Upload
trannhi
View
220
Download
0
Embed Size (px)
Citation preview
Kenway Louie, HMS IIIGillian Lieberman, MD
Intracranial Tumors: A Radiologic Approach
Kenway Louie, HMS IIIGillian Lieberman, MD
November 2002
2
Kenway Louie, HMS IIIGillian Lieberman, MD
Our patient R.R.
• 46 y/o woman, with no signficant PMHx, discovered unconscious at home
• 6 mo history of headache, worse at night and early morning
• ? Hx decreasing visual acuity (4-8 mo)
• 1 wk history of nausea/vomiting
3
Kenway Louie, HMS IIIGillian Lieberman, MD
Radiologic anatomy of the brain
http://freud.tau.ac.il/~shakhar/neuro/movies.html http://www.med.harvard.edu/AANLIB/cases/caseM/mr3_t/031.html
4
Kenway Louie, HMS IIIGillian Lieberman, MD
Classification of brain tumors: a framework
** benign vs. malignant distinction less clinically relevant for intracranial tumors(mass effect, infiltration preventing removal, critical location)
brain neoplasm
primary metastatic
extra-axial intra-axial
neuronal glial
meningiomaastrocytomaglioblastomaependymoma
lung (50 %)breast (15%)melanoma (10%)
5
Kenway Louie, HMS IIIGillian Lieberman, MD
Classification of brain tumors: tissue of origin
CATEGORY EXAMPLE
• Tumors of neuroepithelial tissue astrocytoma, glioblastoma, ependymomas• Tumors of peripheral nerves Schwannoma, neurofibroma
• Tumors of meninges meningioma• Lymphomas and hemopoietic neoplasms primary lymphoma of CNS• Germ cell tumors germinoma
• Tumors of sellar region craniopharyngioma, pituitary adenoma
WHO Classification of Tumors of the Central Nervous System (2000)
• Broad categories of tumor nomenclature by tissue of origin• Implied grading scale based on histopathology (I-IV)
6
Kenway Louie, HMS IIIGillian Lieberman, MD
Incidence of brain tumors
http://uptodateonline.com
7
Kenway Louie, HMS IIIGillian Lieberman, MD
Astrocytomas and glioblastomas
• Gliomas comprise the majority of primary CNS tumors
• Histopathological grading: +/- nuclear atypia, mitosis, microvascular proliferation, necrosis
• Astrocytic tumors:- astrocytoma
- anaplastic astrocytoma
- glioblastoma multiforme
• Pathological grading defines treatment and prognosis
astrocytoma
anaplastic astrocytoma
glioblastoma multiformemalignant astrocytomas
DeAngelis LM. Brain tumors. New Engl J Med 2001; 344: 114-23.
8
Kenway Louie, HMS IIIGillian Lieberman, MD
Role of imaging in neurooncology
• Diagnosis- Ddx: tumor vs. infection vs. vascular- Clinical complications: parenchyma compromise, mass effects
• Treatment- Treatment planning- Localization for therapeutic modalities: EBRT, stereotaxic surgery- Evaluation
• Post-treatment surveillance- Tumor recurrence
9
Kenway Louie, HMS IIIGillian Lieberman, MD
Menu of tests for suspected brain tumor
• CT +/- contrast- Quick scan time appropriate for emergent imaging- Low soft tissue delineation limits diagnostic capability- Beam-hardening artifact : can miss structural lesions, esp in
posterior fossa
• MR +/- gadolinium- Procedure of choice for imaging brain tumors- Sensitive for edema- Sensitive for small tumors near bone- Gadolinium-DPTA enhances regions of blood-brain barrier
disruption (T1), increases sensitivity of neoplasm detection
10
Kenway Louie, HMS IIIGillian Lieberman, MD
A brief primer on signal intensity in MRI
XR/CT T1 T2Dense bone bright dark darkAir dark dark darkFat dark gr bright brightWater light gr dark brightBrain light gr ‘anatomic’ int.
