ESTRO 36 Abstract Book

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S750 ESTRO 36
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EP-1403 A comparison between 3D and volumetric
technique in lumbar vertebral palliative irradiation
N. Ricottone1, N. Cavalli2, E. Bonanno2, C. Marino2, G.
Pisasale 1, A. D'Agostino1 , A. Girlando1
1 HUMANITAS CCO, Radiation Oncology, Catania, Italy
2 HUMANITAS CCO, Medical Physics, Catania, Italy
Purpose or Objective
Lumbar rachis radiation treatment requires to take into
account dose to kidneys. Aim of this paper is to evaluate
if volumetric techniques can give an advantage when
irradiating young patients, patient with a long life
expectancy or patients with renal dysfunction. The clinical
advantage is to preserve renal function and to not
interfere with previous or further medical treatments that
make use of renal toxic drugs, as for instance: cisplatin,
carboplatin, ifosfamide.
Material and Methods
A comparison between four plans were performed: a two
fields three dimensional (3D) anterior-posterior plan (3D-
2F); a three fields (0°-150°-210°) 3D plan (3D-3F); a VMAT
plan and a second VMAT plan spine sparing (VMAT-SS).
Dose prescription was 30 Gy in 10 fractions. All plans were
calculated with Eclipse 13.6 using AAA algorithm. 3D plans
were calculated using MLC shielding and different
weighted fields; regarding VMAT plans dose constraints
according to QUANTEC were used.
Results
Even if dose delivered to kidneys do not exceed QUANTEC
dose constraints, VMAT plans achieve better results in
term of dose reduction to OARs particularly for kidneys (as
showed in the table 1) thus without affecting PTV
coverage (figure 1).
Figure1: DVH comparison between the two plans that gives
the best PTV coverage
Conclusion
Both 3D plans do not exceed kidneys QUANTEC reference
dose constraints. Doses under QUANTEC constraints can
cause renal dysfunction in long survivors, young patients
and oligometastatic patients. In these situations it is
important to consider VMAT planning that gives the
opportunity to reduce dose delivered to kidneys
decreasing the probability to develop a late renal
dysfunction and giving the opportunity for further toxic
renal drugs treatments.
EP-1404 Survival time following palliative whole brain
radiotherapy to treat brain metastases
A. Billfalk Kelly1, M. Dunne1, C. Faul1, O. McArdle 1, I.
Fraser1, J. Coffey1 , A. Boychak1, B.D. O'Neill1, D.
Fitzpatrick1
1 St. Lukes Radiation Oncology Network, Radiation
Oncology, Dublin 6, Ireland
Purpose or Objective
To evaluate the overall survival times of patients with
brain metastases who were treated in our institution with
WBRT, comparing patients over and under 70 years old,
and between fractionation schedules.
Material and Methods
A retrospective review was carried out of patients treated
with WBRT over a two year period (2013-2014). Data was
collected with regards to the time of initial histological
diagnosis, dose delivered, age, in-or outpatient basis,
extracranial disease status, and time to death, or last
known follow up.
Results
101 patients were identified for analysis. The median age
was 64 years (range 32-88).
The radiotherapy was delivered as two opposed 6MV-10MV
photon beams, with shielding to the lenses. 50.5% of
patients were prescribed 30Gy in 10 fractions, 33.7% 20Gy
in 5 fractions and 15.8% patients were prescribed other
fractionation schemes. 29.7% were treated as inpatients,
and 70.3% as outpatients. The 4 most common histological
subtypes were NSCLC 42.6%, small cell lung carcinomas
19.8%, breast adenocarcinoma 14.9%, and malignant
melanoma 12.9%. 17.8% of patients had a biopsy or
resection of the brain metastases. 11.9% of patients
received stereotactic radiotherapy and 2% had already
received prophylactic cranial irradiation.
The median follow-up was 2.5 months (range: 2 days–30.5
months) from the end of RT. Median overall survival was
2.6 months (95% CI: 1.1 to 4.0). Overall survival at 1 year
was 24%.
All of those aged >70 years died. Overall survival differed
significantly between those < 70 years of age and those >
70 (p< .0005). Median overall survival at 12 months was
5.5% for those <70 years and 1.0 months for those >70
years. The hazard (risk of death) is higher and thus the
prognosis worse, for older patients controlling for RT dose
and Brain surgery or biopsy (p= .011).
Univariate analysis revealed that higher RT doses were
significantly associated with longer survival (p< .0005),
although this may be due to patients with better
performance status receiving 30Gy in 10 fractions as
opposed to 20Gy in 5 fractions.
Conclusion
Our review shows that survival for most patients is poor in
patients who have brain metastases treated with WBRT,
which is consistent with international data. 6.9% of
patients did not complete the prescribed course of
radiotherapy due to clinical deterioration, therefore some
patients may be better served with shorter courses of
radiotherapy, or treatment with steroids alone, in order
to minimise their time in hospital and to ensure maximum
quality of life.