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ESTRO 36 2017
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essential to treatment planning and may be discarded in
future.
EP-1785 use of rectal tube in vaginal cuff HDR-
brachytherapy: an unexpected advantage
A. Cerrotta
1
, C. Tenconi
2
, B. Pappalardi
1
, T. Giandini
2
, S.
Naimo
1
, D. Mazzeo
2
, E. Mazzarella
2
, S. Grisotto
2
, M.
Borroni
2
, C. Fallai
1
, M. Carrara
2
1
Fondazione IRCCS Istituto Nazionale dei Tumori,
Department of diagnostic imaging and radiotherapy-
Radiotherapy 2, Milan, Italy
2
Fondazione IRCCS Istituto Nazionale dei Tumori,
Department of diagnostic imaging and radiotherapy-
Medical Physics Unit, Milan, Italy
Purpose or Objective
Rectal toxicity, both early and late, is a substantial
problem in gynecological brachytherapy (BT) , occurring
in the majority of patients within the first 2 years after
the end of treatment. Specific strategies and efforts are
needed to limit high doses to the rectal mucosa without
reducing the overall target coverage. The aim of our
study, following an occasional observation, is to evaluate
if the rectal tube we use in our Institute for in vivo
dosimetry allows also a reduction of the rectal dose.
Material and Methods
In our Institute, adjuvant vaginal BT is always Image
Guided (CT/MRI) with a multichannel endovaginal
applicator, chosen taking into account both the comfort
of the patient and the best contact of the applicator
surface with the vaginal mucosa. For all patients, rectal
wall in vivo dosimetry is performed with a dedicated rectal
tube integrated with dosimeters and rigidly fixed to the
endovaginal applicator. Over the time, for technical/
clinical problems, two CT scans (acquired within a time
interval of 10 minutes) were obtained in 6 patients : one
without and one with rectal tube. Each treatment plan
was generated and delivered using CT-scan with rectal
tube in order to calculate dose to target and OARs (TPS:
Oncentra Brachytherapy System). Vaginal cuff, bladder,
rectum and sigmoid were contoured by a single radiation
oncologist and the contours were reviewed by all members
of the Brachytherapy team. Plan optimization was
performed according to International guidelines . Rectum
position variation, due to the presence of the rectal tube
(diameter: 8.3 mm) , attracted the attention of the team.
The treatment plan was transferred on CT scan without
rectal tube and OARs and target doses were evaluated. For
both plans, bladder and rectum DVHs were assessed
considering the near maximum dose to 2cc of each organ,
D2cc (%). Results are reported as mean (±SD). The
Wilcoxon test for pair samples was used for comparison.
Differences were considered statistically significant at p <
0.05.
Results
No significant variation was found for bladder D2cc with
and without rectal tube: (68.7±5.9)% vs (68.7±4.2)%,
respectively. D2cc for the rectum systematically increased
in all calculated plans without rectal tube: (68.9±5.7)%
vs.( 86±6.7)%. Differences were found statistically
significant (p=0.031).
Conclusion
These preliminary results show that an unexpected
advantage of the rectal tube, used for in-vivo dosimetry,
is the favorable modification of the rectal anatomy with a
consequent significant reduction in terms of D2cc.
EP-1786 Intraoperative Brachytherapy (HDR-IOBT) in
advanced or recurrence gynecologic cancer..
E. Villafranca Iturre
1
, J. Muruzabal
2
, A. Sola
1
, P.
Navarrete
1
, M. Barrado
1
, S. Aguirre
2
, S. La Peña
2
, O.
Tarrio
2
, J. Jimenez
3
, M. Ciga
4
1
Hospital of Navarra, Radiation Oncology, Pamplona,
Spain
2
Hospital of Navarra, Gynaecology, Pamplona, Spain
3
Hospital of Navarra, Urology, Pamplona, Spain
4
Hospital of Navarra, Surgery, Pamplona, Spain
Purpose or Objective
Review our initial results in the treatment with surgery
and Intraoperative Brachytherapy (HDR-IOBT) in advanced
or recurrence gynecologic cancer.
Material and Methods
This protocol was designed in 2011 and all cases have been
approved in the Committee on Gynecologic Tumors. They
included two patient groups: Group 1: patients with
advanced cervical cancer with poor response to Radiation
and chemotherapy; group 2: patients with pelvic
recurrence of gynecological tumors of any origin. In all CT
and MRI was performed, in recurrences also PET to exclude
metastatic disease. The surgical procedure was pelvic
exenteration, enlarged cystectomy or rectal resection or
both depending on the extent of disease. After extraction
of the surgical specimen, was confirmed in all cases with
intraoperative biopsy the absence of macroscopic residual
disease. Then, put clips in the surgical bed. Subsequently
an applicator Fleipbrup Flap® (Elekta) was placed, with
an appropriate number of channels to the extension of the
bed. After intraoperative planning, a dose of 10 Gy
prescribed at 0.5 cm bed depth was administered. Finally,
the applicator was retiring to complete the surgery.
Results
In the period between October 2011 and September 2016,
22 patients have been included. In group 1, there were 11
patients with cervical cancer stage IIB in 5 p and IIIB in 6;
in group 2 were 11 recurrences of 5p cervix, 3p
endometrial carcinoma, 2 sarcoma and 1 vulva. With a
median follow-up of 22 months (1-61m), the Local DFS 2
years was 67%: Group 1: 73%; Group 2: 44%; 2 years Disease
Free Survival 54.7%: Group 1: 65%, Group 2: 32%; 2 years
Overall Survical 56%: Group 1: 76%, Group 2: 44%. The
complications were fistula: 1 intestinal, 2 bladder ,
1osteitis pubis in 1p. stenosis sigma 1p.
Conclusion
HDR-IOBT associated with pelvic exenteration offers good
results of pelvic control and overall survival in patients
with gynecologic cancer with a poor prognosis, which
usually palliative treatments are offered, although further
monitoring is required. However the number of
complications, especially fistulas has been important, so
we must take it into account for prevention. These results
are possible thanks to the multidisciplinary approach to
these patients
EP-1787 Dosimetric Implications of the organs at risk
in Vaginal Cuff Brachytherapy with ML Cylinder
N. Dumitru
1
, M. Shojaei
1
, S. Pella
1,2
, T. Leventouri
1
, J.
Pinder
1
1
Florida Atlantic University, Medical Physics, Boca Raton,
USA
2
21st Century Oncology, Medical Physics, Boca Raton,
USA
Purpose or Objective
To develop a method to evaluate the cumulative dose of
organs of risk when using the Multi-Channel Cylindrical
Applicators in vaginal cuff brachytherapy.
Material and Methods
A retrospective analysis of 30 patients treated in 2015 with
the Multi-Lumen Cylindrical Applicator with 3 cm
diameter, were considered for this study. A total of 150
fractions was received by patients, each of them receiving
5 fractions with 5 Gy each, delivered twice a week and
prescribed to the applicator’s surface for 2/3 of the
vaginal length. The CT scans of these patients, taken for
treatment plan were separately imported into the
treatment planning system and paired with the initial CT
scan after completing the contouring. Two sets of CT
images were fused at a time together with respective to
the applicator, using landmark registration. Dosimetric