XR/CT T1 T2 enhancementInfarct dark dark bright subacuteBleed bright bright bright noTumor dark dark bright yesMS plaque dark dark bright acute
11
Kenway Louie, HMS IIIGillian Lieberman, MD
Differential diagnosis of intracranial masses
• Primary brain tumor• Metastatic brain tumor• Vascular disease
- Aneurysms, AV malformations- Cerebral hemorrhage- Cerebral infarct
• Infection- Abscess- Granulomatous disease- AIDS and associated conditions
• Inflammatory disease• Cyst
Locationintra- vs extra-axial?supra- vs infra-tentorial?WM vs GM?
MultiplicityHeterogeneityEnhancement
12
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
http://www.med.harvard.edu/AANLIB/cases/caseM/mr3/032.html
13
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
DeAngelis LM. Brain tumors. New Engl J Med 2001; 344: 114-23.
-- Irregular, dense contrast enhancement-- Ring enhancement common, irregular and
-nodular, often around necrosis-- Infiltrative, can involve WM and cross midline
14
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
- Base of skull (parasellar), cerebral convexities- Adjacent to bone, ‘dural tail’- Characteristic diffuse pattern of enhancement- Slow growing, little edema, histologically benign
DeAngelis LM. Brain tumors. New Engl J Med 2001; 344: 114-23.
15
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
- Tends to occur at gray-white junction- Multifocality in > 50%- Smooth ring-like enhancing rim, necrotic center - Large amounts of vasogenic edema
Gilman S. Imaging the brain. Second of two parts. New Engl J Med 1998; 338: 889-96.
16
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
- Clinically more acute Hx with fever- Ring enhancing lesion, thin rim with uniform
-enhancement- Accompanying mass effect and edema- Can appear similar to necrotic tumors
http://www.xraydoor.com/image/shenjing/pic/nnz5.jpg
17
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
- DWI/PWI T2 imaging in the acute stroke setting- T1 contrast enhancement over days s/p infarct,
-does not acutely enhance- Irregular serpiginous enhancement following
-cortical surface of lobar infarcts- Enhancing abnormality will resolve (6-8 wks)
http://www.med.harvard.edu/AANLIB/cases/case20/mr3/015.html
18
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
-- Multiple lesions in periventricular white matter-- Hypointense on T1, hyperintense on T2-- T2 images extremely sensitive for MS plaques
http://www.med.harvard.edu/AANLIB/cases/case5/mr11/036.html
19
Kenway Louie, HMS IIIGillian Lieberman, MD
MR characteristics of intracranial masses
• Normal structures• Glioma• Meningioma• Metastases• Abscess• Infarction• White matter disease• Tumor recurrence
- Hyperenhances for several months s/p resection -surgery (hypervascularity, lack of BBB)
- After ~6 mo, hypovascular gliosis should be -hyperintense on T2 and nonenhancing on T1
20
Kenway Louie, HMS IIIGillian Lieberman, MD
Our patient R.R.: CT
CT CT +I
Midline R->L shiftHypodense R occipital/temporal mass and edema
Images courtesy of Chad Brecher, MD
BIDMC BIDMC
21
Kenway Louie, HMS IIIGillian Lieberman, MD
T2
Our patient R.R.: MR +/- gadolinium
T1 post
Contrast enhancing lesionExtensive surrounding edema
Crosses midline at splenium (cc)
Images courtesy of Chad Brecher, MD
BIDMC BIDMC
22
Kenway Louie, HMS IIIGillian Lieberman, MD
Our patient R.R.: diagnosis?• Clinical hx (HA, N/V) c/w raised ICP
• CT: hypodense mass and evidence of significant edema
• MR: large diffuse R temporal lobe mass with extensive temporal, occipital, parietal lobe edema
• MR: multiple necrotic foci within mass
• MR: lesion appears to cross midline at splenium of corpus callosum
Malignant astrocytomaconfirmed on surgical biopsy as III/IV anaplastic astrocytoma
23
Kenway Louie, HMS IIIGillian Lieberman, MD
Role of imaging in neurooncology
• Diagnosis- Ddx: tumor vs. infection vs. vascular- Clinical complications: parenchyma compromise, mass effects
• Treatment- Treatment planning- Localization for therapeutic modalities: EBRT, stereotaxic surgery- Evaluation
• Post-treatment surveillance- Tumor recurrence
24
Kenway Louie, HMS IIIGillian Lieberman, MD
Evaluation of brain herniation
Types of brain herniation
1) Cingulate
2) Central transtentorial
3) Uncal transtentorial
4) Upward cerebellar
5) Cerebellar tonsillar
6) Transcalvarial
Kaye AH and Laws ER (eds), 2001.
