ESTRO 36 Abstract Book

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S611 ESTRO 36 2017
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Conclusion
Our study shows that SRT and WBRT-SIB offer a good LC
and OS, without significant differences. Probably these
data maybe due to the baseline patients selection and size
simple therefore we are analyzing QoL and neurocognitive
function of survivor patients to understand the global
impact of these two modalities of treatments.
EP-1129 Fractionated stereotactic radiotherapy for the
treatment of cavernous sinus meningiomas
I. Tovar Martin1, P. Vargas1, M. Zurita1, R. Guerrero1, E.
Saura1, J.L. Osorio2, A. Horcajadas3, J. Busquier4, C.
Prieto 1, S. Rodríguez1, A. Ruiz1, R. Ching1, J. Expósito1, R.
Del Moral1
1 Virgen de las Nieves University Hospital, Radiation
Oncology, Granada, Spain
2 Virgen de las Nieves University Hospital, Physics,
Granada, Spain
3 Virgen de las Nieves University Hospital, Neurosurgery,
Granada, Spain
4 Virgen de las Nieves University Hospital,
Neuroradiology, Granada, Spain
Purpose or Objective
The aim of this retrospective study is to report the results
obtained with this technique at our institution in terms of
local control, toxicity and clinical situation at the end of
the study
Material and Methods
From April 2005 to December 2014, 54 patients with
cavernous sinus meningiomas have been treated. 53,5% of
meningiomas were located in the right cavernous sinus,
41,9% in the left cavernous sinus, and 4,7% were bilateral.
The median age was 60 years (interquartile range (IQR):
50-66), 76,7% women and 23,3% men. 23,3% of patients
were operated before the treatment. The mean dose of
radiation was 50 Gy in 25 fractions of 2 Gy per day, given
five days per week over 5 weeks. Most cases were treated
using a LINAC accelerator with 1 isocenter (97,6%) and 8
arcs of treatment (32,6%).
Results
The mean of follow-up was 29 months (range: 3-92). At
the end of the study 69,8% of the patients presented
disease stabilization and 23,3% decrease of the tumor size.
Only 2,3% of the patients had disease progression. Related
to clinical situation, 60,5% of the patients related the
same symptom as before the treatment, 9,3% had no
symptom and 18,6% had improvement of their quality of
live. Only 4,7% of the patients had worsening of their
symptoms. No acute toxicity was reported in 65,1% of the
patients. The most frequent one was headache and mainly
grade 1. In the 79,1% not late toxicity was reported, the
remainder presented toxicity grade 1-2 that was easily
controlled by medication.
Conclusion
Fractionated Stereotactic Radiotherapy is a modality of
treatment good tolerated and with excellent local control
for this kind of meningiomas that have traditionally posed
a major challenge for neurosurgeons and neuro-
oncologists.
EP-1130 Hippocampus Dosimetry in patients treated
with Stereotactic Radiosurgery for Brain Metastases
N.S. Iqbal1, J.R. Powell1, D.W.O. Tilsley1, A. Bryant2, A.E.
Millin2, D. Lewis2, J.N. Staffurth 1
1Velindre Cancer Centre, Department of Clinical
Oncology, Cardiff, United Kingdom
2Velindre Cancer Centre, Department of Physics, Cardiff,
United Kingdom
Purpose or Objective
Brain metastases occur in 20-40% of patients with cancer
and common primary sites include lung, breast, kidney and
melanoma. Traditionally, whole brain radiotherapy
(WBRT) has been the mainstay of treatment. Stereotactic
radiosurgery (SRS) has demonstrated improved survival,
better quality of life and neurocognitive function (NCF) for
patients with 1-3 brain metastases and high functionality.
Despite the precision of SRS, a significant proportion of
patient experience decline in NCF after the treatment:
63.5% of patients undergoing SRS alone had neurocognitive
decline at 3 months (Brown et al., 2016). The
hippocampus (HC) has been implicated in NCF impairment
following radiation as well as other disease processes such
as dementia. The tolerance dose of the HC is unclear for
single fraction SRS treatment. In a study of fractionated
radiotherapy, a dose of more than 7.3 Gy delivered to
>40% of the bilateral HC is associated with significantly
higher NCF impairment (Gondi et al., 2011). In animal
studies, doses as low as 2 Gy have shown evidence of
increased cell apoptosis in HC (Acharya et al., 2010).
Material and Methods
At Velindre Cancer Centre, Cardiff patients with 1-3 brain
metastases with WHO performance status 0-2 are treated
with SRS. A retrospective review of all patients treated
with SRS without WBRT was performed over 1 year
(January 2015 - Januay 2016). Patients were identified
using electronic database. We studied dose delivered to
hippocampi in our patient population. Bilateral
hippocampi were outlined manually according to RTOG
0933 atlas (Gondi et al., 2010) and dose volume histograms
were recreated using iPlan RT Dose 4.5, a BrainLab
software.
Results
30 patients were treated with SRS without WBRT in 1 year.
Mean age was 61. The most common primary site was lung
(12) followed by kidney (7) and melanoma (4). 19 patients
had a single metastasis. 70% (n.21) patients were alive for
more than 6 months after SRS; median survival was not
reached. Dmax (dose to 0.1cc of the HC) was >5Gy in 8
and 2-4.9 Gy in 12patients. 6 patients received >5 Gy and
8 patients received 2 - 4.9 Gy to 50% of the HC. A major
factor influencing high HC dose was the location of the
tumour. Metastases located in the temporal and medial
parietal lobes and cerebellum were associated with Dmax
>5Gy. Objective neurocognitive assessment was not
attempted in this study due to the challenges of collecting
such data retrospectively and the known confounding
factors including steroid and systemic anti-cancer therapy
use.
Conclusion
We have identified a considerable proportion of patients
receiving significant radiation dose to the HC. Overall
survival of patients is in line with previously published
studies. Prospective studies measuring NCF with SRS
treatment should also investigate doses to HC in order to
determine dose effect relationship and establish dose
tolerance for HC in SRS.
EP-1131 Evaluation of overall survival following SRS for
non-small cell lung cancer brain metastases
A. Keller1, S. All 1, H. Patel1, C. Sherrill1, B. Dumas1, M.
Mejia1, N. Ramakrishna2
1University of Central Florida, College of Medicine,
Orlando, USA