Transcript Radiographie standard normale DE LA HANCHE

THE NEUROLOGICAL COMPLICATIONS OF
THE RADIOTHERAPY: ASPECTS IN IMAGING
F.AKID, Y.GUERMAZI, W.TURKI, I.AMMAR, S.CHAABOUNI, A.MAALEJ,
S.HADDAR, KH. BEN MAHFOUDH, J MNIF
Radiology department, Habib Bourguiba,Sfax, Tunisia
NEURORADIOLOGY : NR 23
Introduction:
 Neurological complications of radiotherapy are serious and
irreversible
 They are sources of major handicap
 The clinical context and imaging, mainly MRI,
cornerstone of diagnosis of these complications
are the
 The purpose of this work is to illustrate some aspects in
imaging of the neurological
radiotherapy
complications of
the
Materials and methods:
 Retrospective Study concerning 8 patients treated
by radiotherapy for diverse causes in particular for
an ENT cancer
 The average age varied between 14 and 41 years
 All our patients were treated by radiotherapy
 They underwent a brain MRI (n=7) and a
medullary MRI (n=1).
Materials and methods:
The motive was:
A
post therapeutic monitoring of a posterior fossa
medulloblastoma (n=1 )
 Routine supervision of a UCNT ( n=3 )
 Right hemiparesis and aphasia following treatment of a
cushing’s disease ( n=1 )
 Left
hemiplegia following radiotherapy for fibrillary
astrocytoma ( n=1 )
 Bilateral hearing loss after radiotherapy for nasopharyngeal
cancer ( n=1 )
 Behavior disorders with aphasia in a nasopharynx cancer (
n=1 )
Results:
The MRI showed :
 A radio-induced cavernoma in 3 cases
 Acerebral radionecrosis in 4 cases
 A medullary radionecrosis in one case
Results:
17%
36%
Radio-induced cavernoma
Cerebral radionecrosis
47%
Medullary radionecrosis
Case 1:
a
b
c
d
Axial T1 (a), T2 (b), gadolinium enhanced T1 (c) and ADC map (d) MR
images obtained, 2 years after radiation therapy for nasopharyngeal
carcinoma, in a 65 year old man with behavior disorders and aphasia.
Oval lesion in T1 hypointensity and T2 hyperintensity in the left temporal
lobe .
Gadolinium-enhanced T1 image (c) shows an irregular ring-enhancing
lesion with mass effect and edema . “Cerebral radionecrosis”
Case 2:
a
b
c
d
MR images obtained in a 47-year-old woman with left hemiplegia following
radiotherapy for glioblastoma
(a) Axial T1-weighted, (b) axial T2 and (c) FLAIR showing a right frontotemporal lesion associated to a vasogenic edema with mass effect
(d)Gadolinium-enhanced T1WI image shows a ring-enhancing lesion
Case 2:
e
f
g
(e) DWI image obtained at the same patient, shows a marked
hypointensity, which is typical for radiation necrosis.
(f) ADC map, which corresponds to (e), shows a markedly
high ADC value.
(g) Spectroscopy shows a peak of lipid (arrow)
Case 3:
d
a
b
c
Sagittal T1 (a), T2 (b), gadolinium enhanced T1 (c) and axial gadolinium
enhanced T1 (d) MR images obtained, 3 years after radiation therapy for
nasopharyngeal carcinoma, in a 46 year old man with hemiparesis.
Cervical medullary lesion in T1 hypointensity (a) and T2 hyperintensity
(b) extent of bulbo medullary junction to the lower edge of C7.
Gadolinium-enhanced T1WI image shows an irregular ring-enhancing
lesion. “medullary radionecrosis”
Case 4:
a
b
c
MR images obtained, 7 years after radiation therapy for
nasopharyngeal carcinoma, in a 52 year old man (supervision)
Axial FLAIR (a), axial T2*(b) and gadolinium enhanced T1 (c)
MR images showing a small nodular lesion in the left frontal
lobe with an heterogeneous low signal on T2* and unenhanced
after injection of gadolinium. “Radio-induced cavernoma”
Discussion:
 Radiation
therapy is considered effective in
nasopharyngeal carcinoma (NPC) and other head and
neck malignancies. However, it is not without
morbidity, and complications can develop as a result of
damage to neighboring structures.
 Many of the deleterious effects of radiation on the CNS
are well known. These include early effects that can
occur within a few weeks of the radiation therapy, such
as vasogenic edema due to increased capillary
permeability and vasodilation.
Discussion:
 Delayed effects can occur months to years after the
irradiation. These include cerebral atrophy, white
matter
necrosis, demyelination, gliosis, and
induction of neoplasm.
 Delayed radiation injury can also manifest as
vasculopathy with hyalinization and fibrinoid
necrosis of vascular walls, resulting in occlusion
and infarction as well as vascular proliferative
lesions such as capillary telangiectasia and
cavernoma .
Discussion:
 Delayed radiation effects are directly proportional
to dose and inversely related to fractional number
 The
mean interval between irradiation and
presentation is approximately 1 year for patients
who receive a total dose of 50 Gy; however, cases of
radiation necrosis have been reported as early as 3
months and as late as 19 years after radiation
therapy
Discussion:
 The typical MRI findings of radiation necrosis are
areas of cystic or fingerlike lesions of increased
signal intensity in white matter on T2WI images,
which frequently extend beyond the radiation
portals.
 Recent studies using DWI have shown that the
apparent diffusion coefficient (ADC) ratios in the
contrast-enhancing lesion are lower in recurrent
tumor than in radiation-induced injury.
Discussion:
 Nodular or rim enhancement may be seen,
because diffuse damage to the blood-brain barrier
is present, although the degree of enhancement
can vary with time.
 Larger
lesions may appear as islands of
enhancement surrounded by areas nonenhancing
necrosis.
Discussion:
 Minimal local mass effect for the size of the lesion
is typical.
 However, reactive vasogenic edema, which
often
accompanies this condition, can be extensive and
can produce substantial regional mass effect on
adjacent structures.
 These findings are often nonspecific and may not
permit differentiation from tumor recurrence.
Discussion:
 Most radio-induced cavernomas have a distinctive
appearance of their nidus with little or no
surrounding edema
 MR imaging usually shows a reticulated core of
heterogeneous signal intensity with a dark
peripheral rim of hemosiderin, giving a typical
“popcorn” appearance in T2*-weighted gradientecho (T2*GE)
Discussion:
 Specific spectroscopic changes that occur in
radiation necrosis have been reported and include
slight depression of NAA and variable changes in
Cho and Cr.
 In addition, radiation necrosis may show a broad
peak between 0 and 2 ppm, probably reflecting
cellular debris containing fatty acids, lactate (Lac),
and amino acids.
Discussion:
 MR spectroscopy and diffusion-weighted imaging
(DWI), are not the only method used to differentiate
radiation injury from recurrent tumor.
 Other methods that recently have been used for this
purpose such as positron-emission tomography (PET),
MR perfusion and CT perfusion.
 These techniques seem to be very promising
Conclusion:
 Late neurological complications of radiotherapy
are rare but serious
 The MRI and the functional neuro-imaging are the
highlight of the diagnostic
 The treatment remains primarily preventive