25
Kenway Louie, HMS IIIGillian Lieberman, MD
Uncal herniation
http://medlib.med.utah.edu/WebPath/CNSHTML/CNS057.html
• Medial and downward displacement of basal uncal edge and hippocampal gyrus into posterior fossa
• Occurs most often with temporal lobe or middle fossa tumors
• Midbrain effects: contralateral cerebral peduncle, ipsilateral CN III
BIDMC
BIDMC
Images courtesy of Chad Brecher, MD
26
Kenway Louie, HMS IIIGillian Lieberman, MD
Our patient R.R.: clinical findings
Ventricular compression Uncal herniation
Images courtesy of Chad Brecher, MDBIDMC BIDMC
27
Kenway Louie, HMS IIIGillian Lieberman, MD
Role of imaging in neurooncology
• Diagnosis- Ddx: tumor vs. infection vs. vascular- Clinical complications: parenchyma compromise, mass effects
• Treatment- Treatment planning- Localization for therapeutic modalities: EBRT, stereotactic surgery- Evaluation
• Post-treatment surveillance- Tumor recurrence
28
Kenway Louie, HMS IIIGillian Lieberman, MD
Additional diagnostic neuroimaging
• MR spectroscopy• SPECT• PET• Echo planar MR (fMRI)
29
Kenway Louie, HMS IIIGillian Lieberman, MD
MR spectroscopy
• USE:
- Detection of tumor infiltration outside border of MR contrast enhancement
- Histopathological grading
• Nuclear magnetic resonance (NMR) spectroscopic analysis of chemical composition in designated area of interest
• Only select compounds detected by H1-MRS, importantly:
- N-acetylaspartate (NAA)
Byproduct of neurotransmitter glutamate, signals neuronal presence
Decreased in gliomas
- Choline
Component of cell membranes
Increased in tumors, may be related to altered membrane turnover
• Pathological spectra: NAA/choline ratios < 1
30
Kenway Louie, HMS IIIGillian Lieberman, MD
MR spectroscopy
Woodruff WW. Fundamentals of neuroimaging. Philadelphia: W. B. Saunders 1993.
31
Kenway Louie, HMS IIIGillian Lieberman, MD
Single photon emission computed tomography (SPECT)
• USE:
- Preoperative diagnosis of nonmalignant vs. malignant brain lesions
- Histopathological grading
- Localizing areas of maximum uptake for biopsy
• Single photon scintigraphy using Thallium-201, a measure of perfusion and uptake
• Correlation between early and delayed tumor uptake and subsequent surgically-determined tumor grade
• Not as useful as FDG-PET in distinguishing between radiation necrosis and tumor recurrence
32
Kenway Louie, HMS IIIGillian Lieberman, MD
Single photon emission computed tomography (SPECT)
T2 SPECT-TI
http://www.med.harvard.edu/AANLIB/
• 51 y/o woman L parietal anaplastic astrocytoma• High thallium uptake indicative of tumor recurrence• Lg region of mixed signal on T2, only subset corresponds to tumor
33
Kenway Louie, HMS IIIGillian Lieberman, MD
Positron emission tomography (PET)
http://www.med.harvard.edu/AANLIB/cases/caseSLU2/mr1-dg2/012.html
• 53 y/o man R parietal-occipital grade IV astrocytoma• s/p focused external beam radiation therapy• FDG-PET shows increased glucose metabolism 3 mos later, indicating
tumor recurrence rather than radiation necrosis
T = 0 T = 3 mos
34
Kenway Louie, HMS IIIGillian Lieberman, MD
