ESTRO 36 Abstract Book

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S19 ESTRO 36 2017
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Conclusion
Taking into account conformality and OAR dose reduction,
ARC-A performed as well as B-VMAT. ARC-A does not
require couch rotation, therefore reducing set-up error
and making it easier to combine with DIBH apparatus
compared to B-VMAT. It should be considered as a
practical alternative to B-VMAT. We found it useful to
have a list of "aspirational" DCs for this planning
comparison. In practice, however, each patient’s OARs
should be set based on their clinical characteristics and
disease location and the best plan should be chosen after
comparison of at least two techniques.
PV-0044 Is involved-node radiotherapy for Hodgkin
lymphoma safe in routine?
A. Boros1 , R. Sun1, J. Arfi Rouche 2, J. Lazarovici3, D.
Ghez 3, J.M. Michot3, A. Beaudré4, A. Danu3, J. Bosq5, V.
Ribrag3, R. Mazeron1
1 Institut de Cancérologie Gustave Roussy, Radiation
Oncology Department, Villejuif, France
2 Institut de Cancérologie Gustave Roussy, Radiology
Department, Villejuif, France
3 Institut de Cancérologie Gustave Roussy, Oncology
Department, Villejuif, France
4 Institut de Cancérologie Gustave Roussy, Radiation
Physicist, Villejuif, France
5 Institut de Cancérologie Gustave Roussy, Pathology
Department, Villejuif, France
Purpose or Objective
Involved-node radiotherapy (INRT) answers the need for
reducing the irradiated volumes in Hodgkin lymphoma
patients, in promising to reduce the risk of late morbidity.
However, this concept, combined with modern
radiotherapy techniques, exposes to risks of geographic
misses. The purpose was to evaluate the efficiency of INRT
in daily routine.
Material and Methods
The data from patients with limited Hodgkin diseases
treated with a combined modality associating
chemotherapy and INRT were reviewed. Eligibility was
restricted to those with Ann-Arbor stage I-II diseases, who
had a PET-CT in treatment position prior to
chemotherapy. Supra diaphragmatic recurrences were
sorted according to radiotherapy fields as in or out-field
and their belonging to a treated lymph nodes area was
examined, with the aim to state if the target would have
been included in an involved-field radiation therapy
(IFRT). Distance relapse was defined as a recurrence
located beyond the diaphragm.
Results
Seventy-four consecutive patients were included.
Histologic subtypes were nodular sclerosis in 91%, mixed
cellularity in 7%, and lymphocyte depleted in 2%. Patients’
mean age at diagnosis was 37.6±13.1 years; median
follow-up, 40.6 months. Initially 88% of the patients had
stage II diseases and the remaining 12%, stage I. According
to the EORTC (European Organization for Research and
Treatment of Cancer) criteria 70% had early unfavorable
diseases and 30%, early favorable diseases. All patients
received ABVD, administrated in 95% of the patients for 3-
4 cycles, followed by BEACOPP after 2 cycles in 2%, or
combined with brentuximab in 5%. The mean RT dose was
30.9±2.0 Gy delivered in 1.8±0.05 Gy fractions. IMRT was
used in 42 %, and 3D conformal radiotherapy in 18%. Deep
inspiration bread hold technique (DIBH) was used in 40%,
with 3D conformal radiotherapy in all but one patient
(IMRT).
A total of 4 patients experienced relapses (crude
incidence: 5.4%), which resulted in 3- and 5-year disease
free survival rates of 96.9% and 93.8%. Three- and 5-year
overall survival rates were 100% and 97.4% respectively.
All four patients had supra diaphragmatic recurrences. In
two patients, they consisted in a mix of in- and out-field
relapses. In-field relapses occurred in regions receiving
30.6 Gy and 32.4 Gy, respectively. In the remaining two
patients, relapses were out-field on both side of the
diaphragm. In 2 patients out of 4, relapses were located
in lymph nodes regions partially irradiated with INRT (1
and 2 areas respectively).
Conclusion
Although the 4 reported relapses comprised out-field
areas, recurrences in partially irradiated lymph node
areas, which would have been potentially covered by IFRT
fields, occurred in 2 patients (2.7%). On the overall, INRT,
implemented in routine, yielded satisfactory outcomes in
regard to published series.
PV-0045 Estimation of internal risk volume for
coronary arteries after motion evaluation with ECG-
gated CT
M. Levis1, C. Fiandra1, A.R. Filippi2, F. Cadoni1, V. De
Luca1, A. Cannizzaro3, D. Garabello4, S. Veglia4, R.
Ragona1, U. Ricardi1
1University of Torino, Radiation Oncology, Torino, Italy
2San Luigi Hospital, Radiation Oncology, Orbassano
Torino, Italy
3University of Messina, Radiation Oncology, Messina,
Italy
4A.O.U. Città della Salute e della Scienza, Radiology,
Torino, Italy
Purpose or Objective
Retrospective studies in patients affected with Hodgkin
lymphoma and breast cancer demonstrated a linear
relationship between heart dose and the risk of coronary
artery disease (CAD). In order to spare small structures
such as coronary arteries (CA), a highly precise contouring
is needed; however, heart motion represents an obstacle
for a correct delineation. To date, the entity of motion-
induced CA displacement and margins for internal risk
volume (IRV) are poorly described. Aim of this study was
to quantify CA displacement and then estimate IRV
through the use of ECG-gated CT.
Material and Methods