (2
Gy) daily fractions, using IMRT with 6 Mv. Daily image
guidance of the prostate was performed with two
Electronic Portal Imaging Device (EPID) (antero-posterior
and lateral) by automatic matching of the four fiducial
markers, in ONCOR. Planning target volume was defined
as prostate ± seminals vesicles with 7-mm. margin, except
5-mm. in rectal. Constraints: rectum V70<10%, V50<50%;
bladder V70<35%, V65<50%. Biochemical failure was
defined according to Phoenix criteria (nadir + 2ng/dL).
Follow-up was every 6 months during first 3 years and
annually thereafter. GI and GU toxicity were prospectively
assessed and scored according to the Radiation Therapy
Oncology Group (RTOG).
Results
Median follow-up was 43 months (range 36-48). Median
age was 69 years (range 52-79); 12% had a Gleason score
(GS) of 7 and 88% GS of 6. Median initial PSA was 7.8 ng/dL
(range 3.6 -19 ng/mL) , 79% had low , 15% intermediate
and 6% high risk. One patient developed biochemical
failure; one patient developed bone metastases, 3
patients died from other causes. Four-year actuarial
biochemical recurrence-free, cancer-specific, and overall
survival rates were 98%, 98%, and 95%, respectively. The
worst grade 2-3 GU or GI late toxicity was 3% and 1%,
respectively. At the last follow-up, grade 2-3 late GI and
GU toxicity rates were 1 % for both groups. No grade 4 or
5 late toxicity occurred.
Conclusion
IGRT with intraprostatic fiducial markers and IMRT for
PSA< 20 ng/ml prostate cancer, is associated with
excellent long-term biochemical control with very low late
GU and GI toxicity.
EP-1313 18 F NaF PET use in prostate cancer staging
in a single centre 2013-2016: retrospective review
M. Higgins1, J. Murphy2, K. Nugent3, K. O'Regan2, P. Kelly 3
1Cork University Hospital- Cork- Ireland, Radiation
Oncology, Dublin, Ireland
2Cork University Hospital- Cork- Ireland, Radiology, Cork,
Ireland
3Cork University Hospital- Cork- Ireland, Radiation
Oncology, Cork, Ireland
Purpose or Objective
NaF PET/CT has been in use at Cork University Hospital in
staging prostate cancer since March 2013. Its advantage is
increased sensitivity and specificity in detecting bone
metastases compared with Tc99 bone scintigraphy. The
detection of occult bone metastases may result in changes
to treatment recommendations with potentially
significant impact on patient quality of life. Our aim was
to assess the impact of NaF PET CT on treatment decisions
in our regional cancer centre.
Material and Methods
A retrospective analysis was performed of NaF PET/CTs
undertaken at the PET/CT Unit at CUH from March 2013
to March 2016. Imaging studies on the Picture Archiving
and Communication System (PACS) as well as electronic
and paper-based patient records were reviewed
Results
43 NaF PET/CTs were performed on 39 men with prostate
cancer in CUH between 20th March 2013 and 31st March
2016. Indications for NaF PET/CT included:
1.Initial staging of newly diagnosed prostate cancer,
mainly with high grade disease (Gleason 8-10) or
discordant standard staging studies (Tc99 bone scan, MRI,
CT) [Group 1]
2. Prior treatment and suspected first osseous metastasis
{Group 2]
3. Suspected progression of osseous metastatic disease
with negative/indeterminate standard imaging[Group 3]