Our patient R.R.: clinical course• 5/00 - Initial presentation
- Diagnosed with anaplastic oligoastrocytoma grade III/IV- Underwent surgical debulking -> partial resection
• 6/00 - Post-surgical followup- Began involved-field external beam radiation therapy
• 8/00 - Preevaluatiion for chemotherapy- Favorable response to irradiation, mass effect resolved- Scheduled to start multiple cycle PCV
• 6/01 - Recurrent tumors and increasing headaches- Surgical redebulking of tumor
• 1/02 - Post-chemotherapy followup- Clinically stable, but enlargement of tumor into surgical cavity- MR spectroscopy: increase choline:NAA ratio- New chemotherapy regimen started: CPT-11
• 10/02 - Stable followup
35
Kenway Louie, HMS IIIGillian Lieberman, MD
5.23.00 s/p craniotomy and partial surgical resection
BIDMC
36
Kenway Louie, HMS IIIGillian Lieberman, MD
8.7.00 3 mos s/p partial resection, focused EBRT
BIDMC BIDMC
37
Kenway Louie, HMS IIIGillian Lieberman, MD
6/11/01 s/p surgical redebulking
BIDMC
38
Kenway Louie, HMS IIIGillian Lieberman, MD
1.7.02 clinically stable, radiologic evidence of tumor recurrence
BIDMC BIDMC
39
Kenway Louie, HMS IIIGillian Lieberman, MD
10.11.02 clinically stable, radiologic evidence of tumor recurrence
BIDMC
40
Kenway Louie, HMS IIIGillian Lieberman, MD
Summary
• Initial neurologic imaging exam guided by history and clinical suspicion
• CT applicable if concern for intracranial bleed
• MRI is the diagnostic modality of choice for the evaluation of suspected intracranial neoplasms
• Additional functional imaging (MR spectroscopy, Th201-SPECT, and FDG-PET) may improve diagnostic capability, currently not used for initial diagnosis
Leeds NE and Taveras JM. 1969.
41
Kenway Louie, HMS IIIGillian Lieberman, MD
References
• Atlas SW. Adult supratentorial tumors. Semin Roentgenol 1990; 25: 130-54.• DeAngelis LM. Brain tumors. New Engl J Med 2001; 344: 114-23.• Gilman S. Imaging the brain. First of two parts. New Engl J Med 1998; 338: 812-20.• Gilman S. Imaging the brain. Second of two parts. New Engl J Med 1998; 338: 889-96.• Hesselink JR and Press GA. MR contrast enhancement of intracranial lesions with Gd-DTPA.
Radiol Clin North Am 1988; 26: 873-87.• Johnson KA and Becker JA. The Whole Brain Atlas. http://www.med.harvard.edu/AANLIB/• Kaye AH and Laws ER (eds). Brain tumors: an encyclopedic approach (2nd ed). New York:
Churchill Livingstone 2001.• Leeds NE and Taveras JM. Dynamic factors in diagnosis of supratentorial brain tumors by
cerebral angiography. Philadelphia: W. B. Saunders 1969.• Lindsay KW, Bone I, and Callander R. Neurology and neurosurgery illustrated. Philadelphia:
Churchill Livingstone 1997.• Reeder MM. Reeder and Felson’s gamuts in radiology: comprehensive lists of roentgen
differential diagnoses (3rd ed). New York (Springer-Verlag) 1993.• UpToDate. http://uptodateonline.com• Woodruff WW. Fundamentals of neuroimaging. Philadelphia: W. B. Saunders 1993.
42
Kenway Louie, HMS IIIGillian Lieberman, MD
Acknowledgements
• Chad Brecher, MD• Larry Barbaras and Cara Lyn D’amour, our Webmasters• Pamela Lepkowski• Gillian Lieberman, MD