ESTRO 36 Abstract Book

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S391 ESTRO 36
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0.77–0.89), p=0.036] and CTV_5220 [0.15 (range 0.02–
0.36) vs 0.43 (range 0.11–0.64), p=0.002].
CTV_5220 was incorrectly positioned in 5 submissions due
to the contouring inaccuracies of GTV/CTV_6000. Other
variations in the inclusion of the scar/seroma were seen
where it was not fully encompassed axially (CTV_6000: 8
submissions, CTV_5220: 6 submissions), and wh ere
CTV_6000 was extended beyond margins longitudinally to
include it (5 submissions). In addition, some volumes were
tapered where the anatomical planes were not followed
lengthwise (CTV_6000: 5 submissions, CTV_5220: 13
submissions).
There were five re-submissions after feedback, for which
all target volumes had either acceptable, or no variation
from the protocol (mean DSC GTV: 0.75, CTV_6000: 0.83,
CTV_5220: 0.48).
Conclusion
High numbers of unacceptable variations from the trial
protocol were seen in the first submission of the training
case; the adherence to the protocol improved following
individualised feedback. As the outlining of both CTVs is
dependent on the accuracy of the reconstructed GTV in
the post-operative setting, this should be done with
particular care, with the aid of surgical reports and
diagnostic imaging.
PO-0743 Retransplantation of bony autografts
sterilized by extracorporal high dose irradiation
L. Saleh-Ebrahimi1 , A. Klein2, Y. Bakhshai2, F. Roeder1,3,
A. Baur-Melnyk4, T. Knösel5, L.H. Lindner 6, V. Jansson2,
H.R. Dürr2
1 LMU Munich, Department of Radiation Oncology,
Munich, Germany
2 LMU Munich, Department of Orthopedics, Munich,
Germany
3 German Cancer Research Center DKFZ, Department of
Molecular Radiation Oncology, Heidelberg, Germany
4 LMU Munich, Department of Radiology, Munich,
Germany
5 LMU Munich, Department of Pathology, Munich,
Germany
6 LMU Munich, Department of Internal Medicine, Munich,
Germany
Purpose or Objective
Limb-sparing resection of bone tumors requires
reconstruction of the bony defect. Retransplantation of
the resected bone after sterilisation might be an
alternative to prothetic implants especially in cases with
diaphyseal defects. Here we report our experience with
this technique using extracorporal high dose irradiation to
sterilize the resected bone.
Material and Methods
Extracorporal irradiation and retransplantation was used
in 20 patients (21 lesions) between 2005 and 2015. 13
patients were male and median age was 37 years (10-83)
with 4 patients <18 years. Main histologies were Ewing
sarcoma (7 pts), Osteosarcoma (5) and metastasis (5).
Lesions were located mainly in the lower limb (femur
n=12, tibia n=6). After resection and curettage, the
tumor-bearing bone was packed into a double sterile bag
and transported to the radiation oncology department. To
minimize any built-up effect, the bag was wrapped with
flap material and placed beneath the LINAC with the
lowest possible distance to the head, usually on a tray in
the accessory slot. After irradiation with 300 Gy in ap/pa
technique, the bone was brought back to the operation
room and retransplanted.
Results
Median follow up was 33 months (6-129) in the entire
cohort and 39 months in survivors. Retransplantation was
possible in all patients. An additional fibula augmentation
was used in 14 lesions. Surgical revisions (median n=2,
range 1-8) were needed in 12 lesions (57%) due to
complications or pseudoarthrosis. Complete integration of
the irradiated autograft was finally achieved in 17 of 19
possible lesions (89%). One patient failed with active
pseudoarthrosis and in one patient a prothetic implant was
needed secondarily due to a fractured pseudoarthrosis. In
two patients with retransplantation of the whole
irradiated calcaneus, integration was formally not
possible. Median time to complete integration was 10
months (4-35 months). Local control inside the graft and
in the affected limb was achieved in 100% and 95% of the
patients, respectively. One patient developed recurrence
outside the replanted graft, probably due to seeding
because of fracture hematoma. Four patients have died,
resulting in a 5-year overall survival of 68 %.
Conclusion
High dose extracorporal irradiation is an effective and safe
method to sterilize bony autografts during a
retransplantation procedure. Local control is achieved in
95%-100%. Complications with the need for surgical
revisions occur frequently resulting in a prolonged healing
process in more than half of the patients. However,
successful integration of the sterilized autografts is finally
achieved in the vast majority (roughly 90%).
Retransplantation after extracorporal irradiation seems to
be a very promising alternative to prothetic implants
especially in the treatment of diaphyseal or
metadiasphyseal lesions.
PO-0744 Brachytherapy and external beam radiation
therapy after re-excision surgery in soft tissue sarcomas
A. Cortesi1,2, A. Arcelli1,3, L. Giaccherini1, A. Galuppi1, V.
Panni1, A. Zamagni 1, S. Bisello1, F. Romani4, G. Bianchi5,
S. Campagnoni 5, M. Gambarotti6, G. Ghigi 2, S.
Micheletti 7, G. Macchia8, F. Deodato8, S. Cilla9, G.P.
Frezza3, A.G. Morganti 1, S. Cammelli 1
1University of Bologna, Radiation Oncology Center-
Department of Experimental- Diagnostic and Specialty
Medicine - DIMES, Bologna, Italy
2Istituto Scientifico Romagnolo per lo Studio e la Cura
dei Tumori IRST- IRCCS, Radiotherapy Department,
Ravenna, Italy
3Ospedale Bellaria, Radiotherapy Department, Bologna,
Italy
4S. Orsola-Malpighi Hospital- University of Bologna,
Medical Physic Unit, Bologna, Italy
5Rizzoli Institute, Department of Orthopaedic Oncology,
Bologna, Italy
6Istituto Ortopedico Rizzoli, Department of Pathology,
Bologna, Italy
7Istituto Scientifico Romagnolo per lo Studio e la Cura
dei Tumori IRST- IRCCS, Radiotherapy Department,
Meldola, Italy
8Fondazione di Ricerca e Cura “Giovanni Paolo II”,
Radiotherapy Unit, Campobasso, Italy
9Fondazione di Ricerca e Cura “Giovanni Paolo II”,
Medical Physics Unit, Campobasso, Italy
Purpose or Objective
To evaluate outcomes in patients with primary high grade
soft tissue sarcomas (STS), treated with perioperative
brachytherapy (BRT) and adjuvant external beam
radiation therapy (EBRT) after re-excision of the tumor
bed, post unplanned surgery.
Material and Methods
The primary aim of this retrospective study was to analyse
local control (LC). Secondary objective were metastasis-
free survival (MFS), diseases-free survival (DFS) and
overall survival (OS) in a large patient population. BRT
delivered dose was 20 Gy (15-22 Gy) using Low Dose-Rate
or Pulsed Dose-Rate technique. EBRT was delivered with
3D-technique using multiple beams; the median
prescribed dose was 46 Gy to the PTV (range 40-60 Gy),
conventionally fractionated. Univariate analysis was
estimated according to Kaplan-Meier method and log-rank
test.